DESC:TECHNICAL FIELD

The present disclosure generally relates to a vehicle. Particularly but not exclusively present disclosure relates to a hydraulically operated actuation systems of the vehicle. Further, embodiments of the present disclosure disclose a booster assembly for the hydraulically operated actuation systems of the vehicle.

BACKGROUND OF THE DISCLOSURE

Generally, vehicles are provided with one or more hydraulically operated actuation systems include, but are not limited to, hydraulic brake system and hydraulic clutch system. Such hydraulically operated actuation systems generally comprise of a reservoir to store the hydraulic fluid and a pressurising unit to pressurise the hydraulic fluid for supplying to the actuation systems. In the hydraulically operated actuation system, hydraulic fluid is pressurised when an actuation pedal is operated by a user or a driver, and the pressurised hydraulic fluid is supplied to the actuation system for obtaining desired function.

One such hydraulically operated actuation system used in the vehicles is hydraulic braking system. Conventional hydraulic braking systems comprises of a brake pedal, a vacuum booster, a tandem master cylinder (TMC) and braking circuits. The vacuum booster intensifies the force applied by a driver to generate hydraulic pressure in the TMC in order to apply brakes. The TMC includes a fluid reservoir for providing fluid to the braking circuits. The braking circuits include front brake circuits and rear brake circuits.

In the hydraulic braking systems, pedal feel and response time of the braking application are important factors. The pedal feel depends on pedal travel, pedal effort and braking action generated due to brake application. The response time of the braking application is defined as time elapsed between initiation of brake pedal and moment of attending pressure of a specified value in the braking system. Total brake pedal travel is the summation of travel required for initiation of generation of pressure in TMC i.e. closing of the oil inlet ports by the TMC piston seal, travel consumed to close the gap between brake pad/lining and brake disc/drum and in elastic deflection of the brake system. In the conventional hydraulic braking systems, when a driver applies a brake i.e. on application of brake pedal, the TMC supplies fluid to brake systems. In more elaborate way, the TMC generates a hydraulic pressure once the TMC piston seal covers the oil inlet port of the TMC. For generation of pressurized fluid, TMC push rod has to travel some distance to close the TMC inlet ports which is known as dead travel of TMC. The pressurized fluid is required for the braking action during each brake application. Also, the pressurized fluid is required to overcome shoe return spring force and to move the brake shoe/pad for closing the gap between the brake pad/lining and brake disc/drum. However, there incurs a delay in generating the braking action. Pressure generation in the TMC depends on the pedal effort and movement of TMC piston. The delay in generating pressure fails to generate the required brake pressure, when pressure needs to be created spontaneously as and when the brake is applied. This may lead to accidents due to delay in application of the brake.

Similarly, hydraulically operated actuation system is used as hydraulic clutch actuation system in the vehicle. Conventional hydraulic clutch actuation systems comprises of a clutch pedal, a clutch master cylinder, clutch slave cylinder and a pull rod. The clutch master cylinder intensifies the force applied by a driver to generate hydraulic pressure and supplies the pressurised fluid to the slave cylinder for actuating the pull rod for disengaging the clutch. The master cylinder is fluidly connected to the fluid reservoir for providing fluid for clutch actuation. In the conventional hydraulic clutch actuation systems, when a driver presses the clutch pedal, the clutch master cylinder pressurises and supplies hydraulic fluid to the slave cylinder for clutch dis-engagement. However, the master cylinder receives hydraulic fluid during initial travel of the clutch pedal and pressurises the hydraulic fluid after the predetermined downward movement of the pedal. The pressurized fluid is required for the clutch dis-engagement during each clutch actuation. However, there incurs a delay in clutch dis-engagement. The delay in generating pressure fails to generate the required force for clutch dis-engagement, when pressure needs to be created spontaneously as and when quick dis-engagement of clutch is desired.

In light of the foregoing discussion, it is necessary to develop a booster assembly for hydraulically operated actuation system of the vehicle to overcome one or more limitations stated above.

SUMMARY OF THE DISCLOSURE

The one or more shortcomings of the prior art are overcome by an assembly as claimed and additional advantages are provided through the provision of assembly as claimed in the present disclosure.

Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

In one non-limiting embodiment of the present disclosure there is provided a booster assembly for a hydraulic braking system of a vehicle. The assembly comprising an inlet port fluidly connectable to a master cylinder of the hydraulic braking system, and an outlet port fluidly connectable to at least one of wheel cylinder and a calliper. A first solenoid valve fluidly connected to the inlet port, the first solenoid valve is configured to selectively route hydraulic fluid to the outlet port through a first and second flow passages. A second solenoid valve fluidly connected to the outlet port and the first and second flow passages, the second solenoid valve is configured to selectively route hydraulic fluid through the first and second flow passages based on brake pedal movement. The assembly further includes a pressure limiting valve provisioned in the first flow passage, wherein the pressure limiting valve is adapted to regulate the flow of the hydraulic fluid through the first flow passage. Further, an accumulator which fluidly connected to the pressure limiting valve and the second solenoid valve is provided in the assembly. The accumulator is configured to hold pressurised hydraulic fluid for supplying the pressurised hydraulic fluid to the outlet port for brake actuation.

In an embodiment of the disclosure the assembly comprises a pressure switch provided in the accumulator to determine the pressure of the hydraulic fluid in the accumulator. The pressure switch is interfaced with the first solenoid valve and the second solenoid valve and transmits a signal comprising pressure of the hydraulic fluid.

In an embodiment of the disclosure, the first solenoid valve routes the hydraulic fluid through the first passage if the pressure of the hydraulic fluid is more than a predetermined value. Further, the first solenoid valve routes the hydraulic fluid through the second passage if the pressure of the hydraulic fluid is less than a predetermined value.

In an embodiment of the disclosure, the second solenoid valve is interfaced with a position sensor provided in a brake pedal of the hydraulic braking system. The second solenoid valve routes the hydraulic fluid from the first flow passage to the outlet port during forward movement of the brake pedal. Further, the second solenoid valve routes the hydraulic fluid from the outlet port to the master cylinder through the second passage during return movement of the brake pedal.

In an embodiment of the disclosure the assembly comprises a damping unit fluidly connected to the first flow passage.

In an embodiment of the disclosure, the accumulator is fluidly connected to the second flow passage through a non-return valve.

In an embodiment of the disclosure, the pressure limiting valve allows the flow of the hydraulic fluid through the first passage if the pressure of the hydraulic fluid is more than the predetermined value.

In an embodiment of the disclosure, the accumulator supplies pressurised hydraulic fluid to the outlet port for brake application up-to predetermined distance of brake pedal movement during of forward movement of the brake pedal.

In another non-limiting embodiment of the disclosure there is provided a hydraulic braking system for a vehicle. The system comprises a brake pedal pivoted to firewall of the vehicle, wherein the brake pedal is configured to move between first position and second position for operating the braking system. A vacuum booster coupled to the brake pedal, and a master cylinder fluidly connected to a hydraulic fluid reservoir, wherein the master cylinder is linked to the vacuum booster to pressurise the hydraulic fluid. Further, the brake system comprises a booster assembly which is fluidly connected to the master cylinder and at least one of wheel cylinder and a calliper for supplying the pressurised hydraulic fluid for brake actuation up-to predetermined distance of brake pedal movement during of forward movement of the brake pedal.

In an embodiment of the disclosure the system comprises a position sensor provisioned on the brake pedal to detect the direction of movement of the brake pedal. The position sensor is interfaced with the booster assembly.

In yet another non-limiting embodiment of the disclosure there is provided a hydraulic clutch actuation system of a vehicle. The assembly comprises an inlet port fluidly connectable to a master cylinder of the hydraulic clutch actuation system, and an outlet port fluidly connectable to a slave cylinder. An accumulator configured to hold pressurised hydraulic fluid. Further, the booster assembly includes a direction control valve which is fluidly connected to the inlet port through a first flow passage, and to the accumulator through a second flow passage. The direction control valve is configured to selectively route hydraulic fluid to the outlet port through the first and second flow passages for clutch actuation based on clutch pedal movement.

In an embodiment of the disclosure, the direction control valve is interfaced with a position sensor is provided in a clutch pedal of the hydraulic clutch actuation system. The direction control valve is configured to route hydraulic fluid from the accumulator to the outlet port up-to predetermined distance of the clutch pedal movement during forward movement of the clutch pedal. Further, the direction control valve is configured to route hydraulic fluid from outlet port to the accumulator up-to predetermined distance of the clutch pedal movement during return movement of the clutch pedal.

In an embodiment of the disclosure, the accumulator is fluidly connected to the first flow passage through a non-return valve.

In still another non-limiting embodiment of the disclosure there is provided a hydraulic clutch actuation system for a vehicle. The system comprises a clutch pedal pivoted to firewall of the vehicle, wherein the clutch pedal is configured to be moved between the first position and the second position for engaging and disengaging a clutch. A master cylinder fluidly connected to a hydraulic fluid reservoir, and a booster assembly fluidly connected to the master cylinder and clutch slave cylinder for supplying the pressurised hydraulic fluid for clutch actuation.

In an embodiment of the disclosure the system comprises a position sensor provisioned on the clutch pedal to detect the direction of movement of the clutch pedal. The position sensor is interfaced with the booster assembly.

It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined together to form a further embodiment of the disclosure.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

OBJECTIVE OF THE DISCLOSURE

One non-limiting object of the present disclosure is related to a booster assembly for a hydraulic braking system of a vehicle which generates pressurized fluid in advance during each brake application for reducing the response time of braking application.

One non-limiting object of the present disclosure is related to a booster assembly for a hydraulic braking system of a vehicle which reduces the brake pedal travel consumed in closing the gap between brake pad /lining and brake disc/drum.

One non-limiting object of the present disclosure is related to a booster assembly for a hydraulic clutch actuation system of a vehicle which generates pressurized fluid in advance during each clutch actuation for reducing the response time of clutch dis-engagement.

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES

The novel features and characteristic of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:

FIGURE 1 illustrates an exemplary schematic representation of the hydraulic braking system with booster assembly in accordance with an embodiment of the present disclosure.

FIGURE 2 illustrates a position sensor fitted on a brake pedal of the hydraulic braking system according to some embodiment of the present disclosure.

FIGURE 3 illustrates schematic diagram of the exemplary booster assembly for hydraulic braking system of in accordance with an embodiment of the present disclosure.

FIGURE 4 illustrates electrical circuitry for operating the booster assembly in accordance with some embodiment of the present disclosure.

FIGURE 5 illustrates an exemplary schematic representation of the hydraulic clutch actuation system with booster assembly in accordance with an embodiment of the present disclosure.

FIGURE 6 illustrates position sensor fitted on a clutch pedal of the hydraulic clutch actuation system according to some embodiment of the present disclosure.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION

The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other mechanism for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the scope of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristic of the disclosure, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.

To overcome one or more drawbacks mentioned in the background, the present disclosure provides a booster assembly for hydraulic braking system. The booster assembly is fluidly connected with the Tandem Master Cylinder (TMC), and is interfaced with a position sensor on a brake pedal. The booster assembly stores pressurized fluid, in advance, for supplying to the braking system during each brake application and for next brake cycle as well. The position sensor is fitted on the brake pedal and is activated upon brake application. The booster assembly is incorporated at outlet port side of the TMC i.e. outlet port of the TMC is connected to the inlet port of the booster assembly. The booster assembly comprises a accumulator, a pressure limiting valve, a damping device, a first solenoid valve (an on/off solenoid valve), non-return valve, a pressure switch and a second solenoid valve. The inlet port of the booster assembly is divided into two paths, wherein one path also referred as first passage is connected to the inlet port of the first solenoid valve, and other path also referred as second passage is connected directly to braking system through the second solenoid valve. An outlet port of the first solenoid valve is connected to the pressure limiting valve. In one embodiment the pressure limiting valve is a spring loaded valve. The pressure limiting valve is connected to the accumulator through inlet port of the accumulator. The accumulator contains predetermined amount of pressurized fluid, pressurized under the compressed gas or the spring element. The accumulator is charged with pressure during each brake application, particularly, a part of pressure generated for braking is stored in the accumulator after brake release. The accumulator which is charged with the pressure during previous brake application is utilized for the pre charging of the brake system for next brake application. The accumulator is coupled to the pressure switch for activating the first and second solenoid valves. A delivery port of the accumulator is connected to the second solenoid valve. In an embodiment, the second solenoid valve is activated by the position sensor through the pressure switch. The second solenoid valve comprises a delivery port which is connected to the brake circuits, through which the pressurized fluid flows to the brake circuits.

During brake Application the position sensor fitted on the brake pedal is activated (if the accumulator has sufficient pressure stored in it to aid the braking action). The position sensor activates the second solenoid valve, which in turn connected accumulator for supplying the hydraulic fluid to the brake circuit. The brake fluid from the TMC flows into the pressure limiting valve through the first solenoid valve when the first solenoid valve is in deactivated state (because of sufficient pressure in the accumulator). The pressure limiting valve which may be spring loaded is compressed by the force exerted by the fluid flow. The pressure limiting valve allows the fluid to flow into the accumulator. The accumulator which already contains pressurized fluid is provided with extra pressure when the fluid is supplied from the pressure limiting valve into the accumulator. The pressurized fluid is supplied to the second solenoid valve through the delivery port of the accumulator. The second solenoid valve provides the pressurized fluid to the brake circuits for braking action. Further, during brake release, the second solenoid may be deactivated. In such deactivated condition, the outlet port of the TMC is connected directly to the brake circuits so that the fluid flows back to the TMC reservoir from brake circuit through the second solenoid valve and also fluid flows from the accumulator to the TMC reservoir through the pressure limiting valve and the first solenoid valve. The pressure limiting valve monitors and maintains the pressure in the accumulator when the fluid is flown back during the brake release. In this way, the accumulator is charged with pressure for next brake cycle.

The present disclosure also provides a booster assembly for a hydraulic clutch actuation system of the vehicle. The booster assembly consist of pressure accumulator and direction control valve. The accumulator is connected to the clutch slave cylinder (CSC) through direction control valve. Also the clutch master cylinder (CMC) is connected to the clutch slave cylinder (CSC) through direction control valve. The direction control valve is electronically actuated based on the signal from the position sensor fitted on the clutch. Normally, when clutch pedal is in released position the direction control valve in deactivated state. In this state the clutch master cylinder (CMC) is directly connected to clutch slave cylinder (CSC) and the accumulator is disconnected from the Clutch slave cylinder (CSC). The direction control valve is configured such that it allows only one connection to the clutch slave cylinder (CSC) at a time, either from clutch master cylinder or from the accumulator. Further, the position sensor is configured such that it acts as a rotary switch and gives the signal to direction control valve after pedal actuation in forward direction as well as during return stroke also.

The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that an assembly, device or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such assembly or system or method. In other words, one or more elements in an assembly or system proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus.

In the following description the words such as forward, return are referred with respect to particular orientation of the system as illustrated in drawings of the present disclosure. The words are used to explain the aspects of the present disclosure and for better understanding. However, one should not construe such terms as limitation to the present disclosure, since the terms may interchange based on the orientation of the system.

Henceforth, the present disclosure is explained with the help of figures of hydraulic braking system and hydraulic clutch actuation system of a vehicle. However, such exemplary embodiments should not be construed as limitations of the present disclosure. A person skilled in the art can envisage various such embodiments without deviating from scope of the present disclosure. Further, it is to be noted that the hydraulic braking system and hydraulic clutch actuation system can be in the vehicles. However for the purpose of simplicity the vehicle is not illustrated in the figures of the present disclosure.

Referring now to figures in which FIGURE1 is an exemplary embodiment of the present disclosure which illustrates a hydraulic braking system (100) for a vehicle. The hydraulic braking assembly (100) comprises a support bracket (not shown) mounted on firewall of the vehicle for supporting the brake pedal (102). The support bracket comprises a mounting face and side arms extending from opposing edges of the mounting face. The brake pedal (102) having an upper end and lower end is pivotally mounted on the support bracket at pivot point through its upper end using a hinge pin, a pedal pad is mounted to a lower end of the brake pedal (102) for actuating the brake pedal (102) by the driver/user. The brake pedal (102) is coupled to vacuum booster (103) which is adapted to intensify the force applied by the driver or user on the brake pedal (102) for brake application. The vacuum booster (103) is linked to a tandem master cylinder (104) for pressurising hydraulic fluid for braking application. The tandem master cylinder (104) is fluidly connected to a hydraulic fluid reservoir (105) for receiving the hydraulic fluid for brake application. When the brake pedal (102) is pressed by the driver or user the vacuum booster (103) moves the piston in the tandem master cylinder (103) which draws the hydraulic fluid from the hydraulic reservoir (105) up to predetermined travel of the brake pedal (102), and then starts pressurising the hydraulic fluid. Outlet of the tandem master cylinder (103) is fluidly connected to a booster assembly (300) which stores the pressurised hydraulic fluid, and supplies to braking system for brake applications. The booster assembly (300) is also fluidly connected to at least one of wheel cylinder and a calliper for supplying the pressurised hydraulic fluid for brake actuation up-to predetermined distance of brake pedal (102) movement during of forward movement of the brake pedal (102). In an embodiment of the disclosure, the booster assembly (100) may also be called as boost module.

The hydraulic braking system (100) also comprises a position sensor (101) provisioned on the brake pedal (102). The position sensor (101) is adapted to detect direction of movement of the brake pedal (102) i.e. pedal travel. The position sensor (101) detects pedal position during initial forward travel of the brake pedal (102) during brake application, and initial return travel of brake pedal (102) during brake release. The booster assembly (300) is configured at an outlet side of the tandem master cylinder (104) i.e. the booster assembly (300) is fluidly connected to the outlet port of the tandem master cylinder (104) to receive fluid from the tandem master cylinder (104) through the outlet port. The booster assembly (300) is also fluidly connected to the brake circuits for providing pressurized fluid to the braking circuits during each brake application.

FIGURE 2 illustrates side view of the brake pedal (102) with the position sensor (101) fitted on the brake pedal (102) in accordance with an embodiment of the present disclosure. The position sensor (101) is a separate attachment (detachable) which is fitted on the brake pedal (102) of hydraulic braking system (100), at a hinge point. The position sensor (101) is provisioned to activate/deactivate one or more control valves provided in the booster assembly (300) for allowing fluid flow for boosting the pressurized fluid into the brake circuits. The one or more control valves of the booster assembly (300) receives electric signal from the position sensor (101) during initial forward travel of brake pedal (102) application and initial return travel of brake pedal (102) during brake release. The position sensor (101) detects the direction of pedal travel and is activated during initial amount of pedal travel irrespective of direction of travel. In an embodiment, the position sensor (101) is mounted on a circular cover cap front arm (204) on the brake pedal boss (206), with two protruding arms i.e. cover cap rear arm (202) and cover cap front arm (203). The position sensor (101) is placed such that one arm is behind the brake pedal (102) and another is after brake pedal (102).

FIGURE 3 is an exemplary embodiment of the disclosure which illustrates a detailed view of the booster assembly (300) for hydraulic braking system (100). The booster assembly (300) comprises an inlet port (301) fluidly connected to an outlet of the tandem master cylinder (104), and an outlet port (302) fluidly connected to braking circuit of the vehicle. Further, a first solenoid valve (303) is provided in the booster assembly (300), and is fluidly connected to the inlet port (301). The first solenoid valve (303) is configured to selectively route hydraulic fluid to the outlet port (302) through first and second flow passages (304 and 305). A second solenoid valve (306) is fluidly connected to the outlet port (302) and the first and second flow passages (304 and 305). The second solenoid valve (306) is interfaced with the position sensor (101), and is configured to selectively route hydraulic fluid through the first and second flow passages (304 and 305) based on brake pedal movement (301). In embodiment of the disclosure, the first and second solenoid valves (303 and 306) are powered by a battery (312) [shown in FIGURE. 4].

The booster assembly (300) also comprises a pressure limiting valve (307) provisioned in the first flow passage (304). The pressure limiting valve (307) comprises an inlet port and a delivery port. The inlet port of the pressure limiting valve (307) is connected to the delivery port of the first solenoid valve (303). Particularly, the inlet port of the pressure limiting valve (303) is connected to the inlet port of the booster assembly (300) through the first solenoid valve (303). In an embodiment of the disclosure, the pressure limiting valve (307) may be a spring loaded valve, and requires predetermined amount of force (F) to operate, for example to open the valve. The predetermined amount of force is provided by the fluid pressure flowing from the TMC (104) through the first solenoid valve (303) during brake application. The delivery port of the pressure limiting valve (307) is connected to an accumulator (308). During brake release, the pressure limiting valve (2) maintains a predefined pressure in the accumulator (308). In an embodiment of the disclosure, the accumulator (308) is a tank with compressible gas and rubber diaphragm which contains pressurized fluid and comprises an inlet port and a delivery port. In alternative embodiment, the accumulator (308) comprises a piston with the spring. The inlet port of the accumulator (308) is connected to the delivery port of the pressure limiting valve (307) and the delivery port is connected to the second solenoid valve (306) through a first flow passage (304). The accumulator (308) is charged with pressure during each brake application, particularly, a part of pressure generated for braking is stored in the accumulator (308) after each brake release. The accumulator (308) which is charged with the pressure during previous brake application is utilized for the pre charging of the brake circuit for next brake application. The accumulator (308) is coupled to a pressure switch (309) which is configured to measure the pressure of the hydraulic fluid in the accumulator (308). The pressure switch (309) is interfaced with the first solenoid valve (303) and the second solenoid valve (306). The pressure switch (309) controls the opening and closing of the first solenoid valve (303) and the second solenoid valve (306) (through the position sensor (101)). The pressure switch (309) is activated when the pressure in the accumulator (308) is more than a predetermined pressure value. In an embodiment of the disclosure, the predetermined pressure value is 3 bars. In such case, the first solenoid valve (303) will be in de-active state, and connects the TMC (104) to the pressure limiting valve (307). Also, the activated pressure switch (309) allows the actuation of the second solenoid valve (306) through the positions switch (101) when the brake pedal (102) is applied. The pressure switch (309) is deactivated when the pressure in the accumulator (308) is less than the predetermined pressure value. In an embodiment of the present disclosure, the predetermined value of pressure is three bar. In deactivated state of the pressure switch (309), the second solenoid valve (306) is also deactivated even on application of brake pedal (102). This ensures normal functioning of the hydraulic braking system (100) even if the pressure in the accumulator (308) is not charged in previous brake cycle and thus the hydraulic braking system (100) work as the existing brake system in case of failure of the booster assembly (300). The line with non-return valve (311) is connected to the accumulator (308) from the second flow passage (305) of the booster assembly (300) for supplying the pressurised fluid to the accumulator (308) if the pressure in the accumulator (308) is less than predetermined value.

The second solenoid valve (306) comprises two inlet ports and a delivery port, in which one of the inlet ports is connected to the delivery port of the accumulator (308) through first flow passage (304), and the other inlet port is connected delivery port of the TMC (104) directly through second flow passage (305). The delivery port of the second solenoid valve (306) is connected to the outlet port (302) of the booster assembly (300) which is in turn connected to the brake circuits. The second solenoid valve (306) receives control signals from the position sensor (101) for allowing fluid flow from the accumulator (308) to the brake circuits upon brake (102) application. The second solenoid valve (306) receives the control signals from the position sensor (101) during initial forward travel brake pedal (102) application and initial return travel of brake pedal (102) during brake release. In an embodiment, the second solenoid valve (306) is activated by the position sensor (101) through the pressure switch (309). During brake release, the second solenoid valve (306) is deactivated and thus the TMC (104) is directly connected to the brake circuits.

Further, the booster assembly (300) comprises a damping unit (311) which is fluidly connected to the first flow passage (304) i.e. in between the first solenoid valve (303) and the pressure limiting switch (307) for providing smooth pedal feel during initial movement of the brake pedal (102). The damping unit (311) is adapted to receive some amount of hydraulic fluid during initial travel of the brake pedal (103) for providing smooth brake pedal feel.

The operation of the booster assembly (300) and position sensor (101) for fluid flow to the hydraulic braking system (100) is disclosed. The method comprises applying brake pedal (102) with a particular pedal force and effort. On brake application, the position sensor (101) fitted on the brake pedal (102) is activated. The position sensor (101) activates the second solenoid valve (306) through the pressure switch (307) on the accumulator (308). Initially, the pressurised fluid present in the accumulator (308) is supplied to the brake circuits for initial application of brake. Figure 4 illustrates electrical circuitry of the booster assembly (300) and the position sensor (101) in accordance with an embodiment of the present disclosure. When the first solenoid valve (303) is deactivated, the fluid from the TMC (104) flows into the pressure limiting valve (307), and then to the accumulator (308). Then, the fluid flows to the brake circuit for continuing the brake application. Initially, some part of the fluid is configured to pass through the damping device (310) which helps to maintain smooth pedal feel.

The pressure limiting valve (307) which is spring loaded is forced to open when the fluid flow of particular force is received from the TMC (104). The pressure limiting valve (307) allows the fluid to flow into the accumulator (308) through the delivery port of the pressure limiting valve (307). The accumulator (308) is pre-charged with pressure greater than the predefined value. Thus, the accumulator (308) which already contains pressurized fluid provides with extra pressure to the hydraulic braking system (100) even before generation of pressure in TMC. Thus, the pressurized fluid is supplied to the second solenoid valve (306) through the delivery port of the accumulator (308). The second solenoid valve (306) provides the pressurized fluid to the brake circuits for braking action.

During the release of brake, the brake pedal (102) starts to move in reverse direction. Thus, the pedal lever (201) is disconnected from the front arm (203) of the cover cap (204) of position sensor (101) and opens the circuit which in turn deactivates the second solenoid valve (306) of the booster assembly (300). Once the second solenoid valve (306) is deactivated, the flow of fluid from accumulator (308) to the delivery port of the second solenoid valve (306) is disconnected. At the same time the delivery port of TMC (104) is connected to the delivery port of the braking circuit, and thus allows the fluid in the brake system return back to the TMC (104). Due to closing of the delivery port of accumulator (308) immediately as soon as the brake pedal (102) starts moving in reverse direction, the high pressure fluid gets trapped in the accumulator (308). In such case, the accumulator (308) is automatically charged with pressure which settles at a predefined value since some of the fluid gets back to the TMC (104) through the pressure limiting valve (307) until the closing of pressure limiting valve (307). This pressure is used to boost the pressure in the next braking cycle.

In an embodiment of the disclosure, booster assembly (300) may be integrated pressure modulation unit to ensure the boosting action with respect to pedal travel and vacuum level in vacuum booster. For this, system needs to have a pressure sensor, pedal travel sensor, solenoid valve and vacuum level sensor along with Electronic control unit (ECU). Base on the input from these three sensors, a programmed ECU can control the amount of pressure to be administered into the brake system and pressure maintain in accumulator (308). In case of vacuum failed condition, the accumulator can store more pressure in the reservoir and assist the braking function in vacuum failed condition.

FIGURE 5 is an exemplary embodiment of the present disclosure which illustrates a hydraulic clutch actuation system (400) of the vehicle. The clutch actuation system (400) is used in the vehicle for engaging and disengaging the clutch for operation of the gears. The hydraulic clutch actuation system (400) comprises a support bracket (not shown) mounted on firewall of the vehicle for supporting the clutch pedal (401). The support bracket comprises a mounting face and side arms extending from opposing edges of said mounting face. The clutch pedal (401) having an upper end and lower end is pivotally mounted on the support bracket at pivot point through its upper end using a hinge pin, a pedal pad is mounted to a lower end of the clutch pedal (401) for actuating the clutch pedal (401) by the driver/user. The clutch pedal (401) is coupled to a clutch master cylinder (402), wherein an inlet port of the clutch master cylinder is fluidly connected to a hydraulic fluid reservoir (not shown). The clutch master cylinder (402) is configured to generate/intensify the force applied by the driver or user for disengaging the clutch. An outlet port of the clutch master cylinder (402) is fluidly connected to a clutch slave cylinder (404) through a booster assembly (403). The clutch slave cylinder (404) is fluidly connected to a clutch disengagement pin for actuation of the clutch in the vehicle.

The booster assembly (403) used in hydraulic clutch actuation system (400) consist of an inlet port (403a) fluidly connectable to a master cylinder (402) of the hydraulic clutch actuation system (400), and an outlet port (403b) fluidly connectable to a slave cylinder (404). Further, the booster assembly (403) comprises an accumulator (403c) configured to hold pressurised hydraulic fluid. A direction control valve (403d) is provided in the booster assembly (403), and is fluidly connected to the inlet port (403a) through a first flow passage (405), and to the accumulator (403c) through a second flow passage (406). The direction control valve (403d) is configured to selectively route hydraulic fluid to the outlet port (403b) through the first and second flow passages (405 and 406) for clutch actuation based on clutch pedal (401) movement. Further, the accumulator (403c) is fluidly connected to the master cylinder (402) through a by-pass flow line with a non-return valve (408). In an embodiment of the disclosure, the booster assembly (403) may also be called as boost module.

The hydraulic clutch actuation system (400) also comprises a position sensor (407) provisioned on the clutch pedal (401). The position sensor (407) is adapted to detect direction of movement of the clutch pedal (401) i.e. pedal travel. The position sensor (407) detects pedal position during initial forward travel of the clutch pedal (401) during clutch disengagement, and initial return travel of clutch pedal (401)) during clutch engagement. The direction control valve (403d) of the booster assembly (403) is interfaced with a position sensor (407) provided in a clutch pedal (401) of the hydraulic clutch actuation system (400). The direction control valve (403d) is configured to route hydraulic fluid from the accumulator (430c) to the outlet port (403b) up-to predetermined distance of the clutch pedal (401) movement during forward movement of the clutch pedal (401), and route hydraulic fluid from outlet port (403b) to the accumulator (403c) up-to predetermined distance of the clutch pedal (401) movement during return movement of the clutch pedal (401).

Normally, when clutch pedal (401) is in released position the direction control valve (403d) in deactivated state. In this state the clutch master cylinder (402) is directly connected to clutch slave cylinder (404) and the accumulator (403c) is disconnected from the clutch slave cylinder (404). The direction control valve (403d) is configured in such a way that it allows only one connection to the clutch slave cylinder (404) at a time, either from clutch master cylinder (402) or from the accumulator (403c). The position sensor (407) is configured such that it acts as a rotary switch and gives the signal to direction control valve (403d) after pedal actuation in forward direction as well as during return stroke.

FIGURE 6 is an exemplary embodiment of the disclosure which illustrates a sectional view of the clutch pedal (401) with position sensor (407) fitted on a clutch pedal (401) of the hydraulic clutch actuation system (400). As shown in FIGURE. 6 a cover cap (505) is fitted on the clutch pedal boss (502), wherein the cover cap (505) comprises two arms i.e. front arm (504) and rear arm (503). Between front arm (504) and rear arm (503) a switching path (506) is mounted on the cover cap (505), and a specified gap is maintained between the front arm (504) and rear arm (503) and the switching path, this gap is called as non-switching zone (507). A position sensor (407) is fixed on the pedal boss (502) such that it comes between the front arm (504) and rear arm (503) on the cover cap (505). When the clutch pedal (401) is pressed the position sensor (407) rotates along with pedal boss (502) in the switch path (506) between the front arm (504) and rear arm (503). The cover cap (505) can also rotates with the pedal boss (502) when the position sensor (407) pushes either the front arm (507) or rear arm (503) on cover cap (505). In clutch pedal (401) released condition, the position sensor (401) is rested on the non-switching zone (507) after the front arm (504). Since there is no contact between switching element and the position sensor (407), the circuit is not closed and there is no signal to the direction control valve (403d) i.e. direction control valve (403d) may be in deactivated state. In deactivated state of direction control valve (403d), the clutch slave cylinder (404) is directly connected to the clutch master cylinder (402).

When clutch pedal is pressed, the position sensor (407) moves along with the pedal boss (502) and during initial travel slides on the switching element, this closes the contact between the position sensor (407) and the switching element, and thereby gives the signal to the direction control valve (403d). Once direction control valve (403d) gets the signal it gets activates and connect the accumulator (403c) to the clutch slave cylinder (404), at the same time disconnects the clutch master cylinder (402) from the clutch slave cylinder (404). This causes the pressurised fluid stored in the accumulator (403c) to flow to clutch slave cylinder (404) for clutch actuation. This phase continues till the position sensor (407) rides on the switching element i.e. for defined travel of the pedal (401). During this time the fluid flows from clutch master cylinder (402) to the accumulator (403c) though a Non Return Valve (NRV). This NRV is an optional feature to have smooth pedal travel. Once the pedal crosses the specified travel, position sensor (407) comes on the non-switching zone and the signal to direction control valve (403d) gets disconnected, because of no signal from the position sensor (407) the direction control valve (403d) gets deactivated. In this deactivated state of the direction control valve (403d), the clutch master cylinder (402) gets connected with clutch slave cylinder (404), and the accumulator (403c) gets isolated from clutch slave cylinder (404). This connection of clutch master cylinder (402) with the clutch slave cylinder (404) gives the further actuation of clutch on further travel of clutch pedal (401). Also during this further actuation (travel) of pedal (401) the position sensor push the rear arm (503) on the cover cap (505) and entire cover cap (505) moves along the pedal boss (502). The mentioned mechanism describes complete clutch actuation process.

During clutch pedal release, the pedal (407) moves in backward direction, and the position sensor (407) also moves along with pedal boss (502). Hence, the position sensor (407) moves from non-switching zone to the switching path and gives the signal to the direction control valve (403d). Once direction control valve (403d) gets signal from position sensor (407) its gets activated and connect the accumulator (403c) to the clutch slave cylinder (404). Because of the return force of clutch release lever the hydraulic fluid in the clutch slave cylinder (404) is pumped back to the accumulator (403c). This phase continue till the position sensor (407) is on the switching path (element) i.e. for specified return stroke of the pedal (401). Once the pedal (401) moves back through the specified amount of travel the position sensor (407) comes on the non-switching zone, causing the deactivation of the direction control valve (403d). On deactivation of direction control valve (403d), the accumulator (403c) is isolated from clutch slave cylinder (404), and clutch master cylinder (402) is connected to the clutch slave cylinder (404) causing the oil to flow back to the clutch master cylinder (402) and release of the clutch on further release of the clutch pedal (401). During further release of the clutch pedal (401) causes the position sensor (407) to push the front arm of the cover cap (505) and restore the cover cap (505) to the original position w.r.t to the position sensor (407) i.e. pedal boss. This is how the accumulator (403c) is getting charged during clutch release. This pressurised oil in accumulator (403c) is used for pre actuation of the clutch during next clutch actuation. The pre-charging of clutch system improves the response time of clutch actuation system and also can reduce the clutch actuation effort. This system also ensures the smooth engagement of the clutch.

Advantages:
The present disclosure provides a booster assembly for a hydraulic braking system of a vehicle which generates pressurized fluid in advance during each brake application for reducing the response time of braking application. This also reduces brake pedal travel consumed in closing the gap between brake pad /lining and brake disc/drum.

The present disclosure provides a booster assembly for a hydraulic clutch actuation system of a vehicle which generates pressurized fluid in advance during each clutch actuation for reducing the response time of clutch dis-engagement, and can also reduce the clutch actuation effort. This assembly also ensures the smooth engagement of the clutch.

Equivalents:

With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Referral Numerals:

Reference Number Description
100 Hydraulic braking system
101 Brake pedal Position sensor
102 Brake pedal
103 Vacuum booster
104 Master cylinder
105 Hydraulic reservoir
201 Pedal arm
202 Cover cap rear arm
203 Cover cap front arm
204 Cover cap
205 Brake pedal hinging pin
206 Pedal boss
300 Booster assembly for hydraulic brake system
301 Inlet port
302 Outlet port
303 First solenoid valve
304 First flow passage
305 Second flow passage
306 Second solenoid valve
307 Pressure switch
308 Accumulator
309 Pressure sensor
310 Damping unit
311 Non-return valve
312 Battery
400 Hydraulic clutch actuation system
401 Clutch pedal
402 Clutch master cylinder
403 Booster assembly
403a Inlet port
403b Outlet port
403c Accumulator
404 Clutch slave cylinder
405 First flow passage
406 Second flow passage
407 Position sensor
501 Clutch pedal hinging pin
502 Pedal boss
503 Rear arm
504 Front arm
505 Cover cap
506 Switch path
507 Non-switching path
,CLAIMS:We claim:

1. A booster assembly (300) for a hydraulic braking system (100) of a vehicle, the assembly (300) comprising:
an inlet port (301) fluidly connectable to a master cylinder (104) of the hydraulic braking system (100), and an outlet port (302) fluidly connectable to at least one of wheel cylinder and a calliper;
a first solenoid valve (303) fluidly connected to the inlet port (301), the first solenoid valve (303) is configured to selectively route hydraulic fluid to the outlet port (302) through a first and second flow passages (304 and 305);
a second solenoid valve (306) fluidly connected to the outlet port (302) and the first and second flow passages (304 and 305), the second solenoid valve (306) is configured to selectively route hydraulic fluid through the first and second flow passages (304 and 305) based on brake pedal movement (301);
a pressure limiting valve (307) provisioned in the first flow passage (304), wherein the pressure limiting valve (307) is adapted to regulate the flow of the hydraulic fluid through the first flow passage (304); and
an accumulator (308) fluidly connected to the pressure limiting valve (307) and the second solenoid valve (306), wherein the accumulator (308) is configured to hold pressurised hydraulic fluid for supplying the pressurised hydraulic fluid to the outlet port (302) for brake actuation.

2. The assembly as claimed in claim 1 comprises a pressure switch (309) provided in the accumulator (308) to determine the pressure of the hydraulic fluid in the accumulator (308).

3. The assembly as claimed in claim 2, wherein the pressure switch (309) is interfaced with the first solenoid valve (303) and the second solenoid valve (306) and transmits a signal comprising pressure of the hydraulic fluid.

4. The assembly as claimed in claim 3, wherein the first solenoid valve (303) routes the hydraulic fluid through the first passage (304) if the pressure of the hydraulic fluid is more than a predetermined value.

5. The assembly as claimed in claim 3, wherein the first solenoid valve (303) routes the hydraulic fluid through the second passage (305) if the pressure of the hydraulic fluid is less than a predetermined value.

6. The assembly as claimed in claim 1, wherein the second solenoid valve (306) is interfaced with a position sensor (101) provided in a brake pedal (102) of the hydraulic braking system (100).

7. The assembly as claimed in claim 6, wherein the second solenoid valve (306) routes the hydraulic fluid from the first flow passage (304) to the outlet port (302) during forward movement of the brake pedal (102).

8. The assembly as claimed in claim 6, wherein the second solenoid valve (306) routes the hydraulic fluid from the outlet port (302) to the master cylinder (104) through the second passage (305) during return movement of the brake pedal (102).

9. The assembly as claimed in claim 1 comprises a damping unit (310) fluidly connected to the first flow passage (304).

10. The assembly as claimed in claim 1, wherein the accumulator (308) is fluidly connected to the second flow passage (305) through a non-return valve (311).

11. The assembly as claimed in claim 1, wherein the pressure limiting valve (307) allows the flow of the hydraulic fluid through the first passage (304) if the pressure of the hydraulic fluid is more than the predetermined value.

12. The assembly as claimed in claim 1, wherein the accumulator (308) supplies pressurised hydraulic fluid to the outlet port (302) for brake application up-to predetermined distance of brake pedal (102) movement during of forward movement of the brake pedal (102).

13. A hydraulic braking system (100) for a vehicle, the system (100) comprises:
a brake pedal (102) pivoted to firewall of the vehicle, wherein the brake pedal (102) is configured to move between first position and position for operating the braking system;
a vacuum booster (103) coupled to the brake pedal (102);
a master cylinder (104) fluidly connected to a hydraulic fluid reservoir (105), wherein the master cylinder (104) is linked to the vacuum booster (103) to pressurise the hydraulic fluid; and
a booster assembly (106) fluidly connected to the master cylinder (104) and at least one of wheel cylinder and a calliper for supplying the pressurised hydraulic fluid for brake actuation up-to predetermined distance of brake pedal (102) movement during of forward movement of the brake pedal (102).

14. The system as claimed in claim 13 comprises a position sensor (101) provisioned on the brake pedal (102) to detect the direction of movement of the brake pedal (102).

15. The system as claimed in claim 14, wherein the position sensor (101) is interfaced with the booster assembly (106).

16. A vehicle comprising a booster assembly for a hydraulic braking system as claimed in claim 1.

17. A booster assembly (403) for a hydraulic clutch actuation system (400) of a vehicle, the assembly (403) comprising:
an inlet port (403a) fluidly connectable to a master cylinder (402) of the hydraulic clutch actuation system (400), and an outlet port (403b) fluidly connectable to a slave cylinder (404);
an accumulator (403c) configured to hold pressurised hydraulic fluid; and
a direction control valve (403d) fluidly connected to the inlet port (403a) through a first flow passage (405), and to the accumulator (403c) through a second flow passage (406), wherein the direction control valve (403d) is configured to selectively route hydraulic fluid to the outlet port (403b) through the first and second flow passages (405 and 406) for clutch actuation based on clutch pedal (401) movement.

18. The assembly as claimed in claim 17, wherein the direction control valve (403d) is interfaced with a position sensor (407) provided in a clutch pedal (401) of the hydraulic clutch actuation system (400).

19. The assembly as claimed in claim 17, wherein the direction control valve (403d) is configured to route hydraulic fluid from the accumulator (430c) to the outlet port (403b) up-to predetermined distance of the clutch pedal (401) movement during forward movement of the clutch pedal (401).

20. The assembly as claimed in claim 17, wherein the direction control valve (403d) is configured to route hydraulic fluid from outlet port (403b) to the accumulator (403c) up-to predetermined distance of the clutch pedal (401) movement during return movement of the clutch pedal (401).

21. The assembly as claimed in claim 17, wherein the accumulator (403c) is fluidly connected to the first flow passage (405) through a non-return valve (408).

22. A hydraulic clutch actuation system (400) for a vehicle, the system (400) comprises:
a clutch pedal (401) pivoted to firewall of the vehicle, wherein the clutch pedal (401) is configured to be moved between the first position and the second position for engaging and disengaging a clutch;
a master cylinder (402) fluidly connected to a hydraulic fluid reservoir; and
a booster assembly (403) fluidly connected to the master cylinder (402) and clutch slave cylinder (404) for supplying the pressurised hydraulic fluid for clutch actuation.

23. The system as claimed in claim 22 comprises a position sensor (407) provisioned on the clutch pedal (401) to detect the direction of movement of the clutch pedal (401).

24. The system as claimed in claim 19, wherein the position sensor (401) is interfaced with the booster assembly (403).

25. A vehicle comprising a booster assembly for a hydraulic clutch actuation system as claimed in claim 17.