DESC:FIELD
The present disclosure relates to the field of valves for vehicles.
DEFINITION
H-split brake configuration – The term “H-split brake configuration” hereinafter in the specification refers to a braking configuration in which one section of a master cylinder is used to pressurize front caliper pistons to apply braking force on front wheels of a vehicle, and the other section of the master cylinder is used to pressurize rear caliper pistons to apply braking force on rear wheels of the vehicle.
X-split brake configuration – The term “X-split brake configuration” hereinafter in the specification refers to a braking configuration which includes a first hydraulic line to serve brakes of right front wheel and left rear wheel, and a second hydraulic line to serve brakes of left front wheel and right rear wheel.
Proportioning valve – The term “proportioning valve” hereinafter in the specification refers to a valve typically used in vehicles to reduce brake fluid pressure on brakes.
BACKGROUND
In a hydraulic braking system, in certain scenarios, there is a significant weight transfer to the front wheels of a vehicle in braking condition. This primarily causes locking of the rear wheels, thereby hampering the vehicle stability. Conventionally, a proportioning valve is provided to limit the rear brake utilization. There exist various kinds of pressure regulator valves. Typically, a load sensitive proportioning valve and a twin load sensitive proportioning valve are used widely in vehicles based on the brake tubing layout, i.e., an H-split and an X-split brake tubing layout. Each of the aforementioned valves associated with corresponding brake tubing/ routing layout has their own set of disadvantages. Typically, an X-split brake configuration is preferred against the H-split brake configuration for the ease for achieving higher deceleration during secondary brake performance scenarios. However, this higher deceleration is associated with an induced vehicle sway unlike in the case with the H-split configuration. Typically, the conventional twin load sensitive proportioning valve (TLSPV) is used in hydraulic braking system vehicle with X-split brake configuration. The valve is used to proportionate brake force between front and rear wheels to ensure vehicle stability during braking event. However, the conventional twin load sensitive proportioning valve imparts induced sway due to imbalance in brake force between diagonally opposite front and rear wheel ends in a circuit failed condition.
Therefore, there is felt a need of a valve assembly for braking system of a vehicle that alleviates the aforementioned drawbacks of the conventional valves.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the preset disclosure is to provide a valve assembly for braking system that is used across wide range of vehicles and braking configurations.
Another object of the preset disclosure is to provide a valve assembly for braking system that is reduces induced sway in vehicles.
Another object of the preset disclosure is to provide a valve assembly for braking system that is reduces sway in vehicles.
Another object of the preset disclosure is to provide a valve assembly for braking system that improves vehicle stability.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure envisages a valve assembly for braking system of a vehicle. The valve assembly is configured to be coupled to a primary braking circuit and a secondary braking circuit fluidly coupled to a master cylinder. The master cylinder is configured to pressurize fluid for applying braking force. The primary braking circuit and the secondary braking circuit are configured to supply braking force to two front brakes and two rear brakes. The valve assembly is configured such that, in the event of failure of either the primary braking circuit or the secondary braking circuit, equal pressure is supplied to the brakes operated by the braking circuit that has not failed and therefore equal braking force is applied.
The valve assembly comprises a valve body, a load sensing lever, a first plunger and a second plunger. The valve body has a first bore portion and a second bore portion configured thereon. The first bore portion has a primary braking circuit inlet port, a primary braking circuit outlet port corresponding to the primary braking circuit and a secondary braking circuit bypass port fluidly coupled to the secondary braking circuit. The second bore portion has a secondary braking circuit inlet port, a secondary braking circuit outlet port corresponding to the secondary braking circuit and a primary braking circuit bypass port fluidly coupled to the secondary braking circuit. The load sensing lever is configured to displace proportional to distribution of load along the longitudinal direction of the vehicle. The load sensing lever is pivoted at a pivot mounted on the valve body. The first plunger is disposed in the first bore portion and a second plunger is disposed in the second bore portion. The first plunger and the second plunger are coupled to the load sensing lever, and are configured to slide along the corresponding bore portions to control the distribution of pressure of the pressurized fluid between front and rear brakes of each of the pairs and between the primary braking circuit and the secondary braking circuit, to limit the sway induced due to application of unequal brake torque.
In an embodiment, the first bore portion is defined by a first stepped bore having a first step configured thereon to receive the first plunger therein. The first plunger has a first stepped portion. The first stepped bore is configured to receive a first grooved guide bush and a first metering valve. The first grooved guide bush is secured to an operative top surface of the first stepped bore with a first locking clip. The first metering valve disposed between a first plunger stepped portion and the first stepped bore. The first metering valve is configured to allow passage of pressurized fluid from the primary braking circuit inlet port to the primary braking circuit outlet port.
Also, the second bore portion is defined by a second stepped bore having a second step configured thereon to receive the second plunger therein. The second plunger has a second stepped portion. The second bore portion is configured to receive a second grooved guide bush and a second metering valve. The second grooved guide bush is secured to an operative top surface of the second stepped bore with a second locking clip. The second metering valve is disposed between the second plunger stepped portion and the second stepped bore. The second metering valve is configured to allow passage of pressurized fluid from the secondary braking circuit inlet port to the secondary braking circuit outlet port.
In an embodiment, a first bleeding port corresponding to the primary braking circuit is configured on the valve body for removing air bubbles from the primary braking circuit. Also, a second bleeding port corresponding to the secondary braking circuit is configured on the valve body. The second bleeding port is configured to remove air bubbles from the secondary braking circuit.
In an embodiment, the valve body is provided with an extended arm to mount a counter spring thereon, wherein the counter spring is coupled to the load sensing lever.
In an embodiment, the valve assembly includes a flexible dust cover mounted on the assembly. The dust cover is configured to cover the plunger-receiving apertures of the first bore portion and the second plunger of the valve body.
In an embodiment, the valve assembly includes a clamp spring configured to clamp the dust cover to the valve body.
In an embodiment, the sensing lever has a load sensing spring coupled to a free end thereof. The load sensing spring is coupled to a suspension assembly of the vehicle.
In one embodiment, the primary braking circuit is connected to a first front brake and a first rear brake that is positioned diagonally opposite to the first front brake, and the secondary braking circuit is connected to a second front brake and a second rear brake that is positioned diagonally opposite to the second front brake. In another embodiment, the primary braking circuit is connected to both front brakes and both rear brakes and the secondary braking circuit is connected to both front brakes and both rear brakes.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
A valve assembly for braking system of a vehicle, of the present disclosure, will now be described with the help of the accompanying drawing, in which:
Figure 1 shows a schematic arrangement of a braking system of a vehicle of the present disclosure associated with X-split configuration hydraulic braking system of an automobile vehicle;
Figure 2 illustrates an isometric view of the valve assembly of the present disclosure;
Figure 3 illustrates a detailed view ‘A’ of the valve body of the assembly of Figure 2;
Figure 4 illustrates a front view of a valve body of the assembly of the present disclosure;
Figure 5 illustrates a plan view of the valve body of the assembly of Figure 4;
Figure 6 illustrates a longitudinal sectional view of the valve for a primary braking circuit, taken along sectional line A-A on Figure 4;
Figure 7 illustrates a longitudinal sectional view of the valve for a secondary braking circuit, taken along sectional line B-B on Figure 5;
Figure 8 illustrates a transverse sectional view of the valve for bypass port and bleeding ports arrangement for primary and secondary braking circuits, taken along sectional line C-C on Figure 4; and
Figure 9 and Figure 10 illustrates a comparative charts comparing performance of a conventional valve assembly and the valve assembly of the present disclosure.
LIST OF REFERENCE NUMERALS
S. No. PART DESCRIPTION
1 Brake pedal
2 Master cylinder
3 Front wheels
4 Rear wheels
5 T-joint
6 Integrated pressure sensing twin load Sensitive proportioning valve (ITLSPV)
7 Primary braking circuit
8 Secondary braking circuit
9 Valve body
10 Load sensing lever
11 Load sensing spring
12 Counter spring
13 Dust cover
14 Clamp spring
15 Pivot
16A, 16B First and second plunger
17 Primary braking circuit stepped bore
18 Secondary braking circuit stepped bore
19 Primary braking circuit inlet port
20 Primary braking circuit outlet port
21 Secondary braking circuit bypass port
22 Secondary braking circuit bleeding port
23 Secondary braking circuit inlet port
24 Secondary braking circuit outlet port
25 Primary braking circuit bypass port
26 Primary braking circuit bleeding port
27A, 27B First and second locking clips
28A, 28B First and third O-rings
29A, 29B First and second guide bushes
30A, 30B First and second restrain springs
31A, 31B First and second metering valves
32A, 32B Second and fourth O-rings
DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details, are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," “including,” and “having,” are open ended transitional phrases and therefore specify the presence of stated features, Elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, elements, components, and/or groups thereof.
When an element is referred to as being "mounted on," “engaged to,” "connected to," or "coupled to" another element, it may be directly on, engaged, connected or coupled to the other element. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed elements.
The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element, component, region, layer or section from another component, region, layer or section. Terms such as first, second, third etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.
Terms such as “inner,” “outer,” "beneath," "below," "lower," "above," "upper," and the like, may be used in the present disclosure to describe relationships between different elements as depicted from the figures.
The present disclosure relates to a valve assembly, more specifically, the Twin load sensitive proportioning valve (TLSPV) which is used generally in hydraulic braking system vehicle with X-Split brake configuration. This is used to proportionate brake force between front and rear wheels (3, 4) to ensure vehicle stability during braking event. While the conventional valve assembly meets the specified stability performance during braking in service condition, however imparts induced sway due to imbalance in brake force between front and rear diagonally opposite wheel ends in circuit failed condition, i.e., when either a primary or a secondary braking circuit fails.
The present disclosure aims to provide a valve assembly that mitigates the limitations of the conventional valve assembly by detecting the secondary brake condition on vehicle and helps in reducing the imbalance between front and rear brake forces, which in turn helps to minimize the induced sway behavior in the vehicle during a brake circuit failed brake condition. The present disclosure thus helps in improving overall vehicle stability and occupant’s safety.
Vehicle sway during secondary braking event is caused due to location of the centre of gravity, vehicle architecture, weight distribution, and imbalance in brake force between front wheels (3) and rear wheels (4) during the secondary braking event.
Of the above stated reasons, the imbalance in the braking is the major contributor to the vehicle sway.
And also, there is no limitation of the application of this concept on different vehicles in which brakes are hydraulically operated.
The design of the proposed valve assembly is such that it reduces the imbalance to the maximum possible extent and thus reduces the sway behavior of the vehicle. It also supports in enhancing vehicle stability during secondary braking event in X-Split vehicles, and thus enhances the advantages of X-Split configuration design over H-Split.
The current layout of X-Split configuration has primarily only one set back in comparison with H-Split configuration, and as mentioned the sway in the vehicle can be optimized by the utilization of the proposed valve assembly of the present disclosure.
Typical comparison of H and X-Split braking scenarios, is given in the following table.
Table -1
Parameter H-Split Layout X-Split Layout
Deceleration level Less More
Pedal Effort required to achieve specified deceleration More Less
Vehicle sway induced during braking Less More

The present disclosure thus aims to provide valves that reduce the excess sway induced in X-Split layout.
Hydraulic braking system components of an automobile can be classified into three categories.
1. Actuation system: - Components which will convert the input of driver to that pressure of hydraulic fluid.
2. Transmission system: - Bundy’s and hoses which will transfer pressurized brake fluid to the brakes.
3. Foundation braking system: - Components which will convert pressurized hydraulic brake fluid energy in to braking force at wheels.
The performance of the braking system is critical for safety of occupant as well as other persons. The weak link in braking system is the hydraulic braking fluid transmission system, hence a split is provided in the braking system. In general, an automobile vehicle may have H-Split or X-Split brake configuration or other type of split architecture. Braking system layout selection is mainly governed by the regulatory requirements. But OEMs also strive to create an enhanced braking/ driving comfort and sway is a behavior which driver of any vehicle will be bothered by, and during the circuit failed condition testing of a hydraulic braking system vehicle with X-Split brake configuration, due to imbalance in the braking forces between front and rear, sway is induced in the vehicle, leading to panic and demanding skills to control the vehicle.
Overall, the invention is aimed at:
• Reducing the induced sway during secondary brake performance;
• Implementing on wide range of vehicles, across hydraulic braking system vehicles; and
• Easily adopting on an existing X-Split configuration and other type of split architecture vehicles.
A preferred embodiment of a valve assembly, of the present disclosure, for braking system of a vehicle having an X-Split configuration will now be described in detail with reference to Figure 1 through Figure 10.
The present disclosure envisages a valve assembly for braking system of a vehicle. The valve assembly of the present disclosure is configured to be coupled to a primary braking circuit and a secondary braking circuit fluidly coupled to a master cylinder. The master cylinder is configured to pressurize fluid for applying braking force. The primary braking circuit and the secondary braking circuit are configured to supply braking pressure to two front brakes and two rear brakes. The valve assembly is configured such that, in the event of failure of either the primary braking circuit or the secondary braking circuit, equal pressure is supplied to the brakes operated by the braking circuit that has not failed and therefore the valve assembly applies equal braking force to the brakes connected to the braking circuit that has not failed.
In one embodiment, the primary braking circuit is connected to a first front brake and a first rear brake that is positioned diagonally opposite to the first front brake, and the secondary braking circuit is connected to a second front brake and a second rear brake that is positioned diagonally opposite to the second front brake. In another embodiment, the primary braking circuit is connected to both front brakes and both rear brakes and the secondary braking circuit is connected to both front brakes and both rear brakes.
Figure 1 illustrates a schematic arrangement of a braking system of a vehicle comprising components such as a brake pedal (1), a master cylinder (2), front wheels (3), rear wheels (4), T-joints (5), a valve assembly (6), a primary braking circuit (7) and a secondary braking circuit (8).
The master cylinder (2) is a control device that converts force applied on the brake pedal into hydraulic pressure. In an embodiment, the master cylinder (2) is configured to convert the force applied by a driver on brakes of the vehicle into pressurize fluid. The master cylinder (2) comprises a primary braking circuit (7) and a secondary braking circuit (8). During normal braking conditions, i.e., when the brake pedal (1) is pressed, both the circuits (7, 8) are activated and the pressurized fluid flow towards the front wheels (3) and the rear wheels (4) diagonally through the valve assembly (6) and primary and secondary braking circuit pipe connections. In a condition when the secondary braking circuit pipe connections fail, the fluid in the secondary braking circuit (8) becomes unavailable and creates a pressure difference between the fluid carried in the primary braking circuit (7) and the secondary braking circuit (8). The pressure difference results in unequal brake torque which causes the vehicle to sway. The valve assembly (6) senses this pressure difference, and allows the distribution of the difference in pressure to the front wheels (3) and rear wheels (4) diagonally.
In an embodiment, the valve assembly (6) of the present disclosure is a pressure regulated valve. Particularly, the valve assembly (6) is an Integrated Pressure Sensing Twin Load Sensitive Proportioning Valve (ITLSPV).
The valve assembly (6) is coupled to the primary braking circuit (7) and the secondary braking circuit (8) of the master cylinder (2). The assembly (6) comprises a valve body (9), a pivot (15), a load sensing lever (10), a first plunger (16A), and a second plunger (16B). The valve body (9) has a first stepped bore portion and a second stepped bore portion configured thereon. The first stepped bore portion is configured to correspond to the primary braking circuit (7) and the second stepped bore portion is configured to correspond to the secondary braking circuit (8). The pivot (15) is mounted on the valve body (9). The pivot (15) is configured to oscillate with travel of vehicle suspension. The load sensing lever extends from the pivot (15). The load sensing lever (10) has a load sensing spring (11) coupled to a free end thereof. The lever (10) is configured to oscillate with the oscillation of the pivot (15). The first plunger (16A) is disposed in the first stepped bore portion and a second plunger (16B) is disposed in the second stepped bore portion provided in the valve body (9). The first plunger (16A) and the second plunger (16B) are coupled to the load sensing lever (10). The first plunger (16A) and the second plunger (16B) are configured to slide in a vertical direction in order to control the flow of the pressurized fluid from the master cylinder (2) and limit the sway induced due to application of the unequal brake torque.
Referring to Figure 4, the valve body (9) includes a primary braking circuit inlet port (19), a primary braking circuit outlet port (20), a secondary braking circuit inlet port (23), and a secondary braking circuit outlet port (24) configured thereon, to allow the passage of the pressurized fluid from the master cylinder (2).
Figure 6 illustrates a sectional view of the valve body (9) to bring out the features of the first stepped bore portion. The first stepped bore portion is defined by a first stepped bore (17) having a first step configured thereon to receive a first plunger (16A) therein. The first stepped bore portion includes a first grooved guide bush (29A) and a first metering valve (31A). The first grooved guide bush (29A) is secured to an operative top surface of the first stepped bore (17) with a first locking clip (27A). The first plunger (16A) has a first stepped portion. The first metering valve (31A) is disposed between the first plunger stepped portion and the first stepped bore (17). The first metering valve (31A) is configured to allow passage of pressurized fluid from the primary braking circuit inlet port (19) to the primary braking circuit outlet port (20).
Referring to Figure 8, a first bleeding port (26) corresponding to the primary braking circuit (7) is configured on the valve body (9) for removing air bubbles from the primary braking circuit (7). The valve body (9) further includes a primary braking circuit bypass port (25) corresponding to the primary braking circuit (7). The primary braking circuit port (25) is configured to allow the pressure of the fluid in the secondary braking circuit (8) to act on the first plunger (16A). Depending on the pressure of the fluid in the secondary braking circuit (8), the first plunger slides in the first stepped bore (17) to regularize the pressure of the fluid in the primary braking circuit (7).
In an embodiment, a first O-ring (28A) is provided on grooves of the first guide bush (29) to seal the first stepped bore (17). In another embodiment, a second O-ring (32A) is provided beneath the first metering valve (31A) to prevent fluid communication between the primary braking circuit (7) and the secondary braking circuit (8). In another embodiment, the valve body (9) includes a first restrain spring (30A).
Figure 7 illustrates a sectional view of the valve body (9) to bring out the features of the second stepped bore portion. The second stepped bore portion is defined by a second stepped bore (18) having a second step configured thereon to receive a second plunger (16B) therein. The second stepped bore portion includes a second grooved guide bush (29B) and a second metering valve (31B). The second grooved guide bush (29B) is secured to an operative top surface of the second stepped bore (18) with a second locking clip (27B). The second plunger (16B) has a second stepped portion. The second metering valve (31B) is disposed between the second plunger stepped portion and the second stepped bore (18). The second metering valve (31B) is configured to allow passage of pressurized fluid from the secondary braking circuit inlet port (23) to second circuit outlet port.
Referring to Figure 8, a second bleeding port (22) corresponding to the secondary braking circuit (8) is configured on the valve body (9) for removing air bubbles from the secondary braking circuit (8).
The valve body (9) includes a secondary braking circuit bypass port corresponding to the secondary braking circuit (8). The secondary braking circuit bypass port is configured to allow the pressure of the fluid in the primary braking circuit (7) to act on the second plunger (16B). Depending on the pressure of the fluid in the primary braking circuit (7), the second plunger (16B) slides in the second stepped bore (18) to regularize the pressure of the fluid in the secondary braking circuit (8).
In an embodiment, a third O-ring (28B) is provided on grooves of the second guide bush (29) to seal the second stepped bore (18). In another embodiment, a fourth O-ring (32B) is provided beneath the second metering valve (31B) to prevent fluid communication between the secondary braking circuit (8) and the primary braking circuit (7). In another embodiment, the valve body (9) includes a second restrain spring (30B).
The valve body (9) of the present disclosure is configured to detect the pressure of the fluid passing through the primary braking circuit (7) and the secondary braking circuit (8), and accordingly modulate the pressure of the fluid that is circulated to the rear wheels (4). In an operative condition, where the fluid in either the primary braking circuit (7) or the secondary braking circuit (8) is non-pressurized, the sway induced in the vehicle, by unequal brake torque that is distributed about centre of gravity of the vehicle, is controlled, thus curbing the panic that would have been otherwise caused to the driver/passenger of the vehicle.
Referring to Figure 6, the primary braking circuit inlet port (19) is connected to the primary braking circuit (7) of the master cylinder (2) through T-joints (5) and the primary braking circuit (7). The primary braking circuit outlet port (20) is connected to the rear wheels (4). Similarly, the secondary braking circuit bypass port (21) is connected to the secondary braking circuit (8) of the master cylinder (2).
The first plunger (16A) is guided in the first guide bush (29) which is secured with first locking clip (27A) in the groove of the first stepped bore (17). The first plunger (16A) slides into the first stepped bore (17) against the pressurized fluid that is passed from the master cylinder (2) through the primary braking circuit inlet port (19) and the secondary braking circuit bypass port (21). The first restrain spring (30A) is acting on the sliding plunger (16) against pressurized fluid. The first metering valve (31A) is seated on the first plunger (16A) which allows the pressurized fluid from primary braking circuit inlet port (19) to the primary braking circuit outlet port (20) based on the first plunger (16A) movement. The second O-ring (32A) seals the region connecting the primary braking circuit (7) and the secondary braking circuit (8). On the other side of the second O-ring (32A), the pressurized fluid in the secondary braking circuit (8) acts on the second plunger (16B) from the secondary braking circuit bypass port (21). In an embodiment, when the secondary braking circuit (8) fails there is no fluid in the secondary braking circuit (8). Hence, the pressurized fluid cannot pass from the secondary bypass port (21) and prevents throttling from happening at the first metering valve (31A), thereby allowing equal pressure from the primary braking circuit inlet port (19) to pass through primary braking circuit outlet port (20). As a result, when the secondary brake is in operating conditions, the pressure between the braking of the front wheels (3) and the braking of the rear wheels (4) remains the same.
Referring to Figure 7, the secondary braking circuit inlet port (23) is connected to the secondary braking circuit (8) of the master cylinder (2) through T-joints (5) and the secondary braking circuit (8). The primary braking circuit bypass port (25) is connected to the primary braking circuit (7) of the master cylinder (2). The secondary braking circuit outlet port (24) is connected to the rear wheels (4).
Similarly, the second plunger (16B) is guided in the second guide bush (29) which is locked with second locking clip (27B) in the groove of the second stepped bore portion. The second plunger (16B) slides in the second stepped bore (18) against the pressurized fluid that is passed from the master cylinder (2) through the secondary braking circuit inlet port (23) and the primary braking circuit bypass port (25). The second restrain spring (30B) acts on the sliding second plunger (16B) against pressurized fluid. The second metering valve (31B) is disposed on the sliding second plunger (16B) to allow the pressurized fluid to flow from secondary braking circuit inlet port (23) into the secondary braking circuit outlet port (24) based on the movement of the second plunger (16B). The fourth O-ring (32B) seals the region connecting the secondary braking circuit (8) and the primary braking circuit (7). On the other side of the fourth O-ring (32B), pressurized fluid acts on the second plunger (16B) from the primary braking circuit bypass port (25). In a condition where, the primary braking circuit (7) fails, there is no fluid in primary braking circuit (7). Hence, pressurized fluid is not passed from the primary braking circuit bypass port (25) and throttling at the second metering valve (31B) is prevented, thereby allowing equally pressurized fluid from the secondary braking circuit inlet port (23) to pass through the secondary braking circuit outlet port (24). As a result, when the secondary brake is in operating conditions, the pressure between front wheels (3) and rear wheels (4) braking remains the same. Hence, the sway induced due to the imbalance in brake force reduces to the maximum possible extent.
The valve body (9) is provided with an extended arm to mount a counter spring (12) thereon. The counter spring (12) is coupled to the load sensing lever (10) to position the first metering valve (31A) and the second metering valve (31B) based on the oscillation of load sensing lever (10). Further, the first metering valve (31A) is positioned using counter spring (12), load sensing spring (11) and load sensing lever (10) which is hinged at the pivot (15).
In an embodiment, the assembly (6) includes a flexible dust cover (13) mounted on the assembly (6) to protect the valve body (9) from pollutants. In another embodiment, the assembly (6) further includes a clamp spring (14) configured to clamp the dust cover (13) to the valve body (9).
Figure 9 and Figure 10 illustrates graphs comparing performance of a conventional valve assembly and the valve assembly (6) of the present disclosure.
Normal Twin Load Sensitive Proportioning valve (TLSPV) does not provide a provision to sense brake fluid pressure in both the primary braking circuit (7) and the secondary braking circuit (8). However, the valve assembly (6) of the present disclosure will allow the sensing of the brake fluid pressure in the circuits (7, 8). This will help in reducing the induced sway during secondary brake performance.
It is seen that the valves of the present disclosure are easy to operate, are simple in configuration, improve safety of a vehicle, easy to service, and easy to retrofit in existing braking systems.
Further, the valves of the present disclosure can be used across any type of brake split configuration; and more than one kind of hydraulic brake split configurations. The primary and secondary braking circuit bypass ports (21, 25) and the second and first bleeding ports (22 and 26) are integrated to the valve. Further, the bypass ports (21, 25) can be integrated to the other circuit portion in the main housing. Different types of springs can be used in the valves. The valve assembly (6) of the present disclosure can be used across wide range of vehicles and applications. Further, the valve assembly (6) of the present disclosure can be used on the right hand drive, and left hand drive vehicles without any change. In an embodiment, mechanical, electrical or electromechanical control can be employed for actuating the load sensing lever (10) and the plungers (16A, 16B).
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
TECHNICAL ADVANCES AND ECONOMICAL SIGNIFICANCE
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a valve assembly for braking system of a vehicle, that:
• is used across wide range of vehicles and braking configurations;
• is reduces induced sway in vehicles;
• is reduces sway in vehicles; and
• improves vehicle stability.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.
,CLAIMS:WE CLAIM:
1. A valve assembly (6) for braking system of a vehicle, said valve assembly (6) configured to be coupled to a primary braking circuit (7) and a secondary braking circuit (8) fluidly coupled to a master cylinder (2), said master cylinder (2) configured to pressurize fluid for applying braking force, said primary braking circuit (7) and said secondary braking circuit (8) configured to supply braking pressure to two front brakes and two rear brakes, said valve assembly (6) configured such that, in the event of failure of either the primary braking circuit (7) or the secondary braking circuit (8), equal pressure is supplied to the brakes operated by the braking circuit that has not failed and therefore apply equal braking force.
2. The valve assembly as claimed in claim 1, wherein said valve assembly (6) comprises:
• a valve body (9) having a first bore portion (9A) and a second bore portion (9B) configured thereon;
o said first bore portion (9A) having a primary braking circuit inlet port (19), a primary braking circuit outlet port (20) corresponding to said primary braking circuit (7) and a secondary braking circuit bypass port (21) fluidly coupled to said secondary braking circuit (8); and
o a second bore portion (9B) having a secondary braking circuit inlet port (23), a secondary braking circuit outlet port (24) corresponding to said secondary braking circuit (8) and a primary braking circuit bypass port (25) fluidly coupled to said secondary braking circuit (8);
• a load sensing lever (10) configured to displace proportional to distribution of load along the longitudinal direction of the vehicle, said load sensing lever (10) pivoted at a pivot (15) mounted on said valve body (9); and
• a first plunger (16A) disposed in said first bore portion (9A) and a second plunger (16B) disposed in said second bore portion (9B), said first plunger (16A) and said second plunger (16B) coupled to said load sensing lever (10), and configured to slide along the corresponding bore portions to control the distribution of pressure of the pressurized fluid between front and rear brakes of each of said pairs and between said primary braking circuit (7) and said secondary braking circuit (8), to limit the sway induced due to application of unequal brake torque.
3. The assembly (6) as claimed in claim 2, wherein said first bore portion (9A) is defined by a first stepped bore (17) having a first step configured thereon to receive said first plunger (16A) therein and said first plunger (16A) has a first stepped portion, said first stepped bore (17) configured to receive:
• a first grooved guide bush (29A) secured to an operative top surface of said first stepped bore (17) with a first locking clip (27A); and
• a first metering valve (31A) disposed between a first plunger stepped portion and said first stepped bore (17), said first metering valve (31A) configured to allow passage of pressurized fluid from said primary braking circuit inlet port (19) to said primary braking circuit outlet port (20).
4. The assembly (6) as claimed in claim 2, wherein a first bleeding port (26) corresponding to said primary braking circuit (7) is configured on said valve body (9) for removing air bubbles from said primary braking circuit (7).
5. The assembly (6) as claimed in claim 2, wherein said second bore portion (9B) is defined by a second stepped bore (18) having a second step configured thereon to receive said second plunger (16B) therein and said second plunger (16B) has a second stepped portion, said second bore portion (9B) configured to receive:
• a second grooved guide bush (29B) secured to an operative top surface of said second stepped bore (18) with a second locking clip (27B); and
• a second metering valve (31B) disposed between a second plunger stepped portion and said second stepped bore (18), said second metering valve (31B) configured to allow passage of pressurized fluid from said secondary braking circuit inlet port (23) to said secondary braking circuit outlet port (24).
6. The assembly (6) as claimed in claim 2, wherein a second bleeding port (22) corresponding to said secondary braking circuit (8) is configured on said valve body (9), said second bleeding port (22) configured to remove air bubbles from said secondary braking circuit (8).
7. The assembly (6) as claimed in claim 2, wherein said valve body (9) is provided with an extended arm to mount a counter spring (12) thereon, wherein said counter spring (12) is coupled to said load sensing lever (10).
8. The assembly (6) as claimed in claim 2, which includes a flexible dust cover (13) mounted on said assembly, said dust cover (13) configured to cover the plunger-receiving apertures of said first bore portion (9A) and said second plunger (16B) of said valve body (9).
9. The assembly (6) as claimed in claim 8, which includes a clamp spring (14) configured to clamp said dust cover (13) to said valve body (9).
10. The assembly (6) as claimed in claim 2, wherein said sensing lever (10) has a load sensing spring (11) coupled to a free end thereof, said load sensing spring (11) coupled to a suspension assembly of the vehicle.
11. The assembly (6) as claimed in claim 2, wherein said primary braking circuit is connected to a first front brake and a first rear brake that is positioned diagonally opposite to said first front brake, and said secondary braking circuit is connected to a second front brake and a second rear brake that is positioned diagonally opposite to said second front brake.
12. The assembly (6) as claimed in claim 2, wherein said primary braking circuit is connected to both front brakes and both rear brakes and said secondary braking circuit is connected to both front brakes and both rear brakes.