Claims:CLAIMS

We claim:

1. A hill drive away assist comprising of :
an electronic-control module (1);
an in-built inclination sensor (10) in the electronic-control module (1);
a hydraulic control module (2);
a cartridge (8) in the hydraulic control module (2);

characterized in that the hydraulic control module (2) can be connected to the existing hydraulic brake system of a vehicle consisting of a brake pedal (4), a brake pressure source (5), a brake fluid pipeline (7), wheel end brakes (caliper or wheel cylinder) (6) and an antilock braking system (9).

2. The hill drive away assist as claimed in Claim 1 wherein the cartridge (8) in the hydraulic control module (2)is activated through signals from the electronic control module(1). It is positioned in any one of the brake circuit between the brake pressure source (5) and wheel end brakes (6) in a vehicle without ABS / or positioned between brake pressure source (5) and ABS (9) in a vehicle with ABS (9).

3. The hill drive away assist as claimed in Claim 1 and working thereof wherein the hydraulic control module (2), when activated by the electronic control module (1), holds a brake pressure (P2,P3) at the wheel end brakes (6) connected to a corresponding hydraulic circuit, even when a driver has released the brake pedal (4), by blocking a return flow of brake fluid from the wheel end brakes (6) connected to the corresponding hydraulic circuit of a brake system to the brake pressure source (5), if brake pedal (4) is pressed; andthe speed of the vehicle is less than set threshold; and the vehicle is in a consistent ascent or descent; andthe gear position signal indicates a possible rollback or roll-forward.

4. The hill drive away assist as claimed in Claim 1 and working thereof wherein In the activated condition, the hydraulic control module (2) and the electronic control module (1)allows fluid to flow from the brake pressure source (5) to the wheel end brakes(6) connected to the corresponding hydraulic circuit of the brake system, to increase the brake pressure (P2,P3) at the wheel end brakes (6) connected to the corresponding hydraulic circuit, which is generated by increase in the driver’s brake pedal (4) force.

5. The hill drive away assist as claimed in Claim 1 and working thereof wherein the hydraulic control module (2) and the electronic control module (1)holds the brake pressure (P2,P3) at the wheel end brakes (6) connected to the corresponding hydraulic circuit of the brake system, until travel of an accelerator pedal is beyond a set value; or set time elapsed since holding of a pipeline pressure (P2,P3) after the driver releases the brake pedal (4), provided brake is not applied again; or the vehicle is not in a consistent ascent or descent; or a gear position does not indicate a possible roll back or roll forward; the vehicle speed is greater than set speed; or a parking brake is engaged.

6. The hill drive away assist as claimed in Claim 1 and working thereof wherein the hydraulic control module (2) and the electronic control module (1)does not generate pressure in the corresponding hydraulic circuit of the brake fluid pipeline (7) but, aids in holding the pressure (P2,P3) generated by driver’s force of application of the brake pedal (4).

Dated this 21st day of March 2020

N. Surya Senthil – IN/PA-736
For JUS MAXIMA LAW OFFICES
To (Agent for Applicant)
The Controller of Patents
Patent Office in Chennai
, Description:TITLE
HILL DRIVE AWAY ASSIST

FIELD OF THE INVENTION

This invention relates to electro-mechanical engineering, specifically applicable toautomobiles withhydraulic brake system. This invention more specifically relates to a Hill Drive Away Assist in the hydraulic brake system of a vehicle, containing brake pedal,brake pressure source, brake fluid pipelines and wheel end brakes with wheel cylinders(drum brake) or calipers (disc brake) in a vehicle with or without ABS module.

BACKGROUND OF THE INVENTION

The common practice to hold the vehicle while on an ascent or descent is either by continuous application of force on the brake pedal or by application of external clamping force on the drum brakes or disc brakes. However, when a need to drive away arises, the driver either releases the external clamping force while applying force on the brake pedal and then shifts to the accelerator pedal or directly shifts to the accelerator pedal from brake pedal. During such instances, an unintended roll back or roll forward of the vehicle is caused, which could affect the safety of this vehicle and the nearby vehicles.This unintended movement of the vehicle, is due to the release of brake pipeline pressure at the wheel endsor lack of clamping force applied externally on the wheel end brakes. This can be avoided by retaining the brake pipeline pressure, generated by the force applied on the brake pedal by the driver prior to the application of accelerator pedal.

With the foregoing in mind, there is a need to develop an electro-mechanical control unit to retain the mentioned pressure in the vehicle.

The primary purpose of the present invention is to offer an aid in the vehicle to prevent any unintended movement during drive away, by holding the brake pipeline pressure at wheel ends with the help of an electro-mechanical control unit (EMCU). This forms a part of the existing hydraulic brake system in the vehicle. The compact size and unique design of this system makes it easier to include the same in any existing hydraulic brake system.

Indian Patent Number :979/CHE/2010 is a prior art in this field which reveals a way to control undesirable vehicle movement under gravity forces. According to this art,
1. The control mechanism is a solenoid valve, which uses two signals, namely speed monitoring sensor and throttle body sensor to energize and de-energize respectively. These signals are obtained by addition of external sensors in the vehicle.
2. The control mechanism is energized as soon as the speed monitoring system senses a zero speed and the control system is de-energized as soon as the throttle body sensor senses acceleration input. This could pose to be a safety critical issue when the vehicle is in a gradient and the gear is in neutral, by causing the vehicle to roll back or roll forward if accelerator pedal is pressed by mistake.
3. The control mechanism retains the pressure between the solenoid and the wheel end; but does not allow increase of this retained pressure when the driver intends to apply further force on the brake pedal to increase the pipeline pressure while the solenoid is energized. This could pose to be a safety critical issue when the pressure held at the wheel ends is not sufficient to hold the vehicle.
4. The control mechanism retains pressure at the wheel ends with wheel cylinders only.
5. The control mechanism is energized even on flat roads, when undesirable vehicle movement under gravity does not occur, causing unwanted holding of brake pipeline pressure thereby causing wear and tear of brake system components.

The present invention overcomes the demerits of the prior art cited above, in addition to meeting the primary functional requirements of providing assist during drive-away on hill as described below.
1. The present invention uses multiple inputs to actuate and de-actuate the cartridge. These inputs maybe obtained through hardwire or through the vehicle communication network without addition of any external sensors, thus differentiating the present invention from the prior art; This also reduces the overall cost of the system.
2. The input signal taken from gear position, helps to detect if the vehicle is in neutral gear and does not actuate the cartridge since it is unsafe. Thus, avoiding any sudden or unexpected roll back or roll forward.
3. The present invention allows increase of brake pipeline pressure when the driver intends to apply additional force on the brake pedal, even when the cartridge is actuated. This situation may arise when the driver realises that the pressure retained is insufficient to hold the vehicle and hence applies further force on the brake pedal.
4. The present invention is applicable to vehicles with calipers (disc brake) or wheel cylinders (drum brake).
5. The presence of an inclination sensor helps the cartridge to actuate only while on an ascent or descent, thus, mitigating unwanted actuation on flat roads. This helps to increase the durability of the system and also reduce the wear and tear on other brake parts.

This invention eventually addresses the above and proves to be performance efficient, cost effective and eases the assembly. These and other objects of the invention will become more apparent in the course of the ensuing specification and claims when taken with the accompanying drawings.

The electro-mechanical control unit (EMCU) remains inert, allowing normal functioning of the brake system without any interruption, during scenarios other than mentioned in the description.

Further it will be apparent to those skilled in the art that the objects of this invention have been achieved by providing an aid in the vehicle with hydraulic brake system to prevent unintended roll back or roll forward during drive away on a consistent ascent or descent as described in the above prior art. Various changes may be made in and without departing from the concept of the invention. Additional features of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiment as a basis for designing and modifying other methods and structures for carrying out the same purpose of the present invention.Therefore, the scope of the invention is to be determined by the terminology of the following claims and the legal equivalents thereof.

OBJECTIVES OF THE INVENTION

This invention may be summarized, at least in part, with reference to its objects.

The foremost object of the present invention is to present a hill drive away assist in the vehicle with hydraulic brake system to prevent unintended roll back or roll forward during drive away on a consistent ascent or descent.

Another object of the present invention is to provide a hill drive away assist system that can be connected to the existing hydraulic brake system.

Another object of the present invention is to provide a hill drive away assist as can be connected to the existing hydraulic brake system in vehicles having front-rear brake system split or diagonal brake system split, without any changes to the system to prevent unintended roll back or roll forward while on a consistent ascent or descent.

A further object of the present invention is to provide an electro-mechanical hill drive away assistsystem which can be used as an integrated electro-mechanical system mounted together, or stand-alone electronic and mechanical systemsmounted apart, still providing the intended function.

Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following, or may be learnt by practice of the invention.

SUMMARY OF THE INVENTION

The present invention embodies a hill drive away assist system that is an electro-mechanical control unit (EMCU).

The entire assembly comprises of the following parts:

A. Existing brake system with or without ABS consisting of

a. Brake Pedal (4)
b. Brake pressure source (5)
c. Brake fluid pipeline (7)
d. Wheel end brakes (Caliper or wheel cylinder) (6)
e. ABS (if equipped) (9)
B. Electronic Control Module Unit EMCU consisting of:
a. Electronic Control Module (ECM)(1)with or without in-built inclination sensor (10)
b. Hydraulic Control Module (HCM) (2) with a cartridge (8)

When the brake pedal is pressed, pressurized fluid flows from the brake pressure source through the brake fluid pipeline to the wheel end brakes to decelerate the vehicle or bring the vehicle to a halt. The brake pressure generated by the brake pressure source is retained at the wheel end brakeswhile the brake pedal is held.

DESCRIPTION OF THE DRAWINGS

The advantages and features of the present invention will be more readily apparent by persons skilled in the art when considered in reference to the following description and when taken in conjunction with the accompanying drawings listed below

Currently, the vehicles with hydraulic brake system are produced with or without ABS (9). The present invention caters to the requirements of vehicles with and without ABS (9).

Figure 1 is a cross sectional view of the layout & description of the hill drive away assist electro-mechanical control unit of the present invention.

Figure 2A is a cross sectional view of the brake pressure (P1,P2)in the input port and output port of the hydraulic control module (HCM) (2), of the present invention, before application of brake pedal (4) in a vehicle without ABS.

Figure 2B is a cross sectional view of the brake pressure(P1,P2) in the input port and output port of the hydraulic control module (HCM) (2), of the present invention, before application of brake pedal (4) in a vehicle with ABS (9).

Figure 3A is a cross sectional view of the brake pressure(P1,P2) in the input port and output port of the hydraulic control module (HCM) (2), of the present invention, during activation of cartridge (8) in HCM (2) during brake applied condition, in a vehicle without ABS.

Figure 3B is a cross sectional view of the brake pressure (P1,P2)in the input port and output port of the hydraulic control module (HCM) (2), of the present invention, during activation of cartridge (8) in HCM (2) during brake applied condition, in a vehicle with ABS (9).

Figure 4A is a cross sectional view of the brake pressure(P1,P2) in the input port and output port of the hydraulic control module (HCM) (2), of the present invention, during activation of cartridge (8) in HCM (2) after release of brake pedal (4), in a vehicle without ABS.

Figure 4B is a cross sectional view of the brake pressure (P1,P2)in the input port and output port of the hydraulic control module (HCM) (2), of the present invention, during activation of cartridge (8) in HCM (2) after release of brake pedal (4), in a vehicle with ABS (9).

Figure 5A is a cross sectional view of the brake pressure(P1,P2) in the input port and output port of the hydraulic control module (HCM) (2), of the present invention, when a vehiclewithout ABS module, is not on an ascent or descent, or when brake is applied at greater speeds or when the gear position does not cause a roll back or roll forward.

Figure 5B is a cross sectional view of the brake pressure(P1,P2) in the input port and output port of the hydraulic control module (HCM) (2), of the present invention, when a vehicle, with ABS module, is not on an ascent or descent, or when brake is applied at greater speeds or when the gear position does not cause a roll back or roll forward.

DETAILED DESCRIPTION

The following description is presented to enable any person skilled in the art to make and use the invention,and is provided in the context of particular applications of the invention and their requirements. The present invention can be configured as follows:

The present invention is a hill drive away assist system to prevent a vehicle from unintended rolling back or rolling forward during drive away while on an ascent or descent respectively.

Construction

According to a preferred embodiment of the present invention, as depicted in Figure 1, the entire assembly of the present invention hill drive away assist comprises of the following parts:

1. Electronic-Control Module (ECM) (1)with or without in-built inclination sensor (10); and
2. Hydraulic Control Module(HCM) (2)with a cartridge (8).

The existing brake system with or without ABS consisting of

f. Brake Pedal (4)
g. Brake pressure source (5)
h. Brake fluid pipeline (7)
i. Wheel end brakes (Caliper or wheel cylinder) (6)
j. ABS (if equipped) (9)

According to a preferred embodiment of the present invention, the electronic control module (ECM) (1), the brain of the system, functions based on the inputsignals given through hardwire or transmitted in the vehicle communication network (3) such as:
• the status of position of brake pedal (4) of the vehicle to detect whether the brake is applied or released;
• the travel of the accelerator pedal of the vehicle to detect when the driver intends to move;
• the gear position of the vehicle to detect the current gear status;
• the vehicle speed signal to determine the speed of the vehicle;
• the wheel speed signal to determine the rolling condition of the wheels;
• the parking brake switch signal to determine the park brake engagement status;
• Inclination sensor (10) to detect if the vehicle is on an ascent or on a descent.

Based on the above-mentioned inputs received through hardwire or through signals transmitted through the vehicle communication network (3), the electronic control module (ECM) (1) provides signal for actuating or de-actuating the cartridge (8).

The hydraulic control module (HCM) (2) comprises of a cartridge (8) which is activated or deactivated based on the control signal from electronic control module (ECM) (1).

The HCM (2) can be connected to the existing hydraulic brake system of a vehicle with its connections as described below.

EMCU assembly in vehicle without ABS Module

According to a preferred embodiment of the present invention, as depicted in Figure 5A,in a vehicle without ABS, the hydraulic control module (HCM) (2) is positioned, in any one of the hydraulic circuits of the brake system, between the brake pressure source (5) and wheel end brakes (6) connected by brake fluid pipeline (7).

EMCU assembly in vehicle with ABS Module

According to a preferred embodiment of the present invention, as depicted in Figure 5B, in a vehicle with ABS (9), the hydraulic control module (HCM) is positioned, in any one of the hydraulic circuits of the brake system, between the brake pressure source (5) and the corresponding input circuit of the ABS module (9) connected by brake fluid pipeline (7).

System behavior on flat road surfaces

According to a preferred embodiment of the present invention, as described in Figure 5A and 5B, while on a flat road, with no ascent or descent, the electro-mechanical control unit (EMCU) (1 and 2) does not interfere with the braking process. When the driver applies force on the brake pedal (4), pressure is developed in the brake fluid pipeline (7)and wheel end brakes (6) due to flow of pressurized fluid from brake pressure source (5). The brake fluid pressure applied (P2,P3) in the wheel end brakes (6) results in braking of the vehicle. The pressurized brake fluid (P1) passes through the hydraulic control module (HCM) (2) which allows free flow of fluid and does not interrupt the flow. The electro-mechanical control unit (EMCU) (1 and 2) remains inert when on flat roads to aid smooth motion of vehicle without any disturbance or unwanted holding of brake pipeline pressure.

System behavior on an ascent or descent

According to a preferred embodiment of the present invention, while on an ascent or descent, the electro-mechanical control unit (EMCU)(1 and 2) holds the brake pressure at the wheel-ends (6), for a set amount of time after release of the brake pedal (4), only if the following conditions are satisfied:
• The speed of the vehicle is less than set speed;
• The gear position signal indicates a possible rollback or roll forward.
• External force, other than brake pipeline pressure (P2,P3), is not applied at the wheel ends;
Even if one of the above-mentioned conditions is not met with, the system remains inert.

System behavior before brake pedal application

According to a preferred embodiment of the present invention, as depicted in Figure 2A and 2B, if the brake pedal (4) is not applied, and if no pressure is developed in the brake fluid pipeline (7), the system remains inert and does not interfere with system functions.

System behavior during actuated condition and increase in driver’s pedal effort

The EMCU (1 and 2) actuates the cartridge (8) and holds the pipeline pressure (P2,P3) during the conditions stated above.

According to a preferred embodiment of the present invention, as described in Fig 5A and 5B, while the hydraulic control module (HCM) (2) is in activated condition, if any additional pressure is applied to the input of the module due to additional force applied on the brake pedal (4), the pressure(P2,P3) between thehydraulic control module (HCM) (2) and wheel end (6) becomes equal to the pressure between brake pressure source (5) and EMCU(1 and 2).

System behavior after release of brake

If the vehicle is in the following scenario with:
• Vehicle positioned in an ascent or descent
• Vehicle speed less than set speed
• Gear position signal as mentioned prior
• No external clamping force applied on the wheel ends (6)
then, the hydraulic control module (HCM) (2) remains actuated for set amount of time, thereby holding the pressure at wheel ends (P2,P3).

According to a preferred embodiment of the present invention, as described in Fig 4A and 4B, while the hydraulic control module (HCM) (2) is actuated, even after release of the brake pedal (4) and releasing pressure in the inlet port of the hydraulic control module (HCM) (2) (P1), the pressure is not released in the outlet port of the hydraulic control module (HCM) (2) (P2), till set time.

While there has been shown and described what is considered to be preferred embodiments of the invention, it will, of course, be understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is therefore intended that the invention be not limited to the exact forms described and illustrated, but should be constructed to cover all modifications that may fall within the scope of the appended claims.

It will be apparent to those skilled in the art that the objects of this invention have been achieved by providing the above invention. However various changes may be made in the structure of the invention without departing from the concept of the invention. Therefore, the scope of the invention is to be determined by the terminology of the following claims and the legal equivalents thereof.

Dated this 21st day of March 2020
N. Surya Senthil – IN/PA-736
For JUS MAXIMA LAW OFFICES
(Agent for Applicant)
To:
The Controller of Patents
Patent Office in Chennai