Title of Invention	NON-SOLENOID HYDRAULIC CONTROL UNIT FOR ANTI-LOCK BRAKE SYSTEM OF HYDRAULICALLY OPERATED BRAKES OF AN AUTOMOBILE
Abstract	A novel hydraulic control unit for anti-lock braking system of an automobile, without a conventional solenoid, is an electronically operated, modulation cylinder (7) consisting of a plunger (1) attached to the shaft (12) of a motor (2) through a sieeve (11), which keeps the port (3) normally open for the fluid from inlet port (4) to enter into the outlet port (5) during normal braking condition. By pulling the plunger (1) back, entry of fluid from the inlet port (4) to outlet port (5) is cut off during the Isolation mode; during the dump mode, the plunger (1) is further pulled back to dump fluid from the outlet port (5) into the modulation cylinder {7). The modulation cycle is repeated during the anti-lock cycle as and when necessary which is substantially as herein described with reference to and as illustrated in the Fig.l.

Title of Invention

NON-SOLENOID HYDRAULIC CONTROL UNIT FOR ANTI-LOCK BRAKE SYSTEM OF HYDRAULICALLY OPERATED BRAKES OF AN AUTOMOBILE

Abstract

A novel hydraulic control unit for anti-lock braking system of an automobile, without a conventional solenoid, is an electronically operated, modulation cylinder (7) consisting of a plunger (1) attached to the shaft (12) of a motor (2) through a sieeve (11), which keeps the port (3) normally open for the fluid from inlet port (4) to enter into the outlet port (5) during normal braking condition. By pulling the plunger (1) back, entry of fluid from the inlet port (4) to outlet port (5) is cut off during the Isolation mode; during the dump mode, the plunger (1) is further pulled back to dump fluid from the outlet port (5) into the modulation cylinder {7). The modulation cycle is repeated during the anti-lock cycle as and when necessary which is substantially as herein described with reference to and as illustrated in the Fig.l.

Full Text	The invention is related to a Non-solenoid based hydraulic control unit for Anti-lock brake system of hydraulically operated brakes of an automobile, in which a plunger is moved by a motor to close a port to isolate and drain off the brake fluid in a controlled fashion from the hydraulic brake circuit during a v\fief skid. During braking, when the brake force generated at the ground due to brake hydraulic pressure exceeds the ground reaction force, the wheel tends to lock and thus skidding takes place. Any skidding wheel will have resistance offered to movement equal in all directions, unlike the rolling wheel, which will have lowest resistance in the direction of motion. So the vehicle in skid can move in any director irKtependent of the driver's will, depending upon \he resultant force acting on the vehicle. Normally tie brake force developed at the tire to road contact path is directly proportional to the hydraulic brake pressure, which in learn depends on tie pedal effort exerted by the driver. But this is not so at the wheel skid condition. Rapid wheel decelerations are obtained at condition when brake torque generated due to pedal force, in the wheel exceeds the torque on the wheel due to ground friction at the wheel. To change the brake force dynamically, depending upon the tire to naiad adhesion coefficient one has to avoid skid condition, which is achieved by isolation and modulation of the brake pressure accordingly. Modulation of the brake pressure depends on the driver's response and skill, which are entirely individualistic and cannot be dependable during skidding. To dynamically control the brake force at the wheels, a fast responding intelligent brake control system is needed. The said device is the hydraulic control unit of tie electronically controlled fast responding Anti-lock brake system. The object of the invented device is to isolate the outlet port (5) from the inlet port (4) thereby preventing further increasing in pressure and then dumping fluid from the outlet port (5) into the modulation cylinder (7), to reduce the brake pressure during the Anti-lock brake cycle. The Non-solenoid Hydraulic Control Unit, according to the invention is an electronically operated modulation cylinder, in which a plunger (1), ball (6) and spring (9) arrangement keep the port (3) normally open for the fluid from inlet port (4) to enter into the outlet port (5) during normal braking condition. The spring (9) is initially under load. During the isolation phase of an Anti-lock brake control cycle, the plunger (1) is pulled back by the motor (2) through the sleeve (10), which is connected to the shaft (U) of the motor, such that the port (3) gets closed and the outlet port (5) is isolated from the inlet port (4). Now the spring (9) gets relaxed. For further pressure modulation during the dump phase of the anti lock braking cycle, the plunger (1) is moved further backward based on the anti lock brake cycle parameters and dumps the fluid into a modulation cylinder (7). If required, the plunger (1) can be moved forward. The fluid collected in the modulation cylinder (7) can be pumped back into the outlet port (5) and thus cause an increase in the pressure during that brake application itself. Thus an active system is achieved. The maximum pressure that can be achieved in the outlet port (5) wilt be equal to the initially applied pressure. After the brake application is over, the plunger (1) is moved back to its original position. The spring (9) gets loaded again thus keeping the ball (6) in its original position and normal hydraulic line is resumed. By using this design, isolation and dump solenoids and non-return valve of the conventional anti lock braking system are eliminated and the system is made active. Accordingly the invention provides for An hydraulic control unit, for anti-lock braking system of an automobile, comprising of an electronically operated modulation cylinder, a plunger attached to a sleeve connected to the shaft of a motor and a spring wherein the said modulation cylinder is controlled by an electronic control unit which provides signal to the stepper motor depending upon the tire to road adhesion wherein when the tire to road adhesion exceeds the predetermined range the plunger retracts allowing the brake fluid pressure to be modulated. The invention will now be described, by way of example, with reference to the accompanying drawing in which:- The hydraulic control unit construction and arrangement of internal parts are shown In Fig-1. This unit is a part and parcel of the anti lock brake system. It consists of a plunger (1) attached sleeve (10) connected to the shaft (11) of a motor (2) which keeps the port (3) normally open for the fluid from inlet port (4) to enter into the outlet port (5) during normal braking condition. A "0" ring (8) is provided to prevent leakage of fluid. During the isolation phase the plunger (1) is pulled back by the shaft (12) through the sleeve (11), such that the bal) (6) closes the port (3) and the outlet port (5) is isolated from the inlet port (4). The spring (9) helps in retaining the ball (6) in its original position during the return stroke. For further pressure modulation during the dump phase of the anti lock brake control cycle, plunger (1) is moved further backward and fluid get s dumped into the modulation cylinder (7). A hydraulic control unit, an electronically operated calculation cylinder, for anti-lock brake system of hydraulically operated brakes of an automobile, comprising of a plunger, attached to a sleeve connected to tie shaft of a motor, a spring, inlet port and outlet port. During the isolation phase, the plunger is pulled back by the shaft through tie sleeve such that the ball closes the port and th& outlet port is isolated from the inlet port and during the dump mode, the plunger is further plied back to dump fluid from the outlet port into the modulation cylinder. A "0" ring is provided to prevent leakage of fluid. Further while repeating tie modulation cycle, the plunger moves forward and pressure is increased to utilize tie brake effectively and keep the stopping distance minimum. After the brake application is over, the plunger moves back to its original position and normal hydraulic line is resumed by opening the port and again connects the inlet port and the outlet port. We Claim: CI) An hydraulic control unit, for anti-lock braking system of an automobile, comprising of an electronically operated modulation cylinder, a plunger attached to a sleeve connected to the shaft of a stepper motor and a spring, wherein the said modulation cylinder is controlled by an electronic control unit which provides signal to the stepper motor depending upon the tire to road adhesion wherein when the tire to road adhesion exceeds the predetermined range the plunger retracts allowing the brake fluid pressure to be modulated. (2) An hydraulic control unit as claimed in claim-l, wherein, an inlet port and outlet port are connected to the modulation cylinder such that the said plunger operates to connect and disconnect the inlet and outlet port to isolate and dump fluid into the modulation cylinder in conjunction with the service brake utilizing the available brake efficiency. (3) A hydraulic control unit for anti lock braking system of an automobile substantially as herein described and illustrated with reference to the accompanying drawing.

Full Text

The invention is related to a Non-solenoid based hydraulic control unit for Anti-lock brake system of hydraulically operated brakes of an automobile, in which a plunger is moved by a motor to close a port to isolate and drain off the brake fluid in a controlled fashion from the hydraulic brake circuit during a v\fief skid.
During braking, when the brake force generated at the ground due to brake hydraulic pressure exceeds the ground reaction force, the wheel tends to lock and thus skidding takes place. Any skidding wheel will have resistance offered to movement equal in all directions, unlike the rolling wheel, which will have lowest resistance in the direction of motion. So the vehicle in skid can move in any director irKtependent of the driver's will, depending upon \he resultant force acting on the vehicle.
Normally tie brake force developed at the tire to road contact path is directly proportional to the hydraulic brake pressure, which in learn depends on tie pedal effort exerted by the driver. But this is not so at the wheel skid condition. Rapid wheel decelerations are obtained at condition when brake torque generated due to pedal force, in the wheel exceeds the torque on the wheel due to ground friction at the wheel. To change the brake force dynamically, depending upon the tire to naiad adhesion coefficient one has to avoid skid condition, which is achieved by isolation and modulation of the brake pressure accordingly.

Modulation of the brake pressure depends on the driver's response and skill, which are entirely individualistic and cannot be dependable during skidding. To dynamically control the brake force at the wheels, a fast responding intelligent brake control system is needed. The said device is the hydraulic control unit of tie electronically controlled fast responding Anti-lock brake system.
The object of the invented device is to isolate the outlet port (5) from the inlet port (4) thereby preventing further increasing in pressure and then dumping fluid from the outlet port (5) into the modulation cylinder (7), to reduce the brake pressure during the Anti-lock brake cycle.
The Non-solenoid Hydraulic Control Unit, according to the invention is an electronically operated modulation cylinder, in which a plunger (1), ball (6) and spring (9) arrangement keep the port (3) normally open for the fluid from inlet port (4) to enter into the outlet port (5) during normal braking condition. The spring (9) is initially under load. During the isolation phase of an Anti-lock brake control cycle, the plunger (1) is pulled back by the motor (2) through the sleeve (10), which is connected to the shaft (U) of the motor, such that the port (3) gets closed and the outlet port (5) is isolated from the inlet port (4). Now the spring (9) gets

relaxed. For further pressure modulation during the dump phase of the anti lock braking cycle, the plunger (1) is moved further backward based on the anti lock brake cycle parameters and dumps the fluid into a modulation cylinder (7). If required, the plunger (1) can be moved forward. The fluid collected in the modulation cylinder (7) can be pumped back into the outlet port (5) and thus cause an increase in the pressure during that brake application itself. Thus an active system is achieved. The maximum pressure that can be achieved in the outlet port (5) wilt be equal to the initially applied pressure. After the brake application is over, the plunger (1) is moved back to its original position. The spring (9) gets loaded again thus keeping the ball (6) in its original position and normal hydraulic line is resumed. By using this design, isolation and dump solenoids and non-return valve of the conventional anti lock braking system are eliminated and the system is made active.
Accordingly the invention provides for An hydraulic control unit, for anti-lock braking system of an automobile, comprising of an electronically operated modulation cylinder, a plunger attached to a sleeve connected to the shaft of a motor and a spring wherein the said modulation cylinder is controlled by an electronic control unit which provides signal to the stepper motor depending upon the tire to road adhesion wherein when the tire to road adhesion exceeds the predetermined range the plunger retracts allowing the brake fluid pressure to be modulated.

The invention will now be described, by way of example, with reference to the accompanying drawing in which:-
The hydraulic control unit construction and arrangement of internal parts are shown In Fig-1. This unit is a part and parcel of the anti lock brake system.
It consists of a plunger (1) attached sleeve (10) connected to the shaft (11) of a motor (2) which keeps the port (3) normally open for the fluid from inlet port (4) to enter into the outlet port (5) during normal braking condition. A "0" ring (8) is provided to prevent leakage of fluid.
During the isolation phase the plunger (1) is pulled back by the shaft (12) through the sleeve (11), such that the bal) (6) closes the port (3) and the outlet port (5) is isolated from the inlet port (4). The spring (9) helps in retaining the ball (6) in its original position during the return stroke.
For further pressure modulation during the dump phase of the anti lock brake control cycle, plunger (1) is moved further backward and fluid get s dumped into the modulation cylinder (7).

A hydraulic control unit, an electronically operated calculation cylinder, for anti-lock brake system of hydraulically operated brakes of an automobile, comprising of a plunger, attached to a sleeve connected to tie shaft of a motor, a spring, inlet port and outlet port. During the isolation phase, the plunger is pulled back by the shaft through tie sleeve such that the ball closes the port and th& outlet port is isolated from the inlet port and during the dump mode, the plunger is further plied back to dump fluid from the outlet port into the modulation cylinder. A "0" ring is provided to prevent leakage of fluid.
Further while repeating tie modulation cycle, the plunger moves forward and pressure is increased to utilize tie brake effectively and keep the stopping distance minimum. After the brake application is over, the plunger moves back to its original position and normal hydraulic line is resumed by opening the port and again connects the inlet port and the outlet port.

We Claim:
CI) An hydraulic control unit, for anti-lock braking system of an automobile, comprising of an electronically operated modulation cylinder, a plunger attached to a sleeve connected to the shaft of a stepper motor and a spring, wherein the said modulation cylinder is controlled by an electronic control unit which provides signal to the stepper motor depending upon the tire to road adhesion wherein when the tire to road adhesion exceeds the predetermined range the plunger retracts allowing the brake fluid pressure to be modulated.
(2) An hydraulic control unit as claimed in claim-l, wherein, an inlet port and outlet port are connected to the modulation cylinder such that the said plunger operates to connect and disconnect the inlet and outlet port to isolate and dump fluid into the modulation cylinder in conjunction with the service brake utilizing the available brake efficiency.
(3) A hydraulic control unit for anti lock braking system of an automobile substantially as herein described and illustrated with reference to the accompanying drawing.

Documents:

0785-mas-2001 abstract.pdf

0785-mas-2001 claims.pdf

0785-mas-2001 correspondence-others.pdf

0785-mas-2001 correspondence-po.pdf

0785-mas-2001 description (complete).pdf

0785-mas-2001 drawings.pdf

0785-mas-2001 form-1.pdf

0785-mas-2001 form-19.pdf

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Patent Number

198878

Indian Patent Application Number

785/MAS/2001

PG Journal Number

08/2007

Publication Date

23-Feb-2007

Grant Date

22-Feb-2006

Date of Filing

21-Sep-2001

Name of Patentee

M/S. BRAKES INDIA LIMITED

Applicant Address

PADI, CHENNAI - 600 050 TAMIL NADU

Inventors:

#	Inventor's Name	Inventor's Address
1	H. RAMASUBRAMANIAN	DIVISIONAL MANAGER (ADVANCED ENGG.) BRAKES INDIA LIMITED PADI, CHENNAI 600 050 TAMIL NADU
2	MS. SUDHA RAMANI	SENIOR ENGINEER (ADVANCED ENGG.) BRAKES INDIA LIMITED PADI, CHENNAI - 600 050 TAMIL NADU

PCT International Classification Number

B60T8/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA