JP2015085835A - Braking device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a braking device that always secure high brake responsiveness without reference to stepping-in strength of a last braking operation.SOLUTION: A main control valve 22 is provided at a main oil passage first part 21a connected to a master cylinder, and the pressure oil of the master cylinder 3 reaches brakes 4, 5 though holding solenoids 23, 24 and pressure reduction solenoid valves 25, 26. An oil pressure pump 46 and a reservoir tank 43 are provided at a sub oil passage 42 branching off from the main oil passage first part 21a. The oil pressure pump 46 accumulates pressure in the oil in the reservoir tank 43 after a braking operation, and the oil pressure pump 46 sucks the oil in the reservoir tank 43 with a main control valve 22 closed in the beginning of a next braking operation so as to pressurize cylinders 11, 19 of brakes 4, 5.

Description

  The present invention relates to a brake device for a vehicle (automobile).

  The brake of the vehicle is configured such that a master cylinder is operated by a brake pedal. In the case of a disc brake, the vehicle is decelerated or stopped by sandwiching a disc rotor fixed to the axle with a brake pad. The brake pad is advanced by hydraulic pressure from the master cylinder.

  The brake device with ABS (anti-lock brake system) function includes a holding solenoid valve and a pressure reducing solenoid valve corresponding to the brakes of each wheel, and the pressure is reduced while the return of oil is prevented by the holding solenoid valve. By driving the hydraulic pump while opening and closing the solenoid valve, the brake can be turned on and off in small increments, and a reservoir tank is installed in the circuit to enable decompression and pressurization in a closed circuit. I have.

  Now, brakes are provided at each wheel, and each brake and master cylinder are connected by hydraulic passages such as pipes and hoses, so there is a slight delay in the pressure of the master cylinder being transmitted to each brake. For this reason, there is a delay from when the brake pedal is depressed until the brake actually starts to work.

  Therefore, a proposal has been made to increase the response of the brake operation to the depression of the brake pedal. As an example, in Patent Document 1, when the brake is turned off after the brake operation, the hydraulic pressure is the same as the hydraulic pressure at the time of the previous brake operation. It is described that the oil is accumulated in the accumulator, and the oil is sent from the accumulator to the brake cylinder when the brake is operated next, thereby assisting in the initial stage of the brake operation.

JP 2000-88612 A

  In Patent Document 1, the oil is accumulated in the accumulator at the same hydraulic pressure as that at the time of the previous brake operation. The accumulator is always filled and filled with the reduced oil on the basis of the state where the accumulator is full. This is considered to have improved the response of the brake cylinder, but with this method, errors accumulate when used for a certain amount of time, and the amount of oil stored in the accumulator in the standby state varies greatly. In such a case, the assist force for the brake cylinder may vary, and the braking effectiveness and responsiveness may become unstable.

  The present invention has been made to improve the current situation.

  The brake device of the present invention includes a master cylinder operated by a brake pedal, and a brake cylinder operated by oil sent from the master cylinder through a main oil passage, and the main oil passage has oil in the main oil passage. A main control valve that cuts off the flow, a sub oil passage is branched from a portion of the main oil passage downstream of the main control valve, a reservoir tank is provided at the end of the sub oil passage, and The sub oil passage has a basic configuration in which a hydraulic pump capable of storing oil in the reservoir tank is provided.

  Then, when the brake pedal is released, oil is accumulated in the reservoir tank by the hydraulic pump, and at the initial stage of the next brake operation, the hydraulic pump is driven with the main control valve closed once, whereby the oil in the reservoir tank is The oil pressure for the brake cylinder is controlled to be increased through

  In the present invention, the oil is stored in the reservoir tank by the hydraulic pump after the brake pedal is operated, so that after the brake pedal is operated, the reservoir tank is always full and can be put on standby for the next braking. Then, with the main control valve closed at the initial stage of the brake pedal operation, the hydraulic oil can be applied to the oil in the reservoir tank by the hydraulic pump, and then the brake valve is opened by opening the main control valve. Pressure oil generated by depressing the pedal can be applied to the brake cylinder.

  In this way, it is possible to improve the responsiveness of the brake operation by applying a positive pressure to the brake cylinder in the initial operation of the brake pedal, but in the present invention, regardless of the depression strength of the brake pedal 1 during the previous braking, Since the reservoir tank is fully held by the hydraulic pump after braking, the responsiveness of the brake device can be made constant and the brake feeling can be improved.

  Moreover, although the brake device with the ABS function includes a hydraulic pump, the present invention can be used as it is in the existing device, so that it is highly versatile and advantageous in terms of cost.

It is a circuit diagram of an embodiment. FIG. 2 is an enlarged view of half of FIG. 1.

(1). Outline of Structure Next, an embodiment of the present invention will be described with reference to the drawings. The brake device includes a brake pedal 1 provided in a driver's seat, a master cylinder 3 that is operated by the brake pedal 1 via a booster 2, and a pair of brakes that operate with pressure oil from the master cylinder 3 to decelerate or stop the vehicle. A disc brake 4 and a drum brake 5 are provided, and an actuator (control circuit) 6 having an ABS function is interposed between the master cylinder 3 and the disc brake 4 and the drum brake 5.

  The brake pedal 1 is rotatably connected to the vehicle body, and it can be detected by the brake sensor 7 whether or not the driver has stepped on the brake pedal 1. The brake sensor 7 may be an ON / OFF type limit switch, or may be a potentiometer that can detect the amount of depression (or the depression speed). In the case of ON / OFF type, it will turn ON after play is over. The master cylinder 3 is provided with a reservoir 8.

  The disc brake 2 includes a disc rotor 9 fixed to an axle and a caliper body 10 that partially surrounds the disc rotor 9. A cylinder 11 that opens toward the disc rotor 9 is provided in the caliper body 10. 11, a piston 12 is slidably disposed. A brake pad 14 is attached to the tip of the piston 14 via an inner plate 13, while an outer pad 16 fixed via an outer plate 15 is disposed on the jaw portion of the caliper body 10. The disk rotor 9 is pinched by 14 and 16.

  On the other hand, the drum brake 5 includes a drum 17 fixed to the axle and two semicircular brake shoes 18 disposed therein. The two brake shoes 18 are urged by springs (not shown) in a direction away from the inner surface of the drum 17, and the two brake shoes 18 are pushed and spread by the cylinder 19 against the springs. Pressed against the inner surface.

  When the disc brake 4 and the drum brake 5 are used together as in the present embodiment, the disc brake 4 is often provided on the front wheel and the drum brake 5 is often provided on the rear wheel. Needless to say, only the disc brake 4 or the drum brake 5 may be used.

  From the master cylinder 3, two main oil passages 21 for a set of one disc brake 4 and one drum brake 5 are branched, and one main oil passage 21 is sequentially provided from the upstream side. A main control valve 22, a first and second pair of holding solenoid valves 23 and 24, and a first and second pair of pressure reducing solenoid valves 25 and 26 are interposed.

(2) Details of the actuator The main control valve 22 has one inlet port 27 and first and second outlet ports 28 and 29, and the ports 27, 28 and 29 communicate with each other internally. doing. The first outlet holding port 28 has a needle-type first valve body 31 that is operated by a solenoid 30, and the first valve body 31 is biased by a spring in a reverse flow allowable direction. The valve element 31 energizing the solenoid 30 moves forward to prevent forward flow and reverse flow. The second outlet port 29 has a second check valve (check valve) 32 that allows forward flow and prevents backflow.

  Therefore, when the main control valve 22 is in the open state (non-energized state), the oil can flow forward from the first outlet 28 and the second outlet 29 and back flow from the first outlet 28, and the main control valve 22 is closed (energized). In the state), the oil can flow out from the second outlet 28, but neither of the outlets 28, 29 can flow back.

  The first and second holding solenoid valves 23 and 24 have the same structure as the main control valve 22, but the relationship between the inlet and the outlet is different, and the first and second inlet ports 33 and 34 are different from each other. And one outlet port 35. Since the movement is only reverse to that of the main control valve 22, the description is omitted.

  The pressure reducing solenoid valves 25 and 26 have one inlet port 38 and one outlet port 39. The inlet port 38 is provided with a valve body 40 biased by a spring to prevent backflow. The valve body 40 is retracted by energization of the solenoid 41. That is, when the decompression solenoid valves 25 and 26 are closed (non-energized state), the oil flows from the inlet port 38 to the outlet port 39, and in the opened state (energized state), the oil flows back from the outlet port 39 to the inlet port 38. . Accordingly, the pressurization and depressurization of the brakes 4 and 5 with respect to the cylinders 11 and 19 can be changed by turning the depressurization solenoid valves 25 and 26 on and off.

  A main oil passage first portion 21 a is connected to the inlet port 27 of the main control valve 22, and a main oil passage second portion 21 b is connected to the two outlets 28, 29 of the main control valve 22. And the main oil passage third portion 21c connected to the first and second inlet ports 33, 34 of the second holding solenoid valves 23, 24 and connected to the outlet port 35 of the holding solenoid valves 23, 24 is the disc brake 4 The cylinder 11 and the cylinder 19 of the disc brake 4 are connected.

  Further, the main oil passage third portion 21c and the inlet port 38 of the pressure reducing solenoid valves 25, 26 are connected by the main oil passage fourth portion 21d, and the outlet ports 39 of the two pressure reducing solenoid valves 25, 26 are connected to the main oil passage first. The five parts 21e are connected.

  The reason why two holding solenoid valves 23 and 24 and two pressure reducing solenoid valves 25 and 26 are provided in one system is to control the four brakes 4 and 5 independently.

  A sub oil passage 42 branches off from the main oil passage second portion 21 b, and a reservoir tank 43 is connected to the end of the sub oil passage 42. The reservoir tank 43 has a plunger 45 biased by a spring 44, and oil is stored in the reservoir tank 43 by applying a pressure against the spring 44. The accumulated oil is discharged by the spring 44.

  A hydraulic pump 46 and a check valve 47 are provided in the middle of the sub oil passage 42. The check valve 47 allows a reverse flow in the direction of the main control valve 22 and prevents a forward flow by moving the valve body against the spring. The spring of the check valve 47 is set stronger than the spring 44 of the reservoir tank 43. Therefore, unless the hydraulic pump 46 is driven, the oil in the reservoir tank 43 does not flow backward in the direction of the main control valve 22.

  A portion of the sub oil passage 42 on the downstream side of the hydraulic pump 46 and the main oil passage fourth portion 21 e are connected by a sub passage 48. The main passage first portion 21a and the reservoir tank 43 are connected by a relief passage 49. The relief passage 49 is provided with a check valve 50 that allows only oil relief. The check valve 50 is a kind of safety valve, and its spring is set stronger than the spring 44 of the reservoir tank 43. A pressure sensor 51 is also provided in the relief passage 49.

(3). Description of Action In the above description, when the ABS function is not exhibited, the holding solenoid valves 23 and 24 are in a non-energized state, and the pressure oil in the master cylinder 3 is transmitted to the brakes 4 and 5 as they are. It is done. On the other hand, when the ABS function is exhibited, the holding solenoid valves 23 and 24 are closed, and the pressure reducing solenoid valves 25 and 26 are opened and closed while driving the hydraulic pump 46 in the direction in which oil flows backward.

  When the depression of the brake pedal 1 is released and the brake sensor 7 is turned off, the main control valve 22 is opened, the holding solenoid valves 23 and 24 are closed, and the hydraulic pump 46 is driven. Then, the oil in the hydraulic line is subjected to the action of being discharged toward the main control valve 22, but the oil cannot flow back through the main control valve 22 because the main control valve 22 is closed. The oil is sucked toward the hydraulic pump 46, loses the escape place, and accumulates in the reservoir tank 43 (see the black arrow in FIG. 2 and the one-dot chain line of the reservoir tank 43). Since the hydraulic pump 46 only sucks oil in the pipeline, it can be driven in a short time.

  Next, when the driver depresses the brake pedal 1, the main sensor valve 22 is closed (in an energized state) and the pressure-reducing solenoid valves 25 and 26 are opened (in a non-energized state) by turning on the brake sensor 7. 46 drives oil. In this case, the holding solenoid valves 23 and 24 may be closed or may remain open.

  Then, the sub oil passage 42 becomes negative pressure, so that the oil in the reservoir tank 43 tends to be sucked up. However, since the oil cannot flow backward from the main control valve 22, The main oil passage fourth portion 21e and the main oil passage third portion 21c are pressurized in an attempt to flow into the portion 21d and the main oil passage third portion 21c. As a result, pressure oil is actuated on the cylinders 11 and 19 of the brakes 4 and 5, and the brakes 4 and 5 start to be effective, or a standby state in which the brakes 4 and 5 can be immediately effective is set.

  The operation of the main control valve 22 and the hydraulic pump 46 is executed for a short time only at the initial stage of depression of the brake pedal 1, and when the predetermined time has elapsed (or when the depression amount of the brake pedal 1 reaches a predetermined amount), the main control valve 22 is turned OFF and the hydraulic pump 46 is turned OFF to return to the reference state. Then, the pressure oil from the master cylinder 3 acts on the system, and a pressing force having a strength corresponding to the depression strength of the brake pedal 1 acts on the cylinders 11 and 19.

  At this time, since the pressure oil acts downstream of the main control valve 22 in the circuit, the pressure by the master cylinder 3 is immediately transmitted to the cylinders 11 and 19 without causing a time lag. Therefore, the brake feeling can be improved by maintaining the responsiveness of the brakes 4 and 5 by the brake pedal 1 at a high level.

  In the above embodiment, the oil is stored in the reservoir tank 43 in the hydraulic line by the suction action of the hydraulic pump 46. However, as a means for storing the oil in the reservoir tank 43 when the brake is released, the hydraulic pump 46 can be rotated forward and backward. In this case, it is also possible to suck oil from the main control valve 22 side and feed it to the reservoir tank 43 by the hydraulic pump 46 when the brake is released (in this case, the check valve 47 is It is necessary to configure the same solenoid type as the pressure reducing solenoid valve.)

  Moreover, although said embodiment was applied to the brake device with an ABS function, this invention is applicable also to the brake device without an ABS function. However, when applied to a system with an ABS function, existing members can be used as they are, which is preferable in terms of cost.

  The present invention is actually applicable to a vehicle brake device. Therefore, it can be used industrially.

1 Brake Pedal 3 Master Cylinder 4 Disc Brake 5 Drum Brake 6 Actuator 7 Brake Sensor 9 Disc Rotor 11 Disc Brake Cylinder 12 Disc Brake Piston 14, 16 Pad 17 Drum 18 Brake Shoe 19 Drum Brake Cylinder 21 Main Oil Path 22 Main Control valve 22, 23 Holding solenoid valve 25, 26 Depressurization solenoid valve 42 Sub oil passage 43 Reservoir tank 46 Hydraulic pump 47 Sub control valve

Claims (1)

A master cylinder operated by a brake pedal, and a brake cylinder operated by oil sent from the master cylinder through a main oil passage;
The main oil passage is provided with a main control valve that cuts off the flow of oil, and a sub oil passage is branched from a portion of the main oil passage downstream of the main control valve to reach the end of the sub oil passage. A reservoir tank is provided, and the sub oil passage is provided with a hydraulic pump capable of storing oil in the reservoir tank,
When the brake pedal is released, oil is stored in the reservoir tank by the hydraulic pump, and in the initial stage of the next brake operation, the hydraulic pump is driven with the main control valve closed once, so that the oil in the reservoir tank is Controlled to increase the oil pressure to the brake cylinder,
Brake device for vehicles.

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