JPH0537623U - Anti-lock brake device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an anti-lock brake device that prevents the occurrence of surges and the delay of the onset of normal braking, while not causing a decrease in brake durability and fuel consumption. [Constitution] When the hydraulic pressure on the master cylinder 10 side increases during braking, the normally open check valve 69 closes and the plunger 63 moves right against the spring 65. Only in the initial stage of the right movement of the plunger 63, the brake fluid in the spring chamber 64 is supplied to the wheel cylinder 20 through the throttle 67D, and is then directly supplied through the oblique cutout 63A. When the brake is released, the check valve 69 is opened and the brake fluid pressure in the wheel cylinder is reduced to the master cylinder pressure.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an antilock brake device.

[0002]

[Prior Art]

 Conventionally, as such an antilock brake device, the one described in JP-A-60-33158 is known.

[0003] In order to mitigate a surge or the like due to a sudden change in the wheel cylinder pressure during antilock control, this one has a fixed throttle provided in a pipe line for applying hydraulic pressure from the master cylinder to the wheel cylinder. Brake fluid is supplied to the wheel cylinders via a fixed throttle. However, in such a conventional anti-lock brake device, since a fixed throttle is provided in the pipe line that creates hydraulic pressure from the master cylinder to the wheel cylinders, it is possible to prevent surges and the like. On the other hand, this fixed throttle always has a throttle action even during normal braking, so the wheel cylinder pressure rises slowly, in other words, it takes a long time from when the brake pedal is pressed until the brake starts to work. There is.

Therefore, in order to solve such a problem, there is provided a plunger means with a check valve, which is moved in the pipeline by the generated pressure of the master cylinder so as to perform the throttling action only in the initial stage of the pressure increase. The applicant proposed the provided one (Japanese Patent Application No. 2-65415).

[0005]

[Problems to be solved by the device]

 However, since the above-mentioned check valve is a type that opens when returning the brake fluid from the wheel cylinder to the master cylinder side, when the brake is released, residual pressure remains in the wheel cylinder due to the opening pressure of the check valve. However, as a result of the so-called drag phenomenon, the durability of the brakes may deteriorate and fuel consumption may deteriorate.

An object of the present invention is to solve the problems of the conventional device, prevent the occurrence of surges and the delay in the start of the normal brake operation, and at the same time, prevent the deterioration of brake durability and fuel consumption. To provide a lock brake device.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a passage that connects a master cylinder and a wheel cylinder of a brake device, and a switching control valve that controls switching of the wheel cylinder to a depressurizing, holding or boosting state during braking. And a plunger means provided in the passage, which moves by the generated pressure of the master cylinder and pressurizes the wheel cylinder with a throttling action only in the initial stage of pressure increase. It is characterized in that the plunger means is provided with a normally open check valve that opens the passage when the generated pressure of the master cylinder decreases.

[0008]

[Action]

 According to the present invention, during normal braking, when the hydraulic pressure on the master cylinder side becomes high, the normally open check valve closes and the plunger means moves, and the wheel cylinder is applied with a throttling action only at the initial stage. Is pressed. However, after the initial stage, the wheel cylinder is pressurized without the throttling action.

Further, when the anti-lock brake device is actuated and the switching control valve is switched to maintain the wheel cylinder in the depressurized and held state and then to reincrease the pressure, the wheel cylinder is re-pressurized only in the initial stage. Is pressurized.

When the brake is released, the normally open check valve provided in the plunger means opens, so that the brake fluid pressure in the wheel cylinder is reduced to the master cylinder pressure.

Therefore, the occurrence of surges and the delay in the onset of braking are reliably prevented, and residual pressure does not remain.

[0012]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a piping system diagram of an antilock brake device showing an embodiment of the present invention.

In the figure, reference numeral 10 denotes a master cylinder having first and second hydraulic pressure generating chambers, which is provided with a reservoir 11 for storing brake fluid, and which produces hydraulic pressure in accordance with the depression amount of a brake pedal 12. To do.

Reference numeral 20 denotes a wheel cylinder provided for each wheel 21, and hereinafter, the wheel cylinder of the right front wheel 21FR is referred to as 20FR, the wheel cylinder of the left front wheel 21FL is referred to as 20FL, and the wheel cylinder of the rear wheel 21R is referred to as 20R. Each of the front and rear wheels is provided with a wheel speed sensor (not shown) that detects the rotation speed of each wheel.

The first hydraulic pressure generating chamber of the master cylinder 10 is connected to the wheel cylinders 20R of the left and right rear wheels via a first passage 31. The second hydraulic pressure generating chamber of the master cylinder 10 is connected to the wheel cylinders 20FL and 20FR for the left and right front wheels via a second passage 32 and a second branch passage 32A branching from the second passage 32.

Further, the first circulation passage 33 is branched from the first passage 31 to which the first storage chamber 41 is connected, and the second passage 32 and the second branch passage 32A are branched. And a second circulation passage 34 to which the second storage chamber 42 is connected.

In the vicinity of the branch between the first passage 31 and the first circulation passage 33, the first electromagnetic inflow valve 51A and the first electromagnetic inflow valve 51A serving as a switching control valve for switching and controlling the hydraulic pressure of the wheel cylinder 20R of the rear wheel. The outflow valve 52A controls the hydraulic pressure of each of the front wheel cylinders 20FL and 20FR in the vicinity of the second passage 32 and the branch portion between the second branch passage 32A and the second circulation passage 34. And a second electromagnetic outflow valve 52B, a third electromagnetic inflow valve 51C and a third electromagnetic outflow valve 52C, respectively.

The first to third electromagnetic inflow valves 51A to 51C are normally open 2-port 2-position solenoid valves, and the first to third electromagnetic outflow valves 52A to 52C are normally-closed 2-port 2-position solenoid valves. Yes, controlled by signals from the controller.

Of course, each electromagnetic inflow valve and each electromagnetic outflow valve may be integrated to form a 3-port 3-position electromagnetic valve.

Next, 70A and 70B are, for example, first and second plunger type pumps driven by a motor 71, which are provided in the first and second circulation passages 33 and 34, respectively. The discharge side of the pump is connected to the first passage 31 connected to the master cylinder 10, and the discharge side of the second pump is connected to the second passage 32.

The motor 71 is also controlled by a signal from the controller.

The controller is composed of a microcomputer or the like, inputs and calculates the data detected by the wheel speed sensor according to the control program, and the first to third electromagnetic inflow valves 51A to 51C and electromagnetic outflow valves 52A to 52C. And a process for controlling the drive of the motor 71.

Further, in the first and second passages 31 and 32, which are passages that connect the master cylinder 10 and the wheel cylinders 20 of the respective wheels 21, the pressure generated by the master cylinder 10 is actuated to increase the pressure. Plunger valves 60, 60 with throttles that pressurize the wheel cylinders 20 are provided only in the initial stage of the above.

Hereinafter, the details of the plunger valve 60 with a throttle will be described with reference to FIG.

Since the valves 60 provided in the first and second passages 31 and 32 are the same, the valves provided in the first passage 31 will be representatively described.

In the figure, A is a block body in which the valve 60 is housed, and a columnar space 61 and a large-diameter space 62 in the central portion which is continuous with the columnar space 61 are formed. Further, the master cylinder 10 side of the first passage 31 is opened at one end of the columnar space 61, and the wheel cylinder 20 side of the first passage 31 is opened in the large diameter space 62.

A plunger 63 is slidably accommodated in the columnar space 61, and the plunger 63 is attached to the master cylinder 10 side by a spring 65 contracted in a spring chamber 64 defined by one end of the plunger 63. It is energized. A stopper 66 is provided on the bottom surface of the spring chamber 64.

Further, a stepped hole 67 is formed in the plunger 63 so as to penetrate therethrough in the axial direction. The stepped holes 67 are referred to as 67A, 67B and 67C in order from the larger diameter, and a ball receiver 68 having a through hole 68A is provided at the open end of the large diameter portion 67A. A normally open check valve 69 composed of a ball 69A and a spring 69B is provided at the large diameter portion 67A and the medium diameter portion 67B. The small diameter portion 67C is provided with an aperture 67D. Further, the plunger 63 is formed with a radial hole 63B in a state of communicating with the small diameter portion 67C. This radial hole 63B is within the stroke range of the plunger 63. The communication state with the large diameter space 62 described above is maintained.

Further, a slant notch 63A is formed in the shoulder portion of the plunger 63 on the master cylinder 10 side, and when the plunger 63 makes a predetermined stroke through the slant notch 63A, the first notch on the master cylinder 10 side is formed. The passage and the large-diameter space 62 communicate with each other.

Next, the operation of this embodiment having the above configuration will be described.

(1) At the time of normal braking operation In a normal traveling state in which the braking operation is not performed, the first to third electromagnetic inflow valves 51A to 51C are open, and the first to third electromagnetic outflow valves 52A to 52C are It is in a closed state. The throttled plunger valve 60 is biased by the spring 65 as shown in FIG. 4 and is at the left end position in the figure.

When the brake pedal 12 is depressed by the brake operation and the hydraulic pressure on the master cylinder 10 side increases, the ball 69A moves right against the spring 69B, and the stepped hole 67 is closed. , The plunger 63 is pushed rightward in FIG. Then, the plunger 63 raises the internal pressure of the spring chamber 64 and causes the brake fluid to flow out from the spring chamber 64 through the throttle 67D. Then, the amount of the brake fluid flowing out through the throttle 67D, the plunger 63 further moves to the right, and finally the master cylinder 10 side and the wheel cylinder 20 side of the first passage 31 are directly communicated with each other via the oblique cutout 63A. A large amount of brake fluid will be applied to the wheel cylinder 20.

By the way, the time required for the master cylinder 10 and the wheel cylinder 10 to directly communicate with each other through the oblique cutout 63A from the start of the movement of the plunger 63 by this braking operation is about 20 to 50 msec, which is a delay in braking. It has no effect.

When the hydraulic pressures of the master cylinder 10 and the wheel cylinder 20 are balanced during the braking operation, the plunger 63 is returned by the spring 65 to the position shown in FIG. When the brake pedal 12 is returned in this state, the brake fluid in the wheel cylinder 20 returns to the master cylinder 10 via the normally open check valve 69.

(2) At the time of anti-skid control The anti-skid control is performed independently for the left and right front wheels and the rear wheel. Since the control is the same for both the front and rear wheels, the rear wheel will be representatively described.

When the controller operates based on the input from the wheel speed sensor when it is necessary to perform antilock control during braking operation when the brake pedal 12 is depressed, the controller issues a pressure reducing signal to the first controller. The electromagnetic inflow valve 51A is closed, the first electromagnetic outflow valve 52A is opened, the motor 71 is driven, and the first pump 70A drives the brake fluid in the wheel cylinders 20R, 20R of the rear wheels into the first circulation passage 33, Return to the master cylinder 10 via the first passage 31.

When maintaining the hydraulic pressure in the rear wheel cylinders 20R, 20R, the first electromagnetic outflow valve 52A is closed while the first electromagnetic inflow valve 51A is closed. In this state, the differential pressure on both sides of the plunger 63 becomes zero, so the plunger 63 is returned to the position shown in FIG. 4 by the spring 65.

When the re-increase signal is issued, the first electromagnetic outflow valve 52A is closed and the first electromagnetic inflow valve 51A is opened.

At the time of this re-pressurization, the hydraulic pressure on the master cylinder 10 side becomes high, the ball 69A is closed again, and the brake fluid for increasing the pressure of the wheel cylinder 20 is supplied from the spring 64 to the throttle 67D. Supplied through.

Therefore, abrupt pressure fluctuation is prevented and no surge occurs. Further, in the structure of this embodiment, the antilock control device can be additionally attached.

When the brake is released, the normally open check valve 69 is opened and the wheel cylinder 20 is depressurized as described above.

[0043]

[Effect of the device]

 As is apparent from the above description, according to the present invention, the plunger that is provided in the passage to the wheel cylinder, operates by the generated pressure of the master cylinder, and pressurizes the wheel cylinder with the throttling action only in the initial stage of the pressure increase. Since a normally open check valve is provided as a means, an anti-lock brake that does not reduce brake durability or fuel consumption while preventing the occurrence of surges during anti-skid control and delaying the start of braking The device can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention.

FIG. 2 is a sectional view showing a main part of an embodiment of the present invention,
It is in a normal braking state.

FIG. 3 is a sectional view showing an essential part of an embodiment of the present invention,
It is in the anti-lock control state.

FIG. 4 is a sectional view showing an essential part of an embodiment of the present invention,
The brake is released.

[Explanation of symbols]

 10 Master cylinder 20 Wheel cylinder 31 1st passage 32 2nd passage 33 1st circulation passage 34 2nd circulation passage 35 Bypass passage 36 Check valve 51 Electromagnetic inflow valve 52 Electromagnetic outflow valve 60 Plunger valve with throttle 63 Plunger 67D Throttle 69 Normal Open check valve

Claims (1)

[Scope of utility model registration request] 1. A passage that connects a master cylinder and a wheel cylinder of a brake device, a switching control valve that controls switching of the wheel cylinder to a depressurized, held, or boosted state during braking, and a passage provided in the passage. An antilock brake device comprising: a plunger means that moves by the generated pressure of the master cylinder and pressurizes the wheel cylinder only with an increasing action only in the initial stage of pressure increase, wherein the generated pressure of the master cylinder is reduced by the plunger means. The anti-lock brake system features a normally open check valve that opens the passage.