JP2542219B2 - Vehicle brake device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vehicle brake device that can easily start on an uphill road.

[Prior art]

Conventionally, one of these is, for example, Japanese Patent Application Laid-Open No.
As disclosed in Japanese Patent Laid-Open No. 119458, between a master cylinder that generates a brake pressure by depressing a pedal, a wheel cylinder that operates a wheel brake supplied with the brake pressure, and between the master cylinder and the wheel cylinder. A control that includes an electromagnetic valve that is provided and that can hold the pressure on the wheel cylinder side in response to a command from the outside, and a switch that detects a change in the acting direction of the braking force in the wheel brake, and that gives the command based on a signal from the switch It is known to have a circuit and.

This is because when the brake pressure is supplied from the master cylinder to the wheel cylinders by the depression of the pedal on an uphill road and the vehicle stops, the direction of the braking force in the wheel brakes moves backward from the direction in which the forward movement of the vehicle is blocked by the action of gravity. The change in the blocking direction is detected by the switch, and based on that, the control circuit issues a command to the solenoid valve, switches the solenoid valve so that the pressure on the wheel cylinder side is maintained, and the wheel is then moved according to the start of the vehicle. The switch detects that the driving force acting on the wheel brake has changed the direction of action of the braking force in the wheel brake to the direction that blocks forward movement again. Based on this, the command issued from the control circuit is released, and the solenoid valve is moved to the wheel. It is a switch to release the cylinder side pressure.

According to the above, even if the driver stops pedaling the brake pedal before starting the vehicle, the brake continues to operate and the vehicle is kept in the stopped state.At the time of starting, the driver causes the engine to stop and the vehicle to retreat. It is possible to easily start the vehicle on an uphill road without paying attention to the timing of the brake release operation and the accelerator and clutch operations so that there is no such situation.

[Problems to be Solved by the Present Invention]

However, in the above-mentioned one, when the electromagnetic valve is commanded and the pedal is not depressed, the occupant makes a large movement in the vehicle and the vehicle swings, causing the braking force to temporarily move forward. Change to prevent
If the command is temporarily released or the seal by the solenoid valve is incomplete, there is a problem that the held wheel cylinder side pressure drops. Such a decrease in holding pressure is more likely to occur as the stop time is longer, and the amount of decrease tends to increase.
Especially when the vehicle is stopped for a long time, the braking force at the wheel brakes becomes smaller than the braking force required to stop the vehicle, and there is a risk that the vehicle may move backwards on the uphill road against the driver's will. is there.

The present invention has been made in view of the above problems, and a vehicle brake capable of preventing insufficient braking force due to a decrease in holding pressure on the wheel cylinder side even when the vehicle stops for a long time on an uphill road. The purpose is to provide a device.

(Means of the present invention)

In order to achieve the above object, the present invention provides a valve device capable of disconnecting between the electromagnetic valve and the master cylinder according to the operation or operation of the parking brake.

[Operation of the means]

When the parking brake is operated after stopping the vehicle on an uphill road, the solenoid valve holds the pressure on the wheel cylinder side, and the valve device disconnects the master cylinder from the solenoid valve. For this reason, when the pedal is released and the pressure on the master cylinder side is released, the solenoid valve switches to release the holding pressure, and even if the solenoid valve seals incompletely, There is no pressure difference between the master cylinder side and the wheel cylinder side, and the retained pressure does not drop.

[Effect of the present invention]

In this way, according to the present invention, since the holding pressure is prevented from decreasing by the valve device, insufficient braking force is prevented even when the vehicle is stopped for a long time, and the vehicle is safely stopped on the uphill road. Can be kept.

〔Example〕

 An embodiment of the present invention shown in the drawings will be described below.

Referring to FIG. 1, a vehicle brake device is a disc in which one hydraulic pressure generation chamber of a tandem master cylinder 1 that generates hydraulic pressure by depressing a brake pedal 2 is attached to front wheels 7 a, 7 b via a pipe 3. It is connected to the wheel cylinder of the brake, and the other hydraulic pressure generating chamber is connected to the wheel cylinders 9a and 9b of the drum brake mounted on the rear wheels 8a and 8b via pipes 4,5 and 6.

On the other hand, the drum brake of the rear wheel 8a is a wheel cylinder.
A shoe that frictionally engages a drum (not shown) that rotates with the wheels in response to the hydraulic pressure supply of 9a to generate a braking force.
A sliding anchor that includes 10, 11 and can detect the movement of the shoes 10, 11 based on a change in the action direction of the braking force, and is slidable with respect to an anchor body 12 fixed to a back plate. Anchor with 13 and anchor body 12
An anchor switch 14 that is fixed to the anchor switch 14 and is capable of detecting the movement of the sliding anchor 13 with respect to the anchor body 12 via an actuator 15 is provided. When the vehicle is moving forward, the end of the shoe 10, which is the leading shoe, and the end of the shoe 11, which is the trailing shoe, are in contact with both ends of the sliding anchor 13 under the urging force of a spring (not shown). The sliding anchor 13 is pressed to the position moved to the shoe 11 side with respect to the main body 12 as shown by the fact that 10 receives a stronger spring force than the shoe 11. The anchor switch 14 is thus turned off when the sliding anchor 13 is located on the shoe 11 side and turned on when the sliding anchor 13 is moved to the shoe 10 side.

Between the pipes 5 and 6, a position A for communicating the valve device 20 side and the wheel cylinders 9a, b side, which will be described later, according to the de-excitation of the solenoid 16 and the wheel cylinder 9a, A solenoid valve 17 that is switched to a position B that shuts off the b side, and a check valve 18 that allows a flow from the valve device 20 side toward the wheel cylinders 9a, b side and prohibits the opposite are provided in parallel.
The solenoid 16 of the solenoid valve 17 is electrically connected to a control circuit (not shown) so that the demagnetization is controlled based on whether the anchor switch 14 is turned on or off.

The solenoid valve and the control circuit will be briefly described. As the solenoid valve 17, for example, as disclosed in Japanese Utility Model Publication No. 61-157056, a metal valve body is made of metal in accordance with the movement of the plunger due to the excitation of the solenoid. It suffices to use a switch that sits on the valve seat and switches to the above-mentioned position B. As a control circuit not shown, in addition to the anchor switch 14 described above,
For example, a main switch interlocked with an ignition switch, a switch for prohibiting excitation of a solenoid when the transmission is switched to a reverse position, a switch for detecting an uphill road, and the like are used.

A valve device 20 that can be opened and closed according to the operation of the parking lever 32 is provided between the pipes 4 and 5 of the brake device. The valve device 20 has an inlet 2 connected to the pipe 4.
1. A main body 23 having an outlet 22 connected to the pipe 5 is connected to an end of a parking lever 32 pivotally supported by a shaft 31 and slidably fitted in a hole 25 formed in the main body 23. The combined plunger 24 is connected outside the main body 23 to a wire 33 that transmits an operating force corresponding to the swinging operation of the parking lever 32 to a parking brake operating mechanism (not shown) of the rear wheels 8a, 8b. And again, the plungeer 24 has one shoulder
A spring 30 stretched between 24a and the main body 23 receives an urging force in the direction of being pulled into the main body 23, and the operating force applied from the parking lever 32 to the main body 23 becomes larger than the urging force of the spring 30. Then, from the position shown in contact with the bottom wall of the hole 25 toward the position where the shoulder portion 24a contacts the stepped portion 25a provided in the hole 25, the shoulder portion 24a can be displaced relative to the main body 23. The operation force of the parking lever 32 is transmitted to the wire 33 by the contact between the stepped portion 25a and the stepped portion 25a, and the movable portion can be moved integrally with the main body 23.

Such a valve device 20 has a hole that communicates with the main body 23 and the inlet 21.
A vacant space 26 that can connect 25 to the exit 22 is provided, and the vacant space is
A valve element 29 in which a synthetic rubber annular seal 29a that can be attached to and detached from a valve seat 28 formed on the hole 25 side is fixed in a valve 26, and a valve spring 27 that urges the valve element 29 toward the valve seat 28. And are housed. On the valve body 29, the other shoulder portion of the plunger 24 projects into the hole 25.
The leg 29b engageable with 24b is integrally provided, and the seal 29a of the valve body 29 is such that the leg 29b and the shoulder 24b are engaged with each other when the plunger 24 is at the position shown in the drawing in which the plunger 24 abuts the bottom wall of the hole 25. By valve seat 27
The plunger 24 is moved away from the shoulder 24a and the step 2
When it is moved to the position where it abuts with 5a, it sits on the valve seat 27,
A check valve is formed to allow the liquid movement from the inlet 21 side toward the outlet 22 side but prohibit the opposite. In addition,
The large diameter portion of the plunger 24 where the shoulder portions 24a, b are formed is provided with a groove extending in the axial direction so as to form a liquid passage between itself and the inner wall of the hole 25, and the hole 25 of the hole 25 is formed through this groove. The entrance side 21 side and the vacant space 26 side communicate with each other.

The vehicle brake device shown in FIG. 1 is configured as described above. Next, its operation will be described.

If the vehicle is running now, the parking lever
32 is in the position shown in the figure for releasing the parking brake, and in the valve device 20, the plunger 24 receives the biasing force of the spring 30 and abuts against the bottom wall of the hole 25 so that the shoulder portion 24b
Is engaged with the leg portion 29b of the valve body 29, and the seal 29a of the valve body 29 is
Is separated from the valve seat 28, and the inlet 21 side and the outlet 22 side communicate with each other. Further, the solenoid valve 17 has an anchor switch 14
Is off and the solenoid 16 is demagnetized and is in position A.

In this state, if the brake pedal 2 is stepped on to stop the vehicle after the vehicle has entered the uphill road, the hydraulic pressure generated in the master cylinder 1 is applied to the wheel cylinders of the front wheels 7a, 7b via the pipe 3. As well as being supplied
It is supplied to the wheel cylinders 9a and 9b of the rear wheels 8a and 8b through the pipe 4, the valve device 20 in the opened state, the pipe 5, the solenoid valve 17 and the pipe 6, and the brakes act on all the wheels. In the rear wheel 8a, the shoes 10 and 11 frictionally engage with a drum (not shown) rotating together with the wheel in the direction of arrow R (clockwise).

When the vehicle stops on the uphill road in this way, in the rear wheel 8a, a turning force in the direction opposite to the arrow R is generated on the drum by the action of gravity, and the direction of the braking force moves backward from the direction in which the forward movement of the vehicle is blocked. By changing to the blocking direction, the shoe 11 receives a braking reaction force larger than that of the shoe 10 and presses the sliding anchor 13 to move it to the shoe 10 side with respect to the anchor body 12. Then, the anchor switch
14 switches from off to on, and based on this, the solenoid
16 is excited and the solenoid valve 17 switches to position B. Therefore,
The pipe 5 side and the pipe 6 side of the solenoid valve 17 are cut off, and the solenoid valve 17
Further, the check valve 18 prevents the hydraulic pressure supplied to the wheel cylinders 9a, 9b from being released to the pipe 5 side.
Then, in synchronism with the switching of the solenoid valve 17 described above, an operation of swinging the parking lever 32 counterclockwise about the shaft 31 as a fulcrum so as to operate the parking brake is performed. The body 23 is moved to the right in the figure with respect to the plunger 24 against the biasing force of the spring 30,
Plunger 24 is displaced to a position where its shoulder 24a abuts step 25b. In response to this, the valve body 29 that is inclined with respect to the valve seat 28 due to the engagement between the shoulder portion 24b and the leg portion 29b swings due to the urging force of the valve spring 27, and the seal 29a has its valve seat 29a. Sit on 28. Thus, when the valve device 20 is closed, the pipes 5 and 4
, That is, between the solenoid valve 17 and the master cylinder 1.

In this way, when the brake pedal 2 is released after the wheel cylinders 9a, b side are blocked from the master cylinder 1 side by the solenoid valve 17 and the valve device 20, the wheel cylinders of the front wheels 7a, 7b are released. The supplied hydraulic pressure is released to the master cylinder 1 side, but the hydraulic pressure supplied to the wheel cylinders 9a, b of the rear wheels 8a, b is retained. Then, in the unlikely event that a large movement of the passenger in the vehicle causes the vehicle to swing, the action direction of the braking force on the rear wheel 8a changes to a direction that temporarily blocks forward movement, and the anchor switch 14
Is temporarily turned off and the solenoid valve 17 is temporarily switched to position A, or in the solenoid valve 17 switched to position B, the valve body is not fully seated on the valve seat and a minute gap is formed between the two. Even if a malfunction occurs, the solenoid valve 17 is shut off from the master cylinder 1 side by the valve device 20, so the wheel cylinders 9a, b side of the solenoid valve 17 and the valve device are not connected.
There is no pressure difference between the 20 side and the hydraulic pressure held in the wheel cylinders 9a and 9b. Therefore, the braking force corresponding to the hydraulic pressure retained in the wheel cylinders 9a, b is applied to the rear wheels 8a, b.
The vehicle remains stationary on the uphill road.

When the pedal 2 is depressed to increase the holding hydraulic pressure after the wheel cylinders 9a and 9b are shut off from the master cylinder 1 side by the solenoid valve 17 and the valve device 20 as described above, the master cylinder 1 The generated fluid pressure is
20 valve bodies 29 are separated from valve seats 28 while inlet 21 to outlet 22
Wheel cylinders 9a, b via check valve 18.
Is supplied to.

When starting a vehicle that has been stopped as described above, first of all, the parking lever 32 is swung clockwise around the shaft 31 as a fulcrum so as to release the parking brake before the accelerator is depressed and the clutch is engaged. When the operation is performed, in the valve device 20, between the main body 23 and the plunger 24, the plunger 24 moves toward the position (illustrated position) where the plunger 24 abuts the bottom wall of the hole 25 with respect to the main body 23 by the urging force of the spring 30. Relative displacement is generated. Then, in response thereto, the valve body 29 in which the leg portion 29b engages with the shoulder portion 24b of the plunger 24 is tilted with respect to the valve seat 28, and the seal 29a thereof is separated from the valve seat 28, and the inlet 21 side And the outlet 22 side communicate with each other, and the pipes 4 and 5 are communicated with each other to open the valve.

After this, when the accelerator is stepped on and the clutch is joined, the driving force is transmitted to the wheels, so that in the rear wheels 8a, a turning force is generated in the drum in the direction of arrow R, and the acting direction of the braking force is changed. The direction in which the vehicle is prevented from moving backward is changed to the direction in which the vehicle is prevented from moving forward. Then, the shoe 10 receives a larger braking reaction force than the shoe 11, so that the sliding anchor is moved to the illustrated position on the shoe 11 side with respect to the main body 12, and the anchor switch 14 is turned off. Then, based on this, the solenoid 16 is demagnetized to switch the solenoid valve 17 to the position A, and the pipe 5
Side and 6 side are connected. Therefore, the wheel cylinder 9
The hydraulic pressure held in a and b is released to the master cylinder 1 side via the solenoid valve 17 and the valve device 20 that is already open, and the driving force transmitted to the wheels increases. Together, the brakes acting on the rear wheels 8a and 8b are released, so that the vehicle starts on an uphill road.

As described above, in the embodiment shown in FIG. 1, the parking lever that actuates the parking brake.
Since the valve device 20 that can shut off between the solenoid valve 17 and the master cylinder 1 according to the operation of 32 is provided, the solenoid valve 17 is operated by the above operation of the parking lever 32 when the vehicle is stopped on an uphill road. Even if there is a problem such that the wheel cylinders 9a, b side and the master cylinder 1 side communicate with each other,
The retained hydraulic pressure is prevented from decreasing. Therefore,
It is possible to prevent insufficient braking force even when the vehicle is stopped for a long time, and to keep the vehicle safely stopped on an uphill road. Further, although it is necessary to operate the parking lever 32, it is not necessary to synchronize the operation with the operation of the accelerator and the clutch when starting the vehicle, so that the function of easily starting the vehicle on an uphill road is not impaired. Absent.

Although the embodiment shown in FIG. 1 has been described above, the present invention is not limited to this.
Instead of directly connecting the end of the parking lever 32 to the parking lever 32, the valve device 20 may be connected via a wire so that the valve device 20 can be opened and closed according to the operation of the wire accompanying the operation of the parking lever. Instead of performing the valve closing operation by the traction force according to the operation of the parking lever as described above, the valve closing operation may be performed by the pressing force as shown in FIG.

In the valve device 120 shown in FIG. 2, a push rod 140 is swingably connected between a shaft 131 serving as a fulcrum of the parking lever 132 and an end portion to which the wire 133 is connected, and the parking lever 132 is rotated counterclockwise. When the operation for swinging in the direction is performed, the plunger 124 receives a pressing force from the push rod 140, and the hole 125 is formed in the main body 123 fixed to the vehicle body.
A seal 129a made of synthetic rubber attached to the inner end portion of the plunger 124 is moved so as to be pushed in, and is seated on the valve seat 128 of the piston 141. Then, the piston 141 is biased toward the plunger 124 side by the spring 142 (a spring stronger than the spring stretched between the plunger 124 and the piston 141) so as to come into contact with the step portion of the hole 125, and Exit the inside of the hole 125 against the biasing force of the 142
When the seal 29a is seated on the valve seat 128 by pushing the plunger 124, a check valve is formed that prohibits the flow from the outlet 122 side toward the inlet 121 side, but allows the reverse. It has become so. Such valve device
Even with 120, the same action and effect as those of the valve device 20 of FIG. 1 can be obtained.

Further, in FIG. 1, a change in the action direction of the braking force based on a change in the action direction of the frictional force generated between the drum and the shoe of the drum brake is detected, and the pressure of the brake system of the rear wheel can be maintained. However, the present invention detects the change in the action direction of the braking force based on the change in the action direction of the friction force generated between the disc and the pad of the disc brake, the brake system of the front wheels, It can also be applied to a device that can hold the pressure of both front and rear wheel brake systems or one of the so-called X piping brake systems. Also, as a parking brake operation member, a stick-type lever that is axially moved, a foot-operated type It can also be applied to those using a pedal or the like.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of the present invention together with a sectional view of its essential part, and FIG. 2 is a sectional view showing an embodiment of the essential part of the present invention which is different. 1 ... Tandem master cylinder 9a, 9b ... Wheel cylinder 14 ... Anchor switch 17 ... Solenoid valve, 20,120 ... Valve device

Claims (1)

(57) [Claims] 1. A master cylinder that generates a brake pressure by depressing a pedal, a wheel cylinder that is supplied with the brake pressure to operate a wheel brake, and a master cylinder that is provided between the master cylinder and the wheel cylinder. An electromagnetic valve capable of holding the pressure on the wheel cylinder side in response to a command, and a control circuit including a switch for detecting a change in the acting direction of the braking force in the wheel brake and giving the command based on a signal from the switch are provided. In a vehicle brake device, a vehicle brake device provided with a valve device capable of disconnecting between the electromagnetic valve and the master cylinder according to an operation or an operation of a parking brake.