JP2891166B2 - Brake actuator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake actuator suitable for use in a parking brake safety device provided to secure the safety of a parked vehicle.

[0002]

2. Description of the Related Art Conventionally, in vehicles such as automobiles, brake assist devices have been developed which can reduce the troublesome operation of a driver to brake. Such a conventional brake assist device is a device in which a computer detects when the vehicle stops due to a brake operation, and holds the brake fluid pressure when the brake pedal is depressed even when the driver releases his / her foot from the brake pedal. This allows the driver to keep the vehicle stationary without continuing to depress the brake pedal. When the driver puts the clutch in the engaged state, the operation of the above-described brake assist device is released, and normal traveling can be performed.

A specific description of such a device will be given below. For example, a brake actuator for maintaining brake fluid pressure is provided on a hydraulic oil supply path of a vehicle brake, and the vehicle is stopped while a brake pedal is depressed. Is continued for a predetermined period of time, and then when the foot is released from the brake pedal, the controller detects this and supplies air pressure or the like to the actuator to maintain the braking force.

[0004] This eliminates the need to continue to depress the brake pedal during traffic congestion or signal waiting, thereby reducing physical and mental fatigue. In addition, the vehicle can easily start on a slope and the like, and furthermore, when a rear-end collision occurs, the damage can be minimized and the accident can be prevented from spreading.

[0005]

However, such a conventional brake assist device is designed to keep the brake fluid pressure constant at the time of operation, and is used when a parked vehicle starts moving on a slope or the like. However, it was not something that actively increased the braking force to stop the vehicle. Under such circumstances, for example, the following parking brake safety device can be considered as one of the brake assist devices that can ensure sufficient safety. That is, an actuator or the like that can pressurize the brake oil is provided in the brake oil supply system of the vehicle, and when the vehicle starts to move naturally, for example, when parking on a slope without sufficiently pulling the parking brake lever, this is detected. Activate the actuator. Thus, the brake fluid pressure is increased to increase the braking force of the vehicle.

As a structure of such an actuator, for example, one shown in FIG. 15 can be considered. That is, the brake actuator 19 operates in response to an operation command from the controller 9, and
The controller 9 controls the brake actuator 19 based on the detection information from each sensor to increase or decrease the brake fluid pressure.

Here, the brake actuator 19
As shown in FIG. 15, mainly, an actuating section (power generation section) 22, a casing (actuator housing section) 2
3, a hydraulic chamber (hydraulic pressure generating unit) 24 and a piston (pressure increasing member or piston member) 25.

[0008] The actuating section 22 is a rotary driving section that generates a rotational force.
Is constituted by a motor (electric motor). FIG.
As shown in FIG. 5, a space portion (cylinder) 23A is formed in the casing 23, and a piston 25 is disposed in the cylinder 23A so as to be able to move forward and backward.

A hydraulic chamber 24 is formed in the cylinder 23A. The volume of the hydraulic chamber 24 is changed by moving a piston 25 by using the rotational force generated by the motor 22, so that a rear wheel brake is provided. The hydraulic pressure to the brake operating member side (for example, a brake shoe or a brake pad) of the hydraulic pressure supply system 6 is increased.

A speed reduction mechanism 130 including a pinion gear 130A and a driven gear 130B is interposed between the motor 22 and the piston 25. Here, the driven gear 130B is fixed to the piston drive shaft 131 by a gear pin 132.
A male screw 131A is formed on the distal end side of 1. The screw mechanism 28 is configured by the male screw 131A and the nut 27.

A sleeve 136 for restricting the rotation of the nut 27 is fitted in the casing 23. On the other hand, a recess 135 having a larger diameter than the piston drive shaft 131 is formed at the base of the piston 25, and the piston drive shaft 131 is housed in the recess 135.

When the piston drive shaft 131 rotates, the nut 27 moves in the axial direction with the sleeve 136 as a guide. Here, for example, when the drive signal to the motor 22 is a control signal that increases the brake fluid pressure, the nut 27 is driven to the left in the figure.

When the nut 27 is driven in this manner, the nut 27 comes into contact with the base end of the piston 25 to move the piston 25 forward (to the left in the drawing).
That is, the capacity of the hydraulic chamber 24 is reduced. Further, a return spring 31 is provided in the hydraulic chamber 24, and urges the piston 25 in a retreating direction (right side in the figure).

Further, as shown in FIG.
, A long hole 139 is formed over the length of the piston operation stroke, and a stopper bolt 137 is disposed in the long hole 139 so as to penetrate therethrough. The stopper bolt 137 is fixed to the casing 23, and the front end position and the rear end position of the piston 25 are regulated by the stopper bolt 137 abutting on the front and rear ends of the long hole portion 139.

The hydraulic chamber 24 communicates with the hydraulic pressure supply system 6 on the master cylinder 5 side to supply a brake oil to the hydraulic chamber 24 with a first communication port 29 and a brake operating member (a brake shoe or the like). A second communication port 30 that communicates with the brake fluid pressure supply system 6 on the (brake pad) side and supplies the brake oil adjusted to a predetermined oil pressure in the hydraulic chamber 24 to the brake operating member side is formed.

When the piston 25 moves forward to increase the brake fluid pressure, the first communication port 29
The second communication port 30 is closed by a valve mechanism 32, so that the hydraulic pressure of the brake hydraulic pressure supply system 6 on the brake operating member side is reliably increased.

Here, the valve mechanism 32 will be described. The valve mechanism 32 mainly includes a valve 138, a return spring 141, a hydraulic oil supply communication passage 142, and the like. That is, the valve 138 and the return spring 141 are disposed inside the distal end of the piston 25. A communication passage (hereinafter, simply referred to as a communication passage) 142 for supplying hydraulic oil for supplying brake oil from the master cylinder 5 side to the hydraulic chamber 24 is formed coaxially with the central axis of the piston 25. .

The communication passage 142 is connected to the communication passage 14.
The stem of the valve 138 having a diameter smaller than 2 is inserted. The valve 138 itself is urged by a return spring 141 to the right side in the drawing to close the communication path 142. The stem of the valve 138 is formed longer than the communication path 142 by a predetermined amount.

As a result, when the piston 25 retreats to the rear end, the stem of the valve 138 is
, The valve 138 moves against the urging force of the return spring 141, and the communication passage 142 is opened.
When the piston 25 advances by a predetermined amount, the valve 1
As the stem 38 is separated from the stopper bolt 137, the valve 138 is moved by the urging force of the return spring 141, and the communication path 142 is closed.

Incidentally, the piston 25 is connected to the first communication port 2.
9 is formed smaller in diameter than the cylinder 23A, so that a space 140 is formed over the entire circumference between the piston 25 and the cylinder 23A. Therefore, when the communication path 142 is opened, the hydraulic oil from the first communication port 29 reaches the inside of the distal end of the piston 25 through the space 140, the elongated hole 139, and the communication path 142.

A communication hole 25A communicating with the hydraulic chamber 24 is provided inside the distal end of the piston 25. The hydraulic oil supplied from the communication passage 142 into the distal end of the piston 25 passes through the communication hole 25A. The hydraulic pressure is supplied to the hydraulic chamber 24 via the hydraulic pump. Therefore, when the piston 25 is retracted to the rear end, the first communication port 29 and the second communication port 30 are in a communication state, and when the piston 25 advances by a predetermined amount, the first communication port 2
9 and the second communication port 30 are cut off.

In the drawings, reference numerals 69, 133 and 134 denote a rubber cup (seal member), a thrust bearing and a stopper, respectively. Although not shown, the brake actuator is provided with a pressure switch, and the pressure switch is connected to a controller 9 as control means.

When detecting the ON signal of the pressure switch, the controller 9 determines that the hydraulic pressure has been sufficiently increased by the brake actuator 19, and
The operation of the motor 22 is stopped.

The brake actuator 19 mainly includes a switch body 126A and a sensor rod 126B.
Switch 1 consisting of a rod guide 126C
26 is also provided, and is connected to the controller 9. Contrary to the above, the limit switch 126 is for preventing the motor 22 from over-rotating when the piston 25 is retracted to the rear end. When the nut 27 is retracted to a predetermined position, an ON signal is generated. It is a sensor that outputs.

In this limit switch 126, the stem of the valve 138 of the valve mechanism 32 is connected to the stopper bolt 13
7 is set so as to output an ON signal after the hydraulic oil supply communication passage 142 is reliably opened, whereby the first communication port 29 and the second communication port 30 are communicated with each other. The piston 25 stops. This is to ensure that the normal service brake is operated.

When the nut 27 moves forward based on a control signal from the controller 9, the sensor rod 126
As B moves downward, the limit switch 126
Turns off. By using such a brake actuator, for example, when a vehicle parked on a slope or the like starts to move, the braking force can be actively increased to stop the vehicle.

However, with such a brake actuator, if the driver depresses the brake pedal carelessly despite the fact that the parking brake safety device is operating, the brake fluid pressure will increase more than necessary. Further, there is a problem that a large driving force is required for the brake actuator when the operation of the parking brake safety device is released.

That is, in such a case, the brake oil from the master cylinder side is supplied to the hydraulic chamber 24 through the first communication port 29 and the valve mechanism 32.
When the parking brake safety device is activated, the valve mechanism 32 is in the first position.
Since it acts as a check valve that allows the flow of the brake oil only in one direction from the communication port 29 side to the hydraulic chamber 24 side, the brake fluid pressure increases more than necessary.

In order to solve such a problem, it is conceivable to increase the driving force of the brake actuator. However, in such a case, the brake actuator itself may be increased in size, resulting in an increase in cost and weight. There is a problem of doing it. The present invention has been made in view of such a problem, and an object of the present invention is to provide a brake actuator that does not increase brake fluid pressure more than necessary when the above-described parking brake safety device operates. .

[0030]

According to a first aspect of the present invention, there is provided a brake actuator having a first connection port connected to a master cylinder and a second connection port connected to a wheel cylinder. A piston slidably inserted into the cylinder and separating a first chamber communicating with the first connection port inside the cylinder and a second chamber communicating with the second connection port; A communication passage communicating the chamber and the second chamber is urged from the master cylinder side in a direction to close the first connection port, and the piston is at an initial position in response to an urging force from the master cylinder side. A first valve configured to open the first connection port in opposition and close the first connection port by the urging force when the piston is displaced toward the second chamber; Those who close the communication passage from At the initial position of the piston against the urging force from the second chamber side to open the communication passage, and when the piston is displaced toward the second chamber side, the urging force A second valve configured to close the communication passage; and a driving unit that increases the pressure of the wheel cylinder by displacing the piston from the initial position toward the second chamber. Features.

According to a second aspect of the present invention, there is provided a brake actuator according to the first aspect, wherein the first valve has a valve body capable of closing the first connection port, A return spring biased from the master cylinder side,
A rod interposed between the valve body and the outer periphery of the piston in the first connection port, and presses the valve body in the opening direction via the rod in an initial state of the piston. It is characterized in that the outer periphery of the piston is formed in a shape.

According to a third aspect of the present invention, there is provided the brake actuator according to the first or second aspect, further comprising a control unit for controlling the operation of the driving unit.
The control means is configured to operate the drive means to displace the piston toward the second chamber when detecting that the vehicle has moved during the operation of the parking brake.

[0033]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic sectional view of a brake actuator according to an embodiment of the present invention; FIG. 1 is a partially enlarged view of FIG. 2, FIG. 2 is a cross-sectional view taken along line AA of FIG. 3, and FIGS. 4 and 5 are schematic structural views showing their external shapes. FIG. 2, FIG. 5 is a view in the direction of arrow C in FIG. 3, FIG. 6 is a schematic diagram showing the overall configuration of a vehicle using the brake actuator, and FIG. 7 is a schematic diagram showing the overall configuration of the control system. FIG. 8 is a flowchart for simply explaining the operation, FIG. 9 is a diagram for simply explaining the operation, and FIG.
0 is a diagram for simply explaining the release operation, FIG. 11 is a diagram for explaining the operation at the time of the fail check, FIG. 12 is a diagram for explaining the items of the fail check, and FIG. 13 and FIG. 13 is a graph for explaining the operation of the brake actuator, FIG. 13 is a graph showing changes in hydraulic fluid pressure and motor current when the piston of the brake actuator moves forward, and FIG. 14 is a graph showing hydraulic pressure of the hydraulic fluid when the piston retracts. 5 is a graph showing a change in current of the motor.

(1) Description of Overall Configuration As shown in FIG. 6, the vehicle 1 is provided with a brake device. The brake device includes a hill start assist device 50 and a parking brake safety device as brake assist devices. 60
The devices 50 and 60 interact with each other to facilitate starting of the vehicle 1 on a slope,
The security of the parked vehicle 1 can be ensured.

(1.1) Description of Slope Start Assist Device First, the above-described slope start assist device 50 will be described. This slope start assist device 50 depresses a brake pedal (service brake operating member) 4 shown in FIG. In vehicle 1
Is stopped, and when it is detected for a predetermined time or more that the driver has depressed the brake pedal 4 and the vehicle 1 has stopped, the brake hydraulic pressure supply system (the incompressible fluid for brake operation) is operated. A switching valve (magnet valve) 7 provided in the supply system 6 is switched to seal the brake oil in the brake fluid pressure supply system 6 and maintain the braking force even when the driver releases his / her foot from the brake pedal 4. It has become.

As shown in FIG. 6, the vehicle 1 is provided with a front wheel brake (front wheel brake) 2 and a rear wheel brake (rear wheel brake) 3.
Normally, when the driver depresses the brake pedal 4, the driver's brake depression force is boosted by the master cylinder 5, and the fluid pressure (brake fluid pressure) of the incompressible fluid (brake fluid or brake oil) for brake operation is applied. Is to be increased. Then, a brake shoe or a brake pad (both not shown) as a service brake operating member is operated by the brake fluid pressure to apply a braking force to the vehicle 1.

The brake fluid pressure supply system 6 on the rear wheel side of the vehicle 1 is also provided with an LSV (load sensing valve) 8. The LSV 8 is for detecting a load mainly on the rear wheel side of the vehicle 1 from the deflection of the rear spring and supplying a brake fluid pressure corresponding to the loaded load of the vehicle 1 to the rear wheel brake 3. Incidentally, the magnet valve 7 of the above-described slope start assist device 50 is controlled by a controller 9 as control means. As shown in FIG. 6, the controller 9 includes an operation switch 10, an adjustment switch 11, a clutch pedal stroke sensor (clutch sensor) 12, a vehicle speed sensor (vehicle speed detecting means) 13, a neutral switch (shift position detecting means) 14, A stop lamp switch (or service brake operating member operating state detecting means) 15, a parking switch (parking brake operating state detecting means) 16, a door switch 17, a key switch 18 as an engine operating state detecting means, and a pressure, which will be described in detail later. A switch (pressure detecting member) 125 and a limit switch 126 are connected, and the operation of the magnet valve 7 is controlled based on detection information from these sensors.

Here, the operation switch 10 is an on / off switch disposed around the driver, and when the operation switch 10 is turned on, the slope start assist device 5 is turned on.
When the operation switch 10 is turned off, the hill start assist device 50 does not operate. The adjustment switch 11 adjusts the operation of the slope start assist device 50, and is a switch that adjusts the timing of releasing from the state in which the brake fluid pressure is held.

The clutch pedal stroke sensor (clutch sensor) 12 is a sensor that detects when the driver steps on a clutch pedal (not shown) and outputs an ON signal, and a vehicle speed sensor (vehicle speed detecting means). ) 13
Is a power cutoff switch 6 for a vehicle speed sensor as a cutoff means.
4 is an active vehicle speed detecting means for detecting the vehicle speed by receiving the power supply from the battery 68 via the power supply 4.

The neutral switch 14 is provided as shift position detecting means for detecting the shift position of the transmission. The neutral switch 14 outputs an ON signal only when the shift position of the transmission is in the neutral position. Has become. The stop lamp switch 15 is provided as a service brake operating member operating state detecting means. That is, the stop lamp switch 15
Is for detecting the operation state of the brake pedal (that is, the service brake operating member) 4. When the driver depresses the brake pedal 4, this is detected, and an ON signal is also output.

A parking switch (parking brake operating state detecting means) 16 is a switch for detecting an operating state of a parking brake operating member (ie, parking brake lever, not shown). The operation state of the parking brake is detected based on the state. Door switch 1
Reference numeral 7 denotes a sensor capable of detecting whether the door on the driver's seat side of the vehicle 1 is open or closed. A key switch (engine operating state detecting means) 18 detects whether the engine (not shown) is operating (when the engine is on). Or, a sensor that detects whether the engine is not operating (when the engine is off).

The pressure switch (pressure detecting member) 12
5 and the limit switch 126 will be described later.

Further, as shown in FIG.
Is connected to an alarm lamp 20 and an alarm buzzer 21, and issues an alarm to the driver when the operation state of the slope start assist device 50 and the state of the vehicle 1 satisfy predetermined conditions. . This will be described later in detail. (1.2) Description of Parking Brake Safety Device Next, the parking brake safety device 60 will be described. After the parking brake safety device 60 stops the vehicle 1 under predetermined conditions, the driver does not When the vehicle 1 starts moving even though no operation is performed, the vehicle 1 operates to stop the vehicle 1.

That is, the parking brake safety device 60
For example, when the vehicle 1 starts to move naturally due to the effect of gravity or the like when the parking brake lever is not sufficiently pulled and the vehicle 1 is parked on a slope, this is detected and the brake fluid pressure is increased to mechanically increase the brake fluid pressure. The rear wheel brake 3 is operated. Therefore, as shown in FIG. 6, a brake actuator (fluid pressure increasing mechanism) that can adjust the brake fluid pressure is provided between the magnet valve 7 of the rear wheel side brake fluid pressure supply system 6 and the rear wheel brake 3. 19 are provided.

The brake actuator 19 operates in response to an operation command from the controller 9 as the above-mentioned control means. The controller 9 detects the signals from the sensors 10 to 18, 125, 126 described above. By controlling the brake actuator 19 based on the information, the operation of the parking brake safety device 60 is controlled.

Hereinafter, the above-described brake actuator 19 will be described.
Will be described in detail with reference to FIGS. As shown in FIGS. 2 and 3, the brake actuator 19 mainly includes an actuating section (power generation section) 22, a casing (actuator housing section) 23, and a piston (pressure increasing member or piston member) as driving means. 25.

The actuating section 22 is a rotary driving section for generating a rotational force.
Is constituted by a motor (electric motor). FIG.
As shown in (2), a space (cylinder) 23A is formed in the casing 23, and a piston 25 is disposed in the cylinder 23A so as to be able to move forward and backward.

In the cylinder 23A, a first hydraulic chamber (first chamber) 24A and a second hydraulic chamber (second chamber) 2
4B, and the piston 25 is moved by using the rotational force generated by the motor 22 to change the volume of the second hydraulic chamber 24B, so that the brake hydraulic pressure supply system 6 on the rear wheel side is changed. The brake fluid pressure of a wheel cylinder (not shown) is increased.

The motor 22 is connected to the piston 25
As shown in FIG. 3, a reduction mechanism (rotational force transmission mechanism) 130 including a pinion gear 130A and a driven gear 130B is provided between the motor 22 and the piston 25. Is interposed. And
The motor 22 is configured to rotate in response to a command signal from the controller 9, thereby driving the piston 25 via the speed reduction mechanism 130.

Here, a mechanism for driving the piston 25 will be described. The driven gear 130B is fixed to a piston drive shaft 131 by a gear pin 132. As shown in FIGS. Axis 1
An external thread 131 </ b> A is formed on the tip end side (on the piston 25 side and on the left side in the figure) of 31. Also, this male screw 1
A nut 27 as a moving member is screwed and disposed on 31 </ b> A, and a sleeve 136 for restricting rotation of the nut 27 is fitted in the casing 23. The nut 27 is a regular hexagonal hexagonal nut when viewed from the axial direction.
Is formed according to the shape of.

The male screw 131A of the piston drive shaft 131 and the nut 27 constitute a screw mechanism 28. On the other hand, as shown in FIGS. 2 and 3, a recess 135 having a larger diameter than the piston drive shaft 131 is formed at the base of the piston 25.
When there is almost no piston stroke (that is, when the piston 25 is at the initial position on the right side in the figure), the piston drive shaft 131 is housed in the recess 135.

The motor 22 is connected to the controller 9. When the motor 22 rotates based on a control signal from the controller 9, the rotation driving force is transmitted to the piston driving shaft 131 via the speed reduction mechanism 130. And
The piston drive shaft 131 is rotated.
When the piston drive shaft 131 rotates, the nut 27 whose rotation is restricted moves in the axial direction with the sleeve 136 as a guide. Here, for example, when the drive signal to the motor 22 is a control signal that increases the brake fluid pressure, the nut 27 is driven to the left in the figure.

When the nut 27 is driven in this manner, the nut 27 comes into contact with the base end of the piston 25 to move the piston 25 forward (to the left in the drawing).
That is, the volume of the second hydraulic chamber 24B is reduced. Also,
A return spring 31 is provided in the second hydraulic chamber 24B, and urges the piston 25 in a retreating direction (right side in the figure). Thus, when the motor 22 rotates in the opposite direction to the above and the nut 27 retreats, the piston 25 retreats by the urging force of the return spring 31.

As shown in FIGS. 1 and 2, a long hole 139 is formed in the piston 25 over the length of the piston operation stroke, and a stopper bolt 137 is formed in the long hole 139. Are arranged to penetrate.
The stopper bolt 137 is fixed to the casing 23, and the stopper bolt 137 is
, The rear end position of the piston 25 is regulated. Also, like this,
When the stopper bolt 137 comes into contact with the right end of the elongated hole portion 139, the tip position of the piston 25 is regulated.

As shown in FIG. 1, the actuator 19 has a hydraulic pressure supply system 6 on the master cylinder 5 side.
And a first connection port (or one communication port) 29 that can supply brake oil to the first hydraulic chamber 24A and the brake fluid pressure supply system 6 side of the wheel cylinder, that is, a brake operating member (a brake shoe or A second connection port (or a second communication port) that communicates with the brake fluid pressure supply system 6 on the (brake pad) side to supply the brake oil adjusted to a predetermined hydraulic pressure in the second hydraulic chamber 24B to the wheel cylinder side. 30 are formed.

As described above, the second hydraulic chamber 24B
The internal volume is changed by the forward and backward movement of the piston 25, but when the piston 25 moves forward to increase the brake fluid pressure, the first communication port 29 and the The two communication ports 30 are closed by a second valve mechanism (second valve) 32 shown in FIGS.
Thereby, the hydraulic pressure of the brake hydraulic pressure supply system 6 on the brake operating member side is reliably increased.

Now, the second valve mechanism 32 will be described. As shown in FIGS.
It mainly comprises a valve 138, a return spring 141 and the like. That is, as shown in FIG. 1, a valve 138 and a return spring 141 are disposed inside the distal end of the piston 25. The first hydraulic chamber 24A and the second hydraulic chamber 2 are coaxial with the center axis of the piston 25.
A communication passage (hereinafter, referred to as a communication passage) 142 for supplying hydraulic oil is formed to communicate with the brake oil 4B. The brake oil supplied from the master cylinder 5 side to the first hydraulic chamber 24A passes through the communication passage 142. And is supplied to the second hydraulic chamber 24B.

The communication passage 142 is connected to the communication passage 14.
The stem of a valve 138 having a diameter smaller than 2 is inserted through the valve 138, and the valve 138 itself is urged by a return spring 141 to the right side in the drawing to close the communication path 142. The stem of the valve 138 is formed longer than the communication path 142 by a predetermined amount.

As a result, when the piston 25 retreats to the rear end, the stem of the valve 138 is
, The valve 138 moves against the urging force of the return spring 141, and the communication passage 142 is opened. When the piston 25 advances by a predetermined amount, the stem of the valve 138 is
And the valve 138 is moved by the urging force of the return spring 141, so that the communication passage 142 is closed.

By the way, as shown in FIGS. 1 and 2, the piston 25 is located at a position corresponding to the first communication port 29.
It is formed smaller in diameter than the cylinder 23A, so that a space 140 is formed over the entire circumference between the piston 25 and the cylinder 23A. Therefore, when the communication path 142 is opened, the hydraulic oil from the first communication port 29 reaches the inside of the distal end of the piston 25 through the space 140, the elongated hole 139, and the communication path 142.

The second end of the piston 25 has
A communication hole 25 </ b> A communicating with the hydraulic chamber 24 </ b> B is provided, and the hydraulic oil supplied from the communication passage 142 into the distal end of the piston 25 passes through the communication hole 25 </ b> A to the second hydraulic chamber 2.
4B. With such a configuration, when the piston 25 is retracted to the rear end (that is, the initial position of the piston 25), the first communication port 29 and the second communication port 30 are in communication with each other, and the piston 25 When the fixed forward movement is performed, the first communication port 29 and the second communication port 30 are shut off.

In the figure, reference numerals 69, 133 and 134 denote a rubber cup (seal member), a thrust bearing and a stopper, respectively. The brake actuator 19 is provided with a hydraulic pressure detection chamber 150 as shown in FIG. The hydraulic pressure detection chamber 150 is connected to the second hydraulic chamber 24 </ b> B through an orifice 151.
Even if the pressure of 4B suddenly changes, the pressure shock is relieved and the hydraulic pressure of the hydraulic oil in the hydraulic pressure detection chamber 150 gradually rises.

The hydraulic pressure detecting chamber 150 is provided with a pressure switch 125 as a pressure detecting member. The pressure switch 125 is a sensor that detects when the hydraulic pressure in the hydraulic pressure detection chamber 150 exceeds a predetermined value and outputs an ON signal. In this case, the internal pressure of the hydraulic pressure detection chamber 150 is, for example, 70 Kg / When the voltage exceeds cm ² , an ON signal is output. Further, the pressure switch 125 has a hysteresis, and is turned off when the pressure drops to, for example, 50 kg / cm ² or less.

Here, the pressure switch 125 is connected to the controller 9 as control means. The motor 22 is also connected to the controller 9 via a relay box 160. And in the controller 9,
When the ON signal of the pressure switch 125 is detected, it is determined that the hydraulic pressure has been sufficiently increased by the brake actuator 19, and the operation of the motor 22 is stopped.

Therefore, when the motor 22 receives the control signal from the controller 9 and the piston 25 advances, the motor 22 is not driven unnecessarily, whereby the relay box 160 and the motor 22 are not driven.
Can be protected from overcurrent. That is, when the hydraulic pressure in the second hydraulic chamber 24B is sufficiently increased, unless the operation of the motor 22 is stopped immediately, an excessive current flows through the relay box 160 and the motor 22, and the relay box 160 and the motor 22 are damaged. It is conceivable that its function is impaired.
When the hydraulic pressure of the brake oil reaches a predetermined value, the operation of the motor 22 is stopped, thereby protecting the relay box 160 and the motor 22.

Incidentally, the brake actuator 1
9, a limit switch 126 is also provided, as shown in FIG. The limit switch 126 is provided to prevent the relay box 160 and the motor 22 from being damaged due to excessive rotation of the motor 22 when the piston 25 is retracted to the rear end, contrary to the above. When the nut 27 is retracted to a predetermined position, the sensor outputs an ON signal.

When an ON signal is output from the limit switch 126, the controller 9 stops the operation of the motor 22 based on the ON signal. Here, the limit switch 126
Mainly include a switch body 126A, a sensor rod (operating end of a limit switch) 126B, and a rod guide 126C.
It is composed of

As shown in FIG. 2, the contact portion of the nut 27 with the sensor rod 126B is formed on a surface inclined with respect to the axis of the piston 25, and the tip of the sensor rod 126B is formed on this surface. Are in contact with each other.
Therefore, when the nut 27 moves forward and backward, the tip of the sensor rod 126B slides on the inclined surface formed on the nut 27 and comes into contact with the sensor rod 126B, so that the sensor rod 126B moves in the vertical direction.

When the sensor rod 126B moves upward to a predetermined position, an ON signal is output. When the sensor rod 126B is below the predetermined position, the limit switch 126 is turned off. The limit switch 126 is connected to the hydraulic oil supply communication passage 1 when the stem of the valve 138 of the second valve mechanism 32 contacts the stopper bolt 137.
The on-signal is set to be output after the opening of the first communication port 42 without fail, so that the piston 25 stops after the first communication port 29 and the second communication port 30 communicate with each other. This is to ensure that the normal service brake is operated.

Thus, for example, when the nut 27 retreats with the rotation of the motor 22, an ON signal is output from the limit switch 126 at a predetermined retreat position, and the rotation of the motor 22 stops. Therefore, even though the nut 27 has already retracted to the rear end, the motor 22 does not try to rotate by receiving the power supply from the battery 68.
Thus, the motor 22 and the relay 160 can be protected from overcurrent.

FIGS. 2 and 3 show a state in which the nut 27 is located at the rear end and the piston 25 is in the initial position, and the sensor rod 126B is pushed upward to turn on the limit switch 126. It shows the state where it has become. When the nut 27 moves forward based on a control signal from the controller 9, the sensor switch 126B moves downward, and the limit switch 126 is turned off.

Now, the main part of the present invention will be described. As shown in FIG. 1, the first communication port 29 is provided with a first valve mechanism (first valve) 34. The operation of the one valve mechanism 34 causes the first communication port 29 and the first hydraulic chamber 2
The communication state with 4A is controlled. That is, as shown in FIG. 1, the first valve mechanism 34 includes a steel ball 34A as a valve body and a steel ball 34A.
A return spring 34B for urging A and the piston 2
5, a steel ball 34A is provided in the first communication port 29 and the first communication port 29.
It is arranged near the opening of a communication hole 29A provided between the hydraulic chamber 24A and the hydraulic chamber 24A.

The steel ball 34A is urged by the return spring 34B in a direction to close the opening of the communication hole 29A.
When the communication hole 29A is closed, the flow of the brake oil from the master cylinder 5 side (that is, the upper side in FIG. 1) to the first hydraulic chamber 24A is shut off. FIG.
As shown in FIG. 7, a rod 34C having a smaller diameter than the inner diameter of the communication hole 29A is inserted into the communication hole 29A, and the lower end of the rod 34C comes into contact with the outer peripheral surface of the piston 25. ing.

On the other hand, on the outer peripheral surface of the piston 25, an inclined surface 25B as shown in FIG.
When 5 moves, the lower end of the rod 34C comes into contact with the sliding surface 25B while sliding on the inclined surface 25B, and the rod 34C is driven in the vertical direction. That is, when the piston 25 is at the initial position, the lower end of the rod 34C is
5B. At this time, the upper end of the rod 34C contacts the steel ball 34A and the steel ball 34A.
Is driven upward.

In this case, when the rod 34C presses the steel ball 34A against the urging force of the return spring 34B, the first communication port 29 is opened, and the brake between the master cylinder 5 and the first hydraulic chamber 24A is braked. Oil flow will be allowed. Also, the piston 25
Is driven toward the second hydraulic chamber 24B, the rod 34C
Is driven downward along the inclined surface 25B while receiving the urging force of the return spring 34B.

In this case, the steel ball 34A is also driven downward by the urging force of the return spring 34B, whereby the opening of the first communication port 29 is closed. The reason why such a first valve mechanism 34 is provided in the brake actuator 19 is mainly for the following reason.

That is, as described above, when the vehicle 1 starts to move naturally due to the action of gravity or the like, for example, when the vehicle is parked on a slope without sufficiently pulling the parking brake lever, the parking brake safety device 60 is activated. This is for mechanically operating the rear wheel brake 3 by increasing the hydraulic pressure. In this case, if the piston 25 of the above-described brake actuator 19 is driven in the direction of the second hydraulic chamber 24B, the brake fluid pressure on the downstream side of the brake actuator 19 can be increased to apply a large braking force to the vehicle 1.

At this time, the brake oil is supplied to the rear wheel brake 3 and the second hydraulic chamber 24B by the second valve mechanism 32.
However, as described above, the second valve mechanism 32 is a one-way valve that shuts off the flow of the brake oil from the second hydraulic chamber 24B to the first hydraulic chamber 24A. It is not configured to block the flow of the brake oil from the first hydraulic chamber 24A to the second hydraulic chamber 24B. Therefore, when the driver depresses the brake pedal 4 during the operation of the parking brake safety device 60, the higher pressure is applied from the first hydraulic chamber 24A to the second hydraulic chamber 24B via the second valve mechanism 32. As a result, the brake fluid flows between the rear wheel brake 3 and the second hydraulic chamber 24B more than necessary.

In such a case, the parking brake safety device 6
When the zero operation is released, a large driving force is required to retreat the piston 25. However, if the driving force of the motor 22 is to be increased, the motor 22 becomes large, and the weight and cost increase. Therefore, by providing the first valve mechanism 34 as described above with the brake actuator 19,
When the parking brake safety device 60 is activated (that is, when the piston 2
5 is driven to the second hydraulic chamber 24B side by a predetermined amount).
The first communication port 29 is closed by the first valve mechanism 34 to prevent the brake oil from flowing from the master cylinder 5 side, and when the operation of the parking brake safety device 60 is released and the parking brake safety device 60 At the time of non-operation (that is, when the piston 25 is at the initial position), the first communication port 29 is opened to allow the communication of the brake oil between the master cylinder 5 and the rear wheel brake 3. It is.

Therefore, even if the brake pedal 4 is strongly depressed when the parking brake safety device 60 is operated, unnecessary increase of the brake fluid pressure on the wheel cylinder side can be prevented.
When the piston 25 is retracted, a large driving force is not required. This also makes it possible to suppress an increase in the size of the motor 22 and suppress an increase in weight and cost.

Although the motor 22 does not actually appear in the cross-sectional view shown in FIG. 2 (the motor 22 exists above the piston 25 in FIG. 2), In order to briefly explain the control system, the motor 22 is shown by a virtual line at a position different from the actual one. The brake actuator 19 is provided between the magnet valve 7 of the brake fluid pressure supply system 6 on the rear wheel side and the rear wheel brake 3 as shown in FIG. Predetermined amount piston 25
Is driven, the supply of the brake oil from the master cylinder 5 is cut off, and the hydraulic pressure of the brake oil sealed in the rear wheel brake 3 is increased.

Therefore, the brake actuator 19
The piston 25 sticks in a state in which the brake oil is sealed, or the motor 22 or the relay 16
If the vehicle 0 is damaged, the braking force may continue to act on the vehicle 1 and hinder normal driving. Therefore, in the brake actuator 19, in consideration of such a case, the piston drive shaft 131
Manual rotation input unit 172 capable of manually inputting a rotational force to the motor
And the manual rotation input section 172 is formed in a bolt shape.

When the above trouble occurs,
The manual rotation input section 172 is manually rotated by a jig or the like to retreat the piston 25 so that normal traveling can be performed. That is, as shown in FIGS. 2 to 5, a cover member (hereinafter referred to as a gear cover) 17 is provided at the end of the brake actuator 19 of the present invention.
0 is attached. The gear cover 170 is attached so as to cover the speed reduction mechanism 130, and protects the speed reduction mechanism 130 from dust, muddy water, and the like.

As shown in FIGS. 2 and 3, a manual rotation input section 172 provided at the rear end (right side in the figure) of the piston drive shaft 131 is formed so as to protrude from the gear cover 170. The manual rotation input section 172 is covered with a grommet (cap) 171 as shown in FIGS. The grommet 171 is formed by using a resin material having appropriate elasticity, and can be easily removed or attached to the gear cover 170.

The manual rotation input section 172 is provided in
As shown in FIG. 4 to FIG. 4, the cross-sectional shape is formed, for example, in a regular hexagon, and is configured as a bolt-like end similar to a normal bolt head. As a result, if the actuator 19 breaks down and the braking force remains applied, the driver removes the grommet 171 and exposes the manual rotation input unit 172.

Then, after fitting a tool such as a hexagon wrench or a dedicated jig to the manual rotation input portion 172, the piston drive shaft 131 is manually rotated to retreat the piston 25. As a result, the first communication port 29 and the second communication port 30 of the brake actuator 19 communicate with each other, thereby enabling normal traveling. (2) Description of Overall Configuration of Control System Next, the overall configuration of the control system of the slope start assist device 50 and the parking brake safety device 60 will be described with reference to FIG.

As shown in FIG. 7, the controller 9 as a control means controls the operation of the slope start assist device 50 for controlling the operation of the slope start assist device 50 and the operation of the parking brake safety device 60. And a parking brake safety device control means 61 are provided. Then, the slope start assist device control means 51 includes the operation start controller 5.
2, an operation release controller 53, an operation alarm controller 54, and drivers 55 and 56 are provided. The parking brake safety device control means 61 includes an operation start controller (first control means) 62 and an operation release controller (second control means). 63, timer (timer means) 65, driver 6
It has 6,67.

(2.1) Description of Control System of Slope Start Assist Device First, the hill start assist device control means 51 will be described.
A controller for controlling the start of the operation of the controller, an operation release controller 53 is a controller for controlling the release of the operation,
The operation alarm controller 54 is a control section for issuing an alarm for the operation.

Then, this slope start assist device control means 5
1 includes the magnet valve 7 and the alarm lamp 20 described above.
And the alarm buzzer 21 are connected, and the drivers 55, 5
The operation of the magnet valve 7, the alarm lamp 20, and the alarm buzzer 21 is controlled based on the control signal output from the controller 6.

That is, as shown in FIG. 7, the operation start controller 52 of the slope start assist device control means 51 includes:
Among the sensors 10 to 18 described above, the clutch sensor 1
2, a vehicle speed sensor 13, a neutral switch 14, and a stop lamp switch 15 are connected. When the following three vehicle states are detected by the respective sensors 12 to 15 in the operation start controller 52, the vehicle starts on a slope. A control signal for operating the device 50 is set.

1. When the stop lamp switch 15 detects that the brake pedal 4 has been depressed for a predetermined time (for example, 1 second) or more. 2. The vehicle speed = 0 by the vehicle speed sensor 13 (ie, the vehicle is stopped)
Is detected. 3. It is detected that the clutch pedal is depressed by the clutch sensor 12, or the neutral switch 1
4. When it is detected that the gear position is in the neutral position.

When all of the above three conditions (1) to (3) are satisfied, the operation start controller 52 determines that the driver is maintaining the vehicle 1 in a stopped state, and starts on a slope. A control signal for operating the auxiliary device 50 is set, and this control signal is output from the driver 55 to the magnet valve 7. As a result, the magnet valve 7 provided on the path of the front wheel side brake fluid pressure supply system 6 and the rear wheel side brake fluid pressure supply system 6 is turned on, and the brake fluid pressure is sealed. is there.

As described above, when the hill start assistance device 50 is operated, the vehicle 1 is stopped without stopping on the brake pedal 4 when stopping on a hill or stopping in a traffic jam. Fatigue is reduced. An operation switch 10 is also connected to the operation start controller 52. By turning off the operation switch,
The control signal set by the operation start controller 52 can be canceled.

On the other hand, a clutch sensor 12, a neutral switch 14, and a parking switch 16 are connected to the operation release controller 53. The operation release controller 53 is based on the detection information from the sensors 12, 14, and 16 described above. When any one of the following two states is detected, a control signal for canceling the operation of the slope start assist device 50 is set.

4. When the neutral switch 14 detects that the gear of the transmission has been operated to a position other than neutral, and when the clutch sensor 12 detects that the clutch pedal has been returned. 5. When the operation of the parking brake lever is detected by the parking switch 16.

In the case of the above item 4, the operation release controller 53 determines that the driver is about to start the vehicle 1 and sets a control signal for releasing the operation of the slope start assist device 50. In this case, the driver 55
This release signal is output to the magnet valve 7 from the controller. In the case of 5, since the vehicle 1 is stopped by the parking brake,
The operation release controller 53 determines that there is no need to stop the vehicle 1 by containing the brake fluid pressure, and sets a control signal for releasing the operation of the slope start assist device 50. In this case, when the other predetermined condition is satisfied, the above-described parking brake safety device 60 operates to surely keep the vehicle 1 in a stopped state. This case will be described later.

As described above, when any one of the above conditions 4 and 5 is satisfied, the operation release signal set by the operation release controller 53 is transmitted to the driver 55.
Is output to the magnet valve 7, whereby the magnet valve 7 is switched off. Therefore, when starting the vehicle 1, the driver can start the vehicle 1 by operating the accelerator pedal and the clutch pedal without operating the brake pedal 4, so that the driver particularly starts on a slope. Sometimes, the vehicle 1 can be easily started.

When the parking brake is actuated (case 5), the vehicle 1 is often stopped for a relatively long time. Therefore, the operation of the slope start assist device 50 is released to release the brake fluid. By releasing the brake oil in the pressure supply system 6 from the high pressure state, the service brake 2,
The unnecessary load on 3 has been eliminated. An adjustment switch 11 is also connected to the operation release controller 53. By operating the adjustment switch 11, the operation release timing of the slope start assist device 50 can be adjusted.

Next, the operation warning of the slope start assist device 50 will be described. The parking switch 16, the door switch 17, and the key switch 18 are connected to the operation release controller 53, and the operation of the slope start assist device 50 is in progress. When it is detected that the driver has performed any of the following operations, the controller 9 activates an alarm lamp 20 and an alarm buzzer 21 to warn the driver.

6. When the parking switch 16 and the door switch 17 detect that the door has been opened without pulling the parking brake lever. 7. When the stop of the engine is detected by the parking switch 16 and the key switch 18 without the parking brake lever being pulled. In the case of 6. above, the operation release controller 53 determines that the driver leaves the vehicle 1 without operating the parking brake, sets an alarm signal, and sets the alarm signal to the alarm lamp 20 and the alarm buzzer 21 from the driver 56. This warning signal is output. This activates the alarm lamp 20 and the alarm buzzer 21 to call the driver's attention.

In addition to the cases described in 6. and 7. above, when it is detected that an abnormality has occurred in the slope start assist device 50, the alarm lamp 20 and the alarm buzzer 21 are operated in the same manner as described above. , To alert the driver. In this manner, by providing the vehicle 1 with the slope start assist device 50, when the start and the stop are frequently repeated, the driver's fatigue can be greatly reduced.
It is possible to start the slope safely and reliably. (2.2) Explanation of the control system of the parking brake safety device

Next, the parking brake safety device control means 61
As described above, as described above, the parking brake safety device control means 61 includes the operation start controller 6
2, operation release controller 63, timer (timer means)
65, drivers 66 and 67 and power generation unit stopping means 16
It has five. The above-mentioned operation start controller 62 is a control unit for controlling the start of operation of the parking brake safety device 60, and the operation release controller 63 is a control unit for releasing the operation. Driver 6
Reference numerals 6 and 67 denote drive circuits, and power generation unit stopping means 165.
Is a control means for stopping the operation of the motor 22 of the brake actuator 19. The timer 65 will be described later.

As shown in FIG. 7, the parking brake safety device control means 61 is connected to a brake actuator (fluid pressure increasing mechanism) 19 and a parking brake lamp 33 which is turned on when the parking brake is actuated. The operation of the brake actuator 19 and the parking brake lamp 33 is controlled based on control signals output from the drivers 66 and 67.

Here, the parking brake safety device control means 6
The first operation start controller 62 will be described. This operation start controller 62 outputs a control signal for operating the parking brake safety device 60 when a predetermined vehicle speed is detected even though the parking brake is operating. To be set. More specifically, as shown in FIG. 7, a vehicle speed sensor 13, a neutral switch 14, a parking switch 16, a key switch 18, and a pressure switch 125 are connected to the operation start controller 62. When any of the following vehicle conditions of 8. and 9 is detected from the sensors 13, 14, 16, and 18, the brake actuator 19 is operated to increase the hydraulic pressure of the brake oil. .

8. Although the parking switch 16 has detected that the parking brake is operating, the vehicle speed sensor 13 detects the predetermined vehicle speed and the key switch 18 indicates that the engine is operating. When it is detected and the neutral switch 14 detects that the shift position is the neutral position. 9. When the vehicle speed sensor 13 detects a predetermined vehicle speed and the key switch 18 detects that the engine is not operating, even though the parking switch 16 detects that the parking brake is operating. .

In the cases of 8. and 9., the operation start controller 62 determines that the vehicle 1 has naturally started to move due to a slope such as a slope even though the vehicle is stopped by the parking brake. , The parking brake safety device 60 from the driver 66 to the brake actuator 19
Thus, a control signal for activating is output.

As a result, the brake actuator 19 provided on the path of the brake fluid pressure supply system 6 on the rear wheel side operates to increase the brake fluid pressure, increase the braking force of the vehicle 1, and stop the vehicle 1. It is like that. As described above, in the parking brake safety device 60, when the vehicle 1 starts moving naturally during parking on a slope or the like, the safety of the vehicle 1 during parking is ensured by activating the brake actuator 19 and increasing the brake fluid pressure. It is.

When the brake actuator 19 receives the control signal from the operation start controller 62, it rotates the motor 22 to advance the nut 27 and advance the piston 25. Thus, when the piston 25 advances by a predetermined amount, the second valve mechanism 32 causes the first communication port 2 to move forward.
9 and the second communication port 30 are shut off, the brake oil is filled, the hydraulic pressure rises, and the brake operates.

In this case, the first communication port 29 is closed by the first valve mechanism 34, so that the inflow of brake oil from the master cylinder 5 is prevented. Therefore, even if the brake pedal 4 is strongly depressed when the parking brake safety device 60 is actuated, the brake fluid pressure on the wheel cylinder side does not increase. The increase in cost can be suppressed.

Incidentally, as shown in FIG. 7, the parking brake safety device control means 61 includes a pressure switch 125.
A power generation unit stopping means 165 for outputting a signal for stopping the motor 22 when an ON signal is output from the power supply unit is provided. When the power generation unit stopping means 165 detects an ON signal from the pressure switch 125, it determines that the brake is sufficiently operated and outputs a signal for stopping the operation of the motor 22. 22 is
When the control signal is input, the operation stops.

Accordingly, even if the hydraulic pressure in the second hydraulic chamber 24B is sufficiently high, it is possible to prevent the motor 22 from rotating and the piston 25 from moving forward. This also allows the motor 22 and the relay 16
0 can be protected from overcurrent.
And the relay 160 can be prevented from being damaged.

Since the pressure switch 125 has a hysteresis, the pressure switch 125 turns off when the pressure (for example, 50 kg / cm ² ) becomes lower than the pressure at which the pressure switch 125 turns on (for example, 70 kg / cm ² ). However, when the parking brake safety device 60 is operating, when the brake oil hydraulic pressure decreases and the pressure switch 125 is turned off, the brake oil is repressurized until the pressure switch 125 outputs an ON signal again. It has become. Note that such re-pressurization is repeatedly performed.

Therefore, for example, even if the hydraulic pressure drops due to the temperature of the brake oil, which had become high immediately after parking, dropping over time and the volume shrinking, it is sufficient to perform re-pressurization in this manner even if the hydraulic pressure drops. It is possible to obtain a great braking force.

At this time, a signal for blinking the parking brake lamp 33 is output from the driver 67 to notify the driver that the parking brake safety device 60 is operating. In the case of 9 above,
If the engine is not operated by the key switch 18 and the brake actuator 19 is not operated, the timer 65 is triggered and the timer 65 starts counting.

When it is detected by the timer 65 that a predetermined time (for example, one hour) has elapsed while the vehicle 1 is stopped, the power switch 64 for the vehicle speed sensor is turned off in response to a time-up signal from the timer 65. As a result, the power supply to the vehicle speed sensor 13 is cut off. At this time, the system power switch 64A is turned off by a time-up signal from the timer 65.

As a result, the monitoring state of the vehicle 1 by the operation start controller 62 is released. In this case, the parking brake lamp 33 from the driver 67
Is also turned off to notify the driver that the operation of the parking brake safety device 60 has been turned off. When it is detected by the timer 65 that the stop state of the vehicle 1 has continued for a predetermined time since the engine was inactive, the power supply to the vehicle speed sensor 13 was cut off, and the parking brake safety was further reduced. The device control means 61 is turned off for the following reason.

That is, since the vehicle speed sensor 13 is an active vehicle speed sensor that always requires electric power, the battery may run out if the operation start controller 62 is kept on during long-time parking. It is. In addition, the vehicle 1 within a predetermined time set in advance.
If the start of the vehicle 1 is not detected, that is, if the stop state of the vehicle 1 is continued for one hour in this example, it is determined that the parking brake is sufficiently operated and the safety of the parking is secured. Because it is possible.

In the timer 65, while the engine is operated by the key switch 18, the timer 65 is reset by timer reset means (not shown). The operation start controller 62
The operation switch 10 is connected similarly to the operation start controller 52 of the slope start assist device control means 51. By turning off the operation switch, the control signal set by the operation start controller 62 is also transmitted. You can cancel it.

On the other hand, the parking brake safety device control means 61
The stop lamp switch 15, the parking switch 16 and the limit switch 126 are connected to the deactivation controller 63 of the deactivation controller 63.
Then, based on the detection information from each of the sensors 15 and 16, a control signal for releasing the operation of the parking brake safety device 60 is set when any one of the following vehicle conditions is detected. It is supposed to.

10. When the release operation of the parking brake lever is continuously detected by the parking switch 16 a predetermined plurality of times (for example, twice). 11. When the parking switch 16 detects the release operation of the parking brake lever and the stop lamp switch 15 detects the depression of the brake pedal (that is, the operation operation of the service brake).

That is, in order to activate the parking brake safety device 60, it is necessary to operate the parking brake as described in detail in Sections 8 and 9 above. The prerequisite is to release the parking brake as shown in Figs. As described above, when the operation release signal of the parking brake safety device 60 is set by the operation release controller 63, the motor 22 of the brake actuator 19 rotates in the direction opposite to the direction in which the parking brake safety device 60 operates, and the piston 25 To retreat.

When the piston 25 is retracted to a predetermined position, the first communication port 29 on the master cylinder 5 side communicates with the second communication port 30 on the brake operating member side by the second valve mechanism 32. When the piston 25 comes to the initial position,
The communication hole 29A of the first communication port 29 is opened by the first valve mechanism 34, whereby the first communication port 29 and the second communication port 3 are opened.
0 communicates with the normal brake operation.

When the piston 25 retreats to the predetermined position in this way, the limit switch 126 is turned on.
When the ON signal of the limit switch 126 is detected, it is determined that the piston 25 has fully retracted and a normal brake operation can be performed, and a signal for stopping the operation of the motor 22 is output.

Thus, since the operation of the motor 22 is stopped, the motor 22 is prevented from rotating even though the piston 25 has retreated to the rear end position. Therefore, the motor 22 and the relay 160 can be protected from overcurrent as in the case of pressurizing the brake oil, and damage to the motor 22 and the relay 160 can be prevented.

Here, the above-mentioned 10. will be described.
When the parking brake safety device 60 is released while the brake actuator 19 is operating to increase the brake fluid pressure, the parking brake release operation is continuously performed a plurality of times so that the driver consciously performs this operation. When it is performed, the parking brake safety device 60 is released.

That is, when the vehicle starts moving on a slope or the like, the parking brake safety device 60 operates to stop the vehicle instead of the parking brake.
It is preferable to activate the parking brake again.
Then, if the parking brake can be reliably operated by operating the parking brake again, it is desired to release the operation of the parking brake safety device 60.

However, in such a case, in order to operate the parking brake again, it is conceivable to first return the brake lever once and then pull the brake lever strongly again. Then, if the operation of the parking brake safety device 60 is released with the brake lever once returned in this way, the vehicle starts moving again. Therefore, in the parking brake safety device 60, in order to prevent this, the operation of the parking brake safety device 60 is not released only by the release of the parking brake operation, and the parking brake safety device 60 is operated again when the parking brake is activated again. The operation of the brake safety device 60 is released.

As a result, even if the driver unconsciously releases the parking brake, the brake actuator 19 does not operate to decrease the brake fluid pressure, and the safety of the vehicle 1 during parking is ensured. It is.

The vehicle speed is detected when the parking brake is operating and the engine is operating and the shift position is in the neutral position, or when the parking brake is operating and the engine is not operating. And actuator 1
The parking brake safety device 60 is brought into a standby state in which the parking brake 9 is actuated (8 and 9 above). In this standby state, while the vehicle speed is not detected, the parking brake is released by one release operation of the parking brake. The standby state of the brake safety device 60 is released, and normal traveling can be performed.

In the case of 11. above, the operation release controller 63 determines that the driver is about to start the vehicle 1 and releases the operation of the brake actuator 19. And these one
In the case of 0, 1 and 11, an operation release signal is set by the operation release controller 63, and the driver 66 outputs this operation release signal to the brake actuator 19. (2-3) Description of Fail Check Function By the way, the above-described parking brake safety device 60 is a so-called emergency device provided to stop the parked vehicle 1 when it starts moving, and is usually an emergency device. It rarely operates frequently when the vehicle is used.

As described above, the parking brake safety device 60
(That is, the brake actuator 1 as a main part thereof
If the opportunity for operation 9) is small, even if there is any abnormality in the brake actuator 19, it is difficult to detect the abnormality unless a periodic function check is performed.
If the brake actuator 19 has failed for any reason, it must be detected and reported to the occupant when the parking brake safety device 60 is to be activated (that is, because the parking brake is not effective enough). When the parked vehicle 1 starts moving), the vehicle cannot be stopped, and the reliability of the parking brake safety device 60 may be impaired.

On the other hand, as described above, the brake actuator 19 is provided with the two sensors 125 and 126, thereby protecting the relay 160 and the motor 22 from overcurrent.
The safety and reliability of the vehicle 1 can be further improved by performing the fail check using the above. Therefore, the controller 9 is also provided with a fail check function of automatically diagnosing the brake actuator 19 periodically (for example, about once a month) and detecting an abnormality of the brake actuator 19. I have.

That is, as shown in the table of FIG.
In the controller 9, the parking brake safety device control means 6
1 and the control signal by the slope start assist device control means 51, the clutch sensor 12, the stop lamp switch 1
5, based on the output signals from the pressure switch 125 and the limit switch 126, the following six fail checks are performed.

First, the parking brake safety device control means 61
As a result, the parking brake safety device 60 is in a non-operation state, and the clutch sensor 12 and the stop lamp
5, it is detected that neither the brake pedal 4 nor the clutch pedal is depressed. Further, when the slope start assist device 50 is not operated by the slope start assist device control means 51, You can check for the following failures:

That is, when the ON signal is output from the pressure switch 125 and the ON signal is also output from the limit switch 126 when the vehicle 1 is in such a state, the pressure switch 125 is It is considered that a failure has occurred, and a failure of the pressure switch 125 is detected. The pressure switch 12
5 outputs an ON signal, but when the limit switch 126 is OFF, for example, a failure of the driving portion of the motor 22 is considered, and a failure of the motor 22 or the relay 160 is detected.

Further, when both the pressure switch 125 and the limit switch 126 are off, disconnection of the limit switch 126 and the like are considered, and a failure of the limit switch 126 is detected. Next, regardless of the operation / non-operation of the parking brake safety device 60, when it is detected that neither the brake pedal 4 nor the clutch pedal is depressed, and the slope start assist device 50 is not operated, When the pressure switch 125 is off and the limit switch 126 outputs an on signal,
Again, a failure of the driving part of the motor 22 is considered, and a failure of the motor 22 or the relay 160 is detected.

When it is detected that the parking brake safety device 60 is operating and neither the brake pedal 4 nor the clutch pedal is depressed, and the slope start assist device 50 is not operating, the pressure Switch 1
When both 25 and the limit switch 126 are off,
Disconnection of limit switch 126 or brake fluid pressure supply system 6
In this case, a failure of the limit switch 126 or the brake fluid pressure supply system 6 is detected.

Finally, when it is detected that the parking brake safety device 60 is operating and neither the brake pedal 4 nor the clutch pedal is depressed, and the slope start assist device 50 is not operating, If both the pressure switch 125 and the limit switch 126 output an ON signal, the fixation of the limit switch 126 or the like is considered, and the failure of the limit switch 126 is detected.

As a result of the failure check detected in this way, when an abnormal part is detected, it is displayed on, for example, a display (not shown) provided in the meter panel. Note that such a fail check is performed by a fail check detecting unit (not shown) in the controller 9.

Since the brake actuator as one embodiment of the present invention is configured as described above, for example, the brake actuator 19 is operated according to the flowchart shown in FIG. 8 to operate the parking brake safety device 60. Let it. Here, the flowchart shown in FIG. 8 will be briefly described. First, when the stop of the vehicle 1 is detected by the vehicle speed sensor 13 in step S1, the process proceeds to step S2, and the operation of the parking brake is detected by the parking switch 16.

If it is detected in step S3 that the vehicle 1 has started moving by the vehicle speed sensor 13, it is determined in step S4 that the engine is operating by the key switch 18 and that the shift position is the neutral position by the neutral switch 14. Is satisfied, or the operation condition that the key switch 18 detects that the engine is not operating (the shift position of the transmission is arbitrary) is satisfied in step S5, the brake actuator is determined in step S6. Activate 19 to increase brake fluid pressure.

Then, in step S7, the rear wheel brake 3 is operated, and in step S8, the parking brake lamp 33 is operated to notify the driver of the operation of the parking brake safety device 60. FIG. 9 illustrates the operation of the brake actuator 19 when the parking brake safety device 60 operates. That is, when an operation signal is set to the brake actuator 19 by the operation start controller 62 and this signal is output from the driver 66, first, the motor 22 rotates and the nut 27 moves forward.

As a result, the nut 27 comes into contact with the piston 25, and the piston 25 moves forward, so that the volume of the second hydraulic chamber 24B is reduced. At this time, the first communication port 29 for connecting the hydraulic pressure supply system 6 on the master cylinder 5 side to the first hydraulic chamber 24A is provided.
Is closed by the first valve mechanism 34. That is, when the piston 25 advances by a predetermined amount, the rod 34C of the first valve mechanism 34 is driven downward along the inclined surface 25B of the piston 25. Then, the steel ball 34A is driven downward by the urging force of the return spring 34B, whereby the opening of the communication hole 29A connecting the first communication port 29 and the first hydraulic chamber 24A is closed.

Therefore, in this case, even if the driver steps on the brake pedal 4, the brake oil from the master cylinder 5 is not supplied to the rear wheel brake 3. When the piston 25 moves forward,
The communication path 142 that connects the first hydraulic chamber 24A and the second hydraulic chamber 24B is closed by the second valve mechanism 32. That is,
When the piston 25 advances by a predetermined amount, the stem of the valve 138 separates from the stopper bolt 137,
The valve 13 is actuated by the urging force of the return spring 141.
8, the communication passage 142 is closed, and the brake oil is not supplied.

As described above, the communication passage 142 is closed by the forward movement of the piston 25, and the volume of the second hydraulic chamber 24B is reduced, so that the brake actuator 19 and the brake operating member side in the brake fluid pressure supply system 6 are provided. And the hydraulic pressure between them increases, so that a larger braking force acts on the vehicle 1. Also, at this time, the first communication port 29 is also closed, which prevents the brake fluid pressure on the wheel cylinder side from increasing even if the driver depresses the brake pedal 4 carelessly when the parking brake safety device 60 operates. It is done.

After that, when the hydraulic pressure in the hydraulic pressure detection chamber 150 rises to a predetermined pressure, the pressure switch 125
Turns on. When the controller 9 detects the ON signal from the pressure switch 125, the power generation unit stop unit 165 outputs an operation stop signal of the motor 22 to cut off the power supply to the motor 22.

As a result, as shown in FIG. 13, by stopping the operation of the motor 22 before the hydraulic pressure increases sharply and the load on the motor 22 increases, an excessive load is not applied to the motor 22. , Motor 22 and relay 16
0 can be protected from overcurrent. In addition,
This pressure switch 125 has hysteresis,
When the brake oil hydraulic pressure decreases and the pressure switch 125 is turned off, the controller 9 again controls the pressure switch 1
The motor 22 is operated until the 25 outputs an ON signal to perform re-pressurization. Note that such re-pressurization is repeatedly performed.

Therefore, even when the hydraulic pressure decreases, a sufficient braking force can be obtained by performing such re-pressurization. At this time, the driver 67 outputs the parking brake lamp 3 as described above.
A signal for blinking 3 is output to notify the driver that the parking brake safety device 60 is operating.

FIG. 10 shows the operation of the brake actuator 19 when the operation of the parking brake safety device 60 is released.

That is, when an operation release signal is set to the brake actuator 19 by the operation release controller 62 and this signal is output from the driver 66, in the brake actuator 19, the motor 22 rotates in the reverse direction to move the nut 27 backward. As a result, the piston 25 retreats by the action of the hydraulic reaction force in the second hydraulic chamber 24B and the urging force of the return spring 31 disposed in the second hydraulic chamber 24B, and the piston 25 moves in the brake hydraulic pressure supply system 6. The hydraulic pressure between the brake actuator 19 and the brake operating member side decreases.

At this time, the first hydraulic chamber 24A and the second hydraulic
The state is in communication with the hydraulic chamber 24B. That is, when the piston 25 retreats to the predetermined position, the stem of the valve 138 comes into contact with the stopper bolt 137, the valve 138 moves against the urging force of the return spring 141, and the communication passage 142 is opened. At about the same time, the communication hole 29A is opened and the hydraulic pressure supply system 6 on the master cylinder 5 side is opened.
And the first hydraulic chamber 24A are in communication with each other. That is, when the piston 25 retreats to the initial position, the rod 34C of the first valve mechanism 34 is driven upward along the inclined surface 25B of the piston 25, and moves the teal ball 34A upward against the urging force of the return spring 34B. Drive.
Thus, the opening of the communication hole 29A is opened. Therefore, the brake fluid pressure of the rear wheel brake 3 to the brake operating member side is released, the braking force is not exerted, and the service brake is operated as usual.

When the nut 27 retreats with the rotation of the motor 22, the limit switch 126 outputs an ON signal at a predetermined retreat position after the communication passage 142 is opened. When the controller 9 detects the ON signal from the limit switch 126, the power generation unit stopping means 165 outputs an operation stop signal of the motor 22 to stop the operation of the motor 22.

As a result, even though the nut 27 is retracted to the rear end, the motor 22 does not rotate due to the supply of power from the battery 68, and as shown in FIG. The overcurrent does not flow through the relay 22 and the relay 160, and the motor 22 and the relay 160 can be protected. next,
The operation at the time of the fail check will be described with reference to FIG.
It will be something like shown below.

That is, when the brake actuator 19 fails, the brake actuator 1
9 is operated to pressurize the brake fluid pressure. At this time, the pressurized state of the second hydraulic chamber 24B is mainly checked based on the detection signal from the pressure switch 125 and the like. Next, the brake fluid pressure is reduced by rotating the motor 22 in the reverse direction. At this time, mainly the piston 25 is detected based on a detection signal from the limit switch 126 or the like.
The retreat is confirmed.

As described above, in the brake device using the brake actuator 19 of the present invention, the hill start assist device 50 is operated when the vehicle is temporarily stopped due to a signal waiting or traffic jam, so that the braking force can be reduced even when the brake pedal 4 is released. By maintaining it, it is possible to reduce driver fatigue,
In addition, the vehicle can easily start on a slope.

On the other hand, when the parking brake is operated and the vehicle 1 is parked and stopped, the engine is operating and the shift position is in the neutral position, or the engine is not operating and the shift position is arbitrary. Then, the parking brake safety device 60 operates. Thus, if the vehicle 1 starts to move even if no operation is performed on a slope or the like, the brake actuator 19 operates to increase the brake fluid pressure, thereby ensuring the safety of the vehicle 1 that is parked or stopped.

In this case, since the first communication port 29 is closed by the first valve mechanism 34 and the inflow of brake oil from the master cylinder 5 side is prevented, the driver is not operated when the parking brake safety device 60 is operated. However, even if the brake pedal 4 is inadvertently depressed, the brake fluid pressure downstream of the second hydraulic chamber 24B does not increase, so that the brake fluid pressure does not increase unnecessarily. Therefore, when the piston 25 is moved backward, a large driving force is not required, and an increase in the weight and cost of the brake actuator 19 can be suppressed.

The first valve mechanism 34 described above is connected to a steel ball 34A, a return spring 34B and a rod 34.
By using C or the like, a relatively simple and reliable valve mechanism can be provided. Furthermore, by making the first valve mechanism 34 have such a simple configuration, the first valve mechanism 34 can be disposed at the first communication port 29 relatively easily.

Further, by providing the piston 25 with the inclined surface 25B capable of driving the rod 34C, the first valve mechanism 3
4 can be made to correspond to the driving state of the piston 25, and there is also an advantage that the first valve mechanism 34 can be reliably opened and closed according to the operation of the parking brake safety device 60.

A hydraulic pressure detection chamber 150 is provided in the brake actuator 19, and the hydraulic pressure detection chamber 150
Since the pressure switch 125 for detecting the hydraulic pressure in the hydraulic chamber 24B is provided, the relay box 160 and the motor 2
2 can be protected from damage due to overcurrent or the like. That is, when the controller 9 detects the ON signal of the pressure switch 125, it determines that the brake actuator 19 has sufficiently increased the hydraulic pressure of the brake oil and stops the operation of the motor 22. It is no longer driven, so that the relay box 160 and the motor 22 can be protected from overcurrent.

After the brake actuator 19 pressurizes the brake oil, if the fluid pressure drops and the pressure switch 125 is turned off, the vehicle is pressurized again until the pressure switch 125 is turned on. Can be reliably stopped. Further, the brake actuator 19 is provided with a limit switch 126 so that the rotation of the motor 22 is stopped when the nut 27 retreats to a predetermined position. Regardless, the motor 22 does not try to rotate by receiving the power supply from the battery 68, and the motor 22 and the relay 1
60 can be protected from overcurrent.

Further, by providing such a pressure switch 125 and a limit switch 126, a fail check function can be easily added, and the reliability and safety of the parking brake safety device 60 can be further improved. become. By the way, even if the actuator 19 breaks down, a manual rotation input unit 172 capable of manually inputting a rotational force is connected to the piston 25 in an associated manner.
By manually rotating the manual rotation input section 172, the piston 25 can be retracted, and normal traveling can be performed.

That is, in such a case, the driver removed the grommet 171 to expose the manual rotation input section 172, and fitted a tool such as a hexagon wrench or a dedicated jig to the manual rotation input section 172. Thereafter, the piston 25 is retracted by manually rotating the piston drive shaft 131. Then, by this, the brake actuator 19
The first communication port 29 and the second communication port 30 communicate with each other to enable normal traveling.

When the parking brake safety device 60 operates when the engine is off, the timer 65 is triggered to start this counting. And this timer 65
When it is detected that a predetermined time (for example, one hour) has elapsed while the vehicle 1 is stopped, it is determined that the parking brake is sufficiently operated and parking safety is ensured, and the vehicle speed sensor power supply is determined. The switch 64 and the system power switch 64A are turned off, and the vehicle speed sensor 13 and the parking brake safety device control unit 61 are turned off. In this case, the blinking signal of the parking brake lamp 33 from the driver 67 is also turned off to notify the driver that the operation of the parking brake safety device 60 has been turned off.

Thus, unnecessary power consumption by the vehicle speed sensor 13 can be suppressed, and the battery can be prevented from running out. Further, in the timer 65, while the engine is being operated by the key switch 18, the timer 65 is reset by timer reset means (not shown), so that the predetermined time is reliably counted only when the engine becomes inoperative. be able to.

Further, when the parking brake safety device 60 operates, the parking brake lamp 33 blinks based on the output signal from the driver 67, so that the parking brake safety device 60 can reliably inform the driver of the operation. it can. The motor 22 is provided with load detecting means for detecting the load of the motor 22 in place of the pressure switch (pressure detecting member) 125, and when the load detected by the load detecting means exceeds a predetermined value, the motor 22 is stopped. Alternatively, a motor stopping means may be provided.

The brake actuator 19 does not necessarily need to be provided in the brake fluid pressure supply system 6 on the rear wheel side, but may be provided in the brake fluid pressure supply system 6 on the front wheel side, for example. Furthermore, the front wheel brake actuator and the rear wheel brake actuator that are independently configured may be provided in the brake fluid pressure supply system 6 on the front wheel side and the rear wheel side, respectively. With such a configuration, safety during parking of the vehicle can be more reliably ensured.

As a sensor for detecting the retreat of the moving member (nut) 27, the limit switch 126 used in the above embodiment is advantageous in terms of cost and reliability. Or a non-contact sensor such as a photoelectric sensor or a magnetic sensor.

[0169]

As described in detail above, according to the brake actuator of the present invention, the first connection port connected to the master cylinder and the second connection port connected to the wheel cylinder are provided. A piston, which is slidably inserted into the cylinder and separates the interior of the cylinder into a first chamber communicating with the first connection port and a second chamber communicating with the second connection port; A communication passage connecting the first chamber and the second chamber is urged from the master cylinder side in a direction to close the first connection port, and an initial position of the piston is set at an initial position from the master cylinder side. A first valve configured to open the first connection port against a biasing force and close the first connection port by the biasing force when the piston is displaced toward the second chamber; Close the communication passage from the room side At the initial position of the piston, opens the communication passage against the urging force from the second chamber side, and when the piston is displaced toward the second chamber side, the urging force is applied. A second valve configured to close the communication path, and a driving unit that increases the pressure of the wheel cylinder by displacing the piston from the initial position toward the second chamber, When the driving means drives the piston from the initial position, the first connection port is closed and the inflow of brake oil from the master cylinder side is prevented. This prevents the brake fluid pressure on the wheel cylinder side from rising more than the second chamber, thereby preventing the brake fluid pressure from unnecessarily increasing. Thus, there is an advantage that a large driving force is not required when the piston is moved backward, and an increase in the weight and cost of the driving means can be suppressed, and an increase in the weight and cost of the entire brake actuator can be suppressed.

According to a second aspect of the present invention, in addition to the structure of the first aspect, the first valve can close the first connection port, and the valve can be closed. A return spring that urges the body from the master cylinder side, and a rod interposed between the valve body and the outer periphery of the piston in the first connection port. By forming the outer periphery of the piston in such a shape as to press the valve body in the opening direction via the valve body, a valve mechanism with a relatively simple configuration and reliable operation can be provided. Thus, there is an advantage that cost and weight increase can be suppressed as much as possible. In addition, since the first valve has such a simple configuration, the first valve can be relatively easily disposed at the first connection port. Furthermore, since the opening / closing state of the first valve can be made to correspond to the driving state of the piston, there is an advantage that the first valve can be opened and closed reliably according to the operation of the brake actuator.

According to a third aspect of the present invention, in addition to the structure of the first or second aspect, a control means for controlling the operation of the driving means is provided. And detecting the movement of the vehicle while the parking brake is operating, by operating the driving means to displace the piston toward the second chamber, thereby enhancing the safety of the parked and parked vehicle. be able to.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing a main part configuration of a brake actuator as one embodiment of the present invention, and is a partially enlarged view in FIG.

FIG. 2 is a schematic cross-sectional view showing a configuration of a main part of a brake actuator as one embodiment of the present invention, and FIG. 2 is a cross-sectional view along AA in FIG.

FIG. 3 is a schematic cross-sectional view illustrating a configuration of a main part of a brake actuator as one embodiment of the present invention.

FIG. 4 is a schematic configuration diagram showing an outer shape of a brake actuator as one embodiment of the present invention, and is a view as seen in the direction of arrow B in FIG. 2;

5 is a schematic configuration diagram showing an outer shape of a brake actuator as one embodiment of the present invention, and is a view as seen in the direction of arrow C in FIG. 3;

FIG. 6 is a schematic diagram showing an overall configuration of a vehicle using a brake actuator as one embodiment of the present invention.

FIG. 7 is a schematic control block diagram illustrating an overall configuration of a control system in a brake actuator as one embodiment of the present invention.

FIG. 8 is a flowchart for simply explaining the operation of a brake actuator as one embodiment of the present invention.

FIG. 9 is a diagram for briefly explaining the operation of a brake actuator as one embodiment of the present invention.

FIG. 10 is a diagram for briefly explaining an operation release operation of the brake actuator as one embodiment of the present invention.

FIG. 11 is a diagram for explaining an operation at the time of a fail check of the brake actuator as one embodiment of the present invention.

FIG. 12 is a diagram illustrating items of a fail check of a brake actuator as one embodiment of the present invention.

FIG. 13 is a graph for explaining the operation of the brake actuator as one embodiment of the present invention, and is a graph showing changes in the hydraulic pressure of the working fluid and the current of the motor when the piston of the brake actuator advances.

FIG. 14 is a graph for explaining the operation of the brake actuator as one embodiment of the present invention, and is a graph showing changes in the hydraulic pressure of the working fluid and the motor current when the piston of the brake actuator is retracted.

FIG. 15 is a schematic cross-sectional view showing a configuration of a main part of a brake actuator conceived in the process of creating the present invention.

[Explanation of symbols]

Reference Signs List 1 vehicle 2 front wheel brake (front wheel brake) 3 rear wheel brake (rear wheel brake) 4 brake pedal (service brake operating member) 5 master cylinder 6 brake fluid pressure supply system (incompressible fluid supply system for brake operation) 7 switching valve (magnet valve) 8 LSV (load sensing valve) 9 controller as control means 10 operation switch 11 adjustment switch 12 clutch pedal stroke sensor (or clutch sensor) 13 vehicle speed sensor (vehicle speed detection means) 14 neutral switch (speed change) Position detecting means) 15 Stop lamp switch (Service brake operating member operating state detecting means) 16 Parking switch (Parking brake operating state detecting means) 17 Door switch 18 Key switch (Engine operating state detection) Step) 19 Brake actuator 20 Alarm lamp 21 Alarm buzzer 22 Motor or electric motor as drive means (actuator) 23 Casing (actuator housing) 23A Space (cylinder) 24 Hydraulic chamber 24A First hydraulic chamber (first chamber) ) 24B Second hydraulic chamber (second chamber) 25 Piston (pressure increasing member or piston member) 25A Communication hole 25B Inclined surface 27 Nut as moving member 28 Screw mechanism 29 First communication port (first connection port) 29A Communication hole Reference Signs List 30 second communication port (second connection port) 31 return spring 32 second valve mechanism (second valve) 33 parking brake lamp 34 first valve mechanism (first valve) 34A steel ball as valve body 34B return spring 34C rod 50 Slope Start Assist Device 51 Slope Start Assist Device Control Means 52 Operation Start controller 53 Operation release controller 54 Operation alarm controller 55, 56 Driver 60 Parking brake safety device 61 Parking brake safety device control means 62 Operation start controller (first control means) 63 Operation release controller (second control means) 64 For vehicle speed sensor Power cutoff switch 64A System power switch 65 Timer means 66, 67 Driver 68 Battery 69 Rubber cup (seal member) 125 Pressure switch (pressure detection member) 126 Limit switch 126A Switch body 126B Sensor rod (operating end of limit switch) 126C Rod Guide 130 Reduction mechanism (or rotational force transmission mechanism) 130A Pinion gear 130B Driven gear 131 Piston drive shaft 131A Male screw 132 Gear pin 133 Thrust Alling 134 Stopper 135 Depressed portion 136 Sleeve 137 Stopper bolt 138 Valve 139 Elongated hole 140 Space 141 Return spring 142 Hydraulic oil supply communication passage 150 Hydraulic pressure detection chamber 151 Orifice 160 Relay 165 Power generation unit stop means 170 Cover member (gear cover) ) 171 Grommet (cap) 172 Manual rotation input section (bolt end)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-121963 (JP, A) JP-A-8-198094 (JP, A) JP-A 8-216869 (JP, A) JP-A-2- 296565 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B60T 13/00 B60T 8/00

Claims (3)

(57) [Claims] 1. A cylinder having a first connection port connected to a master cylinder and a second connection port connected to a wheel cylinder, and a first port slidably inserted into the cylinder and the first port passing through the cylinder. A piston separating a first chamber communicating with the connection port and a second chamber communicating with the second connection port, a communication path communicating the first chamber with the second chamber, The first connection port is urged in a direction to close the first connection port, and at the initial position of the piston, the first connection port is opened against the urging force from the master cylinder side to open the first connection port on the second chamber side. A first valve configured to close the first connection port by the urging force when the piston is displaced, and a first valve that is urged from the second chamber side in a direction to close the communication passage, The position is from the second room A second valve configured to open the communication passage against the force and close the communication passage by the urging force when the piston is displaced toward the second chamber; and moving the piston from the initial position. A brake actuator, comprising: driving means for increasing the pressure of the wheel cylinder by displacing the wheel cylinder toward the second chamber. 2. A valve body in which the first valve can close a first connection port, a return spring for urging the valve body from a master cylinder side, and the valve body and the piston in the first connection port. The piston has an outer periphery formed in such a shape as to press the valve body in the opening direction via the rod in an initial state of the piston. The brake actuator according to claim 1, wherein: 3. A control means for controlling the operation of the driving means, wherein the control means, when detecting that the vehicle has moved during the operation of the parking brake, displaces the piston toward the second chamber. The brake actuator according to claim 1, wherein the brake actuator is configured to operate the driving unit.