JPH0256264B2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a braking force retention device for a vehicle.

(Problems to be solved by the prior art and the invention) For example, in today's automatic cars, when stopping at a traffic light, etc., it is necessary to brake due to the creep phenomenon or change the shift range to neutral or parking at low speeds. I move forward.

Conventionally, a type of system that seals the brake fluid has been proposed as a countermeasure to the above problem, but with this method, once the brake pedal is depressed, the position where the fluid pressure rises in the piston stroke of the master cylinder moves and the brake fluid is trapped inside the hole leading to the reservoir. The cup will pass through with it inflated. Therefore, there was a problem that the swollen cup was damaged.

In addition, there was a conventional braking force retention device for vehicles that prevents the brake pedal from being depressed again by energizing an electromagnet and attracting an adsorption plate when the brake is applied and stopped for about 2 seconds.
This is proposed in Publication No. 7100, etc. With this device, if the brake force is insufficient after the first depression, even if you try to apply the brakes again, the brake pedal is fixed and cannot be depressed again, so you can de-energize the electromagnet by depressing the accelerator pedal. The brakes cannot be reapplied unless the switch is activated or another signal is applied. If the brake is applied again while the electromagnet is still energized, the adsorption plate that is attracted to the electromagnet will slip, but if this situation is repeated, the adsorption plate will become severely worn out, which is not desirable.

Therefore, the technical object of the present invention is to solve the above-mentioned conventional problems by using a spring-type one-way brake in a braking force holding device for a vehicle.

[Structure of the invention]

(Means for solving the problem) The means taken to solve the above-mentioned technical problem is that the braking force holding device is rotatably supported on the vehicle body, and as the vehicle body rotates, the brake force is applied to the service brake system of the vehicle. A rack gear fixed to a brake pedal capable of operating a master cylinder, a pinion gear that is constantly meshed with the rack gear and rotates as the brake pedal rotates, and a rotating member that is pivotally supported on the vehicle body so as to be rotatable integrally with the pinion gear. , a coil portion having one end fixed to the vehicle body and the other end free, and having an inner diameter larger than an outer diameter of the circumferential surface of the rotating member and loosely fitted on the circumferential surface of the rotating member; By displacing the end, the inner diameter of the coil portion changes and frictionally engages with the circumferential surface of the rotating member, and under this frictional engagement, rotation of the rotating member is allowed as the brake pedal is depressed. However, when the rotating member attempts to rotate in the opposite direction, a spring member is wound around the rotating member to prevent the rotating member from rotating in the opposite direction, an electric motor is fixed to the vehicle body, and the spring member is slidably supported by the vehicle body. and an electric actuator comprising a sliding member that locks the other end of the spring member and slides in response to rotation of the electric motor to displace the other end of the spring member.

(Operations and Effects of the Invention) According to the above configuration, the other end of the spring member is normally in a free state, and the coil portion is not frictionally engaged with the circumferential surface of the rotating member, allowing the rotating member to freely rotate. Brake pedal is not held. When trying to maintain the braking force, the electric actuator is activated to drive the electric motor, and as the electric motor rotates, the sliding member slides, displacing the other end of the spring member and reducing the inner diameter of the coil part. The brake pedal is frictionally engaged with the circumferential surface of the rotating member to prevent the rotating member from rotating in the opposite direction, thereby holding the brake pedal in the depressed position. Therefore, if the electric actuator is activated when the vehicle is stopped and causes the sliding member to slide in response to the rotation of the electric motor, displacing the other end of the spring member, the brake pedal can be depressed when the vehicle is stopped. The braking force can be maintained in a continuous state, and the brake pedal can be depressed again without difficulty.

Further, according to the above structure, there is no risk of damaging the cup of the master cylinder, and there is no need for an intermediate hub as in the prior art, and the structure is very simple and can be manufactured at low cost. In addition, since the pedal is held by the self-leading action (one-way clutch action) of the spring member, the rotating member whose speed is increased by the rack gear and pinion gear and whose rotational torque is reduced is held, so the tightening force of the holding spring member against the rotating member is may be small, thereby making it possible to reduce the driving force of the electric motor of the electric actuator, thereby making it possible to downsize the electric actuator.

Furthermore, according to the above configuration, the coil portion of the spring member has an inner diameter larger than an outer diameter of the circumferential surface of the rotating member. Therefore, the inner diameter of the coil portion of the spring member is made smaller than the outer diameter of the circumferential surface of the rotating member, so that the tightening force against the circumferential surface of the rotating member is increased by the rotation of the rotating member due to the return operation of the pedal. A braking force retention system in which the spring member is wound around the circumferential surface of a rotating member with a tightening force, and when the pedal is released, the free end of the spring member is displaced in the direction in which the inner diameter of the coil part expands by a release mechanism. In the device (Japanese Patent Application No. 57-86918), if the control unit that controls the operation of the release mechanism fails, the pedal cannot be released, and if this occurs while the vehicle is running, running stability will be impaired. In contrast, with the present invention, even if the control unit that controls the operation of the electric actuator fails, the braking force retention function is lost, but the depressing and returning of the brake pedal is ensured, resulting in stable driving. It maintains its properties and is highly safe.

(Example) Hereinafter, an example of a braking force holding device for a vehicle according to the present invention will be described based on the drawings.

In Figs. 1 to 3, 1 is a brake pedal, which is rotatably supported on a bracket 2 fixed to the vehicle body about a pin 3. When the pedal 1 is depressed, a push rod 4 activates the brake master cylinder M. The piston is pushed and braking force is generated.

Reference numeral 5 denotes a rack gear fixed to the brake pedal 1 with bolts 7, teeth 8 are provided at the lower edge of the central window, and a pinion gear 9 meshes with the teeth 8. The pinion gear 9 is provided so as to rotate integrally on a shaft 11 that rotatably passes through a bracket 10 fixed to the bracket 2 with a bolt 6. A rotating member 12 located on the opposite side of the pinion gear 9 of the bracket 10 is also provided on the shaft 11 so as to rotate therewith. A spring member 13 is arranged on the outer peripheral side of the rotating member 12. This spring member 13 has a coil portion 13a to be frictionally engaged with the circumferential surface 12a of the rotating member 12, one end 13b fixed on the bracket 10 by a fixing plate 14 welded to the bracket 10, and the other free end 13c. have. In the free state of the spring member 13, the inner diameter of the coil portion 13a is slightly larger than the outer diameter of the circumferential surface 12a of the rotating member 12. A retainer 15 is provided on the shaft 11 to prevent the spring member 13 from coming off. 16 and 17 are washers.

The coil portion 13a of the spring member 13 has the other end 1
3c is pushed toward the upper left in FIG. 1 to reduce its diameter and frictionally engage with the circumferential surface 12a of the rotating member 12. Under this state of frictional engagement, when the rotating member 12 attempts to rotate counterclockwise in FIG. 1, the frictional force between the coil portion 13a and the rotating member 12 acts to reduce the diameter of the coil portion 13a. As a result, the coil portion 13a is wound around the rotating member 12, thereby preventing the rotating member 12 from rotating in the counterclockwise direction in FIG. On the contrary, when the rotating member 12 tries to rotate clockwise in FIG.
Therefore, the coil portion 13a does not wrap around the rotating member 12 and the coil portion 13a expands the diameter of the rotating member 12.
can rotate.

Reference numeral 18 denotes an electric actuator for pushing the other end 13c of the spring member 13, which is connected to an electric motor 19 fixed to the bracket 10 and
It consists of a sliding member 21 with a rack, which is a sliding member according to the present invention, which is slidably supported by a bracket 20 fixed at 0. The rack 21a of the sliding member 21 meshes with a pinion gear 22 fixed to the rotating shaft of the electric motor 19, and the forked head 21b of the sliding member 21 engages the bent portion 13d of the other end 13c of the spring member 13. Stop. A spring 24 is interposed between the retainer 23 attached to the sliding member 21 and the bracket 20, and urges the sliding member 21 toward the lower right in FIG.

The operation of this embodiment having the above configuration will be explained.

When the brake pedal 1 is depressed, the brake pedal 1 rotates clockwise about the pin 3 in FIG. 1, operating the brake master cylinder M via the push rod 4 to generate braking force. At the same time, the rack gear 5 fixed to the brake pedal 1 rotates about the pin 3, and its teeth 8
The pinion gear 9 that meshes with the pinion gear 9 and this pinion gear 9
A rotating member 12 integrated with the rotating member 12 rotates clockwise in FIG.

When the brake pedal 1 is depressed as described above, when the vehicle speed becomes lower than the set vehicle speed, the electric motor 1 of the electric actuator 18 is activated by a control section (not shown).
9 is rotated counterclockwise in FIG. 3, the sliding member 21 having the rack gear 21a that meshes with the pinion gear 22 is slid toward the upper left in FIG. 1, and the other end 13c of the spring member 13 thereby With this displacement, the coil portion 13a frictionally engages with the circumferential surface 12a of the rotating member 12. When the brake pedal 1 is no longer depressed, the brake pedal 1 attempts to return due to the return spring, and the rotating member 12 attempts to rotate counterclockwise in FIG. Since the coil portion 13a is wound around the rotating member 12 and prevents the rotating member 12 from rotating in the counterclockwise direction, the brake pedal 1 is held in the depressed position and the braking force is maintained. At this time, if the brake pedal 1 is not depressed enough and the vehicle moves forward or backward at low speed, the fixed brake pedal 1 may be depressed again. At this time, the rotating member 12
rotates clockwise in FIG. 1, and then when the depression force on the brake pedal 1 is released, the rotating member 12 attempts to rotate counterclockwise in FIG. 1 again, but this rotation is blocked. brake pedal 1
is fixed at the re-depression position, and the braking force is maintained.

Next, in response to depression of the accelerator pedal at the time of starting, a control section (not shown) releases the operation of the electric motor 19, and the sliding member 21 is returned to the position shown in FIG. 1 by the force of the return spring 24. As a result, the diameter of the coil portion 13a of the spring member 13 expands and separates from the circumferential surface 12a of the rotating member 12, allowing the rotating member 12 to rotate in the counterclockwise direction in FIG. , the braking force is released.

An embodiment of the present invention has been described above, but each part of the embodiment can be modified as appropriate within the scope of the claims.

[Brief explanation of the drawing]

FIG. 1 is a front view of an embodiment of a braking force holding device for a vehicle according to the present invention, FIG. 2 is a sectional view taken along the line -- in FIG. 1, and FIG. 3 is a directional view of FIG. 1... Brake pedal, 5... Rack gear, 9
...Pinion gear, 10...Bracket, 12...
...Rotating member, 13... Spring member, 13a...
...Coil part, 18...Electric actuator, 1
9...Electric motor, 21...Sliding member with rack (sliding member).

Claims (1)

[Claims] 1. A rack gear fixed to a brake pedal that is rotatably supported on the vehicle body and can actuate a brake master cylinder of a service brake system of the vehicle as the vehicle body rotates; A rotating pinion gear, a rotating member pivotally supported on a vehicle body so as to be rotatable integrally with the pinion gear, one end fixed to the vehicle body and the other end free, and having an inner diameter larger than an outer diameter of a surrounding surface of the rotating member. and has a coil portion that is loosely fitted onto the circumferential surface of the rotating member, and by displacing the other end, the inner diameter of the coil portion changes and frictionally engages with the circumferential surface of the rotating member. Under frictional engagement, the rotating member is allowed to rotate as the brake pedal is depressed, but when the rotating member attempts to rotate in the opposite direction, it wraps around the rotating member and prevents the rotating member from rotating in the opposite direction. a blocking spring member; an electric motor fixed to the vehicle body; and a motor slidably supported by the vehicle body to lock the other end of the spring member and sliding in response to rotation of the electric motor to lock the other end of the spring member. A braking force retention device for a vehicle, comprising an electric actuator made of a sliding member for displacement.