JPH0810061Y2 - Parking brake device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a parking brake device, and more particularly to an improvement of a toggle type parking brake device that guarantees complete input retention.

[Prior Art] In general, an input mechanism of a vehicle parking brake device is of a type that mainly holds an input by a ratchet structure. However, such an input mechanism has a dislike that the braking force varies depending on the pulling operation force of the parking lever and the stable braking effect cannot always be expected.
Especially for industrial vehicles such as forklifts, where the vehicle weight is comparatively heavy, it is necessary to give more consideration to braking failure accidents that tend to occur when parking on slopes. Has been adopted.

FIG. 3 exemplifies the toggle type parking brake device, in which a long hole 14 is formed on a frame 12 fixed to a front portion 10 of a vehicle body, and a guide inserted in the long hole 14 is inserted. Pin 16
An end of a cable 20 connected to the brake main body is engaged with the hook 18 which is guided and linearly moved. The toggle mechanism that strongly pulls the cable 20 that interlocks via the hook 18 includes a parking lever 24 pivotally attached to a point on the base 12 on the extension of the elongated hole 14 by a pin 22 so as to be rotatable. Midpoint of parking lever 24 and above hook 18
And a guide plate 16 of a link plate 26 for articulating the parking lever 24, and a set (rearward tilt) position slightly beyond a dead position D of the toggle mechanism from a release (forward tilt) position C of the parking lever 24 shown by a chain line. By rotating to S, the cable 20 is pulled through the link plate 26 and the hook 18,
The brake main body is configured to operate.

In addition, in order to adjust the play of the brake operation system caused by the play of the cable 20 and the wear of each functional part,
Generally, the parking lever 24 is formed in a hollow cylindrical shape,
One end of the link plate 26 is connected to a slider 28 fitted in the hollow cylinder by a pin 30, and the slider 28 is inserted into the hollow cylinder from the upper end of the knob of the parking lever 24. It is screwed to the end of the rod 32. Therefore, by rotating the head portion 32a of the adjusting rod 32 and finely moving the slider 28 together with the pin 30, the link plate 26 that articulates.
The position of the hook 18 is adjusted via to absorb excessive play of the brake operating system.

[Problems to be Solved by the Invention] As described above, the toggle type parking brake device has an advantage that a stable braking force can be always secured by rotating the parking lever 24 to the set position S. However, the input holding in the parking brake device depends only on the rotational moment to the braking side that acts on the parking lever 24 based on the pulling reaction force from the stage of exceeding the dead center position D. Therefore, when an external force is applied to the parking lever 24 due to the driver's negligence or an unexpected factor, and the parking lever 24 is moved to the release side beyond the dead center position D, the pulling reaction force causes the parking lever 24 to automatically move. Floating to the release side may continue and a serious accident may be caused due to unexpected release of braking.

SUMMARY OF THE INVENTION The present invention has as its technical problem to be solved the achievement of reliable input holding by providing a simple stop mechanism.

[Means for Solving the Problems] In order to solve the above problems, the present invention constantly advances into the rotation locus of the parking lever on a pedestal that pivotally supports the parking lever by a spring bias, and The braking mechanism is equipped with a braking mechanism that is driven and retracted only by the rotation interference to the braking side, and an electromagnetic unit that forcibly retracts the braking force by energizing through a manual switch.
A new configuration is adopted in which the parking stop position of the parking lever to the release side by the advance stop piece is set to the braking side rather than the dead center position of the toggle mechanism.

In a preferred form of the present invention, the manual switch (button switch) is provided on a knob of a parking lever, and its operation direction is set to be a direction orthogonal to a plane including a turning locus of the lever. The manual switch can be arranged on the spokes of the steering wheel.

[Operation] When the parking lever of this device is pulled and rotated from the release position to the braking side during parking, the stop piece that is always in the turning trajectory resists the biasing force of the spring due to the turning interference. Then, the driven lever is retracted, and the parking lever is allowed to move to the set position at the end on the braking side. Of course, after passing through the parking lever, the stopper immediately returns to the advanced state by the urging force of the spring, and prevents the parking lever from excessively moving toward the release side.

In other words, even if an external force that urges the parking lever toward the release side is added for some reason after the parking brake is activated, the rotation is reliably stopped by the advancing stop piece, and the rotation stop position is the dead point of the toggle mechanism. Since it is set to the braking side rather than the position, if the temporarily applied external force is erased, the rotation moment based on the traction reaction force acts in the direction to pull the parking lever back to the set position, and the original stable Transition to input hold posture. When releasing the parking brake, the blocking piece is forcibly retracted from the turning locus by the electromagnetic attraction force through the preceding operation of the manual switch, so the parking lever is quickly released by normal turning operation. Can be returned to the position.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. The same components as those of the conventional parking brake device are designated by the same reference numerals as those in FIG. 3, and detailed description thereof will be omitted.

In the figure, 42 is a frame fixed to the front part 10 of the vehicle body,
The parking lever 24 is a pin 22 on the confronting twin wall 42a of the mount 42.
A cable 20 which is rotatably supported by the parking lever 24 and is connected to the parking lever 24 through a toggle mechanism having the same structure shown in FIG. 3 is connected to a main body of a brake mechanism (not shown). A mounting seat 42b protruding upward is formed on one of the facing double walls 42a of the gantry 42, and a stopping mechanism 50, which is a feature of the present invention, is installed on an outer surface of the mounting seat 42b.

The restraint mechanism 50 has a housing 51 directly fixed to the mounting seat 42b, and a restraining piece 53 is slidably fitted in a square hole 52 provided from the housing 51 through the mounting seat 42b. Has been inserted. The restraining piece 53 is constantly urged in the forward direction by a spring 54, and in the most advanced state regulated by the protrusion 53a, its tip advances into the turning locus L of the parking lever 24, and its tip surface 53b. Is the release side of the parking lever 24 (second
It is inclined to retreat toward the upper side in the figure).
That is, with respect to the rotational interference of the parking lever 24 toward the braking side (downward in FIG. 2), the stopping piece 53 smoothly follows the urging force of the spring 54 by the component force acting on the front end surface 53b. On the other hand, the parking lever 24 is retracted, and on the other hand, the rotation interference to the release side is reliably resisted to prevent the parking lever 24 from moving excessively. And the parking lever 24 by the stop piece 53 that has advanced
The rotation stop position of is set to the same as the dead center position D of the toggle mechanism shown in FIG. 1 or somewhat to the braking side, and is determined by the interference between the link plate 26 and a positioning piece (not shown). A play stroke G is interposed between the 24 set positions S.

Further, an electromagnet 55 for forcibly attracting and retracting the stopper piece 53 made of a ferromagnetic material is incorporated at the outer end of the square hole of the housing 51 to form an electromagnetic unit including the housing 51. The electromagnetic unit is connected to a power source (not shown) via a harness 56, and a button switch 57 mounted on the knob 24a.
Is also connected. The button switch 57 rotates the locus L of the parking lever 24 so that when an external force directed in the releasing direction is applied to the parking lever 24 at the set position S, the button switch 57 is not simultaneously activated by the external force.
The operation direction is set in the direction orthogonal to the plane including. The installation position of the button switch 57 is the knob.
Not limited to 24a, it may be provided, for example, on the spokes of the steering wheel. In short, it is preferable to select a location that is less likely to cause unexpected interference and has excellent operability.

The present invention is configured as described above, and the parking lever in the release position C is used to activate the parking brake.
When the 24 is pulled and rotated toward the braking side, the stop piece 53 is always in the state of advancing into the rotation locus L by the urging force of the spring 54.
Due to the component force acting on the front end surface 53b of the parking lever 24 due to the interference with the parking lever 24, it smoothly retracts into the housing 51 against the biasing force of the spring 54, and the parking lever 24 brakes. It is allowed to move to the set position S at the side end. As a result, the cable 20 linked via the toggle mechanism is pulled, and the parking brake is normally activated. Immediately after the parking lever 24 passes, the restraining piece 53 returns to the advanced state again by the urging force of the spring 54 and secures the restraining posture here.

Therefore, after the parking brake is activated, even if an external force for urging the parking brake is applied to the parking lever 24 due to the driver's fault or an unexpected factor, the rotation locus L
The excessive movement is surely stopped by the obstruction of the stop piece 53 that has advanced inside. Moreover, since the rotation stop position of the parking lever 24 by the stop piece 53 is set on the braking side of the dead center position D of the toggle mechanism, if the temporary external force is eliminated, the rotation based on the pulling reaction force is performed. The moment acts so as to pull the parking lever 24 back to the set position S,
It shifts to the original stable input holding posture. When the parking brake is released, the electromagnet 55 is excited by energization through the preceding operation of the button switch 57 and the advancing stop piece 53 is forcibly retracted from the turning locus L by the electromagnetic attraction force. The parking lever 24 can be quickly returned to the release position C by a normal rotating operation.

[Effects of the Invention] As described in detail above, the present invention provides a toggle-type parking brake device with a lockable and disengageable stop mechanism for forcibly holding the input of the parking lever, and the rotation stop position of the parking lever is set to the toggle mechanism. Since it is set to the braking side from the dead point position, even if an unexpected external force is applied to the parking lever after the parking brake is activated, the overrun to the release side is reliably stopped by the stop mechanism, It is possible to prevent a vehicle accident due to a braking trouble.

Moreover, after the unexpected external force is erased, the parking lever immediately shifts to a stable input posture and is always isolated from the braking mechanism, so after the braking mechanism functions, external force is applied to the manual switch next time. Even if an extremely rare situation occurs, the safety is sufficiently ensured unless such two-direction external forces act at the same time.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention, FIG. 2 is a sectional view showing a concrete constitution of a braking mechanism, and FIG. 3 is a vertical sectional front view showing a conventional toggle type parking brake device. 20 ... Cable, 24 ... Parking lever 26 ... Link plate, 42 ... Stand 50 ... Stop mechanism, 53 ... Stop piece 55 ... Electromagnet, 57 ... Button switch

Claims (1)

[Scope of utility model registration request] 1. A pedestal fixed to a front portion of a vehicle body, a parking lever pivotally supported by the pedestal, and a brake actuating cable operatively connected to the parking lever via a toggle mechanism. In the parking brake device, a stop piece that always advances into the rotation locus of the parking lever by spring bias and is driven and retracted only by rotation interference of the parking lever on the braking side, and a manual switch are used. A stop mechanism including an electromagnetic unit for forcibly retracting the stop piece when energized is mounted on the pedestal, and the rotation stop position of the parking stop lever toward the release side of the advance stop piece is greater than the dead center position of the toggle mechanism. The parking brake device is also characterized by being set on the braking side.