JPH0138701B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a parking brake control device.

FIG. 1 shows an outline of a conventional parking brake control device known from Utility Model Application No. 114967/1983. Reference numeral 1 denotes a rack that is fixed to the vehicle body 2 and has teeth 1a with a constant pitch on the peripheral edge.The parking hand lever 3 is rotated around a pin 4 serving as a pivot point, and the parking cable 5 is used to park the vehicle. After operating the brake, press the hand lever 3.
A presser pawl 6 rotatably attached to the rack 1 ratchets into engagement with the tooth 1a of the rack 1 under the biasing action of a tension spring 7, thereby resisting the brake reaction force and maintaining the brake in the braking state. When the brake is released, the release mechanism for releasing the ratchet engagement is activated, that is, the release lever 8 is pushed and the holding claw 6 is rotated around the pin 9 against the elastic force of the tension spring 7 to release the rack 1. Release the ratchet engagement and return the parking hand lever 3 to its original position.

However, in such a conventional parking brake control device, the hold-down pawl 6 has a structure in which the hold-down pawl 6 is engaged with the teeth 1a of a relatively large constant pitch of the rack 1, so that the hold-down pawl 6 and the rack 1 are The locking interval (hereinafter referred to as the notch interval) is constant, and therefore the braking force changes greatly in stages. In many cases, more operating force than necessary is required for the operation, and when the presser pawl 6 is engaged with one tooth removed from the easy 1, the braking force becomes insufficient, resulting in a decrease in operating feeling and braking performance.

In addition, as a means of reducing the notch interval as a whole, the pitch of the teeth 1a of the rack 1 is made small, or as shown in FIG. It has been proposed to use together with a rack 1' (hereinafter referred to as a double rack) in which racks 1'b are stacked and fixed by shifting the racks 1'b by half a pitch, a holding claw 6 which is wider than the conventional one. However, manufacturing a large number of teeth with small pitches requires a lot of man-hours, and the double rack has a complicated structure, resulting in a significant increase in price and weight.

The present invention has been made in view of the above drawbacks, and
The purpose is to solve the above-mentioned drawbacks by making the pitch of the teeth of the rack smaller on the terminal end side than on the starting end side, thereby reducing the notch spacing near where an appropriate braking force is generated when operating the parking hand lever. It is said that

Hereinafter, the present invention will be explained with reference to the illustrated embodiments, in which the same parts as those in the conventional art are denoted by the same reference numerals. Third
4, numeral 1 is the rack, 2 is the vehicle body, 3 is the parking hand lever, 4 is the pin, and 5 is the parking hand lever.
1 is a parking cable, 6 is a clamp, 7 is a tension spring, 8 is a release lever, and 9 is a pin, and the above configuration is the same as the conventional one.

The teeth 10 of the rack 1 with which the presser pawl 6 is to be ratcheted are arranged so that the lower end side in FIG. The teeth 10a are formed with a similar relatively large pitch, and the upper end side in FIG.
0b. That is, in the brake release state or in the vicinity where a strong operating force is not normally required, the teeth 10a of the rack 1, which are the locking points of the presser claws 6, are manufactured with a relatively large pitch, and the necessary and sufficient control is made. In a range where a strong operating force is required to obtain power, the teeth 10b of the rack 1 are manufactured with a smaller pitch than the teeth 10a, so that the change in operating force is made in relatively small steps, and the necessary This makes it easier to obtain a strong braking force with less operating force than before.

Furthermore, the tooth 10a or 10b is connected to the pivot point of the parking hand lever 3, and in turn, to the rack 1 of the holding pawl 6, which is rotatably supported on the lever 3 by a pin 9.
As in the conventional case, it should be formed so as to substantially coincide with a circular arc centered on the pin 4, which is the center of rotation. In this case, there are structural examples in which the peaks of the teeth 10a and 10b are aligned on the same circular arc to structural examples in which the respective valleys are aligned on the same circular arc. According to the former example, the position of the holding pawl 6 relative to the parking hand lever 3 when getting over the teeth 10a, 10b is constant, and the feeling when the holding pawl 6 is getting over each of the teeth 10a, 10b is constant. According to the latter example, the positional relationship of the presser claws 6 engaged with the teeth 10a, 10b with respect to the lever 3 is constant, and the operating feeling of the release lever 8 is constant. Incidentally, the pitch of the teeth 10a and 10b may be varied for each tooth or for every several teeth, so that the pitch can be changed in multiple stages.

As explained above, the present invention provides a parking hand lever rotatably pivoted on the vehicle body side, and a parking hand lever rotatably pivoted on the hand lever, the tip of which is biased in the engagement direction. A parking brake control having a holding pawl, a rack fixed to the vehicle body and having teeth that ratchet engages with the holding pawl in a direction that resists brake reaction force, and a release mechanism for releasing the ratchet engagement. In the apparatus, the pitch of the teeth of the rack is set smaller on the terminal end side than on the starting end side.

Therefore, the operating force near the point where the necessary braking force can be obtained has a relatively small stepwise change, and the structure is inexpensive and the required braking force is smaller than the conventional one. Therefore, the reliability of the parking brake can be improved.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a conventional parking brake control device, FIG. 2 A is a partial front view of a conventional double rack, FIG. 2 B is a side view of the same, and FIG. 3 is a parking brake according to the present invention. FIG. 4 is a front view of the main parts of the control device. 1: Rack, 2: Vehicle body, 3: Parking hand lever, 4: Pin, 6: Holder claw, 7: Tension spring, 8: Release lever, 9: Pin, 10a: Large pitch tooth, 10b: Small pitch tooth .

Claims (1)

[Claims] 1. A parking hand lever rotatably pivoted on the vehicle body side, a holding pawl rotatably pivoted on the hand lever and whose tip end is biased in the engagement direction, and a parking hand lever fixed to the vehicle body, A parking brake control device comprising: a rack having teeth that ratchet engage with the holding pawl in a direction that resists brake reaction force; and a release mechanism for releasing the ratchet engagement; A parking brake control device characterized in that the terminal end side is set smaller than the starting end side.