JPH01269649A - Stepping-on type parking brake device - Google Patents

Abstract

PURPOSE:To facilitate the release operation by guiding a release cable along a prescribed guide part, in the constitution in which a hook member for maintaining the brake state is separated from the engagement position with a ratchet wheel, through a releasing arm by the pulling operation of the release cable. CONSTITUTION:When a stepping-on lever 13 is turned around a pivotal supporting shaft 16 by stepping on a pedal 14, a cable guide part 24 turns at the same time, and a control cable 25 is wound onto the guide part 24, and a parking brake is operated. Then, brake state is maintained by the engagement of a hook member 17 with a ratchet wheel 15, when the stepping-on of the brake pedal 14 is released. The brake state is released by releasing the engagement with a ratchet wheel 15 by turning the hook member 17 in the counterclockwise direction through a pressing element 34 by a releasing arm 30, and at this time, a release cable 40 is guided by a guide surface 31a, and releasing operation is facilitated by varying the distance between the pulling direction and a pivotal supporting shaft 35 from H1 to H2.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to an improvement in a foot-operated parking brake device.

"Prior Art" In a conventional foot-operated parking brake device, the line of force of the release cable that transmits the release force to release the engagement between the ratchet wheel and the pawl member, and the pivot shaft that is the center of swing of the release arm are determined. The distance between the two is almost constant between the start of release and the time of completion of release, and therefore the release operation force is also almost constant or common.

``Problem to be solved by the invention'' However, such conventional foot-operated bark brake devices require a large amount of release force to initiate release.
Regardless of the above-mentioned distance when the release is near completion, even a small release force may be required, if the above-mentioned distance is increased in order to reduce the release force at the beginning of release, the distance required to pull the release cable becomes longer; If an attempt was made to shorten the distance, the distance would have to be reduced, and the release force would increase, making it difficult to release the brake, which was a problem that needed to be solved.

The reason why the release force is large at the beginning and at the end of brake release is large in the former case, and it can be gradually reduced thereafter is explained in the third section.
The figure is shown below with reference to the figure.

In the figure, θ: Claw member operating angle P, release resistance force F: Depressing force applied to the foot lever L2: Distance from the foot lever pivot axis to the beta (force application point) W: Brake response force (applied to the tip of the pawl member) If p is the friction coefficient, the relationship between the release resistance force P and the brake response force W is expressed by the following equation.

L, As1n02 P= W s:nO, + f −W sin
θ + ” g W CO5θ 1= W(s
1n Or + gcos θ!
)5inOz The results of the analysis are illustrated in FIG. Incidentally, the release resistance force P is made dimensionless and is expressed as Pl.

As shown in the figure, the release resistance force P decreases as the operating angle θ of the claw member increases, and on the other hand, the pull of the release cable increases over a distance S (in the figure, the release resistance force P decreases as the operating angle θ of the claw member increases). ) is gradually increasing.

The present invention was made the day before to address these problems with the conventional technology, and allows the brake to be released with a small release force even in the early stages of brake release, which requires a large release force, and furthermore, the release cable can be pulled only at a short distance. It is an object of the present invention to provide a foot-operated parking brake device having a small brake release mechanism.

"Means for Solving the Problems" What is the gist of the present invention to achieve these objects?

a foot lever pivotally supported on a support bracket fixed near the floor of the automobile; a control cable having one end connected to the foot lever for transmitting braking force; a pawl shape that is fixed to the foot lever and has a large number of locking teeth carved therein; and a pawl shape that is swingably supported by the support bracket and engages with the pawl shape to lock the foot lever. and a release arm having a pusher that engages with a swinging end of the claw member and pivoted to the support bracket in a swingable moat.

In the foot-operated parking brake device, the foot-operated parking brake device includes a release cable fixed to a locking point of the swinging portion of the release arm and transmitting a release force, the release cable being fixed to the locking point of the swinging portion of the release arm. A release cable guide section having a guide surface for guiding the release cable in a direction away from the pivot axis of the release arm is provided, and the release cable is wound along the release cable guide section. This is a foot-operated parking brake device.

"Operation" When the release cable is pulled to release the brake, the release arm attempts to rotate around its pivot axis.

The release cable is wound along a resource cable guide provided at a swinging portion of the release arm,
The release cable guide section has a guide surface extending from the starting end, which is the connection point between the release cable and the release arm, in the direction in which the release cable is wound and away from the pivot axis of the release arm. When the cable begins to be pulled, the distance between the release force line and the pivot shaft of the release arm is large, and a large release rotational force can be obtained with a small release force.

The release arm is gradually rotated by being pulled by the release cable, and a suppressor fixed to one tail end presses the tail end of the claw member to rotate the claw member.

As the release drum rotates, the guide surface of the release cable on the release drum gradually approaches the attachment point of the release cable, and the distance between the release force line of the release cable and the pivot axis of the release arm increases. As a result, the release rotational force applied to the release arm is reduced.

In part, the release resistance force generated at the meshing portion between the locking tooth of the ratchet wheel and the pawl of the pawl member is greatest when the pawl member is fully engaged, and gradually decreases as the pawl member rotates. Even if the release rotational force of the release arm becomes small, there is no problem in releasing the engaged state against the release resistance force.

"Example" Hereinafter, one embodiment of the present invention will be described based on the drawings.

The foot-operated parking brake device W110 is mounted near the floor of the vehicle, and includes a foot-operated lever 13 rotatably pivoted to a support bracket 11 fixed by a bolt 12, and a foot-operated parking brake device 13 fixedly attached to the foot-operated lever 13. A claw member 17 that engages with the locking teeth 15a of the model wheel 15 to maintain braking force.
and a release arm 30, which has a suppressor 34 at its tail end that presses the swinging end 17b of the claw member 17, and closes the release cable 40 near its tip, and whose rear end is engaged with the foot lever 13, and which is It consists of a control cable 1 to a roll cable 25 that is wound around a control cable guide member 24 fixed to the lever 13 and transmits braking force.

A tread 1 is provided at the tip of the foot lever 13 in the direction to the side of the operator.
A pedal 14 facing 4a is fixedly mounted, and a pivot shaft 16
control cable guide member 2 so as to surround it.
4 is fixedly installed, and similarly to 2, locking teeth 15a of the mold wheel 15 are carved around the pivot shaft 16.

A pawl member 17 having a pawl 18 that engages with the mold wheel 15 is rotatably supported on a pivot shaft 19 of the pawl member, and the swinging end 17b of the elongated arm 17a is rotated by the pusher of the release arm 30. 34 people are coming. Further, a spring 20 is attached to the end 17c of the claw member opposite to the arm 17a, which always urges the claw 18 of the claw member 17 to engage with the locking teeth 15a of the mold wheel 15.

The release arm 30 is swingably supported on a pivot shaft 35 of the release arm, and a pusher 34 is fixedly attached to the swinging tail end 33. The tip of the release cable 40 is filled with earth.

As shown in FIG. 2, the release cable 30 has a guide surface 31a at the swinging portion of the release arm 30, which starts near the starting end or the connection point 32 with the release cable 40 and moves away from the pivot shaft 35 of the release arm. A guide section 31 is also provided.

The release cable 4o is connected to the release arm 30 at a fastening point 32, and is wound along the release cable guide section 31, with a release knob (not shown) provided at the end.

The control cable 25 has one end plugged into the foot lever 13, is wound along the control cable guide member 24, and extends along the vehicle body, and transmits a braking force corresponding to the amount of depression of the foot lever 13. ing.

Next, the action will be explained.

When the pedal 14 is depressed, the foot lever 13 moves to the pivot shaft 16.
It rotates clockwise in FIG. 1 around , transmitting braking force corresponding to the amount of depression to the control cable 25. On the other hand, since the pawl member 17 is always biased toward the ratchet wheel 15, when the foot is released from the pedal 14, the locking tooth 15a of the mold wheel 15 and the pawl 18 of the pawl member 17 engage with each other at that position. It prevents the foot lever from returning and enters the braking state.

In the braking state, a braking response force W of a fixed ratio corresponding to the braking force is applied to the tip of the claw 18 of the claw member.

When the release knob provided at the end of the release cable 40 is pulled to release the brake state, at the beginning of the pull, the distance between the pulling direction of the release cable 40 and the pivot shaft 35 of the release arm is as shown in FIG. It is Hl.

When the release cable 40 is continued to be pulled, the release arm 30 rotates itself counterclockwise while rotating the claw member 17 counterclockwise via the pusher 34, and moves along the guide surface 31a of the release cable guide section 31. The release cable 40, which is wrapped around the
Direction of release cable 40 and release arm pivot shaft 35
The distance H2 is smaller than Hl.

Therefore, if a release force of the same magnitude is applied to the release arm 30, the release rotational force acting around the pivot shaft 35 of the release arm is large at the beginning of release and gradually decreases.

On the other hand, the amount of movement of the knob that attracts the release cable 40 is large at the beginning of pulling for the same rotation angle of the release arm 30, and decreases as the distance H decreases.

However, as shown in the analysis results already mentioned, the claw 18 of the claw member
The release resistance force for separating from the claw-shaped locking tooth 15a is initially large and gradually decreases as the release operation progresses, so it is consistent with the configuration that the release rotational force is initially large and gradually decreases. There is.

"Effects of the Invention" According to the foot-operated parking brake device according to the present invention, it is possible to release the brake with a small release force even at the beginning of release, which requires a large release force, and the pull of the knob for release is small. The brake release operation of the foot-operated parking brake device is extremely easy.

[Brief explanation of the drawing]

1UA to 2 show an embodiment of the present invention, in which FIG. 1 is a front view of a foot-operated parking brake device, and FIG.
FIG. 3 is an explanatory diagram of a mechanism for locking and releasing the brake, FIG. 3 is an explanatory diagram for analyzing the engagement between the pawl mold and the pawl member, and FIG. 4 is a diagram showing an example of the analysis results. lO... Foot-operated parking brake device 11...
Support bracket 13... Foot lever 15... Claw type 15a... Claw type locking teeth 16... Pivot shaft 17... Claw member 17b... Swinging end 30 of the claw member...・Release arm 31... Release cable guide part 31a... Guide surface 32... Fastening point 33...
- Swinging tail end of the release arm 34...Pusher 35...Pivot shaft 40 of the release arm...Release cable Fig. 2 Fig. 3

Claims (1)

[Scope of Claims] A foot lever pivotally supported on a support bracket fixed near the floor of an automobile; a control cable having one end connected to the foot lever for transmitting braking force; and a pivoting support for the foot lever. a ratchet wheel provided concentrically with the shaft and solidly attached to the foot pedal lever and having a large number of locking teeth carved therein; a claw member that locks the lever; a release arm that has a pusher that engages with a swinging end of the claw member and is swingably supported on the support bracket; and a swinging portion of the release arm. In a foot-operated parking brake device comprising a release cable fixed to a locking point and transmitting a release force, the starting end of the release cable is placed at the locking point of the swinging portion of the release arm, and the release cable is connected to the locking point. A foot-operated parking brake device, comprising: a release cable guide section having a guide surface that guides the release arm in a direction away from a pivot axis; and the release cable is wound along the release cable guide section.