JPH0338048Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a parking brake in which the parking brake lever is rotated from its original position around the center of rotation, thereby pulling the cable and operating the brake operating section. In particular, the present invention relates to a device that automatically adjusts the tension of a cable in accordance with the rotational operation of a parking brake lever.

BACKGROUND ART There is a type of parking brake for a passenger car, etc., in which a parking brake lever is rotated from its original position around the center of rotation, thereby pulling a cable and operating a brake actuating part. In this type of parking brake lever, if the brake shoe wears or the cable stretches, the tension of the cable decreases and the amount of rotational operation of the parking brake lever increases.

For this reason, the present applicants first applied for Utility Application No. 59-127246.
(a) a connecting member to which the end of the cable is connected and a threaded portion provided approximately on an extension line of the cable; and (b) a connecting member fixed to the side of the parking brake lever. (c) a guide member that holds the cable so as to be unrotatable around an axis and movable in the pulling direction of the cable; (d) an adjustment member having sawtooth-shaped outer peripheral teeth inclined in a direction opposite to the direction of rotation that increases the amount of engagement with the threaded portion while preventing movement in a direction opposite to the pulling direction; an engaging member that is arranged to be rotatable about the center of one rotation with a predetermined relative rotational resistance to the brake lever, and that is always rotated integrally with the parking brake lever; and (e) a fixed position. and is brought into contact with the engaging member which is rotated integrally with the parking brake lever, and the rotation range of the engaging member is set within the range necessary for operating the brake actuating portion. (f) a stopper member that restricts the rotation to a predetermined constant angle range that is approximately the same as the amount of rotation operation of the parking brake lever;
The engaging member is provided so as to be pressed by the outer peripheral teeth, and when the parking brake lever is rotated beyond the predetermined angular range from its original position, the engaging member engages with the stopper member. When the parking brake lever is rotated relative to the parking brake lever due to contact with the outer peripheral teeth, the outer peripheral teeth are rotated relative to each other in the direction of inclination to overcome the outer peripheral teeth, but in this state, the parking brake lever returns to its original position. When the engaging member is rotated in the opposite direction with respect to the parking brake lever due to contact with the stopper member, the engaging member is engaged with the outer tooth and the engaging member is rotated toward the parking brake lever. An automatic tension adjustment device has been proposed, which includes an engaging pawl that rotates the adjustment member in a direction that increases the amount of engagement with the threaded portion of the connection member and moves the connection member in the direction in which the cable is pulled.

In other words, if the amount of rotation of the parking brake lever exceeds a predetermined amount due to wear of the brake shoe or elongation of the cable, the engagement claw of the engagement member and the outer teeth of the adjustment member become relative to each other. When the parking brake lever is rotated and then operated to return to its original position, the outer tooth of the adjustment member that rotates together with the parking brake lever engages with the engagement claw of the engagement member, and the adjustment member is rotated in a direction that increases the tension of the cable, thereby automatically adjusting the tension of the cable.
Therefore, in a parking brake lever equipped with such an automatic tension adjustment device, the tension generated in the cable for a certain amount of rotational operation is maintained approximately constant regardless of wear of the brake shoe, etc. A suitable operating feeling is ensured.

Problems that the invention aims to solve However, after further experiments and research on the automatic tension adjustment device described above,
It has been found that the automatic tension adjustment device for the parking brake lever still has some problems that are not fully satisfactory. In other words, if an excessive operating force is applied to the parking brake lever when operating the parking brake, the components of the brake operating part, such as the brake shoe and brake drum, may be elastically deformed due to the excessive operating force. As a result, the amount of rotation of the parking brake lever becomes larger than necessary, so that the engagement pawl and the outer teeth are rotated relative to each other, and when the parking brake lever is operated to return to its original position, their engagement is interrupted. The interlocking pawl and the outer tooth engage with each other, causing the adjustment member to rotate, thereby increasing the tension of the cable. If the cable tension is increased more than necessary, the cable tension cannot be released sufficiently even when the parking brake lever is held in its original position, causing the brake to drag. is caused.

Means for Solving the Problems The present invention has been made to solve the above problems, and its gist is to provide the above-mentioned (a) connection member, (b) guide member, and (c) adjustment member. , (d) engaging member, (e)
an automatic tension adjustment device comprising a stopper member and (f) an engaging claw, the adjustment member being biased in a direction in which the cable is pulled until the tension of the cable exceeds a predetermined constant value; holds the adjustment member at an engagement position where engagement between the outer tooth and the engagement claw is permitted, but when the adjustment member is exceeded, it is elastically deformed and the engagement between the outer tooth and the engagement claw is disabled. An elastic member is provided that allows the adjusting member to move in a direction opposite to the pulling direction to a predetermined non-engaged position.

In the automatic tension adjustment device configured as described above, when the tension of the cable exceeds a predetermined certain value, the outer tooth of the adjustment member and the engagement claw of the engagement member cannot engage. The elastic deformation of the elastic member allows the adjustment member to move to a predetermined non-engaged position. Therefore, when the parking brake lever is rotated to the original position and the tension of the cable is smaller than the above-mentioned certain value, the adjustment member is held in the engagement position and the outer tooth and the engagement pawl are connected. However, if the cable tension cannot be released sufficiently and the tension exceeds the above-mentioned certain value, the outer tooth and the engagement claw The cable tension cannot be automatically adjusted because the cable cannot be engaged.

In other words, the automatic tension adjustment device of the present invention not only adjusts the rotation amount of the parking brake lever;
The cable tension is adjusted based on the tension generated in the cable when the parking brake lever is held in its original position, so if the parking brake lever is operated with excessive force and its rotation Even if the amount of operation exceeds a predetermined amount, if the cable tension exceeds a certain value, the tension will not be automatically adjusted.
This prevents the cable tension from increasing more than necessary. Note that the cable tension value at which the elastic member is elastically deformed until the adjusting member moves to the non-engaging position where the outer tooth and the engaging pawl are no longer engaged is such that the parking brake lever is at least in its original position. The tension is set to a value smaller than the tension that causes the brake to drag in the held state.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail based on the drawings.

1 and 2, reference numeral 10 denotes a sector fixed to the floor 16 of the vehicle body by a pair of legs 12 and 14, and a parking brake lever 18 is attached to this sector 10, and the parking brake lever 18 is rotated by a pin 20. pin 20
A large number of locking teeth 22 are provided on the outer periphery formed in an arc shape around the axis. The parking brake lever 18 is composed of a cylindrical operating section 24 and a mounting section 30 that has a pair of side walls 26 and 28 and has a substantially U-shaped cross section. is arranged across the sector 10 by means of a pin 20.
It is attached to.

A claw member 32 that can engage with the engagement tooth 22 provided on the sector 10 is rotatably attached inside the mounting portion 30 by a pin 34, and the claw member 32 engages the rod 36. It is connected to a knob (not shown) that protrudes from the tip of the operating section 24 via the operating section 24 . The rod 36 is always biased by biasing means (not shown) so as to rotate the pawl member 32 in the direction in which it engages with the locking teeth 22, thereby causing the parking brake lever 18 to move to the left in FIG. Although rotation in the circumferential direction is prevented, by pushing the knob into the operating portion 24 against the urging force of the urging means, the engagement between the pawl member 32 and the locking teeth 22 is released, and the parking brake is activated. Rotation of the lever 18 toward its original position is permitted. In this embodiment, the axis of the pin 20 corresponds to the center of one rotation.

One side wall 2 of the parking brake lever 18
The proximal end of 8, that is, the end attached to the pin 20, is made larger than the other side wall 26 and protrudes downward from the opening 38 of the floor 16, and a guide member is provided on the outside of the outer periphery thereof. 40 is fixedly installed, and an arcuate guide groove 42 that opens toward the outer circumference is formed between the guide groove 40 and the side wall 28 . One end of the cable 44 is connected to a brake operating section provided on a wheel (not shown), and the other end of the cable 44 is disposed below the floor 16 and is guided through the guide groove 42 and extends from the opening 38 of the floor 16. It is guided upward and connected to a connecting member 46 attached to the outside of the side wall 28. Note that a dust cover 48 is provided in the opening 38 of the floor 16.

The connecting member 46 has a rectangular parallelepiped shape, and as shown in detail in FIGS. 3 and 4, the U-shaped guide member 5 has a pair of flanges 50.
2 so as to be movable in the axial direction. This guide member 52 is disposed outside the side wall 28 along the pulling direction of the cable 44, and the flange 50 is fixed to the side wall 28 by welding or the like with the U-shaped opening side facing the side wall 28. The connecting member 46 is provided within a rectangular space formed between the guide member 52 and the side wall 28, and is non-rotatable about the axis but movable in the axial direction that coincides with the pulling direction of the cable 44. is maintained.

On the end surface of the connecting member 46 opposite to the side to which the cable 44 is connected, a male threaded portion 54 is provided upright along the moving direction of the connecting member 46, and an adjusting member 56 having a corresponding female thread is screwed into the end face. has been done.
The adjustment member 56 includes a hexagonal head 58 and an engaging portion 62 in which a large number of peripheral teeth 60 are formed on the outer peripheral surface, and the peripheral teeth 60 are arranged in a counterclockwise direction when viewed from the head 58 side, that is, a male thread. It has a sawtooth shape that is inclined in the direction opposite to the direction of rotation in which the amount of screw engagement with the portion 54 increases.

The adjustment member 56 has an elastically deformable coil spring 6 inserted between the adjustment member 56 and a washer 64 that is fitted into the male threaded portion 54 and seated on the edge of the guide member 52.
6, the cable 44 is biased in the pulling direction (the direction in which the cable 44 is pulled to actuate the brake actuating section), that is, in the direction away from the guide member 52, and the tension of the cable 44 is predetermined. The cable 44 is held in the engaged position shown in FIGS. 1 and 4 until it exceeds a certain value, but when the tension of the cable 44 exceeds the above certain value, it resists the biasing force of the coil spring 66. cable 44
The guide member 52 moves in the opposite direction to the pulling direction of the guide member 52.
be brought close to. When the coil spring 66 is completely elastically deformed as shown in FIG. 3, the adjustment member 56 is prevented from approaching any further and is positioned at a predetermined non-engaged position. , the connecting member 46 connects to the cable 44
This prevents the material from moving in the direction opposite to the direction of tension.

Moreover, by rotating the adjustment member 56,
The connecting member 46 is moved in the axial direction while being guided by the guide member 52, and the tension of the cable 44 is adjusted. Note that the male threaded portion 54 and the adjustment member 5
Reference numeral 6 is a normal right-handed thread, and when the adjusting member 56 is rotated clockwise, the connecting member 46 is moved in the direction in which the cable 44 is pulled, and the tension of the cable 44 is increased. Note that a notch 6 is provided in the side wall 28.
7 is formed so that a tool such as a spanner used for attaching or adjusting the adjusting member 56 can be inserted therein.

Here, the engagement position of the adjustment member 56 is determined by the balance between the biasing force of the coil spring 66 and the tension of the cable 44, but it is recommended to provide a stopper or the like to prevent the separation beyond a certain level. Accordingly, the engagement position of the adjustment member 56 can be defined. Also, coil spring 6
A thrust bearing or the like may be inserted between the adjustment member 6 and the adjustment member 56 or the washer 64 to facilitate their relative rotation.

On the other hand, the side wall 2 of the parking brake lever 18
An engaging member 68 is disposed near the outer side of the 8 side and substantially parallel to the side wall 28 thereof. The engagement member 68 has a substantially L-shape and is rotatably attached to the bent portion of the engagement member 68 by the pin 20, but there is a wave washer between the head 70 of the pin 20 and the engagement member 68. 72 is inserted, and the engaging member 68 and the parking brake lever 1
A collar 74 is inserted between the engagement member 68, the pin 20, and the parking brake lever 18, and provides a predetermined relative rotational resistance to the engagement member 68, the pin 20, and the parking brake lever 18. As a result, the engagement member 68
Normally, it is rotated around the pin 20 integrally with the parking brake lever 18, but if a force greater than the above-mentioned relative rotational resistance is applied, it will be rotated relative to the parking brake lever 18.

Engagement claws 76 are provided at both ends of the engagement member 68, respectively.
and an action section 78 are provided. Engagement claw 76
is pressed against the engagement portion 62 of the adjustment member 56 with a predetermined elastic force, and can be engaged with the outer tooth 60 in a state where it faces the outer tooth 60. However, if the tension of the cable 44 exceeds the above-mentioned certain value, , the adjustment member 56 resists the biasing force of the coil spring 66 and the guide member 52
when approached and moved to the disengaged position,
The engagement between the engagement claws 76 and the outer teeth 60 is disabled.

That is, when the tension of the cable 44 exceeds a predetermined constant value, the coil spring 66 is guided by the adjusting member 56 to a non-engaging position where the engagement claw 76 and the outer tooth 60 are no longer engaged. It functions as an elastic member that allows movement toward the member 52 side. Further, the biasing force of the coil spring 66 is such that the engagement between the outer tooth 60 and the engaging pawl 76 is maintained at a cable tension that is smaller than the tension that causes the brake to drag when the parking brake lever 18 is held at the original position. The above-mentioned constant value means a tension value that does not cause the brake to drag.

Further, the acting portion 78 is bent and extended so as to engage with a notch 80 formed in the sector 10, and both end edges 82 and 84 in the rotation direction can abut against both side walls 86 and 88 of the notch 80, respectively. has been done. As a result, the rotation range of the engaging member 68 is restricted to a certain angular range determined by the length dimension of the notch 80, and when the parking brake lever 18 is rotated beyond this certain angular range, In this case, the engaging member 68 is the wave washer 72.
The parking brake lever 18 is rotated relative to the parking brake lever 18 against the relative rotational resistance caused by the parking brake lever 18. In this embodiment, the portion of the sector 10 where the side walls 86 and 88 of the notch 80 are provided functions as a stopper member.

Next, the operation of the parking brake lever 18 configured as above will be explained.

First, when the parking brake lever 18 is held at the original position shown in FIG.
There is no significant tension in the cable 44, the adjustment member 56 is held in the engaged position, and the brake actuator of the wheel to which one end of the cable 44 is connected is not activated. At this time, the engaging member 68
One end edge 82 of the action portion 78 is in contact with one side wall 86 of a notch 80 formed in the sector 10 .

From this state, when the parking brake lever 18 is rotated clockwise around the pin 20 in the clockwise direction in FIG. 1, the cable 44 is pulled toward the other end connected to the connecting member 46, and The adjustment member 56 is moved closer to the guide member 52 against the biasing force of the coil spring 66. Thereafter, when the parking brake lever 18 is further rotated to prevent the adjustment member 56 from approaching any further, the tension in the cable 44 increases rapidly and the brake actuating section is actuated. When the parking brake lever 18 is rotated to the operating position where the other end green 84 of the operating portion 78 of the member 68 substantially contacts the other side wall 88 of the notch 80, the cable 44 has a connection member for actuating the brake operating portion. A sufficient amount of tension is generated. The width dimension of the action part 78 and the length dimension of the notch 80,
The amount of tightening of the adjusting member 56 screwed into the male threaded portion 54 of the connecting member 46 is set or adjusted in this manner.

After that, in order to release the operating state of the brake operating section, push the knob (not shown) protruding from the tip of the parking brake lever 18 into the operating section 24 to release the engagement between the locking tooth 22 and the pawl member 32. When the parking brake lever 18 is rotated to its original position, the tension on the cable 44 is released and the operating state of the brake operating section is released.

The parking brake is maintained in an activated state or a non-activated state by the above-mentioned operation, but in the parking brake of the type that transmits the operating force of the parking brake lever 18 via the cable 44 as described above, If the brake shoe of the brake actuating part is worn out or the cable 44 is stretched due to use, a sufficient amount of tension will no longer be generated in the cable 44 simply by rotating the parking brake lever 18 to the above position. In such a case, in order to obtain sufficient braking effect, it is necessary to rotate the parking brake lever 18 beyond the operating position.
Since the operating portion 78 of the engaging member 68 is already in contact with the side wall 88 of the notch 80 when the parking brake lever 18 is rotated to the operating position, it will not engage even if the parking brake lever 18 is rotated any further. Further rotation of the mating member 68 is prevented, and the mating member 68 is rotated counterclockwise in FIG. 1 relative to the parking brake lever 18.
At this time, since the adjusting member 56 is held in a non-engaging position close to the guide member 52 against the biasing force of the coil spring 66, the outer circumferential tooth 60 and the engaging claw 76 of the engaging member 68 are mutually disposed. The engagement pawl 76 is relatively rotated in the direction of inclination of the outer tooth 60 without being engaged.

In this manner, when the engaging member 68 is rotated relative to the parking brake lever 18, when the parking brake lever 18 is subsequently rotated to the original position, the operating portion 78 of the engaging member 68 is moved into the notch 80. The engaging member 68 is rotated clockwise in FIG. 1 relative to the parking brake lever 18 to its original position.
Further, as the tension of the cable 44 decreases, the adjustment member 56 is separated from the guide member 52 according to the biasing force of the coil spring 66, and the outer teeth 60 of the adjustment member 56 can be engaged with the engagement claws 76. In order to return the adjustment member 56 to the engagement position shown in FIG. Can be rotated clockwise. As a result, the male threaded portion 54 of the adjustment member 56
The amount of tightening increases, and the connecting member 46 is moved in the direction of pulling the cable 44 by that amount, and when the parking brake lever 18 is then rotated to the operating position, sufficient tension is generated in the cable 44. The tension in the cable 44 is automatically adjusted so that

On the other hand, even when the parking brake lever 18 is rotated to its original position, the cable 44
If the tension cannot be sufficiently released and the tension exceeds the predetermined value, the adjustment member 56 moves to a disengaged position close to the guide member 52 as the coil spring 66 elastically deforms. and outer peripheral teeth 60
The engagement between the engagement claw 76 and the engagement claw 76 is made impossible. For this reason, for example, if an excessive operating force is applied to the parking brake lever 18 when operating the parking brake, and the amount of rotational operation exceeds a predetermined amount, the parking brake lever 18 will then be activated. Even if the engaging member 68 is rotated relative to the parking brake lever 18 in the same manner as described above, if the tension of the cable 44 exceeds the above-mentioned certain value, Automatic adjustment of the tension as described above is not performed, and the cable tension is not increased more than necessary.

As described above, according to the automatic tension adjustment device of this embodiment, the cable tension is determined not only by the rotation amount of the parking brake lever 18 but also by the cable tension when the parking brake lever 18 is rotated to the original position. Therefore, even if the parking brake lever 18 is operated beyond a predetermined rotation amount due to excessive operating force, etc., the tension on the cable 44 does not necessarily increase. Even in such a case, the tension of the cable 44 will be maintained substantially constant.

As shown in FIG. 5, it is also possible to provide a claw portion 92 at the tip of the engagement member 68, which includes a plurality of engagement claws 90 that engage with the outer teeth 60 of the adjustment member 56.

Although one embodiment of the present invention has been described above in detail based on the drawings, the present invention can also be implemented in other embodiments.

For example, in the above embodiment, a coil spring 66 is inserted as an elastic member between the adjustment member 56 and the guide member 52, but a plate is attached to the side wall 28 of the parking brake lever 18 to hold the adjustment member 56 in the engagement position. A spring or the like is provided to allow the adjustment member 56 to move toward the guide member 52 when the tension of the cable 44 exceeds a certain value, thereby disabling the engagement between the outer tooth 60 and the engaging pawl 76. It can also be configured as follows.

Further, in the embodiment described above, the rotation range of the engaging member 68 is restricted by the notch 80 formed in the sector 10, but it is possible to restrict the rotation range of the engaging member 68 by engaging with other fixed members such as the floor 16. There is no problem even if it is regulated.

Further, in the above embodiment, the engaging member 68 is attached to the pin 20 like the parking brake lever 18, but it can also be rotatably attached to a separate member disposed concentrically with the pin 20.

The above-mentioned invention is merely an example of the present invention, and it goes without saying that the present invention can be implemented with various modifications and improvements based on the knowledge of those skilled in the art without departing from the spirit thereof.

Effects of the invention As detailed above, according to the automatic tension adjustment device of the invention, even if the amount of rotation of the parking brake lever exceeds a predetermined amount, the parking brake lever is returned to its original position. At this time, if more tension than necessary is generated in the cable, the elastic member disables the engagement between the outer tooth of the adjustment member and the engagement claw of the engagement member, and the tension of the cable can be adjusted. Therefore, the cable tension will not increase more than necessary due to excessive operating force, and there is no possibility that the brake will drag when the brake shoe is not activated.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing an embodiment of a parking brake lever equipped with an automatic tension adjustment device according to the present invention. FIG. 2 is a partially cutaway plan view of the parking brake lever shown in FIG. 1. 3 is a perspective view showing an automatic tension adjustment device provided on the parking brake lever of FIG. 1. FIG. 4 is a cross-sectional view of a portion of the apparatus of FIG. 3; FIG. FIG. 5 is a perspective view showing the main parts of another embodiment of the present invention. 10: Sector (stopper member), 18: Parking brake lever, 44: Cable, 46: Connection member, 52: Guide member, 54: Male threaded part (threaded part), 56: Adjustment member, 60: Peripheral tooth, 66: Coil Spring (elastic member), 68: engaging member,
76, 90: Engagement claw.

Claims (1)

[Scope of Claim for Utility Model Registration] A parking brake lever of a type in which a cable is pulled and a brake actuating part is actuated by pulling the parking brake lever when the parking brake lever is rotated around the center of one rotation from its original position, comprising: a connecting member having ends connected to each other and a threaded portion provided substantially on an extension line of the cable; a guide member that is held movably in the pulling direction; and a threaded portion of the connecting member held by the guiding member is screwed to prevent the connecting member from moving in a direction opposite to the pulling direction of the cable. on the other hand,
an adjustment member having sawtooth-shaped outer circumferential teeth inclined in a direction opposite to the direction of rotation in which the amount of engagement with the threaded portion increases; an engaging member that is rotatably arranged and is always rotated integrally with the parking brake lever; and an engaging member that is disposed in a fixed position and is rotated integrally with the parking brake lever. The engaging member is brought into contact with the member, and the rotational range of the engaging member is restricted to a predetermined constant angle range that is approximately the same as the amount of rotational operation of the parking brake lever necessary to operate the brake actuating portion. a stopper member provided on the engagement member so as to be pressed by the outer tooth, and when the parking brake lever is rotated beyond the predetermined angular range from its original position, the engagement member is When the parking brake lever is rotated relative to the parking brake lever due to contact with the stopper member, it is rotated relatively in the direction of inclination of the outer peripheral teeth and overcomes the outer peripheral teeth, but in this state, the parking brake lever When the brake lever is rotated toward the original position and the engaging member is rotated in the opposite direction relative to the parking brake lever due to contact with the stopper member, the engagement member engages with the outer tooth. the tension of a parking brake lever comprising an engaging pawl that rotates the adjustment member in a direction in which the amount of screw engagement with the threaded portion of the connection member increases when the adjustment member is engaged with the threaded portion of the connection member, and moves the connection member in the direction in which the cable is pulled The automatic adjustment device biases the adjustment member in a direction in which the cable is pulled, and keeps the adjustment member between the outer tooth and the engagement claw until the tension of the cable exceeds a predetermined constant value. The adjustment member is held at an engagement position where engagement is permitted, but when exceeded, it is elastically deformed and reaches a predetermined non-engagement position where engagement between the outer tooth and the engagement pawl becomes impossible. An automatic tension adjustment device for a parking brake lever, characterized in that an elastic member is provided that allows the lever to move in a direction opposite to the tensioning direction.