JP2585010Y2 - Foot-operated parking brake - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foot-operated parking brake for an automobile.

[0002]

2. Description of the Related Art In recent years, the number of vehicles employing an automatic transmission has been increasing, so that a manual parking brake can be installed on the center console portion beside a driver's seat as in the past. It's gone.

For this reason, vehicles equipped with an automatic transmission generally adopt a configuration in which a foot-operated parking brake is installed below the dashboard.

[0004] As an example of such a foot-operated parking brake, for example, a drum that rotates around a support shaft fixed to a vehicle body side bracket is provided, and the parking brake is braked by being rotated by a foot operation. Brake arm for operation (foot pedal)
A parking brake cable connected to the tip of the brake arm, a return spring that urges the brake arm to return and rotate, and the drum provided between the support shaft and the brake arm. A coil spring that locks the return rotation of the brake arm with a frictional force generated therebetween; and a lock release member that releases the frictional force of the coil spring, and one end of the coil spring is locked to the support shaft. At the same time, there is a type in which the other end is locked by the unlocking member, and the coil portion is externally inserted into the drum and the support shaft (for example, Japanese Patent Application Laid-Open
-306957).

In the configuration of the foot-operated parking brake, when the rear end of the brake arm, which is a foot pedal, is depressed, the drum also rotates together with the brake arm. At this time, the coil spring exerts a tightening force only by the rotation of the drum in accordance with the rotation of the brake arm in the return direction, that is, the rotation corresponding to the rotation of the parking brake cable, and When the brake arm is depressed, only a loose initial tightening force is applied, so that the drum rotates relatively smoothly by a predetermined rotation angle corresponding to a desired depression angle.

When the stepping operation of the brake arm is stopped by rotating by the predetermined rotation angle, thereafter, the above-described pulling force of the parking brake cable connected to the tip of the brake arm acts in the reverse direction. This time, the drum rotates and stops by a predetermined minute amount in the direction in which the tightening force of the coil spring increases, and is securely locked at the time of the stop.

On the other hand, in the locked state, when the unlocking member such as the release lever is pulled in the release direction, the free end (non-locking side end) of the coil spring is pushed in the release direction and is released. The diameter of the coil spring increases. As a result, the tightening force of the coil spring on the locking drum is reduced, and the rotation of the drum and the brake arm becomes free. For example, the coil spring returns to the original non-depressed state by the pulling force of the return spring.

As is apparent from the above description, the parking brake can be locked and unlocked only by changing the tightening force of the coil spring wound around the drum portion of the brake arm in this configuration. The advantages are greater than those employing a ratchet mechanism which causes an increase in weight, size and cost.

However, in the case of the above configuration, in order to obtain a sufficient binding force (locking force) against the reaction force of the brake cable, the diameter of the coil spring and the diameter of the drum must be increased in order to increase the friction surface. I have no choice.

However, as the diameter of the coil spring on the other side is increased, the rigidity of the spring is correspondingly reduced.

In general, the coil spring is wound after giving a certain initial frictional force (tightening internal pressure) to the drum. However, when the rigidity of the coil spring decreases as described above, the brake arm In the initial stage, the fixed end of the coil spring slightly rises from the drum surface.

As a result, when the brake arm is locked after the stepping is completed, a predetermined time loss (time lag) occurs until the fixed end of the coil spring is wound on the drum surface due to the lifting margin, which eventually leads to the stepping stroke. It appears as a loss of quantity, that is, a shortage of brake cable pulling stroke. Therefore, as it is, only a braking force slightly lower than the proper braking force originally intended by the driver can be set.

Therefore, as one of measures against the problem, for example, as shown in FIG. 6, a fixing member 1 having an adjusting nut 12a for fixing the coil spring fixing end 11a side.
By using the adjustment nut 12a after applying the coil spring 11, a sufficient tensile force is applied to the fixed end 11a side of the coil spring 11 to prevent the coil spring fixed end 11a from floating. It is thought that.

As shown in detail in FIG. 6, for example, the fixing member 12 includes a base 12b projecting from the side wall surface of the mounting bracket by a predetermined height, and a spring fixing side end formed on the upper surface of the base 12b. A fitting hole 12c, a pressing member 12d that covers the upper part of the spring fixing side end fitting hole 12c and is fixed to the upper surface of the base 12b by bolts 21 and 22, and a spring fixing side end fitting hole. And an adjustment nut 12a screwed into a projecting end thread portion of the fixed-side spring end portion 11a projecting rearward through the 12c. Reference numeral 3 denotes a support shaft, 4 denotes a drum, and 10 denotes a spacer.

If the fixed end 11a of the coil spring 11 is fixed in this way, the fixed end 11a of the coil spring 11 can always be given a preload in the direction in which the drum is brought into contact with the drum. At least the rising of the winding start portion of the coil spring fixed side end portion 11a which occurs when the pedal is depressed is less likely to occur. The floating of the wound portion on the coil spring fixed end 11a side due to a variation in the distance between the coil spring 12 and the coil spring fixed end 11a is absorbed.

[0016]

By the way, when the coil spring 11 is wound around the drum 4 between the winding inner diameter φ of the coil spring 11 and the drum 4, the coil spring 11 becomes φ ₁ −φ ₂ = Δφ, so that the coil spring 11 can exert a force to wind the drum 4 around the drum 4 as described above by the interference Δφ. However, in such a lock spring type parking brake device, as described above, a braking loss occurs due to the lifting of the coil spring fixed end side, and therefore, the lifting of the coil spring fixed end is suppressed in order to suppress the braking loss. In order to suppress the floating, it is generally necessary to use a fixing member or the like to forcibly hold, as described above. On the other hand, a method of reducing the above-mentioned Δφ itself is also conceivable. However, when braking with a large load, when the interference Δφ is reduced, the winding force itself of the lock spring to the drum is reduced, and the coil spring is wound around the drum and bites, causing a time lag until the brake is locked, Conversely, there arises a problem that a braking loss occurs.

On the other hand, when releasing the braking, the arm on the free end side of the coil spring is lifted by the release lever to release the braking. However, in general, the spring constant of the free end side of the coil spring in the release direction is low, and the spring characteristic of the spring deteriorates due to operation durability performance, and the pressing force (winding force) on the drum is reduced. There is a problem that the braking amount due to the time lag at the time of the braking lock is further promoted.

In general, wear is easily generated between the drum and the coil spring. To prevent this, oil having a predetermined viscosity is used between the drum and the coil spring. Due to the frictional force in this part, the phenomenon occurs in which the drum and the coil spring do not idle and the tightening of the coil spring moves in the loosening direction,
As a result, there is also a problem that a time lag until the lock at the time of the braking lock occurs.

In order to solve such a problem, for example, a sleeve-like elastic member may be fitted around the outer periphery of the coil spring to apply a radial tightening force.
In such a case, the time lag at the time of braking lock becomes small, but at the same time, at the time of unlocking, the above-mentioned elastic member regulates the spread of the coil spring from the drum.

[0020]

SUMMARY OF THE INVENTION The present invention has been made for the purpose of solving the above problems, and has the following structure.

That is, the foot-operated parking brake of a vehicle according to the present invention comprises a foot pedal rotatably supported by a support shaft fixed to a vehicle body-side mounting bracket, a brake cable connected to the foot pedal, A drum portion rotatably supported on a support shaft, and fixed to the foot pedal, wound and held on the drum portion, while reducing the binding force by rotation of the drum portion due to depression of the foot pedal; A foot-operated parking brake, comprising: a coil spring that increases a binding force by rotation of the drum portion due to a tensile force of the brake cable; and a fixing member that fixes a fixed end side of the coil spring to the mounting bracket. Only the free end side of the coil spring has a predetermined elasticity in the coil spring winding direction. To provide a biasing means for pressing urged,
The urging means urges only the free end side of the coil spring in the drum binding direction.

[0022]

The invention of the present application is configured as described above and, as a result, exhibits the following operation corresponding to the configuration.

That is, in the configuration of the foot-operated parking brake of the automobile according to the invention, a foot pedal rotatably supported by a support shaft fixed to the vehicle body-side mounting bracket, and a brake cable connected to the foot pedal are provided. ,
A drum portion rotatably supported by the support shaft, and fixed to the foot pedal; wound and held on the drum portion;
A coil spring that reduces the binding force by the rotation of the drum portion caused by the depression of the foot pedal and increases the binding force by the rotation of the drum portion by the tension force of the brake cable, and the fixed end side of the coil spring is A foot-operated parking brake is provided as a premise including a fixing member fixed to the mounting bracket.

Therefore, in the configuration of the foot-operated parking brake, when the rear end of the brake arm, which is a foot pedal, is first depressed, the drum also rotates together with the brake arm. At this time, the coil spring rotates the brake arm in the return direction,
That is, the tightening force is exerted only by the rotation of the drum corresponding to the turning force generated by the pulling force of the parking brake cable. When the brake arm is depressed, only the initially set loose tightening force is used. Since it does not act, the drum rotates relatively smoothly by a predetermined rotation angle corresponding to the desired stepping angle.

Then, when the stepping operation of the brake arm is stopped by rotating by the predetermined rotation angle, thereafter, the above-described pulling force of the parking brake cable connected to the tip of the brake arm acts in the opposite direction. This time, the drum rotates and stops by a predetermined minute amount in the direction in which the tightening force of the coil spring increases, and is securely locked at the time of the stop.

On the other hand, in the locked state, when the non-locking side free end of the coil spring is pushed in the release direction by, for example, a release lever or the like, the diameter of the coil spring increases. As a result, the tightening force of the coil spring on the locking drum is reduced, and the rotation of the drum and the brake arm becomes free,
For example, it returns to the original non-depressed state by the tensile force of the return spring.

Further, in the configuration of the foot-operated parking brake for an automobile according to the present invention, only the free end side of the coil spring in the above-described premise configuration is pressed and urged with a predetermined elasticity in the coil spring winding direction. An urging means is provided, and the urging means urges only the free end side of the coil spring in the drum binding direction.

That is, in the configuration of the present invention, the coil spring is provided only on the free end side of the locking coil spring with respect to the minimum set value of the interference of the drum and the lock spring for satisfying the braking force. Locks the biasing means that applies a biasing force in the direction in which the coil spring is wound, thereby reducing the time lag until the coil spring bites into the drum without restricting the entire direction of extension of the coil spring and reducing the time lag between the drum and the coil spring. This effectively compensates for a decrease in frictional force due to oils and fats between them and a lack of fastening force due to deterioration of durability at the free end side of the coil spring.

As a result, according to the foot-operated parking brake of the present invention, a sufficient braking force holding function at the time of locking can be maintained with good responsiveness without lowering of the unlocking function.

[0030]

Therefore, according to the structure of the foot-operated parking brake of the vehicle of the present invention, a highly reliable foot-operated parking brake capable of always realizing the parking brake force substantially as set by the driver in a responsive manner is provided. Will be able to

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) First Embodiment FIGS. 1 to 6 show the configuration of a foot-operated parking brake of an automobile according to a first embodiment of the present invention.

First, in FIGS. 1 to 6, reference numeral 1 denotes a mounting bracket for mounting the parking brake on the vehicle body 2 side, and a support shaft 3 for supporting a foot pedal is fixed to the mounting bracket 1 so as to protrude laterally. ing. A foot pedal 5 to which a drum 4 is fixedly attached at the distal end side of the support shaft 3 is rotatably fitted with the support shaft 3 as a fulcrum as shown by a virtual line in FIG. A connecting portion 5a of the brake cable BC is provided in the middle of the foot pedal 5, and a brake cable is connected to the connecting portion. A foot portion 8 is formed at the rear end of the foot pedal 5. Further, a spring 9 for returning the pedal when returning is interposed between the rear end of the foot pedal 5 and the mounting bracket 1.

On the other hand, a spacer 10 made of synthetic resin is interposed between the drum 4 and the support shaft 3 as shown in FIG. Then, a coil spring (lock spring) 11 for locking the depressed state of the foot pedal 5 is wound around the outer peripheral surface of the drum 4 while maintaining a predetermined initial internal pressure (tightening pressure).

The coil spring 11 has one end (outer end of the drum) rising obliquely upward as a free end 11b, and the other end (pedal side) as a fixed end 11a on the side of the mounting bracket 1. As shown in FIG. 6, it is locked and fixed via a fixing member 12 having a predetermined height. The fixing member 12 includes a base 12b protruding from a side wall of the mounting bracket 1, a concave spring end fitting hole 12c formed on the upper surface of the base 12b, and a spring end fitting hole 12c.
A pressing member 12d that covers the upper part of the base and is fixed to the upper surface of the base 12b by bolts 21 and 22, and a protruding end of a fixed-side spring end 11a that projects rearward through the spring end fitting hole 12c. And an adjusting nut 12d screwed into the thread portion. The outer periphery of the coil portion from the base of the coil spring fixed end 11a to the base of the drum 4 (the part where the coil spring starts to be wound on the peripheral surface of the drum 4) to the base of the free end 11b is, for example, as shown by a virtual line in FIG. FIG. 3 shows a ring member 13 having a hook-like cross section shown in FIG. 4 for restricting the lifting (spreading) of each wire loop of the coil spring winding portion in the radial direction of the drum at the start of depressing the foot pedal 5. Are fitted together
(Note that the ring member 13 is omitted in FIG. 6).

The ring member 13 includes a vertical wall portion 13b having a fitting hole 13a to be fitted into the drum 4, and a vertical wall portion 1b.
3b, the flange 13c protrudes laterally from the base 3b. The flange 13 has a fixed end 11a base of the coil spring 11 at one end as shown in FIGS.
An engagement recess 13e with which the (winding start portion) engages is formed. The coil spring contact surface of the vertical wall portion 13 forms a spiral projection 13d corresponding to the winding pitch ΔP of the coil spring 11.

Then, the ring member 13 having the above structure is
As shown in the figure, the drum 4 and the coil spring 11 wound around the drum 4 are tightly fitted.

Therefore, in this state, the coil spring fixed end 1 at the start of the depression of the foot pedal 5 is set.
The lifting of the coil wire loop on the 1a side is caused by the fixing member 1
Together with the tension locking force on the second side, the frictional force is reliably prevented by the flange portion of the ring member 13, and the loss of the tension stroke (braking loss) of the brake cable 6 due to the floating is hardly generated.

Further, in this case, the height of the ring member 13 in the circumferential direction changes in accordance with the winding pitch ΔP of the coil spring 11 at the coil spring contact surface of the coil spring side vertical wall portion 13b. Because of the projecting spiral surface, the axial pressing force of the coil spring 11 makes it possible to constantly and stably adhere to the side wall surface of the foot pedal 5, so that it is perpendicular to the conventional axis. Does not occur.

As a result, the coil spring restricting force of the ring member 13 is always maintained in a stable state as designed, and the return sensitivity of the foot pedal 5 is also improved.

Therefore, the fixed end 11a of the coil spring 11 is connected to the adjusting nut 1 of the fixed member 12.
The ring member 13 is sufficiently pulled by the fastening force of 2a, and is reliably braked and held by the expansion restricting force of the ring member 13.

According to the above-described structure for holding the fixed end of the coil spring, first, the fixed end 11a of the coil spring 11 is always given a preload in the drum contact direction as shown by the solid line in FIG. In addition, in order to be able to sufficiently absorb variations in the diameter of the drum, the diameter of the support shaft, the position between the support shaft and the fixing member, and the like, the coil spring fixed side end which has conventionally occurred when the foot pedal 5 is depressed is depressed. The rising of the winding start portion of the portion 11a hardly occurs, and also due to the variation in the diameter of each part such as the drum 4 and the support shaft 3 at the time of stepping, the variation in the distance between the support shaft 3 and the fixing member 12, and the like. The rising of the coil spring winding portion is also sufficiently absorbed.

Reference numeral 15 denotes the mounting bracket 1.
A release lever rotatably fitted to a shaft portion 31 provided on the outer end side boss portion 1a of the release lever 15; one end 15a side of the release lever 15 is connected to an upper portion of the mounting bracket 1 via a spring 16; The spring 16 has one end side pressing piece 16a which is connected to a tip end of a locking piece (not shown), and the tip side release piece 15b of the spring 16 is free end 11b of the coil spring 11.
It is always urged away from the side. The release piece 15b of the release lever 15 is provided with a release cable connecting portion (not shown), and the distal end of the release cable is connected to the connecting portion. When the release cable is pulled, for example, against the urging force of the tension spring, the release piece 15b pushes the free end 11b of the coil spring 11 in the direction of the arrow (a) in FIG. The binding force of the coil spring 11 on the outer peripheral surface of the drum 4 is reduced. As a result, the locked state of the foot pedal 5 is released, and the foot pedal 5 returns to the original non-depressed state by the tensile reaction force of the brake cable BC.

Further, in the structure of the first embodiment of the present invention, in addition to the above structure, the minimum set value of the interference of the drum 4 and the lock coil spring 11 for satisfying the braking force is set. , The locking coil spring 1
The shaft 3 is coaxial with the release lever 15 as an urging means for applying a predetermined urging force in the direction in which the coil spring 11 is wound around the drum 4 only on the side of the free end 11b.
1 to prevent the coil spring 11 from biting into the drum 4 without restricting the entire coil spring 11 in the expanding direction by the biasing end 32a. It is possible to compensate for a decrease in frictional force due to oils and fats between the coil spring 11 and the coil spring 11 and an insufficient fastening force due to deterioration in durability of the free end 11b of the coil spring 11 described above. Therefore, without lowering the lock release function,
The promotion and expansion of the braking loss due to the time lag at the time of the conventional braking lock can be prevented as much as possible. Reference numeral 33 denotes a stopper for one end 15a of the release lever 15 and a locking end 32b of the biasing spring 32.
Reference numeral 34 denotes a release piece 15b of the release lever 15 and a stopper on one side of the locking of the spring 16.

(2) Second Embodiment Next, FIGS. 7 and 8 show the structure of the biasing means on the free end side of the coil spring of the foot-operated parking brake of the automobile according to the second embodiment of the present invention. ing.

In the biasing structure of the free end portion of the coil spring of this embodiment, the biasing spring 32 wound around the support shaft 31 of the release lever 15 in the configuration of the first embodiment is provided on the mounting bracket 1 side. A leaf spring 50 bent in a substantially rectangular shape is employed, and the same pressing action as in the first embodiment is realized by the pressing elastic force of the leaf spring 50.

That is, in the configuration of the present embodiment, the free end 11b of the lock coil spring 11 is set with respect to the minimum set value of the interference between the drum 4 and the lock coil spring 11 for satisfying the braking force. As the urging means for applying a predetermined urging force in the direction in which the coil spring 11 is wound around the drum 4 only on the side, a distal end pressing piece 50a of a leaf spring 50 whose base end 50b is fixed to the bracket 1 with bolts 51 is used. The elastic pressing force reduces the time lag until the coil spring 11 bites into the drum 4 without restricting the entire coil spring 11 in the expanding direction, and reduces the time lag between the drum 4 and the coil spring 11. It is also possible to compensate for a decrease in frictional force due to oils and fats and a lack of securing force due to deterioration in durability of the coil spring free end 11b. You. Therefore, as in the case of the first embodiment described above, without a decrease in the lock release function, it is possible to promote a braking loss amount due to a time lag at the time of braking lock as in the related art.
Expansion is also prevented as much as possible.

(3) Third Embodiment Next, FIG. 9 shows a structure of a biasing means of a free end of a coil spring of a foot-operated parking brake of an automobile according to a third embodiment of the present invention.

The urging structure of the free end portion of the coil spring of this embodiment employs a tension coil spring 60 instead of the urging spring 32 of the first embodiment. The same effect as that of the first and second embodiments is achieved by using the tension to reduce the braking loss.

That is, in the configuration of the present embodiment, the free end 11b of the lock coil spring 11 is set with respect to the minimum set value of the interference between the drum 4 and the lock coil spring 11 for satisfying the braking force. The tension coil spring 60 is locked as urging means for applying a predetermined urging force to the coil spring 11 only in the direction in which the coil spring 11 is wound around the drum 4, and the tension is applied to the coil spring 11 in the direction in which the entire coil spring 11 expands. The time lag before the locking coil spring 11 bites into the drum 4 is reduced without restricting the
It is possible to compensate for a decrease in frictional force due to oils and fats between the coil spring 11 and the coil spring 11, and an insufficient fastening force due to deterioration in durability of the free end 11b of the coil spring. As a result, as in the first and second embodiments, the promotion and expansion of the braking loss amount due to the time lag at the time of the braking lock as in the related art can be prevented as much as possible without lowering the lock release function.

[Brief description of the drawings]

FIG. 1 is a side view of a parking brake of an automobile according to a first embodiment of the present invention as viewed from a return spring side.

FIG. 2 is a plan view of a coil spring portion of the parking brake.

FIG. 3 is a sectional view of a drum portion of the parking brake.

FIG. 4 is a perspective view showing a structure of a ring member of the parking brake.

FIG. 5 is a sectional view showing a configuration of a ring member of the parking brake.

FIG. 6 is a side view showing a fixing structure of a coil spring fixing side end of the parking brake.

FIG. 7 is a plan view showing a configuration of an urging means at a free end of a coil spring of a parking brake of an automobile according to a second embodiment of the present invention.

FIG. 8 is a perspective view showing a configuration of an urging means of the second embodiment.

FIG. 9 is a side view showing the configuration of the biasing means at the free end of the coil spring of the foot-operated parking brake of the vehicle according to the third embodiment of the present invention.

[Explanation of symbols]

1 is a mounting bracket, 2 is a vehicle body, 3 is a support shaft, 4 is a drum, 5 is a foot pedal, 10 is a spacer, 11 is a coil spring, 11a is a coil spring fixed end, 11b is a coil spring free end, and 13 is a ring member. , 13b is a vertical wall portion, 13c is a flange portion, 13d is a projection, 13d 'is a projection, 13g is an engagement portion, 32 is an urging spring, 50
Is a leaf spring, and 60 is a tension spring.

Claims (1)

(57) [Scope of request for utility model registration] 1. A foot pedal rotatably supported by a support shaft fixed to a vehicle body-side mounting bracket, a brake cable connected to the foot pedal, a rotatable shaft supported by the support shaft, and A drum portion fixed to the foot pedal, and wound around and held by the drum portion, while rotating the drum portion when the foot pedal is depressed to reduce the binding force, while the tension force of the brake cable causes the drum portion to rotate. In a foot-operated parking brake including a coil spring that increases a binding force by rotation and a fixing member that fixes a fixed end side of the coil spring to the mounting bracket, only a free end side of the coil spring is coiled. There is provided an urging means for pressing and urging with a predetermined elasticity in a spring winding direction. A foot-operated parking brake characterized in that only the free end of the spring is urged in the direction of binding the drum.