JPH0134759Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a drum brake for a vehicle.

[Prior Art] A drum brake of a vehicle is designed to maintain the brake operating state by a hand lever from the vehicle interior when the vehicle is parked. For this reason, a remote control cable is connected between the hand lever and the parking lever provided inside the drum brake, but the tension of this cable is controlled by a connecting member similar to a turnbuckle in the middle of the cable. Adjustments are made by tightening the nut to the mark provided on the connecting member, but this can cause variations in the amount of hand lever operation (pulling allowance) when applying the parking brake due to errors in the mounting position of the hand lever. If the cable is too tensioned, the brake shoe may be dragged against the brake drum, causing uneven wear of the lining, while if the cable tension is loose, the hand lever will have a large amount of pull. Not only that, but also sufficient braking force may not be obtained. Of course, the turnbuckle can be tightened by repeatedly operating the hand lever to obtain a proper pull, but this requires a lot of time and effort.

[Problems to be Solved by the Invention] In view of the above-mentioned problems, the purpose of the invention is to provide a drum brake that is easy to adjust and can provide an appropriate pull amount to the parking brake hand lever by tightening the turnbuckle. It is in.

[Means for Solving the Problems] In order to achieve the above object, the structure of the present invention is such that a strut is interposed between the parking lever that is axially supported on one brake shoe and the other brake shoe, A pin hole is provided in the parking lever and the web of one brake shoe that matches when the brake is released, and a lock pin is provided in one brake shoe that can be displaced between a position where it engages with both pin holes and a position where it does not engage. I supported it.

[Operation] When the lock pin 20 is engaged with the pin hole in the web of the brake shoe 4 and the pin hole in the parking lever 23, the parking lever 23 is locked, so the parking lever 23 and the hand lever 15 are locked.
It is now possible to accurately adjust the length (tension) of the cable connecting the hand lever 15.
An appropriate delivery charge will be set.

[Embodiment of the invention] To explain the invention based on an embodiment, as shown in FIG. be done. The other end of this cable 7 passes through the back plate 5, is pulled out to the outside of the drum brake 2, is spanned over a connecting member 10 having an arcuate groove, and is then connected to the parking lever of the drum brake 2 on the opposite side. Concatenated. The back plate 5 is fixedly supported at the end of the axle case 6.

In order to obtain braking force by pulling both parking levers 23, a bolt 8 is inserted through and supported by the connecting member 10, and is connected with a nut 9 so as not to come off. This bolt 8 is connected via a cable 12 to a hand lever 15 rotatably supported by a support shaft 14 on a bracket 13 fixed to the vehicle interior. The raised state of the hand lever 15 when the parking brake is applied is maintained by a well-known latch mechanism.

The tension of the cables 7 and 12 is adjusted by tightening the nuts 9, but simply tightening the nuts 9 to a predetermined position may cause errors in the mounting position of the hand lever 15, the assembly condition of the parking lever 23, etc. As a result, the tension of the cable varies, and when the tension of the cable is loose, the pulling allowance of the hand lever 15 increases.

Therefore, the present invention fixes the brake shoe 4 and the brake lever 23 in a predetermined state, and fixes the parking lever 23 to the brake shoe 4 with a pin.
In this state, the tension of the cable is adjusted by tightening the nut 9.

As shown in FIG. 2, the drum brake has a wheel cylinder 16 and an anchor member 21 fixedly supported facing each other on a back plate 5 having an axle hole 24, and a pair of left and right brake cylinders having a lining 18 between them. The user 4 is biased and engaged by a return spring (not shown). When pressurized fluid is supplied to the wheel cylinders 16, the pair of brake shoes 4 are pushed apart using the lower ends that engage the anchor member 21 as a fulcrum, and are pressed against the inner circumferential surface of the brake drum for control. It is designed to generate power.

In order to obtain an appropriate gap with the brake drum when the brake is released, a strut 26 is interposed between the pair of brake shoes 4 and is connected to the strut 26 by a bolt having a ratchet wheel 25 so as to be adjustable in extension and contraction. A parking lever 23 is supported by a pin 17 at the upper end of the right brake shoe 4, and its intermediate portion is engaged with a strut 25, and a protrusion 19a provided at the lower end directly supports the lining 18. It is pressed against the rim of the brake shoe.

An end of the cable 7 is connected to the lower end 19b of the parking lever 23. This cable 7 is a cylindrical guide member 2 formed integrally with an anchor member 21.
1a and is drawn out from a hole provided in the back plate 5. Projection piece 19a of parking lever 23
A pin hole 30 is provided in the brake shoe 4, and a pin hole is provided in the brake shoe 4 that overlaps with the pin hole 30, so that the two are connected from the outside with a lock pin.

As shown in FIG. 3, a cup-shaped bracket 32 is connected to the web of the brake shoe 4 by welding or the like, and a lock pin 20 is inserted and supported through a pin hole provided in the bracket 32 and the brake shoe 4. A spring 31 is interposed between the protruding piece 20a of the pin 20 and the brake shoe 4. A protrusion 20 extending in the radial direction is provided at the end of the lock pin 20.
b is provided, and this protrusion 20b is provided with a lock pin 20
If the pin 20 is rotated so that it aligns with the slit that crosses the pin hole of the bracket 32, it can be moved to the left in FIG.
It is designed to be inserted into the pin hole 30 of No. 3.
To carry out this operation, a tool insertion hole 29 is provided in the back plate 5, which is normally closed by a grommet 28.

Next, the operation of the device of the present invention will be explained. First, when the brake is released, the brake shoe 4
and the brake drum with the strut 26.
After adjusting the parking lever 23 and brake shoe 4 properly by extending and contracting them, lock the parking lever 23 and the brake shoe 4
Fix by. That is, in FIG. 3, the grommet 28 is removed, a screwdriver or the like is engaged with a groove (not shown) formed in the end of the lock pin 20 through the tool insertion hole 29, and the lock pin 20 is rotated to remove the protrusion 20b and the bracket 32. When the lock pin 20 is inserted into the pin hole 30 of the parking lever 23, the lock pin 20 is inserted into the pin hole 30 of the parking lever 23. When the lock pin 20 is rotated, the protruding piece 20b comes into contact with the inner wall of the bracket 32, and the lock pin 20 is maintained inserted into the pin hole 30.

In this way, if the brake levers 23 of the left and right drum brakes are fixed to the brake shoe 4 in FIG. Tighten cables 7 and 12. At this time, the hand lever 15 is tilted to the brake release state. Then, by returning the nut 9 by a predetermined amount of rotation, the cable 7 will be loosened by that amount, and by operating the pin 20 in the opposite manner to the above case and pulling it out from the pin hole 30, the cable will be properly tensioned.

Therefore, when the hand lever 15 is pulled up by a predetermined amount, the parking lever 23 is rotated clockwise about the pin 17 in FIG. 2 via the cables 12 and 7.
At the same time, the left brake shoe 4 is pressed against the brake drum via the strut 26 by the intermediate portion of the strut 26, and at the same time, the pin 17 of the parking lever 23 is pressed against the engagement portion of the parking lever 23 and the strut 26 as a fulcrum. Right brake shoe 4
is pressed against the brake drum and generates braking force.

FIG. 4 shows an embodiment in which the parking lever 23 is disposed between the back plate 5 and the brake shoe 4. As shown in FIG. When a driver is engaged with the tip of the lock pin 20 through the tool insertion hole 29 and the lock pin 20 is rotated to align the protrusion 20b with the slit across the pin hole of the brake shoe 4, the force of the spring 31 will cause the lock pin to close. 20 is inserted into the pin hole 30 of the parking lever 23, and both are fixed.

[Effects of the invention] As described above, the present invention has a strut interposed between the parking lever that is shaft-supported on one brake shoe and the other brake shoe, and the web of the parking lever and one brake shoe. A lock pin is provided on one brake shoe that can be moved between a position where it engages with both pin holes and a position where it does not engage, so the lock pin can be connected to the parking lever and the brake. The parking lever is locked by engaging each pin hole in the parking brake hand lever, and the tension of the cable is adjusted by tightening the nut of the cable connecting member in the parking brake operating mechanism. You can get cash on delivery. If the lock pin is released after adjusting the pull allowance, the parking brake can be operated and the worker can
It can be easily adjusted by humans, and there is no variation.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a schematic configuration of the parking brake operating mechanism, FIG. 2 is a front view of the drum brake according to the present invention, and FIG. 3 is a side sectional view showing the main parts of the drum brake according to the present invention. , FIG. 4 is a side sectional view showing the same modified embodiment. 2...Drum brake, 3...Brake drum, 4...Brake shoe, 5...Back plate, 7,1
2...Cable, 8...Bolt, 9...Natsuto,
10... Connection member, 15... Hand lever, 20
... Lock pin, 23 ... Parking lever, 2
8... Grommet, 29... Tool insertion hole, 30...
...pin hole.

Claims (1)

[Scope of utility model registration request] A strut is interposed between a parking lever that is axially supported on one brake shoe and the other brake shoe, and a pin hole is provided in the parking lever and the web of one brake shoe to match when the brake is released. A drum brake characterized in that one brake shoe supports a lock pin that is movable between a position in which it engages with both pin holes and a position in which it does not engage.