JPH0126899Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is an improvement of a disc brake, specifically, a floating caliper type disc brake equipped with a friction pad adjustment device and a piston movement alarm device. To provide an inexpensive disc brake which prevents an increase in the amount of movement of a piston due to wear of friction pads, has a short cylinder sliding part, is compact, lightweight, has excellent vibration resistance, has good riding comfort, and has excellent load holding.

[Problems to be solved by conventional techniques and ideas]

Conventionally, this type of disc brake, for example a floating caliper type disc brake as shown in Fig. 1, has a disc rotor connected to a wheel within a caliper 1 which is slidably attached to a support (not shown) fixed to the vehicle body. A pair of friction pads 3a, 3b for sandwiching the pad 2 from both sides and applying a frictional force to it.
It has a structure in which a piston 4 for pressing and driving the piston 4 is mounted.

In the disc brake described above, the amount of movement of the piston 4 increases as the friction pads 3a and 3b wear out, but if the rear end 4a of the piston 4 is driven leftward relative to the piston seal 6 and falls off, the piston 4 If the piston seal 6 is not returned, oil leakage may occur, and if the piston seal 6 is returned forcibly, the piston seal 6 may be damaged. Therefore, conventionally, the length A of the piston 4 and the cylinder 5 in which it is fitted from the rear end 4a of the piston 4 to the piston seal 6 during brake operation is set to be 22 times or more the thickness B of the friction pads 3a and 3b, that is, I thought it would be preferable for the relationship to be A≧2B.

Therefore, if A is increased, the volume of the caliper increases, which increases the volume and weight of the brake as a whole, and there are problems such as increased processing costs and higher costs.

[Means for solving problems]

The present invention has been made to solve this problem, and includes a friction pad adjustment device in which a friction pad on the side that is pressed by the piston and a friction pad on the opposite side are attached to a caliper via an adjustment screw, and a friction pad adjustment device. This invention has achieved the desired results by providing a disc brake equipped with a piston movement warning device that uses an indicator circuit to warn of excessive movement of the piston due to wear of the pads. That is, the gist of the present invention is to provide direct-acting friction pads and indirect-acting friction pads disposed on both sides of a rotatable disc rotor, and first and second friction pads straddling the friction pads and the disc rotor, respectively, on both sides of the disc rotor. a caliper having a second arm and slidable in the axial direction of the disc rotor; a piston housed in the first arm of the caliper; the piston presses the adjacent directly actuated friction pad against the adjacent surface of one side of the disc rotor, and the reaction force causes the caliper to move in the axial direction of the disc rotor. In a disc brake of the type in which an adjustment device slidably engaged with the second arm of the caliper presses the indirectly actuated friction pad against the opposite surface of the disc rotor, the piston or a member that moves integrally therewith. and a caliper or a member that moves integrally with the caliper, and one of them is provided with an electric contactor operator, and the other is provided with a member that comes into contact with the operator, and the amount of movement of the piston exceeds a certain value. An indicator circuit is provided to issue an alarm when the operator collides with the contact member, detects an excessive amount of movement of the piston, adjusts wear of the friction pad with the adjustment device, and returns the piston to its original position. This disc brake is characterized in that the length of the sliding surface of the caliper cylinder is reduced by returning it to .

[Effect]

In other words, the disc brake of the present invention can compensate for the wear of the friction pads using the adjusting screw and restore the piston position to its initial state, and the indicator circuit can prevent the piston from moving too far and falling off from the piston seal. It is equipped with a function that alerts the driver to this excessive sliding stroke and prompts the driver to compensate using the adjustment screw described above, reducing the A dimension of the disc brake to the necessary minimum regardless of the thickness B of the friction pad. I can do it.

As a result, the A dimension of disc brakes used in general automobiles can be extremely reduced to 1/3 to 1/5 of the conventional size.

As described above, the disc brake of the present invention prevents an increase in the sliding stroke of the piston due to wear of the friction pads, and allows the piston, the caliper cylinder, and the entire brake to be manufactured compactly, lightweight, and inexpensively.

〔Example〕

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The disc brake of the present invention will be explained below based on embodiments shown in the drawings.

As shown in FIG. 2, the friction pad 3a on the opposite cylinder side of the caliper 1 is supported via an adjustment device 7 screwed onto the second arm, and the friction pad 3a when the brake is not activated is fixed to prevent wear of the friction pads 3a and 3b. ,3b
The gap between the piston 4 and the rotor 2 can be adjusted to an appropriate value, and the amount of movement of the piston 4 increases due to wear of the friction pads 3a and 3b. When the length A′ approaches zero or reaches the amount of adjustment,
A projection 4b protruding from the side of the pressing end of the piston 4
is the operator 8a of the switch 8 placed on the caliper 1.
and a piston movement amount warning device configured to turn on the switch 8 in response to the friction pad, close the indicator circuit 9, and light up a warning lamp 10 on the driver's seat to prompt the driver to adjust the friction pad. There is.

The switch 8 of this piston movement alarm device is installed in a hole 11 made in the caliper 1 as shown in FIG. The interval W during brake activation is set to an appropriate value less than the A' dimension (A'>W), and when the A' dimension approaches zero due to wear of the friction pads 3a and 3b, the switch is activated by the protrusion 4b of the piston 4. 8 is designed to surely turn ON and light up the warning lamp 10.

As mentioned above, the disc brake of the present invention can be significantly reduced in size compared to the conventional disc brake of dimension A', and as a result, the brake as a whole can be made compact, lightweight, and inexpensive.

Note that a groove 7a is provided in the head of the adjustment screw 7 of the piston movement adjustment device, and the friction pads 3a, 3b
When the A' dimension approaches zero due to wear and the driver's seat warning lamp 10 lights up, the adjustment screw 7 can be easily turned by inserting a screwdriver or the like through the window hole of the tire's wheel disc.

Further, this adjustment is a simple operation of tightening the adjusting screw 7 until the piston 4 comes into contact with the bottom surface of the cylinder 5, and then returning the adjusting screw 7 slightly to prevent the rotor 2 from being dragged when the brake is not activated. Completed by

[Effect of idea]

By reducing the length of the sliding surface of the caliper cylinder, the disc brake of the present invention is compact in terms of space and lightweight, which reduces unsprung weight, improves vibration characteristics, and improves running performance. It has great practical value as it can be manufactured at low cost and has space design advantages.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the operating state of a conventional disc brake, and FIG. 2 is a sectional view showing the operating state of the disc brake of the present invention. 1...Caliper, 3a, 3b...Friction pad,
4...Piston, 5...Cylinder, 6...Piston seal, 7...Piston travel adjustment device, 8...
...Switch, 9...Indicator circuit, 10...
...Warning light.

Claims (1)

[Claims for Utility Model Registration] (1) Direct-acting friction pads and indirect-acting friction pads disposed on both sides of a rotatable disc rotor, and friction pads straddling the friction pads and the disc rotor on both sides of the disc rotor, respectively. a caliper having first and second arms and slidable in the axial direction of the disc rotor;
a piston housed in the first arm of the caliper, and an adjustment device threadedly engaged with the second arm to displace the indirectly actuated friction pad from the second arm, the pistons being adjacent to each other; The directly actuated friction pad is pressed against the adjacent surface of one side of the disc rotor, and as a result of the reaction, the caliper slides in the axial direction of the disc rotor, and the adjustment device screwed into the second arm of the caliper is moved between the two sides of the disc rotor. In a disc brake of the type in which the operating friction pad is pressed against the opposite surface of the disc rotor, an electric contactor is operated on either the piston or a member that moves integrally therewith, and the caliper or a member that moves integrally therewith. A member is provided on either side of the piston that comes into contact with the operator, and an indicator circuit is provided that issues an alarm when the operator collides with the abutting member when the amount of movement of the piston exceeds a certain value. , the length of the sliding surface of the caliper cylinder is reduced by detecting an excessive amount of movement of the piston and adjusting the wear of the friction pad with the adjustment device to return the piston to its original position. disc brake. (2) A disk according to claim 1, in which the length of the sliding surface of the caliper cylinder is not more than 1/2 of the total maximum allowable wear amount of the lining of the direct action friction pad and the indirect action friction pad. brake. (3) A disk according to claim 1 of the utility model registration, in which when the amount of movement of the piston becomes excessive, the operator comes into contact with the piston or a member that moves integrally with the piston, thereby preventing the piston from falling off. brake.