JPH0539222Y2 - - Google Patents

Description

[Detailed explanation of the invention] A. Purpose of the invention (industrial application field) The invention detects when the pads of disc brakes have worn out and reached the permissible limit, and alerts the driver. The present invention relates to a wear detection device for a pad that emits light, and more particularly, to a mounting structure for this wear detection device.

(Prior Art) A disc brake is configured to perform braking by pressing a rotating rotor fixed to a wheel between inner and outer butts disposed at opposing positions. These inner and outer pads gradually wear out due to use of the disc brake, and when the amount of wear increases, the braking function deteriorates, making it dangerous to drive the vehicle. For this reason, devices are often used that detect when the wear of the pads has reached its limit and issue a warning to the driver.

As such a device, for example,
Some are disclosed in the back of No. 42665, and others are disclosed in Utility Model Application Publication No. 62-62036.

The wear detector (probe) disclosed in Utility Model Publication No. 58-42665 is a back plate of the pad (packing plate).
It is attached to the through hole formed in the. For this reason,
A cylindrical holding member having a non-return claw is inserted and fixed into the through hole, and the non-return claw engages with the engagement step of the probe inserted into the holding member to hold the probe. ing.

In the device disclosed in Utility Model Application No. 62-62036,
For example, as shown in FIG. 6, a wear detector 11 for detecting wear of the inner pad is attached to the back plate 6 of the inner pad 4 with its front end protruding toward the rotor 1 side (this is referred to as the front side). It is being This wear detection tool 11 consists of a detection tool body 12 made of an insulator formed into a substantially cylindrical shape, and a metal wire 13 embedded in the detection tool body 12 and connected to a conductive wire 14. The detector body 12 has a cylindrical portion 12a located on the front side.
and a flange portion 12b which is integrally connected to the rear side of the cylindrical portion 12a and has a larger outer diameter. An annular groove 12d is formed in the center of the cylindrical portion 12a, and a collar (ring-shaped member) 15 is attached within this annular groove 12d.

On the other hand, a through hole is formed in the back plate 6 of the inner pad, into which a tube-shaped locking tool 56 is press-fitted. A portion of the locking tool 56 is cut and raised to form a locking claw 57 that projects inward and forward. This locking claw 57 has flexibility (elasticity), and when the detection tool 11 is inserted into the locking tool 56 from the opposite side (rear side) of the rotor 1, this locking claw 57 is moved outward. It flexes to allow this insertion.

In this way, the shoulder 12c of the flange portion 12b
When the wear detection tool 11 is inserted to the position (predetermined position) where the locking tool 56 almost contacts the rear end of the locking tool 56, the locking claw 57 is inserted into the collar 15 attached to the engagement recess 12d of the detection tool body 12. The detection tool 11 is held at the predetermined position by protruding into and engaging with the detection tool 11.

In a device having such a configuration, when the inner pad 4 is worn to the wear limit, the front end of the detection tool 11 comes into contact with the rotating rotor 1 and is damaged, and the metal wire 13 inside is cut. For this reason,
An alarm circuit connected to this metal wire 13 is activated and an alarm is issued. Note that the detector body 12 is arranged so that the metal wire 13 is cut by the rotor 11.
is made of a soft material such as resin, and the metal wire 13
are made from brittle materials such as sintered metal.

(Problem to be Solved by the Invention) The wear detection tool 11 configured as described above is held by the locking pawl 57 engaging with the collar 15, but due to the dimensional tolerance of the engaging portion, the wear detection tool 11 is It is inevitable that play (play caused by the clearance shown by dimension "C" in the figure) will occur. For this reason, the detection tool 11 rattles within the locking tool 56 due to vibrations during driving, and the detection tool body 12 made of a soft material rubs against the metal locking tool 56 and wears out. There is a problem in that there is a risk of damage or damage.

Further, when inserting the wear detection tool 11, the wear detection tool 11 is pushed in the opposite direction in the radial direction by the elastic deformation force of the locking pawl 57. At this time, the annular groove 12
The collar 15 attached in the cylindrical part 12a
If it protrudes more radially outward, this collar 1
5 is caught on the rear end of the locking tool 56,
A problem may arise that it is difficult to insert the wear detection tool 11.

The present invention has been developed in view of these problems, and has developed a mounting structure for a brake pad wear detector that does not rattle due to vibrations while the vehicle is running and is easy to install. The purpose is to provide.

B. Structure of the invention (Means for solving the problem) In order to achieve the above object, in the present invention, a through hole is formed in the support plate, for example, the back plate of the brake pad, and a tube-shaped locking member is inserted into the through hole. is inserted and fixed, and the wear detection device is attached with the front end protruding from this locking member.An annular groove is formed on the outer periphery of the wear detection device, and a ring member is attached to this annular groove. A spacer member is attached to the outer periphery of the wear detection device to cover the ring-shaped member.Here, an opening is formed in the spacer member corresponding to the position of the ring-shaped member, and a part of the peripheral wall is formed in the locking member. A flexible locking pawl is formed by cutting it up in the front direction.

(Function) In the above wear detector mounting structure, the wear detector is inserted into the locking member from the rear with the ring member and spacer member attached, and the wear detector is attached to the through hole of the support plate. However, during this insertion, the locking pawl of the locking member bends to allow this insertion, and when the wear detector is inserted to the specified position, the locking pawl protrudes into the opening of the spacer member and prevents wear. Lock and hold the detection tool in a predetermined position.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

FIGS. 1 and 2 show a disc brake using the brake pad wear detector mounting structure according to the present invention. However, FIG. 2 shows this brake with the wear detector removed.
A rotor 1 is coupled to an axle 3 together with a wheel hub 2 for rotation, and an inner pad 4 and an outer pad 5 are disposed at opposing positions on the inside and outside of the rotor 1, supported by back plates 6 and 7, respectively. The caliper 8 is supported by a pair of rail portions 9a provided on an anchor plate 9 so as to be slidable in the direction of the axle 3, and is of a floating type. The caliper 8 has an arm bent portion 8 extending outward.
a, which abuts against the back plate 7 of the outer pad 5. Furthermore, two cylinders 8b are formed inside the caliper 8.
A piston 10 is slidably inserted into each of the inner pads b, and the front end of the piston 10 is in contact with the back plate 6 of the inner pad 4.

In the disc brake configured as described above, during braking, pressurized hydraulic oil is injected into the cylinder 8b, and the piston 10 is pushed outward by the hydraulic pressure, and the floating caliper 8 is moved by the reaction force. slid inward. With this, the inner pad 4 is connected to the rotor 1.
The outer pad 5 is pressed against the outer surface of the rotor 1, and a braking force that prevents the rotor 1 from rotating is generated.

The wear detection tool 11 is almost the same as the conventional detection tool shown in FIG. 6, and the same parts will be described with the same numbers.

First, the mounting structure of the wear detection tool 11 for the inner pad 4 will be explained. This wear detection tool 11
As shown in FIG. 3, the detector has a detector body 12 made of an insulating material such as a relatively soft resin.
A metal wire 13 made of a relatively brittle material such as sintered metal is provided inside the body 12 and extends to the front end and is connected to a conductive wire 14 at the rear. The detection tool body 12 is
It has a cylindrical part 12a at the front and a flange part 12b having a larger diameter than the cylindrical part 12a at the rear,
The cylindrical portion 12a has an annular groove 12d approximately in the center thereof.

A collar (ring-shaped member) 1 is fitted in the annular groove 12d.
4, has flanges 15a that rise outward on both sides in the width direction, and is cut at one point on the circumference. This allows the cut portion 15b to be expanded to overcome the cylindrical portion 12a, and the collar 15 to be installed in the annular groove 12d.

Further, in this way, the collar 1 is placed inside the annular groove 12d.
5 is attached, a spacer 16 is attached to cover the cylindrical portion 12a. As shown in FIG. 5, this spacer 16 is a cylindrical member cut at one point, and has an opening 16a and a notch 16 on the opposite side in the radial direction to the cut section 16c.
b is formed. The inner diameter of this spacer 16 is smaller than the outer diameter of the cylindrical portion 12a, and the spacer 16 is attached to the cylindrical portion 12a by expanding the cut portion 16c, and is fixed onto the cylindrical portion 12a by its elastic force. In this attached state, the opening 16a is connected to the collar 15.
The notch 16b is located at the front end.

Note that, as shown in FIG. 1, the conductive wire 14 is connected in series with the outer pad wear detector 11, the power source 21, and the relay 22, and constitutes a part of the alarm circuit 20.

This wear detection tool 11 for the inner pad is attached to a through hole 6a formed in a portion of the back plate 6 of the inner pad where the piston 10 does not come into contact. However, a tube-shaped locking tool 56 is fitted and fixed in the through hole 6a, and the wear detection tool 11 is inserted and attached into this locking tool 56. A portion of the substantially central portion of the locking tool 56 is cut inward and forward to form a flexible locking pawl 57.

Therefore, when the locking pawl 57 and the notch 16b are aligned and the wear detection tool 11 having the above structure is inserted into the locking tool 56, the locking pawl 57 is elastically deformed outward and the wear detection tool 11 insertion is allowed.
At this time, since the collar 15 is covered by the spacer 16, there is no fear that the collar 15 will get caught on the rear end of the locking tool 56, and this insertion can be performed smoothly. Note that during this insertion, the notch 16b aligned as described above serves as a guide for the locking claw 57, and the wear detection tool 11
When the locking claw 57 is inserted into the predetermined position (the position in the inserted state as shown in FIG. come into contact with. Thereby, the locking pawl 57 engages with the spacer 16, and the wear detection tool 11 is engaged and held at this predetermined position.

In this example, with the engaging claw 57 protruding into the opening 16a, the inner surface of the base of the locking claw 57 is in the opening 1.
The spacer 16 is pressed inwardly and rearward by the elastic force of the locking claw 57 when it comes into contact with the rear edge 16d of the locking claw 6a. Therefore, the tip of the locking claw 57 is attached to the collar 1.
5 and presses the spacer 16 backward, so that the wear detection tool 11 is firmly fixed and held. Therefore, even if the vehicle is subjected to vibrations while the vehicle is running, the wear detection tool 11 will not rattle, and the detection tool body 12 will not be worn out due to vibrations while the vehicle is running.

Moreover, even if the detection tool 11 shakes, the detection tool body 12 is covered by the spacer 16, and the spacer 16 and the locking tool 56 will only rub against each other due to this play. Here, both the spacer 16 and the locking tool 56 are made of metal, so even if such looseness occurs, the problem of wear is unlikely to occur.

Wear detection device 1 installed as above
1, when the inner pad 4 reaches its wear limit,
The front end of the detector body 12 contacts the rotor 1 and this portion is destroyed. This part has a metal wire 13
is embedded, the metal wire 13 is cut when the front part of the body 12 is broken, cutting off the power supply from the power supply 21 to the solenoid 22b of the relay 22, and demagnetizing the solenoid 22b. As a result, the switch body 22a moves upward in the figure to connect the terminals 23a and 23b, and the alarm lamp 25 is lit by the current from the power source 24, notifying the driver that the pad has worn to its limit.

The wear detector 11 for detecting the wear of the outer pad is the same as the wear detector 1 for the inner pad.
1, and is held by a support plate 9a fixed to an anchor plate 9. In this state, the front end of the wear detector 11 protrudes toward the caliper 8, and a pressing plate 8c fixed to the caliper 8 is positioned beside this front end. For this reason, when the outer pad is worn to the limit and the caliper 8 is moved inward in response to this,
The pressing plate 8c presses the front end of the detection tool 11 to break it and cut the metal wire 13 inside.

C. Effect of the invention As explained above, according to the invention, an annular groove is formed on the outer periphery of the wear detection tool, a ring member is attached to this annular groove, and the ring member is further covered with the outer periphery of the wear detection tool. Since the spacer member is attached, when the wear detection tool is inserted into the locking member from the rear, the annular member can be inserted smoothly without being caught by the locking member. Further, an opening is formed in the spacer member corresponding to the position of the annular member, and a part of the peripheral wall of the locking member is cut and raised inwardly and forwardly to form a flexible locking claw. Therefore, when inserting the wear detector,
The locking pawl of the locking member bends to allow this insertion, and when the wear detector is inserted to the specified position, the locking pawl protrudes into the opening of the spacer member and locks the wear detector in the specified position. Stop and hold. In this locked and held state, the detection tool is covered by the spacer member, and even if the detection tool wobbles, the spacer member and the locking member will just rub against each other, reducing the problem of wear on the detection tool. Does not occur.

In addition, as explained in the embodiment, with the locking claw protruding into the opening, the elastic force of the locking claw presses the rear edge of the opening backward to fix the detection tool to the locking member. can be retained. In this way, the detection tool will not rattle even when subjected to vibrations, and the problem of wear can be further suppressed.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a disc brake with a wear detector attached using the mounting structure of the present invention, Figure 2 is a side view of the disc brake, and Figure 3 is a diagram showing the mounting structure of the wear detector for inner pads. FIGS. 4 and 5 are perspective views showing a collar and a spacer, respectively, and FIG. 6 is a sectional view showing a conventional mounting structure for a wear detector. 1...Rotor, 4...Inner pad, 6,
7... Back plate, 8... Caliper, 11... Wear detector, 12... Detector body, 12b... Flange portion, 13... Metal wire, 15... Collar, 16...
…Spacer.

Claims (1)

[Claims for Utility Model Registration] The front end is attached to a through hole formed in a support plate with the front end protruding, and the front end is attached to a member that moves in response to the wear of the pad when the pad wears to the wear limit. A wear detection device for brake pads that comes into contact with the wear detection device has a structure for attaching the detection device to the support plate, the tube-shaped locking member being inserted and fixed into the through hole, and the wear detection device a ring-shaped member attached to an annular groove formed on the outer periphery of the abrasion detection device; and a spacer member attached to the outer periphery of the wear detection device so as to cover the ring-shaped member, and the spacer member includes a ring-shaped member at a position of the ring-shaped member. A corresponding opening is formed, and a part of the peripheral wall of the locking member is cut and raised inwardly and forwardly to form a flexible locking pawl, and the ring-shaped member and the spacer member are attached to the locking member. When the wear detector is inserted into the locking member from behind in the state where the wear detector is inserted, the locking pawl is bent to allow this insertion, and when the wear detector is inserted to a predetermined position, the locking pawl is inserted into the opening. A brake pad wear detection tool mounting structure, characterized in that the wear detection tool is locked and held at the predetermined position by the locking pawl that protrudes inward.