JPH0716912Y2 - Pad brake pad lining replacement time warning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial field of application) The present invention relates to a replacement timing warning device for a pad lining in a disc brake.

(Prior Art) Recently, disc brakes have been widely used in various fields such as railway vehicles, automobiles, winches, and the like. Here, as an example, description will be made for an automobile disc brake, and this automobile disc brake, for example, an opposed piston type disc brake, is shown in FIG.
The brake pads 3,3 operated by 1,2 are configured to be pressed against the rotary disc 4 from both sides for braking.

The brake pad 3 has a back metal 3a and a lining 3b.
The back metal 3a is usually made of a single metal of a cast iron block, and the lining 3b varies depending on each manufacturer, but several kinds of substances are mixed and solidified. It is made of a material (the conditions for selecting this lining material are that the friction coefficient and wear resistance are large, the rotating disk 4 is not damaged, the heat conduction is good, and no creaking noise is produced during braking).

Therefore, the pad lining 3b has a usage limit (usually 3 m
This lining 3b needs to be replaced when it wears down to a thickness of about m).
All of 3b is worn away, and the back metal 3a comes into contact with the rotating disk 4 to be in a so-called metal touch state, which damages the rotating disk 4. In this case, repairing the rotary disk 4 requires a great deal of expense and labor.

(Problems to be solved by the invention) By the way, in the case of automobiles, for example, there is a legal vehicle inspection system and regular inspection system that are regularly inspected and maintained, but it is necessary to know the remaining amount of the pad lining 3b accurately. There is no other way than to remove the brake pad 3 and measure.
In addition, since the attachment / detachment of the pad 3 is an important safety component,
Only qualified personnel such as mechanics can do this.

Therefore, even if a pad that is still usable is replaced at the time of vehicle inspection or regular inspection, or even if the maintenance shop decides to continue using it, abnormal wear due to usage conditions cannot be known to the driver. The current situation is that a metallic squeaking noise (metal touch sound) is emitted during braking, and is noticed abnormally. In particular, some foreign countries do not have a vehicle inspection system or a regular inspection system. In this case, a metal touch sound or a bad brake will cause the abnormality to occur and be repaired.

The present invention has been devised to solve the above-mentioned problems, and the purpose thereof is to automatically issue a replacement timing warning signal of the pad lining to the driver when the pad lining wears to the limit of use. An object of the present invention is to provide a pad lining replacement timing warning device in a disc brake configured as described above.

[Constitution of device]

(Means for Solving the Problem) In order to achieve the above object, the pad lining replacement timing warning device for a disc brake of the present invention has a pad lining provided for each of a plurality of disc brakes and crimped to a rotating disc. A brake pad, an electrode electrically connected to each of the brake pads and fitted so as to come into contact with the rotating disk when the pad lining is worn to the limit of use, and a warning signal such as a light or a sound to a driver. And an alarm device that emits a signal and is provided between the electrodes and the alarm device, and is connectable to the plurality of electrodes at the same time, and wiring is provided to activate the alarm device when at least one of the electrodes contacts the rotating disk. The first movable contact that is connected and the electrode that can be connected to any one of the plurality of electrodes are connected to the rotating disk. A switch configured to be switchable between a second movable contact hard-wired to activate the alarm device when the contact is made.

(Operation) According to the pad lining replacement timing warning device having the above-described configuration, when the pad lining is worn to the limit of its use and the tip of the electrode comes into contact with the rotating disk, a ground current flows and the alarm device replaces the pad lining. A timing warning signal is issued to the driver, and the driver can know when the pad lining should be replaced by catching the warning signal.

(Embodiment) A first embodiment of the present invention will be specifically described below with reference to FIGS. 1 and 2. FIG. 1 is a sectional view of an essential part of a brake pad assembly equipped with a pad lining replacement timing warning device according to the present invention. The brake pads 3,3 that are crimped to the rotating disc 4 from both sides are the same as the conventional back metal 3a. It consists of a lining 3b. Each pad 3,3 has a predetermined depth t (usually 3mm from the back metal 3a side to the lining 3b side).
The horizontal hole 5 is formed so as to reach up to the position), and the vertical hole 6 is formed so as to be orthogonally connected to the horizontal hole 5 from the upper end portion of the back metal 3a. The horizontal electrode 7 electrically insulated by the insulator bush 7a is press-fitted and fixed in the lateral hole 5, and the vertical electrode 8 electrically insulated by the insulator bush 8a is press-fitted and fixed in the vertical hole 6. ing.

The press-fitting relationship between the lateral electrode 7 and the insulator bush 7a is as follows.
In order to prevent a ground current, which will be described later, from flowing when the pad lining 3b is normal, the inner end face of the lateral electrode 7 is in a state of being retracted from the inner end face of the insulator bush 7a by a small amount e as shown in FIG. The bush 7a has a cutout portion obtained by contacting the vertical electrode 8 and the horizontal electrode 7 as shown in the drawing, and is press-fitted so that the tip of the vertical electrode 8 is inserted into the horizontal electrode 5. The quality of contact between the vertical and horizontal electrodes 8 and 7 can be determined by conducting an electrical continuity test between the horizontal electrodes 7 and the vertical electrodes 8.

A terminal screw 9 for connecting a ground wire 10 is screwed onto the upper end of the vertical electrode 8. The earth wire 10 is wired and connected through a rotary switch 11 provided in the operator's cab to an alarm 12 composed of a warning lamp as shown in FIG.
Is connected to the cathode of the battery 13. Since two brake pads 3 are usually paired with one rotating disc 4, the pair of pads 3, 3 is connected between the terminal screws 9, 9 by a ground wire 10 as shown in the figure. The connection is hardwired so that a warning signal can be issued when either the left or right pad lining 3b wears to the limit of use.

FIG. 2 shows a wiring diagram of a pad lining replacement timing warning device in the case of a four-wheel disc brake, which is connected between the alarm device 12 and each pad 3 of the four-wheel disc brakes A through a rotary. The switch 11 has four fixed contacts S on the switch body side, which are connected to the pad electrodes 8 of the four-wheel disc brakes A to D by the ground wires 10a to 10d, and which are equally distributed in the rotor rotating direction, and are manually operated. The second movable contact T (moving contact for detection) located in the middle of the fixed contact S on the main body side is connected to the first movable contact R (4 contacts) at which the movable contact on the rotor side simultaneously contacts the fixed contact S on the main body side. An alarm device 12 consisting of a warning lamp is wired and connected by a lead wire 14 between the conductive terminal O of the rotor side 5 contacts and the battery 13 as shown in the figure. Although not shown in the drawing, in the case of a two-wheel disc brake, the fixed contact S on the main body side of the rotary switch 11 has two contacts, and the movable contact on the rotor side first contacts the fixed contact S on the main body at the same time. The R (2 contacts) is added with one second movable contact T (detection movable contact) located in the middle of the main assembly side fixed contact S to form three contacts.

During normal operation, the fixed contact S on the main body side of the rotary switch 11 and the movable contact R on the rotor side (first movable contact R) are in contact with each other as shown in FIG. The plus-side rotor-side detection movable contact (second movable contact T) is located in the middle of the main body-side fixed contact S and is in a non-contact state in which it is not electrically conducted. In this state, if the pad lining 3b of any of the four-wheel disc brakes A to D is worn to the limit of use and the tip of the pad lateral electrode 7 comes into contact with the rotating disc 4, the shorted electrodes 8 and 7 and the battery A ground current flows through the rotary switch 11 and the alarm device 12 between the alarm switch 12 and the alarm 13 when the pad lining 3b is replaced with a warning signal (a lighting signal when the alarm device 12 is a warning lamp,
When the alarm device 12 is a warning alarm device such as a buzzer, a warning sound signal) is emitted, and the driver catches the lighting or acoustic warning signal, so that the pad lining 3b somewhere. You can see that is reaching the limit of use.

However, in this state, it is unknown which pad lining 3b of the four-wheel disc brakes A to D is abnormal. Therefore, when the driver rotates the rotor of the rotary switch 11 little by little, the warning signal is temporarily disappeared due to the contact separation between the rotor side movable contact (first movable contact R) and the main body side fixed contact S, but When the detection movable contact (second movable contact T) sequentially contacts the main body side fixed contact S, a warning signal is output between one or a plurality of contacts. Therefore, by detecting the position where this warning signal is issued, it is possible to determine which set of the pad linings 3b in the four-wheel disc brakes A to D is abnormally worn, that is, at the time of replacement. In this case, the judgment is made by using the pads 3 and 3 of a set of two as one unit, and it is possible to judge which set of the pad linings of the four-wheel disc brakes A to D is worn. It cannot be determined whether the left or right pad lining 3b of the set of pads 3, 3 is worn.

FIG. 3 shows a wiring diagram of a pad lining replacement timing warning device in the four-wheel disc brake which enables the wear judgment of the left and right pad linings. The fixed contact S of the rotary switch 11 on the main body side is the four-wheel disc brake A. Eight ground wires independent of each left and right pad electrode 8 of ~ D
10a1, 10a2 to 10d1, 10d2 are 8 contacts that are evenly arranged in the rotor rotation direction, and the movable contact on the rotor side that is manually turned contacts the fixed contact S (8 contacts) on the main body at the same time. The contact R (8 contacts) has one second movable contact T (moving contact for detection) located in the middle of the main body side fixed contact S, which is added to 9 contacts, and the rotor conduction that energizes the 9 contacts on the rotor side The difference is that an alarm device 12 consisting of a warning lamp is connected by wire 14 between the terminal O and the battery 13 as shown in the drawing. Since other configurations and operations are substantially the same as those shown in FIG. 2, the same portions are denoted by the same reference numerals and detailed description thereof will be omitted.

[Effect of device]

Since the pad lining replacement timing warning device in the disc brake of the present invention has the above-mentioned structure, when the pad lining is worn to the limit of its use,
This pad lining replacement timing warning signal can be automatically issued to the driver, and the risk of abnormal wear of the pad lining can be eliminated in advance.

Further, according to the present invention, if a switch provided between each electrode and the alarm device is switched to connect the first movable contact to a plurality of electrodes at the same time, at least one of the electrodes is a rotating disk. The alarm device will be activated when the brake pads are touched, so that the alarm device can be activated even if any of the brake pads provided for each of the plurality of disc brakes reaches the limit of use. It is possible to accurately notify the driver of the existence.

If the switch is operated to connect the second movable contact to any one of the plurality of electrodes, the alarm is activated when the connected electrode comes into contact with the rotating disk. By sequentially switching the electrodes that connect to each other, it is possible to identify the brake pad that has worn out until the time of replacement. Therefore, it is possible to determine which brake pad should be replaced, and there is an advantage that maintainability can be improved.

Further, according to the present invention, since it is possible to identify the brake pad which has reached the replacement time without providing an alarm device for each of a plurality of disc brakes, it is not necessary to use a plurality of alarm devices and the configuration can be simplified. There are also advantages.

[Brief description of drawings]

FIG. 1 is a sectional view of a disc pad assembly equipped with a bad lining replacement timing warning device according to an embodiment of the present invention, and FIGS. 2 and 3 are bad lining replacement timing warnings for a four-wheel disc brake. FIG. 4 is a wiring diagram of the apparatus, FIG. 4 is a cross-sectional view for explaining the structure of a conventional automobile disk brake (opposed piston type), and FIG. 5 is a front view showing a pad structure of the disk brake. 3 ... Brake pad, 3a ... Back metal, 3b ... Lining, 4 ... Rotating disk, 5 ... Horizontal hole, 6 ... Vertical hole, 7 ... Horizontal electrode, 8 ... Vertical electrode, 7a, 8a ...... Insulator bush, 9 ...... Terminal screws, 10 (10a to 10d, 10a1, 10a2 to 1
0d1, 10d2) …… Ground wire, 11 …… Rotary switch, 12 …… Alarm, 13 …… Battery.

Claims (1)

[Scope of utility model registration request] 1. A brake pad having a pad lining which is provided for each of a plurality of disc brakes and crimped to a rotating disc, and when the pad lining is worn by being electrically connected to each of the brake pads and the pad lining is worn to its limit of use. An electrode provided so as to contact the rotating disk, an alarm device for issuing a warning signal such as a light or a sound to a driver, and an electrode provided between each electrode and the alarm device, and the electrodes are simultaneously provided. A first movable contact, which is connectable and hard-wired to activate the alarm when at least one of the electrodes contacts the rotating disk, and is connectable and connectable to any one of the plurality of electrodes. A switch configured to be switchable between a second movable contact hard-wired to activate the alarm when the electrode contacts the rotating disk. A disc brake pad lining replacement time warning device characterized in that