JP2874807B2 - Drum brake shoe lining polishing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for polishing a lining of a drum brake shoe.

[0002]

2. Description of the Related Art A drum brake shoe used in a drum brake device has a shoe assembly in which a lining is heated and pressurized and bonded to an outer surface of an arc-shaped shoe. Polishing is performed so as to obtain a predetermined braking force. Conventionally, when polishing the lining of the above-mentioned shoe assembly, the shoe assembly was assembled to a predetermined jig, rotated together with the jig, polished with a rotating grindstone, and adjusted to a predetermined outer diameter. The polishing apparatus has a table which can be moved and adjusted in X, Y and Z directions with respect to the rotating grindstone. The jig is mounted on the table, and a shoe assembly fixed by the jig is used. The position of the table is set so as to be a predetermined position and a predetermined cutting position with respect to the rotating grindstone, whereby the cutting amount of the lining is made constant, and the outer diameter of the lining is made constant.

[0003]

Since the lining is made by mixing a friction material such as a metal fiber into a resin material, the lining is relatively soft and the wear of the rotary grindstone is relatively small. However, there is also a problem that the grinding wheel is worn while the shoe assembly is polished in a large amount, and the outer diameter of the lining is changed. Conventionally, the outer diameter inspection of the shoe assembly has been performed in such a manner that after a predetermined number of polishing of the shoe assembly, a sampling inspection is performed for each predetermined lot, and the outer diameter dimension of the lining is confirmed with a dial gauge or the like. However, even if the sampling inspection is performed, it takes time and trouble, but once a defective product occurs, there is a possibility that the shoe assembly of the entire lot to which the defective product belongs becomes a defective product, and there is a problem that the workability and the yield are deteriorated.

Accordingly, the present invention has been made to solve the above problems, and an object of the present invention is to provide a method for polishing a lining of a drum brake shoe, which can improve workability and product yield. It is in.

[0005]

The present invention has the following arrangement to achieve the above object. That is, a shoe assembly in which a lining is adhered to a shoe is attached to a jig, the shoe assembly is rotated together with the jig, the lining is polished with a grindstone, and the outer diameter of the lining is adjusted to a predetermined diameter. In the lining polishing method, a sensor is attached to the jig and detects a lining outer surface position of a shoe assembly that rotates together with the jig.The sensor performs the polishing while constantly and directly detecting the position of the lining outer surface. The lining position information from the sensor is compared with a preset reference position, so that the lining outer surface position falls within the reference range.
It is preferable to use a sensor having a contact, such as a dial gauge, that contacts the outer surface of the lining, as the sensor. In this case, it is more preferable to arrange a plurality of contacts in the width direction of the lining and detect the inclination of the lining in the width direction.

[0006]

[Function] Since polishing is performed while the polishing condition of the lining is constantly checked by the sensor, it is not necessary to inspect each time with a dial gauge or the like for each lot as in the past, and workability is improved, and at the same time, excessive or insufficient polishing is performed. And other defective products can be prevented, and the yield can be improved.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows a polishing apparatus 10. 1
Reference numeral 1 denotes a rotating grindstone which is provided on the grindstone base 12 so as to rotate at a high speed in a direction indicated by an arrow A in a vertical plane. Reference numeral 13 denotes a table.
1 and is movable in the Y direction in the figure. The table 13 is arranged on a table 16 which can be moved in the X direction on the drawing by operating the handle 15, and the table 16 can be moved in the Z direction (vertical direction) on the drawing by operating the handle 17. Since the table 13 is disposed on the table 18, the table 13 can be moved and adjusted in each of the X, Y, and Z directions with respect to the rotary grindstone 11 by operating these handles.

At a position on the table 13 which is substantially opposite to the rotary grindstone 11, there is provided a turntable 19 which is rotated in a horizontal direction in the direction of arrow B by a rotary mechanism (not shown). As shown in FIG. 2, two shoe assemblies 22 each having a lining 21 adhered to an outer surface of an arc-shaped shoe 20 are detachably fixed on the turntable 19 with two clamping plates 23 facing each other. The turntable 19 and the fastening plate 23 constitute a jig 24. Reference numeral 25 denotes a sensor comprising a dial gauge, which is provided on the table 13, and whose contact is elastically in contact with the outer surface of the lining 21 of the shoe assembly 22 fixed by the jig 24. A current corresponding to the contact position of the contact with the outer surface of the lining 21 is input to a comparator provided in the operation panel 26, and is compared with a previously input reference value by the comparator. . When the lining 21 is polished by the rotary grindstone 11, the contact moves by the amount of the polishing, and the current value input to the comparator fluctuates according to the amount of the movement. The display lamp on the display panel 27 is turned on. The operation panel 26 has a rotating grindstone 11 and a rotating table 1
9 are provided. Reference numeral 28 denotes a hood that covers the side and upper surfaces of the rotary grindstone 11, and removes abrasive powder by suction.

To explain the polishing operation, an operator first fixes the shoe assembly 22 on the table 13 by using a jig 24. Next, the handles 14, 15, and 17 are operated to initialize the table 13 so that the table 13 is at a predetermined position with respect to the rotating grindstone 11. Next, the start switch is pressed, and the rotary grindstone 11 and the rotary table 19 are rotated to start polishing the lining. When the lining 21 is polished by a predetermined amount, the contact moves, and the display lamp on the operation panel 27 is turned on, the rotating grindstone 11 and the rotating table 19 are stopped, and the shoe assembly 22 is removed from the jig 24 and separately. The polishing condition of the lining is checked with a dial gauge or the like. If the outer diameter of the lining is a desired value, the initial setting is correct and the polishing operation of the next shoe assembly is continued as it is. In this continuous polishing, polishing is performed while the polishing state of the lining 21 is constantly checked, so that it is not necessary to inspect each time with a dial gauge or the like for each lot as in the past, so that workability is improved, and at the same time excessive polishing or insufficient polishing. Thus, the occurrence of defective products such as the above can be prevented, and the yield can be improved. If the initial settings are not correct, the position of the table 13, the position of the dial gauge 25, etc. may be reset.

In the above description, the indicator lamp is turned on when the polishing amount reaches a predetermined amount, and the operator stops the rotary grindstone 11, the turntable 19, etc., but when the polishing amount reaches the predetermined amount. , The rotating grindstone 11 and the rotating table 19 may be controlled to be stopped automatically, and a buzzer or the like may be used to notify the end of polishing. Further, it is preferable that the rotating grindstone 11 and the like be automatically stopped even in the case of excessive polishing. Further, if a display timer is not provided and the indicator lamp does not light after a lapse of a predetermined time after the start of polishing, the rotating grindstone 11 may be worn out. FIG. 3 shows an example in which three dial gauges are provided. In the present embodiment, the contacts of each dial gauge are made to contact at the upper portion, the central portion, and the lower portion in the width direction of the lining 21, and the polishing state of each portion is detected. When the polishing status of each part is the same and the respective indicator lamps are turned on almost at the same time, it is confirmed that normal polishing is being performed. When it is confirmed that there is a predetermined variation in the lighting state of each lamp, it is considered that the rotating grindstone 11 is partially reduced, and the wear state of the rotating grindstone is confirmed. Thereby, the inclination of the lining 21 in the width direction can be confirmed, and the polishing can be performed more accurately. In the above embodiment, a dial gauge having a contact is used as a sensor, but a non-contact laser sensor, an infrared sensor, or the like may be used.

Although the present invention has been described in detail with reference to preferred embodiments, the present invention is not limited to these embodiments, and many modifications can be made without departing from the spirit of the invention. Of course.

[0012]

As described above, according to the present invention, the drum
In the method of polishing a rake shoe lining, the shoe
Provide a sensor to detect the position of the lining outer surface of the assembly,
The position of the outer surface of the lining is always and directly
Polishing while detecting (Position detection of lining outer surface and
Lapping), and lining position information from the sensor
Compared with the reference position set in advance,
Position is set within the reference range.
Even if the outer dimensions of the lining can be accurately determined, for example,
Notifies the operator when the amount of polishing reaches the specified amount
And finish the polishing work.
Polishing can be easily prevented, not only improving workability,
Product defects are eliminated and the yield is improved.
I do.

[Brief description of the drawings]

FIG. 1 is a perspective view of a polishing apparatus.

FIG. 2 is a front view of the shoe assembly.

FIG. 3 is an explanatory view of an embodiment in which three dial gauges are provided.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Polishing apparatus 11 Rotary grindstone 13 Table 23 Jig 25 Sensor 26 Operation panel

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Claims (3)

(57) [Claims] 1. A drum for assembling a shoe assembly with a lining bonded to a shoe to a jig, rotating the shoe assembly together with the jig, polishing the lining with a grindstone, and adjusting the outer diameter of the lining to a predetermined diameter. In the method for polishing a lining of a brake shoe, a sensor is provided for detecting a position of an outer surface of a lining of a shoe assembly which is mounted on the jig and rotates together with the jig , and the position of the outer surface of the lining is constantly and directly detected by the sensor. A method for polishing a lining of a drum brake shoe, wherein the polishing is performed, and lining position information from a sensor is compared with a preset reference position so that the lining outer surface position falls within a reference range. 2. The method for polishing a lining of a drum brake shoe according to claim 1, wherein a sensor having a contact, such as a dial gauge, that contacts an outer surface of the lining is used as the sensor. 3. The method for polishing a lining of a drum brake shoe according to claim 2, wherein a plurality of contacts are arranged in the width direction of the lining, and a degree of inclination of the lining in the width direction is detected.