JPH05162669A - Locating pin wear detecting device - Google Patents

Abstract

PURPOSE:To attain the efficiency of maintenance work by detecting the wear of a locating pin on the basis of a current flowing between a workpiece and the locating pin due to the contact between the workpiece and locating pin. CONSTITUTION:Normally, the insulated state is kept electrically as long as the insulation of a part 9 is kept even if a panel 14 and a locating pin 1 are brought into mutual contact, so that a wear detecting device 3 does not receive a signal to the effect that the locating pin 1 is worn. However, when the insulated layer of the part 9 is worn by the repeated contact between the panel 14 and locating pin 1 to place the panel 14 into such a state as to come in direct contact with the current flowing part 11 of the locating pin 1, a leak current from a welding gun 15 flows into the wear detecting device 3 through the current flowing part 11. The wear detecting device 3 recognizes which locating pin this current flows in from and displays this information on a monitor 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a locate pin wear detecting device for detecting wear of a locate pin used for fixing a body of a vehicle, for example.

[0002]

2. Description of the Related Art For example, in a vehicle production process, a vehicle conveyed to each stage is fixed, and various works are applied to the fixed vehicle. This fixing is performed by locating pins.
Since fixing and positioning by the locate pin is generally performed, detailed description thereof will be omitted, but the outline is as follows. In other words, the vehicle is transported to the approximate position by the transportation device, and the fixing device provided with the locate pin operates to securely fix and position the transported vehicle. By this operation, the hole for engaging the locate pin provided on the vehicle and the locate pin are engaged with each other, and the vehicle is securely fixed at the desired position.
In this state, for example, welding work is performed. After the work is completed, the fixing device is activated to release the engagement, and the vehicle is moved to the next step by the transfer device.

[0003]

Although the locate pin used for such a purpose is made of metal, the locate pin provided on the vehicle side is engaged with the locate pin by the operation of the fixing device. In some cases, the two may come into contact with each other, so that the locating pin gradually wears as it is used. When the degree of this wear increases,
Since this will cause a problem in the positioning accuracy of the vehicle, it is necessary to always know the degree of wear. The degree of this wear needs to be measured by the operator using a micrometer or calipers, and the replacement time is also predicted based on the measurement result. Since this measurement work requires a lot of manpower and time, it has been a burden of maintenance work. Further, when a problem occurs in the positioning accuracy of the vehicle, it is not possible to easily determine which locating pin is worn due to wear. Therefore, the locating pin causing the locating pin was found by trial and error and replaced. .. For this,
It took a long time to recover. The present invention has been made to solve the above conventional problems, and an object of the present invention is to provide a locate pin wear detection device capable of automatically detecting wear of a locate pin.

[0004]

According to the present invention for achieving the above object, at least a portion which can come into contact with a workpiece and a portion which comes into contact with a mounting member are insulated and are made of a conductive material. When the locate pin and the portion of the locate pin that comes into contact with the workpiece due to use are worn and the insulation of the portion is destroyed, the workpiece and the locate pin are contacted by the contact between the workpiece and the locate pin. Wear detecting means for detecting wear of the locate pin based on a current flowing between the two.

[0005]

In the locating pin, at least the portion that can come into contact with the workpiece and the portion that can come into contact with the mounting member are insulated, so that the locating pin does not come into electrical contact with the workpiece in a normal state. When the contact portion of the locate pin is worn due to use, the locate pin and the workpiece are brought into electrical contact with each other, and the wear detection means detects this and notifies the replacement of the locate pin.

[0006]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram of a locate pin wear detection device according to the present invention, and FIG. 2 is a detailed configuration diagram of the locate pin shown in FIG. As shown in FIG. 1, locating pins 1 for positioning and fixing the vehicle body B at a predetermined position are mounted on mounting bases 2, respectively. A hole (not shown) for receiving the locate pin 1 is opened on the vehicle body B side. When the vehicle body 1 is loaded, the locating pin 1 is retracted, but when the loading of the vehicle body 1 is completed, the locating pin 1 is projected and protrudes.
The vehicle body B is positioned in a predetermined position by being inserted into the hole opened to the side. Each of the locate pins 1 is connected to the wear detecting device 3. The wear detection device 3 detects the electrical connection state between the vehicle body B and the locate pin 1 when the locate pin 1 is worn. A monitor 4 is connected to the wear detecting device 3. When the wear detecting device 3 detects wear of any locate pin, the monitor 4 determines which locate pin is worn. It is supposed to be displayed.

The specific structure of the locate pin 1 shown in FIG. 1 is as shown in FIG. The locate pin 1 is attached to the attachment base 2. This mounting is performed by the flange 6 integrally formed on the locate pin 1 and the nut 7 screwed to the screw formed on the locate pin 1. In this mounting, the locate pin 1 and the mounting base 2 are electrically insulated from each other. Therefore, the both are insulated by using an insulator 8 such as a washer formed of an insulating material such as bakelite. Further, an insulating treatment is applied to the portion 9 that may come into contact with the periphery of the hole that engages with the locate pin 1 provided on the vehicle side. In the present embodiment, this insulation treatment is performed only on the portions that may come into contact, but of course the insulation treatment may be performed on the entire outer peripheral surface of the locate pin 1. Since the abrasion resistance of the portion subjected to this insulation treatment must be relatively high, the insulating material should be used in consideration of this point. Ceramic coating is applied to the tip portion 10 of the locate pin 1, that is, the portion that enters the hole on the vehicle side. Locate pin 1
Is mainly composed of metal, and that portion functions as the current-carrying portion 11. A connector portion 13 to which a connector 12 connected to the wear detecting device 3 is attached is formed at the other end of the locate pin 1, and the connector 12 and the connector portion 13 are electrically connected. It should be noted that the panel 14 of the vehicle body, which is the workpiece to be illustrated, is used.
Are welded by the welding gun 15.

The locate pin wear detecting device of the present invention thus constructed operates as follows. First,
In the normal state as shown in the figure, even if the panel 14 and the locate pin 1 come into contact with each other, as long as the insulation of the part shown in FIG. Does not input the signal that the locate pin 1 has worn. However, if the panel 14 and the locate pin 1 are repeatedly brought into contact with each other and the insulating layer in the portion shown in FIG. It will flow into the wear detection device 3 via this energization portion 11. The wear detection device 3 recognizes from which locating pin this current has flown,
The information is displayed on the monitor 4. The cause of wear of the locate pin 1 is considered to be when the locate pin 1 engages with the hole on the vehicle body side or due to vibration of the vehicle body during processing. In the welding process, wear due to vibration during welding is particularly severe.

Since the welding process is exemplified in the above embodiment, the wear of the locate pin 1 can be recognized based on the leak current from the welding gun, but in the case of other processes, the locate pin wear detection for the vehicle body B is performed. It is necessary to apply the voltage from the power source of. If the locate pin wear detection device as in the present embodiment is connected to all locate pins of the whole factory, it is possible to centrally perform maintenance management of the locate pin of the whole factory without performing wear measurement of the locate pin or estimation thereof. You can do it.

[0010]

As described above, according to the present invention, the wear of the locate pin is automatically detected.
The efficiency of maintenance work related to this wear can be improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a locate pin wear detection device according to the present invention.

FIG. 2 is a detailed structural diagram of a locate pin that constitutes the device shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Locating pin 2 ... Mounting base 3 ... Wear detecting device (wear detecting means) 4 ... Monitor 6 ... Flange 7 ... Nut 8 ... Insulator 11 ... Conducting part 12 ... Connector 13 ... Connector part 14 ... Panel

Claims (1)

[Claims] 1. A locate pin made of a conductive material, wherein at least a portion capable of contacting a workpiece and a portion capable of contacting a mounting member are insulated, and a portion of the locate pin contacting a workpiece when used. If the insulation of the portion is broken due to wear, the wear of the locate pin is detected based on the current flowing between the work and the locate pin due to the contact between the work and the locate pin. A locate pin wear detecting device comprising: wear detecting means.