JPH0726074U - Chip removal electrode management device - Google Patents

Abstract

(57) [Summary] [Purpose] When the electrode tip of the spot welding machine comes off,
Prevent leakage of cooling water and electric contact. [Structure] Electrode tip 4 on shank 3 of spot welder
In the electrode device 8 fitted with, the cooling water passage pressure changes when the electrode tip is pulled out from the shank and the IN side of the internal cooling water circuit inside the electrode, and the cooling water passage is closed. Means 10 were provided. The tip surface of the shank other than the tip fitting portion 5 was coated with a plastic insulating material 7. By doing this, the change of the cooling water pressure when the electrode tip falls off is used to immediately stop the running of the cooling water on the IN side, and the shank tip surface is coated with an insulating layer. In addition to preventing the electric contact, the cooling water channel is not narrowed, water stains are reduced and the cooling effect is enhanced, and the insulating material and assembly man-hours of separate parts are unnecessary.
The manufacturing cost is also low.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an electrode management device for preventing leakage of cooling water and preventing electrical contact when an electrode tip of a stationary spot welding machine, spot welding gun, etc. comes off.

[0002]

[Prior art]

 Conventionally, in a spot welder, there is a known method of preventing energization under pressure when the electrode tip comes off. For example, in Japanese Patent Laid-Open No. 57-62878, "Spot Welding Electrode Tip Separation Detection and False Current-Prevention Method," the insulating means provided at the tip of the shank when the electrode tip fitted to the shank comes off is This is done by interlocking and stopping the energization of the control circuit with an electric signal when the contact detection circuit detects insulation.

On the other hand, in the case of preventing electrode damage due to erroneous pressurization / energization when the electrode tip comes off, for example, JP-A-60-108489, JP-A-60-126288, and JP-A-60-126288. Japanese Unexamined Patent Publication No. 61-41484 has been proposed. The purpose of all of these is to protect the electrode from electrical contact by covering the tip surface of the shank to which the electrode tip is fitted with an insulator.

In the conventional device, when the dropout of the electrode tip is electrically detected, a flow switch provided on the OUT side of the internal cooling water circuit of the electrode is activated, and a signal from the switch is provided on the IN side. The solenoid valve was closed to stop the cooling water.

In addition, in the conventional one that insulates the tip end surface of the shank, the number of parts is increased because an insulating bush and another insulating plate are inserted, and moreover, the number of assembling steps is also increased, resulting in cost increase. Invite. In addition, by inserting insulating parts, the cooling water channel can be narrowed and water stains can easily accumulate there, limiting the flow rate of cooling water and reducing the cooling operation. Not practical.

[0006]

[Problems to be solved by the device]

 The problem with the present invention is that the conventional large-scale management system that electrically detects electrode tip omissions inevitably raises costs including wiring and piping man-hours, and is restricted in space due to the large-scale structure. Is the solution.

[0007]

[Means for Solving the Problems]

 The present invention was devised to achieve the above object, and in an electrode in which an electrode tip is fitted to the shank of a spot welding machine, the electrode from the shank is connected to the IN side of the internal cooling water circuit of the electrode. It is characterized in that means for operating in the direction of closing the cooling water passage on the IN side is provided by a change in cooling water pressure that occurs when the tip comes off.

Further, the tip surface of the shank other than the electrode tip fitting portion is coated with a plastic insulating material.

[0009]

[Work]

 Therefore, in the present invention, the first stop valve is provided on the IN side of the internal cooling water circuit to the electrode, and the pilot check valve is provided on the outlet side of the valve, and the outlet side of the first stop valve and the pilot valve are connected. Since a second stop valve is provided between the outlet side and the pilot valve on the OUT side, back pressure is released when the electrode tip comes off from the shank. In other words, when the pilot pressure decreases due to the drainage, the pilot check valve works and stops the cooling water supply on the IN side. Therefore, a simple management system is realized by utilizing the change in drainage pressure without using electric signals as in the past.

[0010]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of an electrode including a cooling circuit of an electrode management device of the present invention. FIG. 2 is a sectional view of the electrode device showing a state where the electrode chip has fallen out.

In the figure, 1 is an electrode management device. Reference numeral 2 is a conductive member such as an electrode holder or a gun arm. 3 is a shank. An electrode tip 4 is fitted in a tip fitting portion 5 provided at the tip of the shank 3. Reference numeral 6 is a water cooling pipe, which is internally provided on the axis of the conductive member 2, the shank 3, and the electrode chip 4, and constitutes an IN / OUT side water circulation path as indicated by arrows.

Reference numeral 7 is a plastic insulating layer in which the tip end surface of the shank is insulatingly coated. This insulating layer is for insulating and protecting the tip of the shank by preventing electric contact or damage due to incorrect pressurization when the electrode tip 4 comes off. With this insulation attachment method, the coating can be applied by masking only the shank tip fitting part and then immersing only the tip surface of the fitting part in the plastic solution for a few seconds. As with other insulation boards, the number of parts is not needed, and the assembly man-hours are not required.

Reference numeral 8 indicates an electrode device. Reference numeral 9 is a first stop valve provided on the IN side of the internal cooling water circuit of the electrode. Reference numeral 10 is a pilot check valve provided on the outlet side of the first stop valve. Reference numeral 11 is a second stop valve connected between the outlet side of the first stop valve and the outlet side of the pilot check valve 10. Reference numeral 12 indicates a pilot check valve provided on the OU T side.

In the above-mentioned configuration, when the electrode tip 4 is removed in the state of FIG. 2 and the shank 3 pressurizes and energizes the object to be welded at the next welding point position, the shank contacts the object to be welded at the next welding point position. They come into contact and no current flows. Moreover, at the moment when the electrode tip comes off, the pilot pressure (drainage pressure) decreases, the pilot check valve 10 operates, and the cooling water on the IN side is closed.

In this embodiment, the pilot check valve 10 is used on the IN side of the cooling water circuit, but the present invention is not limited to this, and the same effect can be obtained by using various means such as a pilot type switching valve. To be

[0016]

[Effect of device]

 As described above, according to the present invention, when the electrode tip falls out, a simple management system that can stop the cooling water supply on the IN side by utilizing the change of drainage pressure without using an electric signal as in the past To realize. Therefore, compared with the conventional large-scale management system that electrically detects electrode tip omissions, the wiring and piping man-hours can be reduced and the design space constraints can be eliminated, realizing a novel electrode management device. You can

On the other hand, in the present invention, since the tip surface of the shank is coated with a high-strength insulating film, unlike the conventional structure in which a thick insulating bush or insulating plate is fitted, only the tip surface of the shank is thin. Since the insulating layer is attached by coating, the cross-sectional area of the cooling water channel is not narrowed, and by eliminating the adhesion of water stains, the cooling water flow rate can be reduced and the cooling effect can be dramatically improved. Realize a practical device. It also contributes to cost reduction by reducing the number of parts and assembly man-hours.

[Brief description of drawings]

FIG. 1 is a cooling water system diagram including a partially crushed cross section showing a structural example of a tip missing electrode management device according to the present invention.

FIG. 2 is a sectional view of an electrode in a state where an electrode tip has fallen out.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrode management device 2 Conductive member 3 Shank 4 Electrode tip 5 Tip fitting part 6 Water cooling pipe 7 Insulating material 8 Electrode device 9 First stop valve 10 Pilot check valve 11 Second stop valve 12 Pilot check valve

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[Procedure amendment]

[Submission date] December 2, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

Claims (2)

[Scope of utility model registration request] 1. In an electrode having an electrode tip fitted to a shank of a spot welding machine, a change in cooling water pressure generated when the tip comes out of the shank is applied to the IN side of an internal cooling water circuit inside the electrode. A tip missing electrode management device comprising means for operating in the direction of closing the cooling water passage. 2. An electrode management, wherein an electrode having an electrode tip fitted to a shank of a spot welding machine is coated with a plastic insulating material on the tip surface of the shank other than the tip fitting portion. apparatus.