JP2017047469A - Electrode for electric resistance welding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent fine impurities such as a spatter from reaching a surface adhesion part which interrupts and continues a circulation of cooling air.SOLUTION: A slide part 15 is fitted into a guide hole 6 of an electrode body 1. The slide part 15 is constituted of a main slide part 21 and a sub slide part 22 advancing and retreating inside a sub guide hole 8. An end face 31 of the main slide part 21 and an inner end face 32 of a main guide hole 7 are brought into close contact with or separated from each other to interrupt and continue cooling air from an air passage 29 provided in the main slide part 21. An exhaust passage 36 extending from a boundary part 23 between the sub guide hole 8 and a pin hole 9 of a guide pin 14 in a diameter direction of the electrode body 1 and opening on an outer peripheral surface of the electrode body 1 is formed.SELECTED DRAWING: Figure 1

Description

  This invention is an electric resistance welding in which a sliding portion made of a synthetic resin in which a guide pin made of a metal material or the like is integrated is inserted into a guide hole of an electrode body, and an exhaust passage is formed in the electrode body It relates to an electrode.

  In Japanese Patent No. 2903149 and Japanese Patent No. 4203672, an opening / closing valve structure portion is formed in which the end surface of the sliding portion and the inner end surface of the guide hole come into close contact with each other and disconnect the cooling air. It is described that an exhaust passage in the diameter direction is formed, and cooling air supplied into the electrode body discharges impurities such as cooling of the electrode and sputtering.

Japanese Patent No. 2903149 Japanese Patent No. 4203672

  In the technique described in the above-mentioned patent document, impurities such as spatter are discharged and the electrodes are cooled by a jet of cooling air, but the end face of the sliding portion and the inner end face of the guide hole are in close contact with or separated from each other. Therefore, there is a possibility that fine impurities may reach the structure part that interrupts the cooling air, that is, the surface contact part.

  The present invention is provided in order to solve the above-described problems, and a fine impurity is obtained by combining a member for preventing movement of fine impurities such as sputtering and an arrangement state of an exhaust passage for discharging impurities. The purpose is to prevent the surface from reaching the surface contact portion.

The invention described in claim 1
A guide pin with a circular cross section that protrudes from the end face of the electrode body with a circular cross section and penetrates the pilot hole of the steel plate part is composed of a heat-resistant hard material such as a metal material or a ceramic material,
It is fitted in a slidable state in the guide hole of the electrode body, and the sliding portion having a circular cross section integrated with the guide pin is made of a synthetic resin material.
The sliding part advances and retreats in a sliding state in a main sliding part that advances and retreats in the main guide hole and a sub guide hole whose diameter is smaller than that of the main sliding part and smaller than that of the main guide hole. And a sub-sliding portion that reduces the inclination angle of the guide pin,
A pin hole is formed which is smaller in diameter than the sub guide hole and is inserted in a state where the guide pin is slidable or provided with a ventilation gap,
The end surface of the main sliding portion and the inner end surface of the main guide hole are in close contact with each other, and the cooling air is intermittently connected from the air passage provided in the main sliding portion,
An electrode for electric resistance welding, characterized in that an exhaust passage extending from the boundary portion between the sub guide hole and the pin hole in the diameter direction of the electrode body and opening on the outer peripheral surface of the electrode body is formed.

  When the part supported by the guide pin is pushed down by the movable electrode, the guide pin moves to the place where the part is pressed against the steel plate part, and the end surface of the main sliding part moves from the inner end surface of the main guide hole accordingly. Leave. By this separation operation, the cooling air from the air passage provided in the main sliding portion extends in the diameter direction of the electrode body from the gap between the sub sliding portion and the sub guide hole and the boundary between the sub guide hole and the pin hole. Then, the gas flows sequentially into the exhaust passage that opens to the outer peripheral surface of the electrode body, the gap between the guide pin and the pin hole, the gap between the guide pin and the lower hole of the steel plate part, and the gap between the part and the steel plate part.

  The electrode body is cooled by such an air flow. On the other hand, fine impurities such as spatter generated when the welding protrusions and the steel plate parts are melted go against the air flow, and the gap between the guide pins and the lower holes of the steel plate parts, and between the guide pins and the pin holes. It tends to enter between the end surface of the main sliding portion and the inner end surface of the main guide hole through a gap, a sliding gap between the sub sliding portion and the sub guide hole.

  However, the exhaust passage extends in the diameter direction of the electrode body from the boundary between the sub guide hole and the pin hole and opens to the outer peripheral surface of the electrode body, and the sub guide hole extends to the space portion of the exhaust passage. The sub sliding portion is inserted into the sub guide hole. With such an arrangement, the end surface of the sub-sliding portion exists in the vicinity of the exhaust passage or at a position where it enters the exhaust passage in a state where the end surface of the main sliding portion is separated from the inner end surface of the main guide hole.

  In such a state, the fine impurities scattered vigorously in the gap between the guide pin and the pin hole against the air flow collide with the end surface of the sub-sliding portion and bounce off. The rebounded impurities are discharged to the outside through the exhaust passage by the air flow from the sliding gap between the sub sliding portion and the sub guide hole toward the exhaust passage. By such discharge, impurities do not reach between the end surface of the main sliding portion and the inner end surface of the main guide hole, and the intermittent operation of the cooling air is normally performed.

  In the impurity discharging operation described above, since the end surface of the sub-sliding portion is waiting near the boundary between the sub-guide hole and the pin hole, it is essential that the impurities collide with this end surface. ing. And since an impurity hits the end surface of a sub-sliding part and bounces back, it becomes easy to get on the said air flow, and this is actively discharged | emitted from the exhaust passage outside.

  The invention of the present application is an invention of the electrode structure as described above, but as can be seen from the examples described below, it can exist as a method invention specifying the behavior / migration process of impurities.

It is sectional drawing of each part of an electrode. It is sectional drawing of another electrode.

  Next, a mode for carrying out the electrode for electric resistance welding of the present invention will be described.

  1 and 2 show an embodiment of the present invention.

  First, the guide hole of the electrode body will be described.

  The electrode body 1 made of copper alloy has a cylindrical shape, and a fixing portion 2 to be inserted into the stationary member 11 and a cap portion 4 on which the steel plate component 3 is placed are coupled at a screw portion 5. A guide hole 6 having a circular cross section is formed in the electrode body 1, and this guide hole 6 is mainly the main guide hole 7 having the largest diameter formed in the fixing portion 2, and the cap portion 4 having a smaller diameter than the main guide hole 7. The sub guide hole 8 formed in the above and the pin hole 9 having a smaller diameter than the sub guide hole 8 are arranged in a coaxial state aligned on the central axis OO of the electrode body 1.

  A tapered portion 10 is formed below the fixed portion 2, and the tapered portion 10 is inserted into a tapered hole provided in the stationary member 11. A vent 12 for introducing compressed air into the guide hole 6 is provided on the side of the fixed portion 2.

  Next, the sliding part will be described.

  The guide pin 14 is made of a heat-resistant hard material such as a metal material such as stainless steel or a ceramic material. The sliding portion 15 is made of an insulating synthetic resin excellent in heat resistance, for example, polytetrafluoroethylene (trade name: Teflon). The guide pin 14 is integrated in a state of being inserted into the sliding portion 15. Both the guide pin 14 and the sliding portion 15 have a circular cross section, and the guide pin 14 penetrates the lower hole 16 of the steel plate part 3 relatively to perform the positioning function of the steel plate part 3 and is fitted to the tip part thereof. An iron projection nut 17 is supported. For this purpose, a small-diameter portion 18 that matches the screw hole of the projection nut 17 is formed. Until the movable electrode 20 is lowered, a gap C is formed between the welding projection 19 and the steel plate part 3.

  In the following description, the projection nut may be simply expressed as a nut. The nut 17 is formed with a screw hole at the center of a square main body, and welding projections 19 are formed at the four corners of the main body. The electrode body 1 is a fixed electrode, and a movable electrode 20 is arranged coaxially therewith.

  In addition, the BB cross section of FIG. 1 (A) is the (B) figure of the same figure.

  The sliding portion 15 includes a main sliding portion 21 that slides in the main guide hole 7 and a sub sliding portion 22 that slides in the sub guide hole 8. The main sliding portion 21 and the sub sliding portion Reference numeral 22 denotes a coaxial arrangement arranged on the central axis OO of the electrode body 1. The sub-sliding portion 22 has a length dimension extending substantially over the entire length of the sub-guide hole 8.

  The main sliding portion 21 and the sub sliding portion 22 are fitted in the holes 7 and 8 so as to slide on the inner surfaces of the main guide hole 7 and the sub guide hole 8, respectively. The amount of movement of each sliding portion in the diameter direction is extremely small, and the cooling air described later can be circulated. In other words, there is no shakiness in the diametrical direction and it can smoothly advance and retreat, and air circulation is allowed. The sliding gaps between the main sliding portion 21 and the sub-sliding portion 22 are indicated by reference numerals 25 and 26, respectively. Also. A gap between the guide pin 14 and the pin hole 9 is indicated by reference numeral 27. Further, the gap between the guide pin 14 and the lower hole 16 is indicated by reference numeral 28.

  If the sliding part 15 moves in the diameter direction or the inclination direction under the sliding gap 25 as described above, the guide pin 14 is excessively swung, so that the secondary sliding part 22 hits the inner surface of the secondary guide hole 8. The inclination angle of the guide pin 14 is reduced to minimize the misalignment of the guide pin 14.

  Although the sliding gap 25 exists as described above, an air passage 29 is formed as shown in FIG. 1 (B) in order to actively pass the cooling air supplied from the vent 12. Has been. Such an air passage can be constituted by a ventilation groove formed in the direction of the central axis OO, but here is constituted by a flat portion 30 formed in the main sliding portion 21.

  Next, the surface contact portion will be described.

  The main sliding portion 21 and the sub-sliding portion 22 have a stepped structure as illustrated, and an end face 31 is formed on the main sliding portion 21. This end face 31 exists on a virtual plane that intersects perpendicularly to the central axis OO. Further, the inner end face 32 of the main guide hole 7 also exists on a virtual plane that intersects the central axis OO perpendicularly. A portion where the end face 31 is in close contact with the inner end face 32 is a “surface close contact portion”, and the close contact portion has an annular shape, and at the time of close contact, the valve closing function is performed to block the flow of cooling air. At the time of separation, it fulfills the valve opening function and circulates cooling air.

  The close contact of the surface contact portion is ensured by the tension of the compression coil spring 34 disposed in the guide hole 6.

  Next, the exhaust passage will be described.

  Since there is a difference in diameter between the auxiliary guide hole 8 and the pin hole 9, a boundary portion 23 exists at a continuous portion of the holes 8 and 9. The boundary portion 23 is a flat annular surface located on a virtual plane perpendicular to the central axis OO due to a difference in diameter between the sub guide hole 8 and the pin hole 9. The length of the sub-sliding portion 22 is set so that the end surface 24 contacts the boundary portion 23 or is positioned just before the boundary portion 23. The case shown in FIG. 1C is a case where the end face 24 is positioned just before the boundary portion 23.

  The exhaust passage 36 is a through-hole having a circular cross section provided in the diameter direction of the electrode body 1, and the electrode central side of the exhaust passage 36 communicates with the pin hole 9 and the sub guide hole 8 at the boundary portion 23, Is open on the outer surface of the cap portion 4. That is, the exhaust passage 36 extends from the boundary portion 23 between the sub guide hole 8 and the pin hole 9 in the diameter direction of the electrode body 1 and opens to the outer peripheral surface of the electrode body 1. One exhaust passage 36 shown in FIG. 1 is formed in the left-right direction in FIG. 1, but another exhaust passage 36 may be provided in a state orthogonal to the exhaust passage 36. By doing so, the exhaust passage 36 extends in four directions when viewed in plan.

  FIG. 1E shows the positional relationship between the circular cross-sectional shape of the exhaust passage 36 and the end face 24 of the auxiliary sliding portion 22. The position L1 is a state in which the surface contact portion is closed, and the end surface 24 is located at a location crossing the circular shape of the exhaust passage 36 as shown in FIG. The position L2 is a state in which the surface contact portion is open, and the end surface 24 is positioned slightly below the circular shape of the exhaust passage 36 as shown in FIG.

  Next, other structures will be described.

  A bolt 37 is formed integrally with the end of the guide pin 14, passes through the bottom member 38 of the sliding portion 15, a washer 39 is assembled, and is tightened with a lock nut 40. The sliding portion 15 has an insulating function so that when the movable electrode 20 is operated and a welding current is applied, the current flows only from the welding protrusion 19 of the nut 17 to the steel plate part 3.

  The aforementioned compression coil spring 34 is fitted between the washer 39 and the inner bottom surface of the guide hole 6, and the tension acts on the sliding portion 15 so that the end surface 31 is in close contact with the inner end surface 32. Reference numeral 35 denotes an insulating sheet fitted into the inner bottom surface of the guide hole 6.

  Next, the operation of the electrode will be described.

  FIGS. 1A and 1C show that the end surface 31 of the main sliding portion 21 is brought into close contact with the inner end surface 32 of the main guide hole 7 due to the tension of the compression coil spring 34, and cooling air is vented from the vent 12. Is stopped, and at this time, a gap C is left between the welding projection 19 and the steel plate part 3. At the same time, the end surface 24 of the sub-sliding portion 22 stops at a position L1 that enters the space of the exhaust passage 36, as shown in FIGS.

  Here, when the movable electrode 20 advances and the guide pin 14 is pushed down, the surface contact portion opens, and the cooling air flows into the air passage 29, the open surface contact portion, the sliding gap 26, the exhaust passage 36, the gap 27, Flowing to the gap 28, the cap part 4, the guide pin 14, the sliding part 15 and the like are cooled. When such an air flow is formed, the end surface 24 of the sub-sliding portion 22 is at a position L2 shown in FIGS. 1D and 1E.

  Fine spatter scattered at the time of welding of the welding protrusions 19 tries to enter the sliding gap 26 through the gap 28 and the gap 27 in the reverse direction of the air flow, but most of them are waiting at the position L2. It collides with the end face 24 and is bounced back, and is discharged outside through the air flow from the sliding gap 26 toward the exhaust passage 36. Therefore, the minute impurities directed to the surface contact portion become extremely small amount and do not substantially cause a problem, and even if the slight impurity reaches the surface contact portion, it is pushed back by the air flow, It is possible to prevent harmful effects such as being caught.

  Next, a modified example of the guide pin will be described.

  As shown in FIG. 2, the parts to be welded here are projection bolts 42, a circular flange 44 is integrated with a shaft portion 43 with a male screw cut, and three welding protrusions are formed on the lower surface of the flange 44. 45 is formed on one circumference at intervals of 120 degrees.

  The guide pin 14 is provided with a receiving hole 46 for receiving the shaft portion 43. By such a receiving hole 46, the guide pin 14 has a hollow pin structure. The other configuration is the same as that of the previous example including a portion not shown, and the same reference numerals are described for members having similar functions.

  When the movable electrode 20 is brought into close contact with the flange 44 and the guide pin 14 is pushed down, the surface contact portion opens and cooling air flows, and in the same manner as the above-described operation, impurity intervention in the surface contact portion is avoided. .

  The operational effects of the embodiment described above are as follows.

  When parts such as the nut 17 and the projection bolt 42 supported by the guide pin 14 are pushed down by the movable electrode 20, the guide pin 14 moves to a place where the parts 17 and 42 are pressed against the steel plate part 3, and accordingly. Thus, the end surface 31 of the main sliding portion 21 is separated from the inner end surface 32 of the main guide hole 7. By this separation operation, the cooling air from the air passage 29 provided in the main sliding portion 21 is allowed to flow into the sliding gap 26 between the sub sliding portion 22 and the sub guide hole 8 and the boundary between the sub guide hole 8 and the pin hole 9. An exhaust passage 36 extending from the portion 23 in the diameter direction of the electrode body 1 and opening to the outer peripheral surface of the electrode body 1, a gap 27 between the guide pin 14 and the pin hole 9, a guide pin 14 and a pilot hole 16 of the steel plate part 3. Between the gap 28 and the parts 17 and 42 and the steel plate part 3, the air flows in sequence.

  The electrode body 1 is cooled by such an air flow. On the other hand, fine impurities such as spatter generated when the welding projections 19 and 45 and the steel plate part 3 are melted go against the air flow, and the gap between the guide pin 14 and the lower hole 16 of the steel plate part 3. 28, through the gap 27 between the guide pin 14 and the pin hole 9, the sliding gap 26 between the sub-sliding portion 22 and the sub-guide hole 8, and the like, the end surface 31 of the main sliding portion 21 and the main guide hole 7 An attempt is made to enter between the inner end faces 32.

  However, the exhaust passage 36 extends in the diameter direction of the electrode body 1 from the boundary portion 23 between the sub guide hole 8 and the pin hole 9 and opens to the outer peripheral surface of the electrode body 1. The auxiliary sliding portion 22 is inserted into the auxiliary guide hole 8 while reaching the space portion. With such an arrangement, when the end surface 31 of the main sliding portion 21 is separated from the inner end surface 32 of the main guide hole 7, the end surface 24 of the auxiliary sliding portion 22 enters the vicinity of the exhaust passage 36 or the exhaust passage 36. Exists in the position.

  In such a state, fine impurities that have scattered vigorously in the gap 27 between the guide pin 14 and the pin hole 9 against the air flow collide with the end surface 24 of the sub-sliding portion 22 and bounce off. It is. The repelled impurities are discharged to the outside through the exhaust passage 36 by the air flow from the sliding gap 26 between the sub sliding portion 22 and the sub guide hole 8 toward the exhaust passage 36. By such discharge, impurities do not reach between the end surface 31 of the main sliding portion 21 and the inner end surface 32 of the main guide hole 7, and the intermittent operation of the cooling air is normally performed.

  In the above-described impurity discharging operation, the end surface 24 of the sub-sliding portion 22 is waiting near the boundary portion 23 between the sub-guide hole 8 and the pin hole 9, so that the impurity reliably collides with the end surface 24. Is indispensable. The impurities hit the end surface 24 of the sub-sliding portion 22 and are bounced back, so that it is easy to get on the air flow, and thus the air is actively discharged from the exhaust passage 36 to the outside.

  Further, the sub-sliding portion 22 is provided with a function of preventing the guide pin 14 from excessively swinging and a function of repelling impurities that have reverted to the air flow at the end face 24. Therefore, since the sub-sliding portion 22 that is a single member performs a multi-functional role, it is effective in terms of simplification of the structure.

  As described above, according to the electrode of the present invention, by combining the arrangement state of the member for preventing the movement of fine impurities such as sputtering and the exhaust passage for discharging the impurities, the fine impurities are brought into the surface contact portion. Reaching can be prevented. Therefore, it can be used in a wide range of industrial fields such as automobile body welding processes and home appliance sheet metal welding processes.

DESCRIPTION OF SYMBOLS 1 Electrode main body 3 Steel plate component 6 Guide hole 7 Main guide hole 8 Sub guide hole 9 Pin hole 14 Guide pin 15 Sliding part 16 Lower hole 17 Projection nut, part 21 Main sliding part 22 Sub sliding part 23 Boundary part 24 End face 25 Sliding gap 26 Sliding gap 27 Gap 28 Gap 29 Air passage 31 End face 32 Inner end face 36 Exhaust passage 42 Projection bolt, parts

Claims (1)

A guide pin with a circular cross section that protrudes from the end face of the electrode body with a circular cross section and penetrates the pilot hole of the steel plate part is composed of a heat-resistant hard material such as a metal material or a ceramic material,
It is fitted in a slidable state in the guide hole of the electrode body, and the sliding portion having a circular cross section integrated with the guide pin is made of a synthetic resin material.
The sliding part advances and retreats in a sliding state in a main sliding part that advances and retreats in the main guide hole and a sub guide hole whose diameter is smaller than that of the main sliding part and smaller than that of the main guide hole. And a sub-sliding portion that reduces the inclination angle of the guide pin,
A pin hole is formed which is smaller in diameter than the sub guide hole and is inserted in a state where the guide pin is slidable or provided with a ventilation gap,
The end surface of the main sliding portion and the inner end surface of the main guide hole are in close contact with each other, and the cooling air is intermittently connected from the air passage provided in the main sliding portion,
An electrode for electric resistance welding, characterized in that an exhaust passage extending from the boundary portion between the sub guide hole and the pin hole in the diameter direction of the electrode body and opening in the outer peripheral surface of the electrode body is formed.

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