JP5717274B2 - Resistance welding equipment - Google Patents

Description

  The present invention relates to a resistance welding apparatus that performs resistance welding such as spot welding, and more particularly to a structure of a power feeding unit that supplies current from a fixed portion including a transformer to a pressure shaft including an electrode.

  Resistance welding is a method in which a current is applied in a state where pressure is applied to a contact portion between two workpiece members, and these are welded by resistance heat generated. In this welding, a method of welding by laminating relatively thin plate materials is called lap resistance welding. Among them, spot welding for spot-welding stacked plate materials is widely used in the automobile industry.

  Spot welding is classified into two types, a direct method and an indirect method, depending on the position of the electrode with respect to the work member. The direct method is a method in which electrodes are arranged on both sides of a work member, and has been performed for a long time. The indirect method is a method in which two electrodes are arranged on one side of a work member, and is a relatively new method.

  Also, the method called the series method is similar to the indirect method, in which two electrodes are arranged on one side of the work member, but in that the spot welding is performed in the vicinity of the two electrodes, what is the indirect method? Different. More recently, a welding method in which two electrodes are coaxially arranged on one side of a work member has been performed.

  In this specification, for the sake of convenience, resistance welding in which electrodes are arranged on both sides of a workpiece member is referred to as “both-side resistance welding”, and resistance welding in which electrodes are arranged on one side of the workpiece member is referred to as “single-side resistance welding”. Patent Document 1 discloses a one-side resistance welding apparatus in which two electrodes are arranged coaxially.

  The resistance welding apparatus 110 is shown in FIG. 4, and the welding machine main body 111 is shown in FIG. The resistance welding apparatus 110 includes a base 170 that is a fixed portion, and a table 171 on which a work member is placed and a transformer 120 that supplies electric power are fixed to the base 170. The resistance welding apparatus 110 includes an outer electrode 130 that is fixed to the outer electrode plate 132 and has a cylindrical tip, and a rod-shaped inner electrode that is fixed to the inner electrode plate 142 and positioned inside the cylindrical outer electrode 130. 140, the outer electrode 130 and the inner electrode 140 are arranged coaxially.

  The outer electrode plate 132 can be moved up and down by an outer pressure shaft 131 driven by an air cylinder 150, and the inner electrode plate 142 can be moved up and down by an inner pressure shaft 141 driven by an air cylinder 160. It has become. That is, the outer electrode plate 132 and the inner electrode plate 142 are movable relative to the base 170, and the outer electrode 130 and the inner electrode 140 are attached to the work member placed on the table 171. It is possible to press with a predetermined force.

  As a result, it is necessary to use a flexible power supply member to supply power from the transformer 120 fixed to the base 170 to the outer electrode plate 132 and the inner electrode plate 142 that move relative to the base 170. It becomes. In this resistance welding apparatus 110, flexible cables 123 and 124 are used as power supply members. In addition, a power supply member called a “shunt” formed by stacking thin plates to be flexible is also used.

  However, such a power supply structure is liable to be damaged by long-term use, and there is a problem that stable power supply to the outer pressure shaft 131 and the inner pressure shaft 141 cannot be performed. Moreover, there exists a problem that the shape of the resistance welding apparatus 110 whole becomes large, and it is difficult to form in a compact structure.

JP 2002-239748 A

  Accordingly, an object of the present invention is to improve the power supply structure for supplying power from the transformer to the pressure shaft in a resistance welding apparatus that performs spot welding or the like, and can be applied without being damaged even during long-term use. An object of the present invention is to provide a resistance welding apparatus capable of stably supplying power to a pressure shaft. It is another object of the present invention to provide a resistance welding apparatus capable of reducing the weight and reducing the manufacturing cost while forming the overall shape of the resistance welding apparatus compactly.

According to a first aspect of the present invention, a resistance welding apparatus includes a fixed portion having a power supply transformer, a power supply housing fixed to the fixed portion, and the axial direction with respect to the power supply housing. movably formed on the a pressing axis that moves relative to the fixed part, which has electrodes attached to the tip of the pressure application shaft, the pressure application shaft is in said power supply housing one A resistance welding device in which a coil spring is deformed and housed in a ring-shaped space formed by the groove, the depth D of the groove being outside the coil spring. The outer periphery of the coil spring is in contact with the power supply housing at a number of points, and the inner periphery of the coil spring is connected to the pressure shaft and a number of points. Contact is, the pressure application shaft and the feed housing, employs a means that is electrically connected via the coil spring.

The resistance welding apparatus according to claim 2 of the present invention, in the resistance welding apparatus according to claim 1, wherein the feed housing, the pressure application shaft, the electrode, and a pre-logger yl consists spring feed structure 2 A set of means is used. Moreover, the resistance welding apparatus according to claim 3 of the present invention employs means in which the two pressure shafts are arranged coaxially in the resistance welding apparatus according to claim 2. Furthermore, the resistance welding apparatus according to claim 4 of the present invention employs a means in which either one of the two pressure shafts is biased by a spring in the resistance welding apparatus according to claim 2 or 3. ing.

  Since the resistance welding apparatus of the present invention employs the above-described feeding structure, it is possible to stably feed power to the pressure shaft without being damaged even during long-term use. In addition, the overall shape of the resistance welding apparatus can be simplified, and the resistance welding apparatus can be reduced in weight or compactly. In addition, high-precision processing is not required for manufacturing, and the manufacturing cost can be reduced. And it can be widely applied to both-side resistance welding and one-side resistance welding.

It is a general | schematic whole side view which shows an example of the resistance welding apparatus of this invention. It is a schematic sectional drawing which shows the welding machine main body of the resistance welding apparatus of FIG. A diagram of coils springs, (a) shows the variation of the Turkey-yl spring put the present invention, shows a coil spring before the deformation (b). It is a general | schematic whole side view which shows an example of the conventional resistance welding apparatus. It is a schematic sectional drawing which shows the welding machine main body of the resistance welding apparatus of FIG.

  An example of the resistance welding apparatus of the present invention is shown in FIG. 1, and its main body is shown in FIG. The resistance welding apparatus 10 uses a bracket 70 including a power supply transformer 20 as a fixed portion. The outer power feeding housing 32 and the inner power feeding housing 42 are fixedly attached to the bracket 70, and power is supplied from the transformer 20 to each of them.

  The transformer 20 includes secondary-side terminals 21 and 22. The outer power supply housing 32 is connected to the terminal 21 via the outer power supply bar 23. The inner power supply housing 42 is connected to the terminal 22 via the inner power supply bar 24. Here, the outer power supply bar 23 and the inner power supply bar 24 do not need to use a flexible power supply member, and can be formed of a rigid body such as a copper rod.

  An outer pressure shaft 31 is inserted into the outer power supply housing 32, and an outer electrode 30 is attached to the tip of the outer pressure shaft 31. The outer pressing shaft 31 is formed so as to be movable in the axial direction with respect to the outer power supply housing 32, and is urged toward the outer electrode 30 by a spring 50. The present invention improves the power supply structure for supplying power from the outer power supply housing 32 to the outer electrode 30 via the outer pressure shaft 31.

The outer power supply housing 32 has a ring-shaped groove 35 formed therein so as to surround a part of the outer pressure shaft 31 to be inserted, and a deformed coil spring 36 is accommodated in the groove 35. Has been. The relationship between the width W and the depth D of the groove 35 is formed such that W is larger than D, for example, W is formed to be about twice as large as D. The outer diameter of the coils spring 36 is formed slightly larger than the width W of the groove 35. In this way, coils spring 36 in the groove 35, it comes into contact with the outer feed housing 32 at multiple points.

A specific example of the deformed coil spring 36 is shown in FIG. FIG. 3B shows an ordinary coil spring 37 formed in a donut shape. The inner and outer circumferences of the normal of the coil spring 37 by the addition of opposite forces, as shown by the arrows in FIG. 3 (b), it is Rukoto be deformed as shown in FIG. 3 (a). That is, the coil spring 36 can be deformed by applying a force that narrows the space between the inner periphery and the outer periphery.

Outer pressure shaft 31, while being inserted into the outer feed housing 32 is formed so as to contact at multiple points with coils springs 36. Thus, coils spring 36 has its outer peripheral portion is in contact at multiple points with the outer feed housing 32, so that its inner peripheral portion is in contact at multiple points with the outer pressure shaft 31.

The outer feed housing 32 and the outer pressure shaft 31, the coils spring 36 which is deformed, so that receives a pressing force of the spring at each contact point. Thus, the outer feeder housing 32 and the outer pressing axis 31 will be electrically connected through the coils springs 36.

  Thus, in the resistance welding apparatus 10 of the present invention, it is possible to supply electric power from the fixed portion including the transformer 20 to the outer pressure shaft 31 that moves relative to the fixed portion with a simple structure. . This power feeding structure is excellent in durability and can be used stably for a long period of time. Moreover, the shape of the apparatus including the outer power supply housing 32 and the outer pressure shaft 31 can be formed compactly.

  On the other hand, an inner pressure shaft 41 is inserted into the inner power supply housing 42, and an inner electrode 40 is attached to the tip of the inner pressure shaft 41. The inner pressure shaft 41 is formed to be movable in the axial direction with respect to the inner power supply housing 42, and is urged toward the inner electrode 40 by the air cylinder 60. The present invention can improve the power feeding structure for supplying power from the inner power feeding housing 42 to the inner pressure shaft 41.

The inner power supply housing 42 includes a cylinder head 43 and a cover 44. A ring-shaped groove 45 is formed inside the inner power supply housing 42 so as to surround a part of the inner pressure shaft 41 to be inserted, and a deformed coil spring 46 is accommodated in the groove 45. Has been. As the deformed coil spring 46, the same one as shown in FIG. 3A can be used.

The relationship between the width W and the depth D of the groove 45 is such that W is larger than D, for example, W is formed to be about twice as large as D. The outer diameter of the coils spring 46 is formed slightly larger than the width W of the groove 45. By doing so, co-yl spring 46 in the groove 45, comes into contact at multiple points with the inner feed housing 42.

Inner pressure shaft 41, while being inserted inside the feed housing 42 are formed so as to contact at multiple points with coils springs 46. Thus, coils spring 46 is in contact its peripheral portion with a number of points inside the feed housing 42, so that its inner peripheral portion is in contact with the inner pressure shaft 41 in a number of respects.

Then, the inner power supply housing 42 and the inner pressure shaft 41 receive a pressing force by the spring at each contact point by the deformed coil spring 46. Thus, the inner power supply housing 42 and the inner pressing axis 41 will be electrically connected through the coils springs 46.

  As described above, in the resistance welding apparatus 10 of the present invention, it is possible to supply power from the fixed portion including the transformer 20 to the inner pressure shaft 41 that moves relative to the fixed portion with a simple structure. . This power feeding structure is excellent in durability and can be used stably for a long period of time. Moreover, the shape of the apparatus including the inner power supply housing 42 and the inner pressure shaft 41 can be formed in a compact manner.

Next, urging of the outer pressure shaft 31 and the inner pressure shaft 41 will be described.
The outer pressure shaft 31 is biased toward the outer electrode 30 by the spring 50. That is, the spring 50 is inserted through the spacer 51 between the inner power supply housing 42 and the outer pressure shaft 31 which are fixed portions, and the inner power supply housing 42 and the outer electrode 30 are urged so as to be separated from each other. doing. For this reason, by bringing the bracket 70 close to the work member, an appropriate pressing force can be applied between the outer electrode 30 and the work member.

  The inner pressure shaft 41 can be biased toward the inner electrode 40 by the air cylinder 60. In the air cylinder 60, one end of a cylindrical cylinder 61 is fixed and closed by the inner power supply housing 42, and the other end is closed by an end cover 62 to form a cylinder chamber 63 inside. At the same time, an inner pressure shaft 41 is provided through the inner power supply housing 42 and the end cover 62.

  A piston 64 is attached to the inner pressure shaft 41. The cylinder chamber 63 is provided with an air supply port 65 and an air discharge port 66. Therefore, the inner pressure shaft 41 can be biased toward the inner electrode 40 by supplying high-pressure air from the air supply port 65. The inner pressure shaft 41 has a structure in which the inside thereof is cooled with water, and includes a water supply port 81 and a water discharge port 82.

  In the welding machine body 11, the outer electrode 30 and the inner electrode 40 need to be electrically insulated. In FIG. 2, both electrodes are insulated by an insulating cover 91, insulating bushes 92, 93 and the like.

  As described above, the resistance welding apparatus 10 in which two electrodes are arranged coaxially and performs one-side resistance welding has been described as an embodiment of the present invention. And it showed that this invention concerns on the electric power feeding structure of a resistance welding apparatus. Therefore, the present invention can be widely applied to resistance welding apparatuses that perform resistance welding on both sides (direct method) and resistance welding apparatuses that perform other one-side resistance welding (indirect method, series method).

  In any case, it can be used stably over a long period of time, and the resistance welding apparatus can be made compact and light. Therefore, it is optimal as a resistance welding apparatus for robots and can be widely used in the automobile industry and the like.

10 resistance welding equipment
20 transformers
30 outer electrode
31 outer pressure shaft 32 outside the feed housing 35 grooves 36 and 46 coils springs
40 inner electrode
41 inner pressure shaft 42 inside the feed housing 45 groove 50 sprint grayed

Claims (4)

A fixed part having a transformer for power supply;
A power supply housing fixed to the fixed portion;
A pressure shaft that is inserted into the power supply housing, is formed to be movable in the axial direction with respect to the power supply housing, and moves relative to the fixed portion;
Having an electrode attached to the tip of the pressure shaft;
A ring-shaped groove surrounding a part of the pressure shaft is formed in the power supply housing,
A resistance welding apparatus in which a coil spring is deformed and stored in a ring-shaped space formed by the groove,
A depth D of the groove is formed smaller than an outer diameter of the coil spring;
The outer periphery of the coil spring is brought into contact with the power supply housing at a number of points, and the inner periphery of the coil spring is brought into contact with the pressure shaft at a number of points.
Resistance welding apparatus in which the pressure application shaft and the feed housing, characterized that you have been electrically connected via the coil spring. The feeder housing, the pressure application shaft, the electrode, and a resistance welding device of claim 1, the pre-logger yl consists spring feeding structure and characterized in that it comprises two sets. The resistance welding apparatus according to claim 2, wherein the two pressure shafts are arranged coaxially. 4. The resistance welding apparatus according to claim 2, wherein one of the two pressure shafts is biased by a spring. 5.

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