Electrode cooling device

Abstract

To provide a spot welding system capable of maintaining the quality of each welding spot even when the welding work is performed while enhancing the productivity by shortening the moving time between the welding spots, and hardly causing the failure of equipment.SOLUTION: An electrode cooling device 20 includes a device body 2 having a holder member 27 for moving an electrode tip E by an industrial robot 10 and bringing it into contact, and four cooling units 3 for cooling the device body 2 having the holder member 27.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electrode cooling device capable of cooling an electrode tip attached to a welding gun of a spot welding machine after welding has been performed. [Background technology]

[0002] It has been known that in conventional spot welding systems, if the electrode tip attached to the welding gun of the spot welding machine is maintained at a high temperature during welding, the electrode tip is prone to deformation and wear, which has a significant impact on the welding quality. Therefore, as disclosed in Patent Document 1, for example, a chiller is connected to the spot welding machine, and cooling water is constantly circulated inside the electrode tip to prevent the electrode tip from being maintained at a high temperature.

[0003] However, in a process where spot welding is performed continuously, such as on an automobile production line, if an attempt is made to shorten the movement time between welding points in order to improve productivity, the electrode tip may not be sufficiently cooled before the next welding is performed, which could result in a deterioration in weld quality. To address this issue, it is conceivable to reduce the temperature of the cooling water circulated inside the electrode tip as much as possible to efficiently cool the electrode tip. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-111624 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if the temperature of the cooling water circulating inside the electrode tip is too low, condensation is likely to occur in the cooling water circulation path of the spot welder, which will have an adverse effect on the spot welder itself and its surrounding ancillary equipment. Thus, conventional spot welding systems have had the problem of making it difficult to simultaneously improve productivity and weld quality while preventing equipment failure.

[0006] The present invention has been made in view of the above points, and its object is to provide a spot welding system that can maintain the quality of each welding point even when performing welding work while shortening the movement time between welding points to increase productivity, and that is also less susceptible to equipment breakdowns. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention is characterized by being devised so that the electrode tip can be cooled from the outside when spot welding is performed.

[0008] Specifically, in a welding system in which a spot welding gun is configured to be movable by a gun moving means, the following measures were taken for an electrode cooling device that cools the electrode tip attached to the welding gun.

[0009] That is, the electrode cooling device of the first invention is characterized by comprising an apparatus main body having an electrode contact portion that moves and contacts the electrode tip using the gun moving means, and a cooling unit that cools the apparatus main body. The electrode cooling device configured in this manner acts to cool the electrode tip from the outside, and also acts to eliminate the need to lower the temperature of the cooling water circulating inside the electrode tip more than necessary.

[0010] The electrode cooling device of the second invention is characterized in that, in the first invention, the device main body is a metal body and the cooling unit is attached to the outer periphery centered on the center line of the device main body. The electrode cooling device configured in this manner acts to provide a structure in which the device body is gradually cooled from the outer periphery.

[0011] The electrode cooling device of the third invention is characterized in that, in the second invention, the device main body is a rectangular prism made of metal material, and the cooling unit is attached to each side of the rectangular prism except for one. The electrode cooling device configured in this manner functions to cool the entire device body, and also to facilitate access of the electrode tip to the electrode contact portion from a position where the cooling unit is not located.

[0012] The electrode cooling device of the fourth invention is characterized in that, in the third invention, the electrode contact portion is provided on the center line of the rectangular column and has a recess having a curved surface corresponding to the tip shape of the electrode tip. In the electrode cooling device configured as described above, when the electrode tip is brought into contact with the electrode contact portion, the distal end surface of the electrode tip comes into contact with the electrode contact portion over a wide area, and the electrode tip is cooled at the center of the device body, where the surrounding area is uniformly cooled.

[0013] The electrode cooling device of the fifth invention is characterized in that, in the fourth invention, the device body has a structure in which the thickness in the center line direction is thinner at the electrode contact portion than at the outer circumferential portion. In the electrode cooling device configured in this manner, when each cooling unit cools the peripheral portion of the device body, the central portion of the device body is cooled more quickly.

[0014] The electrode cooling device according to a sixth invention is any one of the first to fifth inventions, characterized in that the cooling unit includes a Peltier element whose heat absorption surface is in contact with the device body. The electrode cooling device configured in this way functions to cool the device body without using liquid or mechanical action, and also functions as a structure that transfers heat directly using electricity.

[0015] The electrode cooling device of the seventh invention is characterized in that, in the sixth invention, the cooling unit is attached to the heat dissipation surface of the Peltier element and is equipped with a heat dissipation part that dissipates heat emitted from the heat dissipation surface. The electrode cooling device configured in this manner functions to efficiently dissipate heat generated during operation of the Peltier element.

[0016] The electrode cooling device of the eighth invention is characterized in that, in the seventh invention, the heat dissipation section comprises a heat dissipation plate having a water channel formed therein and in contact with the heat dissipation surface of the Peltier element, and a chiller that circulates water through the water channel. In the electrode cooling device configured in this manner, the circulating cooling water acts to efficiently remove heat from the Peltier element through heat exchange.

[0017] The electrode cooling device of the 9th invention is characterized in that, in the 8th invention, the water channel has a spiral shape extending over the entire area of ​​the heat dissipation plate, centered on a line extending in the thickness direction of the heat dissipation plate. The electrode cooling device configured in this manner functions as if the cooling water channels are arranged over the entire area of ​​the heat rejection plate. [Effects of the Invention]

[0018] The electrode cooling device of the first invention allows the electrode tip to be cooled from the outside at a predetermined timing between welding operations when performing continuous spot welding. Therefore, the electrode tip can be returned to an appropriate temperature before it becomes too hot, eliminating the need to unnecessarily extend the travel time between welding operations, thereby maintaining weld quality while increasing productivity. Furthermore, shortening the travel time between welding operations does not require unnecessarily lowering the temperature of the cooling water circulating inside the electrode tip. This prevents condensation in the cooling water circulation path from adversely affecting the welding machine and surrounding ancillary equipment, allowing the spot welding system to be used without malfunction.

[0019] In the electrode cooling device of the second invention, the device body is gradually cooled from the outer periphery, which eliminates the need to, for example, form complex water channels inside the device body to circulate cooling water, thereby reducing the processing costs of the device body.

[0020] In the electrode cooling device of the third invention, the entire device body is cooled, so the electrode tip that contacts the electrode contact portion can be cooled evenly. Also, because the cooling unit is not disposed in a portion of the periphery of the device body, when the spot welding gun is brought close to the electrode cooling device, the electrode tip can easily access the electrode contact portion from a position where the cooling unit is not disposed, thereby allowing for efficient cooling work.

[0021] In the electrode cooling device of the fourth aspect of the invention, when the electrode tip is brought into contact with the electrode contact portion, the tip surface of the electrode tip comes into contact with the electrode contact portion over a wide area. Therefore, a wide area of ​​the electrode tip tip can be efficiently cooled. Furthermore, since the electrode tip is cooled at the center of the device body where the surrounding area is uniformly cooled, the entire area of ​​the electrode tip can be uniformly cooled.

[0022] In the electrode cooling device of the fifth invention, when each cooling unit cools the outer peripheral portion of the device body, the central portion of the device body is cooled more quickly, so that the electrode tip, which is in a high temperature state, can be cooled to the desired temperature in a short time.

[0023] The electrode cooling device of the sixth invention cools the device body without using liquid or mechanical action, making the device less susceptible to breakdown. In addition, the Peltier element is designed to transfer heat directly using electricity, making it an energy-efficient and energy-saving device.

[0024] In the electrode cooling device of the seventh aspect of the invention, the heat generated during operation of the Peltier element is efficiently dissipated, thereby preventing the Peltier element itself from becoming too hot and preventing a decrease in the cooling capacity of the Peltier element.

[0025] In the electrode cooling device of the eighth invention, the heat generated by the Peltier element can be efficiently removed by heat exchange using circulating cooling water, thereby preventing the Peltier element itself from becoming too hot and maintaining the cooling capacity of the device body even during continuous use.

[0026] In the electrode cooling device of the ninth invention, cooling water channels are arranged over the entire area of ​​the heat dissipation plate, so that the entire heat dissipation surface of the Peltier element is cooled evenly, and the entire Peltier element can be cooled efficiently. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a perspective view showing an electrode cooling device according to an embodiment of the present invention. [Figure 2] 1 is an exploded perspective view showing an electrode cooling device according to an embodiment of the present invention. [Figure 3] 1 is a plan view showing an electrode cooling device according to an embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 4 is a cross-sectional view taken along line VV in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0028] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following description of the preferred embodiment of the present invention is merely exemplary in nature.

[0029] 1 shows a welding system 1 according to an embodiment of the present invention. This welding system 1 includes an industrial robot 10 (gun moving means) having a spot welding gun 11 attached to the tip of its arm, and an electrode cooling device 20 that cools a pair of opposing electrode tips E attached to the spot welding gun 11. The spot welding gun 11 can be moved by the industrial robot 10.

[0030] The electrode cooling device 20 includes a device main body 2 that is a pentagonal prism made of copper, and four cooling units 3 attached to four side surfaces 2a of the device main body 2. That is, each cooling unit 3 is attached to each side surface 2a of the pentagonal prism except for one.

[0031] As shown in Figures 1 to 3, the device main body 2 is fixed to a stand (not shown) with the center line C1 extending vertically, and each cooling unit 3 is located on the outer periphery of the device main body 2, centered on the center line C1.

[0032] An upper step surface portion 21 that is recessed in a stepped shape is provided on the upper surface 2b of the device main body 2, and this upper step surface portion 21 is formed from the central part of the upper surface 2b to the side surface 2a where the cooling unit 3 is not attached.

[0033] An upper protrusion 22 is provided in the outer region of the upper half of the device body 2, protruding upward and extending in a substantially C-shape along the upper step surface .

[0034] 4 and 5, a lower stepped surface portion 23 is provided on the lower surface 2c of the device body 2. The lower stepped surface portion 23 is formed from the center of the lower surface 2c to the side surface 2a on which the cooling unit 3 is not attached, and has a shape symmetrical to the upper stepped surface portion 21 in the vertical direction.

[0035] As shown in Figures 1 to 3, a lower protrusion 24 is provided in the outer region of the lower half of the device main body 2, protruding downward and extending in an approximately C-shape along the lower step surface 23, and this lower protrusion 24 has a shape symmetrical to the upper protrusion 22 in the vertical direction.

[0036] In other words, the device main body 2 has a structure in which the thickness in the direction in which its center line C1 extends is thinner in the main body inner region 2B consisting of the upper step surface portion 21 and the lower step surface portion 23 than in the main body outer region 2A consisting of the upper protrusion portion 22 and the lower protrusion portion 24.

[0037] Four insertion holes 25 are formed at predetermined intervals in the outer area 2A of the device main body 2, through which bolts B (see Figure 5) can be inserted, and the device main body 2 is fixed to a stand (not shown) by inserting a bolt B into each of these insertion holes 25.

[0038] As shown in Figures 2, 4 and 5, a mounting hole 26 is formed in the center of the device main body 2, i.e., in the main body inner region 2B, penetrating vertically, and the inner circumferential surface of the mounting hole 26 has a shape that gradually reduces in diameter as it goes downward.

[0039] The device main body 2 includes a thick, disk-shaped copper holder member 27 (electrode contact portion), and the holder member 27 has a tapered outer circumferential surface that gradually reduces in diameter as it extends downward.

[0040] The holder member 27 can be fitted into the mounting hole 26 from above, and when fitted into the mounting hole 26, is positioned on the center line C1.

[0041] An upper recess 28 having an upper curved surface 28a that gradually reduces in diameter as it goes downward is formed on the upper surface of the holder member 27, and the upper curved surface 28a has a shape that corresponds to the shape of the tip of the electrode tip E.

[0042] On the other hand, a lower recess 29 having a lower curved surface 29a whose diameter gradually decreases as it goes upward is formed on the lower surface of the holder member 27, and the lower curved surface 29a has a shape corresponding to the tip shape of the electrode tip E.

[0043] As shown in Figure 4, when the industrial robot 10 moves each electrode tip E to a position above or below the holder member 27 and brings them close to each other, each electrode tip E fits into the upper curved surface 28a and the lower curved surface 29a, respectively, and comes into contact with the holder member 27.

[0044] 1 to 3, the cooling unit 3 includes a thin rectangular Peltier element 4, a rectangular copper heat dissipation plate 5 corresponding to the Peltier element 4, and a chiller 6 for circulating cooling water. The heat dissipation plate 5 and chiller 6 constitute a heat dissipation section 7 of the present invention.

[0045] The Peltier element 4 has a heat absorbing surface 4a in contact with the side surface 2a of the device body 2, and a heat dissipating surface 4b in contact with the surface of the heat exhaust plate 5 on the device body 2 side.

[0046] A first wiring 4c and a second wiring 4d are connected to the heat absorption surface 4a and the heat dissipation surface 4b, respectively, so that when a current is passed through the Peltier element 4, heat is absorbed on the heat absorption surface 4a and dissipated on the heat dissipation surface 4b.

[0047] That is, when each Peltier element 4 is operated, the entire device body 2 including the holder member 27 is cooled.

[0048] The heat dissipation plate 5 is attached to the heat dissipation surface 4b of the Peltier element 4. The heat dissipation plate 5 includes a first plate 8 made of copper and positioned on the Peltier element 4 side, and a second plate 9 made of copper and positioned on the side away from the Peltier element 4.

[0049] As shown in Figure 2, a first concave groove portion 8a is formed on the surface of the first plate 8 facing the second plate 9, extending in a spiral shape over almost the entire area of ​​the first plate 8, centered on a line C2 extending in the thickness direction of the heat dissipation plate 5.

[0050] A second groove 8b extending in an annular shape is formed around the first groove 8a in the first plate 8, and an O-ring 8c for preventing water leakage is fitted into the second groove 8b.

[0051] The second plate 9 is fixed to the first plate 8 with a plurality of screws N. When the second plate 9 is fixed to the first plate 8, the open side of the first groove portion 8a is covered, and a water channel W is formed inside the heat dissipation plate 5.

[0052] A water supply hole 9a is formed through the center of the second plate 9, to which the first pipe 6a extending from the chiller 6 is connected. The water supply hole 9a is located at a position corresponding to one end of the water channel W.

[0053] In addition, a drainage hole 9b is formed through the second plate 9 at a position near one horizontal end thereof to which the second pipe 6b extending from the chiller 6 is connected, and the drainage hole 9b is located at a position corresponding to the other end of the water channel W.

[0054] When the chiller 6 is operated, cooling water is supplied from the first pipe 6a to one end of the water passage W via the water supply hole 9a, passes through the water passage W, and is drained from the other end of the water passage W to the second pipe 6b via the drainage hole 9b. In other words, the chiller 6 circulates cooling water through the water passage W.

[0055] When cooling water is circulated through the water channel W by the chiller 6, the heat dissipation plate 5 dissipates the heat emitted from the heat dissipation surface 4b of the Peltier element 4.

[0056] Next, the operation of the welding system 1 when the electrode tip E is cooled by the electrode cooling device 20 will be described in detail.

[0057] First, when the electrode cooling device 20 is turned on, current flows through the Peltier element 4 of each cooling unit 3, cooling the device main body 2, and the chiller 6 circulates cooling water through the water channel W of the heat dissipation plate 5, dissipating the heat generated by the Peltier element 4.

[0058] Next, when a predetermined timing arrives while spot welding is being performed continuously with the spot welding gun 11, the industrial robot 10 moves the spot welding gun 11 to the electrode cooling device 20, as shown in FIG. 4.

[0059] The industrial robot 10 brings the spot welding gun 11 close to the device body 2 from the side 2a of the device body 2 on which the cooling unit 3 is not attached. Then, the industrial robot 10 moves the spot welding gun 11 horizontally until the electrode tips E are positioned above and below the holder member 27, and then brings the electrode tips E close to each other so that they fit into the upper recess 28 and the lower recess 29, respectively.

[0060] Then, the distal end side of each electrode tip E comes into contact with the upper curved surface 28a and the lower curved surface 29a, respectively, and is cooled from the outside by the holder member 27, which is cooled by the Peltier element 4.

[0061] Each electrode tip E is kept fitted in the upper recess 28 and the lower recess 29 until the electrode tip E reaches the desired temperature, and after a predetermined time has elapsed, the industrial robot 10 separates each electrode tip E from the upper recess 28 and the lower recess 29, respectively, to complete the cooling operation of each electrode tip E.

[0062] As described above, according to the embodiment of the present invention, when spot welding is performed continuously, the electrode tip E can be cooled from the outside at a predetermined timing between welding operations. Therefore, the electrode tip E can be returned to an appropriate temperature before it becomes too hot, and it is no longer necessary to make the movement time between welding operations longer than necessary, so that it is possible to maintain welding quality while increasing productivity.

[0063] Furthermore, in order to shorten the movement time between welding processes, there is no need to lower the temperature of the cooling water circulating inside the electrode tip E more than necessary. This prevents condensation from forming in the cooling water circulation path, which can adversely affect the welding equipment and its surrounding ancillary equipment, allowing the equipment in the welding system 1 to be used without breakdown.

[0064] Furthermore, since the device body 2 is made of copper and each cooling unit 3 is attached to the outer periphery of the device body 2 around the center line C1, the device body 2 is gradually cooled starting from the outer periphery. Therefore, in order to cool the device body 2, it is not necessary to form, for example, complex water channels for circulating cooling water inside it, and the processing costs of the device body 2 can be kept low.

[0065] Furthermore, because the device body 2 is a pentagonal prism and each cooling unit is attached to each side surface 2a of the pentagonal prism except for one, the entire device body 2 is cooled, and the electrode tip E in contact with the holder member 27 can be cooled evenly. Furthermore, because the cooling units 3 are not disposed in a portion of the periphery of the device body 2, when the spot welding gun 11 is brought close to the electrode cooling device 20, the electrode tip E can easily access the holder member 27 from a position where the cooling units 3 are not disposed, and the cooling operation can be performed efficiently.

[0066] Furthermore, because the holder member 27 is provided on the center line C1 of the device body 2 and has an upper curved surface 28a and a lower curved surface 29a that correspond to the shape of the tip of the electrode tip E, when the electrode tip E is brought into contact with the holder member 27, the tip surface of the electrode tip E comes into contact with the holder member 27 over a wide area. This allows efficient cooling over a wide area of ​​the tip of the electrode tip E. Furthermore, because the electrode tip E is cooled at the center position of the device body 2 where the surrounding area is uniformly cooled, the entire area of ​​the electrode tip E can be uniformly cooled.

[0067] Furthermore, the device main body 2 has a structure in which the thickness in the direction of extension of its center line C1 is thinner in the main body inner region 2B where the holder member 27 is located than in the main body outer region 2A which is the outer peripheral portion of the device main body 2. Therefore, when each cooling unit 3 cools the outer peripheral portion of the device main body 2, the central portion of the device main body 2 is cooled more quickly, and the electrode tip E in a high temperature state can be cooled to the desired temperature in a short time.

[0068] Furthermore, because the cooling unit 3 is equipped with a Peltier element 4 that cools the device body 2, the device body 2 is cooled without using liquid or mechanical operation. This makes it possible to make the electrode cooling device 20 less prone to breakdowns. Furthermore, because the Peltier element 4 is structured to transfer heat directly using electricity, the electrode cooling device 20 is energy efficient and can be made energy-saving.

[0069] Furthermore, the heat generated during operation of the Peltier element 4 is efficiently discharged by the heat dissipation section 7. This prevents the Peltier element 4 itself from becoming too hot, and prevents a decrease in the cooling capacity of the Peltier element 4.

[0070] Furthermore, the heat dissipation unit 7 is equipped with a heat dissipation plate 5 having a water channel W formed therein and a chiller 6 that circulates cooling water through the water channel W, so that the heat emitted from the Peltier element 4 can be efficiently dissipated through heat exchange with the cooling water circulated by the chiller 6. This prevents the Peltier element 4 itself from becoming too hot, and makes it possible to maintain the cooling capacity of the device main body 2 even during continuous use.

[0071] Furthermore, since the cooling water channels W are arranged over the entire area of ​​the heat dissipation plate 5, the entire heat dissipation surface 4b of the Peltier element 4 is cooled evenly, and the entire Peltier element 4 can be cooled efficiently.

[0072] In the embodiment of the present invention, an industrial robot 10 is used as a structure for moving the spot welding gun 11, but this is not limited to this, and the movement may also be achieved using an electric actuator, a fluid pressure cylinder, or the like.

[0073] Furthermore, in the embodiment of the present invention, the device body 2 is a pentagonal prism, but it may be another type of prism, such as a quadrangular prism or a hexagonal prism.

[0074] Furthermore, in the embodiment of the present invention, the device body 2 and the heat dissipation plate 5 are made of copper, but they may be made of other metals.

[0075] Furthermore, in the embodiment of the present invention, the cooling unit 3 is attached to the outer periphery of the device body 2, but it may be attached to a part of the upper surface 2b or lower surface 2c of the device body 2.

[0076] Furthermore, in the embodiment of the present invention, the device body 2 is cooled by the Peltier element 4, but it may be cooled by other structures, for example, by a heat exchanger using a cooling refrigerant.

[0077] In addition, in the embodiment of the present invention, the main body inner region 2B is thinner than the main body outer region 2A, but they may have the same thickness.

[0078] In addition, in the embodiment of the present invention, the water channel W of the heat dissipation plate 5 has a spiral shape, but it may also have a zigzag shape, or any other shape as long as the cooling water passing through the water channel W can cool the entire area of ​​the heat dissipation plate 5.

[0079] In the embodiment of the present invention, the cooling units 3 are attached to all but one of the side surfaces 2a of the device body 2, but the cooling units 3 may be attached to all of the side surfaces 2a.

[0080] In addition, in the embodiment of the present invention, each Peltier element 4 is cooled by a heat dissipation plate 5 having a water channel W, but this is not limited to this, and for example, cooling may be performed by an air-cooling fan, or natural air cooling may be performed without attaching anything to the heat dissipation surface 4b. [Industrial Applicability]

[0081] The present invention is suitable for an electrode cooling device that can cool an electrode tip attached to a welding gun of a spot welding machine after welding has been performed. [Explanation of symbols]

[0082] 1...Welding system 2...Device main body 2A...Outer area of ​​main body 2B...Inner area of ​​main body 2a...Side surface 2b...Top surface 2c...Bottom surface 3...Cooling unit 4...Peltier element 4a...Heat absorption surface 4b...Heat dissipation surface 4c...First wiring 4d...Second wiring 5...Heat exhaust plate 6...Chiller 6a...First piping 6b...Second piping 7...Heat exhaust section 8...First plate 8a...First grooved section 8b...Second grooved section 8c...O-ring 9...Second plate 9a...Water supply hole 9b...Drainage hole 10...Industrial robot (gun moving means) 11...Spot welding gun 20...Electrode cooling device 21...Upper stepped surface 22...Upper protruding section 23...Lower stepped surface 24...Lower protruding section 25...Insertion hole 26...Mounting hole 27...Holder member (electrode contact portion) 28...Upper recess 28a...Upper curved surface 29...Lower recess 29a...Lower curved surface B...Bolt C1...Center line C2...Line extending in the thickness direction of the heat dissipation plate E...Electrode tip N...Screw W...Water channel

Claims

1. In a welding system in which a spot welding gun is configured to be movable by a gun moving means, an electrode cooling device for cooling an electrode tip attached to the spot welding gun, comprising: an apparatus main body having an electrode contact portion that is moved and brought into contact with the electrode tip by the gun moving means; and a cooling unit that cools the device body.

2. 2. The electrode cooling device according to claim 1, the device body is a metal body, The electrode cooling device is characterized in that the cooling unit is attached to an outer periphery of the device body, the outer periphery being centered on the center line of the device body.

3. 3. The electrode cooling device according to claim 2, the device body is a prismatic body, An electrode cooling device characterized in that the cooling units are attached to each side surface of the prismatic body except for one.

4. 4. The electrode cooling device according to claim 3, The electrode cooling device is characterized in that the electrode contact portion is provided on the center line of the device body and has a recess having a curved surface corresponding to the tip shape of the electrode tip.

5. 5. The electrode cooling device according to claim 4, The electrode cooling device is characterized in that the device body has a structure in which the thickness in the center line direction is thinner at the electrode contact portion than at the outer periphery.

6. 6. The electrode cooling device according to claim 1, The electrode cooling device is characterized in that the cooling unit includes a Peltier element whose heat absorption surface is in contact with the device body.

7. 7. The electrode cooling device according to claim 6, The cooling unit is attached to the heat dissipation surface of the Peltier element and includes a heat dissipation part that dissipates heat emitted from the heat dissipation surface.

8. 8. The electrode cooling device according to claim 7, The electrode cooling device is characterized in that the heat dissipation unit comprises a heat dissipation plate having a water channel formed therein and in contact with the heat dissipation surface of the Peltier element, and a chiller that circulates water through the water channel.

9. 9. The electrode cooling device according to claim 8, The electrode cooling device is characterized in that the water channel has a spiral shape extending over the entire area of ​​the heat dissipation plate, with a line extending in the thickness direction of the heat dissipation plate as its center.

Images