JP2008119747A - Spot welding inspecting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spot welding inspecting apparatus capable of evenly cooling a gun tip, stabilizing measurement with an ultrasonic sensor, and reducing thermal impact on the ultrasonic sensor. <P>SOLUTION: The spot welding inspecting apparatus 10 is configured to make cooling water flow in order from a first, second, and third flow passage 35, 36, 37. In the circumferential and longitudinal directions of these three passages 35, 36, 37, there is no large obstacle of disturbing the flow. Since the cooling water has no inclination of flowing in a fixed direction, the gun tip 16 can be evenly cooled. Also, the columnar reflective-type ultrasonic sensor 23 is in constant contact with the cooling water and free from temperature change by warm water, stabilizing the measurement with the ultrasonic sensor 23 and also reducing deterioration of the sensor 23 caused by thermal impact. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an improvement in a spot welding inspection apparatus capable of inspecting a welded portion with an ultrasonic sensor built in a spot welding gun.

  In spot welding, for example, a melted and solidified weld metal generated at the contact portion between two steel plates after welding is called a nugget, and the joint strength of the welded portion is evaluated by a nugget diameter indicating the size of the nugget.

As a nugget diameter measuring device using a nondestructive inspection method in an inspection after welding, an electrode having an ultrasonic probe therein has been proposed (for example, see Patent Document 1).
JP 2005-527374 A (FIGS. 1 and 2)

Patent document 1 is demonstrated based on the following figure.
FIG. 15 is a diagram for explaining the basic configuration of the prior art. The welding electrode 100 is connected to a hollow shaft 102 to which the welding cap 101 is attached at the tip and a connection pad 104 placed on the inner bottom surface 103 of the welding cap 101. An ultrasonic probe 106 built in the welding cap 101 and the distal end portion 105 of the hollow shaft 102, a probe holder 107 for holding the ultrasonic probe 106 from the rear and inserting it into the hollow shaft 102, and the probe holder 107 And a signal line 109 extending from the rear end of the ultrasonic probe 106 to the top of the figure and inserted into the probe holder 107 and the cooling water pipe 108.

  In the welding electrode 100 of Patent Document 1, the cooling water flows from the rear end portion 111 of the cooling water pipe 108 as indicated by the arrow, passes through the periphery of the ultrasonic probe 106 via the inside of the probe holder 107, and is welded. The flow direction is changed at the inner bottom portion of 101, and this time, it flows along the partition plate 112 attached to the periphery of the ultrasonic probe 106 and the lower portion of the probe holder 107, and flows out from the rear end portion 113 of the hollow shaft 102. The welding electrode 100 can be cooled by such a flow of cooling water.

  The present inventors performed spot welding using a welding electrode having a structure similar to that of the welding electrode 100 of Patent Document 1, and immediately inspected the joint. As a result, it has been found that the cooling water flowing inside the welding electrode 100 flows in a certain direction along the partition plate 112 and thus the cooling of the welding cap 101 is uneven.

  At this time, the cooling water present inside the welding electrode 100 receives the heat from the welded part without passing through the cooling water (cooling water side) where the cooling water passes and is actively cooled. The ultrasonic probe 106 is soaked in both the cold water side and the hot water side because it is divided into a side where the cooling is insufficient (the hot water side). Therefore, the ultrasonic probe 106 may deteriorate in measurement accuracy and decrease in durability due to thermal shock due to heat transmitted from the hot water side.

  In order to improve the above-mentioned problems, the welding electrode (gun tip) is not unevenly cooled, and the welding electrode can prevent deterioration of measurement accuracy of the ultrasonic probe (ultrasonic sensor) and deterioration of durability due to thermal shock ( Development of spot welding inspection equipment is required.

  In addition, in FIG. 2 of patent document 1, the welding electrode is aiming at contact | adherence with the pad 16 and the welding cap 12 by pressing the probe 14 with a spring element. However, the pressure applied by the spring element may cause insufficient contact between the pad 16 and the welding cap 12, which may hinder the transmission of ultrasonic signals.

  Therefore, development of a welding electrode (spot welding inspection apparatus) that can improve the stability of transmission of ultrasonic signals is required.

  It is an object of the present invention to provide a spot welding inspection apparatus that can cool a gun tip without unevenness and can realize stabilization of measurement by an ultrasonic sensor and reduction of thermal shock to the ultrasonic sensor. To do.

  Moreover, this invention makes it a subject to provide the spot welding inspection apparatus which can improve the stability of transmission of an ultrasonic signal.

  According to a first aspect of the present invention, there is provided a spot welding inspection apparatus in which an ultrasonic sensor is built in a spot welding gun and a welded portion formed by the spot welding gun can be inspected by the ultrasonic sensor. The inspection apparatus includes an outer cylinder that is an external component of the spot welding gun, a cap-shaped gun tip that is fitted to one end of the outer cylinder, a signal transmission component that is built in the gun chip and transmits a signal, and the signal transmission component A cylindrical ultrasonic sensor having one end in close contact with, an inner cylinder inserted into the outer cylinder to hold down the cylindrical ultrasonic sensor, a through hole provided in a lower portion of the inner cylinder, A partition cylinder that surrounds the through-hole and is inserted into a gap between the cylindrical ultrasonic sensor and the outer cylinder, and a tip of which reaches the signal transmission component, and the penetration cylinder from the inside of the inner cylinder A first flow path formed between the inner cylinder and the partition cylinder through a hole; a second flow path formed in the gun tip so as to go around a tip of the partition cylinder; and the outer cylinder And a third channel formed between the first and second partition channels, and the coolant can flow in the order of the first channel, the second channel, and the third channel. Features.

  The invention according to claim 2 is characterized in that the second flow path is composed of a plurality of grooves formed in the outer peripheral surface of the signal transmission component.

  In the invention according to claim 3, in the spot welding inspection apparatus in which an ultrasonic sensor is built in a spot welding gun and a welded portion formed by the spot welding gun can be inspected by the ultrasonic sensor, the spot welding is performed. The inspection apparatus includes a gun tip that contacts the workpiece, the ultrasonic sensor that transmits an ultrasonic signal to the workpiece, a built-in gun tip, a front end that contacts the gun chip, and a rear end that contacts the ultrasonic sensor. A signal transmission component, and the signal transmission component includes an external thread portion on the outer peripheral surface that is engaged with the screw portion so as to be provided on the inner peripheral surface of the gun tip.

  In the invention according to claim 4, in the spot welding inspection apparatus in which an ultrasonic sensor is built in a spot welding gun and a welded portion formed by the spot welding gun can be inspected by the ultrasonic sensor, the spot welding is performed. The inspection apparatus includes a shank, a gun tip that engages with the tip of the shank and abuts against the workpiece, the ultrasonic sensor that transmits an ultrasonic signal to the workpiece, and a built-in gun tip and the tip contacts the gun tip. A contact transmission rear end contacting the ultrasonic sensor, and a tip of the shank presses a rear end of the signal transmission component.

  The invention according to claim 1 is configured such that the coolant can flow in the order of the first flow path, the second flow path, and the third flow path. The first flow path is formed between the inner cylinder and the partition cylinder, the second flow path is formed in a cap-shaped gun tip so as to go around the tip of the partition cylinder, and the third flow path is formed between the outer cylinder and the partition cylinder. In the circumferential direction and the longitudinal direction of the first flow path, the second flow path, and the third flow path, there are no large obstacles that disturb the flow. Therefore, the flow of the coolant does not deviate in a certain direction as in Patent Document 1, so that the gun tip can be cooled without deviation.

  The cylindrical ultrasonic sensor is pressed by the inner cylinder, and allows the coolant to flow from the inside of the inner cylinder through the through hole to the first flow path formed between the inner cylinder and the partition cylinder. That is, the columnar ultrasonic sensor provided under the inner cylinder is always in contact with the coolant flowing through the first flow path, and thus does not receive a temperature change due to hot water as in Patent Document 1. Therefore, the ultrasonic sensor is stable in measurement and is less likely to deteriorate due to thermal shock.

  As described above, according to the first aspect of the present invention, there is provided a spot welding inspection apparatus that can cool the gun tip without unevenness and can realize stabilization of measurement by the ultrasonic sensor and reduction of thermal shock to the ultrasonic sensor. can do.

  In the invention which concerns on Claim 2, the 2nd flow path was comprised by the some groove part notched and formed in the outer peripheral surface of the signal transmission component. Since the coolant always flows in these grooves, the signal transmission component can be sufficiently cooled. Therefore, thermal deformation of the signal transmission component during spot welding work can be prevented.

  In the invention according to claim 3, the signal transmission component is provided on the inner peripheral surface of the gun chip, and has an external thread portion that engages with the screw portion on the outer peripheral surface. Since the degree of adhesion between the signal transmission component and the gun tip is improved, the stability of ultrasonic signal transmission can be improved. According to claim 3, it is possible to provide a spot welding inspection apparatus capable of improving the stability of transmission of ultrasonic signals.

  In the invention which concerns on Claim 4, since the front-end | tip of the shank pressed the rear end of signal transmission components, it can hold down a signal transmission component reliably. According to the fourth aspect of the present invention, it is possible to provide a spot welding inspection apparatus that can reliably hold the signal transmission component.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is an exploded perspective view of a spot welding inspection apparatus according to the present invention. The spot welding inspection apparatus 10 includes an outer cylinder 12, a cap-shaped gun tip 16, a signal transmission component 19, for example, a cylindrical reflective ultrasonic sensor 23. This is an electrode chip with a built-in ultrasonic sensor in which the inner cylinder 26, the partition cylinder 32, the compression coil spring 33, and the pressing cylinder 34 are assembled.

  FIG. 2 is a cross-sectional view of a spot welding inspection apparatus according to the present invention. The spot welding inspection apparatus 10 is an external component of a spot welding gun and a first male thread portion formed on the outer surface of the tip portion with, for example, a taper screw. 11 and a first female thread portion 13 formed by, for example, a taper screw that can be screwed into the first external thread portion 11, are provided on the inner surface of the rear end portion, and a second female thread portion 14 is provided at an intermediate portion of the inner surface. And a cap-shaped gun tip 16 having a heat conduction groove 15 formed downward from the second female screw portion 14 and a convex portion 17 provided at an intermediate portion of the inner surface of the cap-shaped gun tip 16. A resin-made signal transmission component 19 (details will be described later) having a second male screw portion 18 that can be screwed into the second female thread portion 14, and a distal end 22 is formed on the rear end surface 21 of the signal transmission component 19 via an adhesive, for example. A cylindrical reflection-type ultrasonic sensor 23 that is worn, and an intermediate portion that is inserted into the outer cylinder 12 and pressed against the inner surface 24 of the outer cylinder 12 in order to hold down the columnar reflection-type ultrasonic sensor 23. An inner cylinder 26 provided with a plurality of fixing projections 25 (... indicates a plurality; the same applies hereinafter) at the rear end, and a plurality of through holes 27 provided at the tip of the inner cylinder 26 ... (described later in detail), and these through holes 27 ... are inserted into a gap between the cylindrical reflection type ultrasonic sensor 23 and the outer cylinder 12, and the tip 28 reaches the signal transmission component 19. At the same time, the rear end portion 29 is formed of a glass partition tube 32 fitted into a convex portion 31 provided at the front end portion of the inner tube 26.

Further, the spot welding inspection apparatus 10 includes a first flow path 35 formed between the inner cylinder 26 and the partition cylinder 32 from the inside of the inner cylinder 26 through the through holes 27. A second flow path 36 formed in the cap-shaped gun tip 16 so as to go around the tip 28 and a third flow path 37 formed between the outer cylinder 12 and the partition cylinder 32 are provided. For example, cooling water as a coolant can be flowed in the order of the path 35, the second flow path 36, and the third flow path 37.
A cable 38 extends from the cylindrical reflective ultrasonic sensor 23.

In addition, although the 1st external thread part 11 and the 1st internal thread part 13 were formed with the taper screw, since it may be a parallel thread, it does not interfere with changing into the kind of another screw.
In addition, the assembly of the signal transmission component 19 and the cylindrical reflection type ultrasonic sensor 23 uses an adhesive. However, since the contact portion can be screwed, it is not possible to change to another coupling method. There is no problem.

  Referring back to FIG. 1, the signal transmission component 19 has a lower part formed in a columnar shape, and the upper part is divided into three parts and has three support parts 39. A fixing groove 41 is formed on each of the upper surfaces of the three support portions 39..., And the leading end 28 of the partition tube 32 is fitted into the fixing groove 41.

  3 is a cross-sectional view taken along the line 3-3 in FIG. 2, and the inner cylinder 26, the holding cylinder 34, and the cable 38 are inserted into the outer cylinder 12. At this time, the inner cylinder 26 has, for example, three fixing protrusions 25... That protrude from the outer surface of the inner cylinder 26 to the inner surface of the outer cylinder 12. The reflective ultrasonic sensor (reference numeral 23 in FIG. 2) can be stably held down. Thereby, the position shift of a cylindrical reflective ultrasonic sensor can be prevented.

  Although the number of the fixing protrusions 25 has been described as three, it may be changed depending on the outer diameters of the outer cylinder 12 and the inner cylinder 26, and the number is not limited to three.

  Returning to FIG. 2, the same effect can be obtained for the fixing protrusions 25... Provided in the intermediate portion of the inner cylinder 26.

  4 is a cross-sectional view taken along line 4-4 of FIG. 2, and the partition cylinder 32, the inner cylinder 26, and the cable 38 are inserted into the outer cylinder 12. FIG. At this time, the inner cylinder 26 has, for example, three through holes 27 that penetrate through the thickness of the inner cylinder 26. For this reason, when cooling water flows from the diagram direction to the back direction of the inner cylinder 26, the cooling water can be distributed and flowed from the three through holes 27. Thereby, it is possible to prevent the cooling water from flowing in a certain direction.

  In addition, although the number of through-holes 27 ... was demonstrated with three pieces, you may change with the outer diameters of the inner cylinder 26 and the partition cylinder 32, and the number is not limited to three pieces.

  FIG. 5 is a mounting explanatory view of the spot welding inspection apparatus according to the present invention. The spot welding gun 42 is provided on a C-shaped frame 44 attached to the tip of the robot arm 43 and a lower finger portion 45 of the C-shaped frame 44. The fixed side holder 46, the fixed side electrode tip 47 attached to the fixed side holder 46, the cylinder unit 49 provided in the upper finger portion 48 of the C-shaped frame 44, and the movable side holder 52 attached to the cylinder rod 51 of the cylinder unit 49 And the spot welding inspection apparatus 10 attached to the movable side holder 52.

In the figure, the nugget diameter after welding is measured by the spot welding inspection device 10 in a state where the two steel plates 53 and 54 overlapped by the fixed electrode tip 47 and the spot welding inspection device 10 are sandwiched.
Reference numeral 55 denotes a support member for the cylinder unit, and 56 and 56 denote work holders.
Next, the operation of the spot welding inspection apparatus 10 having the above configuration will be described.

  FIG. 6 is an enlarged view of 6 parts in FIG. 5, and after the end of the welding, a nugget 57 is formed on the contact surface between the stacked steel plates 53 and 54. At this time, the cooling water is continuously supplied to the inner cylinder 26 as indicated by arrows, so that the cooling water passes from the inside of the inner cylinder 26 through the through holes 27. It flows in the order of the path 36 and the third flow path 37 and continuously flows out from the outer cylinder 12.

  In this state, when the nugget diameter is measured, an ultrasonic signal is emitted from the cylindrical reflective ultrasonic sensor 23 to the nugget 57 via the signal transmission component 19. This ultrasonic signal is reflected by the reflecting surface provided on the fixed electrode tip 47, and the reflected wave is received by the cylindrical reflective ultrasonic sensor 23. The nugget diameter can be estimated from the obtained reflected wave information.

  During measurement of the nugget diameter, the flow of the cooling water is not biased by the first flow path 35, the second flow path 36, and the third flow path 37. Can be immersed in. Therefore, it is possible to realize stable measurement without causing malfunction during measurement.

  Further, when the cooling water flows through the second flow path 36, it passes through the heat conduction groove 15. The heat conduction groove 15 is formed in an annular shape when viewed in a cross-section obtained by cutting the cap-shaped gun tip 16 in the direction of the front and back of the figure, so that the flow of the cooling water is not biased. Further, since the inner surface of the cap-shaped gun tip 16 is deeply dug, the cold air from the cooling water is easily transmitted to the tip of the cap-shaped gun tip 16. As a result, the two steel plates 53 and 54 can be reliably cooled, which leads to stabilization of the generation of the nugget 57.

  Therefore, the spot welding inspection apparatus 10 is configured to allow the cooling water to flow in the order of the first flow path 35, the second flow path 36, and the third flow path 37. The first flow path 35 is between the inner cylinder 26 and the partition cylinder 32, the second flow path 36 is around the tip 28 of the partition cylinder 32, and the third flow path 37 is between the outer cylinder 12 A large obstruction that disturbs the flow does not exist in the circumferential direction and the longitudinal direction of the first flow path 35, the second flow path 36, and the third flow path 37. Since the cooling water does not flow in a certain direction, the cap-shaped gun tip 16 can be cooled without unevenness.

  Further, the cylindrical reflection type ultrasonic sensor 23 is pressed by the inner cylinder 26, and the cooling water is formed between the inner cylinder 26 and the partition cylinder 32 from the inside of the inner cylinder 26 through the through holes 27. The first flow path 35 flows. In other words, the columnar reflection type ultrasonic sensor 23 provided under the inner cylinder 26 is always in contact with the cooling water flowing through the first flow path 35, and therefore does not receive a temperature change due to the hot water. Therefore, the cylindrical reflective ultrasonic sensor 23 is stable in measurement and is less likely to be deteriorated by a thermal shock.

From the above, the spot welding inspection apparatus 10 can cool the cap-shaped gun tip 16 without deviation, stabilize the measurement with the cylindrical reflective ultrasonic sensor 23, and reduce the thermal shock to the ultrasonic sensor 23. Can be realized.
Next, an embodiment in which the material of the signal transmission component 19 incorporated in the cap-shaped gun chip 16 is changed will be described.

FIG. 7 is a diagram showing a modified embodiment of FIG. 2, and the same components as those in FIG.
The spot welding inspection apparatus 10B is characterized in that a flat surface 58 is provided on the inner surface of a cap-shaped gun tip 16B, and a copper signal transmission component 19B is placed on the flat surface 58. Since the signal transmission component 19B is made of copper, it is easy to transmit the cooling air to the cap-shaped gun chip 16B.

  Further, since the cap-shaped gun tip 16B is provided with the flat surface 58, it is not necessary to perform groove processing as compared with the cap-shaped gun tip 16 described above. For this reason, the processing cost can be reduced, which contributes to a reduction in the price of the spot welding inspection apparatus 10B.

FIG. 8 is an enlarged view of the cap-shaped gun tip shown in FIG. 7, and the same reference numerals are used for the same components as those in FIG.
The copper signal transmission component 19B includes a second male screw portion 18B that engages with a second female screw portion 14B provided on the inner peripheral surface of the cap-shaped gun chip 16B on the outer peripheral surface.

  Therefore, since the degree of adhesion between the signal transmission component 19B and the gun tip 16B is improved, it is possible to provide the spot welding inspection apparatus 10B that can improve the stability of ultrasonic signal transmission.

  Further, the signal transmission component 19B has a rear end surface 21B formed in a flat shape and a front end surface 59 attached so as to be in contact with the flat surface 58 of the cap-shaped gun chip 16B. Transmission of the transmitted ultrasonic signal is not hindered.

  61 is an annular flow path provided in the inner bottom of the cap-shaped guntip, 62 is a cylindrical portion of the signal transmission component, and 63 is an outer peripheral surface of the cylindrical portion.

  FIG. 9 is a cross-sectional view taken along line 9-9 in FIG. 8, and the second flow path 36B is formed outside the inner peripheral surface 64 of the cap-shaped gun tip 16B and the cylindrical portion (reference numeral 62 in FIG. 8) of the signal transmission component 19B. For example, three groove portions 65, 65, 65 formed by three support portions 39B, 39B, 39B protruding in the direction and the outer peripheral surface of the cylindrical portion (reference numeral 63 in FIG. 8), and the support portions 39B, 39B, 39B It is comprised with the annular flow path (FIG. 8 code | symbol 61) formed in the figure back direction.

  That is, the second flow path 36B has, for example, three groove portions formed by notching the outer peripheral surface 66 of the signal transmission component 19B with the outer peripheral surface of the support portions 39B, 39B, 39B as the outer peripheral surface 66 of the signal transmission component 19B. It is characterized by comprising 65, 65, 65.

  Although the number of the groove portions 65 is three in the above description, the number is arbitrary, and the number is not limited to three.

  Since the coolant always flows in the grooves 65, 65, 65, the signal transmission component 19B can be sufficiently cooled. Therefore, thermal deformation of the signal transmission component 19B during the spot welding operation can be prevented.

  Moreover, since the front-end | tip (FIG. 8 code | symbol 28) of the partition cylinder 32 fits in the fixing grooves 41, 41, 41 of the support parts 39B, 39B, 39B provided in the upper part of the signal transmission component 19B, the coolant flows. Sometimes, it is possible to prevent the partition tube 32 from shifting in the vertical and horizontal directions.

  In the spot welding inspection apparatuses 10 and 10B described so far, the signal transmission parts 19 and 19B are coupled to the gun tips 16 and 16B with screws, but the signal transmission parts can be fixed to the gun chip without using screw coupling. Examples will now be described.

  FIG. 10 is a cross-sectional view of another spot welding inspection apparatus according to the present invention, and the same components as those in FIG. In this example, the name of the outer cylinder of the spot welding inspection apparatus 10 or 10B described above is changed to a shank. The main change is that the signal transmission component is held by the tip of the shank.

  The spot welding inspection device 70 is formed on the inner periphery so as to be engaged with the tapered portion 71 of the shank 72 and the cylindrical shank 72 formed in a tapered shape such that the tip portion is a tapered portion 71, for example. For example, a circular gun tip 74 provided with, for example, a tapered portion 73 as an engaged portion, and a plurality of projecting members 77 (described later in detail) that transmit ultrasonic signals and are provided at the lower end portion. For example, a cylindrical reflection type ultrasonic sensor 78, and a front end surface 85 as a front end, which is built in the gun chip 74 and is in contact with a flat surface 86 provided on the inner bottom portion of the gun chip 74, as a rear end surface. For example, a circular signal transmission component 75 in which 76 abuts on the reflective ultrasonic sensor 78, and a second flow path 79 formed in the gun chip 74 so as to go around the distal end 28 of the partition tube 32. The tip 81 of the tapered portion 71 of the shank 72 includes a contact surface 82 that contacts the rear end surface 76 as the rear end of the signal transmission component 75, and the signal transmission component 75 is pressed by the contact surface 82. Yes.

  The method for connecting the shank 72 and the gun tip 74 has been described above by fitting the taper portion 73 provided on the gun tip 74 to the taper portion 71 provided on the shank 72. However, the shank 72 and the gun tip 74 are connected by screws. However, it is possible to change to another coupling method.

  Further, the shank 72, the gun chip 74, the reflective ultrasonic sensor 78, and the signal transmission component 75 have been described as being formed into a cylindrical shape, a circular shape, a circular shape, or a circular shape in a cross-sectional view in the above. Since each can be formed into a square pipe shape, a square columnar shape, or a square shape in a cross-sectional view, it can be changed to other shapes.

  83 is a circumferential mounting seat, 87 is an annular flow path provided in the inner bottom of the cap-shaped guntip, 88 is a cylindrical portion of the signal transmission component, and 89 is an outer peripheral surface of the cylindrical portion.

  In the spot welding inspection device 70, the contact surface 82 provided at the tip 81 of the shank 72 presses the rear end surface 76 as the rear end of the signal transmission component 75, so that the signal transmission component 75 is securely pressed. be able to.

  11 is a cross-sectional view taken along the line 11-11 in FIG. 10, and the second flow path 79 protrudes radially outward from the inner peripheral surface 91 of the gun tip 74 and the cylindrical portion (reference numeral 88 in FIG. 10) of the signal transmission component 75. For example, the three support portions 92, 92, 92 and the outer peripheral surface of the cylindrical portion (reference numeral 89 in FIG. 10), for example, the three groove portions 93, 93, 93 and the back of the support portions 92, 92, 92 are illustrated. It is comprised with the annular flow path (FIG. 10 code | symbol 87) formed in a direction.

  That is, the second flow path 79 has three groove portions 93 formed by notching the outer peripheral surface 94 of the signal transmission component 75 with the outer peripheral surfaces of the support portions 92, 92, 92 as the outer peripheral surface 94 of the signal transmission component 75. , 93, 93.

Although the number of the support portions 92 is three in the above description, since the number is arbitrary, the number of the support portions 92 is not limited to three.
In addition, the number of the groove portions 93 is three in the above, but the number is arbitrary, and thus the number of the groove portions 93 is not limited to three.

  Since the coolant always flows in the grooves 93, 93, 93, the signal transmission component 75 can be sufficiently cooled.

  Further, for example, three projecting members 77, 77, 77 are attached to the cylindrical reflective ultrasonic sensor 78 so as to contact the inner peripheral surface 95 of the partition tube 32, so that the coolant is flowing. In addition, the partition tube 32 can be prevented from shifting in the vertical and horizontal directions.

  FIG. 12 is a diagram showing a modified embodiment of FIG. 10, and the same components as those in FIG. The main change is that the material of the signal transmission component is changed from copper to resin.

  In the spot welding inspection apparatus 70B, for example, a circular gun tip 74B in a cross-sectional view includes, for example, a circumferential mounting seat 83B on the inner peripheral surface, and the circumferential mounting seat 83B has, for example, a circular shape. The formed resin signal transmission component 75B is fitted. 92B is a support part.

  The shank 72, the gun chip 74B, the mounting seat 83B, the reflective ultrasonic sensor 78, and the signal transmission component 75B are each formed in a cylindrical shape, a circular shape, a circumferential shape, a cylindrical shape, and a circular shape in a cross-sectional view. However, each of them can be formed into a square pipe shape, a square shape, a circumferential shape, a prism shape, or a square shape in a cross-sectional view, so that it can be changed to other shapes.

  Since the coolant flows in the order of the first flow path 35, the second flow path 79, the heat conduction groove 96, and the third flow path 37, the coolant always contacts the signal transmission component 75B. Therefore, the signal transmission component 75B can be prevented from being deformed by welding heat.

  In the spot welding inspection apparatuses 70 and 70B described above, the signal transmission parts 75 and 75B are pressed by the contact surface of the tip of the shank. In addition to this, when the signal transmission component and the gun tip are coupled with screws, the signal transmission component and the gun tip are more firmly fixed. Next, an embodiment in which the signal transmission component is held by the contact surface of the tip of the shank and the signal transmission component and the gun tip are coupled with a screw will be described.

  FIG. 13 is a diagram showing a modified embodiment of FIG. 12. The same reference numerals are used for the same components as those in FIG. The main change is that the mounting method of the signal transmission component to the gun tip is changed from press fitting to screw coupling.

  The spot welding inspection apparatus 70C is provided on the outer peripheral surface of the circular signal transmission component 75C made of resin, for example, on the second female screw portion 97 provided on the inner peripheral surface of the circular gun tip 74C in a cross-sectional view. The second male screw portion 98 is screwed to attach the signal transmission component 75C to the gun chip 74C. 92C is a support part, and 96C is a groove for heat conduction.

  The shank 72, the gun chip 74C, and the reflection type ultrasonic sensor 78 are each formed in a cylindrical shape and a circular shape and a cylindrical shape in a cross-sectional view. Since it can be formed in a square shape or a prismatic shape, it can be changed to another shape.

  In the spot welding inspection apparatus 70C, the degree of adhesion between the signal transmission component 75C and the gun tip 74C is improved, so that the stability of transmission of ultrasonic signals can be improved.

  FIG. 14 is a diagram showing a further modified embodiment of FIG. 10, and the same reference numerals are used for the same components as those in FIG. The main change is the same as in FIG. 13, and the mounting method of the signal transmission component to the gun tip is changed from press-fitting to screw connection.

  The spot welding inspection device 70D has a second female thread portion 97D provided on the inner peripheral surface of a circular gun tip 74D, for example, in a cross-sectional view, and is made of copper and provided on the outer peripheral surface of a circular signal transmission component 75D. Two male screw portions 98D are screwed in, and the signal transmission component 75D is attached to the gun chip 74D. 92D is a support part.

  The shank 72, the gun chip 74D, and the reflective ultrasonic sensor 78 are each formed in a cylindrical shape and a circular shape and a cylindrical shape in a cross-sectional view. Since it can be formed in a square shape or a prismatic shape, it can be changed to another shape.

  In the spot welding inspection apparatus 70D, the degree of adhesion between the signal transmission component 75D and the gun chip 74D is improved, so that the stability of transmission of ultrasonic signals can be improved.

Although the columnar ultrasonic sensor used in the spot welding inspection apparatus of the present invention has been described as a reflection type in the embodiment, it can be changed to another type because a transmission type can be adopted. .
Moreover, although the coolant used in the spot welding inspection apparatus of the present invention employs cooling water in the embodiment, it can be applied as long as it is a nonflammable gas or liquid, and therefore other cooling media may be applied. .

  In the embodiment, the coupling method of the outer cylinder and the cap-shaped gun tip used in claim 1 has been described as the screw coupling. For example, the protruding member provided in the axial direction on the outer surface of the outer cylinder and the cap-shaped gun chip are connected. By fitting the groove portion provided in the axial direction on the inner surface, the outer cylinder and the cap-shaped gun tip can be coupled, so that it is possible to change to another coupling method.

  Furthermore, in the embodiment, the signal transmission component used in claim 1 has been described by being coupled to the cap-shaped gun tip with a screw. However, it is possible to press-fit a signal transmission component that is not threaded into the cap-shaped gun chip. Since it can be adopted, it can be changed to other coupling methods.

  The spot welding inspection apparatus of the present invention is suitable for an automobile body production line that performs welding and inspection at high speed.

It is a disassembled perspective view of the spot welding inspection apparatus which concerns on this invention. It is sectional drawing of the spot welding inspection apparatus which concerns on this invention. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. It is attachment explanatory drawing of the spot welding inspection apparatus which concerns on this invention. FIG. 6 is an enlarged view of 6 parts in FIG. 5. FIG. 3 is a modified embodiment diagram of FIG. 2. It is an enlarged view of the cap-shaped guntip shown in FIG. FIG. 9 is a sectional view taken along line 9-9 in FIG. 8. It is sectional drawing of another spot welding inspection apparatus which concerns on this invention. It is the 11-11 line sectional view of FIG. FIG. 11 is a modified embodiment diagram of FIG. 10. FIG. 13 is a modified example of FIG. 12. FIG. 11 is a further modified embodiment of FIG. 10. It is a figure explaining the basic composition of the conventional technology.

Explanation of symbols

  10, 10B, 70, 70B, 70C, 70D ... Spot welding inspection device, 12 ... Outer cylinder, 14, 14B, 97, 97B ... Second female thread (female thread), 16, 16B ... Cap-shaped gun tip, 18, 18B, 98, 98B ... 2nd male thread part (male thread part), 19, 19B, 75, 75B, 75C, 75D ... Signal transmission component, 23 ... Cylindrical reflective ultrasonic sensor (cylindrical super Sonic sensor), 26 ... inner cylinder, 27 ... through hole, 28 ... tip of partition cylinder, 32 ... partition cylinder, 35 ... first flow path, 36, 36B, 79 ... second flow path, 37 ... third flow path , 39, 39B, 92, 92B, 92C, 92D ... support portion, 42 ... spot welding gun, 57 ... nugget (welded portion), 58,86 ... plane, 59,85 ... tip surface of signal transmission component, 64,91 ... Gun tip inner peripheral surface, 65, 93 ... groove, 6, 94 ... outer peripheral surface of signal transmission component, 71 ... tapered portion, 72 ... cylindrical shank (shank), 73 ... tapered portion, 74, 74B, 74C, 74D ... circular guntip (guntip), 76 ... signal Rear end surface of transmission part (rear end of signal transmission part), 78 ... Cylindrical reflective ultrasonic sensor (ultrasonic sensor), 81 ... Tip of shank taper (tip of shank), 82 ... Contact surface, 83, 83B ... Circumferential mounting seats.

Claims (4)

In the spot welding inspection apparatus in which an ultrasonic sensor is built in a spot welding gun and a weld formed by the spot welding gun can be inspected by the ultrasonic sensor,
The spot welding inspection apparatus includes an outer cylinder that is an external component of a spot welding gun, a cap-shaped gun tip that is fitted to one end of the outer cylinder, a signal transmission component that is incorporated in the gun chip and transmits a signal, The cylindrical ultrasonic sensor whose one end is in close contact with the signal transmission component, an inner cylinder inserted into the outer cylinder in order to hold down the cylindrical ultrasonic sensor, and a penetration provided in a lower portion of the inner cylinder A hole, a partition cylinder that surrounds the through-hole and is inserted into a gap between the cylindrical ultrasonic sensor and the outer cylinder, and a tip of which reaches the signal transmission component; and the through-hole from the inside of the inner cylinder A first flow path formed between the inner cylinder and the partition cylinder, a second flow path formed in the gun tip so as to go around a tip of the partition cylinder, the outer cylinder, and the Formed between partition tube And a third flow path that,
A spot welding inspection apparatus configured to allow a coolant to flow in the order of the first flow path, the second flow path, and the third flow path.   The spot welding inspection apparatus according to claim 1, wherein the second flow path is configured by a plurality of grooves formed in the outer peripheral surface of the signal transmission component. In the spot welding inspection apparatus in which an ultrasonic sensor is built in a spot welding gun and a weld formed by the spot welding gun can be inspected by the ultrasonic sensor,
The spot welding inspection apparatus includes a gun tip that abuts on a workpiece, the ultrasonic sensor that transmits an ultrasonic signal to the workpiece, a built-in gun tip, a tip that abuts on the gun tip, and a rear end that is the ultrasonic sensor. And a signal transmission component that abuts
The said signal transmission component is provided with the external thread surface which engages with a thread part in order to provide in the internal peripheral surface of the said gun chip, The spot welding inspection apparatus characterized by the above-mentioned. In the spot welding inspection apparatus in which an ultrasonic sensor is built in a spot welding gun and a weld formed by the spot welding gun can be inspected by the ultrasonic sensor,
The spot welding inspection apparatus includes a shank, a gun tip that is engaged with the tip of the shank and abuts against the workpiece, the ultrasonic sensor that transmits an ultrasonic signal to the workpiece, the gun tip, and a tip that is incorporated in the gun tip. A signal transmission component that abuts against the gun chip and a rear end abuts against the ultrasonic sensor;
The spot welding inspection apparatus, wherein a tip of the shank presses a rear end of the signal transmission component.

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