JP2020069528A - Electric resistance weld electrode and component detection method - Google Patents

Abstract

To detect presence/absence of a shaft-shaped component before advancing an electrode and secure a sure detection operation.SOLUTION: A shaft-shaped component 1 comprising a shaft part 2, a flange 3, and a protrusion 4 for deposition is an object of electric resistance weld. A guide cylinder 10 formed of an insulation material is inserted into a cylindrical electrode body 5, a reception hole 17 into which the shaft part 2 is inserted is formed on a lid member 15 of the electrode body 5, an insulation cylinder 18 is formed on the reception hole 17, a stopper member 23 which is formed of a container 25 storing a magnet 24 and a guide part 26 for acting magnet suction force to the shaft-shaped component 1 is inserted into an open hole 12 of the guide cylinder 10 in a slidable manner. An insulation gap C is formed between the flange 3 and an end surface 29 of the lid member 15, a compression coil spring 36 is provided between a washer 33 arranged on the electrode body 5 and the stopper member 23, detection conductors 34, 35 are connected to the washer 33 and the electrode body 5, tensile force of the compression coil spring 36 is set to become smaller than insertion compression force when the shaft part 2 is inserted into the reception hole 17.SELECTED DRAWING: Figure 1

Description

  The present invention provides an electric resistance welding electrode and a component for accurately and efficiently detecting the presence or absence of a shaft-shaped component when supplying a shaft-shaped component such as a projection bolt having a shaft portion, a flange and a welding projection to an electrode. It relates to the detection method.

  International Publication No. WO2004 / 009280 describes that whether or not a shaft-shaped component is inserted into a receiving hole of an electrode is detected when the electrode advances and pressurizes a steel plate component.

International publication number WO2004 / 009280

  In the technique described in Patent Document 1, it is detected whether or not the shaft-shaped component is inserted into the receiving hole of the electrode when the electrode advances and pressurizes the steel plate component. When the shaft-shaped component is normally inserted in the electrode, the shaft-shaped component is pressed against the steel plate component and a welding current is applied, so there is no particular problem. However, if the shaft-shaped part is not inserted into the electrode for some reason, the electrode will make a stroke for advancing toward the steel plate part in the absence of the shaft-shaped part. You will have an empty stroke. Then, the electrode must be returned to its original position and the shaft-shaped component must be inserted again. Such an operation is a wasteful operation and needs improvement in terms of efficiency.

  The present invention is provided to solve the above problems, and an electric resistance welding electrode and a component that can detect the presence or absence of a shaft-shaped component before the electrode advances and can secure a reliable detection operation. The purpose is to provide a detection method.

The invention according to claim 1 relates to an electric resistance welding electrode,
A shaft part, a flange integrated with the shaft part, and a shaft-shaped part having a welding projection on a flange surface opposite to the shaft part are subjected to electric resistance welding,
A guide tube made of an insulating material is inserted into the metal electrode body, which has a cylindrical shape.
The lid member fixed to the end portion of the electrode body is formed with a receiving hole into which the shaft portion of the shaft-shaped component is inserted,
An insulating cylinder for insulating the inner surface of the receiving hole and the shaft portion is provided in the receiving hole,
In the through hole provided in the guide cylinder, a stopper member consisting of a container for housing a magnet and a guide portion for applying a magnet attraction force to the shaft-shaped component is slidably inserted,
The through hole and the receiving hole are arranged coaxially so that the end portion of the shaft portion inserted into the receiving hole hits the guide portion,
The length of the receiving hole is set so that an insulating gap is formed between the flange of the shaft-shaped component inserted in the receiving hole and the end surface of the lid member,
A compression coil spring for setting the standby position of the stopper member is provided between the washer arranged in the concave hole of the electrode body and the stopper member,
A detection lead wire is connected to the washer and the electrode body,
The tension of the compression coil spring is set to be smaller than the insertion pressing force when the shaft portion is inserted into the receiving hole.

  The shaft part of the shaft-shaped part that has been transferred by advancing such as the supply rod stops at the position where it is coaxial with the receiving hole of the lid member, and then the shaft part is inserted into the receiving hole and the end part of the shaft part Collides with the guide portion of the stopper member, and the shaft portion is attracted to the guide portion by the attraction force of the magnet that acts on the shaft portion through the guide portion, and becomes stationary. When in this stationary state, an insulating gap is formed between the flange of the shaft-shaped component and the end surface of the lid member. The sensing conductor, the washer, the compression coil spring, the stopper member, and the shaft-shaped component are in a conductive state, but an insulating gap is formed between the flange of the shaft-shaped component and the end surface of the lid member. Therefore, the detection current does not flow to the lid member.

  When the insertion pressure force such as air injection acts on the shaft-shaped part that forms the insulation gap, the tension of the compression coil spring is set to be smaller than the insertion pressure force. The member is retracted, the insulating gap disappears, and conductive contact is established between the flange and the end surface of the lid member. Due to the disappearance of this insulating gap, a detection current flows from the lid member to the other detection lead wire through the electrode body. Since there is an insulating gap between the shaft-shaped part and the shaft-shaped part in the current path of the detection current, the shaft to the receiving hole is fed when the shaft-shaped part is supplied to the electrode, that is, before the electrode advances toward the steel plate part. The normal insertion of the strip-shaped parts can be detected. Such detection energization is interrupted only by opening and closing the insulating gap, because the receiving hole is provided with the insulating cylinder that insulates the inner surface of the receiving hole from the shaft portion.

  By making the insulation gap a minute gap, the insertion pressure applied to the shaft-shaped component will ensure that the insulation gap disappears, and the conduction from the flange to the lid member will be ensured, resulting in highly reliable component detection. Is possible. Even if minute impurities are present between the insulating gaps, the pressing force of the flange with respect to the end surface of the lid member can be increased, so that the electrical continuity between the two due to the elimination of the insulating gaps can be surely obtained.

  The insulating gap is formed after the shaft portion is inserted into the receiving hole. After that, since the insulating gap which is made a narrow space is erased, this erase is surely performed. Since the insulating gap is a narrow gap, the presence of a component can be detected by momentarily closing this gap as if it were a pulse signal. Therefore, highly accurate and highly reliable detection can be obtained with a momentary signal that is reliably transmitted.

  When the shaft-shaped part is not inserted into the receiving hole for some reason, the shaft-shaped part does not function as a conduction mediating member, so that the detection current is not passed from one detection conducting wire to the other detection conducting wire. The absence of the strip-shaped component is detected before the advance of the electrode. As a method for detecting the absence of parts, for example, air injection or push rod projection to obtain the insertion pressure is performed, and even if a predetermined time has elapsed from that point, one detection lead wire to the other detection lead wire. When the detection current is not energized, the absence of the energization is used as a trigger to detect the absence of the shaft-shaped component.

  Since the insulating cylinder that insulates the inner surface of the receiving hole from the shaft portion is provided in the receiving hole, the passage of the detection current is interrupted only by opening and closing the insulating gap, and the detection structure can be simplified.

  By setting the insertion pressure for eliminating the insulating gap to a predetermined value or more, the flange can be pressed strongly against the end surface of the lid member, and the conductivity between the flange and the lid member can be ensured. Therefore, a good detection operation can be secured.

  Since the momentary energization time for determining the existence of parts is sufficient for closing the insulation gap and enabling energization, so when the insertion pressure is required for the blast air, the blast of the blast air is made to be a momentary blast. Therefore, it is possible to reduce the amount of injected air and pursue economic efficiency. In addition, since the insulating gap is regenerated by the tension of the compression coil spring after the presence of the component is detected, unnecessary energization and simplification of the control circuit related thereto can be achieved.

The invention according to claim 2 relates to a method for detecting a component in an electric resistance welding electrode,
A shaft part, a flange integrated with the shaft part, and a shaft-shaped part having a welding projection on a flange surface opposite to the shaft part are subjected to electric resistance welding,
A guide tube made of an insulating material is inserted into the metal electrode body, which has a cylindrical shape.
The lid member fixed to the end portion of the electrode body is formed with a receiving hole into which the shaft portion of the shaft-shaped component is inserted,
An insulating cylinder for insulating the inner surface of the receiving hole and the shaft portion is provided in the receiving hole,
In the through hole provided in the guide cylinder, a stopper member consisting of a container for housing a magnet and a guide portion for applying a magnet attraction force to the shaft-shaped component is slidably inserted,
The through hole and the receiving hole are arranged coaxially so that the end portion of the shaft portion inserted into the receiving hole hits the guide portion,
The length of the receiving hole is set so that an insulating gap is formed between the flange of the shaft-shaped component inserted in the receiving hole and the end surface of the lid member,
A compression coil spring for setting the standby position of the stopper member is provided between the washer arranged in the concave hole of the electrode body and the stopper member,
A detection lead wire is connected to the washer and the electrode body,
Prepare an electric resistance welding electrode in which the tension of the compression coil spring is set to be smaller than the insertion pressure when the shaft portion is inserted into the receiving hole,
It is characterized in that the stopper member is retracted while the compression coil spring is contracted by the insertion pressing force to establish conductive contact between the flange and the end surface of the lid member.

  The effect of the invention of this component detection method is the same as the effect of the invention of the electric resistance welding electrode described above.

It is sectional drawing of an electrode. It is sectional drawing which shows another supply mechanism. It is a control system diagram.

  Next, modes for carrying out the electric resistance welding electrode and the component detection method of the present invention will be described.

  1 to 3 show Embodiment 1 of the present invention.

  First, the shaft-shaped component will be described.

  The shaft-shaped component 1 is made of iron, and is a projection bolt 1 in this case. The shaft part 2 has a male thread, a flange 3 integrated with the shaft part 2, and a flange surface on the opposite side of the shaft part 2. Has a protrusion 4 for welding. The welding projection 4 is formed on the flange surface on the side opposite to the shaft-shaped component 2 by a circular tapered projection having a peak at the center. The welding projection may be a plurality of wart-shaped projections. Here, the length of the shaft portion 2 is 21 mm, the diameter of the flange is 14 mm, and the diameter of the welding projection is 9.5 mm.

  Next, the overall structure of the electric resistance welding electrode will be described.

  The electrode body 5 is made of a conductive metal material such as chrome copper, and has a circular cross section and a tubular shape. The electrode body 5 is a movable electrode, and is moved forward / backward by a forward / backward drive means such as an air cylinder 56 (see FIG. 3).

  The electrode body 5 is configured by integrating a cylindrical base member 7 that is joined to the joining member 6 and a cylindrical connecting tube 8 with a screw portion 9. A guide cylinder 10 made of a synthetic resin insulating material is fitted in the electrode body 5. The guide cylinder 10 is provided with a through hole 12, which is composed of a large diameter hole 13 and a small diameter hole 14, and both holes 13 and 14 are arranged coaxially with the electrode axis OO. The guide tube 10 may be made of any material having excellent heat resistance, insulation and abrasion resistance, and polytetrafluoroethylene (trade name: Teflon.RTM.) Is preferably used. As another material, it is also possible to adopt a synthetic resin having excellent heat resistance, insulation properties and abrasion resistance from the polyamide resins.

  A lid member 15 formed by machining a thick copper alloy block material at the end of the electrode body 5 is integrated with the connecting cylinder 8 via a screw portion 16. A receiving hole 17 into which the shaft portion 2 is inserted is opened in the lid member 15, and an insulating cylinder 18 that insulates the inner surface of the receiving hole 17 from the shaft portion 2 is provided in the receiving hole 17. That is, since the inner surface of the receiving hole 17 is insulated, the inner surface of the insulating cylinder 18 is the inner surface of the receiving hole 17. As shown in FIG. 1 (A), a taper hole 19 having a large diameter in the downward direction is continuously provided below the receiving hole 17, so that the gap of the taper portion 19 prevents conductivity. ing.

  This electrode is water-cooled, and an annular cooling passage 20 is formed in the guide cylinder 10 in the circumferential direction, and the cooling water entering from the inlet pipe 21 passes through the cooling passage 20 and exits from the outlet pipe 22 for welding. Cool the heat.

  Reference numeral 52 is a steel plate component to which the projection bolt 1 is welded, and reference numeral 53 is a fixed electrode on which the steel plate component 52 is placed.

  Next, the stopper member will be described.

  The stopper member 23 has a circular cross-section, and a container 25 that houses a magnet (permanent magnet) 24 is welded to a guide portion 26 that applies the attraction force of the magnet 24 to the shaft portion 2. The guide portion 26 has a smaller diameter than the container 25 and is slidably inserted into the small diameter hole 14, and the container 25 is slidably inserted into the large diameter hole 13. The guide portion 26 is made of iron, and the magnet 24 is in close contact with the shaft portion 2 to exert a stronger attractive magnetic force.

  The through hole 12 and the receiving hole 17 are coaxial with each other so that the end of the shaft portion 2 inserted in the receiving hole 17 abuts against the flat lower end surface 27 of the guide portion 26. That is, the small diameter holes 14 and the receiving holes 17 are arranged on the electrode axis O-O, and the small diameter holes 14 and the receiving holes 17 are in communication with each other.

  Next, the insulating gap will be described.

  The flat flange surface 28 on the opposite side to the welding projection 4 and the flat end surface 29 of the lid member 15 are present on an imaginary plane where the electrode axes OO arranged in the vertical direction intersect perpendicularly. An insulating gap C is formed between the flange surface 28 and the end surface 29 of the lid member 15. The insulating gap C is set by adjusting the length of the receiving hole 17 of the lid member 15. The insulating gap C here is 0.4 mm. When the thickness is 0.4 mm, the insulating gap C is immediately erased by the insertion pressure, the response time is saved, and impurities such as iron scraps are less likely to enter. Such an advantage can be expected from 0.4 mm to 1 mm, but if it is less than 0.4 mm, conductive impurities adhering to the end surface 29 are caught and the bolt is arbitrarily bolted before the insertion pressure is applied. The presence signal is emitted and normal sequence operation cannot be maintained. If it exceeds 1 mm, impurities such as iron scraps and spatters may enter the insulating gap C and cause erroneous conduction.

  Next, the compression coil spring will be described.

  A recess 31 communicating with the through hole 12 is formed in the central portion of the base member 7 of the electrode body 5, and an insulating cup 32 made of an insulating material is pushed into the recess 31. A copper plate or the like is inserted into the insulating cup 32. The circular flat plate washer 33 thus formed is fitted. A detection conductor 34 is connected to the washer 33, and the other detection conductor 35 is connected to the outer surface of the electrode body 5.

  The compression coil spring 36 is inserted between the washer 33 and the stopper member 23 to set the standby stop position of the stopper member 23. As shown in FIG. 1C, a stationary end surface 37 is formed at the boundary between the large diameter hole 13 and the small diameter hole 14, and a movable end surface 38 is formed at the boundary between the container 25 and the guide portion 26. Both end faces 37, 38 are present on a virtual plane where the electrode axis lines OO intersect in a straight line.

  The movable end surface 38 of the stopper member 23 is pressed against the stationary end surface 37 of the guide cylinder 10 by the tension of the compression coil spring 36, and the standby stop position of the stopper member 23 is set.

  Next, the supply mechanism of the shaft-shaped component will be described.

  The supply mechanism may be a structure for inserting the shaft-shaped component 1 into the receiving hole 17 from another location, and may be a supply rod that moves forward and backward in the horizontal direction and the vertical direction, or a supply rod that moves forward and backward in the diagonal direction and the vertical direction. Various other types can be adopted.

  Here, it is of a system in which the forward / backward movement in the horizontal direction and the forward / backward movement in the vertical direction are combined, and is shown in FIG. 1 (A). In the supply mechanism 40, the supply rod 41 moves forward and backward in the horizontal direction indicated by the arrow 42 and in the vertical direction indicated by the arrow 43, and the socket member 44 is welded to the tip of the supply rod 41. The socket member 44 is provided with a two-step type concave hole 45 for receiving the flange 3 and the welding projection 4. An air injection port 46 is opened at the bottom surface of the center of the recessed hole 45. The air injection port 46 is connected to the air control valve 100 (see FIG. 3) via an air pipe 47, and high pressure air is injected from the air injection port 46. Further, a permanent magnet 48 for preventing the shaft-shaped component 1 from shaking is embedded in the socket member 44. The horizontal and vertical operations are performed by the air cylinders 49 and 50 shown in FIG.

  Next, another supply mechanism will be described.

  FIG. 2 shows another supply mechanism. In the supply mechanism 40 shown in FIG. 1, the vertical movement is performed by the raising operation of the supply rod 41 itself, but in the one shown in FIG. 2, this raising operation is performed by the elevating air cylinder 54. An elevating air cylinder 54 is fixed to the lower side of the supply rod, and the piston rod 55 moves the socket member 44 up and down. The rest of the configuration is the same as that of the example of FIG. 1 including parts not shown, and the members having the same functions are designated by the same reference numerals.

  Next, the energization path will be described.

  Although the detection current from the detection lead wire 34 can energize the washer 33, the compression coil spring 36, the stopper member 23, and the shaft-shaped component 1, since there is an insulating gap C, the lid member 15 and the electrode body 5 are provided. The other detection lead wire 35 is not energized. When the flange 3 comes into close contact with the end surface 29 of the lid member 15, the energizing circuit from the detection conductor 34 to the washer 33, the compression coil spring 36, the stopper member 23, the shaft-shaped component 1, the lid member 15, the electrode body 5, and the detection conductor 35. Is established and the existence of parts is confirmed before the advance of the electrode. In the above configuration, the detection lead wire 34 is on the positive side, but it may be on the negative side.

  Next, the insertion pressure will be described.

  The insertion pressure is obtained by air injection from the air injection port 46. The supply rod 41 moves in the horizontal direction and stops at the position where the shaft portion 2 is coaxial with the receiving hole 17. Then, when the supply rod 41 moves up in the vertical direction and the tip of the shaft portion 2 enters the receiving hole 17 over a length of 4 to 5 mm, the rising is stopped. Simultaneously with this stop, air is jetted from the air jet port 46, the tip of the shaft portion 2 strikes the lower end surface 27 of the guide portion 26, and an insulating gap C is formed. By continuing the air injection following the formation of the insulating gap C, the flange 3 is pressed against the end surface 29 of the lid member 15 and the insulating gap C disappears.

  The insertion pressure force by air injection is secured as described above. Therefore, the tension of the compression coil spring 36 is set smaller than the insertion pressure. Since the magnitude relationship between the tension of the compression coil spring 36 and the insertion pressure is set in this manner, the flange 3 can be reliably brought into close contact with the end surface 29 of the lid member 15.

  When the projection bolt 1 is normally supplied, the pressurization of the insertion pressurizing force is temporarily stopped at the stage when the insulating gap C is formed, and then the pressurized air is re-injected, Although not provided, it is possible to detect the presence of a component before the advance of the electrode by ejecting the push rod to erase the insulating gap C.

  Next, a case where the shaft-shaped component is not supplied will be described.

  If the shaft-shaped component 1 is not inserted into the receiving hole 17 for some reason, the detection current from the detection conductor wire 34 can pass to the guide portion 26, but the shaft-shaped component 1 does not exist. Therefore, it is impossible to energize the lid member 15 side. The detection of the non-energization uses the signal obtained from the supply mechanism 40, that is, the transmission of the injection start signal for injecting the air from the air injection port 46. The absence of parts is detected under the AND condition that a predetermined time has elapsed from the transmission of the injection start signal and that the detection lead wire 34 is not energized. Reference numeral 51 is a detection device in which the detection lead wires 34 and 35 are connected.

  Instead of the AND condition, the trigger may be triggered only when a predetermined time has elapsed from the transmission of the injection start signal.

  Next, the control system will be described.

  The above-described operation of advancing and retracting the supply rod, air injection, and the like can be easily performed by a generally adopted control method. By combining an air switching valve that operates with a signal from a control device composed of a simple computer device, a sensor that emits a signal at a predetermined position of an air cylinder, and sends a signal to the control device, a predetermined operation can be performed. Can be secured.

  FIG. 3 shows an example of the control system. In the figure, arrows indicate signal transmission lines, and the rest are air pipes that mainly supply and discharge operating air. The air switching valve 100 operates in response to a signal from the control device 200 to supply and discharge working air to each air cylinder and socket member. In FIG. 3, the shaft-shaped component 1 is held by the socket member 44, the air cylinder 49 advances in response to a command signal from the control device 200, and the projection bolt 1 is stopped coaxially with the electrode axis OO. Indicates the state. Then, the command signal from the control device 200 causes the piston rod of the air cylinder 50 to rise, and stops when the tip of the shaft portion 2 enters the receiving hole 17 for a length of 4 to 5 mm. At the same time as this stop or slightly earlier than this stop, air is jetted from the air jet port 46 by the command signal from the control device 200, and the tip of the shaft portion 2 hits the lower end surface 27 of the guide portion 26. As a result, an insulating gap C is formed. By continuing the air injection following the formation of the insulating gap C, the flange 3 is pressed against the end surface 29 of the lid member 15 and the insulating gap C disappears.

  A signal is transmitted from the detection device 51 to the control device 200 in accordance with the disappearance of the insulating gap C, that is, the conduction of the detection current between the detection conducting wires 34 and 35, and the return operation of the air cylinders 49 and 50 is performed. The electrode air cylinder 56 is operated by a command signal from the device 200, the projection bolt 1 is pressed against the steel plate part 52, and a welding current is supplied to complete welding.

  Next, the operation when there is no axial part will be described.

  The projection bolt 1 is not supported by the socket member 44, and the supply rod 41 advances in an empty state and stops on the electrode axis OO. Almost at the same time as this stop, air is jetted from the air pipe 47 and the air jet port 46 by a command signal from the control device 200. A signal indicating the start of this injection is input to the timing device 58 in the control device 200, and the timing is started. At the same time, the non-energization signal is transmitted from the detection device 51 to the control device 200. The signal of the predetermined time elapsed issued from the time measuring device 58 and the signal of the absence of the component from the detecting device 51 are AND-processed, and the control device 200 sends a command signal to the air control valve 100 not to operate the electrode air cylinder 56. Reportedly. By the operation described above, the absence of parts is detected before the electrode advances, and at the same time, the electrode advance is prohibited.

  In the above operation, the time signal of the time measuring device 58 which starts the operation by the air injection start signal is utilized to prohibit the electrode from advancing in the absence of parts. The operation of the timing device 58 may be initiated by a signal emitted when stopped on O-O. Alternatively, only the non-energization signal between the two detection conductors 34 and 35 due to the absence of parts may be transmitted from the detection device 51 to the timing device 58 to start the timing operation.

  It should be noted that instead of the various air cylinders described above, an electric motor that outputs forward and backward can be used. It is also possible to replace the above various permanent magnets with electromagnets.

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

  The shaft portion 2 of the shaft-shaped component 1 transferred by advancing the supply rod 41 or the like stops at a position coaxial with the receiving hole 17 of the lid member 15, and then the shaft portion 2 is inserted into the receiving hole 17. Then, the end of the shaft portion 2 abuts on the guide portion 26 of the stopper member 23, and the shaft portion 2 is attracted to the guide portion 26 by the attraction force of the magnet 24 acting on the shaft portion 2 via the guide portion 26 and is in a stationary state. become. In this stationary state, an insulating gap C is formed between the flange 3 of the shaft-shaped component 1 and the end surface 29 of the lid member 15. The washer 33, the compression coil spring 36, the stopper member 23, and the shaft-shaped component 1 can be electrically connected to each other from the detection conductor 34, but the flange 3 of the shaft-shaped component 1 and the end surface 29 of the lid member 15 are connected to each other. Since the insulating gap C is formed between them, the detection current does not flow to the lid member 15.

  When the insertion pressure force due to air injection or the like acts on the shaft-shaped component 1 forming the insulating gap C, the tension of the compression coil spring 36 is set to be smaller than the insertion pressure force. While retracting the stopper member 23, the stopper member 23 is retracted to eliminate the insulating gap C, and a conductive contact between the flange 3 and the end surface 29 of the lid member 15 is established. Due to the disappearance of the insulating gap C, a detection current flows from the lid member 15 to the other detection lead wire 35 through the electrode body 5. Since the shaft-shaped component 1 and the insulating gap C are present in the energizing path of the detection current, the shaft-shaped component 1 is received at the stage of being supplied to the electrode, that is, before the electrode advances toward the steel plate component 52. The normal insertion of the shaft-shaped component 1 into the hole 17 can be detected. Since the insulating cylinder 18 that insulates the inner surface of the receiving hole 17 from the shaft portion 2 is provided in the receiving hole 17 for such detection energization, the detection current is interrupted only by opening and closing the insulating gap C.

  By forming the insulating gap C as a minute space, the insulating gap C is surely extinguished by the insertion pressure applied to the projection bolt 1, and the conduction from the flange 3 to the lid member 15 is surely obtained. It is possible to detect high-quality parts. Even if a minute impurity is present in the insulating gap C, the pressing force of the flange 3 on the end surface 29 of the lid member can be increased, so that the electrical continuity between the two can be surely obtained due to the elimination of the insulating gap.

  The insulating gap C is formed after the shaft portion 2 is inserted into the receiving hole 17. After that, the insulating gap C, which is a narrow space, is erased, so that the erase is surely performed. Since the insulating gap C is a narrow gap, it is possible to detect the presence of a component by momentarily closing the gap like a pulse signal. Therefore, highly accurate and highly reliable detection can be obtained with a momentary signal that is reliably transmitted.

  When the shaft-shaped component 1 is not inserted into the receiving hole 17 for some reason, the shaft-shaped component 1 does not function as a conduction mediating member, so that the detection current is supplied from one detection conductor 34 to the other detection conductor 35. Is not performed and the absence of the shaft-shaped component 1 is detected before the advance of the electrode. As a method of detecting the absence of parts, for example, air injection or push rod projection is performed in order to obtain an insertion pressure, and even if a predetermined time has elapsed from that point, one detection conductor 34 to the other detection conductor When the detection current is not supplied to 35, the absence of the supply of current is used as a trigger to detect the absence of the shaft-shaped component 1.

  Since the insulating cylinder 18 that insulates the inner surface of the receiving hole 17 from the shaft portion 2 is provided in the receiving hole 17, energization of the detection current is interrupted only by opening and closing the insulating gap C. It can be simplified.

  By setting the insertion pressure for eliminating the insulating gap C to a predetermined value or more, the flange 3 can be strongly pressed against the end surface 29 of the lid member 15, and the flange 3 and the lid member 15 can be strongly pressed. Conductivity is reliably obtained and good detection operation can be secured.

  Since a momentary energization time for determining the presence of a component is sufficient for closing the insulating gap C and enabling energization, in the case where the insertion pressure is required for the blast air, the blast of the blast air is blasted for a moment. Thus, it is possible to reduce the amount of injected air and pursue economic efficiency. In addition, since the insulation gap C is regenerated by the tension of the compression coil spring 36 after the presence of the component is detected, unnecessary energization and simplification of the control circuit related thereto can be achieved.

  The embodiment of the method for detecting a component in the electric resistance welding electrode is the same as the effect of the embodiment of the electric resistance welding electrode.

  As described above, according to the device of the present invention, it is possible to detect the presence or absence of the shaft-shaped component before the electrode advances and to ensure a reliable detection operation. Therefore, it can be used in a wide range of industrial fields such as car body welding processes for automobiles and sheet metal welding processes for home appliances.

DESCRIPTION OF SYMBOLS 1 Shaft-shaped component, projection bolt 2 Shaft part 3 Flange 4 Welding protrusion 5 Electrode body 10 Guide cylinder 12 Through hole 15 Lid member 17 Receiving hole 18 Insulating cylinder 23 Stopper member 24 Magnet 25 Container 26 Guide part 28 Flange surface 29 End surface 33 Washer 34 Detection Conductive Wire 35 Detection Conductive Wire 36 Compression Coil Spring 40 Supply Mechanism 44 Socket Member 46 Air Injection Port 51 Detection Device 52 Steel Plate Part 100 Air Control Valve 200 Control Device C Insulation Gap OO Electrode Axis

Claims (2)

A shaft part, a flange integrated with the shaft part, and a shaft-shaped part having a welding projection on a flange surface opposite to the shaft part are subjected to electric resistance welding,
A guide tube made of an insulating material is inserted into the metal electrode body, which has a cylindrical shape.
The lid member fixed to the end portion of the electrode body is formed with a receiving hole into which the shaft portion of the shaft-shaped component is inserted,
An insulating cylinder for insulating the inner surface of the receiving hole and the shaft portion is provided in the receiving hole,
In the through hole provided in the guide cylinder, a stopper member consisting of a container for housing a magnet and a guide portion for applying a magnet attraction force to the shaft-shaped component is slidably inserted,
The through hole and the receiving hole are arranged coaxially so that the end portion of the shaft portion inserted into the receiving hole hits the guide portion,
The length of the receiving hole is set so that an insulating gap is formed between the flange of the shaft-shaped component inserted in the receiving hole and the end surface of the lid member,
A compression coil spring for setting the standby position of the stopper member is provided between the washer arranged in the concave hole of the electrode body and the stopper member,
A detection lead wire is connected to the washer and the electrode body,
An electric resistance welding electrode, wherein a tension of the compression coil spring is set to be smaller than an insertion pressure force when the shaft portion is inserted into the receiving hole. A shaft part, a flange integrated with the shaft part, and a shaft-shaped part having a welding projection on a flange surface opposite to the shaft part are subjected to electric resistance welding,
A guide tube made of an insulating material is inserted into the metal electrode body, which has a cylindrical shape.
The lid member fixed to the end portion of the electrode body is formed with a receiving hole into which the shaft portion of the shaft-shaped component is inserted,
An insulating cylinder for insulating the inner surface of the receiving hole and the shaft portion is provided in the receiving hole,
In the through hole provided in the guide cylinder, a stopper member consisting of a container for housing a magnet and a guide portion for applying a magnet attraction force to the shaft-shaped component is slidably inserted,
The through hole and the receiving hole are arranged coaxially so that the end portion of the shaft portion inserted into the receiving hole hits the guide portion,
The length of the receiving hole is set so that an insulating gap is formed between the flange of the shaft-shaped component inserted in the receiving hole and the end surface of the lid member,
A compression coil spring for setting the standby position of the stopper member is provided between the washer arranged in the concave hole of the electrode body and the stopper member,
A detection lead wire is connected to the washer and the electrode body,
Prepare an electric resistance welding electrode in which the tension of the compression coil spring is set to be smaller than the insertion pressure when the shaft portion is inserted into the receiving hole,
A method for detecting a component in an electric resistance welding electrode, characterized in that the stopper member is retracted while the compression coil spring is contracted by the insertion pressure to establish conductive contact between the flange and the end surface of the lid member.

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