JP4683349B2 - Electrodes and welding methods in electrical resistance welding - Google Patents

Description

  According to the present invention, a shaft-like component having a shaft portion, a flange formed integrally with the shaft portion, and a welding protrusion formed on a flange surface opposite to the shaft portion is inserted into an electrode receiving hole. The present invention relates to an electrode for performing electric resistance welding on a counterpart member and a welding method.

  The electrode described in Japanese Patent No. 2789020 includes a shaft part, a flange formed integrally with the shaft part, and a shaft-like component having a welding protrusion formed on a flange surface opposite to the shaft part. It is a target of electric resistance welding, and a guide tube made of an insulating material is inserted into a substantially cylindrical electrode body, and a receiving hole is formed in the electrode end surface in a state of communication with the guide tube, A stopper member for receiving the shaft portion inserted into the receiving hole is disposed in the guide tube in a state where the stopper member can advance and retract, and a coil spring for urging the stopper member toward the electrode end surface is disposed in the electrode body. A predetermined gap is formed between the flange of the shaft-like component inserted into the hole and the end face of the electrode, and the electrode advances to resist the biasing force of the coil spring by pressing the welding protrusion against the mating member. The electrode end face is It is intended to contact with the flange.

  And the electric current which detects that a shaft-shaped component exists normally by the contact of the electrode end surface and flange made as mentioned above flows.

Japanese Patent No. 2789020

  The above-mentioned patent document describes detecting the presence or absence of a shaft-shaped component, but does not describe anything about applying a welding current at an appropriate time when the electrode has advanced to a predetermined position. In general, energization of the welding current is performed by generating a signal at a location where a component supply device such as a projection bolt returns to a certain distance from the electrode and using this signal as a trigger signal. In such a system, it is necessary to bother to arrange a sensor for generating a trigger signal in a part of the component supply device. In such a sensor, there is a problem that the welding position of the sensor is out of order, the return speed of the component supply device is changed, and the energization timing of the welding current cannot be maintained uniformly.

  In addition, since the pressure applied to the mating member of the welding protrusion is not maintained uniformly, the amount of metal melting varies and the welding state is not uniformized. In particular, in a portable electrical resistance welding apparatus, since an operator operates the apparatus by hand, it is difficult to set the pressure applied to the counterpart member of the welding protrusion to a predetermined value. In other words, since the applied pressure changes with the operator's control, the welding state varies, which is not preferable in terms of maintaining the welding quality. Furthermore, if it is a handy type as described above, it may be difficult to weld the shaft-like component vertically to the counterpart member.

  The present invention has been provided to solve the above-described problems, and it is possible to maintain the welding current energization timing accurately with a simple structure and to ensure that the welding pressure is always a uniform value. An object is to provide an electrode and a welding method in electric resistance welding.

The invention according to claim 1 relates to an electrode structure, and includes a shaft portion, a flange formed integrally with the shaft portion, and a welding protrusion formed on a flange surface opposite to the shaft portion. The shaped parts are subject to electric resistance welding,
A guide cylinder made of an insulating material is inserted into a substantially cylindrical metal electrode body, and a receiving hole is formed in the electrode end face in a state of communicating with the guide cylinder, and the inner surface has an insulating structure. A stopper member for receiving the shaft portion inserted into the receiving hole is disposed in the guide tube in a state where the stopper member can advance and retreat, and an urging means for urging the stopper member toward the electrode end surface is disposed in the electrode body. A predetermined interval is formed between the flange of the shaft-like component inserted into the receiving hole and the electrode end surface, and the electrode is advanced and the welding protrusion is pressed against the other member to apply the biasing means. The electrode end face comes into contact with the flange against the force, and the energization signal obtained by this contact is used as a trigger signal for energizing the welding current between the welding protrusion and the mating member, and the predetermined interval disappears and the welding protrusion Partner As the welding current at a time when the pressure force becomes proper pressure against the member is energized, the distance of the biasing force and said predetermined distance of said urging means is selected, the welding projection is properly in the thrust bearing The electrode in electrical resistance welding is characterized in that the current-carrying time is always maintained uniformly under the condition of being pressurized and a uniform welded state is formed.

  Since the inner surface of the receiving hole has an insulating structure and a stopper member is inserted into a guide tube made of an insulating material, the shaft portion of the shaft-shaped component does not contact any part of the metal electrode body. For this purpose, when the electrode advances and the welding projection is pressed against the counterpart member, the electrode end surface comes into contact with the flange against the biasing force of the biasing means, and the energization signal current is Energization is performed between the flanges, and the welding current is energized using the energization as a trigger signal to complete welding.

  Therefore, a trigger signal can be ensured by the close contact between the electrode end face and the flange without employing any special signal generating means, and a structurally simplified electrode can be obtained. The energization timing of the welding current is set to the time when the end face of the electrode is pressed against the flange, and the energization timing is always maintained uniformly in a situation where the welding protrusion is appropriately pressed against the counterpart member. Thereby, a uniform welded state is formed, and good welding quality can be ensured.

Length of the front Symbol predetermined interval, that is the value compression reaction force of the biasing means to be example when the electrode end face is in contact with the flange can set predetermined pressure against the thrust bearing of the welding projection.

  When the distance between the electrode end face and the flange, which is the predetermined distance, disappears, the amount of compression with respect to the urging means becomes uniform, and the compression reaction force of the urging means always becomes uniform. Accordingly, the pressure applied to the mating member of the welding projection becomes a constant load, the amount of molten metal is made constant, and good welding quality can be ensured.

  In particular, in a portable electrical resistance welding apparatus, since an operator operates the apparatus by hand, it is difficult to set the pressure applied to the counterpart member of the welding protrusion to a predetermined value. In other words, since the applied pressure changes depending on the operator's control, the welding state varies, which is not preferable in terms of maintaining the welding quality. However, in the present invention, a uniform pressure can be always obtained as described above, so that such a problem of welding quality is solved. Furthermore, even with the handy type as described above, since the electrode end face is welded in close contact with the flange, the axial part is made perpendicular to the counterpart member, so that the shaft-like component is attached to the counterpart member. It becomes possible to weld vertically.

And configured to detect that the shaft-like part is inserted into the receiving hole by energization signal for example by a previous SL contact.

  With such a configuration, even if the shaft-shaped component is not held by the electrode for any reason, it is possible to detect the absence of the shaft-shaped component before the welding current is applied. The problem of defective products can be prevented.

The invention according to claim 2 relates to a welding method, and includes a shaft portion, a flange formed integrally with the shaft portion, and a welding protrusion formed on a flange surface opposite to the shaft portion. In this case, a guide tube made of an insulating material is inserted into a substantially cylindrical metal electrode body, and opens in the end face of the electrode in a state of communicating with the guide tube. A receiving hole is formed and the inner surface thereof has an insulating structure, and a stopper member that receives the shaft portion inserted into the receiving hole is disposed in the guide cylinder in a state in which the stopper member can advance and retract. A biasing means for biasing in the direction is disposed in the electrode body, a predetermined interval is formed between the flange of the shaft-like component inserted into the receiving hole and the electrode end surface, and the electrode advances to form a welding projection. By being pressed against the counterpart member, The electrode end surface comes into contact with the flange against the biasing force of the biasing means, and an electrode is prepared in which the energization signal obtained by this contact is used as a trigger signal for welding current energization between the welding projection and the mating member. that the electrode, as welding current at a time when the pressure force on the thrust bearing of the fusion bonding projection predetermined intervals disappeared becomes proper pressure is energized, the biasing force and the of the biasing means A distance of a predetermined interval is selected, and when the electrode advances and the welding projection is pressed against the other member, the electrode end surface is brought into contact with the flange, and an energization signal obtained by this contact is a trigger signal. Then, a welding current is passed between the welding protrusion and the mating member so that the energization timing is always maintained uniformly in a state where the welding projection is properly pressurized to the mating member, and a uniform welding state is formed. A welding method in the electric resistance welding, characterized in that the.

  Therefore, as described above, the welding current is energized simply by contacting the electrode end face with the flange, and a trigger signal can be secured by the close contact between the electrode end face and the flange without employing a special signal generating means. The energization time of can be kept uniform. That is, the energization timing of the welding current is set to the time when the electrode end face is pressed against the flange, and the energization timing is always maintained uniformly in a situation where the welding protrusion is appropriately pressed against the counterpart member. Thereby, a uniform welded state is formed, and good welding quality can be ensured.

  The present invention is an apparatus invention as described above, but as can be seen from the embodiments described below, it can be present as a portable electric resistance welding apparatus.

It is sectional drawing of an electrode. It is a load and a deflection curve which shows the applied pressure of an electrode. It is a side view which shows the practical example of an electrode. It is sectional drawing which shows an insulation structure. It is a side view of a projection bolt.

  Below, the form for implementing the electrode and welding method in the electrical resistance welding of this invention is demonstrated.

  1 to 5 show a first embodiment of the present invention.

  First, the shaft-like parts to be welded will be described.

  There are various shapes of the shaft-shaped component, and the shaft-shaped component here is an iron projection bolt shown in FIG. In the following description, the projection bolt may be simply expressed as a bolt.

  The projection bolt 1 is formed on a shaft portion 2 on which a male screw is formed, a circular flange 3 concentric with the shaft portion 2 and formed integrally with the shaft portion 2, and a flange surface opposite to the shaft portion 2. It is comprised from the welding protrusion 4 which was. The dimensions of each part are such that the diameter of the shaft part 2 is 6 mm, the length of the shaft part 2 is 27 mm, and the diameter of the flange 3 is 14 mm.

  Next, the structure of the electrode will be described.

  The entire electrode is indicated by reference numeral 5. The electrode body 6 is a cylindrical member made of a copper alloy material such as chrome copper. The electrode body 6 includes a first member 8 fixed to the mounting member 7, a second member 10 coupled to the first member 8 via a screw portion 9, and an end portion of the second member 10. It is comprised from the end member 12 couple | bonded through the thread part 11. As shown in FIG. The end surface of the end member 12 is a flat electrode end surface 13 that is in close contact with the flange 3.

  A guide tube 14 made of a synthetic resin insulating material such as urethane resin or polyamide resin is inserted inside the second member 10, and a large diameter hole 15 and a small diameter hole 16 communicating with the large diameter hole 15 are formed inside the guide cylinder 14. It is. A receiving hole 17 into which the shaft portion 2 is inserted is provided in the end member 12. One end of the receiving hole 17 communicates with the small diameter hole 16 of the guide cylinder 14, and the other end opens to the electrode end surface 13. The central axis of the receiving hole 17 is coaxial with the central axis of the electrode body 6.

  The inner surface of the receiving hole 17 has an insulating structure. The insulating structure here is constituted by an insulating cylinder 18 and an air gap 19 fitted in the end member 12. The inner diameter of the insulating cylinder 18 is set slightly larger than the outer shape of the shaft portion 2, and the inner diameter of the space 19 is set sufficiently larger than the outer shape of the shaft portion 2. With such a dimension setting, even if the shaft portion 2 is tilted, the tilt angle is slight, so that the shaft portion 2 is not in contact with the inner surface portion of the gap 19. With this configuration, the gap 19 also forms an insulating structure. The inner diameter of the insulating cylinder 18 is the same as the inner diameter of the small diameter hole 16.

  A stopper member 21 for receiving the shaft portion 2 inserted into the receiving hole 17 is disposed in the guide tube 14 in a state where the stopper member 21 can advance and retreat. The stopper member 21 includes a cylindrical main member 22 that slides against the inner surface of the large-diameter hole 15 and a sub-member 23 that enters the small-diameter hole 16 and receives the end of the shaft portion 2. Has been. In order to embed a permanent magnet 24 as a suction means in the main member 22, the main member 22 is divided into two parts, and both are integrated by a welded portion 25.

  An insulating cup 26 made of a synthetic resin insulating material such as urethane resin or polyamide resin is inserted inside the first member 8 in a state of opening downward, and a copper alloy terminal plate 27 is inserted in the back thereof. Is arranged. A compression coil spring 28 as an urging means is inserted between the terminal plate 27 and the stopper member 21, and the tension is mainly applied to the stopper surface 29 formed at the boundary between the large diameter hole 15 and the small diameter hole 16. The member 22 is received by hitting.

  In the state where the main member 22 is in close contact with the stopper surface 29 as described above, since the attractive force of the permanent magnet 24 is acting on the shaft portion 2, the end portion of the shaft portion 2 is in contact with the end surface of the sub member 23. Adsorbed. In this state, a gap L is provided between the electrode end face 13 and the flange 3. The bolt 1 is prevented from falling out of the receiving hole 17 by the attractive force of the permanent magnet 24.

  When the electrode 5 advances and the welding projection 4 is pressed against the counterpart member 31 (steel plate part 31), the compression coil spring 28 is compressed while the gap L is subsequently reduced, and the welding projection 4 is applied to the counterpart member 31. Pressure increases. This applied pressure becomes the maximum value when the gap L becomes zero. The spring constant of the compression coil spring 28 and the gap L are set so that this maximum pressure is an appropriate pressure. In the illustrated case, the gap L is 6 mm. This maximum pressing force is set in the range of 100N to 250N when the bolt 1 having the dimensions as described above is welded to the steel plate part 31 (the counterpart member 31) having a thickness of 0.7 mm. Here, it is 200N. Further, the welding current is 9500 A, and the energization time is 6 cycles (1 cycle = 1/60 seconds). The load / deflection curve of the compression coil spring 28 described above is shown in FIG. The counterpart member 31 is positioned on the support jig 32.

  The urging means is the compression coil spring 28. Alternatively, it is possible to cause the pressure of the compressed air to act on the upper surface of the stopper member 21 so as to function as an air spring.

  Next, energization control of the welding current will be described.

  The terminal plate 27 is connected to the positive side of the power supply of the detection current by a conducting wire 33. The detection current is connected to the terminal plate 27, the compression coil spring 28, the stopper member 21, and the shaft portion 2 as shown in FIG. , Through the flange 3, the electrode end face 13, and the electrode main body 6, the current flows through the negative conduction wire 34 connected to the first member 8.

  The detection current, that is, the energization signal is used as a trigger signal for energizing the welding current between the welding projection 4 and the steel plate part 31. Various circuit configurations for using the energization signal as a trigger signal can be employed. Here, a relay switch 35 that operates by energization of a detection current is employed. This relay switch 35 is a general one, and is a combination of a coil 36, a moving iron core 37, and a switching contact 38.

  Reference numeral 39 denotes a control device composed of a sequence circuit, a computer device, and the like. When the switching contact 38 is closed, an operation signal is input to the control device 39, and a welding command signal based on this input signal is sent from the control device 39 to the welding current. It is transmitted to the transformer 40. As a result, the welding current having the current value is supplied from the conductor 41 to the mounting member 7, and the welding projection 4 and the steel plate part 31 are welded. Further, the energization time of the six cycles is set by a timer device equipped in the control device 39.

  As shown in FIG. 1B, when the electrode end face 13 is in close contact with the flange 3 and a detection current, that is, an energization signal flows from the conducting wire 33 to the conducting wire 34, the bolt 1 is normally inserted into the receiving hole. Is confirmed. If the bolt 1 is not inserted into the receiving hole 17 for any reason, even if the electrode end face 13 contacts the steel plate part 31, the energization signal does not flow from the conducting wire 33 to the conducting wire 34. This phenomenon of no flow is detected and it is confirmed that the bolt 1 does not exist. In order to confirm that this energization signal does not flow, an AND process is performed to indicate that a certain time has elapsed after the electrode 5 has advanced, and that the energization signal does not flow from the conduction line 33 to the conduction line 34. When an AND requirement is satisfied, warning means (not shown) such as a warning lamp and a warning buzzer are operated.

  FIG. 4 shows another insulating structure on the inner surface of the receiving hole 17. The receiving hole 17 is formed by inserting an insulating cylinder 43 made of a synthetic resin insulating material such as urethane resin or polyamide resin into the end member 12. The opening side of the receiving hole 17 is a tapered hole 44, which can be smoothly inserted so as not to get caught anywhere when the shaft portion 2 is inserted. Alternatively, an insulating material such as a ceramic material can be sprayed on the metal inner surface of the receiving hole 17 formed in the end member 12.

  FIG. 3 shows an example in which the electrode 5 is put into practical use. In FIG. 3A, an air cylinder 46 is fixed to a stationary member 45, and the mounting member 7 is coupled to a piston rod 47 thereof. Other configurations are the same as those in the example of FIG. 1 including portions not shown, and members having the same functions are denoted by the same reference numerals. FIG. 2B shows a portable electric resistance welding apparatus, in which an attachment member 7 is fixed to a handle 48 held by an operator. The other configuration is the same as that of the previous example including a portion not shown, and the same reference numerals are described for members having similar functions.

  In place of the air cylinder 46, an electric motor that performs forward / backward output can also be employed.

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

  Since the inner surface of the receiving hole 17 has an insulating structure, and the stopper member 21 is inserted into the guide tube 14 made of an insulating material, the shaft portion 2 of the bolt 1 contacts anywhere on the metal electrode body 6. There is nothing. For this purpose, the electrode 5 is advanced and the welding protrusion 4 is pressed against the steel plate part 31 as the counterpart member, so that the electrode end face 13 resists the spring force of the compression coil spring 28 as the biasing means. Comes into contact with the flange 3, and an energization signal current is energized between the electrode end face 13 and the flange 3, and the welding current is energized using this energization as a trigger signal to complete the welding.

  Therefore, the trigger signal can be secured by the close contact between the electrode end face 13 and the flange 3 without using any special signal generating means, and the electrode 5 that is structurally simplified can be obtained. And the energization time of welding current is made into the time when the electrode end surface 13 was crimped | bonded to the flange 3, and the energization time is always maintained uniformly in the condition where the welding protrusion 4 was pressurized appropriately to the steel plate component 31. Thereby, a uniform welded state is formed, and good welding quality can be ensured.

  The predetermined distance L is a predetermined pressure applied to the steel plate part 31 of the welding projection 4 in a state corresponding to the compression reaction force of the compression coil spring 28 obtained when the electrode end face 13 contacts the flange 3. The value can be set.

  When the distance between the electrode end face 13 and the flange 3 that is the distance L of the predetermined distance disappears, the amount of compression with respect to the compression coil spring 28 becomes uniform, and the compression reaction force of the compression coil spring 28 always becomes uniform. . Therefore, the pressure applied to the steel plate part 31 by the welding protrusion 4 becomes a constant load in a state corresponding to the distance L, the amount of molten metal is made constant, and good welding quality can be secured.

  In particular, in the portable type electric resistance welding apparatus of the type as shown in FIG. 3B, the operator holds the apparatus by hand, so the pressure applied to the steel plate part 31 by the welding protrusion 4 is as follows. Is difficult to set to a predetermined value. In other words, since the applied pressure changes depending on the operator's control, the welding state varies, which is not preferable in terms of maintaining the welding quality. However, in the present embodiment, as described above, since a uniform applied pressure can be always obtained in a state corresponding to the distance L, such a problem of welding quality is solved. Furthermore, even in the handy type as described above, since the electrode end face 13 is welded in close contact with the flange 3, the bolt 1 is attached to the steel plate part 31 by making the electrode axis line perpendicular to the steel plate part 31. It becomes possible to weld perpendicularly to.

  It is configured to detect that the bolt 1 is inserted into the receiving hole 17 by an energization signal obtained by contact between the electrode end face 13 and the flange 3.

  With such a configuration, even if the bolt 1 is not held by the electrode 5 for some reason, the absence of the bolt 1 can be detected before the welding current is applied, The problem of defective products can be prevented. Since the energization signal obtained by the contact between the electrode end face 13 and the flange 3 can be used as two trigger signals for starting energization of the welding current and detecting the absence of the bolt 1, the circuit configuration is simplified.

  In the embodiment relating to the welding method, the bolt 1 including the shaft portion 2, the flange 3 formed integrally with the shaft portion 2, and the welding protrusion 4 formed on the flange surface opposite to the shaft portion 2 is provided. A receiving hole 17 that is an object of electric resistance welding and that opens in the electrode end face 13 and into which the shaft portion 2 is inserted is formed, and the flange 3 and the electrode of the bolt 1 inserted into the receiving hole 17 Preparing an electrode 5 in which a predetermined interval L is formed between the end faces 13, the electrode 5 is advanced and the welding projection 4 is pressed against the steel plate part 31, thereby bringing the electrode end face 13 into contact with the flange 3; An energization signal obtained by this contact is used as a trigger signal to energize a welding current between the welding projection 4 and the steel plate part 31.

  Therefore, as described above, the welding current is energized simply by the electrode end surface 13 coming into contact with the flange 3, and a trigger signal is secured by the close contact between the electrode end surface 13 and the flange 3 without employing any special signal generating means. It is possible to maintain a uniform welding current energization time. That is, the energization timing of the welding current is set to the time when the electrode end face 13 is pressed against the flange 3, and the energization timing is always maintained uniformly in a situation where the welding projection 4 is properly pressed against the steel plate part 31. Thereby, a uniform welded state is formed, and good welding quality can be ensured.

  As described above, according to the electrode and the welding method of the present invention, it is possible to accurately maintain the energization timing of the welding current with a simple structure, and it is possible to always ensure a uniform welding pressure. Therefore, it can be used in a wide range of industrial fields such as automobile body welding processes and home appliance sheet metal welding processes.

DESCRIPTION OF SYMBOLS 1 Projection bolt, shaft-shaped component 2 Shaft part 3 Flange 4 Welding protrusion 5 Electrode 6 Electrode main body 13 Electrode end surface 14 Guide cylinder 17 Receiving hole 18 Insulating cylinder 19 Gap 21 Stopper member 24 Permanent magnet, Attraction means 28 Compression coil spring Lance means L Clearance 31 Counterpart member, steel plate part 33 Conducting wire 34 Conducting wire 35 Relay switch 39 Control device 40 Welding current transformer 41 Conducting wire 43 Insulating cylinder 48 Handle

Claims (2)

The shaft part, the flange formed integrally with the shaft part, and the shaft-like component provided with the welding protrusion formed on the flange surface on the opposite side of the shaft part are objects of electric resistance welding,
A guide cylinder made of an insulating material is inserted into a substantially cylindrical metal electrode body, and a receiving hole is formed in the electrode end face in a state of communicating with the guide cylinder, and the inner surface has an insulating structure. A stopper member for receiving the shaft portion inserted into the receiving hole is disposed in the guide tube in a state where the stopper member can advance and retreat, and an urging means for urging the stopper member toward the electrode end surface is disposed in the electrode body. ,
A predetermined interval is formed between the flange of the shaft-like component inserted into the receiving hole and the electrode end surface,
When the electrode advances and the welding protrusion is pressed against the other member, the electrode end surface comes into contact with the flange against the urging force of the urging means, and an energization signal obtained by this contact is generated between the welding protrusion and the other member. It is a trigger signal for welding current conduction between members,
As the welding current at a time when the pressure force on the thrust bearing of the fusion bonding projection predetermined intervals disappeared becomes proper pressure is energized, the biasing force and said predetermined distance of said urging means The distance is selected,
An electrode in electric resistance welding, wherein the current-carrying timing is always maintained uniformly and a uniform welded state is formed in a state where the welding protrusion is appropriately pressed to the counterpart member. The shaft part, the flange formed integrally with the shaft part, and the shaft-like component provided with the welding protrusion formed on the flange surface on the opposite side of the shaft part are objects of electric resistance welding,
A guide cylinder made of an insulating material is inserted into a substantially cylindrical metal electrode body, and a receiving hole is formed in the electrode end face in a state of communicating with the guide cylinder, and the inner surface has an insulating structure. A stopper member for receiving the shaft portion inserted into the receiving hole is disposed in the guide tube in a state where the stopper member can advance and retreat, and an urging means for urging the stopper member toward the electrode end surface is disposed in the electrode body. ,
A predetermined interval is formed between the flange of the shaft-like component inserted into the receiving hole and the electrode end surface,
When the electrode advances and the welding protrusion is pressed against the other member, the electrode end surface comes into contact with the flange against the urging force of the urging means, and an energization signal obtained by this contact is generated between the welding protrusion and the other member. Prepare an electrode to be a trigger signal for welding current conduction between members,
The prepared the electrodes, as the welding current at a time when the pressure force on the thrust bearing of the fusion bonding projection predetermined intervals disappeared becomes proper pressure is energized, the biasing of said biasing means A power and a distance of the predetermined interval are selected,
When the electrode advances and the welding protrusion is pressed against the mating member, the electrode end surface is brought into contact with the flange, and an energization signal obtained by this contact is used as a trigger signal to generate a welding current between the welding projection and the mating member. A welding method in electrical resistance welding, wherein the current supply time is always maintained uniformly and a uniform welded state is formed under the condition that the welding projection is appropriately pressed against the counterpart member by energization.

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