JP2007000925A - Electric resistance welding equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide electric resistance welding equipment capable of shortening an operation time, and adequately setting the operation start timing of a welding machine. <P>SOLUTION: In the electric resistance welding equipment, a movable electrode 7 is provided to a base 1 at a predetermined spacing. Also, there are provided a first stop position at which a steel plate component 8 is fed, a second stop position at which a projection nut 18 is fed on the steel plate component 8, and a third stop position at which the nut 18 is welded to the steel plate component 8. The nut 18 is constituted to wait at the second stop position in advance, and a control means 34 for emitting the operation start signal of a movable electrode 54 at the third stop position by the feeding operation of at least the projection nut 18 is provided. Thus, the nut can be fed simultaneously when the movable electrode 7 is stopped at the second stop position. Consequently, the operation time can be shortened, and the welding operation can be achieved at correct timing. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electric resistance welding apparatus, and is suitable for shortening the welding process time in a welding process in which, for example, a projection nut is welded to a steel plate part.

  A base that moves at a predetermined movement interval is provided, and a steel plate part and a projection nut are placed on the moving electrode arranged on the base, and the steel plate part and the projection nut on the moving electrode are added by the movable electrode. It is known that a projection nut is electrically resistance-welded to a steel plate part by applying a welding current while pressing.

Japanese Patent Publication No. 60-51953 discloses a turntable in which the base is rotated intermittently, that is, an index table. An auxiliary electrode is installed on the index table at a predetermined rotation interval. It is disclosed that a steel plate part or a projection nut is placed, these parts are pressurized with a movable electrode, and a welding current is applied. In particular, in the publication, a step of placing a steel plate component on the auxiliary electrode, a step of placing a projection nut on the steel plate component, and a step of electrically resistance welding the steel plate component and the projection nut are sequentially performed. Is disclosed.
Japanese Patent Publication No. 60-51953 Japanese Patent No. 2832528 Japanese Patent No. 3306579 Japanese Patent No. 3326490

  However, the technique disclosed in Patent Document 1 has the following problems.

  That is, the projection nut is of a type that is supplied by the parts supply pipe after the auxiliary electrode has moved to a predetermined position. That is, the projection nut is supplied through the parts supply pipe after the auxiliary electrode stops at a predetermined position. Therefore, the nut supply time by the parts supply pipe is added to the operation time of the entire apparatus, which is not preferable for shortening the operation time of the apparatus.

  In addition, there is a problem that the setting of the timing at which the movable electrode has advanced and the projection nut is pressurized and the welding current is applied to the steel plate component is not performed in a reliable and appropriate manner.

  Further, the means for supplying the projection nut is configured in the form of a part supply pipe that is directed obliquely from above to the auxiliary electrode, and the nut supply is configured to be moved on the supply pipe and placed on the auxiliary electrode. Therefore, if the position of the tip of the parts supply pipe is slightly out of position, there is a problem that the nut is not placed accurately with respect to the target location, and the operation reliability of the apparatus is poor.

  On the other hand, the techniques disclosed in Patent Documents 2 to 4 have the following problems.

  That is, it is disclosed that the projection nut is held at the tip portion of the advancing and retracting supply rod, but no consideration is given to shortening the intermittent operation time of the welding apparatus having the movable base.

  The present invention has been provided to solve the above-described problems, and an object thereof is to provide an electric resistance welding apparatus capable of shortening the operation time and appropriately setting the operation start timing of the welding machine.

Means to solve the problem

  The present invention has been provided to solve the above-mentioned problems. The invention according to claim 1 is directed to a steel plate component and a projection on a moving electrode attached to a base that moves at a predetermined movement interval. In the type in which the nut is placed, the steel plate part on the moving electrode and the projection nut are pressurized with the movable electrode and the welding current is applied, and the projection nut is electrically resistance welded to the steel plate part. A plurality of the bases are arranged at the same intervals as the movement intervals, and the movement bases move at the movement intervals, so that each moving electrode takes at least a first stop position, a second stop position, and a third stop position. A component supply means configured to supply a steel plate component so as to be in a state of being placed on the moving electrode stopped at the first stop position is provided, and the second stop position A steel plate on the moving electrode stopped at the third stop position is provided with a projection nut supplying means for supplying a projection nut onto the steel plate component placed at the first stop position on the moving electrode stopped at the first stop position. A movable electrode for applying pressure and welding current to the component and the projection nut is provided, and the projection nut supply means is configured to wait in advance at the second stop position while holding the projection nut. The electric resistance welding apparatus is characterized in that a control means for generating an operation start signal of the movable electrode at the third stop position by the operation of the projection nut supply means is provided.

  Hereinafter, the description “projection nut” may be simply expressed as “nut”.

The invention's effect

  With the above configuration, the steel plate component held by the component supply unit is placed on the moving electrode stopped at the first stop position. Then, when the base moves and the moving electrode moves a predetermined moving distance, the projection nut is placed on the steel plate part by the projection nut supplying means at the second stop position. The projection nut supply means waits in advance at the second stop position while holding the nut. When the moving electrode moves to the second stop position and stops, the projection nut is immediately transferred onto the steel plate part.

  As described above, the moving electrode on which the projection nut is placed on the steel plate part at the second stop position moves to the third stop position by the movement of the base, and the movable electrode can enter the advancing operation.

  The advance operation of the movable electrode is performed by an operation start signal from the control means. As this operation start signal, a signal obtained by at least the operation of the projection nut supply means at the second stop position is input to the control means, and is thereby transmitted from the control means.

  As described above, in the second stop position, the projection nut supply means holding the nut waits for the arrival of the mobile electrode on which the steel plate component is placed, so that the mobile electrode stops at the second stop position. At the same time, nuts are supplied. Therefore, the nut can be supplied at the same time when the moving electrode arrives at the second stop position, and the operation time of the apparatus can be shortened. In other words, since there is no useless movement that the projection nut supply means starts the supply operation after the moving electrode arrives at the second stop position, it is effective for shortening the time.

  As described above, the advancing operation of the movable electrode is executed with the operation of the projection nut supply means at the second stop position as a trigger. Therefore, with respect to the steel plate part and the nut on the moving electrode that are correctly stopped at the third stop position, the movable electrode can reliably advance and complete the welding. That is, since the welding at the third stop position is performed using the movement of the projection nut supply means at the second stop position, the welding operation is reliably achieved, and the operation reliability as the apparatus is improved.

  Further, the operability of the projection nut supply means itself is reduced in time, and the movement of the projection nut supply means is used to start the operation of the movable electrode, so that the projection nut supply means reduces the operation time of the apparatus. Accurate operation of the movable electrode is realized, and the supply means is substantially multi-functional and effective for simplifying the structure.

  Since the nut is held by the projection nut supply means and is waiting at the second stop position, the nut can be accurately transferred to a predetermined location. That is, since the nut can be held in the projection nut supply means in a half-constrained state, the relative position between the waiting nut and the target supply location can be accurately obtained, and the nut is supplied to the shifted position. There is no such thing.

  The invention according to claim 2 is the electric resistance welding apparatus according to claim 1, wherein each moving electrode is provided with a guide hole that enters a positioning hole formed in the steel plate part and a screw hole of the projection nut.

  With the above configuration, when the steel plate component is placed on the moving electrode, the guide pin relatively penetrates the prepared hole formed in the steel plate component, and the relative position between the steel plate component and the moving electrode can be set accurately. In addition, since the guide pin relatively penetrates into the screw hole of the projection nut, the nut can be supplied to the correct position with respect to the moving electrode and the steel plate part.

  The invention according to claim 3 is the electrical resistance welding apparatus according to claim 1 or 2, wherein the base is a rotary index table.

  With the above configuration, since the base is a rotary index table, the stop position from the first stop position to the third stop position can be accurately set by rotating the table by a predetermined angle. Can be performed accurately.

  The invention according to claim 4 is the electric resistance welding apparatus according to claim 1 or 2, wherein the base is an advancing and retracting index table.

  With the above configuration, since the base is an advancing / retracting index table, the stop position from the first stop position to the third stop position can be accurately set by moving the table by a predetermined rectilinear distance. Can be performed accurately.

  The invention according to claim 5 is the electric resistance welding apparatus according to any one of claims 1 to 4, wherein the projection nut supply means is an advancing / retracting or swinging supply rod.

  With the above configuration, the projection nut can be held on the supply rod, and the nut can be made to wait in advance at the second stop position. Since the projection rod is held by the supply rod that moves back and forth or swings in this way, the nut is securely held by the supply rod, and the position of the nut shifts during the movement of the supply rod. It can be prevented from falling off.

  According to a sixth aspect of the present invention, a holding recess for the projection nut is formed at the tip of the supply rod, and the supply rod is retracted after the guide pin relatively enters the screw hole of the projection nut. The electric resistance welding apparatus according to claim 5.

  With the above configuration, when the screw hole of the nut held in the holding recess of the supply rod becomes coaxial with the guide pin of the moving electrode, the supply rod moves in the axial direction of the guide pin, and the guide pin relatively moves into the screw hole. enter in. When the supply rod retreats in the state of entering in this manner, the nut remains on the steel plate part while being locked to the guide pin. Since the supply rod moves backward with the guide pin entering the screw hole of the nut in this way, the steel plate part and the nut are securely placed on the moving electrode, and welding is performed at the third stop position, which is the next process. On the other hand, the best preparation is completed, and a device with high operational reliability is obtained.

  A seventh aspect of the present invention is the electrical resistance welding apparatus according to any one of the second to sixth aspects, wherein an advance / retreat driving means for advancing / retreating the guide pin is provided.

  The guide pin is retracted from the moving electrode by the advance / retreat driving means, and the nut held by the projection nut supply means is stopped at a position coaxial with the moving electrode in this state, and then the guide pin is projected by the advance / retreat driving means. To enter the screw hole of the nut. The projection nut supply means is moved backward while keeping such an approaching state.

  Therefore, the projection nut supply means only needs to move forward and backward, and it is not necessary to form a motion in the direction orthogonal to the forward and backward movement, that is, square motion. Therefore, the operation of the projection nut supply means is simplified, and the same supply is performed accordingly. The operation structure by means of an air cylinder or the like can be simplified.

  The invention according to claim 8 is the electric resistance welding apparatus according to any one of claims 1 to 7, wherein a plurality of the projection nut supply means are arranged.

  Thus, by providing a plurality of projection nut supply means, nuts of different sizes and shapes can be supplied in accordance with changes in the steel plate parts. That is, even if the type of the steel plate part changes, it is possible to immediately supply a nut suitable for it, so that welding can proceed efficiently without stopping the apparatus. Further, it is possible to hold a plurality of nuts in the projection nut supply means and supply them to a plurality of locations of the steel plate parts at a time, which is effective for improving the efficiency of the apparatus.

  According to a ninth aspect of the present invention, a steel plate part and a projection nut are placed on a moving electrode attached to a base that moves at a predetermined moving interval, and the steel plate part and the projection nut on the moving electrode are moved by a movable electrode. In the type in which a welding current is applied and a projection current is electrically resistance welded to a steel plate part, a plurality of the moving electrodes are arranged on the base at the same interval as the moving interval, and the base is moved at the moving interval. Each moving electrode is configured to take at least a first stop position, a second stop position, and a third stop position by moving, and is placed on the move electrode stopped at the first stop position. Projection nut supply means for supplying the projection nut so as to be in a state is provided, and the moving electrode stopped at the second stop position has the Steel plate component supply means for supplying a steel plate component on a projection nut placed at one stop position is provided, and pressurization is applied to the projection nut and the steel plate component on the moving electrode stopped at the third stop position. A movable electrode for energizing a welding current is provided, and the steel plate component supply means is configured to wait in advance at the second stop position while holding the steel plate component, and at least the third steel plate by the operation of the steel plate component supply means. An electric resistance welding apparatus is provided with a control means for generating an operation start signal of the movable electrode at the stop position.

  According to the ninth aspect of the present invention, the projection nut is first supplied at the first stop position, the steel plate part is supplied above the nut at the second stop position, and the steel plate part is supplied to the steel plate part by the movable electrode at the third stop position. The nut is to be welded. That is, it differs from the invention of claim 1 in that a nut is welded to the back side of the steel plate part. Other functions and effects are the same as those of the first aspect.

  Next, the best mode for carrying out the electric resistance welding apparatus of the present invention will be described.

  FIG. 1 is a plan view of an electric resistance welding apparatus, and FIG. 2 is a cross-sectional view of (2)-(2). In this embodiment, a base that moves at a predetermined movement interval is a rotary index table. Has been.

  The index table 1 is formed of a thick plate material in a circular shape, and is rotated about a rotating shaft 2 that stands up substantially in the vertical direction. The rotating shaft 2 is supported in a rotatable state by a support 4 fixed on a stationary member 3.

  As shown in FIG. 2, an index motor 5 is attached to the support 4, and the rotating shaft 2 is driven by the rotational force. Such a drive mechanism can be realized by a commonly used worm gear mechanism, timing chain mechanism, or the like.

  The movement interval of the index table 1, that is, one rotation angle is 60 degrees, and six stop positions are arranged. Various methods can be employed when the index table is rotated 60 degrees or, if necessary, 120 degrees. As a general method, a pulse number signal corresponding to a rotation angle of 60 degrees or 120 degrees is input to the index motor 5, and a braking device (not shown) is operated when the number of pulses is satisfied.

  As shown in FIG. 2, the index motor 5 is provided with a base position confirmation sensor 6 for confirming that the index table 1 has stopped at a predetermined position. The sensor 6 counts the number of pulses and confirms the base position.

  On the index table 1, moving electrodes 7 are attached at intervals of 60 degrees on one virtual circle concentric with the table. A support jig 9 and a clamp device 10 for the steel plate part 8 are arranged at locations corresponding to these moving electrodes 7. The steel plate part 8 is a square flat plate-like accessory part.

  FIG. 4 is a cross-sectional view of the moving electrode 7. Although not shown, the moving electrode 7 has a circular cross section, that is, a cylindrical shape, and is fixed to the index table 1 in the through holes 11 that are spaced at an interval of 60 degrees via insulating cylinders 12. A cylinder 13 is formed in the moving electrode 7, and a piston 14 is slidably inserted therein. A guide pin 15 is fixed to the center of the piston 14 and protrudes from the center of the moving electrode 7 to the outside. In order to maintain this protruding state, a compression coil spring 17 is interposed between the piston 14 and the inner end face 16 of the cylinder 13.

  Further, the moving electrode 7 is formed with an upper end surface 22 on which the steel plate component 8 is placed and a lower end surface 23 received by a fixed electrode described later.

  In the projection nut 18, a screw hole 20 is formed at the center of a rectangular main body 19, and welding projections 21 are provided at four corners of the main body 19.

  The insulating cylinder 12 is made of Teflon (trade name) or polyamide resin having excellent heat resistance. The index table 1 is made of stainless steel, which is a nonmagnetic material.

  As shown in FIG. 3, the support jig 9 has a step structure, whereby a placement surface 24 is formed, and the placement surface 24 and the upper end surface 22 of the moving electrode 7 exist on one virtual plane. The positions of both surfaces 24 and 22 are set. The support jig 9 is provided with suction means for the steel plate part 8. As this suction means, a vacuum suction means, a magnet suction means, or the like can be adopted. Here, it is the latter type of magnet, and a permanent magnet 25 is embedded below the mounting surface 24. The support jig 9 is also made of a non-magnetic material such as stainless steel so that the attractive force of the permanent magnet 25 acts on the steel plate part 8 more strongly.

  As shown in FIG. 1, in order to place the steel plate part 8 on the moving electrode 7, a loading device 27 which is a part supply means is provided. As in the state shown in FIG. 1, the position where the moving electrode 7 is stopped facing the loading device 27 is the first stop position.

  Various types of loading device 27 can be used. In this example, the mechanism is a combination of an advance / retreat operation and a rotation operation. That is, the vacuum cup 29 is attached to the tip of the advance / retreat arm 28 so that the advance / retreat arm 28 can be advanced / retracted by the air cylinder 30. The air cylinder 30 is coupled to a rotation device 31. The rotating device 31 employs a mechanism that rotates the rotating shaft 2, for example.

  When the steel plate component 8 is supplied by a component supply device (not shown), it is adsorbed by the vacuum cup 29 and stopped at the position indicated by the solid line in FIG. Next, the advancing / retreating arm 28 advances by the operation of the air cylinder 30 and the steel plate part 8 is placed on the support jig 9 as shown by the two-dot chain line in FIG. 1, where the suction of the vacuum cup 29 is released. . As a result, the steel plate component 8 is placed on the placement surface 24 of the support jig 9 with the guide pin 15 penetrating therethrough (a positioning hole 26 described later). At this time, the permanent magnet 25 is attracted. The force acts on the steel plate part 8 to fix the steel plate part 8.

  When the steel plate part 8 is placed on the upper end surface 22 of the moving electrode 7 and the vacuum cup 29 is retracted, the index table 1 immediately rotates 60 degrees. In order to start this rotational movement, a rotation start sensor 32 is attached to the air cylinder 30, and the index table 1 is rotated 60 degrees by a signal from the sensor 32.

  As shown in FIG. 15, when a signal from the rotation start sensor 32 is input to the control means 34, this signal is processed by the control means 34, and the output signal is sent to the index motor 5 which is the base drive means. Accordingly, the index table 1 is rotated by 60 degrees. The control means 34 can be operated by a normal sequencer circuit or a simple computer device.

  Thus, the steel plate component 8 is prevented from being displaced by operating the clamping device 10 at a position rotated 60 degrees from the first stop position. In the case of a flat and small steel plate part 8, the displacement can be sufficiently prevented only by the attractive force of the permanent magnet 25, so that the clamping device 10 can be omitted.

  In order to take out the completion of clamping by the clamping device 10 as a signal, a clamping completion confirmation sensor 35 is attached to the clamping device 10 as shown in FIG. As shown in FIG. 15, when the signal from the clamp completion confirmation sensor 35 is input to the control means 34, the output signal from the control means 34 is transmitted to the index motor 5 which is the driving means of the base, and the index table. 1 is rotated 60 degrees.

  The position rotated in this way is the second stop position of the movable electrode 7. At the second stop position, the projection nut 18 is placed on the steel plate part 8 placed on the moving electrode 7 at the first stop position. In order to place the nut 18 on the steel plate part 8, a supply device 36 which is a projection nut supply means is arranged.

  Two sets of the supply devices 36 are arranged, and the supply rod 37 advances as shown in the two-dot chain line to place the nut 18 on the steel plate part 8 on the moving electrode 7. The supply device 36 may be arranged in three sets or four sets.

  The detailed structure of the supply device 36 will be described with reference to FIG. A component supply pipe 38 (see FIG. 1) extending from a parts feeder (not shown) is connected to the head member 39. The air cylinder 40 is coupled to the head member 39, and the supply rod 37 is advanced and retracted by the advance and retreat operation. On the other hand, an air cylinder 41 that lifts and lowers the entire supply rod 37 is fixed to the stationary member 3.

  Sensors 42 and 43 for detecting the operation of the supply device 36 (projection nut supply means) are attached to each of the air cylinders 40 and 41. These sensors 42 and 43 transmit a signal for operating a movable electrode of a welding machine described later.

  The nut 18 from the component supply pipe 38 is held at the tip of the supply rod 37, and the supply rod 37 advances by the operation of the air cylinder 40 as shown in FIG. The supply rod 37 stops moving at that position. Next, when the supply rod 37 is lowered by the operation of the air cylinder 41, the guide pin 15 of the moving electrode 7 relatively enters the screw hole 20 of the nut 18. When the supply rod 37 is retracted in this state, the nut 18 remains on the steel plate part 8, and the nut supply is completed.

  The above-described operation including advancement, lowering, retreating and raising of the supply rod 37 is realized by a square motion as indicated by reference numeral 44 in FIG.

  As described above, as shown in FIG. 6, an open groove 45 is formed at the tip of the supply rod 37 in order to retract the supply rod 37 with the guide pin 15 entering the screw hole 20. A holding recess 46 that accommodates the nut 18 is formed at the tip of the supply rod 37, and an open groove 45 is formed in a portion that forms the bottom of the holding recess 46. The open groove 45 is opened at the tip end side of the supply rod 37, and the open portion is indicated by reference numeral 47.

  Although the supply rod 37 is advancing and retracting, it can also be a swinging type. That is, in FIG. 1, a swing mechanism is installed so that the entire supply device 36 can swing.

  A signal indicating that the supply operation of the supply device 36 has been completed can be obtained from various locations, but here, the sensor 42 is used. That is, when the backward movement of the air cylinder 40 is started, a signal is generated from the sensor 42 and input to the control means 34 shown in FIG. Then, the output signal from the control means 34 is transmitted to the index motor 5 which is the driving means of the base, and the index table 1 is rotated by 60 degrees. The position rotated in this way is the third stop position.

  This third stop position is a rotation position corresponding to the welding machine 50. This welding machine 50 is of a type in which an equalizer mechanism 52 is combined with a C-shaped frame 51. An air cylinder 53 is attached to one end of the C-shaped frame 51 so that the movable electrode 54 moves back and forth. A fixed electrode 55 corresponding to the movable electrode is attached to the other end of the C-shaped frame 51.

  The equalizer mechanism 52 has a support shaft 58 installed between the upper support piece 56 and the lower support piece 57 fixed to the stationary member 3 in a substantially vertical direction, and the guide piece 59 fixed to the C-shaped frame 51 is supported on the support shaft. 58 penetrates in a slidable state. Compression coil springs 60 and 61 are interposed between the guide piece 59 and the upper support piece 56 and between the guide piece 59 and the lower support piece 57, respectively. Has penetrated.

  When the base position confirmation sensor 6 confirms that the steel plate part 8 and the nut 18 have moved from the second stop position to the weldable position of the welding machine 50, that is, the third stop position, The projection nut 18 is supplied to the steel plate part 8 at the second stop position, and the welding machine 50 is activated using the operation of the projection nut supply means at this time.

  As shown in FIG. 3, the operation of the supply rod 37 serving as the projection nut supply means is detected by the sensor 43 while the lowering operation of the supply rod 37 is detected by the sensor 43. In this example, a signal transmitted from the sensor 43 by the lowering operation of the supply rod 37 is input to the control means 34 shown in FIG. 15, and the welding machine 50 is activated by an output signal from the control means 34 associated therewith.

  When the starting vibration of the welding machine 50 is transmitted from the control means 34 as described above, operating air is thereby supplied to the air cylinder 53 and the movable electrode 54 advances to pressurize the nut 18. The guide piece 59 moves upward while the compression coil spring 60 of the equalizer mechanism 52 is compressed by the pressure reaction force at this time, and the fixed electrode 55 comes into pressure contact with the lower end surface 23 of the moving electrode 7 by this upward movement. The nut 8 is pressed against the steel plate part 8 by such an equalizer function. Thereafter, a welding current is applied and the nut 18 is welded to the steel plate part 8. A welding location is a portion of the welding projection 21.

  When such a welding process is completed at the third stop position, the index table 1 is moved by 60 degrees and stopped by the welding completion signal, and the clamp of the clamp device 10 is released here to enter an unclamped state. The unclamped state is indicated by reference numeral 63 in FIG. The welding completion signal can be triggered by various operations. For example, when the sensor 62 attached to the air cylinder 53 detects the backward movement of the movable electrode 54, the welding completion signal is sent to the control means 34 shown in FIG. send.

  The unclamped state (63) is detected by a signal from the clamp completion confirmation sensor 35. This signal is input to the control means 34, the index motor 5 is driven, and the movable electrode 7 is further rotated 60 degrees. Move to the location of the final unloading device 64. The unloading device 64 has the same structure as that of the loading device 27. The unloading device 64 performs an operation opposite to the loading operation, and the steel plate part 8 to which the nut 18 is welded is taken out.

  As described above, loading of the steel plate part 8 (first stop position), clamping of the steel plate part 8, supply of the projection nut 18 onto the steel plate part 8 (second stop position), welding by the welding machine 50 (third stop) Position), the unclamping of the steel plate part 8, and the unloading of the steel plate part 8 are performed successively and continuously at intervals of 60 degrees.

  As shown in FIG. 2, a support roller 65 as shown by a two-dot chain line is attached to the stationary member 3 at a position facing the welding machine 50 and is brought into contact with the lower surface of the index table 1 to support the pressure applied by the movable electrode 54. It can be received by the roller 65. By doing so, the inclination of the index table 1 due to welding pressurization can be prevented, and the equalizer mechanism 52 can be stopped.

  Since the permanent magnet 25 is embedded in the support jig 9, the clamping device 10 can be stopped. In addition, the clamp device 10 can be put into an unclamped state at a place where welding is completed by the welding machine 50, and the steel plate part 8 can be dropped by a protruding member (not shown).

  Therefore, the three stop positions in the present invention are the loading of the steel plate part 8 (first stop position), the supply of the projection nut 18 onto the steel plate part 8 (second stop position), and the welding by the welder 50 (third stop). Position) is mandatory.

  FIG. 5 is a cross-sectional view of what is equipped with advance / retreat driving means for forcibly advancing / retreating the guide pin 15 of the moving electrode 7. As the advancing / retreating drive means, one using an electromagnetic solenoid or one using an air cylinder can be adopted. The illustrated example is an air cylinder type.

  Air chambers 67 and 68 are provided above and below the piston 14, and compressed air intake and exhaust pipes 69 and 70 are connected to both the chambers 67 and 68, respectively. Other configurations are the same as those of the example described above, and members having the same functions are denoted by the same reference numerals.

  Initially, since the compressed air is introduced into the air chamber 67, the piston 14 is positioned at the lowest position, whereby the tip of the guide pin 15 moves backward without protruding from the upper end surface 22 of the moving electrode 7. ing.

  At the second stop position, the supply rod 37 has already advanced and the screw hole 20 of the nut 18 held therein is waiting at a position where it can be concentric with the center of the moving electrode 7 stopped at the second stop position. ing. When the movable electrode 7 on which the steel plate part 8 is placed in such a standby state rotates, the steel plate part 8 stops at the lower side of the nut 18.

  In this state, when compressed air is introduced into the lower air chamber 68 in this state, the guide pin 15 forcibly protrudes and enters the screw hole 20 of the nut 18 as shown by a two-dot chain line in FIG. . When the supply rod 37 is subsequently retracted, the nut 18 is relatively removed from the recess 46 of the supply rod 37, and the nut supply is completed.

  As described above, since the guide pin 15 is forcibly advanced and retracted, the guide rod 37 is allowed to perform only the advance / retreat operation without the elevating operation, and the adoption of the elevating air cylinder 41 as shown in FIG. 3 is stopped. Thus, the structure can be simplified, and the effect of improving the operation reliability can be obtained. Other functions and effects are the same as in the previous example.

  FIG. 7 is a modification of the supply rod 37. A permanent magnet 71 is attached to the inner wall of the holding recess 46 in which the projection nut 18 is accommodated, and the nut 18 is attracted by the permanent magnet 71 and held in the holding recess 46. An air cylinder 73 is attached to the arm member 72 welded to the supply rod 37, and a push plate 74 is fixed to the piston rod of the air cylinder 73. Other configurations are the same as those of the previous examples, and members having the same functions are denoted by the same reference numerals.

  When the moving electrode 7 moves while the supply rod 37 is waiting at the second stop position, the push plate 74 is lowered by the operation of the air cylinder 73 and the nut 18 is resisted against the attractive force of the permanent magnet 71. Is pushed down to match the guide pin 15 directly below. Other functions and effects are the same as in the previous examples.

  FIG. 8 shows still another modified example of the supply rod 37. This pulls the permanent magnet 71 in the longitudinal direction of the supply rod 37 to substantially eliminate the attractive force with respect to the nut 18. Reference numeral 75 is a tow rod coupled to the permanent magnet 71. When the permanent magnet 71 is pulled, the nut 18 falls onto the guide pin 15. Other configurations are the same as those of the previous examples, and members having the same functions are denoted by the same reference numerals. The other effects are the same as in the previous examples.

  FIG. 9 is a side view schematically showing a modified example of nut supply. In (A), the supply rod 37 advances from directly above the moving electrode 7. A pin 76 that enters the screw hole 20 of the nut 18 is provided at the tip of the supply rod 37, and the nut 18 is attracted and held by the permanent magnet 71 in the supply rod 37. Other configurations are the same as those of the previous examples, and members having the same functions are denoted by the same reference numerals.

  When the permanent magnet 71 is pulled up by the pulling rod 75, the nut 18 falls as it is and matches the guide pin 15. Other functions and effects are the same as in the previous examples.

  In the modified example of FIG. 9B, the pin 76 is elongated to serve as a guide rod, and the supply rod 37 is approached obliquely from above. Other configurations are the same as those of the previous examples, and members having the same functions are denoted by the same reference numerals.

  When the attractive magnetic force of the permanent magnet 71 disappears, the nut 18 matches the guide pin 15 while sliding along the guide rod 76. Other functions and effects are the same as in the previous examples.

  FIG. 10 is a cross-sectional view and a plan view showing a modification of the tip portion of the supply rod. The nut 18 is formed with a flange 78, and the holding recess 46 is open on the lower side and the right side as shown in FIG. A holding groove 79 into which the flange 78 enters is formed in the holding recess 46. The open end of the component supply pipe 38 that supplies the nut 18 faces the holding recess 46. Other configurations are the same as those of the previous examples, and members having the same functions are denoted by the same reference numerals.

  When the guide pin 15 of the moving electrode 7 enters the open groove 45 and the screw hole 20, the supply rod 37 is retracted to the left, and the nut is supplied. Other functions and effects are the same as in the previous examples.

  FIG. 11 is a cross-sectional view and a plan view showing another modified example of the tip portion of the supply rod. This is the case where the one in FIG. 10 is reversed. Note that FIG. 11B is a view of FIG. 11A viewed from below.

  This modified example is the same as the modified example of FIG.

  FIG. 12 is a plan view showing a case where two nuts are supplied to the steel plate part 8. The steel plate part 8 has a bifurcated shape having projecting pieces 80, 81, and the movable electrode 7 is disposed below each projecting piece 80, 81. The steel plate component 8 is prevented from shifting by the positioning pins 82. On the other hand, a holding recess 46 as shown in FIG. 11 is formed in the tip member 83 of the supply rod 37 at a position corresponding to the two moving electrodes 7 and 7. Other configurations are the same as those of the previous examples, and members having the same functions are denoted by the same reference numerals.

  Two nuts held by the tip member 83 are placed on the projecting pieces 80 and 81 at a time. Therefore, a plurality of nuts can be supplied onto the steel plate part 8 in a short time, which is effective in improving productivity. Other functions and effects are the same as in the previous examples.

  FIG. 14 is a side view showing a means for confirming the supply of the projection nut. A nut confirmation sensor 85 that detects the presence or absence of the nut 18 is attached to the portion of the supply rod 37 above the holding recess 46. The nut confirmation sensor 85 may be of various types such as an optical detection sensor or an electromagnetic detection sensor. Here, the latter is an electromagnetically operated sensor. This is a commonly used proximity switch.

  When the guide pin 15 is fitted in the screw hole 20 of the nut 18, the nut 85 is present in the magnetic field of the nut confirmation sensor 85, so that the sensor 85 transmits a “nut detection” signal. . Thereafter, when the supply rod 37 moves backward and the nut 18 remains on the steel plate part 8, the sensor 85 converts the signal into a “nut not detected” signal. When such signal conversion is input to the control means 34 shown in FIG. 15, it is determined that the nut 18 is normally present on the steel plate part 8, and the start signal of the welding machine 50 can be transmitted. Become.

  If the nut is not present for any reason, a “nut not detected” signal is transmitted at the position where the supply rod 37 has advanced, so that the control means 34 having received the signal activates the welding machine 50. Works to stop. Other configurations are the same as those of the previous examples, and members having the same functions are denoted by the same reference numerals. The other effects are the same as in the previous examples.

  By associating the signal from the nut confirmation sensor 85 with the signals from the sensors 42 and 43 for detecting the operation of the supply rod 37 under the AND condition, the measure against the abnormality of the device is performed at the stage of the second stop position of the nut supply. As a result, the abnormality can be detected and dealt with early, and the operational reliability of the apparatus can be further improved.

  The index table 1 described above is a rotary type, but it can be advancing and retracting. As shown in FIG. 13, the movable electrodes 7 are arranged on the elongated index table 1 at predetermined equal intervals, and the loading device 27, the clamp device 10, the supply device 36, the welding machine 50, and the clamp device 10 are arranged at positions corresponding thereto. And an unloading device 64 is arranged. When the index table 1 moves to the right side, it receives the operation of each device (27, 10, 36, 50, etc.) arranged on the upper side, and when it moves to the left side, each device arranged on the lower side. (27, 10, 36, 50, etc.).

  Other configurations and operations in the advance / retreat type are the same as those in the above examples.

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

  The steel plate part 8 held by the loading device 27 is placed on the moving electrode 7 stopped at the first stop position. Next, when the index table 1 moves and the movable electrode 7 moves by a predetermined rotation angle, the projection nut 18 is placed on the steel plate part 8 by the supply device 36 at the second stop position. The supply rod 37 of the supply device 36 waits in advance at the second stop position while holding the nut 18. When the movable electrode 7 moves to the second stop position and stops, the projection nut 18 is immediately attached to the steel plate part. 7 is transferred.

  As described above, the movable electrode 7 on which the nut 18 is placed on the steel plate part 8 at the second stop position moves to the third stop position by the rotation of the index table 1, and the movable electrode 54 moves forward. It gets wet.

  The advance operation of the movable electrode 54 is performed by an operation start signal from the control means 34 shown in FIG. As this operation start signal, a signal obtained by at least the operation of the supply device 36 at the second stop position is input to the control means 34, and is thereby transmitted from the control means 34. As described above, the welding machine activation signal (operation start signal) from the control means 34 is obtained by AND-conditioning the signal from the operation of the supply device 36 and the signal from the nut confirmation sensor 85 shown in FIG. It is processed and sent. By doing so, it is possible to detect missing supply of nuts in an early stage, and to prevent defective parts from flowing into the subsequent process.

  As described above, at the second stop position, the supply rod 37 holding the nut 18 is waiting for the arrival of the mobile electrode 7 on which the steel plate part 8 is placed, so that the mobile electrode 7 is at the second stop position. Nuts are supplied at the same time as stopping. Therefore, the nut can be supplied at the same time when the movable electrode 7 arrives at the second stop position, and the operation time of the apparatus can be shortened. In other words, since there is no useless movement in which the supply device 36 starts the supply operation after the movable electrode 7 arrives at the second stop position, it is effective for shortening the time.

  As described above, the advance operation of the movable electrode 54 is executed with the operation of the supply device 36 (supply rod 37) at the second stop position as a trigger. Therefore, the movable electrode 54 can surely advance and complete the welding with respect to the steel plate part 8 and the nut 18 on the moving electrode 7 that is correctly stopped at the third stop position. That is, since the welding operation at the third stop position is performed using the movement of the supply device 36 at the second stop position, the welding operation is reliably achieved depending on the operation at the previous stop position, and the operation as a device is performed. Reliability is improved.

  In addition, the operability of the supply device 36 itself is shortened, and the movement of the supply device 36 is used to start the operation of the movable electrode 54. Therefore, the supply device 36 shortens the operation time of the electric resistance welding device. Therefore, the movable electrode 54 can be accurately operated, and the supply device 36 is substantially multifunctional, which is effective for simplifying the structure.

  Since the nut 18 is held on the supply rod 37 of the supply device 36 and is waiting at the second stop position, the nut 18 can be accurately transferred to a predetermined location. That is, since the nut 18 can be held in the supply device 36 in a half-constrained state, the relative position between the waiting nut 18 and the target supply location can be accurately obtained, and the nut 18 is shifted to a shifted position. There is no such thing as being supplied.

  Each moving electrode 7 is provided with a guide hole 15 that enters the positioning hole 26 formed in the steel plate part 8 and the screw hole 20 of the projection nut 18.

  With the above configuration, when the steel plate part 8 is placed on the moving electrode 7, the guide pin 15 relatively penetrates the prepared hole 26 formed in the steel plate part 8, and the relative position between the steel plate part 8 and the moving electrode 7 is accurate. Can be set. Further, since the guide pin 15 relatively passes through the screw hole 20 of the projection nut 18, the nut 18 can be supplied to the correct position with respect to the moving electrode 7 and the steel plate part 8.

  The base is a rotary index table.

  With the above configuration, since the base is the rotary index table 1, the stop position from the first stop position to the third stop position can be accurately set by rotating the table 1 by a predetermined angle, The intermittent operation as a device can be executed accurately.

  The base is an advancing and retracting index table.

  With the above configuration, since the base is the advancing / retracting type index table 1, the stop position from the first stop position to the third stop position can be accurately set by moving the table 1 by a predetermined rectilinear distance, The intermittent operation as a device can be executed accurately. Further, as shown in FIG. 13, the index table 1 can be reciprocated to increase productivity.

  The projection nut supply means is an advancing / retracting or swinging supply rod.

  With the above configuration, the projection nut 18 can be held on the supply rod 37 and the nut 18 can be made to wait in advance at the second stop position. Since the projection nut 18 is held by the supply rod 37 that moves back and forth or swings in this way, the nut 18 is securely held by the supply rod 37, and the position of the nut 18 during the movement of the supply rod 37 is increased. It is possible to prevent the nut 18 from slipping out or dropping off the nut 18.

  A holding recess 46 of the projection nut 18 is formed at the tip of the supply rod 37, and the supply rod 37 is retracted after the guide pin 15 relatively enters the screw hole 20 of the projection nut 18. It is.

  With the above configuration, when the screw hole 20 of the nut 18 held in the holding recess 46 of the supply rod 37 is coaxial with the guide pin 15 of the moving electrode 7, the supply rod 37 moves in the axial direction of the guide pin 15 and guides. The pin 15 relatively enters the screw hole 20. When the supply rod 37 retreats in the state of entering in this way, the nut 18 remains on the steel plate part 8 while being locked to the guide pin 15. Thus, since the supply rod 37 moves backward with the guide pin 15 entering the screw hole 20 of the nut 18, the steel plate part 8 and the nut 18 are securely placed on the moving electrode 7, and the next step is the first step. The best preparation for the welding at the 3 stop position will be made and a device with high operational reliability will be obtained.

  Advance / retract drive means for advancing / retreating the guide pin 15 is provided.

  As shown in FIG. 5, the guide pin 15 is moved backward from the moving electrode 7 by the advancing / retracting driving means constituted by the cylinder 13 and the piston 14, and the nut 18 held by the supply rod 37 in this state is moved to the moving electrode 7. Then, the guide pin 15 is caused to protrude by the advance / retreat driving means and enter the screw hole 20 of the nut 18. The supply rod 37 is moved backward in such an approach state.

  Therefore, since the supply rod 37 need only move forward and backward, and does not need to form a motion in a direction orthogonal to the forward and backward movement, that is, square motion, the operation of the supply device 36 is simplified, and accordingly the operation of the device 36 is reduced. The operation structure using an air cylinder or the like can be simplified.

  A plurality of the supply devices 36 are arranged.

  Thus, by providing a plurality of supply devices 36, nuts 18 having different dimensions and shapes can be supplied according to changes in the steel plate component 8. That is, even if the type of the steel plate part 8 changes, it is possible to immediately supply the nut 18 suitable for it, so that welding can proceed efficiently without stopping the apparatus. Further, it is possible to hold the plurality of nuts 18 in the supply device 36 and supply them to a plurality of locations of the steel plate component 8 at a time, which is effective for improving the efficiency of the device.

  In the first embodiment, the steel plate part is first placed on the moving electrode, and then the projection nut is placed on the steel plate part.

  In the second embodiment, the above-described placing order is reversed, and the projection nut is first placed on the moving electrode, and then the steel plate component is placed on the projection nut. Although illustration regarding this embodiment is omitted, it can be easily implemented from the embodiment 1.

  That is, a steel plate component and a projection nut are placed on a moving electrode attached to a base that moves at a predetermined movement interval, and the welding current is applied while pressing the steel plate component and the projection nut on the moving electrode with the movable electrode. In a type in which a projection nut is electrically resistance-welded to a steel plate part by energization, a plurality of the moving electrodes are arranged on the base at the same interval as the moving interval, and the base moves at the moving interval, Each moving electrode is configured to take at least a first stop position, a second stop position, and a third stop position, and is projected so as to be placed on the moving electrode stopped at the first stop position. Projection nut supply means for supplying the nut is provided, and the moving electrode stopped at the second stop position is provided with the first stop position. Steel plate component supply means for supplying a steel plate component on the mounted projection nut is provided, and pressurization and welding current are applied to the projection nut and the steel plate component on the moving electrode stopped at the third stop position. A movable electrode is provided, and the steel plate component supply means is configured to wait in advance at the second stop position while holding the steel plate component, and is movable at the third stop position by at least the operation of the steel plate component supply means. The electric resistance welding apparatus is provided with a control means for generating an electrode operation start signal.

  Thus, by placing the projection nut first, it becomes easy to cope with a change in the shape of the steel plate part, and further, it is effective for rationalizing the process according to the shape of the steel plate part. Other functions and effects are the same as those of the first embodiment.

  A steel plate part and a projection nut are placed on a moving electrode attached to a base that moves at a predetermined movement interval. The steel plate part and the projection nut on the moving electrode are pressurized with the movable electrode and a welding current is applied. Then, in an apparatus for welding a projection nut to a steel plate part by electric resistance welding, the nut or the steel plate part supply device is made to wait in advance at a predetermined second stop position, and the welding machine is started using the operation of the supply device. Is doing. Therefore, it can be expected to be used in a wide range of industrial fields such as welding assembly of automobiles and home appliances.

It is a top view which shows the Example of this invention. It is (2)-(2) sectional drawing of FIG. It is a side view of a supply apparatus. It is sectional drawing of a moving electrode. It is sectional drawing of another moving electrode. It is a figure which shows the front-end | tip part of a supply rod. It is a figure which shows the front-end | tip part of another supply rod. It is a figure which shows the front-end | tip part of another supply rod. It is a side view which shows the example of arrangement | positioning of another supply rod. It is a figure which shows the modification of a supply rod front-end | tip part. It is a figure which shows the modification of another supply rod front-end | tip part. It is a figure which shows the modification of other supply rod front-end | tip parts. It is a top view of an advance / retreat type index table. It is a side view of a supply rod equipped with a nut confirmation sensor. It is a block diagram which shows the operation | movement system of an apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Index table 7 Moving electrode 8 Steel plate part 13 Cylinder 14 Piston 15 Guide pin 18 Projection nut 27 Loading device 34 Control means 36 Supply device 37 Supply rod 46 Holding recessed part 50 Welding machine 54 Movable electrode

Claims (9)

A steel plate part and a projection nut are placed on a moving electrode attached to a base that moves at a predetermined movement interval. The steel plate part and the projection nut on the moving electrode are pressurized with the movable electrode and a welding current is applied. In the type where the projection nut is electrically resistance welded to the steel plate part,
A plurality of the moving electrodes are arranged on the base at the same interval as the moving interval, and each moving electrode has at least a first stop position, a second stop position, and a third stop position by moving the base at the movement interval. Is configured to take
Component supply means is provided for supplying steel plate components so as to be placed on the moving electrode stopped at the first stop position;
A projection nut supply means for supplying a projection nut onto the steel plate component placed at the first stop position on the moving electrode stopped at the second stop position;
A movable electrode is provided for applying pressure and welding current to the steel plate part and the projection nut on the moving electrode stopped at the third stop position;
The projection nut supply means is configured to wait in advance at the second stop position while holding the projection nut,
An electric resistance welding apparatus comprising: control means for generating an operation start signal of the movable electrode at the third stop position by at least an operation of the projection nut supply means.   The electric resistance welding apparatus according to claim 1, wherein each moving electrode is provided with a guide hole that enters a positioning hole formed in a steel plate part and a screw hole of a projection nut.   The electric resistance welding apparatus according to claim 1, wherein the base is a rotary index table.   The electric resistance welding apparatus according to claim 1, wherein the base is an advancing and retracting index table.   The electric resistance welding apparatus according to any one of claims 1 to 4, wherein the projection nut supply means is an advancing / retracting or swinging supply rod.   6. The electric resistance according to claim 5, wherein a holding recess for a projection nut is formed at a tip portion of the supply rod, and the supply rod is retracted after the guide pin relatively enters the screw hole of the projection nut. Welding equipment.   The electric resistance welding apparatus according to any one of claims 2 to 6, further comprising an advancing / retreating drive means for advancing and retracting the guide pin.   The electric resistance welding apparatus according to any one of claims 1 to 7, wherein a plurality of the projection nut supply means are arranged. A steel plate part and a projection nut are placed on a moving electrode attached to a base that moves at a predetermined moving interval, and the steel plate part and the projection nut on the moving electrode are pressurized with the movable electrode and a welding current is applied. In the type where the projection nut is electrically resistance welded to the steel plate part,
A plurality of the moving electrodes are arranged on the base at the same interval as the moving interval, and each moving electrode has at least a first stop position, a second stop position, and a third stop position by moving the base at the movement interval. Is configured to take
A projection nut supply means for supplying a projection nut so as to be placed on the moving electrode stopped at the first stop position;
A steel plate component supply means for supplying a steel plate component on the projection nut placed at the first stop position on the moving electrode stopped at the second stop position;
A movable electrode for applying pressure and welding current to the projection nut and the steel plate part on the moving electrode stopped at the third stop position;
The steel plate component supply means is configured to wait in advance at the second stop position while holding the steel plate component,
An electric resistance welding apparatus, comprising a control means for generating an operation start signal of the movable electrode at the third stop position by at least an operation of the steel plate component supply means.

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