JP4501138B2 - Projection welding equipment - Google Patents

Description

  The present invention relates to a projection welding apparatus that automatically supplies parts such as projection bolts and projection nuts to electrodes and moves the electrodes freely to weld these parts to predetermined positions such as steel plate parts.

As a technique for performing spot welding by moving an electrode freely, there is a technique disclosed in JP-A-10-323963. In this technique, electrodes are moved along the X-axis, Y-axis, and Z-axis to weld predetermined portions between steel plate components.
Japanese Patent Laid-Open No. 10-323963 Japanese Patent Laid-Open No. 08-071767

  Although the technique disclosed in Patent Document 1 can accurately move the electrode to a predetermined location along the X, Y, and Z axes, components such as a projection bolt and a projection nut can be used as the electrode. After being held, it is impossible to move the electrode to a predetermined location. In other words, when welding bolts and nuts with welding projections to steel plate parts by projection welding, it is necessary to supply the parts to the electrodes and move the electrodes to a position where they can be welded while holding the parts It becomes. Furthermore, it is necessary that the welding apparatus can be welded even in a narrow place so as not to interfere with a counterpart member such as a steel plate part.

  Furthermore, the technique disclosed in the above-mentioned Patent Document 2 moves the electrode along the X axis, the Y axis, and the Z axis, and holds the projection bolt on this electrode. Since it faces in a certain direction, it is necessary to install a projection bolt supply mechanism suitable for it. For this reason, this supply mechanism becomes complicated, and a problem arises in operational reliability.

  The present invention is provided to meet the above demands and problems, and provides a projection welding apparatus capable of accurately holding a component on an electrode and accurately moving the electrode to a predetermined position. With the goal.

Means to solve the problem

According to the first aspect of the present invention, an electrode rotation unit is formed by combining a rotation base member having a moving electrode and a rotation drive unit that rotates the rotation shaft, and a rotation of the rotation drive unit. The angle is set so that a part from the part supply passage is supplied to the holding portion of the moving electrode, and a welding position where the part is rotated from the supplied position and faces the counterpart member is taken. rotation unit is supported by the rotating mechanism with which is coupled to the moving mechanism and the moving mechanism for moving in the lateral direction and the longitudinal direction changing the direction of the rotary shaft, the moving electrode and the component supply in the supply target position The projection welding apparatus is characterized in that an axis of the passage is coaxial with a rotation axis of the rotating mechanism .

The invention's effect

  An electrode rotating unit formed by coupling a rotating base member having a moving electrode and a rotation driving means for rotating the rotating shaft to the rotating shaft moves in the left-right direction, the front-rear direction, and the rotating direction. The electrode can be accurately reached at a predetermined position, and the part can be correctly welded to a predetermined position of the counterpart member. And since the direction of a rotating shaft can be changed by the said rotation mechanism, a moving electrode can be reached to a narrow location, without making a rotating shaft exist in the direction which a moving electrode advances.

Since the moving electrode is attached to the rotating base member that rotates, the moving electrode is provided with two positions, a supplied position where the component is supplied to the holding portion and a welding position where the component faces the counterpart member. After the component is held by the moving electrode at the supply position, the part is rotated to the welding position by the rotation driving means. In this way, the position to be supplied can be set to the position where the parts are most easily supplied to the moving electrode, and the parts can be supplied reliably. Furthermore, the welding position can be set to a position where welding is most easily performed on the counterpart member, and the welding operation is ensured. And since it is in the coaxial state as described above, even when the electrode rotation unit is moving in the X direction, the Y direction and the rotation direction, the component supply from the component supply passage to the moving electrode Is possible. Therefore, moving the electrode rotating unit to a predetermined position and supplying parts to the moving electrode can be performed simultaneously, which is effective for shortening the welding time.

  Since the welding position of the moving electrode is set according to the rotation angle of the rotating base member, the optimum welding position for the welding operation can be set, and the welding position of the parts can be accurate and good welding quality can be ensured.

  Furthermore, it is desirable that the supplied position is arranged on the opposite side to the advancing direction in which, for example, the moving electrode at the welding position faces the counterpart member. By doing so, since the parts are supplied to the moving electrode at a location separated from the welding position, it is easy to arrange the structures necessary for the supply. As described above, the supply position of the moving electrode is set according to the rotation angle of the rotating base member. Therefore, the optimum component supply position can be set so that the above-mentioned advantages can be obtained, and the component to the moving electrode is smooth and reliable. Effective for supply.

  The invention according to claim 2 is the projection according to claim 1, wherein the moving mechanism is configured such that a lateral movement guide means including a guide rail and a longitudinal movement guide means including a guide rail are crossed at substantially right angles. It is a welding device.

  Since the electrode rotation unit moves in a so-called X direction and Y direction by combining the left and right movement guide means and the front and rear movement guide means in a state of crossing each other at substantially right angles, the moving electrode is moved to a predetermined welding position. Can be freely reached.

  A third aspect of the present invention is the projection welding apparatus according to the first or second aspect, wherein the rotating mechanism is configured by combining the outer cylinder shaft with the inner cylinder shaft being rotatable.

  Since this rotating mechanism is configured by combining the outer cylindrical shaft on the outside of the cylindrical inner cylindrical shaft, the diameter of the shaft can be set large. For this reason, the rotation center is formed with a shaft structure that is less likely to be misaligned and has high support stability and shaft rigidity, so that the rotation locus of the electrode rotation unit becomes a predetermined locus, and the movement and arrival location of the moving electrode is accurate. Is required. Furthermore, since it has a cylindrical shaft structure, various conducting wires, component supply hoses, cooling water hoses, etc. for the electrode rotation unit can be arranged inside the cylinder, avoiding these damages and making the welding apparatus compact. It becomes possible to do.

  Furthermore, the relative position between the component supply pipe and the moving electrode is set by making the central axis of the component supply pipe to which the component supply hose is connected and the movable electrode at the supply position coaxial with the rotation axis of the rotation mechanism. They can always be matched, and the parts are supplied to the moving electrode accurately. By always keeping the coaxial state as described above, it is not necessary to provide a special centering structure in the operating mechanism, which is effective in terms of simplification of the structure.

According to a fourth aspect of the present invention, there is provided an advancing / retreating drive means for causing the movable electrode to reach the counterpart member from a welding position facing the counterpart member between the rotating mechanism and the electrode rotating unit. Item 4. The projection welding apparatus according to any one of Item 3.

  The moving electrode moved in the left-right direction, the front-rear direction, and the rotation direction by the advance / retreat driving means advances toward the counterpart member in a state where the parts held there are opposed to the counterpart member. And reliable parts welding is realized. That is, since the moving electrode moves in three directions, that is, the X direction that is the left-right direction, the Y direction that is the front-rear direction, and the Z direction that faces the counterpart member, reliable component welding is realized at a predetermined location. .

  The invention according to claim 5 is the projection welding apparatus according to any one of claims 2 to 4, wherein a support base member is attached to the longitudinal movement guide means, and the rotating mechanism is attached to the support base member. It is.

  The support base member is moved in the left-right direction and the front-rear direction, and a rotation mechanism including an inner cylinder shaft and an outer cylinder shaft is attached to the support base member. In other words, since the rotation mechanism is attached to the longitudinal movement guide means via the support base member, it is possible to improve the mounting rigidity of the rotation mechanism with respect to the longitudinal movement guide means. At the same time, the mounting structure of the rotation mechanism is simplified. Further, by attaching a rotation drive source such as an electric motor to the support base member, it becomes easier to input a rotational force to the rotation mechanism.

  A sixth aspect of the present invention is the projection welding apparatus according to any one of the third to fifth aspects, wherein an electrode rotation unit is attached to the outer cylinder shaft via the advance / retreat driving means.

  Thus, since the advance / retreat driving means is arranged between the outer cylinder shaft and the electrode rotation unit, the advance / retreat drive means can be easily arranged.

A seventh aspect of the present invention is the projection welding apparatus according to any one of the first to sixth aspects, wherein the component supply passage is constituted by a component supply pipe coaxial with the rotation axis .

  Since it is in the coaxial state as described above, even when the electrode rotation unit is moving in the X direction, Y direction and rotation direction, it is possible to supply components from the component supply passage to the moving electrode. It becomes. Therefore, moving the electrode rotating unit to a predetermined position and supplying parts to the moving electrode can be performed simultaneously, which is effective for shortening the welding time.

  The invention according to claim 8 is the projection according to any one of claims 1 to 7, wherein temporary locking means for temporarily locking the component is disposed between the component supply passage and the holding portion. It is a welding device.

  In general, since the parts moving in the parts supply passage are conveyed by compressed air, the conveyance speed becomes high. If the component collides with the holding portion of the moving electrode at such a speed, the durability of the holding portion may be reduced. In the present invention, as described above, since the component is temporarily locked and then transferred to the holding portion, the impact of the component on the holding portion is mitigated, and the holding function of the holding portion can be maintained over a long period of time.

On the opposite side of the rotational axis before Symbol rotating base member and the moving electrode, the welding apparatus that has interference avoidance space is provided in order not to interfere with the mating member.

  Since the interference avoidance space is provided, even if there is a shape part standing on the counterpart member, the moving electrode can be brought close to the standing shape part and welded, and the weldable area of the part is expanded. . That is, since the rotating shaft and the related structure do not exist in the interference avoidance space, the moving electrode can be brought close to the upright portion.

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

  1 to 5 show a first embodiment.

  FIG. 1 is a longitudinal front view of the apparatus, and FIG. 2 is a partial side view of the apparatus of FIG. 1 viewed from the right side. As parts to be welded by this welding apparatus, there are various parts such as projection nuts, projection bolts, and other parts having welding projections. In this embodiment, the projection bolt shown in FIG. 3B is a part to be welded, and is welded to a steel plate part. In the following description, the projection bolt may be simply expressed as a bolt.

  3B, an iron projection bolt 1 includes a shaft portion 2 provided with a male screw, a flange portion 3 integral with the shaft portion 2, and a welding protrusion provided on a flange surface opposite to the shaft portion 2. It is composed of four. Then, as shown in FIG. 4, the bolt 1 is welded to the steel plate part 5, and the blackened portion is the melting part 6.

  The whole welding apparatus shown in FIGS. 1 and 2 is denoted by reference numeral 7. The welding apparatus 7 includes a moving mechanism 8 that mainly moves in the left-right direction that is the X direction and the front-rear direction that is the Y direction, a rotating mechanism 9 that is coupled to the moving mechanism 8, and the rotating mechanism 9. The electrode rotation unit 10 is configured.

  The moving mechanism 8 will be described.

  The moving mechanism 8 is configured in such a manner that a left / right movement guide means 11 for obtaining a forward / backward movement in the X direction and a front / rear movement guide means 12 for obtaining a forward / backward movement in the Y direction are crossed at right angles.

  The left-right motion guide means 11 will be described. Two guide rails 13 arranged in parallel in the left-right direction of FIG. 1, that is, in a direction perpendicular to the paper surface of FIG. 2, are fixed to a stationary member 14 such as a machine frame. At least two of each are attached. The screw shaft 17 is rotated by an electric motor 16 fixed to the bridging member 19 of the guide rail 13. The screw shaft 17 is disposed in the longitudinal direction of the guide rail 13, and a bearing member 18 that rotatably supports the screw shaft 17 is fixed to the bridging member 20 of the guide rail 13 by welding or the like. The slide bearing 15 advances and retreats along the guide rail 13 and suspends the guide rail 21 of the longitudinal movement guide means 12.

  The longitudinal direction of the guide rail 13 and the axial direction of the screw shaft 17 are the X direction.

  The back-and-forth movement guide means 12 will be described. Two guide rails 21 arranged in parallel to the paper surface in FIG. 1, that is, in the left-right direction in FIG. 2, are suspended by the slide bearing 15. At least two slide bearings 22 are attached to the lower portion of each guide rail 21. The screw shaft 25 is rotated by an electric motor 24 fixed to the bridging member 23 of the guide rail 21. The screw shaft 25 is disposed in the longitudinal direction of the guide rail 21, and a bearing member 26 that rotatably supports the screw shaft 25 is fixed to the bridging member 27 of the guide rail 21 by welding or the like. The slide bearing 22 advances and retreats along the guide rail 21 and suspends a support base member 28 described later.

  The longitudinal direction of the above-described guide rail 21 and the axial direction of the screw shaft 25 are the Y direction.

  The screw shaft 17 passes through the transmission member 30 fixed by welding or the like to the bridging member 29 on the side of the longitudinal movement guide means 12, and when the screw shaft 17 rotates, the longitudinal movement guide means 12 is transmitted via the transmission member 30. Moves forward and backward in the X direction.

  Further, the screw shaft 25 passes through the transmission member 31 fixed to the support base member 28 by welding or the like. When the screw shaft 25 rotates, the support base member 28 advances and retreats in the Y direction via the transmission member 31. To do.

  In the moving mechanism 8 described above, the lateral movement guide means 11 for obtaining the forward / backward movement in the X direction and the forward / backward movement guide means 12 for obtaining the forward / backward movement in the Y direction are crossed at a right angle. It is generally used in practice.

  Next, the rotation mechanism 9 will be described.

  The rotating mechanism 9 has a hollow inner cylinder shaft 33 with a circular cross section fixed to the support base member 28, and an outer cylinder shaft 35 with a circular cross section is combined with the outer side via a bearing 34 in a rotatable state. A male screw 36 is formed on the upper portion of the inner cylinder shaft 33, and the male screw 36 is screwed into a ring-shaped nut member 37 fixed to the support base member 28 with a bolt or the like. Reference numeral 32 denotes a lock nut for the nut member 37. Also, the lock nut 38 is fastened to the bearing 34 at two locations, upper and lower.

  In order to apply a rotational force to the outer cylinder shaft 35, an electric motor 39 is used. The electric motor 39 is fixed to the lower side of the support base member 28 using an attachment piece 40. A pinion 41 rotated by the electric motor 39 meshes with a ring gear 42 fixed to the outer cylinder shaft 35. A step motor is employed as the electric motor 39, and the pinion 41 is rotated at a predetermined rotational speed by pulse input, and the ring gear 42 is rotated at a predetermined angle. As a result, the outer cylinder shaft 35 is also rotated by a predetermined angle, and the rotation angle of the electrode rotation unit 10 is set. The outer cylinder shaft 35 can be rotated instead of the step motor. For example, an advancing / retracting rack can be engaged with the ring gear 42.

  The internal space of the inner cylinder shaft 33 communicates with a through hole 43 provided in the support base member 28.

  A support member 45 is fixed to the lower end portion of the inner cylinder shaft 33 with a fixing bolt 46. A component supply pipe 47 that forms a component supply passage is attached to the support member 45. The component supply pipe 47 has a circular cross section, and its axis is coaxial with the rotation axis O of the inner cylinder shaft 33. A component supply hose 48 is joined to the component supply pipe 47, and its end is connected to a parts feeder 49. The component supply hose 48 is made of a flexible synthetic resin such as urethane resin or vinyl chloride.

  The rotation axis O is set in a direction orthogonal to the X direction and the Y direction. The rotation axis O forms a Z direction with respect to the X direction and the Y direction.

  The parts feeder 49 may be one that feeds from a transfer path of a vibrating bowl, one that attracts a predetermined number of parts with a magnet attached to a rotating plate, and sends it out from the feeding passage, or a conveying path that uses a rotating disc. Various components can be employed such as moving the component to a position where the component is sent out from the transfer passage. In this embodiment, the type of feeding from the transfer path of the vibrating bowl is adopted. An air injection pipe 44 for injecting compressed air into the parts supply hose 48 is connected to the parts delivery pipe of the parts feeder 49.

  A component supply hose 48, a conductive wire described later, a cooling water hose, and the like pass through the inner cylinder shaft 33 and the through hole 43.

  Next, the electrode rotation unit 10 will be described.

  The outer cylinder shaft 35 is provided with a mounting member 50 formed so as to protrude in the diameter direction, and an air cylinder 51 as a forward / backward driving means is fixed thereto with a bolt or the like. The air cylinder 51 is arranged so that the forward / backward direction of the piston rod 52 is parallel to the rotation axis O.

  A plate-like base member 53 is coupled to the lower end portion of the piston rod 52. A cylindrical bearing 54 is fixed to the base member 53, and a rotating shaft 55 is supported in a rotatable state there. The axis of the rotation shaft 55 is orthogonal to the rotation axis O. A rotation driving means 56 is fixed to the base member 53, and its output shaft is coupled to the end of the rotation shaft 55 so that the rotation shaft 55 is rotated by a predetermined angle such as 90 degrees, 120 degrees, and 180 degrees. Yes.

  As the rotation driving means 56, a step motor is employed that obtains a rotational displacement of a predetermined angle by pulse input. This step motor is a general one, but it is also possible to use an air motor having a rotary vane instead. In this air motor, a vane is provided on a shaft passing through a rotating cylinder, and an air pressure is applied to the vane to obtain a rotational displacement. This is also a rotation driving means that is generally employed.

  A rotating base member 57 formed of a thick plate member is coupled to the other end portion of the rotating shaft 55, and a moving electrode 58 is attached to the rotating base member 57. Four moving electrodes 58 are attached at intervals of 90 degrees, and the length of each moving electrode 58 is set so that the tip of each moving electrode 58 is located on a virtual circle concentric with the rotation shaft 55. (See FIG. 6). As described above, since the four moving electrodes 58 are provided at intervals of 90 degrees, the rotation driving means 56 is rotationally displaced by 90 degrees.

  As shown in FIG. 3B, the holding portion indicated by reference numeral 60 is formed on the moving electrode 58. This holding part 60 may be any means as long as it can hold the shaft part 2 of the bolt 1, and can be realized in various forms such as one that clamps the shaft part 2 with a clamp leaf spring and one that holds the shaft part 2 in the accommodation hole. can do. In this embodiment, the latter format is adopted.

  That is, the receiving hole 61 of the shaft portion 2 is formed in the central portion of the moving electrode 58, and the permanent magnet 62 is fixed to the inner portion thereof. The axis of the receiving hole 61 is coaxial with the rotational axis O. Therefore, the component supply pipe 47 and the moving electrode 58, that is, the receiving hole 61 are arranged coaxially at the “supplied position” described later.

  As shown in FIG. 3B, the state where the holding portion 60 (receiving hole 61) of one moving electrode 58 is coaxial with the component supply pipe 47 constituting the component supply passage is the "supplied position". is there. When one moving electrode 58 is in the supply position in this way, as shown in FIG. 1, the bolt 1 is held by the holding portion 60 of the other moving electrode 58 and faces the steel plate component 5 which is the counterpart member. This state is the “welding position”. Note that the number of moving electrodes 58 can be one, and the number of moving electrodes 58 can be two or three. In such a case, the operating angle of the rotation driving means is set to 180 degrees and 120 degrees, respectively.

  The supplied position is arranged on the side opposite to the advancing direction in which the moving electrode 58 at the welding position faces the steel plate part 5. By doing so, the bolt 1 is supplied to the moving electrode 58 at a location separated from the welding position, so that it becomes easy to arrange structures and the like necessary for supply.

  As shown in FIG. 1, in order to energize the moving electrode 58 with a welding current, a contactor 64 that is pressed against the cylindrical surface 63 of the rotating shaft 55 is disposed. The contactor 64 is composed of a block member having an arc surface that is in close contact with the cylindrical surface 63, and is connected with a conducting wire 65 extending from a welding transformer (not shown). The conductive wire 65 is joined to the contactor 64 through the inner cylindrical shaft 33 and the through hole 43 as described above.

  And since the contactor 64 closely_contact | adheres to the cylindrical surface 63 when supplying a welding current, it is couple | bonded with the piston rod 67 of the air cylinder 66 for that purpose. The contactor 64 is pressed against the cylindrical surface 63 by the advancing operation of the air cylinder 66 during energization. Further, when the rotary shaft 55 rotates, the air cylinder 66 is retracted so that it is not energized away from the cylindrical surface 63. The air cylinder 66 is fixed to the air cylinder 51.

  A plurality of air intake / exhaust hoses (not shown) joined to the air cylinders 51 and 66 are piped from an air distribution unit 68 attached to the outer cylinder shaft 35. Since the air cylinders 51 and 66, the air distribution unit 68, and the like are attached to the outer cylinder shaft 35, the relative positions of the air cylinders 51 and 66 and the air distribution unit 68 do not change even when the outer cylinder shaft 35 rotates. The air intake / exhaust hose does not expand and contract, and the durability of the hose is improved.

  As shown in FIG. 1, the cooling water sent by the cooling water hose 81 cools the moving electrode 58 from the bearing 54 through the inside of the rotating shaft 55 and the rotating base member 57. The cooling water hose 81 is connected to the bearing 54 through the inner cylinder shaft 33 and the through hole 43.

  Next, temporary locking means for the bolt 1 will be described.

  When the bolt 1 that has been conveyed at high speed directly enters the receiving hole 61, there is a risk of damage to the opening edge of the receiving hole 61, for example, wear that proceeds rapidly. In order to avoid such a phenomenon, temporary locking means 70 for temporarily locking the bolt 1 is provided as shown in FIG. The temporary locking means 70 may be anything that temporarily stops the bolt 1 that has been transported and then moves it slowly, and has a member that performs a stop function and a structure that allows it to be moved again.

  In this embodiment, a stop function is once given to the pair of opening / closing members. The two open / close members 71A and 71B once fulfill a stop function in a state where they match. A bottomed tapered hole 72 is formed in a state where the opening and closing members 71A and 71B are closed, and an insertion hole 73 of the shaft portion 2 is formed in the bottom members 72A and 72B. The insertion hole 73 and the taper hole 72 are coaxial with the rotation axis O.

  As shown in FIG. 3A, piston rods 75A and 75B of air cylinders 74A and 74B are coupled to both opening and closing members 71A and 71B. Both air cylinders 74A and 74B are fixed on the support plate 76 so as to face each other. Therefore, when the air cylinders 74A and 74B advance and retract, both the opening and closing members 71A and 71B open and close in a symmetric state.

  A bracket 77 is fixed to the support plate 76. A piston rod 79 of an air cylinder 78 fixed to the support member 45 is coupled to the bracket 77. The forward / backward direction of the piston rod 79 is parallel to the rotation axis O.

  Therefore, the bolt 1 that has been conveyed has its flange portion 3 received by the bottom members 72A and 72B of the taper hole 72 at the same time as the shaft portion 2 passes through the insertion hole 73, thereby performing a stopper function. In this state, the shaft portion 2 is coaxial with the rotation axis O. Then, when the entire temporary locking means 70 is lowered along the rotation axis O by the operation of the air cylinder 78, the distal end portion of the shaft portion 2 is inserted into the receiving hole 61. Thereafter, when the opening and closing members 71A, 71B are retracted and opened on both sides by the operation of the air cylinders 74A, 74B, the flange portion 3 passes through the bottom portion of the tapered hole 72, and the shaft portion 2 enters the inside of the receiving hole 61. 62 is aspirated. In this way, the bolt is held on the moving electrode 58.

  As described above, the bolt 1 that is temporarily locked in the tapered hole 72 in the coaxial state with the rotation axis O is inserted into the receiving hole 61 by the operation of the air cylinder 78, so that the bolt 1 is securely inserted into the receiving hole 61. Thus, there is an effect that the bolt is reliably supplied to the moving electrode 58.

  The opening / closing members 71 </ b> A and 71 </ b> B wait for the arrival of the next bolt 1 by performing an operation opposite to the above-described operation.

  Next, the interference avoidance space will be described.

  As shown in FIGS. 1 and 5, an interference avoidance space 82 is provided at a position below the temporary locking means 70 on the right side of the rotation base member 57 and the moving electrode 58. In other words, the interference avoidance space for preventing the lower part of the welding device, that is, the temporary locking means 70 from interfering with the steel plate part 5 on the opposite side of the rotary base member 57 and the rotary electrode 55 of the moving electrode 58. 82 is provided.

  There are various shapes of the steel plate part 5. As an example, as shown in FIG. 5, there is one having a raised portion 5A and a standing wall 5B. As shown in FIG. 5, the rotating base member 57 and the moving electrode 58 approach to the vicinity of the upright wall 5B, and the bolt 1 is welded between the upright wall 5B and the raised portion 5A. Therefore, by securing the interference avoidance space 82, it is possible to perform bolt welding to a narrow portion.

  1, 4, and 5, reference numeral 59 denotes a back bar for energization, on which a support piece 69 of the steel plate part 5 is fixed.

  Each of the air cylinders 51, 66, 74A, 74B, and 78 can be replaced with an electric motor that outputs and retreats.

  The operation of the above embodiment will be described.

  The bolt 1 that has been conveyed in the component supply hose 48 by compressed air from the parts feeder 49 passes through the component supply pipe 47 and is received in the tapered hole 72 of the temporary locking means 70, where it is temporarily locked. Thereafter, the shaft portion 2 is inserted into the receiving hole 61 as described above.

  When the bolt 1 is held on the moving electrode 58 in this way, the rotating base member 57 is rotated 90 degrees by the rotation driving means 56 and the moving electrode 58 on which the bolt 1 is already held is stopped at the welding position. To do.

  Subsequently, the movable electrode 58 at the welding position of the electrode rotation unit 10 is moved in the left-right direction by the operation of the electric motor 16 of the left-right movement guide unit 11, the electric motor 24 of the front-rear movement guide unit 12, the electric motor 39 of the rotation mechanism 9. A predetermined position is reached by the X direction, the Y direction, which is the front-rear direction, and the rotational movement about the rotation axis O of the rotation mechanism 9.

  Then, the air cylinder 51 is operated to move the moving electrode 58 in the Z direction, and the welding protrusion 4 of the bolt 1 held therein is pressed against the steel plate part 5. Subsequently, a welding current is energized from the contactor 64, and the welding protrusion 4 is welded to the steel plate part 5. When the moving electrode 58 is pulled up by the air cylinder 51 after this welding, the bolt 1 is integrated with the steel plate part 5 and remains there, and the welding is completed.

  Note that the operation sequence described above may be changed so that the moving electrode 58 is moved to a predetermined position and then the bolt 1 is supplied into the receiving hole 61, and then the moving electrode 58 is advanced by the air cylinder 51. Is possible.

  Further, in order to perform the above-described operations in order, the sequence control device generally employed is used to individually control each electric motor, air switching control valve to each air cylinder, and energization of welding current. It is made to operate.

  The functions and effects of the embodiment described above are listed as follows.

  An electrode rotation unit 10 formed by coupling a rotation base member 57 provided with a moving electrode 58 and a rotation drive means 56 for rotating the rotation shaft 55 to the rotation shaft 55 includes a left-right direction, a front-rear direction, and a rotation direction. Therefore, the movable electrode 58 can be accurately reached at a predetermined position, and the bolt 1 can be correctly welded to a predetermined portion of the steel plate part 5. And since the direction of the rotating shaft 55 is changed by the said rotation mechanism 9, the moving electrode 58 can be reached to a narrow location, without making the rotating shaft 55 exist in the direction which the moving electrode 58 advances.

A moving electrode 58 is attached to a rotating base member 57 that performs a rotating operation. The moving electrode 58 has a supply position where the bolt 1 is supplied to the holding unit 60 and a welding position where the bolt 1 faces the steel plate part 5. Since the two positions are given, the bolt 1 is held by the moving electrode 58 at the supplied position, and then rotated to the welding position by the rotation driving means 56. In this way, the supply position can be set to the position where the bolt supply to the moving electrode 58 is most easily performed, and this bolt supply can be performed reliably. Furthermore, the welding position can be set to a position where welding is most easily performed on the steel plate part 5, and the welding operation is ensured. Since it is in the coaxial state as described above, even if the electrode rotation unit 10 is moving in the X direction, the Y direction, and the rotation direction, the component supply pipe 47 moves to the moving electrode 58. Parts can be supplied. Therefore, the electrode rotating unit 10 can be moved to a predetermined position and the parts can be supplied to the moving electrode 58 at the same time, which is effective for shortening the welding time.

  Since the welding position of the moving electrode 58 is set according to the rotation angle of the rotary base member 57, the optimum welding position for the welding operation can be set, and the welding position of the bolt 1 is accurate and good welding quality can be secured.

  Furthermore, it is desirable that the supply position is arranged on the side opposite to the advancing direction in which the moving electrode 58 at the welding position is directed toward the steel plate part 5, for example. By doing so, the bolt 1 is supplied to the moving electrode 58 at a location separated from the welding position, so that it becomes easy to arrange structures and the like necessary for supply. As described above, since the supply position of the moving electrode 58 is set according to the rotation angle of the rotary base member 57, an optimal component supply position that can obtain the above-described advantages can be set, and the smooth and reliable moving electrode 58 can be set. It is effective for supplying bolts.

  The moving mechanism 58 is configured by crossing the left and right motion guide means 11 including the guide rail 13 and the front and rear motion guide means 12 including the guide rail 21 at substantially right angles.

  The electrode rotation unit 10 moves in the so-called X direction and Y direction by combining the left and right motion guide means 11 and the front and rear motion guide means 12 in a state of crossing each other at substantially right angles. It is possible to freely reach a predetermined welding position.

  The rotating mechanism 9 is configured by combining the outer cylinder shaft 35 with the inner cylinder shaft 33 in a rotatable state.

  Since the rotating mechanism 9 is configured by combining the outer cylindrical shaft 35 on the outside of the cylindrical inner cylindrical shaft 33, the diameter of the shaft can be set large. For this reason, the rotation mechanism 9 is formed with a shaft structure that is less likely to be misaligned and has high support stability and shaft rigidity, so that the rotation locus of the electrode rotation unit 10 becomes a predetermined locus, and the movement and arrival of the movable electrode 58 are achieved. The location is accurately determined. Furthermore, since it has a cylindrical shaft structure, various conductive lines 65, component supply hoses 48, cooling water hoses 81, etc. for the electrode rotation unit 10 can be arranged inside the cylinder, and these damages are avoided and welded. The apparatus 7 can be made compact.

  Further, the component supply pipe 47 connected to the component supply hose 48 and the central axis of the movable electrode 58 at the supply position are made coaxial with the rotation axis O of the rotation mechanism 9 to move the component supply pipe 47 and the supply axis. The relative position with respect to the electrode 58 can always be matched, and the bolt supply to the moving electrode 58 is accurately performed. By always keeping the coaxial state as described above, it is not necessary to provide a special centering structure in the operating mechanism, which is effective in terms of simplification of the structure.

  An air cylinder 51 is disposed between the rotating mechanism 9 and the electrode rotating unit 10 to allow the moving electrode 58 placed at the welding position to reach the steel plate part 5.

  The moving electrode 58 moved in the left-right direction, the front-rear direction, and the rotation direction by the air cylinder 51 advances toward the steel plate part 5 with the bolt 1 held there facing the steel plate part 5. Reliable bolt welding is realized for these locations. That is, since the moving electrode 58 moves in three directions, that is, the X direction that is the left and right direction, the Y direction that is the front and rear direction, and the Z direction that faces the steel plate part 5, reliable bolt welding is performed on a predetermined portion. Realize.

  A support base member 28 is attached to the longitudinal movement guide means 12, and the rotation mechanism 9 is attached to the support base member 28.

  The support base member 28 is in a state of moving in the left-right direction and the front-rear direction, and the rotation mechanism 9 including the inner cylinder shaft 33 and the outer cylinder shaft 35 is attached to the support base member 28. In other words, since the rotation mechanism 9 is attached to the longitudinal movement guide means 12 via the support base member 28, the mounting rigidity of the rotation mechanism 9 with respect to the longitudinal movement guide means 12 can be improved. At the same time, the mounting structure of the rotation mechanism 9 is simplified. Further, by attaching a rotational drive source such as the electric motor 39 to the support base member 28, it becomes easy to input the rotational force to the rotation mechanism 9.

  The electrode rotation unit 10 is attached to the outer cylinder shaft 35 via the air cylinder 51.

  Thus, since the air cylinder 51 is disposed between the outer cylinder shaft 35 and the electrode rotation unit 10, the air cylinder 51 can be easily disposed.

  The axes of the moving electrode 58 and the component supply pipe 47 at the supplied position are coaxial with the rotation axis O of the rotation mechanism 9.

  Since it is in the coaxial state as described above, even when the electrode rotation unit 10 is moving in the X direction, the Y direction, and the rotation direction, the bolt from the component supply pipe 47 to the moving electrode 58 Supply becomes possible. Therefore, moving the electrode rotating unit 10 to a predetermined position and supplying the bolt to the moving electrode 58 can be executed simultaneously, which is effective for shortening the welding time.

  Temporary locking means 70 for temporarily locking the bolt 1 is disposed between the component supply pipe 47 and the holding portion 60.

  In general, since the parts moving in the parts supply passage are conveyed by compressed air, the conveyance speed becomes high. If the bolt 1 collides with the holding portion 60 of the moving electrode 58 at such a speed, the durability of the receiving hole 61 may be reduced. As described above, since the bolt 1 is temporarily locked by the tapered hole 72 and then transferred to the receiving hole 61, the impact of the bolt 1 on the receiving hole 61 is reduced, and the holding function of the receiving hole 61 is improved. Can be maintained for a long time.

  An interference avoidance space 82 for preventing the temporary locking means 70 of the welding apparatus 7 from interfering with the steel plate part 5 is provided on the opposite side of the rotating base member 57 and the moving electrode 58 from the rotating shaft 55. .

  Since the interference avoidance space 82 is provided, the moving electrode 58 can be brought close to the raised shape portion 5B and welded even if there is the raised shape portion 5B on the steel plate part 5, and the bolt 1 is welded. The possible area expands. That is, since the rotating shaft 55 and the related structure do not exist in the interference avoidance space 82, the moving electrode 58 can be brought close to the upright portion 5B.

  A component supply pipe 47 and an air cylinder 78 are attached to a support member 45 fixed to the inner cylinder shaft 33, and a temporary locking means 70 is supported by a piston rod 79 of the air cylinder 78. Therefore, since the component supply pipe 47 and the temporary locking means 70 are integrated with the support member 45 as a base member, the axial alignment between the tapered hole 72 of the temporary locking means 70 and the component supply pipe 47 is accurate and easy. Can be done.

  Since the outer cylinder shaft 35 is rotated by the electric motor 39 fixed to the lower side of the support base member 28, the electric motor 39 is accommodated between the support base member 28 and the rotation mechanism 9, and the rotation of the outer cylinder shaft 35 is performed. The drive structure is compact.

  6 and 7 show a second embodiment.

  In this embodiment, a projection nut is welded instead of the projection bolt in the above embodiment. Therefore, only the points different from the previous embodiment will be described here. Further, the projection nut may be simply expressed as a nut.

  The projection nut 84 is made of iron, has a square shape when viewed from the axial direction of the screw hole, and welding projections 83 project from the four corners.

  As shown in FIG. 6, three of the four moving electrodes 58 provided at intervals of 90 degrees hold the projection bolt 1 described above, and the other one holds the projection nut 84. The bolt 1 is supplied from the upper side as described above, while the nut 84 is supplied from the side.

  The moving electrode 58 that holds the nut 84 is provided with a positioning pin 85 at the center of the tip surface thereof, and a permanent magnet 86 is embedded in the vicinity thereof. FIG. 7 is a view showing a supply structure of the nut 84. As shown in FIG. 3A, the supply rod 88 is advanced and retracted by an air cylinder 87, and a holding head 89 is coupled to the tip thereof. A concave portion 90 for receiving the nut 84 is formed in the holding head 89, and positioning surfaces 90A, 90B, and 90C are provided in order to determine the holding position of the nut 84. And as shown to a figure (C), the three sides of the recessed part 90 are the open states. A permanent magnet 91 is attached to the holding head 89 so that the nut 84 in the recess 90 is attracted to the positioning surfaces 90A, 90B, 90C.

  In this embodiment, the holding portion 60 of the moving electrode 58 is constituted by a tip surface of the moving electrode 58, a positioning pin 85, and a permanent magnet 86.

  The holding head 89 performs a square motion indicated by reference numeral 92. For this purpose, a piston rod 94 of another air cylinder 93 is coupled to the air cylinder 87. The advancing and retreating direction of the holding head 89 is orthogonal to the axis of the moving electrode 58 (rotating axis O), and the advancing and retracting direction of the air cylinder 93 is parallel to the axis of the moving electrode 58 (rotating axis O).

  As shown in FIG. (B), the tip of the component supply pipe 95 extending from the parts feeder (not shown) matches the concave portion 90 of the most retracted holding head 89, and the component supply pipe 95 Is supplied to the recess 90.

  In FIG. 7A, the air cylinders 87 and 93 are in the most retracted position. At this time, the opening portion of the component supply pipe 95 matches the concave portion 90, and the transferred nut 84 is temporarily locked in the concave portion 90. Has been. The nut 84 that has been transferred at high speed is received by the positioning surface 90A, and the impact is mitigated. Thereafter, the holding head 89 is advanced by the air cylinder 87, and the advancement of the holding head 89 is stopped at a position where the screw hole of the nut 84 is coaxial with the positioning pin 85 as shown by a two-dot chain line. Then, the holding head 89 moves toward the moving electrode 58 by the operation of the air cylinder 93, and the positioning pin 85 relatively enters the screw hole. From this state, the holding head 89 moves backward to the left, and the nut 84 is held at the tip of the moving electrode 58 by the permanent magnet 86. In this way, a square motion indicated by reference numeral 92 is performed.

  Thereafter, the rotating shaft 55 rotates 90 degrees and the moving electrode 58 holding the nut 84 is placed at the welding position. Subsequently, the air cylinder 51 is operated, the welding projection 83 of the nut 84 is pressed against the steel plate part 5, the welding current is energized, and the nut welding is completed.

  As described above, a plurality of moving electrodes 58 can be arranged, and each moving electrode 58 can hold the bolt 1 or hold the nut 84. Accordingly, a plurality of types of parts can be welded in one welding apparatus, and the functions of the apparatus can be diversified, which is effective in improving productivity.

  As described above, according to the present invention, the electrode rotating unit is moved in the X direction, the Y direction, and the rotating direction, and the supplied moving electrode is moved from the supplied position to the welding position. To work. Therefore, the supply of parts to the moving electrode and the welding operation are surely executed, and it can be widely used in the welding assembly process of automobile bodies and the steel plate welding process of home appliances.

It is a vertical front view of the whole apparatus. FIG. 3 is a partial side view of the device. It is the top view and sectional drawing of a temporary latching means. It is a vertical front view which shows the welding state to steel plate components. It is a vertical front view which shows the welding state to steel plate components. It is a side view which shows the arrangement | positioning state of a movement electrode. It is sectional drawing and a perspective view which show the supply mechanism of a nut.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Projection bolt 2 Shaft part 3 Flange part 5 Steel plate part 7 Welding device 8 Movement mechanism 9 Rotation mechanism 10 Electrode rotation unit 11 Left-right movement guide means 12 Front-rear movement guide means 13 Guide rail 21 Guide rail 33 Inner cylinder axis 35 Outer cylinder axis 47 Component supply pipe 48 Component supply hose O Rotating axis 55 Rotating shaft 56 Rotating drive means 57 Rotating base member 58 Moving electrode 60 Holding part 70 Temporary locking means 82 Interference avoidance space 84 Projection nut

Claims (8)

The electrode rotation unit is formed by coupling a rotation base member having a moving electrode and a rotation drive means for rotating the rotation shaft to a rotation shaft, and the rotation angle of the rotation drive means is determined from the component supply passage. The supply position where the component is supplied to the holding part of the moving electrode and the welding position where the component rotates from the supply position and faces the counterpart member are set. A moving mechanism that moves in a direction and a rotating mechanism that is coupled to the moving mechanism and changes the direction of the rotating shaft, and is supported by the moving electrode at the supply position and the axis of the component supply passage. A projection welding apparatus characterized in that it is coaxial with the rotation axis .   2. The projection welding apparatus according to claim 1, wherein the moving mechanism is configured such that a lateral movement guide means including a guide rail and a longitudinal movement guide means including a guide rail cross each other at a substantially right angle.   The projection welding apparatus according to claim 1, wherein the rotation mechanism is configured by combining an outer cylinder shaft in a rotatable state with the inner cylinder shaft. The advancing / retreating drive means for causing the moving electrode to reach the counterpart member from a welding position facing the counterpart member is disposed between the rotation mechanism and the electrode rotation unit. Projection welding equipment.   The projection welding apparatus according to any one of claims 2 to 4, wherein a support base member is attached to the longitudinal movement guide means, and the rotation mechanism is attached to the support base member.   The projection welding apparatus according to any one of claims 3 to 5, wherein an electrode rotation unit is attached to the outer cylinder shaft via the advance / retreat driving means. The projection welding apparatus according to claim 1, wherein the component supply passage is configured by a component supply pipe coaxial with the rotation axis .   The projection welding apparatus according to any one of claims 1 to 7, wherein temporary locking means for temporarily locking the component is disposed between the component supply passage and the holding portion.

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