JP2014097522A - One-sided spot welder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a one-sided spot welder capable of executing excellent spot welding, regardless of a shape of a welding object member.SOLUTION: The one-sided spot welder comprises a control device 50 for controlling an X axis feed mechanism 17, a Y axis feed mechanism 21, a Z axis feed mechanism 25, a θ axis rotary mechanism 34 and an α axis rotary mechanism 35 so that a movable electrode 33 vertically contacts with a welding expected part expected to apply spot welding in a work 2, in which the control device 50 controls respective feed operations of these X axis feed mechanism 17, Y axis feed mechanism 21 and Z axis feed mechanism 25 so that predetermined pressurizing force F vertically acting on the welding expected part from the movable electrode 33, is provided by a synthesis of X axis directional pressurizing force fx by the X axis feed mechanism 17, Y axis directional pressurizing force fy by the Y axis feed mechanism 21 and Z axis directional pressurizing force fz by the Z axis feed mechanism 25.

Description

  The present invention relates to a one-side spot welder that performs spot welding by sandwiching a member to be welded between a fixed electrode and a movable electrode.

  Conventionally, for example, in the production of automobile parts, spot welding is performed by pressing and pressing a welding gun electrode against a member to be welded that is overlapped at least two sheets, and supplying a current to generate resistance heat between the members to be welded. Has been done. The quality of the joint formed by spot welding can be stabilized by appropriately managing the current value, current supply time, applied pressure, and electrode tip state.

As said welding gun, what was proposed by patent document 1, for example is widely used generally.
The welding gun according to this Patent Document 1 includes a pair of gun arms that are opened and closed by a servo motor with a joint member as a fulcrum, and electrodes are attached to the tip portions of these gun arms that face each other. The portion is sandwiched between a pair of electrodes, pressurized, and spot welded.

  By the way, in the type in which the member to be welded is sandwiched by an openable and closable gun arm such as the welding gun according to Patent Document 1, the shape of the member to be welded is limited by the size of the pocket between the pair of gun arms. Depending on the size or the like, the polymerized portion may not be sandwiched between a pair of electrodes.

  Therefore, a single-side spot welder that performs spot welding by supplying a current in a pressurized state by pressing a movable electrode that can be moved freely from the other side while bringing a fixed electrode into contact with one side of the above-described overlapping portion is, for example, Patent Document 2 is proposed.

JP-A-11-291062 Japanese Patent Laying-Open No. 2005-271017

  The one-side spot welder according to Patent Document 2 described above includes an X-axis feed mechanism that linearly moves the movable electrode along the horizontal X axis, and a Y that moves the movable electrode linearly along the horizontal Y axis that is orthogonal to the horizontal X axis. An axial feed mechanism and a Z-axis feed mechanism that linearly moves the movable electrode along a vertical Z-axis perpendicular to the horizontal X-axis and the horizontal Y-axis are configured.

  By the way, in this one-side spot welding machine, the coordinate position corresponding to the position of the welding target portion of the welded member on the orthogonal coordinates of the X axis and the Y axis by the cooperation of the X axis feed mechanism and the Y axis feed mechanism. Then, the movable electrode is positioned, and spot welding is performed by pressing the movable electrode against the planned welding portion by a Z-axis feed mechanism.

For this reason, when there is a planned welding portion on the horizontal plane portion of the member to be welded, it is possible to perform spot welding satisfactorily by applying a predetermined pressing force perpendicularly from the movable electrode to the planned welding portion.
However, for example, when there is a portion to be welded on the inclined surface portion or the vertical surface portion in the member to be welded, the movable electrode is positioned so as to be in contact with the portion to be welded in a vertical direction by using the X, Y, and Z axes. The three-axis control is impossible due to the structure, and it is impossible to apply a predetermined pressurizing force perpendicularly from the movable electrode to the planned welding site, so that the spot welding cannot be satisfactorily performed on the planned welding site. There is a problem that the shape of a member to be welded that can be spot welded is limited.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a one-side spot welder capable of performing good spot welding regardless of the shape of a member to be welded. is there.

In order to achieve the above object, a one-side spot welder according to the present invention comprises:
A one-side spot welder that performs spot welding by sandwiching at least two or more members to be welded between a fixed electrode fixed at a predetermined position and a movable electrode movable relative to the fixed electrode,
An X-axis feed mechanism that linearly moves the movable electrode along a horizontal X-axis;
A Y-axis feed mechanism for linearly moving the movable electrode along a horizontal Y-axis orthogonal to the horizontal X-axis;
A Z-axis feed mechanism for linearly moving the movable electrode along a vertical Z-axis perpendicular to the horizontal X-axis and horizontal Y-axis;
A θ-axis rotation mechanism that rotates the movable electrode around a vertical θ-axis;
An α-axis rotation mechanism that rotates the movable electrode around a horizontal α-axis;
The X-axis feed mechanism, the Y-axis feed mechanism, and the Z-axis feed mechanism so that the movable electrode comes into contact with the welded portion of the welded member that is scheduled to be spot welded in a vertical direction. And a control device for controlling the θ-axis rotation mechanism and the α-axis rotation mechanism,
In the control device, a predetermined pressurizing force that is applied perpendicularly from the movable electrode to the planned welding site includes an X-axis direction pressurizing force by the X-axis feed mechanism and a Y-axis direction pressurizing force by the Y-axis feed mechanism. The feed operation of each of the X-axis feed mechanism, the Y-axis feed mechanism, and the Z-axis feed mechanism is controlled so as to be obtained by combining with the Z-axis direction pressurizing force by the Z-axis feed mechanism. Yes (first invention).

  In the present invention, a bed comprising a welding gun in which the movable electrode, the θ-axis rotating mechanism, and the α-axis rotating mechanism are arranged along the vertical Z-axis, and constituting the basis of the machine body portion of the one-side spot welder. An X-axis beam member extending in the horizontal X-axis direction is installed via a column member that is erected at a predetermined interval in the X-axis beam member, and in the horizontal Y-axis direction via the X-axis feed mechanism. It is preferable that an extending Y-axis beam member is assembled, and the welding gun is assembled to the Y-axis beam member via the Y-axis feed mechanism and the Z-axis feed mechanism (second invention).

  In the present invention, the θ-axis rotation mechanism includes a θ-axis rotation bracket that rotates about a vertical θ-axis, and the α-axis rotation mechanism is attached to the θ-axis rotation bracket so as to be rotatable about a horizontal α-axis. It is preferable that an α-axis rotating housing that is rotated around the horizontal α-axis is provided, and a movable electrode support rod that supports the movable electrode is incorporated in the α-axis rotating housing (third invention).

  In the present invention, it is preferable that the movable electrode support rod is pushed and urged toward the distal end side where the movable electrode is mounted by a compression coil spring incorporated between the α-axis rotating housing and the movable electrode support rod (fourth invention). ).

According to the present invention, a total of five axes including a horizontal X axis, a horizontal Y axis, a vertical Z axis, a vertical θ axis, and a horizontal α axis are provided as control axes. The movable electrode can be positioned so that the movable electrode contacts perpendicularly.
Further, the predetermined pressurizing force that is applied perpendicularly from the movable electrode to the site to be welded is the X-axis direction pressurizing force by the X-axis feed mechanism, the Y-axis direction pressurizing force by the Y-axis feed mechanism, and the Z-axis feed mechanism. Since it is obtained by combining with the Z-axis direction pressurizing force, the predetermined pressurizing force can be reliably applied perpendicularly from the movable electrode to the site to be welded.
Therefore, good spot welding can be performed regardless of the shape of the member to be welded.
In addition, since it is not necessary to separately provide an actuator for generating pressure, the welding speed can be increased by reducing the weight of the apparatus, and the apparatus can be simplified.

  By adopting the configuration of the second invention, a high-rigidity support structure is constructed as a support structure that supports the welding gun by the X-axis beam member supported by the column member on the bed and the Y-axis beam member orthogonal thereto. Therefore, the speed of each feed mechanism can be increased, and the combined pressure by each feed mechanism can be increased. Therefore, the welding time can be shortened, and good spot welding is performed even if the member to be welded is relatively thick (for example, plate thickness: 1.2 to 4.5 mm). be able to.

  By adopting the configuration of the third aspect of the invention, the θ-axis rotation mechanism and the α-axis rotation mechanism can be combined in a compact manner, so that the apparatus configuration can be reduced in size.

  By adopting the configuration of the fourth invention, it is possible to buffer the reaction when the movable electrode supported by the movable electrode support rod comes into contact with the member to be welded, and to follow the deformation of the member during welding. However, the predetermined pressing force by the movable electrode can be stably applied.

1 is an overall perspective view of a one-side spot welder according to an embodiment of the present invention. It is a top view of the one side spot welder of this embodiment. (A) is a figure which fractures | ruptures and represents by the A arrow directional view of FIG. 2, (b) is a figure which fracture | ruptures and represents a part by the B arrow directional view of FIG. FIG. 4 is a view broken away and represented by a view in the direction of arrow C in FIG. 3. FIG. 4 is a cross-sectional view of an enlarged part D of FIG. 3. It is a functional block diagram of a control device. It is a figure showing the mode of positioning of the movable electrode with respect to a workpiece | work. It is a figure showing the mode of the action of the pressurization force of the movable electrode with respect to a workpiece | work.

  Next, specific embodiments of the one-side spot welder according to the present invention will be described with reference to the drawings.

<Overview of single-side spot welder>
The one-side spot welding machine 1 shown in FIG. 1 has two welded members 2a and 2b partially overlapped with each other as workpieces 2 to be welded to the spot welded workpiece 2a, Spot welding is performed on a predetermined welding scheduled site to be welded in the overlapped portion 2b, and a bed 3 is provided that forms the basis of the machine body portion of the one-side spot welder 1.

<Description of bed>
The bed 3 has a quadrangular shape in a plan view extending along the horizontal X axis and the horizontal Y axis perpendicular to each other in the horizontal direction, and has a required thickness along the vertical Z axis perpendicular to the X axis and the Y axis. Have.

<Description of index table>
On the bed 3, an index table 5 that can be rotated and indexed in the horizontal direction by an indexing motor 4 is installed.
A workpiece support 6 is installed on the index table 5, and the workpiece 2 is placed on the workpiece support 6.
A required fixed electrode 7 is fixed to the work support 6 so as to come into contact with the work to be welded on the work 2.

<Explanation of fixed electrode electrical wiring>
The fixed electrode 7 is connected to the negative pole of the power supply device (both not shown) through the index table 5, the bed 3 and a required cable by a bus bar (bar-shaped conductor) (not shown) from the work support 6.
In addition, although detailed description by illustration is abbreviate | omitted, in the current path | route from a power supply device to the fixed electrode 7, a current path | route is carried out between two members which move relatively, such as the bed 3 and the index table 5, for example, and other important points. A breaker is provided for mechanically connecting and disconnecting.

<Description of X-axis beam member and X-axis slider>
On one side of the bed 3 in the horizontal Y-axis direction, a pair of support members 8 and 8 are erected and fixed so as to be positioned on both sides of the horizontal X-axis direction so as to straddle the support members 8 and 8. An X-axis beam member 9 extending in the horizontal X-axis direction is fixed to the support members 8 and 8.
On the X-axis beam member 9, a pair of linear guides 10, 10 extending in the horizontal X-axis direction and arranged at a predetermined interval in the horizontal Y-axis direction are provided, and linear motion guides are provided to these linear guides 10, 10. An X-axis slider 11 is attached so as to be movable in the horizontal X-axis direction.

<Description of Y-axis beam member and Y-axis slider>
A Y-axis beam member 12 extending in the horizontal Y-axis direction is fixed to one end of the X-axis slider 11 in the horizontal X-axis direction.
On the surface of the Y-axis beam member 12 facing the other side in the horizontal X-axis direction, a pair of linear guides 13 and 13 extending in the horizontal Y-axis direction and arranged at a predetermined interval in the vertical Z-axis direction are provided. A Y-axis slider 14 that is linearly guided by these linear guides 13 and 13 is attached to be movable in the Y-axis direction.

<Description of Z-axis beam member and Z-axis slider>
As shown in FIG. 3A and FIG. 4, a Z-axis slider 15 is disposed on the other side of the Y-axis slider 14 in the horizontal X-axis direction, and between these Z-axis slider 15 and the Y-axis slider 14. Are provided with a pair of linear guides 16 and 16 extending in the vertical Z-axis direction and arranged at a predetermined interval in the horizontal Y-axis direction. The linear guides 16 and 16 are linearly guided to the Z-axis slider 15. Is movable in the vertical Z-axis direction with respect to the Y-axis slider 14.

<Description of X-axis feed mechanism>
As shown in FIG. 2, the X-axis feed mechanism 17 that moves the X-axis slider 11 in the horizontal X-axis direction includes a ball screw shaft 18 that extends in the horizontal X-axis direction. The ball screw shaft 18 is attached to the X-axis beam member 9 so as to be rotatable about its axis.
A ball nut 19 fixed to the X-axis slider 11 is screwed onto the ball screw shaft 18, and an X-axis feed motor 20 is connected to one end of the ball screw shaft 18 so as to transmit rotational power.
When the ball screw shaft 18 is rotationally driven by the operation of the X-axis feed motor 20, the ball nut 19 is linearly moved in the horizontal X-axis direction, and the X-axis slider 11 is moved to the horizontal X along with the linear movement of the ball nut 19. It is designed to move linearly in the axial direction.

<Description of Y-axis feed mechanism>
The Y-axis feed mechanism 21 that moves the Y-axis slider 14 in the horizontal Y-axis direction includes a ball screw shaft 22 that extends in the horizontal Y-axis direction. The ball screw shaft 22 is attached to the Y-axis beam member 12 so as to be rotatable about its axis.
A ball nut 23 fixed to the Y-axis slider 14 is screwed onto the ball screw shaft 22, and a Y-axis feed motor 24 is connected to one end of the ball screw shaft 22 so as to transmit rotational power.
When the ball screw shaft 22 is rotationally driven by the operation of the Y-axis feed motor 24, the ball nut 23 is linearly moved in the horizontal Y-axis direction, and the Y-axis slider 14 is moved horizontally in accordance with the linear movement of the ball nut 23. It is designed to move linearly in the axial direction.

<Description of Z-axis feed mechanism>
As shown in FIGS. 3A and 3B, the Z-axis feed mechanism 25 that moves the Z-axis slider 15 in the vertical Z-axis direction includes a ball screw shaft 26 that extends in the vertical Z-axis direction. . The ball screw shaft 26 is attached to the Y-axis slider 14 so as to be rotatable about its axis.
A ball nut 27 fixed to the Z-axis slider 15 is screwed onto the ball screw shaft 26, and a driven timing pulley 28 is fixed to one end portion (upper end portion) of the ball screw shaft 26.
The Y-axis slider 14 is provided with a Z-axis feed motor 29 at a predetermined inter-axis distance on one side in the horizontal X-axis direction with respect to the ball screw shaft 26. The drive timing pulley 30 is fixed.

  A timing belt 31 is wound around the drive timing pulley 30 and the driven timing pulley 28, and the rotation power of the Z-axis feed motor 29 is driven by the operation of the Z-axis feed motor 29. When transmitted to the ball screw shaft 26 via the timing belt 31 and the driven timing pulley 28, the ball nut 27 is linearly moved in the vertical Z-axis direction, and the Z-axis slider 15 is vertically moved along with the linear movement of the ball nut 27. It is designed to move linearly in the Z-axis direction.

<Description of welding gun>
A welding gun 32 is attached to the Z-axis slider 15.
The welding gun 32 includes a movable electrode 33, a θ axis rotation mechanism 34, and an α axis rotation mechanism 35.

<Description of movable electrode>
As shown in FIG. 5, the movable electrode 33 includes a shank 33a that constitutes a main body portion of the movable electrode 33, and an electrode tip 33b that is substantially used for spot welding is attached to the tip of the shank 33a. And is attached to the movable electrode attachment 37 via the holder 36.

<Description of the θ-axis rotation mechanism>
The θ-axis rotating mechanism 34 rotates the movable electrode 33 about the vertical θ-axis, and is attached to the distal end portion of the main body portion of the welding gun 32 so as to be rotatable about the vertical θ-axis. A θ-axis rotation bracket 38 is provided for support. Rotational power from a θ-axis rotation motor 39 (see FIG. 3A) built in the main body portion of the welding gun 32 is transmitted to the θ-axis rotation bracket 38. When the θ-axis rotating bracket 38 is rotationally driven by the operation of 39, the movable electrode 33 is rotated around the vertical θ axis.
In the present embodiment, the rotation angle of the θ-axis rotating bracket 38 around the vertical θ axis is limited to a range of 0 ° to 180 °.

<Explanation of α axis rotation mechanism>
The α-axis rotation mechanism 35 rotates the movable electrode 33 around the horizontal α-axis, and includes an α-axis rotation housing 40 that constitutes a main body portion of the movable electrode attachment 37. The α-axis rotating housing 40 is attached to the θ-axis rotating bracket 38 so as to be rotatable around the horizontal α-axis.
Rotational power from the α-axis rotary motor 41 is transmitted to the α-axis rotary housing 40, and the α-axis rotary housing 40 is rotated around the horizontal α-axis by the operation of the α-axis rotary motor 41. Then, the movable electrode 33 is rotated around the horizontal α axis.
In the present embodiment, the rotation angle around the horizontal α-axis of the α-axis rotation housing 40 is limited to a range of 0 ° to 180 °.

<Description of movable electrode fixture>
The movable electrode fixture 37 is configured by incorporating the movable electrode support rod 42 into the α-axis rotating housing 40 described above.
The distal end of the movable electrode support rod 42 is screwed into a female screw provided at the base end portion of the holder 36, and a retaining nut 43 is screwed into the base end portion, so that the spring seat portion at the intermediate portion is engaged. A compression coil spring 44 is fitted on the shaft portion extending from the base end toward the base end.

The movable electrode support rod 42 is fitted into the α-axis rotary housing 40 with the compression coil spring 44 fitted, and the proximal end side of the compression coil spring 44 is pressed by the press plate 46 via the load cell 45.
The base end portion of the movable electrode support rod 42 penetrates the load cell 45 and the presser plate 46 and protrudes from the presser plate 46, and the retaining nut 43 is screwed to the male screw at the base end portion to hold the presser. The movable electrode support rod 42 is prevented from coming out of the α-axis rotation housing 40 by being hooked on the plate 46.

<Description of electric wiring of movable electrode>
The movable electrode 33 passes through the holder 36, the movable electrode attachment 37, the main body portion of the welding gun 32, the Z-axis slider 15, the Y-axis slider 14, the Y-axis beam member 12, the X-axis slider 11, and the X-axis beam member 9. It is connected to a positive pole of a power supply device (not shown) via a bus bar (not shown) and a required cable (not shown).
In addition, although detailed description by illustration is abbreviate | omitted, in the electric current path from a power supply device to the movable electrode 33, it is between two members which move relatively, such as the X-axis beam member 9 and the X-axis slider 11, and other important points, for example. A breaker for mechanically connecting and disconnecting the current path is provided.

  Next, a control device for controlling the one-side spot welder of the present embodiment will be described below using the functional block diagram of FIG.

As shown in FIG. 6, the control device 50 that controls the one-side spot welder 1 includes a main CPU 51 and a servo CPU 52.
The main CPU 51 functions as an overall arithmetic processing unit of the control device 50, while the servo CPU 52 includes the index motor 4, the X-axis feed motor 20, the Y-axis feed motor 24, the Z-axis feed motor 29, It functions as an arithmetic processing unit for each servo motor of the θ-axis rotary motor 39 and the α-axis rotary motor 41.
These CPUs 51 and 52 are mutually connected to a welding current controller 54 including a welding condition calculation unit 55, a storage device 56, and an input device 57 via a system bus 53.

The main CPU 51 gives the servo CPU 52 a position command signal for controlling the position of the movable electrode 33 of the welding gun 32 and a pressure command signal for controlling the pressure.
The servo CPU 52 controls the servo motors 4, 20, 24, 29, 39, 41 via the servo amplifier 58 according to the command signal given from the main CPU 51.
A signal from the encoder 59 corresponding to the rotation amount of the servo motors 4, 20, 24, 29, 39, 41 is input to the servo CPU 52, and the servo motors 4, 20, 24, 29, 39 are input to the servo amplifier 58. , 41 is input with a signal from the current detector 60 corresponding to the current flowing through it.

The welding current controller 54 controls the current supplied from the welding power supply device 61 to the movable electrode 33 of the welding gun 32.
The welding condition calculation unit 55 calculates welding conditions based on the welding data stored in the storage device 56.
The input device 57 is used for inputting various data, switching between a processing mode and a teaching mode, and the like.

<Description of effects>
Spot welding on the workpiece 2 by the one-side spot welder 1 configured as described above is performed as follows.
The main CPU 51 outputs a position command signal to the servo CPU 52 such that the movable electrode 33 comes into contact with the part to be welded perpendicularly. The servo CPU 52 performs position feedback control based on the position command signal from the main CPU 51 and the signal from the encoder 59, and outputs a current command signal (torque command signal) to the servo amplifier 58. The servo amplifier 58 performs feedback control of current based on the current command signal and the signal from the current detector 60, supplies drive current to the servo motors 4, 20, 24, 29, 39, 41, Servo motors 4, 20, 24, 29, 39 and 41 are driven and controlled.
Thus, as shown in FIG. 7, the horizontal plane portion of the workpiece 2 as well as the inclined plane portion and the vertical plane portion are controlled by the five-axis control of the horizontal X axis, the horizontal Y axis, the vertical Z axis, the vertical θ axis, and the horizontal α axis. The movable electrode 33 is also perpendicularly contacted with the planned welding site (where the fixed electrode 7 is disposed), and the movable electrode 33 is perpendicular to the planned welding site regardless of the shape of the workpiece 2 or the like. And can be positioned to contact.

After the above positioning, the main CPU 51 outputs a control switching signal from position control to pressurizing control to the servo CPU 52, and applies a predetermined pressurizing force from the movable electrode 33 to the welding scheduled portion vertically. A command signal is output to the servo CPU 52. The servo CPU 52 outputs a current command signal (torque command signal) to the servo amplifier 58 based on the pressure command signal from the main CPU 51. The servo amplifier 58 performs feedback control of current based on the current command signal and the signal from the current detector 60, supplies drive current to the servo motors 4, 20, 24, 29, 39, 41, Servo motors 4, 20, 24, 29, 39 and 41 are driven and controlled. In addition, when controlling the pressurizing force with higher accuracy, current control is performed on the servo motors 4, 20, 24, 29, 39, and 41 using the load signal from the load cell 45 as a feedback signal.
Thus, as shown in FIG. 8, the X-axis direction pressing force fx by the X-axis feeding mechanism 17, the Y-axis direction pressing force fy by the Y-axis feeding mechanism 21, and the Z-axis direction pressing force fz by the Z-axis feeding mechanism 25. Thus, the predetermined applied force F that is applied perpendicularly to the planned welding site from the movable electrode 33 is obtained, and the predetermined applied force F can be applied to the scheduled welding site perpendicularly from the movable electrode 33.
Therefore, good spot welding can be performed regardless of the shape of the workpiece 2 and the like.

Moreover, according to the one side spot welder 1 of this embodiment, the following effects can be obtained.
(1) Since it is not necessary to separately provide an actuator for generating a pressurizing force, the welding speed can be increased by reducing the weight of the apparatus, and the apparatus can be simplified.
(2) It is possible to construct a high-rigidity support structure for supporting the welding gun 32 by the X-axis beam member 9 supported by the support members 8 and 8 on the bed 3 and the Y-axis beam member 12 orthogonal thereto. Therefore, it is possible to increase the speed of each of the feed mechanisms 17, 21, 25, and to increase the combined pressure F by each of the feed mechanisms 17, 21, 25. Therefore, it is possible to shorten the welding time, and even if the workpiece 2 is relatively thick (generally, a thick thickness requires a large pressing force) (for example, (Thickness: 1.2 to 4.5 mm), and good spot welding can be performed.
(3) Since the α-axis rotating housing 40 is attached to the θ-axis rotating bracket 38 so as to be rotatable around the horizontal α-axis, and the movable electrode support rod 42 is incorporated in the α-axis rotating housing 40, the θ-axis rotating mechanism 34 and the α The shaft rotation mechanism 35 can be gathered in a compact manner, and the welding gun 32 can be downsized.
(4) Since the movable electrode support rod 42 incorporated in the α-axis rotating housing 40 is urged by the compression coil spring 44 so as to be pushed toward the distal end side, the movable electrode support rod 42 is supported by the movable electrode support rod 42. The reaction when the electrode 33 comes into contact with the workpiece 2 can be buffered, and a predetermined pressure can be stably applied by the movable electrode 33 while following some deformation of the member during welding.

  The one-side spot welder of the present invention has been described based on one embodiment. However, the present invention is not limited to the configuration described in the above-described embodiment, and the configuration is appropriately set within the scope not departing from the gist thereof. It can be changed.

  The one-side spot welding machine of the present invention positions the movable electrode so as to make a vertical contact with the planned welding site regardless of the shape of the member to be welded, and the vertical position from the movable electrode to the planned welding site. Since it has a characteristic that a predetermined pressing force can be applied reliably, it can be suitably used for spot welding applications of relatively complex shapes such as automobile parts.

DESCRIPTION OF SYMBOLS 1 One side spot welding machine 2 Workpieces 2a and 2b To-be-welded member 3 Bed 7 Fixed electrode 8 Strut member 9 X-axis beam member 12 Y-axis beam member 17 X-axis feed mechanism 21 Y-axis feed mechanism 25 Z-axis feed mechanism 32 Welding gun 33 Movable electrode 34 θ-axis rotating mechanism 35 α-axis rotating mechanism 38 θ-axis rotating bracket 40 α-axis rotating housing 42 movable electrode support rod 44 compression coil spring 50 control device

Claims (4)

A one-side spot welder that performs spot welding by sandwiching at least two or more members to be welded between a fixed electrode fixed at a predetermined position and a movable electrode movable relative to the fixed electrode,
An X-axis feed mechanism that linearly moves the movable electrode along a horizontal X-axis;
A Y-axis feed mechanism for linearly moving the movable electrode along a horizontal Y-axis orthogonal to the horizontal X-axis;
A Z-axis feed mechanism for linearly moving the movable electrode along a vertical Z-axis perpendicular to the horizontal X-axis and horizontal Y-axis;
A θ-axis rotation mechanism that rotates the movable electrode around a vertical θ-axis;
An α-axis rotation mechanism that rotates the movable electrode around a horizontal α-axis;
The X-axis feed mechanism, the Y-axis feed mechanism, and the Z-axis feed mechanism so that the movable electrode comes into contact with the welded portion of the welded member that is scheduled to be spot welded in a vertical direction. And a control device for controlling the θ-axis rotation mechanism and the α-axis rotation mechanism,
In the control device, a predetermined pressurizing force that is applied perpendicularly from the movable electrode to the planned welding site includes an X-axis direction pressurizing force by the X-axis feed mechanism and a Y-axis direction pressurizing force by the Y-axis feed mechanism. The one-side spot is characterized in that the feed operations of the X-axis feed mechanism, the Y-axis feed mechanism, and the Z-axis feed mechanism are controlled so as to be obtained by combining with the Z-axis direction pressurizing force by the Z-axis feed mechanism. Welding machine. A welding gun comprising the movable electrode, the θ-axis rotation mechanism, and the α-axis rotation mechanism arranged along the vertical Z axis;
An X-axis beam member extending in the horizontal X-axis direction is installed via a column member standing at a predetermined interval on a bed that forms the basis of the machine body portion of the one-side spot welder,
A Y-axis beam member extending in the horizontal Y-axis direction via the X-axis feed mechanism is assembled to the X-axis beam member,
The one-side spot welder according to claim 1, wherein the welding gun is assembled to the Y-axis beam member via the Y-axis feed mechanism and the Z-axis feed mechanism. The θ-axis rotation mechanism includes a θ-axis rotation bracket that is rotated around a vertical θ axis.
The α-axis rotation mechanism includes an α-axis rotation housing that is attached to the θ-axis rotation bracket so as to be rotatable around a horizontal α-axis and is rotated around the horizontal α-axis.
The one-side spot welder according to claim 1 or 2, wherein a movable electrode support rod for supporting the movable electrode is incorporated in the α-axis rotary housing. 4. The one-side spot welder according to claim 3, wherein the movable electrode support rod is pushed and urged toward a distal end side to which the movable electrode is mounted by a compression coil spring incorporated between the α-axis rotating housing and the movable electrode support rod.

Images