JP2000061646A - Portable spot welding gun - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an electrode arm, which is most suitable for a workpiece of different shape, to be exchanged and mounted easily and quickly against a welding gun body. SOLUTION: The retracting clamp 30 of a gun body 16 pulls in a fixing hook 28 formed in electrode arms 14a, 14b, and draws the arms fixedly into the connecting opening of the arm holders 18a, 18b of the gun body 16. A water feeding port on the arm side is formed at the rear end of the electrode arms 14a, 14b, while one on the gun body side is formed on the arm holders 18a, 18b; by connecting both ports, water is provided cooling the electrodes 12a, 12b. The water feeding port on the arm side and that on the gun body side are connected only by the retracting action, supplying also an electric power for welding; therefore, the electrode arm can be exchanged and mounted quickly and easily.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable spot welding gun, and more particularly to an improvement of a portable spot welding gun capable of easily and quickly exchanging and mounting an electrode arm suitable for a work having a different shape on a gun body.

[0002]

2. Description of the Related Art Conventionally, in a vehicle body assembly process of an automobile or the like, a welding process is arranged at various places, and a robot welding device, a manual welding device or the like sequentially welds a predetermined welding place. Spot welding is performed by sandwiching a welding part of a work with a pair of electrodes and applying a predetermined electric power. FIG. 14 shows a schematic configuration diagram of a welding gun 100 for spot welding. In this welding gun 100, a pair of electrode arms 104 each having an electrode 102 at its tip is fixed rotatably around a shaft 106. When welding a work to be welded, the electrodes 102 at the tips of the pair of electrode arms 104 hold the welding part of the work, and in this holding state,
This is performed by supplying a predetermined amount of electric power to the electrode 102. In addition, since the electrode 102 becomes extremely hot during welding, the electrode arm 104 is not attached to the electrode 102.
Electrode cooling water is constantly circulated from the gun body 108 side via the to prevent damage to the electrode 102 and reduction in welding efficiency.

By the way, in a car body assembly process and the like of an automobile, a plurality of welding processes are present, and a welding part of a work is different for each process, and an electrode arm 104 to be used is also required to have a shape suitable for the welding part. In other words, in order to perform stable welding, the electrode arm 10 is different depending on whether the welding site is shallow or deep from the end face of the work.
It is necessary to change the length of 4. Further, in a work having a protrusion or a bent portion in front of the welded portion, an electrode or an electrode arm that can hold the welded portion while avoiding the protrusion or the bent portion is required.

Conventionally, in order to meet the above-mentioned requirements, a plurality of welding apparatuses having a spot welding gun having an electrode and an electrode arm suitable for a welding site have been individually prepared. Further, as shown in FIG. 14, in the structure in which the electrode arm 104 can be replaced by the bolt 110, or in spot welding using a robot, Japanese Patent Application Laid-Open No. 7-30878 can be used.
As shown in Japanese Patent Publication No. 3, the electrode arm was replaced by a cam mechanism as needed.

[0005]

However, there is a problem that it is not preferable to arrange a plurality of welding devices on the line side of the welding process in consideration of the arrangement space and equipment cost. Even in the case where the electrode arm 104 can be replaced as shown in FIG. 14, the replacement work involving the attachment / detachment of bolts takes a very long time. Further, when a cam mechanism or the like is used, the drive mechanism becomes complicated and the weight increases, so that it is difficult to use it by manual welding. Furthermore, as described above, since the electrode cooling water is supplied to the inside of the electrode arm 104, it is necessary to perform the water stop operation of the electrode cooling water when the electrode arm 104 is replaced, and the replacement work becomes more complicated. .

In particular, when the assembly work is performed in a state where various vehicle types are mixed, such as a car body assembly line, or when the vehicle types are frequently changed, that is, the welded portion is changed, the conventional structure is quick. There is a problem that the electrode arm cannot be replaced.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to easily and quickly replace and attach an electrode arm suitable for a work having a different shape to the gun body. It is intended to provide a portable spot welding gun.

[0008]

In order to achieve the above-mentioned object, a first aspect of the present invention is to provide a pair of electrode arms for supporting electrodes at their tips, and at least welding power and electrode cooling water in the electrode arms. And a gun main body that removably supports the electrode arm, and a portable spot welding gun that performs spot welding by sandwiching a work with the electrode, wherein the electrode arm is provided around the electrode. An arm side water supply port that has an operation pin that communicates with a cooling channel that circulates the electrode cooling water and controls the inflow and outflow of the electrode cooling water, and a fixing provided on the outer peripheral surface that fixes the electrode arm to the gun body. And a connection opening capable of being electrically connected to the electrode arm,
A retractable clamp that engages with the fixing hook to retract the electrode arm into the connection opening to at least electrically connect and fix the electrode arm, and a valve that can be connected to the arm side water supply port and is opened and closed by the operation pin. And a main body side water supply port that communicates with a cooling water source.

According to this structure, the electrode arm fixing hook is pulled in or opened by the pull-in clamp of the gun main body, and the electrode arm and the gun main body are electrically contacted and separated and fixed and released easily. In addition, the valve on the main body side water supply port is controlled to open and close by the contact and separation of the arm side water supply port when the electrode arm is retracted and opened, so it is possible to reliably and easily supply and stop the electrode cooling water. It is possible to replace and attach the electrode arm quickly and easily.

In order to achieve the above object, in the second invention, in the first invention, the connection opening has a rectangular shape, and at least one of inner wall surfaces thereof has a tapered tapered surface, The surface facing the tapered surface is connectable to the rear end of the electrode arm having the same shape.

According to this structure, the electrode arm and the gun body can be firmly connected and fixed by the wedge effect of the tapered surface only by the pulling operation of the fixing hook by the pull-in crank bar, and a good electrical connection can be achieved. It can be performed.

Further, in order to achieve the above object, a third invention is the same as the first or second invention, further, the gun body includes a movable electrode which can be brought into contact with and separated from one of the electrode arms. And an electrode driving means for moving the moving electrode and opening / closing the electrode arm by moving the moving electrode.

According to this structure, the electrical connection between the gun body and the electrode arm and the opening / closing operation of the electrode arm can be easily and quickly performed only by connecting the electrode arm and the movable electrode.

In order to achieve the above object, in a fourth aspect based on the third aspect, the movable electrode has a substantially U-shaped cross section, and the opening and closing operation of the electrode arm is performed on two opposing surfaces. And the welding power circuit is closed when the electrode arm is closed.

According to this structure, the electric connection between the two and the opening / closing operation of the electrode arm can be performed only by inserting the electrode arm from the open end of the moving electrode having a substantially U-shaped cross section. Replacement mounting can be performed quickly and easily.

Further, in order to achieve the above object, in the fifth invention, in the third invention, the electrode arm oscillates around an advancing / retreating electrode arm or a fulcrum having a bent portion at a rear end and capable of advancing / retreating. The movable electrode is a movable oscillating electrode arm, and the movable electrode has a main body having a substantially U-shaped cross section and an openable / closable lid for sealing the open end of the main body. Is movably housed in an internal space of a moving electrode formed by the lid portion and the main body portion, and the moving electrode performs the opening / closing operation of the electrode arm with the lid portion and the main body portion facing the lid electrode. The welding power circuit is closed when the electrode arm is closed.

According to this structure, since the bent portion of the electrode arm is movably housed in the internal space of the moving electrode which is composed of the main body portion having a substantially U-shaped cross section and the lid portion, Since the advancing / retreating electrode arm or the oscillating electrode arm can be operated even by a single reciprocating operation, it is possible to perform the electrical connection with the gun body and the opening / closing operation of the electrode arm simply by inserting the bent portion of the electrode arm, Replacement and mounting can be performed quickly and easily even with electrode arms having different operating modes.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention (hereinafter referred to as an embodiment) will be described below with reference to the drawings.

Embodiment 1. FIG. 1 shows a schematic configuration diagram of a portable spot welding gun 10 according to the first embodiment. Portable spot welding gun 10 of the first embodiment
Is an electrode 1 for sandwiching a work piece (not shown) to be welded.
Electrode arms 14a and 14b having 2a and 12b, and a gun body 16 to which the electrode arms 14a and 14b can be connected
It consists of and. The electrode arms 14a and 14b
Is formed of a rod-shaped member having a rectangular cross section, and internally has a cooling flow path for guiding electrode cooling water described later to the vicinity of the electrodes 12a and 12b. Also, the gun body 16 connects and houses the electrodes 12a and 12b, and is capable of swinging about a shaft 10a, and arm holders 18a and 18b, and the electrode arm 1.
4a, 14b, a transformer 20 for supplying electric power via a cable 20a, an electrode driving means for opening and closing an arm holder 18a to which the electrode arm 14a is connected, and an electrode driving means for welding the electrode arms 14a, 14b. A cooling water pipe (tube) (not shown) for supplying electrode cooling water for cooling is included. The electrode driving means includes, for example, a ball screw 22 for driving the arm holder 18a to open and close, a motor 24 for driving the ball screw 22 to rotate, and a reduction gearbox for decelerating the rotation of the motor 24 and transmitting the rotation to the ball screw 22. 26 etc. A welding gun of a type in which the electrode arms 14a and 14b swing around a shaft 10a as shown in FIG. 1 to hold a welding portion of a work is hereinafter referred to as "X gun".

The characteristic feature of the first embodiment is that the connection and fixing of the electrode arms 14a and 14b and the gun body 16 and the electrical connection and the connection of the electrode cooling water supply line are performed only by the retracting operation of the clamp. .

As shown in FIGS. 1 and 2A to 2C,
Projecting fixing hooks 28 are formed on both side surfaces of the electrode arm 14a. The arm holder 18a of the gun body 16 has a retracting clamp 30 that engages with the fixing hook 28 and retracts the electrode arm 14a toward the arm holder 18a. The retractable clamp 30
Is composed of a clamp arm 30a that actually engages with the fixing hook 28, and a clamp lever 30b that can fall down so as to pull the clamp arm 30a rightward in the drawing.

As shown in FIG. 3A, the arm holder 18a of the gun body 16 is formed with a connection opening 32 for receiving the rear end of the electrode arm 14a. The internal cross section of this connection opening 32 is for receiving the electrode arm 14
It has a rectangular shape similar to that of a, and one surface of the inner wall surface has a tapered taper surface 32a, and an electrode connected to the transformer 20 is arranged on the taper surface 32a and the facing surface 32b. Further, the rear end portion 34 of the electrode arm 14a has a taper 34a having the same inclination as the taper surface 32a. In addition, as shown in FIG. 3C (A-A cross section of FIG. 3B), an insulator 36 is arranged on two surfaces adjacent to the tapered surface 32 a of the connection opening 32, and two sheets are provided. The arrangement interval a of the insulator 36 is formed wider than the width of the electrode arm 14a. Therefore, the electrode arm 14a is connected to the connection opening 3
2 and the tapered surface 32
Since only two surfaces facing a are in contact with the electrode arm 14a, the electrode arm 14a is pulled into the connection opening 32 by the pull-in clamp 30 shown in FIG. 2 regardless of the inserted state of the electrode arm 14a. The rear end portion 34 and the electrode in the connection opening 32 can ensure a reliable contact and a good contact pressure by the wedge effect of the tapered surface 32a, and the electrode arm 14a from the gun body 16 side can be secured. A stable power supply can be performed. Since the electrode arm 14a is inserted along the tapered surface 32a, it is not necessary to perform accurate positioning at the time of insertion, and the insertion operation can be easily performed.

Further, inside the electrode arm 14a,
As shown in FIGS. 4A and 4B, the electrode cooling water for cooling the electrode 12a heated during welding is supplied to the electrode 12a.
A cooling flow path 38 that leads to the vicinity is formed. In this cooling flow path 38, an in-side flow path for flowing the electrode cooling water into the electrode 12a and an out-side flow path for discharging the electrode cooling water used for cooling and having a high temperature are connected in the vicinity of the electrode 12a. It has a substantially U-shaped shape (FIG. 4A shows only the in-side channel). The cooling water flow path 38 is formed at the rear end of the electrode arm 14a, and the arm side water supply port 4 is formed.
It is connected to 0. In this arm side water supply port 40, as shown in FIG. 4 (c) (BB cross section of FIG. 4 (b)), operation pins supported by three-pronged stays 42a (in side), 42b (out side). 44a (in side), 44b
(Out side) is arranged.

On the other hand, inside the connection opening 32 of the arm holder 18a, as shown in FIGS. 4 (a) and 4 (b), valves 46 (in side and out side) corresponding to the operation pins 44a and 44b are provided. A main body side water supply port 48 having is provided. The valve 46 is always opened by an urging means such as a spring 50 and the opening end 48a of the main body side water supply port 48 is opened.
Is urged by. Then, as shown in FIG.
Only when the electrode arm 14a is inserted to a predetermined position of the connection opening 32 of the arm holder 18a, the operation pin 4 is inserted.
4a pushes down the valve 46 against the biasing force to open it.

Accordingly, the in-side valve 46 allows the inflow of the electrode cooling water to the electrode 12a side when the electrode arm 14a is completely inserted into the arm holder 18a, and the out-side valve 46 allows the electrode cooling water to flow into the electrode 12a. The outflow (discharge) of the electrode cooling water used for cooling is permitted, and the inflow / outflow control of the electrode cooling water is performed. A packing such as an O-ring 52 is arranged at the tip of the arm side water supply port 40, and the O-ring 5 is inserted before the operation pin 44a pushes the valve 46.
2 contacts the outer wall of the main body side water supply port 48. As a result, it is possible to prevent water leakage when connecting the electrode arm 14a and the arm holder 18a.

As described above, the fixing hook 28 formed on the electrode arm 14a is attached to the arm holder 18 of the gun body 16.
By pulling into the connection opening 32 of a by the pull-in clamp 30, fixing of the electrode arm 14a to the gun body 16, electrical connection, and inflow / outflow control of electrode cooling water can be performed at the same time. Further, by opening the retracting clamp 30, it is possible to smoothly open the electrode arm 14a, cut off the electrical connection, and stop the electrode cooling water. Further, in the above description, an example in which the electrode arm 14a is connected to the arm holder 18a has been described, but the electrode arm 14b also has a similar structure to be attached / fixed / opened to / from the arm holder 18b, electrically connected / interrupted, and cooled. Water can be supplied and water can be stopped in the same manner.

When operating the portable spot welding gun 10 as described above, first, the desired electrode arm 14a,
14b is attached and fixed to the arm holders 18a and 18b of the gun body 16 by the retracting clamp 30. In the case of FIG. 1, the arm holder 18a to which the electrode arm 14a is fixed
Ball screw 2 through the free joint 54 at the rear end
2, the arm holder 18b to which the electrode arm 14b is fixed is fixed to the gun body 16. That is, the arm holder 18a side constitutes a movable side arm, and the arm holder 18b side constitutes a fixed side arm. When welding is performed, the motor 24 is rotated in a predetermined direction by a predetermined amount and the ball screw 22 is pulled down.
a rotates clockwise about the axis 10a, and the electrodes 12a,
The space between 12b opens. The welding portion of the work is positioned between the opened electrodes 12a and 12b, the motor 24 is rotated in the reverse direction, and the ball screw 22 is pulled up, whereby the arm holder 18
a rotates counterclockwise, and the electrodes 12a and 12b hold the welded part of the work at a predetermined pressure. In this state, the electrode 1
By supplying a predetermined electric power to the electrodes 12a and 12b while supplying the electrode cooling water around the electrodes 2a and 12b, it is possible to weld the welding portion of the work. After welding,
The motor 24 is driven to rotate the arm holder 18a clockwise to open the work. Then, if necessary,
Opening and closing the retractable clamp 30 allows the desired electrode arm 1
The attachment / detachment of 4a and 14b is performed. In this way, the electrode arms 14a and 14b can be replaced quickly and easily by opening and closing the retracting clamp 30.

FIGS. 5A to 5D show an electrode arm 1 suitable for works having different shapes and works having different welding sites.
Shape examples of 4a and 14b are shown. Figure 5 (a) shows
The short electrode arms 14a and 14b that are optimal when the welding site is shallow from the work end face are shown. FIG. 5B shows the long electrode arm 14 that is optimal when the welding site is deep from the work end face.
a and 14b are shown. Further, FIG. 5 (c) shows electrode arms 14a and 14b which are optimal for welding a work having a short flange in front of the welding site, and FIG. 5 (d) shows a work having a long flange in front of the welding site. The electrode arms 14a and 14b most suitable for welding are shown. As described above, according to the first embodiment, with respect to the single gun body 16, the electrode arm 1 having a shape corresponding to the work shape or the welding site is formed.
Since the replacement mounting of 4a and 14b can be easily performed, the facility cost and the space on the welding line side can be easily reduced, and the usability of the portable spot welding gun can be improved.

Embodiment 2. FIG. 6 shows a schematic configuration diagram of the portable spot welding gun 56 of the second embodiment. In the second embodiment, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the case of the portable spot welding gun 56 according to the second embodiment shown in FIG. 6, a pair of electrode arms 58a, 58 is provided.
b forms an electrode arm unit 60 unitized by the holder 58, and the electrode arm unit 60 can be exchangeably attached to the gun body 62. The portable spot welding gun 56 is also an X gun that rotates about the shaft 58c as in the first embodiment. On the gun body 62 side, as in the first embodiment, a transformer 20, a ball screw 22, a motor 24, a reduction gear box 26, a cooling water pipe (tube) (not shown) for supplying electrode cooling water, and the like are provided. ing.

The characteristic feature of the second embodiment is that the electrode arm unit 60 in which the electrode arms 58a and 58b are unitized and the gun body 62 are fixed, electrically connected, and the electrode cooling water supply line is connected and clamped. It is a place where it is performed only by the pull-in operation.

As shown in FIG. 6, the electrode arm unit 6
On the side surface of 0, fixing hooks 64 as shown in FIGS. 7A to 7C are arranged at, for example, two places. In addition, the gun body 62 is provided with a retracting clamp 66 that engages with the fixing hook 64 and retracts the electrode arm unit 60 into the gun body 62 as in the first embodiment.
A connection opening 62a for receiving the rear end portion 60a of the electrode arm unit 60 is formed. The shape of the rear end portion 60a of the electrode arm unit 60 and the shape of the connection opening 62a are the same as those in FIGS. 3A to 3C, and since they have the same functions, description thereof will be omitted. Further, the inside of the rear end portion 60a of the electrode arm unit 60 and the connection opening 62a is shown in FIG.
The arm-side supply port and the body-side supply port shown in (c) are formed, and the electrodes 12a and 12b are controlled by the inflow / outflow control.
The electrode cooling water is circulated in the vicinity of, and the water stop function at the time of connecting the electrode arm unit 60 and the gun body 62 also functions similarly to the first embodiment. In the case of the second embodiment,
In FIGS. 6 and 7C, only the connecting portion between the rear end of the upper electrode arm unit 60 and the gun body 62 is provided with the arm side supply port and the body side of FIGS. 4A to 4C described above. A supply port is formed, and the cooling flow path branches inside the electrode arm unit 60 for the electrode arm 58a and the electrode arm 58b. 6 and 7C, the lower end of the electrode arm unit 60 and the gun body 62 are
The electrical connection structure of FIGS. 3A to 3C is formed only in the connection portion of FIG. In the second embodiment, this electrical connection structure is grounded. The retractable clamp 66 has the same configuration as that of the first embodiment except that the tip of the clamp arm 30a is ring-shaped, and the operating method thereof is also the same as that of the first embodiment.

Therefore, by pulling the rear end portion 60a of the electrode arm unit 60 into the connection opening 62a of the gun body 62 by the pull-in clamp 66, the electrode arm unit 60 and the gun body 62 can be fixed, electrically connected, and supplied with water. It can be done easily and quickly.

As described above, in the second embodiment, only the connection portion between the rear end portion 70 of the lower electrode arm unit 60 and the gun body 62 is electrically connected as shown in FIGS. The structure is formed. That is, only the electrode arm 58b side is fixed to the gun body 62,
As shown in FIG. 8, the 8a side engages with the electrode driving means including the ball screw 22, the motor 24, the reduction gear box 26, and the moving electrode 68 connected through the free joint 54. This moving electrode 68 is shown in FIG.
As shown in (a) and (b), the electrode has a substantially U-shaped cross section, the rear end portion 70 of the electrode arm unit 60 is sandwiched between the facing surfaces 68a and 68b, and the movable electrode 68 is moved to move the electrode. The opening / closing operation on the arm 58a side is performed. The facing surface 68b is connected to the transformer 20 (see FIG. 6) by a cable 72, and supplies electric power required for welding only when the facing surface 68b and the rear end portion 70 contact each other.

That is, as shown in FIG. 9A, by rotating the motor 24 and pushing up the ball screw 22, the moving electrode 58 connected through the free joint 54 moves upward, and the facing surfaces 68a, 68b. The rear end 70 housed in between is pressed against the facing surface 68b, and the facing surface 68b pushes the rear end 70 upward. By pushing the rear end portion 70 upward, the electrode arm 58a side rotates counterclockwise around the shaft 58c,
While performing the closing operation, the electrode 12a is pressed against the electrode 12b (see FIG. 6). As described above, since the facing surface 68b is connected to the transformer 20, the welding power circuit is closed between the electrode arm 58a and the grounded electrode arm 58b when the electrode arm 58a is closed, so that the electric power required for welding is supplied. It is supplied between the electrode 12a and the electrode 12b, and welding is performed on the welding portion of the work held between the electrode 12a and the electrode 12b at a predetermined pressure.

After the welding is completed, as shown in FIG.
By rotating the motor 24 in the reverse direction to pull down the ball screw 22 and the moving electrode 68, the facing surface 6
8a contacts the rear end portion 70. As a result, the contact between the rear end portion 70 and the facing surface 68b is opened, the welding power circuit is opened, and the electrode arm 58a side is rotated in the clockwise direction about the shaft 58c to perform the opening operation of the welded workpiece. Open. An insulating material 74 is inserted between the moving electrode 68 and the free joint 54 to be insulated from the ball screw 22 side.

In this way, by pulling the fixing hook 64 formed on the electrode arm unit 60 with the pull-in clamp 66, the electrode arm unit 60 including the electrode arms 58a and 58b is pulled into the connection opening 62a of the gun body 62. Thereby, fixing of the electrode arm unit 60 to the gun body 62, electrical connection, and inflow / outflow control of the electrode cooling water can be simultaneously performed. Further, by opening the retracting clamp 66, it is possible to smoothly open the electrode arm unit 60, cut off the electrical connection, and stop the electrode cooling water. In the case of the second embodiment, since the electrode arms 58a and 58b can be replaced as a unit, the electrode arm unit 60 can be quickly replaced by a single replacement mounting operation.
Since the movable electrode 68 has a substantially U-shaped cross section with a large opening, the electrode arm unit 60 is provided.
The rear end portion 70 can be inserted easily and quickly without the need for alignment.

Therefore, according to the second embodiment, the electrode arm unit 60 having the electrode arms 58a and 58b having the shape corresponding to the work shape and the welding portion can be easily replaced and attached to the single gun body. be able to. as a result,
The usability of the portable spot welding gun 56 can be improved while easily reducing the equipment cost and the space on the welding line side. In the second embodiment, an example in which the fixing hook 64 and the retractable clamp 66 are arranged on one surface side of the portable spot welding gun 56 (in this case, the other surface side is formed with a stay or the like and is fixed by pressing). Although shown, one may be arranged on each side, or two or more may be arranged.

Embodiment 3. 10 (a) and 10 (b),
The schematic block diagram of the portable spot welding gun 76 of Embodiment 3 is shown. The portable spot welding gun 76 according to the third embodiment has the same X as that of the first and second embodiments.
A structure in which multiple types of electrode arms with different operation modes, such as a gun and an advancing / retreating electrode arm (hereinafter referred to as "C gun") that moves forward / backward to hold a welded part of a workpiece, can be exchanged Has become. Since the basic configuration of the third embodiment is similar to the configuration of the above-described second embodiment, the same components as those of the second embodiment are designated by the same reference numerals and the description thereof will be omitted.

10 (a) and 10 (b), the gun body 78 is supplied with the transformer 20, the ball screw 22, the motor 24, the reduction gear box 26, and the electrode cooling water, as in the other embodiments. A cooling water pipe (tube) (not shown) and the like are provided. Further, for example, two retractable clamps 66 are arranged on the side surface of the gun body 78, and engage with fixing hooks 64 formed on the side surfaces of electrode arm units 80a, 80b, which will be described later, and the electrode arm units 80a, 80b. Is retracted and fixed inside the gun body 78.

The electrode arm unit 80a is shown in FIG.
As shown in (a), the electrode arms 58a and 58b are unitized by a holder 82, and the electrode arm 58a is provided with a shaft 82a.
Rotate about to open and close the electrodes 12a, 12b X
Make up the cancer. On the other hand, the electrode arm unit 8
0b is the electrode arm 84 as shown in FIG.
The a and 84b are unitized by the holder 86, and the electrode arm 84a moves back and forth with respect to the holder 86 in the left-right direction to form a C gun for opening and closing the electrodes 12a and 12b. In the electrode arm units 80a and 80b, the second embodiment
Similarly to the above, a tapered rear end portion as shown in FIGS. 3A to 3C is formed, and a connection opening is also formed on the gun body 78 side. Further, the electrode arm units 80a and 80b and the gun body 78 are provided with the arm side supply port and the body side supply port as shown in FIGS. 4A to 4C, as in the second embodiment. . Therefore, the electric connection and the water supply connection between the electrode arm unit 80a or 80b and the gun body 78 can be easily and quickly performed by the retraction operation by the retraction clamp 66.

In the third embodiment, the electrode arm unit 80a and the electrode arm unit 80 having different operation modes are used.
In order to connect b to a single gun body 78 and make it operable, as shown in FIGS. 11 (a) and 11 (b), the movable-side rear end portion 88 has a ball screw 22 (see FIGS. See b))
It is bent approximately 90 ° with respect to the pulling direction. Further, the movable electrode 90 that can be moved back and forth by the ball screw 22 via the free joint 54 is shown in FIG.
As shown in (b), the transformer 2 is connected by the cable 92.
It is connected to 0. The movable electrode 90 to which the free joint 54 and the cable 92 are connected is shown in FIG.
As shown in (c) to FIG.
0a and an openable / closable lid portion 90b attached to the electrode body 90a to form an internal space 90c capable of accommodating the rear end portion 88. A hook 90d is formed on the lid portion 90b and can be locked when closed by a clamp 90e attached to the electrode body 90a. Therefore, FIGS. 12 (b), (c) and FIG.
As shown in (a) and (b), when the lid 90b is released,
Electrode arm unit 80a or electrode arm unit 8
The rear end portion 0b of 0b can be inserted into the internal space 90c, and the rear end portion 88 can be held inside the internal space 90c when the lid portion 90b is closed.

As described above, since the moving electrode 90 is connected to the ball screw 22 via the free joint 54, as shown in FIG.
2 (b) (not shown in FIG. 2))
When 0 is pushed to the left in the figure, the lid portion 9 of the moving electrode 90 is
0b, the power supply body 94 connected to the transformer 20 formed on the opposite surface is pressed against the rear end portion 88 of the electrode arm unit 80a (80b), and further, the electrode arm unit 8
Press 0a (80b) to the left in the figure. At this time, the electrode arm unit 80a rotates counterclockwise around the shaft 82a, so that the electrode arms 58a and 58b are closed to hold the welded portion of the work and to feed the power supply 9
The welding power circuit of the transformer 20 is closed by the contact between the No. 4 and the rear end portion 88, and the required electric power is supplied from the transformer 20 according to the energization command from the welding control unit to perform welding.

On the other hand, as shown in FIG. 12C, when the moving electrode 90 is pulled rightward in the figure by the reverse driving of the ball screw 22, the connection between the rear end portion 88 and the power feeding member 94 is opened, The welding power circuit opens. Further, when the moving electrode 90 is pulled rightward in the figure, the rear end portion 88 contacts the lid 90b, and the electrode arm unit 80a (80b) is pulled rightward in the figure. At this time, the electrode arm unit 80a is
Since it rotates clockwise about the shaft 82a, the electrode arms 58a and 58b are opened to open the work.
Similarly, also in the case of the electrode arm unit 80b, the electrode arm 84a is moved to the position shown in FIG.
It moves in the left and right direction of (b) to hold and open the welding portion of the work and to open and close the welding power circuit. The rear end portion 88 of the electrode arm unit 80a has a shaft 82a.
A circular motion is performed around the
c is formed to be much larger than the rear end portion 88, and "play" caused by the moving electrode 90 being connected to the ball screw 22 by the free joint 54 causes the rear end portion 88 to be shaken in the circumferential direction. Since it absorbs, the electrode arm unit 80a operates smoothly. Further, even when the rear end portion 88 is housed in the moving electrode 90 by the play, it is possible to perform the work easily and quickly without requiring accurate positioning.

In this way, the fixing hook 64 formed on the electrode arm unit 80a or the electrode arm unit 80b is drawn into the connection opening of the gun body 78 and the clamp 66 is drawn.
By fixing the arm units 80a and 80b having different electrode shapes including the electrode arms 58a and 58b and the electrode arms 84a and 84b to the gun body 78 by
Electrical connection and electrode cooling water supply can be performed simultaneously. Further, by opening the retracting clamp 66, it is possible to smoothly open the electrode arm units 80a and 80b, cut off the electrical connection, and stop the electrode cooling water.
In the case of the third embodiment, the electrode arm unit having the electrode arms of different operation modes can be replaced, so that various weldings can be sequentially and quickly performed without increasing the equipment cost.

The structure of each member in each of the above-described embodiments is an example, and if the electrode arm side can be fixed, electrically connected, and supplied with electrode cooling water by retracting the electrode arm side into the gun main body with the clamp, the present embodiment will be described. The same effect as the form can be obtained.

[0047]

As described above, according to the present invention, it is possible to easily and quickly replace and attach the optimum electrode arm to the work of different shapes on the gun body, so that various welding operations can be performed at the equipment cost and the arrangement space. Can be done without an increase in

[Brief description of drawings]

FIG. 1 is a structural conceptual diagram of a portable spot welding gun according to a first embodiment of the present invention.

FIG. 2 is an explanatory view illustrating the operation of the retractable clamp of the portable spot welding gun according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram illustrating electrical connection between an electrode arm and an arm holder of the portable spot welding gun according to the first embodiment of the present invention.

FIG. 4 is an explanatory diagram illustrating a connection between the arm of the electrode arm of the portable spot welding gun according to the first embodiment of the present invention and the air supply port and the main body side supply port on the arm holder side.

FIG. 5 is an explanatory diagram illustrating a form of an electrode arm suitable for a work having a different shape and a welded portion.

FIG. 6 is a structural conceptual diagram of a portable spot welding gun according to a second embodiment of the present invention.

FIG. 7 is an explanatory diagram illustrating an operation of the retractable clamp of the portable spot welding gun according to the second embodiment of the present invention.

FIG. 8 is an explanatory diagram illustrating an operating structure of an electrode arm unit of the portable spot welding gun according to the second embodiment of the present invention.

FIG. 9 is an explanatory diagram illustrating an operation of the electrode arm unit of the portable spot welding gun according to the second embodiment of the present invention.

FIG. 10 is a structural conceptual diagram of a portable spot welding gun according to a third embodiment of the present invention.

FIG. 11 is an explanatory diagram illustrating a structure of an electrode arm unit of the portable spot welding gun according to the third embodiment of the present invention.

FIG. 12 is an explanatory diagram illustrating the structure and operation of the electrode arm unit and the moving electrode of the portable spot welding gun according to the third embodiment of the present invention.

FIG. 13 is an explanatory diagram illustrating a connection structure between an electrode arm unit and a moving electrode of the portable spot welding gun according to the second embodiment of the present invention.

FIG. 14 is an explanatory diagram illustrating a configuration of a conventional portable spot welding gun.

[Explanation of symbols]

10 Portable spot welding gun, 10a axis, 12
a, 12b electrodes, 14a, 14b electrode arms, 16
Gun body, 18a, 18b arm holder, 20 transformer, 22 ball screw, 24 motor, 26 reduction gear box, 28 fixing hook, 30 retractable clamp, 54 free joint.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Joji Ikushima             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. (72) Inventor Miki Suzuki             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. F-term (reference) 4E065 BA06 BB06

Claims (5)

[Claims] 1. A pair of electrode arms that support electrodes at their tips, and a gun body that supplies at least welding power and electrode cooling water to the electrode arms and detachably supports the electrode arms, A portable spot welding gun for holding a work by an electrode to perform spot welding, wherein the electrode arm communicates with a cooling channel for circulating electrode cooling water around the electrode to control inflow / outflow of electrode cooling water. An arm side water supply port having an operation pin for performing, and a fixing hook provided on an outer peripheral surface for fixing the electrode arm to the gun body, the gun body is electrically connected to the electrode arm. A possible connection opening and a retractable clamp that engages with the fixing hook to retract the electrode arm into the connection opening for at least electrical connection and fixation of the electrode arm. , Portable spot welding gun, characterized in that it comprises a body-side water supply port communicating with the cooling water source having a valve to open and close by possible the operation pin connected to the arm-side water supply port. 2. The welding gun according to claim 1, wherein the connection opening has a rectangular shape, and at least one surface of an inner wall surface of the connection opening has a tapered tapered surface, and a surface facing the tapered surface has the same shape. A portable spot welding gun characterized by being connectable to the rear end of the electrode arm. 3. The welding gun according to claim 1, wherein the gun body further comprises a movable electrode that can be brought into contact with and separated from one of the electrode arms, the movable electrode, and the movable electrode. A portable spot welding gun, comprising: electrode driving means for opening and closing the electrode arm by moving the electrode. 4. The welding gun according to claim 3, wherein the moving electrode has a substantially U-shaped cross section, and the opening and closing operation of the electrode arm is performed on two opposite surfaces, and at the time of closing operation of the electrode arm. Spot welding gun characterized by closing the power circuit for welding. 5. The welding gun according to claim 3, wherein the electrode arm is an advancing / retreating electrode arm having a bent portion at a rear end and capable of advancing / retreating operation, or a swinging electrode arm swingable about a fulcrum, The movable electrode has a main body having a substantially U-shaped cross section, and an openable / closable lid that seals the open end of the main body, and the bent portion is formed by the lid and the main body. The movable electrode is loosely accommodated in the internal space of the movable electrode, and the movable electrode opens and closes the electrode arm with the lid and the main body portion facing the movable electrode. Portable spot welding gun characterized by being closed.