JPH034443Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a capacitor discharge type stud welding gun.

[Prior art] Capacitor discharge type stud welding performs welding by flowing discharge energy from a capacitor charged to a preset level between a stud attached to a welding gun and the base material to be welded. The stud, or welding gun, is positioned relative to the base metal, and the gun trigger is pulled to instantly weld the stud.The welding gun used can be made of mild steel, stainless steel, brass, copper, etc. The contact method is suitable for welding studs made of aluminum, and the gap method is suitable for welding aluminum studs and small-diameter studs, and each type is used in various ways. Contact type welding guns perform welding by discharging the stud while it is in pressure contact with the base metal to generate an arc.On the other hand, with the gap type welding gun, the stud is separated from the base material by a predetermined distance and the stud is discharged in this state. This is a method in which the stud is inserted into the surface of the base material and welding is performed at the same time as an arc is generated.

In this way, capacitor discharge type stud welding
It is widely used in various industrial fields because of its simplicity and ability to weld thin plate-like base materials easily, reliably, and neatly. Also, from the perspective of improving the efficiency of welding work, promoting full automation and labor saving in so-called stationary automatic welding equipment, which has automated welding due to the recent development of industrial robots, and from the perspective of worker safety, etc. Instead of the so-called manual method in which studs are attached by hand to the stud welding gun, studs can be attached automatically from the tip of the welding gun, that is, the tip of the collet, or from the side of the welding gun, that is, the rear end of the collet. Increasingly, devices are being used that automatically attach devices one after another.

Incidentally, in so-called stationary automatic welding equipment in which a welding gun is attached to an operating arm, an automatic supply attachment mechanism in which a stud is attached from the tip of the welding gun is widely used, but in hand-held welding guns, this method is not possible. If an automatic feeding and mounting mechanism is applied, the structure of the gun itself becomes complicated and bulky, and the gun becomes difficult to operate, so a system in which a stud is mounted from the side of the gun is generally used more advantageously. A conventional example of a stud welding gun equipped with an automatic supply and mounting device for mounting studs from the side of the gun is the one described in Japanese Patent Publication No. 10228/1983. In the welding gun disclosed in this patent publication, a chamber is provided in the gun body that communicates with the rear end of the collet attached to the tip of the gun, and a stud is supplied from this chamber to the rear end of the collet. The stud is configured to be pushed toward the tip of the collet by a ram (push rod) provided coaxially with the collet in the gun body portion of the gun, and to be installed at a predetermined installation position.

[Problems to be solved by the invention] This type of automatic stud supply and mounting device has been developed from the viewpoint of improving the efficiency of welding work, promoting full automation in automatic welding equipment, saving labor, and ensuring worker safety. However, when attempting to weld studs made of relatively soft metals such as aluminum or studs with small tips, prior art welding guns such as those described above move the stud from the rear of the collet to a predetermined position at the tip. There is a problem in that when the stud is pushed into position by the ram, the tip at the tip of the stud collides with the receiving surface of the base material, etc., resulting in crushing.
If the tip at the tip of the stud is crushed in this way, even if you pull the trigger of the welding gun during welding, a sufficient arc will not be generated between the stud and the base metal, resulting in failure to weld or a welding defect. ing.

In addition, in the case of aluminum studs, in order to avoid oxidation problems during welding, it is necessary to weld the studs at a certain distance from the base metal rather than in pressure contact with the base metal.

SUMMARY OF THE INVENTION An object of the present invention is to provide a capacitor discharge type stud welding gun that can solve these problems and ensure good welding conditions.

[Means for Solving the Problems] In order to achieve the above object, the capacitor discharge type stud welding gun according to the present invention is supported by a frame so as to be slidable in the axial direction, and has a tip that can be tightened and loosened. A hollow body into which a stud gripping collet is fitted, and a stud supply that is attached to the side of the hollow body and communicates with the center hole to supply the stud to be welded from diagonally backward into the center hole of the hollow body. an adjustable spring member for pressing the hollow body toward its distal end with a predetermined pushing force; a stud extending from the rear into the central hole of the hollow body and loaded into the central hole of the hollow body by the stud feeding device; a piston device that pushes the loaded stud forward and attaches it to the stud gripping collet; and a piston device that forces the piston device rearward when loading the stud, and forces it forward when the loaded stud is attached to the stud gripping collet. and a cylinder device for moving the assembly of the hollow body and the piston device a predetermined distance rearward during the mounting operation of the stud on the gun body.

The frame slidably supporting the hollow body can be configured as a gun housing fixed to the gun handle when the invention is applied to a hand-held welding gun, or can be configured as a gun housing fixed to the gun grip when the invention is applied to a hand-held welding gun, or can be used for a stationary self-operating stud welding gun. When applied to a gun of an apparatus, it can be attached to a gun mounting member of an automatically operated stud welding apparatus.

[Function] In the capacitor discharge type stud welding gun according to the present invention, by pulling the gun trigger,
The piston device is retracted rearwardly by the hydraulic drive and at the same time the hollow body and piston device assembly is moved rearwardly a predetermined distance under the action of the cylinder device. In this state, the stud to be welded is inserted into the stud gripping collet through the central hole of the hollow body by the stud supply device, and at the same time the piston device is driven in the direction toward the tip by the action of the fluid force drive device. The stud is attached to a predetermined position at the tip of the stud gripping collet, and the hollow body and the collet are energized by actuation of the gun trigger, so that the required welding energy flows between the stud and the base metal, and an arc is generated. At the same time that the stud is generated, the hollow body and the piston device are pressed toward the tip with a predetermined pressing force by the action of the spring member, so that the stud is thrust into the surface of the base material and welding is performed.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 schematically shows the configuration of the main parts of a capacitor discharge type stud welding gun according to an embodiment of the present invention, which is implemented as a hand-held welding gun, and 1 is a conductive hollow body having a central hole 1a. ing. A conductive collet 3 is fitted and locked at the tip of the central hole 1a of the hollow body 1 by a collet locking nut 2. Also, at the rear of the hollow body 1 is a cylinder 4.
are arranged coaxially, and a front cylinder socket 5 is attached to the front end of this cylinder 4, and this front cylinder socket 5 is coaxially connected to the rear end of the hollow body 1 by a set screw 6. is fixed.
A rear cylinder socket 7 is attached to the rear end of the cylinder 4. A piston 8 is slidably fitted into the cylinder 4, and a piston rod 1 is attached to the piston 8 by a nut 10 via a spring washer 9.
1 is attached, and the tip of this piston rod 11 extends through the center hole 5a of the front cylinder socket 5 into the center hole 1a of the hollow body 1. The thus assembled assembly consisting of the hollow body 1, the cylinder 4, the front cylinder socket 5 and the rear cylinder socket 7 is housed in a gun housing 12 made of electrically insulating material so as to be slidable in the axial direction. There is. That is, the hollow body 1 has an insulating bushing 13.
and is attached to the front end face of the gun housing 12 by bolts 15 via an end plate 14, and the cylinder 4 is slidably positioned within the gun housing 12 by an annular adjustment member 17 of a spring member 16 mounted on its outer periphery. There is. Annular adjustment member 17
is a threaded portion 12 provided on the inner periphery of the gun housing 12.
The pressing force of the spring member 16 which is threadedly engaged with the spring member 16 and which forces the hollow body 1 forward via the spring stop member 18 and the front cylinder socket 5 can be adjusted. A spring retainer 19 is fixed to the gun housing 12 by bolts 20, and when the front cylinder socket 5 and the hollow body 1 are pushed forward by the action of the spring member 16, the front cylinder socket 5 and the hollow body 1 are moved forward by a predetermined distance. It comes into contact with the shoulder 5b of the butt 5 and acts as a stopper. This protects the spring stopper member 18 from coming into contact with the inner step portion 12b of the gun housing 12 and being damaged.

The hollow body 1 has a central hole 1a as shown in FIG.
A stud introduction passage 1b is formed which communicates with the stud supply pipe 21, and this stud introduction passage 1b deviates from the center hole 1a and extends diagonally rearward, and communicates with the stud supply pipe 21.

The front cylinder socket 5 and the rear cylinder socket 7 each have a pressure fluid introduction part 22 for supplying pressure fluid such as compressed air into the cylinder 4.
23 are provided. Therefore, by supplying pressure fluid into the cylinder 4 from the pressure fluid inlet 22 provided in the front cylinder socket 5, the piston 8 and therefore the piston rod 11 are retracted to the position shown in FIG. , while rear cylinder socket 7
By supplying pressure fluid into the cylinder 4 from the pressure fluid introduction section 23 in the piston 8, the piston 8 and therefore the piston rod 11 are caused to move forward from the position shown in FIG. This forward movement of the piston rod 11 causes the stud supply pipe 2
The stud introduced into the central hole 1a of the hollow body 1 through the stud introduction passage 1b is pushed to a predetermined position in the collet 3.

Also, in FIG. 1, on the outer periphery of the gun housing 12, an assembly consisting of the hollow body 1, the cylinder 4, the front cylinder socket 5, and the rear cylinder socket 7 is installed to the rear during the stud mounting operation. A cylinder device 24 for moving the distance is provided, and this cylinder device 24 is of a type operated by a pressure fluid such as compressed air, and has a cylinder body 25 with two pressure fluid inlets 25a and 25b. The actuator 26 is connected to the pressure fluid introduction part 22 provided in the front cylinder socket 5, and the actuation element 26 is connected to the pressure fluid introduction part 22 provided in the front cylinder socket 5.
is moved axially back and forth along a slot 12c in gun housing 12, thereby causing the assembly to be moved rearwardly a predetermined distance against the spring force of spring member 16. Although not shown, the pressure fluid introduction section 23 also extends to the outside.

Furthermore, a casing 28 containing a cylindrical magnet 27 is attached to the rear end of the gun housing 12, and works together with the cylindrical magnet 27 to hold the assembly at the predetermined position that has been retracted by the cylinder device 24. A suction plate 29 for this purpose is attached to the rear end of the rear cylinder socket 7.

Control of the supply of pressure fluid into the cylinder 4 via the pressure fluid introduction parts 22 and 23, cylinder device 24
The operation control, that is, the supply control of pressure fluid to the pressure fluid inlets 25a and 25b to the cylinder body 25, and the energization control of the cylindrical magnet 27 are provided in a handle 30 integrally attached to the gun housing 12. It can be automatically controlled by a control device (not shown) in response to the activation of the trigger 31. Note that below the handle 30, a gun cable 32 for supplying welding current and a control cable 33 connected to the control device (not shown) are shown. Further, 34 is a leg part planted in the end plate 14,
Three collectors are provided around the collector 3 at approximately equal intervals.

As shown in the figure, an O-ring 35 is installed in the front cylinder socket 5 via an O-ring retaining ring 36, and holds the piston rod 11 in a sealed manner.

In the operation of the illustrated device configured in this way,
By pulling the trigger 31 provided on the handle 30, current flows through the collector 3 and becomes energized. On the other hand, the pressure fluid introduction part 2 in the front cylinder socket 5
Pressure fluid is introduced from 2 to the front of the piston 8 in the cylinder 4, and moves the piston 8 rearward to retract the piston rod 11 (the state shown in FIG. 1).
At the same time, the cylinder device 24 is also activated, and pressure fluid is introduced into the cylinder body 25 through the pressure fluid inlet 25a, moving the actuator 26 rearward to connect the hollow body 1, cylinder 4, and front cylinder socket 5. and rear cylinder socket 7 is retracted. Then, the attraction plate 29 attached to the rear cylinder socket 7 is attracted by the bias of the magnet 27 to hold the assembly in the retracted position. In this state, the stud is inserted into the central hole 1a in the hollow body 1 through the stud supply pipe 21 and the stud introduction passage 1b, which constitute the stud supply device, by the action of, for example, compressed air. Pressure fluid is supplied to the rear side of the piston 8 in the cylinder 4 through the pressure fluid introduction part 23 in the cylinder socket 7, and the piston rod 11 advances forward and is inserted into the central hole 1a in the hollow body 1. The stud that has been placed is pushed toward the collet 3 and installed in a predetermined position within the collet 3. In this case, since the collet 3 itself is in the retracted position, there is no fear that the tip at the tip of the stud will collide with the base material or the like and be crushed when the stud is installed. When the stud is thus installed in a predetermined position, a welding current flows from the gun cable 32 through a not-shown flexible cable inside the gun to the hollow body 1 and the collet 3 to become energized. An arc is generated between the stud and the base material, and the cylinder device 24 moves its actuator 26 forward under the action of the pressure fluid from the pressure fluid inlet 25b, or the cylinder device 24 itself becomes idle and the magnet 27 is activated. By deenergizing, the front cylinder socket 5 and the hollow body 1 are pushed forward by the spring force of the spring member 16, and the stud is plunged into the surface of the base material and welded. By repeating this operation, the studs can be successively welded.

Although the illustrated embodiment is configured as a hand-held device, it is of course possible to implement the device as a stationary welding gun by attaching it to the arm of an industrial robot or the like. Further, in the illustrated embodiment, the assembly consisting of the hollow body 1, the cylinder 4, the front cylinder socket 5, and the rear cylinder socket 7 is moved backward using the cylinder device 24, and by the attraction between the magnet 27 and the attraction plate 29. Although the assembly is configured to be held in the retracted position, if necessary, the magnet 27 and suction plate 29 may be omitted and the assembly may be held in the retracted position by the cylinder device 24. Further, in some cases, the assembly may be retracted and held in the retracted position by the suction action between a magnet and a suction plate instead of an external cylinder device.

The illustrated device can also be used as a contact type welding gun suitable for welding studs made of stainless steel, iron, copper, etc. by shutting off the operation of the external cylinder device and magnet mechanism.

[Effects of the invention] As explained above, the automatically operated stud welding gun according to the invention is configured to automatically perform a series of operations from stud mounting to welding by operating the gun trigger. Therefore, the workability of stud welding can be improved and work efficiency can be greatly increased. In addition, when attaching a stud to the gun, the stud gripping collet itself is held in the retracted position, so unlike conventional devices, when attaching a stud made of aluminum, etc., the tip at the tip of the stud is Crushing can be prevented, thereby ensuring reliable welding of the studs. Furthermore, since the device according to the present invention can be easily applied to not only the gap type but also the contact type, it functions as an all-purpose welding gun regardless of the type of stud, making it extremely useful. be.

[Brief explanation of the drawing]

FIG. 1 is a sectional view schematically showing the structure of a capacitor discharge type stud welding gun according to an embodiment of the present invention, and FIG. 2 is an enlarged sectional view showing the structure of the main part of the apparatus shown in FIG. In the figure, 1: conductive hollow body, 2: locking nut, 3: collet, 4: cylinder, 5: front cylinder socket, 6: set screw, 7: rear cylinder socket, 8: piston, 9: Spring washer, 10:
Nut, 11: Piston rod, 12: Gun housing, 13: Bush, 14: End plate, 15: Bolt, 16: Spring member, 17: Annular adjustment member, 1
8: Spring stopper member, 19: Spring retainer, 20:
Bolt, 21: Stud supply pipe, 24: Cylinder device, 22, 23: Pressure fluid introduction section, 25: Cylinder body, 26: Operator, 27: Magnet, 2
8: Casing, 29: Adsorption plate, 30: Handle, 31: Trigger, 32: Gun cable, 33:
Control cable, 34: Leg, 35: O-ring, 3
6: O-ring retaining ring.

Claims (1)

[Claims for Utility Model Registration] 1. A hollow body which is supported by a frame so as to be slidable in the axial direction and into which a stud gripping collet is fitted in a tightening and loosening manner at the tip, and a lateral part of this hollow body. a stud supplying device that is installed and communicates with the central hole and supplies the stud to be welded from diagonally rearward into the central hole of the hollow body; and an adjustable stud supply device that presses the hollow body toward its tip with a predetermined pressing force. a spring member, a piston device that extends from the rear into the center hole of the hollow body and pushes the stud loaded into the center hole of the hollow body by the stud supply device forward and attaches it to the stud gripping collet; and the piston device. a fluid force drive device that forces the stud rearward when loading the stud and forward when the loaded stud is attached to the stud gripping collet; A capacitor discharge type stud welding gun, comprising a cylinder device for moving an assembly of a piston device a predetermined distance rearward. 2. The capacitor discharge type stud welding gun according to claim 1, wherein the frame body that slidably supports the hollow body is a gun housing fixed to the grip of the gun. 3. The capacitor discharge type stud welding gun according to claim 1, wherein the frame body that slidably supports the hollow body is attached to a gun mounting member of an automatically operated stud welding device.