JP2006272428A - Stud welding gun - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact and lightweight welding gun which has a structure of scraping off the layer of obstacles to welding such as rust on the surface of a base material and for which no motor or the like is needed. <P>SOLUTION: A spiral groove 4 is formed on a spindle 5 installed inside the main body 1 of the welding gun and then, via a spindle guide member 7 that is in slidable contact with the spiral groove 4, the spindle 5 is moved in an axial line direction to be rotated around the axial line. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is mainly a contact type welding gun, which removes a layer of a welding obstacle such as a paint film or rust on the surface of a base material before the start of welding and has a good welding current between the welding stud and the base material. The present invention relates to a welding gun that performs energization and improves welding reliability.

  When a stud is attached to the tip of the welding gun and it is fixed to the base metal surface by welding, if a rust or paint film adheres to the base metal surface, the welding current will not flow easily, There is a risk of lack of reliability.

  In view of this, an apparatus is disclosed in which a shaft is rotated by a motor while a stud is attached to a shaft tip of a welding gun, and a welding obstacle layer such as a rust or a coating film on a base material surface is scraped off by rotation of the stud. No. 079377. Further, Japanese Patent Laid-Open No. 2003-062670 discloses a proposal for reciprocating the drive shaft in the axial direction along with the rotational drive. Japanese Patent Laid-Open No. 2-308046 discloses a proposal for welding after manually rotating a welding gun without using a driving device.

  Stud welding studs are used for various purposes. As an example, Japanese Patent Publication No. 6-72465 uses a stud in order to secure the covering material to the steel material in the fireproof coating method of the steel material. This stud has a dish-like head, and the leg tip is welded to a steel material. Similar studs are also used to secure the insulation to the air duct.

JP 2002-079377 A JP 2003-062670 A Japanese Patent Laid-Open No. 2-308046 Japanese Patent Publication No. 6-72465

  A conventional stud welding apparatus having a function of removing rust, etc., connects an electric motor to a shaft of a welding gun, rotates the stud by driving the motor, and scrapes off the welding obstacle layer. Such a welding apparatus requires a drive motor, requires space, and has a disadvantage that the weight of the welding gun becomes heavy and is unusable. Furthermore, it is necessary to separately provide a switch for driving motor and a trigger switch for welding and use them separately. From this point of view, it is inconvenient.

In addition, although the conventional manual method does not have a problem of increasing the weight of the welding gun, it involves a separate operation of pressing and rotating the welding gun each time welding is performed. In welding, it was difficult to effectively remove the coating film.
SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a welding gun that solves such conventional drawbacks and is light in weight and requires a small number of work steps.

The present invention according to claim 1 comprises a welding gun body (1),
The spindle (5) is provided in the welding gun body (1), has a stud holding means (3) for detachably attaching a stud (2) to be welded to the tip, and has a spiral groove (4) on the outer periphery. When,
A first spring (6) which is provided between the welding gun body (1) and the spindle (5) and biases the spindle (5) toward the tip end in the axial direction;
A spindle guide member (7) guided in a slidable contact with the spiral groove (4) and held non-rotating relative to the welding gun body (1),
By attaching the stud (2) to the tip of the spindle (5) through the stud holding means (3) and pressing the tip of the stud (2) against the base material (11), the first spring (6) is When compressed, the spindle (5) moves rearward relative to the welding gun body (1), and the spindle (5) rotates about its axis via the spindle guide member (7). A stud welding gun configured as described above.

The present invention according to claim 2 is the method according to claim 1,
A cylinder (8) is fitted on the outer periphery of the rear end of the spindle (5), the first spring (6) is interposed between the cylinder (8) and the spindle (5), and the cylinder ( The spindle guide means (7) is provided between 8) and the spindle (5),
A second spring (9) for urging the cylinder (8) toward its tip side is interposed between the cylinder (8) and the welding gun body (1),
Non-rotating guide means (10) that allows the cylinder (8) to move in the axial direction while preventing the cylinder (8) from rotating relative to the welding gun body (1) is provided with the cylinder (8) and the welding gun body ( 1)
A stud welding gun in which the biasing force of the first spring (6) is weaker than that of the second spring (9).

According to a third aspect of the present invention, in the first or second aspect,
The stud holding means (3) is composed of a magnet body (3a) that attracts the head of the stud by magnetic force, and a power cable (12) for supplying welding current is connected to the magnet body (3a),
The power cable (12) is spirally guided around the spindle (5) and spaced apart from the spindle (5) in the axial direction of the spindle (5),
When the stud (2) is pressed against the base material (11), the spiral direction of the power cable (12) increases the diameter of the spiral as the spindle (5) moves relative to the rear and rotates. It is a stud welding gun constituted so that it may become a direction to do.

  In the welding gun of the present invention, the first spring 6 is compressed by pressing the stud holding means 3 attached to the tip of the spindle 5 against the base material 11, so that the spindle 5 is relatively rearward with respect to the welding gun body 1. Since the spindle 5 is configured to rotate around the axis via the spindle guide member 7, the structure is simple and welding obstructions such as rust on the surface of the base material 11 without requiring the power of a motor or the like. The layer 18 can be scraped off by the rotation of the stud 2. Moreover, since the welding obstacle layer 18 on the surface of the base material 11 is removed along with the normal process of pressing the tip of the stud 2 necessary for the welding work of the welding gun against the base material 11, the workability is very good. Then, the welding operation can be performed as it is after the operation of removing the welding obstacle layer 18 or the like.

  This means that, as before, the drive motor is switched on to remove the welding obstacle layer 18, the tip of the stud 2 is attached to the surface of the base material 11 and the welding obstacle layer 18 is dropped, and then the rotation is stopped. Next, a plurality of discontinuous processes of moving to a welding operation are unnecessary. Moreover, since a motor for rotational driving is not required, the welding gun can be reduced in weight and workability can be improved. In addition, the time required for the entire welding operation can be shortened because the manual rotation operation in a separate process is not required as in the conventional type.

  In the above configuration, when the cylinder 8 is provided on the outer periphery of the spindle 5 and the cylinder 8 itself is urged by the second spring 9 and the urging force of the first spring 6 is weaker than that of the second spring 9, the spindle The tip 5c of the stud 2 is pressed against the surface of the base material 11 with a predetermined pressing force of the second spring 9 while smoothly rotating 5 so that the welding operation can be performed reliably.

  In any of the above-described configurations, the stud holding means 3 is constituted by the magnet 3a, the power cable 12 is spirally arranged around the spindle 5, the tip is connected to the magnet 3a, and the spindle 5 is attached to the base material 11. When the spindle 5 is pushed and moved relative to the welding gun main body 1 and rotated relative to the rear, the spiral direction of the power cable 12 is configured to increase its diameter. Can smoothly rotate the spindle 5 without contact between the power cable 12 and the spindle 5 to smoothly remove the welding obstacle layer 18 such as rust on the surface of the base material 11.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of a main part of a welding gun according to the present invention and an enlarged schematic view taken along line BB. FIG. 2 is an explanatory diagram showing a relative movement relationship between the spindle 5 and the spindle guide member 7.

This stud welding gun is of a contact type, and the stud 2 is attached to the stud holding means 3 and energized in a state where the tip 2c is in contact with the base material 11.
In this embodiment, a spindle 5 is housed in a barrel of a welding gun body 1 made of a casing having a pistol-like outer shape so as to be movable in the axial direction. A stud holding means 3 is fixed to the tip of the spindle 5, and the stud 2 is detachably attached to the stud holding means 3.

  The rear end portion of the spindle 5 is fitted with the cylinder 8 on the outer periphery thereof, the rear end of the cylinder 8 is closed by the first spring seat 16, and the first end of the spindle 5 is interposed between the first spring seat 16 and the rear end of the spindle 5. One spring 6 is interposed, thereby urging the spindle 5 toward the tip end side in the axial direction (downward in the figure).

  Further, the cylinder 8 is mounted on the rear plug 21 so as to be movable in the axial direction. A second spring 9 is inserted between the second spring seat 17 at the tip of the rear plug 21 and a stepped portion projecting from the outer periphery of the tip of the cylinder 8, so that the cylinder 8 is connected to the tip side in the axial direction. Is energized. The biasing force of the second spring 9 is formed stronger than that of the first spring 6.

  Next, two spiral grooves 4 are formed on the outer periphery of the spindle 5 so as to intersect each other. The spiral groove 4 may be only one. The rear end portion of the spiral groove 4 is guided so as to be slidably contacted with the protruding strip portion 7 a of the spindle guide member 7. That is, as shown in FIG. 2, the spindle guide member 7 is fitted on the outer periphery of the spindle 5, and a protruding strip portion 7 a is provided on the inner surface of the spindle guide member 7 so as to be slidably fitted into the spiral groove 4.

  The outer periphery of the spindle guide member 7 is fixed to the cylinder 8. As shown in FIG. 1A, the cylinder 8 is rotated in the circumferential direction by a detent guide means 10 comprising a guide piece 20 projecting from the outer periphery and a guide slit 19 formed on the inner surface of the welding gun body 1. While being stopped, it is held movably in the axial direction. (See Fig. 1 (B))

As a result, the spindle guide member 7 itself fixed to the cylinder 8 is also prevented from rotating about the axis through the rotation stop guide means 10. Then, when the ridge 7a is fitted into the spiral groove 4 as shown in FIG. 2, when the spindle 5 is moved rearward in the axial direction as indicated by the arrow with respect to the spindle guide member 7, it is turned clockwise in FIG. Rotate.
Note that the outer periphery of the tip of the cylinder 8 is held by the welding gun body 1 so as to be movable in the axial direction by a bush (not shown).

  The stud holding means 3 fixed to the tip of the spindle 5 is composed of a magnet 3a, and detachably attracts the head 2b of the stud 2 to the tip surface. The tip of the power cable 12 is connected to the magnet 3a so that energization is possible. The power cable 12 is covered with an insulating material on the outer periphery except for the connection end. The power cable 12 has a space on the outer periphery of the spindle 5 and is spirally guided in the axial direction, and is connected to a power supply device (not shown).

  The power supply device is turned on and off via a trigger 14 and a trigger switch 15. That is, when the trigger 14 is pushed in, it is brought into contact with the trigger switch 15 to turn on the circuit of the power supply device. Thereby, a welding current is supplied to the stud 2 through the power cable 12 and the magnet 3a.

  In FIG. 5, the power cable 12 changes from a solid line state to a chain line state as the spindle 5 rotates and moves. That is, the spindle 5 is raised relative to the welding gun body 1 in the drawing by pressing the tip of the tip 2c of the stud 2 against a base material not shown in the drawing. At the same time, it is guided by the ridge 7a of the spindle guide member 7 and rotates.

  The distal end of the power cable 12 is attached to the stud holding means 3 and rotates with the rotation of the stud holding means 3 accompanying the rotation of the spindle 5 and moves upward in the axial direction in FIG. This is because the spiral direction of the power cable 12 is pre-twisted in a direction that expands with the rotation of the stud holding means 3. Thereby, the power cable 12 and the spindle 5 can be prevented from coming into contact with each other, and smooth rotation of the spindle 5 can be ensured. In other words, when the screwing direction of the power cable 12 is reversed, the radius of the power cable 12 is reduced by the rotation of the stud holding means 3 and wound around the spindle 5.

(Function)
Next, an example of a method for welding the stud 2 to the base material 11 with the stud welding gun of the present invention will be described. The head 2b of the stud 2 is attracted to the magnet 3a made of a permanent magnet. In the stud 2, the tip 2c of the shaft 2a is formed as shown in FIGS. That is, the tip 2c is formed as a knife edge having a V-shaped cross section. The head 2b of the stud 2 is attracted to the magnet 3a. In this state, the tip 2c of the stud 2 is pressed against the base material 11 as shown in FIG.

  In this example, the surface of the base material 11 is covered with a welding obstacle layer 18 such as rust or a coating film. Therefore, the welding gun body 1 is pushed into the base material 11 side. Then, in FIG. 1, the spindle 5 moves upward relative to the welding gun body 1 against the first spring 6. Then, along with the movement, the ridge 7a of the spindle guide member 7 and the spiral groove 4 are slidably guided, so the spindle 5 itself rotates around its axis and rotates the stud 2. Then, the welding obstacle layer 18 is cut into a circle as shown in FIG.

Therefore, by pulling the trigger 14 in FIG. 1, it is brought into contact with the trigger switch 15 to turn on the circuit of the power supply device. Energization is performed between the tip 2c of the stud 2 and the base material 11 via the power cable 12, and the tip 2c is melted to form a weld 13 between them as shown in FIG. 4C.
At this time, the tip end portion 2c of the stud 2 and the surface of the base material 11 are kept in contact with each other by the biasing force of the second spring 9 and the biasing force of the first spring 6.

The principal part longitudinal cross-sectional view of the stud welding gun of this invention and its BB arrow cross-sectional schematic diagram. Explanatory drawing which shows the relationship between the spindle 5 and the spindle guide member 7 of the welding gun of this invention. An example of the stud 2 attached to the front-end | tip of the welding gun of this invention is shown, (B) is the B section enlarged front view, (C) is the same side view. Explanatory drawing which shows the effect | action of the stud welding gun of this invention. Explanatory drawing of the power cable 12 at the time of rotation of the spindle 5 of the welding gun.

Explanation of symbols

1 Welding gun body
1a End cover
1b Handle 2 Stud
2a Shaft
2b head
2c Tip

3 Stud holding means
3a magnet
4 Spiral groove
5 spindle
6 First spring
7 Spindle guide member
7a Projection

8 cylinders
9 Second spring
10 Non-rotating guide means
11 Base material
12 Power cable
13 Welded part
14 Trigger

15 Trigger switch
16 First spring seat
17 Second spring seat
18 Welding obstacle layer

19 Guide slit
20 Guide pieces
21 Rear plug
22 Insulation

Claims (3)

The welding gun body (1),
The spindle (5) is provided in the welding gun body (1), has a stud holding means (3) for detachably attaching a stud (2) to be welded to the tip, and has a spiral groove (4) on the outer periphery. When,
A first spring (6) which is provided between the welding gun body (1) and the spindle (5) and biases the spindle (5) toward the tip end in the axial direction;
A spindle guide member (7) guided in a slidable contact with the spiral groove (4) and held non-rotating relative to the welding gun body (1),
By attaching the stud (2) to the tip of the spindle (5) via the stud holding means (3) and pressing the tip of the stud (2) against the base material (11), the first spring (6) is moved. When compressed, the spindle (5) moves rearward relative to the welding gun body (1), and the spindle (5) rotates about its axis via the spindle guide member (7). Stud welding gun configured as follows. In claim 1,
A cylinder (8) is fitted on the outer periphery of the rear part of the spindle (5), the first spring (6) is interposed between the cylinder (8) and the spindle (5), and the cylinder (8) The spindle guide member (7) is provided between the spindle and the spindle (5),
A second spring (9) for urging the cylinder (8) toward its tip side is interposed between the cylinder (8) and the welding gun body (1),
Non-rotating guide means (10) that allows the cylinder (8) to move in the axial direction while preventing the cylinder (8) from rotating relative to the welding gun body (1) is provided with the cylinder (8) and the welding gun body ( 1)
A stud welding gun in which the urging force of the first spring (6) is weaker than that of the second spring (9). In claim 1 or claim 2,
The stud holding means (3) is composed of a magnet body (3a) that attracts the head of the stud by magnetic force, and a power cable (12) for supplying welding current is connected to the magnet body (3a),
The power cable (12) is spirally guided around the spindle (5) and spaced apart from the spindle (5) in the axial direction of the spindle (5),
When the stud (2) is pressed against the base metal (11), the direction of the spiral of the power cable (12) increases the diameter of the helix as the spindle (5) moves and rotates backward. Stud welding gun configured to be in the direction to do.

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