JPH0244940Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a welding gun used in capacitor discharge type stud welding, which uses the discharge energy of a capacitor to weld a stud to a base metal.

Conventional technology Welding guns of various structures have been used for capacitor discharge type stud welding, but in general, as shown in Figure 6 of the drawings and Japanese Utility Model Publication No. 57-50140, conventional welding guns are used. A welding gun for capacitor discharge type stud welding has a cylindrical body with a chuck that extends axially inside the housing and receives the stud to be welded at the tip, and the cylindrical body is always held in the direction of the tip. and a connecting current-carrying member for connecting a welding cable from a welding capacitor of a welding power source to flow a welding current between the stud to be welded and the base metal,
The welding current is caused to flow between the base metal and the stud through the chuck by the operation of the trigger switch, so that the stud is pressed against the base metal and welded.

Problems to be solved by the invention In conventional welding guns as shown in the above-mentioned Utility Model Publication No. 57-50140 and as shown in Fig. 6, the control member and spindle A (Fig. 6) forming a cylindrical body are connected to the bearing B (Fig. 6). 6), it must be made of a hard material such as iron, and therefore the welding cable from the welding power source must be constructed as disclosed in Publication No. 57-50140. It is connected either directly to a chuck attached to the tip of the control member or to chuck D via a flexible cord C as shown in FIG. However, in the former case, the welding cable gets in the way, resulting in poor workability, and in the latter case, the flexible cord C repeatedly bends and stretches in response to the repeated sliding motions of the spindle A, causing the insulation coating to tear, creating the risk of sparks and, in some cases, electric shock. can occur. In each case, the welding cable or cord C is removably connected by suitable fastening means to facilitate disassembly and repair of the device. As a result, the connections become loose and prevent proper electrical conduction, which can result in heat generation and spark generation.

The present applicant has proposed an improved welding gun in which the chuck to which the stud to be welded is attached is energized through the cylindrical body, in U.S. Pat. (Refer to Publication No. 82777)
proposed in.

Therefore, the purpose of the present invention is to provide a method for firmly and removably connecting a welding cable and a cylindrical body in a method of energizing the chuck through the cylindrical body, taking into account the problems of the conventional method of energizing the chuck as described above. The goal is to make it possible.

Means for Solving the Problems In order to achieve the above object, the welding gun according to the present invention has a cylindrical body that extends slidably in the axial direction within the housing and is made of a conductive material, and connects the welding cable. The connecting current-carrying member comprises a connecting terminal member that is threadedly engaged with the cylindrical body, and this connecting terminal member is provided with a slit extending in a direction transverse to the screw hole, and by tightening the terminal of the welding cable to the connecting terminal member. The present invention is characterized in that the threaded hole portion of the connection terminal member is deformed through the slit to firmly maintain the threaded engagement with the cylindrical body.

Function The welding gun according to the present invention configured as described above has the following features:
By connecting the terminal of the welding cable to the connecting terminal member, the slit provided therein is deformed, and the screw hole screwed into the cylindrical body is thereby deformed relative to the cylindrical body, causing the screw engagement to occur. can be held firmly. The connecting terminal member may be designed in any manner as long as it deforms by widening or narrowing the slit cut across the screw hole when attaching the terminal of the welding cable. By doing so, there will be no loosening at the connection between the welding cable and the cylindrical body, ensuring good electrical conduction, and preventing the risk of spark generation and heat generation.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 5 of the drawings.

Figures 1 and 2 show the overall structure of the welding gun according to the present invention, in which 1 is a cylindrical housing with a cap 2 removably attached to its rear end, and a handle 3 attached to the cylindrical housing 1. The handle 3 is equipped with a trigger button 4. A cylindrical body 5 made of a conductive material is coaxially supported within the cylindrical housing 1 by a bearing 6 so as to be slidable in the axial direction. The inner circumferential surface of the tip of the cylindrical body 5 is denoted by 5.
As shown by a, it is formed into a tapered shape that widens outward, and is adapted to receive the chuck holding member 7. This chuck holding member 7 is made of a conductive material, and its outer peripheral surface is the tapered inner peripheral surface 5.
It is formed into a conical shape corresponding to a, and has one longitudinally extending crack (not shown) and two longitudinally extending narrow grooves (not shown). A chuck 8 is inserted into this chuck holding member 7 and is secured by tightening a cap nut 9, which may be made of a plastic material, for example, and which constitutes a tightening nut, onto the tip of the cylindrical body 5, as shown in FIG. It is held in close contact with the cylindrical body 5 via the chuck holding member 7 over a relatively wide contact area. Therefore, the chuck 7 can be easily attached or detached by simply turning the cap nut 9 by hand.

To explain the structure in which the cylindrical body 5 is slidably supported by the bearing 6, as shown in FIGS. 1 and 3, insulating bushes 10 and 11 are mounted around the cylindrical body 5. A bearing inner ring 12 is mounted on the bearing 11. On the other hand, the bearing 6 is fixed within the cylindrical housing 1 by tightening holding members 13 and 14 to the front end surface of the cylindrical housing 1 with three bolts 15. With this configuration, the bearing inner ring 12 is electrically insulated from the cylindrical body 5, and smooth and accurate axial sliding of the cylindrical body 5 can be ensured.

Further, in FIG. 1, reference numeral 16 denotes a connecting terminal member for connecting a terminal 17a of a welding cable 17 from a welding power source (not shown) to the cylindrical body 5, and this terminal member 16 has a cylindrical shape as shown in FIGS. It is provided with a screw hole 16a that screws into the shaped main body 5 and a screw hole 16a that fixes the terminal 17a of the welding cable 17 with a bolt 18, and slits 16c and 16d are provided across each screw hole 16a and 16b, respectively. It is formed. Therefore, the terminal 17a of the welding cable 17
By tightening and fixing the screw to the connecting terminal member 16 with the bolt 18, the slit 16d narrows while the slit 16c widens, so that the screw locking portion is deformed and is held tightly to prevent loosening. As a result, heat generation and spark generation can be prevented, and good current conduction can be guaranteed.

Furthermore, as shown in FIG. 1, a spring 19 is mounted on the cylindrical body 5 between two spring seats 20 and 21, which press the cylindrical body 5 toward its distal end. One of the spring seats 21 can be slid along the cylindrical body 5, i.e. this spring seat 21 is slid axially by a spring adjustment screw 22 screwed into the rear end of the cylindrical housing 1, and the spring 19 The repulsive force of the stud, that is, the pressure applied to the stud can be adjusted. The spring adjusting screw 22 can be set to a desired pressure by aligning it with knurled scales provided at predetermined intervals around the outer periphery of a graduated stop member 23 attached to the rear end of the cylindrical body 5. can.

A graduated stop member 23 mounted on the rear end of the tubular body 5 also retains within the tubular body 5 a stud positioning member 24 which extends within the tubular body 5. The stud position adjustment member 24 includes a front stud receiving pin 24a and an intermediate tubular body 24 that are threadedly engaged with each other.
b and a rear adjustment pin 24c, and the intermediate tubular body 24b is prevented from rotating by engaging the key 24d with a slot 5b provided in the cylindrical body 5, so that the rear end knob 24
By rotating e, the stud receiving pin 24
The position of a can be adjusted. Note that the first and second
In the figure, 25 is a guide leg, and in the illustrated embodiment, three guide legs are provided, and 26 is a protective cover. Further, in the illustrated embodiment, the shape and material of the constituent elements of each part can be appropriately selected.

Effects As explained above, according to the present invention, when the terminal of the welding cable is attached and tightened, the screw engagement part of the connecting terminal member that connects the terminal of the welding cable to the cylindrical body is deformed and becomes rigid. Since they engage with each other, the connection is held without loosening, and as a result, good current conduction can be ensured without heat generation or spark generation. Furthermore, since the connecting terminal member is made of a single piece, the structure can be simplified and miniaturized.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing an embodiment of the welding gun according to the present invention, Fig. 2 is a front view of the welding gun of Fig. 1, Fig. 3 is a diagram showing the constituent elements, and Figs. 4 and 5 are separate. FIG. 6 is an end view and a sectional view showing the components of the conventional welding gun. In the figure 1... Housing, 5... Cylindrical body, 16
... Connection terminal member, 17 ... Welding cable, 17
a...Terminal.

Claims (1)

[Scope of utility model registration request] A cylindrical body having a chuck which extends axially within the housing and receives a stud to be welded at the distal end thereof, a spring always forcing the cylindrical body toward its distal end, and a spring to be welded. It has a connecting current-carrying member to which a welding cable from a welding capacitor of a welding power supply device is connected in order to flow a welding current between the stud and the base metal. In a welding gun for capacitor discharge type stud welding in which welding current is applied between the studs and the stud is pressed against the base metal, the cylindrical body is made of a conductor, and the connecting current-carrying member is connected to the cylindrical body. It consists of a connecting terminal member that is screwed together, and this connecting terminal member has a slit extending in a direction transverse to the screw hole, and by fixing the terminal of the welding cable to the connecting terminal member, the connecting terminal member is formed into the above-mentioned cylindrical shape. A welding gun for capacitor discharge type stud welding, characterized by being firmly held against the main body.