KR101096298B1 - Liftng module for stud welding gun - Google Patents

Abstract

PURPOSE: A lifting module for a stud welding gun is provided to remove time delay by moving a gun body backward and forward through a rubber pipe of an air clamping unit. CONSTITUTION: A lifting module for a stud welding gun comprises a lifting bar(210), an air clamping unit(220), a solenoid(230), a slider(240), and a lifting spring(250). The front end of the lifting bar is fixed to the rear end of a gun body(100), and the rear end is rearward extended. The air clamping unit is slidably formed and has a rubber pipe to surround the outer surface of the rear end of the lifting bar. When compressed air is injected into the air clamping unit, the inner surface of the rubber pipe is inward inflated. The solenoid is fixed to the rear of the air clamping unit and generates a magnetic field. The front end of the slider is fixed to the rear end of the air clamping unit and has a magnetic body inserted into a bobbin(231) of the solenoid. The lifting spring supplies elastic force from the rear to the front of the slider.

Description

Lifting module of stud welding gun {LIFTNG MODULE FOR STUD WELDING GUN}

The present invention provides a stud welding gun for automatically welding a stud to a base material, which moves the gun body back and forth to contact and detach the stud from the base material while ensuring a constant arcing distance between the stud and the base material when melting the stud into the arc. A lifting module for a stud welding gun.

Stud welding refers to welding by generating an arc by using a stud or the like as an electrode, and compressing it to a base material in a molten state.

Here, studs are typically relatively short lengths of steel rods threaded at one end, fused or welded to the base material, such as a plate or part, with no threaded ends, and threads on the threaded side to join other plates or components. Point out what you did. It is also called a stud bolt in that a thread is formed at one side.

As such studs are consumed in large quantities, especially in automobile assembly processes, various types of stud welding guns for automatically welding studs have been developed. The stud welding gun can continuously weld the stud to each of a plurality of preset points on the base material while moving relatively horizontally with respect to the base material which is usually flat plate shape. Usually, the base material is placed horizontally so that the stud welding gun is installed upright and upright, and the lifting and lowering is performed by holding the stud on the lower chuck of the stud welding gun and then raising or lowering it. It is preferable that the front and rear operation of the base material of the forward or backward of the welding gun is preferable to the lifting by mounting the robot arm in three axes.

For the configuration of the stud welding gun according to the prior art (Patent Document 1), referring to FIG. 1, the gun base 10, the cylindrical housing 20 fixed by the gun base 10, and the housing ( 20 is provided in the inside of the gun body 30 is provided so as to be able to move forward and backward and slide back and forth by pneumatic pressure, and the front of the gun body 30 and the pushing body ( Adapter 40 is provided with a chuck 41 for holding the stud according to the advance of the 31, and the lifting module 50 is installed in the rear of the gun body 30 to advance or reverse the gun body 30 And a main spring 60 interposed between the gun body 30 and the lifting module 50.

Referring to FIG. 2, a stud welding process using a stud welding gun is carried out in order of 1) contact, 2) backward and induced arc generation, 3) main arc generation, and 4) forward compression.

First, before proceeding with the contact process 1), the stud is automatically supplied into the adapter 40 through the stud supply unit 70, and the pushing rod 31 provided in the gun body 30 is pneumatically applied. Move forward. That is, the gun body 30 functions as a double acting cylinder among the pneumatic cylinders with respect to the pushing rod 31. As the pushing rod 31 moves forward, the stud is held by the chuck 41 of the adapter 40, and the stud is brought into contact with the base material while the stud welding gun approaches the base material.

1) The first contact state of the stud to the base material is a state in which the pushing rod 31 is advanced toward the front of the gun body 30, and the tip of the pushing rod 31 is in contact with the rear end of the stud. Although there are some errors in the contents of the detailed description of the invention of Patent Document 1, in this case, the forward and backward strokes by the pneumatic pressure of the pushing rod 31 are completely moved strokes regardless of whether the contact surface of the base material to which the stud is in contact is flat or embossed. same. However, if there is embossing on the contact surface of the base material, the forward stroke by the pneumatic pressure of the pushing rod 31 is completely made, and the main spring 60 is compressed while the gun body 30 itself is pushed backward by the height of the embossing. will be. That is, the configuration for compensating the embossing height on the contact surface of the base material is made by the main spring 60, not by the lifting module 50 to be described later.

2) Lifting module 50 is operated from the process of backward and induced arc generation. If there is a gap between the stud and the base material before the arc is generated, the arc does not occur. However, if the main arc is generated immediately in contact with the stud and the base material, the stud is not melted properly and the stud is welded to the base material as bad. Therefore, the induced body is first generated in the contact state, and the gun body 30 is operated by the lifting module 50 in order to make the optimum arc generation distance at which the melting of the stud is optimized by the main arc, which will be described later. The optimum arc generation distance at this time is a widely known distance based on a number of experiments and experiences is about 1.5mm, the lifting module 50 is to reverse the gun body 30 by 1.5mm. The induced arc current is about 20 A to maintain an arc between the stud and the base material before generating the main arc, which will be described later.

3) The main arc generation process is performed in a state in which the gun body 30 is reversed by the lifting module 50 after the induced arc is generated by 1.5 mm, that is, the optimum arc generation distance. At this time, the main arc current flows from 200A to 1800A. As the main arc is generated, a part of the contact surface of the base material facing the contact surface of the stud is melted.

4) In the pressing process by the advance, the main arc flows for a predetermined time, and the lifting module 50 is operated by moving the lifting module 50 in the state where the contact surface of the stud and the base material is molten, and the molten contact surface of the stud becomes the base material. Welding is completed by welding with the contact surface.

Stud welding in the above process is carried out in a unit of a few msec or hundreds of msec, the welding part burns or melts due to a slight delay during the forward or backward operation of the gun body 30 by the lifting module 50 may cause a defect On the contrary, it is not easy to melt properly, which leads to welding defects.

As shown in FIG. 3, the lifting module 50 according to the related art (Patent Document 1) includes a clutch bar 51 having a taper 51a formed at a front end thereof, and a solenoid 52 for advancing the clutch bar 51 forward and backward. ), The clutch ball 53 which contacts the outer peripheral surface of the taper 51a of the clutch bar 51 and flows in the outer circumferential direction of the taper 51a as the clutch bar 51 moves forward and backward, and the inner peripheral surface of the clutch bar 51 is once It is arranged to surround the clutch ball 53 and the other end comprises a coupling 54 coupled to the rear end of the gun body (30). When the current is applied to the solenoid 52, the clutch bar 51 is reversed, and the clutch ball 53 moves in the outer circumferential direction to press the inner circumferential surface of the coupling 54 so that the gun body coupled with the coupling 54 ( 30) to reverse. On the contrary, when the current is cut off from the solenoid 52, the clutch ball 51 moves forward by the spring force of the lifting spring 55, the clutch ball 53 moves inward, and the pressure is released from the inner circumferential surface of the coupling 54. Body 30 is also advanced.

Lifting module 50 according to the prior art of the above configuration, the first by moving the clutch bar 51 forward or backward in accordance with the application of the current of the solenoid 52 to move the clutch ball 53 to the outside or inside the gun body Pressing or releasing the coupling 54 to which the 30 is coupled has a problem in that a welding defect occurrence rate is considerably high due to time delay when the gun body 30 moves forward or backward.

Second, since the optimum arc generation distance is very small (1.5mm) distance, the gun body 30 is moved with the coupling 54 being pushed by the clutch ball 53 according to the movement of the clutch bar 51. It is difficult to secure the movement distance of 30, and furthermore, the movement distance of the gun body 30 is not the same each time, so there is a problem that it is difficult to expect the continuity of the quality.

Third, due to the intermetallic wear between the taper 51a, the clutch ball 53 and the coupling 54 of the clutch bar 51 as the most fatal problem, the problem of accuracy of time delay and moving distance described above is further intensified. There is a problem that a large accident occurs frequently during arc welding because the chip caused by metal wear is stopped.

Korea Patent Registration No. 10-0729082

The object of the present invention devised to solve the above problems is to eliminate the time delay while ensuring a constant moving distance at all times during the forward or backward movement of the gun body to secure the optimum arc generation distance, so that precise and accurate control is possible The present invention provides a lifting module for a stud welding gun that can improve quality continuity.

Other objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments with reference to the accompanying drawings.

In order to achieve the above object, the lifting module of the stud welding gun according to the present invention is installed at the rear of the gun body, and the lifting module of the stud welding gun for moving the gun body forward or backward, the front end and the rear end of the gun body Fixedly coupled, the rear end of the lifting bar extending rearward, slidably installed by the forward and backward distance of the gun body, a rubber tube is provided to surround the outer peripheral surface of the rear end of the lifting bar, the injection of compressed air of the rubber tube The inner peripheral surface bulges inward to press the outer peripheral surface of the lifting bar to grip the air holding portion, and the rear of the air holding portion fixedly installed, the coil is wound around the bobbin coil is supplied with power to generate a magnetic field And, the front end is fixedly coupled to the rear end of the air gripping portion, the magnetic material provided in the rear end is the solenoid A is inserted into the bobbin comprises a lifting spring for providing a spring force on the rear portion of the slider to move rearwardly along the power-on of the solenoid, the sliding forward.

In addition, the rubber tube of the air gripping portion is provided with a flange protruding in the circumferential direction, respectively, at the front and rear ends, and the stepped surface is formed such that the flanges projecting at the front and rear ends of the rubber tube, respectively, on the front and rear surfaces, respectively. A front air coupled to the front and rear surfaces of the air cylinder so that the rubber tube is inserted into the inside and presses the cylindrical air cylinder through which the air inlet hole penetrates from the outer circumferential surface to the inner circumferential surface and the flange protruding from the front and rear ends of the rubber tube. It further comprises a cover and a rear air cover.

In addition, a ring-shaped anti-rotation ring interposed between the air gripping portion and the solenoid and fixedly coupled to the solenoid and having an insertion hole formed on a surface facing the air gripping portion, and the anti-rotation ring of the rear air cover. It characterized in that it further comprises an anti-rotation projection formed to protrude to slide is inserted into the insertion hole of the anti-rotation ring on the side facing.

The apparatus may further include a spring cover interposed between the slider and the lifting spring to provide a spring force of the lifting spring to the slider, and a guide cover fixed to the rear of the solenoid to guide the front and rear sliding of the spring cover. It is done.

The lifting module of the stud welding gun according to the present invention always moves the gun body forward and backward through the rubber tube of the air holding portion inflated by the compressed air during the forward or backward movement of the gun body to secure the optimum arc generation distance. It eliminates time lag and secures precise and accurate control, improving quality continuity.

In addition, each of the air cylinder, front and rear air cover and the rubber tube of the air holding unit is tightly coupled so that compressed air does not leak, as well as the ease of assembly can be secured to simplify the production process.

In addition, by the anti-rotation ring and the anti-rotation projection to prevent the self-rotation of the air gripping portion by the vibration during repeated stud welding, it is possible to operate the gun body forward and backward more precisely and accurately.

1 is a side cross-sectional view showing a stud welding gun according to the prior art,
2 is a graph showing a general stud welding process in order over time,
3 is a side cross-sectional view showing main parts of the lifting module of the embodiment of FIG. 1;
Figure 4 is a side cross-sectional view showing an embodiment of a lifting module of the stud welding gun according to the present invention,
5 and 6 are side cross-sectional views showing the operation of the embodiment of Figure 4,
7 is a perspective view illustrating a lifting bar, an air gripping portion, an anti-rotation ring, and a solenoid in the embodiment of FIG. 4;
FIG. 8 is an exploded perspective view of an air gripping part in the embodiment of FIG. 7;
9 is a perspective view illustrating an air gripping portion, an anti-rotation ring, and an anti-rotation protrusion of the embodiment of FIG. 7.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the lifting module of the stud welding gun according to the present invention.

Lifting module 200 of the stud welding gun according to the present invention is a lifting bar 210, air holding unit 220, solenoid 230, slider 240 and lifting spring 250 as shown in Figure 4 to 9 It includes, the anti-rotation ring 260, anti-rotation protrusion 270, the spring cover 280, may further include a guide cover 290. In addition, the air holding unit 220 may be composed of a rubber tube 221, an air cylinder 222, a front air cover 223 and a rear air cover 224.

First, another general configuration and operation of the stud welding gun including the lifting module 200 according to the present invention is similar to the prior art described in the background section, but the lifting module 200 for moving the gun body 100 forward or backward. ) There is a difference in the composition. That is, referring to FIG. 2, the lifting module 200 of the present invention operates in a state in which the stud gripped to the chuck is in contact with the base material according to the movement of the stud welding gun. The height difference is compensated for by the compression of the main spring 300 of FIG. 4, regardless of whether the contact surface of the base material is flat or embossed. Then, in consideration of the compensated height difference, the operation of the lifting module 200 according to the present invention reverses and advances the gun body 100.

Lifting module 200 according to the present invention is installed in the rear of the gun body 100, as shown in Figure 4 to 6 to advance or reverse the gun body 100. The gun body 100 is installed to slide back and forth inside the housing 400 of the stud welding gun, and is connected to the lifting module 200 through the lifting bar 210.

That is, the lifting bar 210 has a cylindrical rod shape, the front end is fixedly coupled to the rear end of the gun body 100, the rear end is extended to the rear. The rear end of the lifting bar 210 extending rearward is moved by the gun body 100 with the gun body 100 while being bitten or released by the air gripping portion 220 to be described later.

As shown in FIGS. 4 to 6, the air gripping portion 220 is slidably installed by the forward and backward distances of the gun body 100, and a rubber tube 221 is provided to surround the outer circumferential surface of the lifting bar 210. By the injection of compressed air, the inner circumferential surface of the rubber tube 221 swells inward and presses and grips the outer circumferential surface of the rear end of the lifting bar 210. That is, the lifting bar 210 is inserted into the rubber tube 221, and before the compressed air is injected into the rubber tube 221, the lifting bar 210 slides back and forth without interference, but the compressed air is compressed in the rubber tube 221. When injected, the inner circumferential surface of the rubber tube 221 swells inward to press and grip the outer circumferential surface of the rear end of the lifting bar 210.

For example, in a state in which the base material and the stud are in contact with the movement of the stud welding gun of FIG. 2, compressed air is not injected into the rubber tube 221 of the air gripping portion 220, and the lifting bar 210 is moved back and forth without interference. . At this time, if the base material is embossed, the gun body 100 and the lifting bar 210 will be reversed by the height of the embossing, the main spring 300 will be compressed. Next, in order to retract the studs by the optimum arc generation distance from the base material, the gun body 100 and the lifting bar 210 should be retracted, so that compressed air is injected into the rubber tube 221 of the air gripping portion 220 and the rubber tube 221. Swells the inner circumferential surface of the inner side to press the outer peripheral surface of the rear end of the lifting bar 210 to grip.

Detailed configuration of the air holding unit 220, as shown in Figures 4 to 6 and 8 will be composed of a rubber tube 221, air cylinder 222, front air cover 223 and rear air cover 224. Can be. The rubber tube 221 is provided with flanges 221a protruding in the circumferential direction, respectively, at the front and rear ends, and the air cylinder 222 has a cylindrical shape, and the flanges 221a protruded at the front and rear ends of the rubber tube 221 at the front and rear surfaces, respectively. The stepped surface 222a is formed so that each is joined so that the rubber tube 221 is inserted therein, and the air inlet hole 222b is formed through from the outer circumferential surface to the inner circumferential surface. That is, the rubber tube 221 is inserted into the air cylinder 222, the front and rear flange 221a of the rubber tube 221 is respectively installed on the front and rear step surface 222a of the air cylinder 222.

At this time, the flange 221a of the rubber tube 221 is fixed while being pressed through the front air cover 223 and the rear air cover 224 respectively coupled to the front and rear surfaces of the air cylinder 222. As the rubber tube 221 is a rubber material as the name is pressed by the air cylinder 222 and the front and rear air cover 223, 224 is pressed while being compressed air is injected through the air inlet hole 222b of the air cylinder 222 Is sealed without leaking. Each configuration of the air gripping portion 220 has a structure that can lead to easy assembly and at the same time close coupling.

When holding the lifting bar 210 coupled to the gun body 100 by the air gripping portion 220 configured as described above, the air gripping portion 220 is reversed so that the optimum arc generation distance as shown in FIG. 2. Hold the studs as long as the gun body 100 should be retracted. This is achieved through the solenoid 230, the slider 240 and the lifting spring 250 to be described later.

The solenoid 230 is fixed to the rear of the air holding unit 220, as shown in Figures 4 to 6, the coil 232 is wound around the bobbin 231 is supplied with power to generate a magnetic field. In addition, the front end of the slider 240 is fixedly coupled to the rear end of the air holding portion 220, the magnetic material provided in the rear end is inserted into the bobbin 231 of the solenoid 230 of the solenoid 230 It moves backward when power is applied. The rearward movement of the slider 240 should be moved forward, and maintain the forward movement of the slider 240 so that the rearward movement of the slider 240 only occurs when power is applied to the solenoid 230. In order to provide a spring force from the rear of the slider 240 to the front is provided with a lifting spring 250.

That is, the slider 240 is fixedly coupled to the air gripping portion 220 so as to slide back and forth together, usually as shown in Figure 4 by the spring force of the lifting spring 250, the slider 240 and the air wave Branch 220 is moved to the front. At this time, as shown in Figure 2, the induced arc is generated in the state in which the stud and the base material is in contact, as shown in Figure 5 compressed air is injected into the air holding unit 220, the rubber tube 221 swells The rear end of the lifting bar 210 coupled with the body 100 is gripped. As shown in FIG. 6, power is applied to the solenoid 230 to generate a magnetic field, and the magnetic body of the slider 240 moves backward while overcoming the spring force of the lifting spring 250 by the magnetic force. Accordingly, the slider 240, the air gripping portion 220, the lifting bar 210, and the gun body 100 move backward by approximately 1.5 mm, which is an optimal arc generation distance, and are coupled to the tip of the gun body 100. The stud bited by the adapter (not shown) will retract from the base material by the optimal arc generation distance. Subsequently, when the contact surface of the stud and the base material is melted while the main arc is generated as shown in FIG. 2, the power is turned off to the solenoid 230 as shown in FIG. 5 and the slider (by the spring force of the lifting spring 250) is removed. 240, the air holding unit 220, the lifting bar 210 and the gun body 100 moves forward. In addition, when the power supply to the solenoid 230 is cut off and the compressed air injected into the air holding unit 220 is discharged to the outside as shown in FIG. 4, the inflated inner circumferential surface of the rubber tube 221 is elastically restored and a lifting bar. As the outer peripheral surface of the rear end of 210 is released from the rubber tube 221, the spring bar of the main spring 300 at the time of initial contact is acted on, so that the lifting bar 210 and the gun body 100 are above the optimum arc generation distance. Will move forward. Thereby, the molten contact surface of the stud is pressed against the molten contact surface of the base material to complete the welding.

On the other hand, the housing 400 of the stud welding gun is a cylindrical shape, each configuration provided therein also has a cylindrical or cylindrical shape. In particular, the air gripping portion 220 also has a cylindrical shape, and if it rotates itself with respect to the central axis in the longitudinal direction, there is a possibility of slippage during pressing on the lifting bar 210 of the rubber tube 221, which is precise and accurate distance and This can adversely affect time control. Accordingly, the anti-rotation ring 260 and the anti-rotation protrusion 270 may be further included as shown in FIGS. 4 to 6 and 9 to prevent axial rotation of the air gripping portion 220 in the longitudinal direction.

That is, the anti-rotation ring 260 is interposed between the air gripping portion 220 and the solenoid 230 in a ring shape as the name thereof is fixedly coupled to the solenoid 230, and faces the air gripping portion 220. Insertion holes 261 are formed in the viewing surface. At this time, the anti-rotation protrusion 270 is formed to protrude on the rear air cover 224 of the air gripping portion 220, the anti-rotation on the surface facing the anti-rotation ring 260 of the rear air cover 224 It is inserted into the insertion hole 261 of the ring 260 is formed to protrude so as to slide. Accordingly, when the anti-rotation protrusion 270 slides while being inserted into the insertion hole 261 of the anti-rotation ring 260, the air gripping portion 220 only slides back and forth without rotating about the longitudinal axis. .

In addition, when the slider 240 is provided with the spring force forward by the lifting spring 250, the lifting spring 250 needs to be the tension spring and the compression force generated only before and after as the coil spring. 4 to 6 may further include a spring cover 280 and a guide cover 290 for this purpose.

That is, the spring cover 280 is interposed between the slider 240 and the lifting spring 250 to provide the spring force of the lifting spring 250 to the slider, wherein the guide cover 290 is the spring cover 280 In order to guide the front and rear sliding of the solenoid 230 is fixedly installed. Accordingly, the lifting spring 250 is in a state surrounded by the spring cover 280, and of course, the spring force of the lifting spring 250 is provided to the slider 240 via the spring cover 280. Front and rear sliding of the spring cover 280 surrounding the lifting spring 250 can be easily guided through the guideline of the spring cover 280.

The embodiments of the present invention described above and illustrated in the drawings should not be construed as limiting the technical idea of the present invention. The protection scope of the present invention is limited only by the matters described in the claims, and those skilled in the art can change and change the technical idea of the present invention in various forms. Therefore, such improvements and modifications will fall within the protection scope of the present invention, as will be apparent to those skilled in the art.

100: Gunbody
200: lifting module
210: lifting bar
220: air holding part
221: rubber tube 221a: flange
222: air cylinder
222a: step surface 222b: air inlet hole
223: front air cover 224: rear air cover
230: solenoid
231 bobbin 232 coil
240: slider
250: lifting spring
260: anti-rotation ring 261: insertion hole
270: anti-rotation protrusion
280: Spring Cover
290 guide cover
300: main spring
400: housing

Claims (4)

In the lifting module of the stud welding gun is installed in the rear of the gun body to move the gun body forward or backward,
A front end fixedly coupled to the rear end of the gun body, and a rear end extending rearward;
The gun body is slidably installed as far as the forward and backward distances, and a rubber tube is provided to surround the outer peripheral surface of the rear end of the lifting bar. An air gripping part for pressing and holding the outer circumferential surface;
A solenoid fixedly installed at the rear of the air gripping part and having a coil wound around the bobbin to generate a magnetic field by receiving power;
A front end is fixedly coupled to the rear end of the air gripping portion, the magnetic material provided in the rear end is inserted into the bobbin of the solenoid and the slider to move backward in accordance with the power supply of the solenoid,
Lifting module of the stud welding gun comprising a lifting spring for providing a spring force from the rear of the slider to the front.
The method of claim 1,
The rubber gripping portion of the air gripping portion is provided with a flange protruding in the circumferential direction at the front and rear ends,
The air holding unit,
A cylindrical air cylinder having a stepped surface formed in each of the front and rear surfaces so that flanges protruding from the front and rear ends of the rubber tube are respectively inserted, and the rubber pipe is inserted therein and an air inlet hole penetrates from the outer circumferential surface to the inner circumferential surface;
And a front air cover and a rear air cover respectively coupled to the front and rear surfaces of the air cylinder so as to press the flanges protruding from the front and rear ends of the rubber tube, respectively.
The method of claim 2,
A ring-shaped rotation prevention ring interposed between the air gripping portion and the solenoid and fixedly coupled to the solenoid, and having an insertion hole formed on a surface facing the air gripping portion;
Lifting module of the stud welding gun, characterized in that it further comprises an anti-rotation projection protruding to slide into the insertion hole of the anti-rotation ring on the surface facing the anti-rotation ring of the rear air cover.
The method of claim 1,
A spring cover interposed between the slider and the lifting spring to provide a spring force of the lifting spring to the slider;
Lifting module of the stud welding gun, characterized in that it further comprises a guide cover fixed to the rear of the solenoid to guide the front and rear sliding of the spring cover.

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