KR102205840B1 - Resistance Welding Machine for Stud Welding - Google Patents

Abstract

The present invention relates to a resistance welding device for stud welding, and more specifically, to a resistance welding device for stud welding, to which a stud is consistently and reliably supplied between electrodes, thereby performing high-quality stud welding. The resistance welding device for stud welding according to the present invention comprises: an upper electrode disposed to face a lower side to be in contact with a plate material; an elevation member connected to the upper electrode to elevate the upper electrode to press the upper electrode against the plate; a fixing member formed to enable the stud supplied from the outside to be seated, having a stud seating portion disposed on a lower side of the upper electrode, and made of a conductive metal material; a support member connected to the fixing member and configured to rotationally support the fixing member with respect to a horizontal rotation axis such that the fixing member rotates, and the stud seating portion receives the stud and enables the stud to face the upper electrode at the top; a rotating member connected to the fixing member and configured to rotate the fixing member with respect to the support member; and a lower power member electrically connected to the fixing member and configured to form a potential difference between the upper electrode and the fixing member.

Description

Resistance Welding Machine for Stud Welding}

The present invention relates to a resistance welding machine for stud welding, and more particularly, to a resistance welding machine for stud welding of a rotary electrode structure capable of using studs according to standards.

Welding is a technology that joins metal, glass, plastic, etc. with heat and pressure. This is by forming an interatomic bond between two materials and bonding, thereby saving materials.

Resistance welding in one field of the classification of welding refers to welding in a method of welding a solvent using resistance heat. Resistance welding is a comparative example, and unlike the arc welding method, soot does not occur in the base material, and defects such as pore formation due to welding sparks can be prevented. Resistance welding is a method widely used in automotive, ship, and aircraft industries that require high quality. For example, in the automobile industry, it is a mounting unit for mounting various components such as engines, transmissions, steering systems, etc. to a base such as a body panel and a frame, and for bolting and coupling the base materials such as metal panels and the above parts. Bolt-type studs (eg round bars, bolts or nuts) are used.

The stud is welded to the base material by welding. This stud welding method is the latest welding method of electronic control technology that uses the basic principles of arc welding and resistance welding.It is a welding method that instantly welds the stud to the base material without making a hole in the base material. It is the most ideal and economical fastening method that satisfies the fastening conditions.

Resistance welding machines that perform such resistance welding include a stationary type installed based on the ground, and a modular type mounted with an end effector or a welding gun of a robot.

The stationary type is large in weight and volume, and may not have miniaturization and weight reduction technology applicable to robots and the like.

In contrast, the modular type of resistance welding machine for robot mounting should be able to maintain welding quality even during precise control operation through a lightweight and compact configuration that can satisfy the payload of the robot. In particular, welding failure due to thermal load, In order to minimize the deformation of the welding machine component parts, quality improvement and cost reduction through light weight and miniaturization technology that can realize reliability and accuracy and improved welding appearance quality are very important.

However, the conventional resistance welding machine occupies a relatively large volume, requires a relatively large operating radius due to the multi-joint rotational structure, and resistance welding by reliably loading and placing the supplied stud at the welding position and feeding it safely. It is somewhat insufficient to realize.

In addition, since the resistance welding machine of the prior art performs resistance welding by receiving only one type of stud, it is difficult to be used for stud welding of automobile plates having connection members of different sizes.

In addition, in the relevant industrial field that used the conventional resistance welding machine, while realizing high quality and minimum cost, thermal deformation generated in the electrode and its surrounding members due to the high heat generated during resistance welding, or the electrodes are in close contact with each other for resistance welding. There is an urgent need for a technology capable of very efficiently solving these problems and risks in consideration of the problem of electrode shake due to repeated loads during the operation and the risk of short circuit when repeatedly performing power supply and disconnection.

The present invention was conceived to solve the above-described necessity, and an object of the present invention is to provide a resistance welder for stud welding capable of performing high quality stud welding by continuously and reliably supplying studs between electrodes. .

In the present invention for achieving the above object, the resistance welder for stud welding includes: an upper electrode disposed downward so as to contact the plate material in order to continuously receive a bolt-shaped stud and weld it to a plate material; An elevating member connected to the upper electrode so as to pressurize the upper electrode against the plate material to lift the upper electrode; A fixing member formed to seat the studs supplied from the outside, and having a stud seating portion disposed under the upper electrode and formed of a conductive metal material; A support member that is connected to the fixing member so that the fixing member rotates so that the stud seating part faces the upper electrode on the upper side by receiving the stud from a lateral direction to rotatably support the fixing member about a horizontal axis of rotation ; A rotation member connected to the fixing member to rotate the fixing member with respect to the support member; And a lower power member electrically connected to the fixing member so as to form a potential difference between the upper electrode and the fixing member.

The resistance welding machine for stud welding according to the present invention, after stably placing the stud in the stud seating portion, rotates the stud seating portion and the stud toward the welding position of the upper electrode, so that resistance welding can be performed smoothly.

1 is a perspective view of a resistance welding machine for stud welding according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along line AA of the resistance welding machine for stud welding shown in FIG. 1.
3 is an enlarged cross-sectional view of the fixing member and the support member shown in FIG. 2.
4 is a cross-sectional view for explaining the operation of the stud seat shown in FIG. 3.
5 and 6 are cross-sectional views for explaining the operation of the lower electrode member of the box B shown in FIG. 2.
7 is a view for explaining a welding method of the resistance welding machine for stud welding shown in FIG.

Hereinafter, a resistance welder for stud welding according to an embodiment of the present invention will be described with reference to FIGS. 1 to 7.

The present invention is characterized in that resistance welding can be performed by rotating a fixing member having a plurality of stud seats capable of mounting studs of different standards in a resistance welding machine for stud welding. In addition, the present invention is characterized in that it can be applied as a hybrid device that can be applied to both a stationary welding facility or an arm of a robot by having a mounting bracket and a housing. Through this, the resistance welding machine for stud welding according to the present embodiment can prevent heat deformation that may occur during welding in advance, remove foreign substances and maximize electrical and physical operation safety.

1 is a perspective view of a resistance welding machine for stud welding according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line A-A of the resistance welding machine for stud welding shown in FIG. 1.

First, with reference to FIGS. 1 and 2, the resistance welder for stud welding according to the present embodiment is mounted on an arm of a robot, and in this case, it may be understood as an end effector or a welding gun. For example, a robot (not shown) applicable to the resistance welding machine for stud welding of the present embodiment may have a controller capable of controlling 6 degrees of freedom or degrees of freedom to perform resistance welding on a welding object.

At this time, the controller may be configured to follow the position and orientation of the corresponding degree of freedom, and as a result, control the position and attitude of the resistance welder for stud welding mounted on the arm of the robot, or It may be configured to perform relatively simple and safe operation of the welding machine to be described later, that is, the vertical lifting operation of the lifting member 200 and the rotation angle control of the fixing member 300 by the rotation member 500. For example, the controller controls the forward and backward member 620 of the lower power member 600 to control the lower electrode member whenever the plurality of stud seating portions 310 to be described later sequentially come to a position facing the upper electrode 100. When 610 is advanced, the elevating member 200 may also be configured to control an operation of lowering the upper electrode 100. In addition, the controller may be configured to control an operation of moving the lower electrode member 610 backward and raising the upper electrode 100 through the lifting member 200 after resistance welding.

And, the robot applicable to this embodiment may have a degree of freedom of less than 6 degrees of freedom as needed, such as a horizontal articulated robot or a polar type robot, and may be a robot capable of implementing 6 degrees of freedom in some cases. It may not be limited to robots with degrees of freedom.

The resistance welder for stud welding according to the present embodiment that can be mounted and used in such a robot may be continuously supplied with a bolt-shaped stud 10 and welded to a base material or a plate material.

To this end, the resistance welding machine for stud welding of the present embodiment includes an upper electrode 100, an elevating member 200, a fixing member 300, a support member 400, a rotating member 500, and a lower portion as will be described in detail below. It may be configured to include the power member 600, and may have a housing 700 and a mounting bracket 800, which are a base for mounting these components.

The housing 700 and the mounting bracket 800 are made of a material for a lightweight casing structure, such as an aluminum alloy, and may be configured to be disassembled and assembled by fastening a plurality of bolts.

The housing 700 and the mounting bracket 800 may be electrically grounded to internal or external components.

At least one or one or more fluid distribution blocks 710 including a plurality of valves and piping members may be provided in the housing 700 for pneumatic distribution or cooling water supply. The fluid distribution block 710 may be connected to an air pump, a cooling water supply and recovery device (eg, a cooling water pump and a radiator), which is not shown. The fluid distribution block 710 may further include a conventional pneumatic or hydraulic circuit component (not shown), and an operating source to the elevating member 200 or the forward/reverse member 620 to be described later through such a pneumatic or hydraulic circuit component. It can play a role of supplying or recovering (eg pneumatic), supplying and recovering cooling water, and supplying high-pressure air for removing foreign substances.

The mounting bracket 800 may be physically and electrically connected to an arm of a robot (not shown), or may have a flange connection structure or a quick joint structure so that it may be mounted on a stationary welding facility.

The mounting bracket 800 may be attached to the rear surface of the housing 700.

The upper electrode 100, the lifting member 200, the fixing member 300, and the support member 400 may be disposed or installed based on the front surface of the housing 700.

Due to this arrangement based on the housing 700, the resistance welder for stud welding of the present embodiment can be a lightweight and small hybrid device or equipment that can be applied to both stationary equipment or robot arm. Has an advantage.

In addition, the housing 700 may be a mounting base for the servo motor 510, or may be separately mounted and a modular stud feeder (not shown) capable of individually supplying the studs 10 to the stud seat 310 And a mounting base of a laser sensor (not shown) capable of detecting the stud mounting state.

A power supply device 900 including a transformer, a welding driver, a power supply material, and electric wires 910 and 911 for performing resistance welding may be installed inside the housing 700.

Here, the electric wire 910 on one side of the power supply device 900 may form a negative electrode (eg, a negative electrode) in the lower electrode member 610. For example, one end of one end of the wire 910 is electrically connected to the power port of the power supply device 900, and the other end of the one end of the wire 910 is electrically connected to the electrode moving plate 630 of a conductive material. I can. The lower electrode member 610 may be mounted on the electrode moving plate 630 so as to protrude along the moving (for example, forward or backward) direction of the electrode moving plate 630. In addition, the lower electrode member 610 and the electrode moving plate 630 may be mounted on the moving frame 621 of the forward and backward member 620 to be moved forward or backward (P).

In addition, the forward and backward member 620 may be a guide pneumatic cylinder or an actuator. In this case, an insulating pad 640 may be interposed between the moving frame 621 of the forward and backward member 620 and the electrode moving plate 630. The insulating pad 640 prevents a current from shorting toward the forward and backward member 620, prevents malfunction of the forward and backward member 620, prevents a short circuit accident, and enables efficient use of welding current. There is an advantage to be able to.

On the other hand, the other side wire 911 of the power supply device 900 is electrically connected to the upper electrode 100 through a conventional resistance welding gun or a welding machine feeder, so that the upper electrode 100 is an anode (eg, + electrode). ) May be configured.

The upper electrode 100 may be disposed to face downward so as to contact a base material or a plate material to be welded.

Here, under the upper electrode 100, the stud seating portion 310 may be disposed opposite to each other (eg, arranged to face upward) with a gap corresponding to the base material or the plate material and the free space. That is, the plate may be supplied between the upper electrode 100 and the stud seat 310 for resistance welding.

The elevating member 200 may include a holder frame 201 protruding from an upper front portion of the housing 700 and an elevating cylinder 210 installed based on the holder frame 201.

The lifting cylinder 210 raises or lowers (M) the rod 211 using pneumatic pressure to generate a pressing force required for resistance welding, or quickly the rod 211 by using the tension of the spring damper 202 attached thereto. There is an advantage of being able to put the original position.

The lifting member 200 using the lifting cylinder 210 may be connected to the upper electrode 100 to pressurize the upper electrode 100 against the plate material and may serve to lift the upper electrode 100.

Here, the upper electrode 100 may be detachably connected or coupled to the rod 211 of the lifting cylinder 210 of the lifting member 200 for maintenance and replacement.

The upper electrode 100 is a tungsten-coated electrode and has an advantage of relatively increasing an electrode lifetime.

The fixing member 300 may be formed of a conductive metal material. For example, the fixing member 300 includes a plurality of stud seating portions 310, a seating block 319 in which the stud seating portions 310 are disposed at predetermined angular intervals, and rotation of the seating block 319 It may mean an assembly of a rotating shaft 330 axially coupled to the seating block 319 with respect to the central axis RL and a hole bushing 320 axially coupled to an end of the rotating shaft 330. That is, the fixing member 300 as such an assembly may be formed of a conductive metal material.

Accordingly, the current of the power supply device 900 passes through one side of the electric wire 910, the electrode moving plate 630, the lower electrode member 610, the hole bushing 320, the rotating shaft 330, and the seating block 319. Thus, the cathode may be formed by flowing to the stud seating portion 310.

In this case, the stud seat 310 may be disposed under the upper electrode 100.

The stud seating portions 310 of the fixing member 300 are provided in plural (for example, 3 to 4), and the plurality of stud seating portions 310 are along the circumferential direction with respect to the rotational central axis RL. They may be arranged at equal angular intervals.

For example, when the number of stud seating portions 310 is made of four as shown in FIG. 1, the four stud seating portions 310 are centered on the rotation axis of the fixing member 300, that is, the rotation center axis RL It may be arranged at 90 degree intervals based on. In addition, although not shown in FIG. 1, in the case of three stud seating portions 310, the three stud seating portions 310 may be arranged at intervals of 120 degrees with respect to the rotational central axis RL of the fixing member 300. That is, according to the design change of the seating block 319 of the fixing member 300, the mounting or connection position and number for the stud seating portion 310 can be changed, so the number and angular intervals of the stud seating portion 310 are specific May not be limited to numerical values.

In addition, each stud seating portion 310 is formed to seat the studs 10 supplied from the outside, as will be described later.

For example, a modular stud feeder not shown may supply the stud 10 to the stud seat 310 in the X-axis direction. Thereafter, due to the rotation R of the fixing member 300 by the rotation member 500, the stud 10 of the stud seating portion 310 may be disposed at a welding position below the upper electrode 100.

To this end, the support member 400 rotates the fixing member 300 so that the stud seat 310 is supplied with the stud 10 in the lateral direction (eg, in the X-axis direction) and faces the upper electrode 100 on the upper side. It is connected to the fixing member 300 so that it can be rotated (eg, in the Z-axis direction) to support the fixing member 300 in a horizontal direction (eg, the Y-axis or the rotation center axis (RL)). can do.

For example, the support member 400 may be coupled to protrude from the lower front of the housing 700 using a plurality of bolts and flanges.

The rotation member 500 may be connected to the fixing member 300 and may serve to rotate (R) the fixing member 300 with respect to the support member 400.

To this end, the rotation member 500 may include a servo motor 510 disposed or installed parallel to the rotation center axis RL at the bottom of the housing 700. In addition, the rotating member 500 may include a power transmission system 520 coupled to the motor shaft of the servo motor 510. Here, the power transmission system 520 may be composed of a drive pulley fastened to the motor shaft, a driven pulley fastened to the rotating shaft 330, and a belt (eg, a timing belt) coupled to these pulleys.

The motor driver of the servo motor 510 may be connected to the controller through a cable not shown.

In addition, the rotational force of the limited angle generated by the operation of the servo motor 510 may serve to maintain a stopped state after rotating the fixing member 300 at 90 degree intervals or predetermined angular intervals.

To this end, the servo motor 510 may further include a connection terminal unit connectable to a gear box, a servo motor driver, and a controller, not shown.

The lower power member 600 may be electrically connected to the fixing member 300 so as to form a potential difference between the upper electrode 100 and the fixing member 300.

Here, the meaning of being electrically connected to the fixing member 300 may mean that the lower electrode member 610 may be selectively performed according to a switching operation according to the forward or backward movement of the lower electrode member 610.

To this end, the lower power member 600 may include the lower electrode member 610 and the forward and backward member 620 mentioned above.

The lower electrode member 610 may be connected to the power supply device 900 to form a potential difference with the upper electrode 100 and may be disposed at a position adjacent to the fixing member 300.

In more detail, the lower electrode member 610 is electrically connected or connected to the power supply device 900 through the electrode moving plate 630 and one side wire 910, and the switching hole 321 of the hole bushing 320 It may be adjacent to the fixing member 300 through the inside of.

In addition, the aforementioned guide pneumatic cylinder or actuator forward and backward member 620 advances the lower electrode member 610 from the inside of the switching hole 321 of the hole bushing 320 with respect to the fixing member 300 to move the hole bushing. (320), the rotation shaft 330 and the seating block 319 may play a role of contacting the fixing member 300 electrically and physically.

In addition, the forward/reverse member 620 may play a role of separating the lower electrode member 610 from the fixing member 300 by moving the lower electrode member 610 backward with respect to the fixing member 300.

Hereinafter, the detailed configuration and operation of the lower electrode member 610, the shape features of the fixing member 300 and the support member 400, and the internal configuration of the stud seat 310 will be described in detail.

3 is an enlarged cross-sectional view of the fixing member and the support member shown in FIG. 2, FIG. 4 is a cross-sectional view for explaining the operation of the stud seating unit shown in FIG. 3, and FIGS. 5 and 6 are box B shown in FIG. 2 Is a cross-sectional view for explaining the operation of the lower electrode member.

First, referring to FIGS. 2 and 5 and 6, the fixing member 300 includes a switching hole 321 formed in the hole bushing 320 along the rotation center axis RL on the rotation center axis RL. , It may include an inner diameter insulating portion 322 for insulating the inner diameter of the switching hole 321.

When a part of the lower electrode member 610 of the lower power member 600 described above (for example, a switching contact head) is inserted into the switching hole 321 of the hole bushing 320 of the fixing member 300, the switching hole ( It may be disposed in the inner space of the inner diameter insulating portion 322 provided in the inner diameter of 321.

Because of this arrangement, as shown in FIG. 5, in a state reversed by the forward/reverse member 620, the end of the switching hole 321 and the end of the lower electrode member 610 are non-contact with each other, and the lower part excluding the end A part of the electrode member 610 (eg, the circumferential surface) contacts only the inner circumferential surface of the inner diameter insulating portion 322, as a result, the lower electrode member 610 is insulated from the fixing member 300 by the inner diameter insulating portion 322 Can be.

In such a reverse state, the current of the power supply device 900 is transmitted only to the lower electrode member 610 and may not be transmitted to the fixing member 300 and the stud seat 310 thereof.

On the other hand, as shown in FIG. 6, in a state advanced by the forward and backward member 620, the end of the lower electrode member 610 may contact the end of the switching hole 321 to conduct electricity.

In this advanced state, the current of the power supply device 900 passes through the lower electrode member 610, the switching hole 321 of the hole bushing 320, and the rotation shaft 330, and the fixing member 300 and its stud seating portion ( 310) can be delivered.

In addition, since the end of the lower electrode member 610 transmits the forward force of the forward and backward member 620 to the end of the switching hole 321, as a result, the hole bushing 320 having the switching hole 321 and rotation It may also serve as a pressurized brake capable of maintaining the entire fixing member 300 including the shaft 330 in a fixed state. In addition, since the fixing member 300 can stably maintain the stationary state through this, the smoothness during resistance welding can be maintained very advantageously.

Referring to FIG. 3, the fixing member 300 includes two rows of cooling grooves 350 and 351 formed in the rotation shaft 330, and a fixed cooling passage 370 formed in the rotation shaft 330 and the seating block 319. Can include.

Here, the two rows of cooling grooves 350 and 351 may be formed in a ring shape on the cylindrical contact surface 340 of the rotating shaft 330 which contacts and rotates relative to the support member 400.

The two rows of cooling grooves 350 and 351 may be spaced apart from each other along the longitudinal direction of the rotation shaft 330.

Passage holes 352 and 353 for connecting to the fixed cooling channel 370 may be formed in the two rows of cooling grooves 350 and 351.

The fixed cooling passage 370 can cool the stud seat 310, the seat block 319, the rotation shaft 330, and the support member 400 in consideration of the thermal load during resistance welding or maintain a predetermined temperature. Thus, it may be formed in the same or similar to the cooling water circulation loop. For example, the fixed cooling passage 370 may be formed to be connected to the two rows of cooling grooves 350 and 351 via a position 360 adjacent to the stud seat 310.

In this case, the support member 400 may include a cooling inlet 440 and a cooling outlet 441 respectively formed to be connected to two rows of cooling grooves 350 and 351 of the fixing member 300.

The cooling inlet 440 and the cooling outlet 441 may be connected to an external cooling water supply/recovery device through a pipe and a fluid distribution block 710 not shown.

In addition, the fixing member 300 has a pneumatic groove 380 formed on the cylindrical contact surface 340 of the rotating shaft 330 that rotates relative to the support member 400, the pneumatic groove 380 and the stud seating portion It may include a fixed pneumatic flow path 390 formed to connect the 310.

Here, the pneumatic groove 380 may be formed on the cylindrical contact surface 340 of the rotating shaft 330 based on the position between the two rows of cooling grooves 350 and 351, and may be formed by cold and constant pressure air. There is also an additional advantage of relatively reducing the thermal load of the cooling water of the rotating shaft 330 or the fixed cooling passage 370.

The high-pressure air supplied to the stud seating portion 310 through the pneumatic groove 380 and the fixed pneumatic flow path 390 and discharged to the outside has the advantage of removing or discharging foreign substances that may occur inside the stud seating portion 310. Can be demonstrated.

In addition, the pressure of the air may be changed to a positive pressure or negative pressure state, and through this, it may help seating or separating the stud 10 mounted on the stud seating part 310, so that the stud 10 during resistance welding It can exhibit the advantage of stably supplying or separating.

In addition, in order to supply high-pressure air, the support member 400 may include a support pneumatic flow path 470 formed to be connected to the pneumatic groove 380 according to the displacement of the fixing member 300.

In addition, among the circumferential contact surfaces 340 of the rotating shaft 330, a sealing groove is formed along the circumferential direction around each of the cooling grooves 350 and 351 and the pneumatic groove 380, and an O-ring ( 332) may be installed respectively.

In addition, the O-ring 332 may be formed of an insulating material that is the same as or similar to the insulating pad 640 mentioned above.

This O-ring 332 may be a component that can be used as a sealing means or airtight means as well as a function of an insulator, and a U-cup seal having a groove in a ring shape, a circular cross section, an elliptical cross section, a square cross section It may have various cross-sectional shapes, such as, and the O-ring seal or cross-sectional shape may not be limited to a specific shape as long as smooth rotation, insulation, and airtightness or watertightness can be maintained.

Thus, through each of the O-rings 332, the coolant or high-pressure air may exhibit the advantage that it may not leak through the gap (eg, rotational clearance) between the support member 400 and the rotation shaft 330.

In addition, an insulating washer and thrust bearing assembly 334 may be interposed at a portion of the stepped portion of the rotating shaft 330 that faces the support member 400.

In addition, a bearing recess portion 336 may be formed in the support member 400 so that the rotation shaft 330 can be rotatably supported with respect to the support member 400.

At this time, the bearing recess portion 336 is provided with an insulating main bearing 338 that can be understood through FIGS. 2 and 3, and a rotating shaft 330 may be axially coupled to the inner diameter of the insulating main bearing 338. .

Therefore, by the O-ring 332, the insulating washer and thrust bearing assembly 334 and the insulating main bearing 338, the current of the negative electrode of the rotating shaft 330 is directed toward the fixing member 300 and its stud seat 310. Only electricity can be energized, and by preventing leakage of the welding power source, it is possible to prevent malfunction due to current leakage, prevent leakage accidents, and efficiently use welding current.

In addition, the insulating washer and thrust bearing assembly 334 and the insulating main bearing 338 are disposed to form a right angle to each other, so that the bending deformation of the rotating shaft 330 can be minimized.

Accordingly, due to the occurrence of sagging of the rotating shaft 330, a welding failure caused by an irregular oblique contact with the plate material to be welded can be prevented in advance of the head portion of the stud 10. For example, welding defects that may occur due to oblique contact may include deformation of the stud 10, poor welding fusion, and decrease in strength.

In addition, even if the support member 400 and the fixing member 300 are rotating relative to each other, the cooling water may be prevented by the fixed cooling flow path 370, the cooling grooves 350 and 351, the cooling inlet 440, and the cooling outlet 441. Supply and recovery can be realized reliably and continuously.

In this case, the stud seating portion 310 can be free from increased wear due to high-temperature thermal load, and the resistance change can be minimized by maintaining an appropriate temperature to smoothly provide the current required for resistance welding, and the occurrence of burnout can be prevented. It has the advantage of being able to reduce and homogenize the welding quality.

In addition, high-pressure air can be reliably and periodically supplied to the stud seat 310 by the fixed pneumatic flow path 390, the pneumatic groove 380, and the supporting pneumatic flow path 470 in the same manner.

Thus, since the resistance welder for stud welding of this embodiment has a water-cooled cooling method, even if the fixing member 300 rotates in a state in which a plurality of stud seating portions 310 are mounted, each stud seating portion 310 is It can be intensively and quickly cooled by the cooling water passing through the position 360 adjacent to the stud seat 310, and with this, by securing the original insulation from the cooling water or high-pressure air, safety accidents such as electric shock and electric leakage are prevented. It may have features that can be prevented in advance.

Meanwhile, referring to FIG. 4, each stud seating portion 310 is formed of the same tungsten-coated electrode material as the upper electrode 100, and includes a cap portion 312 having a seating hole 311 through which the stud 10 can be inserted. Can have

Further, the stud seating portion 310 may include a base portion 313 that is screwed to the cap portion 312 and connected to four points of the seating block 319 of the fixing member 300, respectively.

In particular, since the cap portion 312 is a tungsten-coated electrode material and can be replaced by screwing the base portion 313, it may have the advantage of facilitating maintenance.

In addition, the size of the seating hole 311 of the cap portion 312 may correspond to various sizes or may be variously determined according to the bolt standard (eg, M6, M8, M10, M12, etc.), so the stud seating portion 310 It is possible to provide an advantage of applying or accommodating the studs 10 of various standards.

In addition, the internal space of the base portion 313 has a plurality of free end-shaped elastic pieces so that the screw portion opposite the head portion of the stud 10 can be temporarily bited by elasticity or separated by an external force action. Fixtures 314 may be installed.

For example, the end portions of the plurality of elastic pieces of the fastener 314 may have inclined surfaces each inclined downward toward the center of the fastener 314, respectively.

In addition, an inclined surface in the same direction may be formed on the edge of the end of the screw portion of the stud 10.

In this case, the inlet diameter of the fixture 314 is relatively small, but may be small compared to the outer diameter of the screw of the bolt portion of the stud 10.

Therefore, when the stud 10 enters the stud seating portion 310 from the outside, the inclined surface of the end rim of the screw portion of the stud 10 and the inclined surface of the end of the elastic piece of the fastener 314 slide as an oblique treatment relationship with each other. Can be contacted.

As a result, as the inlet diameter of the fixture 314 is expanded, each elastic piece of the fixture 314 causes elastic deformation to the outside and is temporarily opened and then fixed (Q) to the screw portion of the stud 10. The elastic friction force may be applied, and the outer surface of the screw portion of the stud 10 may be bitten by the inner surface of the elastic piece of the fastener 314.

In this state, even if the fixing member 300 and the stud seating portion 310 rotate based on the aforementioned rotational center axis RL, the stud 10 remains stably placed in the stud seating portion 310 Or it may not be separated from the stud seat 310, it is possible to maintain a stable welding standby state.

The fixed pneumatic flow paths 390 may be connected to each other in space through the bottom of the inner space of the base part 313.

In addition, a through hole 317 and a cutout 318 may be formed in the elastic piece of the fastener 314, respectively. Here, the elastic piece of the fastener 314 may serve as a fixing means for the stud 10 and a cooling pipe. For example, high-pressure air supplied to the inside of the stud seat 310 serves to cool the temperature of the elastic piece of the fixture 314 and to discharge foreign matter inside the stud seat 310 to the outside. I can.

In addition, the fixture 314 may be placed on the hollow sheet portion 315 provided at the bottom position of the inner space of the base portion 313.

The high-pressure air can be freely introduced into the inner space of the base part 313 or the inner space of the fixture 314 from the fixed pneumatic flow path 390 through the center hole of the hollow seat part 315, and the seating hole 311 ) Can be discharged or discharged.

Through this, foreign substances that may be introduced into the stud seating portion 310 may be removed or cleaned by the discharged high-pressure air.

In this way, the stud seating portion 310, in which foreign matter can be removed by high-pressure air, can prevent current flow interference due to foreign matter in advance, and has an advantage of preventing sporadic phenomena. Here, the sporadic phenomenon may refer to a phenomenon in which the molten metal is ejected between the plate and the stud or on the inner molten region (eg, a nugget) generated during fusion due to an excessive current density.

Even if the stud 10 is placed in the stud seat 310 due to a malfunction, when air is introduced into the stud seat 310 with a pressure greater than the aforementioned elastic friction force and the load of the stud 10 , The advantage of being able to quickly and easily remove the stud 10 from the stud seat 310 may be exhibited.

In addition, the hollow sheet part 315, the fixture 314, the cap part 312, and the base part 313 have relatively low electrical resistance (eg, resistivity) compared to the base material or plate material or stud 10 to be welded. , It may be an electrode material for resistance welding having high thermal conductivity.

For example, the inner or outer material of the upper electrode 100 and the stud seat 310 applicable in this embodiment is a tungsten-coated alloy material, a non-fusion alloy material (eg, a chromium-added copper alloy, zirconium, titanium alloy), a special material ( Example: Dispersion reinforced copper alloy, nickel beryllium), etc.) may be made of one or more materials selected from the group, and may not be limited to a specific material.

In addition, when the end of the switching hole 321 described above and the end of the lower electrode member 610 contact each other, the cathode current of the power supply device 900 is hollow through the mounting block 319 of the fixing member 300 It may be transmitted to the stud seating portion 310 including the type sheet portion 315, the fixture 314, the cap portion 312 and the base portion 313.

That is, the power supply device 900 may form an anode in the upper electrode 100 and may form a cathode in the stud seat 310.

And, when the upper electrode 100 contacts and presses the plate material toward the stud 10, the screw portion of the stud 10 is a plate material in a state that can be cooled by the hollow seat portion 315 and the fixture 314 Resistance welding can be performed very efficiently at the head of the stud 10.

Hereinafter, a method of operating the resistance welding machine for stud welding according to the present embodiment will be described.

7 is a view for explaining a welding method of the resistance welding machine for stud welding shown in FIG.

Referring to FIG. 7, the stud 10 may be supplied to the stud seat 310 along the X-axis direction of FIG. 1 or 7 by a modular stud feeder (not shown).

In this case, the stud 10 may be mounted on the stud mounting portion 310 as described with reference to FIG. 4. In this case, the fastener 314 having an elastic piece may temporarily fix the screw portion of the stud 10 inserted into the stud seat 310.

Thereafter, the controller controls the driving of the servo motor 510 of the rotating member 500 and, as a result, rotates the fixing member 300 by 90 degrees.

In this case, as shown in (a) of FIG. 7, the stud seating portion 310 and the stud 10 of the fixed member 300 in a rotated state are placed in a position facing the upper electrode 100 and in the Z-axis direction. .

Further, the base material W is disposed between the upper electrode 100 and the stud 10.

Whenever the plurality of stud seating portions 310 sequentially come to a position facing the upper electrode 100 in accordance with the control signal of the aforementioned controller, the forward/reverse member 620 of the lower power member 600 described above is The lower electrode member 610 is moved forward. In this case, as described with reference to FIG. 6, the current of the cathode of the lower electrode member 610 is transmitted to the stud seating portion 310 via the hole bushing 320, the rotating shaft 330, and the seating block 319. Can be.

In addition, the controller controls the lifting member 200 to lower the upper electrode 100 of the anode, presses the base material W, and controls the arm and the welding machine position of the robot together with the resistance welding machine for stud welding itself. By controlling the upward movement to the upward by a predetermined height, the state as shown in (b) of FIG. 7 can be obtained.

In this case, the current supplied for resistance welding flows from the upper electrode 100 of the positive electrode to the stud seat 310 of the negative electrode via the base material W and the stud 10.

In addition, heat is generated by the potential difference formed at the contact portion between the base material (W) and the stud 10 between the upper electrode 100 and the stud seating portion 310 of the fixing member 300 or the current supplied to the contact resistance portion. So that resistance welding can be made.

Thereafter, according to a control signal for each condition (eg, time, current change) set in the controller, the forward/reverse member 620 of the lower power member 600 moves the lower electrode member 610 backward (see FIG. 5 ). In this case, the current of the cathode of the lower electrode member 610 is insulated from the fixing member 300 by the inner diameter insulating portion 322, so that the current may be cut off so that it no longer flows through the base material (W) and the stud (10). have.

Thereafter, the controller controls the position of the arm and the welding machine of the robot along with the operation of raising the upper electrode 100 by the elevating member 200, as shown in (c) of FIG. 7 to lower the resistance welding machine for stud welding itself. You can control the movement.

By this relative movement control, the screw portion of the stud 10 welded to the base material W may be separated from the stud seat 310.

As such, the resistance welding machine for stud welding according to the present embodiment may be compatible with both robot or stationary type, and the fixing member 300 capable of being rotated and stopped by the rotating member 500 is integrated into the housing 700. By providing, the structure is simple, the driving precision can be secured without a separate link or multi-joint attachment device, and it has the advantage of being very suitable for a pressurized environment.

In particular, the resistance welding machine for stud welding according to the present embodiment is an end effector or welding gun having a simple structure and a compact structure, and has a very advantageous advantage in simplifying a robot configuration and avoiding an interference section during robot control.

100: upper electrode 200: lifting member
300: fixing member 310: stud seating portion
319: seating block 320: hole bushing
330: rotating shaft 340: cylindrical contact surface
350, 351: cooling groove 370: fixed cooling passage
380: pneumatic groove 390: fixed pneumatic flow path
400: supporting member 500: rotating member
600: lower power member 610: lower electrode member
620: forward and backward member 700: housing
800: mounting bracket 900: power supply

Claims (8)

In a resistance welding machine for stud welding for welding to a plate by continuously receiving a bolt-shaped stud,
An upper electrode disposed downward so as to contact the plate material;
An elevating member connected to the upper electrode so as to pressurize the upper electrode against the plate material to lift the upper electrode;
A fixing member formed to seat the studs supplied from the outside, and having a stud seating portion disposed under the upper electrode and formed of a conductive metal material;
A support member that is connected to the fixing member so that the fixing member rotates so that the stud seating part faces the upper electrode on the upper side by receiving the stud from a lateral direction to rotatably support the fixing member about a horizontal axis of rotation ;
A rotation member connected to the fixing member to rotate the fixing member with respect to the support member; And
Includes; a lower power member electrically connected to the fixing member so as to form a potential difference between the upper electrode and the fixing member,
The lower power member includes a lower electrode member connected to a power supply device and disposed at a position adjacent to the fixing member so as to form a potential difference with the upper electrode, and the lower electrode member advancing with respect to the fixing member. A resistance welder for stud welding comprising a forward and backward member for contacting a fixing member and moving the lower electrode member backward with respect to the fixing member to separate from the fixing member. delete The method of claim 1,
The fixing member further includes a switching hole formed on the rotation center axis along the rotation center axis, and an inner diameter insulating portion insulating an inner diameter of the switching hole,
A portion of the lower electrode member of the lower power member is inserted into the switching hole of the fixing member and is insulated from the fixing member by the inner diameter insulator and advanced by the forward/reverse member in a state in which it is moved backward by the forward and backward member. In the state, an end portion of the lower electrode member contacts an end portion of the switching hole to conduct electricity. The method of claim 1 or 3,
A resistance welder for stud welding wherein a plurality of stud seating portions of the fixing member are provided, and the plurality of stud seating portions are arranged at equal angular intervals along a circumferential direction. The method of claim 4,
The number of the plurality of stud seating portions of the fixing member is 4,
The resistance welding machine for stud welding that the four stud seating portions are arranged at intervals of 90 degrees about the rotation axis of the fixing member. The method of claim 4,
The forward and backward member of the lower power member advances the lower electrode member whenever the plurality of stud seating portions sequentially come to a position facing the upper electrode, and at this time, the elevating member is also used for stud welding to lower the upper electrode. Resistance welding machine. The method of claim 1 or 3,
The fixing member is formed so as to be connected to the cooling grooves of the second row via a position adjacent to the two rows of cooling grooves formed in a ring shape on the cylindrical contact surface that rotates relative to the support member and the stud seating portion It further includes a cooling channel,
The support member further comprises a cooling inlet and a cooling outlet formed to be respectively connected to two rows of cooling grooves of the fixing member. The method of claim 7,
The fixing member further includes a pneumatic groove formed on a cylindrical contact surface that is in contact with the support member and rotates relative to each other, and a fixed pneumatic flow path formed to connect the pneumatic groove and the stud seat,
The support member further comprises a support pneumatic flow path formed to be connected to the pneumatic groove according to the displacement of the fixing member.

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