JP2003154465A - Resistance welding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resistance welding machine which is capable of performing welding even inside a metal member formed of steel plates, or a structure of a metal box or a metal frame assembled by metal members, and performing the downward welding with the pressure applied upwardly, and structurally compact. SOLUTION: The resistance welding machine 100 to perform the resistance welding by connecting one pole of a welding power source to a plate-like electrode formed of a flat plate, connecting a welding tip to the other pole of the welding power source, and holding a work between the welding tip and the plate-like electrode to perform the electric pressure comprises a welding gun 130 which is held in a horizontal attitude on the plate-like electrode with the welding tip fitted to a tip part thereof, a supporting member 140 to support the welding gun in a turning manner around a pivotably-supporting shaft provided at a fixed point between the tip part and a rear end part, and a pressure- applying member 150 which projects the rear end part of the welding gun upwardly, and turns the welding tip downwardly together with the welding gun.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resistance welding machine, and more specifically, it can perform welding even inside a metal box or metal frame structure in which a metal material such as a steel plate or a steel plate is assembled. The present invention relates to a structurally compact resistance welding machine in which a pressurizing mechanism for applying downward pressure during welding and a welding power source are arranged below the upper and lower electrodes.

[0002]

2. Description of the Related Art Generally, in metalworking, especially sheet metalworking, metal materials such as metal plates to be welded are superposed and energized, and the resistance heat generated by this energization is used as a heat source to heat and simultaneously apply a pressing force A resistance welding machine for welding is used, and thereby a metal structure such as a box or a frame is made. Among these resistance welding machines, a general one is a spot welding machine.

This spot welder has been proposed from a large one used for manufacturing an automobile body to a small stationary type used for sheet metal processing, etc., but technical improvements can be seen in the automobile body. It has been developed as a dedicated machine in the field of manufacturing, etc., and it is a stationary spot welding machine that is applied to the field of various small rod work pieces, and no other welding machine is found.

The stationary spot welding machine is a type of welding machine in which two metal materials are superposed and sandwiched by a pair of upper and lower electrodes to energize under pressure. This welding machine is composed of an upper electrode that descends from above and welds two metal materials by applying a pressure, and a lower electrode that is provided opposite to this and receives a pressure from above. With respect to the above, the pressurizing mechanism arranged above applies a downward pressing force.

This spot welder is incorporated as a part of a manufacturing line for automobile bodies and the like, and the metal material flowing through the line is conveyed to the spot welder where welding is performed.

On the other hand, if there is a place to be welded inside and the welded part cannot be directly pressed from the outside, such as a frame of a small rod or a box, it is difficult to make a line.
Whenever a need arises, it is carried to a welding machine and welded.

That is, in a structure having a complicated shape, the inside is often welded. At this time, the electrodes on the upper side and the electrode on the upper side are lowered and welded. I can't. In any case, the welding tips at the tips of the upper and lower electrodes have a squeezed shape, and if pressure is applied by such a squeezed spot, then in sheet metal working, etc. However, since the work of removing this is counted as one of the important works of sheet metal working, its improvement is desired.

At this time, the inventors of the present invention have previously confirmed that even if the structure has a small rod and a complicated shape, or a structure having a welded portion to be welded inside, We have proposed a method for welding and assembling a metal structure or an apparatus for welding and assembling a metal structure, which allows welding to be performed by selecting a welding position according to the welded portion, and even if work such as processing and assembling is required in connection with this welding. (See Japanese Patent Application No. 2001-022324)

In this device, the upper and lower electrodes are not constructed as so-called spot electrodes. That is, the lower electrode is composed of a flat conductive plate-shaped material, and the metal material can be processed and assembled on this plate-shaped material. Is a device for welding by lowering downward.

This device is preferable because the lower electrode is a plate-like work surface and the whole area thereof is energized so that it functions as an electrode and a metal material or a workpiece can be welded anywhere.

However, in this apparatus, since the downward pressure is applied by the upper electrode, the pressure mechanism for applying the downward pressure is necessarily provided on the upper electrode. For this reason, the device itself becomes large in size to hold the upper electrode and the pressurizing mechanism, which is said to be the biggest drawback, and the selling cost becomes high.

[0012]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned drawbacks, and is a welding machine having a structure in which the lower electrode can also be used as a work surface. We propose a welding machine with a compact structure that can be extracted from the power source such as the provided piston and cylinder mechanism.

[0013]

That is, according to the present invention, one electrode of a welding power source is connected to a plate electrode made of a flat plate material, and a welding tip is connected to the other electrode of the welding power source. In a resistance welding machine that performs resistance welding by pressing and energizing a work piece between this welding tip and the plate-shaped electrode, the welding tip is mounted on the plate-shaped electrode while being held in a horizontal position Welding gun, a supporting member for supporting the welding gun so as to rotate about a pivot shaft provided at a fixed point between the leading end and the rear end, and a rear end of the welding gun. Is pushed upward and the welding tip is pivoted downward together with the welding gun to pressurize the workpiece.

The structure and operation of these means will be described below in detail with reference to the drawings.

FIG. 1 is a front view of a resistance welding machine according to one embodiment of the present invention.

FIG. 2 is a front view of an embodiment of welding a workpiece by the resistance welding machine shown in FIG.

FIG. 3 is a front view of one embodiment for pressurizing and welding with the resistance welding machine shown in FIG.

First, in FIG. 1, reference numeral 100 generally indicates a resistance welding machine according to one embodiment of the present invention. 1, 2, and 3, reference numeral 110 is a welding power source, 120 is a plate-like electrode, 130 is a welding gun, and 13 is a welding gun.
1 is a welding tip, 140 is a support member, 141 is a pivot shaft,
Reference numeral 150 denotes a pressure member.

When the work W is welded by the resistance welding machine 100 shown in FIG. 1, the work W is the plate-shaped electrode 1.
The work piece W is placed on the work piece 20 and a desired pressing force is applied to the workpiece W downward by the welding tip 131 to resistance-weld a desired weld portion (not shown).

Whether the work W is a plate-like material as shown in FIG. 1 or a structure such as a metal box or frame in which the plate-like materials are assembled is welded at a predetermined position. It can be assembled and welded.

[0021] In summary, when making a metal box,
It is not necessary to assemble off-line, and the machining and assembly can be performed on the plate electrode 120 of the resistance welding machine 100, and welding can be performed when the need arises.

Therefore, the plate-shaped electrode 120 is made of a conductive plate-shaped material which is flat and as wide as possible, and one electrode 111 of the welding power source 110 is connected to it. Therefore, the surface of the plate-shaped electrode 120 acts as a work table or work surface.

For this reason, the structure is made flat so that any one of the surfaces serves as one electrode, and most of the entire surface or at least the central part including the central part is made of copper, aluminum or their alloys or other materials. It is composed of a conductive electrode metal plate, but the plate electrode itself is structured so as to have structurally sufficient strength so as to withstand the pressure applied during welding.

Further, from the welding power source 110, one electrode 1
The other electrode 112 is taken out together with 11. The other electrode 112 is connected to a welding tip 131 via a welding gun 130 as described later.

These two electrodes 111 and 112 are shown in FIG.
In FIG. 2, a plate-shaped support piece and a line segment of the passage route are shown, but in FIGS. 2 and 3, the energization route is shown as line segments 111 and 112 for convenience of description. In any case, these are generally shown from a conductive cable or the like, and show the same.

These two electrodes 111 and 112 are heated considerably by the energization during welding. Therefore, for example, the other electrode 112 is configured to be cooled by air cooling or the like as shown in FIG. 1, but the one electrode 111 can also be configured as an air cooling cable.

A resistance welding machine used for processing a steel plate such as so-called sheet metal processing is a spot welding machine or a seam welding machine. In this type of welding machine, the work W is placed between the upper and lower electrodes.
This is to weld by forming a jewel-shaped welded portion by sandwiching it. These two electrodes are configured as spot-shaped spot electrodes,
As a result, the pressing force and the amount of current are concentrated and increased.

On the other hand, the resistance welding machine 100 according to one embodiment of the present invention is a welding machine in which one of the upper and lower two electrodes corresponding to the lower side is constituted as the plate electrode 120, This is the type of welder proposed by the present inventors. This is different from a welding machine configured as a spot-shaped spot electrode such as a spot welding machine.

That is, the surface of the plate-shaped electrode 120 is energized over the entire surface, and it can be used as one electrode wherever the workpiece W is placed, and a pressing force is applied from the welding tip 131 corresponding to the upper electrode. Then, the workpiece W can be sandwiched and resistance-welded in between.

The other pole 112 of the welding power source 110 is connected to a welding tip 131, which serves as an upper electrode. The welding tip 131 is detachably held at the tip of a welding gun 130, and the welding gun 130 is held in a horizontal posture on a plate-shaped electrode 120 which constitutes a lower electrode.

The welding gun 130 provides an energization path and a cooling water supply path to the welding tip 131 and, as will be described later, constitutes one of pressing mechanisms for the welding tip 131 during welding. For this reason, the welding gun 130 is formed into a rod shape as described above, and the rod-shaped welding gun 130 is held in a horizontal posture.

A welding power source 110 is provided at the rear end of the welding gun 130.
The other electrode 112 is connected, and a current is taken into the welding tip 131 at the tip through this to conduct electricity. In this case, it is important to be held in the sideways posture, and in this posture, the direction of the upward pushing force can be changed by the pressing member 150, which can be transmitted later, and the force can be transmitted to the welding tip 131 as a pressing force. It can move freely on the plate electrode 120 as it is.

The welding gun 130 can be moved in the front-back direction with respect to the workpiece W (by the way, in FIG. 1, the left-right direction along the plane of the drawing) while being in the horizontal position, and is constructed in this way. In addition,
This moving mechanism can be configured in any way, for example, by setting the x and y axes on a plane and moving by a computer or numerical control.

When the welding gun 130 is moved to the left, for example, along the plane of FIG.
The welding tip 131 at the tip can be penetrated into the inside of a structure such as a metal box or a frame, and the vertical direction corresponding to the vertical movement path of the upper and lower electrodes of the conventional spot welder is closed. Even the work W having the structure can weld the internal welded portion without any trouble.

A pivot shaft 141 is provided at one fixed point between the front end and the rear end of the welding gun 130 held in a horizontal position. The pivot shaft 141 is supported by a support member 140, and the welding gun 130 is configured to be rotatable around the support member 140 as a fulcrum. With this configuration, even when an upward force is applied upward to the rear end portion of the welding gun 130, the upward force can be transmitted to the welding tip 131 at the tip portion by changing its direction as a downward pressing force. The position of the pivot 141 can be configured so that it can be adjusted as desired. According to this structure, the upward force acting on the rear end is the welding tip 13
1 can act as a large pressing force. That is, the force applied to the rear end portion of the welding gun 130 is applied to the workpiece W as a downward pressure force by changing the action direction to the welding tip 131 at the front end portion, and the applied pressure force is the pivot shaft 141. Can be increased by adjusting the position of the welding gun and the length of the welding gun 130.

That is, the welding gun 130, which is held on the plate-shaped electrode 120 in a horizontal orientation, is rod-shaped. A welding tip 131 is attached to the front end portion, and a pivot shaft 141 is provided through one fixed point between the front end portion and the rear end portion. The rear end portion is configured to be pushed upward by the pressing member 150 as described later. Therefore, the welding gun 130 turns around the pivot 141 as a fulcrum, the pressing member 150 serves as a lever and the welding tip 131 serves as a follower, and the effect as described above can be achieved.

Although the pivot shaft 141 for rotatably supporting the welding gun 130 in the lateral position can be supported by any mechanism, the pivot shaft 141 is supported by the support member 140, and the support member 140 is supported by the support base 142. Place it on top. The support base 142 itself is configured to be rotatable on a plane substantially parallel to the plate electrode 120. In other words, for example, at the time of welding, the welding tip 131 is configured to freely swivel on, for example, a plane parallel to the plane of FIG. 1 (plane parallel to the plate electrode 120). With such a configuration, no matter where the welded portion inside the workpiece such as the metal box or the frame is, the position of the welding tip 131 at the tip portion can be freely controlled only by operating the rear end portion of the welding gun 130. be able to.

As described above, since the welding gun 130 is structured to rotate about the pivot 141 as a fulcrum, when welding a metal box or the like, the welding gun 130 faces upward to the rear end portion exposed to the outside of the metal box. The force is deflected only by applying a thrusting force to the welding tip 131, and the welding tip 131 at the tip portion invading the inside of the metal box can apply a downward pressure force. Support member 140 for supporting
Can be swiveled on a plane parallel to the plate electrode 120, and the welding gun 1
30 can also freely swivel back and forth on parallel planes.

Therefore, even if the welding portion is inside the metal box, the welding tip 131 can be positioned at the position of the welding portion only by operating the rear end portion of the welding gun 130.

Although any means for applying an upward force to the welding gun 130 can be constructed, as shown in FIG.
The rear end portion of the welding gun 130 may be composed of a pressurizing member 150 which applies a pressurizing force from below and an elevating means for elevating the pressurizing member 150.

That is, the elevating means of the pressure member 150 is usually constituted by the piston / cylinder mechanism 151. When the pressurizing member 150 is raised by the piston / cylinder mechanism 151, the rear end of the welding gun 130 is pushed up to rotate about the pivot shaft 141 as a fulcrum, and the welding tip 13
1 presses down on the workpiece W by descending downward.

It is preferable that the pressurizing member 150 is normally constituted by the piston / cylinder mechanism 151, but the pressurizing member 150 may be one other than the piston / cylinder mechanism.
Any structure can be used as long as it can be applied with a lifting force. For example, a DC motor or a step motor can be used.

Further, in this way, the rear end portion of the welding gun 130 is pushed upward by the pressing member 150, the upward force is deflected, and a downward pressing force is applied to the welding tip 131 at the tip portion. Then, the piston / cylinder mechanism 151 that pushes up the pressing member 150 can be arranged even on a base (not shown) such as on the floor or on the ground or by being fixed to the base frame 152 shown in FIG. 1, for example. To repeat, the piston-cylinder mechanism 151 does not need to be provided above the welding tip 131 on the plate electrode 120, though it is a pressing mechanism that presses the welding tip 131 on the upper side downward. Further, there is no need for a supporting frame or a supporting device for supporting the piston / cylinder mechanism above the plate electrode 120.

When downward pressure is applied to the workpiece W placed on the plate electrode 120 from above by the welding tip 131, a piston / cylinder mechanism is provided above and a downward piston / cylinder mechanism is provided. It is customary to apply pressure. Rather, it is reasonable that the structure for applying downward pressure by the upper piston / cylinder mechanism is mechanically and in terms of transmission of pressure.

However, if the above-described structure is applied, as described above, in the welding machine in which the lower electrode is the plate-like electrode 120, the pressing force affects the weldability of the prime mover. The drive source such as the piston / cylinder mechanism becomes large, and accordingly, a strong support frame is required, and the welding machine itself becomes large and heavy.

When the lower electrode is composed of the plate-shaped electrode 120 made of a flat plate-shaped material, it is necessary to install a space larger than that of the conventional stationary spot welding machine. Further, the pressing force applied to the welding tip 131 by the piston / cylinder mechanism needs to be larger than that of a normal spot welding machine, and the piston / cylinder mechanism becomes large and heavy. Along with this increase in size and weight, the support frame for holding the piston / cylinder mechanism above it inevitably becomes large and strong.

Specifically, the supporting mechanism is a space
A supporting frame or a support of the piston / cylinder mechanism is erected around the plate-shaped electrode 120 taken by the frame, and a high pressing force is applied to this frame during welding. However, if the support mechanism is large in this way, the welder itself is also large, which is not preferable.

On the other hand, the welding machine 100 shown in FIG. 1 utilizes the welding gun 130 itself as a lever and pushes the rear end portion upward to apply pressure, so that the piston / cylinder mechanism 151 is downward, especially above the ground. Can be attached to the base or the base frame 152 arranged on it.
there is no problem.

Further, as described above, in order to push up the rear end of the welding gun 130 by the pressing member 150 to apply a pressing force, as shown in FIGS. 2 and 3, the lower surface of the welding gun 130 is A contact surface 132 is provided, and this contact surface 1
It is preferable to bring the top end of the pressing member 150 into contact with 32.

The contact surface 132 is not horizontal but the welding gun 130.
It is configured as an inclined surface that is inclined upward at the inclination angle θ ₂ toward the tip of the. When the contact surface 132 is formed as an inclined surface in this way, a uniform pressing force can be applied when welding the workpiece W, and the weldability can be improved.

When no pressure is applied to the workpiece W during welding, the welding gun 130 is almost parallel, as shown in FIG. At this time, the welding tip 1
31 is separated from the workpiece W, and the contact surface 132 at the rear end portion of the welding gun 130 is separated from the contact surface 132 without pushing up the pressing member 150. In this state, the pressing member 150 is lifted and pushed upward. When the pressing member 150 is pushed up to the contact surface 132, the welding tip 131 at the tip portion descends downward and comes into contact with the surface of the workpiece W, and the workpiece W is pressurized in the state shown in FIG. .

When the pressurized state shown in FIG. 3 is entered, the welding gun 1
The reference numeral 30 rotates about the pivot shaft 141 of the fulcrum, and the tip portion is inclined by the inclination θ ₁ . On the other hand, the contact surface 132 also rotates and tilts by the tilt angle θ ₂ . However, since the contact surface 132 is configured as an inclined surface that is inclined in advance by the inclination angle θ ₁ , the contact surface 13 is rotated by the inclination angle θ _2.
The pressing member 150 comes into contact with the member 2 in a state of being substantially orthogonal to its axis (that is, in a parallel state), and the upward force acts on the contact surface 132 on average.

In short, the welding gun 130 has a pivot 141
Even if the pressing member 150 is rotated about the center, the pressing member 150 comes into contact with the contact surface 132 in a parallel state during welding, and a uniform pressing force can be applied to the welding tip 131. In this case, it is preferable that the top of the pressing member 150 be spherically rounded.

When the support member 140 on which the pivot shaft 141 is supported is configured to be rotatable via the support base 142, the pressurizing member 150 is incorporated into the support base 102, which allows compact construction. In this case, the pressing member 150 penetrates the support base 142, and rotatably supports the rotation shaft 143 supporting the support base 142 via the bearing 144.

With this structure, the pressing member 150 is moved up and down by the piston / cylinder mechanism 151, while the support base 142 can freely rotate around the pressing member 150 and is supported via the support member 140. The welding gun 130 can freely swivel on a plane level.

[0056]

As described above, according to the present invention, one electrode of the welding power source is connected to the plate electrode made of a flat plate material, and the welding tip is connected to the other electrode of the welding power source. A resistance welding machine for carrying out resistance welding by sandwiching a workpiece between the welding tip and the plate electrode by applying pressure to the workpiece and holding it in a horizontal position on the plate electrode and welding tip at the tip. A welding gun to be mounted on, a supporting member for supporting the welding gun so as to rotate about a pivot shaft provided at one fixed point between the front end and the rear end, and a rear part of the welding gun. And a pressing member that pushes up the end portion upwardly and pivots the welding tip downward together with the welding gun to pressurize the workpiece.

Therefore, with the resistance welding machine according to the present invention, it is possible to perform welding even inside a metal box or metal frame structure in which a metal material such as a steel plate or a steel plate is assembled, and further downward during this welding. Since the pressurizing mechanism for applying a pressing force and the welding power source are arranged below the upper and lower electrodes, a structurally compact resistance welding machine can be constructed.

The lower electrode can also be used as a work surface, and the downward pressure applied by the upper electrode can be given from a power source such as a piston / cylinder mechanism fixed to the lower side, and the structure can be made compact and It is highly economical and can easily perform numerical control and remote control of the upper electrode operation and positioning.

[Brief description of drawings]

FIG. 1 is a front view of a resistance welding machine according to an embodiment of the present invention.

FIG. 2 is an explanatory view seen from the front of one mode when welding a workpiece by the resistance welding machine shown in FIG.

FIG. 3 is an explanatory view seen from the front of one mode when performing pressure welding by the resistance welding machine shown in FIG. 1.

[Explanation of symbols]

100 resistance welder 110 welding power source 120 plate electrode 130 welding gun 131 welding tip 132 contact surface 140 Bearing member 141 pivot 142 Support 150 pressure member 151 Piston / Cylinder mechanism 152 base frame W work

Claims (5)

[Claims] 1. A plate electrode made of a flat plate material is connected to one pole of a welding power source, and a welding tip is connected to the other pole of the welding power source. The welding tip and the plate electrode are connected. In a resistance welding machine that performs resistance welding by pressing and energizing a workpiece between and, a welding gun that is held in a horizontal posture on the plate-shaped electrode and has the welding tip attached to a tip end portion thereof, A support member for supporting the welding gun and a rear end portion of the welding gun are pushed upward so as to rotate the welding gun about a pivot shaft provided at one fixed point between the front end portion and the rear end portion. A resistance welding machine, comprising: a pressurizing member that presses the workpiece by rotating the welding tip downward together with the welding gun. 2. The resistance welding machine according to claim 1, further comprising a support base for supporting the support member and a rotation mechanism for rotating the support base. 3. A contact surface for contacting the top end of the pressure member is provided on the lower surface of the rear end of the welding gun, and the contact surface is inclined upward toward the tip of the welding gun. The resistance welding machine according to claim 1, wherein 4. The resistance welding machine according to claim 3, wherein an inclination angle of the contact surface is set so as to be horizontal or substantially horizontal when the welding tip comes into contact with a workpiece. 5. The pressurizing member is configured as an ascending / descending rod penetrating the support base, and a piston / cylinder mechanism is connected to a rear end of the ascending / descending rod.
And the resistance welding machine described in 2.