JP2668771B2 - Spot welding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION This invention is, for example two metal plates superimposed are welded body, while pressure held between a pair of welding electrodes, energizing these welding electrodes, generating Joule The present invention relates to a spot welder that heats and melts a metal plate by heat and welds it in spots.

[0002]

2. Description of the Related Art Spot welding is generally used for lap joints of relatively thin metal plates, similar to bolt tightening and rivet joining structures. This spot welding has a high joint efficiency because no holes can be formed in the metal plate, and a high pitch of oil, gas, or water can be obtained because the pitch can be reduced, and the surface precision of the objects to be welded is maintained. It has advantages such as In addition, spot welding requires small pits in places where stress concentration is severe due to a small slip coefficient, and the strength against peeling force or the strength against repeated loads in the peeling direction is inferior to that of the rivet joint structure. There is also a feature that the strength is not uniform.

[0003] A spot welder for performing spot welding having the above features includes a pair of welding electrodes for sandwiching a workpiece in a pressurized state, a power supply unit including a transformer for supplying a current to these welding electrodes, and a control unit. And the like.
The power supply unit is a single-phase AC type that is simple in structure, control or handling, a three-phase type that is advantageous for large-capacity machines, uses a secondary current that flows at that time while storing electrostatic energy in a capacitor and discharging it through a primary coil. It is classified into the energy storage type in which the welding is performed and the portable type in which the transformer and the electrode part are separated.

[0004] The control unit is responsible for controlling the current supply time to the welding electrode, the pressing force, and the like, and includes, for example, a current switching device, a conduction time control device, a sequence control device, and the like. There are three current switching devices, for example, an electromagnetic switch, a discharge tube switching device, or a mechanical switching device. In particular, the discharge tube control of the welding current by an ignitron is extremely effective.
The energization time control device is constituted by a timer. The sequence control device controls a series of operations such as sandwiching a body to be welded by a welding electrode, supplying a current to the welding electrode, and opening the welding electrode.

As the welding electrode, a material having high thermal conductivity and high conductivity is used. For example, a copper alloy electrode added with cadmium, chromium, titanium or beryllium is used. The shape of this welding electrode is appropriately selected according to the current distribution, the pressurization distribution of the object to be welded, or the cooling effect.
Sufficient management is also required for changes in shape due to
You. The shape of the welding electrode is, for example, a pointed tip.
Various types such as C-shaped, R-shaped round, and CF-shaped trapezoid
The condition is known. Also, the welding electrode has a cooling inside.
A passage for circulating air or water for
You.

[0006] Spot welding machine, it is necessary to pressure hold the welded member by a pair of welding electrodes is configured as a movable type in which freely separable these welding electrodes to each other. In this case, the spot welding machine generally uses one of the welding electrodes as a fixed type in order to position a welding portion with respect to the workpiece, and places the other welding electrode on the fixed side welding electrode by a driving mechanism such as an air cylinder. It is configured as a movable type that can be moved toward and away from each other. Therefore, according to such a spot welding machine, by moving the movable-side welding electrode to the fixed-type welding electrode side via the drive mechanism in a state where the fixed-side welding electrode is applied to the welding portion of the workpiece, accurately pressure sandwiching the welded member by a fixed side welding electrode and the movable welding electrode.

The principle of spot welding of the object to be welded proceeds as follows when a current is supplied to the welding electrode. That is,
The junction of the two superposed bodies to be welded is softened by a sharp rise in temperature due to the heat generated by the contact resistance. The softened joint portion is deformed by the pressure applied by the welding electrode to reduce the contact resistance, but the increased resistance of the base metal itself due to the temperature rise promotes heat generation and locally reaches the molten state. Then, after the supply of the current to the welding electrode is stopped, the joint is solidified by the pressing force from the welding electrode while being in close contact with each other, thereby completing the welding.

As described above, the welding electrode is internally provided with a cooling passage, which suppresses the temperature rise of the outer portion of the welded portion of the object to be welded and locally heats the welded portion. It is configured to melt.

[0009]

In the above-described spot welding machine, in order to improve welding efficiency or reliably weld the object to be welded, the pair of welding electrodes facing each other have their axes aligned with each other. the need to press clamping. Therefore, the movable welding electrode is configured to move so as to come into contact with and separate from the stationary welding electrode while holding the axis thereof.

[0010] The movable-side welding electrode is a fixed-side welding electrode in a state where two superposed workpieces are interposed between the welding electrodes, and the joint portion is applied to the fixed-side welding electrode. It moves to the electrode side, and also moves in a direction away from the fixed-side welding electrode after welding is completed, and this reciprocating operation is repeated thereafter. Therefore, it is desirable that the moving distance of the movable side welding electrode be the shortest in order to improve the efficiency of the welding operation. Since the spot welding machine is used exclusively for joining relatively thin metal plates, the maximum distance between the movable side welding electrode and the fixed side welding electrode conventionally corresponds to the capacity specification. It was set to the minimum required interval.

[0011] By the way, even if the metal plate to be welded has a relatively small thickness itself, a bent portion or the like of a flange portion or the like is applied to the front end portion, or the entire metal plate is formed to be curved. In some cases, the apparent thickness is configured to be large. The object to be welded is
A spot welding machine in which the distance between welding electrodes is set to a minimum necessary in accordance with the capacity specification cannot be inserted between welding electrodes. For this reason, a large spot welder had to be prepared for welding such an object to be welded. In addition, welding work with a large spot welder
There is a problem that work efficiency is deteriorated because it is necessary to reset work specifications such as current supply time, and the time for moving the welding electrode on the movable side is long.

Therefore, the present invention is capable of accurately performing spot welding on an arbitrary portion even in a bent portion such as a flange portion or a member having a large apparent thickness such as a member which is entirely curved. It was proposed for the purpose of providing a possible spot welding machine.

[0013]

SUMMARY OF THE INVENTION A spot welding machine according to the present invention, which achieves the above object, is arranged so as to face each other, and at least one side is moved toward and away from the other side so that the object to be welded can be moved. A pair of welding electrodes for pressing and holding are provided, and a head portion to which a movable-side welding electrode is attached is supported by a main body portion via a hinge mechanism which is rotatable in a direction orthogonal to an axis between the welding electrodes. Tomo When you configure
, The head part and the main body part, and
An air passage that circulates cooling air to the welding electrode
A connecting part for communication is provided, and the connecting part on the head side has an air
-Constructed by fitting an annular packing member at the open end of the passage
At the same time, at the connection part on the main body side,
A valve mechanism consisting of a ball and an elastic member is assembled
I do .

[0014] In addition, spot welding machine according to the present invention, the ratio
The head and body combined through the
Is located on the opposite side of the hinge mechanism
Both are located on the hinge mechanism side and
Elastic means for providing a turning return habit to the part side is provided.
This elastic means has both ends on the head and the main body, respectively.
By joining and fixing these head part and main body part
Constructed as a conductor for electrically connecting.

The elastic means is composed of a large number of thin copper alloy plates.
It is configured by stacking one sheet .

[0016]

According to the spot welding machine of the present invention constructed as described above, the head portion is rotated with respect to the main body portion via the hinge mechanism, so that the movable side welding electrode and the fixed side welding electrode are rotated. The space for inserting the body to be welded, which is formed between the welding electrode and the welding electrode, is formed not only in the preset opposing distance in the axial direction but also in the direction orthogonal to the axial direction.
Therefore, the spot welding machine is capable of connecting a welded object having a large apparent thickness such as a bent portion such as a flange portion or a member which is entirely curved to a movable side welding electrode and a fixed side welding electrode. It can be inserted between and to enable spot welding to the body to be welded.

Further, according to the spot welding machine of the present invention, the ball body of the valve mechanism is pushed by the annular packing member against the elastic force of the elastic member when the head portion is joined to the main body portion. When the head is rotated with respect to the main body, the ball is moved by the elastic force of the elastic member. Close the opening. Therefore, in a normal state, the spot welding machine supplies cooling air to the welding electrode to perform spot welding on the workpiece in a good state. In addition, the spot welding machine performs a head welding on a main body in order to perform spot welding on a welded body having a large apparent thickness such as a bent portion such as a flange portion or a member which is entirely curved. Even when the parts are rotated, the operation of temporarily stopping the air supply means is unnecessary, so that the work efficiency is not impaired and the spot welding of the object to be welded can be performed in a stable state.

Further, according to the spot welding machine of the present invention, even if the head portion is configured to be rotatable with respect to the main body portion, there is no inconvenience that the wiring structure and the like are complicated and the spot welding machine is relatively inexpensive. A simple structure can be obtained.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. The spot welding machine 1 is a relatively small-capacity hand-held spot welding machine, and includes a main body 2 in which a power transformer 3 is incorporated, and a base unit which is integrally provided on the upper surface of the main body 2, respectively. 4, a stand unit 5, a head 6 combined with the base unit 4, a movable-side welding electrode 7 attached to the head 6, and a fixed-side welding electrode 8 attached to the stand unit 5. Etc. are configured as main parts and members.

The main body 2 is formed in a substantially box-like shape by sandwiching the power transformer 3 between a pair of upper and lower chassis 2A and 2B formed in a rectangular dish shape. The upper chassis 2A and the lower chassis 2B are formed by, for example, aluminum die-casting having sufficient rigidity and insulation, and firmly expose a part of the outer peripheral portion of the power transformer 3 for heat radiation or the like. Are combined. The upper chassis 2A is provided with a protruding rectangular operation section 9 having a power switch, an air supply switch, and the like disposed on one side thereof, and is formed inside the main body 2 on the opposite side. Air supply pipe in cooling air passage,
An air intake portion 10 is provided in which connection pipes for connecting the exhaust pipes are exposed.

Although not shown, the main body 2 has a control section which controls the current supply time to the welding electrode, the pressurizing force, etc., and comprises, for example, a current switching device, a conduction time control device and a sequence control device. Is stored.

A first grip portion 11 is integrally provided on the bottom surface of the operation portion 9 so as to face the side surface portion of the body portion 2. Further, an inverted L-shaped second grip portion 12 is integrally projectingly provided on a side surface portion of the main body portion 2 that is orthogonal to the first grip portion 11. Therefore, the spot welding machine 1
The first grip portion 11 and the second grip portion 12 are firmly gripped by both hands, and spot welding is performed on the object to be welded.

The second of the upper chassis 2A constituting the main body 2
A hinge mechanism 1 for rotatably supporting a base unit portion 4 described later is provided on the side surface portion provided with the grip portion 12.
One of the hinge portions 13A forming part 3 is integrally formed. As is well known, the hinge portion 13A is configured by penetrating a support shaft through a pair of bearing walls facing each other. In addition, the upper chassis 2A is integrally provided with an inverted L-shaped engaging portion 14A that is located on the upper surface on the side facing the hinge portion 13A and that constitutes a locking mechanism 14 that locks and holds the base unit portion 4. The projection is formed.

A spring member 15 is provided in the main body portion 2 for imparting a habit of returning to the main body portion 2 side to a base unit portion 4 which is rotatably supported via a hinge mechanism 13.
Is provided. The spring member 15 is formed by laminating a large number of thin sheets of copper alloy having good conductivity, and one end of the spring member 15 is located below the hinge portion 13A constituting the hinge mechanism 13, and the upper chassis It is fixed to the side surface of 2A by screws. The other end of the spring member 15 is fixed to the head 6 as described later.

Although the detailed structure of the spring member 15 is omitted, the spring member 15 has a function of supplying a current output from a power supply control device or the like housed inside the main body 2 to a movable-side welding electrode rod 7 described later. doing. Therefore, the fixing portion of the main body 2 for fixing one end of the spring member 15 by screwing is configured as a current output terminal portion. A cover member 16 is attached to the main body 2 to cover the spring member 15 configured as a conductor.

The base unit portion 4 is provided with an overall cylindrical chassis made of, for example, die cast, and inside this chassis, an air cylinder (not shown) is housed and an air passage is formed. On one side surface portion of the base unit portion 4, a hinge portion 13B that constitutes the hinge mechanism 13 corresponding to the above-mentioned hinge portion 13A of the main body portion 2 is integrally provided. The hinge portion 13B includes an arm integrally projecting from the chassis from the base unit portion 4 toward the main body portion 2 side, and a bearing portion having a shaft hole in the width direction is formed at a tip portion of the arm.

The base unit 4 has a bearing portion located between bearing walls forming the hinge portion 13A of the main body portion 2,
By penetrating the support shaft through the shaft hole, the support shaft is rotatably supported by the main body 2. The base unit 4 is provided with an engaging member 14B that constitutes the locking mechanism 14 corresponding to the engaging portion 14A of the main body 2. The engaging member 14B is rotatably supported by a bearing portion having a substantially central portion integrally formed on an outer peripheral wall of a chassis constituting the base unit portion 4, and a wedge-shaped engaging portion is integrally formed on a lower end side. ing.

When the base unit 4 is assembled so as to be joined to the upper surface of the main body 2 via the hinge mechanism 13, the distal end engaging portion of the engaging member 14B is engaged with the engaging portion 14A of the main body 2. The combined state is maintained by the relative engagement with. In addition, the base unit 4
By rotating the engaging member 14B to release the engaged state between the engaging portion and the engaging portion 14A of the main body 2, the main body 2 is rotated sideways.

The base unit section 4 is, as described above,
Air is rotatably supported with respect to the main body portion 2, and air for cooling the movable welding electrode rod 7 or for driving an air cylinder incorporated therein is supplied from the main body portion 2 side. Therefore, an air connection portion 17 described later is provided at a joint portion between the base unit portion 4 and the main body portion 2.

The head 6 having a slightly smaller diameter is mounted on the upper part of the base unit 4 through a bellows mechanism 18. The head portion 6 is a member that is die cast from a copper alloy material, and is connected to a piston of an air cylinder (not shown) housed in the base unit portion 4. Therefore, when the drive air is supplied from the air supply device to the air cylinder, the head portion 6 moves upward due to the upward movement of the piston. When the return air is supplied from the air supply device to the air cylinder, the head portion 6 moves downward due to the downward movement of the piston.

Although not shown, the head portion 6 is provided with an air passage for supplying cooling air to a movable side welding electrode rod 7 which will be described later. Further, one end of the above-described spring member 15 is screwed and fixed to the head portion 6, so that the head portion 6 is electrically connected to a power supply control device housed in the main body portion 2 and receives a current.

The spring member 15 has such a length as to straddle the hinge mechanism 13 for rotatably supporting the base unit 4 on the main body 2 in a large arc shape. 6 is connected. Therefore, the spring member 1
Reference numeral 5 denotes a state in which the base unit 4 is elastically deformed when the base unit 4 is rotated with respect to the main body 2. The habit of turning back to is added.

The bellows mechanism 18 is made of a member formed of bellows made of rubber or the like, and prevents the supplied air from leaking when the head unit 6 moves up and down with respect to the base unit unit 4 so that the head unit 6 moves up and down. Is possible.

The movable side welding electrode rod 7 is firmly attached to the head part 6 at the upper end part by an attachment screw. Movable welding electrode rod 7 is substantially the same structure as the welding electrode rod provided in the conventional spot welder, thermal conductivity and high conductivity, such as cadmium, chromium, titanium or base Li helium or the like added It is made of a copper alloy. In the illustrated embodiment, the movable-side welding electrode rod 7 has an R-shaped tip portion, but needless to say, may have another shape. Further, the movable welding electrode rod 7 can be removed from the head portion 6 by removing a mounting screw, and is replaced when the tip portion is worn or the like after being used for a long period of time.

Although not shown, the movable-side welding electrode rod 7 is formed to be hollow throughout the axial direction to circulate cooling air therein. Supply pipe is inserted. The air supplied from the air supply pipe is evacuated through the gap formed between the air supply pipe and the hollow portion, and thus circulates inside the movable welding electrode rod 7. Therefore, as described later, workpieces which are pressurized sandwiched between the movable-side welding electrode rod 7 and the fixed side welding electrode rod 8 is spot welded, movable welding electrode rod in which these cooling air is supplied Only the welded portion where the electrode 7 and the fixed-side welding electrode rod 8 come into contact is in a high-temperature state, so that the peripheral portion is prevented from becoming hot.

The stand unit section 5 is erected and supported on the upper surface of the main body section 2 via a base section 19. The stand unit section 5 is mounted in the state has has a length which is located above the front end of the movable welding electrode rod 7 described above, the tip portion arm member 20 in the horizontal direction in the vicinity piece Has been. The free end of the arm member 20 is located above the movable-side welding electrode rod 7, and the fixed-side welding electrode rod 8 is attached thereto.

The stand unit 5 is a member formed by subjecting a surface of a metal pipe material to insulation treatment. Inside the stand unit 5, a conducting wire for supplying a current to the fixed-side welding electrode rod 8, an air passage for cooling, and the like are provided. Is provided. Arm member 2
Numeral 0 is formed of a conductive metal pipe material whose both ends are closed, and a conductive wire for supplying a current to the fixed-side welding electrode rod 8 or a cooling air passage is provided inside. . Fixed side welding electrode rod 8, like the movable welding electrode rod 7, thermal conductivity and high conductivity, such as cadmium, chromium, and is formed of copper alloy obtained by adding titanium or base Li helium or the like as the material . The fixed-side welding electrode rod 8 is also configured such that the tip portion has an R shape in the illustrated embodiment.

Although not shown, the fixed-side welding electrode rod 8 is formed hollow throughout the entire area in the axial direction to circulate cooling air therein. The air supply pipe is inserted. The air supplied from the air supply pipe is exhausted through a gap formed between the air supply pipe and the hollow portion, and circulates inside the movable-side welding electrode rod 7. Therefore, as will be described later, the movable-side welding electrode rod 7
Is pressurized sandwiched between the fixed side welding electrode rod 8 and the workpieces to be spot welded, a movable welding electrode rod 7 which these cooling air is supplied and the fixed side welding electrode rod 8 is in contact welding Only a part becomes a high temperature state, and the high temperature of the peripheral part is prevented.

Fixed side welding electrode rod 8 and movable side welding electrode rod 7
And are configured to be supported by the stand unit portion 5 and the base unit portion 4, respectively, with their axes aligned. In this way, the configuration in which the fixed side welding electrode rod 8 and the movable side welding electrode rod 7 have the same axis
It is extremely important for spot welding the welded body 21 with good accuracy and in a good condition.

In the spot welding machine 1 constructed as described above, the return air is supplied from the air supply device to the air cylinder to lower the head portion 6 so that the fixed side welding electrode rod 8 and The distance between the movable welding electrode rod 7 and the movable welding electrode rod 7 is widened. A welded body 21 composed of two metal plates 21A and 21B to be welded is inserted between the fixed-side welding electrode rod 8 and the movable-side welding electrode rod 7, and the fixed-side welding electrode rod 8 Is applied.

Thereafter, when the driving air is supplied from the air supply device to the air cylinder, the head section 6 moves upward, and moves the movable-side welding electrode rod 7 attached to the tip portion along the axis to the fixed-side welding electrode. It is moved to the rod 8 side.
The moving operation of the movable-side welding electrode rod 7 is stopped in a state where the welding-target body 21 is pressurized with the fixed-side welding electrode rod 8 with a predetermined pressing force. Welded body 21, as shown in FIG. 2, is sandwiched under pressure by the movable welding electrode rod 7 and the fixed side welding electrode rod 8.

When electric current is supplied from the power supply to the movable welding electrode 7 and the fixed welding electrode 8, the workpiece 21 is welded to the movable metal electrodes 20 A and 20 B. The temperature of the contact portion between the electrode rod 7 and the fixed-side welding electrode rod 8 sharply rises due to the heat generated by the contact resistance, and the softened state. The softened joints of the metal plates 20A and 20B are deformed by the pressing force between the fixed-side welding electrode rod 8 and the movable-side welding electrode rod 7 to reduce the contact resistance, but the resistance of the base material itself increases due to the temperature rise. Due to the heat generation, the molten state is locally reached.

Then, even after the current supply to the movable-side welding electrode rod 7 and the fixed-side welding electrode rod 8 is stopped, the to-be-welded body 21 is maintained by the movable-side welding electrode rod 7 and the fixed-side welding electrode rod 8. since a state of being pressurized pinching, welding is completed by solidifying while adhesion. Thereafter, the returnable air is supplied from the air supply device to the air cylinder, and the head 6 moves downward, so that the movable-side welding electrode rod 7 attached to the distal end is fixed along the axis. Since it moves in the direction away from the side welding electrode rod 8 side, it is taken out from the spot welding machine 1 of the embodiment.

In the conventional spot welding machine, the distance dimension H between the movable-side welding electrode rod 7 and the fixed-side welding electrode rod 8 was regulated along with the conditions such as the power source specifications. That is, the welded body 21 includes the movable side welding electrode rod 7 and the fixed side welding electrode rod 8.
Since the spot welding is performed in a state of being pressurized held between, it must be the insertable thickness thereof and movable welding electrode rod 7 between the fixed side welding electrode rod 8.

The spot welding machine 1 has a thickness dimension H between the movable welding electrode 7 and the fixed welding electrode 8.
Which has a bent flange portion or the like on the insertion end side, and cannot be inserted between the movable-side welding electrode 7 and the fixed-side welding electrode 8. Spot welding can be performed even on the workpiece 21. The spot welding machine 1 according to the embodiment is configured such that the base unit 4
Is rotated.

The movable welding electrode rod 7 is moved to the side portion of the fixed welding electrode rod 8 as shown in FIG. 5 by rotating the base unit portion 4 with respect to the main body portion 2.
Therefore, the movable side welding electrode rod 7 and the fixed side welding electrode rod 8
The facing distance W between and can be set larger than the distance H in the normal state because the movable welding electrode rod 7 moves laterally. The object to be welded 21 thus has the facing distance W.
Movable side welding electrode rod 7 and fixed side welding electrode rod 8 set to
Inserted between

The spot welding machine 1 has an air supply source provided in the main body 2 and an air passage formed on the movable side welding electrode rod 7 through an air passage formed in communication with the base unit 4 and the head 6. Cooling air is supplied into the passage. The air passage is divided between the base unit 4 and the main body 2 when the base unit 4 is rotated with respect to the main body 2. However,
The air connecting portion 17 formed at the joint between the base unit 4 and the main body 2 is configured to close the air passage even when the base unit 4 is rotated with respect to the main body 2. Therefore, it is not necessary to stop the air supply source.

As shown in FIGS. 6 and 7, the air connecting portion 17 is composed of an air connecting portion 17A on the main body portion 2 side and an air connecting portion 17B on the base unit portion 4 side. The air connecting portion 17B is composed of an annular packing member 23 fitted into an opening of an air passage 22B formed inside the base unit portion 4. The annular packing member 23 is attached to the main body 2 in a state of slightly protruding from the surface of the joint. Further, in the annular packing member 23, the through hole 23A at the central portion has an inner diameter dimension slightly smaller than a diameter dimension of a ball member 25 described later.

On the other hand, the air connection portion 17A is composed of a coupling member 24 fitted into an opening of an air passage 22A formed inside the main body 2, a ball member 25 and a coil spring 26. That is, the counterbore 27 is provided at the opening of the air passage 22A so as to increase the opening diameter, and the inner peripheral screw 2 is provided on the inner peripheral wall thereof.
8 are formed. A coil spring 26 and a ball member 25 are housed in the counterbore 27, and the coupling member 2 is compressed by compressing the coil spring 26.
4 is screwed into the inner peripheral screw 28.

The coupling member 24 has a through hole 24A at the center. The inner diameter of the through hole 24A is slightly smaller than the diameter of the ball member 25 and slightly larger than the inner diameter of the through hole 23A of the annular packing member 23. Therefore, the ball member 25
In the state where the coupling member 24 is screwed into the inner peripheral screw 28, as shown in FIG. 6, the elastic force of the coil spring 26 causes a part of the outer peripheral portion to project and be exposed from the through hole 24A. In this case, the ball member 25 has the through hole 2
By closely contacting the inner peripheral wall of 4A, the air passage 22A
Close the opening. As described above, the coupling member 24, the ball member 25, and the coil spring 26 constitute a kind of valve mechanism.

Embodiment The spot welding machine 1 is provided with the air connection 17 constructed as described above at the joint between the main body 2 and the base unit 4 so that the base unit 4 can be connected to the upper surface of the main body 2. And the air passage 22 of the main body 2 in the state of being locked and held by the locking mechanism 14.
A and the air passage 22B on the base unit 4 side are in communication with each other. That is, the annular packing member 23
Is in contact with the surface of the coupling member 24 when the base unit 4 is joined to the main body 2. The outer periphery of the ball member 25, which is projected and exposed from the through hole 24 </ b> A of the coupling member 24, is pressed by the annular packing member 23 and is pushed into the counterbore 27 against the elastic force of the coil spring 26. .

The air passage 22A on the main body 2 side is closed by the ball member 25 being pressed against the inner peripheral wall of the through hole 24A of the coupling member 24 by the elastic force of the coil spring 26, as described above. Since the ball member 25 is pushed into the counterbore 27 against the elastic force of the coil spring 26 by the annular packing member 23, the closed state is released and the ball member 25 communicates with the air passage 22B of the base unit 4 side. . Therefore, the air supplied from the air supply source is supplied from the main body 2 to the base unit 4, and is supplied via the head 6 to the movable welding electrode rod 7 or the air cylinder housed in the base unit 4. Supplied.

As described above, the air passage 22A on the main body portion 2 side is provided when the base unit portion 4 is rotated with respect to the main body portion 2 in order to perform spot welding on the welded body 21 having a special specification. Are closed at the air connection 17. That is, the ball member 25 is moved from the state in which the ball member 25 is pushed into the counterbore 27 by the annular packing member 23 and communicates with the air passage 22B on the base unit portion 4 side. The ball member 25 is released from the pressed state against the ball member 25.
Is closed by being pressed against the inner peripheral wall of the through hole 24A of the coupling member 24 by the elastic force of the coil spring 26.

In the spot welding machine 1 of the embodiment, the air passage 22A on the main body 2 side in the state where the base unit 4 is rotated with respect to the main body 2 as described above.
Is automatically closed, so that the air supply source is not stopped.

The spot welding machine 1 of the above-described embodiment is constituted by the head unit 6 which supports the electrode unit on the base unit portion 4 in which the air cylinder is housed 4 and the movable welding electrode rod 7; Needless to say, the head unit 6 and the head unit 6 may be integrated.

[0056]

As described above in detail, according to the spot welding machine of the present invention, the head part is pivoted with respect to the main body part through the hinge mechanism, so that the welding electrode on the movable side can be formed. The space for inserting the welded object formed between the fixed side welding electrode and the space to be inserted can be expanded not only in the preset interval in the axial direction but also in the direction orthogonal to the axial direction. For a specially-welded body whose apparent thickness dimension is large, such as a bent portion such as a flange portion or a member that is entirely curved, a movable-side welding electrode and a fixed-side welding electrode are used. Since it can be inserted between the two, spot welding can be performed on the body to be welded.

According to the spot welding machine of the present invention, the head is movably supported with respect to the main body, and is opened and closed by an annular packing member provided on the head in the air passage on the main body side. By providing a valve mechanism to operate, even if the head part is rotated to perform spot welding on a specially shaped workpiece, it is not necessary to stop and restart the air supply source, improving work efficiency. In addition, spot welding can be performed in a stable state. Furthermore, according to the spot welding machine of the present invention, even if the head portion is configured to be rotatable with respect to the main body portion, there is no disadvantage that the wiring structure and the like are complicated, and a relatively simple structure is provided. can do.

[Brief description of the drawings]

FIG. 1 is a front view of a spot welding machine according to the present invention.

FIG. 2 is a rear view of the spot welding machine.

FIG. 3 is a side view of the spot welding machine.

FIG. 4 is a rear view of the spot welding machine with a cover covering a spring member opened.

FIG. 5 is a rear view of the spot welding machine in a state where a base unit is rotated.

FIG. 6 is a longitudinal sectional view illustrating a configuration of an air connection portion provided at a joint portion between a main body portion and a base unit portion in the spot welding machine.

FIG. 7 is an exploded perspective view illustrating the configuration of the air connecting portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Spot welding machine 2 ... Main body part 3 ... Power transformer 4 ... Base unit part 5 ... Stand unit part 6 ... Head part 7 ... Movable side welding electrode rod 8.・ ・ Fixed side welding electrode 13 ・ ・ Hinge mechanism 14 ・ ・ Locking mechanism 15 ・ ・ Spring member 17 ・ ・ Air connection part 21 ・ ・ Welded body 22 ・ ・ Air passage 23 ・ ・ Ring packing member 24 ・ ・ Cup Ring member 25 Ball member 26 Coil spring

Claims (3)

(57) [Claims] A pair of welding electrodes arranged opposite to each other and at least one side of which is moved toward and away from the other side is provided, and the workpiece is welded while being pressed and held by these welding electrodes. A spot welding machine, wherein a head portion to which a movable-side welding electrode is attached is supported by a main body portion via a hinge mechanism that is rotatable in a direction orthogonal to an axis between the welding electrodes, thereby forming the head portion. in a state but which is rotational movement, in the spot welder opposing distance between the welding electrode of the welding electrode of the movable fixed side is extended, the head portion and the body portion, a small on opposite joint transfected
Is installed in the cooling air passage provided in each welding electrode.
Air passage for circulating air supply
The air connection part on the head side is provided.
Has an annular packing member fitted to the open end of the air passage.
The air passage is opened at the connecting part on the main body side.
Attach a valve mechanism consisting of a ball and an elastic member to the mouth
With the head part joined to the body part
Then, the ball body of the valve mechanism resists the elastic force of the elastic member.
Air is pushed in by the gasket-shaped packing
-The passage and the air passage on the main unit side are in communication,
In the state where the head part is rotated with respect to the main body,
The air passage opening by the elastic force of the elastic member.
Spot welding machine characterized by closing . (2) being arranged to face each other and at least
A pair of welding electrodes, one of which is moved toward and away from the other
Poles, and pressurized and sandwiched by these welding electrodes
A spot welding machine that welds a workpiece,
The head to which the welding electrodes are attached is
Via a hinge mechanism that can rotate in the direction orthogonal to the axis
The head is rotated by supporting the
When the welding electrode on the movable side is
In spot welding machines where the facing distance to the contact electrode is extended
Head and body combined via a hinge mechanism
The part has a locking mechanism located on the opposite side of the hinge mechanism
And located on the hinge mechanism side,
Elastic means to impart rotation return behavior to the body
This elastic means has a head and a book at each end.
By joining and fixing the body, these heads and
A spot welding machine characterized in that it is configured as a conducting wire for electrically connecting a main body . 3. The elastic means laminates a plurality of copper alloy thin plates.
The spot welding machine according to claim 2, wherein the spot welding machine is configured as described above.