JP2003039171A - Stud welding gun - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stud welding gun capable of surely holding a stud, holding corresponding to a stud with a difference diameter, and corresponding without adjusting the length of or exchanging the stopper pin even with a different length. SOLUTION: Chuck nails 48 are made expandable/contractable in the direction mutually attaching/detaching, and the chuck nails hold the stud with the holding force acting from a holding cylinder 66 through a link mechanism 56. By expanding/contracting of the chuck nails 48, holding of a stud with a different diameter becomes possible. A stopper pin 50 moves in the longitudinal direction, and can correspond to a stud with a different length. When a lever 84 is tilted to be in the biting position, the hole rim of a insertion hole of the lever 84 bites a stopper pin 50 to fix the stopper pin 50.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stud welding gun used for gripping a stud and pressing it against a work to weld it.

[0002]

2. Description of the Related Art A conventional stud welding gun 11 is shown in FIG.
An example of No. 2 is shown in cross section.

In this stud welding gun 112, a chuck 116 having an inner diameter matching the outer diameter of the stud 114 is provided.
And a stopper pin 118 having a length matching the length of the stud 114. The stud 114 has
The pressure force from the pressure spring 120 acts while being held by the chuck 116.

Further, in this stud welding gun 112,
It has a work retainer 122 whose tip contacts the work during welding. The tip of the work holder 122 is brought into contact with the work to press the stud welding gun 112, and the compression spring 12
No. 4 is welded in a compressed state. Therefore, if the stud welding gun 112 is separated from the work after welding, the compression spring 1
The spring force of 24 acts on the work via the work holder 122, and lifting of the work is prevented.

However, the stud 114 is attached to the chuck 116.
Since the stud 114 is pushed in when it is mounted on, the holding force may become unstable depending on the relationship between the stud 114 and the chuck 116, and the welding strength may vary. Also, the stud 114 for the chuck 116
Repeated pressing and pulling after welding will cause chuck 1
16 may be worn and the holding force of the chuck 116 may be reduced.

In addition, since the chuck 116 has a dedicated shape adapted to a specific stud 114, it is necessary to change the chuck 116 when the outer diameter of the stud 114 changes, for example. Also, after welding, the chuck 116
Holds the stud 114, the work holder 112 and the compression spring 124 prevent the work from being lifted.
Is required.

Further, if the length of the stud 114 changes,
It is also necessary to adjust or replace the length of the stopper pin 118.

[0008]

SUMMARY OF THE INVENTION In consideration of such a fact, the present invention provides a stud that can surely grip a stud, can also grip studs having different diameters, and have different lengths. Also, it is an object to obtain a stud welding gun which can be used without adjusting or replacing the length of the stopper pin.

[0009]

According to the first aspect of the present invention, between the contracted position where the stud having the assumed minimum diameter is gripped in the radial direction and the expanded position where the stud having the assumed maximum diameter is opened. A gripping member that can be expanded and contracted, an expansion and contraction device that moves the gripping member in the expansion and contraction direction and exerts a gripping force, and a stopper pin that is movably arranged in the gripping member in the same direction as the longitudinal direction of the stud, Fixing means for immobilizing the stopper pin in the gripping member in its longitudinal direction in a state where the stud is gripped by the gripping member.

That is, the gripping member is expanded and contracted between the contracted position and the expanded position by the expansion and contraction device, and in the contracted position, even a stud having an assumed minimum diameter receives the gripping force from the expansion and contraction device and is radially moved. Can be gripped. Therefore, by inserting the stud with the gripping member appropriately enlarged from the contracted position and applying a gripping force by the expansion / contraction device, the maximum diameter stud or the intermediate diameter between the minimum diameter stud and the maximum diameter stud is applied. Even a stud having a diameter of 10 mm can be surely gripped. Further, since the gripping member opens even the stud with the maximum diameter assumed in the expanded position, it is not necessary to push the stud into the gripping member even when gripping the stud with the maximum diameter, and the stud is pulled out after welding. There is no need. Therefore, wear of the gripping member is prevented, and a decrease in gripping force can be prevented. Moreover, by releasing the stud by the gripping member after welding, it is possible to prevent the work from being lifted up when the stud welding gun is separated from the work, so that the conventional work pressing or the like becomes unnecessary.

Further, in this stud welding gun, the stopper pin is movable in the same direction as the longitudinal direction of the stud, and when the stud is grasped by the grasping member, the stopper pin is moved in the longitudinal direction by the fixing means. Impossible. Therefore, even studs of different lengths can be dealt with by adjusting the position of the stopper pin and adjusting it or replacing it.

According to a second aspect of the present invention, in the first aspect of the invention, the expansion / contraction device has a gripping cylinder that exerts a predetermined gripping force in the same direction as the longitudinal direction of the stud, and the gripping cylinder. A link mechanism for converting the gripping force of the cylinder into the expansion / contraction direction of the gripping member.

Therefore, the gripping force of the gripping cylinder is converted by the link mechanism in the expansion / contraction direction of the gripping member, so that the gripping member expands / contracts and the stud can be gripped. Since the gripping cylinder is arranged so as to exert a gripping force in the same direction as the longitudinal direction of the stud, it does not take up space in the expansion / contraction direction of the gripping member, and it is possible to achieve miniaturization as a stud welding gun. .

According to a third aspect of the present invention, in the invention according to the first or second aspect, a gun main body is configured to include the grip member, the expansion / contraction device, and the fixing means.
A holding member for holding the gun body so as to be movable in the longitudinal direction of the stud.

Thus, by moving the gun body in the longitudinal direction of the stud with respect to the holding member, the gripping member, the expansion / contraction device and the fixing means can be moved integrally.

According to a fourth aspect of the invention, in the third aspect of the invention, the fixing means is formed with an insertion hole through which the stopper pin is inserted, and by moving the gun body with respect to the holding member, A fixing member that moves a biting position where the hole edge of the insertion hole bites into the stopper pin and a non-biting position that eliminates the biting state,
It is characterized in that it is configured to include.

Therefore, with the gripping member holding the stud, the fixing member comes into the biting position by the movement of the gun body with respect to the holding member. At the biting position, the hole edge of the insertion hole formed in the fixing member bites into the stopper pin, so that the stopper pin can be fixed to be immovable in the longitudinal direction. Further, when the fixing member comes to the non-bite position due to the movement of the gun body with respect to the holding member, the bite state is canceled, and the stopper pin can move in the longitudinal direction.

Thus, the stopper pin can be easily fixed and released by simply moving the gun body.

[0019]

1 (A) and 1 (B) show the overall structure of a stud welding gun 12 according to an embodiment of the present invention. 2A and 2B, the gun body 14 is shown in an enlarged manner. In the following, for convenience of illustration, the stopper pin 50 and the stud 46, which will be described later, are arranged such that the longitudinal directions thereof are vertically arranged, but the orientation of the stud welding gun 12 is not limited to this.

As shown in FIG. 1, the stud welding gun 12
Has a gun body 14 and a first cylinder plate 16 to which the gun body 14 is slidably mounted. An air cylinder 18 for raising and lowering the gun body is attached to the upper portion of the first cylinder plate 16. The air cylinder 18 is the second cylinder plate 2
0 is connected to the gun body 14 through the gun body 1
4 can be moved up and down with respect to the first cylinder plate 16 (in the direction of arrow A and in the opposite direction).

An absorber 24 is attached to the first cylinder plate 16 via an absorber bracket 22. When lowering the gun body 14, the stopper block 26 attached to the gun body 14 is moved to the absorber 24.
Then, the lower end of the gun body 14 is positioned within a fixed range.

As shown in FIGS. 2A and 2B, the gun body 14 includes a cylinder plate 30 arranged in parallel.
And a horizontal base 32, and a vertical base 34 connecting them.
A substantially U-shaped base member 28 constituted by
have. A base insulating plate 40 is attached to the vertical base 34 to insulate the base member 28.

A pair of horizontal movement guides 36 are attached to the upper surface of the horizontal base 32. Each of the horizontal movement guides 36 moves in the horizontal direction (the direction of arrow B in FIG. 2B and the opposite direction) along the guide rail 38,
Close to or away from each other.

Between the horizontal movement guides 36, a pair of vertical movement guides 44 are provided via slide brackets 42.
And the lower portion of the vertical movement guide 44 extends downward through a hole formed in the horizontal base 32. The vertical movement guide 44 is held by the slide bracket 42 so as to be vertically movable.

A pair of chuck claws 48 for holding the studs 46 (see FIGS. 4, 5 and 7) are arranged between the vertical movement guides 44, and are fixed to the corresponding vertical movement guides 44. There is. Therefore, when the horizontal movement guide 36 approaches or separates, the vertical movement guide 44 also approaches or separates, and the chuck claw 48 also approaches or separates accordingly.

The shapes and intervals of the chuck claws 48 are in the closest state so that the stud 46S (see FIG. 4B) having the smallest diameter expected to be used in the stud welding gun 12 can be gripped. Then the smallest diameter stud 46
In the state in which the diameter is smaller than the outer diameter of S and is most separated, the stud 46L is separated from the maximum diameter stud 46L (see FIG. 5B) that is supposed to be used in the stud welding gun 12 (that is, the maximum diameter stud). (There is a space wider than the outer diameter of 46 L).

A stopper pin 50 is arranged between the chuck claws 48. The stopper pin 50 is shown in FIG.
As shown in FIG. 5, even if the chuck claw 48 is closest to the chuck claw 48, it has a predetermined diameter so that the chuck claw 48 will not be inadvertently contacted or interfered with the chuck claw 48 to affect the grip of the stud 46. . Further, a stopper pin guide 52 is attached to the horizontal base 32 to prevent the stopper pin 50 from moving in the lateral direction and hold it so as to be movable in the vertical direction (that is, the longitudinal direction). A set collar 54 is attached to a substantially middle portion of the stopper pin 50 in the vertical direction so that the stopper pin 5 is substantially
The diameter 0 is partially expanded, and the downward movement of the stopper pin 50 is limited to a certain range by the set collar 54 hitting the stopper pin guide 52.

A link mechanism 56 is arranged in the base member 28. As shown in detail in FIG. 6, the link mechanism 56 is arranged along the vertical direction, and has a vertically movable clamp shaft 58 and an upper end thereof connected to a lower end of the clamp shaft 58 by a hinge pin 62. And a pair of expansion / contraction links 60. Scale link 6
The lower ends of 0 extend in directions away from each other and are connected to the knuckle 64 by hinge pins 62, and are moved toward or away from each other by the vertical movement of the clamp shaft 58. The knuckle 64 is fixed to the horizontal movement guide 36. Therefore, when the clamp shaft 58 moves up and down, the horizontal movement guide 36 also approaches or separates.

A gripping cylinder 66 is attached to the upper surface of the cylinder plate 30, and is connected to the clamp shaft 58 via a joint 68. Therefore, by driving the gripping cylinder 66, the clamp shaft 58 is moved up and down, and the horizontal movement guide 36 and the vertical movement guide 4 are moved.
4 and the chuck claw 48 can be brought close to or separated from each other.

The clamp shaft 58 is held by a linear bush 70 fixed to the vertical base 34, and is designed to smoothly move up and down without wobbling in the lateral direction. The link mechanism 56 and the gripping cylinder 66 constitute the expansion / contraction device of the present invention.

In order to move the horizontal moving guide 36, the vertical moving guide 44, and the chuck claw 48 closer to each other or to move them apart, the gripping cylinder 66 is moved in the same direction (that is, the horizontal direction). However, in the stud welding gun 12 of the present embodiment, the gripping cylinder 66 is arranged in the same direction as the longitudinal direction of the stud 46 so that the gripping cylinder 66 does not project in the expansion / contraction direction. The stud welding gun 12 is downsized.

Further, in the base member 28, as shown in FIG.
As shown in (A) and (B), the cylinder plate 3
The pressurizing unit 72 is arranged between 0 and the slide bracket 42. The pressing unit 72 includes a substantially box-shaped spring receiver 74 that accommodates the upper portion of the stopper pin 50, and a pressing spring 76 that is arranged between the spring receiver 74 and the cylinder plate 30. The pressing force of the pressure spring 76 acts on the vertical movement guide 44 and the chuck claw 48 via the spring receiver 74 and the pressure block 78.
Further, as shown in FIG. 7, the pressing force of the pressure spring 76 is
It also acts on the stopper pin 50 via a pressing piece 102 arranged in the spring receiver 74 and a lever 84 described later.

A pressure cylinder 80 is attached to the upper surface of the cylinder plate 30, and a piston 82 of the pressure cylinder 80 penetrates the cylinder plate 30 and is connected to an upper end of a pressure spring 76. By adjusting the pressurizing force of the pressurizing cylinder 80 (position of the piston 82), the accumulating force of the pressurizing spring 76 can be adjusted. During welding, an appropriate acceleration and pressing force act on the stud by the stored force of the pressure spring 76.

A lever 84 is arranged in the spring receiver 74. As shown in detail in FIGS. 7A and 7B,
The lever 84 is formed in a plate shape having a fixed length, and one end 84 </ b> A side thereof projects outside from a guide hole 86 formed in the spring receiver 74. The other end 84 of the lever 84
An insertion hole 88 is formed on the B side, and the insertion hole 88 is formed.
The stopper pin 50 is inserted therethrough. Insertion hole 88
The inner diameter of is slightly larger than the outer diameter of the stopper pin 50, and as shown in FIG. 7 (B), when the lever 84 is orthogonal to the stopper pin 50 (non-cutting position), the insertion hole The hole edge of 88 does not contact the outer circumference of the stopper pin 50. On the other hand, as shown in FIG. 7A, when the lever 84 is tilted by a certain angle or more (the biting position), the hole edge of the insertion hole 88 is the stopper pin 5.
Stopper pin 5
It is possible to prevent the movement of 0 in the longitudinal direction. Lever 8
In the inclination range (inclination angle) of No. 4, the one end 84A side is the guide hole 8
By moving within 6, it is limited to a certain range.

A spring case 90 is arranged at the bottom of the spring receiver 74, and a lever urging spring 92 is accommodated therein. The upper end of the lever biasing spring 92 is in contact with a substantially middle portion of the lever 84 from below, and the lever 84 is biased from the non-bite position to the bite position.

As shown in FIGS. 2 to 5, the spring case 9
A compression spring 94 is arranged between 0 and the set collar 54. The compression spring 94 is formed so as to have a spring force smaller than that of the lever biasing spring 92.
4, the set collar 54 and the stopper pin 50 are urged downward.

As shown in FIGS. 1A and 1B, the first
A dog 96 is fixed to the cylinder plate 16. The dog 96 does not come into contact with the lever 84 as shown in FIG. 7 (A) when the gun body 14 is descending, but when the gun body 14 is raised, as shown in FIG. 7 (B). The one end 84A of the lever 84 is fixed at a predetermined position so as to come into contact with the dog 96 and be pushed relatively downward. Therefore, the lever 84 resists the urging force of the lever urging spring 92 when the gun body 14 is elevated.
Since it is pushed down to 6 and is in the non-cutting position,
The stopper pin 50 can move up and down. On the other hand, when the gun body 14 descends and the dog 96 separates from one end of the lever 84, the lever 84 is inclined by the urging force of the lever urging spring 92 to the biting position, and thus the stopper pin 5
Vertical movement of 0 is prevented.

A power cable 98 is connected to the gun body 14, and a predetermined electric power can be supplied by energizing at the time of welding to generate an arc between the stud 46 and the work. As shown in FIG. 1A, an intermediate portion of the power cable 98 is held by a holder 100 attached to the stopper block 26.

Next, the stud welding gun 12 of the present embodiment.
The action of will be explained.

When welding is performed using this stud welding gun 12, first, the gun body 14 is raised. In this state, as shown in FIG. 7B, one end of the lever 84 is pushed by the dog 96 and the lever 84 is in the non-cutting position, so that the stopper pin 50 can move up and down.

In consideration of the outer diameter of the stud 46 to be used, the gripping cylinder 6 is arranged so that at least a gap larger than this outer diameter is formed between the chuck claws 48.
6 is driven to sufficiently separate the chuck claws 48.
The stud 46 is inserted between the chuck claws 48 from below, and the stopper pin 50 is pushed up by the upper end of the stud 46 against the biasing force of the compression spring 94.

Here, the chuck claw 4 according to the present embodiment.
The shape and the interval of 8 can hold the stud 46S having the smallest diameter (see FIG. 4B) in the closest state, and the stud 46L having the largest diameter in the most spaced state (see FIG. 4B).
(See (A)) Since the gap is set to be wider than the outer diameter (see (A)), it corresponds to all of the stud S having the smallest diameter, the stud L having the largest diameter, and the stud 46 having an outer diameter between these. be able to.

When the stud 46 is inserted to a predetermined position,
The gripping cylinder 66 is driven to grip the stud 46.

Next, the air cylinder 18 is driven to lower the gun body 14. As shown in FIG. 7 (A), one end 84A of the lever 84 is separated from the dog 96.
Receives the urging force of the lever urging spring 92 and becomes the bite position. The hole edge of the insertion hole 88 of the lever 84 is the stopper pin 50.
Since it bites into the outer periphery of the stopper pin 50, the stopper pin 50 is fixed and its vertical movement is blocked.

As described above, the stud 4 on the gun body 14
Since the mounting of 6 is completed, the stud 46 is pressed against the work (not shown) with an appropriate force. The pressing force at this time acts from the pressure spring 76, but the stored force of the pressure spring 76 can be adjusted by the pressure cylinder 80. Therefore, the stud 46 can be pressed with appropriate acceleration and pressing force according to the diameter of the stud 46, the type of the work, the relationship between the work and the stud 46, and the like.

In this state, power is turned on and the work and the stud 46 are
An arc is generated between the stud 46 and the stud 46, and the stud 46 is appropriately melted and pressed against the work by welding.

When the welding is completed, the gripping cylinder 66
Is driven to separate the chuck claws 48. The chuck claws 48 are so shaped and spaced that they are wider than the outer diameter of the largest diameter stud 46L (see FIG. 5B) in the most spaced state. Even in this case, the grip by the chuck claw 48 can be reliably released.

Further, the air cylinder 18 is driven to raise the gun body 14. At this time, as described above, since the gripping of the stud 46 by the chuck claw 48 is released, the work is prevented from being lifted when the gun body 14 is lifted up even without a conventional member such as a work pressing member. To be done. Further, since one end of the lever 84 is pushed down by the dog to bring the lever 84 into the non-bite position, the stopper pin 50 is released from the fixed state and can move up and down.

As can be seen from the above description, in the stud welding gun 12 of this embodiment, the chuck claw 48 is configured to be expandable / contractible between the maximum diameter stud 46S and the maximum diameter stud 46L. A gripping force is applied to the chuck claw 48 by the gripping cylinder 66 to grip the stud 46. Therefore,
Corresponding to all of the minimum diameter stud 46S, the maximum diameter stud 46L, and the stud 46 having an outer diameter between these, it is possible to reliably grip with a constant gripping force,
It enables stable welding. Since the stud 46 is not pushed into or pulled out from the chuck claw 48 as in the conventional case, the chuck claw 48 is not worn and the gripping force with respect to the stud 46 can be maintained for a long time.

Moreover, the stud welding gun 1 of the present embodiment
2, the stopper pin 50 is movable in the vertical direction (longitudinal direction) with respect to the chuck claw 48, and the gun body 14
The stopper pin 50 is fixed or released by the vertical movement of the. Therefore, even with studs 46 having different lengths, it is not necessary to adjust or replace the stopper pin 50, and one stopper pin 50 can be used.
Moreover, the stopper pin 50 can be fixed and released by a simple operation of moving the gun body 14 up and down.

As can be seen from the above description, the stud welding gun 12 of the present embodiment includes at least the chuck claw 48, the expansion / contraction device (grasping cylinder 66 and link mechanism 56), and the fixing means (lever 84). The gun body 14 is configured. Therefore, it is possible to integrally move these by moving the gun body 14 up and down.
Work can be done efficiently.

The fixing means of the present invention is not limited to the one having the lever 84 described above. That is, at least by the chuck claw 48, the stud 46 is
It suffices if the stopper pin 50 can be fixed and released in the longitudinal direction while being gripped.

The gripping member of the present invention is not limited to the chuck claw 48 described above. That is, the stud 46 that is supposed to be used in the stud welding gun 12
It suffices that the stud 46 can be gripped by moving between the reduced position and the enlarged position in accordance with.

[0054]

Since the present invention has the above-mentioned structure, the stud can be surely gripped, the studs having different diameters can be gripped, and even if the studs have different lengths, the stopper pin can be used. It can be accommodated without having to adjust or replace the length.

[Brief description of drawings]

FIG. 1 shows a stud welding gun according to an embodiment of the present invention, (A) is a front view and (B) is a side view.

2A is an enlarged side view showing a gun body of a stud welding gun according to an embodiment of the present invention, FIG. 2B is an enlarged front view showing the gun body, and FIG. It is explanatory drawing which looked at a chuck claw and a stopper pin from the lower part.

FIG. 3 is a view showing a gun body of a stud welding gun according to an embodiment of the present invention in a state in which a chuck claw is most reduced,
Is a front view, and (B) is an explanatory view of the chuck claw viewed from below.

FIG. 4 is a view showing a gun body of a stud welding gun according to an embodiment of the present invention in a state where a chuck claw holds a stud having a minimum diameter, (A) is a front view, and (B) is a view of the chuck claw viewed from below. It is a figure.

FIG. 5 shows a gun body of a stud welding gun according to an embodiment of the present invention in a state where a chuck claw holds a stud having a maximum diameter, (A) is a front view, and (B) is a view of the chuck claw viewed from below. It is a figure.

FIG. 6 is an explanatory view showing a link mechanism which constitutes a gun main body of the stud welding gun according to the embodiment of the present invention and the vicinity thereof.

FIG. 7 is an explanatory view showing the action of the stopper pin of the stud welding gun according to the embodiment of the present invention, (A) shows a state in which the stopper pin is fixed, and (B) shows a state in which the stopper pin is movable. Shown respectively.

FIG. 8 is a cross-sectional view showing a conventional stud welding gun.

[Explanation of symbols]

12 Stud welding gun 14 gun body 16 1st cylinder plate (holding member) 46 Stud 48 Chuck claw (holding member) 50 Stopper pin 56 Link mechanism (expansion / contraction device) 66 Cylinder for gripping (expansion / contraction device) 84 Lever (fixing member, fixing means) 88 insertion hole

Claims (4)

[Claims] 1. A gripping member capable of expanding and contracting between a contracted position for radially gripping an assumed minimum diameter stud and an expanded position for opening an assumed maximum diameter stud, and the gripping member. An expansion / contraction device that moves in the expansion / contraction direction and exerts a gripping force, a stopper pin that is movably arranged in the gripping member in the same direction as the longitudinal direction of the stud, and a gripping state in which the stud is gripped by the gripping member. A stud welding gun, comprising: fixing means for immobilizing the stopper pin in the member in the longitudinal direction thereof. 2. The expansion / contraction device has a gripping cylinder that exerts a predetermined gripping force in the same direction as the longitudinal direction of the stud, and a link mechanism that converts the gripping force of the gripping cylinder into the expansion / contraction direction of the gripping member. The stud welding gun according to claim 1, further comprising: 3. A gun main body including the gripping member, the expansion / contraction device, and the fixing means, and a holding member for holding the gun main body movably in the longitudinal direction of the stud. The stud welding gun according to claim 1 or 2. 4. The fixing means has an insertion hole through which the stopper pin is inserted, and a biting position where the hole edge of the insertion hole bites into the stopper pin when the gun body moves with respect to the holding member. The stud welding gun according to claim 3, further comprising: a fixing member that moves between a non-bite position that eliminates the bite state and a fixing member.