JP4799773B2 - Stud welding gun - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a stud welding gun used for holding a stud and pressing it against a work piece for welding.
[0002]
[Prior art]
FIG. 8 shows an example of a conventional stud welding gun 112 in a sectional view.
[0003]
The stud welding gun 112 includes a chuck 116 having an inner diameter that matches the outer diameter of the stud 114 and a stopper pin 118 that has a length that matches the length of the stud 114. A pressing force from the pressure spring 120 acts on the stud 114 while being held by the chuck 116.
[0004]
Further, the stud welding gun 112 has a work retainer 122 whose tip contacts the work during welding. Since the tip of the work presser 122 is brought into contact with the work to press the stud welding gun 112 and the compression spring 124 is compressed and welded, when the stud welding gun 112 is separated from the work after welding, the spring of the compression spring 124 is pressed. The force acts on the workpiece via the workpiece holder 122, and the workpiece is prevented from being lifted.
[0005]
However, since the stud 114 is pushed in when the stud 114 is attached to the chuck 116, depending on the relationship between the stud 114 and the chuck 116, the holding force may become unstable and the welding strength may vary. Further, when the pushing of the stud 114 with respect to the chuck 116 and the drawing after welding are repeated, the chuck 116 may be worn and the holding force of the chuck 116 may be reduced.
[0006]
In addition, since the chuck 116 has a dedicated shape that matches the specific stud 114, for example, when the outer diameter of the stud 114 changes, the chuck 116 needs to be changed. Further, since the chuck 116 still holds the stud 114 after welding, the work holder 112 and the compression spring 124 are required to prevent the work from being lifted.
[0007]
Furthermore, if the length of the stud 114 changes, it is necessary to adjust or replace the length of the stopper pin 118.
[0008]
[Problems to be solved by the invention]
In consideration of such a fact, the present invention can reliably hold the stud, can also handle studs of different diameters, and adjusts the length of the stopper pin even for studs of different lengths. It is an object to obtain a stud welding gun that can be handled without having to be replaced.
[0009]
[Means for Solving the Problems]
In the invention according to claim 1, a gripping member that can be expanded and contracted between a contracted position that grips an assumed minimum diameter stud in a radial direction and an expanded position that opens an assumed maximum diameter stud; An expansion / contraction device that moves the gripping member in the expansion / contraction direction and applies a gripping force, a stopper pin that is movable in the same direction as the longitudinal direction of the stud in the gripping member, and the stud is gripped by the gripping member And a fixing means for making the stopper pin in the gripping member immovable in the longitudinal direction thereof, and including the gripping member, the expansion / contraction device, and the fixing means. holding member for movably holding the longitudinal direction of the stud, further comprising a said fixing means, an insertion hole which the stopper pin is inserted is formed, It is configured to include a fixing member that moves between a biting position where the hole edge of the insertion hole bites into the stopper pin and a non-biting position that cancels the biting state by moving the gun body with respect to the holding member. Features.
[0010]
In other words, the gripping member is expanded and contracted between the contracted position and the expanded position by the expansion / contraction device, and in the contracted position, even the stud having the smallest diameter is gripped in the radial direction by receiving the gripping force from the expansion / contraction device. Can do. Therefore, by inserting the stud in a state where the gripping member is appropriately enlarged from the reduced position and applying a gripping force by the expansion / contraction device, the stud of the maximum diameter or the intermediate between the stud of the minimum diameter and the stud of the maximum diameter Even a stud with a diameter of can be reliably gripped. In addition, since the gripping member is opened even if it is the stud with the maximum diameter assumed in the enlarged position, even when gripping the stud with the maximum diameter, there is no need to push the stud into the gripping member, and the stud is pulled out after welding. There is no need. For this reason, wear of the gripping member is prevented, and a decrease in gripping force can be prevented. In addition, by releasing the stud by the gripping member after welding, it is possible to prevent the workpiece from being lifted when the stud welding gun is separated from the workpiece, so that the conventional workpiece pressing or the like is not required. In addition , the gun body is configured to include a gripping member, an expansion / contraction device, and a fixing means, and has a holding member that holds the gun body so as to be movable in the longitudinal direction of the stud. By moving in the longitudinal direction, the gripping member, the expansion / contraction device and the fixing means can be moved integrally.
[0011]
Furthermore, in this stud welding gun, the stopper pin can be moved in the same direction as the longitudinal direction of the stud, and when the stud is gripped by the gripping member, the stopper pin cannot be moved in the longitudinal direction by the fixing means. The Therefore, even if the studs have different lengths, the stopper pins can be moved according to the position without any adjustment or replacement.
This fixing means is formed with an insertion hole through which the stopper pin is inserted, and the movement of the gun body with respect to the holding member causes a biting position where the hole edge of the insertion hole bites into the stopper pin, and a non-biting position where the biting state is eliminated. It is comprised including the fixing member which moves.
Therefore, in a state where the gripping member holds the stud, the fixing member becomes the biting position by the movement of the gun body with respect to the holding member. At the biting position, since the hole edge of the insertion hole formed in the fixing member bites into the stopper pin, the stopper pin can be fixed and cannot move in the longitudinal direction. Further, when the fixing member is brought into the non-breaking position by the movement of the gun body with respect to the holding member, the biting state is canceled, so that the stopper pin can be moved in the longitudinal direction.
In this way, the stopper pin can be fixed and released easily only by moving the gun body.
[0012]
According to a second aspect of the present invention, in the first aspect of the present invention, the expansion / contraction device includes a gripping cylinder that exhibits a predetermined gripping force in the same direction as the longitudinal direction of the stud, and a gripping of the gripping cylinder. And a link mechanism that converts a force into the expansion / contraction direction of the gripping member.
[0013]
Accordingly, the gripping force of the gripping cylinder is converted by the link mechanism into the direction of expansion / contraction of the gripping member, so that the gripping member can be expanded and contracted 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 can be miniaturized as a stud welding gun. .
[0019]
DETAILED DESCRIPTION OF THE INVENTION
1A and 1B show the overall configuration of a stud welding gun 12 according to an embodiment of the present invention. 2A and 2B show the gun body 14 in an enlarged manner. Hereinafter, for convenience of illustration, the longitudinal direction of a stopper pin 50 and a stud 46, which will be described later, is set up and down, but the direction of the stud welding gun 12 is not limited to this.
[0020]
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 attached. 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 connected to the gun body 14 via the second cylinder plate 20, and the gun body 14 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). it can.
[0021]
An absorber 24 is attached to the first cylinder plate 16 via an absorber bracket 22. The lowering of the gun body 14 is limited to a certain range when the stopper block 26 attached to the gun body 14 hits the absorber 24, and the lower end of the gun body 14 is positioned.
[0022]
As shown in FIGS. 2A and 2B, the gun body 14 is formed of a substantially “U” shape composed of a cylinder plate 30, a horizontal base 32, and a vertical base 34 that connect the cylinder plate 30 and the parallel base 32. The base member 28 has a shape. A base insulating plate 40 is adhered to the vertical base 34, and the base member 28 is insulated.
[0023]
A pair of horizontal movement guides 36 are attached to the upper surface of the horizontal base 32. The horizontal movement guides 36 move in the horizontal direction (the direction of arrow B in FIG. 2B and the opposite direction) along the guide rails 38, and approach or separate from each other.
[0024]
A pair of vertical movement guides 44 are arranged between the horizontal movement guides 36 via a slide bracket 42, and the lower part of the vertical movement guides 44 passes through a hole formed in the horizontal base 32. Is extended downward. The vertical movement guide 44 is held by a slide bracket 42 so as to be movable in the vertical direction.
[0025]
Between the vertical movement guides 44, a pair of chuck claws 48 for holding the studs 46 (see FIGS. 4, 5, and 7) are arranged and fixed to the corresponding vertical movement guides 44, respectively. Therefore, when the horizontal movement guide 36 approaches or separates, the vertical movement guide 44 also approaches or separates, and accordingly, the chuck claw 48 also approaches or separates.
[0026]
The shape and interval of the chuck claw 48 are such that the smallest diameter stud 46S (see FIG. 4B) that is expected to be used in the stud welding gun 12 can be gripped in the closest state. The stud 46S is narrower than the outer diameter of the stud 46S, and in the most separated state, the stud 46L is separated from the stud 46L (see FIG. 5B) having the largest diameter assumed to be used in the stud welding gun 12 (that is, the largest diameter). The stud 46L is set to have a wider interval than the outer diameter of the stud 46L.
[0027]
A stopper pin 50 is disposed between the chuck claws 48. As shown in FIG. 3, the stopper pin 50 does not affect the gripping of the stud 46 by inadvertently contacting or interfering with the chuck claw 48 even when the chuck claw 48 is closest. It has a predetermined diameter. Further, a stopper pin guide 52 is attached to the horizontal base 32, and the stopper pin 50 is held so as to be movable in the vertical direction (that is, the longitudinal direction) while preventing the stopper pin 50 from shaking in the lateral direction. A set collar 54 is attached to a substantially middle portion in the vertical direction of the stopper pin 50 so that the stopper pin 50 is partially enlarged in diameter. The downward movement of the stopper pin 50 causes the set collar 54 to move to the stopper pin 50. By hitting the guide 52, it is limited to a certain range.
[0028]
A link mechanism 56 is disposed in the base member 28. As shown in detail in FIG. 6, the link mechanism 56 is arranged along the vertical direction and is movable in the vertical direction. The upper end of the link mechanism 56 is connected to the lower end of the clamp shaft 58 by a hinge pin 62. And a pair of expansion / contraction links 60. The lower end of the expansion / contraction link 60 extends in a direction away from each other and is connected to a knuckle 64 by a hinge pin 62 so as to approach or separate by the vertical movement of the clamp shaft 58. The knuckle 64 is fixed to the horizontal movement guide 36. Accordingly, when the clamp shaft 58 moves up and down, the horizontal movement guide 36 approaches or separates.
[0029]
A gripping cylinder 66 is attached to the upper surface of the cylinder plate 30 and connected to the clamp shaft 58 via a joint 68. Accordingly, by driving the gripping cylinder 66, the clamp shaft 58 can be moved up and down, and the horizontal movement guide 36, the vertical movement guide 44, and the chuck claw 48 can be approached or separated.
[0030]
The clamp shaft 58 is held by a linear bush 70 fixed to the vertical base 34, and moves up and down smoothly without wobbling in the lateral direction. The link mechanism 56 and the gripping cylinder 66 constitute the expansion / contraction device of the present invention.
[0031]
In order to expand or contract the horizontal movement guide 36, vertical movement guide 44, and chuck claw 48 close to or away from each other, the gripping cylinder 66 is disposed in the same direction as the expansion / contraction direction (that is, the horizontal direction). However, in the stud welding gun 12 of this 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 protrude in the expansion / contraction direction, and stud welding is performed. The size of the gun 12 is reduced.
[0032]
Further, in the base member 28, as shown in FIGS. 2A and 2B, a pressurizing unit 72 is disposed between the cylinder plate 30 and the slide bracket. The pressure unit 72 includes a substantially box-shaped spring receiver 74 that houses the upper portion of the stopper pin 50, and a pressure spring 76 disposed 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 also acts on the stopper pin 50 via the pressing piece 102 disposed in the spring receiver 74 and a lever 84 described later.
[0033]
A pressure cylinder 80 is attached to the upper surface of the cylinder plate 30, and a piston 82 of the pressure cylinder 80 passes through the cylinder plate 30 and is connected to the upper end of the pressure spring 76. By adjusting the pressure applied to the pressure cylinder 80 (the position of the piston 82), the stored force of the pressure spring 76 can be adjusted. At the time of welding, moderate acceleration and pressing force act on the stud due to the stored energy on the pressure spring 76.
[0034]
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 certain length, and one end 84 </ b> A side thereof is a guide hole 86 formed in the spring receiver 74. Protrudes from the outside. An insertion hole 88 is formed on the other end 84 </ b> B side of the lever 84, and the stopper pin 50 is inserted into the insertion hole 88. The inner diameter of the insertion hole 88 is slightly larger than the outer diameter of the stopper pin 50. As shown in FIG. 7B, the lever 84 is orthogonal to the stopper pin 50 (non-breaking position). The hole edge of the insertion hole 88 does not contact the outer periphery of the stopper pin 50. On the other hand, as shown in FIG. 7A, when the lever 84 is inclined at a certain angle or more (biting position), the hole edge of the insertion hole 88 comes into contact with the outer periphery of the stopper pin 50, and the stopper The movement of the pin 50 in the longitudinal direction can be prevented. The inclination range (inclination angle) of the lever 84 is limited to a certain range as the one end 84 </ b> A side moves in the guide hole 86.
[0035]
A spring case 90 is disposed at the bottom of the spring receiver 74, and a lever biasing spring 92 is accommodated therein. The upper end of the lever biasing spring 92 is in contact with the substantially middle portion of the lever 84 from below, and the lever 84 is biased from the non-biting position to the biting position.
[0036]
As shown in FIGS. 2 to 5, a compression spring 94 is disposed between the spring case 90 and the set collar 54. The compression spring 94 is formed to have a smaller spring force than the lever biasing spring 92 and biases the set collar 54 and the stopper pin 50 downward with respect to the spring receiver 74.
[0037]
As shown in FIGS. 1A and 1B, a dog 96 is fixed to the first cylinder plate 16. When the gun body 14 is lowered, the dog 96 does not come into contact with the lever 84 as shown in FIG. 7A, but when the gun body 14 is raised, as shown in FIG. 7B. The lever 84 is fixed at a predetermined position so that one end 84A of the lever 84 contacts the dog 96 and is pushed downward. Accordingly, the lever 84 is pushed down by the dog 96 against the biasing force of the lever biasing spring 92 when the gun body 14 is raised, and is in the non-breaking position, so that the stopper pin 50 moves up and down. It becomes possible. On the other hand, when the gun body 14 is lowered and the dog 96 is separated from one end of the lever 84, the lever 84 is inclined by the urging force of the lever urging spring 92 to enter the biting position. Be blocked.
[0038]
A power cable 98 is connected to the gun body 14, and a predetermined electric power can be supplied by energizing during welding to generate an arc between the stud 46 and the workpiece. 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.
[0039]
Next, the operation of the stud welding gun 12 of this embodiment will be described.
[0040]
When welding using the stud welding gun 12, first, the gun body 14 is raised. In this state, as shown in FIG. 7B, since one end of the lever 84 is pushed by the dog 96 and the lever 84 is in the non-breaking position, the stopper pin 50 can move up and down.
[0041]
Then, considering the outer diameter of the stud 46 to be used, the chucking claw 48 is sufficiently separated by driving the gripping cylinder 66 so that at least a gap larger than the outer diameter is formed between the chuck claw 48. Let The stud 46 is inserted between the chuck claws 48 from below, and the stopper pin 50 is pushed up at the upper end of the stud 46 against the urging force of the compression spring 94.
[0042]
Here, the shape and interval of the chuck claw 48 according to the present embodiment can grip the smallest diameter stud 46S (see FIG. 4B) in the closest state, and the maximum diameter in the most separated state. The stud 46L (see FIG. 4A) is set to have a larger interval than the outer diameter of the stud 46L (see FIG. 4A), so that the stud S having the smallest diameter, the stud L having the largest diameter, and a stud having an intermediate outer diameter therebetween. All 46 can be accommodated.
[0043]
When the stud 46 is inserted to a predetermined position, the gripping cylinder 66 is driven to grip the stud 46.
[0044]
Next, the air cylinder 18 is driven to lower the gun body 14. As shown in FIG. 7A, since the one end 84A of the lever 84 is separated from the dog 96, the lever 84 receives the urging force of the lever urging spring 92 and enters the biting position. Since the hole edge of the insertion hole 88 of the lever 84 bites into the outer periphery of the stopper pin 50, the stopper pin 50 is fixed and its vertical movement is prevented.
[0045]
As described above, the mounting of the stud 46 to the gun body 14 is completed, and the stud 46 is pressed against the workpiece (not shown) with an appropriate force. The pressing force at this time acts from the pressurizing spring 76, but the stored force of the pressurizing spring 76 can be adjusted by the pressurizing cylinder 80. Therefore, it can be pressed with an appropriate acceleration and pressing force according to the diameter of the stud 46, the type of the workpiece, the relationship between the workpiece and the stud 46, and the like.
[0046]
In this state, power is supplied, an arc is generated between the workpiece and the stud 46, and the stud 46 is pressed against the workpiece and welded in a state where the stud 46 is appropriately melted.
[0047]
When the welding is completed, the gripping cylinder 66 is driven to separate the chuck claw 48. The shape and interval of the chuck claw 48 is set so that the interval is wider than the outer diameter of the maximum diameter stud 46L (see FIG. 5B) in the most distant state. Even so, the gripping by the chuck claw 48 can be reliably released.
[0048]
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, it is possible to prevent the workpiece from being lifted when the gun body 14 is lifted even without a conventional member such as a workpiece presser. Is done. Further, since one end of the lever 84 is pushed down by the dog and the lever 84 is brought into the non-breaking position, the stopper pin 50 is released from being fixed and can be moved up and down.
[0049]
As can be seen from the above description, in the stud welding gun 12 of the present embodiment, the chuck claw 48 is configured to be able to expand and contract between the respective diameters of the maximum diameter stud 46S and the maximum diameter stud 46L, and the gripping cylinder. The stud 46 is gripped by applying a gripping force to the chuck claw 48 by 66. Accordingly, the stud 46S having the minimum diameter, the stud 46L having the maximum diameter, and the stud 46 having an intermediate outer diameter can be securely gripped with a constant gripping force, and can be stably welded. It becomes possible. Since the stud 46 is not pushed into and pulled out from the chuck claw 48 as in the prior art, the chuck claw 48 is not worn and the gripping force on the stud 46 can be maintained for a long period of time.
[0050]
Moreover, in the stud welding gun 12 of this embodiment, the stopper pin 50 can be moved in the vertical direction (longitudinal direction) with respect to the chuck claw 48, and the stopper pin 50 is fixed or released by the vertical movement of the gun body 14. Yes. Therefore, it is not necessary to adjust or replace the stopper pin 50 even with the studs 46 having different lengths, and it can be handled with one stopper pin 50 and can be operated simply by moving the gun body 14 up and down. Thus, the stopper pin 50 can be fixed and released.
[0051]
Further, 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 (the gripping cylinder 66 and the link mechanism 56), and the fixing means (the lever 84). Is configured. Accordingly, the gun body 14 can be moved up and down by the operation of moving the gun body 14 up and down, and the work can be performed efficiently.
[0052]
The fixing means of the present invention is not limited to the structure having the lever 84 described above. That is, it is sufficient that the stopper pin 50 can be fixed and released in the longitudinal direction at least in a state where the stud 46 is gripped by the chuck claw 48.
[0053]
Further, the gripping member of the present invention is not limited to the chuck claw 48 described above. That is, it is only necessary that the stud 46 can be gripped by moving between the reduced position and the enlarged position corresponding to the stud 46 assumed to be used in the stud welding gun 12.
[0054]
【The invention's effect】
Since the present invention is configured as described above, the stud can be securely gripped, can be gripped corresponding to studs of different diameters, and the length of the stopper pin can be adjusted or adjusted even for studs of different lengths. It is possible to respond without having to exchange.
[Brief description of the drawings]
FIG. 1 shows a stud welding gun according to an embodiment of the present invention, where (A) is a front view and (B) is a side view.
2A is a side view showing an enlarged gun body of a stud welding gun according to an embodiment of the present invention, FIG. 2B is a front view showing an enlarged gun body, and FIG. It is explanatory drawing which looked at the chuck claw and the stopper pin from the lower part.
3A and 3B show a gun main body of a stud welding gun according to an embodiment of the present invention in a state in which a chuck claw is most contracted, and FIG. 3A is a front view, and FIG. 3B is an explanatory view of the chuck claw viewed from below.
4A and 4B show a gun main 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, FIG. 4A is a front view, and FIG. 4B is an explanation of the chuck claw viewed from below. FIG.
5A and 5B show a gun main body of a stud welding gun according to an embodiment of the present invention in a state in which a chuck claw holds a stud having a maximum diameter, FIG. 5A is a front view, and FIG. 5B is an explanation of the chuck claw viewed from below. FIG.
FIG. 6 is an explanatory view showing a link mechanism constituting a gun body of a stud welding gun according to an embodiment of the present invention and its vicinity.
7A and 7B are explanatory views showing the action of the stopper pin of the stud welding gun according to the embodiment of the present invention, in which FIG. 7A shows a state in which the stopper pin is fixed, and FIG. 7B shows a state in which the stopper pin is movable. Each is shown.
FIG. 8 is a cross-sectional view showing a conventional stud welding gun.
[Explanation of symbols]
12 Stud welding gun 14 Gun body 16 First cylinder plate (holding member)
46 Stud 48 Chuck claw (gripping member)
50 Stopper pin 56 Link mechanism (expansion / contraction device)
66 Gripping cylinder (expansion / contraction device)
84 lever (fixing member, fixing means)
88 Insertion hole

Claims (2)

A gripping member that can be expanded and contracted between a contracted position that grips the assumed minimum diameter stud in the radial direction and an expanded position that opens the assumed maximum diameter stud;
An expansion / contraction device that moves the gripping member in the expansion / contraction direction and applies a gripping force;
A stopper pin disposed so as to be movable in the same direction as the longitudinal direction of the stud in the gripping member;
Fixing means for making the stopper pin in the gripping member immovable in the longitudinal direction in a state where the stud is gripped by the gripping member;
And a gun body including the gripping member, the expansion / contraction device, and the fixing means,
A holding member that holds the gun body movably in the longitudinal direction of the stud;
The fixing means is
An insertion hole through which the stopper pin is inserted is formed, and a biting position where a hole edge of the insertion hole bites into the stopper pin by movement of the gun body with respect to the holding member, and a non-biting position where the biting state is eliminated Moving fixed member,
A stud welding gun comprising: The expansion / contraction device is
A gripping cylinder that exerts a predetermined gripping force in the same direction as the longitudinal direction of the stud;
A link mechanism for converting the gripping force of the gripping cylinder into the expansion / contraction direction of the gripping member;
The stud welding gun according to claim 1, comprising:

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