JPH10109183A - Welding device for projection nut and welding method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely uniformalize the relative position of a nut to a guide pin, and to correctly set a welding position by installing the guide pin advancing into a thread hole of the nut in an advanceable and retreatable state to and from an electrode. SOLUTION: When the guide pin 13 is moved upward by the operation of an air cylinder 30, a small diameter part 15 is passed through a notch groove 24, and passed through the inside of the thread hole 26 of the nut, and it becomes a state shown by two-dot chain lines. Next, when a supply rod 20 is retreated, since the guide pin 13 has pierced through the thread hole 26, a magnet 28 is forcedly removed from a lateral side surface of the nut 25. Then, the tip part of the thread hole 26 is caught by an inclined part 16, and the nut is aligned. After that, when a movable electrode 19 is moved ahead, the small diameter part 15 enters a receiving hole 32, and it adheres closely to the upper surface of the end face nut 25 of the movable electrode. When it is moved downward further, the guide pin 13 is forcedly pushed downward, and the nut 25 is pushed against a plate part 17, and projecting welding is completed through the order of energizing and welding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method in which a projection rod is moved forward and backward to align a projection nut with a guide pin of a fixed electrode, and then welds the same.

[0002]

2. Description of the Related Art In a type in which a supply rod is advanced from a direction substantially perpendicular to the axis of an electrode and a projection nut held on the supply rod is supplied to a guide pin of the electrode, the projection nut is located directly above the guide pin. And then release the projection nut,
A device that drops onto a guide pin is known. One example is JP-A-51-109247. The technique disclosed herein is as shown in FIG. 10, in which a hollow supply rod 1 is installed so as to advance and retreat in a substantially horizontal direction, and a box-shaped component housing portion 2 is formed at a tip end thereof. Since the lower side of the component housing 2 is open, a sliding type opening / closing plate 3 is provided, and the opening / closing slide of the sliding type opening / closing plate 3 is performed by an advance / retreat rod 4. A steel plate component 6 is placed on the electrode 5, and a guide pin 7 of the electrode 5 projects upward while penetrating the steel plate component 6. The part is a projection nut indicated by reference numeral 8. The other electrode paired with the electrode 5 is not shown.

[0003] Fig. 10 shows that the supply rod 1 is advanced and the projection nut 8 is connected to the steel plate part 6 as shown by the solid line.
Operation is described below, showing the state as supplied above. When the supply rod 1 is advanced from a direction substantially perpendicular to the electrode 5 and the nut 8 shown by a two-dot chain line is coaxial with the guide pin 7, the supply rod 1 stops, and then the advance / retreat rod 4 is retracted, and When the lower side of the housing portion 2 is opened, the nut 8 falls and the guide pin 7 is fitted into the screw hole as shown by the solid line, and the nut supply is completed. After that, the other electrode advances to complete the projection welding.

[0004]

In the prior art as described above, since the projection nut 8 is dropped on the guide pin 7, if the nut 8 is tilted during the transitional period of falling, It may be flipped by the tip of the guide pin 7 and may not be placed correctly as shown by the solid line. Such an abnormal phenomenon also occurs when the supply rod 1 does not stop at a correct position due to the relative positional relationship with the guide pin 7. Further, there is a problem that the projection nut is displaced in the rotation direction with respect to the guide pin 7 and is not welded to the steel plate part 6 in a uniform direction.

[0005]

Means for Solving the Problems and Their Functions The present invention has been provided to solve the above-mentioned problems.
According to the first aspect of the present invention, the forward and backward directions of the supply rod are set so as to be substantially orthogonal to the axis of the electrode, and the distal end of the supply rod is formed with a recess for holding a projection nut that is opened to the distal end side, The projection nut holding means is installed in this recess, and the guide pin which enters the screw hole of the projection nut stopped at a position substantially coaxial with the electrode is installed so as to be able to advance and retreat to the electrode. When the projection nut is stopped at a position substantially coaxial with the guide pin, the guide pin comes out and enters the screw hole of the nut, and then, when the supply rod is retracted, the nut is held by the holding means. And remains on the guide pins, after which the other electrode is activated to complete the projection welding. According to a second aspect of the present invention, in the first aspect,
A notch groove for passing a guide pin is formed in the bottom plate of the recess so as to be open to the tip side of the supply rod. When the guide pin advances, the nut screw is passed through the notch groove. When the supply rod retreats in this hole and then in this state, the guide pin waits for the other electrode to advance while holding the nut through the notch groove. To complete the projection welding. According to a third aspect of the present invention, in the second aspect,
The guide pin is composed of a large diameter part and a small diameter part, and an inclined part is provided at the boundary between these two diameter parts, the small diameter part penetrates the screw hole of the projection nut, and the inclined part engages the end of the screw hole The projection nut is centered by the engagement of the inclined portion. According to a fourth aspect of the present invention, in the third aspect,
A receiving hole for receiving the small-diameter portion is provided in the other electrode, so that the small-diameter portion does not interfere with the other electrode when the two electrodes approach each other. According to a fifth aspect of the present invention, the forward / backward direction of the supply rod is set to a direction substantially orthogonal to the axis of the electrode, and a concave portion for holding a projection nut opened to the distal end side is formed at the distal end of the supply rod, The projection nut holding means is installed in this recess, and after the projection nut is stopped at a position substantially coaxial with the electrode, the guide pin of the electrode comes out and enters the screw hole of the projection nut. In this state, the supply rod is retracted, the projection nut is left engaged with the guide pin, and then the electrode is advanced to complete the welding. The guide pin performs the reciprocating movement in the same way, and the combination of both movements ensures that the nut is supplied in a fixed position and that the welding is secure. It is. According to a sixth aspect of the present invention, in the first aspect, the guide pin is provided with suction means for preventing a displacement of the projection nut, and when the projection nut is engaged with the guide pin, the projection is Since the nut is sucked by the guide pin, even if the projection nut is shifted in the rotational direction with respect to the guide pin due to some reason such as vibration of the welding device, the position is not easily shifted.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. First, the embodiment shown in FIGS. 1 to 3 will be described. A cylindrical base 10 is fixed on a stationary member 9 and a fixed electrode 11 is firmly connected thereto. A guide hole 12 is formed in the center of the fixed electrode 11 in a state where it penetrates, and a guide pin 13 is slidably inserted therein. Guide pin 1
3 is composed of a large diameter portion 14 and a small diameter portion 15;
An inclined portion 16 is provided at the boundary between 4 and 15. A steel plate part 17 is placed on the fixed electrode 11, and the steel plate part 17 is fixed by a positioning means (not shown) so that the positioning hole 18 formed in the steel plate part 17 and the guide hole 12 match as shown. Have been.

[0007] A movable electrode 19 is installed so as to be able to advance and retreat in pairs with the fixed electrode 11. Since the movable electrode 19 advances and retreats using a normal air cylinder, the description is omitted here. A supply rod 20 is installed so as to advance and retreat in a direction substantially perpendicular to the axis of the electrode, and a concave portion 21 for holding a component opened toward the distal end is formed at the distal end thereof, and the distal end is opened. For this purpose, an opening 22 is provided. In the case shown, the concave portion 21 is opened upward.
The bottom plate 23 of the recess 21 has a notch groove 24 opened to the front end side.
Is formed. The component is a projection nut 25 made of iron. Reference numeral 26 denotes a screw hole, and reference numeral 27 denotes a projection for welding. The projection nut 25 has a square shape, and its dimensions are 10 mm in length and width and 5 mm in thickness. Since the parts have such a shape, the concave portion 21 is also in a box shape conforming thereto. Nut 25 in recess 21
May fall from the recess due to vibration or stoppage of the supply rod 20,
Since the position must not be displaced in the concave portion 21, a holding means is provided in the concave portion 21. As the holding means, various methods such as lightly pressing the side surface or the upper surface of the nut with a leaf spring or suctioning the nut with vacuum of air can be applied. Here, an example of a magnet (permanent magnet) is shown. That is, the magnet 28 is
It is a state embedded in the inside.

The guide pin 13 advances and retreats in the guide hole 12. For this purpose, an air cylinder 30 is disposed in the base 10, and its piston rod 31 is connected to the guide pin 13. The movable electrode 19 has a small diameter portion 15.
A receiving hole 32 for receiving the small diameter portion 15 is formed.
However, even if the movable electrode 19 advances to a position penetrating the screw hole 26 as shown by the two-dot chain line in FIG. 1, the small diameter portion 15 does not interfere with the movable electrode 19.

The means for moving the supply rod 20 forward and backward can be easily moved forward and backward by using a normal air cylinder. Therefore, as shown in FIG. 1, the air cylinder 33 is fixed to the stationary member 9 by a two-dot chain line on the right side, and the piston rod 34 is connected to the supply rod 20.

As a method of supplying the nut 25 to the concave portion 21, there is a method in which the nut is held and supplied by a chuck, or a method in which the nut is held and supplied to another supply rod. The scheme is illustrated. That is, a supply hose (not shown) extends from the parts feeder, and a metal inclined shooter 35 is connected to the supply hose. A stopper wall 36 is provided at the end of the inclined shooter, and an opening 37 is opened so that the nut 25 stopped here drops. The opening 37 is located just above the concave portion 21, and the nut 25 that has descended from the inclined shooter 35 falls into the concave portion 21 as shown by a two-dot chain line, and at the same time, the nut 25 is attracted to the magnet 28. It is held in the recess 21.

The operation of the structure of the embodiment described above will be described. FIG. 1 shows that the supply rod 20 advances and stops,
This shows a state in which the screw hole 26 of the nut is substantially coaxial with the positioning hole 18 and the guide hole 12. Here, when the guide pin 13 is raised by the operation of the air cylinder 30, the small-diameter portion 15 passes through the notch groove 24 and the screw hole 26 of the nut is formed.
Through the inside, a state as shown by a two-dot chain line is obtained. Next, when the supply rod 20 is retracted, the magnet 28 is forcibly separated from the lateral side surface of the nut 25 because the guide pin 13 passes through the screw hole 26. Then, the end of the screw hole 26 is hooked on the inclined portion 16 as shown in FIG. 6, and the nut is centered. Thereafter, when the movable electrode 19 advances, the small-diameter portion 15 enters into the receiving hole 32, and when the end surface of the movable electrode comes into close contact with the upper surface of the nut 25 and further descends, the guide pin 13 is forcibly pushed down ( At this time, when the air from the air cylinder is exhausted, the guide pin can be smoothly pushed down.) Then, the nut 25 is pressed against the steel plate part 17, and the projection welding is completed through the sequence of energization and welding. The inner diameter of the screw hole 26 can be understood from FIG.
The diameter is smaller than that of the small diameter portion 15.

The above-described operation sequence and the operation sequence of the embodiment described later can be easily implemented by adopting a commonly used electric control type air switching valve or electric control circuit. Therefore, disclosure of a specific example is omitted here. In all the embodiments, illustration of an air hose to be connected to an air cylinder is omitted.

Next, the embodiment shown in FIG. 4 will be described.
In the previous embodiment, the concave portion 21 is opened upward as shown in FIG. 2, but FIG. FIG. 4 differs from FIG. 4 only in the opening direction and is otherwise the same. Therefore, the same reference numerals as those in the previous embodiment are used and the detailed description is omitted. However, since the concave portion 21 is opened downward, the method shown in FIG. 5 is illustrated as an example of a method of supplying components to the concave portion 21. That is, the support member 38 is firmly fixed to the stationary member 9, and the supply chute 39 is fixed thereon. This shooter has a U-shaped cross section and is open upward, and extends in a direction perpendicular to the plane of FIG. An air cylinder 40 is fixed below the support member 38, and a piston rod 42 of the air cylinder passes through a through hole 41 opened in the support member 38. A through hole 43 is also formed in the bottom plate of the supply shooter 39 so as to be continuous with the through hole 41. The recess 21 of the supply rod 20 is located just above the nut 25. In FIG. 4, it is also possible to magnetize the vicinity of the concave portion 21 by the electromagnetic coil 48 and stop the magnet 28.

When the piston rod 42 rises by the operation of the air cylinder 40 from the state shown in FIG. 5, the nut 25 is lifted and supplied into the recess 21 and is attracted by the magnet 28.

The embodiment shown in FIG. 7 is different from the previous embodiment only in that the fixed electrodes are upside down, and all the other parts have the same configuration. Therefore, the same reference numerals are entered and detailed description is omitted. When the supply rod 20 retreats, the nut 25 falls on the upper surface of the movable electrode 19, so it is necessary to prevent the nut 25 from falling. For this purpose, the small-diameter portion 15 is previously inserted into the receiving hole 32 as shown by a two-dot chain line, or the tip of the small-diameter portion 15 is brought to a position immediately near the upper surface of the electrode to guide the nut 25 when it falls. The small diameter part 1
Let 5 fulfill. This embodiment is suitable for a case where a nut is welded inside a part having a U-shaped cross section.
In FIG. 7, a U-shape is formed by three members: a plate material shown on the back side of the steel plate 17, a plate material (not shown) on the front side of the steel plate 17, and the steel plate 17 itself.

The embodiment of FIG. 8 differs from the previous embodiment in the shape of the guide pins. That is, instead of having a large diameter portion and a small diameter portion, a short tapered portion 44 is provided at the distal end of the guide pin 13.
This portion enters the screw hole 26, and the small diameter portion does not completely penetrate the screw hole as described above. In FIG. 8, the concave portion 21 is opened upward, but when the concave portion 21 is opened downward, the notch groove 24 becomes unnecessary because the guide pin does not pass through the screw hole. Therefore, claim 1 does not describe the notch groove as a requirement.

In the embodiment shown in FIGS. 11 to 13, the guide pin is provided with a suction means so that the relative position of the nut 25 and the guide pin 13 in the rotational direction does not change. Various methods are conceivable for the suction means. Here, the case where a magnet is used and the case where suction is performed by air vacuum are illustrated. First, FIG.
In the following description, the magnet 49 is embedded near the inclined portion 16 and the nut 25
When the nut 25 remains on the inclined portion 16, the nut 25
6, so that no displacement occurs in the rotational direction.
The method of embedding the magnet 16 as shown in the drawing is to cut the guide pin 13 at the upper part of the large-diameter portion 14, provide a recess in the cut end face, fit the magnet 49 therein, and then weld the guide pin 13 again. And finish the outer surface smoothly.

The case where the vacuum shown in FIGS. 12 and 13 is used will be described. In this case, the end face 50 is formed without a slanted portion 16 as described above and formed on a plane perpendicular to the axis of the guide pin 13 as shown in the figure. Are provided, and a plurality of air passages 51 are opened here, and these passages are connected to a vacuum pump (not shown). That is, a joint pipe 52 communicating with the air passage 51 is fixed to the guide pin 13 and a flexible air hose 53 is connected thereto. Then, in order to allow the joint tube 52 to freely advance and retreat with respect to the fixed electrode 11, a long hole 5 in the reciprocating direction is provided in the fixed electrode 11.
4 is formed. When the lower surface of the nut 25 comes into close contact with the end surface 50 and a vacuum acts, the nut 25 is sucked by the end surface and does not easily shift in the rotation direction.

In the embodiment described above, it is assumed that the fixed electrode is completely stationary. However, an electrode corresponding to the fixed electrode may advance together with the movable electrode, or the fixed electrode may be advanced. It is also possible to make only the electrode corresponding to. FIG. 9 shows the former case.
It is shown in In this case, the base 10 is supported from below by a driving means 45, and an air cylinder 46 is employed as this means. The air cylinder 46 is firmly fixed on the stationary member 9 and its piston rod 47 is attached to the base 1.
Tied to 0. Therefore, when the movable electrode 19 advances, the fixed electrode 11 also advances, which is effective for shortening the operation time.

As described above, since both electrodes advance, or only one of the electrodes advances, no distinction is made between a fixed electrode and a movable electrode as a requirement of the present invention. It has been done.

[0021]

According to the present invention, the projection nut held by the holding means in the recess of the supply rod is moved backward after the guide pin of the electrode which has advanced has entered the screw hole of the projection nut. Therefore, since the projection nut is prohibited from moving in an abnormal direction in both the concave portion and the guide pin, it is possible to surely solve a problem such as a displacement of the nut due to a drop in the prior art. This enables welding as an apparatus or method regardless of whether the axis of the electrode is vertical or horizontal. Since the cutout groove is provided in the bottom plate of the concave portion so as to be open to the distal end side of the supply rod, even if the guide pin passes through the screw hole of the nut, the supply rod can be retracted.
In this way, since the guide pin can penetrate the nut like a skewer, the holding state of the nut is further stabilized. Since the guide pin has a large diameter portion, a small diameter portion, and an inclined portion, the small diameter portion securely penetrates the nut, thereby increasing the holding stability, and further, due to the relationship between the inclined portion and the end of the screw hole. In addition, the nut is centered, and the welding position of the nut can be obtained with high accuracy. Since the other electrode has a small-diameter portion receiving hole, when the two electrodes come close to each other and welding is performed, the small-diameter portion does not interfere with the other electrode, and reliable operation can be obtained. When the supply rod returns after the small-diameter portion enters the receiving hole, abnormal movement of the nut is restrained, so that positioning of the nut is guaranteed. The supply rod is a simple reciprocating operation, and the guide pin advances and retreats in a direction almost perpendicular to this, so that nut supply by the supply rod and nut restraint by the guide pin are realized under extremely simple operation, and the welding method As a result, highly reliable operation can be obtained. Since the guide pin is provided with suction means for the nut, when only the nut remains on the guide pin, the nut is attracted to the guide pin, and therefore,
Even if some external force acts on the nut, the nut does not easily move in the rotation direction. In this way, the nut is always welded in a uniform direction to the mating part. The effect that can be described from the structure of the embodiment is that, by forming a concave portion as shown in FIG. 2 that matches a square nut, the nut can be reliably held and held.
This is very advantageous for holding the nut during the movement of the supply rod. Since the concave portion of the supply rod also serves to position the nut in the rotation direction, the relative position of the nut with respect to the guide pin is also made uniform, so that the displacement by the suction means and the correct setting of the welding position can be achieved. It is definitely done.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view showing an embodiment of the present invention.

FIG. 2 is a three-dimensional view showing a concave portion at a distal end portion of a supply rod.

FIG. 3 is a sectional view taken along line (3)-(3) of FIG. 1;

FIG. 4 is a longitudinal sectional side view showing another embodiment.

FIG. 5 is a vertical sectional side view showing supply of components to a concave portion.

FIG. 6 is a side view showing a relationship between a guide pin and a screw hole.

FIG. 7 is a longitudinal sectional side view showing another embodiment.

FIG. 8 is a longitudinal sectional side view showing another embodiment.

FIG. 9 is an external side view of the case where both electrodes advance.

FIG. 10 is a longitudinal sectional side view of the prior art.

FIG. 11 is a longitudinal sectional side view in which a magnet is embedded in a guide pin in another embodiment.

FIG. 12 is a longitudinal sectional side view in which a vacuum is adopted in another embodiment.

FIG. 13 is a partially enlarged longitudinal sectional side view of FIG. 12;

[Explanation of symbols]

 Reference Signs List 20 supply rod 11, 19 electrode 25 projection nut 21 recess 28 holding means 26 screw hole 13 guide pin 23 bottom plate 24 cutout groove 14 large diameter part 15 small diameter part 16 inclined part 32 receiving hole 49, 51 suction means

Claims (6)

[Claims] An advancing and retreating direction of a supply rod is set to a direction substantially orthogonal to an axis of an electrode, and a concave portion for holding a projection nut opened to the distal end side is formed at a distal end portion of the supply rod. The projection nut holding means is installed in the projection nut, and the guide pin which enters the screw hole of the projection nut stopped at a position substantially coaxial with the electrode is installed so as to be able to advance and retreat to the electrode. Projection nut welding equipment. 2. The projection nut welding apparatus according to claim 1, wherein a cutout groove for passing a guide pin is formed in the bottom plate of the concave portion so as to open to the tip end side of the supply rod. 3. The guide pin according to claim 2, wherein the guide pin comprises a large-diameter portion and a small-diameter portion, an inclined portion is provided at a boundary between these two diameter portions, and the small-diameter portion penetrates a screw hole of the projection nut. A projection nut welding apparatus, wherein an inclined portion is configured to engage with an end of the screw hole. 4. The projection nut welding device according to claim 3, wherein a receiving hole for receiving the small diameter portion is opened in the other electrode. 5. The supply rod has a reciprocating direction set substantially perpendicular to the axis of the electrode, and a distal end portion of the supply rod is provided with a concave portion for holding a projection nut opened to the distal end side. The projection nut holding means is installed at the position, and after stopping the projection nut at a position substantially coaxial with the electrode, the guide pin of the electrode comes out, enters the screw hole of the projection nut, and enters this state. The welding rod is retracted so that the projection nut remains engaged with the guide pin, and then the electrode advances to complete the welding. 6. The welding device for a projection nut according to claim 1, wherein the guide pin is provided with suction means for preventing a displacement of the projection nut.