JP2898585B2 - Electrode device for resistance welding and resistance welding device including the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resistance welding electrode device and a resistance welding device including the same.

[0002]

2. Description of the Related Art Conventionally, in order to tighten a tire of a vehicle, a hub bolt 51 is implanted in a hub 50 as shown in FIG. That is being done. The flange portion 53 of the hub nut H is pressed against the wheel 52 via the washer 54. Here, as shown in FIG. 13, a hub nut H in which a cap C is integrated with an outer open end of a nut main body N by resistance welding may be used. That is, the flange 53
Of the cylindrical portion 55 and the hexagonal portion 56 formed on both sides of
A container-shaped cap C is resistance-welded to the outer end surface of the hexagonal portion 56 to form a hub nut H with a cap.

[0003] In order to obtain a hub nut H in which the cap C is welded to the nut main body N, for example, a resistance welding apparatus shown in FIG. 10 is used. In this device, the cylindrical portion receiving member 1 and the cylindrical portion pushing member 2 for positioning the cylindrical portion 55 of the nut body N as the first member at the welding position, and the hexagonal portion receiving member 3 for positioning the hexagonal portion 56 of the nut body N
And a cap receiving member 5 for positioning a cap C as a second member at a welding position concentric with the nut body N while providing a first positioning device such as a hexagonal extrusion member 4 and the like.
And a second positioning device such as a cap push-out member 6. In this example, the cylindrical portion receiving member 1 and the hexagonal portion receiving member 3 are provided in a fixed position, and the cap receiving member 5 is urged by the spring 7 to the forward end position. on the other hand,
The cylindrical extruding member 2 and the hexagonal extruding member 4 are slide substrates 8.
, And the cylinder 8 a
And the like by means of the pushing means. The cap pushing member 6 is connected to the slide substrate 8 via a spring 9 and normally moves forward and backward together with the cylindrical pushing member 2 and the hexagon pushing member 4.

[0004] Then, the cylindrical extruding member 2, the hexagonal extruding member 4 and the cap extruding member 6 are formed by the slide substrate 8.
In the retracted end position retracted to the right side in FIG. 10, in a nut assembly supply step, the nut main body N and the cap C are positioned relative to each other by the respective part feeders (not shown). The nut body N and the cap C are supplied to the leading end positions of the push members 2, 4 and 6 in the orientation and the positional relationship in which the cap C is placed on the upper opening end surface.

Next, as a setting process of the nut assembly,
The cylindrical portion pushing member 2 abuts on the cylindrical portion of the nut body N, the hexagonal portion pushing member 4 abuts on the hexagonal portion of the nut body N, and the cap pushing member 6 abuts on the cap C. While maintaining the above positional relationship, these are advanced to the advanced end position via the slide board 8 by the cylinder 8a, and such a nut assembly is set to the welding position on the lower die 10. At this time, the nut body N
Is sandwiched between the cylindrical receiving member 1 and the cylindrical pushing member 2, the hexagonal portion 56 of the nut body N is sandwiched between the hexagonal receiving member 3 and the hexagonal pushing member 4, and the cap C
Are sandwiched between the cap receiving member 5 and the cap pushing member 6 and held at the welding position.

The cap receiving member 5 is provided with a roller 12 via a bracket 11a, and a cap pushing member 6.
Also, a roller 13 is provided via a bracket 11b so as to face each other in the horizontal direction. The approach limit of these rollers 12 and 13 is defined by stoppers 14 and 15, respectively.

When the above-described setting process is completed, the electrode member 60 is lowered by the lifting device 62 such as a cylinder, and the conical cam 20 mounted on the outer peripheral portion of the electrode member 60 is fixed to the roller 12 of the cap receiving member 5 and the cap 12. It hits the roller 13 of the pushing member 6. When the electrode member 60 is further lowered, the conical cam 20 pushes and spreads the rollers 12 and 13 in a direction away from each other while rotating them. Therefore, FIG.
As shown in FIG. 1, as the electrode member 60 descends, both the cap receiving member 5 and the cap pushing member 6 are retracted against the urging forces of the respective springs 7 and 9, and the cap C
Is released, and the cap C is retracted to a position away from the welding position.

Thereafter, the electrode portion 33 at the tip of the electrode member 60 which further descends is pressed against the cap C, and in this state, the welding current is reduced by the voltage applied between the electrode holder 61 and the lower mold 10. C flows into the nut body N, and the cap C is resistance-welded to the opening end face of the nut body N over the entire periphery of the opening edge.

[0009]

Here, the electrode member 60 is used.
As the cap receiving member 5 and the cap pushing member 6 are retracted in the direction away from each other by the conical cam 20 with the downward movement of the cap member C, the electrode member 60 temporarily presses the cap C against the nut body N. However, the cap C is in an unconstrained state. In most cases, there is almost no problem,
In rare cases, the cap C may be displaced from the set position in an unconstrained state. In such a case, the nut body N and the cap C are welded in a misaligned state, which causes defective products. For this reason, this kind of nut
In order to remove defective products, inspection of all products is usually performed, but this takes a lot of trouble and contributes to an increase in cost.

An object of the present invention is to provide an electrode device which prevents a second member such as a cap from being in an unconstrained state when a positioning device such as a cap receiving member and a cap pushing member is retracted, and includes the electrode device. An object of the present invention is to provide a resistance welding apparatus.

[0011]

Means, actions and effects for solving the problem.
According to the invention, when the first member such as the nut body and the second member such as the cap are positioned and the second member is resistance-welded to the first member, an electrode having an electrode portion at a tip end portion is provided. The main body is provided with a pressing member for pressing the second member against the first member. The electrode body performs resistance welding in a state where its own electrode portion contacts the second member and presses the second member against the first member.

The above-mentioned pressing member is provided on the electrode main body so as to be able to advance and retreat, and is urged by urging means so as to protrude from the electrode portion to the tip end side. The pressing member is pressed against the second member prior to the electrode portion, and in a process in which the electrode body relatively approaches the second member, the pressing member is maintained on the electrode body while maintaining the pressed state. It is pushed back against the urging force of the urging means. Generally, an elastic member such as a spring is used as the urging means.

[0013] Thus, before the electrode portion comes into contact with the second member, the pressing member contacts the second member, and while the pressing state is maintained, the electrode portion contacts the second member. Since this is pressed against the first member to perform resistance welding, the second member is prevented from being displaced from the first member in the welding process, in other words, in the approaching process of the electrode portion.

According to the second aspect of the invention, the first and second members are positioned at the welding position by the first and second positioning devices, and the second positioning device is moved to the second position before the resistance welding. The electrode device as described above is used in a resistance welding device that retreats from the above member. That is, when the electrode body presses the second member against the first member and performs resistance welding, before or after the second positioning device retreats from the second member, the second positioning device applies the second member to the second member. The pressing member is pressed. Then, in a process in which the electrode main body relatively approaches the second member, the pressing member is pushed back to the electrode main body side while maintaining the pressed state, and finally the electrode portion is the second member. If resistance welding is performed by being pressed against the second member, it is possible to prevent the second member from being in an unconstrained state after the second positioning device is retracted. Accordingly, there is no possibility that the second member will be displaced from the first member.

According to a third aspect of the present invention, there is provided a resistance welding apparatus including an electrode device having the above-described pressing member. The requirements include first and second positioning devices for positioning the first and second members at the welding position, respectively, and positioning retraction for retracting the second positioning device from the second member before the resistance welding. It relates to a combination of the device and the above-described electrode device.

It is to be noted that the present invention has the following features.
In addition, the first and second members are suitable for the nut body and its cap, respectively, but are not limited thereto, and can be applied to an electrode device for resistance welding various parts and members. Further, as described in claim 5
In addition, the electrode body has an electrode portion at a tip portion thereof,
The pole part is formed in a concave shape corresponding to the outer shape of the second member.
The rod-shaped holding member is axially moved to the electrode body.
It is movably held, and this holding member is
Smaller in diameter, concentric with the electrode body and in the recess
Arranged so that it passes through the center and protrudes from the tip of the electrode body
The tip surface of the holding member is the second member
, The electrode portion is the second in the concave portion
Cover the member and press it against the first member to
At the time of anti-welding, the tip surface of the holding member is
It is pushed back to the bottom of the concave part against the urging means.
Can be done. Thereby, the first and second parts
There is no danger that the material will be misaligned. Further, in claim 6
As described, the electrode body is formed by an upper member and a lower member.
It has a two-part structure, and the retainer is located in the axial direction of the lower member.
A guide hole for slidably holding the member,
Spring accommodation hole is formed to accommodate all compression springs
The lower part has a tapered outer peripheral surface at the upper end.
And the lower end of the upper member is fitted with a
Inner peripheral surface is formed, and by fitting these
The upper member and the lower member may be integrated.
it can. In this way, the electrodes are worn out by use
In this case, only the lower member needs to be replaced,
It will be cheaper. In addition, as in claim 7, the above-mentioned holding part
The material is a non-magnetic material such as stainless steel
Manufactured by the company. More magnetic of this
Without adsorbing welding spatter.
In order to avoid this, the second member is dented by the adsorbed spatter.
I don't have to.

[0017]

Embodiments of the present invention will be described below with reference to embodiments shown in the drawings. FIG. 1 is an overall view of a resistance welding apparatus according to one embodiment. The electrode device 30 includes an electrode body 31, and a tapered cam such as the conical cam 20 as a positioning and retracting device is fixed to the electrode body 31. The electrode body 31 has an electrode portion 33 at the tip thereof, and the electrode portion 33 is formed in a concave shape corresponding to the outer shape of the cap C set in the opening of the nut body N described above. That is, as shown in FIG. 5, a concave portion 32 for accommodating all or substantially the upper half of the cap C is formed on the front end (lower end) surface of the electrode main body 31.
The electrode portion 33 is formed concentrically with the electrode portion 1. In FIG. 5, the above-mentioned conical cam 20 is omitted.

The electrode body 31 has a rod-shaped pressing member 34.
Are held so as to be movable in the axial direction (in this example, the vertical direction). The holding member 34 has a smaller diameter than the tip of the electrode body 31, is concentric with the electrode body 31, passes through the center of the recess 32 (see FIG. 6), and
Is arranged so as to protrude downward from the tip of the. The protrusion limit is determined by the flange 3 formed on the upper end of the holding member 34.
5 is defined by contacting a stopper surface 36 formed on the electrode body 31. The pressing member 34 is normally urged by a compression spring 37 to a protruding limit at which the flange 35 comes into contact with the stopper surface 36, and the distal end surface of the pressing member 34 contacts the upper surface of the cap C, and the electrode portion 33 is The cap 32 is put on the cap C in the concave portion 32, and is pressed against the nut body N to perform resistance welding. At this time, the distal end surface of the pressing member 34 is pushed back to the bottom surface of the concave portion 32 of the electrode portion 33 while compressing the compression spring 37.

In this example, the electrode body 31 has a two-part structure of an upper member 40 and a lower member 41, and a guide hole 42 for slidably holding the holding member 34 in the axial direction of the lower member 41. A spring accommodation hole 43 for accommodating the compression spring 37 is formed. A female screw hole 44 is formed in an upper part of the spring receiving hole 43, and a spring receiving member 45 is screwed into the female screw hole 44. This spring receiving member 45
By fitting a tool into the hexagonal hole 46 (see also FIG. 8) formed and turning the spring 37, the spring 37 can be mounted and the spring force can be adjusted.

The upper end of the lower member 41 has a tapered outer peripheral surface 4.
8 is formed, and a tapered inner peripheral surface 49 that fits with the lower end of the upper member 40 is formed, and the upper member 40 and the lower member 41 are integrated by these fittings. . On the upper part of the upper member 40, a tapered outer peripheral surface 4 is further provided.
7 is formed, and the electrode main body 31 is attached to the holder 6 shown in FIG.
1 and moved up and down by a lifting device 62 such as a cylinder. The upper member 40 and the lower member 41 are formed with two chamfered portions 56 and 58 for engaging a tool for disassembling them, respectively (see also FIGS. 7 and 9).

In this case, the electrode body 31 may be constituted by an integral structure instead of the two-part structure of the upper member 40 and the lower member 41. When 33 is worn out due to use, only the lower member 41 needs to be replaced, so that the tool cost is reduced. Further, if necessary, the lower member 41 may be further divided into an upper portion and an electrode portion 33 so as to have a configuration of three or more divisions as a whole.

Also, in this example, the upper member 40 and the lower member 4
Since 1 is integrally assembled by taper fitting,
The two members 40 and 41 can be brought into contact with each other over a wide area, and the current-carrying resistance can be reduced. However, the present invention is not limited to the assembling mode of the taper fitting.

The pressing member 34 can be made of a non-magnetic material such as stainless steel, for example. By doing so, the magnet is not magnetized, and the magnetic attraction of the welding spatter is avoided, so that the cap C is not dented by the adsorbed spatter. In addition, this holding member 34 is cost-effective.
From the viewpoint of workability and the like, stainless steel is desirable, but other metals or insulators may be used as long as they are not magnetized and can withstand welding heat.

Next, the operation will be described. As shown in FIG. 1, the nut body N and the cap C are positioned on the lower mold 10 in an assembled state. This positioning step is the same as the conventional one, and is as described above. The electrode body 31 descends toward the nut assembly (N, C). In this process, before the conical cam 20 hits the roller 12 of the cap receiving member 5 and the roller 13 of the cap push-out member 6, the tip of the pressing member 34 first hits the upper surface of the cap C as shown in FIG. At this time, the tip of the pressing member 34 does not interfere with the cap receiving member 5 and the cap pushing member 6. That is,
As shown in FIG. 3, the tip of the holding member 34 is a cap C
This is because the cap receiving member 5 and the cap pushing member 6 restrain the lower side of the side of the cap C from both sides. When the electrode body 31 further descends from this state, the pressing member 34 is pushed into the inside of the electrode body 31 against the spring force of the compression spring 37, and the cap C is pressed against the upper surface of the nut body N by the reaction force. Keep in state.

As shown in FIG. 4, the electrode main body 31 further descends, and the conical cam 20 hits the rollers 12 and 13 and pushes the rollers 12 and 13 to both sides to thereby spread the cap receiving member 5.
And the cap pushing member 6 is retracted from the cap C integrally therewith and against the urging force of the springs 7 and 9,
The cap C is retracted to a position away from the welding site. However, even when the members 5 and 6 are separated from the cap C, the cap C is kept in a restrained state because the pressing member 34 still presses the cap C against the nut body N. In this state, the concave portion 3 of the electrode portion 33
2 covers at least the upper part of the cap C, and further presses the cap C pressed by the pressing member 34 against the nut body N. In this state, the lower mold 1 is
The welding current flows to zero, and the entire periphery of the lower opening edge of the cap C is resistance-welded to the upper surface of the nut body N.

Thus, in the process of lowering the electrode body 31,
Before the positioning of the cap C by the cap receiving member 5 and the cap pushing member 6 is released, the pressing member 34 presses the cap C against the nut body N, and further the electrode portion 3
3 performs resistance welding while pressing the cap C against the nut body N, so that there is no possibility that the cap C will be misaligned with respect to the nut body N. This eliminates the occurrence of defective products and the necessity of inspection of all products.

When the resistance welding is completed as described above, the electrode body 31 rises, and the cap receiving member 5 and the cap pushing member 6 return to the forward end position by the urging forces of the springs 7 and 9 as the conical cam 20 rises. (Same position as the setting process completion position). When the raising operation of the electrode main body 31 is completed, the slide board 8 of the pushing members 2, 4 and 6 is retracted to the nut assembly supply position (retracting end) by the cylinder 8a and the like, and the pushing members 2, 4 and 6 and the like are initially To the retracted end position.

Thereafter, by a pusher mechanism (not shown),
The welded hub nut H with cap is pushed out from the welding position to a discharge portion such as a shooter. When the nut dispensing by the pusher mechanism is completed, the cycle returns to the beginning, and the cycle of starting the supply of the nut assembly is repeated.

[Brief description of the drawings]

FIG. 1 is an overall schematic diagram showing one embodiment of the present invention.

FIG. 2 is a process diagram showing a lowering process of the electrode main body.

FIG. 3 is an enlarged view showing a main part thereof.

FIG. 4 is a process chart showing a welding process of the electrode body.

FIG. 5 is a half sectional view showing the electrode body (with the conical cam removed) shown in FIG. 1;

FIG. 6 is a bottom view thereof.

FIG. 7 is a plan view thereof.

FIG. 8 is a sectional view taken along line AA of FIG. 5;

FIG. 9 is a sectional view taken along line BB of FIG. 5;

FIG. 10 is an overall schematic view of a conventional resistance welding apparatus for obtaining a hub nut with a cap.

FIG. 11 is a process chart showing the conventional operation.

FIG. 12 is a sectional view of a tightened state of a hub nut with a cap, which is an example of a welding target.

FIG. 13 is a side view showing a welding form between the cap of the hub nut and the nut body.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylindrical part receiving member 2 Cylindrical part pushing member 3 Hexagon part receiving member 4 Hexagon part pushing member 5 Cap receiving member 6 Cap pushing member 12, 13 Roller 30 Electrode device 31 Electrode main body 33 Electrode part 34 Holding member 37 Compression spring 40 Upper member 41 Lower member N Nut body (first member) C Cap (second member)

Claims (7)

(57) [Claims] An electrode for a resistance welding device for resistance welding a second member to a first member in a state where the first and second members are positioned at a welding position by the first and second positioning devices. An electrode body provided with an electrode portion at a distal end portion, the electrode portion being in contact with the second member and performing resistance welding in a state where the electrode portion is pressed against the first member; and It is provided so as to be able to advance and retreat, and is urged by urging means so as to protrude to the tip side from the electrode portion, and when the electrode body presses the second member against the first member and performs resistance welding. The urging means is pressed against the second member prior to the electrode portion, and the urging means is pressed toward the electrode body while maintaining the pressed state in a process in which the electrode body relatively approaches the second member. Is pushed back against the urging force of Resistance welding electrode device which comprises a member. 2. In order to resistance-weld a second member to a first member, the first and second members are positioned at a welding position by first and second positioning devices, and the resistance welding of the first and second members is performed. An electrode device for a resistance welding device for retracting the second positioning device from the second member, comprising an electrode portion at a tip portion, wherein the electrode portion contacts the second member. An electrode body that performs resistance welding while pressing the first member against the first member; and an urging means that is provided on the electrode body so as to be able to advance and retreat, and protrudes from the electrode portion toward the tip end. With, when the electrode body presses the second member against the first member and performs resistance welding, before or when the positioning device for the second member retreats from the second member, the Prior to the electrode part on the second member And a pressing member pressed back against the urging force of the urging means toward the electrode main body while maintaining the pressing state in a process in which the electrode main body relatively approaches the second member. An electrode device for resistance welding, comprising: 3. A resistance welding device for resistance welding a second member to a first member, wherein the first member is positioned at a welding position, and the second member is welded. A second positioning device for positioning at a position, a positioning retracting device for retracting the second positioning device from the second member before the resistance welding, and a second positioning device configured by the positioning retracting device. Withdrawing from the second member, after the positioning state of the second member is released, having an electrode device that performs resistance welding by pressing the second member against the first member, and The electrode device includes an electrode portion at a distal end portion, and the electrode portion contacts the second member and applies a voltage while pressing the second member against the first member. So that it is possible to When the electrode main body presses the second member against the first member and performs resistance welding, the second positioning device is configured so that Before or when retreating from the second member,
Pressed against the second member prior to the electrode portion,
And a pressing member that is pushed back to the electrode main body side against the urging force of the urging means while maintaining the pressing state in a process in which the electrode main body relatively approaches the second member. A resistance welding device characterized by the following. 4. The hub member according to claim 1, wherein the first member is a hub nut body, and the second member is a cap for covering a threaded opening of the hub nut body. 3. The electrode device for resistance welding according to claim 1, wherein the cap is pressed against the end face of the hub nut body while the cap is pressed against the end face of the hub nut body . 4. 5. The electrode body has an electrode portion at a tip end thereof, the electrode portion is formed in a concave shape corresponding to the outer shape of the second member, and the electrode body has the bar-shaped holding member. The holding member is movably held in the axial direction, and the pressing member has a smaller diameter than the tip of the electrode body, and projects from the tip of the electrode body concentric with the electrode body and through the center of the recess. The tip surface of the pressing member hits the upper surface of the second member, the electrode portion covers the second member in the concave portion, and presses this against the first member. be adapted to resistance welding, the tip end face of the pressing member in doing so, according to claim 1, 2 or 4 to the bottom surface of the recess of the electrode portions so that the pushed back against the biasing means Electrodes for resistance welding
apparatus. 6. The electrode main body has a two-part structure of an upper member and a lower member, a guide hole for slidably holding the pressing member in the axial direction of the lower member, and A spring accommodating hole for accommodating the compression spring is formed, a tapered outer peripheral surface is formed at an upper end of a lower member thereof, and a taper inner peripheral surface to be fitted with the tapered outer peripheral surface is formed at a lower end of the upper member. And the upper member and the lower member are integrated by these fittings .
6. The electrode device for resistance welding according to 2, 4, or 5. 7. The holding member is made of a non-magnetic material such as stainless steel .
7. The electrode device for resistance welding according to 4, 5, or 6.