JP3508366B2 - Positioning device for spot welding of grooved work - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning device for performing spot welding at a welding position of a thin groove formed on a work of a plate member.

[0002]

2. Description of the Related Art In a vehicle such as an automobile, a body is composed of a plurality of outer plates joined by spot welding. Such a joint between the outer plates and the outer plate has been conventionally used. It is known that the stepped portions formed on each other are overlapped with each other to form a groove shape, and spot welding is performed at the groove portions to join them. As a positioning mechanism of such a spot welding apparatus, for example, the present application is applied. The person is Japanese Patent Application No. 7-737
34, Japanese Patent Application No. 7-98710, Japanese Patent Application No. 7-1086
No. 79, Japanese Patent Application No. 7-175069, Japanese Patent Application No. 7-175
There is a proposal such as No. 071.

This is spot welding of the bottom of a groove portion in which plate-like works are superposed, and for example, a roof panel 90 and a body side panel 91 (for example, a rear fender of a vehicle body 9 as shown in FIG. 4 are formed. It is used for welding with rear water panels, etc., and as shown in Fig. 5,
Steps 90A and 91A respectively provided on the ends of the roof panel 90 and the body side 91 are overlapped with each other,
The groove 92 having a substantially rectangular cross section (cross section in the transverse direction of the groove) is formed.

Then, as shown in FIG. 4, the bottom portion 92A of the groove portion 92 is sandwiched between the welding tip 5 and the electrode 6 of the gun unit 2 attached to the robot 1, pressed, and energized to perform spot welding.

Since the groove portion 92 opens toward the outside of the body, the width W of the inner circumference of the groove portion 92 in FIG. 5 is set to be narrow, for example, a narrow groove width of 6 mm or the like to ensure the aesthetic appearance of the vehicle body. However, post-treatment steps such as brazing can be eliminated.

The welding tip 5 inserted into the inner periphery of the groove 92 having such a narrow width has a groove 92 other than the welding position.
In order to secure a predetermined contact area and ensure welding quality while avoiding contact with the inner peripheral side surface of the
A tapered welding tip 5 whose tip is formed in a plate shape is known. The tapered welding tip 5 has a base end supported by the gun unit side made of a columnar member or the like, and a bottom end of the columnar member. Is formed with a plate-shaped portion 50 having a substantially rectangular cross section, and the plate-shaped portion 50 has a thickness equal to the inner peripheral width W of the groove 92.
It is set to a smaller value, such as 4 mm. Then, by positioning the plate-like portion 50 substantially along the center of the groove portion 92 or the like, it is possible to avoid contact with the inner peripheral side surface of the narrow groove portion 92, and to perform spot welding of the bottom portion 92A smoothly. .

The welding tip 5 is positioned on the inner circumference of the groove 92 by feeding back a detection signal from a contact or non-contact type sensor attached to the gun unit 2 to the robot 1 or on one inner peripheral side surface of the groove 92. This is performed by a tracing means that mechanically abuts or a tracing means that inserts a tracing piece having a width equal to the width of the groove portion 92 into the groove portion 92.

[0008]

However, as in the above-mentioned conventional example, the tapered welding tip 5 is formed in the narrow groove portion 92.
Accurate positioning on the inner circumference of the robot is performed by an automatic welding device such as a robot.Therefore, when welding is performed at different positions due to changes in the work, it takes a lot of time for the setup process such as teaching of the robot. However, it is necessary to perform spot welding manually when the automatic welding device fails, but as described above, the welding tip 5 is accurately positioned in the narrow groove portion 92. There was a problem that it was difficult to do.

Therefore, the present invention has been made in view of the above problems, and an object thereof is to provide a spot welding apparatus capable of manually and accurately positioning a welding tip in a narrow groove portion.

[0010]

SUMMARY OF THE INVENTION A first invention comprises a groove portion in which plate-like works having a bent portion are superposed, a first welding tip and an electrode which are supported so as to be relatively displaceable in the axial direction. In a spot welding machine that clamps, presses, and energizes the groove with a gun unit, the first guide member is configured to be detachable from the work and engageable with the inner circumference of the groove, A chip support member that is attached to the first guide member and is displaceable toward the groove portion of the workpiece, and is fixed to the chip support member, and is capable of contacting and separating toward a predetermined welding position of the groove portion. A supported second welding tip and a second guide member that is hinge-coupled to the first guide member and that can face the back surface of the groove portion,
An electrode guide member for guiding the electrode to a position facing the second welding tip and a locking means for selectively connecting the second guide member and the first guide member are provided.

In a second aspect based on the first aspect, the first guide member includes a plurality of second welding tips along the groove portion, and the second guide element corresponds to each second welding tip. A plurality of electrode guide members are provided, and an elastic member that urges the second welding tip in a direction away from the work is interposed between the tip support member and the first guide member.

In a third aspect based on the first aspect, the second welding tip has a plate-like portion whose tip can be inserted into the groove inner circumference, while the tip supporting member is 2 The rotation of the welding tip about the axis is restricted, and the plate-like portion is arranged along the groove.

In a fourth aspect based on the second aspect, the first guide member is provided with a tip guide for guiding the first welding tip of the gun unit along the groove portion, while the second guide is provided. The member is provided with an electrode guide for guiding the electrode of the gun unit along the groove.

[0014]

According to the first aspect of the invention, the first guide member and the second guide member constituting the positioning device are relatively rotatable via a hinge, and the first guide member can be moved with the locking means released. After engaging the groove portion of the work, the second guide member is coupled to the first guide member by the locking means, and the second welding tip supported by the first guide member has a predetermined welding position facing the inner circumference of the groove portion. Be positioned at. Then, the electrode of the gun unit is positioned on the back surface of the groove portion facing the second welding tip by the electrode guiding member, and then the first welding tip of the gun unit is brought into contact with the second welding tip of the first guiding member or the tip supporting member. Then, the second welding tip clamps and presses the work between the electrode and the second welding tip, and then the second welding tip conducts the spot welding through the second welding tip. You can After welding is completed, the positioning device can be easily removed from the work by releasing the locking means, and the positioning of the gun unit is performed by engaging the electrode with the electrode guide member and then the first welding tip with the second welding tip. Alternatively, the gun unit only needs to be brought into contact with the tip support member, and the gun unit only needs to be roughly positioned. Even when the width of the groove is narrow, spot welding of the inner circumference of the groove can be performed manually and quickly.

According to a second aspect of the invention, the first and second guide members each include a plurality of second welding tips and electrode guide members along the groove, and the tip supporting member of the second welding tip is always made of an elastic member. Since it is urged away from the work, welding can be performed sequentially while moving the gun unit along the groove, and welding at multiple points along the groove can be performed continuously without removing the positioning device from the work. It can be carried out.

In a third aspect of the invention, the second welding tip is
The tip supporting member is configured by a plate-shaped portion that can be inserted into the groove inner circumference, and the tip support member of the first guide member restricts the rotation of the second welding tip about the axis, and the plate-shaped portion extends along the groove portion. Since it is arranged, even if the width of the groove is narrow, the plate-shaped portion can surely weld, and since the support member restricts the rotation around the axis, the plate-shaped second welding tip is in contact with the inner circumference of the groove. It is possible to secure welding quality.

The fourth invention is the first of the gun unit.
The welding tip and electrode are guided along the groove by the tip guide and electrode guide provided in the positioning device, so when moving the gun unit manually, the gun unit does not significantly shift from the groove, Can be welded quickly.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 to 3 show an example in which the present invention is applied to spot welding a vehicle body outer plate having a thin groove portion as a work. The vehicle body 9 as the work is shown in FIG. ~ Similar to FIG. 6, the roof panel 90 of the vehicle body 9
And the bottom portion 92A of the inner periphery of the groove portion 92 at the end portion of the body side panel 91 are joined to each other, so that the portable gun unit is configured to be detachable from the vehicle body 9 and manually operated by the operator to reach the predetermined groove portion 92. The positioning device 3 performs spot welding.

The positioning device 3 comprises an outer guide member 7 (first guide member) and an inner guide member 8 (second guide member) which can be opened and closed via a hinge 9, and these outer guide member 7 and inner guide member 7 8 is a plate-shaped member.

The outer guide member 7 faces the groove 92 from the outside of the vehicle body 9 and is placed above the vehicle body 9 such as a roof panel, while the inner guide member 8 faces the groove 92 from the inside of the vehicle body 9. Then, it is hung down on the outer guide member 7.

As shown in FIG. 1, from both ends of the outer guide member 7 in the Y-axis direction in the figure (for example, the front-rear direction of the vehicle body), the outer guide member 7 is directed downward along the Z-axis (axis line in the vertical direction of the vehicle body) in the figure. Plate-shaped supporting members 7A and 7B are provided so as to project, and as shown in FIG.
A supporting member 7A having a hinge 9 at its tip is fixed along the X axis direction (for example, the vehicle width direction) in the figure, while a supporting member 7B is fixed along the Y axis direction.

The base end of the inner guide member 8 is swingably connected by a support member 7B via a hinge 9 arranged in the X-axis direction, and the swinging inner guide member 8 has an upper surface on the tip 8A side. With this, the lower surface of the support member 7 can be brought into contact with.

A swinging member 30 swingable around the X-axis is provided below the support member 7A.
Lock nut 3 as a locking means to be screwed with the tip of 0
1, the inner guide member 8 having the tip portion 8A in contact with the lower surface of the support member 7A is selectively coupled.

Although not shown, a groove portion or the like through which the swing member 30 can be inserted from the left side of the drawing is formed in the tip portion 8A of the inner guide member 8, and the tip portion 8 is fastened with a lock nut 31 fastened.
A is connected to the support member 7A.

The lower surface of the outer guide member 7 facing the groove portion 92 is engaged with the inner peripheral side surface of the groove portion 92, and the groove portion 9 is formed.
Positioning guides 14 and 15 that come into contact with the bottom portion 92A of the second member and support the positioning device 3 are provided so as to project downward toward the workpiece. The positioning guides 14 and 15 are arranged near the both ends of the outer guide member 7 at predetermined intervals in the width direction of the groove 92, and are formed of a plate-shaped or rod-shaped member or the like.

Then, as the second welding tip, a tapered welding tip 5 provided with the plate-like portion 50 as shown in FIG. 6 is provided on the outer guide member 7 along the groove 92 of the work. In this embodiment, a plurality of welding tips 5 are provided at intervals, and three welding tips 5 are provided. The welding tips 5a, 5 and 5b are provided from the left side of FIG. 1, and the center welding tip 5 will be described. , Etc. are similarly configured.

The welding tip 5 is supported by the tip supporting portion 10 on the base end 13 side in a state where the plate portion 50 is projected toward the work through the through hole 70 formed in the outer guide member 7. The chip support portion 10 is formed of a plate-shaped member,
It is guided only in the Z-axis direction of FIG. 1 through a pair of guide pins 11 provided upright from the upper surface of the outer guide member 7, and restricts the rotation around the axis to allow the plate-shaped portion 50 of the welding tip 5 to be guided. This plate-like portion 50 is arranged parallel to the groove portion 92 so that the groove portion 92 does not contact the inner peripheral side surface of the groove portion 92.

Then, the outer guide member 7 and the chip support portion 1
An elastic member 12 is interposed between 0s, and the welding tip 5 is constantly urged in a direction away from the work while being supported so as to be able to contact and separate toward the work.

The base end 13 of the welding tip 5 is the tip support 1
First, which is slightly dislodged from 0, is attached to a portable gun unit 2A and is axially displaceable, as shown in FIG.
It can come into contact with a tip 5'as a welding tip, and the welding tip 5 is displaced toward the workpiece in accordance with the expansion and contraction of the tip 5'of the gun unit 2A.

The inner guide member 8 facing the welding tip 5 has a through hole 80 for inserting the electrode 6 provided in the arm 2B of the gun unit 2A shown in FIG. 3 and a through hole 80 toward the outer guide member 7. A cylindrical electrode guide member 20 is provided upright coaxially with the electrode guide member 20. The electrode guide member 20 is fixed coaxially with the axis of the welding tip 5.

The hole portion 21 on the inner circumference of the electrode guide portion 20 is formed so as to engage with the inserted electrode 6 and guide the electrode 6 to the back surface of the groove portion 92 facing the welding tip 5.

In the inner guide member 8 facing the welding tips 5a and 5b, electrode guide portions 20a and 20b are erected coaxially with the axes of the welding tips 5a and 5b, respectively.

On the upper surface of the outer guide member 7, a tip guide 16 for guiding the tip 5'of the gun unit 2A along the groove portion 92 is erected upright in FIG. An electrode guide 22 that guides the electrode 6 of the gun unit 2A along the groove 92 is erected downward on the lower surface of the.

With the above construction, the operation will be described.

The positioning device 3 is manually operated by an operator, and as shown in FIG. 3, after loosening the lock nut 31 to allow the inner guide member 8 to freely swing, the rear portion of the rear portion of the vehicle body 9 shown in FIG. From the window opening 93 to the roof panel 9
0 and the positioning device 3 is arranged in the groove portion 92 of the body side panel 91.

The positioning guides 14 and 15 projecting downward from the outer guide member 7 are engaged with the inner circumference of the groove 92, and the stopper 18 provided on the support portion 7B of the outer guide member 7 serves as a roof panel. The positioning device 3 is displaced along the groove 92 until it comes into contact with the end of 90.

Next, the inner guide member 8 is rotated to bring the tip 8A into contact with the support portion 7A of the outer guide member 7 from the inside of the vehicle body 9 and to connect the lock nut 31.

In this state, each welding tip 5, 5a, 5b of the outer guide member 7 supported by the outer guide member 7 has the plate-like portion 50 at the tip thereof at a predetermined position of the groove 92, for example, shown in FIG. Since the tip supporting portion 10 is positioned at the center of the groove width W as described above, the tip supporting portion 10 does not rotate around the axis of the welding tip 5 by the pair of guide pins 11 and 11, and the plate-like portion 50 does not rotate.
2 It is always arranged along the groove portion 92 without contacting the inner peripheral side surface.

Next, the operator can move the portable gun unit 2A.
First, the electrode 6 is inserted into the electrode guide member 20a on the left side of FIG. 3, and the electrode 6 is brought into contact with the back surface of the groove 92.

Then, after the tip 5'of the gun unit 2A is brought into contact with the tip support portion 10 or the base end 13 of the welding tip 5a, the tip 5'is extended and driven to support the welding tip supported by the positioning device 3. 5a is pressed toward the groove portion 92.

After that, by energizing the tip 5 ', the groove portion 92 can be indirectly spot-welded via the welding tip 5 supported by the positioning device 3,
The operator only has to insert the electrode 6 into the electrode guide member 20a and bring the tip 5'of the gun unit 2A into contact with the tip supporting portion 10, and the gun unit 2A can be roughly positioned while the narrow groove portion 92 is formed. Spot welding can be performed accurately.

After the welding with the welding tip 5a is completed, the tip 5'of the gun unit 2A is contracted and driven, the electrode 6 is pulled out from the electrode guide member 20a, and the center welding tip 5 at the next hitting point, the electrode guide The gun unit 2A is moved toward the member 20.

At the time of this movement, the tip 5'and the electrode 6 of the gun unit 2A are guided by the tip guide 16 and the electrode guide 22 of the positioning device 3 and can be easily moved along the groove 92. Even when handling the heavy gun unit 2A, the workability can be improved by preventing the tip 5'and the electrode 6 from being largely separated from the groove 92.

Then, similarly to the welding tip 5a, the gun unit 2A is operated to accurately perform spot welding sequentially through the welding tip 5 in the center and the welding tip 5b arranged on the right side of FIG. After the welding of three points is completed, the lock nut 31 is loosened, and the inner guide member 2
By rotating 2 the positioning device 3 can be easily removed.

In this way, the welding tip 5 is preliminarily positioned at a predetermined welding position only by placing the positioning device 3 in the groove portion 92 of the work, and then the electrode of the gun unit 2A is inserted into the electrode guide member 20. And then gun unit 2
If the tip 5'of A is brought into contact with the tip support member 10,
It can be performed accurately and quickly at a predetermined position of the groove 92,
The gun unit 2A is connected to the electrode guide member 20 of the positioning device 3.
By simply inserting and facing the chip support part 10 and the chip support part 10, a fine positioning operation is not required, and the narrow groove part 9 is manually provided.
It is possible to quickly perform spot welding at No. 2.

If the workpiece has the same width of the groove 92, the positioning device 3 can be used as it is.
It is possible to quickly deal with various works without the need for a setup process such as the teaching of the robot as in the conventional example.

In the above embodiment, the case where the tip is formed in a plate shape as the welding tip 5 to be arranged in the positioning device 3 is shown, but although not shown, it is a conventional hemispherical welding tip. However, the same effect as the above can be obtained.

[0049]

As described above, according to the first aspect of the invention, in positioning the gun unit, the first welding tip is brought into contact with the second welding tip or the tip supporting member after the electrode is engaged with the electrode guide member. Only by roughly positioning the gun unit, it is possible to perform spot welding on the inner circumference of the groove quickly and accurately manually even when the width of the groove is narrow.

According to a second aspect of the present invention, each of the first and second guide members is provided with a plurality of second welding tips and electrode guide members along the groove, and the tip supporting member of the second welding tip is always made of an elastic member. Since it is urged away from the work, welding can be performed sequentially while moving the gun unit along the groove, and welding at multiple points along the groove can be performed continuously without removing the positioning device from the work. This makes it possible to ensure productivity.

According to a third aspect of the present invention, the tip of the second welding tip is constituted by a plate-like portion which can be inserted into the groove inner circumference, and the tip supporting member of the first guide member is provided around the axis of the second welding tip. Since the plate-shaped part is arranged along the groove part while restricting the rotation, the plate-shaped part can reliably weld even if the width of the groove part is narrow, and the support member restricts the rotation around the axis. Since the plate-shaped second welding tip does not come into contact with the inner circumference of the groove, welding quality can be secured.

Further, the fourth invention is the first of the gun unit.
Since the welding tip and the electrode are guided along the groove by the tip guide and the electrode guide provided in the positioning device, when moving the gun unit manually,
The gun unit does not significantly shift from the groove portion, and it is possible to perform welding at a plurality of points quickly and ensure productivity.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a positioning device according to the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is a schematic cross-sectional view showing the operation.

FIG. 4 is a perspective view showing how the groove portion of the vehicle body is welded.

FIG. 5 is a cross-sectional view of a work showing how a groove is spot welded.

FIG. 6 shows a tapered welding tip, (A) is a plan view,
(B) shows a front view and (C) shows a side view.

[Explanation of symbols]

2A gun unit 3 Positioning device 5 welding tip 6 electrodes 7 Outside guide member 7A, 7B support member 8 Inner guide member 8A tip 9 hinges 10 Chip support 11 guide pins 12 Elastic member 13 base 14, 15 Positioning guide 16 Chip guide 18 stopper 20 Electrode guide member 21 hole 22 Guide 30 Swing member 31 lock nut 50 Plate-shaped part 70, 80 through holes 90 roof panel 90A, 91A step 91 Body side panel 92 groove 92A bottom

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI // B62D 65/00 B62D 65/00 A (58) Fields surveyed (Int.Cl. ⁷ , DB name) B23K 11/00 B23K 11/11 B23K 11/30

Claims (4)

(57) [Claims] 1. A gun unit provided with a groove formed by stacking plate-like works having a bent portion and a first welding tip and an electrode supported so as to be relatively displaceable in the axial direction, and sandwiching the groove, In a spot welding machine for pressing and energizing, a first guide member configured to be detachable from the work and engageable with the inner circumference of the groove portion, and attached to the first guide member, A tip support member that is displaceable toward the groove portion of the work; and a second welding tip that is fixed to the tip support member and that is supported so as to be able to come into contact with and separate from the groove portion toward a predetermined welding position; A second guide member hinged to the first guide member and capable of facing the back surface of the groove, an electrode guide member for guiding the electrode to a position facing the second welding tip, and the second guide. Select member and first guide member A positioning device for spot-welding a groove-shaped work, comprising: locking means for selectively coupling. 2. The first guide member includes a plurality of second welding tips along the groove portion, and the second guide member includes a plurality of electrode guide members corresponding to the respective second welding tips,
The spot of the groove-like work according to claim 1, wherein an elastic member for urging the second welding tip in a direction away from the work is interposed between the tip support member and the first guide member. Positioning device for welding. 3. The second welding tip comprises a plate-shaped portion whose tip can be inserted into the groove inner circumference, while the tip support member restricts rotation of the second welding tip about its axis. The positioning device for spot welding of a grooved work according to claim 1, wherein the plate-shaped part is arranged along the groove. 4. The first guide member is provided with a tip guide for guiding the first welding tip of the gun unit along the groove portion, while the second guide member is provided with the electrode of the gun unit along the groove portion. The spot welding positioning device for a grooved work according to claim 2, further comprising an electrode guide for guiding.