JPS6045989B2 - stud welding gun - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises movably attaching a shaft provided with a stud holder to a stud welding gun body, lifting the stud attached to the stud holder from a position pressed against a workpiece by an electromagnet, This invention relates to an improvement in a stud welding gun that generates an arc between a workpiece and a stud and then presses the stud against the workpiece after an appropriate period of time to perform welding.

Conventionally, in this type of stud welding gun, as shown in Japanese Utility Model Publication No. 42-17708, a stopper fitting whose position can be adjusted in the axial direction is provided on one side of the electromagnet, and a shaft with a stud holder is attached. When the stud is pulled up using an electromagnet, the end of the shaft is brought into contact with a stopper fitting to regulate the lifting position of the stud.

In this case, the lifting distance of the stud was measured by reading the scale provided on the stopper fitting. In this stud welding gun, the end of the shaft on which the stud holder is attached must come into contact with the stopper fitting once for each weld, and it is normal for welding to be repeated over 1E1 thousands of times. Therefore, the distance between the end faces of the shaft and the stopper fitting often fluctuates due to wear on the end faces of the shaft and the stopper fitting, or loosening of various parts of the welding gun. In the above-mentioned conventional device, the scale for reading the lifting distance is integrally provided with the stopper fitting and moves together with the stopper fitting, so the distance between the end face of the shaft and the end face of the stopper fitting fluctuates. Even if this cannot be confirmed and the distance between the end faces moves, welding will be performed assuming that the lifting distance of the stud is the set value. Therefore, the actual welding conditions may vary. There were cases in which it was not possible to obtain a good welding result because the set welding conditions did not match.Of course, in this type of stud welding, in addition to the above, there is also the amount of protrusion of the stud into the base metal, that is, the amount of upset. This also has an important influence on the welding result, but a stud welding gun that can easily measure the amount of pull-up and plunge-in of the stud has not yet been realized.

An object of the present invention is to provide a static welding gun that eliminates the above-mentioned conventional drawbacks. Below, embodiments of the present invention will be described in detail with reference to the drawings.
is a shaft movably attached to a cylindrical portion 200 provided in the stud welding gun body 2, and an electrical insulator 3 is attached to one end of the shaft 1.
A stud holder 4 is attached via the stud holder 4.

5 is a compression spring disposed between a flange 101 provided on the shaft 1 and a central protrusion 201 provided approximately at the center of the cylindrical portion of the stud welding gun body 2; The provided exterior core includes an electromagnetic coil 7 disposed within the exterior core 6, a lid core 8 that closes the exterior core 6, a movable core 9 that passes through holes in the exterior core 6 and the electromagnetic coil 7, and the movable core 9. A through hole is bored in the substantially axial center portion of the shaft 1 to allow the shaft 1 to move therethrough.

11 is constant in the circumferential direction; 12 is provided with scales having different intervals in the axial direction of the material supported by the stopper fitting and the reading bar.
The static welding gun according to any one of Items 1 and 7.

13. The stud according to any one of claims 1 to 12, wherein the reading bar locking device is an O-ring disposed in a hole extending in the axial direction. welding gun.

14 The reading bar locking device is attached to the reading bar.
The static welding gun according to any one of claims 1 to 12, characterized in that it is a ring.

15. The static welding gun according to claim 1, wherein the reading bar locking device comprises a spring member that presses the reading bar.

16. Claims 2, 7, 6, and 9, wherein the reading bar locking tool is a spring member disposed on the stopper metal fitting and presses the reading bar. The static welding gun according to any one of Items 1 and 11.

17. Claims 3, 5, 7, 10, or 12, characterized in that the member supported by the stopper fitting is formed of a spring member and presses the reading bar. Stat welding gun according to any one of the above.

18. The stud welding gun according to any one of claims 1 to 17, wherein a shaft for holding the stud and a movable core of the electromagnet are integrally formed.

19. The stud welding gun according to any one of claims 1 to 17, wherein the shaft for holding the stud and the movable core of the electromagnet are formed separately.

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, a shaft provided with a stud holder is movably attached to the main body of a stud welding gun, and the stud attached to the stud holder is pulled up by an electromagnet from a position pressed against a workpiece to be welded. This invention relates to an improvement in a stud welding gun that performs welding by pressing the stud against the object to be welded after an appropriate period of time after generating an arc between the object and the stud.

Conventionally, in this type of stud welding gun, as shown in Japanese Utility Model Publication No. 42-17708, a stopper fitting whose position can be adjusted in the axial direction is provided on one side of the electromagnet, and a shaft with a stud holder is attached. When the stud is pulled up using an electromagnet, the end of the shaft is brought into contact with a stopper fitting to regulate the lifting position of the stud.

In this case, the lifting distance of the stud was measured by reading the scale provided on the stopper fitting. With this stud welding gun, the end of the shaft on which the stud holder is attached must come into contact with the stopper fitting once for each weld, and welding is normally performed repeatedly (thousands of times a day). Therefore, the distance between the end faces of the shaft and the stopper fitting often fluctuates due to wear on the end faces of the shaft and the stopper fitting, or loosening of various parts of the welding gun.
However, in the above-mentioned conventional device, the scale for reading the lifting/lifting distance is integrally provided with the stopper fitting and moves together with the stopper fitting, so even if the distance between the end face of the shaft and the end face of the stopper fitting changes, Even if this cannot be confirmed and the distance between the end faces moves, welding will be performed assuming that the lifting distance of the stud a is the set value. Therefore, the actual welding conditions do not match the set welding conditions, and good welding results cannot be obtained in some cases. Of course, in this type of stud welding, in addition to the above, the amount of protrusion of the stud into the base metal side,
That is, the amount of upset also has an important influence on the welding result, but a stud welding gun that can easily measure the amount of pull-up and thrust of the stud has not yet been realized. An object of the present invention is to provide a static welding gun that eliminates the above-mentioned conventional drawbacks. Embodiments of the present invention will be described below in detail with reference to the drawings. In FIGS. 1 and 2, reference numeral 1 denotes a shaft movably mounted on a cylindrical portion 200 provided in a static welding gun body 2. A stud holder 4 is attached to one end via an electrical insulator 3.

5 is a compression spring disposed between a flange 101 provided on the shaft 1 and a central protrusion 201 provided approximately at the center of the cylindrical portion of the stud welding gun body 2; The provided exterior core includes an electromagnetic coil 7 disposed within the exterior core 6, a lid core 8 that closes the exterior core 6, a movable core 9 that passes through holes in the exterior core 6 and the electromagnetic coil 7, and the movable core 9. A through hole is bored in the substantially axial center portion of the shaft 1 to allow the shaft 1 to move therethrough.

11 is a movable iron core 9 having a constant width in the circumferential direction.
An arm protruding from the axial end of the
A claw 110 is provided at the end of the direction.

As shown in detail in FIG. 3, a disc-shaped lifting ring 12 is loosely fitted onto the shaft 1, and this lifting ring 12 is connected to a central protrusion by a compression spring 51 provided between it and the movable iron core 9. It is pressed against a seat portion 202 provided at 201 . The claw 110 is provided to engage the lifting ring 12 when the arm 11 is displaced in the X1 direction, and the claw 110 is provided to engage the lifting ring 12 when the arm 11 is displaced in the X1 direction.
2 is pressed against the central protrusion 201. When the electromagnetic coil 7 is in a non-excited state, the movable core 9 and the lifting ring 12 are oriented in the X2 direction by the compression springs 52 and 51, respectively, and the arm 11 of the movable core 9 moves toward the central protrusion 2.
01, and the lifting ring 12 is also locked by the central protrusion 201 of the stud welding gun body 2. In this case, a small distance is maintained between the claw 110 of the arm 11 and the lifting ring 12 in the X direction. Reference numeral 13 denotes a leg disposed on the side surface of the end of the stud welding gun body 2 in the X2 direction so as to be approximately parallel to the axis 1;
3 is fastened by a fastener 14 such that its position can be freely adjusted in the X direction.

15 is a stopper fitting screwed onto the lid core 8 so that the position in the X direction can be freely adjusted; 16 is a stopper fitting 15;
A reading bar having a circular cross section, for example, is disposed so as to be movable in the x direction through a substantially axial center of the reading bar 16. In the illustrated example, a scale 17 in the axial direction of the reading bar 16 is provided.

Reference numeral 18 denotes a reading bar locking tool for locking the reading bar 16 at an arbitrary position, and this locking tool is formed, for example, by an O-ring 181 disposed on the stopper fitting 15.

Note that a hole 151 is bored on the X2 direction side of the stopper fitting 15 to allow the shaft 1 to move freely in the X direction. and 19 is a stud held by the stud holder 4;
1 is the base material. Next, the operation of the above-mentioned static welding gun will be described. When the electromagnetic coil 7 is in a non-excited state, the flange 101 is pressed in the X2 direction by the compression spring 5 and the flange 101 is pressed in the X2 direction.
01 and the lower plate 203 of the stud welding gun body 2 are engaged. After attaching the stud 19 to the stud holder 4 in this state, the length of the leg 13 is adjusted by operating the fastener 14 so that the protruding length of the stud 19 becomes an appropriate value.
Next, the reading bar 16 is attached to the stopper fitting 15 so that the end of the reading bar 16 in the X2 direction comes into contact with the end of the shaft 1 in the X1 direction.
Insert into. At this time, the value indicated on the scale 17 by the end 152 of the stopper fitting 15 in the X1 direction is defined as A1. Next, when the stud 19 and the foot 13 are pressed against the base material 21,
The shaft 1 moves in the X1 direction against the force of the compression spring 5,
Therefore, the reading bar 16 that abuts the end of the shaft 1 in the X1 direction moves together with the shaft 1 in the X1 direction. At this time, the end portion Fl52 of the stopper fitting in the X1 direction sets the value indicated on the scale 17 (see FIG. 4a). When the electromagnetic coil 7 is excited in this state, the movable iron core 9 is pulled up in the X1 direction until it comes into contact with the stopper fitting 15. At this time, the claw 110 moves in the X1 direction together with the movable iron core 9, but the claw 110 moves in the X1 direction.
When the claw 110 moves in the direction, the lifting ring 1
Lifting ring 1 through which the shaft 1 passes in order to incline the lifting ring 12 by contacting a part of the circumference of Lifting ring 1
The round hole 2 contacts the shaft 1, and the shaft 1 and the lifting ring 12 are connected. Therefore, when the movable iron core 9 is pulled up in the X1 direction, the pawl 110, lifting ring 12, and shaft 1 are immediately pulled up in the X1 direction together.
The reading bar 16 also moves in the X1 direction along with the axis 1. At this time, the end portion 152 in the direction of the stopper fitting is turned on at the value indicated by the scale 171 (see FIG. 1a). A welding current is passed between the stud 19 and the base metal 21, and at the moment the stud 19 is pulled up from the base metal 21, the tip of the stud throat 19 and A portion of the base material 21 is melted, and after an appropriate period of time, the electromagnetic coil 7 is placed in a non-energized state. In this way, the shaft 1 is biased in the X2 direction by the spring force of the compression spring 5, and the stud 19 is pressed against the base material 21, and at the same time the welding current is cut off, completing stud welding. Now, the protrusion distance of the stud 19 from the base material 21 is L1, and the lifting distance of the stud 19 from the base material 21! Then, L1
=1~-All. Since the relationship L2=1A3-A2l holds true, measurements of Ll and L2 can be performed reliably. 9 By the way, the appropriate welding condition values for upper and lower and L2, respectively]
-10,L0 Leg 1 relative to the stud welding gun body 2
3 and the stopper fitting 15, immediately
It is difficult to set lO,L2=L2O.

Therefore, the positioning of the legs 13 and the stopper fittings 15 with respect to the main body of the stud welding gun will be explained. In this case, first, the position of the leg 13 with respect to the stud welding gun body 2 is set by operating the fastener 14 so that the value of A2 and Al is 10 above 1A2-All. Next, when the trigger switch 22 is closed with the static welding gun body 2 sufficiently separated from the base metal 21, the electromagnetic coil 7 is automatically excited, and then,
The timer operates and the electromagnetic coil 7 is placed in a non-excited state. That is, when the electromagnetic coil 7 is excited, the shaft 1, the stud 19, and the movable core 9 are pulled up together in the X1 direction, and the movable core 9 is positioned in contact with the stopper fitting 15. In this case, upper & male 2 are L2=1A3-
A2l=I (A3-A1)-(A2-A1)I, but this value is rarely equal to L2O as described above. Therefore, is the value of L2 above the set value L? , 0, it is necessary to adjust the position of the stopper fitting 15 in the X direction with respect to the stud welding gun body 2. Now consider the case where the scale of the reading bar 16 in the initial state is A1 and the scale of the reading bar 16 when the stopper fitting 15 is moved in the X1 direction is A1'' as shown in FIGS. 4a and 4b.
In this case, the amount of movement of the stopper fitting 15 in the X1 direction, that is, the amount of adjustment, is, for example, 1? If so, the moving distance of the movable iron core 9, the stud 19, the shaft 1, and the reading bar 16 in the X1 direction after the electromagnetic coil 7 is excited will naturally be 1TnIIL larger than the initial state. Therefore, Fig. 4 a and b
As is clear from the above, the value corresponding to the value of the reading bar 161 remains unchanged before and after the movement of the stopper fitting 15. In addition, as shown in FIG. 4c, the stopper fitting 15 is
Even when A1 is changed to A1″″ by displacing the A1 in the direction, the value of A3 remains unchanged in exactly the same way. As shown in Figure 4b,
Move the stopper fitting 15 in the X1 direction to adjust A1 to A1''
In this case, the displacement of the reading bar 16 corresponding to the displacement of the shaft 1 when the electromagnetic coil 7 is energized and de-energized, that is, the total stroke of the stud 19, is denoted by 1A3-A1''l.

In the initial state, the protrusion distance LlO of the stud 19 to the base material 21 is LlO=L1=1~-All as described above.
Since it is already set to 1A3-4A1]-1A2
″-A1″l=IA3-A1″l-1A2-All=1
A3-A/upper 11 is the lifting distance of the stud 19 from the base material 21. Now, returning to FIG. 1 again, the base material 21
Consider the case where the protruding length L1 of the stud 19 and the lifting distance L of the stud 19 from the base material 21 are actual set values.

When the electromagnetic coil 7 is in a de-energized state, the lifting ring 12 and the movable core 9 out of the shaft 1, the lifting ring 12, and the movable core 9, which are formed separately, are
are the compression springs 51 and 51, respectively, as shown in FIG.
52 in the X2 direction and is positioned in contact with the seat portion 202 and the protruding portion 201). in this case,
The shaft 1 is also biased in the X2 direction by the compression spring 5, and the flange 10
1 is positioned by abutting against the lower plate 203, but after attaching the stud 19 with length e±Δe to the holder 4 of the shaft 1, when the leg 13 and the stud 19 are brought into contact with the base material 21, , the shaft 1 moves in the X1 direction, and the distance between the flange 101 of the shaft 1 and the lower plate 203 becomes L1±Δe. That is, stat 19
The protrusion length ``R'' is ±Δ' above the ``R''. When the electromagnetic coil 7 is excited in this state, the movable iron core 9, lifting ring 12, shaft 1 and stud 19 are integrated into the
It is pulled up by a distance L2 in one direction. As shown in Figs. 1 and 2, if the shaft 1 and the movable core 9 are configured separately, the protrusion length of the stud will vary if the length of the stud 19 varies, but as a welding condition, In particular, since the necessary lifting distance of the stud 19 from the base material 21 is always constant, the arc condition during welding can always be kept constant, and therefore good welding results can be obtained.

Further, if the O-ring disposed on the stopper metal fitting 15 is used as the reading bar locking device 18 as in the above embodiment, dust, debris, etc. will not enter the inside of the stud welding gun from the outside. Further, since the reading bar can be locked simply by providing an O-ring groove in the stopper fitting 15 and inserting the O-ring into this groove, assembly and processing are easy and the locking operation is reliable. Various modifications to the read bar lock 18 are conceivable.

For example, as shown in FIG. 5, the reading bar 16 is formed to have a tapered outer shape that becomes narrower from the X1 direction to the The reading bar may be locked by a spring force generated by the slit S when it engages with the metal fitting 15. In this way, the locking tool 1
Since there is no need to prepare separate parts as shown in FIG. 8, the number of parts can be reduced. Further, as shown in FIGS. 6 and 7, the reading bar locking tool 18 may be formed of a spring member that engages with the reading bar 16, and this spring member may be attached to the stopper fitting 15.

In this embodiment, an indicator 20 for reading the scale provided on the reading bar 16 is attached to the stopper fitting 15. Providing the indicator 20 in this way makes it easier to read the scale. Moreover, if the position of the indicator 20 is freely adjustable in the axial direction, the end position of the shaft 1 in the X2 direction and the stud 19 can be attached to the stud holder 4 to
The scale and indicator can be easily aligned with the position of the shaft 1 when the stud 19 is brought into contact with the indicator.
Also, as shown in Fig. 7, the stopper fitting 15 side and the reading bar 1
If scales with different intervals are provided on each of the so-called calipers, the reading par 16
The distance traveled can be measured with high accuracy. Furthermore, when the reading bar 16 and the hole into which the reading bar is fitted have a circular cross section as shown in FIG. 7, the reading bar and the hole can be easily machined using a lathe or a drill. This allows production costs to be reduced. As shown in the figure, it is also possible to arrange a spring member as a reading bar locking tool 18 inside the stopper fitting 15 so that the reading bar 16 is pressed by this spring member.

In the embodiment shown in FIG. 8, the stopper fitting 15 and the reading bar 16 are each provided with scales having different intervals in the axial direction. For example, the reading bar 16 is provided with a w-adic scale, and the stopper fitting 15 is provided with a 9-adic scale. In this case, the cross-sectional shape of the reading bar 16 is
As shown in the figure, it may be circular, or as shown in FIG. 10, it may be of a shape other than circular. FIG. 11 shows another embodiment of the present invention. In this embodiment, a guide member 23 is supported by a stopper fitting 15, and a reading bar 16 is slidable in the axial direction on this guide member. The reading bar 16 is provided with an O-ring as a reading bar locking device 18. In this case, since the guide member 23 is provided with a scale and the reading bar 16 is provided with a baseline, the scale part is worn out or debris gets caught in the scale part, compared to the case where the reading bar 16 is provided with a scale. The scale will not become difficult to read. Further, by making the reading bar 16 slide within the guide member 23 and allowing the guide member 23 to be attached to and removed from the stopper fitting 15, the reading bar 16 and the guide The member 23 can be removed from the stopper fitting 15, and there is nothing protruding from the end of the stud welding gun in the X1 direction, making it easier to perform the stud welding work. After removing the reading bar 16 and guide member 23, it is desirable to attach a cover to the end of the stud welding gun in the X1 direction in order to prevent dust, debris, etc. from entering from the outside. FIG. 12 shows still another embodiment of the present invention, in which the stopper fitting 1
A screw hole is provided in the axial center of the reading bar 16 that slides in the axial direction within the reading bar 5, and a contact member 24 made of a screw rod is inserted into this screw hole.
is screwed in.

A cover 25 is attached to the upper part of the exterior core 6, and this cover is attached when the lifting distance of the stud is not being measured to prevent dust and debris from entering the torch body. When the abutment member 24 is provided as shown in FIG. 12, the abutment member 24 can be screwed into the reading bar 16 to prevent the abutment member 24 from coming into contact with the shaft 1 when the lifting distance of the stud is not being measured. It can be done.

Furthermore, by attaching the cover 25, it is possible to prevent parts from being lost. In the above embodiment, the shaft 1 and the movable iron core 9
Although the movable core 9 is constructed as a separate body), the movable core 9 can also be integrally provided at the end of the shaft 1 as shown in FIG.

In the case of FIG. 13, the end of the movable core 9 comes into contact with the reading bar 16. With this configuration, the number of parts can be reduced and assembly can be easily completed. 14 and 15 show still another embodiment of the present invention, in which the reading bar 16 has a triangular cross section.

This reading bar is slidably fitted into a triangular hole provided in the stopper fitting 15, and a reading bar locking device 18 made of a spring or the like is arranged in a groove provided on the inner surface of the triangular hole. ing. A screw hole is provided through the axis of the reading bar 16, and a contact member 21 made of a screw rod is inserted into the screw hole.
are screwed together. Therefore, when the abutting member 24 is rotated while the lower end of the abutting member 24 is engaged with the movable iron core 9, the reading bar 16 is displaced only in the axial direction while being restrained by the stopper fitting 15. In addition, as shown in FIG. 15, the scale 17
is provided in a groove provided on one surface of the reading bar 16. As shown in FIGS. 6, 8, and 14, if a spring member is used as the reading bar locking device 18, the spring member itself will hardly wear out, so that its life can be extended.

As shown in FIGS. 10 to 15, when the reading bar 16 has a non-circular cross section, the reading bar 16 moves only in the axial direction, so that the scale position is always constant and measurement becomes easier.

In the embodiments shown in FIGS. 2, 6, 8, 13, and 14, if the reading bar 16 is attached when not measuring the lifting distance of the stud, the reading bar 16 may be accidentally Reading bar 1 along with welding when inserted in the X2 direction
6 protrudes in the X1 direction, which is dangerous.

Therefore, when the pulling distance is not to be measured, it is desirable to remove the reading bar 16 from the static welding gun body 2. In this case, if a cover is provided at the end of the stud welding gun main body 2 in the X1 direction, it is possible to prevent dust, debris, etc. from entering the interior of the stud welding gun from the outside. As shown in FIG. 14, when the abutting member 24 is screwed into a screw hole provided approximately at the axial center of the reading bar 16 formed with a non-circular cross section, the end of the shaft 1 in the X1 direction Rotate the abutting member 24 that abuts the . The reading bar can be moved and adjusted in the X direction by adjusting the position of the end of the shaft 1 in the It is easy to adjust the position of the reading bar 16 and read the scale. can be done.

As shown in FIG. 15, if the scale 17 of the reading bar 16 is provided in the groove, this scale will not come into contact with the sliding surface of the stopper fitting, so there is no possibility that the scale will wear out and become difficult to see. There is no.

Although various embodiments of the present invention have been shown above, the present invention is not limited to these embodiments, and can be modified in various ways by appropriately combining the parts of the above embodiments or replacing them with equivalent members. Variations can be made.

As described above, according to the present invention, since the reading bar can be retracted when measurement of the pulling distance is not required, unnecessary wear of various parts can be prevented.

In addition, the reading bar is locked by the stopper when no external force is applied, so when the electromagnet is not excited, when the stud is in contact with the workpiece, and when the stud is pulled up, The actual protrusion distance of the stud can be determined by reading the position of each locked reading bar. It is possible to measure the separation distance and the lifting distance of the stud, and it is also possible to actually measure each of the above distances regardless of whether welding is not performed or welding, so welding conditions can be maintained reliably and good welding results can be obtained. It has the advantage of being able to

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a main part showing an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view of a main part showing the vicinity of the support part of the reading bar in FIG. 1, and FIG. 4A to 4C are explanatory views of the operation of the embodiment of FIG. 1, FIG. 5 is a front view showing a modified example of the reading bar, and FIG. 6 is a main view showing another embodiment of the present invention. 7 is a cross-sectional view taken along the line ■-■ in FIG. 6, FIG. 8 is a cross-sectional view of main parts showing another embodiment of the present invention, and FIG. 9 is a cross-sectional view taken along the line ■-■ in FIG. 10 is a sectional view showing a modified example of the cross section taken along the line 1-2 in FIG. The figure is a cross-sectional view showing another embodiment of the present invention, FIG. 14 is a cross-sectional view of a main part showing still another embodiment of the present invention, and FIG.
It is a sectional view taken along the line XV-X■ in the figure. DESCRIPTION OF SYMBOLS 1... Shaft, 2... Stat welding gun body, 4... Stat holder, 6... Exterior core, 7... Electromagnetic coil, 9... Movable core, 15... Stopper metal fittings , 16・
...Reading bar, 17...Scale, 18...Reading bar locking tool, 19...Stat, 21...Base material, 24...
Contact member.

Claims (1)

[Claims] 1. A welding gun is provided with adjustable legs for positioning the welding gun body relative to the workpiece and an electromagnet for pulling up the stud, and a shaft that holds the stud is brought into contact with the workpiece and the stud. In a stud welding gun that is moved to a position, a pull-up position, and a welding position, a stopper metal fitting for a stud holding shaft is provided on one end side of the electromagnet so as to be adjustable in position in the axial direction of the stud welding gun. , a reading bar that passes through a substantially axial center of the stopper metal fitting and is connected to the stopper metal fitting so as to be movable in the axial direction without contacting the stopper metal fitting; and between the stopper metal fitting and the reading bar. and a reading bar locking device disposed on the stud welding gun body, and when measuring the stud lifting distance, the reading bar and the stud simultaneously resist the locking force of the reading bar locking device against the stud welding gun body. A stud welding gun characterized by being able to be pulled up. 2. The stud welding gun according to claim 1, wherein the reading bar is slidably connected to an axial hole extending substantially at the axial center of the stopper fitting. 3. The reading bar according to claim 1, wherein the reading bar is slidably connected to an axial hole extending substantially at the axial center of the member supported by the stopper fitting. Stud welding gun. 4. Claim 2, characterized in that the cross-sectional shape of the hole extending substantially at the axial center of the stopper fitting is circular.
The stud welding gun described in section. 5. The stud welding gun according to claim 3, wherein the hole extending substantially into the axis of the member supported by the stopper metal fitting has a circular cross-sectional shape. 6. The stud welding gun according to claim 2, wherein the hole extending substantially in the axial center of the stopper metal fitting has a non-circular cross-sectional shape. 7. The stud welding gun according to claim 3, characterized in that the cross-sectional shape of the hole extending approximately to the axis of the material supported by the stopper fitting is non-circular. 8. The stud welding gun according to any one of claims 1 to 7, wherein the reading bar has a scale in the axial direction. 9. The stud according to claim 2, wherein the reading bar has a base line, and the stopper fitting has a scale in the axial direction. welding gun. 10. Any one of claims 3, 5, or 7, wherein the reading bar has a base line, and the member supported by the stopper metal fitting has a scale in the axial direction. Stud welding gun described in. 11. The stud welding according to any one of claims 2, 4, and 6, characterized in that scales are provided at different intervals in the axial direction of the reading bar and the stopper fitting. gun. 12. Any one of claims 3, 5, and 7, characterized in that scales are provided at different intervals in the axial direction of the material supported by the stopper fitting and the reading bar, respectively. Stud welding gun listed in. 13. The stud according to any one of claims 1 to 12, wherein the reading bar locking device is an O-ring disposed in a hole extending in the axial direction. welding gun. 14. The stud welding gun according to any one of claims 1 to 12, wherein the reading bar locking device is an O-ring attached to the reading bar. 15. The stud welding gun according to claim 1, wherein the reading bar locking device comprises a spring member that presses the reading bar. 16. Claim 2, wherein the reading bar locking tool is a spring member disposed on the stopper fitting and presses the reading bar.
The stud welding gun according to any one of Items 7, 6, 9, or 11. 17. Claims 3, 5, 7, 10, or 12, characterized in that the member supported by the stopper fitting is formed of a spring member and presses the reading bar. The stud welding gun according to any one of the above. 18. The stud welding gun according to any one of claims 1 to 17, wherein a shaft that holds the stud and a movable core of the electromagnet are integrally formed. 19. The stud welding gun according to any one of claims 1 to 17, wherein the shaft for holding the stud and the movable core of the electromagnet are formed separately.