JPS6310219Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention melts the tip of the stud by arc heat or resistance heat between the workpiece and the stud, and then surrounds the stud tip from the outside air when press-welding it to the workpiece. This relates to porcelain tubes for stud welding (hereinafter referred to as ferrules) that are used to form ferrules.

Using a porcelain tube with grooves with approximately equal spacing on the circumference of the ferrule that is in contact with the workpiece, it is possible to attach the diameter to large structures such as buildings and bridges (hereinafter referred to as the workpiece).
If you try to horizontally weld studs with a diameter of 16 mm or more, the larger the diameter of the stud, the more molten metal will be at the tip of the stud due to arc heat or resistance heat generation, and the molten metal will be moved by gravity during melting. There is a tendency for the molten metal to flow downward, especially within a range of approximately 45 degrees to the left and right of the vertical line passing through the center of the ferrule, resulting in defects such as insufficient extra metal and undercuts above the welded part after solidification of the molten metal. occurs, making it impossible to obtain sufficient mechanical strength of the welded part.

Therefore, when horizontally welding studs with a diameter of 16 mm or more, a groove is provided only on the upper half of the circumference of the ferrule on the side that contacts the workpiece to release the gas generated during welding. A ferrule has been proposed that attempts to prevent the outflow of molten metal without providing a groove on approximately half the circumference. However, the grooves provided on the circumference of the ferrule are originally provided at approximately equal intervals on the circumference in contact with the workpiece,
It is designed to evenly release the gas generated during arcing. Therefore, if welding is performed in a horizontal position using a ferrule that has grooves only on approximately half of its circumference as described above, it is possible to prevent molten metal from flowing out from the grooves below. Since the generated gas is released only upward, the release of the gas from below is delayed and the molten metal begins to solidify, and the gas is trapped in the solidified molten metal, and the residual gas causes porosity in the welded part. Or,
Spatter may occur due to a transient increase in the internal pressure below, or the amount of pressure applied when pressing the stud with a molten tip to the workpiece may be insufficient.
The drawback was that it was difficult to obtain stable mechanical strength. Therefore, in an attempt to reduce such defects to some extent, a smaller number of grooves are provided on approximately the lower half of the circumference of the surface of the ferrule in contact with the object to be welded than the number of grooves on the upper half of the circumference, Furthermore, as previously proposed by the present applicant, a ferrule has been proposed in which the cross-sectional area of the groove on approximately the lower half of the circumference is smaller than that of the groove on approximately the upper half of the circumference. It is certain that such an improved ferrule eliminates a considerable portion of the above-mentioned drawbacks and has certain effects. However, in these improved ferrules, the sum of the cross-sectional areas of the grooves on the lower half of the circumference is considerably smaller than that of the upper grooves, so the gas generated is uniform from the grooves on the circumference. However, there remains the problem that it does not emit light.

The present invention is based on the fact that the gas generated during welding has pressure, so it has the property of releasing regardless of the direction of the groove, whereas molten metal has a property of not easily flowing out horizontally. By using this method, multiple grooves can be formed on the lower half of the circumferential surface when the ferrule is welded in a horizontal position and the multiple grooves are approximately symmetrical on the left and right. By providing a The length direction of each groove is tilted horizontally with respect to the straight line connecting the center of each groove on the inner circumferential side and the center of the porcelain tube to reduce the gravity of the molten metal and cause the molten metal to flow out due to surface tension. The present invention provides a porcelain tube for stud welding that is designed to prevent stud welding.

Embodiments of the present invention will be described below with reference to the drawings.

Figure 1 is a plan view of a typical ferrule.
FIG. 2 is a cross-sectional view taken along line A--A in FIG. FIG. In FIGS. 3 to 7, the symbol V
-V is a vertical line passing through the center O of the ferrule, H-H is a horizontal line passing through the center O of the ferrule, codes 1 to 6 are grooves provided in the lower half circumference, and codes 7 to 12 are grooves provided in the upper half circumference. These grooves 1 to 12 have the same cross-sectional area on the inner peripheral side A. Further, in these figures, B indicates the outer peripheral side. Further, symbols C ₁ to C ₁₂ are straight lines (hereinafter referred to as center lines) connecting the center O of the ferrule and the center of each groove on the inner peripheral side.

In Fig. 3, of the grooves 1 to 6 provided on the lower half circumference, the center of the inner circumferential side A of grooves 2 to 5 is provided within a range of approximately 45° left and right with respect to the vertical line V-V. a groove, the length direction D ₂ or D 5 of grooves 2 and _5;
are inclined horizontally by approximately 25° from the center line C ₂ or C ₅ , respectively. In addition, the length direction of grooves 3 and 4
D ₃ or D ₄ is approximately below the centerline C ₃ or C ₄ , respectively.
It is tilted horizontally by 45 degrees. If the length direction of the groove is set at an angle of about 60° or more with respect to the vertical line of the lower half of the circumference in this way, it is possible to prevent the molten metal from flowing out. The ferrule shown in FIG. 3 is substantially symmetrical with respect to the vertical line V-V, and the cross-sectional area of the groove on the inner peripheral side A and the cross-sectional area of the groove on the outer peripheral side B are approximately equal. By providing the grooves in this manner, the generated gas is discharged substantially uniformly from the circumference, and the gravity of the molten metal is reduced to prevent the molten metal from flowing out due to surface tension.

FIG. 4 shows a second embodiment of the ferrule of the present invention. In the embodiment shown in FIG. 3 above, the grooves 2 to 5 on the lower half of the circumference are tilted horizontally and the length of the grooves is slightly increased, making gas release slightly more difficult in the lower half of the circumference. . Therefore, as shown in FIG. 4, by increasing the number of grooves 1 to 6 provided on the lower half circumference by one more than the number of grooves 7 to 11 provided on the upper half circumference, a third Compared to the embodiment shown in the figure, the gas discharge between the upper and lower half circumferences is made more uniform.

FIG. 5 shows a third embodiment of the ferrule of the present invention, in which grooves 1 to 6 provided on the lower half circumference and grooves 7 to 12 provided on the upper half circumference are located above and below the horizontal line H-H. It is symmetrical and attempts to equalize gas release between the upper and lower halves.

FIG. 6 shows a fourth embodiment of the ferrule of the present invention, in which two grooves 1 and 6 of the grooves 7 to 12 provided in the upper half circumference and the grooves 1 and 6 provided in the lower half circumference are The grooves are the same as those shown in the figure, and the cross-sectional area of each groove on the inner circumferential side A and the cross-sectional area of each groove on the outer circumferential side B are substantially the same. However, in the grooves 2 to 5 that are inclined horizontally to prevent the molten metal from flowing out, the cross-sectional area of each groove 2 to 5 on the outer circumferential side B is set to the inner circumferential side A.
By making the cross-sectional area larger than the cross-sectional area of each groove, the gas release effect is prevented from deteriorating due to the length of these grooves being longer than the remaining grooves 6 to 12 and 1. This aims to equalize gas release between the upper and lower half circumferences. In the embodiment shown in FIG. 6, in order to prevent the deterioration of the gas release effect of the grooves on the lower half circumference, the cross-sectional area of the grooves on the inner circumference side A of the grooves 2 to 5 on the lower half circumference is Since the cross-sectional area on the inner peripheral side of the other grooves can be made smaller, the outflow of molten metal can be more effectively prevented.

FIG. 7 shows a fifth embodiment of the ferrule of the present invention, in which grooves 2 to 5 provided on the lower half of the ferrule are spirally tilted horizontally to prevent molten metal from flowing out. For easy release of gas,
The cross-sectional area of each groove on the outer peripheral side B is larger than the cross-sectional area of each groove on the inner peripheral side A. Furthermore, in this embodiment, the grooves are provided horizontally and horizontally approximately symmetrically with respect to the vertical line V-V, and also vertically and approximately symmetrically with respect to the horizontal line H-H, so that the gas is distributed approximately uniformly vertically and horizontally. A release takes place. In addition, by providing one or two protrusions on the outer periphery of the ferrule shown in FIGS. 3 to 7 with the symbol P in FIG. It is possible to automatically position the inclined groove in the downward direction. Next, an example of stud welding using the ferrule of the present invention will be described. Reference figures 1 to 3 respectively show a conventional downward ferrule having grooves uniformly on the circumference, a horizontal ferrule having only one groove on the lower half circumference, and a third ferrule of the present invention.
Using the ferrule shown in the figure, welded a stud with a diameter of 16 mm horizontally on a vertically erected mild steel plate with a thickness of 14 mm, welding current 1300 amperes, welding time 0.7
This is a photograph of a cross section of a welded part when stud welding was performed in seconds. In reference figure 1, because the conventional downward ferrule was used for welding in a horizontal position, molten metal flows out from the groove at the bottom of the ferrule, and the excess welding area above the weld is reduced. The surrounding state of the remaining hem has become uneven. Also,
During arc generation, the molten metal flows downward, so the arc length tends to fluctuate and penetration of the stud tip and the weld object tends to be uneven. Reference Figure 2 shows a case where horizontal welding is performed using a known horizontal ferrule that has only one groove on the lower half circumference, and as the molten metal does not flow out from below, excess metal is also formed in the upper part. However, because there is only one groove at the bottom, the gas generated during welding cannot be released from below in a short period of time, and the internal pressure at the bottom increases transiently.As a result, the arc In the upward direction, the tip of the stud and the object to be welded are not uniformly melted, resulting in insufficient penetration below the weld. Referring to Figure 3, when welding is performed using the ferrule of the present invention, which has approximately the same number of grooves on the lower half circumference as on the upper half circumference, the outflow of molten metal is minimal and the excess metal is surrounded. The condition is approximately uniform. Moreover, the gas generated during welding is released uniformly from the grooves on the upper and lower half circumferences in a short period of time, so the internal pressure of the ferrule does not become uneven even during transient periods, and as a result, the stud Penetration of the tip and the object to be welded is approximately uniform. In addition, the third
In the embodiment of the present invention shown in Figs. Although the case has been described in which the cross-sectional area of the inner circumferential side of the groove and the cross-sectional area of the inner circumferential side of the groove provided on the lower half circumference are approximately equal, the present invention is not limited to these embodiments. grooves are provided, and the length direction of each groove within a certain angle range on the left and right with respect to the vertical line is from the straight line connecting the center of each groove on the inner circumferential side and the center of the porcelain tube. The number of grooves provided on the upper half of the circumference and the number of grooves provided on the lower half of the circumference do not necessarily have to be the same. Moreover, the cross-sectional area of each groove on the upper half circumference and that on the lower half circumference do not necessarily have to be equal, and can be arbitrarily selected within the range that can achieve the purpose of the present invention.

As described above, even if the ferrule of the present invention is used to perform horizontal welding of large-diameter studs, the ferrule can be welded horizontally by providing multiple grooves in the lower half of the circumference of the ferrule that contacts the workpiece. , in order to sufficiently release the gas generated during welding from the lower half of the circumference, and to keep the lower half of the circumference approximately 45 mm from the left and right with respect to the vertical line passing through the center of the porcelain tube.
The length direction of each groove within the range of 1.5 mm is tilted horizontally with respect to the straight line connecting the center of each groove on the inner circumferential side and the center of the porcelain tube, reducing the gravity of the molten metal and increasing the surface tension. As a result, it is possible to prevent the molten metal from flowing out and obtain good build-up and penetration, which is of great practical benefit.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a general ferrule, Fig. 2 is a cross-sectional view taken along the line A--A in Fig. 1, and Figs. It is a figure which shows the inner peripheral surface of the side which contacts an object. V-V...The vertical line passing through the center O of the porcelain tube, H-
H...Horizontal line passing through the center O of the porcelain tube, C ₁ to C ₁₂
... Straight line connecting the center of each groove on the inner circumferential side A and the center O of the porcelain tube, C ₂ to C ₅ ... Of the grooves provided on the lower half circumference, it is inclined in the horizontal direction than the straight line C ₂ to C ₅ along the length of the groove.

Claims (1)

[Claims for Utility Model Registration] 1. A porcelain tube for stud welding having a plurality of grooves penetrating the inner and outer circumferential sides of a circumferential surface in contact with a material to be welded, wherein the porcelain tube is welded in a horizontal position. A plurality of grooves are provided on the lower half circumference of the circumferential surface, and a groove provided on the lower half circumference is provided in the direction when the plurality of grooves are horizontally symmetrical. At least the center of the inner circumferential side of the porcelain tube is approximately 45 mm to the left and right of the vertical line.
A porcelain tube for stud welding, in which the length direction of each groove within a range of 100 mm is inclined horizontally with respect to a straight line connecting the center of each groove on the inner circumferential side and the center of the porcelain tube. 2. The porcelain tube for stud welding according to claim 1, wherein the plurality of grooves provided on the circumferential surface are provided vertically and approximately symmetrically with respect to a horizontal line passing through the center of the porcelain tube. . 3. The scope of claim 1 for registration of a utility model, in which the cross-sectional area of the inner circumferential side of the groove and the cross-sectional area of the outer circumferential side of the groove are substantially the same for each of the plurality of grooves provided on the upper half circumference and the lower half circumference, or The porcelain tube for stud welding according to item 2. 4 Of the plurality of grooves provided on the upper half circumference and the lower half circumference, at least the grooves approximately on the right and left with respect to the vertical line
A porcelain tube for stud welding according to claim 1 or 2, wherein the cross-sectional area on the outer circumferential side of the groove within a range of 45 degrees is larger than the cross-sectional area on the inner circumferential side. 5. The grooves provided on the circumferential surface are such that the number of grooves provided on the upper half circumference is approximately equal to the number of grooves provided on the lower half circumference, and the grooves provided on the upper half circumference are on the inner circumferential side. The stud welding according to any one of claims 1 to 4, wherein the cross-sectional area of the groove is substantially equal to the cross-sectional area of the inner peripheral side of the groove provided in the lower half circumference. Porcelain tube. 6. The porcelain tube for stud welding according to claim 1, wherein a projection is provided on a part of the outer periphery of the porcelain tube.