JPH09108832A - Welded structure and its welding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the strength of a weld zone by flitting end faces of a pair of cylindrical members to each other, and forming a second weld zone extending to an outer circumferential surface of the cylindrical members across a fully fillet welded part between the outer circumferential surfaces. SOLUTION: A pair of cylindrical members 10, 11 are press flitted to each other with a margin at an end part, and the MAG welding is achieved so that the whole circumference between an end face of the cylindrical member 10 and an outer circumferential surface of the cylindrical member 11 is deposited by a fillet welded zone 12, and a second welded zone 13 is extended between the outer circumferential surfaces of the cylindrical members 10, 11 across the fillet welded zone 12. Because the second welded zone 13 is contracted and deformed, and the diameter of a fitted part of the cylindrical member 10 is reduced, the fitted part of the cylindrical member 11 is tightened, generation of the bending moment produced between the flitted parts due to the internal pressure is suppressed, and the strength is improved. The second welded zone 13 is arranged on the symmetrical position on the circumference. The strength of the welded zone is thus improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welded structure to which internal pressure is applied, such as a body of a scroll compressor and piping, and a welding method thereof.

[0002]

2. Description of the Related Art Generally, a butt joint or a lap fillet joint is used as a welded joint of a welded structure in which cylindrical members are welded and integrated by continuous welding. FIG. 13 is a cross-sectional view showing the configuration of the body of a scroll compressor as a conventional welded structure disclosed in, for example, Japanese Patent Publication No. 6-70361. The body shown in the figure is a cylindrical center shell 1
The ends of the dish-shaped end shells 2 and 3 are fitted to the insides of both ends of the shell, and fillet welding is performed over the entire circumference between the end surfaces of the center shell 1 and the outer peripheral surfaces of the ends of the end shells 2 and 3. 4,
It is constituted by applying 5 and welding together.

Further, FIGS. 14 and 15 show Japanese Patent Laid-Open No. 17077/1989.
It is sectional drawing and the partial expanded sectional view which show the structure of the body of the scroll compressor as another conventional welding structure described in the 9th publication. In the case shown in the figure, the end face of the cylindrical center shell 7 and the end face of the dish-shaped end shell 8 are abutted with the outer peripheral projection 6a of the donut-shaped inner part 6 sandwiched therebetween, and welded over the entire circumference. And is welded together.

[0004]

Since the conventional welded structure is constructed as described above, when the center shell 1 is erected and fillet welds 4 and 5 are performed as shown in FIG. Undercut occurs when a leg having a leg length equal to or larger than the thickness of the center shell 1 on the side of the wall weld 4 and a leg portion having a leg length equal to or larger than the wall thickness of the end shell 3 on the side of the fillet weld 5 is formed. It is necessary to shorten the leg length in order to obtain the welded part, the required strength as a product cannot be obtained, and if the welding start part and the steady welding part are welded at the same target position of the welding electrode, the welding speed can be reduced. There have been problems such as poor fusion at the start of welding due to dripping of the deposited metal and undercutting at steady welding.

Further, as shown in FIGS.
When the center shell 7 and the end shell 8 are butted against each other with a pinch sandwiched in between, a welding 9 is applied to the entire circumference of the internal component 6 made of cast iron or cast steel.
When applied and welded, the welded portion and the heat affected zone become martensite and become brittle. On the other hand, when pressure is applied to the inside of the body, a moment acts in a direction that opens the outer peripheral surface of the internal component 6 and the inner peripheral surfaces of the center shell 7 and the end shell 8 with the welded portion as a fulcrum, and thus becomes brittle. There is a problem that cracks occur in the welded portion and the heat affected zone.

The present invention has been made to solve the above problems, and provides a welded structure and a welding method thereof capable of improving the strength of a welded portion and preventing the occurrence of welding defects. The purpose is to do.

[0007]

According to a first aspect of the present invention, there is provided a welded structure in which one end of a pair of cylindrical members is fitted with each other.
In a welded structure formed by welding the entire circumference between the end surface of one cylindrical member and the outer peripheral surface of the other cylindrical member by fillet welding, the fillet weld portion is crossed over the fillet weld portion and The second welded portion extending between the outer peripheral surfaces is formed.

Further, a welded structure according to a second aspect of the present invention is the welded structure according to the first aspect, wherein a plurality of second welded portions are formed at symmetrical positions on the circumference.

A welded structure according to a third aspect of the present invention is the welded structure according to the second aspect, in which the respective second welded portions are simultaneously formed.

Further, a welded structure according to a fourth aspect of the present invention is the welded structure according to the second aspect, wherein the second welded portions are formed at even positions and at symmetrical positions in two or more times. Is.

According to a fifth aspect of the present invention, there is provided a welded structure in which a solid member is fitted on the inner side of one end, and the entire circumference between the end face and the outer peripheral face of the solid member is fillet welded. The welded first cylindrical member is welded to the outside on the one end side of the first cylindrical member by welding the entire circumference between the end face and the outer peripheral surface on the one end side of the first cylindrical member by fillet welding. And a second cylindrical member that has been formed.

In the welded structure according to claim 6 of the present invention, the solid member is fitted inside the one end side, and the entire circumference between the end face and the outer peripheral surface of the solid member is the first corner. The first cylindrical member welded by meat welding and the first fillet weld portion and the outer peripheral surface of the one end which are arranged coaxially with the first cylindrical member with one end abutting the outer surface of the solid member. Or a second cylindrical member having the entire circumference between the outer peripheral surface on one end side of the first cylindrical member and the outer peripheral surface on one end welded by the second fillet welding.

According to a seventh aspect of the present invention, there is provided a method for welding a welded structure according to the sixth aspect, wherein the first fillet welding is performed by the leading electrode of the two-electrode welding method and the second electrode is performed by the trailing electrode. Fillet welding is performed.

In the welded structure according to claim 8 of the present invention, the solid member is fitted inside the one end side, and the entire circumference between the end surface and the outer peripheral surface of the solid member is the first corner. Between the first cylindrical member welded by meat welding and the outer surface of the solid member and the outer peripheral surface of the one end which are arranged coaxially with the first cylindrical member with one end abutting the outer surface of the solid member. A second fillet weld along the entire circumference of the first and second fillet welds to cover the first and second fillet welds.
And a second cylindrical member welded by performing overlay welding to reach the cylindrical member.

A welding structure welding method according to a ninth aspect of the present invention is the welding method according to the eighth aspect, wherein the first fillet welding is performed by the leading electrode of the two-electrode welding method and the second electrode is performed by the trailing electrode. Fillet welding and overlay welding are performed.

The welding method for a welded structure according to a tenth aspect of the present invention is the welding method according to the eighth aspect, wherein the first fillet welding is performed and then the second fillet is formed by the leading electrode of the two-electrode welding method. In addition to welding, overlay welding is performed with a trailing electrode.

A welding structure welding method according to an eleventh aspect of the present invention is the three-electrode welding method according to the eighth aspect, in which the first fillet welding, the second fillet welding and the overlay welding are performed in this order. Welding is performed.

A welded structure according to a twelfth aspect of the present invention is the welded structure according to any one of the first, sixth and eighth aspects, in which the linear expansion coefficient of the second fillet welded portion and the overlay welded portion of the base metal is Greater than that.

Further, a welded structure according to a thirteenth aspect of the present invention is the welded structure according to the twelfth aspect, wherein the base material is a steel material and the second fillet weld portion and the overlay weld portion are austenite phase Fe.
-Ni-based alloy.

According to a fourteenth aspect of the present invention, in the method for welding a welded structure, the electrodes of fillet welding are aimed at the corner portion at the welding start portion, and at the steady welding portion by a predetermined dimension from the corner portion. It is set at a distant position.

A welded structure according to a fifteenth aspect of the present invention is a compressor body.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. 1 is a sectional view showing a structure of a welded structure according to Embodiment 1 of the present invention, FIG. 2 is a sectional view showing a section taken along line II-II in FIG. 1, and FIG. 3 is a second welded portion at four positions. 2 is a sectional view showing a portion corresponding to FIG.
FIG. 4 is a cross-sectional view showing a portion corresponding to FIG. 2 when there are six second welded portions.

In the figure, reference numerals 10 and 11 denote a pair of cylindrical members press-fitted on each end side with an overlap margin of 30 mm. One cylindrical member 10 has an outer diameter of 120 mm and an inner diameter of 110 mm.
A pipe made of hot-rolled mild steel (SPHC) having a length of 300 mm, and the other cylindrical member 11 has an outer diameter of 110 mm and an inner diameter of 100.
The pipe is made of SPHC and has a length of 300 mm and a length of 300 mm. Reference numeral 12 denotes a fillet weld portion that welds and integrates the entire circumference between the end surface of one cylindrical member 10 and the outer peripheral surface of the other cylindrical member 11, and 13 crosses the fillet weld portion 12 and both cylindrical members The second welded portion is formed by MAG welding so as to extend between the outer peripheral surfaces of 10 and 11 and is symmetrically arranged at three positions at intervals of 120 ° on the circumference.

In the welded structure of the first embodiment configured as described above, the second welded portion 13 arranged across the fillet welded portion 12 is contracted and deformed after welding, and one cylindrical member 10 is formed. Since the diameter of the fitting portion of the cylindrical member 10 becomes smaller, the fitting portion of the other cylindrical member 11 is tightened by the one cylindrical member 10, so that the inner pressure of both cylindrical members 10, 1
The generation of a bending moment acting between the fitting portions of No. 1 is suppressed, and the strength of the welded portion can be improved. Also, the second welded portion 13
By arranging the two at symmetrical positions on the circumference, the deformation of both the cylindrical members 10 and 11 at the time of welding can be balanced, so that the generation of a bending moment can be further suppressed.

The second welded portion 13 is formed at the same time by using as many welding electrodes as the number of the formed portions when the number of the formed portions is odd, for example, in the above case, three welding electrodes are used. To do. On the other hand, if the number of formation points is an even number, the welding electrodes are formed at the same time by using a number corresponding to the number of formation points, or
It is formed twice or more in a range in which symmetry is maintained by a plurality of welding electrodes. That is, when it is formed at four places as shown in FIG. 3, all the second welded portions 13a to 13d are simultaneously formed by using four welding electrodes, or
The second welding portions 13a and 13c facing each other by 180 ° are simultaneously formed by using two welding electrodes, and then 13b and 13d are simultaneously formed. In addition, as shown in FIG. 4, when it is formed at six places, all the second welded portions 13a to 13f are simultaneously formed by using six welding electrodes or three welding electrodes are used. Second welds 13 located at 120 ° intervals
After forming a, 13c and 13e at the same time, 13b and 13
d and 13f are formed at the same time.

Embodiment 2 FIG. In addition, the linear expansion coefficient of the second welded portion 13 in the second embodiment is set to be larger than the linear expansion coefficient of the base material, that is, both the cylindrical members 10 and 11.
For example, as in the first embodiment, both cylindrical members 10,
When 11 is a SPHC pipe, when it is formed by using a Ni-based welding wire while controlling its addition amount, it becomes an austenite phase of the Fe—Ni-based alloy, and the linear expansion coefficient of both cylindrical members 10 and 11 is the same. Since the coefficient of linear expansion is larger than the coefficient of expansion and the tightening effect due to shrinkage deformation after welding is further increased, it is possible to further suppress the occurrence of bending moment.

Embodiment 3 5 is a sectional view showing a structure of a welded structure according to a third embodiment of the present invention. In the figure, 14 and 15 are a pair of cylindrical members press-fitted at one end side with an overlap margin of 30 mm.
4 has an outer diameter of 110 mm, an inner diameter of 100 mm, and a length of 300 mm
Of hot-rolled mild steel (SPHC), the other cylindrical member 15 has an outer diameter of 120 mm, an inner diameter of 110 mm, and a length of 30.
Each is formed of a 0 mm SPHC pipe. Reference numeral 16 is a solid member that is press-fitted into the inner side of one end side of one cylindrical member 14 with a stacking margin of 30 mm and has an outer diameter of 100 m.
It is formed of an FC25 disc having a thickness of 35 mm and a thickness of 35 mm.
This corresponds to the conventional internal component 6 shown in FIG. Reference numeral 17 denotes a fillet weld portion that welds and integrates the entire circumference between the end surface of one cylindrical member 14 and the outer peripheral surface of the solid member 16, and 18 denotes an outer peripheral surface of one cylindrical member 14 and the other cylindrical member. It is a fillet welded portion which is welded and integrated with the entire circumference between the end surface of 15 and the end surface.

In the welded structure according to the third embodiment having the above-described structure, the fillet weld portion formed over the entire circumference between the outer peripheral surface of one cylindrical member 14 and the end surface of the other cylindrical member 15. Since 18 suppresses the generation of a bending moment due to the internal pressure due to the tightening force that shrinks and deforms after welding, even if the heat-affected zone of the fillet welded portion 18 becomes martensite and becomes brittle, it becomes difficult to crack and the strength of the welded portion is increased. Can be improved. In the third embodiment, as in the second embodiment, the Ni-based wire is used for welding while controlling the dilution ratio.
It goes without saying that when the austenite phase fillet weld 18 of the Ni-based alloy is formed, the linear expansion coefficient becomes larger than that of both the cylindrical members 14 and 15, and the tightening effect is increased.

Embodiment 4 FIG. 6 is a diagram showing steps of a welding method for a welded structure according to Embodiment 4 of the present invention, and FIG. 7 is a sectional view showing details of a welded portion of the welded structure in FIG. In the figure, 19 is an outer diameter of 110 mm and an inner diameter of 1
One cylindrical member made of SPHC pipe of 00 mm and 300 mm in length, 20 is another cylindrical member made of SPHC pipe of 90 mm in outer diameter, 80 mm in inner diameter and 300 mm in length, 21 is FC25 having outer diameter of 100 mm and thickness of 20 mm It is a solid member made of a disc and has a concave portion 21a having an inner diameter of 90 mm and a depth of 25 mm formed on one surface.

Next, a method for welding a welded structure in the fourth embodiment will be described with reference to FIG. First, as shown in FIG. 6A, one cylindrical member 19 and the solid member 2
1 and the other cylindrical member 20 are arranged in this order, and then FIG.
As shown in (b), the solid member 21 is replaced by the one cylindrical member 19
While being press-fitted into the inside of the above with a stacking margin of 15 mm, one end of the other cylindrical member 20 is press-fitted into the recess 21a of the solid member 21. Then, as shown in FIG. 6C, one cylindrical member 1
9 along the entire circumference between the end surface of 9 and the outer peripheral surface of the solid member 21.
After forming the first fillet weld portion 22 by G welding, as shown in FIG. 6D, between the first fillet weld portion 22 and the outer peripheral surface of the other cylindrical member 20, or the first fillet weld portion 22. The fillet welded portion 22 is covered and MAG welding is performed over the entire circumference between the outer peripheral surfaces of both the cylindrical members 19 and 20, and a second fillet welded portion 23 is formed to integrate the welded structure.

The welding conditions are the first fillet welded portion 2
When forming 2, arc voltage 25V, welding current 25
0 A, welding speed 80 cm / min, when forming the second fillet weld 23, arc voltage 30 V, welding current 3
00A, welding speed 80 cm / min, Ar gas containing 20% CO ₂ was used as a shield gas, and 15 l / m
Supply in weld quantity in in. A Ni-based wire with a diameter of 1.2 mm is used as the welding wire.

In the welded structure according to the fourth embodiment constituted by the above-described welding method, the first fillet welded portion 2 is formed.
2 is formed, and then between the first fillet weld 22 and the outer peripheral surface of the other cylindrical member 20, or the first fillet weld 2
Since the second fillet welded portion 23 is formed on the entire circumference between the outer peripheral surfaces of both the cylindrical members 19 and 20 by covering the 2, the post-heat effect at the time of forming the second fillet welded portion 23 , Heat-affected zone 24 generated during formation of first fillet weld 22
Is suppressed to be martensite and becomes brittle, and the residual stress of the heat-affected zone 24 is compressed by the tightening force due to the contracting deformation of both the cylindrical members 19 and 20, so that cracks are less likely to occur and the weld zone It is possible to improve the strength of the.

If a two-electrode welding method is applied to form the first fillet weld portion 22 with the leading electrode and the second fillet weld portion 23 with the trailing electrode, a single electrode is formed. It is also possible to improve productivity as compared with the case of welding with.

Embodiment 5. FIG. 8 is a diagram showing steps of a method for welding a welded structure in a fifth embodiment of the present invention, and FIG. 9 is a sectional view showing details of a welded portion of the welded structure in FIG. In the figure, 25 is an outer diameter of 110 mm and an inner diameter of 1
One cylindrical member made of SPHC pipe of 00 mm and length of 300 mm, 26 is another cylindrical member made of SPHC pipe of 90 mm outer diameter, 80 mm of inner diameter and 300 mm length, 27 is FC25 having outer diameter of 100 mm and thickness of 20 mm. It is a solid member made of a circular plate.

Next, a welding method of the welded structure in the fifth embodiment will be described with reference to FIG. First, as shown in FIG. 8A, one cylindrical member 25, the solid member 2
7 and the other cylindrical member 26 in this order, and then FIG.
As shown in (b), the solid member 27 is replaced by the one cylindrical member 25.
While being press-fitted into the inside of the cylinder with a stacking margin of 15 mm, the end surface of the other cylindrical member 26 is brought into contact with the outer surface of the solid member 27. Then, as shown in FIG. 8C, a second fillet weld 28 is formed by MAG welding on the entire circumference between the end surface of the other cylindrical member 26 and the outer surface of the solid member 27.

Next, as shown in FIG. 8 (d), a first fillet weld 29 is formed by MAG welding on the entire circumference between the end surface of the one cylindrical member 26 and the outer peripheral surface of the solid member 27. Form. The welding conditions for forming both fillet welds 28 and 29 were an arc voltage of 25 V, a welding current of 250 A, and a welding speed of 80 cm / min, and a shield gas of 20%.
Using Ar gas containing CO _2, it is supplied to the welded portion at a rate of 15 l / min. A Ni-based wire with a diameter of 1.2 mm is used as the welding wire.

Finally, as shown in FIG. 8 (e), a weld overlay 30 is formed by MAG welding so as to cover both fillet welds 28 and 29. In addition, this overlay welding part 3
The welding conditions for forming 0 are an arc voltage of 32 V, a welding current of 350 A, and a welding speed of 80 cm / min. The shielding gas is 15 l using 20% CO ₂ -containing Ar gas.
/ Min to the weld. A Ni-based wire with a diameter of 1.2 mm is used as the welding wire.

In the welded structure in the fifth embodiment constituted by the welding method as described above, between the one cylindrical member 25 and the solid member 27 and between the solid member 27 and the other cylindrical member 26. Both fillet welds 28 and 29 are formed between them, and both fillet welds 28 and 29 are formed.
Since the build-up welded portion 30 reaching both the cylindrical members 25 and 26 is formed so as to cover the cylindrical members 25 and 26, the heat-affected zone 31 generated when the fillet welded portions 28 and 29 are formed is martensitic and brittle. Nevertheless, since the residual stress of the heat-affected zone 31 becomes a compressive stress due to the tightening force due to the shrinkage deformation of the overlay welded portion 30, cracks are less likely to occur and the strength of the welded portion can be improved. become.

The two-electrode welding method is applied to form the first fillet welded portion 28 at the leading electrode and the second fillet welded portion 29 and the buildup welded portion 30 at the trailing electrode. Alternatively, after forming the first fillet welded portion 28, the second fillet welded portion 29 is formed by the preceding electrode of the two-electrode welding method.
It is also possible to form the build-up welded portion 30 with the trailing electrode, and further, by applying the three-electrode welding method, the first fillet welded portion 29 and the second fillet welded portion 29. Part 2
8 and the overlay welding portion 30 may be formed in this order. By doing so, it is possible to improve productivity as compared with the case of welding with a single electrode.

Sixth Embodiment FIG. 10 is a diagram showing target positions of electrodes in a welding method for a welded structure according to a sixth embodiment of the present invention. Hereinafter, a sixth embodiment will be described with reference to FIG.
The welding method of the welded structure in 1 is described. First, outer diameter 110 mm, inner diameter 100 mm, length 300 mm
One cylindrical member 32 made of SPHC pipe, and SPHC having an outer diameter of 100 mm, an inner diameter of 90 mm and a length of 300 mm
The other cylindrical member 33 made of a pipe is prepared, and one end of the other cylindrical member 33 is press-fitted into the inside of the one cylindrical member 32 with an overlap margin of 15 mm.

Then, as shown in FIG. 10A, the welding electrode 34 is aimed at a corner portion (shown by A in the figure) where the outer peripheral surface of the one cylindrical member 32 and the end surface of the other cylindrical member 33 are in contact with each other. Position and start welding. Next, welding speed 80 cm /
The welding electrode 34 is moved in the circumferential direction for min, and the welding length is 40 mm from the corner A, and the position B is 1 mm away from the corner A at an electrode speed of 1 mm / sec as shown in FIG. 10B. Then, fillet welding is performed along the entire position B along the entire circumference. The welding conditions at this time are
Arc voltage is 25V, welding current is 250A, Ar gas containing 20% CO ₂ is used as a shield gas, and 15 l / m is used.
Supply to the weld zone in. The diameter of the welding wire is 1.
A 2 mm Ni-based wire is used.

In the welding method of the welded structure according to the sixth embodiment performed as described above, the target position of the welding electrode 34 is the corner A at the welding start portion and the corner A at the steady welding portion.
Since, for example, the welding is performed at a position B on the other cylindrical member 33 side, which is 1 mm away from the other by a predetermined dimension, the welding progresses to some extent and the temperature of both cylindrical members 32 and 33 rises due to the heat storage effect. However, since the melting amount of the one inner cylindrical member 32 is appropriately maintained, undercut or the like does not occur and it is possible to prevent the occurrence of welding defects. In addition, although the case where both the cylindrical members 32 and 33 are arranged in the vertical direction to perform welding has been described in the sixth embodiment, the same effect is exhibited also in the case where the cylindrical members 32 and 33 are arranged in the horizontal direction and welding is performed. Not to mention getting it.

Embodiment 7 FIG. FIG. 11 is a diagram showing steps of a welding method for a welded structure in a seventh embodiment of the present invention,
FIG. 12 is a perspective view showing the configuration of a stylus used for welding the welded structure in FIG. Hereinafter, a method for welding a welded structure according to the seventh embodiment will be described with reference to FIG. First, a first cylindrical member 35 made of SPHC pipe having an outer diameter of 120 mm, an inner diameter of 110 mm, and a length of 300 mm, and a second cylindrical member of SPHC made of an outer diameter of 110 mm, an inner diameter of 100 mm and the other end side closed in a hemispherical shape. The cylindrical member 36 is prepared.

Then, as shown in FIG. 11A, one end side of the second cylindrical member 36 is press-fitted into the inside of the first cylindrical member 35 with an overlap margin of 30 mm. Next, the first cylindrical member 35
Using one end face (indicated by A in the figure) as a reference, a stylus 37 having a radiused surface 37a with a radius of 2 mm at the tip as shown in FIG. 12 is used, and as shown in FIG. The distance l to the other end surface (shown by B in the figure) of the cylindrical member 35, that is, the position where the fillet welded portion 38 is formed is measured.

Here, a method for measuring the distance 1 by the stylus 37 will be described in detail. First, as shown in FIG. 11 (b), the stylus 37 has a rounded surface 37 a with the second cylindrical member 3
6 is set so as to contact the hemispherical portion of the first cylindrical member 6, and then is moved in the axial direction of the first cylindrical member 35, and at the same time, is moved outward in the radial direction. To the other end surface B of. Then, depending on the distance from the initially set position of the stylus 37 to the contact with the other end surface B, the distance 1 between the both end surfaces A and B of the first cylindrical member 35, that is, the fillet welded portion 38. The position forming the is determined.

However, since the distance l varies, only those within a predetermined range centering on a preset reference value L are extracted. Next, the welding electrode 39 is moved from the reference position as shown in FIG. 11C by an amount corresponding to the difference between the reference value L and the measured value l, and
As shown in (d), a fillet weld portion 38 is formed by the MAG welding method. The welding conditions at this time were as follows: arc voltage 25 V, welding current 250 A, welding speed 80 cm / mi.
n, and Ar gas containing 20% CO ₂ is used as the shield gas and is supplied to the welded portion at 15 l / min. A Ni-based wire with a diameter of 1.2 mm is used as the welding wire.

In the welding method of the welded structure according to the seventh embodiment as described above, the fillet welded portion 3 is formed by using the stylus 37.
8 is measured and the target position of the welding electrode 39 is determined based on the measured result to perform welding. Therefore, even if a member having poor shape accuracy is welded at high speed, no welding defect occurs. It is possible to obtain a good weld,
Further, since the rounded surface 37a is formed at the tip of the stylus 37, the movement becomes smooth even on a surface having a complicated shape, so that the position of one end surface B of the first cylindrical member 35 can be reliably measured. it can.

Embodiment 8. In each of the above embodiments, the case where SPHC is used for the cylindrical member has been described, but it is also possible to use other steel materials, aluminum alloys, and copper alloys, and the MAG welding method for forming the welded portion. However, it goes without saying that various welding methods such as TIG welding method, plasma welding method and laser welding method can be applied. Furthermore, if the welded structure in each of the above-described embodiments is applied to the body of a compressor such as a scroll compressor, it is possible to provide a compressor with better performance.

[0049]

As described above, according to claim 1 of the present invention, one end of a pair of cylindrical members is fitted to each other, and the end surface of one cylindrical member and the outer peripheral surface of the other cylindrical member are fitted together. In a welded structure formed by welding the entire circumference by fillet welding, a second welded portion that extends between the outer peripheral surfaces of both cylindrical members is formed at the fillet welded portion, so that the welded portion of the welded portion is formed. It is possible to provide a welded structure capable of further improving strength.

According to the second aspect of the present invention, in the first aspect, the second welded portions are formed at a plurality of symmetrical positions on the circumference, so that the strength of the welded portions can be further improved. It is possible to provide a welded structure capable of

Further, according to claim 3 of the present invention, in claim 2, since each second welded portion is formed at the same time, a welded structure capable of further improving the strength of the welded portion is provided. can do.

According to the fourth aspect of the present invention, in the second aspect, the second welded portions are formed at even positions and at symmetrical positions in two or more times. Therefore, the welded portions are simultaneously formed. It is possible to provide a welded structure capable of further improving the strength of the welding structure.

According to the fifth aspect of the present invention, the solid member is fitted inside the one end side, and the entire circumference between the end face and the outer peripheral surface of the solid member is welded by fillet welding. A first cylindrical member and a first cylindrical member fitted to the outside on one end side and welded by fillet welding over the entire circumference between the end surface and the outer peripheral surface on the one end side of the first cylindrical member. Since it has two cylindrical members,
A welded structure capable of improving the strength of a welded portion can be provided.

According to the sixth aspect of the present invention, the solid member is fitted inside the one end side, and the entire circumference between the end face and the outer peripheral face of the solid member is welded by the first fillet welding. Between the welded first cylindrical member and the first fillet weld and the outer peripheral surface of the one end, which is arranged coaxially with the first cylindrical member with one end abutting the outer surface of the solid member, or Since the entire circumference between the outer peripheral surface on the one end side of the first cylindrical member and the outer peripheral surface on the one end is provided with the second cylindrical member welded by the second fillet welding, the strength of the welded portion is improved. A welded structure capable of achieving the above can be provided.

According to claim 7 of the present invention, in claim 6, the first fillet welding is performed by the leading electrode of the two-electrode welding method and the second fillet welding is performed by the trailing electrode. As a result, it is possible to provide a welding method for a welded structure capable of improving not only the strength of the welded portion but also the productivity.

According to the eighth aspect of the present invention, the solid member is fitted inside the one end side, and the entire circumference between the end surface and the outer peripheral surface of the solid member is subjected to the first fillet welding. The welded first cylindrical member and the entire circumference between the outer surface of the solid member and the outer peripheral surface of the one end arranged coaxially with the first cylindrical member with one end abutting the outer surface of the solid member. A second cylindrical member welded by performing a second fillet welding and overlaying welding to reach the first cylindrical member by covering the first and second fillet welds. It is possible to provide a welded structure capable of improving the strength of the welded portion.

According to a ninth aspect of the present invention, in the eighth aspect, the first fillet welding is performed with the leading electrode of the two-electrode welding method, and the second fillet welding and the meat are performed with the trailing electrode. Since the weld welding is performed, it is possible to provide a welding method for a welded structure, which can improve not only the strength of the welded portion but also the productivity.

According to a tenth aspect of the present invention, in the eighth aspect, after the first fillet welding is performed, the second fillet welding is performed with the leading electrode of the two-electrode welding method and the trailing welding is performed. Since the overlay welding is performed using the electrodes, it is possible to provide a welding method for a welded structure that can improve not only the strength of the welded portion but also the productivity.

According to the eleventh aspect of the present invention, in the eighth aspect, the first fillet welding, the second fillet welding and the overlay welding are performed in this order by the three-electrode welding method. Therefore, it is possible to provide a welding method for a welded structure capable of improving not only the strength of the welded portion but also the productivity.

According to a twelfth aspect of the present invention, in any one of the first, sixth and eighth aspects, the linear expansion coefficient of the second fillet weld portion and the overlay weld portion is set to be larger than that of the base metal. Since the size is increased, it is possible to provide a welded structure capable of further improving the strength of the welded portion.

According to the thirteenth aspect of the present invention, in the twelfth aspect, the base material is a steel material, and the second fillet weld portion and the overlay weld portion are Fe-Ni type alloys of austenite phase. It is possible to provide a welded structure capable of further improving the strength of the welded portion.

According to the fourteenth aspect of the present invention, the aim of the fillet welding electrode is set at the corner portion at the welding start portion and at the position apart from the corner portion by a predetermined dimension at the steady welding portion. Therefore, it is possible to provide a method for welding a welded structure capable of preventing the occurrence of welding defects.

According to the fifteenth aspect of the present invention, by applying the welded structure to the body of the compressor, it is possible to provide a compressor having excellent performance.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a structure of a welded structure according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a section taken along line II-II in FIG.

FIG. 3 is a cross-sectional view showing a portion corresponding to FIG. 2 when there are four second welded portions.

FIG. 4 is a cross-sectional view showing a portion corresponding to FIG. 2 when there are six second welded portions.

FIG. 5 is a sectional view showing a structure of a welded structure according to a third embodiment of the present invention.

FIG. 6 is a diagram showing steps of a welding method for a welded structure in a fourth embodiment of the present invention.

7 is a cross-sectional view showing details of a welded portion of the welded structure in FIG.

FIG. 8 is a diagram showing steps of a welding method for a welded structure in a fifth embodiment of the present invention.

9 is a cross-sectional view showing details of a welded portion of the welded structure in FIG.

FIG. 10 is a diagram showing target positions of electrodes in a welding method for a welded structure according to a sixth embodiment of the present invention.

FIG. 11 is a diagram showing steps of a method for welding a welded structure in a seventh embodiment of the present invention.

12 is a perspective view showing a configuration of a stylus used for welding the welded structure in FIG.

FIG. 13 is a cross-sectional view showing a configuration of a body of a scroll compressor as a conventional welded structure.

FIG. 14 is a cross-sectional view showing the structure of the body of a scroll compressor as another conventional welded structure.

15 is a partially enlarged cross-sectional view showing details of a welded portion in FIG.

[Explanation of symbols]

10, 11, 14, 15, 19, 20, 25, 26, 3
2, 33 Cylindrical member, 12, 17, 18, 38 Fillet weld, 13, 13a to 13f Second weld, 16,
21, 27 Solid member, 21a Recess, 22, 29 First fillet weld, 23, 28 Second fillet weld,
24,31 Heat-affected zone, 30 Overlay weld, 34,39
Welding electrode, 35 First cylindrical member, 36 Second cylindrical member, 37 Stylus, 37a R-face.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B23K 9/127 501 501-315E B23K 9/127 501C 9/173 9/173 E 9/23 9 / 23 A 33/00 33/00 A F04C 18/02 311 F04C 18/02 311B 29/00 29/00 B (72) Inventor Hiroyuki Fujiwara 2-3-3 Marunouchi, Chiyoda-ku, Tokyo Sanryo Denki Co., Ltd.

Claims (15)

[Claims] 1. A welded structure in which one ends of a pair of cylindrical members are fitted to each other and the entire circumference between the end surface of one cylindrical member and the outer peripheral surface of the other cylindrical member is welded by fillet welding. ,
A second welded portion is formed in the fillet welded portion so as to cross the fillet welded portion and extend between the outer peripheral surfaces of the cylindrical members. 2. The welded structure according to claim 1, wherein a plurality of second welded portions are formed at symmetrical positions on the circumference. 3. The welded structure according to claim 2, wherein each of the second welded portions is formed at the same time. 4. The welded structure according to claim 2, wherein the second welded portions are formed at even positions and at symmetrical positions divided at least twice. 5. A first cylindrical member, wherein a solid member is fitted on the inner side of one end side, and the entire circumference between the end face and the outer peripheral surface of the solid member is welded by fillet welding. A second cylindrical member fitted to the outer side of one end of the first cylindrical member and welded by fillet welding over the entire circumference between the end face and the outer peripheral surface of the first cylindrical member on the one end side. Welded structure characterized by 6. A first cylindrical member, wherein a solid member is fitted inside one end side, and the entire circumference between the end face and the outer peripheral surface of the solid member is welded by a first fillet welding. , One end is in contact with the outer surface of the solid member and is disposed coaxially with the first cylindrical member, and is between the first fillet weld and the outer peripheral surface of the one end, or the first cylinder. A welded structure comprising: a second cylindrical member having an outer circumference on one end side of the member and an entire circumference between the outer circumference on the one end side welded by a second fillet weld. 7. The welding of a welded structure according to claim 6, wherein the first fillet welding is performed by the leading electrode of the two-electrode welding method and the second fillet welding is performed by the trailing electrode. Method. 8. A first cylindrical member, wherein a solid member is fitted inside one end side, and the entire circumference between the end face and the outer peripheral surface of the solid member is welded by a first fillet welding. , One end is in contact with the outer surface of the solid member and is arranged coaxially with the first cylindrical member, and the entire circumference between the outer surface of the solid member and the outer peripheral surface of the one end is the second corner. A second cylindrical member that is welded by performing a meat welding and performing a build-up welding that covers the first and second fillet welds and reaches the first cylindrical member. Welded structure. 9. The welding according to claim 8, wherein the first fillet welding is performed by the leading electrode of the two-electrode welding method, and the second fillet welding and the overlay welding are performed by the trailing electrode. Welding method for structures. 10. The method according to claim 8, wherein after the first fillet welding, the second fillet welding is performed by the leading electrode of the two-electrode welding method and the overlay welding is performed by the trailing electrode. Welding method of the welded structure described. 11. The method for welding a welded structure according to claim 8, wherein the first fillet welding, the second fillet welding, and the overlay welding are performed in this order by a three-electrode welding method. 12. The welding according to claim 1, wherein the second fillet weld and the overlay weld have a coefficient of linear expansion larger than that of the base metal. Structure. 13. The welded structure according to claim 12, wherein the base material is a steel material, and the second fillet weld and the weld overlay are an austenitic Fe—Ni alloy. 14. A welding structure characterized in that an aim of an electrode for fillet welding is set at a corner portion at a welding start portion and at a position apart from the corner portion by a predetermined dimension at a steady welding portion. How to weld the body. 15. The welded structure according to any one of claims 1, 2, 3, 4, 5, 6, 8, 12, and 13, which is a body of a compressor.