JP2023074666A - Welding structure of cylinder member - Google Patents

Abstract

To provide a welding structure of a cylinder member capable of reducing repeated stress.SOLUTION: A welding structure 50 includes: a first cylinder member 11; a second cylinder member 22 including a spigot 22b inserted to the first cylinder member 11. The second cylinder member 22 includes a thin portion 22c recessed outward with respect to the spigot 22b on an inner surface of the cylinder member 22. Weld metal 30 is positioned between the first cylinder member 11 and the second cylinder member 22 and formed on an outer surface of the spigot 22b.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a welded structure for tubular members.

Various stresses are applied to the welded portion. For example, U.S. Pat. No. 6,200,000 discloses welding between a differential case and a differential ring gear. In Patent Document 1, a differential ring gear is fitted to the outer surface of the differential case. A flange is formed on the outer surface of the differential case. A groove is formed between the flange and the side surface of the differential ring gear. A space for penetration welding is formed radially inside the groove. This space is expanded radially inward to the outer surface of the differential case in order to reduce stress due to heat shrinkage associated with welding.

JP 2011-169444 A

A spigot may be used for welding the cylindrical member. The spigot is formed on the end face of one of the tubular members and has an outer diameter that is the same as or substantially the same as the inner diameter of the other tubular member. The spigot is inserted into the other tubular member and the tubular members are welded together around the spigot. When a welded structure that includes a spigot is subjected to repeated loads, the spigot increases the rigidity of the inner part of the welded structure, so that the parts of the welded structure with low stiffness, such as between the weld metal and the base metal, Excessive cyclic stress concentrations can occur at the interface.

An object of the present disclosure is to provide a tubular member welded structure capable of reducing repeated stress.

According to one aspect of the present disclosure, a tubular member welded structure includes a first tubular member and a second tubular member including a spigot inserted into the first tubular member, wherein the inner surface of the second tubular member faces the spigot. and a weld metal positioned between the first and second tubular members and formed on the outer surface of the spigot.

The first tubular member and the second tubular member may be part of a shaft for transmitting power.

The thickness between the outer surface of the second cylindrical member and the thinned portion may be equal to or greater than the thickness between the outer surface and the inner surface of the first cylindrical member.

The thinned portion and the weld metal may not overlap in the central axis direction of the first cylindrical member and the second cylindrical member.

Advantageous Effects of Invention According to the present disclosure, it is possible to provide a welded structure for tubular members that can reduce repeated stress.

1 is a side view showing part of a shaft including a welded structure according to an embodiment; FIG. FIG. 2 is an enlarged partial cross-sectional view of part A in FIG.

Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Specific dimensions, materials, numerical values, and the like shown in such embodiments are merely examples for facilitating understanding, and do not limit the present disclosure unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are given the same reference numerals to omit redundant description, and elements that are not directly related to the present disclosure are omitted from the drawings. do.

FIG. 1 is a side view showing part of a shaft 100 including a welded structure 50 according to an embodiment. Although FIG. 1 shows only one end of the shaft 100 in the central axis direction, the other end has a similar structure. Therefore, description of the other end is omitted.

In this embodiment, the welded structure 50 is applied to a rotating shaft 100 for transmitting power. Shaft 100 may be used to transmit power in various devices. In other embodiments, the weld structure 50 may be applied to joining between the end faces of two tubular members, one of which includes a spigot, in various structures. Also, for example, the weld structure 50 may be applied to a joint between the end faces of two pipes, one of which includes a spigot.

The shaft 100 includes a shaft body 10 and a fastening member 20. As shown in FIG. Fastening member 20 includes a flange 90 . Shaft 100 includes a welded structure 50 . Shaft body 10 and fastening member 20 are joined at welded structure 50 . The shaft body 10 and the fastening member 20 are concentrically joined in series. Accordingly, in the present disclosure, the central axial, radial and circumferential directions of shaft body 10, fastening member 20 and these components are simply referred to as "axial", "radial" and "circumferential", respectively. can be

FIG. 2 is an enlarged partial cross-sectional view of part A in FIG.

In the axial direction, the end of the shaft body 10 includes a first tubular member 11 . In this embodiment, the shaft body 10 has a hollow shape throughout its length in the axial direction, but in other embodiments, the central portion of the shaft body 10 may have a solid shape. .

The first cylindrical member 11 has a cylindrical shape. In other embodiments, the first tubular member 11 may have other tubular shapes, such as an elliptical tubular shape or a polygonal tubular shape. The first cylindrical member 11 includes an end face 11a in the axial direction.

The fastening member 20 includes a main body 21 and a second tubular member 22 . For example, body 21 has a generally cylindrical shape. In this embodiment, body 21 has a solid shape. However, in other embodiments, body 21 may have a hollow shape.

The second tubular member 22 is continuous with the main body 21 and is integrated with the main body 21 . The second tubular member 22 has a generally cylindrical shape. In other embodiments, the second tubular member 22 may have other tubular shapes, such as an elliptical tubular shape or a polygonal tubular shape. The second tubular member 22 includes an end surface 22a in the axial direction. An end face 22 a of the second cylindrical member 22 faces the end face 11 a of the first cylindrical member 11 . The end surfaces 11a and 22a are spaced apart from each other in the axial direction. In this embodiment, the outer diameter of the second cylindrical member 22 is the same as the outer diameter of the first cylindrical member 11 .

The second tubular member 22 includes a spigot 22b. The spigot 22b protrudes from the end surface 22a along the axial direction. For example, spigot 22b has a cylindrical shape. The spigot 22b is formed on the radially inner portion of the end surface 22a. That is, the outer diameter of spigot 22b is smaller than the outer diameter of end face 22a.

The spigot 22 b is inserted into the first cylindrical member 11 . The outer surface of the spigot 22 b has the same shape as the inner surface of the first cylindrical member 11 . The outer diameter of the spigot 22b is substantially the same as the inner diameter of the first cylindrical member 11. As shown in FIG. For example, the first cylindrical member 11 may be attached to the outer surface of the spigot 22b by shrink fitting before welding.

The welded structure 50 includes the first tubular member 11 and the second tubular member 22 described above, and the weld metal 30 .

The end surface 11a of the first tubular member 11 and the end surface 22a of the second tubular member 22 define a groove before welding. In this embodiment, the groove has a V shape, but the shape of the groove is not limited to this. The spigot 22b is used as a backing.

Weld metal 30 is formed on the outer surface of spigot 22b. For example, welded structure 50 may be formed by electron beam welding or laser welding. However, the welding method used for welded structure 50 is not limited to these. The welded structure 50 may be provided with a toe finish.

In the welded structure 50 as described above, the inner surface of the second cylindrical member 22 includes the thinned portion 22c. The thinned portion 22c may also be referred to as a groove or notch. In the axial direction, the reduced thickness portion 22c is formed closer to the main body 21 with respect to the spigot 22b. The reduced thickness portion 22c is recessed radially outward with respect to the spigot 22b. In other words, the inner diameter of the reduced thickness portion 22c is larger than the inner diameter of the spigot 22b. In still another expression, in a cross section including the central axis X, the distance d1 from the central axis X to the thinned portion 22c is greater than the distance d2 from the central axis X to the spigot 22b. In this embodiment, the reduced thickness portion 22c is formed over the entire circumferential direction, but in other embodiments, the reduced thickness portion 22c may be may be discontinuous. The reduced thickness portion 22c is formed with a curved surface in a cross section including the central axis X in order to reduce stress concentration.

In this embodiment, the thickness t1 between the outer surface of the second cylindrical member 22 and the thinned portion 22c is equal to or greater than the thickness t2 between the outer surface and the inner surface of the first cylindrical member 11. The thickness t1 means the thickness of the thinnest portion perpendicular to the central axis X and passing through the thinned portion 22c in a cross section including the central axis X. In FIG. 2, the thickness t1 corresponds to the thickness of a portion that is perpendicular to the central axis X and passes through the radially outermost portion of the reduced thickness portion 22c in a cross section that includes the central axis X. As shown in FIG. In other words, the distance d1 from the central axis X to the reduced thickness portion 22c is less than or equal to the distance d3 from the central axis X to the inner surface of the first cylindrical member 11. More specifically, thickness t1 may be the same as thickness t2. Alternatively expressed, distance d1 may be the same as distance d3.

In the present embodiment, the thinned portion 22c does not overlap the weld metal 30 in the axial direction. More specifically, the reduced thickness portion 22c and the weld metal 30 may be separated from each other in the axial direction, and may have a gap g therebetween.

The thickness of the base material of the second cylindrical member 22 between the weld metal 30 and the thinned portion 22c, that is, between the end face 22a and the thinned portion 22c is determined by factors such as the thickness t1 and the gap g. The thickness of the base material between the end surface 22a and the reduced thickness portion 22c, including the thickness t1 and the gap g, is such that, for example, when the first cylindrical member 11 is attached to the outer surface of the spigot 22b by shrink fitting, this portion can be determined such that the stress applied to does not exceed the yield stress of the base material on all sides. Such stress can be calculated by, for example, FEM analysis.

The size of the thinned portion 22c, such as the width in the axial direction and the curvature of the curved surface, is such that, for example, repeated stress assumed to be applied to the welded structure 50 when the shaft 100 is used after welding exceeds the fatigue limit of the base material. You can decide not to. Such stress can also be calculated by, for example, FEM analysis.

The welded structure 50 as described above is the first tubular member 11 and the second tubular member 22 including the spigot 22b inserted into the first tubular member 11. The inner surface of the second tubular member 22 is the spigot 22b. A second cylindrical member 22 including a thinned portion 22c recessed outwardly with respect to the second cylindrical member 22, located between the first cylindrical member 11 and the second cylindrical member 22, and formed on the outer surface of the spigot 22b a weld metal 30; According to such a configuration, a thinned portion 22c recessed with respect to the spigot 22b is formed on the inner surface of the second cylindrical member 22 away from the interface between the weld metal 30 and the base material. Therefore, when a repeated load is applied to the welded structure 50, the load can be absorbed by the elastic deformation of the thinned portion 22c. Therefore, the stress applied to the portion having low rigidity in the welded structure 50, such as the interface between the weld metal 30 and the base material, can be reduced. Therefore, repeated stress can be reduced.

Further, in the welded structure 50, the first tubular member 11 and the second tubular member 22 are part of the rotating shaft 100 for transmitting power. Therefore, it is possible to improve the fatigue strength of the shaft 100 exposed to repeated loads associated with rotation.

In addition, in the welded structure 50, the thickness t1 between the outer surface of the second cylindrical member 22 and the thinned portion 22c is equal to or greater than the thickness t2 between the outer surface and the inner surface of the first cylindrical member 11. According to such a configuration, it is possible to maintain the rigidity of the welded structure 50 as a whole while absorbing the load in the thinned portion 22c.

Moreover, in the welded structure 50, the thinned portion 22c and the weld metal 30 do not overlap in the axial direction. Therefore, the influence on the interface between the weld metal 30 and the base metal caused by the elastic deformation of the reduced thickness portion 22c can be reduced.

Although the embodiments have been described above with reference to the accompanying drawings, the present disclosure is not limited to the above embodiments. It is clear that a person skilled in the art can conceive of various modifications or modifications within the scope of the claims, and it is understood that these also belong to the technical scope of the present disclosure. be done.

For example, in the above embodiment, the thickness t1 between the outer surface of the second cylindrical member 22 and the reduced thickness portion 22c is equal to or greater than the thickness t2 between the outer surface and the inner surface of the first cylindrical member 11. However, in other embodiments, thickness t1 may be less than thickness t2 as long as the required level of stiffness of the overall welded structure 50 can be maintained.

Further, in the above-described embodiment, the thinned portion 22c does not overlap the weld metal 30 in the axial direction. However, in other embodiments, the thinned portion 22c may overlap the weld metal 30 in the axial direction as long as the base material between the end surface 22a and the thinned portion 22c does not yield entirely.

REFERENCE SIGNS LIST 11 first tubular member 22 second tubular member 22b spigot 22c thinned portion 30 weld metal 50 welded structure 100 shaft t1 thickness between the outer surface of the second tubular member and the thinned portion t2 outer surface and inner surface of the first tubular member thickness between

Claims (4)

a first cylindrical member;
a second tubular member including a spigot inserted into the first tubular member, wherein the inner surface of the second tubular member includes a thinned portion recessed outward with respect to the spigot;
a weld metal positioned between the first cylindrical member and the second cylindrical member and formed on the outer surface of the spigot;
A welded structure of a tubular member, comprising: The welded structure of the tubular member according to claim 1, wherein the first tubular member and the second tubular member are part of a shaft for transmitting power. 3. The tubular member according to claim 1, wherein the thickness between the outer surface of the second tubular member and the reduced thickness portion is equal to or greater than the thickness between the outer surface and the inner surface of the first tubular member. Welded construction. The welded structure of the cylindrical member according to any one of claims 1 to 3, wherein the reduced thickness portion and the weld metal do not overlap in the central axis direction of the first cylindrical member and the second cylindrical member.

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