JP7148782B2 - Joining structure of metal tubular members - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to a joining structure for metal tubular members.

As a conventional method for increasing the joint strength of metal tubular members, there is a joint structure described in Patent Document 1. This conventional joint structure improves the brazing strength when brazing another pipe to a stainless steel pipe. The tip of the tubular body that becomes the tube is tapered to reduce its diameter.

JP 2013-169576 A

In Patent Document 1, the brazing filler metal can be easily poured and the brazing filler metal throwing power is improved by the structure described above. It does not mention how to improve the bonding strength between them.

An object of the present disclosure is to provide a joint structure for metal tubular members in which joint strength of the metal tubular members is improved by improving joint surfaces of the metal tubular members.

According to the joining structure of metal tubular members according to the first aspect, the first metal tubular member is a joining structure of two metal tubular members, the end portion of which is arranged inside the joining structure; an outer peripheral surface of the first metal tubular member and the second metal tubular member having an end portion disposed outside the joint structure, the outer peripheral surface of the first metal tubular member forming a joint surface in the joint structure; At least one of the inner peripheral surfaces of the member, and at least a part thereof, is formed with an uneven structure portion having a surface roughness larger than that of the surface of the metal tubular member as it is. .

With this configuration, the joint area between the two metal tubular members is increased, so that the joint strength between the two metal tubular members can be increased.
According to the metal tubular member joining structure according to the second aspect, the outer peripheral surface of the first metal tubular member and the inner peripheral surface of the second metal tubular member forming the joint surface in the joining structure Between them, a gap is formed into which a third substance as a bonding material for bonding the metal tubular members is poured.

According to this configuration, by forming an appropriate gap, it is possible to properly pour the third material such as metal as the joining member. In addition, since a portion with increased surface roughness is formed on the joint surface, it is possible to obtain an anchor effect of a third substance such as a metal as a joint material that is poured into the gap, thereby improving the joint strength. can be made

According to the metal tubular member joining structure according to the third aspect, the first metal tubular member and the second metal tubular member are joined by brazing, soldering, low temperature joining, or adhesive joining. is joined by any of

According to this configuration, not only can the copper tubular members be joined together, but also the aluminum tubular members can be joined together, and the aluminum tubular member and the copper tubular member can be easily joined.
According to the joining structure of metal tubular members according to the fourth aspect, as the concave-convex structure portion, the concave-convex portion having irregular concave-convex portions is formed.

According to this configuration, a portion having a large surface roughness can be formed by low-cost processing.
According to the joint structure for metal tubular members according to the fifth aspect, a groove-shaped portion constituted by grooves directed in a single direction is formed as the uneven structure portion, and the grooves constituting the groove-shaped portion are It is formed so as to communicate with the outside at the end of the joint surface.

According to this configuration, since a unidirectional groove-shaped portion communicating with the outside is formed at the end portion of the joint surface as the concave-convex structure portion, it is possible to suppress the occurrence of blowholes.
According to the joint structure for metal tubular members according to the sixth aspect, intersecting groove-shaped portions in which grooves intersect are formed as the uneven structure portion, and the grooves constituting the intersecting groove-shaped portions are It is formed so as to communicate with the outside at the end of the joint surface of the joint structure.

According to this configuration, the groove forming the groove-shaped portion communicates with the outside at the end of the tubular member on the joint surface, so that the occurrence of blowholes can be suppressed.
According to the joint structure for metal tubular members according to the seventh aspect, the outer peripheral surface of the first metal tubular member forming the joint surface is formed with a male thread as the concave-convex structure portion, and the joint surface is On the inner peripheral surface of the second metal tubular member forming the .

According to this configuration, the two metal tubular members are connected by screwing, so that the tubular members are less likely to be displaced. For this reason, a more stable connection can be achieved as compared with a non-screw connection.

According to the joint structure of metal tubular members according to the eighth aspect, the first metal tubular member and the second metal tubular member are copper, aluminum, iron, stainless steel, magnesium, and and the first metal tubular member and the second metal tubular member are made of the same or different metals.

This configuration allows the use of a wide variety of metals or combinations of metals.

Fig. 2 is a joint structure diagram of two metal tubular members according to Embodiment 1, in which (a) is a cross-sectional view when joined, (b) is a side view when not joined, and (c) a gap in the joint structure. Explanatory diagram. FIG. 10 is a structural diagram of joining two metal tubular members according to Embodiment 2, and is a side view when not joined. The side view of the 1st metal tubular member which concerns on Embodiment 3. FIG. The side view of the 1st metal tubular member which concerns on Embodiment 4. FIG. The side view of the 1st metal tubular member which concerns on Embodiment 5. FIG. FIG. 11 is a side view of a first metal tubular member according to Embodiment 6; Fig. 10 is a diagram showing the joint structure of two metal tubular members according to Embodiment 7, where (a) is a cross-sectional view when joined, (b) is a side view when not joined, and (c) is a male thread and a female thread. Partially enlarged view of the joint. Fig. 10 is a structure diagram of joining two metal tubular members according to Embodiment 8, where (a) is a cross-sectional view when joined, and (b) is a side view when not joined. Fig. 10 is a structure diagram of joining two metal tubular members according to Embodiment 9, where (a) is a cross-sectional view when joined, and (b) is a side view when not joined. FIG. 10A is a cross-sectional view of the joining structure of two metal tubular members according to Embodiment 10, and FIG. 11B is a side view of the first metal tubular member. 11A and 11B are diagrams of the joining structure of two metal tubular members according to Embodiment 11, where (a) is a cross-sectional view when joined, and (b) is a side view of the first metal tubular member.

(Embodiment 1)
A joining structure for metal tubular members according to the present disclosure will be described below.
The joining structure of two metal tubular members according to the present disclosure is one in which one end of two metal tubular members is inserted into the end of the other tubular member and joined. In addition, as shown in FIG. 1(a), in the present disclosure, a metal tubular member whose end portion is arranged inside in a joining structure of two metal tubular members is referred to as a first metal tubular member 1. In the joining structure of two metal tubular members, the metal tubular member whose end portion is arranged on the outside is referred to as a second metal tubular member 2 .

Embodiment 1 relates to a joining structure of copper pipes most commonly used in air conditioners as two metal tubular members. Brazing is used as the joining method. The first metal tubular member 1 and the second metal tubular member 2 are copper tubes having the same outer diameter. However, as shown in FIG. 1(a), the end portion of the copper pipe relating to the second metal tubular member 2 is expanded. This expanded tube portion forms a female side joint portion 21 for inserting and joining the end portion of the first metal tubular member 1 .

As shown in FIG. 1(b), the end of the copper tube that is the first metal tubular member 1 constitutes a male joint 11 that is inserted into the female joint 21 of the second metal tubular member 2. do. The outer peripheral surface of the male side joint portion 11 forms a joint surface 1 a with the second metal tubular member 2 . The joint surface 1a of the first metal tubular member 1 is formed with an uneven structure portion 3 having a larger surface roughness than the surface of the first metal tubular member 1 as it is. The outer peripheral surface 1b adjacent to the joint surface 1a (part other than the joint surface 1a) does not require any special processing, and the surface of the first metal tubular member 1 is left as it is.

On the other hand, the expanded end portion of the copper pipe, which is the second metal tubular member 2, constitutes the female joint portion 21 into which the male joint portion 11, which is the end portion of the first metal tubular member 1, is inserted, The inner peripheral surface of the female side joint portion 21 constitutes the joint surface 2 a with the first metal tubular member 1 . The joint surface 2a of the second metal tubular member 2 is formed with an uneven structure portion 3 having a larger surface roughness than the surface of the second metal tubular member 2 as it is. The inner peripheral surface 2b adjacent to the joint surface 2a (portion other than the joint surface 2a) does not require any special processing, and the surface of the second metal tubular member 2 is left as it is.

The concave-convex structure portion 3 formed on the joint surface 1a and the joint surface 2a is formed with fine concave-convex portions 31 having no regularity. As for the surface roughness of the concave-convex structure portion 3, it is preferable that the arithmetic mean roughness Ra specified in JIS B 0601 is 2 μm to 25 μm. The surface roughness of the other outer peripheral surface 1b adjacent to the joint surface 1a in the first metal tubular member 1 and the other inner peripheral surface 2b adjacent to the joint surface 2a in the second metal tubular member 2 is The surfaces of the tubular members 1 and 2 are left as they are, and the arithmetic mean roughness Ra is usually about 1 μm.

Next, various dimensions in the joining structure of the first metal tubular member 1 and the second metal tubular member 2 will be described with reference to FIG. 1(c). In this embodiment, the joint surface 1a, which is the outer peripheral surface of the male joint portion 11 of the first metal tubular member 1, and the joint surface, which is the inner peripheral surface of the female joint portion 21 of the second metal tubular member 2. Between the surfaces 2a, a gap S is formed into which a metal as a third substance other than the base material as a bonding material for bonding the metal tubular member is poured.

Also, the joint structure according to this embodiment is applied to brazing of copper pipes in air conditioners. For this reason, the provisions described in Table 23.8 of the Ministry of Economy, Trade and Industry Ordinance No. 12 "Ministerial Ordinance for Partial Revision of Refrigeration Safety Regulations" enforced on March 31, 2010 are applied to this brazing joint. . In this provision, the minimum fitting depth B shown in FIG. The dimension of the gap S (that is, CA) with a certain joint surface 2a is defined. Here, in relation to this embodiment, as shown in FIG. , C is the inner diameter of the female joint 21 . By the way, to show a part of it, when the outer diameter of the copper pipe is 12 mm or more and less than 16 mm, the minimum stuck depth B is 8 mm, and the dimension of the gap S (that is, CA) is 0.05 to 0.45. there is

(action)
Since Embodiment 1 is configured as described above, brazing is performed as follows. As an explanation of the operation of the first embodiment, the brazing joint in the first embodiment will be described below.

First, the concave-convex structure 3 is formed on the joint surface 1a, which is the outer peripheral surface of the male joint 11, at the end of the first metal tubular member 1 corresponding to the minimum insertion depth B. As shown in FIG. As the uneven structure portion 3, an uneven portion 31 composed of random unevenness 31a is formed on the entire joint surface 1a by shot blasting or the like. Next, flux is applied to the joint surface 1a of the first metal tubular member 1 and the joint surface 2a of the second metal tubular member to prevent the surface of the base material from being oxidized.

Next, the male joint portion 11 of the first metal tubular member 1 is inserted into the female joint portion 21 of the second metal tubular member 2 . Then, as shown in FIG. 1(c), the brazing filler metal 5 is placed at one end of the female joint 21, and the brazing filler metal 5 is heated at an appropriate heating temperature. It goes without saying that the brazing material may have a shape other than the ring shape shown in the drawing. For example, the shape may be rod-shaped, linear, foil-shaped, plate-shaped, paste-shaped, etc., depending on the conditions of use. When the brazing material is heated, the brazing material 5 melts, flows into the gap S, and spreads over the entire joining surfaces 1a and 2a. At this time, since the uneven structure portion 3 is formed on the joint surface 1a of the first metal tubular member 1, the joint area is increased. Further, as the uneven structure portion 3 of the joint surface 1a, an uneven portion 31 composed of fine unevenness 31a is formed. Therefore, the wetted length is increased, and the anchor effect of the melted brazing filler metal 5 can be obtained. The bonding strength between the first metal tubular member 1 and the second metal tubular member 2 can be improved by such an increase in the bonding area and the anchor effect. According to knowledge obtained from experiments, when the arithmetic mean roughness Ra is in the range of 25 μm or less, as the arithmetic mean roughness Ra increases, the wetting length, that is, the length over which the brazing material flows into the joint increases. has been confirmed.

(Effect of Embodiment 1)
Since the metal tubular member joining structure is configured as described above, the following effects can be obtained.

(1) In the joining structure of two metal tubular members, the outer peripheral surface of the male joint portion 11 of the first metal tubular member 1 and the inner peripheral surface of the female joint portion 21 of the second metal tubular member 2 Bonding surfaces 1a and 2a are formed. In this case, since the concave-convex portion 31 composed of fine concave-convex portions 31a is formed as the concave-convex structure portion 3 on one joint surface 1a, the joint area between the two metal tubular members is increased, and the two metal tubular members are joined together. The bonding strength of the members can be increased.

(2) Between the joint surface 1a that is the outer peripheral surface of the male joint portion 11 of the first metal tubular member 1 and the joint surface 2a that is the inner peripheral surface of the female joint portion 21 of the second metal tubular member 2 , there is formed a gap S into which a third substance other than the base material is poured as a bonding material for bonding the metal tubular members. As a result, the metal as the third substance (in this embodiment, the brazing filler metal 5) is poured, and the anchor effect of the metal as the third substance can be obtained.

(3) If the concave-convex structure portion 3 is precisely formed according to the insertion dimension of the joint surface 1a, the insertion dimension becomes clear, and excess or deficiency of insertion can be eliminated. As a result, it leads to reduction of defective products.

(Embodiment 2)
Next, a joint structure of two metal tubular members according to Embodiment 2 will be described with reference to FIG.

In Embodiment 1, only one of the joint surfaces 1a and 2a, specifically, the uneven structure portion 3 is formed only on the joint surface 1a. A similar uneven structure 3 is formed. Embodiment 1 and Embodiment 2 differ only in this point, and all other points are the same.

The second embodiment configured as described above can achieve the same effect as the first embodiment. Moreover, when compared with the first embodiment, the joint area between the two metal tubular members is further increased. In addition, since the irregularities 31 composed of fine irregularities 31 are formed on both joint surfaces 1a and 2a, the anchor effect can be further enhanced. Therefore, the bonding strength of the second embodiment is improved over that of the first embodiment.

(Embodiment 3)
Next, a joint structure of two metal tubular members according to Embodiment 3 will be described with reference to FIG.

Embodiment 3 is obtained by changing the unevenness specifications of the uneven structure portion 3 in Embodiment 1. FIG. That is, the concave-convex specification of the concave-convex structure portion 3 in Embodiment 3 is a groove-shaped portion 32 in which grooves 32a extending in the pipe axis direction are arranged at a constant pitch. The groove 32a of the groove-shaped portion 32 may be formed by marking or the like. One end of the groove 32a of the groove-shaped portion 32 is formed so as to communicate with the outside at the end of the joint surface 1a. The groove depth, width, pitch, etc. of the groove-shaped portion 32 are not particularly limited.

Since the third embodiment is configured as described above, it is possible to obtain the same effects as those of the first embodiment. Further, in Embodiment 3, a groove-shaped portion 32 composed of fine grooves 32a oriented in a single direction is formed in the concave-convex structure portion 3, and the grooves 32a are formed so as to communicate with the outside at the end portion of the joint surface 1a. Therefore, the wettability is improved and the occurrence of blowholes can be suppressed.

(Embodiment 4)
Next, a joint structure of two metal tubular members according to Embodiment 4 will be described with reference to FIG.

The fourth embodiment is obtained by changing the direction of the grooves 32a in the third embodiment. That is, in the third embodiment, the grooves 32a of the groove-shaped portion 32 are oriented in the pipe axis direction, but in the fourth embodiment, the grooves 33a forming the groove-shaped portion 33 are slanted so as to intersect the pipe axis. It is aimed at Since the fourth embodiment is the same as the third embodiment except for this point, the same effects as the third embodiment can be obtained.

(Embodiment 5)
Next, a joint structure of two metal tubular members according to Embodiment 5 will be described with reference to FIG.

The fifth embodiment is obtained by changing the configuration of the groove-shaped portion 32 in the third embodiment. That is, in the fifth embodiment, the uneven structure portion 3 is formed with intersecting groove portions 34 in which the grooves 34a intersect in the pipe axial direction and in the direction perpendicular to the pipe axial direction in a grid pattern. A groove 34a extending in the pipe axis direction of the intersecting groove-shaped portion 34 is formed so as to communicate with the outside at the end portion of the joint surface 1a.

Since the fifth embodiment is configured as described above, all the grooves 34a are communicated with the outside through the end portions of the joint surfaces 1a. can be suppressed.

(Embodiment 6)
Next, a joint structure of two metal tubular members according to Embodiment 6 will be described with reference to FIG.

In the sixth embodiment, the orientation of the grooves 34a forming the groove-shaped portion 34 in the fifth embodiment is changed. That is, the groove-like portion 35 of Embodiment 6 is formed in a cross shape by slanting all the grooves 35a constituting the groove-like portion 35 with respect to the tube axis direction.

Since the sixth embodiment is configured as described above, it is possible to obtain the same effects as those of the fifth embodiment.
(Embodiment 7)
Next, a joint structure of two metal tubular members according to Embodiment 7 will be described with reference to FIG. Differences from the first embodiment will be mainly described below.

As shown in FIG. 7(a), the two metal tubular members in Embodiment 7 have different external dimensions. A first metal tubular member 1 is a metal tubular member having a small outer dimension. The end portion of the first metal tubular member 1 constitutes a male joint portion 11, the outer peripheral surface of which constitutes the joint surface 1a. Further, as shown in FIG. 7(b), a male thread 36 is formed as the concave-convex structure portion 3 on the joint surface 1a, which is the outer peripheral surface of the male side joint portion 11. As shown in FIG.

On the other hand, the second metal tubular member 2 is a metal tubular member having a large outer dimension. The end of the second metal tubular member 2 forms a female joint 21, the inner peripheral surface of which constitutes the joint surface 2a. In addition, a female thread 37 to be screwed with the male thread 36 is formed as the concave-convex structure portion 3 on the joint surface 2 a that is the inner peripheral surface of the female side joint portion 21 .

As shown in FIG. 7(c), a gap S exists between the screwing surfaces of the male thread 36 and the female thread 37, as seen in general screw structures. This gap S constitutes the gap S into which the metal as the third substance other than the base material as the bonding material for joining the metal tubular members is poured in in the present disclosure.

Since the seventh embodiment is configured as described above, the effects (1) and (3) of the first embodiment are obtained. Moreover, in Embodiment 7, welding is performed using a metal as the third substance as a bonding material after the screws are screwed together, so there is no misalignment and the bonding strength is increased.

(Embodiment 8)
Next, a joint structure of two metal tubular members according to Embodiment 8 will be described with reference to FIG. Differences from the seventh embodiment will be mainly described below.

The two metal tubular members in the eighth embodiment have the same external dimensions as shown in FIG. 8(a). The end of one metal tubular member is expanded. The unexpanded metal tubular member is the first metal tubular member 1 , and the expanded metal tubular member is the second metal tubular member 2 .

As shown in FIG. 8(b), the end portion of the first metal tubular member 1 constitutes the male side joint portion 11, and the outer peripheral surface thereof constitutes the joint surface 1a, as in the seventh embodiment. there is A male thread 36 is formed as the concave-convex structure portion 3 on the joint surface 1 a that is the outer peripheral surface of the male joint portion 11 . The expanded end portion of the second metal tubular member 2 forms a female joint portion 21, the inner peripheral surface of which constitutes the joint surface 2a. In addition, on the joint surface 2a, which is the inner peripheral surface of the female side joint portion 21, a female thread 37 is formed as the concave-convex structure portion 3 in the same manner as in the seventh embodiment so as to be screwed into the male thread 36 of the first metal tubular member 1. It is

Since the eighth embodiment is configured as described above, the same effects as those of the seventh embodiment can be obtained.
(Embodiment 9)
Next, a joint structure of two metal tubular members according to Embodiment 9 will be described with reference to FIG. Differences from the seventh embodiment will be mainly described below.

The two metal tubular members in the ninth embodiment have the same external dimensions as shown in FIG. 9(a). The end of one metal tubular member is crimped. The compressed metal tubular member is the first metal tubular member 1 , and the unconstricted metal tubular member is the second metal tubular member 2 .

As shown in FIG. 9(b), the compressed end of the first metal tubular member 1 constitutes a male joint 11, the outer peripheral surface of which constitutes the joint surface 1a. A male thread 36 is formed as the concave-convex structure portion 3 on the joint surface 1 a that is the outer peripheral surface of the male joint portion 11 . The end portion of the second metal tubular member 2 that is not compressed constitutes a female side joint portion 21, the inner peripheral surface of which constitutes the joint surface 2a. In addition, on the joint surface 2a, which is the inner peripheral surface of the female side joint portion 21, a female thread 37 is formed as the concave-convex structure portion 3 in the same manner as in the seventh embodiment so as to be screwed into the male thread 36 of the first metal tubular member 1. It is

Since the ninth embodiment is configured as described above, the same effects as those of the seventh and eighth embodiments can be obtained.
(Embodiment 10)
Next, a joint structure of two metal tubular members according to Embodiment 10 will be described with reference to FIG. 10 .

As can be seen from FIGS. 10(a) and 10(b), in the tenth embodiment, the second metal tubular member 2 is a copper alloy socket in the first embodiment. The first metal tubular member 1 in this embodiment is a copper tube having the same structure as in the first embodiment. Further, the socket as the second metal tubular member 2 has substantially the same pipe insertion portion as the female side joint portion 21 in the first embodiment.

Therefore, the joining structure between the first metal tubular member 1 and the second metal tubular member 2 in the tenth embodiment is the same as in the first embodiment even if the second metal tubular member 2 is different. , and the same effect as in the first embodiment can be obtained.

(Embodiment 11)
Next, a joint structure of two metal tubular members according to Embodiment 11 will be described with reference to FIG. 11 .

As can be seen from FIGS. 11(a) and 11(b), in the eleventh embodiment, the second metal tubular member 2 in the first embodiment is a copper alloy stop valve. The first metal tubular member 1 in this embodiment is a copper tube having the same structure as in the first embodiment. The closing valve as the second metal tubular member 2 includes a housing 60, a valve body 62 that is operated to move in the Y direction with respect to the valve seat 61, a cap member 63, and the like. The insertion part is substantially the same as the female side joint part 21 in the first embodiment.

Therefore, the joint structure between the first metal tubular member 1 and the second metal tubular member 2 in the eleventh embodiment is the same as that in the first embodiment even if the second metal tubular member 2 is different. , and the same effect as in the first embodiment can be obtained.

(Modification)
The joining structure of metal tubular members of the present disclosure may be, in addition to the above-described embodiments, modified examples shown below, or a combination of at least two mutually consistent modified examples.

- In each of the above-described embodiments, the first metal tubular member 1 and the second metal tubular member 2 are joined by brazing. may be joined by any of In this specification, low-temperature bonding refers to bonding at a temperature of less than 450° C., but the melting temperature of the bonding material after bonding is 450° C. or higher. Examples of such a bonding material include silver nanoparticles.

- The material of the first metal tubular member 1 and the second metal tubular member 2 may be copper or a copper alloy used in the above embodiments, but is not limited to this. That is, the materials of the first metal tubular member 1 and the second metal tubular member 2 are made of a metal selected from copper, aluminum, iron, stainless steel, magnesium, and alloys containing these, and may be made of the same or different metals.

・In the above-described Embodiments 3 to 6, the concave-convex structure portion 3 is formed only on the outer peripheral surface of the male side joint portion 11 forming the joint surface 1a of the first metal tubular member 1. Similarly to the case, the concave-convex structure portion 3 may also be formed on the inner peripheral surface of the female side joint portion 21 forming the joint surface 2 a of the second metal tubular member 2 .

・In addition, the concave-convex structure portion 3 is not formed on the outer peripheral surface of the male side joint portion 11 forming the joint surface 1a of the first metal tubular member 1, but is formed on the female side forming the joint surface 2a of the second metal tubular member 2. It may be formed only on the inner peripheral surface of the side joint portion 21 .
,
・The concave-convex structure part 3 is formed on the outer peripheral surface of the male side joint part 11 forming the joint surface 1a of the first metal tubular member 1, and the female side joint forming the joint surface 2a of the second metal tubular member 2. The inner peripheral surface of the portion 21 need not have the same specifications. For example, in Embodiment 2, as the uneven structure 3 on the inner peripheral surface of the female joint 21, the groove-shaped portion 32 configured by the grooves 34a directed in a single direction, which is applied in Embodiment 3, is applied. You may

- In each of the above-described embodiments, the concave-convex structure portion 3 was formed over the entire joint surface 1a of the first metal tubular member 1 or the joint surface 2a of the second metal tubular member 2. It may be formed on a part of the joint surface 2a.

In addition, in each of the above-described embodiments, the concave-convex structure portion 3 is formed on the entire surface of the joint surface 1a of the first metal tubular member 1 or the joint surface 2a of the second metal tubular member 2. , the outer peripheral surface 1b of the first metal tubular member 1 adjacent to the joint surface 1a or the inner peripheral surface 2b of the second metal tubular member 2 adjacent to the joint surface 2a.

Although embodiments of the present disclosure have been described above, it will be appreciated that various changes in form and detail may be made without departing from the spirit and scope of the present disclosure as set forth in the appended claims. .

A Outside diameter of joining surface (of first metal tubular member) B Minimum depth of engagement C Inside diameter of joining surface (of second metal tubular member) S Gap Y (Valve element movement) direction 1 First metal Tubular member 1a Joint surface 1b Outer peripheral surface 2 (adjacent to the joint surface of the first metal tubular member) Second metal tubular member 2a Joint surface 2b Inner peripheral surface (adjacent to the joint surface of the second metal tubular member) 3 Concavo-convex structure 5 Brazing filler metal 11 Male joint 21 Female joint 31 Concave-convex portion 31a (Unregular fine) concavo-convex 32 Groove-shaped portion 32a (Micro unidirectional) groove 33 Groove-shaped portion 33a (Minor unidirectional) grooves 34 (intersecting) groove-like portions 34a (intersecting lattice-like) grooves 35 (intersecting) groove-like portions 35a (diagonally crossing the pipe axis) grooves 36 male screw 37 female screw 60 housing 61 valve seat 62 valve element 63 cap member

Claims (3)

A joint structure of two metal tubular members,
a first metal tubular member (1), the end of which is located inside the joint structure;
a second metallic tubular member (2), the end of which is located outside the joining structure;
At least one of the outer peripheral surface of the first metal tubular member (1) and the inner peripheral surface of the second metal tubular member (2), which form the joint surfaces (1a, 2a) in the joint structure and at least a part thereof is formed with an uneven structure portion (3) having a larger surface roughness than the surfaces of the metal tubular members (1, 2) as they are,
A male thread (36) is formed as the uneven structure (3) on the outer peripheral surface of the first metal tubular member (1) forming the joint surface (1a). Consists of a spiral convex portion having one surface and a second surface,
On the inner peripheral surface of the second metal tubular member (2) forming the joint surface (2a), there is a female thread (37) that is screwed into the male thread (36) as the uneven structure (3). formed, said internal thread (37) being constituted by a helical recess having a third side and a fourth side,
In a state where the female screw (37) is screwed into the male screw (36), the first surface of the spiral convex portion faces the third surface of the spiral concave portion, and the second surface of the spiral convex portion faces the third surface of the spiral concave portion. is opposed to the fourth surface of the spiral recess, and a gap (S) is formed between the first surface and the third surface or between the second surface and the fourth surface.be,
The gap (S) is configured so that a third substance as a bonding material for bonding the metal tubular members (1, 2) can be poured.
Joint structure of metal tubular members. The first metal tubular member (1) and the second metal tubular member (2) are joined by one of brazing, soldering, low temperature joining, and adhesive joining.
Claim 1 A joint structure for metal tubular members as described above. The first metal tubular member (1) and the second metal tubular member (2) are each made of a metal selected from copper, aluminum, iron, stainless steel, magnesium, and alloys containing these. and the first metal tubular member (1) and the second metal tubular member (2) are made of the same or different metals
Claim 1 or 2 2. The joining structure of metal tubular members according to 1.

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