JP2022148042A - Clad pipe for joint, manufacturing method therefor, and clad pipe joint - Google Patents

Abstract

To provide a high-airtightness clad pipe for a joint in which there is no gas failure in a case of connecting pipes of different metals, a manufacturing method therefor, and clad pipe joint.SOLUTION: One end part comprises a multi-layer structure made of different metals, and the other end part comprises a single-layer structure.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a clad pipe for a joint used for connecting pipes made of dissimilar metals, a method for manufacturing the clad pipe, and a clad pipe joint connecting the clad pipes.

Traditionally, copper fittings have been mainly used for equipment such as refrigerant pipes and valve devices in air conditioning and refrigeration systems. demand is increasing.

However, at present, copper piping is still the mainstream, so copper piping must be assumed as the counterpart of the joint connection. In this regard, when connecting a copper pipe to a stainless joint, dissimilar metals are joined together. Brazing is often used to join dissimilar metals together, but flux is required for brazing, and this flux must be completely removed while the product is connected to an air conditioning/refrigeration system. is difficult.

As a countermeasure, for example, as shown in FIG. Here, the joint clad pipe 104 is connected to the stainless steel pipe 106 to form a clad pipe joint 108 .

As a result, it is possible to join copper layers of the same kind of metal without flux. 106a is required to be airtight.

JP-A-63-194824

By the way, as a method of manufacturing the joint clad tube 104 as described above, a manufacturing method is known in which a material obtained by stacking a plurality of metal plates is formed into a joint shape by deep drawing (for example, see Patent Document 1). When the joint clad tube 104 is manufactured by this method, the material is thinly drawn, so there is a concern that wrinkles and cracks may occur in the molded product.

Further, even when the clad pipe joint 108 prepared by welding the joint clad pipe 104 to the stainless steel pipe 106 is joined to the copper pipe 102 (see FIG. 10), the joint portion 109 between the joint clad pipe 104 and the stainless steel pipe 106 becomes welding between the copper layer 104a and the stainless steel layer 106a, and there is a concern that the welding becomes unstable.

Both of these concerns cause poor airtightness between the copper layer 104a and the stainless steel layers 104b and 106a, so there is a problem in manufacturing the joint clad tube 104 with stable airtight quality.
SUMMARY OF THE INVENTION An object of the present invention is to provide a highly airtight clad pipe for a joint, a method for manufacturing the clad pipe, and a clad pipe joint that does not cause poor airtightness when pipes made of dissimilar metals are joined.

The clad pipe for a joint of the present invention is
One end is provided with a multi-layer structure made of dissimilar metals, and the other end is provided with a single-layer structure.

As a result, it is possible to provide a highly airtight clad pipe for a joint that does not cause poor airtightness even when one end and the other end are joined to pipes made of different metals.

Further, the clad pipe for a joint of the present invention is
Formed with stainless steel as the main material,
The one end has a copper layer inside or outside the stainless steel layer,
The other end is characterized by having a stainless steel single layer structure.

As a result, it is possible to realize a structure in which one end is provided with a multilayer structure of different metals of a stainless steel layer and a copper layer, and the other end is provided with a single layer structure consisting only of a stainless steel layer. It is possible to provide a clad pipe for a joint with high airtightness that does not cause poor airtightness when a stainless steel pipe is joined to a pipe.

Further, the clad pipe for a joint of the present invention is
The axial length of the copper layer with respect to the outer diameter of the stainless steel layer is 0.1 or more and 1.2 or less,
The axial length of the stainless steel layer with respect to the axial length of the copper layer is 1.25 or more and 5.0 or less.
That is, it is preferable to produce the joint clad pipe with such dimensions.

The method for manufacturing a clad pipe for a joint of the present invention comprises:
A bonding step of bonding a copper plate having a smaller area than the stainless steel plate to one side of the stainless steel plate to create a clad material;
and a drawing step of forming the original clad pipe by drawing the clad material.

In this way, by minimizing the area of the copper plate used as the clad material, the copper plate is not deep-drawn even when the clad material is deep-drawn, and wrinkles can be suppressed in the original clad pipe. Airtightness failure is prevented also from this point.

Further, the method for manufacturing a clad pipe for a joint according to the present invention includes:
An opening hole is formed in the center of the copper plate that constitutes the clad material, or a through hole that penetrates the clad material is formed in the center of the clad material.

In this way, by forming an opening hole in the copper plate, it is possible to reduce the burden of cutting the bottom of the original clad pipe, and by forming a through hole in the clad material, it is possible to directly connect the pipe without cutting the bottom. A clad tube can be created.

The clad pipe joint of the present invention is
formed by welding the other end of the joint clad tube, which has a stainless steel single-layer structure, to a stainless steel pipe,
The one end of the clad tube for joint is connected to the copper pipe by inserting the copper layer formed inside or outside the stainless steel layer into the outer peripheral surface or the inner peripheral surface of the copper pipe and joining them airtightly. characterized by

According to this, most of the clad pipe joint is made of stainless steel, so that the cost of the product can be reduced. In addition, since one end is connected to the copper pipe with the same kind of metal of copper, while it is possible to use brazing, flux is not required, which simplifies the process of connecting the clad pipe joint. can.

Advantageous Effects of Invention According to the present invention, it is possible to provide a highly airtight clad pipe for a joint, a method for manufacturing the same, and a clad pipe joint, which do not cause poor airtightness when pipes made of dissimilar metals are joined.

It is a figure which shows the clad pipe joint which concerns on embodiment. FIG. 2 is a diagram showing a joint clad tube according to an embodiment; It is a figure which shows the clad material for manufacturing the clad pipe for joints which concerns on embodiment, and an original clad pipe. It is a figure which shows the processing apparatus for producing the clad pipe which concerns on embodiment. It is a figure which shows the specific example of a dimension of the clad pipe joint which concerns on embodiment. FIG. 10 is a diagram showing a clad material for manufacturing a joint clad pipe according to another embodiment, and an original clad pipe; FIG. 10 is a diagram showing a clad material for manufacturing a joint clad pipe according to another embodiment, and an original clad pipe; FIG. 10 is a diagram showing a joint clad tube according to another embodiment; It is a figure which shows the clad pipe joint which concerns on other embodiment. FIG. 10 is a diagram showing a conventional clad pipe joint;

Next, the invention according to the embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a clad pipe joint 2 according to an embodiment. The clad pipe joint 2 is used as a joint for equipment such as refrigerant pipes and valve devices in an air conditioning/refrigeration system (hereinafter abbreviated as equipment). Moreover, FIG. 2 is a figure which shows the clad pipe 4 for joints which concerns on embodiment.

As shown in FIG. 1, the clad pipe joint 2 is formed by welding a joint clad pipe 4 to a stainless steel pipe 6, and is connected to a mating copper pipe 8. As shown in FIG. As shown in FIG. 2, the joint clad tube 4 is mainly made of stainless steel, and is formed by laminating a copper layer 4d on the inner diameter side of a stainless steel layer 4c from one end 4a to an intermediate portion in the axial direction. . For this reason, one end portion 4a has a multi-layer structure composed of a stainless steel layer 4c and a copper layer 4d made of dissimilar metals, and the other end portion 4b has a single-layer structure composed only of the stainless steel layer 4c.

Here, the outer diameter (Ds) of the stainless steel layer 4c of the joint clad tube 4 is 6 mm or more and 35 mm or less, and the layer thickness (Ts) of the stainless steel layer 4c is 0.3 mm or more and 2.5 mm or less. Further, the axial length (Lc) of the copper layer 4d with respect to the outer diameter (Ds) of the stainless steel layer 4c, that is, Lc/Ds, is 0.1 or more and 1.2 or less. Further, the axial length (Ls) of the stainless steel layer 4c with respect to the axial length (Lc) of the copper layer 4d, that is, Ls/Lc, is 1.25 or more and 5.0 or less. Also, the layer thickness (Tc) of the copper layer 4d with respect to the layer thickness (Ts) of the stainless steel layer 4c, that is, Tc/Ts, is 0.1 or more and 1.0 or less.

Next, a method for manufacturing the joint clad tube 4 will be described. FIG. 3(a) is a top view of a clad material 10, which will be described later, and FIG. 3(b) is a side view thereof. First, a stainless steel plate 10a, which is a disc made of stainless steel, and a copper plate 10b, which is a disc made of copper and whose area (diameter) is smaller than that of the stainless steel plate 10a, are prepared. After aligning the centers of both, the copper plate 10b is joined to one side of the stainless steel plate 10a to form the clad material 10. As shown in FIG. Here, the stainless steel plate 10a and the copper plate 10b are joined by, for example, diffusion bonding or pressure welding.

Next, using a processing apparatus 12 as shown in FIG. 4, the clad material 10 is subjected to drawing, and a copper layer 4d is formed only on the bottom side of the inner diameter side as shown in FIG. 3(c). A test-tube-shaped original clad tube 14 is produced (drawing process). Next, the bottom side of the original clad tube 14 is cut to form the joint clad tube 4 shown in FIG. 2 (cutting step).

Next, as shown in FIG. 1, the clad pipe joint 2 is completed by connecting the stainless steel pipe 6 of the equipment to the other end portion 4b of the joint clad pipe 4 and welding. Here, the copper layer 4d is not laminated on the other end portion 4b, and the same kind of metals are welded together when joining to the stainless steel pipe 6. Therefore, welding by welding dissimilar metals such as copper and stainless steel Instability can be avoided, and airtightness failure at the joint portion of the other end portion 4b can be prevented.

After the device is shipped with the clad pipe joint 2 formed at the tip of the stainless steel pipe 6, it is connected to the copper pipe 8 at the delivery destination. At the delivery destination, one end 4a of the clad pipe for joint 4 is inserted so that the outer peripheral surface of the copper pipe 8 overlaps the inner peripheral surface of the copper layer 4d, as shown in FIG. It is airtightly joined to the copper pipe 8 by brazing all around. Therefore, at the joint portion of the one end portion 4a, it is possible to prevent airtightness defects that are likely to occur when dissimilar metals are connected.

Note that FIG. 5 shows an example of specific dimensions of the clad pipe joint 2 produced as described above, for a typical refrigerant 3 with a layer thickness (Tcu) of 0.8 mm and an outer diameter (Dcu) of 9.52 mm. A case where a /8 inch copper pipe 8 is connected to the inner peripheral surface of the clad pipe 4 for joint according to the embodiment to create the clad pipe joint 2 is illustrated as an example.

Here, the joint clad pipe 4 connected to the copper pipe 8 has an outer diameter (Ds) of 12.02 mm, an inner diameter (Dsi) of 10.42 mm, an axial length (Ls) of 14 mm, and a layer thickness (Ts) of 0.4 mm. It has an 8 mm stainless steel layer 4c and a copper layer 4d with an outer diameter (Dc) of 9.62 mm, an axial length (Lc) of 7 mm, and a layer thickness (Tc) of 0.4 mm. Here, the axial length (Lc) of the copper layer 4d with respect to the outer diameter (Ds) of the stainless steel layer 4c, ie, Lc/Ds, is 0.582. Also, the axial length (Ls) of the stainless steel layer 4c with respect to the axial length (Lc) of the copper layer 4d, ie, Ls/Lc, is 2.0. Also, the layer thickness (Tc) of the copper layer 4d with respect to the layer thickness (Ts) of the stainless steel layer 4c, that is, Tc/Ts, is 0.5. When connecting the copper pipe 8 and the joint clad pipe 4 by brazing, the general gap is about 0.1 mm.

According to the invention according to this embodiment, one end portion 4a has a multi-layer structure made of different metals including a stainless steel layer 4c and a copper layer 4d, and the other end portion 4b has a single layer structure consisting only of the stainless steel layer 4c. Therefore, it is possible to provide a highly airtight joint clad pipe that does not cause airtightness failure when a copper pipe 8 is joined to one end 4a and a stainless steel pipe 6 is joined to the other end 4b.

Further, by making the copper plate 10b used for the clad material 10 have the minimum area, even when the clad material 10 is deep drawn, the copper plate 10b is not deep drawn, and the original clad pipe 14 (see FIG. 3) is wrinkled. Since it is possible to suppress the occurrence of airtightness failure, airtightness failure is prevented from this point as well.

Moreover, since most of the clad pipe joint 2 is made of stainless steel, the cost of the product can be reduced.
Further, conventionally, when a joint made of dissimilar metals such as stainless steel is joined to a copper pipe 8 by brazing, flux is required, which complicates the process, and the flux and brazing material cause a problem of increased cost. rice field. On the other hand, in the invention according to the embodiment, since the clad pipe joint 2 is airtightly joined to the copper pipe 8 by the same kind of metal of copper, no flux is required for brazing, and the clad pipe joint 2 can be simplified.

In the above embodiment, as shown in FIGS. 6(a) and 6(b), the clad material 10' in which a copper plate 10b' having an opening hole 10b1 formed in the center is superimposed on the stainless plate 10a is used as the original clad material 10'. A cladding tube 14' may be fabricated. In this case, since the opening hole 10b1 is formed in the copper plate 10b', the bottom is not formed in the copper layer 4d after drawing the clad material 10' as shown in FIG. 6(c). , the burden in the cutting process can be reduced.

In addition, as shown in FIGS. 7(a) and 7(b), a stainless steel plate 10a' having an opening hole 10a1 formed in the center is superimposed on the copper plate 10b', and a clad having a through hole 10e formed in the center. Material 10'' can also be made. The joint clad pipe 4 may be produced using this clad material 10 ″. In this case, since both the copper plate 10b' and the stainless steel plate 10a' are open, as shown in FIG. , the cutting process itself can be omitted, and the clad pipe 4 for direct connection can be produced.

In the above-described embodiment, as shown in FIG. 8, the joint clad tube 4' may be formed by laminating the copper layer 4d on the outer diameter side of the stainless steel layer 4c. In this case also, the one end portion 4a has a multi-layer structure made of different metals of the stainless steel layer 4c and the copper layer 4d, and the other end portion 4b has a single layer structure consisting only of the stainless steel layer 4c.

Here, the joint clad tube 4' also has an outer diameter (Ds) of 6 mm or more and 35 mm or less, similar to the joint clad tube 4 in which the copper layer 4d is laminated on the inner diameter side of the stainless steel layer 4c. The layer thickness (Ts) of the stainless steel layer 4c is 0.3 mm or more and 2.5 mm or less. Further, the axial length (Lc) of the copper layer 4d with respect to the outer diameter (Ds) of the stainless steel layer 4c, that is, Lc/Ds, is 0.1 or more and 1.2 or less. Further, the axial length (Ls) of the stainless steel layer 4c with respect to the axial length (Lc) of the copper layer 4d, that is, Ls/Lc, is 1.25 or more and 5.0 or less. Also, the layer thickness (Tc) of the copper layer 4d with respect to the layer thickness (Ts) of the stainless steel layer 4c, that is, Tc/Ts, is 0.1 or more and 1.0 or less.

Here, as shown in FIG. 9, the clad pipe joint 2' is completed by connecting the stainless steel pipe 6 of the equipment to the other end portion 4b of the joint clad pipe 4' and welding. Even in this case, since the metals of the same kind are welded together when joining with the stainless steel pipe 6, it is possible to prevent airtightness failure at the joining portion of the other end portion 4b.

One end 4a of the joint clad tube 4' is inserted so that the inner peripheral surface of the copper pipe 8 overlaps the outer peripheral surface of the copper layer 4d, and the copper pipe is formed by brazing the same kind of copper to each other. 8, and airtight failure that tends to occur when dissimilar metals are connected is prevented.

Further, the one end portion 4a of the joint clad pipes 4, 4' may not necessarily have the stainless steel layer 4c and the copper layer 4d as long as it has a multi-layered structure made of dissimilar metals. An aluminum layer may be provided instead of the copper layer 4d. In this case, airtightness failure can be prevented when one end portion 4a is joined to an aluminum pipe (not shown).

2, 2' clad pipe joint 4, 4' clad pipe for joint 4a one end 4b other end 4c stainless layer 4d copper layer 6 stainless steel pipe 8 copper pipe 10, 10', 10'' clad material 10a, 10a' stainless steel plate 10a1 opening holes 10b, 10b' copper plate 10b1 opening hole 10e through-hole 12 processing device 14, 14' original clad pipe 102 copper pipe 104 joint clad pipe 104a copper layer 104b stainless steel layer 106 stainless steel pipe 106a stainless steel layer 107 connecting portion 108 clad pipe joint 109 joint

Claims (6)

A clad tube for a joint, characterized in that one end has a multi-layer structure made of dissimilar metals and the other end has a single-layer structure. Formed with stainless steel as the main material,
The one end has a copper layer inside or outside the stainless steel layer,
2. The joint clad tube according to claim 1, wherein the other end has a stainless steel single layer structure. The axial length of the copper layer with respect to the outer diameter of the stainless steel layer is 0.1 or more and 1.2 or less,
3. The clad tube for a joint according to claim 2, wherein the axial length of said stainless steel layer with respect to the axial length of said copper layer is 1.25 or more and 5.0 or less. 4. The method for manufacturing the joint clad pipe according to claim 2 or 3,
A bonding step of bonding a copper plate having a smaller area than the stainless steel plate to one side of the stainless steel plate to create a clad material;
A method of manufacturing a clad pipe for a joint, comprising: a drawing step of drawing the clad material to prepare an original clad pipe. 5. The joint according to claim 4, wherein an opening hole is formed in the center of said copper plate constituting said clad material, or a through hole is formed in the center of said clad material to pass through said clad material. A method of manufacturing a clad tube for A clad pipe joint using the clad pipe for joint according to claim 2 or 3,
formed by welding the other end of the joint clad tube, which has a stainless steel single-layer structure, to a stainless steel pipe,
The one end of the clad tube for joint is connected to the copper pipe by inserting the copper layer formed inside or outside the stainless steel layer into the outer peripheral surface or the inner peripheral surface of the copper pipe and joining them airtightly. A clad pipe joint characterized by:

Images