WO2018036366A1

WO2018036366A1 - Connection structure of composite pipe and pipe assembly

Info

Publication number: WO2018036366A1
Application number: PCT/CN2017/095917
Authority: WO
Inventors: 王一奇; 庄新宇; 潘勇; 张志军
Original assignee: 浙江三花智能控制股份有限公司
Priority date: 2016-08-24
Filing date: 2017-08-04
Publication date: 2018-03-01
Also published as: CN107781541A; CN107781541B

Abstract

A connection structure of a composite pipe and a pipe assembly are provided. The composite pipe (1) comprises a steel pipe body (14). A copper layer (13) is disposed at least on an inner surface of the steel pipe body (14). An end portion of the connection structure comprises sequentially from the outside to the inside a bending section (11) and a matching section (12). An inner diameter of the bending portion (11) is greater than an inner diameter of the matching section (12). When the composite pipe (1) is welded and assembled with a pipe member (2) to be welded, the matching section (12) of the connection structure is sleeved over a matching end portion of the pipe member (2) to be welded, and weld metal can be filled between an inner surface of the bending section (11) and an outer surface of the pipe member (2) to be welded, thereby effectively preventing the weld metal from contacting an end surface of the composite pipe, preventing phosphorus in the weld metal from contacting the steel pipe body (14). Thus, a lattice distortion phenomenon caused by the fusing of phosphorus with the steel material in the prior art is eliminated, such that the toughness and the plasticity of the composite pipe (1) after the welding is enhanced, thereby enhancing the performance of the product. In addition, because a weld seam is formed between the copper layer (13) and the pipe member (2) to be welded, the fluidity of the weld metal is not affected by the steel material when the weld metal melts, obtaining better fluidity and weld quality.

Description

Interface structure and tube assembly of composite pipe

The present application claims priority to Chinese Patent Application No. 201610727277.3, entitled "Interface Structure and Tube Assembly of a Composite Pipe", filed on August 24, 2016, the entire contents of which are incorporated herein by reference. In this application.

Technical field

The invention relates to the technical field of welding, in particular to an interface structure and a pipe assembly of a composite pipe.

Background technique

In the prior art, the pipeline components used in the refrigeration system are generally copper, because the copper material has good corrosion resistance and workability, but the price of the copper pipe is relatively high, and the more copper pipes are used, the product processing The higher the cost. Therefore, the interface pipe between the copper pipe and the copper pipe is usually a copper-steel composite pipe.

Please refer to FIG. 1. FIG. 1 is a schematic view showing the assembly of a prior art copper tube and a copper-steel composite tube.

The prior art copper-steel composite pipe 1' mainly comprises a steel main pipe and a copper layer provided on the outer or inner surface of the steel main pipe. The inner and outer peripheral faces of the steel main pipe of the copper-steel composite pipe 1' in Fig. 1 are each provided with a copper layer, and the welded pipe section of the copper pipe 2' is inserted into the inside of the copper-steel composite pipe 1'. Usually, the copper-steel composite pipe 1' is usually fixed to the copper pipe 2' by welding. When welding, the copper pipe 2' is sleeved inside the copper-steel composite pipe 1' or the copper-steel composite pipe 1' is sleeved on the copper pipe 2. 'Internal, using either silver or phosphor bronze for welding. To save welding costs, it is preferred to use phosphor bronze.

Please refer to FIG. 2, which is a partial enlarged view of FIG.

A part of the solder is spread on the end face 11' of the copper-steel composite pipe 1', and the other portion is filled between the copper pipe and the copper-steel composite pipe 1' socket portion. After the copper-steel composite pipe 1' and the copper pipe are welded with phosphor bronze, the strength and hardness of the welded section of the copper-steel composite pipe 1' are obviously increased, resulting in a significant decrease in toughness and plasticity, which seriously affects the performance of the product. Especially in the low temperature working area of the refrigeration system, this phenomenon is more serious and even appears cold and brittle.

Therefore, how to avoid the use of the copper-steel composite pipe welded section after the phosphor bronze welding performance deterioration, eliminate the cold and brittle phenomenon, and thereby improve the use performance of the refrigeration system, is a technical problem to be solved by those skilled in the art.

Summary of the invention

In order to solve the above technical problem, the present invention provides an interface structure of a composite pipe, the composite pipe includes a steel pipe body, and at least an inner surface of the steel pipe body is provided with a copper layer, and an end portion of the interface structure is The outwardly inward direction includes a bending section and a fitting section, the inner diameter of the bending section being larger than the inner diameter of the fitting section.

When the composite pipe in this paper is welded and assembled with the copper pipe (or other material to be welded), the fitting end of the copper pipe is set in the mating section of the interface structure of the composite pipe, and the solder can be filled on the inner surface of the bent section and copper. Between the outer surfaces of the tubes, the contact between the solder and the end faces of the composite tube can be effectively avoided, thereby avoiding the contact of the phosphorus element in the solder with the steel tube body, that is, the phosphorus element in the solder is effectively isolated from the steel material of the composite tube, eliminating the present In the technology, the phosphorus element is incorporated into the steel material to cause lattice distortion, which improves the toughness and plasticity of the composite pipe after welding, thereby improving the service performance of the product.

Moreover, the weld bead is formed between the copper layer and the copper tube, and the flow property is not affected by the steel material when the solder melts, which is favorable for obtaining better fluidity and ensuring the quality of the weld bead.

In addition, the present invention also provides an interface structure of a composite pipe, comprising a steel pipe body, at least an outer surface of which is provided with a copper layer, and the end portion of the interface structure includes a bent section from the outside to the inside. And the fitting section, the inner diameter of the bending section is smaller than the inner diameter of the fitting section.

In addition, the present invention also provides a tube assembly comprising a welded jointed composite tube and a copper tube, the composite tube having the interface structure according to any one of the above, the interface structure being disposed inside the copper tube, And the mating segment is mated with the copper tube, and a partial weld is formed between the outer side of the bent portion and the inner surface of the copper tube.

When the composite pipe in this embodiment is welded and assembled with the copper pipe (or other material to be welded), the matching section of the interface structure of the composite pipe is set at the mating end of the copper pipe, and the joint portion of the solder from the composite pipe and the copper The gap between the corresponding outer surfaces of the tube flows inwardly, because the end of the composite tube has a bent portion that is bent inward, so that the molten solder flows only to the surface of the bent portion close to the mating portion, thereby effectively preventing the solder from coming into contact with the end surface of the composite tube, thereby Avoid the contact between the phosphorus element in the solder and the steel tube, that is, the phosphorus element in the solder is effectively isolated from the steel material of the composite tube, eliminating the lattice distortion caused by the integration of the phosphorus element into the steel material in the prior art, and improving the welding of the composite tube. After the toughness and plasticity, the product's performance is improved.

Since the tube assembly herein has the above interface structure, the tube assembly herein also has the above-described technical effects of the interface structure.

DRAWINGS

1 is a schematic view showing the assembly of a prior art copper tube and a copper-steel composite tube;

Figure 2 is a partial enlarged view of a portion A in Figure 1;

3 is a schematic view showing the assembly of a composite pipe and a pipe to be welded according to a first embodiment of the present invention;

Figure 4 is a partial enlarged view of E in Figure 3;

Figure 5 is a schematic structural view of a composite pipe in a second embodiment of the present invention;

Figure 6 is a schematic view showing the assembly of the composite pipe shown in Figure 5 and the pipe to be welded;

Figure 7 is a schematic structural view of a composite pipe in a third embodiment of the present invention;

Figure 8 is a schematic view showing the assembly of the composite pipe shown in Figure 7 and the pipe to be welded.

detailed description

In view of the technical problems of the deterioration of the welding section of the copper-copper composite pipe after the phosphor bronze brazing mentioned in the background art, this paper has conducted in-depth research. It is found that after the copper-steel composite pipe and the copper pipe are welded, the solder is mainly distributed in two regions: The outer wall of the copper pipe and the end face of the steel-copper composite pipe (zone A in Fig. 2) and the outer wall of the copper pipe and the inner wall of the copper-steel composite pipe and the root of the copper steel (zone B in Fig. 2). Phosphorus-copper solder on the end face of the steel-copper composite pipe is in contact with the copper layer and the steel main body at the same time. Among them, the phosphorus-copper solder has poor fluidity on the surface of the steel material, and the weld seam formation is difficult, resulting in the end face of the copper-steel composite pipe in the A zone. There are defects in the weld. At the same time, the phosphorus in the solder acts as a solute into the steel at the welding site, causing the lattice distortion at the end of the steel main body, increasing the resistance of the dislocation movement, making the slip difficult to perform, thereby making the strength of the copper-steel composite pipe The hardness increases, the toughness and plasticity decrease significantly, which affects the performance of the product.

Based on the above research findings, this paper further explores and then proposes a technical solution to solve the above technical problems, which is described in detail below.

In order to make those skilled in the art better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

Please refer to FIG. 3 and FIG. 4. FIG. 3 is a schematic view showing the assembly of the composite pipe and the pipe to be welded according to the first embodiment of the present invention; FIG. 4 is a partial enlarged view of the portion E of FIG.

The invention provides an interface structure of a composite pipe, as shown in FIG. 3, the composite pipe comprises steel The tube body 14 and the copper layer. The steel pipe body 14 described herein refers to an alloy containing a steel component or an elemental steel, and the alloy may be a copper steel alloy or an alloy of other metals and steel. Preferably, the copper steel alloy, i.e., the steel tubular body 14, may comprise one or more layers, each of which may be a copper steel alloy layer or a steel layer.

In this paper, the structure of several commonly used steel pipe bodies 14 is given. In the first structure, the steel pipe body may include a copper steel alloy layer, a steel layer and a copper steel alloy layer in a radial direction from the outside to the inside. In the second structure, the steel pipe body may include a copper steel alloy layer and a steel layer in a radial direction from the outside to the inside. In the third structure, the steel pipe body may include a steel layer and a copper alloy layer in a radial direction from the outside to the inside.

It should be noted that the direction of the central axis of the tube is defined as inner, and correspondingly, the direction away from the central axis of the tube is external.

In a specific embodiment, at least the inner surface of the steel pipe body 14 is provided with a copper layer 13, that is, the outer surface of the steel pipe body 14 may be provided with a copper layer 15 or may not be provided with a copper layer. The copper layer 13 mainly functions to isolate the steel pipe body 14 and the solder during welding, and to prevent corrosion. The solder used in the soldering herein is a phosphor bronze solder.

The end portion of the interface structure of the composite pipe herein includes a bending section 11 and a fitting section 12 in order from the outside to the inside. The fitting section 12 is mainly used for fitting with the pipe fitting 2 to be welded, and the forming section 12 and the pipe fitting 2 to be welded are formed. The solder accommodates the space to form the weld bead c. The inner diameter of the bent portion 11 herein is larger than the inner diameter of the engaging portion 12, that is, the bent portion 11 is an outwardly folded structure, wherein the length of the bent portion 11 can be set according to a specific environment. Taking the copper pipe to be welded as an example, continue to introduce technical solutions and technical effects.

When the composite pipe 1 is welded and assembled with the copper pipe 2 (or other material to be welded), the fitting end of the copper pipe 2 is fitted to the fitting section 12 of the interface structure of the composite pipe 1, and the solder can be filled in the bending. Between the inner surface of the segment 11 and the outer surface of the copper tube 2, the solder can be effectively prevented from contacting the end face 1a of the composite tube, thereby preventing the phosphorus element in the solder from contacting the steel tube 14, that is, the phosphorus element and the composite tube in the solder. The steel material of 1 is effectively isolated, eliminating the lattice distortion phenomenon of the phosphorus element incorporated into the steel material in the prior art, improving the toughness and plasticity of the composite pipe 1 after welding, thereby improving the service performance of the product.

Moreover, the weld bead is formed between the copper layer 13 and the copper tube 2. When the solder melts, the flow property is not affected by the steel material, which is favorable for obtaining better fluidity and ensuring the quality of the weld bead.

The pipe to be welded welded with the composite pipe herein is not limited to the copper pipe, and may also be a copper composite pipe.

Based on the first embodiment, the end of the interface structure is further improved, as follows.

Please refer to FIG. 5 and FIG. 6. FIG. 5 is a schematic structural view of a composite pipe according to a second embodiment of the present invention; FIG. 6 is a schematic view showing the assembly of the composite pipe and the pipe to be welded shown in FIG.

In the second embodiment, the interface structure in the foregoing embodiment may specifically include a main body segment 101 and a flared segment 100. The flared segment 100 is disposed at an end of the main body segment 101. As the name suggests, the inner diameter of the flared segment 100 is greater than The main body section 101, the bending section 11 and the fitting section 12 are disposed in the flared section.

Thus, the flared section 100 of the interface structure and the main body section 101 have different inner diameters, and the mating section of the copper tube 2 is disposed in the flared section 100, so that the joint position of the main body section 101 and the flared section 100 during the welding assembly is performed. It can play the role of assembly and positioning of the copper tube 2, which is beneficial to achieve rapid assembly and improve assembly efficiency.

The flared section 100 and the body section 101 in the above embodiment may be connected by a transition section, and the transition section may be a tapered connecting section, and the tapered connecting section from the outer to the inner is a tapered structure, that is, the interface structure includes A tapered connecting section that tapers from the outer to the inner diameter.

The bending section 11 in the above embodiment is a straight section and is surrounded by an flared bell mouth shape. The bent section 11 can also be a curved section.

Please refer to FIG. 7 and FIG. 8. FIG. 7 is a schematic structural view of a composite pipe according to a third embodiment of the present invention; FIG. 8 is a schematic view showing the assembly of the composite pipe and the pipe to be welded shown in FIG.

In a third embodiment, the composite pipe 1 also includes a steel pipe body and a copper layer. The steel pipe body is provided with a copper layer 16 on at least the outer surface thereof. Of course, the inner surface of the steel pipe body may also be provided with a copper layer. The end of the interface structure includes the bending section 11 and the fitting section 12 in order from the outside to the inside. The function of the engaging section is the same as that in the above embodiment, except that the inner diameter of the bending section 11 in this embodiment is smaller than the fitting section. The inner diameter, that is, the bending section 11 is bent inwardly, and may be a tapered section which is gradually expanded from the outer to the inner inner diameter. Of course, it can also be a curved segment.

When the composite pipe 1 in this embodiment is welded and assembled with the copper pipe 2 (or other material to be welded), the fitting section 12 of the interface structure of the composite pipe 1 is set at the mating end of the copper pipe 2, and the solder is self-compositing pipe. The gap between the mating section 12 of the 1 and the corresponding outer surface of the copper tube 2 flows inward, since the end of the composite tube 1 has a bent section 11 bent inward, so that the molten solder flows only to the bent section 11 The surface of the merging section effectively prevents the solder from coming into contact with the end face 1a of the composite pipe, thereby avoiding the contact of the phosphorus element in the solder with the steel pipe body, that is, the phosphorus element in the solder is effectively isolated from the steel material of the composite pipe, eliminating the prior art. Phosphorus is incorporated into the steel material to cause lattice distortion, which improves the toughness and plasticity of the composite pipe 1 after welding, thereby improving the performance of the product.

In this embodiment, the bending angle of the bending section 11 is generally greater than 0 and less than or equal to 180 degrees, and the length L1 of the bending section may be greater than or equal to the thickness δ1 of the composite pipe, and the bending angle may be reasonably selected according to the length of the bending section, as long as It is possible to realize that the solder does not flow to the end face of the composite pipe during soldering.

It is of course not excluded that the bending section has a plurality of crimping sections, that is, the bending angle is greater than 180 degrees.

Based on the first embodiment and the second embodiment, there is also provided a pipe assembly comprising a welded joint composite pipe 1 and a pipe to be welded, the composite pipe 1 having the first embodiment and In the interface structure of the second embodiment, the end portion of the pipe to be welded is fitted to the interface structure of the composite pipe and cooperates with the mating segment, and a part of the weld bead is formed between the inner side of the bent portion and the outer surface of the pipe member to be welded.

The pipe to be welded may be a copper pipe or a composite pipe. For example, the pipe to be welded may be a composite pipe in the third embodiment.

Based on the above third embodiment, there is further provided a tube assembly comprising a welded jointed composite tube 1 and a copper tube 2, the composite tube having any of the third embodiment. An interface structure, the interface structure is disposed inside the copper tube 2, and the mating segment is engaged with the copper tube, and a part of the weld bead is formed between the outer side of the bent portion and the inner surface of the copper tube .

The interface structure and tube assembly of a composite pipe provided by the present invention are described in detail above. The principles and embodiments of the present invention have been described herein with reference to specific examples, and the description of the above embodiments is only to assist in understanding the method of the present invention and its core idea. It should be noted that those skilled in the art can make various modifications and changes to the present invention without departing from the spirit and scope of the invention.

Claims

An interface structure of a composite pipe, the composite pipe (1) comprising a steel pipe body (14), the steel pipe body (14) having at least an inner surface provided with a copper layer, wherein the interface structure is The ends comprise, in order from the outside to the inside, a bending section (11) and a fitting section (12), the inner diameter of the bending section (11) being larger than the inner diameter of the fitting section (12).
The interface structure according to claim 1, wherein the interface structure comprises a main body segment (101) and a flared segment (100), and the flared segment (100) is disposed on the main body segment (101) The end portion, the bending portion (11) and the fitting portion (12) are disposed on the flared portion (100).
The interface structure according to claim 2, wherein said interface structure further comprises a tapered connecting section tapered from an outer to inner inner diameter, said main body section (101) being connected to said expanded by said tapered connecting section Mouth segment (100).
The interface structure according to any one of claims 1 to 3, wherein the angle of inclination of the bent section and the vertical direction is: greater than zero degrees and less than or equal to 360 degrees, and the bending section (11) The length is greater than or equal to the thickness of the composite pipe (1).
The interface structure according to any one of claims 1 to 3, characterized in that the bending section (11) is a straight section and is surrounded by an flared bell mouth shape.
An interface structure of a composite pipe, comprising a steel pipe body (14), wherein at least an outer surface of the steel pipe body (14) is provided with a copper layer, wherein the end portion of the interface structure is sequentially included from the outside to the inside. The bending section (11) and the fitting section (12), the inner diameter of the bending section (11) is smaller than the inner diameter of the fitting section (12).
The interface structure according to claim 6, wherein said steel pipe body (14) comprises at least one layer in the radial direction, each layer being an alloy layer or a steel layer of steel and other metals.
The interface structure according to any one of claims 6 or 7, wherein the angle of inclination of the bent section and the vertical direction is: greater than zero degrees and less than or equal to 360 degrees, and the bending section (11) The length is greater than or equal to the thickness of the composite pipe (1).
A pipe assembly comprising a welded jointed composite pipe (1) and a pipe to be welded, characterized in that the composite pipe (1) has the interface structure according to any one of claims 1 to 5, The end of the welded pipe fitting is fitted to the interface structure of the composite pipe (1) and cooperates with the fitting section (12), and a part of the weld bead is formed on the inner side of the bending section (11) and the pipe fitting to be welded Between the outer surfaces.
The pipe assembly according to claim 8, wherein the pipe member to be welded is a composite pipe (1), the composite pipe (1) having the interface structure according to any one of claims 6 to 8, A mating section (12) of a tube cooperates with a mating section (12) of the tube member to be welded.
A pipe assembly comprising a welded jointed composite pipe (1) and a copper pipe, characterized in that the composite pipe (1) has the interface structure according to any one of claims 6 to 8, the interface structure being The inside of the copper tube, and the mating section (12) is mated with the copper tube, and a partial weld is formed between the outer side of the bent section (11) and the inner surface of the copper tube.