Bent pipe and manufacturing method thereof

Abstract

An elbow and a method of manufacturing the same are provided. The bent pipe comprises an inner pipe and an outer pipe. The inner pipe is a gravity casting part and comprises a first inner bent part and a second inner bent part. And the first inner bending part and the second inner bending part have opposite bending directions. The outer pipe is a pressure casting part and comprises a first outer bent part and a second outer bent part. The first outer bent part wraps the first inner bent part and is integrated with the first inner bent part. The second outer bent part wraps the second inner bent part and is integrated with the second inner bent part. In this way, the bent pipe has good performance and low manufacturing cost.

Description

Technical Field

[0001] The present application relates to the field of manufacturing, and more specifically to a bent pipe and a manufacturing method thereof. Background Art

[0002] Chinese invention patent application CN109834241A discloses a sand core structure for high pressure casting of a supercharger intake elbow. The first side shaft core, the second side shaft core and the movable insert are assembled with each other. The first side shaft core and the second side shaft core are used to form the outer curved surface of the elbow, and the movable insert is used to form the inner curved surface of the elbow.

[0003] However, the cost of the above-mentioned sand core structure is relatively high. In order to enable the sand core blocks (i.e., the first side shaft core, the second side shaft core, and the movable insert) to be spliced ​​with each other, the sand core blocks need to be provided with a relatively complex splicing structure such as mounting holes, mounting bosses, fixing ports, and fixing pins. In addition, the sand core blocks need to have a high dimensional accuracy to ensure that there is no gap between the splicing interfaces of the sand core blocks, which further increases the cost of the sand core structure. Summary of the invention

[0004] The present application is made in view of the above-mentioned state of the prior art. The purpose of the present application is to provide a bent pipe and a manufacturing method thereof, which can overcome at least one of the disadvantages described in the above-mentioned background technology.

[0005] In order to achieve the above objectives, this application adopts the following technical solutions.

[0006] The present application provides a curved pipe as follows, comprising: an inner pipe, which is a gravity casting, the inner pipe comprising a first inner curved portion and a second inner curved portion, the first inner curved portion and the second inner curved portion having opposite bending directions; and an outer pipe, which is a pressure casting, the outer pipe comprising a first outer curved portion and a second outer curved portion, the first outer curved portion covering the first inner curved portion and forming an integral body with the first inner curved portion, the second outer curved portion covering the second inner curved portion and forming an integral body with the second inner curved portion.

[0007] In an optional solution, the first positioning portion and the second positioning portion formed on both side ends of the inner tube serve as positioning portions of the outer tube in the mold during die casting.

[0008] In another optional scheme, the inner tube also includes a first inner straight portion, a second inner straight portion and a third inner straight portion, the first inner straight portion is connected to the third inner straight portion via the second inner straight portion, the first inner curved portion and the second inner curved portion in sequence, and the outer tube also includes a first outer straight portion and a second outer straight portion, the first outer straight portion is connected to the second outer curved portion via the second outer straight portion and the first outer curved portion in sequence, the first outer straight portion covers the first inner straight portion and is formed as a whole with the first inner straight portion, and the second outer straight portion covers the second inner straight portion and is formed as a whole with the second inner straight portion.

[0009] In another optional scheme, the area of ​​the hollow cross-section of the first inner straight portion is smaller than the area of ​​the hollow cross-section of the second inner straight portion, the central axis of the first inner straight portion is the same as the central axis of the second inner straight portion, the area of ​​the hollow cross-section of the first outer straight portion is larger than the area of ​​the hollow cross-section of the second outer straight portion, and the central axis of the first outer straight portion is the same as the central axis of the second outer straight portion.

[0010] In another optional solution, the inner tube and the outer tube have flat oval cross-sections.

[0011] In another optional solution, the inner tube and the outer tube are made of aluminum alloy.

[0012] In another alternative, the inner tube is made of ZAlSi7Mg and / or the outer tube is made of AlSi10MnMg.

[0013] The present application also provides a method for manufacturing a bent pipe as follows, wherein the bent pipe is the bent pipe mentioned above, and the manufacturing method comprises: positioning a sand core in a first mold; obtaining the inner tube by gravity casting in the first mold; removing the inner tube from the first mold, with the sand core remaining in the inner tube; positioning the inner tube retaining the sand core in a second mold; obtaining the outer tube by pressure casting in the second mold, with the outer tube covering the inner tube and forming an integral body with the inner tube; removing the outer tube from the second mold; and removing the sand core from the inner tube.

[0014] In an optional solution, the method further includes: obtaining the sand core by additive manufacturing.

[0015] In another optional solution, positioning the inner tube in the second mold includes: allowing the second mold to clamp two end portions of the inner tube.

[0016] By adopting the above technical solution, by setting the inner tube and the outer tube, the bent pipe can be manufactured without using a complicated sand core or a slider, so that the bent pipe can have both good performance and low manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of a bent pipe according to an embodiment of the present application is shown.

[0018] Figure 2 Shows Figure 1 Schematic diagram of the inner tube of the elbow.

[0019] Figure 3 Shows Figure 1 Schematic diagram of the outer tube of the elbow.

[0020] Figure 4 Shows Figure 3 Cross-sectional view of the outer tube in FIG.

[0021] Figure 5 Shows Figure 1 Schematic diagram of a method for manufacturing an inner tube of a bent pipe.

[0022] Figure 6 Shows Figure 1 Schematic diagram of a method for manufacturing an outer tube of a bent pipe.

[0023] Description of Reference Numerals

[0024] 1. Bend pipe;

[0025] 11 inner tube; 111 first inner straight portion; 112 second inner straight portion; 113 third inner straight portion; 114 first inner curved portion; 115 second inner curved portion; 116 first positioning portion; 117 second positioning portion;

[0026] 12 outer tube; 121 first outer straight portion; 122 second outer straight portion; 123 first outer curved portion; 124 second outer curved portion;

[0027] 2 sand cores. DETAILED DESCRIPTION

[0028] The exemplary embodiments of the present application are described below with reference to the accompanying drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present application, and are not intended to exhaust all feasible methods of the present application, nor to limit the scope of the present application.

[0029] Figures 1 to 4 A curved pipe 1 according to an embodiment of the present application is shown, in particular, a curved pipe 1 for accommodating a wiring harness or for allowing a cooling fluid to flow.

[0030] Reference Figure 1 The bent pipe 1 may include an inner pipe 11 and an outer pipe 12 .

[0031] Reference Figure 2, the inner tube 11 may include a first inner straight portion 111, a second inner straight portion 112, a third inner straight portion 113, a first inner curved portion 114, and a second inner curved portion 115. Specifically, the first inner straight portion 111 may be connected to the third inner straight portion 113 via the second inner straight portion 112, the first inner curved portion 114, and the second inner curved portion 115 in sequence, that is, each portion may be arranged in series. One side end of the inner tube 11 may be formed by the first inner straight portion 111, and the other side end of the inner tube 11 may be formed by the third inner straight portion 113. The area of ​​the hollow cross-section of the first inner straight portion 111 may be smaller than the area of ​​the hollow cross-section of the second inner straight portion 112, and the central axis of the first inner straight portion 111 and the central axis of the second inner straight portion 112 may be the same. The second inner straight portion 112 may be smoothly connected to the first inner curved portion 114, and the third inner straight portion 113 may be smoothly connected to the second inner curved portion 115. The first inner curved portion 114 may be smoothly connected to the second inner curved portion 115 , and the first inner curved portion 114 and the second inner curved portion 115 may have opposite bending directions.

[0032] Reference Figure 3 and Figure 4 , the outer tube 12 may include a first outer straight portion 121, a second outer straight portion 122, a first outer curved portion 123, and a second outer curved portion 124. Specifically, the first outer straight portion 121 may be connected to the second outer curved portion 124 via the second outer straight portion 122 and the first outer curved portion 123 in sequence, that is, each portion may be arranged in series. One end portion of the outer tube 12 may be formed by the first outer straight portion 121, and the other end portion of the outer tube 12 may be formed by the second outer curved portion 124. Figure 4 As shown, the area of ​​the hollow cross-section of the first outer straight portion 121 may be greater than the area of ​​the hollow cross-section of the second outer straight portion 122, and the central axis of the first outer straight portion 121 and the central axis of the second outer straight portion 122 may be the same. The second outer straight portion 122 may be smoothly connected to the first outer curved portion 123. The first outer curved portion 123 may be smoothly connected to the second outer curved portion 124, and the first outer curved portion 123 and the second outer curved portion 124 may have opposite curvature directions.

[0033] Reference Figure 1, the outer tube 12 can cover the inner tube 11. Specifically, the cross-section of the inner tube 11 and the cross-section of the outer tube 12 can have the same shape (the size can be different), for example, both can have a flat oval cross-section. The inner tube 11 and the outer tube 12 can be made of aluminum alloy and formed as a whole. For example, in the present embodiment, the inner tube 11 can be made of ZAlSi7Mg (i.e., an aluminum alloy with a grade of ZL101), and the outer tube 12 can be made of AlSi10MnMg. In this way, the bent pipe 1 of the present application has good corrosion resistance. The first outer straight portion 121 can cover the first inner straight portion 111, and the second outer straight portion 122 can cover the second inner straight portion 112. The first outer curved portion 123 can cover the first inner curved portion 114, and the second outer curved portion 124 can cover the second inner curved portion 115. A portion of the first inner straight portion 111 can form a first positioning portion 116, and from one end of the outer tube 12 ( Figure 1 The entirety of the third inner straight portion 113 can form a second positioning portion 117, and extends from the other end ( Figure 1 The right end of the middle) extends out.

[0034] Figure 5 and Figure 6 The manufacturing method of the above-mentioned elbow 1 is shown, and the manufacturing method may include:

[0035] The sand core 2 is obtained by additive manufacturing, for example, the sand core 2 can be made by 3D printing;

[0036] Positioning the sand core 2 in a first mold (not shown);

[0037] The inner tube 11 is obtained by gravity casting in the first mold, that is, the inner tube 11 is a gravity casting part;

[0038] The inner tube 11 is removed from the first mold, and the sand core 2 is kept in the inner tube 11, so that the inner tube 11 and the sand core 2 are in Figure 5 The status shown;

[0039] Position the inner tube 11 holding the sand core 2 in a second mold (not shown in the figure), for example, the second mold can clamp the first positioning portion 116 and the second positioning portion 117, that is, the first positioning portion 116 and the second positioning portion 117 serve as positioning portions of the outer tube 12 in the second mold;

[0040] The outer tube 12 is obtained by pressure casting in the second mold, that is, the outer tube 12 is a pressure casting part;

[0041] Remove the outer tube 12 from the second mold so that the inner tube 11, the outer tube 12 and the sand core 2 are in Figure 6 the status shown; and

[0042] Remove the sand core 2 from the inner tube 11, so as to obtain Figure 1The elbow 1 is shown.

[0043] In this way, by providing the inner tube 11 and the outer tube 12, the elbow 1 can be manufactured without using a complex sand core or a slider, so that the elbow 1 can have both good performance and low manufacturing cost. In addition, by providing the first positioning portion 116 and the second positioning portion 117, the inner tube 11 is easily positioned in the second mold, thereby further reducing the manufacturing cost of the elbow 1.

[0044] Compared with welding, for example, the elbow of the present application is formed by gravity casting and pressure casting, which can avoid the problem of poor weld surface quality caused by welding, avoid or reduce the generation of pores, and reduce the risk of leakage. This is particularly important for the elbow used for cooling fluid flow.

[0045] In addition, if vacuum brazing is used to manufacture elbows, it will lead to an increase in cost and limit the brand of raw materials, etc. The solution of the present application can expand the application range of materials and processes, eliminate the limitation of vacuum brazing equipment, avoid leakage risks and save costs.

[0046] Gravity casting can avoid damage to the sand core and improve the yield rate. After gravity casting, the inner tube can withstand the pressure of pressure casting together with the sand core, which can ensure the smooth progress of pressure casting. Compared with gravity casting alone, since the outer tube is obtained by pressure casting, the quality of the bent tube, including the appearance quality, is high.

[0047] It should be understood that the above embodiments are merely exemplary and are not intended to limit the present application. Those skilled in the art may make various modifications and changes to the above embodiments under the guidance of the present application without departing from the scope of the present application.

[0048] It should be understood that the material of the elbow 1 of the present application is not limited to the examples given above, and the elbow may also be formed of other possible materials. The inner tube and the outer tube may be made of the same or different materials.

Claims

1. A pipe bend, characterized in that: include: An inner tube (11), which is a gravity casting, comprising a first inner curved portion (114) and a second inner curved portion (115), wherein the first inner curved portion (114) and the second inner curved portion (115) have opposite curvature directions; and The outer tube (12) is a pressure casting, and the outer tube (12) includes a first outer curved portion (123) and a second outer curved portion (124), wherein the first outer curved portion (123) covers the first inner curved portion (114) and is formed as a whole with the first inner curved portion (114), and the second outer curved portion (124) covers the second inner curved portion (115) and is formed as a whole with the second inner curved portion (115).

2. The elbow according to claim 1, characterized in that: The first positioning portion (116) and the second positioning portion (117) formed at both side ends of the inner tube (11) serve as positioning portions of the outer tube (12) in the mold during die casting.

3. The elbow according to claim 1 or 2, characterized in that: The inner tube (11) further comprises a first inner straight portion (111), a second inner straight portion (112) and a third inner straight portion (113), wherein the first inner straight portion (111) is connected to the third inner straight portion (113) via the second inner straight portion (112), the first inner curved portion (114) and the second inner curved portion (115) in sequence. The outer tube (12) further comprises a first outer straight portion (121) and a second outer straight portion (122); the first outer straight portion (121) is connected to the second outer curved portion (124) via the second outer straight portion (122) and the first outer curved portion (123) in sequence; the first outer straight portion (121) covers the first inner straight portion (111) and is formed as a whole with the first inner straight portion (111); the second outer straight portion (122) covers the second inner straight portion (112) and is formed as a whole with the second inner straight portion (112).

4. The elbow according to claim 3, characterized in that: The area of ​​the hollow cross section of the first inner straight portion (111) is smaller than the area of ​​the hollow cross section of the second inner straight portion (112), and the central axis of the first inner straight portion (111) is the same as the central axis of the second inner straight portion (112). The area of ​​the hollow cross-section of the first outer straight portion (121) is greater than the area of ​​the hollow cross-section of the second outer straight portion (122), and the central axis of the first outer straight portion (121) is the same as the central axis of the second outer straight portion (122).

5. The elbow according to claim 1 or 2, characterized in that: The inner tube (11) and the outer tube (12) have flat oval cross sections.

6. The elbow according to claim 1 or 2, characterized in that: The inner tube (11) and the outer tube (12) are made of aluminum alloy.

7. The elbow according to claim 6, characterized in that: The inner tube (11) is made of ZAlSi7Mg, and / or The outer tube (12) is made of AlSi10MnMg.

8. A method for manufacturing a bent pipe, wherein the bent pipe is the bent pipe according to any one of claims 1 to 7, characterized in that: The manufacturing method comprises: Positioning a sand core (2) in a first mold; Obtaining the inner tube (11) by gravity casting in the first mold; removing the inner tube (11) from the first mold, with the sand core (2) remaining in the inner tube (11); Positioning the inner tube (11) holding the sand core (2) in a second mold; The outer tube (12) is obtained by pressure casting in the second mold, wherein the outer tube (12) covers the inner tube (11) and is formed as a whole with the inner tube (11); removing the outer tube (12) from the second mold; and The sand core (2) is removed from the inner tube (11).

9. The manufacturing method according to claim 8, characterized in that: Also includes: The sand core (2) is obtained by additive manufacturing.

10. The manufacturing method according to claim 8 or 9, characterized in that: Positioning the inner tube (11) in the second mold comprises: The second mold is used to clamp both end portions of the inner tube (11).

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