Water expansion forming die for patterns on surface of stainless steel pipe fitting

Abstract

The utility model relates to the technical field of stainless steel pipe fitting machining, and discloses a stainless steel pipe fitting surface pattern water bulging forming die, and the diameter of a bulging steel pipe placed in the die is 80%-90% of the diameter of a final product; the mold comprises an upper mold assembly and a lower mold assembly, the upper mold assembly comprises an upper mold plate, a first heightening block, a first core rod seat and a sleeve, and the lower mold assembly comprises a lower mold plate, a second heightening block, a supporting plate, a cavity, a second core rod seat, a first spring clamp, a second spring clamp and a core rod. Before the die is used for bulging a product, weld joint polishing and bulging need to be carried out firstly, as the process adopted by the die is a one-time bulging process, the bulging amplitude is small, the weld joint is not prone to breakage, and the problem that one-time bulging is high and poor can be effectively solved.

Description

Technical Field

[0001] This utility model relates to the field of stainless steel pipe processing technology, and more specifically, to a hydraulic forming mold for surface patterns on stainless steel pipes. Background Technology

[0002] The forming processes for stainless steel cup body patterns are typically roll forming and hydroforming. Roll forming is difficult, and the pattern connection is hard to control. Ordinary hydroforming, if done in a single step, requires polishing the weld seam before forming to ensure a neat appearance. However, the large expansion range during a single step makes the weld seam prone to cracking, resulting in high defects and costs. Two-step expansion is possible: first polishing the weld seam, then expanding to 80%–90% of the product diameter, and finally expanding the surface pattern and the final product diameter. However, this two-step expansion method involves more steps and higher costs.

[0003] Therefore, it is necessary to provide a mold that can achieve one-time forming while solving the problems of easy cracking at the weld, high defect rate, and high cost caused by one-time forming. Utility Model Content

[0004] In view of this, the present invention proposes a hydraulic expansion forming mold for surface patterns on stainless steel pipe fittings, the specific technical solution of which is as follows:

[0005] A hydraulic forming mold for surface patterns on stainless steel pipe fittings, wherein the diameter of the bulging steel pipe placed in the mold is 80% to 90% of the diameter of the final product; the mold includes an upper mold assembly and a lower mold assembly;

[0006] The upper mold assembly includes an upper template, a first lifting block, a first mandrel seat, and a sleeve. The first lifting block is fixedly connected to the lower part of the upper template, and the sleeve is fixedly connected to the lower part of the first lifting block. The first mandrel seat has a horizontally extending end on its top, and the first end cooperates with a circular limiting groove on the upper inner side of the first lifting block to form a limiting position of the first mandrel seat within the first lifting block.

[0007] The lower mold assembly includes a lower template, a second lifting block, a support plate, a cavity, a second mandrel seat, a first spring clip, a second spring clip, and a mandrel. The second lifting block is fixed above the lower template and is an integral structure divided into three segments from bottom to top: segment one, segment two, and segment three. Segment one has the largest outer diameter, and segment two has the smallest outer diameter. The support plate is installed on the outer ring of segment two and supported by the top surface of segment one. Several cavities are provided and arranged circumferentially to form a whole. A sleeve is fitted onto the outside of the cavity, and the bottom end of the cavity is embedded in the space formed between the top surface of the support plate and the bottom surface of segment three. When the upper mold assembly presses down to close the mold, the sleeve... The cavity is radially contracted inward under the cooperation, and the inner surface of the cavity is provided with a processing pattern; the bottom of the second mandrel seat is provided with a horizontally extending end two, which cooperates with the circular limiting groove two at the lower part of the second raising block to form a limiting position of the second mandrel seat within the second raising block; the lower end of the first mandrel seat is fitted into the first spring clip, and the upper end of the second mandrel seat is fitted into the second spring clip, and the mandrel is fixed between the first and second spring clips in the upper and lower positions; the lower template, the second mandrel seat, the second spring clip, and the mandrel are provided with interconnected water inlet channels, and the mandrel is provided with a through hole communicating with the internal space of the cavity.

[0008] Preferably, the bulging range of the bulging steel pipe is 10-20% larger than the pipe section diameter.

[0009] Preferably, the upper template, the heightening block, and the sleeve are connected and fixed by a number of screws.

[0010] Preferably, the lower template and the second heightening block are connected and fixed by a number of screws.

[0011] Preferably, the pattern on the inner surface of the cavity is a concave pattern or a convex pattern.

[0012] Preferably, the thickness of the first end is less than the depth of the first circular limiting groove, and the thickness of the second end is less than the depth of the second circular limiting groove.

[0013] Preferably, the outer surface of the cavity is provided with an inclined surface that matches the inner wall of the sleeve.

[0014] Preferably, during installation, the upper template and the lower template are respectively locked and limited by locking angle irons installed on the upper and lower expansion machine mold fixing plates, and each locking angle iron is fixed to the expansion machine mold fixing plate by its corresponding screws.

[0015] Compared with the prior art, the process adopted by the stainless steel pipe surface pattern water expansion forming mold of this utility model is a one-time expansion process. The diameter of the expanded steel pipe placed in the mold is about 80%-90% of the diameter of the final product. The material thickness of the expanded steel pipe can be selected from the material thickness after expansion of normal material (amplitude 30% to 35%), thereby reducing material costs.

[0016] Before using the mold of this utility model to bulge products, the weld seam needs to be polished first, and then bulging is performed. Since the bulging range of the mold of this utility model is small, the weld seam is not easy to break, thus effectively solving the problem of high defects in one bulging. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of a stainless steel pipe surface pattern hydroforming mold according to the present invention.

[0019] Figure 2 This is a schematic diagram of the upper mold assembly in the mold of this utility model.

[0020] Figure 3 This is a schematic diagram of the lower mold assembly in the mold of this utility model.

[0021] Figure 4 This is a schematic diagram of the cavity structure in the mold of this utility model.

[0022] Figure 5 This is a schematic diagram of the installation of the upper mold component in the mold of this utility model.

[0023] Figure 6 This is a schematic diagram of the installation of the lower mold assembly in the mold of this utility model.

[0024] Figure 7 This is a diagram showing the state of inserting the bulging steel pipe into the lower mold assembly according to this utility model.

[0025] Figure 8 This is a diagram showing the state of the present invention during mold closing and expansion.

[0026] Figure 9 This is a diagram showing the state of the product during mold opening and product removal for this utility model.

[0027] Figure 10This is a schematic diagram showing the product shape, steel pipe diameter, and mold cavity dimensions of a specific embodiment of the present invention.

[0028] In the diagram: 1-Upper template, 2-Elevator block one, 3-Mandrel seat one, 4-Sleeve, 5-Template, 6-Elevator block two, 7-Support plate, 8-Cavity, 9-Mandrel seat two, 10-Spring clip one, 11-Spring clip two, 12-Mandrel, 13-End one, 14-Circular limiting groove one, 15-Segment one, 16-Segment two, 17-Segment three, 18-Processed pattern, 19-End two, 20-Circular limiting groove two, 21-Water inlet channel, 22-Through hole, 23-Screw one, 24-Screw two, 25-Expanded steel pipe, 26-Expanding machine mold fixing plate, 27-Mold locking angle iron, 28-Screw three, 29-Expanded product. Detailed Implementation

[0029] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0030] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0032] Example:

[0033] See Figure 1 This embodiment provides a stainless steel pipe surface pattern hydroforming mold, wherein the diameter of the bulging steel pipe 25 placed in the mold is 80% to 90% of the final product diameter. The bulging steel pipe 25 is first welded, and then the bulging steel pipe 25 is bulged to the final product diameter and the surface pattern is formed by a one-time bulging process.

[0034] The stainless steel pipe fitting surface pattern hydroforming mold specifically includes an upper mold assembly and a lower mold assembly.

[0035] Among them, see Figure 2 The upper mold assembly includes an upper template 1, an increasing block 2, a mandrel seat 3, and a sleeve 4. The increasing block 2 is fixedly connected to the lower part of the upper template 1, and the sleeve 4 is fixedly connected to the lower part of the increasing block 2. The top of the mandrel seat 3 is provided with a horizontally extending end 13, which cooperates with the circular limiting groove 14 on the upper inner side of the increasing block 2 to form a limiting position of the mandrel seat 3 within the increasing block 2.

[0036] The upper template 1, the heightening block 2, and the sleeve 4 are connected and fixed by several screws 23.

[0037] See Figure 3 , Figure 4 The lower mold assembly includes a lower mold plate 5, a second lifting block 6, a support plate 7, a cavity 8, a second mandrel seat 9, a first spring clip 10, a second spring clip 11, and a mandrel 12. The second lifting block 6 is fixed above the lower mold plate 5. Specifically, the lower mold plate 5 and the second lifting block 6 are connected and fixed by several screws 24. The second lifting block 6, which is an integral structure, is divided into three sections from bottom to top: section 15, section 26, and section 37. Section 15 has the largest outer diameter, and section 26 has the smallest outer diameter. The support plate 7 is installed on the outer ring of section 26 and supported by the top surface of section 15. There are several cavities 8 arranged circumferentially to form a whole. The sleeve 4 is fitted onto the outside of the cavity. The bottom end of the cavity 8 is embedded in the space formed between the top surface of the support plate 7 and the bottom surface of section 37. The outer surface of the cavity 8 has a bevel that matches the inner wall of the sleeve 4. When the upper mold assembly is pressed down to close the mold, the sleeve 4, in cooperation with the inclined surface of the cavity 8, causes the cavity 8 to radially retract inward. The inner surface of the cavity 8 is provided with a processing pattern 18, which is a concave pattern or a convex pattern. The bottom of the mandrel seat 2 9 is provided with a horizontally extending end 2 19, which cooperates with the circular limiting groove 20 at the lower part of the raising block 2 6 to form a limiting position of the mandrel seat 2 9 within the raising block 2 6. The lower end of the mandrel seat 1 3 is fitted into the spring clip 1 10, and the upper end of the mandrel seat 2 9 is fitted into the spring clip 2 11. The mandrel 12 is fixed between the spring clip 1 10 and the spring clip 2 11 in the upper and lower positions. The lower mold plate 5, the mandrel seat 2 9, the spring clip 2 11, and the mandrel 12 are provided with a connected water inlet channel 21, and the mandrel 12 is provided with a through hole 22 that communicates with the internal space of the cavity 8.

[0038] In this utility model mold, the bulging range of the bulging steel pipe 25 is 10-20% larger than the pipe section diameter. The bulging steel pipe is first welded, and then bulged once using this utility model mold. Because the bulging range using this utility model mold is small, the weld is less prone to cracking, thus effectively solving the problem of high defects in single-stage bulging. Simultaneously, the material thickness of the bulging steel pipe 25 can be selected from the thickness of normal material after bulging (30%-35% range), thereby effectively reducing material costs.

[0039] In this utility model mold, the thickness of end 13 is less than the depth of the circular limiting groove 14, and the thickness of end 19 is less than the depth of the circular limiting groove 20. The functions of the first and second heightening blocks 2 and 6 are to fix the mandrel seat and to adjust the mold during the length adjustment of the bulging steel tube. The first and second spring clips 10 and 11 are used to fix the bulging steel tube 25 and the mandrel 12. The mandrel seat is used to cooperate with the spring clips to fix the bulging steel tube 25.

[0040] The sleeve 4 in this mold is used to enclose the cavity 8, preventing it from opening during bulging. The cavity 8 is used to control the product size and pattern. The through hole 22 on the mandrel 12 also allows for faster water flow within the cavity 8 during bulging, resulting in faster and more uniform water pressure. The support plate 7 is used to support the cavity 8 when it opens.

[0041] In this utility model mold, the upper template 1 is used to lock the upper mold assembly onto the forming machine table, and the lower template 5 is used to lock the lower mold assembly onto the forming machine table. Specifically, as follows: Figure 5 , Figure 6 As shown, during installation, the upper template 1 and the lower template 5 are respectively locked and limited by the locking angle irons 27 installed on the upper and lower expansion machine mold fixing plates 26, and each locking angle iron 27 is fixed to the expansion machine mold fixing plate 26 by its corresponding screws 28.

[0042] The working steps of this utility model mold are as follows:

[0043] (1) As Figure 7 As shown, the bulging steel tube 25 is inserted into the lower mold assembly;

[0044] (2) Figure 8 As shown, mold closing and bulging;

[0045] Water from the water inlet A of the water inlet channel 21 is injected into the mold. Through the pressurization of the machine, the steel pipe expands outward under the action of water pressure and fits tightly into the cavity 8 until the pattern on the whole surface is formed, achieving the required expansion size and pattern, and completing the whole pattern processing in one go.

[0046] (3) Figure 9 As shown, the mold is opened and the expanded product 29 is taken out.

[0047] In one specific embodiment, such as Figure 10 As shown, if the required diameter of the bulging product 29 is 80.4mm (d1), then the diameter of the bulging steel pipe should be 77mm (d2). The mold cavity should not rebound, and the cavity diameter (d3) should be the same as the product diameter, which is 80.4mm.

[0048] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0049] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A hydraulic forming mold for surface patterns on stainless steel pipe fittings, characterized in that, The diameter of the bulging steel tube placed in the mold is 80% to 90% of the diameter of the final product; the mold includes an upper mold assembly and a lower mold assembly; The upper mold assembly includes an upper template, a first lifting block, a first mandrel seat, and a sleeve. The first lifting block is fixedly connected to the lower part of the upper template, and the sleeve is fixedly connected to the lower part of the first lifting block. The first mandrel seat has a horizontally extending end on its top, and the first end cooperates with a circular limiting groove on the upper inner side of the first lifting block to form a limiting position of the first mandrel seat within the first lifting block. The lower mold assembly includes a lower template, a second lifting block, a support plate, a cavity, a second mandrel seat, a first spring clip, a second spring clip, and a mandrel. The second lifting block is fixed above the lower template and is an integral structure divided into three segments from bottom to top: segment one, segment two, and segment three. Segment one has the largest outer diameter, and segment two has the smallest outer diameter. The support plate is installed on the outer ring of segment two and supported by the top surface of segment one. Several cavities are provided and arranged circumferentially to form a whole. A sleeve is fitted onto the outside of the cavity, and the bottom end of the cavity is embedded in the space formed between the top surface of the support plate and the bottom surface of segment three. When the upper mold assembly presses down to close the mold, the sleeve... The cavity is radially contracted inward under the cooperation, and the inner surface of the cavity is provided with a processing pattern; the bottom of the second mandrel seat is provided with a horizontally extending end two, which cooperates with the circular limiting groove two at the lower part of the second raising block to form a limiting position of the second mandrel seat within the second raising block; the lower end of the first mandrel seat is fitted into the first spring clip, and the upper end of the second mandrel seat is fitted into the second spring clip, and the mandrel is fixed between the first and second spring clips in the upper and lower positions; the lower template, the second mandrel seat, the second spring clip, and the mandrel are provided with interconnected water inlet channels, and the mandrel is provided with a through hole communicating with the internal space of the cavity.

2. The stainless steel pipe fitting surface pattern hydroforming mold according to claim 1, characterized in that, The bulging range of the bulging steel pipe is 10-20% increase in the pipe section diameter.

3. The stainless steel pipe fitting surface pattern hydroforming mold according to claim 1, characterized in that, The upper template, the heightening block, and the sleeve are connected and fixed by several screws.

4. The stainless steel pipe fitting surface pattern hydroforming mold according to claim 1, characterized in that, The lower template and the second heightening block are connected and fixed by several screws.

5. The stainless steel pipe fitting surface pattern hydroforming mold according to claim 1, characterized in that, The machining pattern on the inner surface of the cavity is a concave pattern or a convex pattern.

6. The stainless steel pipe fitting surface pattern hydroforming mold according to claim 1, characterized in that, The thickness of the first end is less than the depth of the first circular limiting groove, and the thickness of the second end is less than the depth of the second circular limiting groove.

7. The stainless steel pipe fitting surface pattern hydroforming mold according to claim 1, characterized in that, The outer surface of the cavity is provided with an inclined surface that matches the inner wall of the sleeve.

8. A stainless steel pipe fitting surface pattern hydroforming mold according to any one of claims 1-7, characterized in that, During installation, the upper template and the lower template are respectively locked and limited by the locking angle irons installed on the upper and lower expansion machine mold fixing plates, and each of the locking angle irons is fixed to the expansion machine mold fixing plate by its corresponding screws.

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