Water expansion forming die and water expansion forming machine

Abstract

The utility model discloses a water expansion forming die which comprises a first die, a second die, a third die, a fourth die and a fifth die, a first positioning shaft, a second positioning shaft, a first transition die, a first movable die and a plurality of first die pieces are arranged in the first die, the first die pieces are arranged at intervals in the left-right direction, and the first positioning shaft sequentially penetrates through the first transition die and the first die pieces and is connected with the first movable die. A plurality of first annular steps are arranged on the outer side of the first positioning shaft in the axial direction, the first annular steps abut against the left sides of the first mold pieces respectively, the second positioning shaft penetrates through the first mold pieces, a plurality of second annular steps are arranged on the outer side of the second positioning shaft in the axial direction, and the second annular steps abut against the right sides of the first mold pieces respectively; when the first die abuts against the second die, a first corrugation forming cavity is formed between the second die and the first die pieces, the corrugated pipe production cost is reduced, and the production flexibility and convenience are improved.

Description

Technical Field

[0001] This utility model relates to a mold structure, and more particularly to a water-expansion molding mold and a water-expansion molding machine. Background Technology

[0002] There are various methods for producing corrugated pipes, such as the hydroforming method. Specifically, the pipe to be formed is placed in a forming mold. The mold has pre-set forming grooves according to the required corrugation size and spacing. The pipe is positioned within these grooves, and under water pressure, it expands within the grooves to form the desired shape. When producing different corrugated pipes, the entire forming mold needs to be replaced, and the production cost of the forming mold is relatively high, thus increasing the overall production cost of the corrugated pipes. Therefore, there is an urgent need for a hydroforming mold that can reduce the production cost of different corrugated pipes. Utility Model Content

[0003] The purpose of this utility model is to provide a water-expansion molding mold and a water-expansion molding machine to solve one or more technical problems existing in the prior art, and at least provide a beneficial option or create conditions.

[0004] The solution to the technical problem of this utility model is:

[0005] A water-expanding molding die includes: a first die, internally provided with a first positioning shaft, a second positioning shaft, a first transition die, a first movable die, and first die pieces; multiple first die pieces are spaced apart along the left-right direction; the first positioning shaft passes sequentially through the first transition die and the multiple first die pieces and connects to the first movable die; multiple first annular steps are axially arranged on the outer side of the first positioning shaft, the outer radial direction of the multiple first annular steps decreasing sequentially to the right; the multiple first annular steps abut against the left side of the multiple first die pieces; a second positioning shaft passes through the multiple first die pieces; multiple second annular steps are axially arranged on the outer side of the second positioning shaft, the outer radial direction of the multiple second annular steps decreasing sequentially to the left; the multiple second annular steps abut against the right side of the multiple first die pieces; and a second die, which can be relatively close to or far from the first die; when the first die abuts against the second die, a first corrugated molding cavity is formed between the second die and the multiple first die pieces.

[0006] This technical solution has at least the following beneficial effects: Multiple first mold pieces for forming corrugations are arranged within the first mold. These first mold pieces abut against each other on the left side using first annular steps of different outer diameters on the first positioning shaft, thus providing support and positioning on the left side of the multiple first mold pieces. Additionally, second annular steps of different outer diameters on the second positioning shaft abut against the right side of the multiple first mold pieces, thus providing support and positioning on the right side of the multiple first mold pieces. During production, the pipe to be formed is placed between the first mold and the second mold. The first mold and the second mold approach and abut against each other, forming a first corrugated forming cavity between the second mold and the multiple first mold pieces. Water is injected and pressurized into the pipe, causing it to initially expand and form between the multiple spaced-apart first mold pieces. Then, the first movable mold moves to the left, driving the first positioning shaft to move to the left. The first movable mold pushes the multiple first mold pieces towards the first transition mold on the left, causing the first movable mold and the multiple first mold pieces to... The mold pieces and the first transition mold are close to each other. At this time, the formed initial wave is squeezed into the first corrugated forming cavity, and the water expansion pressure on the pipe is further increased, so that the pipe wall fits with multiple first mold pieces, fixes the waveform, and completes the corrugation. Then, the first positioning shaft moves to the right, and multiple first annular steps on the outside of the first positioning shaft push the multiple first mold pieces apart at intervals. Finally, the right sides of the multiple first mold pieces abut against multiple second annular steps to reset at intervals. Since the required corrugated forming cavity is formed by arranging and positioning multiple first mold pieces at intervals using the first positioning shaft and the second positioning shaft, when different shapes of corrugated pipes need to be produced, it is only necessary to recombine or replace the first positioning shaft, the second positioning shaft and multiple first mold pieces according to the shape of the corrugated pipe. In this way, it is not necessary to replace the entire water expansion forming mold, which reduces production costs and improves production flexibility and convenience.

[0007] As a further improvement to the above technical solution, there are two second positioning shafts, each located on one side of the first positioning shaft. The two second positioning shafts abut against the right side of the first mold piece using their outer second annular steps, and the first positioning shaft abuts against the left side of the first mold piece using its outer first annular step. This greatly improves the clamping and positioning effect on the first mold piece.

[0008] As a further improvement to the above technical solution, the centerline of the first positioning axis and the centerline of the second positioning axis are located on the same straight line. The forces exerted by the first positioning axis and the two second positioning axes on the first module for positioning are on the same straight line, which can reduce the space occupied and ensure the stability of positioning the first module.

[0009] As a further improvement to the above technical solution, a second mold piece and a first fixed mold are sequentially arranged on the left side of the first transition mold inside the first mold. Multiple second mold pieces are spaced apart in the left-right direction. The first positioning shaft passes through the first fixed mold and the multiple second mold pieces. Multiple third annular steps are arranged axially on the outside of the first positioning shaft. The outer radial direction of the multiple third annular steps decreases sequentially to the right. The multiple third annular steps abut against the left side of the multiple second mold pieces. The second positioning shaft passes through the multiple second mold pieces and is connected to the first fixed mold. Multiple fourth annular steps are arranged axially on the outside of the second positioning shaft. The multiple fourth annular steps abut against the right side of the multiple second mold pieces. When the first mold abuts against the second mold, a second corrugated forming cavity is formed between the second mold and the multiple second mold pieces. When the first mold and the second mold abut against each other, a second corrugated forming cavity is formed between the multiple second mold pieces and the second mold. At this time, the pipe can form a second corrugation at this position. Specifically, water is injected into the pipe and pressurized. The pipe first undergoes preliminary water expansion between the multiple spaced second mold pieces. Then, the first transition mold moves to the left, pushing the multiple second mold pieces towards the first fixed mold on the left side, so that the first transition mold, the multiple second mold pieces, and the first fixed mold are close to each other. At this time, the formed initial wave is squeezed into the second corrugated forming cavity, and the water expansion pressure on the pipe is further increased, so that the pipe wall fits with the multiple second mold pieces, fixing the waveform and completing the corrugation. Then, the first positioning shaft moves to the right, and the multiple third annular steps on the outside of the first positioning shaft push the multiple second mold pieces apart at intervals. Finally, the right sides of the multiple second mold pieces abut against the multiple fourth annular steps to reset at intervals. In this way, multiple corrugations can be formed on the same pipe according to different production needs.

[0010] As a further improvement to the above technical solution, the first mold includes a first linear drive, a first mold base, and a second fixed mold. The first linear drive is connected to the left side of the first fixed mold. The first fixed mold and the second fixed mold are respectively connected to the first mold base. The second fixed mold is located on the right side of the first movable mold. The movable end of the first linear drive passes through the first fixed mold and is connected to the first positioning shaft. A first through groove extending in the left-right direction is provided in the second fixed mold. The first fixed mold and the second fixed mold are respectively fixed on the first mold base. The first linear drive is mounted on the first fixed mold and provides a driving force for the first positioning shaft to move in the left-right direction. The second fixed mold is provided with a first through groove to provide clearance for the external drive. When it is necessary to bring multiple first mold pieces closer together to close the mold, the external drive can pass through the first through groove to press against the first movable mold and push the first movable mold to the left, so that the first movable mold presses against the first mold pieces to the left, so that the multiple first mold pieces are in contact with each other. When it is necessary to separate the multiple first mold pieces, the first linear drive drives the first positioning shaft to move to the right, thereby pushing the multiple first mold pieces to the right in sequence at intervals.

[0011] As a further improvement to the above technical solution, this utility model also includes a water injection head and a plug. The water injection head can be inserted to the right into the first fixed mold and connect the first corrugated forming cavity and the second corrugated forming cavity. The plug can pass through the second fixed mold to the left and press against the first movable mold. When the first mold and the second mold are closed, the first water injection head is inserted into one end of the pipe, and the plug is inserted into the other end of the pipe. At this time, high-pressure water can be introduced into the pipe from the first water injection head, and the plug seals the other end of the pipe, causing the pipe to expand and form with water inside. When it is necessary to fit multiple first mold pieces together, the plug pushes the first movable mold to the left, so that the multiple first mold pieces fit together.

[0012] As a further improvement to the above technical solution, the first positioning shaft is detachably connected to the first movable mold, and the second positioning shaft is detachably connected to the second fixed mold. The first positioning shaft can be removed from the first movable mold, and then multiple first mold pieces, a first transition mold, multiple second mold pieces, and the first fixed mold can be removed to replace the first positioning shaft. Similarly, the second positioning shaft can be removed from the second fixed mold, and then multiple second mold pieces, a first transition mold, multiple first mold pieces, and the first movable mold can be removed to replace the second positioning shaft.

[0013] As a further improvement to the above technical solution, a guide post is connected between the first fixed mold and the second fixed mold. The guide post passes through the first movable mold, the plurality of first mold pieces, the first transition mold, and the plurality of second mold pieces. When the first movable mold, the plurality of first mold pieces, the first transition mold, and the plurality of second mold pieces move relatively left and right, they are guided by the guide post, which can improve the stability of the first movable mold, the plurality of first mold pieces, the first transition mold, and the plurality of second mold pieces during relative sliding.

[0014] As a further improvement to the above technical solution, the structure of the second mold is symmetrical to that of the first mold. Similarly, the second mold has a structure in which positioning shafts position multiple mold pieces at intervals, thereby forming a corrugated pattern when it is closed with the first mold, improving the convenience of changing the mold pieces within the second mold.

[0015] A hydroforming machine includes the aforementioned hydroforming mold.

[0016] The technical solution has at least the following beneficial effects: In this hydroforming machine, due to the aforementioned hydroforming mold, when it is necessary to produce corrugated pipes of different shapes, it is only necessary to recombine or replace the first positioning shaft, the second positioning shaft and multiple first mold pieces according to the shape of the corrugated pipe. In this way, it is not necessary to replace the entire hydroforming mold, which reduces production costs and improves the flexibility and convenience of production. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly explained below. Obviously, the described drawings are only a part of the embodiments of this utility model, and not all of them. Those skilled in the art can obtain other design schemes and drawings based on these drawings without creative effort.

[0018] Figure 1 This is a front view of the water-expanding molding die of this utility model.

[0019] Figure 2 yes Figure 1 A schematic diagram of the AA cross-sectional structure.

[0020] Figure 3 yes Figure 1 A schematic diagram of the BB cross-sectional structure.

[0021] Figure 4 yes Figure 3 A magnified view of part C.

[0022] In the attached diagram: 100-First mold, 110-First positioning shaft, 111-First annular step, 120-Second positioning shaft, 121-Second annular step, 130-First transition mold, 140-First movable mold, 150-First mold piece, 160-Second mold piece, 170-First linear drive component, 180-First mold base, 191-First fixed mold, 192-Second fixed mold, 193-Guide post, 200-Second mold, 310-Water injection head, 320-Plug. Detailed Implementation

[0023] 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 are only used to explain this utility model, and should not be construed as limiting this utility model.

[0024] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional 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.

[0025] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is used in the description, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0026] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0027] Reference Figures 1 to 4A water-expanding molding die includes a first die 100 and a second die 200. The first die 100 internally houses a first positioning shaft 110, a second positioning shaft 120, a first transition die 130, a first movable die 140, and first die pieces 150. Multiple first die pieces 150 are spaced apart along a left-right direction. The first positioning shaft 110 sequentially passes through the first transition die 130 and the multiple first die pieces 150, connecting to the first movable die 140. Multiple first annular steps 111 are axially arranged on the outer side of the first positioning shaft 110, with the outer radial direction of the multiple first annular steps 111 decreasing progressively to the right. The multiple first annular steps 111 abut against the left side of the multiple first die pieces 150. The second positioning shaft 120 passes through the multiple first die pieces 150, and its outer side is axially arranged... A plurality of second annular steps 121 are provided, the outer radial diameter of the plurality of second annular steps 121 decreasing sequentially to the left, and the plurality of second annular steps 121 respectively abut against the right side of the plurality of first mold pieces 150; the second mold 200 can be relatively close to or far from the first mold 100. When the first mold 100 abuts against the second mold 200, a first corrugated forming cavity is formed between the second mold 200 and the plurality of first mold pieces 150. In practical applications, when the first mold 100 and the second mold 200 abut against each other and close, a tube forming cavity is formed between the two. At this time, the first corrugated forming cavity is a part of the tube forming cavity. The first mold piece 150 located in the first corrugated forming cavity will be provided with a corrugated forming structure, so that when the two first mold pieces 150 are attached to each other, a corrugated forming cavity can be formed on the outer wall of the tube.

[0028] As described above, a plurality of first mold pieces 150 for forming corrugations are provided in the first mold 100. These first mold pieces 150 abut against each other on the left side using first annular steps 111 of different outer diameters on the first positioning shaft 110, thereby providing support and positioning on the left side of the plurality of first mold pieces 150. Additionally, second annular steps 121 of different outer diameters on the second positioning shaft 120 abut against the right side of the plurality of first mold pieces 150, thereby providing support and positioning on the right side of the plurality of first mold pieces 150. During production, the pipe to be formed is placed in... Between the first mold 100 and the second mold 200, the first mold 100 and the second mold 200 approach and abut against each other, forming a first corrugated forming cavity between the second mold 200 and multiple first mold pieces 150. Water is injected and pressurized into the pipe, and the pipe undergoes preliminary hydroforming between the multiple spaced first mold pieces 150. Then, the first movable mold 140 moves to the left, driving the first positioning shaft 110 to move to the left. The first movable mold 140 pushes the multiple first mold pieces 150 towards the first transition mold 130 on the left, so that the first movable mold 100... 40. Multiple first mold pieces 150 and first transition mold 130 are close to each other. At this time, the formed initial wave is squeezed into the first corrugated forming cavity, and the water expansion pressure on the pipe is further increased, so that the pipe wall fits with multiple first mold pieces 150, fixes the waveform, and completes the corrugation. Then, the first positioning shaft 110 moves to the right, and multiple first annular steps 111 on the outside of the first positioning shaft 110 push the multiple first mold pieces 150 apart at intervals. Finally, the right sides of multiple first mold pieces 150 abut against multiple second annular steps 121 at intervals and reset. Since the first positioning shaft 110 and the second positioning shaft 120 are used to position multiple first mold pieces 150 at intervals to form the required corrugated forming cavity, when different shapes of corrugated pipes need to be produced, it is only necessary to recombine or replace the first positioning shaft 110, the second positioning shaft 120 and multiple first mold pieces 150 according to the shape of the corrugated pipe. In this way, it is not necessary to replace the entire water expansion forming mold, which reduces production costs and improves production flexibility and convenience.

[0029] To improve the stability of positioning the first mold piece 150, in this embodiment, there are two second positioning shafts 120, located on opposite sides of the first positioning shaft 110. The two second positioning shafts 120 abut against the right side of the first mold piece 150 using their outer second annular steps 121, and the first positioning shaft 110 abuts against the left side of the first mold piece 150 using its outer first annular steps 111. This greatly improves the clamping and positioning effect on the first mold piece 150.

[0030] Furthermore, the center line of the first positioning axis 110 and the center line of the second positioning axis 120 are located on the same straight line. The forces exerted by the first positioning axis 110 and the two second positioning axes 120 on the first module 150 for positioning are on the same straight line, which can reduce the space occupied and ensure the stability of positioning the first module 150.

[0031] Multiple first mold pieces 150 are combined to form a module for forming corrugations. When multiple corrugations need to be formed on the pipe, multiple corrugation forming molds need to be set in the first mold 100. Specifically, a second mold piece 160 and a first fixed mold 191 are sequentially arranged in the first mold 100 to the left of the first transition mold 130. Multiple second mold pieces 160 are spaced apart in the left-right direction. The first positioning shaft 110 passes through the first fixed mold 191 and multiple second mold pieces 160. Multiple third annular steps are arranged axially on the outer side of the first positioning shaft 110. The outer radial direction of each of the third annular steps gradually decreases to the right. The third annular steps abut against the left side of the second mold pieces 160 respectively. The second positioning shaft 120 passes through the second mold pieces 160 and is connected to the first fixed mold 191. The outer side of the second positioning shaft 120 is provided with a plurality of fourth annular steps along the axial direction. The fourth annular steps abut against the right side of the second mold pieces 160 respectively. When the first mold 100 abuts against the second mold 200, a second corrugated forming cavity is formed between the second mold 200 and the second mold pieces 160. When the first mold 100 and the second mold 200 abut against each other, a second corrugated forming cavity is formed between the multiple second mold pieces 160 and the second mold 200. At this time, the pipe can form a second corrugation at this position. Specifically, water is injected and pressurized into the pipe, and the pipe is initially hydro-expanded and formed between the multiple spaced second mold pieces 160. Then, the first transition mold 130 moves to the left, pushing the multiple second mold pieces 160 towards the first fixed mold 191 on the left, so that the first transition mold 130, the multiple second mold pieces 160, and the first fixed mold 191 are close to each other. At this point, the formed initial wave is squeezed into the second corrugation forming cavity, and the water expansion pressure on the pipe is further increased, so that the pipe wall fits with multiple second mold pieces 160, fixing the waveform and completing the corrugation forming. Then, the first positioning shaft 110 moves to the right, and multiple third annular steps on the outside of the first positioning shaft 110 push the multiple second mold pieces 160 apart at intervals. Finally, the right sides of the multiple second mold pieces 160 abut against multiple fourth annular steps to reset at intervals. In this way, multiple corrugations can be formed on the same pipe according to different production needs.

[0032] The first mold 100 may be provided with a drive source that drives the first positioning shaft 110 to move left and right. The first mold 100 includes a first linear drive 170, a first mold base 180, and a second fixed mold 192. The first linear drive 170 is connected to the left side of the first fixed mold 191. The first fixed mold 191 and the second fixed mold 192 are respectively connected to the first mold base 180. The second fixed mold 192 is located to the right side of the first movable mold 140. The movable end of the first linear drive 170 passes through the first fixed mold 191 and is connected to the first positioning shaft 110. In practical applications, the first positioning shaft 110 and the first linear drive 170 are mainly used to provide the first positioning shaft 110 with the driving force for reciprocating movement in the left and right direction. The first linear drive 170 can be a cylinder, hydraulic cylinder or electric lead screw, etc. The second fixed mold 192 is provided with a first through groove extending in the left and right direction. The first through groove can be an independent channel provided in the second fixed mold 192, or it can be a groove structure provided on the bottom side of the second fixed mold 192, which is used to form a tube forming cavity when it is closed with the second mold 200. The first fixed mold 191 and the second fixed mold 192 are respectively fixed on the first mold base 180. The first linear drive 170 is installed on the first fixed mold 191 and provides a driving force for the first positioning shaft 110 to move in the left and right direction. The second fixed mold 192 is provided with a first through groove to provide a clearance for the peripheral drive. When it is necessary to bring the multiple first mold pieces 150 closer together to close the mold, the peripheral drive can pass through the first through groove to press against the first movable mold 140 and push the first movable mold 140 to the left, so that the first movable mold 140 presses against the first mold pieces 150 to the left, so that the multiple first mold pieces 150 fit together. When it is necessary to separate the multiple first mold pieces 150, the first linear drive 170 drives the first positioning shaft 110 to move to the right, thereby pushing the multiple first mold pieces 150 to the right in sequence at intervals.

[0033] Naturally, when performing water expansion molding on pipes, a structure for injecting water into the pipes and sealing them is required. This structure can be provided by an external device or it can be part of the water expansion molding mold itself. Specifically, this utility model also includes a water injection head 310 and a plug 320. The water injection head 310 can be inserted to the right into the first fixed mold 191 and connect the first corrugated molding cavity and the second corrugated molding cavity. The plug 320 can pass through the second fixed mold 192 to the left and press against the first movable mold 140. When the first mold 100 and the second mold 200 are closed together, the first water injection head 310 is inserted into one end of the pipe and the plug 320 is inserted into the other end of the pipe. At this time, high-pressure water can be introduced into the pipe from the first water injection head 310, and the plug 320 seals the other end of the pipe, causing the pipe to expand and form with water inside. When it is necessary to fit multiple first mold pieces 150 together, the plug 320 pushes the first movable mold 140 to the left, so that multiple first mold pieces 150 fit together.

[0034] The first positioning shaft 110 and the second positioning shaft 120 can be removed from the first mold 100 for replacement or maintenance. In this embodiment, the first positioning shaft 110 is detachably connected to the first movable mold 140, and the second positioning shaft 120 is detachably connected to the second fixed mold 192. In practical applications, screws can be driven into the right side of the first movable mold 140 and connected to the first positioning shaft 110 to lock the first movable mold 140 and the first positioning shaft 110 together. The second positioning shaft 120 is directly connected to the second fixed mold 192, thereby locking the second positioning shaft 120 and the second fixed mold 192 together. The first positioning shaft 110 can be removed from the first movable mold 140, and then multiple first mold pieces 150, first transition mold 130, multiple second mold pieces 160 and first fixed mold 191 can be removed to replace the first positioning shaft 110. The second positioning shaft 120 can be removed from the second fixed mold 192, and then multiple second mold pieces 160, first transition mold 130, multiple first mold pieces 150 and first movable mold 140 can be removed to replace the second positioning shaft 120.

[0035] To further improve the stability of the internal structure of the first mold 100, in this embodiment, a guide post 193 is connected between the first fixed mold 191 and the second fixed mold 192. The guide post 193 passes through the first movable mold 140, the plurality of first mold pieces 150, the first transition mold 130, and the plurality of second mold pieces 160. When the first movable mold 140, the plurality of first mold pieces 150, the first transition mold 130, and the plurality of second mold pieces 160 move relatively left and right, the guide post 193 can improve the stability of the first movable mold 140, the plurality of first mold pieces 150, the first transition mold 130, and the plurality of second mold pieces 160 during relative sliding. In practical applications, there are two guide posts 193, which are located on opposite sides of the two second positioning axes 120, and the center lines of the two guide posts 193 can be set to be coplanar with the center line of the first positioning axis 110 and the center lines of the two second positioning axes 120, respectively.

[0036] The corrugated structure formed by the second mold 200 can adopt the same structure as the first mold 100. In this embodiment, the structure of the second mold 200 and the structure of the first mold 100 are symmetrical. Naturally, in actual installation, since the installation positions of the second mold 200 and the first mold 100 are different, the structures used for installation and connection on the second mold 200 and the first mold 100 will be different. Similarly, the second mold 200 has a structure in which positioning shafts position multiple mold pieces at intervals, thereby forming a corrugated pattern when it is closed with the first mold 100. Specifically, the second mold 200 is provided with a third positioning shaft, a fourth positioning shaft, a second transition mold, a second movable mold, and a third mold piece. Multiple third mold pieces are spaced apart in the left-right direction. The third positioning shaft passes through the second transition mold and multiple third mold pieces in sequence and connects to the second movable mold. Multiple first annular steps 111 are provided axially on the outer side of the third positioning shaft. The outer radial direction of the multiple first annular steps 111 decreases sequentially to the right. The multiple first annular steps 111 abut against the left side of the multiple third mold pieces respectively. The fourth positioning shaft passes through the multiple third mold pieces. Multiple second annular steps 121 are provided axially on the outer side of the fourth positioning shaft. The outer radial direction of the multiple second annular steps 121 decreases sequentially to the left. The multiple second annular steps 121 abut against the right side of the multiple third mold pieces respectively. Multiple third mold pieces abut against each other on the left side using first annular steps 111 of different outer diameters on the third positioning shaft, thereby providing support and positioning on the left side of the multiple third mold pieces. Additionally, second annular steps 121 of different outer diameters on the fourth positioning shaft abut against each other on the right side of the multiple third mold pieces, thereby providing support and positioning on the right side of the multiple third mold pieces. During production, the pipe to be formed is placed between the first mold 100 and the second mold 200, which approach and abut against each other, forming a first corrugated forming cavity between the second mold 200 and the multiple third mold pieces. Water is injected and pressurized into the pipe, causing it to initially expand and form through water between the multiple spaced-apart third mold pieces. Then, the second movable mold moves to the left, driving the third positioning shaft to move to the left. The second movable mold pushes multiple third mold pieces to the second transition mold on the left, so that the second movable mold, multiple third mold pieces, and the second transition mold are close to each other. At this time, the formed initial wave is squeezed into the first corrugated forming cavity, and the water expansion pressure on the pipe is further increased, so that the pipe wall fits with multiple third mold pieces, fixing the waveform and completing the corrugation. Then, the third positioning shaft moves to the right, using multiple first annular steps 111 on the outside of the third positioning shaft to push multiple third mold pieces apart at intervals, so that the right sides of multiple third mold pieces abut against multiple second annular steps 121 to reset at intervals.

[0037] A hydroforming machine includes the aforementioned hydroforming mold. A second mold base is fixed to the machine tool of the hydroforming machine, while a first mold base 180 is fixed to a lifting drive component of the hydroforming machine. The lifting drive component can be a hydraulic cylinder, air cylinder, or hydraulic screw, etc., thereby driving the first mold 100 downward toward the second mold 200 or upward away from the second mold 200.

[0038] In this hydroforming machine, because of the aforementioned hydroforming mold, when it is necessary to produce corrugated pipes of different shapes, it is only necessary to recombine or replace the first positioning shaft 110, the second positioning shaft 120 and multiple first mold pieces 150 according to the shape of the corrugated pipe. In this way, it is not necessary to replace the entire hydroforming mold, which reduces production costs and improves the flexibility and convenience of production.

[0039] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A hydroforming die characterized by: The utility model relates to a first mold (100) is provided with first positioning shaft (110), second positioning shaft (120), first transition mold (130), first movable mold (140) and first mold piece (150) internally, a plurality of first mold piece (150) are arranged in interval along left and right directions, first positioning shaft (110) passes through first transition mold (130), a plurality of first mold piece (150) successively and is connected first movable mold (140), a plurality of first annular steps (111) are arranged in the axial direction outside first positioning shaft (110), the outer diameter of a plurality of first annular steps (111) successively reduces to the right, a plurality of first annular steps (111) are respectively abutted on the left side of a plurality of first mold piece (150), second positioning shaft (120) passes through a plurality of first mold piece (150), a plurality of second annular steps (121) are arranged in the axial direction outside second positioning shaft (120), the outer diameter of a plurality of second annular steps (121) successively reduces to the left, a plurality of second annular steps (121) are respectively abutted on the right side of a plurality of first mold piece (150). Second mold (200) can be relatively close or far away first mold (100), when first mold (100) is abutted on second mold (200), first wave forming cavity is formed between second mold (200) and a plurality of first mold piece (150). The number of second positioning shaft (120) is two, and two second positioning shaft (120) are located on the two sides of first positioning shaft (110) respectively.

2. A hydroforming die according to claim 1, wherein: The center line of first positioning shaft (110) and the center line of second positioning shaft (120) are located on the same straight line.

3. A hydroforming die according to claim 2, wherein: The left side of first transition mold (130) in first mold (100) is sequentially provided with second mold piece (160) and first fixed mold (191), a plurality of second mold piece (160) are arranged in interval along left and right directions, first positioning shaft (110) passes through first fixed mold (191) and a plurality of second mold piece (160), a plurality of third annular steps are arranged in the axial direction outside first positioning shaft (110), the outer diameter of a plurality of third annular steps successively reduces to the right, a plurality of third annular steps are respectively abutted on the left side of a plurality of second mold piece (160), second positioning shaft (120) passes through a plurality of second mold piece (160) and is connected to first fixed mold (191), a plurality of fourth annular steps are arranged in the axial direction outside second positioning shaft (120), a plurality of fourth annular steps are respectively abutted on the right side of a plurality of second mold piece (160), when first mold (100) is abutbed on second mold (200), second mold (200) and a plurality of second mold piece (160) form second wave forming cavity.

4. A hydroforming die according to claim 1, wherein: ​ 5. A hydroforming die according to claim 4, wherein: The first mold (100) comprises a first linear driving member (170), a first mold base (180) and a second fixed mold (192), the first linear driving member (170) is connected to the left side of the first fixed mold (191), the first fixed mold (191) and the second fixed mold (192) are respectively connected to the first mold base (180), the second fixed mold (192) is located at the right side of the first movable mold (140), the movable end of the first linear driving member (170) penetrates through the first fixed mold (191) and is connected to the first positioning shaft (110), and the second fixed mold (192) is provided with a first through groove extending in the left-right direction.

6. A hydroforming die according to claim 5, wherein: The first mold (100) further comprises a water injection head (310) and a plug (320), the water injection head (310) can be inserted into the first fixed mold (191) to the right and communicate with the first corrugated forming cavity and the second corrugated forming cavity, and the plug (320) can penetrate through the second fixed mold (192) to the left and press against the first movable mold (140).

7. A hydroforming die according to claim 5, wherein: The first positioning shaft (110) and the first movable mold (140) are detachably connected, and the second positioning shaft (120) and the second fixed mold (192) are detachably connected.

8. A hydroforming die according to claim 5, wherein: The first fixed mold (191) and the second fixed mold (192) are connected with a guide column (193), and the guide column (193) penetrates through the first movable mold (140), a plurality of the first mold sheets (150), the first transition mold (130) and a plurality of the second mold sheets (160).

9. A hydroforming die according to claim 1, wherein: The structure of the second mold (200) is symmetrical to the structure of the first mold (100).

10. A hydroforming machine characterized by: The water expansion forming mold comprises the water expansion forming mold according to any one of claims 1 to 9. The water expansion forming mold comprises the water expansion forming mold according to any one of claims 1 to 9.

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