Pipe extrusion variable-wall die

Abstract

The utility model discloses a pipe extrusion wall-changing die which comprises a core rod and a mouth die, a forming cavity is formed between the core rod and the mouth die, the mouth die comprises a mouth die base and a mouth die wall-changing piece, the core rod comprises a core rod base and a core rod wall-changing piece, during installation, the outer surface of the core rod is sleeved with the mouth die base in a penetrating mode, and the mouth die base is sleeved with the mouth die wall-changing piece in a penetrating mode. The die holder is not in contact with the core rod; and the mouth mold wall changing piece is mounted on the right side of the mouth mold base. According to the method disclosed by the invention, the shutdown mold changing and startup time is about 0.5-1h, and the startup time is shortened by 3-11h, so that the mold changing rate is greatly improved, and the mold changing difficulty is reduced; therefore, the die change waste rate is also reduced from 0.6 to 0.8 percent to 0.1 to 0.2 percent; 100-250 kilowatt-hour electricity is saved by single-time starting-up die change of the specifications of dn200 and below, and more than 1000 kilowatt-hour electricity is saved by single-time starting-up die change of the specifications of dn250 and above; through the arrangement of the variable wall piece, the number of molds is greatly reduced.

Description

Technical Field

[0001] The invention relates to the field of pipe production lines, and in particular to a pipe extrusion variable wall die. Background Art

[0002] At present, in order to meet market demand, polyvinyl chloride pipes and polyolefin pipes have a wide variety of specifications, and the same specification often has multiple wall thickness series. When the production line needs to change the production of pipes with different wall thicknesses or different specifications, it needs to stop and cool down. When the temperature is relatively low, the employees manually disassemble the core rod and die, clean the head material in the mold, and then install the core rod and die of the required size, and then heat up and start production. This process is not only labor-intensive and takes a long time to change the mold (about 5-8 hours, more than 12 hours for large specifications), but also wastes labor, and wastes a lot of energy in the cooling and heating process, and wastes a lot of head material; at the same time, a traditional specification series requires a set of core rods and dies. The more specifications there are, the more molds are needed, resulting in high mold investment and the molds occupying a large space.

[0003] The variable diameter molds on the market are fixed die sizes. Different series of products are produced by replacing core rods of different sizes. However, this method still requires processes such as cooling down, demolding, cleaning, and heating up to start the machine. Summary of the invention

[0004] The purpose of the invention is to provide a pipe extrusion variable wall die.

[0005] The technical solution for achieving the purpose of the present invention is: a pipe extrusion variable wall die, including a core rod and a die, a molding cavity is between the core rod and the die, the die includes a die seat and a die variable wall piece, the core rod includes a core rod base and a core rod variable wall piece, when installed, the die seat is inserted into the outer surface of the core rod, and there is no contact between the die seat and the core rod; the die variable wall piece is installed on the right side of the die seat.

[0006] Preferably, the die base is provided with a boss Ⅰ, and the bottom of the die wall change piece is provided with a groove Ⅰ, and the boss Ⅰ and the groove Ⅰ cooperate with each other to ensure that the center of the die base and the die wall change piece are in a straight line.

[0007] Preferably, the inner wall of the die variable wall part is provided with a variable wall section I and a straight section I. The variable wall section is arc-shaped, and the arc length of the variable wall section is 0.1-50mm. The inner diameter of the junction of the variable wall section I and the groove I is the same as the inner diameter of the die seat boss to ensure that there is no material jamming; the length of the variable wall section I is 0.1-10mm, and the length of the straight section I is 30-300mm.

[0008] Preferably, the core rod base is provided with a groove II, and the core rod wall changing piece is provided with a boss II, and the boss II cooperates with the groove II to ensure that the center degrees of the core rod base and the core rod wall changing piece are in a straight line.

[0009] Preferably, the outer wall of the core rod wall variable component is provided with a wall variable section II and a straight section II, the wall variable section II is in the shape of an oblique line, and the angle between the wall variable section II and the center line of the core rod wall variable component is 0.05°-45°.

[0010] Preferably, the oblique length of the variable wall section II is 0.1-50 mm, the length of the variable wall section II is 0.1-10 mm, and the length of the straight section II is 30-300 mm.

[0011] By adopting the above technical solution, the present invention has the following beneficial effects: (1) The present invention has an ingenious structure, and the shutdown time for mold change is about 0.5-1h, and the large-caliber only takes 1-1.5h, and the startup time is shortened by 3-11h, which greatly improves the mold change rate and reduces the difficulty of mold change;

[0012] (2) Since the heating and cooling time is greatly shortened, the mold change scrap rate is reduced from 0.6-0.8% to 0.1-0.2%; a single start-up mold change of DN200 and below specifications saves 100-250 degrees of electricity, and a single start-up mold change of DN250 and above specifications saves more than 1000 degrees of electricity;

[0013] (3) The present invention greatly reduces the number of molds by setting variable wall parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments and in conjunction with the accompanying drawings, wherein

[0015] Figure 1 A cross-sectional view of a pipe extrusion variable wall die of the present invention from a certain perspective

[0016] Figure 2 It is a cross-sectional view of the die of the present invention;

[0017] Figure 3 for Figure 2 Structural cross-sectional view of the middle die base and the die wall changing part;

[0018] Figure 4 is a cross-sectional view of the core rod in the present invention;

[0019] Figure 5 for Figure 4 Structural cross-sectional view of the core rod base and the core rod wall changer. DETAILED DESCRIPTION Embodiment 1

[0020] See Figures 1 to 5The pipe extrusion variable wall die of this embodiment includes a core rod 1 and a die 2, a molding cavity is formed between the core rod and the die, the die includes a die seat 3 and a die variable wall component 4, the core rod includes a core rod base 5 and a core rod variable wall component 6, when installed, the die seat 3 is inserted into the outer surface of the core rod 1, and there is no contact between the die seat 3 and the core rod 1; the die variable wall component 4 is installed on the right side of the die seat.

[0021] The die base is provided with a boss Ⅰ15, and the bottom of the die wall changing piece is provided with a groove Ⅰ16. The boss Ⅰ and the groove Ⅰ cooperate with each other to ensure that the center of the die base and the die wall changing piece are in a straight line.

[0022] The inner wall of the die variable wall part is provided with a variable wall section Ⅰ7 and a straight section Ⅰ8. The variable wall section is arc-shaped, and the arc length of the variable wall section is 0.1-50mm. The inner diameter of the intersection of the variable wall section Ⅰ and the groove Ⅰ is the same as the inner diameter of the die seat boss to ensure that there is no material jamming; the length of the variable wall section Ⅰ is 0.1-10mm, and the length of the straight section Ⅰ is 30-300mm.

[0023] The core rod base 5 is provided with a groove II 9, and the core rod wall changing piece 6 is provided with a boss II 10. The boss II cooperates with the groove II to ensure that the center of the core rod base and the core rod wall changing piece are in a straight line.

[0024] The outer wall of the core rod wall changing member 6 is provided with a wall changing section II 11 and a straight section II 12. The wall changing section II is in the shape of an oblique line, and the angle between the wall changing section II and the center line of the core rod wall changing member is 0.05°-45°.

[0025] The oblique length of the variable wall section II is 0.1-50 mm, the length of the variable wall section II is 0.1-10 mm, and the length of the straight section II is 30-300 mm.

[0026] In specific implementation, when replacement is required, P1: When replacing products of the same specification but different wall thickness, stop the machine, dismantle the originally installed die wall changing parts and replace them with the die wall changing parts of the required size;

[0027] P2: If the wall thickness span is large or the specifications are changed, the core rod wall changing parts and the die wall changing parts should be replaced.

[0028] When installation is required:

[0029] Install the mandrel, first install the mandrel base on the extruder head, and then install the mandrel wall changing piece on the mandrel base. At this time, the boss II 10 of the mandrel wall changing piece is inserted into the groove II 9 of the mandrel base 5. The boss II and the groove II cooperate with each other to ensure that the center of the mandrel base and the mandrel wall changing piece are in a straight line;

[0030] The die base is installed by inserting a sleeve outside the installed mandrel, and then the die wall changing piece is installed on the die base. At this time, the boss Ⅰ15 of the die base is inserted into the groove Ⅰ16 at the bottom of the die wall changing piece. At the same time, the inner diameter of the intersection of the wall changing section Ⅰ7 of the inner wall of the die wall changing piece near one end of the die base and the groove Ⅰ is equal to the inner diameter of the boss of the die base;

[0031] A forming cavity is formed between the core rod and the die. The core rod and the die are coaxially arranged and matched with the bottom die.

[0032] The utility model provides a pipe extrusion variable wall die, which takes about 0.5-1h to shut down and change the die, and only 1-1.5h for large diameter, and the start-up time is shortened by 3-11h, which greatly improves the die change rate and reduces the difficulty of die change, and reduces the die change waste rate from 0.6-0.8% to 0.1-0.2%; a single start-up and die change of DN200 and below specifications saves 100-250 degrees of electricity, and a single start-up and die change of DN250 and above specifications saves more than 1000 degrees of electricity; the variable wall parts greatly reduce the number of molds.

[0033] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A variable wall die for pipe extrusion, characterized in that: The invention comprises a core rod (1) and a die (2), wherein a molding cavity is formed between the core rod and the die, wherein the die comprises a die seat (3) and a die wall-changing component (4), and wherein the core rod comprises a core rod base (5) and a core rod wall-changing component (6). When installed, the die seat (3) is inserted into the outer surface of the core rod (1), and there is no contact between the die seat (3) and the core rod (1); and the die wall-changing component (4) is installed on the right side of the die seat.

2. The pipe extrusion variable wall die according to claim 1, characterized in that: The die base is provided with a boss Ⅰ (15), and the bottom of the die wall changing piece is provided with a groove Ⅰ (16), and the boss Ⅰ and the groove Ⅰ cooperate with each other to ensure that the center degrees of the die base and the die wall changing piece are in a straight line.

3. The variable wall die for pipe extrusion according to claim 2, characterized in that: The inner wall of the die wall-changing member is provided with a wall-changing section I (7) and a straight section I (8); the wall-changing section I is arc-shaped, and the arc length of the wall-changing section is 0.1-50 mm; the inner diameter of the junction between the wall-changing section I and the groove I is the same as the inner diameter of the die seat boss; the length of the wall-changing section I is 0.1-10 mm, and the length of the straight section I is 30-300 mm.

4. The variable wall die for pipe extrusion according to claim 1, characterized in that: The core rod base (5) is provided with a groove II (9), and the core rod wall changing piece (6) is provided with a boss II (10), wherein the boss II cooperates with the groove II to ensure that the center degrees of the core rod base and the core rod wall changing piece are in a straight line.

5. The variable wall die for pipe extrusion according to claim 4, characterized in that: The outer wall of the core rod wall changing member (6) is provided with a wall changing section II (11) and a straight section II (12); the wall changing section II is in the shape of an oblique line; and the angle between the wall changing section II and the center line of the core rod wall changing member is 0.05°-45°.

6. The variable wall die for pipe extrusion according to claim 5, characterized in that: The oblique length of the variable wall section II is 0.1-50 mm, the length of the variable wall section II is 0.1-10 mm, and the length of the straight section II is 30-300 mm.

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