Plastic pipe extrusion die

Abstract

The utility model discloses an extrusion die for a plastic pipe, comprising a casing, a filter plate, an inner bracket, a flow guide sleeve, an inner mold core, and an outer mold core. The casing is a hollow structure, one end of the filter plate is matched with one end of the casing and fixed to the casing, a plurality of first through holes are arranged on the filter plate, the inner bracket is located in the casing, a plurality of second through holes are arranged on the inner bracket, the inner bracket is sleeved on the inner mold core and fixed to the inner mold core, the flow guide sleeve is located in the casing, the flow guide sleeve is located between the outer mold core and the inner bracket, the inner bracket, the flow guide sleeve and the outer mold core are fixed to the casing as a whole, the flow guide sleeve and the outer mold core surround the inner mold core, and an annular cavity for molding the plastic pipe is formed between the inner mold core, the flow guide sleeve and the outer mold core. The utility model has the advantage of reducing production costs.

Description

Technical Field

[0001] The utility model relates to the technical field of plastic pipes, in particular to an extrusion die for plastic pipes. Background Art

[0002] Plastic pipes are widely used in construction, industrial applications and other fields due to their advantages in energy saving, land saving, water saving and material saving. According to statistics, the total output of plastic pipes in my country reached 18 million tons in 2021. With the diversification of plastic pipe styles and processing methods, the molding process of plastic pipes has also shown a diversified trend. Common plastic pipe molding methods include injection molding, blow molding, extrusion molding, etc. In different molding processes, the use of molds plays a key role in the molding and production of product quality, and extrusion molding, as a continuous molding method, has been widely used in the manufacture and production of plastic pipes.

[0003] With the development of industry, extrusion dies have been widely used in the production and manufacturing of plastic pipes. Plastic pipe extrusion dies are usually designed based on the designer's experience. In order to ensure that the extrusion die has sufficient strength and rigidity, the size of the extrusion die is often increased to a certain extent. This unreasonable design method will cause the extrusion die to be too heavy and cause waste of raw materials. Utility Model Content

[0004] The utility model provides an extrusion die for a plastic pipe, which has the advantage of reducing production costs.

[0005] The technical solutions to the above problems are as follows:

[0006] The extrusion die of the plastic pipe comprises a casing, a filter plate, an inner bracket, a guide sleeve, an inner mold core and an outer mold core. The casing is a hollow structure. One end of the filter plate is matched with one end of the casing and fixed to the casing. A plurality of first through holes are arranged on the filter plate. The inner bracket is located in the casing. A plurality of second through holes are arranged on the inner bracket. The inner bracket is sleeved on the inner mold core and fixed to the inner mold core. The guide sleeve is located in the casing. The guide sleeve is located between the outer mold core and the inner bracket. The inner bracket, the guide sleeve and the outer mold core are fixed to the casing as a whole. The guide sleeve and the outer mold core surround the inner mold core. An annular cavity for molding the plastic pipe is formed between the inner mold core, the guide sleeve and the outer mold core.

[0007] Furthermore, the inner bracket includes an inner support sleeve, an outer support sleeve, and multiple support rods, each support rod is located between the inner support sleeve and the outer support sleeve, one end of the support rod is fixed to the inner support sleeve, and the other end of the support rod is fixed to the outer support sleeve, and the second through hole is formed between the inner support sleeve, the outer support sleeve and two adjacent support rods.

[0008] Furthermore, the inner mold core includes an inner mold core body and a diverter cone. The diverter cone is located between the inner mold core body and the filter plate. The diverter cone is fixed to the inner mold core body. A portion of the inner bracket is clamped between the inner mold core body and the diverter cone.

[0009] Furthermore, an assembly hole is provided on the inner mold core body, and the diverter cone includes a cone and a connecting column. The cone is fixed to one end of the connecting column, and the outer diameter of one end of the cone is larger than the outer diameter of the connecting column. After the connecting column is connected to the assembly hole, an annular groove is formed between the inner mold core body and the diverter cone, and a part of the inner bracket cooperates with the annular groove.

[0010] Furthermore, it also includes a clamping plate, a first limiting step is provided on the inner wall surface of the casing, a second limiting step is provided on the outer peripheral surface of the outer mold core, the clamping plate is sleeved on the outer mold core and cooperates with the second limiting step, after the clamping plate is fixed to the other end of the casing, the outer mold core, the guide sleeve and the inner bracket are clamped between the first limiting step and the clamping plate.

[0011] The use process of the utility model is:

[0012] The molten plastic enters the housing through the first through hole on the filter plate. Under the flow-guiding effect of the cone, the molten plastic flows through the second through hole into the conical cavity between the flow-guiding sleeve and the inner mold core body, and then flows into the annular cavity, exerting a cooling effect on the outer mold core. For example, an annular cooling jacket (not shown in the figure) is provided on the outer mold core, and a cooling channel is formed between the cooling jacket and the outer mold core. Through the effect of heat exchange, the molten plastic is cooled and formed into a pipe in the annular cavity, and a pulling force is applied to the formed pipe, thereby obtaining the pipe. The mold of the utility model is composed of several simple parts, and the structure of the extrusion mold is optimized, so that the mass of the extrusion mold is lightened, the waste of raw materials is avoided, and the production cost is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a cross-sectional view of the extrusion die of the plastic pipe of the utility model in the first direction.

[0014] Figure 2 It is a cross-sectional view of the extrusion die of the plastic pipe of the utility model in the second direction.

[0015] Figure 3 This is the assembly drawing of the inner bracket and the inner mold core.

[0016] Figure 4 This is the structural diagram of the inner mold core.

[0017] Markings in the accompanying drawings:

[0018] Casing 21, first limiting step 21a, radial hole 21b, filter plate 22, first through hole 22a, inner bracket 23, second through hole 23a, support sleeve 23b, outer support sleeve 23c, multiple support rods 23d, guide sleeve 24, inner mold core 25, inner mold core body 25a, assembly hole 25b, cone 25c, connecting column 25d, annular groove 25e, outer mold core 26, second limiting step 26a, annular cavity 27, clamping plate 28, screw 29. DETAILED DESCRIPTION

[0019] The utility model is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0020] like Figures 1 to 4 As shown, the extrusion die of the plastic pipe of the utility model includes a casing 21, a filter plate 22, an inner bracket 23, a guide sleeve 24, an inner mold core 25, and an outer mold core 26. The casing 21 is a hollow structure. One end of the filter plate 22 is matched with one end of the casing 21 and fixed to the casing 21. A plurality of first through holes 22a are provided on the filter plate 22, and the molten plastic can be filtered through the filter plate 22.

[0021] The inner bracket 23 is located in the casing 21 and is provided with a plurality of second through holes 23a. The inner bracket 23 is sleeved on the inner mold core 25 and fixed to the inner mold core 25. With this structure, the inner mold core 25 can be suspended in the casing 21 and the molten plastic can flow through the second through holes 23a.

[0022] In this embodiment, the inner support 23 includes an inner support sleeve 23b, an outer support sleeve 23c, and a plurality of support rods 23d. The inner support sleeve 23b is annular, and the outer support sleeve 23c is annular. Each support rod 23d is located between the inner support sleeve 23b and the outer support sleeve 23c. One end of the support rod 23d is fixed to the inner support sleeve 23b, and the other end of the support rod 23d is fixed to the outer support sleeve 23c. The support rod 23d is a quadrangular prism structure. The second through hole 23a is formed between the inner support sleeve 23b, the outer support sleeve 23c, and two adjacent support rods 23d. The inner support sleeve 23b is fixed to the inner mold core 25, and the outer support sleeve 23c is fixed to the housing 21, so that the inner mold core 25 is suspended in the housing 21 through the inner support 23.

[0023] The guide sleeve 24 is located in the casing 21, and the guide sleeve 24 is located between the outer mold core 26 and the inner bracket 23. The inner bracket 23, the guide sleeve 24 and the outer mold core 26 are fixed as a whole with the casing 21. The inner diameter of one end of the inner hole of the guide sleeve 24 is larger than the inner diameter of the other end of the inner hole. Therefore, the inner diameter of the guide sleeve 24 is a tapered hole. One end of the guide sleeve 24 cooperates with the inner bracket 23, and the other end of the guide sleeve 24 cooperates with the outer mold core 26.

[0024] The inner mold core 25 includes an inner mold core body 25a and a diverter cone. The diverter cone is located between the inner mold core body 25a and the filter plate 22. The diverter cone is fixed to the inner mold core body 25a. A portion of the inner bracket 23 is clamped between the inner mold core body 25a and the diverter cone.

[0025] The present embodiment further includes a clamping plate 28, a first limiting step 21a is provided on the inner wall surface of the casing 21, a second limiting step 26a is provided on the outer peripheral surface of the outer mold core 26, the clamping plate 28 is sleeved on the outer mold 26 and cooperates with the second limiting step 26a, after the clamping plate 28 is fixed to the other end of the casing 21, the outer mold core 26, the guide sleeve 24 and the inner bracket 23 are clamped between the first limiting step 21a and the clamping plate 28, the clamping plate 28 and the first limiting step 21a generate an axial tightening force on the outer mold core 26, the guide sleeve 24 and the inner bracket 23.

[0026] The clamping plate 28 is provided with an axial mounting hole, and the outer mold core 26 passes through the axial mounting hole on the clamping plate 28. Since the clamping plate 28 and the housing 21 are fixed by screws 29, the clamping plate 28 forms a support for the outer mold core 26. In addition, a preferred method is to arrange a plurality of radial holes 21b at intervals on the circumferential surface of the housing 21. The radial holes 21b are threaded holes, and each radial hole 21b is threadedly connected with a bolt (not shown in the figure). After the bolt is extended into the interior of the housing 21, the end of the bolt forms abutment with the circumferential surface of the outer mold core 26, so that the outer mold core 26 and the housing 21 are fixed as a whole along the radial direction.

[0027] A more preferred way is to set an axial countersunk hole on the second limiting step 26a and a threaded mounting hole on the axial end face of the guide sleeve 24, and use screws to pass through the countersunk hole on the second limiting step 26a and threadedly connect with the threaded mounting hole on the guide sleeve 24 to fasten the outer mold core 26 to the guide sleeve 24. In this way, when assembling the guide sleeve 24, there is no need to set a support structure in the radial direction of the guide sleeve 24.

[0028] The inner mold core body 25a is provided with an assembly hole 25b, and the assembly hole 25b is provided with an internal thread. The diverter cone includes a cone 25c and a connecting column 25d, and the cone 25c is fixed to one end of the connecting column 25d. The outer diameter of one end of the cone 25c is greater than the outer diameter of the connecting column 25d. After the connecting column 25d is connected to the assembly hole 25b, an annular groove 25e is formed between the inner mold core body 25a and the diverter cone, and a part of the inner bracket 23 is matched with the annular groove 25e.

[0029] An external thread is provided on the connecting column 25d, and the connecting column 25d and the assembly hole 25b are fixed into one by threaded cooperation. The thickness of the inner support sleeve 23b is equal to the depth of the annular groove 25e. Therefore, when the inner support sleeve 23b is matched with the annular groove 25e, the outer diameter of the inner support sleeve 23b is equal to the outer diameter of the inner mold core body 25a. This can avoid the formation of flow obstruction to the molten plastic due to the different outer diameters of the inner support sleeve 23b and the inner mold core body 25a.

[0030] The guide sleeve 24 and the outer mold core 26 surround the inner mold core 25, and an annular cavity 27 for molding the plastic pipe is formed between the inner mold core 25 and the outer mold core 26. Since the outer mold core 26 is supported by the clamping plate 28 and the bolts installed in the radial hole 21b, the outer mold core 26 surrounds the inner mold core 25, thereby forming an annular cavity 27 for molding the plastic pipe between the inner mold core 25 and the outer mold core 26, and the distance between the inner mold core 25 and the outer mold core 26 is the wall thickness of the extruded pipe.

[0031] The use process of the utility model is:

[0032] The molten plastic enters the casing 21 through the first through hole 22a on the filter plate 22. Under the guiding effect of the cone 25c, the molten plastic flows through the second through hole 23a to the conical cavity between the guide sleeve 24 and the inner mold core body 25a, and then flows into the annular cavity 27, exerting a cooling effect on the outer mold core 26. For example, an annular cooling jacket (not shown in the figure) is provided on the outer mold core 26 to form a cooling channel between the cooling jacket and the outer mold core 26. Through the effect of heat exchange, the molten plastic is cooled in the annular cavity 27 and formed into a pipe, and a tensile force is applied to the formed pipe to obtain the pipe.

[0033] Finally, it should be noted that the above embodiments are merely preferred embodiments of the present invention and are used to illustrate the technical solution of the present invention, rather than limiting it, let alone limiting the protection scope of the present invention. Although the utility model has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features therein may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solution from the protection scope of the claims.

Claims

1. Plastic pipe extrusion die, characterized in that: The invention comprises a casing (21), a filter plate (22), an inner bracket (23), a flow guide sleeve (24), an inner mold core (25), and an outer mold core (26); the casing (21) is a hollow structure; one end of the filter plate (22) is matched with one end of the casing (21) and fixed to the casing (21); a plurality of first through holes (22a) are provided on the filter plate (22); the inner bracket (23) is located in the casing (21); a plurality of second through holes (23a) are provided on the inner bracket (23); the inner bracket (23) is sleeved on the inner mold core (25); and the outer mold core (26) is sleeved on the inner mold core (26). 5) and is fixed to the inner mold core (25), the guide sleeve (24) is located in the casing (21), the guide sleeve (24) is located between the outer mold core (26) and the inner bracket (23), the inner bracket (23), the guide sleeve (24) and the outer mold core (26) are fixed to the casing (21) as a whole, the guide sleeve (24) and the outer mold core (26) surround the inner mold core (25), and an annular cavity (27) for molding a plastic pipe is formed between the inner mold core (25), the guide sleeve (24) and the outer mold core (26).

2. The extrusion die for plastic pipe according to claim 1, characterized in that: The inner bracket (23) comprises an inner support sleeve (23b), an outer support sleeve (23c), and a plurality of support rods (23d), each support rod (23d) is located between the inner support sleeve (23b) and the outer support sleeve (23c), one end of the support rod (23d) is fixed to the inner support sleeve (23b), and the other end of the support rod (23d) is fixed to the outer support sleeve (23c), and the second through hole (23a) is formed between the inner support sleeve (23b), the outer support sleeve (23c), and two adjacent support rods (23d).

3. The extrusion die for plastic pipe according to claim 1, characterized in that: The inner mold core (25) comprises an inner mold core body (25a) and a diverter cone. The diverter cone is located between the inner mold core body (25a) and the filter plate (22). The diverter cone is fixed to the inner mold core body (25a). A portion of the inner bracket (23) is clamped between the inner mold core body (25a) and the diverter cone.

4. The extrusion die for plastic pipe according to claim 3, characterized in that: The inner mold core body (25a) is provided with an assembly hole (25b), and the diverter cone comprises a cone (25c) and a connecting column (25d). The cone (25c) is fixed to one end of the connecting column (25d), and the outer diameter of one end of the cone (25c) is greater than the outer diameter of the connecting column (25d). After the connecting column (25d) is connected to the assembly hole (25b), an annular groove (25e) is formed between the inner mold core body (25a) and the diverter cone, and a part of the inner bracket (23) cooperates with the annular groove (25e).

5. The extrusion die for plastic pipe according to claim 1, characterized in that: It also includes a clamping plate (28), a first limiting step (21a) is provided on the inner wall surface of the casing (21), a second limiting step (26a) is provided on the outer peripheral surface of the outer mold core (26), the clamping plate (28) is sleeved on the outer mold core (26) and cooperates with the second limiting step (26a), and after the clamping plate (28) is fixed to the other end of the casing (21), the outer mold core (26), the guide sleeve (24) and the inner bracket (23) are clamped between the first limiting step (21a) and the clamping plate (28).

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