CN218053740U

CN218053740U - Injection mold assembly

Info

Publication number: CN218053740U
Application number: CN202221729407.4U
Authority: CN
Inventors: 温文举; 周康康
Original assignee: Mettler Toledo Technology China Co ltd; Mettler Toledo Changzhou Measurement Technology Ltd; Mettler Toledo Changzhou Precision Instruments Ltd
Current assignee: Mettler Toledo Technology China Co ltd; Mettler Toledo Changzhou Measurement Technology Ltd; Mettler Toledo Changzhou Precision Instruments Ltd
Priority date: 2022-07-04
Filing date: 2022-07-04
Publication date: 2022-12-16
Anticipated expiration: 2032-07-04

Abstract

An injection mold assembly is provided that includes an injection mold for manufacturing a tubular plastic part including an interior cavity and a cooling tube, the injection mold including a core pin for defining a molding interior cavity. Liquid flows in the cooling pipe, and an outlet is arranged at the end part of the cooling pipe. The core needle comprises an inner hole, the inner hole is used for introducing a cooling pipe, and an annular cavity is defined by the cooling pipe and the wall surface of the inner hole; the outlet is used for draining liquid in the tube, so that the liquid enters the annular cavity to flow to take away heat of the core needle. The injection mold assembly can obtain a tubular plastic part with higher precision.

Description

Injection mold assembly

Technical Field

The utility model relates to an injection mold field, concretely relates to high accuracy plastic products mould field.

Background

The injection mold is used for molding plastic raw materials in a molten state, and after the plastic raw materials are cooled and solidified in a mold cavity, the plastic part can have a complete structure and an accurate size. In a conventional mold-drawing method, draft angles (Draft Angle) are designed on the inner wall and the outer wall of a plastic part, and the Draft angles are artificially set for better separating the plastic part from a mold, so that the part is conveniently demoulded.

For the tubular plastic part with ultrahigh precision, namely the diameter size of the tubular plastic part needs to reach ultrahigh precision within a certain axial length, at the moment, the requirement of 0-degree drawing angle is needed, so that the drawing is not applicable to the mode of setting the drawing angle, otherwise, the diameter precision of the tubular part is influenced. In addition, for the manufacture of high-precision or ultra-high precision tubular plastic parts, it is also necessary to ensure the uniformity of the inner wall dimensions to meet the requirements of ultra-high precision.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an injection mold subassembly for obtain the tubulose working of plastics of ultrahigh precision.

The injection mold assembly comprises an injection mold for manufacturing a tubular plastic part, wherein the tubular plastic part comprises an inner cavity, the injection mold comprises a core needle, the core needle is used for limiting and forming the inner cavity, the assembly further comprises a cooling pipe, liquid flows in the pipe, and an outlet is formed in the end part of the cooling pipe; the core pin comprises an inner hole, the inner hole is used for leading in the cooling pipe, and an annular cavity is defined by the cooling pipe and the wall surface of the inner hole; the outlet is used for draining liquid in the tube, so that the liquid enters the annular cavity to flow to take away heat of the core needle.

In one or more embodiments, the inner bore is cylindrical, and the cooling tube is located at the center of the inner bore such that a radial distance between an inner wall surface of the inner bore and an outer wall of the cooling tube in a circumferential direction is equal.

In one or more embodiments, the temperature of the liquid is below the freezing point of the tubular plastic member.

In one or more embodiments, the liquid is a high temperature, high pressure water at 100 to 150 ℃.

In one or more embodiments, the core pin further includes a lubricant coating attached to the outer circumferential wall surface.

Above-mentioned injection mold subassembly is through setting up the hole structure of cooling tube and core needle, makes the inside heat of core needle effectively taken away to the liquid that flows in the cooling tube and the liquid that flows into the ring chamber, reduces the fluctuation of core needle temperature in the molding cycle, ensures the uniformity of product inner wall size. In addition, the lubricating coating can also reduce strain and deformation of the inner wall of the plastic part during demoulding, and the size of the inner wall of the injection molding part is ensured.

Drawings

The above and other features, properties and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings and examples, in which:

FIG. 1 is a cross-sectional view of one embodiment of an injection mold assembly.

Description of symbol mark

1. Female die

2. Male die

3. Core needle

4. Cooling pipe

5. Injection mould

10. Tubular plastic part

11. Inner cavity

12. Outer wall

31. Inner bore

32. Peripheral wall surface

35. Ring cavity

41. An outlet

Detailed Description

The present invention will be further described with reference to the following specific embodiments and the accompanying drawings, and in the following description, more details are set forth to facilitate a full understanding of the present invention, but it is obvious that the present invention can be implemented in various other ways than those described herein, and those skilled in the art can similarly popularize and deduce according to the practical application without departing from the spirit of the present invention, and therefore, the scope of the present invention should not be limited by the contents of the specific embodiments.

It should be noted that these and other figures are given by way of example only and are not drawn to scale, and should not be construed as limiting the scope of the invention as it is actually claimed.

Plastic parts are often made using injection molds. Referring to fig. 1, an injection mold includes a male mold half 2 and a female mold half 1 for defining the outer shape of a molded plastic part. In addition, for the plastic part with an internal structure, the core needle 3 is further included, and the core needle 3 is placed inside the plastic part to form the internal structure of the plastic part. The tubular plastic member 10 shown in fig. 1 defines an inner cavity 11 of the tubular plastic member 10 by contacting the liquid plastic with the outer circumferential wall surface of the core pin 3.

After the plastic part is solidified and formed by liquid, demolding is usually realized by setting a mold drawing angle. The draft angle is a small angle artificially set on the plastic part to ensure that the part is not damaged when being demolded. However, for the ultra-high precision tubular plastic part, it is generally required to ensure that the inner diameter and the outer diameter of the tubular plastic part at each position in the axial direction are consistent. Therefore, the high-precision tubular plastic part requires a die drawing angle of 0 degree, and the mode of setting the die drawing angle is no longer suitable for demoulding the high-precision tubular plastic part. In addition, to obtain tubular plastic parts with high or ultra-high precision, it is necessary to ensure a high consistency of the diameter dimension within a certain length dimension.

In order to solve the problems, the injection mold assembly disclosed by the disclosure can obtain a high-precision or ultra-high-precision tubular plastic part, can ensure the consistency of the size of the inner wall of the tubular plastic part during manufacturing, can also reduce strain and deformation of the inner wall of the plastic part during demolding, and ensures that the size of the plastic part is not influenced.

As will be appreciated with continued reference to fig. 1, the injection mold assembly includes an injection mold 5 for making a tubular plastic part 10 and a cooling tube 4. The tubular plastic part 10 comprises an inner cavity 11 and an outer wall 12, the injection mold 5 comprises a core pin 3, a male mold 2 and a female mold 1, the core pin 3 is used for limiting the forming inner cavity 11, and the male mold 2 and the female mold 1 are used for limiting the outer wall 12 of the formed tubular plastic part 10.

The core pin 3 comprises an inner hole 31, the inner hole 31 is used for leading into the cooling pipe 4, and the cooling pipe 4 and the wall surface of the inner hole 31 define an annular cavity 35. Liquid flows in the cooling pipe 4, and an outlet 41 is provided at the end of the cooling pipe 4.

After entering the cooling pipe 4 from the inlet of the cooling pipe 4, the liquid flows toward the rear of the cooling pipe 4 as indicated by the solid arrows inside the cooling pipe 4 in fig. 1. The liquid flows to the outlet 41 at the tail end, the outlet 41 is used for guiding the liquid in the pipe, so that the liquid enters the annular cavity 35 to flow, and the flowing medium carries away the heat of the core needle 3 as indicated by a dotted arrow positioned in the annular cavity 35. The core needle 3 is mostly made of metal materials, the liquid flowing in the inner hole 31 can take away the heat inside the core needle 3, the fluctuation of the temperature of the core needle 3 in the forming period is reduced, the core needle 3 is always maintained in a fixed temperature range, and the size consistency of tubular plastic parts of products is ensured.

In some embodiments, the temperature of the liquid needs to be below the freezing point of the tubular plastic member 10 to achieve a cooling effect. After the liquid plastic is injected into the injection mold 5, the liquid plastic will gradually solidify into a solid plastic part during the injection molding process. In the process, the continuously flowing liquid can effectively take away the heat in the core pin, maintain the temperature of the core pin 3 and ensure the consistency of the size until the molten plastic particles are solidified and molded.

In addition to the above embodiments, the cooling pipe 4 is a cooling water pipe, and the liquid is preferably high-temperature and high-pressure water of 100 to 150 ℃, that is, the medium flowing in the cooling pipe 4 needs to be maintained in a liquid state. It will be appreciated by those skilled in the art that cooling may be achieved by selecting water or other medium in other conditions depending on the particular plastic material and the accuracy of manufacture.

For some injection molds, the core pin 3 has an outer diameter of about 5mm and a length of about 60mm, and the cooling water pipe may be selected to have an outer diameter of about 2 mm. In order to ensure the uniform cooling effect of the cooling tube 4 on the wall surface of the core pin 3, in some embodiments, the inner hole 31 is cylindrical, and the cooling tube 4 is located at the center of the inner hole 31, so that the radial distance between the inner wall surface of the inner hole 31 and the outer wall of the cooling tube 4 in the circumferential direction is equal, thereby ensuring that the temperature of the wall surface at each position in the circumferential direction of the core pin 3 is kept consistent, and further ensuring the size consistency of plastic parts.

After the plastics solidification, in order to make the drawing of patterns convenient, core needle 3 still includes the lubricated coating of adhering to on peripheral wall 32 to increase lubricating property, the pulling of inner wall, deformation when reducible working of plastics drawing of patterns realize not needing to set up drawing of patterns angle down the drawing of patterns, also can guarantee the inner chamber inner wall size uniformity of working of plastics.

This application uses specific language to describe embodiments of the application. Reference throughout this specification to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic described in connection with at least one embodiment of the present application is included in at least one embodiment of the present application. Therefore, it is emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, some features, structures, or characteristics of one or more embodiments of the present application may be combined as appropriate.

Although the preferred embodiments of the present invention have been disclosed, the present invention is not limited thereto, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent changes and modifications made to the above embodiments according to the technical spirit of the present invention, all without departing from the content of the technical solution of the present invention, fall within the scope of protection defined by the claims of the present invention.

Claims

1. Injection mould assembly comprising an injection mould (5) for manufacturing a tubular plastic part (10), said tubular plastic part (10) comprising an inner cavity (11), said injection mould (5) comprising a core pin (3), said core pin (3) being intended to define said inner cavity (11), characterized in that,

the assembly also comprises a cooling pipe (4) in which the liquid flows and the end of which is provided with an outlet (41);

the core needle (3) comprises an inner hole (31), the inner hole (31) is used for leading the cooling pipe (4), and an annular cavity (35) is defined by the cooling pipe (4) and the wall surface of the inner hole (31);

wherein the outlet (41) is used for draining liquid in a tube, and the liquid is enabled to flow into the annular cavity (35) so as to take away heat of the core needle (3).

2. An injection mould assembly according to claim 1, characterised in that the bore (31) is cylindrical and the cooling tube (4) is located centrally in the bore (31) such that the radial spacing of the inner wall surface of the bore (31) and the outer wall of the cooling tube (4) in the circumferential direction is equal.

3. An injection mold assembly as claimed in claim 1, wherein said liquid has a temperature below the freezing point of said tubular plastic part (10).

4. An injection mold assembly as claimed in claim 3 wherein said liquid is a high temperature, high pressure water of 100 to 150 ℃.

5. An injection mould assembly according to claim 1, wherein the core pin (3) further comprises a lubricating coating adhered to the peripheral wall surface (32).