CN111531817A

CN111531817A - Round top needle for injection mold

Info

Publication number: CN111531817A
Application number: CN202010479689.6A
Authority: CN
Inventors: 丁丹辉; 陈宏�
Original assignee: Menshen Packaging Shanghai Co Ltd
Current assignee: Menshen Packaging Shanghai Co Ltd
Priority date: 2020-05-29
Filing date: 2020-05-29
Publication date: 2020-08-14

Abstract

The invention relates to a dome needle for an injection mold, which comprises a thimble body consisting of a rod body and a base, wherein the top end of the rod body is provided with an exhaust ring groove and a plurality of exhaust through holes, the exhaust ring groove is arranged around the circumference of the rod body, the top end of the rod body is divided into a top surface block, the diameter of the top surface block is smaller than that of the rod body, the center in the thimble body is provided with a vertically arranged exhaust channel, the exhaust through holes are distributed in the rod body, the outlet end of each exhaust through hole is connected with the exhaust channel, the inlet end of each exhaust through hole is connected with the inner side surface of the exhaust ring groove, the bottom surface of the base is provided with an exhaust. Compared with the prior art, the invention realizes the circumferential whole-circle exhaust of the top surface block, and has high gas exhaust speed and good effect. Meanwhile, the device has the advantages of effectively preventing the exhaust through hole from being blocked and having wide application range.

Description

Round top needle for injection mold

Technical Field

The invention relates to the field of injection molds, in particular to a round ejector pin for an injection mold.

Background

In the injection molding and mold closing processes of the injection mold, gas in the mold needs to be discharged in time, and the gas in the mold not only comprises air in a cavity, but also comprises air in a runner and decomposed gas generated by a plastic melt. If the phenomenon of insufficient exhaust occurs on the die, the surface of the product has defects such as bonding lines, bubbles, gas marks, material shortage, unclear profile and the like; the process has the defects of difficult filling or local flash, scorch marks are generated on the surface when the process is serious, the mold filling speed is synchronously reduced, the molding period is prolonged, even the machine is stopped, and the like, so the production cost is greatly increased.

Currently, venting during production is typically performed using a dome needle having a venting structure. The round top needle originally has the function of pushing a finished product out of the die cavity, and the round top needle is provided with an exhaust structure to realize the function of exhausting the die cavity. As shown in fig. 5, the most common venting structure of the dome needle is to cut the side edge of the dome needle to a certain extent (at a) to form a venting groove, and the gas generated during injection molding can be buffered and stored in the venting groove. However, the structure has a limited gas accommodating degree, the trimming degree of an injection mold with large exhaust gas quantity is large, the assembling stability of the dome needle is affected, and the dome needle is easy to bite and wear with a mold core.

Chinese utility model with publication number CN202571239U discloses a mould exhaust thimble structure, through set up the exhaust stripe hole at the top surface of thimble, the pole body below sets up ventilative through-hole to connect exhaust stripe hole and ventilative through-hole through the exhaust cavity and realize exhausting. However, the structure easily causes the waste material of the injection molding material to directly block the exhaust stripe holes, and the service life is influenced. And the ventilation through hole arranged on the rod body needs to be matched with a specific mold for use, so that the applicability is poor.

Disclosure of Invention

The present invention is directed to overcoming the above-mentioned drawbacks of the prior art and providing a dome needle for an injection mold, which is used to optimize the venting of the injection mold, improve the quality of the mold formation, and improve the service life of the dome needle itself.

The purpose of the invention can be realized by the following technical scheme:

the utility model provides a calotte needle for injection mold, includes the thimble body of compriseing pole body and base, and pole body top is equipped with exhaust ring groove and a plurality of exhaust through-hole, the circumference setting of exhaust ring groove ring around the pole body, cut apart the top of pole body and form a top piece, the diameter of this top piece is less than the diameter of pole body, the inside central authorities of thimble body exhaust passage that has vertical setting, a plurality of exhaust through-holes distribute in pole body, exhaust passage is connected to the exit end of every exhaust through-hole, the medial surface of inlet end connection exhaust ring groove, base bottom surface be equipped with the air discharge duct, the bottom through connection air discharge duct of exhaust passage.

Further, the plurality of exhaust through holes are uniformly distributed in the exhaust ring groove along the circumferential direction of the rod body.

Further, the stem body is internally provided with four exhaust through holes which are distributed in a cross shape.

Further, the plurality of air exhaust through holes are horizontally distributed in the shaft.

Further, the exhaust through holes are obliquely arranged, and the outlet ends of the exhaust through holes are higher than the inlet ends of the exhaust through holes.

Furthermore, the inclined included angle formed by the exhaust through hole and the horizontal plane is 5-40 degrees.

Furthermore, the exhaust groove penetrates through the bottom surface of the base.

Furthermore, the thimble body adopts high-speed tool steel material.

Further, the distance between the side surface of the top surface block and the side surface of the rod body is 0.01-0.03 mm.

Further, the exhaust passage is cylindrical or cubic.

Compared with the prior art, the invention has the following advantages:

1. according to the invention, through the design of the top surface block and the exhaust ring groove, the whole circle of circumferential exhaust of the top surface block is realized, the gas exhaust speed is high, and the effect is good; the exhaust ring groove plays a role in blocking and protecting the exhaust through hole; the exhaust groove is arranged on the bottom surface of the base, and the open structure of the base is ingeniously utilized, so that the invention can be adapted to various types of moulds.

2. The exhaust through holes are uniformly distributed along the circumferential direction of the rod body, so that the stress of the dome needle is uniform during exhaust, the abrasion degree is uniform, and the service life is obviously prolonged.

3. The plurality of exhaust through holes are obliquely arranged, so that waste materials are further prevented from entering the exhaust channel to cause blockage, and the use stability is improved.

Drawings

Fig. 1 is a schematic structural diagram of the first embodiment.

Fig. 2 is a schematic internal structure diagram of the first embodiment.

FIG. 3 is a schematic cross-sectional view of the first embodiment.

Fig. 4 is a schematic cross-sectional view of the second embodiment.

Fig. 5 is a schematic top view and a schematic cross-sectional view of a conventional thimble.

Reference numerals: 1. the air exhaust device comprises a rod body, 11, an air exhaust ring groove, 12, an air exhaust through hole, 13, a top surface block, 14, an air exhaust channel, 2, a base, 21 and an air exhaust groove.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.

As shown in fig. 1 to 3, the present embodiment provides a round thimble for an injection mold, which includes a thimble body composed of a shank 1 and a base 2. The top end of the rod body 1 is provided with an exhaust ring groove 11 and a plurality of exhaust through holes 12. The exhaust ring groove 11 is arranged around the circumference of the shaft 1, and divides the top end of the shaft 1 into a top surface block 13. The top block 13 has a diameter smaller than that of the shaft 1. Specifically, the distance between the side surface of the top block 13 and the side surface of the shaft 1 is 0.01 to 0.03mm, and in this embodiment, 0.02mm is used. The center of the interior of the thimble body is provided with a vertically arranged exhaust channel 14, and a plurality of exhaust through holes 12 are distributed in the rod body 1. The outlet end of each vent through hole 12 is connected to a vent passage 14, and the inlet end is connected to the inner side surface of the vent ring groove 11. The bottom surface of the base 2 is provided with an exhaust groove 21, the bottom end of the exhaust channel 14 is communicated with the exhaust groove 21, and the exhaust groove 21 penetrates through the bottom surface of the base 2.

In this embodiment, four exhaust through holes 12 are specifically adopted and uniformly distributed in the shaft 1 in a cross shape. And the exhaust through holes 12 are horizontally distributed. The exhaust through holes 12 are uniformly distributed along the circumferential direction of the rod body 1, so that the round top needle is uniformly stressed during exhaust, the abrasion degree is uniform, and the service life is obviously prolonged. The exhaust passage 14 may be cylindrical, cubic, or the like. The thimble body is made of SKH51 high-speed tool steel (Chinese GB: W6Mo5Cr4V 2).

When the injection molding machine is used, gas generated by injection molding is introduced into the exhaust ring groove 11 through a gap formed by the height difference between the side surface of the top surface block 13 and the side surface of the rod body 1, the gas in the exhaust ring groove 11 enters the exhaust groove 21 at the bottom through the exhaust through hole 12 and the exhaust channel 14, and finally is introduced to the outside of a mold, so that the injection molding action is rapidly completed. In the embodiment, through the design of the top surface block 13 and the exhaust ring groove 11, the whole circumferential circle of exhaust of the top surface block 13 is realized, the gas exhaust speed is high, and the effect is good; the exhaust ring groove 11 plays a role in blocking and protecting the exhaust through hole 12; the exhaust groove 21 is formed in the bottom surface of the base 2, and the open structure of the base 2 is ingeniously utilized, so that the round ejector pin can be matched with various types of molds.

In another embodiment, as shown in fig. 4, the outlet ends of the exhaust through holes 12 are higher than the inlet ends so that the exhaust through holes 12 are arranged obliquely. In general, the inclined angle formed by the exhaust through hole 12 and the horizontal plane is 5 to 40 degrees, and 20 degrees is adopted in the embodiment. The inclined exhaust through holes 12 can further prevent waste materials from entering the exhaust channel 14 to cause blockage, and improve the use stability.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.

Claims

1. A round top needle for an injection mold comprises a thimble body consisting of a rod body (1) and a base (2), it is characterized in that the top end of the rod body (1) is provided with an exhaust ring groove (11) and a plurality of exhaust through holes (12), the exhaust ring groove (11) is arranged around the circumference of the rod body (1) to divide the top end of the rod body (1) into a top surface block (13), the diameter of the top surface block (13) is smaller than that of the rod body (1), the center inside the thimble body is provided with a vertically arranged exhaust channel (14), the plurality of exhaust through holes (12) are distributed in the shaft body (1), the outlet end of each exhaust through hole (12) is connected with an exhaust channel (14), the inlet end is connected with the inner side surface of the exhaust ring groove (11), the bottom surface of the base (2) is provided with an exhaust groove (21), and the bottom end of the exhaust channel (14) is communicated with the exhaust groove (21).

2. The ejector pin for an injection mold according to claim 1, wherein the plurality of exhaust through holes (12) are uniformly distributed in the exhaust ring groove (11) along the circumferential direction of the pin body (1).

3. A thimble for an injection mould according to claim 2, characterised in that the shank (1) has four exhaust openings (12) therein and is arranged in a cruciform pattern.

4. A thimble for an injection mould according to claim 1, wherein said plurality of vent through holes (12) are horizontally distributed in the shank (1).

5. Ejector pin for injection molds according to claim 1, characterized in that said exhaust through holes (12) are inclined with their outlet ends higher than their inlet ends.

6. The ejector pin for an injection mold according to claim 5, wherein the exhaust through hole (12) forms an inclined angle of 5 to 40 degrees with a horizontal plane.

7. A thimble for an injection mould according to claim 1, wherein said vent groove (21) extends through the bottom surface of the base (2).

8. The round thimble for the injection mold according to claim 1, wherein the thimble body is made of high speed tool steel.

9. The ejector pin for an injection mold according to claim 1, wherein the distance from the side surface of the top surface block (13) to the side surface of the pin body (1) is 0.01 to 0.03 mm.

10. A thimble for an injection mould according to claim 1, wherein said vent passage (14) is cylindrical or cubical.