CN112959616A

CN112959616A - Multi-part micro-plastic part injection mold

Info

Publication number: CN112959616A
Application number: CN202110327731.7A
Authority: CN
Inventors: 侍中楼; 张剑雯
Original assignee: Jianghan University
Current assignee: Jianghan University
Priority date: 2021-03-26
Filing date: 2021-03-26
Publication date: 2021-06-15

Abstract

The invention discloses an injection mold for a multi-part micro plastic part, which comprises an upper mold core, a lower mold core and a demolding mechanism, wherein the upper mold core is provided with a first cavity and a second cavity; a main runner, a plurality of sub-runners and a plurality of cavities are formed between the lower die core and the upper die core, the center of the main runner is positioned under the pouring gate, each sub-runner is vertically intersected with the main runner and uniformly arranged along the length direction of the main runner, and each cavity is uniformly distributed on two sides of each sub-runner and is communicated with the sub-runners; the demoulding mechanism comprises a material pulling rod and a plurality of push rods. The technical scheme provided by the invention has the beneficial effects that: the main runner is arranged between the lower die core and the upper die core, the plurality of sub-runners which are vertically crossed with the main runner are uniformly arranged along the main runner, and the die cavities are arranged on two sides of the sub-runners, so that each die cavity can be fully filled, each die cavity can be compactly distributed, and the production cost of micro plastic products is reduced; meanwhile, the phenomenon of difficult demoulding or mould clamping can be prevented.

Description

Multi-part micro-plastic part injection mold

Technical Field

The invention relates to the technical field of injection molds, in particular to an injection mold for a multi-part micro plastic part.

Background

The design of the mold of the tiny plastic product (the size is about 2.5 mm) needs to comprehensively consider the molding effect and the production cost, the existing tiny plastic injection mold generally adopts a mode of one mold and multiple cavities to reduce the production cost, but the volume of the mold core cannot be reasonably utilized, so that the mold has larger volume or the number of the cavities is less, and the production cost of the tiny plastic product is increased;

meanwhile, when the existing micro plastic mold is demolded, demolding difficulty or mold clamping phenomenon often occurs, so that the production efficiency is low.

Disclosure of Invention

In view of the above, there is a need to provide a multi-part injection mold for micro plastic parts, which solves the technical problems of the prior art that the volume of the mold core is not reasonably utilized, the mold volume is larger or the number of the mold cavities is smaller, the production cost of the micro plastic product is increased, and the mold release difficulty or the mold clamping phenomenon often occurs.

In order to achieve the purpose, the invention provides a multi-part micro plastic part injection mold, which comprises an upper mold core, a lower mold core and a demolding mechanism, wherein the upper mold core is provided with a first cavity and a second cavity;

a main runner, a plurality of sub-runners and a plurality of cavities are formed between the lower die core and the upper die core, the center of the main runner is positioned under the pouring gate, each sub-runner is vertically intersected with the main runner and uniformly arranged along the length direction of the main runner, and each cavity is uniformly distributed on two sides of each sub-runner and is communicated with the sub-runners;

demoulding mechanism is including drawing material pole and a plurality of push rod, draw the material pole with lower mould benevolence sliding connection and part set up in the sprue, the upper end of drawing the material pole is formed with a spacing arch, the inclination of a spacing bellied lateral wall is greater than 90, each the push rod all with lower mould benevolence sliding connection and part set up in the sprue or in the subchannel.

Furthermore, the multi-part micro plastic part injection mold also comprises an upper template and a lower template; a first mounting groove is formed in the lower end face of the upper template, and the upper die core is detachably mounted in the first mounting groove; the upper end face of the lower template is provided with a second mounting groove, the lower mold core is detachably mounted in the second mounting groove, and when the upper template and the lower template are closed, the upper mold core and the lower mold core are attached.

Furthermore, the multi-part micro plastic part injection mold further comprises an upper mold base and a lower mold base, wherein the upper mold base is fixed on the upper end face of the upper mold plate, and the lower mold base is fixed on the lower end face of the lower mold plate.

Furthermore, the demoulding mechanism also comprises a guide sleeve and a guide pillar, wherein the guide sleeve is fixed on the upper template, and the guide pillar is fixed on the lower template and is inserted in the guide sleeve in a sliding manner.

Furthermore, a first abdicating hole for the pulling rod to pass through and a plurality of second abdicating holes for the push rods to pass through are formed in the lower template; the demoulding mechanism further comprises a push plate, the push plate is located between the lower template and the lower die base, and the push plate is fixedly connected with the material pulling rod and the push rods.

Furthermore, a guide hole is formed in the lower template, and the demolding mechanism further comprises a guide rod which is fixed on the push plate and is inserted into the guide hole in a sliding manner.

Further, the demoulding mechanism further comprises a return spring, the return spring is sleeved on the guide rod, one end of the return spring is abutted against the lower template, and the other end of the return spring is abutted against the push plate.

Furthermore, a cold material cavity is formed in the lower die core, the cold material cavity is located below the main runner and communicated with the main runner, and the upper end of the material pulling rod is located in the cold material cavity.

Furthermore, a plurality of reinforcing cavities which correspond to the push rods one to one are formed in the lower die core, the reinforcing cavities are located below the sub-runners and communicated with the sub-runners, and the upper ends of the push rods are arranged in the reinforcing cavities.

Furthermore, many parts mould an injection mold a little still includes cooling body, cooling body includes first cooling tube and second cooling tube, inlay in the first cooling tube in the upper die benevolence, the second cooling tube embedded with in the lower die benevolence.

Compared with the prior art, the technical scheme provided by the invention has the beneficial effects that: the main runner is arranged between the lower die core and the upper die core, the plurality of sub-runners which are vertically crossed with the main runner are uniformly arranged along the main runner, and the die cavities are arranged on two sides of the sub-runners, so that each die cavity can be fully filled, each die cavity can be compactly distributed, the volumes of the lower die core and the upper die core are well utilized, the volume of the die is reduced, and the production cost of micro plastic products is reduced; simultaneously, when the drawing of patterns, draw the material of congealing of the spacing bellied side of material pole to receive the spacing of spacing bellied slope lateral wall to make congeal the material and keep in lower mould benevolence one side when the drawing of patterns for the first time, the material of congealing in rethread each push rod promotes sprue and the subchannel, makes congeal the material and breaks away from lower mould benevolence, can prevent the phenomenon of drawing of patterns difficulty or card mould.

Drawings

FIG. 1 is a schematic perspective view of an embodiment of an injection mold for a multi-part micro plastic part according to the present invention;

FIG. 2 is a front view of the multi-part overmold injection mold of FIG. 1;

FIG. 3 is a cross-sectional view taken along section A-A of FIG. 2;

FIG. 4 is a cross-sectional view taken along section B-B of FIG. 3;

FIG. 5 is a cross-sectional view taken along section C-C of FIG. 3;

FIG. 6 is an enlarged partial view of region D of FIG. 5;

FIG. 7 is a schematic perspective view of the multi-part injection mold for micro plastic parts of FIG. 1 without the upper mold plate, the upper mold base and the upper mold core;

FIG. 8 is a schematic perspective view of the cooling mechanism of FIG. 1;

in the figure: 1-upper die core, 2-lower die core, 3-demoulding mechanism, 4-pouring gate, 5-aggregate, 6-upper template, 7-lower template, 8-cooling mechanism, 21-main runner, 22-branch runner, 23-die cavity, 31-pulling rod, 311-limit bump, 32-push rod, 33-guide sleeve, 34-guide column, 35-push plate, 36-guide rod, 37-reset spring, 61-upper die base, 71-lower die base, 72-guide hole, 81-first cooling pipe and 82-second cooling pipe.

Detailed Description

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate preferred embodiments of the invention and together with the description, serve to explain the principles of the invention and not to limit the scope of the invention.

Referring to fig. 1-5, the present invention provides an injection mold for a multi-part micro plastic part, which includes an upper mold core 1, a lower mold core 2 and a demolding mechanism 3.

Referring to fig. 3, a main runner 21, a plurality of sub-runners 22 and a plurality of cavities 23 are formed between the lower mold core 2 and the upper mold core 1, the center of the main runner 21 is located right below the pouring gate 4, each sub-runner 22 is vertically intersected with the main runner 21 and uniformly arranged along the length direction of the main runner 21, and each cavity 23 is uniformly arranged on two sides of each sub-runner 22 and communicated with the sub-runners 22. In this embodiment, a cavity distribution form of a die 48 cavity (including three different shapes, each shape corresponding to four sizes) is adopted, specifically, the shape of the cavity includes spherical, heart-shaped and polygonal parts, and the four sizes are respectively: 2.5mm, 2.75mm, 3mm, 3.5 mm.

In order to obtain a better filling effect and save raw materials, the main runner 21 is designed to be as short as possible, and the size of the main runner 21 of the mold is as follows, wherein the taper angle is generally equal to 2 degrees; the diameter d of the small end is equal to the diameter of a forming machine nozzle + (0.5-1); the radius SR of the hemispherical surface is equal to the radius + (1-2) of a forming machine nozzle; the length L is 68 mm; the diameter D of the big end is D +2Ltan 2/alpha is 7.6 mm. The shunt 22 of this embodiment is of circular cross-section and has a diameter D of 2.5 mm. In designing the runner 22, it is sufficient to consider how to minimize the loss of injection pressure, and only then the plastic material melt can reach the cavity of the mold at the fastest speed, so as to divide the plastic material melt to a larger point of the design as much as possible, but this value must be fully considered, if the design exceeds the limit size that it can be applied to, a large amount of air will be brought in during injection molding to cause poor molding of the plastic part, and if the design exceeds the limit size that it can be applied to, the too large size will increase the solidification of the casting system, thereby causing problems of prolonged cooling time and excessive raw material cost. The total length of the runners 22 in this embodiment is 14.5 mm. The gate of the embodiment is a rectangular side gate, and the pouring opening is arranged on the outline of the outer edge of the cavity 23.

Referring to fig. 5 to 7, the demolding mechanism 3 includes a material pulling rod 31 and a plurality of push rods 32, the material pulling rod 31 is slidably connected to the lower mold core 2 and is partially disposed in the main flow channel 21, a limiting protrusion 311 is formed at an upper end of the material pulling rod 31, an inclination angle of a side wall of the limiting protrusion 311 is greater than 90 °, and each push rod 32 is slidably connected to the lower mold core 2 and is partially disposed in the main flow channel 21 or the branch flow channel 22. In this embodiment, the number of the push rods 32 is 15, and the 15 push rods 32 are uniformly arranged below the main flow channel 21 and the sub flow channels 22.

According to the invention, the main runner 21 is arranged between the lower mold core 2 and the upper mold core 1, the plurality of sub-runners 22 vertically intersected with the main runner 21 are uniformly arranged along the main runner 21, and the cavities 23 are arranged on two sides of the sub-runners 22, so that the cavities 23 can be fully filled, the cavities 23 can be compactly distributed, the volumes of the lower mold core 2 and the upper mold core 1 are well utilized, the volume of the mold is reduced, and the production cost of a tiny plastic product is reduced; meanwhile, during demolding, the congealed material 5 on the side of the limiting protrusion 311 of the material pulling rod 31 is limited by the inclined side wall of the limiting protrusion 311, so that the congealed material 5 is kept on one side of the lower mold core 2 during first demolding, and the congealed material 5 in the main flow channel 21 and the branch flow channels 22 is pushed by the push rods 32, so that the congealed material 5 is separated from the lower mold core 2, and the phenomenon of difficult demolding or mold clamping can be prevented.

Further, referring to fig. 4 and 5, the multi-part micro plastic injection mold further includes an upper mold plate 6 and a lower mold plate 7; a first mounting groove is formed in the lower end face of the upper template 6, and the upper die core 1 is detachably mounted in the first mounting groove; and a second mounting groove is formed in the upper end surface of the lower template 7, the lower die core 2 is detachably mounted in the second mounting groove, and when the upper template 6 and the lower template 7 are combined, the upper die core 1 is attached to the lower die core 2. Through with upper mould benevolence 1 and lower mould benevolence 2 respectively demountable installation on cope match-plate pattern 6 and lower bolster 7 to conveniently change upper mould benevolence 1 and lower mould benevolence 2, improved the maintainability of mould.

Further, referring to fig. 4 and 5, the multi-part micro plastic injection mold further includes an upper mold base 61 and a lower mold base 71, the upper mold base 61 is fixed on the upper end surface of the upper mold plate 6, and the lower mold base 71 is fixed on the lower end surface of the lower mold plate 7. The upper die plate 6 is conveniently fixed on the injection molding machine by arranging the upper die holder 61, and the lower die plate 7 is conveniently fixed on a driving device (not shown) by arranging the lower die holder 71.

Further, referring to fig. 4 to 7, the demolding mechanism 3 further includes a guide sleeve 33 and a guide pillar 34, the guide sleeve 33 is fixed on the upper mold plate 6, and the guide pillar 34 is fixed on the lower mold plate 7 and is slidably inserted into the guide sleeve 33. Through the cooperation of the guide sleeve 33 and the guide post 34, the die closing and splitting processes of the upper template 6 and the lower template 7 can be guided, so that the accuracy of the die closing and splitting processes is ensured.

Further, referring to fig. 4 to 7, a first yielding hole for the pulling rod 31 to pass through and a plurality of second yielding holes for the pushing rods 32 to pass through are formed in the lower template 7; the demolding mechanism 3 further comprises a push plate 35, the push plate 35 is located between the lower template 7 and the lower die base 71, and the push plate 35 is fixedly connected with the material pulling rod 31 and the push rods 32. In the demolding process, after the upper template 6 is separated from the lower template 7, the push plate 35 is pushed, so that the material pulling rods 31 and the push rods 32 can be pushed, and the solidified materials 5 are separated from the lower mold core 2.

Further, referring to fig. 4 to 7, the lower mold plate 7 is further provided with a guide hole 72, the demolding mechanism 3 further includes a guide rod 36, and the guide rod 36 is fixed on the push plate 35 and is slidably inserted into the guide hole 72. The guide rod 36 is matched with the guide hole 72, so that the moving process of the push plate 35 is guided, and the accuracy of the moving process of the push plate 35 is improved.

Preferably, referring to fig. 4 to 7, the demolding mechanism 3 further includes a return spring 37, the return spring 37 is sleeved on the guide rod 36, one end of the return spring 37 abuts against the lower mold plate 7, the other end of the return spring 37 abuts against the push plate 35, and by providing the return spring 37, the push plate 35 can be tightly attached to the lower mold base 71 during mold closing, so that the positions of the material pulling rod 31 and each push rod 32 during mold closing are kept fixed, and the accuracy of the mold is improved.

Preferably, referring to fig. 5 and 6, a cold material cavity is formed in the lower mold core 2, the cold material cavity is located below the main flow channel 21 and is communicated with the main flow channel 21, the upper end of the material pulling rod 31 is located in the cold material cavity, and by arranging the cold material cavity, when filling, the melted liquid of the foremost part of the low-temperature front will enter the cold material cavity, so as to prevent the melted liquid of the low-temperature front from entering the mold cavity 23 to cause the quality degradation of the product.

Preferably, referring to fig. 5 and 6, a plurality of reinforcing cavities corresponding to the push rods 32 one to one are formed in the lower die core 2, each reinforcing cavity is located below the runner 22 and is communicated with the runner 22, the upper end of each push rod 32 is arranged in the reinforcing cavity, and the thickness of the solidified material 5 at the contact position with the push rod 32 is increased by arranging the reinforcing cavities, so that the push rod 32 is prevented from breaking the solidified material 5 in the demolding process to cause difficulty in demolding or mold clamping.

Further, referring to fig. 7 and 8, the multi-part micro plastic injection mold further includes a cooling mechanism 8, the cooling mechanism 8 includes a first cooling pipe 81 and a second cooling pipe 82, the first cooling pipe 81 is embedded in the upper mold core 1, and the second cooling pipe 82 is embedded in the lower mold core 2. Through setting up first cooling tube 81 and second cooling tube 82, when using, can last letting in microthermal running water in to first cooling tube 81 and second cooling tube 82 to can accelerate the condensation process of the liquid of moulding plastics, and can also prevent that the mould is overheated, prolong the life of mould.

For better understanding of the present invention, the operation of the injection mold for multi-part micro plastic parts provided by the present invention is described in detail below with reference to fig. 1 to 8: when the injection molding machine is used, after the upper template 6 and the lower template 7 are matched, injection molding liquid is injected into the mold through the pouring gate 4 by the injection molding machine, the injection molding liquid firstly reaches the main runner 21, then is divided into the branch runners 22, and then enters the cavities 23, meanwhile, low-temperature tap water is continuously introduced into the first cooling pipe 81 and the second cooling pipe 82, the injection molding liquid is cooled and solidified to form the solidified material 5, then the lower template 7 is driven by the driving device to be separated from the upper template 6, the solidified material 5 can be kept at one side of the lower template 7 under the action of the material pulling rod 31, then the pushing plate 35 is driven by the driving device to move upwards, the pushing plate 35 drives the pushing rods 32 to move upwards, so that the solidified material 5 can be ejected out, and finally, all micro plastic parts in the solidified material 5 are separated, and the manufacturing of multi-part micro plastic parts is completed.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.

Claims

1. An injection mold for multi-part micro plastic parts is characterized by comprising an upper mold core, a lower mold core and a demolding mechanism;

2. The injection mold of the multi-part micro plastic part of claim 1, further comprising an upper mold plate and a lower mold plate; a first mounting groove is formed in the lower end face of the upper template, and the upper die core is detachably mounted in the first mounting groove; the upper end face of the lower template is provided with a second mounting groove, the lower mold core is detachably mounted in the second mounting groove, and when the upper template and the lower template are closed, the upper mold core and the lower mold core are attached.

3. The injection mold for the multi-part micro plastic part as claimed in claim 2, further comprising an upper mold base and a lower mold base, wherein the upper mold base is fixed on the upper end surface of the upper mold plate, and the lower mold base is fixed on the lower end surface of the lower mold plate.

4. The injection mold for multi-part micro plastic parts as claimed in claim 2, wherein the mold-releasing mechanism further comprises a guide sleeve and a guide post, the guide sleeve is fixed on the upper mold plate, and the guide post is fixed on the lower mold plate and slidably inserted into the guide sleeve.

5. The injection mold for the multi-part micro plastic part as claimed in claim 3, wherein the lower template is provided with a first abdicating hole for the pulling rod to pass through and a plurality of second abdicating holes for the pushing rods to pass through;

the demoulding mechanism further comprises a push plate, the push plate is located between the lower template and the lower die base, and the push plate is fixedly connected with the material pulling rod and the push rods.

6. The injection mold for the multi-part micro plastic part as claimed in claim 5, wherein the lower mold plate further comprises a guide hole, and the demolding mechanism further comprises a guide rod fixed on the push plate and slidably inserted into the guide hole.

7. The injection mold for the multi-part micro plastic part according to claim 6, wherein the demolding mechanism further comprises a return spring, the return spring is sleeved on the guide rod, one end of the return spring is abutted with the lower mold plate, and the other end of the return spring is abutted with the push plate.

8. The injection mold for multiple micro plastic parts according to claim 1, wherein a cooling cavity is formed in the lower mold core, the cooling cavity is located below the main runner and is communicated with the main runner, and the upper end of the material pulling rod is located in the cooling cavity.

9. The injection mold for multi-part micro plastic parts according to claim 1, wherein a plurality of reinforcing cavities corresponding to the push rods are formed in the lower mold core, each reinforcing cavity is located below the runner and communicated with the runner, and the upper end of each push rod is arranged in the reinforcing cavity.

10. The injection mold for multiple micro-molded parts according to claim 1, further comprising a cooling mechanism, wherein the cooling mechanism comprises a first cooling pipe and a second cooling pipe, the first cooling pipe is embedded in the upper mold core, and the second cooling pipe is embedded in the lower mold core.