CN220242277U

CN220242277U - Mould for forming precise plastic gear

Info

Publication number: CN220242277U
Application number: CN202321525358.7U
Authority: CN
Inventors: 朱贵勇
Original assignee: Suzhou Yibaian Machinery Technology Co ltd
Current assignee: Suzhou Yibaian Machinery Technology Co ltd
Priority date: 2023-06-15
Filing date: 2023-06-15
Publication date: 2023-12-26
Anticipated expiration: 2033-06-15

Abstract

The utility model discloses a die for forming a precise plastic gear, which comprises a lower die holder, an upper die holder and a die carrier, wherein a forming cavity is formed in the lower die holder, an electric heating wire is arranged on the outer side of the forming cavity, three pouring gates are arranged on the upper die holder, an air passage is formed in the lower die holder, and a pneumatic base is arranged at the bottom end of the lower die holder; the electric heating wire heats the molding cavity, the injection molding material is heated uniformly, the inside of the molding cavity is kept at uniform temperature, so that the material is contracted at uniform and controlled speed, the difference of dimensional tolerance caused by uneven contraction is eliminated, the precision of gear molding is improved, the pneumatic base is pumped before injection molding, the inside of the molding cavity is in a negative pressure state, the pressure difference of two ends of a pouring gate is increased, mold filling is facilitated, injection molding is performed on three pouring gates simultaneously, injection molding is performed in a shorter molding time under a smaller injection pressure, mold filling is further facilitated, compressed gas is introduced into the air channel during demolding by the air pump assembly, and the gas pushes the demolding module to move upwards for demolding.

Description

Mould for forming precise plastic gear

Technical Field

The utility model relates to the technical field of gear forming dies, in particular to a die for forming a precise plastic gear.

Background

Injection molds, also known as plastic injection molding molds, are commonly used on injection machines. Injection molding refers to a process in which a completely molten plastic is stirred by a screw at a certain temperature, injected into a mold cavity under high pressure, and then cooled and solidified to obtain a finished product. Plastic parts are more commonly used in people's daily lives, such as plastic gears, which have many advantages over metal gears. Compared with metal gears, they are lighter in weight, less inertial, and less noisy in operation, and because of the more teeth on plastic gears, there is a higher requirement for the mold filling capability in injection molding.

In the injection molding process of the gear, uneven heating can lead to uneven shrinkage, and then difference of dimensional tolerance can be caused, precision of gear molding is reduced, if air is detained in a molding cavity of a mold in the injection molding process, uneven pressure of the mold cavity can be caused, tolerance can be influenced in the above conditions, precision of gear molding is to be improved, contact area between the molded gear and the mold cavity is large due to the fact that the number of teeth of the gear is large, and demolding is inconvenient.

Disclosure of Invention

The utility model aims to provide a die for forming a precise plastic gear, which solves the problems in the prior art.

In order to achieve the above purpose, the present utility model provides the following technical solutions: the utility model provides a mould for precision plastic gear shaping, includes die holder, upper die base and die carrier, set up the shaping die cavity on the die holder, the outside of shaping die cavity is provided with the heating wire, be provided with three runner on the upper die base, the inside of die holder is provided with the air flue, pneumatic base is installed to the bottom of die holder.

The inner part of the air passage is provided with a fixing rod, the upper end of the fixing rod is provided with a spring, the upper end of the spring is provided with a demoulding block, and the demoulding block is in sliding connection with the air passage.

Wherein, three pouring gates are uniformly arranged along the circumferential direction of the forming cavity at intervals.

The cooling water inlet pipe is arranged above one side of the lower die holder, the cooling water return pipe is arranged below the other side of the lower die holder, and the cooling pipe is arranged inside the lower die holder.

The cooling pipes are arranged in a spiral line structure and are positioned on the outer side of the forming cavity.

The electric cylinder is arranged at the top end of the inner side of the die frame and comprises an electric push rod, a driving shaft is arranged at the top end of the upper die holder, and the driving shaft is fixedly connected with the electric push rod.

And limiting holes are formed in the corners of the upper end face of the lower die holder.

And the corners of the lower end surface of the upper die seat are provided with limiting columns, and the limiting columns and the limiting holes are in one-to-one correspondence.

Compared with the prior art, the utility model has the beneficial effects that:

1. the electric heating wire heats the forming cavity, the injection molding material is heated uniformly, and the interior of the forming cavity is kept at uniform temperature, so that the material can shrink at uniform and controlled speed, the difference of dimensional tolerance caused by uneven shrinkage is eliminated, and the precision of gear forming is improved.

2. According to the utility model, the pneumatic base is pumped before injection molding, so that the inside of the molding cavity is in a negative pressure state, the pressure difference at two ends of the pouring gate is increased, the mold is conveniently filled, three small pouring gates are simultaneously used for injection molding, the injection molding of the gear is realized in a shorter molding time under a smaller injection pressure, the injection molding efficiency is improved, and the mold is further conveniently filled.

3. When the air pump assembly is used for demolding, compressed air is introduced into the air passage, the air pushes the demolding module to move upwards, the spring is stretched, the air enters the molding cavity through the air passage, thrust is applied from the bottom of the molding part, and the molding part is ejected from the molding cavity, so that demolding is realized.

Drawings

FIG. 1 is a three-dimensional perspective view of a lower die holder and an upper die holder of the utility model;

FIG. 2 is a front view of the present utility model;

FIG. 3 is an enlarged view of a portion of the area A of FIG. 1;

FIG. 4 is a schematic view of the structure of the airway of the present utility model;

FIG. 5 is a schematic view of the cooling tube of the present utility model.

In the figure: 1. a lower die holder; 2. an upper die holder; 3. a molding cavity; 4. heating wires; 5. a gate; 6. a pneumatic base; 7. an airway; 8. a fixed rod; 9. a spring; 10. removing the module; 11. a cooling water inlet pipe; 12. a cooling water return pipe; 13. a cooling tube; 14. a mould frame; 15. an electric cylinder; 16. a drive shaft; 17. a limiting hole; 18. and a limit column.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

Referring to fig. 1-5, the present utility model provides a technical solution: the utility model provides a mould for precision plastic gear shaping, including die holder 1, upper die holder 2 and die carrier 14, set up the shaping chamber 3 on the die holder 1, the outside in shaping chamber 3 is provided with heating wire 4, be provided with three runner 5 on the upper die holder 2, the inside of die holder 1 is provided with air flue 7, pneumatic base 6 is installed to the bottom of die holder 1, the heating wire 4 is built-in to die holder 1, heating wire 4 circular telegram intensification heats the shaping chamber 3 of die holder 1, in injection moulding process, improve the heating degree of consistency and the mobility of melting material, make the melting material can not the dead angle fill in shaping chamber 3 inside, and cool down the shaping at shaping chamber 3, the injection moulding shaping material is heated evenly, the inside even temperature of holding of shaping chamber 3, in order to allow the material shrink with even, controlled speed, eliminate the difference of dimensional tolerance because of shrink inequality, improve the gear shaping.

Wherein, the distribution shape of the heating wire 4 is matched with the shape of the forming cavity 3, thereby improving the heating uniformity of the forming cavity 3.

The three gates 5 are used for injection molding at the same time, so that injection molding of the gear is realized in a shorter molding time under a smaller injection pressure, and injection molding efficiency is improved.

The large gate 5 is divided into three small gates 5 for injection molding, and the small gates 5 can increase the flow velocity of materials when passing through, so that the two ends of the gates 5 have larger pressure difference, the apparent viscosity of the molten material can be reduced, and the mold filling is easy.

Wherein, the internally mounted of air flue 7 has dead lever 8, and spring 9 is installed to the upper end of dead lever 8, and demoulding piece 10 is installed to the upper end of spring 9, and sliding connection between demoulding piece 10 and the air flue 7.

Wherein, pneumatic base 6 is connected to the one end of air flue 7, and pneumatic base 6 embeds has air pump assembly, before moulding plastics, after the compound die, the inside unnecessary air of drawing of shaping chamber 3 makes shaping chamber 3 inside form the negative pressure, and this negative pressure overcomes the elasticity of spring 9, compression spring 9 makes drawing of patterns piece 10 be in the state as shown in fig. 4, and shaping chamber 3 this moment is complete gear shaping chamber 3, and the intracavity is negative pressure state, has further increased the pressure differential at runner 5 both ends, has made things convenient for the filling mould, improves gear shaping quality, improves gear shaping's precision.

After the gear is cooled and molded and opened, the air pump assembly works, compressed air is introduced into the air channel 7, the compressed air has a certain thrust, the thrust pushes the demolding module 10 to move up the demolding block 10, the spring 9 is stretched, the compressed air enters the molding cavity 3 through the upper end channel of the air channel 7, the thrust is applied from the bottom of the gear molding part, the gear molding part is ejected out of the molding cavity 3, and demolding is achieved.

Wherein, need not manual drawing of patterns, and the drawing of patterns mode is simple, eliminates the deflection that leads to when manual drawing of patterns, further improves the precision of gear shaping.

Wherein, three runner 5 evenly set up along the circumferencial direction interval of shaping chamber 3, under less injection pressure, in the short shaping time, realize the injection molding of gear, improved injection molding efficiency.

Wherein, a cooling water inlet pipe 11 is arranged above one side of the lower die holder 1, a cooling water return pipe 12 is arranged below the other side of the lower die holder 1, and a cooling pipe 13 is arranged inside the lower die holder 1.

Wherein the cooling tube 13 is arranged in a spiral structure, and the cooling tube 13 is positioned outside the forming cavity 3.

The cooling water enters the cooling pipe 13 through the cooling water inlet pipe 11 after injection molding is completed, flows in the cooling pipe 13, exchanges heat with the molding cavity 3, cools injection molding parts, improves cooling efficiency, and returns the used cooling water through the cooling water return pipe 12.

The top of the inner side of the die carrier 14 is provided with an electric cylinder 15, the electric cylinder 15 comprises an electric push rod, the top of the upper die holder 2 is provided with a driving shaft 16, and the driving shaft 16 is fixedly connected with the electric push rod.

Wherein, limit holes 17 are arranged at the corners of the upper end face of the lower die holder 1.

The corners of the lower end face of the upper die holder 2 are provided with limiting columns 18, and the limiting columns 18 and the limiting holes 17 are in one-to-one correspondence.

The electric cylinder 15 works to drive the upper die holder 2 to axially move through the driving shaft 16, the upper die holder 2 moves downwards, the limit post 18 of the upper die holder 2 is embedded into the limit hole 17 of the lower die holder 1, die assembly is achieved, the upper die holder 2 moves upwards, and the limit post 18 of the upper die holder 2 moves out of the limit hole 17 of the lower die holder 1, and die opening is achieved.

Working principle: when in use, the electric cylinder 15 works to drive the upper die holder 2 to move downwards, the limit post 18 of the upper die holder 2 is embedded into the limit hole 17 of the lower die holder 1 to realize die assembly, the heating wire 4 is electrified to heat the forming cavity 3 of the lower die holder 1, the pneumatic base 6 works to extract redundant air in the forming cavity 3 to form negative pressure in the forming cavity 3, the negative pressure overcomes the elasticity of the spring 9 to compress the spring 9, the demoulding block 10 is in a state shown in figure 4, the forming cavity 3 at the moment is a complete gear forming cavity 3, and the cavity is in a negative pressure state, during injection molding, the three pouring gates 5 are simultaneously used for injection molding, the big pouring gates 5 are divided into the three small pouring gates 5 for injection molding, the small pouring gates 5 can increase the flow velocity when materials pass through, so that the two ends of the pouring gates 5 have larger pressure difference, the viscosity of the melting stock can be reduced, the negative pressure condition in the cavity further increases the pressure difference, the heating wire 4 heats the molding cavity 3 to improve the heating uniformity and fluidity of the molten material, the injection molding material is heated uniformly to eliminate the difference of dimensional tolerance caused by uneven shrinkage, after injection molding is finished, the cooling molding is carried out, the heating wire 4 is powered off, cooling water enters the cooling pipe 13 through the cooling water inlet pipe 11 and flows in the cooling pipe 13, heat exchange is carried out between the cooling water and the molding cavity 3, the injection molding piece is cooled, the cooling efficiency is improved, the used cooling water flows back through the cooling water return pipe 12, the air pump assembly works after the gear injection molding piece is molded, compressed gas is introduced into the air channel 7, the compressed gas has a certain thrust, the thrust pushes the stripping module 10 to enable the stripping block 10 to move upwards, the spring 9 is stretched, the compressed gas enters the molding cavity 3 through the upper end channel of the air channel 7, the thrust is applied from the bottom of the gear molding piece, and ejecting the gear forming part from the inside of the forming cavity 3 to realize demoulding.

Although embodiments of the present utility model have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the utility model, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The utility model provides a mould for precision plastic gear shaping, includes die holder (1), upper die base (2) and die carrier (14), its characterized in that: the novel plastic injection molding machine is characterized in that a molding cavity (3) is formed in the lower die holder (1), an electric heating wire (4) is arranged on the outer side of the molding cavity (3), three pouring gates (5) are arranged on the upper die holder (2), an air passage (7) is formed in the lower die holder (1), and a pneumatic base (6) is arranged at the bottom end of the lower die holder (1).

2. The mold for molding a precision plastic gear according to claim 1, wherein: the inside mounting of air flue (7) has dead lever (8), spring (9) are installed to the upper end of dead lever (8), take off module (10) are installed to the upper end of spring (9), and sliding connection between drawing of patterns piece (10) and air flue (7).

3. The mold for molding a precision plastic gear according to claim 1, wherein: the three pouring gates (5) are uniformly arranged at intervals along the circumferential direction of the forming cavity (3).

4. The mold for molding a precision plastic gear according to claim 1, wherein: the cooling water inlet pipe (11) is arranged above one side of the lower die holder (1), the cooling water return pipe (12) is arranged below the other side of the lower die holder (1), and the cooling pipe (13) is arranged inside the lower die holder (1).

5. The mold for molding a precision plastic gear according to claim 4, wherein: the cooling pipe (13) is arranged in a spiral structure, and the cooling pipe (13) is positioned outside the forming cavity (3).

6. The mold for molding a precision plastic gear according to claim 1, wherein: an electric cylinder (15) is arranged at the top end of the inner side of the die frame (14), the electric cylinder (15) comprises an electric push rod, a driving shaft (16) is arranged at the top end of the upper die holder (2), and the driving shaft (16) is fixedly connected with the electric push rod.

7. The mold for molding a precision plastic gear according to claim 1, wherein: limiting holes (17) are formed in the corners of the upper end face of the lower die holder (1).

8. The mold for molding a precision plastic gear according to claim 7, wherein: limiting columns (18) are arranged at corners of the lower end face of the upper die holder (2), and the limiting columns (18) and the limiting holes (17) are in one-to-one correspondence.