CN223058268U - Mold shrinkage structure for forming internal threads of plastic parts - Google Patents

Abstract

The utility model relates to the technical field of molding dies for plastic parts, in particular to a die inward shrinking structure for molding internal threads of plastic parts, which comprises a base assembly and a core assembly, wherein the base assembly is arranged on an external molding die, the core assembly is movably connected with the base assembly, the core assembly is provided with a wedge-shaped shovel base and a movable insert, one end outer wall of the movable insert is provided with a molding convex strip for molding the internal threads of the plastic parts, the other end of the movable insert is provided with a bottom sliding block, the bottom sliding block is in sliding connection with the base assembly, the wedge-shaped shovel base drives the movable insert to translate a certain distance towards the central axis of the wedge-shaped shovel base, and therefore the molding convex strip is separated from the internal threads of the inner side walls of the plastic parts. In conclusion, the forming and demolding of the internal thread of the plastic part can be optimized, the size of the mold can be reduced, the injection molding time can be shortened, and meanwhile, the corresponding processing cost can be saved.

Description

Mold shrinkage structure for forming internal threads of plastic parts

Technical Field

The utility model relates to the technical field of molding dies for plastic parts, in particular to a die shrinking structure for molding internal threads of plastic parts.

Background

The injection mold is a tool for producing plastic products, and generally comprises a movable mold block and a fixed mold block, a molding cavity and a plastic runner system are formed between the movable mold block and the movable mold block, the movable mold block and the fixed mold block are clamped in a mold during injection molding, molten plastic flows into the runner system from an injection port and flows into the molding cavity at the moment and is cooled and molded in the cavity, meanwhile, the molten plastic is cooled in the runner system to form runner system solidification materials, after molding a plastic part, the movable mold block and the fixed mold block are opened, the plastic part is ejected out of the mold cavity through an ejection system and leaves the mold, and when the injection molding is needed again, the process can be repeated.

For some special plastic parts needing to be molded with internal threads, the existing mold generally adopts a traditional gear for demolding, but the traditional gear mold has the defects of high processing cost, long molding time and large occupied mold space, so that improvement is needed.

For example, chinese patent document CN219705945U discloses an internal thread injection mold which is convenient for demolding. The internal thread injection mold convenient for demolding comprises a movable mold assembly, a fixed mold assembly and a thread demolding assembly, wherein the movable mold assembly comprises a movable mold base and a forming mold core arranged on the movable mold base, the fixed mold assembly comprises a fixed mold base, a forming column and a forming sleeve, the forming column is arranged on the fixed mold base, one end of the forming column, which is close to the movable mold assembly, is provided with a forming surface, the forming sleeve is sleeved outside the forming column, one end of the forming sleeve, which is close to the movable mold assembly, is provided with forming threads on the side wall, the other end of the forming sleeve is in threaded connection with the fixed mold base, the thread demolding assembly comprises power components and driven gears, the number of the driven gears corresponds to that of the forming sleeve, the driven gears are sleeved outside the forming sleeve and are fixedly connected with the forming sleeve, and the power components are arranged on the fixed mold base and used for driving the driven gears to rotate.

As shown in fig. 1 and 6 of the above patent documents, the size of the conventional gear demoulding structure is excessively large, which results in excessively large occupation space of the whole mould, which is inconvenient to reduce the volume of the mould and the size of the mould.

Disclosure of utility model

The utility model aims to overcome the defects of the prior art and provides a technical scheme capable of solving the problems.

The utility model provides a die retraction structure for forming internal threads of a plastic part, which comprises a base component and a core component, wherein the base component is arranged on an external forming die, the core component is movably connected with the base component, the core component is provided with a wedge-shaped shovel base and a movable insert, the outer wall of one end of the movable insert is provided with a forming convex strip for forming the internal threads of the plastic part, the other end of the movable insert is provided with a bottom sliding block, the bottom sliding block is in sliding connection with the base component, and the wedge-shaped shovel base drives the movable insert to translate a certain distance towards the central axis of the wedge-shaped shovel base, so that the forming convex strip is separated from the internal threads of the inner side wall of the plastic part.

According to the wedge-shaped shovel base, the wedge-shaped shovel base is provided with the inclined guide groove towards one side of the movable insert, the part, corresponding to the inclined guide groove, of the movable insert is provided with the inclined slide rail, the inclined slide rail and the inclined guide groove are embedded with each other to form sliding connection, and when the wedge-shaped shovel base moves along the central axis of the wedge-shaped shovel base, the movable insert can be driven to translate for a certain distance perpendicular to the central axis of the wedge-shaped shovel base.

As a further scheme of the utility model, the movable insert is provided with three circular arc spliced blocks and three sector spliced blocks, and the circular arc spliced blocks and the sector spliced blocks are mutually intersected and mutually abutted so as to form a circular female die for forming an inner concave space of the plastic part.

As a further scheme of the utility model, the angle of the inclined included angle formed by the inclined slide rail of the fan-shaped spliced block and the central axis of the wedge-shaped shovel base is larger than the angle of the inclined included angle formed by the inclined slide rail of the arc-shaped spliced block and the central axis of the wedge-shaped shovel base.

As a further scheme of the utility model, the base component is provided with a retraction fixing plate and a retraction pressing plate, the retraction pressing plate is fixedly connected with the retraction fixing plate, one side facing the retraction fixing plate is provided with a translation groove which is adapted to a bottom sliding block, and the bottom sliding block is connected with the retraction fixing plate in a sliding way and is limited by the translation groove of the retraction pressing plate.

As a further scheme of the utility model, the translation groove is provided with a first groove and a second groove, the first groove is used for limiting the bottom sliding block of the circular splicing block, and the second groove is used for limiting the bottom sliding block of the fan-shaped splicing block.

The utility model also provides an injection mold, wherein the mold shrinking structure for forming the internal thread of the plastic part is arranged in the injection mold, so that the internal thread of the injection product is subjected to injection molding operation.

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

1. through setting up corresponding core subassembly in the mould shrink structure, utilize wedge shovel base and movable mold insert's cooperation each other, make wedge shovel base can drive movable mold insert, make its inwards move certain distance, form the shrink state to make shaping sand grip can break away from the internal thread part of plastic part, thereby accomplish holistic drawing of patterns process. The internal thread can be molded and demolded by realizing relatively smaller mold size, the injection molding time can be shortened, and the production efficiency is improved.

2. The wedge-shaped shovel base moves synchronously along with the movable module during die assembly or die stripping by utilizing the inclined guide groove of the wedge-shaped shovel base and the inclined slide rail of the movable insert, so that the movable insert can be driven to perform corresponding inward contraction operation or outward expansion operation. Thereby forming the internal thread inside the plastic part and simultaneously facilitating the demoulding operation.

3. The three arc splicing blocks and the three fan-shaped splicing blocks are arranged, and the arc splicing blocks and the fan-shaped splicing blocks can be combined to form an integral insert female die by utilizing the difference of corresponding inclined included angles, and can be respectively contracted during demolding, so that the demolding operation process is completed.

Therefore, through the improvement, the utility model can provide a die shrinking structure for forming the internal thread of the plastic part, so that the die shrinking structure can optimize the forming and demoulding of the internal thread of the plastic part, not only can reduce the size of the die, but also can shorten the injection molding time, and simultaneously can save the corresponding processing cost.

Additional aspects and advantages of the utility model will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the utility model.

Drawings

In order to more clearly illustrate the embodiments of the utility model or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the description below are only some embodiments of the utility model, and that other drawings can be obtained according to these drawings without inventive faculty for a person skilled in the art.

FIG. 1 is a schematic illustration of the base assembly and core assembly of the present utility model;

FIG. 2 is a schematic view of the structure of the present utility model when the circular arc segments and the fan segments are assembled;

FIG. 3 is a schematic diagram of the structure of the utility model during the mold opening process of the circular arc segments and the sector segments;

FIG. 4 is a schematic view of the structure of the circular arc segment and the sector segment of the present utility model after being opened;

FIG. 5 is a schematic view of the movable insert of the present utility model;

FIG. 6 is a schematic cross-sectional view of a diagonal channel of the present utility model;

FIG. 7 is a schematic cross-sectional view of a wedge shovel base and a movable insert of the present utility model;

fig. 8 is a schematic structural diagram of a first groove and a second groove according to the present utility model.

Reference numerals and names in the drawings are as follows:

10 base components, 11 inward shrinking fixing plates, 12 inward shrinking pressing plates, 13 translational grooves, 14 first grooves, 15 second grooves, 20 core components, 21 wedge-shaped shovel bases, 22 oblique guide grooves, 30 movable inserts, 31 forming convex strips, 32 bottom sliding blocks, 33 oblique sliding rails, 41 arc blocks, 42 sector blocks and 50 plastic parts.

Detailed Description

The following description of the technical solutions in the embodiments of the present utility model will be clear and complete, and it is obvious that the described embodiments 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 to 8, in an embodiment of the present utility model, a mold shrinking structure for forming an internal thread of a plastic part includes a base assembly 10 and a core assembly 20, wherein the base assembly 10 is mounted on an external forming mold, the core assembly 20 is movably connected to the base assembly 10, the core assembly 20 is provided with a wedge-shaped shovel 21 and a movable insert 30, an outer wall of one end of the movable insert 30 is provided with a forming convex strip 31 for forming the internal thread of the plastic part 50, and the other end of the movable insert 30 is provided with a bottom sliding block 32, the bottom sliding block 32 is slidably connected to the base assembly 10, and the wedge-shaped shovel 21 drives the movable insert 30 to translate a certain distance toward a central axis of the wedge-shaped shovel 21, so that the forming convex strip 31 is separated from the internal thread of the inner side wall of the plastic part 50.

In particular, in the field of injection molding molds, corresponding optimization is generally performed according to the specific structure of the plastic device to be molded and produced. However, the internal thread is inconvenient to implement because of its special nature, which requires a corresponding hollowing operation on the inner side wall of the product of the plastic part 50. Later, a demoulding structure combining the gear and the telescopic cylinder is adopted, so that the demoulding structure can carry out forming operation on the internal thread on the inner side wall of the plastic part 50, and meanwhile, the gear can be utilized to drive the corresponding forming thread to rotate, so that the part of the internal thread structure is withdrawn. However, the gear screw and the telescopic cylinder are relatively complex in structure and relatively oversized, so that the die occupies too large space, meanwhile, the forming time is too long, the processing cost is too high, and the energy-saving and production optimization operation is not facilitated.

Therefore, after development, the present utility model proposes a mold retraction structure for forming an internal thread of a plastic part, and the core assembly 20 provided in the mold retraction structure is utilized to enable the wedge-shaped shovel base 21 and the movable insert 30 to cooperate with each other, so that the wedge-shaped shovel base 21 can drive the movable insert 30 to move inwards by a certain distance to form a retraction state, and thus the forming raised strip 31 can be separated from the internal thread portion of the plastic part 50, and the overall demoulding process is completed. The internal thread can be molded and demolded by realizing relatively smaller mold size, the injection molding time can be shortened, and the production efficiency is improved.

As shown in fig. 5 and 6, preferably, a slant guide groove 22 is provided on a side of the wedge-shaped shovel base 21 facing the movable insert 30, a slant slide rail 33 is provided on a portion of the movable insert 30 corresponding to the slant guide groove 22, the slant slide rail 33 and the slant guide groove 22 are engaged with each other to form a sliding connection, and when the wedge-shaped shovel base 21 moves along the central axis thereof, the movable insert 30 can be driven to translate a certain distance perpendicular to the central axis of the wedge-shaped shovel base 21.

Specifically, the oblique guide groove 22 of the wedge-shaped shovel base 21 and the oblique slide rail 33 of the movable insert 30 are utilized, so that the wedge-shaped shovel base 21 moves synchronously along with the movable module during mold assembly or demolding, and the movable insert 30 can be driven to perform corresponding inward contraction movement or outward expansion movement. Thus forming the internal threads of the plastic part 50 and facilitating the demolding operation. The cooperation between the oblique guide groove 22 and the oblique sliding rail 33 can enable the wedge-shaped shovel base 21 to move along the axial direction of the wedge-shaped shovel base 21, and drive the corresponding movable insert 30 to move along the radial direction of the wedge-shaped shovel base 21, so that the internal thread is formed or demoulded.

As shown in fig. 2 to 5, it is preferable that the movable insert 30 is provided with three circular arc segments 41 and three sector segments 42, and the circular arc segments 41 and the sector segments 42 cross each other and abut each other, thereby forming a circular female mold insert for molding an inner concave space of the plastic part 50.

Specifically, in order to make the movable insert 30 perform the forming operation on the female screw by forming the circular female die insert and perform the retracting movement to complete the demolding operation, the movable insert 30 may be configured as three circular arc segments 41 of the same size and three circular sector segments 42 of the same size, wherein the circular arc portions of the circular arc segments 41 face the outer side of the movable insert 30, thereby forming the outer side wall of the movable insert 30. While the short side portions of the segment segments 42 also face the outside of the movable insert 30 and have a certain bending amplitude, thereby forming the outside wall of the movable insert 30.

Next, the portions of the circular arc segments 41 and the sector segments 42 forming the outer side wall of the movable insert 30 are respectively provided with corresponding molding protruding strips 31, and all the molding protruding strips 31 can be combined to form an integral protruding strip of the internal thread of the molded plastic part 50.

Again, the long side portion of the segment 42 faces the inner side of the movable insert 30, and the diagonal slide rail 33 is also provided at the long side portion of the segment 42 so as to be movable toward the inside of the movable insert 30 by the driving of the diagonal guide groove 22. Similarly, the portion of the circular arc segment 41 facing the inner side of the movable insert 30 is also provided with a corresponding oblique slide rail 33, so that it can move toward the inner side of the movable insert 30 under the driving of the oblique guide groove 22. Thereby accomplishing the demolding operation of the female screw of the molding 50.

As shown in fig. 6 and 7, preferably, the angle of the inclined sliding rail 33 of the fan-shaped segment 42 and the central axis of the wedge-shaped shovel base 21 is larger than the angle of the inclined sliding rail 33 of the circular arc segment 41 and the central axis of the wedge-shaped shovel base 21.

Specifically, during mold opening, that is, when the wedge-shaped shovel base 21 moves in a direction away from the plastic part 50, the fan-shaped split blocks 42 can be driven to translate a certain distance towards the central axis of the wedge-shaped shovel base 21, so that a certain space is provided for the arc split blocks 41, the arc split blocks 41 can translate a certain distance towards the central axis of the wedge-shaped shovel base 21, and the movable insert 30 is separated from the inner side wall of the plastic part 50, so that demolding operation is performed. And simultaneously, the molding convex strips 31 on the movable insert 30 can be separated from the internal threads on the inner side wall of the plastic part 50, so that the operation of shrinking the die is completed.

Secondly, contrary to the above operation, when the mold is closed, that is, when the wedge-shaped shovel 21 moves in a direction approaching to the mold 50, the circular arc segment 41 is driven to be firstly abutted against the inner side wall of the mold 50, then the sector segment 42 is continuously translated to a certain distance toward the inner side wall of the mold 50 and abutted against the inner side wall of the mold 50, so that the sector segment 42 and the circular arc segment 41 are abutted against each other to form a cylindrical integral movable insert 30, the internal cavity of the mold 50 is molded, and meanwhile, the molding raised line 31 arranged on the circular arc segment can also mold the internal thread of the inner wall of the mold 50.

As shown in fig. 5 to 7, the base assembly 10 is preferably provided with a retracted fixing plate 11 and a retracted pressing plate 12, wherein the retracted pressing plate 12 is fixedly connected to the retracted fixing plate 11, a translation groove 13 adapted to a bottom sliding block 32 is provided on a side facing the retracted fixing plate 11, and the bottom sliding block 32 is slidably connected to the retracted fixing plate 11 and is limited by the translation groove 13 of the retracted pressing plate 12.

Specifically, in order to make the translation direction of the movable insert 30 more accurate, a corresponding translation groove 13 may be further provided at a corresponding position of the inner compression plate 12, so that the movable insert 30 can only move in parallel in the translation groove 13.

As shown in fig. 8, preferably, the translation groove 13 is provided with a first groove 14 and a second groove 15, the first groove 14 is used for limiting the bottom slider 32 of the circular arc segment 41, and the second groove 15 is used for limiting the bottom slider 32 of the sector segment 42.

Specifically, in order to guide the movement of the movable insert 30, the first recess 14 and the second recess 15 may be provided according to the size of the bottom slider 32. Since the bottom slider 32 of the segment 42 is relatively small, a relatively small second recess 15 can be provided. Also, since the bottom slider 32 of the circular arc segment 41 is relatively large, a relatively large first groove 14 may be provided.

It will be evident to those skilled in the art that the utility model is not limited to the details of the foregoing illustrative embodiments, and that the present utility model may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the utility model being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims (7)

1. The die shrinking structure for forming the internal threads of the plastic parts is characterized by comprising a base assembly (10) and a core assembly (20), wherein the base assembly (10) is arranged on an external forming die, the core assembly (20) is movably connected to the base assembly (10), the core assembly (20) is provided with a wedge-shaped shovel base (21) and a movable insert (30), one end outer wall of the movable insert (30) is provided with a forming convex strip (31) for forming the internal threads of the plastic parts (50), the other end of the movable insert is provided with a bottom sliding block (32), the bottom sliding block (32) is slidably connected to the base assembly (10), and the wedge-shaped shovel base (21) drives the movable insert (30) to translate a certain distance towards the central axis of the wedge-shaped shovel base (21), so that the forming convex strip (31) is separated from the internal threads of the inner side walls of the plastic parts (50).

2. The mold shrinkage structure for forming the internal threads of the plastic parts according to claim 1, wherein an oblique guide groove (22) is formed on one side of the wedge-shaped shovel base (21) facing the movable insert (30), an oblique sliding rail (33) is arranged at a position of the movable insert (30) corresponding to the oblique guide groove (22), the oblique sliding rail (33) and the oblique guide groove (22) are embedded with each other to form sliding connection, and when the wedge-shaped shovel base (21) moves along the central axis of the wedge-shaped shovel base (21), the movable insert (30) can be driven to translate for a certain distance perpendicular to the central axis of the wedge-shaped shovel base (21).

3. A female mold structure for forming female threads of a plastic part according to claim 2, wherein the movable insert (30) is provided with three circular arc segments (41) and three sector segments (42), and the circular arc segments (41) and the sector segments (42) are intersected with each other and abutted against each other, thereby forming a circular female mold for forming the inner concave space of the plastic part (50).

4. A die retraction structure for forming internal threads of plastic parts according to claim 3, wherein the angle of the inclined included angle formed by the inclined slide rail (33) of the sector-shaped split block (42) and the central axis of the wedge-shaped shovel base (21) is larger than the angle of the inclined included angle formed by the inclined slide rail (33) of the circular arc split block (41) and the central axis of the wedge-shaped shovel base (21).

5. The mold shrinking structure for forming internal threads of plastic parts according to claim 1, wherein the base assembly (10) is provided with a shrinking fixing plate (11) and a shrinking pressing plate (12), the shrinking pressing plate (12) is fixedly connected to the shrinking fixing plate (11), a translation groove (13) adapted to a bottom sliding block (32) is arranged on one side facing the shrinking fixing plate (11), and the bottom sliding block (32) is slidably connected to the shrinking fixing plate (11) and limited by the translation groove (13) of the shrinking pressing plate (12).

6. The mold shrinkage structure for forming the internal threads of the plastic parts according to claim 5, wherein the translation groove (13) is provided with a first groove (14) and a second groove (15), the first groove (14) is used for limiting the bottom sliding block (32) of the circular splicing block, and the second groove (15) is used for limiting the bottom sliding block (32) of the sector splicing block (42).

7. An injection mold characterized in that a mold retraction structure for forming an internal thread of a molded article according to any one of claims 1 to 6 is provided therein, thereby performing an injection molding operation on the internal thread of an injection molded product.