CN116175905A

CN116175905A - Gas-assisted demoulding structure

Info

Publication number: CN116175905A
Application number: CN202310097315.1A
Authority: CN
Inventors: 虞伟炳; 李金国; 傅建华; 姚震
Original assignee: Zhejiang Saihao Industrial Co ltd
Current assignee: Zhejiang Saihao Industrial Co ltd
Priority date: 2023-01-20
Filing date: 2023-01-20
Publication date: 2023-05-30

Abstract

The invention provides a gas-assisted demolding structure, and belongs to the technical field of machinery. It has solved the problem of current automobile tail lamp shade drawing of patterns difficulty. This gaseous supplementary drawing of patterns structure sets up in mould department, the mould includes movable mould insert and fixes the retro-reflector insert on the movable mould insert, and movable mould insert one side has concave spread groove, the retro-reflector insert is fixed in the spread groove, gaseous supplementary drawing of patterns structure include the retro-reflector insert the outside with the annular clearance of giving vent to anger that forms between the lateral wall of spread groove and set up in the air vent in the movable mould insert, the export of air vent set up to the bottom of spread groove, just the air vent with the clearance of giving vent to anger is linked together. The gas-assisted demoulding structure has the advantage of convenience in demoulding.

Description

Gas-assisted demoulding structure

Technical Field

The invention belongs to the technical field of machinery, and relates to a gas-assisted demoulding structure, in particular to a gas-assisted demoulding structure applied to a back reflector of a tail lamp face mask.

Background

Plastic products are often manufactured by injection molding. During injection molding, a cavity is formed by combining the movable die and the fixed die in opposite directions, and the cavity is filled with a material to complete injection molding. After injection molding is completed, the finished product is ejected out by using the ejector rod to realize demolding. However, for some parts with complex surface structures, quick demolding is difficult to achieve by only relying on the existing ejection systems such as ejector blocks and ejector rods.

For this reason, an injection mold with a pneumatic and mechanical combined ejection mechanism was designed, and chinese patent was filed, whose application number was: 201720244677.9; the bulletin number is: CN206536783U; the injection mold comprises a male mold core, a sliding block, a female mold core, a push rod and a pushing device for pushing the push rod to move along the mold opening direction, wherein the male mold core comprises a through hole, the push rod is arranged in the through hole, the through hole head at the top of the male mold core is a trapezoid hole head, the push rod comprises a rod head and a rod body, the rod head is a trapezoid rod head and can be attached to the trapezoid hole head of the through hole, the push rod is arranged to be capable of sliding along the mold opening direction relative to the male mold core, a clearance groove is arranged between the through hole and the rod body, an exhaust groove is formed in a position, close to the rod head, of the rod body, the clearance groove is communicated with the exhaust groove, the male mold core comprises an air inlet hole, the air inlet hole is communicated with the clearance groove, and a sealing piece is arranged between the through hole head at the bottom of the male mold core and the push rod. The injection mold can assist in demolding by injecting air into the mold, and can effectively improve the demolding rate.

However, the gas conveying channel in the ejection mechanism is arranged in the ejector rod, for products such as automobile tail lamp covers and the like, a retro-reflector is arranged on the surface of the product, the shape of the retro-reflector is an optical prism, namely, the outer side surface of the reflector is made into an effect similar to a mirror surface, the adsorption force between a smooth mirror surface and the mirror surface is large, called a suction die, so that an effect similar to vacuum or negative pressure adsorption is formed, the package die is relatively large, a die cavity is easy to suck, and according to related regulation requirements, the optical surface of the product cannot be provided with an ejection system such as the ejector rod, the ejector block and the like.

Disclosure of Invention

The invention aims at solving the problems in the prior art, and provides a gas-assisted demoulding structure which solves the problem that the existing automobile tail lamp shade is difficult to demould.

The aim of the invention can be achieved by the following technical scheme:

the utility model provides a gaseous supplementary drawing of patterns structure, sets up in mould department, the mould includes movable mould insert and fixes the retro-reflector insert on the movable mould insert, its characterized in that, movable mould insert one side has concave spread groove, the retro-reflector insert is fixed in the spread groove, gaseous supplementary drawing of patterns structure include the outside of retro-reflector insert with the annular clearance of giving vent to anger that forms between the lateral wall of spread groove and set up in the air vent in the movable mould insert, the export of air vent set up to the bottom of spread groove, just the air vent with the clearance of giving vent to anger is linked together.

The movable die insert and the retro-reflector insert in the die are part of the movable die, one side of the movable die insert with a connecting groove is used for matching with the static die to form most of the appearance of the automobile tail lamp shade, and the retro-reflector insert is independently used for matching with the static die to form a retro-reflector part, namely the movable die insert and the retro-reflector insert jointly form part of a die cavity. The gas-assisted demolding structure cannot be used independently, is usually matched with the existing ejection structures such as a top plate and an ejector rod, and is used for acting on the position of a non-retro-reflector, namely the position of the ejection structure is staggered with the position of the retro-reflector insert, and the gas-assisted demolding structure is arranged at the position of the retro-reflector insert and staggered with the position of the existing ejection structure.

When the gas-assisted demolding structure is used, the gas is conveyed to the annular gas outlet gap between the retro-reflector insert and the side wall of the connecting groove through the vent hole and then conveyed to the entering cavity in the static mold direction while the ejection structure is ejected. At this moment, the gas is annular distribution and admits air, has surrounded the shaping region of whole retro-reflector, because the entering of gas has broken the similar vacuum or negative pressure absorbing state that forms between retro-reflector outside and the die cavity lateral wall for the adsorption affinity between retro-reflector part and the movable mould greatly reduced, simultaneously, through the thrust that is annular gas application of admitting air, the ejecting of auxiliary ejector pin, roof isotructure is demolded, make whole automobile tail lamp shade can demold fast completely, auxiliary drawing of patterns is effectual, the drawing of patterns is fast.

In the above-mentioned gas-assisted demoulding structure, the gas-assisted demoulding structure further comprises a concave hole and a plurality of communication holes, wherein the concave hole is formed in the reflector insert, the opening end of the concave hole is positioned at the bottom of the reflector insert and is communicated with the outlet of the vent hole, the plurality of communication holes surround the concave hole, one ends of the plurality of communication holes are communicated with the concave hole, and the other ends of the communication holes are communicated with the air outlet gap. Offer the gas delivery passageway in the retro-reflector inserts, keep the stability of connecting between retro-reflector inserts and the movable mould inserts, and then guarantee product fashioned stability, simultaneously, through the intercommunicating pore of several around the shrinkage pool seting up, the gas that will send into from the spread groove bottom shunts to the each position of annular clearance of giving vent to anger to the annular air inlet in the die cavity, destroy vacuum or negative pressure state that forms between retro-reflector and the die cavity lateral wall from each angle, reduce the adsorption affinity between the two more comprehensively, make the drawing of patterns more smooth and easy.

In the above-mentioned gas-assisted demolding structure, the concave hole is formed in the middle of the retro-reflector insert, and the distances between the concave hole and the outer side of the retro-reflector insert are approximately equal. The concave hole is formed in the center of the retro-reflector insert, so that after gas is split at the concave hole, the strokes of the gas conveyed to the positions of the gas outlet gaps are approximately the same, the synchronism and uniformity of annular gas supply are improved, and the smoothness and the integrity of demolding are further improved.

In the above-mentioned gas-assisted demoulding structure, the gas-assisted demoulding structure is still including being cubic control, set up inlet port, venthole and recessed intercommunication recess in the control, the export of inlet port and the import of venthole all communicate to the bottom of intercommunication recess, the export of venthole with the air vent is linked together, be provided with the piece of opening and close in the intercommunication recess, the piece of opening and close can remove or reverse the removal and make to remove recess opening direction in the intercommunication recess between inlet port and the venthole by switching on or by blocking. The air inlet hole and the air outlet hole are communicated to the bottom of the communicating groove, so that the opening and closing control of the opening and closing piece is facilitated.

In the above-mentioned gas-assisted demoulding structure, the gas-assisted demoulding structure further comprises a linkage piece which is fixed with the ejection structure and can move synchronously with the ejection structure, wherein the outer end of the opening and closing piece extends out of the communication groove and is propped against or connected with the linkage piece, and the opening and closing piece can move synchronously with the linkage piece. The opening and closing piece can synchronously act along with the ejection structure through the linkage piece, so that gas conveying can be synchronously carried out with ejection of the ejection structure, and the gas auxiliary demolding structure can keep the optimal auxiliary demolding effect.

In the above-mentioned gas-assisted demoulding structure, the one end that opens and close the piece towards the intercommunication recess bottom surface has concave spring hole, be provided with the elastic component in the spring hole, the both ends of elastic component are respectively with the bottom surface in spring hole and the bottom surface in intercommunication recess support and lean on, open and close the piece with the linkage is split structure just the outer end of opening and close the piece supports under the elasticity effect of elastic component and leans on the linkage. The opening and closing piece is tightly pressed on the linkage piece by means of the elasticity of the elastic piece, so that the communication between the opening and closing piece and the linkage piece can be ensured, the opening and closing piece and the linkage piece are relatively independent, and the installation is convenient.

In the above gas-assisted demolding structure, the side walls of the end, far away from the vent holes, of the vent gap are each provided with a guide portion inclined toward the retro-reflector insert. When the air outlet gap is used for air outlet, the air outlet of the annular air outlet gap is conveyed to the direction of the retro-reflector through the guide of the guide part, so that the vacuum adsorption state can be more comprehensively destroyed, and the demoulding is assisted.

In another aspect, in the above gas-assisted demolding structure, the bottom surface of the connecting groove is provided with a plurality of concave elongated gas distribution grooves, the plurality of gas distribution grooves are arranged around the outlet of the vent hole, one ends of the plurality of gas distribution grooves are all communicated with the vent hole, the other ends of the plurality of gas distribution grooves are all communicated with the gas outlet gap, a gas distribution block is fixed on the movable mold insert at the outlet of the vent hole, one end of the gas distribution block extends into the outlet of the vent hole, the outer side surface of the end of the gas distribution block is a conical surface, the diameter of the conical surface gradually increases from the inlet of the vent hole to the outlet, the outer side of the other end of the gas distribution block is provided with a convex annular gas guide part, the end surface of the gas guide part facing the conical surface is an arc surface, the position of the arc surface away from the center of the gas distribution groove corresponds to the position of the gas distribution groove, and the aperture of the vent hole gradually decreases from the inlet to the outlet direction. The pore diameter of the vent hole is gradually reduced, so that the air pressure of the conveying gas can be continuously enhanced, the condition of insufficient air pressure when the gas is conveyed to the cavity is prevented, and the gas can be better split and guided through the gas splitting block with the conical surface and the circular arc surface, the smoothness of the gas conveying is ensured, the air pressure loss is reduced, and the stability and the effectiveness of auxiliary demoulding are further ensured; and the gas is conveyed through the plurality of gas distribution grooves recessed in the bottom of the connecting groove, so that the support of the movable die insert on the retro-reflector insert and the strength of the retro-reflector insert can be ensured.

As another aspect, in the above-mentioned gas-assisted demolding structure, the side portion of the linkage member corresponding to the position of the opening and closing member is provided with a recessed locking notch, the cross section of the opening of the locking notch is square, the cross section of the inner end of the locking notch is circular, the diameter of the circular cross section is larger than the width of the opening of the locking notch, the opening and closing member is cylindrical, the outer end of the opening and closing member is provided with a locking portion, the outer side of the locking portion protrudes out of the outer side of the other positions of the outer end of the opening and closing member, the cross section shape and the size of the locking portion are matched with those of the opening of the locking notch, and a rod-shaped handle is connected with the position adjacent to the outer end of the opening and closing member along radial threads. When the locking device is used, the locking part of the opening and closing part is inserted into the locking notch correspondingly to the position and the angle of the locking notch, the locking part penetrates through the opening of the locking notch and stretches into the inner end of the locking notch, the handle is pulled, the opening and closing part and the locking part rotate to the position where the opening angle of the locking part and the opening angle of the locking notch are staggered, the opening and closing part is locked on the linkage part and can synchronously reciprocate along with the linkage part, the condition that elastic part is elastic fatigue is not worried about when the elastic part is used for a long time, during installation, the locking and closing part is detached from the linkage part by reverse operation, the locking and opening part and the locking part can be independently produced and installed, the installation is convenient, and the handle in threaded connection can be detached, and the production and the installation are convenient.

Compared with the prior art, the gas auxiliary demoulding structure destroys the adsorption state of the retro-reflector and the movable mould through the gas which is in annular air inlet, and the ejector rod, the top plate and other structures are assisted to eject through the thrust exerted by the gas, so that the whole automobile tail lamp shade can be rapidly and completely demoulded, the demoulding effect is good, and the demoulding speed is high.

Drawings

Fig. 1 is a schematic view of a first embodiment of the gas-assisted stripping structure.

Fig. 2 is a schematic cross-sectional view of a first embodiment of the present gas-assisted stripping structure.

Fig. 3 is a schematic cross-sectional view of the control member of the first embodiment of the gas-assist stripping structure.

Fig. 4 is an enlarged view of a portion of the vent gap in a first embodiment of the present gas-assisted stripping structure.

In the figure, 1, a movable die insert; 11. a connecting groove; 12. a vent hole; 2. a retro-reflector insert; 21. concave holes; 22. a communication hole; 3. an air outlet gap; 4. an ejection structure; 41. a top plate; 42. a push rod; 5. a control member; 51. an air inlet hole; 52. an air outlet hole; 53. a communication groove; 6. an opening and closing member; 61. a spring hole; 7. a linkage member; 8. an elastic member; 9. a bottom plate; 10. a flow controller; 101. a pressure gauge; 102. an air inlet pipe; 103. an air outlet pipe; 104. and (5) moving the die frame.

Detailed Description

The following are specific embodiments of the present invention and the technical solutions of the present invention will be further described with reference to the accompanying drawings, but the present invention is not limited to these embodiments.

Example 1

As shown in fig. 1, the gas-assisted demolding structure is disposed at a mold, the mold comprises a movable mold and a static mold, wherein the movable mold comprises a flat plate-shaped bottom plate 9 horizontally disposed, a movable mold frame 104 fixed on the bottom plate 9, a movable mold insert 1 fixed on the movable mold frame 104, and a retro-reflector insert 2 fixed on the movable mold insert 1, and one side, far away from the movable mold frame 104, of the movable mold insert 1 and the retro-reflector insert 2 is used for forming a cavity for product molding together with the static mold. The movable mould is also provided with an ejection structure 4 comprising a top plate 41 and an ejector rod 42 for ejecting and demolding a molded product and a gas conveying structure comprising a gas inlet pipe 102, a control piece 5 in a block shape, a gas outlet pipe 103, a flow controller 10 and a pressure gauge 101.

As shown in fig. 2, one side of the movable die insert 1 is provided with a concave columnar connecting groove 11, the retro-reflector insert 2 is fixed in the connecting groove 11 through a fastener, and the bottom of the retro-reflector insert 2 is abutted against the bottom of the connecting groove 11. As shown in fig. 4, an annular air outlet gap 3 is formed between the outer side of the retro-reflector insert 2 and the side wall of the connecting groove 11. The movable die insert 1 is internally provided with a vent hole 12, the movable die frame 104 is internally provided with a connecting hole, the vent hole 12 is communicated to the pressure gauge 101 through the connecting hole, and then is communicated to an air source through the air outlet pipe 103, the control piece 5 and the air inlet pipe 102.

Wherein, the outlet of the vent hole 12 is opened to the bottom of the connecting groove 11, a concave hole 21 and a plurality of communication holes 22 are opened in the retro-reflector insert 2, the opening end of the concave hole 21 is positioned at the bottom of the retro-reflector insert 2 and is communicated with the outlet of the vent hole 12, the plurality of communication holes 22 are arranged around the concave hole 21, one ends of the plurality of communication holes 22 are communicated with the concave hole 21, and the other ends are communicated with the air outlet gap 3. In the present embodiment, the concave hole 21 is formed in the middle of the retro-reflector insert 2, and the distance between the concave hole 21 and the outer side of the retro-reflector insert 2 is approximately equal.

As shown in fig. 3, the control member 5 is provided with an air inlet hole 51, an air outlet hole 52 and a concave communication groove 53, an inlet of the air inlet hole 51 is communicated with the air inlet pipe 102, and an outlet of the air outlet hole 52 is communicated with the air outlet pipe 103. The outlet of the air inlet hole 51 and the inlet of the air outlet hole 52 are both communicated to the bottom of the communication groove 53 and are deviated from the center, and are arranged on two sides, a columnar opening and closing piece 6 is arranged in the communication groove 53, and the opening and closing piece 6 can move in the communication groove 53 towards the opening direction of the moving groove or move reversely. The outside of the opening and closing member 6 is fixed with a first sealing ring, the outside of the first sealing ring is abutted against the side wall of the communication groove 53 to form a seal, the bottom of the opening and closing member 6 is provided with a concave spring hole 61, a spring serving as an elastic member 8 is arranged in the spring hole 61, and two ends of the elastic member 8 are abutted against the bottom surface of the spring hole 61 and the bottom surface of the communication groove 53 respectively. The bottom of the opening and closing piece 6 is provided with a ring-shaped second sealing ring around the spring hole 61, and when the opening and closing piece 6 moves towards the bottom surface of the communication groove 53, the second sealing ring can lean against the bottom surface of the communication groove 53 to form a seal, and the air inlet hole 51 and the air outlet hole 52 are positioned outside the sealing ring.

The control piece 5 is fixed with the end cover that is annular in the opening part that communicates recess 53, and the outer end of headstock gear 6 passes the hole of end cover and stretches out control piece 5, and headstock gear 6 middle part has annular fender shoulder, and when headstock gear 6 moved to outer end direction, the fender shoulder can support and lean on the end cover.

The gas-assisted demolding structure further comprises a linkage piece 7 which is used for being fixed with the top plate 41 of the ejection structure 4 through a fastener, wherein the linkage piece 7 is plate-shaped or rod-shaped, the outer end of the opening and closing piece 6 is abutted against the linkage piece 7 under the elastic action of the elastic piece 8, and when the linkage piece 7 is ejected along with the top plate 41, the opening and closing piece 6 can leave the bottom surface of the communication groove 53 under the elastic action of the elastic piece 8.

After the product injection molding, the gas-assisted demolding structure starts to be used, the ejection structure 4 is ejected under the driving of the driving piece, namely the top plate 41 and the ejector rod 42 are ejected towards the direction of the movable mold insert 1, the linkage piece 7 is driven to synchronously move, and the opening and closing piece 6 is far away from the bottom surface of the communication groove 53 under the elastic action of the elastic piece 8. When the opening and closing piece 6 leaves, the air inlet hole 51 and the air outlet hole 52 are communicated through the communication groove 53, the air is conveyed to the annular air outlet gap 3 along the air inlet pipe 102, the control piece 5, the air outlet pipe 103, the connecting hole, the air vent 12, the concave hole 21 and the communication hole 22, and is conveyed into the cavity through the air outlet gap 3, so that the vacuum adsorption state between the retro-reflector and the retro-reflector insert 2 is destroyed, the adsorption force is reduced, and meanwhile, under the combined action of the air thrust and the thrust of the ejector rod 42, the product is separated from the cavity, and the demolding is realized.

Example two

The technical scheme of the present embodiment is substantially the same as that of the first embodiment, except that: instead of forming the concave hole 21 and the communication hole 22 in the retro-reflector insert 2, a plurality of concave strip-shaped air dividing grooves are formed in the bottom surface of the connecting groove 11, the air dividing grooves are arranged around the outlet of the vent hole 12, one ends of the air dividing grooves are communicated with the vent hole 12, and the other ends of the air dividing grooves are communicated with the air outlet gap 3. In order to split and flow back the gas, the movable mould insert 1 at the outlet of the vent hole 12 is fixed with a block-shaped gas splitting block, one end of the gas splitting block extends into the outlet of the vent hole 12, the outer side surface of the end of the gas splitting block is a conical surface, the diameter of the conical surface gradually increases from the inlet of the vent hole 12 to the outlet, the outer side of the other end of the gas splitting block is provided with a convex annular gas guide part, the end surface of the gas guide part, which faces the conical surface, is an arc surface, the position of the arc surface, which is far away from the center of the gas splitting block, corresponds to the position of the gas splitting groove, meanwhile, the aperture of the vent hole 12 gradually reduces from the inlet to the outlet, and the side wall, which is far away from the vent hole 12, of the gas outlet gap 3 is provided with a guide part which is inclined towards the direction of the retro-reflector insert 2.

In addition, in order to avoid the condition that the elastic piece 8 is fatigued in long-term use, offer concave fore shaft on the side portion that corresponds with the position of opening and closing piece 6 on the linkage piece 7, the opening part cross section of fore shaft is square, the cross section of fore shaft inner end department is circular and this circular diameter is greater than the width of fore shaft opening part, opening and closing piece 6 is cylindric, opening and closing piece 6 outer end tip has the lock portion, the outside protrusion of lock portion is in the lateral surface of other positions of opening and closing piece 6 outer end, and the cross section shape and the size of lock portion match with the cross section shape and the size of fore shaft opening part, the radial threaded connection in the position adjacent place of opening and closing piece 6 outer end and lock position has a handle that is the shaft-like. During the use, insert the locking part and the fore shaft position and the angle of opening and close piece 6 in the fore shaft correspondingly for the locking part passes the opening part of fore shaft and stretches into the inner of fore shaft, and the handle is pulled to circumference, makes opening and close piece 6 and locking part rotate to locking part and fore shaft opening angle stagger, then opening and close piece 6 is locked on linkage piece 7, can follow linkage piece 7 synchronous reciprocating motion, here, in order to guarantee the locking of opening and close piece 6 and linkage piece 7 axial position, the axial width of fore shaft inner cross section is the axial width of circular part slightly more than the locking part.

The specific embodiments described herein are offered by way of example only to illustrate the spirit of the invention. Those skilled in the art may make various modifications or additions to the described embodiments or substitutions thereof without departing from the spirit of the invention or exceeding the scope of the invention as defined in the accompanying claims.

Claims

1. The utility model provides a gaseous supplementary drawing of patterns structure, sets up in mould department, the mould includes movable mould insert (1) and fixes reflector insert (2) on movable mould insert (1), its characterized in that, movable mould insert (1) one side has concave spread groove (11), reflector insert (2) are fixed in spread groove (11), gaseous supplementary drawing of patterns structure include the outside of reflector insert (2) with annular play air gap (3) that form between the lateral wall of spread groove (11) and set up in vent (12) in movable mould insert (1), just vent (12) with play air gap (3) are linked together.

2. The gas-assisted demolding structure according to claim 1, further comprising a concave hole (21) and a plurality of communication holes (22) formed in the retro-reflector insert (2), wherein an opening end of the concave hole (21) is located at the bottom of the retro-reflector insert (2) and is communicated with an outlet of the vent hole (12), the plurality of communication holes (22) are formed around the concave hole (21), one ends of the plurality of communication holes (22) are communicated with the concave hole (21), and the other ends of the plurality of communication holes are communicated with the vent gap (3).

3. A gas-assisted demoulding structure according to claim 1 or 2, characterized in that the gas-assisted demoulding structure further comprises a control member (5) in a block shape, an air inlet hole (51), an air outlet hole (52) and a concave communicating groove (53) are formed in the control member (5), an outlet of the air inlet hole (51) and an inlet of the air outlet hole (52) are communicated to the bottom of the communicating groove (53), an outlet of the air outlet hole (52) is communicated with the vent hole (12), an opening and closing member (6) is arranged in the communicating groove (53), and the opening and closing member (6) can move in the direction of an opening of the moving groove in the communicating groove (53) or move reversely and enable the air inlet hole (51) and the air outlet hole (52) to be conducted or blocked.

4. A gas-assisted demoulding structure according to claim 3, characterized in that it further comprises a linkage member (7) fixed to the ejector structure (4) and capable of moving synchronously with the ejector structure (4), the outer end of the opening and closing member (6) extends out of the communication groove (53) and abuts against or is connected with the linkage member (7), and the opening and closing member (6) can move synchronously with the linkage member (7).

5. The gas-assisted demolding structure according to claim 4, wherein one end of the opening and closing member (6) facing the bottom surface of the communication groove (53) is provided with a concave spring hole (61), an elastic member (8) is arranged in the spring hole (61), two ends of the elastic member (8) are respectively abutted against the bottom surface of the spring hole (61) and the bottom surface of the communication groove (53), the opening and closing member (6) and the linkage member (7) are in a split structure, and the outer end of the opening and closing member (6) is abutted against the linkage member (7) under the action of the elasticity of the elastic member (8).

6. A gas-assisted stripping structure as claimed in claim 1 or 2, characterized in that the side walls of the outlet gap (3) at the end remote from the vent hole (12) each have a guide inclined in the direction of the retro-reflector insert (2).

7. The gas-assisted demolding structure according to claim 1, wherein the bottom surface of the connecting groove (11) is provided with a plurality of concave elongated gas dividing grooves, the plurality of gas dividing grooves are arranged around the outlet of the vent hole (12), one ends of the plurality of gas dividing grooves are communicated with the vent hole (12), the other ends of the plurality of gas dividing grooves are communicated with the gas outlet gap (3), a gas dividing block is fixed on the movable mold insert (1) at the outlet of the vent hole (12), one end of the gas dividing block extends into the outlet of the vent hole (12), the outer side surface of the end of the gas dividing block is a conical surface, the diameter of the conical surface gradually increases from the inlet of the vent hole (12) to the outlet, the outer side of the other end of the gas dividing block is provided with a convex annular gas guide part, the end surface of the gas guide part facing the conical surface is a circular arc surface, the position of the circular arc surface away from the center of the gas dividing block corresponds to the position of the gas dividing groove, and the diameter of the vent hole (12) gradually decreases from the outlet direction to the inlet.

8. The gas-assisted demolding structure according to claim 4, wherein the side part of the linkage member (7) corresponding to the position of the opening and closing member (6) is provided with a concave locking opening, the cross section of the opening of the locking opening is square, the cross section of the inner end of the locking opening is round, the diameter of the round is larger than the width of the opening of the locking opening, the opening and closing member (6) is cylindrical, the end part of the outer end of the opening and closing member (6) is provided with a locking part, the outer side of the locking part protrudes out of the outer side of the other positions of the outer end of the opening and closing member (6), the cross section shape and the size of the locking part are matched with those of the opening of the locking opening, and a rod-shaped handle is connected with the position of the outer end of the opening and the locking part along radial threads.