Vacuum extraction structure of a mold

Abstract

The application provides a vacuum extraction structure of a mold and belongs to the technical field of molds. The vacuum extraction structure of the mold solves the problem of poor vacuum extraction effect of the existing mold on the molded parts formed by multiple molding. The vacuum extraction structure of the mold comprises a fixed mold, a movable mold, a hot nozzle sleeve arranged in the fixed mold, and a gate valve needle assembly partially arranged in the hot nozzle sleeve. The fixed mold and the movable mold form a cavity after being closed. The vacuum extraction structure comprises an air extraction channel arranged on the hot nozzle sleeve and an exhaust channel arranged on the fixed mold and connected with the air extraction channel. The hot nozzle sleeve has a support wall arranged horizontally and abutting against the fixed mold. An air gap is formed between the outer bottom wall of the hot nozzle sleeve and the fixed mold. A sealing element is arranged on the support wall and abuts against the fixed mold and is located outside the air gap. The gate valve needle assembly comprises a gate valve needle. The vacuum extraction structure of the mold realizes convenient and stable vacuum extraction and improves the vacuum extraction effect of the mold that needs multiple injection molding.

Description

Technical Field

[0001] The invention belongs to the technical field of molds and relates to a vacuum pumping structure of a mold. Background Art

[0002] During the injection molding process of the mold, there must be a certain amount of gas in the cavity after the mold is closed. During the injection molding process, the air in the cavity can be discharged from the exhaust groove or exhaust hole. However, for rapid injection molding or molded parts that require multiple injections, the cooled injection molding material will block the exhaust groove and exhaust hole. At this time, the air in the cavity is not completely discharged, which will cause pores, bubbles and other phenomena in the molded parts, thereby affecting the qualified rate of the molded parts.

[0003] In response to the above-mentioned problems, people have developed various vacuum pumping structures for molds: for example, the Chinese patent application [Authorization Announcement No.: CN211251199U] discloses an in-mold vacuum pumping device for a multi-cavity thin-walled plastic part injection mold, comprising an upper mold and a lower mold, an upper mold core is provided on the upper mold, and a lower mold core is provided on the lower mold. After the upper mold and the lower mold are closed, the upper mold core and the lower mold core form a cavity for molding the workpiece, and the cavity is also connected to a gas suction device, which is used to extract trapped air inside the cavity. An injection port is also provided on the upper mold, and the injection port is connected to the cavity. The gas suction device includes an air flow channel arranged in the upper mold and / or the lower mold, and an exhaust groove arranged on the corresponding parting surface of the upper film and / or the lower mold, the input end of the exhaust groove is connected to the output end of the air flow channel, the output end of the exhaust groove is connected to the cavity, and the input end of the air flow channel is connected to a vacuum pumping device.

[0004] The above structure requires that an air flow channel be provided on the upper mold and / or the lower mold, and an exhaust groove be provided on the parting surface. The air flow channel is connected to the vacuum extraction device through the exhaust groove, thereby realizing vacuum extraction of the mold cavity. However, some molded parts, such as two-color plastic parts, require two injection moldings. Therefore, during the first injection molding, the air in the mold cavity can be discharged through the air flow channel and the exhaust groove. However, during the second injection molding, the cooled molded plastic part is likely to block the input end of the air flow channel, thereby failing to realize secondary vacuum extraction of the mold cavity, resulting in poor vacuum extraction effect of the mold and affecting the molding quality of the molded part. Summary of the Invention

[0005] The purpose of the present invention is to address the above-mentioned problems in the existing technology and propose a vacuum pumping structure for the mold. The technical problem to be solved by the present invention is: how to solve the problem that the existing mold has poor vacuum pumping effect on multiple molded parts.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A vacuum pumping structure for a mold, the mold includes a fixed mold, a movable mold, a hot nozzle sleeve arranged in the fixed mold and a gate valve needle assembly partially penetrated in the hot nozzle sleeve, and a cavity is formed by the fixed mold and the movable mold being closed. The vacuum pumping structure is characterized in that the vacuum pumping structure includes an exhaust channel provided on the hot nozzle sleeve and an exhaust channel provided on the fixed mold and connected to the exhaust channel, the hot nozzle sleeve has a horizontally arranged support wall that abuts against the fixed mold, and a ventilation gap is formed between the outer bottom wall of the hot nozzle sleeve and the fixed mold, the support wall is provided with a sealing member abutting against the fixed mold and located outside the ventilation gap, the gate valve needle assembly includes a gate valve needle, the gate valve needle can pass through the ventilation gap and penetrate in the cavity, and an air gap connected to the ventilation gap is formed between the gate valve needle and the fixed mold.

[0008] Working principle: After the fixed mold and the movable mold are closed, a ventilation gap will be formed between the hot nozzle sleeve and the fixed mold during assembly. An exhaust channel is directly opened on the hot nozzle sleeve and an exhaust channel is opened on the fixed mold to connect the exhaust channel with the ventilation gap. When the gate valve needle is inserted into the mold cavity, an air gap connected to the ventilation gap is formed between the gate valve needle and the fixed mold. The air in the mold cavity can be discharged from the mold through the air gap, the ventilation gap, the exhaust channel and the exhaust channel in sequence. The existing hot nozzle sleeve and the fixed mold will have a certain ventilation gap when assembled, but since the hot nozzle sleeve is embedded in the fixed mold, the ventilation gap is reduced by the assembly of the hot nozzle sleeve, resulting in the inability to exhaust the existing ventilation gap. The present application provides a horizontally arranged support wall on the hot nozzle sleeve and abuts against the fixed mold to ensure that the size of the ventilation gap does not change when the hot nozzle sleeve and the fixed mold are assembled. , so that the positioning between the hot nozzle sleeve and the fixed mold is achieved through the support wall, and there is no need for the cooperation between the outer bottom wall of the hot nozzle sleeve and the fixed mold, so that a larger ventilation gap can be formed between the outer bottom wall of the hot nozzle sleeve and the fixed mold to achieve multiple vacuuming of the cavity, and no other additional components are required. The hot nozzle sleeve is also an existing component in the mold for cooling the gate valve needle assembly. At the same time, compared with components such as the fixed mold, the hot nozzle sleeve is smaller as a whole. Therefore, it is more convenient to process the hot nozzle sleeve alone, thereby saving the modification cost while also achieving multiple vacuuming of the cavity. For molded parts that require multiple injection molding, it is more convenient to directly use the air gap, ventilation gap, exhaust channel and exhaust channel to achieve vacuuming, thereby achieving convenient and stable vacuuming of the cavity and improving the vacuuming effect of molds that require multiple injection molding.

[0009] In the above-mentioned vacuum structure of the mold, the outer bottom wall of the hot nozzle sleeve is provided with a sealing surface 1, and the fixed mold is provided with a sealing surface 2 parallel to the sealing surface 1. The vertical cross-sections of the sealing surface 1 and the sealing surface 2 are both inclined upward and outward. The gate valve needle can pass through the sealing surface 1 and the sealing surface 2 in sequence, and part of the above-mentioned ventilation gap is formed between the sealing surface 1 and the sealing surface 2.

[0010] By providing sealing surface one and sealing surface two, the air entering the ventilation gap through the air gap can be stably extracted, and the air in the cavity is guided to a certain extent, so that the air can enter the exhaust channel from the cavity through the ventilation gap more quickly. By setting the size of the distance between sealing surface one and sealing surface two, the ventilation gap can ensure smooth exhaust while preventing the molten injection molding material from entering the ventilation gap. Therefore, the distance between sealing surface one and sealing surface two is within the range of 0.02㎜~0.04mm, and the air gap is also within the range of 0.02㎜~0.04mm, thereby further improving the vacuuming efficiency of the mold while ensuring the stability of exhaust.

[0011] In the above-mentioned vacuum structure of the mold, the outer bottom wall of the hot nozzle sleeve is provided with a buffer surface 1 connected to the sealing surface 1, and the fixed mold is provided with a buffer surface 2 connected to the sealing surface 2. The vertical sections of the buffer surface 1 and the buffer surface 2 are both inclined upward and outward from bottom to top, and the angle between the vertical section of the buffer surface 1 and the horizontal plane is greater than the angle between the vertical section of the buffer surface 2 and the horizontal plane, and part of the above-mentioned ventilation gap is formed between the buffer surface 1 and the buffer surface 2.

[0012] The setting of the buffer surface 1 and the buffer surface 2 allows the air in the cavity to be buffered between the buffer surface 1 and the buffer surface 2 after passing through the sealing surface 1 and the sealing surface 2, and can improve the smoothness of the air extraction, thereby further improving the air extraction efficiency.

[0013] In the above-mentioned vacuum structure of the mold, the outer bottom wall of the hot nozzle sleeve has a planar yield surface 1 connected to the buffer surface 1, and the fixed mold has a yield surface 2 connected to the buffer surface 2. The yield surface 2 is an arc surface concave in the direction away from the yield surface 1, and a yield space connected to the ventilation gap is formed between the yield surface 1 and the yield surface 2.

[0014] The setting of the clearance space can enable the air in the cavity to quickly enter the clearance space and be buffered in the clearance space, avoiding a large impact on the hot nozzle sleeve, thereby further improving the exhaust efficiency.

[0015] In the above-mentioned vacuum structure of the mold, the outer bottom wall of the hot nozzle sleeve is provided with a guide surface 1, and the fixed mold is provided with a guide surface 2 which is arranged parallel to the guide surface 1 and connected to the yield surface 2. The vertical cross-sections of the guide surface 1 and the guide surface 2 are both inclined outward from bottom to top. The guide surface 1 is arranged between the yield surface 1 and the support wall. Part of the above-mentioned ventilation gap is formed between the guide surface 1 and the guide surface 2 and is connected to the exhaust channel.

[0016] The guide surface 1 and the guide surface 2 are arranged in parallel, which can guide the air in the air gap so that the air in the air gap can enter the exhaust channel quickly and in the shortest path, further improving the vacuuming efficiency of the mold.

[0017] In the above-mentioned vacuum structure of the mold, the support wall is annular, the sealing member is an annular sealing ring 1, the air outlet of the ventilation gap and the air inlet of the exhaust channel are both located in the sealing ring 1, and the air inlet of the exhaust channel is arranged on the side of the support wall close to the ventilation gap.

[0018] The shape setting of the supporting wall can better realize the positioning support of the hot nozzle sleeve, and the setting of the sealing ring can prevent the air entering the exhaust channel from the ventilation gap and flowing out from the gap between the supporting wall and the fixed mold, further improving the stability of vacuum extraction; the position setting of the air inlet of the exhaust channel can facilitate the communication between the air inlet of the exhaust channel and the ventilation gap, so that the air in the ventilation gap can be quickly introduced into the exhaust channel, further improving the vacuum extraction efficiency.

[0019] In the above-mentioned vacuum structure of the mold, an annular cooling circulation channel is provided on the outer wall of the hot nozzle sleeve, and the upper end of the outer wall of the hot nozzle sleeve protrudes outward to form an annular limit stop edge. The cooling circulation channel is located below the limit stop edge, and the limit stop edge has a horizontally arranged bottom wall and the bottom wall is abutted against the fixed mold. The air outlet of the exhaust channel is located on the outer wall of the limit stop edge, and an annular sealing ring 2 is provided on the bottom wall of the limit stop edge.

[0020] By setting the limit stop edge, the support of the entire hot nozzle sleeve is made more stable, ensuring the size of the ventilation gap, and the coordinated setting of the sealing ring 1 and the sealing ring 2 can further separate the exhaust channel from the cooling circulation channel, so that the vacuuming and cooling on the hot nozzle sleeve do not affect and interfere with each other, further improving the stability of vacuuming.

[0021] In the vacuum pumping structure of the above-mentioned mold, the exhaust channel includes a vertically arranged air channel 1 and a horizontally arranged air channel 2. The air channel 2 is connected to the side wall of the upper end of the air channel 1, the air inlet of the air channel 1 is connected to the ventilation gap, and the air outlet of the air channel 2 is connected to the air inlet of the exhaust channel.

[0022] Air duct one is connected to the side wall of the upper end of air duct two. At this time, there is a certain distance between the upper end surface of air duct two and air duct one, which can facilitate the air entering air duct two to be buffered on air duct one. At the same time, because the upper end of air duct one does not need to be aligned with air duct two, it is more convenient to process the hot nozzle sleeve, so that the processing is more convenient and it can also play a buffering role, making the air extraction more stable.

[0023] In the above-mentioned vacuum structure of the mold, the support wall is provided with an annular exhaust groove 1 that connects the ventilation gap with the airway 1, the outer wall of the limit stop edge is in contact with the fixed mold, and the outer wall of the limit stop edge is provided with an annular exhaust groove 2, and the exhaust groove 2 is connected with the outlet of the airway 2.

[0024] The setting of exhaust groove 1 and exhaust groove 2 makes it necessary to set up only one exhaust channel on the fixed mold, so that the changes to the fixed mold are relatively small, which facilitates the processing and modification of the existing mold. At the same time, the gas can be quickly extracted, thereby improving the exhaust efficiency of the mold.

[0025] In the above-mentioned vacuum structure of the mold, two annular sealing grooves are provided on the outer wall of the limit stop. The vacuum structure also includes an O-ring arranged in the sealing groove. The air channel 2 is arranged between the two sealing grooves, and the outer wall of the O-ring is in contact with the fixed mold.

[0026] The setting of the O-ring allows the gas flowing out of the second airway to flow directly into the exhaust channel instead of flowing out from the gap between the limit stop and the fixed mold. In addition, the outer wall of the O-ring fits the fixed mold, reducing the friction when the hot nozzle sleeve moves up and down, thereby making the movement of the hot nozzle sleeve smoother.

[0027] Compared with the existing technology, the vacuum structure of this mold has the following advantages:

[0028] 1. The existing hot nozzle sleeve and the fixed mold will have a certain ventilation gap when assembled. However, since the hot nozzle sleeve is embedded in the fixed mold, the ventilation gap is reduced by assembling the hot nozzle sleeve, resulting in the existing ventilation gap being unable to achieve exhaust. The present application provides a horizontal support wall on the hot nozzle sleeve and abuts against the fixed mold, thereby ensuring that the size of the ventilation gap does not change when the hot nozzle sleeve and the fixed mold are assembled, so that the positioning between the hot nozzle sleeve and the fixed mold is achieved by the support wall, and there is no need for the outer bottom wall of the hot nozzle sleeve to cooperate with the fixed mold, so that a larger ventilation gap can be formed between the outer bottom wall of the hot nozzle sleeve and the fixed mold to achieve multiple vacuuming of the cavity, thereby improving the vacuuming effect of the mold.

[0029] 2. Through the coordinated setting of sealing ring 1 and sealing ring 2, the vacuuming and cooling in the hot nozzle sleeve do not affect each other, and the setting of the limit stop and the support wall can make the vertical support of the hot nozzle sleeve more stable, ensure the size of the ventilation gap, and further improve the stability of vacuuming. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a cross-sectional view of the gate valve needle of the present invention penetrating into the mold cavity.

[0031] Figure 2 yes Figure 1 A partial enlarged view of point A in the middle.

[0032] Figure 3 yes Figure 2 A partial enlarged view of point C in the middle.

[0033] Figure 4 yes Figure 1 A partial enlarged view of point B in the middle.

[0034] Figure 5 It is a structural schematic diagram of the hot nozzle sleeve in the present invention.

[0035] In the figure, 1. fixed mold; 11. exhaust channel; 12. Sealing surface 2; 13. Guide surface 2; 14. Give way surface 2; 15. Buffer surface 2; 2. movable mold; 3. cavity; 4. hot nozzle sleeve; 41. exhaust channel; 41a. air channel 1; 41b. air channel 2; 42. support wall; 42a. seal; 42b. exhaust groove 1; 43. limit stop; 43a. sealing ring 2; 43b. sealing groove; 43c. exhaust groove 2; 44. O-ring; 45. cooling water circulation channel; 46. sealing surface 1; 47. guide surface 1; 48. give way surface 1; 49. buffer surface 1; 5. gate valve needle assembly; 51. gate valve needle; 52. hot nozzle seat; 6. ventilation gap; 8. give way space; 9. air gap. DETAILED DESCRIPTION

[0036] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0037] like Figure 1 and Figure 4 As shown, the vacuum structure of the mold includes a fixed mold 1, a movable mold 2, a hot nozzle sleeve 4 arranged in the fixed mold 1 and a gate valve needle assembly 5 partially penetrated in the hot nozzle sleeve 4, and a cavity 3 formed by the fixed mold 1 and the movable mold 2 after the mold is closed.

[0038] Specifically, if Figure 1-5 As shown, the vacuum structure includes an exhaust channel 41 provided on the hot nozzle sleeve 4 and an exhaust channel 11 provided on the fixed mold 1 and connected to the exhaust channel 41. The hot nozzle sleeve 4 has a support wall 42 which is horizontally arranged and abuts against the fixed mold 1, and a ventilation gap 6 is formed between the outer bottom wall of the hot nozzle sleeve 4 and the fixed mold 1. A sealing member 42a is provided on the support wall 42 which abuts against the fixed mold 1 and is located outside the ventilation gap 6. The injection hot nozzle assembly 5 includes a gate valve needle 51. The gate valve needle 51 can pass through the ventilation gap 6 and is arranged in the mold cavity 3, and an air gap 9 connected to the ventilation gap 6 is formed between the gate valve needle 51 and the fixed mold.

[0039] Working principle: After the fixed mold 1 and the movable mold 2 are closed, a ventilation gap 6 is formed between the hot nozzle sleeve 4 and the fixed mold 1 during assembly. By directly opening an exhaust channel 41 on the hot nozzle sleeve 4 and opening an exhaust channel 11 on the fixed mold 1, the exhaust channel 41 is connected to the ventilation gap 6. When the gate valve needle 51 is inserted into the mold cavity 3, an air gap 9 connected to the ventilation gap 6 is formed between the gate valve needle 51 and the fixed mold 1. The air in the mold cavity 3 can be discharged from the mold through the air gap 9, the ventilation gap 6, the exhaust channel 41 and the exhaust channel 11 in sequence. The existing hot nozzle sleeve 4 and the fixed mold 1 will have a certain ventilation gap 6 when assembled, but since the hot nozzle sleeve 4 is embedded in the fixed mold 1, the ventilation gap 6 is reduced by the assembly of the hot nozzle sleeve 4, resulting in the existing ventilation gap 6 being unable to be exhausted. However, the present application ensures that the hot nozzle sleeve 4 and the fixed mold 1 are not exhausted during assembly by providing a support wall 42 that is horizontally arranged and abuts against the fixed mold 1 on the hot nozzle sleeve 4. By changing the size of the ventilation gap 6, the positioning between the hot nozzle sleeve 4 and the fixed mold 1 is performed by the support wall 42, and there is no need for the outer bottom wall of the hot nozzle sleeve 4 to cooperate with the fixed mold 1, so that a larger ventilation gap 6 can be formed between the outer bottom wall of the hot nozzle sleeve 4 and the fixed mold 1 to realize multiple vacuuming of the cavity 3, and no other components need to be set up additionally. The hot nozzle sleeve 4 is also the existing component for cooling the gate valve needle assembly 5 in the mold. At the same time, compared with the fixed mold 1 and other components, the hot nozzle sleeve 4 is smaller as a whole. Therefore, it is more convenient to process the hot nozzle sleeve 4 alone, thereby saving the modification cost while also realizing multiple vacuuming of the cavity 3. For molded parts that require multiple injection molding, it is more convenient to directly use the air gap 9, the ventilation gap 6, the exhaust channel 41 and the exhaust channel 11 to realize vacuuming, thereby realizing convenient and stable vacuuming of the cavity 3, and improving the vacuuming effect of the mold that requires multiple injection molding.

[0040] like Figure 2-4As shown, the outer bottom wall of the hot nozzle sleeve 4 has a sealing surface 46, a buffer surface 49, a relief surface 48 and a guide surface 47 from bottom to top, and the fixed mold has a sealing surface 12, a buffer surface 15, a relief surface 14 and a guide surface 13 from bottom to top. The sealing surface 46 is arranged in parallel with the sealing surface 12, and the vertical sections of the sealing surface 46 and the sealing surface 12 are inclined outward from bottom to top. The gate valve needle 51 can pass through the sealing surface 46 and the sealing surface 12 in sequence, and part of the above-mentioned ventilation gap 6 is formed between the sealing surface 46 and the sealing surface 12. The vertical sections of the buffer surface 49 and the buffer surface 15 are inclined outward from bottom to top, and the angle between the vertical section of the buffer surface 49 and the horizontal plane is The angle between the vertical section of the buffer surface 15 and the horizontal plane is greater than that between the buffer surface 1 and the horizontal plane. Part of the above-mentioned ventilation gap 6 is formed between the buffer surface 1 and the buffer surface 1, 15. The give way surface 1 is a horizontally arranged plane. The give way surface 14 is an arc surface that is concave away from the give way surface 1 48. A give way space 8 connected to the ventilation gap 6 is formed between the give way surface 1 and the give way surface 14. The guide surface 1 47 and the guide surface 2 13 are arranged in parallel and the vertical section of the guide surface 1 47 and the vertical section of the guide surface 2 13 are both arranged to be inclined outward from bottom to top. The guide surface 1 47 is arranged between the give way surface 1 and the support wall 42. Part of the above-mentioned ventilation gap 6 is formed between the guide surface 1 47 and the guide surface 2 13 and is connected to the exhaust channel 41.

[0041] like Figure 2-4 As shown, the support wall 42 is annular, and the sealing member 42a is an annular sealing ring 1. The air outlet of the ventilation gap 6 and the air inlet of the exhaust channel 41 are both located in the sealing ring 1. The air inlet of the exhaust channel 41 is arranged on the side of the support wall 42 close to the ventilation gap 6. An annular cooling circulation channel 45 is provided on the outer wall of the hot nozzle sleeve 4. The gate valve needle assembly 5 includes a hot nozzle seat 52 fixedly connected to the fixed mold 1. The upper end of the outer wall of the hot nozzle sleeve 4 protrudes outward to form an annular limit stop 43. The upper end of the limit stop 43 abuts against the lower end of the hot nozzle seat 52. The cooling circulation channel 45 is located below the limit stop 43. The limit stop 43 has a horizontally arranged bottom wall and the bottom wall abuts against the fixed mold 1. The air outlet of the exhaust channel 41 is located on the outer wall of the limit stop 43. The bottom wall of the limit stop 43 is provided with an annular and elastic sealing ring 2 43a.

[0042] like Figure 4 and Figure 5 As shown, the exhaust channel 41 includes a vertically arranged air channel 1 41a and a horizontally arranged air channel 2 41b. The air channel 2 41b is connected to the side wall of the upper end of the air channel 1 41a. The air inlet of the air channel 1 41a is connected to the ventilation gap 6. The air outlet of the air channel 2 41b is connected to the air inlet of the exhaust channel 11. The diameter of the air outlet of the air channel 2 41b is smaller than the diameter of the air inlet of the exhaust channel 11.

[0043] like Figure 2-5 As shown, the support wall 42 is provided with an annular exhaust groove 42b that is connected to the ventilation gap 6, the exhaust groove 42b is located directly below the airway 41a and is connected to the airway 41a, the outer wall of the limit stop 43 is in contact with the fixed mold 1, the outer wall of the limit stop 43 is provided with an annular exhaust groove 43c, the exhaust groove 43c is connected to the air outlet of the airway 41b, the outer wall of the limit stop 43 is provided with two annular sealing grooves 43b, the vacuum structure also includes an O-ring 44 arranged in the sealing groove 43b, the airway 41b is arranged between the two sealing grooves 43b, and the outer wall of the O-ring 44 is in contact with and sealed to the fixed mold 1.

[0044] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope of the appended claims.

Claims

1. A vacuum structure of a mold, the mold comprising a fixed mold (1), a movable mold (2), a hot nozzle sleeve (4) arranged in the fixed mold (1), and an injection hot nozzle assembly (5) partially inserted into the hot nozzle sleeve (4), wherein the fixed mold (1) and the movable mold (2) are closed to form a cavity (3), characterized in that: The vacuum structure comprises an exhaust channel (41) provided on the nozzle sleeve (4) and an exhaust channel (11) provided on the fixed mold (1) and connected to the exhaust channel (41); the nozzle sleeve (4) is provided with a support wall (42) which is horizontally arranged and abuts against the fixed mold (1); a ventilation gap (6) is formed between the outer bottom wall of the nozzle sleeve (4) and the fixed mold (1); a sealing member (42a) is provided on the support wall (42) abuts against the fixed mold (1) and is located outside the ventilation gap (6); the injection nozzle assembly (5) comprises a gate valve needle (51); the gate valve needle (51) can pass through the ventilation gap (6) and is arranged in the mold cavity (3); and a gas gap (9) which is connected to the ventilation gap (6) is formed between the gate valve needle (51) and the fixed mold.

2. The vacuum structure of the mold according to claim 1, characterized in that: The outer bottom wall of the hot nozzle sleeve (4) is provided with a sealing surface 1 (46), and the fixed mold (1) is provided with a sealing surface 2 (12) parallel to the sealing surface 1 (46). The vertical cross-sections of the sealing surface 1 (46) and the sealing surface 2 (12) are both inclined upward and outward from bottom to top. The gate valve needle (51) can pass through the sealing surface 1 (46) and the sealing surface 2 (12) in sequence, and a part of the above-mentioned ventilation gap (6) is formed between the sealing surface 1 (46) and the sealing surface 2 (12).

3. The vacuum structure of the mold according to claim 2, characterized in that: The outer bottom wall of the hot nozzle sleeve (4) is provided with a buffer surface 1 (49) connected to the sealing surface 1 (46), and the fixed mold (1) is provided with a buffer surface 2 (15) connected to the sealing surface 2 (12). The vertical sections of the buffer surface 1 (49) and the buffer surface 2 (15) are both inclined upward and outward from bottom to top, and the angle between the vertical section of the buffer surface 1 (49) and the horizontal plane is greater than the angle between the vertical section of the buffer surface 2 (15) and the horizontal plane. Part of the above-mentioned ventilation gap (6) is formed between the buffer surface 1 (49) and the buffer surface 2 (15).

4. The vacuuming structure of the mold according to claim 3, characterized in that: The outer bottom wall of the hot nozzle sleeve (4) has a first yielding surface (48) which is flat and connected to the first buffer surface (49), and the fixed mold (1) has a second yielding surface (14) which is connected to the second buffer surface (15). The second yielding surface (14) is an arc surface which is concave in a direction away from the first yielding surface (48), and a yielding space (8) which is connected to the ventilation gap (6) is formed between the first yielding surface (48) and the second yielding surface (14).

5. The vacuuming structure of the mold according to claim 4, characterized in that: The outer bottom wall of the hot nozzle sleeve (4) is provided with a guide surface 1 (47), and the fixed mold (1) is provided with a guide surface 2 (13) arranged parallel to the guide surface 1 (47) and connected to the yield surface 2 (14). The vertical cross-sections of the guide surface 1 (47) and the vertical cross-sections of the guide surface 2 (13) are both arranged to be inclined outward from bottom to top. The guide surface 1 (47) is arranged between the yield surface 1 (48) and the support wall (42). Part of the above-mentioned ventilation gap (6) is formed between the guide surface 1 (47) and the guide surface 2 (13) and is connected to the exhaust channel (41).

6. The vacuuming structure of the mold according to any one of claims 1 to 5, characterized in that: The supporting wall (42) is annular, the sealing member (42a) is an annular sealing ring 1, the air outlet of the ventilation gap (6) and the air inlet of the air extraction channel (41) are both located in the sealing ring 1, and the air inlet of the air extraction channel (41) is provided on a side of the supporting wall (42) close to the ventilation gap (6).

7. The vacuuming structure of the mold according to any one of claims 1 to 5, characterized in that: An annular cooling circulation channel (45) is provided on the outer wall of the hot nozzle sleeve (4), and the upper end of the outer wall of the hot nozzle sleeve (4) protrudes outward to form an annular limit stop edge (43). The cooling circulation channel (45) is located below the limit stop edge (43), and the limit stop edge (43) has a horizontally arranged bottom wall and the bottom wall is in contact with the fixed mold (1). The air outlet of the exhaust channel (41) is located on the outer wall of the limit stop edge (43), and an annular sealing ring 2 (43a) is provided on the bottom wall of the limit stop edge (43).

8. The vacuuming structure of the mold according to claim 7, characterized in that: The air extraction channel (41) includes a vertically arranged air channel 1 (41a) and a horizontally arranged air channel 2 (41b), wherein the air channel 2 (41b) is connected to the side wall of the upper end of the air channel 1 (41a), the air inlet of the air channel 1 (41a) is connected to the ventilation gap (6), and the air outlet of the air channel 2 (41b) is connected to the air inlet of the exhaust channel (11).

9. The vacuuming structure of the mold according to claim 8, characterized in that: The support wall (42) is provided with an annular exhaust groove (42b) that connects the ventilation gap (6) with the air channel (41a). The outer wall of the limit stop (43) is in contact with the fixed mold (1). The outer wall of the limit stop (43) is provided with an annular exhaust groove (43c). The exhaust groove (43c) is connected with the air outlet of the air channel (41b).

10. The vacuuming structure of the mold according to claim 9, characterized in that: Two annular sealing grooves (43b) are provided on the outer side wall of the limit stop (43); the vacuum pumping structure further comprises an O-ring (44) arranged in the sealing groove (43b); the air channel 2 (41b) is arranged between the two sealing grooves (43b); the outer side wall of the O-ring (44) is in contact with and sealed against the fixed mold (1).

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