In-mold gas high-pressure maintaining device

Abstract

The utility model provides an in-mold gas high-pressure maintaining device which comprises a sealing connection assembly, a guide assembly, a power assembly and a high-pressure gas supply assembly, and the sealing connection assembly comprises a sliding seat and a sealing column fixedly installed at the front end of the sliding seat; the guide assembly comprises guide blocks installed on the two sides of the sliding base in a matched mode. The power assembly is used for driving the sliding seat to linearly reciprocate along the guide block; the high-pressure gas supply assembly comprises a gas supply channel arranged in the sliding seat and the sealing column, one end of the gas supply channel communicates with a high-pressure gas generator, and the other end of the gas supply channel extends out of the front end of the sealing column. The sealing column and the end opening of the aluminum pipe are connected in a sleeved mode to form extrusion to achieve the sealing effect, then the high-pressure gas generator injects high-pressure gas into the aluminum pipe through the gas supply channel in the sealing column, continuous high pressure in the aluminum pipe is kept, the injection molding pressure inside and outside the aluminum pipe is balanced, and the aluminum pipe is prevented from being broken through in the injection molding process. And as the gas is simply and cleanly obtained, clean, intelligent, automatic and efficient production can be realized.

Description

Technical Field

[0001] The utility model relates to the technical field of high-pressure injection molding, in particular to a device for maintaining high pressure inside an aluminum tube in an injection mold during nested injection molding of the aluminum tube. Background Art

[0002] During the nested injection molding process on the outside of a thin-walled aluminum tube, the aluminum tube is easily broken under the injection high pressure, resulting in injection failure. At present, in order to address the above problem, thicker-walled aluminum tubes are generally used or high-pressure liquid is injected into the aluminum tube for expansion to balance the injection pressure inside and outside the aluminum tube and avoid the aluminum tube being broken during injection molding; however, the use of thicker-walled aluminum tubes will increase the unit cost and have a certain scrap rate. The equipment for expansion by injecting high-pressure liquid into the aluminum tube is expensive and requires customized high-pressure liquid equipment. At the same time, liquid leakage will cause environmental pollution around the machine, and waste liquid treatment is more troublesome and not environmentally friendly. Utility Model Content

[0003] In order to solve the problems mentioned in the above background technology, the utility model provides a device for maintaining high gas pressure inside the aluminum tube of the injection mold during nested injection molding of aluminum tubes. By injecting high-pressure gas into the aluminum tube, continuous high pressure is maintained in the tube, which is used to balance the injection pressure inside and outside the aluminum tube, avoid the aluminum tube from being broken during injection molding, and complete the injection molding synchronously.

[0004] The utility model adopts the following technical scheme: a device for maintaining high pressure gas in a mold, comprising:

[0005] The sealing connection assembly includes a sliding seat and a sealing column fixedly installed at the front end of the sliding seat, and the sealing column is used for sealingly sleeved with the port of the aluminum tube;

[0006] A guide assembly, comprising guide blocks matched and mounted on both sides of the sliding seat;

[0007] A power assembly, used for driving the sliding seat to reciprocate linearly along the guide block;

[0008] The high-pressure gas supply assembly includes a gas supply channel arranged in the sliding seat and the sealing column. The gas supply channel runs through the sliding seat and the sealing column, one end of which is connected to the high-pressure gas generator and the other end extends out of the front end of the sealing column.

[0009] Furthermore, the power assembly includes a mounting seat and a hydraulic cylinder installed at the rear end of the mounting seat, the piston rod of the hydraulic cylinder passes through the mounting seat and is connected to the sliding seat, and the two guide blocks are horizontally installed at both sides of the front end of the mounting seat at a distance.

[0010] Furthermore, the sealing column includes a connecting section, a sealing section and a sleeve section which are connected in sequence, the connecting section is fixedly installed on the sliding seat, the sleeve section is columnar, and the outer surface of the sealing section is a conical surface with a preset angle, so that the front end of the sealing section is thin and the rear end is thick, and the sleeve section and the sealing section have a smooth transition.

[0011] Furthermore, the high-pressure gas supply assembly also includes a high-pressure gas pipe and a control valve arranged on the high-pressure gas pipe, one end of the high-pressure gas pipe is fixedly connected to the sliding seat, and the high-pressure gas pipe is connected to the gas supply channel, and the other end of the high-pressure gas pipe is connected to the high-pressure gas generator through a high-pressure gas joint.

[0012] Furthermore, the in-mold gas high-pressure maintaining device also includes a stroke control component, which includes a linkage rod, a linkage block and a stroke switch. One end of the linkage rod is fixedly connected to the sliding seat, and the linkage block is fixedly arranged at the other end of the linkage rod. The two stroke switches are respectively located at the corresponding positions of the front end and the rear end of the linear reciprocating motion of the linkage block.

[0013] Furthermore, the in-mold gas high-pressure maintaining device also includes a positioning component for positioning the sliding seat when the sliding seat moves to the frontmost position, the positioning component includes a connecting block and a positioning pin, a T-shaped connecting groove is provided on the sliding seat, the connecting block is T-shaped and is installed in the connecting groove, the piston rod is fixedly connected to the connecting block, the two positioning pins are horizontally symmetrically installed through a through hole opened on the sliding seat, the through hole is connected to the connecting groove, and an idle stroke is reserved between the connecting block and the connecting groove. When the piston rod drives the connecting block to move in this idle stroke in the connecting groove, the positioning pin can telescopically move along the through hole, and when the sliding seat moves to the frontmost position, a positioning hole is opened at the guide block position corresponding to the positioning pin, and the positioning hole can be matched with the positioning pin for insertion and positioning.

[0014] Furthermore, the length of the positioning pin is greater than the depth of the through hole, and both ends of the positioning pin are conical ends, the positioning hole is a conical hole, and the length of the idle stroke is less than the outer diameter of the positioning pin.

[0015] Furthermore, an injection mold comprises the in-mold gas high-pressure maintaining device integrated inside the injection mold, and two of the in-mold gas high-pressure maintaining devices are used to seal the two ports of the sleeved aluminum tube and inject high-pressure gas into the aluminum tube.

[0016] The in-mold gas high-pressure maintaining device in the utility model can be directly integrated inside the injection mold to play the two functions of aluminum tube positioning and sealing expansion. The sealing effect is achieved by extrusion after the sealing column and the aluminum tube port are sleeved. Then, the high-pressure gas generator injects high-pressure gas into the aluminum tube through the gas supply channel on the sealing column to maintain continuous high pressure in the aluminum tube, which is used to balance the injection pressure inside and outside the aluminum tube to avoid the aluminum tube being broken during injection. After the injection is completed, the high-pressure gas in the aluminum tube is depressurized and the sleeve of the sealing column and the aluminum tube port is separated, thereby achieving an injection cycle. Since the gas is obtained simply and cleanly, clean, intelligent, automated and efficient production can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Attached Figure 1 It is a three-dimensional structural schematic diagram of the in-mold gas high pressure maintaining device of the utility model.

[0018] Attached Figure 2 It is a top view structure and a partial cross-sectional schematic diagram of the in-mold gas high pressure maintaining device of the utility model.

[0019] Attached Figure 3 This utility model is attached Figure 2 Schematic diagram of the enlarged structure of part A.

[0020] Attached Figure 4 It is a schematic diagram of the position change of the positioning pin 11 when the piston rod 101 drives the connecting block 10 and the sliding seat 4 to move in the utility model.

[0021] Attached Figure 5 It is a side structural schematic diagram and a partial enlarged schematic diagram of the in-mold gas high-pressure maintaining device of the utility model.

[0022] Attached Figure 6 It is a schematic diagram of two in-mold gas high pressure maintaining devices in the utility model, which are respectively sealed and sleeved on two ends of an aluminum tube.

[0023] Attached Figure 7 It is a schematic diagram of two in-mold gas high-pressure maintaining devices in the utility model being integrated on an injection mold and sealedly sleeved with two ends of an aluminum tube.

[0024] The description of the accompanying drawings is as follows: hydraulic cylinder 1, piston rod 101, mounting seat 2, guide block 3, positioning hole 301, sliding seat 4, connecting groove 401, through hole 402, sealing column 5, air supply channel 501, connecting section 502, sealing section 503, socket section 504, high-pressure air pipe 6, linkage rod 7, linkage block 8, travel switch 9, connecting block 10, positioning pin 11. DETAILED DESCRIPTION

[0025] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. The content of the utility model is further described below in conjunction with the drawings:

[0026] Example 1

[0027] Refer to the instruction manual Figure 1 , 2 , a device for maintaining high pressure of in-mold gas, comprising: a hydraulic cylinder 1, a mounting seat 2, a guide block 3, a sliding seat 4 and a sealing column 5;

[0028] Two guide blocks 3 are installed at a distance at the front end of the mounting seat 2, the hydraulic cylinder 1 is installed at the rear end of the mounting seat 2, the piston rod 101 of the hydraulic cylinder 1 passes through the mounting seat 2 and is located between the two guide blocks 3, the sliding seat 4 is matched and installed between the two guide blocks 3, the piston rod 101 is connected to the sliding seat 4, and the piston rod 101 can drive the sliding seat 4 to reciprocate along the linear direction of the guide block 3, the sealing column 5 is installed at the front end of the sliding seat 4, and when the sealing column 5 moves to the front end position of the guide block 3, it can be sealed and sleeved with the port of the aluminum tube placed in the injection mold;

[0029] The function of the hydraulic cylinder 1 is to drive the sliding seat 4 and the sealing column 5 to reciprocate along the guide block 3 in a straight line. In this case, the hydraulic cylinder 1 can also be replaced by an electric push rod.

[0030] An air supply channel 501 is provided in the sliding seat 4 and the sealing column 5. The air supply channel 501 penetrates the sliding seat 4 and the sealing column 5, one end of which is connected to the high-pressure gas generator, and the other end extends out of the front end of the sealing column 5. After the sealing column 5 is sealed and sleeved with the port of the aluminum tube placed in the injection mold, high-pressure gas is injected into the aluminum tube through the air supply channel 501.

[0031] Specifically, the air supply channel 501 is a channel opened inside the sliding seat 4 and the sealing column 5, one end of the air supply channel 501 on the sliding seat 4 extends out of the side of the sliding seat 4, and the other end is at the connection between the sliding seat 4 and the sealing column 5, one end of the air supply channel 501 on the sealing column 5 is at the connection between the sliding seat 4 and the sealing column 5, and the other end extends out of the front end of the sealing column 5; the air supply channel 501 on the sliding seat 4 and the air supply channel 501 on the sealing column 5 are sealed and connected at the connection between the sliding seat 4 and the sealing column 5. Specifically, a sealing plug connected to the air supply channel 501 is provided on the sliding seat 4 at the connection between the sliding seat 4 and the sealing column 5, and the sealing plug on the sliding seat 4 is sealingly inserted into the air supply channel 501 on the sealing column 5 to achieve sealed connection between the air supply channel 501 on the sliding seat 4 and the air supply channel 501 on the sealing column 5.

[0032] Refer to the instruction manual Figure 5 The sealing column 5 includes a connecting section 502, a sealing section 503 and a sleeve section 504 which are connected in sequence. The connecting section 502 is fixedly installed with the sliding seat 4. The sleeve section 504 is columnar, and its outer diameter is smaller than the inner diameter of the aluminum tube, and is used to sleeve the aluminum tube. The outer surface of the sealing section 503 is a conical surface with a preset angle, and the sleeve section 504 and the sealing section 503 have a smooth transition, so that the sealing section 503 is a trumpet shape with a thin front and a thick back, and the outer diameter of the thickest part is larger than the inner diameter of the aluminum tube;

[0033] As the sealing column 5 follows the sliding seat 4 to move linearly into the aluminum tube port and gradually penetrates into the aluminum tube, it is gradually squeezed by the sealing section 503, causing the aluminum tube to be squeezed and deformed. Since the outer wall of the aluminum tube contacts the front and rear mold cores of the injection mold and restricts the outward expansion, a sealing effect is formed between the sealing column 5 and the aluminum tube port. At the same time, the sealing column 5 is made of high-strength steel to avoid surface wear due to friction during large-scale production, which would cause the seal between the sealing column 5 and the aluminum tube port to fail.

[0034] In order to facilitate the connection between the gas supply channel 501 and the high-pressure gas generator outside the injection mold, refer to the attached manual. Figure 1 , 2 A high-pressure gas pipe 6 is fixedly connected to the sliding seat 4, and the high-pressure gas pipe 6 is connected to the gas supply channel 501. The other end of the high-pressure gas pipe 6 passes through the passage hole provided on the mounting seat 2, and a high-pressure gas joint is connected to the other end of the high-pressure gas pipe 6, and the high-pressure gas joint is connected to the high-pressure gas generator outside the injection mold;

[0035] The high-pressure gas generator is specifically a nitrogen generator. The high-pressure gas injected into the aluminum tube is nitrogen. Nitrogen is easy to obtain, clean, efficient, environmentally friendly, and low-cost.

[0036] A control valve is also provided on the high-pressure gas pipe 6. Under the action of the control valve, a continuous and stable high pressure is maintained in the aluminum tube. After the injection molding is completed, the high-pressure gas in the aluminum tube is released through the control valve.

[0037] In order to ensure that the front end position and the rear end position of the sliding seat 4 and the sealing column 5 are accurate in the reciprocating linear motion along the guide block 3, so that when the sliding seat 4 moves to the front end position, the sealing column 5 is sealed with the aluminum tube end, and when the sliding seat 4 moves to the rear end position, the sealing column 5 is separated from the aluminum tube end. Figure 1 , 2 The in-mold gas high pressure maintaining device also includes a linkage rod 7, a linkage block 8 and a travel switch 9. The linkage rod 7 is parallel to the reciprocating linear motion direction of the sliding seat 4, one end of which is fixedly connected to the sliding seat 4, and the other end passes through the aisle hole provided on the mounting seat 2. The linkage block 8 is fixedly arranged at the other end of the linkage rod 7. The travel switch 9 is fixed to the rear end of the mounting seat 2 through a bracket, and is respectively located at the front end and the rear end corresponding to the linkage block 8 following the linear reciprocating motion of the sliding seat 4;

[0038] When the linkage block 8 follows the sliding seat 4 to move to the frontmost position, the linkage block 8 contacts the travel switch 9 at the front end, generating an electrical signal to feed back to the mold controller, causing the hydraulic cylinder 1 to stop working. When the injection molding is completed, the mold controller controls the hydraulic cylinder 1 to work, causing the piston rod 101 of the hydraulic cylinder 1 to retract. When the linkage block 8 follows the sliding seat 4 to move to the rearmost position, the linkage block 8 contacts the travel switch 9 at the rear end, generating an electrical signal to feed back to the mold controller, causing the hydraulic cylinder 1 to stop working, and completing an injection molding cycle. When the piston rod 101 of the hydraulic cylinder 1 drives the sliding seat 4 to the frontmost position, the hydraulic cylinder 1 stops working, and the sliding seat 4 and the sealing column 5 are prevented from retreating by the self-locking function of the hydraulic cylinder 1.

[0039] The principle of the in-mold gas high-pressure maintaining device in this embodiment is as follows: an aluminum tube is installed inside the front mold and the rear mold of the injection mold, so that the outer wall of the aluminum tube port contacts the front and rear mold cores of the injection mold, and the two in-mold gas high-pressure maintaining devices integratedly installed inside the front mold and the rear mold of the injection mold correspond to the positions of the two ports of the aluminum tube respectively. Before starting injection molding, the piston rod 101 drives the sliding seat 4 and the sealing column 5 to move along the guide block 3, so that the sealing column 5 gradually penetrates into the aluminum tube and is gradually squeezed by the sealing section 503, so that the aluminum tube port is squeezed and deformed, so that a sealing effect is formed between the sealing column 5 and the aluminum tube port, until the linkage block 8 follows the sliding seat 4 to move to the frontmost position, the linkage block 8 It contacts the travel switch 9 at the front end, generates an electrical signal to feed back to the mold controller, stops the hydraulic cylinder 1 and self-locks, injects high-pressure gas into the aluminum tube through the high-pressure gas pipe 6, maintains the high pressure in the aluminum tube under the action of the control valve, and completes the injection molding synchronously. After the injection molding is completed, the high-pressure gas in the aluminum tube is released through the control valve, and the mold controller controls the hydraulic cylinder 1 to work, retracts the piston rod 101 of the hydraulic cylinder 1, and separates the sealing column 5 from the aluminum tube port. When the linkage block 8 follows the sliding seat 4 to move to the rearmost position, the linkage block 8 contacts the travel switch 9 at the rear end, generates an electrical signal to feed back to the mold controller, stops the hydraulic cylinder 1 and completes an injection molding cycle.

[0040] Example 2

[0041] The inventor found that after the piston rod 101 drives the sliding seat 4 and the sealing column 5 to move to the front end position along the guide block 3, the hydraulic cylinder 1 stops working and relies on the self-locking function of the hydraulic cylinder 1 to prevent the sliding seat 4 and the sealing column 5 from retreating. However, since it is necessary to inject high-pressure gas into the aluminum tube, the piston rod 101 of the hydraulic cylinder 1 may retreat slightly due to the high pressure, which may cause the sealing section 503 of the sealing column 5 to separate from the aluminum tube port, causing air leakage and sealing failure, thereby affecting the injection molding effect and causing injection molding failure; therefore,

[0042] Refer to the instruction manual Figure 3 The in-mold gas high-pressure holding device also includes a positioning pin 11 for positioning the position of the sliding seat 4 when the sliding seat 4 moves to the frontmost position, a T-shaped connecting groove 401 is provided on the sliding seat 4, a T-shaped connecting block 10 is installed in the connecting groove 401, a piston rod 101 is fixedly connected to the connecting block 10, and an idle stroke is reserved between the connecting block 10 and the connecting groove 401, that is, when the piston rod 101 drives the connecting block 10 forward or backward, the connecting block 10 first moves in the idle stroke, and the sliding seat 4 is stationary. When the idle stroke is completed, the connecting block 10 conflicts with the sliding seat 4 and drives the sliding seat 4 to move;

[0043] The two positioning pins 11 are installed horizontally and symmetrically through the through holes 402 opened on the sliding seat 4, and the through holes 402 are connected with the connecting groove 401. Specifically, the positioning pin 11 is located at the front end of the connecting groove 401. When the sliding seat 4 moves to the front end position, a positioning hole 301 is opened at the position of the guide block 3 corresponding to the positioning pin 11, and the positioning hole 301 can match the positioning pin 11 for insertion and positioning;

[0044] The length of the positioning pin 11 is greater than the depth of the through hole 402 , and both ends of the positioning pin 11 are conical ends, the positioning hole 301 is a conical hole, and the length of the idle stroke is less than the outer diameter of the positioning pin 11 .

[0045] See attached Figure 4 The left figure is a schematic diagram of the piston rod 101 driving the connecting block 10 to move forward or backward, and the right figure is a schematic diagram of the piston rod 101 driving the connecting block 10 to move forward to the front end position.

[0046] When the piston rod 101 drives the connecting block 10 forward, the outer end of the positioning pin 11 is resisted by the guide block 3, so that the inner end of the positioning pin 11 extends into the connecting groove 401. At this time, the two corners at the front end of the connecting block 10 are respectively resisted by the conical surfaces of the two positioning pins 11, which pushes the sliding seat 4 forward until the sliding seat 4 moves to the front end position. At this time, the positioning pin 11 moves to the positioning hole 301 position, and the positioning pin 11 is no longer resisted by the guide block 3. At the same time, the connecting block 10 continues to move forward. Through the action of the conical surface at the inner end of the positioning pin 11, the positioning pin 11 is driven to move toward the positioning hole 301, so that the outer end of the positioning pin 11 matches the positioning hole 301 for insertion and positioning. The connecting block 10 moves to the front end position. At this time, the inner end of the positioning pin 11 resists the side of the connecting block 10, which locates the position of the sliding seat 4 and the guide block 3, and presents an attached Figure 4 In the state of the middle right figure, when subjected to the high pressure in the aluminum tube, the positioning pin 11 can prevent the sliding seat 4 from being displaced, thereby ensuring the sealing effect between the sealing column 5 and the aluminum tube port;

[0047] When the piston rod 101 drives the connecting block 10 from the attached Figure 4 When the state in the middle right figure moves backward, the connecting block 10 contacts the sliding seat 4 after completing the idle stroke, and drives the sliding seat 4 to move backward. At this time, the inner end of the positioning pin 11 no longer contacts the side of the connecting block 10. Through the action of the conical surface of the outer end of the positioning pin 11 and the conical surface of the positioning hole 301, the positioning pin 11 is driven to move toward the inside of the connecting groove 401 until the outer end of the positioning pin 11 is separated from the positioning hole 301 and contacts the guide block 3. At this time, the conical surface of the inner end of the positioning pin 11 contacts the angle of the front end of the connecting block 10, and an attachment is presented. Figure 4 The state of the middle left figure, until the sliding seat 4 moves to the rearmost position.

[0048] Example 3

[0049] An injection mold comprises a front mold, a rear mold, and an in-mold gas high-pressure maintaining device as described in Example 1 or Example 2 integrated inside the front mold and the rear mold. The two in-mold gas high-pressure maintaining devices are used to seal and sleeve on two ports of an aluminum tube and inject high-pressure gas into the aluminum tube.

[0050] The positions where the two in-mold gas high pressure holding devices are integrated and installed on the injection mold and the positions where the aluminum tube is installed on the injection mold are as shown in the attached figure. Figure 7 shown.

[0051] It should be noted that the in-mold gas high-pressure maintenance described in the name of this patent (a device for maintaining in-mold gas high pressure) refers to: injecting high-pressure gas into the aluminum tube installed in the injection mold to maintain continuous high pressure in the aluminum tube, which is used to balance the injection pressure inside and outside the aluminum tube to prevent the aluminum tube from being broken during injection molding.

[0052] Obviously, it is possible to modify and / or add components to the above-mentioned in-mold gas high pressure maintaining device and the corresponding method without departing from the field and scope of the present invention.

[0053] It is also clear that although the utility model has described the in-mold gas high-pressure maintaining device in detail, technicians in this field will certainly be able to obtain many other equivalent forms of in-mold gas high-pressure maintaining devices and corresponding methods. The in-mold gas high-pressure maintaining devices and corresponding methods have the characteristics as described in the claims, and therefore are all within the scope of the protection field defined thereby.

Claims

1. A device for maintaining high pressure of in-mold gas, characterized in that: include, The sealing connection assembly comprises a sliding seat (4) and a sealing column (5) fixedly mounted on the front end of the sliding seat (4), wherein the sealing column (5) is used for sealingly sleeved connection with the port of the aluminum tube; A guide assembly, comprising guide blocks (3) matched and mounted on both sides of the sliding seat (4); A power assembly, used for driving the sliding seat (4) to move linearly back and forth along the guide block (3); The high-pressure gas supply assembly comprises a gas supply passage (501) arranged in the sliding seat (4) and the sealing column (5). The gas supply passage (501) runs through the sliding seat (4) and the sealing column (5), one end of which is connected to the high-pressure gas generator and the other end of which extends out of the front end of the sealing column (5).

2. The in-mold gas high pressure maintaining device according to claim 1, characterized in that: The sealing column (5) comprises a connecting section (502), a sealing section (503) and a sleeve section (504) which are connected in sequence, the connecting section (502) is fixedly mounted on the sliding seat (4), the sleeve section (504) is columnar, and the outer surface of the sealing section (503) is a conical surface with a preset angle, so that the front end of the sealing section (503) is thin and the rear end is thick, and the sleeve section (504) and the sealing section (503) have a smooth transition.

3. The in-mold gas high pressure maintaining device according to claim 1, characterized in that: The power assembly comprises a mounting seat (2) and a hydraulic cylinder (1) mounted at the rear end of the mounting seat (2); a piston rod (101) of the hydraulic cylinder (1) passes through the mounting seat (2) and is connected to the sliding seat (4); and two guide blocks (3) are horizontally mounted at a distance on both sides of the front end of the mounting seat (2).

4. The in-mold gas high pressure maintaining device according to claim 1, characterized in that: The high-pressure gas supply assembly further comprises a high-pressure gas pipe (6) and a control valve arranged on the high-pressure gas pipe (6); one end of the high-pressure gas pipe (6) is fixedly connected to the sliding seat (4), and the high-pressure gas pipe (6) is connected to the gas supply channel (501); the other end of the high-pressure gas pipe (6) is connected to the high-pressure gas generator via a high-pressure gas joint.

5. The in-mold gas high pressure maintaining device according to claim 1, characterized in that: The in-mold gas high-pressure maintaining device also includes a stroke control component, which includes a linkage rod (7), a linkage block (8) and a stroke switch (9). One end of the linkage rod (7) is fixedly connected to the sliding seat (4), and the linkage block (8) is fixedly arranged at the other end of the linkage rod (7). The two stroke switches (9) are respectively located at the corresponding positions of the front end and the rear end of the linear reciprocating motion of the linkage block (8).

6. The in-mold gas high pressure maintaining device according to claim 3, characterized in that: The in-mold gas high-pressure maintaining device also includes a positioning component for positioning the sliding seat (4) when the sliding seat (4) moves to the frontmost position, the positioning component includes a connecting block (10) and a positioning pin (11), a T-shaped connecting groove (401) is provided on the sliding seat (4), the connecting block (10) is T-shaped and is installed in the connecting groove (401), the piston rod (101) is fixedly connected to the connecting block (10), and the two positioning pins (11) are installed horizontally and symmetrically through the through holes (402) provided on the sliding seat (4). The through hole (402) is connected to the connecting groove (401), and an idle stroke is reserved between the connecting block (10) and the connecting groove (401). When the piston rod (101) drives the connecting block (10) to move in the idle stroke in the connecting groove (401), the positioning pin (11) can move telescopically along the through hole (402). When the sliding seat (4) moves to the frontmost position, a positioning hole (301) is opened at the position of the guide block (3) corresponding to the positioning pin (11), and the positioning hole (301) can be matched with the positioning pin (11) for insertion and positioning.

7. The in-mold gas high pressure maintaining device according to claim 6, characterized in that: The length of the positioning pin (11) is greater than the depth of the through hole (402), both ends of the positioning pin (11) are conical ends, the positioning hole (301) is a conical hole, and the length of the idle stroke is less than the outer diameter of the positioning pin (11).

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