Precise injection mold for automobile plastic parts

Abstract

The application discloses a precise injection mold for automobile plastic parts and relates to the field of injection molds, which comprises a fixed mold, a lower cavity fixed at the top of the fixed mold, guide rods fixed at the corners of the fixed mold, a movable mold, an injection port arranged at the top of the movable mold, a bottom of the injection port, a matching gas conveying pipe, a three-way valve, a demolding mechanism, and the inside of the lower cavity and the upper cavity. The precise injection mold for automobile plastic parts is provided with a sealing mechanism, which can realize the sliding of the gasket in the frame groove. In addition, the excess gas is conveyed to the through groove in the upper cavity and the lower cavity through the matching gas conveying pipe. At this time, the demolding mechanism in the upper cavity and the through groove can realize demolding work, and further demolding treatment can be performed.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of injection molds, in particular to a precise injection mold for automobile plastic parts. BACKGROUND

[0002] In the current rapid development of the automobile industry, automobile parts are developing towards light weight, integration and high performance. Plastic parts are widely used in the fields of automobile interior and exterior parts, structural parts and functional parts due to their advantages of light weight, low cost, high design freedom and simple forming process. When the automobile plastic parts are formed, an injection mold needs to be used.

[0003] There are many types of existing automobile injection molds, but there are still some disadvantages in use. First, after the automobile plastic parts are formed, a demolding mechanism needs to be used to process the formed plastic parts, but adhesion is likely to occur during demolding. In order to overcome the above-mentioned defects, reference can be made to the existing technology (Chinese patent with application number CN201920239067.9 and application date of February 26, 2019) which discloses a demolding mechanism for automobile plastic part forming. The demolding mechanism is provided with a baffle connected through a rotating shaft at both ends of the top of the convex mold, which is convenient for shielding and blocking opening. The cylinder provided above the baffle drives the ejection plate to eject and demold, which can efficiently eject the automobile plastic part forming mold. The design is reasonable, the demolding efficiency is improved, the high-temperature-resistant sealing gasket is bonded at the bottom of the baffle, the sealing effect is good, the high-temperature-resistant performance is good, the structure is simple, and reference can be made to the existing technology (Chinese patent with application number CN201810755585.6 and application date of July 11, 2018) which discloses a flat plate injection mold for automobile. The device is provided with a support block and a receiving groove, so that the upper mold can slide on the lower mold, avoiding the need to remove the upper mold after each injection, which is time-consuming and labor-intensive. The sliding of the upper mold and the operation of the telescopic cylinder make it convenient to lift and take out the formed mold. Finally, reference can be made to the existing technology (Chinese patent with application number CN202110997441.3 and application date of August 27, 2021) which discloses an injection mold for automobile lamp production. The injection mold can limit the movement direction of the upper mold seat through the limiting column, and the injection cavity is clamped in the inside of the lower mold seat, which is convenient to disassemble in the later period. The inside of the lower mold seat and the positioning frame are designed in a separated manner, which can be fastened on one side through the locking pin, can quickly disassemble the internal structural parts of the lower mold seat, and improves the injection efficiency in the later period.

[0004] Although the existing mold device is assisted by mechanical ejection to open the mold, the plastic forming part is still in a high temperature state when demolding, especially after using polypropylene for heating injection molding, the initial temperature of the formed forming part is 90-120 degrees, the mechanical ejection mechanism is in contact with the surface of the high-temperature plastic part in an instant, stress concentration is easily generated, the stress not only leaves the appearance defects such as pin marks and scratches on the surface of the plastic part, but also may cause internal structure damage, resulting in the strength of the plastic part decreasing and the size being out of tolerance.

[0005] Therefore, the present application provides a precision injection mold for automobile plastic parts to solve the above problems. SUMMARY

[0006] The present application aims to provide a precision injection mold for automobile plastic parts to solve the above problems in the background art that the mold device on the market currently adopts mechanical ejection to assist in mold opening, but the plastic forming part is still in a high temperature state when demolding, the mechanical ejection mechanism is in contact with the surface of the high-temperature plastic part in an instant, stress concentration is easily generated, the stress not only leaves the appearance defects such as pin marks and scratches on the surface of the plastic part, but also may cause internal structure damage, resulting in the strength of the plastic part decreasing and the size being out of tolerance.

[0007] To achieve the above object, the present application provides the following technical scheme: a precision injection mold for automobile plastic parts, comprising a fixed mold and a lower cavity fixed at the top position of the fixed mold, a guide rod is fixed at the corner of the periphery of the fixed mold, and the outer side of the guide rod is slidably arranged in the inner side of the corner of the periphery of the movable mold, and an upper cavity is fixed at the lower position of the movable mold; an injection port is formed at the top position of the movable mold, and the bottom position of the injection port corresponds to the inside upper position of the lower cavity, a sealing sleeve is fixed at the outer side of the lower cavity, and the upper end inner side of the sealing sleeve corresponds to the lower end outer side of the upper cavity, a sealing mechanism is arranged in the inside of the sealing sleeve, which avoids gas leakage after the lower cavity and the upper cavity are separated, and the outer side of the two ends of the sealing sleeve is also connected to one side of the matched gas conveying pipe, and the outer end of the matched gas conveying pipe is connected with the demolding mechanism through a three-way valve, and the demolding mechanism is arranged at the inside of the two sides of the lower cavity and the upper cavity.

[0008] Preferably, the front and rear ends of the sealing sleeve are both connected with an air inlet, the outer end of the air inlet extends into the frame groove formed in the inside of the sealing sleeve, and the sealing mechanism is slidably arranged in the inside of the frame groove.

[0009] Preferably, the sealing mechanism comprises a gasket slidingly arranged inside the frame groove, and a plurality of moving tubes are fixed to the bottom of the gasket, the bottom of the moving tubes is slidingly arranged inside the fixed tube, the inner bottom of the fixed tube is fixed to the bottom of the reset spring, and the top of the reset spring is fixed to the bottom of the moving tube.

[0010] Preferably, the bottom of the fixed tube is fixed inside the frame groove, and the gasket forms a sliding structure between the moving tube and the inside of the frame groove.

[0011] Preferably, the outer side of the gasket is provided with a wear-resistant layer, and the gasket is provided with an elastic air bag on one side inside the frame groove, and the outer side of the gasket is tightly attached to the outer wall of the upper cavity.

[0012] Preferably, the demolding mechanism comprises a through groove communicated with the outer end of the gas conveying pipe, and the end of the through groove away from the gas conveying pipe is communicated with the upper end of the vertical groove, the upper end of the vertical groove is fixed to the top of the connecting spring, the bottom of the connecting spring is fixed to the top of the piston disc, the bottom of the piston disc is fixed with a moving rod, and the bottom of the moving rod is rotatably provided with four gaskets.

[0013] Preferably, the bottom surfaces of the four gaskets are combined to form a seamless cylinder, and the diameter of the seamless cylinder is consistent with the diameter of the moving rod, the top of the gasket is connected to the bottom of the moving rod through a torsion spring, and the outer side of the gasket is slidingly arranged inside the upper cavity.

[0014] Preferably, a tapered groove is formed in the inner side of the piston disc, a tapered block is arranged in the inner side of the tapered groove, the bottom of the tapered block is fixed to the top of the matching spring, the bottom of the matching spring is fixed inside the moving rod, a cavity is formed in the inner side of the moving rod, and the bottom of the cavity is connected to the gas outlet.

[0015] Preferably, the centers of the gas outlet, the tapered block and the piston disc are collinearly arranged, and the outer side of the moving rod is slidingly arranged inside the upper cavity.

[0016] Preferably, the elastic force of the matching spring is greater than that of the connecting spring, and the tapered block forms an elastic sliding structure between the inside of the matching spring and the tapered groove.

[0017] Compared with the prior art, the beneficial effects of the present application are that the automobile plastic part precision injection mold is provided with a sealing mechanism, the sealing mechanism can realize the sliding of the fitted gasket inside the sealing sleeve in the frame groove, the upper cavity can be slightly lifted to facilitate the injection of gas into the inside of the upper cavity and the lower cavity, the injection of cold and hot alternating gas can make the molded parts inside the upper cavity and the lower cavity realize preliminary demolding treatment through the principle of thermal expansion and cold contraction, and the excess gas is transported into the through groove inside the upper cavity and the through groove through the cooperating gas conveying pipe, at this time, the demolding mechanism inside the upper cavity and the through groove can realize demolding work, and the demolding process can be further carried out, and the specific content is shown as follows:

[0018] 1. The gas is conveyed into the sealing sleeve through the gas inlet, the fitted gasket inside the sealing sleeve can slide outside the fixed pipe through the moving pipe, the outside of the fitted gasket can move on the outer wall of the upper cavity and the lower cavity, the elastic air bag on one side of the fitted gasket is extruded on the outside corner of the lower cavity, the gap between the sealing sleeve, the lower cavity and the upper cavity is closed, and the leakage phenomenon can be avoided;

[0019] 2. The movable mold and the upper cavity are slightly lifted by the electric push rod, at this time, it is necessary to ensure that the conveyed gas can be conveyed into the molded part, in addition, the cold and hot alternating gas conveyed through the gas inlet realizes the preliminary demolding treatment of the molded part through the slight thermal expansion and cold contraction in the form of cold and hot alternation, further, the cooperating gas conveying pipe is provided, the cooperating gas conveying pipe realizes the operation of the demolding mechanism inside the upper cavity and the lower cavity through the gas conveying work, the fitted block is expanded through the torsional spring through the movement of the moving rod, the opening of the fitted block can increase the demolding position, and the gas demolding treatment is realized through the gas outlet. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a front view structure schematic diagram of the present application;

[0021] Figure 2 It is a side view structure schematic diagram of the present application;

[0022] Figure 3 It is a sealing sleeve top view structure schematic diagram of the present application;

[0023] Figure 4 It is an enlarged structure schematic diagram of A in the present application Figure 3

[0024] Figure 5 It is a fixed pipe front view cross-sectional structure schematic diagram of the present application;

[0025] Figure 6 It is an upper cavity front view cross-sectional structure schematic diagram of the present application; ​

[0026] Figure 7 For the present invention Figure 6 Enlarged structural diagram at point B;

[0027] Figure 8 This is a schematic diagram of the bonding block in the open state of the present invention;

[0028] Figure 9 This is a schematic diagram of the main cross-sectional structure of the movable rod of the present invention.

[0029] In the diagram: 1. Fixed mold; 2. Lower cavity; 3. Guide rod; 4. Moving mold; 5. Upper cavity; 6. Injection port; 7. Air inlet; 8. Sealing sleeve; 9. Frame groove; 10. Fitting gasket; 11. Moving tube; 12. Fixed tube; 13. Return spring; 14. Matching air supply tube; 15. Through groove; 16. Vertical groove; 17. Connecting spring; 18. Piston disc; 19. Moving rod; 20. Fitting block; 21. Conical block; 22. Conical groove; 23. Matching spring; 24. Air outlet. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Please see Figures 1-9 The present invention provides the following technical solution: a precision injection mold for automotive plastic parts.

[0032] Example 1: To facilitate preliminary demolding of the plastic molded parts after molding in the lower cavity 2 and upper cavity 5, an attachment can be provided. Figure 1 -Appendix Figure 5The utility model provides a mould, including fixed lower cavity 2 of die 1 and die 1 top position, fixed guide rod 3 is positioned at the four corners of die 1, and the outside of guide rod 3 is slidably arranged in the inside of the four corners of movable die 4, and the lower of movable die 4 is fixed with upper cavity 5, the top of movable die 4 is provided with injection port 6, and the bottom of injection port 6 is correspondingly arranged in the inside upper of lower cavity 2, the outside of lower cavity 2 is fixed with sealing sleeve 8, and the inside upper of sealing sleeve 8 is correspondingly arranged in the outside lower of upper cavity 5, the inside of sealing sleeve 8 is provided with sealing mechanism, sealing mechanism is arranged to avoid gas leakage after separating lower cavity 2 and upper cavity 5, the front and rear ends of sealing sleeve 8 are both communicated with air inlet 7, and the outside of air inlet 7 is arranged in the frame groove 9 in the inside of sealing sleeve 8, and the inside of frame groove 9 is slidably provided with sealing mechanism, sealing mechanism includes the slidingly arranged abutting gasket 10 in the inside of frame groove 9, and the bottom of abutting gasket 10 is fixed with a plurality of groups of moving pipe 11, the bottom of moving pipe 11 is slidably arranged in the inside of fixed pipe 12, and the inside bottom of fixed pipe 12 is fixed with the bottom of reset spring 13, and the top of reset spring 13 is fixed in the bottom of moving pipe 11, the bottom of fixed pipe 12 is fixed in the inside of frame groove 9, and abutting gasket 10 constitutes the sliding structure between moving pipe 11 and the inside of frame groove 9, the outside of abutting gasket 10 is wear-resistant layer, and the one side of the inside of frame groove 9 is also provided with elastic air bag, and the outside of abutting gasket 10 is closely attached to the outer wall of upper cavity 5.

[0033] Firstly, the overall mold is assembled, then the heated raw material is injected into the mold through the injection port 6, then the overall cooling treatment is carried out, and then the automobile plastic forming part can be obtained, then the starting of the electric push rod can make the movable mold 4 drive the upper cavity 5 to lift on the outside of the guide rod 3, and ensure that the lifting position is small, at this time only need to ensure that the gas can be injected, at this time the temperature of the forming part is also relatively high, at this time the inside of the sealing sleeve 8 is injected into the gas through the gas inlet 7, after the gas is injected, the sealing sleeve 8 can realize the sliding of the gasket 10 in the frame groove 9, when the gas pushes the gasket 10 to move, the gasket 10 will also move through the moving pipe 11, so that the bottom position of the moving pipe 11 slides in the inside position of the fixed pipe 12, in addition, the reset spring 13 will also be deformed, at this time the gasket 10 will move to the outer wall position of the upper cavity 5, and at this time the gasket 10 moves in the process, the elastic air bag arranged on one side of the gasket 10 will also move, so that the gasket 10 is stably attached to the outer wall of the upper cavity 5, at this time the gap between the upper cavity 5 and the lower cavity 2 is filled with cold and hot alternating gas through the gas inlet 7, by heating and cooling the formed plastic part alternately, because the plastic part has a certain toughness, at this time the hot expansion and cold contraction form is used to realize the preliminary demolding of the plastic part.

[0034] Example two: in order to solve the mold device is mostly used mechanical top open way to assist demolding, but the plastic forming part is still in high temperature state when demolding, mechanical top open mechanism and high temperature plastic part surface contact instant, stress concentration is extremely easy to produce, this kind of stress not only will leave the pin mark, scratch and other appearance defects on the surface of plastic part, also may cause internal structure damage, lead to the problem of strength decline, size out of tolerance of plastic part, can refer to the attached Figure 1 -attached Figure 3 and attached Figure 6 -attached Figure 9The outer side of the sealing sleeve 8 is connected to the side of the matching gas pipe 14, and the outer end of the matching gas pipe 14 is connected to the demolding mechanism through a three-way valve, and the demolding mechanism is arranged inside the lower cavity 2 and the upper cavity 5. The demolding mechanism comprises a through groove 15 connected to the outer end of the matching gas pipe 14, and the end of the through groove 15 away from the matching gas pipe 14 is connected to the upper end of a vertical groove 16. The inner side of the upper end of the vertical groove 16 is fixed to the top end of a connecting spring 17, and the bottom of the connecting spring 17 is fixed to the top of a piston disc 18. The bottom of the piston disc 18 is fixed with a moving rod 19, and the bottom of the moving rod 19 is rotatably provided with four sets of abutting blocks 20. The bottom surface of the four sets of abutting blocks 20 is combined into a seamless cylinder, and the diameter of the seamless cylinder is consistent with the diameter of the moving rod 19. The top of the abutting block 20 is connected to the bottom of the moving rod 19 through a torsion spring, and the outer side of the abutting block 20 is slidably arranged inside the upper cavity 5. The inner side of the piston disc 18 is provided with a tapered groove 22, and the inner side of the tapered groove 22 is provided with a tapered block 21. The bottom of the tapered block 21 is fixed to the top of a matching spring 23, and the bottom of the matching spring 23 is fixed inside the moving rod 19. The inner side of the moving rod 19 is provided with a cavity, and the bottom of the cavity is connected to the gas outlet 24. The centers of the gas outlet 24, the tapered block 21 and the piston disc 18 are collinearly arranged, and the outer side of the moving rod 19 is slidably arranged inside the upper cavity 5. The elastic force of the matching spring 23 is greater than that of the connecting spring 17, and the tapered block 21 and the inner side of the tapered groove 22 form an elastic sliding structure through the matching spring 23.

[0035] When the gas fills the gap between the lower cavity 2 and the upper cavity 5, the gas will be transported through the matched gas pipe 14. Since the upper and lower ends of the matched gas pipe 14 are connected to one side of the upper cavity 5 and the lower cavity 2 respectively, the gas can be transported to the inside of the through groove 15 through the matched gas pipe 14. At this time, the gas also flows into the upper end of the vertical groove 16. At this time, the piston disc 18 will move vertically in the vertical groove 16, so that the return spring 13 is deformed. When the piston disc 18 moves in the vertical groove 16, it also drives the moving rod 19 to move, so that the moving rod 19 drives the abutting block 20 to move to the outside of the upper cavity 5. Since the top of the abutting block 20 is rotatably arranged at the bottom of the moving rod 19 by the torsion spring, at this time the abutting block 20 is not limited by the slot of the upper cavity 5, so that the abutting block 20 is rotated. At this time, the tapered block 21 is moved, and the force bearing area of the automobile plastic part is increased by the arrangement of the abutting block 20. When the tapered block 21 moves to the appropriate position, it will directly act on the top of the piston disc 18, so that the tapered block 21 moves in the tapered groove 22, and the tapered groove 22 moves by the matched spring 23. At this time, the gas will enter the cavity in the moving rod 19. At this time, the gas will be jetted through the gas outlet 24, so that the automobile plastic part after molding can be demolded again by the jetting of the gas outlet 24 and the matched arrangement of the abutting block 20. Through the above arrangement, the demolding process can be facilitated, and the demolding efficiency can be improved.

[0036] Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can modify the technical solutions described in the foregoing embodiments, or make equivalent replacements to some of the technical features, as long as they are within the spirit and principles of the present application. Any modification, equivalent replacement, improvement, etc. made within the scope of the present application shall be included in the protection scope of the present application.

Claims

1. An automobile plastic part precision injection mold, comprising a fixed mold (1) and a lower cavity (2) fixed at the top of the fixed mold (1), a guide rod (3) is fixed at the corner of the periphery of the fixed mold (1), and the outer side of the guide rod (3) is slidably arranged inside the corner of the periphery of the movable mold (4), and an upper cavity (5) is fixed at the lower side of the movable mold (4); characterized in that An injection port (6) is arranged at the top of the movable mold (4), and the bottom of the injection port (6) is arranged above the inside of the lower cavity (2), a sealing sleeve (8) is fixed at the outer side of the lower cavity (2), and the upper end of the sealing sleeve (8) is arranged on the outer side of the lower end of the upper cavity (5), a sealing mechanism is arranged in the sealing sleeve (8), which can prevent gas leakage after the lower cavity (2) and the upper cavity (5) are separated, and the outer ends of the sealing sleeve (8) are connected to one side of the matched gas conveying pipe (14), and the outer ends of the matched gas conveying pipe (14) are connected to the demolding mechanism through a three-way valve, and the demolding mechanism is arranged on the inside of the lower cavity (2) and the upper cavity (5) on both sides; The sealing mechanism comprises a matching gasket (10) slidably arranged at the inner side of the frame groove (9), and a plurality of groups of moving pipes (11) are fixed at the bottom of the matching gasket (10), the moving pipes (11) are slidably arranged in the inside of the fixed pipe (12), and the inner bottom of the fixed pipe (12) is fixed with the bottom of the reset spring (13), and the top of the reset spring (13) is fixed at the bottom of the moving pipe (11); The demolding mechanism comprises a through groove (15) connected to the outer end of the matched gas conveying pipe (14), and one end of the through groove (15) away from the matched gas conveying pipe (14) is connected to the upper end of the vertical groove (16), the upper end of the vertical groove (16) is fixed at the top of the connecting spring (17), and the bottom of the connecting spring (17) is fixed at the top of the piston disc (18), the bottom of the piston disc (18) is fixed with a moving rod (19), and four groups of matching blocks (20) are rotatably arranged at the bottom of the moving rod (19); The bottom of the fixed pipe (12) is fixed in the inside of the frame groove (9), and the inside of the frame groove (9) is slidably arranged between the moving pipe (11) and the frame groove (9); The outer side of the matching gasket (10) is provided with a wear-resistant layer, and an elastic air bag is further arranged on one side of the matching gasket (10) inside the frame groove (9), and the outer side of the matching gasket (10) is tightly attached to the outer wall of the upper cavity (5); The centers of the gas outlet (24), the conical block (21) and the piston disc (18) are arranged in a straight line, and the outer side of the moving rod (19) is slidably arranged in the inside of the upper cavity (5).

2. The precision injection mold for a plastic part of an automobile according to claim 1, characterized in that: The front and rear ends of the sealing sleeve (8) are communicated with air inlets (7), the outer ends of the air inlets (7) extend into a frame groove (9) in the sealing sleeve (8), and the frame groove (9) is slidably provided with a sealing mechanism.

3. The precision injection mold for a plastic part of an automobile according to claim 1, characterized in that: The bottom surfaces of the four groups of the fitting blocks (20) are combined to form a seamless cylinder, and the diameter of the seamless cylinder is consistent with the diameter of the moving rod (19); the top of the fitting block (20) is connected to the bottom of the moving rod (19) through a torsion spring; and the outside of the fitting block (20) is slidably arranged in the inside of the upper cavity (5).

4. The precision injection mold for a plastic part of an automobile according to claim 1, characterized in that: The inside of the piston disc (18) is provided with a conical groove (22), and the inside of the conical groove (22) is fitted with a conical block (21); the bottom of the conical block (21) is fixed to the top of a matching spring (23); the bottom of the matching spring (23) is fixed to the inside of a moving rod (19); the inside of the moving rod (19) is provided with a cavity, and the bottom of the cavity is connected to an air outlet (24).

5. The precision injection mold for a plastic part of an automobile according to claim 4, characterized in that: The elastic force of the matching spring (23) is greater than that of the connecting spring (17), and the conical block (21) and the inside of the conical groove (22) form an elastic sliding structure through the matching spring (23).

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