Plastic molds for fiber-reinforced polyphenylene sulfide precision products

Abstract

The invention relates to a plastic mold for a fiber-reinforced polyphenylene sulfide precision product, which belongs to the field of plastic molds and injection molding technology, and mainly relates to a plastic mold for a fiber-reinforced polyphenylene sulfide precision thin-wall product. The product is mainly used in high-precision functional injection molding parts in automobiles. By setting a pre-extraction action mechanism on the mold and using a vacuum generator in conjunction with a vacuum generator and a blow combiner, the problem of surface defects such as burrs, burnt surfaces, and obvious weld marks that are easily generated during molding of fiber-reinforced polyphenylene sulfide resin is solved, and the shrinkage caused by vacuum when ejecting tubular plastic products with an average wall thickness of less than 1.0 mm is prevented, thereby reducing the defective rate and improving production efficiency.

Description

Technical Field

[0001] The patent of this invention belongs to the field of plastic molds and injection molding technology, and mainly involves plastic molds for fiber-reinforced polyphenylene sulfide precision thin-walled products. The products are mainly used in high-precision functional injection molded parts in automobiles. Background Art

[0002] At present, for the precision cylindrical plastic parts with an average wall thickness of less than 1.0 mm in new automobile fuel pumps and electronic water pumps, most of them are produced by injection molding using polyetheretherketone resin or fiber-reinforced polyphthalamide resin. Since these two resins are expensive, the product cost performance is not high. In order to solve this problem, resin manufacturers have developed fiber-reinforced polyphenylene sulfide resin, which has high heat resistance, excellent mechanical strength, rigidity, flame retardancy, chemical resistance, electrical properties, dimensional stability, wear resistance, and creep resistance. It is cheap and cost-effective. However, due to its very narrow molding window, it is very easy for the product to burn, have gas marks, burrs and other surface defects during injection molding. Resin powder often remains in the gap between mold parts, resulting in frequent burning of the product, a very high defect rate, and very high maintenance frequency and cost. The traditional practice is to use post-injection processing methods, such as ultrasonic deburring, dry ice deburring and other methods to ensure the surface quality of the product. The cost of post-processing also reduces the cost performance of the product. How to ensure the surface quality of fiber-reinforced polyphenylene sulfide precision thin-walled products and reduce costs is a problem that needs to be solved. Summary of the invention

[0003] The purpose of the present invention is to provide a plastic mold for fiber-reinforced polyphenylene sulfide precision products. The mold adopts a vacuum and blowing device in conjunction with a mold opening first vacuum mechanism, which ensures that the surface of tubular plastic products with an average wall thickness of less than 1.0 mm is not burned, the product has no shrinkage marks or deformation, and the burrs are less than 0.05 mm, so that the product can be produced smoothly.

[0004] The technical problem to be solved by the present invention is to provide a plastic mold for fiber-reinforced polyphenylene sulfide precision thin-walled products, so as to solve the common problems of low yield rate, many surface defects of products, burning of the edge of the parting line by the fiber-reinforced polyphenylene sulfide resin after mass production of the mold, vacuum product deformation of thin-walled and deep products during ejection, and the need for post-processing after injection molding to ensure product quality, so that the products after injection molding can directly meet the technical requirements and usage requirements of the drawings.

[0005] The technical solution adopted by the present invention: The structure of the plastic mold of the fiber reinforced polyphenylene sulfide precision product includes: a fixed mold base plate 1, a hot runner plate 2, a fixed mold plate 3, a fixed mold insert 4, a movable mold insert 5, a movable mold plate 6, a first draw plate 7, a surface needle plate 8, a bottom needle plate 9, a square iron 10, a movable mold base plate 11, a valve needle hot runner 12, a product 13, a movable mold insert 14, The movable mold insert seal ring 15, the ejector rod 16, the movable mold plate seal ring 17, the movable mold core 18, the vacuum generator A19, the first plate seal ring 20, the movable mold core seal ring 21, the spring 22, the limit bolt 23, the ejector rod seal ring 24, the ejector rod seal sleeve 25, the vacuum generator B26, the negative pressure monitor 27, the vacuum generation and blowing combiner 28; The connection relationship of the plastic mold of the fiber reinforced polyphenylene sulfide precision product is as follows: the movable mold insert 5 is provided with a conical outer positioning surface, a conical inner positioning surface, a main exhaust duct, a main exhaust duct air path hole, an exhaust surface and a pin hole, and the movable mold insert 1 4 is provided with a conical positioning groove and a pin hole, the movable mold insert 5 and the movable mold insert 14 have a clearance fit with the conical surface, and are connected and fixed by pins, the movable mold insert 5 and the movable mold plate 6 have a clearance fit and are fixed by bolt locking, the movable model core 18 is provided with a conical outer positioning surface and a push rod hole and a push rod 16 clearance fit, the movable model core 18 and the first draw plate 7 have a clearance fit and are fixed by bolt locking, a sealing groove is provided on the push rod sealing sleeve 25, the push rod sealing ring 24 is placed in the push rod sealing sleeve 25, the push rod 16 slides in the push rod sealing sleeve 25, and is sealed by the push rod sealing ring 24, and the push rod sealing sleeve 25 is fixed with the first draw plate 7. The draw plate 7 is an interference fit, a limit bolt hole is set on the first draw plate 7, and the limit bolt 23 is threadedly connected with it to limit the position, a heat-insulating bakelite is set between the vacuum generator A19 and the movable template 6 and fixed by bolt locking, a heat-insulating bakelite is set between the negative pressure monitor 27 and the movable template 6 and fixed by bolt locking, a heat-insulating bakelite is set between the negative pressure monitor 27 and the first draw plate 7 and fixed by bolt locking, a heat-insulating bakelite is set between the vacuum generation and blowing combiner 28 and the square iron 10 and fixed by bolt locking, a heat-insulating bakelite is set between the vacuum generator B26 and the square iron 10 and fixed by bolt locking. The bolts are locked and fixed, and the square iron 10 is provided with an air path hole and a sealing ring groove, and the movable mold bottom plate 11 and the first draw plate 7 are connected by bolts and locked to limit and seal the air path. A through air path is provided in the movable template 6, one end of the air path is connected to the vacuum generator A19, and the other end is connected to the negative pressure monitor 27. The air path provided in the movable template 6 is connected to the main exhaust duct air path hole on the movable mold insert 5. A through air path is provided in the first draw plate 7, one end of which is connected to the negative pressure monitor 27, one end is connected to the vacuum generator B26 on the square iron 10, and one end is connected to the vacuum generation and blowing combiner 28 on the square iron 10.

[0006] Working principle of plastic mold for fiber reinforced polyphenylene sulfide precision products: in closed mold state, vacuum generator A19, vacuum generator B26, vacuum generation and blowing combination device 28 work at the same time to start extracting residual air in thin-wall cavity, negative pressure monitor 27 simultaneously displays negative pressure value in air channel of moving template 6 and first draw plate 7, when negative pressure value reaches set pressure, injection starts and fills cavity, after pressure holding and cooling, vacuum generator A19, vacuum generator B26, vacuum generation and blowing combination device 28 stop working at the same time; when mold is opened, vacuum generation and blowing combination device 28 starts blowing action, blows out gas through first draw plate The air passage arranged in 7 enters the dynamic model core 18, and at the same time, the first draw plate 7 is separated from the dynamic template 6 by the force of the spring, and the product 13 and the dynamic model core 18 are separated accordingly, and the inner wall of the product 13 and the dynamic model core 18 form a closed space, and the space is filled with the gas emitted by the vacuum generating and blowing combiner 28; the mold continues to open, and the ejector pin 16 slides in the ejector pin sealing sleeve 25 to eject the product 13, and the vacuum generating and blowing combiner 28 continues to blow, and the residual resin particles in the ejector pin 16 and the inner wall of the ejector pin hole of the dynamic model core 18 are blown out, and the ejector pin 16 retreats, the blowing action of the vacuum generating and blowing combiner 28 ends, and a molding cycle ends.

[0007] The beneficial effects of the present invention are as follows: by arranging a pre-extraction action mechanism on the mold and using a vacuum generator in conjunction with a vacuum generation and blowing combiner, the problem of surface defects such as burrs, surface burnt, and obvious weld marks easily generated in fiber-reinforced polyphenylene sulfide resin during molding is solved, and the shrinkage caused by vacuum when ejecting tubular plastic products with an average wall thickness of less than 1.0 mm is prevented, thereby reducing the defective rate and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The following is a detailed description of the embodiments with reference to the accompanying drawings.

[0009] Figure 1 It is the overall assembly drawing of the mold.

[0010] Figure 2 This is the assembly drawing after the mold is opened and the leaf spring is pulled out.

[0011] Figure 3 It is an isometric drawing of the mold movable platen, movable mold insert and other parts after assembly.

[0012] Figure 4 It is a top view of the mold movable platen, movable mold insert and other parts after assembly.

[0013] Figure 5 It is an isometric view of the vacuum air path direction of the mold moving platen.

[0014] Figure 6 It is a top view of the vacuum air path direction of the mold moving platen.

[0015] Figure 7 It is an isometric view of the mold after the first draw plate is assembled with the square iron and the movable mold bottom plate.

[0016] Figure 8 This is a top view of the mold after the first draw plate is assembled with the square iron and the movable mold bottom plate.

[0017] Fig. 9 This is the main view of the mold after the first draw plate is assembled with the square iron and the movable mold bottom plate.

[0018] Fig.10 It is a top view of the direction of the air path when the mold is first drawn out to draw the vacuum.

[0019] Fig.11 It is an isometric view of the air path direction of the vacuum generation and the air blowing of the air blower after the mold is opened.

[0020] In the figure, 1 is a fixed mold base plate; 2 is a hot runner plate; 3 is a fixed mold plate; 4 is a fixed mold insert; 5 is a movable mold insert; 6 is a movable mold plate; 7 is a first draw plate; 8 is a surface needle plate; 9 is a bottom needle plate; 10 is a square iron; 11 is a movable mold base plate; 12 is a valve needle hot runner; 13 is a product; 14 is a movable mold insert; 15 is a sealing ring of a movable mold insert; 16 is a push rod; 17 is a sealing ring of a movable mold plate; 18 is a movable mold core; 19 is a vacuum generator A; 20 is a sealing ring of a first draw plate; 21 is a sealing ring of a movable mold core; 22 is a spring; 23 is a limit bolt; 24 is a push rod sealing ring; 25 is a push rod sealing sleeve; 26 is a vacuum generator B; 27 is a negative pressure monitor; 28 is a vacuum generator and a blow combiner. DETAILED DESCRIPTION

[0021] The specific embodiments of the invention are described in detail below with reference to technical texts and drawings.

[0022] Assembly of the fixed mold part: install the fixed mold insert 4 into the fixed mold plate 3 and fit them with clearance, and fix them by bolts, assemble the fixed mold plate 3 and the hot runner plate 2 and fix them by bolts, install the hot nozzle in the valve needle hot runner 12 into the fixed mold insert 4, install the diverter plate in the valve needle hot runner 12 into the hot runner plate 2, assemble the fixed mold base plate 1 and the hot runner plate 2 and fix them by bolts, insert the valve needle in the valve needle hot runner 12 into the hot nozzle, install the valve needle hot runner 12 cylinder into the fixed mold base plate and fix them by bolts.

[0023] Assembly of the movable mold part: fit the movable mold insert 14 with the conical surface of the movable mold insert 5 and lock it with a pin, press the movable mold insert seal 15 into the seal groove of the movable mold insert 5, press the movable mold plate seal 17 into the movable mold plate 6, install the movable mold insert 5 assembly into the movable mold plate 6, and fix it with bolts (see Figure 3 , 4), press the first-drawn plate sealing ring 20 into the sealing ring groove of the first-drawn plate 7, press the dynamic model core sealing ring 21 into the first-drawn plate 7, install the dynamic model core 18 into the first-drawn plate 7 and lock it with bolts, press the ejector rod sealing ring 24 into the ejector rod sealing sleeve 25, and press the ejector rod sealing sleeve 25 into the first-drawn plate 7 with an interference fit, put the spring 22 into the spring groove of the first-drawn plate 7, pre-position the first-drawn plate 7 and the dynamic template 6, screw the limiting bolt 23 into the limiting hole, install the ejector rod 16 into the surface needle plate 8, and the bottom needle plate 9 and the surface needle plate 8 are locked and fixed by bolts, and the ejector rod 1 on the assembly is installed. 6 is introduced into the ejector hole of the dynamic model core 18, the dynamic mold bottom plate 11, the square iron 10 and the first draw plate 7 are fixed by bolts, the vacuum generator A19 is installed on the insulation bakelite and fixed by bolts with the dynamic template 6, the negative pressure monitor 27 is installed on the insulation bakelite and fixed by bolts with the dynamic template 6, the negative pressure monitor 27 is installed on the insulation bakelite and fixed by bolts with the first draw plate 7, the vacuum generator B26 is installed on the insulation bakelite and fixed by bolts with the square iron 10, the vacuum generation and blowing combination device 28 is installed on the insulation bakelite and fixed by bolts with the square iron 10 (see Figure 7 , 8 , 9).

[0024] The specific molding process is: before the mold is running, 6 bar compressed air must be connected to the vacuum generator, and after the mold is closed (see Figure 1 ), vacuum generator A19, vacuum generator B26, vacuum generation and blowing combination device 28 work simultaneously to start extracting the residual air in the thin-walled cavity. A part of the gas in the fixed mold cavity enters the main exhaust duct through the exhaust surface set on the movable mold insert 5, and enters the air path in the movable mold plate 6 through the main exhaust duct air path hole and is recovered by the vacuum generator A19 (see Figure 5 , 6 ), part of it enters the air path in the first extraction plate 7 through the ejector hole in the dynamic model core 18, and then transfers to the air path in the square iron 10, and is finally recovered by the vacuum generator B26 and the vacuum generation and blowing combination device 28 (see Fig.10 ), the negative pressure monitor 27 simultaneously displays the negative pressure values ​​in the air passages of the movable template 6 and the first draw plate 7. When the negative pressure reaches the set pressure, the injection starts and the cavity is filled. After the pressure holding and cooling are completed, the vacuum generator A19, the vacuum generator B26, and the vacuum generation and blowing combination device 28 stop working at the same time; the mold is opened, and the vacuum generation and blowing combination device 28 starts blowing. The blown gas enters the movable model core 18 through the air passage set in the first draw plate 7. At the same time, the first draw plate 7 is separated from the movable template 6 by the force of the spring (see Figure 2), the product 13 and the dynamic model core 18 are separated, and the inner wall of the product 13 and the dynamic model core 18 form a closed space, which is filled with the gas blown by the vacuum generation and blowing combination device 28; the mold continues to open, the ejector 16 slides in the ejector sealing sleeve 25 and ejects the product 13, and the vacuum generation and blowing combination device 28 continues to blow, blowing out the residual resin particles in the ejector 16 and the inner wall of the ejector hole of the dynamic model core 18 (see Fig.11 ), the ejector pin 16 retreats, the vacuum generation and the blowing action of the blowing combiner 28 are completed, and the one-step molding cycle is completed (see Figure 1 ).

[0025] The above is a superior implementation mode of the present invention. It should be pointed out that for technicians in the technical field to which the present invention belongs, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. Plastic mold for fiber-reinforced polyphenylene sulfide precision products, characterized by The structure includes: a fixed mold base plate (1), a hot runner plate (2), a fixed mold plate (3), a fixed mold insert (4), a movable mold insert (5), a movable mold plate (6), a first extraction plate (7), a surface needle plate (8), a bottom needle plate (9), a square iron (10), a movable mold base plate (11), a valve needle hot runner (12), a product (13), a movable mold insert (14), A movable mold insert seal (15), a push rod (16), a movable mold plate seal (17), a movable mold core (18), a vacuum generator A (19), a first plate seal (20), a movable mold core seal (21), a spring (22), a limit bolt (23), a push rod seal (24), a push rod seal sleeve (25), a vacuum generator B (26), a negative pressure monitor (27), and a vacuum generator and blow assembly (28); the connection relationship is that the movable mold insert (5) is provided with a conical outer positioning surface, a conical inner positioning surface, a main exhaust duct, a main exhaust duct air path hole, an exhaust surface and a pin hole, and the movable mold insert (14) is provided with a conical positioning recess The movable mold insert (5) and the movable mold insert (14) have a clearance fit between the conical surfaces and are connected and fixed by pins. The movable mold insert (5) and the movable mold plate (6) have a clearance fit between the conical surfaces and are fixed by bolts. The movable mold core (18) is provided with a conical outer positioning surface and a clearance fit between the ejector pin hole and the ejector pin (16). The movable mold core (18) and the first extraction plate (7) have a clearance fit between the conical outer positioning surface and the ejector pin hole and the ejector pin (16). The ejector pin seal sleeve (25) is provided with a sealing groove. The ejector pin seal ring (24) is placed in the ejector pin seal sleeve (25). The ejector pin (16) slides in the ejector pin seal sleeve (25) and is sealed by the ejector pin seal ring (24). The ejector pin seal sleeve (25) and the first extraction plate (7) are fixed by bolts. ) is an interference fit, a limit bolt hole is provided on the first draw plate (7), and a limit bolt (23) is threadedly connected thereto to limit the position, a heat-insulating bakelite is provided between the vacuum generator A (19) and the movable template (6) and is fixed by bolt locking, a heat-insulating bakelite is provided between the negative pressure monitor (27) and the movable template (6) and is fixed by bolt locking, a heat-insulating bakelite is provided between the negative pressure monitor (27) and the first draw plate (7) and is fixed by bolt locking, a heat-insulating bakelite is provided between the vacuum generating and blowing combiner (28) and the square iron (10) and is fixed by bolt locking, a heat-insulating bakelite is provided between the vacuum generator B (26) and the square iron (10) and is fixed by bolt locking. The square iron (10) is provided with an air path hole and a sealing ring groove, and the movable mold bottom plate (11) and the first extraction plate (7) are connected by bolts and locked to limit and seal the air path. A through air path is provided in the movable mold plate (6), one end of the air path is connected to the vacuum generator A (19), and the other end is connected to the negative pressure monitor (27). The air path provided in the movable mold plate (6) is communicated with the main exhaust duct air path hole on the movable mold insert (5). A through air path is provided in the first extraction plate (7), one end of which is connected to the negative pressure monitor (27), one end is connected to the vacuum generator B (26) on the square iron (10), and one end is connected to the vacuum generation and blowing combiner (28) on the square iron (10).

2. The plastic mold of the fiber-reinforced polyphenylene sulfide precision product according to claim 1, characterized in that: In the mold closing state, the vacuum generator A (19), the vacuum generator B (26), and the vacuum generator and air blowing combination device (28) work simultaneously to start extracting the residual air in the thin-walled cavity. The negative pressure monitor (27) simultaneously displays the negative pressure values ​​in the air passages of the moving mold plate (6) and the first draw plate (7). When the negative pressure value reaches the set pressure, the injection molding starts and the cavity is filled. After the pressure holding and cooling are completed, the vacuum generator A (19), the vacuum generator B (26), and the vacuum generator and air blowing combination device (28) stop working at the same time. When the mold is opened, the vacuum generator and air blowing combination device (28) starts the blowing action, and the blown gas enters the moving mold core (18) through the air passage set in the first draw plate (7). At the same time, the first draw plate (7) is separated from the movable mold plate (6) by the force of the spring, and the product (13) and the movable mold core (18) are separated accordingly. The inner wall of the product (13) and the movable mold core (18) form a closed space, and the space is filled with gas emitted by the vacuum generating and blowing combination device (28); the mold continues to open, and the ejector pin (16) slides in the ejector pin sealing sleeve (25) to eject the product (13). The vacuum generating and blowing combination device (28) continues to blow air to blow out the residual resin particles in the ejector pin (16) and the inner wall of the ejector pin hole of the movable mold core (18). The ejector pin (16) retreats, and the blowing action of the vacuum generating and blowing combination device (28) ends, and a molding cycle ends.

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