A pressure sensor upper shell injection molding process and molding mold thereof

Abstract

The present invention discloses a pressure sensor upper shell injection molding process and a molding mold thereof, which belongs to the field of injection mold technology, including a mother mold and a male mold and a molding mechanism used in conjunction with each other; an automatic locking mechanism and a molding mechanism are arranged between the mother mold and the male mold; the molding mechanism includes a molding boss, a molding groove and an auxiliary fixing component, and a plurality of glue flow channels for the flow of glue are also arranged on the molding boss. Through the above-mentioned method, the present invention realizes one-time molding of three completely independent areas of a silicone part through three independent glue inlet points and three overflow glue points, and ensures that the finished silicone part of the injection molding is full and has no defects, and its contour also meets the set value; through the cooperation of one-shot injection molding and two-shot injection molding, the semi-finished product of the upper shell of the pressure sensor and the silicone part are separately injected to obtain the finished product of the upper shell of the pressure sensor, which effectively improves the efficiency of injection molding and improves the overall quality of the injection molded product.

Description

Technical Field

[0001] The invention relates to the technical field of injection molds, and in particular to an injection molding process for an upper shell of a pressure sensor and a molding mold thereof. Background Art

[0002] Pressure sensor is a common sensor device, which is widely used in industrial control, medical equipment, automotive electronics, aerospace and other fields;

[0003] like Figure 1 and Figure 2 As shown, the upper shell of the pressure sensor is usually composed of a semi-finished upper shell of the pressure sensor, a bushing and a silicone part, and the silicone part has three independent areas. The method of molding each component separately has low production efficiency, long cycle and high cost. It is difficult to mold the whole at one time, and the silicone part is prone to defects such as burrs, cracks or bubbles during the molding process.

[0004] Based on this, the present invention designs an injection molding process for an upper shell of a pressure sensor and a molding mold thereof to solve the above problems. Summary of the invention

[0005] In view of the above-mentioned shortcomings of the prior art, the present invention provides an injection molding process for an upper shell of a pressure sensor and a molding mold thereof.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0007] A pressure sensor upper housing injection molding process comprises the following steps:

[0008] Step 1: The semi-finished raw materials of the upper shell of the pressure sensor are sequentially subjected to material quality control, storage and drying operations, and the semi-finished raw materials of the upper shell of the pressure sensor are added into the barrel of the injection molding machine for one shot to melt, and the melting temperature is 250-270°C; the bushing is subjected to material quality control and storage operations, and the bushing is implanted into the one-shot molding mold of the injection molding machine;

[0009] Step 2: The first shot mold is closed and the injection molding machine is started to squeeze the molten upper shell semi-finished raw material into the first shot mold with an extrusion force of 800-1800kgf / cm 3 , the holding time is 2.5s, the semi-finished product of the upper shell of the pressure sensor is formed, the one-shot molding operation of the finished product of the upper shell of the pressure sensor is completed, and the one-shot molding finished product is ejected;

[0010] Step 3: The one-shot molding finished product is transferred by the robot, and the appearance of the one-shot molding finished product is inspected by the CCD component. The qualified one-shot molding finished product is automatically loaded on the tray, and the appearance of the one-shot molding finished product is re-inspected manually, and the qualified one-shot molding finished product is put into storage;

[0011] Step 4: Control the incoming quality of silicone raw materials and put them into storage. Inject the silicone raw materials into the barrel of the injection molding machine for the second shot and melt them at a melting temperature of 15-20°C. Insert the first shot molded product into the second shot mold.

[0012] Step 5: The two-shot molding mold is closed and the molding cavity is preheated by a high-frequency preheating machine at a preheating temperature of 120-130°C;

[0013] Step 6: Start extruding the molten silicone raw material into the two-shot molding mold, with an extrusion force of 30-55 Bar and a holding time of 1.0 s. The three independent first silicone parts, the second silicone parts and the third silicone parts of the silicone part are molded at one time, completing the two-shot molding of the finished product of the upper shell of the pressure sensor.

[0014] Step 7: Separate the two-shot molding mold, take out the sprue, eject the finished product of the upper shell of the pressure sensor and clean the mold surface;

[0015] Step 8: The finished upper shell of the pressure sensor is divided into holes and loaded onto trays, and then put into storage after cleaning, drying and appearance inspection.

[0016] In order to better achieve the purpose of the present invention, the present invention also provides a molding die, including a female die and a male die used in conjunction with each other and a molding mechanism;

[0017] A plurality of positioning rods are fixedly mounted at the lower end of the female mold, and a plurality of positioning holes corresponding to and mating with the positioning rods are opened at the upper end of the male mold; an automatic locking mechanism for locking the female mold and the male mold and a molding mechanism for molding silicone parts are arranged between the female mold and the male mold;

[0018] The molding mechanism includes a molding boss, a molding groove and an auxiliary fixing component. The molding boss is fixedly installed at the lower end of the female mold, and a molding groove matching the molding boss is provided at the upper end of the male mold. A molding cavity for molding silicone parts is formed between the molding boss and the molding groove; two groups of auxiliary fixing components are provided and symmetrically distributed on both sides of the molding boss, and the auxiliary fixing components are used to limit the bushing; a plurality of glue flow channels for the flow of glue are also provided on the molding boss.

[0019] Furthermore, the auxiliary fixing assembly includes a pressure rod, a third spring and a protrusion. Multiple pressure rods are arranged at the lower end of the mother mold and correspond one by one to the bushing of the finished upper shell of the pressure sensor. The upper end of the pressure rod is located on the inner side of the mother mold and is limitedly and slidably connected to the mother mold. The third spring is fixedly installed between the upper end of the pressure rod and the mother mold; the lower end of the pressure rod is provided with a protrusion for positioning the hole of the bushing.

[0020] Furthermore, the first glue inlet point and the first glue overflow point cooperate to form a first silicone part, the second glue inlet point and the second glue overflow point cooperate to form a second silicone part, and the third glue inlet point and the third glue overflow point cooperate to form a third silicone part.

[0021] Furthermore, the gate rupture diameters of the second glue inlet point, the third glue inlet point and the third glue overflow point are 0.07 mm.

[0022] Furthermore, the automatic locking mechanism includes a locking rod and a locking plate; a slide groove is symmetrically provided on the front and rear sides of the inside of the male mold, and a locking plate is provided in the slide groove and is limitedly slidably connected to the slide groove; each locking plate is symmetrically provided with a locking groove on the left and right sides; a plurality of locking rods corresponding to the locking grooves are provided at the lower end of the female mold, and the locking rods are limitedly slidably connected to the female mold; the lower end of the locking rod adopts a ball head structure, and the lower end of the locking rod is also provided with a clamping groove that matches the locking groove, and the locking rod and the locking plate are clamped through the locking groove and the clamping groove;

[0023] Furthermore, a convex plate is fixedly installed on the upper end of the locking rod, and a receiving groove is provided in the mother mold, which is connected to the convex plate in a limited sliding manner; the first spring is sleeved on the outside of the locking rod, and the upper and lower ends of the first spring are respectively abutted against the convex plate and the bottom of the receiving groove; an H-shaped groove is provided in the middle of the locking plate, and the second spring is located on the sliding groove and the inner side of the H-shaped groove.

[0024] Furthermore, a plurality of heat preservation pipes for heat preservation are arranged inside the female mold and the male mold.

[0025] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention realizes one-time molding of three completely independent areas of the silicone part through three independent glue inlet points and three glue overflow points, and ensures that the finished injection-molded silicone part is full and defect-free, and its contour also meets the set value.

[0026] 2. The semi-finished upper shell of the pressure sensor and the silicone parts are separately injection molded by one-shot injection molding and two-shot injection molding to obtain the finished upper shell of the pressure sensor, which effectively improves the efficiency of injection molding and improves the overall quality of injection molded products. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 This is a structural stereogram of the finished product of the upper housing of the pressure sensor;

[0029] Figure 2It is a structural stereogram of the silicone parts;

[0030] Figure 3 A three-dimensional molding die of the present invention Figure 1 ;

[0031] Figure 4 A sectional view of a molding die of the present invention Figure 1 ;

[0032] Figure 5 A three-dimensional molding die of the present invention Figure 2 ;

[0033] Figure 6 A sectional view of a molding die of the present invention Figure 2 ;

[0034] Figure 7 A three-dimensional molding die of the present invention Figure 3 ;

[0035] Figure 8 A three-dimensional molding die of the present invention Figure 4 ;

[0036] Fig. 9 The three-dimensional structure of the silicone parts after molding Figure 1 ;

[0037] Fig.10 The three-dimensional structure of the silicone parts after molding Figure 2 ;

[0038] Fig.11 This is a partial cross-sectional view of the silicone part after molding;

[0039] Fig.12 This is a partial schematic diagram of the silicone part after molding.

[0040] The numbers in the figure represent:

[0041] 1. Finished product of upper shell of pressure sensor; 11. Semi-finished product of upper shell of pressure sensor; 12. Bushing; 13. Silicone part; 131. First silicone part; 132. Second silicone part; 133. Third silicone part; 2. Female mold; 21. Positioning rod; 3. Male mold; 31. Positioning hole; 4. Automatic locking mechanism; 41. Locking rod; 42. Locking plate; 43. Locking groove; 44. Card slot; 45. Slide groove; 46. H-shaped groove; 47. First spring; 48. Second spring; 5. Molding mechanism; 51. Molding boss; 52. Molding groove; 53. Press rod; 54. Third spring; 55. Bump; 56. Glue flow channel; 561. First glue inlet point; 562. First glue overflow point; 563. Second glue inlet point; 564. Second glue overflow point; 565. Third glue inlet point; 566. Third glue overflow point. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] Embodiment 1: In some embodiments, please refer to the drawings of the specification Figure 1-Figure 12 , a pressure sensor upper housing injection molding process, comprising the following steps:

[0044] Step 1: The raw material of the semi-finished product 11 of the upper shell of the pressure sensor is subjected to material quality control, storage and drying operations in sequence, and the raw material of the semi-finished product 11 of the upper shell of the pressure sensor is added into the barrel of the injection molding machine for one shot to melt, and the melting temperature is 250-270°C; the bushing 12 is subjected to material quality control and storage operations, and the bushing 12 is implanted into the one-shot molding mold of the injection molding machine;

[0045] Step 2: First shot mold clamping process, start the injection molding machine to squeeze the molten upper shell semi-finished product 11 raw material into the first shot mold, the extrusion force is 800-1800kgf / cm 3 , the holding time is 2.5s, the semi-finished product 11 of the upper shell of the pressure sensor is formed, the one-shot molding operation of the finished product 1 of the upper shell of the pressure sensor is completed, and the one-shot molding finished product is ejected;

[0046] Step 3: The one-shot molding finished product is transferred by the robot, and the appearance of the one-shot molding finished product is inspected by the CCD component. The qualified one-shot molding finished product is automatically loaded on the tray, and the appearance of the one-shot molding finished product is re-inspected manually, and the qualified one-shot molding finished product is put into storage;

[0047] Step 4: Perform incoming material quality control and warehousing operations on the raw materials of the silicone parts 13, inject the raw materials of the silicone parts 13 into the barrel of the injection molding machine for the second shot and melt them, the melting temperature is 15-20°C; implant the finished product of the first shot into the second shot molding mold,

[0048] Step 5: The two-shot molding mold is closed and the molding cavity is preheated by a high-frequency preheating machine at a preheating temperature of 120-130°C;

[0049] Step 6: Start extruding the molten silicone material 13 into the two-shot molding mold, with an extrusion force of 30-55 Bar and a holding time of 1.0 s, and mold the three independent first silicone parts 131, second silicone parts 132 and third silicone parts 133 of the silicone part 13 at one time, completing the two-shot molding operation of the pressure sensor upper shell finished product 1;

[0050] Step 7: Separate the two-shot molding mold, take out the sprue, eject the finished product 1 of the upper shell of the pressure sensor and clean the mold surface;

[0051] Step 8: Place the finished product of the upper shell of the pressure sensor into a tray and put it into storage after cleaning, drying and appearance inspection.

[0052] The present invention realizes separate injection molding of the semi-finished upper shell of the pressure sensor and the silicone part through one-shot injection molding and two-shot injection molding to obtain the finished upper shell of the pressure sensor, effectively improving the efficiency of injection molding

[0053] Embodiment 2: In some embodiments, Figure 1-Figure 12 As shown, as a preferred embodiment of the present invention, a molding die includes a female mold 2 and a male mold 3 used in conjunction with each other and a molding mechanism 5;

[0054] A plurality of positioning rods 21 are fixedly mounted on the lower end of the female mold 2, and a plurality of positioning holes 31 corresponding to and mating with the positioning rods 21 are provided on the upper end of the male mold 3; an automatic locking mechanism 4 for locking the female mold 2 and the male mold 3 and a molding mechanism 5 for molding the silicone member 13 are arranged between the female mold 2 and the male mold 3;

[0055] The molding mechanism 5 includes a molding boss 51, a molding groove 52 and an auxiliary fixing assembly. The molding boss 51 is fixedly mounted on the lower end of the female mold 2, and a molding groove 52 matching the molding boss 51 is provided on the upper end of the male mold 3. A molding cavity for molding the silicone member 13 is formed between the molding boss 51 and the molding groove 52; two groups of auxiliary fixing assemblies are provided and symmetrically distributed on both sides of the molding boss 51, and the auxiliary fixing assemblies are used to limit the bushing 12; a plurality of glue flow channels 56 for the flow of glue are also provided on the molding boss 51;

[0056] In some embodiments, Figure 6As shown, the auxiliary fixing assembly includes a pressure rod 53, a third spring 54 and a protrusion 55. A plurality of pressure rods 53 are arranged at the lower end of the female mold 2 and correspond one by one to the bushing 12 of the finished upper shell 1 of the pressure sensor. The upper end of the pressure rod 53 is located on the inner side of the female mold 2 and is connected to the female mold 2 by limited sliding. The third spring 54 is fixedly installed between the upper end of the pressure rod 53 and the female mold 2. The lower end of the pressure rod 53 is provided with a protrusion 55 for positioning the hole of the bushing 12. When the female mold 2 and the male mold 3 are closed, the bushing 12 is pre-positioned by the protrusion 55 at the end of the pressure rod 53. When the female mold 2 and the male mold 3 are just separated, the protrusion 55 is still located on the inner side of the bushing 12 to maintain the positioning effect of the bushing 12, thereby ensuring that the finished injection-molded silicone part 13 remains stable at all times.

[0057] In some embodiments, Figure 9-12 As shown, the first glue feed point 561 and the first glue overflow point 562 cooperate to form the first silicone part 131, the second glue feed point 563 and the second glue overflow point 564 cooperate to form the second silicone part 132, and the third glue feed point 565 and the third glue overflow point 566 cooperate to form the third silicone part 133; each group of glue feed points and glue overflow points are located on the opposite side of their molding area; through three independent glue feed points and three glue overflow points, three completely independent areas of the silicone part 13 are molded at one time, and the finished injection-molded silicone part 13 is full and defect-free.

[0058] The gate rupture diameters of the second glue inlet point 563 , the third glue inlet point 565 and the third glue overflow point 566 are 0.07 mm, ensuring the contour of the molded second silicone part 132 and the second silicone part 132 .

[0059] In some embodiments, Figure 4 and 5 As shown, the automatic locking mechanism 4 includes a locking rod 41 and a locking plate 42; a slide groove 45 is symmetrically provided on the front and rear sides of the inside of the male mold 3, and a locking plate 42 is provided in the slide groove 45 and is limitedly slidably connected to the slide groove 45; a locking groove 43 is symmetrically provided on the left and right sides of each locking plate 42; a plurality of locking rods 41 corresponding to the locking groove 43 are provided at the lower end of the female mold 2, and the locking rod 41 is limitedly slidably connected to the female mold 2; the lower end of the locking rod 41 adopts a ball head structure, and the lower end of the locking rod 41 is also provided with a clamping groove 44 that matches the locking groove 43, and the locking rod 41 and the locking plate 42 are clamped through the locking groove 43 and the clamping groove 44;

[0060] A convex plate is fixedly installed on the upper end of the locking rod 41, and a receiving groove is provided in the mother mold 2, which is connected to the convex plate in a limited sliding manner; the first spring 47 is sleeved on the outside of the locking rod 41, and the upper and lower ends of the first spring 47 are respectively abutted against the convex plate and the bottom of the receiving groove; an H-shaped groove 46 is provided in the middle of the locking plate 42, and the second spring 48 is located inside the slide groove 45 and the H-shaped groove 46.

[0061] In the present invention, when the female mold 2 and the male mold 3 are closed, the locking rod 41 passes through the male mold 3 and contacts the locking plate 42. After the ball head of the locking rod 41 pushes the locking plate 42 away, the locking rod 41 extends into the locking groove 43. The second spring 48 drives the locking plate 42 to reset, so that the locking plate 42 is locked with the locking groove 43 and the locking groove 44 of the locking rod 41, thereby achieving a quick locking effect of the female mold 2 and the male mold 3, increasing the stability of the molding of the silicone part 13, and improving the qualified rate of the finished product.

[0062] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pressure sensor upper housing injection molding process, characterized in that: The following steps are involved: Step 1: The raw material of the semi-finished upper shell of the pressure sensor (11) is subjected to material quality control, storage and drying operations in sequence, and the raw material of the semi-finished upper shell of the pressure sensor (11) is added into a barrel of an injection molding machine for one shot to melt, and the melting temperature is 250-270° C.; the raw material quality control and storage operations are carried out on the bushing (12), and the bushing (12) is implanted into a one-shot molding mold of the injection molding machine; Step 2: The first shot molding mold is closed, and the injection molding machine is started to squeeze the molten upper shell semi-finished product (11) raw material into the first shot molding mold with an extrusion force of 800-1800kgf / cm 3 , forming a semi-finished product (11) of the upper shell of the pressure sensor, completing the one-shot molding operation of the finished product (1) of the upper shell of the pressure sensor, and ejecting the one-shot molded finished product; Step 3: The one-shot molding finished product is transferred by the robot, and the appearance of the one-shot molding finished product is inspected by the CCD component. The qualified one-shot molding finished product is automatically loaded on the tray, and the appearance of the one-shot molding finished product is re-inspected manually, and the qualified one-shot molding finished product is put into storage; Step 4: Perform incoming material quality control and warehousing operations on the raw materials of the silicone parts (13), inject the raw materials of the silicone parts (13) into the barrel of the injection molding machine for the second shot to melt, and the melting temperature is 15-20° C.; implant the finished product of the first shot into the second shot molding mold, Step 5: The two-shot molding mold is closed and the molding cavity is preheated by a high-frequency preheating machine at a preheating temperature of 120-130°C; Step 6: Start extruding the molten silicone material (13) into the two-shot molding die, with an extrusion force of 30-55 Bar, and mold the three independent first silicone parts (131), second silicone parts (132) and third silicone parts (133) of the silicone part (13) at one time, thus completing the two-shot molding operation of the finished upper shell of the pressure sensor (1); Step 7: Separate the two-shot molding mold, remove the sprue, eject the finished product (1) of the upper shell of the pressure sensor, and clean the mold surface; Step 8: The finished upper shell of the pressure sensor (1) is divided into holes and placed on a plate, and then put into storage after cleaning, drying and appearance inspection.

2. A molding die, the molding die is a two-shot molding die proposed in step 4 to step 7 of claim 1, the molding die comprises a female mold (2) and a male mold (3) used in conjunction with each other and a molding mechanism (5), characterized in that: A plurality of positioning rods (21) are fixedly mounted on the lower end of the female mold (2), and a plurality of positioning holes (31) corresponding to and mating with the positioning rods (21) are provided on the upper end of the male mold (3); an automatic locking mechanism (4) for locking the female mold (2) and the male mold (3) and a molding mechanism (5) for molding the silicone member (13) are provided between the female mold (2) and the male mold (3); The molding mechanism (5) comprises a molding boss (51), a molding groove (52) and an auxiliary fixing assembly. The molding boss (51) is fixedly mounted on the lower end of the female mold (2), and the molding groove (52) matching the molding boss (51) is provided on the upper end of the male mold (3). A molding cavity for molding a silicone member (13) is formed between the molding boss (51) and the molding groove (52). Two groups of auxiliary fixing assemblies are provided and symmetrically distributed on both sides of the molding boss (51). The auxiliary fixing assemblies are used to limit the bushing (12). The molding boss (51) is also provided with a plurality of glue flow channels (56) for the flow of glue.

3. The molding die according to claim 2, characterized in that: The auxiliary fixing assembly comprises a pressure rod (53), a third spring (54) and a protrusion (55); a plurality of pressure rods (53) are arranged at the lower end of the mother mold (2) and correspond one by one to the bushing (12) of the finished upper shell of the pressure sensor (1); the upper end of the pressure rod (53) is located on the inner side of the mother mold (2) and is connected to the mother mold (2) in a limited sliding manner; the third spring (54) is fixedly installed between the upper end of the pressure rod (53) and the mother mold (2); and the lower end of the pressure rod (53) is provided with a protrusion (55) for positioning the hole of the bushing (12).

4. The molding die according to claim 2, characterized in that: The first glue inlet point (561) and the first glue overflow point (562) cooperate to form a first silicone part (131), the second glue inlet point (563) and the second glue overflow point (564) cooperate to form a second silicone part (132), and the third glue inlet point (565) and the third glue overflow point (566) cooperate to form a third silicone part (133).

5. The molding die according to claim 4, characterized in that: The gate break diameters of the second glue inlet point (563), the third glue inlet point (565) and the third glue overflow point (566) are 0.07 mm.

6. The molding die according to claim 2, characterized in that: The automatic locking mechanism (4) comprises a locking rod (41) and a locking plate (42); a sliding groove (45) is symmetrically provided on the front and rear sides of the interior of the male mold (3); a locking plate (42) is provided in the sliding groove (45) and is connected to the sliding groove (45) in a limited sliding manner; a locking groove (43) is symmetrically provided on the left and right sides of each locking plate (42); a plurality of locking rods (41) corresponding to the locking grooves (43) are provided at the lower end of the female mold (2); the locking rods (41) are connected to the female mold (2) in a limited sliding manner; the lower end of the locking rod (41) adopts a ball head structure, and the lower end of the locking rod (41) is also provided with a clamping groove (44) matching the locking groove (43); the locking rod (41) and the locking plate (42) are clamped through the locking groove (43) and the clamping groove (44).

7. The molding die according to claim 6, characterized in that: A convex plate is fixedly mounted on the upper end of the locking rod (41), and a receiving groove is provided in the female mold (2) and is connected to the convex plate in a limited sliding manner; a first spring (47) is sleeved on the outer side of the locking rod (41), and the upper and lower ends of the first spring (47) are respectively in contact with the convex plate and the bottom of the receiving groove; an H-shaped groove (46) is provided in the middle of the locking plate (42), and a second spring (48) is located inside the sliding groove (45) and the H-shaped groove (46).

8. The molding die according to claim 2, characterized in that: A plurality of heat-insulating pipes for heat preservation are arranged inside the female mold (2) and the male mold (3).

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