A nitrogen blowing structure for an injection mold

Abstract

The utility model provides a kind of nitrogen blowing structure for injection mold, it include:A plate, B plate, front die, rear die, briquetting, syringe barrel and needle tube, front die is embedded and fixed on A plate, rear die is embedded and fixed on B plate, for cooperating front die to form injection cavity, installation hole is opened in the side of rear die along first direction on B plate, L-shaped air passage is opened on B plate, the air inlet of air passage is communicated with the outside of B plate along second direction, briquetting is embedded in installation hole exactly, fixed hole is opened on the side of briquetting close to rear die, intake hole is opened on the side of briquetting away from rear die, the air outlet of air passage is communicated with intake hole, the head of syringe barrel is embedded in fixed hole, the barrel of syringe barrel extends to the profile boundary of injection cavity along first direction, needle tube is hollow tubular, one end of needle tube is inserted in intake hole, and the other end passes through briquetting and syringe barrel in sequence along first direction and then enters the middle part of injection cavity.

Description

Technical Field

[0001] This utility model belongs to the field of complex mold technology, and in particular relates to a nitrogen blowing structure for injection molds. Background Technology

[0002] like Figure 1 As shown, a common injection mold generally includes a front mold 80 and a rear mold 90. The front mold 80 includes a front mold fixing plate 81, an A plate 82, and a front mold core 83. The front mold fixing plate 81 and the A plate 82 are fixedly connected. The front mold core 83 is embedded and fixed on the A plate 82 on the side away from the front mold fixing plate 81. The rear mold 90 includes a B plate 91, a rear mold core 92, ejector pins 93, ejector plate 94, a spacer block 95, a rear mold base plate 96, and ejector rollers 97. The rear mold core 92 is embedded on the B plate 91 on the side closer to the A plate 82. The two ends of the spacer block 95 are respectively ejected and fixed between the B plate 91 and the rear mold base plate 96 along the mold opening direction, forming a movement space 98. The rear mold base plate 96 is fixed to the movable side of the injection molding machine. The ejector plate 94 is set in the motion space 98, which can be moved away from or closer to the B plate 91. One end of the ejector pin 93 is fixed in the ejector plate 94, and the other end passes through the B plate 91 and the rear mold core 92 in sequence. One end of the ejector roller 97 is connected to the drive shaft of the injection molding machine, and the other end can slide through the rear mold base plate 96 and be ejected on the ejector plate 94. When the injection molded product is completed, the B plate 91 is driven by the rear mold base plate 96 to gradually move away from the A plate 82 until the mold is opened. The injection molded product left on the rear mold 90 is ejected by the ejector pin 93 along the mold opening direction under the action of the ejector roller 97, and the molded part is obtained.

[0003] However, when the wall thickness of injection molded products is relatively thick, shrinkage marks are prone to appear on the appearance of the product during cooling after injection molding, affecting product quality. Therefore, how to avoid shrinkage marks on the appearance of thick-walled injection molded products during cooling after injection molding has become a problem that needs to be solved. Utility Model Content

[0004] To address the aforementioned technical problems, this utility model provides a nitrogen blowing structure for injection molds, which solves the problem of how to avoid shrinkage marks appearing on the appearance of thick-walled injection molded products during cooling after injection molding.

[0005] This utility model provides a nitrogen blowing structure for injection molds, including: an A plate, a B plate, a front mold core, a rear mold core, a pressure block, an ejector sleeve, and a needle tube. The front mold core is embedded and fixed on the A plate near the B plate, and the rear mold core is embedded and fixed on the B plate near the A plate, for cooperating with the front mold core to form an injection cavity. A mounting hole is formed on the B plate along a first direction close to the rear mold core. A vent pipe is formed on the B plate, the vent pipe being L-shaped, and the inlet of the vent pipe connecting to the outside of the B plate along a second direction to allow nitrogen to enter. The first direction is perpendicular to the second direction. The pressure block is just embedded in the mounting hole. A fixing hole is opened on the side of the pressure block near the rear mold core, and an air inlet is opened on the side of the pressure block away from the rear mold core. The air outlet of the air pipe is connected to the air inlet along the first direction. The head of the ejector sleeve is embedded in the fixing hole. The cylindrical part of the ejector sleeve extends along the first direction to the outline boundary of the injection cavity. The needle tube is hollow. One end of the needle tube is inserted into the air inlet. The other end of the needle tube passes through the pressure block and the ejector sleeve in sequence along the first direction and enters the middle of the injection cavity.

[0006] Optionally, the nitrogen blowing structure for the injection mold also includes a first sealing ring, and a first annular groove is provided on the side of the pressure block near the rear mold core. The first annular groove is located on the outer ring of the fixing hole, and the first sealing ring is embedded in the first annular groove.

[0007] Optionally, the nitrogen blowing structure for the injection mold also includes a second sealing ring, wherein a second annular groove is provided on the side of the pressure block away from the rear mold core, the second annular groove is located on the outer ring of the air inlet, and the second sealing ring is embedded in the second annular groove.

[0008] Optionally, the air intake can be a round hole.

[0009] Optionally, the outer diameter of the ejector head is equal to the inner diameter of the mounting hole, and the thickness of the ejector along the first direction is equal to the depth of the mounting hole along the first direction.

[0010] Optionally, the axial centerline of the needle tube parallel to the first direction coincides with the axial centerline of the syringe tube parallel to the first direction.

[0011] Optionally, the axial centerline of the air outlet of the ventilation tube in the first direction coincides with the axial centerline of the needle tube in the first direction.

[0012] Optionally, the air inlet of the ventilation duct is equipped with a quick-connect interface.

[0013] Optionally, the pressure block is non-rotatably embedded in the mounting hole.

[0014] Preferably, the side of the pressure block is provided with a protrusion, and the protrusion is positioned against the rear mold core along the first direction.

[0015] Compared with the prior art, the nitrogen blowing structure for injection molds provided by this utility model is ingeniously designed and can effectively ensure that no shrinkage marks appear on the appearance of injection molded products with thick walls after injection molding and cooling, thus greatly improving the quality of injection molded products. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a commonly used injection mold.

[0018] Figure 2 This is a schematic diagram of a nitrogen blowing structure for an injection mold according to an embodiment of the present invention.

[0019] Figure 3 for Figure 2 Enlarged structural diagram at point A. Detailed Implementation

[0020] To provide a better understanding of the purpose, structure, features, and functions of this utility model, detailed descriptions are provided below with reference to specific embodiments.

[0021] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0022] Please refer to the reference. Figure 2 and Figure 3 As shown, this utility model provides a nitrogen blowing structure 100 for injection molds, including: A plate 1, B plate 2, front mold core 3, rear mold core 4, pressure block 5, ejector sleeve 6, and needle tube 7.

[0023] The front mold core 3 is embedded and fixed on the side of plate A 1 near plate B 2.

[0024] The rear mold core 4 is embedded and fixed on the side of the B plate 2 near the A plate 1, and is used to cooperate with the front mold core 3 to form the injection cavity 34.

[0025] Mounting hole 21 is provided on the side of B plate 2 close to the rear mold core 4 along the first direction X. Ventilation pipe 22 is provided on B plate 2. Ventilation pipe 22 is L-shaped. The air inlet of ventilation pipe 22 is connected to the outside of B plate 2 along the second direction Y and nitrogen is introduced. The first direction X is perpendicular to the second direction Y.

[0026] The pressure block 5 is fitted into the mounting hole 21. A fixing hole 51 is provided on the side of the pressure block 5 near the rear mold core 4, and an air inlet 52 is provided on the side of the pressure block 5 away from the rear mold core 4. The air outlet of the air pipe 22 is connected to the air inlet 52 along the first direction X.

[0027] The head of the ejector sleeve 6 is fitted into the fixing hole 51, and the cylindrical part of the ejector sleeve 6 extends along the first direction X to the contour boundary of the injection cavity 34.

[0028] The needle tube 7 is hollow and tubular. One end of the needle tube 7 is inserted into the air inlet 52, and the other end of the needle tube 7 passes through the pressure block 5 and the sleeve 6 in sequence along the first direction X and enters the middle of the injection molding cavity 34.

[0029] Optionally, the nitrogen blowing structure 100 for the injection mold also includes a first sealing ring 8. A first annular groove 53 is provided on the side of the pressure block 5 near the rear mold core 4. The first annular groove 53 is located on the outer ring of the fixing hole 51, and the first sealing ring 8 is embedded in the first annular groove. This can better ensure the airtightness between the pressure block 5 and the rear mold core 4.

[0030] Optionally, the nitrogen blowing structure 100 for the injection mold also includes a second sealing ring 9. A second annular groove 54 is provided on the side of the pressure block 5 away from the rear mold core 4. The second annular groove 54 is located on the outer ring of the air inlet 52, and the second sealing ring 9 is embedded in the second annular groove. This can better ensure the airtightness between the venting pipe 22 and the air inlet 52.

[0031] Optionally, the air intake 52 can be a round hole. This allows for more stable air intake through the air intake 52.

[0032] Optionally, the outer diameter of the head of the ejector sleeve 6 is equal to the inner diameter of the mounting hole 21, and the thickness of the ejector sleeve 6 along the first direction X is equal to the depth of the mounting hole 21 along the first direction X. This facilitates stable fixing of the ejector sleeve 6.

[0033] Optionally, the axial centerline of the needle 7 parallel to the first direction X coincides with the axial centerline of the ejector sleeve 6 parallel to the first direction X. This facilitates a more stable introduction of nitrogen gas.

[0034] Optionally, the axial centerline of the outlet of the vent pipe 22, parallel to the first direction X, coincides with the axial centerline of the needle tube 7, parallel to the first direction X. This facilitates a smoother introduction of nitrogen gas.

[0035] Optionally, the air inlet of the ventilation pipe 22 is equipped with a quick-connect interface 23. This facilitates the rapid access of external nitrogen.

[0036] Optionally, the pressure block 5 is non-rotatably embedded in the mounting hole 21. This ensures airtightness during ventilation.

[0037] Preferably, the side of the pressure block 5 is provided with a protrusion 55, and the protrusion 55 abuts against the rear mold core 4 along the first direction X. This can prevent the pressure block 5 from rotating and also facilitate the alignment and installation of the pressure block 5.

[0038] The operating principle of the nitrogen blowing structure 100 for injection molds of this utility model is as follows: During injection molding, 80%-85% of the required amount of injection plastic is first injected into the injection cavity 34. Then, nitrogen gas is introduced into the center of the injection cavity 34 through the vent pipe 22, the air inlet 52, and the needle tube 7. At this time, the nitrogen gas will cause the injection plastic to cover the inner wall of the injection cavity 34 and form a hollow part 341 in the center of the injection product. In this way, the overall thickness of the injection product is not large, but because the inside is hollow, the wall thickness of the outer contour of the injection product is thinner, so that shrinkage marks are less likely to appear on the appearance during cooling.

[0039] The nitrogen blowing structure for injection molds provided by this utility model is ingeniously designed and can effectively ensure that no shrinkage marks appear on the appearance of injection molded products with thick walls after injection molding and cooling, thus greatly improving the quality of injection molded products.

[0040] This utility model has been described by the above-described embodiments; however, these embodiments are merely examples for implementing this utility model. It must be noted that the disclosed embodiments do not limit the scope of this utility model. Conversely, any modifications and refinements made without departing from the spirit and scope of this utility model are within the scope of patent protection of this utility model.

Claims

1. A nitrogen blowing structure for injection molds, characterized in that, include: Plate A, Plate B, front mold core, rear mold core, pressure block, ejector sleeve, and needle tube; The front mold core is embedded and fixed on the side of plate A near plate B; The rear mold core is embedded and fixed on the side of the B plate near the A plate, and is used to cooperate with the front mold core to form an injection cavity; The B plate has a mounting hole on one side close to the rear mold core along the first direction. The B plate has a ventilation pipe in the shape of an L. The air inlet of the ventilation pipe is connected to the outside of the B plate along the second direction and then nitrogen is introduced. The first direction is perpendicular to the second direction. The pressure block is fitted into the mounting hole. A fixing hole is provided on the side of the pressure block near the rear mold core, and an air inlet is provided on the side of the pressure block away from the rear mold core. The air outlet of the ventilation pipe is connected to the air inlet along the first direction. The head of the ejector sleeve is fitted into the fixing hole, and the sleeve portion of the ejector sleeve extends along the first direction to the contour boundary of the injection cavity. The needle is hollow and tubular. One end of the needle is inserted into the air inlet, and the other end of the needle passes through the pressure block and the sleeve in sequence along the first direction and enters the middle of the injection molding cavity.

2. The nitrogen blowing structure for injection molds as described in claim 1, characterized in that, It also includes a first sealing ring. A first annular groove is provided on the side of the pressure block near the rear mold core. The first annular groove is located on the outer ring of the fixing hole, and the first sealing ring is embedded in the first annular groove.

3. The nitrogen blowing structure for injection molds as described in claim 1, characterized in that, It also includes a second sealing ring. A second annular groove is provided on the side of the pressure block away from the rear mold core. The second annular groove is located on the outer ring of the air inlet, and the second sealing ring is embedded in the second annular groove.

4. The nitrogen blowing structure for injection molds as described in claim 1, characterized in that, The air intake is a round hole.

5. The nitrogen blowing structure for injection molds as described in claim 1, characterized in that, The outer diameter of the nozzle head is equal to the inner diameter of the mounting hole, and the thickness of the nozzle along the first direction is equal to the depth of the mounting hole along the first direction.

6. The nitrogen blowing structure for injection molds as described in claim 1, characterized in that, The axial centerline of the syringe parallel to the first direction coincides with the axial centerline of the syringe parallel to the first direction.

7. The nitrogen blowing structure for injection molds as described in claim 1, characterized in that, The axial centerline of the air outlet of the ventilation pipe, parallel to the first direction, coincides with the axial centerline of the needle tube, parallel to the first direction.

8. The nitrogen blowing structure for injection molds as described in claim 1, characterized in that, The air inlet of the ventilation duct is equipped with a quick-connect interface.

9. The nitrogen blowing structure for injection molds as described in claim 1, characterized in that, The pressure block is non-rotatably embedded in the mounting hole.

10. The nitrogen blowing structure for injection molds as described in claim 9, characterized in that, The side of the pressure block is provided with a protrusion, which abuts against the rear mold core along the first direction.

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