Injection mold capable of improving surface quality of injection molded part

Abstract

The application relates to an injection mold capable of improving the surface quality of an injection molded part, which comprises a static mold, a dynamic mold and an ejector pin, the ejector pin comprising an ejector rod and a connecting rod, a piston cavity being formed in the ejector rod, an air outlet being formed in the end face of the ejector rod close to the static mold, the air outlet being communicated with the piston cavity, the connecting rod extending into the piston cavity and sliding close to or away from the static mold, and an elastic member I being arranged between the ejector rod and the connecting rod. When the connecting rod is moved close to the static mold by a push plate, the impact force between the ejector pin and the injection molded part is buffered by the elastic member I, the hard contact damage is reduced, meanwhile, the connecting rod moves forward in the piston cavity, the gas in the piston cavity is pushed out of the air outlet, the adhering surface of the injection molded part and the dynamic mold is blown open by the gas, the adsorption force is reduced, the ejection is smoother, the ejector pin mark on the ejected injection molded part is shallower, the surface smoothness of the injection molded part is ensured, and the surface quality of the injection molded part is improved.

Description

Technical Field

[0001] This application relates to the field of injection molds, and more particularly to an injection mold that can improve the surface quality of injection molded parts. Background Technology

[0002] Injection molds are tools used to produce plastic products, and they also give plastic products their complete structure and precise dimensions.

[0003] For example, utility model patent CN203937143U discloses an injection mold, including an upper mold base, a lower mold base, a punch, a die, an ejector pin, a guide post, and a push plate. The die is fixed on the upper mold base. One end of the guide post is fixedly connected to the lower mold base, and the other end of the guide post is fixedly connected to the punch. The push plate has a guide hole adapted to the guide post, and the push plate slides up and down through the guide post. The punch has an ejector pin through-hole, and the ejector pin is fixedly connected to the push plate through the ejector pin through-hole. The inner circumferential sidewall of the ejector pin through-hole has an annular... The sliding groove contains a hollow cylindrical lubricating head that slides up and down within it. The outer circumference diameter of the lubricating head is the same as the inner circumference diameter of the sliding groove, and the inner circumference diameter of the lubricating head is the same as the inner circumference diameter of the ejector pin through hole. The outer circumference sidewall of the lubricating head has a lubrication through hole that communicates with the inner circumference sidewall. The punch contains an oil cavity, and the side of the oil cavity has an oil outlet through hole that communicates with the sliding groove. A return spring is provided on the side of the lubricating head opposite the die. The lubricating head is equipped with a guide mechanism, and the sliding groove has an oil outlet limiting step.

[0004] After injection molding, it is necessary to control the separation of the punch and the die. Then, the ejector plate drives the ejector pin to move towards the die side to eject the injection molded part. During the process of ejecting the injection molded part, the ejector pin abuts against the injection molded part and a large supporting force needs to be applied to the injection molded part. As a result, there will be deep ejector pin marks on the ejected injection molded part, which reduces the surface quality of the injection molded part and needs to be improved. Summary of the Invention

[0005] In order to improve the surface quality of injection molded parts, this application provides an injection mold that can improve the surface quality of injection molded parts.

[0006] This application provides an injection mold that can improve the surface quality of injection molded parts, and adopts the following technical solution:

[0007] An injection mold for improving the surface quality of injection molded parts includes a stationary mold, a moving mold, and an ejector pin disposed on the moving mold. The ejector pin includes an ejector rod disposed on the moving mold and a connecting rod slidably connected to the ejector rod. The connecting rod is located on the side of the ejector rod away from the stationary mold and is used to be mounted on a push plate. A piston cavity is formed on the ejector rod, and an air outlet is formed on the end face of the ejector rod near the stationary mold. The air outlet communicates with the piston cavity. The connecting rod extends into the piston cavity and slides closer to or away from the stationary mold. An elastic element is provided between the ejector rod and the connecting rod.

[0008] By adopting the above technical solution, when the push plate pushes the connecting rod to move closer to the stationary mold, the elastic element is compressed due to the ejector rod abutting against the injection molded part, which buffers the impact force between the ejector pin and the injection molded part and reduces hard contact damage. At the same time, the connecting rod moves forward in the piston cavity, pushing the gas in the piston cavity out of the vent. The gas blows open the contact surface between the injection molded part and the moving mold, reducing the suction force and making the ejection smoother. This allows the ejector rod to eject the injection molded part with less force, resulting in shallower ejector pin marks on the ejected injection molded part, ensuring the surface smoothness of the injection molded part and improving the surface quality of the injection molded part.

[0009] Optionally, the ejector pin further includes a plug slidably connected to the piston cavity. The plug is located at the air outlet and slides closer to or further away from the stationary mold. The ejector pin has an air passage one and an air passage two. The air passage one has an inlet one and an outlet one. The inlet one is located on the side of the outlet one away from the stationary mold. Both the inlet one and the outlet one are connected to the piston cavity. The air passage two has an inlet two and an outlet two. The inlet two is located on the side of the outlet two away from the stationary mold. Both the inlet two and the outlet two are connected to the piston cavity.

[0010] The plug is provided with a guide surface, which is inclined toward the air passage two in the direction of the connecting rod. A slider is slidably connected inside the outlet two. An elastic element three is provided on the connecting rod. The elastic element three abuts against the plug, so that the plug covers the air outlet and the outlet one, and the guide surface abuts against the slider.

[0011] By adopting the above technical solution, during injection molding, the vent is covered by a plug to prevent liquid material from entering the vent and causing injection defects such as bumps on the surface of the injection molded part, thereby further improving the surface quality of the injection molded part. When the connecting rod moves forward, the air pressure in the piston chamber increases, pushing the slider to move away from the second air passage. The slider presses against the guide surface, pushing the plug to overcome the elastic force of the third elastic element and move away from the injection molded part, exposing the first outlet. As the connecting rod continues to move forward, the gas in the piston chamber is discharged from the vent through the first outlet to blow open the mating surface between the injection molded part and the moving mold.

[0012] Optionally, the plug includes a sliding part slidably connected to the piston chamber and a limiting part provided on the sliding part. The guide surface is provided on the limiting part, and the limiting part is located on the side of the sliding part near the connecting rod. A limiting groove is formed on the connecting rod, and the limiting part is slidably connected to the limiting groove.

[0013] By adopting the above technical solution, a limiting part and a limiting groove are set. When the slider presses against the guide surface to push the block to move, the limiting part abuts against the inner wall of the limiting groove, thereby ensuring smooth movement of the block and reducing the situation where the block is pressed and jammed due to the slider pressing on one side.

[0014] Optionally, the push rod is provided with an elastic element two, which is located between the slider and the inner wall of the air passage two. When the elastic element two and the elastic element three are in their natural state, the slider abuts against the guide surface.

[0015] By adopting the above technical solution and setting the second elastic element, the slider is kept in a state of pressing against the guide surface, so as to ensure that the plug can be pushed to move by the slider when the connecting rod moves forward.

[0016] Optionally, the connecting rod includes a mounting portion and an extension portion disposed on the mounting portion. The mounting portion is used to mount on the push plate, the extension portion extends into the piston cavity, the elastic element is disposed outside the extension portion and located between the push rod and the mounting portion, and the moving mold covers the elastic element.

[0017] By adopting the above technical solutions, the contact between water vapor and elastic components can be reduced, corrosion of elastic components can be inhibited, and the service life of elastic components can be extended.

[0018] In summary, this application includes at least one of the following beneficial technical effects:

[0019] 1. When the push plate pushes the connecting rod to move closer to the stationary mold, the impact force between the ejector pin and the injection part is buffered by the elastic element, reducing hard contact damage. At the same time, the connecting rod moves forward in the piston cavity, pushing the gas in the piston cavity out of the vent. The gas blows open the contact surface between the injection part and the moving mold, reducing the suction force and making the ejection smoother. As a result, the ejector pin marks on the ejected injection part are shallower, ensuring the surface smoothness of the injection part and improving the surface quality of the injection part.

[0020] 2. During injection molding, the vent is covered by a plug to prevent liquid material from entering the vent and causing injection defects such as bumps on the surface of the injection molded part, thereby improving the surface quality of the injection molded part. When the connecting rod moves forward, the air pressure in the piston chamber increases, pushing the slider away from the second air passage. The slider presses against the guide surface, pushing the plug away from the injection molded part and exposing the first outlet. As the connecting rod continues to move forward, the gas in the piston chamber is discharged from the vent through the first outlet to blow open the mating surface between the injection molded part and the moving mold.

[0021] 3. A limiting part and a limiting groove are provided. When the slider presses against the guide surface to push the block to move, the limiting part abuts against the inner wall of the limiting groove, thereby ensuring smooth movement of the block and reducing the situation where the block is pressed and jammed due to the slider on one side. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of an embodiment of this application.

[0023] Figure 2 This is a cross-sectional view of an embodiment of this application.

[0024] Figure 3 for Figure 2 The enlarged view of section A mainly shows the structure of the ejector pin.

[0025] Explanation of reference numerals in the attached drawings: 1. Stationary mold; 2. Moving mold; 3. Ejector pin; 31. Ejector rod; 311. Piston chamber; 312. Air outlet; 313. Air passage one; 3131. Inlet one; 3132. Outlet one; 314. Air passage two; 3141. Inlet two; 3142. Outlet two; 32. Connecting rod; 321. Mounting part; 322. Extension part; 3221. Limiting groove; 33. Plug; 331. Sliding part; 3311. Groove; 332. Limiting part; 4. Elastic element one; 5. Guide surface; 6. Slider; 7. Elastic element two; 8. Elastic element three. Detailed Implementation

[0026] The following is in conjunction with the appendix Figures 1-3 This application will be described in further detail.

[0027] This application discloses an injection mold that can improve the surface quality of injection molded parts. See also... Figures 1-3 An injection mold that can improve the surface quality of injection molded parts includes a stationary mold 1, a moving mold 2, and several ejector pins 3. The stationary mold 1 and the moving mold 2 are arranged opposite each other and are joined together to form a cavity. Several ejector pins 3 are installed on the moving mold 2 and are spaced apart from each other.

[0028] See Figures 1-3 Each ejector pin 3 includes an ejector rod 31, a connecting rod 32, and a plug 33. The ejector rod 31 is mounted on the moving mold 2 and has a piston cavity 311. An air outlet 312 is provided on the end face of the ejector rod 31 near the stationary mold 1. The air outlet 312 is connected to the cavity and the piston cavity 311. The connecting rod 32 is located on the side of the ejector rod 31 away from the stationary mold 1. The connecting rod 32 includes a mounting part 321 and an extension part 322. The extension part 322 extends into the piston cavity 311 and slides closer to or away from the stationary mold 1. A limiting groove 3221 is provided on the end face of the extension part 322 near the stationary mold 1. The mounting part 321 is fixed to the side of the extension part 322 away from the ejector rod 31 and is used to mount on the push plate.

[0029] See Figures 1-3 An elastic element 4 is sleeved on the outer side of the extension 322. The elastic element 4 is located between the push rod 31 and the mounting part 321, and the opposite ends of the elastic element 4 are fixedly connected to the push rod 31 and the mounting part 321 respectively. The moving mold 2 covers the elastic element 4. In this embodiment, the elastic element 4 is a spring.

[0030] See Figures 1-3 The ejector rod 31 has an air passage 313 and an air passage 314. The air passage 313 and the air passage 314 are located on both sides of the piston cavity 311. The air passage 313 has an inlet 3131 and an outlet 3132. The inlet 3131 is located on the side of the outlet 3132 away from the stationary mold 1, and both the inlet 3131 and the outlet 3132 are connected to the piston cavity 311. The air passage 314 has an inlet 3141 and an outlet 3142. The inlet 3141 is located on the side of the outlet 3142 away from the stationary mold 1, and the outlet 3142 is located on the side of the outlet 3132 away from the stationary mold 1. Both the inlet 3141 and the outlet 3142 are connected to the piston cavity 311.

[0031] See Figures 1-3 The plug 33 includes a sliding part 331 and a limiting part 332. The sliding part 331 is slidably connected to the piston chamber 311. The sliding part 331 is located at the air outlet 312 and slides closer to or away from the stationary mold 1. A groove 3311 is provided on the outer peripheral wall of the sliding part 331. The groove 3311 is located on the side of the outlet 1 3132 away from the stationary mold 1 and communicates with the outlet 2 3142. A guide surface 5 is formed on the inner wall of the groove 3311 away from the stationary mold 1. The guide surface 5 is inclined towards the air passage 2 314 in the direction of the connecting rod 32. A slider 6 is slidably connected in the outlet 2 3142. The slider 6 extends into the groove 3311 and slides closer to or away from the sliding part 331.

[0032] See Figures 1-3 An elastic element 7 is installed on the push rod 31. The elastic element 7 is located inside the air passage 314 and between the slider 6 and the inner wall of the air passage 314. The two ends of the elastic element 7 and the slider 6 are fixedly connected to the push rod 31. In this embodiment, the elastic element 7 is a spring.

[0033] See Figures 1-3The limiting part 332 is fixed to the side of the sliding part 331 near the connecting rod 32, and the limiting part 332 is slidably connected in the limiting groove 3221. An elastic element 38 is installed on the extension part 322. The elastic element 38 is located in the limiting groove 3221 and between the limiting part 332 and the bottom of the limiting groove 3221. The elastic element 38 abuts against the limiting part 332. When the elastic element 2 7 and the elastic element 38 are in their natural state, the sliding part 331 covers the air outlet 312 and the outlet 1 3132, and the slider 6 abuts against the guide surface 5. The limiting part 332 abuts against the inner wall of the limiting groove 3221, thereby ensuring that the plug 33 moves smoothly and reducing the situation where the plug 33 is stuck due to being squeezed on one side.

[0034] The implementation principle of an injection mold that can improve the surface quality of injection molded parts according to an embodiment of this application is as follows:

[0035] During injection molding, the vent 312 is covered by the plug 33 to prevent liquid material from entering the vent 312 and causing injection defects such as bumps on the surface of the injection molded part, thereby improving the surface quality of the injection molded part.

[0036] When the push plate pushes the connecting rod 32 to move closer to the stationary mold 1, the elastic element 4 is compressed due to the ejector rod 31 abutting against the injection molded part, buffering the impact force between the ejector pin 3 and the injection molded part, reducing hard contact damage. At the same time, the air pressure in the piston chamber 311 increases, pushing the slider 6 to move away from the air passage 314. The slider 6 presses against the guide surface 5, pushing the sliding part 331 to overcome the elastic force of the elastic element 8 and move away from the injection molded part, exposing the outlet 3132. As the connecting rod 32 continues to move forward, the gas in the piston chamber 311 is discharged from the vent 312 through the outlet 3132. The gas blows open the contact surface between the injection molded part and the moving mold 2, reducing the suction force and making the ejection smoother. This allows the ejector rod 31 to eject the injection molded part with less force, resulting in shallower ejector pin 3 marks on the ejected injection molded part, ensuring the surface smoothness of the injection molded part and improving the surface quality of the injection molded part.

[0037] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An injection mold for improving the surface quality of injection molded parts, comprising a stationary mold (1), a moving mold (2), and ejector pins (3) disposed on the moving mold (2), characterized in that: The ejector pin (3) includes an ejector rod (31) disposed on the moving mold (2) and a connecting rod (32) slidably connected to the ejector rod (31). The connecting rod (32) is located on the side of the ejector rod (31) away from the stationary mold (1). The connecting rod (32) is used to be mounted on the push plate. A piston cavity (311) is provided on the ejector rod (31). An air outlet (312) is provided on the end face of the ejector rod (31) near the stationary mold (1). The air outlet (312) communicates with the piston cavity (311). The connecting rod (32) extends into the piston cavity (311) and slides closer to or away from the stationary mold (1). An elastic element (4) is provided between the ejector rod (31) and the connecting rod (32).

2. The injection mold for improving the surface quality of injection molded parts according to claim 1, characterized in that: The ejector pin (3) also includes a plug (33) slidably connected to the piston cavity (311). The plug (33) is located at the air outlet (312) and slides closer to or further away from the stationary mold (1). The ejector pin (31) has an air passage one (313) and an air passage two (314). The air passage one (313) has an inlet one (3131) and an outlet one (3132). The inlet one (3131) is located at the outlet one (3132). 2) On the side away from the stationary mold (1), the first inlet (3131) and the first outlet (3132) are both connected to the piston chamber (311). The second air passage (314) is provided with the second inlet (3141) and the second outlet (3142). The second inlet (3141) is located on the side of the second outlet (3142) away from the stationary mold (1). The second inlet (3141) and the second outlet (3142) are both connected to the piston chamber (311). The plug (33) is provided with a guide surface (5), which is inclined toward the air passage two (314) in the direction of the connecting rod (32). A slider (6) is slidably connected in the outlet two (3142). An elastic element three (8) is provided on the connecting rod (32). The elastic element three (8) abuts against the plug (33), so that the plug (33) covers the air outlet (312) and the outlet one (3132), and the guide surface (5) abuts against the slider (6).

3. The injection mold for improving the surface quality of injection molded parts according to claim 2, characterized in that: The plug (33) includes a sliding part (331) slidably connected to the piston chamber (311) and a limiting part (332) provided on the sliding part (331). The guide surface (5) is provided on the limiting part (332). The limiting part (332) is located on the side of the sliding part (331) close to the connecting rod (32). A limiting groove (3221) is provided on the connecting rod (32). The limiting part (332) is slidably connected to the limiting groove (3221).

4. The injection mold for improving the surface quality of injection molded parts according to claim 2, characterized in that: The top rod (31) is provided with an elastic element two (7), which is located between the slider (6) and the inner wall of the air passage two (314). When the elastic element two (7) and the elastic element three (8) are in their natural state, the slider (6) abuts against the guide surface (5).

5. The injection mold for improving the surface quality of injection molded parts according to claim 1, characterized in that: The connecting rod (32) includes a mounting part (321) and an extension part (322) provided on the mounting part (321). The mounting part (321) is used to be mounted on the push plate. The extension part (322) extends into the piston chamber (311). The elastic element (4) is sleeved on the outside of the extension part (322) and located between the push rod (31) and the mounting part (321). The moving mold (2) covers the elastic element (4).

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