Pusher structure for a mold

Abstract

The application provides a pushing structure of a mold, and belongs to the technical field of molds. The pushing structure of the mold solves the problems of poor moving stability of a top rod and high maintenance cost of the pushing structure. The pushing structure of the mold comprises a sliding base with a pouring runner, a top rod capable of extending into the pouring runner, a guide sleeve connected to the sliding base, a moving block embedded in the guide sleeve and abutting against the inner wall of the guide sleeve, the top rod being arranged on the moving block, a long slot being formed in the inner wall of the guide sleeve and extending through the inner wall in the radial direction and having a strip shape, a positioning pin being arranged in the long slot and used for positioning the moving block and the top rod, a first reset spring being arranged in the guide sleeve and used for elastically abutting against the moving block, and the positioning pin always having a tendency to drive the top rod to move away from the pouring runner along the long slot. The pushing structure of the mold has the advantages of improving the moving stability of the top rod and reducing the maintenance cost of the pushing structure.

Description

Technical Field

[0001] This invention belongs to the field of mold technology and relates to a push-out structure for a mold. Background Technology

[0002] Injection molds are the most commonly used molding dies in the production of thermoplastic parts. They mainly consist of a fixed mold, a moving mold, and a slide connected to the moving mold. A cavity is formed between the fixed mold, moving mold, and slide. A gating channel connecting to the cavity is opened on the side of the slide that is against the fixed mold. A guide rod is connected to the fixed mold and obliquely passes through the slide. During injection, the molten plastic flows into the cavity through the gating channel. After injection, the molten plastic remaining in the gating channel forms injection waste attached to the workpiece. When the mold opens, the moving mold moves relative to the fixed mold, and the guide rod drives the slide to move relative to the moving mold, separating the injection waste from the workpiece in the cavity. However, the separated injection waste remains in the gating channel and must be removed by the operator using appropriate tools.

[0003] In existing technology, to facilitate the removal of injection waste from the gating system, ejector pins that extend into the gating system towards the fixed mold are typically added to the bottom of the slide block. For example, Chinese patent literature discloses a sliding block submersible injection structure for injection molds (application number: 202020820475.6). As shown in the accompanying drawings of this document, the ejector pin is a slender rod. Therefore, when it is necessary to push the injection waste, a pushing force must be applied to one end of the ejector pin so that the other end of the ejector pin can extend into the gating system towards the fixed mold. However, the slide block is usually located between the upper and lower molds. If the ejector pin in this document is used to push the injection waste, it is foreseeable that the ejector pin needs to pass through the moving mold. Therefore, the length of the ejector pin needs to be set to be relatively long, and using a longer ejector pin will reduce the stability of the ejector pin's movement. Given the problem of low movement stability caused by excessively long ejector pins, a solution readily conceived by those skilled in the art is to adopt a segmented ejector pin structure. This improves the movement stability of the ejector pins by shortening the distance each ejector pin needs to move. However, this approach increases the maintenance cost of the ejector structure because each ejector pin segment interacts with each other, and the wear of each segment is uncontrollable. Therefore, once an ejector pin wears out, all ejector pins need to be replaced promptly, which undoubtedly increases the maintenance cost of the ejector structure. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned problems in the prior art by proposing a push-pull structure for a mold, which solves the technical problem of how to improve the stability of the push-pull movement while reducing the maintenance cost of the push-pull structure.

[0005] The objective of this invention can be achieved through the following technical solution: a push-out structure for a mold, the mold including a slide with a gating channel, the push-out structure including a push rod that can extend into the gating channel, characterized in that the push-out structure further includes a guide sleeve connecting the slide, the guide sleeve having a movable block embedded therein that abuts against its inner wall, the push rod passing through the movable block, the inner wall of the guide sleeve having an elongated hole that runs radially through it and is elongated in shape, the elongated hole having a positioning pin for positioning the movable block and the push rod passing through it, the guide sleeve having a first return spring that elastically abuts against the movable block, and the positioning pin always having a tendency to drive the push rod to move away from the gating channel along the elongated hole.

[0006] This application connects the guide sleeve to the slide block to ensure the positional relationship between the guide sleeve and the pouring channel. A positioning pin positions the ejector rod on a movable block that abuts against the inner wall of the guide sleeve. The movable block replaces the ejector rod in contact with the inner wall of the guide sleeve. When the ejector rod moves, this structure prevents wear caused by friction between the ejector rod and the inner wall of the guide sleeve. Since the positioning pin moves along the elongated hole, the movable block moves along the length of the elongated hole with the positioning pin. The elongated hole clearly defines the ejector rod's pushing stroke and prevents rotation of the movable block during movement. Therefore, even if the ejector rod moves away from the pouring channel through the force of the first return spring, this application prevents the ejector rod from wobbling due to the force of the first return spring by having the first return spring rest against the movable block, allowing the ejector rod to return to its initial position along the elongated hole. In other words, this application improves the movement stability of the ejector rod through the synergistic effect of the positioning pin and the movable block, and makes the wear of the ejector rod controllable. When maintaining the jacking structure, the locating pin is inserted into an elongated hole that radially penetrates the inner wall of the guide sleeve. Therefore, the locating pin can be removed from the outside of the guide sleeve. The movable block and the ejector rod are positioned using the locating pin, which is embedded within the guide sleeve. Once the operator removes the locating pin from the outer wall of the guide sleeve, the movable block and ejector rod can be easily removed from the guide sleeve, and the movable block can be replaced. Considering the maintenance cost of the jacking structure, the ejector rod requires a jacking force applied to one end to push the injection waste through the other end, indicating a high requirement for coaxiality. The movable block, on the other hand, only needs to be in contact with the inner wall of the guide sleeve. It is evident that the manufacturing cost of the ejector rod is much higher than that of the movable block. This application, by rationally designing a structure to guide the ejector rod, ensures the movement stability of the ejector rod simply by replacing the movable block, thereby improving the movement stability of the ejector rod and reducing the maintenance cost of the jacking structure.

[0007] In the aforementioned mold ejector structure, there are two elongated holes. The locating pin passes through the moving block and the ejector rod, with both ends of the locating pin located within the two elongated holes. When the ejector rod moves, the locating pin moves simultaneously along the two elongated holes, minimizing the rotation of the moving block and improving the stability of the ejector rod's movement. Because both ends of the locating pin are located within the two elongated holes, when removing the locating pin, the end of the locating pin can be tapped within one elongated hole, causing the locating pin to dislodge from the other elongated hole, thus improving the ease of replacing the moving block.

[0008] In the aforementioned mold ejector structure, the ejector rod has a rod portion passing through the moving block and a first pressure-bearing portion for bearing the thrust. The first return spring is sleeved on the rod portion, and the first pressure-bearing portion is located at one end of the rod portion, with a diameter larger than that of the rod portion. When the ejector rod needs to push the injection molding waste, the thrust is applied to the first pressure-bearing portion, causing the rod portion to drive the moving block to move against the spring force. Because the diameter of the first pressure-bearing portion is larger than that of the rod portion, this structure increases the contact area between the first pressure-bearing portion and the component applying the thrust, thereby improving the movement stability of the ejector rod.

[0009] In the aforementioned ejector structure of the mold, one end of the ejector pin is fitted with a sprue sleeve positioned on the slide block. The inner wall of the sprue sleeve has a guide section that abuts against the pin and a connecting section that connects to the gating channel. The connecting section is connected to the guide section, and the diameter of the connecting section gradually increases from the guide section to the gating channel. Because the connecting section is connected to the gating channel, some of the molten plastic flowing through the gating channel will flow into the connecting section. Thanks to the tapered hole structure of the connecting section, which is larger at the top and smaller at the bottom, injection waste material will also be retained in the connecting section during demolding. When the ejector pin pushes the injection waste material, the injection waste material will move along the hole wall of the connecting section, and the wall surface will rub against the ejector pin and the connecting section. This structure improves the movement stability of the ejector pin by utilizing the injection waste material.

[0010] In the aforementioned mold ejector structure, the ejector structure also includes an auxiliary rod that passes through the slide block and is used to eject the injection waste. The distance from the auxiliary rod to the gating channel is less than the distance from the ejector pin to the gating channel. The auxiliary rod, together with the ejector pin, can eject the injection waste, reducing the moving resistance of the ejector pin and improving its moving stability. By setting different ejector distances, the actual distance the auxiliary rod needs to move is reduced, that is, the moving stroke of the auxiliary rod is shortened to improve its moving stability.

[0011] In the aforementioned ejector structure of the mold, the ejector rod has a first ejector surface for ejecting the injection waste. The first ejector surface has a V-shaped notch extending to the wall surface. The auxiliary rod also has a second ejector surface for ejecting the injection waste. The second ejector surface has a conical ejector head whose diameter gradually decreases towards the gating channel. Because the ejector rod has a notch, the molten plastic flowing through the gating channel fills the notch. When the ejector rod ejects the injection waste, the injection waste is engaged with one end of the ejector rod through the notch. This structure minimizes the wobbling of the injection waste during ejection, thereby improving the ejector rod's ejection stability. When the ejector head is pushed, the injection waste is fitted onto the auxiliary rod during mold opening. This serves two purposes: firstly, the auxiliary rod assists the ejector rod in improving its ejection stability; secondly, it prevents the injection waste from falling back onto the mold after being injected into the gating channel.

[0012] In the aforementioned mold ejector structure, the slide block also has a first branch connecting the gating channel and a mounting hole. The gating sleeve includes a flange head and a main body embedded in the first branch. The guide sleeve abuts against the flange head to position the flange head within the mounting hole. The flange head is provided with a positioning pin embedded in the wall of the mounting hole. Because the ejector rod passes through the gating sleeve into the first branch, the flange head ensures a fixed length of the main body extending into the first branch. The positioning pin prevents the gating sleeve from rotating, thereby reducing unnecessary friction between the ejector rod and the gating sleeve and improving the movement stability of the ejector rod.

[0013] In the aforementioned mold push-up structure, the slide block also has a second branch connected to the gating channel. The auxiliary rod passes through the second branch. The push-up structure also includes an auxiliary sleeve connected to the slide block. The auxiliary sleeve abuts against the guide sleeve, and a slider slidably connected to it is embedded in the auxiliary sleeve. The auxiliary rod is positioned on the slider and is fitted with a second return spring at both ends that elastically abuts against the slider and the slide block respectively, ensuring that the auxiliary rod always has a tendency to move back. Because the auxiliary rod passes through the first branch, this structure allows the molten plastic flowing through the gating channel to easily flow to one end of the auxiliary rod. Furthermore, the gating channel guides the movement of the auxiliary rod. The auxiliary rod, through the second return spring, applies elastic force to the slider to drive the auxiliary rod back, while the slider moves along the inner wall of the auxiliary sleeve. This improves the stability of the auxiliary rod's movement, reduces wear on the auxiliary rod, and lowers the cost of the push-up structure.

[0014] In the aforementioned push-pull structure of the mold, the mold also includes a moving mold. The slide block is slidably connected to the moving mold, and a relief groove is provided on the moving mold. The first pressure-bearing part is located in the relief groove, and the auxiliary rod has a second pressure-bearing part located in the relief groove. Two push rods are provided on the moving mold, which can extend into the bottom of the relief groove and push the first pressure-bearing part and the second pressure-bearing part respectively. Because the two push rods apply the pushing force to the first pressure-bearing part and the second pressure-bearing part respectively, by placing both the first pressure-bearing part and the second pressure-bearing part in the relief groove, the length of the two push rods extending into the mold is shortened, thereby improving the movement stability of the push rods. This improves the stability of the pushing force of the push rods on the first pressure-bearing part and the second pressure-bearing part, thereby further improving the movement stability of the push rod and the auxiliary rod, that is, improving the push-pull stability of the push-pull structure.

[0015] Compared with the prior art, the push-pull structure of the mold provided by the present invention has the following advantages:

[0016] 1. By setting a guide sleeve and using a positioning pin inserted in the elongated hole to position the push rod on the moving block, when the push rod moves, the moving block replaces the push rod and moves along the elongated hole against the inner wall of the guide sleeve, preventing the push rod from rotating during movement. This facilitates the removal of the positioning pin and also limits the travel of the push rod, thereby ensuring the stability of the push rod movement and reducing the cost of the jacking structure.

[0017] 2. The friction between the ejector pin and the slide block is reduced by using the injection sleeve, and the movement stability of the ejector pin is improved by using the injection waste formed inside the injection sleeve through its structure.

[0018] 3. The injection molding waste is pushed by the coordinated action of the push rod and the auxiliary rod. By shortening the distance between the auxiliary rod and the gating channel, the actual stroke required for the auxiliary rod to move is shortened, thereby improving the movement stability of the auxiliary rod. Attached Figure Description

[0019] Figure 1 This is a sectional view of the mold (structures on the mold that are not relevant to this case are omitted).

[0020] Figure 2 yes Figure 1 A magnified view of a portion of the image.

[0021] Figure 3 This is a schematic diagram of the overall structure of the jacking structure.

[0022] Figure 4 yes Figure 3 A sectional view.

[0023] Figure 5 yes Figure 3 Exploded view.

[0024] In the diagram, 1. Ejector rod; 101. Rod section; 102. First pressure bearing section; 103. First ejector surface; 104. Notch; 2. Guide sleeve; 21. Elongated hole; 3. Moving block; 4. Positioning pin; 5. First return spring; 6. Slide block; 61. Sprue; 62. First branch; 63. Mounting hole; 64. Second branch; 7. Sprue sleeve; 71. Guide section; 72. Connecting section; 73. Flange head; 74. Main body; 8. Auxiliary rod; 81. Second ejector surface; 82. Ejector head; 83. Second pressure bearing section; 9. Positioning pin; 10. Auxiliary sleeve; 11. Slider; 12. Second return spring; 13. Moving mold; 131. Relief groove; 14. Ejector rod; 15. Fixed mold; 16. Cavity. Detailed Implementation

[0025] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0026] like Figure 1 and Figure 2 As shown, the ejector structure of this mold includes a fixed mold 15, a moving mold 13, and a slide block 6 slidably connected to the moving mold 13. A cavity 16 is formed between the fixed mold 15, the moving mold 13, and the slide block 6. A gating channel 61 is provided on the side of the slide block 6 that is against the fixed mold 15. The ejector structure includes an ejector rod 1 for extending into the gating channel 61 and an auxiliary rod 8 for extending into the gating channel 61. The distance from the auxiliary rod 8 to the gating channel 61 is less than the distance from the ejector rod 1 to the gating channel 61. A guide sleeve 2, which is elongated, and an auxiliary sleeve 10 are provided between the moving mold 13 and the slide block 6, with the auxiliary sleeve 10 abutting against the guide sleeve 2.

[0027] like Figures 2-4 As shown, the inner wall of the guide sleeve 2 is cylindrical, and a ring-shaped moving block 3 is embedded therein, which abuts against the inner wall. The push rod 1 has a rod portion 101 passing through the moving block 3 and a first pressure-bearing portion 102 for bearing the thrust. The first pressure-bearing portion 102 is located at one end of the rod portion 101, and the diameter of the first pressure-bearing portion 102 is larger than the diameter of the rod portion 101. The inner wall of the guide sleeve 2 has two radially penetrating, elongated holes 21, which are arranged opposite each other. A positioning pin 4 of the positioning rod portion 101 is transversely inserted on the moving block 3. The two ends of the positioning pin 4 are respectively located in the two elongated holes 21. A first return spring 5 is sleeved on the rod portion 101. The two ends of the first return spring 5 abut against the moving block 3 and the guide sleeve 2 respectively, so that the positioning pin 4 always has the tendency to drive the push rod 1 to move away from the pouring channel 61 along the elongated holes 21.

[0028] like Figures 3-5As shown, a casting sleeve 7 is fitted onto the end of the rod 101 away from the first pressure-bearing part 102. The inner wall of the casting sleeve 7 has a guide section 71 that abuts against the rod 101 and a connecting section 72 that connects to the casting channel 61. The connecting section 72 is connected to the guide section 71, and the diameter of the connecting section 72 gradually increases from the guide section 71 to the casting channel 61. The slide 6 also has a first branch 62 that connects to the casting channel 61 and a mounting hole 63. The casting sleeve 7 includes a flange head 73 and a main body 74 embedded in the first branch 62. The guide sleeve 2 abuts against the flange head 73 to position the flange head 73 in the mounting hole 63. A groove extending to the orifice is provided on the wall of the mounting hole 63, and a positioning post 9 embedded in the groove is provided on the side wall of the flange head 73.

[0029] The push rod 1 has a first push surface 103 for pushing the injection waste. The first push surface 103 has a V-shaped notch 104 extending to the wall. The auxiliary rod 8 also has a second push surface 81 for pushing the injection waste. The second push surface 81 has a cone-shaped push head 82 with a diameter that gradually decreases toward the pouring channel 61.

[0030] like Figure 2 As shown, the slide block 6 also has a second branch 64 that connects to the pouring channel 61. The auxiliary rod 8 passes through the second branch 64, and the push head 82 is located in the second branch 64. The push structure also includes an auxiliary sleeve 10 that connects to the slide block 6. The auxiliary sleeve 10 is fitted with a slider 11 that abuts against its inner wall. The inner wall of the auxiliary sleeve 10 has two through and elongated sliding holes. The auxiliary rod 8 passes through the slider 11, and a sliding pin for positioning the slider 11 passes through the auxiliary rod 8. The two ends of the sliding pin are located in the two sliding holes respectively. A second return spring 12 is sleeved on the auxiliary rod 8, with its two ends abutting against the block and the slide block 6 respectively, so that the auxiliary rod 8 always has a tendency to move back.

[0031] like Figure 1 and Figure 2 As shown, the moving mold 13 has a relief groove 131, the first pressure bearing part 102 is located in the relief groove 131, the auxiliary rod 8 has a second pressure bearing part 83 located in the relief groove 131, and two push rods 14 are provided on the moving mold 13, which can extend into the bottom of the relief groove 131 and push the first pressure bearing part 102 and the second pressure bearing part 83 respectively.

[0032] When the injection molding waste is pushed, the two push rods 14 push the push rod 1 and the auxiliary rod 8 respectively, causing the moving block 3 to overcome the elasticity of the first return spring 5 and move along the elongated hole 21 and against the inner wall of the guide sleeve 2 along the sliding hole. This causes the slider 11 to overcome the elasticity of the second return spring 12 and move against the inner wall of the auxiliary sleeve 10. The first pushing surface 103 and the second pushing surface 81 together push the injection molding waste towards the ejection channel 61. When the positioning pin 4 abuts against one end of the elongated hole 21, the push rod 1 stops moving. When the sliding pin abuts against one end of the sliding hole, the auxiliary rod 8 stops moving. After the operator removes the injection molding waste, the two push rods 14 move back, causing the moving block 3 to move along the elongated hole 21 and drive the push rod 1 back to its original position under the elastic force of the first return spring 5. The slider 11 also moves along the sliding hole and drives the auxiliary rod 8 back to its original position under the elastic force of the second return spring 12. When the moving block 3 and the slider 11 are worn, the operator only needs to remove the positioning pin 4 from the elongated hole 21 to make the moving block 3 disengage from the guide sleeve 2, and remove the sliding pin from the sliding hole to make the slider 11 disengage from the auxiliary sleeve 10.

[0033] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

[0034] Although this document frequently uses terms such as ejector pin 1, rod 101, first pressure bearing part 102, first ejector surface 103, notch 104, guide sleeve 2, elongated hole 21, moving block 3, positioning pin 4, first return spring 5, slide block 6, gating channel 61, first branch 62, mounting hole 63, second branch 64, gating sleeve 7, guide section 71, connecting section 72, flange head 73, main body 74, auxiliary rod 8, second ejector surface 81, ejector head 82, second pressure bearing part 83, positioning pin 9, auxiliary sleeve 10, slider 11, second return spring 12, moving mold 13, relief groove 131, ejector pin 14, fixed mold 15, cavity 16, etc., the possibility of using other terms is not excluded. The use of these terms is merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention.

Claims

1. A push-pull structure for a mold, the mold including a slide (6) having a gating channel (61), the push-pull structure including a push rod (1) capable of extending into the gating channel (61), characterized in that, The push structure also includes a guide sleeve (2) connecting the slide (6). The guide sleeve (2) is fitted with a moving block (3) that abuts against its inner wall. The inner wall of the guide sleeve (2) is cylindrical. The moving block (3) is annular. The push rod (1) passes through the moving block (3). The inner wall of the guide sleeve (2) has a long hole (21) that runs radially through it. The long hole (21) is fitted with a positioning pin (4) for positioning the moving block (3) and the push rod (1). The guide sleeve (2) has a first return spring (5) that elastically abuts against the moving block (3), and the positioning pin (4) always tends to drive the push rod (1) to move away from the pouring channel (61) along the long hole (21). The upper end of the guide sleeve (2) has a blocking part that protrudes from the inner wall of the guide sleeve (2) and is used to block the first return spring (5). There is a gap between the blocking part and the push rod (1).

2. The push-pull structure of a mold according to claim 1, characterized in that, The number of the elongated holes (21) is two, and the positioning pin (4) passes through the moving block (3) and the top rod (1), with the two ends of the positioning pin (4) located in the two elongated holes (21) respectively.

3. The push-pull structure of a mold according to claim 1 or 2, characterized in that, The top rod (1) has a rod portion (101) that passes through the movable block (3) and a first pressure bearing portion (102) for bearing thrust. The first return spring (5) is sleeved on the rod portion (101). The first pressure bearing portion (102) is located at one end of the rod portion (101), and the diameter of the first pressure bearing portion (102) is larger than the diameter of the rod portion (101).

4. The push-pull structure of a mold according to claim 3, characterized in that, One end of the top rod (1) is fitted with a casting sleeve (7) positioned on the slide (6). The inner wall of the casting sleeve (7) has a guide section (71) that abuts against the rod part (101) and a connecting section (72) that connects to the casting channel (61). The connecting section (72) is connected to the guide section (71), and the aperture of the connecting section (72) gradually increases from the guide section (71) to the casting channel (61).

5. The push-pull structure of a mold according to claim 4, characterized in that, The pusher structure also includes an auxiliary rod (8) that passes through the slide (6) and is used to push the injection waste. The distance from the auxiliary rod (8) to the gating channel (61) is less than the distance from the pusher (1) to the gating channel (61).

6. The push-pull structure of a mold according to claim 5, characterized in that, The push rod (1) has a first push surface (103) for pushing the injection waste, and a V-shaped notch (104) extending to the wall surface is provided on the first push surface (103). The auxiliary rod (8) also has a second push surface (81) for pushing the injection waste, and a push head (82) that is conical and gradually decreases in diameter toward the pouring channel (61) is provided on the second push surface (81).

7. The push-pull structure of a mold according to claim 4, characterized in that, The slide (6) also has a first branch (62) connecting the pouring channel (61) and a mounting hole (63). The pouring sleeve (7) includes a flange (73) and a main body (74) embedded in the first branch (62). The guide sleeve (2) abuts against the flange (73) to position the flange (73) in the mounting hole (63). The flange (73) is provided with a positioning post (9) embedded in the wall of the mounting hole (63).

8. The push-pull structure of a mold according to claim 5, characterized in that, The slide (6) also has a second branch (64) that connects to the pouring channel (61). The auxiliary rod (8) passes through the second branch (64). The pushing structure also includes an auxiliary sleeve (10) that connects to the slide (6). The auxiliary sleeve (10) abuts against the guide sleeve (2), and a slider (11) that is slidably connected to the auxiliary sleeve (10) is embedded in the auxiliary sleeve (10). The auxiliary rod (8) is positioned on the slider (11), and a second return spring (12) is sleeved on which both ends elastically abut against the slider (11) and the slide (6) respectively, so that the auxiliary rod (8) always has a tendency to move back.

9. The push-pull structure of a mold according to claim 5, characterized in that, The mold also includes a moving mold (13), the slide block (6) is slidably connected to the moving mold (13), the moving mold (13) is provided with a relief groove (131), the first pressure bearing part (102) is located in the relief groove (131), the auxiliary rod (8) has a second pressure bearing part (83) located in the relief groove (131), and two push rods (14) are provided on the moving mold (13) that can extend from the bottom of the relief groove (131) and push the first pressure bearing part (102) and the second pressure bearing part (83) respectively.

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