Automatic ejection guide mechanism of plastic part

Abstract

The invention discloses an automatic ejection guide mechanism for plastic parts, which relates to the technical field of plastic part processing and comprises a guide outer cylinder fixed on one side of a male die. The pushing assembly movably penetrates through the axis of the guide outer cylinder and stably moves through self-adaptive expansion; the anti-drag component is arranged in the guide outer barrel, driven by the oil cylinder and capable of collecting and releasing lubricating oil in a self-adaptive mode; and the sealing assembly is arranged in the guide outer cylinder and is self-adaptively deformed through gas pressure change. According to the invention, the movable ejector pin has the characteristics of being expandable during forward pushing and retracting during backward pushing, so that even if the movable ejector pin and the guide outer cylinder are abraded, the movable ejector pin can adapt to the size of a gap between the movable ejector pin and the guide outer cylinder during forward pushing, the movable ejector pin is expanded firstly, the outer wall of the movable ejector pin is kept in a state of being always attached to the inner wall of the guide outer cylinder, and then the movable ejector pin is pushed forward; the movable ejector pin is always limited by the guide outer cylinder to stably move in the forward pushing process, and the movable ejector pin is not prone to bending or breaking.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of plastic part processing, in particular to an automatic ejection guide mechanism for plastic parts. BACKGROUND

[0002] Plastic parts are products with specific shapes, sizes and functions made of plastic raw materials through molding processes such as injection molding, extrusion, blow molding and die pressing. Common ones are polyethylene, polypropylene, polyvinyl chloride, etc. Due to their light weight, easy processing and low cost, they are widely used in various fields. The processing of plastic parts usually relies on injection molding and extrusion molding processes. Taking injection molding as an example, the plastic raw material is first heated and melted, then injected into the mold cavity by the screw of the injection molding machine, and the desired shape of the plastic part is formed after cooling and solidification. However, after the plastic part is cooled and formed in the mold, due to the friction and adsorption force between the plastic part and the inner wall of the mold, the plastic part cannot be separated from the mold, and generally needs to be forcibly pushed out by a ejector pin.

[0003] The ejector pin will move smoothly along the inside of the guide cylinder and quickly push the plastic part away from the mold. Through reasonable position distribution, the ejector pin can apply uniform pushing force to the plastic part, so that the plastic part is not easy to break or deform when pushed out.

[0004] Although the guide cylinder can provide smooth support for the movement of the ejector pin, long-term friction between the ejector pin and the guide cylinder will cause wear and tear inside the ejector pin or the guide cylinder, and the gap between them will become larger and larger. Even if the movement trajectory of the ejector pin only appears slight deviation, under the action of the bidirectional hard extrusion force of the ejector pin and the plastic part, the ejector pin is also easy to bend or even break. At present, one of the common methods to deal with the wear and tear of the ejector pin and the guide cylinder is to regularly apply a sufficient amount of lubricating oil to the surface of the ejector pin to reduce the friction between the two. However, the above treatment method still has the following problems: 1. Under the frequent stretching and contraction of the ejector pin, the loss of lubricating oil is very large, so timely replenishment of lubricating oil is a necessary operation for daily maintenance of the equipment, and each time the lubricating oil is applied, the machine needs to be stopped, which to some extent reduces the processing progress of the plastic part; 2. Lubricating oil can only temporarily alleviate the friction damage between the ejector pin and the guide cylinder. Once wear occurs (causing the ejector pin diameter to decrease and the guide cylinder inner diameter to increase, resulting in a larger gap between them), a series of adverse effects will occur, such as unstable ejector pin movement, uneven stress between the ejector pin and the plastic part causing the ejector pin to bend or the surface of the plastic part to be damaged, and fluid overflowing from the gap during injection molding. This increases the defect rate of the finished plastic parts. Therefore, it is necessary to pay close attention to the wear condition of the ejector pin and the guide cylinder at all times. However, in reality, whether the two have suffered serious wear is generally judged by whether the above-mentioned adverse effects have occurred. This makes the maintenance and replacement of the ejector pin and the guide cylinder very passive, and it is difficult to reduce the risk of equipment damage and non-conforming plastic parts.

[0005] To address the aforementioned issues, there is an urgent need for innovative design based on the existing automatic ejection guide mechanism for plastic parts. Summary of the Invention

[0006] The present invention addresses the problem of overly simplistic solutions in existing technologies by providing a significantly different solution. Specifically, the present invention aims to provide an automatic ejection and guiding mechanism for plastic parts, thereby solving the problems mentioned in the background art, such as the passive nature of maintenance and replacement of ejector pins and guide cylinders, and the difficulty in reducing the risk of equipment damage and substandard plastic parts.

[0007] To achieve the above objectives, the present invention provides the following technical solution: an automatic ejection guide mechanism for plastic parts, comprising an injection mold, a punch fixed inside the injection mold, a hydraulic cylinder fixed on one side of the injection mold, and a disc fixed at the piston end of the hydraulic cylinder, and further comprising: A guide cylinder fixed to one side of the punch; The jacking assembly, which achieves stable movement through adaptive expansion at the axis of the guide outer cylinder, is active. A drag-reducing component installed inside the guide outer cylinder and driven by an oil cylinder to adaptively release and retract lubricating oil; A sealing assembly installed inside the guide outer cylinder that adapts to changes in gas pressure and deforms accordingly; The push assembly includes several sets of movable ejector pins arranged in equal proportions at the axis of the movable guide outer cylinder, ejector pin heads that are movablely inserted in the punch, and pioneer rods that are movablely inserted inside the movable ejector pins. The drag reduction component includes an oil-gas dual-pass chamber opened inside the guide outer cylinder, a piston ring sliding inside the oil-gas dual-pass chamber, and an oil pressure compensation chamber opened inside one end of the guide outer cylinder. The sealing assembly includes an air cavity formed inside the punch and a sealing rubber ring movably disposed inside one end of the air cavity.

[0008] Preferably, several sets of the movable ejector pins are arranged to form a hollow cylinder; The hollow cylinder is tightly wrapped outside the pioneer rod; Both ends of the hollow cylinder are sleeved with annular return springs.

[0009] Preferably, the pushing assembly further comprises a fixing member fixed on one side of the disc; A telescopic cylinder is movably inserted in one side of the fixing member; One end of the telescopic cylinder extends to the outside of the fixing member and is connected with one end of the movable ejector pin through a cross slide rail; The other end of the movable ejector pin is also connected with one end of the ejector pin head through a cross slide rail; A No. 2 spring is fixed between the inner wall of the fixing member and the other end of the telescopic cylinder, and the No. 2 spring movably sleeves the outside of the pioneer rod.

[0010] Preferably, one end of the pioneer rod penetrates through the middle of the telescopic cylinder and is fixedly connected with the inner wall of the fixing member; The other end of the pioneer rod is provided as a circumferential body with a beveled side edge; The inner wall of the movable ejector pin is provided with a bevel in the middle, which is adapted to the other end of the pioneer rod.

[0011] Preferably, the surface of the male die is provided with a circular groove; The ejector pin head is provided in a circular table shape, and the maximum diameter of the ejector pin head is consistent with the inner diameter of the circular groove.

[0012] Preferably, the drag-reducing component further comprises a plurality of groups of push rods fixed on one side of the fixing member at equal angles; One end of each group of the push rods movably penetrates through one end of the guide outer cylinder and is fixedly connected with one side of the piston ring; The size of the piston ring is adapted to the size of the oil and gas double-pass chamber The inside of the guide outer cylinder is provided with a pipe placement chamber; A plurality of groups of oil distribution pipes are fixed in the inside of the pipe placement chamber at equal proportions; The oil distribution pipe is composed of a long pipe and a plurality of groups of short pipes uniformly distributed on one side of the long pipe; The inside of one end of the oil and gas double-pass chamber is connected with the inside of one end of the long pipe through a pipeline close to the ejector pin head; One end of the short pipe extends to the outer wall of the movable ejector pin through the guide outer cylinder, and the short pipe is in close proximity to but not in contact with the outer wall of the movable ejector pin.

[0013] Preferably, the oil pressure compensation chamber is provided with a plurality of groups of oil distribution pipes; The inside of one end of the oil and gas double-pass chamber is connected with the inside of the oil pressure compensation chamber through a pipeline close to the ejector pin head; An oil supplement pipe is fixedly inserted into one end of the guide outer cylinder close to the ejector pin head; One end of the oil supplement pipe extends to the outside of the guide outer cylinder; The inside of the oil supplement pipe communicates with the inside of the oil pressure compensation chamber.

[0014] Preferably, the sealing assembly further comprises a blocking ring fixed inside the air cavity; The blocking ring and the sealing rubber ring are movably provided with a squeeze piston plate therebetween; The inner and outer diameters of the squeeze piston plate are consistent with the inner and outer diameters of the air cavity; The side of the sealing rubber ring extends to the outside of the air cavity and closely abuts the surface of the needle head; The inside of the air cavity communicates with the inside of the other end of the oil-gas double-pass chamber through a gas delivery pipe; The gas delivery pipe is provided with several groups in equal proportion.

[0015] Preferably, several groups of air pressure compensation chambers are arranged in equal proportion at the other end of the guide outer cylinder away from the needle head; The inside of the air pressure compensation chamber communicates with the inside of one end of the oil-gas double-pass chamber away from the needle head through a pipeline; The inside of the oil pressure compensation chamber and the air pressure compensation chamber are movably provided with a sealing plate; The sealing plate is fixed with a No. 1 spring between the inner wall of the guide outer cylinder.

[0016] Preferably, a gas supplement pipe is fixedly inserted at one end of the guide outer cylinder away from the needle head; One end of the gas supplement pipe extends to the outside of the guide outer cylinder; The inside of the gas supplement pipe communicates with the inside of the air pressure compensation chamber.

[0017] Compared with the prior art, the beneficial effects of the present application are: 1. When the movable ejector pin is pushed forward to eject the plastic part, the piston rings simultaneously squeeze the lubricating oil located inside the oil-gas dual-pass chamber. The lubricating oil enters the contact surface between the movable ejector pin and the guide cylinder through the oil distribution pipe, reducing the friction between the movable ejector pin and the guide cylinder during movement, thus preventing excessive wear. During the retraction of the movable ejector pin to its original position, the piston rings also return to their original position simultaneously. The internal pressure of the oil-gas dual-pass chamber near the ejector pin head decreases, and excess lubricating oil between the contact surface of the guide cylinder and the movable ejector pin is drawn out through the oil distribution pipe. The lubricant is drawn into the dual-channel oil and gas chamber. Compared to the existing method of manually applying lubricant periodically, this method offers several advantages. First, the excess lubricant can be recycled, significantly improving its utilization rate. Second, during the entire lubrication process, workers only need to periodically replenish the lubricant into the oil pressure compensation chamber via the oil replenishment pipe. Compared to the existing method of applying lubricant to the ejector pin, this method significantly reduces the number of manual lubricant replenishments and the frequency of lubrication. This reduces the number of times the equipment needs to be shut down for maintenance, lightening the workload for workers and improving the efficiency of plastic parts production.

[0018] 2. In this invention, the movable ejector pin's ability to expand when pushed forward and retract when pulled back allows it to adapt to the size of the gap between itself and the guide cylinder even when worn. It first expands to maintain contact between its outer wall and the inner wall of the guide cylinder before pushing forward. During this process, the movable ejector pin moves stably under the constraint of the guide cylinder, preventing it from bending or breaking. Furthermore, the replacement of the movable ejector pin and guide cylinder is no longer reactive, providing ample time for workers to replace worn parts. There is no need to constantly monitor wear or worry excessively about the risk of product defects caused by sudden wear of the movable ejector pin and guide cylinder. In short, even with severe wear, the movable ejector pin and guide cylinder can operate stably for a long time, during which time workers can replace them at any time. Furthermore, the movable ejector pin can retract first and then withdraw. When the movable ejector pin retracts, the gap between it and the outer guide cylinder increases, and there is no friction between the two. Compared with the existing ejector pins, which rub against the guide cylinder when moving back and forth, the movable ejector pin of this invention can significantly reduce the number of times it rubs against the outer guide cylinder, further extending the service life of the equipment. The replacement frequency of the movable ejector pin and the outer guide cylinder is also significantly reduced.

[0019] 3、The piston ring back position absorbs the excess lubricating oil, and the air inside the oil-gas double passage chamber far from the end of the ejector pin head is pushed to the air cavity by the piston ring, under the action of air pressure, the air is pushed into the piston plate and pushes the sealing rubber ring, so that the sealing rubber ring is deformed and tightly abuts against the surface of the ejector pin head, the sealing rubber ring and the movement track of the ejector pin head are opposite when the ejector pin head retreats, the two are pressed against each other, and the small gap between the ejector pin head and the convex die is filled with the sealing rubber ring, compared with the existing sealing ring filling gap, the sealing rubber ring and the ejector pin head generate a counter force by using the power driving of the push assembly retreat and the pressure change in the oil-gas double passage chamber, and then the deformation of the sealing rubber ring is more complete, and the filling effect of the gap is better, so that the fluid is not easy to overflow from the gap during injection, and the appearance neatness of the final product of the plastic part is effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is the first three-dimensional structure schematic diagram of the application.

[0021] Figure 2 It is the open mold state structure schematic diagram of the application.

[0022] Figure 3 It is the partial cross-section structure schematic diagram of the application.

[0023] Figure 4 It is the ejection state structure schematic diagram of the application.

[0024] Figure 5 It is the partial cross-section rear view structure schematic diagram of the application.

[0025] Figure 6 It is the partial cross-section structure schematic diagram of the application.

[0026] Figure 7 It is the guide outer cylinder structure schematic diagram of the application.

[0027] Figure 8 It is the guide outer cylinder cross-section structure schematic diagram of the application.

[0028] Figure 9 It is the partial cross-section structure schematic diagram of the application.

[0029] Figure 10 It is the oil pressure compensation chamber cross-section front view structure schematic diagram of the application.

[0030] Figure 11 It is the air pressure compensation chamber cross-section front view structure schematic diagram of the application.

[0031] Figure 12 It is the air cavity cross-section structure schematic diagram of the application.

[0032] Figure 13The cross-sectional structure schematic diagram of the sealing rubber ring of the application.

[0033] Figure 14 The cross-sectional structure schematic diagram of the fixing part of the application.

[0034] Figure 15 The schematic diagram of the movable ejector pin burst structure of the application.

[0035] Figure 16 The schematic diagram of the pioneer rod structure of the application.

[0036] Figure 17 The schematic diagram of the second spring structure of the application.

[0037] Figure 18 The schematic diagram of the enlarged structure of the A in the application. Figure 17

[0038] Figure 19 The schematic diagram of the ejector pin head structure of the application.

[0039] In the figure: 1, injection mold; 2, male die; 3, oil cylinder; 4, disc; 5, guide outer cylinder; 6, fixing part; 7, movable ejector pin; 8, push rod; 9, ejector pin head; 10, gas delivery pipe; 11, oil supplement pipe; 12, gas supplement pipe; 13, oil distribution pipe; 14, piston ring; 15, oil pressure compensation chamber; 16, gas pressure compensation chamber; 17, oil-gas double passage chamber; 18, pipe placement chamber; 19, gas chamber; 20, first spring; 21, sealing plate; 22, pioneer rod; 23, telescopic cylinder; 24, second spring; 25, annular reset spring; 26, blocking ring; 27, extrusion piston plate; 28, sealing rubber ring. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0041] Please refer to Figures 1 to 19 The application provides a technical solution: an automatic ejection guide mechanism for a plastic part, which comprises an injection mold 1, a male die 2 fixed in the injection mold 1, an oil cylinder 3 fixed on one side of the injection mold 1, and a disc 4 fixed at the piston end of the oil cylinder 3, and further comprises: a guide outer cylinder 5 fixed on one side of the male die 2; a movable push assembly penetrating the axis of the guide outer cylinder 5 and achieving stable movement through self-adapting expansion; ​The drag reduction component is arranged inside the guide outer cylinder 5 and driven by the oil cylinder 3 to adaptively collect and release lubricating oil; The sealing assembly is arranged inside the guide outer cylinder 5 and deforms adaptively through gas pressure change; In specific implementation, the guide outer cylinder 5, the pushing assembly, the drag reduction component and the sealing assembly can be installed with several groups at appropriate positions according to requirements, and the number and position of the above components in the drawings of the present application are only for reference, and the specific number and arrangement mode can be consistent with the prior art, which will not be described in detail here.

[0042] The pushing assembly comprises several groups of movable push pins 7 arranged in equal proportions through the axis of the guide outer cylinder 5, push pin heads 9 movably inserted into the punch 2, and pioneer rods 22 movably inserted into the movable push pins 7; The drag reduction component comprises an oil-gas double-pass cavity 17 opened inside the guide outer cylinder 5, a piston ring 14 sliding inside the oil-gas double-pass cavity 17, and an oil pressure compensation cavity 15 opened inside one end of the guide outer cylinder 5; The sealing assembly comprises a gas cavity 19 opened inside the punch 2 and a sealing rubber ring 28 movably arranged inside one end of the gas cavity 19.

[0043] The several groups of movable push pins 7 enclose a hollow cylinder; The hollow cylinder tightly wraps outside the pioneer rod 22; In specific implementation, when the pioneer rod 22 is pushed forward, the movable push pins 7 can be expanded quickly, and the close contact between the pioneer rod 22 and the inner wall of the movable push pins 7 also provides support for the movable push pins 7, so that the movable push pins 7 can maintain a horizontal state for expansion and contraction.

[0044] The hollow cylinder is sleeved with a ring-shaped reset spring 25 at both ends.

[0045] In specific implementation, the rebound of the ring-shaped reset spring 25 can drive the movable push pins 7 to retract, so that the movable push pins 7 no longer contact the guide outer cylinder 5 when retracted, thereby reducing the friction loss between the movable push pins 7 and the guide outer cylinder 5.

[0046] The pushing assembly further comprises a fixed part 6 fixed to one side of the disc 4; The fixed part 6 movably inserts a telescopic cylinder 23 on one side; One end of the telescopic cylinder 23 extends to the outside of the fixed part 6 and is connected to one end of the movable push pin 7 through a cross slide rail; In specific implementation, as shown in Figure 17 and Figure 18As shown, the cross slide rail is provided with multiple groups same as the number of the movable ejector pin 7, each group of cross slide rail corresponds to the position of each group of movable ejector pin 7, and the cross slide rail limits the movable ejector pin 7 when each group of movable ejector pin 7 expands and shrinks, so as to ensure that the movable ejector pin 7 is more stable when expanding and shrinking, and the cross slide rail can make the telescopic barrel 23 and the movable ejector pin 7 move forward and backward synchronously, which provides a key condition for the automatic backward movement of the movable ejector pin 7.

[0047] The other end of the movable ejector pin 7 is also connected with one end of the ejector head 9 through the cross slide rail. In specific implementation, as shown in the accompanying drawings, Figure 19 As shown, the cross slide rail can ensure the stability of the movement of the other end of the movable ejector pin 7, so that the movable ejector pin 7 can expand and shrink uniformly, and the movable ejector pin 7 will not affect the ejector head 9 when expanding and shrinking, and on the other hand, the cross slide rail can drive the ejector head 9 to move synchronously during the forward movement and backward movement of the movable ejector pin 7.

[0048] The second spring 24 is fixed between the inner wall of the fixed part 6 and the other end of the telescopic barrel 23, and the second spring 24 is movably sleeved outside the pioneer rod 22.

[0049] In specific implementation, the main function of the second spring 24 is to pull the telescopic barrel 23 by the rebounding pulling force of the second spring 24 when the fixed part 6 moves backward, so that the telescopic barrel 23 and the movable ejector pin 7 can also move backward.

[0050] One end of the pioneer rod 22 penetrates through the middle of the telescopic barrel 23 and is fixedly connected with the inner wall of the fixed part 6. The other end of the pioneer rod 22 is provided as a circumferential body with a beveled side. The inner wall of the movable ejector pin 7 is provided with a bevel matched with the other end of the pioneer rod 22.

[0051] In specific implementation, the pioneer rod 22 keeps a state of synchronous movement with the fixed part 6, and under the mutual extrusion of the bevel of the other end of the pioneer rod 22 and the bevel of the inner wall of the movable ejector pin 7, the movable ejector pin 7 can be expanded first and then moved forward, so as to ensure that the movable ejector pin 7 is always close to the inner wall of the guide outer barrel 5 during the forward movement, and the movement of the movable ejector pin 7 is more stable.

[0052] The surface of the punch 2 is provided with a circular groove; The ejector head 9 is provided in a circular table shape, and the maximum diameter of the ejector head 9 is consistent with the inner diameter of the circular groove.

[0053] In specific implementation, the circular groove provides a passing channel for the movement of the ejector head 9 and the movable ejector pin 7, as shown in the accompanying drawings, Figure 12As shown in the figure, when the ejector pin head 9 is withdrawn to the original position, one side of the ejector pin head 9 should be kept flush with the surface of the punch 2 to prevent the surface of the plastic part from being concave after molding, which is also the common sense known to those skilled in the art. In addition, the special design of the ejector pin head 9 can make the contact area between the ejector pin head 9 and the circular groove very small, effectively reducing the risk of friction damage between the two.

[0054] The drag reduction component also includes several groups of push rods 8 fixed at equal angles on one side of the fixed part 6; One end of the several groups of push rods 8 is movably connected to the other end of the guide outer cylinder 5 and one side of the piston ring 14; In specific implementation, when the push rod 8 moves with the fixed part 6, it can drive the piston ring 14 to move synchronously, thereby achieving the purpose of supplying oil when pushing forward and strengthening the sealing performance and recovering excess lubricating oil when withdrawing.

[0055] The size of the piston ring 14 is matched with the size of the oil-gas double-pass cavity 17.

[0056] In specific implementation, the piston ring 14 divides the oil-gas double-pass cavity 17 into two spaces, and the two spaces in the oil-gas double-pass cavity 17 are used for storing lubricating oil and gas respectively. By moving the piston ring 14 inside the oil-gas double-pass cavity 17, the pressure in the two spaces in the oil-gas double-pass cavity 17 is alternately reduced, thereby reducing the friction between the sealing rubber ring 28 and the ejector pin head 9 when supplying oil, reducing the resistance of the ejector pin head 9 when pushing forward, and preparing for the deformation of the sealing rubber ring 28 when recovering oil to fill the gap between the ejector pin head 9 and the circular groove.

[0057] The inside of the guide outer cylinder 5 is provided with a pipe placement cavity 18; Several groups of oil distribution pipes 13 are fixed inside the pipe placement cavity 18 in equal proportions; The oil distribution pipe 13 is composed of a long pipe and several groups of short pipes uniformly distributed on one side of the long pipe; The inside of one end of the oil-gas double-pass cavity 17 near the ejector pin head 9 is connected to the inside of one end of the long pipe through a pipeline; One end of the short pipe extends to the outer wall of the movable ejector pin 7 through the guide outer cylinder 5, and the short pipe is in close proximity to but not in contact with the outer wall of the movable ejector pin 7.

[0058] In specific implementation, when the movable ejector pin 7 moves, the oil distribution pipe 13 will not be in friction with the movable ejector pin 7, and the lubricating oil in the oil distribution pipe 13 can be more smoothly sprayed onto the surface of the movable ejector pin 7 and carried into the contact surface between the movable ejector pin 7 and the guide outer cylinder 5 as the movable ejector pin 7 moves.

[0059] The oil pressure compensation cavity 15 is provided with several groups of oil distribution pipes 13 in the same number as the oil distribution pipes 13; One end of the oil-gas double-pass cavity 17 is communicated with the interior of the oil pressure compensation cavity 15 through a pipeline near the needle head 9; In the specific implementation, if the oil in the oil-gas double-pass cavity 17 is depleted, a small amount of air will be sucked when the drag-reducing component sucks the excess lubricating oil, and the lubricating oil in the oil pressure compensation cavity 15 can supplement the oil in time to ensure that the lubricating oil in the oil-gas double-pass cavity 17 is in a full state. In this way, the air in the cavity for storing the lubricating oil in the oil-gas double-pass cavity 17 is extremely small, and the air amount can be ignored or even there is no air. When the movable needle 7 is just pushed forward, the lubricating oil can be sprayed to the surface of the movable needle 7 along the oil distribution pipeline 13.

[0060] The oil supplement pipeline 11 is fixedly inserted into one end of the guide outer cylinder 5 near the needle head 9; One end of the oil supplement pipeline 11 extends to the outside of the guide outer cylinder 5; The interior of the oil supplement pipeline 11 is communicated with the interior of the oil pressure compensation cavity 15.

[0061] In the specific implementation, during the regular maintenance, the lubricating oil can be supplemented into the oil pressure compensation cavity 15 through the oil supplement pipeline 11. It needs to be noted that the lubricating oil supplementing mode needs to adopt the pressurized oil injection mode. The sealing mode of the end of the oil supplement pipeline 11 is similar to the sealing mode of the air valve of the automobile tire, that is, the oil supplement pipeline 11 can be opened only when the oil injection gun is pressed down, and the oil supplement pipeline 11 is closed when the oil injection gun is removed. This mode is the prior art, and will not be described in detail here. The purpose is to use the oil pressure to compress the first spring 20 to provide sufficient storage space for the lubricating oil. When the first spring 20 rebounds in the later period, the stored lubricating oil can be pushed into the oil-gas double-pass cavity 17 by the sealing plate 21.

[0062] The sealing assembly further comprises a blocking ring 26 fixed in the air cavity 19; In the specific implementation, the blocking ring 26 can prevent the squeeze-in piston plate 27 from being excessively withdrawn. In this way, when the air in the air cavity 19 is sucked away, the squeeze-in piston plate 27 will not move reversely to cause the sealing rubber ring 28 to be damaged by being hard pulled. In the present application, the sealing rubber ring 28 only needs to be sufficiently squeezed and tightly attached to the surface of the needle head 9, and does not need to be excessively pulled reversely to cause unnecessary deformation and friction damage, thereby prolonging the service life of the sealing rubber ring 28.

[0063] The squeeze-in piston plate 27 is movably arranged between the blocking ring 26 and the sealing rubber ring 28; The inner and outer diameters of the squeeze-in piston plate 27 are consistent with the inner and outer diameters of the air cavity 19; In the specific implementation, the extrusion piston plate 27 separates the air cavity 19 into two chambers, and the chamber in which the sealing rubber ring 28 is located is in a closed state under the blocking of the sealing rubber ring 28 and the extrusion piston plate 27. There is no air residue in the chamber, the sealing rubber ring 28 fills the entire chamber, and when the extrusion piston plate 27 is forced to extrude the sealing rubber ring 28 under the influence of the air pressure of the other chamber, the molecular structure of the sealing rubber ring 28 changes, deforms, and protrudes outward from the air cavity 19, that is, the surface of the needle head 9.

[0064] The side of the sealing rubber ring 28 extends to the outside of the air cavity 19 and is in close contact with the surface of the needle head 9; In the specific implementation, the greater the deformation of the sealing rubber ring 28, the tighter it is attached to the surface of the needle head 9. The sealing rubber ring 28 is subjected to the forward thrust brought by the extrusion piston plate 27, which is just offset by the retreat force of the needle head 9, and the two complement each other, so that the sealing effect is good, and the fluid is not easy to overflow from the gap between the needle head 9 and the punch 2 in the injection molding process.

[0065] The inside of the air cavity 19 is communicated with the inside of the other end of the oil-gas double-pass chamber 17 through the gas conveying pipe 10; The gas conveying pipe 10 is provided with a plurality of groups in proportion.

[0066] In the specific implementation, when the piston ring 14 retreats, the air in the other chamber of the oil-gas double-pass chamber 17 is pushed along the gas conveying pipe 10 into the air cavity 19, providing a power source for the extrusion piston plate 27 to extrude the sealing rubber ring 28.

[0067] A plurality of groups of air pressure compensation chambers 16 are arranged in proportion at the other end of the guide outer cylinder 5 away from the needle head 9; The inside of the air pressure compensation chamber 16 is communicated with the inside of one end of the oil-gas double-pass chamber 17 away from the needle head 9 through a pipeline; The inside of the oil pressure compensation chamber 15 and the air pressure compensation chamber 16 is movably provided with a sealing plate 21; The sealing plate 21 is fixed with a first spring 20 between the sealing plate 21 and the inner wall of the guide outer cylinder 5.

[0068] In the specific implementation, if the air in the device is lost, when the piston ring 14 is pushed forward, there is not enough air in the air cavity 19 and the gas conveying pipe 10 to enter the oil-gas double-pass chamber 17, which will cause the piston ring 14 to be blocked, and the remaining air in the air pressure compensation chamber 16 can make up for the loss of air. When the sealing rubber ring 28 is difficult to continue to deform under the obstruction of the extrusion piston plate 27 and the needle head 9, the space for storing air in the air pressure compensation chamber 16 increases under the action of the movement of the sealing plate 21 and the compression of the first spring 20, and the remaining air enters the air pressure compensation chamber 16.

[0069] One end of the guide outer cylinder 5 is fixedly inserted with a gas supplement pipe 12 away from the position of the ejector pin head 9; One end of the gas supplement pipe 12 extends to the outside of the guide outer cylinder 5. The inside of the gas supplement pipe 12 communicates with the inside of the gas pressure compensation chamber 16.

[0070] In the specific implementation, during the regular maintenance, air can be supplemented into the gas pressure compensation chamber 16 through the gas supplement pipe 12, and it needs to be noted that the air supplement needs to be in the pressurized mode, which is similar to the above-mentioned oil supplement, and the same reason is that this mode is the prior art, and will not be described in detail here, and the purpose is to use the gas pressure to compress the first spring 20 to provide a storage space for the sufficient air to prevent the vacuum negative pressure condition in the oil-gas double-pass chamber 17, and it needs to be noted that the elastic force of the plurality of groups of first springs 20 should be adapted to the pressure of the gas pressure or oil pressure in the oil-gas double-pass chamber 17.

[0071] Working principle: when the automatic ejection guide mechanism of the plastic part is used, first, the mains electricity is connected to supply power to the whole device, and the injection molding process is consistent with the prior art after the injection molding work is completed, and the present application will not be described in detail here, when the plastic part needs to be ejected, the mold is normally opened, and then the oil cylinder 3 is started to make the piston end of the oil cylinder 3 push the disc 4 forward, the fixed part 6 drives the pioneer rod 22 to push forward, when the pioneer rod 22 moves forward, the slope between the other end of the pioneer rod 22 and the inner wall of the movable ejector pin 7 interacts to make the movable ejector pin 7 be squeezed and expanded stably under the limitation of the cross slide rail, until the outer wall of the movable ejector pin 7 is tightly attached to the inner wall of the guide outer cylinder 5, the movable ejector pin 7 cannot continue to expand, the friction between the pioneer rod 22 and the movable ejector pin 7 is large, so that the pioneer rod 22 can drive the movable ejector pin 7 to move forward, even if the friction between the pioneer rod 22 and the movable ejector pin 7 is not enough to make the movable ejector pin 7 move forward, the fixed part 6 will also drive the second spring 24, the telescopic cylinder 23 and the movable ejector pin 7 to move forward synchronously after the second spring 24 is fully squeezed, and the annular return spring 25 is stretched at the same time when the movable ejector pin 7 is expanded.

[0072] When the fixed part 6 is pushed forward, the push rod 8 pushes the piston ring 14 to move forward, the piston ring 14 pushes the lubricating oil in the chamber near the one end of the oil-gas double-pass chamber 17 close to the ejector pin head 9 along the oil distribution pipe 13 to the surface of the movable ejector pin 7, so that the friction loss between the movable ejector pin 7 and the guide outer cylinder 5 is reduced, and the gas pressure in the other end of the chamber in the oil-gas double-pass chamber 17 is reduced, the air in the air cavity 19 and the gas conveying pipe 10 will be sucked into the oil-gas double-pass chamber 17, if the amount of air in the air cavity 19 and the gas conveying pipe 10 is insufficient, the sealing plate 21 will supplement the air in the gas pressure compensation chamber 16 into the oil-gas double-pass chamber 17 under the rebound of the first spring 20, in this way, until the movable ejector pin 7 drives the ejector pin head 9 to move forward and push the plastic part adsorbed on the surface of the convex mold 2 out.

[0073] When the fixed part 6 is retracted, the pioneer rod 22 is retracted synchronously, and one end of the second spring 24 is pulled by the fixed part 6. Under the resistance of the rebounding force of the second spring 24, the other end of the second spring 24 pulls the telescopic cylinder 23 to retract synchronously with the fixed part 6. Under the action of the cross slide rail, the telescopic cylinder 23 pulls the movable ejector pin 7 and the ejector pin head 9 to retract synchronously. When the pioneer rod 22 retracts one step ahead of the movable ejector pin 7, the inclined surface between the pioneer rod 22 and the movable ejector pin 7 is separated first, and the movable ejector pin 7 is no longer affected by the expansion of the pioneer rod 22. Under the rebounding of the annular return spring 25, the movable ejector pin 7 is retracted to become an initial hollow cylindrical structure. At this time, the movable ejector pin 7 is no longer in close contact with the guide outer cylinder 5, and the friction between them is very small, or even there is no contact, that is, there is no friction. The wear of the movable ejector pin 7 and the guide outer cylinder 5 is greatly reduced, and the ejector pin head 9 can be retracted to the side of the punch 2 until it is flush.

[0074] When the fixed part 6 is retracted, the push rod 8 drives the piston ring 14 to retract, the internal pressure of the oil-gas double-pass cavity 17 near the one end of the ejector pin head 9 becomes smaller, the excess lubricating oil on the surface of the movable ejector pin 7 is sucked back into the oil-gas double-pass cavity 17 through the oil separation pipe 13, and the lubricating oil in the oil pressure compensation cavity 15 also enters the oil-gas double-pass cavity 17. The one end of the oil-gas double-pass cavity 17 near the ejector pin head 9 is kept in a state of being filled with lubricating oil, preventing too much air from being sucked into the oil-gas double-pass cavity 17. The air in the other end cavity of the oil-gas double-pass cavity 17 is pushed into the air cavity 19 along the piston ring 14. As the air in the air cavity 19 becomes more and more, the air pressure will push the piston plate 27 to be pushed, so that the sealing rubber ring 28 is compressed and deformed. Until the ejector pin head 9 is tightly attached to the sealing rubber ring 28, the air cavity 19 cannot hold more air. At this time, the excess air in the oil-gas double-pass cavity 17 enters the air pressure compensation cavity 16, and the sealing plate 21 is pressed, so that the first spring 20 is compressed. The space for storing air in the air pressure compensation cavity 16 increases, and the excess air can enter the air pressure compensation cavity 16.

[0075] Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can modify the technical solutions described in the foregoing embodiments or make equivalent replacements to some technical features within the spirit and principles of the present application. Any modification, equivalent replacement, improvement, etc. made within the scope of the present application shall be included in the protection scope of the present application.

Claims

1. An automatic ejection guide mechanism for plastic parts, comprising an injection mold (1), a punch (2) fixed inside the injection mold (1), a hydraulic cylinder (3) fixed on one side of the injection mold (1), and a disc (4) fixed at the piston end of the hydraulic cylinder (3), characterized in that, Also includes: The guide cylinder (5) is fixed on one side of the punch (2); The jacking assembly, which achieves stable movement through adaptive expansion at the axis of the guide outer cylinder (5), is active. A drag-reducing component installed inside the guide outer cylinder (5) and driven by the oil cylinder (3) to adaptively release and retract lubricating oil; A sealing assembly that adapts to changes in gas pressure and is installed inside the guide outer cylinder (5); The push assembly includes several sets of movable ejector pins (7) arranged in equal proportions at the axis of the movable through guide outer cylinder (5), ejector pin heads (9) that are movablely inserted in the punch (2), and pioneer rods (22) that are movablely inserted inside the movable ejector pins (7). The drag reduction component includes an oil-gas dual passage chamber (17) opened inside the guide outer cylinder (5), a piston ring (14) sliding inside the oil-gas dual passage chamber (17), and an oil pressure compensation chamber (15) opened inside one end of the guide outer cylinder (5). The sealing assembly includes an air cavity (19) opened inside the punch (2) and a sealing rubber ring (28) movably disposed inside one end of the air cavity (19).

2. The automatic ejection guide mechanism for a plastic part according to claim 1, characterized in that: Several sets of movable ejector pins (7) are arranged together to form a hollow cylinder; The hollow cylinder is tightly wrapped around the outside of the pioneer rod (22); Both ends of the hollow cylinder are fitted with annular return springs (25).

3. The automatic ejection guide mechanism for a plastic part according to claim 1, characterized in that: The jacking assembly also includes a fastener (6) fixed to one side of the disc (4); A telescopic cylinder (23) is movably inserted into one side of the fixing member (6); One end of the telescopic cylinder (23) extends to the outside of the fixing member (6) and is connected to one end of the movable ejector pin (7) via a cross slide rail; The other end of the movable ejector pin (7) is also connected to one end of the ejector pin head (9) via a cross slide rail; A second spring (24) is fixed between the inner wall of the fixing member (6) and the other end of the telescopic cylinder (23), and the second spring (24) is movably sleeved on the outside of the pioneer rod (22).

4. The automatic ejection guide mechanism for a plastic part according to claim 1, characterized in that: One end of the pioneer rod (22) passes through the middle of the telescopic cylinder (23) and is fixedly connected to the inner wall of the fixing member (6); The other end of the pioneer rod (22) is configured as a circumference with a sloping side; The movable ejector pin (7) has an inclined surface in the middle of its inner wall that is adapted to the other end of the pilot rod (22).

5. The automatic ejection guide mechanism for a plastic part according to claim 1, characterized in that: The surface of the punch (2) is provided with a circular groove; The ejector pin (9) is set in a frustum shape, and the maximum diameter of the ejector pin (9) is consistent with the inner diameter of the circular groove.

6. The automatic ejection guide mechanism for a plastic part according to claim 1, characterized in that: The drag reduction component also includes several sets of push rods (8) that are evenly distributed on one side of the fixing member (6); One end of several sets of push rods (8) moves through the guide outer cylinder (5) and is fixedly connected to one side of the piston ring (14); The size of the piston ring (14) is adapted to the size of the oil-gas dual-pass chamber (17). The guide outer cylinder (5) has a tube placement chamber (18) inside; The interior of the tubing chamber (18) is fixed with a number of component oil pipes (13) arranged in equal proportions. The oil distribution pipe (13) consists of a long pipe and several groups of short pipes evenly distributed on one side of the long pipe; The oil and gas dual-pass chamber (17) is connected to the inside of one end of the long tube near the needle head (9) through a pipe; One end of the short tube extends through the guide outer cylinder (5) to the outer wall of the movable ejector pin (7), and the short tube is infinitely close to the outer wall of the movable ejector pin (7) but does not contact it.

7. The automatic ejection guide mechanism for a plastic part according to claim 1, characterized in that: The oil pressure compensation chamber (15) has several sets of oil distribution pipes (13) in the same number as the oil distribution pipes (13); The oil-gas dual-pass chamber (17) is connected to the interior of the oil pressure compensation chamber (15) via a pipe near the ejector pin (9) at one end; An oil supply pipe (11) is fixedly inserted at one end of the guide outer cylinder (5) near the ejector pin (9); One end of the oil replenishment pipe (11) extends to the outside of the guide outer cylinder (5); The interior of the oil replenishment pipe (11) is connected to the interior of the oil pressure compensation chamber (15).

8. The automatic ejection guide mechanism for a plastic part according to claim 1, characterized in that: The sealing assembly also includes a barrier ring (26) fixed inside the air cavity (19). An extrusion piston plate (27) is movably disposed between the barrier ring (26) and the sealing rubber ring (28). The inner and outer diameters of the extrusion piston plate (27) are the same as the inner and outer diameters of the air chamber (19); The side of the sealing rubber ring (28) extends to the outside of the air cavity (19) and is in close contact with the surface of the ejector pin (9); The interior of the gas chamber (19) is connected to the other end of the oil-gas dual-pass chamber (17) through the gas supply pipe (10); The gas pipeline (10) is provided in several sets in equal proportion.

9. The automatic ejection guide mechanism for a plastic part according to claim 1, characterized in that: The other end of the guide outer cylinder (5) has several sets of air pressure compensation chambers (16) that are proportionally distributed at a distance from the ejector pin (9). The interior of the air pressure compensation chamber (16) is connected to the interior of the oil and gas dual passage chamber (17) at one end away from the ejector pin (9) via a pipe; Both the oil pressure compensation chamber (15) and the air pressure compensation chamber (16) are equipped with a sealing plate (21). A spring (20) is fixed between the sealing plate (21) and the inner wall of the guide cylinder (5).

10. The automatic ejection guide mechanism for a plastic part according to claim 1, characterized in that: An air supply tube (12) is fixedly inserted at one end of the guide outer cylinder (5) away from the pin head (9); One end of the air supply pipe (12) extends to the outside of the guide outer cylinder (5); The interior of the air supply pipe (12) is connected to the interior of the air pressure compensation chamber (16).

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