Injection mold and injection method based on a plastic pump head of a cooling oil pump

Abstract

The application relates to the technical field of injection molds, and discloses an injection mold based on a plastic pump head of a cooling oil pump and an injection molding method thereof, which comprises an upper mold, an upper mold core arranged on the inner wall of the upper mold, a lower mold, a lower mold core arranged on the inner wall of the lower mold, and an injection mechanism arranged on the upper mold core. The injection mold based on the plastic pump head of the cooling oil pump and the injection molding method thereof are provided with a ring-shaped cooling mechanism, a sleeve countercurrent structure formed by an equidistant spiral cooling inner pipe and an equidistant spiral cooling outer pipe, the cooling medium is pre-cooled to the waste liquid which is about to be demolded in the starting section, the heat accumulation at the cooling end is effectively eliminated in combination with a profiled spiral path of a precise surrounding cavity, the temperature difference of inlet and outlet water of the cooling path is greatly reduced, the temperature field of the pump head cavity is ensured to be highly consistent, the internal stress, warping and shrinkage holes caused by uneven cooling are inhibited from the physical level, and the size stability and mechanical strength of the pump head are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of injection mold technology, specifically to an injection mold based on a plastic pump head of a cooling oil pump and its injection method. Background Technology

[0002] The injection mold for the plastic pump head of the cooling oil pump is a special injection mold designed for mass production of plastic pump heads for cooling oil pumps. It can be adapted to the injection molding needs of high temperature resistant engineering plastics such as PP, glass fiber reinforced PA, and PPS.

[0003] Traditional injection molds for plastic pump heads used in cooling oil pumps typically employ conventional drilled cooling channels. Due to the complex structure and uneven wall thickness of the pump head components, conventional channels struggle to achieve precise conformal fitting to the mold cavity. This results in a significant temperature gradient as the cooling medium absorbs heat during its long circulation path, leading to severe heat buildup at the cavity end furthest from the inlet. This uneven cooling caused by the large temperature difference between the inlet and outlet water easily generates significant internal residual stress in the plastic pump head during molding, leading to defects such as surface shrinkage cavities, overall warping, and dimensional inaccuracies. These defects severely impact the pump head's sealing performance and mechanical strength under high-pressure conditions. Summary of the Invention

[0004] Technical problems to be solved

[0005] To address the shortcomings of existing technologies, this invention provides an injection mold based on a plastic pump head for a cooling oil pump and its injection method, which solves the problems of uneven cooling in traditional molds that easily lead to heat accumulation, high internal stress, and warping deformation in the pump head.

[0006] Technical solution

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] An injection mold based on a plastic pump head of a cooling oil pump includes: an upper mold with an upper core disposed on its inner wall; a lower mold with a lower core disposed on its inner wall; an injection mechanism disposed on the upper core for injection molding when the upper and lower molds are closed; a homogenizing mechanism disposed on the lower core for uniformly injecting molten material; and an annular cooling mechanism disposed on the lower mold for uniformly cooling the molten material after injection, the annular cooling mechanism including: a cooling drain pipe, the cooling drain pipe being fixedly connected to... Attached to the lower mold core, two cooling return outer pipes are fixedly connected to the cooling drain pipe. The ends of the two cooling return outer pipes away from the cooling drain pipe are connected to equidistant spiral cooling outer pipes. Equidistant spiral cooling inner pipes are fixedly connected to the inner walls of the equidistant spiral cooling outer pipes. The inner walls of the equidistant spiral cooling inner pipes and the equidistant spiral cooling outer pipes are connected. A coolant inlet pipe is fixedly connected to the equidistant spiral cooling inner pipe and is fixedly connected to the inner wall of the cooling return outer pipe. A triggering mechanism is set on the upper and lower mold cores and is used to trigger the annular cooling mechanism during injection molding.

[0009] Preferably, the injection molding mechanism includes an injection head, which is fixedly connected to the upper mold core. A power-collecting post is provided on the side wall of the injection head, penetrating the side wall and fixedly connected to the injection head. An electromagnet is fixedly connected to the power-collecting post, located inside the injection head. A guide post is provided through the inner wall of the electromagnet, slidably connected to the inner wall of the electromagnet. A magnetic boss is fixedly connected to the end of the guide post away from the electromagnet. A return spring is connected between the magnetic boss and the electromagnet. A sprue is provided at the end of the injection head. The inner wall of the sprue is initially blocked by the magnetic boss, with the protruding portion of the magnetic boss initially inserted into the inner wall of the sprue.

[0010] Preferably, the triggering mechanism includes a side hollow block disposed on the side of the injection head. A linkage rod is fixedly connected to the side wall of the magnetic boss. A first strong magnetic block is fixedly connected to the end of the linkage rod away from the magnetic boss. An external connecting pipe is fixedly connected to the inner wall of the lower mold. A middle connecting cylinder is fixedly connected to the external connecting pipe. An input pipe is fixedly connected to the side wall of the middle connecting cylinder. A telescopic rod is fixedly connected to the inner wall of the middle connecting cylinder. A second strong magnetic block is fixedly connected to the side of the telescopic rod away from the inner wall of the middle connecting cylinder. A guide spring is connected between the second strong magnetic block and the inner wall of the middle connecting cylinder. In the initial state, the second strong magnetic block is tightly attached to the external connecting pipe under the action of the guide spring. The input pipe penetrates the inner wall of the cooling drain pipe and is fixedly connected to the inner wall of the cooling drain pipe. The coolant inlet pipe is connected to the end of the input pipe away from the middle connecting cylinder.

[0011] Preferably, the homogenizing mechanism includes a double-opening material distribution pipe, which is fixedly connected to the lower mold core. A material inlet is provided in the middle of the double-opening material distribution pipe, and two equidistant irregular rings are symmetrically arranged on both sides of the double-opening material distribution pipe. The equidistant irregular rings precisely surround the plastic pump head forming cavity, and several material outlets are provided on the inner wall of the equidistant irregular rings.

[0012] Preferably, the double-opening feed pipe is fixedly connected to the outer wall of the equidistant irregular-shaped ring with equidistant irregular-shaped heating elements, and the equidistant irregular-shaped heating elements are provided with power supply ports.

[0013] Preferably, the outer wall of the guide column is provided with at least two sets of anti-friction oil grooves, and the inner wall of the electromagnet is provided with a self-lubricating bushing corresponding to the position of the anti-friction oil groove.

[0014] Preferably, the front end face of the protruding part of the magnetic boss is processed into a micro-arc spherical structure, and the inner edge of the injection port is provided with a chamfered cone surface that matches the micro-arc spherical structure.

[0015] Preferably, a high-temperature resistant rubber sealing gasket is attached and fixed to one end face of the second strong magnetic block near the external connecting pipe, and the sealing gasket forms a flexible fit with the water inlet of the external connecting pipe under the pressure of the guide spring.

[0016] Preferably, the internal flow channel of the double-opening feed pipe is provided with a streamlined flow divider cone at the part where it turns from the feed inlet to the two sides of the equidistant irregular rings. The flow divider cone smoothly guides the vertically entering melt to the horizontal sides.

[0017] An injection molding method based on an injection mold for a cooling oil pump plastic pump head, further comprising the following injection molding methods:

[0018] Step 1: The mold closing action begins. The upper mold moves the upper mold core closer to the lower mold and lower mold core. During this mold closing stroke, the side hollow block fixed to the side of the injection head descends until the side hollow block and the connecting cylinder fixed to the inner wall of the lower mold achieve precise spatial fit. At this time, the magnetic field generated by the first strong magnetic block inside the side hollow block penetrates the wall thickness on both sides and attracts the second strong magnetic block inside the connecting cylinder across the space. The strong magnetic attraction forces the second strong magnetic block to slide on the inner wall of the connecting cylinder and overcome the preload of the guide spring to compress and store energy. The sliding of the second strong magnetic block synchronously drives the telescopic rod fixed to it to retract, thereby completely detaching the front end of the second strong magnetic block from the outer mold. The water inlet of the connecting pipe; this mechanical linkage opens the originally blocked fluid path, allowing the cooling medium to enter the inner cavity of the middle connecting cylinder from the outer connecting pipe, and then flow into the input pipe without obstruction. Next, it is pressed into the starting section of the equidistant spiral cooling inner tube through the coolant inlet pipe. The fluid flows along the equidistant spiral cooling inner tube until it overflows at the end, and then flows back along the cavity between the equidistant spiral cooling outer tube and the inner tube for heat exchange. The waste liquid after heat exchange is collected in the cooling return outer tube and finally discharged outside the mold through the cooling drain pipe. This complete flow process realizes the pre-adjustment of the mold forming cavity for circulating cooling before formal injection molding, ensuring that the mold is in the optimal initial forming temperature field.

[0019] Step Two: Once the mold pre-adjustment is complete and the injection molding process begins, external current is introduced through the power-taking post set on the side wall of the injection head and supplied to the electromagnet. The electromagnet generates a strong magnetic field, and the magnetic force causes the magnetic boss located in its inner hole to overcome the resistance of the return spring and slide in the direction. The magnetic boss drives the guide post to move synchronously, causing the raised part of the magnetic boss to disengage and open the injection port. At the same time, the axial displacement of the magnetic boss is rigidly transmitted through the linkage rod on the side wall, causing the first strong magnetic block at the end of the linkage rod to slide synchronously away from the lower mold and the second strong magnetic block in the side hollow block. As the distance between the two increases, the magnetic attraction between the first strong magnetic block and the second strong magnetic block quickly weakens to disappear. The second strong magnetic block, which loses its magnetic pull, is driven by the elastic restoring force released by the guide spring and quickly resets forward along the guide trajectory of the telescopic rod. This causes the front end face of the second strong magnetic block and its high-temperature resistant rubber sealing gasket layer to re-tightly contact and physically press against the inlet of the external connecting pipe, blocking the opening of the middle connecting cylinder to the external connecting pipe.

[0020] Step 3: At the same time as the injection port is opened, the external power supply powers the equidistant irregular-shaped heating element through the power input port, generating heat that is conducted to the pipe walls of the double-opening distribution pipe and the equidistant irregular-shaped ring; the high-pressure plastic melt is injected from the injection port, first directly into the inlet in the middle of the docking double-opening distribution pipe, and then smoothly divided to the left and right sides under the guidance of the internal streamlined flow divider cone, and then enters the equidistant irregular-shaped rings that precisely surround the cavity on both sides for envelope flow, and finally is injected into the molding cavity simultaneously through multiple outlets;

[0021] Step 4: After the cavity filling is completed, the power supply to the power take-off column is cut off, causing the magnetic field of the electromagnet to disappear instantly. Under the strong axial thrust released by the return spring, the magnetic boss quickly returns to its original position along the guide column. The micro-arc spherical structure at its front end is tightly pressed into the chamfered conical surface of the inner edge of the injection port. At the same time, the forward return action of the magnetic boss drives the first strong magnetic block to move back to the trigger position close to the second strong magnetic block through the linkage rod. The magnetic attraction is re-established and overcomes the guide spring to pull the second strong magnetic block open. The external connecting pipe is reopened, and the cooling medium enters the inner cavity of the middle connecting cylinder through the external connecting pipe again. Then it flows into the input pipe without obstruction, and then is pressed into the starting section of the equidistant spiral cooling inner tube through the coolant inlet pipe. At this time, the low temperature cooling of the equidistant spiral cooling inner tube has just entered. The liquid will pass through its pipe wall to pre-cool the high-temperature reflux coolant inside the equidistant spiral cooling outer pipe near the cooling return outer pipe, which is about to be discharged from the mold, and then the cooling medium continues to flow along the spiral trajectory of the equidistant spiral cooling inner pipe to its far end and overflows from the end opening into the cavity between the equidistant spiral cooling inner pipe and the equidistant spiral cooling outer pipe. Then, under the constraint of the pipe wall of the equidistant spiral cooling outer pipe, the cooling medium flows back from far to near along the equidistant spiral path that precisely surrounds the pump head cavity. During the reverse flow process, it fully absorbs the heat conducted by the plastic melt in the molding cavity. The heat-exchange waste liquid finally collects into two symmetrically arranged cooling return outer pipes and is introduced into the cooling drain pipe fixedly connected to the lower mold core and discharged outside the mold.

[0022] Step 5: After cooling and solidification for a set time, the injection molding machine pulls the upper mold and drives the upper mold core and injection head to open the mold as a whole. During the physical stroke of mold opening, the side hollow block fixed on the side of the injection head moves away from the central connecting cylinder and gradually moves away from the central connecting cylinder fixed on the lower mold. As the distance increases, the magnetic constraint force of the first strong magnetic block on the second strong magnetic block is released. At this time, the second strong magnetic block located inside the central connecting cylinder is once again completely controlled by the push of the guide spring and automatically rebounds along the telescopic rod, so that its end face tightly presses against the water inlet of the external connecting pipe, cutting off the fluid source from the external connecting pipe.

[0023] Beneficial effects

[0024] Compared with the prior art, the present invention provides an injection mold based on a plastic pump head of a cooling oil pump and the same injection method, which has the following beneficial effects:

[0025] 1. This injection mold and injection method based on a plastic pump head for a cooling oil pump utilizes a ring-shaped cooling mechanism. Through a counter-flow structure formed by an equidistant spiral cooling inner tube and an equidistant spiral cooling outer tube, the cooling medium pre-cools the waste liquid about to exit the mold in the initial stage. Combined with a precisely contoured spiral path around the cavity, it effectively eliminates heat accumulation at the cooling end, significantly reduces the temperature difference between the inlet and outlet water in the cooling path, ensures a highly consistent temperature field in the pump head cavity, and physically suppresses internal stress, warping, and shrinkage cavities caused by uneven cooling, significantly improving the dimensional stability and mechanical strength of the pump head.

[0026] 2. This injection mold and injection method based on the plastic pump head of a cooling oil pump utilizes an injection mechanism to achieve needle valve-type injection by driving a magnetic boss with an electromagnet. After injection, a return spring drives the micro-arc spherical structure of the magnetic boss to press into the chamfered conical surface, forming a high-pressure line contact seal. This not only completely cuts off the feed drool but also achieves secondary mechanical extrusion and pressure replenishment of the gate residue, improving the molecular arrangement density at the gate position. This solves the structural weakness and leakage problems caused by the loose gate. Furthermore, the use of anti-friction oil grooves and self-lubricating bushings ensures the high-frequency reciprocating reliability of the mechanism.

[0027] 3. The injection mold and injection method based on the plastic pump head of the cooling oil pump utilize a trigger mechanism. Through non-contact magnetic coupling between the first and second strong magnetic blocks, the opening and closing actions of the injection needle valve and the opening and closing actions of the mold are directly converted into on / off signals of the cooling circuit. This ensures that the cooling supply is automatically cut off during the high-pressure spraying stage of injection molding to prevent the melt temperature from dropping too quickly, while the cooling is precisely activated during the pressure holding and mold closing gaps. This linkage design can achieve dynamic and precise control of the cooling timing without the need for an additional electrical control system, while avoiding mechanical wear and coolant splashing under high-frequency opening and closing.

[0028] 4. This injection mold and injection method based on a plastic pump head of a cooling oil pump utilizes a homogenization mechanism. Through a double-opening distribution pipe and a streamlined flow divider cone, the melt is smoothly distributed into symmetrical, equidistant irregularly shaped rings, and simultaneously injected into the cavity from multiple outlets at multiple points. This completely changes the drawbacks of long flow paths, large pressure drops, and uneven distribution caused by traditional single gates. Combined with real-time temperature control compensation of equidistant irregularly shaped heating plates, it ensures that the melt maintains excellent flow activity throughout the entire path, greatly improving the homogeneity and molding quality of filling complex pump head cavities. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0030] Figure 2 This is a schematic diagram of the structure of the upper mold core and the lower mold core of the present invention;

[0031] Figure 3This is a schematic diagram of the injection head structure of the present invention;

[0032] Figure 4 This is a schematic diagram of the structure of the power-collecting column of the present invention;

[0033] Figure 5 This is a schematic diagram of the cross-sectional structure of the injection head of the present invention;

[0034] Figure 6 This is a schematic diagram of the homogenizing mechanism of the present invention;

[0035] Figure 7 This is a schematic diagram of the structure of the equidistant irregular-shaped heating element of the present invention;

[0036] Figure 8 This is a schematic diagram of the cross-section of the lower mold core of the present invention;

[0037] Figure 9 This is a schematic diagram of the annular cooling mechanism of the present invention;

[0038] Figure 10 This is a schematic diagram of the cross-section of the connecting cylinder in this invention;

[0039] Figure 11 This is a schematic diagram of the cross-sectional view of the cooling drain pipe and the cooling return outer pipe of the present invention;

[0040] Figure 12 This is a schematic diagram of the cross-section of the equidistant spiral cooling outer tube of the present invention.

[0041] In the diagram: 1. Upper mold; 2. Lower mold; 3. Upper mold core; 4. Lower mold core; 5. Injection mechanism; 51. Injection head; 52. Power supply post; 53. Electromagnet; 54. Guide post; 55. Magnetic boss; 56. Return spring; 57. Injection port; 6. Triggering mechanism; 61. Side hollow block; 62. Linkage rod; 63. First strong magnet; 64. External connecting pipe; 65. Middle connecting cylinder; 66. Input pipe; 67. 68. Telescopic rod; 69. Second strong magnet; 70. Guide spring; 81. Homogenization mechanism; 72. Double-opening feed pipe; 73. Feed inlet; 74. Equidistant irregular-shaped ring; 75. Feed outlet; 76. Equidistant irregular-shaped heating element; 87. Power supply port; 88. Ring-shaped cooling mechanism; 81. Cooling drain pipe; 82. Cooling return outer pipe; 83. Equidistant spiral cooling outer pipe; 84. Equidistant spiral cooling inner pipe; 85. Coolant inlet pipe. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] Please see Figures 1-12An injection mold based on a plastic pump head for a cooling oil pump includes: an upper mold 1 with an upper mold core 3 disposed on its inner wall; a lower mold 2 with a lower mold core 4 disposed on its inner wall; an injection mechanism 5 disposed on the upper mold core 3 for injection molding when the upper mold 1 and the lower mold 2 are closed; a homogenizing mechanism 7 disposed on the lower mold core 4 for uniformly injecting molten material; and an annular cooling mechanism 8 disposed on the lower mold 2 for uniformly cooling the molten material after injection molding. Component 8 includes: a cooling drain pipe 81, which is fixedly connected to the lower mold core 4. Two cooling return outer pipes 82 are fixedly connected to the cooling drain pipe 81. One end of each cooling return outer pipe 82 away from the cooling drain pipe 81 is connected to an equidistant spiral cooling outer pipe 83. An equidistant spiral cooling inner pipe 84 is fixedly connected to the inner wall of the equidistant spiral cooling outer pipe 83. The equidistant spiral cooling inner pipe 84 communicates with the inner wall of the equidistant spiral cooling outer pipe 83. A coolant inlet pipe 85 is fixedly connected to the equidistant spiral cooling inner pipe 84. On the inner wall of the cooling return outer pipe 82, when the cooling process starts, the initial cooling medium at a lower temperature is first forced in through the coolant inlet pipe 85, which is fixedly connected to the inner wall of the cooling return outer pipe 82, and immediately enters the initial section of the nested equidistant spiral cooling inner pipe 84. At this time, the low-temperature coolant that has just entered the equidistant spiral cooling inner pipe 84 will pass through its pipe wall to pre-cool and heat exchange the high-temperature return coolant inside the equidistant spiral cooling outer pipe 83 near the cooling return outer pipe 82, which is about to be discharged from the mold. Subsequently, the cooling medium continues to cool along the equidistant spiral cooling inner pipe. The spiral trajectory of tube 84 flows to its far end and overflows from the end opening into the cavity between the equidistant spiral cooling inner tube 84 and the equidistant spiral cooling outer tube 83. Then, under the constraint of the tube wall of the equidistant spiral cooling outer tube 83, the cooling medium flows back from far to near along the equidistant spiral path that precisely surrounds the pump head cavity. During the reverse flow process, it fully absorbs the heat conducted by the plastic melt in the molding cavity. The heat-exchange waste liquid finally collects into the two symmetrically arranged cooling return outer tubes 82 and is introduced into the cooling drain pipe 81 fixedly connected to the lower mold core 4 to be discharged outside the mold. Its main function is to pre-cool the medium that is about to exit the mold by using the low temperature medium that just entered the mold to pre-cool the medium that is about to exit the mold through this sleeve counterflow combined with end overflow structure design. This not only effectively eliminates the heat accumulation phenomenon at the end of the cooling circuit and reduces the temperature difference between the inlet and outlet water in the entire cooling path, but also ensures that all parts of the pump head cavity are in a highly uniform temperature field. From a physical perspective, this eliminates the molding internal stress and warping deformation caused by uneven cooling to the greatest extent, and significantly improves the precision dimensional stability and mechanical strength of the plastic pump head; the triggering mechanism 6 is set on the upper mold core 3 and the lower mold core 4 and is used to trigger the annular cooling mechanism 8 during injection molding.

[0044] The injection molding mechanism 5 includes an injection head 51, which is fixedly connected to the upper mold core 3. A power-taking post 52 is provided on the side wall of the injection head 51, penetrating the side wall and fixedly connected to the injection head 51. An electromagnet 53 is fixedly connected to the power-taking post 52, located inside the injection head 51. A guide post 54 is provided through the inner wall of the electromagnet 53, slidably connected to the inner wall of the electromagnet 53. A magnetic boss 55 is fixedly connected to the end of the guide post 54 away from the electromagnet 53. The magnetic boss 55 is connected to the electromagnet 53. A return spring 56 connects the magnets 53. An injection port 57 is located at the end of the injection head 51. Initially, the inner wall of the injection port 57 is blocked by a magnetic boss 55. The protruding part of the magnetic boss 55 is initially inserted into the inner wall of the injection port 57. External current is introduced through the power-taking post 52 located on the side wall of the injection head 51 and supplied to the electromagnet 53. When the electromagnet 53 is energized and generates a magnetic field, the magnetic boss 55, under pressure, overcomes the preload of the return spring 56, causing the guide post 54, which is fixedly connected to it, to slide axially within the inner wall of the electromagnet 53. The raised portion of the magnetic boss 55, which was initially inserted into and tightly blocked the inner wall of the injection port 57, retracts and disengages from the injection port 57, causing the injection port 57 to change from a closed state to an open state, so that the molten plastic can be injected into the mold cavity through the injection port 57. After injection molding is completed, the power supply to the power post 52 is de-energized, causing the electromagnet 53 to lose its magnetic force. Under the elastic restoring force of the return spring 56, the magnetic boss 55 moves forward along the guide path of the guide post 54, causing its raised portion to re-insert into the inner wall of the injection port 57 for physical sealing. During the resetting and sealing action... At the same time, the magnetic boss 55 will squeeze the molten material on the inner wall of the injection port 57 to complete the pressure and trimming of the residual material at the end of the gate. The mechanical force of the magnetic boss 55 will be used to perform secondary extrusion on the molten material that has not yet solidified. This not only eliminates shrinkage cavities and porosity defects at the injection port 57 and prevents the molten material from producing drooling or cold material threads, but also increases the molecular arrangement density at the gate position through physical extrusion. This ensures that the pump head installation position has stronger dimensional stability and sealing and leakage prevention performance under subsequent high and low temperature cycle conditions, thereby solving the problem of structural weakness caused by the loose material at the gate.

[0045] The triggering mechanism 6 includes a side hollow block 61, which is disposed on the side of the injection head 51. A linkage rod 62 is fixedly connected to the side wall of the magnetic boss 55. A first strong magnet 63 is fixedly connected to the end of the linkage rod 62 away from the magnetic boss 55. An external connecting pipe 64 is fixedly connected to the inner wall of the lower mold 2. A middle connecting cylinder 65 is fixedly connected to the external connecting pipe 64. An input pipe 66 is fixedly connected to the side wall of the middle connecting cylinder 65. A telescopic rod 67 is fixedly connected to the inner wall of the middle connecting cylinder 65. A second strong magnet 68 is fixedly connected to the side of rod 67 away from the inner wall of the connecting cylinder 65. A guide spring 69 connects the second strong magnet 68 to the inner wall of the connecting cylinder 65. In its initial state, the second strong magnet 68 is tightly attached to the external connecting pipe 64 under the action of the guide spring 69. The input pipe 66 penetrates the inner wall of the cooling drain pipe 81 and is fixedly connected to the inner wall of the cooling drain pipe 81. The coolant inlet pipe 85 is connected to the end of the input pipe 66 away from the connecting cylinder 65 for input. Coolant enters the coolant inlet pipe 85. In the initial state of injection molding, the second strong magnetic block 68, driven by the elastic restoring force released by the guide spring 69, tightly adheres to the inlet end face of the external connecting pipe 64 to achieve physical blockage and cut off the fluid path. When the injection molding program starts, the upper mold 1 moves downward, driving the upper mold core 3 fixed on it to move towards the lower mold 2 and lower mold core 4 at the bottom to close the mold. This allows the side hollow block 61 installed on the side of the injection head 51 to precisely fit in space against the connecting cylinder 65 located on the inner wall of the lower mold 2. At this time, the magnetic field generated by the first strong magnetic block 63 inside the side hollow block 61 penetrates the wall thickness and generates magnetic attraction, adsorbing across the space and driving the opposing second strong magnetic block 68 to move in the connecting cylinder 65. This forces the guide spring 69 to store energy, and simultaneously drives the telescopic rod 67 connected to it to move, causing the second strong magnetic block 68 to leave the blocking position. At this time, the second strong magnetic block 68 no longer blocks the external connecting pipe 64, thus connecting the input pipe 66 and the external connecting pipe 64.Then, the injection molding and spraying stage begins. The magnetic boss 55 retracts to open the injection port 57. The linkage rod 62, which is fixedly connected to its side wall, drives the first strong magnetic block 63 at its end to slide synchronously away from the lower mold 2 within the side hollow block 61. Since the first strong magnetic block 63 moves away from the magnetic induction area of ​​the second strong magnetic block 68 after sliding, it can no longer sense and magnetically attract the second strong magnetic block 68, causing the magnetic coupling force to disappear. At this time, driven by the elastic potential energy released by the guide spring 69, the second strong magnetic block 68 quickly resets along the guide trajectory of the telescopic rod 67 and re-contacts and blocks the external connecting pipe 64. Therefore, the external connecting pipe 64 remains closed throughout the injection molding and spraying process until the injection is completed. At this time, the magnetic boss 55 retracts towards the injection port 57. The displacement in the 7-direction reset ultimately physically blocks the injection port 57. During the reset process, the magnetic boss 55 synchronously drives the first strong magnetic block 63 to move closer to the second strong magnetic block 68 via the linkage rod 62, re-establishing the magnetic attraction. At this time, the second strong magnetic block 68 does not block the external connecting pipe 64. This design utilizes the effective distance characteristics of magnetic coupling to ensure that the auxiliary cooling pipe is in a closed state during the highest injection pressure spraying stage, thereby preventing the auxiliary cooling pipe from negatively interfering with melt filling. Cooling intervention is performed in the gap between the initial mold closing and the end of injection molding, which greatly improves the accuracy of internal stress control and gate solidification during the pump head molding process. At the same time, the non-contact transmission solves the mechanical wear problem under high-frequency opening and closing of the mold.

[0046] The homogenizing mechanism 7 includes a double-opening distribution pipe 71, which is fixedly connected to the lower mold core 4. An inlet 72 is located in the middle of the double-opening distribution pipe 71 for connecting to the injection port 57. Two equidistant irregularly shaped rings 73 are symmetrically arranged on both sides of the double-opening distribution pipe 71, precisely surrounding the plastic pump head molding cavity. Several outlets 74 are located on the inner wall of the equidistant irregularly shaped rings 73. When the injection molding mechanism 5 is activated, the molten plastic is ejected from the injection port 57 and directly enters the cavity connected to the injection port 57. The molten material enters through the inlet 72 in the middle of the double-opening distribution pipe 71. Inside the pipe, pressure drives the flow to both sides, then it enters two symmetrically positioned, equidistant shaped rings 73 on either side of the pipe. These rings, with their precisely contoured structure surrounding the molding cavity of the plastic pump head, allow the molten material to flow equidistantly around the outer periphery of the cavity. Finally, it is injected into the molding cavity simultaneously through several outlets 74 distributed on the inner wall of the equidistant shaped rings 73. This design overcomes the problems of long flow paths and large pressure drops at the end caused by traditional injection molding with a single gate, ensuring that the molten plastic fills the complex cavity of the pump head simultaneously from multiple dimensions, greatly improving the homogeneity of the melt distribution.

[0047] The double-opening feed pipe 71 and the outer wall of the equidistant irregular-shaped ring 73 are fixedly connected to equidistant irregular-shaped heating elements 75. The equidistant irregular-shaped heating elements 75 are provided with power input ports 76. When an external power source introduces electrical energy through the power input ports 76, the equidistant irregular-shaped heating elements 75 fixedly connected to the outer wall of the double-opening feed pipe 71 and the equidistant irregular-shaped ring 73 start to heat up synchronously. The heat generated penetrates the pipe wall and acts directly on the plastic melt flowing through the double-opening feed pipe 71 and enveloping the plastic melt flowing in the equidistant irregular-shaped ring 73. This ensures that the melt maintains a constant process temperature throughout its entire path from the feed inlet 72 to each discharge port 74, thereby ensuring that the melt is evenly injected into the molding cavity through the discharge port 74 with excellent flow activity.

[0048] At least two sets of anti-friction oil grooves are circumferentially formed on the outer wall of the guide post 54, and a self-lubricating bushing corresponding to the position of the anti-friction oil groove is embedded in the inner wall of the electromagnet 53. The anti-friction oil groove is used to store lubricating medium, which, together with the self-lubricating bushing, reduces mechanical wear during the frequent sliding process of the guide post 54 and improves the action response accuracy of the needle valve opening and closing.

[0049] The front end face of the raised portion of the magnetic boss 55 is machined into a micro-arc spherical structure, and the inner edge of the injection port 57 is provided with a chamfered conical surface that matches the micro-arc spherical structure. The line contact sealing structure between the spherical surface and the conical surface increases the pressure during sealing, thereby ensuring that the melt can be cut off and the residual material squeezed out more thoroughly when the magnetic boss 55 is reset and pressurized.

[0050] The second strong magnetic block 68 has a high-temperature resistant rubber sealing gasket attached to one end face near the external connecting pipe 64. Under the pressure of the guide spring 69, the sealing gasket forms a flexible fit with the water inlet of the external connecting pipe 64, which improves the sealing tightness of the auxiliary cooling pipe in the closed state.

[0051] The internal flow channel of the double-opening feed pipe 71 is provided with a streamlined flow divider cone at the part where it turns from the feed inlet 72 to the two equidistant irregular rings 73. The flow divider cone smoothly guides the vertically entering melt to the horizontal sides, reducing the shear heat accumulation and pressure loss of the melt at the turning point.

[0052] An injection molding method based on an injection mold for a cooling oil pump plastic pump head, further comprising the following injection molding methods:

[0053] Step 1: The mold closing action begins. The upper mold 1 moves the upper mold core 3 to move closer to the lower mold 2 and lower mold core 4. During this mold closing stroke, the side hollow block 61 fixed to the side of the injection head 51 descends until the side hollow block 61 and the connecting cylinder 65 fixed to the inner wall of the lower mold 2 achieve precise spatial fit. At this time, the magnetic field generated by the first strong magnetic block 63 inside the side hollow block 61 penetrates the thickness of both sides of the wall and attracts the second strong magnetic block 68 inside the connecting cylinder 65 across the space. The strong magnetic attraction forces the second strong magnetic block 68 to slide on the inner wall of the connecting cylinder 65 and overcome the pre-tightening force of the guide spring 69 to compress and store energy. The sliding of the second strong magnetic block 68 synchronously drives the telescopic rod 67 fixedly connected to it to retract, thereby allowing the front of the second strong magnetic block 68 to move forward. The end face is completely separated from the inlet of the external connecting pipe 64; this mechanical linkage opens the originally blocked fluid path, allowing the cooling medium to first enter the inner cavity of the middle connecting cylinder 65 from the external connecting pipe 64, and then flow into the input pipe 66 without obstruction. Next, it is pressed into the starting section of the equidistant spiral cooling inner pipe 84 through the coolant inlet pipe 85. After the fluid flows along the equidistant spiral cooling inner pipe 84 to the end and overflows, it flows back along the cavity between the equidistant spiral cooling outer pipe 83 and the inner pipe for heat exchange. The waste liquid after heat exchange is collected in the cooling return outer pipe 82, and finally discharged outside the mold through the cooling drain pipe 81. This complete flow process realizes the pre-adjustment of the mold forming cavity for circulating cooling before formal injection molding, ensuring that the mold is in the optimal initial forming temperature field.

[0054] Step Two: When the mold pre-adjustment is completed and the injection molding process begins, external current is introduced through the power-taking post 52 located on the side wall of the injection head 51 and supplied to the electromagnet 53. The electromagnet 53 generates a strong magnetic field, and the magnetic force causes the magnetic boss 55 located in its inner hole to slide in the direction of overcoming the resistance of the return spring 56. The magnetic boss 55 drives the guide post 54 to move synchronously, causing the protruding part of the magnetic boss 55 to disengage and open the injection port 57. At the same time, the axial displacement of the magnetic boss 55 is rigidly transmitted through the linkage rod 62 on the side wall, causing the first strong magnetic block 63 at the end of the linkage rod 62 to slide synchronously away from the lower mold 2 and the second strong magnetic block 68 in the side hollow block 61. As the distance between the two increases... As the magnetic attraction between the first strong magnetic block 63 and the second strong magnetic block 68 rapidly diminishes until it disappears, the second strong magnetic block 68, now free from magnetic traction, is driven by the elastic restoring force released by the guide spring 69 to quickly return to its original position along the guide trajectory of the telescopic rod 67. This causes the front end face of the second strong magnetic block 68 and its high-temperature resistant rubber sealing gasket to re-close tightly against and physically press against the inlet of the external connecting pipe 64, blocking the opening from the connecting cylinder 65 to the external connecting pipe 64. At the moment of high-pressure filling of the plastic melt, the supply of coolant is rigidly cut off by mechanical linkage to prevent a sharp increase in melt viscosity and a large increase in flow resistance due to a sudden drop in cavity temperature during this stage, thereby ensuring that the melt can smoothly fill the fine structure of the pump head.

[0055] Step 3: Simultaneously with the injection port 57 open, an external power source supplies power to the equidistant shaped heating element 75 through the power input port 76, generating heat that is conducted to the pipe walls of the double-opening distribution pipe 71 and the equidistant shaped ring 73. The high-pressure plastic melt is injected from the injection port 57, first directly entering the inlet 72 in the middle of the docking double-opening distribution pipe 71. Under the guidance of the internal streamlined flow divider cone, it is smoothly divided to the left and right sides, and then enters the equidistant shaped ring 73 that precisely surrounds the cavity on both sides for envelope flow. Finally, it is simultaneously injected into the molding cavity through multiple outlets 74. This process eliminates heat loss of the melt in the flow channel through equidistant heating compensation, and completely changes the flow deviation problem of single-point injection by using multi-point injection, significantly improving the overall homogeneity and structural strength of the pump head product.

[0056] Step 4: After the cavity filling is completed, the power supply to the tap 52 is cut off, causing the magnetic field of the electromagnet 53 to disappear instantly. Under the strong axial thrust released by the return spring 56, the magnetic boss 55 quickly returns to its original position along the guide post 54, and its micro-arc spherical structure at the front end is tightly pressed into the chamfered conical surface of the inner edge of the injection port 57. The principle of this action is that when the micro-arc spherical surface and the chamfered conical surface meet, a line contact seal is formed, so that the thrust of the return spring 56 is converted into extremely high pressure on this contact line. This mechanical forced extrusion does not... Not only was the feed flow completely cut off, but the residual molten material at the front end, which was not yet fully solidified, was also subjected to high-pressure deep extrusion into the molding cavity, achieving "secondary pressure compensation" and effectively eliminating material porosity and shrinkage defects at the gate location. At the same time, the forward reset action of the magnetic boss 55, through the linkage rod 62, caused the first strong magnetic block 63 to move back to the trigger position close to the second strong magnetic block 68. The magnetic attraction was re-established and overcame the guide spring 69 to pull the second strong magnetic block 68 away, the external connecting pipe 64 was reopened, and the cooling medium flowed again along the... The external connecting pipe 64 first enters the inner cavity of the middle connecting cylinder 65, then flows unobstructed into the input pipe 66, and then is pressed into the initial section of the equidistant spiral cooling inner pipe 84 through the coolant inlet pipe 85. At this time, the low-temperature coolant that has just entered the equidistant spiral cooling inner pipe 84 will pass through its pipe wall to pre-cool the high-temperature return coolant inside the equidistant spiral cooling outer pipe 83 near the cooling return outer pipe 82, which is about to be discharged from the mold, for secondary cooling and heat exchange. Then the cooling medium continues to flow along the spiral trajectory of the equidistant spiral cooling inner pipe 84 to its far end and from... The end opening overflows into the cavity between the equidistant spiral cooling inner tube 84 and the equidistant spiral cooling outer tube 83. Then, under the constraint of the tube wall of the equidistant spiral cooling outer tube 83, the cooling medium flows back from far to near along the equidistant spiral path that precisely surrounds the pump head cavity. During the reverse flow process, it fully absorbs the heat conducted by the plastic melt in the molding cavity. The heat-exchange waste liquid finally collects into the two symmetrically arranged cooling return outer tubes 82 and is introduced into the cooling drain pipe 81 fixedly connected to the lower mold core 4 to be discharged outside the mold.

[0057] Step 5: After cooling and solidification for a set time, the injection molding machine pulls the upper mold 1 and drives the upper mold core 3 and injection head 51 to open the mold as a whole. During the physical stroke of mold opening, the side hollow block 61 fixed on the side of the injection head 51 moves away from the central connecting cylinder 65 and gradually moves away from the central connecting cylinder 65 fixed on the lower mold 2. As the distance increases, the magnetic constraint force of the first strong magnetic block 63 on the second strong magnetic block 68 is released. At this time, the second strong magnetic block 68 located inside the central connecting cylinder 65 is once again completely controlled by the pushing force of the guide spring 69 and automatically moves along the telescopic rod 67. The springback causes the end face to tightly press against the inlet of the external connecting pipe 64, cutting off the fluid source from the external connecting pipe 64. The mechanical action of mold opening is directly used as the ultimate trigger signal to cut off the cooling water circuit. No additional electrical control is required, which fundamentally prevents the coolant from dripping or splashing at the joint surface during the separation of the upper mold 1 and the lower mold 2. This keeps the mold parting surface and the workshop environment absolutely dry and clean. Then, the ejection mechanism on the lower mold core 4 ejects the shaped cooling oil pump plastic pump head, and the system safely enters the ready state for the next injection cycle.

[0058] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. An injection mold based on a plastic pump head of a cooling oil pump, characterized in that: include: Upper mold (1), the inner wall of which is provided with upper mold core (3); The lower mold (2) has a lower mold core (4) on its inner wall. Injection mechanism (5), which is set on the upper mold core (3), is used to perform injection molding when the upper mold (1) and the lower mold (2) are closed; A homogenizing mechanism (7) is provided on the lower mold core (4) for uniformly injecting molten material; A ring-shaped cooling mechanism (8) is disposed on the lower mold (2) and is used to uniformly cool the molten material after injection molding. The ring-shaped cooling mechanism (8) includes: A cooling drain pipe (81) is fixedly connected to the lower mold core (4). Two cooling return outer pipes (82) are fixedly connected to the cooling drain pipe (81). One end of the two cooling return outer pipes (82) away from the cooling drain pipe (81) is connected to an equidistant spiral cooling outer pipe (83). An equidistant spiral cooling inner pipe (84) is fixedly connected to the inner wall of the equidistant spiral cooling outer pipe (83). The equidistant spiral cooling inner pipe (84) communicates with the inner wall of the equidistant spiral cooling outer pipe (83). A coolant inlet pipe (85) is fixedly connected to the equidistant spiral cooling inner pipe (84). The coolant inlet pipe (85) is fixedly connected to the inner wall of the cooling return outer pipe (82). Triggering mechanism (6), which is set on the upper mold core (3) and the lower mold core (4), is used to trigger the annular cooling mechanism (8) during injection molding.

2. The injection mold based on a plastic pump head of a cooling oil pump according to claim 1, characterized in that: The injection molding mechanism (5) includes an injection head (51), which is fixedly connected to the upper mold core (3). A power-collecting post (52) is provided on the side wall of the injection head (51). The power-collecting post (52) penetrates the side wall of the injection head (51) and is fixedly connected to the injection head (51). An electromagnet (53) is fixedly connected to the power-collecting post (52). The electromagnet (53) is located inside the injection head (51), and a guide post (54) is provided through the inner wall of the electromagnet (53). The guide post (54) is slidably connected to the inner wall of the electromagnet (53). A magnetic boss (55) is fixedly connected to the end of the guide post (54) away from the electromagnet (53). A return spring (56) is connected between the magnetic boss (55) and the electromagnet (53). The end of the injection head (51) is provided with an injection port (57). The inner wall of the injection port (57) is initially blocked by the magnetic boss (55). The protruding part of the magnetic boss (55) is initially inserted into the inner wall of the injection port (57).

3. The injection mold based on a plastic pump head of a cooling oil pump according to claim 2, characterized in that: The triggering mechanism (6) includes a side hollow block (61), which is disposed on the side of the injection head (51). A linkage rod (62) is fixedly connected to the side wall of the magnetic boss (55). A first strong magnet (63) is fixedly connected to the end of the linkage rod (62) away from the magnetic boss (55). An external connecting pipe (64) is fixedly connected to the inner wall of the lower mold (2). A middle connecting cylinder (65) is fixedly connected to the external connecting pipe (64). An input pipe (66) is fixedly connected to the side wall of the middle connecting cylinder (65). A telescopic rod is fixedly connected to the inner wall of the middle connecting cylinder (65). 67), a second strong magnetic block (68) is fixedly connected to the side of the telescopic rod (67) away from the inner wall of the middle connecting cylinder (65). A guide spring (69) is connected between the second strong magnetic block (68) and the inner wall of the middle connecting cylinder (65). In the initial state, the second strong magnetic block (68) is tightly attached to the outer connecting pipe (64) under the action of the guide spring (69). The input pipe (66) penetrates the inner wall of the cooling drain pipe (81) and is fixedly connected to the inner wall of the cooling drain pipe (81). The coolant inlet pipe (85) is connected to the end of the input pipe (66) away from the middle connecting cylinder (65).

4. The injection mold based on a plastic pump head of a cooling oil pump according to claim 2, characterized in that: The homogenizing mechanism (7) includes a double-opening material distribution pipe (71), which is fixedly connected to the lower mold core (4). The middle part of the double-opening material distribution pipe (71) is provided with a material inlet (72). Two equidistant irregular rings (73) are symmetrically arranged on both sides of the double-opening material distribution pipe (71). The equidistant irregular rings (73) precisely surround the plastic pump head forming cavity. Several material outlets (74) are provided on the inner wall of the equidistant irregular rings (73).

5. An injection mold based on a plastic pump head of a cooling oil pump according to claim 4, characterized in that: The double-opening feed pipe (71) is fixedly connected to the outer wall of the equidistant irregular ring (73) with an equidistant irregular heating plate (75), and the equidistant irregular heating plate (75) is provided with a power supply port (76).

6. An injection mold based on a plastic pump head of a cooling oil pump according to claim 2, characterized in that: At least two sets of anti-friction oil grooves are provided on the outer circumferential surface of the guide column (54), and a self-lubricating bushing corresponding to the position of the anti-friction oil groove is embedded in the inner wall of the electromagnet (53).

7. An injection mold based on a plastic pump head of a cooling oil pump according to claim 2, characterized in that: The front end face of the protrusion of the magnetic boss (55) is processed into a micro-arc spherical structure, and the inner edge of the injection port (57) is provided with a chamfered cone surface that is adapted to the micro-arc spherical structure.

8. An injection mold based on a plastic pump head of a cooling oil pump according to claim 3, characterized in that: The second strong magnetic block (68) has a high-temperature resistant rubber sealing gasket attached to one end face near the external connecting pipe (64). The sealing gasket forms a flexible fit with the water inlet of the external connecting pipe (64) under the pressure of the guide spring (69).

9. An injection mold based on a plastic pump head of a cooling oil pump according to claim 5, characterized in that: The internal flow channel of the double-opening feed pipe (71) is provided with a streamlined flow divider cone at the part where it turns from the feed inlet (72) to the two equidistant irregular rings (73). The flow divider cone smoothly guides the vertically entering melt to the horizontal sides.

10. An injection molding method based on an injection mold for a cooling oil pump plastic pump head, characterized in that: The injection mold applied to the plastic pump head based on the cooling oil pump as described in any one of claims 1-9 further includes the following injection molding method: Step 1: The mold closing action begins. The upper mold (1) moves the upper mold core (3) to move closer to the lower mold (2) and the lower mold core (4). During this mold closing stroke, the side hollow block (61) fixed on the side of the injection head (51) descends until the side hollow block (61) and the connecting cylinder (65) fixed on the inner wall of the lower mold (2) are spatially precisely fitted. At this time, the magnetic field generated by the first strong magnetic block (63) inside the side hollow block (61) penetrates the wall thickness on both sides and attracts the second strong magnetic block (68) inside the connecting cylinder (65) across the space. The strong magnetic attraction forces the second strong magnetic block (68) to slide on the inner wall of the connecting cylinder (65) and overcome the pre-tightening force of the guide spring (69) to compress and store energy. The sliding of the second strong magnetic block (68) synchronously drives the telescopic rod (67) fixedly connected to it to retract, thereby making the second The front end of the strong magnetic block (68) is completely separated from the inlet of the external connecting pipe (64); this mechanical linkage opens the originally blocked fluid path, allowing the cooling medium to enter the inner cavity of the middle connecting cylinder (65) from the external connecting pipe (64), and then flow into the input pipe (66) without obstruction. Then, it is pressed into the starting section of the equidistant spiral cooling inner tube (84) through the coolant inlet pipe (85). The fluid flows along the equidistant spiral cooling inner tube (84) until it overflows at the end, and then flows back along the cavity between the equidistant spiral cooling outer tube (83) and the inner tube for heat exchange. The heat exchanged waste liquid is collected in the cooling return outer tube (82) and finally discharged outside the mold through the cooling drain pipe (81). This complete flow process realizes the pre-adjustment of the mold forming cavity for circulating cooling before formal injection molding, ensuring that the mold is in the optimal initial forming temperature field. Step 2: When the mold pre-adjustment is completed and the injection molding process begins, external current is introduced through the power take-up post (52) set on the side wall of the injection head (51) and supplied to the electromagnet (53). The electromagnet (53) generates a strong magnetic field when energized. The magnetic force causes the magnetic boss (55) located in its inner hole to overcome the resistance of the return spring (56) and slide in the direction. The magnetic boss (55) drives the guide post (54) to move synchronously, so that the protruding part of the magnetic boss (55) disengages and opens the injection port (57). At the same time, the axial displacement of the magnetic boss (55) is rigidly transmitted through the linkage rod (62) on the side wall, which drives the first strong magnetic block at the end of the linkage rod (62). (63) Slide synchronously in the side hollow block (61) away from the lower mold (2) and the second strong magnetic block (68); as the distance between the two increases, the magnetic attraction of the first strong magnetic block (63) to the second strong magnetic block (68) rapidly decreases to disappear. The second strong magnetic block (68), which loses magnetic traction, is driven by the elastic restoring force released by the guide spring (69) and quickly resets forward along the guide trajectory of the telescopic rod (67), so that the front end face of the second strong magnetic block (68) and the high temperature resistant rubber sealing gasket on it re-close tightly and physically press against the water inlet of the external connecting pipe (64), blocking the opening of the middle connecting cylinder (65) to the external connecting pipe (64); Step 3: When the injection port (57) is opened, the external power supply supplies power to the equidistant shaped heating element (75) through the power input port (76), generating heat that is conducted to the pipe wall of the double-opening distribution pipe (71) and the equidistant shaped ring (73); the high-pressure plastic melt is injected from the injection port (57), first directly into the inlet (72) in the middle of the docking double-opening distribution pipe (71), and smoothly divided to the left and right sides under the guidance of the internal streamlined flow divider cone, and then enters the equidistant shaped ring (73) that precisely surrounds the cavity on both sides for envelope flow, and finally is injected into the molding cavity simultaneously through multiple outlets (74); Step 4: After the cavity is filled, the power supply to the power take-off column (52) is cut off, causing the magnetic field of the electromagnet (53) to disappear instantly. Under the strong axial thrust released by the return spring (56), the magnetic boss (55) quickly moves forward along the guide column (54) to reset and impact. The micro-arc spherical structure at its front end is tightly pressed into the chamfered cone surface of the inner edge of the injection port (57). At the same time, the forward reset action of the magnetic boss (55) drives the first strong magnetic block (63) to move back to the trigger position close to the second strong magnetic block (68) through the linkage rod (62). The magnetic attraction is re-established and overcomes the guide spring (69) to pull the second strong magnetic block (68). The external connecting pipe (64) is unblocked again. The cooling medium enters the inner cavity of the middle connecting cylinder (65) along the external connecting pipe (64) and then flows into the input pipe (66) without obstruction. Then it is pressed into the starting section of the equidistant spiral cooling inner tube (84) through the coolant inlet pipe (85). At this time, The low-temperature coolant that just enters the equidistant spiral cooling inner tube (84) will pass through its tube wall to pre-cool the high-temperature reflux coolant that is about to be discharged from the mold inside the equidistant spiral cooling outer tube (83) near the cooling return outer tube (82). Then the cooling medium continues to flow along the spiral trajectory of the equidistant spiral cooling inner tube (84) to its far end and overflows from the end opening into the cavity between the equidistant spiral cooling inner tube (84) and the equidistant spiral cooling outer tube (83). Then, under the constraint of the tube wall of the equidistant spiral cooling outer tube (83), the cooling medium flows back from far to near along the equidistant spiral path that precisely surrounds the pump head cavity. During the reverse flow process, it fully absorbs the heat conducted by the plastic melt in the molding cavity. The heat-exchange waste liquid is finally collected in the two symmetrically arranged cooling return outer tubes (82) and introduced into the cooling drain pipe (81) fixedly connected to the lower mold core (4) to be discharged outside the mold. Step 5: After cooling and solidification for a set time, the injection molding machine pulls the upper mold (1) and drives the upper mold core (3) and injection head (51) to open the mold as a whole. During the physical stroke of mold opening, the side hollow block (61) fixed on the side of the injection head (51) moves away from the middle connecting cylinder (65) and gradually moves away from the middle connecting cylinder (65) fixed on the lower mold (2). As the distance increases, the magnetic constraint force of the first strong magnetic block (63) on the second strong magnetic block (68) is released. At this time, the second strong magnetic block (68) located inside the middle connecting cylinder (65) is once again completely controlled by the thrust of the guide spring (69) and automatically rebounds along the telescopic rod (67), so that its end face tightly presses the water inlet of the external connecting pipe (64) and cuts off the fluid source from the external connecting pipe (64).

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