Die core-pulling structure with extrusion pin

Abstract

A mold comprises a fixed mold insert, a fixed mold sleeve plate and a core pulling assembly with the extrusion pin structure, and the core pulling assembly comprises an extrusion pin rod, a rod sleeve, a first sleeve, a second sleeve, a movable block and an extrusion cylinder used for pushing the extrusion pin rod to move axially, one end of the extrusion pin rod is matched with an inner hole of the rod sleeve and is in sliding connection with the rod sleeve in the axial direction, the other end of the extrusion pin rod is fixedly connected to the movable block, the movable block is located in the second sleeve and is in threaded connection with the inner wall of the second sleeve, and the second sleeve is in sliding sealing connection with the inner wall of the first sleeve. The extrusion pin rod of the mold core-pulling assembly can linearly enter the mold when the casting liquid is extruded, the extrusion pin rod can rotationally retreat from the mold after the casting liquid is solidified, the relative position between the extrusion pin rod and a casting is changed, and the risk of adhesion to casting metal when the extrusion pin rod retreats from the mold is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of die casting, and in particular to a die core pulling belt extrusion pin structure. Background Art

[0002] Die casting is a method of obtaining castings by filling the die casting mold with liquid metal at a high speed under high pressure, and forming and solidifying under pressure. The extrusion pin is an important structure in the die casting mold. During the die casting process, the main function of the extrusion pin is to send the casting liquid to the dead corner position in the mold cavity to ensure the integrity and surface quality of the casting. At the same time, the extrusion pin can also be used to alleviate and remove shrinkage defects in specific areas inside the casting. Of course, the extrusion pin can also be used to form the precasting hole of the casting to reduce the later processing allowance at the precasting hole.

[0003] In the prior art, the extrusion pin and the pin sleeve are used together, and the extrusion pin moves axially inside the pin sleeve to complete the action of pressing the extrusion pin into the casting liquid and withdrawing from the casting. Since the extrusion pin is in direct contact with the metal casting liquid, the metal casting liquid wraps the extrusion pin after solidification. When the extrusion pin withdraws from the casting through linear axial movement, the extrusion pin pulls the casting metal, and the metal is easy to adhere to the surface of the extrusion pin, affecting the axial movement of the extrusion pin inside the pin sleeve, resulting in abnormal noise in the mold and jamming of the extrusion pin. Summary of the invention

[0004] In order to solve the problem that the extrusion pin is prone to sticking to metal when it is linearly withdrawn from the casting, the present invention proposes a mold core pulling structure with an extrusion pin, which enables the extrusion pin to be rotatably withdrawn from the casting. The extrusion pin rotates relative to the casting to change the relative position between the casting and the extrusion pin, thereby reducing the situation where the extrusion pin sticks to metal during demolding.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A mold core pulling with extrusion pin structure, the core pulling assembly includes an extrusion pin, a rod sleeve and an extrusion cylinder for driving the extrusion pin to move axially, the extrusion cylinder is fixedly connected to the fixed mold sleeve, the rod sleeve is fixedly arranged on the fixed mold insert, the fixed mold sleeve is fixedly connected to the fixed mold insert, the extrusion pin matches the inner hole of the rod sleeve and is axially slidably connected to the rod sleeve, and is characterized in that the core pulling assembly also includes a coaxially arranged first sleeve, a second sleeve and a movable block, the movable block is located inside the second sleeve and is threadedly connected to the inner wall of the second sleeve, the threaded connection is used to realize a rotational action when the movable block moves axially relative to the second sleeve, and the second sleeve is slidingly and sealingly connected to the inner wall of the first sleeve; the two end faces of the second sleeve are sealed, and the first sleeve is sealed near an end face of the rod sleeve, the first end portion of the extrusion pin is fixedly connected to the second end of the movable block, and the second end of the extrusion pin sequentially passes through the second end face of the second sleeve and the end face of the first sleeve and extends to the inside of the rod sleeve.

[0006] The working end of the extrusion cylinder is fixedly connected to the first end of the push-pull rod, the second end of the push-pull rod passes through the first end surface of the second sleeve and is rotatably connected to the first end of the movable block, the push-pull rod is provided with a first limit plate, the first limit plate is located below the first end surface of the second sleeve, and the first limit plate is used to push the second sleeve to move so as to move the second sleeve from the first position to the second position. A second elastic member is provided between the first end of the movable block and the first end surface of the second sleeve, and the second elastic member is used to push the second sleeve to move so as to move the second sleeve from the second position to the first position.

[0007] Preferably, the inner wall of the second sleeve is provided with an internal thread, the outer wall of the movable block is provided with an external thread matching the internal thread, and the helix angle between the internal thread and the external thread is greater than 45°.

[0008] Preferably, the fixed mold sleeve is provided with a first limit block for limiting the second sleeve at the second position and a second limit block for releasing the limit of the second sleeve at the second position.

[0009] Preferably, the second end of the first limit block is connected to the fixed mold sleeve through the first telescopic elastic body, the second end of the second limit block is connected to the fixed mold sleeve through the second telescopic elastic body, and the second limit block is fixedly connected to the first limit block through a connecting rod to form a synchronous movement perpendicular to the axis direction of the second sleeve. A limit groove is arranged on the outside of the second sleeve, and when the second sleeve is in the second position, the first end of the first limit block enters the limit groove to form a limit to the second sleeve; a second limit plate is arranged on the push-pull rod, and when the movable block is in the third position, the second limit plate contacts the first end of the second limit block and pushes the second limit block to move in a direction away from the second sleeve, and the first end of the first limit block leaves the limit groove to release the limit to the second sleeve.

[0010] Preferably, the first telescopic elastic body includes a first telescopic rod and a first elastic member, the first elastic member is coaxially sleeved on the outside of the first telescopic rod, and the axes of the first telescopic rod and the first elastic member are respectively perpendicular to the axis of the second sleeve.

[0011] Preferably, a first inclined surface is provided at the first end of the second limit block, a second inclined surface is provided at one end of the second limit plate relative to the second limit block, the second inclined surface is arranged opposite to the first inclined surface, the second inclined surface of the second limit plate is always located above the first inclined surface of the second limit block, and when the movable block is located at the third position, the second inclined surface of the second limit plate is in contact with the first inclined surface of the second limit block.

[0012] Preferably, a limiting sleeve is provided inside the first sleeve, the limiting sleeve is located below the first position of the second sleeve, and the limiting sleeve is used to limit the position of the second sleeve when the second sleeve moves from the second position to the first position.

[0013] Preferably, a first liquid cavity is provided between the second end faces of the first sleeve and the second sleeve, a second liquid cavity is provided inside the extrusion pin, the second liquid cavity is connected to the first liquid cavity, and the first liquid cavity and the second liquid cavity are used to contain cooling medium.

[0014] Preferably, a cooling pipe is provided outside the first sleeve, and the cooling pipe is used to cool the first sleeve.

[0015] Preferably, a first fixed tube for connecting to the first liquid chamber is provided on the end surface of the first sleeve, a second fixed tube for connecting to the second liquid chamber is provided on one side of the extrusion pin, and the first fixed tube and the second fixed tube are connected via a hose.

[0016] The beneficial effects of the present invention are: 1. The extrusion pin rod of the core pulling assembly in the core pulling and extrusion pin structure of the mold can enter the mold during the metal casting to form a precast hole on the die casting model, and at the same time extrude the metal casting to compensate for the shrinkage position of the casting that is prone to shrinkage.

[0017] 2. When the extrusion pin of the core-pulling extrusion pin structure of the mold enters the mold, the extrusion cylinder pushes the movable block from the first position to the second position, so that the extrusion pin enters the mold in a straight line, which is convenient for controlling the speed at which the extrusion pin enters the mold; after the molten metal solidifies, the extrusion cylinder pulls the movable block from the second position to the first position, and the movable block can rotate relative to the second sleeve, so that the extrusion pin can rotate to exit the mold. The extrusion pin rotates relative to the casting, changing the relative position between the casting and the extrusion pin, thereby reducing the risk of the extrusion pin sticking to the casting metal when exiting the mold.

[0018] 3. The extrusion pin rod of the core-pulling extrusion pin structure of the mold is provided with a second liquid cavity, which is filled with a cooling medium to cool the extrusion pin rod, reduce the damage of the high-temperature casting liquid to the anti-sticking agent on the surface of the extrusion pin rod, maintain the effectiveness of the anti-sticking agent on the surface of the extrusion pin rod, and reduce the probability of adhesion on the surface of the extrusion pin rod. The cooling medium flows between the second liquid cavity of the extrusion pin rod and the first liquid cavity of the first sleeve, and intermittent cooling of the cooling medium is performed to maintain the effective cooling capacity of the cooling medium inside the extrusion pin rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of the core-pulling belt extrusion pin structure of the mold; Figure 2 This is a structural schematic diagram of the first sleeve of the core-pulling belt extrusion pin structure of the mold; Figure 3 This is a schematic diagram of the cross section of the first sleeve at AA of the core-pulling structure with extrusion pin of the mold; Figure 4 This is a schematic diagram of the cross section of the first sleeve BB of the core-pulling structure with extrusion pin of the mold; Figure 5 This is a structural schematic diagram of the extrusion pin structure of the core-pulling mold when the extrusion pin enters the mold; Figure 6 This is a structural schematic diagram of the extrusion pin structure of the core-pulling mold during the process of the extrusion pin exiting the mold; Figure 7 This is a structural schematic diagram of the core-pulling belt extrusion pin structure of the mold when the extrusion pin is completely withdrawn from the mold (the second sleeve has not returned to its position).

[0020] In the figure: 1, fixed mold insert; 2, fixed mold sleeve; 3, casting liquid; 4, first sleeve; 5, second sleeve; 6, movable block; 7, push-pull rod; 8, extrusion pin rod; 9, rod sleeve; 10, first limit plate; 11, first limit block; 12, second limit block; 13, extrusion cylinder; 14, second elastic member; 15, second limit plate; 16, hose; 17, connecting rod; 18, limit sleeve; 19, precast hole; 21. Mounting groove; 22. Cooling tube; 41. First liquid cavity; 51. Internal thread; 52. Limiting groove; 53. Chamber; 61. External thread; 81. Second liquid cavity; 91. Accommodating groove; 111. First telescopic elastic body; 121. Second telescopic elastic body; 1111. First telescopic rod; 1112. First elastic member. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0022] Reference Figure 1-2 A core-pulling mold with an extrusion pin structure, the mold includes a fixed mold insert 1, a fixed mold sleeve 2 and a core-pulling assembly with an extrusion pin structure, the fixed mold sleeve 2 is fixedly connected to the fixed mold insert 1, the fixed mold insert 1 is used to directly contact the casting liquid 3, and the core-pulling assembly with the extrusion pin structure is installed on the fixed mold insert 1 and the fixed mold sleeve 2 of the mold. The core-pulling assembly includes an extrusion pin rod 8, a rod sleeve 9, a first sleeve 4, a second sleeve 5, a movable block 6 and an extrusion cylinder 13. The fixed mold insert 1 is fixedly provided with a rod sleeve 9, and the fixed mold sleeve 2 is fixedly provided with an extrusion cylinder 13, and the extrusion cylinder 13 is used to drive the extrusion pin rod 8 to move axially. The extrusion pin rod 8 is coaxially arranged with the rod sleeve 9, the extrusion pin rod 8 is located in the inner hole of the rod sleeve 9, the extrusion pin rod 8 matches the inner hole of the rod sleeve 9 and is axially slidably connected with the rod sleeve 9. The tolerance clearance between the extrusion pin rod 8 and the rod sleeve 9 directly affects the production continuity and the service life of the extrusion pin. Generally, the larger the tolerance of the extrusion pin and the pin sleeve, the larger the gap, and the extrusion pin sleeve is easy to get stuck by the casting liquid. The size of the extrusion pin rod 8 is set according to the size of the precast hole 19, and the gap between the extrusion pin rod 8 and the rod sleeve 9 is maintained at 0.05-0.11mm.

[0023] refer to Figure 2 The extrusion pin 8, rod sleeve 9, first sleeve 4, second sleeve 5 and movable block 6 are coaxially arranged. The first sleeve 4 is fixedly embedded in the fixed mold sleeve 2. The second sleeve 5 is located inside the first sleeve 4 and matches the inner hole of the first sleeve 4. The second sleeve 5 is axially slidably connected to the first sleeve 4. A sealing ring is arranged between the side wall of the second sleeve 5 and the inner wall of the first sleeve 4 to achieve a sliding sealing connection between the second sleeve 5 and the first sleeve 4. The two end faces of the second sleeve 5 are sealed, and the end face of the second sleeve 5 close to the rod sleeve 9 is the second end face, and the end face of the second sleeve 5 away from the rod sleeve 9 is the first end face. One end face of the first sleeve 4 close to the rod sleeve 9 is also sealed, which can limit the axial movement of the second sleeve 5.

[0024] For further reference, Figure 2 and Figure 3 , the movable block 6 is located inside the chamber 53 of the second sleeve 5, the inner wall of the chamber 53 of the second sleeve 5 is provided with an internal thread 51, the outer wall of the movable block 6 is provided with an external thread 61 matching the internal thread 51, and the movable block 6 is threadedly connected with the second sleeve 5. When the movable block 6 moves axially relative to the second sleeve 5, the movable block 6 can also rotate relative to the second sleeve 5. In this embodiment, the helix angle between the internal thread 51 and the external thread 61 is greater than 45°, the self-locking ability between the internal thread 51 and the external thread 61 is not strong, and relative movement is easy to occur, thereby facilitating the relative movement of the movable block 6 and the second sleeve 5.

[0025] refer to Figure 2 The working end of the extrusion cylinder 13 is connected to the movable block 6 through the push-pull rod 7, the first end of the push-pull rod 7 is fixedly connected to the working end of the extrusion cylinder 13, and the second end of the push-pull rod 7 passes through the first end surface of the second sleeve 5 and is rotatably connected to the first end of the movable block 6. The first end of the extrusion pin 8 is fixedly connected to the second end of the movable block 6, and the second end of the extrusion pin 8 passes through the second end surface of the second sleeve 5 and the end surface of the first sleeve 4 in sequence and extends to the inside of the rod sleeve 9. The extrusion cylinder 13 pushes the movable block 6 upward or pulls it downward through the push-pull rod 7, so that the movable block 6 moves axially, realizing the action of the extrusion pin 8 entering or exiting the mold.

[0026] The second sleeve 5 has a corresponding first position and a second position. The movable block 6 has a corresponding third position and a fourth position. Figure 1 , the third position of the movable block 6 and the first position of the second sleeve 5 are both at the lower limit position. At this time, the movable block 6 is located at the upper part of the cavity 53 of the second sleeve 5, and the extrusion pin 8 is completely retracted into the rod sleeve 9 and is not inside the mold. Figure 5, the fourth position of the movable block 6 and the second position of the second sleeve 5 are both at the upper limit position, at which time the movable block 6 is still located at the upper part of the chamber 53 of the second sleeve 5, the second end of the extrusion pin 8 extends from the rod sleeve 9, and the part of the extrusion pin 8 used to form the precast hole 19 is completely located inside the mold, and the precast hole 19 is extruded inside the casting liquid 3. At the same time, the extrusion pin 8 can extrude the casting liquid 3 to compensate for the shrinkage of the position where the shrinkage cavity is easily formed in the casting.

[0027] Furthermore, a first limit plate 10 is fixedly disposed on the push-pull rod 7, and the first limit plate 10 is located below the first end surface of the second sleeve 5. Figure 1 , Figure 2 and Figure 5 When the second sleeve 5 is located in the first position and the movable block 6 is located in the third position, the first limit plate 10 contacts the first end surface of the second sleeve 5, and the extrusion cylinder 13 pushes the push-pull rod 7 upward, and the push-pull rod 7 directly pushes the movable block 6 and the extrusion pin 8 to move upward. The first limit plate 10 is used to push the second sleeve 5 upward to achieve synchronous movement of the second sleeve 5 and the movable block 6, so that the second sleeve 5 moves from the first position to the second position, the movable block 6 moves from the third position to the fourth position, and the second end of the extrusion pin 8 enters the casting liquid 3.

[0028] refer to Figure 2 and Figure 3 The fixed mold sleeve 2 is provided with a first limit block 11 for limiting the second sleeve 5 at the second position. The first end of the first limit block 11 is a free end. The second end of the first limit block 11 is connected to the fixed mold sleeve 2 through a first telescopic elastic body 111. The first telescopic elastic body 111 is used to elastically support the first limit block 11. A limit groove 52 is provided on the outside of the second sleeve 5. When the second sleeve 5 is at the second position, under the pushing action of the first telescopic elastic body 111, the first end of the first limit block 11 enters the limit groove 52 of the second sleeve 5 to limit the second sleeve 5.

[0029] refer to Figure 3 In this embodiment, the first telescopic elastic body 111 includes a first telescopic rod 1111 and a first elastic member 1112. The first elastic member 1112 is coaxially sleeved on the outside of the first telescopic rod 1111. The first telescopic rod 1111 is used to support the first elastic member 1112 from the inside of the first elastic member 1112 to reduce the bending and twisting of the first elastic member 1112. The axes of the first telescopic rod 1111 and the first elastic member 1112 are respectively perpendicular to the axis of the second sleeve 5. One end of the first telescopic rod 1111 and the first elastic member 1112 is fixedly connected to the fixed mold sleeve 2, and the other end of the first telescopic rod 1111 and the first elastic member 1112 is fixedly connected to the first limit block 11. The fixed mold sleeve 2 is provided with a first slideway to accommodate the sliding of the first limit block 11.

[0030] Furthermore, the fixed mold sleeve 2 is also provided with a second limit block 12 for releasing the limit of the second sleeve 5 in the second position. The first end of the second limit block 12 is a free end, and the second end of the second limit block 12 is connected to the fixed mold sleeve 2 through a second telescopic elastic body 121. The structure of the second telescopic elastic body 121 is the same as that of the first telescopic elastic body 111. The second telescopic elastic body 121 is used to elastically support the second limit block 12. The fixed mold sleeve 2 is provided with a second slideway to accommodate the sliding of the second limit block 12. The second limit block 12 is fixedly connected to the first limit block 11 through a connecting rod 17, and the second limit block 12 and the first limit block 11 can move synchronously in a direction perpendicular to the axis of the second sleeve 5.

[0031] A second limit plate 15 is provided on the push-pull rod 7. When the movable block 6 moves from the fourth position to the third position, the second limit plate 15 contacts the first end of the second limit block 12 and pushes the second limit block 12 to move away from the second sleeve 5. The first limit block 11 and the second limit block 12 can move synchronously, so that the first end of the first limit block 11 leaves the limit groove 52 of the second sleeve 5, thereby releasing the limit on the second sleeve 5.

[0032] refer to Figure 2 The first end of the second limit block 12 is provided with a first inclined surface, and the second limit plate 15 is provided with a second inclined surface at one end opposite to the second limit block 12, and the second inclined surface is arranged opposite to the first inclined surface. The second inclined surface of the second limit plate 15 is always located above the first inclined surface of the second limit block 12. When the movable block 6 is located at the third position, the second inclined surface of the second limit plate 15 is in contact with the first inclined surface of the second limit block 12, so that the second limit plate 15 pushes the second limit block 12.

[0033] refer to Figure 2 A second elastic member 14 is disposed between the first end of the movable block 6 and the first end surface of the second sleeve 5. Figure 6 and Figure 7 , when the casting liquid 3 is solidified and formed, the extrusion pin 8 needs to exit the mold, and the movable block 6 needs to move from the fourth position to the third position. Since the second sleeve 5 is limited to the second position by the first limit block 11, the movable block 6 moves axially relative to the second sleeve 5 and generates a rotational motion, forming a rotational exit of the extrusion pin 8 from the mold, reducing the adhesion of the extrusion pin 8 to the metal on the surface of the casting when it exits. When the movable block 6 moves to the third position, the extrusion cylinder 13 stops working, and the movable block 6 is located at the lower part of the internal chamber 53 of the second sleeve 5. At this time, the second elastic member 14 is compressed, and the second limit plate 15 pushes the second limit block 12 and the first limit block 11 to move, so that the first end of the first limit block 11 leaves the limit groove 52 of the second sleeve 5, releasing the limit on the second sleeve 5. Since the position of the movable block 6 is fixed, under the action of the second elastic member 14, refer to Figure 7 and Figure 1The second sleeve 5 generates a rotational axial movement relative to the movable block 6 , and the second sleeve 5 moves from the second position to the first position until the first end surface of the second sleeve 5 contacts the first limiting plate 10 .

[0034] Furthermore, a limiting sleeve 18 is disposed inside the first sleeve 4, and the limiting sleeve 18 is fixedly connected to the inner wall of the first sleeve 4. The limiting sleeve 18 is located below the first position of the second sleeve 5, and when the second sleeve 5 is located at the first position, the limiting sleeve 18 contacts the first end surface of the second sleeve 5. The limiting sleeve 18 is used to assist in limiting the second sleeve 5 when the second sleeve 5 moves from the second position to the first position.

[0035] Before die casting, an anti-sticking agent is usually sprayed in the inner cavity of the mold to isolate the mold and the casting, reduce the adhesion of the casting to the mold, and facilitate demoulding of the casting. In order to facilitate the extrusion pin 8 to leave the casting, the extrusion pin 8 will also be sprayed with an anti-sticking agent before die casting. High temperature will affect the effect of the anti-sticking agent, so the mold is generally provided with a cooling component, such as a water cooling component or an oil cooling component, to balance the casting liquid temperature.

[0036] refer to Figure 2 and Figure 4 A first liquid cavity 41 is provided between the second end faces of the first sleeve 4 and the second sleeve 5, a first fixed tube for connecting the first liquid cavity 41 is provided on the end face of the first sleeve 4, a second liquid cavity 81 is provided inside the extrusion pin 8, a second fixed tube for connecting the second liquid cavity 81 is provided on one side of the extrusion pin 8, and the first fixed tube and the second fixed tube are connected through a hose 16. The hose 16 is a rubber hose, and the hose 16 is used to connect the second liquid cavity 81 with the first liquid cavity 41. The first liquid cavity 41 and the second liquid cavity 81 are used to contain cooling medium, and the cooling medium flows between the first liquid cavity 41 and the second liquid cavity 81. When the extrusion pin 8 extrude the casting liquid 3, the cooling medium is located inside the second liquid cavity 81, and the extrusion pin 8 is cooled, thereby reducing the damage of the anti-sticking agent on the surface of the extrusion pin 8 by high temperature, maintaining the effectiveness of the anti-sticking agent on the surface of the extrusion pin 8, and reducing the probability of adhesion on the surface of the extrusion pin 8.

[0037] In this embodiment, a receiving groove 91 is provided on one side of the rod sleeve 9 close to the first sleeve 4 , and the receiving groove 91 is used to receive the hose 16 . When the extrusion pin 8 moves relative to the rod sleeve 9 , the receiving groove 91 provides space for the hose 16 to move and deform.

[0038] Furthermore, a mounting groove 21 is provided on one side of the fixed mold sleeve 2 close to the rod sleeve 9, and a cooling pipe 22 is provided inside the mounting groove 21. The cooling pipe 22 is arranged outside the first sleeve 4, and the cooling pipe 22 is arranged close to the wall of the first sleeve 4, and the cooling pipe 22 is spirally wound outside the first sleeve 4. The cooling liquid is used to circulate inside the cooling pipe 22, and the cooling liquid can cool the first sleeve 4, and at the same time cool the cooling medium inside the first liquid cavity 41 in the first sleeve 4. When the extrusion pin 8 exits the mold, the second sleeve 5 moves from the second position to the first position, the volume of the first liquid cavity 41 increases to form a negative pressure, and the cooling medium in the second liquid cavity 81 inside the extrusion pin 8 enters the first liquid cavity 41, and the cooling medium is cooled inside the first liquid cavity 41, reducing the temperature of the cooling medium, realizing intermittent cooling of the cooling medium, and maintaining the effective cooling capacity of the cooling medium. When the extrusion pin 8 performs the next extrusion work, the cooling medium enters the second liquid cavity 81 of the extrusion pin 8 again for cooling.

[0039] In this embodiment, the cooling pipe 22 can be connected to the cooling component of the mold to achieve the sharing of the coolant in the cooling pipe 22 and the cooling component of the mold. For example, if the cooling component of the mold is an oil cooling component, the coolant is cooling oil. The liquid inlet end of the cooling pipe 22 is connected to the liquid outlet end of the oil pump, the liquid inlet end of the oil pump is connected to the cooling oil tank of the corresponding oil cooling component, and the liquid outlet end of the cooling pipe 22 is connected to the cooling oil tank of the corresponding oil cooling component. After the coolant completes the oil cooling work, it enters the cooling oil tank. The cooling oil tank is equipped with a heat exchanger to cool the coolant. The cooled coolant is sent to the cooling pipe 22 through the oil pump for cooling.

[0040] The working process of the mold core pulling belt extrusion pin structure in this embodiment includes the following steps: Step 1: Before the mold is injected with casting liquid 3, the various parts of the mold core are in the initial position, refer to Figure 1 and Figure 2 At this time, the second sleeve 5 is located at the first position, the movable block 6 is located at the third position, the first end surface of the second sleeve 5 is in contact with the first limit plate 10 and the limit sleeve 18 respectively, and the extrusion pin 8 is completely retracted into the rod sleeve 9 and is not inside the mold; Step 2: After the injection molding liquid 3 is completed inside the mold, after a few seconds, the extrusion cylinder 13 pushes the push-pull rod 7 upward, and the push-pull rod 7 directly pushes the movable block 6 and the extrusion pin 8 upward, and the first limit plate 10 pushes the second sleeve 5 upward to move, so that the second sleeve 5 and the movable block 6 move upward synchronously, refer to Figure 5 , the second sleeve 5 moves from the first position to the second position, the movable block 6 moves from the third position to the fourth position, the second end of the extrusion pin 8 linearly enters the casting liquid 3, and the precast hole 19 is squeezed inside the casting liquid 3. At the same time, the extrusion pin 8 can extrude the casting liquid 3 to compensate for the shrinkage of the position where the shrinkage cavity is easy to form in the casting; At this time, when the second sleeve 5 is located at the second position, the limiting groove 52 of the second sleeve 5 corresponds to the position of the first limiting block 11, and under the pushing action of the first telescopic elastic body 111, the first end of the first limiting block 11 enters the limiting groove 52 to limit the second sleeve 5; at the same time, the cooling medium enters the second liquid cavity 81 inside the extrusion pin 8 from the first liquid cavity 41 inside the first sleeve 4 to cool the extrusion pin 8, thereby maintaining the effectiveness of the anti-sticking agent on the surface of the extrusion pin 8 and reducing the probability of adhesion on the surface of the extrusion pin 8; Step 3: When the casting liquid 3 is solidified and formed, the extrusion pin 8 needs to be withdrawn from the mold. Figure 6 , the extrusion cylinder 13 pulls the push-pull rod 7 downward, and the movable block 6 needs to move from the fourth position to the third position. Since the second sleeve 5 is limited to the second position by the first limit block 11, the movable block 6 moves axially relative to the second sleeve 5 and generates a rotational motion, forming the extrusion pin 8 to rotate out of the mold, reducing the adhesion of the extrusion pin 8 to the metal on the surface of the casting when it is withdrawn; Step 4: Reference Figure 7 , when the movable block 6 moves to the third position, the extrusion pin 8 completely withdraws from the mold, the extrusion cylinder 13 stops working, and the movable block 6 is also located at the lower part of the internal chamber 53 of the second sleeve 5. At this time, the second elastic member 14 is in a compressed state; the second limiting plate 15 pushes the second limiting block 12 and the first limiting block 11 to move, so that the first end of the first limiting block 11 leaves the limiting groove 52 of the second sleeve 5, and the limiting of the second sleeve 5 is released. Since the position of the movable block 6 is fixed, under the action of the second elastic member 14, the second sleeve 5 produces a rotational axial movement relative to the movable block 6, and the second sleeve 5 moves from the second position to the first position until the first end face of the second sleeve 5 contacts the first limiting plate 10. At this time, the movable block 6, the second sleeve 5 and the extrusion pin 8 all return to their initial positions; At the same time, the volume of the first liquid chamber 41 increases to form a negative pressure, squeezing the cooling medium in the second liquid chamber 81 inside the pin 8 into the first liquid chamber 41, and the cooling medium can be cooled inside the first liquid chamber 41. The temperature of the cooling medium inside the first liquid chamber 41 decreases, achieving intermittent cooling of the cooling medium and maintaining the effective cooling capacity of the cooling medium. Step 5: demoulding the casting, and then spraying the anti-sticking agent inside the mold. When spraying the anti-sticking agent, keep the extrusion pin 8 in the state of entering the mold, and keep the extrusion pin 8 with the anti-sticking agent; Step 6: Keep the various components of the mold core pulling in the initial position, repeat step 2, and produce the next casting. When the extrusion pin 8 performs the next extrusion work, the cooling medium cooled inside the first liquid cavity 41 enters the second liquid cavity 81 of the extrusion pin 8 again for cooling.

[0041] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A mold core pulling structure with an extrusion pin, the core pulling assembly includes an extrusion pin rod, a rod sleeve and an extrusion cylinder for driving the extrusion pin rod to move axially, the extrusion cylinder is fixedly connected to the fixed mold sleeve, the rod sleeve is fixedly arranged on the fixed mold insert, the fixed mold sleeve is fixedly connected to the fixed mold insert, the extrusion pin rod matches the inner hole of the rod sleeve and is axially slidably connected to the rod sleeve, characterized in that: The core pulling assembly also includes a first sleeve, a second sleeve and a movable block which are coaxially arranged, the movable block being located inside the second sleeve and being threadedly connected to the inner wall of the second sleeve, the threaded connection being used to realize a rotational movement of the movable block when the movable block moves axially relative to the second sleeve, the second sleeve being slidingly and sealingly connected to the inner wall of the first sleeve; two end faces of the second sleeve are sealed, an end face of the first sleeve close to the rod sleeve is sealed, the first end portion of the extrusion pin is fixedly connected to the second end of the movable block, the second end of the extrusion pin sequentially passes through the second end face of the second sleeve and the end face of the first sleeve and extends to the inside of the rod sleeve; The working end of the extrusion cylinder is fixedly connected to the first end of the push-pull rod, the second end of the push-pull rod passes through the first end surface of the second sleeve and is rotatably connected to the first end of the movable block, and a first limit plate is arranged on the push-pull rod, the first limit plate is located below the first end surface of the second sleeve, and the first limit plate is used to push the second sleeve to move so as to realize the second sleeve moving from the first position to the second position; A second elastic member is disposed between the first end of the movable block and the first end surface of the second sleeve, and the second elastic member is used to push the second sleeve to move so as to realize the movement of the second sleeve from the second position to the first position.

2. The mold core-pulling belt extrusion pin structure according to claim 1, characterized in that: The inner wall of the second sleeve is provided with an internal thread, and the outer wall of the movable block is provided with an external thread matching the internal thread, and the helix angle between the internal thread and the external thread is greater than 45°.

3. The mold core-pulling belt extrusion pin structure according to claim 2 is characterized in that: The fixed mold sleeve is provided with a first limit block for limiting the second sleeve at the second position and a second limit block for releasing the limit of the second sleeve at the second position.

4. The mold core-pulling belt extrusion pin structure according to claim 3, characterized in that: The second end of the first limit block is connected to the fixed mold sleeve through the first telescopic elastic body, the second end of the second limit block is connected to the fixed mold sleeve through the second telescopic elastic body, and the second limit block is fixedly connected to the first limit block through a connecting rod to form a synchronous movement perpendicular to the axis direction of the second sleeve; A limiting groove is provided on the outside of the second sleeve. When the second sleeve is located at the second position, the first end of the first limiting block enters the limiting groove to form a limit for the second sleeve. A second limiting plate is provided on the push-pull rod. When the movable block is located at the third position, the second limiting plate contacts the first end of the second limiting block and pushes the second limiting block to move away from the second sleeve, and the first end of the first limiting block leaves the limiting groove to release the limit on the second sleeve.

5. The mold core-pulling belt extrusion pin structure according to claim 4, characterized in that: The first telescopic elastic body includes a first telescopic rod and a first elastic member, the first elastic member is coaxially sleeved on the outside of the first telescopic rod, and the axes of the first telescopic rod and the first elastic member are respectively perpendicular to the axis of the second sleeve.

6. The mold core-pulling belt extrusion pin structure according to claim 4, characterized in that: A first inclined surface is provided at the first end of the second limit block, a second inclined surface is provided at one end of the second limit plate opposite to the second limit block, the second inclined surface is arranged opposite to the first inclined surface, the second inclined surface of the second limit plate is always located above the first inclined surface of the second limit block, and when the movable block is located at the third position, the second inclined surface of the second limit plate is in contact with the first inclined surface of the second limit block.

7. The mold core-pulling belt extrusion pin structure according to any one of claims 1 to 6, characterized in that: A limiting sleeve is arranged inside the first sleeve, the limiting sleeve is located below the first position of the second sleeve, and the limiting sleeve is used to limit the position of the second sleeve when the second sleeve moves from the second position to the first position.

8. The mold core-pulling belt extrusion pin structure according to claim 7, characterized in that: A first liquid cavity is arranged between the second end faces of the first sleeve and the second sleeve, a second liquid cavity is arranged inside the extrusion pin, the second liquid cavity is connected to the first liquid cavity, and the first liquid cavity and the second liquid cavity are used to contain cooling medium.

9. The mold core-pulling belt extrusion pin structure according to claim 8, characterized in that: A cooling pipe is arranged outside the first sleeve, and the cooling pipe is used to cool the first sleeve.

10. The mold core-pulling belt extrusion pin structure according to claim 9, characterized in that: The end surface of the first sleeve is provided with a first fixed tube for connecting with the first liquid chamber, and one side of the extrusion pin is provided with a second fixed tube for connecting with the second liquid chamber. The first fixed tube and the second fixed tube are connected through a hose.

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