Direct-pressure balance die locking device and die-casting machine

Abstract

Disclosed in the present invention is a direct-pressure balance die locking device, which comprises a fixed die plate, a movable die plate and a rear die plate. The movable die plate and the rear die plate are slidingly arranged on a frame and are connected to the fixed die plate by means of a group of pull rods. A direct-pressure balance locking mechanism is arranged between the rear die plate and the movable die plate. The direct-pressure balance locking mechanism comprises a high-pressure oil cylinder assembly and a balance locking assembly which are arranged in a split mode, the high-pressure oil cylinder assembly being arranged on the rear die plate and providing a direct-pressure die locking force, and the balance locking assembly being arranged on the movable die plate so as to provide a radial balance locking supporting force for the high-pressure oil cylinder assembly. The distribution position of the high-pressure oil cylinder assembly on the rear die plate and the connecting positions of the pull rods on the rear die plate are staggered. Also disclosed is a die-casting machine. During a die locking process, the direct-pressure balance die locking device enables die plates to be uniformly stressed and conveniently adjusted, and a small diameter design for cylinders can be achieved while the locking force is kept unchanged, thereby avoiding oil leakage and achieving low cost and wide applications. The present invention can be widely applied to production and processing of metal die-casting for molten metals at a high temperature of 700-800℃.

Description

Direct pressure balanced clamping device and die casting machine Technical Field

[0001] The present invention relates to the technical field of die casting, in particular to a direct pressure balanced die locking device and a die casting machine. Background Art

[0002] Currently, the most widely used clamping mechanism for die-casting machines is the toggle-type clamping and locking mechanism. Crankshaft-type three-platen presses present challenges. Because the force is applied to the upper and lower parts of the die platen, this creates uneven stress on the die platen. Poor lubrication at the crankshaft joints can lead to wear and burnout of the pins and sleeves. Consequently, these issues include uneven stress on the die platen, with greater stress on the upper and lower parts of the die platen during clamping, and less stress on the sides. Poorly designed or properly lubricated crankshaft sleeves and pins can lead to burnout. This can also cause issues such as mold adjustment failures in very large die-casting machines.

[0003] The pure two-platen structure presents design challenges for ultra-large die-casting machines. The large cylinder diameter places high demands on seals, leading to oil leakage and high maintenance costs. Specifically, the locking cylinder piston, where it connects to the brake nut, has a rearward shift in gravity, creating a tilting tendency that can easily cause oil leakage. Furthermore, the locking cylinder passes through a large lever, resulting in a larger cylinder diameter.

[0004] Therefore, it is urgent to design a direct pressure balanced clamping device that can achieve uniform force, no oil leakage, small cylinder diameter design, and can achieve balanced, continuous and stable clamping.

[0005] Summary of the Invention

[0006] The purpose of the present invention is to solve the problems of uneven force on the existing template, easy jamming of the mold during adjustment, immovability of the mold during adjustment, large cylinder diameter, easy oil leakage of the cylinder, and high cost, and to provide a direct pressure balanced clamping device and a die-casting machine with uniform force on the template, convenient mold adjustment, small cylinder diameter design under the premise of unchanged locking force, and no oil leakage.

[0007] The technical solution adopted by the present invention to achieve the first invention object is: a direct pressure balanced clamping device, comprising:

[0008] Fixed template, movable template and rear template;

[0009] The movable platen is slidably arranged on the frame to cooperate with the fixed platen to achieve mold closing and mold opening;

[0010] The rear template is slidingly arranged on a frame outside the movable template;

[0011] The movable template and the rear template are connected to the fixed template via a set of tie rods;

[0012] A straight pressure balancing locking mechanism is provided between the rear template and the movable template;

[0013] The direct pressure balanced locking mechanism includes a split high-pressure cylinder assembly and a balanced locking assembly. The high-pressure cylinder assembly is arranged on the rear template and provides direct pressure clamping force. The balanced locking assembly is arranged on the movable template and provides radial balanced locking support force for the high-pressure cylinder assembly.

[0014] The distribution position of the high-pressure oil cylinder assembly on the rear template is staggered with the connection position of the pull rod on the rear template.

[0015] The direct pressure balanced locking device, through a new design of the locking mechanism, arranges the direct pressure balanced locking mechanism in a split manner on the rear template and the dynamic template, wherein the axis of the high-pressure cylinder assembly is perpendicular to the plate surface of the rear template and is arranged on the rear template, for providing a direct pressure clamping force to the dynamic template, and the balanced locking assembly is perpendicular to the axis of the high-pressure cylinder assembly and is arranged on the dynamic template, providing a radial balanced locking support force to the high-pressure cylinder assembly. Such a structure enables the high-pressure cylinder assembly to provide a uniform and stable clamping force to the template during the mold closing and clamping process, and uneven force on the template will not occur during the clamping process. Since the setting position of the high-pressure cylinder assembly is offset from the connection position of the pull rod on the rear template, the high-pressure cylinder assembly does not pass through the pull rod. Therefore, the cylinder diameter of the high-pressure cylinder assembly can be designed with a small cylinder diameter according to the implementation needs. Under the premise of the same clamping force requirement, the cylinder diameter of the high-pressure cylinder can be designed to be smaller, with good sealing performance and not easy to leak oil. At the same time, during the mold adjustment process, since the balanced locking assembly provides radial locking force to the high-pressure cylinder assembly, the balanced locking assembly first radially locks the high-pressure cylinder assembly, and the high-pressure cylinder assembly drives the movable mold to move toward the rear mold plate to achieve mold adjustment, making mold adjustment more convenient and preventing the phenomenon of mold jamming and difficulty in adjusting the mold. This direct pressure balanced mold locking device ensures uniform force on the mold plate during the mold locking process, making mold adjustment convenient. Under the premise of maintaining the locking force, the cylinder diameter can be designed with a small cylinder diameter, without oil leakage, low cost, and wide application. It can be widely used in the production and processing needs of metal die casting with molten metal high temperature of 700-800℃.

[0016] Preferably, the high-pressure cylinder assembly includes a high-pressure cylinder and a locking connector for cooperating with the balanced locking assembly to achieve balanced locking. The high-pressure cylinder assembly is provided with a high-pressure cylinder and a locking connector provided on the high-pressure cylinder. The locking connector is used to lock the high-pressure cylinder. During the mold clamping process, the extended end of the piston rod is supported by a balanced and stable supporting force, which can ensure the stability of the mold clamping and prevent the occurrence of mold clamping instability during the mold clamping process.

[0017] Preferably, the high-pressure oil cylinder comprises a cylinder body and a piston rod. A rodless cavity and a rod cavity are provided within the high-pressure oil cylinder, communicating with the hydraulic cylinder. At least two seals are provided at the junction of the piston rod and the cylinder body, forming an annular cavity between the cylinder body and the piston rod. To improve the sealing performance of the high-pressure oil cylinder, at least two seals are provided at the junction of the piston rod and the cylinder body to prevent oil from leaking from the front end of the cylinder.

[0018] Preferably, the high-pressure oil cylinder is provided with an oil return structure. To prevent oil leakage from the front end of the high-pressure oil cylinder during long-term use, the oil return structure is provided inside the high-pressure oil cylinder. The oil return structure returns the leaked hydraulic oil to the interior of the high-pressure oil cylinder, thereby preventing oil leakage from the front end and ensuring the stability of the clamping force of the high-pressure oil cylinder.

[0019] Preferably, the oil return structure includes an oil return channel opened between the two seals and connected to the annular cavity and the rod cavity respectively, and a one-way valve is provided on the oil return channel. The oil return structure mainly includes an oil return channel opened between the two seals, the oil return channel is connected to the annular cavity and the rod cavity respectively, and a one-way valve is provided at one end of the oil return channel close to the rod cavity. During the use of the high-pressure oil cylinder, the oil inside the rod cavity leaks toward the seal along the axial direction of the piston rod. When the oil flows through the first seal and enters the annular cavity, a certain pressure will be formed in the annular cavity, and then it will pass through the second seal and leak to the front end of the cylinder. Therefore, in order to prevent the occurrence of oil leakage, an oil return channel is opened on the cylinder body where the annular cavity is located. When the oil enters the annular cavity, the oil will flow along the oil return channel through the one-way valve and return to the rod cavity, effectively preventing the occurrence of oil leakage.

[0020] Preferably, the locking connector is provided at the protruding end of the piston rod, and a locking ring groove is provided on the locking connector. When the mold is to be closed and locked, the balancing locking assembly on the movable platen is actuated to lock the locking connector on the high-pressure oil cylinder on the rear platen, providing a radially balanced and stable supporting force for the high-pressure oil cylinder. The rear platen and the movable platen then move together toward the fixed platen. When the movable platen is in contact with the mold, the high-pressure oil cylinder is actuated to achieve mold locking.

[0021] Preferably, the piston rod is provided with an inner cavity, an inner piston rod is provided within the inner cavity, and the locking connector is provided at the extended end of the inner piston rod, forming an internal and external dual control structure. To achieve more effective high-pressure locking force, the inner piston rod is provided within the piston rod. This internal and external dual control structure achieves a high and stable locking force during the mold clamping process.

[0022] Preferably, the axis of the high-pressure cylinder assembly is arranged perpendicular to the rear template, and the axis of the balanced locking assembly is arranged perpendicular to the axis of the high-pressure cylinder assembly. The high-pressure cylinder assembly is arranged in a cross shape on the rear template, so that the template is more evenly stressed. The high-pressure cylinder assembly and the tie rod connection hole are staggered to achieve a small cylinder diameter design for the high-pressure cylinder assembly. Moreover, the axis of the high-pressure cylinder assembly is arranged perpendicular to the rear template, and the axis of the balanced locking assembly is arranged perpendicular to the axis of the high-pressure cylinder assembly, which is more conducive to the balanced locking assembly providing radial balanced locking support force to the high-pressure cylinder assembly.

[0023] Preferably, the balanced locking assembly includes a balanced locking cylinder and a clamping gate. The piston rod of the balanced locking cylinder is connected to the clamping gate; the clamping gate is provided with a gate hole for engaging and locking with the high-pressure cylinder assembly. The balanced locking assembly preferably comprises a balanced locking cylinder and a clamping gate, which offers a simple structure and convenient operation. Locking is achieved by engaging the gate hole with the locking ring groove on the locking connector, providing good stability.

[0024] The technical solution adopted by the present invention to achieve its second invention purpose is: a die-casting machine, including the direct pressure balanced clamping device.

[0025] The die-casting machine with a direct pressure balanced clamping device has uniform clamping force, convenient mold adjustment, no oil leakage, low cost, and wide application, and can be particularly widely used in the production and processing needs of metal die-casting with molten metal at a high temperature of 700-800°C.

[0026] The beneficial effects of the present invention are: during the clamping process, the template is evenly stressed and mold adjustment is convenient. Under the premise of unchanged locking force, the cylinder diameter can be designed with a small cylinder diameter, there is no oil leakage, low cost, and wide application. It can be widely used in particular for the production and processing needs of metal die-casting with molten metal at a high temperature of 700-800°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG1 is a schematic structural diagram of a direct pressure balanced clamping device of the present invention;

[0028] FIG2 is a cross-sectional view of the direct pressure balanced clamping device of the present invention;

[0029] FIG3 is a top view of the direct pressure balanced clamping device of the present invention;

[0030] Figure 4 is an enlarged view of point A in Figure 2;

[0031] FIG5 is a distribution structure diagram of the high-pressure cylinder assembly on the rear template of the present invention;

[0032] FIG6 is a distribution structure diagram of a balancing locking assembly on a movable platen of the present invention;

[0033] FIG7 is a right side view of the movable template in FIG6;

[0034] FIG8 is a schematic structural diagram of a high-pressure oil cylinder in the present invention;

[0035] FIG9 is a cross-sectional view of a high-pressure oil cylinder of the present invention;

[0036] 10 is a hydraulic oil circuit control diagram of the high-pressure cylinder of the present invention;

[0037] FIG11 is a schematic structural diagram of a high-pressure oil cylinder in Example 2 of the present invention;

[0038] 12 is a hydraulic oil circuit control diagram of the high-pressure cylinder in Example 2 of the present invention;

[0039] In the figure: 1, frame, 2, sliding guide rail, 3, fixed platen, 4, movable platen, 5, platen slide foot, 6, rear platen, 61, tie rod through hole, 7, direct pressure balance locking mechanism, 8, fixed platen brake mechanism, 9, rear platen brake mechanism, 10, bottom-mounted mold shifting cylinder, 11, tie rod, 12, high-pressure cylinder assembly, 13, balance locking assembly, 14, high-pressure cylinder, 15, locking connector, 16, piston rod, 17, cylinder rear cover, 18, cylinder Sleeve, 19. Cylinder front cover, 20. Piston, 21. Piston chamber, 22. Rodless chamber, 23. Rod chamber, 24. Seal, 25. Oil return channel, 25-1. Radial oil channel, 25-2. Axial oil channel, 26. One-way valve, 27. Inner chamber, 28. Locking ring groove, 29. Balanced locking cylinder, 30. Holding gate, 31. Gate hole, 32. Inner piston, 33. Inner piston rod, 34. Balanced connection, 35. Sealing ring sleeve, 36. Annular chamber. DETAILED DESCRIPTION

[0040] The various aspects of the present invention are described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0041] Example 1:

[0042] In the embodiments shown in Figures 1, 2, and 3, a direct pressure balanced mold locking device eliminates the crankshaft structure and adopts a direct pressure balanced locking mechanism between the movable platen and the rear platen to achieve high-pressure mold locking.

[0043] This direct pressure balanced mold clamping device comprises a frame 1 with a sliding guide rail 2 mounted on it. A fixed platen 3 is fixed to one end of the frame 1, and a movable platen 4 is positioned opposite the fixed platen 3. The movable platen 4 is mounted on the frame 1 via a platen slide 5 and slides along the sliding guide rail 2. A rear platen 6 is mounted on the frame 1 outside the movable platen 4. The fixed platen 3, movable platen 5, and rear platen 6 are connected by a set of tie rods 11. The movable platen 4 cooperates with the fixed platen 3 to achieve mold closing and opening.

[0044] The direct pressure balanced locking mechanism 7 includes a split high-pressure cylinder assembly 12 and a balanced locking assembly 13. The high-pressure cylinder assembly 12 is arranged on the rear mold plate 6 and provides a direct pressure clamping force. The balanced locking assembly 13 is arranged on the movable mold plate 4 to provide a radial balanced locking support force for the high-pressure cylinder assembly 12.

[0045] The distribution position of the high-pressure oil cylinder assembly 12 on the rear template 6 is staggered with the connection position of the pull rod on the rear template 6 .

[0046] A fixed platen brake mechanism 8 is provided on the fixed platen 3. A rear platen brake mechanism 9 is provided on the rear platen 6.

[0047] A lower mold shifting cylinder 10 is provided at the bottom of the frame 1 and is connected to the movable mold plate 4 for driving the movable mold plate 4 to move.

[0048] The movable platen 4 and the rear platen 6 are pushed to move together by the lower mold shifting oil cylinder 10. The rear platen 6 and the movable platen 4 move simultaneously when opening and closing the mold.

[0049] As shown in FIG4 , a direct pressure balancing locking mechanism 7 is provided between the rear template 6 and the movable template 4 .

[0050] As shown in Figure 5, the direct pressure balanced locking mechanism 7 includes a high-pressure cylinder assembly 12 and a balanced locking assembly 13. The high-pressure cylinder assembly 12 is arranged on the side of the rear template 6 facing the movable template 4. In this embodiment, the rear template is a square structure, and tie rod through holes 61 are provided on the four corners of the rear template. The high-pressure cylinder assembly is arranged in the middle of the four sides of the rear template 6. The high-pressure cylinder assembly 12 is arranged in four groups in a square structure on the rear template 6. The four groups of high-pressure cylinder assemblies 12 are staggered with the tie rods 11. In this embodiment, the tie rod through holes 61 of the four groups of tie rods on the rear template are arranged at the four corners, while the four groups of high-pressure cylinder assemblies are distributed in the middle of the four sides. Such a design structure can make the template more evenly stressed and can achieve a stable and effective clamping force.

[0051] As shown in FIG8 and FIG9 , the high-pressure oil cylinder assembly 12 includes a high-pressure oil cylinder 14 and a locking connector 15 for cooperating with the balanced locking assembly 13 to achieve balanced locking.

[0052] The high-pressure oil cylinder assembly 12 includes a high-pressure oil cylinder 14 and a locking connector 15 provided on the high-pressure oil cylinder 14 .

[0053] The high-pressure oil cylinder 14 includes a cylinder body and a piston rod 16. A rodless chamber 22 and a rod chamber 23 are provided inside the high-pressure oil cylinder 14, which communicate with the hydraulic cylinder. At least two seals 24 are provided at the connection between the piston rod 16 and the cylinder body. An annular chamber is formed between the cylinder body and the piston rod 16 between the seals 24. An oil return structure is provided inside the high-pressure oil cylinder 14.

[0054] The piston rod 16 of the high-pressure oil cylinder 14 is arranged perpendicular to the rear template 6, and the high-pressure oil cylinder 14 is embedded in the rear template 6. The cylinder body of the high-pressure oil cylinder 14 includes a cylinder rear cover 17, a cylinder sleeve 18 and a cylinder front cover 19. A piston 20 is integrally arranged on the piston rod 16. A piston chamber 21 is formed between the cylinder rear cover 17, the cylinder sleeve 18 and the cylinder front cover 19. The piston 20 is sealingly and slidingly arranged inside the piston chamber 21. A rodless chamber 22 and a rod chamber 23 are formed between the piston 20 and the piston chamber 21. At least two seals 24 are provided at the sealing fit between the piston rod 16 and the cylinder front cover 19. A return oil structure connected to the rod chamber 23 is provided on the cylinder front cover 19 between the two adjacent seals 24. The oil return structure includes an oil return channel 25 and a one-way valve 26. A one-way valve 26 is provided between the oil return channel 25 and the rod chamber 23 to prevent leakage. In this embodiment, the oil return passage 25 includes a radial oil passage 25 - 1 provided along the radial direction of the cylinder front cover and an axial oil passage 25 - 2 provided along the axial direction of the cylinder front cover.

[0055] The piston rod 16 is internally defined with an inner cavity 27, and the locking connector 15 is mounted on the protruding end of the piston rod 16. The locking connector 15 is provided with a locking ring groove 28 for cooperating with the balanced locking assembly 13 to achieve locking. The piston rod 16 of the high-pressure cylinder 14 is positioned perpendicular to the surface of the rear mold plate 6. The locking ring groove 28 also facilitates locking of the high-pressure cylinder piston rod, thereby providing radially balanced locking support for the high-pressure cylinder, ensuring precise and stable mold closing.

[0056] As shown in Figures 6 and 7, the movable platen has a square structure, and the balancing locking assembly 13 is divided into the middle position of the four sides of the movable platen corresponding to the high-pressure cylinder assembly. The balancing locking assembly 13 includes a balancing locking cylinder 29 and a clamping gate 30. The piston rod of the balancing locking cylinder 29 is connected to the clamping gate 30, and the axis of the balancing locking cylinder 29 is arranged perpendicular to the axis of the high-pressure cylinder piston rod 16. The clamping gate 30 is provided with a gate hole 31, and the gate hole 31 cooperates with the locking ring groove 28 on the locking connector 15 to achieve locking. The locking connector 15 is inserted into the gate hole 31, and the locking ring groove 28 cooperates with the gate hole 31, and locking is achieved by the balancing locking cylinder 29.

[0057] The direct pressure balance locking mechanism 7 is a split setup, with the high-pressure cylinder 14 located on the rear platen 6 and the balance locking assembly 13 located on the dynamic platen 4. Furthermore, the positions of the direct pressure balance locking mechanism are arranged in a square structure, resulting in a smaller diameter of the locking cylinder of a die-casting machine of the same tonnage than a pure two-platen structure of the same tonnage.

[0058] As shown in Figure 10, during the mold adjustment process, after the mold is positioned, the balancing locking cylinder 29 is actuated to lock the locking ring groove 28 on the locking connector 15. That is, the balancing locking cylinder 29 drives the clamping gate 30 to clamp the locking connector 15 on the high-pressure cylinder, connecting the movable platen to the rear platen, and realizing that the rear platen drives the movable platen to move. Then, the lower mold shifting cylinder 10 pushes the rear platen 6 and the movable platen 4 together to move toward the fixed platen 3. After the movable platen 4 is fitted with the mold, the high-pressure cylinder 14 pushes the rear platen 6 backward to stabilize the rear platen 6 to the set mold adjustment position. After the position is adjusted, the rear platen brake mechanism 9 on the rear platen 6 clamps the pull rod, and then the mold closing operation can be carried out.

[0059] During the mold closing and clamping process, the rear mold plate 6 is pushed to the designated position by the high-pressure cylinder 14. During the clamping process, a certain starting pressure exists in the rodless cavity 22 within the high-pressure cylinder 14, while there is no pressure in the annular cavity 36 formed by the seal between the piston rod 16 and the cylinder cover plate 19. At this time, the piston rod 16 moves stably toward the movable mold plate 4, providing high-pressure clamping force to the movable mold plate 4. During the movement of the piston rod 16, if the oil in the rod cavity 23 leaks toward the seal 24 along the piston rod and the cylinder front cover, a certain pressure will be generated within the annular cavity 36. In severe cases, this can lead to oil leakage in the high-pressure cylinder. Specifically, with long-term use, the oil will leak between the first and second seals, further flow between the second and third seals, and finally flow axially out of the cylinder front cover. This affects both the stable operation of the piston rod and the stability of the clamping force. To address this issue, an oil return passage 25 connecting to the rod chamber 23 is provided between the first and second seals, and a one-way valve 26 is installed on this passage. During use, if hydraulic oil passes through the seals and enters the annular chamber 36, it will flow back into the rod chamber 23 through the oil return passage 25 and the one-way valve 26. This prevents leakage from the cylinder front cover along the axial direction of the piston rod 16, nor does it build up pressure within the annular chamber. This achieves an oil-tight design for the cylinder front chamber and ensures stable clamping force. Because hydraulic oil does not leak along the cylinder front chamber and does not build up pressure between the seals, the high-pressure cylinder 14 operates more smoothly during the clamping process, achieving a more effective clamping force.

[0060] During the mold closing and locking process, the rear template 6 and the movable template 4 are pushed toward the fixed template 3 by the lower mold shifting cylinder 10. At this time, the high-pressure cylinder is locked by the balanced locking assembly, and the rear template 6 pushes the movable template to move together. After the movable template 4 is fitted with the mold, it and the fixed template 3 close the mold; the high-pressure cylinder is actuated to provide high-pressure locking force. Since the balanced locking cylinder 29 applies a radial locking force to the locking connector 15 on the piston rod 16, the locking connector has a radially balanced and stable support. Therefore, the high-pressure cylinder 14 can provide a continuous and stable locking force to the movable template during the mold closing and locking process.

[0061] During the mold opening process, the high-pressure cylinder 14 releases pressure, that is, the pressure inside the rodless chamber 22 is released, and the piston rod 16 drives the locking connector 15 to move toward the side of the rear template to unlock the mold, and then the rear template 6 and the movable template 4 are pushed back by the lower mold shifting cylinder 10 to realize mold opening.

[0062] During the mold clamping process, the lower-mounted mold-shifting cylinder 10 pushes the rear platen and movable platen to close the mold. Simultaneously, the high-pressure cylinder pushes the rear platen to the designated position. The fixed platen brake mechanism 8 on the fixed platen 3 then clamps the tie rod 11, locking the fixed platen. The high-pressure cylinder piston rod then pushes the movable platen to lock the mold. Simultaneously, the rear platen brake mechanism 9 on the rear platen 6 clamps the tie rod, locking the rear platen.

[0063] When the mold is opened, the high-pressure locking cylinder releases pressure, the rear template brake mechanism 9 is released, and the lower mold-moving cylinder pushes the rear template and the movable template back. At the same time, the fixed template brake mechanism 8 is released to realize mold opening.

[0064] This direct-pressure balanced clamping device offers more uniform clamping force, easier mold adjustment, and smoother movement. It has a wide range of applications, particularly meeting the production and processing needs of metal die-casting processes involving molten metal temperatures of 700-800°C. Compared to the same tonnage locking cylinder, the diameter of this high-pressure cylinder can be smaller, resulting in a faster locking response.

[0065] A die-casting machine includes the direct pressure balanced clamping device described in this embodiment.

[0066] Example 2:

[0067] In the embodiments shown in FIG11 and FIG12 , a direct pressure balanced clamping device is provided, and its technical solution is basically the same as that of embodiment 1, except that:

[0068] The high-pressure oil cylinder 14 adopts an internal and external dual control structure. An inner cavity 27 is provided inside the piston rod 16, and an inner piston 32 is provided inside the inner cavity 27. An inner piston rod 33 with a diameter slightly smaller than that of the inner piston is integrally provided on the inner piston 32. The protruding end of the inner piston rod 33 is provided with a balancing connection part 34. The diameter of the balancing connection part 34 matches the diameter of the protruding end of the piston rod 16. The locking connector 15 is installed on the balancing connection part 34 of the inner piston rod 32. A dynamic seal is achieved between the inner piston rod 33 and the inner cavity 27 through a sealing ring sleeve 35. In this embodiment, an inner piston rod 32 is provided inside the high-pressure oil cylinder, and a stable clamping structure is formed between the inner piston rod and the piston rod. Due to the provision of the inner piston rod, the high-pressure oil cylinder applies a dynamically adjusted and continuous stable clamping force to the movable mold plate during the clamping process, thereby achieving stable and continuous clamping. The setting of the inner piston and the inner piston rod is to facilitate the mold adjustment and pressure stabilization operation. Through this internal and external dual control structure, the design of the high-pressure cylinder with small cylinder diameter and large locking force is realized. It has a wide range of applications and can meet the production and processing needs of metal die-casting with molten metal high temperature of 700-800℃.

[0069] The high-pressure oil cylinder adopts an internal and external dual control structure. Through the internal and external dual hydraulic control, the small-diameter design of the high-pressure oil cylinder can be achieved. The diameter of the high-pressure oil cylinder can be greatly reduced, and at the same time, the clamping force can be greatly improved.

[0070] The high-pressure oil cylinder is locked, and the locking connector 15 is inserted into the gate hole 31 , and the balanced locking oil cylinder 29 is actuated to lock the locking ring groove 28 on the locking connector 15 .

[0071] During the mold closing and locking process, the rear mold plate 6 and the movable mold plate 4 are pushed toward the fixed mold plate 3 by the lower mold shifting cylinder 10, and the movable mold plate 4 and the fixed mold plate 3 close the mold.

[0072] During high-pressure clamping, a certain opening pressure exists within the rodless cavity 22 of the high-pressure oil cylinder 14, pushing the piston rod 16 toward the movable platen 4. The piston rod 16 pushes the movable platen 4 to perform the clamping operation. While the piston rod 16 drives the inner piston rod 33 and the locking connector 15 to achieve high-pressure clamping, the inner piston rod 32 actuates, driving the locking connector 15 on it toward the movable platen. This allows for adjustment of the clamping force balance, ensuring stable force during the clamping process and reliable locking. The high-pressure oil cylinder assembly provides a continuous and stable clamping force to the movable platen during the mold closing and clamping process, meeting the clamping force design requirements for large molds.

[0073] During the mold opening process, the high-pressure cylinder 14 releases pressure, and the inner piston rod and the outer piston rod release pressure at the same time. The piston rod 16 drives the inner piston rod and the locking connector 15 to move toward the side of the rear template to unlock the mold. Then, the rear template 6 and the movable template 4 are pushed back by the lower mold shifting cylinder 10 to realize mold opening.

[0074] During the mold clamping process, the lower mold-shifting cylinder 10 pushes the rear platen and the movable platen to close the mold. Simultaneously, the high-pressure cylinder pushes the rear platen to the specified position, and the fixed platen brake mechanism 8 on the fixed platen 3 clamps the tie rod 11, achieving the clamping operation on the fixed platen side. The high-pressure cylinder piston rod then pushes the movable platen to lock the rear platen mold. Simultaneously, the high-pressure cylinder locks the mold, and the rear platen brake mechanism 9 on the rear platen 6 clamps the tie rod, achieving the clamping operation on the rear platen side.

[0075] When the mold is opened, the high-pressure locking cylinder releases pressure, the rear template brake mechanism 9 is released, and the lower mold-moving cylinder pushes the rear template and the movable template back. At the same time, the fixed template brake mechanism 8 is released to realize mold opening.

[0076] A die-casting machine includes the direct pressure balanced clamping device described in this embodiment.

[0077] The direct-pressure balanced mold-locking device described in the above embodiment incorporates a direct-pressure balanced locking mechanism between the rear platen and the movable platen. High-pressure cylinder assembly 12 and balanced locking assembly 13 are separately located on the rear platen and the movable platen. This split direct-pressure balanced locking mechanism allows simultaneous mold opening and closing of the rear platen 5 and the movable platen 4. Furthermore, the direct-pressure balanced locking mechanism adopts a square structure, ensuring uniform force on the plates during mold closing and locking. This ensures high clamping force, convenient mold adjustment, and excellent clamping and mold opening linkage, particularly for ultra-large die-casting machines. Furthermore, the provision of an oil return line and a one-way valve ensures that the front end of the cylinder is leak-proof.

[0078] It should be noted that the above embodiments are merely illustrative of the principles of the present invention. Various variations and improvements are possible without departing from the scope of the present invention, and all such variations and improvements fall within the scope of the claimed invention. Based on the embodiments described herein, all other embodiments derived by persons of ordinary skill in the art on the basis of the technical solutions of this application without inventive effort shall fall within the scope of protection of the present invention.

Claims

1. A direct pressure balanced clamping device, characterized in that include: A fixed template (3), a movable template (4) and a rear template (6); The movable platen (4) and the rear platen (6) are slidably arranged on the frame (1) and connected to the fixed platen (3) via a set of tie rods; A straight pressure balancing locking mechanism (7) is provided between the rear template (6) and the movable template (4); The direct pressure balanced locking mechanism (7) comprises a split high-pressure oil cylinder assembly (12) and a balanced locking assembly (13), wherein the high-pressure oil cylinder assembly (12) is arranged on the rear mold plate (6) and provides a direct pressure mold locking force, and the balanced locking assembly (13) is arranged on the movable mold plate (4) to provide a radial balanced locking support force for the high-pressure oil cylinder assembly (12); wherein: The distribution position of the high-pressure oil cylinder assembly (12) on the rear template (6) is offset from the pull rod connection position on the rear template (6).

2. The direct pressure balanced clamping device according to claim 1, characterized in that: The high-pressure oil cylinder assembly (12) comprises a high-pressure oil cylinder (14) and a locking connector (15) for cooperating with a balancing locking assembly (13) to achieve balancing locking.

3. The direct pressure balanced clamping device according to claim 2, characterized in that: The high-pressure oil cylinder (14) comprises a cylinder body and a piston rod (16); a rodless chamber (22) and a rod chamber (23) connected to the hydraulic cylinder are arranged inside the high-pressure oil cylinder (14); at least two seals (24) are arranged at the joint between the piston rod (16) and the cylinder body; an annular chamber (36) is formed between the cylinder body and the piston rod (16) between the seals (24).

4. The direct pressure balanced clamping device according to claim 3 is characterized in that: An oil return structure is arranged inside the high-pressure oil cylinder (14).

5. The direct pressure balanced clamping device according to claim 4, characterized in that: The oil return structure comprises an oil return passage (25) opened between two sealing elements (24) and respectively connected to the annular cavity (36) and the rod cavity (23), and a one-way valve (26) is arranged on the oil return passage (25).

6. The direct pressure balanced clamping device according to claim 3, characterized in that: The locking connector (15) is arranged at the protruding end of the piston rod (16), and a locking ring groove (28) is arranged on the locking connector (15).

7. The direct pressure balanced clamping device according to claim 3 is characterized in that: The piston rod (16) is provided with an inner cavity (27), an inner piston rod (33) is provided inside the inner cavity (27), the locking connector (15) is provided at the protruding end of the inner piston rod (33), and the inner piston rod (33) and the piston rod (16) form an inner and outer dual control structure.

8. The direct pressure balanced clamping device according to any one of claims 1 to 7, characterized in that: The axis of the high-pressure oil cylinder assembly (12) is arranged perpendicularly to the rear template (6), and the axis of the balancing locking assembly (13) is arranged perpendicularly to the axis of the high-pressure oil cylinder assembly (12).

9. The direct pressure balanced clamping device according to any one of claims 1 to 7, characterized in that: The balancing locking assembly (13) comprises a balancing locking cylinder (29) and a clamping gate plate (30); the piston rod of the balancing locking cylinder (29) is connected to the clamping gate plate (30); and the clamping gate plate (30) is provided with a gate plate hole (31) for cooperating with the high-pressure cylinder assembly (12) for locking.

10. A die casting machine, characterized in that: It comprises the direct pressure balanced clamping device as described in any one of claims 1 to 9.

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