Hydraulic system with multi-oil-cylinder lock mode force control and die casting machine

Abstract

The utility model discloses a kind of hydraulic system and die casting machine of multi-oil cylinder mold locking force control, it is related to die casting equipment technical field, including locking mode oil cylinder, oil supply device, check valve, detection device and control device;Locking mode oil cylinder includes double-acting oil cylinder and single-acting oil cylinder;Oil supply device supplies oil to double-acting oil cylinder by first oil supply path;And oil supply device supplies oil to single-acting oil cylinder by second oil supply path;When oil supply device supplies oil to the rodless cavity of double-acting oil cylinder, oil supply device simultaneously supplies oil to the rodless cavity of single-acting oil cylinder, and the piston rod of double-acting oil cylinder and single-acting oil cylinder extends and exerts force to movable die plate;When detection device detects that the real-time pressure of the rodless cavity of single-acting oil cylinder reaches preset pressure threshold value, control device controls oil supply device to stop oil supply.This scheme establishes pressure monitoring and feedback mechanism for multi-oil cylinder structure, can adjust oil supply state in time according to the real-time change of pressure, realize accurate control to mold locking force.

Description

Technical Field

[0001] This utility model relates to the field of die-casting equipment technology, and in particular to a hydraulic system and die-casting machine with multi-cylinder clamping force control. Background Technology

[0002] The working principle of a die-casting machine is to inject molten or semi-molten metal into a metal mold at high speed, causing the metal to crystallize and form under pressure. In the die-casting production process, controlling the clamping force is crucial for ensuring casting quality and production efficiency. Traditional die-casting machine hydraulic systems typically use a single cylinder to apply the clamping force. However, with the continuous development of die-casting technology and the increasing demands of production, the limitations of single-cylinder hydraulic systems have become increasingly apparent. On the one hand, to generate sufficient clamping force, the diameter of a single cylinder often needs to be large, which not only increases the difficulty of cylinder assembly and disassembly but also necessitates specially made seals, leading to a significant increase in maintenance costs. On the other hand, the hydraulic valves controlling a single cylinder require large diameters, resulting in high procurement costs, slow response speeds, and low control precision, making it difficult to meet the high precision and high efficiency requirements of modern die-casting machines for the clamping process.

[0003] Therefore, researchers in this field have begun to explore the use of multi-cylinder structures for mold clamping operations. However, existing technologies lack mold clamping force control techniques for multi-cylinder structures, failing to fully leverage the advantages of multi-cylinder combinations. For example, the lack of effective pressure monitoring and feedback mechanisms during mold clamping force control makes it impossible to adjust the oil supply status in a timely manner based on real-time pressure changes, easily leading to insufficient or excessive mold clamping force. This not only affects production efficiency but may also cause casting defects and equipment damage. It is evident that existing hydraulic systems have significant shortcomings in meeting the precise mold clamping force control requirements of multi-cylinder structures. Therefore, there is an urgent need for a hydraulic system capable of achieving precise mold clamping force control when multiple cylinders work in tandem. Utility Model Content

[0004] The main purpose of this invention is to propose a hydraulic system for controlling the clamping force of multiple cylinders. The system aims to establish a pressure monitoring and feedback mechanism for the multi-cylinder structure, so as to adjust the oil supply state in a timely manner according to the real-time changes in pressure, thereby achieving precise control of the clamping force and giving full play to the advantages of the multi-cylinder combination to meet the requirements of high precision and high efficiency in the clamping process.

[0005] To achieve the above objectives, the present invention proposes a multi-cylinder clamping force control hydraulic system, comprising:

[0006] A mold-locking cylinder acts on a moving mold plate; the mold-locking cylinder includes a double-acting cylinder and a single-acting cylinder.

[0007] An oil supply device supplies oil to the double-acting cylinder through a first oil supply path, and supplies oil to the single-acting cylinder through a second oil supply path;

[0008] A one-way valve is provided in the oil line between the rodless chamber of the double-acting cylinder and the rodless chamber of the single-acting cylinder to prevent the oil supply device from supplying oil to the rodless chamber of the single-acting cylinder through the first oil supply path.

[0009] When the oil supply device supplies oil to the rodless chamber of the double-acting cylinder through the first oil supply path, the oil supply device supplies oil to the rodless chamber of the single-acting cylinder through the second oil supply path. The piston rods of the double-acting cylinder and the single-acting cylinder extend and jointly apply force to the moving template.

[0010] A detection device is used to detect the real-time pressure of the rodless chamber of the single-acting hydraulic cylinder;

[0011] When the real-time pressure reaches a preset pressure threshold, the control device controls the oil supply device to stop supplying oil.

[0012] In one embodiment, the hydraulic system for controlling the clamping force of the multi-cylinder further includes a reversing valve and an oil tank. The reversing valve is disposed on the first oil supply path. The reversing valve includes an oil inlet, an oil return port, a first working oil port, and a second working oil port. The oil inlet is connected to the oil supply device, the oil return port is connected to the oil tank, the first working oil port is connected to the rod chamber of the double-acting cylinder, and the second working oil port is connected to the rodless chamber of the double-acting cylinder.

[0013] When the reversing valve is in the first reversing position, the oil supply device supplies oil to the rodless chamber of the double-acting cylinder through the second working oil port, and the oil in the rod chamber of the double-acting cylinder is discharged to the oil tank through the first working oil port.

[0014] In one embodiment, when the reversing valve is in the first reversing position, the oil inlet is connected to the second working oil port, and the oil return port is connected to the first working oil port.

[0015] In one embodiment, the piston rod of the double-acting cylinder and the piston rod of the single-acting cylinder are connected to a fixed plate, and the double-acting cylinder and the single-acting cylinder are located between the moving template and the fixed plate;

[0016] When the reversing valve is in the second reversing position, the oil supply device supplies oil to the rod chamber of the double-acting cylinder through the first working oil port, and the oil in the rodless chamber of the double-acting cylinder is discharged to the oil tank through the second working oil port. The oil supply device stops supplying oil to the rodless chamber of the single-acting cylinder through the second oil supply path. The piston rod of the double-acting cylinder retracts and drives the piston rod of the single-acting cylinder to retract through the fixed plate, thereby canceling the force applied to the moving template.

[0017] In one embodiment, when the reversing valve is in the second reversing position, the oil inlet is connected to the first working oil port, and the oil return port is connected to the second working oil port.

[0018] In one embodiment, the control device is electrically connected to the reversing valve;

[0019] When the real-time pressure reaches the preset pressure threshold, the control device controls the reversing valve to switch to the third reversing position to block the oil supply circuit between the oil supply device and the double-acting cylinder.

[0020] In one embodiment, when the reversing valve switches to the third reversing position, the return port is connected to the first working port and the second working port, and the inlet port is cut off.

[0021] In one embodiment, the hydraulic system for controlling the clamping force of the multi-cylinder mold further includes a bidirectional hydraulic lock, which includes a first hydraulically controlled check valve and a second hydraulically controlled check valve.

[0022] The first hydraulic control check valve is installed in the oil line between the first working oil port and the rod chamber of the double-acting cylinder; when the control oil port of the first hydraulic control check valve is not supplied with oil, the first hydraulic control check valve is used to prevent the oil in the rod chamber of the double-acting cylinder from flowing to the first working oil port.

[0023] The second hydraulic control check valve is installed in the oil line between the second working port and the rodless chamber of the double-acting cylinder; when the control port of the second hydraulic control check valve is not supplied with oil, the second hydraulic control check valve is used to prevent the oil in the rodless chamber of the double-acting cylinder from flowing to the second working port.

[0024] In one embodiment, the hydraulic system for controlling the clamping force of the multi-cylinder further includes a first sequence valve, the oil inlet of which is connected to the rodless chamber of the double-acting cylinder, the oil outlet of which is connected to the rodless chamber of the single-acting cylinder, and the control port of which is connected to the rodless chamber of the double-acting cylinder.

[0025] In one embodiment, the hydraulic system for controlling the clamping force of the multi-cylinder further includes a second sequence valve, the oil inlet of which is connected to the rod chamber of the double-acting cylinder, the oil outlet of which is connected to the oil tank, and the control port of which is connected to the rod chamber of the double-acting cylinder.

[0026] In one embodiment, the mold-locking cylinder includes at least two of the double-acting cylinders.

[0027] In one embodiment, the mold-locking cylinder includes at least two of the single-acting cylinders.

[0028] This utility model also proposes a die-casting machine, which includes a hydraulic system with multi-cylinder clamping force control as described above.

[0029] The hydraulic system for controlling the clamping force using multiple cylinders provided by this invention employs a combination of double-acting and single-acting cylinders. Through the coordination of a detection device and a control device, the clamping force is monitored and feedback is provided. This allows for timely adjustment of the oil supply based on real-time changes in the clamping force. When the clamping force reaches a preset requirement, the system automatically enters a pressure-holding state, maintaining the pressure of the double-acting and single-acting cylinders at their current levels, thus ensuring a constant clamping force. Subsequent die-casting operations can then be performed under this clamping force. This solution achieves precise control of the clamping force, fully leveraging the advantages of the multi-cylinder combination to meet the high precision and efficiency requirements of the clamping process. Furthermore, it enables automatic switching from the clamping state to the pressure-holding state, improving response speed and enhancing the automation and intelligence of the multi-cylinder clamping force control hydraulic system. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the oil circuit structure of the multi-cylinder mold-locking hydraulic control system provided in an embodiment of the present invention when it is in the mold-locking state;

[0032] Figure 2 This is a schematic diagram of the oil circuit structure of the multi-cylinder locking hydraulic control system in the pressure holding state according to an embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of the oil circuit structure of the multi-cylinder locking hydraulic control system provided in an embodiment of the present invention when it is in a depressurized state;

[0034] Figure 4 This is a partial structural schematic diagram of a die-casting machine provided in an embodiment of the present invention.

[0035] Explanation of icon numbers:

[0036] 1. Mold clamping cylinder; 101. Double-acting cylinder; 102. Single-acting cylinder;

[0037] 2. Moving template; 3. Fixed plate;

[0038] 4. Oil supply device; 5. Reversing valve; 6. Check valve; 7. Detection device;

[0039] 8. Two-way hydraulic lock; 801. First hydraulically controlled check valve; 802. Second hydraulically controlled check valve;

[0040] 9. First sequence valve; 10. Second sequence valve; 11. Oil tank.

[0041] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

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

[0043] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0044] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0045] The working principle of a die-casting machine is to inject molten or semi-molten metal into a metal mold at high speed, causing the metal to crystallize and form under pressure. In the die-casting production process, controlling the clamping force is crucial for ensuring casting quality and production efficiency. Traditional die-casting machine hydraulic systems typically use a single cylinder to apply the clamping force. However, with the continuous development of die-casting technology and the increasing demands of production, the limitations of single-cylinder hydraulic systems have become increasingly apparent. On the one hand, to generate sufficient clamping force, the diameter of a single cylinder often needs to be large, which not only increases the difficulty of cylinder assembly and disassembly but also necessitates specially made seals, leading to a significant increase in maintenance costs. On the other hand, the hydraulic valves controlling a single cylinder require large diameters, resulting in high procurement costs, slow response speeds, and low control precision, making it difficult to meet the high precision and high efficiency requirements of modern die-casting machines for the clamping process.

[0046] Therefore, researchers in this field have begun to explore the use of multi-cylinder structures for mold clamping operations. However, existing technologies lack mold clamping force control techniques for multi-cylinder structures, failing to fully leverage the advantages of multi-cylinder combinations. For example, the lack of effective pressure monitoring and feedback mechanisms during mold clamping force control makes it impossible to adjust the oil supply status in a timely manner based on real-time pressure changes, easily leading to insufficient or excessive mold clamping force. This not only affects production efficiency but may also cause casting defects and equipment damage. It is evident that existing hydraulic systems have significant shortcomings in meeting the precise mold clamping force control requirements of multi-cylinder structures. Therefore, there is an urgent need for a hydraulic system capable of achieving precise mold clamping force control when multiple cylinders work in tandem.

[0047] To address the aforementioned issues, this invention provides a hydraulic system for controlling clamping force using multiple cylinders. The system aims to establish a pressure monitoring and feedback mechanism for the multi-cylinder structure, allowing for timely adjustment of the oil supply based on real-time pressure changes. This enables precise control of the clamping force, fully leveraging the advantages of the multi-cylinder combination to meet the high precision and efficiency requirements of the clamping process.

[0048] Please see Figure 1 and Figure 2 The hydraulic system for controlling the clamping force of multiple cylinders provided by this utility model includes:

[0049] The mold-locking cylinder 1 acts on the moving mold plate 2; the mold-locking cylinder 1 includes a double-acting cylinder 101 and a single-acting cylinder 102.

[0050] Oil supply device 4 supplies oil to double-acting cylinder 101 through a first oil supply path, and oil supply device 4 supplies oil to single-acting cylinder 102 through a second oil supply path.

[0051] A one-way valve 6 is installed in the oil line between the rodless chamber of the double-acting cylinder 101 and the rodless chamber of the single-acting cylinder 102 to prevent the oil supply device 4 from supplying oil to the rodless chamber of the single-acting cylinder 102 through the first oil supply path.

[0052] When the oil supply device 4 supplies oil to the rodless chamber of the double-acting cylinder 101 through the first oil supply path, the oil supply device 4 supplies oil to the rodless chamber of the single-acting cylinder 102 through the second oil supply path. The piston rods of the double-acting cylinder 101 and the single-acting cylinder 102 extend and jointly apply force to the moving template 2.

[0053] The detection device 7 is used to detect the real-time pressure of the rodless chamber of the single-acting hydraulic cylinder 102;

[0054] The control device (not shown in the figure) controls the oil supply device 4 to stop supplying oil when the real-time pressure reaches the preset pressure threshold.

[0055] The multi-cylinder locking hydraulic control system provided in this embodiment is applied to a die-casting machine. Specifically, the die-casting machine includes a fixed platen and a moving platen 2. The fixed platen is provided with a fixed mold and a guide post. The moving platen 2 is slidably fitted onto the guide post along the length direction of the guide post. A moving mold is provided on the side of the moving platen 2 facing the fixed platen. The moving platen 2 can move along the direction close to the fixed platen under the drive of the mold-moving cylinder so that the moving mold and the fixed mold fit together.

[0056] Hydraulic oil can be supplied to both the rod chamber and the rodless chamber of the double-acting cylinder 101, so that the pressure of the hydraulic oil can drive the piston rod of the double-acting cylinder 101 to extend or retract. The cylinder body of the double-acting cylinder 101 is connected to the side of the moving template 2 facing away from the fixed template, and the piston rod of the double-acting cylinder 101 is connected to the fixed plate 3.

[0057] The single-acting cylinder 102 only has its rodless chamber supplied with hydraulic oil, so that the pressure of the hydraulic oil drives the piston rod of the single-acting cylinder 102 to extend; while the retraction of the piston rod of the single-acting cylinder 102 requires the assistance of spring force, gravity or other external forces. The cylinder body of the single-acting cylinder 102 is connected to the side of the moving template 2 facing away from the fixed template, and the piston rod of the single-acting cylinder 102 is connected to the fixed plate 3.

[0058] Both the double-acting hydraulic cylinder 101 and the single-acting hydraulic cylinder 102 can be configured as one or more; when both the double-acting hydraulic cylinder 101 and the single-acting hydraulic cylinder 102 are configured as multiple, the multiple double-acting hydraulic cylinders 101 and the multiple single-acting hydraulic cylinders 102 can be arranged around the guide post in the circumferential direction, which is not limited here.

[0059] A brake mechanism can be installed on the fixed plate 3. The brake mechanism can engage with the guide post to fix the fixed plate 3 and the guide post. When the piston rods of the double-acting cylinder 101 and the single-acting cylinder 102 extend, since the fixed plate 3 is in a fixed state, they will drive the cylinder bodies of the double-acting cylinder 101 and the single-acting cylinder 102 to move away from the fixed plate 3. This will cause the cylinder bodies of the double-acting cylinder 101 and the single-acting cylinder 102 to apply force to the moving template 2, making the moving mold on the moving template 2 tightly press against the fixed mold on the fixed template. Subsequently, when the piston rods of the double-acting cylinder 101 and the single-acting cylinder 102 retract, since the fixed plate 3 is in a fixed state, they will drive the cylinder bodies of the double-acting cylinder 101 and the single-acting cylinder 102 to move closer to the fixed plate 3. This will cause the force applied to the moving template 2 by the cylinder bodies of the double-acting cylinder 101 and the single-acting cylinder 102 to gradually decrease to zero.

[0060] The oil supply device 4 can refer to a single oil supply unit or a collection of multiple oil supply units. Specifically, when the oil supply device 4 refers to a single oil supply unit, the first oil supply path corresponds to one of the oil supply lines of that unit, and the second oil supply path corresponds to the other oil supply line of that unit. When the oil supply device 4 refers to a collection of multiple oil supply units, the first oil supply path corresponds to one of the oil supply units and its oil supply line, and the second oil supply path corresponds to the other oil supply unit and its oil supply line. Taking an oil pump as an example, in this embodiment, oil can be supplied to the double-acting cylinder 101 through one oil supply line of the pump, and to the single-acting cylinder 102 through the other oil supply line of the same pump. Alternatively, in this embodiment, oil can be supplied to the double-acting cylinder 101 through one oil pump, and to the single-acting cylinder 102 through another oil pump. In practical applications, it is only necessary to ensure that the oil supply operation between the oil supply device 4 and the double-acting oil cylinder 101 and the oil supply operation between the oil supply device 4 and the single-acting oil cylinder 102 are independent of each other. Here, the specific form of the oil supply device 4 and the first oil supply path and the second oil supply path is not limited.

[0061] The rodless chamber of the double-acting cylinder 101 is connected to the rodless chamber of the single-acting cylinder 102 through a one-way valve 6. The one-way valve 6 allows oil to flow from the rodless chamber of the single-acting cylinder 102 to the rodless chamber of the double-acting cylinder 101, and the one-way valve 6 can prevent oil from flowing from the rodless chamber of the double-acting cylinder 101 to the rodless chamber of the single-acting cylinder 102. Based on the above settings, during the mold-locking stage, when the oil supply device 4 supplies oil to the rodless chamber of the double-acting cylinder 101 through the first oil supply path, it can prevent the oil from being diverted to the rodless chamber of the single-acting cylinder 102, which would cause the piston rod of the double-acting cylinder 101 to move too slowly. This ensures the rapid response of the double-acting cylinder 101 and ensures that the single-acting cylinder 102 is in a follow-up state (that is, it ensures that the piston rod of the single-acting cylinder 102 moves with the piston rod of the double-acting cylinder 101 during the initial action phase). It can also maintain the pressure of the rodless chamber of the single-acting cylinder 102 at a low pressure before supplying oil to the rodless chamber of the single-acting cylinder 102, so as to avoid the problem of air suction.

[0062] The detection device 7 can specifically adopt a pressure sensor, and the detection end of the detection device 7 can be set in the oil line connected to the rodless cavity of the single-acting cylinder 102.

[0063] The control device may include a controller, a microcontroller, a microcontroller unit (MCU), and supporting electronic components and connecting devices. It has basic functions such as signal input / output, data storage and retrieval, and logical judgment. The control device can be directly electrically connected to the oil supply device 4 to directly control the oil supply device 4 to start or stop oil supply. The control device can also be connected to the control valves set on the first oil supply path and the second oil supply path to realize the on / off control of the oil supply path by changing the working position of the control valve, thereby indirectly controlling the oil supply device 4 to start or stop oil supply.

[0064] The preset pressure threshold can be stored in the storage module of the control device. The detection device 7 can send the real-time pressure of the rodless chamber of the single-acting cylinder 102 to the control device, and the control device can compare the real-time pressure with the preset pressure threshold.

[0065] Based on the above settings, the specific mold-locking and pressure-holding operations are as follows:

[0066] After entering the mold-locking state, as Figure 1 As shown, the oil supply device 4 supplies oil to the rodless chamber of the double-acting cylinder 101 through the first oil supply path, causing the piston rod of the double-acting cylinder 101 to extend rapidly and, through the fixing plate 3, to cause the piston rod of the single-acting cylinder 102 to extend rapidly. At the same time, the oil supply device 4 supplies oil to the rodless chamber of the single-acting cylinder 102 through the second oil supply path to provide clamping force. In this way, under the action of the fixing plate 3, the cylinder bodies of the double-acting cylinder 101 and the single-acting cylinder 102 can be moved in the opposite direction away from the fixing plate 3, thereby applying the action through the combined action of the cylinder bodies of the double-acting cylinder 101 and the single-acting cylinder 102. Force is applied to the moving mold plate 2, causing the moving mold on the moving mold plate 2 to press tightly against the fixed mold on the fixed mold plate 2; as the oil supply device 4 continuously supplies oil to the rodless chamber of the double-acting cylinder 101 and the rodless chamber of the single-acting cylinder 102, the force exerted on the moving mold plate 2 by the cylinder bodies of the double-acting cylinder 101 and the single-acting cylinder 102 will gradually increase, and the pressure in the rodless chamber of the single-acting cylinder 102 will also gradually increase; when the detection device 7 detects that the real-time pressure in the rodless chamber of the single-acting cylinder 102 reaches the preset pressure threshold, it can be considered that the clamping force at this time has met the clamping force requirements of the die casting operation, such as Figure 2 As shown, the control device will control the oil supply device 4 to stop supplying oil, so that the pressure of the double-acting cylinder 101 and the single-acting cylinder 102 remains at the current state, thereby keeping the clamping force unchanged. In this way, subsequent die casting operations can be carried out under the action of the clamping force.

[0067] Therefore, the hydraulic system for controlling the clamping force using multiple cylinders provided in this embodiment employs a combination of double-acting cylinders 101 and single-acting cylinders 102. Through the cooperation between the detection device 7 and the control device, the clamping force is monitored and feedback is provided. This allows for timely adjustment of the oil supply state based on real-time changes in the clamping force. When the clamping force reaches the preset requirement, the system automatically enters a pressure-holding state, maintaining the pressure of the double-acting cylinders 101 and single-acting cylinders 102 at their current levels, thus keeping the clamping force constant. Subsequent die-casting operations can then be performed under this clamping force. This solution achieves precise control of the clamping force, fully leveraging the advantages of the multi-cylinder combination to meet the high precision and efficiency requirements of the clamping process. Furthermore, it enables automatic switching from the clamping state to the pressure-holding state, improving response speed and enhancing the automation and intelligence of the multi-cylinder clamping force control hydraulic system.

[0068] In one embodiment, refer to Figure 1 The hydraulic system for controlling the clamping force of multiple cylinders also includes a reversing valve 5 and an oil tank 11. The reversing valve 5 is set on the first oil supply path. The reversing valve 5 includes an oil inlet P1, an oil return port T1, a first working oil port A and a second working oil port B. The oil inlet P1 is connected to the oil supply device 4, the oil return port T1 is connected to the oil tank 11, the first working oil port A is connected to the rod chamber of the double-acting cylinder 101, and the second working oil port B is connected to the rodless chamber of the double-acting cylinder 101.

[0069] When the reversing valve 5 is in the first reversing position, the oil supply device 4 supplies oil to the rodless chamber of the double-acting cylinder 101 through the second working oil port B, and the oil in the rod chamber of the double-acting cylinder 101 is discharged to the oil tank 11 through the first working oil port A.

[0070] Specifically, the directional valve 5 can be a solenoid valve, whose valve core slides in the valve body. When the electromagnet is energized, it can attract the valve core. Thus, the position of the valve core in the valve body can be changed by the energization or de-energization of the electromagnet. In turn, the directional valve 5 can switch between different directional positions by changing the position of the valve core, so as to realize the selection between the oil inlet P1, the oil return T1 and the first working oil port A and the second working oil port B, so as to control the on-off and flow direction of hydraulic oil.

[0071] Based on the above settings, the specific mold-locking and pressure-holding operations are as follows:

[0072] After entering the mold-locking state, as Figure 1As shown, when the reversing valve 5 switches to the first reversing position, the oil supply device 4 sequentially supplies oil to the rodless chamber of the double-acting cylinder 101 through the oil inlet P1 and the second working oil port B of the reversing valve 5. This causes the piston rod of the double-acting cylinder 101 to extend rapidly and, through the fixing plate 3, causes the piston rod of the single-acting cylinder 102 to extend rapidly. At this time, the piston rod of the double-acting cylinder 101 will compress the rod chamber of the double-acting cylinder 101, causing the oil in the rod chamber of the double-acting cylinder 101 to be squeezed and discharged sequentially through the first working oil port A and the return oil port T1 of the reversing valve 5 to the oil outlet. In box 11, the piston rod of double-acting cylinder 101 can be extended smoothly; at the same time, the oil supply device 4 will supply oil to the rodless cavity of single-acting cylinder 102 through the second oil supply path to provide clamping force. In this way, under the action of fixed plate 3, the cylinder bodies of double-acting cylinder 101 and single-acting cylinder 102 can be driven to move away from fixed plate 3 in the opposite direction. Thus, the cylinder bodies of double-acting cylinder 101 and single-acting cylinder 102 jointly apply force to moving platen 2, so that the moving mold on moving platen 2 is tightly pressed with the fixed mold on fixed platen 2.

[0073] In this embodiment, by setting a reversing valve 5 and an oil tank 11, on the one hand, the reversing valve 5 can be used to precisely control the flow direction, flow rate and flow velocity of the oil supplied by the oil supply device 4, so as to meet the high precision requirements in the mold clamping process; on the other hand, it can ensure that the oil in the compressed cavity of the double-acting cylinder 101 can be discharged to the oil tank 11 through the reversing valve 5, thereby ensuring that the piston rod of the double-acting cylinder 101 can move normally.

[0074] In one embodiment, refer to Figure 2 The control device is electrically connected to the reversing valve 5;

[0075] When the real-time pressure reaches the preset pressure threshold, the control device controls the reversing valve 5 to switch to the third reversing position to block the oil supply circuit between the oil supply device 4 and the double-acting oil cylinder 101.

[0076] Specifically, when the control device determines that the real-time pressure in the rodless chamber of the single-acting cylinder 102 reaches a preset pressure threshold, such as... Figure 2As shown, the control device sends an electrical signal to trigger the corresponding electromagnet in the directional valve 5 to be energized or de-energized, thereby changing the position of the valve core in the valve body and switching the directional valve 5 to the third reversing position. Through the switching action of the directional valve 5, the system can complete the oil circuit switching in a very short time, thus quickly cutting off the oil supply circuit between the oil supply device 4 and the double-acting cylinder 101, greatly improving the response speed. Compared with directly controlling the oil supply device 4 to stop the oil supply, the switching action of the directional valve 5 is faster and more flexible, reducing time delay, stabilizing the system pressure more quickly, avoiding pressure fluctuations caused by the inertial flow of oil, achieving precise control of the clamping force, and reducing the frequency of starting and stopping the oil supply device 4, thereby reducing maintenance costs caused by equipment wear.

[0077] In one embodiment, refer to Figure 3 The piston rods of the double-acting cylinder 101 and the single-acting cylinder 102 are connected to the fixed plate 3. The double-acting cylinder 101 and the single-acting cylinder 102 are located between the moving template 2 and the fixed plate 3.

[0078] When the reversing valve 5 is in the second reversing position, the oil supply device 4 supplies oil to the rod chamber of the double-acting cylinder 101 through the first working oil port A, and the oil in the rodless chamber of the double-acting cylinder 101 is discharged to the oil tank 11 through the second working oil port B. The oil supply device 4 stops supplying oil to the rodless chamber of the single-acting cylinder 102 through the second oil supply path. The piston rod of the double-acting cylinder 101 retracts and drives the piston rod of the single-acting cylinder 102 to retract through the fixing plate 3, thereby canceling the force applied to the moving template 2.

[0079] Specifically, after the die-casting operation is completed, it is necessary to release the clamping force between the moving mold and the fixed mold, such as... Figure 3 As shown, at this time, the reversing valve 5 is switched to the second reversing position, and the oil supply device 4 supplies oil to the rod chamber of the double-acting cylinder 101 through the oil inlet P1 and the first working oil port A in sequence. This causes the piston rod of the double-acting cylinder 101 to retract quickly and drive the piston rod of the single-acting cylinder 102 to retract quickly through the fixing plate 3. At the same time, the oil supply device 4 stops supplying oil to the rodless chamber of the single-acting cylinder 102 through the second oil supply path. In this way, under the action of the fixing plate 3, the cylinder bodies of the double-acting cylinder 101 and the single-acting cylinder 102 can be driven to move in the opposite direction towards the fixing plate 3. This causes the force applied to the moving template 2 by the cylinder bodies of the double-acting cylinder 101 and the single-acting cylinder 102 to gradually decrease until the force applied to the moving template 2 is finally canceled, so that the pressing force between the moving mold on the moving template 2 and the fixed mold on the fixed template becomes zero, thus completing the pressure relief operation.

[0080] In one embodiment, refer to Figures 1 to 3When the reversing valve 5 is in the first reversing position, the oil inlet P1 is connected to the second working oil port B, and the oil return port T1 is connected to the first working oil port A.

[0081] In one embodiment, refer to Figures 1 to 3 When the reversing valve 5 is in the second reversing position, the oil inlet P1 is connected to the first working oil port A, and the oil return port T1 is connected to the second working oil port B.

[0082] In one embodiment, refer to Figures 1 to 3 When the reversing valve 5 is switched to the third reversing position, the return oil port T1 is connected to the first working oil port A and the second working oil port B, and the oil inlet port P1 is cut off.

[0083] Taking the reversing valve 5 as an example of an electromagnetic reversing valve, in the initial state, both electromagnetic coils a and b are de-energized, and the valve core of the reversing valve 5 is in the middle third reversing position. At this time, the first working oil port A and the second working oil port B are both connected to the return oil port T1, and the oil inlet port P1 is closed; when the mold locking operation begins, as Figure 1 As shown, when the solenoid coil a of the reversing valve 5 is energized, it drives the valve core of the reversing valve 5 to switch to the first reversing position. At this time, the oil inlet P1 is connected to the second working oil port B, and the oil return port T1 is connected to the first working oil port A. The oil supplied by the oil supply device 4 can be supplied into the rodless chamber of the double-acting cylinder 101 through the oil inlet P1 and the second working oil port B in sequence. The pressure of the oil will push the piston rod of the double-acting cylinder 101 to extend and compress the rod chamber of the double-acting cylinder 101, so that the oil in the rod chamber of the double-acting cylinder 101 is squeezed and passes through in sequence. The first working oil port A and the return oil port T1 drain to the oil tank 11. The piston rod of the double-acting cylinder 101 also drives the piston rod of the single-acting cylinder 102 to extend through the fixing plate 3. At the same time, the oil supply device 4 also supplies oil to the rodless cavity of the single-acting cylinder 102 through the second oil supply path to provide clamping force. In this way, the cylinder bodies of the double-acting cylinder 101 and the single-acting cylinder 102 can jointly apply force to the moving platen 2. When the detection device 7 detects that the real-time pressure of the rodless cavity of the single-acting cylinder 102 reaches the preset pressure threshold, such as Figure 2 As shown, the control device outputs a corresponding electrical signal to trigger the de-energization of the solenoid coil a of the reversing valve 5, causing the valve core of the reversing valve 5 to reset to the middle third reversing position. At this time, the first working oil port A and the second working oil port B are both connected to the return oil port T1, and the oil inlet P1 is cut off. The oil supply device 4 cannot supply oil to the rodless chamber of the double-acting cylinder 101 through the reversing valve 5. At the same time, the control device controls the oil supply device 4 to stop supplying oil to the rodless chamber of the single-acting cylinder 102 through the second oil supply path. In this way, the clamping force can be maintained at the current state, that is, entering the pressure holding state, so as to perform the die casting operation under the preset clamping force. After the die casting operation is completed, as Figure 3As shown, when the solenoid coil b of the reversing valve 5 is energized, it drives the valve core of the reversing valve 5 to switch to the second reversing position. At this time, the oil inlet P1 is connected to the first working oil port A, and the oil return port T1 is connected to the second working oil port B. The oil supplied by the oil supply device 4 can be supplied to the rod chamber of the double-acting cylinder 101 through the oil inlet P1 and the first working oil port A in sequence. The pressure of the oil will push the piston rod of the double-acting cylinder 101 to retract and compress the rodless chamber of the double-acting cylinder 101, so that the oil in the rodless chamber of the double-acting cylinder 101 is squeezed and passes through the second working oil port B in sequence. Working oil port B and return oil port T1 drain to oil tank 11. The piston rod of double-acting cylinder 101 also drives the piston rod of single-acting cylinder 102 to retract through fixed plate 3, so that the oil in the rodless chamber of single-acting cylinder 102 is squeezed and drained to oil tank 11 through check valve 6, second working oil port B and return oil port T1 in sequence. As a result, the force applied to the moving plate 2 by the cylinder body of double-acting cylinder 101 and cylinder body of single-acting cylinder 102 gradually decreases until the force applied to the moving plate 2 is finally canceled and the pressure relief operation is completed.

[0084] In one embodiment, refer to Figures 1 to 3 The hydraulic system for controlling the clamping force of the multi-cylinder mold also includes a two-way hydraulic lock 8, which includes a first hydraulic control check valve 801 and a second hydraulic control check valve 802.

[0085] The first hydraulic control check valve 801 is installed in the oil line between the first working oil port A and the rod chamber of the double-acting cylinder 101; when the control oil port of the first hydraulic control check valve 801 is not supplied with oil, the first hydraulic control check valve 801 is used to prevent the oil in the rod chamber of the double-acting cylinder 101 from flowing to the first working oil port A.

[0086] The second hydraulic check valve 802 is installed in the oil line between the second working port B and the rodless chamber of the double-acting cylinder 101. When the control port of the second hydraulic check valve 802 is not supplied with oil, the second hydraulic check valve 802 is used to prevent the oil in the rodless chamber of the double-acting cylinder 101 from flowing to the second working port B.

[0087] In this embodiment, the control port of the first hydraulic check valve 801 is connected to the inlet of the second hydraulic check valve 802, and the control port of the second hydraulic check valve 802 is connected to the inlet of the first hydraulic check valve 801. When the oil supply device 4 does not supply oil to the oil circuit where the first hydraulic check valve 801 is located through the reversing valve 5, no oil enters the control port of the second hydraulic check valve 802. At this time, the second hydraulic check valve 802 is in a one-way open state, which can prevent the oil in the rodless chamber of the double-acting cylinder 101 and the rodless chamber of the single-acting cylinder 102 from flowing towards the reversing valve 5. Similarly, when the oil supply device 4 does not supply oil to the oil circuit where the second hydraulic check valve 802 is located through the reversing valve 5, no oil enters the control port of the first hydraulic check valve 801. At this time, the first hydraulic check valve 801 is in a one-way open state, which can prevent the oil in the rod chamber of the double-acting cylinder 101 from flowing towards the reversing valve 5. Based on the above settings, oil leakage in the double-acting cylinder 101 and the single-acting cylinder 102 can be avoided when the cylinder is not in operation.

[0088] During the mold-locking stage, the oil supply device 4 supplies oil to the rodless chamber of the double-acting cylinder 101 through the second hydraulic check valve 802. The oil flowing through the second hydraulic check valve 802 will simultaneously flow into the control port of the first hydraulic check valve 801, causing the first hydraulic check valve 801 to enter a bidirectional conduction state. At this time, the oil in the rod chamber of the double-acting cylinder 101 can be discharged to the oil tank 11 in sequence through the first hydraulic check valve 801 and the reversing valve 5, so as to avoid the extension action of the piston rod of the double-acting cylinder 101 being blocked. During the depressurization phase, the oil supply device 4 supplies oil to the rod chamber of the double-acting cylinder 101 through the first hydraulic check valve 801. The oil flowing through the first hydraulic check valve 801 will simultaneously flow into the control port of the second hydraulic check valve 802, causing the second hydraulic check valve 802 to enter a bidirectional conduction state. At this time, the oil in the rodless chamber of the double-acting cylinder 101 and the rodless chamber of the single-acting cylinder 102 can be discharged into the oil tank 11 in sequence through the second hydraulic check valve 802 and the reversing valve 5, so as to avoid obstruction of the retraction action of the piston rod of the double-acting cylinder 101 and the piston rod of the single-acting cylinder 102.

[0089] This embodiment, by setting a bidirectional hydraulic lock 8, avoids oil leakage during non-working phases while ensuring normal oil drainage in the corresponding cavities of the double-acting cylinder 101 and the single-acting cylinder 102 during the mold-locking and pressure-relief phases, thereby further improving the control accuracy and operational reliability of the system.

[0090] In one embodiment, refer to Figures 1 to 3 The hydraulic system for controlling the clamping force of multiple cylinders also includes a first sequence valve 9. The oil inlet of the first sequence valve 9 is connected to the rodless chamber of the double-acting cylinder 101, the oil outlet of the first sequence valve 9 is connected to the rodless chamber of the single-acting cylinder 102, and the control port of the first sequence valve 9 is connected to the rodless chamber of the double-acting cylinder 101.

[0091] During the pressure relief phase, the oil in the rodless chamber of the double-acting cylinder 101 needs to be discharged to the oil tank 11 through the bidirectional hydraulic lock 8 and the reversing valve 5 in sequence. However, in actual application, the bidirectional hydraulic lock 8 and the corresponding components on the oil circuit may experience jamming, causing the oil circuit to be blocked. This prevents the oil in the rodless chamber of the double-acting cylinder 101 from being discharged smoothly to the oil tank 11, resulting in the double-acting cylinder 101 being damaged due to abnormally high pressure.

[0092] To address the aforementioned issues, this embodiment adds a first sequence valve 9 to the oil circuit between the rodless chamber of the double-acting cylinder 101 and the rodless chamber of the single-acting cylinder 102. The first sequence valve 9 is in a closed state during normal system operation. When the oil in the rodless chamber of the double-acting cylinder 101 cannot drain normally, causing the pressure in the rodless chamber to rise to the preset pressure value of the first sequence valve 9, the oil reaching a certain pressure will push the valve core to move through the control port of the first sequence valve 9, causing the first sequence valve 9 to switch to a one-way conduction state. At this time, the oil in the rodless chamber of the double-acting cylinder 101 can drain to the single-acting cylinder 102 through the first sequence valve 9. This allows for pressure relief of the rodless chamber of the double-acting cylinder 101 when the oil circuit is blocked, preventing damage to the double-acting cylinder 101 due to abnormally high pressure, thereby improving the reliability and safety of the system.

[0093] In one embodiment, refer to Figures 1 to 3 The hydraulic system for controlling the clamping force of multiple cylinders also includes a second sequence valve 10. The oil inlet of the second sequence valve 10 is connected to the rod chamber of the double-acting cylinder 101, the oil outlet of the second sequence valve 10 is connected to the oil tank 11, and the control port of the second sequence valve 10 is connected to the rod chamber of the double-acting cylinder 101.

[0094] During the mold-locking stage, the oil in the rod chamber of the double-acting cylinder 101 needs to be discharged to the oil tank 11 through the bidirectional hydraulic lock 8 and the reversing valve 5 in sequence. However, in actual application, the bidirectional hydraulic lock 8 and the corresponding components on the oil circuit may experience jamming, causing the oil circuit to be blocked. This prevents the oil in the rod chamber of the double-acting cylinder 101 from being discharged smoothly to the oil tank 11, resulting in the double-acting cylinder 101 being damaged due to abnormal high pressure.

[0095] To address the aforementioned issues, this embodiment adds a second sequence valve 10 to the oil line between the rod chamber of the double-acting cylinder 101 and the oil tank 11. The second sequence valve 10 is in a closed state during normal system operation. When the oil in the rod chamber of the double-acting cylinder 101 cannot drain normally, causing the pressure in the rod chamber to rise to the preset pressure value of the second sequence valve 10, the oil reaching a certain pressure will push the valve core to move through the control port of the second sequence valve 10, causing the second sequence valve 10 to switch to a one-way conduction state. At this time, the oil in the rod chamber of the double-acting cylinder 101 can drain to the oil tank 11 through the second sequence valve 10. This allows for pressure relief of the rod chamber of the double-acting cylinder 101 when the oil line is blocked, preventing damage to the double-acting cylinder 101 due to abnormally high pressure, thereby improving the reliability and safety of the system.

[0096] In one embodiment, refer to Figures 1 to 4 The mold-locking cylinder 1 includes at least two double-acting cylinders 101.

[0097] In one embodiment, refer to Figures 1 to 4 The mold-locking cylinder 1 includes at least two single-acting cylinders 102.

[0098] In practical applications, as an example, two double-acting cylinders 101 and four single-acting cylinders 102 can be configured. The two double-acting cylinders 101 and four single-acting cylinders 102 can be interspersed and arranged circumferentially around the guide post. This allows for a more uniform distribution of the clamping force, thereby further improving the clamping performance of the die-casting machine. Furthermore, the number and arrangement of the double-acting cylinders 101 and single-acting cylinders 102 can be set to other quantities and arrangements as needed, which are not limited here.

[0099] This utility model embodiment also provides a die-casting machine, please refer to [link / reference]. Figures 1 to 4 The die-casting machine includes a hydraulic system with multi-cylinder clamping force control in any of the above embodiments.

[0100] In this embodiment, the die-casting machine can specifically be a two-plate die-casting machine. For the specific structure of the multi-cylinder clamping hydraulic control system, please refer to the description of the above embodiments. Since the die-casting machine in this embodiment adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments. That is, it adopts a combination of double-acting cylinder 101 and single-acting cylinder 102, and monitors and provides feedback on the clamping force through the cooperation between the detection device 7 and the control device. This allows for timely adjustment of the oil supply state according to the real-time changes in the clamping force. When the clamping force reaches the preset requirement, the system automatically triggers to enter the pressure-holding state, maintaining the pressure of the double-acting cylinder 101 and the single-acting cylinder 102 at the current state, thereby keeping the clamping force unchanged. Subsequent die-casting operations can then be performed under the action of this clamping force. This solution achieves precise control of the clamping force, fully leveraging the advantages of the multi-cylinder combination to meet the high precision and high efficiency requirements of the clamping process. Furthermore, it achieves automatic switching from the clamping state to the pressure-holding state, improving the response speed and enhancing the automation and intelligence of the multi-cylinder clamping force control hydraulic system.

[0101] It should be noted that other aspects of the hydraulic system for controlling the multi-cylinder clamping force disclosed in this utility model and the die-casting machine can be found in the prior art, and will not be repeated here.

[0102] The above description is merely an exemplary embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A hydraulic system for controlling the clamping force of multiple cylinders, characterized in that, include: A mold-locking cylinder acts on a moving mold plate; the mold-locking cylinder includes a double-acting cylinder and a single-acting cylinder. An oil supply device supplies oil to the double-acting cylinder through a first oil supply path, and supplies oil to the single-acting cylinder through a second oil supply path; A one-way valve is provided in the oil line between the rodless chamber of the double-acting cylinder and the rodless chamber of the single-acting cylinder to prevent the oil supply device from supplying oil to the rodless chamber of the single-acting cylinder through the first oil supply path. When the oil supply device supplies oil to the rodless chamber of the double-acting cylinder through the first oil supply path, the oil supply device supplies oil to the rodless chamber of the single-acting cylinder through the second oil supply path. The piston rods of the double-acting cylinder and the single-acting cylinder extend and jointly apply force to the moving template. A detection device is used to detect the real-time pressure of the rodless chamber of the single-acting hydraulic cylinder; When the real-time pressure reaches a preset pressure threshold, the control device controls the oil supply device to stop supplying oil.

2. The hydraulic system for controlling the clamping force of multiple cylinders as described in claim 1, characterized in that, The hydraulic system for controlling the clamping force of the multi-cylinder includes a reversing valve and an oil tank. The reversing valve is located on the first oil supply path. The reversing valve includes an oil inlet, an oil return port, a first working oil port, and a second working oil port. The oil inlet is connected to the oil supply device, the oil return port is connected to the oil tank, the first working oil port is connected to the rod chamber of the double-acting cylinder, and the second working oil port is connected to the rodless chamber of the double-acting cylinder. When the reversing valve is in the first reversing position, the oil supply device supplies oil to the rodless chamber of the double-acting cylinder through the second working oil port, and the oil in the rod chamber of the double-acting cylinder is discharged to the oil tank through the first working oil port.

3. The hydraulic system for controlling the clamping force of multiple cylinders as described in claim 2, characterized in that, When the reversing valve is in the first reversing position, the oil inlet is connected to the second working oil port, and the oil return port is connected to the first working oil port.

4. The hydraulic system for controlling the clamping force of multiple cylinders as described in claim 2, characterized in that, The piston rods of the double-acting cylinder and the single-acting cylinder are connected to the fixed plate, and the double-acting cylinder and the single-acting cylinder are located between the moving template and the fixed plate. When the reversing valve is in the second reversing position, the oil supply device supplies oil to the rod chamber of the double-acting cylinder through the first working oil port, and the oil in the rodless chamber of the double-acting cylinder is discharged to the oil tank through the second working oil port. The oil supply device stops supplying oil to the rodless chamber of the single-acting cylinder through the second oil supply path. The piston rod of the double-acting cylinder retracts and drives the piston rod of the single-acting cylinder to retract through the fixed plate, thereby canceling the force applied to the moving template.

5. The hydraulic system for controlling the clamping force of multiple cylinders as described in claim 4, characterized in that, When the reversing valve is in the second reversing position, the oil inlet is connected to the first working oil port, and the oil return port is connected to the second working oil port.

6. The hydraulic system for controlling the clamping force of multiple cylinders as described in claim 2, characterized in that, The control device is electrically connected to the reversing valve; When the real-time pressure reaches the preset pressure threshold, the control device controls the reversing valve to switch to the third reversing position to block the oil supply circuit between the oil supply device and the double-acting cylinder.

7. The hydraulic system for controlling the clamping force of multiple cylinders as described in claim 6, characterized in that, When the reversing valve switches to the third reversing position, the return oil port is connected to the first working oil port and the second working oil port, and the inlet oil port is cut off.

8. The hydraulic system for controlling the clamping force of multiple cylinders as described in claim 2, characterized in that, The hydraulic system for controlling the clamping force of the multi-cylinder mold also includes a two-way hydraulic lock, which includes a first hydraulically controlled check valve and a second hydraulically controlled check valve. The first hydraulic control check valve is installed in the oil line between the first working oil port and the rod chamber of the double-acting cylinder; when the control oil port of the first hydraulic control check valve is not supplied with oil, the first hydraulic control check valve is used to prevent the oil in the rod chamber of the double-acting cylinder from flowing to the first working oil port. The second hydraulic control check valve is installed in the oil line between the second working port and the rodless chamber of the double-acting cylinder; when the control port of the second hydraulic control check valve is not supplied with oil, the second hydraulic control check valve is used to prevent the oil in the rodless chamber of the double-acting cylinder from flowing to the second working port.

9. The hydraulic system for controlling the clamping force of multiple cylinders as described in any one of claims 1 to 8, characterized in that, The hydraulic system for controlling the clamping force of the multi-cylinder also includes a first sequence valve. The oil inlet of the first sequence valve is connected to the rodless chamber of the double-acting cylinder, the oil outlet of the first sequence valve is connected to the rodless chamber of the single-acting cylinder, and the control port of the first sequence valve is connected to the rodless chamber of the double-acting cylinder. And / or, the hydraulic system for controlling the clamping force of the multi-cylinder further includes a second sequence valve, the oil inlet of the second sequence valve is connected to the rod chamber of the double-acting cylinder, the oil outlet of the second sequence valve is connected to the oil tank, and the control port of the second sequence valve is connected to the rod chamber of the double-acting cylinder; And / or, the mold-locking cylinder includes at least two of the double-acting cylinders; And / or, the mold-locking cylinder includes at least two of the single-acting cylinders.

10. A die-casting machine, characterized in that, The die-casting machine includes a hydraulic system with multi-cylinder clamping force control as described in any one of claims 1 to 9.

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