Multi-oil cylinder oil-supplying and discharging hydraulic circuit and die-casting machine

Abstract

This utility model discloses a multi-cylinder gear-mounted oil replenishment and drainage hydraulic circuit and a die-casting machine, relating to the field of die-casting equipment technology. It includes a mold-locking cylinder, an oil supply device, a cartridge valve, and a control device. The mold-locking cylinder includes a double-acting cylinder and a single-acting cylinder. The cartridge valve includes a control port and a replenishment / drainage oil path. The control port is connected to a first oil tank, and the two ends of the replenishment / drainage oil path are respectively connected to a low-pressure pump and the rodless chamber of the single-acting cylinder. When the oil supply device supplies oil to the double-acting cylinder, the single-acting cylinder passively extends or retracts. The control device controls the oil from the control port to enter the first oil tank, thus making the replenishment / drainage oil path bidirectionally open. This causes the pressure in the rodless chamber of the single-acting cylinder to become consistent with the pressure of the low-pressure pump, allowing the oil from the low-pressure pump to replenish the single-acting cylinder, or allowing the oil from the single-acting cylinder to drain to the low-pressure pump. This solution solves the problem that existing single-acting cylinders, during passive extension and retraction, experience significant resistance due to back pressure and are prone to cavitation.

Description

Technical Field

[0001] This utility model relates to the field of die-casting equipment technology, and in particular to a multi-cylinder gear-mounted oil replenishment and drainage hydraulic circuit and a die-casting machine. 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 solidify under pressure. In existing hydraulic clamping technology for die-casting machines, a single hydraulic cylinder is typically used for clamping. This single-cylinder structure has several limitations: firstly, to generate sufficient clamping force, the diameter of the single cylinder often needs to be large, which not only increases the difficulty of assembling and disassembling the cylinder but also necessitates specially made sealing rings, leading to a significant increase in maintenance costs; secondly, the hydraulic valve controlling the single cylinder requires a large diameter, resulting in high procurement costs, slow response speed, 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-locking operations. In the gear-aligning stage before mold-locking, the faster-responding double-acting cylinder in the multi-cylinder structure drives the slower-responding single-acting cylinder to extend and retract, thereby aligning the brake device with the teeth on the guide post. However, due to back pressure, the retraction of the piston rod of the single-acting cylinder generates significant resistance, leading to increased energy consumption and reduced gear-aligning efficiency. Furthermore, the piston rod of the single-acting cylinder is prone to cavitation when passively extended, which can damage the hydraulic system. Utility Model Content

[0004] The main purpose of this invention is to propose a multi-cylinder gear-type oil replenishment and discharge hydraulic circuit, which aims to solve the problem that existing single-acting cylinders have large resistance due to back pressure and are prone to air suction during passive extension and retraction.

[0005] To achieve the above objectives, this utility model proposes a multi-cylinder gear-mounted oil supply and drainage hydraulic circuit, including a mold-locking cylinder, an oil supply device, a cartridge valve, and a control device; wherein:

[0006] The mold-locking cylinder includes a double-acting cylinder and a single-acting cylinder. The piston rods of the double-acting cylinder and the single-acting cylinder are connected to the brake mechanism. The oil supply device is used to supply oil to the double-acting cylinder. The cartridge valve includes a control port and a replenishment / relief oil passage. The control port is connected to the first oil tank. The two ends of the replenishment / relief oil passage are respectively connected to the low-pressure pump and the rodless chamber of the single-acting cylinder.

[0007] When the oil supply device supplies oil to the rodless chamber of the double-acting cylinder, the piston rod of the double-acting cylinder extends and drives the piston rod of the single-acting cylinder to extend through the brake mechanism. The control device controls the oil in the control port to enter the first oil tank, thereby opening the two-way flow of the replenishment and discharge oil circuit. This makes the pressure in the rodless chamber of the single-acting cylinder more consistent with the working pressure of the low-pressure pump, so that the oil in the low-pressure pump is replenished into the rodless chamber of the single-acting cylinder through the replenishment and discharge oil circuit.

[0008] When the oil supply device supplies oil to the rod chamber of the double-acting cylinder, the piston rod of the double-acting cylinder retracts and drives the piston rod of the single-acting cylinder to retract through the brake mechanism. The control device controls the oil in the control port to enter the first oil tank, thereby opening the two-way flow path of the replenishment and discharge oil circuit. This causes the pressure in the rodless chamber of the single-acting cylinder to become consistent with the working pressure of the low-pressure pump, so that the oil in the rodless chamber of the single-acting cylinder is discharged to the low-pressure pump through the replenishment and discharge oil circuit.

[0009] In one embodiment, the cartridge valve includes a first working port and a second working port, and the oil passage between the first working port and the second working port constitutes the refill / release oil passage; the first working port is connected to the low-pressure pump, and the second working port is connected to the rodless chamber of the single-acting cylinder.

[0010] In one embodiment, the multi-cylinder gear-matching oil replenishment and discharge hydraulic circuit further includes a first directional valve, which is disposed on the oil line between the control port and the first oil tank.

[0011] When the first reversing valve is in the first reversing position, the first reversing valve is used to prevent the oil from the control port from entering the first oil tank.

[0012] When the oil supply device supplies oil to the double-acting cylinder, the control device controls the first reversing valve to be energized and switch to the second reversing position, so that the oil in the control port enters the first oil tank through the first reversing valve.

[0013] In one embodiment, the first reversing valve includes a third working port and a fourth working port, the third working port being connected to the first oil tank and the fourth working port being connected to the control port;

[0014] When the first reversing valve is in the first reversing position, the oil passage between the third working port and the fourth working port is unidirectionally connected; when the first reversing valve is in the second reversing position, the oil passage between the third working port and the fourth working port is bidirectionally connected.

[0015] In one embodiment, the multi-cylinder gear-mounted oil replenishment and discharge hydraulic circuit further includes a second directional valve and a second oil tank; the second directional valve includes an oil inlet, an oil return port, a fifth working oil port and a sixth working oil port, the oil inlet is connected to the oil supply device, the oil return port is connected to the second oil tank, the fifth working oil port is connected to the rod chamber of the double-acting cylinder, and the sixth working oil port is connected to the rodless chamber of the double-acting cylinder;

[0016] When the second reversing valve is in the first reversing state, the oil supply device supplies oil to the rodless chamber of the double-acting cylinder through the sixth working oil port, so that the piston rod of the double-acting cylinder extends.

[0017] When the second reversing valve is in the second reversing state, the oil supply device supplies oil to the rod chamber of the double-acting cylinder through the fifth working oil port, so that the piston rod of the double-acting cylinder retracts.

[0018] In one embodiment, when the second reversing valve is in the first reversing state, the oil inlet is connected to the sixth working oil port, the oil return port is connected to the fifth working oil port, and the oil in the rod chamber of the double-acting cylinder is discharged to the second oil tank through the fifth working oil port.

[0019] In one embodiment, when the second reversing valve is in the second reversing state, the oil inlet is connected to the fifth working oil port, the oil return port is connected to the sixth working oil port, and the oil in the rodless chamber of the double-acting cylinder is discharged to the second oil tank through the sixth working oil port.

[0020] In one embodiment, the multi-cylinder gear oil replenishment and discharge hydraulic circuit further includes a two-way hydraulic lock, which includes a first hydraulically controlled check valve and a second hydraulically controlled check valve.

[0021] The first hydraulic control check valve is disposed in the oil line between the fifth working oil port and the rod chamber of the double-acting cylinder; when the control 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 fifth working oil port.

[0022] The second hydraulic control check valve is disposed in the oil line between the sixth 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 sixth working port.

[0023] In one embodiment, the multi-cylinder gear-type oil replenishment and discharge hydraulic circuit further includes a one-way valve; the one-way valve is disposed 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.

[0024] In one embodiment, the multi-cylinder gear-pairing oil replenishment and discharge hydraulic circuit further includes a first sequence valve, the oil inlet of the first sequence valve being connected to the rod chamber of the double-acting cylinder, the oil outlet of the first sequence valve being connected to the second oil tank, and the control end of the first sequence valve being connected to the rod chamber of the double-acting cylinder.

[0025] In one embodiment, the multi-cylinder gear-pairing oil replenishment and discharge hydraulic circuit further includes a second sequence valve. The oil inlet of the second sequence valve is connected to the rodless chamber of the double-acting cylinder, the oil outlet of the second sequence valve is connected to the rodless chamber of the single-acting cylinder, and the control end of the second sequence valve is connected to the rodless chamber of the double-acting cylinder.

[0026] This utility model also proposes a die-casting machine, which includes the aforementioned multi-cylinder gear-aligned oil replenishment and drainage hydraulic circuit.

[0027] The multi-cylinder gear-aligning oil replenishment and drainage hydraulic circuit provided by this utility model connects the rodless chamber of the single-acting cylinder to the low-pressure pump via the replenishment and drainage oil passage of a cartridge valve. When the piston rod of the single-acting cylinder is passively retracted during gear alignment, the replenishment and drainage oil passage in the cartridge valve switches to a bidirectional conduction state, making the pressure in the rodless chamber of the single-acting cylinder tend to match the working pressure of the low-pressure pump. Because the working pressure of the low-pressure pump is relatively low, the back pressure it generates on the piston rod of the single-acting cylinder is relatively small. The oil in the rodless chamber of the single-acting cylinder can smoothly flow back to the low-pressure pump along the replenishment and drainage oil passage with less resistance, avoiding damage to the single-acting cylinder due to excessive resistance. The retraction of the piston rod creates resistance, ensuring a rapid response of the single-acting cylinder during retraction and reducing energy consumption to overcome back pressure, thus achieving good energy-saving effects in the hydraulic system. When the piston rod of the single-acting cylinder is passively extended during gear alignment, the refill / relief oil circuit in the cartridge valve also switches to a bidirectional state, making the pressure in the rodless chamber of the single-acting cylinder more consistent with the working pressure of the low-pressure pump. This allows the oil from the low-pressure pump to smoothly replenish the rodless chamber of the single-acting cylinder through the refill / relief oil circuit, preventing cavitation in the single-acting cylinder and thus avoiding damage to the hydraulic system caused by cavitation. Attached Figure Description

[0028] 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.

[0029] Figure 1 A schematic diagram of the structure of the multi-cylinder gear-aligning oil replenishment and oil draining hydraulic circuit provided by this utility model when it is not in the gear-aligning state;

[0030] Figure 2 This is a schematic diagram of the structure of the multi-cylinder gear-aligning oil replenishment and drainage hydraulic circuit provided by this utility model when it enters the gear-aligning state.

[0031] Explanation of icon numbers:

[0032] 1. Mold clamping cylinder; 101. Double-acting cylinder; 102. Single-acting cylinder;

[0033] 2. Fixed plate; 3. Moving template; 4. Oil supply device; 5. Cartridge valve; 6. First oil tank; 7. Low-pressure pump; 8. First directional valve; 9. Second directional valve; 10. Second oil tank;

[0034] 11. Two-way hydraulic lock; 1101. First hydraulically controlled check valve; 1102. Second hydraulically controlled check valve;

[0035] 12. Check valve; 13. First sequence valve; 14. Second sequence valve.

[0036] 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

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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 solidify under pressure. In existing hydraulic clamping technology for die-casting machines, a single hydraulic cylinder is typically used for clamping. This single-cylinder structure has several limitations: firstly, to generate sufficient clamping force, the diameter of the single cylinder often needs to be large, which not only increases the difficulty of assembling and disassembling the cylinder but also necessitates specially made sealing rings, leading to a significant increase in maintenance costs; secondly, the hydraulic valve controlling the single cylinder requires a large diameter, resulting in high procurement costs, slow response speed, 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.

[0041] Therefore, researchers in this field have begun to explore the use of multi-cylinder structures for mold-locking operations. In the gear-aligning stage before mold-locking, the faster-responding double-acting cylinder in the multi-cylinder structure drives the slower-responding single-acting cylinder to extend and retract, thereby aligning the brake device with the teeth on the guide post. However, due to back pressure, the retraction of the piston rod of the single-acting cylinder generates significant resistance, leading to increased energy consumption and reduced gear-aligning efficiency. Furthermore, the piston rod of the single-acting cylinder is prone to cavitation when passively extended, which can damage the hydraulic system.

[0042] To address the aforementioned issues, this invention provides a multi-cylinder gear-mounted oil replenishment and drainage hydraulic circuit, aiming to reduce the back pressure that a single-acting cylinder needs to overcome during retraction and to replenish oil to the single-acting cylinder in a timely manner during extension to prevent cavitation.

[0043] Please see Figure 1 and Figure 2 The multi-cylinder gear-aligned oil supply and drainage hydraulic circuit provided by this utility model includes a mold-locking cylinder 1, an oil supply device 4, a cartridge valve 5, and a control device; wherein:

[0044] The mold-locking cylinder 1 includes a double-acting cylinder 101 and a single-acting cylinder 102. The piston rods of the double-acting cylinder 101 and the single-acting cylinder 102 are connected to the brake mechanism. The oil supply device 4 is used to supply oil to the double-acting cylinder 101. The cartridge valve 5 includes a control port X and a replenishment / relief oil passage. The control port X is connected to the first oil tank 6. The two ends of the replenishment / relief oil passage are respectively connected to the low-pressure pump 7 and the rodless chamber of the single-acting cylinder 102.

[0045] When the oil supply device 4 supplies oil to the rodless chamber of the double-acting cylinder 101, the piston rod of the double-acting cylinder 101 extends and drives the piston rod of the single-acting cylinder 102 to extend through the brake mechanism. The control device controls the oil at the control port X to enter the first oil tank 6, thereby making the replenishment and discharge oil circuit bidirectionally open, so that the pressure in the rodless chamber of the single-acting cylinder 102 is consistent with the working pressure of the low-pressure pump 7, so that the oil in the low-pressure pump 7 is replenished into the rodless chamber of the single-acting cylinder 102 through the replenishment and discharge oil circuit.

[0046] When the oil supply device 4 supplies oil to the rod chamber of the double-acting cylinder 101, 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 brake mechanism. The control device controls the oil in the control port X to enter the first oil tank 6, thereby opening the two-way oil supply and drainage circuit. This makes the pressure in the rodless chamber of the single-acting cylinder 102 more consistent with the working pressure of the low-pressure pump 7, so that the oil in the rodless chamber of the single-acting cylinder 102 is discharged to the low-pressure pump 7 through the oil supply and drainage circuit.

[0047] The multi-cylinder gear-mounted oil replenishment and drainage hydraulic circuit provided in this embodiment is applied to a die-casting machine. Specifically, the die-casting machine includes a fixed template (not shown in the figure) and a moving template 3. The fixed template is provided with a fixed mold (not shown in the figure) and a guide post (not shown in the figure). The moving template 3 is slidably fitted onto the guide post along the length direction of the guide post. A moving mold (not shown in the figure) is provided on the side of the moving template 3 facing the fixed template. The moving template 3 can move in the direction close to the fixed template under the drive of the mold-moving cylinder so that the moving mold and the fixed mold fit together.

[0048] Hydraulic oil can be supplied to both the rod chamber and the rodless chamber of the double-acting cylinder 101, so that the piston rod of the double-acting cylinder 101 can be driven to extend or retract using the pressure of the hydraulic oil. The cylinder body of the double-acting cylinder 101 is connected to the side of the moving template 3 facing away from the fixed template, and the piston rod of the double-acting cylinder 101 is connected to the fixed plate 2.

[0049] 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 3 facing away from the fixed template, and the piston rod of the single-acting cylinder 102 is connected to the fixed plate 2.

[0050] 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.

[0051] A brake mechanism can be installed on the fixed plate 2. The brake mechanism needs to engage with the teeth of the guide post to fix the fixed plate 2 and the guide post. Subsequently, when the piston rods of the double-acting cylinder 101 and the single-acting cylinder 102 extend, since the fixed plate 2 is in a fixed state, it will drive the cylinder bodies of the double-acting cylinder 101 and the single-acting cylinder 102 to move away from the fixed plate 2 in the opposite direction. Thus, the cylinder bodies of the double-acting cylinder 101 and the single-acting cylinder 102 apply force to the moving template 3, so that the moving mold on the moving template 3 is tightly pressed with the fixed mold on the fixed template to complete the mold locking operation.

[0052] When die-casting different products, due to differences in the specifications and dimensions of the fixed mold and the moving mold (specifically, differences in their thicknesses), the brake mechanism may be in different positions relative to the teeth of the guide post after the moving mold and the fixed mold are engaged under the drive of the mold-moving cylinder. When the brake mechanism and the teeth of the guide post are not aligned, the brake mechanism cannot engage with the teeth of the guide post. Therefore, a tooth alignment operation is required before the mold-locking operation, that is, the piston rod of the double-acting cylinder 101 is extended or retracted to move the brake mechanism back and forth relative to the guide post until the brake mechanism and the teeth of the guide post are aligned. During the process of the brake mechanism moving along the length of the guide post driven by the double-acting cylinder 101, the brake mechanism will also simultaneously drive the piston rod of the single-acting cylinder 102 to extend or retract.

[0053] The oil supply device 4 can be an oil pump. When the oil supply device 4 supplies oil to the rodless chamber of the double-acting cylinder 101, it can drive the piston rod of the double-acting cylinder 101 to extend; when the oil supply device 4 supplies oil to the rod chamber of the double-acting cylinder 101, it can drive the piston rod of the double-acting cylinder 101 to retract.

[0054] The valve core of cartridge valve 5 divides its valve sleeve into a first chamber and a second chamber. The first chamber is filled with pilot oil. Under the pressure of the pilot oil, the valve core of cartridge valve 5 is in the first position and blocks the replenishment and discharge oil passage in the second chamber. When the pilot oil in the first chamber flows outward to the first oil tank 6, the pressure of the pilot oil on the valve core of cartridge valve 5 decreases. The valve core will move to the second position under the external force provided by the spring and other devices. At this time, the valve core no longer blocks the replenishment and discharge oil passage in the second chamber. That is, the replenishment and discharge oil passage is in a bidirectional open state. This allows the low-pressure pump 7 at both ends of the replenishment and discharge oil passage and the rodless chamber of the single-acting cylinder 102 to be connected, so that the pressure of the rodless chamber of the single-acting cylinder 102 is consistent with the working pressure of the low-pressure pump 7.

[0055] The control device may include a controller, a microcontroller, a microcontroller unit (MCU), and supporting electronic components and connectors, possessing basic signal input / output, data storage and retrieval, and logical judgment functions. The control device is electrically connected to the oil supply device 4. When the control device receives a signal from the oil supply device 4 that it is supplying oil to the double-acting cylinder 101, it triggers a preset program to automatically control the cartridge valve 5 to perform an oil discharge operation. Specifically, the control device can be directly connected to the cartridge valve 5 to directly control the valve core movement of the cartridge valve 5, causing the pilot oil at control port X to drain to the first oil tank 6. Alternatively, the control device can be connected to a control valve located on the oil line between control port X and the first oil tank 6, thereby changing the working position of the control valve to control the on / off state of the oil line, thus indirectly controlling the pilot oil at control port X to drain to the first oil tank 6 through the control valve.

[0056] Based on the above settings, the specific operation process of this embodiment is as follows:

[0057] During the gear alignment stage, when the position of the teeth on the guide post is closer to the moving template 3 relative to the position of the brake mechanism, the oil supply device 4 supplies oil to the rod chamber of the double-acting cylinder 101, causing the piston rod of the double-acting cylinder 101 to retract and, through the brake mechanism (specifically through the fixed plate 2), drive the piston rod of the single-acting cylinder 102 to retract. At this time, the brake mechanism will move in the direction closer to the moving template 3 and gradually align with the teeth. Simultaneously, the control device will control the oil at the control port X to enter the first oil tank 6, thus opening the two-way oil supply and drainage circuit, causing the pressure in the rodless chamber of the single-acting cylinder 102 to match that of the low-pressure pump 7. The working pressure tends to be consistent; since the working pressure of the low-pressure pump 7 is relatively small, the back pressure effect it generates on the piston rod of the single-acting cylinder 102 is relatively small. When the piston rod of the single-acting cylinder 102 retracts, the oil in the rodless chamber of the single-acting cylinder 102 can smoothly flow back to the low-pressure pump 7 along the replenishment and drainage oil circuit with less resistance. This avoids the obstruction of the retraction action of the piston rod of the single-acting cylinder 102 due to excessive resistance, ensuring the rapid response of the single-acting cylinder 102 in the retraction action, and reducing the energy consumption caused by overcoming the back pressure effect, so that the hydraulic system can achieve good energy-saving effect.

[0058] When the position of the brake mechanism is closer to the moving template 3 relative to the position of the teeth on the guide post, the oil supply device 4 supplies oil to the rodless chamber of the double-acting cylinder 101, causing the piston rod of the double-acting cylinder 101 to extend and drive the piston rod of the single-acting cylinder 102 to extend through the brake mechanism (specifically through the fixed plate 2). At this time, the brake mechanism will move away from the moving template 3 and gradually align with the teeth. At the same time, the control device will control the oil in the control port X to enter the first oil tank 6, so that the replenishment and discharge oil circuit is bidirectional, making the pressure in the rodless chamber of the single-acting cylinder 102 more consistent with the working pressure of the low-pressure pump 7. This allows the oil in the low-pressure pump 7 to be smoothly replenished into the rodless chamber of the single-acting cylinder 102 through the replenishment and discharge oil circuit. This avoids the phenomenon of cavitation in the single-acting cylinder 102 during the passive extension of the piston rod, thus preventing damage to the hydraulic system caused by cavitation.

[0059] Therefore, in the multi-cylinder gear-aligning oil replenishment and drainage hydraulic circuit provided in this embodiment, the rodless chamber of the single-acting cylinder 102 is connected to the low-pressure pump 7 through the replenishment and drainage oil passage of the cartridge valve 5. When the piston rod of the single-acting cylinder 102 is passively retracted during gear alignment, the replenishment and drainage oil passage in the cartridge valve 5 switches to a bidirectional conduction state, making the pressure in the rodless chamber of the single-acting cylinder 102 more consistent with the working pressure of the low-pressure pump 7. Since the working pressure of the low-pressure pump 7 is relatively low, the back pressure it generates on the piston rod of the single-acting cylinder 102 is relatively small. The oil in the rodless chamber of the single-acting cylinder 102 can smoothly flow back to the low-pressure pump 7 along the replenishment and drainage oil passage with relatively low resistance, which can avoid damage to the single-acting cylinder due to excessive resistance. The retraction of the piston rod of cylinder 102 creates resistance, ensuring a rapid response of the single-acting cylinder 102 in the retraction action and reducing the energy consumption caused by overcoming back pressure, thus enabling the hydraulic system to achieve good energy-saving effects. When the piston rod of the single-acting cylinder 102 is passively extended during the gear alignment process, the replenishment and discharge oil circuit in the cartridge valve 5 also switches to a bidirectional conduction state, making the pressure in the rodless chamber of the single-acting cylinder 102 more consistent with the working pressure of the low-pressure pump 7. This allows the oil from the low-pressure pump 7 to be smoothly replenished into the rodless chamber of the single-acting cylinder 102 through the replenishment and discharge oil circuit, thereby preventing the single-acting cylinder 102 from sucking in air and thus avoiding damage to the hydraulic system caused by air sucking in air.

[0060] In one embodiment, refer to Figure 1 and Figure 2 The cartridge valve 5 includes a first working port A1 and a second working port B1. The oil passage between the first working port A1 and the second working port B1 constitutes a refill and drain oil passage. The first working port A1 is connected to the low-pressure pump 7, and the second working port B1 is connected to the rodless chamber of the single-acting cylinder 102.

[0061] Specifically, under the pressure of the pilot oil, the valve core of the cartridge valve 5 is normally blocked between the first working port A1 and the second working port B1, and the replenishment and discharge oil circuit is in a closed state. The rodless chamber of the single-acting cylinder 102 is not connected to the low-pressure pump 7. When the pilot oil flows outward to the first oil tank 6, the pressure generated by the pilot oil on the valve core of the cartridge valve 5 decreases. The valve core will move to another position under the external force provided by the spring and other devices, so that the first working port A1 and the second working port B1 are connected. That is, at this time, the replenishment and discharge oil circuit is in a bidirectional state. In this way, the oil in the rodless chamber of the single-acting cylinder 102 can be discharged to the low-pressure pump 7 through the second working port B1 and the first working port A1 in sequence, or the oil in the low-pressure pump 7 can be replenished into the rodless chamber of the single-acting cylinder 102 through the first working port A1 and the second working port B1 in sequence.

[0062] In one embodiment, refer to Figure 1 and Figure 2The multi-cylinder gear-matching oil replenishment and oil discharge hydraulic circuit also includes a first directional valve 8, which is set in the oil line between the control oil port X and the first oil tank 6.

[0063] When the first reversing valve 8 is in the first reversing position, the first reversing valve 8 is used to prevent the oil from the control port X from entering the first oil tank 6;

[0064] When the oil supply device 4 supplies oil to the double-acting cylinder 101, the control device controls the first reversing valve 8 to be energized and switch to the second reversing position, so that the oil in the control port X enters the first oil tank 6 through the first reversing valve 8.

[0065] The first directional valve 8 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 first directional valve 8 can switch between the first directional position and the second directional position by the change of the valve core position, so as to realize the opening or closing of the oil circuit, thereby controlling the opening and closing and the flow direction of hydraulic oil.

[0066] In practical applications, the first directional valve 8 is initially in the first reversing position. At this time, the oil passage between the control port X of the cartridge valve 5 and the first oil tank 6 is closed. The pilot oil from the control port X continuously exerts pressure on the valve core of the cartridge valve 5, causing the valve core to overcome the external force of the spring and other devices and remain in the first position, thus blocking the oil passage between the first working port A1 and the second working port B1. When the oil supply device 4 supplies oil to the double-acting cylinder 101, the control device controls the first directional valve 8 to be energized and switch to the second reversing position. At this time, the oil passage between the control port X of the cartridge valve 5 and the first oil tank 6 is open. The pilot oil from the control port X will be discharged to the first oil tank 6 through the first directional valve 8 to complete the pressure relief. At this time, the pressure of the pilot oil on the valve core of the cartridge valve 5 decreases, and the valve core of the cartridge valve 5 will move to the second position under the external force of the spring and other devices, thus opening the oil passage between the first working port A1 and the second working port B1.

[0067] In this embodiment, by setting a first directional valve 8, the flow direction, flow rate and flow velocity of the oil can be precisely controlled, thereby meeting the high-precision control requirements of the hydraulic system.

[0068] In one embodiment, refer to Figure 1 and Figure 2 The first reversing valve 8 includes a third working oil port A2 and a fourth working oil port B2. The third working oil port A2 is connected to the first oil tank 6, and the fourth working oil port B2 is connected to the control oil port X.

[0069] When the first directional valve 8 is in the first directional position, the oil passage between the third working port A2 and the fourth working port B2 is unidirectionally connected; when the first directional valve 8 is in the second directional position, the oil passage between the third working port A2 and the fourth working port B2 is bidirectionally connected.

[0070] In this embodiment, the first reversing valve 8 is initially in the first reversing position, with the third working port A2 to the fourth working port B2 being unidirectionally connected. At this time, it is convenient to supply the oil from the first oil tank 6 to the control port X of the cartridge valve 5, while preventing the oil from the control port X from flowing back to the first oil tank 6. This ensures that the pilot oil from the control port X can generate sufficient pressure on the valve core of the cartridge valve 5, so that the valve core is stably kept in the first position (blocking the oil passage between the first working port A1 and the second working port B1). When the oil supply device 4 supplies oil to the double-acting cylinder 101, the control device will energize the first reversing valve 8 and switch it to the second reversing position. At this time, the oil circuit between the third working port A2 and the fourth working port B2 is in a bidirectional flow state. The oil can flow from the end with higher pressure (i.e., the control port X of the cartridge valve 5) to the end with lower pressure (i.e., the first oil tank 6), so that the valve core moves to the second position (the oil circuit between the first working port A1 and the second working port B1 is connected).

[0071] In one embodiment, refer to Figure 1 and Figure 2 The multi-cylinder gear-type oil replenishment and discharge hydraulic circuit also includes a second directional valve 9 and a second oil tank 10; the second directional valve 9 includes an oil inlet P, an oil return T, a fifth working oil port A3 and a sixth working oil port B3, the oil inlet P is connected to the oil supply device 4, the oil return T is connected to the second oil tank 10, the fifth working oil port A3 is connected to the rod chamber of the double-acting cylinder 101, and the sixth working oil port B3 is connected to the rodless chamber of the double-acting cylinder 101;

[0072] When the second reversing valve 9 is in the first reversing state, the oil supply device 4 supplies oil to the rodless chamber of the double-acting cylinder 101 through the sixth working oil port B3, so that the piston rod of the double-acting cylinder 101 extends.

[0073] When the second reversing valve 9 is in the second reversing state, the oil supply device 4 supplies oil to the rod chamber of the double-acting cylinder 101 through the fifth working oil port A3, so that the piston rod of the double-acting cylinder 101 retracts.

[0074] Specifically, the second directional valve 9 can be a solenoid valve, whose valve core slides in the valve body. When the electromagnet is energized, it can attract the valve core, thereby changing the position of the valve core in the valve body by energizing or de-energizing the electromagnet. In turn, the second directional valve 9 can switch between different directional positions by changing the position of the valve core, so as to realize the selection between the oil inlet P, the oil return T and the fifth working oil port A3 and the sixth working oil port B3, so as to control the on-off and flow direction of hydraulic oil.

[0075] Based on the above settings, the specific tooth alignment process is as follows:

[0076] When the position of the brake mechanism is closer to the moving template 3 relative to the position of the teeth on the guide post, the second reversing valve 9 switches to the first reversing state. At this time, the oil supply device 4 supplies oil to the rodless chamber of the double-acting cylinder 101 through the oil inlet P and the sixth working oil port B3 of the second reversing valve 9 in sequence. This causes the piston rod of the double-acting cylinder 101 to extend quickly and, through the brake mechanism (specifically through the fixed plate 2), causes the piston rod of the single-acting cylinder 102 to extend quickly, so that the brake mechanism moves away from the moving template 3 and gradually aligns with the teeth of the guide post.

[0077] When the position of the teeth on the guide post is closer to the moving template 3 relative to the position of the brake mechanism, the second reversing valve 9 switches to the second reversing state. At this time, the oil supply device 4 supplies oil to the rod chamber of the double-acting cylinder 101 through the oil inlet P and the fifth working oil port A3 of the second reversing valve 9 in sequence. This drives the piston rod of the double-acting cylinder 101 to retract quickly and, through the brake mechanism (specifically through the fixed plate 2), drives the piston rod of the single-acting cylinder 102 to retract quickly, so that the brake mechanism moves in the direction closer to the moving template 3 and gradually aligns with the teeth of the guide post.

[0078] In this embodiment, by setting a second reversing valve 9, the flow direction, flow rate and flow velocity of the oil supplied by the oil supply device 4 can be precisely controlled to meet the high precision requirements of the gear process.

[0079] In one embodiment, refer to Figure 1 and Figure 2 When the second reversing valve 9 is in the first reversing state, the oil inlet P is connected to the sixth working oil port B3, and the oil return port T is connected to the fifth working oil port A3. The oil in the rod chamber of the double-acting cylinder 101 is discharged to the second oil tank 10 through the fifth working oil port A3.

[0080] In one embodiment, refer to Figure 1 and Figure 2 When the second reversing valve 9 is in the second reversing state, the oil inlet P is connected to the fifth working oil port A3, and the oil return port T is connected to the sixth working oil port B3. The oil in the rodless chamber of the double-acting cylinder 101 is discharged to the second oil tank 10 through the sixth working oil port B3.

[0081] Specifically, when the position of the brake mechanism is closer to the moving template 3 relative to the position of the teeth on the guide post, the second reversing valve 9 switches to the first reversing state. At this time, the oil supply device 4 supplies oil to the rodless chamber of the double-acting cylinder 101 through the oil inlet P and the sixth working oil port B3 of the second reversing valve 9 in sequence. This drives the piston rod of the double-acting cylinder 101 to extend quickly and, through the brake mechanism (specifically through the fixed plate 2), drives the piston rod of the single-acting cylinder 102 to extend quickly, so that the brake mechanism moves away from the moving template 3 and gradually aligns with the teeth of the guide post. During this process, the piston rod of the double-acting cylinder 101 will 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 discharged through the fifth working oil port A3 and the return oil port T of the second reversing valve 9 in sequence to the second oil tank 10, thereby ensuring that the piston rod of the double-acting cylinder 101 can extend smoothly.

[0082] When the position of the teeth on the guide post is closer to the moving template 3 relative to the position of the brake mechanism, the second reversing valve 9 switches to the second reversing state. At this time, the oil supply device 4 supplies oil to the rod chamber of the double-acting cylinder 101 through the oil inlet P and the fifth working oil port A3 of the second reversing valve 9 in sequence. This drives the piston rod of the double-acting cylinder 101 to retract quickly and, through the brake mechanism (specifically through the fixed plate 2), drives the piston rod of the single-acting cylinder 102 to retract quickly, so that the brake mechanism moves in the direction closer to the moving template 3 and gradually aligns with the teeth of the guide post. During this process, the piston rod of the double-acting cylinder 101 will 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 discharged through the sixth working oil port B3 and the return oil port T of the second reversing valve 9 in sequence to the second oil tank 10, thereby ensuring that the piston rod of the double-acting cylinder 101 can retract smoothly.

[0083] This embodiment ensures that the oil in the compressed cavity of the double-acting cylinder 101 can be discharged to the second oil tank 10 through the second reversing valve 9, thereby ensuring that the piston rod of the double-acting cylinder 101 can extend and retract normally.

[0084] In one embodiment, refer to Figure 1 and Figure 2 The multi-cylinder gear-type oil replenishment and oil discharge hydraulic circuit also includes a two-way hydraulic lock 11, which includes a first hydraulic control check valve 1101 and a second hydraulic control check valve 1102.

[0085] The first hydraulic control check valve 1101 is installed in the oil line between the fifth working oil port A3 and the rod chamber of the double-acting cylinder 101. When the control port of the first hydraulic control check valve 1101 is not supplied with oil, the first hydraulic control check valve 1101 is used to prevent the oil in the rod chamber of the double-acting cylinder 101 from flowing to the fifth working oil port A3.

[0086] The second hydraulic control check valve 1102 is installed in the oil line between the sixth working oil port B3 and the rodless chamber of the double-acting cylinder 101. When the control port of the second hydraulic control check valve 1102 is not supplied with oil, the second hydraulic control check valve 1102 is used to prevent the oil in the rodless chamber of the double-acting cylinder 101 from flowing to the sixth working oil port B3.

[0087] In this embodiment, the control port of the first hydraulic check valve 1101 is connected to the oil inlet of the second hydraulic check valve 1102, and the control port of the second hydraulic check valve 1102 is connected to the oil inlet of the first hydraulic check valve 1101. When the oil supply device 4 does not supply oil to the oil circuit where the first hydraulic check valve 1101 is located through the second directional valve 9, no oil enters the control port of the second hydraulic check valve 1102. At this time, the second hydraulic check valve 1102 is in a one-way open state, which can prevent the oil in the rodless chamber of the double-acting cylinder 101 from flowing towards the second directional valve 9. Similarly, when the oil supply device 4 does not supply oil to the oil circuit where the second hydraulic check valve 1102 is located through the second directional valve 9, no oil enters the control port of the first hydraulic check valve 1101. At this time, the first hydraulic check valve 1101 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 second directional valve 9. Based on the above settings, oil leakage in the double-acting cylinder 101 can be avoided when it is not in operation.

[0088] During the gear-aligning stage, when the oil supply device 4 supplies oil to the rodless chamber of the double-acting cylinder 101 through the second hydraulic check valve 1102, the oil flowing through the second hydraulic check valve 1102 will simultaneously flow into the control port of the first hydraulic check valve 1101, causing the first hydraulic check valve 1101 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 second oil tank 10 through the first hydraulic check valve 1101 and the second directional valve 9 in sequence, preventing the piston rod of the double-acting cylinder 101 from extending. When the oil supply device 4 supplies oil to the rod chamber of the double-acting cylinder 101 through the first hydraulic check valve 1101, the oil flowing through the first hydraulic check valve 1101 will simultaneously flow into the control port of the second hydraulic check valve 1102, causing the second hydraulic check valve 1102 to enter a bidirectional conduction state. At this time, the oil in the rodless chamber of the double-acting cylinder 101 can be discharged to the second oil tank 10 through the second hydraulic check valve 1102 and the second reversing valve 9 in sequence, thus avoiding obstruction of the retraction action of the piston rod of the double-acting cylinder 101.

[0089] This embodiment, by setting a bidirectional hydraulic lock 11, avoids oil leakage during non-working phases while ensuring normal oil drainage in the corresponding chambers of the double-acting cylinder 101 during gear-aligning phases, ensuring that the piston rod of the double-acting cylinder 101 can extend and retract normally, thereby further improving the control accuracy and operational reliability of the system.

[0090] In one embodiment, refer to Figure 1 and Figure 2 The multi-cylinder gear-type oil replenishment and discharge hydraulic circuit also includes a one-way valve 12; the one-way valve 12 is set 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.

[0091] Specifically, the one-way valve 12 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 12 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 configuration, during the gear-aligning stage, when the oil supply device 4 needs to supply oil to the rodless chamber of the double-acting cylinder 101 through the second directional valve 9, it can prevent 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 piston rod of the single-acting cylinder 102 is in a follow-up state.

[0092] In one embodiment, refer to Figure 1 and Figure 2 The multi-cylinder gear-type oil replenishment and discharge hydraulic circuit also includes a first sequence valve 13. The oil inlet of the first sequence valve 13 is connected to the rod chamber of the double-acting cylinder 101, the oil outlet of the first sequence valve 13 is connected to the second oil tank 10, and the control end of the first sequence valve 13 is connected to the rod chamber of the double-acting cylinder 101.

[0093] Specifically, the first sequence valve 13 is in the closed state during normal system operation. When the oil in the rod chamber of the double-acting cylinder 101 cannot be discharged normally, causing the pressure in the rod chamber of the double-acting cylinder 101 to rise to the preset pressure value of the first sequence valve 13, the oil reaching a certain pressure will push the valve core to move through the control end of the first sequence valve 13, causing the first sequence valve 13 to switch to a one-way conduction state. At this time, the oil in the rod chamber of the double-acting cylinder 101 can be discharged to the second oil tank 10 through the first sequence valve 13. In this way, the pressure relief of the rod chamber of the double-acting cylinder 101 can be achieved when the oil circuit is blocked, avoiding damage to the double-acting cylinder 101 due to abnormal high pressure, thereby improving the reliability and safety of the system.

[0094] In one embodiment, refer to Figure 1 and Figure 2 The multi-cylinder gear-type oil replenishment and discharge hydraulic circuit also includes a second sequence valve 14. The oil inlet of the second sequence valve 14 is connected to the rodless chamber of the double-acting cylinder 101, the oil outlet of the second sequence valve 14 is connected to the rodless chamber of the single-acting cylinder 102, and the control end of the second sequence valve 14 is connected to the rodless chamber of the double-acting cylinder 101.

[0095] Specifically, the second sequence valve 14 is in the closed state during normal system operation. When the oil in the rodless chamber of the double-acting cylinder 101 cannot be discharged normally, causing the pressure in the rodless chamber of the double-acting cylinder 101 to rise to the preset pressure value of the second sequence valve 14, the oil reaching a certain pressure will push the valve core to move through the control end of the second sequence valve 14, causing the second sequence valve 14 to switch to a one-way conduction state. At this time, the oil in the rodless chamber of the double-acting cylinder 101 can be discharged to the single-acting cylinder 102 through the second sequence valve 14. In this way, the pressure relief of the rodless chamber of the double-acting cylinder 101 can be achieved when the oil circuit is blocked, avoiding damage to the double-acting cylinder 101 due to abnormal high pressure, thereby improving the reliability and safety of the system.

[0096] This utility model embodiment also provides a die-casting machine, please refer to [link / reference]. Figure 1 and Figure 2 The die-casting machine includes a multi-cylinder gear-pairing oil replenishment and drainage hydraulic circuit in any of the above embodiments.

[0097] In this embodiment, the die-casting machine can specifically be a two-plate die-casting machine. For the specific structure of the multi-cylinder gear-aligning oil replenishment and drainage hydraulic circuit, 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, the rodless chamber of the single-acting cylinder 102 is connected to the low-pressure pump 7 through the replenishment and drainage oil passage of the cartridge valve 5; when the piston rod of the single-acting cylinder 102 is passively retracted during gear alignment, the replenishment and drainage oil passage in the cartridge valve 5 switches to a bidirectional conduction state, making the pressure of the rodless chamber of the single-acting cylinder 102 tend to be consistent with the working pressure of the low-pressure pump 7. Since the working pressure of the low-pressure pump 7 is relatively small, the back pressure effect it generates on the piston rod of the single-acting cylinder 102 is relatively small, and the oil in the rodless chamber of the single-acting cylinder 102 can smoothly flow back to the low-pressure pump 7 along the replenishment and drainage oil passage with relatively small resistance. This avoids obstructing the retraction of the piston rod of the single-acting cylinder 102 due to excessive resistance, ensuring a rapid response of the single-acting cylinder 102 in the retraction action, and reducing the energy consumption caused by overcoming back pressure, thus enabling the hydraulic system to achieve good energy-saving effects. When the piston rod of the single-acting cylinder 102 is passively extended during the gear-aligning process, the replenishment and discharge oil circuit in the cartridge valve 5 also switches to a bidirectional conduction state, making the pressure in the rodless chamber of the single-acting cylinder 102 more consistent with the working pressure of the low-pressure pump 7. This allows the oil from the low-pressure pump 7 to be smoothly replenished into the rodless chamber of the single-acting cylinder 102 through the replenishment and discharge oil circuit, thus avoiding the phenomenon of cavitation in the single-acting cylinder 102, thereby preventing damage to the hydraulic system caused by cavitation.

[0098] It should be noted that the other contents of the multi-cylinder gear oil replenishment and drainage hydraulic circuit and die-casting machine disclosed in this utility model can be found in the prior art, and will not be repeated here.

[0099] 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 multi-cylinder gear-mounted oil supply and drainage hydraulic circuit, characterized in that, Includes a mold-locking cylinder, an oil supply device, a cartridge valve, and a control device; wherein: The mold-locking cylinder includes a double-acting cylinder and a single-acting cylinder. The piston rods of the double-acting cylinder and the single-acting cylinder are connected to the brake mechanism. The oil supply device is used to supply oil to the double-acting cylinder. The cartridge valve includes a control port and a replenishment / relief oil passage. The control port is connected to the first oil tank. The two ends of the replenishment / relief oil passage are respectively connected to the low-pressure pump and the rodless chamber of the single-acting cylinder. When the oil supply device supplies oil to the rodless chamber of the double-acting cylinder, the piston rod of the double-acting cylinder extends and drives the piston rod of the single-acting cylinder to extend through the brake mechanism. The control device controls the oil in the control port to enter the first oil tank, thereby opening the two-way flow of the replenishment and discharge oil circuit. This makes the pressure in the rodless chamber of the single-acting cylinder more consistent with the working pressure of the low-pressure pump, so that the oil in the low-pressure pump is replenished into the rodless chamber of the single-acting cylinder through the replenishment and discharge oil circuit. When the oil supply device supplies oil to the rod chamber of the double-acting cylinder, the piston rod of the double-acting cylinder retracts and drives the piston rod of the single-acting cylinder to retract through the brake mechanism. The control device controls the oil in the control port to enter the first oil tank, thereby opening the two-way flow path of the replenishment and discharge oil circuit. This causes the pressure in the rodless chamber of the single-acting cylinder to become consistent with the working pressure of the low-pressure pump, so that the oil in the rodless chamber of the single-acting cylinder is discharged to the low-pressure pump through the replenishment and discharge oil circuit.

2. The multi-cylinder gear-aligned oil replenishment and drainage hydraulic circuit as described in claim 1, characterized in that, The cartridge valve includes a first working port and a second working port, and the oil passage between the first working port and the second working port constitutes the refill and drain oil passage; the first working port is connected to the low-pressure pump, and the second working port is connected to the rodless chamber of the single-acting cylinder.

3. The multi-cylinder gear-aligned oil replenishment and drainage hydraulic circuit as described in claim 1, characterized in that, The multi-cylinder gear-matching oil replenishment and discharge hydraulic circuit also includes a first reversing valve, which is disposed on the oil line between the control oil port and the first oil tank. When the first reversing valve is in the first reversing position, the first reversing valve is used to prevent the oil from the control port from entering the first oil tank. When the oil supply device supplies oil to the double-acting cylinder, the control device controls the first reversing valve to be energized and switch to the second reversing position, so that the oil in the control port enters the first oil tank through the first reversing valve.

4. The multi-cylinder gear-aligned oil replenishment and drainage hydraulic circuit as described in claim 3, characterized in that, The first reversing valve includes a third working port and a fourth working port. The third working port is connected to the first oil tank, and the fourth working port is connected to the control port. When the first reversing valve is in the first reversing position, the oil passage between the third working port and the fourth working port is unidirectionally connected; when the first reversing valve is in the second reversing position, the oil passage between the third working port and the fourth working port is bidirectionally connected.

5. The multi-cylinder gear-matching oil replenishment and drainage hydraulic circuit as described in claim 1, characterized in that, The multi-cylinder gear-matching oil replenishment and discharge hydraulic circuit also includes a second reversing valve and a second oil tank; the second reversing valve includes an oil inlet, an oil return port, a fifth working oil port and a sixth working oil port, the oil inlet is connected to the oil supply device, the oil return port is connected to the second oil tank, the fifth working oil port is connected to the rod chamber of the double-acting cylinder, and the sixth working oil port is connected to the rodless chamber of the double-acting cylinder; When the second reversing valve is in the first reversing state, the oil supply device supplies oil to the rodless chamber of the double-acting cylinder through the sixth working oil port, so that the piston rod of the double-acting cylinder extends. When the second reversing valve is in the second reversing state, the oil supply device supplies oil to the rod chamber of the double-acting cylinder through the fifth working oil port, so that the piston rod of the double-acting cylinder retracts.

6. The multi-cylinder gear-aligned oil replenishment and drainage hydraulic circuit as described in claim 5, characterized in that, When the second reversing valve is in the first reversing state, the oil inlet is connected to the sixth working oil port, the oil return port is connected to the fifth working oil port, and the oil in the rod chamber of the double-acting cylinder is discharged to the second oil tank through the fifth working oil port. And / or, when the second reversing valve is in the second reversing state, the oil inlet is connected to the fifth working oil port, the oil return port is connected to the sixth working oil port, and the oil in the rodless chamber of the double-acting cylinder is discharged to the second oil tank through the sixth working oil port.

7. The multi-cylinder gear-aligned oil replenishment and drainage hydraulic circuit as described in claim 5, characterized in that, The multi-cylinder gear-matching oil replenishment and oil discharge hydraulic circuit 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 disposed in the oil line between the fifth working oil port and the rod chamber of the double-acting cylinder; when the control 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 fifth working oil port. The second hydraulic control check valve is disposed in the oil line between the sixth 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 sixth working port.

8. The multi-cylinder gear-aligned oil replenishment and drainage hydraulic circuit as described in claim 5, characterized in that, The multi-cylinder gear-matching oil replenishment and discharge hydraulic circuit also includes a one-way valve; the one-way valve is set 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. And / or, the multi-cylinder gear-pairing oil replenishment and discharge hydraulic circuit further includes a first sequence valve, the oil inlet of the first sequence valve is connected to the rod chamber of the double-acting cylinder, the oil outlet of the first sequence valve is connected to the second oil tank, and the control end of the first sequence valve is connected to the rod chamber of the double-acting cylinder.

9. The multi-cylinder gear-aligned oil replenishment and drainage hydraulic circuit as described in claim 8, characterized in that, The multi-cylinder gear-pairing oil replenishment and discharge hydraulic circuit also includes a second sequence valve. The oil inlet of the second sequence valve is connected to the rodless chamber of the double-acting cylinder, the oil outlet of the second sequence valve is connected to the rodless chamber of the single-acting cylinder, and the control end of the second sequence valve is connected to the rodless chamber of the double-acting cylinder.

10. A die-casting machine, characterized in that, The die-casting machine includes a multi-cylinder gear-matching oil replenishment and drainage hydraulic circuit as described in any one of claims 1 to 9.

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