Modular pressurized hydraulic circuit and die casting machine

Abstract

The utility model discloses a kind of mould locking pressurizing hydraulic circuit and die-casting machine, it is related to die-casting equipment technical field, including oil supply device, oil tank, pressurizing cylinder and mould locking cylinder;Pressurizing cylinder includes pressurizing oil inlet chamber, pressurizing oil return chamber and pressure building chamber;Oil supply device supplies oil to pressurizing oil inlet chamber and pressure building chamber, loop between pressurizing oil inlet chamber and pressure building chamber is equipped with first check valve;Pressure building chamber is communicated with mould locking cylinder rodless chamber;Pressurizing oil return chamber is communicated with oil tank, and oil passage between pressurizing oil return chamber and oil tank is equipped with first reversing valve;When the pressure of pressure building chamber reaches first pressure threshold, first reversing valve is powered to control the oil liquid of pressurizing oil return chamber flows into oil tank, so that the pressure of pressurizing oil inlet chamber is greater than the pressure of pressurizing oil return chamber, so that pressurizing piston rod is pressed into mould locking cylinder rodless chamber with the hydraulic oil of pressure building chamber.The scheme cancels accumulator, improves the pressure of mould locking cylinder under the precondition of not increasing system complexity and space requirement, can reduce cylinder diameter, reduce manufacturing and maintenance cost.

Description

Technical Field

[0001] This utility model relates to the field of die-casting equipment technology, and in particular to a mold-locking pressure boosting hydraulic circuit and a die-casting machine. Background Technology

[0002] In the die-casting machine production process, mold-locking operation is one of the key links to ensure product quality and production efficiency. Traditional die-casting machine mold-locking hydraulic systems usually rely on system pressure to directly drive the mold-locking cylinder to complete the mold-locking operation; however, this system has many limitations. First, since the system pressure of a die-casting machine is usually provided by a pump, its pressure is generally within 21MPa. Therefore, in order to generate sufficient mold-locking force, the diameter of the mold-locking cylinder often needs to be large, which not only increases the manufacturing cost of the cylinder but also makes the cylinder more difficult to install and disassemble. Second, in order to meet the sealing requirements of large-diameter cylinders, special sealing rings are usually required, which further increases maintenance costs. In addition, some existing technologies attempt to solve the above problems by using accumulators to provide boosted power, but accumulators have high space requirements and are difficult to implement on some compact die-casting machines.

[0003] Against this backdrop, how to effectively increase the pressure of the clamping cylinder without increasing system complexity and space requirements, thereby reducing the cylinder diameter and lowering manufacturing and maintenance costs, has become an urgent problem to be solved in the hydraulic clamping technology of die casting machines. Utility Model Content

[0004] The main purpose of this invention is to propose a mold-locking pressurization hydraulic circuit, which aims to increase the pressure of the mold-locking cylinder without increasing system complexity and space requirements, thereby reducing the cylinder diameter and lowering manufacturing and maintenance costs.

[0005] To achieve the above objectives, the present invention proposes a mold-locking and pressurizing hydraulic circuit for a die-casting machine, comprising an oil supply device, an oil tank, a pressurizing cylinder, and a mold-locking cylinder; wherein,

[0006] The booster cylinder is divided into two sections, a large section and a small section, and is equipped with a booster piston rod inside. The booster piston rod is divided into two sections, a large section and a small section. The large section of the booster piston rod is slidably disposed inside the large section of the booster cylinder, and the small section of the booster piston rod is slidably disposed inside the small section of the booster cylinder, so that the booster cylinder forms a booster oil inlet chamber, a booster oil return chamber and a pressure building chamber.

[0007] The oil supply device supplies hydraulic oil to the boosting oil inlet chamber and the pressure building chamber. A first check valve is provided in the connecting circuit between the boosting oil inlet chamber and the pressure building chamber. The pressure building chamber is connected to the rodless chamber of the mold locking cylinder. A pressure sensor is provided in the oil inlet circuit of the pressure building chamber. The boosting oil return chamber is connected to the oil tank. A first reversing valve is provided in the oil return circuit between the boosting oil return chamber and the oil tank. The first reversing valve is electrically connected to the pressure sensor.

[0008] When the pressure sensor detects that the pressure in the pressure-building chamber reaches the first pressure threshold, the first directional valve is energized to control the hydraulic oil in the booster return chamber to flow into the oil tank, so that the pressure in the booster inlet chamber is greater than the pressure in the booster return chamber, thereby causing the booster piston rod to press the hydraulic oil in the pressure-building chamber into the rodless chamber of the mold-locking cylinder.

[0009] In one embodiment, the mold-locking pressurizing hydraulic circuit further includes a second reversing valve, the oil supply device is connected to the pressurizing oil inlet chamber and the pressurizing oil return chamber through the second reversing valve, and the pressure sensor is electrically connected to the second reversing valve;

[0010] When the pressure sensor detects that the pressure in the pressure-building chamber reaches the second pressure threshold, the first directional valve is de-energized to prevent the hydraulic oil in the booster return chamber from flowing back to the oil tank, and the second directional valve is de-energized to prevent the oil supply device from supplying hydraulic oil to the booster inlet chamber and the pressure-building chamber; the second pressure threshold is greater than the first pressure threshold.

[0011] In one embodiment, the second reversing valve is configured as a solenoid reversing valve. The second reversing valve includes a first oil inlet, a first oil outlet, a first working oil port, and a second working oil port. The first oil inlet is connected to the oil supply device, the first oil outlet is connected to the oil tank, the first working oil port is connected to the booster return oil chamber, and the second working oil port is connected to the booster inlet oil chamber and the pressure building chamber.

[0012] In one embodiment, the first reversing valve is configured as a solenoid reversing valve, the first reversing valve includes a third working oil port and a fourth working oil port, the third working oil port is connected to the first working oil port, and the fourth working oil port is connected to the pressurized return oil chamber.

[0013] In one embodiment, a connection node is provided on the connecting circuit between the boosting oil inlet chamber and the pressure building chamber; the mold locking boosting hydraulic circuit further includes a second check valve, which is configured as a hydraulically controlled check valve, and is located between the connection node and the oil supply device, with the control port of the second check valve connected to the first working port.

[0014] In one embodiment, the first reversing valve is configured as a solenoid reversing valve, the first reversing valve including a third working oil port and a fourth working oil port, the third working oil port being connected to the oil tank, and the fourth working oil port being connected to the pressurized return oil chamber.

[0015] In one embodiment, a connection node is provided on the connecting oil line between the booster oil inlet chamber and the pressure building chamber; the mold locking booster hydraulic circuit further includes a second check valve, which is disposed between the connection node and the oil supply device.

[0016] In one embodiment, the mold-locking pressurizing hydraulic circuit further includes a position sensor connected to the pressurizing piston rod, the position sensor being used to acquire the real-time position of the pressurizing piston rod.

[0017] In one embodiment, the mold-locking cylinder includes a plurality of double-acting cylinders and a plurality of single-acting cylinders.

[0018] This utility model also proposes a die-casting machine, which includes the aforementioned mold-locking and pressurizing hydraulic circuit.

[0019] The hydraulic circuit for increasing mold clamping pressure provided by this utility model connects the booster cylinder and the mold clamping cylinder in series, and simultaneously supplies hydraulic oil to both cylinders. When the mold clamping pressure reaches a certain level, the hydraulic oil in the booster return chamber of the booster cylinder is discharged, creating a pressure difference between the booster return chamber and the booster inlet chamber. This pressure difference is used to further pressurize the hydraulic oil in the pressure-building chamber of the booster cylinder into the mold clamping cylinder, thereby increasing the mold clamping force generated by the mold clamping cylinder. This solution achieves mold clamping pressure increase without the need for an accumulator, that is, it increases the mold clamping pressure of the mold clamping cylinder by using a booster cylinder without using a large-diameter mold clamping cylinder or increasing system complexity and space requirements, thereby reducing the manufacturing and maintenance costs of the mold clamping cylinder and the die casting machine. Attached Figure Description

[0020] 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.

[0021] Figure 1 A schematic diagram of the hydraulic circuit structure of the mold-locking and pressurizing hydraulic circuit provided by this utility model in its initial state;

[0022] Figure 2A schematic diagram of the hydraulic circuit structure of the mold-locking and pressurizing hydraulic circuit provided by this utility model when it is in the initial mold-locking state;

[0023] Figure 3 A schematic diagram of the hydraulic circuit structure of the mold-locking and pressurizing hydraulic circuit provided by this utility model when it is in the pressurizing and mold-locking state;

[0024] Figure 4 A schematic diagram of the hydraulic circuit structure of the mold-locking and pressurizing hydraulic circuit provided by this utility model when it is in the pressure-holding state;

[0025] Figure 5 This is a partial structural schematic diagram of the die-casting machine provided by this utility model.

[0026] Explanation of icon numbers:

[0027] 1. Fuel supply device; 2. Fuel tank;

[0028] 3. Booster cylinder; 301. Booster piston rod; 302. Booster oil inlet chamber; 303. Booster oil return chamber; 304. Pressure building chamber;

[0029] 4. Mold clamping cylinder; 401. Double-acting cylinder; 402. Single-acting cylinder;

[0030] 5. First check valve; 6. Pressure sensor; 7. First directional valve; 8. Second directional valve; 9. Connection node; 10. Second check valve; 11. Position sensor; 12. Moving template; 13. Fixing plate.

[0031] 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

[0032] 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.

[0033] 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.

[0034] 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.

[0035] In the die-casting machine production process, mold-locking operation is one of the key links to ensure product quality and production efficiency. Traditional die-casting machine mold-locking hydraulic systems usually rely on system pressure to directly drive the mold-locking cylinder to complete the mold-locking operation; however, this system has many limitations. First, since the system pressure of a die-casting machine is usually provided by a pump, its pressure is generally within 21MPa. Therefore, in order to generate sufficient mold-locking force, the diameter of the mold-locking cylinder often needs to be large, which not only increases the manufacturing cost of the cylinder but also makes the cylinder more difficult to install and disassemble. Second, in order to meet the sealing requirements of large-diameter cylinders, special sealing rings are usually required, which further increases maintenance costs. In addition, some existing technologies attempt to solve the above problems by using accumulators to provide boosted power, but accumulators have high space requirements and are difficult to implement on some compact die-casting machines.

[0036] Against this backdrop, how to effectively increase the pressure of the clamping cylinder without increasing system complexity and space requirements, thereby reducing the cylinder diameter and lowering manufacturing and maintenance costs, has become an urgent problem to be solved in the hydraulic clamping technology of die casting machines.

[0037] To address the aforementioned issues, this invention provides a mold-locking pressurization hydraulic circuit that eliminates the need for an accumulator, thereby increasing the pressure of the mold-locking cylinder without increasing system complexity or space requirements, thus reducing cylinder diameter and manufacturing and maintenance costs.

[0038] Please see Figures 1 to 4 The die-casting machine's mold-locking and pressurizing hydraulic circuit provided by this utility model includes an oil supply device 1, an oil tank 2, a pressurizing cylinder 3, and a mold-locking cylinder 4; wherein,

[0039] The booster cylinder 3 is divided into two sections, large and small, and is equipped with a booster piston rod 301 inside. The booster piston rod 301 is divided into two sections, large and small. The large section of the booster piston rod 301 is slidably disposed in the large section of the booster cylinder 3, and the small section of the booster piston rod 301 is slidably disposed in the small section of the booster cylinder 3, so that the booster cylinder 3 forms a booster oil inlet chamber 302, a booster oil return chamber 303, and a pressure building chamber 304 inside.

[0040] The oil supply device 1 supplies hydraulic oil to the boosting oil inlet chamber 302 and the pressure building chamber 304. The connecting circuit between the boosting oil inlet chamber 302 and the pressure building chamber 304 is equipped with a first check valve 5. The pressure building chamber 304 is connected to the rodless chamber of the mold locking cylinder 4. The oil inlet circuit of the pressure building chamber 304 is equipped with a pressure sensor 6. The boosting oil return chamber 303 is connected to the oil tank 2. The oil return circuit between the boosting oil return chamber 303 and the oil tank 2 is equipped with a first reversing valve 7. The first reversing valve 7 is electrically connected to the pressure sensor 6.

[0041] When the pressure sensor 6 detects that the pressure in the pressure chamber 304 reaches the first pressure threshold, the first directional valve 7 is energized to control the hydraulic oil in the booster return oil chamber 303 to flow into the oil tank 2, so that the pressure in the booster inlet oil chamber 302 is greater than the pressure in the booster return oil chamber 303, thereby causing the booster piston rod 301 to press the hydraulic oil in the pressure chamber 304 into the rodless chamber of the mold locking cylinder 4.

[0042] In this embodiment, the mold-locking cylinder 4 may include a plurality of double-acting cylinders 401 and a plurality of single-acting cylinders 402, and the plurality of double-acting cylinders 401 and the plurality of single-acting cylinders 402 may be configured as follows: Figure 5 The cylinders are arranged circumferentially. The rodless cavity of the mold-locking cylinder 4 can refer to the rodless cavity of the double-acting cylinder 401 and the rodless cavity of the single-acting cylinder 402.

[0043] The booster cylinder 3 comprises a first cylinder body and a second cylinder body with sequentially decreasing cross-sectional areas. The booster piston rod 301 of the booster cylinder 3 comprises a first piston section and a second piston section with sequentially decreasing cross-sectional areas. The first piston section is slidably fitted to the first cylinder body, and the second piston section is slidably fitted to the second cylinder body. A booster oil inlet chamber 302 is formed between the outer end of the first piston section and the first cylinder body. A booster oil return chamber 303 is formed between the inner end of the first piston section, the second piston section, and the first cylinder body. A pressure-building chamber 304 is formed between the second piston section and the second cylinder body. In the initial state, a certain amount of hydraulic oil is stored in the booster oil return chamber 303.

[0044] The oil supply device 1 can be an oil pump; the connecting circuit between the booster oil inlet chamber 302 and the pressure building chamber 304 is provided with a connection node 9, which is connected to the oil supply device 1. The connecting circuit between the connection node 9 and the pressure building chamber 304 of the booster cylinder 3 is provided with a first check valve 5. The first check valve 5 allows hydraulic oil to flow from the connection node 9 to the pressure building chamber 304, and the first check valve 5 is used to prevent hydraulic oil from flowing in the reverse direction from the pressure building chamber 304 to the connection node 9.

[0045] The first directional valve 7 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, and then controlling the on / off and flow direction of hydraulic oil by changing the position of the valve core.

[0046] Based on the above settings, the specific working process of this mold-locking pressurization hydraulic circuit is as follows:

[0047] In the initial state, such as Figure 1 As shown, the first reversing valve 7 is in the closed state, and the booster piston rod 301 is in the retracted state; when the mold-locking operation begins, as... Figure 2 As shown, the oil supply device 1 supplies hydraulic oil to the boosting oil inlet chamber 302 and the pressure building chamber 304. The hydraulic oil supplied to the boosting oil inlet chamber 302 can push the boosting piston rod 301 to move to a certain extent, and the hydraulic oil supplied to the pressure building chamber 304 will flow into the rodless chamber of the mold clamping cylinder 4 to generate a certain mold clamping force. As the oil supply operation continues, since the hydraulic oil in the pressure building chamber 304 cannot be discharged to the oil tank 2 through the first reversing valve 7, the pressure in the boosting oil inlet chamber 302 and the pressure in the pressure building chamber 304 will gradually reach a state of equilibrium. At this time, the boosting piston rod 301 no longer moves, and the pressure in the pressure building chamber 304 (specifically, the pressure in the connecting circuit between the pressure building chamber 304 and the rodless chamber of the mold clamping cylinder 4) will gradually rise. When the pressure sensor 6 detects that the pressure in the pressure building chamber 304 reaches the first pressure threshold, such as Figure 3 As shown, the pressure sensor 6 outputs a corresponding electrical signal to the first directional valve 7, energizing and opening the first directional valve 7. At this time, the hydraulic oil in the boosted return oil chamber 303 will be discharged to the oil tank 2 through the first directional valve 7, making the pressure in the boosted inlet oil chamber 302 greater than the pressure in the boosted return oil chamber 303. Under the action of this pressure difference, the boosted piston rod 301 will be pushed to further compress the pressure building chamber 304, thereby further pressurizing the hydraulic oil in the pressure building chamber 304 into the rodless chamber of the mold locking cylinder 4, further increasing the pressure in the rodless chamber of the mold locking cylinder 4, and further increasing the mold locking force generated by the piston rod of the mold locking cylinder 4. In this way, the mold locking pressure of the mold locking cylinder 4 is realized.

[0048] During the above-mentioned mold-locking pressurization process, the first one-way valve 5 ensures that hydraulic oil is normally supplied to the pressure-building chamber 304, while preventing the hydraulic oil in the pressure-building chamber 304 and the rodless chamber of the mold-locking cylinder 4 from flowing back to the oil supply device 1, thereby ensuring that the pressure in the rodless chamber of the mold-locking cylinder 4 can be stably increased.

[0049] Therefore, the clamping pressurization hydraulic circuit provided in this embodiment connects the pressurization cylinder 3 and the clamping cylinder 4 in series, and simultaneously supplies hydraulic oil to both the pressurization cylinder 3 and the clamping cylinder 4. When the clamping pressure reaches a certain level, the hydraulic oil in the pressurization return chamber 303 of the pressurization cylinder 3 is discharged, creating a pressure difference between the pressurization return chamber 303 and the pressurization inlet chamber 302 of the pressurization cylinder 3. This pressure difference is used to further pressurize the hydraulic oil in the pressure building chamber 304 of the pressurization cylinder 3 into the clamping cylinder 4, thereby further increasing the clamping force generated by the clamping cylinder 4. This solution achieves clamping pressurization without the need for an accumulator, that is, it increases the clamping pressure of the clamping cylinder 4 by using the pressurization cylinder 3 without using a large-diameter clamping cylinder 4 or increasing the system complexity and space requirements, thereby reducing the manufacturing and maintenance costs of the clamping cylinder 4 and the die-casting machine.

[0050] In one embodiment, refer to Figures 1 to 4 The mold-locking pressurizing hydraulic circuit also includes a second reversing valve 8. The oil supply device 1 is connected to the pressurizing oil inlet chamber 302 and the pressurizing oil return chamber 303 through the second reversing valve 8. The pressure sensor 6 is electrically connected to the second reversing valve 8.

[0051] When the pressure sensor 6 detects that the pressure in the pressure building chamber 304 reaches the second pressure threshold, the first reversing valve 7 is de-energized to prevent the hydraulic oil in the boosting return chamber 303 from flowing back to the oil tank 2, and the second reversing valve 8 is de-energized to prevent the oil supply device 1 from supplying hydraulic oil to the boosting inlet chamber 302 and the pressure building chamber 304; the second pressure threshold is greater than the first pressure threshold.

[0052] Specifically, the second 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, thereby changing the position of the valve core in the valve body by energizing or de-energizing the electromagnet, and then controlling the on / off and flow direction of the hydraulic oil by changing the position of the valve core.

[0053] The second pressure threshold can refer to the pressure that the pressure chamber 304 should have when the clamping force generated by the clamping cylinder 4 reaches the preset clamping requirements.

[0054] In the initial state, such as Figure 1 As shown, the second reversing valve 8 is in the closed state; when the mold-locking operation begins, as... Figure 2As shown, the second directional valve 8 is energized and opened, allowing hydraulic oil from the oil supply device 1 to be supplied into the booster oil inlet chamber 302 and the pressure building chamber 304 through the second directional valve 8. During the subsequent pressurization process, when the pressure sensor 6 detects that the pressure in the pressure building chamber 304 has risen to the second pressure threshold, it indicates that the clamping force generated by the clamping cylinder 4 has reached the preset clamping requirement, such as... Figure 4 As shown, at this time, the pressure sensor 6 outputs corresponding electrical signals to the first reversing valve 7 and the second reversing valve 8, triggering the first reversing valve 7 and the second reversing valve 8 to de-energize and close, thereby blocking the return oil circuit between the booster return oil chamber 303 and the oil tank 2, and preventing the oil supply device 1 from continuing to supply oil to the booster inlet oil chamber 302 and the pressure building chamber 304. In this way, the pressure building chamber 304 and the rodless chamber of the mold locking cylinder 4 can be maintained at the current pressure state, so that the mold locking cylinder 4 enters the pressure holding state, and the subsequent die casting operation can be performed under the preset mold locking pressure.

[0055] In one embodiment, refer to Figures 1 to 4 The second directional valve 8 is configured as a solenoid directional valve. The second directional valve 8 includes a first oil inlet P1, a first oil outlet T1, a first working oil port A1, and a second working oil port B1. The first oil inlet P1 is connected to the oil supply device 1, the first oil outlet T1 is connected to the oil tank 2, the first working oil port A1 is connected to the booster return oil chamber 303, and the second working oil port B1 is connected to the booster inlet oil chamber 302 and the pressure building chamber 304.

[0056] In one embodiment, refer to Figures 1 to 4 The first directional valve 7 is configured as a solenoid directional valve. The first directional valve 7 includes a third working port A2 and a fourth working port B2. The third working port A2 is connected to the first working port A1, and the fourth working port B2 is connected to the booster return oil chamber 303.

[0057] Based on the above settings, in the initial state, such as Figure 1 As shown, the valve core of the second reversing valve 8 is in the first working position. At this time, both the first working port A1 and the second working port B1 are connected to the first oil outlet T1, and the first oil inlet P1 is closed. The valve core of the first reversing valve 7 is in the first working position. At this time, the flow from the third working port A2 to the fourth working port B2 is unidirectional. When the mold locking operation begins, as shown... Figure 2 As shown, when the solenoid coil a of the second directional valve 8 is energized, the valve core of the second directional valve 8 is switched to the second working position. At this time, the first oil inlet P1 is connected to the second working oil port B1, and the first oil outlet T1 is connected to the first working oil port A1. The hydraulic oil of the oil supply device 1 can be supplied to the booster oil inlet chamber 302 and the pressure building chamber 304 in sequence through the first oil inlet P1 and the second working oil port B1. When the pressure sensor 6 detects that the pressure in the pressure building chamber 304 rises to the first pressure threshold, as... Figure 3As shown, the pressure sensor 6 outputs a corresponding electrical signal to the first directional valve 7, triggering the solenoid coil of the first directional valve 7 to be energized, causing the valve core of the first directional valve 7 to switch to the second working position. At this time, there is bidirectional communication between the third working port A2 and the fourth working port B2. Since the pressure of the booster return oil chamber 303 is greater than the pressure of the oil tank 2, the hydraulic oil in the booster return oil chamber 303 can flow back to the oil tank 2 through the fourth working port B2 and the third working port A2 in sequence, so that the booster piston rod 301 further presses the hydraulic oil into the rodless chamber of the mold locking cylinder 4 under the pressure difference, thereby boosting the pressure of the mold locking cylinder 4; when the pressure sensor 6 detects that the pressure of the pressure building chamber 304 rises to the second pressure threshold, as Figure 4 As shown, pressure sensor 6 outputs a corresponding electrical signal to the first directional valve 7, triggering the solenoid coil of the first directional valve 7 to de-energize, causing the valve core of the first directional valve 7 to reset to the first working position under the action of the reset spring. At this time, the third working port A2 to the fourth working port B2 are unidirectionally connected, blocking the hydraulic oil from flowing back to the oil tank 2. At the same time, pressure sensor 6 outputs a corresponding electrical signal to the second directional valve 8, triggering the solenoid coil a of the second directional valve 8 to de-energize, causing the valve core of the second directional valve 8 to reset to the first working position under the action of the reset spring. At this time, the first working port A1 and the second working port B1 are connected to the first oil outlet T1, and the first oil inlet P1 is cut off, blocking the oil supply device 1 from continuing to supply hydraulic oil to the pressurized oil inlet chamber 302 and the pressure building chamber 304. At this time, the pressure building chamber 304 and the rodless chamber of the mold locking cylinder 4 are maintained at the current pressure state, so that the mold locking cylinder 4 enters the pressure holding state, thereby allowing subsequent die casting operations to be performed under the preset mold locking pressure.

[0058] In one embodiment, refer to Figures 1 to 4 A connection node 9 is provided on the connecting circuit between the boosting oil inlet chamber 302 and the pressure building chamber 304; the mold locking boosting hydraulic circuit also includes a second check valve 10, which is configured as a hydraulically controlled check valve. The second check valve 10 is located between the connection node 9 and the oil supply device 1, and the control port X of the second check valve 10 is connected to the first working port A1.

[0059] Specifically, when hydraulic oil is not supplied to the control port X of the second check valve 10, the second check valve 10 is in a one-way open state, allowing hydraulic oil to flow from the oil supply device 1 to the booster oil inlet chamber 302 and the pressure building chamber 304 in the forward direction; when hydraulic oil is supplied to the control port X of the second check valve 10, the second check valve 10 is in a two-way open state, and the hydraulic oil at both ends of the second check valve 10 can flow in both directions based on the pressure relationship.

[0060] By setting the second check valve 10, when the mold-locking cylinder 4 enters the pressure-holding state, the first working port A1 and the second working port B1 of the second directional valve 8 are both connected to the first outlet port T1. At this time, the second check valve 10 can prevent the hydraulic oil in the boosting oil inlet chamber 302 and the pressure building chamber 304 from flowing back to the oil tank 2 through the second working port B1, and can ensure that the pressure of the boosting oil inlet chamber 302 and the pressure building chamber 304 is stably maintained at the current state. In addition, after the die-casting operation is completed, the booster cylinder 3 and the mold-locking cylinder 4 need to be reset. At this time, the electromagnetic coil b of the second reversing valve 8 can be energized, which will drive the valve core of the second reversing valve 8 to switch to the third working position, so that the first oil inlet P1 is connected to the first working oil port A1 and the first oil outlet T1 is connected to the second working oil port B1. Then, the oil supply device 1 can be used to replenish hydraulic oil to the booster return oil chamber 303 through the first oil inlet P1 and the first working oil port A1 in sequence. The hydraulic oil of the first working oil port A1 will also be supplied to the control oil port X of the second check valve 10 at the same time, so that the second check valve 10 enters the bidirectional conduction state, thereby allowing the hydraulic oil of the booster inlet oil chamber 302 and the pressure building chamber 304 to flow back to the oil tank 2 through the second check valve 10, the second working oil port B1 and the first oil outlet T1 in sequence. This will drive the booster piston rod 301 to move in the opposite direction of the boosting direction, thereby realizing the reset of the booster cylinder 3 and the mold-locking cylinder 4.

[0061] In one embodiment, refer to Figures 1 to 4 The mold-locking pressurization hydraulic circuit also includes a position sensor 11, which is connected to the pressurization piston rod 301. The position sensor 11 is used to obtain the real-time position of the pressurization piston rod 301.

[0062] By monitoring the position sensor 11, the operator can keep track of the working status of the booster cylinder 3 in real time by the current position of the booster piston rod 301, thereby enabling more precise control of the booster molding process.

[0063] This utility model embodiment also provides a die-casting machine, please refer to [link / reference]. Figures 1 to 5 The die-casting machine includes the mold-locking pressurizing hydraulic circuit in any of the above embodiments.

[0064] In this embodiment, the die-casting machine specifically refers to a two-plate die-casting machine. The die-casting machine includes a fixed platen (not shown in the figure) and a movable platen 12. The fixed platen is provided with a fixed mold (not shown in the figure) and a guide post (not shown in the figure). The movable platen 12 is slidably fitted onto the guide post along the length direction of the guide post. A movable mold (not shown in the figure) is provided on the side of the movable platen 12 facing the fixed platen. The movable platen 12 can move in the direction close to the fixed platen under the drive of the mold-moving cylinder, so that the movable mold and the fixed mold fit together.

[0065] The mold-locking cylinder 4 includes a double-acting cylinder 401 and a single-acting cylinder 402. Both the rod-side and rodless-side chambers of the double-acting cylinder 401 can be supplied with hydraulic oil, using the pressure of the hydraulic oil to drive the piston rod of the double-acting cylinder 401 to extend or retract. The cylinder body of the double-acting cylinder 401 is connected to the side of the moving mold plate 12 facing away from the fixed mold plate, and the piston rod of the double-acting cylinder 401 is connected to the fixed plate 13. The single-acting cylinder 402 can only be supplied with hydraulic oil in its rodless-side chamber, using the pressure of the hydraulic oil to drive the piston rod of the single-acting cylinder 402 to extend; the retraction of the piston rod of the single-acting cylinder 402 requires the assistance of spring force, gravity, or other external forces. The cylinder body of the single-acting cylinder 402 is connected to the side of the moving mold plate 12 facing away from the fixed mold plate, and the piston rod of the single-acting cylinder 402 is connected to the fixed plate 13. The rodless cavity of the mold-locking cylinder 4 can refer to the rodless cavity of the double-acting cylinder 401 and the rodless cavity of the single-acting cylinder 402.

[0066] Both the double-acting hydraulic cylinder 401 and the single-acting hydraulic cylinder 402 can be configured as one or more; when both the double-acting hydraulic cylinder 401 and the single-acting hydraulic cylinder 402 are configured as multiple, the multiple double-acting hydraulic cylinders 401 and the multiple single-acting hydraulic cylinders 402 can be configured as follows: Figure 5 The guide post is arranged circumferentially as shown, but this is not limited to this.

[0067] A brake mechanism can be installed on the fixed plate 13. The brake mechanism can engage with the guide post to fix the fixed plate 13 to the guide post. When the piston rods of the double-acting cylinder 401 and the single-acting cylinder 402 extend, since the fixed plate 13 is in a fixed state, it will drive the cylinder bodies of the double-acting cylinder 401 and the single-acting cylinder 402 to move away from the fixed plate 13. Thus, the cylinder bodies of the double-acting cylinder 401 and the single-acting cylinder 402 apply force to the moving template 12, so that the moving mold on the moving template 12 is tightly pressed with the fixed mold on the fixed template, thereby realizing the mold locking operation.

[0068] For other specific structures of the mold-locking pressurization hydraulic circuit, please refer to the above embodiments. Since this die-casting machine adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments. That is, the booster cylinder 3 and the clamping cylinder 4 are connected in series, and hydraulic oil is supplied to the booster cylinder 3 and the clamping cylinder 4 at the same time. When the clamping pressure reaches a certain level, the hydraulic oil in the booster return oil chamber 303 of the booster cylinder 3 is discharged, so that a pressure difference is formed between the booster return oil chamber 303 and the booster inlet oil chamber 302 of the booster cylinder 3. The hydraulic oil in the pressure building chamber 304 of the booster cylinder 3 is further pressed into the clamping cylinder 4 by the pressure difference, so that the clamping force generated by the clamping cylinder 4 is further increased. This solution achieves clamping pressure boosting without setting an accumulator. That is, the clamping pressure of the clamping cylinder 4 is increased by the booster cylinder 3 without using a large-diameter clamping cylinder 4 and without increasing the system complexity and space requirements, thereby reducing the manufacturing and maintenance costs of the clamping cylinder 4 and the die-casting machine.

[0069] It should be noted that the other contents of the mold-locking pressure boosting hydraulic circuit and die-casting machine disclosed in this utility model can be found in the prior art, and will not be repeated here.

[0070] 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 mold-locking pressure boosting hydraulic circuit for a die-casting machine, characterized in that, This includes an oil supply device, an oil tank, a booster cylinder, and a mold-locking cylinder; among which, The booster cylinder is divided into two sections, a large section and a small section, and is equipped with a booster piston rod inside. The booster piston rod is divided into two sections, a large section and a small section. The large section of the booster piston rod is slidably disposed inside the large section of the booster cylinder, and the small section of the booster piston rod is slidably disposed inside the small section of the booster cylinder, so that the booster cylinder forms a booster oil inlet chamber, a booster oil return chamber and a pressure building chamber. The oil supply device supplies hydraulic oil to the boosting oil inlet chamber and the pressure building chamber. A first check valve is provided in the connecting circuit between the boosting oil inlet chamber and the pressure building chamber. The pressure building chamber is connected to the rodless chamber of the mold locking cylinder. A pressure sensor is provided in the oil inlet circuit of the pressure building chamber. The boosting oil return chamber is connected to the oil tank. A first reversing valve is provided in the oil return circuit between the boosting oil return chamber and the oil tank. The first reversing valve is electrically connected to the pressure sensor. When the pressure sensor detects that the pressure in the pressure-building chamber reaches the first pressure threshold, the first directional valve is energized to control the hydraulic oil in the booster return chamber to flow into the oil tank, so that the pressure in the booster inlet chamber is greater than the pressure in the booster return chamber, thereby causing the booster piston rod to press the hydraulic oil in the pressure-building chamber into the rodless chamber of the mold-locking cylinder.

2. The mold-locking pressurization hydraulic circuit as described in claim 1, characterized in that, The mold-locking pressurizing hydraulic circuit also includes a second reversing valve. The oil supply device is connected to the pressurizing oil inlet chamber and the pressurizing oil return chamber through the second reversing valve. The pressure sensor is electrically connected to the second reversing valve. When the pressure sensor detects that the pressure in the pressure-building chamber reaches the second pressure threshold, the first directional valve is de-energized to prevent the hydraulic oil in the booster return chamber from flowing back to the oil tank, and the second directional valve is de-energized to prevent the oil supply device from supplying hydraulic oil to the booster inlet chamber and the pressure-building chamber; the second pressure threshold is greater than the first pressure threshold.

3. The mold-locking pressurizing hydraulic circuit as described in claim 2, characterized in that, The second reversing valve is configured as a solenoid reversing valve. The second reversing valve includes a first oil inlet, a first oil outlet, a first working oil port, and a second working oil port. The first oil inlet is connected to the oil supply device, the first oil outlet is connected to the oil tank, the first working oil port is connected to the booster return oil chamber, and the second working oil port is connected to the booster inlet oil chamber and the pressure building chamber.

4. The mold-locking pressurization hydraulic circuit as described in claim 3, characterized in that, The first reversing valve is configured as a solenoid reversing valve. The first reversing valve includes a third working oil port and a fourth working oil port. The third working oil port is connected to the first working oil port, and the fourth working oil port is connected to the pressurized return oil chamber.

5. The mold-locking pressurization hydraulic circuit as described in claim 4, characterized in that, A connection node is provided on the connecting circuit between the boosting oil inlet chamber and the pressure building chamber; the mold locking boosting hydraulic circuit also includes a second check valve, which is configured as a hydraulically controlled check valve. The second check valve is located between the connection node and the oil supply device, and the control port of the second check valve is connected to the first working port.

6. The mold-locking pressurizing hydraulic circuit as described in claim 1, characterized in that, The first reversing valve is configured as a solenoid reversing valve. The first reversing valve includes a third working oil port and a fourth working oil port. The third working oil port is connected to the oil tank, and the fourth working oil port is connected to the pressurized return oil chamber.

7. The mold-locking pressurization hydraulic circuit as described in claim 1, characterized in that, A connection node is provided on the oil line connecting the booster oil inlet chamber and the pressure building chamber; the mold locking booster hydraulic circuit also includes a second check valve, which is located between the connection node and the oil supply device.

8. The mold-locking pressurization hydraulic circuit as described in any one of claims 1 to 7, characterized in that, The mold-locking pressurizing hydraulic circuit also includes a position sensor, which is connected to the pressurizing piston rod and is used to obtain the real-time position of the pressurizing piston rod.

9. The mold-locking pressurization hydraulic circuit as described in any one of claims 1 to 7, characterized in that, The mold-locking cylinder includes several double-acting cylinders and several single-acting cylinders.

10. A die-casting machine, characterized in that, The die-casting machine includes a mold-locking and pressurizing hydraulic circuit as described in any one of claims 1 to 9.

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