Injection pressurization control loop of ultra-large die casting machine

Abstract

The utility model discloses an ultra-large die-casting machine injection supercharging control loop, which relates to the technical field of die-casting machines, and comprises a gas-liquid supercharger and an injection oil cylinder, the gas-liquid supercharger is provided with a first annular cavity and a first rodless cavity, the injection oil cylinder is provided with a second annular cavity and a second rodless cavity, the first rodless cavity is connected with a supercharging tank through a first branch, and the second rodless cavity is connected with a second branch. The first annular cavity is connected with an energy storage valve through a second branch, the first annular cavity is connected with a second rodless cavity through a third branch, the third branch is provided with a pressurization inlet switch valve, the side edge, away from the energy storage valve, of the second branch is sequentially provided with a first one-way valve and a first bypass, the first bypass is connected with a servo valve, and the servo valve is connected with the second annular cavity through a fourth branch; and a pressurizing outlet switch valve is arranged on the first bypass. The injection pressurization control loop of the ultra-large die casting machine is small in energy loss and capable of achieving double-closed-loop control.

Description

Technical Field

[0001] The utility model belongs to the technical field of die-casting machines, and in particular relates to an injection pressure boosting control circuit for a super-large die-casting machine. Background Art

[0002] With the development of automobile integrated molding technology, the ultra-large die-casting industry is booming. At the same time, the technical innovation issues that follow are that the integration of castings is getting bigger and bigger, which puts higher and higher performance requirements on die-casting machines. The key is the increase stage in the casting generation process, which ensures the compact internal structure of the die-casting, reduces structural defects, and improves the quality of the casting.

[0003] The traditional injection boost control circuit mainly relies on the boost accumulator to guide the hydraulic oil into the boost cylinder, and the boost cylinder applies pressure to the injection cylinder. In this process, there will be energy loss and the response time is long. In addition, the sensor for detecting the boost pressure of the injection cylinder is generally set in the oil circuit. The pressure value detected by the traditional control oil circuit pressure sensor is the boost cylinder pressure, not the injection end pressure, which will cause errors. At the same time, the pressure and speed in the traditional boost oil circuit are controlled by separate valves.

[0004] Prior art such as the invention patent named "Injection Liquid Pressure Circuit of Supercharged Die Casting Machine", the publication number of this invention patent is JP59035871A. The purpose of this invention is to make the electromagnetically operated selection valve self-closed at the same time when the pump of the hydraulic source stops running, and to perform speed change and supercharge operation in a short time. The structure of this invention: when the filling of molten metal is completed by the injection plunger, when the pressure in the pressure chamber increases to the pressure of the reservoir and the pilot-operated check valve for rapid closing is quickly closed by the internal pressure, the single-acting piston is prevented from moving forward and enters the pressurization stage. Here, the solenoid-operated selection valve and the solenoid-operated selection valve are energized at the same time; the sequence valve is opened and the pilot-operated check valve B for rapid opening is opened, and then the pressure oil in the accumulator acts on the pressure chamber of the supercharger cylinder, thereby completing the supercharger operation. The molten metal solidifies after a specified time. When the solenoid valve is energized at this time point, the pilot check valve opens, and the pressure oil passes through the quickly opened pilot check valve A, and then flows into the pressure chamber of the single-acting cylinder through the valve, so that the piston moves forward and pushes out the solidified metal. However, this invention cannot achieve double closed-loop control and has a large energy loss. Summary of the invention

[0005] The utility model aims to provide an injection boost control circuit for a super large die casting machine which has small energy loss and realizes double closed loop control.

[0006] The technical solution adopted by the utility model to achieve the above-mentioned purpose is:

[0007] A super-large die-casting machine injection boost control circuit includes a gas-liquid booster and an injection oil cylinder, the gas-liquid booster has a first annular cavity and a first rodless cavity, the injection oil cylinder has a second annular cavity and a second rodless cavity, the first rodless cavity is connected to a boost tank through a first branch, the first annular cavity is connected to an energy storage valve through a second branch, the first annular cavity is connected to the second rodless cavity through a third branch, a boost inlet switch valve is provided on the third branch, a first check valve and a first bypass are provided in sequence along the side of the second branch away from the energy storage valve, the first bypass is connected to a servo valve, the servo valve is connected to the second annular cavity through a fourth branch, and a boost outlet switch valve is provided on the first bypass.

[0008] According to an embodiment of the utility model, the accumulator valve is connected to the system pressure oil through a ninth branch.

[0009] Before injection, the pressurization and energy storage action needs to be completed. The system pressure oil flows into the first annular cavity of the gas-liquid booster through the energy storage valve. The piston of the gas-liquid booster moves upward to compress the gas in the first rodless cavity, so that the gas in the first rodless cavity of the gas-liquid booster is compressed and stores energy.

[0010] After the injection is completed, the boosting stage begins, the boosting inlet switch valve is opened, and the boosting gas in the boosting tank is filled into the first rodless chamber in the gas-liquid booster, pushing the piston rod of the gas-liquid booster downward, and the hydraulic oil flows into the rodless chamber of the injection cylinder through the boosting inlet switch valve to achieve boosting. When the boosting outlet switch valve is opened, the hydraulic oil in the first annular chamber of the gas-liquid booster can also flow into the second annular chamber of the injection cylinder through the boosting outlet switch valve. At this time, the servo valve can be used to control the pressure of the hydraulic oil flowing into the second annular chamber of the injection cylinder through the boosting outlet switch valve, and the servo valve itself can control the injection speed of the injection cylinder, thereby realizing that one servo valve can control both the pressure and speed of the injection cylinder, and realize double closed-loop control.

[0011] Through the design of an injection boost control circuit for an ultra-large die-casting machine, compared with the traditional injection boost control circuit, the boost accumulator and the boost cylinder are eliminated, and a gas-liquid booster is added, so that the gas-liquid booster acts directly on the injection cylinder, which greatly reduces the energy loss of the hydraulic oil in the circuit and shortens the boost response time; secondly, it also ensures that the boost servo valve can directly control the pressure of the injection cylinder; at the same time, a boost outlet switch valve is added to be connected to the servo valve, which ensures that one servo valve can control both the pressure and speed of the injection cylinder, thereby realizing double closed-loop control.

[0012] It should be noted that the first one-way valve is used in the boosting and energy storage stage. When the hydraulic oil flows from the ninth branch through the accumulator and the first one-way valve into the first annular cavity of the gas-liquid booster to complete the boosting and energy storage action, the first one-way valve plays the role of connecting the oil circuit; in the boosting stage, the hydraulic oil in the first annular cavity of the gas-liquid booster cannot flow out through the first one-way valve, and the first one-way valve plays the role of blocking the oil circuit.

[0013] Furthermore, the booster tank is a nitrogen cylinder. Furthermore, two nitrogen cylinders are symmetrically provided.

[0014] According to an embodiment of the present utility model, a first pressure sensor is provided on the first branch line.

[0015] Through the above design, the first pressure sensor on the first branch can detect the pressure value in the gas-liquid booster.

[0016] According to an embodiment of the utility model, the second rodless chamber is connected to the fast accumulator through the fifth branch.

[0017] It should be noted that the fast accumulator can realize the fast energy storage of the die-casting machine before fast injection, which is similar to the pressurized energy storage process. In the fast injection stage, the hydraulic oil flows from the third one-way valve into the second rodless chamber of the injection cylinder to push the piston to move quickly, thereby achieving the purpose of fast injection.

[0018] According to an embodiment of the utility model, a second pressure sensor and a third one-way valve are sequentially provided along the fifth branch away from the second rodless chamber.

[0019] It should be noted that the third one-way valve is used as a fast accumulator outlet valve and can also prevent the hydraulic oil in the second rodless chamber of the injection cylinder from flowing back during the pressurization stage. The second pressure sensor is used to measure the pressure in the second rodless chamber of the injection cylinder during fast injection.

[0020] According to an embodiment of the utility model, the first annular chamber is connected to a relief valve via a second bypass.

[0021] Through the above design, the overflow valve can be used as a safety valve to adjust the pressure in the gas-liquid booster to ensure that the required pressure is reached.

[0022] According to an embodiment of the utility model, the second bypass is provided with a third bypass connected to the first unloading valve, the first unloading valve is connected to the second unloading valve through the sixth branch, and the second unloading valve is connected to the second branch through the seventh branch.

[0023] According to an embodiment of the utility model, the overflow valve is connected to the sixth branch through the eighth branch.

[0024] Through the above design, it can be realized that during the later maintenance process, if there is high pressure in the gas-liquid booster, there will be a safety hazard. Before maintenance, the residual pressure in the gas-liquid booster can be released through the first unloading valve and the second unloading valve to eliminate the safety hazard.

[0025] According to an embodiment of the utility model, a third pressure sensor and a second one-way valve are sequentially provided on the seventh branch away from the second unloading valve.

[0026] It should be noted that in the boosting and energy storage stage, the piston rod of the gas-liquid booster moves upward, which causes the annular cavity of the gas-liquid booster to be in a vacuum state. In the vacuum state, the annular cavity of the gas-liquid booster can be supplemented with hydraulic oil through the second one-way valve. The third pressure sensor is used to measure the pressure of the annular cavity of the gas-liquid booster. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of an injection pressure boost control circuit for a super-large die-casting machine;

[0028] Figure numbers: gas-liquid booster 1, injection cylinder 2, first annular cavity 3, first rodless cavity 4, second annular cavity 5, second rodless cavity 6, first branch 7, boosting tank 8, second branch 9, accumulator valve 10, third branch 11, boosting inlet switch valve 12, first one-way valve 13, first bypass 14, servo valve 15, fourth branch 16, boosting outlet switch valve 17, first pressure sensor 18, fifth branch 19, fast accumulator 20, second pressure sensor 21, third one-way valve 22, second bypass 23, overflow valve 24, third bypass 25, first unloading valve 26, sixth branch 27, second unloading valve 28, seventh branch 29, third pressure sensor 30, second one-way valve 31, eighth branch 32, ninth branch 33, system pressure oil 34. DETAILED DESCRIPTION

[0029] The technical solution of the utility model is further described in detail below in conjunction with specific implementation methods and drawings:

[0030] Embodiment 1:

[0031] like Figure 1 As shown, a super-large die-casting machine injection boost control circuit includes a gas-liquid booster 1 and an injection cylinder 2, the gas-liquid booster 1 has a first annular cavity 3 and a first rodless cavity 4, the injection cylinder 2 has a second annular cavity 5 and a second rodless cavity 6, the first rodless cavity 4 is connected to a boost tank 8 through a first branch 7, the first annular cavity 3 is connected to an energy storage valve 10 through a second branch 9, the first annular cavity 3 is connected to the second rodless cavity 6 through a third branch 11, a boost inlet switch valve 12 is provided on the third branch 11, a first check valve 13 and a first bypass 14 are provided in sequence along the side of the second branch 9 away from the energy storage valve 10, the first bypass 14 is connected to a servo valve 15, the servo valve 15 is connected to the second annular cavity 5 through a fourth branch 16, and a boost outlet switch valve 17 is provided on the first bypass 14.

[0032] The accumulator valve 10 is connected to the system pressure oil 34 via a ninth branch 33 .

[0033] Before injection, the pressurization and energy storage action needs to be completed. The system pressure oil 34 flows into the first annular cavity 3 of the gas-liquid booster 1 through the energy storage valve 10. The piston of the gas-liquid booster 1 moves upward to compress the gas in the first rodless cavity 4, so that the gas in the first rodless cavity 4 of the gas-liquid booster 1 is compressed to store energy.

[0034] After the injection is finished, the pressurization stage begins, the pressurization inlet switch valve 12 is opened, and the pressurized gas in the pressurization tank 8 is filled into the first rodless chamber 4 in the gas-liquid supercharger 1, pushing the piston rod of the gas-liquid supercharger 1 downward, and the hydraulic oil flows into the rodless chamber of the injection oil cylinder 2 through the pressurization inlet switch valve 12 to achieve pressurization. When the pressurization outlet switch valve 17 is opened, the hydraulic oil in the first annular chamber 3 of the gas-liquid supercharger 1 can also flow into the second annular chamber 5 of the injection oil cylinder 2 through the pressurization outlet switch valve 17. At this time, the pressure of the hydraulic oil flowing into the second annular chamber 5 of the injection oil cylinder 2 through the pressurization outlet switch valve 17 can be controlled by the servo valve 15, and the servo valve 15 itself can control the injection speed of the injection oil cylinder 2, thereby realizing that one servo valve 15 can control both the pressure and the speed of the injection oil cylinder 2, and realize double closed-loop control.

[0035] Through the design of an injection boost control circuit of an ultra-large die-casting machine, compared with the traditional injection boost control circuit, the boost accumulator and the boost cylinder are cancelled, and a gas-liquid booster 1 is added, so that the gas-liquid booster 1 acts directly on the injection cylinder 2, which greatly reduces the energy loss of the hydraulic oil in the circuit and shortens the boost response time; secondly, it also ensures that the boost servo valve 15 can directly control the pressure of the injection cylinder 2; at the same time, a boost outlet switch valve 17 is added and connected to the servo valve 15, which ensures that one servo valve 15 can control both the pressure and the speed of the injection cylinder 2, thereby realizing double closed-loop control.

[0036] It should be noted that the first one-way valve 13 is used in the boosting and energy storage stage. When the hydraulic oil flows from the ninth branch 33 through the accumulator and the first one-way valve 13 into the first annular cavity 3 of the gas-liquid booster 1 to complete the boosting and energy storage action, the first one-way valve 13 plays a role in connecting the oil circuit; in the boosting stage, the hydraulic oil in the first annular cavity 3 of the gas-liquid booster 1 cannot flow out through the first one-way valve 13, and the first one-way valve 13 plays a role in blocking the oil circuit.

[0037] Furthermore, the boost tank 8 is a nitrogen gas cylinder. Furthermore, two nitrogen gas cylinders are symmetrically provided.

[0038] A first pressure sensor 18 is provided on the first branch 7 .

[0039] Through the above design, the first pressure sensor 18 on the first branch 7 can detect the pressure value in the gas-liquid booster 1 .

[0040] The second rodless chamber 6 is connected to the fast energy accumulator 20 via the fifth branch 19 .

[0041] It should be noted that the fast accumulator 20 can enable the die-casting machine to complete fast energy storage before fast injection, similar to the pressurized energy storage process. In the fast injection stage, the hydraulic oil flows from the third one-way valve 22 into the second rodless chamber 6 of the injection cylinder 2 to push the piston to move quickly, thereby achieving the purpose of fast injection.

[0042] A second pressure sensor 21 and a third one-way valve 22 are sequentially provided along the fifth branch 19 away from the second rodless chamber 6 .

[0043] It should be noted that the third one-way valve 22 is used as an outlet valve of the fast accumulator 20, and can also prevent the hydraulic oil in the second rodless chamber 6 of the injection cylinder 2 from flowing back during the pressurization stage. The second pressure sensor 21 is used to measure the pressure in the second rodless chamber 6 of the injection cylinder 2 during fast injection.

[0044] The first annular chamber 3 is connected to an overflow valve 24 via a second bypass 23 .

[0045] Through the above design, the overflow valve 24 can be used as a safety valve to adjust the pressure in the gas-liquid booster 1 to ensure that the required pressure is reached.

[0046] The second bypass 23 is bypassed by a third bypass 25 connected to a first unloading valve 26 . The first unloading valve 26 is connected to a second unloading valve 28 via a sixth branch 27 . The second unloading valve 28 is connected to the second branch 9 via a seventh branch 29 . The seventh branch 29 is also connected to the third branch 11 .

[0047] The overflow valve 24 is connected to the sixth branch 27 via the eighth branch 32 .

[0048] Through the above design, it can be realized that during the later maintenance process, if there is high pressure in the gas-liquid booster 1, there will be a safety hazard. Before maintenance, the residual pressure in the gas-liquid booster 1 can be released through the first unloading valve 26 and the second unloading valve 28 to eliminate the safety hazard.

[0049] A third pressure sensor 30 and a second one-way valve 31 are sequentially provided on the seventh branch 29 away from the second unloading valve 28 .

[0050] It should be noted that, in the boosting and energy storage stage, the piston rod of the gas-liquid booster 1 moves upward, which causes the first annular chamber 3 of the gas-liquid booster 1 to be in a vacuum state. In order to prevent the vacuum state, the first annular chamber 3 of the gas-liquid booster 1 can be supplemented with hydraulic oil through the second one-way valve 31. The third pressure sensor 30 is used to measure the pressure of the first annular chamber 3 of the gas-liquid booster 1.

[0051] The embodiments described above provide a detailed description of the technical solution of the utility model. It should be understood that the above is only a specific embodiment of the utility model and is not intended to limit the utility model. Any modifications, supplements or similar substitutions made within the scope of the principles of the utility model should be included in the protection scope of the utility model.

Claims

1. An injection boost control circuit for a super large die casting machine, comprising a gas-liquid booster (1) and an injection oil cylinder (2), wherein the gas-liquid booster (1) has a first annular cavity (3) and a first rodless cavity (4), and the injection oil cylinder (2) has a second annular cavity (5) and a second rodless cavity (6), characterized in that: The first rodless chamber (4) is connected to a boost tank (8) via a first branch (7), the first annular chamber (3) is connected to an energy storage valve (10) via a second branch (9), the first annular chamber (3) is connected to the second rodless chamber (6) via a third branch (11), a boost inlet switch valve (12) is provided on the third branch (11), a first non-return valve (13) and a first bypass (14) are provided in sequence along the side of the second branch (9) away from the energy storage valve (10), the first bypass (14) is connected to a servo valve (15), the servo valve (15) is connected to the second annular chamber (5) via a fourth branch (16), and a boost outlet switch valve (17) is provided on the first bypass (14).

2. According to claim 1, a super large die casting machine injection pressure control circuit is characterized in that: A first pressure sensor (18) is provided on the first branch (7).

3. According to claim 1, the injection pressure boost control circuit of a super large die casting machine is characterized in that: The second rodless chamber (6) is connected to a fast energy accumulator (20) via a fifth branch (19).

4. According to claim 3, a super large die casting machine injection pressure control circuit is characterized in that: The fifth branch (19) is provided with a second pressure sensor (21) and a third one-way valve (22) in sequence along a path away from the second rodless chamber (6).

5. According to claim 1, the injection pressure boost control circuit of a super large die casting machine is characterized in that: The first annular chamber (3) is connected to a relief valve (24) via a second bypass (23).

6. The injection pressure boost control circuit of a super large die casting machine according to claim 5, characterized in that: The second bypass (23) is provided with a third bypass (25) connected to a first unloading valve (26); the first unloading valve (26) is connected to a second unloading valve (28) via a sixth branch (27); the second unloading valve (28) is connected to the second branch (9) via a seventh branch (29); and the seventh branch (29) is further connected to the third branch (11).

7. The injection pressure boost control circuit of a super large die casting machine according to claim 6, characterized in that: A third pressure sensor (30) and a second one-way valve (31) are sequentially provided on the seventh branch (29) away from the second unloading valve (28).

8. The injection pressure boost control circuit of a super large die casting machine according to claim 6, characterized in that: The overflow valve (24) is connected to the sixth branch (27) via the eighth branch (32).

9. The injection pressure boost control circuit of a super large die casting machine according to claim 1, characterized in that: The accumulator valve (10) is connected to the system pressure oil (34) via a ninth branch (33).

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