Die-casting machine die locking servo oil cylinder control system and method

Abstract

The invention provides a die-casting machine die locking servo oil cylinder control system and method. The die-casting machine die locking servo oil cylinder control system comprises a die locking cylinder, a power oil way and a control oil way. The power oil way comprises a flow control valve, a power oil energy accumulator, a first cartridge valve and a second cartridge valve. The control oil way comprises a first shuttle valve, a second shuttle valve, a third shuttle valve, a first electromagnetic valve, a second electromagnetic valve, a first one-way throttling valve, a second one-way throttling valve and a control oil energy accumulator. According to the die-casting machine die locking servo oil cylinder control system, the control valve group is integrated on the oil cylinder, and the force and displacement of the oil cylinder are accurately controlled through the flow control valve; by arranging two-stage hydraulic supporting of the first cartridge valve and the second cartridge valve, accurate positioning during stopping is achieved, and the car sliding condition is avoided; the control oil energy accumulator and the power oil energy accumulator are arranged, so that a power source can be provided when a fault occurs, and the current mold locking action is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of hydraulic control of die-casting machines, and in particular relates to a control system and method for a die-casting machine die-locking servo oil cylinder. Background Art

[0002] The die-casting machine is generally composed of injection system, clamping system, hydraulic transmission system and other components. The clamping cylinder is mainly used to control the die-casting machine's mold opening and closing system. The left and right sides of the clamping cylinder are the rodless cavity and rod cavity of the clamping cylinder. The function of the clamping system is to provide power for the various actions required by the die-casting machine according to the process. Therefore, the clamping cylinder adopts hydraulic transmission to meet the pressure, speed and other requirements of various parts of the die-casting machine.

[0003] The clamping system of existing die-casting machines mostly adopts a decentralized arrangement of cylinders and control valve blocks, and performs force and displacement control through conventional valves and pump control; however, due to the long hydraulic pipeline, conventional hydraulic pumps have minimum speed limits and pressure fluctuations, resulting in low hydraulic control accuracy. In addition, during the die-casting process, the casting pressure in the mold cavity will change with the change of injection tonnage. The traditional control method cannot dynamically adjust the clamping force of the clamping cylinder in time, resulting in loose mold clamping and reduced casting yield. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention aims to propose a die-casting machine clamping servo cylinder control system and method to solve the problem that the existing control method cannot dynamically adjust the clamping force of the clamping cylinder in time, resulting in loose mold closing and reduced casting yield.

[0005] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0006] A die-casting machine die-locking servo oil cylinder control system, comprising a die-locking cylinder, a power oil circuit and a control oil circuit, wherein the die-locking cylinder comprises a rod chamber and a rodless chamber;

[0007] The power oil circuit includes a flow control valve, a power oil accumulator, a cartridge valve 1 and a cartridge valve 2. The second oil port P1 of the flow control valve is respectively connected to the rod chamber, the oil supply circuit and the power oil accumulator. The first oil port A1 of the flow control valve, the cartridge valve 1, the cartridge valve 2 and the rodless chamber are connected in sequence. The flow control valve, the rodless chamber and the power oil accumulator are respectively connected to the oil return tank T.

[0008] The control oil circuit includes shuttle valve 1, shuttle valve 2, shuttle valve 3, solenoid valve 1, solenoid valve 2, one-way throttle valve 1, one-way throttle valve 2 and a control oil accumulator. The second oil port B4 of the shuttle valve 1 is connected to the control oil circuit port X, and the first oil port A4 of the shuttle valve 1 is connected to the shuttle valve 2 and the shuttle valve 3 respectively.

[0009] The control oil port X1 of the shuttle valve 2, the solenoid valve 1, the one-way throttle valve 1, and the cartridge valve 1 are connected in sequence;

[0010] The shuttle valve 3, the solenoid valve 2, the one-way throttle valve 2, and the control oil port X2 of the solenoid valve 2 are connected in sequence.

[0011] Furthermore, the oil port of the rodless chamber is connected to the first oil port A9 of the cartridge valve three, and the second oil port B9 of the cartridge valve three is connected to the return oil tank T; the return oil port Y3 of the cartridge valve three is connected to the control oil return port Y through the overflow valve three.

[0012] Furthermore, the oil port of the rod chamber is provided with a pressure sensor 1 for detecting pressure fluctuations in the rod chamber.

[0013] Furthermore, the oil port of the rodless chamber is provided with a second pressure sensor for detecting pressure fluctuations in the rodless chamber.

[0014] Furthermore, the power oil accumulator is connected to the oil return tank T through an overflow valve 1.

[0015] Furthermore, the control oil accumulator is connected to the control oil return port Y through a second overflow valve.

[0016] A die-casting machine clamping servo cylinder control method, comprising:

[0017] Feeding and clamping, the solenoid valve 1 and the solenoid valve 2 are energized, the cartridge valve 1 and the cartridge valve 2 are opened, and the oil in the rod chamber, the power oil accumulator and the power oil port P are combined and then pass through the left position of the flow control valve, the cartridge valve 1 and the cartridge valve 2 in sequence and then enter the rodless chamber, so that the piston rod of the oil cylinder is extended to achieve clamping;

[0018] Dynamic pressure maintenance: when the oil cylinder reaches the clamping position, the solenoid valve 1 and the solenoid valve 2 remain energized, and the flow control valve switches to the middle position to maintain pressure. The pressure fluctuation in the rod cavity is detected by the pressure sensor 1, and the pressure fluctuation in the rodless cavity is detected by the pressure sensor 2. When the pressure sensor and the pressure sensor 2 detect a decrease in pressure, the left position of the flow control valve works to replenish the pressure of the system; when the pressure increases, the right position of the flow control valve works to relieve the pressure of the system.

[0019] During the return stroke to open the mold, the oil in the power oil accumulator and the power oil port P merge and enter the rod chamber; the solenoid valve 1 and the solenoid valve 2 are energized, and the oil in the rodless chamber passes through the cartridge valve 1 and the cartridge valve 2, and the right position of the flow control valve in turn, and then enters the return oil tank T, so that the piston rod of the oil cylinder retracts to realize mold opening;

[0020] When the equipment stops and the return stroke is in place, the solenoid valve 1 and the solenoid valve 2 are powered off, the flow control valve is switched to the middle position, and the cartridge valve 1 and the cartridge valve 2 are closed, which cuts off the oil in the rodless chamber, so that the oil cylinder returns accurately and there will be no slipping.

[0021] Furthermore, during the feeding mold locking, return mold opening and dynamic pressure holding, the first oil port A7 of the solenoid valve 1 is connected with the oil return port Y1, and the control oil in the control chamber of the cartridge valve 1 passes through the throttle valve side of the one-way throttle valve 1 and the solenoid valve 1 in turn and enters the control oil return port Y;

[0022] Similarly, cartridge valve 2 allows the control oil in the control chamber to enter the control oil return passage Y according to cartridge valve 1.

[0023] Furthermore, when the flow control valve works in the left position, the second oil port P1 is connected to the first oil port A1; when the flow control valve works in the right position, the first oil port A1 is connected to the oil drain port T1.

[0024] Compared with the prior art, the die-casting machine clamping servo cylinder control system and method described in the present invention have the following advantages:

[0025] (1) The die-casting machine clamping servo cylinder control system described in the present invention integrates a control valve group on the cylinder, and accurately controls its force and displacement through a flow control valve; by setting a two-stage hydraulic support of a cartridge valve 1 and a cartridge valve 2, accurate positioning is achieved when stopping, and the vehicle does not slip; by setting a control oil accumulator and a power oil accumulator, a power source can be provided in the event of a fault to ensure the current clamping action.

[0026] (2) The die-casting machine locking servo cylinder control method described in the present invention detects pressure fluctuations in the rod cavity through pressure sensor 1, and detects pressure fluctuations in the rodless cavity through pressure sensor 2; when pressure sensor 1 and pressure sensor 2 detect a decrease in pressure, the left position of the flow control valve works to replenish the pressure of the system; when pressure increase is detected, the right position of the flow control valve works to relieve the pressure of the system; the dynamic response and control accuracy of the locking cylinder are improved; when the casting pressure changes, a timely response can be made, thereby improving the yield rate of castings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0028] Figure 1 A schematic diagram of the overall structure provided by an embodiment of the present invention;

[0029] Figure 2 A schematic diagram of the structure of a cartridge valve 1 and a cartridge valve 2 provided in an embodiment of the present invention;

[0030] Figure 3 A schematic diagram of the third structure of a cartridge valve provided in an embodiment of the present invention;

[0031] Figure 4A schematic diagram of the structure of a flow control valve provided in an embodiment of the present invention.

[0032] Description of reference numerals:

[0033] 1. Rod chamber; 11. Pressure sensor 1; 2. Rodless chamber; 21. Pressure sensor 2; 3. Flow control valve; A1. First oil port; P1. Second oil port; Oil drain port T1; 31. Check valve; 4. Power oil accumulator; 51. Cartridge valve 1; 52. Cartridge valve 2; 53. Cartridge valve 3; 61. Shuttle valve 1; 62. Shuttle valve 2; 63. Shuttle valve 3; 71. Solenoid valve 1; 72. Solenoid valve 2; 81. One-way throttle valve 1; 82. One-way throttle valve 2; 9. Control oil accumulator; 91. Overflow valve 2; 10. Overflow valve 1; P. Power oil junction; T. Oil return tank; X. Control oil junction; Y. Control oil return junction. DETAILED DESCRIPTION

[0034] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0035] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0036] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0037] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0038] like Figures 1 to 4As shown, a die-casting machine die-locking servo oil cylinder control system includes a die-locking cylinder, a power oil circuit and a control oil circuit, wherein the die-locking cylinder includes a rod chamber 1 and a rodless chamber 2;

[0039] The power oil circuit includes a flow control valve 3, a power oil accumulator 4, a cartridge valve 1 51 and a cartridge valve 2 52. The second oil port P1 of the flow control valve 3 is connected to the rod chamber 1, the power oil circuit port P and the power oil accumulator 4 respectively. The first oil port A1 of the flow control valve 3, the cartridge valve 1 51, the cartridge valve 2 52 and the rodless chamber 2 are connected in sequence.

[0040] The control oil circuit includes shuttle valve 1 61, shuttle valve 2 62, shuttle valve 3 63, solenoid valve 1 71, solenoid valve 2 72, one-way throttle valve 1 81, one-way throttle valve 2 82 and control oil accumulator 9, and the control oil circuit port X is respectively connected to the second oil port B4 of the shuttle valve 1 61, the flow control valve 3 and the control oil accumulator 9;

[0041] The first oil port A4 of the shuttle valve 1 61 is connected to the first oil port A2 of the cartridge valve 1 51 , and the oil outlet P2 of the shuttle valve 1 61 is connected to the first oil port A5 of the shuttle valve 2 62 and the second oil port B6 of the shuttle valve 3 63 respectively;

[0042] The second oil port B5 of the shuttle valve 62 is connected to the first oil port A1 of the flow control valve 3; the oil outlet P3 of the shuttle valve 62 is connected to the second oil port P5 of the solenoid valve 71, the first oil port A7 of the solenoid valve 71, the one-way throttle valve 81, and the control oil port X1 of the cartridge valve 51 are connected in sequence, and the return oil port Y1 of the solenoid valve 71 is connected to the control oil return port Y;

[0043] The first oil port A6 of the shuttle valve 3 63 is connected to the second oil port B3 of the cartridge valve 2 52, the oil outlet P4 of the shuttle valve 3 63 is connected to the second oil port P6 of the solenoid valve 2 72, the first oil port A8 of the solenoid valve 2 72, the one-way throttle valve 2 82, and the control oil port X2 of the solenoid valve 2 72 are connected in sequence, and the oil return port Y2 of the solenoid valve 2 72 is connected to the control oil return port Y;

[0044] The oil drain port T1 , the rodless chamber 2 , and the power oil port P of the flow control valve 3 are connected to the oil return tank T respectively.

[0045] The die-casting machine clamping servo oil cylinder control system of the present invention integrates the control valve group on the oil cylinder, and accurately controls the force and displacement thereof through the flow control valve; by setting the two-stage hydraulic support of the cartridge valve 1 and the cartridge valve 2, accurate positioning is achieved when stopping, and the vehicle does not slip; by setting the control oil accumulator and the power oil accumulator, a power source can be provided in case of a fault to ensure the current clamping action;

[0046] The power oil port P is connected to the external oil pump; the control oil port X is connected to the external control oil pipeline; the control oil return port Y is connected to the external oil return pipeline; the elastic change of the external oil circuit will not affect the control accuracy of the clamping cylinder.

[0047] The function of shuttle valve 1 61, shuttle valve 2 62 and shuttle valve 3 63 is to control the selection of oil pressure. The higher oil pressure of port A and port B will be connected to port P, thereby controlling the switch of cartridge valve 1 51 and cartridge valve 2 52.

[0048] The one-way throttle valve controls the opening speed of the cartridge valve 1 51 and the cartridge valve 2 52 by manually adjusting the opening degree of the one-way throttle valve 1 81 and the one-way throttle valve 2 82 .

[0049] In a preferred embodiment of the present invention, the first oil port A1 of the flow control valve 3 is connected to the second oil port B2 of the cartridge valve 1 51, the first oil port A2 of the cartridge valve 1 51 is connected to the first oil port A3 of the cartridge valve 2 52, and the second oil port B3 of the cartridge valve 2 52 is connected to the rodless chamber 2.

[0050] In actual use, the flow control valve 3 is a two-position three-way proportional flow control valve, which accurately controls the force and displacement of the cylinder.

[0051] In a preferred embodiment of the present invention, a one-way valve 31 is provided between the second oil port P1 of the flow control valve 3 and the power oil port P.

[0052] In actual use, the one-way valve 31 is used to prevent the power oil from flowing back, so as to avoid mutual influence between different actuators.

[0053] In a preferred embodiment of the present invention, the oil port of the rodless chamber 2 is connected to the first oil port A9 of the cartridge valve three 53, and the second oil port B9 of the cartridge valve three 53 is connected to the return oil tank T; the return oil port Y3 of the cartridge valve three 53 is connected to the control oil return port Y through the overflow valve three 22.

[0054] In actual use, when the oil pressure in the rodless chamber increases instantaneously, the oil in the rodless chamber 2 enters the return oil tank T through the first oil port A9 and the second oil port B9 of the cartridge valve three 53; the oil in the rodless chamber 2 overflows through the cartridge valve three 53 and the overflow valve three 22 to protect the system safety.

[0055] In a preferred embodiment of the present invention, the oil port of the rod chamber 1 is provided with a pressure sensor 11 for detecting pressure fluctuations in the rod chamber 1 .

[0056] The oil port of the rodless chamber 2 is provided with a pressure sensor 21 for detecting pressure fluctuations in the rodless chamber 2 .

[0057] In actual use, the pressure fluctuations of the rod cavity 1 and the rod cavity 2 are monitored in real time through the pressure sensor 11 and the pressure sensor 2 21. When the casting pressure changes, it can respond in time, thereby improving the yield rate of the casting.

[0058] In a preferred embodiment of the present invention, the power oil accumulator 4 is connected to the oil return tank T through an overflow valve 10.

[0059] In actual use, the pressure of the power oil circuit is ensured to be stable through the overflow valve 10. If the pressure of the power oil circuit is too high, the pressure is unloaded through this valve. The power oil accumulator 4 ensures the stability of the main oil circuit pressure and supplements the instantaneous high-speed action flow demand of the clamping cylinder; it ensures that the clamping cylinder can continue to work for a short time if the main oil pump fails.

[0060] In a preferred embodiment of the present invention, the control oil accumulator 9 is connected to the control oil return port Y via a second overflow valve 91 .

[0061] In actual use, the pressure stability of the control oil circuit is ensured by the overflow valve 2 91. If the control oil pressure is too high, the load is unloaded through this valve. The pressure stability of the control oil circuit is ensured by the control oil accumulator 9, the demand for instantaneous large control flow is supplemented, the action response of the controlled flow control valve 3 is improved, and it is ensured that the flow control valve 3 can continue to work for a short time in the event of a control oil pump failure.

[0062] In a preferred embodiment of the present invention, the flow control valve 3 is connected to the control oil return passage Y.

[0063] A die-casting machine clamping servo cylinder control method, comprising:

[0064] Feeding and clamping, the solenoid valve 1 71 and the solenoid valve 2 72 are energized, the cartridge valve 1 51 and the cartridge valve 2 52 are opened, and the oil in the rod chamber 1, the power oil accumulator 4 and the power oil port P are combined and sequentially pass through the left position of the flow control valve 3, the cartridge valve 1 51 and the cartridge valve 2 52 and then enter the rodless chamber 2, so that the piston rod of the oil cylinder is extended to achieve clamping;

[0065] The flow control valve 3 works in the left position, and the second oil port P1 is connected to the first oil port A1;

[0066] Dynamic pressure maintenance: when the oil cylinder reaches the clamping position, the solenoid valve 1 71 and the solenoid valve 2 72 remain energized, and the flow control valve 3 switches to the middle position to maintain pressure. The pressure fluctuation in the rod chamber 1 is detected by the pressure sensor 11, and the pressure fluctuation in the rodless chamber 2 is detected by the pressure sensor 21. When the pressure sensor 11 and the pressure sensor 21 detect a decrease in pressure, the flow control valve 3 works at the left position to replenish the pressure of the system; when the pressure increases, the flow control valve 3 works at the right position, and the first oil port A1 is connected to the oil drain port T1 to relieve the pressure of the system.

[0067] During the return stroke to open the mold, the oil in the power oil accumulator 4 and the power oil port P merge and enter the rod chamber 1; the solenoid valve 1 71 and the solenoid valve 2 72 are energized, and the oil in the rodless chamber 2 passes through the cartridge valve 1 51 and the cartridge valve 2 52 and the right position of the flow control valve 3 in sequence and enters the return oil tank T, so that the piston rod of the oil cylinder is retracted to realize mold opening;

[0068] When the equipment stops and the return stroke is in place, the solenoid valve 1 71 and the solenoid valve 2 72 are powered off, the flow control valve 3 is switched to the middle position, the cartridge valve 1 51 and the cartridge valve 2 52 are closed, which cuts off the oil in the rodless chamber 2, so that the cylinder return stroke is accurately in place without slipping.

[0069] The die-casting machine clamping servo cylinder control method described in the present invention detects pressure fluctuations in a rod cavity through pressure sensor 1, and detects pressure fluctuations in a rodless cavity through pressure sensor 2; when pressure sensor 1 and pressure sensor 2 detect a pressure drop, the left position of the flow control valve works to replenish the pressure of the system; when pressure increase is detected, the right position of the flow control valve works to relieve the pressure of the system; the dynamic response and control accuracy of the clamping cylinder are improved; when the casting pressure changes, a timely response can be made, thereby improving the yield rate of castings.

[0070] In actual use, when feeding and clamping, when the control system receives the feeding and clamping instruction, the solenoid valve 71 on the cover plate of the cartridge valve 51 is energized, the flow control valve 3 gradually switches to the left station, and the second oil port P1→first oil port A1 is gradually opened, and the oil in the rod chamber 1 and the power oil accumulator 4 merges with the oil from the pump station at the power oil junction P and enters the rodless chamber 2 of the clamping cylinder through the flow control valve 3, the cartridge valve 51, and the cartridge valve 2 52; by controlling the electrical signal of the flow control valve 3, the slow feeding, fast feeding, deceleration stop, and clamping in place of the clamping cylinder are realized to achieve precise positioning;

[0071] When the control system receives the return stroke mold opening instruction, the oil from the pump station at the power oil junction P and the oil in the power oil accumulator 4 merge into the rod chamber 1 of the locking cylinder; the solenoid valve 1 71 and the solenoid valve 2 72 on the cover plates of the cartridge valve 1 51 and the cartridge valve 2 52 are energized, and the oil in the rodless chamber 2 returns to the oil tank through the cartridge valve 1 51, the cartridge valve 2 52 and the flow control valve 3, and the flow control valve 3 gradually switches to the right work station, and the first oil port A1→the drain port T1 gradually opens, and by controlling the electrical signal of the flow control valve 3, the slow return stroke, fast return stroke, deceleration stop and return stroke in place of the locking cylinder are realized to achieve precise positioning.

[0072] When the equipment stops, the solenoid valve 1 71 and the solenoid valve 2 72 on the cover plates of the cartridge valve 1 51 and the cartridge valve 2 52 are powered off, and the flow control valve 3 is switched to the middle position. At this time, the rod chamber 1 is always acted upon by the pressure oil of the power oil accumulator 4, and the oil in the rodless chamber 2 is acted upon by the cut-off effect of the two-stage cartridge valves of the cartridge valve 1 51 and the cartridge valve 2 52, thereby achieving precise positioning of the clamping cylinder and preventing slippage.

[0073] In a preferred embodiment of the present invention, during the feeding mold locking, return mold opening and dynamic pressure holding, the first oil port A7 of the solenoid valve 71 is connected to the oil return port Y1, and the control oil in the control chamber of the cartridge valve 51 passes through the throttle valve side of the one-way throttle valve 81 and the solenoid valve 71 in sequence and then enters the control oil return port Y;

[0074] Similarly, the cartridge valve 2 52 allows the control oil in the control chamber to enter the control oil return passage Y according to the cartridge valve 1 51.

[0075] In actual use, the throttle valve of the one-way throttle valve 81 can be manually controlled to open quickly. The oil in the control chamber of the cartridge valve 51 passes through the first oil port A7 of the solenoid valve 71 and the return oil port Y1, and is connected to the control oil return port Y, and is discharged back to the oil tank without pressure. At this time, the oil pressure on both sides of the oil ports A and B of the shuttle valve 1 61, the shuttle valve 2 62, and the shuttle valve 3 63 has no selection effect, and will be cut off at the solenoid valve 1 71 and the solenoid valve 2 72, without acting on the cartridge valve 1 51 and the cartridge valve 2 52, thereby ensuring that the cartridge valve 1 51 and the cartridge valve 2 52 are both in the open state.

[0076] In a preferred embodiment of the present invention, when the equipment stops, when the pressure at the first oil port A4 of the shuttle valve 1 61 is greater than the pressure at the second oil port B6, the first oil port A4 is connected to the oil outlet P2, and the control oil passes through the shuttle valve 1 61 from the control oil port X and enters the shuttle valve 2 62 and the shuttle valve 3 63 respectively; when the pressure at the first oil port A4 of the shuttle valve 1 61 is less than the pressure at the second oil port B6, the second oil port B6 is connected to the oil outlet P2, and the oil passes through the shuttle valve 1 61 from the first oil port A2 of the cartridge valve 1 51 and enters the shuttle valve 2 62 and the shuttle valve 3 63 respectively;

[0077] When the pressure at the first oil port A4 of the shuttle valve 2 62 is greater than the pressure at the second oil port B5, the first oil port A4 is connected to the oil outlet P3, and the control oil enters the shuttle valve 2 62 from the shuttle valve 1 61; when the pressure at the first oil port A4 of the shuttle valve 2 62 is less than the pressure at the second oil port B5, the oil enters the shuttle valve 2 62 from the first oil port A1 of the flow control valve 3; the control oil enters the control chamber of the cartridge valve 1 51 from the shuttle valve 2 62 through the solenoid valve 1 71 and the one-way valve side of the one-way throttle valve 1 81 in sequence, so that the cartridge valve 1 51 is closed, wherein the second oil port P5 of the solenoid valve 1 71 is connected to the first oil port A7, and the throttle valve side of the one-way throttle valve 1 81 does not play a throttling role;

[0078] When the pressure at the second oil port B6 of shuttle valve three 63 is greater than the pressure at the first oil port A6, the second oil port B6 is connected to the oil outlet P4, and the control oil enters shuttle valve three 63 from shuttle valve one 61; when the pressure at the second oil port B6 of shuttle valve three 63 is less than the pressure at the first oil port A6, the oil enters shuttle valve three 63 from the second oil port B3 of cartridge valve two 52; the control oil enters the control chamber of cartridge valve two 52 from shuttle valve three 63 through the one-way valve of solenoid valve two 72 and one-way throttle valve two 82 in sequence, so that the cartridge valve two 52 is closed; among which the second oil port P6 of solenoid valve two 72 is connected to the first oil port A8, and the throttle valve side of one-way throttle valve two 82 does not play a throttling role.

[0079] In actual use, the two-stage cartridge valves 51 and 52 are closed to ensure that the clamping cylinder stops accurately at a certain position without slipping; a displacement sensor is built into the cylinder to provide feedback for displacement control.

[0080] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A die-casting machine clamping servo oil cylinder control system, comprising a clamping cylinder, a power oil circuit and a control oil circuit, wherein the clamping cylinder comprises a rod chamber and a rodless chamber; characterized in that: The power oil circuit includes a flow control valve, a power oil accumulator, a cartridge valve 1 and a cartridge valve 2. The second oil port P1 of the flow control valve is respectively connected to the rod chamber, the oil supply circuit and the power oil accumulator. The first oil port A1 of the flow control valve, the cartridge valve 1, the cartridge valve 2 and the rodless chamber are connected in sequence. The flow control valve, the rodless chamber and the power oil accumulator are respectively connected to the oil return tank T. The control oil circuit includes shuttle valve 1, shuttle valve 2, shuttle valve 3, solenoid valve 1, solenoid valve 2, one-way throttle valve 1, one-way throttle valve 2 and a control oil accumulator. The second oil port B4 of the shuttle valve 1 is connected to the control oil circuit port X, and the first oil port A4 of the shuttle valve 1 is connected to the shuttle valve 2 and the shuttle valve 3 respectively. The control oil port X1 of the shuttle valve 2, the solenoid valve 1, the one-way throttle valve 1, and the cartridge valve 1 are connected in sequence; The shuttle valve 3, the solenoid valve 2, the one-way throttle valve 2, and the control oil port X2 of the solenoid valve 2 are connected in sequence.

2. The die-casting machine clamping servo cylinder control system according to claim 1 is characterized in that: The oil port of the rodless chamber is connected to the first oil port A9 of the cartridge valve three, and the second oil port B9 of the cartridge valve three is connected to the oil return tank T; the oil return port Y3 of the cartridge valve three is connected to the control oil return port Y through the overflow valve three.

3. The die-casting machine clamping servo cylinder control system according to claim 1 is characterized in that: The oil port of the rod chamber is provided with a pressure sensor 1 for detecting pressure fluctuations in the rod chamber.

4. The die-casting machine clamping servo cylinder control system according to claim 1, characterized in that: The oil port of the rodless chamber is provided with a second pressure sensor for detecting pressure fluctuations in the rodless chamber.

5. The die-casting machine clamping servo cylinder control system according to claim 1, characterized in that: The power oil accumulator is connected to the oil return tank T through an overflow valve 1.

6. The die-casting machine clamping servo cylinder control system according to claim 1, characterized in that: The control oil accumulator is connected to the control oil return port Y through a second overflow valve.

7. A die-casting machine clamping servo cylinder control method, characterized in that: include Feeding and clamping, the solenoid valve 1 and the solenoid valve 2 are energized, the cartridge valve 1 and the cartridge valve 2 are opened, and the oil in the rod chamber, the power oil accumulator and the power oil port P are combined and then pass through the left position of the flow control valve, the cartridge valve 1 and the cartridge valve 2 in sequence and then enter the rodless chamber, so that the piston rod of the oil cylinder is extended to achieve clamping; Dynamic pressure maintenance: when the oil cylinder reaches the clamping position, the solenoid valve 1 and the solenoid valve 2 remain energized, and the flow control valve switches to the middle position to maintain pressure. The pressure fluctuation in the rod cavity is detected by the pressure sensor 1, and the pressure fluctuation in the rodless cavity is detected by the pressure sensor 2. When the pressure sensor and the pressure sensor 2 detect a decrease in pressure, the left position of the flow control valve works to replenish the pressure of the system; when the pressure increases, the right position of the flow control valve works to relieve the pressure of the system. During the return stroke to open the mold, the oil in the power oil accumulator and the power oil port P merge and enter the rod chamber; the solenoid valve 1 and the solenoid valve 2 are energized, and the oil in the rodless chamber passes through the cartridge valve 1 and the cartridge valve 2, and the right position of the flow control valve in turn, and then enters the return oil tank T, so that the piston rod of the oil cylinder retracts to realize mold opening; When the equipment stops and the return stroke is in place, the solenoid valve 1 and the solenoid valve 2 are powered off, the flow control valve is switched to the middle position, and the cartridge valve 1 and the cartridge valve 2 are closed, which cuts off the oil in the rodless chamber, so that the oil cylinder returns accurately and there will be no slipping.

8. The die-casting machine clamping servo cylinder control method according to claim 7, characterized in that: During the feeding mold locking, return mold opening and dynamic pressure holding, the first oil port A7 of the solenoid valve 1 is connected with the oil return port Y1, and the control oil in the control chamber of the cartridge valve 1 passes through the throttle valve side of the one-way throttle valve 1 and the solenoid valve 1 in turn and enters the control oil return port Y; Similarly, cartridge valve 2 allows the control oil in the control chamber to enter the control oil return passage Y according to cartridge valve 1.

9. The die-casting machine clamping servo cylinder control method according to claim 7, characterized in that: When the flow control valve works in the left position, the second oil port P1 is connected to the first oil port A1; when the flow control valve works in the right position, the first oil port A1 is connected to the oil drain port T1.

Images