Injection control oil passage, die casting machine, and injection control method

Abstract

The application discloses a pressure injection control oil circuit, a die casting machine and a pressure injection control method, and relates to the pressure injection technology field of the die casting machine, wherein the pressure injection control oil circuit comprises an oil supply system, an insertion valve and a servo valve; the oil supply system is connected with a pressure injection cavity pipeline of a pressure injection cylinder; the insertion valve is arranged on the pipeline; the oil supply system is further connected with a control cavity of the insertion valve; and the insertion valve is closed or opened by the inflow or outflow of hydraulic oil in the control cavity. The servo valve is provided with a control device for adjusting the opening degree; the servo valve is connected with a rod cavity of the pressure injection cylinder; the pressure injection cavity and the rod cavity are communicated; when the pressure injection control oil circuit is in an outlet throttling state, the insertion valve is in a fully open state; the control device adjusts the opening degree of the servo valve to control the pressure injection speed; when the pressure injection control oil circuit is in an inlet throttling state, the servo valve is in a fully open state; the hydraulic oil adjusts the opening degree of the insertion valve to control the pressure injection speed; and in summary, the pressure injection control oil circuit can make the die casting machine have two speed regulation modes of the outlet throttling and the inlet throttling.

Description

Technical Field

[0001] This invention relates to the field of injection technology for die casting machines, and particularly to an injection control oil circuit, a die casting machine, and an injection control method. Background Technology

[0002] A die casting machine is a machine used for pressure casting, commonly used in the production and processing of automotive parts. Under pressure, the die casting machine injects molten metal into a mold to cool and solidify, resulting in a solid metal casting after the mold is opened.

[0003] The injection process of existing cold chamber die casting machines can be divided into three stages: the first stage is slow injection, the second stage is fast injection, and the third stage is pressurized injection. The slow injection stage requires a stable low speed to ensure that the venting process before rapid filling does not entrap air, thus guaranteeing molding quality. The fast injection stage is a rapid filling and molding process before the molten metal cools. Because the alloy solution has a low freezing point, the injection rod needs to accelerate quickly before the molten metal solidifies in the rapid filling stage to achieve good molding. Therefore, adjusting the injection speed of the die casting machine determines the quality of the molded product.

[0004] In existing die-casting machines, the injection speed adjustment in the fast injection stage typically employs two methods: outlet throttling and inlet throttling. The two control methods operate on different principles. The outlet throttling method controls the speed of the injection piston by using a flow control valve (such as a servo valve) to control the flow rate of hydraulic oil discharged from the rod chamber of the injection cylinder. The inlet throttling method controls the speed of the injection piston by using a flow control valve (such as an adjustable cartridge valve) to control the flow rate of hydraulic oil supplied to the rodless chamber of the injection cylinder.

[0005] Inlet throttling typically employs open-loop control, which is low-cost and simple to control, but speed cannot be set. Outlet throttling, on the other hand, uses closed-loop control, allowing direct speed setting, high speed regulation accuracy, and strong resistance to external interference, but it is more expensive. Existing die-casting machines can only adjust the injection speed by setting either the outlet or inlet throttling method. Users cannot choose the appropriate method based on the complexity of the die-casting process, resulting in poor versatility. Summary of the Invention

[0006] The main objective of this invention is to propose an injection control oil circuit, a die-casting machine, and an injection control method, aiming to improve the problems of complex structure and poor versatility of the two throttling modes of the die-casting machine.

[0007] To achieve the above objectives, the injection control oil circuit proposed in this invention includes: The oil supply system is used to supply hydraulic oil to the injection chamber of the injection cylinder; A cartridge valve, connected to the oil supply system, is used to control the flow rate of hydraulic oil supplied by the oil supply system to the injection chamber. The opening degree of the cartridge valve is mechanically adjustable. A servo valve is connected to the rod chamber of the injection cylinder, and the opening degree of the servo valve is adjusted by a control device. When the injection control oil circuit is in the outlet throttling state, the cartridge valve is fully open, and the injection speed is controlled by adjusting the opening of the servo valve. When the injection control oil circuit is in the inlet throttling state, the servo valve is fully open, and the injection speed is controlled by adjusting the opening of the cartridge valve.

[0008] In one embodiment, the injection control oil circuit further includes a first hydraulic line and a control unit. The first hydraulic line connects the oil supply system and the control chamber of the cartridge valve. A first solenoid directional valve is provided on the first hydraulic line. When the injection control oil circuit is in an outlet throttling state, the control unit controls the first solenoid directional valve to be energized so that the cartridge valve opens.

[0009] In one embodiment, the injection control oil circuit further includes a second hydraulic line, on which a second solenoid directional valve and a third solenoid directional valve are provided. The second hydraulic line is connected to the first hydraulic line so that the second solenoid directional valve and the third solenoid directional valve are connected in parallel with the first solenoid directional valve. When the injection control oil circuit is in an inlet throttling state, the control unit controls the first solenoid directional valve, the second solenoid directional valve, and the third solenoid directional valve to be energized so that the cartridge valve opens.

[0010] In one embodiment, the first electromagnetic directional valve, the second electromagnetic directional valve, and the third electromagnetic directional valve are respectively connected to the oil tank. The third electromagnetic directional valve is located on the side of the second electromagnetic directional valve closer to the oil supply system. The pipeline between the first electromagnetic directional valve and the oil tank is connected to the return oil channel of the third electromagnetic directional valve.

[0011] In one embodiment, a throttle valve is provided on the pipeline between the first electromagnetic reversing valve and the oil tank, and the opening of the throttle valve can be mechanically adjusted.

[0012] In one embodiment, the injection control circuit further includes an accumulator located between the oil supply system and the cartridge valve.

[0013] In one embodiment, the injection control oil circuit further includes a first check valve and a second check valve. The first check valve is located on the pipeline between the oil supply system and the accumulator. The hydraulic oil of the oil supply system and the hydraulic oil flowing through the cartridge valve enter the injection chamber of the injection cylinder through the second check valve.

[0014] The present invention also proposes a die-casting machine, including the die-casting machine in any of the foregoing embodiments.

[0015] This invention also proposes an injection control method, using the die-casting machine described above, which has two speed regulation modes: outlet throttling and inlet throttling. The injection control method includes: When the die-casting machine is in the slow speed section of the outlet throttling, the servo valve is adjusted to make the hydraulic oil passing through it reach the first flow value, and the cartridge valve is controlled to the preset opening degree and gradually changed to full opening, so that the flow rate of hydraulic oil passing through the cartridge valve gradually increases. When the die-casting machine reaches the outlet throttling rapid section, the servo valve is adjusted to make the hydraulic oil passing through a second flow rate value, which is greater than the first flow rate value.

[0016] In one embodiment, the injection control method further includes the following steps: When the die-casting machine is in the inlet throttling slow speed section, the servo valve is adjusted to be fully open, the cartridge valve is controlled to be closed, and the injection speed is controlled through the oil supply system. When the die-casting machine reaches the inlet throttling rapid section, the cartridge valve is adjusted to open so that the hydraulic oil passing through is at the third flow rate value.

[0017] The technical solution of this invention uses a cartridge valve and a servo valve to control the flow rate of hydraulic oil in the oil supply system, enabling the injection control oil circuit to have both outlet throttling and inlet throttling modes. Specifically, the injection control oil circuit includes an oil supply system, a cartridge valve, and a servo valve. The oil supply system pipeline is connected to the injection chamber of the injection cylinder. The cartridge valve is located on this pipeline, and the position to which the valve core of the cartridge valve can be opened is limited by a motor drive or handwheel adjustment. Adjusting the opening degree of the cartridge valve controls the flow rate of hydraulic oil injected into the injection chamber by the oil supply system. The oil supply system is also connected to the control chamber of the cartridge valve. The inflow or outflow of hydraulic oil into or from the control chamber can close or open the cartridge valve. The servo valve has a control device for adjusting the opening degree. The servo valve is connected to the rod chamber of the injection cylinder, and the injection chamber and the rod chamber are connected. Hydraulic oil enters the injection chamber, flows through the rod chamber, and then flows to the servo valve, which can control the injection speed of the injection rod.

[0018] Die-casting machines generally have slow injection and fast injection processes, and the injection speed is adjusted through two methods: outlet throttling and inlet throttling. When the outlet throttling mode is used and the die-casting machine is in the slow injection process, the servo valve is at a low opening, controlling the cartridge valve to open to a suitable opening, and controllably gradually changing to a fully open state. The hydraulic oil from the oil supply system enters the injection chamber, pushing the injection rod to move. The gradual full opening of the cartridge valve can avoid speed fluctuations or impacts in the slow injection stage, ensuring the smoothness of the injection process. When the injection rod moves to the fast injection trigger position, the servo valve opens from a low opening to a high opening. The injection speed in the fast injection stage is adjusted by the servo valve so that the die-casting machine enters the outlet throttling state.

[0019] When the inlet throttling mode is used and the die-casting machine is in a slow injection process, the servo valve is fully open, the cartridge valve is closed, and hydraulic oil is slowly injected into the injection chamber by the oil supply system. When the injection rod reaches the fast injection trigger position, the hydraulic oil controls the cartridge valve to open. The injection speed is controlled by adjusting the opening of the cartridge valve, so that the die-casting machine enters the inlet throttling state. In summary, this injection control oil circuit can select either of the two throttling modes for speed adjustment, making it more versatile. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 the present invention. 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 This is a schematic diagram of the inlet throttling slow section in one embodiment of the injection control oil circuit provided by the present invention; Figure 2 A schematic diagram of the inlet throttling rapid section in one embodiment of the injection control oil circuit provided by the present invention; Figure 3 This is a schematic diagram of the outlet throttling slow section in one embodiment of the injection control oil circuit provided by the present invention; Figure 4 This is a schematic diagram of the outlet throttling block speed section in one embodiment of the injection control oil circuit provided by the present invention.

[0022] Explanation of icon numbers: 100. Injection control oil circuit; 110. Oil supply system; 120. Cartridge valve; 121. Opening adjustment device; 130. Servo valve; 131. Control device; 140. First hydraulic line; 141. First solenoid directional valve; 142. First return oil line; 143. Throttle valve; 150. Second hydraulic line; 151. Second solenoid directional valve; 152. Third solenoid directional valve; 153. Second return oil line; 160. Oil tank; 170. Accumulator; 180. First check valve; 190. Second check valve; 200, Injection cylinder; 210, Injection chamber; 220, Rod chamber.

[0023] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] It should be noted that if the embodiments of the present invention 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.

[0026] Furthermore, if the embodiments of this invention 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. Thus, 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 invention.

[0027] This invention proposes a pressure injection control oil circuit 100.

[0028] Please see Figures 1 to 4 In one embodiment of the present invention, the injection control oil circuit 100 includes an oil supply system 110, a cartridge valve 120, and a servo valve 130. The oil supply system 110 is connected to the injection chamber 210 of the injection cylinder 200. The cartridge valve 120 is disposed on the pipeline. The position that the valve core of the cartridge valve 120 can open is limited by the motor drive or handwheel adjustment. The opening degree of the cartridge valve 120 is adjusted to control the flow rate of hydraulic oil injected into the injection chamber 210 by the oil supply system 110. The oil supply system 110 is also connected to the control chamber of the cartridge valve 120. The flow of hydraulic oil into or out of the control chamber can cause the cartridge valve 120 to close or open. The servo valve 130 has a control device 131 for adjusting the opening. The servo valve 130 is connected to the rod chamber 220 of the injection cylinder 200. The injection chamber 210 and the rod chamber 220 are connected. Hydraulic oil enters the injection chamber 210, flows through the rod chamber 220 to the servo valve 130, and can control the injection speed of the injection rod.

[0029] Die-casting machines generally have slow injection and fast injection processes, and the injection speed is adjusted by two methods: outlet throttling and inlet throttling. When the outlet throttling mode is used and the die-casting machine is in the slow injection process, the servo valve 130 is at a low opening, controlling the cartridge valve 120 to open to a suitable opening, and can controllably gradually change to a fully open state. The direction indicated by the arrow on the pipeline in the figure is the direction of hydraulic oil flow. The hydraulic oil from the oil supply system 110 enters the injection chamber 210, pushing the injection rod to move. The gradual full opening of the cartridge valve 120 can avoid speed fluctuations or impacts in the slow injection stage, ensuring the smoothness of the injection process. When the injection rod moves to the fast injection trigger position, the servo valve 130 opens from a low opening to a high opening, and the injection speed in the fast injection stage is adjusted by the servo valve 130.

[0030] When the inlet throttling mode is used and the die-casting machine is in a slow injection process, the servo valve 130 is fully open, the cartridge valve 120 is closed, and hydraulic oil is slowly injected into the injection chamber 210 by the oil supply system 110. When the injection rod reaches the fast injection trigger position, the hydraulic oil controls the cartridge valve 120 to open, and the injection speed is controlled by adjusting the opening of the cartridge valve 120. In summary, the injection control oil circuit 100 can select either of the two throttling modes for speed adjustment, making it more versatile.

[0031] In one embodiment, the injection control oil circuit 100 further includes a first hydraulic line 140 and a control unit. The first hydraulic line 140 is connected to the oil supply system 110 and the control chamber of the cartridge valve 120. A first solenoid directional valve 141 is provided on the first hydraulic line 140. When the injection control oil circuit 100 is in the outlet throttling state, the control unit controls the first solenoid directional valve 141 to be energized so that the cartridge valve 120 is opened.

[0032] like Figure 3 and Figure 4As shown, in one embodiment of the present invention, the oil supply system 110 is connected to the control chamber of the cartridge valve 120 through the first hydraulic pipeline 140. The first hydraulic pipeline 140 is provided with a first electromagnetic directional valve 141, which is used to control the flow direction of hydraulic oil. When the control unit de-energizes the first electromagnetic directional valve 141, the hydraulic oil of the oil supply system 110 flows into the control chamber of the cartridge valve 120, causing the cartridge valve 120 to close, so as to stop the hydraulic oil from flowing through the cartridge valve 120 to the injection chamber 210 of the injection cylinder 200. When the control unit energizes the first electromagnetic directional valve 141, the hydraulic oil flows out of the control chamber of the cartridge valve 120, causing the cartridge valve 120 to open, so that the hydraulic oil of the oil supply system 110 flows into the injection chamber 210. By adjusting the hydraulic oil flow rate, the cartridge valve 120 is gradually changed to a fully open state, so that the injection control oil circuit 100 can meet the requirement of providing high flow hydraulic oil to the injection chamber 210. When the injection rod moves to the rapid injection stage position, the servo valve 130 is adjusted from a low opening degree to a high opening degree to realize rapid injection in the outlet throttling mode. The movement speed of the injection rod is determined by the opening speed of the servo valve 130.

[0033] In one embodiment, the injection control oil circuit 100 further includes a second hydraulic line 150, on which a second solenoid directional valve 151 and a third solenoid directional valve 152 are provided. The second hydraulic line 150 is connected to the first hydraulic line 140 so that the second solenoid directional valve 151 and the third solenoid directional valve 152 are connected in parallel with the first solenoid directional valve 141. When the injection control oil circuit 100 is in an inlet throttling state, the control unit controls the first solenoid directional valve 141, the second solenoid directional valve 151 and the third solenoid directional valve 152 to be energized so that the cartridge valve 120 is opened.

[0034] Please refer to Figure 1 and Figure 2 In one embodiment of the present invention, the injection control oil circuit 100 further includes a second hydraulic line 150, which is connected to the first hydraulic line 140. The second hydraulic line 150 is provided with a second electromagnetic directional valve 151 and a third electromagnetic directional valve 152 connected in parallel with the first electromagnetic directional valve 141. The hydraulic oil of the oil supply system 110 can enter the two hydraulic lines respectively. After the hydraulic oil of the two lines merges, it flows to the control chamber of the cartridge valve 120 as the control oil for switching the cartridge valve 120.

[0035] Understandably, the die-casting machine adopts an inlet throttling mode, with the servo valve 130 fully energized and open throughout the process. When the die-casting machine is in the slow injection stage, the oil supply system 110 is connected to the injection chamber 210 through an additional hydraulic pipeline. When the hydraulic oil pushes the injection rod to the starting point of rapid injection, the control unit controls the first solenoid directional valve 141 and the second solenoid directional valve 151 to de-energize and the third solenoid directional valve 152 to energize, controlling the hydraulic oil to flow into the first hydraulic pipeline 140 and the second hydraulic pipeline 150 respectively. After merging, the hydraulic oil flows into the control chamber of the cartridge valve 120, causing the cartridge valve 120 to close. When the injection rod reaches the rapid injection stage, the control unit controls the first solenoid directional valve 141, the second solenoid directional valve 151, and the third solenoid directional valve 152 to energize, controlling the cartridge valve 120 to open rapidly. Since the servo valve 130 remains fully open, rapid injection in the inlet throttling mode is achieved, and the opening degree of the cartridge valve 120 determines the movement speed of the injection rod.

[0036] In one embodiment, the first electromagnetic directional valve 141, the second electromagnetic directional valve 151, and the third electromagnetic directional valve 152 are respectively connected to the oil tank 160. The third electromagnetic directional valve 152 is located on the side of the second electromagnetic directional valve 151 that is close to the oil supply system 110. The pipeline between the first electromagnetic directional valve 141 and the oil tank 160 is connected to the return oil channel of the third electromagnetic directional valve 152.

[0037] Please refer to Figures 1 to 4 In one embodiment of the present invention, the first electromagnetic directional valve 141, the second electromagnetic directional valve 151, and the third electromagnetic directional valve 152 are respectively connected to the oil tank 160 through pipelines. When the injection control oil circuit 100 is in the inlet throttling state, the first electromagnetic directional valve 141, the second electromagnetic directional valve 151, and the third electromagnetic directional valve 152 are energized, so that the control chamber of the cartridge valve 120 is connected to the oil tank 160 through the three electromagnetic directional valves. The multi-discharge oil circuit can increase the discharge capacity, allowing the cartridge valve 120 to open rapidly in a short time, further... The third electromagnetic directional valve 152 on the second hydraulic line 150 is located on the side of the second electromagnetic directional valve 151 near the oil supply system 110, and the pipeline between the first electromagnetic directional valve 141 and the oil tank 160 is connected to the return oil channel of the third electromagnetic directional valve 152. The hydraulic oil in the control chamber of the cartridge valve 120 can flow back to the oil tank 160 through the first electromagnetic directional valve 141, the second electromagnetic directional valve 151 and the third electromagnetic directional valve 152, so as to realize the rapid start-up of the injection rod in the fast injection stage and ensure good filling of the molten metal.

[0038] In one embodiment, a throttle valve 143 is provided on the pipeline between the first electromagnetic reversing valve 141 and the oil tank 160, and the opening of the throttle valve 143 can be mechanically adjusted.

[0039] Please refer to Figures 1 to 4In order to adjust the opening speed of the cartridge valve 120 under the outlet throttling mode, in one embodiment of the present invention, the return oil channel of the first electromagnetic reversing valve 141 is connected to the oil tank 160 through the first return oil pipeline 142. A throttle valve 143 is provided on the first return oil pipeline 142. The opening degree of the throttle valve 143 can be mechanically adjusted to control the flow rate of hydraulic oil in the control chamber of the cartridge valve 120 back to the oil tank 160, so that the opening process of the cartridge valve 120 gradually and controllably reaches the fully open state, so that the oil supply increases slowly and matches the speed of the slow injection stage, avoiding speed fluctuations or impacts in the slow injection stage, thereby improving the stability of the slow injection stage and improving the molding quality of the product.

[0040] Furthermore, in the outlet throttling state, only the first solenoid directional valve 141 and the throttle valve 143 control the opening of the cartridge valve 120. In the inlet throttling state, the first solenoid directional valve 141, the second solenoid directional valve 151, and the third solenoid directional valve 152 are all energized. Therefore, the throttle valve 143 is positioned between the connection point of the first return oil line 142 and the second return oil line 153 and the oil tank 160, so that the hydraulic oil flows into the second return oil line 153 through the first solenoid directional valve 141 and finally flows back to the oil tank quickly through the third solenoid directional valve 152, thereby increasing the opening speed of the cartridge valve 120.

[0041] In one embodiment, the injection control oil circuit 100 further includes an accumulator 170 located between the oil supply system 110 and the cartridge valve 120.

[0042] Please refer to Figures 1 to 4 In one embodiment of the present invention, an accumulator 170 is provided on the pipeline between the oil supply system 110 and the cartridge valve 120. The accumulator 170 is used to release hydraulic oil into the pipeline to increase the flow rate and pressure of the hydraulic oil in the pipeline. When in the outlet throttling state, the opening process of the cartridge valve 120 is gradual, so that the oil supply speed of the accumulator 170 through the cartridge valve 120 slowly increases to match the speed of the slow injection stage, thus precisely controlling the speed of the slow injection stage. When the die-casting machine enters the fast injection stage, the accumulator 170 releases a large amount of hydraulic oil through the cartridge valve 120 into the injection chamber 210, so that the injection rod is rapidly injected.

[0043] In one embodiment, the injection control oil circuit 100 further includes a first check valve 180 and a second check valve 190. The first check valve 180 is located on the pipeline between the oil supply system 110 and the accumulator 170. The hydraulic oil from the oil supply system 110 and the hydraulic oil flowing through the cartridge valve 120 enter the injection chamber 210 of the injection cylinder 200 through the second check valve 190.

[0044] Please refer to Figures 1 to 4In one embodiment of the present invention, the injection control oil circuit 100 further includes a first check valve 180 and a second check valve 190. The first check valve 180 is installed on the pipeline between the oil supply system 110 and the accumulator 170 to prevent backflow of hydraulic oil in the accumulator 170 and the pipeline, so that the hydraulic oil discharged from the accumulator 170 flows to the injection chamber 210 of the injection cylinder 200, ensuring the flow rate and pressure of the hydraulic oil. The second check valve 190 is installed on the pipeline between the connection between the cartridge valve 120 and the oil supply system 110 and the injection chamber 210. After the hydraulic oil from the oil supply system 110 and the cartridge valve 120 merges, it enters the injection chamber 210 through the second check valve 190, preventing the hydraulic oil in the injection chamber 210 from flowing back, improving the stability of the injection process, and facilitating the subsequent pressure holding work of the die-casting machine.

[0045] The present invention also proposes a die casting machine, which includes an injection control oil circuit 100. The specific structure of the injection control oil circuit 100 is as described in the above embodiments. Since the 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, which will not be described in detail here.

[0046] This invention also proposes an injection control method, using the die-casting machine described above, which has two speed regulation modes: outlet throttling and inlet throttling. The injection control method includes: When the die-casting machine is in the slow speed section of the outlet throttling, the servo valve 130 is adjusted to a low opening by the control device 131 so that the hydraulic oil passing through is the first flow value. The first solenoid directional valve 141 is energized, the cartridge valve 120 is adjusted to a preset opening and gradually changed to full opening, so that the hydraulic oil flow through the cartridge valve 120 gradually increases. When the die-casting machine reaches the outlet throttling rapid section, the servo valve 130 is adjusted to a high opening degree by the control device 131 so that the hydraulic oil passing through is at the second flow rate value, which is greater than the first flow rate value.

[0047] In one embodiment, the injection control method further includes the following steps: When the die-casting machine is in the inlet throttling slow speed section, the servo valve 130 is adjusted to be fully open by the control device 131, the first electromagnetic reversing valve 141 and the second electromagnetic reversing valve 151 are de-energized, the third electromagnetic reversing valve 152 is energized, the cartridge valve 120 is closed, and the pressure oil is injected into the injection chamber 210 through the oil supply system 110 to control the injection speed. When the die-casting machine reaches the inlet throttling rapid section, the first solenoid directional valve 141, the second solenoid directional valve 151, and the third solenoid directional valve 152 are energized, causing the cartridge valve 120 to open and controlling the hydraulic oil passing through the cartridge valve 120 to the third flow value.

[0048] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A pressure injection control oil circuit, characterized in that, The injection control oil circuit includes: The injection cylinder includes an injection chamber and a rod chamber that are interconnected. An oil supply system, connected to the injection chamber, is used to supply hydraulic oil to the injection chamber; A cartridge valve, connected to the oil supply system, is used to control the flow rate of hydraulic oil supplied by the oil supply system to the injection chamber. The opening degree of the cartridge valve is mechanically adjustable. A servo valve, connected to the rod chamber, has its opening adjusted by a control device. When the injection control oil circuit is in an outlet throttling state, the cartridge valve is fully open, and the injection speed is controlled by adjusting the opening of the servo valve. When the injection control oil circuit is in an inlet throttling state, the servo valve is fully open, and the injection speed is controlled by adjusting the opening of the cartridge valve. The system comprises a first hydraulic line, a second hydraulic line, and a control unit. The first hydraulic line connects the oil supply system and the control chamber of the cartridge valve. A first solenoid directional valve is installed on the first hydraulic line. When the injection control oil circuit is in an outlet throttling state, the control unit energizes the first solenoid directional valve to open the cartridge valve. The second hydraulic line is equipped with a second solenoid directional valve and a third solenoid directional valve. The second hydraulic line connects to the first hydraulic line. The second and third solenoid directional valves are connected in parallel with the first solenoid directional valve. When the injection control oil circuit is in an inlet throttling state, the control unit energizes the first, second, and third solenoid directional valves to open the cartridge valve.

2. The injection control oil circuit as described in claim 1, characterized in that, The first electromagnetic reversing valve, the second electromagnetic reversing valve, and the third electromagnetic reversing valve are respectively connected to the oil tank. The third electromagnetic reversing valve is located on the side of the second electromagnetic reversing valve closer to the oil supply system. The pipeline between the first electromagnetic reversing valve and the oil tank is connected to the return oil channel of the third electromagnetic reversing valve.

3. The injection control oil circuit as described in claim 1, characterized in that, A throttle valve is provided on the pipeline between the first electromagnetic reversing valve and the oil tank, and the opening of the throttle valve can be mechanically adjusted.

4. The injection control oil circuit as described in any one of claims 1 to 3, characterized in that, The injection control circuit also includes an accumulator, which is located between the oil supply system and the cartridge valve.

5. The injection control oil circuit as described in claim 1, characterized in that, The injection control oil circuit also includes a first check valve and a second check valve. The first check valve is located on the pipeline between the oil supply system and the accumulator. The hydraulic oil of the oil supply system and the hydraulic oil flowing through the cartridge valve enter the injection chamber of the injection cylinder through the second check valve.

6. A die-casting machine, characterized in that, Includes the injection control oil circuit as described in any one of claims 1 to 5.

7. A pressure injection control method, characterized in that, The method utilizes the die-casting machine of claim 6, which has an outlet throttling mode and an inlet throttling mode. The injection control method includes the following steps: When the die-casting machine is in the slow speed section of the outlet throttling, the servo valve is adjusted to make the hydraulic oil passing through it reach the first flow value, and the cartridge valve is controlled to the preset opening degree and gradually changed to full opening, so that the flow rate of hydraulic oil passing through the cartridge valve gradually increases. When the die-casting machine reaches the outlet throttling rapid section, the servo valve is adjusted to make the hydraulic oil passing through a second flow rate value, which is greater than the first flow rate value.

8. The injection control method as described in claim 7, characterized in that, The injection control method further includes the following steps: When the die-casting machine is in the inlet throttling slow speed section, the servo valve is adjusted to be fully open, the cartridge valve is controlled to be closed, and the injection speed is controlled through the oil supply system. When the die-casting machine reaches the inlet throttling rapid section, the cartridge valve is adjusted to open so that the hydraulic oil passing through is at the third flow rate value.

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