Novel hydraulic circuit of injection system

Abstract

The invention relates to the technical field of injection systems, and particularly discloses a novel injection system hydraulic circuit which comprises a system oil way, an energy storage oil way and an injection oil way, the system oil way comprises a system oil port, and the energy storage oil way comprises a first energy accumulator. The injection oil way comprises an injection oil cylinder, a first proportional servo cartridge valve, a second proportional servo cartridge valve, a proportional servo direction control valve and an oil tank, the system oil port is communicated with the first proportional servo cartridge valve and the first energy accumulator at the same time, and an oil outlet of the first proportional servo cartridge valve is communicated with a rodless cavity of the injection oil cylinder; in other words, hydraulic oil provided by a system oil port can directly enter the rodless cavity of the injection oil cylinder through the first proportional servo cartridge valve to achieve the low-speed injection action of the injection oil cylinder, and can also enter the first energy accumulator firstly for energy storage, and then the first energy accumulator fills oil into the rodless cavity of the injection oil cylinder through the first proportional servo cartridge valve to achieve the low-speed injection action of the injection oil cylinder. The high-speed injection action is realized, and different injection requirements are met.

Description

Technical Field

[0001] The invention relates to the technical field of injection systems of injection molding machines, in particular to a novel hydraulic circuit of the injection system. Background Art

[0002] Injection molding is a widely used technology in the plastic processing industry for manufacturing plastic products of various shapes and sizes. Traditional injection molding machines usually use hydraulic systems to drive the injection unit, which is responsible for injecting molten plastic material into the mold cavity. However, traditional hydraulic systems have certain limitations in terms of response speed, accuracy and energy efficiency, which restricts the quality and efficiency of the injection molding process.

[0003] In the prior art, the injection system hydraulic oil circuit generally uses a solution combining an accumulator and a slide valve servo valve to perform the injection action, as shown in the attached manual. Figure 1 As shown, it mainly includes a charging and discharging circuit 4, a servo injection circuit and an injection cylinder 21, wherein the charging and discharging circuit 4 includes a system oil port 11, a charging valve group 41, a first accumulator 31 and a discharging valve group 42, and the servo injection circuit includes a slide valve servo valve 5, which is used for injection, ejection and storage back pressure, that is, the hydraulic oil control of all actions is completed by a slide valve servo valve 5; however, it has the following disadvantages: 1. The hydraulic oil flowing out of the system oil port must pass through the charging and discharging circuit 4, which cannot meet the system direct drive low-speed injection mode; 2. The use of the slide valve servo Although the servo valve can take into account injection, ejection and storage back pressure at the same time, if a small-diameter slide-type servo valve is used, its flow rate is limited. Even if two small-diameter slide-type servo valves are used in parallel, their flow rate is relatively limited. In addition, the use of multiple servo valves in parallel requires a larger installation space and is more expensive. The response speed of the entire system is also affected by a single servo valve; 3. If a large-diameter slide-type servo valve is used, its flow rate is relatively large, which can meet the working conditions of high-speed injection, but its step and frequency response data are not ideal, and it is not suitable for high-speed and high-precision injection conditions. Summary of the invention

[0004] The present invention is made in consideration of the above-mentioned problems. The purpose of the invention is to provide a new type of hydraulic circuit for an injection system, which can meet both the needs of high-speed injection and low-speed injection, and control the injection action of the injection cylinder through two independent proportional servo cartridge valves, and control the storage back pressure of the injection cylinder through a proportional servo directional control valve. It can meet all the action flow requirements of the injection cylinder, and at the same time can achieve high-pressure, high-speed, high-response and high-precision hydraulic control, thereby improving production efficiency and improving product molding quality.

[0005] To achieve the above object, the present invention provides a hydraulic circuit for a new injection system, which includes a system oil circuit, an energy storage oil circuit, and an injection oil circuit. The system oil circuit includes a system oil port, the energy storage oil circuit includes a first accumulator, and the injection oil circuit includes an injection cylinder, a first proportional servo cartridge valve, a second proportional servo cartridge valve, a proportional servo direction control valve, and a fuel tank. The system oil port is simultaneously connected to the first proportional servo cartridge valve and the first accumulator. The oil outlet of the first proportional servo cartridge valve is connected to the rodless cavity of the injection cylinder. The rod chamber of the injection cylinder can be connected to the fuel tank through the second proportional servo cartridge valve. The proportional servo direction control valve is located between the rodless cavity of the injection cylinder and the fuel tank; When the injection cylinder is in the low-speed injection state, both the first proportional servo cartridge valve and the second proportional servo cartridge valve are opened, and the system oil port is connected to the rodless cavity of the injection cylinder through the first proportional servo cartridge valve; When the injection cylinder is in the high-speed injection state, both the first proportional servo cartridge valve and the second proportional servo cartridge valve are opened, and the first accumulator is connected to the rodless cavity of the injection cylinder through the first proportional servo cartridge valve; When the injection cylinder is in the material storage state, the rodless cavity of the injection cylinder is connected to the fuel tank through the proportional servo direction control valve. The first proportional servo cartridge valve is closed and the second proportional servo cartridge valve is opened. The fuel tank is connected to the rod chamber of the injection cylinder through the second proportional servo cartridge valve.

[0006] For the above-mentioned hydraulic circuit of a new injection system, the system oil circuit further includes a first cartridge valve. The oil inlet of the first cartridge valve is connected to the system oil port. The oil outlet of the first cartridge valve is connected to the oil inlet of the first proportional servo cartridge valve through a first pipeline. The oil port of the first accumulator is connected to the first pipeline.

[0007] For the above-mentioned hydraulic circuit of a new injection system, the energy storage oil circuit further includes a control valve group. The control valve group is located between the first pipeline and the first accumulator and is used to control the on-off between the first pipeline and the first accumulator.

[0008] For the above-mentioned hydraulic circuit of a new injection system, the control valve group includes a second cartridge valve, a first shuttle valve, a first pilot valve, and a second pilot valve. The second cartridge valve is provided with a first oil port, a second oil port, and a control chamber. The first shuttle valve is provided with two third oil ports and a fourth oil port. Both of the two third oil ports are respectively connected to the first oil port and the second oil port. The fourth oil port can be connected to the control chamber through the first pilot valve and the second pilot valve.

[0009] For a hydraulic circuit of a novel injection system as described above, the first pilot valve is provided with a first oil inlet, a second oil inlet, a first oil outlet and a first electromagnet. The first oil inlet is communicated with the fourth oil port, and the second oil inlet is simultaneously communicated with one of the third oil ports and the second oil port. When the first electromagnet is energized, the first oil inlet is communicated with the first oil outlet. When the first electromagnet is de-energized, the second oil inlet is communicated with the first oil outlet; The second pilot valve is provided with a third oil inlet, a second oil outlet, a first variable oil port and a second electromagnet. The third oil inlet is communicated with the first oil outlet, the second oil outlet is communicated with the fuel tank, and the first variable oil port is communicated with the control chamber. When the second electromagnet is energized, the first variable oil port is communicated with the second oil outlet. When the second electromagnet is de-energized, the first variable oil port is communicated with the third oil inlet.

[0010] For a hydraulic circuit of a novel injection system as described above, the proportional servo direction control valve is provided with a fourth oil inlet, a third oil outlet and a third electromagnet. When the third electromagnet is energized, the fourth oil inlet can be communicated with the third oil outlet, and the third electromagnet can control the opening size between the fourth oil inlet and the third oil outlet.

[0011] For a hydraulic circuit of a novel injection system as described above, the first proportional servo cartridge valve is provided with a fourth electromagnet. When the fourth electromagnet is energized, it can control the first proportional servo cartridge valve to open and can control the opening size of the first proportional servo cartridge valve.

[0012] For a hydraulic circuit of a novel injection system as described above, the second proportional servo cartridge valve is provided with a fifth electromagnet. When the fifth electromagnet is energized, it can control the second proportional servo cartridge valve to open and can control the opening size of the second proportional servo cartridge valve.

[0013] For a hydraulic circuit of a novel injection system as described above, the injection oil circuit further includes a third cartridge valve, a third pilot valve and a second shuttle valve. The oil inlet of the third cartridge valve is communicated with the system oil port, the oil outlet of the third cartridge valve is communicated with the rodless cavity of the injection cylinder, and the third pilot valve can control the third cartridge valve to open or close through the second shuttle valve.

[0014] For a hydraulic circuit of a novel injection system as described above, the injection oil circuit further includes a first pressure sensor, a second pressure sensor and an injection position gauge. The first pressure sensor is used to monitor the oil pressure in the rodless cavity of the injection cylinder, the second pressure sensor is used to monitor the oil pressure in the rod cavity of the injection cylinder, and the injection position gauge is used to monitor the position of the piston rod of the injection cylinder.

[0015] The present invention has the following beneficial effects: 1. It is possible to directly supply oil to the first proportional servo cartridge valve through the system oil port to achieve low-speed injection, or supply oil to the second proportional servo cartridge valve through the first accumulator to achieve high-speed injection, that is, it can freely switch between low-speed injection and high-speed injection, improving applicability; 2. The rodless cavity and the rod cavity of the injection cylinder are separately controlled by the first proportional servo cartridge valve and the second proportional servo cartridge valve. Its hydraulic flow rate is relatively high, which can meet the flow requirements of high-pressure and high-speed injection conditions, and its response time is short and the accuracy is higher; 3. The proportional servo direction control valve is adopted, and the opening size of the main oil circuit is adjustable. Furthermore, it is possible to achieve real-time adjustment of the pressure in the injection cavity of the injection cylinder. Its adjustment accuracy is high and the adjustment speed is fast, thereby improving production efficiency and product quality; 4. During the material storage process of the injection cylinder, the oil returned by the proportional servo direction control valve can enter the rod cavity of the injection cylinder through the oil tank and the second proportional servo cartridge valve to replenish oil for the rod cavity of the injection cylinder, without the need for additional components to replenish oil for material storage, saving costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is the overall oil circuit schematic diagram of the injection system in the prior art; Figure 2 is the overall oil circuit schematic diagram of the injection system of the embodiment.

[0017] In the figure: 1. System oil circuit; 11. System oil port; 12. First cartridge valve; 2. Injection oil circuit; 21. Injection cylinder; 211. First pressure sensor; 212. Second pressure sensor; 213. Injection position gauge; 22. First proportional servo cartridge valve; 221. Fourth electromagnet; 23. Second proportional servo cartridge valve; 231. Fifth electromagnet; 24. Proportional servo direction control valve; 241. Third electromagnet; 25. Oil tank; 26. Third cartridge valve; 27. Third pilot valve; 28. Second shuttle valve; 3. Accumulator oil circuit; 31. First accumulator; 32. Control valve group; 321. Second cartridge valve; 322. First shuttle valve; 323. First pilot valve; 323a. First electromagnet; 324. Second pilot valve; 324a. Second electromagnet; 4. Charge and discharge energy circuit; 41. Charge energy valve group; 42. Discharge energy valve group; 5. Spool type servo valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The following are specific embodiments of the present invention. In combination with the accompanying drawings, the technical solutions of the present invention will be further described, but the invention is not limited to these embodiments.

[0019] As Figure 2 shown, a hydraulic circuit of a new injection system includes a system oil circuit 1, an energy storage oil circuit 3, and an injection oil circuit 2. Among them, the system oil circuit 1 can directly supply oil to the injection oil circuit 2 to achieve the low-speed injection function. The system oil circuit 1 can also store the hydraulic oil through the energy storage oil circuit 3 and then supply it to the injection oil circuit 2 so that it can perform high-speed injection. The injection oil circuit 2 is used to control the injection, material storage, and screw withdrawal and other actions of the injection molding machine.

[0020] Specifically, the system oil circuit 1 includes a system oil port 11, the energy storage oil circuit 3 includes a first accumulator 31, and the injection oil circuit 2 includes an injection cylinder 21, a first proportional servo cartridge valve 22, a second proportional servo cartridge valve 23, a proportional servo direction control valve 24, and a fuel tank 25. The system oil port 11 is simultaneously connected to the first proportional servo cartridge valve 22 and the first accumulator 31. The oil outlet of the first proportional servo cartridge valve 22 is connected to the rodless cavity of the injection cylinder 21. That is, the hydraulic oil provided by the system oil port 11 can directly enter the rodless cavity of the injection cylinder 21 through the first proportional servo cartridge valve 22 to achieve its low-speed injection action. It can also first enter the first accumulator 31 for energy storage, and then the first accumulator 31 refuels the rodless cavity of the injection cylinder 21 through the first proportional servo cartridge valve 22 to achieve its high-speed injection action, meeting different injection requirements. Among them, the rod cavity of the injection cylinder 21 can be connected to the fuel tank 25 through the second proportional servo cartridge valve 23. During the injection process, the hydraulic oil in the rod cavity of the injection cylinder 21 is drained into the fuel tank 25 through the second proportional servo cartridge valve 23. During the material storage process, the proportional servo direction control valve 24 is used to control the material storage back pressure. Since the proportional servo cartridge valve has the characteristics of high flow rate, short step response time, and high frequency response, it can respond faster and with higher precision under high-pressure and high-speed large-flow working conditions.

[0021] When the injection cylinder 21 is in the low-speed injection state, both the first proportional servo cartridge valve 22 and the second proportional servo cartridge valve 23 are opened. The system oil port 11 is connected to the rodless cavity of the injection cylinder 21 through the first proportional servo cartridge valve 22. In this state, the system oil port 11 directly provides hydraulic oil for the rodless cavity of the injection cylinder 21 to achieve low-speed injection. The hydraulic oil in the rod cavity of the injection cylinder 21 can return to the fuel tank 25 through the second proportional servo valve.

[0022] When the injection oil cylinder 21 is in the high-speed injection state, both the first proportional servo cartridge valve 22 and the second proportional servo cartridge valve 23 are opened. The first accumulator 31 is communicated with the rodless cavity of the injection oil cylinder 21 through the first proportional servo cartridge valve 22. At this time, high-pressure oil is released from the first accumulator 31 and enters the rodless cavity of the injection oil cylinder 21 to achieve high-speed injection.

[0023] When the injection oil cylinder 21 is in the material storage state, the rodless cavity of the injection oil cylinder 21 is communicated with the fuel tank 25 through the proportional servo direction control valve 24. The first proportional servo cartridge valve 22 is closed and the second proportional servo cartridge valve 23 is opened. The fuel tank 25 is communicated with the rod cavity of the injection oil cylinder 21 through the second proportional servo cartridge valve 23. In the material storage state, the back pressure of the injection oil cylinder 21 can be adjusted through the proportional servo direction control valve 24, and the rod cavity can be refueled through the fuel tank 25 to meet the demand for small amount of refueling.

[0024] In this embodiment, the flow rate of the proportional servo cartridge valve can reach 1400 L / min, the step response reaches 14 ms, and the frequency response reaches 70 - 90 Hz. While for the large-diameter spool-type servo valve used in the existing injection system, its flow rate can reach 1500 L / min, but its step response time reaches 55 ms and its frequency response is only 30 - 40 Hz.

[0025] To achieve the on-off of the system oil port 11 with the first proportional servo cartridge valve 22 and the first accumulator 31, the system oil circuit 1 further includes a first cartridge valve 12. The oil inlet of the first cartridge valve 12 is communicated with the system oil port 11. The oil outlet of the first cartridge valve 12 is communicated with the oil inlet of the first proportional servo cartridge valve 22 through a first pipeline. The oil port of the first accumulator 31 is communicated with the first pipeline. Then when the first accumulator 31 releases energy, the high-pressure oil in the first pipeline will control the first cartridge valve 12 to close, so that all the high-pressure oil released by the first accumulator 31 goes to the oil inlet of the first proportional servo cartridge valve 22.

[0026] In this embodiment, the accumulator oil circuit 3 further includes a control valve group 32. The control valve group 32 is located between the first pipeline and the first accumulator 31 and is used to control the on-off between the first pipeline and the first accumulator 31. Through the control valve group 32, the control of the charging, discharging, and closing actions of the first accumulator 31 can be realized. When the first cartridge valve 12 is communicated with the first accumulator 31, the system oil port 11 can supply oil to the first accumulator 31 through the first cartridge valve 12. Of course, the first accumulator 31 can also provide high-pressure hydraulic oil for the first proportional servo cartridge valve 22.

[0027] Specifically, the control valve group 32 includes a second cartridge valve 321, a first shuttle valve 322, a first pilot valve 323 and a second pilot valve 324. The second cartridge valve 321 is provided with a first oil port, a second oil port and a control chamber. The first shuttle valve 322 is provided with two third oil ports and a fourth oil port. The two third oil ports are connected to the first oil port and the second oil port respectively. The fourth oil port can be connected to the control chamber through the first pilot valve 323 and the second pilot valve 324. Among them, the first oil port is connected to the first pipeline, and the second oil port is connected to the oil port of the first accumulator 31. The connection and disconnection of the first oil port and the second oil port can be determined by whether oil is supplied to the control chamber.

[0028] In order to realize the control of the charging and discharging energy by the control valve group 32, a first oil inlet, a second oil inlet, a first oil outlet and a first electromagnet 323a are provided on the first pilot valve 323, the first oil inlet is connected to the fourth oil port, and the second oil inlet is connected to one of the third oil ports and the second oil port at the same time. When the first electromagnet 323a is energized, the first oil inlet is connected to the first oil outlet, and when the first electromagnet 323a is de-energized, the second oil inlet is connected to the first oil outlet, and a third oil inlet, a second oil outlet, a first variable oil port and a second electromagnet 324a are provided on the second pilot valve 324, the third oil inlet is connected to the first oil outlet, the second oil outlet is connected to the oil tank 25, and the first variable oil port is connected to the control chamber. When the second electromagnet 324a is energized, the first variable oil port is connected to the second oil outlet, and when the second electromagnet 324a is de-energized, the first variable oil port is connected to the third oil inlet.

[0029] As can be seen from the above, the second cartridge valve 321 has three states: 1. The first electromagnet 323a and the second electromagnet 324a lose power at the same time. At this time, the second oil inlet of the first pilot valve 323 is connected to the first oil outlet, and the third oil inlet of the second pilot valve 324 is connected to the first variable oil port. At this time, the hydraulic oil flowing out of the first cartridge valve 12 can control the second cartridge valve 321 to open in one direction, so as to facilitate the one-way charging action; 2. The first electromagnet 323a is energized and the second electromagnet 324a is de-energized. At this time, the first oil inlet of the first pilot valve 323 is connected to the first oil outlet, and the third oil inlet of the second pilot valve 324 is connected to the first variable oil port. At this time, no matter whether the oil pressure of the first oil port or the second oil port is higher, the hydraulic oil will be transported from the fourth oil port of the first shuttle valve 322 to the control chamber of the second cartridge valve 321. At this time, the second cartridge valve 321 is closed, and the first accumulator 31 is cut off. Third, when the first electromagnet 323a loses power and the second electromagnet 324a is energized, the first variable oil port of the second pilot valve 324 is communicated with the second oil outlet at this time, and the second oil outlet is communicated with the oil tank 25. At this time, the hydraulic oil in the control chamber will enter the oil tank 25 through the second pilot valve 324. Therefore, no matter which side has a higher oil pressure, the second cartridge valve 321 will remain open. Therefore, when the oil pressure on one side of the first accumulator 31 is higher, energy can be released through the first accumulator 31.

[0030] In this embodiment, in order to further improve the safety performance of the first accumulator 31, the energy storage oil circuit 3 further includes a power-off pressure relief valve, a safety valve, and a manual pressure relief valve. The power-off pressure relief valve, the safety valve, and the manual pressure relief valve are all communicated with the first accumulator 31. Among them, the power-off pressure relief valve is used to relieve the pressure of the first accumulator 31 in the case of power-off, the safety valve relieves the pressure when the oil pressure of the first accumulator 31 exceeds the safety threshold, and the manual pressure relief valve is used for manual pressure relief, ensuring from multiple angles that the pressure of the first accumulator 31 is within the normal range, thereby improving the safety performance.

[0031] In this embodiment, in order to adjust the storage back pressure of the injection cylinder 21, the proportional servo direction control valve 24 is provided with a fourth oil inlet, a third oil outlet, and a third electromagnet 241. When the third electromagnet 241 is energized, the fourth oil inlet can be communicated with the third oil outlet, and the third electromagnet 241 can control the opening size between the fourth oil inlet and the third oil outlet. The opening size between the fourth oil inlet and the third oil outlet can be controlled according to the voltage applied to the third electromagnet 241, and its size adjustment can adjust the back pressure.

[0032] In order to improve the injection accuracy, the first proportional servo cartridge valve 22 is provided with a fourth electromagnet 221. When the fourth electromagnet 221 is energized, it can control the first proportional servo cartridge valve 22 to open and control the opening size of the first proportional servo cartridge valve 22. The second proportional servo cartridge valve 23 is provided with a fifth electromagnet 231. When the fifth electromagnet 231 is energized, it can control the second proportional servo cartridge valve 23 to open and control the opening size of the second proportional servo cartridge valve 23. By adjusting the opening size of the first proportional servo cartridge valve 22, the injection hydraulic flow rate of the rodless chamber of the injection cylinder 21 can be controlled. By adjusting the opening size of the second proportional servo cartridge valve 23, the oil return speed of the rod chamber of the injection cylinder 21 can be realized, thereby controlling the injection speed and improving the injection accuracy.

[0033] As can be seen from the above, in this embodiment, the opening sizes of the proportional servo direction control valve 24, the first proportional servo cartridge valve 22, and the second proportional servo cartridge valve 23 are all determined by the magnitude of the applied voltage, and the magnitude of the voltage applied to each electromagnet can be independently controlled by the control system.

[0034] Moreover, in this embodiment, in order to accurately control the back pressure and improve the injection accuracy, the injection oil circuit 2 further includes a first pressure sensor 211, a second pressure sensor 212, and an injection position ruler 213. The first pressure sensor 211 is used to monitor the oil pressure in the rodless cavity of the injection cylinder 21. During the material storage process, the pressure value detected by the first pressure sensor 211 is the back pressure in the rodless cavity of the injection cylinder 21. After the first pressure sensor 211 monitors the pressure value, it feeds back to the control system of the injection molding machine, and the control system determines whether it meets the back pressure requirements. If it meets the requirements, it works normally; if it does not meet the requirements, it controls the opening size of the proportional servo direction control valve 24 to play a regulating role. The second pressure sensor is used to monitor the oil pressure in the rod chamber of the injection cylinder 21, and the injection position ruler 213 is used to monitor the position of the piston rod of the injection cylinder 21. The three can be combined to perform closed-loop control of the injection cylinder 21.

[0035] In order to make the injection cylinder 21 perform a retraction action, the injection oil circuit 2 further includes a third cartridge valve 26, a third pilot valve 27, and a second shuttle valve 28. The oil inlet of the third cartridge valve 26 is communicated with the system oil port 11, and the oil outlet of the third cartridge valve 26 is communicated with the rod chamber of the injection cylinder 21. The third pilot valve 27 can control the third cartridge valve 26 to open or close through the second shuttle valve 28. When the third pilot valve 27 loses power, any high-pressure oil at the oil inlet or outlet of the third cartridge valve 26 will close the third cartridge valve 26 through the second shuttle valve 28. When the third pilot valve 27 is powered on, the control oil of the third cartridge valve 26 will only be communicated with the oil outlet, playing a one-way role. At this time, the hydraulic oil at the system oil port 11 can enter the rod chamber of the injection cylinder 21 through the third cartridge valve 26, and the hydraulic oil in the rodless cavity of the injection cylinder 21 will return to the oil tank through the proportional servo direction control valve 24. Of course, when retracting, the first proportional servo cartridge valve 22 and the second proportional servo cartridge valve 23 are both in the closed state to complete the retraction action.

[0036] The technical solutions of the present invention have been described in detail above in conjunction with the accompanying drawings. The described embodiments are used to help understand the idea of the present invention. The specific embodiments described herein are only illustrative examples of the spirit of the present invention. Those skilled in the art in the technical field to which the invention pertains can make various modifications or supplements to the described specific embodiments or use similar methods to replace them, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0037] It should be noted that all directional indicators (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If this specific posture changes, the directional indicators will also change accordingly.

[0038] In addition, in the present invention, descriptions such as "first", "second", "one", etc. are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0039] In the present invention, unless otherwise clearly defined and limited, terms such as "connection" and "fixation" shall be understood in a broad sense. For example, "fixation" may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] In addition, the technical solutions between various embodiments of the present invention can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

Claims

1. A hydraulic circuit of a new injection system, characterized in that, It includes a system oil circuit, an energy storage oil circuit, and an injection oil circuit. The system oil circuit includes a system oil port. The energy storage oil circuit includes a first accumulator. The injection oil circuit includes an injection cylinder, a first proportional servo cartridge valve, a second proportional servo cartridge valve, a proportional servo direction control valve, and a fuel tank. The system oil port is simultaneously connected to the first proportional servo cartridge valve and the first accumulator. The oil outlet of the first proportional servo cartridge valve is connected to the rodless cavity of the injection cylinder. The rod chamber of the injection cylinder can be connected to the fuel tank through the second proportional servo cartridge valve. The proportional servo direction control valve is located between the rodless cavity of the injection cylinder and the fuel tank; When the injection cylinder is in the low-speed injection state, both the first proportional servo cartridge valve and the second proportional servo cartridge valve are opened, and the system oil port is connected to the rodless cavity of the injection cylinder through the first proportional servo cartridge valve; When the injection cylinder is in the high-speed injection state, both the first proportional servo cartridge valve and the second proportional servo cartridge valve are opened, and the first accumulator is connected to the rodless cavity of the injection cylinder through the first proportional servo cartridge valve; When the injection cylinder is in the material storage state, the rodless cavity of the injection cylinder is connected to the fuel tank through the proportional servo direction control valve. The first proportional servo cartridge valve is closed and the second proportional servo cartridge valve is opened. The fuel tank is connected to the rod chamber of the injection cylinder through the second proportional servo cartridge valve.

2. A hydraulic circuit of a novel injection system according to claim 1, characterized in that, The system oil circuit further includes a first cartridge valve. The oil inlet of the first cartridge valve is connected to the system oil port. The oil outlet of the first cartridge valve is connected to the oil inlet of the first proportional servo cartridge valve through a first pipeline. The oil port of the first accumulator is connected to the first pipeline.

3. A hydraulic circuit of a novel injection system according to claim 2, characterized in that, The energy storage oil circuit further includes a control valve group. The control valve group is located between the first pipeline and the first accumulator and is used to control the on-off between the first pipeline and the first accumulator.

4. A novel injection system hydraulic circuit according to claim 3, characterized in that, The control valve group includes a second cartridge valve, a first shuttle valve, a first pilot valve, and a second pilot valve. The second cartridge valve is provided with a first oil port, a second oil port, and a control chamber. The first shuttle valve is provided with two third oil ports and a fourth oil port. Both of the two third oil ports are respectively connected to the first oil port and the second oil port. The fourth oil port can be connected to the control chamber through the first pilot valve and the second pilot valve.

5. A hydraulic circuit of a novel injection system according to claim 4, characterized in that, The first pilot valve is provided with a first oil inlet, a second oil inlet, a first oil outlet, and a first electromagnet. The first oil inlet is connected to the fourth oil port. The second oil inlet is simultaneously connected to one of the third oil ports and the second oil port. When the first electromagnet is energized, the first oil inlet is connected to the first oil outlet. When the first electromagnet is de-energized, the second oil inlet is connected to the first oil outlet; The second pilot valve is provided with a third oil inlet, a second oil outlet, a first variable oil port and a second electromagnet. The third oil inlet is communicated with the first oil outlet. The second oil outlet is communicated with the oil tank. The first variable oil port is communicated with the control chamber. When the second electromagnet is energized, the first variable oil port is communicated with the second oil outlet. When the second electromagnet is de-energized, the first variable oil port is communicated with the third oil inlet.

6. A hydraulic circuit of a novel injection system according to claim 1, characterized in that, The proportional servo direction control valve is provided with a fourth oil inlet, a third oil outlet and a third electromagnet. When the third electromagnet is energized, the fourth oil inlet can be communicated with the third oil outlet, and the third electromagnet can control the opening size between the fourth oil inlet and the third oil outlet.

7. A hydraulic circuit of a novel injection system according to claim 6, characterized in that, The first proportional servo cartridge valve is provided with a fourth electromagnet. When the fourth electromagnet is energized, it can control the first proportional servo cartridge valve to open and can control the opening size of the first proportional servo cartridge valve.

8. A hydraulic circuit of a novel injection system according to claim 6, characterized in that, The second proportional servo cartridge valve is provided with a fifth electromagnet. When the fifth electromagnet is energized, it can control the second proportional servo cartridge valve to open and can control the opening size of the second proportional servo cartridge valve.

9. A hydraulic circuit of a novel injection system according to claim 1, characterized in that, The injection oil circuit further includes a third cartridge valve, a third pilot valve and a second shuttle valve. The oil inlet of the third cartridge valve is communicated with the system oil port. The oil outlet of the third cartridge valve is communicated with the rod chamber of the injection cylinder. The third pilot valve can control the third cartridge valve to open or close through the second shuttle valve.

10. A hydraulic circuit of a novel injection system according to claim 1, characterized in that, The injection oil circuit further includes a first pressure sensor, a second pressure sensor and an injection position gauge. The first pressure sensor is used to monitor the oil pressure in the rodless chamber of the injection cylinder. The second pressure sensor is used to monitor the oil pressure in the rod chamber of the injection cylinder. The injection position gauge is used to monitor the position of the piston rod of the injection cylinder.

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