A reduced pressure hydraulic station system and injection molding machine

Abstract

The utility model belongs to injection molding machine technical field provides a kind of pressure reducing hydraulic station system and injection molding machine, and hydraulic station system includes: oil tank, motor, hydraulic pump, check valve, pressure regulating valve, first pressure reducing valve, switch valve, working oil cylinder, safety overflow valve, cooler, solenoid valve and nitrogen cylinder;Motor drives and connects hydraulic pump, the import of hydraulic pump is communicated oil tank, and export is connected the import of first pressure reducing valve by check valve;The export of first pressure reducing valve is connected working oil cylinder by switch valve;The import of safety overflow valve is connected on the pipeline of check valve import side, and export is communicated oil tank by cooler;Solenoid valve controls the opening and closing of safety overflow valve;Nitrogen cylinder is connected on the oil circuit between first pressure reducing valve and check valve oil outlet by pipeline.Compared with prior art, the utility model is integrated nitrogen cylinder energy storage and pressure reducing control mechanism, effectively solve the problem of traditional hydraulic station energy waste, response lag and unstable pressure.

Description

Technical Field

[0001] This utility model belongs to the field of injection molding machine technology, specifically relating to a pressure-reducing hydraulic station system and an injection molding machine. Background Technology

[0002] Hydraulic systems are widely used in industrial automation, construction machinery, metallurgical equipment, and other fields. One of their core components is the hydraulic pump station. Traditional hydraulic pump stations typically use an electric motor to drive a hydraulic pump that draws oil from the tank and delivers pressurized oil to the actuators (such as hydraulic cylinders) to drive the load. To ensure system safety, a relief valve is generally installed as a safety protection device. When the system pressure exceeds the set value, the excess oil is directly discharged back to the tank.

[0003] However, existing hydraulic power station systems still have some shortcomings in actual operation. First, when the system is not in operation or under light load, the hydraulic pump outputs a large amount of oil that is often discharged back to the tank through the relief valve, which not only wastes energy but also causes the hydraulic oil temperature to rise, affecting system efficiency and stability. Second, when the system requires a large instantaneous flow of oil, relying solely on the hydraulic pump may result in a slow response, affecting the speed and accuracy of the actuators. In addition, traditional systems lack effective energy storage and pressure compensation mechanisms, making it difficult to cope with load fluctuations and resulting in poor system pressure stability.

[0004] To address these issues, some systems have incorporated accumulators for energy recovery and pressure compensation. However, conventional accumulators often employ spring-type or pneumatic bladder structures, which suffer from slow response times, low energy storage efficiency, and performance degradation due to the soluble nature of gas in oil. Therefore, a novel hydraulic power station system is urgently needed that can effectively reduce energy consumption, improve response speed, and enhance system pressure stability. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a pressure-reducing hydraulic station system and an injection molding machine in light of the current state of the technology.

[0006] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: a pressure-reducing hydraulic station system is proposed, including: an oil tank, a motor, a hydraulic pump, a check valve, a pressure regulating valve, a first pressure reducing valve, a switching valve, a working oil cylinder, a safety relief valve, a cooler, a solenoid directional valve, and a nitrogen cylinder.

[0007] The motor drives the hydraulic pump, the inlet of the hydraulic pump is connected to the oil tank, and the outlet is connected to the inlet of the first pressure reducing valve through the check valve. The first pressure reducing valve is used to reduce the pressure of the oil to a set pressure.

[0008] The outlet of the first pressure reducing valve is connected to the working cylinder through the switching valve;

[0009] The inlet of the safety relief valve is connected to the pipeline on the inlet side of the check valve, and the outlet is connected to the oil tank through the cooler, which is used to safely relieve pressure when the system pressure exceeds the set value;

[0010] The electromagnetic reversing valve controls the opening and closing of the safety relief valve. When the system does not require oil supply, the electromagnetic reversing valve is de-energized, causing the safety relief valve to open to release the load pressure in the working pipeline.

[0011] The nitrogen cylinder is connected via a pipeline to the oil line between the first pressure reducing valve and the oil outlet of the one-way valve. It is used to store pressure oil when there is excess pressure oil in the system and to release the stored oil to supplement the system's needs when there is insufficient pressure oil.

[0012] In the aforementioned pressure-reducing hydraulic station system, the nitrogen cylinder is equipped with an elastic diaphragm or piston structure to isolate nitrogen from hydraulic oil and prevent the gas from dissolving in the oil.

[0013] In the aforementioned pressure-reducing hydraulic station system, the cooler is installed on the return oil pipeline between the safety relief valve and the oil tank to cool down the high-temperature hydraulic oil that is drained back.

[0014] The aforementioned pressure-reducing hydraulic station system also includes a pressure gauge and a pressure sensor. The pressure gauge is installed on the outlet side pipeline of the switching valve, and the pressure sensor is installed on the inlet pipeline of the nitrogen cylinder for real-time monitoring of the system's operating pressure.

[0015] In the aforementioned pressure-reducing hydraulic station system, the switching valve is an electrically controlled ball valve or a solenoid valve, used to control the supply of oil to the working cylinder or to cut off the oil circuit according to the work command.

[0016] In the aforementioned pressure-reducing hydraulic station system, an oil suction filter is installed between the hydraulic pump and the oil tank.

[0017] In the aforementioned pressure-reducing hydraulic station system, a second pressure-reducing valve is provided between the cooler and the oil tank.

[0018] In the aforementioned pressure-reducing hydraulic station system, an oil drain valve is provided between the nitrogen cylinder and the oil tank.

[0019] This utility model solves the above-mentioned technical problems and also proposes an injection molding machine, including the aforementioned pressure-reducing hydraulic station system.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) By integrating the nitrogen cylinder energy storage and pressure reduction control mechanism, the problems of energy waste, response lag and pressure instability of traditional hydraulic stations are effectively solved. When the system is working normally, the first pressure reducing valve reduces the high pressure oil output by the pump to the set pressure to supply the working cylinder. When the system has excess oil supply, the excess oil is stored in the nitrogen cylinder, avoiding energy loss and oil temperature rise caused by long-term pressure relief through the safety relief valve. When the system's instantaneous oil demand increases, the nitrogen cylinder quickly releases the stored oil to replenish it, significantly improving the dynamic response speed and oil supply stability of the system.

[0022] (2) An elastic diaphragm or piston structure is installed inside the nitrogen cylinder to achieve physical isolation between nitrogen and hydraulic oil. This effectively prevents problems such as oil cavitation, increased compressibility, decreased energy storage efficiency and unstable system operation caused by high-pressure nitrogen dissolving in the oil. It ensures the reliability of the nitrogen cylinder in long-term operation and the stability of its energy storage performance, and improves the durability and control accuracy of the entire hydraulic system.

[0023] (3) The cooler is installed on the return oil line between the safety relief valve and the oil tank. It can cool the high temperature oil generated by safety pressure relief or system unloading in a timely and effective manner before returning it to the oil tank. This avoids the oil deterioration, aging of seals and reduction of system efficiency caused by the continuous accumulation and rise of oil temperature. It solves the technical problem of excessive oil temperature in traditional systems and extends the service life of hydraulic oil and key components. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a pressure-reducing hydraulic station system according to this utility model.

[0025] In the diagram, 1. Oil tank; 2. Liquid level / temperature gauge; 3. Suction filter; 4. Motor; 5. Hydraulic pump; 6. Cooler; 7. Air filter; 8. Switch valve; 9. Pressure gauge; 10. Drain screw; 11. Check valve; 12. Pressure regulating valve; 13. Manifold block; 14. Safety relief valve; 15. Solenoid directional valve; 16. Drain valve; 17. Nitrogen cylinder; 18. Pressure sensor; 19. First pressure reducing valve; 20. Second pressure reducing valve. Detailed Implementation

[0026] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0027] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0028] like Figure 1 As shown, a pressure-reducing hydraulic station system of this utility model includes: an oil tank 1, a motor 4, a hydraulic pump 5, a one-way valve 11, a pressure regulating valve 12, a first pressure reducing valve 19, a switching valve 8, a working oil cylinder, a safety relief valve 14, a cooler 6, a solenoid directional valve 15, and a nitrogen cylinder 17.

[0029] Specifically, the motor 4 drives the hydraulic pump 5, the inlet of the hydraulic pump 5 is connected to the oil tank 1, and the outlet is connected to the inlet of the first pressure reducing valve 19 through the check valve 11. The first pressure reducing valve 19 is used to reduce the pressure of the oil to the set pressure.

[0030] The outlet of the first pressure reducing valve 19 is connected to the working oil cylinder through the switching valve 8;

[0031] The inlet of the safety relief valve 14 is connected to the pipeline on the inlet side of the check valve 11, and the outlet is connected to the oil tank 1 through the cooler 6. It is used to safely relieve pressure when the system pressure exceeds the set value.

[0032] The solenoid directional valve 15 controls the opening and closing of the safety relief valve 14. When the system does not require oil supply, the solenoid directional valve 15 is de-energized, causing the safety relief valve 14 to open and release the load pressure in the working pipeline.

[0033] Nitrogen cylinder 17 is connected to the oil line between the first pressure reducing valve 19 and the oil outlet of the one-way valve 11 via a pipeline. It is used to store pressure oil when there is excess pressure oil in the system and to release the stored oil to supplement the system demand when there is insufficient pressure oil.

[0034] This invention effectively solves the problems of energy waste, slow response, and unstable pressure in traditional hydraulic stations by integrating a nitrogen cylinder 17 for energy storage and pressure reduction control. During normal system operation, the first pressure reducing valve 19 reduces the high-pressure oil output from the pump to a set pressure to supply the working cylinder. When the system has excess oil supply, the excess oil is stored in the nitrogen cylinder 17, avoiding energy loss and oil temperature rise caused by long-term pressure relief through the safety relief valve 14. When the system's instantaneous oil demand increases, the nitrogen cylinder 17 quickly releases the stored oil to replenish it, significantly improving the system's dynamic response speed and oil supply stability. Simultaneously, the electromagnetic directional valve 15 controls the opening and closing of the safety relief valve 14, allowing the system to be completely unloaded when not in operation, further achieving energy saving and consumption reduction.

[0035] It is worth mentioning that the nitrogen cylinder 17 is equipped with an elastic diaphragm or piston structure to isolate nitrogen from hydraulic oil and prevent the gas from dissolving in the oil.

[0036] The nitrogen cylinder 17 is equipped with an elastic diaphragm or piston structure, which achieves physical isolation between nitrogen and hydraulic oil. This effectively prevents problems such as oil cavitation, increased compressibility, decreased energy storage efficiency, and unstable system operation caused by high-pressure nitrogen dissolving in the oil. It ensures the long-term reliability of the nitrogen cylinder 17 and the stability of its energy storage performance, and improves the durability and control accuracy of the entire hydraulic system.

[0037] Furthermore, a cooler 6 is installed on the return oil line between the safety relief valve 14 and the oil tank 1 to cool down the high-temperature hydraulic oil that leaks back.

[0038] The cooler 6 is installed on the return oil line between the safety relief valve 14 and the oil tank 1. It can cool down the high temperature oil generated by safety pressure relief or system unloading in a timely and effective manner before returning it to the oil tank 1. This avoids the oil deterioration, seal aging and system efficiency reduction caused by the continuous accumulation and rise of oil temperature. It solves the technical problem of excessive oil temperature in traditional systems and extends the service life of hydraulic oil and key components.

[0039] This solution also includes a pressure gauge 9 and a pressure sensor 18. The pressure gauge 9 is installed on the outlet side pipeline of the switch valve 8, and the pressure sensor 18 is installed on the oil inlet pipeline of the nitrogen cylinder 17 for real-time monitoring of the system working pressure.

[0040] By installing a pressure gauge 9 at the outlet of the switching valve 8 and a pressure sensor 18 in the oil inlet line of the nitrogen cylinder 17, the inlet pressure of the working cylinder and the energy storage pressure of the nitrogen cylinder 17 can be monitored in real time and accurately. This not only allows operators to intuitively grasp the system's operating status and promptly detect abnormalities, but also provides reliable data support for the system's automated control and fault early warning, significantly improving the system's maintainability and operational safety.

[0041] Preferably, the switching valve 8 is an electrically controlled ball valve or a solenoid valve, used to control the supply of oil to the working cylinder or to cut off the oil circuit according to the working command.

[0042] The switching valve 8 adopts an electrically controlled ball valve or a solenoid valve, which has the advantages of fast response speed, high control accuracy and reliable operation. It can realize the rapid opening and cutting off of the oil circuit according to the work command, ensuring the timely and accurate action of the working oil cylinder, meeting the requirements of high dynamic performance of hydraulic system under complex working conditions, and improving the automation level and production efficiency of the equipment.

[0043] An oil suction filter 3 is installed between the hydraulic pump 5 and the oil tank 1.

[0044] An oil suction filter 3 is installed on the oil suction line between the hydraulic pump 5 and the oil tank 1. This effectively intercepts particulate impurities in the oil tank 1, preventing them from entering the hydraulic pump 5 and causing wear, jamming, or damage. This protects the core power components of the system, improves the cleanliness and operational reliability of the system, reduces the failure rate, and extends the maintenance cycle and overall service life of the equipment.

[0045] A second pressure reducing valve 20 is provided between the cooler 6 and the oil tank 1.

[0046] A second pressure reducing valve 20 is added between the cooler 6 and the oil tank 1. This valve can perform secondary pressure regulation on the return oil after it has been cooled by the cooler 6, ensuring that the return oil enters the oil tank 1 in a stable and low-pressure state. This avoids return oil impact and oil splashing, and is conducive to the precipitation and sedimentation of air bubbles in the oil, further improving the cleanliness of the oil and the stability of the system. At the same time, it reduces the noise and vibration of the oil tank 1.

[0047] An oil drain valve 16 is provided between the nitrogen cylinder 17 and the oil tank 1.

[0048] An oil drain valve 16 is installed between nitrogen cylinder 17 and oil tank 1, providing a safe and controllable maintenance channel for the system. During equipment maintenance, replacement of nitrogen cylinder 17, or system debugging, the high-pressure oil stored in nitrogen cylinder 17 can be safely drained back to oil tank 1 by opening the oil drain valve 16, realizing safe evacuation and pressure release of the system. This ensures the operational safety of maintenance personnel, simplifies the maintenance process, and is an important part of the system's safety design.

[0049] This solution also includes a level and temperature gauge 2, an air filter 7, and a drain plug 10 installed on the oil tank 1, as well as an oil manifold block 13. The level and temperature gauge 2 is used to monitor the hydraulic oil level and temperature in the oil tank 1 in real time; the air filter 7 is installed on the top of the oil tank 1 to filter the air entering the oil tank 1 and to discharge the gas inside the oil tank 1, preventing contaminants from entering the system with the air; the drain plug 10 is located at the bottom of the oil tank 1 to drain the oil in the oil tank 1 when changing the hydraulic oil; the oil manifold block 13 serves as an integrated installation platform, carrying and connecting the check valve 11, the pressure regulating valve 12, the safety relief valve 14, the solenoid directional valve 15, the drain valve 16, and the first pressure reducing valve 19, achieving a compact layout and efficient connection of the pipelines.

[0050] This solution also proposes an injection molding machine, including the aforementioned pressure-reducing hydraulic station system.

[0051] The specific working process of the pressure-reducing hydraulic station system in this solution is as follows:

[0052] 1. Oil flow path during normal operation of the system hydraulic system

[0053] When the system is in normal working condition and supplies hydraulic oil at a set pressure to the working cylinder, the oil flow path is as follows:

[0054] Motor 4 starts and drives hydraulic pump 5 to draw oil from oil tank 1. The high-pressure oil output by hydraulic pump 5 first undergoes preliminary purification through suction filter 3, and then passes through check valve 11 to prevent backflow. The oil continues to flow through pressure regulating valve 12, which sets the maximum pressure at the pump outlet, serving as primary pressure control. Subsequently, the oil enters first pressure reducing valve 19, which reduces the high-pressure oil to the set pressure required by the working cylinder. The pressure-reduced oil then enters the working cylinder through switch valve 8, which is now in the open state, pushing the piston to move and complete the predetermined mechanical action. At the same time, nitrogen cylinder 17 is connected to the oil circuit between first pressure reducing valve 19 and switch valve 8 via connecting pipeline. When the system's oil supply and demand are basically balanced, nitrogen cylinder 17 neither draws nor releases oil, remaining in a standby state, with its internal nitrogen pressure maintaining dynamic balance with the system's working pressure.

[0055] 2. When the system hydraulic pressure is too high, the oil flow path...

[0056] When the system pressure exceeds the safety setpoint due to a sudden increase in load or control failure, the oil flow path is as follows to protect the system:

[0057] Hydraulic pump 5 continuously outputs high-pressure oil, which continues to increase in pressure after passing through check valve 11 and pressure regulating valve 12. When the pressure in this pipeline exceeds the set opening pressure of safety relief valve 14, safety relief valve 14 is opened. At this time, the high-pressure oil no longer flows entirely to the first pressure reducing valve 19, but a portion or all of it is discharged through the opened safety relief valve 14, depending on the load. The discharged high-pressure oil then flows through cooler 6, where it undergoes heat exchange, its temperature decreases, and finally flows back to oil tank 1. The oil pressure after the first pressure reducing valve 19 is maintained at the set value by the pressure reducing valve itself, so the working cylinder can still obtain oil with stable pressure, while the overpressure portion at the pump outlet is safely released through the relief circuit. At this time, due to the excessively high pressure at the front end, the nitrogen gas inside nitrogen cylinder 17 is compressed, which can absorb a small amount of instantaneous high-pressure oil, playing a certain buffering role.

[0058] 3. When the system hydraulic pressure is too low or no oil supply is required, the oil flow path...

[0059] When the system completes its working cycle and the hydraulic cylinder does not need to move, or when the system needs to unload to save energy, the hydraulic fluid's path is as follows:

[0060] When the electromagnetic directional valve 15 loses power, its control oil circuit activates, causing pressure to be released at the remote control port of the safety relief valve 14. This causes the safety relief valve 14 to open, effectively "disabling" its pressure relief state. At this time, all the high-pressure oil output from the hydraulic pump 5, after passing through the check valve 11, no longer flows to the first pressure reducing valve 1919, but instead is directly discharged back through the opened safety relief valve 14. The oil flows back to the oil tank 1 after being cooled by the cooler 6. Because the safety relief valve 14 is open, the pump outlet pressure is maintained at a very low level, close to zero, achieving low-pressure unloading of the system, reducing the load on the motor 4, and achieving energy saving. At this time, the pressure before and after the first pressure reducing valve 19 is very low, and no oil flows through it. More importantly, when the working cylinder experiences a pressure drop in the rear oil circuit due to leakage or a small load, the compressed nitrogen in the nitrogen cylinder 17 expands, pushing out the stored hydraulic oil and replenishing it through the pipeline to the oil circuit between the first pressure reducing valve 19 and the check valve 11, maintaining the pressure stability of this section of the oil circuit and preventing the actuator from "creeping" or becoming inaccurately positioned due to a pressure drop.

[0061] This system achieves precise control of the working pressure through the first pressure reducing valve 19, realizes system safety protection and energy-saving unloading through the linkage of the safety relief valve 14 and the solenoid directional valve 15, and realizes energy recovery, storage and pressure compensation through the nitrogen cylinder 17. The oil circuit switching under these three operating conditions reflects the comprehensive optimization design of the system in terms of safety, energy saving and stability.

[0062] It should be noted that in this utility model, the use of terms such as "first," "second," and "a" is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly defined. The terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise explicitly defined. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0063] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0064] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A pressure-reducing hydraulic station system, characterized in that, include: Oil tank (1), motor (4), hydraulic pump (5), check valve (11), pressure regulating valve (12), first pressure reducing valve (19), switch valve (8), working cylinder, safety relief valve (14), cooler (6), solenoid directional valve (15) and nitrogen cylinder (17); The motor (4) drives the hydraulic pump (5), the inlet of the hydraulic pump (5) is connected to the oil tank (1), and the outlet is connected to the inlet of the first pressure reducing valve (19) through the check valve (11). The first pressure reducing valve (19) is used to reduce the pressure of the oil to a set pressure. The outlet of the first pressure reducing valve (19) is connected to the working cylinder through the switching valve (8); The inlet of the safety relief valve (14) is connected to the pipeline on the inlet side of the check valve (11), and the outlet is connected to the oil tank (1) through the cooler (6) for safe pressure relief when the system pressure exceeds the set value; The electromagnetic reversing valve (15) controls the opening and closing of the safety relief valve (14). When the system does not need to supply oil, the electromagnetic reversing valve (15) is de-energized, causing the safety relief valve (14) to open, so as to release the load pressure in the working pipeline. The nitrogen cylinder (17) is connected to the oil line between the first pressure reducing valve (19) and the oil outlet of the one-way valve (11) via a pipeline. It is used to store pressure oil when there is excess pressure oil in the system and to release the stored oil to supplement the system demand when there is insufficient pressure oil.

2. The pressure-reducing hydraulic station system as described in claim 1, characterized in that, The nitrogen cylinder (17) is equipped with an elastic diaphragm or piston structure to isolate nitrogen from hydraulic oil and prevent the gas from dissolving in the oil.

3. The pressure-reducing hydraulic station system as described in claim 1, characterized in that, The cooler (6) is installed on the return oil line between the safety relief valve (14) and the oil tank (1) to cool down the high-temperature hydraulic oil that is drained back.

4. The pressure-reducing hydraulic station system as described in claim 1, characterized in that, It also includes a pressure gauge (9) and a pressure sensor (18). The pressure gauge (9) is installed on the outlet side pipeline of the switch valve (8), and the pressure sensor (18) is installed on the oil inlet pipeline of the nitrogen cylinder (17) for real-time monitoring of the system working pressure.

5. A pressure-reducing hydraulic station system as described in claim 1, characterized in that, The switching valve (8) is an electrically controlled ball valve or a solenoid valve, used to control the supply of oil to the working cylinder or to cut off the oil circuit according to the working command.

6. The pressure-reducing hydraulic station system as described in claim 1, characterized in that, An oil suction filter (3) is provided between the hydraulic pump (5) and the oil tank (1).

7. A pressure-reducing hydraulic station system as described in claim 1, characterized in that, A second pressure reducing valve (20) is provided between the cooler (6) and the oil tank (1).

8. A pressure-reducing hydraulic station system as described in claim 1, characterized in that, An oil drain valve (16) is provided between the nitrogen cylinder (17) and the oil tank (1).

9. An injection molding machine, characterized in that, Includes a pressure-reducing hydraulic station system as described in any one of claims 1 to 8.

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