Injection molding machine hydraulic system and injection molding machine

Abstract

The utility model belongs to injection molding machine technical field discloses an injection molding machine hydraulic system and injection molding machine. The injection molding machine hydraulic system includes: oil tank, first gear pump, second gear pump, servo motor and output oil circuit, the oil tank is used for storing oil liquid, the oil suction pipe of first gear pump and the oil suction pipe of second gear pump are all below the oil liquid level of oil tank, first gear pump and second gear pump are connected in series, and first gear pump and second gear pump are provided with first check valve between, servo motor is connected with first gear pump and second gear pump, and servo motor can drive first gear pump and second gear pump to run, the first end of output oil circuit is connected with the oil outlet of first gear pump and / or second gear pump, and the second end of output oil circuit is used for connecting with the oil inlet end of injection molding machine. The injection molding machine hydraulic system and injection molding machine simple structure, low energy consumption, low in cost, system response is fast, and control precision is high.

Description

Technical Field

[0001] This utility model relates to the field of injection molding machine technology, and in particular to an injection molding machine hydraulic system and an injection molding machine. Background Technology

[0002] As a core piece of equipment in modern manufacturing, the production efficiency and product quality of injection molding machines directly impact a company's competitiveness. The flow rate of the injection molding machine's hydraulic system is a crucial control parameter for ensuring its smooth operation. The flow rate of the injection molding machine's hydraulic system is primarily related to the pump's displacement and the motor's speed.

[0003] To ensure the hydraulic system of an injection molding machine reaches the required flow rate, related technologies rely on two or more servo motors driving two or more large-displacement gear pumps to provide power to the system. However, using multiple servo motors to drive multiple large-displacement gear pumps presents problems such as complex hydraulic system structure, high energy consumption, and high cost. Furthermore, the large inertia of the large-displacement gear pumps leads to slow system response and relatively reduced control accuracy. Utility Model Content

[0004] The purpose of this utility model is to provide a hydraulic system for an injection molding machine and an injection molding machine in which the hydraulic system and injection molding machine have a simple structure, low energy consumption, low cost, fast system response, and high control precision.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] On the one hand, a hydraulic system for an injection molding machine is provided, comprising:

[0007] Fuel tanks are used to store oil.

[0008] The first gear pump and the second gear pump are connected in series. The first gear pump and the second gear pump are connected in series. A first check valve is installed between the first gear pump and the second gear pump.

[0009] A servo motor is connected to the first gear pump and the second gear pump, and the servo motor can drive the first gear pump and the second gear pump to operate.

[0010] The output oil circuit has its first end connected to the oil outlet of the first gear pump and / or the second gear pump, and its second end connected to the oil inlet of the injection molding machine.

[0011] Preferably, the hydraulic system of the injection molding machine further includes a first damper and a first cartridge valve, which are sequentially connected between the first gear pump and the second end of the output oil circuit.

[0012] Preferably, the servo motor is connected to the second gear pump, and a first oil circuit is provided between the second gear pump and the oil tank, with a directional valve provided on the first oil circuit.

[0013] Preferably, the first oil circuit also includes a relief valve and a directional valve, with the input end of the directional valve connected to the input end of the relief valve, and the output ends of both the directional valve and the relief valve connected to the oil tank.

[0014] Preferably, the hydraulic system of the injection molding machine further includes a second oil circuit, which includes a second damper and a second cartridge valve connected in sequence. One end of the second oil circuit is connected between the first gear pump and the first check valve, and the other end of the second oil circuit is connected to the first oil circuit.

[0015] Preferably, the hydraulic system of the injection molding machine further includes a third oil circuit, one end of which is connected to the second end of the output oil circuit, and the other end of which is connected to the oil tank. The third oil circuit includes an accumulator, a second check valve, and a proportional relief valve. One end of the second check valve is connected to the second end of the output oil circuit, and the other end of the second check valve is connected to the accumulator. The proportional relief valve is connected between the second end of the output oil circuit and the oil tank.

[0016] Preferably, a pressure sensor is connected to the first end of the output oil circuit. The pressure sensor is used to detect the pressure at the oil outlet of the one that is furthest from the servo motor, which is the first gear pump or the second gear pump.

[0017] Preferably, the hydraulic system of the injection molding machine further includes a first suction filter and a second suction filter, wherein the first suction filter is installed between the first gear pump and the oil tank, and the second suction filter is installed between the second gear pump and the oil tank.

[0018] Preferably, the maximum speed of the servo motor is greater than or equal to 3000 r / min.

[0019] On the other hand, an injection molding machine is provided, which includes a body and an injection molding machine hydraulic system according to any of the above technical solutions. The body is provided with an oil inlet end, which is connected to the second end of the output oil circuit of the injection molding machine hydraulic system.

[0020] The beneficial effects of this utility model are as follows:

[0021] A hydraulic system and an injection molding machine are provided. The hydraulic system incorporates a first gear pump and a second gear pump. The suction pipes of both the first and second gear pumps are located below the oil level in the oil tank. The first and second gear pumps are connected in series and connected by a first check valve. Both pumps are driven by the same servo motor, simplifying the hydraulic system structure and reducing manufacturing costs. When the injection molding machine operates under low pressure and high flow conditions, the servo motor drives both pumps. The second gear pump supplies oil in coordination with the check valve through a series oil circuit, resulting in flow superposition and achieving the effect of a large-displacement pump. When high pressure and low flow conditions are required, individual gear pumps can be controlled to reduce energy consumption. The check valve prevents backflow of oil from the first gear pump into the second gear pump, thus preventing damage and ensuring the reliability of the injection molding machine's hydraulic system. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the hydraulic system of the injection molding machine provided by this utility model.

[0023] In the diagram: 1. Oil tank; 2. First suction filter; 3. Second suction filter; 4. First gear pump; 5. Second gear pump; 6. Servo motor; 7. First check valve; 8. Directional valve; 9. Pressure sensor; 10. First cartridge valve; 11. Second cartridge valve; 12. Relief valve; 13. Directional valve; 14. First damper; 15. Second damper; 16. Second check valve; 17. Accumulator; 18. Proportional relief valve. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0025] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0026] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0027] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0028] On the one hand, please refer to Figure 1 This embodiment provides a hydraulic system for an injection molding machine, including: an oil tank 1, a first gear pump 4, a second gear pump 5, a servo motor 6, and an output oil circuit. The oil tank 1 is used to store oil. The oil suction pipes of the first gear pump 4 and the second gear pump 5 are both located below the oil level in the oil tank 1. The first gear pump 4 and the second gear pump 5 are connected in series, and a first check valve 7 is provided between the first gear pump 4 and the second gear pump 5. The servo motor 6 is connected to one of the first gear pump 4 and the second gear pump 5, and the servo motor 6 can drive the first gear pump 4 and / or the second gear pump 5 to operate. The first end of the output oil circuit is connected to the oil outlet of the one of the first gear pump 4 and the second gear pump 5 that is away from the servo motor 6, and the second end of the output oil circuit is used to connect to the oil inlet of the injection molding machine.

[0029] With this configuration, the first gear pump 4 and the second gear pump 5 are driven by the same servo motor 6, which simplifies the hydraulic system structure and reduces the manufacturing cost of the hydraulic system. When the injection molding machine is in a low-pressure, high-flow condition, the servo motor 6 drives the first gear pump 4, and the second gear pump 5 supplies oil in coordination with the check valve through a series oil circuit, so that the flow is superimposed to achieve the effect of a large-displacement pump. When a high-pressure, low-flow condition is required, a single gear pump can be controlled to reduce energy consumption.

[0030] Specifically, the servo motor 6 is connected to the second gear pump 5. By setting the first check valve 7, the backflow of oil from the first gear pump 4 into the second gear pump 5 is prevented, thus avoiding damage to the second gear pump 5 and ensuring the reliability of the injection molding machine's hydraulic system.

[0031] Furthermore, the first gear pump 4 and the second gear pump 5 have smaller displacement and smaller inertia compared to gear pumps in related technologies, which results in faster system response and relatively higher system control accuracy.

[0032] Preferably, the maximum speed of the servo motor 6 in this embodiment is greater than or equal to 3000 r / min. Compared with the low-speed servo motors with speeds of 1500 r / min to 2000 r / min in related technologies, the servo motor 6 provided in this embodiment has a higher speed to ensure that the flow rate required by the injection molding machine is met.

[0033] Optionally, the injection molding machine hydraulic system also includes a first damper 14 and a first cartridge valve 10, which are sequentially connected between the first gear pump 4 and the second end of the output oil circuit. The valve core movement of the first cartridge valve 10 is determined by the pressure difference between its control chamber and the inlet and outlet chambers. With this configuration, when oil needs to flow through the first cartridge valve 10, it first flows through the first damper 14. Due to the hydraulic resistance of the first damper 14, the pressure at the damper inlet side is higher than the pressure at the first damper outlet side, creating a pressure difference between the pressure in the inlet chamber and the control chamber of the first cartridge valve 10. This pressure difference overcomes the spring force on the cartridge valve core, pushing the valve core of the first cartridge valve 10 open, allowing the oil to flow from the inlet chamber to the outlet chamber, thus achieving oil flow.

[0034] Furthermore, the servo motor 6 is connected to the second gear pump 5, and a first oil circuit is provided between the second gear pump 5 and the oil tank 1. A directional valve 8 is installed on the first oil circuit. With this configuration, when the injection molding machine is in a high-pressure, low-flow condition, the directional valve 8 can be controlled to connect the first oil circuit, reducing the load on the second gear pump 5, thereby reducing the load on the servo motor 6, achieving high torque output and energy saving.

[0035] Optionally, the first oil circuit also includes a relief valve 12 and a directional valve 13. The input end of the directional valve 13 is connected to the input end of the relief valve 12, and the output end of the directional valve 13 and the output end of the relief valve 12 are both connected to the oil tank 1.

[0036] Optionally, the injection molding machine hydraulic system also includes a second oil circuit, which includes a second damper 15 and a second cartridge valve 11 connected in sequence. One end of the second oil circuit is connected between the first gear pump 4 and the first check valve 7, and the other end is connected to the first oil circuit. Specifically, when the relief valve 12 acts as a pilot valve in conjunction with the second cartridge valve 11, if the pressure of the injection molding machine hydraulic system does not reach the set pressure of the relief valve 12, the relief valve 12 is closed, and the pressure in the control chamber of the second cartridge valve 11 is equal to the pressure at the inlet of the second cartridge valve 11, thus closing the second cartridge valve 11. When the pressure of the injection molding machine hydraulic system exceeds the set pressure of the relief valve 12, the relief valve 12 opens, and the oil flows back to the oil tank 1 through the relief valve 12. Under the action of the second damper 15, the pressure in the control chamber of the second cartridge valve 11 decreases, and the second cartridge valve 11 opens, allowing excess oil to flow back to the oil tank 1 through the second cartridge valve 11, maintaining stable system pressure.

[0037] When the reversing valve 13 is energized, the valve port of the reversing valve 13 opens. Under the action of the second damper 15, the control chamber pressure of the second cartridge valve 11 decreases, the second cartridge valve 11 opens, and the oil from the second gear pump 5 and the first gear pump 4 can flow back to the oil tank 1 through the second cartridge valve 11. With this setting, the large flow of oil in the injection molding machine can circulate quickly in the oil tank 1 to preheat the oil temperature.

[0038] Optionally, the injection molding machine hydraulic system also includes a third oil circuit. One end of the third oil circuit is connected to the second end of the output oil circuit, and the other end of the third oil circuit is connected to the oil tank 1. The third oil circuit includes an accumulator 17, a second check valve 16, and a proportional relief valve 18. One end of the second check valve 16 is connected to the second end of the output oil circuit, and the other end of the second check valve 16 is connected to the accumulator 17. The proportional relief valve 18 is connected between the second end of the output oil circuit and the oil tank 1. With this configuration, when the injection molding machine hydraulic system starts or experiences a pressure surge, high-pressure oil can enter the accumulator 17, thereby reducing the pressure peak, absorbing the pressure surge, and preventing damage to the injection molding machine hydraulic system.

[0039] Optionally, a pressure sensor 9 is connected to the first end of the output oil circuit. The pressure sensor 9 is used to detect the pressure at the oil outlet of the one that is furthest from the servo motor 6, either the first gear pump 4 or the second gear pump 5. The pressure sensor 9 provides real-time feedback on the pressure of the output oil circuit of the injection molding machine's hydraulic system, preventing overload and malfunctions in the hydraulic system.

[0040] Optionally, the injection molding machine hydraulic system also includes a first suction filter 2 and a second suction filter 3. The first suction filter 2 is installed between the first gear pump 4 and the oil tank 1, and the second suction filter 3 is installed between the second gear pump 5 and the oil tank 1. This arrangement filters the oil in the oil tank 1 through the first and second filters before it flows to the first gear pump 4 and the second gear pump 5 respectively. This prevents impurities in the oil from entering the first and second gear pumps 4 and 5, damaging their internal parts, causing malfunctions, and improving the service life of the injection molding machine hydraulic system.

[0041] On the other hand, this embodiment provides an injection molding machine, which includes a body and the above-mentioned injection molding machine hydraulic system. The body is provided with an oil inlet end, which is connected to the second end of the output oil circuit of the injection molding machine hydraulic system.

[0042] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A hydraulic system for an injection molding machine, characterized in that, include: Oil tank (1), the oil tank (1) is used to store oil; The first gear pump (4) and the second gear pump (5) are located below the oil level in the oil tank (1), with the oil suction pipes of the first gear pump (4) and the second gear pump (5) connected in series. A first check valve (7) is provided between the first gear pump (4) and the second gear pump (5). A servo motor (6) is connected to the first gear pump (4) and the second gear pump (5), and the servo motor (6) can drive the first gear pump (4) and the second gear pump (5) to operate; The output oil circuit has a first end connected to the oil outlet of the first gear pump (4) and / or the second gear pump (5), and a second end connected to the oil inlet of the injection molding machine.

2. The hydraulic system of an injection molding machine according to claim 1, wherein, The hydraulic system of the injection molding machine also includes a first damper (14) and a first cartridge valve (10), the first damper (14) and the cartridge valve being connected in sequence between the first gear pump (4) and the second end of the output oil circuit.

3. The hydraulic system of an injection molding machine according to claim 1, wherein, The servo motor (6) is connected to the second gear pump (5), and a first oil circuit is provided between the second gear pump (5) and the oil tank (1), and a directional valve (8) is provided on the first oil circuit.

4. The hydraulic system of an injection molding machine according to claim 3, wherein The first oil circuit also includes an overflow valve (12) and a reversing valve (13). The input end of the reversing valve (13) is connected to the input end of the overflow valve (12), and the output end of the reversing valve (13) and the output end of the overflow valve (12) are both connected to the oil tank (1).

5. The hydraulic system of an injection molding machine according to claim 4, wherein The hydraulic system of the injection molding machine also includes a second oil circuit, which includes a second damper (15) and a second cartridge valve (11) connected in sequence. One end of the second oil circuit is connected between the first gear pump (4) and the first check valve (7), and the other end of the second oil circuit is connected to the first oil circuit.

6. The hydraulic system for injection molding machines according to any of claims 1-5, characterized in that, The hydraulic system of the injection molding machine also includes a third oil circuit. One end of the third oil circuit is connected to the second end of the output oil circuit, and the other end of the third oil circuit is connected to the oil tank (1). The third oil circuit includes an accumulator (17), a second check valve (16), and a proportional relief valve (18). One end of the second check valve (16) is connected to the second end of the output oil circuit, and the other end of the second check valve (16) is connected to the accumulator (17). The proportional relief valve (18) is connected between the second end of the output oil circuit and the oil tank (1).

7. The hydraulic system for injection molding machines according to any of claims 1-5, characterized in that, The first end of the output oil circuit is connected to a pressure sensor (9), which is used to detect the pressure at the oil outlet of the one that is furthest from the servo motor (6) between the first gear pump (4) and the second gear pump (5).

8. The hydraulic system for injection molding machines according to any of claims 1-5, characterized in that, The hydraulic system of the injection molding machine also includes a first oil suction filter (2) and a second oil suction filter (3). The first oil suction filter (2) is installed between the first gear pump (4) and the oil tank (1), and the second oil suction filter (3) is installed between the second gear pump (5) and the oil tank (1).

9. The hydraulic system for injection molding machines according to any of claims 1-5, characterized in that, The maximum speed of the servo motor (6) is greater than or equal to 3000 r / min.

10. An injection molding machine characterized by, The injection molding machine includes a body and a hydraulic system for injection molding machines according to any one of claims 1-9. The body is provided with an oil inlet end, which is connected to the second end of the output oil circuit of the hydraulic system for injection molding machines.

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