Hydraulic system for a locking regeneration circuit of an injection molding machine

Abstract

The utility model provides a kind of injection molding machine locking regeneration loop hydraulic system.Solve the problem that multiple reversing valves are needed to realize pressure boost in the existing injection molding machine locking hydraulic system, which is high in cost and large in size.It includes locking cylinder, oil tank, oil pump and cartridge valve, the locking cylinder includes piston, rodless cavity and rod cavity;It also includes: reversing valve, the oil pump is connected with reversing valve through first oil way;The reversing valve has the first position of cutoff when in the middle position, so that the oil pump is communicated with rodless cavity and the rod cavity is communicated with oil tank;The third position makes the oil pump be communicated with rodless cavity and disconnects the communication between rod cavity and oil tank;The fourth position makes the oil pump be communicated with rod cavity and rodless cavity be communicated with oil tank;The cartridge valve is opened when the reversing valve is in the third position, so that the rod cavity is communicated with first oil way.The utility model has the advantages of simple structure, small size, low energy consumption, convenient and reliable control, long service life and the like.

Description

Technical Field

[0001] This utility model relates to an injection molding machine, specifically to a hydraulic system for the mold clamping and regeneration circuit of an injection molding machine. Background Technology

[0002] In the market, injection molding machines typically employ a double-crankshaft mechanism or a hydraulic cylinder structure for the mold clamping thrust. During the mold opening and closing process, the clamping process generally involves three stages: slow speed, fast speed, and slow speed (high pressure). To improve the machine's operating speed and mold platen positioning accuracy during clamping, injection molding machines often use a rapid clamping regeneration circuit system. This rapid movement is achieved by externally installing proportional and identical directional valves, which also require connection to the main control power supply. This increases the size and weight of the integrated block used for the directional valve installation, leading to a larger overall product size, complicated installation, and increased leakage points. The added directional valves also complicate design and manufacturing, ultimately reducing the overall economic efficiency of the machine. The switching process of the mold clamping motion can also be unsmooth, and there may be jamming during the switching. It is necessary to match the computer control settings to make the action smooth. The debugging is complicated, and the directional valve is prone to failure when used quickly. Troubleshooting is difficult and it is not conducive to maintenance. Utility Model Content

[0003] To address the problems of high cost and large size associated with existing injection molding machine clamping hydraulic systems requiring multiple directional valves for pressurization, this invention provides an injection molding machine clamping regeneration circuit hydraulic system.

[0004] The technical solution of this utility model is: a hydraulic system for a mold-locking regeneration circuit of an injection molding machine, including a mold-locking cylinder, wherein the mold-locking cylinder includes a piston, and the piston divides the internal space of the mold-locking cylinder into a rodless chamber and a rod chamber; further comprising: The fuel tank is used for fuel return. An oil pump, connected to an oil tank, is used to output hydraulic oil from the oil tank; the oil pump is connected to the first oil circuit; A cartridge valve is located between the rod chamber and the first oil passage; The reversing valve is provided, wherein the oil pump is connected to the reversing valve via a first oil circuit; the reversing valve has a first position where it is closed when in the neutral position, a second position where the oil pump is connected to the rodless chamber and the rod chamber is connected to the oil tank, a third position where the oil pump is connected to the rodless chamber and the rod chamber is disconnected from the oil tank, and a fourth position where the oil pump is connected to the rod chamber and the rodless chamber is connected to the oil tank; the cartridge valve is opened when the reversing valve is in the third position, so that the rod chamber is connected to the first oil circuit.

[0005] As a further improvement of this utility model, the cartridge valve includes a valve core and an elastic element. The valve core has an open first position and a closed second position. The elastic element abuts against the valve core and causes the valve core to have a tendency to move towards its second position.

[0006] As a further improvement of this utility model, the cartridge valve includes a spring cavity, and the first oil circuit is connected to the spring cavity. The hydraulic oil in the first oil circuit and the elastic force of the elastic element cooperate with each other to make the valve core have a tendency to move towards its second position.

[0007] As a further improvement of this utility model, it also includes a second oil circuit, through which the reversing valve and the mold locking cylinder are connected.

[0008] As a further improvement of this utility model, the second oil circuit is connected to the reversing valve and the second oil circuit is connected to the mold locking cylinder through a rigid pipe.

[0009] As a further improvement of this utility model, the second oil circuit includes a hose section, which is connected to a rigid pipe.

[0010] As a further improvement of this utility model, the reversing valve is a four-position four-way reversing valve.

[0011] As a further improvement of this utility model, the reversing valve is an electro-proportional reversing valve.

[0012] As a further improvement of this utility model, the reversing valve is disposed in the valve body, and the cartridge valve is inserted into the valve body and detachably connected to the valve body.

[0013] As a further improvement of this utility model, the cartridge valve is a one-way valve.

[0014] The beneficial effects of this utility model are that it incorporates a reversing valve and a cartridge valve. The reversing valve connects the oil pump to the rodless chamber and disconnects the rod chamber from the oil tank. At this time, oil from the rod chamber can return to the first oil circuit and enter the rodless chamber through the reversing valve, thus accelerating the piston's forward movement, stabilizing the switching action, and resulting in a simple structure and low manufacturing cost. This utility model also boasts advantages such as simple structure, small size, reliable operation, low energy consumption, convenient and reliable control, and long service life. Attached Figure Description

[0015] Appendix Figure 1 This is a schematic diagram of the hydraulic principle when the directional valve is in the first position according to an embodiment of the present invention.

[0016] Appendix Figure 2 This is a schematic diagram of the hydraulic principle when the directional valve is in the second position according to an embodiment of the present invention.

[0017] Appendix Figure 3 This is a schematic diagram of the hydraulic principle when the directional valve is in the third position according to an embodiment of the present invention.

[0018] Appendix Figure 4 This is a schematic diagram of the hydraulic principle when the directional valve is in the fourth position according to an embodiment of the present invention.

[0019] Appendix Figure 5 This is a schematic diagram of the structure of the mold-locking cylinder in an embodiment of the present invention.

[0020] In the diagram, 1 is the mold-locking cylinder; 11 is the piston; 12 is the rodless chamber; 13 is the rod chamber; 2 is the oil tank; 3 is the oil pump; 4 is the cartridge valve; 41 is the valve core; 42 is the elastic element; 43 is the spring chamber; 5 is the first oil passage; 6 is the second oil passage; 61 is the rigid pipe; 62 is the hose section; and 7 is the reversing valve. Detailed Implementation

[0021] The embodiments of this utility model will be further described below with reference to the accompanying drawings: Depend on Figure 1 Combination Figure 2-5 As shown, a hydraulic system for a mold clamping and regeneration circuit in an injection molding machine includes a mold clamping cylinder 1, wherein the mold clamping cylinder 1 includes a piston 11, and the piston 11 divides the internal space of the mold clamping cylinder 1 into a rodless chamber 12 and a rod chamber 13; it also includes: Oil tank 2 is used for oil return; Oil pump 3 is connected to oil tank 2 and is used to output hydraulic oil from oil tank 2; oil pump 3 is connected to the first oil circuit 5; Cartridge valve 4 is located between rod chamber 13 and first oil passage 5; The reversing valve 7 is connected to the oil pump 3 via the first oil passage 5. The reversing valve 7 has a first position where it is closed when neutral, a second position where the oil pump 3 is connected to the rodless chamber 12 and the rod chamber 13 is connected to the oil tank 2, a third position where the oil pump 3 is connected to the rodless chamber 12 and the rod chamber 13 is disconnected from the oil tank 2, and a fourth position where the oil pump 3 is connected to the rod chamber 13 and the rodless chamber 12 is connected to the oil tank 2. The cartridge valve 4 opens when the reversing valve 7 is in the third position, connecting the rod chamber 13 to the first oil passage 5. The beneficial effects of this invention are that by providing a reversing valve and a cartridge valve, the reversing valve connects the oil pump to the rodless chamber and disconnects the rod chamber from the oil tank. At this time, oil from the rod chamber can return to the first oil passage and enter the rodless chamber through the reversing valve, resulting in faster piston movement, stable switching action, simple structure, and low manufacturing cost. This invention solves the problem of slow speed and low efficiency of existing mold-locking cylinders during intermediate movement. When the directional valve stem reaches the third position, hydraulic oil in the rod chamber is replenished from the cartridge valve to the first oil circuit and acts on the rodless chamber, resulting in faster speed and higher efficiency for the mold-locking cylinder during intermediate movement. This invention also has advantages such as simple structure, small size, reliable operation, low energy consumption, convenient and reliable control, and long service life. (The invention is accompanied by...) Figure 1 This is a hydraulic schematic diagram of a directional control valve with the valve stem in the neutral position. (Attached) Figure 2 A schematic diagram showing the piston moving forward during slow mold locking when the valve stem of the directional valve is in the second position; attached. Figure 3 A schematic diagram showing the energization of the rapid mold-locking regeneration circuit when the valve stem of the reversing valve is in the third position; attached. Figure 3 This is a schematic diagram showing the piston retracting when the mold opens, with the valve stem of the directional valve in the fourth position.

[0022] Further explanation is provided in conjunction with the accompanying drawings: Appendix Figure 1 This is the initial state; When the slow-speed mold-locking proportional directional valve actuates, see Appendix Figure 2 When Y2 receives a control command signal, the main valve core (reversing valve rod) moves. The pressurized oil passes through the proportional directional valve 7, and then through the P→A of the directional valve into the rodless chamber of the mold-locking cylinder, pushing the piston forward slowly. The oil in the rod chamber flows back to the oil tank through the B→T of the proportional directional valve 7. At this time, the cartridge valve 4 is in the closed state and will not open.

[0023] When the fast mode-locking regeneration circuit is energized, refer to the appendix. Figure 3When the slow mold-locking action enters the fast mold-locking stage, the command signal received by Y2 causes the main valve core (the reversing valve stem of the directional valve) to move to P→A, blocking chambers B and T. Pressure oil enters the rodless chamber of the mold-locking cylinder through P→A, pushing the piston forward slowly. Oil from the rod chamber flows towards the cartridge valve. Since the output pressure of the rod chamber is the pressure of the pressure oil in the rodless chamber multiplied by the contact area at the piston in the rodless chamber divided by the contact area at the piston in the rod chamber, and since chambers B and T of the directional valve are blocked at this time, the high pressure is blocked, eventually opening the cartridge valve. That is, the pressure oil in the rod chamber actively pushes open the cartridge valve core, and the hydraulic oil flows from port C to port D of the cartridge valve core, entering the first oil circuit and merging with the pressure oil to flow towards the rodless chamber, realizing the complete oil circuit system of the fast regeneration circuit.

[0024] At this point, the piston moves forward at a faster speed, the switching action is stable, the structure is simple, and the manufacturing cost is low. The mold opening circuit is energized; see attached diagram. Figure 4 When Y1 receives the command signal, the main valve core (reversing valve rod) moves. Pressurized oil passes through the proportional directional valve, P→B, and enters the rod chamber of the mold-locking cylinder, pushing the piston backward. Oil in the rodless chamber flows back to the oil tank through the proportional directional valve, A→T. At this time, the cartridge valve is in the closed state and will not open.

[0025] The cartridge valve 4 includes a valve core 41 and an elastic element 42. The valve core 41 has an open first position and a closed second position. The elastic element 42 abuts against the valve core 41, causing the valve core 41 to tend towards its second position. Specifically, the cartridge valve 4 includes a spring cavity 43, and the first oil passage 5 is connected to the spring cavity 43. The hydraulic oil in the first oil passage 5 and the elastic force of the elastic element 42 cooperate to cause the valve core 41 to tend towards its second position. This makes the cartridge valve structure simple and easy to control, and allows for convenient and rapid merging when the directional valve is in the third position.

[0026] This utility model also includes a second oil passage 6, through which the reversing valve 7 and the mold-locking cylinder 1 are connected. Specifically, the second oil passage 6 is connected to the reversing valve 7 and the mold-locking cylinder 1 via a rigid pipe 61. More specifically, the second oil passage 6 includes a hose section 62, which is connected to the rigid pipe 61. The hose section facilitates connection, and the second oil passage remains reliably connected even when the mold-locking cylinder piston is actuated. The structure is simple, and the connection is convenient and reliable.

[0027] The aforementioned directional control valve 7 is a four-position four-way directional control valve. Specifically, the directional control valve 7 is an electro-proportional directional control valve. The proportional directional control valve is controlled by a command signal of 0~±10V. The magnitude of the command signal voltage output enables precise control by moving the main valve core (directional control valve stem). Positive, negative, and zero signal outputs enable the main valve core (directional control valve stem) to move left and right or remain in the neutral position. The proportional directional control valve adopts a four-position four-way structure, and its installation method and external structure are consistent with conventional proportional directional control valves, ensuring strong interchangeability.

[0028] The directional valve 7 is located within the valve body, and the cartridge valve 4 is inserted into the valve body and detachably connected to the valve body. Specifically, the cartridge valve 4 is a one-way valve. More specifically, the directional valve includes a valve body and a directional valve stem (main valve core). The cartridge valve can be directly and detachably connected to the directional valve, resulting in a simple structure and convenient assembly.

[0029] In the description of this utility model, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They 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, and therefore should not be construed as a limitation on this utility model. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of 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. Furthermore, in the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0031] Please note to all technical personnel: Although this utility model has been described according to the specific embodiments above, the inventive concept of this utility model is not limited to this utility model. Any modification that utilizes the inventive concept will be included within the scope of protection of this utility model patent.

Claims

1. A hydraulic system for a mold-locking regeneration circuit in an injection molding machine, comprising a mold-locking cylinder (1), wherein the mold-locking cylinder (1) includes a piston (11), the piston (11) dividing the internal space of the mold-locking cylinder (1) into a rodless chamber (12) and a rod chamber (13); characterized in that: Also includes: Oil tank (2) is used for oil return; The oil pump (3) is connected to the oil tank (2) and is used to output hydraulic oil from the oil tank (2); the oil pump (3) is connected to the first oil circuit (5); A cartridge valve (4) is located between the rod chamber (13) and the first oil passage (5); The reversing valve (7) is connected to the oil pump (3) through the first oil passage (5). The reversing valve (7) has a first position where it is cut off when in the middle position, a second position where the oil pump (3) is connected to the rodless chamber (12) and the rod chamber (13) is connected to the oil tank (2), a third position where the oil pump (3) is connected to the rodless chamber (12) and the rod chamber (13) is disconnected from the oil tank (2), and a fourth position where the oil pump (3) is connected to the rod chamber (13) and the rodless chamber (12) is connected to the oil tank (2). The cartridge valve (4) is opened when the reversing valve (7) is in the third position, so that the rod chamber (13) is connected to the first oil passage (5).

2. The hydraulic system for mold clamping and regeneration circuit of an injection molding machine according to claim 1, characterized in that... The cartridge valve (4) includes a valve core (41) and an elastic element (42). The valve core (41) has an open first position and a closed second position. The elastic element (42) abuts against the valve core (41) and causes the valve core (41) to have a tendency to move toward its second position.

3. The hydraulic system for mold clamping and regeneration circuit of an injection molding machine according to claim 2, characterized in that... The cartridge valve (4) includes a spring cavity (43), and the first oil passage (5) is connected to the spring cavity (43). The hydraulic oil in the first oil passage (5) and the elastic force of the elastic element (42) cooperate with each other to make the valve core (41) tend to move towards its second position.

4. The hydraulic system for mold clamping and regeneration circuit of an injection molding machine according to claim 1, characterized in that... It also includes a second oil circuit (6), through which the reversing valve (7) is connected to the mold-locking cylinder (1).

5. The hydraulic system for mold clamping and regeneration circuit of an injection molding machine according to claim 4, characterized in that... The second oil circuit (6) is connected to the reversing valve (7) and the mold locking cylinder (1) through a rigid pipe (61).

6. The hydraulic system for mold clamping and regeneration circuit of an injection molding machine according to claim 5, characterized in that... The second oil circuit (6) includes a hose section (62), which is connected to a rigid pipe (61).

7. The hydraulic system for mold clamping and regeneration circuit of an injection molding machine according to claim 1, characterized in that... The reversing valve (7) is a four-position four-way reversing valve.

8. The hydraulic system for mold clamping and regeneration circuit of an injection molding machine according to claim 1, characterized in that... The reversing valve (7) is an electro-proportional reversing valve.

9. A hydraulic system for mold clamping and regeneration circuit of an injection molding machine according to claim 1, characterized in that... The reversing valve (7) is located in the valve body, and the cartridge valve (4) is inserted into the valve body and detachably connected to the valve body.

10. A hydraulic system for mold clamping and regeneration circuit of an injection molding machine according to claim 1, characterized in that... The cartridge valve (4) is a one-way valve.

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