Mould opening and closing backpressure oil way of injection molding machine

Abstract

The utility model discloses a mold opening and closing backpressure oil way of an injection molding machine. The mold opening and closing backpressure oil way comprises an oil inlet line, an oil return line, an injection moving line, a mold opening oil port MO, a mold closing oil port MC, a first reversing valve and a backpressure line, the mold opening oil port MO is connected with a working oil port B of the first reversing valve, the mold closing oil port MC is connected with a working oil port A of the first reversing valve, and an oil inlet P of the first reversing valve is connected with an oil inlet line; the back pressure circuit comprises a logic valve, a second reversing valve and a pressure control valve, a first oil port of the logic valve and a working oil port B1 of the second reversing valve are both connected with one end of the pressure control valve, and a second oil port B2 of the logic valve, an oil return port T1 of the second reversing valve and the other end of the pressure control valve are jointly connected with an oil return circuit; a third oil port A2 of the logic valve and an oil inlet P1 of the second reversing valve are jointly connected with an oil return port T of the first reversing valve; according to the utility model, backpressure can exist in a loop, the effect of eliminating inertia can be achieved by controlling the magnitude of the backpressure, mold opening positioning is more accurate, and the purposes of economy and multiple purposes can be achieved.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic circuits for mold opening and closing in injection molding machines, and in particular to a back pressure hydraulic circuit for mold opening and closing in injection molding machines. Background Technology

[0002] Injection molding machines, also known as injection molding machines or injection molding machines, are often called "pig injection machines" in many factories, and injection-molded products are called "pig injection parts." They are the main molding equipment used to create various shapes of plastic products from thermoplastic or thermosetting materials using plastic molds. Injection molding machines can be classified into vertical, horizontal, and vertical-horizontal combined types according to the arrangement of the injection unit and mold clamping unit.

[0003] Currently, due to the characteristics of vertical injection molding machines, the screw of the injection molding machine is generally arranged vertically. Due to the weight of the screw, the hydraulic motor that drives the screw to rotate, the hydraulic motor seat, and the drive shaft, the molten plastic will be subjected to greater pressure (also known as back pressure) during material storage. Especially for plastics with good fluidity such as nylon and POM, the plastic will overflow from the nozzle or the feed port of the mold nozzle during material storage, resulting in a great waste of raw materials and failing to achieve the goal of economy. Moreover, during mold opening and closing, the inertia of the hydraulic system itself leads to inaccurate positioning when opening the mold.

[0004] Therefore, a new technology needs to be developed to solve the above problems. Utility Model Content

[0005] In view of this, the present invention addresses the deficiencies of the existing technology and its main purpose is to provide a back pressure oil circuit for the mold opening and closing of an injection molding machine. This circuit allows back pressure to exist in the circuit, and by controlling the magnitude of the back pressure, it can eliminate inertia, making the mold opening positioning more accurate, and achieving an economical and multi-purpose purpose.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An injection molding machine's mold opening and closing back pressure oil circuit includes an oil inlet line, an oil return line, an injection line, an opening port MO, a closing port MC, and a first directional valve; the injection line receives oil from the oil inlet line and returns oil from the oil return line; the opening port MO is connected to the working port B of the first directional valve, the closing port MC is connected to the working port A of the first directional valve, and the inlet P of the first directional valve is connected to the oil inlet line;

[0008] It also includes a back pressure line, which includes a logic valve, a second directional valve, and a pressure control valve. The first oil port of the logic valve and the working oil port B1 of the second directional valve are both connected to one end of the pressure control valve. The second oil port B2 of the logic valve, the return oil port T1 of the second directional valve, and the other end of the pressure control valve are all connected to the return oil line. The third oil port A2 of the logic valve and the inlet oil port P1 of the second directional valve are all connected to the return oil port T of the first directional valve.

[0009] As a preferred embodiment, the injection line includes a third directional valve, the oil inlet P2 of the third directional valve and the oil inlet P of the first directional valve are connected to the oil inlet line, and the oil return port T2 of the third directional valve is connected to the oil return line.

[0010] As a preferred embodiment, the working port A of the first reversing valve is connected to the mold closing port MC via a first check valve.

[0011] As a preferred embodiment, the first check valve is connected in parallel with a logic cartridge valve, one port of the logic cartridge valve is connected to a proportional directional valve, the working port A3 of the proportional directional valve is connected to one port of the logic cartridge valve, the inlet port P3 of the proportional directional valve is connected to the inlet line through a second check valve, and the return port T3 of the proportional directional valve is connected to the return line.

[0012] As a preferred embodiment, the first oil port of the logic valve, the working oil port B1 of the second directional valve, and one end of the pressure control valve are connected to form an outlet for pressure measurement.

[0013] Compared with the prior art, this utility model has obvious advantages and beneficial effects. Specifically, as can be seen from the above technical solution, it mainly achieves this by setting up a back pressure line, which includes a logic valve, a second directional valve, and a pressure control valve. The first oil port of the logic valve and the working oil port B1 of the second directional valve are both connected to one end of the pressure control valve. The second oil port B2 of the logic valve, the return oil port T1 of the second directional valve, and the other end of the pressure control valve are all connected to the return oil line. Furthermore, the third oil port A2 of the logic valve and the inlet oil port P1 of the second directional valve are all connected to the return oil port T of the first directional valve. In this way, a back pressure line can be set up in the return oil line, which can create back pressure in the circuit. By controlling the magnitude of the back pressure, the inertia can be eliminated, the mold opening and positioning can be more accurate, and an economical and multi-purpose purpose can be achieved.

[0014] To more clearly illustrate the structural features, technical means, and specific objectives and functions of this utility model, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0015] Figure 1This is a schematic diagram of the oil circuit structure according to an embodiment of the present invention.

[0016] Explanation of reference numerals in the attached diagram:

[0017] 10. Oil inlet line; 20. Oil return line

[0018] 30. Injection line; 40. First directional valve

[0019] 50. Logic valve; 60. Second directional valve

[0020] 70. Pressure control valve; 80. Third directional valve

[0021] 90. First check valve; 101. Logic cartridge valve

[0022] 102. Proportional directional valve; 103. Second check valve. Detailed Implementation

[0023] Please refer to Figure 1 As shown, it illustrates the specific structure of an embodiment of the present invention.

[0024] An injection molding machine's mold opening and closing back pressure oil circuit includes an oil inlet line 10, an oil return line 20, an injection line 30, a mold opening port MO, a mold closing port MC, and a first directional valve 40; the injection line 30 receives oil from the oil inlet line 10 and returns oil from the oil return line 20; the mold opening port MO is connected to the working port B of the first directional valve 40, the mold closing port MC is connected to the working port A of the first directional valve 40, and the oil inlet P of the first directional valve 40 is connected to the oil inlet line 10.

[0025] The back pressure oil circuit for mold opening and closing of the injection molding machine also includes a back pressure line. This back pressure line includes a logic valve 50, a second directional valve 60, and a pressure control valve 70. The first oil port of the logic valve 50 and the working oil port B1 of the second directional valve 60 are both connected to one end of the pressure control valve 70. The second oil port B2 of the logic valve 50, the return oil port T1 of the second directional valve 60, and the other end of the pressure control valve 70 are all connected to the return oil line 20. The third oil port A2 of the logic valve 50 and the inlet oil port P1 of the second directional valve 60 are all connected to the return oil port T of the first directional valve 40. Thus, by setting a back pressure line in the return oil line 20, back pressure exists in the circuit. By controlling the magnitude of the back pressure, inertia can be eliminated, resulting in more accurate mold opening and positioning, and achieving an economical and multi-purpose purpose.

[0026] The first oil port of the logic valve 50, the working oil port B1 of the second directional valve 60, and one end of the pressure control valve 70 are connected to form an outlet for pressure measurement. This outlet can be connected to a pressure gauge to visually display the system pressure value, providing pressure feedback to the oil circuit system, helping operators judge load changes and component operating status, and assisting in adjusting control strategies. Furthermore, the pressure control valve 70 can monitor the oil circuit system pressure in real time and relieve pressure in case of overpressure.

[0027] The injection line 30 includes a third directional valve 80. The oil inlet P2 of the third directional valve 80 and the oil inlet P of the first directional valve 40 are connected to the oil inlet line 10. The oil return port T2 of the third directional valve 80 is connected to the oil return line 20.

[0028] The working port A of the first directional valve 40 is connected to the mold closing port MC via a first check valve 90 to prevent backflow of oil. A logic cartridge valve 101 is connected in parallel to the first check valve 90. One port of the logic cartridge valve 101 is connected to a proportional directional valve 102, and the working port A3 of the proportional directional valve 102 is connected to one port of the logic cartridge valve 101. The inlet port P3 of the proportional directional valve 102 is connected to the oil inlet line 10 via a second check valve 103 to prevent backflow of oil. The return port T3 of the proportional directional valve 102 is connected to the return line 20. Here, the first directional valve 40 can control the main oil flow direction, and in conjunction with the logic cartridge valve 101, precise control under high flow rates can be achieved. The proportional directional valve 102 can further refine the flow and pressure regulation to meet the multi-condition requirements of the actuator.

[0029] In summary, the key design feature of this utility model lies in its back pressure circuit, which includes a logic valve, a second directional valve, and a pressure control valve. The first port of the logic valve and the working port B1 of the second directional valve are both connected to one end of the pressure control valve. The second port B2 of the logic valve, the return port T1 of the second directional valve, and the other end of the pressure control valve are all connected to the return oil circuit. Furthermore, the third port A2 of the logic valve and the inlet port P1 of the second directional valve are all connected to the return port T of the first directional valve. This design achieves a back pressure circuit in the return oil circuit, ensuring back pressure in the loop. By controlling the magnitude of the back pressure, inertia can be eliminated, resulting in more accurate mold opening and positioning, and achieving an economical and multi-purpose design.

[0030] The above description is merely a preferred embodiment of the present utility model and does not constitute any limitation on the technical scope of the present utility model. Therefore, any minor modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall still fall within the scope of the technical solution of the present utility model.

Claims

1. A mold opening and closing back pressure oil circuit for an injection molding machine, comprising an oil inlet line, an oil return line, an injection line, a mold opening port MO, a mold closing port MC, and a first directional valve; the injection line receives oil from the oil inlet line and returns oil from the oil return line; the mold opening port MO is connected to the working port B of the first directional valve, the mold closing port MC is connected to the working port A of the first directional valve, and the oil inlet P of the first directional valve is connected to the oil inlet line; characterized in that: It also includes a back pressure line, which includes a logic valve, a second directional valve, and a pressure control valve. The first oil port of the logic valve and the working oil port B1 of the second directional valve are both connected to one end of the pressure control valve. The second oil port B2 of the logic valve, the return oil port T1 of the second directional valve, and the other end of the pressure control valve are all connected to the return oil line. The third oil port A2 of the logic valve and the inlet oil port P1 of the second directional valve are all connected to the return oil port T of the first directional valve.

2. The mold opening and closing back pressure oil circuit of an injection molding machine according to claim 1, characterized in that: The injection line includes a third directional valve, the oil inlet P2 of the third directional valve and the oil inlet P of the first directional valve are connected to the oil inlet line, and the oil return port T2 of the third directional valve is connected to the oil return line.

3. The mold opening and closing back pressure oil circuit of an injection molding machine according to claim 1, characterized in that: The working port A of the first reversing valve is connected to the mold closing port MC through the first check valve.

4. The mold opening and closing back pressure oil circuit of an injection molding machine according to claim 3, characterized in that: The first check valve is connected in parallel with a logic cartridge valve. One port of the logic cartridge valve is connected to a proportional directional valve. The working port A3 of the proportional directional valve is connected to one port of the logic cartridge valve. The inlet port P3 of the proportional directional valve is connected to the inlet line through the second check valve. The return port T3 of the proportional directional valve is connected to the return line.

5. The mold opening and closing back pressure oil circuit of an injection molding machine according to claim 1, characterized in that: The first oil port of the logic valve, the working oil port B1 of the second directional valve, and one end of the pressure control valve are connected to form an outlet for pressure measurement.

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