A pressure-maintaining injection system and a long injection pressure-maintaining method

Abstract

The present invention discloses a pressure-maintaining injection system and a long injection pressure-maintaining method, comprising an oil supply unit, an injection unit, a reversing unit, a control unit and a motor unit; the output end and the input end of the oil supply unit are respectively connected to one of the oil circuits of the reversing unit, and the output end and the input end of the injection unit are respectively connected to the other oil circuit of the reversing unit; the input end of the control unit is connected to the output end of the oil supply unit, the first output end of the control unit is connected to the input end of the injection unit, the second output end of the control unit is connected to the oil inlet of the motor unit, and the oil outlet of the motor unit is connected to the input end of the oil supply unit; the output end of the motor unit is connected to the injection unit; the present invention aims to provide a pressure-maintaining injection system and a long injection pressure-maintaining method, which ensure the stability and continuity of injection pressure, reduce the loss of injection pressure, and improve the quality of products.

Description

Technical Field

[0001] The present invention relates to the field of automation control technology, and in particular to a pressure-maintaining injection system and a long injection pressure-maintaining method. Background Art

[0002] With the development of industrial technology, electronic and electrical technology, servo motor systems are becoming more and more common in industrial automation control. With the development of science and technology, many high-quality, high-tech products have emerged. This has put forward higher requirements for machines. The traditional servo motor system has a fast oil pressure increase, but also a fast pressure loss. In this way, when the injection pressure needs to be maintained for a long time when making high-precision products, the injection pressure will fluctuate, resulting in a loss of injection pressure and unstable product quality. It causes waste and loss of materials, labor, and funds. Summary of the invention

[0003] The purpose of the present invention is to provide a pressure-maintaining injection system and a long injection pressure-maintaining method to ensure the stability and continuity of the injection pressure, reduce the loss of the injection pressure, and improve the quality of the product.

[0004] To achieve this purpose, the present invention adopts the following technical scheme: a pressure-maintaining injection system, comprising an oil supply unit, an injection unit, a reversing unit, a control unit and a motor unit; the output end and the input end of the oil supply unit are respectively connected to one of the oil circuits of the reversing unit, and the output end and the input end of the injection unit are respectively connected to the other oil circuit of the reversing unit; the input end of the control unit is connected to the output end of the oil supply unit, the first output end of the control unit is connected to the input end of the injection unit, the second output end of the control unit is connected to the oil inlet of the motor unit, and the oil outlet of the motor unit is connected to the input end of the oil supply unit; the output end of the motor unit is connected to the injection unit.

[0005] Preferably, the oil supply unit includes a servo motor assembly, a total pressure control valve and a pressure sensor, the input end of the servo motor assembly is connected to the oil tank through a pipeline, the output end of the servo motor assembly is connected to the input end of the reversing unit through a pipeline, and the total pressure control valve and the pressure sensor are both arranged in the pipeline between the servo motor assembly and the reversing unit.

[0006] Preferably, it also includes a total pressure gauge, which is arranged in the pipeline between the servo motor assembly and the reversing unit.

[0007] Preferably, the reversing unit includes a first electro-hydraulic valve and a second electro-hydraulic valve, the oil port P1 of the first electro-hydraulic valve is connected to the output end of the oil supply unit, the oil port T1 of the first electro-hydraulic valve is connected to the input end of the oil supply unit, the oil port A1 of the first electro-hydraulic valve is connected to the oil outlet of the injection unit, and the oil port B1 of the first electro-hydraulic valve is connected to the oil inlet of the injection unit; one electromagnetic port of the first electro-hydraulic valve is connected to the oil port A2 of the second electro-hydraulic valve, the other electromagnetic port of the first electro-hydraulic valve is connected to the oil port B2 of the second electro-hydraulic valve, the oil port P2 of the second electro-hydraulic valve is connected to the output end of the oil supply unit, and the oil port T2 of the second electro-hydraulic valve is connected to the input end of the oil supply unit.

[0008] Preferably, the control unit includes a proportional pressure valve, an injection pressure control solenoid directional valve and an injection pressure control cartridge valve; the oil port P3 of the injection pressure control solenoid directional valve is connected to the control port X1 of the injection pressure control cartridge valve, the oil port T3 of the injection pressure control solenoid directional valve is connected to the input end of the oil supply unit, the oil port A3 of the injection pressure control solenoid directional valve is connected to the proportional pressure valve, and the oil port B3 of the injection pressure control solenoid directional valve is connected to the input end of the oil supply unit; the oil port B5 of the injection pressure control cartridge valve is connected to the input end of the oil supply unit, and the oil port A5 of the injection pressure control cartridge valve is connected to the oil inlet of the injection unit.

[0009] Preferably, the control unit also includes a sol back pressure valve, a sol solenoid directional valve and a sol cartridge valve; the sol back pressure valve is arranged in a pipeline between the oil port B3 of the injection pressure control solenoid directional valve and the input end of the oil supply unit; the oil port P4 of the sol solenoid directional valve is connected to the oil port A6 of the sol cartridge valve, the oil port A6 of the sol cartridge valve is connected to the output end of the oil supply unit, the oil port T4 of the sol solenoid directional valve is connected to the input end of the oil supply unit, the oil port A4 of the sol solenoid directional valve is connected to the control port X2 of the sol cartridge valve; the oil port B6 of the sol cartridge valve is connected to the oil inlet of the motor unit.

[0010] Preferably, the control unit further comprises a sol back pressure gauge, and the sol back pressure gauge is connected to the oil port B3 of the injection pressure control solenoid directional valve.

[0011] A long injection pressure-maintaining method comprises the following steps:

[0012] Preparation steps: Adjust the maximum oil pressure safety pressure;

[0013] Preset steps: adjust the injection pressure of the proportional pressure valve;

[0014] Injection step: receiving the injection pressure command and the injection speed command, and injecting hydraulic oil into the injection unit, and the injection unit injects the plastic into the mold;

[0015] Sol step: receiving the sol instruction, the motor unit drives the sol screw of the injection unit to sol, and the control unit adjusts the sol back pressure.

[0016] Preferably, in the injection step, the servo motor assembly receives the injection pressure instruction and the injection speed instruction, the control terminal YA05 of the reversing unit is energized, the reversing unit connects the oil port P1 and the oil port B1, and hydraulic oil is injected into the injection unit, and the injection unit pushes the sol screw to inject the plastic into the mold.

[0017] Preferably, in the sol step, a sol instruction is received, the control end YA06 of the sol solenoid directional valve is energized, the sol cartridge valve is opened, the motor unit rotates to drive the sol screw of the injection unit to sol, the control end YA23 of the injection pressure control solenoid directional valve is energized, and the opening degree of the injection pressure control cartridge valve is adjusted by the sol back pressure valve, thereby adjusting the sol back pressure.

[0018] The present application adopts the above-mentioned structure, and adjusts and controls the injection unit and the motor unit through the cooperation of the reversing unit and the control unit, so as to maintain the stability and continuity of the injection pressure, avoid injection pressure fluctuations, avoid injection pressure loss, improve the density stability of the plastic when it is injected into the mold, and ensure the stability of product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings further illustrate the present invention, but the contents in the accompanying drawings do not constitute any limitation to the present invention.

[0020] Figure 1 It is a schematic diagram of the connection structure of the present invention.

[0021] Among them: oil supply unit 1, servo motor assembly 11, total pressure control valve 12, pressure sensor 13, total pressure gauge 14, injection unit 2, reversing unit 3, first electro-hydraulic valve 31, second electro-hydraulic valve 32, control unit 4, proportional pressure valve 41, injection pressure control solenoid directional valve 42, injection pressure control cartridge valve 43, sol back pressure valve 44, sol solenoid directional valve 45, sol cartridge valve 46, sol back pressure gauge 47, motor unit 5. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0023] See also Figure 1 As shown, a pressure-maintaining injection system of this embodiment includes an oil supply unit 1, a glue injection unit 2, a reversing unit 3, a control unit 4 and a motor unit 5.

[0024] The output end and the input end of the oil supply unit 1 are respectively connected to one of the oil circuits of the reversing unit 3 , and the output end and the input end of the injection unit 2 are respectively connected to the other oil circuit of the reversing unit 3 .

[0025] The input end of the control unit 4 is communicated with the output end of the oil supply unit 1, the first output end of the control unit 4 is communicated with the input end of the injection unit 2, the second output end of the control unit 4 is communicated with the oil inlet of the motor unit 5, the oil outlet of the motor unit 5 is communicated with the input end of the oil supply unit 1; the output end of the motor unit 5 is connected to the injection unit 2.

[0026] With this structure, the oil supply unit 1 and the injection unit 2 are connected through the reversing unit 3, the oil circuit is reversed, and the oil inlet or outlet of the injection unit 2 is controlled, thereby controlling the injection unit 2 to advance the injection or retract the injection. The present application adopts the above structure, and the injection unit 2 and the motor unit 5 are adjusted and controlled by the reversing unit 3 and the control unit 4 to maintain the injection pressure stable, and the injection pressure fluctuation phenomenon will not occur, so as to avoid the injection pressure loss and ensure the stability of product quality.

[0027] Preferably, the oil supply unit 1 includes a servo motor assembly 11, a total pressure control valve 12 and a pressure sensor 13, the input end of the servo motor assembly 11 is connected to the oil tank through a pipeline, the output end of the servo motor assembly 11 is connected to the input end of the reversing unit 3 through a pipeline, and the total pressure control valve 12 and the pressure sensor 13 are both arranged in the pipeline between the servo motor assembly 11 and the reversing unit 3.

[0028] With this structure, when the servo motor assembly 11 is working, it provides hydraulic oil to the reversing unit 3, detects the hydraulic oil pressure in the pipeline through the pressure sensor 13, and adjusts the opening and closing of the total pressure control valve 12 to adjust the hydraulic oil pressure in the pipeline.

[0029] Preferably, a total pressure gauge 14 is further included, and the total pressure gauge 14 is arranged in a pipeline between the servo motor assembly 11 and the reversing unit 3 .

[0030] With this structure, in order to conveniently and intuitively observe the oil pressure, a total pressure gauge 14 is provided in the pipeline between the servo motor assembly 11 and the reversing unit 3 .

[0031] Preferably, the reversing unit 3 includes a first electro-hydraulic valve 31 and a second electro-hydraulic valve 32, the oil port P1 of the first electro-hydraulic valve 31 is connected to the output end of the oil supply unit 1, the oil port T1 of the first electro-hydraulic valve 31 is connected to the input end of the oil supply unit 1, the oil port A1 of the first electro-hydraulic valve 31 is connected to the oil outlet of the injection unit 2, and the oil port B1 of the first electro-hydraulic valve 31 is connected to the oil inlet of the injection unit 2.

[0032] One electromagnetic port of the first electro-hydraulic valve 31 is connected to the oil port A2 of the second electro-hydraulic valve 32, another electromagnetic port of the first electro-hydraulic valve 31 is connected to the oil port B2 of the second electro-hydraulic valve 32, the oil port P2 of the second electro-hydraulic valve 32 is connected to the output end of the oil supply unit 1, and the oil port T2 of the second electro-hydraulic valve 32 is connected to the input end of the oil supply unit 1.

[0033] With this structure, the first electro-hydraulic valve 31 and the second electro-hydraulic valve 32 cooperate to form an injection and ejection electro-hydraulic unit. When performing the injection action, the servo motor assembly 11 receives the injection pressure and injection speed instructions sent by the controller, the servo motor assembly 11 runs at a high speed, the control end YA05 of the second electro-hydraulic valve 32 is energized, the hydraulic oil is connected from P1 of the first electro-hydraulic valve 31 to B1, and is quickly filled into the injection unit 2. The injection unit 2 sends out an injection action, pushing the sol screw to perform a rapid linear motion, and quickly injecting the plastic into the mold.

[0034] Preferably, the control unit 4 includes a proportional pressure valve 41 , an injection pressure control electromagnetic directional valve 42 and an injection pressure control cartridge valve 43 .

[0035] The oil port P3 of the injection pressure control electromagnetic directional valve 42 is connected to the control port X1 of the injection pressure control cartridge valve 43, the oil port T3 of the injection pressure control electromagnetic directional valve 42 is connected to the input end of the oil supply unit 1, the oil port A3 of the injection pressure control electromagnetic directional valve 42 is connected to the proportional pressure valve 41, and the oil port B3 of the injection pressure control electromagnetic directional valve 42 is connected to the input end of the oil supply unit 1.

[0036] The oil port B5 of the injection pressure control cartridge valve 43 is communicated with the input end of the oil supply unit 1 , and the oil port A5 of the injection pressure control cartridge valve 43 is communicated with the oil inlet of the injection unit 2 .

[0037] With this structure, during the injection action, the control end YA24 of the injection pressure control cartridge valve 43 is energized, and the proportional pressure valve 41 is given a current signal of the same injection pressure by the controller, so that the proportional pressure valve 41 works at a constant position, thereby controlling the opening degree of the injection pressure control cartridge valve 43. At this time, the servo motor assembly 11 outputs as a constant source of injection power, and its pressure is not controlled by other signals. Its motor speed and oil pressure are both regulated by the proportional pressure valve 41.

[0038] Preferably, the control unit 4 further includes a sol back pressure valve 44 , a sol solenoid directional valve 45 and a sol cartridge valve 46 .

[0039] The sol back pressure valve 44 is arranged in a pipeline between the oil port B3 of the injection pressure control electromagnetic directional valve 42 and the input end of the oil supply unit 1 .

[0040] The oil port P4 of the sol solenoid directional valve 45 is connected to the oil port A6 of the sol cartridge valve 46, the oil port A6 of the sol cartridge valve 46 is connected to the output end of the oil supply unit 1, the oil port T4 of the sol solenoid directional valve 45 is connected to the input end of the oil supply unit 1, and the oil port A4 of the sol solenoid directional valve 45 is connected to the control port X2 of the sol cartridge valve 46.

[0041] The oil port B6 of the sol cartridge valve 46 is communicated with the oil inlet of the motor unit 5 .

[0042] With this structure, when the sol action is performed, the control end YA06 of the sol electromagnetic directional valve 45 is energized, and the sol cartridge valve 46 is opened, so that the motor unit 5 rotates to drive the sol screw of the injection unit 2 to eat the material and perform the plasticization work. At the same time, the control end YA23 of the injection pressure control electromagnetic directional valve 42 is energized, and the opening degree of the injection pressure control cartridge valve 43 is adjusted through the sol back pressure valve 44, thereby controlling the sol back pressure during the sol, so that the extrusion and density of the plastic remain consistent. This structure solves the problem of injection pressure stability, and is compatible with adjusting the back pressure of the sol action, saving manufacturing costs.

[0043] Preferably, the control unit 4 further includes a sol back pressure gauge 47 , and the sol back pressure gauge 47 is connected to the oil port B3 of the injection pressure control electromagnetic directional valve 42 .

[0044] With this structure, in order to conveniently and intuitively observe the back pressure, a sol back pressure gauge 47 is provided at the oil port B3 of the injection pressure control electromagnetic directional valve 42 .

[0045] A long injection pressure-maintaining method comprises the following steps:

[0046] Preparatory steps: Adjust the maximum oil pressure safety pressure.

[0047] Preset step: adjust the injection pressure of the proportional pressure valve 41.

[0048] Injection step: receiving the injection pressure instruction and the injection speed instruction, and injecting hydraulic oil into the injection unit 2, and the injection unit 2 injects the plastic into the mold.

[0049] Sol step: receiving the sol instruction, the motor unit 5 drives the sol screw of the injection unit 2 to sol, and the control unit 4 adjusts the sol back pressure.

[0050] By adopting this method, the injection unit 2, the reversing unit 3, the control unit 4 and the motor unit 5 cooperate to ensure the stability and continuity of the injection pressure, reduce the loss of injection pressure, increase the injection speed, and make the density of the plastic more stable when it is injected into the mold, thereby ensuring the quality of the product.

[0051] Preferably, in the injection step, the servo motor assembly 11 receives the injection pressure instruction and the injection speed instruction, the control terminal YA05 of the reversing unit 3 is energized, the reversing unit 3 connects the oil port P1 and the oil port B1, and hydraulic oil is injected into the injection unit 2. The injection unit 2 pushes the sol screw to inject the plastic into the mold.

[0052] By adopting this method, the injection pressure control electromagnetic directional valve 42, the proportional pressure valve 41 and the injection pressure control cartridge valve 43 cooperate to keep the servo motor assembly 11 at a constant power output, and the proportional pressure valve 41 controls the speed of the servo motor assembly 11 and the oil pressure of the hydraulic oil.

[0053] Preferably, in the sol step, a sol instruction is received, the control end YA06 of the sol solenoid directional valve 45 is energized, the sol cartridge valve 46 is opened, the motor unit 5 rotates to drive the sol screw of the injection unit 2 to sol, the control end YA23 of the injection pressure control solenoid directional valve 42 is energized, and the opening degree of the injection pressure control cartridge valve 43 is adjusted through the sol back pressure valve 44, thereby adjusting the sol back pressure.

[0054] By adopting this method, the opening degree of the injection pressure control cartridge valve 43 is adjusted through the cooperation of the sol electromagnetic directional valve 45, the sol cartridge valve 46 and the sol back pressure valve 44, thereby controlling the sol back pressure during the sol, so that the extrusion and density of the plastic are consistent.

[0055] The technical principle of the present invention is described above in conjunction with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations herein, those skilled in the art can associate other specific implementations of the present invention without paying creative labor, and these methods will fall within the scope of protection of the present invention.

Claims

1. A pressure-maintaining injection system, characterized in that: It includes oil supply unit, injection unit, reversing unit, control unit and motor unit; The output end and the input end of the oil supply unit are respectively connected to one of the oil circuits of the reversing unit, and the output end and the input end of the injection unit are respectively connected to the other oil circuit of the reversing unit; The input end of the control unit is communicated with the output end of the oil supply unit, the first output end of the control unit is communicated with the input end of the injection unit, the second output end of the control unit is communicated with the oil inlet of the motor unit, the oil outlet of the motor unit is communicated with the input end of the oil supply unit; the output end of the motor unit is connected to the injection unit.

2. A pressure-maintaining injection system according to claim 1, characterized in that: The oil supply unit includes a servo motor assembly, a total pressure control valve and a pressure sensor. The input end of the servo motor assembly is connected to the oil tank through a pipeline, and the output end of the servo motor assembly is connected to the input end of the reversing unit through a pipeline. The total pressure control valve and the pressure sensor are both arranged in the pipeline between the servo motor assembly and the reversing unit.

3. A pressure-maintaining injection system according to claim 2, characterized in that: It also includes a total pressure gauge, which is arranged in the pipeline between the servo motor assembly and the reversing unit.

4. A pressure-maintaining injection system according to claim 1, characterized in that: The reversing unit includes a first electro-hydraulic valve and a second electro-hydraulic valve, wherein the oil port P1 of the first electro-hydraulic valve is connected to the output end of the oil supply unit, the oil port T1 of the first electro-hydraulic valve is connected to the input end of the oil supply unit, the oil port A1 of the first electro-hydraulic valve is connected to the oil outlet of the injection unit, and the oil port B1 of the first electro-hydraulic valve is connected to the oil inlet of the injection unit; One electromagnetic port of the first electro-hydraulic valve is connected to the oil port A2 of the second electro-hydraulic valve, another electromagnetic port of the first electro-hydraulic valve is connected to the oil port B2 of the second electro-hydraulic valve, the oil port P2 of the second electro-hydraulic valve is connected to the output end of the oil supply unit, and the oil port T2 of the second electro-hydraulic valve is connected to the input end of the oil supply unit.

5. A pressure-maintaining injection system according to claim 1, characterized in that: The control unit includes a proportional pressure valve, an injection pressure control solenoid directional valve and an injection pressure control cartridge valve; The oil port P3 of the injection pressure control electromagnetic directional valve is connected to the control port X1 of the injection pressure control cartridge valve, the oil port T3 of the injection pressure control electromagnetic directional valve is connected to the input end of the oil supply unit, the oil port A3 of the injection pressure control electromagnetic directional valve is connected to the proportional pressure valve, and the oil port B3 of the injection pressure control electromagnetic directional valve is connected to the input end of the oil supply unit; The oil port B5 of the injection pressure control cartridge valve is communicated with the input end of the oil supply unit, and the oil port A5 of the injection pressure control cartridge valve is communicated with the oil inlet of the injection unit.

6. A pressure-maintaining injection system according to claim 5, characterized in that: The control unit also includes a sol back pressure valve, a sol solenoid directional valve and a sol cartridge valve; The sol back pressure valve is arranged in the pipeline between the oil port B3 of the injection pressure control electromagnetic directional valve and the input end of the oil supply unit; The oil port P4 of the sol solenoid directional valve is connected to the oil port A6 of the sol cartridge valve, the oil port A6 of the sol cartridge valve is connected to the output end of the oil supply unit, the oil port T4 of the sol solenoid directional valve is connected to the input end of the oil supply unit, and the oil port A4 of the sol solenoid directional valve is connected to the control port X2 of the sol cartridge valve; The oil port B6 of the sol cartridge valve is communicated with the oil inlet of the motor unit.

7. A pressure-maintaining injection system according to claim 5, characterized in that: The control unit further comprises a sol back pressure gauge, which is connected to the oil port B3 of the injection pressure control electromagnetic directional valve.

8. A long injection pressure holding method, characterized in that: Using the pressure-maintaining injection system according to any one of claims 1 to 7 comprises the following steps: Preparation steps: Adjust the maximum oil pressure safety pressure; Preset steps: adjust the injection pressure of the proportional pressure valve; Injection step: receiving the injection pressure command and the injection speed command, and injecting hydraulic oil into the injection unit, and the injection unit injects the plastic into the mold; Sol step: receiving the sol instruction, the motor unit drives the sol screw of the injection unit to sol, and the control unit adjusts the sol back pressure.

9. A long injection pressure holding method according to claim 8, characterized in that: In the injection step, the servo motor assembly receives the injection pressure command and the injection speed command, the control terminal YA05 of the reversing unit is energized, the reversing unit connects the oil port P1 and the oil port B1, and hydraulic oil is injected into the injection unit. The injection unit pushes the sol screw to inject the plastic into the mold.

10. A long injection pressure holding method according to claim 8, characterized in that: In the sol step, a sol instruction is received, the control end YA06 of the sol solenoid directional valve is energized, the sol cartridge valve is opened, the motor unit rotates to drive the sol screw of the injection unit to sol, the control end YA23 of the injection pressure control solenoid directional valve is energized, and the opening degree of the injection pressure control cartridge valve is adjusted through the sol back pressure valve, thereby adjusting the sol back pressure.

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