Injection molding system and full hydraulic injection molding machine

Abstract

The present invention discloses an injection system and a fully hydraulic injection molding machine, comprising an oil supply unit, a first control unit, a second control unit, a pressurizing unit, a mold locking unit and a glue injection unit; the oil supply unit comprises an oil tank, a main pump and an auxiliary pump; the input end of the main pump is connected to the oil tank, the output end of the main pump is connected to the input end of the glue injection unit, and the output end of the glue injection unit is connected to the oil tank; the first control unit is arranged in a pipeline between the output end of the main pump and the glue injection unit; the input end of the pressurizing unit is arranged in a pipeline between the first control unit and the glue injection unit; the output end of the pressurizing unit is connected to the input end of the mold locking unit, and the output end of the mold locking unit is connected to the oil tank; the present application aims to provide an injection system and a fully hydraulic injection molding machine, which can maintain injection pressure, reduce the internal stress of the product, and improve the production quality.

Description

Technical Field

[0001] The present invention relates to the technical field of injection molding machines, and in particular to an injection molding system and a full hydraulic injection molding machine. Background Art

[0002] Ordinary injection molding machines first lock the mold and then inject the molten plastic into the mold cavity. The molding process is: mold closing, locking, injection, pressure holding, plasticizing, unloading, mold opening, and ejection. The internal stress of the products produced is usually relatively large and cannot meet the requirements of low-stress and high-precision products.

[0003] Injection molding technology is a technology of compression molding after injection molding. It is a combined molding technology of injection molding and compression molding, also known as secondary mold injection molding. It has two stages: injection molding and compression. The molten material is first pushed into the mold cavity by the screw, and then the molten material injected into the mold cavity is compressed. This compression is very important and helps to reduce the residual stress in the plastic part, so that the molded plastic part has a high precision. Summary of the invention

[0004] The purpose of the present invention is to provide an injection system and a full hydraulic injection molding machine, which can maintain injection pressure, reduce the internal stress of the product and improve the production quality.

[0005] To achieve this purpose, the present invention adopts the following technical solutions: an injection system, comprising an oil supply unit, a first control unit, a second control unit, a pressurizing unit, a mold locking unit and an injection unit; the oil supply unit comprises an oil tank, a main pump and an auxiliary pump; the input end of the main pump is communicated with the oil tank, the output end of the main pump is communicated with the input end of the injection unit, and the output end of the injection unit is communicated with the oil tank; the first control unit is arranged in a pipeline between the output end of the main pump and the injection unit; the input end of the pressurizing unit is arranged in a pipeline between the first control unit and the injection unit; the output end of the pressurizing unit is communicated with the input end of the mold locking unit, and the output end of the mold locking unit is communicated with the oil tank; the auxiliary pump is electrically connected to the main pump, the output end of the auxiliary pump is communicated with the input end of the pressurizing unit, and the second control unit is arranged in a pipeline between the output end of the auxiliary pump and the oil tank.

[0006] Preferably, the first control unit is a PQ control valve, a flow control end of the PQ control valve is connected to a pipeline between the output end of the main pump and the injection unit, and a pressure control end of the PQ control valve is connected to a pipeline between the output end of the main pump and the oil tank.

[0007] Preferably, the second control unit is an electromagnetic overflow valve, and the electromagnetic overflow valve is arranged in a pipeline between the output end of the auxiliary pump and the oil tank.

[0008] Preferably, the injection unit comprises an injection cylinder and an injection valve, the oil port P of the injection valve is connected to the output end of the main pump, the oil port T of the injection valve is connected to the oil tank, and the oil ports A and B of the injection valve are respectively connected to the injection cylinder.

[0009] Preferably, it also includes an injection pressure switching valve and a fourth one-way valve, the input end of the injection pressure switching valve is connected to the pipeline between the first control unit and the injection unit, the fourth one-way valve is arranged at the output end of the auxiliary pump, and the output end of the injection pressure switching valve is connected to the pipeline between the fourth one-way valve and the boosting unit.

[0010] Preferably, the boosting unit includes a sixth one-way valve, a seventh one-way valve, a boosting valve and a boosting cylinder; the input end of the sixth one-way valve is connected to the output end of the main pump, the output end of the sixth one-way valve is connected to the control end of the boosting valve, the input of the seventh one-way valve is connected to the output end of the main pump, the output end of the seventh one-way valve is connected to the input end of the boosting cylinder, one output end of the boosting cylinder is connected to the input end of the boosting valve, and the output end of the boosting valve is connected to the oil tank; the other output end of the boosting cylinder is connected to the clamping unit.

[0011] Preferably, the locking unit includes a locking valve, a pressure sensor and a locking cylinder; the other output end of the booster cylinder is connected to the oil port P of the locking valve, the oil port T of the locking valve is connected to the oil tank, the oil port A and the oil port B of the locking valve are respectively connected to the locking cylinder, and the pressure sensor is connected to the pipeline between the locking valve and the locking cylinder.

[0012] A fully hydraulic injection molding machine comprises a bracket, a movable platen and a fixed platen, a piston rod is arranged between the bracket and the fixed platen, a plurality of piston rods are provided, a piston is provided on the piston rod sleeve, a cylinder body is provided on the outer sleeve of the piston rod, one end of the cylinder body is connected to the movable platen, and the other end of the cylinder body is movably sealed and connected to the piston rod; the cylinder body is provided with an oil inlet and an oil outlet, and the oil inlet and the oil outlet are respectively located on both sides of the piston; a mold shifting mechanism is provided between the movable platen and the bracket.

[0013] Preferably, it also includes a rear pressure plate, a rear guide sleeve and a rear end cover, the rear guide sleeve is movably mounted on the piston rod, the rear end cover is mounted on the periphery of the rear guide sleeve, the rear pressure plate is movably mounted on the periphery of the piston rod, one end of the rear end cover is connected to the rear pressure plate, and the other end of the rear end cover is connected to the cylinder body; the oil inlet is arranged on the rear end cover.

[0014] Preferably, it also includes a front end cover, a cartridge valve, a gasket and a front guide sleeve, the movable template is provided with a mounting groove, the front guide sleeve is arranged in the mounting groove, the inner wall of the front guide sleeve is movably connected to the piston rod, one end of the front end cover is connected to the cylinder body, and the other end of the front end cover is connected to the mounting groove, the gasket is clamped between the front end cover and the front guide sleeve, the cartridge valve is arranged between the inner wall of the front end cover and the outer wall of the piston rod; the oil outlet is arranged on the front end cover.

[0015] The present application adopts the above-mentioned structure, and adjusts the pressure or flow of the pipeline through the first control unit and the second control unit to realize the processes of mold closing, low-pressure locking, injection, molding, pressure holding, plasticization, mold opening, and ejection. When the injection and pressure holding are completed, the locking force is reduced to 30% of the original, and gradually reduced to zero before opening the mold, thereby effectively reducing the internal stress of the injection molded product, avoiding vibration when opening the mold, and ensuring the smoothness of the injection molded product. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings further illustrate the present invention, but the contents in the accompanying drawings do not constitute any limitation to the present invention.

[0017] Figure 1 It is a structural schematic diagram of the injection pressure system of the present invention;

[0018] Figure 2 It is a structural schematic diagram of the injection molding machine of the present invention.

[0019] Among them: oil supply unit 1, oil tank 1a, main pump 1b, auxiliary pump 1c, first control unit 2, second control unit 3, boosting unit 4, sixth one-way valve 4a, seventh one-way valve 4b, boosting valve 4c, boosting cylinder 4d, clamping unit 5, clamping valve 5a, pressure sensor 5b, clamping cylinder 5c, injection unit 6, injection cylinder 6a, injection valve 6b, injection pressure switching valve 7, fourth one-way valve 8, bracket 9, movable template 10, fixed template 11, piston rod 12, piston 13, cylinder body 14, oil inlet 14a, oil outlet 14b, mold shifting mechanism 15, rear pressure plate 16, rear guide sleeve 17, rear end cover 18, front end cover 19, cartridge valve 20, front guide sleeve 21. DETAILED DESCRIPTION

[0020] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0021] See also Figure 1 and Figure 2 As shown, an injection system of this embodiment includes an oil supply unit 1, a first control unit 2, a second control unit 3, a pressurizing unit 4, a mold locking unit 5 and a glue injection unit 6.

[0022] The oil supply unit 1 includes an oil tank 1a, a main pump 1b and an auxiliary pump 1c.

[0023] The input end of the main pump 1b is communicated with the oil tank 1a, the output end of the main pump 1b is communicated with the input end of the injection unit 6, and the output end of the injection unit 6 is communicated with the oil tank 1a;

[0024] The first control unit 2 is disposed in a pipeline between the output end of the main pump 1 b and the injection unit 6 .

[0025] The input end of the boosting unit 4 is arranged in the pipeline between the first control unit 2 and the injection unit 6 .

[0026] The output end of the boosting unit 4 is communicated with the input end of the mold clamping unit 5 , and the output end of the mold clamping unit 5 is communicated with the oil tank 1 a .

[0027] The auxiliary pump 1c is electrically connected to the main pump 1b, the output end of the auxiliary pump 1c is connected to the input end of the boosting unit 4, and the second control unit 3 is arranged in a pipeline between the output end of the auxiliary pump 1c and the oil tank 1a.

[0028] The oil supply unit 1 also includes a motor, which drives the main pump 1b and the auxiliary pump 1c to work. The pressure and flow of the main pump 1b are adjusted by the first control unit 2, which is responsible for controlling all the actions of the whole machine. The auxiliary pump 1c is pressure-regulated by the second control unit 3. The hydraulic oil pressure is increased by the booster unit 4, and the hydraulic oil enters the clamping unit 5. The clamping unit 5 reaches the preset pressure value a, completes the clamping action, and the mold is tightly attached. During compression molding, the auxiliary pump 1c outputs high-pressure oil into the clamping unit 5. The clamping unit 5 reaches the preset pressure value b, and the main pump 1b stops supplying oil to the clamping unit 5. At the same time, it can continue to provide power to the injection unit 6 for feeding, thereby realizing injection molding and compression molding at the same time.

[0029] With this structure, the pressure or flow of the pipeline is adjusted by the first control unit 2 and the second control unit 3 to complete the processes of mold closing, low-pressure locking, injection, compression molding, pressure holding, plasticization, mold opening, and ejection. When the injection and pressure holding are completed, the locking force is reduced to 30% of the original value and gradually reduced to zero before the mold is opened, thereby effectively reducing the internal stress of the injection molded product, avoiding vibration when opening the mold, and ensuring the smoothness of the injection molded product.

[0030] Preferably, the first control unit 2 is a PQ control valve, a flow control end of the PQ control valve is connected to a pipeline between the output end of the main pump 1b and the injection unit 6, and a pressure control end of the PQ control valve is connected to a pipeline between the output end of the main pump 1b and the oil tank 1a.

[0031] The PQ control valve is indicated by the symbol V1 in the figure. The PQ control valve has a pressure-flow compound control function. When controlling pressure, the flow valve function is reduced, and when controlling flow, the pressure valve function is reduced. The PQ control valve adjusts the action of the entire system by adjusting the pressure and flow of the main pump 1b output pipeline and loop.

[0032] Preferably, the second control unit 3 is an electromagnetic overflow valve, and the electromagnetic overflow valve is arranged in a pipeline between the output end of the auxiliary pump 1c and the oil tank 1a.

[0033] The electromagnetic overflow valve is indicated by the symbol V2 in the figure. The pressure control end of the electromagnetic overflow valve is connected to the oil inlet of the valve body, and the oil outlet of the valve body is connected to the oil tank 1a. During die pressing, the electromagnetic overflow valve is energized, and the auxiliary pump 1c outputs high-pressure oil into the clamping unit 5 to reach the die pressing set value. With this structure, the pressure of the output pipeline of the auxiliary pump 1c can be adjusted by the second control unit 3, and the control is simple.

[0034] Preferably, the injection unit 6 includes an injection cylinder 6a and an injection valve 6b, the oil port P of the injection valve 6b is connected to the output end of the main pump 1b, the oil port T of the injection valve 6b is connected to the oil tank 1a, and the oil port A and the oil port B of the injection valve 6b are respectively connected to the injection cylinder 6a.

[0035] The injection valve 6b is indicated by the symbol V5 in the figure. With this structure, the injection valve 6b and the injection cylinder 6a cooperate to perform the injection action.

[0036] Preferably, it also includes an injection pressure switching valve 7 and a fourth one-way valve 8, the input end of the injection pressure switching valve 7 is connected to the pipeline between the first control unit 2 and the injection unit 6, the fourth one-way valve 8 is arranged at the output end of the auxiliary pump 1c, and the output end of the injection pressure switching valve 7 is connected to the pipeline between the fourth one-way valve 8 and the boosting unit 4.

[0037] The fourth one-way valve 8 is indicated by the symbol V4 in the figure, and the auxiliary pump 1c, the injection pressure switching valve 7 and the fourth one-way valve 8 cooperate to complete the compression molding process.

[0038] Preferably, the boosting unit 4 includes a sixth one-way valve 4a, a seventh one-way valve 4b, a boosting valve 4c and a boosting cylinder 4d.

[0039] The input end of the sixth one-way valve 4a is connected to the output end of the main pump 1b, the output end of the sixth one-way valve 4a is connected to the control end of the boosting valve 4c, the input of the seventh one-way valve 4b is connected to the output end of the main pump 1b, the output end of the seventh one-way valve 4b is connected to the input end of the boosting cylinder 4d, one output end of the boosting cylinder 4d is connected to the input end of the boosting valve 4c, and the output end of the boosting valve 4c is connected to the oil tank 1a.

[0040] The other output end of the boost cylinder 4 d is communicated with the mold clamping unit 5 .

[0041] The sixth one-way valve 4a is indicated by the symbol V6 in the figure, and the seventh one-way valve 4b is indicated by the symbol V7 in the figure. The hydraulic oil output by the auxiliary pump 1c passes through the fourth one-way valve 8 and is transported to the sixth one-way valve 4a and the seventh one-way valve 4b through the pipeline. The booster valve 4c is energized, and the hydraulic oil enters the booster cylinder 4d. The booster cylinder 4d outputs the hydraulic oil with increased pressure, and enters the clamping cylinder 5c after passing through the clamping valve 5a until the pressure reaches the preset pressure value, thereby completing the secondary die pressing operation. This action can be repeated multiple times according to the working conditions and product requirements.

[0042] Preferably, the locking unit 5 includes a locking valve 5a, a pressure sensor 5b and a locking cylinder 5c; the other output end of the boost cylinder 4d is connected to the oil port P of the locking valve 5a, the oil port T of the locking valve 5a is connected to the oil tank 1a, the oil port A and the oil port B of the locking valve 5a are respectively connected to the locking cylinder 5c, and the pressure sensor 5b is connected to the pipeline between the locking valve 5a and the locking cylinder 5c.

[0043] With this structure, the clamping valve 5a and the pressure sensor 5b cooperate to adjust the oil inlet or outlet of the clamping cylinder 5c, thereby controlling the clamping cylinder 5c to advance or retreat, thereby completing the clamping action.

[0044] A fully hydraulic injection molding machine comprises a bracket 9, a movable platen 10 and a fixed platen 11, a piston rod 12 is arranged between the bracket 9 and the fixed platen 11, a plurality of piston rods 12 are provided, a piston 13 is sleeved on the piston rod 12, a cylinder body 14 is sleeved on the outer periphery of the piston rod 12, one end of the cylinder body 14 is connected to the movable platen 10, and the other end of the cylinder body 14 is movably and sealedly connected to the piston rod 12.

[0045] The cylinder body 14 is provided with an oil inlet 14 a and an oil outlet 14 b , and the oil inlet 14 a and the oil outlet 14 b are respectively located on two sides of the piston 13 .

[0046] A mold shifting mechanism 15 is provided between the movable mold plate 10 and the bracket 9 .

[0047] The mold shifting mechanism 15 uses a mold shifting oil cylinder, preferably two in number, for driving the movable mold plate 10 to move and perform mold opening and closing actions. Preferably, four piston rods 12 are provided.

[0048] With this structure, the piston rod 12 is fixed by the support 9 and the fixed template 11. The piston rod 12, the piston 13 and the cylinder body 14 cooperate with each other, and the high-pressure oil enters the cylinder body 14, so that the high-pressure clamping action can be completed. During the clamping process, the pressure in the cylinder body 14 is feedback-regulated by the pressure sensor 5b. The clamping force can be accurately set by the computer equipment, and the signal of the pressure sensor 5b can also be directly transmitted to the computer equipment. It will not be affected by factors such as ambient temperature and has high repeatability.

[0049] Preferably, it also includes a rear pressure plate 16, a rear guide sleeve 17 and a rear end cover 18, the rear guide sleeve 17 is movably sleeved on the piston rod 12, the rear end cover 18 is sleeved on the periphery of the rear guide sleeve 17, the rear pressure plate 16 is movably sleeved on the periphery of the piston rod 12, one end of the rear end cover 18 is connected to the rear pressure plate 16, and the other end of the rear end cover 18 is connected to the cylinder body 14.

[0050] The oil inlet 14 a is disposed on the rear end cover 18 .

[0051] This structure ensures that the rear end of the cylinder body 14 and the piston rod 12 are kept in a movable seal.

[0052] Preferably, it also includes a front end cover 19, a cartridge valve 20, a gasket and a front guide sleeve 21, the movable template 10 is provided with a mounting groove, the front guide sleeve 21 is arranged in the mounting groove, the inner wall of the front guide sleeve 21 is movably connected to the piston rod 12, one end of the front end cover 19 is connected to the cylinder body 14, and the other end of the front end cover 19 is connected to the mounting groove, the gasket is clamped between the front end cover 19 and the front guide sleeve 21, and the cartridge valve 20 is arranged between the inner wall of the front end cover 19 and the outer wall of the piston rod 12.

[0053] The oil outlet 14 b is disposed on the front end cover 19 .

[0054] This structure ensures that the front end of the cylinder body 14 and the piston rod 12 are kept in a movable seal.

[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. An injection system, characterized in that: It includes an oil supply unit, a first control unit, a second control unit, a pressurizing unit, a mold locking unit and a glue injection unit; The oil supply unit includes an oil tank, a main pump and an auxiliary pump; The input end of the main pump is communicated with the oil tank, the output end of the main pump is communicated with the input end of the injection unit, and the output end of the injection unit is communicated with the oil tank; The first control unit is arranged in a pipeline between the output end of the main pump and the injection unit; The input end of the boost unit is arranged in the pipeline between the first control unit and the injection unit; The output end of the boosting unit is connected to the input end of the mold clamping unit, and the output end of the mold clamping unit is connected to the oil tank; The auxiliary pump is electrically connected to the main pump, the output end of the auxiliary pump is communicated with the input end of the boosting unit, and the second control unit is arranged in a pipeline between the output end of the auxiliary pump and the oil tank; The first control unit is a PQ control valve, the flow control end of the PQ control valve is connected to the pipeline between the output end of the main pump and the injection unit, and the pressure control end of the PQ control valve is connected to the pipeline between the output end of the main pump and the oil tank; The second control unit is an electromagnetic overflow valve, and the electromagnetic overflow valve is arranged in a pipeline between the output end of the auxiliary pump and the oil tank.

2. An injection system according to claim 1, characterized in that: The injection unit includes an injection cylinder and an injection valve, the oil port P of the injection valve is connected to the output end of the main pump, the oil port T of the injection valve is connected to the oil tank, and the oil ports A and B of the injection valve are respectively connected to the injection cylinder.

3. An injection system according to claim 1, characterized in that: It also includes an injection pressure switching valve and a fourth one-way valve, the input end of the injection pressure switching valve is connected to the pipeline between the first control unit and the injection unit, the fourth one-way valve is arranged at the output end of the auxiliary pump, and the output end of the injection pressure switching valve is connected to the pipeline between the fourth one-way valve and the boosting unit.

4. An injection pressure system according to claim 1, characterized in that: The boosting unit includes a sixth one-way valve, a seventh one-way valve, a boosting valve and a boosting oil cylinder; The input end of the sixth one-way valve is communicated with the output end of the main pump, the output end of the sixth one-way valve is communicated with the control end of the boosting valve, the input of the seventh one-way valve is communicated with the output end of the main pump, the output end of the seventh one-way valve is communicated with the input end of the boosting cylinder, one output end of the boosting cylinder is communicated with the input end of the boosting valve, and the output end of the boosting valve is communicated with the oil tank; The other output end of the booster cylinder is communicated with the mold locking unit.

5. An injection system according to claim 4, characterized in that: The clamping unit includes a clamping valve, a pressure sensor and a clamping cylinder; the other output end of the booster cylinder is connected to the oil port P of the clamping valve, the oil port T of the clamping valve is connected to the oil tank, the oil port A and the oil port B of the clamping valve are respectively connected to the clamping cylinder, and the pressure sensor is connected to the pipeline between the clamping valve and the clamping cylinder.

6. A fully hydraulic injection molding machine, using an injection molding system as described in any one of claims 1 to 5, comprising a bracket, a movable mold plate and a fixed mold plate, characterized in that: A piston rod is arranged between the bracket and the fixed platen, and a plurality of piston rods are provided. The piston rod sleeve is provided with a piston, and a cylinder body is arranged on the outer sleeve of the piston rod. One end of the cylinder body is connected to the movable platen, and the other end of the cylinder body is movably and sealably connected to the piston rod; The cylinder body is provided with an oil inlet and an oil outlet, and the oil inlet and the oil outlet are respectively located on both sides of the piston; A mold shifting mechanism is arranged between the movable mold plate and the bracket.

7. A fully hydraulic injection molding machine according to claim 6, characterized in that: It also includes a rear pressure plate, a rear guide sleeve and a rear end cover, wherein the rear guide sleeve is movably sleeved on the piston rod, the rear end cover is sleeved on the periphery of the rear guide sleeve, the rear pressure plate is movably sleeved on the periphery of the piston rod, one end of the rear end cover is connected to the rear pressure plate, and the other end of the rear end cover is connected to the cylinder body; The oil inlet is arranged on the rear end cover.

8. A fully hydraulic injection molding machine according to claim 7, characterized in that: It also includes a front end cover, a cartridge valve, a gasket and a front guide sleeve, the movable plate is provided with a mounting groove, the front guide sleeve is arranged in the mounting groove, the inner wall of the front guide sleeve is movably connected to the piston rod, one end of the front end cover is connected to the cylinder body, the other end of the front end cover is connected to the mounting groove, the gasket is clamped between the front end cover and the front guide sleeve, and the cartridge valve is arranged between the inner wall of the front end cover and the outer wall of the piston rod; The oil outlet is arranged on the front end cover.

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