CN102285060B - Water-assisted molding process and constant pressure water-assisted injection molding equipment - Google Patents

Water-assisted molding process and constant pressure water-assisted injection molding equipment Download PDF

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CN102285060B
CN102285060B CN 201110207388 CN201110207388A CN102285060B CN 102285060 B CN102285060 B CN 102285060B CN 201110207388 CN201110207388 CN 201110207388 CN 201110207388 A CN201110207388 A CN 201110207388A CN 102285060 B CN102285060 B CN 102285060B
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pressure
water
valve
injection
high
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CN 201110207388
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CN102285060A (en
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韩国海
何萍
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韩国海
何萍
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Abstract

The invention discloses a water-assisted molding process and constant pressure water-assisted injection molding equipment and aims to realize stable water injection and pressure maintenance and improve the quality of plastic parts. The equipment comprises an injection molding machine controller, a hydraulic control telescopic gas needle and a water needle, wherein the water needle is connected with a gas injection pressure closed-loop control circuit, a water injection pressure closed-loop control circuit and a depressurization closed-loop control circuit respectively; and the hydraulic control telescopic gas needle is connected with a compressed air drainage unit. The water-assisted molding process comprises the following steps of: a, injecting a plastic melt into a die cavity; b, injecting a little nitrogen into the plastic melt; c, injecting high-pressure water into the rear part of the nitrogen; d, injecting the high-pressure water into the die cavity and maintaining the pressure; e, after cooling, curing and molding, draining the injected water and reducing the pressure; f, draining the injected water completely; g, ejecting a plastic part; and h, entering the next period. Compared with the prior art, the equipment is provided with a gas pressure supercharger and a water pressure generating device to fulfill the aims of realizing stable water injection and pressure maintenance and reducing the product development and production cost.

Description

Water shaping technology and constant voltage water aided injection forming device

Technical field

The present invention relates to a kind of injection molding technique and equipment, a kind of gas assisted molding technology of utilizing particularly, in conjunction with the water shaping characteristics, be medium with gas and water, automatically control pressure, the flow that injects the plastic internal water after the supercharging, plastics are made water shaping technology and the constant voltage water aided injection forming device of hollow product.

Background technology

For many years, people are exploring the forming processing technology of improving plasthetics always.The seventies in 20th century, be that gas assisted molding technology that purpose grows up just is suggested and progressively is applied to reduce warpage, to avoid indenture and cut down the consumption of raw materials, we have also done some researchs in this field, as patent of invention: ZL:200510121110.4.In recent years, because the compressibility of some shortcomings, particularly gas that the gas assisted molding technology exposes in using and pyroconductivity, specific heat capacity are low, when the big long tube based article of moulding sectional area, easily cause plastic parts long cool time, production efficiency is low, and inwall easily produces defectives such as bubble.In order to overcome above-mentioned deficiency, the water aided injection forming technology has grown up on the gas assisted molding basis, its essential difference is to replace with liquid water the auxiliary melt flows mold filling of gas (mainly being nitrogen) of gaseous state, water not only viscosity is higher than gas, and the pyroconductivity of water is 40 times of nitrogen, its specific heat capacity also is 4 times of gas, is very beneficial for plasthetics cooling after the melt flows mold filling.

Because the time of water shaping technology development is not long, many technologies and equipment also be in further exploitation, perfect in the middle of.Prior art is mainly utilized the outlet pressure of pressure sensor feedback solenoid-operated proportional pressure-reducing valve, regulates the outlet pressure of this valve by the proportion electro-magnet of controlling this valve, just injects the pressure of water.Yet at present the solenoid-operated proportional pressure-reducing valve during operate as normal, can not reach zero leakage, moreover the response time of this control mode valve is long, reaction is slow under condition of high voltage.And inject the pressure of plastic cement internal water, sealing, the discharge problem that can flow reach specification requirement and injection water moment is the key problem that is related to the success or failure of water shaping technology, in case take place to inject the leakage of water or be ejected on the mould, or inject the pressure of water, the value that flow can not reach setting moment, all can influence the Forming Quality of goods; The adopts pressure sensor feedback accumulator (high pressure water pot just), the inlet pressure of back pressure regulating valve and the high pressure chest output pressure of pressurized cylinder that have, regulate the outlet pressure of this valve, the just pressure of injection moulding water by the proportion electro-magnet of controlling this back pressure regulating valve.Can back pressure regulating valve reach zero leakage no matter cut at present, and this control mode can only push plastic parts by piston with certain volume water under high pressure in the high pressure chest of pressurized cylinder at most in each molding cycle.Because the volume of the high pressure chest of pressurized cylinder is restricted, the pressure that injects water depends on the volume of goods and the ratio of the volume of the high pressure chest of pressurized cylinder.Because this scheme can not accurately be adjusted pressure, this similar constant volume gas assisted molding method has been eliminated already; Practice confirm injection coolant-temperature gage that water shaping uses generally between 10~80 ℃ (be normal-temperature water just can) can be suitable for, the equipment that has is complexity too, has also taked unnecessary closed loop accurately to control to water temperature, makes the equipment manufacturing cost costliness.Also having present water shaping technology all is only to be medium with water, water directly contacts with the plastic cement melt, because the pyroconductivity of water and specific heat capacity are than the height of gas, in the hollow molding process, though water is very beneficial for the plasthetics cooling, but can cause the too fast cooling curing of plastic cement melt, be unfavorable for the melt flows mold filling on the contrary.

Summary of the invention

The purpose of this invention is to provide a kind of water shaping technology and constant voltage water aided injection forming device, the technical problem that solves be problem such as the too fast cooling of melt in the existing water shaping technology, curing and the impact of injection instant water decompression and existing water shaping equipment system response time long, inject the constant and pressure of water volume, flow is uncontrollable and the sealing of injection water, discharge, to the accurate problem such as control of the unnecessary closed loop of water temperature, realize steady water filling and pressurize, improve plastic part quality, reduce product development and production cost.

The present invention is for addressing the above problem the following scheme that adopts: a kind of constant voltage water aided injection forming device, comprise controller of plastic injection molding and be installed in the mould interior telescopic air tube of hydraulic control and liquid drugs injection, described controller of plastic injection molding linker controller, one end of the telescopic air tube of described hydraulic control stretches in spill cavity or the die cavity, one end of described liquid drugs injection stretches in die cavity or the mould runner, described liquid drugs injection also connects gas injection pressure close loop control circuit, water injection pressure close loop control circuit and step-down close loop control circuit respectively, and the telescopic air tube of described hydraulic control connects the compressed air drainage cell.

Gas injection pressure close loop control circuit of the present invention is by the elevated pressure nitrogen source of the gas, the high pressure nitrogen stop valve, the high pressure nitrogen filter, the gas injection high-pressure solenoid valve, the high-voltage electric air valve, pressure sensor and cyclelog are formed, described elevated pressure nitrogen source of the gas is through the high pressure nitrogen stop valve, the high pressure nitrogen filter connects the entrance of gas injection high-pressure solenoid valve, the outlet of gas injection high-pressure solenoid valve is joined through high-voltage electric air valve and liquid drugs injection, liquid drugs injection communicates with plastic cement melt inside in the die cavity, connect pressure sensor between high-voltage electric air valve and the liquid drugs injection, described pressure sensor connects the input of cyclelog, and the output of described cyclelog connects gas injection high-pressure solenoid valve and high-voltage electric air valve respectively; Cyclelog receives the injection end signal that controller of plastic injection molding sends, just water is assisted the technology sign on, pressure sensor feeds back to the outlet pressure of real-time detected high-voltage electric air valve the input of cyclelog, export corresponding signal through the output of cyclelog and control the outlet pressure that gas injection high-pressure solenoid valve and high-voltage electric air valve move to adjust the high-voltage electric air valve respectively, the pressure of nitrogen injection just, liquid drugs injection acts on the plastic cement melt inside in the small amount of nitrogen injection die cavity of pressure controlled system plastic cement melt inside and carries out the preformed of plastic hollow.

Water injection pressure close loop control circuit of the present invention is by high-pressure water, the water under high pressure stop valve, the water under high pressure filter, the water filling accumulator, the water filling high-pressure solenoid valve, the Flow-rate adjustment magnetic valve, the high-voltage electric water valve, pressure sensor and cyclelog are formed, described high-pressure water is through the water under high pressure stop valve, the water under high pressure filter connects the water filling accumulator, the entrance of water filling high-pressure solenoid valve and Flow-rate adjustment magnetic valve, the outlet of water filling high-pressure solenoid valve and Flow-rate adjustment magnetic valve is connected with the entrance of high-voltage electric water valve, the outlet water receiving pin of high-voltage electric water valve, connect pressure sensor between high-voltage electric water valve and the liquid drugs injection, the output of described cyclelog connects the water filling high-pressure solenoid valve respectively, Flow-rate adjustment magnetic valve and high-voltage electric water valve; Pressure sensor feeds back the outlet pressure of real-time detected high-voltage electric water valve to the input of cyclelog, export corresponding signal through the output of cyclelog and control the water filling high-pressure solenoid valve respectively, Flow-rate adjustment magnetic valve and high-voltage electric water valve move to adjust outlet pressure and the flow of high-voltage electric water valve, just inject pressure and the flow of water, liquid drugs injection is with the plastic cement melt inside in the continuous water injection die cavity of pressure and flow rates controlled system, act on plastic cement melt inside, promote a small amount of nitrogen injection in forward position, finish the hollow molding of plastic jointly, pressurize and cooling and shaping process.

Step-down close loop control circuit of the present invention is made up of step-down magnetic valve, filter, water tank, pressure sensor and cyclelog, the described liquid drugs injection that is installed in the mould is connected with the entrance of step-down magnetic valve through filter, the outlet water receiving case of step-down magnetic valve, connect pressure sensor between filter and the liquid drugs injection, the output termination step-down magnetic valve of described cyclelog; Pressure sensor feeds back real-time detected filter inlet pressure to the input of cyclelog, export the inlet pressure that filter is adjusted in corresponding signal controlling step-down magnetic valve draining or exhaust through the output of cyclelog, just inject the pressure of water or nitrogen injection in the die cavity, the water of discharging directly enters water tank, the direct emptying of the nitrogen of discharge.

Compressed air drainage cell of the present invention is made up of compressed air source, compressed air stop valve, compressed-air filter, gas injection magnetic valve, first check valve and cyclelog, the compressed air cutoff valve of described compressed air source, compressed-air filter connect the entrance of gas injection magnetic valve, the outlet of gas injection magnetic valve is connected through the telescopic air tube of first check valve and hydraulic control, can stretching in spill cavity or the die cavity during work, solidifying and setting is the inside of plastic, communicate the output termination gas injection magnetic valve of described cyclelog with plastic inside; Treat that drainage and step-down arrives when setting value, cyclelog is opened through output control gas injection magnetic valve, and compressed air enters the inside of plastic in the die cavity through the telescopic air tube of hydraulic control, and residual injection water is flow back to water tank through the step-down close loop control circuit from the inside of plastic.

High-pressure water of the present invention is provided by the hydraulic pressure generating means, comprise industrial high-pressure hydraulic pump, the pump front filter, safety valve, the pump after-filter, motor, second check valve, pressure is kept and unidirectional combination valve, pressure switch, the water under high pressure accumulator, stop valve, hydraulic controller, water tank, described by motor-driven industrial high-pressure hydraulic pump entrance through pump front filter water receiving case, the outlet of industry high-pressure hydraulic pump is through the pump after-filter, second check valve, pressure is kept with unidirectional combination valve and is connect pressure switch, the entrance of water under high pressure accumulator and stop valve, the outlet of stop valve connects the entrance of water injection pressure close loop control circuit mesohigh water stop valve, provide big flow continuous high-pressure water, the outlet of industry high-pressure hydraulic pump also takes back water tank through safety valve, the input of pressure switch water receiving pressure-controlled device, the output termination motor of hydraulic controller; Pressure switch is used for detecting in real time the pressure of water under high pressure accumulator, when the pressure of water under high pressure accumulator reaches setting value, send the input that feeds back signal to hydraulic controller, by the output control motor action of hydraulic controller, utilize safety valve, pressure to keep with unidirectional combination valve and water under high pressure accumulator and realize variable hydraulic pressure control and guarantee this device security of operation.

Liquid drugs injection of the present invention can also be connected with and vacuumize drainage cell, the described drainage cell that vacuumizes is by vacuum source, vacuum tank, the vacuum transfer valve, vacuum pressure switch, the vacuum electric ball valve, vacuum filter and cyclelog are formed, described vacuum source and vacuum tank, the outlet of vacuum transfer valve is connected, the entrance of vacuum transfer valve is through the vacuum electric ball valve, vacuum filter water receiving pin, be connected to vacuum pressure switch between vacuum transfer valve and the vacuum electric ball valve, vacuum pressure switch connects the input of cyclelog, and the output of cyclelog connects vacuum transfer valve and vacuum electric ball valve respectively; Vacuum pressure switch is used for detecting in real time the evacuated pressure of plastic inside, and send the input that feeds back signal to cyclelog, control vacuum transfer valve and the action of vacuum electric ball valve respectively through the output of cyclelog, residual injection water is drained from plastic inside through liquid drugs injection, vacuum filter.

Elevated pressure nitrogen source of the gas of the present invention is provided by the gas pressure booster of gas assisted molding, and compressed air source is provided by the industrial air compressor, and vacuum source is provided by vavuum pump.

A kind of water shaping technology may further comprise the steps:

A. at first, by controller of plastic injection molding control injection mechanism of injection machine the plastic cement melt is injected in the die cavity, makes to be full of or to be full of substantially the plastic cement melt in the die cavity;

B. cyclelog receives the injection end signal that controller of plastic injection molding sends, just water is assisted the technology sign on, the unlatching of each sequential process in the control water shaping technology, hydraulic control runner stop valve is closed, the small amount of nitrogen that to be controlled automatically time and pressure by the gas injection pressure close loop control circuit is in liquid drugs injection injects die cavity plastic cement melt, force that the hydraulic control overflow shutoff valve of some plastic cement melts through opening enters spill cavity in the die cavity from die cavity, carry out the hollow preformed process of plastic;

C. will carry out the segmentation back of water under high pressure nitrogen injection in liquid drugs injection is injected into die cavity of control automatically to time, pressure and flow by the water injection pressure close loop control circuit, the plastic cement melt flows mold filling that promotion contacts with the nitrogen injection forward position, further force the hydraulic control overflow shutoff valve of some melts through opening from die cavity, to enter spill cavity, finish the hollow molding process of plastic;

D. the water under high pressure that is continued to control automatically time, pressure and flow by the water injection pressure close loop control circuit is in liquid drugs injection is injected into die cavity, guarantee the plastic cement melt in cooling curing, volume contraction process the pressure stability in the die cavity in setting value;

E. after the typing of the plastic cement melt cooling curing in the die cavity, discharged by the injection water in the step-down close loop control circuit control die cavity, the pressure in the die cavity is reduced to setting value;

F. the telescopic air tube of hydraulic control stretches in spill cavity or the die cavity in the plastic of solidifying and setting, by the compressed air drainage cell compressed air is imported in the plastic through the telescopic air tube of hydraulic control, and injection water residual in the plastic is drained; Also can utilize and vacuumize drainage cell injection water residual in the plastic is drained;

G. the die opening and closing mechanism opening mould of controller of plastic injection molding control injection machine ejects plastic;

H. controller of plastic injection molding is controlled the die opening and closing mechanism closed die of injection machine, and the telescopic air tube of hydraulic control, hydraulic control runner stop valve and hydraulic control overflow shutoff valve reset, and enter next injection molding cycle.

The present invention arranges the telescopic air tube of more than one hydraulic control, liquid drugs injection, spill cavity, hydraulic control runner stop valve and hydraulic control overflow shutoff valve at mould, the action of the telescopic air tube of described hydraulic control, hydraulic control runner stop valve and hydraulic control overflow shutoff valve provides control signal by cyclelog, is carried out by hydraulic system or the external HYDRAULIC CONTROL SYSTEM of injection machine.

The present invention compared with prior art, adopt gas pressure booster and the hydraulic pressure generating means of gas assisted molding to produce high pressure nitrogen required for the present invention and high-pressure high-flow solid stream of water respectively, by default water shaping technology, at first will inject die cavity to a small amount of high pressure nitrogen that time and pressure are controlled automatically by the gas injection pressure close loop control circuit and carry out the preformed of plastic hollow, then again will be to the time by the water injection pressure close loop control circuit, pressure and flow carry out the segmentation water under high pressure injection die cavity of control automatically, promote a small amount of high pressure nitrogen in forward position, finish the hollow molding of plastic jointly, pressurize and cooling and shaping process.Then the water in the die cavity is discharged, the pressure in the die cavity is reduced to setting value, subsequently, utilizes the compressed air drainage cell or vacuumize drainage cell residual injection water is drained or drains.Open mould at last plastic is ejected, finish the water shaping of plastic smoothly.In this process, to the changeover portion of melt, solidified the very thin plastic foil of one deck from the forward position of nitrogen, it resembles a full-bodied piston, promotes the plastic cement melt and advances and be full of die cavity very soon.Because nitrogen carries out hollow molding in front, water cools off in the back, both having solved existing water shaping technology only is medium with water, water directly contacts with the plastic cement melt in forward position and the too fast cooling of melt that causes, the deficiency that curing is difficult to be full of die cavity, the fine pyroconductivity of having utilized water and specific heat capacity are than the height of gas again, be very beneficial for the characteristic of plasthetics cooling, also utilized the compressibility of gas to solve the problem of injecting the impact of instant water decompression in the existing water shaping process better.The present invention shows the advantage of nitrogen G﹠W, existing gas assisted molding and water shaping fully, to realize steady water filling and pressurize, improves plastic part quality, reduces the purpose of product development and production cost.

Description of drawings

Fig. 1 is that plastic cement melt of the present invention is injected into schematic diagram in the mold cavity.

Fig. 2 is that nitrogen injection of the present invention carries out hollow preformed schematic diagram.

Fig. 3 is that injection water under high pressure of the present invention carries out the hollow molding schematic diagram.

Fig. 4 is that injection water of the present invention is full of die cavity and spill cavity and pressurize schematic diagram fully with the plastic cement melt.

Fig. 5 is that water under high pressure of the present invention is discharged schematic diagram in plastic.

Fig. 6 is that the telescopic air tube of hydraulic control that utilizes of the present invention dries up schematic diagram with residual injection water.

Fig. 7 be of the present invention when opening mould plastic eject schematic diagram.

Fig. 8 enters next injection molding cycle schematic diagram behind the closed die of the present invention.

Fig. 9 is the structural representation of embodiments of the invention 1.

Figure 10 is the structural representation of hydraulic pressure generating means of the present invention.

Figure 11 is the structural representation of embodiments of the invention 2.

Figure 12 is the structural representation of embodiments of the invention 3.

The specific embodiment

Below in conjunction with drawings and Examples the present invention is described in further detail.In Fig. 1-12, each sequence number is represented: 1. high-pressure water, 2. elevated pressure nitrogen source of the gas, 3. compressed air source, 4. water under high pressure stop valve, 5. high pressure nitrogen stop valve, 6. compressed air stop valve, 7. water under high pressure filter, 8. high pressure nitrogen filter, 9. compressed-air filter, 10. water filling accumulator, 11. the water filling high-pressure solenoid valve, 12. Flow-rate adjustment magnetic valves, 13. gas injection high-pressure solenoid valve, 14. gas injection magnetic valve, 15. the high-voltage electric air valve, 16. first check valves, 17. high-voltage electric water valves, 18. pressure sensor, 19. cyclelog, 20. step-down magnetic valves, 21. filters, 22. water tank, 23. controller of plastic injection molding, 23-A. injection mechanism of injection machine, the telescopic air tube of 24. hydraulic controls, 25. liquid drugs injection, 26. mould, 26-A. spill cavity, 26-B. die cavity, 26-C. plastic cement melt, 26-D. nitrogen,, 26-E. water, the 26-F. plastic, 26-G. compressed air, 27. hydraulic control runner stop valve, 28. hydraulic control overflow shutoff valve, 29. Pressure gauges, 30. industrial high-pressure hydraulic pump, 31. the pump front filter, 32. safety valves, 33. pump after-filters, 34. motor, 35. second check valve, 36. pressure are kept and unidirectional combination valve, 37. pressure switches, 38. water under high pressure accumulator, 39. stop valve, 40. hydraulic controllers, 41. water pressure gauges, 42. vacuum source, 43. vacuum tank, 44. vacuum transfer valves, 45. vacuum pressure switch, 46. vacuum electric ball valve, 47. vacuum filter, 48. hydraulic pressure generating means, 49. gas injection pressure close loop control circuits, 50. water injection pressure close loop control circuit, 51. the step-down close loop control circuit, 52. compressed air emptying unit, 53. vacuumize the emptying unit

Water shaping technology of the present invention may further comprise the steps at least:

The first step, as shown in Figure 1,23-A is injected into plastic cement melt 26-C in the die cavity 26-B by controller of plastic injection molding control injection mechanism of injection machine, makes to be full of or to be full of substantially plastic cement melt 26-C in the die cavity.In this step, the hydraulic control runner stop valve 27 that is installed in the mould 26 is opened, and guarantees that injection mechanism of injection machine 23-A can directly be injected into plastic cement melt 26-C in the die cavity 26-B swimmingly.The hydraulic control overflow shutoff valve 28 that is installed in the mould 26 is closed, and is in order to control this process better, to guarantee the pressure in the die cavity 26-B.

Second step, as shown in Figure 2, after injection mechanism of injection machine 23-A injection finishes, input to cyclelog 19 sends the injection end signal, just water is assisted the technology sign on, the unlatching of each sequential process in the control water shaping technology, output by cyclelog 19 sends control signal, carry out hydraulic control runner stop valve 27 by the HYDRAULIC CONTROL SYSTEM of injection machine and close with hydraulic control overflow shutoff valve 28 and open, can also be carried out the action of hydraulic control runner stop valve 27 and hydraulic control overflow shutoff valve 28 by external HYDRAULIC CONTROL SYSTEM.The small amount of nitrogen 26-D that will be controlled automatically time and pressure by gas injection pressure close loop control circuit 49 is in liquid drugs injection 25 injects die cavity 26-B plastic cement melt 26-C, force that the hydraulic control overflow shutoff valve 28 of some plastic cement melt 26-C through opening enters spill cavity 26-A in the die cavity from die cavity, carry out the hollow preformed process of plastic.Close hydraulic control runner stop valve 27 and be in order to prevent that the plastic cement melt 26-C in the die cavity 26-B is back in the machine barrel of injection machine, open hydraulic control overflow shutoff valve 28 then to be to push some unnecessary plastic cement melt 26-C to spill cavity 26-A when guaranteeing that gas injects.In this process, can be controlled to the wall thickness of shape spare by the time interval that control plastic cement melt 26-C injection finishes and gas injects.

The 3rd step, as shown in Figure 3, to carry out the segmentation back of water under high pressure 26-E nitrogen injection 26-D in liquid drugs injection 25 is injected into die cavity 26-B of control automatically to time, pressure and flow by water injection pressure close loop control circuit 50 again, the mobile mold filling of the plastic cement melt 26-C that promotion contacts with nitrogen injection 26-D forward position, further force the hydraulic control overflow shutoff valve 28 of some melts through opening from die cavity, to enter spill cavity 26-A, finish the hollow molding process of plastic.In this process, to the changeover portion of melt, solidified the very thin plastic foil of one deck from the forward position of nitrogen 26-D, it resembles a full-bodied piston, promotes plastic cement melt 26-C and advances and be full of die cavity very soon.Because nitrogen 26-D carries out hollow molding in front, water 26-E carries out cooling off after the moulding in the back, both having solved existing water shaping technology only is medium with water, water directly contacts with the plastic cement melt in forward position and the too fast cooling of melt that causes, the deficiency that curing is difficult to be full of die cavity, the fine pyroconductivity of having utilized water and specific heat capacity are than the height of gas again, be very beneficial for the characteristic of plasthetics cooling, also utilized the compressibility of gas to solve the problem of injecting the impact of instant water decompression in the existing water shaping process better.The present invention shows the advantage of nitrogen G﹠W, existing gas assisted molding and water shaping fully, to realize steady water filling and pressurize, improves plastic part quality, reduces the purpose of product development and production cost.

The 4th step, as shown in Figure 4, the water under high pressure 26-E that is continued to control automatically time, pressure and flow by water injection pressure close loop control circuit 50 in liquid drugs injection 25 is injected into die cavity 26-B, guarantee plastic cement melt 26-C in cooling curing, volume contraction process the pressure stability in the die cavity in setting value.In this process, inject the effect that water 26-E in fact only plays pressurize, and hydraulic pressure remains to after plastic cement melt 26-C cooling curing in the mould cavity 26-B is shaped into plastic 26-F.But compare with traditional plastic cement melt pressurize, it is more effective that water plays the pressurize effect.

The 5th step, as shown in Figure 5, after the plastic cement melt 26-C cooling curing typing in the die cavity 26-B, to be discharged by the injection water 26-E in the step-down close loop control circuit 51 control die cavitys, the pressure in the die cavity is reduced to setting value.In this process, steadily discharged by the injection water 26-E in the step-down close loop control circuit control die cavity, the pressure in the die cavity is reduced to setting value, generally is set at normal pressure.

The 6th step, as shown in Figure 6, send control signal by cyclelog 19, stretched among the spill cavity 26-A in the plastic 26-F of solidifying and setting by the telescopic air tube 24 of the HYDRAULIC CONTROL SYSTEM hydraulic control of injection machine, compressed air drainage cell 52 imports compressed air 26-G in the plastic 26-F through the telescopic air tube of hydraulic control, and injection water 26-E residual in the plastic 26-F is drained.Can also be by the action of the telescopic air tube 24 of external HYDRAULIC CONTROL SYSTEM hydraulic control.This process also can be utilized and vacuumize drainage cell 53 injection water 26-E residual in the plastic 26-F is drained.The telescopic air tube 24 of hydraulic control also can be installed in the position that can stretch among the die cavity 26-B, directly the plastic 26-F internal drainage from die cavity 26-B.For water shaping plastic simple in structure, if only rely on nitrogen injection 26-D in the plastic 26-F and the residual injection water 26-E gravity effect can emptying, this step just can be used as the adapted step.

In the 7th step, as shown in Figure 7, after the interior residual injection water 26-E emptying of plastic 26-F, by the die opening and closing mechanism opening mould 26 of controller of plastic injection molding 23 control injection machines, 26-F ejects with plastic.

The 8th step; as shown in Figure 8; at last; die opening and closing mechanism closed die 26 by controller of plastic injection molding 23 control injection machines; provide control signal by cyclelog 19; hydraulic system or the telescopic air tube 24 of external HYDRAULIC CONTROL SYSTEM hydraulic control, hydraulic control runner stop valve 27 and hydraulic control overflow shutoff valve 28 by injection machine reset, and enter next injection molding cycle.

Described water shaping technology can arrange the telescopic air tube 24 of more than one hydraulic control, liquid drugs injection 25, spill cavity 26-A, hydraulic control runner stop valve 27 and hydraulic control overflow shutoff valve 28 on mould 26.

As shown in Figure 9, constant voltage water aided injection forming device embodiment 1 of the present invention, comprise gas injection pressure close loop control circuit 49, water injection pressure close loop control circuit 50, step-down close loop control circuit 51, compressed air drainage cell 52, controller of plastic injection molding 23 and be installed in the telescopic air tube 24 of hydraulic control and liquid drugs injection 25 in the mould 26, described controller of plastic injection molding 23 linker controllers 19, one end of the telescopic air tube 24 of described hydraulic control stretches in the spill cavity 26-A, and the other end connects compressed air drainage cell 52; One end of described liquid drugs injection 25 stretches in the die cavity 26-B, and an end also connects gas injection pressure close loop control circuit 49, water injection pressure close loop control circuit 50 and step-down close loop control circuit 51 respectively;

Described gas injection pressure close loop control circuit 49 is by high-pressure air source 2, high pressure nitrogen stop valve 5, high pressure nitrogen filter 8, gas injection high-pressure solenoid valve 13, high-voltage electric air valve 15, pressure sensor 18 and cyclelog 19 are formed, described elevated pressure nitrogen source of the gas 2 is through high pressure nitrogen stop valve 5, high pressure nitrogen filter 8 connects the entrance of gas injection high-pressure solenoid valve 13, the outlet of gas injection high-pressure solenoid valve 13 is joined through high-voltage electric air valve 15 and liquid drugs injection 25, liquid drugs injection 25 communicates with plastic cement melt 26-C inside among the die cavity 26-B, connect pressure sensor 18 between high-voltage electric air valve 15 and the liquid drugs injection 25, described pressure sensor 18 connects the input of cyclelog 19, and the output of described cyclelog 19 connects gas injection high-pressure solenoid valve 13 and high-voltage electric air valve 15 respectively;

As shown in Figure 1, the technical process of constant voltage water aided injection forming device of the present invention work: at first, 23 control injection mechanism of injection machine 23-A are injected into plastic cement melt 26-C in the die cavity 26-B by controller of plastic injection molding, make to be full of or to be full of substantially the plastic cement melt in the die cavity.Receive the injection end signal that is sent by controller of plastic injection molding 23 when cyclelog 19, just water is assisted the technology sign on, by default water shaping technical process, control the unlatching of each sequential process, output by cyclelog 19 sends control signal, the hydraulic control runner stop valve 27 that is installed in the mould 26 is closed, and the hydraulic control overflow shutoff valve 28 that is installed in the mould 26 is opened.The output of cyclelog 19 is directly controlled high-voltage electric air valve 15 and is opened, pressure sensor 18 is with the outlet pressure of real-time detected high-voltage electric air valve 15, feed back to the input of cyclelog 19, if detected value is less than the technique initialization value in real time, export the outlet pressure that high-voltage electric air valve 15 is adjusted in 15 actions of corresponding signal controlling gas injection high-pressure solenoid valve 13 and high-voltage electric air valve through the output of cyclelog 19, the pressure of nitrogen injection 26-D just, technical process as shown in Figure 2, liquid drugs injection 25 acts on the plastic cement melt 26-C inside in the small amount of nitrogen 26-D injection die cavity 26-B of pressure controlled system plastic cement melt 26-C inside and carries out the preformed of plastic hollow.Use high-voltage electric air valve 15 as the switch valve that nitrogen injects in the above-mentioned gas injection pressure close loop control circuit, can guarantee to inject in the injecting process of back water and can instead not flow into the gas injection pressure close loop control circuit, influence the water shaping of next injection cycle;

Described water injection pressure close loop control circuit 50 is by high-pressure water 1, water under high pressure stop valve 4, water under high pressure filter 7, water filling accumulator 10, water filling high-pressure solenoid valve 11, Flow-rate adjustment magnetic valve 12, high-voltage electric water valve 17, Pressure gauge 29, pressure sensor 18 and cyclelog 19 are formed, described high-pressure water 1 is through water under high pressure stop valve 4, water under high pressure filter 7 connects water filling accumulator 10, the entrance of water filling high-pressure solenoid valve 11 and Flow-rate adjustment magnetic valve 12, water filling high-pressure solenoid valve 11 is connected with the entrance of high-voltage electric water valve 17 with the outlet of Flow-rate adjustment magnetic valve 12, the outlet water receiving pin 25 of high-voltage electric water valve 17, connect pressure sensor 18 and Pressure gauge 29 between high-voltage electric water valve 17 and the liquid drugs injection 25, the output of described cyclelog 19 connects water filling high-pressure solenoid valve 11 respectively, Flow-rate adjustment magnetic valve 12 and high-voltage electric water valve 17;

After the described gas injection, the output control high-voltage electric water valve 17 of cyclelog 19 is opened, pressure sensor 18 is with the outlet pressure of real-time detected high-voltage electric water valve 17, feed back to the input of cyclelog 19, if detected value is less than the technique initialization value in real time, export corresponding signal through the output of cyclelog 19 and control the outlet pressure that high-voltage electric water valve 17 is adjusted in 17 actions of water filling high-pressure solenoid valve 11 and high-voltage electric water valve respectively, just inject the pressure of water 26-E, if inject the pressure climbing speed of water 26-E less than the technique initialization value, the output of cyclelog 19 is exported the rate of discharge that high-voltage electric water valve 17 is adjusted in corresponding signal controlling Flow-rate adjustment magnetic valve 12 actions, just inject the flow of water 26-E, realize that in conjunction with water filling accumulator 10 but moment provides big flow to inject water and makes pressure moment of injecting water reach the technological requirement of setting value, technical process such as Fig. 3, shown in 4, liquid drugs injection 25 is with the plastic cement melt 26-C inside in the continuous water 26-E injection die cavity 26-B of pressure and flow rates controlled system, act on plastic cement melt 26-C inside, promote a small amount of nitrogen injection 26-D in forward position, finish the hollow molding of plastic jointly, pressurize and cooling and shaping process.The switch valve that uses high-voltage electric water valve 17 to inject as water in the above-mentioned water injection pressure close loop control circuit, can guarantee zero leakage in the water injection process, solved the sealing problem that injects water, can guarantee that also nitrogen can instead not flow into the water injection pressure close loop control circuit in the gas injection process of front, have influence on water shaping.Adopt water filling accumulator 10 to realize injecting water energy storage and pressurize, solved that stable water pressure and moment provide big flow to inject the problem of water in the water injection process;

Described step-down close loop control circuit 51 is made up of step-down magnetic valve 20, filter 21, water tank 22, pressure sensor 18 and cyclelog 19, the described liquid drugs injection 25 that is installed in the mould 26 is connected with the entrance of step-down magnetic valve 20 through filter 21, the outlet water receiving case 22 of step-down magnetic valve 20, described water tank 22 connects hydraulic pressure generating means 48, connect pressure sensor 18 between filter 21 and the liquid drugs injection 25, the output termination step-down magnetic valve 20 of described cyclelog 19;

After the plastic cement melt 26-C cooling curing typing in the described die cavity 26-B, pressure sensor 18 is with real-time detected step-down magnetic valve 20 inlet pressures, feed back to the input of cyclelog 19, export the inlet pressure that step-down magnetic valve 20 is adjusted in 20 drainings of corresponding signal controlling step-down magnetic valve through the output of cyclelog 19, just inject the pressure of water 26-E in the die cavity 26-B, technical process as shown in Figure 5, the water 26-E of discharge directly enters water tank 22.If in second and third step process of processing step, pressure sensor 18 real-time detected values are during greater than the technique initialization value, equipment can utilize this loop to adjust the interior pressure of plastic cement melt 26-C automatically, the direct emptying of nitrogen 26-D of discharge, and the water 26-E of discharge directly enters water tank 22;

Described compressed air drainage cell 52 is by compressed air source 3, compressed air stop valve 6, compressed-air filter 9, gas injection magnetic valve 14, first check valve 16 and cyclelog 19 are formed, described compressed air source 3 compressed air cutoff valves 6, compressed-air filter 9 connects the entrance of gas injection magnetic valve 14, the outlet of gas injection magnetic valve 14 is connected with the telescopic air tube 24 of the hydraulic control in being installed in mould 26 through first check valve 16, can stretching among the spill cavity 26-A during work, solidifying and setting is the inside of plastic 26-F, communicate with plastic 26-F inside, described cyclelog 19 connects control gas injection magnetic valve 14;

When treating that drainage and step-down arrives setting value, output by cyclelog 19 sends control signal, control hydraulic control telescopic air tube 24 stretches among the spill cavity 26-A in the plastic 26-F of solidifying and setting, technical process as shown in Figure 6, cyclelog 19 is opened through output control gas injection magnetic valve 14, the telescopic air tube 24 of the hydraulic control of compressed air 26-G in being installed in mould 26 enters the inside of plastic 26-F, and residual injection water 26-E is flow back to water tank 22 through step-down close loop control circuit 51 from the inside of plastic 26-F.Use first check valve 16 in the above-mentioned compressed air drainage cell, can guarantee in gas injection in front, the injecting process, injection gas, injection water can instead not flow into the compressed air drainage cell, have influence on water shaping;

Described high-pressure water 1 is provided by hydraulic pressure generating means 48, as shown in figure 10, comprise industrial high-pressure hydraulic pump 30, pump front filter 31, safety valve 32, pump after-filter 33, motor 34, second check valve 35, pressure is kept and unidirectional combination valve 36, pressure switch 37, water under high pressure accumulator 38, stop valve 39, hydraulic controller 40, water pressure gauge 41, water tank 22, described industrial high-pressure hydraulic pump 30 entrances that driven by motor 34 are through pump front filter 31 water receiving casees 22,30 outlets of industry high-pressure hydraulic pump are through pump after-filter 33, second check valve 35, pressure is kept with unidirectional combination valve 36 and is connect pressure switch 37, water under high pressure accumulator 38, the entrance of water pressure gauge 41 and stop valve 39, the outlet of stop valve 39 connects the entrance of the water under high pressure stop valve 4 in the water injection pressure close loop control circuit 50, provide big flow continuous high-pressure water 1 to constant voltage water-aid injection molding equipment, described industrial high-pressure hydraulic pump 30 outlets also take back water tank 22 through safety valve 32, the input of pressure switch 37 water receiving pressure-controlled devices 40, the output termination motor 34 of hydraulic controller 40, pressure switch 37 is used for detecting in real time the pressure of water under high pressure accumulator 38, when the pressure of water under high pressure accumulator 38 reaches setting value, send the input that feeds back signal to hydraulic controller 40, output control motor 34 actions by hydraulic controller 40 utilize safety valve 32, pressure is kept with unidirectional combination valve 36 and water under high pressure accumulator 38 and is realized variable hydraulic pressure control and the system of assurance security of operation.

Described elevated pressure nitrogen source of the gas 2 is provided by the gas pressure booster of gas assisted molding, and compressed air source 3 is provided by the industrial air compressor.

As shown in figure 11, constant voltage water aided injection forming device embodiment 2 of the present invention, similar to the embodiment of the invention 1 shown in Figure 10, both differences are, substitute the injection water purging method of embodiment 1 usefulness compressed air drainage cell 52 shown in Figure 10 among the embodiment 2 shown in Figure 11 with the injection water purging method that vacuumizes drainage cell 53.

This constant voltage water aided injection forming device comprises gas injection pressure close loop control circuit 49, water injection pressure close loop control circuit 50, step-down close loop control circuit 51, vacuumize drainage cell 53, controller of plastic injection molding 23 and be installed in liquid drugs injection 25 in the mould 26, described controller of plastic injection molding 23 linker controllers 19, one end of described liquid drugs injection 25 stretches in the die cavity 26-B, and an end also connects gas injection pressure close loop control circuit 49, water injection pressure close loop control circuit 50, step-down close loop control circuit 51 respectively and vacuumizes drainage cell 53;

Described gas injection pressure close loop control circuit 49 is by high-pressure air source 2, high pressure nitrogen stop valve 5, high pressure nitrogen filter 8, gas injection high-pressure solenoid valve 13, high-voltage electric air valve 15, pressure sensor 18 and cyclelog 19 are formed, described elevated pressure nitrogen source of the gas 2 is through high pressure nitrogen stop valve 5, high pressure nitrogen filter 8 connects the entrance of gas injection high-pressure solenoid valve 13, the outlet of gas injection high-pressure solenoid valve 13 is joined through high-voltage electric air valve 15 and liquid drugs injection 25, liquid drugs injection 25 communicates with plastic cement melt 26-C inside among the die cavity 26-B, connect pressure sensor 18 between high-voltage electric air valve 15 and the liquid drugs injection 25, described pressure sensor 18 connects the input of cyclelog 19, and the output of described cyclelog 19 connects gas injection high-pressure solenoid valve 13 and high-voltage electric air valve 15 respectively;

Described water injection pressure close loop control circuit 50 is by high-pressure water 1, water under high pressure stop valve 4, water under high pressure filter 7, water filling accumulator 10, water filling high-pressure solenoid valve 11, Flow-rate adjustment magnetic valve 12, high-voltage electric water valve 17, Pressure gauge 29, pressure sensor 18 and cyclelog 19 are formed, described high-pressure water 1 is through water under high pressure stop valve 4, water under high pressure filter 7 connects water filling accumulator 10, the entrance of water filling high-pressure solenoid valve 11 and Flow-rate adjustment magnetic valve 12, water filling high-pressure solenoid valve 11 is connected with the entrance of high-voltage electric water valve 17 with the outlet of Flow-rate adjustment magnetic valve 12, the outlet water receiving pin 25 of high-voltage electric water valve 17, connect pressure sensor 18 and Pressure gauge 29 between high-voltage electric water valve 17 and the liquid drugs injection 25, the output of described cyclelog 19 connects water filling high-pressure solenoid valve 11 respectively, Flow-rate adjustment magnetic valve 12 and high-voltage electric water valve 17;

Described step-down close loop control circuit 51 is made up of step-down magnetic valve 20, filter 21, water tank 22, pressure sensor 18 and cyclelog 19, the described liquid drugs injection 25 that is installed in the mould 26 is connected with the entrance of step-down magnetic valve 20 through filter 21, the outlet water receiving case 22 of step-down magnetic valve 20, described water tank 22 connects hydraulic pressure generating means 48, connect pressure sensor 18 between filter 21 and the liquid drugs injection 25, pressure sensor 18, step-down magnetic valve 20 are connected with cyclelog 19;

The described drainage cell 53 that vacuumizes is by vacuum source 42, vacuum tank 43, vacuum transfer valve 44, vacuum pressure switch 45, vacuum electric ball valve 46, vacuum filter 47 and cyclelog 19 are formed, described vacuum source 42 and vacuum tank 43, the outlet of vacuum transfer valve 44 is connected, the entrance of vacuum transfer valve 44 is through vacuum electric ball valve 46, vacuum filter 47 water receiving pins 25, be connected to vacuum pressure switch 45 between vacuum transfer valve 44 and the vacuum electric ball valve 46, vacuum pressure switch 45 connects the input of cyclelog 19, and the output of cyclelog 19 connects vacuum transfer valve 44 and vacuum electric ball valve 46 respectively;

When treating that drainage and step-down arrives setting value, output control vacuum electric ball valve 46 by cyclelog 19 is opened, with vacuum pressure switch 45 and plastic 26-F internal switching, vacuum pressure switch 45 is used for detecting in real time the vacuum pressure of plastic 26-F inside, and send the input that feeds back signal to cyclelog 19, control vacuum transfer valve 44 and 46 actions of vacuum electric ball valve respectively through the output of cyclelog 19, residual injection water 26-E is drained from plastic 26-F inside through liquid drugs injection 25, vacuum filter 47.Above-mentioned vacuumizing uses vacuum electric ball valve 46 as the switch valve that vacuumizes in the drainage cell, can guarantee in gas injection in front, the injecting process, and injection gas, injection water can instead not flow into and vacuumize drainage cell, have influence on water shaping.

The high-pressure water 1 of present embodiment and elevated pressure nitrogen source of the gas 2 adopts the identical device with embodiment 1 shown in Figure 10 to provide, and vacuum source 42 is provided by vavuum pump.

As shown in figure 12, constant voltage water aided injection forming device embodiment 3 of the present invention, similar to the embodiment of the invention 2 shown in Figure 11, simplified by embodiment 2, both differences are, at water shaping plastic simple in structure, only rely on nitrogen injection 26-D in the plastic 26-F and the residual injection water 26-E gravity effect just can emptying, just substitute embodiment shown in Figure 11 2 with the injection water purging method that relies on nitrogen injection 26-D in the plastic 26-F and residual injection water 26-E gravity effect among the embodiment shown in Figure 12 3 and adopt the injection water purging method that vacuumizes drainage cell 53, that is: removed among the embodiment 3 shown in Figure 12 and vacuumize drainage cell 53 among the embodiment shown in Figure 11 2;

This constant voltage water aided injection forming device comprises gas injection pressure close loop control circuit 49, water injection pressure close loop control circuit 50, step-down close loop control circuit 51, controller of plastic injection molding 23 and is installed in liquid drugs injection 25 in the mould 26, described controller of plastic injection molding 23 linker controllers 19, one end of described liquid drugs injection 25 stretches in the die cavity 26-B, and an end also connects gas injection pressure close loop control circuit 49, water injection pressure close loop control circuit 50 and step-down close loop control circuit 51 respectively;

Described gas injection pressure close loop control circuit 49 is by high-pressure air source 2, high pressure nitrogen stop valve 5, high pressure nitrogen filter 8, gas injection high-pressure solenoid valve 13, high-voltage electric air valve 15, pressure sensor 18 and cyclelog 19 are formed, described elevated pressure nitrogen source of the gas 2 is through high pressure nitrogen stop valve 5, high pressure nitrogen filter 8 connects the entrance of gas injection high-pressure solenoid valve 13, the outlet of gas injection high-pressure solenoid valve 13 is joined through high-voltage electric air valve 15 and liquid drugs injection 25, liquid drugs injection 25 communicates with plastic cement melt 26-C inside among the die cavity 26-B, connect pressure sensor 18 between between high-voltage electric air valve 15 and the liquid drugs injection 25, described pressure sensor 18 connects the input of cyclelog 19, and the output of described cyclelog 19 connects gas injection high-pressure solenoid valve 13 and high-voltage electric air valve 15 respectively;

Described water injection pressure close loop control circuit 50 is by high-pressure water 1, water under high pressure stop valve 4, water under high pressure filter 7, water filling accumulator 10, water filling high-pressure solenoid valve 11, Flow-rate adjustment magnetic valve 12, high-voltage electric water valve 17, Pressure gauge 29, pressure sensor 18 and cyclelog 19 are formed, described high-pressure water 1 is through water under high pressure stop valve 4, water under high pressure filter 7 connects water filling accumulator 10, the entrance of water filling high-pressure solenoid valve 11 and Flow-rate adjustment magnetic valve 12, water filling high-pressure solenoid valve 11 is connected with the entrance of high-voltage electric water valve 17 with the outlet of Flow-rate adjustment magnetic valve 12, the outlet water receiving pin 25 of high-voltage electric water valve 17, connect pressure sensor 18 and Pressure gauge 29 between high-voltage electric water valve 17 and the liquid drugs injection 25, the output of described cyclelog 19 connects water filling high-pressure solenoid valve 11 respectively, Flow-rate adjustment magnetic valve 12 and high-voltage electric water valve 17;

Described step-down close loop control circuit 51 is made up of step-down magnetic valve 20, filter 21, water tank 22, pressure sensor 18 and cyclelog 19, the described liquid drugs injection 25 that is installed in the mould 26 is connected with the entrance of step-down magnetic valve 20 through filter 21, the outlet water receiving case 22 of step-down magnetic valve 20, described water tank 22 connects hydraulic pressure generating means 48, connect pressure sensor 18 between filter 21 and the liquid drugs injection 25, pressure sensor 18, step-down magnetic valve 20 are connected with cyclelog 19;

After the plastic cement melt 26-C cooling curing typing in the described die cavity 26-B, by step-down close loop control circuit 51 control drainage and step-down processes, treat that drainage and step-down arrives setting value, normally during the normal pressure value, be in normally open by cyclelog 19 control step-down magnetic valves 20, rely on nitrogen injection 26-D and residual injection water 26-E gravity double action in the plastic 26-F, with the injection water 26-E emptying inlet water tank 22 of final residual in the plastic.

In sum, the required pressure of the constant voltage water-aid injection molding equipment that the present invention utilizes the gas pressure booster of gas assisted molding and hydraulic pressure generating means to provide respectively to the present invention relates to up to 35MPa nitrogen and pressure up to the continuous high-pressure water of 30Mpa, at first, by injection mechanism of injection machine 23-A plastic cement melt 26-C is injected in the die cavity 26-B, the injection end signal that sends to cyclelog 19, just water is assisted the technology sign on, cyclelog 19 is by default water shaping technical process, according to pressure sensor 18 force value that detects in real time and the water shaping technique initialization value comparative result of presetting, form the gas injection pressure control modules by gas injection pressure close loop control circuit 49 and step-down close loop control circuit 51, the preformed of plastic hollow is carried out in the plastic cement melt 26-C inside that will inject in the die cavity 26-B the small amount of nitrogen 26-D that time and pressure are controlled automatically.After the gas injection, form the water injection pressure control module by water injection pressure close loop control circuit 50 and step-down close loop control circuit 51 again, to carry out the segmentation continuous water 26-E injection plastic cement melt 26-C inside of control automatically to time, pressure and flow, promote a small amount of nitrogen injection 26-D in forward position, finish hollow molding, pressurize, cooling and shaping and the drainage and step-down process of plastic jointly.Treat that drainage and step-down arrives setting value, normal pressure normally, residual injection water 26-E utilizes the compressed air drainage cell, provides compressed air 26-G by the industrial air compressor, and residual injection water 26-E is drained; Can also utilize to vacuumize drainage cell, provide vacuum source 42 by vavuum pump, residual injection water 26-E is drained.Open mould 26 at last and take out plastic 26-F, finish the water shaping of plastic 26-F smoothly.

Wherein, water filling high-pressure solenoid valve 11, Flow-rate adjustment magnetic valve 12, gas injection high-pressure solenoid valve 13, step-down magnetic valve 20 are selected high accuracy anti-leak high-pressure solenoid valve for use; High-voltage electric air valve 15, high-voltage electric water valve 17 and vacuum electric ball valve 46 are selected zero leakage high-voltage electric ball valve for use; Pressure sensor 18 is selected for use pneumatic, hydraulic dual-purpose high-pressure type pressure sensor; Water under high pressure filter 7, high pressure nitrogen filter 8, compressed-air filter 9, filter 21, pump front filter 31, pump after-filter 33 and vacuum filter 47 are selected the sintering metal type filter for use; Water under high pressure stop valve 4, high pressure nitrogen stop valve 5, compressed air stop valve 6 and stop valve 39 are selected the big Lip river of generation gram manual ball valve for use; First check valve 16, second check valve 35 and pressure are kept with unidirectional combination valve 36 and are selected high pressure valve for use; Industry high-pressure hydraulic pump 30 is selected quantitative hydraulic pump for use; Elevated pressure nitrogen source of the gas 2 is provided by the gas pressure booster of gas assisted molding, can adopt patent of invention number to be ZL200510121110.4, and denomination of invention is the gas pressure booster in the pressure-sustaining gas assistant injection molding system; Compressed air source 3 is provided by the industrial air compressor, the LU series screw compressor that can adopt Sweden AtlasCopco wholly owned subsidiary to produce; Vacuum source 42 is provided by vavuum pump, the LG dry type rotors for dry double-screw vacuum pump that can adopt Shanghai Vaccum Pump Factory to produce.

The present invention has following characteristics:

One, the present invention utilizes the gas assisted molding maturation process, characteristics in conjunction with water shaping form unique control water under high pressure injection water shaping technology, both having solved existing water shaping technology only is medium with water, water directly contacts with the plastic cement melt in forward position and the too fast cooling of melt that causes, solidify the deficiency that is difficult to be full of die cavity, the fine pyroconductivity of having utilized water and specific heat capacity are than the height of gas again, be very beneficial for the characteristic of plasthetics cooling, also utilized the compressibility of gas to solve the problem of injecting the impact of instant water decompression in the existing water shaping process better.The present invention shows the advantage of nitrogen G﹠W, existing gas assisted molding and water shaping fully, to realize steady water filling and pressurize, improves plastic part quality, reduces the purpose of product development and production cost.

Two, the present invention is by gas injection pressure control module, water injection pressure control module, compressed air drainage cell or vacuumize drainage cell and constant pressure water-aid injection molding system that injection machine is formed, can move independently of one another between each unit, can control mutually again, form safety interlocking, with realize steadily, continuous gas injection, water filling and accurate pressure regulation of moment, finish hollow molding, pressurize and the cooling and shaping of plastic smoothly, improve the water shaping plastic part quality, guarantee security of system.

Three, gas injection pressure control module of the present invention is made up of gas injection pressure close loop control circuit and step-down close loop control circuit, to realize two closed-loop controls of gas injection pressure, has faster system response, is swift in response and pressure precision of real time control high-technology advantage.Use the high-voltage electric air valve as the switch valve that nitrogen injects in the gas injection pressure close loop control circuit, can guarantee to inject in the injecting process water and can instead not flow into the gas injection pressure close loop control circuit, influence the water shaping of next injection cycle.

Four, water injection pressure control module of the present invention is made up of water injection pressure close loop control circuit and step-down close loop control circuit, to realize two closed-loop controls of water injection pressure, have response fast, be swift in response, flow controlled and pressure precision of real time control high-technology advantage in real time, solved the pressure, the flow that inject the plastic cement internal water and can reach this water shaping technological core problem of specification requirement moment.The switch valve that uses the high-voltage electric water valve to inject as water in the water injection pressure close loop control circuit, can guarantee zero leakage in the water injection process, solved the sealing problem that injects water, avoided in case generation is injected the water leakage or is ejected on the mould, can't realize water shaping, influence the Forming Quality of goods.Also used the water filling accumulator to realize injecting water energy storage and pressurize in the water injection pressure close loop control circuit, solved that stable water pressure and moment provide big flow to inject the problem of water in the water injection process.

Five, the present invention can utilize the compressed air drainage cell, provides compressed air by the industrial air compressor, and residual injection water is dried up; Can also utilize to vacuumize drainage cell, provide vacuum source by vavuum pump, residual injection water is drained.Can guarantee in the mould anhydrous residually, solve the discharge problem of injecting water.Using first check valve in the compressed air drainage cell or vacuumizing uses the vacuum electric ball valve as the switch valve that vacuumizes in the drainage cell, can guarantee that nitrogen injection in gas injection, the injecting process, injection water can instead not flow into the compressed air drainage cell or vacuumize drainage cell, influence the water shaping of next injection cycle.

Six, the present invention is provided with the hydraulic pressure generating means of independent operating, adopt industrial high-pressure hydraulic pump directly water to be pressurizeed, utilize pressure to keep with unidirectional combination valve, pressure switch, safety valve and water under high pressure accumulator and realize variable hydraulic pressure control, the pressure that provides the water shaping technology required, the high-pressure water of stability of flow are provided.

Seven, the present invention has effectively overcome the existing outlet pressure that utilizes pressure sensor feedback solenoid-operated proportional pressure-reducing valve, regulate the outlet pressure of this valve or the high pressure chest output pressure of adopts pressure sensor feedback pressurized cylinder by the proportion electro-magnet of controlling this valve, regulate by the proportion electro-magnet of controlling this back pressure regulating valve in the outlet pressure technology of this valve, system response time is long, reaction is slow, inject the constant and pressure of water volume, flow is uncontrollable and shortcoming such as easy leakage.

Eight, the present invention also is provided with gas pressure booster, industrial air compressor and the vavuum pump of independent operating, provides the water shaping technology required elevated pressure nitrogen source of the gas, compressed air source and vacuum source respectively.The elevated pressure nitrogen source of the gas adopts the elevated pressure nitrogen source of the gas of existing gas assisted molding, and compressed air source and vacuum source adopt the existing compressed air source of factory and vacuum source, advantages such as the maturation that possesses skills, capacity utilization height, production efficiency height, reduction equipment cost.

Nine, use equipment of the present invention to carry out the moulding of water shaping, have the no shrink mark in surface, advantages such as surfaces externally and internally is more smooth, stress deformation is little, thinner more even, the saving plastic raw materials of the wall thickness of goods, injection cycle is faster and economy is better.

Ten, the present invention's unique technology of utilizing the gas assisted molding maturation process to be combined with the water shaping characteristics to form, it is too complicated to have solved existing equipment, has also taked unnecessary closed loop accurately to control to water temperature, makes the problem of equipment manufacturing cost costliness.And compare assisted injection molding techniques nitrogen use amount seldom, the aqueous medium large usage quantity, and aqueous medium is easy to obtain, and can reuse.The present invention has working stability, characteristics such as reliability height, security is good, simple in structure, control is easy, installation/easy to maintenance, cost is low.

11, equipment of the present invention is applicable to all water aided injection forming technology.

Claims (2)

1. constant voltage water aided injection forming device, comprise controller of plastic injection molding (23) and be installed in mould (26) the interior telescopic air tube of hydraulic control (24) and liquid drugs injection (25), described controller of plastic injection molding (23) linker controller (19), one end of the telescopic air tube of described hydraulic control (24) stretches in spill cavity (26-A) or the die cavity (26-B), one end of described liquid drugs injection (25) stretches in die cavity (26-B) or the mould runner, it is characterized in that: described liquid drugs injection (25) also connects gas injection pressure close loop control circuit (49) respectively, water injection pressure close loop control circuit (50) and step-down close loop control circuit (51), the telescopic air tube of described hydraulic control (24) connects compressed air drainage cell (52);
Described gas injection pressure close loop control circuit (49) is by elevated pressure nitrogen source of the gas (2), high pressure nitrogen stop valve (5), high pressure nitrogen filter (8), gas injection high-pressure solenoid valve (13), high-voltage electric air valve (15), pressure sensor (18) and cyclelog (19) are formed, described elevated pressure nitrogen source of the gas (2) is through high pressure nitrogen stop valve (5), high pressure nitrogen filter (8) connects the entrance of gas injection high-pressure solenoid valve (13), the outlet of gas injection high-pressure solenoid valve (13) is joined through high-voltage electric air valve (15) and liquid drugs injection (25), liquid drugs injection (25) communicates with plastic cement melt (26-C) inside in the die cavity (26-B), connect pressure sensor (18) between high-voltage electric air valve (15) and the liquid drugs injection (25), described pressure sensor (18) connects the input of cyclelog (19), and the output of described cyclelog (19) connects gas injection high-pressure solenoid valve (13) and high-voltage electric air valve (15) respectively; Cyclelog (19) receives the injection end signal that controller of plastic injection molding (23) sends, just water is assisted the technology sign on, pressure sensor (18) feeds back to the outlet pressure of real-time detected high-voltage electric air valve (15) input of cyclelog (19), export corresponding signal through the output of cyclelog (19) and control the outlet pressure that high-voltage electric air valve (15) are adjusted in the action of gas injection high-pressure solenoid valve (13) and high-voltage electric air valve (15) respectively, the pressure of nitrogen injection (26-D) just, liquid drugs injection (25) injects interior plastic cement melt (26-C) inside of die cavity (26-B) with the small amount of nitrogen (26-D) of pressure controlled system, acts on plastic cement melt (26-C) inside and carries out the preformed of plastic hollow;
Described water injection pressure close loop control circuit (50) is by high-pressure water (1), water under high pressure stop valve (4), water under high pressure filter (7), water filling accumulator (10), water filling high-pressure solenoid valve (11), Flow-rate adjustment magnetic valve (12), high-voltage electric water valve (17), pressure sensor (18) and cyclelog (19) are formed, described high-pressure water (1) is through water under high pressure stop valve (4), water under high pressure filter (7) connects water filling accumulator (10), the entrance of water filling high-pressure solenoid valve (11) and Flow-rate adjustment magnetic valve (12), the outlet of water filling high-pressure solenoid valve (11) and Flow-rate adjustment magnetic valve (12) is connected with the entrance of high-voltage electric water valve (17), the outlet water receiving pin (25) of high-voltage electric water valve (17), connect pressure sensor (18) between high-voltage electric water valve (17) and the liquid drugs injection (25), the output of described cyclelog (19) connects water filling high-pressure solenoid valve (11) respectively, Flow-rate adjustment magnetic valve (12) and high-voltage electric water valve (17); The outlet pressure of pressure sensor (18) the real-time detected high-voltage electric water valve of feedback (17) is to the input of cyclelog (19), export corresponding signal through the output of cyclelog (19) and control water filling high-pressure solenoid valve (11) respectively, outlet pressure and the flow of high-voltage electric water valve (17) adjusted in Flow-rate adjustment magnetic valve (12) and high-voltage electric water valve (17) action, just inject pressure and the flow of water (26-E), liquid drugs injection (25) injects interior plastic cement melt (26-C) inside of die cavity (26-B) with the continuous water (26-E) of pressure and flow rates controlled system, act on plastic cement melt (26-C) inside, promote a small amount of nitrogen injection in forward position (26-D), finish the hollow molding of plastic jointly, pressurize and cooling and shaping process;
Described step-down close loop control circuit (51) is made up of step-down magnetic valve (20), filter (21), water tank (22), pressure sensor (18) and cyclelog (19), the described liquid drugs injection (25) that is installed in the mould (26) is connected with the entrance of step-down magnetic valve (20) through filter (21), the outlet water receiving case (22) of step-down magnetic valve (20), connect pressure sensor (18) between filter (21) and the liquid drugs injection (25), the output termination step-down magnetic valve (20) of described cyclelog (19); Pressure sensor (18) feedback real-time detected filter (21) inlet pressure is to the input of cyclelog (19), export the inlet pressure that filter (21) are adjusted in (20) draining of corresponding signal controlling step-down magnetic valve or exhaust through the output of cyclelog (19), just inject the pressure of water (26-E) or nitrogen injection (26-D) in the die cavity (26-B), the water of discharging directly enters water tank (22), the direct emptying of the nitrogen of discharge;
Described compressed air drainage cell (52) is by compressed air source (3), compressed air stop valve (6), compressed-air filter (9), gas injection magnetic valve (14), first check valve (16) and cyclelog (19) are formed, the compressed air cutoff valve of described compressed air source (3) (6), compressed-air filter (9) connects the entrance of gas injection magnetic valve (14), the outlet of gas injection magnetic valve (14) is connected with the telescopic air tube of hydraulic control (24) through first check valve (16), can stretching in spill cavity (26-A) or the die cavity (26-B) during work, solidifying and setting is the inside of plastic (26-F), communicate the output termination gas injection magnetic valve (14) of described cyclelog (19) with plastic (26-F) inside; When treating that drainage and step-down arrives setting value, cyclelog (19) is opened through output control gas injection magnetic valve (14), compressed air (26-G) enters the inside of plastic (26-F) in the die cavity (26-B) through the telescopic air tube of hydraulic control (24), and residual injection water (26-E) is flow back to water tank (22) through step-down close loop control circuit (51) from the inside of plastic (26-F);
Described high-pressure water (1) is provided by hydraulic pressure generating means (48), comprise industrial high-pressure hydraulic pump (30), pump front filter (31), safety valve (32), pump after-filter (33), motor (34), second check valve (35), pressure is kept and unidirectional combination valve (36), pressure switch (37), water under high pressure accumulator (38), stop valve (39), hydraulic controller (40), water tank (22), described industrial high-pressure hydraulic pump (30) entrance that is driven by motor (34) is through pump front filter (31) water receiving case (22), industry high-pressure hydraulic pump (30) outlet is through pump after-filter (33), second check valve (35), pressure is kept with unidirectional combination valve (36) and is connect pressure switch (37), the entrance of water under high pressure accumulator (38) and stop valve (39), the outlet of stop valve (39) connects the entrance of water injection pressure close loop control circuit (50) mesohigh water stop valve (4), the continuous high-pressure water of big flow (1) is provided, industry high-pressure hydraulic pump (30) outlet also takes back water tank (22) through safety valve (32), the input of pressure switch (37) water receiving pressure-controlled device (40), the output termination motor (34) of hydraulic controller (40); Pressure switch (37) is used for detecting in real time the pressure of water under high pressure accumulator (38), when the pressure of water under high pressure accumulator (38) reaches setting value, send the input that feeds back signal to hydraulic controller (40), output control motor (34) action by hydraulic controller (40) utilizes safety valve (32), pressure is kept with unidirectional combination valve (36) and the variable hydraulic pressure control of water under high pressure accumulator (38) realization and guarantees this device security of operation;
Described liquid drugs injection (25) can also be connected with and vacuumize drainage cell (53), the described drainage cell (53) that vacuumizes is by vacuum source (42), vacuum tank (43), vacuum transfer valve (44), vacuum pressure switch (45), vacuum electric ball valve (46), vacuum filter (47) and cyclelog (19) are formed, described vacuum source (42) and vacuum tank (43), the outlet of vacuum transfer valve (44) is connected, the entrance of vacuum transfer valve (44) is through vacuum electric ball valve (46), vacuum filter (47) water receiving pin (25), be connected to vacuum pressure switch (45) between vacuum transfer valve (44) and the vacuum electric ball valve (46), vacuum pressure switch (45) connects the input of cyclelog (19), and the output of cyclelog (19) connects vacuum transfer valve (44) and vacuum electric ball valve (46) respectively; Vacuum pressure switch (45) is used for detecting in real time the inner evacuated pressure of plastic (26-F), and send the input that feeds back signal to cyclelog (19), control vacuum transfer valve (44) and vacuum electric ball valve (46) action respectively through the output of cyclelog (19), residual injection water (26-E) is drained from plastic (26-F) inside through liquid drugs injection (25), vacuum filter (47);
Described elevated pressure nitrogen source of the gas (2) is provided by the gas pressure booster of gas assisted molding, and compressed air source (3) is provided by the industrial air compressor, and vacuum source (42) is provided by vavuum pump.
2. water shaping technology that adopts the described constant voltage water aided injection forming device of claim 1 may further comprise the steps:
A. at first, by controller of plastic injection molding (23) control injection mechanism of injection machine (23-A) plastic cement melt (26-C) is injected in the die cavity (26-B), makes to be full of or to be full of substantially plastic cement melt (26-C) in the die cavity;
B. cyclelog (19) receives the injection end signal that controller of plastic injection molding (23) sends, just water is assisted the technology sign on, the unlatching of each sequential process in the control water shaping technology, hydraulic control runner stop valve (27) is closed, the small amount of nitrogen (26-D) that to be controlled automatically time and pressure by gas injection pressure close loop control circuit (49) is in liquid drugs injection (25) injects die cavity (26-B) plastic cement melt (26-C), force that the hydraulic control overflow shutoff valve (28) of some plastic cement melts (26-C) through opening enters spill cavity (26-A) in the die cavity from die cavity, carry out the hollow preformed process of plastic;
C. will carry out the segmentation back of water under high pressure (26-E) nitrogen injection (26-D) in liquid drugs injection (25) is injected into die cavity (26-B) of control automatically to time, pressure and flow by water injection pressure close loop control circuit (50), the mobile mold filling of the plastic cement melt (26-C) that promotion contacts with the nitrogen injection forward position, further force the hydraulic control overflow shutoff valve (28) of some melts through opening from die cavity, to enter spill cavity (26-A), finish the hollow molding process of plastic;
D. the water under high pressure (26-E) that is continued to control automatically time, pressure and flow by water injection pressure close loop control circuit (50) is in liquid drugs injection (25) is injected into die cavity (26-B), guarantee plastic cement melt (26-C) in cooling curing, volume contraction process the pressure stability in the die cavity in setting value;
E. after the typing of plastic cement melt (26-C) cooling curing in the die cavity (26-B), discharged by the injection water (26-E) in step-down close loop control circuit (51) the control die cavity, the pressure in the die cavity is reduced to setting value;
F. the telescopic air tube of hydraulic control (24) stretches in spill cavity (26-A) or the die cavity (26-B) in the plastic of solidifying and setting (26-F), by compressed air drainage cell (52) compressed air (26-G) is imported in the plastic through the telescopic air tube of hydraulic control, injection water (26-E) residual in the plastic is drained; Also can utilize and vacuumize drainage cell (53) injection water residual in the plastic is drained;
G. controller of plastic injection molding (23) is controlled the die opening and closing mechanism opening mould (26) of injection machine, and (26-F) ejects with plastic;
H. controller of plastic injection molding (23) is controlled the die opening and closing mechanism closed die (26) of injection machine, and the telescopic air tube of hydraulic control (24), hydraulic control runner stop valve (27) and hydraulic control overflow shutoff valve (28) reset, and enter next injection molding cycle;
At mould (26) the telescopic air tube of more than one hydraulic control (24), liquid drugs injection (25), spill cavity (26-A) hydraulic control runner stop valve (27) and hydraulic control overflow shutoff valve (28) are set, the action of the telescopic air tube of described hydraulic control, hydraulic control runner stop valve and hydraulic control overflow shutoff valve provides control signal by cyclelog (19), is carried out by hydraulic system or the external HYDRAULIC CONTROL SYSTEM of injection machine.
CN 201110207388 2011-07-22 2011-07-22 Water-assisted molding process and constant pressure water-assisted injection molding equipment CN102285060B (en)

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