1. The utility model provides an energy-conserving injection molding machine with heat recovery function which characterized in that mainly includes: the injection molding machine comprises an injection molding machine main body, a charging barrel, a heater, a plasticizing coil, a hopper, a heat exchange barrel, a heat exchange coil, a fan, a heating pipe, a heating return pipe, a mold, a cooling return pipe, a cooling pipe, a circulating pump, a water tank coil, a heat pump, a throttle valve, a liquid tank and a compressor, wherein the left side of the injection molding machine is provided with a mold clamping mechanism, and the right side of the injection molding machine is provided with a plasticizing mechanism; the charging barrel is a screw charging barrel of the injection molding machine main body; the heater is a universal electric heating ring for the injection molding machine; the heaters are sleeved outside the front section and the middle section of the charging barrel; the plasticizing coil is a tightly wound spiral metal pipe and is sleeved on the rear section of the charging barrel from left to right; the hopper is an inverted cone-shaped cylindrical feeding hopper of the injection molding machine main body; the heat exchange cylinder is a metal cylinder, is fixed at the bottom of the hopper, axially extends along the left and right directions, and the right end of the heat exchange cylinder is communicated with the hopper; the heat exchange coil is a metal pipe spirally wound from left to right and is fixed inside the heat exchange cylinder, and the right end of the heat exchange coil is connected with the right end of the plasticizing coil; the fan is a motor-driven fan and is fixed at the left end of the heat exchange cylinder, and blows air towards the right direction towards the inside of the heat exchange cylinder; the heating pipe and the heating return pipe are metal pipes, the lower end of the heating pipe is connected with the leftmost end of the plasticizing coil pipe, and the lower end of the heating return pipe is connected with the leftmost end of the heat exchange coil pipe; the mould comprises a pair of moulds with cooling water circuits inside; the cooling return pipes and the cooling pipes are plastic hoses, two cooling pipes are arranged respectively, and the cooling water paths on the two molds are connected with the cooling return pipes and the cooling pipes respectively; the circulating pumps are two universal water pumps, one is arranged on each of the two cooling pipes, and the direction of water flow conveyed by the circulating pumps is that the water flow flows through the cooling pipes, then flows through the mold and then flows through the cooling return pipe; the water tank is made of metal and filled with water, and the bottom of the water tank is connected with the other ends of the cooling return pipe and the cooling pipe; the water tank coil is a metal coil and is immersed in the water tank; the heat pump consists of a throttle valve, a liquid tank and a compressor; wherein the throttle valve is a valve with a throttling function and the throttling opening can be finely adjusted; the liquid tank is a metal liquid storage tank, and a refrigeration medium which can be liquefied under pressure is filled in the liquid tank and is maintained under higher pressure; the compressor is a compressor capable of compressing a refrigerant medium; the left end of the throttle valve is connected with the upper end of the water tank coil pipe, and the right end of the throttle valve is connected with the liquid tank and is connected with the upper end of the heating return pipe through the liquid tank; the left end of the compressor is connected with the lower end of the water tank coil pipe, the right end of the compressor is connected with the upper end of the heating pipe, and the compression direction of the compressor is from left to right.

2. The energy-saving injection molding machine with the heat recovery function as claimed in claim 1, wherein: a left-and-right two-stage heat pump is used; or the heat pump is replaced by two heat pumps and a heat exchanger; the heat exchanger is a plate heat exchanger; in the left heat pump: the throttle valve and the left end of the compressor are connected with a water tank coil pipe; the liquid tank and the right end of the compressor are connected with a heat exchanger; in the heat pump on the right: the throttle valve and the left end of the compressor are connected with the heat exchanger; the right ends of the liquid tank and the compressor are respectively connected with a heating return pipe and a heating pipe.

Background

The injection molding machine is the most main equipment for producing plastic products with complex structures in large scale and plays an important role in national economy. Efficient production requires that the molding period is as short as possible, and the mold needs to be continuously cooled so that the plastic can be solidified and molded as soon as possible, so that a large amount of waste heat is wasted, and on the other hand, a plasticizing system of the injection molding machine needs to continuously heat and plasticize plastic particles and consumes huge electric energy, so that the energy utilization efficiency of the working mode is low.

In order to improve the energy utilization efficiency of the injection molding machine, CN208788935U uses a heat energy battery to recover the redundant heat emitted from the mold temperature controller and then supplies the redundant heat to an electronic system of the injection molding machine, but the prior thermal battery technology is not mature, the energy conversion efficiency is low, and only a small amount of energy can be recovered; CN109664461A introduces the recirculated cooling water of cooling injection molding machine aircraft nose into the storage vat, utilizes the heat of circulating water to preheat the plastics raw materials in the storage vat to realize energy-conserving purpose, but because the circulating water temperature is generally lower, this method is to the preheating effect of raw materials limited, also can only retrieve a small amount of energy. Therefore, at present, a means for effectively recycling the waste heat of the plastic products in the mold is urgently needed.

Disclosure of Invention

The invention provides an energy-saving injection molding machine with a heat recovery function, which is based on the principle of a heat pump, firstly, heat transferred to a mold by a material is absorbed by cooling water, then, the heat of the cooling water is transferred to a plasticizing system by the heat pump, the quality of the heat is improved, and the energy-saving injection molding machine is used for plasticizing raw material particles, so that the heat energy is recovered and reused; the heat pump also has the function of cooling water, so that the cooling efficiency of the die is improved. The waste heat after plasticizing is also used for preheating plastic raw material particles, so that the energy utilization efficiency is further improved; through the multi-stage heat pump series connection; the purpose of increasing the upper limit of the heating temperature is achieved; the opening of the throttle valve is adjusted to change the pressure and boiling point of the medium, so as to achieve the purpose of accurate temperature control.

In order to achieve the purpose, the invention adopts the technical scheme that:

the invention provides an energy-saving injection molding machine with a heat recovery function, which mainly comprises: the injection molding machine comprises an injection molding machine main body, a charging barrel, a heater, a plasticizing coil, a hopper, a heat exchange barrel, a heat exchange coil, a fan, a heating pipe, a heating return pipe, a mold, a cooling return pipe, a cooling pipe, a circulating pump, a water tank coil, a heat pump, a throttle valve, a liquid tank and a compressor, wherein the injection molding machine main body is a universal injection molding machine, the left side is a mold closing mechanism, the right side is a plasticizing mechanism, and except the structure specially explained in the patent, the rest structures are the same as the structure of the common injection molding machine; the charging barrel is a screw charging barrel of the injection molding machine main body; the heater is a universal electric heating ring for the injection molding machine; the front section and the middle section of the charging barrel are the same as those of a common injection molding machine, and a heater is sleeved outside the charging barrel; the plasticizing coil is a tightly wound spiral metal pipe and is sleeved on the rear section of the charging barrel from left to right; the hopper is an inverted cone-shaped cylindrical feeding hopper of the injection molding machine main body; the heat exchange cylinder is a metal cylinder, is fixed at the bottom of the hopper, axially extends along the left and right directions, and the right end of the heat exchange cylinder is communicated with the hopper; the heat exchange coil is a metal pipe spirally wound from left to right and is fixed inside the heat exchange cylinder, and the right end of the heat exchange coil is connected with the right end of the plasticizing coil; the fan is a motor-driven fan and is fixed at the left end of the heat exchange cylinder, and blows air towards the right direction towards the inside of the heat exchange cylinder; the heating pipe and the heating return pipe are metal pipes, the lower end of the heating pipe is connected with the leftmost end of the plasticizing coil pipe, and the lower end of the heating return pipe is connected with the leftmost end of the heat exchange coil pipe; the mold is a universal injection mold and comprises a pair of molds with cooling water loops inside; the cooling return pipes and the cooling pipes are plastic hoses, two cooling pipes are arranged respectively, and the cooling water paths on the two molds are connected with the cooling return pipes and the cooling pipes respectively; the circulating pumps are two universal water pumps, one is arranged on each of the two cooling pipes, and the direction of water flow conveyed by the circulating pumps is that the water flow flows through the cooling pipes, then flows through the mold and then flows through the cooling return pipe; the water tank is made of metal and filled with water, and the bottom of the water tank is connected with the other ends of the cooling return pipe and the cooling pipe; the water tank coil is a metal coil and is immersed in the water tank; the heat pump consists of a throttle valve, a liquid tank and a compressor; wherein the throttle valve is a valve with a throttling function and the throttling opening can be finely adjusted; the liquid tank is a metal liquid storage tank, and a refrigeration medium which can be liquefied under pressure is filled in the liquid tank and is maintained under higher pressure; the compressor is a compressor capable of compressing a refrigerant medium; the left end of the throttle valve is connected with the upper end of the water tank coil pipe, and the right end of the throttle valve is connected with the liquid tank and is connected with the upper end of the heating return pipe through the liquid tank; the left end of the compressor is connected with the lower end of the water tank coil pipe, the right end of the compressor is connected with the upper end of the heating pipe, and the compression direction of the compressor is from left to right.

In the injection molding process, the high-temperature plastic continuously conducts heat to the mold to cause the temperature of the mold to rise, the circulating pump operates to enable water in the water tank to continuously flow through the mold to reduce the temperature of the mold, and meanwhile, the temperature of the water in the water tank absorbs the heat is gradually increased; meanwhile, the refrigerant in the liquid tank flows through the throttle valve, and is gasified due to pressure reduction, and latent heat of vaporization is absorbed to cause temperature reduction; the low-temperature gaseous refrigeration medium continuously flows through the coil pipe of the water tank to absorb the heat of water in the water tank, then the refrigeration medium passes through the compressor and is compressed and liquefied by the compressor, and the liquid temperature is raised to extremely high temperature due to the release of latent heat of vaporization; the liquid high-temperature refrigeration medium flows through the plasticizing coil pipe, and transmits the temperature to the rear section of the charging barrel, so that the temperature of the plastic in the charging barrel is raised, and the plasticizing is realized; the temperature of the refrigerating medium is reduced after passing through the plasticizing coil pipe, but the refrigerating medium is kept at a higher temperature, and the refrigerating medium enters the heat exchange coil pipe, so that the air blown by the fan is heated, on one hand, the air is enabled to cool the refrigerating medium, on the other hand, the heated hot air enters the hopper and heats the plastic particles stored in the hopper, and the preheating effect is achieved; the cooled liquid refrigeration medium returns to the liquid tank along the heating return pipe to complete circulation; in the circulation, the refrigeration medium absorbs the heat of the water in the water tank, and the heat is used for heating the rear section of the charging barrel and the plastic particles in the hopper, so that the waste heat is recycled, and the energy-saving effect is achieved.

The invention provides an energy-saving injection molding machine with a heat recovery function, which can use a left-stage heat pump and a right-stage heat pump; the heat pump can be replaced by two heat pumps and a heat exchanger; the heat exchanger may be a plate heat exchanger; in the left heat pump: the throttle valve and the left end of the compressor are connected with a water tank coil pipe; the liquid tank and the right end of the compressor are connected with a heat exchanger; in the heat pump on the right: the throttle valve and the left end of the compressor are connected with the heat exchanger; the right ends of the liquid tank and the compressor are respectively connected with a heating return pipe and a heating pipe.

The heat pump on the left side absorbs the heat of water in the water tank, the temperature is increased and is transmitted to the heat pump on the right side through the heat exchanger, the temperature is further increased by the heat pump on the right side, the heat is transmitted to a plasticizing system of the injection molding machine, and the upper limit of the temperature which can be reached by the plasticizing system is increased through the two stages of heat pumps.

The invention provides an energy-saving injection molding machine with a heat recovery function, which can change the liquefaction temperature of a compressed refrigerant by adjusting the opening of a throttle valve so as to adjust the temperature of a plasticizing system.

The device provided by the invention uses the waste heat after plasticization for preheating the plastic raw material particles, so that the energy utilization efficiency is further improved; through the multi-stage heat pump series connection; the upper limit of the heating temperature is increased; the opening degree of the throttle valve is adjusted, the pressure and the boiling point of the medium are changed, and accurate temperature control is realized.

Drawings

FIG. 1 is a schematic overall view of an energy-saving injection molding machine with heat recovery function according to the present invention;

FIG. 2 is a schematic diagram of a heat pump of an energy-saving injection molding machine with a heat recovery function according to the invention;

FIG. 3 is a schematic diagram of a two-stage heat pump of an energy-saving injection molding machine with a heat recovery function according to the present invention.

In the figure: 1-an injection molding machine main body, 2-a charging barrel, 3-a heater, 4-a plasticizing coil, 5-a hopper, 6-a heat exchange barrel, 7-a heat exchange coil, 8-a fan, 9-a heating pipe, 10-a heating return pipe, 11-a mold, 12-a cooling return pipe, 13-a cooling pipe, 14-a circulating pump, 15-a water tank, 16-a water tank coil, 17-a heat pump, 18-a throttling valve, 19-a liquid tank, 20-a compressor and 21-a heat exchanger.

Detailed Description

The invention provides an energy-saving injection molding machine with a heat recovery function, as shown in figures 1 and 2, the device mainly comprises: the injection molding machine comprises an injection molding machine body 1, a charging barrel 2, a heater 3, a plasticizing coil 4, a hopper 5, a heat exchange barrel 6, a heat exchange coil 7, a fan 8, a heating pipe 9, a heating return pipe 10, a mold 11, a cooling return pipe 12, a cooling pipe 13, a circulating pump 14, a water tank 15, a water tank coil 16, a heat pump 17, a throttle valve 18, a liquid tank 19 and a compressor 20. The injection molding machine main body 1 is a general injection molding machine, the left side is a mold closing mechanism, the right side is a plasticizing mechanism, and the rest structures are the same as the structures of the general injection molding machine except the structure specifically described in the patent; the charging barrel 2 is a screw charging barrel of the injection molding machine main body 1; the heater 3 is a universal electric heating ring for an injection molding machine; the front section and the middle section of the charging barrel 2 are the same as those of a common injection molding machine, and a heater 3 is sleeved outside the charging barrel; the plasticizing coil 4 is a tightly wound spiral metal pipe and is sleeved on the rear section of the charging barrel 2 from left to right; the hopper 5 is an inverted cone-shaped cylindrical feeding hopper of the injection molding machine main body 1; the heat exchange cylinder 6 is a metal cylinder, is fixed at the bottom of the hopper 5, axially extends along the left and right directions, and the right end of the heat exchange cylinder is communicated with the hopper 5; the heat exchange coil 7 is a metal pipe spirally wound from left to right and is fixed inside the heat exchange cylinder 6, and the right end of the heat exchange coil 7 is connected with the right end of the plasticizing coil 4; the fan 8 is a fan driven by a motor, is fixed at the left end of the heat exchange cylinder 6 and blows air towards the right to the inside of the heat exchange cylinder 6; the heating pipe 9 and the heating return pipe 10 are both metal pipes, the lower end of the heating pipe 9 is connected with the leftmost end of the plasticizing coil 4, and the lower end of the heating return pipe 10 is connected with the leftmost end of the heat exchange coil 7; the mold 11 is a general injection mold comprising a pair of molds with cooling water circuits inside; the cooling return pipes 12 and the cooling pipes 13 are plastic hoses, two cooling water paths are arranged on each of the two cooling return pipes 12 and the two cooling pipes 13, and the cooling water paths on the 2 molds are respectively connected with the cooling return pipes 12 and the cooling pipes 13; the circulating pump 14 is a universal water pump, two circulating pumps are provided, one is arranged on each of the two cooling pipes 13, and the direction of water flow conveyed by the circulating pump 14 is that the water flow flows through the cooling pipes 13, then flows through the mold and then flows through the cooling return pipe 12; the water tank 15 is made of metal and filled with water, and the bottom of the water tank 15 is connected with the other ends of the cooling return pipe 12 and the cooling pipe 13; the tank coil 16 is a metal coil, which is immersed in the water in the tank 15; the heat pump 17 is shown in fig. 2 and is composed of a throttle valve 18, a liquid tank 19 and a compressor 20; wherein the throttle valve 18 is a valve having a throttling function and a throttle opening degree of which can be finely adjusted; the liquid tank 19 is a metal liquid tank filled with a refrigerant that can be liquefied under pressure and maintained at a higher pressure; the compressor 20 is a compressor capable of compressing a refrigerant medium; the left end of the throttle valve 18 is connected with the upper end of the water tank coil pipe 16, the right end of the throttle valve is connected with the liquid tank 19, and the throttle valve is connected with the upper end of the heating return pipe 10 through the liquid tank 19; the left end of the compressor 20 is connected with the lower end of the water tank coil 16, the right end is connected with the upper end of the heating pipe 9, and the compression direction of the compressor is from left to right.

In the injection molding process, the high-temperature plastic continuously conducts heat to the mold 11 to cause the temperature of the mold 11 to rise, the circulating pump 14 operates to enable water in the water tank 15 to continuously flow through the mold 11 to reduce the temperature of the mold 11, and meanwhile, the temperature of the water in the water tank 15 gradually rises after absorbing the heat; at the same time, the refrigerant medium in the tank 19 flows through the throttle valve 18, and is vaporized due to a pressure decrease, absorbing latent heat of vaporization, resulting in a temperature decrease; the low-temperature gaseous refrigerant continuously flows through the water tank coil 16 to absorb the heat of water in the water tank 15, and then the refrigerant passes through the compressor 20 to be compressed and liquefied by the compressor 20, and the liquid temperature is raised to extremely high temperature due to the release of latent heat of vaporization; the liquid high-temperature refrigeration medium then flows through the plasticizing coil 4, and transmits the temperature to the rear section of the charging barrel 2, so that the temperature of the plastic in the charging barrel 2 is raised, and thus, the plasticizing is realized; the temperature of the refrigerating medium 4 is reduced after passing through the plasticizing coil 4, but the refrigerating medium is kept at a higher temperature, and the refrigerating medium enters the heat exchange coil 7 and heats air blown by the fan 8, so that the air cools the refrigerating medium 4 on one hand, and heated hot air enters the hopper 5 to heat plastic particles stored in the hopper on the other hand, and the preheating effect is achieved; the cooled liquid refrigeration medium returns to the liquid tank 19 along the heating return pipe 10 to complete circulation; in this cycle, the refrigeration medium absorbs the heat of the water in the water tank 15 for heating the rear section of the charging barrel 2 and the plastic particles in the hopper 5, thereby realizing the recycling of the waste heat and achieving the effect of energy conservation.

The invention provides an energy-saving injection molding machine with a heat recovery function, which can use a left-stage heat pump and a right-stage heat pump; as shown in fig. 3, the heat pump 17 may be replaced with two heat pumps 17 and one heat exchanger 21; the heat exchanger 21 may be a plate heat exchanger; in the heat pump 17 on the left: the throttle valve 18 and the left end of the compressor 20 are connected with the water tank coil 16; the right ends of the liquid tank 19 and the compressor 20 are connected with a heat exchanger 21; in the heat pump 17 on the right: the throttle valve 18 and the left end of the compressor 20 are connected with a heat exchanger 21; the right ends of the liquid tank 19 and the compressor 20 are respectively connected with the heating return pipe 10 and the heating pipe 9.

The left heat pump 17 absorbs the heat of the water in the water tank 15, the temperature is increased and is transmitted to the right heat pump through the heat exchanger 21, the temperature is further increased by the right heat pump and is transmitted to a plasticizing system of the injection molding machine, and the upper limit of the temperature which can be reached by the plasticizing system is increased through the two stages of heat pumps.

The invention provides an energy-saving injection molding machine with a heat recovery function, which can change the liquefaction temperature of a compressed refrigerant by adjusting the opening of a throttle valve 18 so as to adjust a plasticizing system.