JP4701022B2 - Mold temperature controller - Google Patents

Description

  The present invention relates to an apparatus for adjusting a mold temperature by circulating a heat medium in a mold such as a plastic molding machine.

  2. Description of the Related Art Conventionally, there is known a mold temperature control device that includes a heater that heats a heat medium and a cooler that cools the heat medium. For example, in the mold temperature control device 50 of Patent Document 1 shown in FIG. 6, the medium tank 51 is configured to be double inside and outside by a heater 52 and a cooler 53, and the heater 54 and the communication hole 55 are connected to the inner heater 52. And a heat medium inflow pipe 56, a cooling water inflow pipe 57 is connected to the outer cooler 53, the heat medium and the cooling water are mixed inside the heater 52, and the temperature adjusted heat medium is pumped by the pump 58. It is configured to feed the mold M.

7 includes a heater 62 and a cooler 63 built in a medium tank 61, and a refrigerant gas inflow pipe 64 and an outflow pipe 65 are connected to the cooler 63. It is configured. The mold temperature adjusting device of Patent Document 3 is configured by providing a heat exchange pipe in a cold water tank of a cooler and providing a heater and a water treatment device on the downstream side of the cooler.
Japanese Patent No. 2668755 Japanese Patent Laid-Open No. 11-286019 Japanese Patent Laid-Open No. 2005-21979

  However, according to the mold temperature control device 50 of Patent Document 1, since the cooler 53 is placed outside the heater 52, there is a problem that the medium tank 51 is enlarged. Also, according to the cooling method in which the heat medium is filled with cooling water, an amount of heat medium corresponding to the amount of cooling water supplied is always discharged from the drain pipe 59, so impurities such as mineral components and scale in the heat medium It was necessary to separately install a wastewater treatment device for removing water.

  In the mold temperature control device 60 of Patent Document 2, since the cooler 63 is installed in the medium tank 61 together with the heater 62, not only the medium tank 61 is increased in size but also a large amount of heat medium is brought to a required temperature. There was a problem that it took a long time to lower. The conventional device of Patent Document 3 requires a dedicated chilled water tank for the cooler and also needs to be equipped with an expensive device for water treatment.

  An object of the present invention is to solve the above-mentioned problems and to provide a mold temperature control device capable of efficiently cooling a heat medium circulated in a mold with a small cooler.

In order to solve the above-described problems, a mold temperature adjusting device according to the present invention is a device for adjusting a mold temperature by circulating a heat medium in a mold, and the heat medium passes through a cooler that cools the heat medium. The medium pipe is an outer pipe, and the cooling pipe through which cooling water passes is an inner pipe .

Further, a more preferable mold temperature control device is a device for adjusting the mold temperature by circulating a heat medium through the mold, and a medium pipe through which the heat medium passes inside the casing, and a heat medium on the medium pipe. A medium tank for storing the heat medium, a heater for heating the heat medium, a cooler for cooling the heat medium, and a pump for feeding the heat medium to the mold, and the cooler is connected to the medium pipe. It is characterized in that it is configured as a double pipe having an outer pipe as an outer part and a cooling pipe through which cooling water passes as an inner pipe .

Here, the cooler functions as a heat exchanger that performs heat exchange between the heat medium flowing through the medium pipe and the cooling water flowing through the cooling pipe. The combination of the medium pipe and the cooling pipe, by a double tube inserted through the medium body piping and outer tube cooling pipes on the inside as the inner tube, it is easy to remove scale adhered to the inner surface of the cooling pipe. That is, since cooling water (mainly tap water or well water) passes through the cooling pipe, the scale adheres to the inner surface thereof. In this scale, for example, a cleaning material such as a sponge ball is put into a pipe and removed by applying water pressure. In this case, the flow of the cleaning material is improved when the cooling pipe is the inner pipe. The inner tube and the outer tube are preferably concentric, but may be eccentric.

  Although it does not specifically limit as a heat medium, It is preferable to use the liquid (for example, propylene glycol or its aqueous solution) which has the rust prevention property and corrosion resistance which are hard to attach a scale (for example, water). In this case, even if the medium pipe is an outer pipe, the problem of difficulty in removing the scale does not basically occur.

  In order for the cooler to efficiently perform heat exchange in a limited space of the casing, it is preferable to lengthen the entire length of the cooler. From this point of view, the cooler preferably has a structure in which a double pipe composed of a part of the medium pipe and the cooling pipe is wound, for example, in a coil shape or a zigzag meander structure.

  In addition, the mold temperature control apparatus of the present invention includes a casing, an inlet for pressurized air, an air pipe for connecting the inlet to the medium pipe, and a pressure so that the heat medium can be easily removed when necessary. It is preferable to provide a medium outlet for extracting the heat medium urged by air from the medium pipe.

According to the mold temperature control apparatus of the present invention, since the cooler is configured as a double pipe having the medium pipe as the outer pipe and the cooling pipe as the inner pipe , the cooler itself can be reduced in size and the cooler can be used as the medium. The entire apparatus can be made compact by separating from the tank and the heater. In addition, the heat exchange efficiency between the heat medium and the cooling water can be increased, the heat medium can be cooled in a short time, and clean cooling water can be discharged while avoiding mixing of the heat medium and the cooling water. Furthermore, it becomes easy to remove the scale adhering to the inner surface of the cooling pipe.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 4, the mold temperature adjusting apparatus 1 of this embodiment is an apparatus for adjusting a mold temperature by circulating a heat medium through a mold M of a plastic injection molding machine. A medium pipe 8 through which a heat medium passes is provided. On the medium pipe 8, a medium tank 9 that stores the heat medium H, a heater 10 that heats the heat medium H, a cooler 11 that cools the heat medium H, and the heat medium H is fed to the mold M. And a pump 12 is disposed. The cooler 11 is configured in an inner and outer double coil shape by a part of the medium pipe 8 and a cooling pipe 44 through which cooling water passes.

  Next, an embodiment of the present invention will be described in detail with reference to FIGS. As shown in FIG. 1, a mold temperature adjusting device 1 of this embodiment is installed in the vicinity of an injection molding machine 2 for plastic products. In a molding factory equipped with a plurality of injection molding machines 2, a mold temperature control device 1 is installed for each molding machine 2. Between the mold temperature control device 1 and the injection molding machine 2, a heat medium circulation line 3 is piped, and the mold temperature control device 1 circulates the heat medium to the mold M of the injection molding machine 2 to make plastic. The temperature of the mold M is adjusted according to the material or type of the product.

  As shown in FIGS. 2 and 3, the mold temperature control apparatus 1 includes a rectangular box-shaped casing 5. An operation panel 6 is provided on the front surface of the casing 5, and casters 7 are attached to the lower surface. Inside the casing 5, there are a medium pipe 8 through which the heat medium passes, a medium tank 9 with a lid for storing the heat medium, a heater 10 for heating the heat medium, a cooler 11 for cooling the heat medium, and heat. A pump 12 for feeding the medium to the mold M is provided. As the heat medium, an aqueous propylene glycol solution that suppresses adhesion of impurities such as rust and scale is used. The medium tank 9 and the cooler 11 are installed in the upper part of the casing 5, and the heater 10 and the pump 12 are installed in the lower part of the casing 5.

  On the back surface of the casing 5, a manifold 14 for sending a heat medium to the mold M, a manifold 15 for returning a medium to be returned from the mold M, a cooling water inlet 16 for introducing cooling water, A cooling water outlet 17 for discharging water and an air inlet 18 for introducing pressurized air are provided. A ball valve 20 that opens and closes the medium outlet 19 is provided in the medium supply manifold 14, and a ball valve 22 that opens and closes the medium inlet 21 is provided in the medium return manifold 15. The cooling water inlet 16 is connected to a fresh water supply source such as tap water or well water, and the air inlet 18 is connected to a pressurized air supply source such as a compressor. A medium extraction port 23 for extracting the gas-liquid mixed medium urged by the pressurized air from the medium pipe 8 is provided at the lower side of the casing 5.

  As shown in FIG. 4, the medium tank 9 is provided with an upper limit switch 25, a warning switch 26, and a lower limit switch 27 that detect the water level of the heat medium H in three stages. The heater 10 includes a vertically long heater tank 28, and a heat generating portion 30 of a plug heater 29 is inserted into the tank 28, and an overheat preventer 31 is attached to the outer surface of the tank 28.

  The medium pipe 8 includes a supply pipe 32 that supplies the heating medium H of the medium tank 9 to the heater 10, an outflow pipe 33 that extends between the heater 10 and the medium outlet 19 of the medium feeding manifold 14, and a return medium. The return pipe 34 extending between the medium inlet 21 of the manifold 15 and the heater 10, the overflow pipe 35 for returning the excess medium of the heater 10 to the medium tank 9, and the forward pipe 33 are connected to the reflux pipe 34. The pressure adjusting pipe 36 is composed of a discharge pipe 37 that connects the forward flow pipe 33 to the medium outlet 23.

  On the forward flow pipe 33, the ball valve 20 of the pump 12, the check valve 39, the pressure gauge 40, the medium temperature detector 41, and the medium feeding manifold 14 is disposed. One end of the pressure adjusting pipe 36 is connected to the forward flow pipe 33 between the pump 12 and the check valve 39, and a pressure adjusting valve 42 for adjusting the supply pressure of the heat medium is provided on the pressure adjusting pipe 36. The discharge pipe 37 is connected to the forward flow pipe 33 between the heater 10 and the pump 12, and a plug 43 (see FIG. 2) or a ball valve is provided at the medium extraction port 23. On the reflux pipe 34, the ball valve 22 of the return manifold 15 and the cooler 11 are provided, and the other end of the pressure regulating pipe 36 is connected to the reflux pipe 34 between the cooler 11 and the heater 10. Yes.

  The cooler 11 is configured as an inner / outer double pipe having a part 34a of the reflux pipe 34 as an outer pipe and a cooling pipe 44 as an inner pipe passing through the inner pipe and the outer pipe. As shown in FIG. 5, the cooler 11 of this embodiment is formed in a rectangular coil shape by winding the double pipe several times (for example, 2 to 5 times), and is adjacent to the side of the medium tank 9. In the casing 5 (see FIGS. 2 and 3). One end of the cooling pipe 44 is connected to the cooling water inlet 16 and the other end is connected to the cooling water outlet 17 (see FIG. 4). The cooling water inlet 16 is provided with an electromagnetic valve 45 that adjusts the inflow amount of the cooling water. Then, the cooler 11 functions as a heat exchanger, and in part 34a of the reflux pipe 34, the heat of the high-temperature medium refluxed from the mold M is taken away by the cooling water, and the medium temperature is lowered to a required value. Yes.

  On the other hand, one end of an air pipe 46 is connected to the pressurized air inlet 18, and the other end is connected to the forward pipe 33 between the check valve 39 and the pressure gauge 40. A pressure switch 47 that opens and closes the air inlet 18, an electromagnetic valve 48 that adjusts the inflow pressure of the pressurized air, and a check valve 49 that prevents the backflow of the gas-liquid mixed medium are disposed on the air pipe 46. Has been. Since the scale is difficult to attach to the inner surface of the medium pipe 8 through which the aqueous propylene glycol solution passes, there is almost no need for cleaning. However, when it is necessary to remove the heat medium due to the time for replacement, etc., pressurized air is injected into the medium pipe 8, and the gas-liquid mixed medium is used as the mold M, the circulation pipe 3, the reflux pipe 34, and the cooler 11. The heat medium is circulated through the heater 10 at a high speed so that the heat medium can be discharged from the medium outlet 23 to the outside of the casing 5.

  On the other hand, since the scale is easily attached to the inner surface of the cooling pipe 44 through which cooling water such as tap water passes, it is sometimes necessary to clean it. This cleaning is performed by a method such as mixing a cleaning material such as a sponge ball with cooling water and applying water pressure.

Since the mold temperature control apparatus 1 of this embodiment is configured as described above, the following effects are exhibited.
(A) A part 34a of the reflux pipe 34 constituting the medium pipe 8 is used, and a cooling pipe 44 is passed through the inside 34a. The cooler 11 can be made compact by this double pipe.
(B) With the double pipe, heat exchange can be efficiently performed between the heat medium and the cooling water, and the high-temperature reflux medium from the mold M can be cooled in a short time.
(C) The double pipe can be wound, for example, in a coil shape, and the overall length of the cooler 11 can be increased to further increase the heat exchange efficiency.
(D) It is possible to avoid mixing the heat medium and the cooling water, circulate and use the heat medium, discharge only clean cooling water, and eliminate the need for a separate water treatment device.

(E) Since the cooling pipe 44 is an inner pipe, the flow of a cleaning material such as a sponge ball is good, and the inner surface can be easily cleaned.
(F) The cooler 11 is separated from the medium tank 9 and the heater 10, the medium tank 9 and the heater 10 are both downsized, and the cooler 11 is compactly accommodated in a limited space of the casing 5. Can be configured compactly.
(G) A cleaning function using pressurized air is added to the mold temperature control device 1 so that the piping equipment in the entire heat medium circulation path in the plastic injection molding machine 2 can be efficiently cleaned at once.

The present invention is not limited to the above-described embodiments. For example, as described below, the present invention can be appropriately modified and embodied without departing from the spirit of the invention.
(1) The double pipe is meandered in a zigzag manner in one plane, and the cooler 11 is configured to be thin.
(2) Two sets of piping equipment shown in FIG. 4 are installed inside one casing 5 so that the temperature of the molds M of the two injection molding machines 2 can be adjusted with one mold temperature control device 1. Configure.

It is a layout view of a mold temperature control device showing an embodiment of the present invention. It is a perspective view which shows the internal structure of the metal mold | die temperature control apparatus of FIG. It is a top view of the metal mold | die temperature control apparatus of FIG. It is a circuit diagram which shows the piping structure of the metal mold | die temperature control apparatus of FIG. It is a perspective view which shows the cooler of the metal mold | die temperature control apparatus of FIG. It is a circuit diagram which shows the conventional metal mold | die temperature control apparatus. It is a circuit diagram which shows another conventional mold temperature control apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mold temperature control apparatus 2 Injection molding machine 3 Circulation line 5 Casing 8 Medium piping 9 Medium tank 10 Heater 11 Cooler 12 Pump 16 Cooling water inlet 17 Cooling water outlet 18 Air inlet 19 Medium outlet 21 Medium inlet 23 Medium Extraction port 33 Outflow pipe 34 Reflux pipe 44 Cooling pipe 46 Air pipe M Mold

Claims (4)

In an apparatus for adjusting a mold temperature by circulating a heat medium through a mold, a cooler that cools the heat medium is an outer pipe that is a medium pipe through which the heat medium passes , and an inner pipe that is a cooling pipe through which cooling water is passed. A mold temperature control device characterized in that it is constructed in a heavy pipe. In an apparatus for adjusting a mold temperature by circulating a heat medium in a mold, a medium pipe through which the heat medium passes, a medium tank for storing the heat medium on the medium pipe, and heating for heating the heat medium in the casing A cooling device for cooling the heat medium, and a pump for feeding the heat medium to the mold, the cooling device being a cooling pipe through which a part of the medium piping is an outer tube and cooling water passes. A mold temperature control device characterized in that it is configured as a double tube with an inner tube . The mold temperature control apparatus according to claim 1 or 2, wherein propylene glycol or an aqueous solution thereof is used as the heat medium . 3. The casing is provided with an inlet for pressurized air, an air pipe for connecting the inlet to a medium pipe, and a medium outlet for extracting a heat medium urged by the pressurized air from the medium pipe. The mold temperature control apparatus of description.

Images