JPH09254215A - Injection molding die device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rapidly and efficiently control temperature in an injection molding die device. SOLUTION: A molding is obtained by supplying molding resin to a capvity C for the molding which is formed at time reaching a mold clamping state. Semiconductor type heat pump elements 17, 18 are fitted to a die (retainer plates 4, 12) forming the cavity. A temperature sensor is embedded in the die near to the cavity C. Detected temperature date are outputted to a temperature controller performing control of the heat pump elements. Thereby, the temperature controller receives temperature data outputted from the temperature sensor and energization to the semiconductor type heat pump elements is controlled. The semiconductor type heat pump elements perform heat absorption or heat release for the die. Temperature control is enabled by directly heating or cooling the die especially the vicinity of the cavity. Furthermore, temperature of the die is controlled rapidly and surely by using a temperature control means which utilizes fluid such as water and oil for a medium of heat exchange in combination with that.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD OF THE INVENTION The present invention relates to an injection molding die apparatus.

[0002]

2. Description of the Related Art As is well known, an important factor that determines the quality of an injection-molded article is temperature control of an injection-molding die apparatus. Above all, the temperature of the cavity has a great influence on the injection and solidification of the molded product, and thus has a large influence on the quality of the molded product, and therefore various means for temperature control are adopted.

The temperature control of the injection molding die apparatus is mainly performed by providing a temperature adjusting fluid passage in the die and circulating the fluid between the external temperature adjusting apparatus and the inside of the die apparatus via a pipe. Therefore, the temperature is adjusted by the heat exchange action of the fluid. In the case where the pipe is connected to the mold, the pipe replacement work is required every time the mold is replaced, so that the mold replacement work is troublesome.

On the other hand, in Japanese Utility Model Publication No. 4-27633, by forming a connecting portion for a temperature adjusting pipe on the parting line surface of the die, the die can be attached and detached without the need for attaching and detaching the pipe. We are proposing a mold that allows replacement.

Further, in the temperature adjusting means using a fluid as a heat exchange medium, the response to the temperature change of the mold is indirect and the quick response is insufficient. A method of directly heating the surface in advance by using a high-frequency induction heating device has been proposed (Japanese Patent Publication No. S58)
-40504).

[0006]

SUMMARY OF THE INVENTION Among the above prior arts,
Those utilizing the heat exchange action of the fluid are, as described above,
Since the response to the temperature change is indirect, there is a problem that a time lag occurs and accurate temperature control cannot be performed.
Further, when the mold is directly heated by high-frequency induction heating, the response to temperature changes is speeded up, but since it is limited to only heating, there are restrictions on the material of the molded product that can be applied, and There are problems such as complicated operations.

Further, when the cassette type mold is adopted, since the above-mentioned fluid passage is only provided in the base mold, it is insufficient for temperature control around the cavity of the liver and kidney. There's a problem.

[0008]

In order to solve the above problems, in the injection molding die apparatus of the present invention, a semiconductor type heat pump element is adopted as a means for controlling the temperature of the cavity with high accuracy. Specifically, by attaching a semiconductor type heat pump element to each side of the fixed side mold and the movable side mold that form the cavity part and connecting a temperature control device to this, the temperature in the vicinity of the cavity inside the mold is The mold can be heated or cooled directly in response to changes.

Further, in the injection molding die apparatus, temperature control is an important factor in determining the quality of the molded product even in the parts other than the cavity. Therefore, the fluid used in the prior art is used together with the adoption of the semiconductor type heat pump. By adopting a die temperature adjusting means as a heat exchange medium, the efficiency of temperature adjustment of the entire injection molding die device is improved.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is an injection molding die apparatus for producing a molded product by forming a cavity with a fixed side mold and a movable side mold by mold clamping and supplying a molding resin to the cavity. A semiconductor-type heat pump element that adjusts the temperature of the cavity is provided in each mold in which is located.

Preferably, each mold employs the above-mentioned semiconductor type heat pump element as a temperature control means, and also uses a temperature adjusting means using a fluid as a heat exchange medium.

[0012]

EXAMPLE First, the overall structure of the injection molding die apparatus in this example will be described.

1 and 2 show the positional relationship of each element within the range necessary for explaining the present invention, and the illustration of the guide shaft, the support shaft and other members is omitted.

As shown in FIG. 1, in an injection molding die apparatus for realizing the present invention, a cavity C is formed by a fixed die P and a movable die Q in a mold clamped state, and a molding resin is filled in this cavity. A molded product is obtained by supplying.

In the fixed side mold P, the runner stripper plate 2 is in contact with and separable from the front surface of the fixed side mounting plate 1, and the fixed side base plate 3 is also in contact with and separable from the front surface of the runner stripper plate. Abut. Further, a fixed-side template 4 is fixed to the front surface of the fixed-side base plate 3.

A sprue bush 5 into which a nozzle of the main body of the molding machine is inserted is attached to the central portion of the fixed side mounting plate 1 and the runner stripper plate 2. Sprue bush 5
Is fixed to the fixed side mounting plate 1 by a locate ring 6. Sprue 5 at the end of sprue bush 5
The tip of a faces the sub-runner portion 3a formed on the back surface of the fixed-side base plate 3. Subrunner part 3
At one corner of a, runner portions 3b, 4 are provided in a tapered shape across the fixed base plate 3 and the fixed mold plate 4.
The ends of a are opposed to each other, and the sub-runner portion 3a and the cavity C can be communicated with each other in the mold clamping (illustrated) state. At the end of the runner portion 3b, the tip of a runner lock pin 7 provided so as to penetrate the fixed-side mounting plate 1 and the runner stripper plate 2 is located.

In the movable side mold Q, a spacer block 9 is provided on the front surface of the movable side mounting plate 8, a receiving plate 10 is provided on the front surface of this spacer block, and a movable plate is provided on the front surface of the receiving plate 10. The side base plate 11 is further provided with a movable side mold plate 12 on its front surface. A cavity core 13 is provided substantially in the center of the movable side mold plate 12, and in the mold clamped state, the cavity core 13 and the cavity portion formed on the movable side mold plate 12 and the front surface of the fixed side mold plate 4. A cavity C surrounded by can be formed.

A spacer portion 9a is formed in the center of the spacer block 9, and an ejector plate 14 is provided in the spacer portion so as to be able to move forward and backward. Ejector pins 15 are erected on the front surface of the ejector plate 14. The ejector pin 15 has its tip protruding forward through the insertion holes provided in the receiving plate 10, the movable side base plate 11 and the cavity core 13, respectively.

A through hole 8a into which an ejector rod (not shown) can be inserted is provided in the central portion of the movable side mounting plate 8. When the ejector rod enters from this through hole 8a by the cylinder of the injection molding die device main body (not shown) and the ejector plate 14 is advanced, the tip of the ejector pin 15 projects from the tip of the cavity core 13, In the mold open state, the molded product left in the cavity can be pushed down. When the ejector rod retracts, the ejector plate 14 and the ejector pin 15 can return to their original positions by a return spring (not shown).

Temperature sensors (not shown), which are thermocouples, are provided near the positions where the cavities C are to be formed inside the fixed mold plate 4 and the movable mold plate 12, respectively. The output terminal (not shown) of the temperature sensor is connected to a temperature control device (not shown) provided outside the injection molding die apparatus, and can always measure the surface temperature of the cavity C.

Further, semiconductor type heat pump elements 17 and 18 made of Peltier elements are fixed to the side peripheral portions of the mold in which the cavity C is located, that is, the mold plates 4 and 12, respectively. The mounting portions of the semiconductor heat pump elements 17 and 18 are formed in a plate shape, and are fixed to the side portions of the template by screws.

As is well known, the semiconductor type heat pump element is
Direct current is applied to the two separated plates, p-type semiconductor is connected to one plate, n-type semiconductor is connected to the other plate, and the other end of each semiconductor is connected to the output plate. Therefore, depending on the direction of current flow, the output plate performs heat dissipation (heating) or heat absorption (cooling).

In the present embodiment, the temperature control device sets the current direction so as to cause the semiconductor type heat pump element to absorb heat. The semiconductor type heat pump element is energized by the temperature control device described above. That is, when the temperature data output from the temperature sensor to the temperature control device is higher than the preset temperature, the semiconductor-type heat pump element is energized to absorb the heat of the mold and cool the mold, When the mold temperature is lower than this, the energization is stopped to wait for the temperature rise due to the injection resin supplied to the cavity. During this period, the injection molding die device continues to operate, so the die temperature gradually rises and becomes higher than the set temperature. Here, the mold can be cooled by restarting the power supply to the semiconductor heat pump element.

Further, depending on the type of molding resin, it may be required that the mold temperature be higher than the temperature that naturally rises during operation. In such a case, it is possible to heat the mold by radiating heat from the output plate with the current flowing in the opposite direction. It should be noted that the temperature control device may be set so that heat absorption and heat dissipation can be arbitrarily switched according to the temperature of the mold.

As shown in FIG. 1, in the case where the temperature control by the above-mentioned semiconductor type heat pump element is insufficient for temperature control, in addition to this, a fluid such as water or oil used in the prior art is used. Flow paths (mold temperature adjusting means) 3c, 10a, 11a which are heat exchange media are adopted. That is, the fixed-side base plate 3, the receiving plate 10, and the movable-side base plate 11 have fluid channels 3c and 10 respectively.
a and 11a are provided. A fluid pipe is connected to each end of these flow paths (not shown), and a fluid as a heat exchange medium can flow through the mold. The semiconductor-type heat pump element is attached to each mold plate so that the temperature of the cavity can be adjusted mainly. However, since the temperature adjusting means using the fluid is for adjusting the temperature of the entire mold, There is an advantage that the temperatures of the runner and the cavity core can be adjusted sufficiently.

In the above-mentioned embodiment, the semiconductor type heat pump element is fixed to the side portion of the template, but it may be embedded in a portion near the cavity inside the template. By directly heating or cooling the vicinity of the cavity in this manner, thermal efficiency can be improved and immediate effect of temperature control can be expected. Although a thermocouple is used as the temperature sensor, a resistance thermometer or a thermistor thermometer may be used instead.

Further, in the above-mentioned embodiments, all are applied to the injection molding die apparatus of the type in which the die plate is fixed to the base plate, but the cassette die injection molding die in which only the cassette die can be freely exchanged. It is also applicable to a mold device.
In the case of the cassette mold injection molding mold device, there is a gap between the base plate and the cassette mold, so even if the temperature of only the base mold is adjusted, the effect is insufficient for the cassette mold. However, the effect of temperature adjustment tends to be delayed, but if the present invention is applied to directly adjust the temperature of the cassette mold, the above disadvantages will be solved.

[0028]

According to the present invention, since the semiconductor type heat pump element can directly heat or cool the vicinity of the cavity of the mold, the response of the temperature adjustment to the temperature change becomes fast, and the optimum temperature can be obtained. Injection molding can be continued under the conditions.

In addition to the adoption of the semiconductor type heat pump element, if the temperature adjusting means which uses a fluid as a heat exchange medium, which has been conventionally adopted, is adopted, the temperature of the entire die can be easily adjusted and the semiconductor type The load on the heat pump element can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

[Explanation of symbols]

 P Fixed side mold Q Movable side mold C Cavities 3c, 10a, 11a Mold temperature adjusting means 4,12 Mold plate 17,18 Semiconductor type heat pump element

Claims (2)

[Claims] 1. An injection molding die device for forming a molding cavity by clamping a fixed side mold and a movable side mold, and supplying a molding resin to the cavity to obtain a molded product, wherein the cavity is positioned. An injection molding die apparatus, wherein each of the above-mentioned dies is provided with a semiconductor-type heat pump element for adjusting the temperature of the cavity. 2. The injection molding mold apparatus according to claim 1, wherein each of the molds is also used with temperature adjusting means using a fluid as a heat exchange medium.