JP2583395Y2 - Temperature control device for plastic molds - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a temperature control device for a plastic molding die.

(Prior Art) In plastic molding, various resins such as a thermosetting resin and a thermoplastic resin are used. For this reason, in actual molding, the molding die must be set at a suitable molding temperature in accordance with the resin used. For example, in the case of a thermosetting resin, the molding die is set at a considerably high temperature, and in the case of a thermoplastic resin, the temperature is set at a relatively low temperature.

As a method that is generally performed as a method of maintaining a molding die at a predetermined molding temperature, a method of installing an electric heater in the molding die and flowing a heat medium such as water or oil into the molding die. This is a method of maintaining a predetermined temperature.

(Problems to be Solved by the Invention) As described above, in the plastic molding, an electric heater or a heating medium such as water is used to maintain a molding die at a predetermined temperature. There is a point.

That is, in recent years, very precise resin molding has been performed, but in the case of high-density nylon plastic or the like frequently used in such precision processing, molding is performed at a low temperature of 40 to 50 ° C. Therefore, in such a case, when the molding die is heated using the electric heater, the heat of the molten resin is increased due to the large amount of heat of the mold, so that the temperature of the mold rises and the power of the electric heater is not turned off. An overshoot in which the mold temperature rises may occur. When the temperature is lowered by this method, the mold temperature becomes unstable depending on the set temperature because of the natural cooling.

Also, in the case of a method using a heat medium such as water or oil, the temperature rise is slower than direct heating such as an electric heater because a medium having a large heat capacity is used, and the method follows quickly according to the temperature fluctuation. Is difficult. As a result, the temperature fluctuation width of the mold increases. Further, when a heat medium is used, the temperature sensor is usually attached to a main body other than the molding die, and there is a problem that a deviation from the actual die temperature occurs.

Therefore, the present invention has been made to solve the above-mentioned problem, and an object of the present invention is to reduce the temperature of a plastic molding die capable of accurately maintaining a molding die at a predetermined temperature during molding. It is intended to provide an adjusting device.

(Means for Solving the Problems) The present invention has the following configuration in order to achieve the above object.

That is, a temperature controller for a plastic molding die for molding a resin while maintaining the mold temperature at a constant temperature in a temperature range of about 40 to 50 ° C., wherein an electric heating device for heating the die inside the molding die. In addition to providing a heater, a power supply unit for supplying power to the electric heater is provided outside the molding die, and a flow path through which the cooling water flows inside the molding die is provided at an end of the cooling water discharge side. Is provided, a valve for controlling the flow of cooling water is connected to one end of the flow path, a timer for setting the flow time of the cooling water is connected to the valve, and the temperature is set higher than the set temperature of the mold. A supply unit for supplying low-temperature cooling water to the flow path is provided in connection with the valve, a temperature sensor for detecting a mold temperature is provided in the molding die, and the power supply unit is provided based on a detection signal of the temperature sensor. From the power supply to the electric heater and from the supply unit via the timer unit. It is characterized in that a temperature setting device for maintaining the molding die at a predetermined temperature by controlling the flow of cooling water to the molding die is provided.

(Operation) The molding die is heated by an electric heater provided in the molding die, and cooling water is passed through a flow path provided inside the molding die to maintain the molding die at a predetermined set temperature. The temperature setter controls the warming action by energizing the electric heater from the power supply section, and the cooling action by controlling the timer section to open and close the valve and allow the cooling water to flow, thereby forming the molding die. Can be maintained at a predetermined set temperature with high accuracy. In particular, the temperature of the mold is 40 ℃ -50 ℃
In the case of such a low temperature, it is possible to control the temperature of the molding die with high accuracy by utilizing the cooling action of the cooling water.

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

The temperature control device for a plastic molding die according to the present invention utilizes the features of a heating method using an electric heater and a heating / cooling method using a heat medium such as water or oil, and molding is performed by using both of these methods. This is to maintain the mold at a constant temperature with high accuracy.

FIG. 1 is an explanatory view of a configuration example of a temperature control device for a plastic molding die according to the present invention.

In the figure, reference numeral 10 denotes a molding die, which forms an electric heater 12 and a flow path 14 for flowing a heat medium. Also, the molding die
10 is provided with a temperature sensor 16.

The electric heater 12 is connected to a power supply section 18 via a switch section, and the switch section is connected to and controlled by a temperature setting device 20.

One end of the flow path 14 is connected to the valve 20 via a flow path pipe,
The valve 22 is connected to a heat medium supply unit. In the embodiment, water is used as a heat medium. The other end of the flow path 14 is open.

The valve 22 is connected to a timer unit 24, and the opening of the valve is controlled by the timer unit 24.

A detection signal from the temperature sensor 16 is input to a temperature setting unit 20, and the switch unit and the timer unit 24 are controlled based on the detection signal, and the energization of the electric heater 12 and the flow of water by opening and closing the valve 22, respectively, are controlled. .

That is, in this temperature control device, the mold temperature of the molding die 10 is constantly monitored by the temperature sensor 16, and the energization of the electric heater 16 and the flow of water are ON-OFF controlled according to the fluctuation of the molding temperature to form the molding die 10. Is always kept at a constant temperature.

In the case of this apparatus, efficient heating can be performed by direct heating by using the electric heater 12, and cooling can be forcibly performed by flowing water, so that the mold temperature is accurately maintained. It becomes possible. In the case of a molding machine that performs molding at a relatively low temperature, the fluctuation range of the conventional mold temperature is about several degrees Celsius.
The fluctuation range can be suppressed to about ° C. This is due to the combined use of the electric heater and the forced cooling. By maintaining the mold temperature at a predetermined temperature with high accuracy, it is possible to further improve the molding accuracy of the molded product.

This temperature control device is not particularly limited to the set temperature of the molding die, and can set the mold temperature as appropriate, but among others, at a relatively low molding temperature using a high-density nylon plastic or the like. It is suitable for use in products that perform precision molding.

Further, according to the present apparatus, a heater, a cooling device, and a circulating device are not used inside as compared with a conventional device using a heat medium such as water, so that the size of the device can be significantly reduced.

Note that various configurations can be adopted as the specific configuration of the temperature control device.

For example, the heating power of the electric heater can be variably set according to the size of the molding die and the set temperature. In other words, 100% power is supplied for a large molding die, and 30% for a small molding die or a low set temperature.
It is possible to reduce the number of ON-OFF times of the electric heater by suppressing the temperature as low as possible, reduce the overshoot phenomenon, reduce the fluctuation range of the mold temperature, and reduce the power consumption. Also, disconnection of the electric heater or failure of the temperature sensor will cause product failure.
It is possible to add a function to generate an alarm sound when these problems occur or to automatically stop the molding machine.

Conventionally, thermocouples are often used as temperature sensors, but the use of a high-precision temperature sensor such as a platinum temperature sensor with high accuracy even at a low temperature enables more accurate control of the mold temperature.

As described above, the present invention has been described in various ways with reference to preferred embodiments. However, the present invention is not limited to this embodiment, and it is needless to say that many modifications can be made without departing from the spirit of the invention. That is.

(Effects of the Invention) According to the present invention, the configuration as described above makes it possible to accurately maintain the mold temperature of the molding die at the set temperature, and particularly to a comparison of about 40 to 50 ° C. It is possible to control the temperature of a molding die for molding at a very low temperature with high precision. In addition, since the temperature of the mold can be controlled with high accuracy, it is possible to perform highly effective plastic molding.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a configuration example of a temperature controller for a plastic molding die according to the present invention. 10 ... molding die, 12 ... electric heater, 14 ... flow path, 16 ...
... temperature heater, 18 ... power supply unit, 20 ... temperature setting unit, 22 ...
... Valve, 24 ... Timer section.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-57-165223 (JP, A) JP-A-61-279515 (JP, A) Fully open 58-171326 (JP, U) Really open 1980 128107 (JP, U)

Claims (1)

(57) [Scope of request for utility model registration] 1. A temperature control device for a plastic molding die for molding a resin while maintaining a constant mold temperature in a temperature range of about 40 to 50 ° C., wherein the mold is heated inside the molding die. An electric heater for supplying electric power to the electric heater outside the molding die, and a flow path through which the cooling water flows inside the molding die. An end of the flow path is opened, a valve for controlling the flow of cooling water is connected to one end of the flow path, a timer for setting a flow time of the cooling water is connected to the valve, and a mold is set. A supply unit for supplying cooling water at a temperature lower than the temperature to the flow path is provided connected to the valve, and a temperature sensor for detecting a mold temperature is provided in the molding die, and based on a detection signal of the temperature sensor. The power is supplied from the power supply unit to the electric heater, and the electric power is supplied through the timer unit. Temperature regulating device for a plastic molding die, characterized in that a temperature setting device for maintaining the molding die at a predetermined temperature by controlling the flow of cooling water from the parts to the molding die.