JPS6274457A - Thermostatic apparatus - Google Patents

Abstract

PURPOSE:To enable required measurement by uniformizing temp. distribution, by providing a temp. control part controlling the temp. of a heating medium while detecting the same and a rotational speed control part for controlling the rotational speed of a stirrer on the basis of the temp. of the heating medium. CONSTITUTION:When the objective temp. is set on a temp. setting device, said objective value is sent to a temp. controller 12 while a temp. sensor 5 measures the temp. of the heating medium 1 in a tank 2 and the measured value is sent to the temp. controller 12. The temp. controller 12 operates the objective value from the temp. setting device 11 and the measured value from the temp. sensor 5 and operates a thyristor 13 on the basis of the difference signal of both values to perform the ON/OFF control of the supply of a current to a heater 4. At the same time, the temp. of the heating medium 1 measured by the temp. sensor 5 is stored in RAM17 of a microcomputer 19 through an interface 15.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a constant temperature apparatus having a tank containing a heating medium.

[Technical background of the invention and its problems]

Inspection of the curvature characteristics of bimetals is carried out by placing a bimetal test piece in a tank containing oil as a heating medium, and stirring the oil in the tank with a stirrer to make the temperature distribution uniform. The temperature is gradually increased from room temperature to 50°C, 75°C, and 10°C.
This is done by increasing the temperature to 0°C and measuring the amount of displacement of the test piece at each temperature using a reading telescope or camera through an observation window provided in the tank.

Generally, the viscosity of oil used as a heating medium changes greatly depending on temperature. For example, with methylphenyl silicone oil, 450 cSt at 25°C is 100°
At C, it changes to 20cSt. Therefore, when the stirrer is rotated at a constant rotational speed, for example, 1]00 rpm, while the temperature is low, the viscosity is high and air is taken in by the surface waves generated on the curved surface by one rotation, and the air is not attached to the rotating shaft and its tip. The air drawn in by the stirring blades remains trapped and does not disappear, becoming large kite air bubbles and intervening in the oil. Therefore, the displacement of the test piece can be measured by 3 through the observation window.
111 has a problem in that it is a solid wall.

In addition, when the temperature of the ura increases, the viscosity of the bubbles decreases, so the bubbles are defoamed and reduced.

[Purpose of the invention]

The present invention resides in a constant temperature device having a tank in which a heating medium is housed, configured to reduce foaming of the heating medium caused by a stirrer.

[Summary of the invention]

In addition to a tank in which the heating medium is stored and a stirrer that stirs the heating medium contained in this tank, there is also a temperature control unit that detects and controls the temperature of the heating medium, and a temperature control unit that detects and controls the temperature of the heating medium. Based on the above, a rotation speed adjustment section for adjusting the rotation speed of the stirrer is provided, and the rotation speed of the stirrer is changed according to the temperature of the heat medium, thereby reducing foaming of the heat medium. did.

[Embodiments of the invention]

Hereinafter, the present invention will be described based on embodiments with reference to the drawings.

FIG. 1 shows the configuration of a constant temperature apparatus which is an embodiment of the present invention. This constant temperature device has a cubic-shaped tank (2) containing a heating medium (1) such as methylphenyl silicone oil. This tank (2) is provided with an observation window (3) made of a transparent wall on at least one side, and a heater (4) that heats and raises the temperature of the heat medium (1) accommodated in the tank (2). ), a temperature sensor (5) that detects the temperature of this heating medium (1), and a stirrer (6) that stirs the heating medium (1), that is, a motor (7) fixed to the tank (2). Rotating axis (
A stirring blade (9) is attached to the tip of the heating medium (1).
A stirrer is provided to equalize the temperature in the tank (2).

The output of the temperature sensor (5) is sent to a temperature regulator (12) connected to a temperature setting device (11). Further, energization of the heater (4) is controlled by a thyristor (13) connected to the temperature regulator (12).

In addition, the motor (7) of the agitator (6) is connected to the interface (
CP connected to the temperature sensor (5) via 15)
U(Corltroldanrocessjng Unit
) (16), RAM (RandomAccess
Memory) (17), ROM (Road 0n
A microcomputer (18) consisting of
19), an interface (20) to this microcontroller (19)
), the rotational speed regulator (21) is connected via
The rotation speed is adjusted.

Next, the operation of this constant temperature device will be described.

First, when a target predetermined temperature is set in the temperature setting device (11), the Sakura value for that day is sent to the temperature controller (12).

On the other hand, the temperature sensor (5) measures the temperature of the heat medium (1) in the tank (2) and sends the measured value to the temperature controller (12). The temperature regulator (12) calculates the target value from the temperature setting device (11) and the measured value from the temperature sensor (5), and operates the thyristor (+3) based on the difference between them. , to control the ON/OFF energization of the heater (4).

At the same time, the temperature of the heating medium (1) measured by the temperature sensor (5) is sent to the microcomputer (1) via the interface (15).
9) is stored in the RAM (+7). This microcomputer (1
The rotation speed of the stirrer (6,) for each temperature of the heating medium is programmed in the ROM (18) of 9), and the CPU
(16) is.

A signal for controlling the rotation speed of the motor (7) is sent to the rotation speed regulator (21) based on the temperature of the heating medium (]) stored in the RAM (+7) and the above program. Thereby, the stirrer (6) rotates at a predetermined rotational speed depending on the temperature of the heat medium (1).

Therefore, when this constant temperature device is used to measure the displacement of a bimetallic test piece by raising the temperature from room temperature to 100°C using methylphenyl silicone oil as the heating medium (1), conventionally, the stirrer is rotated at a constant rotation speed of 1 l and 100 rpm. As a result, a large amount of bubbles were generated in the low-temperature region with high viscosity, and the bubbles made it impossible to observe the inside of the tank, making it difficult to determine the temperature accurately. In the A position, the second
As shown by the broken line (23) in the figure, the stirrer (6) is rotated at a low speed of 350rpm, which does not generate bubbles and makes the temperature distribution uniform, in the range from room temperature to 60°C, where the viscosity is high. In the range from 60°C to 100°C, where the temperature drops significantly, the rpm can be automatically set to 1100°C, so as shown in the flowchart in Figure 3, the speed is reduced from room temperature to 100°C while suppressing the generation of bubbles. Over the entire range,
It is now possible to measure accurately.

Although one embodiment of the present invention has been described above based on the measurement of the displacement amount of bimetals, the constant temperature device of the present invention can be used for purposes other than measuring the displacement amount of bimetals.

〔Effect of the invention〕

In addition to a tank in which the heating medium is stored and a stirrer that stirs the heating medium contained in this tank, there is also a temperature control unit that detects and controls the temperature of the heating medium, and a temperature control unit that detects and controls the temperature of the heating medium. Based on this, we have provided a rotation speed adjustment section that adjusts the rotation speed of the stirrer as described above, and are configured so that the rotation speed of the stirrer can be arbitrarily changed according to the temperature of the heat medium, so that the temperature can be adjusted without generating bubbles. It is possible to make the distribution uniform and perform the required measurements.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the configuration of a constant temperature device which is an embodiment of the present invention, Fig. 2 is a diagram showing the relationship between temperature and the rotation speed of a stirrer, and Fig. 3 is a diagram showing the relationship between the temperature and the rotation speed of a stirrer. It is a flowchart when measuring a displacement amount.

Claims (1)

[Claims] A tank containing a heating medium whose viscosity depends on temperature, a stirrer that stirs the heating medium contained in the tank to equalize the temperature of the heating medium, and a heating medium stirred by the stirrer. a temperature sensor that detects temperature; a temperature control unit that controls the temperature of the heating medium based on a temperature detection signal indicating the temperature of the heating medium output from the temperature sensor; and a temperature control unit that adjusts the rotation speed of the stirrer. A control signal is sent to the rotation speed adjustment section for adjusting the rotation speed of the stirrer to a rotation speed corresponding to the viscosity of the heating medium based on the temperature detection signal output from the rotation speed adjustment section and the temperature sensor. 1. A constant temperature device comprising: an arithmetic control unit that outputs output;