JP2666550B2 - Liquid temperature controller - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid temperature controller applied to a cooling device for cooling oil and cutting oil supplied to a machine tool.

[Conventional technology]

In machine tools that perform ultra-precision machining such as NC machine tools, strict temperature control is also required for cooling oil, cutting oil, etc. supplied to the machine tools. For this purpose, a heat exchanger has been interposed in the circulation path of the oil supplied to the machine tool, and the oil temperature has been maintained at an appropriate temperature set in advance by a refrigerator or a heater. It is performed via a liquid temperature controller.

On the other hand, as the liquid temperature control method, there are a method of controlling the liquid temperature to a constant temperature irrespective of the ambient temperature, and a method of following control so that the temperature difference from the ambient temperature (room temperature) is constant. It is designed to be used properly according to the usage conditions of the device.

Further, as a temperature controller corresponding to the above-described control system, the following system is conventionally known.

(1) A liquid temperature detected value is compared with a temperature set value as an input signal, and a control signal corresponding to the deviation is given to a liquid cooling device (refrigerator) and a heating device (electric heater) to keep the liquid temperature constant. What you control on the value.

(2) A device which controls the difference between the liquid temperature and the ambient temperature within a certain range by using the detected values of the liquid temperature and the ambient temperature as input signals.

(3) Further, both functions of (1) and (2) described above are provided in the same controller, and the control mode is switched to either constant liquid temperature control or ambient temperature follow-up control as necessary. What to do. (Refer to Japanese Utility Model Application Laid-Open No. 61-172750) The structure of the conventional liquid temperature controller according to the method (3) will be described with reference to FIGS. 4 and 5. FIG. First, in FIG. 4, reference numeral 1 denotes an operation panel of a temperature controller. On the panel surface, an operation switch 2, a liquid thermometer 3, and a control mode changeover switch for switching a control mode to a constant liquid temperature control / ambient temperature follow-up control. 4. Adjustment knobs 5 and 6 for temperature setting corresponding to each control mode described above, various display lamps 7, abnormal alarm buzzer 8 and the like are provided.
On the panel surface, temperature setting scales 9 (representing the liquid temperature) and 10 (representing the temperature difference between the liquid temperature and the ambient temperature) corresponding to each control mode are displayed on the panel surface.

FIG. 5 shows a circuit configuration of the temperature controller. Numerals 11 and 12 denote a control unit (CPU) for controlling the liquid temperature constant and the ambient temperature follow-up control, each of which is constituted by a one-chip microcomputer. , 13 and 14 are variable resistors for setting the temperature with the adjustment knobs 9 and 10 in FIG. 4 as temperature setting elements for the control units 11 and 12, 15 is a power supply, 16 is a liquid temperature sensor, 17 is an ambient temperature sensor, and 18 is A cooling device (refrigerator) for cooling the liquid, and 19 is a heating device (electric heater). In addition, the control operation of such a temperature controller is well known,
Here, the description is omitted.

[Problems to be solved by the invention]

The conventional liquid temperature controllers shown in FIGS. 4 and 5 have the following problems in terms of structure and operation.

(1) Two independent variable resistors 13 and 14 and adjustment knobs 9 and 10 for each variable resistor are provided as temperature setting elements corresponding to the control modes of the constant liquid temperature control and the ambient temperature follow-up control. Therefore, the operation panel 1 on which these components are mounted becomes large. In addition, since two adjustment knobs 9 and 10 are arranged on the same operation panel, when setting the temperature in accordance with the selection of the control mode, the maintenance staff mistakenly looks at the adjustment knobs and sets the temperature with different adjustment knobs. Is easy to make mistakes.

(2) In addition, the control mode described above hardly changes in the middle after being selected at the beginning of the installation of the machine tool, for example. On the other hand, in the conventional configuration, since the control mode changeover switch 4 is mounted on the front of the operation panel 1 which can be easily touched, the changeover switch 4 may be erroneously operated without being noticed.

The present invention has been made in view of the above points, and has as its object to solve the above-mentioned conventional problems and to provide a liquid temperature controller having a small configuration, a small number of parts, and excellent operability. And

[Means for solving the problem]

In order to solve the above-mentioned problems, in the present invention, for each control mode of constant liquid temperature control / ambient temperature follow-up control, a temperature setting element for performing temperature setting for each of the above control modes is integrated into an operation panel. And a temperature control scale corresponding to each control mode are displayed side by side on an operation panel for the adjustment knob, and the control mode changeover switch is operated. It shall be arranged on the back side of the panel.

[Action]

With the above configuration, the temperature can be set in any of the control modes of the constant liquid temperature control and the ambient temperature follow-up control by adjusting the variable resistor as a single temperature setting element. The setting of the temperature can be dealt with by first selecting the changeover switch control mode, and then adjusting the adjustment knob in accordance with the temperature scale of the range corresponding to the selected control mode.

Further, since the control mode changeover switch is disposed on the back side of the operation panel, the hand cannot be easily touched from the front side of the operation panel. Therefore, after operating the changeover switch in which the control mode is selected first, there is no possibility of erroneously operating the switch during use.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings of the embodiment, the same parts corresponding to FIGS. 4 and 5 are denoted by the same reference numerals.

First, in FIGS. 1 and 2, the operation panel 1 is provided with a control knob 20 integrated as a temperature setting element and a variable resistor 21 connected to the control knob 20, and the control knob is provided. On the panel surface facing 20
Temperature scales 9, 10 of the same range as the temperature scales corresponding to the control modes of the constant liquid temperature control and the ambient temperature follow-up control shown in the figure are displayed side by side. The control mode changeover switch 4 is mounted on the back side of the operation panel 1.

In FIG. 3, reference numeral 22 denotes a control unit in which the two control units 11 and 12 in FIG. 5 are integrated into one module, and an input unit thereof has a liquid temperature sensor 16 and an ambient temperature sensor 17.
Is connected and the cooling device 1 is controlled by a control signal output from the output unit.
8, The operation of the heating device 19 is controlled.

Here, if the liquid temperature constant control mode is selected by the control mode changeover switch 4 and the temperature is set by adjusting the adjustment knob 20 to the temperature scale 9, the control unit 22 receives the liquid temperature detection signal taken from the liquid temperature sensor 16 and The temperature is compared with the temperature set value given by the variable resistor 21, and a control signal corresponding to the deviation is output to the cooling device 18 or the heating device 19 to perform feedback control so as to keep the liquid temperature at a constant temperature. On the other hand, the control mode changeover switch 4 is switched to the ambient temperature follow-up control mode,
If you set the temperature by adjusting the control knob 20 to the temperature scale 10,
Based on the comparison between the detection signals taken from the liquid temperature sensor 16 and the ambient temperature sensor 17 and the temperature set value, feedback control is performed so that the temperature difference between the liquid temperature and the ambient temperature falls within a predetermined range width.

〔The invention's effect〕

Since the liquid temperature controller of the present invention is configured as described above, it has the following effects.

The temperature setting elements are integrated into one variable resistor to correspond to each control mode of constant liquid temperature control / ambient temperature follow-up control, so only one knob for temperature setting is required, and each control mode has Compared with the conventional example equipped with an independent temperature setting element, the number of components mounted on the operation panel is smaller,
The size and cost of the temperature controller can be reduced.

Since the temperature control scale corresponding to each control mode is displayed side by side on the operation panel opposite to the adjustment knob, the temperature can be easily set as compared with the conventional configuration.

Since the control mode changeover switch is arranged on the back side of the operation panel, it is possible to avoid an operation error such as erroneously switching the changeover switch after setting the control mode once without easily touching the switch from the front side of the operation panel. .

[Brief description of the drawings]

1 to 3 show an embodiment of the present invention, and FIGS. 4 and 5 show a conventional example. Here, FIG. 1 is a front view of an operation panel of a temperature controller, and FIG. Side view of FIG. 1, FIG.
FIG. 4 is a block diagram of the control circuit, FIG. 4 is a front view of the operation panel, and FIG. 5 is a block diagram of the control circuit. 1: Operation panel, 4: Control mode switch, 16: Liquid temperature sensor, 17: Ambient temperature sensor, 18: Cooling device, 19: Heating device, 2
0: Adjustment knob, 21: Variable resistor, 22: Control unit.

Claims (1)

(57) [Claims] 1. A control mode changeover switch for switching a control mode between a constant liquid temperature control and an ambient temperature follow-up control, wherein a liquid temperature to be controlled and an ambient temperature are compared with set values given as input signals to a temperature setting element. In a liquid temperature controller that outputs a control signal corresponding to the deviation to a liquid cooling or liquid heating device to control the liquid temperature to a constant value or a value following the ambient temperature, the operation panel includes A temperature control element for setting a temperature for each mode is provided with an integrated control knob and a variable resistor connected to the control knob, and a temperature corresponding to each control mode is individually provided on an operation panel for the control knob. A liquid temperature controller, wherein adjustment scales are displayed side by side, and the control mode changeover switch is arranged on a back side of an operation panel.