JPH0325754Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Field of industrial application The present invention relates to a dry cleaner that appropriately supplies petroleum-based solvent stored in a tank to a washing tub using a pump.

(b) Prior Art Petroleum-based solvents have a low flammability temperature of about 42°C, but the heat generated by the pump motor when driving the liquid supply pump can reach that flammability temperature. Therefore, Utility Model Application Publication No. 55-110194 and Utility Model Application No. 59
In the case of Publication No. 174191, a heat exchanger for cooling is provided inside the tank or in the solvent supply path.

(c) Problems to be solved by the invention Therefore, the conventional technology required piping equipment and cooling water supply equipment, and also increased operating costs.

Therefore, the present invention aims to reduce the amount of equipment and the like by suppressing the heat generated from the pump drive motor as much as possible.

(d) Means for solving the problem The solution according to the present invention includes a motor that drives the pump, a temperature sensor that detects the temperature of the solvent,
The configuration includes a comparison section that compares and determines whether the detected temperature exceeds a set temperature, and a rotation speed control means that rotates the motor at a low speed based on the output of the comparison section.

(E) Effect The pump motor is rotated at high speed while the detected temperature is lower than the set temperature. However, when the temperature exceeds the set temperature, the pump motor is controlled by inverter control that changes the frequency or at zero cross. ON−
The pump is rotated at low speed using phase control, including OFF control, to suppress the generation of frictional heat between the pump and the solvent.
For example, the rotational speed is lowered every few minutes while the detected temperature is above the set temperature, until the rotational speed is lowered to a limit flow rate that does not adversely affect the cleaning operation. The set temperature is sufficiently lower than the ignition temperature and higher than the low temperature at which the cleaning effect is reduced.

(f) Example To explain based on the drawings below, in Fig. 3, a tank 1 containing a petroleum solvent and a rotating drum 2 are shown.
The washing tubs 3 equipped with the solvent are connected by piping through a solvent supply path 4 and a discharge path 5, and a pump 6, a check valve 7, and a filter 8 are inserted in this order in the supply path 4. The drain passage 5 has a drain valve 9 and a button trap 1.
0 is inserted. Further, the supply path 4 near the entrance to the washing tub 3 is branched into the tank 1 via a circulation path 12 having a circulation valve 11 .

A temperature sensor 13 such as a thermistor is provided downstream of the pump 6 to detect the temperature of the solvent. In addition, a trap 14 is installed near the entrance to the washing tub 3.
A flow rate sensor 15 such as a semiconductor pressure-sensitive element is provided to detect the flow rate of the solvent flowing therein based on its pressure.

An inverter device is attached to the induction type motor 16 that drives the pump 6 as a rotation speed control means 17, and the rotation speed of the motor 16 is controlled by the rotation speed control means 17.

Such a dry cleaner is shown in Figure 1.
It is controlled by a microcomputer (hereinafter referred to as microcomputer) 18 consisting of a CPU, ROM, RAM, and I/O.
9. Connect the timer 20, input operation signals from the various keys 21, temperature detection signal from the temperature sensor 13, and flow rate detection signal from the flow rate sensor 15, and connect the rotating drum 2, drain valve 9, and circulation. Valve 1
1. Output to the motor 16, rotation speed control means 17, display device 22, and alarm 23. For this purpose, the microcomputer 18 includes a frequency specifying section 24, a stroke control section 25, a set temperature comparison section 26, a frequency comparison section 27,
It constitutes an upper limit temperature comparison section 28 and an abnormality control section 29.

Next, the operation of the circulation washing process will be explained with reference to the flowchart shown in FIG. First, when the start key 21 is operated, the frequency specifying section 24
The frequency of the power supply applied to the rotation speed control means 17
For example, 60% of the commercial power frequency
Specify it to be Hz. Then, the stroke control section 2
5 causes the motor 16 (pump 6) to send the solvent to the supply path 4, opens the circulation valve 11, returns the solvent to the tank 1, and causes the filter 8 to perform precoating. When the pre-coating time is over,
The stroke control unit 25 closes the circulation valve 11 and the drain valve 9, supplies the solvent to the washing tub 3, and controls the liquid supply time (for example, 1 minute or when a detection signal from a liquid level detector (not shown) arrives). When this is completed, the drain valve 9 is opened and the rotating drum 2 is reversed. That is, the solvent is supplied to the rotating drum 2 in a shower-like manner and is circulated back to the tank 1 (circulation washing). The temperature of the solvent flowing in the path is detected by a temperature sensor 13, and the flow rate is detected by a flow rate sensor 15, and each is inputted to a microcomputer 18 as a detection signal.

The set temperature comparison unit 26 of the microcomputer 18 compares the detected temperature with a preset temperature at which cleaning power is ensured and is safe, for example 28°C, and checks if the detected temperature rises beyond the set temperature. ing. Here, when there is an output from the comparison section, the frequency comparison section 27 of the microcomputer 18 determines that the frequency currently specified by the frequency specification section 25 is an infinite frequency (a minimum flow rate (for example, 30) required for the cleaning operation). ),
For example, it is compared and determined whether the frequency has decreased to 30Hz. If the detected temperature has decreased, the upper limit temperature comparator 28 checks whether the detected temperature reaches the upper limit temperature (for example, about 38°C, which is close to flammable or explosive temperature), and if it reaches the upper limit temperature, the abnormality control unit 29 It is displayed and notified, and if necessary, the temperature is lowered using a cooler (not shown) or the like.

As a result of the comparison in the frequency comparison section 27, if the currently specified frequency has not been lowered to the lower limit frequency, the frequency specifying section 24 re-instructs the rotation speed control means 17 to lower the currently specified frequency in units of 5 Hz, for example. . Then, the rotation speed control means 17 lowers the rotation speed of the motor 16 due to the new designation. After that, every 2 minutes, the same temperature comparison as above is carried out during the stroke time.
A frequency comparison task is performed.

In this way, when the solvent temperature exceeds the set temperature,
The rotational speed of the motor 16 is gradually lowered to suppress an increase in solvent temperature due to generated heat.

In this embodiment, an inverter device is used as the rotation speed control means 17, but a switching element such as a triax inserted in the power supply path of the motor 16 can be directly controlled by an ON-OFF signal from the microcomputer 18. The rotation speed of the motor 16 may be changed.

(g) Effects of the invention According to the invention, it is possible to compare the solvent temperature with a set temperature and suppress the increase in solvent temperature due to the heat generated by the motor by lowering the motor rotation speed. It is possible to provide an extremely simple and inexpensive dry cleaner that does not require large cooling equipment or its operation to suppress the temperature of the solvent.

[Brief explanation of the drawing]

FIG. 1 is a control circuit diagram of a dry cleaner according to the present invention, FIG. 2 is a flowchart for explaining the operation, and FIG. 3 is a piping mechanism diagram. 1...Tank, 3...Washing tub, 6...Pump,
13...Temperature sensor, 16...Motor, 17...
...Rotation speed control means, 18...Microcomputer, 24...
Frequency specification section, 26...Set temperature comparison section.

Claims (1)

[Scope of utility model registration request] The petroleum-based solvent stored in the tank is transferred to the washing tub.
In a dry cleaner that is appropriately supplied by a pump, a motor that drives the pump, a temperature sensor that detects the temperature of the solvent, and a comparison section that compares and determines whether the detected temperature exceeds a set temperature;
A dry cleaner comprising: rotation speed control means for rotating the motor at a low speed based on the output of the comparison section.