JP2543910B2 - Operation control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention relates to an operation control device for controlling a plurality of operation steps in sequence or selectively by a microcomputer based on a detected temperature.

(Prior Art) Conventionally, for example, in a dishwasher with a drying function, there is one in which each operation of washing, rinsing, and drying is controlled by a microcomputer. Since the execution time depends on the water temperature,
A voltage divider circuit is formed by connecting a thermistor for temperature detection and a voltage divider resistor in series, and the voltage divided by this voltage divider circuit is applied to the microcomputer to control the operation while judging the temperature. There is something like this.

(Problems to be Solved by the Invention) However, in the above-described conventional configuration, temperature control is performed only for a specific operation stroke of a plurality of operation strokes after a prototype stage or a mass production test after incorporating a microcomputer. If it becomes necessary to change the specifications of the temperature divider, replacing the voltage divider resistor of the voltage divider circuit with another resistor with a different resistance value will change the temperature control specifications even for other operation strokes that do not require specification changes. Will end up. Therefore, in order to avoid this, the software of the microcomputer must be modified, and this includes the RO that stores the software.
Since it was necessary to change the mask of M, it was troublesome to correct and the cost was high.

The present invention is intended to solve such a problem, and therefore an object thereof is to specify temperature control specifications for any one of a plurality of driving strokes and to modify software of a microcomputer. It is an object of the present invention to provide an operation control device that can be easily changed and can reduce the time and cost required for changing the specifications.

[Configuration of the Invention] (Means for Solving the Problems) The operation control device of the present invention includes a voltage dividing circuit having a thermistor for temperature detection and a voltage dividing resistor, and a voltage divided by the voltage dividing circuit. With a microcomputer for sequentially or selectively controlling a plurality of operating strokes while determining the temperature based on the above, the microcomputer is provided with an output port for temperature correction corresponding to the operating stroke, and A correction resistor is provided between the output port and the voltage dividing circuit, and the microcomputer is configured to control so as to switch the output state of the output port according to the execution sequence of the operation stroke.

(Operation) Since the microcomputer changes the output state of the temperature correction output port according to the operation stroke to be executed, the voltage division ratio of the voltage dividing circuit becomes a value corresponding to each stroke. And
The microcomputer controls the operation based on the voltage as the temperature detection signal provided from the voltage dividing circuit. Therefore,
The temperature control specifications (division ratio of the voltage divider circuit) for each operation stroke can be changed independently by simply replacing the correction resistor with another resistor with a different resistance value. No modification of microcomputer software is required.

(Example) Hereinafter, an example in which the present invention is applied to a dishwasher will be described with reference to the drawings. Reference numeral 1 denotes a microcomputer, a ROM 2 in which a control program for each washing, rinsing and drying operation process is stored, a readable / writable RAM 3, an ALU 4 for logical operation, an oscillation circuit 5, and an A / D conversion not shown. And a circuit. And this microcomputer 1
The washing motor 7, the drain motor 8, the water supply valve 9, the heater 10 and the drying fan 11 are controlled to be turned on and off via the output driver 6 based on the output signals from the output ports O _{1 to} O ₅ . Further, to the input ports I ₁ , I ₂ , I ₃ of the microcomputer 1, a course selection switch 12, a drying time setting switch 13, and a start switch 14 also serving as a temporary stop are connected. In this case, the course selection switch 12 is
"Standard course", "Easy course", "Economy course", "Rinse course", "Prewash only course", "Dry only course" are selected in sequence. The operation contents of each course are shown in the time chart of Fig. 2. (A shaded area in FIG. 2 is executed). However, Fig. 2 is a time chart when the water temperature is less than 37 ° C 5 minutes after the start of washing (rinsing).
When the temperature is 50 ° C or higher and 50 ° C or higher, the cleaning time and the rinsing time (rinsing time in "rinsing 4" in Fig. 2) are changed as shown in Tables 1 and 2 on the next page.
Also, the drying time setting switch 13 sets the drying time according to the number of times of pressing, which is “standard / 60 minutes”, “intensive / 120 minutes”, and “about 30 minutes”.
Switch to minutes. On the other hand, in FIG. 1, 15 is a door switch for detecting opening / closing of a door (not shown), and 16 is a washing water A water level detection switch for detecting the water level of (rinse water), 17 is an abnormal water level detection switch for detecting an abnormal water level, and each of these switches 15 to 17 is an input port of the microcomputer 1.
It is connected to I ₄ , I ₅ , and I ₆ . Reference numeral 18 denotes a display unit composed of, for example, an LED, which is dynamically turned on based on output signals from the output ports O ₆ and O ₇ of the microcomputer 1. Reference numeral 19 is a thermistor that detects the temperature of the wash water and rinse water.A voltage divider circuit 21 that is formed by connecting a voltage divider resistor 20 in series to this thermistor 19 is used for the DC power supply terminal V _DS and the ground terminal Vss.
It is provided between and. A common connection point 22 of the thermistor 19 and the voltage dividing resistor 20 in the voltage dividing circuit 21 is connected to an input port I ₇ connected to the A / D conversion circuit of the microcomputer 1 via a signal line 23. Thus, the microcomputer 1 is provided with three output ports Oa, Ob, Oc for temperature correction corresponding to each operation process of washing, rinsing and drying, and these output ports Oa, Ob, Oc Between the common connection point 22 in the voltage dividing circuit 21, the first to third correction resistors 24, 25,
26 are provided in parallel. In this case, each output port O
The output states of a, Ob, and Oc change according to the operation stroke to be executed. Specifically, when executing the washing stroke as shown in Fig. 3, only Oa is set to the Vss level and the others are open. By setting the state, only the first correction resistor 24 is enabled and this is grounded to Vss, and when performing the rinsing stroke, only Ob is set to the Vss level and only the second correction resistor 25 is set to Vss. When performing the drying process in the grounded state, only Oc is set to the Vss level and only the third correction resistor 26 is grounded to Vss.

Next, the operation of the above configuration will be described. When the dishes are stored in the washing tub (not shown) of the dishwasher and the power is turned on, the operation course is automatically set to the "standard course" by default. When the "standard course" is to be executed, the start switch 14 should be turned on immediately to start the operation, but if another driving course is to be executed, the course selection switch 12 should be appropriately turned on. After selecting the driving course, the start switch 14 is turned on to start the driving. Here, for convenience of explanation, assuming that the operation is started in the "standard course", first, the drainage motor 8 is started to drain the remaining water in the washing tank, and then the water supply valve 9 is opened to open the washing tank. After supplying a predetermined amount of water therein, the washing motor 7 is activated to wash the dishes. During execution of this washing step, as shown in FIG. 3, only the first correction resistor 24 is enabled by setting only the output port Oa corresponding to the washing step to the Vss level and leaving the other open. Is grounded to Vss. In this state, the first correction resistor 24 is connected in parallel with the voltage dividing resistor 20 in the voltage dividing circuit 21, and a predetermined voltage dividing ratio according to the connection form is obtained. Then, the resistance value of the thermistor 19 changes according to the water temperature in the washing tank, and the resistance change changes according to the voltage dividing circuit 21.
The voltage Vt at the common connection point 22 changes according to the water temperature in order to change the partial pressure ratio of. This voltage Vt is applied to the input port I ₇ , and the microcomputer 1 determines the temperature of the washing water based on the voltage Vt. As a result, when the water temperature after 5 minutes from the start of washing is judged to be less than 37 ° C, as shown in Table 1, washing is performed for 20 minutes, and if the temperature is between 37 ° C and less than 50 ° C, 18 minutes, 50
Run for 16 minutes above ℃. And after the washing process,
The process proceeds to the rinsing process (the process from rinsing 1 to rinsing 4 in FIG. 2). In this rinsing stroke, only the second correction resistor 25 is enabled and set to Vss by setting only the output port Ob corresponding to the rinsing stroke to the Vss level.
Be grounded to. In this state, the second correction resistor 25 is connected in parallel to the voltage dividing resistor 20 in the voltage dividing circuit 21, and a predetermined voltage dividing ratio according to the connection form is obtained. In this rinsing process, the rinsing time in "rinsing 4" is determined as follows by the water temperature 5 minutes after the start of rinsing. That is, if it is judged that the water temperature is lower than 37 ° C, as shown in Table 2, rinsing is performed for 20 minutes and 37 ° C or higher.
13 minutes below 50 ℃, 6 minutes above 50 ℃. After the completion of the rinsing process, the water is drained and the heater 10 and the drying fan 11 are energized to execute the drying process. In this drying process, only the output port Oc corresponding to the drying process is set to the Vss level to enable only the third correction resistor 26 and set the voltage dividing circuit 21 to a predetermined voltage dividing ratio. Even in this case, the drying time is changed based on the temperature judgment result.

By the way, in the above configuration, when it becomes necessary to change the temperature control specifications for the washing process, for example, at the trial production stage or after the mass production test, the first correction resistor 24 is replaced with another resistor having a different resistance value. Just replace it. In this case, regarding the washing process, the voltage control ratio of the voltage dividing circuit 21 is changed by the replacement of the first correction resistor 24 and the temperature control specifications are changed. However, regarding the rinsing process and the drying process,
The voltage division ratio (specification for temperature control) of the voltage dividing circuit 21 remains unchanged. Similarly, to change only the specifications of the rinsing stroke, the second correction resistor 25 is replaced, and to change only the specifications of the drying stroke, the third correction resistor 26 is replaced. If two of the three correction resistors 24, 25, 26 are replaced,
It is possible to change the specifications of one driving stroke independently of each other. Further, if all the three correction resistors 24, 25, 26 are exchanged, all the specification changes for the three operation strokes can be performed independently of each other.

As described above, in the above embodiment, when it is necessary to change the temperature control specifications for any one of the plurality of driving strokes, the correction resistor corresponding to the changed driving stroke is simply replaced. However, there is no need to modify the software of the microcomputer 1. Therefore, it is not necessary to remake the microcomputer 1 by changing the ROM mask when changing the temperature control specifications, and the time and cost required for changing the specifications can be reduced.

In the above embodiment, the same number of correction resistors 24, 25, 26 as the number of driving strokes are provided. However, for example, the number of correction resistors is one less than the type of driving strokes, and the other one is partial pressure. The voltage dividing resistor 20 of the circuit 21 may also be used as a correction resistor. However, in this case, when the voltage dividing resistor 20 is replaced, all other correction resistors are replaced so as not to affect the specifications of the other operation stroke (the voltage dividing ratio of the voltage dividing circuit 21). There is a need. In addition, output ports for temperature compensation Oa, Ob, Oc
Need not necessarily be provided exclusively for the microcomputer 1, and an existing output port whose output state is changed according to the driving stroke for other control may be used. . In the above embodiment, the first
The third correction resistors 24, 25 and 26 are connected in parallel with the voltage dividing resistor 20.
Connected between 20 and ground terminal Vss
The configuration may be such that 5,26 are connected in series with the voltage dividing resistor 20.

In addition, the present invention is not limited to the dishwasher as in the above-mentioned embodiment, but is widely applied to other electric devices configured to control a plurality of operation steps sequentially or selectively while determining temperature by a microcomputer. Various modifications are possible, such as two or four or more types of driving strokes as long as the number of driving strokes is plural.

[Effects of the Invention] As is apparent from the above description, the present invention provides a correction resistor between the temperature correction output port of the microcomputer and the voltage dividing circuit, and the microcomputer controls the execution order of the operation strokes. The output resistance of the output port is controlled so that the output resistance of the output port can be switched.Therefore, simply by replacing the correction resistor with another one with a different resistance value, the temperature control specifications (dividing circuit The pressure ratio) can be changed independently, and when the temperature control specification is changed, it is not necessary to modify the program of the microcomputer simply by replacing the correction resistor, so it is necessary to change the specification. It has an excellent effect of reducing time and cost.

[Brief description of drawings]

The drawings show an embodiment in which the present invention is applied to a dishwasher. Fig. 1 is a block diagram showing an electrical configuration, Fig. 2 is a time chart showing the contents of each operation course, and Fig. 3 is control. It is a flow chart which shows a program. In the drawing, 1 is a microcomputer, 19 is a thermistor,
20 is a voltage dividing resistor, 21 is a voltage dividing circuit, 24 is a first correction resistor (correction resistor), 25 is a second correction resistor (correction resistor), and 26 is a third correction resistor.
Is a correction resistor (correction resistor).

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Claims (1)

(57) [Claims] 1. A voltage dividing circuit having a temperature detecting thermistor and a voltage dividing resistor, and a plurality of operation steps sequentially or selectively while judging the temperature based on the voltage divided by the voltage dividing circuit. A microcomputer for controlling, wherein the microcomputer is provided with an output port for temperature correction corresponding to the operation stroke, and a correction resistor is provided between the output port and the voltage dividing circuit, The operation control device, wherein the computer controls to switch the output state of the output port according to the execution order of the operation stroke.