JPH0816534B2 - Electric carpet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to an electric carpet.

(Prior Art) In a conventional electric carpet, as shown in FIG. 2, a carpet main body 2 on which a heating element 1 is laid is provided with a temperature detecting means 3 composed of a sensor wire or the like, and an operation (not shown) is performed. The temperature setting voltage Vd detected by the detection means 3 and the temperature setting voltage Vset output from the setting means 4 are compared by the comparison means 5 at any time. Then, the comparison result is provided to the switching control means 6 including a microcomputer (hereinafter abbreviated as a microcomputer) or the like. In the switching control means 6, the heating element 1 is turned on when the temperature detection voltage Vd becomes equal to or higher than the temperature setting voltage Vset, and when the temperature detection voltage Vd becomes equal to or lower than the temperature setting voltage Vset. Is controlled to be turned off so that the temperature of the carpet main body 2 is controlled at a constant temperature close to a preset temperature.

However, in this case, if the temperature setting voltage Vset has a constant value, the heating element 1 is frequently turned on during temperature control.
It will be turned off repeatedly. Therefore, conventionally, the set temperature adjusting means 7 is provided, and when the temperature detection voltage Vd becomes equal to or lower than the temperature setting voltage Vset and the heating element 1 is turned on, the temperature setting voltage Vs is set.
When et is increased to make it difficult for the heating element 1 to turn off, and when the temperature detection voltage Vd becomes equal to or higher than the temperature setting voltage Vset and the heating element 1 is turned off, the temperature setting voltage Vset is lowered to turn on the heating element 1. In this way, the heating element 1 is prevented from being frequently switched on / off.

The electric carpet may be used by covering the carpet body 1 with a carpet cover or by removing the cover. When the cover is not used, heat is more likely to escape than when the cover is used. Therefore, when the cover is not used, the detected temperature rise curve of the temperature detecting means 3 due to the heat generation effect of the heating element 1 becomes gentler than that when the cover is used. In other words, the heating element 1 when the cover is not used
The time from turning on to turning off is longer than when the cover is used. Therefore, if a cushion or the like is placed on the carpet main body 1 without a cover to keep it locally warm, there is a possibility that the local heat becomes abnormally high and an accident such as a burn may occur.

On the other hand, when the cover is not used, the temperature drop curve detected by the temperature detecting means 3 due to the stop of the heating effect of the heating element 1 becomes steeper than that when the cover is used. Therefore, the temperature detection voltage Vd decreases due to the stop of heat generation, and the temperature setting voltage Vset
Even when the heat generating element 1 reaches the temperature and the heating element 1 is turned on, the undershoot amount due to the delay becomes large and the carpet body 1 does not warm up easily, and the carpet body 1 sometimes feels cold.

Therefore, in order to eliminate such a problem, it is necessary to devise, for example, the surface material of the carpet body to be thick so that heat cannot escape easily without the cover.

(Problems to be solved by the invention) As described above, in the conventional electric carpet, in order to eliminate problems such as an accident such as a burn when the cover is not used and a decrease in surface temperature, the surface fabric of the carpet body is thickened, etc. Then, it was necessary to devise so that the heat could not escape easily even without the cover, and the cost was inevitably high.

The present invention has been made based on such circumstances,
Let's provide an electric carpet that can prevent local surface temperature rise and drastic decrease of surface temperature when the cover is not used without requiring special measures to make it difficult for heat to escape and reduce costs. It is what

[Structure of the Invention] (Means for Solving the Problems) The present invention is, as shown in FIG. 1, a carpet body 2 on which a heating element 1 is laid, and a carpet body that is heated by the heat generating action of the heating element 1. A temperature detecting means 3 for detecting the temperature of 2; a temperature setting means 4 for outputting a set temperature; a comparing means 5 for comparing the temperature setting voltage Vset by the setting means 4 with the temperature detection voltage Vd by the detecting means 3; This comparison means 5
A switching control means 6 for switching ON / OFF of the heating element 1 on the basis of the comparison result, and a temperature setting of the setting means 4 according to an ON switching instruction output of the heating element 1 or an OFF switching instruction output by the control means 6. A first set temperature adjusting means 7 for increasing or decreasing the voltage Vset, a time measuring means 8 for measuring a constant time from an ON switching instruction output or an OFF switching instruction output of the heating element 1 by the control means 6, and this timing means 8
And a second set temperature adjusting means 9 for lowering or raising the temperature setting voltage Vset of the setting means 4 in response to the measurement of a certain time.

(Operation) In the electric carpet having such a configuration, when the heating element 1 is turned on in response to the operation switch being turned on, and then the temperature detection voltage Vd of the carpet body 2 reaches the temperature setting voltage Vset, the heating element 1 is turned on. In response to this, the switching control means 6 outputs an OFF switching instruction, and the heating element 1 is turned off. At this time, the temperature setting voltage Vset is once lowered by the first temperature setting control means 7, and after the elapse of a certain time, the temperature setting voltage Vset is raised by the second temperature setting control means 9. Therefore,
Since the heating element 1 is turned on when the carpet body 2 is at a relatively high temperature, the surface temperature drops sharply because the carpet cover is not used, and the surface temperature is sufficient even if the amount of undershoot increases due to the operation delay. Can be maintained.

On the other hand, when the heating element 1 is turned on, the first set temperature control means 7 once raises the temperature set voltage Vset, and after a certain period of time, the second set temperature control means 9 lowers the temperature set voltage Vset. It Therefore, even if the temperature rise is moderate because the carpet cover is not used, the heating element 1 is turned off in a relatively short time, and an abnormally high temperature due to local heat retention is suppressed.

(Example) Hereinafter, one example of the present invention will be described with reference to the drawings.

FIG. 3 is an electric circuit diagram of the electric carpet in this embodiment, and in the drawing, 10 is a microcomputer (hereinafter, abbreviated as a microcomputer) which constitutes the control unit main body. The microcomputer 10 operates on the basis of a preset program by the +5 volt power supply from the control power supply circuit 11, and controls the temperature setting circuit 12, the differential circuit 13, the relay drive circuit 14, and the LED lighting circuit 15, respectively. Also, the temperature signal comparison circuit 16 and the initialization circuit 1
7. A clock generation circuit 18 and a switch input detection circuit 19 are connected to the microcomputer 10, respectively.

Reference numeral 20 in the figure denotes a carpet main body having three modes as a heating surface mode, that is, full surface, left one side, and right one side. A first heater 21 and a second heater 22 are wired to the carpet body 20, and a temperature sensor 23 is wired. First
The second heaters 21 and 22 are for heating one side each, and short-circuit detection lines 24 and 25 are wound around the heaters 21 and 22 via temperature sensitive layers. The heaters 21 and 22 and the temperature sensor 23 are adapted to be supplied with AC power from the control power supply circuit 11. In addition, the temperature sensor 23
Is output to the temperature control circuit 26.

As shown in FIG. 4, the control power supply circuit 11 is configured to supply an AC power supply Vac to the heaters 21, 22 and the temperature sensor 23 via the operation switch SW1 and the temperature fuse TF. There is. The AC power supply Vac is the L
It is also supplied to the ED lighting circuit 15. Further, the control power supply circuit 11 obtains a + 12V (volt) DC power source by the Zener diode ZD1 by half-wave rectifying and smoothing the AC voltage by the diode D10, the resistor R17, and the capacitor C4, and also the transistor Q15 and the resistor R45. And, + 5V DC stabilized power supply is obtained by Zener diode ZD2 and capacitor C8. And + 12V DC power supply is the temperature control circuit 2
6, differential circuit 13 and relay drive circuit 14
The stabilized DC + 5V power supply is supplied to the microcomputer 10, the temperature signal comparison circuit 16, the initialization circuit 17 in addition to the microcomputer 10.
And the switch input circuit 19.

As shown in FIG. 5, the temperature control circuit 26 applies the AC voltage Vac to the resistor R48 and one of the S1 to S2 constituting the temperature sensor 23.
Voltage is divided by the combined resistance of the resistor R52 and the resistor R52 and the resistance between the other E1 and E2 that compose the temperature sensor 23 and the resistor R51 to obtain the temperature detection voltage Vs, and this voltage Vs is connected to the operational amplifier OP.
1, resistor R26, resistor R23, diode D11 and capacitor C7
The voltage Vd corresponding to the temperature detected by the temperature sensor 23 is obtained at both ends of the capacitor C7 by rectifying and smoothing by the peak hold circuit constituted by.

As shown in FIG. 6, the temperature setting circuit 12 divides the half-wave power supply voltage VGB from the short-circuit detection wire 25 wound around the second heater 22 with the resistors R49 and R24 and smoothes it with the capacitor C6. are doing. Further, the half-wave power supply voltage VGA from the short-circuit detection line 24 wound around the first heater 21 is divided by the resistors R50 and R25 to form the transistor Q20 and the transistor Q1.
8 is turned on / off. Here, when the transistor Q20 and the transistor Q18 are on, the resistance R35 and the thermistor T
The voltage divided by the combined resistance of H and the resistor R32 and the combined resistance of the temperature adjustment volume VR, the resistor R18 and the resistor R27 is passed through the maximum temperature control circuit of the transistor Q23, the resistor R30 and the resistor R31 and becomes the set temperature voltage Vset. Become. That is, the set temperature voltage Vset can be changed corresponding to the carpet surface temperature set by the volume VR. In addition, the thermistor TH is used to detect changes in room temperature, and when the room temperature is low, correction is performed to raise the temperature. Furthermore, when switching to single-sided operation, transistor Q19 turns on and transistor Q20 turns off, only transistor Q18 turns on / off, and resistor R28 is added to the above voltage dividing circuit to raise the set temperature voltage Vset, and to operate fully. It is corrected so that the temperature is close to time. Note that the transistor Q6 is turned on by the command from the microcomputer 10 during the tick elimination operation, and the set temperature voltage Vset becomes a high level regardless of the volume VR. Also,
During quick warm-up, transistor Q8 turns on and set temperature voltage
Increase Vset. On the other hand, when the transistors Q20 and Q18 are turned on, the reference voltage is obtained as the sensor secondary foil wire breakage detection voltage Vcut.

In the temperature signal comparison circuit 16, as shown in FIG. 7, the detected temperature voltage Vd from the temperature control circuit 26 is input to the non-inverting input terminal (+), and the set temperature voltage Vset from the temperature setting circuit 12 is input. Has an operational amplifier OP2 input to the inverting input terminal (−). When [Vd <Vset], the output of the operational amplifier OP2 becomes low level and the transistor Q14
Turns off, the temperature detection signal becomes high level constant,
In the case of [Vset <Vd <Vcut], the output of the operational amplifier OP2 repeats the high level and the low level, and the transistor Q1
4 turns on / off, the temperature detection signal repeats high level and low level, and when [Vcut <Vd], the output of the operational amplifier OP2 becomes high level and the transistor Q14 turns on to detect the temperature. The signal is configured to be constant at a low level. Here, the temperature detection signal is input to the microcomputer 10.

As shown in FIG. 8, the differential circuit 13 turns on the transistor Q17 and turns off the transistor Q16 and the transistor Q7 when the differential signal from the microcomputer 10 becomes a high level to set the temperature of the temperature setting circuit 12. When the voltage Vset rises and the differential signal becomes low level, the transistor Q17 is turned off, the transistors Q16 and Q7 are turned on, and the set temperature voltage Vset of the temperature setting circuit 12 is lowered.

As shown in FIG. 9, the relay drive circuit 14 uses a DC power source obtained by half-wave rectifying and smoothing an AC power source by a diode D3, a resistor R4 and a capacitor C1 as a relay coil power source. And the output from the microcomputer 10 is a relay
Transistor Q4 and transistor Q2 for ON signal
Is turned on to turn on the relay RLA and the relay RLB to energize the first and second heaters 21 and 22, and the relay O
Transistor Q4 and transistor Q2 for FF signal
Is turned off to turn off the relay RLA and the relay RLB, and to de-energize the first and second heaters 21 and 22. Here, the switching of the heating surface mode is performed by the switches SW2 and SW3. That is, when the switch SW2 is on, the transistor Q1 is on, the transistor Q2 is off, the relay RLB is off, and only the first heater 21 is operated on one side. On the other hand, when the switch SW1 is on, the transistor Q3 is on, the transistor Q4 is off, the relay RLA is off, and only the second heater 22 is operated on one side.

The initialization circuit 17, as shown in FIG.
It has a system reset IC (integrated circuit) 27 that sets the output O to a low level until the supply voltage Vc to the power supply VDD of the microcomputer 10 reaches the microcomputer operating voltage, and sets the output O to a high level when the microcomputer operating voltage is reached.

As shown in FIG. 11, the clock generation circuit 18 has an oscillator Xi that generates an internal clock of 455 KHz, for example.

As shown in FIG. 12, the switch input circuit detection circuit 19 has a mite extermination switch SW5, an immediate warm switch SW6 and an alarm switch SW7, and when each of the switches SW5 to SW7 is pressed, the microcomputer 10 has a high switch input. A level signal is input.

On the other hand, the LED lighting circuit 15 is, as shown in FIG.
The AC power supply Vac is dropped by the capacitor C3, half-wave rectified by the Zener diode ZD3, and the voltage is limited to be used as the power supply for the LED circuit. Then, when a high level signal is output from the ports corresponding to the LEDs 1 to 4 of the microcomputer 10, the corresponding transistors Q10 to Q13 are turned on to turn on the LEDs 1 to 4.

Further, in this electric carpet, as various safety circuits, an overheat prevention circuit 28 shown in FIG. 13, a relay contact welding detection circuit 29 shown in FIG. 14, a short circuit detection wire breakage detection circuit 30 shown in FIG. 15, The microcomputer failure detection circuit 31 shown in FIG. 16 is incorporated.

Then, the microcomputer 10 receives power supply from the control power supply circuit 11 when the operation switch SW1 is turned on, and initializes when this becomes the microcomputer operating voltage. After the initialization, the heating operation shown in Fig. 17 is started. That is, the temperature detection signal output from the temperature signal comparison circuit 16 is periodically fetched, and ON / OFF of the relay RLA and the relay RLB is controlled according to the detection signal to control the energization of the heaters 2 and 22. . That is, when the temperature detection signal has a constant high level (Vd <Vset), a relay OFF signal is output to the relay control circuit 14. Also,
Even when the temperature detection signal is low level constant (Vd> Vcut),
A relay OFF signal is output to the relay control circuit 14.
On the other hand, when the temperature detection signal alternately changes between high level and low level (Vset <Vd <Vcut), a relay ON signal is output to the relay control circuit 14.

Further, when the output to the relay control circuit 14 is switched from off to on, the microcomputer 10 sets the differential signal to the differential circuit 13 to a high level, and at the same time, starts the time measurement by the built-in timer. Then, when the preset fixed time (for example, 3 minutes) is counted by the built-in timer, the differential signal is returned to the low level.

In the electric carpet having such a configuration, when the operation switch SW1 is turned on, the heating operation is started, and the heaters 21 and 22 are energized according to the states of the surface changeover switches SW2 and SW3. Further, the temperature setting voltage Vset set by the temperature setting circuit 12 and the temperature detection voltage Vd detected by the temperature control circuit 26 are compared at any time by the temperature signal comparison circuit 16, and the temperature detection voltage Vd rises to the temperature setting voltage Vset. If so, the power supply to the heaters 21 and 22 is released. As a result, the temperature detection voltage Vd drops, and when the temperature detection voltage Vd reaches the temperature setting voltage Vset, the relay control output turns off.
The signal is changed to the relay ON signal, and the power supply to the heaters 21 and 22 is restarted. At this time, the differential signal is switched from low level to high level, and the temperature setting voltage Vset of the temperature setting circuit 12 rises in the direction in which the temperature rises, that is, in the direction in which the relay is hard to turn off. At the same time, the timer built into the microcomputer starts. Then, when the timer measures a certain time, the differential signal switches to the low level, and the temperature setting voltage Vset drops.

In this way, the temperature setting voltage once increased so that the relay is hard to turn off when the heater is energized again.
Since Vset is lowered after a lapse of a certain period of time, even if the temperature rise is moderate because the carpet cover is unused, the heater is de-energized in a relatively short time. Therefore, even if a cushion or the like is placed on a carpet main body that has not been used for a carpet cover to keep the temperature locally, an abnormally high temperature due to the locally keeping the temperature is suppressed, and an accident such as a burn is prevented. Therefore, it is not necessary to take measures such as thickening the surface material of the carpet body, and the cost can be reduced.

The present invention is not limited to the above embodiment. For example, in the above-described embodiment, the case where the temperature setting voltage Vset, which has been once increased when the energization to the heater is restarted, is decreased after the elapse of a certain time, is shown. The present invention also includes a device that makes it difficult for the relay to turn on, and raises the set voltage Vset after a certain period of time to restart the energization of the heater at a relatively high temperature. By doing so, for example, the surface temperature can be sufficiently maintained even if the carpet cover is unused, the temperature drop curve is sharp, and the amount of undershoot due to operation delay is large. Therefore, in consideration of the case where the carpet cover is not used, it is not necessary to take measures such as thickening the surface material of the carpet body, and the cost can be reduced.

In addition, it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[Effects of the Invention] As described in detail above, according to the present invention, the local surface temperature rise and the surface temperature increase when the cover is not used, without requiring special measures for making it difficult for heat to escape. It is possible to provide an electric carpet that can prevent a significant decrease and can reduce the cost.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of the present invention, FIG. 2 is a block diagram showing a conventional configuration, FIGS. 3 to 17 are diagrams showing an embodiment of the present invention, and FIG. Overall circuit configuration diagram, FIG. 4 is a circuit diagram of a control power supply circuit, FIG. 5 is a circuit diagram of a temperature control circuit, FIG. 6 is a circuit diagram of a temperature setting circuit, and FIG.
Figure is the circuit diagram of the temperature signal comparison circuit, Figure 8 is the circuit diagram of the differential circuit, Figure 9 is the circuit diagram of the relay drive circuit, Figure 10 is the circuit diagram of the initialization circuit, and Figure 11 is the circuit of the clock generation circuit. FIG. 12, FIG. 12 is a circuit diagram of a switch input detection and LED lighting circuit, FIGS. 13 to 16 are circuit diagrams of various safety circuits, and FIG. 17 is a flow chart showing a heating operation process of the microcomputer according to the present invention. . 10 …… microcomputer (microcomputer), 11 …… control power supply circuit, 12 …… temperature setting circuit, 13 …… differential circuit, 14 …… relay drive circuit, 16 …… temperature signal comparison circuit, 20 …… carpet body , 21,22 …… Heater (heating element), 23 …… Temperature sensor, 26 …… Temperature control circuit.

Claims (1)

[Claims] 1. A carpet body on which a heating element is laid, temperature detecting means for detecting the temperature of the carpet body heated by the heat-generating action of the heating element, temperature setting means for outputting a set temperature, and this setting. Comparing means for comparing the temperature set by the means with the temperature detected by the detecting means, and turning on / off the heating element based on the comparison result by the comparing means.
Switching control means for switching control of off, and first setting temperature adjusting means for raising or lowering the set temperature of the setting means according to an on switching instruction output or an off switching instruction output of the heating element by the control means, A timer for counting a fixed time from an output for switching on or off an output for switching the heating element by the controller, and a set temperature of the setting unit is lowered or lowered in response to the fixed time being counted by the timer. An electric carpet comprising a second set temperature adjusting means for raising the temperature.