JPH0827010B2 - Heating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a heating device for an electric carpet or the like.

(Prior Art) FIG. 6 is an electric circuit configuration diagram of an electric carpet described in JP-A-58-138290. In this electric carpet, heating wires 3 and 4 having different heating values are connected in parallel to one end of a power source 1 via a temperature regulator 2 such as a thermostat, and the other end of the power source 1 is switched by the operation of the temperature regulator 2. The switch 5 is connected to switch and connect the heating lines 3 and 4. The heat generation amount of the heat generation lines 3 and 4 is set to be larger in the heat generation line 3. With such a configuration, in the initial stage of energization, the switch 5 is switched and connected to the heating wire 3 having a large amount of heat generation, and the temperature of the electric carpet rises. After that, the operation of the temperature controller 2 causes the switch 5 to move to the heating wire 4. The temperature of the electric carpet is maintained by switching connection.

By the way, in the electric carpet, signal lines for preventing excessive temperature rise are arranged along the heating lines 3 and 4. Therefore, when the two heating lines 3 and 4 are wired on the electric carpet body, two signal lines are wired in addition to these heating lines 3 and 4, and the circuit configuration becomes complicated. To do. However, as the number of heating wires increases, the circuit configuration becomes more complicated.

(Problems to be Solved by the Invention) As described above, in the electric carpet, since the signal line for preventing the overheat is arranged along the heating lines 3 and 4, the circuit configuration increases as the number of wirings of the heating line increases. Becomes complicated.

Therefore, the present invention can select a heating wire with a desired heating value,
Moreover, it is an object of the present invention to provide a heating device in which these heating wires can be used both as the original heating wires and as a signal wire for preventing excessive temperature rise.

[Structure of the Invention] (Means for Solving the Problem) The present invention relates to a first heating wire that is wired in a carpet body, and a carpet that is wound around the first heating wire via a heat-sensitive layer. A second heating wire that is wired to the main unit and has a heating value different from the heating value of the first heating wire, a cutoff element that is connected to the power supply, and an overcurrent larger than a predetermined current value causes heat to be cut off. A heating resistor for preventing an excessive temperature rise that shuts off the element, and a first heating wire is connected to a power source through the breaking element and a second heating wire is switched to a heating resistor, or a second heating wire is connected. A first heating line or a second heating line by comparing the temperature of the carpet main body with a set temperature, and a switching means for connecting the first heating line to the heating resistor and connecting the first heating line to the power source through the breaking element. Power control to the car When the temperature of the main body is lower than or equal to the set temperature, the switching means is switched and controlled to connect the first heating wire to the power source through the cutoff element and the second heating wire to the heating resistor to connect the carpet body. A temperature control circuit for switching and controlling the switching means to connect the second heating line to the power source through the cutoff element and to switch the first heating line to the heating resistor when the temperature of the above becomes higher than the set temperature. It is a warming device that achieves the above-mentioned object.

(Operation) By providing such means, if the temperature of the carpet main body is equal to or lower than the set temperature, the switching means is switched and controlled by the temperature control circuit, and the first heating wire wired to the carpet main body is cut off. And the second heating wire is connected to the heating resistor. At this time, the second heating line functions as a signal line for preventing excessive temperature rise with respect to the first heating line.

That is, when the first heating wire is abnormally heated and the heat-sensitive layer is melted, and the first heating wire and the second heating wire are short-circuited,
An excessive current of a predetermined current value or more flows into the heat generating resistor, which causes the heat generating resistor to generate heat, causing the interrupting element to perform an interrupting operation to interrupt the power supply.

Also, if the temperature of the carpet body exceeds the set temperature,
The switching means controls the switching by the temperature control circuit,
The heating line is connected to the power source through the cutoff element, and the first heating line is switched and connected to the heating resistor. At this time, the first heating line functions as a signal line for preventing excessive temperature rise with respect to the second heating line.

That is, when the second heating wire is abnormally heated and the heat-sensitive layer is melted, and the second heating wire and the first heating wire are short-circuited,
An excessive current of a predetermined current value or more flows into the heat generating resistor, which causes the heat generating resistor to generate heat, causing the interrupting element to perform an interrupting operation to interrupt the power supply.

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

FIG. 1 is an electric circuit configuration diagram of an electric carpet. A main switch 11, a thermal fuse 12, and a circuit protection resistor R ₁ are connected in series to the power plug 10. On the other hand, H ₁ is the first
The first heating line H ₁ generates a relatively large amount of heat and is wired to the carpet body (not shown). Moreover, H ₂ is a second heating cable, the second heating wire H ₂ is the first heating cable at that generates heat value less than the heating value of the first heating cable H ₁ H ₁ Is routed along the carpet body. Specifically, these first and second
As shown in FIG. ₂ , the heating lines H ₁ and H ₂ of FIG. ₂ are obtained by winding the second heating line H ₂ around the core yarn 13 and applying the heat-sensitive layer 14 around the second heating line H ₂ to form the first heating line H ₁ . It is wound and has a vinyl coating 15 and an adhesive layer 16 on the outer periphery.

Relay contacts R _A , R _B , R _C , and R _D that constitute switching means are connected to the first and second heating lines H ₁ and H ₂ , respectively. These relay contacts R _A , R _B , R _C , and R _D have terminals “1” and “2” and a common terminal c, respectively, of which the relay contacts R _A and R _B have terminals “1” and “1”, respectively. 2 "is connected to one ends of the first and second heating wires H ₁ and H ₂ and the first and second heating wires H are connected to the terminals" 1 "and" 2 "of the relay contacts R _C and R _D , respectively. The other ends of ₁ and H ₂ are connected.

Further, the circuit protection resistor R diode D ₁ in _1, the resistor R ₂ via the connected relay coil Ry are further connected to an NPN transistor Q via the resistor R ₃ to the relay coil Ry. R ₄ and R ₅ are resistors. The contact Rys of the relay coil Ry is connected to the thermal fuse 12 and the relay contact R _A.
Connected to the common terminal c.

An overheat protection circuit is connected to the common terminal c of the relay contact R _B , and the overheat protection circuit has the following configuration. The common terminal c of the relay contact R _B is connected heating resistor R _H of overtemperature prevention, the heating resistor R _H
On the other hand, the diodes D ₂ and D ₃ are commonly connected, and the diode D ₂ among them is connected to the circuit protection resistor R ₁ . The heat generating resistance R _H generates heat when an excessive current flows and melts the thermal fuse 12.

On the other hand, 17 is a temperature sensor, and this temperature sensor 17 is arranged in the carpet main body, and the internal resistance changes according to the temperature of the carpet main body. This temperature sensor 17
Partial pressures for detecting the temperature resistor R _6, R _7, R ₈ are connected, the temperature sensing unit 18 are connected via this out dividing resistors R _7, R ₈ in. The temperature detector 18 outputs a temperature detection voltage Vd corresponding to the impedance of the temperature sensor 17 to the temperature control circuit 19. The level of the temperature detection voltage Vd decreases as the temperature increases, as shown in FIG.

The temperature control circuit 19 compares the temperature of the carpet body detected by the temperature sensor 17 with the set temperature to set the temperature of the carpet body at the initial stage of energization of the first heating line H ₁ or the second heating line H ₂ . When the temperature rises above each relay contact R _A ,
It has the function of switching between R _B , R _C , and R _D, and also NPN.
It has a function of controlling the energization of the first or second heating lines H ₁ and H ₂ by turning on / off the type transistor Q. Specifically, it has the following configuration. The temperature comparison unit 20 compares the temperature detection voltage Vd with the set temperature voltage Vset from the temperature setting unit 21, and outputs the switching signal Vc when the temperature detection voltage Vd <the set temperature voltage Vset in the normal use state. It has a function of sending to the unit 22 and turning on / off the NPN transistor Q according to the comparison result of the temperature detection voltage Vd and the set temperature voltage Vset. The output switching control unit 22 receives the switching signal Vc and operates the output switching unit 23 to operate the relay contacts R _A , R _B , R _C , and R _D.
Each of the relay coils Rya, Ryb, Ryc, Ryd is energized and controlled.

The disconnection detection circuit 24 is connected to the common terminal c of the relay contact R _D.
There are connected, the first or second heating wire H _1, the level of voltage Vh to enter through the H ₂ first or second heating cable H ₁ connected to the overtemperature protection circuit by the disconnection detection circuit 24 ，
It is adapted to detect the disconnection of H _2.

Reference numeral 25 denotes a DC power supply unit that supplies a DC voltage to the temperature comparison unit 20, the output switching control unit 22, and the like.

Next, the operation of the electric carpet configured as described above will be described.

When the main switch 11 is turned on, a DC voltage is supplied from the DC power supply unit 25 to the temperature comparison unit 20, the output switching control unit 22 and the like, which causes the output switching control unit 22 to pass through the output switching unit 23 according to the initial switching pattern. Relay coil Rya, Ryb,
For example, Ryc and Ryd are energized. At this time, each relay coil Ry
The a, Ryb, Ryc, and Ryd are first energized by the relay coil Rya by the output switching control unit 22 as shown in FIG. 4, and then the relay coils Ryd, Ryc, and Ryb in this order. As a result, the relay contacts R _A , R _D , R _C , and R _B are switched and connected to the terminal “1” according to the above sequence.

On the other hand, the temperature sensor 17 indicates a resistance value according to the temperature of the electric carpet body, and the temperature detection unit 18 outputs the temperature detection voltage Vd according to the resistance value to the temperature comparison unit 20. The temperature comparing section 20 compares the set temperature voltage Vset and temperature detection voltage Vd, the temperature of the electric carpet body in initial energizing low, through a resistor R ₄ since a temperature detection voltage Vd> set temperature voltage Vset NPN type transistor Q
Turn on. Thus, the relay coil Ry is energized, the relay contact Rys is closed, and the first heating wire H ₁ is energized. As a result, the initial energizing the temperature of the electric carpet body is raised by the first heating cable H _1, as a signal line of the overtemperature protection circuit by a second heating wire H ₂ to the first heating line H ₁ The function is done.

In this state, when the temperature of the electric carpet body rises and the temperature detection voltage Vd becomes smaller than the set temperature voltage Vset, the temperature comparison unit 20 turns off the NPN transistor Q and sends the switching signal Vc to the output switching control unit 22. When this NPN transistor Q is turned off, relay contact R
ys opens and the first heating line H ₁ is de-energized. or,
The output switching control unit 22 follows the stable switching pattern
Through 23, the bias of each relay coil Rya, Ryb, Ryc, Ryd is released. At this time, each of the relay coils Rya, Ryb, Ryc, Ryd is first released by the output switching control unit 22 as shown in FIG. 5, and then the relay coils Ryd, Ryc, Ryd are released.
The bias is released in the order of yb. This allows each relay contact
R _A , R _D , R _C , and R _B are switched and connected to the terminal “2” according to the above sequence. Thus, the second heating line H ₂ is connected to the relay contact Rys.
And the first heating line H ₁ is connected to the overheat prevention circuit. As a result, the electric carpet body is heated by the _second heating wire H ₂ . After that, the main switch
The output switching control unit 22 releases the bias of each relay coil Rya, Ryb, Ryc, Ryd according to the stable switching pattern until 11 is opened. Then, the temperature comparison unit 20 turns on the NPN transistor Q according to the difference between the temperature detection voltage Vd and the set temperature voltage Vset.
The off control is performed to control the energization of the _second heating line H ₂ .

Here, the operation of the overheat prevention circuit will be explained. In the state where each relay contact R _A , R _B , R _C , and R _D is switched and connected to the terminal “1” at the initial stage of energization, the first When the heating wire H ₁ abnormally heats and the heat-sensitive layer 14 melts and the first heating wire H ₁ and the second heating wire H ₂ are short-circuited, an excessive short-circuit current is generated in the positive half cycle of the power supply. fuse
12 to diode D ₂ , heating resistance R _H , relay contact R _B , second
Heating wire of H _2, the first stream to the heating cable H _1, followed by relay contacts
R _C , diode D ₃ , heating resistance R _H to relay contact R _B , second
Flowing through the heat generating line H ₂ and the first heat generating line H _{1 in} the route of the relay contact _RA and the relay contact Rys. In addition, each relay contact R _A ,
When the first heating line H ₁ and the second heating line H ₂ are short-circuited while R _B , R _C , and R _D are switched and connected to the terminal “2”, an excessive short-circuit current causes, for example, a positive half cycle. From thermal fuse 12 to diode D ₂ , heating resistor R _H , relay contact R _B , first heating wire
H ₁ flows to the second heating line H ₂ , then relay contact R _C , diode D ₃ , heating resistor R _H to relay contact R _B , first heating line
Relay contact R _A , relay contact through H ₁ , second heating line H ₂
It flows on the route of Rys. Thus, when the excessive current flows as described above, the heating resistor R _H generates heat and blows the thermal fuse 12.

The operation of the disconnection detection circuit 24 will be described. The second heat generation functioning as a signal line in the state where each relay contact R _A , R _D , R _C , and R _B is switch-connected to the terminal “1”. When the line H ₂ is broken, the voltage Vh input to this second heating line H ₂ is
Becomes zero level. However, the disconnection detection circuit 24 has a voltage Vh
The occurrence of wire breakage is detected by the change to zero level, and the set temperature voltage Vset of the temperature setting unit 21 is forcibly changed to a high setting.
As a result, the temperature comparison unit 20 turns off the NPN transistor Q to cut off the power supply to the _first heating line H ₁ . The above operation is the same when the relay contacts R _A , R _B , R _C , and R _D are switched and connected to the terminal “2”.

As described above, in the above embodiment, if the temperature of the carpet body is equal to or lower than the set temperature, the temperature control circuit 19 controls the switching means to switch the first heating wire H ₁ to the power source via the temperature fuse 12. Second heating line with connecting to
When H ₂ is connected to the heating resistor R _H , and when the temperature of the carpet body exceeds the set temperature, the temperature control circuit 19 controls the switching means to switch the second heating line H ₂ through the temperature fuse 12. Since the first heating line H ₁ is connected to the heating resistor R _{H while} being connected to the power source, for example, the first heating line H ₁ is abnormally heated and the heat-sensitive layer 14 is melted, so that the first heating line H ₁ When the second and the heating cable H ₂ are short-circuited, excessive current heating resistor R flows in _H since the blowing temperature fuse 12 by the heat generation of the heating resistor R _H and the second heating cable H ₂ first The heating wire H ₁ can be made to function as a signal wire for preventing overheating.

Similarly, when the temperature of the carpet body becomes equal to or higher than the set temperature, the first heating line H ₁ can function as a signal line for preventing the overheating temperature of the second heating line H ₂ .

Therefore, when the surface temperature of the carpet body is quickly increased by heating with the _first heating line H ₁ having a large heating value in the initial stage of energization, the second heating line H _{2 is set} to the overheating temperature of the _first heating line H ₁ . It can be made to function as a signal line for prevention, and after that, the second heat generation amount which is smaller than the heat generation amount of the _first heat generation line H ₁ .
When heating the surface temperature of the carpet main body by switching to the heating line H ₂ of No. 1, the first heating line H ₁ can function as a signal line for preventing the overheating temperature of the second heating line H ₂ .

However, the first heating line H ₁ and the second heating line H ₂ can function as the original heating lines and can also serve as signal lines for preventing overheating, and it is necessary to wire signal lines dedicated to preventing overheating. Therefore, the number of wires to be laid on the carpet body can be reduced and the circuit configuration can be simplified.

The present invention is not limited to the above-described embodiment, and may be modified without departing from the spirit of the invention. For example,
The switching of each relay contact R _A , R _B , R _C , and R _D may be a manual interlocking configuration. In this case, the user has to use each relay contact R _A ,
The terminals "1" and "2" of R _B , R _C and R _D can be arbitrarily switched. For example, if the temperature of the carpet body is raised by the first heating line H _1, the second heating line H ₂ As a result, it can act as a signal line of the overheat prevention circuit, and the safety can be reliably ensured. If such manual switching is performed, the carpet main body can be heated with a desired heat generation amount, and rapid heating can be performed.

Furthermore, the switching of each relay contact R _A , R _B , R _C , R _D may be performed after a predetermined time has elapsed using a timer, or by using both the temperature of the carpet body and the timer, either condition You may make it switch when satisfied. or,
The circuit for preventing excessive temperature rise is not limited to the thermal fuse, but relay contacts may be connected to open the relay contacts upon detection of an excessive current to interrupt the power supply to each heating wire.

Further, it is applicable not only to electric carpets but also to electric blankets and the like.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to select heating wires having a desired heating value, and to use these heating wires as the original heating wires and the function as a signal wire for preventing overheating. It is possible to provide a warming device that can be used in common.

[Brief description of drawings]

1 to 5 are views for explaining an embodiment in which the warming device according to the present invention is applied to an electric carpet. FIG. 1 is an electric circuit configuration diagram and FIG. 2 is each heat generation. FIG. 3 is an external view of a line, FIG. 3 is a view showing a change in temperature detection voltage with respect to temperature, FIGS. 4 and 5 are switching timing diagrams of each relay, and FIG. 6 is a configuration diagram of a conventional technique. 12 ... Temperature fuse, 17 ... Temperature sensor, 18 ... Temperature detection section, 19 ... Temperature control circuit, 20 ... Temperature comparison section, 21 ...
Temperature setting unit, 22 ...... output switching controller, 23 ...... output switching unit, 24 ...... disconnection detecting circuit, H ₁ ...... first heating line, H ₂ ......
Second heating line, R _A , R _B , R _C , R _D ... Relay contact, Rya, Ry
b, Ryc, Ryd …… Relay coil, Ry …… Relay coil, Rys
…… Relay contact, Q …… NPN type transistor, R _H …… Heating resistance.

Claims (1)

[Claims] 1. A first heating wire wired to a carpet body, and a first heating wire wound around the first heating wire via a heat-sensitive layer and wired to the carpet body, and the first heating wire. Second heating wire having a heating value different from the heating value, a breaking element connected to a power source, and an overheat prevention circuit for causing a breaking operation of the breaking element by generating an excessive current larger than a predetermined current value. And the first heating wire is connected to the power source through the breaking element and the second heating wire is switched to the heating resistor, or the second heating wire is connected to the breaking element. Switching means for switching the first heating wire to the heating resistor while connecting to the power source through the first heating wire or the second heating wire by comparing the temperature of the carpet body with a preset temperature. Energization control for heating line And when the temperature of the carpet body is equal to or lower than the set temperature, the switching means is controlled to switch the first heating wire to the power source through the cutoff element and the second heating wire is turned on. When the temperature of the carpet body becomes equal to or higher than a preset temperature, the switching means is switched and connected to connect the second heating wire to the power source through the cutoff element and the first power source. A temperature control circuit for switching and connecting a heating wire to the heating resistor.