JP5013113B2 - Sheet electric heater - Google Patents

Description

  The present invention relates to a sheet electric heater such as an electric carpet and a floor heating panel, and more particularly to one that detects the presence of a person on a main body of the sheet electric heater.

  Conventionally, in a sheet electric heater that heats a heating element by heating with a commercial power source such as an electric carpet, the presence of a person on the surface of the main body is detected and the current supply to the heating element is controlled. There is. As such a planar electric heater, an electric heating mat is known in which a heater and a temperature sensing means are vertically separated in the mat (see, for example, Patent Document 1).

  In this electric heating mat, as shown in FIG. 16, the mat-like object 80 is made of a flexible material, and the upper surface is a surface on which a person lies. A heater 81 extending in the direction along the surface of the mat-like object 80 is embedded in the mat-like object 80. The heater 81 is connected to a control device 83 for controlling energization to the heater 81. A temperature sensing means 82 is connected to the control device 83, and the heater 81 is controlled by a signal from the temperature sensing means 82. The temperature sensing means 82 is provided on the back surface of the skin 80 a on the front surface side of the mat-like object 80.

  As a result, the heater 81 and the temperature sensing means 82 constitute an electric heating mat separated vertically in the mat, and the heat storage state of the mat-like object 80 changes depending on the presence or absence of a person on the mat-like object 80. Thus, when the temperature sensing means 82 senses the surface temperature of the mat-like object 80, the presence of a person can be detected and the energization to the heater 81 can be controlled.

  However, the electric heating mat according to Patent Document 1 has a problem that the presence of a person cannot be detected unless the surface of the mat-like object 80 is heated by energization of the heater 81.

  Therefore, as an example of detecting the presence of a person even before the mat surface is warmed, an electric carpet in which a plurality of heaters are provided on an upper portion of a cushioning material such as urethane and a plurality of electrode thin materials is provided on the lower portion is known (for example, (See Patent Document 2).

  In this electric carpet, as shown in FIGS. 17 and 18, a plurality of heaters 100A and 100B are connected to a commercial power supply 300 via energization control means 400A and 400B. The plurality of heaters 100A and 100B are provided on the upper part of the cushioning material 84 of the carpet body, whereas the electrode thin materials 91A and 91B are provided on the lower part of the cushioning material 84. Capacitances Ca and Cb created by the electrode thin materials 91A and 91B and the heaters 100A and 100B are measured by the capacitance measuring means 101. The capacitance measuring means 101 is connected to the determination means 102, and this determination means 102 is connected to the energization control means 400A and 400B.

  In such an electric carpet, for example, when a person is present on the heating area constituted by the heater 100A, the distance between the heater 100A and the electrode thin material 91A approaches and the capacitance Ca increases, This is detected by the capacitance measuring means 101. The determination unit 102 receives this detection result, determines that there is a person, and controls the energization control unit 400A to maintain the energization power amount. When a person is not present on the heating area constituted by the heater 100A (for example, the person leaves the place with meal preparation), the determination unit 102 controls the energization control unit 400A to reduce the energization power amount.

As described above, the capacitance measuring unit 101 detects the capacitances Ca and Cb between the heaters 100A and 100B and the corresponding electrode thin materials 91A and 91B, and the determination unit 102 determines the capacitance. Since the presence of the person is detected from the change, the presence of the person can be detected even if the surface of the carpet body is not warmed. However, in the case of the electric carpet according to Patent Document 2, there is a problem that electrode thin materials 91A and 91B for detecting capacitance are separately required.
Japanese Utility Model Publication No. 61-161894 (pages 5-8, FIG. 1) JP 2000-304294 A (page 5, FIG. 9, FIG. 10)

  In view of the above problems, the present invention has an object to provide a planar electric heater that can detect the presence of a person even when the carpet is not warmed, without using a human detection component such as an electrode thin material. To do.

  In order to solve the above problems, the present invention provides a cushioning material, a heating element disposed on the front side of the cushioning material, and a temperature sensing element disposed on the back side of the cushioning material. A planar electric heater comprising: a main body having a controller; and a controller having a controller that controls energization of the heating element based on temperature detection by the temperature detector. A first detection unit that detects the presence or absence of a person on the main body unit based on the temperature detection, and a capacitance between the heating element and the temperature sensing unit. A second detection unit that detects the presence or absence of a person on the main body by a change, the first detection unit detects the presence or absence of a person during heating operation, and the second detection unit when a heating operation is stopped It is configured to detect the presence or absence of

  According to a second aspect of the present invention, in the first aspect of the present invention, the controller unit is provided with a temperature adjusting unit that energizes the heating element based on a set temperature, and the control unit includes the temperature adjusting unit. Control and selecting and controlling the first detection unit, and when the first detection unit detects absence, the control unit stops energization to the heating element and the second detection When the second detection unit detects human presence, the control unit controls the temperature adjustment unit and also selects and controls the first detection unit. It becomes the composition which becomes.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, a cavity is formed in the cushioning material, and the heating element and the temperature sensing element are opposed to each other at an upper part and a lower part of the cavity part. It is the structure characterized by this.

  According to the first aspect of the present invention, the controller unit detects the temperature based on a change in the current flowing through the temperature sensing body, and detects the presence or absence of a person on the main body unit based on the temperature detection; A second detection unit that detects the presence or absence of a person on the main body by a change in capacitance between the heating element and the temperature sensing element, and detects the presence or absence of a person by the first detection unit during heating operation. When the heating operation is stopped, the presence or absence of a person is detected by the second detection unit. This makes it possible to detect the presence of a person even when the carpet is not warmed, while avoiding human detection parts such as electrode thin materials.

  According to the second aspect of the present invention, the controller unit is provided with the temperature adjustment unit that supplies power to the heating element based on the set temperature, and the control unit controls the temperature adjustment unit and performs the first detection. When the first detection unit detects absence, the control unit stops energization to the heating element, selects the second detection unit, and controls the second detection unit. When the presence of human is detected, the control unit controls the temperature adjustment unit and selects and controls the first detection unit. As a result, even if there are no human detection parts such as thin electrode materials, during heating operation, the presence of a person can be detected by the change in the current flowing through the temperature sensing element under the operation of the temperature control unit. When stopped, the presence or absence of a person can be detected by a change in capacitance between the same temperature sensing element and heating element.

  According to the third aspect of the present invention, the cavity is formed in the cushioning material so that the heating element and the temperature sensing element face each other at the upper part and the lower part of the cavity part. Thereby, when a human load is applied to the main body, the cushioning material is compressed and the heating element comes into contact with the temperature sensing element, so the temperature sensing element can detect the temperature change of the heating element and the presence or absence of a person with higher sensitivity. . In addition, since the cavity forms an air layer and the heat insulation effect between the heating element and the temperature sensing element is increased, there is a difference in the detected temperature of the temperature sensing element between when the heating element and the temperature sensing element are in contact with each other. It becomes larger and can detect the presence of a person with higher sensitivity.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a schematic plan view showing a planar electric heater according to the present invention, FIG. 2 is an exploded perspective view showing a carpet body portion of the planar electric heater according to the first embodiment of the present invention, and FIG. 3 is a carpet of FIG. FIG. 4 is an exploded perspective view showing a carpet body portion of a planar electric heater according to a second embodiment of the present invention, and FIG. 5 is a view of the carpet body portion B of FIG. It is sectional drawing which shows a -B 'cross section.

  6 is an enlarged view of a main part showing a heating element of a planar electric heater according to the present invention, (A) is an enlarged view showing the first embodiment, (B) is an enlarged view showing the second embodiment, FIG. Is an enlarged view of a main part showing a temperature sensing element of a sheet electric heater according to the present invention, FIG. 8 is a cross-sectional view when a person is present on the surface of the carpet body of the sheet electric heater according to the present invention, FIG. FIG. 10 is an exploded perspective view showing a carpet body portion of a sheet electric heater according to a third embodiment of the present invention, and FIG. 10 is a sectional view showing a CC ′ section of the carpet body portion of FIG.

  FIG. 11 is a block diagram for explaining a control circuit mounted on the controller unit of the sheet electric heater according to the present invention, and FIG. 12 illustrates a control circuit mounted on the controller unit of the sheet electric heater according to the present invention. FIG. 13 is a flowchart for explaining the operation of the planar electric heater according to the present invention, (A) is a flowchart for explaining the operation by the control unit, and (B) is a temperature adjusting unit. It is a flowchart explaining the operation | movement by.

  FIG. 14 is a flowchart for explaining the operation of the planar electric heater according to the present invention, (A) is a flowchart for explaining the operation by the first detection unit, and (B) is a flowchart for explaining the operation by the second detection unit. FIG. 15 is a waveform characteristic diagram for explaining the operation of the planar electric heater according to the present invention. FIG. 15A is a waveform characteristic diagram showing the temperature of the heating element of the carpet body and the energization of the heating element. ) Is a waveform characteristic diagram showing the oscillation output time of the oscillation circuit unit according to the change in capacitance between the heating element and the temperature sensing element.

  An embodiment of a planar electric heater according to the present invention will be described using an electric carpet as an example. As shown in FIG. 1, an electric carpet according to the present invention is provided with a carpet main body 1 which is a main body, and a controller unit 2 at the periphery of the carpet main body 1, and a commercial power supply 3 a (not shown) is provided in the controller 2. ) Is connected to the power supply plug 3.

  As shown in FIGS. 2 to 7, the carpet body 1 has a meandering temperature sensor 5 for detecting the temperature of the heating element 8 on a backing fabric 4 made of a material such as polyester felt having good heat insulation. The cushioning material 6 made of a material such as urethane foam having cushioning properties is adhered and fixed on the temperature sensing element 5. Then, a heating element 8 that generates heat by energization is arranged in a meandering manner on the back surface of the face cloth 7 made of tufted cloth, etc., and the front cloth 7 on which the heating element 8 is disposed is bonded and fixed on the cushioning material 6. It is formed by sewing the entire periphery.

  As shown in FIGS. 2 and 3, the temperature sensing element 5 arranged in a meandering manner on the back fabric 4 and the heating element 8 arranged in a meandering manner on the back surface of the front fabric 7 are provided with a cushioning material 6. In parallel with each other with the same arrangement pattern across the surface, a parallel interval is maintained.

  Thus, by holding the temperature sensing element 5 and the heating element 8 facing each other with the cushioning material 6 interposed therebetween, the temperature sensing element 5 can easily detect the temperature of the heating element 8 and the temperature detection accuracy is improved. To do.

  The controller unit 2 includes a control board on which a control circuit for controlling the amount of current supplied to the heating element 8 according to the temperature detected by the temperature sensing element 5 (not shown), a safety protection device, and the like are mounted.

  As shown in FIG. 6A, the heating element 8 is formed by winding a first heating wire 10 made of copper alloy around a core material 9 made of polyester or the like in a spiral shape, and heat-insulating the first heating wire 10 with polyimide or the like. In addition to being covered with the body 11, the second heat generating wire 12 is spirally wound around the heat resistant insulator 11, and the second heat generating wire 12 is covered with an outer insulating layer 13 made of heat resistant PVC or the like. Although not shown, the heating element 8 is connected to the first heating wire 10 and the second heating wire 12 so that currents flow in opposite directions, and the first heating wire 10 and the second heating wire 12 are connected. To cancel out the magnetic field generated from each other and prevent the generation of electromagnetic waves. However, the heating element of the present invention is not limited to this, and as another embodiment, as shown in FIG. 6 (B), the heating element 8 'is made of a heat-resistant insulator 14 such as polyimide that also serves as a core material, and copper. The heating wire 15 made of an alloy may be wound in a spiral shape, and the heating wire 15 may be covered with an outer insulating layer 16 made of heat-resistant PVC or the like.

  As shown in FIG. 7, the temperature sensing element 5 is formed by winding a first detection line 18 made of copper around a core material 17 made of polyester or the like in a spiral manner, and covering the first detection line 18 with a dielectric 19. A second detection line 20 made of copper is spirally wound around the dielectric 19, and the second detection line 20 is covered with an outer insulating layer 21 made of heat-resistant PVC or the like. The dielectric 19 is made of, for example, a plastic thermistor made of a material such as nylon, and the impedance of the plastic thermistor itself changes due to a temperature change, and leaks through the plastic thermistor between the first detection line 18 and the second detection line 20. The current increases or decreases. When the temperature rises, the impedance becomes smaller and the leakage current becomes larger. By detecting the leakage current by the temperature sensing element 5 having such a dielectric 19, the temperature change of the heating element 8 can be detected.

  When a person is present on the surface of the surface fabric 7 of the carpet body 1 having such a configuration, as shown in FIG. 8, the cushioning material 6 is compressed by the load of the person, and the heating element 8 is added to the temperature sensing body 5. Proximity or contact. In the present invention, the presence of a person on the carpet main body 1 to be described later is detected based on the difference between the proximity or contact state between the temperature sensor 5 and the heating element 8 and the non-contact or non-contact state.

  As another embodiment, as shown in FIGS. 4 and 5, the cushioning material 6 is formed with a cavity 6 a having the same pattern as that of the temperature sensing element 5 and the heating element 8. The temperature sensing element 5 is accommodated in the lower part of the cavity part 6a, and the heating element 8 is accommodated in the upper part of the cavity part 6a to maintain a constant interval. As another embodiment, as shown in FIGS. 9 and 10, the temperature sensor 5 disposed in a serpentine shape on the back fabric 4 and the heat generated in a serpentine shape on the back surface of the front fabric 7. The body 8 may be vertically opposed so that the respective arrangement patterns intersect each other with the cushioning material 24 interposed therebetween, and may be held at a constant interval. The cushioning material 24 is formed with a cavity 24a having a mesh pattern so that the arrangement patterns of the temperature sensing element 5 and the heating element 8 intersect each other, and a temperature sensing is formed below the cavity 24a of the cushioning material 24. The heating element 8 is accommodated in the upper part of the cavity 24a and the body 5 is kept at a constant interval.

  Thus, by using the cushioning materials 6 and 24 provided with the hollow portions 6a and 24a shown in FIG. 4 and FIG. 9, the cushioning materials 6 and 24 are compressed when a human load is applied to the carpet body 1. Since the heating element 8 comes into contact with the temperature sensing element 5, the temperature sensing element 5 can detect the temperature change of the heating element 8 and the presence of a person with higher sensitivity. Moreover, since the hollow portions 6a and 24a form an air layer and the heat insulation effect between the heating element 8 and the temperature sensing element 5 is improved, temperature sensing is performed when the heating element 8 and the temperature sensing element 5 are in contact with each other and not in contact with each other. The difference in the detection temperature of the body 5 becomes large, and the presence or absence of a person can be detected with higher sensitivity.

  Next, the operation and human detection of the planar electric heater according to the present invention will be described with reference to FIGS. As shown in FIG. 11, the control circuit includes a temperature adjustment unit 25, a first detection unit 31, a second detection unit 36, and a control unit 45. The temperature adjustment unit 25 includes a temperature detection unit 26, a temperature setting unit 27, an energization control unit 28, A / D conversion units 29 and 30, a temperature storage unit 42, and a temperature comparison unit 43. The first detection unit 31 includes an energization time memory unit 32, an energization time difference calculation unit 33, an energization time detection unit 34, and a determination unit 35. The second detection unit 36 includes an oscillation circuit unit 37, a rise time memory unit 38, a determination time difference calculation unit 39, a determination time detection unit 40, and a determination unit 41.

  In the temperature adjustment unit 25, the impedance of the dielectric 19 changes in the temperature sensing body 5 according to the temperature, and the temperature detection unit 26 detects the change in the leakage current due to the change in the impedance of the dielectric 19. Detect temperature. Analog data from the temperature detection unit 26 is converted into digital data by the A / D conversion unit 29, stored in the temperature storage unit 42 via the control unit 45, and then input to the temperature comparison unit 43.

  The temperature setting unit 27 sets the temperature of the carpet body 1 according to his / her preference, and sets the upper limit temperature Tu for stopping energization of the heating element 8 and the heating element 8. The data of the set lower limit temperature Td for starting the energization of is output. For example, the temperature setting unit 27 determines the set upper limit temperature Tu as 80 ° C. and the set lower limit temperature Td as 60 ° C. according to user settings, and outputs the respective data. Analog data from the temperature setting unit 27 is converted into digital data by the A / D conversion unit 30, stored in the temperature storage unit 42 via the control unit 45, and then input to the temperature comparison unit 43.

  The first detection unit 31 calculates the energization time to the heating element 8 based on the temperature detection of the heating element by the temperature detection unit 26 and detects the change in the energization time, thereby detecting the surface of the carpet body 1. Detect the presence of the person above. The second detection unit 36 detects a change in the oscillation output from the oscillation circuit unit 37 based on the capacitance between the heating element 8 and the temperature sensing unit 5, thereby detecting a person on the surface of the carpet body unit 1. The presence or absence of is detected. The control unit 45 supplies power to the temperature adjustment unit 25, the first detection unit 31, the second detection unit 36, the relay RY1 for energizing the heating element 8 shown in FIG. 12, and the oscillation circuit unit 37. The function of controlling the relay RY2 is provided.

  FIG. 13A is a flowchart for explaining the processing of the control unit 45. The control unit 45 executes “main task”, “temperature adjustment task”, and “person detection (1) task”, which are three task programs that operate in multitasking. These programs can operate simultaneously as independent programs under the supervision of the multitask control program.

  When the power switch of the controller unit 2 of the electric carpet is turned on and the power is turned on, the control unit 45 activates the “main task” by the multitask control program. In the “main task”, the “temperature adjustment task” is activated (ST1), and then the “person detection (1) task” is activated (ST2). Then, it is checked whether the absence flag is ON (ST3). When a “person detection (1) task” described later determines the absence of a person, the person absence flag is set to ON. In the “main task”, the absence of the person is confirmed by the absence flag. If the person absent flag is not ON (ST3: NO), the process returns to ST3. If the person absent flag is ON (ST3: YES), the relay RY1 is turned off (ST4). Then, after executing the subroutine “person detection (2)” (ST5), the process returns to ST1.

  Next, the details of the “temperature adjustment task” in ST1 shown in FIG. 13A will be described using FIG. 13B together with FIGS. When the “temperature adjustment task” is activated, the control unit 45 operates the temperature adjustment unit 25 that energizes the heating element 8. As shown in FIG. 13B, first, it is confirmed whether or not a person absent flag is turned on by a “person detection (1) task” described later (ST6). If the person absent flag is turned on (ST6: YES), the temperature The adjustment task is stopped and the temperature adjustment unit 25 is not operated. On the other hand, if the person absent flag is not ON (ST6: NO), in the temperature adjustment unit 25, the energization control unit 28 closes the relay RY1 for energizing the heating element 8 shown in FIG. The relay RY2 for supplying power to the circuit unit 37 is opened and energization of the heating element 8 is started (ST7). Then, the temperature comparison unit 43 compares the digital data from the temperature detection unit 26 with the digital data of the set upper limit temperature Tu and the set lower limit temperature Td from the temperature setting unit 27, and the temperature of the heating element 8 is set to the set lower limit temperature Td. It is determined whether it is higher or lower (ST8). When the temperature of the heating element 8 is higher than the set lower limit temperature Td (ST8: YES), it is determined whether it is higher or lower than the set upper limit temperature Tu (ST9). When the temperature is higher than the set upper limit temperature Tu (ST9: YES), the energization control unit 28 opens the energization relay RY1 shown in FIG. 12, stops energization of the heating element 8, and de-energizes (ST10).

  On the other hand, when the temperature comparison unit 43 determines that the temperature of the heating element 8 is lower than the set lower limit temperature Td (ST8: NO), the energization control unit 28 continues energization to the heating element 8 and is lower than the set upper limit temperature Tu. Even in this case (ST9: NO), the energization control unit 28 continues to energize the heating element 8, and steps ST8 and ST9 are executed. Next, after de-energizing the heating element 8 in step ST10, the temperature comparison unit 43 determines whether the temperature of the heating element 8 is lower or higher than the set lower limit temperature Td (ST11). When the temperature of the heating element 8 becomes lower than the set lower limit temperature Td (ST11: YES), the process returns to step ST6, and if the absence flag is not ON, the energization control unit 28 closes the energization relay RY1 and generates heat. The body 8 is energized again and the steps after ST7 are executed. When the temperature of the heating element 8 is higher than the set lower limit temperature Td (ST11: NO), the temperature comparison unit 43 continues de-energization to the heating element 8, and returns to step ST11.

  As described above, by the execution of steps ST6 to ST11, in the energization control unit 28 of the temperature adjustment unit 25, as shown in FIG. 15A, the temperature T of the heating element 8 rises to the set lower limit temperature Td at the first rise. In order to continue energization to the heating element 8 until reaching the range, and then repeat energization and de-energization to the heating element 8 so as to be in the range from the set upper limit temperature Tu to the set lower limit temperature Td, as shown in FIG. The energizing relay RY1 is controlled. The heat generated by energization of the heating element 8 is stored in the carpet body 1 and the amount of heat storage gradually increases due to repeated energization and non-energization of the heating element 8, so that the temperature T of the heating element 8 rises. Gradually becomes steep, and the energization time becomes gradually shorter. On the contrary, the fall of the temperature T of the heating element 8 gradually becomes gentle, and the non-energization time becomes gradually longer. Thus, when the heat storage amount of heat generated by the heating element 8 is in a stable state, the ratio between the energization time and the non-energization time becomes substantially constant. Maintained while not present.

  As shown in FIG. 15A, the relationship of the following equation is established in the repetition period of energization and non-energization in which the ratio of the energization time to the heating element 8 and the non-energization time is substantially constant. This repetition period shows a state where the heat storage amount of heat generated by the heating element 8 is stable.

  That is, according to the formula (1), the ratio between the energization time (tH8-tL8) and the non-energization time (tL9-tH8), the ratio between the energization time (tH9-tL9) and the non-energization time (tL10-tH9), the energization time. The ratio between (tH10-tL10) and the non-energization time (tL11-tH10) and the ratio between the energization time (tH11-tL11) and the non-energization time (tL12-tH11) are substantially equal. For example, the temperature adjustment cycle (energization time and non-energization time) for the heating element 8 is about several minutes, and the time required for human detection in the “human detection (1) task” described later is about several milliseconds. When the temperature control and the human detection are performed by multitasking, the relay RY1 for energizing the heating element 8 is not switched before the calculation in the human detection is finished.

  However, as shown in FIG. 8, when a person is present on the surface of the carpet body 1, the amount of heat stored in the carpet body 1 varies each time the person moves on the surface of the carpet body 1. Thus, the stable state of the power supply collapses, and the ratio between the energization time and the non-energization time varies. In the present invention, during heating operation, the presence of a person is detected from the fluctuation in the presence of the person and the stable state in the absence of the person (activation of “person detection (1) task”), Based on the detection result that no person is present, the heating element 8 is de-energized and de-energized to stop the heating operation (stop of the “temperature adjustment task”). Further, when the heating operation is stopped, the presence of a person is detected from the absence of the person (execution of the “person detection (2)” subroutine), and the energization of the heating element 8 is resumed to perform the heating operation. Enter the state (starting the “temperature control task”).

  Next, the details of the “person detection (1) task” in ST2 shown in FIG. 13A will be described using FIG. 14A together with FIGS. 11 and 15A. When the “person detection (1) task” is activated, the control unit 45 selects and controls the first detection unit 31. In the first detection unit 31 illustrated in FIG. 11, the energization time memory unit 32 is energized from the control unit 45 based on the comparison result between the set upper limit temperature Tu and the set lower limit temperature Td by the temperature comparison unit 43 and the temperature of the heating element 8. The energization / non-energization control signals output to the control unit 28 are monitored. The energization time memory unit 32 detects and stores the time tLn that is higher than the set lower limit temperature Td based on the control signal by this monitoring (ST12), and detects the time tHn that is lower than the set upper limit temperature Tu. (ST13).

  The energization time detection unit 34 reads the time tHn that is lower than the set upper limit temperature Tu stored in the energization time memory unit 32 and the time tLn that is higher than the set lower limit temperature Td, and calculates the energization time Δtn by the following equation. (ST14).

  The energization time difference calculating unit 33 calculates the absolute value of the difference between the energization time Δtn−2 calculated by the energization time detection unit 34 and the energization time Δtn calculated by the energization time detection unit 34 (ST15).

  Then, the determination unit 35 compares the absolute value of the difference in energization time input by the control unit 45 and calculated by the energization time difference calculation unit 33 with the determination coefficient Z stored in advance, and the condition of the following equation: The presence / absence of a person is determined based on whether or not is repeated four times in succession (ST16).

  Therefore, in the determination part 35, when the comparison result in which the absolute value of the difference in energization time is smaller than the determination coefficient Z is repeated four times in succession (ST16: YES), if there is no person on the surface of the carpet body part 1, The determination is made and the absence flag is turned on (ST17). Then, the control unit 45 stops the activation of the “person detection (1) task” based on the absence flag ON data from the determination unit 35, and proceeds to step ST4. On the other hand, when the comparison result in which the absolute value of the difference in energization time is smaller than the determination coefficient Z is not repeated four times in succession (ST16: NO), it is determined that there is a person on the surface of the carpet body 1 and ST12 Execute after step.

  As described above, according to the flowchart of “person detection (1) task” that is human detection by the first detection unit 31, for example, the energization time detection unit 34 performs the energization time memory as shown in FIG. The time tH1 that is lower than the set upper limit temperature Tu stored by the unit 32 and the time tL1 that is higher than the set lower limit temperature Td are substituted into the equation (2) to calculate the energization time Δt1, and thereafter Times Δt2, Δt3,... Are calculated. In the embodiment of the present invention, from these energization times Δt1, Δt2, Δt3,..., The energization time difference calculation unit 33 calculates the absolute value of the difference from the previous energization time, and further, the determination unit 35 By substituting the absolute value of the difference between these energization times into the equation (3) and repeating the condition that becomes smaller than the determination coefficient Z four times in succession, it is determined that there is no person. FIG. 15A shows a state in which a condition is established for the absolute value of the difference between the energization times corresponding to the time points of energization times Δt8 to Δt11.

  In this state, a person is no longer present on the surface of the carpet body 1 and the heating element 8 is restored from the temperature sensing element 5 to the cushioning material 6 from the state where the heating element 8 is close to or in contact with the temperature sensing element 5. Therefore, the temperature of the plastic thermistor itself that is the dielectric 19 of the temperature sensing body 5 is lowered, the impedance is increased, and the leakage current that flows between the first detection line 18 and the second detection line 20 is reduced. This is a state in which the decrease in the number appears clearly. As a result, the ratio of the energization time and the non-energization time can be quickly shifted to a stable state where the ratio is substantially constant, and the human detection sensitivity can be improved.

  Here, the control unit 45 stops the activation of the “person detection (1) task” based on the absence flag ON information from the determination unit 35, and as shown in FIG. When the transition is made, the relay RY1 for energizing the heating element 8 is turned off to stop energization to the heating element 8. At the same time, the process proceeds to the execution of the above-described “person detection (2)” subroutine, and the presence or absence of a person on the carpet body 1 is detected by the change in the capacitance between the heating element 8 and the temperature sensing element 5. To do.

  Next, details of the subroutine of “person detection (2)” in ST5 shown in FIG. 13A will be described using FIG. 14B together with FIGS. 11, 12, and 15B. When executing the “person detection (2)” subroutine, the control unit 45 selects and controls the second detection unit 36. The control unit 45 turns on the relay RY2 for supplying power to the oscillation circuit unit 37 of the second detection unit 36 (ST18), and a power supply voltage Vcc (for example, 5 V) is input to the oscillation circuit unit 37. In the second detection unit 36, charging and discharging of a capacitor often used for a timer IC or the like is used as the oscillation circuit unit 37. From the oscillation circuit unit 37, the heating circuit 8 and the temperature sensing unit 5 are connected to each other. A signal having an oscillation frequency corresponding to the capacitance is output from the output terminal OUT to the control unit 45.

  As shown in FIGS. 12 and 15B, the oscillation circuit unit 37 includes an oscillation element 37a, a resistor R1, and a resistor R2, and a heating element 8 and a temperature sensing body between the resistor R2 and the ground. 5 is connected to oscillate and output from the oscillation element 37a based on the capacitance of the capacitor C. First, the operation of the oscillation circuit unit 37 will be described, and thereafter each unit of the second detection unit 36 other than the oscillation circuit unit 37 will be described. In the oscillation circuit unit 37, after the power supply voltage Vcc is turned on, a current flows through the resistor R1 and the resistor R2 through the capacitor C composed of the heating element 8 and the temperature sensing element 5 until the voltage at the point X rises to a predetermined voltage. Electric charges accumulate in the capacitor C. Meanwhile, the oscillation output from the output terminal OUT of the oscillation element 37a is at the H level. When the voltage at the point X reaches a predetermined voltage, the charge accumulated in the capacitor C is discharged. Meanwhile, the oscillation output from the output terminal OUT of the oscillation element 37a is at the L level.

  Further, when the discharge is stopped, current flows again through the capacitor C through the resistors R1 and R2, charges are accumulated in the capacitor C, and the oscillation output from the output terminal OUT of the oscillation element 37a becomes H level. Thereafter, this operation is repeated, and the oscillation output from the output terminal OUT of the oscillation element 37a becomes a rectangular wave that repeats H level and L level. The form of the oscillation circuit of the oscillation circuit unit 37 according to the above description is not limited to this, and any circuit that generates a rectangular wave corresponding to the capacitance of the capacitor C may be used.

  When a person is present on the surface of the carpet body 1, the heating element 8 is close to or in contact with the temperature sensing element 5, and the distance between the heating elements 8 is small, so that the capacitor C composed of the heating element 8 and the temperature sensing element 5 is static. The capacity increases. When no person is present on the surface of the carpet body 1, the heating element 8 is not close to or in contact with the temperature sensing element 5, and the distance between the heating elements 8 is large. Therefore, the capacitor C composed of the heating element 8 and the temperature sensing element 5. The electrostatic capacity of becomes small.

  When the capacitance of the capacitor C is large, the charging (charging) of the capacitor C and the discharging time become long, so that the oscillation output from the output terminal OUT of the oscillation element 37a is H level and L level. Output time becomes longer (oscillation frequency becomes lower). In addition, when the capacitance of the capacitor C is small, charging (charging) and discharging time of the capacitor C are shortened, so that the oscillation output from the output terminal OUT of the oscillation element 37a is H level and L level. Output time is shortened (oscillation frequency is increased). Note that a capacitance also appears between the first detection line 18 and the second detection line 20 of the temperature sensing element 5 shown in FIG. 12, but the capacitance between the heating element 8 and the temperature sensing element 5 Compared to the negligible size.

  As described above, since the oscillation circuit unit 37 operates, the rise time memory unit 38 of the second detection unit 36 outputs an oscillation output from the output terminal OUT of the oscillation element 37a output to the control unit 45. To monitor. The rise time memory unit 38 detects and stores the rise time tum-1 of the oscillation output (ST19), and detects and stores the rise time tum of the next oscillation output (ST20).

  The determination time detection unit 40 reads the rising time tum and the rising time tum-1 of the oscillation output stored in the rising time memory unit 38, and calculates the determination time Δtm by the following equation (ST21).

  The determination time difference calculation unit 39 calculates the difference between the previous determination time Δtm−1 calculated by the determination time detection unit 40 and the determination time Δtm calculated by the determination time detection unit 40 (ST22).

  Then, the determination unit 41 compares the determination time difference input by the control unit 45 and calculated by the determination time difference calculation unit 39 with the determination coefficient F stored in advance, and the condition of the following equation is satisfied. Whether or not there is a person is determined depending on whether or not (ST23).

  Therefore, in the determination part 41, when the comparison result from which the difference of determination time becomes larger than the determination coefficient F is obtained (ST23: YES), it determines with a person existing on the surface of the carpet main-body part 1, and the control part 45 makes a person A judgment signal with presence is output. At the same time, the control unit 45 turns off the relay RY2 for supplying power to the oscillation circuit unit 37 based on the determination signal from the determination unit 41 (ST24). As a result, the control unit 45 shifts to activation of the “temperature adjustment task” in ST1 and to activation of the “person detection (1) task” in ST2. On the other hand, in the determination part 41, when the comparison result in which the difference of determination time becomes smaller than the determination coefficient F is obtained (ST23: NO), it determines with a person not existing on the surface of the carpet main-body part 1, and after the step of ST19 Execute.

  Thus, according to the flowchart of the “person detection (2)” subroutine, which is human detection by the second detection unit 36, as shown in FIG. The determination time Δt21 is calculated by substituting the rising time tu21 and the rising time tu20 of the oscillation output stored in the memory unit 38 into the equation (4), and thereafter the determination times Δt22, Δt23,. Is calculated. From the determination times Δt21, Δt22, Δt23,..., The determination time difference calculation unit 39 calculates a difference from the previous determination time, and the determination unit 41 calculates the difference between these determination times by the equation (5). ) And a condition that is greater than the determination coefficient F is satisfied, it is determined that there is a person. FIG. 15B shows a state in which the condition is satisfied for the value of the determination time difference (Δt24−Δt23).

  In this state, a person is present on the surface of the carpet body 1 and the temperature sensing element 5 is separated from the heating element 8 with the cushioning material 6 interposed therebetween. Since the contact state changes, the capacitance between the heating element 8 and the temperature sensing body 5 is increased, and the output time of the oscillation output H level and L level of the oscillation element 37a is increased. . As a result, the difference between the determination times is clearly shown by the output time of the oscillation output of the oscillation element 37a between the H level and the L level, and human detection is possible.

  In the embodiment described so far, the carpet body 1 has the heating element 8 and the temperature sensor 5 disposed on one side. However, the present invention is not limited to this, and the carpet body 1 is divided into a plurality of heating regions. A heating element and a temperature sensing element may be provided for each heating area. In this case, by providing the temperature adjustment unit 25, the first detection unit 31, and the second detection unit 36 as a plurality of blocks for each heating area, it is possible to detect a person for each heating area.

  In the embodiment described so far, the carpet body 1 includes a temperature sensor 5 disposed in a meandering manner on the back fabric 4, and a buffer material 6 sandwiched between the upper surface of the temperature sensor 5. Although the structure is such that the heating element 8 arranged in a serpentine shape on the back surface of the front fabric 7 is bonded and fixed to the upper surface of the material 6, the present invention is not limited to this, and the carpet body 1 is serpentine on the back fabric 4. The heat-generating body 8 disposed on the top surface of the heat-generating body 8 and the upper surface of the heat-generating body 8 are sandwiched with the buffer material 6, and the upper surface of the buffer material 6 is bonded and fixed to the temperature sensing body 5 disposed in a meandering manner on the back surface of the front fabric 7 It may be structured.

  And in embodiment described so far, in step ST15 of the flowchart of the "human detection (1) task" which is human detection by the 1st detection part 31, the energization of the last time calculated by the energization time detection part 34 is carried out. Although the absolute value of the difference between the time Δtn−2 and the current supply time Δtn calculated by the current supply time detection unit 34 is calculated, the present invention is not limited to this, and for example, the previous current supply time Δtn−1 The absolute value of the difference from the energization time Δtn may be calculated, and can be set as appropriate as long as human detection is possible.

  Furthermore, in step ST16 of the flowchart of “person detection (1) task” which is human detection by the first detection unit 31, the absolute value of the difference (Δtn−2−tn) from the previous energization time is determined from the determination coefficient Z. When a small condition is repeated four times in succession, it is determined that there is no person. However, the present invention is not limited to this, and the condition of Expression (3) is continuously repeated within a range where human detection is possible. The number of times can be set as appropriate. In addition, although the electric carpet was demonstrated to the example, it can apply also to planar electric heaters, such as other electric floor blankets, an electric heating mat, and a floor heating panel.

  According to the planar electric heater of the present invention according to the embodiment described above, the cushioning material 6, the heating element 8 disposed on the front side of the cushioning material 6, and the backside of the cushioning material 6 are disposed. And a controller unit 2 having a controller unit 2 having a control unit 45 for controlling energization of the heating element 8 based on temperature detection by the temperature sensor 5. In addition, the temperature is detected by a change in leakage current flowing between the first detection line 18 and the second detection line 20 of the temperature sensing body 5, and the presence or absence of a person on the carpet body 1 is detected based on this temperature detection. A first detection unit 31 and a second detection unit 36 that detects the presence or absence of a person on the carpet body unit 1 by changing the electrostatic capacitance between the heating element 8 and the temperature sensing unit 5 are provided. One detector 31 detects the presence or absence of a person and The stop has to detect the presence or absence of a person in the second detection unit 36. As a result, the effect of the planar electric heater according to the present invention is to detect the presence of a person regardless of whether the carpet body 1 is warm or not, while avoiding the use of human detection parts such as thin electrode materials. It will be possible.

  Furthermore, according to the planar electric heater of the present invention according to the embodiment described above, the controller unit 2 is provided with the temperature adjusting unit 25 for energizing the heating element 8 based on the set temperature. In addition to controlling the temperature adjustment unit 25, the first detection unit 31 is selected and controlled. When the first detection unit 31 detects absence, the control unit 45 stops energization of the heating element 8. At the same time, when the second detection unit 36 is selected and controlled, and the presence of the person is detected by the second detection unit 36, the control unit 45 controls the temperature adjustment unit 25 and selects the first detection unit 31. To control. Thus, even if there is no human detection component such as a thin electrode material, the presence or absence of a person can be detected by the change in the leakage current flowing through the temperature sensing body 5 under the operation of the temperature adjustment unit 25 during heating operation. When the heating operation is stopped, the presence / absence of a person can be detected by the change in capacitance between the same temperature sensing element 5 and heating element 8.

It is a schematic plan view which shows the planar electric heater by this invention. It is a disassembled perspective view which shows the carpet main-body part of the planar electric heater of 1st Embodiment by this invention. It is sectional drawing which shows the A-A 'cross section of the carpet main-body part of FIG. It is a disassembled perspective view which shows the carpet main-body part of the planar electric heater of 2nd Embodiment by this invention. It is sectional drawing which shows the B-B 'cross section of the carpet main-body part of FIG. It is a principal part enlarged view which shows the heat generating body of the planar electric heater by this invention, (A) is an enlarged view which shows a 2 wire type, (B) is an enlarged view which shows a 1 wire type. It is a principal part enlarged view which shows the temperature sensing body of the planar electric heater by this invention. It is sectional drawing in case a person exists on the surface of the carpet main-body part of the planar electric heater by this invention. It is a disassembled perspective view which shows the carpet main-body part of the planar electric heater of 3rd Embodiment by this invention. It is sectional drawing which shows the C-C 'cross section of the carpet main-body part of FIG. It is a block diagram for demonstrating the control circuit mounted in the controller part of the planar electric heater by this invention. It is a principal part electric circuit diagram for demonstrating the control circuit mounted in the controller part of the planar electric heater by this invention. It is a flowchart for demonstrating operation | movement of the planar electric heater by this invention, (A) is a flowchart explaining operation | movement by a control part, (B) is a flowchart explaining operation | movement by a temperature control part. It is a flowchart for demonstrating operation | movement of the planar electric heater by this invention, (A) is a flowchart explaining the operation | movement by a 1st detection part, (B) is a flowchart explaining the operation | movement by a 2nd detection part. It is a waveform characteristic diagram for demonstrating operation | movement of the planar electric heater by this invention, (A) is a waveform characteristic diagram which shows the temperature of the heat generating body of a carpet main-body part, and electricity supply to a heat generating body, (B) is a heat generating body. FIG. 6 is a waveform characteristic diagram showing an oscillation output time of an oscillation circuit unit according to a change in capacitance between the temperature sensor and the temperature sensing body. It is a schematic block diagram which shows the conventional electrothermal mat. It is sectional drawing which shows the electric carpet by the past. It is a system block diagram which shows the electric carpet by the conventional of FIG.

Explanation of symbols

1 Carpet body (main body)
2 Controller part 3 Plug 3a Commercial power supply 4 Back fabric 5 Temperature sensing element 6 Buffer material 6a Cavity part 7 Front fabric 8 Heating element 8 'Heating element 9 Core material 10 First heating wire 11 Heat-resistant insulator 12 Second heating wire 13 Outside Insulated layer 14 Core material 15 Heating wire 16 Outer insulation layer 17 Core material 18 First detection line 19 Dielectric 20 Second detection line 21 Outer insulation layer 24 Buffer material 24a Cavity portion 25 Temperature adjustment portion 26 Temperature detection portion 27 Temperature setting unit 28 Energization control unit 29 A / D conversion unit 30 A / D conversion unit 31 First detection unit 32 Energization time memory unit 33 Energization time difference calculation unit 34 Energization time detection unit 35 Determination unit 36 Second detection unit 37 Oscillation circuit (Capacitance detector)
37a Oscillating element 38 Rise time memory unit 39 Judgment time difference calculation unit 40 Judgment time detection unit 41 Judgment unit 42 Temperature storage unit 43 Temperature comparison unit 45 Control unit RY1 Relay RY2 Relay R1 Resistance R2 Resistance C Capacitor

Claims (3)

  A main body having a cushioning material, a heating element disposed on the front side of the cushioning material, a temperature sensing element disposed on the back side of the cushioning material, and the heat generation based on temperature detection by the temperature sensing element. In a planar electric heater comprising a controller having a controller for controlling energization to the body, the controller detects a temperature based on a change in current flowing through the temperature sensing body, and based on the temperature detection, the A first detection unit for detecting the presence or absence of a person on the main body, and a second detection unit for detecting the presence or absence of a person on the main body by a change in capacitance between the heating element and the temperature sensing body; The planar electric heater is characterized by detecting the presence or absence of a person with the first detection unit during heating operation and detecting the presence or absence of a person with the second detection unit when heating operation is stopped.   The controller unit is provided with a temperature adjusting unit for energizing the heating element based on a set temperature, and the control unit controls the temperature adjusting unit and selects and controls the first detecting unit, When the first detection unit detects absence, the control unit stops energization of the heating element, selects and controls the second detection unit, and the second detection unit 2. The planar electric heater according to claim 1, wherein the control unit controls the temperature adjustment unit and selects the first detection unit when the temperature is detected.   The planar electric heater according to claim 1, wherein a hollow portion is formed in the cushioning material, and the heating element and the temperature sensing body face each other at an upper portion and a lower portion of the hollow portion.