JPS58214289A - Sheet heater unit for vehicle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a seat heater device built into a seat of a vehicle such as an automobile, and more particularly to a combination of a seat heater unit, a temperature control circuit section of a control unit, and a safety circuit section.

Seat heaters built into the seats of automobiles and other vehicles are generally required to be comfortable to sit on, to be free from malfunctions such as overheating or burnout, and to provide effective heating and safety.

Figure 1 shows a seat with a built-in seat heater.
A heater unit 3.3' is installed in the back part 2 and the back part 2, respectively.

Figure 2 shows the general configuration of a conventional seat heater.
The seat heater 3 includes an electrically insulating strip-shaped core, a heating wire 4 arranged in a meandering manner on the core, a temperature control device 6 and a high-cut device 5' stacked on the core, and the above-mentioned. The outer fabric 6 and the cord 7 are bonded to both sides of the structure. Said salinity control device 5 and high cut device 5'
is a contact type like a thermostat,
Because it is used with a DC power supply, the contact points are susceptible to damage, so they are quick-acting type, have a large shape, and can be turned on or off.
5 where the offset of F was large As shown in the figure, the large shape restricts the placement position so as not to impair the comfort of the seat. In addition, if a bulky component such as a thermostat is installed in a seat heater that is thin and designed with flexibility in mind, the lead wire may break at the base, so protective measures should be taken. Is required. Furthermore, for some reason, the heating wire may be partially disconnected, etc.
If local overheating occurs, the seat heater and seat may burn out because there are no safety measures.

The present invention takes this consideration into consideration, and uses the heating wire itself as a component of the temperature control circuit section and safety circuit section, so that the control circuit components do not become clumpy, and therefore, the seating comfort is improved. Another object of the present invention is to provide a vehicle seat heater that does not cause disconnection of connections such as cords or mechanical damage to switches.

In order to achieve this object, the present invention constitutes a seat heater unit consisting of a flexible flat core, a heating wire with a temperature detection binding wired to the core, and an outer fabric.
The control unit includes a temperature control circuit section and a safety circuit section for controlling the seat heater unit, and the heating wire with temperature detection binding of the seat heater unit has a positive characteristic temperature coefficient with respect to the heating wire through a low melting point insulating material. The temperature control circuit section is constructed by using the temperature detection line having a positive characteristic temperature coefficient of the heat generating wire with temperature detection as a detection element, and the safety circuit section is as described above.

With this configuration, the temperature control circuit section and the safety circuit section are configured using heat-generating wires with temperature detection binding, and the control unit can be installed separately from the seat heater unit, so the seat heater unit can be configured thinly. Also,
It can also be made contactless, and accidents such as disconnection of the cord connection can be prevented.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In FIG. 3, 8 is a flat core body, and this core body 8
Face V? :, is provided with a heating wire 9 with a temperature detection binding. This heating wire 9 with temperature detection binding is made by winding a temperature detection wire 12 made of nickel or the like whose resistance value changes with temperature changes, with a low melting point insulating material 11 such as nylon interposed around the outer circumference of the heating wire 1°. Furthermore, an insulating jacket 13 is provided on the outer periphery.
has been established. The heat generating wire 9 with a conductivity of 4 is covered with a cover cloth 14 to constitute a seat heater unit.

The temperature control circuit section and the safety circuit section of the control unit are connected as shown in FIG.

If, a temperature fuse 15 and a semiconductor switching element 16 such as a transistor are inserted into the current-carrying circuit of the heating wire 10. The temperature control circuit section divides the reference voltage by a resistor 17, a variable resistor 18, and a resistor 19, and inputs the reference voltage to a non-inverting input V+.
A voltage divided by a resistor 21 and a temperature detection line 12 is applied to the inverting input V- of the comparator 20. The semiconductor switch element 16 is controlled by the operation of the comparator 20. A heating resistor 22 that generates heat due to abnormal current is inserted into the current-carrying circuit of the temperature detection wire 12, and a bias resistor 23 is inserted into the current-carrying circuit 10 so that the voltage at the end of the heating wire 1o becomes high. It is inserted. - In the above configuration, the temperature control circuit section is controlled by temperature detection fa.
12. Comparator 20, semiconductor switch element 16
This is done by That is, the level of the comparator 2o changes depending on the resistance change of the temperature detection line 12. As shown in FIG. 5, when the resistance value of the temperature detection line 12 increases as the temperature rises, the level of the inverting input V- of the comparator 2o rises, and the output level changes from Hl to LO at the set temperature Ts. to be reversed. The output signal of the comparator 20 turns off the semiconductor switch element 16, and the heating wire 10
Turn off the power and lower the temperature. When the temperature decreases, the resistance of the temperature detection wire 12 decreases, and the comparator 20 turns on the semiconductor switch element 16 to energize the heating wire 10 and generate heat.

Next, the operation of the safety circuit section will be explained. When the temperature of the heating wire 10 locally increases, the low melting point insulating material 11 melts, and the heating wire 10 and temperature detection wire 12 are damaged due to dielectric breakdown.
is short-circuited, and a large current flows through the firing resistor 22 in the circuit of the temperature detection line 12.

The temperature fuse 15 is caused by the heat generated by the heating resistor 220.
fuse and cut off the power supply to heating wire 1Q.

Therefore, burnout of the seat heater and the seat due to abnormal heat generation of the heating wire 10 can be prevented.

Here, due to the relationship between the heating wire 10 and the temperature detection wire 12, the dielectric breakdown of the low melting point insulating material 11 is at a high potential a-a.
If it occurs at point 2, a sufficient short circuit current will be generated, but if it occurs at point bb', which has a low potential, the short circuit current will be weak and the heating resistor 220
The temperature fuse 15 is difficult to blow due to heat generation. Therefore, in order to solve this problem, a bias resistor 2 is attached to the heating wire 10.
3 is connected to raise the potential at point b of the heating wire 10 to ensure the minimum operating short-circuit current for blowing out the temperature fuse 16.

In addition, when the temperature detection line 12 is disconnected due to mechanical damage or the like, the inverting input V- of the comparator 20 becomes a high potential, so the semiconductor switch element 16 is turned off by the output signal, and the power supply to the heating line 10 is turned off. Cut off the circuit and ensure safety from this point as well.

As described above, the present invention has the following effects.

1 A heating wire with a temperature detection binding made of a heating wire, a low melting point insulating material, and a temperature detection wire is arranged on a flat core body, and a temperature control circuit section using the heating wire with a temperature detection binding is configured. The heater is thin and does not impair seating comfort, and leads are less prone to breakage.

2. Temperature is detected over the entire surface of the heating wire, and the non-contact control system provides highly accurate temperature control with little offset, and there is no failure due to contact damage. Even if the heating wire is damaged, such as a half-break, and a local temperature rise occurs, the warm fuse blows and the power supply is cut off, thereby preventing meltdown accidents.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a vehicle seat equipped with a seat heater unit, Figure 2 is a perspective view of a conventional heater unit,
FIG. 3 is a perspective view showing the main parts of a heater unit according to an embodiment of the present invention, FIG. 4 is a circuit diagram of a heater unit according to an embodiment of the present invention, and FIG. 5 is a diagram of a comparator in the heater unit. It is a characteristic diagram showing operation. 8...Core body, 9...Heating wire with temperature detection binding, 10...Heating wire, 11...Low melting point insulating material, 12... ...Temperature detection line, 14...
...Outer cloth, 15...Temperature heat, 16...
...Semiconductor switch element, 20...Comparator, 22...Heating resistor, 23...
Bias resistance. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 3 Figure 4

Claims (3)

[Claims] (1) A temperature control circuit that constitutes a seat heater unit consisting of a flexible flat core body, a heat-generating wire with a temperature detection binding wired to the core body, and an outer fabric, and controls the seat heater unit. and a control unit having a safety circuit section, and the heating wire with temperature detection binding of the seat heater unit is formed by running a temperature detection wire having a positive characteristic temperature coefficient along the heating wire through a low melting point insulating material, The temperature control circuit part of the control unit is configured with a temperature detection line having a positive characteristic temperature coefficient of the heating wire with temperature detection binding as a temperature detection element, and the safety circuit part is configured with the heating wire of the heating wire with temperature detection binding and temperature detection. There are also vehicle seat heaters that are configured to be activated by short-circuit current in wires. (2) The temperature control circuit section comprises a comparator operated by a signal generated by a change in the resistance value of the temperature detection line, and a semiconductor switch element controlled on/off by the output of the comparator. The vehicle seat heater device according to item 1. (3) The safety circuit section is equipped with a temperature heater that is activated by a short-circuit current between a heating wire and a temperature detection wire that runs along the heating wire through a low-melting point insulating material, and a bias resistor is connected to the heating wire. 2. The vehicle seat heater device according to claim 1, wherein the lowest potential provides a short circuit current necessary to blow out the temperature fuse.