JP2021111495A - Heater unit and applied article thereof - Google Patents

Abstract

To provide: a heater unit which has a sufficient safety function and can also contribute to power saving or space saving; and a vehicular windshield device equipped with the heater unit.SOLUTION: The heater unit comprises: a foil-like conductor; a planar base material on which the conductor is disposed; and a temperature control device which controls the power supply to the conductor. The conductor is made of a piece of conductor foil, and includes a wide lead part 3 and a narrow heater part 5. The heater part 5 has a main heater part 10 and an auxiliary heater part 13. The temperature control device is operated via heating by the auxiliary heater part 13. The vehicular windshield device, to which the heater unit is fitted, comprises: the heater unit; a bracket fitted to a vehicular windshield; a sensor unit housed in the bracket; and a shading hood housed in the bracket.SELECTED DRAWING: Figure 3

Description

The present invention provides, for example, a heater unit for removing dew condensation, ice, frost, and water droplets adhering to a camera unit, windshield, radar unit, etc. in a vehicle, and preventing fogging, dew condensation, ice, and frost adhering. , With respect to a windshield device equipped with this heater unit.

The vehicle windshield device is attached to the passenger compartment side of the windshield and is used to detect the presence or absence of other vehicles or obstacles in front of the vehicle. The vehicle windshield device includes a bracket fixed to the windshield, a camera unit or radar unit supported by the bracket, and a light-shielding hood that suppresses external light such as sunlight from entering the camera unit. Here, when the humidity inside the vehicle is high or the temperature outside the vehicle is low, cloudiness, dew condensation, frost, ice, etc. adhere to the windshield, so that the vehicle windshield device heats the light-shielding hood. The heater unit is provided on the back side of the light-shielding hood. Due to the heat generated from this heater unit, cloudiness, dew condensation, frost, ice, etc. adhering to the windshield facing the light-shielding hood are melted, evaporated, and removed. As a result, the shooting by the camera unit becomes clear. Further, accurate detection is possible without the radar from the radar unit being attenuated (see Patent Documents 1 and 2 and the like).

Japanese Patent No. 6583651 Japanese Patent No. 6589726

Here, particularly in the electrical components of automobiles, a safety function against an unexpected short circuit or overtemperature due to an overcurrent is required. This is no exception to the heater unit in the windshield device for vehicles. For example, in Patent Documents 1 and 2 above, a fuse is arranged, and when the temperature is excessively increased, the power supply to the heater unit is cut off. It has a structure to do. On the other hand, in recent years, the number of electrical components in automobiles has increased significantly, and some electric vehicles and hybrid vehicles use electricity as power, so power saving in individual parts is extremely high. This is an important issue. Furthermore, in a vehicle windshield device, if the device itself becomes large, it obstructs the driver's field of vision, so there is a demand for miniaturization as much as possible, and various parts such as a camera unit and a radar unit are arranged there. Therefore, the heater unit is also required to be designed to save space.

The present invention has been made to solve such problems of the prior art, and an object of the present invention is to provide a heater unit which has a sufficient safety function and can contribute to power saving and space saving. , To provide a vehicle windshield device equipped with it.

In order to achieve the above object, the heater unit according to the present invention is composed of a foil-shaped conductor, a planar base material on which the conductor is arranged, and a temperature control device for controlling energization of the conductor. The conductor is made of a single piece of conductor foil, and is composed of a wide lead portion and a narrow heater portion, and the heater portion has a main heater portion and an auxiliary heater portion. The temperature control device is operated by heating the auxiliary heater unit.
Further, it is considered that the main heater portion is composed of at least the first heater portion and the second heater portion, and the auxiliary heater portion is located between the first heater portion and the second heater portion. ..
Further, it is conceivable that the temperature control device is connected in series with both the main heater unit and the auxiliary heater unit.
The vehicle windshield device according to the present invention includes the above heater unit, a bracket attached to the vehicle windshield, a sensor unit housed in the bracket, and a light-shielding hood housed in the bracket. The heater unit is attached to the bracket, the sensor unit, or the light-shielding hood.

According to the present invention, since the energization of the conductor is controlled by the temperature control device, the energization can be reliably cut off due to excessive temperature rise to ensure safety, and the energization and cutoff can be switched at a predetermined temperature. The total power consumption can be reduced. Further, since the temperature control device is simulated by the auxiliary heater unit, the temperature control device can be installed in a free place different from the main heater unit. That is, since the temperature control device can be designed at a position that does not interfere with the arrangement of other parts, it is possible to contribute to space saving.

It is a top view which shows the structure of the heater unit by embodiment of this invention. It is sectional drawing which shows the main part of the heater unit according to the Embodiment of this invention in an enlarged manner schematically. It is a top view which shows the structure of a part of the heater unit by embodiment of this invention. It is a circuit diagram of the heater unit according to the embodiment of this invention. It is a graph which shows the temperature measurement data by embodiment of this invention. It is sectional drawing which shows the outline of the windshield device for a vehicle by this invention. It is a circuit diagram which shows the other embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, as shown in FIGS. 1 to 3, there is a base material 7 made of a polyamide-imide film having a thickness of 28 μm. The base material used in the present invention is a film made of a conventionally known polymer material such as a synthetic resin. For example, in addition to a polyamide-imide film, a PET film (polyester film), a polyimide film, a polyphenylene sulfide film and the like can be used. It is preferably used.

A conductor 1 having a thickness of 30 μm obtained by etching a stainless steel (SUS304) foil is formed on the base material 7. As the conductor 1, in addition to stainless steel, for example, metals such as copper, aluminum, and nickel-chromium are preferably used. Further, a conductive resin or the like may be used. These are patterned by, for example, etching processing, punching processing, etc., and are obtained as a single foil-like material. Further, a conductor pattern may be formed by a method such as thin film deposition or coating. The shaded portion shown in FIG. 3 is the conductor 1. The conductor 1 is composed of a lead portion 3 which has a low resistance value due to its wide width and substantially does not generate heat, and a heater portion 5 which has a high resistance value due to its narrow width and contributes to heat generation. Become. The heater unit 5 has a main heater unit 10 and an auxiliary heater unit 13. Further, in the present embodiment, the main heater unit 10 is composed of the first heater unit 11 and the second heater unit 12, and the auxiliary heater unit 13 is located between the first heater unit 11 and the second heater unit 12. It is configured to be located. The resistance values of the first heater unit 11 and the second heater unit 12 are set to 17.9Ω each so as to be (13.6V-3.72W). Further, the resistance value of the auxiliary heater unit 13 is set to 6.4Ω so as to be (13.6V-0.66W).

Further, as shown in FIG. 2, the base material 7 may be formed with an adhesive layer 9 for adhering to another member. In the present embodiment, the surface of the base material 7 on which the conductor 1 is formed becomes a surface in contact with the heated portion, and an adhesive layer 15 made of an adhesive tape is formed on this surface. Further, in order to increase the efficiency of heat conduction to the heated portion, it is conceivable to install a heat insulating sheet 21 made of foamed resin or the like on the surface opposite to the surface in contact with the heated portion. In this case, it is also possible to use a heat insulating sheet 21 in which a plurality of materials having different characteristics such as heat insulating properties, heat resistance, shock absorption, and appearance are combined. In the present embodiment, the base material 7 and the heat insulating sheet 21 are attached by an adhesive layer 16 made of an adhesive tape.

The conductor 1 and the base material 7 obtained as described above have a pattern shape as shown in FIG. Here, two ends of the lead portion 3 of the conductor 1 are exposed, one end is connected to the lead wire 25, and the other end is another lead wire via a thermostat 23 as a temperature control device. It will be connected to 26. The temperature control device also includes a temperature sensitive element such as a thermistor and a protection circuit such as a thermal fuse. The connection between the lead portion 3 and the lead wire 25, the connection portion between the lead portion 3 and the thermostat 23, and the connection between the thermostat 23 and the lead wire 26 are covered with a heat shrinkable tube 27 for the purpose of waterproofing and mechanical protection. Can be considered. Further, the thermostat 23 will be installed at a position where the auxiliary heater portion 13 exists. In this way, the heater unit 31 as shown in FIG. 1 is obtained.

Regarding the heater unit 31 having such a configuration, the circuit configuration and the operation of the temperature control device will be described with reference to the circuit diagram shown in FIG. As shown in FIG. 4, the thermostat 23, which is a temperature control device, is connected from the power supply VCS, and the first heater unit 11, the auxiliary heater unit 13, and the second heater unit 12 are connected in series and dropped to the ground GND. .. Further, the amount of heat generated by the auxiliary heater unit 13, the degree of cooling, and the operating temperature of the thermostat 23 are set so that the first heater unit 11 and the second heater unit 12 generate heat at an appropriate temperature. Therefore, the auxiliary heater 13 heats the thermostat 23 to control the temperatures of the first heater unit 11 and the second heater unit 12 in a pseudo manner. As a result, when the temperatures of the first heater unit 11 and the second heater unit 12 reach predetermined values, the thermostat 23 is turned off and the energization of the entire heater unit 31 is cut off. Further, the temperature of the entire heater unit 31 drops due to the interruption of the energization, but when the temperature of the thermostat 23 drops to a predetermined value, the thermostat 23 is turned on again and the energization is restarted. By repeating this process, the temperature of the heater unit 31 is maintained within a predetermined range.

Such a heater unit 31 can be mounted in a vehicle windshield device. An example of a vehicle windshield device will be described with reference to FIG. The right side in FIG. 6 is the front of the vehicle, and the vehicle windshield device attached to the windshield 57 includes a bracket 51, a light-shielding hood 53, and a camera unit 55 as a sensor unit. The bracket 51 is a bowl-shaped resin member that houses the light-shielding hood 53 and the camera unit 55. An adhesive is formed on the peripheral edge of the bracket 51 and is attached to the passenger compartment side of the windshield 57. The windshield 57 is generally referred to as a windshield, a side glass, or a rear glass. The camera unit 55 is fixedly held by the resin member formed in the bracket. At this time, the light receiving portion of the camera unit 55 is directed toward the windshield 57, and no other member is interposed between the light receiving portion of the camera unit 55 and the windshield 57. The light-shielding hood 53 is a plate-shaped black resin member, and defines the range of light received by the light receiving portion of the camera unit 55. Further, the surface of the light-shielding hood 53 is made to scatter light by being pasted with a non-woven fabric, pear-finished, textured, cut-off, etc., and external light from outside the light receiving range is scattered. Is prevented from being incident. Although not shown, the present embodiment corresponds to a compound eye system including two camera units 55. A first heater unit is installed on the side of one camera unit, and a second heater unit is installed on the side of the other camera unit, and an auxiliary heater unit and a thermostat are arranged between these two camera units. The camera unit 55 may be a radar unit.

When the humidity in the vehicle interior is high or the temperature outside the vehicle is low, cloudiness, dew condensation, frost, ice, and the like may adhere to the windshield 57. Light is scattered by the cloudiness, dew condensation, frost, ice, and the like, which may hinder clear shooting by the camera unit 55. This also applies when a radar unit is used instead of the camera unit. Therefore, the heater unit 31 is attached to the back side of the light-shielding hood 53, and the windshield 57 is heated through the light-shielding hood 53 by the heat generated from the main heater portion 10 of the heater unit 31, causing cloudiness, dew condensation, frost, and ice. Will be removed. Further, the heat from the heater unit 31 heats the air in the bracket 51, which lowers the humidity in the bracket 51, so that dew condensation is removed.

The heater unit 31 installed in the windshield device as described above was actually energized and the temperature was measured. The central portion (A) of the first heater portion, the central portion (B) of the second heater portion, the central portion (C) of the sub-heater, the upper part (D) of the light-shielding hood 53, and the inner surface (E) of the windshield 57. A thermocouple was attached at the measurement points, and energization was performed at an applied voltage of 13.5 V under the condition of an initial atmosphere temperature of 22.9 ° C., and changes in temperature at each measurement points (A) to (E) with time were measured. A graph showing the result of temperature measurement is shown in FIG. As shown in FIG. 5, it was confirmed that the heater unit 31 according to the present embodiment is stably heated.

The present invention is not limited to the above embodiment. In the above embodiment, the main heater unit 10 is composed of the first heater unit 11 and the second heater unit 12, but it may be composed of only the first heater unit, and further, the third heater unit and the fourth heater unit. It may be added to the heater section.

Further, in the above embodiment, the first heater unit 11, the auxiliary heater unit 13, the second heater unit 12, and the thermostat 23 are connected in series, but the present invention is not limited to this. For example, the first heater unit 11, the auxiliary heater unit 13, and the second heater unit 12 may be arranged in parallel. Further, as shown in FIG. 7, a circuit configuration is also conceivable in which the auxiliary heater portion 13 is continuously energized even after the thermostat 23 is turned off. In this case, since the thermostat 23 is not turned on again, the control is such that the heat generated only by the second heater unit 12 is continued.

Further, the positions where the first heater unit 11, the second heater unit 12, and the auxiliary heater unit 13 are arranged can be freely set. As in the above embodiment, it is preferable that the auxiliary heater unit 13 is located between the first heater unit 11 and the second heater unit 12. Here, the position between the first heater unit 11 and the second heater unit 12 includes both a circuit-like position and a mounting-like position, and it is sufficient that at least one of them is satisfied.

In particular, when the first heater unit 11, the second heater unit 12, and the auxiliary heater unit 13 are arranged in the vicinity, they may be affected by heat generation from each other. In that case, the first heater unit 11 and the auxiliary heater unit 11 and the auxiliary heater unit 11 may be affected by each other. It is preferable that the distance to the heater unit 13 and the distance between the second heater unit 12 and the auxiliary heater unit 13 are substantially the same. As a result, even when the heat from the auxiliary heater section 13 is transferred to the first heater section 11 and the second heater section 12, the heat is similarly transmitted to the first heater section 11 and the second heater section 12, and the first It is possible to prevent a difference in temperature between the heater unit 11 and the second heater unit 12. Further, the pattern of the conductor 1 on the first heater portion 11 side and the pattern of the conductor 1 on the second heater portion 12 side are symmetrical with respect to the line between the first heater portion 11 and the second heater portion 12. It is preferable that

In the above embodiment, the heater unit 31 is attached to the back side of the light-shielding hood 53, but the heater unit 31 may be attached to another place. For example, it can be attached to various places such as the front side of the light-shielding hood 53, the inside of the bracket 51, the outside of the bracket 51, the peripheral part of the camera unit (sensor unit) 55, and the passenger compartment side of the windshield 57. It can also be attached to.

Further, as the sensor unit, in addition to the camera unit 55 as in the above embodiment, a radar unit, a laser lidar unit, an ultrasonic sensor unit, and the like can be considered. The present invention can also be applied to a camera unit or a radar unit that is exposed and mounted outside the vehicle. In this case, it is conceivable to attach the heater unit around the light receiving portion of the camera unit or around the radome that covers the radar unit.

As described in detail above, according to the present invention, it is possible to obtain a heater unit which has a sufficient safety function and can contribute to power saving and space saving. Such a heater unit can be suitably used as a heat source for, for example, a household heater, an automobile interior heater, an industrial heater, various snow removal and deicing devices, an antifogging device, a heating cooker, and the like. Further, it can be used not only as a heater for conduction heat transfer that is used in contact with the object to be heated, but also as a heater for radiant heat transfer that is installed at a distance from the object to be heated. ..

1 Conductor 3 Lead part 5 Heater part 7 Base material 10 Main heater part 11 First heater part 12 Second heater part 13 Auxiliary heater part 23 Thermostat (temperature control device)
31 Heater unit 51 Bracket 53 Light-shielding hood 55 Camera unit (sensor unit)
57 Windshield

Claims (4)

It consists of a foil-shaped conductor, a planar base material on which the conductor is arranged, and a temperature control device that controls energization of the conductor.
The conductor is made of a single conductor foil, and is composed of a wide lead portion and a narrow heater portion, and the heater portion has a main heater portion and an auxiliary heater portion.
A heater unit in which the temperature control device is operated by heating the auxiliary heater unit. The heater according to claim 1, wherein the main heater portion is composed of at least a first heater portion and a second heater portion, and the auxiliary heater portion is located between the first heater portion and the second heater portion. unit. The heater unit according to claim 1, wherein the temperature control device is connected in series with both the main heater unit and the auxiliary heater unit. A heater unit according to any one of claims 1 to 3, a bracket attached to a windshield of a vehicle, a sensor unit housed in the bracket, and a light-shielding hood housed in the bracket.
A vehicle windshield device in which the heater unit is attached to the bracket, the sensor unit, or the light-shielding hood.

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