JP7411503B2 - Heater unit and its applied products - Google Patents

Description

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

A vehicle windshield device is attached to the cabin side of a windshield and is used to detect the presence or absence of other vehicles or obstacles in front of the vehicle. A vehicle windshield device includes a bracket fixed to the windshield, a camera unit or a radar unit supported by the bracket, and a light-shielding hood that suppresses external light such as sunlight from entering the camera unit. When the humidity inside the vehicle is high or the temperature outside the vehicle is low, fog, condensation, frost, ice, etc. adhere to the windshield, so the vehicle windshield device heats the light shielding hood. The heater unit is located behind the blackout hood. The heat emitted from this heater unit melts, evaporates, and removes fog, dew condensation, frost, ice, etc. adhering to the windshield facing the light shielding hood. Thereby, the photograph taken by the camera unit becomes clear. Moreover, accurate detection is possible without attenuation of the radar from the radar unit (see Patent Document 1, etc.).

As a heater unit, for example, in order to uniformly raise the temperature of a planar target area to be heated, a first linear heating element located at the periphery of the target area and a second linear heating element located inside the target area are used. A device is known that is provided with a heating element and a heating element separately (see Patent Document 2, etc.). Various types of linear heating elements are also known (see Patent Document 3, etc.). Various types of heater units are also known (see Patent Documents 4 and 5, etc.).

JP 2017-185893 Publication Utility model registration No. 1801190 Patent No. 6320935 JP 2019-93794 Publication JP 2019-104378 Publication

Conventional heater units use fuses to prevent excessive temperature rises. If unintended high-temperature heat is generated due to a short circuit or a failure in the control system, this fuse shuts off the current to the heater unit. The electricity supply was to be stopped. However, when installing a fuse, there are problems in that the number of parts increases, the thickness of the heater unit also increases, and irregularities in the shape of the fuse occur on the heater unit. Further, as a means for preventing excessive temperature rise without using a fuse, it is possible to use a positive temperature coefficient thermistor element (PTC element) as a heater element. There are ceramic-based PTC elements and organic-based PTC elements, and currently, organic-based PTC elements are mainly being studied for vehicle windshield devices. The reason behind this is that organic PTC elements, which can be easily processed into a thin planar shape like a film, are preferred because the range of objects to be heated is wide and there is not enough space to install a heater element. However, organic PTC elements suffer from the problem of deterioration in high-temperature environments and deterioration over time due to their structure, and in particular, they lack long-term durability and resistance to harsh temperature environments such as those used in automobiles. Its use remains limited in areas where it is required. On the other hand, ceramic PTC elements are hard and have a certain thickness, making it difficult to process them into thin planar shapes, so there is also the problem that they are not suitable for applications that uniformly heat a wide area. .

The present invention was made in order to solve the problems of the prior art, and its purpose is to provide a heater unit that has a function of preventing excessive temperature rise and has a uniform temperature; An object of the present invention is to provide a vehicle windshield device equipped with the following.

In order to achieve the above object, a heater unit according to the present invention includes a base material, a PTC heating element made of a ceramic positive temperature coefficient thermistor element on which a pair of electrodes are formed, a first electrode terminal, and a second electrode terminal. In the heater unit, the first electrode terminal and one electrode layer of the PTC heating element are electrically connected, and the second electrode terminal and the other electrode layer of the PTC heating element are electrically connected. electrically connected, the base material has a substantially planar portion formed therein, a recessed portion formed in the substantially planar portion, and the PTC heating element disposed within the recessed portion. In this case, one or both of the first electrode terminal and the second electrode terminal are disposed in the effective heating portion of the substantially flat surface of the base material.
Further, it is conceivable that one or both of the first electrode terminal and the second electrode terminal substantially covers the entire surface of the substantially flat portion of the base material.
Further, the second electrode terminal is disposed in the recess of the base material, the PTC heating element is held between the first electrode terminal and the second electrode terminal, and the first electrode terminal It is conceivable that the substantially flat portion of the base material is substantially covered.
Furthermore, it is conceivable that a stray light preventing material is formed on the outermost surface of the surface of the heater unit on which the PTC heating element is arranged.
Further, it is conceivable that one or both of the first electrode terminal and the second electrode terminal are biased in a direction to press down the PTC heating element.
A vehicle radar device according to the present invention includes the heater unit described above, a bracket attached to a windshield of a vehicle, and a sensor unit housed in the bracket.

According to the present invention, by using a PTC element as a heater element, it is possible to prevent an excessive rise in temperature. Furthermore, since the heater element is disposed in the recess of the base material, and the entire surface of the base material is substantially covered by one or both of the first electrode terminal and the second electrode terminal, the heater unit It can be flattened as . Furthermore, with this configuration, heat from the heater element is transferred through one or both of the first electrode terminal and the second electrode terminal, and the portion of the heater unit where the first electrode terminal and/or the second electrode terminal is arranged is heated. The entire area will generate heat evenly.

1 is a plan view showing the configuration of a heater unit according to Embodiment 1 of the present invention. FIG. 2 is a sectional view showing the configuration of a heater unit according to Embodiment 1 of the present invention, and is a sectional view taken along line II-II′ in FIG. 1. FIG. FIG. 2 is a perspective view showing the configuration of a first electrode terminal and a second electrode terminal of the heater unit according to Embodiment 1 of the present invention. 1 is a perspective view showing the configuration of a base material of a heater unit according to Embodiment 1 of the present invention. FIG. FIG. 2 is a plan view showing the configuration of a PTC heating element of the heater unit according to Embodiment 1 of the present invention. FIG. 3 is a plan view showing the configuration of a heater unit according to Embodiment 2 of the present invention. 7 is a sectional view showing the configuration of a heater unit according to Embodiment 2 of the present invention, and is a sectional view taken along line VII-VII′ in FIG. 6. FIG. FIG. 7 is a perspective view showing the configuration of a first electrode terminal and a second electrode terminal of a heater unit according to Embodiment 2 of the present invention. FIG. 7 is a perspective view showing the configuration of a base material of a heater unit according to Embodiment 2 of the present invention. FIG. 7 is a plan view showing the configuration of a PTC heating element of a heater unit according to Embodiment 2 of the present invention. 1 is a sectional view schematically showing a vehicle windshield device using a heater unit according to the present invention.

(Embodiment 1)
First, a first embodiment will be described with reference to FIGS. 1 to 5. This embodiment shows an example assuming that the heater unit according to the present invention is applied to a vehicle windshield device.

As shown in FIG. 4, the base material 15 is made of ABS resin and has a generally flat plate shape as a whole. On one principal surface of the base material 15, a substantially trapezoidal substantially planar portion 15a is formed over substantially the entire surface. A locking part 15c for holding a first electrode terminal 13a, which will be described later, is formed around the substantially flat part 15a except for the bottom on the long side, and the first electrode terminal 11a can be slid and attached. It looks like this. Further, a recess 15b is formed along the base of the long side of the trapezoid, and the shape of the recess 15b is a shape in which two rectangular parallelepipeds each having a length of 14.0 mm, a width of 50.0 mm, and a depth of 1.5 mm are connected. It becomes. Further, a pull-out groove 15d for pulling out a second electrode terminal 13b (to be described later) to the lead wire is formed continuously with the recess 15b.

The PTC heating element 11 consists of a barium titanate ceramic positive temperature coefficient thermistor element (PTC element) formed into a substantially rectangular plate shape with a length of 14.0 mm, a width of 50.0 mm, and a thickness of 1.2 mm. As shown, an electrode layer made of silver paste is formed on one main surface, and an electrode layer made of silver paste is also formed on the other main surface, which are referred to as electrode layer 11a and electrode layer 11b, respectively. , in FIG. 5, the electrode layer 11b is located on the back surface and is therefore not visible). One of the electrode layers 11a and 11b is a positive pole, and the other is a negative pole. Note that the material of the PTC heating element 11 may be appropriately set depending on the required heat generation characteristics (for example, Curie temperature, etc.). Note that in this embodiment, two PTC heating elements 11 are used.

In this embodiment, a first electrode terminal 13a and a second electrode terminal 13b made of a phosphor bronze plate with a thickness of 0.3 mm and excellent spring elasticity are used. FIG. 3 shows the first electrode terminal 13a and the second electrode terminal 13b. The first electrode terminal 13a has substantially the same shape as the substantially flat part 15a of the base material 15, and has a substantially trapezoidal shape with an upper base of 30 mm, a lower base of 180 mm, and a height of 70 mm. It has a continuous shape. Further, the second electrode terminal 13b has approximately the same shape as the recess 15b and the pull-out groove 15d of the base material 15, and has a shape in which two rectangles measuring 14.0 mm in length and 50.0 mm in width are connected. It has a shape in which a lead wire pull-out part is connected thereto. Moreover, there is a portion where the width is narrow in a part of the second electrode terminal 13b. If a short circuit occurs at any point for some reason, this narrow portion acts as a current fuse and breaks, thereby protecting other equipment and elements from overcurrent.

The assembly of these constituent materials will be explained below. FIG. 1 is a diagram showing the overall configuration of the heater unit 10, and FIG. 2 is a cross-sectional view taken along line II-II' in FIG. First, the second electrode terminal 13b is placed at the bottom of the recess 15b of the base material 15 and the extraction groove 15d. At this time, in order to bias the PTC heating element 1 in the direction of holding it down, the second electrode terminal 15b is curved so that the central portion is convex. Next, the PTC heating element 11 is placed in the recess 15b of the base material 15 so that the electrode layer 11b faces the bottom of the recess 15b and the electrode layer 11a faces the opening of the recess 15b. At the same time, an insulating spacer 17 made of ABS resin and having a thickness of 1.2 mm is placed in the lead-out groove 15d. Then, the first electrode terminal 13a is slid and inserted from the longer bottom side of the substantially trapezoidal flat portion 15a, and is fitted into the locking portion 15c. As a result, the PTC heating element 11 is sandwiched between the first electrode 13a and the second electrode 13b, the first electrode terminal 13a and one electrode layer 11a of the PTC heating element 11 are electrically connected, and the second The electrode terminal 13b and the other electrode layer 11b of the PTC heating element 11 are electrically connected. In addition, since the PTC heating element 11 and the second electrode terminal 13b are pressed against the bottom side of the recess 15b by the first electrode terminal 13a, the PTC The heating element 11 will be held down. In this way, the heater unit 10 according to the first embodiment is configured.

(Embodiment 2)
Next, a second embodiment will be described with reference to FIGS. 6 to 10. This embodiment shows an example assuming that a heater unit according to the present invention is attached to a vehicle windshield device.

As shown in FIG. 9, the base material 25 is made of ABS resin and has a generally flat plate shape as a whole. On one main surface of the base material 25, a substantially trapezoidal substantially planar portion 25a is formed over substantially the entire surface. Further, a recess 25b is formed along the base of the long side of the trapezoid, and the shape of the recess 25b is two rectangular parallelepipeds each measuring 14.0 mm in length, 50.0 mm in width, and 1.8 mm in depth. It has a shape.

The PTC heating element 21 consists of a barium titanate ceramic positive temperature coefficient thermistor element (PTC element) formed into a substantially rectangular plate shape with a length of 14.0 mm, a width of 50.0 mm, and a thickness of 1.2 mm. As shown, two electrodes made of silver paste are formed on one main surface in an interlaced comb-like shape, and serve as an electrode layer 21a and an electrode layer 21b, respectively. One of the electrode layers 21a and 21b is a positive pole, and the other is a negative pole. Note that the material of the PTC heating element 21 may be appropriately set depending on the required heat generation characteristics (for example, Curie temperature, etc.). Note that in this embodiment, two PTC heating elements 21 are used.

In this embodiment, a first electrode terminal 23a and a second electrode terminal 23b made of a phosphor bronze plate with a thickness of 0.3 mm and excellent spring elasticity are used. FIG. 8 shows the first electrode terminal 23a and the second electrode terminal 23b. The combined shape of the first electrode terminal 23a and the second electrode terminal 23b has substantially the same shape as the substantially flat portion 25a of the base material 25. The first electrode terminal 23a has a substantially trapezoidal shape with an upper base of 30 mm, a lower base of 139 mm, and a height of 54 mm, and has a lead wire extension portion connected thereto. The first electrode terminal 23a is provided with an L-shaped portion having a height of 0.6 mm by extending the two locations where the PTC heating element 21 is located, and folding those locations into the back side. This portion becomes a portion electrically connected to the electrode layer 21a of the PTC heating element 21. Further, the second electrode terminal 23b has a substantially trapezoidal shape with an upper base of 159 mm, a lower base of 180 mm, and a height of 8 mm, and has a lead wire extension portion connected thereto. The second electrode terminal 23b is provided with an L-shaped portion with a height of 0.6 mm by extending the two locations where the PTC heating element 21 is located, and folding these locations into the back side. This portion becomes a portion that is electrically connected to the electrode layer 21b of the PTC heating element 21. Further, a portion of the first electrode terminal 23a has a narrow portion. If a short circuit occurs at any point for some reason, this narrow portion acts as a current fuse and breaks, thereby protecting other equipment and elements from overcurrent.

The assembly of these constituent materials will be explained below. 6 is a diagram showing the overall configuration of the heater unit 20, and FIG. 7 is a cross-sectional view taken along the line VII-VII' in FIG. First, the PTC heating element 21 is placed in the recess 25b of the base material 25 so that the electrode layer 11a and the electrode layer 11b face the opening of the recess 25b. At this time, the electrode layer 21a is arranged to be on the short side of the substantially trapezoidal planar section 25a, and the electrode layer 21b is arranged on the long side of the substantially trapezoidal planar section 25a. The first electrode terminal 23a is arranged on the short bottom side of the substantially flat part 25a, and the first electrode terminal 23a is arranged on the long bottom side of the substantially flat part 25a. The interval between the first electrode terminal 23a and the second electrode terminal 23b is 8 mm, and an insulating spacer 27 made of ABS resin and having a thickness of 0.9 mm is placed in this interval. These first electrode terminal 23a, second electrode terminal 23b, and spacer 27 are fixed to the base material 25 with tapping screws (not shown). As a result, the PTC heating element 21 is sandwiched between the first electrode 23a and the second electrode 23b, the first electrode terminal 23a and one electrode layer 21a of the PTC heating element 21 are electrically connected, and the second The electrode terminal 23b and the other electrode layer 21b of the PTC heating element 21 are electrically connected.

In the heater units 10, 20 according to the first and second embodiments obtained as described above, both ends of the first electrode terminals 13a, 23a and the second electrode terminals 13b, 23 are pulled out and connected to lead wires (not shown). A connector (not shown) will be connected by this lead wire.

Such heater units 10, 20 can be installed inside a vehicle windshield device. An example of a vehicle windshield device will be described with reference to FIG. 11. The right side in FIG. 11 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 sensor unit 55. The bracket 51 is a resin member having a bowl shape, and houses the light shielding hood 53 and the sensor unit 55. Adhesive is applied to the peripheral edge of the bracket 51, and the bracket 51 is attached to the cabin side of the windshield 57. Note that the windshield 57 is generally sometimes referred to as a windshield, a side glass, or a rear glass. The sensor unit 55 is fixedly held by a resin member formed within the bracket. Note that the sensor unit 55 may be a camera unit, a radar unit, or the like. At this time, the light receiving section of the sensor unit 55 is directed toward the windshield 57, and no other member is interposed between the light receiving section of the sensor unit 55 and the windshield 57. In the vehicle windshield device, the light-shielding hood 53 is used to define the range of light received by the light-receiving section of the sensor unit 55, but the heater units 10 and 20 in the first and second embodiments can be used as is. It can be used as a light shielding hood 53.

When the heater units 10, 20 are used as the light-shielding hood 53, it is preferable that a stray light prevention material be formed on the outermost surface of the first electrodes 13a, 23a opposite to the surface in contact with the PTC heating elements 11, 21. This makes it possible to prevent external light from entering from outside the light receiving range. The anti-stray light material is sometimes referred to as an anti-reflection material, and examples thereof include non-woven fabrics and sheets whose surfaces have been subjected to processing such as pear processing, texture processing, matte processing, and flocking processing. Furthermore, as a measure to form a stray light prevention material, it is also possible to apply a matte paint.

When the humidity in the vehicle interior is high or the temperature outside the vehicle is low, fogging, dew condensation, frost, ice, etc. may adhere to the windshield 57. Light is scattered due to cloudiness, dew condensation, frost, ice, etc., and there is a possibility that clear photography by the sensor unit 55 may be hindered. This also applies when a radar unit is used instead of a camera unit. Therefore, the heater units 10 and 20 according to the present invention are used as the light-shielding hood 53, and by heating the windshield 57 with the heat emitted from the heater units 10 and 20, fogging, dew condensation, frost, and ice can be removed. Become. Further, the air inside the bracket 51 is heated by the heat from the heater units 10 and 20, and the humidity inside the bracket 51 is thereby reduced, thereby removing dew condensation.

Note that the present invention is not limited to the above embodiments. For example, the number of PTC heating elements 11 and 21 may be one, three, or more instead of two as in the above embodiment. Further, the shape of the base materials 15 and 25 is not limited to a flat plate shape, but may be a completely different shape. The positions of the recesses formed in the base materials 15 and 25, that is, the positions where the PTC heating elements 11 and 21 are arranged, can also be appropriately designed depending on the desired heat generation characteristics and usage environment.

In the base materials 15, 25, one or both of the first electrode terminals 13a, 23a and the second electrode terminals 13b, 23b are arranged in the effective heating part in the substantially flat parts 15a, 25a. The effective heating section is a section designed to generate heat. In the first embodiment, this is a portion where the first electrode terminal 13a is arranged, and in the second embodiment, this is a portion where the first electrode terminal 23a and the second electrode terminal 23b are arranged. Considering the fixation of the PTC heating elements 11 and 21 and the electrical connection of the PTC heating elements 11 and 21, the first electrode terminals 13a and 23a, and the second electrode terminals 13b and 23b, the area of the effective heating part is the recessed part 15b, It is preferable that the area is larger than that of 25b.

In particular, it is preferable that the entire substantially flat portions 15a, 25a are substantially covered by one or both of the first electrode terminals 13a, 23a and the second electrode terminals 13b, 23b. Here, it is not necessary that the entire area is substantially covered, and it is sufficient that the main parts of the substantially planar parts 15a and 25a are covered. For example, if 80% of the area of the substantially flat portions 15a, 25a is covered, it is considered that the entire area is substantially covered.

Further, the substantially flat portions 15a and 25a do not need to be completely flat, and may have slight irregularities or a slightly curved surface. For example, if the square root of the area of the substantially flat portions 15a and 25a is L, and the maximum value in the normal direction of the unevenness or curved portion is H, then if H/L>0.1, it is considered to be approximately flat.

It is also conceivable to attach a heat insulating material to the heater unit 31 so that the heat generated by the PTC heating elements 11 and 21 is not released to the outside. It is also conceivable to attach a cushioning material to protect it from external shocks. Since both the heat insulating material and the shock absorbing material are preferably made of various foamed resins or foamed rubbers, the member may serve as both a heat insulating material and a shock absorbing material. Further, it is also possible to use a combination of a plurality of heat insulating materials and cushioning materials having different properties such as heat insulating properties, heat resistance, shock absorption properties, and appearance.

As described in detail above, according to the present invention, it is possible to obtain a heater unit that has a function of preventing excessive temperature rise and has a uniform temperature. Such a heater unit can be suitably used as a various heat source, for example, in household heating equipment, automobile interior heating equipment, industrial heating equipment, various snow removal/ice melting equipment, anti-fog equipment, heating cooking equipment, etc. .

10, 20 Heater unit 11, 21 PTC heating element 11a, 11b, 21a, 21b Electrode layer 13a, 23a First electrode 13b, 23b Second electrode 15, 25 Base material 15a, 25a Substantially flat part 15b, 25b Recessed part

Claims (5)

A heater unit comprising a base material, a PTC heating element comprising a ceramic positive temperature coefficient thermistor element on which a pair of electrode layers is formed, a first electrode terminal, and a second electrode terminal,
The first electrode terminal and one electrode layer of the PTC heating element are electrically connected, and the second electrode terminal and the other electrode layer of the PTC heating element are electrically connected. ,
A substantially planar portion is formed in the base material, and a recess is formed in the substantially planar portion,
the PTC heating element is disposed within the recess;
Either the first electrode terminal or the second electrode terminal is larger than the area of the recess,
A heater unit characterized in that one or both of the first electrode terminal and the second electrode terminal substantially covers the entire surface of the substantially flat portion of the base material . the second electrode terminal is disposed within the recess of the base material,
The PTC heating element is held between the first electrode terminal and the second electrode terminal,
2. The heater unit according to claim 1 , wherein a substantially flat portion of the base material is substantially covered by the first electrode terminal. 3. The heater unit according to claim 1 , wherein a stray light preventing material is formed on the outermost surface of the surface of the heater unit on which the PTC heating element is arranged. The heater unit according to any one of claims 1 to 3 , wherein one or both of the first electrode terminal and the second electrode terminal are biased in a direction to press down the PTC heating element. . A vehicle windshield device comprising: the heater unit according to any one of claims 1 to 4 ; a bracket attached to a windshield of a vehicle; and a sensor unit housed in the bracket.

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