Heater Device

Abstract

To suppress peeling or deformation of a metal board bonded to an electrode formed in a PTC element.SOLUTION: A heating element comprises: an insulation substrate 57 to which an electrode is provided onto a front surface; a plurality of PTC elements 1 that is arranged onto the insulation substrate 57 along a predetermined arrangement direction, and in which the electrode is formed onto both main surfaces; and a metal board 56 that is bonded with an electrode 3 of the plurality of PTC elements 1 so as to be conducted, and is fixed to the insulation substrate 57. Each of electrodes 2 formed on one main surface side of the plurality of PTC elements 1 is connected to an electrode 55 of the insulation substrate 57 so as to be conducted. The metal board 56 includes: a flat plate part 561 that is connected to each electrode 3 formed on the plurality of PTC elements 1; leg parts 56a and 56b that are bent toward the insulation substrate 57 from the flat plate part 561, and are extended along a thickness direction of each PTC element 1; and fixing parts 56c and 56d that fix the leg parts 56a and 56b to the insulation substrate 57.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a heater device, and more particularly to a heater device using a PTC element as a heat generating element. [Background technology]

[0002] BACKGROUND ART Conventionally, for example, a PTC (Positive Temperature Coefficient) element has been used in a heater device for fixing toner in a copying machine (see Patent Document 1).

[0003] This copying machine is configured such that, after the toner has been transferred onto the paper, the paper is moved along the PTC element, whereby the toner is heated, melted, and fixed to the paper. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 06-175511 Summary of the Invention [Problem to be solved by the invention]

[0005] Furthermore, some conventional heater devices using PTC elements use multiple PTC elements lined up. For example, as shown in Figures 8 and 9, there is a heater device configured with multiple PTC elements 1 lined up and sandwiched between metal plates 5 and 6. Electrodes 2 and 3 formed on the front and back surfaces of each PTC element 1 are adhered to the metal plates 5 and 6.

[0006] In a heater device configured with a plurality of PTC elements 1 arranged in an array, slight gaps G1 are formed between the PTC elements 1, which causes the heater device as a whole to be easily deflected in the direction in which the PTC elements 1 are arranged.

[0007] 10, a heater device using a conventional PTC element has insulating layers 7 and 8 provided on metal plates 5 and 6, and a sliding member 9, which is the object to be heated, slides on one of the insulating layers 8. In such a configuration, when the PTC element 1 generates heat, adhesives 11 and 12 between the metal plates 5 and 6 and the electrodes 2 and 3 expand, and stress acting in the lateral direction (direction of arrow x) as the sliding member 9 slides causes the metal plates 5 and 6 to easily peel off from the electrodes 2 and 3, which is a problem.

[0008] The present invention has been made in consideration of the above points, and aims to provide a heater device that can suppress peeling and deformation of the metal plate joined to the electrode formed on the PTC element. [Means for solving the problem]

[0009] The heater device of the present invention comprises an insulating substrate having electrodes on its surface, a plurality of PTC elements arranged on the insulating substrate along a predetermined arrangement direction and having electrodes formed on both main surfaces, and a metal plate joined conductively to the electrodes of the PTC elements and fixed to the insulating substrate, wherein each of the electrodes formed on one main surface of the plurality of PTC elements is conductively connected to an electrode of the insulating substrate, and the metal plate has a flat portion connected to each of the electrodes formed on the other main surface of the plurality of PTC elements, leg portions bent from the flat portion toward the insulating substrate and extending along the thickness direction of the PTC elements, and a fixing portion for fixing the leg portions to the insulating substrate.

[0010] According to this configuration, by fixing a metal plate having legs onto an insulating substrate and sandwiching a PTC element between the metal plate and the insulating substrate so as to be conductive, peeling or deformation of the metal plate joined to the electrode formed on the PTC element can be suppressed.

[0011] Furthermore, the heater device of the present invention is characterized in that at least the flat portion of the metal plate has an insulating layer, the insulating layer is arranged so as to be in contact with a sliding member, and the sliding direction in which the insulating layer slides against the sliding member is perpendicular to the arrangement direction.

[0012] According to this configuration, the sliding direction in which the insulating layer slides against the sliding member is perpendicular to the arrangement direction of the PTC elements, so that the entire metal plate can be prevented from bending in the arrangement direction of the PTC elements, and as a result, the insulating substrate to which the metal plate is fixed can be prevented from bending.

[0013] Furthermore, in the heater device of the present invention, in the above configuration, the fixing portion includes a joining flange extending from the end of the leg portion opposite the flat portion along the surface of the insulating substrate, and the joining flange and the surface of the insulating substrate are adhered to fix the leg portion to the insulating substrate.

[0014] According to this configuration, the metal plate can be easily fixed onto the insulating substrate by adhering the joining flanges provided at the ends of the legs to the surface of the insulating substrate.

[0015] Furthermore, the heater device of the present invention is characterized in that, in the above configuration, the legs are formed on both sides of the flat plate portion centered on the arrangement direction, and the legs are fixed to the insulating substrate by two fixing portions formed on each of the legs.

[0016] According to this configuration, the legs are fixed to the insulating substrate by two fixing portions formed on each leg, thereby dispersing stress generated in the metal plate due to sliding with the sliding member.

[0017] In addition, in the above configuration, the heater device of the present invention is characterized in that, when a voltage is applied between a first terminal portion provided at the end of the electrode on the insulating substrate in the arrangement direction and a second terminal portion provided at the end of the metal plate in the arrangement direction, electricity is conducted to the multiple PTC elements.

[0018] According to this configuration, multiple PTC elements can be easily energized by applying a voltage between a first terminal portion provided at the end of the arrangement direction of the electrodes on the insulating substrate and a second terminal portion provided at the end of the arrangement direction of the metal plate. [Effects of the Invention]

[0019] According to the present invention, it is possible to suppress peeling and deformation of the metal plate joined to the electrodes formed on the PTC element. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a cross-sectional view showing a heater device according to an embodiment of the present invention. [Figure 2] 1 is a plan view showing a heater device according to an embodiment of the present invention; [Figure 3] 1 is an exploded perspective view showing a configuration of a heater device according to an embodiment of the present invention. [Figure 4] 1 is a perspective view showing a heater device according to an embodiment of the present invention; [Figure 5] FIG. 10 is a cross-sectional view showing a heater device according to another embodiment of the present invention. [Figure 6] FIG. 10 is a cross-sectional view showing a heater device according to another embodiment of the present invention. [Figure 7] FIG. 10 is a perspective view showing a heater device according to another embodiment of the present invention. [Figure 8] FIG. 10 is an exploded perspective view showing the configuration of a conventional heater device. [Figure 9] FIG. 10 is a perspective view showing a conventional heater device. [Figure 10] FIG. 10 is a cross-sectional view showing a conventional heater device. DETAILED DESCRIPTION OF THE INVENTION

[0021] [Embodiment] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 and 2, in which the same reference numerals are used to denote parts corresponding to those in Figures 8 to 10, a heater device 50 used as a toner fixing heater device in a copier has a configuration in which a PTC element 1, which is a heating element, is sandwiched between a ceramic substrate 57 (corresponding to the "insulating substrate" of the present invention) made of alumina or the like and a U-shaped metal plate 56 having a U-shaped cross section made of stainless steel or the like. As the material for the U-shaped metal plate 56, metals such as aluminum can also be used in addition to stainless steel.

[0022] An electrode 2 formed on one main surface of the PTC element 1 is fixed with an adhesive 11 to a substrate electrode 55 formed on the surface of a ceramic substrate 57. A bottom surface 56e of a flat portion 561 of a U-shaped metal plate 56 is fixed with an adhesive 12 to an electrode 3 formed on the other main surface of the PTC element 1. In other words, the flat portion 561 of the U-shaped metal plate 56 is laminated on the electrode 3 on the other main surface of the PTC element 1 via the adhesive 12.

[0023] U-shaped metal plate 56 is bent from both edges of bottom surface 56e toward ceramic substrate 57, forming legs 56a and 56b that extend along the thickness direction of PTC element 1. Legs 56a and 56b are bent at a 90-degree angle toward ceramic substrate 57 at bent portion 56g that runs along the arrangement direction of PTC elements 1 on ceramic substrate 57 (the direction of arrow y in FIG. 3).

[0024] At the tips of these two legs 56a, 56b opposite the flat portion 561, joining flanges 56c, 56d, which function as the "fixing portion" of the present invention, extend along the surface of the ceramic substrate 57, and the joining flanges 56c, 56d are fixed to the surface of the ceramic substrate 57 by adhesives 53, 54 (Figure 1).

[0025] As a result, the U-shaped metal plate 56 (legs 56a, 56b) is fixed to the ceramic substrate 57 by the joining flanges 56c, 56d via the adhesives 53, 54. That is, the bottom surface 56e of the U-shaped metal plate 56 is adhered to the electrode 3 of the PTC element 1, and the joining flanges 56c, 56d are also adhered to the ceramic substrate 57.

[0026] As shown in Figures 3 and 4, the heater device 50 clamps multiple PTC elements 1 between a ceramic substrate 57 of length L1 that allows multiple PTC elements 1 to be arranged in the direction of arrow y, and a U-shaped metal plate 56 of length L2 (approximately the same length as L1) that allows multiple PTC elements 1 arranged on the ceramic substrate 57 to be covered.

[0027] The substrate electrode 55 formed on the surface of the ceramic substrate 57 is formed to a size that allows the arrangement of electrodes 2 of multiple PTC components 1, and a terminal portion 55f (corresponding to the "first terminal portion" of the present invention) is provided at the edge of the substrate electrode 55 in the direction of the arrow y. Furthermore, the U-shaped metal plate 56 is provided with a terminal portion 56f (corresponding to the "second terminal portion" of the present invention) at the end portion in the direction of the arrow y (the same side as the side on which the terminal portion 55f is formed) of a joining flange 56d that is adhered to the ceramic substrate 57. By applying a voltage between these terminal portions 55f, 56f, it is possible to pass electricity through the multiple PTC components 1. In the configuration of this embodiment, the height of the substrate electrode 55 formed on the surface of the ceramic substrate 57 and the height of the joining flange 56d that is adhered to the surface of the ceramic substrate 57 match, so that the terminal portions 55f, 56f can be made the same height.

[0028] The width W1 of the substrate electrode 55 of the ceramic substrate 57 is smaller than the distance W2 between the two legs 56a, 56b of the U-shaped metal plate 56, thereby preventing contact between the substrate electrode 55 and the legs 56a, 56b of the U-shaped metal plate 56 when the U-shaped metal plate 56 is attached to the ceramic substrate 57. Note that an adhesive (insulating material) may be interposed between the PTC element 1 and the legs 56a, 56b to prevent contact between the PTC element 1 and the legs 56a, 56b.

[0029] With multiple PTC elements 1 and a U-shaped metal plate 56 adhered to a ceramic substrate 57, the surface of the U-shaped metal plate 56 is coated with glass or ceramic (such as boron nitride) by spray painting to form an insulating layer 58 (Figure 1).

[0030] The PTC element 1 is heated by passing current through the terminal portions 55f, 56f, and the sliding object 9, which is the object to be heated, can be heated by bringing the sliding object 9 into contact with the surface of the insulating layer 58. In this embodiment, the sliding direction of the sliding object 9 (the direction of the arrow x in FIG. 1) is set to a direction perpendicular to the extension direction (arrangement direction) of the legs 56a, 56b of the U-shaped metal plate 56, but this is not limiting, and for example, the sliding direction may be set to be along the extension direction of the legs 56a, 56b (the direction of the arrow y in FIG. 3).

[0031] In the above configuration, when the sliding member 9 slides on the U-shaped metal plate 56 in the direction of the arrow x (FIG. 1), stress in the x direction is applied to the U-shaped metal plate 56 due to friction between the sliding member 9 and the U-shaped metal plate 56 (insulating layer 58) as the U-shaped metal plate 56 slides in the direction of the arrow x. However, in addition to the adhesive portion (adhesive 12) between the bottom surface 56e and the electrode 3 of the PTC element 1 and the adhesive portion (adhesive 11) between the substrate electrode 55 and the electrode 2 of the PTC element 1, the two legs 56a, 56b of the U-shaped metal plate 56 are adhesively fixed to the hard ceramic substrate 57 via the joining flanges 56c, 56d. Therefore, the entire adhesive portion is subjected to the stress, and the stress can be dispersed. This allows the U-shaped metal plate 56 to reduce the stress applied to the adhesive joint between the bottom surface 56e and electrode 3 of the PTC element 1 and the adhesive joint between the substrate electrode 55 and electrode 2 of the PTC element 1, thereby preventing the U-shaped metal plate 56 from peeling off from the PTC element 1.

[0032] Furthermore, the bent portion 56g between the bottom surface 56e and the legs 56a, 56b of the U-shaped metal plate 56 is formed along the arrangement direction of the PTC elements 1 (the direction of the arrow y in FIG. 3). That is, the bent portion 56g is formed along the longitudinal direction in which the PTC elements 1 are arranged, and connects and fixes a plurality of PTC elements. This makes it possible to prevent bending in the longitudinal direction and to prevent peeling of the adhesive portion between the electrode 3 of the PTC element 1 and the U-shaped metal plate 56 (bottom surface 56e) and the adhesive portion between the electrode 2 of the PTC element 1 and the substrate electrode 55 of the ceramic substrate 57. [Example]

[0033] Electrodes were formed by printing aluminum paste on a ceramic (alumina) substrate. As shown in Figure 4, the PTC element 1 was a rectangular parallelepiped element with dimensions of 25 mm x 7 mm x 2.0 mm (t) and a Curie point of 250°C. Printed electrodes 2 and 3, each measuring 24 mm x 6 mm, were formed on both main surfaces. A substrate electrode 55 measuring 230 mm x 6 mm (W1) was formed on a ceramic (alumina) substrate measuring 235 mm (L1) x 12 mm x 0.635 mm (t). A U-shaped metal plate 56 was fabricated by bending a stainless steel plate (SUS430). The U-shaped metal plate 56 was fabricated by processing the stainless steel plate to a length (L2) of 230 mm, a width of 11.5 mm, and a width (W2) of 7.5 mm at the bottom surface 56e.

[0034] Silicone adhesive was applied to both electrode surfaces of the PTC element 1, and ten PTC elements 1 were arranged on substrate electrodes 55 on a ceramic (alumina) substrate 57, which were then sandwiched from above by a U-shaped metal plate 56. The adhesive was cured for one hour in an oven at 150°C while applying pressure to achieve adhesion. After that, a glass coating was applied to the U-shaped metal plate 56 to form an insulating layer 58 (Figure 1), which improved sliding properties and provided insulation.

[0035] [Other embodiments] In the above-described embodiment, the U-shaped metal plate 56 is fixed to the ceramic substrate 57 by forming joining flanges 56c, 56d at the tips of the legs 56a, 56b of the U-shaped metal plate 56 and adhering the joining flanges 56c, 56d to the surface of the ceramic substrate 57. However, this is not limited to this. For example, as shown in FIG. 5, the tips 56h, 56i of the legs 56a, 56b of the U-shaped metal plate 56 may be wrapped around to the back surface 57b of the ceramic substrate 57 and adhered to the back surface 57b of the ceramic substrate 57 with adhesives 15, 16.

[0036] In this way, by wrapping the tips 56h, 56i of the legs 56a, 56b around the rear surface 57b side of the ceramic substrate 57, the U-shaped metal plate 56 can be fixed to the ceramic substrate 57 even more firmly.

[0037] In the above-described embodiment, the legs 56a and 56b are formed on both sides of the flat plate portion 561 centered in the arrangement direction (y direction), and the U-shaped metal plate 56 (both legs 56a and 56b) is fixed to the ceramic substrate (insulating substrate) 57 by two joining flanges (fixing portions) 56c and 56d formed on each of the legs 56a and 56b. However, this is not limited to this. Fixing portions may be provided only on one side of the flat plate portion 561, and the metal plate may be fixed to the insulating substrate by one fixing portion. For example, as shown in FIG. 6 , the leg 56b and the fixing portion (joint flange 56d) may be formed on one side of the flat plate portion 561 of the U-shaped metal plate 56 in the sliding direction and fixed to the insulating substrate (ceramic substrate 57) by adhesive 54, while only the leg 56a may be formed on the other side in the sliding direction. In this case, the lower end of the leg 56a may be bonded to the insulating substrate (ceramic substrate 57) by adhesive 53. When the stress generated in the U-shaped metal plate 56 due to sliding with the sliding member 9 is relatively weak, the above-described configuration can be used with a simpler structure and method (the number of adhesive points can be reduced by having only one fixing part), thereby preventing peeling and deformation of the metal plate joined to the electrode formed on the PTC element 1.

[0038] In addition, in the above-described embodiment, the terminal portion 56f of the U-shaped metal plate 56 is provided on the joining flange 56d of the leg portion 56b as shown in FIG. 4, but this is not limited to this, and the terminal portion 56f may be provided on the bottom surface 56e of the U-shaped metal plate 56, for example, as shown in FIG.

[0039] Furthermore, in the above-described embodiment, the bent portion 56g between the bottom surface 56e of the U-shaped metal plate 56 and the legs 56a, 56b is bent at an angle of 90 degrees, but this is not limited to this, and the bent portion 56g may be formed in a rounded R-shape having a predetermined bending radius.

[0040] Furthermore, in the above-described embodiment, the heater device 50 according to the present invention is described as being used as a heater device for fixing toner in a copier, but the present invention is not limited to this and can be widely applied to various heating devices, such as a heating device for a film laminator.

[0041] Although the embodiments of the present invention have been described above based on examples, the scope of the present invention should not be considered to be limited to these embodiments. The scope of the present invention is not limited to the above description, but is defined by the claims, and includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0042] 1 PTC element 2, 3 electrodes 9. Sliding Objects 11, 12, 53, 54 Adhesive 55 Substrate electrode 55f, terminal portion (first terminal portion) 56f Terminal part (second terminal part) 56 U-shaped metal plate (metal plate) 56a, 56b Legs 56c, 56d Joint flange (fixed part) 56e bottom 56g bending part 561 Flat plate part 57 Ceramic substrate (insulating substrate) 58 Insulating layer

Claims

1. an insulating substrate having electrodes provided on its surface; a plurality of PTC elements arranged on the insulating substrate in a predetermined arrangement direction, each having electrodes formed on both main surfaces; a metal plate that is electrically connected to the electrodes of the plurality of PTC elements and is common to the electrodes of the plurality of PTC elements fixed to the insulating substrate, Each electrode formed on one main surface of the plurality of PTC elements is electrically connected to an electrode of the insulating substrate, The heater device is characterized in that the metal plate has a flat portion connected to each electrode formed on the other main surface side of the multiple PTC elements, a leg portion bent from the flat portion toward the insulating substrate and extending along the thickness direction of the PTC elements, and a fixing portion for fixing the leg portion to the insulating substrate.

2. At least the flat plate portion of the metal plate has an insulating layer, and the insulating layer is disposed so as to come into contact with a sliding member; The sliding direction in which the insulating layer slides on the sliding member is perpendicular to the arrangement direction.

2. The heater device according to claim 1.

3. The fixing portion includes a joining flange extending from the end of the leg portion opposite the flat portion along the surface of the insulating substrate, and the joining flange and the surface of the insulating substrate are bonded to fix the leg portion to the insulating substrate.

3. The heater device according to claim 1, wherein the heater device comprises: a heater element;

4. 4. A heater device according to claim 1, wherein the legs are formed on both sides of the flat portion centered on the arrangement direction, and the legs are fixed to the insulating substrate by two fixing portions formed on each of the legs.

5. When a voltage is applied between a first terminal provided at an end of the electrode on the insulating substrate in the arrangement direction and a second terminal provided at an end of the metal plate in the arrangement direction, the PTC elements are energized.

5. The heater device according to claim 1, wherein the heater device comprises: a heat exchanger;

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