Electric heater

Abstract

To remove an electrode plate opposite to a heat generation element, and couple a plus electrode and a minus electrode at a portion requiring a radiation fin with high conductivity, and at a portion requiring an insulation with high insulation quality.SOLUTION: An electric type heater comprises: a flat-plate like heat generation element; a non-conductive material holding plate that holds a plurality of heat generation elements in a first direction as a plate surface direction, and exposes both surfaces of each heat generation element in a second direction orthogonal to the first direction; and a conductive material radiation fin that is arranged in an air path to conduct heat of each heat generation element, and is in contact with each heat generation element in a second direction. A plus electrode and a minus electrode are in contact with a radiation fin and each holding plate outside the first direction from a position where the radiation fin is in contact with each heat generation element. Since it is in contact with the radiation fin, the plus electrode, the minus electrode, and each heat generation element can be electrically connected by using the radiation fin, and installation of the electrode plate is unnecessary. The holding plate can prevent the plus electrode and the minus electrode from short-circuiting with each heat generation element.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to an electric heater that heats air, and is suitable for use, for example, in heating the interior of an automobile. [Background technology]

[0002] A known structure for electric heaters is to place frames on both sides of the heating element in a first direction, which is the plate surface direction of the heating element, and press the frames toward the heater section to crimp the heating element, heat dissipation fins, and electrode plate in the heater section. In Patent Document 1, a spring is used to press the frame toward the heater section.

[0003] However, in Patent Document 1, the electrode plate may act as a thermal resistor, which may reduce heat dissipation efficiency. Also, in Patent Document 1, multiple heat generating elements are arranged in parallel, which may result in a long electrode plate and increase manufacturing costs.

[0004] On the other hand, in Patent Document 2, power is supplied directly from the positive electrode to the heating element via a heat dissipation fin without using an electrode plate, and a heat dissipation fin is also used to ground the heating element.

[0005] However, in Patent Document 2, a thermally and electrically conductive elastic body needs to be placed between the heating element and the heat dissipation fin. Therefore, a special process of baking a graphite filler layer is required to connect the heating element and the heat dissipation fin. Although it can be used to form an electric heater by pressing a spring as shown in Patent Document 1, the additional process of baking the graphite filler layer makes it impractical. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-85696 [Patent Document 2] Japanese Patent Application Publication No. 62-107261 Summary of the Invention [Problem to be solved by the invention]

[0007] In view of the above, the present disclosure is based on a configuration in which a spring is used to press the frame toward the heater, eliminating the electrode plate facing the heat-generating element, and aims to connect the positive and negative electrodes to the heat dissipation fins with good conductivity in areas where conductivity is required and with good insulation in areas where insulation is required. [Means for solving the problem]

[0008] The first aspect of the present disclosure is an electric heater comprising: a flat heating element that generates heat when current is applied; a holding plate made of a non-conductive material that holds a plurality of the heating elements in a first direction, which is the direction of the flat plate surface, and exposes both sides of the heating element in a second direction perpendicular to the first direction; a heat dissipation fin made of a conductive material that is arranged in an air passage to transfer heat from the heating element to the air passage and that contacts the heating element in the second direction; and a positive electrode and a negative electrode that connect to a power source.

[0009] The first electric heater of the present disclosure also includes a pair of frames arranged on both outer sides of the heat dissipation fins and the holding plate in the second direction and sandwiching the heat dissipation fins and the holding plate, and a pair of springs arranged on both outer sides of the heat dissipation fins and the holding plate in the first direction and pressing the frames inward in the second direction.The first electric heater of the present disclosure is structured so that the positive electrode and the negative electrode contact the heat dissipation fins and the holding plate outward in the first direction from the position where the heat dissipation fins contact the heat generating element.

[0010] In the first electric heater of the present disclosure, the positive and negative electrodes contact the heat dissipation fins outward in the first direction from the position where the heat dissipation fins contact the heat generating element, so the heat dissipation fins can be used to electrically connect the positive and negative electrodes to the heat generating element, eliminating the need to install a separate electrode plate.

[0011] Furthermore, in the first electric heater of the present disclosure, the positive and negative electrodes also contact the holding plate outward in the first direction from the position where the heat dissipation fins contact the heating element. Because the holding plate is made of a non-conductive material, the holding plate can prevent the positive and negative electrodes from shorting out with the heating element. The first electric heater of the present disclosure achieves electrical insulation by effectively utilizing the holding plate that holds the heating element. That is, one of the two surfaces of the heating element is electrically connected to the first plate member of the heat dissipation fin, and the other of the two surfaces of the heating element is electrically connected to the second plate member of the adjacent heat dissipation fin, and the first plate member of the heat dissipation fin and the second plate member of the adjacent heat dissipation fin are electrically insulated by the holding plate. Furthermore, in a fifth electric heater of the present disclosure, the heat dissipation fins, holding plates, positive electrodes, and negative electrodes are stacked in multiple layers in the second direction. The positive electrodes and negative electrodes are arranged alternately. The amount of heat generated by the heating element can be controlled by changing the number of positive electrodes to which current is applied.

[0012] In the second electric heater of the present disclosure, the positive and negative electrodes contact the heat dissipation fins on the inside of the spring in the first direction. The positive and negative electrodes are held between the heat dissipation fins and the holding plate by their own elastic force and the elastic force of the spring. Because the positive and negative electrodes of the second electric heater of the present disclosure are held by elastic force, assembly of the positive and negative electrodes is easy.

[0013] In a third aspect of the present disclosure, the heat dissipation fin includes a pair of first and second plate members and a fin member disposed between the first and second plate members. The holding plate is sandwiched between the first and second plate members of the adjacent heat dissipation fin, and the positive and negative electrodes are sandwiched between the first plate member and the holding plate. Because the positive and negative electrodes of the third electric heater of the present disclosure are sandwiched between the first plate member and the holding plate, assembly of the positive and negative electrodes is easy.

[0014] In a fourth electric heater of the present disclosure, a case made of a non-conductive material is disposed outside the heat dissipation fins and the holding plate in the first direction. The positive and negative electrodes contact the heat dissipation fins on the inside of the case in the first direction, and are held between the heat dissipation fins and the case by their own elastic force. Because the positive and negative electrodes of the fourth electric heater of the present disclosure are held between the heat dissipation fins and the case by their elastic force, assembly of the positive and negative electrodes is easy. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a front view of the electric heater of the present disclosure. [Figure 2] FIG. 2 is an exploded front view of the electric heater of FIG. [Figure 3] FIG. 3 is an enlarged cross-sectional view of the heating element and electrode portion of the electric heater of FIG. [Figure 4] FIG. 4 is a cross-sectional view showing the heat dissipation fins, the holding plate, and the electrodes. [Figure 5] FIG. 5 is a perspective view showing the holding plate. [Figure 6] FIG. 6 is a front view showing the heat dissipation fins. [Figure 7] FIG. 7 is a side view of the heat dissipation fin shown in FIG. [Figure 8] FIG. 8 is a front view showing a state in which frames are arranged on both ends of the heater unit. [Figure 9] FIG. 9 is an enlarged cross-sectional view of a heating element and an electrode portion of another example of an electric heater. [Figure 10] FIG. 10 is a cross-sectional view taken along line XX in FIG. [Figure 11] FIG. 11 is an enlarged cross-sectional view of a heating element and an electrode portion of another example of an electric heater. [Figure 12] FIG. 12 is a cross-sectional view showing a housing used in another example of an electric heater. [Figure 13] FIG. 13 is a side view taken along line XIII in FIG. [Figure 14] FIG. 14 is a cross-sectional view showing the state in which the housing shown in FIG. 12 is assembled into the electric heater shown in FIG. [Figure 15] FIG. 15 is a front view showing a state in which the case and the second case are assembled to the heater unit. DETAILED DESCRIPTION OF THE INVENTION

[0016] An example of the present disclosure will now be described with reference to the drawings. FIG. 1 is a front view showing an example of an electric heater 100. The electric heater 100 is used together with an automotive air conditioner. The automotive air conditioner uses engine coolant as its heat source for heating. However, immediately after the engine is started, the engine coolant is not yet warmed, resulting in a shortage of heat source for heating. In particular, as engines become smaller due to hybridization of automobiles and the engine operating rate decreases, the shortage of heat in the engine coolant becomes more pronounced.

[0017] The electric heater 100 is used to compensate for this lack of heat source. It is placed downstream of the air flow of the heater core of an automotive air conditioner, and heats the air sent from the air conditioner's blower fan. Figure 2 is a front view showing the components of this electric heater 100 exploded.

[0018] Reference numeral 110 denotes a heating element such as a PTC element, which generates heat when electricity is applied. A PTC (Positive Temperature Coefficient) element has the property that its electrical resistance increases rapidly above a certain temperature, so it generates heat when electricity is applied. However, when the temperature at which it generates heat exceeds a certain temperature, the electrical resistance becomes too high and almost no current flows, preventing it from generating heat above a certain temperature. Therefore, using this element can prevent the heater from overheating.

[0019] The heating element 110 has a rectangular shape measuring approximately 35 mm in length, 7 mm in width, and 1 mm in thickness, and is held in a holding portion 121 of a holding plate 120 made of a non-conductive resin material such as nylon. As shown in Fig. 5, the holding plate 120 has a roughly H-shaped cross section and is slightly more than 1 mm in height. Between side walls 122 of the holding plate 120, holding portions 121 that form spaces to accommodate the heating elements 110 and bottom portions 123 that maintain the spacing between adjacent heating elements 110 are formed alternately.

[0020] The thickness of the bottom 123 is about 1 millimeter, which is set to be approximately the same as but slightly smaller than the thickness of the heating element 110. Therefore, when the heating element 110 is stored in the holding portion 121 of the holding plate 120, one side 111 and the other side 112 of the heating element 110 are reliably exposed. Note that the other side 112 of the heating element 110 faces the bottom 123.

[0021] Here, the direction in which the heat generating elements 110 are arranged in the direction of the plate surface of the holding plate 120 is defined as the first direction (shown in FIG. 1). The direction perpendicular to the first direction is defined as the second direction. Heat dissipation fins 130 are arranged on both sides of the second direction between the side walls 122 of the holding plate 120. Therefore, one side 111 and the other side 112 of the heat generating element 110 are joined to the adjacent heat dissipation fin 130 in the second direction. While the side walls 122 are highlighted in FIG. 5, the heat dissipation fins 130 are arranged so as to be in contact with the air as much as possible. The side walls 122 function to prevent the heat generating elements 110 from falling off and to position the heat dissipation fins 130 for easy assembly. Therefore, the heat dissipation fins 130 are not deeply embedded in the holding plate 120.

[0022] 6 and 7, the heat dissipation fins 130 are formed by sandwiching a fin member 131 between a first plate member 132 and a second plate member 133. The fin member 131 is made of an aluminum alloy containing manganese and is formed by bending it multiple times. The first plate member 132 and the second plate member 133 are also made of an aluminum alloy, and their ends are bent at approximately right angles to form an L shape. The thickness direction of the first plate member 132 and the second plate member 133 engages with the side wall 122 of the holding plate 120. Because the heat dissipation fins 130 engage with the side wall 122 by the thickness of the first plate member 132 and the second plate member 133, contact with air is not hindered by the holding plate 120.

[0023] The fin member 131, the first plate member 132, and the second plate member 133 are integrally brazed together. The heat dissipation fin 130 is approximately 10 mm high and 7 mm wide. The length of the heat dissipation fin 130 varies depending on the capacity required for the electric heater 100, but is approximately 180 to 280 mm.

[0024] The holding plate 120 has an electrode holding portion 124 formed at an end in the first direction that holds the electrode 140. As shown in FIGS. 4 and 5, the electrode holding portion 124 opens toward the first plate member 132 of the heat dissipation fin 130 and is spaced apart from the second plate member 133. Therefore, when the electrode 140 is housed in the electrode holding portion 124, it can come into contact with the first plate member 132 and be electrically connected. Furthermore, since the electrode holding portion 124 is made of a resin material, it is electrically insulated from the second plate member 133. As will be described later, one surface 111 and the other surface 112 of the heat generating element 110 and the electrode 140 are electrically connected via adjacent heat dissipation fins 130.

[0025] In particular, as shown in Fig. 4, electrode 140 has elastically deforming portion 143 that is bent so as to convex toward first plate member 132, and is therefore structured so that it can reliably contact first plate member 132 due to the elastic force of electrode 140 itself. Note that Fig. 4 shows the shape of electrode 140 in a free state so that the shape of elastically deforming portion 143 can be seen. When electrode 140 is in contact with first plate member 132, as shown in Fig. 3, elastically deforming portion 143 of electrode 140 is pressed against first plate member 132 and elastically deforms to crush so as to conform to the shape of first plate member 132.

[0026] The electrodes 140 include a positive electrode 142 that receives power from a battery (not shown) and a negative electrode 141. In the example of FIGS. 1 to 3, the heat dissipation fins 130 are arranged in five layers. Four layers of holding plates 120 that hold the heat generating elements 110 and the electrodes 140 are arranged between the heat dissipation fins 130. At the bottom of the figure, one layer of holding plate 120 that holds only the electrodes 140 is arranged. Thus, the electrodes 140 are arranged in five layers, with the positive electrodes 142 and the negative electrodes 141 arranged alternately. Note that the holding plate 120 at the bottom of the figure does not hold the heat generating elements 110, but does have a holding portion 121. This allows the shapes of all the holding plates 120 to be uniform, improving productivity.

[0027] In this way, the heat dissipation fins 130, the holding plates 120, and the electrodes 140 are stacked in multiple layers to form the heater section 150. Note that the first direction in the arrangement direction is the direction perpendicular to the stacking direction (the left-right direction in FIG. 1). The stacking direction perpendicular to the first direction (the up-down direction in FIG. 1) is the second direction.

[0028] 1 and 2, the first and fourth holding plates 120 from the top of the drawing have heating elements 110 arranged at two locations, one at each end in the second direction. The second and third holding plates 120 from the top have heating elements 110 arranged at two locations, one at the end and one toward the center. As mentioned above, no heating elements 110 are arranged on the lowest holding plate 120.

[0029] Therefore, the arrangement of the heating elements 110 in the heater section 150 as a whole is balanced in both the first and second directions of the heater section 150. As a result, the air passing through the electric heater 100 has a uniform temperature, contributing to temperature control of the automotive air conditioner. The length of the heater section 150 in the first direction and the length of the heater section 150 in the second direction are set according to the duct of the automotive air conditioner. In the present disclosure, the width in the first direction is approximately 200 to 300 millimeters, and the width in the second direction is approximately 50 to 100 millimeters.

[0030] The heat generation amount of the heat generating element 110 is controlled by changing the number of positive electrodes 142 to be energized. To obtain the maximum heat generation amount, all positive electrodes 142 are energized. At this time, the other side 112 of the heat generating element 110 arranged on the first holding plate 120 from the top is in contact with the second plate member 133 of the heat dissipation fin 130 below. Therefore, the other side 112 of the heat generating element 110 is electrically connected to the negative electrode 141 via the first plate member 132 of the heat dissipation fin 130 located below, the fin member 131, and the second plate member 133. The voltage of the positive electrode 142 is applied to the one side 111 of the heat generating element 110 arranged on the first holding plate 120 from the top via the first plate member 132 of the heat dissipation fin 130 located above.

[0031] Similarly, one surface 111 of the heat generating element 110 arranged on the second-from-top holding plate 120 is electrically connected to the negative electrode 141 via the first plate member 132 of the heat dissipation fin 130 located above. The other surface 112 of the heat generating element 110 is in contact with the second plate member 133 of the heat dissipation fin 130 located below, and therefore a voltage is applied from the positive electrode 142 arranged below via the second plate member 133, the fin member 131, and the first plate member 132.

[0032] In this way, each heating element 110 receives a voltage from the heat dissipation fin 130 on the side with which the positive electrode 142 contacts, and conducts to the heat dissipation fin 130 on the side with which the negative electrode 141 contacts. In other words, one surface 111 of each heating element 110 contacts the first plate member 132 of the heat dissipation fin 130, and the other surface 112 contacts the second plate member 133. The positive electrode 142 and the negative electrode 141 are in contact with the first plate member 132. Therefore, the voltage from the positive electrode 142 is applied to the one surface 111 of the heating element 110 with which the first plate member 132 contacts, via the first plate member 132, and is applied to the other surface 112 of the heating element 110 with which the second plate member 133 contacts, via the first plate member 132 and the fin member 131, from the second plate member 133.

[0033] The same is true for the negative electrode 141. In the heating element 110 in which the first plate member 132 is in contact with the negative electrode 141, electrical conduction occurs from one surface 111 through the first plate member 132. In addition, in the heating element 110 in which the second plate member 133 is in contact, electrical conduction occurs through the first plate member 132 and the fin member 131 to the second plate member 133 to the other surface 112.

[0034] Furthermore, since both the positive electrode 142 and the negative electrode 141 of the electrode 140 are housed in the electrode holding portion 124 of the holding plate 120, good insulation is maintained. That is, the electrode 140 is in contact only with the first plate member 132 of the heat dissipation fin 130, and is isolated from the second plate member 133 by the holding plate 120. Therefore, there is no short circuit between the second plate member 133 and the heating element 110.

[0035] The amount of heat generated by the heater unit 150 can be controlled by increasing or decreasing the number of positive electrodes 142 to be energized. Of the three positive electrodes 142, the upper positive electrode 142 is referred to as the first positive electrode 1420, the central positive electrode 142 is referred to as the second positive electrode 1421, and the lower positive electrode 142 is referred to as the third positive electrode 1422. Of the two negative electrodes 141, the upper negative electrode 141 is referred to as the first negative electrode 1410, and the lower negative electrode 141 is referred to as the second negative electrode 1411. The first positive electrode 1420 is electrically connected to the first negative electrode 1410, and the second positive electrode 1421 is electrically connected to the first negative electrode 1410 and the second negative electrode 1411. The third positive electrode 1422 is electrically connected to the second negative electrode 1411.

[0036] The voltage from the first positive electrode 1420 is applied to the first two heating elements 110 from the top. Meanwhile, the voltage from the second positive electrode 1421 is applied to the second and third four heating elements 110 from the top. And the voltage from the third positive electrode 1422 is applied to the fourth two heating elements 110 from the top. For example, a voltage of 150 watts is applied to the first positive electrode 1420 and the third positive electrode 1422, and a voltage of 300 watts is applied to the second positive electrode 1421.

[0037] Therefore, the amount of heat generated is greatest when all of the first positive electrode 1420, the second positive electrode 1421, and the third positive electrode 1422 are energized. The next largest amount of heat is generated when the second positive electrode 1421 and either the first positive electrode 1420 or the third positive electrode 1422 are energized. The next largest amount of heat is generated when only the second positive electrode 1421 is energized or when both the first positive electrode 1420 and the third positive electrode 1422 are energized. Finally, the smallest amount of heat is generated when only the first positive electrode 1420 or the third positive electrode 1422 is energized. In any of these heat generation states, the heating element 110 in the heater section 150 is balanced in both the first and second directions. Therefore, when installed in an automotive air conditioning system, the air can be heated uniformly.

[0038] In the present disclosure, as described above, one surface 111 of the heat generating element 110 is in contact with the first plate member 132 of the heat dissipation fin 130, and the other surface 112 is in contact with the second plate member 133. Therefore, heat from the heat generating element 110 is transferred directly to the heat dissipation fin 130, and the heat of the heat generating element 110 can be used efficiently. In addition, the heat dissipation fin 130 is designed to be in contact with air on as many surfaces as possible, including the first plate member 132 and the second plate member 133, so heat exchange with the air is efficient.

[0039] Stainless steel frames 160 are arranged on both sides of the heater section 150 in the second direction to hold the heater section 150 in place. The length of the frames 160 in the first direction is equal to or slightly longer than that of the heat dissipation fins 130. The frame 160 has a U-shaped cross section, which increases its rigidity in the second direction. In a free state, the frame 160 is convex inward in the second direction (see FIG. 8). The width of the frame 160 is about 8 mm, the same as the thickness of the heater section 150, and the height of the frame 160 is about 10 mm. The thickness of the frame 160 is about 1 mm.

[0040] As shown in FIG. 2, springs 170 are disposed on both sides of frame 160 in the first direction. Spring 170 is a stainless steel rod with a diameter of approximately 4 millimeters. Spring 170 has a straight portion 171 that follows the end of heater section 150 in the second direction, bent portions 172 formed at both ends of the straight portion in the second direction, and pressing portions 173 that press frame 160 toward heater section 150. Spring 170 has elasticity due to bent portions 172, and presses frame 160 toward heater section 150 (inward in the second direction) with a force of approximately 50 to 190 Newtons. As will be described later, spring 170 is housed in a case 180 made of polybutylene terephthalate (PBT).

[0041] The connections between the electrode 140 of the heater section 150, the heat dissipation fins 130, and the holding plate 120, and between the heater section 150 and the frame 160, are maintained solely by the pressing force of this spring 170. In other words, the electrodes 140, the heat dissipation fins 130, the holding plate 120, and the frame 160 are mechanically assembled together, and are not fixed by brazing, welding, or the like.

[0042] As a result, electrode 140 is mechanically sandwiched in the second direction between electrode holding portion 124 of holding plate 120 and first plate member 132 of heat dissipation fin 130. This sandwiched state is maintained by the elastic force acting outward in the second direction of elastic deformation portion 143 of electrode 140 and the elastic force acting inward in the second direction of spring 170. There is no longer any need to use special fixing work such as soldering to fix electrode 140, improving assembly ease.

[0043] Furthermore, since the electrode 140 is mechanically sandwiched between the electrode holding portion 124 of the holding plate 120 and the first plate member 132 of the heat dissipation fin 130, the electrode 140 does not extend to the heating element 110. This makes it possible to reduce the height of the heater portion 150 in the second direction. Furthermore, as described above, heat from the heating element 110 is not transferred to the electrode 140 but is transferred directly to the heat dissipation fin 130, improving heat transfer efficiency. Note that, since the bottom portion 123 of the holding plate 120 is interposed between the electrode 140 and the heating element 110 in the first direction, there is no electrical short circuit with the heating element 110.

[0044] 9 and 10 show other shapes of the elastically deforming portion 143. In this example, the end portion 145 of the electrode 140 is formed to be wide in the width direction of the heat dissipation fin 130, which is perpendicular to the first direction and the second direction. This end portion 145 is bent toward the first plate member 132 of the heat dissipation fin 130 (in the second direction) to form the elastically deforming portion 143. The elastically deforming portion 143 comes into contact with the first plate member 132 of the heat dissipation fin 130 over a larger area.

[0045] However, the elastic deformation portion 143 is not necessarily required. For example, a protrusion may be provided on the electrode holding portion 124 of the holding plate 120 so that the electrode 140 comes into contact with the first plate member 132. Alternatively, the thickness of the electrode 140 may be made greater than the depth of the electrode holding portion 124 so that the electrode 140 comes into contact with the first plate member 132.

[0046] As described above, the electrode 140 is fixed by being sandwiched between the electrode holding part 124 and the first plate member 132, but it is desirable to form a slip prevention mechanism to prevent the electrode 140 from moving outward in the first direction. For example, in the examples of Figures 9 and 10, the electrode holding part 124 may lock the end 145, which is formed to be wide, to prevent the electrode 140 from slipping outward in the first direction.

[0047] The above-described case 180 can also be used to prevent the electrode 140 from slipping outward in the first direction. For example, as shown in FIG. 11 , the end 145 of the electrode 140 in the first direction is bent in the second direction so that the end 145 faces the heat dissipation fin 130. More specifically, the end 145 of the electrode 140 faces the end surface 1320 of the first plate member 132, which is formed in an L-shape. Then, as shown in FIGS. 12 and 13 , the case 180 is formed with a locking wall 181 that abuts the end 145 and a through-hole 182 through which the electrode 140 passes.

[0048] As shown in FIG. 14 , when the case 180 is moved in a first direction toward the inside of the heater unit 150 with the electrode 140 inserted through the through-hole 182, the end 145 of the electrode 140 is pressed in the first direction by the locking wall 181. This pressing causes the end 145 of the electrode 140 to contact the end surface 1320 of the first plate member 132 of the heat dissipation fin 130. As shown in FIG. 12 , the case 180 has a locking hole 188. As shown in FIG. 15 , the protrusion 165 formed by stamping on the frame 160 is engaged with the locking hole 188 by a snap fit 185. Therefore, in this contact state, the outward movement of the electrode 140 in the first direction is prevented by the locking wall 181, preventing the electrode 140 from coming loose in the first direction. The case 180 and the frame 160 may be fastened together by bolts instead of or in addition to the snap fit 185.

[0049] 12 and 14, the case 180 is also formed with a first connector portion 183 and a second connector portion 184. The positive electrode 142 (first positive electrode 1420 and second positive electrode 1421) and the negative electrode 141 (first negative electrode 1410) are arranged in the first connector portion 183. On the other hand, the positive electrode 142 (third positive electrode 1422) and the negative electrode 141 (second negative electrode 1411) are arranged in the second connector portion 184. In this state, the positive electrode 142 and the negative electrode 141 are fitted with each other as paired electrodes. Fitting the paired electrodes in the first connector portion 183 and the second connector portion 184 also helps prevent the positive electrode 142 and the negative electrode 141 from coming loose.

[0050] 15, a second case 189 is also disposed on the opposite side of the heater unit 150 from the case 180 in the first direction. This second case 189 is also made of polybutylene terephthalate (PBT) and houses the spring 170. Like the case 180, it has a locking hole 188 that is snap-fitted to the protrusion 165 of the frame 160.

[0051] Furthermore, while the above example is a desirable response of the present disclosure, the present disclosure can be modified in various ways. The above-described materials and sizes are merely examples and can be modified according to the required performance, etc. The number and arrangement of the heat generating elements 110 within the holding plate 120 can also be modified in various ways. Furthermore, the number of holding plates 120 and heat dissipation fins 130 can also be modified. Furthermore, in the above example, the left and right springs 170 have the same shape, but it is also possible to configure one side of the spring 170 integrally with the frame 160. [Explanation of symbols]

[0052] 100 Electric heater 110 Heating element 120 Retaining Plate 130 Heat dissipation fin 140 electrodes 141 positive electrode 142 negative electrode 150 heater section 160 frames 170 Spring 180 cases

Claims

1. a flat heating element that generates heat when energized; a holding plate made of a non-conductive material that holds a plurality of heating elements in a first direction, which is a direction of a flat plate surface, and exposes both surfaces of the heating elements in a second direction perpendicular to the first direction; a heat dissipation fin made of a conductive material that is disposed in the air passage and that transfers heat from the heat generating element to the air passage and that is in contact with the heat generating element in the second direction; a positive electrode and a negative electrode connected to a power source; a pair of frames disposed on both outer sides of the heat dissipation fins and the holding plate in the second direction and sandwiching the heat dissipation fins and the holding plate; a pair of springs arranged on both outer sides of the heat dissipation fins and the holding plate in the first direction and pressing the frame inward in the second direction; The heat dissipation fin is formed by sandwiching a fin member between a first plate member and a second plate member, the positive electrode and the negative electrode contact the first plate member of the heat dissipation fin and the holding plate at positions outside in the first direction from positions at which the heat dissipation fin contacts the heat generating element, one of both surfaces of the heat generating element is electrically connected to the first plate member of the heat dissipation fin, and the other of both surfaces of the heat generating element is electrically connected to the second plate member of the adjacent heat dissipation fin; the first plate member of the heat dissipation fin and the second plate member of the adjacent heat dissipation fin are electrically insulated from each other by the holding plate; Electric heater.

2. A flat heating element that generates heat when energized; a holding plate made of a non-conductive material that holds a plurality of heating elements in a first direction, which is a direction of a flat plate surface, and exposes both surfaces of the heating elements in a second direction perpendicular to the first direction; a heat dissipation fin made of a conductive material that is disposed in the air passage and that transfers heat from the heat generating element to the air passage and that is in contact with the heat generating element in the second direction; a positive electrode and a negative electrode connected to a power source; a pair of frames disposed on both outer sides of the heat dissipation fins and the holding plate in the second direction and sandwiching the heat dissipation fins and the holding plate; a pair of springs arranged on both outer sides of the heat dissipation fins and the holding plate in the first direction and pressing the frame inward in the second direction; the positive electrode and the negative electrode are in contact with the heat dissipation fin and the holding plate at positions outside the positions where the heat dissipation fin and the heat generating element are in contact with each other in the first direction; the positive electrode and the negative electrode are in contact with the heat dissipation fins on an inner side of the spring in the first direction, The positive electrode and the negative electrode are sandwiched between the heat dissipation fin and the holding plate by their own elastic force and the elastic force of the spring. Electric heater.

3. A flat heating element that generates heat when energized; a holding plate made of a non-conductive material that holds a plurality of heating elements in a first direction, which is a direction of a flat plate surface, and exposes both surfaces of the heating elements in a second direction perpendicular to the first direction; a heat dissipation fin made of a conductive material that is disposed in the air passage and that transfers heat from the heat generating element to the air passage and that is in contact with the heat generating element in the second direction; a positive electrode and a negative electrode connected to a power source; a pair of frames disposed on both outer sides of the heat dissipation fins and the holding plate in the second direction and sandwiching the heat dissipation fins and the holding plate; a pair of springs arranged on both outer sides of the heat dissipation fins and the holding plate in the first direction and pressing the frame inward in the second direction; the positive electrode and the negative electrode are in contact with the heat dissipation fin and the holding plate at positions outside the positions where the heat dissipation fin and the heat generating element are in contact with each other in the first direction; the heat dissipation fin includes a pair of first and second plate members, and a fin member disposed between the first and second plate members; the holding plate is sandwiched between the first plate member and the second plate member of the adjacent heat dissipation fin, The positive electrode and the negative electrode are sandwiched between the first plate member and the holding plate. Electric heater.

4. A flat heating element that generates heat when energized; a holding plate made of a non-conductive material that holds a plurality of heating elements in a first direction, which is a direction of a flat plate surface, and exposes both surfaces of the heating elements in a second direction perpendicular to the first direction; a heat dissipation fin made of a conductive material that is disposed in the air passage and that transfers heat from the heat generating element to the air passage and that is in contact with the heat generating element in the second direction; a positive electrode and a negative electrode connected to a power source; a pair of frames disposed on both outer sides of the heat dissipation fins and the holding plate in the second direction and sandwiching the heat dissipation fins and the holding plate; a pair of springs arranged on both outer sides of the heat dissipation fins and the holding plate in the first direction and pressing the frame inward in the second direction; the positive electrode and the negative electrode are in contact with the heat dissipation fin and the holding plate at positions outside the positions where the heat dissipation fin and the heat generating element are in contact with each other in the first direction; a case made of a non-conductive material is disposed on the outer side of the heat dissipation fins and the holding plate in the first direction; the positive electrode and the negative electrode are in contact with the heat dissipation fins on an inner side of the case in the first direction, The positive electrode and the negative electrode are sandwiched between the heat dissipation fin and the case by their own elastic force. Electric heater.

5. a flat heating element that generates heat when energized; a holding plate made of a non-conductive material that holds a plurality of heating elements in a first direction, which is a direction of a flat plate surface, and exposes both surfaces of the heating elements in a second direction perpendicular to the first direction; a heat dissipation fin made of a conductive material that is disposed in the air passage and that transfers heat from the heat generating element to the air passage and that is in contact with the heat generating element in the second direction; a positive electrode and a negative electrode connected to a power source; a pair of frames disposed on both outer sides of the heat dissipation fins and the holding plate in the second direction and sandwiching the heat dissipation fins and the holding plate; a pair of springs arranged on both outer sides of the heat dissipation fins and the holding plate in the first direction and pressing the frame inward in the second direction; the positive electrode and the negative electrode are in contact with the heat dissipation fin and the holding plate at positions outside the positions where the heat dissipation fin and the heat generating element are in contact with each other in the first direction; the heat dissipation fins, the holding plate, the positive electrodes, and the negative electrodes are stacked in a plurality of stages in the second direction, and the positive electrodes and the negative electrodes are alternately arranged; The amount of heat generated by the heating element is controlled by changing the number of positive electrodes to which current is applied. Electric heater.

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