JP3982471B2 - Electric heater - Google Patents

Description

  The present invention relates to an electric heater that employs a positive temperature coefficient thermistor or the like as a heating element.

As shown in FIG. 14, a pair of first and second mounting frames 91 and 92 arranged substantially in parallel, and perpendicular to the first and second mounting frames 91 and 92, and the first and second mounting frames 91. , 92 are respectively held by side mounting frames 93, 94, and an electric heater 9 having a heating element 95 arranged in a plane formed by the first and second and side mounting frames 91-94 is provided. Are known.
The heating element 95 is formed by stacking heat radiation fins 951, heating elements 952, and electrode plates 953 for applying electric power to the heating elements 952 substantially parallel to each other. The first and second mounting frames 91 and 92 are substantially perpendicular to the stacking direction of the heating elements 95, and the side mounting frames 93 and 94 are approximately parallel to the stacking direction.
In the electric heater 9, the heating element 95 is laminated between the first mounting frame 91 and the upper end face of the heating element 95 and between the second mounting frame 92 and the lower end face of the heating element 95. Spring members 910 and 920 that exhibit an elastic force (restoring force) from the outside to the inside are arranged.

When the electric heater 9 is assembled, the side mounting frames 93 and 94 are moved in the first and second mounting frames 91 and 92 while pressing the heating elements 95 from the first and second mounting frames 91 and 92 so that the spring members 910 and 920 are bent. 2 It fixes to the edge part of the attachment frames 91 and 92.
Due to this fixing, the heat generating body 95 receives a compressive force in the stacking direction, and the heat dissipating fins 951, the heat generating elements 952, and the electrode plate 953 that are constituent elements of the heat generating body 95 are brought into close contact with each other by the compressive force. It is fixed in 94.

In the electric heater 9, electric power is applied from the electrode plate 953 to the heat generating element 952, and the heat generating element 952 generates heat. The heat generated in the heat generating element 952 is thermally conducted to the heat radiating fins 951 through the electrode plate 953, and heat conduction is generated from the heat radiating fins 951 to the heated medium passing through the vicinity of the heat radiating fins 951. Function.
Therefore, it is desirable that the heat dissipating fins 951, the heat generating elements 952, and the electrode plates 953 that are constituent elements of the heat generating element 95 are sufficiently in close contact with each other.
In the electric heater 9 according to FIG. 14, the spring members 910 and 920 apply a compressive force in the stacking direction to the heating element 95, thereby realizing mutual contact between the components of the heating element 95.
The following Patent Document 1 is an invention related to a radiator, but has the same configuration as that of FIG. 14 and the effect of a spring material.

Japanese Patent No. 3274234

  However, in the conventional configuration shown in FIG. 14, the role of applying a compressive force in the stacking direction to fix the heating element 95 in the mounting frames 91 to 94 and to bring the components of the heating element 95 into close contact with each other is The materials 910, 920 and the first, second, and side surface mounting frames 91-94 were in charge. However, the laminated fixing structure using these members has poor efficiency during assembly, which may cause a reduction in production efficiency. It was.

That is, the respective constituent elements are stacked to form a heating element 95, and the first and second mounting frames 91 and 92 are arranged on both end surfaces of the heating element 95 in the stacking direction, respectively, and then the first pressing means is used to make the first. And the compression force of the lamination direction is applied to the second mounting frames 91 and 92.
In order to prevent the heat generating body 95 from collapsing when a compressive force is applied, it is necessary to arrange an appropriate restraining member in the direction perpendicular to the paper surface of FIG. After such a restraining member is arranged, the side surface mounting frames 93 and 94 must be fitted to both ends of the first and second mounting frames 91 and 92. This fitting also brings the components of the heating element 95 into close contact with each other. Various operations and conditions such as bending the materials 910 and 920 to a predetermined state are necessary.

  The present invention has been made in view of such a conventional problem, and is capable of reliably fixing the first and second holding frames and the side frame, and is easy to assemble and excellent in productivity. Is to provide.

1st invention has a heat generating body comprised by laminating | stacking the heat-radiation fin, the heat generating element which heat-generates by electricity supply, and the electrode plate which applies electric power to this heat generating element, The lamination direction both end surface of this heat generating body, and this both end surface An electric heater in which a medium to be heated passes through the vicinity of the heat dissipating fin from one surface stretched by both side surfaces intersecting with each other,
The heating elements have first and second holding frames on both end surfaces in the stacking direction,
By providing a compressive force directed from the outside to the inside of the first and second holding frames, the heat dissipating fins, the heating elements, the electrode plates, and a side frame that integrates the first and second holding frames are provided. ,
The first and second holding frames are formed of a hollow body having an opening toward the side surface of the heating element,
The side frames have first and second fixing pieces that are arranged on the side surfaces of the heating elements by being inserted into the openings, respectively.
The first and second holding frames and / or the first and second fixed pieces have engaging portions that engage both,
In the engaging portion, the first holding frame and the first fixing piece are engaged with each other, and the second holding frame and the second fixing piece are engaged with each other to thereby hold the side frame with the first and second holding pieces. The electric heater is fixed to a frame.

The function and effect of the present invention will be described.
In the electric heater according to the present invention, the heating element is held between the first holding frame and the second holding frame, and a compressive force is applied from the side frame to the inside along with the first and second holding frames. The side frame is fixed by inserting the first and second fixing pieces into the openings of the first and second holding frames and engaging both at the engaging portion.

In the electric heater according to the present invention, the heating element generates heat by the power supplied from the electrode plate. Heat from the heat generating element is conducted to the heat radiating fin via the electrode plate, and is conducted from the heat radiating fin to the medium to be heated. Therefore, the larger the mutual contact area of the heating element, the electrode plate, and the radiation fin, the more efficiently heat can be transferred to the medium to be heated.
Therefore, by applying a compressive force in the stacking direction and fixing the heating element between the first and second holding frames, the heating element, the electrode plate, and the radiation fin are brought into close contact with each other, and heat conduction between these components It is possible to improve the heating efficiency of the electric heater.

The present invention uses the side frame to apply a compressive force to the first and second holding frames and the heating element therebetween, to bring the components of the heating element into close contact as described above, and to the first and second heating elements. Laminate and hold the holding frame.
Conventionally, stacking and fixing has been realized with two types of parts, but the present invention can be improved to reduce the number of parts.

  Further, according to the present invention, the assembly is completed by fixing the side frame to the place where the heating element is held by the first and second holding frames. However, in the configuration according to FIG. A spring material is disposed between the first and second mounting frames and the heating element (there is also a spring material integrated with the first and second holding frames), and compressive force is applied from the outside of the first and second holding frames. In addition, since the spring material is compressed and the side frames need to be fitted from both sides in this state, the assembling work is very troublesome. The present invention can reduce this troublesome assembly work.

  Further, the side frame inserts the first and second fixing pieces into the openings of the first and second holding frames, engages both at the engaging portion, and the side frame and the first and second frames at the engaging portion. By firmly fixing the second holding frame, it is possible to prevent the side frame from falling off the heating element.

  As mentioned above, according to this invention, while being able to fix between the 1st and 2nd holding frame and a side part frame reliably, an assembly operation is easy and it can provide the electrical heater excellent in productivity.

  The electric heater of the present invention can use a PTC (Positive Temperature Coefficient) element as a heating element. A PTC element has a property that electrical resistance rapidly increases above a specific temperature. Therefore, PTC element generates heat when energized. However, when the generated temperature exceeds a predetermined temperature, the electrical resistance becomes too high and almost no current is generated. It will not flow and will not generate heat to a certain degree of temperature. Therefore, it is possible to prevent overheating of the heater by using this element.

Next, specific shapes of the side frame and the engaging portion will be described.
That is, the first and second fixing pieces include a proximal end portion and a distal end portion extending from the proximal end portion, and are arranged along the longitudinal direction of the end surface of the heating element between the proximal end portion and the distal end portion. Having a bent portion bent in a V-shaped cross section and bent from the outside to the inside of the first and second holding frames,
It is preferable that the bent portion engages with an engaging portion provided on the first and second holding frames.

  In the configuration described here, the first and second fixed pieces are provided with bent portions, and the side frames are used by utilizing the compressive force in the heating element stacking direction that acts between the bent portions of the first and second fixed pieces. Are fixed to the first and second holding frames. Further, the bent portions engage with the engaging portions provided on the first and second holding frames, so that the first and second fixing pieces can be prevented from falling off.

If the specific example of the engaging part concerning the said structure is given, the said engaging part can be comprised from the protrusion which protruded from the inner surface of the said 1st and 2nd holding frame (Claim 3).
The engaging portion may be configured by a slit provided on the inner surface of the first and second holding frames.
In addition, the protrusion is formed from a notch provided on the projecting protrusion formed by projecting from the side opposite to the side to be projected (see FIG. 9), and the inner surfaces of the first and second holding frames. A section can be raised to form a protrusion (see FIG. 10).
The slits can be formed by punching the inner surfaces of the first and second holding frames into an appropriate shape (see FIG. 11).

In addition, the first and second fixing pieces include a base end portion and a tip end portion extending from the base end portion, and extend along the longitudinal direction of the end surface of the heating element between the base end portion and the tip end portion. Having a bent portion bent in a V-shaped cross section and bent from the outside to the inside of the first and second holding frames,
It is preferable that the engaging portion includes a protrusion provided on the first and second fixing pieces and protruding toward the inner surface of the first and second holding frames.

In this configuration, the side frames are fixed to the first and second holding frames by the engaging portions including the bent portions and the protrusions provided on the first and second fixing pieces. In this case as well, the first and second fixed pieces can be prevented from falling off.
In addition, the protrusion is formed by raising a protruding protrusion or a section surrounded by an incision as described above (see FIGS. 12 and 13).

Example 1
As shown in FIGS. 1 to 8, the electric heater 1 according to this example includes a radiation fin 32, a heating element 330 that generates heat when energized, an electrode plate 31 that applies power to the heating element 330, first and second insulations. The heating element 3 is formed by laminating the bodies 391 and 392, and is stretched by both end surfaces 301 and 302 in the stacking direction of the heating element 3 and both side surfaces 303 and 304 intersecting the both end surfaces 301 and 302. The medium to be heated passes from the surface 305 toward the other surface 306 in the vicinity of the heat radiating fins 32.

The heating element 3 has first and second holding frames 21 and 22 on both end surfaces 301 and 302 in the stacking direction, respectively, and applies a compressive force from the outside to the inside of the first and second holding frames 21 and 22. Thus, a side frame 1 is provided in which the radiating fin 32, the heat generating element 330, the electrode plate 31, and the first and second holding frames 21 and 22 are laminated and integrated.
The first and second holding frames 21, 22 are formed of hollow bodies having openings 213, 214, 223, 224 facing the side surfaces 303, 304 of the heating element 3.

The side frame 1 is inserted into the openings 213, 214, 223, and 224, respectively, so that the first and second fixing pieces 11 that arrange the side frame 1 on the side surfaces 303 and 304 of the heating element 3, Twelve.
The first and second holding frames 21 and 22 and / or the first and second fixing pieces 11 and 12 have an engaging portion that engages both, and in the engaging portion, the first holding frame 21 and the first fixing piece 11 are engaged with the second holding frame 22 and the second fixing piece 12, respectively, thereby fixing the side frame 1 to the first and second holding frames 11 and 12. To do.

  As shown in FIGS. 4 and 5, the first and second fixing pieces 11 and 12 include base end portions 111 and 121 and front end portions 113 and 123 extending from the base end portions 111 and 121, respectively. Between the base end portions 111 and 121 and the tip end portions 113 and 123, the outer side of the first and second holding frames 21 and 22 is bent in a V-shaped cross section along the longitudinal direction of the end face of the heating element 3. The bent portions 112 and 122 are bent inward from the inner side, and the bent portions 112 and 122 are engaged with the engaging portions provided on the first and second holding frames 21 and 22.

Details will be described below.
In the electric heater 2 of this example, the heat of the heat generating element 330 is conducted to the heat radiating fins 32, and when the medium to be heated (for example, air) passes from the surface 305 of the heat generating element 3 toward the surface 306, the heat radiating fins 32. Heat is received from the medium, and the temperature of the heated medium rises.
As shown in FIGS. 1 to 3, the heating element 3 includes a first insulator 391, an electrode plate 31, a radiation fin 32, a holder 33 that holds a heating element 330, an electrode plate 31, a radiation fin 32. 32 and the second insulator 392 are stacked in this order, and include four electrode plates 31, five radiating fins 32, and four holders 33 that hold four heating elements 330.
The side frames 1 are disposed on the left and right side surfaces 303 and 304 of the heating element 3, and the cases 23 and 24 are disposed from the outside of the side frames 1.
FIG. 3 is an explanatory diagram shown to show the laminated state of each component constituting the heating element, and the detailed shape of each component is omitted.

  As shown in FIGS. 1 and 2, the radiating fin 32 is composed of two L-shaped frames 321 and 322 and a thin corrugated plate 320, and is a rectangular shape surrounded by the two L-shaped frames 321 and 322. The corrugated plate 320 is accommodated in a space. The L-shaped frames 321 and 322 and the corrugated plate 320 are integrated by brazing. Here, each of the L-shaped frames 321 and 322 and the corrugated plate 320 is made of aluminum.

The heating element 330 is composed of a barium titanate ceramic semiconductor PTC element.
As shown in FIGS. 1 and 4 to 6, the holder 33 that holds the heat generating element 330 includes a main body portion 331, a side end protrusion portion 333 that protrudes from one side end of the main body portion 331, and the other side end. And a terminal protrusion 334 for guiding a connection terminal 311 provided on the electrode plate 31 described later. The widths of the side end protrusion 333 and the terminal protrusion 334 are narrower than the main body 331. The bottom surface 335 of the main body portion 331 has four holding holes 332 for holding the heating elements 300.
As shown in FIG. 6, the holder 33 has an H-shaped cross section, and both sides of the heating element 3 in the stacking direction are groove-shaped. Thereby, the heat radiating fins 32 and the electrode plates 31 adjacent to each other in the stacking direction can be held by the holder 33 so that the heat radiating fins 32 and the electrode plates 31 do not protrude in the direction of the surfaces 305 and 306.
As shown in FIGS. 1 and 2, the electrode plate 31 is made of a long and thin flat metal plate, and has a terminal portion 311 to which a female terminal 261 described later can be connected at one end portion.
The electrode plate 31 is made of brass.

As shown in FIGS. 1 to 3, the first insulator 391 insulates between the electrode plate 31 located at the extreme end of the heating element 3 and the first holding frame 21. The second insulator 392 insulates between the heat radiating fins 32 located at the extreme end of the heating element 3 and the second holding frame 22. The first insulator 391 is a groove type that can hold the electrode plate 31. The second insulator 392 is a groove type that can hold the radiation fins 32.
As shown in FIG. 1, the first and second holding frames 21, 22 are cylindrical hollow members having a square cross section, and have openings 213, 214, 223, 224 that face the side surfaces of the heating element 3. In addition, engagement holes 217, 218, 227, and 228 that engage with engagement pieces 235 and 245 of cases 23 and 24, which will be described later, are provided at both ends in the longitudinal direction.

The cases 23 and 24 are crowned from the outside of the side frame 1, and the case 23 on the left side of FIG. 1 has a rectangular side shape and includes an inner engagement piece 235 extending to the side frame 1 side. The inner engagement piece 235 engages with the left engagement holes 217 and 227 of the first and second holding frames 21 and 22.
The case 24 on the right side of FIG. 1 has a flange 241 at each end, penetrates the internal engagement piece 245 extending to the side frame 1 side, the case 24, and inserts the terminal portion 311 of the electrode plate 31. , And an insertion groove 249 for pulling it out. Further, a terminal slit 240 for inserting the female terminal 261 connected to the terminal portion 311 is provided on the outer side of the heating element 3.
In addition, the female terminal 261 is inserted, and a protective case 25 for covering and storing the female terminal 261 from outside the case 24 is provided.
The lead wire 262 extending from the female terminal 261 has sockets 263 and 264 that are connected to an external power source (not shown) of the electric heater 2.

The side frame 1 will be further described.
As shown in FIGS. 1, 7, and 8, the side frame 1 of this example has a substantially U-shaped cross section, and includes first and second fixing pieces 11 and 12 and an annular support portion 10. The first fixed piece 11 includes a proximal end portion 111, a distal end portion 113, and a bent portion 112 having a V-shaped cross section therebetween. Similarly, the second fixed piece 12 includes a base end portion 121, a tip end portion 123, and a bent portion 122 having a V-shaped cross section therebetween.
The side frame 1 is composed of SK5, which is spring steel, and the entire member functions as a spring.
The base end portions 111 and 121 extend from both ends of the support portion 10 in a gentle curve shape, and the tip end portions 113 and 123 are members that extend linearly. At the boundary between the base end portions 111 and 121 and the tip end portions 113 and 123, the first and second fixing pieces 11 and 12 are bent into a square shape to form the bent portions 112 and 122.

The assembly of the electric heater 2 of this example will be described.
As shown in FIG. 1, the heating element 330 is incorporated in the holder 33, and the first insulator 391, the electrode plate 31, the radiation fin 32, the holder 33 holding the heating element 330, the electrode plate 31, the radiation fin 32. The heat dissipating fins 32 and the second insulator 392 are stacked in this order.
At this time, the radiating fins 32 and the electrode plate 31 are held in the groove-shaped portions of the groove-shaped holder 33 and the first and second insulators 391 and 392 to stabilize the laminated state.
Next, as shown in FIGS. 8A and 8B, the bending portions 112 and 122 have a larger distance than the distance L1 between the inner surfaces 219 and 229 of the first and second holding frames 21 and 22 on the heating element 3 side. The side frame 1 is deformed so that the distance L0 is increased.

As shown in FIG. 8 (b), the first and second fixing pieces 11 and 12 of the deformed side frame 1 are opened from the side surfaces 303 and 304 of the heating element 3 to the openings of the first and second holding frames 21 and 22. 214 and 224. In the free state, the side frame 1 is (distance L0 between the bent portions 112 and 122) <(distance L1 between the inner side surfaces 219 and 229). Therefore, as shown in FIG. While the 122 is in contact with the inner side surfaces 219 and 229, a compression force inward in the stacking direction acts on the inner side surfaces 219 and 229, and the side frame 1 is fixed to the first and second holding frames 21 and 22.
Next, the cases 23 and 24 are crowned from the outside of the side frame 1, and the protective case 25 is crowned outside the case 24.
The terminal portion 311 of the electrode plate 31 is inserted into the insertion groove 249 of the case 24, and the terminal portion 311 is fixed to the female terminal 261 between the case 24 and the protective case 25.

FIG. 9 shows the engaged state between the bent portion 112 and the first holding frame 21.
The inner surface 219 of the first holding frame 21 is provided with a projecting projection 211 formed by projecting from the back side of the inner surface 219, and this projecting projection 211 is an engaging portion according to this example. As shown in FIG. 9A, the first fixing portion 11 is fixed to the first holding frame 21 by the bending portion 112 engaging with the protrusion 211.
FIG. 9B is a plan view of the inner surface 219 of the first holding frame 21. A region indicated by hatching in the figure protrudes by punching to form a launching protrusion 211.
The engagement state between the second fixed piece 12 and the second holding frame 22 and the engagement state between the side frame 1 and the first and second holding frames 21 and 22 on the side surface 303 side are the same as in FIG. It is.

The effect of this example will be described.
The electric heater 2 according to this example holds the heating element 3 between the first holding frame 21 and the second holding frame 22, and from the side frame 1, the first and second holding frames 21 and 22 together from the outside to the inside. Apply compressive force toward
The side frame 1 and the first and second holding frames 21 and 22 are fixed as follows.
That is, the first and second fixing pieces 11, 12 of the side frame 1 are inserted into the openings 213, 214, 223, 224 of the first and second holding frames 21, 22, and the first and second fixing pieces 11, By engaging 12 at the engaging portion, the side frame 1 and the first and second holding frames 21 and 22 are firmly fixed, and the side frame 1 can be prevented from falling off.

In the electric heater 2 according to this example, the heating element 330 generates heat by the power supplied from the electrode plate 31. Heat from the heat generating element 330 is conducted to the heat radiating fin 32 via the electrode plate 31, and is conducted from the heat radiating fin 32 to the medium to be heated. Therefore, the larger the mutual contact area of the heating element 330, the electrode plate 31, and the radiation fin 32, the more efficiently heat can be transferred to the medium to be heated.
In this example, the heating element 3 is fixed between the first and second holding frames 21 and 22 by applying a compressive force in the stacking direction using the side frame 1, thereby generating the heating element 330, the electrode plate 31, The heat radiation fins 32 can be brought into close contact with each other to improve the heat conduction between these components, and the heating efficiency of the electric heater 2 can be increased.
In addition, the side frame 1 of this example is made of metal, so that creep does not easily occur and rigidity during use is unlikely to occur.

  As described above, according to this example, it is possible to provide an electric heater that can securely fix the first and second holding frames and the side frames, and that is easy to assemble and excellent in productivity.

In addition, as another example of an engaging part, there exists a structure as shown in FIG. 10, FIG.
In FIG. 10, a notch 2120 is provided on the inner surface 219 of the first holding frame 21, and a section formed from the notch 2120 is raised toward the bent portion 112 to form a protrusion 212. The first fixing piece 11 is fixed to the first holding frame 21 by the protrusion 212 engaging with the bent portion 112.
In FIG. 11, a slit 216 is provided on the inner surface 219, and the bent portion 112 of the first fixing portion 11 is fitted into the slit 216, thereby fixing the first fixing piece 11 to the first holding frame 21.

(Example 2)
In the electric heater 2 according to this example, the engaging portions between the first and second fixed pieces 11 and 12 and the first and second holding frames 21 and 22 are connected to the first and second fixed pieces 11 and 12. It is provided.
That is, as shown in FIGS. 12 and 13, the engaging portion is composed of protrusions 118 and 119 protruding toward the inner surface of the first holding frame 21 (the second fixed piece 12 and the second holding frame 22. Since this is the same for, the illustration is omitted.)

FIG. 12 shows a configuration in which, as in FIG. 9 described above, a projecting protrusion 118 formed by ejecting from the back side is provided and used as an engaging portion.
FIG. 13 shows a configuration in which a notch is provided and a section formed by the notch is raised toward the inner surface to form a protrusion 119, which is used as an engaging portion, as in FIG. 10 described above.
In any configuration, the first and second fixing pieces and the first and second holding frames 21 and 22 are engaged with each other, and the side frame 1 and the first and second holding frames 21 and 22 are engaged with each other at the engaging portion. It is firmly fixed and can prevent the side frame 1 from falling off.
Other details are the same as those in the first embodiment.

FIG. 3 is a perspective development view of the electric heater according to the first embodiment. 1 is a plan view of an electric heater according to Embodiment 1. FIG. 1 is a schematic diagram of a heating element according to Example 1. FIG. Explanatory drawing of a holder and heat generating element concerning Example 1. FIG. The top view of the holder concerning Example 1. FIG. Sectional drawing of the holder concerning Example 1. FIG. The perspective view of the side part frame concerning Example 1. FIG. FIG. 3 is an explanatory diagram illustrating fixing of the side frame to the side surface of the heating element according to the first embodiment. FIG. 3 is an explanatory diagram illustrating an engaging portion between a first fixing piece of a side frame and a first holding frame according to the first embodiment. Explanatory drawing which shows the engaging part concerning the other structure between the 1st fixing piece of a side part frame and a 1st holding | maintenance frame concerning Example 1. FIG. Explanatory drawing which shows the engaging part concerning the other structure between the 1st fixing piece of a side part frame and a 1st holding | maintenance frame concerning Example 1. FIG. Explanatory drawing which shows the engaging part between the 1st fixing piece of a side frame and a 1st holding | maintenance frame concerning Example 2. FIG. Explanatory drawing which shows the engaging part between the 1st fixing piece of the other side part frame and 1st holding | maintenance frame concerning Example 2. FIG. The top view of the electric heater concerning a conventional structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Side part frame 11 1st fixed piece 12 2nd fixed piece 2 Electric heater 21 1st holding frame 22 2nd holding frame 3 Heating body 31 Electrode plate 32 Radiation fin 330 Heating element

Claims (5)

A heat-dissipating fin, a heat-generating element that generates heat when energized, and a heating element configured by laminating electrode plates that apply power to the heat-generating element, and both end surfaces in the stacking direction of the heat-generating element and both side surfaces intersecting the both end surfaces An electric heater in which a medium to be heated passes through the vicinity of the heat dissipating fin from one surface stretched by
The heating elements have first and second holding frames on both end surfaces in the stacking direction,
By providing a compressive force directed from the outside to the inside of the first and second holding frames, the heat dissipating fins, the heating elements, the electrode plates, and a side frame that integrates the first and second holding frames are provided. ,
The first and second holding frames are formed of a hollow body having an opening toward the side surface of the heating element,
The side frame has first and second fixing pieces for fixing the side frame to the side surface of the heating element by being respectively inserted into the opening.
The first and second holding frames and / or the first and second fixed pieces have engaging portions that engage both,
In the engaging portion, the first holding frame and the first fixing piece are engaged with each other, and the second holding frame and the second fixing piece are engaged with each other to thereby hold the side frame with the first and second holding pieces. An electric heater characterized by being fixed to a frame. In Claim 1, The said 1st and 2nd fixing piece consists of a base end part and the front-end | tip part extended from this base end part, Between the said base end part and the said front-end | tip part, the end surface length of the said heat generating body is long. A bent portion bent in a V-shaped cross section along the direction and bent from the outside to the inside of the first and second holding frames;
The electric heater, wherein the bent portion engages with an engaging portion provided in the first and second holding frames.   The electric heater according to claim 2, wherein the engaging portion includes a protrusion protruding from an inner surface of the first and second holding frames.   3. The electric heater according to claim 2, wherein the engaging portion includes a slit provided on an inner surface of the first and second holding frames. In Claim 1, The said 1st and 2nd fixing piece consists of a base end part and the front-end | tip part extended from this base end part, Between the said base end part and the said front-end | tip part, the end surface length of the said heat generating body is long. A bent portion bent in a V-shaped cross section along the direction and bent from the outside to the inside of the first and second holding frames;
The electric heater according to claim 1, wherein the engaging portion includes a protrusion provided on the first and second fixing pieces and protruding toward the inner surface of the first and second holding frames.

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