JP2007292425A - Electric heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the number of components in an electric heater 20 having a PTC (positive temperature coefficient) element. <P>SOLUTION: The electric heater 20 is constituted to hold a laminated part 20A by a U-shaped frame 90 from the upper and lower directions and to insert and hold the ends of the laminated part 20A and U-shaped frame 90 into a housing 80. The electric heater 20 is thereby composed of only the U-shaped frame 90 and the housing 80 except the laminated part 20A. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electric heater having a PTC element.

  Conventionally, this type of electric heater includes a laminated portion, first and second frames, first and second spring members, and first and second housings (see, for example, Patent Document 1). ).

  In this structure, the stacked portion includes a plurality of heat radiation fins stacked in the vertical direction and a plurality of heater plates disposed between any two heat radiation fins among the plurality of heat radiation fins. Each of the plurality of heater plates has a PTC (positive temperature coefficient) element and is formed in a long plate shape, and heats adjacent radiating fins.

  The first frame is disposed on the upper side with respect to the stacked portion, and the second frame is disposed on the lower side with respect to the stacked portion. The first spring member is disposed between the first frame and the laminated portion, presses the laminated portion downward by elastic force, and the second spring member includes the second frame and the laminated portion. It is arrange | positioned between these and the laminated part is pressed to the upper side with the elastic force.

In the first housing, left end portions of the first and second frames and the laminated portion are fitted, respectively, and the first and second frames and the laminated portion are placed in the second housing. The right end of each part is inserted.
US Pat. No. 5,057,672

  The above-mentioned electric heater requires a large number of members such as the first and second frames, the first and second spring members, and the first and second housings in addition to the stacked portion, which increases the cost. It was.

  In view of the above points, an object of the present invention is to provide an electric heater in which the number of parts is reduced.

  In order to achieve the above object, the present invention includes a spring member (90) that sandwiches and holds the laminated portion (20A) from the first direction by elastic deformation, and the spring member includes the air flow direction and the first of the laminated portions. An opening (80f) that is formed so as to cover one end portion in the second direction intersecting with each of the first direction, and in which the other end portion in the second direction of the stacked portion and the spring member is fitted. ).

  Therefore, since the electric heater can be configured by using only one spring member and one housing in addition to the laminated portion, the number of components can be reduced as compared with the conventional technique.

  In addition, the code | symbol in the bracket | parenthesis of each means described in a claim and this column shows the correspondence with the specific means as described in embodiment mentioned later.

  FIG. 1 shows an interior air conditioning unit 1 of a vehicle interior air conditioner to which an electric heater according to the present invention is applied. FIG. 1 is a schematic cross-sectional view of an indoor air conditioning unit 1 of the present embodiment.

  The indoor air conditioning unit 1 is disposed inside the instrument panel (instrument panel) at the forefront of the vehicle interior, and the indoor air conditioning unit 1 has an air conditioning casing 2 made of resin. An air passage through which air flows toward the vehicle interior is formed inside the air conditioning casing 2, and an inside / outside air switching box 3 is arranged at the most upstream part of the air flow.

  The inside / outside air switching box 3 includes an inside air introduction port 4, an outside air introduction port 5, and an inside / outside air switching door 6. The inside air introduction port 4 is an introduction port for introducing inside air (vehicle compartment air) into the air conditioning casing 2, and the outside air introduction port 5 is an introduction port for introducing outside air (vehicle compartment outside air) into the air conditioning casing 2. The inside / outside air switching door 6 is rotatably supported inside the inside / outside air switching box 5, and the inside / outside air switching door 6 is driven by a servo motor.

  On the downstream side of the air flow in the inside / outside air switching box 5, an electric blower 7 that blows air toward the passenger compartment is disposed. The blower 7 rotates the centrifugal multiblade fan 7a by an electric motor 7b and blows air in the arrow A direction. On the downstream side of the air flow of the blower 7, an evaporator 8 that is a cooling heat exchanger for cooling the blown air is disposed.

  The evaporator 8 is one of the elements constituting the refrigeration cycle apparatus. As is well known, the evaporator 8 absorbs heat from the blown air blown by the blower 7 when the low-pressure refrigerant flowing into the evaporator 8 evaporates, and blows the blown air. It is to be cooled. On the downstream side of the evaporator 8, a heater core 9 for heating the air (cold air) after passing through the evaporator 8 is arranged.

  The heater core 9 is a heat exchanger for heating that heats air (cold air) that has passed through the evaporator 8 using engine coolant as a heat source. Further, a bypass passage 10 through which air (cold air) after passing through the evaporator 8 bypasses the heater core 9 and passes through the heater core 9 inside the air conditioning casing 2 is formed.

  Moreover, the electric heater 20 is arrange | positioned in the downstream of the heater core 9, and the electric heater 20 is an auxiliary heater which heats the air which passed the heater core 9 at the time of heating operation. The specific structure of the electric heater 20 will be described later.

  An air mix door 11 is disposed between the evaporator 8 and the heater core 9, and the air mix door 11 is rotatably disposed in the air conditioning casing 2. The air mix door 11 is a servo. Driven by a motor, the rotational position (that is, the opening) can be continuously adjusted.

  As a result, the air mix door 11 has an air volume ratio between the amount of air passing through the heater core 9 and the electric heater 20 (the amount of hot air indicated by arrow B) and the amount of air passing through the bypass passage 10 (the amount of cold air indicated by arrow C). By adjusting the air temperature, the temperature of the air blown into the passenger compartment is adjusted.

  Moreover, in the most downstream part of the air path of the air-conditioning casing 2, the defroster opening part 12 for blowing an air-conditioning wind toward the front window glass of a vehicle, and the face opening part for blowing an air-conditioning wind toward a passenger | crew's face part 13 and a foot opening 14 for blowing conditioned air toward the passenger's feet. A defroster door 15, a face door 16 and a foot door 17 are rotatably arranged at upstream portions of the openings 12 to 14, and these doors 15 to 17 are opened and closed by a common servo motor via a link mechanism. Is done.

  Next, the structure of the electric heater 20 of this embodiment will be described. FIG. 2 is a front view of the electric heater 20 according to the present embodiment as viewed from the air flow direction, and FIG. 3 is a view taken along the arrow X in FIG. In FIG. 2, up, down, left and right arrows indicate directions in the mounted state.

  The electric heater 20 includes a laminated portion 20A. As shown in FIGS. 2 and 3, the laminated portion 20A includes radiating fins 30, 31, 32, 33, 34, electrode plates 40, 41, 42, 43, 44 and heater plates 50, 51, 52 and 53.

  The radiating fins 30 to 34 are corrugated fins each formed in a wave shape, and the radiating fins 30 to 34 are arranged so that each mountain portion 30a faces in the vertical direction and the fin pitch is in the horizontal direction. ing. The up-down direction is a direction perpendicular to the air flow direction (the direction perpendicular to the paper surface) and corresponds to the first direction recited in the claims.

  As shown in FIG. 4, the heater plate 50 includes a long plate-like resin frame 50 b having a plurality of openings, and PTC elements 50 a respectively inserted into the plurality of openings, and an element row of the PTC 50 c elements is formed. It is composed. The PTC element 50a is a known element having a characteristic that the resistance value increases when the temperature reaches the Curie point, and the current increases and stabilizes at a constant temperature when the temperature decreases while a voltage is applied. Each of the heater plates 51 to 53 has the same structure as the heater plate 50.

  The heater plate 50 is disposed between the radiation fins 30 and 31, and the heater plate 51 is disposed between the radiation fins 31 and 32. The heater plate 52 is disposed between the radiation fins 32 and 33, and the heater plate 53 is disposed between the radiation fins 33 and 34.

  A conductive plate 60a is provided between the heater plate 50 and the heat radiation fin 30, and the conductive plate 60a is a thin plate member made of a metal material such as aluminum having conductivity and heat conductivity. The conductive plate 60a is arranged in parallel to the air flow direction and so as to extend in the left-right direction. The conductive plate 60a is in contact with the heater plate 50 and is joined to each peak 30b on the lower side of the radiating fin 30 by brazing or the like.

  A conduction plate 60b is provided between the heater plate 51 and the heat radiation fin 31, and the conduction plate 60b is arranged so as to extend in the left-right direction in parallel with the air flow direction. The conductive plate 60b is in contact with the heater plate 51 and is joined to each peak 30b on the lower side of the radiating fin 31 by brazing or the like. In addition, in the radiation fins 31-34, the code | symbol of each peak part is abbreviate | omitted.

  A conduction plate 60c is provided between the heater plate 52 and the heat radiating fins 32, and the conduction plate 60c is arranged to extend in the left-right direction in parallel with the air flow direction. The conductive plate 60c is in contact with the heater plate 52, and is joined to each peak 30b below the radiating fin 32 by brazing or the like.

  A conduction plate 60d is provided between the heater plate 53 and the heat radiating fins 33, and the conduction plate 60d is arranged so as to extend in the left-right direction in parallel with the air flow direction. The conductive plate 60d is in contact with the heater plate 53 and joined to each peak 30b on the lower side of the heat radiation fin 33 by brazing or the like.

  A conduction plate 60e is provided below the heat radiating fins 34, and the conduction plate 60e is arranged so as to extend in the left-right direction in parallel with the air flow direction. The conductive plate 60e is joined to each peak part 30b below the radiating fin 34 by brazing or the like.

  The conductive plates 60b, 60c, and 60d are thin plate members made of a metal material such as aluminum having conductivity and heat conductivity. The conductive plate 60e is made of a thin plate member made of a metal material such as aluminum having conductivity and heat conductivity, and an electrically insulating material formed along the lower surface (or upper surface) of the thin plate member. A thin film.

  The electrode plates 40, 41, 42, 43, 44 are long plate members made of a metal such as brass having conductivity and heat conductivity, and parallel to the air flow direction and in the left-right direction. It is arranged to extend to.

  The electrode plate 40 is disposed on the upper side of the radiation fin 30, and the electrode plate 41 is disposed between the radiation fin 31 and the heater plate 50. The electrode plate 42 is disposed between the radiation fin 32 and the heater plate 51, and the electrode plate 43 is disposed between the radiation fin 33 and the heater plate 52. The electrode plate 44 is disposed between the heat radiating fins 34 and the heater plate 53.

  As shown in FIG. 2, the electric heater 20 includes a housing 80 and a U-shaped frame 90. The U-shaped frame 90 is a spring member, and is formed by extending a thin metal plate formed in parallel with the air flow direction into a U-shape. The U-shaped frame 90 is disposed so as to cover the upper end, the lower end, and the right end of the thin plate stacking portion 20A, and a plurality of protrusions 91 (four protrusions 91 in FIG. 2) are stacked in the thin plate. In a state where the upper end portion and the lower end portion of the portion 20A are in contact with each other, the thin plate stacking portion 20A is sandwiched and held by the elastic force from the vertical direction. Here, since the U-shaped frame 90 is disposed so as to cover the right end portion of the thin plate stack portion 20A, the right end portion of the thin plate stack portion 20A is protected.

  The housing 80 is made of a resin material and is formed in a box shape. The housing 80 is disposed on the left side with respect to the stacked portion 20A. As shown in FIG. 5, the housing 80 has an opening 80f. As shown in FIG. 3, the left end of the laminated portion 20A and the U-shaped frame 90 is inserted into the opening 80f of the housing 80. The housing 80 is connected to the upper end 80b and the lower end 80c. The U-shaped frame 90 and the laminated portion 20 </ b> A are held by sandwiching the left end portion of the character-shaped frame 90 from above and below. In addition, the code | symbol 80e in FIG. 5 is a screw hole.

  In addition, in the housing 80 in FIG. 2, each left end part (electrode terminal) of the electrode plates 40 to 43 is connected to an electric wire via a connection terminal, respectively. Omitted.

  Next, the manufacturing method of the electric heater 20 will be described. First, the stacked portion 20A, the housing 80, and the U-shaped frame 90 are prepared, and the U-shaped frame 90 is disposed so as to cover the upper end, the lower end, and the right end of the stacked portion 20A. The laminated portion 20A is sandwiched from above and below by the character frame 90. Thereafter, the U-shaped frame 90 and the left end of the laminated portion 20 </ b> A are inserted into the housing 80.

  Next, the operation of the electric heater 20 of this embodiment will be described. FIG. 6 shows an electric circuit configuration of the electric heater 20.

  When a positive voltage is applied to each of the electrodes 40, 42, and 44 and a negative voltage is applied to each of the electrodes 41 and 43, a current flows from the electrode 40 to the electrode 41 through the heater plate 50, the conductive plate 60 a, and the heat radiation fin 30. A current flows from the electrode 42 to the electrode 41 through the radiation fin 31, the conductive plate 60 b and the heater plate 51. A current flows from the electrode 42 to the electrode 43 through the heater plate 52, the radiation fin 32, the conduction plate 60 c and the like. Further, a current flows from the electrode 44 to the electrode 43 through the heater plate 53, the conduction plate 60 d, and the heat radiation fin 33.

  As described above, a current flows through each PTC element 50a of the heater plates 50 to 53, each PTC element 50a generates heat, and the heat generated from the PTC element 50a passes to the heat dissipating fins (30 to 34) adjacent to each other through the conductive plate. introduce. For this reason, the radiation fins 30 to 34 can heat the passing air.

  According to the present embodiment described above, the electric heater 20 holds the stacked portion 20A by sandwiching the stacked portion 20A from above and below with the U-shaped frame 90, and the ends of the stacked portion 20A and the U-shaped frame 90 are inside the housing 80. It has been inserted into.

  Therefore, the electric heater 20 is configured using only one U-shaped frame 90 and one housing 80 in addition to the stacked portion 20A. For this reason, the number of parts can be reduced compared with the prior art.

  Moreover, since one housing 80 can be reduced compared with a prior art, a pressure loss can be reduced.

  In the above-described embodiment, the following configuration may be added in order to make it difficult to remove the U-shaped frame 90 from the housing 80. That is, an upper protrusion that protrudes upward is provided at the upper end of the U-shaped frame 90, and a lower protrusion that protrudes downward is provided at the lower end of the U-shaped frame 90. Furthermore, an upper recess and a lower recess into which the upper protrusion and the lower protrusion enter respectively are provided in the housing 80. Therefore, since the upper and lower protrusions of the U-shaped frame 90 are engaged with the upper and lower recesses in the housing 80, the U-shaped frame 90 is not easily removed from the housing 80. be able to.

 In the above-described embodiment, an example using four radiating fins has been described. However, the present invention is not limited to this, and any number of radiating fins may be used as long as there are two or more.

 In the above-described embodiment, the example in which the electric heater of the present invention is applied to a vehicle air conditioner has been described. However, the present invention is not limited thereto, and may be applied to a stationary air conditioner.

It is a figure which shows the structure of the vehicle air conditioner to which the electric heater of this invention was applied. It is a front view of the electric heater of FIG. It is a side view of the laminated part of FIG. It is a perspective view of the electric heater of FIG. It is a figure which shows the housing of FIG. It is a circuit diagram which shows the electrical structure of the electric heater of FIG.

Explanation of symbols

20 ... Electric heater, 30-34 ... Radiation fin,
40-44 ... Electrode plate, 50-53 ... Heater plate,
60a-60e ... conductive plate,
80 ... housing, 90 ... U-shaped frame.

Claims (4)

A plurality of radiation fins (30 to 34) stacked in a first direction intersecting with the air flow direction, and any one of the plurality of radiation fins in the first direction. PTC elements (50 to 53) that are arranged to heat the plurality of heat radiation fins, and are arranged so as to sandwich the PTC element from the first direction, and first and second for applying a voltage to the PTC element A laminated portion (20A) having a plurality of electrodes (40 to 44);
An electric heater comprising: a spring member (90) that holds the stacked portion sandwiched from the first direction by elastic deformation;
The spring member is formed so as to cover one side end portion in the second direction intersecting each of the air flow direction and the first direction in the laminated portion,
An electric heater comprising: a housing (80) having an opening (80f) into which the other end of the second direction in the stacked portion and the spring member is fitted. 2. The spring member is formed in a U shape so as to cover both side end portions in the first direction and one side end portion in the second direction of the stacked portion. The electric heater according to 1. The electric heater according to claim 2, wherein the spring member is formed so as to extend a thin plate member formed in parallel to the air flow direction in the U-shape. . The electric heater according to claim 2, wherein the spring member is formed so as to extend a linear member in the U-shape.

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