JP2685170B2 - Heating equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heating device. [Prior Art] Conventional heating devices of this type include, for example, Japanese Patent Laid-Open No. 56-160.
Some are described in Japanese Patent No. 786. This is a combination of a plate-shaped ceramic heating element having a positive resistance temperature coefficient and a heat radiation block having a passage portion, which are thermally coupled and integrated, and the integrated heat radiation portion is made of metal. The structure is fixed inside a frame-shaped housing. [Problems to be Solved by the Invention] However, according to the above-mentioned conventional example, there is no disclosure regarding the fixing structure of the heat radiating portion and the housing. According to the present invention, when fixing a heat radiating portion, which is a combination of a plurality of heat generating elements and a plurality of heat radiating blocks, to a housing, the heat generating elements and the heat radiating blocks are surely pressed and fixed, and the plurality of heat generating elements and heat radiating blocks are generated. An object of the present invention is to provide a heating device capable of preventing the falling of the metal. [Means for Solving the Invention] Therefore, in view of the above points, the present invention has a plurality of plate-shaped heating elements that are arranged in parallel with each other and generate heat by energization,
Disposed at least between the parallel arrangements of the plurality of heating elements,
Further, a substantially quadrangular radiating portion consisting of a plurality of radiating blocks having a passage portion through which the medium to be heated is passed, and the plurality of platy members extending in a direction intersecting the parallel direction of the platy heating element. A plurality of vertical frame portions facing each other in a manner of traversing the heating element and the plurality of heat dissipation blocks, and a plurality of horizontal frame portions facing each other connecting the vertical frame portions,
At least a part of the plurality of horizontal frame portions is provided with a side wall surface having an L-shaped cross-section, and the vertical frame portion and the horizontal frame portion are exposed so that a part of the heat dissipation portion is exposed. The heat dissipation portion is provided by providing a substantially rectangular frame portion having a through opening having an opening area smaller than that of the heat dissipation portion surrounded by a portion and a support portion supporting the heat dissipation portion at one end. No smaller opening area,
A frame-shaped and substantially rectangular housing in which the other end is provided with a through opening having an opening area larger than that of the heat dissipation portion;
Through the side wall surface of the frame portion arranged on the other end side of the through opening portion of the housing, the heat radiation portion is pressed in one direction intersecting the parallel direction of the heat generating body to move the frame body to the housing. And a fixing means for holding the heat dissipation portion between the frame portion and the support portion of the housing by being fixed to the. [Operations and Effects of the Invention] In the present invention, as described above, the plurality of plate-shaped heating elements and the plurality of plate-shaped heating elements are provided via the side wall surfaces provided on at least a part of the plurality of horizontal frame portions facing each other of the frame portion. The frame block is fixed to the housing by pressing the heat dissipation block in a direction that intersects the parallel direction of the heating element, and the fixing part fixes the heat dissipation part between the frame part and the support part of the housing. be able to. At this time, thermal contact with the heating element and the plurality of heat radiation blocks can be secured at the same time. Further, the frame body is fixed to the housing by pressing from one direction intersecting the parallel direction of the heat generating body, and the plate-shaped heat generating body and the plurality of plate-shaped heat generating bodies are provided between the frame body fixed to the housing and the support portion of the housing. Since it holds the heat dissipation part consisting of a heat dissipation block, even if it receives external vibration,
It is possible to prevent the resonance of the heat radiating portion, and therefore to prevent deformation of the heating element and the heat radiating block due to the resonance. Further, since the through opening surrounded by the horizontal frame part and the vertical frame part of the frame part has an opening area smaller than that of the heat dissipation part, a plurality of heating elements and a plurality of heat dissipation blocks are provided from the frame part. It is possible to securely hold the combined heat radiation portion in the housing. [Examples] The present invention will be described in detail below based on examples shown in the drawings. 1 (a) is a front view showing the structure of an intake air heating device for a diesel engine according to an embodiment of the present invention, and FIG. 1 (b) is a sectional view taken along the line AA in FIG. 1 (a). (C) is a BB sectional view of FIG. 1 (a). In these figures, 1
Is 4 PTC elements formed in a rectangular flat plate with a thickness of 2 mm.
Two sheets are arranged in parallel with each other as one set. The PT
The C element 1 generates heat when energized, and is made of a material having a positive temperature resistance coefficient such that the electric resistance of the barium titanate (BaTiO ₃ ) ceramic sintered body increases remarkably as the temperature rises. . Reference numeral 2 is a heat dissipation block having a rectangular shape in a plane, and includes the above plurality of PTCs.
Arranged between the parallel arrangements of the elements 1, the heat dissipation block 2 is
A meandering radiation fin 2a made of copper or aluminum,
The radiating fin 2a is composed of a flat plate-shaped plate 2b made of copper or aluminum that is soldered to the bent ends on both sides. With this solder joint, the heat dissipation block is PT
It will be thermally coupled to the C element 1. A passage is formed between the meandering portions of the heat radiating fins 2a of the heat radiating block 2 for allowing intake air as a medium to be heated to pass therethrough. As shown in FIG. 1 (c), a louver 2'a cut and raised in a direction perpendicular to the intake air flow direction A is provided on the surface of the heat dissipation fin 2a of the heat dissipation block 2.
The heat transfer area is increased. The heat dissipation blocks 2 are arranged in three rows, and the PTC elements 1 are arranged on both sides of the three rows arrangement. Further, one row of heat dissipation blocks 2 are arranged on both outer sides of the PTC element 1. It should be noted that it is positioned between the PTC element 1 and the plate 2b of the heat dissipation block 2 arranged on both outer sides of the PTC element 1,
Graphite filler layer, which is a thermally and electrically conductive elastic body
1a is formed on the surface of the PTC element 1 by baking (see FIG. 4). Here, as is apparent from FIG. 1 (a), three rows of inner heat dissipation blocks 2 arranged between two PTC elements 1 facing each other, and one row of outer heat dissipation blocks on the opposite side of the PTC elements 1. Regarding the relationship of the passage opening area with respect to 2, the total opening area of the plurality of passage portions of the inner heat dissipation block 2 is set to be larger than the total opening area of the plurality of passage portions of each outer heat dissipation block 2. This can be understood from FIG. 1 (a),
The radiating fins 2a of the inner radiating block 2 and the outer radiating block 2 have substantially the same bending width dimension, and the cumulative radiating width of the radiating fins 2a of the inner radiating block 2 is the bending width of the radiating fins 2a of the outer radiating block 2. This is because the size is set larger than that. Incidentally, the cumulative bending width of the heat dissipation fins 2a of the inner heat dissipation block 2 is the outer heat dissipation block 2
It is about three times the bending width of the radiation fin 2a. 3 is a case made of heat-resistant resin such as PPS or ceramic. As shown in FIGS. 1 (b) and 1 (c), the case 3 includes a lower case 3a, which is a lower frame portion having a shape obtained by removing one side surface of a box having a planar rectangular shape, and a frame portion. It has a box-like shape in which at least a part of the lateral frame portion is combined with a cover 3b provided with side surfaces 3'b which are side wall surfaces so that the cross-sectional shape is L-shaped. Further, in the case 3, a plane parallel to the paper surface in FIG. 1A extends in a direction intersecting the parallel arrangement direction of the PTC element 1 and just crosses the PTC element 1 and the heat radiation block 2. , A plurality of vertical frame portions facing each other, and three vertical frame portions in this embodiment, and a plurality of horizontal frame portions facing each other that connect just both ends of the vertical frame portion, two horizontal frame portions in the present embodiment, It has a substantially quadrangular frame shape having a through opening 3a surrounded by a portion and a vertical frame portion. The through opening 3c has an opening area smaller than that of the heat radiating portion composed of the PTC element 1 and the heat radiating block 2, and opens the passage portion formed in the heat radiating block 2. The heat radiating portion has a substantially rectangular shape in plan view, as is clear from FIG. 1 (a). 4 is an aluminum housing with a through opening
It has a substantially rectangular and frame-like shape with 4c. The case 3 is housed inside the housing 4, and a restoring force in the expanding direction is provided in the space 4b formed between the one side surface 4a of the housing 4 and the side surface 3'b of the cover 3b of the case 3. A U-shaped spring 5 as a fixing means for fixing the provided housing 4 and the case 3 (frame portion) is arranged. Due to the restoring force of the spring 5, the side surface 3'b of the case 3b which is the frame body
The PTC element 1 and the heat radiating block 2 are pressed together via the to fix the case 3b to the housing 4. Further, the end surface 3'a of the lower case 3a facing the side surface 3'b of the case 3b is also pressed through the PTC element 1 and the heat dissipation block 2, so that the lower case 3b is also fixed to the housing 4. It will be. Then, the case 3b and the lower case 3a are fixed to the housing 4 by the restoring force of these springs 5,
The PTC element 1 and the heat dissipation block 2 are also held in the case 3b and the lower case 3a. Further, at this time, since the through opening 3c surrounded by the horizontal frame portion and the vertical frame portion of the case 3b has an opening area smaller than that of the heat dissipation portion, the horizontal frame portion 3b 'and the vertical frame portion (Including the vertical frame portion at the center in FIG. 1A) prevents the plurality of PTC elements 1 and the plurality of heat dissipation blocks 2 from slipping out. Furthermore, since the heat dissipation portion is pressed from one direction intersecting the parallel direction of the PTC element 1 and held between the cover 3 and the housing support portion 4e, resonance of the heat dissipation portion due to external vibration is prevented. doing. The positive side terminal 2c is pulled out from one of the heat transfer plates 2b in the inner heat dissipation block 2 arranged in the above three rows through a not-shown notch in the lower case 3a. The terminal 2c is bent along the side surface of the frame portion 3d of the lower case 3a,
The terminal 2c is electrically insulated and fixed to the housing 4 at the bent portion by the bolt 6a and the nut 6b via the frame portion 3d and the insulator ring 6c. As a result, the lower case 3a is fixed to the housing 4 via the frame portion 3d. Further, from the outermost heat transfer plate 2b of the outer heat radiating block 2 arranged in one row, the negative side terminals 2d located in the opposite direction to the terminal 2c are drawn out to the outside of the lower case 3a. The terminal 2d is a shelf 3e of the lower case 3a.
It is placed on the top, fixed to the housing 4 via machine screws 7, and electrically connected to the housing 4. Reference numeral 8 denotes a clip as a fixing means for fixing the cover 3b to the housing 4, and the clip 8 has a convex portion 3f of the upper case 3b as is apparent from FIGS. 1 (a) and 1 (c). The convex portion 3f is fitted from above on the supporting portion 4d of the housing 4 in a mounted state. The case 8 is fixed by the clip 8 so as to be movable only in the paper surface direction, which is the pressing direction in FIG. 1 (a). By fixing the cover 3b to the housing 4 in this manner, the heat radiating portion is held between the support portion 4e of the housing 4 and the cover 3b. As a result, the heat radiating portion is heated by the medium to be heated. It moves in the passing direction so as not to fall off the housing 4. Therefore, the cover 3b forms a part of the frame portion that restricts the movement of the heat dissipation portion. FIG. 3 shows a state in which the intake air heating device 10 having the above structure is attached to the intake system of a diesel engine. The housing 4 of the heating device 10 is in a state in which the heat radiating portion of the heating device 10 crosses the intake manifold portion 13 between the engine 11 and the air cleaner 12, that is, the intake flow direction is the direction of arrow A in FIG. 1 (c). It is attached so as to match with and is configured to heat the intake air. In the figure, 14 is an engine piston, 15 is a cylinder chamber, 16 is an intake / exhaust valve, and 17 is a fuel injection nozzle. Next, the operation will be described. The current supplied from the battery (not shown) enters the positive side terminal 2c, flows through the inner heat dissipation block 2 in the PTC element 1 in the thickness direction, and passes through the outer heat dissipation block 2 and the negative side terminal 2d.
And is grounded to the housing 4 via the small screw 7. An electric current flows through the above path to generate heat in the PTC element 1, and this heat is conducted to the heat dissipation block 2. On the other hand, the intake air flows through the passage portion formed between the radiation fins 2a and receives heat to be warmed. Here, since the present embodiment has the above-mentioned configuration, it has the operation described below. That is, since the heat radiating portion is fixed to the metal housing 4 through the case 3 made of heat resistant resin or ceramic, it is possible to block the heat of the heat radiating portion from being transferred to the housing 4, so that the heat radiating portion can be blocked. It becomes possible to effectively transfer the heat of to the intake air. Terminal provided on the heat dissipation block 2 inside the heat dissipation unit
Since the free end of 2c is bent into a substantially U shape along the inner wall of the housing 4 and the free end is fixed to the inner wall of the housing 4,
Due to the bent shape of the terminal 2c, a spring property can be imparted to the terminal 2c, the terminal 2c can be reliably fixed to the housing 4, and the heat dissipation portion can be held in the housing 4 due to the spring property. Since the total opening area of the plurality of passage portions of the inner heat dissipation block 2 is set to be larger than the total opening area of the plurality of passage portions of the outer heat dissipation block 2, the amount of intake air passing through the passage portion of the inner heat dissipation block 2 is set. Will increase. As a result, PTC
Since the heat generated by the element 1 is effectively transmitted to the intake air through the inner heat dissipation block 2, the PTC element 1 does not reach the self-control temperature and the heat generation of the PTC element 1 is not hindered. . That is, in general, the flow rate distribution of the fluid in the passage has a mountain-like distribution in which the center of the passage increases as the center approaches the end. For this reason, in the heating device of the present embodiment, if a large amount of intake air is made to flow to the central portion of the heating portion, in other words, the inner heat radiating block 2, the inner heat radiating block 2 radiates heat efficiently, so that the PTC element 1 The heat generation efficiency of is improved. Since the heat dissipation part is held between the support part 4e of the housing 4 and the cover 3b, it is possible to prevent the heat dissipation part from jumping out from the inside of the housing 4 to the outside. FIG. 4 shows the intake air preheating characteristics before engine cranking. A conventional intake air heating device using a metal wire required a preheating time of about 14 seconds (energization time to the device before engine cranking), but in the device of this embodiment, the temperature rising characteristic of the PTC element 1 is increased. It can be seen that the preheating time of 3 to 5 seconds is sufficient because the heating is fast. At this time, the room temperature is −25 ° C., the power supply voltage is 24 V, and it is necessary to increase the current in order to shorten the preheating time. The resistance of PTC element 1 is adjusted. FIG. 5 is a characteristic diagram showing thermal efficiency including intake air heating (after heating) after engine cranking. Here, the thermal efficiency is represented by the ratio of the amount of heat used to raise the temperature of air to the actually consumed electric power. Fifth
As shown in the figure, the device of this embodiment is superior to the metal wire device in both the efficiency at the initial startup and the efficiency in the steady state. This is because when the PTC element 1 is used, it has excellent immediate heating properties and the element itself performs intake air heating at a relatively low temperature, so that heat loss is small. FIG. 6 shows a measuring bench used for measuring the thermal efficiency of the device. An intake heating device 10 is installed in the expansion section 20a of the hot air passage 20, and a position 40 cm downstream of the device 10 is the temperature measuring point. is there. Reference numeral 21 is a blower for blowing air, 22 and 23 are manometers for measuring pressure loss side and flow rate, and 24 and 25 are DC and AC power supplies for driving the device and the blower. The present invention is not limited to the above embodiment, but various modifications can be made as follows. (1) The graphite filler layer 1a is intended to improve heat and electrical contact failure due to unevenness of the surface of the heat transfer plate 2b or the surface of the PTC element 1, so that only the bent portion of the heat transfer plate 2b, that is, the pressing surface. It may be provided, or may be provided on both the PTC element 1 and the heat transfer plate 2b. (2) Instead of the graphite filler layer 1a, it is of course possible to employ a sheet of a heat resistant rubber material in which carbon or metal powder or fibers are dispersed and composited. (3) Instead of the meandering fins 2a of the heat dissipation block 2, a honeycomb-shaped metal fin or a porous metal fin may be used. (4) The intermediate heat dissipation blocks 2 are combined in three rows and pressed against each other, but instead of pressing, soldering may be performed between the pressing surfaces of the heat transfer plate 2b, or three rows of heat dissipation blocks may be used. It is needless to say that the heat radiation block may be formed of one integrated heat radiation block. (5) Instead of pressing the heat dissipation block 2 and the PTC element 1 with the spring 5, they may be fixed and pressed by a method such as screwing to the case 3. (6) The louver 2'a provided on the radiation fin 2a may be omitted.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 (a) is a front view showing an embodiment of the present invention, FIG. 1 (b) is a sectional view taken along the line AA of FIG. 1 (a), and FIG. 1 (c) is FIG. 1 (a) is a sectional view taken along the line BB, FIG. 2 is a partially enlarged view showing the heat dissipation block of FIG. 1 (a), FIG. 3 is a schematic view showing an example of a mounting location of a heating device, and FIG. FIG. 5 is a characteristic diagram showing an intake air heating characteristic of the heating device, FIG. 5 is a characteristic diagram showing an intake air heating characteristic of the heating device, and FIG. 6 is a schematic diagram showing a configuration of a measurement bench. 1 ... PTC element, 1a ... graphite sheet layer, 2 ...
Heat dissipation block, 2a ... Heat dissipation fin, 2b ... Heat transfer plate, 3 ... Case, 3a ... Lower case, 3b ... Cover, 3f
…… Convex part, 4 …… Housing, 4c …… Opening part, 8 …… Clip.

Continuation of front page    (72) Inventor Makoto Hori               1-1 1-1 Showacho, Kariya City Nippondenso Co., Ltd.               In the formula company                (56) References JP-A-53-92933 (JP, A)                 Actual exploitation Sho 57-126194 (JP, U)                 Actual exploitation Sho 57-79333 (JP, U)

Claims (1)

(57) [Claims] A plurality of plate-shaped heating elements that are arranged in parallel with each other and generate heat when energized, and a plurality of heat radiation blocks that are arranged between at least the parallel arrangement of the plurality of heating elements and that have a passage portion through which a medium to be heated passes A substantially quadrangular heat dissipation part consisting of, and a mode that extends in a direction intersecting the parallel direction of the plate-shaped heat generating element and extends across the plurality of plate-shaped heat generating elements and the plurality of heat dissipation blocks, facing each other. Multiple vertical frame parts,
A plurality of horizontal frame portions facing each other, which connect the vertical frame portions, and at least a part of the plurality of horizontal frame portions,
The side wall surface is provided so as to have an L-shaped cross section, and the opening is smaller than the heat radiating portion surrounded by the vertical frame portion and the horizontal frame portion so that a part of the heat radiating portion is exposed. By providing a substantially quadrangular frame portion having a through opening having an area and a support portion for supporting the heat radiation portion at one end, the opening area becomes smaller than that of the heat radiation portion, and the other end is Through a frame-shaped and substantially rectangular housing provided with a through opening having an opening area larger than that of the heat radiating portion, and the side wall surface of the frame arranged on the other end side of the through opening of the housing. Between the frame portion and the supporting portion of the housing by fixing the frame body to the housing by pressing the heat radiation portion in one direction intersecting the parallel direction of the heating element. To hold Heating device comprising a constant section, in that it consists of. 2. A plurality of vertical frame portions facing each other in a mode that extends in a direction intersecting the parallel direction of the plate-shaped heat generating element and crosses the plurality of plate-shaped heat generating elements and the plurality of heat radiation blocks, and the vertical frame. A plurality of horizontal frame parts facing each other that connect the parts, and smaller than the heat dissipation part surrounded by the vertical frame part and the horizontal frame part so that a part of the heat dissipation part is exposed. Forming a box-like shape by the substantially rectangular lower frame portion having a through opening having an opening area and the frame portion, and enclosing the heat radiating portion inside the box-like shape, and by the fixing means. The heating device according to claim 1, wherein the frame portion and the lower frame portion surrounding the heat radiating portion are fixed to the support portion of the housing. 3. The fixing means is a U-shaped spring member that is provided between the side wall surface of the frame portion and the inner wall of the through opening of the housing and is provided with a restoring force in a spreading direction. The heating device according to claim 1. 4. In the fixing means, the convex portion provided on the one horizontal frame portion of the frame portion is provided with a spring member of the housing,
The U-shaped member is fixed between the side wall of the frame and the inner wall of the through-opening of the housing, while the frame is fixed movably in the pressing direction, and a restoring force is applied in the expanding direction. The heating device according to claim 1, wherein the heating device is a spring member.