JP2001088538A - Vehicle heating heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce stress applied to tube rooting parts near an electric heating body even if the internal pressure of a tank is repeatedly heightened in structure with the electric heating body integrated with a heating heat exchanger for heating air with hot water heated by an engine, as a heat source. SOLUTION: A sheet metal of a tank is provided with a recessed shape part for brazing and jointed to a holder plate of an electric heating body by brazing. The holder plate thereby supports a tank part instead of tubes, and stress applied to tube rooting parts can be reduced. Or an embossed part is provided inside the tank near the end part of the electric heating body, and a tank body part and the sheet metal are jointed through the embossed part. Or a reinforcing member, which is a separate part, is jointed to the tank part near the end part of the electric heating body by brazing. The strength of the tank part is thereby enhanced, and stress applied to the tube rooting parts can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger for vehicle heating, which heats air using hot water (engine cooling water) heated by a vehicle engine (internal combustion engine) as a heat source, in which an electric heating element is integrated. It relates to a heat exchanger.

[0002]

2. Description of the Related Art Conventionally, a heat exchanger in which an electric heating element of this type is integrated is a heat exchanger for vehicle heating, which heats air using hot water (engine cooling water) as a heat source. Therefore, when the temperature of the hot water is low, such as immediately after the start of the engine, the amount of heat generated by the electric heating element can be radiated into the air through the high-performance corrugated fins of the heat exchange core by energizing the electric heating element. In addition, the heat radiation structure of the electric heating element can be simplified. Further, since there is no need to install an independent electric heating element separately from the heating heat exchanger, it is possible to prevent an increase in pressure loss in the ventilation system of the heating device due to the installation of the electric heating element.

[0003]

FIG. 8 is a sectional view showing a conventional tank and the vicinity of an end of an electric heating element. In this apparatus, an electric heating element (holder plate with a built-in heating element) is interwoven in a flat tube row. However, in order to prevent hot water from entering the electric heating element and to prevent hot water from leaking through the electric heating element, both ends of the holder plate constituting the electric heating element are inserted and joined to the tank unlike flat tubes. Absent. In addition, when joining the entire heat exchanger into an integrated structure by brazing, the dimensions between the two tanks are liable to fluctuate, so that when both end portions of the holder plate abut against the tank, the joining state of that portion becomes unstable. For this reason, both ends of the holder plate and the tank were joined at a predetermined interval.

However, according to a study by the present inventor, when pressure is applied to the inside of the tank, the tank main body is finely deformed so as to expand in a round shape, and the deformation causes the outer peripheral portion of the sheet metal joined to the tank main body side to be deformed. Tensile stress is generated. This stress acts to deflect the sheet metal, and as a result, a stress is applied that pulls the root of the flat tube (the joint between the sheet metal and the flat tube). In particular,
Since the brazing pitch between the tank and the flat tube is increased only at the portion of the electric heating element, the tank near both ends of the electric heating element is easily deformed, and the stress is added to the roots of the tubes on both sides of the electric heating element. It turned out that durability was lowered.

Accordingly, an object of the present invention is to pay attention to the above points, and in a type using a heating element element-containing holder plate different from a flat tube for hot water, a simple structure is applied to the tube roots on both sides of the electric heating element. An object of the present invention is to provide a heat exchanger for vehicle heating that can reduce stress.

[0006]

In order to achieve the above object, according to the first aspect of the present invention, a part of a tank is constituted,
A concave portion for brazing is provided at a position corresponding to the position of both ends of a sheet plate of a sheet metal serving as a joining member with a number of flat tubes, and both ends of the holder plate are inserted into the concave portions, respectively. Then, both ends of the sheet metal and the holder plate were joined by brazing.
Thereby, the dimensional variation between the two tanks when the entire heat exchanger is joined to the integral structure by brazing is absorbed by the end of the holder plate being able to move within the recessed portion, and is joined to the integral structure. After that, since the holder plate supports the tank portion instead of the tube to suppress the deformation, the stress applied to the tube roots on both sides of the electric heating element can be greatly reduced.

According to the second aspect of the present invention, one or both of the tank body and the sheet metal constituting the tank are provided in the tank near both ends of the electric heating element which is swelled by the pressure in the tank and easily deformed. The part was provided with an embossed part projecting into the tank, and this embossed part was joined to an opposing part in the tank. Thereby, since the embossed portion serves as a reinforcing member in the tank and suppresses deformation due to pressure, it is possible to reduce the stress applied to the tube roots on both sides of the electric heating element.

According to the third aspect of the present invention, the reinforcing member of the tank is joined to the tank portion near both ends of the electric heating element which is swelled by the pressure in the tank and easily deformed. Thereby, since the strength of the tank portion is increased and the deformation due to the pressure is suppressed, the stress applied to the tube roots on both sides of the electric heating element can be reduced.

According to the fourth aspect of the present invention, the joining or brazing of the reinforcing member at the embossed portion is limited to a part of the tank corresponding to the space between the flat tubes sandwiching the holder plate. Thereby, the number of members for reinforcement can be reduced, and the weight and cost of the apparatus can be reduced.

[0010]

Next, embodiments of the present invention will be described with reference to the drawings. [First Embodiment] A first embodiment will be described with reference to FIGS. FIG. 1A is a front view of a vehicle heat exchanger, and FIG. 1B is a cross-sectional view of a portion A of the heat exchanger showing a joint between the tank 1 and the electric heating element 9. FIG. 8 is a sectional view of the conventional heat exchanger for heating showing the vicinity of the ends of the tank 1 and the electric heating element 9.

The heat exchanger for heating a vehicle according to the present embodiment has a hot water inlet side tank 1, a hot water outlet side tank 2, and a heat exchange core portion 4 provided between the two tanks. .

The hot water inlet tank 1 is provided with an inlet pipe 5 through which hot water (engine cooling water) from a vehicle engine (not shown) flows in, and the hot water outlet tank 2 allows hot water to flow out of the tank 1. Outlet pipe 6 to recirculate
Is provided. Since the heat exchanger of this example is vertically symmetrical when the electric wiring cover 10 is not mounted, the hot water inlet side tank 1 and the hot water outlet side tank 2 may be turned upside down.

Each of the tanks 1 and 2 has a tank body 1
a and a sheet metal 1b that closes the open end face of the tank body 1a, and has a well-known tank structure in which the left-right direction in FIG. A plurality of flat tube insertion holes (not shown) are formed in the sheet metal 1b in a row or a plurality of rows in the left-right direction of FIG.

A plurality of flat tubes 3 formed in a flat shape parallel to the flow direction of heating air (perpendicular to the plane of FIG. 1) are arranged in parallel in the left and right direction of FIG. ing. A corrugated fin (fin member) 7 shaped like a wave is arranged and joined between the plurality of flat tubes 3. This corrugated fin 7
As is well known, a large number of louvers (not shown) are cut and raised obliquely at a predetermined angle to the flow direction of the heating air, and the louvers are shaped to improve the fin heat transfer coefficient.

The openings at both ends of the flat tube 3 are inserted into the tube insertion holes of the sheet metal 1b and joined. Further, a side plate 8 having a U-shaped cross section is further outside the outermost corrugated fin 7 of the heat exchange core 4.
The side plates 8a and 8b are joined to the outermost corrugated fins 7 and the sheet metal 1b.

By the way, in the heat exchanger of this embodiment, all of the above-mentioned components 1 to 8b are formed of an aluminum alloy, and the joining between the components is performed integrally by using a brazing material clad in the aluminum alloy. Perform it with
This integral brazing is performed at the installation site of the electric heating element 9 (FIG. 1).
In the example of (a), the flat tube 3 is abolished, and instead, the holder plate 9 having a U-shaped cross section made of an aluminum alloy, which is a holding member for the heating element 9a, is used instead.
b is arranged. In the sheet metal 1b at positions corresponding to both end portions of the holder plate 9b, recessed portions 1c for brazing are provided by pressing, and
b is assembled so that both ends are accommodated in the recessed portion 1c. Further, the heating element 9 is provided in the holder plate 9b.
A dummy plate member (not shown) having a physique equivalent to a and made of a material which is not brazed is temporarily assembled, and the assembly position of the corrugated fin 7 is maintained.

Then, while maintaining the temporary assembly state of the entire heat exchanger with an appropriate jig, the heat exchanger is carried into a furnace and heated to a brazing temperature in the furnace to integrally braze the entire heat exchanger. I do. After the brazing is completed, the dummy plate member is removed from the core portion 4 of the heat exchanger joined to the integral structure,
Instead, as shown in FIG.
Are arranged at predetermined intervals at three places of the core part 4 and assembled. Finally, an electrical wiring cover 10 for supplying electricity to the heating element 9a is assembled and an electrical connection is made.

Next, the operation of the above configuration will be described.
During heating, an air-conditioning blower (not shown) operates, and heating air is blown into an air-conditioning unit case (not shown),
Heating air passes through a gap between the flat tube 3 and the corrugated fin 7 of the core portion 4 of the heating heat exchanger. On the other hand, warm water flows from the engine into the warm water inlet side tank 1 through the inlet pipe 5 by the operation of the water pump (not shown) of the vehicle engine.

The hot water is distributed to a number of flat tubes 3 in the inlet side tank 1 and radiates heat to the heating air via the corrugated fins 7 while flowing through the flat tubes 3 at the same time. The hot water that has passed through the multiple flat tubes 3 flows into the hot water outlet side tank 2 and is collected there, and the hot water flows out of the heat exchanger from the outlet pipe 6 and returns to the engine side.

On the other hand, when the temperature of the hot water from the engine is lower than a set temperature (for example, 80 ° C.) during heating, three electric heating elements 9 are provided in an electric circuit (not shown).
The number of currents to be controlled is controlled. That is, at the time of maximum heating, as the hot water temperature and the outside air temperature are lower, the number of energized three electric heating elements 9 is increased, and the over-discharge of the on-board battery is generated by the charge / discharge balance signal of the on-board charging generator. Don't do it.

Then, when the electric heating element 9 is energized, the electric heating element 9 generates heat. Here, the electric heating element 9 rises to the self-control set temperature, and radiates the calorific value to the heating air via the adjacent corrugated fins 7, thereby quickly heating the heating air even at a low temperature of the hot water. To effect immediate heating.

As is well known, the PTC heater used for the electric heating element 9 has a positive resistance temperature characteristic in which the resistance value sharply increases at a predetermined set temperature. It has a self-temperature control function for controlling. [Second Embodiment] A second embodiment will be described with reference to a sectional view of a tank portion in FIG.

In the tank 1 near the end of the holder plate 9b, one or both of the tank body 1a and the sheet metal 1b constituting the tank 1 are provided with a punched portion 1d by pressing. Part 1d is tank 1
May be joined to an opposing portion of the inside (the embossed portion 1d, or the tank body portion 1a or the sheet metal 1b on the opposing side when only one side has the embossed portion 1d). In the above, the embossed portion 1d in the tank 1 has been described, but the same applies to the inside of the tank 2. [Third Embodiment] A third embodiment will be described with reference to the sectional views of the tank portion in FIGS.

As shown in FIG. 3, the portion joined at the embossed portion 1d in the second embodiment is provided on one end side of the reinforcing member 11 by using a separate component reinforcing member 11 made of an aluminum alloy. The tank body 1a and the sheet metal 1b may be joined by engaging the protrusion 11a with the hole of the tank body 1a and brazing it upright in the tank 1 near the end of the holder plate 9b.

FIG. 4 is a modification of the one shown in FIG. The reinforcing member 11 may be formed so as to fit to the inner surface of the tank body 1a, and may be joined to the inside of the tank 1 near the end of the holder plate 9b by brazing.

FIG. 5 is a modification of the one shown in FIG. The reinforcing member 11 may be formed so as to fit to the outer surface of the tank body 1a, and may be joined to the outside of the tank 1 near the end of the holder plate 9b by brazing.

FIG. 6 is a modification of the one shown in FIG. The reinforcing member 11 may be formed so as to fit to the inner surface of the sheet metal 1b, and may be joined to the inside of the tank 1 near the end of the holder plate 9b by brazing.

FIG. 7 is a modification of the one shown in FIG. The reinforcing member 11 may be formed to fit the outer surface of the sheet metal 1b, and may be joined to the outside of the tank 1 near the end of the holder plate 9b by brazing.

Although FIGS. 3 to 7 have described the example in which the reinforcing member 11 is provided on the tank 1 side, the reinforcing member is similarly provided on the tank 2 side. Omitted. The holder plate 9b has a cross section U
It may be a U-shaped plate or another shape such as using two flat plates.

[Brief description of the drawings]

FIG. 1A is a front view of a heating heat exchanger, and FIG. 1B is a cross-sectional view of a joint between a tank and an electric heating element according to the first embodiment.

FIG. 2A is a cross-sectional view of a tank unit according to a second embodiment, and FIG. 2B is a cross-sectional view as viewed from a side.

FIG. 3A is a cross-sectional view of a tank unit according to a third embodiment, and FIG. 3B is a cross-sectional view as viewed from a side.

FIGS. 4A and 4B show a modification of the third embodiment, in which FIG. 4A is a cross-sectional view of a tank portion, and FIG.

5A and 5B show another modified example of the third embodiment, in which FIG. 5A is a cross-sectional view of a tank portion, and FIG. 5B is a cross-sectional view as viewed from a side.

6A and 6B show another modified example of the third embodiment, in which FIG. 6A is a cross-sectional view of a tank portion, and FIG. 6B is a cross-sectional view as viewed from a side.

FIGS. 7A and 7B show another modification of the third embodiment, in which FIG. 7A is a cross-sectional view of a tank portion, and FIG.

FIG. 8 is a cross-sectional view of a conventional tank and the vicinity of an end of an electric heating element.

[Description of Signs] 1, 2 Tank 1a Tank main body 1b Sheet metal 1c Depressed portion 1d Embossed portion 3 Flat tube 4 Heat exchange core 5 Inlet pipe 6 Outlet pipe 7 Corrugated fin (fin member) 8a, 8b Side Plate 9 Electric heating element 9a Heating element 9b Holder plate 10 Cover for electric wiring 11 Reinforcement member 11a Convex part

Claims (4)

[Claims] 1. A heat exchange core portion is formed by arranging a number of flat tubes through which hot water from a vehicle engine flows and joining corrugated fins to the flat tubes. A tank for distributing or collecting hot water to the tubes, wherein the flat tubes are brazed so as to penetrate a sheet metal constituting a part of the tank and communicate with the inside of the tank, and the heat exchange core In a heat exchanger for vehicle heating that uses a holder plate different from the flat tube as a part of the part and incorporates an electric heating element in the plate, the sheet metal corresponds to the positions of both ends of the holder plate. A brazing recess is provided at each position, and both ends of the holder plate are inserted into the recesses, respectively. A heat exchanger for heating a vehicle, wherein both ends of the metal plate and the holder plate are joined by brazing. 2. A plurality of flat tubes through which hot water from a vehicle engine flows are arranged in parallel, and a corrugated fin is joined to the flat tubes to form a heat exchange core portion. A tank for distributing or collecting hot water to the tubes, wherein the flat tubes are brazed so as to penetrate a sheet metal constituting a part of the tank and communicate with the inside of the tank, and the heat exchange core In a vehicle heating heat exchanger using a holder plate different from the flat tube as a part of the portion and incorporating an electric heating element in the plate, one or both of the tank body and the sheet metal constituting the tank are provided. A punching portion is provided in a part of the tank so as to protrude into the tank, and the punching portion is provided at a position corresponding to a position of both ends of the holder plate. A heat exchanger for heating a vehicle, wherein a heat shield portion is joined to an opposing portion in the tank. 3. A plurality of flat tubes through which hot water flows from a vehicle engine are arranged in parallel, and a corrugated fin is joined to the flat tubes to form a heat exchange core portion. A tank for distributing or collecting hot water to the tubes, wherein the flat tubes are brazed so as to penetrate a sheet metal constituting a part of the tank and communicate with the inside of the tank, and the heat exchange core In a vehicle heating heat exchanger using a holder plate different from the flat tube as a part of the part and incorporating an electric heating element in the plate, the tank is located at a position corresponding to the position of both ends of the holder plate. A heat exchanger for heating a vehicle, wherein a reinforcing member of the tank is partially joined by brazing. 4. The tank according to claim 2, wherein the joining portion formed by the embossed portion or the reinforcing member is provided at least in a part of the tank corresponding to between the flat tubes sandwiching the holder plate. 4. The heat exchanger for vehicle heating according to 3.