JP2001001751A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent air temperature at a low wind speed (small wind amount) portion from rising extremely high during heating and prevent heat generated therefrom escaping into an air-conditioning case 1. SOLUTION: In this air conditioner, among a plurality of electric heat generators 8a, 8b, 8c, calorific power of the one disposed at a portion with a high wind speed is increased, while calorific power of the one disposed at a portion with a low wind speed is reduced. Accordingly, it is possible to prevent an excessive rise of an air temperature at the low wind speed portion and reduce an amount of heat escaped therefrom to an air-conditioning case 1. Thus heat generated from the electric heat generators 8a, 8b, 8c can be utilized effectively for heating a vehicle interior.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner having an electric heating element as a heating heat source, and is particularly suitable for a vehicle air conditioner using a heating heat exchanger using hot water or the like as a heat source.

[0002]

2. Description of the Related Art In recent years, as vehicle engines have become more efficient,
Even after the engine is warmed up, the cooling water (hot water) temperature of the vehicle engine tends to be lower than before.
In particular, the above-mentioned tendency is remarkable because a diesel engine generally has higher thermal efficiency than a gasoline engine. For this reason, in a hot water type air conditioner that heats the interior of a vehicle cabin by using waste heat from engine cooling water, insufficient heating capacity has been an issue. In order to solve the shortage of the heating capacity by using a hot-water heating heat exchanger and an electric heating element together and heating the heating air by the heat generated by the electric heating element, French Patent Publication No. 2742384 and the like disclose such a technique. Has been proposed.

[0003]

However, the wind speed distribution in the air passage in the air-conditioning case is generally not uniform. Therefore, when the heat generation amount of each part of the electric heating element is uniform, the wind speed is reduced. The temperature of the air in the portion where the wind speed is low (the amount of air is low) becomes higher than the temperature of the air in the portion where the air volume is high (the amount of air is large). In areas where the wind speed is extremely low, the temperature of the air becomes extremely high, and the heat easily escapes from the high-temperature air to an air-conditioning case or the like, and the heat generated by the electric heating element is effectively used for heating the vehicle interior. There was a problem that was not.

[0004] The present invention has been made in view of the above points, and it is an object of the present invention to make it possible to effectively use the heat generated by an electric heating element for heating a vehicle compartment even when the wind speed distribution is not uniform. I do.

[0005]

In order to achieve the above object, according to the present invention, the air passage (10) is provided.
A plurality of electric heating elements (8a, 8b, 8c) arranged in 0)
Among them, the heat generation amount of the electric heating element disposed at the portion where the wind speed is high is increased, and the heat generation amount of the electric heating element disposed at the portion where the wind speed is low is reduced.

[0006] According to this, it is possible to prevent the temperature of the air in the portion where the wind speed is low (the amount of air is low) from excessively rising, and thereby, the heat escaping from the air in the portion where the wind speed is low to the air-conditioning case or the like. Of the electric heating elements (8a, 8a
The heat generated in b, 8c) can be effectively used for heating the vehicle interior. Moreover, electric heating elements (8a, 8b, 8c)
Since the temperature of the air after passing through becomes substantially uniform regardless of the passing position, the temperature variation of the blown air can be reduced.

According to a second aspect of the present invention, as the heating element (84) of the electric heating element (8a, 8b, 8c),
A PTC heater element having a positive resistance temperature characteristic can be used.

According to the third aspect of the present invention, the number of PTC heater elements is changed for each of the plurality of electric heating elements (8a, 8b, 8c) to generate heat for each of the plurality of electric heating elements (8a, 8b, 8c). It is characterized by changing the amount.

According to this, a plurality of electric heating elements (8a,
8b, 8c), the amount of heat generated for each of the plurality of electric heating elements (8a, 8b, 8c) can be changed even when the supply voltage to each of the plurality of electric heating elements (8a, 8b, 8c) is the same. Power supply can be used.

[0010] The reference numerals in parentheses of the above means indicate the correspondence with the specific means described in the embodiment described later.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an entire configuration of a ventilation system in an embodiment in which the present invention is applied to a vehicle air conditioner (car air conditioner). A case 1 constitutes an air passage of the air conditioner. It is installed in the instrument panel (not shown) at the front of the room. In the case 1, a blower 2 as a blower is disposed in the upper right part (upper part on the front side of the vehicle) in FIG. The blower 2 is composed of a well-known centrifugal multi-blade fan driven by a motor, and sucks air into the inside of the case 1 through an intake-side duct (not shown) connected to the case 1 to blow in the direction of arrow A. It has become.

Here, an evaporator as cooling means for cooling the blown air is disposed in the intake side duct, and furthermore, an inside air inlet and an outside air inlet are provided upstream of the evaporator in the air. At the same time, an inside / outside air switching door for opening any of the intakes is provided. The evaporator is provided in a refrigeration cycle having a compressor driven by a vehicle engine, and cools the blown air by the latent heat of evaporation of the refrigerant.

In the case 1, a heater core 3 as a heat exchanger for heating is disposed in a substantially horizontal direction at a lower right portion (a lower portion on the front side of the vehicle) in FIG. The heater core 3 circulates cooling water (warm water) of the vehicle engine by a pump (not shown), and heats the blown air using the engine cooling water as a heat source.

Further, a warm air passage 100 is formed below the heater core 3 by the case 1, and the warm air passing through the warm air passage 100 flows rightward in FIG. ), Flows downward at a rear bottom portion, and flows upward from the left side (rear side of the vehicle) in FIG. In the middle of the hot air passage 100 and below the heater core 3, an electric heater 8 as a heating means is disposed at an angle of about 30 degrees so that the front side of the vehicle is lowered. The electric heater 8 heats the heating air by the heat generated by the electric heating element as described later.

At the air upstream side of the heater core 3,
An air mix door 4 is provided. The air mixing door 4 controls the temperature of the air blown into the passenger compartment by rotating about the rotation shaft 4a. The air mixing door 4 is manually operated by an occupant or automatically controlled by an automatic temperature control signal of an air conditioning control device. The opening is adjusted to a corresponding degree.

According to the degree of opening of the air mix door 4,
Of the air blown in the direction of arrow A by the blower 2, the hot air passage 100 passes through the heater core 3 and the electric heater 8.
Is adjusted between the warm air flowing in the arrow B direction and the cool air flowing in the cool air passage 101 in the arrow C direction without passing through the heater core 3 and the electric heater 8. In this example, the cold air passage 101 and the hot air passage 100
Are arranged in the vertical direction in FIG. 1 with the heater core 3 in the middle. And these passages 100, 10
In most cases, the cool air and the warm air flowing through 1 are satisfactorily air-mixed in an arc-shaped rotary door 91 described later.

On the other hand, in the case 1, a plurality of, in this example, three, blow-off air passage openings 5, 6, 7 are provided at the upper left portion (upper portion on the rear side of the vehicle) of FIG. The rotary door 91 is provided so as to be adjacently arranged in the rotation direction (circumferential direction) of the rotary door 91 in the rotation area. Therefore, the blow-off air passage opening 5 on the case 1 side,
The ends of the partition walls 6 and 7 are formed in an arc surface.

A blow-off air passage opening 5 located in the middle of the rotary direction of the rotary door 91 is a face blow-out port (shown in the figure) for blowing air toward the upper body of the occupant, which is disposed above the instrument panel in the cabin. No) and face outlet duct 1
It is communicated by 0. In the rotation direction of the rotary door 91, the outlet air passage opening 6 located at the rearmost side of the vehicle is disposed below the instrument panel of the vehicle interior and is a foot outlet (outlet) for blowing air toward the lower body of the occupant. (Not shown) and a foot outlet duct 11.

The outlet air passage opening 7, which is located closest to the front of the vehicle in the direction of rotation of the rotary door 91, is disposed on the upper surface of the instrument panel in the vehicle and close to the glass surface of the vehicle. A defroster outlet (not shown) for blowing out conditioned air toward the inner surface of the glass or side glass is communicated with a defroster duct 12. The three outlet air passage openings 5, 6, 7 described above are:
Each of them is formed in a substantially rectangular shape whose longitudinal direction is the direction from the front surface to the back surface in FIG.

When the blower 2 is driven, the inside air or the outside air is sucked from the intake side duct and guided into the case 1 through the evaporator, and the inside of the case 1 is further aired as indicated by arrows A, B and C. Flows, and the ratio of the amount of cool air to the amount of warm air is adjusted by the opening of the air mix door 4 to obtain a desired blown air temperature. Then, the blown air is blown out from each blowout port in the vehicle through one of the blowout air passage openings 5, 6, 7.

Incidentally, the rotary door 91 is connected to the film member 9.
2 together with the air passage switching device 9. The detailed configuration of the air passage switching device 9 is described in
Since it is described in detail in, for example, Japanese Patent Publication No. -188125, it will be briefly described here.

The rotary door 91 has a semi-cylindrical peripheral wall 91a having an arc range of approximately 180 °.
, A long and narrow door vent 91b is formed in the axial direction. A film member 92 is arranged on the outer peripheral surface side of the circumferential wall 91a. The film member 92 is formed of a resin material (for example, polyethylene terephthalate) having flexibility (flexibility), no air permeability, and low frictional resistance. A film opening 92a that is always in communication with the door ventilation port 91b is formed at an intermediate portion of the film member 92. The film member 92 is held by the rigidity of itself and the wind pressure received from the inner peripheral side in an arc shape along the arc surface on which the blowout air passage openings 5, 6, 7 on the case 1 side are formed.

The rotary door 91 constructed as described above
Has a lever 21 fixed to a rotating shaft (not shown), and one end of a control cable 22 is connected to an end of the lever 21. The other end of the control cable 22 is connected to an air outlet mode switching lever (air outlet mode switching operating means) provided on an air conditioning control panel (not shown) in the vehicle cabin. Thereby, the rotary door 91 rotates in the rotation direction (FIG. 1) based on the manual operation of the blowout mode switching lever.
(Arrows D and E directions).

Next, the electric heater 8 will be described with reference to FIGS. The electric heater 8 is installed at a position where the direction of the air flow can be largely changed as shown by the arrow B. In this case, the wind speed distribution at the portion of the electric heater 8 indicates that the air flow B has a higher speed near the outside of the case 1 and a direction closer to the inside of the case 1 as indicated by a number of arrows F in FIG. In this case, the speed is low, and this tendency is substantially constant irrespective of the opening degree of the air mix door 4 and the blowing mode.

In relation to the wind speed distribution, the electric heater 8 has three types of electric heating elements 8a, 8b, 8c having different heat generation amounts.
Are arranged with an insulating layer 8d interposed therebetween. That is, the first electric heating element 8a having the smallest heat generation amount is provided at a portion where the wind speed is lowest so that the wind speed (air volume) is proportional to the heat generation amount.
The third electric heating element 8c having the largest heat generation amount is arranged at the portion where the wind speed is the highest, and the heat generation amount is larger than the first electric heating element 8a at the portion where the wind speed is an intermediate speed between them. And a second electric heating element 8b smaller than the third electric heating element 8c.

The electric heater 8 has a rectangular metal frame 80.
Each of the electric heating elements 8a, 8b, 8c and the insulating layer 8d are stacked and arranged therein, and each of the electric heating elements 8a, 8b, 8c and the insulating layer 8d are arranged therein.
Between them, an aluminum corrugated fin 81 for increasing the air-side heat transfer area is arranged. One end (upper side in FIG. 2) of the frame body 80 is an end cover 82 made of resin.
The other end of the frame body 80 (the lower side in FIG. 2) is fitted to a mounting cover 83 made of resin. Note that both covers 8
Nos. 2 and 83 are made of a resin having excellent heat resistance and electrical insulation. Specifically, a resin (Nylon 66.G30) obtained by adding 30% by weight of a glass material to a nylon 66 material to improve rigidity and heat resistance. ) Can be used.

Then, the electric heater 8 is inserted through the opening 13 formed in the side surface of the case 1 and the mounting cover 83 and the case 1 are connected to each other by screws (not shown), thereby fixing the electric heater 8 to the case 1. ing. Here, the opening 1
A protrusion 14 projecting outward is formed on a peripheral edge of the housing 3, while a groove (not shown) in which the protrusion 14 can be fitted is formed in the mounting cover 83, and the electric heater 8 is connected to the case 1. In this state, the projections 14 are fitted into the grooves of the mounting cover 83 so that a predetermined sealing function can be obtained.

Each of the electric heating elements 8a, 8b of the electric heater 8,
8c have the same structure, although the calorific values are different. Each of the electric heating elements 8a, 8b, 8c is made of a resin (for example, nylon 66.G) having high heat resistance and electrical insulation.
30) an insulating plate 85 having an I-shaped cross section
As shown in FIG. 4, the insulating plate 85 has a large number (six in this example) of through-holes 85a formed therein.
A plate-like heating element 84 is embedded in a.

The heating element 84 and the insulating plate 8
On both sides of 5, an elongated flat electrode plate 86 is arranged. The electrode plate 86 is formed from a conductive metal material such as aluminum, copper, and stainless steel.
The electrode plate 86 and the electrode plate 86 are configured to be in pressure contact with each other so as to obtain electrical conduction therebetween. In addition, the periphery of the electrode plate 86 is covered with a covering member (for example, a polyimide resin or the like) over substantially the entire periphery (excluding the electrical connection portion) to improve corrosion resistance.

The insulating layer 8d includes an insulating plate 87 made of a resin (for example, nylon 66 and G30) having a high heat resistance and an electrical insulating property and having an I-shaped cross section, and electrode plates 86 arranged on both sides of the insulating plate 87. And a holding plate 88 of the same shape and material. Corrugated fins 81 are arranged between the holding plate 88 and the electrode plate 86, and the corrugated fins 81 are held by holding portions 86 a and 88 a formed by bending a part of each of the electrode plate 86 and the holding plate 88. ing.

Electrode plate 8 of each electric heating element 8a, 8b, 8c
6, a terminal portion 86b extending into a connector connecting portion 83a formed integrally with the mounting cover 83 is formed.
One of these terminals 86b is connected to the positive side of the battery 101 via the relay 100, and the other is connected to the ground. Therefore, the current from the battery 101 is supplied to the relay 100, the one electrode plate 86, the heating element 8
4, and flows in the order of the other electrode plate 86.

By the way, although various elements can be used as the heating element 84, in this example, particularly, the positive resistance temperature at which the resistance value rapidly increases at a predetermined Curie point (for example, around 200 ° C.). Resistor material with properties (eg,
A PTC heater element made of barium titanate) is used.

The through-hole 85a of the insulating plate 85
When the PTC heater elements are arranged at a plurality of locations, the PTC heater elements are electrically connected in parallel.
The number of TC heater elements to be assembled is determined by the electric heating elements 8a and 8
The amount of heat generated by the first to third electric heating elements 8a, 8b, 8c can be changed by changing the values for each of b and 8c. In this example, two PTC heater elements are disposed on the first electric heating element 8a, and four PTC heater elements are disposed on the second electric heating element 8b.
And the third electric heating element 8c is provided with six PTC heater elements, whereby the first to third electric heating elements 8a,
8b, 8c is less than the calorific value of the first electric heating element 8a <
The heat generation amount of the second electric heating element 8b <the heat generation amount of the third electric heating element 8c is set.

As described above, by changing the number of assembled PTC heater elements, the first to third electric heating elements 8a,
Even if the supply voltage to 8b, 8c is equal, the amount of heat generated for each of the first to third electric heating elements 8a, 8b, 8c can be changed,
A common power supply (the same voltage) can be used for the first to third electric heating elements 8a, 8b, 8c. Also, PTC
According to the heater element, as is well known, there is an advantage that a self-temperature control function for self-controlling the heat generation temperature to the Curie point can be exhibited.

Next, the operation of the above configuration will be described.
When the blower 2 is operated, the inside of the case 1 is indicated by arrows A,
Air flows as indicated by B and C, and the blown air reaches the inner peripheral side of the rotary door 91, where the cool air and the hot air are mixed. Next, the blast air is supplied to the ventilation port 91 of the rotary door 91.
d, through the opening 92a of the film member 92, and from one or more of the blow-off air passage openings 5, 6, 7 on the case 1 side wrapped with the film opening 92a, to the respective outlets. Blow into the room.

The switching operation of the blow-out mode accompanying the rotation of the rotary door 91 is described in Japanese Patent Laid-Open No. 9-188125.
Since it is described in detail in Japanese Patent Application Publication No. H10-64, etc., it will be briefly described here. When the user manually operates the air outlet mode switching lever in the vehicle, the operating force is controlled by the control cable 22.
And directly transmitted to the rotary door 91 via the lever 21, and the rotary door 91 rotates in the arrow D or E direction. Then, by rotating the rotary door 91, five blowing modes are selected.

First, in the face mode, the rotary door 91 rotates together with the film member 92 at the position shown in FIG.
a completely wraps around the outlet air passage opening 5 for the face. As a result, the air in the case 1 is
1d, the air flows into the face duct 10 through the face air outlet opening 5 through the film opening 92a, and is blown into the vehicle interior from the face outlet. Then, the rotary door 91 is sequentially rotated in the counterclockwise direction from the state of FIG. 1 by a predetermined angle, whereby the blow-out mode is switched in the order of the bi-level mode, the foot mode, the foot differential mode, and the defroster mode.

Next, the operation during heating will be described. When the outside air temperature is lower than the temperature set by the user, the air-conditioning control device turns on the relay 100 so that the first to third electric heating elements 8a, 8b, and 8c of the electric heater 8 are supplied from the battery 101. It is energized. As a result, the heating elements 84 of the first to third electric heating elements 8a, 8b, 8c generate heat, and the heat is transmitted to the corrugated fins 81 via the electrode plates 85, 86, etc. Dissipated by air. Therefore, at the time of heating, the blown air is heated by both the heater core 3 and the electric heater 8,
The lack of heating capacity can be resolved.

The air blown in the direction of arrow A by the blower 2 passes through the heater core 3 and the electric heater 8 and flows through the hot air passage 100 through the air mixing door 4 in the direction of arrow B.
The air (warm air) flowing in the direction of the arrow and the air (cool air) flowing in the direction of the arrow C without passing through the heater core 3 and the electric heater 8 are distributed. Here, by controlling the opening degree of the air mix door 4, the ratio of the amount of hot air to the amount of cold air, and thus the temperature of the blown air, is adjusted.

By the way, the electric heater 8 is installed at a portion where the direction of the air flow can be largely changed as shown by the arrow B, and the outside of the air flow B has a high wind speed (the amount of air is large), and the inside thereof has the wind speed. Is low (low air flow). Here, three types of electric heating elements 8a, 8b, and 8c having different heating values are set so that the wind speed of the air passing through the electric heater 8 is proportional to the heating values of the first to third electric heating elements 8a, 8b, and 8c. 8
Since c is arranged corresponding to the wind speed, the temperature of the air heated by the electric heater 8 becomes substantially uniform regardless of the air passage position.

Therefore, conventionally, the temperature of the air becomes extremely high in a portion where the wind speed is low, and the case 1
There was a problem that heat escaped easily, etc.
In the present embodiment, the temperature of the air is substantially uniform irrespective of the passage position of the air, and the temperature of the air in the portion where the wind speed is low does not become particularly high, so that the air in the portion where the wind speed is low escapes to the case 1 and the like. The amount of heat is reduced, and the heat of the electric heater 8 is effectively used for heating the vehicle interior. Further, as described above, since the temperature of the air after passing through the electric heater 8 becomes substantially uniform regardless of the passing position, the temperature variation of the air blown into the vehicle interior is reduced. (Other Embodiments) In the above embodiment, a PTC heater element is used as the heating element 84, and by changing the number of heating elements 84 connected in parallel, each of the electric heating elements 8a,
Although the calorific values of 8b and 8c are changed, PTC heater elements having different Curie points are used, a PTC heater element having a low Curie point is arranged in a region where the wind speed is low, and a PTC heater having a high Curie point is arranged in a region where the wind speed is high. Even when the elements are arranged, the temperature of the air heated by the electric heater 8 becomes substantially uniform irrespective of the air passage position, and the same effect can be obtained.

Further, PTC heater elements are stacked and arranged,
The PTC heater elements are configured to be electrically connected in series, and the number of stacked PTC heater elements is determined by each electric heating element 8.
a, 8b, and 8c, each electric heating element 8
a, 8b, and 8c, thereby changing the electric resistance value of the heating element 84, whereby the first to third electric heating elements 8a, 8b, 8
It is also possible to change the calorific value of c. Specifically, the first electric heating element 8a at the portion where the wind speed is lowest is PT
The electric resistance value is increased by increasing the number of stacked C heater elements, and the third electric heating element 8c at the portion where the wind speed is highest is:
The electric resistance value is reduced by minimizing the number of stacked PTC heater elements.

The heating element 84 is not limited to the PTC heater element, and various types of heating elements that generate heat when energized can be used.

In the above embodiment, three types of electric heating elements 8a, 8b and 8c having different heating values are provided. However, according to the wind speed distribution of the electric heater 8, two or four types of electric heating elements are provided. The above may be used.

As shown by a number of arrows H in FIG.
In the case where the wind speed distribution is not uniform in the heater core 3 as well, the temperature of the air in the low wind speed portion at the time of passing through the heater core 3 increases, and the temperature of the air flowing into the electric heater 8 becomes higher toward the first electric heating element 8a. Become. Therefore, taking into consideration the temperature distribution of the air flowing into the electric heater 8, each of the electric heating elements 8a, 8b,
By setting the calorific value of 8c, the temperature of the air after passing through the electric heater 8 can be made more uniform regardless of the air passing position.

Further, in the above embodiment, the heater core 3 and the electric heater 8 are provided separately, but it is also possible to implement the electric heater 8 integrally with the heater core 3.
When the heater core 3 and the electric heater 8 are integrated, it is advantageous in that the air conditioner can be made compact. On the other hand, when the heater core 3 and the electric heater 8 are separate, the electric heater 8 must be mounted. Regardless of whether or not the heater core 3 is used in common, it is advantageous.

Further, the present invention is applicable to air conditioners other than those for vehicles.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an outline of a ventilation system of a vehicle air conditioner according to an embodiment of the present invention.

FIG. 2 is a plan view of the electric heater of FIG.

FIG. 3 is a sectional view taken along line GG of FIG. 2;

FIG. 4 is a J view of the insulating plate of FIG. 3;

[Explanation of symbols]

1 ... case, 8a, 8b, 8c ... electric heating element, 100 ...
Hot air passage (air passage).

Claims (4)

[Claims] An air passage (1) formed in a case (1).
00), a plurality of electric heating elements (8a, 8
b, 8c), and, among the plurality of electric heating elements (8a, 8b, 8c), the amount of heat generated by the electric heating element disposed at a high wind speed part is determined by the electric heating element disposed at a low wind velocity part An air conditioner characterized by having a heating value higher than that of the air conditioner. 2. A heating element (84) of the electric heating element (8a, 8b, 8c) has a positive resistance temperature characteristic.
The air conditioner according to claim 1, wherein the air conditioner is a C heater element. 3. The electric heating element (8a, 8b, 8)
3. The air conditioner according to claim 2, wherein the number of the PTC heater elements is changed every c), and the heat generation amount of each of the plurality of electric heating elements is changed. 4. A heating heat exchanger (3) for heating air using a fluid flowing inside as a heat source, said air passage (100).
The heating heat exchanger (3) and the plurality of electric heating elements (8
a, 8b, 8c) separately from each other, and the plurality of electric heating elements (8a, 8b, 8c) are disposed downstream of the air flow of the heating heat exchanger (3). The air conditioner according to any one of claims 1 to 3.