JPS63184513A - Air conditioner for automobile - Google Patents

Abstract

PURPOSE:To abate the increment of ventilating resistance and noise due to a resistor while securing coolability of this resistor by constituting a heating unit of the resistor for regulating air quantity of an air blower, to be capable of rising or setting from or to a ventilation flue according to the voltage control operation. CONSTITUTION:An air blower 2 is set up in an upstream end of a ventilation flue 1. And, this air blower 2 is constituted of an impeller 2a and an electric motor 2b for driving this impeller. In addition, a battery 6, a fan speed selector switch 7 and a resistor 8 are connected to the motor 2b in series. Likewise, plural heating parts electrically connected, that is, respective resistors 8a are installed in the resistor 8, and these resistors 8a are set up in a recess of a scroll casing 9. At this time, each resistor 8a is formed with a shape memory alloy, whereby these resistors 8a are extended to the ventilation flue 1 by a form variation at the time of heating transformation, thereby cooling them by an air current.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an air conditioner for automobiles (hereinafter referred to as an air conditioner), and particularly to an air conditioner equipped with a blower whose driving source is an electric motor.

(Prior art) An air conditioner for an automobile includes a ventilation passage that selectively communicates between the inside and outside of the vehicle, and air conditioning equipment such as a blower and a heater core disposed within this ventilation passage. This system adjusts the temperature and humidity conditions of the air to condition the air inside the vehicle. In the above-mentioned type of air conditioner, a control means such as a resistor is provided to control the drive voltage of the motor and adjust the amount of air blown by the blower. During this voltage control,
Heat is generated in the control means. For this reason, for example,
As seen in Japanese Patent No. 138718, a configuration is adopted in which the control means itself or a radiation fin is installed in a ventilation passage, and the control means is cooled by the air flow passing through the ventilation passage.

(Problem to be Solved by the Invention) However, in the above configuration, the control means or the heat radiation fins are in the ventilation path even during maximum air blowing when no voltage control is performed and therefore no heat radiation is required. There was a problem in that the heat dissipation fins acted as ventilation resistance and increased the workload of the blower III, resulting in an increase in noise. Additionally, the control means etc. tend to disrupt the high-speed air flow in the ventilation passages, creating noise.

SUMMARY OF THE INVENTION In view of the problems of the prior art, it is an object of the present invention to provide an air conditioner that ensures sufficient heat dissipation of a resistor as a control means and has low noise.

(Means for Solving the Problems and Their Effects) To achieve the above object, the present invention provides a ventilation path for introducing air into the vehicle interior, and an air blower disposed in the ventilation path. It is equipped with a harmonizing device and a resistor that controls the drive voltage to the blower in order to adjust the air flow rate. An air conditioner for an automobile is provided in which a resistor is installed so as to be exposed to the air flow in a ventilation passage and cooled.

In the above configuration, the heat generating portion of the resistor made of a shape memory alloy is exposed into the ventilation path due to a change in shape due to heat generated during energization. Therefore, the resistor is sufficiently cooled by the air flow in the ventilation path only when the resistor performs voltage control operation. On the other hand, at maximum air flow when voltage control operation is not performed,
The heat-generating portion of the resistor is moved outside the ventilation path to reduce the ventilation resistance of the ventilation path, without increasing noise. In addition,
When air is blown at a temperature other than the maximum, the resistance of the ventilation path increases due to the protrusion of the heat generating part of the resistor, but since the speed of the air flow is relatively slow, the effect on air blowing performance and noise is small and does not pose a problem.

(Example) The present invention will be described below based on an example shown in the accompanying drawings.

FIG. 1 is a schematic diagram of an air conditioner for an automobile according to a first embodiment of the present invention, which device includes a ventilation passage 1. As shown in FIG.

The ventilation path 1 is constructed by connecting a plurality of casings made of a material such as a heat-resistant synthetic resin, and a blower 2 is disposed at the upstream end of the casing. Further, in the downstream side of the blower in the ventilation path 1, air conditioning equipment such as an evaporator 3 for dehumidification and cooling and a heater core 4 for heating are sequentially arranged. Furthermore, an air mix damper 5 is pivotally provided in the ventilation passage 1 so as to adjust the ratio of cold air and hot air mixed through the evaporator 3 and the core 4.

In this way, the air conditioner takes air into the ventilation path 1 using the air blower 112, controls the air temperature by appropriately mixing cold air and hot air according to the desired conditions, and controls the air temperature from each outlet of the ventilation path 1 into the vehicle interior. It is configured to blow air to. Note that the configuration of the air conditioner according to the present invention may be the same as the conventional one except for the parts described below, and therefore, a detailed explanation of the overall configuration and operation will be omitted here.

Air blast t! 12 is an impeller 2a as seen in FIG.
and an electric motor 2b for driving this.

The electric motor 2b is connected in series with a battery 6 as a power supply source, a fan speed changeover switch 7 and a resistor 8 for changing the driving voltage by $13111. In the case of this embodiment, the resistor 8 has two electrically connected heat generating parts, ie, resistors 8a and 8b, and these resistors are provided in the downstream side of the blower of the scroll casing 9 (FIG. 2). are placed in the respective recesses. As shown in the circuit diagram shown in FIG. 3, both ends 81 and 83 of the connected resistors serve as high speed (Hi) and low speed (LO) contacts, respectively, and the connecting end 82 between both resistors serves as medium speed (Me) contacts. It is connected as a contact to a changeover switch 7, and by switching the connections between these contacts and the movable contact of the switch 7, the resistance value of the resistor 8 can be changed stepwise. Note that an off switch for cutting off the connection with the battery 6 is also incorporated in the drive circuit of the motor 2b, but its illustration is omitted in FIG. 3 for the sake of simplification. Further, reference numeral 10 in FIG. 2 indicates a damper for switching between internal air circulation and outside air introduction.

FIG. 4 shows an enlarged view of one resistor 8a of the resistor.
The resistor 8b also has a similar structure. The resistor 8a is made of Cu-Z
It is made of a shape memory alloy such as n-A1 alloy and has a spiral shape similar to a coil spring.

The length of each resistor is determined according to the electrical resistance value per unit length of the resistor material and the required voltage in the corresponding motor rotational speed range. In addition, each resistor is molded and heat-treated so that it expands as shown in Figure 5 during heating transformation, and its transformation point is a temperature slightly lower than the heat generation temperature when energized (approximately 150 ~
300°C).

The resistor 8a is mounted on a bracket 11, and is attached to a recess of the scroll casing 9 by screwing the bracket 11 to the scroll casing 9 or the like. The bracket 11 is made of heat-resistant, non-8I electrically conductive synthetic resin, and is provided with a pair of opposing stays 12, 12 that protrude upward at one end. A movable plate 14 is pivotally supported on the opposing stay 12° 12 via a shaft 13. The resistor 8a has -ra81 fixed to the movable plate 14, and the other end 8
2 is fixed to one of the stays 12, and flexible conductors 1115 and 16 are fixed to these ends by caulking or the like.
It is connected to the fan speed selector switch 7 through the fan speed selector switch 7.

The spiral resistor 8a is contracted when not energized, and the movable plate 14 is connected to the bracket 11 as shown in FIG.
Hold it in contact with the For this reason, movable plate 1
4 covers the resistor 8a and extends into the recess of the scroll casing 9, thereby defining a flat ventilation path surface. Further, a spring 17 is installed between the movable plate 14 and the bracket 11,
This ensures the return and retention of the movable plate 14 when the resistor 8 is not energized.

Next, the operation of the resistor in the above embodiment will be explained.

When the speed of the air blower 112 is in the high speed (Hl) mode, the movable contact of the changeover switch 7 is connected to the end 81 of the resistor as shown in FIG.
It acts directly on the electric motor 2b without passing through. Therefore, the resistors 8a and 8b do not generate heat, the movable plate 14 remains closed, and the air discharged from the impeller 2a of the blower smoothly flows down toward the air peace equipment as shown by the arrow in FIG. As a result, there is no pressure loss due to the resistor, especially in the high-speed mode that requires the most amount of air flow, and it is possible to ensure a sufficient amount of air flow and to operate the air conditioner with low noise.

On the other hand, when the switch 7 is switched to the medium speed (Met) or low speed mode, one or both of the resistors of the resistor 8 is energized, and the temperature of the resistor rises above the transformation point. Therefore, the resistor expands and pushes up the movable plate as shown in FIG. 5, exposing the resistor. Sending Jil1
The air flow from 2 is directed along a movable plate 14,
It cools the resistor and flows out. Therefore, sufficient heat dissipation of the resistor is ensured during energization.

In the above-mentioned embodiment, the recess of the casing is opened and closed by a movable plate, but next, a second embodiment of the present invention that does not use a movable plate will be described with reference to FIGS. 6 and 7. Since the second embodiment differs from the previous embodiment only in the resistor 108, only the different parts will be explained here, and the other components will be given the same reference numerals as in the first embodiment and detailed. Further explanations will be omitted.

Also in this embodiment, the resistor 108 is connected to the scroll casing 1.
It is placed in a recess provided in the downstream part of the blower of 09,
The resistor 108a is made of a shape memory alloy as in the first embodiment. The resistor 108a is formed into a coil shape and heat-treated so that it largely expands upward and protrudes into the ventilation path 1 during heating transformation. Therefore, when the blower 2 is in high speed mode and the resistor 108 is not energized, the resistor 10
8a is hidden in the recess of the scroll casing 109. Therefore, the resistor 108 does not act as ventilation resistance and reduce the ventilation performance of the air conditioner. When the medium speed generation is in the low speed mode, the resistor 108a is energized as in the previous embodiment. As a result, the resistor 10
8a expands as shown in Figure 7 due to shape change due to heat generation,
It protrudes into the ventilation path 1 and is cooled by the airflow.

8 and 9 show a third embodiment of the invention. Also in the description of this embodiment, the same reference numerals are given to the same constituent parts as in the above-described embodiment, and detailed explanation of these parts will be omitted.

In this embodiment, a resistor 208 is disposed between the evaporator 3 and the heater core 4, and the resistor 208a is attached via a bracket 211 to a recess provided in the casing portion 2o9 on the downstream side of the evaporator. A movable plate 214 is pivotally supported on the bracket 211.

On the other hand, the resistor 208a is formed of a shape memory alloy into a spiral shape, and has one end fixed to the bracket 211 and the other end fixed to the movable plate 214, and drives the movable plate 1-214 during transformation as in the first embodiment. do. However, in the case of this embodiment, the resistor 208a moves the movable plate 214 approximately 1
Largely deformed to pivot over 80 degrees. For this reason, the resistor 208a causes its spiral portion to almost completely protrude into the ventilation passage 1 during heat transformation. In this manner, in this embodiment, the heat-generating portion of the resistor 208a is largely exposed to the air flow in the ventilation passage, and a sufficient cooling effect can be obtained.

Note that in the second and third embodiments described above, only one resistor was described, but any number of resistors may be installed depending on the desired speed classification of the blower. Further, various changes can be made to other embodiments and constituent parts without departing from the gist of the present invention.

(Effect of the invention) As is clear from the above explanation, according to the present invention,
By cooling the heat-generating part of the resistor that adjusts the air flow by protruding it into the ventilation path according to the voltage control operation, the ventilation resistance of the ventilation path is reduced at maximum air flow, which does not require voltage control of the resistor. can be reduced. Also,
At other times of air blowing, the heat generated in the resistor can be sufficiently cooled down. Therefore, it is possible to improve the air blowing performance and quietness of the air conditioner at the maximum air blowing time, and to increase the operational reliability of the air conditioner. Furthermore, by making the heat-generating part of the resistor made of a shape memory alloy, this part can be moved in and out of the ventilation path without providing an additional drive mechanism, and the above-mentioned improvements in performance and reliability can be achieved with a simple structure. This can be achieved at low cost.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the overall configuration of an air conditioner for a car according to a first embodiment of the present invention, FIG. 2 is a cross-sectional side view of the blower portion of the first embodiment, and FIG. 3 is a diagram showing the first embodiment. A drive circuit diagram of the blower according to the example, FIG. 4 is a perspective view showing the resistor part of the first embodiment,
Fig. 5 is a cross-sectional side view showing the state of the resistor portion of the first embodiment when energized, Fig. 6 is a sectional side view of the main part of the air conditioner according to the second embodiment of the present invention, and Fig. 7 is energized. second in time
FIG. 8 is a cross-sectional side view showing the state of the resistor portion of the embodiment, FIG. 8 is a schematic diagram showing the main part of the third embodiment of the present invention, and FIG. 9 is a diagram showing the resistor portion of the third embodiment when energized. It is a schematic diagram showing a state. In the figure, 1... ventilation path, 2... blower,
3... Air conditioner (air conditioning equipment), 4...
...Heater core (air conditioning equipment), 8,108.2
08...Resistor, 8a, 8b, 108a, 20
8a--Resistor (heat-generating part).

Claims (5)

[Claims] (1) A ventilation path for introducing air into the vehicle interior, an air conditioning device including a blower disposed within the ventilation path, and a resistor that controls the drive voltage to the blower to adjust the amount of air blown. At least the heat-generating portion of the resistor is formed of a shape memory alloy, and the resistor is configured such that the heat-generating portion is exposed to the air flow of the ventilation path and cooled by the shape change during heating transformation. An air conditioner for an automobile characterized by installing a container. (2) The automotive air conditioner according to claim 1, wherein the heat generating portion of the resistor is formed to have a transformation temperature slightly lower than the heat generation temperature when energized. Device. (3) In the automotive air conditioner according to claim 1 or 2, the resistor is disposed in a recess provided in a side wall portion of the ventilation passage, and the resistor is configured to open and close the recess. A movable plate is provided, and the heat generating portion is connected to the movable plate so as to drive the movable plate to open and close by changing its shape. (4) In the automobile air conditioner according to claim 3, the heat generating portion is formed in the shape of a coil spring that expands above the transformation temperature and contracts below the transformation temperature, and one end of the heat generating portion is formed in the shape of a coil spring that extends above the transformation temperature and contracts below the transformation temperature. and an air conditioner for an automobile, the other end of which is attached to the bottom of the recess. (5) In the automotive air conditioner according to claim 1 or 2, the resistor is disposed in a recess provided in a side wall portion of the ventilation passage, and the heat generating portion is heated and transformed. An air conditioner for an automobile that is formed into a shape that expands and protrudes into the air flow of the ventilation passage and contracts and fits into the recess during reverse transformation.