Air-Conditioner for an Automotive Vehicle

1. Field of the Invention

The present invention relates to an improved air-conditioner for an automotive vehicle and more particularly to an air-conditioner comprising an air duct, with an air inlet at one end thereof, blowing outlets directed toward the passenger compartment having a ventilation outlet and a floor outlet, a blower provided near the air inlet for introducing the air into an air duct, an evaporator for cooling the air introduced from the blower, a heater core provided downstream of the evaporator with a bypass for part of the air, an air mixing door provided upstream of the heater core so as to adjust the amount of air passing through the heater core, another smaller bypass for introducing some of the heated air passed through the heater core into the floor outlet, and a smaller door located at a heater core to adjust the amount of heated air passing through the other smaller bypass.

2. Description of the Prior Art

A conventional air-conditioner mounted within an automotive vehicle comprises:

(a) an air inlet of a duct located at one end thereof;

(b) a ventilation outlet and floor outlet located at the upper and lower parts of the other end of the duct;

(c) a blower located beside the air inlet introducing the air from the air inlet into the duct;

(d) an evaporator located downstream of the blower cooling the air introduced from the blower;

(e) a heater core located downstream of the evaporator with a bypass provided above the heater core for bypassing some of the air passed through the evaporator;

(f) an air mixing door located upstream of the heater core so as to cover the heater core in its fully closed state to adjust the amount of air passing through the heater core;

(g) an air mixing chamber located downstream of the heater core and the bypass mixing the air cooled by the evaporator which has been passed through the bypass to the ventilation door with the air heated by the heater core in a ratio according to the angle of the air mixing door so as to blow out most of the cooled air through the ventilation outlet and most of the warmed air through the floor outlet, or through a defroster outlet linked to the floor outlet if required.

In the air-conditioner described above, however, the angle of the air mixing door with respect to the heater core determines the air temperature both at the ventilation outlet and at the floor outlet, so that it is difficult to adjust the air temperature only at the ventilation outlet or at the floor outlet. For this reason, there arises a problem that the increased angle of the air mixing door involves the increased temperature in the vicinity of the ventilation outlet in order to raise the air temperature in the vicinity of the floor outlet particularly when both ventilation and floor outlets are opened, so that such air-conditioner cannot provide a comfortable environment within the passenger compartment.

With the above-described problem in mind, it is a primary object of the present invention to provide an improved air-conditioner for an automotive vehicle wherein, in addition to the known elements of the conventional air-conditioner, there are provided a warmed air bypass through which part of the air passed through the heater core is introduced directly into a floor outlet and a smaller air mixing door, in combination with the warmed air bypass, located upstream or downstream of the heater core for opening or closing the warmed air bypass, so that the air from the floor outlet can be at a constant temperature difference from that at the ventilation outlet.

The features and advantages of the present invention will be appreciated from the following description taken in conjunction with the accompanying drawings in which like reference numerals designate corresponding elements, and in which:

FIG. 1 is a sectional view showing a conventional air-conditioner;

FIG. 2 is a sectional view showing an air-conditioner of the first preferred embodiment according to the present invention wherein another smaller door is juxtaposed to the air mixing door, in the maximum heating state;

FIG. 3 is a sectional view showing the first preferred embodiment shown in FIG. 2 in a bi-level air-conditioning state;

FIG. 4 is a sectional view showing the first preferred embodiment shown in FIG. 2 in the maximum cooling state;

FIG. 5 is a sectional view of an air conditioner of a second preferred embodiment according to the present invention wherein the smaller door is provided downstream of the heater core and at the inlet of the second bypass, in the maximum heating state;

FIG. 6 is a sectional view of an air conditioner of the second preferred embodiment shown in FIG. 5 in the bi-level air-conditioning state;

FIG. 7 is a sectional view of an air conditioner of the second preferred embodiment shown in FIG. 5 in the maximum cooling state;

FIG. 8 shows an air conditioner control panel whereby the smaller door is rotated to open or close the second bypass by the manipulation of a mode selection lever;

FIG. 9 shows the relative position of the smaller door when the mode selection lever is placed at the "DEF" position on the control panel in a third preferred embodiment according to the present invention;

FIG. 10 shows the relative movement of the smaller door when the mode selection lever is moved from the "DEF" position to the "HEAT" position on the control panel in the third preferred embodiment;

FIG. 11 shows the relative movement of the smaller door when the mode selection lever is moved to a first end of the "BI-LEVEL" range adjacent to the "HEAT" position in the third preferred embodiment;

FIG. 12 shows the relative movement of the smaller door when the mode selection lever is moved from the first end to a second end of the "BI-LEVEL" range of the control panel in the third preferred embodiment;

FIG. 13 shows the relative movement of the smaller door when the mode selection lever is moved to the second end of the "BI-LEVEL" range of the control panel in the third preferred embodiment;

FIG. 14 shows the relative movement of the smaller door when the mode selection lever is moved to the "VENT" position of the control panel;

FIG. 15 is sectional view of an air conditioner in a fourth preferred embodiment wherein the temperature difference between the air from the ventilation outlet and that from the floor outlet is detected so that the adjustment of the angle of both the air mixing door and the smaller door can be made;

FIG. 16 is a sectional view of an air-conditioner in the fourth preferred embodiment wherein a timer is provided between an amplifier and vacuum transducer; and

FIG. 17 is a graph showing a gradual temperature rise in the floor outlet temperature relative to the ventilation outlet temperature.

Reference will now be made to the drawings, and first to FIG. 1 which is a sectional view of a conventional air-conditioner.

In FIG. 1, numeral 1 denotes a duct having an air inlet 1a at one end thereof and a ventilation outlet 1b and floor outlet 1c linked to a defroster outlet (not shown) at the other end thereof. A blower 2 introducing air from the air inlet 1a into the duct 1 is provided at the air inlet 1a. An evaporator 3 linked to a cooling system (not shown) is provided downstream of the blower 2 cooling the air introduced by the blower 2. A heater core 4 linked to an engine cooling system (not shown) is provided downstream of the evaporator 3 with a first bypass g adjacent to the heater core 4. An air mixing door 5 is provided upstream of the heater core 4 so as to cover one end of the heater core 4 in its fully closed position to adjust the amount of air passing through the heater core 4. An air mixing chamber 6 provides a means for mixing the air that has passed through the heater core 4 with that which has passed through the evaporator 3 and the air bypass g according to the angle of the air mixing door 5. After passing through the air mixing chamber 6, most of the cooled air is blown out from the ventilation outlet 1b while most of the heated air is blown out from the floor outlet 1c.

FIG. 2 shows a first preferred embodiment of the present invention according to the present invention. In the first preferred embodiment shown in FIG. 2, another smaller door 8 is juxtaposed to the air mixing door 5 to adjust the amount of heated air passing into a warm air bypass 7 through the heater core 4. When the air-conditioner is set to its maximum heating state as shown in FIG. 2, both the air mixing door 5 and the smaller door 8 are fully opened so that almost all the air from the blower 2 is passed through the heater core 4, blowing out only from the floor outlet 1c at a required heating temperature. In this case, the smaller door may be fully closed.

In FIG. 3 which shows a bi-level air-conditioning state of the air-conditioner, where the air mixing door 5 is opened to an appropriate angle. According to the angle of the air mixing door 5, the heated air passed through the heater core 4 and the cooled air bypassed around the heater core 4 are mixed in the air mixing chamber 6, the former mostly blowing out from the floor outlet 1b and the latter mostly blowing out from the ventilation outlet 1c into the passenger compartment. In the bi-level state, if the smaller door 8 is opened, the heated air passed through the heater core 4 whose amount depends on the angle of the smaller door 8 is sent directly through the floor outlet 1c. Thus, the temperature of the air from the floor outlet 1c increases as the smaller door 8 is opened. With the smaller door fully open, the difference between the temperature of the air from the floor outlet 1c and that from the ventilation outlet is at a maximum. The temperature of the air from the floor outlet 1c, at this time, is considerably higher than that from a conventional air-conditioner.

FIG. 4 shows the maximum cooling state of the air-conditioner in the first preferred embodiment. In this case, both the air mixing door 5 and the smaller door 8 are fully closed so that the air impelled by the blower 2 is cooled in the evaporator 3 and sent through the first bypass g (not through the heater core 4) to the ventilation outlet 1b.

FIGS. 5 through 7 show a second preferred embodiment according to the present invention. In this preferred embodiment, the air mixing door 5 is rotatably attached to the front of the heater core 4 so as to cover the front of the heater core 4 in its fully closed position, the air mixing door 5 performing the adjustment of the amount of air passing through the heater core 4 and the smaller door 8 located behind and below the heater core (i.e., in front of the second bypass 7) in order to adjust the heated air to be passed through the warmed air bypass 7.

As shown in FIG. 5, the air mixing door 5 is fully opened so that all the air impelled by the blower 2 is passed through the heater core 4 to provide heated air for the floor outlet 1c. (In this state, the smaller door 8 may be in either position shown by either the solid and the dotted lines).

FIG. 6 shows the bi-level air-conditioning state of the air-conditioner in the second preferred embodiment. In this state, the air mixing door 5 is opened to a certain angle so that the air passed through the heater core 4 whose amount depends on the angle of the air mixing door and cooled air passed through the bypass g are sent into the air mixing chamber 6. Therefore, the cooled air is blown out from the ventilation outlet 1b while the warmed air is blown out from the floor outlet 1c. In this bi-level air-conditioning state, the smaller door 8 is opened in the direction marked by an arrow so that some of the air passing through the heater core 4 is sent directly through the floor outlet 1c. Consequently, the air temperature at the floor outlet 1c is raised and as the smaller door 8 is further opened the air temperature at the floor outlet 1c is further raised. With the smaller door 8 fully opened, the difference between the temperature of the air from the floor outlet and that from the ventilation outlet is at a maximum.

FIG. 7 shows the maximum cooling state of the air-conditioner in the second preferred embodiment. In this state, the air mixing door 5 is fully closed so that the heater core 4 is blocked. The air impelled by the blower 2 is cooled by the evaporator 3 not heated by the heater core 4 and is sent out through the bypass g to provide cooled air for the ventilation outlet 1b. (In this state, the smaller door 8 may be open or closed).

FIG. 8 shows the control panel of the air conditioner according to the present invention and FIGS. 9 through 14 show a third preferred embodiment according to the present invention wherein an interlocking device is provided between the smaller door 8 and a mode selection lever 9.

FIG. 8 is a front view of the control panel of the air-conditioner. In FIG. 8, numeral 11 denotes a temperature adjusting lever by which the air mixing door 5 is operated, numeral 12 denotes a fan lever for setting the fan speed, numeral 13 denotes the bi-level temperature control range, numeral 13a denotes the position of the maximum temperature difference between the air from the ventilation outlet and that from the floor outlet, and numeral 13b denotes the position of the minimum temperature difference between the air from the ventilation outlet and the floor outlet.

As shown in FIG. 9, the mode selection lever 9 has a knob 9a at one end thereof and a pin 9b at the other and thereof pivotally supporting the cable 10a of the interlocking device 10 to be described hereinafter. Near the centre of the mode selection lever 9, as shown in FIG. 9, a supporting pin 9c is pivotted on a bearing (not shown in this drawing), the mode selection lever 9 rotating about the supporting pin 9c.

The interlocking device 10 comprises the cable 10a whose one end is pivotally supported about the pin 9b of the mode selection lever 9 and whose other end is pivotally supported about a pin 10b, a rotatable link 10d which rotates about a supporting pin 10c pivotally supported by means of a bearing (not shown in FIG. 9), a rotatable arm 10h with a projection 10f at one end which is fitted into a groove 10e of substantially inversed L shape, and a central part which is supported by means of a bearing (not shown in FIG. 9) on a supporting pin 10g, and a linkage 10k whose one end is provided with a slot 10j into which a projection 10i provided at the other end of the rotatable arm 10h is fitted and whose other end is fixed to the hinge pin 8a of the smaller door 8. (In FIGS. 9 through 14, the smaller door 8 is located upstream of the heater core 4 but may be located downstream of the heater core 4 as shown in FIGS. 5 through 7.)

The action of the air conditioner of the construction described above will now be described.

(1) As shown in FIG. 9, the mode selection lever 9 is placed at the "DEF" position. In this state, the projection 10f of the rotatable arm 10h is at a first end of the groove 10e of the rotatable link 10d so that the smaller door 8 is fixed in its fully closed position.

(2) As shown in FIG. 10, the mode selection lever 9 is moved from the "DEF" position to the "HEAT" position. The rotatable link 10d rotates in the direction of the arrow about the supporting pin 10c through an angle corresponding to the displacement of the mode selection lever 9. Since the shape of the segment 10e.sub.1 of the groove 10e is substantially a circular arc with the supporting pin 10c as its center, neither the rotatable arm 10h nor the linkage arm 10k moves, and the smaller door 8 is maintained in its fully closed position.

(3) As shown in FIG. 11 showing the "BI-LEVEL"(1), the mode selection lever 9 is moved toward the right-hand end 13a of the "BI-LEVEL" range 13 from the "HEAT" position.

Although the rotatable link 10d still rotates counterclockwise, the shape of the segment 10e.sub.2 of the groove 10e is designed to have the longest distance from the center 10c. Consequently, the smaller door 8 is made fully opened by rotating the rotatable arm 10h and linkage arm 10k. In this state, the amount of heated air passing through the second bypass 7 is maximized so that the temperature difference between the air from the ventilation outlet (16) and floor outlet (1c) is at a maximum.

(4) As shown in FIG. 12 of the "BI-LEVEL"(2) and 13 of the "BI-LEVEL"(3), the mode selection lever 9 is moved from the right-hand end 13a to the left-hand end 13b of the "BI-LEVEL" mode range.

The rotatable link 10d rotates counterclockwise about the supporting pin 10c, the angle of rotation depending on the displacement of the mode selection lever 9. The shape of the segment 10e.sub.3 of the groove 10e is designed so that the distance from the center to the groove 10e is gradually decreased. Therefore, as the angle of the smaller door 8 is gradually decreased, the temperature difference between the air from the ventilation outlet 1b and that from the floor outlet 1c becomes smaller. As shown in FIG. 13, when the projection 10f of the rotating arm 10h is positioned at the right-hand end of the segment 10e.sub.3 of the groove 10e, the smaller door 8 is fully closed so that the temperature difference between air from the ventilation and floor outlets is at a minimum.

(5) As shown in FIG. 14, the mode selection lever 9 is moved toward the "VENT" position.

The rotatable link 10d rotates fully counterclockwise about the supporting pin 10c depending on the displacement of the mode selection lever 9. The shape of the segment 10e.sub.4 of the groove 10e is another substantially circular arc to a second end of the groove 10e with the supporting pin 10c as its center. Consequently, neither the rotatable arm 10h nor the linkage 10k rotates and the smaller door 8 is maintained in its fully closed position.

FIG. 15 is an overall block diagram of a fourth preferred embodiment of the air-conditioner according to the present invention which performs the adjustment of the angle of the air mixing door 5 and the smaller door 8 by detecting the difference in air temperature between the ventilation outlet 1b and the floor outlet 1c. In addition to the air-conditioner of the construction described in the first or second preferred embodiment, a first sensor 14 detecting the air temperature at the ventilation outlet 1b, a second sensor 15 detecting the air temperature at the floor outlet 1c, and a door angle adjustment mechanism 16 adjusting the angle of the air mixing door 5 and the smaller door 8 to maintain constant the temperature difference between the air from the ventilation outlet 1b and the floor outlet 1c which is detected by means of these first and second sensors 14 and 15. The door angle adjustment mechanism 16 comprises a first actuator 17 adjusting the angle of the air mixing door 5 according to vacuum pressure; a second actuator 19 adjusting the angle of the smaller door 8 according to vacuum pressure; a first vacuum transducer 18 sending a vacuum pressure according to the level of an electrical signal to the second actuator 19, and an amplifier 21 which calculates the air temperature at the ventilation outlet 1b and at the floor outlet 1c and sends the electrical signal to the first vacuum transducer 18 so as to adjust the angle of the smaller door 8. Numeral 20 denotes a second vacuum transducer which sends vacuum pressure to the first actuator 17 according to the level of an electrical signal from the amplifier 21. Numeral 22 denotes a variable resistor by which the air temperature within the passenger compartment is determined. FIG. 16 shows the air-conditioner shown in FIG. 15 wherein a timer 24 is provided between the first vacuum transducer 18 and the amplifier 21. As a result, the air temperature at the floor outlet 1c is gradually increased as shown in FIG. 17.

According to the present invention, there is provided an air-conditioner whose output of air in the BI-LEVEL mode from the floor outlet is blown out at the level of the floor of the automotive vehicle body at a predetermined higher temperature than that from the ventilation outlet so as to be more comfortable for the occupants.

It will be fully understood by those skilled in the art that the foregoing description is in terms of preferred embodiments of the present invention wherein various changes and modifications may be made without departing from the spirit and scope of the present invention, which is to be defined by the appended claims.