Device for operating a damper in an air conditioning system for a vehicle

The apparatus for controlling a damper in an air conditioning system for a vehicle. The damper is used for selectively opening air outlets, and is constructed as a film damper having one end wound on a drive shaft rotatably supported in a casing. The drive shaft is formed as a hollow shaft having an axial bore therein, in which an electric motor with a reduction gear is arranged. The outer body of the motor is fixedly inserted to the shaft, and has an output shaft fixedly connected to the casing, so that a rotation of the motor causes a relative rotation between the motor body connected to the hollow shaft and the outlet shaft connected to the casing. As a result of the rotation of the motor body, the drive shaft is rotated, resulting in a desired movement of the film damper.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a device for operating a damper in an air 
conditioning system for a vehicle. 
2. Description of Related Art 
Known in the prior art is an air conditioning system for a vehicle provided 
with a casing having a plurality of outlets for discharging flows of air 
into a cabin of the vehicle, dampers for selectively opening or closing 
the outlets, and a rotary drive device for each respective damper. See 
Japanese Unexamined Patent Publication No. 1-141116. The rotary drive 
device comprises an arm holding the damper at one end thereof, a shaft to 
which the other end of the arm is fixedly connected, a lever connected to 
the shaft at an end thereof remote from the arm, and an actuator 
associated with and obtaining a rotary movement of the lever. Usually, an 
actual arrangement of the air conditioning system in a vehicle will 
require the provision of a link mechanism between the lever and the 
actuator, for transmitting the movement of the actuator to the lever, and 
further, the lever, the actuator and the link mechanism will be arranged 
outside the casing of the air conditioning apparatus, but such an 
arrangement of the lever, the actuator, and the link mechanism outside the 
casing is disadvantageous, in that the system occupies a substantial space 
when mounted in the vehicle. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provided a device for operating a 
damper in an air conditioning apparatus for a vehicle, by which the space 
required for mounting the system in the vehicle is reduced. 
According to the present invention, a flow control apparatus is provided 
for an air-conditioning system for a vehicle, for controlling a flow of 
air from an air flow source to a receiver of the flow of air, the flow 
control apparatus comprising: 
a casing defining therein a passageway having one end connected to the air 
flow source and the other end connected to the air flow receiver; 
a damper arranged in the passageway for controlling the degree of opening 
of the passageway, and; 
drive means for operating the damper, the drive means comprising a hollow 
shaft rotatably connected to the casing, the hollow shaft defining therein 
an axially extending bore and being connected to the damper, and a motor 
arranged in the bore and having a body and an output shaft rotatable to 
the body, the output shaft of the motor being connected in relation to the 
casing, and the motor body being fitted to the hollow shaft, whereby an 
energization of the motor body obtains a relative rotation of the body and 
the output shaft, which allows the hollow shaft to be rotated with respect 
to the casing, to thus move the damper for an operation thereof. 
According to the present invention, a motor rotating the damper is arranged 
inside a drive shaft rotatable with respect to the casing. Namely, the 
entire drive apparatus is housed in the casing, and as a result, a space 
required for storing the air-conditioning system inside the vehicle is 
considerably reduced.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Embodiments of the present invention will be described with reference to 
attached drawings. FIGS. 1 to 3 show a first embodiment of the present 
invention; FIGS. 1 and 2 show the drive device, and FIG. 3 shows an entire 
view of the drive device for a damper when in an air conditioning 
apparatus for a vehicle. The air conditioning apparatus 1 has a casing 2 
to which a blower 11 is connected, and an evaporator 12 and a heater core 
13 are arranged in the casing 2. The blower 11 generates an air flow 
directed to a cabin (not shown) of the vehicle. The evaporator 12 is 
located in a stage of a refrigerating cycle in such a manner that a heat 
exchange of the air flow with the cooling medium passing inside the 
evaporator 12 is carried out, for cooling the air flow. The heater core 13 
has an inner passageway (not shown) connected to a water jacket of an 
internal combustion engine (not shown), so that a hot engine cooling water 
from the water jacket is introduced into the inner passageway of the 
heater core 13, whereby a heat exchange of the air flow to the engine 
cooling water is carried out to warm up the air flow and obtain a desired 
temperature of the air. An air mix damper 14 is arranged upstream of the 
heater core 13, for controlling the ratio of the amount of air passing 
through the heater core 13 to the amount of air by-passing the heater core 
13, so that a desired temperature of air is obtained after the hot air is 
mixed with the cool air. 
The casing 2 is further provided with a ventilation air outlet 21, a side 
ventilation outlet 22, a defroster air outlet 23, a heat air outlet 24, a 
front heat air outlet 25, a rear heat air outlet 26, and a cool air 
by-pass 27. The ventilation air outlet 21 generates an air flow mainly 
directed to an upper half part of a passenger; the side ventilation air 
outlet 22 generates an air flow directed to the side windows of the 
vehicle and the side of a passenger near the side window; the defroster 
air outlet 23 generates an air flow directed to a front window of the 
vehicle; the heat air outlet 24 directs a flow of hot air to the front 
heat air outlet 25 and rear heat air outlet 26; the front heat air outlet 
25 issues a flow of air toward the feet of a passenger; and the rear heat 
air outlet 26 discharges a flow of air toward the rear passenger seats of 
the vehicle. The cool air by-pass 27 is a passageway that is opened or 
closed by a damper (changeover valve) 28 for introducing the cooled air 
from the evaporator 12 directly into the ventilation air outlet 21 and the 
side ventilation air outlet 22. The degree of opening of the ventilation 
air outlet 21, the defroster air outlet 23, and the heat air outlet 24 are 
respectively controlled by a film damper 3 that is moved in the casing 3 
in such a manner that the damper 3 faces the outlet 21, 23 and 24. 
The film damper 3 is made of, for example, a flexible polyethylene resin 
and is connected at both ends thereof to a drive means 4. The film damper 
3 has an intermediate portion supported in a stretched manner by a 
plurality of spaced rolls 31 rotatably supported by the casing 2, and 
having a plurality of openings 32 formed therein for selectively opening 
the outlets 21, 23 an 24, respectively. As shown in FIG. 1, the drive 
means 4 comprises a drive shaft 5, an electric driving motor 6, a driven 
shaft 41 (FIG. 3), a drive belt 42, and an idler shaft 43. The electric 
motor 6 is constructed by a motor body 6a and a speed reduction gear 62. 
The hollow drive shaft 5 constructs a supporting shaft of the present 
invention, and is rotatably arranged between a first cap 7 and a second 
cap 8. The drive shaft 5 is made of a resin material, such as an ABS resin 
or polyethylene resin, and has an axial bore 55 formed therein in which an 
electric motor 6 is arranged, a sleeve 53 made of a rubber material, and a 
spiral tension spring 54. An end of the film damper 3 is wound on the 
drive shaft 5 when the shaft 5 is rotated in the counter clockwise 
direction in FIG. 3. The end of the film damper 3 is fixed to the outer 
periphery of the drive shaft 5 by, a holder 56 and a plurality of lugs 57. 
One end of the holder 56 is engaged with hooks 58 projected from the outer 
periphery of the drive shaft 5, to thereby press against and hold the end 
of the film damper 3. The end of the film damper 3 is a provided with a 
plurality of holes 33 in which the respective lugs 57 on the outer 
periphery of the drive shaft 5 are fitted. 
The sleeve 53 is made of a synthetic rubber material and is used not only 
for fixedly holding the electric drive motor 6 in the drive shaft 5 but 
also for preventing a vibration of the motor 6 and a generation of noise 
therefrom. 
The tension spring 54 is connected at one end to a flange portion 61a of 
the shaft 61, and at the other end is connected to the second cap 8. The 
tension spring 54 generates a torque for rotating the shaft 5, so that the 
shaft 5 stretches the film damper 3 under a tension of, for example, 0.3 
kg to 0.4 kg, and as a result, a film damper 3 is maintained without slack 
therein when moved in the casing 2. 
The electric motor 6 is an element of the present invention, and can be a 
direct electric current motor or a stepping motor. The reduction gear 62 
of the electric motor 6 is a planetary gear type used for reducing the 
rotational speed of an output shaft 61 to a desired value. The output 
shaft 61 is connected to the second cap 8 via the tension spring 54. 
Furthermore, the electric motor 6 is provided with two terminals 63 and 
74, projecting from the left-hand end of the motor 6 in the drawing. 
The first cap 7 is made of a polyprophylene resin, for a one-touch snap on 
and off connection at an opening 29 formed in the casing 2. The first cap 
7 is formed with a plurality of hooks 70 engaged with an inner edge of an 
opening 29 of the casing, and further, is provided with an annular slit 
7-1 to which the end of the tubular shaft 5 is inserted. The first cap 7 
is also provided, by an insert moulding process, with an annular electric 
contact (slip ring) 73 and a central electric contact 74 with which the 
electrodes 63 and 64 extending from the motor 6 are in sliding contact 
respectively when the device is assembled. The terminal 63 is linearly 
extended axially, to be brought into contact with the annular contact 73 
at a predetermined radial position with respect to the axis of the shaft 
5, whereby a contact between the contact 73 and the terminal 63 is 
obtained by a circular movement caused by a relative movement of the motor 
6 and the casing 2. Conversely, the terminal 64 has a separate angle 
member 64' which is in contact with the contact 74 at the axis of the 
shaft 5. As a result, the contact 74 is maintained a constant position on 
the axis and is brought into electrical contact with the terminal 64' by a 
relative movement of the motor 6 and the casing 2. Such an arrangement of 
the terminals 63 and 64 of the electric motor 6 with respect to the 
annular contact 73 and the central contact 74 causes an electrical closed 
circuit to be created while allowing a relative rotation of the motor 6 
and the casing 2. 
The second cap 8 is made of a polyprophylene resin, for a one-touch snap on 
and off connection with the casing 2. Namely, the second cap 8 is formed 
with a pair of projected catches 80 which are inserted to and engaged with 
edges of respective openings 29' formed in the casing 2. The second cap 8 
is further provided with a boss portion 8-1 freely insertable to the end 
of the shaft 5 to which the end of the tension spring 54 is connected. 
As shown in FIG. 3, the driven shaft 41 is rotatably supported by the 
casing 2, and the second end of the film damper 3 is connected to the 
driven shaft 41 in the same way as the first end of the damper 3 is 
connected to the drive shaft 4. When the driven shaft 41 is rotated in the 
clock wise direction in FIG. 3, the second end of the film damper 3 is 
wound on the shaft 41. As is easily understood, the drive shaft 5 can 
transmit a driving force therefrom to the driven shaft 41 by way of a 
drive belt 42 looped around the drive pulley portion 5a on the shaft 5, a 
pulley portion 41a on the driven shaft 41, and an idler shaft 43. The 
idler shaft 43 is rotatably supported on the casing 2, to stabilize the 
tension of the drive belt 42. 
The operation of the device according to the present invention will be 
described with reference to FIGS. 1 to 3. When the electric motor 6 is 
energized, the rotation thereof is transmitted, via the planetary gear 
type reduction gear, to the output shaft 61, to thus reduce the speed of 
rotation thereof. The rotation of the output shaft 61 causes the tension 
spring 54 to be wound around the outer surface of the output shaft 61, and 
the winding of the tension spring 54 is continued until a locked situation 
is obtained such that the output shaft 61 is mechanically connected to the 
second cap 8, i.e., the casing 2. The body 6a of the electric motor 6 is 
connected to the drive shaft 5 via the sleeve 53 made of a rubber 
material, so that a relative rotation of the body 6a of the electric motor 
6 together with the drive shaft 5 is obtained with respect to the output 
shaft 61, and as a result, one end of the film damper 3 is wound about the 
outer surface of the drive shaft 5. The rotation of the drive shaft 5 is 
transmitted to the driven shaft 41 via the belt 42, which causes the film 
damper 3 to be moved in the direction of the shaft 5 while facing the air 
outlets 21, 23 and 24. The motor 6 is de-energized when the opening 32 of 
the film damper 3 coincides with a desired air outlet, whereby cooled air 
or hot air is directed into the cabin from the desired air outlet aligned 
with the opening 32. 
In the above construction, the entire drive device 4 for moving the film 
damper 3 in the casing 2 while facing the air outlets is housed in the 
casing 2, and as a result, the conventional link mechanism or actuator, 
which otherwise would be arranged outside the casing 2, can be eliminated 
according to the present invention, thus enabling the space required for 
mounting the vehicle air conditioning system 1 to be reduced, compared 
with the prior art. 
FIG. 4 shows a part of FIG. 1, and illustrates another embodiment of the 
drive device according to the present invention. The drive means 4 in FIG. 
4 includes a potentiometer 91 arranged between the electric motor 6 and 
the first cap 7. The potentiometer 91 has an input shaft 7a connected to 
the motor 6 via an end 5' of the shaft 5, for imparting a rotational 
movement to the potentiometer 91. Slip rings 73' and 74' are 
insert-moulded into the end 5'. The potentiometer 91 detects an angular 
position of the rotating motor 6 and outputs an electric signal indicating 
the position at which the film damper 3 is to be stopped, to thereby 
increase the precision of the positioning of the damper 3. As a result, it 
is possible to prevent a stopping of the opening 32 of the damper at a 
position not in register with the desired outlet, and therefore, a desired 
air flow can be obtained from the outlet. 
It should be noted that the first cap 7 is provided, by the insert moulding 
process, with terminals 75 for wires 73" and 74" to the slip rings 73' and 
74' and the potentiometer 91, and terminals 76 for connection to a power 
supply (not shown). 
FIGS. 5 to 8 show a third embodiment of the present invention. In FIG. 5, 
showing the drive device 4, in place of the tension spring 54 used in the 
first embodiment shown in FIG. 1, a coupling member 92 made of a block of 
a rubber material is used, and a potentiometer 93 is arranged between the 
coupling member 92 and the second cap 8. Furthermore, as shown in FIG. 7, 
the respective motors 6 are stored at both ends of the film damper drive 
shafts 5. It should be noted that the second cap 8 is provided therein 
with three insert moulded terminals 81 for connection to the potentiometer 
93. In FIG. 6, in addition to the film damper 3 for controlling the flow 
of air to the ventilation outlet 21, the defroster outlet 23 and the hear 
air outlet 24, as also shown in FIG. 1, a film damper 30, which acts as 
the air mix damper 14 in FIG. 1, is provided for controlling the ratio of 
the amount of air introduced into the heater core 13 to the amount of air 
by-passing the heater core 13. The construction of the film damper 30 is 
the same as that of the film damper 3. Namely, the film damper 30 as the 
air-mix damper is connected at both ends to drive shaft 5 having the same 
construction as shown in FIGS. 5 and 7. 
FIGS. 9 to 11 show a fourth embodiment of the present invention. The drive 
device shown in FIGS. 9 and 10 is provided with a electric motor 6 and a 
planetary gear type speed reduction mechanism 62 arranged on the 
right-hand side of the axial bore 55 of the drive shaft 5. The outlet 
shaft 61 from the speed reduction gear 62 is connected to a block 61 made 
of a hardened rubber material formed in the second cap 8 by an insert 
moulding process, or is heated and then connected thereto. As shown in 
FIG. 11, the cap 94 is provided with a semi-circular opening 97 to which 
the output shaft 61 of the corresponding cross-sectional shape is 
inserted, to thus connect the shaft 61 to the cap 94, while preventing a 
rotation of the shaft 61 with respect to the cap 94. Furthermore, a 
twisted wire harness 95 and 96 is used for an electrical connection 
between the terminals 63 and 64 of the electric motor 6 and the slip rings 
73' and 74' in the first cap 7, with which wires 73" and 74" from the 
connector 75 come into contact. 
FIG. 12 shows a fifth embodiment wherein the drive means 4 has a hollow 
drive shaft 5 having an axial bore 55 in which an electric motor 6 is 
housed. Similar to the previous embodiments, the motor 6 is constructed by 
a motor body 6a and a planetary gear type speed reduction gear 62. The 
rotation of the electric motor 6 is transmitted via the speed reduction 
gear 62 to the output shaft 61, which is fixed to a portion 2a of the 
casing 2, whereby a rotation of the motor body 6a together with the shaft 
5 is obtained. The shaft 5 is connected to a pulley 102 rotatably 
supported at the casing 2. The pulley 102 is connected, via a wire 103, to 
a pulley 104 rotatably supported by the casing and connected to the driven 
shaft 41. The driven shaft 41 may have the same construction as that of 
the drive shaft 5. One of the wire 103 is wound on the pulley 102 and the 
other end of the wire 103 is wound on the pulley 104. The motor body 6a 
has terminals 63 and 64 from which flexible wires 100 and 101 extend, 
respectively, via an opening 102b formed axially along and through the 
pulley 102 and are taken outside of the pulley 102. A film damper 3 having 
openings 32 for controlling the flow of air at the air outlets (not shown 
in FIG. 12 but arranged as shown in FIG. 3 or 6) is stretched between the 
drive shaft 5 and the driven shaft 41. 
The rotation of the drive shaft 5 causes one end of the wire 103 to be 
wound on to the pulley 102, and accordingly, the other end of the wire 103 
is wound off of the pulley 104, whereby the driven shaft 41 is rotated for 
controlling the flow of air via the air outlets by the damper 3, and thus 
a designated control of the air flow is obtained. 
The above embodiments are all directed to the dampers constructed as a film 
damper 3, but the concept of the present invention can be realized when 
the damper is a plate type having a pivotal axis enabling a rotational 
movement of the plate type damper. Nevertheless, the present invention, 
when realized as a hollow shaft for storing therein a motor, which 
inevitably makes the diameter of the shaft larger, is more advantageous 
when used with the film damper. Namely, due to the large diameter thereof, 
a small rotation of the shaft is sufficient to obtain a desired movement 
of the film damper, to thus obtain a necessary control of the outlet 
opening. Furthermore, when the film damper is wound on the shaft having a 
large diameter, this reduces the load applied to the film, and thus 
increases the durability of the film per se. 
Although embodiments of the present invention have been described with 
reference to the attached drawings, obviously many modifications and 
change can be made by those skilled in this art, without departing from 
the scope and spirit of the present invention.