JP3387231B2 - Superheat control device for air conditioning cycle - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superheat control device capable of maintaining the superheat of refrigerant in a vehicle air conditioner in an appropriate range.

[0002]

2. Description of the Related Art A vehicle air conditioner for increasing or decreasing the discharge capacity of a compressor according to the required cooling capacity is disclosed in, for example, Japanese Patent Laid-Open No. 1-254418. In this type of device, when the outside temperature is low, the required amount of cooling capacity is small, so the discharge capacity of the compressor is set small and the flow rate of the refrigerant decreases.

[0003]

However, when the flow rate of the refrigerant is small, the refrigerant in the air conditioner unit exchanges heat more than necessary to increase the degree of superheat, and the refrigerant returning from the evaporator to the compressor dries. For this reason, the operating noise of the compressor (for example, the opening / closing noise of the valve due to the fluctuation of the pulse pressure of the refrigerant) is easily transmitted to the evaporator side via the refrigerant return line, and the sound leaks from the evaporator into the vehicle interior, resulting in quietness inside the vehicle. May be damaged. In order to reduce the degree of superheat, the opening of the expansion valve upstream of the evaporator may be set to the open side to increase the flow rate of the refrigerant introduced into the evaporator. However, if the expansion valve opening is uniformly set to a large value, the flow rate of the return refrigerant to the compressor increases significantly when the discharge capacity of the compressor increases, and the discharge gas pressure of the compressor rises abnormally. When the discharge gas pressure is high, the amount of heat radiation in the condenser increases, the temperature of the cooling air to the radiator for cooling the engine installed behind the condenser rises, and the temperature of the engine cooling water rises. Also,
The power consumption of the compressor also increases.

An object of the present invention is to provide a superheat degree control device capable of properly controlling the superheat degree of the refrigerant returning to the compressor.

[0005]

1 to 3 showing an embodiment, the invention of claim 1 is a vehicle in which the discharge capacity of a compressor 1 is increased or decreased based on the required amount of cooling capacity. The present invention is applied to a superheat degree control device for an air conditioning cycle, which is attached to an air conditioning system for a vehicle and controls the superheat degree of the refrigerant returned to the compressor 1 from the heat exchanger 6 provided on the low pressure side of the air conditioning cycle. Then, the outside air temperature detecting means 9 for detecting the outside air temperature, the heat absorption amount adjusting means 66, 67 for changing the heat absorption amount of the heat exchanger 6, and the heat when the outside air temperature detected by the outside air temperature detecting means 9 is below a predetermined value. The heat absorption amount control means 6 for controlling the heat absorption amount adjusting means 66, 67 so that the heat absorption amount of the exchanger 6 decreases.
9, 7 and 8, and the heat absorption amount control means 69 so that the heat absorption amount of the heat exchanger 6 increases as the engine speed increases.
The objects 7 and 8 achieve the above-mentioned object by controlling the heat absorption amount adjusting means 66 and 67. The invention of claim 2 is attached to a vehicle air conditioner that increases or decreases the discharge capacity of the compressor 1 based on the required amount of cooling capacity, and is returned to the compressor 1 from the heat exchanger 6 provided on the low pressure side of the air conditioning cycle. It is applied to a superheat control device for an air conditioning cycle that controls the superheat of a refrigerant. Then, the outside temperature detecting means 9 for detecting the outside temperature
And the heat absorption amount adjusting means 6 for changing the heat absorption amount of the heat exchanger 6.
6, 67 and the heat absorption amount control means 69 for controlling the heat absorption amount adjusting means 66, 67 so that the heat absorption amount of the heat exchanger 6 decreases when the outside air temperature detected by the outside air temperature detecting means 9 is less than or equal to a predetermined value.
7, 8 and the heat absorption amount adjusting means short-circuits the refrigerant flow path in the heat exchanger 6, and the bypass path 6
6 has a valve member 67 for opening and closing 6, and the heat absorption control means 6 is provided so that the bypass passage 66 is opened when the outside air temperature is below a predetermined value.
By driving the valve member 67, 9, 7 and 8 achieve the above-mentioned object. The invention of claim 3 is applied to the superheat degree control device of claim 2, a heat exchanger 6 is installed in an air conditioning unit 5 for guiding air into the vehicle interior, and a heat absorption amount control means drives a valve member 67. A power transmission member 75 for transmitting the force from the outside of the vehicle compartment to the inside of the air conditioning unit 5 is provided, and through the drain passage 50 for discharging the water dripping from around the heat exchanger 6 from the inside of the air conditioning unit 5 to the outside of the vehicle compartment. The power transmission member 75 is guided to the inside of the air conditioning unit 5.

[0006]

In the invention of claim 1, when the outside air temperature is below a predetermined value, the heat absorption amount of the heat exchanger 6 increases as the engine speed increases. Even if the discharge capacity of the compressor 1 is small, if the engine speed increases, the flow rate of the refrigerant discharged from the compressor 1 increases and the superheat degree of the refrigerant decreases, but the heat absorption amount of the heat exchanger 6 increases accordingly. If so, the degree of superheat of the refrigerant is maintained in an appropriate range. In the invention of claim 2, when the bypass passage 66 is opened, the heat absorption amount of the heat exchanger 6 decreases. If the opening degree of the bypass passage 66 can be continuously adjusted by the valve member 67, the heat absorption amount of the heat exchanger 6 can be continuously increased or decreased. In the invention of claim 3, the power transmission member 75 is guided into the air conditioning unit 5 by utilizing the drain passage 50 of the air conditioning unit 5. Partition walls that partition the interior and exterior of the vehicle (for example, dash panel D
The power transmission member 75 can be guided from the outside of the vehicle compartment to the inside of the air conditioning unit 5 without adding a through hole to P).

Incidentally, in the section of means and action for solving the above problems for explaining the constitution of the present invention, the drawings of the embodiments are used for making the present invention easy to understand. It is not limited to.

[0008]

【Example】

—First Embodiment— An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows an outline of an air conditioner according to this embodiment, and 1 is a compressor driven by an engine E to compress a refrigerant,
Reference numeral 2 is a condenser for cooling the refrigerant discharged from the compressor 1 with the outside air, 3 is a liquid tank for separating the refrigerant from the condenser 2 into gas and liquid, and 4 is an expansion valve for expanding the high-pressure refrigerant introduced from the liquid tank 3. . The flow direction of the refrigerant is as indicated by the arrow in the drawing as appropriate. The refrigerant that has passed through the expansion valve 4 is introduced into the evaporator 6 in the air conditioning unit 5 and evaporated, and the heat of the air introduced into the air conditioning unit 5 is removed in the evaporation process. The low-pressure refrigerant whose heat has been exchanged by the evaporator 6 is returned to the compressor 1. The compressor 1 is a variable capacity type, and the higher the required cooling capacity, the larger the discharge capacity is set.

The evaporator 6 includes a tank 60 having a refrigerant inlet 60a and a refrigerant outlet 60b, and a heat exchanging portion 6 having a large number of heat exchanging fins (details thereof are omitted).
1 and. As shown in FIG. 2, the inside of the evaporator 6 is divided into four chambers, that is, a first chamber 64a, a second chamber 64b, a third chamber 64c and a fourth chamber 64d by a pair of partition walls 62 and 63, and the inlet 60a is The first chamber 64a and the outflow port 60b communicate with the fourth chamber 64d. The lower ends of the partition walls 62 and 63 reach the lower end of the tank portion 60, and
Has reached the upper end of the heat exchange section 61, and the upper end of the partition wall 63 is set lower than the partition wall 62. A communication hole 65 that connects the second chamber 64b and the third chamber 64c is formed in the lower portion of the partition wall 62.
And a bypass hole 66 that communicates the first chamber 64a and the fourth chamber 64d with each other, and a triangular pyramidal valve body 67 that opens and closes the bypass hole 66 is arranged on the center line of the bypass hole 66.

As shown in detail in FIG. 3, a valve rod 68 is coaxially connected to the valve body 67, and a valve spring 6 is disposed by a coil spring 69 arranged between a flange 680 and a partition wall 62 in the middle thereof.
7 is always urged in the -X direction (the direction in which the bypass hole 66 is closed). The valve rod 68 projects to the outside of the evaporator 6, and has a valve body 67 at the end thereof in the + X direction (bypass hole 66).
A drive device 7 for driving in the direction (opening) is arranged.
The drive device 7 includes a pressure vessel 70, a bellows 71 arranged in a sealed state inside the pressure vessel 70, a drive rod 7 having a base end side connected to the bellows 71 and a tip end side protruding from the pressure vessel 70.
2, an electromagnet 73 for switching connection and disconnection between the drive rod 72 and the valve rod 68, a projection 681 at the end of the valve rod 68, and an engagement piece 74 that is engageable in the axial direction of the drive rod 72. Equipped with. When the electromagnet 73 is excited, the valve rod 68 and the drive rod 72 are attracted to each other, the engagement piece 74 engages with the protrusion 681, and the drive rod 72 can drive the valve rod 68 in the + X direction. When the electromagnet 73 is demagnetized, the engagement piece 74 and the protrusion 681 are separated from each other as illustrated. Further, when the internal pressure of the pressure vessel 70 rises, the bellows 7
1 extends and the drive rod 72 projects from the pressure vessel 70,
When the internal pressure of the pressure container 70 decreases, the bellows 71 contracts and the drive rod 72 is stored in the pressure container 70.

The inside of the pressure vessel 70 is connected to an intake manifold IM (see FIG. 1) via a communication pipe 75. The communication pipe 75 is piped from the intake manifold IM to the inside of the air conditioning unit 5 via the inside of the drain pipe 50 of the air conditioning unit 5. The drain pipe 50 is attached to the evaporator 6 by the dew condensation action during heat exchange.
The water that drips from the surroundings of the vehicle is discharged to the outside of the vehicle compartment, and the tip 501 thereof penetrates the dash panel DP that partitions the inside and outside of the vehicle compartment and projects into the engine room of the vehicle. By using this drain pipe 50 as an insertion path of the communication pipe 75, it is not necessary to provide an extra through hole in the dash panel DP, so that the sound insulation of the vehicle compartment can be prevented from lowering. In addition, it is desirable that the communication pipe 75 has some flexibility.

As shown in FIGS. 1 and 3, electromagnet 73
The excitation and demagnetization of is switched and controlled by the control device 8. The control device 8 controls the operation of each part of the air conditioner (for example, the opening / closing operation of the air mix door), and the output signal of the outside air temperature sensor 9 is input as information for controlling the electromagnet 73. FIG. 4 shows an interrupt processing routine relating to the control of the excitation state of the electromagnet 73 by the control device 8. The control device 8 reads the outside air temperature detected by the outside air temperature sensor 9 in step S1, and determines whether the outside air temperature is below a predetermined value (for example, 15 ° C.) in step S2. When the outside air temperature is below a predetermined value, the electromagnet 73 is excited in step S3,
When the outside air temperature exceeds the predetermined value, the electromagnet 73 is demagnetized in step S4. After that, the interrupt processing is ended.

According to the above processing, when the outside air temperature exceeds a predetermined value, the drive rod 72 and the valve rod 6 are demagnetized by the demagnetization of the electromagnet 73.
8 is released, and the valve rod 68 is held at a position where the bypass hole 66 is completely closed by the force of the coil spring 69 regardless of the pressure of the intake manifold IM. As a result, as shown by arrows Fin, F12, F23, F34, and Fout in FIG. 2, the total amount of the refrigerant introduced to the inflow port 60a of the evaporator 6 is the first chamber 64a, the second chamber 64b, the third chamber 64c,
It is sequentially guided to the fourth chamber 64d and flows out from the outflow port 60b. In this case, all the refrigerant is the heat exchange part 6 of the evaporator 6.
1, the heat absorption amount of the evaporator 6 is large.

On the other hand, when the outside air temperature falls below a predetermined value, the electromagnet 73 is excited, the drive rod 72 and the valve rod 68 are connected, and the valve body 67 is driven according to the pressure of the intake manifold IM. When the rotation speed of the engine E is in the idling region or in the vicinity thereof, the pressure of the intake manifold IM is high, so that the drive rod 72 extends and the valve body 6
7 is driven in the + X direction. For this reason, a part of the refrigerant flowing into the first chamber 64a bypasses the heat exchange section 61 and the fourth chamber 6
4d, which directly reduces the amount of heat absorbed by the evaporator 6. When the outside air temperature is low, the discharge capacity of the compressor 1 is small and the flow rate of the refrigerant guided to the evaporator 6 is reduced.
The degree of superheat of the refrigerant returning to the compressor 1 is appropriately maintained.

Even when the outside air temperature is below the predetermined value, when the engine speed starts to rise from the idling region, the pressure of the intake manifold IM decreases and the drive rod 72 starts to retreat into the pressure vessel 70. The coil spring 69 drives the valve body 67 in the −X direction. As a result, the opening degree of the bypass hole 66 is gradually reduced, and the heat exchange section 6
The refrigerant flow amount bypassing 1 is decreased, and the heat absorption amount of the evaporator 6 is gradually increased. When the engine speed rises to a certain degree, the bypass hole 66 is completely closed, and the bypass amount of the refrigerant becomes zero. When the engine speed increases, the flow rate of the refrigerant introduced to the evaporator 6 increases, but the amount of heat absorbed increases accordingly, so that the degree of superheat of the refrigerant returning to the compressor 1 is appropriately maintained.

The operation of the apparatus of this embodiment is summarized in Table 1 below.
become that way.

[Table 1]

-Second Embodiment- A second embodiment of the present invention will be described with reference to FIG. Note that FIG.
In the above, parts common to those in the configuration of the first embodiment shown in FIGS. 1 to 3 described above are denoted by the same reference numerals, and description thereof will be omitted. FIG. 5 shows a drive unit 7A of this embodiment corresponding to the drive unit 7 of the first embodiment described above. As is clear from the figure, in this embodiment, a piston 77 is slidably fitted to the inner circumference of a cylindrical cylinder 76, and the valve rod 68 is coaxially fixed to the piston 77. The piston 77 is biased in the + X direction by the coil spring 78. Cylinder 76
The pressure of the intake manifold IM (see FIG. 1) is introduced into the interior of the intake manifold IM via the communication pipe 75. Communication pipe 75
Is inserted in the drain pipe 50 of the air conditioning unit 5 as in the first embodiment. Also, the cylinder 7
A stopper 79 facing the left end surface of the piston 77 is formed inside the piston 6. The position of the stopper 79 is determined so that when the valve body 67 completely closes the bypass hole 66, the stopper 79 and the cylinder 77 are in close contact with each other or a slight gap is left between the stopper 79 and the cylinder 77. . The coil spring 69 may be omitted.

An electromagnet 73 is attached to the right end surface of the piston 77. When the electromagnet 73 is excited, the magnetic force causes the stopper 79 and the electromagnet 73 to be attracted to each other, and the piston 77 moves in the −X direction. The excitation and demagnetization of the electromagnet 73 is switched and controlled by the control device 8A based on the outside air temperature detected by the outside air temperature sensor 9. This control procedure is equivalent to the procedure shown in FIG. 4 of the first embodiment, which is modified so that the electromagnet 73 is demagnetized in step S3 and the electromagnet 73 is excited in step S4.

According to the above construction, when the outside air temperature exceeds a predetermined value, the electromagnet 73 is excited and the piston 77 becomes -X.
The bypass hole 66 is closed by the valve body 67. Therefore, the amount of heat absorbed by the evaporator 6 is maintained high. On the other hand, when the outside air temperature is below a predetermined value, the electromagnet 73 is demagnetized, and the piston 77 moves according to the pressure difference between the inside and outside of the cylinder 76 and the force of the coil springs 69 and 78. When the engine speed is in the idling region or in the vicinity thereof, the internal pressure of the cylinder 76 increases, so that the piston 77 moves in the + X direction and the valve rod 68 is pushed out in the + X direction.
The bypass hole 66 opens and the amount of heat absorbed by the evaporator 6 decreases. Even when the electromagnet 73 is demagnetized, when the engine speed increases, the internal pressure of the cylinder 76 decreases, the piston 77 moves in the −X direction according to the degree of decrease, and the opening degree of the bypass hole 66 decreases. The amount of heat absorbed by the evaporator 6 increases. As described above, also in this embodiment, when the outside air temperature is low and the discharge capacity of the compressor 1 is set to be small, the heat absorption amount of the evaporator 6 changes according to the change of the discharge capacity, and the refrigerant returning from the evaporator 6 to the compressor 1 is changed. The superheat of is maintained properly.

The operation of the apparatus of this embodiment is summarized in Table 2 below.
become that way.

[Table 2]

In the first and second embodiments, the outside air temperature sensor 9 serves as the outside air temperature detecting means, the bypass hole 66 and the valve body 67 serve as the heat absorption adjusting means, the coil spring 69, the driving devices 7, 7A and the control. The devices 8 and 8A have a heat absorption control means,
The bypass hole 66 serves as a bypass passage, the valve body 67 serves as a valve member,
The drain pipe 50 constitutes a drain passage, and the communication pipe 75 constitutes a power transmission member. The driving devices 7 and 7A may be provided outside the air conditioning unit 5. The drive devices 7 and 7A may be provided on the engine room side, and a mechanical power transmission member such as a wire cable may be routed from there through the drain pipe 50 into the air conditioning unit 5 to drive the valve element 67.

In the first and second embodiments,
Focusing on the correlation between the outside air temperature and the load of the air conditioner, it is considered that if the outside air temperature is low, the load is low and the discharge capacity of the compressor 1 is set small, and the superheat degree of the refrigerant returning to the compressor 1 is likely to increase. However, the pressure and temperature of the refrigerant returning to the compressor 1 are detected to identify the superheat degree itself, and when the superheat degree is smaller than the proper range, the heat absorption amount of the evaporator 6 is reduced so that the superheat degree is smaller than the proper range. When the value is large, the amount of heat absorbed by the evaporator 6 may be increased.

Third Embodiment A third embodiment of the present invention will be described with reference to FIG. In addition,
In FIG. 6, parts common to those in FIGS. FIG. 6 shows the expansion valve 10 and the evaporator 11 of the air conditioner according to this embodiment. A compressor, a condenser and a liquid tank are arranged on the upstream side of the expansion valve 10 as in the first embodiment, but they are not shown. The compressor is a variable capacity type. The flow direction of the refrigerant is as indicated by the arrow in the drawing as appropriate. The expansion valve 10 is provided with a first pressure chamber 101 and a second pressure chamber 102 partitioned by a diaphragm 100. The pressure of the refrigerant returning from the evaporator 11 to the compressor (not shown) is introduced into the first pressure chamber 101 via the pressure equalizing pipe 12. Second pressure chamber 1
02 communicates with the inside of the temperature sensitive cylinder 14 via the conduit 13.
Inert gas is sealed in the sealed portion from the second pressure chamber 102 to the temperature sensitive cylinder 14, and activated carbon whose amount of inert gas absorbed decreases as the temperature rises is sealed in the temperature sensitive cylinder 14. There is. The temperature sensitive tube 14 is in close contact with the outer circumference of the return line of the refrigerant from the evaporator 11 to the compressor, and its temperature is proportional to the temperature of the refrigerant returning to the compressor.

The diaphragm 100 is connected to a valve body 104 via a valve rod 103, and the valve body 104 is a coil spring 105.
Is urged toward the valve seat 106 side. Diaphragm 1
00 is elastically deformed in the vertical direction in the drawing according to the pressure difference between the pressure chambers 101 and 102, and the valve element 104 and the valve seat 1 are deformed in accordance with the deformation.
The amount of the gap with 06 changes. As the valve body 104 moves away from the valve seat 106, the throttle amount of the refrigerant in the expansion valve 10 decreases and the flow rate of the refrigerant flowing into the evaporator 11 increases.

The coil spring 105 is supported by a support arm 107 opposite to the valve body 104. The diaphragm 100 and the support arm 107 are connected to the load rod 15, and the end portion of the load rod 15 is opposed to the electromagnet 73 of the drive device 7. This drive device 7 is the same as that of the first embodiment, and the engagement and disengagement of the projection 150 of the load rod 15 and the engagement piece 74 are switched by switching the excitation and demagnetization of the electromagnet 73. The excitation and demagnetization of the electromagnet 73 is performed by the controller 8 based on the outside air temperature detected by the outside air temperature sensor 9.
Switching control is performed according to the procedure shown in. The pressure vessel 70 is connected to the intake manifold IM via a communication pipe 75A.
The pressure of is being led.

With the above construction, when the outside air temperature exceeds a predetermined value, the electromagnet 73 is demagnetized and the connection between the drive rod 72 and the load rod 15 is released. In this state, when the degree of superheat of the refrigerant returning from the evaporator 11 increases, the amount of gas released inside the temperature sensing cylinder 14 increases, and the internal pressure of the second pressure chamber 102 of the expansion valve 10 becomes the first pressure chamber 101 side. More than
The diaphragm 100 bends toward the first pressure chamber 101. Therefore, the valve body 104 is separated from the valve seat 106 and the expansion valve 1
The opening degree of 0 increases, the flow rate of the refrigerant guided to the evaporator 11 increases, and the increase in the degree of superheat is suppressed.

When the outside air temperature is below a predetermined value, the electromagnet 73 is excited to connect the drive rod 72 and the load rod 15. When the engine speed is in the idling region or in the vicinity thereof, the pressure of the intake manifold IM is high, so that the drive rod 72 projects from the pressure container 70 and the load rod 15 is driven in the + X direction. Therefore, the force by which the coil spring 105 pushes the valve body 104 toward the valve seat 106 decreases, and the force that urges the diaphragm 100 toward the first pressure chamber 101 increases. As a result, as compared with the case where the outside air temperature exceeds the predetermined value, the degree of increase in the refrigerant flow rate with respect to the increase in the degree of superheat of the refrigerant becomes large, and the excessive increase in the degree of superheat due to the insufficient refrigerant is suppressed. When the outside air temperature is high, the opening degree of the expansion valve 10 is controlled in the closing direction, so that there is no possibility that the refrigerant flow rate becomes excessive and the compressor discharge pressure rises abnormally. When the outside air temperature is below a predetermined value and the engine speed increases, the force pushing the drive rod 72 in the + X direction decreases, the force of the coil spring 105 recovers, and the diaphragm 100 is attached to the first pressure chamber 101 side. The force that acts is reduced. Therefore, there is no possibility that the engine speed increases and the refrigerant flow rate abnormally increases while the opening of the expansion valve 10 is large.

In the present embodiment, the outside air temperature sensor 9 constitutes outside air temperature detecting means.

[0029]

As described above, in the inventions of claims 1 to 3, since the heat absorption amount of the heat exchanger decreases when the outside air temperature is equal to or lower than a predetermined value, the refrigerant is discharged even when the discharge capacity of the compressor decreases. The degree of superheat can be maintained within an appropriate range, and the inconvenience such as noise increase due to the increase in degree of superheat can be eliminated. Focusing on the correlation between the outside air temperature and the discharge capacity of the compressor, the amount of heat absorbed by the heat exchanger is changed depending on whether the outside air temperature is below a predetermined value. The superheat control accuracy can be improved while simplifying. Especially claim 1
In the invention, since the heat absorption amount of the heat exchanger increases as the engine speed increases, the superheat degree of the refrigerant returning to the compressor can be controlled with higher accuracy. According to the second aspect of the invention, the heat absorption amount of the heat exchanger can be reduced by driving the valve member to open the bypass passage. If the opening degree of the bypass passage can be continuously adjusted by the valve member, the heat absorption amount can be easily and continuously changed. According to the invention of claim 3,
The power transmission member can be guided from the outside of the vehicle to the inside of the air conditioning unit without adding a through hole to a partition wall (for example, a dash panel) that separates the inside and outside of the vehicle compartment, thereby preventing a decrease in sound insulation of the vehicle interior.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of an air conditioner according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing the internal structure of the evaporator shown in FIG.

FIG. 3 is a diagram showing a configuration of a device for driving a valve body provided in the evaporator of FIG.

4 is a flowchart showing a procedure of switching control of excitation and demagnetization of an electromagnet by the control device of FIG.

FIG. 5 is a diagram schematically showing a valve body driving device according to a second embodiment of the present invention.

FIG. 6 is a diagram showing an outline of an air conditioner according to a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 compressor 5 air conditioning unit 6, 11 evaporator (heat exchanger) 7 drive device (heat absorption amount control means) (expansion valve opening control means) 7A drive device (heat absorption amount control means) 8 control device (heat absorption amount control means) ( Expansion valve opening control means) 8A Control device (heat absorption amount control means) 9 Outside air temperature sensor (outside air temperature detection means) (superheat degree information detection means) 10 Expansion valve 15 Load rod (expansion valve opening control means) 50 Air conditioning unit Drain pipe (drain passage) 66 Evaporator bypass hole (heat absorption amount adjusting means)
(Bypass path) 67 Valve body (heat absorption amount adjusting means) (valve member) of evaporator 69 Coil spring (heat absorption amount controlling means) 75 Communication pipe (power transmission member)

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-103968 (JP, A) JP-A-4-292747 (JP, A) JP-A-3-175242 (JP, A) Actual development Sho-60- 176910 (JP, U) Actual development Sho 52-56845 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B60H 1/32 621 F25B 1/00 304

Claims (3)

(57) [Claims] 1. A superheat degree of a refrigerant which is attached to a vehicle air conditioner for increasing or decreasing a discharge capacity of a compressor based on a required amount of a cooling capacity and which is returned to the compressor from a heat exchanger provided on a low pressure side of an air conditioning cycle. In the superheat degree control device of the air conditioning cycle for controlling, the outside air temperature detecting means for detecting the outside air temperature, the heat absorption amount adjusting means for changing the heat absorption amount of the heat exchanger, and the outside air temperature detected by the outside air temperature detecting means. when more than a predetermined value, and a heat absorption control means for heat absorption amount of the heat exchanger to control the heat absorption amount adjusting means so as to reduce the heat absorption control means, the higher the engine speed
The heat absorption amount adjusting means so that the heat absorption amount of the heat exchanger increases.
A superheat control device for an air conditioning cycle characterized by controlling the 2. A compressor based on the required amount of cooling capacity.
The air conditioner for vehicles that increases or decreases the discharge capacity of the
From the heat exchanger installed on the low-pressure side of the conditioning cycle,
Air conditioning cycle that controls the degree of superheat of the refrigerant returned to the presser
In the superheat degree control device of the le, the outside air temperature detecting means for detecting the outside air temperature , the heat absorption amount adjusting means for changing the heat absorption amount of the heat exchanger, and the outside air temperature detected by the outside air temperature detecting means is below a predetermined value. When
The heat absorption amount of the heat exchanger to be reduced.
A heat absorption amount control unit for controlling the adjusting unit, wherein the heat absorption amount control unit shortens the refrigerant flow path in the heat exchanger.
A bypass path that is entangled and a valve member that opens and closes the bypass path
And the endothermic amount control means is such that the outside temperature is
The valve member is opened so that the bypass passage is opened when the value is below a certain value.
Control of air conditioning cycle characterized by driving
apparatus. 3. The heat exchanger is installed in an air conditioning unit for guiding air into the vehicle interior, and the heat absorption amount control means transfers the driving force of the valve member from the outside of the vehicle interior to the inside of the air conditioning unit. Is provided, and the power transmission member is guided to the inside of the air conditioning unit via a drain passage for discharging the moisture dripping from the periphery of the heat exchanger from the inside of the air conditioning unit to the outside of the vehicle compartment. The superheat degree control device for an air conditioning cycle according to claim 2, wherein: