JPS6234810Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an air conditioner for automobiles that prevents wasteful energy consumption.

For example, as an air conditioner for automobiles,
As shown in Publication No. 205216, a variable capacity device is installed to change the capacity of the compressor of the cooling cycle, and the temperature setting value that is the reference for switching the variable capacity device and the air mix door that adjusts the amount of air sent to the heater core are installed. A device in which the opening degree is changed according to a predetermined pattern is known.
The amount of adjustment of the variable capacity device is controlled by comparing the temperature setting value with, for example, a detected temperature value of the secondary air that has passed through the evaporator, and the difference between the temperature setting value and the temperature detection value, that is, the heat of the evaporator, is controlled. When the load increases, the capacity is changed to a larger capacity side to obtain appropriate cooling capacity.

However, the cooling cycle is sometimes operated not only for the purpose of cooling, but also for the purpose of dehumidification, and when the air conditioner is turned on during the rainy season or winter and dehumidification is performed in internal air circulation mode, in the conventional example described above, Since the opening degree of the air mix door is adjusted according to the amount of operation of the temperature control lever, the air mix door may be opened from the full cool position depending on the position of the temperature control lever. In this case, the blown air is heated by the heater core, raising the temperature inside the vehicle, and this air is sucked in again and passed through the evaporator one after another, so even if the temperature setting is increased, the heat load on the evaporator is large. As a result, the proportion of compressors operated at large capacity increases. As a result, the air passing through the air conditioner is intensely cooled by the evaporator and then intensely heated by the heater core, resulting in an extremely contradictory heat balance, which has the disadvantage of wasting energy.

Therefore, the purpose of this invention is to prevent wasteful energy consumption even in the above-mentioned cases, and the gist of this invention is that an evaporator and a heater core are arranged in an air conditioning case, An automotive air conditioner comprising a capacity variable device that changes the capacity of a compressor provided in a cooling cycle, and a heating amount adjustment device that adjusts the amount of air heated by the heater core,
A control means is provided for detecting the operation start point of the heating amount adjusting device and forcibly reducing the capacity of the compressor by the variable capacity device to a predetermined value or less when the air heating action occurs. Therefore, when a heating amount adjustment device such as an air mix door is used to generate a heating effect on the heater core, the compressor capacity is always limited to a predetermined value or less by means of a control means, so that the amount of heat generated by operating the compressor at a large capacity is reduced. This eliminates wasteful consumption of energy, thereby achieving the above object.

Examples of this invention will be described below with reference to the drawings.

In FIG. 1, the automotive air conditioner has an inside air inlet 2 and an outside air inlet 3 split into two on the most upstream side of an air conditioning case 1, and an inside/outside air switching door 4 is provided at the divided part. The air to be introduced into the air conditioning case 1 is selected by the inside/outside air switching door 4 between inside air and outside air.

The blower 5 is for sucking air into the air conditioning case 1 and blowing it to the downstream side, and an evaporator 6 and a heater core 7 are provided on the downstream side of the blower 5.

The evaporator 6 constitutes a cooling cycle together with a compressor 8, a condenser 9, a liquid tank 10, and an expansion valve 11.
The heater core 7 is inserted into a hot water cycle in which engine cooling water circulates. The compressor 8
is connected to an engine for driving an automobile via an electromagnetic clutch 12 and a belt transmission device including a pulley 13, and is configured to stop driving by connecting and connecting the electromagnetic clutch 12. Further, the compressor 8 is provided with a capacity variable device 17,
This variable capacity imager 17 has a solenoid 16 in this embodiment, and if the compressor 8 is a vane type, it drives the solenoid 16 to change the number of vanes, or if the compressor 8 is a swash plate type, it changes the number of vanes. The angle of the board can be changed. still,
In addition to this embodiment, the variable capacity device 17 includes:
Any method may be used as long as the amount of discharged refrigerant returned to the suction side is changed, or the pulley ratio of the belt transmission device is changed, or the capacity is substantially changed.

An air mix door 18 is provided in front of the heater core 7, and the amount of air sent to the heater core 7 is adjusted according to the opening degree of the air mix door 18. If the air mix door 7 is opened even slightly from the full cool position shown by the solid line in the figure, Air is sent to the heater core 7. In addition, heater core 7
A water tap 19 is provided in the hot water circuit, and the amount of hot water to the heater core 7 is adjusted according to the opening degree of the water tap 19. That is, the air mix door 18 and the water tank 19 constitute a heating amount adjustment device 20, which adjusts the amount of air heated by the heater core 7.
The air mix door 18 and the water tap 19 are connected to a temperature control lever 22 via a link mechanism 21, and as shown in FIG. It is beginning to take effect. Incidentally, the heating amount adjusting device 20 may be applied to the air mix door 1 as another embodiment.
8 or only the water tank 19.

The downstream side of the air conditioning case 1 includes an upper outlet 23,
It is divided into a lower air outlet 24 and a defrost air outlet 25 that open into the vehicle interior, and mode doors 26 and 27 are provided in the separated parts.
7 to switch the mode.

The on/off of the electromagnetic clutch 12 is
Control circuit 30 via electromagnetic clutch drive circuit 28
The adjustment amount of the variable capacity device 17 is determined by the output of the control circuit 30 via the variable capacity device drive circuit 29 and the output of the control means 33 interlocked with the temperature control lever 22. controlled. The control circuit 30 is controlled based on the voltage V ₁ at the connection point between the temperature setting device 31 whose resistance value changes in conjunction with the temperature control lever 22 and the thermal load sensor 32 whose resistance value changes according to the detected temperature. These circuits are designed to operate on signals, and an example of their circuit configuration is shown in FIG.

The thermal load sensor 32 is composed of a thermistor or the like, and is designed to detect the fin temperature of the evaporator 6, the temperature or pressure of the refrigerant gas that has passed through the evaporator 6, the temperature of the blown air, or the temperature inside the vehicle, and receives input. The voltage V ₁ can be corrected based on the outside temperature and the amount of solar radiation.

In FIG. 2, the control circuit 30 includes operational amplifiers 34 and 3 that constitute a window comparator.
5, and the input voltage V ₁ is compared with reference voltages V ₂ and V ₃ . Reference voltages V ₂ and V ₃ are generated by resistors 36 to 38, and are set so that V ₂ >V ₃ . In addition, operational amplifiers 34, 35
Capacitors 39 and 4 are connected between the respective input terminals of
0 is connected to provide a predetermined hysteresis. Further, the electromagnetic clutch drive circuit 28 and the variable capacity device drive circuit 29 include transistors 41 and 42 and transistor 4, respectively.
3, 44, and a relay 45 and a relay 46,
Based on the outputs of the operational amplifiers 34 and 35 of the control circuit 30, the energization of the coil 47 of the electromagnetic clutch and the solenoid 16 is controlled to be turned on or off.

That is, when the relationship between the input voltage V ₁ and the reference voltages V ₂ and V ₃ is V ₁ > V ₂ > V ₃ , the operational amplifiers 34 and 35
Both outputs are “L”, and the electromagnetic clutch drive circuit 2
8 transistors 41 and 42 are turned off, so the relay 43 is turned off and the coil 4 of the electromagnetic clutch is turned off.
4 is not energized, and the drive of the compressor is stopped. Further, when V ₂ > V ₁ > V ₃ , the output of the operational amplifier 34 is "H" and the output of the operational amplifier 35 is "L", and the transistors 41 and 42 of the electromagnetic clutch drive circuit 28 are turned on, so that the relay 43 is turned on.
is turned on and the coil 44 of the electromagnetic clutch is energized, but since the output of the operational amplifier 35 is "L", the transistor 4 of the variable capacitance device drive circuit 29 is turned on.
3 is off and the transistor 44 is on, which turns on the relay 46, energizing the solenoid 16, and operating the compressor at a small capacity. Furthermore, when V ₂ > V ₃ > V ₁ , the operational amplifiers 34 and 35
As long as the outputs of both are "H" and the limiting switch 49 of the control means 33 described below is closed, the transistor 43 is on and the transistor 44 is off.
Therefore, relay 46 is turned off and solenoid 1
6 is not energized and the compressor is operated at high capacity.

The control means 33 is constituted by a limiting switch 49 inserted between the emitter of the transistor 43 of the variable capacitance device drive circuit 29 and ground. This limiting switch 49 is opened when the temperature control lever 22 is operated from the intermediate position to the full heat side, that is, when the heating amount adjusting device starts operating, and detects the operating start point, and the heating effect of the air is stopped. If this occurs, the transistor 44 is turned on, the relay 46 is turned on regardless of the output from the control circuit 30, and the compressor is limited to a small capacity.

Note that 50 is an in-vehicle battery, 51 is an ignition switch, and 52 is an air conditioner switch.

In the above configuration, the ignition switch 5
1 and the air conditioner switch 52 are closed, the control circuit 30 starts comparing the input voltage V ₁ with the reference voltages V ₂ and V ₃ . At this time, if the temperature control lever 22 is in the range from the full cool position to the intermediate position, the restriction switch 49 of the restriction means 33 is closed, and the temperature setting device 31 is inversely proportional to the operation amount of the temperature control lever 22. resistance value changes. Therefore, the temperature set by the temperature setting device 31 changes linearly according to the position of the temperature control lever 22, as shown in FIG. , the switching from on to off is the characteristic line
a', switching from small capacity to large capacity of the variable capacity device 17 is carried out according to characteristic line b, and switching from large capacity to small capacity is carried out according to characteristic line b'. Therefore, within that range, the capacity of the compressor 8 is freely controlled depending only on the output of the control circuit 30.

Then, when the temperature control lever 22 is moved from the intermediate position to the full heat side, the link mechanism 21
The air mix door 18 and the water valve 19 are opened via the heating amount adjusting device 20 and the heater core 7 starts heating the air, and at the same time, the limiting switch 49 of the control means 33 is opened. Therefore, the solenoid 16 of the variable capacity device 17 is energized regardless of the output from the control circuit 30, and the solenoid valve 16 is opened to open the compressor 8.
is operated at a small capacity. When the compressor 8 is driven to require a heating effect in this way, it is when the cooling capacity is not required as much, such as when dehumidifying during the rainy season or winter, or when the temperature control lever 22 is operated incorrectly. It is sufficient to operate the compressor 8 at a small capacity to achieve the purpose.

In addition, in the above embodiment, the capacity variable device 10
Although we used a device that switches in two stages, large and small, it is not limited to this, and includes well-known devices that switch in three stages or continuously.
The control means 33 is not limited to fixing the capacity to a small value as in the above embodiments, but may be sufficient as long as it limits the capacity to a predetermined value or less. Furthermore, the control pattern can be modified as necessary, as shown in FIGS. 4 and 5.

As described above, according to this invention, when the heating by the heater core is applied and the compressor is driven, the capacity of the compressor is always limited to a predetermined value or less, so the compressor can be driven at a large capacity. It is possible to prevent wasteful energy consumption due to this, and can contribute to energy saving.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the automotive air conditioner of this invention, Fig. 2 is an electric circuit diagram showing an example of the circuit configuration in the same, Fig. 3 is a characteristic diagram showing the control pattern in the same, Fig. 4, FIG. 5 is a characteristic diagram showing a modification of the control pattern. 1... Air conditioning case, 6... Evaporator, 7...
... Heater core, 8 ... Compressor, 17 ... Capacity variable device, 18 ... Air mix door, 19 ...
...Water tap, 20...Heating amount adjustment device, 2
2... Temperature control lever, 33... Control means, 49... Limiting switch.

Claims (1)

[Claims for Utility Model Registration] 1. An evaporator and a heater core are arranged in an air conditioning case, and a capacity variable device that changes the capacity of a compressor provided in a cooling cycle including the evaporator, and adjusts the amount of heating of air by the heater core. In an automobile air conditioner having a heating amount adjusting device, when the operation start point of the heating amount adjusting device is detected and a heating action of the air occurs, the capacity of the compressor by the capacity variable device is forcibly adjusted to a predetermined value. An air conditioner for an automobile, characterized in that it is provided with the following restriction means. 2. The air conditioner for an automobile according to claim 1, wherein the heating amount adjusting device is an air intake door that adjusts the amount of air sent to the heater core. 3. The air conditioner for an automobile according to claim 1, wherein the heating amount adjusting device is a water tap that adjusts the amount of hot water supplied to the heater core. 4. The air conditioner for an automobile according to claim 1, wherein the heating amount adjusting device comprises an air mix door that adjusts the amount of air sent to the heater core and a water tap that adjusts the amount of hot water sent to the heater core. 5. The air conditioner for an automobile according to any one of claims 1 to 4, wherein the control means comprises a restriction switch that operates in conjunction with a temperature control lever that operates the heating amount adjusting device.