JPS582485A - Method of controlling operation of variable capacity compressor in cooler - Google Patents

Abstract

PURPOSE:To facilitate adjustment of room temperature and prevent any loss of power by changing over capacity of a variable capacity compressor to adjust a damper operating control lever to a predetermined position at first when temperature in a room to be cooled reaches a set temperature. CONSTITUTION:When a compressor 2 has been changed over from 100% to 50% rate of operation, causing shortage of present cooling ability, vehicle room temperature T rises and reaches a set temperature T1(25 deg.C) so that capacity increasing signal is generated from a controller 16 to change over the compressor from 50% to 100% rate of operation. When thus the cooling ability is increased and the temperature T in the vehicle room is again lowered to a set temperature T2(23 deg.C), the compressor is changed over from 100% to 50% rate of operation. Then similarly the capacity is changed over from 50% to 100% or vice versa alternatively. Thus, useless heating of overcooled air is obviated to provide efficient operation of the compressor.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling the operation of a variable capacity compressor, which is particularly suitable for vehicle air conditioning, and is capable of changing its operating capacity in response to load conditions G.

In general, in vehicle cooling systems, a fan, a refrigeration cycle evaporator, a damper, and a heater that uses the engine's cooling water are installed in the duct, and the control of the cabin temperature is controlled by the controller. This is done by operating a lever to rotate the damper. After this step, the temperature inside the vehicle will drop too much unless the damper is adjusted. The defect is that compressor efficiency decreases and power loss increases.

The first object of the present invention is to detect the temperature inside a room to be cooled, such as a single room, and change the capacity of the variable capacity compressor when this temperature reaches the set temperature. By adjusting the control lever to a predetermined position, you can control the indoor temperature for the comfort of the user without changing the settings, and it is also easy to adjust the room temperature, increasing the efficiency of the compressor and increasing the power. An object of the present invention is to provide a method for controlling the operation of a variable capacity compressor in a cooling device that can prevent losses.

The second purpose of non-invention is that when the indoor temperature becomes the set temperature and the temperature change rate is also large, the capacity is reduced, and when the indoor temperature is lower than the set temperature, another setting If the room temperature reaches the set temperature and the operating time from the start of the compressor is shorter than the set time, the capacity will be reduced; if it is longer, the indoor temperature will drop. A different set temperature lower than the set temperature is reached.
In addition to the first objective, we have developed a variable capacity compressor operation control method that can adjust the number of capacity changes according to the cooling load and achieve even more efficient operation. It is about providing.

Hereinafter, a first embodiment of the operation control method that achieves the first object of the invention will be described with reference to FIGS. 1 and 2, in which the method is applied to a vehicle cooling system.

First, an overview of the cooling system used in the control method of this embodiment will be explained with reference to FIG. In the example, the operating capacity is 50% and 100%.
It uses a swash plate type that can be switched to two stages. Of the discharge valves for the discharge ports connecting the front and rear compression chambers and the discharge chamber, this compressor has the gloss side discharge valve always floated in the open position via a spring, and the discharge valve A T capacity switching mechanism 6 is provided on the rear side of the valve so as to maintain the discharge valve in a normal closed position by applying the discharge pressure of the refrigeration cycle. (Japanese Patent Application No. 151298/1989 filed by the same applicant). In addition to this swash plate type compressor, various types of compressors capable of steplessly changing the capacity in three or more stages may be used.

The discharge flange 4 and suction flange 5 of the 111J i6 compressor 2 are equipped with a condenser 6, a receiver 7, an expansion valve 8, and an evaporator 9, which constitute a refrigeration cycle.
are connected in series.

- In the duct 10, a fan 11, the evaporator 9, a damper 12, and a heater 16 that utilizes the cooling water of the engine 1 are arranged in order. Adjust the position of
The temperature of the air blown out from the Suita port 14 of the duct 1-10 can be adjusted as necessary.

In addition, a temperature sensor 1 for detecting the temperature inside the vehicle is installed at an appropriate location in the vehicle interior (preferably a place that is not exposed to wind or direct sunlight).
5 are arranged. A controller 16 is connected between this temperature sensor 15 and the capacity switching mechanism 3, and in this embodiment, a temperature comparison/discrimination circuit (shown in the figure) of this controller sets a preset temperature T2. (For example, 23 degrees Celsius) is compared with the T car room temperature iT detected by the temperature sensor 15, and the car temperature is determined to be 13 [T or the set temperature T2.
When this happens, a capacity down signal is output from the operating circuit (path shown) of the controller 16 to the capacity switching mechanism 6, and conversely, when the cabin temperature T reaches the set temperature T+ (for example, 25°C) , so as to output a capacity up signal to the capacity switching mechanism B.

Further, the controller 16 is electrically connected to an electromagnetic clutch (not shown) of the compressor 2, and the vehicle interior temperature T is set to a set temperature f.
When temperature T4 (e.g. 20°C) is reached, the same control wJA device 16 outputs a signal to turn off the electromagnetic clutch, and when the cabin temperature T reaches the set temperature Ts (e.g. 22p), a signal is outputted to turn on the electromagnetic clutch 4. It's straining.

Temperature Tl″-T4 set by the above control +a16
C. Temperature control switches 17 are arranged so that they can be adjusted in conjunction with each other or independently.
It is possible to set the temperature in a single room to suit the passenger. Further, the relationship T+>T2>T8>T4 is established between these temperatures Tl-T4.

Next, the operation control method of the present invention will be explained based on the single cooling device configured as described above.

Now, when the electromagnetic clutch is turned on from the cold S device start switch (path shown) I, the compressor is started at 50% capacity, and then the discharge pressure rises and the discharge valve moves to the normal closing position G. ! o, it switches from 50% to 100%. The compressed refrigerant gas discharged from the discharge flange 4 is passed through a condenser 6, a receiver 7 and an expansion valve 8.
The air is then sent to the evaporator 9, where it undergoes heat exchange with the air forcibly transferred by the fan 11, and is then sucked into the compressor 2 through the suction flange 5. A portion of the cold air that passes through the evaporator 9 is heated through the heater 13, merges with the cooling air, and is blown out from the outlet 14 to cool the interior of the vehicle.

The cabin temperature T gradually drops by G as the driving time increases by 1 kHz, which is shown in the graph shown in Figure 2. -40°C), and during the initial operation of the compressor, the temperature inside the passenger compartment is still high and the cooling load is high, when heat exchange is performed efficiently and the temperature inside the passenger compartment drops rapidly. Then, as the driving time passes, the cabin temperature T decreases and the heat exchange efficiency decreases, and the drop becomes more gradual, until the cabin temperature T reaches the set temperature T2 (23℃).
), the controller 16 outputs a volume down signal and the capacity switching mechanism 61 changes the compressor from 100% to 50%.
Switched to operation.

Even if the capacity is reduced in this way, if the cooling capacity of the compressor is somewhat large, the temperature in the single compartment E will gradually decrease (as shown by the solid line in Figure 2). When the temperature T reaches the set temperature T4 (20°C), the electromagnetic clutch is turned off and the T compressor, which is operating at 50%, is stopped.After the compressor is stopped, the cabin temperature T rises and the set temperature is reached. When the temperature reaches T3 (22℃), the T clutch is turned on and the compressor is driven again at 50%, and then the same goes back to 0.
% and 50% capacity switching is performed alternately.

On the other hand, when the compressor is switched from 100% to 50% operation and the cooling capacity is insufficient, the cabin temperature T rises as shown by the broken line in Figure 2. When the set temperature (T125°C) is reached, the controller 16 outputs a container up signal and the compressor changes from 50% to 100%. %
Operation mode can be switched. In this way, the cooling capacity increases and the cabin temperature T decreases, and the set temperature piT2 (23'
At c), the compressor is switched from 100% to 50% operation, and thereafter the capacity is alternately switched between 50% and 100%.

As mentioned above, the compressor operation is controlled or
In this case, the cabin temperature T is detected, and when the temperature reaches the set temperature T2, the capacity decreases from 100% to 50%, and when the cooling load is small, the set temperature is lowered. T4. 0% from Tl11.

When 50% capacity switching is performed and the cooling load is large, the set temperature T2. 50% and 100% capacity switching is performed from the Tth point.1 This makes it possible to control the cabin temperature by switching the capacity of the compressor regardless of the position of the damper 12. Once you have set some of them in the correct position, there is no need to make any further adjustments, which eliminates the waste of heating air that is too cold, allowing you to operate the compressor more efficiently and reduce power loss. can.

Further, in the non-inventive embodiment, since the cabin temperature T is detected, the cabin temperature can be easily adjusted to suit the passenger by operating the temperature control switch 17.

Next, a second embodiment that achieves the second object of the present invention will be described as a third embodiment.
The diagram will be explained.

As mentioned above, the vehicle interior temperature T decreases with the passage of driving time as γ, and if this rate of change is θ, it is expressed as γ. This rate of change θ increases as the cooling load decreases, and decreases as the cooling load increases, so for example, if the rate of change θ near the set temperature T2 (23°C) is
By comparing and determining whether this rate of change is larger or smaller than the set rate of change θC, the degree of cooling load can be known. Therefore, in this second embodiment, when the cabin temperature T exceeds the set temperature T2 below the set temperature T2, the detected rate of change θ near the same temperature T2 is lower than the set rate of change θC. When the temperature is large, the capacity is reduced, and when it is small, the set temperature [Ta] is lower than the temperature T2.The temperature change rate θ, θC is
By providing a comparison/discrimination circuit (not shown) and an operation circuit (not shown), capacity switching can be performed quickly when the cooling load is small and there is room for cooling capacity, and when the cooling load is large and there is no room for cooling, the capacity can be switched quickly. , capacity switching is slowed down to prevent frequent switching operations.

In other words, if the capacity is reduced at a point P where the cabin temperature T reaches the set temperature T2 as shown in Figure 3 when there is no room for cooling capacity, the cabin temperature T will decrease as shown by the two-dot chain line in the figure. Capacity is increased at point Q, which is the set temperature T1, but in this third embodiment, capacity is reduced at point R, where the vehicle room temperature 13jT is lower than set temperature T2, which is set temperature T8. is later than point P, and the capacity increase timing at point S is also later than point Q.

Note that if the capacity is excessive even if the capacity is reduced at the set temperature T2, the clutch is disengaged and the compressor is stopped when the cabin temperature T falls to the set temperature T5. When the cabin temperature T rises to the set temperature T4, the clutch is engaged again and the compressor is turned 5.
Runs at 0%.

Next, a third embodiment that achieves the second object of the present invention will be described with reference to FIG.

In this embodiment, a timer counts the time since the compressor starts operating, and this operating time is set in advance.
In a state that is shorter than the set time hc, the capacity of the compressor is reduced when the cabin temperature T reaches the set temperature T2, and when the operating time is over the set time he, The controller 1'6 described in a) is configured so that the capacity of the compressor is not reduced even when the cabin temperature T reaches the set temperature T2, and the capacity is reduced only when the set temperature T8, which is lower than T2, is reached. ing. Therefore, like the second embodiment, this third embodiment also has the feature that it is possible to perform efficient operation by adjusting the switching timing of the capacity down and amplifier according to the cooling capacity. The structure and effects are the same as those of the first embodiment.

Incidentally, the non-invention can also be embodied in the following examples.

(1) Connect a T-type EPR (evaporator pressure regulator) used in higher-end cars to maintain a constant evaporation pressure in the middle of the pipe connecting the evaporator 9 to the suction flange 5. In this case, since the temperature inside the evaporator 9 does not fall below 0°C, the Ta of the first embodiment
T4. T4 of the second and third embodiments. No need to set T5,
The compressor will not turn off unless the cooling start switch is turned off.

(2) A temperature sensor to detect the outlet temperature of the evaporator 9 is installed in the duct 1.
0 and temporarily turn off the compressor before frosting.
to do as you please.

In the above-mentioned embodiment, the constant temperature difference between the set temperatures T+ and T6 is provided to ensure that the capacity switching operation and clutch disengagement operation are performed.

As described in detail above, the present invention allows the temperature of a single room, etc. to be controlled by changing the capacity of the compressor without operating the damper, and also allows the user to adjust the room temperature to the optimum level using the temperature control switch. The temperature can be easily adjusted, the compressor can be operated efficiently to reduce power loss, and the compressor capacity switching timing can be adjusted according to the cooling load, allowing even more efficient operation. There are some effects that can be done.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of a vehicle cooling system used in the uninvented variable capacity compressor operation control method, and FIGS. 2 to 4 show the first to third embodiments, respectively. It is a graph showing the relationship between the operating time of the compressor and the cabin temperature. variable capacity compressor 2, capacity switching mechanism 6, temperature sensor 15,
Controller 16, cabin temperature T, set temperature 1f:'rL~T5,
Temperature change rate θ, setting change rate θ01 operating time, setting time he0 Patent applicant: Toyota Industries Corporation.
Agent Patent Attorney On 1) Hirosen Figure 1 ÷ Ml down 1 - ~ Zeng - 1 - 1! -ml-I Roro OO ,b i6 2'/H To the mouth of the pus ~to 110φ N~~~~-

Claims (1)

[Scope of Claims] l Capacity switching mechanism E sends compressed gas to the refrigeration cycle from a variable capacity compressor whose capacity, that is, cooling capacity can be switched and adjusted according to the cooling load, to perform cooling action.
In the single strain cooling method, the temperature in the room to be cooled is detected by a temperature sensor, and the temperature in the room to be cooled is set in advance so that the gas is sucked into the compressor again after heat exchange.
A comparison and determination means compares and determines the set temperature, and when the indoor temperature reaches the set temperature, the operation means [Komari operates the capacity switching machine P4 to adjust the capacity of the compressor. Operation control method for variable capacity compressor. 2. When the indoor temperature drops to the low setting temperature of the comparison and discrimination means, the operating means switches the compressor to reduce the capacity, and then the indoor temperature rises and the comparison and discrimination means reaches the low setting. Claim 1, wherein the operating means switches the compressor to increase capacity when the temperature rises.
A method for controlling the operation of a variable capacity compressor in a cooling device according to paragraph 1. 3 When the compressor is switched to capacity down, the temperature continues to drop and reaches yet another set temperature lower than the capacity down setting temperature, the driving force is transferred to the compressor.
2. A method for controlling the operation of a variable capacity compressor in a cooling system according to claim 1, characterized in that a clutch of a compressor is disengaged. 4 The set temperature of the T-piece connected to the clutch is set to MU
Variable displacement compression #19) Operation control method in the air conditioner E according to claim 3, characterized in that the temperature is set higher than the set temperature of the T-column at which the latch is disconnected. Claim 1: A method for controlling the operation of a variable capacity compressor in an air conditioner according to claim 1, wherein the variable capacity compressor can be adjusted in conjunction with a temperature control switch. 6 Compressed gas is sent from the capacity switching mechanism (variable capacity compressor power that can switch and adjust the capacity, that is, the cooling capacity according to the cooling load) to the refrigeration cycle to perform cooling action, and after heat exchange is completed, the compressed gas is transferred to the refrigeration cycle. is sucked into the compressor again, the temperature inside the room to be cooled is detected by a temperature sensor, and this detected temperature and a preset value f
The indoor temperature is lowered to the set temperature, and the rate of change of the indoor temperature is compared and determined with a preset rate of change by the rate of change comparison and discrimination means. If the rate of change in the indoor temperature is greater than the set rate of change, the operating means operates the switching mechanism to reduce the capacity of the compressor, and the rate of change in the indoor temperature is greater than the set rate of change. A method for controlling the operation of a variable capacity compressor, characterized in that the capacity of the compressor is reduced when the temperature reaches a set temperature lower than the set temperature when the temperature is small. 7) The capacity switching mechanism is configured to send compressed gas from the variable capacity compressor (ρ), which can switch and adjust the cooling capacity according to the cooling load, to the refrigeration cycle to perform cooling action, and then heat exchange is completed. In the cooling method in which the coke is sucked into the compressor B again, the temperature inside the room to be cooled is detected by a temperature sensor, and the indoor temperature is compared with a preset temperature. Compare and discriminate from this, m
After the temperature in the chamber U has fallen to the set temperature and the compressor starts operating, the timer detects the time, this time is set in advance, and the comparison and discrimination means compares and discriminates this time with the set time. When the operating time is within the set time, the operating means causes the R? The capacity of the compressor is reduced by activating the amount switching mechanism described in J, and when the operating time exceeds the set time, the capacity of the compressor is reduced once the set temperature reaches another set temperature that is lower. A method for controlling the operation of a variable capacity compressor, characterized in that: