JP2002192937A - Fuel economy-prioritized displacement control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel economy-prioritized displacement control system that permits energy-saving travel while maintaining a comfortable temperature in a cabin. SOLUTION: Function values 13 are allocated in a table 11 according to the rotational frequency N of a variable displacement gas compressor 1 and vehicle speed V. A function value 13 according to an input rotational frequency N and vehicle speed V is outputted. According to the value of the function value 13, a mode switching part 15 switches to break a temperature control part 5 from a control system and thus select control only by a displacement control part 9, or to make the temperature control part 5 as usual and thus let the displacement control part 9 be controlled according to a control signal from the temperature control part 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel efficiency priority type capacity control device, and more particularly to a fuel efficiency priority type capacity control device capable of energy-saving traveling while maintaining a comfortable temperature in a vehicle compartment.

[0002]

2. Description of the Related Art Internal control and external control are conventionally known as capacity control for car air conditioners. In the internal control, the variable capacity mechanism operates in accordance with a change in the suction pressure of the refrigerant, and keeps the suction pressure constant. At this time, the refrigerant pressure and the saturation temperature in the evaporator are kept substantially constant.
As a result, indirectly, the air temperature in the vehicle compartment is kept constant.

On the other hand, in the external control, a sensor detects an air temperature at an evaporator outlet or a vehicle interior, and controls a capacity so that the air temperature coincides with a target temperature. This external control includes not only the case where the air temperature is controlled, but also the case where the target pressure is directly changed and the capacity is mechanically changed based on the difference between the refrigerant pressure and the target pressure.

[0004]

By the way, in internal control, it is possible to simplify the configuration without using a sensor, but it is not possible to positively match the temperature to the target value. Therefore, in order to perform temperature control with higher accuracy, it is necessary to employ external control.However, if control only for following the target value of the control amount can not sufficiently reduce the fuel efficiency of the car Can be considered.

[0005] In particular, when accelerating or the like, there is a case where it is desired to prioritize reduction of energy consumption over controllability of temperature.
In the conventional control method, both the temperature control and the fuel efficiency control cannot coexist.

The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a fuel efficiency priority type capacity control device capable of energy-saving traveling while maintaining a comfortable temperature in a vehicle interior.

[0007]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a temperature control means for compensating a temperature in a vehicle interior based on sensor information and outputting a control signal, and a control signal output from the temperature control means. A variable capacity gas compressor having a capacity changing means capable of changing the volume of the compression chamber, and a load capacity and a vehicle speed of an engine for driving the variable capacity gas compressor or the variable capacity gas compressor. Based on the magnitude, the value of the control signal output from the temperature control means or the value of the signal forcibly supplied from the outside in place of the control signal is close to 0 or 0 which is less than the normal fluctuation range value of the control signal. A table in which whether or not to make the value is tabulated, a load burden detecting means for detecting the load burden, a vehicle speed detecting means for detecting the vehicle speed, and a value detected by the vehicle speed detecting means. Car speed Constructed by a forcing means for the value of such a control signal on the basis of the table from the fine the load burden weight load borne amount detected by the detection means for forcing to zero the like.

The variable displacement gas compressor has displacement changing means. This capacity changing means can change the volume of the compression chamber based on the control signal. The control signal is a signal in which the temperature in the vehicle compartment is compensated based on the sensor information. The temperature in the cabin is an air temperature detected in the cabin or an air temperature detected in the evaporator outlet.

The sensor detects temperature and pressure. The variable displacement gas compressor is driven by the engine mounted on the vehicle. A table is created in advance based on either the load burden of the variable displacement gas compressor or the load burden of the engine and the magnitude of the vehicle speed.

In this table, it is determined whether the value of the control signal should be 0 or a value close to 0 which is less than the normal fluctuation range value of the control signal, depending on the magnitude of the load burden and the speed of the vehicle. ing. If the value of the control signal is not set to 0 or the like, control based on the control signal output from the temperature control means is performed as usual. A signal such as 0 may be forcibly supplied from the outside by switching the control signal.

The values of control signals and the like are forcibly set to 0 or the like based on the table based on the vehicle speed and the load burden. When the value of the control signal is set to 0 or a value close to 0 which is less than the normal fluctuation range value of the control signal, the load on the engine is reduced, which leads to an improvement in fuel efficiency. In addition, since the forced setting at this time is temporary, the influence on the temperature in the vehicle compartment is extremely small.

Further, the present invention releases the driving of the variable displacement gas compressor by the engine when it is determined that the value of the control signal or the like is forcibly set to 0 or the like instead of the forcible setting means. And a drive canceling means.

The transmission of the driving force to the variable displacement gas compressor by the engine is performed by an electromagnetic clutch or the like. When it is determined that the value of the control signal or the like is forcibly set to 0 or the like, the connection by the electromagnetic clutch or the like is released. This reduces the burden on the engine and leads to improved fuel efficiency.

Further, according to the present invention, the load load amount and / or the vehicle speed tabulated in the table are numerically set in a plurality of stages, and a hysteresis is set at a boundary of each stage. It is characterized by.

[0015] By setting the hysteresis, frequent mode switching is not performed upon a change that crosses a boundary.

Further, the present invention is characterized in that the load burden is a rotational speed of the variable displacement gas compressor or the engine, a torque of the engine, a depression amount of an automobile accelerator, and the like.

Further, the present invention is characterized in that input / output means for changing the setting of the table is provided.

By allowing the user to change the setting of the table, the degree of freedom of the user regarding the selection of fuel efficiency is increased.

Further, the present invention comprises command means for instructing whether or not to perform control by each means of the fuel efficiency priority type capacity control device according to any one of claims 1 to 5. .

The user can select whether to give priority to improving the fuel efficiency of the vehicle or to give priority to controlling the temperature in the passenger compartment by using the command means.

[0021]

Embodiments of the present invention will be described below. FIG. 1 shows a configuration diagram of a first embodiment of the present invention. In FIG. 1, a refrigeration system 10 is, for example, an air conditioner of an automobile. The variable displacement gas compressor 1 is mounted on an automobile, and the control plate disposed on the side of the compression chamber is rotated by hydraulic control in the variable displacement gas compressor 1. It has a capacity changing mechanism that can change the volume.

The temperature sensor 3 is disposed, for example, at an air outlet of an evaporator. However, it may be provided in the vehicle interior. The signal detected by the temperature sensor 3 is transmitted to the temperature controller 5
, A deviation from the target temperature 7 is calculated, and temperature compensation is performed based on the deviation signal.

The temperature-compensated signal is input to the capacity control unit 9 as a control signal (duty ratio) of 0 to 1. The displacement control unit 9 converts the control signal into a voltage signal based on pulse width modulation (PWM) and inputs the voltage signal to the displacement changing mechanism of the variable displacement gas compressor 1.

A function value 13 is assigned to the table 11 according to the rotation speed N and the vehicle speed V of the variable displacement gas compressor 1. Then, a function value 13 corresponding to the input rotation speed N and vehicle speed V is output.

The mode switching unit 15 separates the temperature control unit 5 from the control system according to the value of the function value 13 and performs control by only the capacity control unit 9 or, as usual, the temperature control unit 5. The switching of whether or not to control the capacity control unit 9 based on the control signal from the temperature control unit 5 is performed.

The control switching by the mode switching unit 15 is automatically switched according to the value of the function value 13 during the control. GUI17 (Graphical User Interface), which is a man-machine interface,
1 can be changed, and whether or not the mode switching unit 15 can perform the switching control can be selected.

Next, the operation of the first embodiment of the present invention will be described. Table 1 shows an example of the table 11.

[0028]

[Table 1]

In Table 1, the vehicle speed V of the automobile is a low speed,
It is divided into three stages: medium speed and high speed. On the other hand, the rotation speed N of the variable displacement gas compressor 1 is divided into three stages: large, medium and small.

For example, when the rotation speed N is large and the vehicle speed V is low, 0 is assigned to the function value 13. The case where the rotation speed N is large and the vehicle speed V is low is, for example, when the load on the engine is large on an uphill. In this case,
The control system works to minimize the volume of the compression chamber in order to reduce the amount of refrigerant.

However, even with the minimum compression chamber volume taken at this time, the fuel consumption is reduced by the high rotational speed N. In addition, there is a delay in the control system, and the fuel consumption is further reduced. Therefore, in such a case, control switching is performed by the mode switching unit 15 and a control signal of 0 to 0.08 is forcibly sent to the capacity control unit 9.

However, in this example, 0.08 is the minimum value of the normal fluctuation range. That is, when the function value 13 is 0,
The temperature control unit 5 is separated from the control system, and the capacity control unit 9
Only the control is performed. Then, a control signal is forcibly given to the capacity control unit 9.

However, instead of disconnecting the temperature control unit 5 and controlling only by the displacement control unit 9 as described above, the electromagnetic clutch that connects the engine and the variable displacement gas compressor 1 may be released. .

On the other hand, when the rotation speed N is small and the vehicle speed V is high, -1 is assigned to the function value 13. Function value 13
Is -1 as usual, 0 to 1 from the temperature controller 5
Controls the capacity control unit 9 based on the control signal. Table 1 shows a table created by assigning such a function value 13 for all combinations of the vehicle speed V and the rotation speed N.

The table 11 does not always output a constant value determined from finite rows and columns, but may output a continuous value according to the result of estimating conditions using fuzzy or the like. There is. In realization, the capacity control unit 9 and the temperature control unit 5 are distinguished from each other, and the function values are not limited to the above-described function values as long as a target value can be designated.

In FIG. 1, a table 11 outputs a function value 13 corresponding to the input rotation speed N and vehicle speed V. Then, based on the function value 13, the mode switching unit 1
Switch 5. The settings of the table 11 can be changed by the GUI 17.

As described above, it is possible to select whether to give priority to running with priority given to improving the fuel efficiency of the automobile or to give priority to controlling the temperature in the passenger compartment. Even when control is performed with priority given to fuel efficiency, the state in which the function value 13 is 0 is temporary, so that the effect on the temperature in the vehicle compartment is extremely small.

The temperature control unit 5 is usually designed as a compensator based on control theory, and may be realized by an electronic circuit or may be embodied as a computer program.
A function may be realized by executing the program.

The capacity control section 9 may or may not have a feedback function therein. When the feedback function is provided, the approximate value corresponding to the capacity is output as it is, and when the feedback function is not provided, the capacity or a physical quantity in place of the capacity is detected, and the deviation between the capacity target value and the detected value becomes zero. The operation amount is calculated and output. This calculation function is designed as a compensator based on the control theory.

Regardless of the case where the feedback function is provided, the case where the capacity control unit 9 is realized by an electronic circuit, and the case where the function is realized by executing the same program as a computer program There is. This is the same for the mode switching unit 15 and the table 11.

Next, the operation of the second embodiment of the present invention will be described. If there is a possibility that smooth control may be hindered by discontinuous switching at the boundary value in the table 11, the boundary is provided with hysteresis. Table 2 shows an example in which the vehicle speed boundary value has hysteresis.

[0042]

[Table 2]

[0043] In Table 2, the vehicle speed boundary value when proceeding to medium speed low speed was v _lm, vehicle speed boundary value when going from medium speed to low speed in the opposite to the v _ml. And v _lm to v
Set to more than _ml . Thus, when traveling from a low speed to a medium speed, the boundary value is high, and when traveling from a medium speed to a low speed, the boundary value is low, and frequent mode changes near the boundary can be prevented. .

Hysteresis is similarly provided for medium to high speeds and high to medium speeds. At this time, v _mh ≧ v
and _hm ≧ _{v lm} ≧ _{v ml.} However, more classes may be provided.

Next, similarly to the case where the hysteresis is provided on the vehicle speed side, the rotation speed side of the variable displacement gas compressor 1 is shown in Table 3 as well.
Hysteresis is provided as follows.

[0046]

[Table 3]

[0047] In this _{case, n ml ≧ n lm ≧ n} sm ≧ n
_ms . As described above, it is possible to prevent the mode from being frequently changed when the vehicle speed V and the rotation speed N increase or decrease near the boundary of the table 11.

[0048]

As described above, according to the present invention, the table is used to switch whether or not to perform control via the temperature control means depending on the magnitude of the load burden and the vehicle speed. As a result, energy-saving driving and the realization of a comfortable space can be achieved at the same time.

Further, since an input / output means for changing the setting of the table is provided, an environment space suitable for the user's preference can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Variable displacement gas compressor 3 Temperature sensor 5 Temperature control unit 7 Target temperature 9 Capacity control unit 10 Refrigeration system 11 Table 13 Function value 15 Mode switching unit

Claims (6)

[Claims] 1. A temperature control means for compensating a temperature in a vehicle interior based on sensor information and outputting a control signal, and a capacity change capable of changing a volume of a compression chamber based on a control signal output from the temperature control means. Means for controlling the temperature based on the load capacity of the variable capacity gas compressor or the engine for driving the variable capacity gas compressor and the vehicle speed based on the magnitude of the vehicle speed. It is tabulated whether the value of the control signal output from the control signal or the signal forcibly supplied from the outside in place of the control signal is set to 0 or a value close to 0 which is less than the normal fluctuation range value of the control signal. Table, and a load-bearing amount detecting means for detecting the load-bearing amount,
The value of the control signal or the like is set to 0 based on the table from the vehicle speed detecting means for detecting the vehicle speed, and the vehicle speed detected by the vehicle speed detecting means and the load burden detected by the load burden detecting means. And a forced setting means for forcibly setting the fuel consumption priority type. 2. A drive canceling means for canceling the driving of the variable displacement gas compressor by the engine when it is determined that the value of the control signal or the like is forcibly set to 0 or the like instead of the forced setting means. The fuel efficiency priority type displacement control device according to claim 1, further comprising: 3. The load load amount and / or the vehicle speed tabulated in the table are numerically set in a plurality of stages, and a hysteresis is set at a boundary of each stage. The fuel efficiency priority type capacity control device according to claim 1 or 2. 4. The variable load type gas compressor or the engine according to claim 1, wherein the load share is a rotational speed of the variable displacement gas compressor or the engine, a torque of the engine, a depression amount of an automobile accelerator, and the like. The fuel efficiency priority type capacity control device described in the above. 5. An apparatus according to claim 1, further comprising an input / output means for changing the setting of said table.
The fuel efficiency priority type capacity control device described in the above. 6. A fuel consumption priority type capacity control apparatus according to claim 1, further comprising command means for commanding whether or not to perform control by each means. Item 7. A fuel-consumption-priority-type capacity control device according to item 1, 2, 3, 4, or 5.