JPH041432A - Control of number of revolutions of idling - Google Patents

Abstract

PURPOSE:To prevent the possible occurrence of engine stalling or an unpleasant feeling by inputting the discharge pressure detection information of a continuously variable capacity type compressor together with other vehicle condition detection information in an engine control part to control the number of revolutions of idling. CONSTITUTION:An air filter 32 and an air flow meter 33 are provided on the uppermost stream side of an intake passage 31 communicated to an intake port 25 formed on an engine main body 21, and a throttle valve 34 is prepared on the downstream side of the intake passage 31. In this case, the upstream and the downstream sides of the throttle valve 34 are connected with a by-pass passage 35, and the flow passage area of the by-pass 35 is adjusted with an idling control valve 36. In the idling control valve 36, opening is adjusted by a duty ratio in the electrified time of a solenoid 37. Moreover the duty ratio in the electrified time of the solenoid 37 is decided with an engine control part 41. Various pieces of vehicle condition information 51 - 58 are inputted in the input port 44 of the engine control part 41.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application J] The present invention relates to a method for controlling the idle rotation speed of a vehicle equipped with a continuously variable capacity air conditioning compressor.

[Prior Art] An idle speed control mechanism always optimally controls the idle speed by adjusting the opening degree of an idle control valve provided in a bypass passage of an intake passage. The engine control unit that operates has engine speed,
Cooling water temperature, vehicle speed, etc. are also used as one of the vehicle condition detection information necessary for idle control.
N, OFF signals) are also input.

On the other hand, the compressors used for air conditioning have gone from a fixed capacity type to a stepwise variable capacity type, and now a continuously variable capacity type compressor has also entered the practical stage.

[Problems to be Solved by the Invention] However, in the idle control of a vehicle equipped with the above-mentioned continuously variable displacement compressor, the operating information of the compressor is limited to only ON and OFF signals, as described above, and the actual load If control is performed without providing (torque) fluctuation information at all, the idle control valve opening degree and target rotation speed that were learned during initial idling will not be able to respond to changes in conditions during driving, that is, load fluctuations, and will continue to change in the next cycle. It controls the starting conditions when idling.

In other words, if the load on the compressor decreases due to excessive cooling capacity as the engine speed increases while the vehicle is running, the next idle speed will be much higher than the target value, causing discomfort, and may cause environmental problems. Conversely, if the load on the compressor increases due to changes in the vehicle speed or slow driving due to traffic jams, the idle speed may not reach the target value, which may lead to an unexpected situation such as the engine stopping.

Therefore, it is most desirable to directly grasp the fluctuations in the drive torque applied to the compressor and input this to the engine control unit as load fluctuation information. A definitive torque detection means (sensor) that can be installed has not yet been found.

It is also possible to determine the compressor load fluctuation by a factor other than the drive torque, for example, the detected value of the compressor capacity, but the correlation with the drive torque when the compressor capacity is used as an alternative detection factor is As shown in the figure, although there is a tendency to be roughly proportional, the fluctuation width of the drive torque in the variable capacity region of the compressor is only about 1/2 of the total fluctuation region VCH.

In other words, in the high torque range, the compressor is
This is because the capacity is fixed at 00% capacity and the correlation with the driving torque is completely lost. Moreover, the compressor capacity detection device not only has a complicated structure and is expensive, but it is also extremely difficult to accurately determine the 100% failure point because it cannot allocate detection tolerances.

An object of the present invention is to accurately reflect the load fluctuation of the compressor in controlling the idle rotation speed in a vehicle equipped with a continuously variable displacement compressor.

[Means for Solving the Problems] In order to solve the above problems, the present invention manually inputs various types of vehicle condition detection information and compressor discharge pressure detection information to an engine control section, and the engine control section operates based on the above information. A new technical measure is taken to control the idle speed adjustment means.

The compressor used in the method of the present invention includes all types of compressors having a continuously variable capacity function, such as an oscillating swash plate type, a rotary silk type, and a vane type.

The detection means for outputting the discharge pressure detection information can be selected at will, and the specific pressure derivation part can be set anywhere in the high pressure piping system leading to the discharge of the compressor and from there to the condenser. No problem. Note that it is also possible to employ a simple pressure switch as the detection means, to detect the average median value of the discharge pressure fluctuation region using the pressure switch, and to output the activation signal as discharge pressure discrimination information.

In addition, the function of the idle rotation speed adjusting means is to control the amount of control air and the amount of fuel injection based on the opening degree adjustment of the idle control valve provided in the bypass path, but it is not possible to control the ignition timing via the igniter. It is also possible to replace.

[The discharge pressure of the compressor is almost exactly proportional to the driving torque in the entire range of driving torque fluctuations, and is the most reliable load fluctuation information as an alternative detection factor for the driving torque,
Detection of discharge pressure is incomparably more advantageous than detection of torque in terms of hardware evaluation. In addition, the method of detecting the average median value of the discharge pressure fluctuation region using a pressure switch and outputting the activation signal as discharge pressure discrimination information is a method that detects the actual driving torque by using a simple and inexpensive detection means. It is possible to accurately distinguish between high and low levels, and it can be put to practical use as simple load fluctuation information for compressors.

The compressor load fluctuation (discharge pressure detection) information that substitutes for the drive torque is constantly provided to the engine control unit, along with other vehicle condition detection information, even when the vehicle is running, and the engine control unit Immediately after inputting the fluctuation information, the target rotation speed is predicted, and the idle rotation speed adjustment means is activated to adjust the control conditions during the next idling.

[Example] Below, Figure 1. : An embodiment of the present invention will be specifically described based on the following.

Fig. 1 does not show a rocking swash plate type compressor installed in a vehicle implementing the method of the present invention.
A rotating shaft 4 is rotatably supported by the cylinder block 1 and the front housing 2. A rotary support body 5 is fixed on the rotary shaft 4 in the front housing 2, and a support arm 6 extending toward the rear side of the rotary support body 5 has an elongated hole 6a extending through the distal end thereof. A pin 7 is slidably fitted into the elongated hole 6a, and a rotary drive plate 8 is connected to the pin 7 so as to be tiltable.

A sleeve 9 is slidably fitted onto the rotating shaft 4 adjacent to the rear end of the rotating support 5, and is always urged toward the rotating support 5 by a spring 10, and protrudes from both left and right sides of the sleeve 9. The provided support shaft 9a (only the minus side is shown) is fitted into an engagement hole (not shown) of the rotary drive plate 8, and the rotary drive plate 8 is supported so as to be swingable around the support shaft 9a.

A rocking swash plate 1 is supported on the rear side of the rotary drive plate 8 so as to be relatively rotatable, and a notch 11a provided on the outer edge engages with a through bolt 16, thereby restraining the rotation, and A piston 13 in a bore 12 extending through the block 1 and the swinging swash plate 11 are connected by a piston rod 14. Therefore, the rotational motion of the rotary shaft 4 is converted to the back and forth reciprocating motion of the rocking swash plate 11 via the rotary drive plate 8, and the piston 13 moves back and forth within the bore 12, thereby moving the air from the suction port 3a to the inside of the bore 12. The refrigerant scum sucked into is compressed and discharged to the discharge ¥3b. And the pressure inside the crank u2a and the suction pressure inside the bore 12 of the piston 1
The stroke of the piston 13 changes depending on the differential pressure across the piston 3, and the inclination angle of the rocking swash plate 11 changes. Incidentally, the pressure within the crank chamber 2a is controlled based on the cooling load by an electromagnetic control valve mechanism 15 disposed within a protrusion at the rear end of the rear housing 3.

A detector 18 is disposed on the outer wall of the rear housing 3 to detect the discharge pressure via a pressure guiding hole 17 communicating with the discharge chamber 3b. The detector 18 can be arbitrarily selected; for example, a well-known pressure sensor of the strain gauge type may be used, and the output current value obtained by converting the pressure displacement of the diaphragm with a strain gauge is used as the discharge pressure detection information to detect idle rotation. It is input to the engine control section which controls the number.

Of course, the outlet for the discharge pressure is not limited to the above-mentioned discharge chamber 3b, and may be provided in the high-pressure piping system extending from the discharge port of the compressor (not shown) to the condenser.

The above-mentioned discharge pressure, which substitutes the driving torque as compressor load fluctuation information, is not affected by the variable capacity range of the compressor, but is equal to the driving torque in the entire range of practical driving torque fluctuations shown in Fig. 4. It is almost exactly proportional and is used as the most reliable load fluctuation information. Note that a general pressure switch is adopted as the detector 18, and the pressure switch detects the median value of the discharge pressure fluctuation region (average median value taking into account the operating conditions), and outputs the activation signal to the discharge pressure. It can also be output as discrimination information (Fig. 4). The detected information in this case is dichotomous information that distinguishes the actual state of the drive torque into high and low ranges, but it can be put to practical use as simple load fluctuation information for the compressor.

FIG. 2 shows an idle speed control mechanism in which the compressor discharge pressure detection information outputted by the detector 18 of the present invention is added to one of the vehicle condition detection information.
A piston 23 is movably accommodated in the cylinder bore 22, forming a combustion chamber 24. The intake boat 25 is connected to an intake valve 26 and an exhaust port 27.
are opened and closed by exhaust valves 28, respectively. Intake port 2
A fuel injection valve 29 is disposed near the fuel injection valve 5 . An air filter 32 and an air flow meter 33 are provided on the most upstream side of the intake passage 31 communicating with the intake bolt 25, and a throttle valve 34 is provided on the downstream side thereof. Throttle valve 3
The upstream and downstream sides of 4 are connected by a bypass passage 35, and the passage area of the bypass passage 35 is adjusted by an idle control valve 36. The idle control valve 36 is, for example, a near solenoid valve, and is always connected to the engine control section 41.
The opening degree is adjusted by this, and the idle speed is controlled thereby. The idle control valve 36 is a lenoid 37.
Its opening degree is adjusted depending on the duty ratio of the energization time, and it is closed when the duty ratio is 0%, and the duty ratio is 10%.
When it is 0%, it is fully open.

The engine control unit 41 determines the duty ratio of the energization time of the solenoid 37 of the idle control valve 36, and connects a microprocessing unit (MPU) 42, a memory 43, an input port 44, and an output port 45. It consists of lotus 46. Various vehicle status information, which will be described later, is input to the input port 44, and the output port 4
5 is connected to the solenoid 37 of the idle control valve 36. The MPU 42 determines the duty ratio of the energization time to the solenoid 37 according to the program stored in the memory 43.

51 to 58 are parameters manually entered into the input port 44 as vehicle status information, 51 is a signal corresponding to the engine speed, 52 is an ON signal of the idle switch when the opening of the throttle valve 34 is less than a predetermined value, and 53 54 is a signal that corresponds to the vehicle speed, 54 is a neutral ON signal that is attached to the automatic transmission of an automatic car, and is used when the shift lever is in the neutral range (N range) or parking range (P range). Air conditioning compressor ON signal, 5
6 is an oil pressure ON signal when the discharge pressure of the pump of the power steering device is above a predetermined value, and 57 is a signal corresponding to the cooling water temperature. 5B is discharge pressure information (detection or discrimination signal) of the continuously variable displacement compressor characterized by the present invention.

In the past, compressor load information output based on discharge pressure was always given to the engine control unit 41 even when driving, and the engine control unit 41 predicted the target rotation speed immediately after inputting the load fluctuation. However, since the idle control valve 36 is operated to adjust the control air amount and the corresponding fuel injection amount at the next idling time, it is possible to keep the engine speed close to the appropriate value at all times.

Incidentally, although the above-mentioned embodiment has been described with respect to a oscillating swash plate type compressor, it is also applicable to a pressure FM machine equipped with a rotating swash plate type or a vane type continuously variable capacity mechanism.

[Effects of the Invention] As described in detail above, the present invention inputs the discharge pressure detection information of the continuously variable displacement compressor into the engine control section together with other Φ image state detection information, and adjusts the idle rotation speed based on the information. Since the compressor load fluctuations that occur during driving are accurately grasped and steadily reflected in the next rotation speed control during idling, concerns such as engine stalling and discomfort can be avoided. It is possible to prevent this from occurring.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an example of a rocking swash plate compressor embodying the present invention, Fig. 2 is an explanatory diagram showing the process of idle control, and Fig. 3 is a trend of correlation between drive torque and capacity of the compressor. FIG. 4 is a diagram showing the correlation between compressor drive torque and discharge pressure. 1...Cylinder block 3b...Discharge to 17.
...Pressure hole]8...Detector 4]...Engine control section

Claims (2)

[Claims] (1) In a vehicle equipped with a continuously variable capacity air conditioning compressor, various vehicle condition detection information and compressor discharge pressure detection information are input to the engine control unit, and the engine control unit operates based on the above information. An idle rotation speed control method comprising controlling an idle rotation speed adjustment means. (2) The idle rotation speed control method according to claim 1, wherein the compressor discharge pressure detection information is discrimination signal information obtained by detecting an average median value of a discharge pressure fluctuation region.