JPH03204393A - Pitch control device for variable pitch propeller - Google Patents

Abstract

PURPOSE:To minimize fuel consumption by obtaining the optimum engine rpm at which the product of the engine efficiency and the propeller efficiency is maximized from the relationship between the propeller efficiency and the engine rpm and the relationship between the engine efficiency and the engine rpm and controlling the propeller pitch so that the calculated rpm is reached. CONSTITUTION:Based on the results detected with sensors 31-35, the relationship between the propeller efficiency etap and the engine rpm Ne at the current throttle opening thetat is obtained. From a preset engine performance data, the relationship between the engine efficiency etae and the engine rpm Ne at the current throttle opening thetat is obtained. From these relationships, an optimum engine rpm Nbest is obtained at which the product of the propeller efficiency etap and the engine efficiency etae is maximized. The pitch of the blade 15 is controlled so that the optimum engine rpm Nbest is reached. This maximizes the thrust produced with the propeller relative to the amount of fuel supplied to the engine.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pinch control device for a variable pitch propeller used, for example, in an aircraft equipped with a variable pitch propeller.

[Conventional technology]

Japanese Unexamined Patent Publication No. 60-76499 proposes a method and device for controlling the propeller pitch and propeller rotation speed so that the operating efficiency of the propeller (propeller efficiency) is maximized according to the operating conditions of the aircraft. ing.

(Problems to be Solved by the Invention) By the way, in the conventional method and device described above, the propeller rotation speed is controlled so that the operating efficiency of the propeller is maximized. engine efficiency (
Since no consideration is given to the engine output relative to the amount of fuel, the propulsion force of the propeller is not always maximized relative to the amount of fuel. In other words, fuel efficiency is not the best.

The present invention has been made focusing on the above-mentioned problems,
The object of the present invention is to provide a pitch control device for a variable pitch/7 pitch propeller that controls the propeller pitch (1) (2) in consideration of engine efficiency and achieves the best fuel efficiency.

[Means to solve the problem]

In order to achieve the above object, the present invention provides the pitch control device with an operational state detection means for detecting airspeed, atmospheric pressure, atmospheric temperature, engine rotation speed, throttle opening, etc. means for determining the relationship between propeller efficiency and engine speed at the current throttle opening based on the detection results of the means; and determining the relationship between engine efficiency and engine speed at the current throttle opening from preset engine performance data. means for determining an optimum engine rotation speed at which the product of the propeller efficiency and the engine efficiency is a maximum value from the relationship between the propeller efficiency and the engine rotation speed and the relationship between the engine efficiency and the engine rotation speed; and the optimum engine rotation speed. The configuration includes means for controlling the propeller pitch so that

[Effect]

In the pinch control device for a variable pitch propeller according to the present invention, the relationship between the propeller efficiency and the engine speed at the current throttle opening is determined based on the detection result of the operating state detection means, and the relationship between the propeller efficiency and the engine rotation speed is determined based on preset engine performance data. The relationship between engine efficiency and engine speed at the current throttle opening is determined, and from these relationships, the optimal engine speed at which the product of propeller efficiency and engine efficiency becomes the maximum value is determined, and this optimal engine speed is determined. The propeller pitch is controlled as follows.

〔Effect of the invention〕

In the present invention, the propeller pitch is controlled so that the product of propeller efficiency and engine efficiency becomes the optimum engine speed, which is the maximum value, so the propulsive force generated by the propeller relative to the amount of fuel given to the engine is It can maximize fuel efficiency.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

(3) (4) FIG. 1 schematically shows a pinch control device for a variable pitch propeller according to the present invention applied to a small aircraft, and the device includes a variable pinch mechanism 10, a hydraulic control circuit 20, and an electronic control device. It is composed of a device 30.

As shown in FIG. 2, the variable pitch mechanism 10 includes a hydraulic cylinder 11 equipped with a screw 1-la and a return spring llb that are movable only in the axial direction, and a piston lla of this hydraulic cylinder 11 integrally. A hub 13 has a pin 12 that moves in the axial direction and a cam hole 13a into which the pin 12 fits, and is rotatably but immovably assembled in a housing 14 that is rotated by an engine (not shown). A gear 13b integrally formed at one end of the hub 13, and a gear 13b that is rotatably and axially connected to the housing 14.
- Consists of a gear 152 etc. that is integrally formed at one end of the blade 15 that is assembled immovably and meshes with the gear 13b, and the piston is activated by hydraulic oil applied to the hydraulic cylinder 11 from the hydraulic control circuit 20. When lla moves to the right in the figure, the blade 15 rotates in the direction of the arrow in the figure, and the pinch (propeller pitch) of the blade 15 is changed to a high pitch.

As shown in FIG. 1, the hydraulic control circuit 20 includes an oil pump 21 driven by an engine, a regulator valve 22 that keeps the hydraulic pressure discharged from the oil pump 21 constant, and a hydraulic pressure that is supplied to the hydraulic cylinder 11. It is comprised of an electromagnetic flow control valve 23, a throttle 24, etc., which control the flow rate of hydraulic oil. The electromagnetic flow control valve 23 is a spring center type 3-port electromagnetic valve, and the electronic control device 3
The amount of hydraulic fluid supplied and discharged from the hydraulic cylinder 11- can be controlled according to the current applied value to each solenoid l'a, b- by 0, and when each solenoid l'a, b is de-energized, the state is neutral as shown. The boat 23b is held in position and the port 232 connected to the hydraulic cylinder 11 is connected to the oil pump 21, and the boat 1-23c is connected to the oil sump 25.
It is configured to be blocked from In addition, the aperture 24
is to always release a part (a small amount) of the hydraulic oil supplied to the hydraulic cylinder 11 to the oil sump (5) (6) 25, and when the electromagnetic flow control valve 23 is in a non-controlled state (for example, the electronic control device 30 .In the event of a failure such as short circuit or disconnection of solenoids a and b), the hydraulic cylinder 11
Release the hydraulic oil inside and lower the pitch of the blade 15 (
This is a generally known fail-safe feature for single-engine airplanes.

The electronic control unit 30 includes a momentum sensor 31. which detects the airspeed V of the airplane. Atmospheric pressure P during operation.

Atmospheric pressure sensor 32. Atmospheric temperature sensor 33 that detects the atmospheric temperature TO during operation. An engine rotation speed sensor 34 that detects the rotation speed Ne of the engine that drives the propeller of the airplane. It is composed of a throttle opening sensor 35 that detects the throttle opening θt that determines the load on the engine, a microcomputer 36, and the like, and each sensor 31 to 35 is connected to the microcomputer 36, respectively.

The microcomputer 36 has an interface, C
It is equipped with a PU, ROM, RAM, etc., and stores the program corresponding to flowchart 1 in Figure (7) 3, as well as the arithmetic expressions (generally known arithmetic expressions) necessary to execute the program. Various maps (e.g.
Engine horsepower Ps map based on engine speed Ne and throttle opening θt shown in the figure, progress rate J shown in FIG.
and the propeller efficiency ηp map based on the power coefficient Cp, the sixth
This is an engine efficiency ηe map based on the engine speed Ne and throttle opening θt shown in the figure, each of which has been determined in advance through experiments, etc.), and the detection obtained by each sensor 31 to 35 is stored. Based on the signal, energization of each solenoid a, b-. of the electromagnetic flow control valve 23 is controlled.

Next, the operation of this embodiment configured as described above will be explained along the flowchart t in FIG. Upon starting the engine, the microcomputer 36 starts executing the program at step 100 in FIG.
After executing the initial setting process necessary for the electronic circuit in step 1, the circulation process consisting of steps 102 to 117 is repeatedly executed.

(8) In this circulation process, in step 102, the airspeed ■, atmospheric pressure Po, atmospheric temperature To, and engine speed Ne are
and slot]・The small opening degree θt is the momentum sensor 31. Atmospheric pressure sensor 32. Atmospheric temperature sensor +33 Engine speed sensor 34
and the atmospheric pressure Po and atmospheric temperature T read from the throttle opening sensor 35 and read in step 103.
The air density ρ is calculated based on O, and in step 104, the relationship between engine horsepower PS and engine speed Ne is derived from the engine horsepower Ps map in FIG. 4 based on the throttle opening degree (9t) read above.

Next, in step 105, the following recalculation formula (■) is performed.

Based on ■ and the air density ρ above, the relationship between engine horsepower Ps and engine speed Ne is the power coefficient Cp and engine speed N.
It is converted into the relationship e.

Arithmetic formula ■ P s = p ・Cp-N p' ・D
A' calculation formula ■ Np=-Ne (K is a constant) where N
p is the propeller rotation speed D is the propeller diameter.In step 106, the following calculation formula ■ and the above calculation formula ■
The relationship between the progress rate J and the engine rotation speed Ne is derived from .

Arithmetic formula ■ J = V/Np -D Next, in step 107, the relationship between the power coefficient Cp and the engine speed Ne and the progress rate J and the engine speed N are determined.
The relationship between the power coefficient Cp and the advancement rate J is derived from the relationship of e, and in step 108, the propeller efficiency ηp and the advancement rate J are derived from the relationship between the power coefficient Cp and the advancement rate J and the propeller efficiency ηp map shown in FIG. In step 109, the relationship between the propeller efficiency ηp and the engine rotational speed Ne is derived from the relationship between the propeller efficiency ηp and the advancement rate J and the relationship between the advancement rate J and the engine rotational speed Ne. In addition,
The propeller efficiency ηp is expressed by the following formula ■,
Further, the propulsive force T generated by the propeller is expressed by the following formula (2).

Formula ■ 771)=V-T/Ps=J-Ct/Cp formula■
T-ρ・Ct-Np-D However, Ct is the thrust coefficient, and the engine efficiency ηC is calculated from the engine efficiency ηC map in FIG. The relationship between the engine speed Ne is derived and the engine efficiency η is determined by the steering knob I11.
Relationship between (] and engine speed Ne and propeller efficiency ηp
From the relationship between and engine speed Ne, the overall efficiency η (ηe
×ηp) and the engine rotational speed Ne is derived, and in step 112, the optimum engine rotational speed Nbest at which the overall efficiency ηt becomes the maximum value is determined.

After that, Step 7B 11:l Trowel again engine speed N
e is read, and at step 114, the optimum engine speed Nbest and the engine speed read above are read.
〉The fan rotation speed Ne is compared with the engine rotation speed Ne.
If it is determined that is large, the process advances to step 115,
If it is determined that the difference is smaller, the process proceeds to step 116, and if it is determined that they are equal, the process proceeds to step 117-
Proceed with \.

Now, the engine speed Ne is the optimal engine speed N b
e: 1”N e in step 114.
>N bestJ, step 115
When the current applied to the solenoid flow control valve 32 is increased, υ=, solenoid a1-b.
The current flow of ＼ is cut off. As a result, hydraulic oil is supplied to the hydraulic cylinder 11, and the valve I7.-f" I5 is rotated in the direction of the arrow in FIG. 2, increasing its Bi-f.
．． The resistance at the pusher increases and the rotation of the turner and the turner becomes low -1 (return to step 113 after processing Suge II5).

On the other hand, if the engine speed Ne is smaller than the optimum engine speed Φy motor number Nbesj, then f'' at step 11,1
N e < N 1ees t J + positive 't11 constant group (in step 6, step 1, step 116, electromagnetic flow control valve 3
At the same time, the current application value of the curve 72 1"b-" is increased. Due to the dirt, hydraulic oil is discharged from the hydraulic cylinder 11, and the play I'l5 is rotated in the direction 1ii) opposite to the arrow in FIG. 2, and its pitch is reduced.
The resistance at the IV blade is reduced, and the rotation of the blade 11 and the engine is increased by 1.
,.

Also, the engine speed Ne is the optimum engine speed Nbe
st, then rNe−N be in step 114
Based on the determination that stj, a set value of current is applied to the solenoid l'a of the electromagnetic flow control valve 32 in step 117, and the current of the solenoid l'a of the electromagnetic flow control valve 32 is applied to the solenoid l'a. - The application of current to node b - is cut off, and a flow rate of hydraulic oil corresponding to the flow rate discharged through the throttle 24 is supplied to the hydraulic cylinder 1 through the electromagnetic flow control valve 32.
1. As a result, the amount of hydraulic oil in the hydraulic cylinder 11 does not change, the blade 5 is held without rotating, and the "ζ pinch" is maintained. Note that in step 117
After processing, the process returns to step 102.

As can be understood from the above operation description, in the first embodiment, the relationship between the propeller efficiency ηp and the engine rotation speed Ne at the current throttle opening et is required (
(see steno knobs 102 to 109), and the relationship between the engine efficiency ηe and the engine rotational speed Ne at the current throttle opening Ot is determined from 4 preset engine performance data (engine efficiency ηe map in FIG. 6) (step 110). ), and from these relationships, the efficiency η of the property ζ
The optimal engine speed Nbesf at which the product (overall efficiency) ηt of p and engine efficiency ηe is the maximum value is determined (see steps +11, 11..2), and this determined optimal engine speed Nbest is determined. ] ) to blur -1 ~
15 pitches are controlled (ste, zo 1, 13-],
17).

In this way, in the above example, ζ is equal to
Since the pinch of the blade 15 is controlled so that the product (overall efficiency) ηt of p and the engine efficiency ηC becomes the optimum engine rotation speed Nbesj, the amount of fuel given to the engine is The generated propulsive force 'r can be maximized, resulting in improved fuel efficiency.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an example of a control device according to the present invention, FIG. 2 is a cross-sectional view of essential parts showing an example of a variable pinch mechanism, and FIG. 3 is a first microphone 1-j. 1-1 Figure 4 of the program executed by the computer is based on the engine speed and throttle opening stored in Figure 1. Figure 5 is a map of propeller efficiency based on the advance rate and power coefficient stored in the microcomputer in Figure 1. Figure 6 is a map of propeller efficiency based on engine horsepower.
FIG. 3 is a diagram showing a map of engine efficiency based on engine speed and throttle opening stored in the microcomputer shown in the figure. Explanation of symbols 10... Variable pitch mechanism, 20... Hydraulic control circuit,
30... Electronic control device, 31-35... Sensor, 3
6... Microcomputer, ■... Airspeed, P
o...Atmospheric pressure, To...Atmospheric temperature, Ne...Engine speed, θt...Throttle opening, ηp...Propeller efficiency, ηC...Engine efficiency, ηt...Total efficiency , Nbest...optimum engine speed.

Claims (1)

[Claims] Operation status detection means for detecting airspeed, atmospheric pressure, atmospheric temperature, engine speed, throttle opening, etc., and propeller efficiency and engine rotation speed at the current throttle opening based on the detection results of this operation status detection means. means for determining the relationship between engine efficiency and engine speed at the current throttle opening from preset engine performance data; and means for determining the relationship between propeller efficiency and engine speed and the relationship between engine efficiency and engine speed A variable pitch propeller comprising: means for determining the optimum engine speed at which the product of the propeller efficiency and the engine efficiency is maximized from the relationship; and means for controlling the propeller pitch so as to obtain the optimum engine speed. Pitch control device.