JPH04328094A - Pitch angle detecting device for variable pitch propeller - Google Patents

Abstract

PURPOSE:To accurately detect a pitch angle during operation with no influence by rotational vibration of a propeller. CONSTITUTION:A pair of electromagnetic pickups 23, 24 are arranged opposed to angle position detecting protrusive parts 21a, 22a provided in each periphery of the first rotary angle detecting member 21, rotated on a propeller hub 10, and the second rotary angle detecting member 22, integrally rotated with the propeller hub 10, in accordance with a change of a pitch angle of a propeller blade 11, to provide an arithmetic means for calculating this pitch angle based on a phase difference between output signals of these electromagnetic pickups.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pitch angle detection device capable of detecting the pitch angle of a variable pitch propeller employed in an aircraft or the like during operation.

0002

[Prior Art] Variable pitch propellers used in aircraft, etc. increase operational efficiency by changing their pitch angle to an optimal angle according to operating conditions such as rotational speed, absorbed horsepower, wind speed, and air density. It is configured. Therefore, this type of variable pitch propeller needs to be equipped with a pitch angle detection device that can accurately and directly detect the pitch angle during operation. Based on this need, for example, Japanese Patent Publication No. 64-10670
In the control method for a propeller-type wind turbine generator disclosed in the publication, a beta shaft is provided integrally with a piston of a hydraulic cylinder formed in a propeller hub, and the beta shaft is rotatably supported by the propeller hub at an intermediate portion thereof. The shank of the propeller blade is cam-engaged to change the pitch angle of the propeller blade in accordance with the axial movement of the beta shaft, and a potentiometer provided at the outer end of the beta shaft is configured to cam engage the shank of the propeller blade. Pitch angle is being detected.

[0003] In the pitch angle detection device described above, since the beta shaft rotates as the propeller rotates, the contact member of the potentiometer wears out prematurely due to sliding resistance at the contact portion between the beta shaft and the potentiometer, impairing its durability. It happens. Further, since the potentiometer described above has a mechanical contact portion, an error occurs in its output value due to rotational vibration of the propeller, making it impossible to accurately detect the pitch angle of the propeller blade.

0004

[Object of the invention] In order to solve the above problems, the present invention
It is an object of the present invention to provide a pitch angle detection device that can accurately detect a pitch angle during operation without having a mechanical contact part and being unaffected by rotational vibration of a propeller.

[0005]

SUMMARY OF THE INVENTION The pitch angle detection device of the present invention comprises: a first rotation angle detection member rotatably attached to a propeller hub and rotated in response to changes in the pitch angle of a propeller blade; a second rotation angle detection member that is fixed to the propeller hub adjacent to the propeller hub and rotates integrally with the propeller hub; a pair of electromagnetic pickups that are arranged at the same time and output signals representing each rotation angle of the rotation angle detection member by independently electrically detecting the same concave portion or convex portion; and a phase difference between the output signals of these electromagnetic pickups. The present invention is characterized in that it includes calculation means for calculating the pitch angle of the propeller blade based on the pitch angle of the propeller blade.

[0006]

In the pitch angle detection device having the above structure, when the pitch angle of the propeller blade changes while the propeller is rotating, the first rotation angle detection member rotates in response to the change angle, and the second rotation angle detection member rotates in response to the change angle. A relative phase difference occurs with respect to the rotation angle detection member. This phase difference is detected by the output signal of the electromagnetic pickup, and the changed pitch angle of the propeller blade is calculated by the calculation means based on the detected phase difference. As described above, the pitch angle detection device of the present invention can detect the pitch angle of a propeller blade in real time using the electromagnetic pickup without providing a contact portion with a member that rotates integrally with the propeller during operation of the propeller. This makes it possible to accurately calculate the pitch angle of the propeller blades without being affected by the rotational vibrations of the propeller.

[0007]

[Embodiment] The variable pitch propeller shown in FIG. 1 has propeller blades 11, 11 supported rotatably in the direction of the arrow in the figure at each base end on a propeller hub 10 driven by an engine E of an aircraft. ing. In this variable pitch propeller, a hydraulic cylinder (not shown) provided in the propeller hub 10 operates under the control of a known electric control device, and the operation of the hydraulic cylinder causes the propeller blades 11, 11 to move at each base end. The pitch angles of the propeller blades 11, 11 are changed.

The pitch angle detection device 20 of the present invention includes a first rotation angle detection member 21 rotatably attached to the propeller hub 10 at a position close to each base end of the propeller blades 11, 11; A second rotation angle detection member 22 is provided adjacent to the angle detection member 21 and fixed to the propeller hub 10. Each rotation angle detection member 21, 22 is formed in an annular shape, and has angular position detection protrusions 21a, 22a on its outer periphery.
are provided for each. The first rotation angle detection unit 21 located on the right side of the figure is integrally provided with a bevel gear 12 on its left end surface.
It meshes with a pair of bevel gears 13a and 13b fixed to each base end of the gear. The bevel gear 13a rotates integrally with the upper propeller blade 11 in the direction of the arrow, thereby rotating the bevel gear 12. The bevel gear 13b is rotated in the opposite direction to the upper propeller blade 11 by the rotation of the bevel gear 12. With this gear arrangement, the first rotation angle detection member 21 rotates integrally with the bevel gear 12 in response to changes in the pitch angle of the propeller blades 11, 11. Note that the angular position detection convex portion 21a provided on the outer periphery of the first rotation angle detection member 21 detects the second rotation angle when each pitch angle of the propeller blades 11, 11 is set to a predetermined low pitch angle. It is assembled so as to be located at the same position in the rotational direction as the angular position detection convex portion 22a of the member 22.

Further, the pitch angle detecting device 20 of the present invention includes a pair of electromagnetic pickups 23 disposed on the outer peripheral surfaces of the rotation angle detecting members 21 and 22, facing each other in the radial direction.
, 24, and calculation means for calculating the pitch angle of the propeller blades 11, 11 by executing the calculation program shown in the flowchart of FIG. Electromagnetic pickup 23,2
4 is fixedly supported by a support arm 25 on a part of the main body of the engine E, and independently electrically connects the angular position detection protrusions 21a and 22a of the rotation angle detection members 21 and 22 while the propeller is rotating. The rotation angle detection members 21, 2
A signal representing each rotation angle of 2 is output. In the above embodiment, the rotation angle detection members 21 and 22 are provided with the angular position detection protrusions 21a and 22a, but these protrusions 21 and 2
2a may be replaced with a recess.

Pitch angle detection device 2 configured as described above
When the pitch angle of each propeller blade 11, 11 is changed to an angle β during operation of a variable pitch propeller with 0,
The bevel gear 12 rotates via the bevel gears 13a, 13b by the rotational drive of the base end portions of the propeller blades 11, 11,
The first rotation angle detection member 21 is rotated by an angle β on the propeller hub 10 (see FIG. 2). This creates a relative phase difference between the first rotation angle detection member 21 and the second rotation angle detection member 22. At this time, the calculation means that executes the calculation program of the flowchart shown in FIG.
Time t1 for the second rotation angle detection member 22 to rotate once in response to each output signal of the electromagnetic pickups 23 and 24 at 00
The calculation of the time t2 of the phase difference between the rotation angle detection members 21 and 22 is started, and after the calculation of the times t1 and t2 is completed in steps 101 and 102, respectively, the following equation 1 is calculated in step 103.

[Equation 1] t2/t1=β/360° Next, in step 104, the angle β is calculated, and a signal representing the calculated angle β is given to an appropriate display device (not shown). Angle β is propeller blade 1
It is displayed as each pitch angle of 1 and 11.

In carrying out the present invention, the arithmetic means described above is constituted by a known microcomputer, and the microcomputer is equipped with an electromagnetic pickup 23,
The above calculation may be performed by providing 24 output signals.

[Brief explanation of the drawing]

FIG. 1 is a schematic structural diagram of a variable pitch propeller equipped with a pitch angle detection device of the present invention.

FIG. 2 is a perspective view of the pitch angle detection device shown in FIG. 1;

FIG. 3 is a flowchart representing a program executed by arithmetic means applied to the pitch angle detection device shown in FIG. 1;

[Explanation of symbols]

10... propeller hub, 11... propeller blade, 12,
13a, 13b...Bevel gear, 20...Pitch angle detection device, 2
DESCRIPTION OF SYMBOLS 1, 22... Rotation angle detection member, 21a, 22a... Angular position detection convex part, 23, 24... Electromagnetic pickup.

Claims (1)

[Claims] Claims: 1. A first rotation angle detection member rotatably attached to a propeller hub and rotated in response to changes in pitch angle of a propeller blade; fixed to the propeller hub adjacent to the rotation angle detection member; a second rotation angle detection member that rotates integrally with the propeller hub; and a recess or protrusion arranged opposite to the angular position detection recess or protrusion provided on the outer periphery of each rotation angle detection member. a pair of electromagnetic pickups that electrically detect each independently and output signals representing each rotation angle of the rotation angle detection member; and a pair of electromagnetic pickups that output signals representing each rotation angle of the rotation angle detection member; A pitch angle detection device for a variable pitch propeller, comprising calculation means for calculating the pitch angle of a variable pitch propeller.