JPH06167384A - Vibration measuring equipment for blade - Google Patents

Abstract

PURPOSE:To obtain an equipment for measuring vibration of a blade in a short time with high workability and no error without requiring control of solar beam by providing a vibration accelerometer in the blade and connecting the vibration accelerometer through a rotary shaft with a measuring equipment disposed in the machine body by means of a cable. CONSTITUTION:A vibration accelerometer 3 is fixed to a structural member, e.g. a spur 9, at the tip in a blade 1. The accelerometer 3 detects vertical shift of the locus of the blade 1 electrically as the acceleration of vertical vibration. Vibration detected by the vibration accelerometer 3 for each blade 1 is transmitted through a cable 4 or a spring 5 to a measuring equipment 7 where vertical movement is calculated and displayed through an I/O unit. Furthermore, regulating amount of a tab 8 is calculated and displayed, as required, and the tab 8 of the blade 1 is regulated on the ground thus balancing all blades. When regulating amount of the tab 8 is displayed directly, indexing work of regulating amount of the tab by a worker can be saved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blade vibration measuring device for adjusting a rotor blade of a helicopter.

[0002]

2. Description of the Prior Art Vibration prevention is important for helicopters,
For that purpose, as an example, there is a work for adjusting the deviation of the vertical trajectory of the rotor blade. As this deviation adjustment work, as shown in FIG.
Measurement plate 2 that makes it easier to see the movement (trajectory) during rotation
0 is attached, the strobe 21 is irradiated to the measuring plate 20 from the inside of the airplane, the displacement of the measuring plate 20 is confirmed, and the angle of the adjustment tab of each blade 1 is changed on the ground, The loci of the plurality of blades 1 are adjusted so that they substantially match.

In this case, the measuring plate 20 is a small L-shaped metal plate, and the metal plate attached to the bolt for each blade 1 has a surface of the helicopter 19 visible from the fuselage as shown in FIG. , Different patterns are drawn.
Then, when the measuring member 22 inside the machine body irradiates the strobe 21 synchronized with the rotation of the rotor, the patterns of the measuring plate 20 of each blade 1 are overlapped, and the overlapping states 22 and 23 are viewed and recorded. Here, 22 indicates a normal pattern and 23 indicates a defective pattern.

[0004]

However, in the adjustment of the displacement of the measuring plate 20 described above, the mounting work of the measuring plate 20 is first required, and the pattern reading work starting from the strobe irradiation is performed. It takes a long time to read the data, is easily affected by the sunlight (the amount of light is adjusted), and there is a problem that a reading error occurs due to the deviation of the individual difference of the measurer, and moreover, under certain flight conditions (horizontal cruise etc.) It takes a long time because the measurements are performed together.

An object of the present invention is to provide a novel blade vibration measuring device which is excellent in workability, does not take much time, and is free from sunlight adjustment and error, except for the above-mentioned drawbacks caused by the displacement adjustment by the measuring plate. To do.

[0006]

According to the present invention, which achieves the above-mentioned object, a vibration accelerometer is provided inside a blade, and the vibration accelerometer is connected to a measuring device inside a machine body by a cable via a connecting means of a rotary shaft. The measuring device is characterized in that it is connected and the vibration acceleration is processed and monitored.

[0007]

By embedding the vibration accelerometer inside the blade, the conventional work of attaching the measuring plate for each measurement is unnecessary. The deviation of the vertical loci of the plurality of blades determined by the conventional method is electrically measured as vertical vibration acceleration. For this reason, stroboscopic irradiation from the inside of the machine is unnecessary, and any reading error of the measuring plate due to individual differences among measuring personnel is eliminated. In addition, it is easy to be influenced by sunlight (adjustment of light), and the time-consuming strobe irradiation to pattern reading work is not required, and the measurement or recording can be performed electrically, so that the time is extremely short. The measurement is carried out according to a certain flight condition (horizontal cruising, etc.), but according to the present invention, even if a long time is not taken for that purpose, the flight condition is very short during the other tests and operations. Therefore, the work that has taken a very long time in the past can be greatly simplified.

[0008]

Embodiments of the present invention will now be described with reference to FIGS.

First Embodiment In FIG. 1, a vibration accelerometer 3 is attached to a structural member such as a spar 9 at the tip of the blade 1 inside the blade 1. The vibration accelerometer 3 electrically detects a deviation of the locus of the blade 1 in the vertical direction as vertical vibration acceleration.

The vibration accelerometer 3 is connected to a cable 4,
A slip ring 5 of a rotating rotary shaft 6 is connected to a measuring device 7 inside the machine body by a cable.

As shown in FIG. 2, the measuring device 7 has an input / output device 10, a movement calculator 11, an adjustment amount calculator 12, and a display device 13. In the movement calculator 11, each blade is provided. The vertical vibration amount is calculated and calculated on the display device 1
The deviation from the reference horizontal position in 3 is, for example, ± 10 mm
Is displayed. The adjustment amount calculator 12 calculates and obtains the adjustment amount of the tab 8 to be adjusted based on the shift amount, and the display device 13 displays the adjustment amount of the tab 8 for each blade.

In this way, the vibration from the vibration accelerometer 3 of each blade 1 is transmitted to the measuring device 7 via the cable 4 and the slip ring 5, and the vertical movement is calculated and displayed via the input / output device 10. In addition, the adjustment amount of the tab 8 is calculated and displayed as needed, and on the ground, the tab 8 of the blade 1 is adjusted to balance all the blades.
In this case, by directly displaying the adjustment amount of the tab 8 as shown in FIG. 2, it is possible to omit the work for the operator to calculate the adjustment amount of the tab 8.

FIG. 3 shows a modification of the mounting of the vibration accelerometer 3. Instead of embedding the vibration accelerometer 3 in the inside 2, a connector 14 which is attached to the cap 14 at the tip of the blade 1 and detachable from the cable 4 is attached. It is also possible to conclude with the convenience of maintenance.

[0013]

Second Embodiment Vibration accelerometer 3 attached to blade 1
Are attached not only to the tip of the blade 1 but also from the root to the tip of the blade 1. The signals of the plurality of vibration accelerometers 3 are integrated in the measuring device 7 to grasp the movement of the blade 1 in more detail than in the case of one vibration accelerometer 3, and to adjust the tab 8 adjustment amount more accurately. To

[0014]

Third Embodiment A dedicated measuring device is used in a normal blade adjusting operation. In the first and second embodiments of the present invention, the dedicated measuring device 7 can be prepared and implemented as in the conventional case. In this case, since the vibration accelerometer 3 is always mounted inside the blade 2, the measuring device 7 is connected to the cable 4 from them. In the third embodiment, this measuring device 7
The function corresponding to the above is incorporated into the instrument panel 16 and is always provided. This allows frequent flight tests for blade adjustment without the need for special measuring equipment. Then, if the data of the vibration accelerometer 3 is recorded in a memory or the like in the measuring device 7, the pilot is not burdened. Further, by constantly monitoring the state of the blade 1, it can be applied as a device for detecting an abnormality. The front instrument panel 17 and the central instrument panel 18 are examples of places where the blade vibration is displayed.

[0015]

As described above, according to the present invention, the adjustment work of the rotor blades can be reduced and the total time can be shortened. That is, the work of mounting the measurement plate is eliminated by embedding the vibration accelerometer inside the blade, and the work of reading the pattern of the measurement plate from strobe irradiation during flight is eliminated, and in some cases, only the movement of the blade is measured. Instead, the instrument computer calculates the final blade tab adjustments to further reduce time. Further, according to the present invention, the accuracy of the deviation adjustment is improved. Exclusion 1 and measurement accuracy are improved by replacing the influence of sunlight and individual differences in reading with electrical signal processing of the vibration accelerometer. This eliminates erroneous blade adjustments and greatly reduces the repetition of flight test measurement to adjustment.

[Brief description of drawings]

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

FIG. 2 is a block diagram.

FIG. 3 is a configuration diagram of a modified mounting example.

FIG. 4 is a configuration diagram of a second embodiment.

FIG. 5 is an explanatory diagram of the third embodiment.

FIG. 6 is an explanatory diagram of conventional displacement adjustment.

FIG. 7 is an explanatory diagram of a measurement blade.

[Explanation of symbols]

 1 blade 2 blade inside 3 vibration accelerometer 4 cable 5 slip ring 6 rotary shaft 7 measuring device 8 adjustment tab 9 spar 10 input / output device 11 movement calculation 12 adjustment amount calculation 13 display device 14 cap 15 connector 16 instrument panel 17, 18 Blade vibration display 19 Helicopter 20 Measuring plate 21 Strobe 22 Measurer

Claims (1)

[Claims] 1. A vibration accelerometer is provided inside the blade, and the vibration accelerometer is connected to a measuring device inside the machine body by a cable through a connecting means of a rotary shaft, and the measuring device processes and monitors the vibration acceleration. Vibration measurement device for blades.