JP2750425B2 - Damper structure for helicopter rotor blades - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damper structure in a lead / lag direction for a rotor blade of an industrial unmanned helicopter or the like. Related to

[0002]

2. Description of the Related Art A conventional damper structure for a rotor blade of a helicopter will be described with reference to FIG. A spindle shaft 3 is radially led out from a rotating head 2 fitted and fixed to a rotor rotating shaft 1, and one end of a hub grip 4 is fitted and attached to the spindle shaft 3,
Two arms 4a and 4b from the other end are opposed to each other almost in parallel to a plane perpendicular to the rotor rotation axis 1 and are radiated about the rotor rotation axis 1 in the direction of the hub grip center line La. It is protruded. Those arms 4a, 4
The base portion 5a of the rotor blade 5 is sandwiched between the rotor blades 5b, and the rotor blade 5 with respect to the hub grip 4 within a certain angle range (for example, 45 °, 90 ° or 180 ° or less)
It is rotatably mounted by bolts 6.

[0003] The rotor blade center line Lb is set so that the rotor blade center line La can be varied in an angle range of ± θ in the lead direction (forward direction) and the lug direction (retreat direction) with respect to the hub grip center line La. 5 is made. This damper structure buffers the movement of the left and right rotates that shift in the lead / lag direction due to the sudden rotation or stoppage of the rotor and fluctuations in the lift generated while the rotor blade 5 rotates, and the like. This is necessary to suppress the imbalance of the displacement.

Next, a conventional damper structure will be specifically described. A damper arm 7 is fixed to a base 5a of the rotor blade 5 with a screw 8, and a bolt 6 is inserted together with the base 5a. A damper holder 10 holding a ring-shaped damper rubber 9 is fixed to the outer periphery of the base of the hub grip 4 with screws 11. At one end of the damper shaft 12,
A U-shaped clamp 13 is fitted, and attached so that it can move forward and backward. The clamp 13 is moved and adjusted forward or backward along the damper shaft 12 by rotating the adjusting screw 14 right and left.

The damper pin 15 inserted through the locking hole at the tip of the clamp 13 and inserted into the center hole of the damper rubber 9
Is inserted, and a retaining pin 16 (not shown) is attached to the end. The other end of the damper shaft 12 is connected to a stud 17 projecting from a plate surface at the tip of the damper arm 7, and a retaining pin (not shown) 18 is attached to the stud 17 or the tip of the damper shaft 12. When the adjusting screw 14 is rotated left and right, the clamp 13 advances and retreats from the damper shaft 12, and the rotor blade 5 is angle-adjusted in the lead direction and the lug direction via the damper arm 7. It can be aligned with the direction of the grip center line La.

[0006] The angular displacement (play) of the rotor blade 5 in the lead-lag direction caused by sudden rotation or stoppage of the rotor and fluctuations in lift generated while the rotor blade 5 is rotating are buffered by the damper rubber 9. And the range of play (± θ) is limited. When the helicopter is stored in the accommodation room during non-operation, for example, it is necessary to bend the left and right rotor blades 5 at predetermined angles in the lead and lug directions around the bolts 6 in order to save space. is there. In this case, the retaining pin 16 is removed, and the damper pin 15 is pulled out of the damper rubber 9. The removed parts are temporarily attached to the clamp 13 again so as not to be lost.

[0007]

As shown in FIG. 3, a conventional damper structure has a damper arm 7, a screw 8,
Stud 17, retaining pin 18, damper shaft 1
2, adjustment screw 14, clamp 13, damper pin 15,
Retaining pin 16, damper rubber 9, damper holder 1
The adjustment screw 14 is finely adjusted in order to adjust the direction of the rotor blade center line Lb toward the hub grip center line La in order to adjust the direction of the rotor blade center line Lb toward the hub grip center line La. Therefore, there is a disadvantage that the man-hour for adjusting the damper structure when using a helicopter is increased.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a damper structure which eliminates these conventional drawbacks, has a small number of parts, is easy to assemble, and does not require angle adjustment when setting the rotor blade in the center line direction of the hub grip. To provide.

[0009]

[Means for Solving the Problems]

(1) According to the first aspect of the present invention, through holes are formed on the hub grip center line (passing through the center of the hole for inserting the bolt) at the protruding end of each arm of the hub grip so as to face each other. A ring-shaped damper is fitted and fixed in each through hole. On the rotor blade center line at the base of the rotor blade (passing through the center of the hole for inserting the bolt),
A damper pin insertion hole is formed to face the center hole of the damper. A common damper pin is inserted into the center hole of the damper of each arm and the damper pin insertion hole of the base.

(2) According to the second aspect of the present invention, a recess is formed on the center line of the rotor blade (passing through the center of the hole for inserting the bolt) on the upper surface or the bottom surface near the base of the rotor blade, and a ring is formed in the recess. Shaped damper is fitted and fixed. On the outer surface of one of the arms of the hub grip,
One end of a damper plate made of spring material is attached,
The other end is extended so as to face the concave portion of the rotor blade. On the inner surface of the damper plate extension end,
A damper pin is mounted on the hub grip center line passing through the center hole of the bolt so as to face the center hole of the damper. The damper pin is removably fitted into the center hole of the damper.

(3) In the third aspect of the present invention, in the damper structure for the rotor blade of the helicopter according to the above (2), the damper pin has a small diameter portion inserted into a center hole of the damper, and the small diameter portion. Larger diameter,
A large-diameter portion that is not inserted into the center hole. (4) In the invention of claim 4, in the damper structure for the rotor blade of the helicopter according to the above (2) or (3), a protrusion is formed at one end of the damper pin, and the protrusion is formed on the damper plate. It is inserted into the caulking hole, and the top of the protrusion is caulked to the damper plate.

(5) In the invention of claim 5, in the damper structure for the rotor blade of the helicopter according to any one of the above (1) to (4), the damper is made of rubber.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention is shown in FIGS. 1 and 2 by assigning the same reference numerals to parts corresponding to those in FIG. 3, and redundant description will be omitted. In the embodiment shown in FIG.
a, 4b, the center line of the hub grip (the bolt insertion hole 4)
d) passing through the center of (d), the through holes 4c are formed facing each other, and each of the through holes has a ring-shaped damper rubber 9.
Are fitted and fixed. Rotor blade center line of base 5a of rotor blade 5 (passing through center of bolt insertion hole 5b) L
b, the damper pin insertion hole 5c is inserted into the center hole 9 of the damper.
a. A common damper pin 15 is inserted into the center hole 9a of the damper of the arms 4a and 4b and the damper pin insertion hole 5c of the base 5a. Damper pin 1
The retaining pin 16 is inserted into the small hole at the tip of the fifth.

In this structure, the rotor blade center line Lb
The positions of the center hole 9a of the damper rubber and the damper pin insertion hole 5c of the base 5a are set so that the direction of the center line La coincides with the direction of the hub grip center line La. Therefore, the damper pin 15 is inserted into those holes. By itself, the rotor blade 5 is positioned in a desired direction with respect to the hub grip 4. Therefore, there is no need for direction adjustment.

The variation ± θ of the rotation of the rotor blade 5 in the lead / lag direction about the bolt 6 is determined by the damper rubber 9.
And its elasticity. When storing the helicopter in the accommodation room during non-operation, the rotor blade 5
Can be easily bent at a predetermined angle in the lead / lag direction with the bolt 6 as a center, by removing the retaining pin 11 and pulling out the damper pin 15. However, these removed damper pins 15
The retaining pin 11 must be inserted into the center hole 9a of the damper rubber so as not to be lost and temporarily fixed or separately stored.

The embodiment shown in FIG. 2 eliminates the need to use nerves for storing the removed damper parts. In the embodiment of FIG. 2, a concave portion 5d is formed on the rotor blade center line (passing through the center of the bolt insertion hole 5b) Lb on the upper surface near the base 5a of the rotor blade, and a ring-shaped damper rubber 9 is provided in the concave portion 5d. Fitted and fixed. On the other hand, one end of a damper plate 31 made of a spring material is attached to the upper surface of the arm 4a of the hub grip 4 with two screws 33, and the other end is extended so as to face the recess 5d (damper rubber 9) of the rotor blade. Is done. The damper pin 15 is planted on the inner surface of the extended end of the damper plate 31 on the center line of the hub grip passing through the center of the bolt 6 so as to face the center hole 9a of the damper rubber. The damper pin 15 is fitted in the center hole 9a of the damper rubber so as to be freely inserted and removed.

In the example of FIG. 2, the damper pin 15 has a small diameter portion 15a inserted into the center hole 9a of the damper rubber, and a large diameter portion 15b having a diameter larger than the small diameter portion 15a and not inserted into the center hole 9a. The length of the large-diameter portion 15b in the axial direction holds the distance between the damper plate 31 and the upper surface of the rotor blade 5 at that length. A protrusion 15c is formed at one end of the damper pin 15, and the protrusion 15c is inserted into a caulking hole at the extended end of the damper plate 31, and the top of the protrusion is crushed and caulked to the damper plate 31. The large diameter portion 15b is effective for caulking the damper pin 15 and fixing it to the damper plate 31.

When the helicopter is stored in the accommodation room during non-operation, when the rotor blade 5 is bent at a predetermined angle in the lead-lag direction around the bolt 6, the damper plate 31 is made of a spring material. When the force is applied, the damper pin 15 is easily pulled out from the damper rubber 9 and the rotor blade 5 may be bent in a predetermined direction. During operation, the rotor blade 5 may be returned to the original position, and the damper pin 15 may be inserted into the damper rubber 9. Since the damper pin 15 is always fixed to the damper plate 31 even during non-operation, there is no need to temporarily attach the helicopter when storing the helicopter or to separately store the helicopter.

In the description so far with reference to FIG. 2, the damper structure including the damper rubber 9 and the damper plate 31 to which the damper pins 15 are attached is provided on the upper surfaces of the rotor blade 5 and the hub grip 4. Is not limited to this, and may be provided on each bottom surface side. Although other damper materials can be used instead of the damper rubber 9,
Rubber is relatively durable and can be obtained at low cost.

[0020]

According to the damper structure of the present invention, two damper rubbers 9, a damper pin 15 and a retaining pin 16 are provided in the example of FIG.
In the example of FIG. 2, the damper rubber 9 and the damper plate 31 in which the damper pins 15 are planted, and two mounting screws 33 are provided. In any case, the damper structure can greatly reduce the number of parts as compared with the conventional structure shown in FIG. 3, and the assembling becomes simpler.

In the damper structure of the present invention, in the example of FIG. 1, the center hole 9a of the damper rubber of the hub grip 4 and the center of the rotor blade base 5a are aligned so that the directions of the hub grip center line La and the rotor blade center line Lb coincide. The position with the damper pin insertion hole 5c is set. Similarly, in the example of FIG. 2, the positions of the damper pin 15 fixed to the damper plate 31 attached to the hub grip 4 and the center hole 9a of the damper rubber of the rotor blade 5 are set. Therefore, in any case, the rotor blade 5 is positioned in the predetermined direction with respect to the hub grip 4 simply by inserting the damper pin 15 into the predetermined hole. Therefore, a conventional angle adjusting portion is not required.

When the damper pin 15 is always fixed to the damper plate 31 as shown in FIG. 2, when the helicopter is stored in the accommodation room, the rotor blade 5 is bent in a predetermined lead / lug direction so as not to take up space. In this case, the damper pin 15 is pulled out from the damper rubber 9, but is always fixed to the damper plate 31, so that there is no need to temporarily attach the damper pin 15 or to store it separately, and there is no risk of loss.

[Brief description of the drawings]

FIG. 1 is a view showing an embodiment of the present invention, A is a perspective view, and B is a sectional view.

FIG. 2 is a view showing another embodiment of the present invention, wherein A is a perspective view and B is a sectional view.

FIG. 3 is a plan view of a conventional damper structure.

Claims (5)

(57) [Claims] An end of a hub grip is fitted and attached to a spindle shaft of a rotor head of a helicopter,
Two arms from the other end protrude in a radial direction (center line direction of the hub grip) around the rotation axis, facing each other, substantially parallel to a plane perpendicular to the rotor rotation axis. The base of the rotor blade is sandwiched between them and attached by bolts to limit the variation of rotation of the rotor blade in the lead / lag direction with respect to the hub grip within a predetermined range, and to restrict the rotation of the rotor blade within that range. In a damper structure for a rotor blade of a helicopter, which provides damping, on a hub grip center line (passing through the center of the hole into which the bolt is inserted) of a protruding end of each arm of the hub grip,
Through holes are formed facing each other, and a ring-shaped damper is fitted and fixed to each of the through holes, and the rotor blade center line at the base of the rotor blade (passes through the center of the hole into which the bolt is inserted). Wherein a damper pin insertion hole is formed to face the center hole of the damper, and a common damper pin is inserted into the center hole of the damper of each arm and the damper pin insertion hole of the base. Damper structure for helicopter rotor blades. 2. An end of a hub grip is fitted and attached to a spindle shaft of a rotor head of a helicopter,
Two arms from the other end protrude in a radial direction (center line direction of the hub grip) around the rotation axis, facing each other, substantially parallel to a plane perpendicular to the rotor rotation axis. The base of the rotor blade is interposed and bolted to limit the play of the rotor blade in the lead-lag direction with respect to the hub grip within a predetermined range and dampen the rotation of the rotor blade within the predetermined range. In the damper structure for the rotor blade of the helicopter, a concave portion is formed on the rotor blade center line (passing through the center of the hole for inserting the bolt) on the upper surface or the bottom surface near the rotor blade base, and the concave portion has a ring shape. And a damper made of a spring material is provided on the outer surface of one of the arms of the hub grip. One end of the damper plate is attached, and the other end is extended so as to face the concave portion of the rotor blade. A damper pin is provided on the inner surface of the extended end of the damper plate on the center line of the hub grip passing through the center of the bolt. A damper structure for a rotor blade of a helicopter, wherein the damper pin is mounted to face the center hole, and the damper pin is removably fitted into the center hole of the damper. 3. The damper structure for a rotor blade of a helicopter according to claim 2, wherein the damper pin has a small diameter portion inserted into a center hole of the damper, and a diameter larger than the small diameter portion, and is inserted into the center hole. And a large diameter portion that is not formed. 4. A damper structure for a rotor blade of a helicopter according to claim 2, wherein a protrusion is formed at one end of said damper pin, and said protrusion is inserted into a caulking hole of said damper plate. The top of the part is crimped to the damper plate. 5. A damper structure for a helicopter rotor blade according to claim 1, wherein said damper is made of rubber.