阅读说明：本技术 一种无人直升机复合材料桨叶及桨尖配重方法 (Unmanned helicopter composite material blade and blade tip weight balancing method ) 是由 焦志文 邵松 姜年朝 张勇 王超 于 2019-09-29 设计创作，主要内容包括：本发明公开了一种无人直升机复合材料桨叶及桨尖配重方法。桨尖抛物线修型配重设计包括桨尖配重铅块、带抛物线面前缘配重管、前缘配重螺钉、后缘配重管及后缘配重螺钉,所述的桨尖配重铅块在制作桨叶时放置在桨尖前缘位置；所述的带抛物线面前缘配重管铸在桨尖配重铅块里,其抛物线面与桨叶抛物线修型桨尖外形一致；所述的后缘配重管在制作桨叶时放置在桨尖后缘位置。本发明还设计一种无人直升机复合材料桨叶抛物线修型桨尖配重配平方法。所述的抛物线修型桨尖配重设计结构美观,配平方法操作简单,在不影响桨叶气动效率的情况下依然能够有效调节桨叶的动静平衡,同时安全可靠可反复操作。(The invention discloses a composite material blade of an unmanned helicopter and a blade tip weight balancing method. The design of the tip parabola modification counterweight comprises a tip counterweight lead block, a front edge counterweight pipe with a parabola surface, a front edge counterweight screw, a rear edge counterweight pipe and a rear edge counterweight screw, wherein the tip counterweight lead block is placed at the front edge of the tip when the blade is manufactured; the front edge counterweight pipe with the parabolic surface is cast in a blade tip counterweight lead block, and the parabolic surface of the front edge counterweight pipe is consistent with the parabolic modified blade tip of the blade in shape; the rear edge counterweight pipe is placed at the rear edge position of the blade tip when the blade is manufactured. The invention also designs a method for balancing the balance weight of the parabola modification type blade tip of the composite material blade of the unmanned helicopter. The parabola repair type blade tip counterweight has an attractive design structure, the operation of the balancing method is simple, the dynamic and static balance of the blade can be effectively adjusted under the condition that the pneumatic efficiency of the blade is not influenced, and the parabola repair type blade tip counterweight is safe, reliable and capable of being operated repeatedly.)

1. The utility model provides an unmanned helicopter combined material paddle which characterized in that: the blade comprises a blade body, a parabolic modification part is arranged at the front end part of the blade body, a rear edge counterweight pipe, a front edge counterweight pipe and a blade tip counterweight lead block are arranged in the parabolic modification part, and a front edge counterweight pipe screw and a rear edge counterweight pipe screw are respectively arranged on the front edge counterweight pipe and the rear edge counterweight pipe to seal the pipe orifice.

2. The unmanned helicopter composite blade of claim 1, wherein: lead particles are arranged in the front edge counterweight pipe and the rear edge counterweight pipe.

3. The unmanned helicopter composite blade of claim 1, wherein: the front edge counterweight pipe and the blade tip counterweight lead block are of an integrated structure, and the end part of the front edge counterweight pipe is flush with the edge of the blade body.

4. A tip weighting method for an unmanned helicopter composite blade according to claim 1 further comprising the steps of: the method comprises the following steps:

step (1): measuring static distances in the span direction of two blades to be paired into a pair, and respectively recording the static distances as

Step (2): calculating the weight of lead particles to be added into the small blade counterweight pipe according to the difference value of the static distances in the spanwise directions of the two blades

and (3): the weight is added into a blade tip counterweight pipe with smaller static distance

and (4): measuring the chordwise static distances of the two blades relative to the trailing edge, respectively

And (5): under the condition of not influencing the static distance in the span direction, the weight of the lead particles to be added in the front edge counterweight pipe and the rear edge counterweight pipe of the two blades is calculated according to the difference value of the static distances in the chord direction

Technical Field

The invention relates to a blade counterweight design, in particular to a parabola modification type blade tip counterweight design for a composite material blade of an unmanned helicopter, and belongs to the field of aircraft structure design technology and composite material forming process.

Background

With the development of the helicopter rotor technology, in order to exert the aerodynamic potential of the rotor, the utility of an advanced engine is fully utilized, the flight performance of the helicopter is improved, and higher requirements are provided for the appearance design of the blade. In recent years, researchers at home and abroad carry out a great deal of research work on the aspect, and the research scholars have considerable development and improvement, and a plurality of new technologies appear and are applied in practice.

In order to meet the requirements of the quality characteristics and the balance of the blades, a balance weight is usually required to be arranged at the tip of each blade to eliminate or reduce the unbalance phenomenon among the blades caused by manufacturing errors. The blade tip counterweight and the connection form thereof are determined according to the structural form of the blade girder, and the blade tip counterweight is safe and reliable and is convenient to assemble, disassemble and adjust. At present, the blades are made of composite materials mostly, and the composite material blades have the characteristic of moldability, so that the limitation of the technological factors on the appearance is greatly reduced, the appearance of the blades can be designed to be more in line with the requirement of the aerodynamic performance of the rotor, in other words, the appearance can be very complex, so that a plurality of difficulties exist in the counterweight process, and how to quickly and effectively counterweight the blades becomes the problem to be solved urgently.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: aiming at the requirements of complex appearance design and adjustable span-wise gravity center and chord-wise gravity center of the advanced composite material blade, the composite material blade of the unmanned helicopter is designed, the device is attractive in design structure, the span-wise gravity center of the blade can be still effectively adjusted under the condition of not influencing the aerodynamic efficiency of the blade, and meanwhile, the device is safe, reliable and capable of being operated repeatedly.

The technical scheme of the invention is realized by the following modes: the blade comprises a blade body, wherein a parabolic modification part is arranged at the front end part of the blade body, a rear edge counterweight pipe, a front edge counterweight pipe and a blade tip counterweight lead block are arranged in the parabolic modification part, and a front edge counterweight pipe screw and a rear edge counterweight pipe screw are respectively arranged on the front edge counterweight pipe and the rear edge counterweight pipe to seal pipe openings.

Lead particles are arranged in the front edge counterweight pipe and the rear edge counterweight pipe.

The front edge counterweight pipe and the blade tip counterweight lead block are of an integrated structure, and the end part of the front edge counterweight pipe is flush with the edge of the blade body.

A method for balancing the tip of a composite blade of an unmanned helicopter comprises the following steps:

step (1): measuring static distances in the span direction of two blades to be paired into a pair, and respectively recording the static distances as

，

；

Step (2): calculating the weight of lead particles to be added into the small blade counterweight pipe according to the difference value of the static distances in the spanwise directions of the two blades

The calculation formula is as follows:

whereinLThe distance from the tip of the oar to the rotation center;

and (3): the weight is added into a blade tip counterweight pipe with smaller static distance

The lead shot is screwed well;

and (4): measuring chordwise statics of two blades relative to the trailing edgeDistances, respectively, are denoted as

，

；

And (5): under the condition of not influencing the static distance in the span direction, the weight of the lead particles to be added in the front edge counterweight pipe and the rear edge counterweight pipe of the two blades is calculated according to the difference value of the static distances in the chord direction

The calculation formula is as follows:

whereinThe distance from the center line of the front edge counterweight pipe to the rear edge;

the distance from the center line of the rear edge counterweight pipe to the rear edge is calculated, and then the weight is added into the front edge counterweight pipe of the blade with small chord-wise static distance

While adding a weight of lead shot into the rear edge balance tube of the other blade

The lead shot of (1).

The invention has the beneficial effects that: the parabola modification type tip counterweight of the composite material blade of the unmanned helicopter has the advantages of attractive design structure, simple operation of the balancing method, capability of effectively adjusting the dynamic and static balance of the blade under the condition of not influencing the aerodynamic efficiency of the blade, safety, reliability and repeated operation.

Drawings

FIG. 1 is a schematic perspective view of the finished article of the present invention;

wherein: 1-blade body, 2-rear edge counterweight pipe screw, 3-rear edge counterweight pipe, 4-front edge counterweight pipe screw, 5-parabola shaping part, 6-front edge counterweight pipe and 7-blade tip counterweight lead block.

Detailed Description

The invention is described in further detail below:

the invention provides a composite material blade of an unmanned helicopter, which is structurally shown in figure 1 and comprises a blade body 1, wherein a blade tip part of the blade body 1 is provided with a modification part, the modification part is a parabolic modification part 5, the modification part is arranged to enable the blade to better meet the requirement of the aerodynamic performance of a rotor wing, a plurality of balance weights are arranged at the blade tip part of the blade body 1, and the balance weights are used for correspondingly adjusting the center of gravity of the blade in the span-wise direction so as to eliminate or reduce the unbalance phenomenon among blades caused by manufacturing errors. In the invention, the balance weight mainly comprises a blade tip balance weight lead block 7, the blade tip balance weight lead block 7 is arranged at the front side of the parabola correction part 5, and the blade is balanced in advance by utilizing the balance weight lead block so as to eliminate errors to the maximum extent.

Since the mass of the tip counterweight lead block 7 is set according to a theoretical value, corresponding errors inevitably exist in practical use, and therefore fine adjustment means needs to be added. According to the invention, the balance weight pipe is further arranged and is divided into a front edge balance weight pipe 6 and a rear edge balance weight pipe 3, the front edge balance weight pipe 6 is arranged on the parabolic modification part 5 of the blade body 1, more specifically, the front edge balance weight pipe 6 is connected with a blade tip balance weight lead block 7, the rear edge balance weight pipe 3 is arranged at the rear edge of the blade tip of the blade body 1, lead particles can be added into the front edge balance weight pipe 6 and the rear edge balance weight pipe 3 to correct the balance weight, and front edge balance weight screws 4 and rear edge balance weight screws 2 are respectively arranged at the end parts of the front edge balance weight pipe 6 and the rear edge balance weight pipe 3 to plug the inner space of the front edge balance weight pipe 6 and the rear edge balance weight pipe 3, so that the balance weight lead particles are prevented from being thrown.

More specifically, the leading edge counterweight pipe 6 is cast in a tip counterweight lead block 7, and the parabolic surface of the leading edge counterweight pipe is consistent with the shape of the parabolic modification 5.

The invention also provides a method for balancing the balance weight of the parabola-shaped trimming blade tip of the composite material blade of the unmanned helicopter, which comprises the following steps:

step (1): the static span (relative to the center of rotation) of two blades to be paired is measured and recorded as

，

；

Step (2): calculating the weight of lead particles to be added into the small blade counterweight pipe according to the difference value of the static distances in the spanwise directions of the two blades

The calculation formula is as follows:

whereinLThe distance from the tip of the oar to the rotation center;

and (3): the weight is added into a blade tip counterweight pipe with smaller static distance

The lead shot is screwed well;

and (4): the chord static distances (relative to the trailing edge) of two blades are measured and recorded respectively

，；

And (5): under the condition of not influencing the static distance in the span direction, the weight of the lead particles to be added in the front edge counterweight pipe and the rear edge counterweight pipe of the two blades is calculated according to the difference value of the static distances in the chord direction

The calculation formula is as follows:

wherein

The distance from the center line of the front edge counterweight pipe to the rear edge;

the distance from the center line of the rear edge counterweight pipe to the rear edge is obtained. That is, the weight is added into the leading edge counterweight pipe of the blade with small chord static distance

While adding a weight of lead shot into the rear edge balance tube of the other blade

The lead shot of (1).

Therefore, the parabola repair type tip counterweight of the composite material blade of the unmanned helicopter, which is disclosed by the technical scheme, is attractive in design structure, simple in operation of the balancing method, safe, reliable and repeatedly operable, and still can effectively adjust the dynamic and static balance of the blade under the condition of not influencing the pneumatic efficiency of the blade.

In addition to the above embodiments, the present invention may have other embodiments. All technical solutions formed by adopting equivalent substitutions or equivalent transformations fall within the protection scope of the claims of the present invention.