CN103231799B - Integral joint used for connecting tail undercarriage - Google Patents

Abstract

The invention belongs to the design technology of helicopters, and relates to an integral joint used for tail landing gear connection. One side of the overall joint is the fitting surface with the fuselage, the shape of the fitting surface is the same as the shape of the fuselage skin, and the other side is the connecting surface, which is provided with the tail landing gear rocker joint, the buffer strut joint and the There is a "triangular" transition area between the tail landing gear rocker joint and the connecting piece. Four lugs are arranged side by side on the tail landing gear rocker joint. On both sides of the rocker arm joint of the tail landing gear, a shoulder bush is embedded in each lug, and joint bearings are installed on the lugs on the buffer strut joint, and there is a "Y" between the rocker arm joint of the tail landing gear and the buffer strut joint Shaped ribs. The present invention is located outside the fuselage, respectively connects the tail landing gear and the fuselage, does not need to open a large opening on the fuselage skin, and reduces the stress concentration of the fuselage skin.

Description

An integral joint for tail landing gear connection

technical field

The invention belongs to the design technology of helicopters, and relates to an integral joint used for tail landing gear connection.

Background technique

At present, the landing gear installation method widely used by helicopters with three-point landing gear in the world is that the rocker arm and buffer strut of the landing gear pass through the skin of the fuselage, and are respectively installed on two frames in the fuselage. Reinforcement connection. This installation method requires a relatively large opening at the bottom of the fuselage, which makes the force transmission here complicated and cannot be used for a monocoque structure. The more famous ones are: Apache, Black Hawk.

Contents of the invention

The object of the present invention is to propose an integral joint suitable for the connection of the tail landing gear of the monocoque structure. The technical solution of the present invention is that one side of the integral joint 13 is a bonding surface with the fuselage, and the profile of the bonding surface is the same as the shape of the fuselage skin, and the other side is a connecting surface, and the connecting surface is provided with a tail gear rocker. There is a "triangular" transition area 3 between the arm joint 1, the buffer strut joint 2 and the connecting piece 4 between them, and there is a "triangular" transition area 3 between the tail landing gear rocker joint 1 and the connecting piece 4, and four One lug 7, four lugs 7 are placed on both sides of the tail landing gear rocker joint 1 in a group of two, each lug 7 is embedded with a shoulder bushing 5, and on the buffer strut joint 2 The joint bearing 6 is installed on the lug 8, and there is a "Y" shaped reinforcing rib 9 between the rocker joint 1 of the tail landing gear and the buffer strut joint 2, and one end of the stiffening rib 9 is connected with the lug 8 on the buffer strut joint 2 , the other two ends of the reinforcing rib 9 are respectively connected with the lugs 7 on both sides of the rocker arm joint 1 of the tail landing gear. The present invention has advantages and beneficial effects, and the integral joint has the following advantages:

1. The integral joint fully considers the various loads of the tail landing gear in various harsh environments, including tension, compression, bending and torsion caused by high-speed landing (5.5m/s), special deflection of the tail wheel, etc. , shear and other loads;

2. The integral joint integrates the rocker joint of the tail landing gear, the buffer strut joint and the connecting structure in the middle, omitting various connecting parts and fasteners in the middle, simplifying the force transmission route and reducing the concentrated stress points , to reduce the weight and improve the security of the connection;

3. The integral joint is connected to the outside of the fuselage, and the concentrated load of the tail landing gear can be converted into a dispersed load and transmitted to the fuselage without opening holes in the skin, thus solving the problem that the monolithic structure cannot transmit large concentrated loads. load problem.

This kind of joint is located outside the fuselage and connects the tail landing gear and the fuselage respectively. It does not need to open a large opening on the fuselage skin to reduce the stress concentration of the fuselage skin. This joint can convert the concentrated load of the tail landing gear into a dispersed load and transfer it to the fuselage skin, and can be widely used in various types of fuselage structures, especially the monocoque structure that cannot bear concentrated loads.

Description of drawings

Figure 1 is a schematic diagram of the overall joint structure of the tail landing gear.

Fig. 2 is a bottom view of Fig. 1 .

Fig. 3 is a schematic diagram of the installation position of the present invention on a helicopter.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings.

One side of the integral joint 13 is a fitting surface with the fuselage, the shape of the fitting surface is the same as that of the fuselage skin, and the other side is a connecting surface, on which a tail landing gear rocker arm joint 1 and a buffer strut joint 2 are arranged. And the connecting piece 4 between them, there is a "triangular" transition area 3 between the tail landing gear rocker joint 1 and the connecting piece 4, and four lugs 7 are arranged side by side on the tail landing gear rocker joint 1, and the four ears Each piece 7 is placed on both sides of the rocker arm joint 1 of the tail landing gear in groups of two, and a shoulder bush 5 is embedded in each ear piece 7, and a joint bearing 6 is installed on the ear piece 8 on the buffer strut joint 2 , There is a "Y" shaped rib 9 between the tail landing gear rocker joint 1 and the buffer strut joint 2, one end of the stiffener 9 connects with the lug 8 on the buffer strut joint 2, and the other two ends of the stiffener 9 They are respectively connected with the lugs 7 on both sides of the rocker arm joint 1 of the tail landing gear.

This invention adopts the integral machine-added joint 13 to transfer the concentrated load on the tail landing gear 14, 15 to the fuselage structure. The integral joint 13 integrates the rocker joint 1 of the tail landing gear, the buffer strut joint 2 and the connecting piece 4 in the middle, omitting various connecting pieces and fasteners in the middle, simplifying the force transmission route and reducing the concentration. Stress points, reduced weight and increased connection security. The bonding surface profile of the integral joint 13 and the fuselage is the same as the shape of the fuselage skin, which can ensure the bonding with the fuselage. There is a "triangular" transition area 3 between the tail landing gear rocker joint 1 and the connecting piece 4, which can be used as a transition area for tension and compression loads to prevent stress concentration, increase the contact area with the fuselage, and reduce the The shear stress acting on the joint joint under the special deflection condition of the tail wheel. Four lugs 7 are arranged side by side on the tail landing gear rocker joint 1, and every two of the four lugs 7 are placed on both sides of the tail landing gear rocker joint 1, and are connected with the two sides of the tail landing gear rocker respectively. Each ear piece 7 of the rocker arm joint 1 is embedded with a shoulder bushing 5 to prevent the wear of the joint of the tail landing gear when rotating, and a joint bearing 6 is installed on the ear piece 8 on the buffer strut joint 2 to eliminate lifting. The bending moment of the falling frame acting on the joint, reducing the stress level. There is a "Y" shaped rib 9 between the rocker arm joint 1 of the tail landing gear and the buffer strut joint 2, one end of the rib 9 is connected with the lug 8 on the buffer strut joint 2, and the other two ends are respectively connected with the tail landing gear. The lugs 7 on both sides of the rocker arm joint 1 are connected to improve the stability of the joint, and at the same time reduce the eccentric moment of the rocker arm joint 1 lug 7 and the buffer strut joint 2 lug 8 acting on the joint, reducing the stress level . The integral joint 13 can not only transfer loads in the X and Z directions, but also convert the bending moment and torque acting on the tail landing gear 14 and 15 into loads that the fuselage can bear and transmit to the fuselage. Therefore, the concentrated load is converted into a dispersed load and transmitted to the fuselage structure, which solves the problem that the monocoque structure cannot transmit the concentrated load.

Example

The aircraft adopts an integral machine-added joint 13 with a length of 0.86 meters to transmit the concentrated load on the tail landing gear 14, 15 to the fuselage structure adopting a monocoque structure. The integral joint 13 processes the tail landing gear rocker joint 1, the buffer strut joint 2 and the connecting pieces therebetween. The tail landing gear rocker joint 1 is connected to the tail beam transition section 11 through 12 bolts, and the buffer strut joint 2 Connected to the duct 12 through 4 bolts, the middle "triangular" transition 3 evenly transfers the load to the bolts of the tail beam and the duct joint frame 16, reducing the stress level of the bolts connecting the duct 12 and the transition section 11 of the tail beam, The connection part is connected to the duct 12 by a blind rivet. Each lug 7 of the rocker arm joint 1 is embedded with a shoulder bush 5 to prevent the wear of the tail landing gear from rotating butt joint lugs 7, and a joint bearing 6 is installed on the lug 8 of the buffer strut joint 2 to eliminate the effect of the landing gear on Bending moment on the joint, reducing the stress level. There is a "Y" shaped rib 9 between the rocker arm joint 1 of the tail landing gear and the buffer strut joint 2, one end of the rib 9 is connected with the lug 8 on the buffer strut joint 2, and the other two ends are respectively connected with the tail landing gear. The lugs 7 on both sides of the rocker arm joint 1 are connected to improve the stability of the joint, and at the same time reduce the eccentric moment of the rocker arm joint 1 lug 7 and the buffer strut joint 2 lug 8 acting on the joint, reducing the stress level .

Claims (1)

1. An integral joint for tail landing gear connection, characterized in that one side of the integral joint (13) is a fitting surface with the fuselage, the profile of the fitting surface is the same as the shape of the fuselage skin, and the other side is The connecting surface is provided with the tail landing gear rocker joint (1), the buffer strut joint (2) and the connecting piece (4) between them, the tail landing gear rocking arm joint (1) and the connecting piece (4) There is a "triangular" transition area (3) between them, four lugs (7) are arranged side by side on the rocker arm joint (1) of the tail landing gear, and each of the four lugs (7) is placed in a group of two On both sides of the landing gear rocker joint (1), a shoulder bushing (5) is embedded in each lug (7), and a joint bearing (6) is installed on the lug (8) on the buffer strut joint (2) , there is a "Y" shaped rib (9) between the tail landing gear rocker joint (1) and the buffer strut joint (2), and one end of the stiffener (9) is connected to the lug on the buffer strut joint (2) ( 8) Connecting, the other two ends of the ribs (9) are respectively connected to the lugs (7) on both sides of the tail landing gear rocker joint (1).