JPH05155395A - Changing method and device of seal for shock absorbing device - Google Patents

Abstract

PURPOSE:To allow seals in a shock absorbing device to be easily, safely, and speedily changed by filling with gases collapsible devices other than those which have a seal to be changed to expand the devices to expose the seals which must be changed, and removing and changing the exposed seals. CONSTITUTION:A shock absorbing device composed of a cylinder 3b and a piston 3c whose one side is joined to a main body and other side is joined to a wheel 2, other than those which have a seal to be changed are filled by a distributing device 6 with gases to cause the cylinder 3b and the piston 3c to be relatively moved to expand the devices themselves. Thus, seals in those collapsible devices 3 which have a rolling seal to be changed are exposed. The exposed seals are then removed and the collapsible devices 3 which had a seal to be changed are isolated from a wheel 2. A new seal is then inserted from the bottom of the collapsible device 3 which has been isolated from the wheel 2 before being attached to a specified location.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for replacing a seal of a heavy-duty moving body, particularly, an impact absorbing device of an airplane.

[0002]

2. Description of the Related Art Generally, in an airplane, a shock absorbing device called a shock strut is provided between a wheel and a body or a wing in order to reduce a shock received when landing and moving by a wheel. The shock strut has an elongated columnar shape having a cylinder and a piston therein and is extendable, and contains gas and oil to absorb the shock by its cooperative operation. Therefore, the shock struts have an O to seal the oil.
-A ring-type seal is provided. This seal will need to be replaced if an oil leak occurs.

A conventional method for replacing the shock strut seal will be briefly described with reference to FIG.
FIG. 4 is a view illustrating a work of replacing a shock strut seal according to the related art. In FIG. 4, a shock strut 3 is connected between the wing portion 1 a of the airplane and the body 1 and the wheel 2. As will be described later, the seal of the shock strut 3 is provided between the cylinder and the piston of the shock strut 3, and thus is exposed to the outside by extending the shock strut. Also, since the seal is an O-ring type, it is necessary to replace the wheel 2 for replacement.
After separating the shock strut 3 and the shock strut 3 from each other, a seal must be inserted through the gap. Therefore,
As shown in FIG. 4, a plurality of large jacks 40 are installed below the fuselage 1 and the wing portion 1a of the airplane, and the entire airplane is lifted by the large jacks 40 to expose the seal in the shock strut 3.

[0004]

However, according to such a conventional method, it takes a long time to install the large jack 40, and lifting the airplane by the large jack 40 while keeping it horizontal requires a high level of skill. If a reliable support location for the jack is not selected, the jack may come off, resulting in excessive time and labor and a problem in safety. Also, not all domestic airfields have equipment such as large jacks, and it has been desired that seals can be easily replaced anywhere as needed. An object of the present invention is to provide a method and a device that can replace seals easily, safely and quickly.

[0005]

In order to achieve the above object, a method of replacing a seal for a shock absorbing device according to the present invention is such that a main body is connected to a wheel via a plurality of shock absorbing devices. Is composed of a cylinder and a piston, one of the cylinder and the piston is connected to the main body, and the other is connected to the wheel, and the fluid is injected between the cylinder and the piston. A method for replacing an O-ring type seal incorporated in a shock absorbing device adapted to reduce a shock force transmitted from a wheel to the main body, the shock absorbing device other than a shock absorbing device having a seal to be replaced. The device is filled with gas to cause relative movement between the cylinder and the piston to extend the shock absorber, thereby exposing the seal of the shock absorber having the seal to be replaced. A step of removing the exposed seal, separating the shock absorber having the seal to be replaced from the wheel, and inserting the seal from below the shock absorber separated from the wheel. Steps and attaching the inserted seal in place.

In order to achieve the above-mentioned object, the apparatus used in the method for replacing the seal of the present invention is provided with a pressurizing means for sending gas under pressure, and between the pressurizing means and a plurality of the impact absorbing devices. And a pressure gauge means for detecting the pressure of the gas pressure-fed to each impact absorbing device, and a distribution means for transmitting the gas pressure-fed from the pressurizing means to the impact absorbing device. It has valve means for stopping the pumping of gas to the shock absorbers and drain means for releasing the gas filled in each shock absorber.

[0007]

According to the method and apparatus for exchanging the seal for the shock absorbing device of the present invention, the shock absorbing device of an airplane is used instead of the large jack to lift the body, so that the installation of the large jack is unnecessary and the large size You can safely and securely replace the seal without worrying about choosing the location of the jack.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In the description of this embodiment, the term gas means air or an inert gas (for example, N ₂ gas). FIG. 1 is a perspective view of the periphery of one leg of a model of an airplane.
Only two of the four wheels are shown. The wheels 2 attached to the axles 4 are connected to each other by a track beam 5 in the front-rear direction. The shock strut 3 extending vertically has an upper portion, not shown, attached to the body. Further, the lower portion of the shock strut 3 is attached to the rod 5a by the track beam 5 and the pin 5b at the pin portion 3a.

Next, the structure of the shock strut 3 will be briefly described. FIG. 2 is a view showing a state in which the shock strut 3 is lifted up and cut off from the track beam 5, and a part of the shock strut is a sectional view. In FIG. 2, the shock strut 3
Is composed of a cylinder portion 3b and a piston portion 3c. In a normal use state, the piston portion 3c is inserted into the cylinder portion 3b, and gas and oil are injected into a space 3d defined by them. .. The gas in the space 3d acts as a spring, and the oil in the space 3d acts as a damper, so that the co-operation of the two cushions the shock received by the wheels during landing, etc., and does not transmit them directly to the airframe. ing. The Oreo seal 3e is an O-ring type seal,
The inner circumference of the cylinder portion 3b and the outer circumference of the piston portion 3c are sealed to prevent oil in the space 3d from leaking to the outside. The gas port 3f is attached to the top of the cylinder part 3b, and the gas can freely flow in and out of the cylinder part 3b through the gas port 3f. The structure of the shock strut is well known and will not be described in detail below.

Further, a device for filling the shock strut 3 with gas will be described. FIG. 3 shows a distributor for filling the shock struts 3 with gas.
In some aircraft models, five legs are provided, one of which is a shock strut seal replacement, so there are four legs that can be used for the purposes described below during replacement. Therefore, the distributor 6 shown in FIG.
Has one gas inlet 6g and four gas outlets 6h. In reality, the four gas outlets should be connected to the four shock struts respectively, but in FIG. 4, one gas outlet is provided for the sake of simplifying the description and because the configurations are all common. Only 6h are shown connected to the shock struts 3.

The gas inlet 6g of the distributor 6 is connected to a pressurizing means (not shown), that is, a compressor. The gas inlet 6g is connected to the gas outlet 6h via a main valve 6e and a sub valve 6c. The gas outlet 6h is
It is connected to the gas port 3 f of the shock strut 3 via the hose 7.

A branch is provided from the gas inlet 6g to the main valve 6e, and a main drain valve 6f is provided at the tip of the branch. The main valve 6e is openable and closable, and when in the open position, gas from the compressor can pass to the sub valve 6c side, and when in the closed position, gas from the compressor is blocked from passing to the sub valve 6c side. It is like this. A main pressure gauge 6d is provided between the main valve 6e and the sub valve 6c, and the pressure of the gas supplied from the compressor is measured by the main pressure gauge 6d.

A branch is provided from the sub valve 6c to the gas outlet 6h, and a sub drain valve 6b is provided at the tip of the branch. The sub-valve 6c can be opened and closed, and when it is in the open position, the gas passing through the main valve 6e can pass to the gas outlet 6h side, and when it is in the closed position, the gas passing through the main valve 6e goes to the gas outlet 6h side. It is designed to prevent the passage of each. When the sub-valve 6c is in the closed position and the sub-drain valve 6b is in the open position, the gas in the shock strut 3 is individually released to the atmosphere via the gas outlet 6h. A sub pressure gauge 6a is provided between the sub valve 6c and the gas outlet 6h, and the pressure of the gas in the shock strut 3 is individually measured by the sub pressure gauge 6a.

The shock strut 3 originally has a function of cushioning the shock by the gas filled therein, but the gas pushes the piston portion 3c by pumping the gas at a pressure higher than that normally used. As a result, the shock strut itself can be made longer than the normal length.

Further, the procedure for replacing the seal of the shock strut 3 will be described below with reference to FIGS. 2 and 3. First, referring to FIG. 3, the distributor 6 is connected via a hose 7 to a shock strut 3 other than the shock strut whose seal is to be replaced. As mentioned above, in FIG. 3 the dispensing device 6 is shown connected to only one shock strut for simplicity of illustration. It is assumed that gas is pumped in the direction of arrow A from a compressor (not shown). Each sub valve 6c
Is in the open position but the main valve 6e is in the closed position.

By the way, in some aircraft models,
There is one leg in front of the fuselage, two legs in parallel behind the fuselage, and one leg on each of the left and right wings, for a total of five legs. There is. In this case, for example, when replacing the shock strut seal of the leg of the wing, it is necessary to extend only the two legs provided at the rear of the body, and the leg in front of the body needs to be extended. There is no. The reason for this is that if the shock struts on the two legs provided at the rear of the fuselage are extended, the aircraft lifts the rear part of the aircraft in a posture in which it bows forward, which causes the wings of the wing to be replaced to be replaced. This is because the shock struts on the legs also extend, exposing the seal. Therefore, in such a case, it suffices to connect the hose 7 to the two shock struts. In this case, in order to ensure the stability of the airframe, the leg portion of the wing portion on the side opposite to the leg portion to be replaced should not be extended. On the other hand, when the target of the replacement work is any of the legs behind the fuselage, it is necessary to extend the left and right wing legs and the remaining legs behind the fuselage in total of three. Therefore, in such a case, the hose 7 is connected to the three shock struts.

When the main valve 6e is opened from such a state, the gas fed under pressure from the compressor is evenly transmitted to the two or three shock struts 3. The transmitted gas is the piston portion 3c of the shock strut 3.
Press and extend two or three shock struts 3 simultaneously. As the shock strut 3 extends, the aircraft body rises. When the main valve 6e is closed at the time when the machine body has risen to a predetermined position, the pressure feeding of gas is stopped and the machine body is also prevented from rising. If the extension of the shock strut 3 is different due to the weight distribution of the aircraft and the aircraft is not horizontal in the left-right direction, the sub drain valve 6
By setting b to the open position, the gas inside the shock struts 3 is released to the atmosphere, and the shock struts are individually contracted so that the fuselage becomes horizontal. In addition, strong wind (about 1
As long as it does not blow more than 5 knots), the aircraft will be held stable by appropriately extending two or three shock struts as described above, but an auxiliary jack can be used if necessary. In that case, it is not necessary to extend all the shock struts, and only the shock struts at the positions opposing the auxiliary jacks need to be extended.

FIG. 2 shows the state of the shock struts whose seals should be replaced when the shock struts are extended and the fuselage is raised. Cylinder part 3
Although b and the piston portion 3c move relative to each other in a separating direction, they are not completely separated from each other, and the two seals 3e are exposed. From this state, the rod 5a is cut off from the piston portion 3c by the track beam 5 and the pin 5b, and lifted by means such as a rope. In this state, the used seal may be cut with a cutter or the like, or may be pulled out from below the piston portion 3c. After removing the used seal, a new seal is inserted from below the piston portion 3c so as to pass through the piston portion 3c and moved to a predetermined position. After that, the piston portion 3c is lowered, and the track beam 5 and the rod 5
a is connected by a pin 3a and a pin 3b.

Referring again to FIG. 3, when the main drain valve 6f of the distributor 6 is opened in the state where the above work is completed, all the gas in the shock strut 3 connected to the hose 7 is released to the atmosphere and the airframe is opened. Descends. While monitoring the sub pressure gauge 6a, the main drain valve 6f is closed when the gas in the shock strut 3 reaches an appropriate pressure. Fine adjustment of the pressure in each shock strut 3 may be performed by opening and closing the sub valve 6c and the sub drain valve 6b. When the fine adjustment is completed, the gas port 3f is closed, the distributor 6 is cut off from the shock strut 3, and the seal replacement work is completed.

Although the embodiments of the invention of the present application have been described with reference to the drawings, the invention of the present application should not be construed as being limited to the above-described embodiments, but various modifications and improvements can be appropriately made. For example, the gas outlet of the distribution device 6 is not limited to four and may be any number. Further, in view of the fact that the stability of the airframe holding decreases as the wind becomes stronger, an anemometer is provided in the distribution device 6 so that an alarm is generated when the wind speed becomes 15 knots or more, or the alarm is generated by an electromagnetic valve. It is also possible to stop the pressure feeding of gas from the compressor at the same time as the alarm by linking with.

[0021]

According to the method and apparatus for replacing the seal for the shock absorbing device of the present invention described in detail above, since the shock absorbing device of an airplane is used instead of the large jack to lift the airframe, the large jack is used. Is unnecessary,
In addition, the seal can be replaced safely and securely without having to worry about selecting the installation location of the large jack.

[Brief description of drawings]

FIG. 1 is a perspective view around one leg of a model of an airplane.

FIG. 2 is a view showing a state in which a shock strut 3 is lifted up and a track beam 5 is cut off.

FIG. 3 shows a dispensing device for filling the shock struts 3 with gas.

FIG. 4 is a diagram illustrating a work of replacing a seal of a shock strut according to the related art.

[Explanation of symbols]

 2 wheels 3 shock struts 6 distributor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Norikatsu Endo 2-3-32 Fushiodai, Ikeda-shi, Osaka (72) Inventor Tatsuo Yanagisawa 5-2-3-303 Sakurano-cho, Toyonaka-shi, Osaka (72) Invention Shinji Ikegami 5-6 Tennodai, Abiko-shi, Chiba Cosmo Tennodai 605 (72) Inventor Yasuyuki Omagari 553-1 Shinano-cho, Totsuka-ku, Yokohama-shi, Kanagawa Park Hills K507 (72) Koji Kihara Midori-gaoka, Naka-ku, Yokohama-shi, Kanagawa 89 All Nippon Airways Midorigaoka company housing A-406 (72) Inventor Sugahara Ju 1-13-12-1109 Higashioi, Shinagawa-ku, Tokyo (72) Inventor Kenzo Shimizu 4-15 Shimizucho, Chitose-shi, Hokkaido Tsutsumi Condominium 502

Claims (6)

[Claims] 1. A main body is connected to a wheel through a plurality of shock absorbing devices, the shock absorbing device comprises a cylinder and a piston, one of the cylinder and the piston being connected to the main body, and the other. Is connected to the wheel and is incorporated in an impact absorbing device adapted to absorb the impact force transmitted from the wheel to the main body by using a fluid injected between the cylinder and the piston. In the method of replacing the O-ring type seal, the shock absorbing device other than the shock absorbing device having the seal to be replaced is filled with gas to cause the relative movement of the cylinder and the piston, and Elongating, thereby exposing the shock absorber seal having the seal to be replaced, removing the exposed seal, and the impact of having the seal to be replaced. A shock absorber seal comprising the steps of separating the shock absorber from the wheel, inserting a seal from below the shock absorber separated from the wheel, and mounting the inserted seal in place. Replacement method. 2. The method for exchanging a seal for a shock absorbing device according to claim 1, further comprising the step of evacuating the gas filled in the shock absorbing device other than the shock absorbing device having the replaced seal. 3. The method for replacing a seal for a shock absorbing device according to claim 1, wherein the gas is air. 4. The method for replacing a seal for a shock absorbing device according to claim 1, wherein the gas is an inert gas. 5. The device used in the method for replacing a seal according to claim 1, wherein a pressurizing means for sending gas under pressure is provided between the pressurizing means and a plurality of the impact absorbing devices. The distribution means for transmitting the gas pressure-fed from the means to the impact absorbing device, the distribution means comprising sub-gauge means for detecting the pressure of the gas pressure-fed to each impact absorbing device and gas for each impact absorbing device. A device used for a method of replacing a seal for a shock absorber, the sub-valve for stopping the pressure feeding of the shock absorber, and the sub-drain valve for releasing the gas filled in each shock absorber. 6. The distributing means further comprises a main gauge for detecting the pressure of the gas sent by the pressurizing means, and a main valve for stopping the sending of gas from the pressurizing means to the distributing means. Item 4. A device used in the method for replacing a seal for a shock absorber according to item 4.