CN100478251C - Two-stage series connection two-chamber buffer - Google Patents

Abstract

The utility model relates to a double-cavity buffer in series with two stages, which belongs to the buffer of aircraft landing gear. The buffer consists of a low-pressure buffer piston rod (2), a low-pressure buffer outer cylinder, a high-pressure buffer piston rod (12) and a high-pressure buffer outer cylinder (14) to form a low-pressure and high-pressure two-stage series double-cavity buffer. The external structure of the device consists of two identical spring-controlled throttle valves composed of a support seat (6), a disc reed (7), a spherical valve core (8) and a throttle valve seat (9), which are respectively placed in the low and high pressure stages. The inner cavity of the buffer piston rod constitutes a low-pressure and high-pressure two-stage buffer, the former is used for normal take-off and landing, and the latter is used for crash-resistant buffer. It can not only meet the crash resistance performance requirements of the super landing gear, but also meet the take-off and landing performance requirements of the landing gear. The buffer is an oil-gas separation type. When the ground is shut down, the low-pressure air chamber (3) can be charged and deflated through the air filling and deflation nozzle (1) at the bottom of the low-pressure air chamber (3), so as to adjust the length of the buffer during shutdown. Then adjust the height of the helicopter's center of gravity to facilitate ground crews to carry out operations such as mounting weapons or loading and unloading cargo on the helicopter.

Description

Two-stage series-connected double-chamber buffer

1. Technical field

The invention belongs to the configuration field of shock absorbers in aircraft landing gear.

2. Technical background

World War I aircraft already had shock-absorbing landing gear that used rubber cords wrapped around axles and fastened to support struts for shock absorption. Due to the inefficiency of bungee landing gear, there were other shock-absorbing designs at the time. These include steel disc springs, steel leaf springs, air and oil and other types of cushioning struts. The oil-pneumatic struts were only adopted in 1918. Up to now, most of the aircraft landing gears have adopted oil-pneumatic buffers. The internal design of oil-air shock absorbers is constantly being improved and developed. In order to improve the capacity absorption capacity of the landing gear buffer and reduce the dynamic load of the landing gear during landing, especially ground taxiing and maneuvering, designers have developed a single-stage double-cavity buffer (that is, there are two low-pressure and high-pressure buffers in one buffer. air cavity), and a spring-controlled throttle valve is added in the cushioning strut piston of the dual-chamber type, so that the valve will be opened at a given load, thereby improving the cushioning performance of the cushioning strut.

Especially for helicopters, the double-cavity buffer can significantly improve the crash resistance of the landing gear, so it is currently one of the preferred buffer structures for the crash-resistant landing gear buffer of the helicopter. However, according to the standards of technologically developed countries such as Europe and the United States, as the first energy-absorbing system that touches the ground when a helicopter crashes and lands, the crash-resistant landing gear plays a vital role in absorbing the energy of the crash and reducing overload. 55%～60% of the crash power, thereby effectively improving the survival rate of the occupant when the helicopter crashes and lands. The landing gear designed with the existing single-stage double-cavity buffer structure, because the take-off and landing buffer and the crash-resistant buffer share the buffer stroke of the same piston rod, the stroke that can actually be used for the crash-resistant buffer is very limited. Landing gear is difficult to meet the design requirements of helicopter crash resistance.

In addition, for heavy-duty helicopters, in order to realize the crash-resistant function in the existing single-stage double-chamber buffer, it is necessary to reserve part of the crash-resistant buffer stroke in the already limited buffer stroke of its landing gear, causing the heavy-duty helicopter to crash. The landing gear take-off and landing buffer travel is too short, the landing gear buffer process is not stable during normal take-off and landing, and the landing power absorption is poor.

3. Contents of the invention

Purpose of the present invention: the landing gear designed with the existing single-stage double-cavity buffer structure can actually be used for take-off and landing buffer and crash-resistant buffer due to the buffer stroke of the same piston rod used for take-off and landing buffer and crash-resistant buffer The stroke of buffering is all very limited, it is difficult to reach the design requirement of modern helicopter landing gear. The invention separates the high-pressure and low-pressure air chambers in the single-stage double-chamber buffer to form a two-stage serial double-chamber buffer formed by connecting two single-stage single-chamber buffers in high pressure and low pressure in series, so that the take-off of the buffer The landing buffer stroke is separated from the crash-resistant buffer stroke to overcome the above disadvantages. In addition, it is also possible to adjust the extended length of the buffer when it is stopped on the ground through the filling and deflation nozzle at the bottom of the low-pressure air cavity of the two-stage series double-cavity buffer.

The technical scheme of the present invention: the whole external frame of the two-stage series double-cavity buffer is composed of the low-pressure buffer piston rod, the low-pressure buffer outer cylinder, the high-pressure buffer piston rod and the high-pressure buffer outer cylinder; , ultimatum reed, spherical valve core and throttle valve seat constitute the spring-controlled throttle valve of the low-pressure buffer, and the throttle valve is fixed on the piston rod of the low-pressure buffer by the throttle valve fixing thread ring; The buffer throttle valve is composed of the same parts, and is fixed on the outer cylinder of the low-pressure buffer and the piston rod of the high-pressure buffer in the same way; both the high and low-pressure buffers use the same floating piston to separate the oil from the air. A low-pressure air chamber, a low-pressure buffer oil chamber, a high-pressure air chamber and a high-pressure buffer oil chamber are respectively formed, and the floating range of the two floating pistons is limited by a limit ring; a filling and deflation nozzle is installed at the bottom of the low-pressure air chamber , so as to adjust the extended length of the buffer when the vehicle is stopped on the ground. This whole constitutes a two-stage series double-chamber buffer composed of two single-stage single-chamber buffers connected in series at high pressure and low pressure. The low-pressure air chamber of the first-stage single-chamber buffer has a low inflation pressure and is used for normal take-off and landing buffers.

Beneficial effects of the present invention:

(a), the take-off and landing buffer stroke and the crash-resistant buffer stroke of the buffer are separated, so that the take-off and landing buffer and the crash-resistant buffer of the helicopter have obtained sufficient buffer strokes respectively, so the buffer can meet the requirements of the helicopter landing gear design Crash-resistant performance requirements, and can meet the take-off and landing performance requirements of heavy-duty helicopters, especially meet the design requirements of heavy-duty armed helicopters for landing gear;

(b) The buffer is an oil-air separation type. When the ground is stopped, the low-pressure air cavity can be charged and deflated through the charging and deflation nozzle at the bottom of the low-pressure air cavity of the buffer to adjust the length of the buffer extension and the height of the helicopter's center of gravity. , It is convenient for the ground crew to carry out operations such as mounting weapons or loading and unloading cargo on the helicopter.

4. Description of drawings

Accompanying drawing 1 is a schematic diagram of the composition of two-stage series-connected double-cavity buffers.

Label names in the figure: 1. Filling and deflation nozzle, 2. Low-pressure buffer piston rod, 3. Low-pressure air cavity, 4. Floating piston, 5. Limiting ring, 6. Support seat, 7. Reed reed, 8 , Spherical spool, 9, Throttle valve seat, 10, Throttle valve fixed thread ring, 11, Low pressure buffer oil chamber, 12, Low pressure buffer outer cylinder and high pressure buffer piston rod, 13, High pressure Air cavity, 14, high pressure level buffer outer cylinder, 15, high pressure level buffer oil chamber.

5. Specific implementation

As shown in accompanying drawing 1, it is a schematic structural diagram of the two-stage series-connected double-cavity buffer of the present invention. The working principle of this two-stage series-connected double-cavity buffer will be explained here.

For the two-stage serial double-cavity buffer shown in accompanying drawing 1, its working principle is:

(a) When the piston rod 2 of the low-pressure buffer is subjected to the impact load of the normal working state, the low-pressure single-chamber buffer starts to work first, and the oil in the oil chamber 11 of the low-pressure buffer flows to the other side through the throttle valve under pressure. side, and push the floating piston 4 to compress the gas in the low-pressure air chamber 3, in which the spring-controlled throttle valve composed of the support seat 6, the disc reed 7, the spherical valve core 8 and the throttle valve seat 9 is a low-pressure buffer. When the impact load is large, the spherical spool 8 is flushed away by the oil, and the variable oil hole is opened to increase the oil flow and avoid load surges. At this time, the high-pressure buffer does not participate in the work;

(b) When the impact load on the piston rod 2 of the low-pressure buffer caused by a crash or other abnormal working conditions is too large, so that the oil pressure on the floating piston of the high-pressure buffer is greater than the initial pressure of the high-pressure air chamber 13, The high-pressure stage buffer begins to participate in the work, and its working principle and throttle valve are consistent with the low-pressure stage buffer.

(c) When the buffer reaches the maximum compression stroke, the buffer involved in the buffering work is affected by the potential energy of the stored air spring and enters the rebound buffering process. At this time, the floating piston 4 of the low-pressure or high-pressure buffer pushes the oil through Respective throttle valve return flow.

(d) During the entire buffering and rebounding process, the buffer absorbs and dissipates the landing impact energy through the oil damping force generated by the oil flowing through the throttle valve.

(e) The buffer is an oil-gas separation type. When the ground is stopped, the low-pressure air chamber 3 is charged and deflated through the inflation and deflation nozzle 1 at the bottom of the buffer's low-pressure air chamber 3 to adjust the extension length of the buffer.

Claims (1)

1. A two-stage series double-cavity buffer: (a) The top end of the low-pressure buffer piston rod (2) is put into the inner cylinder of the low-pressure buffer outer cylinder and the high-pressure buffer piston rod (12), and the high-pressure buffer outer cylinder (14) is set on the The outer cylinder of the low-pressure buffer and the tail of the piston rod (12) of the high-pressure buffer constitute the entire external structure of the low-pressure and high-pressure two-stage series-connected double-cavity buffer; (b) The throttle valve seat (9) is installed in the inner cavity of the support seat (6), the spherical valve core (8) is placed in the inner cavity of the throttle valve seat (9), and the reed (7) is placed in the spherical valve Between the recess at one end of the core (8) and the inner bottom of the support seat (6), a spring-controlled throttle valve of the low-pressure buffer is formed. on the inner circular wall step at the top end of the piston rod (2) of the shock absorber; similarly, the composition of the spring-controlled throttle valve of the high-pressure shock absorber is exactly the same as that of the low-pressure stage shock absorber, the difference is that the The spring-controlled throttle valve of the high-pressure buffer is fixed on the outer cylinder of the low-pressure buffer and the inner circular wall step at the tail of the piston rod (12) of the high-pressure buffer through another throttle fixing threaded ring; (c) The floating piston (4) is horizontally installed in the inner chamber of the piston rod (2) of the low-pressure buffer to separate the oil from the air to form the low-pressure air in the left half of the inner chamber of the piston rod (2) of the low-pressure buffer Cavity (3) and the low-pressure buffer oil chamber (11) in the right half of the inner cavity; ) in the inner cavity, forming the high-pressure air cavity (13) in the left half of the inner cavity of the low-pressure buffer outer cylinder and the high-pressure buffer piston rod (12) and the high-pressure buffer oil cavity (15) in the right half of the inner cavity ; It is characterized in that limit rings (5) are respectively arranged on the inner wall of the piston rod (2) of the low-pressure buffer, the outer cylinder of the low-pressure buffer and the inner wall of the piston rod (12) of the high-pressure buffer to limit the pressure of the low pressure. The range of motion of the floating piston in the cavity of the first-stage buffer piston rod (2) and the range of motion of the floating piston in the outer cylinder of the low-pressure buffer piston rod and the inner cavity of the high-pressure buffer piston rod (12), in the low-pressure buffer piston rod ( 2) A filling and deflation nozzle (1) communicating with the low-pressure air chamber (3) is installed longitudinally on the outer cylinder at the bottom.

Images