A tapered surface locking type carbon fiber composite piston rod

Abstract

A conical surface locking type carbon fiber composite piston rod, comprising: a front outer lining (2) is coated on the outer surface of a carbon fiber front piston rod (1), and one end of the carbon fiber front piston rod (1) is an expanded cone; a rear outer lining (8) is coated on the outer surface of a carbon fiber rear piston rod (7), and one end of the carbon fiber rear piston rod (7) is an expanded cone; the conical end of the carbon fiber front piston rod (1) and the front outer lining (2) are fixedly connected to a metal piston (4) through a front conical back nut (3), and the conical end of the carbon fiber rear piston rod (7) and the rear outer lining (8) are fixedly connected to the metal piston (4) through a rear conical back nut (6); sealing structures are respectively provided on the two end faces where the metal piston (4) is connected to the carbon fiber front piston rod (1) and the carbon fiber rear piston rod (7), and sealing rings (5) are provided at the two sealing structures. The piston rod body of the present invention adopts a carbon fiber composite material, which can reduce the weight of the piston rod on the premise of ensuring sufficient stiffness and strength.

Description

Technical Field

[0001] The present invention relates to the technical field of servo mechanisms, and particularly to a conical surface locking type carbon fiber composite material piston rod, which adopts a lightweight design and can be used for the electro-hydraulic servo mechanism of a launch vehicle. Background Art

[0002] In recent years, China has entered a period of high-density launch of launch vehicles, and it is necessary to improve the effective carrying capacity of the rockets. Lightweight of on-board equipment is one of the effective ways to improve the carrying capacity of rockets. The development and application of new materials with high strength and low density are one of the effective ways to achieve lightweight. As a lightweight material (density: 1.76 - 1.80 g / cm3), carbon fiber reinforced composite material CFRP has high specific strength and specific modulus, and can adapt to the working environment of long time, high and low temperature alternating and vacuum in outer space. At present, carbon fiber composite materials have been widely used in practical engineering applications such as rocket pressurized gas cylinders, some cabin sections and structural parts of satellite payloads.

[0003] A servo mechanism supporting a launch vehicle adopts an integral design, achieving a relatively high specific power; the piston rod, as a load-bearing structural part of the servo mechanism, bears large structural forces and hydraulic pressures, and sufficient stiffness and strength need to be ensured. It is usually processed with steel materials (density: 7.85 g / cm3), and its weight is generally large, usually accounting for 10% - 15% of the total weight of a servo mechanism. Moreover, the structure of the piston rod is simple, and it is difficult to reduce its weight by relying on traditional structural optimization design methods. Therefore, it is necessary to start from the material aspect to achieve its lightweight. Summary of the Invention

[0004] The present invention provides a conical surface locking type carbon fiber composite material piston rod to solve the technical problem of reducing the weight of the piston rod while ensuring sufficient stiffness and strength.

[0005] The present invention provides a conical surface locking type carbon fiber composite material piston rod, which includes: a carbon fiber front piston rod, a front outer lining, a front conical back nut, a metal piston, a sealing ring, a rear conical back nut, a carbon fiber rear piston rod and a rear outer lining; wherein, the outer surface of the carbon fiber front piston rod is coated with the front outer lining, and one end of the carbon fiber front piston rod is an expanded cone; the outer surface of the carbon fiber rear piston rod is coated with the rear outer lining, and one end of the carbon fiber rear piston rod is an expanded cone; the conical end of the carbon fiber front piston rod and the front outer lining are fixedly connected to the metal piston through the front conical back nut, and the conical end of the carbon fiber rear piston rod and the rear outer lining are fixedly connected to the metal piston through the rear conical back nut; sealing structures are respectively provided on the two end faces where the metal piston is connected to the carbon fiber front piston rod and the carbon fiber rear piston rod, and sealing rings are provided in the two sealing structures.

[0006] Preferably, the carbon fiber front piston rod and the rear piston rod respectively have hollow inner cavities, and displacement sensors are provided in the inner cavities.

[0007] Preferably, there is a gap between the front conical back nut and the front outer liner, and between the rear conical back nut and the rear outer liner.

[0008] Preferably, the front conical back nut and the rear conical back nut have an external hexagonal structure.

[0009] Preferably, the carbon fiber front piston rod and the front outer liner are adhesively cured and connected by an epoxy resin adhesive; the front conical back nut is threadedly connected to the metal piston.

[0010] Preferably, the carbon fiber rear piston rod and the rear outer liner are adhesively cured and connected by an epoxy resin adhesive; the rear conical back nut is threadedly connected to the metal piston.

[0011] Preferably, the sealing structure is a groove.

[0012] Preferably, there are gaps between the front conical back nut and the front outer liner, and between the rear conical back nut and the rear outer liner, respectively.

[0013] The present invention uses a carbon fiber composite piston rod body to replace the conventional metal body, achieving a lightweight design of the piston rod and being able to reduce the weight of the piston rod while ensuring sufficient stiffness and strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic structural view of a conical surface locking type carbon fiber composite piston rod.

[0015] Figure 2 is a schematic view of the connection between the metal piston and the piston rod.

[0016] Figure 3 is a schematic design view of the conical back nut structure. DETAILED DESCRIPTION OF THE INVENTION

[0017] The structure of the conical surface locking type carbon fiber composite piston rod of the present invention is as Figure 1 shown, and it includes: a carbon fiber front piston rod 1, a front outer liner 2, a front conical back nut 3, a metal piston 4, a sealing ring 5, a rear conical back nut 6, a carbon fiber rear piston rod 7, and a rear outer liner 8.

[0018] The outer surface of the carbon fiber front piston rod 1 is coated with the front outer liner 2, and one end of the carbon fiber front piston rod 1 is an expanded cone; the outer surface of the carbon fiber rear piston rod 7 is coated with the rear outer liner 8, and one end of the carbon fiber rear piston rod 7 is an expanded cone.

[0019] The conical end of the carbon fiber front piston rod 1 and the front outer liner 2 are fixedly connected to the metal piston 4 through the front conical back nut 3, and the conical end of the carbon fiber rear piston rod 7 and the rear outer liner 8 are fixedly connected to the metal piston 4 through the rear conical back nut 6.

[0020] There are sealing structures on the two end faces where the metal piston 4 is connected to the carbon fiber front piston rod 1 and the carbon fiber rear piston rod 7, and there are sealing rings 5 in the two sealing structures.

[0021] The connection between the carbon fiber front piston rod 1, the carbon fiber rear piston rod 7 and the metal piston 4 involves the connection problem of metal materials and composite materials. And because a displacement sensor needs to be installed inside the piston rod, and the inside and outside of the piston rod require sealed isolation, a sealing structure needs to be designed at the connection of the carbon fiber front piston rod 1, the carbon fiber rear piston rod 7 and the metal piston 4 to prevent the oil fluid outside the piston rod from seeping into the inside at the connection and affecting displacement measurement, etc.

[0022] As Figure 1 shown, the carbon fiber front piston rod 1 and the front outer lining 2 are fixedly connected to the metal piston 4 through the front tapered back nut 3, and the carbon fiber rear piston rod 7 and the rear outer lining 8 are fixedly connected to the metal piston 4 through the rear tapered back nut 6. Here, the tapered surface locking method is adopted to realize the firm connection between the carbon fiber composite material piston rods on both sides and the metal piston. At the same time, in order to ensure the sealing performance after connection, a sealing structure is designed on the end faces where the metal piston 4 is connected to the carbon fiber front piston rod 1 and the carbon fiber rear piston rod 7, and there is a sealing ring 5 on each side to isolate the oil fluid on both sides from entering the inside of the piston rod.

[0023] Specifically, as Figure 1 shown, the carbon fiber front piston rod 1 and the front outer lining 2 are adhesively cured and connected by epoxy resin adhesive, and then fixedly connected to the metal piston 4 through the front tapered back nut 3, where the front tapered back nut 3 is threadedly connected to the metal piston 4; the carbon fiber rear piston rod 7 and the rear outer lining 8 are adhesively cured and connected by epoxy resin adhesive, and then fixedly connected to the metal piston 4 through the rear tapered back nut 6, where the tapered back nut 6 is threadedly connected to the metal piston 4. On the end faces where the metal piston 4 is connected to the carbon fiber front piston rod 1 and the carbon fiber rear piston rod 7, a face seal structure is designed, and there is a sealing ring 5 on each side to isolate the oil fluid on both sides from entering the inside of the piston rod.

[0024] There is a 0.1 mm gap between the front tapered back nut 3, the rear tapered back nut 6 and the outer lining. After the tapered back nuts are tightened in place, it will not affect the combination of the front outer lining 2, the rear outer lining 8 and the piston rod body. The front tapered back nut 3 and the rear tapered back nut 6 directly press the carbon fiber front piston rod 1 and the carbon fiber rear piston rod 7 through the tapered surfaces respectively, as Figure 2 shown, to achieve the effect of tapered surface locking and fixing. One end of the front tapered back nut 3 and the rear tapered back nut 6 has an external hexagonal structure, as Figure 3 shown, which is convenient for tightening and applying torque.

[0025] Specifically, as Figure 2As shown, the front conical back nut 3 and the rear conical back nut 6 directly extrude the carbon fiber front piston rod 1 and the carbon fiber rear piston rod 7 respectively through the conical surfaces. The conical surface of the front conical back nut extrudes on the conical surface of the carbon fiber layer on the side of the carbon fiber front piston rod 1 close to the metal piston 4, and the conical surface of the rear conical back nut extrudes on the conical surface of the carbon fiber layer on the side of the carbon fiber rear piston rod 1 close to the metal piston 4, so as to achieve the conical surface locking and fixing effect. At the same time, the front conical back nut 3 and the rear conical back nut 6 do not contact the outer lining. After the conical back nuts are tightened in place, a 0.1 mm gap is designed and reserved in the radial direction between the front conical back nut and the front outer lining 2 and between the rear conical back nut and the rear outer lining 8 respectively, to avoid the connection failure at the glued and cured part of the outer lining and the carbon fiber piston rod, and prevent curling and the like.

[0026] The split carbon fiber piston rods at both ends of the piston are locked and fixed to the metal piston 4 through the front conical back nut 3 and the rear conical back nut 6, and combined into an integral piston rod. The present invention uses the conical surface locking of the conical back nut, and the piston rod and the metal piston can be disassembled and assembled repeatedly.

[0027] The content not described in detail in the specification of the present invention belongs to the common general knowledge of those skilled in the art.

Claims

1. A conical surface locking type carbon fiber composite piston rod, characterized in that Comprising: Carbon fiber front piston rod (1), front outer lining (2), front tapered locknut (3), metal piston (4), sealing ring (5), rear tapered locknut (6), carbon fiber rear piston rod (7) and rear outer lining (8); The outer surface of the carbon fiber front piston rod (1) is coated with the front outer lining (2), and one end of the carbon fiber front piston rod (1) is an expanded cone; the outer surface of the carbon fiber rear piston rod (7) is coated with the rear outer lining (8), and one end of the carbon fiber rear piston rod (7) is an expanded cone; The tapered end of the carbon fiber front piston rod (1) and the front outer lining (2) are fixedly connected to the metal piston (4) through the front tapered locknut (3), and the tapered end of the carbon fiber rear piston rod (7) and the rear outer lining (8) are fixedly connected to the metal piston (4) through the rear tapered locknut (6); Sealing structures are respectively provided on the two end faces where the metal piston (4) is connected to the carbon fiber front piston rod (1) and the carbon fiber rear piston rod (7), and sealing rings (5) are provided at the sealing structures; The carbon fiber front piston rod (1) and the rear piston rod (7) respectively have hollow inner cavities, and displacement sensors are provided in the inner cavities.

2. The conical surface locking type carbon fiber composite piston rod according to claim 1, wherein, There are gaps between the front tapered locknut (3) and the front outer lining (2), and between the rear tapered locknut (6) and the rear outer lining (8).

3. The conical surface locking type carbon fiber composite piston rod according to claim 1, wherein The front tapered locknut (3) and the rear tapered locknut (6) have an external hexagonal structure.

4. The conical surface locking type carbon fiber composite piston rod according to claim 1, wherein, The carbon fiber front piston rod (1) and the front outer lining (2) are adhesively cured and connected by an epoxy resin adhesive; the front tapered locknut (3) and the metal piston (4) are connected by threads.

5. The conical surface locking type carbon fiber composite piston rod according to claim 1, characterized in that, The carbon fiber rear piston rod (7) and the rear outer lining (8) are adhesively cured and connected by an epoxy resin adhesive; the rear tapered locknut (6) and the metal piston (4) are connected by threads.

6. The tapered surface locking type carbon fiber composite piston rod according to claim 1, characterized in that, The sealing structure is a groove.

7. The conical surface locking type carbon fiber composite piston rod according to claim 1, wherein, There are gaps respectively between the front tapered locknut (3) and the front outer lining (2), and between the rear tapered locknut (6) and the rear outer lining (8).

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