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EP-4446596-B1 - HYDRAULIC ACTUATOR

EP4446596B1EP 4446596 B1EP4446596 B1EP 4446596B1EP-4446596-B1

Inventors

  • OONO, SHINGO

Dates

Publication Date
20260513
Application Date
20221014

Claims (6)

  1. A fluid pressure actuator (10) comprising: an actuator body portion (100) comprising a tube (110) having a cylindrical shape and that is conf igured to expand and contract under pressure of a fluid, and a sleeve (120) that is a structure in which cords oriented in a predetermined direction are woven and covers an outer peripheral surface of the tube (110); and a sealing mechanism (200, 200A) that seals the end of the actuator body portion (100) in the axial direction (D AX ) of the actuator body portion (100), wherein the sealing mechanism (200, 200A) comprises: a sealing member (210, 210A) onto which the actuator body portion (100) is inserted; a restricting member (230) provided on an outer peripheral surface of the actuator body portion (100) inserted onto the sealing member (210, 210A) and that restricts the actuator body portion (100); and a locking member (220) that locks the sleeve (120) to the sealing member (210, 210A), the sealing member (210, 210A) comprises: a body portion (212) onto which the tube (110) is inserted; a head portion (211) provided further outside than the body portion (212) in the axial direction (D AX ) and an intermediate portion (213) provided between the body portion (212) and the head portion (211), wherein the intermediate portion (213): is smaller in size in the radial direction (D R ) of the actuator body portion (100) than the head portion (211); and has an enlarged diameter part (214, 214A) that is larger than the body portion (212) toward the radial direction outside of the actuator body portion (100), and the locking member (220) is configured to be compressed and deformed to fill a space formed between the restricting member (230) and the intermediate portion (213), characterized in that the locking member (220) is formed of a material having an anisotropy in which the strength in the axial direction (D AX ) is lower than that in the radial direction (D R ) to facilitate compressive deformation in the axial direction (D AX ).
  2. The fluid pressure actuator (10) according to claim 1, wherein the enlarged diameter part (214, 214A) increases in diameter from the head portion (211) toward the body portion (212).
  3. The fluid pressure actuator (10) according to claim 1 or 2, wherein the distance between the restricting member and the intermediate portion (213) decreases in diameter from the head portion (211) toward the body portion (212).
  4. The fluid pressure actuator (10) according to any one of claims 1 to 3, wherein the locking member is formed of a material containing aluminum.
  5. The fluid pressure actuator (10) according to any one of claims 1 to 4, wherein the locking member is formed by winding a wire (220, 220A) around an outer peripheral surface of the intermediate portion (213).
  6. The fluid pressure actuator (10) according to any one of claims 1 to 5, wherein an end portion of the sleeve (120) in the axial direction is folded back via the locking member.

Description

[Technical Field] The present invention relates to a fluid pressure actuator that expands and contracts a tube using a gas or liquid, and more particularly to a so-called McKibben type fluid pressure actuator. [Background Art] Conventionally, a structure (so-called McKibben type) having a rubber tube (tubular body) that expands and contracts by air pressure and a sleeve (mesh reinforcing structure) that covers the outer peripheral surface of the tube is widely used as a fluid pressure actuator that expands and contracts the tube as described above. Both ends of the actuator body portion constituted by the tube and the sleeve are sealed using a sealing member formed of metal. The sleeve is a cylindrical structure in which a high-tension fiber such as a polyamide fiber or a metal cord is woven, and the expansion motion of the tube is restricted to a predetermined range. In order to prevent the sleeve from pulled out of the sealing member due to the load during the operation of the fluid pressure actuator of the McKibben type, a structure is known in which the sleeve is locked to a flange portion formed on the sealing member using a locking member (locking ring) (For example, Patent Literatures 1 and 2). [Citation List] [Patent Literature] [Patent Literature 1] Japanese Patent Laid-Open No. 2018-035930[Patent Literature 2] JP 2020 097953 A [Summary of Invention] According to the structure using the aforementioned locking member, the failure of the fluid pressure actuator can be prevented, and the durability of the fluid pressure actuator can be improved. However, there are cases where high pressure is applied to the fluid pressure actuator (such as when the actuator is hydraulically driven), and higher durability has been required. Therefore, the following invention has been made in view of such a situation, and it is an object of the present invention to provide a fluid pressure actuator which can more reliably prevent the sleeve from being pulled out of the sealing member while using a locking member for locking the sleeve. An embodiment of the present invention is a fluid pressure actuator including an actuator body portion comprising a tube having a cylindrical shape and that is configured to expand and contract under pressure of a fluid, and a sleeve that is a structure in which cords oriented in a predetermined direction are woven and covers an outer peripheral surface of the tube, and a sealing mechanism that seals the end of the actuator body portion in the axial direction of the actuator body portion. The sealing mechanism includes a sealing member onto which the actuator body portion is inserted, a restricting member provided on an outer peripheral surface of the actuator body portion inserted onto the sealing member and that restricts the actuator body portion, and a locking member that locks the sleeve to the sealing member, The sealing member includes a body portion onto which the tube is inserted, a head portion provided further outside than the body portion in the axial direction, and an intermediate portion provided between the body portion and the head portion. The intermediate portion is smaller in size in the radial direction of the actuator body portion than the head portion and has an enlarged diameter part that is larger than the body portion toward the radial direction outside of the actuator body portion. The locking member is configured to be compressed and deformed to fill a space formed between the restricting member and the intermediate portion. The locking member is formed of a material having an anisotropy in which the strength in the axial direction DAX is lower than that in the radial direction DR to facilitate compressive deformation in the axial direction. [Brief Description of Drawings] [FIG. 1] FIG. 1 is a side view of a fluid pressure actuator 10.[FIG. 2] FIG. 2 is a partially enlarged perspective view of the fluid pressure actuator 10.[FIG. 3] FIG. 3 is a partially sectional view along the axial direction DAX of a sealing mechanism 200.[FIG. 4] FIG. 4 is a partially sectional view along the axial direction DAX of the sealing mechanism 200 before a caulking ring 230 is caulked.[FIG. 5] FIG. 5 is a partially sectional view along the axial direction DAX of a sealing mechanism 200 A for modified example. [Description of Embodiments] Hereinafter, the embodiment will be described based on the drawings. The same functions and structures are denoted by the same or similar reference numerals, and the description thereof will be omitted accordingly. (1) Overall schematic configuration of the fluid pressure actuator FIG. 1 is a side view of the fluid pressure actuator 10 according to the present embodiment. As shown in FIG. 1, the fluid pressure actuator 10 includes an actuator body portion 100, a sealing mechanism 200, and a sealing mechanism 300. The sealing mechanism 200 and the sealing mechanism 300 seal both ends of the actuator body portion 100 in the axial direction DAX. Speci