JPH0925902A - Drop preventive thin type air cylinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain the increase of the thickness of an air cylinder in the axial direction as far as possible by incorporating a permanent magnet between the piston of the air cylinder and the end cover. SOLUTION: A end cover 2 made of a magnetic substance is fitted to a cylinder body 3 by means of C-shaped retaining ring 6. A permanent magnet 4 is fixed to a piston 1. When the piston 1 reaches its upper end by an air pressure, the end cover 2 attracts the permanent magnet 4, and even if the air pressure is removed, the piston 1 and the movable part fitted to a piston rod 5 is retained to the upper end position thereof against gravity. Further, it is similar when the permanent magnet 4 is fixed to the end cover 2, and the piston 1 is made of a magnetic substance. As a result, the conventional thin type air cylinder can be provided with a drop preventive function with the thickness in the axial direction unchanged, and further a small-size, inexpensive device can be enabled.

Description

Detailed Description of the Invention

[Field of Industrial Application] Conventionally, a field in which a thin air cylinder is used, and a field in which it is desired to hold a movable portion at a terminal position after completion of work.

[Prior Art] An air cylinder with fall prevention. .

[Problems to be Solved by the Invention] In a thin air cylinder, in particular, to provide a small and inexpensive fall prevention mechanism which makes it possible to suppress (avoid increase) the increase in axial thickness as much as possible. .

[Means for Solving the Problem] The movable portion is held by the attractive force of a permanent magnet mounted between the piston and the end cover.

[Operation] The operation will be described with reference to the drawings. FIG.
It is an axial sectional view of the present invention, the cylinder body (3)
An end cover (2) made of a magnetic material is attached to the base by a C-shaped retaining ring (6). A permanent magnet (4) is fixed to the piston (1). The piston (1)
When reaching the upper end due to the air pressure, the end cover (2) and the permanent magnet (4) are attracted to each other, and even if the piston (1) and the movable part attached to the piston rod (5) lose the air pressure, It is held at the top by gravity.
In the above description, the direction in which the piston rod extends is described as upward, but it is obvious to those skilled in the art that the opposite case is possible. Further, the same applies when the permanent magnet is fixed to the end cover (2) and the piston (1) is made of a magnetic material.

[Embodiment] Cylinder inner diameter 63 mm, stroke 50 mm. Moving part weight 1kgf, permanent magnet attraction 2
kgf. As a result of implementing the above dimensions, clear results have been obtained that support the technical idea of the present invention.

[Advantages of the Invention] The advantages of the present invention are that the conventional thin air cylinder can have a fall prevention function while keeping the axial thickness as it is, and the device is small and inexpensive. This is the point that made it possible.

[Brief description of drawings]

FIG. 1 is an axial sectional view of the present invention.

[Explanation of symbols]

 (1) is a piston. (2) is a flange. (3) is the cylinder body. (4) is a permanent magnet. (5) is a piston rod. (6) is a C-shaped retaining ring.

Claims (1)

[Claims] 1. A thin air cylinder with fall prevention, characterized in that a permanent magnet (4) is incorporated between a piston (1) and an end cover (2) of the air cylinder.