JPS6114668Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a gas-filled cylinder device used, for example, as a shock absorber for automobiles.

In conventional shock absorbers of this type, when a car vibrates, the piston moves relatively with its piston rod within the cylinder, and the action of the gas or oil sealed in the cylinder causes the cylinder and piston to move. There are known devices that reduce relative movement and thereby reduce vibrations of the automobile.

However, in conventional shock absorbers, when the piston rod is attached to the piston, a nut is screwed onto the piston rod, so the nut loosens and comes off from the piston rod due to the vibrations of the car, and The piston sometimes came off from the piston rod. If this happens, the shock absorber will no longer function as a shock absorber, and if the shock absorber is removed from the car in this condition, the piston rod will be forced out of the cylinder due to the pressure of the gas sealed inside the cylinder. It jumped out easily and was very dangerous.

This idea was made in view of the above circumstances,
An object of the present invention is to provide a gas-filled cylinder device that can reliably prevent a piston rod from jumping out of a cylinder by providing a projection at a predetermined portion of the piston rod.

An embodiment of this invention will be described below based on the drawings. In the figure, 1 is a cylinder, and this cylinder 1 consists of an outer cylinder 2, an inner cylinder 3, and a bottom cover 4 and a top cover 5 provided at the lower and upper ends of these cylinders, respectively. Outer cylinder 2 and inner cylinder 3
A space (reservoir chamber) 6 is provided between the two. This space 6 is communicated with the inside of the inner cylinder 3 through a communication hole 7 provided at the lower part of the inner cylinder 3. Furthermore, a piston 8 is slidably provided within the inner cylinder 3. A rod hole 9 is formed in the center of the piston 8, and one-way valves (damping force generating valves) 10, 1 are provided on both sides of the rod hole 9.
1 are provided in opposite directions. Further, one end portion of a piston rod 12 formed in a small diameter is fitted into the rod hole 9 of the piston 8, and a nut 1 is inserted into this one end portion via a washer 13.
4 is screwed together to position the damping force generating valve in the axial direction of the piston rod 12. The other end of the piston rod 12 passes through the upper cover 5 and a rod guide 15 provided within the upper cover 5 in a vertically movable manner and projects to the outside. A mounting ring 16 is provided at the other end of the piston rod 12. Further, a mounting ring 17 is provided at the lower end of the cylinder 1. An annular groove 19 is formed above the piston 8 on the outer periphery of the inner end of the sliding surface of the piston rod 12, and a C ring 20 is fitted in this groove 19 so as to protrude radially outward from the outer periphery of the piston rod 12. installed. Also,
A protrusion 18 is fitted into the piston rod 12 at an upper portion of the piston 8. This protrusion 18
consists of a cylinder 21 with a bottom, and a C ring 2 is inserted into this hole.
0, and is attached to the piston rod 12 by the expansion force of this C ring 20, and serves as a receiver for a one-way valve. The top surface of the bottomed cylinder 21 is flat and slightly higher than the top surface of the C-ring 20. In addition, 22 is a piston upper chamber, 23
is the lower chamber of the piston. And piston upper chamber 2
2, the lower piston chamber 23 and the space 6 are filled with oil, and furthermore, the upper part of the space 6 is filled with spring means sealed in the cylinder, that is, gas.

When the mounting ring 16 and the mounting ring 17 are mounted on the car body and the wheels respectively, and the car vibrates, the cylinder 1 and the piston 8 move up and down relative to each other. 22 of oil flows into the piston lower chamber 23 through the one-way valve 10. At this time, the oil in the space 6 is also pushed by the gas above and flows into the piston lower chamber 23 through the communication hole 7. Further, at the end of the extension stroke, the upper surface of the bottomed cylinder 21 of the protrusion 18 comes into contact with the lower surface of the rod guide 15, and the upward movement of the piston rod 12 is stopped. That is, the protrusion 18 serves as a stopper. At this time, the area of the contact surface (upper surface) of the bottomed cylinder 21 against the rod guide 15 is relatively large, so the rod guide 15 is not deformed by the bottomed cylinder 21. In addition, during the retraction stroke, the oil in the piston lower chamber 23 is removed by the one-way valve 11.
It flows into the piston upper chamber 22 through the piston. At this time,
The oil in the piston lower chamber 23 also flows into the space 6 through the communication hole 9. In this way, the relative movement between the cylinder 1 and the piston 8 can be alleviated by the action of the oil and gas, thereby making it possible to alleviate the vibrations of the automobile.

By the way, in such a cylinder device, the screwing of the nut 14 to the piston rod 12 may loosen due to vibrations of the automobile, and the nut 14 may become detached from the piston rod 12. In this state, when the cylinder device is removed from the automobile, the gas in the upper part of the space 6 presses the oil in the space 6 and the lower piston chamber 23, and the piston rod 12 is raised by the action of these oil and gas. piston rod 1
When the piston rod 2 rises, the protrusion 18 comes into contact with the rod guide 15 and the piston rod 12 is stopped, so the piston rod 12 does not jump out of the cylinder 1. Furthermore, even if the bottomed cylinder 21 should come off from the piston rod 12, the C-ring 20 will come into contact with the lower surface of the rod guide 15 and stop the piston rod 12, so that the piston rod 12 can be removed from the cylinder 1.
It won't jump out.

In the above embodiment, this invention was applied to a gas-filled hydraulic shock absorber consisting of a double cylinder.
The present invention is not limited to this, and can also be applied to a single cylinder such as a gas spring.

As explained above, according to this invention, there is provided a bottomed cylinder, a piston slidably provided in the cylinder, a rod guide provided at the open end of the cylinder, and a piston provided at one end having a small diameter. a piston rod that is removably attached via a nut and whose other end passes through the rod guide and protrudes out of the cylinder; and a groove formed on the outer periphery of the inner end side of the piston rod sliding surface at a position above the piston. a C-shaped ring attached to the groove so as to protrude radially outward from the outer periphery of the piston rod, and a C-shaped ring located above the piston and fitted to and attached to the piston rod to accommodate the C-shaped ring. , a bottomed cylindrical protrusion whose upper end protrudes slightly above the C-shaped ring, and a gas sealed within the cylinder so as to cause the piston rod to constantly protrude outside the cylinder; At the end of the extension stroke during normal operation of a gas-filled cylinder device, the C-shaped ring does not come into contact with the rod guide, but the top surface of the large bottomed cylindrical projection comes into contact with the bottom surface of the rod guide, so the rod guide It is safe because it can stop the piston rod without causing damage and reliably prevent the piston rod from jumping out of the cylinder.Also, even if the nut screwed onto the piston rod loosens due to vibration and comes off, the rod guide Since the top surface of the bottomed cylindrical protrusion comes into contact with the rod guide without the C-shaped ring coming into contact with the rod guide, the piston rod can be stopped without damaging the rod guide, and the piston rod can be surely prevented from jumping out from the cylinder. Even if the bottomed cylindrical protrusion comes off from the piston rod, the C-shaped ring will come into contact with the bottom surface of the rod guide and stop the piston rod, so there is a double safety measure. This makes it possible to ensure safety, and the bottomed cylindrical protrusion can also serve as a receiver for the one-way valve and as a stopper for the piston rod. The length in the axial direction can be made relatively short, the number of parts can be reduced, and manufacturing costs can be lowered.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional view showing an embodiment of this invention. 1... Cylinder, 6... Space (reservoir chamber),
8... Piston, 12... Piston rod, 14
...Natsuto, 15... Rod guide, 18... Protrusion.

Claims (1)

[Scope of utility model registration request] A bottomed cylinder, a piston slidably provided in the cylinder, a rod guide provided at an open end of the cylinder, and the piston removably attached to one end having a small diameter via a nut. a piston rod whose end passes through the rod guide and protrudes outside the cylinder; a groove formed at an upper position of the piston on the outer periphery of the inner end of the piston rod sliding surface; and a groove extending radially outward from the outer periphery of the piston rod. A C-shaped ring attached to the groove so as to protrude from the piston, and a C-shaped ring positioned above the piston and fitted to the piston rod, the upper end being slightly above the C-shaped ring. A gas-filled cylinder device comprising a bottomed cylindrical protrusion that projects, and a gas that is sealed in the cylinder so that the piston rod always projects out of the cylinder.