JPH0631232Y2 - Swing Door Steader - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to means for ensuring safety when a stay damper that assists opening and closing of a swing door is over-compressed.

(Prior art) As a stay damper interposed between a surrounding frame and a swing door to assist opening and closing, a piston is slidably housed in a cylinder filled with gas, and the piston is It is well known that the piston rod is slidably projected outward. As such a stay damper contracts, the enclosed gas is compressed and the repulsive force is strengthened.
If the bracket that holds the piston rod is broken due to the load load when the stay damper is fully contracted due to the impact of an abnormal compression force such as impact, the piston rod that is suddenly released from overcompression is compressed. The pressure of the generated gas may forcefully jump out of the cylinder, possibly harming people or objects nearby.

Therefore, in order to prevent such a danger, a part of the sealed cylinder is damaged by the action of an abnormal compression force, and the gas in the cylinder is released into the atmosphere to prevent the piston rod from protruding. A stay damper having safety measures such as that described above has been proposed (Japanese Patent Laid-Open No. 61-291216).
issue). This is for a stay damper installed in a swing door at the rear of an automobile so that a piston rod that protrudes forward due to breakage of the bracket due to an impact such as a rear-end collision does not hurt a passenger in the rear seat.

(Problems to be solved by the invention) However, in the case of this stay damper, the cylinder is damaged by exceeding a certain value of the load, so the design load and the load at the time of actual damage may differ from the design load due to a slight error in the processing and assembly of the members. There was a problem that it was difficult to ensure the certainty of operation because a considerable difference occurred between the two.

The present invention has been made in view of the above problems, and an object thereof is to provide a stay damper provided with a safety mechanism that can more reliably release the enclosed gas in the interior against abnormal contraction.

(Means for Solving the Problems) The present invention is designed such that a piston is slidably housed in a cylinder filled with gas, and the piston is inserted at the tip of a piston rod slidably inserted into the cylinder. In a swing door stay damper that supports and supports the opening and closing of the swing door by locking one of the base ends of the piston rod and the cylinder to the swing door, and the other to the surrounding frame, the cylinder extends vertically through the piston rod. A through hole that connects the inside and outside of the cylinder is formed, and a blocking part that blocks this through hole is provided at the tip of the piston rod.When the piston penetrates the deepest part of the cylinder, the blocking part is broken and the through hole is opened in the cylinder. The projection to be made to project is provided at the bottom of the cylinder so as to face the blocking portion.

(Operation) When the piston enters the deepest part of the cylinder due to an abnormal load such as impact, the projection protruding from the bottom of the cylinder breaks through the cutoff part, and the through hole that extends vertically through the piston rod communicates with the inside of the cylinder. The enclosed gas is released to the atmosphere through the holes, weakening the repulsive force of the stay damper.

(Embodiment) FIGS. 1 to 3 show an embodiment of the present invention.

In FIG. 1, 1 is a cylinder filled with gas, 2 is a piston, and 3 is a piston rod. The piston 2 is slidably accommodated inside the cylinder 1, and a passage 4 that communicates with the upper and lower sides is formed through the piston 2 vertically. The piston 2 is fixed to the tip of the piston rod 3, and the piston rod 3
Protrudes outward from the cylinder 1 in a slidable manner. The base ends of the cylinder 1 and the piston rod 3 are attached to a swing door or a frame (not shown) via brackets 5 and 6, respectively. A through hole 7 is formed in the piston rod 3 so as to extend vertically through the center portion and open to the base end portion and the tip end portion.
The bracket 6 holding the base end portion of the piston rod 3 is formed with a through hole 6A for communicating the through hole 7 with the atmosphere. Also,
At the tip of the piston rod 3, a partition wall 9 is attached to the tip of a piston nut 8 that fixes the piston 2 to the piston rod 3 as a blocking portion that faces the opening of the through hole 7 and blocks the same. This partition wall 9 is formed of a thin plate made of metal such as aluminum, copper or cast iron, and is fixed by caulking after applying a sealing adhesive to the tip of the piston nut 8. Further, a sealing adhesive is also applied to the threaded portion between the piston nut 8 and the piston rod 3. Instead of using an adhesive, the partition wall 9 is caulked and fixed to the piston nut 8 via a seal washer 11 coated with rubber as shown in FIG. 2, and the space between the piston nut 8 and the piston rod 3 is fixed. The O-ring 12 may be interposed. At the bottom of the cylinder 1, a gas filling plug 10 is provided facing the partition wall 9.
Is projected. The gas sealing plug 10 has a function of sealing a sealing hole for sealing gas in the cylinder 1 and a function of breaking the partition wall 9 when the piston 2 further enters from the most compressed position, and the tip is formed in a pointed shape. To be done. The strength of the partition wall 9 is set sufficiently weaker than the strength of the brackets 5 and 6.

Next, the operation will be described.

At normal times, the gas pressure enclosed in the cylinder 1 urges the piston rod 3 in the extension direction, and when the piston rod 3 is actuated on the compression side, the amount of gas intruded by the piston rod 3 is further compressed. By further strengthening the repulsive force, the swing door is urged toward the listening side.

By the way, when the piston 2 deeply penetrates beyond the set maximum compression position due to an abnormal impact or the like, the pressure of the enclosed gas in the cylinder 1 also becomes abnormally high. At this time, however, the partition wall fixed to the tip of the piston nut 8 is used. 9 hits the gas-filled plug 10 standing on the bottom of the cylinder 1,
The sharp tip of 0 breaks through the partition wall 9. As a result, the enclosed gas in the cylinder 1 is released into the atmosphere through the through hole 7 of the piston rod 3 and the through hole 6A of the bracket 6, and the repulsive force of the stay damper disappears. Even if 6 is damaged, there is no danger that the piston rod 3 will pop out of the cylinder 1.

A ball 13 as shown in FIG. 3 may be fixed to the tip of the piston rod 3 by caulking as a blocking portion for blocking the through hole 7. In this case, the inner surface of the piston rod 3 is enlarged behind the ball 13.

(Effects of the Invention) As described above, according to the present invention, the through hole for communicating the inside of the cylinder with the atmosphere is vertically provided in the piston rod, and the blocking portion for blocking the through hole is provided at the tip of the piston rod. When the stay damper contracts beyond the most compressed position due to an abnormal load such as impact, because a protrusion that penetrates this blocking part when entering the deepest part is provided on the bottom of the cylinder,
The projection breaks through the blocking portion and releases the enclosed gas in the cylinder through the through hole to the atmosphere, and eliminates the repulsive force of the stay damper that has become strong due to abnormal contraction. For this reason, even if the bracket that locks the stay damper is damaged because it cannot bear the load, it is possible to prevent the piston rod from jumping out of the stay damper and damaging a person or an object.

Further, since the blocking portion and the protrusion do not come into contact with each other in the normal stroke range, reliable operation can be expected by setting the strength of the blocking portion to be weak.

Therefore, according to the present invention, the safety of the stay damper against an abnormal load load is surely improved by a simple means.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a stay damper showing an embodiment of the present invention, FIG. 2 is a vertical cross-sectional view of a main part of the stay damper showing another construction of a partition wall mounting method, and FIG. It is a longitudinal cross-sectional view of the piston rod tip part which shows another Example. 1 ... Cylinder, 2 ... Piston, 3 ... Piston rod, 7
... through holes, 9 ... partition walls, 10 ... gas sealing plugs.

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. A piston is slidably accommodated in a cylinder filled with gas, and the piston is supported by the tip of a piston rod slidably inserted in the cylinder in the axial direction. In a stay damper for a swing door that locks one of the base ends with a swing door and the other with a surrounding frame body to assist opening and closing of the swing door, a through hole that vertically penetrates the piston rod to communicate the inside and outside of the cylinder is formed. In addition, a blocking part is provided at the tip of the piston rod to block this through hole, and a protrusion that breaks this blocking part when the piston enters the deepest part of the cylinder and opens the through hole inside the cylinder is placed opposite to the blocking part. A stay damper for a swing door, which is provided at the bottom of the cylinder.