JPS6260570B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a stay damper that is mainly used to hold a vertically opening/closing door in the rear part of an automobile or the like open/closed.

The stay damper has a repulsive force due to the gas pressure sealed inside, but the gas pressure may decrease due to gas leakage or a decrease in outside temperature.
When the gas pressure falls below a predetermined value, the reaction force of the piston rod decreases, making it impossible to hold the door and causing the door to fall.

This invention was made to solve the above problems, and uses the action of an oil lock to prevent the door from falling due to a drop in internal gas pressure by rotating the piston rod or outer cylinder when the door is fully open. The purpose is to provide a stay damper that can reliably prevent this.

Embodiments of the present invention will be described below based on the drawings.

First, to explain the structure, as shown in FIG. 1, a bearing 9 is housed in the upper end of the cylinder 7 in which the piston rod 1 is concentrically housed, and a sealing material 8 is installed in the axially adjacent area of the cylinder 7. It is housed in sliding contact with the outer periphery of the Further, a disk-shaped extension stopper 6 having slits or serrations 6a radially provided on the lower surface side is concentrically connected to a position immediately below the stopper.

Next, in the threaded portion 1a of the middle shaft of the piston rod 1, slits or serrations 2a of the same shape that engage with the slits or serrations 6a of the extension stopper 6 are provided radially on the upper surface of the disc body, and A valve stopper 2 having a convex surface 2b on the lower side near the outer periphery is screwed into the valve stopper 2 so as to be helically movable.

In this case, the slits or serrations 2a of the valve stopper 2 shown in separate drawings in FIGS. 2 and 3 are either slits E with an alternating arrangement of concavities and convexities shown in FIG. It has become a serration F. Naturally, therefore, a slit E or serration F of the same shape is also provided on the side of the extension stopper 6 of the other with which either of them engages.

A piston 3 is fastened to the stepped end portion of the piston rod 1 via a piston nut 11. The passage 3 is crimped onto the seat surface of the piston 3 on the valve stopper 2 side via the return spring 5.
A check valve 4 for closing a is provided. This check valve 4
is provided with an orifice 4a, and when the piston rod 1 operates on the extension side, oil from the upper oil chamber A flows through the orifice 4a to the lower oil chamber B while applying throttling resistance, and conversely, when the piston rod 1 operates on the pressure side, the oil from the upper oil chamber A flows through the orifice 4a. The check valve 4 opens and the flow moves from the lower oil chamber B to the upper oil chamber A without resistance.
Drain the oil. When the valve stoppers 2 move along the piston rod 1, their convex surfaces 2b are mutually positioned so that they can restrain the check valve 4 in the closed state and at the same time close the orifice 4a.

Next, the action will be explained.

In normal use, check valve 4 is operated by valve stopper 2.
It is pressed against the piston 3 by the return spring 5 without coming into contact with the piston 3. Therefore, when operating on the rebound side, the upper and lower oil chambers A and B of the piston 3 are communicated by the orifice 4a provided in the check valve 4, and when operating on the compression side, the return spring 5 is bent and the check valve 4 opens. The upper and lower oil chambers A and B of the piston 3 communicate widely, and the stay damper operates smoothly.

When the door is fully opened from the above-mentioned normal state, that is, when the stay damper is in the fully extended state, the valve stopper 2, which is threadedly engaged with the piston rod 1, is inserted into the extension stopper 6 on the cylinder 7 side with both slits or They engage through serrations 2a and 6a.

Therefore, if either the piston rod 1 or the cylinder 7 is rotated in a predetermined direction at this point, the valve stopper 2 will move the piston 3 on the piston rod 1.
It moves to the side and eventually comes into pressure contact with the check valve 4 with the convex surface 2b. In this state, the check valve 4 is restricted and the orifice 4a is blocked, cutting off communication between the upper and lower oil chambers A and B of the piston 3, so that the stay damper is completely locked in terms of pressure.
Hold the piston rod 1 in that position.

To release the locked state, rotate either the piston rod 1 or the cylinder 7 in the opposite direction, and the valve stopper 2 will close the check valve 4.
Since the upper and lower oil chambers A and B of the piston 3 communicate with each other through the orifice 4a, the check valve 4
is opened and the stay damper can freely operate to the pressure side.

In the above embodiment, if responsiveness is not particularly required, the return spring 5 of the check valve 4 may not be provided. That is, when the piston 3 is actuated, the check valve 4 is automatically pressed against the seat surface of the piston 3 due to the flow of oil, and the check valve 4 is automatically pressed against the seat surface of the piston 3, so that the check valve 4 performs a predetermined action under almost the same condition as when it receives the support of the return spring 5. can do.

As explained above, this invention mechanically locks and releases the check valve by rotating the valve stopper, so it is possible to reliably lock and release the oil lock, and the number of individual parts is reduced. Since it is basically the same as a conventional stainless steel damper, it has the advantage of being easy to manufacture at low cost.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view of the main part of a stay damper according to an embodiment of the present invention, FIG. 2 is a partial front view showing a valve stopper, FIG. 3 is a vertical sectional view thereof, and FIG. Enlarged view of the slit in the section,
FIG. 5 is an enlarged view of the serration. 1... Piston rod, 1a, 1b... Threaded portion, 2... Valve stopper, 2b... Convex surface, 2
a, 6a...slit or serration, 3...
... Piston, 4 ... Check valve, 4a ... Orifice, 5 ... Return spring, 6 ... Extension stopper, 7 ... Cylinder, E ... Slit, F
...Serration.

Claims (1)

[Claims] 1 In a stay damper that urges the piston in the direction of extension of the piston rod by the pressure of gas sealed in the cylinder, a check valve with an orifice that opens and closes communication between the upper and lower oil chambers is disposed on the piston, and the piston rod is A stay damper characterized in that a valve stopper is screwed into a position facing a check valve so as to be movable in the axial direction, and a member that can engage with the valve stopper is attached to the cylinder.