JPH03233088A - Gas stay - Google Patents

Abstract

PURPOSE:To accomplish sufficient absorption of shock by a method wherein a sealing member provided on one end of a cylinder containing gas and oil is penetrated with a piston rod so that it makes the piston rod capable of reciprocating therethrough, and an oil absorbing material is provided on the inside of the sealing member. CONSTITUTION:A sponge (oil absorbing material) 17 is provided, with a piston rod 9 penetrated therethrough, to the inside of a sealing member 7. The sponge 17 is made of cellular material in open cell structure that is capable of absorbing oil 5. The oil 5 is partially absorbed, making contact with the sponge 17 as the sealing member 7 placed facing downward when a tail gate is placed in closing position. When the tail gate is placed in opening position, the sealing member 7 is placed facing upward, and the oil 5 once absorbed with the sponge 17 is released, being squeezed with the sealing member and is moved through orifices 11 to the side of a base member 12. Thereby shock absorption is sufficiently accomplished for the tail gate.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to gas stays, particularly gas stays that are frequently used as stays for automobile tailgates.

<Prior Art> Examples of conventional gas stays include those shown in FIGS. 3 to 5 (see Japanese Unexamined Patent Publication No. 59-24081). In the figure, ■ is a hatchback type car, which is equipped with a tailgate 2 as a back door.
A gas stay 3 is used for opening and closing operations. This gas stay 3 includes a seal portion 7 at one end of the cylinder 6, which is filled with a gas 4 that generates a compression repulsion force and an oil 5 that acts as both a lubricant and a shock absorber.
The structure is such that a piston rod 9 having a piston portion 8 at its tip is inserted so as to be freely protrusive and retractable. A piston ring 10 that slides on the inner surface of the cylinder 6 is fitted on the outer periphery of the piston portion 8, and an orifice 11 through which the oil 5 passes is formed. A connecting portion 13 provided at the base end 12 of the cylinder 6 is pivotally supported by the rear pillar 14, and a connecting portion 15 provided at the base end of the piston rod 9 is pivotally supported by the tailgate 2.

In this gas stay, when the tailgate 2 is closed, most of the piston rod 9 retracts into the cylinder 6, and the seal portion 7 of the cylinder 6 is directed downward (see FIG. 4). Therefore, the oil 5 will accumulate on the seal portion 7 side of the cylinder 6. In this state,
Since most of the piston rod 9 is retracted into the cylinder 6, the volume occupied by the piston rod 9 in the cylinder 6 increases, and the gas 4 is compressed accordingly.
A compression reaction force acts to move the piston rod 9 outward from the cylinder 6. Therefore, when the tailgate 2 is unlocked in this state, due to the balance between the compression reaction force acting on the piston rod 9 and the weight of the tailgate 2, the tailgate 2 can be opened with a light force, and the tailgate 2 can be fully opened. The state can be maintained. When the tailgate 2 is fully opened, the piston rod 9 is connected to the cylinder 6.
The seal part 7 of the cylinder 6 is in the most advanced state.
is in an upward state (see Figure 5). At this time, the oil 5 that was on the side of the seal part 7 of the cylinder 6 passes through the orifice 11 and moves to the side of the base end 12, so that the impact when the tailgate 2 is fully opened is absorbed to some extent. It is.

In addition, since the compression reaction force acts on the piston rod 9 even when the tailgate 2 is closed, the tailgate 2 can be smoothly closed.

<Problem to be solved by the invention> However, in such a conventional gas stay 3, the impact when the tailgate 2 is fully opened is absorbed by the oil 5.
passes through the orifice 11 of the piston part 8 and seals the seal part 7.
Although it was absorbed to some extent by moving from the side to the base end 12 side, when the tailgate 2 was fully opened, the cylinder 6
Since the seal portion 7 is in an upward position, the oil 5 easily passes through the orifice 11 and moves toward the base end portion 12, making it impossible to perform sufficient shock absorption. Therefore, when the tailgate 2 is fully opened, an impact noise and the tailgate 2 swinging back and forth occur, causing discomfort to the opening/closing operator and the occupants.

The present invention has been made by focusing on such conventional technology, and even if the cylinder is installed in such a way that the seal portion of the cylinder faces upward when the piston rod advances, the impact when the piston rod is fully advanced will be reduced. The aim is to provide a girth stay that can sufficiently absorb

Means for Solving the Problems> In order to achieve the above object, the gas stay according to the present invention is provided with an oil absorbing member that releases oil in response to pressure inside the seal portion of the cylinder.

<Function> Since the seal portion faces downward when the piston rod is retracted, the oil absorbing member provided inside the seal portion comes into contact with the oil and absorbs the oil. When the piston rod is advanced from the cylinder, the seal portion faces upward, but the oil remains in the seal portion while being held by the oil absorbing member. Therefore, this oil absorbing member is crushed between the piston part and the seal part of the piston rod in the most advanced state, and the oil released from the oil absorbing member passes through the orifice, thereby absorbing sufficient shock. That will happen.

<Embodiment> A preferred embodiment of the present invention will be described below with reference to FIGS. 1 and 2. Note that a gas stay, which is not shown but will be described later, is also connected to the tailgate, and parts common to the conventional one are designated by the same reference numerals and redundant explanations will be omitted.

The gas stay 16 according to this embodiment is provided with a sponge (oil absorbing member) 17 having a piston rod 9 penetrated inside the seal portion 7 of the cylinder 6. This sponge 17 is an open-cell foam that can absorb the oil 5, and is further equipped with a coil spring 18 inside.
It always has a constant thickness t under no load.

Therefore, in the closed state of the tailgate (the retracted state of the piston rod 9), since the seal portion 7 faces downward, a portion of the oil 5 comes into contact with the sponge 17 and is absorbed. Next, when the tailgate is opened, the seal part 7 of the cylinder 6 will now be in an upward position, but the oil 5 absorbed by the sponge 17 will be retained in the seal part 7. . Therefore, the oil 5 that is not absorbed by the sponge 17 easily passes through the orifice 11 and moves toward the base end 12 of the cylinder 6, but the oil 5 that has been absorbed by the sponge 17 moves to the farthest part. Piston part 8 of piston rod 9 in the state
The sponge 17 is once crushed between the seal portion 7 and the seal portion 7, and is ejected as if being squeezed out, and then passes through the orifice 11 and moves toward the base end portion 12, so that the sponge 17 receives sufficient impact from the tailgate during that time. Absorption can take place. Then, by closing the tailgate again, the piston rod 9 is retracted and the compressed state of the sponge 17 is released, and the elastic restoring force of the coil spring 18 easily returns the sponge 17 to its original thickness t. The oil 5 can be sufficiently absorbed in preparation for the next opening operation of the tailgate.

<Effects of the Invention> The gas stay according to the present invention has the content as explained above, and even if the seal portion of the cylinder is in an upward position when the piston rod is fully advanced, the oil is absorbed by the oil absorbing member. Since the oil released from the sponge can be kept inside the seal part in this state, sufficient shock absorption can be achieved when the piston rod is fully advanced by passing the oil released from the sponge through the orifice of the piston part.

Furthermore, if a coil spring is provided in the oil absorbing member as in the embodiment, the oil absorbing member can always have a constant thickness when the piston rod is retracted, so it can be used in preparation for the next advance of the piston rod. It can absorb enough oil.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing a piston rod retracted state of a gas stay according to an embodiment of the present invention, Fig. 2 is a cross-sectional view corresponding to Fig. 1 showing a piston rod extended state, and Fig. 3 is a sectional view of a conventional gas stay. FIG. 4 is a sectional view showing the piston rod of a conventional gas stay in a retracted state, and FIG. 5 is a sectional view corresponding to FIG. 4 showing the piston rod in an extended state. 4 - Gas 5 - Oil 6 - Cylinder 7 - Seal part 8 - Piston part 9 - Piston rod 11 °° Orifice 16 ' Gas stay 17 "° Sponge (oil absorbing member) 18 -
coil spring method

Claims (2)

[Claims] (1) A piston rod having a piston portion with an orifice at its tip is inserted into a cylinder filled with gas and oil so as to be freely retractable and retractable through a seal provided at one end of the cylinder, and the piston rod In a gas stay that is installed in such a way that the seal part of the cylinder faces upward when advancing and the seal part faces downward when retracting, an oil absorbing member is provided inside the seal part of the cylinder to release oil in response to pressure. A gas stay that is characterized by one thing. (2) The gas stay according to claim 1, further comprising a coil spring in the oil absorbing member.