JPS5920896B2 - gas spring - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas spring whose length can be adjusted steplessly.

Most of the locking mechanisms for reclining seats in automobiles and the like currently use mechanical locks, but since mechanical locks can only be adjusted in stages and fall over due to impact, they can be adjusted steplessly and have a fixed position when the lock is released. Gas springs are attracting attention because they can control the speed of the seat so that it reclines at speed.

By the way, in a gas spring, a piston is slidably inserted into a gas spring body filled with gas, a piston rod attached to the piston is extended outside the gas spring body, and a piston is attached to the piston, which is defined by the piston. An orifice is provided to communicate the gas chambers within the gas spring body.

Some types have a piston equipped with a valve mechanism for opening and closing an orifice, and a valve rod for operating the valve mechanism inserted on the piston rod side.

This gas spring uses the difference in pressure receiving area of the gas pressure acting on the piston.

The piston rod is biased in the direction of protrusion from the gas spring body, and by operating the valve stem from the outside to close the valve mechanism (orifice close), the piston rod protrudes from the gas spring body by the desired amount. By opening the valve mechanism (orifice open) while locking the valve.

This allows the piston rod to freely extend relative to the gas spring body.

But this kind. Gas springs that do not have a free piston cannot be locked as a rigid body, but have a slight spring action.

When used to adjust the angle of the backrest of a reclining seat in a vehicle, etc., the lever ratio is large, so when force is applied to the backrest during braking or acceleration, there is a problem that the backrest escapes due to the spring action.

In addition, in the gas spring without the above-mentioned free piston, the free piston is slidably fitted in the gas spring body on the opposite side to the piston rod side with the piston as a reference. Define the inside of the main body.

There is one in which the piston and piston rod side of the free piston is used as an oil chamber in which oil is sealed, and the side of the free piston where the piston and piston rod are not present is used as a gas chamber in which gas at a predetermined pressure is filled.

This type of gas spring with a free piston is good for tensile loads, but it is not suitable for reclining seats in vehicles.

When an abnormally large force acts as a compressive load, such as during a rear-end collision, the gas spring compresses the gas chamber and breaks.

For this reason, it is necessary to increase the piston diameter or increase the gas pressure.

Increasing the piston diameter causes problems in terms of installation space and cost, while increasing the gas pressure increases the reaction force when the gas spring opens the valve, and there is a limit to the work that can be done with each piece of equipment. was there.

In other words, although gas springs have various advantages over mechanical locks, their locking as a rigid body is incomplete, and the seat cannot hold a person firmly in place in the event of a collision or rear-end collision. Because there was no such thing, there were still problems in practical use.

It is an object of the present invention to provide a gas spring that solves the above-mentioned problems. capable of being inserted and containing an oil liquid;
A sealed container is housed inside the other end of the cylinder, and a free piston is slidably inserted into the sealed container, so that a gas chamber filled with gas and an oil liquid are formed in the sealed container by the free piston. An oil passage is defined in the oil chamber to be accommodated, and an oil passage is provided which communicates the oil chamber of the sealed container with one end side of the cylinder, and a valve for opening and closing the oil passage is provided in the middle of the oil passage, This is the configuration.

An embodiment of a gas spring according to the present invention will be described below with reference to the drawings.

In the figure, a piston-equipped rod 2 is slidably inserted into a front guide 1a that closes one end of a sealed cylinder 1.

An airtight container 3 is housed inside the cylinder 1 on the side opposite to the insertion side of the rod 2, and is made up of a lid 1b and an inner lid 1c that close the other end of the cylinder 1. This holds the closed container 3 in place.

The space inside the cylinder 1 is filled with oil A.

Sealed. The space inside the container 3 is divided into an oil chamber and a gas chamber by the free piston 4, and the oil chamber contains an oil liquid B, and the gas chamber contains a gas G.

This sealing is performed at the gas filling stopper 3a before the closed container 3 is assembled into the cylinder 1.

Sealed container - Oil B in the container 3 and oil A in the cylinder 1 are communicated through a passage 5 as an oil path.

The passage 5 includes a narrow annular space 5a formed between the outer peripheral surface of the sealed container 3 and the inner peripheral surface of the cylinder 1, and a passage 5b provided in the lid 1b that communicates the annular space 5a with the inside of the sealed container 3. , passages 5c and 5b which communicate the annular space 5a with the space in front of the piston of the cylinder 1.

A valve 6 is provided at an appropriate location in the passage 5, and the passage 5 is opened and closed by a valve rod 7 being moved in and out of the closed container 3.

That is, the valve stem 7 is provided with a reduced diameter part 7a, and the reduced diameter part 7a enters the oil liquid B side and is placed at the position of the seal packing 7b, thereby connecting the first passage 5b and the oil liquid B in the closed container 3. The valve 6 is opened when conduction is established between the passage 5b and the oil B, the reduced diameter part 7a is pushed out to the side opposite to the oil B, the large diameter part 7c is fitted into the seal packing 7b, and the passage 5b is connected to the oil B. The valve 6 is closed when the conduction is cut off.

7d is a seal gasket provided in the penetrating portion of the valve stem 7;
Reference character e is a spacer that determines the axial distance between the seal packings 7b and 7d.

A mounting portion 8 for a gas spring is formed at one end of the lid 1b, and the mounting portion 8 receives the load applied from the rod 2.

For example, when used as a reclining seat, the mounting portion 8 is fixed to the seat, and the load 2 is directly or indirectly connected to the backrest.

Further, a valve rod 7 that operates the opening and closing of the valve 6 is connected to a lever device.

A piston 9 is attached to the end of the rod 2 connected to the backrest on the insertion side into the cylinder 1 to guide the movement of the rod 2 into and out, and to provide a buffering force through a small hole 10 formed in the piston 9. It has become.

The action of the gas spring having the above configuration will be explained by taking as an example the case where the gas spring is attached to a reclining seat.

First, to adjust the back support angle, open the valve 6 by pushing the valve stem 7 into the gas spring, and then open the valve 6.
The oil 3 inside the cylinder 1 communicates with the oil A inside the cylinder 1.

At this time, the pressure of the gas G in the sealed container 3 is transferred to the oil liquid B via the free piston 4.

A and acts as a force to push the rod 2 out of the cylinder 1, but when an external force greater than this force acts on the rod 2 from the back rest, the rod 2 is pushed into the gas spring.

in this case. The volume of the inserted rod 2 is absorbed by reducing the volume of the gas G since oil is incompressible.

Moreover, when the valve 6 is opened and no external force acts on the rod 2, the rod 2 protrudes outside the cylinder 1 due to the pressure of the gas G.

By setting the backrest at an arbitrary position, removing the lever, and applying force to push the valve 6, the rod 7 is pushed out by the pressure of the gas G, and the valve 6 is closed.

As a result, the oil liquid and air are separated within the gas spring, so that the load applied to the rod 2 is locked by the oil column, that is, as a rigid body.

but. In this state, the external force applied to the rod 2 is
Therefore, even if the vehicle collides or rear-ends and an abnormally large force is applied to the reclining seat, the rigid body is completely locked because the oil is incompressible.

The reclining seat holds one person firmly without having to work.

The angle of the backrest is not only adjusted steplessly, but also the speed at which the gas spring expands and contracts can be adjusted by appropriately selecting the degree of opening of the passage 5 or the small hole 10.

Since the present invention has the configuration and operation described above, it has the following various advantages.

(i') Air is sealed in an airtight container housed in the cylinder, and the communication with the oil in the cylinder can be opened and closed by a valve, so that in the locked state, external force applied to the rod is not transmitted to the gas. It is possible to obtain a rigid body lock using a highly reliable oil column.

(D) Since another airtight container is provided in the cylinder in a cartridge type manner, the airtight container can be manufactured independently from the assembly of the cylinder and rod, and therefore filling the airtight container with gas and assembling the airtight container as a whole is easy. It becomes extremely easy.

(c) The speed of adjusting the length of the gas spring can be increased by appropriately defining the oil passage that communicates the oil part in the cylinder with the oil part in the sealed container and the small hole formed in the piston of the rod with piston. It can be determined appropriately.

B) Since the valve of the passage can be opened and closed regardless of the degree to which the rod with piston protrudes and retracts into the gas spring, the length of the gas spring can be adjusted steplessly.

(E) Since the gas pressure can be selected regardless of the lock load,
Gas pressure can be selected low.

(f) Since the valve device and the air sealing section can be incorporated into the sealed container of the unit, manufacturing convenience can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a gas spring according to the present invention. The meanings of the symbols in the diagram are as follows. 1... cylinder, 2... rod,
3a... Gas filling stopper, 3... Airtight container, 4... Free piston, 5... Passage, 6... Valve, 7・・・・・・Valve stick.

Claims (1)

[Claims] 1. A rod with a piston is slidably inserted into one end of the cylinder, and an oil is contained therein. A sealed container is stored inside the other end of the cylinder. A free piston is slidably inserted into the sealed container,
The airtight container is defined by the free piston into a gas chamber filled with gas and an oil chamber filled with oil. An oil passage communicating between the oil chamber of the sealed container and the inside of one end of the cylinder is provided. A valve is provided in the middle of the oil passage to open and close the oil passage. A gas spring characterized by: