JPS5818541B2 - Lock-down oil damper - Google Patents

Description

[Detailed Description of the Invention] For example, an oil damper for a door closer used in an automobile or a room entrance requires a locking function to keep the door in any open state and a spring characteristic to automatically close the door. It may be done.

Such oil dampers can obtain spring characteristics by sealing in gas, but the pressure needs to be considerably high, and negative pressure is generated on one side of the piston when the door is opened, so the orifice of the piston The problem is that the flow of oil through the pipe becomes extremely high, causing abnormal noise.

The present invention keeps the pressure difference between both sides of the piston relatively small by constantly applying the pressure of the sealed gas to both sides of the piston to prevent the generation of negative pressure even when the door is opened.
This eliminates the drawback of generating abnormal noise as described above.

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, showing a state in which the damper is fully extended and the door is closed.

The piston 2 attached to the tip of the hollow piston rod 1 is slidably fitted into the cylinder 3, and the rod 1 is passed through the front guide 4 and oil seal 5 attached to the tip of the cylinder. .

The cylinder 3 and the tip of the piston rod are filled with oil 6, and the base end of the rod is filled with high-pressure gas 7.
They are separated by a free piston 9 fitted with a 1J ring 8.

The piston 2 also has two oil holes 11 and 12 that fit the O-link 10 and communicate the base end of the cylinder 30 with the hollow part of the piston rod 1, and the two oil holes 11 and 12 that connect the base end of the cylinder and the distal end thereof. Provide two oil holes 13 and 14 that communicate,
A check valve 15 made of a steel ball or the like is provided in the oil hole 11 to allow oil to flow from the hollow part of the rod 1 toward the base end of the cylinder 3, and is pressed by a weak spring 16. To,
A similar check valve 17 is provided to allow oil to flow from the base end of the cylinder 30 to the distal end thereof, and is pressed by a weak spring 18.

Note that the oil holes 12 and 14 have flow passages configured to narrow their diameters on the check valves 19, 2 and 1 side.

Furthermore, the oil hole 12 has a poppet-type check valve 19 that allows oil to flow from the base end of the cylinder 30 toward the hollow part of the rod 1.
A similar check valve 21 is provided in the oil hole 14 to allow oil to flow from the distal end of the cylinder 3 toward its proximal end. 1
Bypass oil passages 23 and 24 are formed on the sides of 9 and 21.

Next, an explanation will be given of the operation when the above-mentioned oil damper is used in a door closer.

First, when an attempt is made to open the door, compressive force is applied to the damper, so the oil pressure at the base end of the cylinder 30 increases.

Therefore, when the door is pushed with more than a certain force determined by the force of the spring 20, the check valve 19 opens and oil 6 flows into the hollow part of the piston rod 1 from the oil hole 23, and the check valve 17 opens and the oil 6 flows into the hollow part of the piston rod 1. Oil flows from the hole 13 to the tip side of the cylinder 3.

The pressure-receiving area of the force-dont type check valve 19 increases when the check valve 19 opens, so that the door can then be easily opened with a light force.

That is, since the check valve 19 is in contact with the constricted flow path of the oil hole 13 when closed, the area for receiving oil pressure is extremely small.

When oil acts on this narrow pressure-receiving area and the check valve 19 opens against the spring 20, the oil acts on the entire upper surface of the check valve 19, increasing the oil-receiving area.

Therefore, when the pressure receiving area increases, the door can be opened with a light force as long as the force of the spring 20 is constant.

When this door is released at an arbitrary position, the check valve 17 is closed and the check valve 21 is kept closed by the elasticity of the spring 22, so oil is sealed at the tip side of the cylinder 3 and the damper is locked. Therefore, the door remains open.

Next, if you try to close the door by applying an external force to it,
A stretching force is applied to the damper.

When this force exceeds a certain value determined by the elasticity of the spring 220, the check valve 21 opens.

And by this opening, the poppet type check valve 2 is opened in the same manner as described above.
As the pressure receiving area of 1 increases, the check valve 15 receives high pressure gas I.
The piston rod 1 is opened by the pressure applied to the oil in the piston rod 1.

Therefore, thereafter, the damper automatically expands only by the expansion force of the gas 1, and the oil in the rod 1 and the oil on the distal end side of the cylinder 3 flow into the proximal end side through the oil holes 11 and 24.

When the door is completely closed in this manner and the damper stops expanding, the state shown in FIG. 1 is restored.

FIG. 2 is a curve showing the above-mentioned operation, where the horizontal axis is the displacement distance of the damper, O is the closed state of the door, and 100 is the fully open state.

Moreover, 10F on the vertical axis is the force that compresses the damper, -F is the force in the direction of expansion, and the chain line is the expansion force due to the enclosed high-pressure gas.

In other words, when a certain compression force is applied to the damper, the check valve 19
After the valve opens, compression can be performed with a small force due to the increase in the pressure-receiving area of the valve.

Further, when a certain stretching force is applied to the damper in a compressed state, the valve 21 opens, and since the pressure receiving area of the valve increases, the damper is automatically pushed back by the pressure of the enclosed gas.

In addition, since a damping force is generated by the oil passing through the oil hole 23 or 24, the extension operation is performed at a slow speed.

As described above, in the damper of the present invention, the oil in the rod 1 under the pressure of the high-pressure gas 7 always communicates with the base end side of the cylinder 3 through the oil hole 11 having a check valve, and further has a check valve. It communicates with the tip side of the cylinder via an oil hole 13 having a diameter.

Therefore, by making the two oil holes sufficiently large, even when applying an external force to rapidly compress the damper, the oil on both sides of the piston 20 can maintain approximately the same pressure.
There is no risk of creating a large pressure difference between them.

That is, when compressing the damper, the valve 19 opens, but before opening the valve 13, the valve 13 opens first to prevent a pressure difference from occurring between the base end side of the cylinder 3 and the valve 19.
9 operates at a slow speed to open, and since there is no part that generates negative pressure, it is possible to prevent oil from jetting through the oil hole and generating abnormal noise.

Furthermore, when the damper is extended, when the oil pressure at the tip side of the cylinder 3 increases due to an external force, the valve 21 opens at a slow speed, and at the same time as the valve 21 opens, the valve 15 also opens to supply sufficient oil to the base side of the cylinder 30. Therefore, there is no risk of oil jetting through the oil holes and causing abnormal noise.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, and FIG. 2 is an operating curve of the damper shown in FIG. 1. In the figure, 1 is a hollow piston rod, 2 is a piston, 3 is a cylinder, 6 is oil, 7 is high pressure gas, 9 is a free piston, 11, 12, 13, 14 are oil holes, 15° 17
．． 19 and 21 are check valves, 16, 18 and 20 degrees 22 are springs, and 23 and 24 are bypass oil passages.

Claims (1)

[Claims] 1. A piston attached to the tip of a hollow piston rod is slidably fitted into a cylinder, the hollow parts of the cylinder and the piston rod are filled with oil, and high pressure gas is sealed in the base end of the piston rod, and the hollow piston is An oil hole with a check valve that allows oil to flow from the inside of the rod toward the base end of the cylinder, and a check valve that allows oil to flow from the base end of the cylinder toward its tip. An oil hole, an oil hole that allows oil to flow from the base end side of the cylinder toward the inside of the hollow piston rod, and has a flow passage narrowed to one side, and an area provided on the flow passage side that receives oil pressure by opening the oil hole. A check valve that increases the flow rate, an oil hole that allows oil to flow from the tip side of the cylinder toward the base end side and has a flow passage narrowed to one side, and an oil hole that is provided on the flow passage side and receives oil pressure by opening it. A lockable oil damper characterized in that the piston is formed with a check valve whose area increases.