JPH0243928B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in shock absorbers for automobiles, door checkers, and other shock absorbers that use oil to cushion shocks.

Specifically speaking, in the case of a door checker, a shock absorber using oil has a piston inside a cylinder 1 sealed with oil and attached to a door or building frame, as shown in Figures 1 and 2. A rod 3 is slidably fitted into the piston 2 and has an outer end connected to a building frame or a door.
The inner ends of the rod 3 are connected to each other, and the outer end of the rod 3 is slidably protruded from one end of the cylinder 1 to the outside. A spring 4 is installed in one of the first chamber 1a and the second chamber 1b, which are divided into the front and rear in the direction, to urge the rod 3 connecting the piston 2 thereto. In addition, the piston 2 has a first port 5 for rapidly passing the oil from the first chamber 1a side to the second chamber 1b side, and a first port 5 for allowing the oil from the second chamber 1b side to slowly flow to the first chamber 1b side. A second port 6 is provided for the flow to flow to the side 1a, and the first port 5 is provided with a second chamber 1.
A check valve 50 is provided to prevent oil from flowing from the b side to the first chamber 1a side.
As shown by the double line arrow in the figure, when the cylinder 1 is pushed in so as to narrow the first chamber 1a in the cylinder 1 against the bias of the spring 4, the first port 5 and the second
Oil rapidly flows from both port 6 and the second chamber 1b.
When the piston 2 moves toward the return side as shown by the double line arrow in FIG. 2 due to the bias of the spring 4, the oil in the second chamber 1b is 1st chamber 1a gently from 2 port 6 only
The piston 2 is configured to flow toward the side, thereby slowing down the movement of the piston 2 on the return stroke side.

In the oil-using shock absorber A configured in this way, the diameter of the second port 6 remains unchanged.
The speed of the return stroke of the piston 2 should always be constant, but in reality, its characteristics are not constant;
It fluctuates with temperature changes. This is because the temperature of the oil sealed in cylinder 1 changes due to changes in air temperature, which changes the viscosity of the oil and changes the resistance when it flows through the port. . For this reason, conventional oil-based shock absorbers have a problem in that the comfort of the equipment to which they are attached changes due to changes in characteristics due to temperature changes.

By the way, in this type of oil-using shock absorber, the means for changing the diameter of the second port in response to external temperature changes was developed in U.S. Pat.
This has been known for a long time as disclosed in Japanese Patent No. 167346. However, in this method, a rod connected to a piston that is slidably fitted into a cylinder is formed into a cylindrical shape, and an inner cylindrical actuating rod made of a material with a large coefficient of thermal expansion is installed in the inner cavity of the rod. One axial end of the rod is fixed to the rod, and the other end is connected via a spring to an on-off valve that faces an orifice provided at the inner end of the rod. An operating rod fitted inside the rod expands and contracts in response to temperature changes, moving the on-off valve facing the orifice and changing the opening degree of the orifice. Since the expansion/contraction operation caused by changes in temperature is greatly affected by external temperature changes, the diameter of the orifice, which is the second port, is expanded or contracted regardless of changes in the temperature of the oil in the cylinder. It does not correct changes in properties due to changes in viscosity caused by temperature changes.

The present invention was made in order to solve these problems occurring in conventional means, and it accurately detects the temperature change of the oil when the temperature of the oil inside the cylinder fluctuates. It is an object of the present invention to provide an oil-using shock absorbing device that expands and contracts the diameter of a second port accordingly and operates while always maintaining constant characteristics.

In order to achieve this object, the oil-using shock absorber according to the present invention has a rod that is attached to the inner end of a rod whose outer end protrudes freely in and out from one end of the cylinder, which is sealed with oil. A piston to be connected is fitted so as to be slidable in the axial direction of the cylinder, and the piston is fitted with a first chamber and a second chamber of the cylinder which are partitioned in the front and rear in the axial direction by the piston. A first port for causing the oil in the first chamber to rapidly flow to the second chamber side and a second port for causing the oil in the second chamber to slowly flow to the first chamber side, and on the wall of the piston,
A cage-shaped bracket is attached to a portion facing the second port, and a needle valve is assembled and supported on this bracket so as to be movable forward and backward with respect to the second port, and a direction in which the needle valve is pulled away from the second port. This invention provides an oil-using shock absorbing device characterized in that a spring that biases the needle valve and a thermomechanism that pushes the needle valve toward the second port by increasing temperature are assembled and supported.

Next, an example of implementation will be described in detail with reference to the drawings. In addition,
The same reference numerals in the drawings shall be used for the same constituent members.

In FIG. 3, 1 is a cylinder sealed with oil, 2 is a piston fitted slidably into the cylinder 1, and 3 is integrally or integrally connected to the piston 2 at its inner end, and the intermediate portion is connected to the cylinder 1. One end wall 1
A rod 4 is slidably fitted into a through hole 11 provided at 0 and has an outer end protruding outside the cylinder 1, and 4 is inserted into the cylinder 1 so as to push the piston 2 toward the outer end of the rod 3. A first chamber 1 of a first chamber 1a and a second chamber 1b partitioned by the piston 2 of the cavity.
A spring is installed on the a side, 5 is a first port with a check valve 50 provided on the piston 2, and 6 is a second port provided on the piston 2. The piston 2 is configured in the same manner, and when the rod 3 is pushed into the cylinder 1 and the piston 2 narrows the first chamber 1a in the cylinder 1 against the bias of the spring 4. teeth,
The oil in the first chamber 1a side rapidly flows to the second chamber 1b side via the first port 5 and the second port 6, and the pushing force of the rod 3 becomes weaker or is released, and the piston 2 moves against the spring 4. When the first chamber 1a returns to the direction of expansion due to bias, the oil in the second chamber 1b flows gently into the first chamber 1a from only the second port 6, thereby preventing the movement of the piston 2 from loosening. I'm starting to do that.

a is a needle valve mounted on the piston 2 described above so as to be able to move forward and backward toward the second port 6 provided in the piston 2;
A thermomechanism c made of a wax thermoelement is assembled and supported on a basket-shaped bracket b attached to the wall surface 2a on the side of the chamber 1a, and a guide cylinder portion 70 of the thermomechanism c made of the wax thermoelement is mounted.
A guide shaft portion 80 at the base end of the needle valve a is slidably fitted, and the needle valve a is placed between the wall surface 2a of the piston 2 and a spring receiver 81 provided in the shape of a brim. Spring d that pushes back in the direction of pulling away from
As a result, when the temperature of the oil in the cylinder 1 rises and the pressure of wax in the temperature sensing part 71 of the thermomechanism c increases and the piston in the guide cylinder part 70 is pushed out, the needle The needle-like part at the tip of the valve a plunges into the second port 6 and operates to narrow the cross-sectional area of the second port 6, and the temperature of the oil in the cylinder 1 decreases, causing the temperature in the temperature sensing part 71 to decrease. When the pressure of the waxes decreases, the tip of the needle valve a is pulled out from the second port 6 by the pressure of the spring d, and operates to expand the cross-sectional area of the second port 6. The operation of the needle valve a due to the temperature change of the oil in the cylinder 1 is adapted to the viscosity characteristics of the oil sealed in the cylinder 1, and the cross-sectional area of the second port is automatically changed due to the temperature change. The flow rate of the oil flowing through the second port 6 is adjusted to be constant.

Next, FIG. 4 shows another embodiment. In this embodiment, the guide shaft portion 80 at the proximal end of the needle valve a is connected to the wall surface of the piston 2 on the first chamber 1a side.
The thermomechanism c is supported directly and slidably on a bracket b attached to the needle valve a, and the thermomechanism c has a plurality of drum-shaped bimetals 75 assembled in parallel and mounted between the bracket b and the base end of the needle valve a. The thermomechanism c consisting of this bimetal 75...
A spring d stretched between a spring receiver 81 provided on the needle valve a and the wall surface 2a of the piston 2 allows the needle valve a to expand or contract the cross-sectional area of the second port 6 in response to temperature changes.

The embodiment device constructed in this manner operates as follows.

Piston 2 slidably fitted into cylinder 1
However, when the rod 3 is pushed in, the first chamber 1a is moved to the side that narrows, and from this state, when the push of the rod 3 becomes weaker or released, the spring 4
When the piston 2 moves to the return side due to the bias of
The fluid flows into the first chamber 1a only from the port 6, making the movement of the piston 2 gradual.

At this time, the oil flowing into the first chamber 1a is caused by a cage-shaped bracket on the wall surface 2a of the piston 2 facing the first chamber 1a, at a portion of the piston 2 where the second port 6 is provided. b is assembled, and the needle valve a is connected to the thermomechanism c and the spring d.
Since it is assembled and supported in a controlled state by As the oil temperature increases, the needle valve a performs control operations appropriately in accordance with the oil temperature.

Needle valve a provided facing the second port 6
The diameter of the second port 6 is always expanded or contracted according to the temperature of the oil flowing through the second port 6, and the viscosity changes due to changes in the temperature of the oil sealed in the cylinder 1. The flow resistance when flowing through the second port 6 is appropriately corrected.

As explained above, the oil-using shock absorber according to the present invention has a piston 2 which is slidably fitted into a cylinder 1 filled with oil, and which compresses the first chamber 1a by pushing the rod 3 connected to the piston 2. When returning from the state where it moved to the side where the second chamber 1b can be squeezed,
A second port 6 is provided in the piston 2 to make the operation gentle, and the piston 2
A cage-like bracket b is provided at a portion of the wall surface 2a facing the second port 6, and a needle valve is controlled by a thermomechanism c to expand or contract the diameter of the second port 6 according to the temperature of the oil. Since the needle valve a is assembled and supported, the oil that flows from the second chamber 1b side into the first chamber 1a through the second port 6 when the piston 2 returns moves through the needle valve a. Thermomechanism c that operates according to temperature
The liquid always flows around the area and flows into the first chamber 1a. From this, the needle valve a provided facing the second port 6 always adjusts the temperature of the oil flowing through the second port 6 to the second port 6.
The diameter of the port 6 is now controlled to expand or contract, and the flow resistance when flowing through the second port 6 due to fluctuations in viscosity due to temperature changes in the oil sealed in the cylinder 1 can be accurately corrected. become.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view of a conventional oil-using shock absorber, FIG. 2 is an explanatory view of the same action as above, FIG. 3 is a partially omitted longitudinal sectional side view of an oil-using shock absorber according to the present invention, and FIG. The figure is a longitudinal sectional side view of the main parts of another embodiment of the device. Explanation of drawing symbols, A...Shocking device, a...Needle valve, b...Bracket, c...Thermo mechanism, d...Spring, 1...Cylinder, 1a...First chamber, 1b...Second
Chamber, 10... End wall, 11... Through hole, 2... Piston, 2
a... Wall surface, 3... Rod, 4... Spring, 5... First port, 50... Check valve, 6... Second port, 70... Guide cylinder part, 71... Temperature sensing part, 75... Bimetal, 80
...Guide shaft part, 81...Spring receiver.

Claims (1)

[Claims] 1 A piston 2 connected to the inner end of a rod 3 whose outer end protrudes from one end of the cylinder 1 so as to be freely removable and removable in a cylinder 1 that is sealed with oil.
is slidably fitted in the axial direction of the cylinder 1,
The piston 2 rapidly transfers the oil in the first chamber 1a of the first chamber 1a and second chamber 1b in the cylinder 1, which are divided into the front and rear in the axial direction, to the second chamber 1b side. the first port 5 for allowing oil to flow through the second chamber 1b, and the oil in the second chamber 1b to slowly flow into the first chamber 1
A second port 6 is provided on the side a, and a cage-shaped bracket b is attached to a portion of the wall surface 2a of the piston 2 facing the second port 6. , the needle valve a is attached to and supported by the second port 6 so as to be able to move forward and backward, and the needle valve a is moved to the second port by a spring d which biases the needle valve a in the direction of separating it from the second port 6 and by increasing temperature. A shock absorbing device using oil, characterized in that a thermo mechanism (c) for pushing out toward a port (6) is assembled and supported.