JPS6230590Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is an open stay used for opening and closing the rear door or trunk of a car, for example.
In particular, it relates to an open stay for preventing clogging of square holes that generate damping force.

This type of open stay, as shown in Figure 1,
The bottom part 1a of the damper case 1 is attached to the vehicle body side, and the end of the piston rod 3 connected to the piston 2 sliding inside the damper case is attached to the door side. Gas is filled in the damper case 1, and the door or trunk is closed. When closed, it is compressed as shown in a, and conversely, when the door or trunk is fully opened as shown in c, it is expanded and fixed, and when it is extended, a damping force is applied. In addition, an appropriate amount of oil 4 is sealed in the damper case 1 to serve as lubricating oil in addition to gas leakage prevention and damping functions. Further, b indicates an intermediate operating state.

However, as shown in Fig. 2, the conventional piston has two pistons 2a and 2b, front and rear, provided at the tip of a piston rod 3 with an appropriate space between them, and a seal ring 2c movably inserted into the space.
is slidably fitted into the damper case 1, and during compression, the seal ring 2c contacts the rear piston 2b and closes the gap between the rear piston 2b and the damper case 1, so that most of the gas and oil are released as shown by the arrow. Then, it passes through the gap between the front piston 2a and the damper case 1 and flows into the passage 5 of the rear piston 2b.
In this case, almost no fluid flows into the square hole 6 provided in the front piston 2a. On the other hand, when it is extended, the seal ring 2c comes into contact with the front piston 2a as shown in FIG. 5 and the damper case 1 flows into the square hole 6 provided in the front piston 2a to generate a damping force. For this reason, when installing the open stay, the position of the square hole 6 changes the way the oil flows and the damping force also changes. Moreover, there is also the disadvantage that the square hole 6 becomes clogged with debris and the open stay becomes locked. As an example, the square hole 6 has a diameter of about 0.4 mm.

The present invention eliminates these conventional drawbacks, and one embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 4 is a sectional view of essential parts showing an embodiment of the open stay of the present invention. As shown in the figure, two front and rear pistons 2a and 2b are provided at the tip of the piston rod 3 with an appropriate space, and a seal ring 2c is movably inserted into the space and is slidable inside the damper case 1. A square hole 7 is provided in the axial direction from the center of the end surface of the piston rod 3. One of the square holes 7 is connected to the pistons 2a and 2b through a diametrical passage 8 provided in the piston rod 3 and, as shown in FIG. It is connected to the space provided in the. However, the size of this slit 9 is set smaller than the size of the square hole 7.

In this way, when the piston rod 3 is extended, the gap between the front piston 2a and the damper case 1 is closed by the seal ring 2c, so that gas and oil can flow through the passage 5 of the rear piston 2b as shown by the arrow. It enters the space between both pistons 2a and 2b through the gap with the damper case 1, and then passes through the radial slit 9 provided in the front piston 2a, the through hole 8 provided in the piston rod 3, and then through the square hole 7 into the damper case 1. It flows out to the bottom of the tank.
At this time, if there is any dirt mixed with the oil, it will first clog a part of the slit 9, but it will not clog the entire slit 9 and will not enter the square hole 7. On the other hand, during compression, gas and oil do not pass through the square hole 7 but flow out from the passage 5 of the rear piston 2b through the gap between the front piston 2a and the damper case 1, as in the conventional case. Note that the slit 9 was provided on the inner end surface of the front piston 2a, but the slit 9 was provided on the inner end surface of the front piston 2a.
The same effect can be achieved even if it is provided on the inner end surface of the. Furthermore, since the square hole 7 is located at the center of the piston rod, the piston has no directionality, and therefore the damping force does not vary depending on the mounting position of the piston.

Although the slit 9 is provided in this embodiment, there is no difference in effectiveness even if a ring-shaped filter is provided.

As explained in detail above, according to the present invention, in addition to preventing clogging of the square hole, the damping force does not change depending on the direction of rotation of the piston, so a stable open stay can always be obtained. be.

[Brief explanation of the drawing]

Figure 1 is a diagram showing how the open stay is used.
Figures 2 and 3 are explanatory diagrams of the operation of the piston in a conventional open stay, Figure 4 is a sectional view of a main part showing an embodiment of the open stay of the present invention, and Figure 5 is a side view of the front piston. . 1... Damper case, 2a... Front piston, 2b... Rear piston, 2c... Seal ring, 3... Piston rod, 5... Passage, 7...
Square hole, 8...passage, 9...slit.

Claims (1)

[Scope of utility model registration request] Two front and rear pistons are installed at the tip of the piston rod with an appropriate space between them, and a seal ring is movably inserted between them and is slidably fitted into the damper case.When the piston rod is expanded or compressed, the oil ring moves between the front and rear pistons. In an open stay that generates damping force by closing the gap between one side of the piston rod and the damper case, a square hole is provided in the axial direction from the center of the end face of the piston rod, and the square hole is connected to a diametrical passage provided in the piston rod. Provided on the inner end surface of one of the front and rear pistons and connected to the space between the two pistons through a number of radial slits smaller than the square hole, and allowing gas and oil to flow into the square hole through the slits during compression. An open stay characterized by generating damping force.