JPH073068Y2 - Stay damper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a stay damper having a labyrinth groove in a piston portion in a cylinder.

[Prior Art] Generally, as shown in FIG. 4, a stay damper called a gas damper has a piston portion 3 connected to the tip of a piston rod 2 inserted into the cylinder 1 and connected to the cylinder 1 by the piston portion 3.
The expansion side chamber A and the compression side chamber B, which are partitioned and formed inside, are filled with high-pressure gas.

Further, for the piston portion 3, as shown in FIG.
The piston body 30, a stopper 31 adjacent to one end surface (left side in the figure) of the piston body 30, and the piston body
Washer 32 adjacent to the other end surface (right side in the figure) of 30,
And the stopper 31, the piston body 30, and the washer 32 are sequentially inserted in the spigot portion 2a of the piston rod 2, and fixed by the piston nut 33 screwed to the threaded portion 2b of the piston rod 2. Has been done.

A piston ring 34 whose outer circumference is in sliding contact with the inner circumference of the cylinder 1 is provided on the outer circumference of the piston body 30.

The piston body 30 has a port 30a formed by opening a thick portion thereof in the axial direction, and both ends of the port 30a are labyrinth grooves formed on both end surfaces of the piston body 30, respectively. It is said that openings will be made in 30b and 30c.

That is, the expansion side chamber A and the compression side chamber B in the cylinder 1 are communicated with each other through the port 30a and the labyrinth grooves 30b and 30c.

By the way, the labyrinth grooves 30b, 30c are formed so as to control the flow rate of the gas or oil by the flow path resistance when the gas or oil passes through the labyrinth grooves 30b, 30c. Is formed in a meandering shape as shown in FIG.

On the other hand, the piston ring 34 is provided on the outer periphery of the piston body 30 so as to be movable in the axial direction of the piston body 30 (left-right direction in FIG. 5).

Therefore, during the expansion side stroke in which the piston portion 3 comes out of the cylinder 1, the piston ring 34 is positioned toward the right side in the drawing as shown in FIG. Notch 31a of stopper 31 and labyrinth groove 30
b, through the port 30a and the labyrinth groove 30c, the gas is discharged into the pressure side chamber B, so that the stay damper can be stretched relatively slowly.

On the other hand, during the compression side stroke in which the piston part 3 is retracted into the cylinder 1, the piston ring 34 moves toward the left side in the figure, and accordingly, the gas in the compression side chamber B moves to the outer periphery of the piston body 30 and the piston ring 34. Inner circumference of stopper 31 and notch of stopper 31
The stay damper A is allowed to flow into the extension side chamber A through 31a, so that the stay damper can be quickly contracted.

[Problems to be solved by the device]

By the way, in the case of equipping the actual vehicle with the stay damper formed as described above, it is assumed that the oil that also serves as the lubricating oil is housed inside, and that the oil has a great damping effect when fully extended. I am trying.

That is, as shown in FIG. 7, in the stay damper disposed between the vehicle body C and the door D, the inlet end of the labyrinth groove (not shown) formed in the piston portion 3 is indicated by an arrow in the figure. As described above, when the door D is in the so-called upper side, from the state where the door D is fully closed (lower stage in the figure) to the half-open state (middle stage in the figure),
Only the gas passes through the labyrinth groove, but when it is in the fully opened state (upper part in the figure), the oil passes through the labyrinth groove, and therefore a large damping effect is exerted when the stay damper is fully extended, You can't invite a full-length shock.

However, in the case where the above-mentioned stay damper is mounted on an actual vehicle, and the entrance end of the labyrinth groove is not so-called the upper side but the lower side, it will be described with reference to FIG. Until then, the oil circulates in the labyrinth groove and becomes an extremely slow extension motion, but at the time of full extension, only the gas passes through the labyrinth groove, and therefore, there is a disadvantage that the shock reduction at full extension cannot be performed. Occurs.

Therefore, in the case of the above-mentioned conventional stay damper, from the assembling for the commercialization of the stay damper to the installation to the actual vehicle, the stay damper is left directional,
Alternatively, there is an inconvenience that an operation test (inspection) is required when the vehicle is mounted on an actual vehicle.

In view of the above-mentioned circumstances, the present invention is not subject to so-called directional restrictions not only during the assembly work but also during the mounting on the actual vehicle, and further, when the extension is completed, a predetermined extension cut can be prevented. The purpose is to newly provide such a stay damper.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, in the structure of the stay damper according to the present invention, the expansion side chamber and the compression side chamber defined by the piston portion in the cylinder are communicated via a labyrinth groove arranged in the piston portion. In the stay damper as described above, the labyrinth groove is formed in the end surface of the piston main body on the extension side chamber side, and the annular groove communicating with the inlet end of the labyrinth groove is provided on the outer periphery of the labyrinth groove, and The annular groove is characterized in that it is communicated with the extension side chamber through a plurality of communication holes opened at appropriate intervals in the circumferential direction.

[Action]

Therefore, even when the inlet end of the labyrinth groove is so-called on the lower side, for example, when the communication holes are opened at 120 ° intervals, one of the plurality of communication holes is always gas. It will be distributed inside.

Therefore, the gas in the expansion side chamber preferentially passes through the labyrinth groove and flows out to the pressure side chamber until the stay damper is close to the fully expanded state. Pass through the labyrinth ditch.

That is, when the stay damper is installed in an actual vehicle, it is not necessary to predict whether the entrance end of the labyrinth groove is above or below, and confirmation thereof is also unnecessary.

Further, at the time of assembling the stay damper, it is not necessary to set the installation position of the inlet end of the labyrinth groove with respect to the piston rod, for example, vertically.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

The stay damper according to the present invention is called a gas damper like the above-mentioned conventional example, and as shown in FIG.
Piston rod 2 inserted into and retracted from cylinder 1
The piston portion 3 slidably accommodated in the cylinder 1 defines the expansion side chamber A and the compression side chamber B.

The piston portion 3 is, of course, connected to the tip of the piston rod 2 (right end in the figure).

The piston part 3 includes a piston body 30 and a stopper 31.
And a washer 32, which are sequentially inserted in the spigot portion 2a of the piston rod 2 and fixed by the piston nut 33 screwed to the threaded portion 2b of the piston rod 2.

A piston ring 34, whose outer circumference is in sliding contact with the inner circumference of the cylinder 1, is provided on the outer circumference of the piston body 30.

The piston body 30 has its thickened portion along the axis (left and right in the figure)
Has a port 30a formed by piercing in the same direction, and both ends (left and right ends in the figure) of the port 30a are formed on both sides (the expansion side chamber A side and the compression side chamber B side) of the piston body 30, respectively. The labyrinth grooves 30b and 30c are opened.

As described above, the labyrinth groove is formed on both end surfaces of the piston body 30.
The fact that 30b and 30c are provided is not different from the above-mentioned conventional example.

However, in this invention, in addition to the labyrinth groove 30b, the end surface of the piston body 30 on the side of the extension side chamber A is
It is characterized in that the annular groove 30d is formed.

That is, as also shown in FIG. 2, an annular groove 30d is formed so as to surround the outer periphery of the labyrinth groove 30b on the end surface of the piston body 30 on the side of the expansion side chamber A. It is supposed that the inlet end 30e of the labyrinth groove 30b is open, and communication between the two is achieved.

Then, the annular groove 30d is connected to the extension side chamber A which is the outside through a plurality of communication holes 30f, 30g, 30h opened at appropriate intervals in the circumferential direction (equal intervals in the illustrated example, 120 degrees). It is in communication.

The stopper 31 is provided adjacent to the end surface of the expansion side chamber A formed as described above.

The stopper 31 includes the labyrinth groove 30b and the inlet end 30 thereof.
e, the annular groove 30d and the communication holes 30f, 30g, 30h are adjacently provided so as to be closed from the expansion side chamber A side, and the peripheral portion thereof appropriately has a cutout portion 31a. Due to the formation of the portion 31a, the gas (or oil) in the expansion side chamber A can be connected to the communication hole 30.
Care is taken to make it easy to flow into f, 30g, and 30h.

A washer 32 is provided adjacent to the end surface of the piston body 30 on the pressure side chamber B side.

The washer 32 inserts the labyrinth groove 30c into the pressure side chamber B
They are provided adjacent to each other so as to be closed from the side, and it is considered that only the outlet end 30i (see FIG. 1) is opened into the pressure side chamber B.

The labyrinth grooves 30b and 30c are formed in the same shape in this embodiment.
30b is formed in a meandering shape as shown in FIG.

A piston ring 34 is provided on the outer periphery of the piston body 30, and the piston ring 34 is
It is movable in the axial direction of 30 (left and right direction in FIG. 1).

Therefore, during the extension side stroke (when moving leftward in FIG. 1) when the piston portion 3 comes out of the cylinder 1, the piston ring 34 is in the so-called retracted position as shown in FIG. To close the gap formed between the piston body 30 and the cylinder 1.

On the other hand, during the compression side stroke (when moving to the right in FIG. 1) when the piston portion 3 is retracted into the cylinder 1, the piston ring 34 is in a so-called floating state as shown in FIG. Then, the gap formed between the piston body 30 and the cylinder 1 is released (see the lower part in FIG. 3).

Therefore, in the stay damper according to this embodiment formed as described above, an appropriate amount of oil is stored inside during assembly.

The oil improves the slidability of the piston portion 3 with respect to the cylinder 1 and the slidability of the piston rod 2 with respect to the cylinder 1, and also prevents the occurrence of stretch-cutting shock when the stay damper is fully stretched.

That is, when the stay damper is installed in an actual vehicle, for example, referring to FIG. 7, the piston rod 2 will be described.
While the cylinder 1 is connected to the vehicle body C side and the cylinder 1 is connected to the door D side to be mounted on an actual vehicle, even if the inlet end 30e of the labyrinth groove 30b in the piston portion 3 is on the so-called lower side, In the annular groove 30d that communicates with the inlet end 30e, the inflow of gas from any one of the plurality of communication holes 30f, 30g, 30h in the gas is given priority, and the inside of the extension side chamber A After almost all the gas has flowed into the pressure side chamber B, the oil flows into the pressure side chamber B through the labyrinth groove 30b.

That is, only the gas flows in the labyrinth groove 30b until the time when the stay damper is almost fully extended, and then the oil flows in the labyrinth groove 30b.

Therefore, during the extension side stroke in which the piston portion 3 comes out of the cylinder 1, it is possible to quickly extend until near the full extension, and at the same time, until the subsequent full extension, a slow extension is possible. This makes it possible to prevent the stretch damper from being extended to the stay damper.

This also means that the piston rod 2 of the stay damper is freely rotated, and accordingly, the piston portion 3 is mounted on the actual vehicle without the directionality of the piston portion 3 being restricted with respect to the cylinder 1. The same is true even if the device is installed in the reverse configuration as described above.

When the stay damper, which has been in the fully extended state as described above, is reversed to the compression side stroke, the piston ring 34 interposed on the outer periphery of the piston body 30 moves to move the piston body 30.
A gap is formed between the cylinder 1 and the cylinder 1 and opened to allow oil to flow into the extension side chamber A.

That is, during the compression side stroke, the extension side chamber A and the compression side chamber B are communicated with each other without using the labyrinth groove 30b, and therefore, the stay damper can be quickly contracted.

In the above description, there are three communication holes that communicate the annular groove 30d and the extension side chamber A, but it is needless to say that four or more communication holes may be used instead.

[Effect of device]

As described above, according to the present invention, the inlet end of the labyrinth groove is freely rotated by axial rotation about the piston rod shaft of the piston portion, and even if it is oriented in any direction, While an annular groove is formed on the outer circumference of the annular groove, a plurality of communication holes are formed in the annular groove so that any one of the communication holes is always in gas. Regardless of whether the mounting position is upright or upside down, it is always possible to quickly extend up to near full extension, but at the time of full extension, it is effective to effectively prevent full extension shock. There is.

Therefore, the position of the piston part with respect to the piston rod is not regulated during the assembly work, and the work is speeded up. Also, the mounting position is not regulated during the transportation or the mounting on the actual vehicle, and the work is easy. Produces the effect of becoming.

[Brief description of drawings]

FIG. 1 is a partial front view showing a stay damper according to an optimum embodiment of the present invention by partially breaking it, FIG. 2 is a side view showing an end face of a piston body, and FIG. 4 is a partially cutaway front view showing a conventional stay damper, FIG. 5 is a partially enlarged front view of the same, FIG. 6 is a side view showing the end face of the piston body, and FIG. FIG. 1 is a schematic view showing an operation example of a conventional stay damper in multiple stages. [Explanation of appendices] 1 ... Cylinder, 2 ... Piston rod, 3 ... Piston part, 30 ... Piston body, 30a ... Port, 30b, 30c ...
… Labyrinth groove, 30d …… Annular groove, 30e …… Inlet end, 30f,
30g, 30h ... Communication hole, A ... Extension side chamber, B ... Pressure side chamber.

Claims (1)

[Scope of utility model registration request] 1. A stay damper comprising: an extension side chamber and a compression side chamber, which are defined by a piston portion in a cylinder, and are communicated with each other via a labyrinth groove arranged in the piston portion.
The labyrinth groove is formed in the end surface of the piston body on the expansion side chamber side, and an annular groove communicating with the inlet end of the labyrinth groove is provided on the outer periphery of the labyrinth groove, and
A stay damper, wherein the annular groove is communicated with the extension side chamber through a plurality of communication holes opened at appropriate intervals in the circumferential direction.