JP2805049B2 - Stay damper - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stay damper capable of increasing an extended holding force of the stay damper.

[Conventional technology]

If the stay damper does not have sufficient holding force in the extended state, for example, when the stay damper is used to open the rear door of an automobile, the opened rear door is suddenly closed by a slight external force such as wind. It is extremely dangerous because it leads to an unexpected accident.

Therefore, the applicant of the present application has previously proposed a stay damper shown in FIG. 3 as a stay damper for securing a large holding force at the time of extension.

In the stay damper, a rod-side oil chamber A and a piston-side oil chamber B are formed in the cylinder 1 by a piston part 3 disposed at a front end spigot part 2a of a piston rod 2 inserted and retracted into and out of the cylinder 1. Do it.

In the stay damper, an annular stopper 4 whose outer periphery is in close contact with the inner periphery of the cylinder 1 is fixed in the rod-side oil chamber A by caulking the outer periphery of the cylinder 1 (indicated by a symbol a in the drawing). And the stopper 4
, A negative pressure chamber R is formed in the rod side oil chamber A.

Incidentally, the negative pressure chamber R and the rod side oil chamber A are provided in the stopper 4.
A port 4a communicating with the stopper 4 is opened, and an annular stop rubber 5 is provided adjacent to an end surface 4b of the stopper 4 on the rod-side oil chamber A side so as to be detachable and seatable. It is stated that the opening of the port 4a is closed at the time of adjacency.

In addition, seals 6 and 7 made of O-rings are interposed on the inner and outer circumferences of the stopper 4, respectively, to ensure a predetermined sealing performance.

On the other hand, a cylindrical collar 8 is interposed in the front spigot portion 2a of the piston rod 2 so as to be in series with the piston portion 3, and when the stay damper is extended, the outer periphery of the collar 8 is inside the stopper 4. It is said to be in sliding contact with the circumference.

An annular seal housing 9 is formed by caulking the outer periphery of the cylinder 1 (symbol b in the figure) so that a negative pressure chamber R is defined between the inner periphery of the cylinder 1 and the end 1a of the cylinder 1 and the stopper 4. (Indicated by)).

In addition, seals 10 and 11 made of O-rings are interposed on the inner and outer circumferences of the seal housing 9, respectively, to secure a predetermined sealing performance.

Therefore, in the stay damper as the conventional proposal, when the piston portion 3 slides in the extension side (left side in the drawing) in the cylinder 1, the hydraulic oil in the rod-side oil chamber A is removed from the piston portion. 3 through the orifice 30a of the valve 30 and the port 31a of the piston body 31.
And the stay damper is allowed to elongate.

Then, when the piston portion 3 makes a large stroke in the cylinder 1 and the stay damper is near the time of extension, the outer periphery of the collar 8 interposed in the front spigot portion 2a of the piston rod 2 becomes the inner periphery of the stopper 4. At the same time, the collar 8 slides into the negative pressure chamber R.

At this time, when the collar 8 enters, the hydraulic oil in the negative pressure chamber R flows out to the rod-side oil chamber A through the port 4a of the stopper 4, and the stay damper can be extended.

On the other hand, when the stay damper is in the extended state, the piston portion 3 is adjacent to the stop rubber 5 and the stop rubber 5 is adjacent to the end surface 4b of the stopper 4 on the rod-side oil chamber A side (illustrated state). The further stroke of is stopped.

At this time, the opening of the port 4a is closed by the stop rubber 5 adjacent to the end face 4b of the stopper 4, and the negative pressure chamber R
Of hydraulic oil between the oil chamber A and the rod-side oil chamber A,
The inflow of hydraulic oil from the rod-side oil chamber A to the negative-pressure chamber R is prevented under high sealing performance.

Therefore, even if the stay damper is compressed from the extended state by the action of an external force such as wind, and the piston rod 2 is stroked in the compression side (right side in the drawing), even if the piston rod 2 is stroked in the compression side (right side in the figure), Is blocked by closing the port 4a, and a negative pressure is generated in the negative pressure chamber R, that is, a repulsive force for preventing the piston rod 2 from moving in the pressure side direction is generated. Becomes the holding force of the extended state, and the extended state of the stay damper is maintained.

When the stay damper in the extended state is compressed with a strong force exceeding the repulsive force, the collar 8 interposed in the front spigot portion 2a of the piston rod 2 slides on the inner peripheral side of the stopper 4, and Inner circumference of stopper 4 and piston rod 2
Hydraulic oil flows into the negative pressure chamber R through a slight gap formed between the piston rod 2 and the outer periphery of the piston rod 2, the negative pressure phenomenon in the negative pressure chamber R is released, and the piston rod 2 moves toward the pressure side. A stroke is allowed, and the stay damper can be compressed.

Therefore, the stay damper according to the conventional proposal has an advantage that the holding force of the extended state at the time of the extended state is sufficiently and reliably exerted.

(Problems to be Solved by the Invention) However, the above-mentioned conventional proposals have disadvantages such as that the effective stroke of the stay damper is greatly reduced and high sealing performance cannot be expected.

That is, in the above-mentioned conventional proposal, the negative pressure chamber R for generating a negative pressure as a holding force in the extended state when the stay damper is extended is formed between the stopper 4 in the cylinder 1 and the seal housing 9. It is going to be.

Then, the stopper 4 is disposed on the inner periphery of the cylinder 1.
The seal housing 9 is also fixed in the outer peripheral portion of the cylinder 1 by a caulking process (indicated by a symbol b). It will be set up.

That is, in the above-mentioned conventional proposal, the stopper 4 and the seal housing 9 are disposed in a so-called separated manner in the cylinder 1, so that the distance between the stoppers and the seal housing 9 tends to be long in size, and the stay damper is not easily provided. There is the disadvantage that the effective stroke is reduced.

Further, in the above conventional proposal, the end face of the stopper 4
Since the stop rubber 5 is assumed to be adjacent to the stop rubber 4a so as to be detachable and seatable, it is difficult to reduce the axial length of the stopper 4 and the stop rubber 5, and therefore, the effective stroke of the stay damper is also considered from this point. Is disadvantageously reduced.

On the other hand, the inner and outer peripheries of the stopper 4 and the inner and outer peripheries of the seal housing 9 are provided with seals 6, 7 and
0 and 11 are interposed, and a predetermined sealing performance is ensured by the seals 6, 7 and 10, 11.

In particular, since the inner seals 6 and 10 are in sliding contact with the outer circumference of the piston rod 2, respectively, the seals 6 and 10 are required to have high sealing performance.

However, since the stopper 4 and the seal housing 9 are independently fixed to the inner periphery of the cylinder 1 by crimping, there is a disadvantage that it is not possible to easily secure so-called concentricity with the piston rod 2 for both.

Therefore, there is a disadvantage that the seals 6 and 10 on the inner peripheral side of the stopper 4 and the seal housing 9 cannot be expected to have high sealing performance.

Further, in the stay damper as the conventional proposal, the stopper 4 and the seal housing 9 are each provided with two caulking processes on the outer periphery of the cylinder 1 (reference numerals a,
Since the fixing is performed at the predetermined position in the part (b), there is also a disadvantage that the so-called assemblability is hardly improved.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object the purpose of not significantly reducing the effective stroke thereof, easily ensuring high sealing performance, and further improving the assembly efficiency. Another object of the present invention is to provide a stay damper with improved performance.

[Means for solving the problem]

In order to achieve the above object, a means of the present invention is to provide a cylindrical collar and a piston portion in series at a lower portion of a piston rod, and the piston rod is inserted through the piston portion so as to be able to protrude and retract into the cylinder, The section defines a rod-side oil chamber and a piston-side oil chamber in a cylinder, and a cylindrical stopper is provided above the rod-side oil chamber. In the stay damper adapted to be fitted to the stopper, the stopper is constituted by a cylindrical main body part provided with a seal on the inner periphery and a hollow housing part integrally formed above the main body part. Forms a negative pressure chamber communicating with the rod-side oil chamber through the center of the main body, and the outer periphery of the housing is fixed to the inner periphery of the cylinder and fitted to the outer periphery of the piston rod via a seal. The negative pressure chamber is connected to a rod-side oil chamber via a port formed in a stopper, and a check valve that allows oil flow only from the negative pressure chamber to the rod-side oil chamber is provided in the middle of the port so as to be freely opened and closed. It is characterized by the following.

[Action]

When the piston rod makes a large stroke in the extension direction in the cylinder and the stay damper is near the time of extension, the hydraulic oil in the negative pressure chamber flows out to the rod side oil chamber side through the port and the check valve, and the stay damper Enables incision.

On the other hand, when the stay damper is extended, the check valve shuts off the port. Therefore, the flow of the hydraulic oil between the negative pressure chamber and the rod-side oil chamber side, particularly, the flow of the hydraulic oil into the negative pressure chamber Inflow is blocked under high closure performance.

Therefore, even if the stay damper is compressed by the external force such as wind from the extended state and the piston rod is stroked in the compression direction, the flow of the hydraulic oil into the negative pressure chamber is checked. Negative pressure which is prevented by the valve and prevents the piston rod from being stroked in the pressure side in the negative pressure chamber, that is, a repulsive force is generated, and the repulsive force becomes a holding force of the stay damper in the extended state.

When the stay damper in the extended state is compressed with a strong force exceeding the negative pressure, the collar interposed in the piston rod slides on the inner peripheral side of the main body, and the inner periphery of the main body and the collar are rotated. Hydraulic oil flows into the negative pressure chamber through the outer periphery of the negative pressure chamber, and the negative pressure phenomenon in the negative pressure chamber is released.
A stroke in the pressure side direction of the piston rod is allowed,
The stay damper is returned to a compressible state.

〔Example〕

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

As shown in FIG. 1, a stay damper according to an embodiment of the present invention includes a piston rod 3 which is inserted into a cylinder 1 so as to be able to protrude and retract so as to be inserted into the cylinder 1 with a piston part 3 provided continuously with a front end spigot part 2a. A rod-side oil chamber A and a piston-side oil chamber B are defined.

In this embodiment, although not shown, a gas chamber partitioned by a free piston is formed in the piston side oil chamber B, and the stay damper always extends in the extending direction by the gas pressure in the gas chamber. Has been urged.

The rod-side oil chamber A and the piston-side oil chamber B are communicated with each other via a piston portion 3 described later. The rod-side oil chamber A has a negative pressure chamber R in the rod-side oil chamber A. Is formed.

However, in this embodiment, the stopper 4 is formed as follows.

That is, the stopper 4 includes the main body 40 and the housing 41
And a connecting portion 42 for connecting the two, and is formed in an annular shape with a substantially concave cross section, and a negative pressure chamber R is formed on the inner peripheral side of the connecting portion 42.

The stopper 4 is fixed to the inner periphery of the cylinder 1 by crimping the outer periphery of the cylinder 1 (indicated by the symbol b in the drawing) while the housing portion 41 is fixed to the outer periphery of the main body 40 by the cylinder. An oil passage L is formed between the oil passage L and the inner periphery of the oil passage L.

The oil passage L communicates the negative pressure chamber R and the rod-side oil chamber A, and a check valve C is provided in the oil passage L. In the present invention, the check valve C Is the stopper 4
Are arranged on the outer periphery of the main body 40 in FIG.

Further, a port 42c for communicating the negative pressure chamber R with the oil passage L is opened in the connecting portion 42.

The main body 40 is provided with a seal 6 made of an O-ring on the inner periphery thereof to ensure a so-called sealing property on the inner periphery of the main body 40. Being adjacent.

On the other hand, the housing part 41 is provided integrally with the main body part 40 to form a seal housing.
The so-called sealing properties at the inner and outer peripheries are secured by interposing the seals 10 and 11 composed of rings.

The housing portion 41 is provided on the outer periphery of the cylinder 1 so as to be aimed at the seal 11 on the outer periphery thereof, and is fixed to the inner periphery of the cylinder 1 by caulking (indicated by reference numeral b in the drawing).

Therefore, in the present invention, the stopper 4 is formed so as to also serve as a seal housing by itself, so that the stopper 4 can be shortened, that is, downsized, and the effective use of the piston rod 2 in the cylinder 1 can be achieved. This makes it possible to increase the stroke and, if necessary, to shorten the stay damper itself.

In the present invention, since the check valve C is provided on the outer periphery of the main body 40 in the stopper 4, the length of the stopper 4 in the axial direction can be greatly reduced.

The stopper 4 is fixed at a predetermined position in the cylinder 1 by caulking at one place in the housing portion 41. Therefore, the piston rod 2 of the stopper 4
Concentricity can easily be ensured.

Incidentally, the check valve C disposed on the outer periphery of the stopper 4, that is, in the illustrated example, on the outer periphery of the main body portion 40 in this embodiment is constituted by an annular lip seal 20, and the lip portion 20a is formed of a cylinder. 1 is in sliding contact with the inner circumference.

Further, a metal 20b is continuously provided on the inner peripheral side of the lip seal 20, so that the metal 20b is stably fixed to the main body 40.

On the other hand, a cylindrical collar 8 is interposed in the front spigot part 2a of the piston rod 2 so as to be in series with the piston part 3, and the outer periphery of the collar 8 is a stopper 4 when the stay damper is extended. It is slid on the inner periphery of the part 40.

In addition, a concave groove 2b is formed on the outer periphery of the front end spigot portion 2a of the piston rod 2 with which the inner periphery of the collar 8 is opposed, and a seal 13 is interposed in the concave groove 2b to form the collar 8. A so-called sealing property is secured between the inner circumference and the outer circumference of the front spigot portion 2a facing the inner circumference.

By the way, in this embodiment, the end of the cylinder 1
On the inner circumference of 1a, a bearing 14 in which the outer circumference of the piston rod 2 slides in contact with the inner circumference and a main seal 15 adjacent to the bearing 14 are provided.
A metal 16 is disposed on the surface adjacent to the bearing 14, so that the self-supporting property of the main seal 15 is ensured.

Further, in this embodiment, the piston part 3 is provided with a valve 30.
, A piston main body 31 and a valve stopper 32.

In this embodiment, the valve 30 is a so-called extension-side valve, is disposed adjacent to the end surface of the piston body 31 on the rod-side oil chamber A side (the left side in the figure), and is opened in the piston body 31. The opening of the port 31a on the rod-side oil chamber A side is closed, and the port 31a is fully opened by the outer peripheral end bending,
Hydraulic oil from the piston side oil chamber B is allowed to flow into the rod side oil chamber A.

The valve 30 has an orifice 30a formed through the thickness thereof, and when the valve 30 is closed, hydraulic oil from the rod-side oil chamber A is supplied to the port 31a through the orifice 30a. Out, ie, into the piston side oil chamber B.

Then, it is described that a predetermined damping force is generated by the flow path resistance when the hydraulic oil passes through the orifice 30a.

The piston body 31 is formed so that the outer periphery thereof is in sliding contact with the inner periphery of the cylinder 1, and is interposed in the front spigot portion 2 a of the piston rod 2 and screwed in the front end screw portion 2 c of the piston rod 2. The piston nut 33 is set at a predetermined position.

The piston body 31 has a port 31a formed in a thick portion thereof so as to penetrate the piston body 31 in the axial direction. As described above, the port 31a is connected to the rod side oil chamber A and the piston side. Communication with the oil chamber B is allowed.

The valve stopper 32 regulates the lift amount of the valve 30, and has a cutout hole 32a formed on the inner peripheral side thereof to allow the flow of hydraulic oil.

The valve stopper 32 contacts the end surface 4a of the stopper 4 on the rod side oil chamber A side when the stay damper is extended.

The stay damper according to this embodiment formed as described above operates as follows.

First, when the external force that prevents the stay damper from being extended is released, the piston portion 3 slides in the cylinder 1 in the extension side (left side in the drawing), and the piston rod 2 moves out of the cylinder 1 to the end 1a. , And the stay damper is extended.

At this time, as the piston rod 2 withdraws from the inside of the cylinder 1, the hydraulic oil in the rod side oil chamber A flows into the port 31a of the piston body 31 through the orifice 30a of the valve 30, and the piston It flows out into the side oil chamber B.

Next, when the movement of the piston rod 2 advances and the stay damper is near the time of extension, the tip of the collar 8 interposed in the front spigot portion 2a of the piston rod 2
Into the inner periphery of the main body 40 at

Therefore, the operating oil in the negative pressure chamber R formed on the inner peripheral side of the stopper 4, that is, on the inner peripheral side of the connecting portion 42, is connected to the port 42a of the connecting portion 42 and the oil passage L communicating with the port 42a. And a check valve C composed of a lip seal 20 disposed in the oil passage L.
Flows out to the rod-side oil chamber A side via.

When the piston rod 2 moves further in the extension direction and the stay damper reaches the extended state, the valve stopper 32 of the piston portion 3 is adjacent to the end surface 40b of the main body portion 40, which is the end surface 4a of the stopper 4. Here,
Further extension of the stay damper is prevented.

When the stay damper is compressed by the action of an external force such as wind from the extended state, the oil passage L is closed by the action of the check valve C, and the hydraulic oil is introduced into the negative pressure chamber R. Is prevented, the negative pressure in the negative pressure chamber R is secured, and a repulsive force is generated to prevent the piston rod 2 from being stroked in the pressure side (right side in the figure). The force is the holding force of the stay damper in the extended state.

On the other hand, when the stay damper in the extended state is compressed with a strong force exceeding the negative pressure, the collar 8 interposed in the piston rod 2 slides on the inner peripheral side of the main body 40 in the stopper 4, and Hydraulic oil flows into the negative pressure chamber R through the space between the inner circumference of the main body 40 and the outer circumference of the collar 8, and the negative pressure phenomenon in the negative pressure chamber R is released. Stroke is allowed,
The stay damper is returned to a compressible state.

When the piston portion 3 slides in the pressure side in the cylinder 1, the operating oil that is insufficient in the rod-side oil chamber A is supplied to the port 31 a of the piston body 31 in the piston portion 3.
Then, it flows from the piston side oil chamber B through the opened valve 30, and the compression of the stay damper is permitted.

FIG. 2 shows a stay damper according to another embodiment of the present invention. Even in the stay damper according to this embodiment, the basic configuration is the same as that of the above-described embodiment. , The structure of the check valve C is different.

Therefore, the following description focuses on the check valve C portion, and the other portions are denoted by the same reference numerals as in the above-described embodiment, and detailed description thereof is omitted.

That is, the check valve C in this embodiment is configured by the annular elastic belt 21 and is interposed on the outer periphery of the connecting portion 42 between the main body 40 and the housing 41 of the stopper 4.

The connecting portion 42 is provided with a port 42a for allowing communication between the negative pressure chamber R and the oil passage L. Therefore, in this embodiment, the check valve C comprising the elastic belt 21 is provided.
Is disposed so as to close the opening of the port 42a.

According to this embodiment, the structure of the check valve C itself is simplified. Therefore, according to this embodiment, there is no fear that a failure due to its complexity will be caused, and furthermore, it can be manufactured at low cost. There are advantages.

Although the stay damper according to the present invention has been described as being for opening the rear door of the vehicle, the stay damper may be a stay damper for a smoke exhaust window in a building. Of course, the configuration, operation and effect are not different.

〔The invention's effect〕

 As described above, the present invention has the following effects.

Since a high negative pressure can be generated in the negative pressure chamber when the stay damper is extended, a sufficient holding force can be easily ensured when the stay damper is extended.

At this time, since a high-performance and expensive seal member and a plurality of seal members are not required, the stay damper can be manufactured under economically advantageous conditions, and the operability is not reduced.

The stopper is formed integrally with the housing portion connected to the main body portion, and the housing portion is fixed to the inner periphery of the cylinder, and in the middle of a port communicating the negative pressure chamber and the rod side oil chamber. Since the check valve is provided, the length of the stopper portion in the axial direction is shortened, so that the effective stroke of the piston rod in the cylinder is not significantly reduced. Only one place is required, and the assemblability is improved.

The stopper is integrally formed so as to also serve as the seal housing, so that it is easy to ensure concentricity with the piston rod.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing a cut-away state of a stay damper according to an embodiment of the present invention, and FIG. 2 is a partially cut-away view of a stay damper according to another embodiment of the present invention. FIG. 3 is a partial sectional front view showing a stay damper according to a conventional example in a partially cut-out state. (Explanation of reference numerals) 1 ... Cylinder 2 ... Piston rod 2a ... Inner end section 3 ... Piston section 4 ... Stopper 40 ... Main body section 41 ... Housing section A ... Rod side oil chamber R ... Negative pressure chamber

Claims (1)

(57) [Claims] A cylindrical collar and a piston portion are provided in series at a lower portion of a piston rod, and the piston rod is inserted through a piston portion so as to be able to protrude and retract into a cylinder. And a piston-side oil chamber, a cylindrical stopper is provided above the rod-side oil chamber, and when extended, the collar is fitted to the inner circumference of the stopper via a seal on the inner circumference of the stopper. The stopper is composed of a cylindrical main body having a seal on the inner periphery and a hollow housing part integrally formed above the main body. The housing has a rod-side oil through the center of the main body. A negative pressure chamber communicating with the chamber is formed, and the outer periphery of the housing portion is fixed to the inner periphery of the cylinder and fitted to the outer periphery of the piston rod via a seal, and the negative pressure chamber is formed in a stopper. It is connected to the rod side oil chamber through the port, characterized in that a check valve that allows the flow of seed oil from the negative pressure chamber in the middle of the port to the rod side oil chamber is provided openably Sutedanpa.