JP2791672B2 - Stay damper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is most suitable as a stay damper for assisting opening and closing of a rear gate in a hatchback type four-wheeled vehicle. About.

[Conventional technology]

As is well known, a stay damper as a rear gate opening / closing aid in a hatchback vehicle functions to smoothly open and close a hatchback door by using a piston rod reaction force caused by a fluid pressure of gas or the like, and Works to limit the maximum length of the stay.

However, according to the door including such opening / closing means,
In the fully open state, it is preferable to flip up the door tip as high as possible for convenient loading and unloading, etc.On the other hand, for short-height users, etc., the flipped-up door tip cannot reach, There are also inconveniences such as difficulty in closing the door by lowering.

Therefore, in the conventional means of this kind, a main body cover cylinder integral with the telescopic rod of the stay damper is provided, and an engagement bolt is screwed in from an appropriate position of the cover cylinder to abut the flange edge of the main body end with the bolt. Prevents the rod from stretching,
An intermediate stopper method for regulating the door opening at this position, and further, a cam groove formed in a stepped manner is formed in the cover cylinder, and a locking pin protruding from the main body side is fitted into this.
By rotating the cover cylinder at the time of use, the position of the step groove with respect to the pin is changed, and a multi-stage stopper system or the like that regulates the extension length of the rod by the step abutment of the pin in the step groove at that time is adopted. Thus, the door can be opened in a two-stage manner, that is, holding the door halfway open and fully opening the door.

[Problems to be solved by the invention]

By the way, such a two-stage opening configuration of the stay damper requires manual work such as screwing of the engagement bottle in the cover cylinder or rotating operation of the cover cylinder itself when the intermediate stopper function is required. In addition, there is a drawback that the stay damper itself becomes bulky due to the presence of the cover cylinder.

Further, in the case of using the bottle tightening means, when the tightening operation is performed in a state close to the fully opened door, the bolt is erroneously protruded into the main body side in an outer region beyond the locking jaw edge, so that the door is closed. At this time, since the bolt hits the flange edge from the outside, there is a concern that a malfunction of the mechanism often occurs due to a work error, such as a state where the door cannot be closed thereafter.

Therefore, the present invention is a stay damper having a two-stage opening function, which eliminates such an individual user or a manual operation each time the function is exhibited, and particularly, a device excellent in positioning accuracy in the latter half of the two-stage opening. The purpose of the development.

[Means for solving the problem]

Therefore, according to the present invention, according to the present invention, the inside diameter of a predetermined section corresponding to the latter stage of the extension stroke of the piston rod in the cylinder is configured to be small, while the piston rod is provided with the predetermined section from the piston portion at the tip thereof. A check seal function that acts only on the inner wall of the small-diameter cylinder is provided at a position corresponding to a distance corresponding to the distance between the small-diameter cylinder chamber and the piston that are closed by the check seal function during the expansion and contraction stroke. This can be achieved by a stay damper configured to release the working fluid while generating a constant inter-chamber pressure difference between the other cylinder chamber and an external force applied to the piston rod.

(Operation)

The check seal function portion mounted on the outer periphery of the piston rod exerts its function only on the small diameter portion of the cylinder inner wall.

That is, when the check seal function part reaches the small diameter part of the cylinder in the extension side stroke of the piston rod, the function part which has formed a gap flow path of the working fluid with the large diameter cylinder inner wall until then, Since the flow of the working fluid is blocked in close contact with the inner wall of the large-diameter cylinder, the cylinder chamber surrounded by the small-diameter inner wall is in an oil lock state.

When an external operating force (external force) is applied to the piston rod receiving the chamber pressure of the cylinder chamber in the locked state, depending on the direction of the force, for example, in the extension side stroke in which the piston rod extends. The hydraulic oil in the small-diameter cylinder chamber closed by the check seal function unit is opened toward the other cylinder chamber while generating a constant differential pressure by an operating force applied to the piston rod, and conversely, compressed. In the stroke, the two chambers communicate with each other by the flow of the check seal function part in the opening direction, and the piston rod can be pushed in the direction of compression with a relatively small operating force.

In this case, the configuration in which the inner wall of the cylinder is made small in diameter is effective in increasing the volume of fluid movement during operation in this region in spite of a small change in the diameter length from the large diameter portion. To work.

〔Example〕

 Next, an illustrated embodiment of the present invention will be described.

FIG. 1 is a half cut vertical sectional view showing a main part of an embodiment of the present invention. A piston rod 3 holding a piston 2 slidably fitted to a cylinder 1 at a tip thereof has a bearing provided with a seal member 4. It is removably assembled into the cylinder 1 by a mechanism 5.

Then, this cylinder 1, the inside diameter length D ₂ reduced from several millimeters shorter internal diameter length D ₁ becomes a predetermined length than diameter tubular portion 6
And a cylinder body including a stroke restricting ring 7 integrated with the cylindrical member, and the ring 7 is caulked at a position close to the bearing mechanism 5.

On the other hand, a stopper 8 is fixed to the outer peripheral groove 9 of the piston rod 3 in a position corresponding to a predetermined length (section) of the reduced-diameter cylindrical portion 6 from the rear end of the piston 2. A check seal 10 is press-fitted between the piston 2 and the stopper 8 close to the stopper 8 and is fixed by a C-pin 11 so as not to be displaced.

Further, the piston rod 3 is provided with a hollow passage 13 having a peripheral port 12 opened on the side facing the check seal 10 with the stopper 8 interposed therebetween and opened at the rod tip,
An O-ring 17 is press-fitted into an enlarged annular groove 16 of an orifice port 15 opened in a piston nut assembly 14 having a closed end face, and a pressure-side closing valve mechanism configured by pressing an O-ring 17 into the chamber A in the cylinder 1. The communication with the chamber B is established.

On the other hand, another communication passage 18 is opened in the piston 2 fixed to the rod end by tightening the piston nut assembly 14, and the seat surface of the communication passage 18 on the chamber A side and the valve stopper A non-return valve 20 having an orifice hole 21 is disposed between the valve and the valve 19.

FIG. 2 is a half sectional view showing another embodiment of the present invention, wherein the same functional components as those in the first embodiment shown in FIG. the cylinder diameter portion checking seal 10 side acts, Yes from the inner diameter length D ₂ of the piston operating area constituted by shortening as no steps on the inner diameter length D _2, further, O-ring in the pressure side closing valve mechanism An annular band 17 'made of an elastic material is used instead of 17.

As the pressure-side closing valve mechanism, as shown in FIG.
A spherical body 22 made of an elastic material (rubber or the like) having a certain amount of interference by the piston nut assembly 14 may be directly applied to the opening surface of the tip of the piston nut assembly 14.

FIG. 4 shows another configuration of the check seal function portion according to the present invention. A thick cylindrical stopper 8 'corresponding to the stopper 8 is provided with a tongue piece 23 at the front end edge of the outer peripheral groove 9. ′ Is fixed to the piston rod 3 by crimping.

On the outer periphery of the stopper 8 ', an O-ring 24 and a back-up 25 for slidably contacting only the inner wall of the small-diameter portion of the cylinder 1 and exhibiting a sealing action are arranged. Through hole 26 formed in the thick part of the stopper
An annular band 28 made of an elastic material is press-fitted into an opening groove 27 on the side of the stopper working end.

According to the embodiment having such a configuration, first, the first
In the embodiment shown, the piston rod 3 is
The check seal 10 fixed to the rod 3 is moved in a direction of extending from the most compressed state fully pushed into the check seal 10.
The outer lip, as this passes through the cylinder area of the thick inner diameter D ₂ is up to the tip of the reduced diameter cylindrical portion 6, without coming into contact with the cylinder inner wall of the zone, which like the annular gap between the Has formed.

Accordingly, the moving range of the piston rod 3 during this period is set as the range of the first stroke, and during the operation, the hydraulic oil passes through the annular gap from the chamber A in the cylinder divided by the piston 2 to the chamber B. Since the piston rod 3 can be moved without resistance, the piston rod 3, that is, the hatchback door to which the piston rod 3 is attached can be easily flipped up. When the door is released in the middle of this operation range, the door is smoothly closed from its position by its own weight. Turn down from the door tip toward.

Then, when the check seal 10 reaches the tip inclined end of the reduced-diameter cylindrical portion 6 in the previous extension stroke, the outer lip thereof comes into sliding contact with the inner wall of the small-diameter reduced-diameter cylindrical portion 6, so that the chamber A is oil-locked. State.

In this oil lock state, the piston rod 3
Since the locked state cannot be released with the door load applied to the rod, the rod 3 and the hatchback door integrated with the rod 3 are located at the intermediate position when shifting from the first stroke range to the second stroke range. Is held in.

When an external force (operating force such as pushing up the door) is further applied to the piston rod 3 from this state, the internal pressure of the chamber A pushed by the check seal 10 becomes higher than the internal pressure of the chamber B by the differential pressure ΔP. . As a result, the hydraulic oil that has reached the orifice 15 from the chamber A through the hollow passage 13 pushes the O-ring 17 assembled in the enlarged-diameter groove 16 against the tightening elasticity to open it. Move toward B.

Therefore, as the hydraulic oil moves, the piston rod 3
Can be further moved in the extension direction, and can be continuously operated to a position where the stroke regulating ring 7 and the stopper 8 at the maximum movement position come into contact with each other.

When the operation range due to the external force is set as the second stroke range, and the push-up operation on the front end of the door is interrupted during this time, the rod 3, that is, the door opening operation can be stopped and held at the interrupted position.

Next, when operating in the rod compression direction (door closing direction) from the position of the second stroke including the fully opened state, the tip of the opened door is strongly pressed down,
Since the hydraulic oil in the chamber B pushes and opens the non-return valve 20 through the communication passage 18 of the piston 2, pushes and opens the outer lip of the check seal 20 and flows into the chamber A through this,
The piston rod 3 can be gradually moved in the compression direction.

Moreover, the push-open of the outer lip of the check seal 10 at this time is caused by the fluid flowing from the chamber B to the chamber A.
Since the pressure can be set to about 2 kg / cm ^2, the compression operation of the piston rod 3, that is, the closing operation of the door, can be performed with substantially the same operating force as that of the conventional stay damper.

Of course, the check seal 10 of the rod 3 is
In the second stroke region where the rod 3 slides, the rod 3 can be stopped and held at an arbitrary operation position of the rod 3 even during the compression operation, as in the above-described extension operation.

And, as described above, the piston rod 3 that has reached the first-stage stroke region beyond the second-stage stroke region,
Since hydraulic oil flows freely through the passage gap formed between the cylinder inner wall of the seal 10 and the large diameter D _2, it can be operated lighter closing is in this area.

As described above, the piston rod 3 can be moved by changing the operation resistance in each of the first-stage and second-stage stroke regions. In particular, when the section is Scm in the range of the second-stage stroke, Check seal 10 moving between
The hydraulic oil amount Q discharged from the chamber A to the chamber B by
Q = (π / 4) · (D ₁ ² −d ² ) · S By the way, for this kind of operation purpose, a part of the piston rod is configured to have a large diameter d ₂ , while the cylinder inner wall has a large diameter. hydraulic oil amount Q ₁ discharged from the vessel chamber a side of the case of the configuration of arranging the check seal acts only against the diameter d _{2 portion, Q 1 = (π / 4} ) · (d 2 2 -d 1 ² ) · S In a general stay damper shape composed of D ₂ = 2 cm and d ₁ = 1 cm, the above D ₁ = 1.8 cm, d ₂ = When 1.2cm, Q = (π / 4 ) · (1.8 2 -1 2) · S = (π / 4) · 2.24SQ 1 = (π / 4) · (1.2 2 -1 2) · S = (Π / 4) · 0.44S.

Therefore, the ratio of Q to Q ₁ is about 5 times, and the case where the cylinder side is made small in diameter as in the embodiment of the present invention is about 5 times as compared with the case where the piston rod side is made small in diameter. The amount of discharged hydraulic oil can be obtained.

In addition, the positioning accuracy in such an operation range increases as the discharged hydraulic oil amount increases in such a case. Therefore, according to the embodiment of the present invention, the positioning accuracy is improved. I can do it.

Check This improving effect is, as another embodiment of the second illustrated, the cylinder inner diameter of the thick diameter length D _2, even when configured to the section with the small diameter length D _1, to move without a step during which By smoothly guiding the seal 10, in this embodiment, the same operation and effect as those of the embodiment shown in FIG. 1 are exhibited.

As shown in FIG. 3, a hollow passage of the piston rod 3 is provided.
The sphere 22 pressed directly against the opening surface of the tip of the valve 13 opens while deforming against the elasticity of the material due to the differential pressure ΔP generated on the side of the chamber A, despite its very simple construction. Can be performed properly.

The differential pressure .DELTA.P can be controlled and adjusted by the flow resistance of the orifice passage 15 and the tightening force of the O-ring 17 or the annular band 17 'in the embodiment shown in FIGS. It can be varied by the flow resistance of 15 and the axial interference by the piston nut assembly 14.

Also, the check seal 10 in the present invention is not limited to the configuration of the above-described embodiment, but may be any structure that exhibits its function. As an example, in the case of the configuration as shown in FIG. 4, the O-ring
Since 24 is a gap between the between the this and the cylinder inner wall is passing cylinder area of thick diameter length D ₂ occurs, firstly, can be extended with a relatively small operating force. When the O-ring 24 reaches the small-diameter portion of the cylinder 1, the O-ring 24 comes into contact with the inner wall of the small-diameter portion, and the passage 26 in the stopper 8 'is closed by the annular band 28.
The chamber A enters the oil lock state.

Up to this state, the rod is held at the intermediate position as the first-stage stroke range, and the operation proceeds to the subsequent second-stage stroke range. The operation in this range is performed in exactly the same manner as in the second embodiment shown in FIG. You can do it.

When compressing the piston rod 3 from the end stop position of the second stroke, first, the O-ring 24 and the small diameter of the cylinder
In the range where the inner wall of D ₁ is in sliding contact, the hydraulic oil from the chamber B passes through the passage 26 due to the movement of the O-ring 24 during this time, pushes and opens the annular band 28 and returns toward the chamber A. So
Also in this case, the operation can be performed with a small differential pressure, similarly to the operation of the check seal 10 in the above embodiment.

When the O-ring 24 moves to the large diameter D ₂ zone of the cylinder 1, since the O-ring outer diameter than the cylinder bore length D ₂ is small, a gap between them, just as the operation from the conventional Sutedanpa It is.

In the this embodiment, when the O-ring 24 is moved to _a portion diameter D from large diameter D ₂ parts of the cylinder 1, because its shape is round, to pass through the inclined surface is less smooth resistance Since it is possible, there is an advantage that the feeling of the opening and closing operation is smoother than the case where the check seal 10 is used.

〔The invention's effect〕

As described above, according to the stay damper of the present invention, a predetermined section having a small inner diameter is provided on the cylinder side, and a check seal function portion acting only on the section is provided on the piston rod side, so that a check can be performed during the extension stroke. The working fluid is opened between the small-diameter cylinder chamber closed by the seal function part and the other cylinder chamber with the piston part interposed therebetween while generating a constant differential pressure by an external force applied to the piston rod. Because it was configured as
First, the two-stage opening operation of the rear gate adopting this can be performed safely and securely by the function of the internal mechanism without the need for adjustment work by the user and the like, and the opening after the intermediate position when the door is opened. In the position, the degree of opening can be locked at any position.In particular, in arranging the check seal function part in the limited space in the cylinder, the cylinder side is reduced in diameter by a certain thickness. By doing so, a large amount of discharged liquid can be obtained by moving the check seal function section in this reduced diameter section, and thereby, the positioning accuracy of the intermediate stop position can be improved, and the effect is practical. It is extremely useful.

[Brief description of the drawings]

1 is a half longitudinal sectional view showing a main part of the damper of the present invention, FIG. 2 is a half longitudinal sectional view of a main part showing another embodiment of the damper of the present invention, and FIG. 3 is a valve configuration in the damper of the present invention. FIG. 4 is a longitudinal sectional side view showing another embodiment of the present invention, and FIG. 4 is a partially cutaway side view showing another embodiment of the check seal function portion in the damper of the present invention. 1 ... Cylinder, 2 ... Piston 3 ... Piston rod, 6 ... Diameter cylinder 10 ... Check seal, 13 ... Hollow passage

Claims (1)

(57) [Claims] An inner diameter of a predetermined section corresponding to a rear stage of a stroke of a piston rod in a cylinder is reduced to a small diameter, while the piston rod is located at a position corresponding to a distance corresponding to the predetermined section from a piston portion at a tip end thereof. A check seal function that acts only on the inner wall of the small-diameter cylinder is provided between the small-diameter cylinder chamber closed by the check-seal function and the other cylinder chamber sandwiching the piston during the expansion and contraction process. Wherein the working fluid is released while generating a constant differential pressure between the chambers by an external force applied to the piston rod.