JP4417522B2 - Oil lock structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an oil lock structure, and more particularly to an improvement of an oil lock structure in a front fork.
[0002]
[Prior art and its problems]
There have been various proposals for an oil lock structure that reduces the impact of the front fork during the most compression operation. However, when the front fork is set upside down and with a built-in damper, the oil lock structure is a damper. An oil lock case disposed in the vicinity of the head portion of the cylinder constituting the cylinder and oil lock pieces arranged on the rod side constituting the damper may be provided.
[0003]
At this time, in this oil lock structure, the oil lock pieces are inserted into the oil lock case when the front fork is fully compressed. At this time, the oil lock case is inserted between the oil lock case and the oil lock pieces. The compression resistance of the front fork is slowed down by the squeezing resistance caused by the oil passing through the appearing gap, and the desired impact relaxation is realized.
[0004]
On the other hand, in a front fork with a built-in damper, an amount of oil corresponding to the so-called rod volume is discharged from the damper to a reservoir outside the damper during the compression operation. May be introduced, leading to a problem that air is mixed into the oil.
[0005]
Incidentally, it is well known that when air is mixed in oil, inconveniences such as the occurrence of a stable damping force in the damper cannot be expected.
[0006]
Therefore, there is a proposal to store free pistons in the reservoir for suppressing disturbance of the oil level, but the oil lock case and oil lock pieces constituting the oil lock structure described above are also distributed in the reservoir. .
[0007]
Therefore, if free pistons are arranged in the reservoir in addition to this oil lock structure, it can be said that it is conceptually simply combined, but it is not easy to make it concrete, and no such proposal has actually been made. is the current situation.
[0008]
The present invention has been developed in view of such a current situation, and the object of the present invention is not only to realize predetermined shock relaxation, but also to prevent oil level disturbance in the reservoir. It is an object to provide an oil lock structure that can generate a stable damping force in a damper and is optimal for expecting an improvement in versatility.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the means of the present invention includes a vehicle body side tube, an axle side tube that is inserted into and retracted into the vehicle body side tube, a damper provided in an axial center portion of the axle side tube, an axle side A suspension spring that is disposed in the tube and constantly urges the vehicle body side tube in the extending direction; and a reservoir chamber provided between the damper and the vehicle body side tube, and the damper stands from the bottom of the axle side tube. And a rod whose upper end is fixed to the upper end of the vehicle body side tube while being freely inserted into and retracted into the cylinder. In the damper built-in front fork that replenishes the cylinder 4 from the reservoir chamber with oil for the rod withdrawal volume that flows out into the
A guide member fixed on the cylinder head, an oil lock case interposed on the outer periphery of the guide member via a check seal, and an oil lock case provided on the outer periphery of the rod. The oil lock case is opposed to the inner periphery of the axle-side tube so that the lower end of the suspension spring is separated from the lower reservoir chamber and the upper oil reservoir chamber. A partition portion to be supported; the guide member standing from a head portion of the cylinder; an axial passage formed on an inner peripheral side of the cylinder portion and opening into the oil reservoir; and the cylinder is formed in the body portion of the parts and a communication passage for communicating the outer peripheral side of the flow path and the tubular portion, the oil lock piece during compression of the oil lock invade within the oil lock case In addition, the oil in the cylinder is caused to flow into the reservoir chamber to increase the pressure in the reservoir chamber, and when the internal pressure in the reservoir chamber becomes excessive, the oil lock case is raised above the communication hole against the suspension spring. However, the oil in the reservoir chamber flows out to the oil reservoir chamber through the communication hole and the oil passage.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the front fork of the present invention includes an outer tube 1 that is a vehicle body side tube, an inner tube 2 that is an axle side tube inserted into and retracted into the outer tube 1, and an axial core portion of the inner tube 2. A damper provided in the inner tube 2, a suspension spring 3 disposed in the inner tube 2 to constantly urge the outer tube 1 in the extending direction, and a reservoir chamber R provided between the damper and the inner tube 2. The damper 4 has a cylinder 4 standing up from the bottom of the inner tube 2 and a rod 5 whose upper end is fixed to the upper end of the outer tube 1 while being freely inserted into and retracted into the cylinder 4. The excess rod entry volume oil flows into the reservoir chamber R, and the rod retraction volume oil that is insufficient in the damper when extended From the chamber R is damper visceral front fork to replenish to the Shirin'nda 4.
In the present invention, the guide member 8 fixed on the head portion 4a of the cylinder 4, the oil lock case 6 interposed on the outer periphery of the guide member 8 via the check seal 10 so as to be movable up and down, and the rod The oil lock piece 7 is provided on the outer circumference of the oil lock case 6 and faces the inside of the oil lock case 6. The oil lock case 6 is slidably contacted with the inner circumference of the inner tube 2 on the outer circumference, and the reservoir chamber R below. A partition wall portion 6b that supports the lower end of the suspension spring 3 while separating the upper oil sump chamber is provided, and the guide member 8 includes a cylinder portion 8b that rises from a head portion 4a of the cylinder, and a tube portion 8b of the cylinder portion 8b. A channel 8c that is formed on the inner peripheral side and extends in the axial direction that opens into the oil sump chamber, and a channel 8c that is formed in the body portion of the cylindrical portion 8b communicates the channel 8c and the outer peripheral side of the cylindrical portion 8b. Communication path 8 It is equipped with a door.
As a result, in the present invention, the oil lock piece 7 enters the oil lock case 6 to effect oil lock during compression, and the oil in the cylinder 4 is caused to flow into the reservoir chamber R so as to enter the reservoir chamber R. When the internal pressure in the reservoir chamber R becomes excessive, the oil in the reservoir chamber R is raised above the communication hole 8d against the suspension spring 3 while the oil lock case 6 is raised above the communication hole. The oil is allowed to flow into the oil reservoir chamber through 8d and the oil passage 8c.
This will be described in more detail below.
[0014]
That is, first, as shown in FIG. 1, the front fork is set to an inverted type in which an inner tube 2 that is an axle-side tube is inserted into an outer tube 1 that is a vehicle-side tube so as to be able to protrude and retract in the presence of a suspension spring 3. In addition, a damper built-in type having a damper at the shaft core is set.
[0015]
At this time, although not shown, it is assumed that the upper end of the outer tube 1 is connected to the handle in the motorcycle under the presence of the bracket, and the lower end of the inner tube 2 is connected to the axle of the front wheel in the motorcycle. The upper end of the suspension spring 3 is connected to or locked with the upper end of the outer tube 1 with an appropriate member interposed therebetween.
[0016]
Although not shown in the drawings, the damper, that is, the cylinder 4 constituting the damper is assumed to be erected on the shaft core portion of the inner tube 2 while being fixed to the bottom portion of the inner tube 2. An upper end of the rod 5 is fixedly connected to an upper end of the outer tube 1 while being able to project and retract with respect to the cylinder 4.
[0017]
Therefore, in this front fork, a predetermined damping force is generated by the damper during expansion and contraction at a normal stroke that is not the maximum extension and compression, and at this time, an excess of the rod enters the damper. The volume of oil flows out into the reservoir chamber R on the outer peripheral side of the cylinder 4, and the rod withdrawal volume of oil that becomes insufficient with the damper is supplied from the reservoir chamber R into the cylinder 4.
[0018]
Next, as shown in FIG. 2, the oil lock structure includes an oil lock case 6 disposed in the vicinity of the head portion 4 a in the cylinder 4 and an oil lock piece 7 disposed on the rod 5. It is said to have.
[0019]
At this time, the oil lock case 6 is interposed on the outer periphery of the guide member 8 that allows the rod 5 to be inserted while being connected to the head portion 4a.
[0020]
The oil lock case 6 has an oil hole flange 6a formed in a cylindrical shape that allows the oil lock piece 7 to be fitted on the upper end side, and a partition wall portion 6b formed in a thick flange shape on the outer periphery. It is said that it will be protruding.
[0021]
At this time, the partition wall portion 6b is formed so that the outer periphery is slidably contacted with the inner periphery of the inner tube 2 under the distribution of the seal 9 while supporting the lower end of the suspension spring 3 at the upper end. The above-described reservoir chamber R and an oil reservoir chamber (not shown) above the partition wall 6b are defined. In this oil reservoir chamber, a gas chamber G with the oil level O as a soot is formed.
[0022]
Thus, since the partition wall 6b in the oil lock case 6 partitions the reservoir chamber R and the oil reservoir chamber, even if the oil from the damper is expelled to the reservoir chamber R, the oil reservoir chamber The oil level O is not disturbed, and the trouble that air is mixed into the oil due to the disturbance of the oil level O can be avoided in advance.
[0023]
Further, the oil lock case 6 has a check seal 10 that is in sliding contact with the outer periphery of the guide member 8 on the inner periphery on the lower end side. At this time, the check seal 10 includes the oil hole flange 6a. Is allowed to flow to the lower end side, but the reverse flow of oil from the reservoir chamber R is prevented from flowing into the oil reservoir chamber, that is, the oil pressure in the reservoir chamber R is the oil lock case. 6 is set so as not to be released to the oil sump chamber via the inner peripheral side.
[0024]
The guide member 8 has a base portion 8a which is a lower end flange portion which is connected to a head portion 4a of the cylinder 4 in a fixed state. The guide member 8 includes an inner portion of a cylinder portion 8b which is a main body portion where the oil lock case 6 is interposed on the outer periphery. A flow path 8c is formed between the circumference and the outer circumference of the rod 5, and is opened so as to penetrate the wall thickness in the middle part of the cylindrical part 8b. It is assumed that a communication hole 8d that allows communication with the communication hole 8d is provided.
[0025]
Therefore, according to the guide member 8 and the oil lock case 6 interposed in the guide member 8, the oil pressure of the reservoir chamber R acts on the lower end of the oil lock case 6 and the oil lock case 6 is suspended. The hydraulic pressure of the reservoir chamber R can be released to the oil reservoir chamber when the fixed stroke is increased by overcoming the biasing force of the spring 3 and the communication hole 8d is opened on the lower end side of the oil lock case 6. become.
[0026]
On the other hand, the oil lock piece 7 is assumed to be held in a state that can move up and down on the outer periphery side of the holder 11 interposed on the outer periphery of the rod 5. A cylindrical gap 7a is formed as a flow path, and a notch passage 7b communicating with the cylindrical gap 7a is provided at the lower end.
[0027]
Further, the holder 11 is screwed onto a nut 13 that is held in a fixed state in advance under the arrangement of the stopper ring 12 on the outer periphery of the rod 5, and at this time, the oil lock piece 7 is set flat. Similarly, the upper end of the nut 13 is opposed to the lower end of the nut 13 which is also set to be flat.
[0028]
Therefore, according to the oil lock piece 7 and the oil lock case 6 described above, when the oil lock piece 7 is fitted into the oil lock case 6 as shown in FIG. While the upper end is in close contact with the lower end of the nut 13 and blocks the flow of oil between the nut 13 and the annular shape between the outer periphery of the oil lock piece 7 and the inner periphery of the oil hole flange 6a in the oil lock case 6. A gap S will appear.
[0029]
As a result, the oil that is confined to the inner peripheral side of the oil hole flange 6a in the oil lock case 6 below the oil lock piece 7 is oil that becomes the upper side door of the oil lock piece 7 through the annular gap S. Escape to the reservoir chamber, and the lowering speed of the rod 5 holding the oil lock piece 7 is slowed down by the throttle resistance at that time, and the impact relaxation is executed.
[0030]
In the oil lock case 6, the partition wall 6b carries the lower end of the suspension spring 3, that is, the partition wall 6b is pressed against the reservoir chamber R side by the urging force of the suspension spring 3. As long as the reservoir chamber R is always pressurized, the occurrence of an aeration phenomenon is prevented when the damper is expanded and contracted, and a stable damping force can be generated.
[0031]
In addition, since the oil from the damper is discharged to the reservoir chamber R during the compression operation of the front fork, the oil in the reservoir chamber R does not flow into the oil reservoir chamber due to the arrangement of the check seal 10, that is, Since the reservoir chamber R is not released, the pressure is increased in accordance with the compression stroke of the front fork. Therefore, the generation of the stable damping force in the damper is more effectively realized.
[0032]
When the oil pressure in the reservoir chamber R rises, the oil lock case 6 is raised along with the guide member 8 by the oil pressure in the reservoir chamber R. Therefore, during the maximum compression operation of the front fork, this oil that rises. The oil lock piece 7 is inserted into the lock case 6, so that the flow rate per unit time of the oil flowing through the annular gap S to the oil reservoir chamber side increases, and a more effective impact mitigation effect. Will be obtained.
[0033]
Incidentally, when the oil pressure in the reservoir chamber R becomes excessive, the oil lock case 6 rises next to the guide member 8, and the reservoir is provided in the guide member 8 via the open communication hole 8 d and the flow path 8 c. The hydraulic pressure in the chamber R is released to the oil sump chamber.
[0034]
As a result, the hydraulic pressure in the reservoir chamber R, that is, the hydraulic pressure on the damper side is properly maintained, and the burden on the seal (not shown and not shown) on the damper side can be reduced, and the durability of the seal on the damper side can be improved. The damper function can be permanently secured without being unnecessarily lowered.
[0035]
Incidentally, the oil lock piece 7 described above is prevented from lowering by the stopper ring 12 interposed on the outer periphery of the rod 5, but the rise is related to the lower end of the spring guide 15 under the intervention of the O-ring 14. It is said that it will be stopped by being stopped.
[0036]
Although not shown, the spring guide 15 has an upper end connected to the upper end side of the rod 5 and functions to prevent the suspension spring 3 from buckling.
[0037]
【The invention's effect】
As described above, according to the present invention, since the partition wall portion in the oil lock case partitions the reservoir chamber and the oil reservoir chamber, even if the oil from the damper is discharged into the reservoir chamber vigorously, In addition, the oil level, which is the boundary surface between the oil reservoir and the gas chamber, is not disturbed, and it is possible to avoid in advance the problem that air is mixed into the oil due to the disturbance of the oil surface.
[0038]
Further, in this invention, the partition wall portion in the oil lock case carries the lower end of the suspension spring, that is, the partition wall portion is pressed against the reservoir chamber side by the urging force of the suspension spring. The reservoir chamber is always kept in a pressurized state. Therefore, the occurrence of an aeration phenomenon is prevented when the damper is expanded and contracted, and a stable damping force can be generated.
[0039]
Not only that, when the front fork is compressed, oil from the damper is discharged to the reservoir chamber, and the oil in the reservoir chamber is not flown into the oil reservoir chamber due to the arrangement of the check seal, that is, not released. Therefore, the pressure in the reservoir chamber is increased according to the compression stroke of the front fork. Therefore, the generation of the stable damping force in the damper is more effectively realized.
[0040]
When the hydraulic pressure in the reservoir chamber rises, the oil lock case is raised by the hydraulic pressure in the reservoir chamber. Therefore, when the front fork is most compressed, the oil lock piece is inserted into the rising oil lock case. Therefore, the flow rate per unit time of the oil flowing through the annular gap appearing between the oil lock case and the oil lock piece and flowing to the oil reservoir chamber increases, and a more effective impact mitigation effect is achieved. Will be obtained.
[0041]
Also, when the oil pressure in the reservoir chamber is excessive, the oil lock case rises next to the guide member, and the oil pressure in the reservoir chamber is increased via the open communication hole and the cylindrical gap. Since the oil pressure is released to the oil sump chamber, the hydraulic pressure on the damper side can be maintained properly, the burden on the seal on the damper side can be reduced, and the durability of the seal on the damper side can be reduced unnecessarily. Therefore, the damper function can be guaranteed permanently.
[0042]
As a result, according to the present invention, it is possible not only to realize a predetermined impact relaxation, but also to prevent the oil surface from being disturbed in the reservoir and to generate a stable damping force in the damper, and to improve its versatility. Ideal for expecting improvements.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional front view showing a front fork equipped with an oil lock structure according to the present invention, partially broken away.
FIG. 2 is a partial longitudinal sectional view showing an enlarged operation state of an oil lock structure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Outer tube as a vehicle body side tube 2 Inner tube as an axle side tube 3 Suspension spring 4 Cylinder 4a which constitutes a damper 5 Rod which constitutes a damper 6 Oil lock case 6a Oil hole flange 6b Bulkhead 7 Oil lock piece 7a Cylindrical gap 7b Notch passage 8 Guide member 8a Base portion 8b Tube portion 8c Flow path 8d Communication hole 9 Seal 10 Check seal 11 Holder 12 Stopper ring 13 Nut 14 O-ring 15 Spring guide G also serving as a spacer Gas chamber O Oil level R Reservoir Chamber S Annular gap

Claims (1)

A vehicle body side tube (1) , an axle side tube (2) inserted into and retracted into the vehicle body side tube (1) , a damper provided in an axial center portion of the axle side tube (2) , an axle side tube ( 2) A suspension spring (3) disposed in the vehicle and constantly biasing the vehicle body side tube (1) in the extending direction, and a reservoir chamber (R) provided between the damper and the vehicle body side tube (2). A cylinder (4) in which the damper stands from the bottom of the axle tube (2) , and the upper end is fixed to the upper end of the vehicle body tube (1) while being inserted into and retracted into the cylinder (4) . having a rod (5), the rod intrusion volume of the oil has become surplus in the damper to flow out into the reservoir chamber (R) at the time of compression, the rod exiting the volume of the oil shortage in the damper during extension auxiliary reservoir chamber from (R) to the Shirin'nda (4) in In the damper visceral type front fork,
A guide member (8) fixed on the head portion (4a ) of the cylinder (4) , and an oil lock case (not shown ) interposed on the outer periphery of the guide member (8) via a check seal (10) so as to move up and down. 6) and an oil lock piece (7) provided on the outer periphery of the rod (5) and facing the oil lock case (6) , and the oil lock case (6) is disposed on the axle side tube on the outer periphery. A partition wall (6b) supporting the lower end of the suspension spring (3) while separating the lower reservoir chamber (R) and the upper oil reservoir chamber in sliding contact with the inner periphery of (2) ; The guide member (8) is a cylindrical portion (8b) that stands up from the head portion (4a) of the cylinder, and an axial flow path that is formed on the inner peripheral side of the cylindrical portion (8b) and opens to the oil reservoir chamber. and (8c), formed in the body portion of the tubular portion (8b) Comprising a communication path and (8d) for communicating the outer peripheral side of the flow path (8c) and the tubular portion (8b), the oil lock piece (7) to penetrate within the oil lock case (6) during compression the oil in the cylinder (4) causes twist oil lock to flow into the reservoir chamber (R) boosts the reservoir chamber (R) Te, the internal pressure of the reservoir chamber (R) becomes excessive When the oil lock case (6) is raised above the communication hole (8d) against the suspension spring (3) , the oil in the reservoir chamber (R ) is supplied to the communication hole (8d) and the oil passage (8c ). oil lock structure in a front fork, characterized in that) through to flow out to the oil reservoir chamber.

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