JP4078011B2 - Impact relaxation structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in an impact mitigation structure that is mounted on a front fork mounted on the front wheel side of a motorcycle and that mitigates an impact during a maximum compression operation of the front fork.
[0002]
[Prior art]
Conventionally, a front fork mounted on the front wheel side of a motorcycle has an impact mitigation structure for mitigating an impact during the most compression operation. On the other hand, for example, a shock absorbing structure having a new configuration shown in FIG. 6 can be proposed.
[0003]
That is, as shown in FIG. 6 and FIG. 7, this shock relaxation structure enables the height position of the oil lock piece 4 to be changed by operating the operation unit 20, and when the oil lock piece 4 is raised, for example, The spring force of the suspension spring 13 (see FIG. 9) is strengthened, so that it is possible to effectively reduce the impact during the maximum compression operation of the front fork.
[0004]
In brief, the oil lock piece 4 is first moved up and down to the outer peripheral side of the lower end portion of the seat pipe 3 fixedly arranged on the shaft core portion of the axle side tube 1. As shown in FIG. 8, it is arranged so that it can be raised by the lock pressure standing in the oil lock chamber R partitioned on the back side.
[0005]
On the other hand, as shown in FIG. 9, the oil lock collar 5 is held on the inner periphery of the lower end portion of the vehicle body side tube 2 that appears and disappears in the axle side tube 1. The oil lock piece 4 is fitted on the inner peripheral side (see FIG. 8).
[0006]
Therefore, according to this shock mitigation structure, the oil lock piece 4 is fitted into the oil lock collar 5 during the most compression operation in which the vehicle body side tube 2 is immersed in the axle side tube 1 with a large stroke, In other words, oil from the oil lock chamber R partitioned behind the lock piece 4 passes through a gap where the oil appears between the two, so that it escapes.
[0007]
As a result, the speed at which the vehicle body side tube 2 is immersed in the axle side tube 1 is slowed by the flow resistance generated by the oil passing through the gap, and further, the vehicle body side is driven by the lock pressure standing in the oil lock chamber R. Further immersion of the tube 2 into the axle side tube 1, that is, further compression of the front fork is prevented, so that the impact caused by so-called bottoming in the front fork can be mitigated.
[0008]
By the way, in this shock mitigation structure, the oil lock piece 4 is moved up and down by the operation to the operation unit 20 disposed on the outer periphery of the bottom portion 1a in the axle side tube 1 through the elevating piston 23. (See FIG. 7).
[0009]
Therefore, when the oil lock piece 4 is raised by the operation of the operation unit 20, the compression speed of the front fork is reduced and the impact is reduced compared to the case where the oil lock piece 4 is not raised. In other words, it is expressed with a short compression stroke.
[0010]
  On the other hand, in this impact mitigation structure, the seat pipe 3 has an adjustment pipe 14 whose upper end extends upward on the inner peripheral side of the seat pipe 3, and the seat pipe while holding the lower end of the adjustment pipe 14 at the intermediate portion.3It is assumed that both ends of the guide pin 10 pass through a vertically extending guide hole 3e opened at the lower end of the guide pin 10 and both ends of the guide pin 10 are connected to the oil lock piece 4 by press fitting. Yes.
[0011]
And as this adjustment pipe 14 is shown in FIG. 9, it is supposed that the lower end of the suspension spring 13 is carry | supported by the spring receiving part 14a which is an upper end part.
[0012]
Therefore, when the oil lock piece 4 is raised, the guide pin 10 is raised integrally with the oil lock piece 4, whereby the lower end of the suspension spring 13 is raised, and the spring force of the suspension spring 13 is increased. It will be strengthened.
[0013]
As a result, the spring force of the suspension spring 13 is strengthened, so that the reduction of the compression speed and the impact relaxation in the above-described front fork are more effectively realized.
[0014]
[Problems to be solved by the invention]
However, it may be pointed out that the newly proposed impact mitigation structure described above cannot permanently secure the desired impact mitigation function.
[0015]
That is, a recent front fork is designed to be as light as possible as one measure for improving the operability of the handle in a motorcycle. For example, the oil lock piece 4 is made of aluminum. There are many cases.
[0016]
On the other hand, considering the function of the guide pin 10, iron having higher rigidity than aluminum is often used.
[0017]
Therefore, even if this guide pin 10, that is, both ends of the guide pin 10 are press-fitted and connected to the oil lock piece 4, the holding force at that time, that is, the large holding force in the oil lock piece 4 is expected to be exhibited. There is a fear that it cannot be done.
[0018]
As a result, the guide pin 10 is not connected to the oil lock piece 4 in a fixed state as set, and can move in the radial direction which is the left-right direction in the drawing. The end portion of the pin 10 protrudes to the outer peripheral side of the oil lock piece 4 and interferes with the oil lock collar 5. Therefore, it is possible to cause the above-described proposed shock relief structure to permanently exhibit a predetermined impact relief function. There is a fear that it can not be expected.
[0019]
The present invention has been made in view of the above-described circumstances, and the object of the invention is not only that the predetermined impact relaxation function can be exhibited in multiple stages, but also the permanent release of the impact relaxation function. It is possible to provide an impact mitigation structure that is optimal for expecting improved versatility to the front fork.
[0020]
[Means for Solving the Problems]
  In order to achieve the above-mentioned object, the structure of the impact mitigation structure according to the present invention can basically be raised and lowered to the outer peripheral side of the lower end portion of the seat pipe arranged in a fixed state on the shaft core portion of the axle side tube. And an oil lock piece that rises with a lock pressure standing in an oil lock chamber that is partitioned on the back side of the oil lock chamber, and is held on the inner periphery of the lower end of the vehicle body side tube, In the impact mitigating structure having an oil lock collar to which the oil lock piece is fitted, the oil lock piece can be moved up and down by operating the operation portion disposed on the outer periphery of the bottom portion of the axle tube.The seat pipe is opened at the lower end portion and has a guide hole extending in the vertical direction, and the adjustment pipe is disposed on the shaft core portion so that the adjustment pipe can be moved up and down. The guide pin allows both ends to be inserted into the guide holes that are opened in the seat pipe and both ends areLinked to the cylinder located between the outer periphery of the lower end of the seat pipe and the inner periphery of the oil lock pieceLet meSuppose.
[0021]
In the configuration described above, more specifically, the adjustment pipe carries the lower end of the suspension spring in which the spring receiving portion as the upper end portion urges the vehicle body side tube in the direction of extracting the vehicle body side tube from the axle side tube. Alternatively, the diaphragm resistance part is provided on the outer periphery in the vicinity of the upper end, and the diaphragm resistance part is opened downstream of the orifice that is opened in the seat pipe and generates the extension side damping force.
[0022]
In addition, the operation unit has an elevating piston that is adjacent to the lower end of the oil lock piece and is set to be movable up and down, and when the elevating piston is raised by the supply of external force such as fluid pressure, the oil lock piece is Suppose that it is raised.
[0023]
Furthermore, it is preferable that a valve for preventing the generation of negative pressure noise is disposed around the oil lock piece.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
In the following, the present invention will be described based on the illustrated embodiment. Even in the impact mitigation structure according to the present invention, the structure is basically the same as the above-described proposed impact mitigation structure. .
[0025]
Therefore, in the following description, the features that are characteristic of the present invention will be described while explaining the points that have not been fully described in the above-mentioned proposal. In the embodiment shown in the drawings, the same reference numerals are assigned to the same parts, and detailed description thereof is omitted unless necessary.
[0026]
That is, first, in the impact relaxation structure according to the present invention, as shown in FIG. 1, a cylinder in which both ends of the guide pin 10 are arranged between the outer periphery of the lower end portion of the seat pipe 3 and the inner periphery of the oil lock piece 4. It is said that it is connected to the body 16.
[0027]
As a result, the oil lock piece 4 functions as a stopper facing both ends of the guide pin 10, and therefore both ends of the guide pin 10 cannot protrude to the outer peripheral side of the oil lock piece 4, and as a result, the guide pin 10 Thus, the situation in which the both ends of the oil protrude toward the outer peripheral side of the oil lock piece 4 and interfere with the oil lock collar 5 is not caused, and the predetermined impact mitigation function can be made permanent.
[0028]
At this time, it is assumed that the intermediate portion of the guide pin 10 carries the lower end of the adjustment pipe 14 that is disposed on the shaft core portion that is the inner peripheral side of the seat pipe 3 and that the upper end side extends upward, under the intervention of the seat member 15. Yes.
[0029]
Incidentally, the adjustment pipe 14 carries the lower end of the suspension spring 13 by the spring receiving portion 14a which is the upper end portion as in the above-described proposal. A diaphragm resistance portion 14c that is present on the downstream side of the generated orifice 3d may be provided in the vicinity of the upper end thereof (see FIG. 9).
[0030]
When the adjustment pipe 14 has the throttle resistance portion 14c, the throttle resistance portion 14c adjusts the opening degree of the orifice 3d when the guide pin 10 is lifted, and the extension side damping force having a different magnitude is applied. Will be generated.
[0031]
At this time, the adjustment pipe 14 forms a gap as an oil flow path between the adjustment pipe 14 and the seat member 15 to maintain the gap, that is, as a spacer for centering the adjustment pipe 14. It is functioning.
[0032]
Therefore, in the impact mitigating structure having the adjustment pipe 14, as shown in FIGS. 2 and 3, when the oil lock piece 5 is raised, the cylinder body 16 that rises together with the oil lock piece 4 is provided. The adjustment pipe 14 rises as the guide pin 10 is raised, and the lower end of the suspension spring 13 carried on the upper end of the adjustment pipe 14 is raised, so that the spring force of the suspension spring 13 is increased.
[0033]
On the other hand, the seat pipe 3 is screwed to the lower end threaded portion 3a of the tightening nut 7 inserted from below into the shaft core portion of the bottom portion 1a of the axle side tube 1, and is attached to the shaft core portion of the outer tube 1. It is supposed to stand in a fixed state.
[0034]
At this time, the guide hole 3e that is opened in the seat pipe 3 and passes through both end portions of the guide pin 10 is formed in the shape of a long hole along the axial direction of the seat pipe 3, and the guide pin 10 is the guide pin 10. When rising in the hole 3e, the length is set so as not to hinder this.
[0035]
The lower end position of the guide hole 3e is set so as not to contact the lower end of the guide pin 10 when the oil lock piece 4 is lowered and seated on the bottom portion 1a. .
[0036]
Further, the seat pipe 3 penetrates there in the vicinity of the lower end portion, that is, in the vicinity of the upper end of the oil lock piece 4 described later, and enables communication between the inner peripheral side and the outer peripheral side. It has a through hole 3b that enables generation of a compression side damping force when passing through.
[0037]
  And as for this seat pipe 3, the upper end side is present in the inner peripheral side of the lower end side of the inner tube 2, and the upper end enlarged diameter part 3c under this state(See Figure 9)Seal 8 interposed on the outer periphery of(See Figure 9)Slidably contact the inner periphery of the inner tube 2 to block communication between the so-called upper side and the lower side of the upper end enlarged diameter portion 3c.Yes.
[0038]
  By the way, the lower side of the upper end enlarged diameter portion 3c is connected to the reservoir chamber R3 which is the inner peripheral side of the seat pipe 3 through the orifice 3d opened in the vicinity of the upper end of the seat pipe 3.Communicating (see Figure 9).
[0039]
The axle-side tube 1 having the seat pipe 3 at the shaft core portion is not shown, but the lower end is connected to the axle of the front wheel of the motorcycle. Although not shown in the figure, the vehicle body side tube 2 is connected to a bracket for fixing the handle while the upper end portion is connected to the vehicle body of the motorcycle.
[0040]
Further, the oil lock piece 4 is slidably interposed on the outer periphery of the cylindrical body 16 interposed on the outer periphery of the lower end portion of the seat pipe 3 described above, and has the same thickness and an appropriate length. A body portion 4a on the lower end side formed in a cylindrical shape, and an oil hole flange portion 4c on the upper end side integrally connected to the upper end of the body portion 4a and extending upward and having an outer peripheral surface as a tapered surface 4b. Have.
[0041]
At this time, in the oil lock piece 4, the lower end of the main body 4 a forms a pressure receiving surface in the oil lock piece 4, and the area is set smaller than the pressure receiving area on the inner tube 2 side. Yes.
[0042]
At this time, the oil lock piece 4 has a flange 4d on the inner periphery of the lower end of the main body portion 4a, and a cylindrical body 16 described later is carried on the flange 4d.
[0043]
Incidentally, the oil hole flange 4c is formed with the tapered surface 4b so as to be gradually thinned toward the upper end side.
[0044]
On the other hand, the operation unit 20 that enables the oil lock piece 4 to be moved up and down is disposed on the outer periphery of the bottom portion 1a of the axle-side tube 1 and is moved up and down adjacent to the lower end of the oil lock piece 4. An elevating piston 23 that can be set is provided, and when the elevating piston 23 is raised by an external force such as fluid pressure, the oil lock piece 4 is raised (see FIG. 2).
[0045]
To explain a little, in the illustrated case, the operation unit 20 advances the piston 22 by rotating the operation dial 21, and the advance of the piston 22 causes the oil in the oil storage chamber R4 to flow into the pressure chamber R5. The oil lock piece 4 is raised by raising the elevating piston 23 that partitions the pressure chamber R5 by inflow.
[0046]
At this time, the communication passage 1c that communicates between the oil storage chamber R4 and the pressure chamber R5 is set so as to exhibit a throttling effect. Therefore, the throttling effect prevents leakage that is interposed in the piston 22. The seal 22a does not have to be a high-pressure seal, and the durability of the seal 22a can be improved.
[0047]
The operation unit 20 is configured in a mode in which an external force is mechanically transmitted without using the fluid pressure, although not shown, instead of the mode of using the fluid pressure including a so-called pump as illustrated. It may be.
[0048]
When using hydraulic pressure, it is also possible to use oil filled in the front fork. When using mechanical means, the overall configuration is simpler than when hydraulic pressure is used. It will be possible.
[0049]
Whereas the oil lock piece 4 is configured as described above, the oil lock collar 5 is held on the inner periphery of the lower end portion of the vehicle body side tube 2, but the upper and lower ends are almost deformed under pressure. It is formed in a cylindrical shape, and it is assumed that the lower end is held by caulking and fixing to the inner periphery of the lower end of the vehicle body side tube 2, and has an extension side damping valve 11 on the inner peripheral side of the upper end portion (see FIG. 6).
[0050]
In the oil lock collar 5, the inner diameter of the intermediate portion serving as the main body portion is matched with the outer diameter of the main body portion 4 a in the oil lock piece 4.
[0051]
Incidentally, the expansion side damping valve 11 is urged in a downward direction by a non-return spring 12 disposed on the upper end side while being retractably movable on the inner peripheral side of the upper end portion of the oil lock collar 5 so-called seating. In other words, the valve is kept closed.
[0052]
The extension side damping valve 11 has a gap (not shown and not shown) that allows oil leakage on the inner periphery on the lower end side that is in sliding contact with the outer periphery of the seat pipe 3, and faces the outer periphery of the seat pipe 3. An annular groove 11 a communicating with the lower gap is provided on the inner periphery on the upper end side, and an annular gap (not shown) is formed between the outer periphery of the seat pipe 3.
[0053]
The extension side damping valve 11 has a notch 11b on the outer peripheral side on the upper end side. When the extension side damping valve 11 is raised, the oil on the lower side of the extension side damping valve 11 is upward. It is designed so that it can flow smoothly to the side.
[0054]
The extension side damping valve 11 is arranged so that an extension side oil chamber R1 is defined on the outer peripheral side of the seat pipe 3 and above the extension side damping valve 11, and also on the outer peripheral side of the seat pipe 3. In this case, it is assumed that the compression side oil chamber R2 is defined below the extension side damping valve 11, and at this time, the inner peripheral side of the seat pipe 3 is defined as the reservoir chamber R3.
[0055]
The cylindrical body 16 is set so that the inner periphery is in sliding contact with the outer periphery of the lower end portion of the seat pipe 3 and the outer periphery is in sliding contact with the inner periphery of the oil lock piece 4. Both ends of the guide pin 10 are connected to the drilled mounting hole 16a.
[0056]
At this time, both ends of the guide pin 10 are opposed to the inner periphery of the oil lock piece 4, and the oil lock piece 4 functions as a so-called stopper, so it is not necessary to be press-fitted into the mounting hole 16a, so-called loose. Even if the guide pin 10 is inserted, both ends of the guide pin 10 do not protrude to the outer peripheral side of the oil lock piece 4.
[0057]
Incidentally, the cylinder body 16 is arranged in a state of being placed on the flange 4d formed on the inner periphery of the lower end of the oil lock piece 4 described above.
[0058]
In view of the above, compared to the case where it is necessary to consider that both ends of the guide pin 10 cannot protrude from the outer periphery of the oil lock piece 4 in the above-described new proposal, that is, both ends of the guide pin 10 are oil-locked. Compared to the case where it is necessary to be connected to the piece 4 in a fixed state, the two ends of the guide pin 10 are connected to the cylinder 16 on the condition that the cylinder 16 has a large holding force. Therefore, it is advantageous in that precise processing is not required for forming the mounting hole 16a in the cylindrical body 16.
[0059]
As a result, even if the guide pin 10 is made of iron, not only the oil lock piece but also the cylinder 16 can be made of aluminum, and there is a concern that the weight may be increased even if the number of parts that are the cylinder 16 increases. It will not be necessary.
[0060]
Therefore, in the impact mitigation structure according to the present invention formed as described above while having the above-described configuration of the new proposal, it operates as follows when the front fork is compressed with a large stroke. It will be.
[0061]
That is, when the front fork is compressed with a large stroke, the oil lock collar 5 held on the inner periphery of the lower end portion of the inner tube 1 covers the oil lock piece 4 disposed on the bottom portion 1 a of the outer tube 1. Will be fitted.
[0062]
At this time, at the start of fitting, oil from the bottom portion 1a flows out to the reservoir chamber R3 side through a gap formed between the inner periphery of the oil lock collar 5 and the outer periphery of the oil lock piece 4. The compression speed of the front fork is slowed down by the throttle resistance caused by the oil passing through the gap.
[0063]
On the other hand, the oil lock chamber R is defined in the bottom portion 1a of the outer tube 1 by the inner tube 2 that holds the oil lock collar 5 due to the generation of the drawing resistance caused by the oil passing through the gap. The lock pressure in the oil lock chamber R prevents further compression of the front fork.
[0064]
At this time, as shown in FIG. 3, the oil lock piece 4 rises along with the seat pipe 3 due to the lock pressure in the oil lock chamber R. At this time, the inner tube is increased by the amount that the oil lock piece 4 is raised. It can be said that the compression stroke of 2, that is, the compression stroke of the front fork becomes large.
[0065]
Incidentally, when the oil lock piece 5 is raised, the adjustment pipe 14 is raised by the rise of the guide pin 10 of the cylindrical body 16 that rises together with the oil lock piece 4, and a spring receiving portion at the upper end of the adjustment pipe 14. It goes without saying that the lower end of the suspension spring 13 carried on the 14a is raised and its spring force becomes stronger.
[0066]
In view of the above, it is compared with a case in which a conventional impact mitigation structure is formed and assembled under high precision control so that the diaphragm resistance as set between the oil lock piece 4 and the oil lock collar 5 can be exhibited. In the impact relaxation structure according to the above-described new proposal and the impact relaxation structure according to the present invention, even if the aperture resistance is slightly reduced, that is, the gap management for obtaining a predetermined aperture resistance is highly accurate. Even if management is not required, the spring force can be increased, resulting in effective impact mitigation.
[0067]
Therefore, in the impact mitigating structure according to the above-mentioned new proposal and the impact mitigating structure in the present invention, the accuracy of the oil lock piece 4 with the oil lock collar 5 is approximately compared with the conventional impact mitigating structure. This is advantageous in that a high degree of management is not required and a predetermined oil lock effect can be obtained.
[0068]
Incidentally, in the impact mitigating structure according to the above-mentioned new proposal and the impact mitigating structure in the present invention, when the front fork is reversed and extended from the most compressed state, the oil lock piece 4 is attached to the seat pipe 3. Since it can be raised and lowered, the oil lock piece 4 that has been lifted can be quickly lowered and has excellent responsiveness. Therefore, the negative pressure phenomenon in the oil lock chamber R can be suppressed and negative pressure noise can be suppressed. The generation can be suppressed and the quick extension operation of the front fork can be realized.
[0069]
By the way, in order to more reliably prevent the generation of the negative pressure sound at the time of reversing to the extension operation, it is preferable to provide a valve for preventing the generation of the negative pressure sound having an appropriate configuration around the oil lock piece 4.
[0070]
The valve is formed in a so-called check valve structure, for example, as shown in FIG. 4. First, the valve is cut out at the inner periphery of the upper end of the lifting piston 23 in the operation unit 20. It is assumed that a valve housing groove 23b having a step 23a is formed.
[0071]
Next, while the annular leaf valve 17 is placed on the step 23a, an annular disk 18 is formed on the annular leaf valve 17 so that the annular leaf valve 17 is formed on the outer periphery while being formed to be almost similar to the valve housing groove 23b. It is assumed that the oil lock piece 4 is supported by the annular disk 18.
[0072]
As a result, as shown in FIG. 5, when the front fork reverses from the most compressed state and extends, the oil lock piece 4 is seated on the annular disk 18, that is, on the lifting piston 23. Even if no gap is formed between the lower end of the oil lock piece 4 and the upper end of the lifting piston 23 to allow the passage of oil, the annular leaf valve 17 rises to allow the above oil flow, The generation of negative pressure sound can be reliably suppressed.
[0073]
Further, in the impact mitigating structure according to the above-described new proposal and the impact mitigating structure of the present invention, when the front fork is reversed from the most compressed state and extends, the urging force of the suspension spring 13 is finally oil. Since it acts on the lock piece 4, the oil lock piece 4 that has been lifted can be lowered more quickly, and the responsiveness is further improved.
[0074]
When the front fork extends with a large stroke, the upper end of the oil lock collar 5 held on the inner periphery of the lower end portion of the inner tube 1 comes into contact with the extension spring 9, and the extension spring 9 contracts. By doing so, the impact at the time of the maximum extension is relieved.
[0075]
Further, in the impact mitigation structure according to the above-mentioned new proposal and the impact mitigation structure of the present invention, the operation is performed as follows when the rider is on board, that is, when the front fork is extended and contracted in a so-called 1G state. become.
[0076]
That is, first, when the motorcycle travels on a flat road that is a good road, the inner tube 2 protrudes from the outer tube 1 to contract the expansion side oil chamber R1, and the oil from the extension side oil chamber R1 is discharged. It passes through the orifice 3d and flows out to the reservoir chamber R3.
[0077]
At this time, the oil passes through the orifice 3d to generate a damping force on the expansion side. In this embodiment, the gap flow between the inner periphery of the damping valve 11 and the outer periphery of the seat pipe 3 is achieved. Is allowed, and a damping force on the extension side due to the gap flow is also generated.
[0078]
Incidentally, at this time, an insufficient amount of oil in the pressure side oil chamber R2 is supplied from the reservoir chamber R3 through the through hole 3b.
[0079]
Next, at the time of compression when traveling on a flat road, the inner tube 2 is immersed in the outer tube 1, and at this time, the oil that is insufficient in the extension side oil chamber R1 opens the damping valve 11 from the pressure side oil chamber R2. The amount of oil corresponding to the amount of immersion of the inner tube 2 passes through the through hole 3b and flows out to the reservoir chamber R3.
[0080]
And the damping force of the compression side generate | occur | produces because oil passes the through-hole 3b. Note that no damping force is generated when the damping valve 11 is opened.
[0081]
【The invention's effect】
  As described above, in the present invention, both ends of the guide pin are arranged between the outer periphery of the lower end portion of the seat pipe and the inner periphery of the oil lock piece.On the cylinderConnectedBecauseAs a stopper where the oil lock piece faces both ends of the guide pinFunctionTherefore, both ends of the guide pin cannot protrude to the outer peripheral side of the oil lock piece, and as a result, both ends of the guide pin protrude to the outer peripheral side of the oil lock piece and interfere with the oil lock collar.not, Permanent of the specified shock mitigation functionNaMaking it possibleCan do.
[0082]
Therefore, in the present invention, compared to the case where it is necessary to consider that both ends of the guide pin cannot protrude from the outer periphery of the oil lock piece in the above-described new proposal, that is, both ends of the guide pin are Compared to the case where it is necessary to be connected to the oil lock piece in a fixed state, the cylinder body is required to have a large holding force in connecting the both ends of the guide pin to the cylinder body. Therefore, it is advantageous in that precise processing is not required for forming the mounting hole in the cylinder, and even if the guide pin is made of iron, not only the oil lock piece but also the cylinder is made of aluminum. Therefore, even if the number of parts that are cylinders increases, there is no need to worry about an unreasonable increase in weight.
[0083]
In addition, in the present invention including the above-mentioned new proposal, when the front fork is compressed most, when it is in the vicinity of the most compressed, it is formed between the inner periphery of the oil lock collar and the outer periphery of the oil lock piece. The compression speed of the front fork is suppressed by the squeezing resistance caused by the oil passing through the gap, and at the time of the most compression, the lock pressure in the oil lock chamber partitioned behind the oil lock piece exceeds that of the front fork. Compression will be prevented.
[0084]
At this time, since the oil lock piece can be moved up and down next to the seat pipe, the oil lock piece is raised by the lock pressure in the oil lock chamber, and the compression stroke of the inner tube is increased by this oil lock piece. That is, there is an advantage that the compression stroke of the front fork becomes large.
[0085]
When the most compressed front fork reverses and expands, the oil lock piece that has been lifted along with the seat pipe can quickly descend and has excellent responsiveness. The pressure phenomenon can be suppressed and generation of negative pressure sound can be suppressed, and the front fork can be quickly extended.
[0086]
Then, when the oil lock piece is in the state where the oil lock piece is raised by the operation of the operation unit, if the front fork is in the most compressed state, the oil lock piece is further raised, and therefore the oil lock piece There is an advantage that the stroke at the time of the maximum compression of the front fork can be increased by that amount compared to the case where is not raised in advance.
[0087]
Also, a guide pin that is accommodated on the inner peripheral side of the seat pipe so as to be movable up and down, and that the upper end carries the lower end of the suspension spring that urges the vehicle body side tube in the extending direction, while the lower end is connected to the oil lock piece. In the case of having an adjustment pipe that is locked to the guide pin, the guide pin is also raised by the rise of the oil lock piece. Therefore, the adjustment pipe is raised and the lower end of the suspension spring is raised, and the spring of this suspension spring is raised. The power will be increased.
[0088]
As a result, at the time of maximum compression of the front fork, in addition to the so-called oil lock effect, the spring force of the suspension spring increases, so that it is possible to more effectively reduce the impact.
[0089]
Therefore, in the conventional shock mitigation structure, this is compared to the case where the oil lock piece is formed and assembled under high precision control so as to exhibit the set resistance against the oil lock collar. In the oil lock structure according to the present invention, even if the squeezing resistance is slightly reduced, that is, even if high precision management is not required for clearance management for obtaining a predetermined squeezing resistance, the spring force is increased. As a result, it can be said that the desired impact can be reduced.
[0090]
Therefore, in the impact mitigating structure having the adjustment pipe described above, the oil lock piece has a high degree of precision control with respect to the oil lock collar and is not required as compared with the conventional impact mitigating structure. This is advantageous in that the oil lock effect can be obtained.
[0091]
Further, in the impact mitigating structure having the adjusting pipe, when the front fork is reversed and extended from the most compressed state, the urging force of the suspension spring acts on the oil lock piece via the adjusting pipe. For this reason, the oil lock piece comes out of the oil lock collar more quickly, and can be extended more quickly.
[0092]
Furthermore, when the adjustment pipe has a throttle resistance portion on the outer periphery in the vicinity of the upper end, and this throttle resistance portion is opened in the seat pipe and is present downstream of the orifice that generates the extension side damping force, When the throttle resistance portion is raised as the adjustment pipe rises, it is possible to apply a throttle resistance downstream of the orifice and increase the extension-side damping force generated by the orifice.
[0093]
Therefore, when the oil lock piece is raised by the operation of the operation part, the restriction resistance part rises due to the rise of the adjustment pipe and the restriction resistance is given downstream of the orifice. Thus, the extension side damping force at the time of extension operation of the front fork can be increased, and more effective impact relaxation at the time of maximum extension can be achieved.
[0094]
And when the oil lock piece is raised by operation of the operation part, the extension side damping force generated by the oil passing through the orifice when the front fork extends is increased, and the spring force in the suspension spring is increased. Therefore, it becomes possible to increase the compression side damping force and the extension side damping force, that is, the absorbed energy when the front fork is extended and contracted, and to make the riding comfort in the motorcycle so-called hard.
As a result, according to the present invention, it is possible not only to realize effective shock mitigation at the time of the most compression of the front fork in multiple stages, but also to make it possible to permanently exhibit a predetermined shock mitigation function. Ideal for expecting improved versatility.
[Brief description of the drawings]
FIG. 1 is a partial longitudinal sectional view showing an oil lock piece side in an impact relaxation structure according to an embodiment of the present invention.
FIG. 2 is a partial longitudinal sectional view showing, in an enlarged manner, a state where an oil lock piece in FIG. 1 is raised by an operation of an operation unit.
3 is a view similar to FIG. 2 showing a state in which an oil lock collar is fitted so as to cover the oil lock piece in FIG. 1. FIG.
FIG. 4 is a partial longitudinal sectional view showing an oil lock piece side in a half-mounted state in an impact mitigating structure according to another embodiment.
5 is a view similar to FIG. 4 showing a state in which the check valve is opened under the state where the oil lock piece in FIG. 4 is raised by operation of the operation unit.
FIG. 6 is a view showing an impact relaxation structure proposed prior to the present invention in the same manner as FIG. 1;
7 is a view similar to FIG. 6 showing a state in which the oil lock piece in FIG. 6 is raised by the sub operation.
8 is a view similar to FIG. 6 showing a state in which the oil lock case is fitted over the oil lock piece in FIG.
FIG. 9 is a partial longitudinal sectional view showing a state in which the upper end side of the seat pipe is present on the inner peripheral side of the vehicle body side tube.
[Explanation of symbols]
1 Axle tube
1a Bottom part
1c Communication path
2 Body side tube
3 Seat pipe
3a Lower end screwing part
3b Through hole as orifice
3c Upper end enlarged diameter part
3d orifice
3e Guide hole
4 Oil lock piece
4a Body
4b Tapered surface
4c Oil hole collar
4d flange
5 Oil lock collar
6 Bearing
7 Tightening nut
8 Seal
9 Extension spring
10 Guide pin
11 Damping valve
11a annular groove
11b Notch
12 Non-retan spring
13 Suspension spring
14 Adjustment pipe
14a Spring receiving part
14b Aperture resistance section
15 Sheet material
16 cylinder
16a Mounting hole
17 Annular leaf valve
18 annular disc
20 Operation unit
21 Operation dial
22 piston
23 Lifting piston
23a steps
23b Valve receiving groove
R Oil lock chamber
R1 Extension side oil chamber
R2 pressure side oil chamber
R3 reservoir chamber
R4 oil storage room
R5 pressure chamber

Claims (1)

An oil lock that is arranged to be movable up and down on the outer peripheral side of the lower end portion of the seat pipe arranged in a fixed state on the shaft core portion of the axle side tube, and rises by a lock pressure standing in an oil lock chamber partitioned behind the seat lock. In an impact mitigation structure having an oil lock collar that has a piece and is held on the inner periphery of the lower end portion of the vehicle body side tube and fits the oil lock piece on the inner periphery side when the lowermost part is lowered, The piece can be moved up and down by an operation to the operation portion arranged at the bottom portion of the axle side tube , and the seat pipe is opened at the lower end portion and has a guide hole extending in the vertical direction, and the adjustment pipe at the shaft core portion. The adjustment pipe is supported on the middle part of the guide pin that extends in the lateral direction, and the guide pin is inserted into the guide hole that opens both ends of the seat pipe. Cushioning structure characterized by comprising by interlocking a tubular body that Zaisa distribution between the inner periphery of the outer peripheral and the oil lock piece of the lower end portion of both ends in the seat pipe with to

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