JP3995361B2 - Oil lock structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in an oil lock structure that alleviates an impact when a front fork is compressed most.
[0002]
[Prior art and its problems]
The front fork mounted on the front wheel side of the motorcycle is set so as to avoid collision between the vehicle body side tube and the axle side tube at the time of the most compression, that is, to reduce the impact. Is often embodied in an oil lock structure.
[0003]
This oil lock structure is, for example, an oil that is held on the inner periphery of the lower end portion of the vehicle body side tube in which the oil lock piece disposed in a fixed state on the bottom portion of the axle side tube descends from above. It is set to fit on the inner periphery side of the lock collar.
[0004]
In addition, this oil lock structure allows the gap that appears between the oil lock piece and the oil lock collar to be oiled when the engagement between the oil lock piece and the oil lock collar is manifested at a high speed. The oil lock chamber is divided on the back side of the oil lock piece, etc. while the resistance at the time of passing is increased, that is, the throttle resistance is increased, and the lowering speed of the vehicle body side tube is suppressed, that is, the compression speed of the front fork is suppressed. It is supposed that the lowering of the vehicle body side tube, that is, the further compression of the front fork is forcibly prevented by the lock pressure standing on.
[0005]
Therefore, generally speaking, the oil lock structure composed of the oil lock piece and the oil lock collar can alleviate the impact at the time of the most compression in the front fork, while the front fork is in the most compressed state. There is a risk that a negative pressure sound will be generated when reversing from the extended state to the extended state.
[0006]
That is, in the above-described conventional oil lock structure, the oil lock piece is disposed in a fixed state at the bottom portion of the axle side tube, and the oil lock collar is fitted so as to cover the oil lock piece. .
[0007]
The oil lock chamber generates a lock pressure by preventing the oil flow through the gap, and prevents the front fork from being most compressed by the lock pressure.
[0008]
Accordingly, even when the front fork is reversed from the most compressed state to the extended state, the flow of oil through the gap between them, that is, the suction of oil into the oil lock chamber is prevented.
[0009]
Therefore, when the front fork is reversed and extended from the most compressed state, the oil lock chamber is in a negative pressure state, so that the oil is forcibly sucked from the outside, and as a result, the oil is sucked. Sound, that is, negative pressure sound is generated.
[0010]
Not only that, but when the front fork starts to reverse from the most compressed state to the extended state, negative pressure is generated in the oil lock chamber, so the front fork cannot start to be smoothly extended, that is, the responsiveness decreases. There is also a bug that is done.
[0011]
Therefore, in order to prevent the generation of the negative pressure sound, for example, there is a proposal that a check valve that allows the oil to be sucked while allowing the lock pressure to stand around the oil lock piece is arranged.
[0012]
However, in the proposal for distributing the check valve, there is a problem that the structure around the oil lock piece is complicated, and when the check valve is clogged with dust in the oil, a predetermined lock pressure is set. There is a risk that it will be impossible to stand up.
[0013]
The present invention has been developed in view of the above-described circumstances, and the object of the present invention is not to complicate the structure around the oil lock piece as well as to realize predetermined shock relaxation. An oil lock structure that is optimal for suppressing the generation of negative pressure noise is provided.
[0014]
[Means for Solving the Problems]
A vehicle body side tube is inserted into the axle side tube so that it can be moved in and out, a seat pipe is erected on the shaft core part of the axle side tube, and an urging force interposed between the seat pipe and the outer periphery of the lower end portion of the seat pipe A cylindrical oil lock piece urged downward by a spring is inserted, and an oil lock collar is held on the inner periphery of the lower end of the vehicle body side tube. In the oil lock structure of the front fork that is fitted to the outer periphery of the oil lock piece to reduce the impact, when the oil lock collar is fitted to the outer periphery of the oil lock piece during compression operation, it is partitioned behind the oil lock piece In addition, the pressure in the oil lock chamber isolated from the reservoir in the seat pipe is applied to the lower end surface of the oil lock piece. The oil lock piece is characterized in that so as to increase against the biasing spring.
[0015]
In this case, a through hole for generating a compression side damping force is formed in the seat pipe and a long hole penetrating in the diametrical direction is formed in the lower end portion of the seat pipe, and is fixed to the inner peripheral side of the oil lock piece in the diametrical direction. The inserted guide pin is inserted into the elongated hole so as to be movable up and down. A cylindrical slide member connected to the guide pin is inserted on the inner peripheral side of the seat pipe so as to be movable up and down, and when the slide member is moved up in conjunction with the guide pin, the upper end thereof is inserted into the through hole. It is preferable to make them close or interfere.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on the illustrated embodiment. Even in the oil lock structure according to the present invention, as in the case of the above-described conventional oil lock structure, the motorcycle is mounted on the front wheel side of the motorcycle. It is embodied in the front fork.
[0017]
It should be noted that, in each of the embodiments shown below, where the configuration is the same, the same reference numeral is assigned to each drawing, and detailed description thereof is omitted unless necessary.
[0018]
As shown in FIG. 1, in the front fork of the present invention, an inner tube 2 that is a vehicle body side tube is inserted into an outer tube 1 that is an axle side tube so that the seat tube 3 stands up and down on the axis of the axle side tube. A cylindrical oil lock piece urged in a downward direction by an urging spring 12 interposed between the seat pipe 3 and the outer periphery of the lower end portion of the seat pipe 3 is inserted, The oil lock collar 5 is held on the inner periphery of the lower end portion, and this oil lock collar 5 is fitted to the outer periphery of the oil lock piece 4 when the vehicle body side tube is lowered to alleviate the impact.
[0019]
In the present invention, as shown in FIG. 2 , when the oil lock collar 5 is fitted to the outer periphery of the oil lock piece 4 during the compression operation, the oil lock piece 4 is partitioned behind the oil lock piece 4 and in the seat pipe 3. The oil lock piece 4 is raised against the biasing spring 12 by acting on the lower end surface of the oil lock piece with the pressure in the oil lock chamber isolated from the reservoir R3.
[0020]
Further, a through hole 3b for generating a compression side damping force is formed in the seat pipe 3 and a long hole 3e penetrating in the diametrical direction is formed in the lower end portion of the seat pipe 3 so The guide pin 11 that is fixed toward the head is inserted into the elongated hole 43e so as to be movable up and down.
Also, A cylindrical slide member 16 connected to the guide pin 11 is inserted on the inner peripheral side of the seat pipe 3 so as to be movable up and down, and when the slide member 16 is raised in conjunction with the guide pin 11, its upper end is It is made to interfere with the said through-hole 3b.
[0021]
To explain a little, first, the outer tube 1 is not shown, but the lower end is connected to the axle of the front wheel of the motorcycle, and the inner tube 2 is also not shown, but the upper end is connected to the motorcycle body while the handle is Connected to the bracket to be fixed.
[0022]
Then, it is assumed that the inner tube 2 is inserted into the outer tube 1 so that it can protrude and retract, and at this time, the bearing 6 interposed on the outer periphery of the lower end of the inner tube 2 slides on the inner periphery of the outer tube 1 and slides. Sex is guaranteed.
[0023]
Next, the seat pipe 3 is screwed to the lower end diameter-reduced portion 3a of the tightening bolt 7 inserted from below into the shaft core portion of the bottom portion 1a of the outer tube 1 to Standing in a fixed state.
[0024]
As shown in FIG. 2, the seat pipe 3 passes through the lower end side, that is, above the upper end of the oil lock piece 4 to be described later, and communicates between the inner peripheral side and the outer peripheral side. And has a through hole 3b as an orifice that enables generation of a compression side damping force.
[0025]
Further, as shown in FIG. 3, the seat pipe 3 has an upper end side present on the inner peripheral side on the lower end side of the inner tube 2, and is interposed on the outer periphery of the upper end enlarged diameter portion 3 c under this state. The seal 8 that is in sliding contact with the inner periphery of the inner tube 2 blocks communication between the so-called upper side and the lower side of the upper end enlarged diameter portion 3c.
[0026]
Further, the seat pipe 3 is an orifice that penetrates the vicinity of the upper end, which is below the upper end enlarged diameter portion 3c, to allow communication between the inner peripheral side and the outer peripheral side, and to generate the extension side damping force. 3d.
[0027]
In addition, the seat pipe 3 urges the front fork to the extended side, that is, urges the lower end of the suspension spring 9 to urge the inner tube 2 in the direction of projecting the inner tube 2 from the outer tube 1. Carried at the top.
[0028]
Incidentally, the state shown in FIG. 3 is when the front fork is substantially in a fully extended state. At this time, the shock mitigation distributed between the upper end enlarged diameter portion 3c and the oil lock collar 5 described later is performed. The extension spring 10 for use is in a state close to the most contraction.
[0029]
As shown in FIG. 2, the oil lock piece 4 is slidably disposed on the outer periphery of the lower end portion of the seat pipe 3, and is interposed in a state in which the flow of oil between the oil pipes is prevented. A body portion 4a formed in a cylindrical shape with an appropriate thickness and an oil hole flange portion 4c 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.
[0031]
In addition, said oil hole collar part 4c forms said taper surface 4b so that thickness may become thin gradually as it becomes an upper end side.
[0032]
By the way, this oil lock piece 4 has a guide pin 11 that is disposed horizontally, that is, in a diametrical direction so as to be spanned around the main body portion 4a and is fixed to the inner peripheral side.
[0033]
And this guide pin 11 has penetrated the long hole 3e opened at the lower end part of the seat pipe 3 which the main-body part 4a of the oil lock piece 4 slidably contacts.
[0034]
Incidentally, the long hole 3e is opened along the axial direction of the seat pipe 3, and has a length that does not hinder the guide pin 11 when it rises in the long hole 3e. (See FIG. 4).
[0035]
Further, the lower end position of the long hole 3e is such that the lower end of the guide pin 11 is not in contact with the oil lock piece 4 when the oil lock piece 4 is lowered and seated on the bottom portion 1a of the outer tube 1. It is set (see FIG. 2).
[0036]
Of course, both ends of the guide pin 11 are set so as not to protrude from the outer periphery of the oil lock piece 4.
[0037]
On the other hand, the oil lock piece 4 is urged in the downward direction by an urging spring 12 interposed between the oil pipe and the seat pipe 3, and has a lower end as long as there is no action of a so-called back pressure, which will be described later. Is set to be maintained in a state of being seated on the bottom portion 1 a of the outer tube 1.
[0038]
At this time, the urging spring 12 is interposed on the outer periphery of the seat pipe 3, and the upper end is locked to a stopper ring 13 fitted on the outer periphery of the seat pipe 3.
[0039]
The oil lock piece 4 has an annular notch 4d on the inner periphery on the upper end side, and an urging spring in an annular gap (not shown) formed between the seat pipe 3 and the outer periphery. The end of the urging spring 12 is supported on a stepped portion (not shown) that forms the annular gap.
[0040]
The oil lock collar 5 is held on the inner periphery of the lower end portion of the inner tube 2 described above, but the upper and lower ends are formed in a substantially cylindrical shape by pressure deformation, and the lower end is the inner periphery of the lower end of the inner tube 2. The extension side damping valve 14 is provided on the inner periphery of the upper end portion.
[0041]
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.
[0042]
Incidentally, the above-described extension side damping valve 14 is disposed in the lowering direction by a non-return spring 15 (see FIG. 3) 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. Is maintained in a so-called seated state, that is, in a valve closed state.
[0043]
The extension side damping valve 14 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 14a 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 (see FIG. 3).
[0044]
Further, the extension side damping valve 14 has a notch 14b on the outer peripheral side on the upper end side (see FIG. 3), and when the extension side damping valve 14 is raised, the extension side damping valve 14 is below the extension side damping valve 14. Consideration is given so that the oil on the side can flow upward without stagnation.
[0045]
The extension side damping valve 14 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 14, and also the outer peripheral side of the seat pipe 3 The pressure side oil chamber R2 is defined below the expansion side damping valve 14, and at this time, the inner peripheral side of the seat pipe 3 is a so-called reservoir chamber R3.
[0046]
Therefore, the front fork formed as described above is expanded and contracted as described below while being mounted on the motorcycle.
[0047]
That is, first, when the motorcycle on which the rider rides travels on a flat road which is a good road, the inner tube 2 protrudes from the outer tube 1 and the extension side oil chamber R1 is contracted, and this extension side oil is contracted. Oil from the chamber R1 passes through the orifice 3d and flows out into the reservoir chamber R3.
[0048]
At this time, when the oil passes through the orifice 3d, an expansion side damping force is generated, and in this embodiment, a gap flow between the inner periphery of the damping valve 14 and the outer periphery of the seat pipe 3 is obtained. Is allowed , and the damping force on the extension side due to this gap flow is also generated.
[0049]
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.
[0050]
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 passes through the extension side damping valve 14 from the pressure side oil chamber R2. While opening and flowing in, an amount of oil corresponding to the amount of immersion of the inner tube 2 passes through the pressure side oil chamber R2 through the through hole 3b and flows out into the reservoir chamber R3.
[0051]
And the damping force of the compression side generate | occur | produces because oil passes through the through-hole 3b. Note that no damping force is generated when the damping valve 14 is opened.
[0052]
Furthermore, when a motorcycle runs on a rough road and the front fork expands and contracts at a high speed, it operates as follows.
[0053]
First, at the time of extension 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 10, and the extension spring 10 contracts, Impact during extension is reduced.
[0054]
Next, at the time of compression 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. Mating.
[0055]
At this time, at the start of fitting, although not shown in the drawing, oil from the bottom portion 1a side is stored in the reservoir chamber R3 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 suppressed by the squeezing resistance caused by oil flowing out to the side and passing through the gap.
[0056]
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 lock chamber R prevents further compression of the front fork.
[0057]
Incidentally, when the fitting speed is extremely low, the above-mentioned throttle resistance is not large, so that the lock pressure in the oil lock chamber R is low, and the oil lock piece 4 is maintained in the seated state on the bottom 1a by the biasing spring 12. The
[0058]
When the front fork operates at a high speed to the maximum compression state, the lock pressure in the oil lock chamber R is increased, and this high pressure acts on the lower end surface of the oil lock piece 4. As a result, as shown in FIG. 4, the oil lock piece 4 rises against the biasing spring 12.
[0059]
Therefore, in the present invention, when the oil lock piece 4 is raised , the engagement stroke with the oil lock collar 5 is increased by the amount of the oil lock piece 4 being raised, so that the oil lock collar 5 and the oil lock piece are increased. Even if it does not require the accuracy control of the fitting gap with 4, it can have an impact relaxation effect effectively.
[0060]
On the other hand, when the front fork is reversed and extended from the most compressed state, the oil lock piece 4 is quickly lowered due to the action of the biasing spring 12, and therefore, the negative pressure phenomenon in the oil lock chamber R is suppressed. As a result, the generation of negative pressure noise can be suppressed, and the front fork can be quickly extended.
[0061]
Incidentally, the front fork of the embodiment shown in the figure has a slide member 16 that is housed on the inner peripheral side of the seat pipe 3 and whose lower end is held by the guide pin 11.
[0062]
That is, the slide member 16 is formed in a cylindrical shape having an appropriate length, and the outer periphery thereof is in sliding contact with the inner periphery of the seat pipe 3, and in the illustrated embodiment, the upper end is opened in the seat pipe 3. Near the through hole 3b as an orifice, the lower end is connected to the guide pin 11.
[0063]
Incidentally, in the illustrated embodiment, the upper end of the slide member 16 is adjacent to the through hole 3b. However, instead of this, the upper end of the slide member 16 interferes with the through hole 3b. It may be configured as follows.
[0064]
Further, in the illustrated embodiment, the two through holes 3b are so-called two at the same level. However, instead of this, a plurality (two) of the through holes 3b may be arranged in the vertical direction, although not shown. .
[0065]
Therefore, in the oil lock structure having the slide member 16 described above, when the oil lock piece 4 rises, the slide member 16 rises due to the rise of the guide pin 11 of the oil lock piece 4. The opening area of the through hole 3b adjacent to the upper end of the slide member 16 is reduced, and the compression side damping force generated by the through hole 3b is increased.
[0066]
As a result, at the time of the most compression of the front fork, in addition to the so-called oil lock effect, the compression side damping becomes higher, so that more effective impact mitigation can be achieved.
[0067]
From this, in this type of conventional oil lock structure, when the oil lock piece is formed and assembled under high precision control so that it can exhibit the throttle resistance as set with the oil lock collar In comparison with the oil lock structure according to the present invention, even if the throttle resistance is slightly reduced, that is, even if high accuracy control is not required for gap management to obtain a predetermined throttle resistance, As a result, the desired effective impact can be achieved.
[0068]
Therefore, in the oil lock structure according to the present invention, compared with the conventional oil lock structure, the oil lock piece 4 is not required to be sophisticated in accuracy control with respect to the oil lock collar 5, and is thus predetermined. This is advantageous in that the oil lock effect can be obtained.
[0069]
As described above, in order to improve the oil lock effect, the slide member 16 is arranged in accordance with the rise of the oil lock piece 4 and is arranged on the inner peripheral side of the seat pipe 3 to increase the compression side damping force. Instead of this, although not shown, the above-mentioned slide member 16 is lengthened, the lower end of the suspension spring 9 is carried by the upper end of the elongated slide member 16, and the lower end of the suspension spring 9 is raised by raising the slide member 16. The spring force may be set so as to increase.
[0070]
Incidentally, in this case, even if the elongated slide member 16 is set so as to reduce the opening area of the through hole 3b described above at the intermediate portion, it may be set so as to increase the compression side damping force. good.
[0071]
【The invention's effect】
As described above, according to the present invention, when the front fork is near the maximum compression at high speed, the oil passes through the gap 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 throttle resistance, and at the time of maximum compression, further compression of the front fork is prevented by the lock pressure in the oil lock chamber partitioned behind the oil lock piece.
[0072]
At this time, the oil lock piece, because the seat pipe Te Fuku' is movable up and down, will be elevated in locking pressure in the oil lock chamber, the oil lock piece amount corresponding to the increase, the oil lock collar There is an advantage that the fitting stroke becomes large.
[0073]
When the front fork compressed at high speed reverses and extends, the oil lock piece that has been lifted can be quickly lowered due to the action of the urging spring, resulting in excellent responsiveness. There are advantages that the negative pressure phenomenon in the lock chamber can be suppressed and the generation of negative pressure noise can be suppressed, and that the front fork can be quickly extended.
[0074]
Further, in the invention of claim 2, the upper end is adjacent to a through hole as an orifice that is accommodated on the inner peripheral side of the seat pipe and the lower end is connected to the guide pin while allowing the generation of the compression side damping force. Alternatively, since the slide member interferes , when the oil lock piece rises, the slide member rises due to the rise of the guide pin, and the opening area in the above-described through hole is narrowed, so that the compression side damping force Will be higher.
[0075]
As a result, at the time of the most compression of the front fork, in addition to the so-called oil lock effect, the compression side damping force is also increased, so that more effective impact mitigation can be achieved.
[0076]
Therefore, in this type of conventional oil lock structure, compared to the case where the oil lock piece is formed and assembled under high precision control so as to exhibit the set-up resistance with the oil lock collar. In the oil lock structure according to the present invention, even if the throttle resistance is slightly reduced, that is, even if high precision control is not required for gap management to obtain a predetermined throttle resistance , as a result , It can be said that a desired oil lock effect can be obtained.
[0077]
Therefore, in the oil lock structure having the above-described slide member, the oil lock piece has a high degree of precision control between the oil lock collar and the oil lock piece as compared with the conventional oil lock structure. This is advantageous in that the oil lock effect can be obtained.
[0078]
As a result, according to the present invention, it is possible to suppress the generation of negative pressure sound without complicating the structure around the oil lock piece, as well as to realize predetermined impact relaxation, and its versatility. It is most suitable to expect improvement.
[Brief description of the drawings]
FIG. 1 is a partial sectional front view showing a front fork according to an embodiment of the present invention in a substantially extended state.
2 is an enlarged longitudinal sectional view showing a bottom portion of an axle side tube in the front fork of FIG. 1. FIG.
3 is an enlarged longitudinal sectional view showing a lower end portion of a vehicle body side tube in the front fork of FIG. 1; FIG.
4 is a view showing an oil lock structure when the front fork in FIG. 1 is in the most compressed state, similarly to FIG. 2;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Outer tube as an axle side tube 2 Inner tube as a vehicle body side tube 3 Seat pipe 3a Lower end diameter-reduced part 3b Through hole as an orifice 3c Upper end diameter-enlarged part 3d Orifice 3e, 4d Long hole 4 Oil lock piece 4a Main body part 4b Tapered surface 4c Oil hole collar 5 Oil lock collar 6 Bearing 7 Clamping bolt 8 Seal 9 Suspension spring 10 Stretching spring 11 Guide pin 12 Biasing spring 13 Stopper ring 14 Stretching side damping valve 14a Annular groove 14b Notch 15 Non-return Spring 16 Slide member R Oil lock chamber R1 Extension side oil chamber R2 Pressure side oil chamber R3 Reservoir chamber

Claims (2)

A vehicle body side tube is inserted into the axle side tube so that it can be moved in and out. A cylindrical oil lock piece urged downward by a spring is inserted, and an oil lock collar is held on the inner periphery of the lower end of the vehicle body side tube. In the oil lock structure of the front fork that is fitted to the outer periphery of the oil lock piece to reduce the impact, the oil lock collar is partitioned behind the oil lock piece when the oil lock collar is fitted to the outer periphery of the oil lock piece during compression operation The pressure in the oil lock chamber isolated from the reservoir in the seat pipe is applied to the lower end surface of the oil lock piece. Oil lock structure the oil lock piece in the front fork, characterized in that the raise against the biasing spring. A guide pin that forms a through hole that generates a compression-side damping force in the seat pipe and a long hole that penetrates in the diametrical direction at the lower end of the seat pipe, and is fixed to the inner peripheral side of the oil lock piece in the diametrical direction. Is inserted into the slot so as to be movable up and down, and A cylindrical slide member connected to the guide pin is inserted on the inner peripheral side of the seat pipe so as to be movable up and down, and when the slide member is raised in conjunction with the guide pin, its upper end interferes with the through hole. 2. The oil lock structure for a front fork according to claim 1 .

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