WO2019082610A1 - Front fork - Google Patents

Abstract

The invention relates to a front fork (F) comprising: a cylinder (3); a rod (5), which is inserted with freedom of movement into the cylinder (3); and a rod guide (6), which slidably supports the rod (5) and which is fitted to the inner circumference of the cylinder (3), the front end portion of the cylinder (3) projecting from the guide of the cylinder (3). rod (6) serving as a bearing housing such as a lock housing (3c).

Description

Front fork

The present invention relates to an improvement of a front fork.

Conventionally, the front fork has an impact reducing mechanism for reducing the impact at the time of the last contraction. For example, a hydraulic pressure lock member such as an oil lock member, a cushion rubber or the like is used as the impact relaxation mechanism at the time of the last contraction.

Specifically, as disclosed in paragraphs 0021, 0022, and 0026 of JPH 06-4442U, the oil lock member includes an oil lock case connected to a cylinder housed in the front fork, and expansion and contraction of the front fork. And an oil lock piece attached to the outer periphery of the rod entering and exiting the cylinder. Then, when the front fork approaches the fully contracted state, the oil lock piece intrudes into the oil lock case and resists the flow of liquid flowing out of the oil lock case to reduce the contraction speed of the front fork. .

When using a cushion rubber, the cushion rubber is attached to the outer periphery of the rod as disclosed in JPH11-117983A. Then, when the front fork approaches the fully contracted state, the cushion rubber elastically deforms and exerts an elastic force against the deformation to reduce the contraction speed of the front fork. Furthermore, when the outer periphery of the elastically deformed cushion rubber is brought into contact with the rubber case connected to the cylinder, the rubber case can limit the deformation in the radial direction of the cushion rubber, and the force against contraction can be increased.

Assuming that the cushion case is a case that is fixed to the cylinder side and used to mitigate the shock at the time of the maximum contraction, such as these oil lock cases and rubber cases, such a cushion case A single cylinder head is configured integrally with a movably supported rod guide. And a cushion case and a rod guide are connected with a cylinder by screwing the said cylinder head with a cylinder.

As in the prior art, when one part called a cylinder head is provided with the functions of both the cushion case and the rod guide, the number of parts, as compared with the case where the cushion case and the rod guide are separately formed and attached to the cylinder, Assembling work can be facilitated by reducing the number of assembling steps.

However, if the cylinder head has both the function of the cushion case and the rod guide, it is necessary to form in the cylinder head a portion having the shape necessary to perform each function. Further, it is also necessary to secure a fitting length for slidably supporting the rod, for example, in a portion which functions as a rod guide, for performing the functions of the cushion case and the rod guide. For this reason, the shape of the cylinder head becomes large and complicated, which increases the cost.

Then, this invention aims at provision of the front fork which solves such a problem and can reduce cost.

In the front fork of the present invention, a rod guide for slidably supporting the rod is attached to the inner periphery of the cylinder, and the tip portion of the cylinder protruding from the rod guide is a cushion case.

According to the said structure, a cushion case and a rod guide can be formed separately, the shape of each component can be simplified, and the cost of each component can be reduced. In addition, even if the cost of each part is reduced, the cushion case is a part of the cylinder, and the number of parts and the number of assembling steps do not increase. As a result, the effect of reducing the cost of parts is not diminished and the cost of the front fork can be reduced.

FIG. 1 is a front view partially showing a front fork according to an embodiment of the present invention. FIG. 2 is a longitudinal sectional view showing a first modified example of the front fork according to the embodiment of the present invention and showing a part of the front fork according to the modified example. FIG. 3 is a longitudinal sectional view showing a second modified example of the front fork according to the embodiment of the present invention, and showing a part of the front fork according to the modified example.

Hereinafter, a front fork according to an embodiment of the present invention will be described with reference to the drawings. The same reference numerals as in the several figures indicate the same or corresponding parts.

A front fork F according to an embodiment of the present invention shown in FIG. 1 is a suspension system for suspending the front wheel of a straddle-type vehicle. In the following description, the upper and lower sides of the front fork F attached to the vehicle will be referred to as “upper” and “lower” of the front fork F unless otherwise specified.

The front fork F is housed in a telescopic tube member T configured to have an outer tube 1 and an inner tube 2 slidably inserted in the outer tube 1, and the tube member T. A damper D and a suspension spring S are provided.

The tube member T is an inverted type, and is disposed so that the outer tube 1 faces the upper side (vehicle body side) and the inner tube 2 faces the lower side (wheel side). That is, in the present embodiment, the outer tube 1 is a vehicle-side tube, and the inner tube is a wheel-side tube.

Outer tube 1 is connected to the vehicle body of the vehicle via a vehicle body side bracket (not shown). On the other hand, the inner tube 2 is connected to the axle of the front wheel via the wheel side bracket 20. Thus, the front fork F is interposed between the vehicle body and the axle. When the front wheel vibrates up and down, for example, when the vehicle travels on a rough road surface, the inner tube 2 enters and exits the outer tube 1 and the front fork F expands and contracts.

The tube member T may be an upright type, and the outer tube 1 may be a wheel side tube and the inner tube 2 may be a vehicle side tube. Further, a straddle-type vehicle on which the front fork F is mounted refers to all types of vehicles on which a rider rides in a posture that straddles a heel, and includes a motorcycle (including a scooter), a tricycle, and the like. The front fork F according to the present invention may be used in any straddle-type vehicle.

Subsequently, the upper end of the outer tube 1 is closed with a cap 10. The lower end of the inner tube 2 is closed by the wheel side bracket 20. Furthermore, the seal member 11 is closed between the outer tube 1 and the inner tube 2.

Thus, the inside of the tube member T is a sealed space, and the damper D is accommodated inside the tube member T. In addition, a liquid storage chamber R is formed between the tube member T and the damper D, and a liquid such as hydraulic oil is stored in the liquid storage chamber R, and a gas is enclosed above the liquid surface. It is done. The suspension spring S is accommodated in the liquid storage chamber R.

The damper D includes a cylinder 3 for containing liquid, a piston 4 slidably inserted in the cylinder 3, a rod 5 having one end connected to the piston 4 and the other end projecting out of the cylinder 3, and a cylinder An annular rod guide 6 is fixed to the inner periphery of a position spaced a predetermined distance from the tip of the side where the rod 5 projects in 3 and slidably supports the rod 5.

Moreover, the damper D is an upright type, and is disposed with the rod 5 protruding out of the cylinder 3 facing the upper side (the vehicle body side) of the cylinder 3. The rod 5 is connected to the outer tube 1 via the cap 10, and the cylinder 3 is connected to the inner tube 2.

Thus, the damper D is interposed between the outer tube 1 and the inner tube 2. Then, when the front fork F expands and contracts, the rod 5 moves in and out of the cylinder 3 and the damper D expands and contracts, and the piston 4 moves up and down in the cylinder 3.

The upper opening of the cylinder 3 is closed by a rod guide 6. A liquid chamber filled with a liquid is formed in the cylinder 3 below the rod guide 6, and the liquid chamber is an extension side chamber L 1 on the upper side (rod 5 side) of the piston 4, It is divided into a pressure side chamber L2 on the lower side (the piston 4 side).

The piston 4 is formed with a piston passage (not shown) communicating the expansion side chamber L1 and the pressure side chamber L2. The pressure side chamber L2 can communicate with the liquid reservoir R via a bottom passage (not shown).

Then, when the front fork F expands and contracts and the rod 5 moves in and out of the cylinder 3 and the piston 4 moves up and down in the cylinder, the liquid moves between the expansion side chamber L1 and the pressure side chamber L2 through the piston passage. The liquid equivalent to 5 volumes of the rod entering and exiting the cylinder 3 moves between the pressure side chamber L2 and the liquid reservoir R through the bottom passage.

Further, the damper D is provided with a damping element such as a valve, an orifice, a choke or the like that resists the flow of liquid generated when the front fork F is expanded or contracted. For this reason, when the front fork F expands and contracts, the damper D exerts the main damping force resulting from the resistance of the damping element to suppress the expansion and contraction movement of the front fork F.

The configuration of the damper D is not limited to the above, and can be changed as appropriate. For example, the configuration of the passage that communicates the chambers such as the expansion side chamber L1, the pressure side chamber L2, and the liquid storage chamber R can be appropriately changed. Furthermore, the damper D may be inverted, and the rod 5 may be protruded downward from the cylinder 3. Such a change is made when the tube member T is inverted or upright. It is possible without limitation.

Further, in the present embodiment, the damper D is a single rod type, and the liquid storage chamber R functions as a reservoir for compensating the volume of the rod 5 entering and exiting the cylinder 3. However, an inflatable and contractible air chamber may be formed in the cylinder 3 using a free piston, a bladder and the like, and volume compensation of the rod 5 entering and exiting the cylinder 3 may be performed in the air chamber. Furthermore, the damper D may be a double-rod type, and the rods may protrude from the both sides of the piston 4 to the outside of the cylinder 3. In this case, it is not necessary to make volume compensation of the rod entering and exiting the cylinder 3.

Further, in the present embodiment, the cylinder 3, the rod 5 and the rod guide 6 are members constituting the damper D which is a hydraulic damper that gives resistance to the flow of liquid to generate a damping force. It may be utilized besides a hydraulic pressure damper. In this case, for example, the piston passage, the bottom passage, and the damping element are eliminated, and the suspension spring accommodated in the cylinder 3 is compressed by the rod 5, the cylinder 3, the rod 5, the rod guide 6, and the suspension spring The device may be configured.

Subsequently, the rod guide 6 is annular, and an annular groove 6a is formed on the outer periphery along the circumferential direction. Then, in a state where the rod guide 6 is inserted into the cylinder 3, the portion of the cylinder 3 opposed to the annular groove 6a is crimped to protrude to the inner peripheral side, and the portion (hereinafter referred to as the caulking portion 3a) is an annular groove Fit in 6a. Then, the rod guide 6 is held on the inner periphery of the cylinder 3 and does not move in the axial direction with respect to the cylinder 3.

The cylinder 3 is crimped to attach the rod guide 6 to the inner periphery of the cylinder 3, and the caulking portion 3a may be circumferentially formed in the cylinder 3 in order to reliably maintain such an attached state of the rod guide 6. Preferably, three or four places are formed at intervals. However, the number of caulking parts 3a can be changed suitably.

When the caulking portion 3a is fitted in the annular groove 6a formed on the outer periphery of the rod guide 6, when forming the caulking portion 3a in the cylinder 3 by caulking, the circumferential direction of the cylinder 3 and the rod guide 6 It can eliminate the need for alignment. However, it goes without saying that the shape of the portion in which the caulking portion 3a is fitted can be changed as appropriate, and the method of fixing the rod guide 6 is not limited to caulking.

Further, an annular bush 60 in sliding contact with the outer periphery of the rod 5 is fitted on the inner periphery of the rod guide 6. That is, in the present embodiment, the rod guide 6 slidably supports the rod 5 via the bush 60. However, the rod 5 may be in sliding contact with the inner periphery of the rod guide 6 directly.

Subsequently, a spring bearing 7 is fitted to the tip of the cylinder 3 projecting upward of the rod guide 6. A suspension spring S is stacked on the upper side of the spring bearing 7. The suspension spring S is a coil spring, and the upper end of the suspension spring S is supported by the outer tube 1 via a cap 10. On the other hand, the lower end of the suspension spring S is supported by the inner tube 2 via the spring bearing 7 and the cylinder 3.

Thus, the suspension spring S is interposed between the outer tube 1 and the inner tube 2. Then, when the front fork F contracts and the inner tube 2 intrudes into the outer tube 1, the suspension spring S is compressed and elastically deformed, and an elastic force corresponding to the amount of deformation is exerted to extend the front fork F in the extending direction Encourage. In the front fork F, the suspension spring S elastically supports the vehicle body.

Further, the spring bearing 7 is annular and is in contact with the upper end of the cylinder 3 and a seat portion 7a which abuts on the inner periphery of the inner tube 2, and an outer fitting portion which protrudes downward from the seat portion 7a and fits on the outer periphery of the cylinder 3. And 7b. As described above, since the seat portion 7a supported by the cylinder 3 abuts on the inner tube 2, the suspension spring S is seated at a position shifted to the outer peripheral side from the contact position between the cylinder 3 and the seat portion 7a. However, it is possible to prevent the outer peripheral side of the spring bearing 7 from being inclined so as to be lower than the inner peripheral side.

Furthermore, a notch 7 c is formed in the spring bearing 7 so that the liquid storage chamber R is not divided by the spring bearing 7. Therefore, when the liquid moves in and out of the cylinder 3 when the front fork F is expanded and contracted, the liquid flows between the upper side of the spring receiver 7 and the outer peripheral side of the cylinder 3 through the notch 7c.

In addition, the structure of the spring bearing 7 can be changed suitably. For example, the spring bearing 7 may be a washer and be stacked on the cylinder 3. In addition, the configuration and arrangement of the suspension spring S can be changed as appropriate. For example, the suspension spring S may be a spring other than a coil spring such as an air spring. As described above, when the suspension spring S is an air spring, the gas is compressed and sealed above the liquid surface of the liquid storage chamber R, and the air chamber in which the gas is sealed is used for the air spring. The receiver 7 may be eliminated. The suspension spring S may be accommodated in the cylinder 3 and compressed by the rod 5.

Subsequently, an extension cutting spring 8 is provided on the outer periphery of the rod 5 inserted into the cylinder 3 and between the rod guide 6 and the piston 4. Then, when the front fork F approaches the maximum extension state, the upper end of the extension cutting spring 8 abuts on the rod guide 6, and the extension cutting spring 8 is compressed and elastically deformed.

When compressed, the extension spring 8 exerts an elastic force commensurate with the amount of deformation thereof, and biases the front fork F in the contracting direction, that is, in the direction that hinders the extension of the front fork F. For this reason, the extension speed of the front fork F in the vicinity of the maximum extension can be reduced by the extension cut spring 8, and the impact at the maximum extension of the front fork F can be alleviated.

Thus, the extension cutting spring 8 and the piston 4 are accommodated below the rod guide 6 in the cylinder 3, and the portion is the cylinder body 3b. On the other hand, the upper side of the rod guide 6 in the cylinder 3 is a lock case 3c.

The liquid surface of the liquid storage chamber R is at a position higher than the upper end of the lock case 3c, and the lock case 3c is provided in a state of being immersed in the liquid. Further, an annular lock piece 9 is provided on the outer periphery of the rod 5 projecting upward of the rod guide 6. The lock piece 9 can slide on the inner periphery of the lock case 3c, and when the front fork F approaches the fully contracted state, the lock piece 9 intrudes into the lock case 3c and locks the lock chamber 30 in the lock case 3c. Form

At this time, the lock chamber 30 is partitioned by the liquid storage chamber R outside the lock case 3 c and the lock piece 9, and is partitioned by the liquid chamber inside the cylinder 3 and the rod guide 6. Then, when the lock piece 9 moves in the lock case 3c to the back side (rod guide 6 side) with the contraction of the front fork F and the lock chamber 30 is contracted, the liquid in the lock chamber 30 is the lock piece 9 and the lock case 3c. Flow out into the liquid storage chamber R through the sliding gap between them.

The sliding gap is a narrow gap and a resistance is applied when the liquid flows in the sliding gap, so when the lock piece 9 moves to the back side in the lock case 3c, the pressure of the lock chamber 30 rises and the front A position dependent secondary damping force that prevents the contraction of the fork F is generated and is added to the main compression side damping force by the damper D. For this reason, the compression side damping force near the full contraction of the front fork F is increased, and the contraction speed of the front fork F can be reduced by the large compression side damping force, and the impact of the front fork F at the full contraction can be alleviated.

Further, an orifice 3d which penetrates the thickness of the lock case 3c is formed in the upper portion of the lock case 3c. Therefore, when the lock piece 9 moves to the back side in the lock case 3 c and the lower end of the lock piece 9 is at a position higher than the orifice 3 d, the liquid in the lock chamber 30 is on the outer periphery of the lock piece 9. In addition to the sliding gap, it can flow out of the lock case 3c through the orifice 3d.

On the other hand, when the lock piece 9 deeply penetrates the lock case 3 c and the upper end of the lock piece 9 moves to a position lower than the orifice 3 d, the lock chamber 30 and the orifice 3 d are separated by the lock piece 9. For this reason, when the lock piece 9 advances further in the lock case 3c in such a state, the liquid in the lock chamber 30 moves out of the lock case 3c only through the sliding gap on the outer periphery of the lock piece 9 You will come to

Therefore, when the lock piece 9 is at a position higher than the orifice 3 d, the flow of the flow path connecting the lock chamber 30 and the liquid storage chamber R as compared with the case where the lock piece 9 is at a position lower than the orifice 3 d. As the road area increases, the secondary damping force generated at this time decreases.

In other words, since the secondary damping force that occurs when the lock piece 9 is in the shallow position in the lock case 3c can be reduced, the intrusion of the lock piece 9 into the lock case 3c when the front fork F contracts is bounded. Sudden changes in damping force can be suppressed, and sudden changes in ride feeling can be suppressed. Furthermore, since the secondary damping force generated when the lock piece 9 moves to a deep position in the lock case 3c can be increased, the impact at the time of the last contraction of the front fork F can be reliably alleviated.

In addition, the characteristics of the secondary damping force generated when the liquid flows through the orifice 3d changes according to the position, the number, the size, the shape, and the like of the orifice 3d, and the riding feeling changes. Therefore, it goes without saying that the position, number, size, shape, etc. of the orifices 3d can be changed so as to obtain a riding feeling that suits the occupant's preference. Furthermore, the upper end portion of the lock case 3c may be expanded, or a groove may be formed on the inner periphery of the lock case 3c to have the same function as the orifice 3d.

Hereinafter, the operation and effect of the front fork F according to the present embodiment will be described.

In the present embodiment, the front fork F is attached to the cylinder 3, the rod 5 movably inserted into the cylinder 3, and the rod guide attached to the inner periphery of the cylinder 3 and slidably supporting the rod 5. And 6. And in this embodiment, the tip part of cylinder 3 projected from the rod guide 6 serves as lock case 3c.

The tip portion of the cylinder 3 is a portion including one end of the cylinder 3 in the axial direction. The lock case 3 c is a kind of cushion case used to reduce the impact of the front fork F when it is fully contracted. And in this embodiment, while utilizing a part of one cylinder 3 as lock case (cushion case) 3c, the rod guide 6 separately formed with the said lock case 3c is attached to the inner periphery of the cylinder 3 ing. Therefore, according to the above configuration, since the lock case (cushion case) 3c and the rod guide 6 can be formed separately, these shapes can be simplified and the parts cost can be reduced.

Furthermore, in the present embodiment, a part of the cylinder 3 is used as the lock case (cushion case) 3c. Therefore, as described above, the number of parts does not increase even if the lock case 3c and the rod guide 6 are separately formed. And in this embodiment, although the process of attaching the rod guide 6 to the cylinder 3 is required, the process of attaching the lock case 3c to the cylinder 3 is unnecessary. Therefore, in the present embodiment, the number of assembling steps does not increase as compared with the case where the cylinder head including the rod guide and the cushion case is attached to the cylinder as in the prior art. For this reason, according to the above configuration, the cost of the front fork F can be reduced without reducing the effect of reducing the cost of parts.

Further, in the present embodiment, the caulking portion 3 a formed in the cylinder 3 is fitted to the rod guide 6, whereby the rod guide 6 is attached to the inner periphery of the cylinder 3.

The caulking portion 3a is a portion plastically deformed by caulking. According to the above configuration, the rod guide 6 can be attached to the inner periphery of the cylinder 3 by caulking. That is, according to the above configuration, since screw fastening is not used for attachment of the rod guide 6 to the cylinder 3, screw processing and screwing work at the time of manufacturing the front fork F can be reduced to further reduce cost.

The method of attaching the rod guide 6 to the inner periphery of the cylinder 3 is not limited to the above, and can be changed as appropriate. For example, as shown in FIG. 2, the rod guide 6 may be sandwiched and fixed by a pair of snap rings 61 and 62 mounted on the inner periphery of the cylinder 3. Although not shown, a step may be formed on the inner periphery of the cylinder 3 and the rod guide 6 may be sandwiched and fixed between the step and one snap ring.

Further, in the present embodiment, an annular lock piece 9 forming the lock chamber 30 in the lock case (cushion case) 3 c is provided on the outer periphery of the rod 5. Furthermore, the lock chamber 30 is separated from the liquid chamber (anti-lock chamber side) in the cylinder 3 by the rod guide 6. Then, when the lock piece 9 moves to the back side in the lock case 3 c, resistance is given to the flow of the liquid from the lock chamber 30 to the outside of the lock case 3 c through the space between the lock case 3 c and the lock piece 9.

According to the above configuration, when the lock piece 9 moves to the back side in the lock case 3c, the liquid flows from the inside to the outside of the lock chamber 30, resistance is applied to the flow, and a position-dependent damping force is generated. Then, the contraction speed of the front fork F can be reduced by the damping force, and the impact at the time of the last contraction can be alleviated. As described above, according to the above configuration, the hydraulic lock member can reduce the impact of the front fork F when it is fully contracted, and the cushion case functions as the lock case 3c of the hydraulic lock member.

Furthermore, in the present embodiment, the lock case 3c constituting the fluid pressure lock member is formed with an orifice 3d that resists the flow of the liquid from the lock chamber 30 to the outside of the lock case 3c. For this reason, the characteristics of the damping force by the hydraulic pressure lock member can be set by the position, number, size, shape, etc. of the orifice 3d.

For example, if the orifice 3d is enlarged, the damping force by the fluid pressure lock member when the liquid flows through the orifice can be reduced. In addition, if the position of the orifice 3d is lowered, the timing to increase the damping force by the hydraulic pressure lock member can be delayed (close to the time of contraction of the front fork F). Furthermore, if a plurality of orifices are provided offset in the axial direction of the lock case 3c, the damping force by the fluid pressure lock member can be gradually increased as the front fork F approaches its full contraction state.

And according to the above configuration, there is no need to expand the inner diameter of the lock case 3c for the purpose of setting the characteristics of the damping force by such a hydraulic pressure lock member, and the lock case 3c and the cylinder main body 3b Since the inner diameter can be made the same, the cylinder 3 can be easily formed.

Specifically, in order to form the cylinder 3 having the same inner diameter of the lock case 3c and the cylinder body 3b, the rod guide 6 may be attached to the inner periphery of one tube having a constant inner diameter by caulking or the like. Further, since the orifice 3d can be easily formed by drilling or the like, it is extremely easy to form the cylinder 3 having the same inner diameter of the lock case 3c and the cylinder body 3b, including the lock case 3c in which the orifice 3d is formed. .

For this reason, in the front fork F of the present embodiment, the inner diameters of the lock case 3c and the cylinder body 3b are equal. However, a part of the tube which is a base material of the cylinder 3 may be expanded or squeezed to form an enlarged diameter portion or a reduced diameter portion in a part of the lock case 3c or the cylinder main body 3b.

In addition, the configuration of the lock piece 9 of the hydraulic pressure lock member can be appropriately changed. For example, although not shown, an annular lock piece through which the rod 5 is movably inserted in the axial direction is slidably accommodated in the lock case 3c, and mounted on the outer periphery of the rod 5 near the full contraction of the front fork. The lock piece may be pushed into the lock case 3c by the stopper.

Further, as shown in FIG. 3, instead of the hydraulic lock member, the cushion rubber 90 made of rubber is used to relieve the shock at the time of the maximum contraction, and the lock case (cushion case) 3c in the diameter expanding direction of the cushion rubber 90. You may utilize as a rubber case 3e which limits a deformation | transformation. In order to do this, the cushion rubber 90 may be elastically deformed when the front fork is fully contracted so that the outer periphery thereof is in contact with the inner periphery of the rubber case 3e.

According to the above configuration, when the front fork approaches the fully contracted state, the cushion rubber 90 is inserted into the rubber case 3 e and collides with the rod guide 6 to be elastically deformed. Then, the cushion rubber 90 exerts an elastic force commensurate with the amount of deformation, and biases the front fork in the extension direction, that is, in the direction that prevents the contraction of the front fork. From such a state, when the front fork is further contracted and the outer periphery of the cushion rubber 90 abuts on the rubber case 3e, further deformation in the radial direction of the cushion rubber 90 is prevented to resist contraction. The power is even greater.

For this reason, according to the above configuration, it is possible to suppress a sudden change in the riding feeling bordering on the elastic deformation of the cushion rubber 90, and to reliably relieve the impact at the time of the last contraction of the front fork F.

In addition, the structure of the cushion rubber 90 can also be changed suitably. For example, although not shown, a cylindrical cushion rubber through which the rod 5 is movably inserted in the axial direction is accommodated in the rubber case 3e, and a stopper attached to the outer periphery of the rod 5 near the full contraction of the front fork The cushion rubber may be compressed. Furthermore, the shape of the cushion rubber is not limited to the tubular shape.

Further, as described above, when the cushion case is the rubber case 3e, the inner side of the rubber case 3e and the inner side of the cylinder main body 3b may not necessarily be partitioned by the rod guide 6. Specifically, the piston passage, the bottom passage, and the damping element are eliminated, and the suspension spring accommodated in the cylinder 3 is compressed by the rod 5, and the cylinder 3, the rod 5, the rod guide 6, and the suspension spring The case where an apparatus is configured corresponds to that.

Also, the cushion rubber and the oil lock piece may be used in combination, and the change of the configuration of the impact relaxation mechanism at the time of the last contraction of the front fork as described above is possible without being limited to the fixing method of the rod guide 6.

Further, in the present embodiment, a notch 7c is formed in the annular spring receiver 7 interposed between the lock case 3c and the suspension spring S, and the liquid in the liquid reservoir R passes through the notch 7c. Thus, it is possible to move between the upper side of the spring receiver 7 and the outer peripheral side of the cylinder 3. For this reason, even when the liquid corresponding to the rod volume moves into and out of the cylinder 3 during expansion and contraction of the front fork F as in the present embodiment, the liquid is insufficient on the outer peripheral side of the cylinder 3 You can prevent it.

However, instead of the notch 7c of the spring bearing 7, a through hole or a notch may be formed in the lock case 3c. Further, the upper end portion of the cylinder 3 may be bent outward to form a bent portion, and the bent portion may be used instead of the spring receiver 7. And these changes are possible irrespective of the fixing method of rod guide 6, and, of course, it is possible also when using lock case 3c as rubber case 3e.

Further, in the present embodiment, the inner tube 2 separate from the cylinder 3 is provided on the outer periphery of the cylinder 3. However, the cylinder 3 is eliminated and the inner tube 2 is provided with a function as a cylinder, and while the rod guide 6 is fixed to the inner periphery of the inner tube 2, the upper side of the inner tube 2 beyond the rod guide 6 is used as the lock case 3 c. Good. Such a change is possible regardless of the fixing method of the rod guide 6 and the configuration of the spring bearing 7 and, of course, also when the lock case 3c is used as the rubber case 3e.

While the preferred embodiments of the present invention have been described above in detail, modifications, variations and changes are possible without departing from the scope of the claims.

The present application claims priority based on Japanese Patent Application No. 2017-208150 filed on Oct. 27, 2017, to the Japanese Patent Office, and the entire contents of this application are incorporated herein by reference.

Claims (5)

Front fork,
With the cylinder,
A rod movably inserted into the cylinder;
And a rod guide attached to the inner periphery of the cylinder and slidably supporting the rod.
A front fork in which a tip portion of the cylinder protruding from the rod guide is a cushion case. A front fork according to claim 1, wherein
A front fork in which a caulking portion formed on the cylinder is fitted to the rod guide. A front fork according to claim 1, wherein
An annular lock piece is provided on the outer periphery of the rod to form a lock chamber in the cushion case,
The lock chamber is separated from the non-lock chamber side in the cylinder by the rod guide,
A front fork that resists the flow of liquid from the lock chamber to the outside of the cushion case as it passes between the cushion case and the lock piece as the lock piece travels backward in the cushion case. A front fork according to claim 3, wherein
A front fork having an orifice for resisting the flow of liquid from the lock chamber to the outside of the cushion case. A front fork according to claim 1, wherein
A cushion rubber is provided on the outer periphery of the rod,
At the time of the last contraction, the cushion rubber is compressed and elastically deformed, and the outer periphery of the cushion rubber abuts on the inner periphery of the cushion case.

Images