JP6144499B2 - A front fork of a motorcycle and an outer cylinder attached to an outer peripheral surface of a cylinder of an outer tube constituting the front fork - Google Patents

Description

  The present invention relates to a front fork or the like of a motorcycle configured to be able to change the rigidity of an outer tube while being attached to a vehicle body.

Conventionally, an outer tube and an inner tube formed by a cylinder are provided, and the inner tube is inserted into the inner tube from one end opening side through the one end opening of the outer tube, and the inner tube and the outer tube are respectively cylinders. In the front fork of a motorcycle that functions as a shock absorber configured to be movable in the direction along the central axis of the outer tube, the rigidity of the outer tube is varied at the circumferential position of the outer tube or the longitudinal position of the outer tube. A front fork provided with an outer tube having a structure is known (see Patent Documents 1 to 3, etc.).
In the outer tube of Patent Document 1, the outer tube of Patent Document 2 is bonded to the outer peripheral surface of the outer tube separately from the outer tube by changing the assembly angle of the yarn forming the outer tube. Thus, in the outer tube of Patent Document 3, the rigidity of the outer tube is varied at the position in the circumferential direction of the outer tube or the position in the longitudinal direction of the outer tube by cutting a part of the outer peripheral surface of the outer tube. It is a configuration.

Japanese Patent No. 4886710 Japanese Patent No. 4648769 JP 2000-18303 A

However, with the above-described conventional front fork, the rigidity of the outer tube cannot be changed while being attached to the vehicle body.
The present invention provides a front fork or the like of a motorcycle that can change the rigidity of an outer tube while being attached to a vehicle body.

A front fork of a motorcycle according to the present invention includes an outer tube formed of a cylinder and an outer cylindrical body attached to an outer peripheral surface of the cylinder of the outer tube, and an inner formed of a cylinder. A tube, and the inner tube is inserted into the outer tube from the one end opening side through the one end opening of the outer tube, and the inner tube and the outer tube are each along the center axis of the cylinder. A motorcycle front fork configured to be movable in a direction, wherein the variable stiffness outer tube is connected to a vehicle body so that the outer cylinder is in close contact with an outer peripheral surface of a cylinder of the outer tube. The rigidity of the outer tube is increased by being fixed to the bracket fixing portion. Configured urchin, and when a state where the outer cylinder to a fixed portion of the bracket is fixed is released, is configured to be movable in a direction in which the outer cylinder is along the central axis of the outer tube And the exterior cylinder has a notch portion that is open at one end of the cylinder, extends from one end of the cylinder toward the other end of the cylinder, and does not open at the other end of the cylinder . In addition to providing a front fork that can change the longitudinal rigidity of the outer tube while attached to the vehicle body, and when the exterior cylinder is fixed to the fixed part of the bracket, Since the inner peripheral surface of the cylinder can be easily adhered to the outer peripheral surface of the outer tube, and the fastening rigidity between the outer cylinder and the outer tube can be easily obtained, the rigidity of the outer tube can be increased. Rutotomoni, when the outer cylinder and the outer tube has cleared state of being fixed to the bracket, when moving the outer Sotsutsutai in a direction along the central axis of the outer tube, the cylinder of the outer cylinder Since the frictional resistance with the outer peripheral surface of the outer tube on one end side can be reduced, a front fork that can easily change the rigidity of the outer tube with the exterior cylinder attached to the outer peripheral surface of the outer tube is provided it can.
The front Symbol rigidity changing the outer tube before when the the fixing portion of the Kivu racket state outer cylinder is fixed is released, in a direction in which the outer cylinder is along the central axis of the outer tube Since it is configured to be movable and to be able to rotate around the outer peripheral surface of the outer tube with the central axis as the center of rotation, it is possible to change the circumferential rigidity of the outer tube while attached to the vehicle body. Can provide forks.
An exterior cylinder attached to an outer peripheral surface of a cylinder of an outer tube in a front fork of the motorcycle, which opens to one end of the cylinder and extends from one end of the cylinder to the other end of the cylinder and opens to the other end of the cylinder Since the notched portion of the other end opening is closed, when the exterior cylinder is fixed to the fixing portion of the bracket, the inner peripheral surface of the outer cylinder is brought to the outer peripheral surface of the outer tube by the fastening force of the fixing portion. Since it becomes easy to adhere and it is easy to obtain the fastening rigidity between the outer cylinder and the outer tube, the rigidity of the outer tube can be increased and the state where the outer cylinder and the outer tube are fixed to the bracket is released. The outer cylinder is rotated about the center axis of the outer tube, or the outer cylinder is moved in a direction along the center axis of the outer tube. In this case, since the frictional resistance with the outer peripheral surface of the outer tube on one end side of the cylinder of the outer cylinder can be reduced, the rigidity of the outer tube can be easily increased with the outer cylinder attached to the outer peripheral surface of the outer tube. Can be changed.
Further, the cutout portion of the outer cylindrical body includes a linear slit portion extending linearly from one end of the tube toward the other end side of the tube, and from the end of the linear slit portion toward the other end side of the tube. And an enlarged slit portion provided so as to extend, so that when the exterior cylinder is fixed to the fixing portion of the bracket, the inner peripheral surface of the exterior cylinder is the outer tube cylinder by the fastening force of the fixing portion. The outer tube can be easily adhered to the outer peripheral surface, and the outer tube and the outer tube can be easily tightened. Therefore, the outer tube can be increased in rigidity, and the outer tube and the outer tube fixed to the fixing portion of the bracket can be increased. When the outer cylinder is rotated around the central axis of the outer tube when the fixed state with the tube is released, the outer cylinder is moved in the direction along the central axis of the outer tube. Since the friction resistance with the outer peripheral surface of the outer tube on one end side of the cylinder of the outer cylinder can be reduced, the rigidity of the outer tube can be easily maintained with the outer cylinder attached to the outer peripheral surface of the outer tube. Can be changed.

The side view which shows the front-wheel side of a motorcycle. The front view which looked at the front fork from the front side of the motorcycle. The figure which shows the rigidity variable outer tube connected with the fixing | fixed part of the bracket. The perspective view which showed the outer tube and the exterior cylinder separately. The perspective view which shows the state by which the exterior cylinder was attached to the outer peripheral surface of an outer tube. The figure which shows an exterior cylinder.

  Hereinafter, the present invention will be described in detail through embodiments of the invention. However, the following embodiments do not limit the invention according to the claims, and all combinations of features described in the embodiments are included in the invention. It is not necessarily essential to the solution, but includes a configuration that is selectively adopted.

A front fork 1 of a motorcycle according to an embodiment will be described with reference to FIGS. 1 to 6.
As shown in FIG. 1, a front fork 1 is detachably attached to an outer tube 2 formed of a cylinder and an outer peripheral surface of the cylinder of the outer tube 2 from the upper end (other end) side of the cylinder of the outer tube 2. The outer tube 4 is provided with an outer tube 4 having a variable rigidity and an inner tube 5. The inner tube 5 is connected to the outer tube 2 through one end opening of the outer tube 2 from one end opening side of the tube. Inserted inside, the inner tube 5 and the outer tube 2 are each configured to be movable in a direction along the central axis of the cylinder. That is, the inner tube 5 and the outer tube 2 are arranged coaxially so that the central axes of the cylinders coincide with each other, and are configured to be movable in a direction along the central axis.
For example, the front fork 1 has a built-in damping mechanism and a spring reaction force using a hydraulic pressure that obtains a damping force when the inner tube 5 and the outer tube 2 move in the direction along the central axis of the cylinder. It is a configuration.
A seal case 20 that slidably supports the inner tube 5 via an oil seal (not shown) is provided at the lower end (one end opening side) of the outer tube 2. The outer diameter of the seal case 20 is larger than the outer diameter of the portion other than the seal case 20 in the outer tube 2 or the same diameter as the outer diameter of the portion other than the seal case 20. Fork oil is sealed inside the outer tube 2 via the upper end opening (the other end opening) of the outer tube 2, and the upper end opening of the outer tube 2 is sealed with a lid material (not shown).
The outer tube 2 and the inner tube 5 are made of a metal such as aluminum or iron, for example.

  A front fork 1 is disposed on the left and right sides of the front wheel 6 of the motorcycle, and the lower end side (the other end side) of the inner tube 5; 5 of each front fork 1: 1 is connected to the axle 7 of the front wheel 6 to The front suspension of the motorcycle that reduces the impact received by the front wheels 6 from the ground by connecting each of the variable stiffness outer tubes 4; 4 in the fork 1: 1 to the vehicle body 8 via the upper bracket 10 and the under bracket 12. Composed.

As shown in FIG. 2, the upper end side (the other end side) of the outer tube 2 in the left stiffness variable outer tube 4 is connected and fixed to the left fixing portion 11 of the upper bracket 10, and the outer stiffness in the right stiffness variable outer tube 4. The upper end side (the other end side) of the tube 2 is connected and fixed to the right fixing portion 11 of the upper bracket 10.
The central portion of the left variable stiffness outer tube 4 is connected and fixed to the left fixed portion 13 of the under bracket 12, and the central portion of the right variable stiffness outer tube 4 is connected and fixed to the right fixed portion 13 of the under bracket 12. .

  A handle rotation shaft 14 provided so as to connect the upper bracket 10 and the under bracket 12 is pivotally supported by a head pipe 15 provided at a front end portion of the vehicle body 8. That is, the handle rotating shaft 14 is supported by the head pipe 15 so as to be rotatable about the central axis 14A. Therefore, for example, by steering a handle (not shown) attached to the upper bracket 10, the handle rotation shaft 14 rotates about the central axis 14 </ b> A as a rotation center, and the upper bracket 10 and the under bracket 12 connected to the handle rotation shaft 14. Sway left and right, and the direction of the front wheel 6 can be changed, so that the traveling direction of the motorcycle can be changed.

The exterior cylinder 3 is made of, for example, carbon fiber reinforced plastic (CFRP), metal, or the like. The outer cylinder 3 is attached to the outer peripheral surface of the outer tube 2 through the upper end (the other end) of the outer tube 2 from one end of the tube.
The outer cylinder 3 is fixed to the fixing portion 13 of the under bracket 12 so as to be pressed against the outer peripheral surface of the outer tube 2 and in close contact with the outer peripheral surface of the outer tube 2. When the state fixed to the portion 13 is released, the outer tube 2 can move in the direction along the central axis 2A of the outer tube 2, and around the outer peripheral surface of the outer tube 2 with the central axis 2A of the outer tube 2 as the rotation center. Configured to be rotatable.

The outer cylinder 3 is formed to have a diameter larger than the outer diameter of a portion other than the seal case 20 in the outer tube 2 and smaller than the outer diameter of the seal case 20 in the outer tube 2. Two notches extending from one end of the cylinder of the circular cylinder toward the other end of the cylinder of the circular cylinder using a circular cylinder formed to have an inner diameter that fits to the outer peripheral surface of the cylinder It is the structure provided with the part (slit) 40; 40 (refer FIG. 4).
The start ends 41; 41 of the notches 40; 40 are provided at positions spaced from each other by 180 ° on the circumference of one end of the circular cylindrical body (see FIG. 6).
Each notch 40; 40 has an n-fold rotationally symmetric shape with the center axis of the cylindrical cylinder as the center of rotation, for example, as shown in FIG. 4, it has two-fold symmetry with the center axis of the cylindrical cylinder as the center of rotation. Are formed in a rotationally symmetric shape (180 ° rotationally symmetric shape).
As described above, if the exterior cylinder 3 having the notch portion 40 formed in a rotationally symmetric shape with n-fold symmetry about the central axis of the cylindrical cylinder is used, the right and left stiffness balance of the outer tube 2 is balanced. It becomes easy.

The notch 40 includes a linear slit 42 extending linearly from one end of the cylinder of the circular cylinder toward the other end of the cylinder of the circular cylinder, and a circular cylinder from the end of the linear slit 42. A diameter-enlarging slit portion 43 provided so as to extend toward the other end side of the cylinder.
For example, as shown in FIG. 6, the diameter-enlarging slit portion 43 is arranged in the circumferential direction of the cylinder from the end of each of the groove edges facing each other forming the linear slit portion 42 toward the other end side of the cylinder of the circular cylinder. After extending so as to be separated from each other, it is formed by an opening edge that forms a teardrop-shaped opening that is connected on the central axis 42 </ b> A of the groove of the linear slit portion 42.
That is, the notch 40 is formed by a notch that opens at one end of the cylinder of the outer cylinder 3 and extends from one end of the cylinder toward the other end of the cylinder and does not open at the other end of the cylinder. .
The linear slit portion 42 functions as a communication portion that communicates the enlarged-diameter slit portion 43 that forms a through hole that communicates with the inner peripheral surface and the outer peripheral surface of the circular cylindrical body and one end of the circular cylindrical body. To do.
One end portion 44 of the cylindrical tube with a slit forming the outer cylindrical body 3 approaches one end of the outer cylindrical body 3 from a boundary portion 45 between the one end portion 44 of the outer cylindrical body 3 and a portion other than the one end portion 44. Accordingly, it is formed to have a tapered cylindrical shape that gradually decreases in outer diameter. That is, the outer peripheral surface of the one end portion 44 is formed as an inclined surface that gradually approaches the central axis of the outer casing 3 from the boundary portion 45 toward one end of the outer casing 3. Since the one end portion 44 is formed in a tapered cylindrical shape, the exterior cylinder 3 can be easily inserted into the connection hole of the under bracket 12 from the lower side of the under bracket 12, and the exterior cylinder 3 is connected to the under bracket 12. It becomes easy to remove from the hole.

For example, as shown in FIG. 3, the fixing portion 11 of the upper bracket 10 and the fixing portion 13 of the under bracket 12 are partly cut off from a ring that forms a round hole. The ends 16; 16 are fastened to each other by bolts 17 and nuts 18 so that the outer cylindrical body 3 of the variable rigidity outer tube 4 is brought into close contact with the outer peripheral surface of the outer tube 2 so as to increase the rigidity of the outer tube 2. The connecting hole 19 for fixing the variable stiffness outer tube 4 is formed, or although not shown, the ring forming the round hole is divided into two, and the ends of the two divided arc bodies are bolts and By fastening with a nut, the outer cylinder 3 of the outer tube 2 with variable rigidity is brought into close contact with the outer peripheral surface of the outer tube 2 to increase the rigidity of the outer tube 2. A structure in which connecting holes for fixing the urchin variable stiffness outer tube 4 is formed.
The fixing portion 13 of the under bracket 12 is configured such that the outer cylindrical body 3 of the variable rigidity outer tube 4 is attached to the outer periphery of the outer tube 2 by fastening a bolt to a screw hole formed at the end of the under bracket 12. The structure which fixes the rigidity variable outer tube 4 to a connection hole so that it may contact | adhere to a surface and the rigidity of the outer tube 2 may be raised may be sufficient.

For example, after passing the outer tube 2 from the upper end side (the other end side) through the connection hole 19 in a state where the bolt 17 and the nut 18 are loosened, the other end side of the cylinder of the outer cylinder 3 is connected to the upper end side of the outer tube 2. The outer cylindrical body 3 is mounted on the outer peripheral surface of the outer tube 2 and is positioned inside the connecting hole 19 of the under bracket 12, or the outer cylindrical body 3 is mounted on the outer peripheral surface of the outer tube 2. The variable rigidity outer tube 4 is positioned inside the connection hole 19 of the under bracket 12.
Then, the bolt 17 and the nut 18 of the upper bracket 10 are fastened to connect and fix the upper end side (the other end side) of the outer tube 3 to the connection hole of the upper bracket 10. Further, the outer cylindrical body 3 and the outer tube are fastened so that the inner peripheral surface of the cylinder of the outer cylindrical body 3 and the outer peripheral surface of the outer tube 2 are in close contact with each other by fastening the bolt 17 and the nut 18 of the under bracket 12. 2 is connected and fixed to the connecting hole 19 of the under bracket 12.
Thus, since the variable rigidity outer tube 4 connected and fixed to the connection hole 19 of the upper bracket 10 and the connection hole 19 of the under bracket 12 has the outer cylindrical body 3, it is more rigid than the case of only the outer tube 2. Is up.

Further, the bolt 17 and the nut 18 that connect and fix the outer cylinder 3 and the outer tube 2 to the connection hole 19 of the under bracket 12 are loosened, and the outer cylinder 3 and the outer tube 2 are connected to the connection hole 19. When the connected and fixed state is released, the outer cylinder 3 can move in the direction X around the outer periphery of the outer tube 3 and in the direction Y along the central axis 2A of the outer tube 2 (FIG. 1; FIG. 5).
In other words, by rotating the outer cylinder 3 around the center axis 2A of the outer tube 2 as the rotation center, the front fork 1 can change the circumferential rigidity of the outer tube 2 while being attached to the vehicle body 8. The front and rear of the front fork 1; the left and right stiffness balance can be changed.
Further, the front fork 1 capable of changing the longitudinal rigidity of the outer tube 2 while being attached to the vehicle body 8 by moving the outer cylinder 3 in the direction along the central axis 2 </ b> A of the outer tube 2. It becomes. That is, the rigidity of the front fork 1 can be increased by moving the outer cylinder 3 to the lower end side (one end side) of the outer tube 2, and the outer cylinder 3 is moved to the upper end side (the other end side) of the outer tube 2. The rigidity of the front fork 1 can be lowered by moving it.

  The outer cylinder 3 includes a notch 40 that opens at one end of the cylinder, that is, a diameter-enlarged slit 43 that functions as a through-hole that communicates with the inner peripheral surface and the outer peripheral surface of the circular cylindrical cylinder, and the circular cylindrical cylinder. Since the linear slit portion 42 that functions as a communication portion that communicates with one end of the outer cylinder 3 is provided, when the outer cylinder 3 is connected and fixed to the connecting hole of the under bracket 12, the outer cylinder is driven by the fastening force of the fixing portion 13. Since the inner peripheral surface of the body 3 is easily brought into close contact with the outer peripheral surface of the cylinder of the outer tube 2 and the fastening rigidity between the outer cylinder 3 and the outer tube 2 is easily obtained, the rigidity of the outer tube 2 can be increased. At the same time, when the outer tube 2 connected and fixed to the connecting hole 19 is released, the outer tube 3 is rotated about the central axis 2A of the outer tube 2 as the center of rotation. When the outer cylinder 3 is moved in the direction along the central axis 2A of the outer tube 2, the frictional resistance with the outer peripheral surface of the outer tube 2 on one end side of the cylinder of the outer cylinder 3 can be reduced. Therefore, the rigidity of the outer tube 2 can be easily changed in a state where the outer cylinder 3 is attached to the outer peripheral surface of the outer tube 2.

In addition, although the example using the exterior cylinder body 3 provided with the notch part 40 opened to the end of a cylinder was shown above, the exterior cylinder body 3 is a through-hole connected to the inner peripheral surface and outer peripheral surface of a cylinder. What is necessary is just the structure which has the notch part formed by. Even with such an outer cylinder 3, the rigidity balance between the front and rear of the front fork 1 and the right and left can be changed by rotating the outer cylinder 3 around the central axis 2A of the outer tube 2 as a rotation center. A front fork capable of changing the rigidity of the outer tube 2 by moving the outer cylinder 3 in the direction along the central axis 2A of the outer tube 2 can be configured.
As described above, the outer cylindrical body 3 having the notch formed by the through hole communicating with the inner peripheral surface and the outer peripheral surface of the cylinder cannot be moved in the direction along the central axis 2A of the outer tube 2. The front fork configured to change the rigidity balance between the front and rear of the front fork 1 and the left and right by rotating the outer cylinder 3 about the center axis 2A of the outer tube 2 as a rotation center. It is good.

  The outer cylinder 3 may be configured to be fitted into the outer peripheral surface of the outer tube 2 from the side of the outer tube 2.

  The exterior cylinder 3 is configured by using an exterior cylinder 3 that is configured by a cylindrical cylinder having a configuration not provided with a notch and is attached to the outer peripheral surface of the cylinder of the outer tube 2 so as to increase the rigidity of the outer tube 2. It is good also as a front fork comprised so that the rigidity of outer tube 2 can be changed by moving in the direction along central axis 2A of outer tube 2.

  Also, if the exterior cylinder 3 for different types of rigidity is prepared by using different materials and different shapes of the enlarged diameter slit portion 43, the exterior cylinder 3 can be mounted with the front fork 1 attached to the vehicle body 8. It can be easily replaced and the rigidity of the outer tube 2 can be easily changed.

  In the embodiment, the inverted front fork has been described as an example, but the present invention can also be applied to an upright front fork.

1 Front fork, 2 Outer tube, 2A Outer tube center axis, 3 Exterior cylinder, 4 Rigid variable outer tube, 5 Inner tube,
12 Under bracket (bracket), 40 Notch,
42 linear slit portion (communication portion), 43 enlarged diameter slit portion (through hole).

Claims (4)

A rigid variable outer tube having an outer tube formed of a cylinder and an outer cylinder attached to the outer peripheral surface of the cylinder of the outer tube, and an inner tube formed of a cylinder,
The inner tube is inserted from the one end opening side into the outer tube through the one end opening of the outer tube, and the inner tube and the outer tube can be moved in a direction along the central axis of the cylinder. A motorcycle front fork,
The rigidity variable outer tube is fixed to a fixing portion of a bracket for connection with a vehicle body so that the outer cylindrical body is in close contact with the outer peripheral surface of the outer tube cylinder. The outer cylinder is configured to be movable in a direction along the central axis of the outer tube when the state where the outer cylinder is fixed to the fixing portion of the bracket is released. Has been
The outer cylinder is configured to include a cutout portion that is open at one end of the cylinder, extends from one end of the cylinder toward the other end of the cylinder, and does not open at the other end of the cylinder. Motorcycle front fork. Prior Symbol variable stiffness outer tube, when a state where the outer cylinder to the fixing portion of the bracket is fixed is released, the outer cylinder is movable in the direction along the central axis of the outer tube, and 2. The front fork of a motorcycle according to claim 1, wherein the front fork of the motorcycle is configured to be rotatable around an outer peripheral surface of the outer tube with the central axis as a rotation center. An exterior cylinder that is attached to the outer peripheral surface of a cylinder of an outer tube in a front fork of a motorcycle according to claim 1 or claim 2,
An exterior cylinder having a notch portion that is open at one end of a cylinder, extends from one end of the cylinder toward the other end of the cylinder, and does not open at the other end of the cylinder. The notch is provided so as to extend linearly from one end of the cylinder toward the other end of the cylinder, and to extend from the end of the linear slit to the other end of the cylinder. The exterior cylinder according to claim 3 , further comprising an enlarged slit portion.

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