JP2011225198A - Front fork - Google Patents

Abstract

PROBLEM TO BE SOLVED: To downsize a spring leg in a front fork including a damper leg and the spring leg arranged in parallel to each other.SOLUTION: This front fork A includes the damper leg 10 and spring leg 110 which are arranged in parallel to each other. The spring leg 110 is so configured that a vehicle body tube 111 and an axle tube 112 are mutually inserted, a guide cylinder 121 is provided in the center of the inside of the vehicle tube 111, and the guide 123 of a guide rod 122 provided in the center of the inside of the axle tube 112 is inserted into the guide cylinder 121. A suspension spring 150 is interposed between the axle tube 112 and a spring receiver 148 provided inside of the vehicle body tube 111 and around the guide cylinder 121.

Description

  The present invention relates to a front fork suitable for use in a motorcycle or the like.

  2. Description of the Related Art Conventionally, as a front fork, as described in Patent Document 1, there is one in which a first damper leg incorporating a damper and a suspension spring and a second damper leg incorporating a damper and not incorporating a suspension spring are arranged in parallel. . That is, the cost of the second damper leg is reduced by omitting the suspension spring.

JP2008-265534

  The front fork described in Patent Document 1 has a heavy weight and a large number of parts built in both the first damper leg and the second damper leg even if the suspension spring is omitted from the second damper leg. And cost reduction cannot be realized.

  Therefore, in order to reduce the weight and reduce the cost of the front fork, the applicant of the present invention uses the second damper leg of the front fork described in Patent Document 1 as a suspension made of metal without a built-in damper as shown in FIG. We considered changing to a spring leg 1 with a built-in spring. In the front fork 1 shown in FIG. 10, the vehicle body side tube 2 and the axle side tube 3 are inserted into each other, the guide cylinder 4 is provided at the center inside the axle side tube 3, and is provided at the center inside the vehicle body side tube 2. The tip guide 6 of the guide rod 5 is inserted into the guide cylinder 4. A suspension spring 9 is interposed between the upper spring receiver 8 of the spring load adjusting device 7 provided around the guide rod 5 inside the vehicle body side tube 2 and the bottom portion of the axle side tube 3.

  However, in the front fork 1 shown in FIG. 10, the upper spring receiver 8 is provided on the vehicle body side tube 2 side, and the guide cylinder 4 is provided on the axle side tube 3 side. The receptacle 8 is opposed to the axial direction and moves relative to it. For this reason, it is necessary to secure a length exceeding the maximum value of the expansion / contraction stroke of the front fork 1 as the axial distance between the guide cylinder 4 and the upper spring receiver 8. The spring length of the spring 9 is longer than necessary. Since the spring length of the suspension spring 9 becomes longer than necessary, the upper end of the suspension spring 9 protrudes upward from the tip of the axle side tube 3 to bend and the tip of the axle side tube 3 is placed on the outer periphery of the suspension spring 9. There is an increased chance of interference, and there is a risk of friction, damage, generation of abrasion powder, and abnormal noise between the axle side tube 3 and the suspension spring 9.

  In addition, in the spring leg which comprises a front fork, in order to raise an air spring effect and to reduce the friction of the suspension spring consisting of a metal spring, it is necessary to load lubricating oil. Increasing the amount of oil has the disadvantage of increasing weight.

  In addition, it is desired that the damper leg and the spring leg constituting the front fork balance the rigidity of both the legs to suppress the swinging of the handle (yaw direction) during disturbance input.

  An object of the present invention is to make a spring leg compact in a front fork in which a damper leg and a spring leg are arranged in parallel.

  Another object of the present invention is to increase the air spring effect while reducing the amount of oil in the spring legs, and to reduce the friction of the suspension spring made of a metal spring.

  Another object of the present invention is to balance the rigidity of the damper leg and the spring leg.

  The invention according to claim 1 is a front fork in which a spring leg with a built-in suspension spring made of a metal spring and a damper leg with a built-in damper and no built-in suspension spring made of a metal spring are arranged in parallel. The spring leg inserts the vehicle body side tube and the axle side tube into each other, the guide cylinder is provided at the center inside the vehicle body side tube, and the guide rod guide provided at the center inside the axle side tube is the guide cylinder. The suspension spring is interposed between the spring receiver provided around the guide cylinder inside the vehicle body side tube and the axle side tube.

  The invention according to claim 2 is the spring load according to the invention according to claim 1, wherein the spring receiver can be displaced along the axial direction of the vehicle body side tube by an operation portion provided outside the vehicle body side tube in the spring leg. An adjusting device is provided around the guide cylinder.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, an oil chamber is provided in a lower portion of an internal space surrounded by the vehicle body side tube and the axle side tube in the spring leg, and an air chamber is provided in the upper portion. Thus, an air-filled case is provided around the guide rod below the oil level of the oil chamber.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the damper leg further inserts the vehicle body side tube and the axle side tube, and the damper cylinder is located in the center of the vehicle body side tube. A rod guide that is provided in the guide cylinder of the spring leg and is inserted into and supported by the guide cylinder of the spring leg in a front view of the front fork. The bush of the rod guide and the bush of the rod guide provided in the damper cylinder of the damper leg for inserting and supporting the piston rod are positioned at the same height position.

  The invention according to claim 5 is the invention according to claim 4, and further, the vehicle body side tube of the spring leg and the vehicle body side tube of the damper leg have the same diameter, and the axle side tube of the spring leg and the axle side of the damper leg. The tube has the same diameter, the spring leg guide cylinder and the damper leg damper cylinder have the same diameter, and the spring leg guide rod and damper leg piston rod have the same diameter.

  The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the spring leg further includes an inner air spring chamber in which a guide of a guide rod is defined in a guide cylinder, a vehicle body side tube, and an axle. The side tube has at least an outer air spring chamber defined outside the inner air spring chamber in the guide cylinder.

  The invention according to claim 7 is the invention according to claim 6, wherein the spring leg further adjusts the air pressure of the inner air spring chamber and the air pressure of the outer air spring chamber. And an outside air pressure adjusting unit.

(Claim 1)
(a) The spring leg inserts the vehicle body side tube and the axle side tube into each other, the guide cylinder is provided at the center inside the vehicle body side tube, and the guide rod guide provided at the center inside the axle side tube is used as the guide cylinder. A suspension spring is interposed between a spring holder provided around the guide cylinder inside the vehicle body side tube and the axle side tube. Therefore, the guide cylinder and the spring support are not arranged to face each other and move relative to each other, and a length exceeding the maximum value of the extension stroke of the spring leg is ensured in the axial facing distance between the guide cylinder and the spring support. This eliminates the need and improves the degree of freedom of design. In particular, the overall length of the spring leg is reduced, and the length of the suspension spring need not be longer than necessary.

  Further, the upper end of the suspension spring is guided by the outer periphery of the guide cylinder, and the torsion is suppressed. Even if the upper end of the suspension spring protrudes upward from the tip of the axle side tube, there is little chance that the outer periphery of the suspension spring whose curving is suppressed interferes with the tip of the axle side tube. Friction, damage, generation of wear powder and abnormal noise between the axle tube and suspension spring can be prevented.

(Claim 2)
(b) In the spring leg, the guide cylinder provided at the center inside the vehicle body side tube does not contain a damping force generator or the like. Therefore, a spring load adjusting device can be provided around the guide cylinder, and the operating portion of this spring load adjusting device can be provided outside the vehicle body side tube. The spring leg can be equipped with a spring load adjustment device.

(Claim 3)
(c) An oil chamber is provided in the lower part of the internal space surrounded by the vehicle body side tube and the axle side tube in the spring leg, and an air chamber is provided in the upper part, and air flows around the guide rod below the oil level in the oil chamber. An enclosing case is provided. The oil level can be raised by the volume of the air-filled case while reducing the amount of lubricating oil loaded in the oil chamber of the spring leg. Thereby, the compression ratio of an air chamber can be made high and an air spring effect can be raised. In addition, the oil scattering height range of the oil chamber is increased, and the friction reduction effect of the suspension spring made of a metal spring can be increased.

(Claim 4)
(d) In front view of the front fork, the bush of the rod guide provided in the guide cylinder of the spring leg for inserting and supporting the guide rod, and the rod guide provided in the damper cylinder of the damper leg for inserting and supporting the piston rod Are located at the same height position. The balance between the rigidity of the damper leg and the spring leg can be balanced, and the swinging (yaw direction) of the handle during disturbance input can be suppressed.

(Claim 5)
(e) The spring leg body side tube and the damper leg body side tube have the same diameter, and the spring leg axle side tube and damper leg axle side tube have the same diameter, and the spring leg guide cylinder and damper leg The damper cylinder has the same diameter, and the spring leg guide rod and the damper leg piston rod have the same diameter. The balance between the rigidity of the damper leg and the spring leg can be balanced, and the swinging (yaw direction) of the handle during disturbance input can be suppressed.

(Claim 6)
(f) An inner air spring chamber in which the guide of the guide rod is defined inside the guide cylinder, and an outer air spring in which the vehicle body side tube and the axle side tube are partitioned at least outside the inner air spring chamber in the guide cylinder. And a chamber. The air chamber provided in the inner space surrounded by the vehicle body side tube and the axle side tube in the spring leg is divided into an inner air spring chamber and an outer air spring chamber inside and outside the guide cylinder. Each of the inner air spring chamber and the outer air spring chamber becomes a small space corresponding to the two-divided portion and has a high compression ratio. The spring force F1 of the air spring of the inner air spring chamber and the air spring of the outer air spring chamber The spring force F2 is increased, and the overall air spring force (F1 + F2) of the spring leg can be increased.

  The spring force of the suspension spring made of the metal spring of the spring leg can be reduced by the amount that can increase the overall air spring force of the spring leg. As a result, the wire diameter of the suspension spring can be reduced and the weight can be reduced.

  (g) The air pressure and the outer air spring chamber of the inner air spring chamber and the outer air spring chamber are equal to the amount of the spring force (F1 + F2) of the entire spring leg shared by the spring force F1 of the inner air spring chamber and the spring force F2 of the outer air spring chamber. The overall air spring force (F1 + F2) can be increased while reducing the air pressure. Thereby, a certain air spring force characteristic can be secured while reducing the seal load exerted on the seal member of the inner air spring chamber and the seal member of the outer air spring chamber.

  (h) The air springs of the inner air spring chamber and the outer air spring chamber are used in combination with a suspension spring having a spring leg made of a metal spring. Therefore, the spring force in the latter half of the expansion / contraction stroke can be increased by the rise of the spring force of the air springs in the inner air spring chamber and the outer air spring chamber, and a spring force characteristic with struts can be obtained. The spring force in the initial to intermediate range of the expansion / contraction stroke is ensured by the suspension spring, so that the spring force characteristic with good riding comfort can be obtained without being moderately increased.

  (i) The air springs of the inner air spring chamber and the outer air spring chamber are used in combination with a suspension spring having a spring leg made of a metal spring. Therefore, even if the air in the inner air spring chamber and the outer air spring chamber escapes, the load for about one passenger can be supported by the suspension spring and can continue running.

  (j) Since the spring leg does not incorporate a damper, the air in the inner air spring chamber and the outer air spring chamber does not rise due to the oil temperature of the damper, and the inner air spring chamber and the outer air spring The spring force characteristic of the air spring of the chamber is stabilized without changing greatly.

(Claim 7)
(k) The spring leg has an inner air pressure adjusting portion for adjusting the air pressure of the inner air spring chamber and an outer air pressure adjusting portion for adjusting the air pressure of the outer air spring chamber. By adjusting the air pressure of the inner air spring chamber and the air pressure of the outer air spring, the air spring force characteristics of the entire spring leg can be variously changed.

FIG. 1 is a sectional view showing a front fork. FIG. 2 is a cross-sectional view showing the damper leg. FIG. 3 is a lower cross-sectional view of FIG. 4 is a top sectional view of FIG. FIG. 5 is a sectional view showing the spring leg. 6 is a lower cross-sectional view of FIG. FIG. 7 is a top sectional view of FIG. FIG. 8 is a sectional view showing a modification of the spring leg. FIG. 9 is a cross-sectional view of the main part of FIG. FIG. 10 is a schematic diagram showing a comparative example of spring legs. FIG. 11 is a sectional view showing the front fork. FIG. 12 is a sectional view showing a spring leg. 13 is a lower cross-sectional view of FIG. FIG. 14 is a top sectional view of FIG. FIG. 15 is a sectional view showing a modification of the spring leg. 16 is a cross-sectional view of the main part of FIG.

Example 1 (FIGS. 1 to 9)
In the front fork A, a damper leg 10 including a damper 20 and not including a suspension spring made of a metal spring and a spring leg 110 not including a damper and including a suspension spring 150 made of a metal spring are arranged in parallel.

(Damper leg 10) (FIGS. 1, 2 to 4)
As shown in FIGS. 1 and 2 to 4, the damper leg 10 is slid by sealing a vehicle body side tube (outer tube) 11 and an axle side tube (inner tube) 12 through bushes 13A and 13B and a seal member 13C. A single cylinder damper 20 is disposed inside the vehicle body side tube 11 and the axle side tube 12 so as to be freely movable. The damper 20 suspends the damper cylinder 21 at the center inside the vehicle body side tube 11, and inserts the piston 23 of the piston rod 22 erected at the center inside the axle side tube 12 into the damper cylinder 21. The outside of the cylinder 21 and the piston rod 22) is an oil reservoir chamber 24. In the oil reservoir chamber 24, the oil chamber 25 and the air chamber 26 are in contact via a free interface.

  The vehicle body side tube 11 is supported on the vehicle body side, and the axle side tube 12 is coupled to the axle. The upper end portion of the damper cylinder 21 is screwed and sealed to the upper end portion of the vehicle body side tube 11, and the upper opening end of the damper cylinder 21 is closed and sealed with a fork bolt 31.

  An axle bracket 32 is screwed and sealed to the lower end portion of the axle-side tube 12, and a lower end portion of the piston rod 22 is erected on the axle bracket 32 inside the axle-side tube 12. An oil lock collar 33 </ b> A is fixed on the bracket 32. A lower end portion of the piston rod 22 is screwed to a bottom bolt 32A that is engaged and sealed with the bottom portion of the axle bracket 32 from the outside, and is fixed by a lock nut 32B. The oil lock collar 33 </ b> A is clamped between the lower end surface of the axle tube 12 and the bottom of the axle bracket 32. The piston rod 22 is slidably supported by a bush 35 and a seal member 36 of a rod guide 34 screwed into a lower opening end of the damper cylinder 21 and is inserted into the damper cylinder 21. An oil lock piece 33B is provided on the outer periphery of the rod guide 34.

  The damper 20 includes a main valve device (extension-side damping force generation device) 40 and a sub-valve device (compression-side damping force generation device) 50. The damper 20 controls the expansion and contraction vibration of the vehicle body side tube 111 and the axle side tube 112 due to the absorption of the impact force by the suspension spring 150 of the spring leg 110 and the air spring by the damping force generated by the main valve device 40 and the sub valve device 50. Shake.

(Main valve device 40)
The main valve device 40 divides the inside of the damper cylinder 21 into a piston-side oil chamber 41A and a rod-side oil chamber 41B by the piston 23 at the upper end of the piston rod 22. The piston 23 includes an expansion-side damping valve 42A and includes an expansion-side flow passage 42 that connects the piston-side oil chamber 41A and the rod-side oil chamber 41B, and a compression-side attenuation valve (check valve) 43A. And a pressure side channel 43 communicating with the rod side oil chamber 41B.

(Sub-valve device 50)
The sub valve device 50 suspends a guide pipe 51 at the center of a fork bolt 31 provided at the upper opening end of the damper cylinder 21, and a sub piston 52 at the lower end of the guide pipe 51 is disposed relative to the piston 23 inside the damper cylinder 21. Then, the sub tank chamber 53 is partitioned and formed above the piston side oil chamber 41A. The sub-piston 52 is provided with a pressure-side damping valve 54A to connect the piston-side oil chamber 41A and the sub-tank chamber 53, and an extension-side damping valve (check valve) 55A to provide the piston-side oil chamber 41A and the sub-tank chamber. And an extension-side flow channel 55 that communicates with 53.

  The sub-valve device 50 is provided with a free piston 56 movably around the guide pipe 51 inside the damper cylinder 21, and a pressurizing spring 57 composed of a compression coil spring interposed between the free piston 56 and the fork bolt 31. Thus, the free piston 56 is urged toward the sub-piston 52 side.

  The sub valve device 50 brings the oil in the oil reservoir chamber 24 adhering to the outer periphery of the piston rod 22 into the damper cylinder 21 from the seal member 36, and increases the hydraulic pressure in the oil chambers 41A and 41B and the sub tank chamber 53. When the free piston 56 moves to the ascending end due to the increased hydraulic pressure, the oil hole 58 provided in the damper cylinder 21 communicates the sub tank chamber 53 with the air chamber 26 of the oil reservoir chamber 24, and the high pressure oil in the sub tank chamber 53 is discharged. Return to the oil reservoir chamber 24 side.

(Spring leg 110) (FIGS. 1, 5 to 7)
As shown in FIGS. 1 and 5-7, the spring leg 110 is slid by sealing a vehicle body side tube (outer tube) 111 and an axle side tube (inner tube) 112 via bushes 113A and 113B and a seal member 113C. Insert freely. The spring leg 110 suspends the guide cylinder 121 in the center of the vehicle body side tube 111, and the tip guide 123 of the guide rod 122 erected in the center of the axle side tube 112 is slidably inserted into the guide cylinder 121. is doing. The spring leg 110 has an oil reservoir chamber 124 outside the guide cylinder 121 and the guide rod 122. In the oil reservoir chamber 124, the oil chamber 125 and the air chamber 126 are in contact via a free interface. Further, the inside of the guide cylinder 121 is an air chamber 127.

  The vehicle body side tube 111 is supported on the vehicle body side, and the axle side tube 112 is coupled to the axle. The upper opening end of the vehicle body side tube 111 is closed and sealed with a cap 130 and a fork bolt 131. The cap 130 is screwed to the vehicle body side tube 111, and the fork bolt 131 is screwed to the cap 130. A guide cylinder 121 is connected to and suspended from the lower end of the cap 130.

  An axle bracket 132 is screwed and sealed to a lower end portion of the axle side tube 112, and a lower end portion of a guide rod 122 is erected on the axle bracket 132 inside the axle side tube 112, and an axle around the guide rod 122 is provided. An oil lock collar 133A is fixed on the bracket 132. A lower end portion of the guide rod 122 is screwed to a bottom bolt 132A that is engaged and sealed to the bottom portion of the axle bracket 132 from the outside, and is fixed by a lock nut 132B. The oil lock collar 133 </ b> A is clamped between the lower end surface of the axle tube 112 and the bottom of the axle bracket 132. The guide rod 122 is slidably supported by a bush 135 of a rod guide 134 that is screwed into the lower opening end of the guide cylinder 121, and is inserted into the guide cylinder 121. A guide 123 is screwed to the tip of a guide rod 122 inserted into the guide cylinder 121, and a rebound spring 136 is interposed between the guide 123 and the rod guide 134. An oil lock piece 133B is provided on the outer periphery of the rod guide 134.

  The spring leg 110 is equipped with a spring load adjusting device 140 around the fork bolt 131 and the guide cylinder 121. The spring load adjusting device 140 is inserted into the fork bolt 131 at the upper opening end of the vehicle body side tube 111 from the outside, sealed and pivotally supported, and the outer periphery of the operation unit 141 inserted inside the vehicle body side tube 111. A retaining plate 142 and an adjuster bolt 143 are provided in the axial direction along the axis. The operation unit 141 is fixedly screwed with the adjuster bolt 143 and is prevented from being detached from the fork bolt 131 via the retaining plate 142. A cylindrical adjuster nut 144 is screwed onto the adjuster bolt 143. Downward claws 144A are provided at a plurality of positions in the circumferential direction on the lower end side of the adjuster nut 144. It protrudes around the guide cylinder 121 suspended from the cap 130 through the hole. When the operation unit 141 is rotated from the outside with a sense of moderation at a certain rotation angle by the click mechanism 145 provided in the insertion part to the fork bolt 131, the adjuster nut 144 that is screwed with respect to the adjuster bolt 143 is prevented from rotating. Move up and down. The downward claw 144A of the adjuster nut 144 supports the upper spring receiver 148 via a spring seat 146 and a spring collar 147 provided around the guide cylinder 121.

  The spring leg 110 is a suspension spring made of a metal spring with the inner circumference of the vehicle body side tube 111 and the axle side tube 112 and the annular gap (oil reservoir chamber 124) between the outer circumference of the guide cylinder 121 and the guide rod 122 as a spring accommodating chamber 151. 150 is arranged in the spring accommodating chamber 151. The suspension spring 150 is interposed between the upper spring receiver 148 of the spring load adjusting device 140 and the lower spring receiver 149 formed of the outer peripheral portion of the oil lock collar 133A provided on the axle bracket 132. The suspension spring 150 is guided by the outer periphery of the guide cylinder 121 and expands and contracts along the inner periphery of the axle side tube 112. The initial load of the suspension spring 150 can be adjusted by adjusting the position of the adjuster nut 144 by the operation unit 141 of the spring load adjusting device 140.

  The spring leg 110 has an upper portion in the spring accommodating chamber 151 of the suspension spring 150 as an air chamber 126 and communicates with the air chamber 127 inside the guide cylinder 121. The operation unit 141 includes an air valve 128 that adjusts the enclosed air pressure of the air chambers 126 and 127. An air spring is formed by the air chamber 126 and the air chamber 127 that are compressed in the compression stroke of the spring leg 110. The guide 123 that moves up and down the air chamber 127 of the guide cylinder 121 includes an air flow path 123A that connects the upper and lower air chambers 127.

  In the spring leg 110, lubricating oil is loaded into the oil chamber 125 of the oil reservoir chamber 124 (spring accommodating chamber 151). The sliding part between the vehicle body side tube 111 and the axle side tube 112, the sliding part between the guide cylinder 121 and the guide rod 122, and the sliding part between the suspension spring 150, the axle side tube 112 and the guide cylinder 121 are lubricated.

  Accordingly, in the front fork A, the spring is caused by the damping force generated by the extension side damping valve 42A of the extension side damping force generator 40 and the compression side damping valve 54A of the compression side damping force generator 50 in the damper 20 of the damper leg 10. The expansion and contraction vibration of the vehicle body side tube 111 and the axle side tube 112 due to the absorption of the impact force by the suspension spring 150 of the leg 110 and the air spring (air chamber 126, 127) is suppressed.

  In the front fork A, the piston rod 22 of the damper leg 10 and the guide rod 122 of the spring leg 110 are made hollow to reduce the weight of the damper leg 10 and the spring leg 110. As shown in FIG. 6, the guide rod 122 (the piston rod 22 has the same structure) has both ends of the hollow portion sealed with plugs 122A.

  Further, in the front fork A, the vehicle body side tube 11 of the damper leg 10 and the vehicle body side tube 111 of the spring leg 110 have the same length and the same diameter (the same diameter) in order to balance the rigidity of the damper leg 10 and the spring leg 110. The piston rod 12 of the damper leg 10 and the guide rod 122 of the spring leg 110 have the same length and the same diameter (same thickness). Further, the damper cylinder 21 of the damper leg 10 and the guide cylinder 121 of the spring leg 110 have the same length and the same diameter (the same thickness), and the piston rod 22 of the damper leg 10 and the guide rod 122 of the spring leg 110 have the same length. , Have the same diameter (same thickness).

  Further, in the front fork A, in order to balance the rigidity of the damper leg 10 and the spring leg 110, the piston rod is provided on the damper cylinder 21 of the damper leg 10 in a front view of the front fork A (FIG. 1). The bush 35 of the rod guide 34 that inserts and supports 22 and the bush 135 of the rod guide 134 that is provided in the guide cylinder 121 of the spring leg 110 and that inserts and supports the guide rod 122 are positioned at the same height position. Also, a bush 13A provided on the vehicle body side tube 11 of the damper leg 10 for inserting and supporting the axle side tube 12 and a bush 113A provided on the vehicle body side tube 111 of the spring leg 110 for inserting and supporting the axle side tube 112. Are positioned at the same height position.

Therefore, the front fork A has the following effects.
(a) The spring leg 110 inserts the vehicle body side tube 111 and the axle side tube 112 into each other, the guide cylinder 121 is provided at the center inside the vehicle body side tube 111, and the guide rod provided at the center inside the axle side tube 112 A guide 123 of 122 is inserted into the guide cylinder 121, and a suspension spring 150 is interposed between the spring receiver 148 provided around the guide cylinder 121 inside the vehicle body side tube 111 and the axle side tube 112. Become. Accordingly, the guide cylinder 121 and the spring receiver 148 are opposed to each other in the axial direction and do not move relative to each other, and the distance between the guide cylinder 121 and the spring receiver 148 in the axial direction exceeds the maximum value of the extension stroke of the spring leg 110. It is not necessary to secure the length, and the degree of freedom in design is improved. In particular, the overall length of the spring leg 110 is reduced, and the length of the suspension spring 150 does not need to be longer than necessary.

  Further, the upper end of the suspension spring 150 is guided by the outer periphery of the guide cylinder 121 to suppress the torsion. Even if the upper end of the suspension spring 150 protrudes upward from the tip of the axle-side tube 112, the outer periphery of the suspension spring 150 that is restrained from bending is less likely to interfere with the tip of the axle-side tube 112. Friction, damage, generation of abrasion powder, and abnormal noise between the axle side tube 112 and the suspension spring 150 can be prevented.

  (b) In the spring leg 110, the guide cylinder 121 provided at the center inside the vehicle body side tube 111 does not contain a damping force generator or the like. Therefore, the spring load adjusting device 140 can be provided around the guide cylinder 121, and the operation portion 141 of the spring load adjusting device 140 can be provided outside the vehicle body side tube 111. The spring leg 110 can be equipped with a spring load adjusting device 140.

  (c) In front view of the front fork A, the piston 135 is provided on the bush 135 of the rod guide 134 that is provided on the guide cylinder 121 of the spring leg 110 to insert and support the guide rod 122 and the damper cylinder 21 of the damper leg 10. The bush 35 of the rod guide 34 for inserting and supporting the rod 22 is positioned at the same height position. The balance between the rigidity of the damper leg 10 and the spring leg 110 can be balanced, and the swing of the handle (yaw direction) at the time of disturbance input can be suppressed.

  (d) The body side tube 111 of the spring leg 110 and the body side tube 11 of the damper leg 10 have the same diameter, the axle side tube 112 of the spring leg 110 and the axle side tube 12 of the damper leg 10 have the same diameter, and the spring The guide cylinder 121 of the leg 110 and the damper cylinder 21 of the damper leg 10 have the same diameter, and the guide rod 122 of the spring leg 110 and the piston rod 22 of the damper leg 10 have the same diameter. The balance between the rigidity of the damper leg 10 and the spring leg 110 can be balanced, and the swing of the handle (yaw direction) at the time of disturbance input can be suppressed.

  The spring leg 110A shown in FIGS. 8 and 9 differs from the spring leg 110 in that an oil chamber 125 is provided in the lower part of the internal space surrounded by the vehicle body side tube 111 and the axle side tube 112, and an air chamber 126 is provided in the upper part. When provided, the air sealing case 160 is provided around the guide rod 122 below the oil level of the oil chamber 125. The air enclosure case 160 is formed of a hollow resin molded body that is fitted to the outer periphery of the guide rod 122. The upper and lower divided bodies 161 and 162 are joined together with the O-ring 163 interposed therebetween, and the tip small diameter portion 161A of the upper divided body 161 is formed. Is fitted to the outer periphery of the guide rod 122 via the O-ring 164 and is prevented from coming off by the retaining ring 165, and the tip small diameter portion 162 A of the lower divided body 162 is connected to the inner periphery of the guide rod 122 via the O-ring 166. Mating. Air is sealed inside the air sealing case 160.

  In the spring leg 110, the oil level can be raised by the volume of the air enclosure case 160 while reducing the amount of lubricating oil loaded in the oil chamber 125 of the spring leg 110A. Thereby, the compression ratio of the air chamber 126 can be increased and the air spring effect can be increased. Further, the oil scattering height range of the oil chamber 125 is also increased, and the friction reduction effect of the suspension spring 150 made of a metal spring can be increased.

Example 2 (FIGS. 11 to 16)
The front fork 200 includes a damper leg 10 including a damper 20 and not including a suspension spring made of a metal spring, and a spring leg 210 not including a damper and including a suspension spring 240 made of a metal spring.

  The damper leg 10 is the same as that shown in FIGS. 1 and 2 to 4 in the first embodiment, and a description thereof will be omitted.

(Spring leg 210) (FIGS. 11-14)
As shown in FIGS. 11 to 14, the spring leg 210 is slidable by sealing a vehicle body side tube (outer tube) 211 and an axle side tube (inner tube) 212 via bushes 213A, 213B and a seal member 213C. insert. The spring leg 210 suspends the guide cylinder 221 at the center inside the vehicle body side tube 211, and the tip guide 223 of the guide rod 222 erected at the center inside the axle side tube 212 is slidably inserted into the guide cylinder 221. is doing.

  The vehicle body side tube 211 is supported on the vehicle body side, and the axle side tube 212 is coupled to the axle. The upper opening end of the vehicle body side tube 211 is closed and sealed by a cap 230 and a fork bolt 231. The cap 230 is screwed to the vehicle body side tube 211, and the fork bolt 231 is screwed to the cap 230. A guide cylinder 221 is connected to the lower end of the cap 230 and is suspended.

  An axle bracket 232 is screwed and sealed to the lower end portion of the axle side tube 212, and the lower end portion of the guide rod 222 is erected on the axle bracket 232 inside the axle side tube 212. The lower end portion of the guide rod 222 is screwed to a bottom bolt 232A that is engaged and sealed with the bottom portion of the axle bracket 232 from the outside, and is fixed by a lock nut 232B. The guide rod 222 is slidably supported by a bush 235 of a rod guide 234 that is screwed into a lower opening end of the guide cylinder 221, and is inserted into the guide cylinder 221. A guide 223 is screwed onto the tip of a guide rod 222 inserted into the guide cylinder 221, and a rebound spring 236 is interposed between the guide 223 and the rod guide 234.

  The spring leg 210 has an annular gap between the inner circumference of the vehicle body side tube 211 and the axle side tube 212 and the outer circumference of the guide cylinder 221 and the guide rod 222 as a spring accommodating chamber 241, and a suspension spring 240 made of a metal spring is used as the spring accommodating chamber. 241. The suspension spring 240 is interposed between an upper spring receiver 242 fixed on the outer periphery of the guide cylinder 221 and a lower spring receiver 244 provided on a bottom piece 243 seated on the bottom surface of the axle bracket 232. Is done. The bottom piece 243 is clamped between the bottom surface of the axle bracket 232 and the lower end surface of the axle side tube 212 that is screwed to the axle bracket 232. The suspension spring 240 is guided by the outer periphery of the guide cylinder 221 and expands and contracts along the inner periphery of the axle side tube 212.

  The spring leg 210 includes an inner air spring chamber 250 in which the tip guide 223 of the guide rod 222 is defined inside the guide cylinder 221, and a vehicle body side tube 211 and an axle side tube 212 at least outside the inner air spring chamber 250 in the guide cylinder 221. And an outer air spring chamber 260 which is divided into two.

  The inner air spring chamber 250 is connected to a partition plate 251 screwed and fixed to the center of the fork bolt 231 inside the guide cylinder 221 on the side where the guide rod 222 does not exist, and a tip guide 223 of the guide rod 222. It is partitioned by being sandwiched. The inner air spring chamber 250 is hermetically sealed by a seal member 223A provided with the tip guide 223 with respect to the inner periphery of the guide cylinder 221 and a seal member 251A with the partition plate 251 provided with respect to the inner periphery of the guide cylinder 221. Is done.

  The air pressure in the inner air spring chamber 250 is adjusted by the inner air pressure adjusting unit 252. The inner air pressure adjusting unit 252 is an air valve attached to the center of the fork bolt 231 facing the outside. The inner air spring chamber is formed by holes 253 and 254 formed on the center axis of the fork bolt 231 and the partition plate 251. The air pressure in the inner air spring chamber 250 is adjusted. The inner air pressure adjusting unit 252 may be made of a rubber film that can be pierced by an injection needle of a pneumatic injector.

  The outer air spring chamber 260 inserts the guide rod 222 inside the space 260A in which the vehicle body side tube 211 and the axle side tube 212 are partitioned outside the guide cylinder 221 and the guide cylinder 221 on the side where the guide rod 222 exists. A space 260B is defined by being sandwiched by a rod guide 234 to be supported and a tip guide 223 of the guide rod 222, and communicated with the space 260A through a hole 261 provided in the guide cylinder 221. The aforementioned rebound spring 236 is disposed in the space 260B. The vehicle body side tube 211 and the axle side tube 212 slide in an airtight manner on the sliding portions via the above-described seal member 213C. The upper portion of the space 260 </ b> A is hermetically sealed by a seal member 230 </ b> A provided with the cap 230 with respect to the inner periphery of the vehicle body side tube 211 and a seal member 231 </ b> A with a fork bolt 231 provided with respect to the inner periphery of the cap 230. . The lower part of the space 260 </ b> A is provided with seal members 243 </ b> A and 243 </ b> B provided with the bottom piece 243 on the inner periphery of the axle-side tube 212 and the bottom surface of the axle bracket 232, and bottom bolts 232 </ b> A provided with the inner periphery of the axle bracket 232. It is hermetically sealed by the seal member 243C.

  Note that the outer air spring chamber 260 may be formed only of the space 260A. At this time, the space 260B does not communicate with the space 260A and can be released to the outside through the hollow portion 264 of the guide rod 222.

  The air pressure of the outer air spring chamber 260 is adjusted by the outer air pressure adjusting unit 262. The outer air pressure adjusting unit 262 is composed of an air valve attached to the central part facing the outside of the bottom bolt 232A, a hole 263 provided on the central axis of the bottom bolt 232A, a hollow part 264 of the guide rod 222, a guide The hole 265 provided in the rod 222 communicates with the space 260B, and consequently the space 260A, and adjusts the sealed air pressure of the outer air spring chamber 260 (spaces 260A, 260B). The outer air pressure adjusting unit 262 may be made of a rubber film that can be pierced by an injection needle of a pneumatic injector.

  The spring leg 210 forms an air spring by the inner air spring chamber 250 and the outer air spring chamber 260 which are compressed in the compression side process.

  The spring leg 210 can form an oil chamber in which lubricating oil is loaded at the lower part of the outer air spring chamber 260 (spring accommodating chamber 241). The sliding part between the vehicle body side tube 211 and the axle side tube 212, the sliding part between the guide cylinder 221 and the guide rod 222, and the sliding part between the suspension spring 240 and the axle side tube 212 and the guide cylinder 221 are lubricated.

  Therefore, in the front fork 200, the spring is caused by the damping force generated by the extension side damping valve 42A of the extension side damping force generator 40 and the compression side damping valve 54A of the compression side damping force generator 50 in the damper 20 of the damper leg 10. The expansion and contraction vibration of the vehicle body side tube 211 and the axle side tube 212 due to the absorption of impact force by the suspension spring 240 of the leg 210, the air spring of the inner air spring chamber 250, and the air spring of the outer air spring chamber 260 is damped.

  In the front fork 200, the piston rod 22 of the damper leg 10 and the guide rod 222 of the spring leg 210 are made hollow in order to reduce the weight of the damper leg 10 and the spring leg 210.

  In the front fork 200, in order to balance the rigidity of the damper leg 10 and the spring leg 210, the vehicle body side tube 11 of the damper leg 10 and the vehicle body side tube 211 of the spring leg 210 have the same length and the same diameter (same The piston rod 12 of the damper leg 10 and the guide rod 222 of the spring leg 210 have the same length and the same diameter (same thickness). The damper cylinder 21 of the damper leg 10 and the guide cylinder 221 of the spring leg 210 have the same length and the same diameter (same thickness), and the piston rod 22 of the damper leg 10 and the guide rod 222 of the spring leg 210 have the same length. , Have the same diameter (same thickness).

  Further, in the front fork 200, in order to balance the rigidity of the damper leg 10 and the spring leg 210, the piston rod is provided on the damper cylinder 21 of the damper leg 10 in a front view of the front fork 200 (FIG. 11). The bush 35 of the rod guide 34 that inserts and supports the rod 22 and the bush 235 of the rod guide 234 that is provided on the guide cylinder 221 of the spring leg 210 and inserts and supports the guide rod 222 are positioned at the same height position. Also, a bush 13A provided on the vehicle body side tube 11 of the damper leg 10 to insert and support the axle side tube 12, and a bush 213A provided on the vehicle body side tube 211 of the spring leg 210 to insert and support the axle side tube 212. Are positioned at the same height position.

Therefore, according to the front fork 200, the following effects can be obtained.
(a) The spring leg 210 inserts the vehicle body side tube 211 and the axle side tube 212 into each other, the guide cylinder 221 is provided at the center inside the vehicle body side tube 211, and the guide rod provided at the center inside the axle side tube 212 A guide 223 of 222 is inserted into the guide cylinder 221, and a suspension spring 240 is interposed between the spring receiver 242 provided around the guide cylinder 221 inside the vehicle body side tube 211 and the axle side tube 212. Become. Therefore, the guide cylinder 221 and the spring receiver 242 are not opposed to each other in the axial direction and do not move relative to each other, and the maximum distance between the extension strokes of the spring legs 210 exceeds the axial distance between the guide cylinder 221 and the spring receiver 242. It is not necessary to secure the length, and the degree of freedom in design is improved. In particular, the overall length of the spring leg 210 is reduced, and the length of the suspension spring 240 does not need to be longer than necessary.

  Further, the upper end of the suspension spring 240 is guided by the outer periphery of the guide cylinder 221 to suppress the torsion. Even if the upper end of the suspension spring 240 protrudes upward from the tip of the axle-side tube 212, the outer periphery of the suspension spring 240 that is restrained from bending is less likely to interfere with the tip of the axle-side tube 212. Friction, damage, generation of wear powder, and abnormal noise between the axle side tube 212 and the suspension spring 240 can be prevented.

  (b) In front view of the front fork 200, a piston provided on the bushing 235 of the rod guide 234 provided on the guide cylinder 221 of the spring leg 210 for inserting and supporting the guide rod 222 and on the damper cylinder 21 of the damper leg 10 The bush 35 of the rod guide 34 for inserting and supporting the rod 22 is positioned at the same height position. The balance between the rigidity of the damper leg 10 and the spring leg 210 can be balanced, and the swinging (yaw direction) of the handle during disturbance input can be suppressed.

  (c) The body side tube 211 of the spring leg 210 and the body side tube 11 of the damper leg 10 have the same diameter, the axle side tube 212 of the spring leg 210 and the axle side tube 12 of the damper leg 10 have the same diameter, and the spring The guide cylinder 221 of the leg 210 and the damper cylinder 21 of the damper leg 10 have the same diameter, and the guide rod 222 of the spring leg 210 and the piston rod 22 of the damper leg 10 have the same diameter. The balance between the rigidity of the damper leg 10 and the spring leg 210 can be balanced, and the swinging (yaw direction) of the handle during disturbance input can be suppressed.

  (d) The spring leg 210 includes an inner air spring chamber 250 in which the guide 223 of the guide rod 222 is defined inside the guide cylinder 221, and the vehicle body side tube 211 and the axle side tube 212 are at least the inner air spring chamber in the guide cylinder 221. And an outer air spring chamber 260 that divides the outer side of 250. The air chamber provided in the inner space surrounded by the vehicle body side tube 211 and the axle side tube 212 in the spring leg 210 is divided into an inner air spring chamber 250 and an outer air spring chamber 260 inside and outside the guide cylinder 221. Each of the inner air spring chamber 250 and the outer air spring chamber 260 is made into a small space corresponding to the two parts and has a high compression ratio. The spring force F1 of the air spring of the inner air spring chamber 250 and the outer air spring chamber The spring force F2 of the air spring 260 is increased, and the entire air spring force (F1 + F2) of the spring leg 210 can be increased.

  The spring force of the suspension spring 240 made of a metal spring of the spring leg 210 can be reduced by the amount that can increase the overall air spring force of the spring leg 210, and as a result, the wire diameter of the suspension spring 240 can be reduced and the weight can be reduced.

  (e) The air spring force (F1 + F2) of the entire spring leg 210 is divided into the spring force F1 of the inner air spring chamber 250 and the spring force F2 of the outer air spring chamber 260 by the air pressure of the inner air spring chamber 250. The overall air spring force (F1 + F2) can be increased while reducing the air pressure in the outer air spring chamber 260. As a result, a constant air spring force characteristic can be obtained while reducing the sealing load exerted on the seal members 223A, 251A of the inner air spring chamber 250 and the seal members 213C, 230A, 231A, 243A, 243B, 243C of the outer air spring chamber 260. It can be secured.

  (f) The air springs of the inner air spring chamber 250 and the outer air spring chamber 260 are used in combination with the suspension spring 240 whose spring leg 210 is made of a metal spring. Therefore, the spring force in the latter half of the expansion / contraction stroke can be increased by the rise of the spring force of the air springs in the inner air spring chamber 250 and the outer air spring chamber 260, and a spring force characteristic with struts can be obtained. The spring force in the initial to intermediate range of the expansion / contraction stroke is ensured by the suspension spring 240, so that the spring force characteristic with good ride comfort can be obtained without being moderately increased.

  (g) The air springs of the inner air spring chamber 250 and the outer air spring chamber 260 are used in combination with the suspension spring 240 whose spring leg 210 is made of a metal spring. Therefore, even if the air in the inner air spring chamber 250 and the outer air spring chamber 260 escapes, the load for about one passenger can be supported by the suspension spring 240 and can continue to travel.

  (h) Since the spring leg 210 does not incorporate a damper, the air in the inner air spring chamber 250 and the outer air spring chamber 260 does not rise due to the oil temperature of the damper, and the inner air spring chamber 250 And the spring force characteristic of the air spring of the outer air spring chamber 260 is stabilized without changing greatly.

  (i) The spring leg 210 includes an inner air pressure adjusting unit 252 for adjusting the air pressure of the inner air spring chamber 250 and an outer air pressure adjusting unit 262 for adjusting the air pressure of the outer air spring chamber 260. By adjusting the air pressure of the inner air spring chamber 250 and the air pressure of the outer air spring, the entire air spring force characteristic of the spring leg 210 can be variously changed.

  The spring leg 210 </ b> A shown in FIGS. 15 and 16 is different from the spring leg 210 in that a spring load adjusting device 270 is provided around the fork bolt 231 and the guide cylinder 221.

  The spring load adjusting device 270 includes a seal member 271 </ b> A that is fixedly provided by screwing the fork plate 271 onto the cap 230, and the fork plate 271 is hermetically sealed with respect to the inner periphery of the cap 230. The fork bolt 231 is rotatably supported on the fork plate 271, and the fork bolt 231 is provided with a seal member 231 </ b> A that is hermetically sealed with respect to the inner periphery of the fork plate 271. The fork bolt 231 includes a flange portion 231 </ b> F that comes into contact with the inner surface of the fork plate 271 from below, and a lower end surface that comes into contact with the reduced diameter portion of the cap 230 from above, so that the gap between the cap 230 and the fork plate 271 is provided. It is held in the axial direction and pivotally supported on the inner periphery of the fork plate 271.

  In the spring load adjusting device 270, a cylindrical adjuster nut 272 is screwed onto the outer peripheral male screw portion directly below the flange 231F of the fork bolt 231, and the downward claw 272A of the adjuster nut 272 passes through the rotation stop hole provided in the cap 230, and the cap It protrudes toward the periphery of the guide cylinder 221 suspended by 230. When the fork bolt 231 is rotated from the outside with a sense of moderation at a certain rotation angle by a click mechanism 273 provided at the insertion portion to the fork plate 271, the adjuster nut 272 that is screwed with respect to the fork bolt 231 is prevented from rotating. Move up and down. The downward claw 272 </ b> A of the adjuster nut 272 supports the upper spring receiver 276 via a spring seat 274 and a spring collar 275 provided around the guide cylinder 221. The upper spring receiver 276 replaces the upper spring receiver 242 in the spring leg 210, and the suspension spring 240 is interposed between the lower spring receiver 244 and the bottom piece 243 seated on the bottom surface of the axle bracket 232. To become.

  By adjusting the position of the adjuster nut 272 by rotating the fork bolt 231 of the spring load adjusting device 270, the initial load of the suspension spring 240 can be adjusted.

  In the spring leg 210A, the guide cylinder 221 provided at the center inside the vehicle body side tube 211 does not contain a damping force generator or the like. Therefore, the spring load adjusting device 270 can be provided around the guide cylinder 221, and the fork bolt 231 as an operation portion of the spring load adjusting device 270 can be provided outside the vehicle body side tube 211. A spring load adjusting device 270 can be provided on the spring leg 210A.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention. It is included in the present invention. For example, in the damper leg, the vehicle body side tube may be an inner tube, the axle side tube may be an outer tube, the damper cylinder may be provided on the axle side tube, and the piston rod may be provided on the vehicle body side tube.

  In the spring leg, the vehicle body side tube may be an inner tube and the axle side tube may be an outer tube.

  The present invention is a front fork in which a spring leg with a built-in suspension spring made of a metal spring without a built-in damper and a damper leg with a built-in damper and a built-in suspension spring made of a metal spring arranged in parallel, The spring leg inserts the vehicle body side tube and the axle side tube into each other, the guide cylinder is provided at the center inside the vehicle body side tube, and the guide rod guide provided at the center inside the axle side tube is inserted into the guide cylinder. Thus, a suspension spring is interposed between the spring receiver provided around the guide cylinder inside the vehicle body side tube and the axle side tube. Thereby, in the front fork in which the damper leg and the spring leg are arranged in parallel, the spring leg can be made compact.

A, 200 Front fork 10 Damper leg 11 Car body side tube 12 Axle side tube 13A Bush 20 Damper 21 Damper cylinder 22 Piston rod 23 Piston 34 Rod guide 35 Bush 110, 110A, 210, 210A Spring leg 111, 211 Car body side tube 112, 212 Axle tube 113A, 213A Bush 121, 221 Guide cylinder 122, 222 Guide rod 123, 223 Guide 124 Oil reservoir 125 Oil chamber 126 Air chamber 127 Air chamber 134, 234 Rod guide 135, 235 Bush 140, 270 Spring load adjustment Apparatus 141,231 Operation part 148,242 Spring receiver 150,240 Suspension spring 160 Air enclosure case 250 Inner air spring chamber 252 Inner air pressure adjustment part 260 Outer air Root chamber 262 outside air pressure adjustment section

Claims (7)

A front fork in which a spring leg with a built-in suspension spring made of a metal spring without a built-in damper and a damper leg with a built-in damper and a built-in suspension spring made of a metal spring are arranged in parallel,
Spring leg
The vehicle body side tube and the axle side tube are inserted into each other.
A front fork in which a suspension spring is interposed between a spring holder provided around the guide cylinder inside the vehicle body side tube and the axle side tube.   2. The spring load adjusting device according to claim 1, wherein a spring load adjusting device capable of displacing the spring receiver along an axial direction of the vehicle body side tube by an operation portion provided outside the vehicle body side tube in the spring leg is provided around the guide cylinder. Front fork. An oil chamber is provided in the lower part of the internal space surrounded by the vehicle body side tube and the axle side tube in the spring leg, and an air chamber is provided in the upper part.
The front fork according to claim 1 or 2, wherein an air-filled case is provided around a guide rod below the oil level of the oil chamber. The damper leg inserts the vehicle body side tube and the axle side tube into each other, the damper cylinder is provided at the center inside the vehicle body side tube, and the piston of the piston rod provided at the center inside the axle side tube is inserted into the damper cylinder. And
A rod guide bush provided in the guide cylinder of the spring leg for inserting and supporting the guide rod in a front view of the front fork, and a bush of the rod guide provided in the damper cylinder of the damper leg for inserting and supporting the piston rod. The front forks according to claim 1, which are positioned at the same height position. The spring leg body side tube and the damper leg body side tube have the same diameter, and the spring leg axle side tube and damper leg axle side tube have the same diameter,
5. The front fork according to claim 4, wherein the spring leg guide cylinder and the damper leg damper cylinder have the same diameter, and the spring leg guide rod and the damper leg piston rod have the same diameter.   An inner air spring chamber in which the guide of the guide rod is defined inside the guide cylinder; and an outer air spring chamber in which the vehicle body side tube and the axle side tube are defined at least outside the inner air spring chamber in the guide cylinder. A front fork according to any one of claims 1 to 5.   7. The front according to claim 6, wherein the spring leg includes an inner air pressure adjusting portion for adjusting the air pressure of the inner air spring chamber and an outer air pressure adjusting portion for adjusting the air pressure of the outer air spring chamber. fork.

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