JP2007076634A - Vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle capable of sufficiently absorbing impact in a width direction of a vehicle body applied and caused by recession/projection of a ground surface. <P>SOLUTION: The vehicle (motorcycle 1) is provided with a head pipe 2 for supporting a front wheel 8; a main frame 3 for supporting a rear wheel 13 mounted with the head pipe 2 turnably around a center line L1 of a shaft part 2a extending in a longitudinal direction; a spring member 16 for absorbing impact at turning of the head pipe 2 relative to the main frame 3 and arranged at a position other than a position on the center line L1 extending in the longitudinal direction; and an actuator 17 for spring constant adjustment for changing the spring constant relative to a deflection direction of the spring member 16 according to a vehicle speed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle, and more particularly to a vehicle including a front frame that supports front wheels and a rear frame that supports rear wheels.

  2. Description of the Related Art Conventionally, a motorcycle (vehicle) including a front frame that supports front wheels and a rear frame that supports rear wheels is known. In such a conventional motorcycle, a front fork having a shock absorbing function in the vertical direction is provided at a portion supporting the front wheel of the front frame. This allows the front fork to absorb the impact in the vertical direction when the front wheel is not inclined and the front wheel is subjected to a vertical impact due to the unevenness of the ground during straight running. is there.

  However, the above-described conventional front fork of a motorcycle can absorb an impact in the vertical direction (vertical direction) of the vehicle body applied to the front wheels, while absorbing an impact in the width direction (lateral direction) of the vehicle body applied to the front wheels. It is difficult. For this reason, when turning with the vehicle body (front wheel) tilted, it is difficult to absorb the impact if the front wheel is subjected to an impact in the width direction of the vehicle body due to unevenness of the ground. There is an inconvenience.

  On the other hand, a motorcycle has been proposed in which a front frame that supports front wheels is configured to be rotatable with respect to a rear frame that supports rear wheels (see, for example, Patent Document 1). In the motorcycle proposed in Patent Document 1, the front frame that supports the front wheels is configured to be rotatable with respect to the rear frame that supports the rear wheels, so that the vehicle turns with the vehicle body (front wheels) tilted. When the front wheel is subjected to an impact in the width direction of the vehicle body due to the unevenness of the ground, the front frame that supports the front wheel rotates relative to the rear frame that supports the rear wheel. Since it can move in the width direction of the vehicle body (the direction in which the impact is applied), it is possible to moderate the impact in the width direction of the vehicle body to some extent.

JP-A-63-222987

  However, in the structure proposed in Patent Document 1, when an impact in the width direction of the vehicle body is applied to the front wheels, the front wheels only move in the direction of the impact (the width direction of the vehicle body) and alleviate the impact. Since the structure does not actively absorb the impact in the width direction of the vehicle body, there is a problem that it is difficult to sufficiently absorb the impact in the width direction of the vehicle body.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to sufficiently absorb the impact in the width direction of the vehicle body caused by unevenness of the ground during turning. It is to provide a vehicle that can.

Means for Solving the Problems and Effects of the Invention

  A vehicle according to an aspect of the present invention includes a front frame that supports a front wheel, a rear frame that supports a rear wheel, and is rotatably attached to an axis extending in the front-rear direction, and a rear of the front frame. A shock absorbing member that absorbs shock when rotating with respect to the frame and is arranged at a position other than on the axis extending in the front-rear direction, and a spring constant for changing the spring constant in the bending direction of the shock absorbing member according to the running state Changing means.

  In the vehicle according to this aspect, as described above, the rear frame is provided so that the front frame can be rotated around the axis extending in the front-rear direction, and the shock is absorbed when the front frame is rotated with respect to the rear frame. By providing the absorbing member at a position other than on the axis extending in the front-rear direction, the front frame is moved rearward so that the front wheel moves in the width direction of the vehicle body along the unevenness of the ground when the vehicle body is tilted. It can be rotated with respect to the frame, and at the time of the rotation, the impact absorbing member provided at a position other than on the axis extending in the front-rear direction actively absorbs the impact in the width direction (lateral direction) of the vehicle body. Can do. Thereby, the impact in the width direction (lateral direction) of the vehicle body due to the unevenness of the ground can be sufficiently absorbed. Further, by providing a spring constant changing means for changing the spring constant with respect to the bending direction of the shock absorbing member according to the traveling state, the spring constant with respect to the bending direction of the shock absorbing member is set to a spring constant suitable for the traveling state. Therefore, the impact can be absorbed by the impact absorbing member set to the optimum spring constant corresponding to the traveling state.

  In the vehicle according to the above aspect, the shock absorbing member is preferably controlled by controlling the vehicle speed detecting means for detecting the vehicle speed and the spring constant changing means based on the vehicle speed corresponding to the detection output of the vehicle speed detecting means. And a first control means for controlling a spring constant with respect to the bending direction. If comprised in this way, since the spring constant with respect to the bending direction of an impact-absorbing member can be changed by the 1st control means according to a vehicle speed, the impact set to the optimal spring constant according to the vehicle speed easily. The impact can be absorbed by the absorbing member.

  In the vehicle including the vehicle speed detecting means and the first control means, the first control means preferably has a spring constant with respect to the direction in which the shock absorbing member bends as the vehicle speed corresponding to the detection output of the vehicle speed detecting means increases. The spring constant changing means is controlled so as to increase. With this configuration, when the vehicle speed is low, the spring constant with respect to the bending direction of the shock absorbing member can be reduced. Therefore, when the vehicle is turned with the vehicle body tilted, the rear frame Can be rotated more greatly. Thereby, since a larger steering angle can be given to the rear wheels supported by the rear frame, the turning radius can be increased. As a result, stability can be improved. Also, when the vehicle speed is high, the spring constant with respect to the deflection direction of the shock absorbing member can be increased, so that the rotational frequency of the wheels (front wheels and rear wheels) becomes higher as the vehicle speed increases. In addition, the shock absorbing member can be suppressed from resonating. In addition, when the vehicle speed is high, the spring constant with respect to the bending direction of the shock absorbing member can be increased, so that when the vehicle body is tilted, the amount of rotation of the rear frame relative to the front frame can be reduced. it can. Thereby, a small rudder angle can be given to the rear wheel supported by the rear frame. That is, when the vehicle speed is high, the steering angle amount necessary for turning is small, so that a steering angle suitable for the vehicle speed can be given.

  In this case, preferably, as the vehicle speed corresponding to the detection output of the vehicle speed detecting means increases, the first control means increases the spring constant with respect to the deflection direction of the shock absorbing member continuously or stepwise. Thus, the spring constant changing means is controlled. If comprised in this way, it can control by a 1st control means so that a spring constant may increase easily with the increase in a vehicle speed.

  In the vehicle according to the aforementioned aspect, the spring constant changing means preferably includes an actuator. If comprised in this way, the spring constant with respect to the bending direction of an impact-absorbing member can be easily changed using an actuator.

  In a vehicle in which the spring constant changing means includes an actuator, preferably, the shock absorbing member includes a spring member, and the actuator is attached to at least one of the one end and the other end of the spring member. If comprised in this way, the spring constant with respect to the bending direction of a spring member can be directly changed with an actuator, Therefore The spring constant with respect to the bending direction of a spring member can be controlled with high precision.

  In the vehicle according to the above aspect, the shock absorbing member preferably includes a spring member disposed between the front frame and the rear frame and at a position other than on the axis extending in the front-rear direction. If comprised in this way, when a front frame is rotated with respect to a back frame, the impact of a rotation direction (width direction of a vehicle body) can fully be absorbed with the bending force of a spring member.

  In a vehicle including a spring member in which the shock absorbing member is disposed at a position other than a straight line extending in the front-rear direction, preferably, the center line of the spring member is disposed substantially in parallel along the axis. If comprised in this way, when the back frame is arrange | positioned along an axis line, since a spring member can be arrange | positioned along a back frame, the part which arrange | positions a spring member can be saved in space. .

  In a vehicle including a spring member in which the impact absorbing member is disposed at a position other than a straight line extending in the front-rear direction, the center line of the spring member is preferably disposed so as to intersect the axis. If comprised in this way, when the front frame is arrange | positioned so that it may cross | intersect with an axis line, since a spring member can be arrange | positioned along a front frame, the part which arrange | positions a spring member can save space. can do.

  In the vehicle including the spring member that is disposed at a position other than the straight line in which the shock absorbing member extends in the front-rear direction, the spring member preferably has a flat plate-shaped portion that is a portion where stress due to bending occurs. If comprised in this way, the spring constant with respect to a bending direction can be easily changed by changing the cross-sectional secondary moment regarding the axis | shaft orthogonal to the bending direction of the flat plate-shaped part of a spring member.

  In the vehicle in which the spring member has a flat plate-shaped portion, the spring constant of the spring member is preferably changed by changing the angle of the flat plate-shaped portion with respect to the bending direction by the spring constant changing means. If comprised in this way, since the cross-sectional secondary moment regarding the axis | shaft orthogonal to the bending direction of a flat plate shape part can be easily changed by changing the angle of the flat plate shape part with respect to a bending direction, it is easy. In addition, the spring constant can be changed with respect to the bending direction.

  In a vehicle including a spring member arranged at a position other than a straight line in which the impact absorbing member extends in the front-rear direction, preferably, one end of the spring member is attached to the front frame, and the other end of the spring member Is attached to the rear frame. If comprised in this way, when a front frame is rotated with respect to a back frame, an impact can be fully absorbed easily with the bending force of a spring member.

  In the vehicle according to the above aspect, it is preferable that the vehicle further includes a damping unit for damping the rotation of the front frame relative to the rear frame, and a damping force changing unit for changing the damping force of the damping unit according to the traveling state. Prepare. If comprised in this way, when an impact is absorbed by an impact-absorbing member when a front frame rotates with respect to a back frame, the vibration of an impact-absorbing member consisting of a spring member or the like can be attenuated by an attenuation means. . Thereby, the convergence property at the time of impact absorption by the impact absorbing member can be improved. The damping means further includes damping means for damping the rotation of the front frame with respect to the rear frame, and damping force changing means for changing the damping force of the damping means according to the traveling state. Can be changed to a damping force suitable for the running state, so that an optimum damping force corresponding to the running state can be obtained.

  In a vehicle including the damping means and the damping force changing means, preferably, by controlling the damping force changing means based on the vehicle speed detecting means for detecting the vehicle speed and the vehicle speed corresponding to the detection output of the vehicle speed detecting means. And a second control means for controlling the damping force of the damping means. If comprised in this way, since the damping force of a damping means can be changed according to a vehicle speed by a 2nd control means, it can set to the optimal damping force according to a vehicle speed easily.

  In the vehicle including the vehicle speed detection means and the second control means, the second control means is preferably configured such that the damping force of the damping means increases as the vehicle speed corresponding to the detection output of the vehicle speed detection means increases. In addition, the damping force changing means is controlled. With this configuration, when the vehicle speed is low, the force (damping force) against the rotation when the front frame rotates with respect to the rear frame can be reduced, so that the front frame can be used when absorbing the impact. Can be quickly rotated with respect to the rear frame. Thereby, an impact can be absorbed more fully. Also, when the vehicle speed is high, the damping force of the damping means can be increased, so that the impact in the width direction (lateral direction) of the vehicle body applied due to unevenness of the ground increases as the vehicle speed increases. In addition, the vibration of the shock absorbing member can be sufficiently damped by the damping means. Thereby, the convergence property at the time of impact absorption by the impact absorbing member can be sufficiently improved.

  In the vehicle according to the aforementioned aspect, the extension line of the axis extending in the front-rear direction preferably passes near the contact point between the rear wheel and the ground. With this configuration, when the rear frame rotates with respect to the front frame, the rear wheel rotates about the vicinity of the contact point with the ground, thereby suppressing the rear wheel from sliding on the ground. Can do.

  In the vehicle according to the above aspect, the vehicle preferably further includes a bearing that is disposed between the front frame and the rear frame and rotatably supports the front frame and the rear frame. If comprised in this way, a front frame can be smoothly rotated to the surroundings of the axis line extended in the front-back direction with respect to a back frame with a bearing.

  In the vehicle according to the above aspect, the center of gravity is preferably located at a portion other than the extension line of the axis extending in the front-rear direction. With this configuration, by tilting the vehicle body at the time of turning, a moment due to the center of gravity can be generated around the axis extending in the front-rear direction, so that the rear frame can be easily rotated with respect to the front frame. it can.

  In the vehicle according to the above aspect, the axis extending in the front-rear direction preferably extends downward in the rear of the front frame. With this configuration, for example, when there is a center of gravity that combines the driver and the vehicle on the upper side of the axis extending in the front-rear direction, when turning leftward, the vehicle body is tilted to the left with respect to the vertical direction. By doing so, the rear wheel rotates around an axis extending in the rearward downward direction (backward obliquely downward direction), so that the front side of the rear wheel moves slightly to the left of the rear side of the rear wheel. Thereby, since a turning radius can be enlarged, stability can be improved.

  The vehicle according to the above aspect preferably further includes a regulating member for regulating an angle at which the front frame rotates with respect to the rear frame. If comprised in this way, it can prevent that a front frame rotates too much with respect to a back frame.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a side view showing the overall structure of a motorcycle according to an embodiment of the present invention. FIG. 2 is a side view of the periphery of the head pipe of the motorcycle according to the embodiment shown in FIG. 3 to 11 are diagrams for explaining the detailed structure of the motorcycle according to the embodiment shown in FIG. In the present embodiment, a motorcycle will be described as an example of the vehicle of the present invention. In the figure, FWD indicates the front in the traveling direction of the motorcycle. Hereinafter, the structure of a motorcycle according to an embodiment of the present invention will be described in detail with reference to FIGS.

  In the motorcycle 1 according to the embodiment of the present invention, a main frame 3 is disposed behind the head pipe 2 as shown in FIG. The head pipe 2 is an example of the “front frame” in the present invention, and the main frame 3 is an example of the “rear frame” in the present invention. The main frame 3 includes an upper frame portion 3a extending rearward from the upper side and a lower frame portion 3b extending rearward from the lower side. The rear part of the upper frame part 3 a and the rear part of the lower frame part 3 b are connected by a pivot shaft support member 4. A seat rail 5 is connected to the main frame 3. A backstay 6 is connected between the rear portion of the upper frame portion 3 a of the main frame 3 and the rear end portion of the seat rail 5. The head pipe 2, the main frame 3, the pivot shaft support member 4, the seat rail 5 and the back stay 6 constitute a vehicle body frame.

  A pair of front forks 7 having suspensions for absorbing impacts in the vertical direction are disposed below the head pipe 2. A front wheel 8 is rotatably attached to the lower ends of the pair of front forks 7.

  Here, in the present embodiment, the rotational shaft of the front wheel 8 is provided with a rotational speed sensor 9 for detecting the rotational speed of the front wheel 8. Further, as shown in FIG. 3, the rotation speed sensor 9 is configured so that a rotation speed signal is output to the control unit 10 described later. The rotation speed sensor 9 is an example of the “vehicle speed detection unit” in the present invention, and the control unit 10 is an example of the “first control unit” and the “second control unit” in the present invention. A front fender 11 is disposed above the front wheel 8 so as to cover the front wheel 8 as shown in FIG.

  Here, in the present embodiment, as shown in FIG. 2, a cylindrical shaft portion 2 a protruding downward in the rear direction is integrally formed at the rear portion of the head pipe 2. In addition, the main frame 3 is provided with a concave shaft insertion portion 3 c that is inserted into the shaft portion 2 a of the head pipe 2. An angular bearing 12 is disposed between the outer peripheral surface of the shaft portion 2 a of the head pipe 2 and the inner peripheral surface of the shaft insertion portion 3 c of the main frame 3. Thereby, the head pipe 2 can be rotated with respect to the main frame 3 around the center line L1 extending in the front-rear direction of the shaft portion 2a. In this case, by using the angular bearing 12, the rigidity in the direction (thrust direction) along the center line L1 extending in the front-rear direction and the center line L1 extending in the front-rear direction at the connecting portion of the head pipe 2 and the main frame 3 Both the rigidity in the vertical direction (radial direction) can be ensured. The center line L1 of the shaft portion 2a of the head pipe 2 is an example of the “axis” in the present invention, and the angular bearing 12 is an example of the “bearing” in the present invention. Further, the angular bearing 12 is arranged such that the central axis thereof is substantially the same as the central line L1 extending in the front-rear direction of the shaft portion 2a of the head pipe 2. Further, as shown in FIG. 1, the extension line of the center line L1 extending in the front-rear direction extends downward in the rear direction (backward obliquely downward direction) and passes near the contact point between the rear wheel 13 and the ground 100. Is formed. In addition, the center of gravity G (see FIG. 1) of the motorcycle 1 is arranged above the extension line of the center line L1 when the driver is not in the vehicle. As shown in FIG. 2, a thrust washer 14 and a rubber dust seal 15 are disposed between the head pipe 2 and the front portion of the main frame 3. The dust seal 15 has a function of preventing dust and the like from entering the thrust washer 14 and the angular bearing 12 from the gap between the head pipe 2 and the front portion of the main frame 3.

  Moreover, in this embodiment, as shown in FIG. 2, the head pipe 2 and the main frame 3 are connected via the spring member 16 which has an impact absorption function. The spring member 16 is an example of the “impact absorbing member” in the present invention. The spring member 16 is made of spring steel. Specifically, a pillow ball 16 a is provided on one end side of the spring member 16. The pillow ball 16a is rotatably attached to a support portion 2b formed on the upper portion of the head pipe 2. Thereby, the one end side of the spring member 16 is rotated integrally with the shaft portion 2a of the head pipe 2 around the center line L1. A bolt portion 16c is inserted and fixed in the insertion hole 16b of the pillow ball 16a.

  In the present embodiment, the tip end portion of the shaft portion 17a of the spring constant adjusting actuator 17 made of a servo motor is press-fitted into the press-fitting hole 16d (see FIG. 4) on the other end side of the spring member 16 and fixed. Yes. The spring constant adjusting actuator 17 is an example of the “spring constant changing means” and “actuator” in the present invention. As shown in FIG. 3, the spring constant adjusting actuator 17 has a spring member 16 centered on a center line L <b> 2 (see FIG. 2) based on a spring member rotation control signal input from the control unit 10. It has a function to rotate the amount. Further, the spring constant adjusting actuator 17 has a function of outputting a spring member rotation position signal representing the rotation position of the spring member 16 around the center line L2 to the control unit 10.

  Further, the other end portion 16e of the spring member 16 has a substantially cylindrical shape as shown in FIG. As shown in FIG. 2, the other end portion 16e is arranged such that its central axis is substantially the same as the center line L2. The other end portion 16e is attached to a recess 3d (see FIGS. 1 and 2) formed in the upper frame portion 3a of the main frame 3 by a cap 40 and a bolt 41 so as to be rotatable about the center line L2. ing. Thereby, since the other end part 16e can be arrange | positioned in the recessed part 3d of the main frame 3, it becomes possible to save space in the part which arrange | positions the spring member 16. FIG.

  Moreover, in this embodiment, as shown in FIG. 4, the center part 16f arrange | positioned between the pillow ball 16a and the other end part 16e of the spring member 16 has a flat plate shape made of spring steel having a thickness of about 1 mm. In addition, it has a function of generating stress by bending. The central portion 16f is an example of the “flat plate portion” in the present invention.

  Further, in the present embodiment, as shown in FIG. 5, the spring constant 16 is rotated about the center line L2 using the spring constant adjusting actuator 17, so that the spring constant with respect to the bending direction (left-right direction) is obtained. Can be adjusted. Specifically, the spring member 16 is configured to be rotatable within a range of about 90 degrees by an actuator 17 for adjusting the spring constant. For example, as shown in FIG. 5 (1), the spring member 16 is set in a state in which the spring member 16 is not rotated by the spring constant adjusting actuator 17 (the rotation position of the spring member 16 is approximately 0 degrees). In this case, since the cross-sectional secondary moment with respect to the axis orthogonal to the bending direction (left-right direction) of the center portion 16f having the flat plate shape of the spring member 16 can be minimized, the spring member 16 It is possible to make the spring constant of the smallest value. For example, as shown in FIG. 5 (3), the spring member 16 is rotated about 90 degrees by the spring constant adjusting actuator 17 (the rotation position of the spring member 16 is about 90 degrees). In the state of the degree), it is possible to make the cross-sectional secondary moment about the axis orthogonal to the bending direction (left-right direction) of the central portion 16f to the largest value. It is possible to make the constant the largest value. Further, when the spring member 16 is rotated to the rotation position as shown in (2) of FIG. 5 by the spring constant adjusting actuator 17, it is orthogonal to the bending direction (left-right direction) of the central portion 16f. The cross-sectional secondary moment with respect to the axis to be rotated is shown in FIG. 5 (1) (the rotational position of the spring member 16 is about 0 degrees) and the cross-sectional secondary moment is shown in (3) of FIG. The spring constant of the spring member 16 is shown in (1) of FIG. 5 because it can be set to a value between the cross-sectional secondary moments in the state (the rotational position of the spring member 16 is about 90 degrees). It is possible to set a value between the spring constant in the state shown and the spring constant in the state shown in (3) of FIG.

  Further, when the front wheel 8 and the rear wheel 13 are disposed in the same plane, the spring member 16 is in an unloaded state (state where the torsion angle is 0 degree) and the head pipe 2 is connected to the main frame. When the front wheel 8 and the rear wheel 13 are not in the same plane by being rotated with respect to 3, they are arranged in a loaded state. Specifically, as shown in FIG. 6, when the head pipe 2 is rotated to the left about the center line L1, the support portion 2b of the head pipe 2 is also rotated to the left about the center line L1. Therefore, the support portion 2b of the head pipe 2 is moved to the left side of the center line L1 when seen in a plan view. At this time, one end side of the spring member 16 is moved to the left side of the center line L1, and the other end portion 16e of the spring member 16 is disposed on the center line L1, so that the center portion of the spring member 16 is located. 16f bends to the left and enters a loaded state.

  Further, as shown in FIG. 2, a damper support portion 2 c is integrally provided below the head pipe 2. A cylinder type (hydraulic cylinder type) damper 18 for attenuating the vibration of the spring member 16 when the head pipe 2 rotates with respect to the main frame 3 is attached to the damper support portion 2c. The damper 18 is an example of the “attenuating means” in the present invention. As shown in FIGS. 7 and 8, the damper 18 includes a cylinder portion 18a, a piston 18b disposed inside the cylinder portion 18a, a piston shaft 18c fixed to the left end portion of the piston 18b, It includes a piston shaft support portion 18d (see FIG. 7) that supports the end portion of the piston shaft 18c, and an adjustment shaft portion 18e that is disposed on the right side of the piston 18b. As shown in FIG. 2, the cylinder portion 18 a is fixed to the damper support portion 2 c by bolts 42. Further, as shown in FIG. 8, oil 43 is filled in the cylinder portion 18a. The piston 18b is provided with an orifice 18f through which the oil 43 can pass. A screw hole 18g is formed in a predetermined region of the piston 18b. Further, the piston shaft support portion 18d is fixed to the front portion of the lower frame portion 3b of the main frame 3, as shown in FIG. Further, the piston shaft support portion 18d is ball-joint with a bolt 44 at the end of the piston shaft 18c. Accordingly, when the cylinder portion 18a rotates in an arc shape around the center line L1 (see FIG. 2) of the angular bearing 12, the piston shaft 18c inserted into the cylinder portion 18a is moved in the left-right direction with respect to the cylinder portion 18a. Can be moved to. As a result, since the arcuate rotational motion is converted into a linear motion, the piston shaft 18c and the piston 18b can smoothly move inside the cylinder portion 18a.

  In the present embodiment, the adjustment shaft portion 18e has a function of adjusting the cross-sectional area through which the oil 43 of the orifice 18f passes. As shown in FIG. 8, a convex portion 18h to be inserted into the orifice 18f is formed at the left end portion of the adjusting shaft portion 18e. The convex portion 18h is formed so that the cross-sectional area decreases toward the tip side. The adjusting shaft portion 18e is formed with a screw portion 18i in a region corresponding to the screw hole 18g. Thereby, it is possible to move the adjusting shaft part 18e in the left-right direction with respect to the piston 18b by rotating the adjusting shaft part 18e. As a result, it is possible to change the cross-sectional area of the gap between the convex portion 18h of the adjusting shaft portion 18e and the orifice 18f of the piston 18b, so that the cross-sectional area of the portion of the orifice 18f through which the oil 43 passes can be adjusted. It becomes possible. For example, in the state of FIG. 8, the cross-sectional area of the portion of the orifice 18f through which the oil 43 passes is reduced, and in the state of FIG. 9, the cross-sectional area of the portion of the orifice 18f through which the oil 43 passes is increased.

  In the present embodiment, as shown in FIG. 7, a damping force adjusting actuator 19 made of a servo motor is attached to the right portion of the adjusting shaft portion 18e. The damping force adjusting actuator 19 is an example of the “damping force changing means” in the present invention. As shown in FIG. 3, the damping force adjusting actuator 19 has a function of rotating the adjusting shaft portion 18 e by a predetermined amount based on an adjusting shaft portion rotation control signal input from the control portion 10. In addition, the damping force adjusting actuator 19 has a function of outputting an adjusting shaft portion rotational position signal indicating the rotational position of the adjusting shaft portion 18 e to the control unit 10. The damping force adjusting actuator 19 is provided with a spline shaft portion 19a that is spline processed. The spline shaft portion 19a is inserted in a spline hole of the connecting portion 20 having a groove corresponding to the spline of the spline shaft portion 19a so as to be movable in the left-right direction. As a result, the damping force adjusting actuator 19 can move in the left-right direction with respect to the connecting portion 20. Therefore, when the piston 18b moves in the left-right direction with respect to the cylinder portion 18a, the damping force adjusting actuator 19 is moved. It becomes possible to move the actuator 19 and the adjusting shaft portion 18e in the left-right direction integrally with the piston 18b with respect to the cylinder portion 18a. Further, the connecting portion 20 is fitted in a groove 21 a formed in the adjusting shaft portion supporting portion 21 and extending in the vertical direction. The adjusting shaft portion support portion 21 is fixed to the front portion of the lower frame portion 3 b of the main frame 3.

  In the above-described damper 18, when the head pipe 2 rotates about the center line L <b> 1 (see FIG. 2) of the angular bearing 12 with respect to the main frame 3, the cylinder portion matches the rotation of the head pipe 2. While 18a moves to the left-right direction, piston 18b moves inside the cylinder part 18a. At this time, the vibration of the spring member 16 at the time of impact absorption can be attenuated by the viscous resistance when the oil 43 passes through the orifice 18f of the piston 18b. In the present embodiment, for example, when the cross-sectional area through which the oil 43 passes through the orifice 18f is reduced (see FIG. 8), the viscous resistance when the oil 43 passes through the orifice 18f increases and the damper 18 attenuates. It is possible to increase the power. When the cross-sectional area through which the oil 43 passes through the orifice 18f is increased (see FIG. 9), the viscous resistance when the oil 43 passes through the orifice 18f is reduced and the damping force of the damper 18 is reduced. Is possible.

  In the present embodiment, as shown in FIG. 7, a pair of stoppers 22 are provided in front of the main frame 3 to prevent the head pipe 2 from rotating too much with respect to the main frame 3. Yes. The stopper 22 is an example of the “regulating member” in the present invention. The pair of stoppers 22 are formed so as to come into contact when the head pipe 2 rotates at an angle of several degrees (less than 10 degrees) clockwise or counterclockwise with respect to the main frame 3 around the center line L1. ing.

  Further, as shown in FIG. 1, a headlight 23 that irradiates the front and a front cowl 24 that covers the front of the head pipe 2 are provided in front of the head pipe 2. A rearview mirror 25 is attached to the front cowl 24. Further, a light stay 26 that supports the headlight 23 is disposed between the headlight 23 and the head pipe 2. Instruments and the like are attached to the upper side of the light stay 26.

  Further, in the present embodiment, as shown in FIG. 2, the light stay 26 is fixed to the main frame 3 and rotated with respect to the head pipe 2 around the center line L1 of the shaft portion 2a of the head pipe 2. It is supported by the support part 2d of the head pipe 2 as possible. Thereby, even when the head pipe 2 rotates with respect to the main frame 3, the headlight 23 does not rotate with respect to the main frame 3, so that the front of the vehicle body (main frame 3) can be irradiated. It becomes. Further, as shown in FIG. 1, the lower portion of the front cowl 24 extends rearward downward and is fixed to a vehicle body cover (not shown) fixed to the main frame 3. A handle 27 is rotatably attached to the upper portion of the head pipe 2.

  An engine 28 is attached below the upper frame portion 3 a of the main frame 3. An exhaust pipe 29 is attached to the engine 28. The exhaust pipe 29 is curved rightward in the traveling direction and is directed downward to the rear, and is connected to the muffler 30. A radiator 31 for cooling the engine 28 is provided in an upward direction in front of the engine 28.

  The pivot shaft support member 4 attached to the rear portion of the main frame 3 is provided with a pivot shaft 4a. The pivot shaft 4a supports the front end portion of the rear arm 32 so that it can swing up and down. A rear wheel 13 is rotatably attached to the rear end portion of the rear arm 32. That is, the rear wheel 13 is attached to the main frame 3 via the rear arm 32 and the pivot shaft support member 4. The rear wheel 13 is formed of a so-called round tire having a lower surface having an arcuate portion when viewed from the traveling direction so that the rear wheel 13 can be inclined with respect to the vertical direction when turning. As described above, the engine 28 is attached to the main frame 3 that supports the rear wheel 13, and the rear wheel 13 is formed of a round tire so as to be inclined with respect to the vertical direction together with the main frame 3 and the engine 28 when turning. As a result, the rear wheel 13 is tilted together with the heavy engine 28. Therefore, by tilting the rear wheel 13, the center of gravity G of the vehicle body can be easily moved in the lateral direction (width direction of the vehicle body) in the traveling direction. Is possible. As a result, it is possible to facilitate turning, and thus it is possible to improve the turning performance of the motorcycle 1. The front wheel 8 is also formed of a round tire, like the rear wheel 13. A fuel tank 33 is disposed on the upper frame portion 3 a of the main frame 3. A seat 34 is disposed behind the fuel tank 33.

  In the present embodiment, the control unit 10 is disposed below the seat 34. As shown in FIG. 3, the control unit 10 includes a rotation speed signal from the rotation speed sensor 9, a spring member rotation position signal from the spring constant adjustment actuator 17, and an adjustment from the damping force adjustment actuator 19. The shaft rotational position signal is input. Moreover, the control part 10 has a function which calculates a vehicle speed based on the input rotational speed signal. Further, the controller 10 rotates the spring member that rotates the spring constant adjusting actuator 17 by a predetermined amount based on the calculated vehicle speed and the spring member rotating position signal from the spring constant adjusting actuator 17. A control signal is transmitted. Further, the control unit 10 controls the adjustment shaft part rotation to rotate the damping force adjustment actuator 19 by a predetermined amount based on the calculated vehicle speed and the adjustment shaft part rotation position signal from the damping force adjustment actuator 19. It is configured to transmit a signal. Thereby, it becomes possible to adjust the spring constant with respect to the bending direction (left-right direction) of the spring member 16 and the damping force of the damper 18 based on the vehicle speed.

  Specifically, as shown in FIG. 10, the controller 10 has a rotational position in which the rotational position of the spring member 16 continuously increases with respect to the vehicle speed in the range of about 0 degrees to about 90 degrees. In this manner, the spring constant adjusting actuator 17 is controlled. That is, when the vehicle speed is about 0 km / h, the spring constant adjusting actuator 17 is controlled so that the rotational position of the spring member 16 is about 0 degrees (the state shown in FIG. 5 (1)). At the same time, when the vehicle speed is the maximum speed, the spring constant adjusting actuator 17 is controlled so that the rotational position of the spring member 16 is about 90 degrees (the state shown in FIG. 5 (3)). . Similarly, as shown in FIG. 11, the control unit 10 rotates so that the rotation position of the adjustment shaft portion 18 e continuously increases with respect to the vehicle speed in the range of about 0 degrees to about 1080 degrees (about 3 rotations). The damping force adjusting actuator 19 is controlled so as to be in the position (rotational position). As a result, when the vehicle speed is about 0 km / h, as shown in FIG. 8, the adjustment shaft portion 18e moves to the right with respect to the piston 18b and the cross-sectional area through which the oil 43 of the orifice 18f of the piston 18b passes. Can be increased. Further, as the vehicle speed increases, as shown in FIG. 9, the adjusting shaft portion 18e moves to the left with respect to the piston 18b, and gradually decreases the cross-sectional area passing through the oil 43 of the orifice 18f of the piston 18b. It is possible.

  FIGS. 12 to 16 are diagrams for explaining the operation when the head pipe rotates with respect to the main frame when the motorcycle according to the embodiment shown in FIG. 1 turns. FIG. 17 is a diagram for explaining the operation corresponding to FIG. 15 of the conventional motorcycle as a comparative example of the embodiment shown in FIG. Next, with reference to FIG. 2 and FIGS. 12 to 17, operations during turning of the motorcycle 1 according to the embodiment of the present invention and the motorcycle according to the comparative example will be described.

  First, when the motorcycle 1 according to the present embodiment turns, the vehicle body is inclined from the state shown in FIG. 12 to the side to turn with respect to the vertical direction as shown in FIG. And as shown in FIG. 14, when the convex part 100a exists in the ground 100, in this embodiment, front wheel 8 is moved so that the front wheel 8 may move in the direction (arrow A direction) along the convex part 100a of the ground 100. The head pipe 2 to which 8 is attached rotates with respect to the main frame 3 (see FIG. 2). In this case, when the spring member 16 (see FIG. 2) is bent, the impact in the direction along the convex portion 100a (the direction of the arrow A) is sufficiently absorbed.

  Further, when the motorcycle 1 according to the present embodiment turns leftward, for example, the vehicle body is tilted to the left with respect to the vertical direction from the state shown in FIG. The wheel 13 is in the state shown in (2) of FIG. 15 and FIG. When turning left, as shown in FIG. 15 (3), the front wheel 8 is given a steering angle θ1 leftward. Further, in the state shown in FIG. 16, the front wheel 8 and the rear wheel 13 are opened in the left-right direction, and the load direction of the center of gravity G (in the direction of arrow B) is the contact point A1 of the front wheel 8 and the rear wheel 13. It passes between the ground point A2 and does not pass through the center line L1. As a result, the load of the center of gravity G is F [N], the intersection point with the ground 100 on the extension line in the load direction (arrow B direction) of the center of gravity G is B1, and the center from the line Lg connecting the centers of gravity G and B1. If the distance from the extension of the line L1 is r [m], a moment of M = F × r [N · m] is generated around the center line L1. Due to this moment, the main frame 3 (see FIG. 2) rotates about the center line L1 so that the front wheels fall down so as to get up. In this case, the rear wheel 13 rotates to the right with a center line L1 extending obliquely downward in the rearward direction. Therefore, as shown in (3) of FIG. A slight steering angle θ2 is given. As a result, the angle at which the central axis C1 of rotation of the front wheel 8 and the central axis C2 of rotation of the rear wheel 13 intersect can be reduced, so that the turning radius can be increased. As a result, stability can be improved. That is, the steering angle θ2 and the camber thrust are added to the rear wheel 13 to increase the turning radius.

  The operation of a conventional motorcycle as a comparative example in which the head pipe is non-rotatably connected to the main frame is, for example, the state shown in FIG. 17 (1) when turning leftward. The vehicle body is tilted to the left with respect to the vertical direction. As a result, the state shown in FIG. When turning leftward, as shown in FIG. 17 (3), the front wheel 8 is given a steering angle θ3 leftward. Further, in the structure of a conventional motorcycle as a comparative example, the head pipe is non-rotatably connected to the main frame, so that the rear wheel 13 includes a ground point A1 of the front wheel 8 and a ground point of the rear wheel 13. It rotates around the line connecting A2. Thereby, the front side of the rear wheel 13 and the rear side of the rear wheel 13 are at the same position (position where the steering angle is 0 degree) with respect to the width direction of the motorcycle as shown in FIG. Therefore, the center axis C12 of the rotation of the rear wheel 13 is a direction orthogonal to the traveling direction. For this reason, the angle at which the center axis C11 of rotation of the front wheel 8 and the center axis C12 of rotation of the rear wheel 13 intersect is larger than that of the above-described embodiment of the present invention. Thereby, in the conventional motorcycle as a comparative example, the turning radius becomes smaller than that of the above-described embodiment of the present invention and tends to be unstable.

  FIG. 18 is a diagram for explaining the operation when the head pipe rotates with respect to the main frame during the straight traveling of the motorcycle according to the embodiment shown in FIG. 1, and FIG. FIG. 19 is a diagram for explaining an operation corresponding to FIG. 18 of a conventional motorcycle as a comparative example of the illustrated embodiment. Next, with reference to FIG. 1, FIG. 2, FIG. 18 and FIG. 19, the operation of the motorcycle 1 according to one embodiment of the present invention and the motorcycle according to the comparative example during straight running will be described.

  Usually, a motorcycle may flutter at a low speed, for example. This embodiment has an effect of reducing the fluctuation. First, in the motorcycle 1 according to the present embodiment, when the motorcycle 1 shown in (1) of FIG. 18 travels straight, the front wheel 8 of the motorcycle 1 advances for some reason as shown in (2) of FIG. Turn left diagonally forward with respect to the direction. At this time, the center of gravity G of the motorcycle 1 tries to advance in the straight direction by the inertial force, and the head pipe 2 to which the front wheel 8 is attached rotates with respect to the main frame 3 (see FIG. 2). No. only goes further to the left as shown in FIG. 18 (3).

  Next, in order to balance the vehicle, the front wheel 8 is steered in the opposite right direction, and after being in the state shown in FIG. 18 (4), steered to the right as shown in FIG. 18 (5). Since the head pipe 2 to which the front wheel 8 is attached rotates relative to the main frame 3 (see FIG. 2), only the front wheel 8 moves further to the right as shown in FIG. The states (1) to (6) in FIG. 18 are repeated.

  At this time, as shown in FIG. 18 (7), the movement of the motorcycle 1 is such that only the front wheel 8 moves in the left-right direction, and the main frame 3 moves substantially straight, so that the driver who is riding on the main frame 3 Feels like he is driving without wandering.

  The operation of the conventional motorcycle as a comparative example in which the head pipe is non-rotatably connected to the main frame is as shown in (2) of FIG. 19 when the motorcycle shown in FIG. As shown in (), for some reason, the front wheel 8 of the motorcycle is directed obliquely left frontward with respect to the traveling direction. At this time, the front wheel 8 tries to move to the left. As a result, as shown in FIG. 19 (3), the entire motorcycle must be turned to the left.

  Next, in order to balance the vehicle, the front wheel 8 is steered in the opposite right direction, and after being in a state as shown in FIG. 19 (4), steered to the right as shown in FIG. 19 (5). The front wheel 8 tries to move in the right direction. As a result, as shown in FIG. 19 (6), the entire motorcycle must be turned to the right, and the states (1) to (6) in FIG. 19 are repeated.

  At this time, as shown in (7) of FIG. 19, the movement of the motorcycle is such that the front wheel 8 moves in the left-right direction and the main frame 3 also moves in the left-right direction so as to follow it. The driving driver feels like he is running around.

  In the present embodiment, as described above, the main frame 3 to which the head pipe 2 is rotatably attached around the center line L1 of the shaft portion 2a extending in the front-rear direction is provided, and the head pipe 2 is rotated relative to the main frame 3. By providing the spring member 16 that absorbs an impact at the time of movement at a position other than the center line L1 extending in the front-rear direction, the front wheel 8 moves along the unevenness of the ground 100 when turning with the vehicle body tilted. The head pipe 2 can be rotated with respect to the main frame 3 so as to move in the width direction, and the bending force of the spring member 16 provided at a position other than the center line L1 extending in the front-rear direction during the rotation. Thus, the impact in the width direction (lateral direction) of the vehicle body can be actively absorbed. Thereby, the impact in the width direction (lateral direction) of the vehicle body due to the unevenness of the ground 100 can be sufficiently absorbed.

  Further, in the present embodiment, by providing the controller 10 that controls the spring constant adjusting actuator 17 so that the spring constant with respect to the bending direction of the spring member 16 increases as the calculated vehicle speed increases, When the vehicle speed is low, the spring constant with respect to the bending direction of the spring member 16 can be reduced, so that the main frame 3 is rotated more with respect to the head pipe 2 when the vehicle body is tilted. Can be made. Thereby, since a large steering angle can be given to the rear wheel 13 supported by the main frame 3, the turning radius can be increased. Thereby, stability can be improved. Further, when the vehicle speed is high, the spring constant with respect to the bending direction of the spring member 16 can be increased, so that the rotational frequency of the wheels (front wheel 8 and rear wheel 13) becomes higher as the vehicle speed increases. Even in this case, the resonance of the spring member 16 can be suppressed. Further, when the vehicle speed is high, the spring constant with respect to the bending direction of the spring member 16 can be increased, so that the amount of rotation of the main frame 3 relative to the head pipe 2 is reduced when the vehicle body is tilted. Therefore, a small steering angle can be given to the rear wheel 13 supported by the main frame 3. That is, as the vehicle speed increases, the amount of steering angle required for turning decreases, so that a steering angle suitable for the vehicle speed can be provided.

  In the present embodiment, the spring constant adjusting actuator 17 is fixed to the press-fitting hole 16d of the other end 16e of the spring member 16, so that the spring constant of the spring member 16 is directly adjusted by the spring constant adjusting actuator 17. Since it can be changed, the spring constant of the spring member 16 can be controlled with high accuracy.

  Further, in the present embodiment, by rotating the spring member 16 about the center line L2, the cross-sectional secondary moment about the axis orthogonal to the bending direction (left-right direction) of the center portion 16f having a flat plate shape is changed. Therefore, the spring constant can be changed with respect to the bending direction (left-right direction).

  In this embodiment, the pillow ball 16 a of the spring member 16 is attached to the support portion 2 b of the head pipe 2, and the other end portion 16 e of the spring member 16 is attached to the upper frame portion 3 a of the main frame 3. When the pipe 2 is rotated with respect to the main frame 3, the impact can be easily absorbed by the bending force of the spring member 16.

  In the present embodiment, by providing the damper 18, the vibration of the spring member 16 is attenuated by the damper 18 when the head pipe 2 rotates with respect to the main frame 3 and absorbs the impact by the spring member 16. be able to. Thereby, the convergence property at the time of impact absorption by the spring member 16 can be improved.

  Further, in the present embodiment, by providing the control unit 10 that controls the damping force adjusting actuator 19 so that the damping force of the damper 18 increases as the vehicle speed increases, when the vehicle speed is low, Since the force (attenuating force) resisting the rotation when the head pipe 2 is rotated with respect to the main frame 3 can be reduced, the head pipe 2 is quickly rotated with respect to the main frame 3 when absorbing the impact. be able to. Thereby, an impact can be absorbed more fully. Further, when the vehicle speed is high, the damping force of the damper 18 can be increased, so that the impact in the width direction (lateral direction) of the vehicle body applied due to the unevenness of the ground 100 increases as the vehicle speed increases. Even in this case, the vibration of the spring member 16 can be sufficiently damped by the damper 18. Thereby, the convergence at the time of impact absorption by the spring member 16 can be sufficiently improved.

  In the present embodiment, the main frame 3 is rotated with respect to the head pipe 2 by passing an extension line of the center line L1 of the shaft portion 2a extending in the front-rear direction through the vicinity of the contact point between the rear wheel 13 and the ground 100. When moving, the rear wheel 13 rotates around the vicinity of the contact point with the ground 100, so that the rear wheel 13 can be prevented from sliding in the left-right direction with respect to the ground 100.

  In this embodiment, the head pipe 2 is rotated too much with respect to the main frame 3 by providing a pair of stoppers 22 for restricting the angle at which the head pipe 2 is rotated with respect to the main frame 3. Can be prevented.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiment but by the scope of claims for patent, and all modifications within the meaning and scope equivalent to the scope of claims for patent are included.

  For example, in the above-described embodiment, a motorcycle is shown as an example of the vehicle. However, the present invention is not limited to this, and a bicycle, a tricycle, an ATV (All Terrain Vehicle; It can also be applied to other vehicles such as leveling vehicles.

  In the above embodiment, the example in which the actuator for adjusting the spring constant and the actuator for adjusting the damping force are configured by the servo motor has been described. However, the present invention is not limited to this, and the actuator for adjusting the spring constant and the damping force adjustment are shown. The actuator may be constituted by a hydraulic cylinder, or may be constituted by another operating device.

  In the above embodiment, an example in which the vehicle speed is calculated based on the rotational speed of the front wheel has been described. However, the present invention is not limited thereto, and the vehicle speed is calculated based on the rotational speed of the rear wheel or the rotational speed of the transmission. May be.

  In the above embodiment, the center line L1 of the shaft portion of the head pipe extends downward in the rear direction and passes through the vicinity of the contact point between the rear wheel and the ground. Not limited to this, the center line L1 of the shaft portion of the head pipe may extend downward in the rear direction, and may be configured not to pass near the contact point between the rear wheel and the ground.

  Moreover, in the said embodiment, although the example which has arrange | positioned the other end part 16e of the spring member 16 so that the center axis | shaft may become substantially parallel to the centerline L1, this invention is not restricted to this, Like the motorcycle 51 according to the first modification of the present embodiment shown in FIGS. 20 to 22, the other end portion 66 e of the spring member 66 is centered on the center line L 51 of the shaft portion 52 a of the head pipe 52. You may arrange | position so that it may cross | intersect (orthogonal). In the motorcycle 51 according to the first modification, as shown in FIG. 21, the pillow ball 66a of the spring member 66 is attached to the support portion 52b of the head pipe 52, and the other end 66e of the spring member 66 is connected to the main frame. It is attached to the upper part of 53 shaft insertion part 53c. A damper 68 having the same internal structure as the damper 18 shown in FIG. 8 is disposed behind the spring member 66. Specifically, as shown in FIG. 22, the attachment portion 68 b of the cylinder portion 68 a of the damper 68 is attached to the damper support portion 52 c of the head pipe 52, and the piston shaft 68 c of the damper 68 is formed on the main frame 53. The piston shaft support 53a is attached so as to be rotatable in the Q direction. In the motorcycle 51 according to the first modification, the spring member 66 is disposed along a portion extending perpendicular to the center line L51 of the head pipe 52, thereby omitting the portion where the spring member 66 is disposed. It is possible to make space. As in the first modification, the spring constant adjusting actuator 67 may be arranged on the pillow ball 66a side of the spring member 66.

  In the above embodiment, the control unit continuously increases the rotation position of the spring member and the rotation position of the adjustment shaft portion as the vehicle speed calculated based on the rotation speed signal from the rotation speed sensor increases. As described above, the example of controlling the actuator for adjusting the spring constant and the actuator for adjusting the damping force has been shown. However, the present invention is not limited to this, and the control unit can calculate the vehicle speed calculated based on the rotational speed signal from the rotational speed sensor. The spring constant adjusting actuator and the damping force adjusting actuator may be controlled so that the rotational position of the spring member and the rotational position of the adjusting shaft portion increase stepwise with the increase. Specifically, as in the second modification of the present embodiment shown in FIGS. 23 and 24, when the vehicle speed is divided into a plurality of ranges and the vehicle speed is within a predetermined range, the spring member is set to the predetermined range. The actuator for adjusting the spring constant is controlled so that the rotation position corresponds to the vehicle speed in the range, and the actuator for adjusting the damping force is controlled so that the adjustment shaft portion becomes the rotation position corresponding to the vehicle speed in the predetermined range. You may make it do.

  Moreover, in the said embodiment, although the example which attached the one end part and the other end part of the spring member to the head pipe and the main frame without using a rolling bearing was shown, this invention is not limited to this, and one side of a spring member is shown. The end and the other end may be attached to the head pipe and the main frame using a rolling bearing such as an angular bearing or a tapered roller bearing.

  Moreover, in the said embodiment, while forming the center part which generate | occur | produces the stress by the bending of a spring member so that it may have a flat plate shape, the spring with respect to the bending direction of a spring member is rotated by rotating a spring member centering on the centerline L2. Although an example in which the constant can be changed has been described, the present invention is not limited to this, and the center portion where the stress due to the bending of the spring member is generated is formed to have a shape other than a flat plate shape, and the spring member is centerline You may make it possible to change the spring constant with respect to the bending direction of a spring member by rotating around L2.

  Further, in the above embodiment, a cylinder type damper that linearly moves is used as an example of the damping means for damping the vibration of the spring member when the head pipe rotates with respect to the main frame. Not limited to this, as a damping means for damping the vibration of the spring member when the head pipe rotates with respect to the main frame, a rotary damper that moves circularly on the same axis as the center line L1 may be used. Further, it is not necessary to provide a member for attenuating the vibration of the spring member when the head pipe rotates with respect to the main frame.

  In the above embodiment, an example in which a spring member is provided as an example of an impact absorbing member that absorbs an impact when the head pipe rotates relative to the main frame has been described. A member other than the spring member may be provided as an impact absorbing member that absorbs an impact during rotation with respect to the main frame.

  In the above embodiment, an example in which an angular bearing is used to rotatably support the head pipe and the main frame has been shown. However, the present invention is not limited thereto, and the head pipe and the main frame are connected to each other. Other bearings, such as tapered roller bearings, may be used for pivotal support.

1 is a side view showing an overall structure of a motorcycle according to an embodiment of the present invention. FIG. 2 is a side view of the vicinity of a head pipe of the motorcycle according to the embodiment shown in FIG. 1. FIG. 2 is a diagram for explaining control of a spring member and a damper by a control unit of the motorcycle according to the embodiment shown in FIG. 1. FIG. 2 is a perspective view for explaining the structure of a spring member of the motorcycle according to the embodiment shown in FIG. 1. FIG. 2 is a view for explaining the structure of a spring member of the motorcycle according to the embodiment shown in FIG. 1. FIG. 2 is a view for explaining the structure of a spring member of the motorcycle according to the embodiment shown in FIG. 1. It is the figure seen from the arrow P direction of FIG. FIG. 2 is a cross-sectional view of the motorcycle damper according to the embodiment shown in FIG. 1. FIG. 2 is a cross-sectional view of the motorcycle damper according to the embodiment shown in FIG. 1. FIG. 2 is a diagram for explaining a relationship between a vehicle speed of the motorcycle according to the embodiment shown in FIG. 1 and a rotational position of a spring member. FIG. 2 is a diagram for explaining a relationship between a vehicle speed of the motorcycle according to the embodiment shown in FIG. 1 and a rotation position of an adjustment shaft portion. FIG. 2 is a diagram for explaining an operation when a head pipe rotates with respect to a main frame when the motorcycle according to the embodiment shown in FIG. 1 turns. FIG. 2 is a diagram for explaining an operation when a head pipe rotates with respect to a main frame when the motorcycle according to the embodiment shown in FIG. 1 turns. FIG. 2 is a diagram for explaining an operation when a head pipe rotates with respect to a main frame when the motorcycle according to the embodiment shown in FIG. 1 turns. FIG. 2 is a diagram for explaining an operation when a head pipe rotates with respect to a main frame when the motorcycle according to the embodiment shown in FIG. 1 turns. FIG. 16 is a front view of a rear wheel of the motorcycle according to the embodiment shown in FIG. FIG. 16 is a diagram for explaining an operation corresponding to FIG. 15 of a conventional motorcycle as a comparative example of the embodiment shown in FIG. 1. FIG. 2 is a diagram for explaining an operation when a head pipe rotates with respect to a main frame when the motorcycle according to the embodiment shown in FIG. 1 travels straight. FIG. 19 is a diagram for explaining an operation corresponding to FIG. 18 of a conventional motorcycle as a comparative example of the embodiment shown in FIG. 1. FIG. 6 is a side view showing an overall structure of a motorcycle according to a first modification of one embodiment of the present invention. FIG. 6 is a side view of the vicinity of a head pipe of a motorcycle according to a first modification of one embodiment of the present invention. FIG. 6 is a view for explaining a damper mounting structure for a motorcycle according to a first modification of the embodiment of the present invention. FIG. 6 is a diagram for explaining a relationship between a vehicle speed of a motorcycle and a rotation position of a spring member according to a second modification of the embodiment of the present invention. FIG. 6 is a diagram for explaining a relationship between a vehicle speed of a motorcycle and a rotation position of an adjustment shaft portion according to a second modification of the embodiment of the present invention.

Explanation of symbols

1 Motorcycle (vehicle)
2 Head pipe (front frame)
3 Main frame (rear frame)
8 Front wheel 9 Rotational speed sensor (vehicle speed detection means)
10 control unit (first control means, second control means)
12 Angular bearing (bearing)
13 Rear wheel 16 Spring member (Shock absorbing member)
16e The other end part 16f Center part (flat plate shape part)
17 Spring constant adjusting actuator (spring constant changing means, actuator)
18 Damper (Attenuation means)
19 Damping force adjusting actuator (Damping force changing means)
22 Stopper (Regulator)
100 Ground L1 Center line (axis)

Claims (20)

A front frame that supports the front wheels;
A rear frame that supports a rear wheel and is rotatably attached to an axis extending in the front-rear direction.
An impact absorbing member disposed at a position other than on the axis extending in the front-rear direction while absorbing an impact when the front frame is rotated with respect to the rear frame;
A vehicle comprising: a spring constant changing means for changing a spring constant with respect to a bending direction of the shock absorbing member according to a traveling state. Vehicle speed detection means for detecting the vehicle speed;
First control means for controlling the spring constant with respect to the bending direction of the shock absorbing member by controlling the spring constant changing means based on the vehicle speed corresponding to the detection output of the vehicle speed detecting means; The vehicle according to claim 1.   The first control means is configured to change the spring constant so that the spring constant with respect to the bending direction of the shock absorbing member increases as the vehicle speed corresponding to the detection output of the vehicle speed detection means increases. The vehicle according to claim 2, wherein the vehicle is controlled.   The first control means continuously or stepwise increases the spring constant with respect to the bending direction of the shock absorbing member as the vehicle speed corresponding to the detection output of the vehicle speed detecting means increases. The vehicle according to claim 3, wherein the spring constant changing means is controlled.   The vehicle according to claim 1, wherein the spring constant changing means includes an actuator. The impact absorbing member includes a spring member,
The vehicle according to claim 5, wherein the actuator is attached to at least one of one end and the other end of the spring member.   2. The vehicle according to claim 1, wherein the shock absorbing member includes a spring member disposed between the front frame and the rear frame and at a position other than an axis extending in the front-rear direction.   The vehicle according to claim 7, wherein a center line of the spring member is arranged substantially parallel along the axis.   The vehicle according to claim 7, wherein a center line of the spring member is arranged to intersect the axis.   The vehicle according to claim 7, wherein the spring member has a flat plate-shaped portion that is a portion where stress due to bending occurs.   The vehicle according to claim 10, wherein the spring constant is changed by changing an angle of the flat plate-shaped portion with respect to the bending direction by the spring constant changing means. One end of the spring member is attached to the front frame,
The vehicle according to claim 7, wherein the other end portion of the spring member is attached to the rear frame. Attenuating means for attenuating rotation of the front frame relative to the rear frame;
The vehicle according to claim 1, further comprising damping force changing means for changing the damping force of the damping means according to a traveling state. Vehicle speed detection means for detecting the vehicle speed;
The control apparatus according to claim 13, further comprising second control means for controlling the damping force of the damping means by controlling the damping force changing means based on the vehicle speed corresponding to the detection output of the vehicle speed detecting means. The vehicle described.   The second control means controls the damping force changing means so that the damping force of the damping means increases as the vehicle speed corresponding to the detection output of the vehicle speed detecting means increases. Item 15. The vehicle according to Item 14.   The vehicle according to claim 1, wherein an extension line of an axis extending in the front-rear direction passes near a contact point between the rear wheel and the ground.   The vehicle according to claim 1, further comprising a bearing that is disposed between the front frame and the rear frame and rotatably supports the front frame and the rear frame.   The vehicle according to claim 1, wherein a center of gravity is located at a portion other than an extension line of an axis extending in the front-rear direction.   The vehicle according to claim 1, wherein an axis extending in the front-rear direction extends in a downward direction behind the front frame.   The vehicle according to claim 1, further comprising a regulating member for regulating an angle at which the front frame rotates with respect to the rear frame.

Images