JP2008247307A - Front structure of motorcycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a front structure of a motorcycle having a hub steering mechanism and a simpler structure capable of reducing the number of parts. <P>SOLUTION: This front structure of a motorcycle 10 comprises lower arms 15L, 15R and upper arms 13L, 13R swingably extending forward from a vehicle body frame 11, a hub steering mechanism 20 and knuckle arms 21L, 21R provided at tips of the lower arms 15L, 15R and steerably supporting a front wheel 16, a steering handle 23 provided to the knuckle arms 21L, 21R via a handle link 22, a front cushion mechanism 25 connected to the upper arms 13L, 13R, and a top steering shaft 88 provided at tips of the upper arms 13L, 13R. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an improvement in a front structure of a motorcycle including a hub steer mechanism that supports a front wheel in a steerable manner.

There is known a motorcycle including an arm that swings forward from a vehicle body frame, and a hub steer mechanism and a knuckle arm that are provided at the tip of the arm and support a front wheel so as to be steerable (for example, Patent Document 1). reference.).
Japanese translation of PCT publication No. 2002-500133 (FIG. 4)

In FIG. 4 of Patent Document 1, a motorcycle 50 (hereinafter referred to as “motorcycle 50”) includes support arms 55 and 56 (reference numerals are those of the same publication) that extend swingably forward from the body frame. The same applies hereinafter.), A connecting part 57 provided at the tip of these support arms 55, 56, and a wheel 52 (hereinafter referred to as "front wheel 52") provided in the middle part of the connecting part 57 can be steered. A hub steer mechanism that supports the hub steer mechanism, a steering bracket 65 that supports the hub steer mechanism so as to be steerable (hereinafter referred to as “knuckle arm 65”), and a lower connecting part 71 (hereinafter referred to as “handle link 71”). And a handlebar 70 which is provided via a steering wheel and is steered by an occupant.
In addition, the upper part of the knuckle arm 65 is supported by a centering bracket 102 extending forward from the frame 51.

That is, the front wheel 52 is supported by five members, that is, the support arms 55 and 56, the connection component 57, the knuckle arm 65, and the centering bracket 102 in a side view.
The centering bracket 102 is connected to a link mechanism including the auxiliary lot 103 and the pivot shafts 104 and 105, and is attached to the frame 51 via the link mechanism so as to be extendable and contractable.
As described above, in a motorcycle including a hub steer mechanism that supports the front wheels in a steerable manner, the front wheels are supported in a swingable and steerable manner, so that the number of parts is increased and the structure is complicated.

  An object of the present invention is to provide a front structure of a motorcycle that can reduce the number of parts and has a simpler structure in a motorcycle including a hub steer mechanism.

  In the first aspect of the invention, the lower arm and the upper arm that extend swingably forward from the vehicle body frame or the engine, the hub steer mechanism that is provided at the tip of the lower arm and supports the front wheels so as to be steerable, and the lower portion is connected to the hub steer mechanism. A front knuckle arm, a steering handle provided on the upper portion of the knuckle arm via a handle link, and a front cushion mechanism that is coupled to the lower arm or the upper arm and absorbs the force received by the front wheel. The tip of the upper arm and the upper part of the knuckle arm are connected via an upper steering shaft and a first spherical bearing surrounding the upper steering shaft, and the upper part of the knuckle arm can be steered by operating the steering handle and It is supported so that it can swing.

  In the invention according to claim 2, the hub steering mechanism includes a lateral member extending in the left-right width direction on the lower arm, a lower steering shaft extending substantially perpendicular to the lateral member, and rotating and rotating the front wheels on the lower steering shaft. A hub body that is steerably supported, and a second spherical bearing that is provided in the hub body and supports the hub body so as to be steerable and swingable are disposed. The second spherical bearing is attached to the lateral member and / or the lower steering shaft. It is connected.

  The invention according to claim 3 is characterized in that the axle bearing that rotatably supports the front wheel is supported by a knuckle arm.

  The invention according to claim 4 is characterized in that the inner diameter of the axle bearing is larger than the size of the lateral member when the vehicle is viewed from the side.

  In the invention according to claim 5, the knuckle arm is a first fastening member extending in the vehicle width direction and is detachably provided on the hub body, and the lower arm is a second fastening member extending inward from the outside of the vehicle. And it is provided in the horizontal member so that attachment or detachment is possible.

  In the invention according to claim 1, the tip of the upper arm is provided with an upper steering shaft and a first spherical bearing that support the upper portion of the knuckle arm so as to be steerable and swingable, and the upper steering shaft and the first spherical surface are provided. With the bearing, the force in the direction around the upper steering shaft and the force in the axial direction are supported so as to be swingable.

In the conventional example, a large number of arms are provided between the front wheel and the vehicle body frame in order to ensure the support rigidity of the front wheel. In addition, on the upper part of the knuckle arm, for example, a ball joint and a link mechanism are provided to support an axial force and a force in the direction around the shaft so as to be swingable.
That is, the front wheel and the vehicle body frame are connected by a plurality of arms, and an upper arm having a link mechanism is provided on the upper part of the knuckle arm, resulting in a large number of parts.

In this regard, in the present invention, since the upper steering shaft and the first spherical bearing are provided at the upper part of the knuckle arm, the number of parts can be reduced at the upper part of the knuckle arm.
Further, since the upper steering shaft and the first spherical bearing provide sufficient support rigidity in the steering shaft direction and the direction around the steering shaft, the number of arms supporting the front wheels can be reduced to one.

If the link mechanism becomes unnecessary and the number of arms supporting the front wheels is reduced, the number of parts can be reduced, and the front support structure can be configured more simply.
As a result, it is possible to reduce component costs and assembly man-hours.

  In the invention according to claim 2, the knuckle arm is attached to the vehicle body frame side via the second spherical bearing, the line connecting the first and second spherical bearings is used as the turning shaft of the front wheel, and the upper end of the knuckle arm is the vehicle body. The knuckle arm can be swung and swiveled to the side, and the lower end of the knuckle arm can be swung and swiveled through the hub body.

  The upper end and lower end of the knuckle arm are configured to be swingable, and the force received by the front wheel is swingably received at the upper end portion and the lower end portion of the knuckle arm. Accordingly, the inclination of the steering shaft can be increased, and the flexibility of the vehicle with respect to the force received by the front wheels can be increased. In addition, since the movable portion has a simple and compact structure, the number of movable portions around the steering shaft is reduced, and the maneuverability and turning performance of the vehicle can be further enhanced.

In the invention according to claim 3, the second spherical bearing is attached to the transverse member, and the axle bearing is attached to the knuckle arm. In other words, the steering support bearing and the rotation support bearing are supported by different members.
By supporting the steering support bearing and the rotation support bearing with different members, the respective bearings can be easily attached and detached, and the maintainability can be improved.

  In the invention according to claim 4, since the inner diameter of the axle bearing is made larger than the size of the transverse member, the load received from the wheel of the front wheel can be distributed and received over a wide area. For this reason, the load of the axle bearing can be reduced. In addition, since the load is received distributed over a wide area, the cooling performance of the axle bearing is enhanced, and the durability of the axle bearing can be improved.

In the invention which concerns on Claim 5, when replacing | exchanging a tire, a 1st fastening member is removed from the outer side of a vehicle, and a knuckle arm is removed from a hub main body. Then, the second fastening member is removed from the outside of the vehicle, the lateral member is removed from the hub body, and the front wheel is removed.
For this reason, even in a vehicle body having a hub steer mechanism, the detachability and maintenance performance of the tire attached to the front wheels are improved as compared with those having a conventional hub steer mechanism.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. In the figure, “front”, “rear”, “left”, “right”, “upper”, and “lower” respectively indicate directions viewed from the occupant. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a left side view of a motorcycle according to the present invention, and FIG. 2 is a front view of the motorcycle according to the present invention. Hereinafter, description will be given with reference to FIGS. 1 and 2.

  The front portion 10F of the motorcycle 10 extends so as to be able to swing up and down via a main frame 11a as a component of the body frame 11 and the front upper swing shafts 12L and 12R forward from the upper portion of the main frame 11a. Upper arms 13L and 13R to be extended, and lower arms 15L extending forward and downward through lower front pivot shafts 14L and 14R (only the reference numeral 14L on the front side is shown) from the lower portion of the main frame 11a. 15R, a hub steer mechanism 20 that is provided at the tip of these lower arms 15L and 15R and supports the front wheel 16 so as to be steerable, knuckle arms 21L and 21R that are provided above the hub steer mechanism 20 and support the front wheel 16 so as to be steerable, and these The knuckle arms 21L and 21R are attached to the upper ends of the knuckle arms 21L and 21R so that the knuckle arms 21L and 21R can be expanded and contracted up and down The handle link 22 that is connected, the steering handle 23 that is attached to the upper end portion 22t of the handle link 22 and steered by the occupant, and the front portion that is provided between the upper arms 13L and 13R and the main frame 11a and absorbs the force received by the front wheels 16 And a cushion mechanism 25.

  In other words, the lower ends of the knuckle arms 21L and 21R are supported by the lower arms 15L and 15R, and the upper ends of the knuckle arms 21L and 21R are supported by the upper arms 13L and 13R.

  The steering handle 23 is a member that extends from the engine 26 in front of a handle support frame 27, attaches a head pipe 28 to the front end of the handle support frame 27, and is rotatably provided on the head pipe 28. . The knuckle arms 21L and 21R and the steering handle 23 are connected to each other by a handle link 22 so that the knuckle arms 21L and 21R can be expanded and contracted to absorb the vertical movement of the knuckle arms 21L and 21R.

  By providing the handle link 22, the force applied to the knuckle arms 21 </ b> L and 21 </ b> R is not directly transmitted to the steering handle 23, so that the handle support frame 27 can be reduced in weight.

  A vertical portion of the rear portion 10R of the motorcycle 10 is swingably extended from the main frame 11a through upper and lower pivot shafts 31L, 31R, 32L, and 32R (only the reference numbers 31L and 32L are shown on the front side). Arm members 33L, 33R, 34L, and 34R (only front side symbols 33L and 34L are shown), and rear support shafts 35, 36L, and 36R (from the rear ends of the upper and lower arm members 33L, 33R, 34L, and 34R) The rear swing arm 37 extends so as to be able to swing rearward through the rear swing arm 37, and is attached to the rear end portion of the rear swing arm 37 via the rear wheel axle 38. And a rear cushion mechanism 41 provided between the rear swing arm 37 and the main frame 11a for absorbing the force applied to the rear wheel 39. Upper arm members 33L, 33R (only the front side reference 33L is shown) are members extending from the upper part of the rear end of the main frame 11a, and lower arm members 34L, 34R (only the front side reference 34L are shown). .) Is a member extending from the lower part of the rear end of the main frame 11a.

An engine 26 as a drive source is suspended from the main frame 11a, and a drive shaft 42 for driving the rear wheel 39 extends from the rear end of the engine 26 to the rear.
The details of the hub steering mechanism 20 and the front cushion mechanism 25 will be described later.

The engine 26 includes an air cleaner 44 as a component of the intake system and an exhaust pipe 45 through which the exhaust gas of the engine 26 passes as a component of the exhaust system.
Further, front disk brakes 47L and 47R (only the reference numeral 47L on the front side is shown) are attached to the front wheel 16. The front disc brakes 47L and 47R are attached to the front wheel brake discs 48L and 48R attached to the front wheel 16 and the knuckle arms 21L and 21R, and the front wheel disc calipers 49L and 49R that sandwich the front wheel brake discs 48L and 48R at the time of braking. Only 49L is shown.)

  A rear disc brake 51 is attached to the rear wheel 39. The rear disk brake 51 includes a rear wheel brake disk 52 attached to the rear wheel 39 and a rear wheel disk caliper 53 attached to the rear swing arm 37 and sandwiching the rear wheel brake disk 52 during braking.

  Between the engine 26 and the front wheel 16, two upper and lower radiators 55T and 55B that are disposed above and below and cool the engine 26 are provided. The upper radiator 55T is disposed between the upper arms 13L and 13R and the lower arms 15L and 15R, and the lower radiator 55B is disposed below the lower arms 15L and 15R.

  In front of the upper and lower radiators 55T and 55B, there are provided upper and lower ducts 56T, 56T, 56B and 56B for guiding the sucked air to the radiators 55T and 55B, respectively. The upper and lower radiators 55T, 55B and the upper and lower ducts 56T, 56T, 56B, 56B are respectively attached to the lower arms 15L, 15R.

That is, since the body frame 11 and the front wheel 16 are connected by the four arms of the upper arms 13L and 13R and the lower arms 15L and 15R, a space can be secured in front of the engine 26. If space can be secured, the degree of freedom of component placement can be secured. For example, the upper and lower radiators 55T and 55B can be arranged in this space, and a sufficient cooling capacity can be obtained.
In the figure, 57 is a front cowl, 58 is a fuel tank, and 59 is a seat.

  In this embodiment, the engine 26 is a V-type engine, but may be an in-line engine in which cylinders are arranged in series. The engine is arranged in a so-called horizontal arrangement in which the crankshaft is arranged in the width direction of the vehicle. However, a so-called vertical arrangement in which the crankshaft is arranged in the longitudinal direction of the vehicle may be used. Further, the engine is not limited to the water cooling type and may be an air cooling type. In other words, the engine type and the arrangement thereof can be arbitrarily set without being limited to the embodiment.

  The front cushion mechanism 25 is provided with a front cushion unit 61 that absorbs force, and an exhaust pipe 45 through which the exhaust gas of the engine 26 passes is disposed outside the front cushion unit 61.

  Since the exhaust pipe 45 through which the exhaust gas of the engine 26 passes is arranged outside or in front of the front cushion unit 61, the expensive front cushion unit 61 can be protected by the exhaust pipe 45. Become.

FIG. 3 is a plan view of the front part of the motorcycle according to the present invention, and FIG. 4 is a perspective view of the front part of the motorcycle according to the present invention. Hereinafter, description will be made with reference to FIGS. 3 and 4.
The left and right lower arms 15L, 15R are extended forward from the main frame 11a, a horizontal member 62 is stretched between the lower arms 15L, 15R, and a lower steering shaft 63 is attached to the horizontal member 62 at a right angle. The left and right knuckle arms 21L and 21R that support the front wheels 16 from the hub steer mechanism 20 so as to be steerable are raised diagonally and rearwardly upward from the hub steer mechanism 20, and are mounted on the upper ends of the knuckle arms 21L and 21R. The left and right upper arms 13L, 13R extending forward from the main frame 11a are coupled so that the knuckle arms 21L, 21R can be steered left and right and can be swung up and down.

  The lower end portion 22b of the handle link 22 is connected to the upper end portions of the left and right knuckle arms 21L and 21R. The steering handle 23 is connected to the upper end portion 22t of the handle link 22, and steering by steering the steering handle 23 is performed. The force is transmitted to the knuckle arms 21L and 21R.

  The handle link 22 is a member that transmits the steering force of the steering handle 23 to the knuckle arms 21L, 21R while absorbing the vertical movement of the knuckle arms 21L, 21R. The lower link arm 64, the upper link arm 65, and these It consists of a connecting pin 66 that connects the upper and lower link arms 64, 65.

  The upper arms 13L and 13R (hereinafter also referred to as “arm portions 13L and 13R”) include a left arm portion 13L and a right arm portion 13R. When the vehicle is viewed from above, the left arm portion 13L and the right arm The upper portion 69t of the rod member 69 that transmits force to the front cushion unit 61 is connected to the center 68 of the substantially V shape, and the rod member 69 is connected to the front link 71. The lower end 69b of 69 is connected.

  One end 71 a of a front link 71 having a substantially L shape is connected to the lower end 69 b of the rod member 69, and one end 61 a of the front cushion unit 61 is connected to the other end 71 b of the front link 71. The other end 61 b of the front cushion unit 61 is attached to the main frame 11 a via a front cushion bracket 73.

The front link 71 is a member that changes the direction of the force received by the rod member 69, and is provided so as to be rotatable about an intermediate point 74 attached to the main frame 11a.
That is, one end 61a of the front cushion unit 61 is connected to the front link 71, and the other end 61b of the front cushion unit 61 is connected to the main frame 11a side.
The left and right lower arms 15L and 15R are formed so as to project outward from the vehicle so as to avoid interference with a brake disk or the like during steering.

5 is a cross-sectional view taken along line 5-5 in FIG. 3. The hub steering mechanism 20 includes a horizontal member 62 that extends over the ends of the left and right lower arms (reference numerals 15L and 15R in FIG. 3), and a right angle extending to the horizontal member 62. A lower steering shaft 63 is provided, and a hub body 76 that supports the front wheel 16 so that the front wheel 16 can be rotated and steered left and right. The hub body 76 includes an axle bearing 77 that rotatably supports the front wheel 16.
The center shaft 78 of the lower steering shaft 63 is disposed rearward by a length P with respect to the rotation center point 79 of the front wheel 16. 81 is a nut.

  The lower steering shaft 63 is provided with a second spherical bearing 82 that supports the hub body 76 so as to be steerable left and right and swingable up and down. The second spherical bearing 82 is disposed between the lateral member 62 and the lower steering shaft 63, and the axle bearing 77 that rotatably supports the front wheel 16 includes knuckle arms (reference numerals 21L and 21R in FIG. 3). It is arranged between the hub bodies 76.

The second spherical bearing 82 is supported by the lateral member 62, and the axle bearing 77 is supported by the knuckle arms 21L and 21R. That is, the second spherical bearing 82 as a steering support bearing and the axle bearing 77 as a rotation support bearing are supported by different members.
Since the second spherical bearing 82 and the axle bearing 77 are supported by different members, the respective bearings can be easily attached and detached, and the maintainability of the hub steering mechanism 20 can be improved.

The inner diameter Ri of the axle bearing 77 is larger than the size S of the transverse member 62 when the vehicle is viewed from the side, and S <Ri.
Since the inner diameter Ri of the axle bearing 77 is larger than the size S of the lateral member 62, the load received from the front wheel 16 can be distributed and received over a wide area. For this reason, the load of the axle bearing 77 can be reduced. Further, since the load is received distributed over a wide area, the cooling performance of the axle bearing 77 is improved, and the durability of the axle bearing 77 can be improved.

  In the present embodiment, the horizontal member 62 is supported by the left and right lower arms 15L and 15R, but may be configured to be supported by the left or right lower arm.

  6 is a cross-sectional view taken along line 6-6 in FIG. 3, and the left and right knuckle arms 21L and 21R are connected by an arm connecting portion 83 provided at the upper end portion.

  The arm connecting portion 83 includes a bottom portion 84 at the center, left and right wall portions 85L and 85R rising from the bottom portion 84, a ceiling portion 86 covering the wall portions 85L and 85R, and the left and right wall portions 85L, The outer wall portions 87 </ b> L and 87 </ b> R are arranged on the outer side of 85 </ b> R and rise from the bottom portion 84.

  An upper steering shaft 88 is stretched vertically between the bottom portion 84 and the ceiling portion 86, and a first spherical bearing 91 is fitted on the upper steering shaft 88, and the vertical position of the first spherical bearing 91 is set. The recesses 93 formed at the tips of the upper arms 13L and 13R are fitted into the outer surface 91g of the first spherical bearing 91 with the spacers 92 and 92 to be regulated interposed therebetween.

  Further, a lower end portion 22b of the handle link 22 is rotatably attached via a pin member 94 between the left wall portion 85L and the left outer wall portion 87L, and between the right wall portion 85R and the right outer wall portion 87R, A lower end portion 22b of the handle link 22 is rotatably attached via a pin member 94.

  That is, the upper arms 13L and 13R are provided at the tips thereof with an upper steering shaft 88 that supports the upper portions of the knuckle arms 21L and 21R in a swingable and steerable manner. The upper steering shaft 88 is provided with knuckle arms 21L and 21R. A first spherical bearing 91 that is supported to be steerable and swingable is disposed, and an upper arm 13L having a recess 93 that fits with the outer surface 91g of the first spherical bearing 91 is disposed around the first spherical bearing 91. A 13R coupling portion is arranged. The upper steering shaft 88 includes a shaft portion 88z and a nut portion 88n.

  In addition, a handle link 22 for transmitting a steering force to the knuckle arms 21L and 21R from the side via pin members 94 and 94 including bolts 94b and 94b and nuts 94n and 94n is provided on the upper portions of the knuckle arms 21L and 21R. Is attached.

  FIG. 7 is an operation explanatory view and a comparative example diagram of the steering shaft provided at the upper end portion and the lower end portion of the knuckle arm according to the present invention. In the embodiment, a tilting mechanism is interposed at the upper and lower end portions of the knuckle arms (reference numerals 21L and 21R in FIG. 3), and in the comparative example, the tilting mechanism is interposed only at the upper end portions of the knuckle arms 21L and 21R.

  (A) is a figure explaining an Example, and the bearings for axles (code | symbol 77 of FIG. 5), the hub main body (code | symbol 76 of FIG. 5), and a lower steering shaft (FIG. 5) are shown in the lower end part of the knuckle arms 21L and 21R. 5 is provided with a second spherical bearing 82, and upper end portions of the knuckle arms 21L and 21R are provided with a first spherical bearing 91 via an upper steering shaft (reference numeral 88 in FIG. 6). It has been. For this reason, when the front wheel (reference numeral 16 in FIG. 5) receives force, the angle of the upper end with respect to the horizontal plane can change from θa11 to θa21, and the angle of the lower end can change from θa12 to θa22. . That is, angular displacement is possible at the upper and lower ends of the knuckle arms 21L and 21R. In the figure, (A) shows the state of the turning shaft 95 before receiving the force from the front wheel, and (B) shows the state of the turning shaft 95 after receiving the force from the front wheel.

That is, knuckle arms 21L and 21R are attached to the body frame side via first and second spherical bearings 82, and a line connecting these spherical bearings 82 and 91 is connected to a turning shaft 95 of a front wheel (reference numeral 16 in FIG. 3). The upper ends of the knuckle arms 21L and 21R are provided to be swingable and turnable on the vehicle body side, and the lower ends of the knuckle arms 21L and 21R are provided to be swingable and turnable on the vehicle body side.
As described above, the axis of the turning shaft 95 is a virtual line. The axis of the turning shaft 95 and the axis of the upper steering shaft 88 do not necessarily coincide with each other. Further, the axis of the turning shaft 95 does not necessarily coincide with the axis of the lower steering shaft 63.

  (B) is a figure explaining a comparative example, and the tilt adjustment mechanism of the knuckle arms 21L and 21R is provided only at the upper end of the knuckle arm. For this reason, when the front wheel axle receives force, the angle of the upper end with respect to the horizontal plane can be changed from θb1 to θb2, but the angle of the lower end is not provided with a tilt adjustment mechanism. It cannot be changed.

  Returning to (a), the upper and lower ends of the knuckle arms 21L and 21R are configured to be swingable so that the forces received by the front wheels 16 are received by the upper and lower ends of the knuckle arms 21L and 21R. did. Therefore, the amount of displacement of the vehicle body relative to the force can be increased, and the flexibility of the vehicle can be increased. In addition, since the movable portion has a simple and compact structure, the inertia can be reduced, and the maneuverability and turning performance of the vehicle can be further enhanced.

FIG. 8 is a view for explaining the structure and operation of a steering stopper provided in the hub steering mechanism.
In (a), on the upper surface 62a of the lateral member 62, stopper portions 96, 96 are provided to restrict the hub body 76 from being at a steering angle α or more at predetermined positions on the left and right.
In (b), the hub body 76 is formed with pin portions 97 that abut against the stopper portions 96, 96.

In other words, the hub steering mechanism 20 is provided with a steer stopper 98 that includes stopper portions 96 and 96 and a pin portion 97 and restricts the steering angle of the front wheel 16.
Since the steer stopper 98 is attached to the hub steering mechanism 20, the front wheel steering apparatus with stopper can be configured without increasing the number of parts related to the handle link 22. Therefore, it is possible to reduce the component cost.

FIG. 9 is an exploded perspective view of the front portion of the motorcycle according to the present invention, and both end portions of the transverse member 62 are provided via second fastening members 102 (... indicates a plurality, the same applies hereinafter). Are supported by the left and right lower arms 15L and 15R. A cross member 75 is stretched between the left and right lower arms 15L and 15R.
Between the hub body 76 and the front wheel 16, two rows of axle bearings 77, 77 are arranged on the left and right. A seal member 80 is disposed between the axle bearing 77 and the knuckle arm.

Further, the left and right knuckle arms 21L and 21R are attached to and detached from the hub body 76 by first fastening members 101... (Only the reference numeral 101 on the right side of the drawing is shown) whose lower ends extend in the vehicle width direction. The upper end portion of the right knuckle arm 21R is detachably provided on the arm connecting portion 83 by third fastening members 103... Extending in the vehicle width direction.
The lower arms 15L and 15R are second fastening members 102... That extend inward from the outside of the vehicle and are detachably attached to the lateral member 62.

  During maintenance such as replacing the tire of the front wheel 16, the first fastening members 101 are removed from the outside of the vehicle, the knuckle arms 21L and 21R are removed from the hub body 76, and the third fastening members 103 are ... And remove the knuckle arm 21R from the vehicle. The front wheels 16 can be removed by removing the second fastening members 102... From the outside of the vehicle and removing the lower arms 15L, 15R from the lateral member 62.

  For this reason, even with a vehicle body having the hub steer mechanism 20, there is no concern that the detachability of the tire attached to the front wheel 16 will be reduced, and there is no concern that the maintainability of the front wheel 16 and its surroundings will be impaired.

The operation of the motorcycle front structure described above will be described next. First, the operation of front wheel steering will be described, then the force absorption operation of the front portion of the motorcycle will be described, and finally the operation of the left and right arm portions will be described.
First, the operation of front wheel steering will be described with reference to FIGS.

When the front wheel 16 is steered, if the steering handle 23 is rotated to the left or right, the steering force is transmitted to the left and right knuckle arms 21L and 21R via the handle link 22. The knuckle arms 21L and 21R rotate with a line connecting the center of the first spherical bearing 91 and the center of the second spherical bearing 82 as a turning shaft 95, and the axle bearing 77 is provided on the knuckle arms 21L and 21R. The front wheel 16 attached to the vehicle can be rotated to the right or the front wheel 16 can be steered left and right by the maximum angle α.
The distance between the turning shaft 95 and the rotation center point (reference numeral 79 in FIG. 5) of the front wheel (reference numeral 16 in FIG. 5) is a so-called offset, and according to this embodiment, this offset is set to an arbitrary amount. By doing so, it is possible to make the steerability optimal characteristics.

Next, the force absorbing action at the front of the vehicle will be described.
FIG. 10 is an explanatory diagram of the operation of the front portion of the motorcycle according to the present invention.
In (a), it is a state when the front wheel 16 is not receiving force from the road surface.
In (b), when the front wheel 16 receives a force in the direction of the arrow b, a force in the direction of the arrow p is applied to the knuckle arms 21L, 21R (only the reference numeral 21L on the front side), and the front upper swing shafts 12L, 12R. The upper arms 13L and 13R (only the front side reference 13L is shown) swing around the front (only the front side reference 12L is shown), and the front lower swing shafts 14L and 14R (only the front side reference 14L are shown). ) Swings around the lower arms 15L and 15R (only the reference numeral 15L on the near side is shown). At this time, a force in the direction of arrow q is applied to the rod member 69.
In (c), it is a state when the front wheel 16 receives a larger force than in (b), and the rod member 69 is further pulled upward.

  FIG. 11 is an operation diagram of the front cushion mechanism of the motorcycle according to the present invention, and FIGS. 11 (a) to 11 (c) correspond to FIGS. 10 (a) to 10 (c), respectively. For example, FIG. 11A corresponds to FIG.

In (a), no force is applied to the rod member 69.
In (b), when the front wheel 16 receives a force, a force in the direction of the arrow q is applied to the rod member 69, and a force for contracting the front cushion unit 61 in the direction of the arrow r via the front link 71 is generated. Take it.

In (c), a greater force is applied to the rod member 69 than in (b), and a force is applied to shrink the front cushion unit 61 in the direction of the arrow r.
When the force is no longer applied, the front cushion unit 61 applies a force in the direction opposite to the arrow r to the front link 71, and the force applied to the front of the vehicle is reduced by trying to return to the position (a). Can be absorbed.

  The front cushion unit 61 changes its direction approximately 90 ° from the direction in which the occupant is seated and is disposed horizontally in the vehicle width direction, so that the force received by the front wheel 16 is directly transmitted to the occupant in the size and direction. It becomes difficult. Since it is difficult for the force to be directly transmitted to the occupant, the posture of the occupant is less changed and the maneuverability of the vehicle can be further improved.

  Referring to FIGS. 3 to 6, upper steering shaft 88 and first spherical bearing 91 for supporting the upper portions of knuckle arms 21L and 21R so as to be steerable and swingable are provided at the tips of upper arms 13L and 13R. In addition to the axial force of the upper steering shaft 88, the upper steering shaft 88 and the first spherical bearing 91 support the axial force in a swingable manner.

In the conventional example, a plurality of arms are provided between the front wheel and the vehicle body frame in order to ensure the support rigidity of the front wheel. In addition, on the upper part of the knuckle arm, for example, a ball joint and a link mechanism are provided to support an axial force and a force in the direction around the shaft so as to be swingable.
That is, the front wheel and the vehicle body frame are connected by a plurality of arms, and an upper arm having a link mechanism is provided on the upper part of the knuckle arm, resulting in a large number of parts.

  In this regard, in the present invention, since the upper steering shaft 88 and the first spherical bearing 91 are provided above the knuckle arms 21L and 21R, the number of parts can be reduced above the knuckle arms 21L and 21R. it can.

Further, since the upper steering shaft 88 and the first spherical bearing 91 provide sufficient support rigidity in the steering shaft direction and the direction around the steering shaft, the number of arms that support the front wheels 16 can be reduced to one. If the link mechanism becomes unnecessary and the number of arms supporting the front wheels is reduced, the number of parts can be reduced, and the front support structure can be configured more simply.
As a result, it is possible to reduce component costs and assembly man-hours.

Lastly, the operation of the left and right arm portions will be described. FIG. 12 is an operation diagram illustrating that the left and right arm portions receive the force applied to the front wheels evenly.
An upper end portion 69t of the rod member 69 that transmits a force to the front cushion unit 61 is connected to a substantially V-shaped center forming the arm portions 13L and 13R. For this reason, the force F applied to the arm portions 13L and 13R is received at the center of the vehicle. Further, since the lower end 69 b of the rod member 69 is connected to the front link 71, the force F is transmitted to the front cushion unit 61 by the rod member 69. At this time, since the force F applied to the arm portions 13L and 13R is received at the center of the vehicle, the force F can be absorbed with a good left-right balance.

  Further, the arm portions 13L and 13R are substantially V-shaped in a plan view and are arranged symmetrically in the vehicle width direction so that force (or load) is applied to the center of the V-shape. , 13R is unlikely to act on the load. Since it is difficult for an uneven load to act on the arm portions 13L and 13R, the rigidity required for the arm portions 13L and 13R can be reduced as compared with the case where the uneven load is considered. If the rigidity of the arm portions 13L and 13R can be reduced, the arm portions 13L and 13R can be reduced in size and weight.

  FIG. 13 is a diagram showing another embodiment of FIG. 4, and the point that differs greatly from FIG. 4 is that the rod member 69 comprises a left rod member 69L and a right rod member 69R, and the front link 71 is a left front link 71L. The left rod member 69L is connected to one end 61a of the front cushion unit 61 via the left front link 71L, and the right rod member 69 is connected to the front portion via the right front link 71. The cushion unit 61 is connected to the other end 61b.

The rod member 69 includes a left rod member 69L and a right rod member 69R. The left rod member 69L is connected to the other end 61b of the front cushion unit 61 via a left front link 71L, and the right rod member 69 is The front cushion unit 61 is connected to one end 61 a via the right front link 71.
That is, the front cushion unit 61 is provided to be extendable and contractable by the left front link 71L and the right front link 71R.

  The forces transmitted to the arm portions 13L and 13R are received by the left and right rod members 69L and 69R, and the forces received by the left and right rod members 69L and 69R are received by the one end 61a and the other end 61b of the front cushion unit 61. 16 can be absorbed in a more balanced manner on the left and right.

FIG. 14 is a diagram of another embodiment of FIG. 1. The difference from FIG. 1 is that the main frame is omitted and the upper arm 13L, 13R, the lower arm and the upper and lower arm members 33L, 33R, 34L, 34R are directly mounted on the engine 26. It is in the point.
By providing the engine 26 with the function of the main frame, the weight of the vehicle can be reduced.

In claim 2, the axle bearing may be configured to be supported by the lateral member.
Further, the inner diameter of the axle bearing may be equal to or smaller than the size of the transverse member when the vehicle is viewed from the side.
Although the present invention is applied to a motorcycle in the embodiment, it can also be applied to a tricycle and can be applied to a general saddle type vehicle.

  The present invention is suitable for the front structure of a motorcycle.

1 is a left side view of a motorcycle according to the present invention. 1 is a front view of a motorcycle according to the present invention. 1 is a plan view of a front portion of a motorcycle according to the present invention. 1 is a perspective view of a front portion of a motorcycle according to the present invention. FIG. 5 is a sectional view taken along line 5-5 of FIG. FIG. 6 is a sectional view taken along line 6-6 of FIG. It is an operation explanatory view and a comparative example figure of a steering shaft with which an upper end part and a lower end part of a knuckle arm concerning the present invention are equipped. It is a figure explaining the structure of the steering stopper provided in a hub steering mechanism, and its effect | action. 1 is an exploded perspective view of a front part of a motorcycle according to the present invention. FIG. 6 is an operation explanatory diagram of a motorcycle front portion according to the present invention. FIG. 6 is an operation diagram of a front cushion mechanism of the motorcycle according to the present invention. It is an effect | action figure explaining receiving the force concerning a front wheel equally by a left-right arm part. It is another Example figure of FIG. It is another Example figure of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Motorcycle, 11 ... Body frame, 13L, 13R ... Upper arm, 15L, 15R ... Lower arm, 16 ... Front wheel, 20 ... Hub steer mechanism, 21L, 21R ... Knuckle arm, 22 ... Handle link, 23 ... Steering handle, 4 ... , 25 ... front cushion mechanism, 26 ... engine, 62 ... lateral member, 63 ... lower steering shaft, 76 ... hub body, 77 ... axle bearing, 82 ... second spherical bearing, 88 ... upper steering shaft, 91 ... First spherical bearing, 101... First fastening member, 102.

Claims (5)

A lower arm and an upper arm that swingably extend forward from the vehicle body frame or the engine, a hub steer mechanism that is provided at a tip of the lower arm and supports a front wheel so as to be steerable, a knuckle arm whose lower part is connected to the hub steer mechanism, In the front structure of a motorcycle, comprising: a steering handle provided on a knuckle arm via a handle link; and a front cushion mechanism that is coupled to the lower arm or the upper arm and absorbs a force received by the front wheel.
The tip of the upper arm and the upper part of the knuckle arm are connected via an upper steering shaft and a first spherical bearing surrounding the upper steering shaft, and the upper part of the knuckle arm is operated by operating the steering handle. A front structure of a motorcycle characterized by being supported so as to be steerable and swingable.   The hub steering mechanism supports a lateral member extending in the left-right width direction on the lower arm, a lower steering shaft extending substantially perpendicular to the lateral member, and the front steering wheel supported on the lower steering shaft so as to be rotatable and steerable. A hub main body and a second spherical bearing provided in the hub main body and supporting the hub main body so as to be steerable and swingable are disposed, and the second spherical bearing is connected to the lateral member and / or the lower steering shaft. The motorcycle front structure according to claim 1, wherein the motorcycle has a front structure.   3. The front structure of a motorcycle according to claim 2, wherein the axle bearing that rotatably supports the front wheel is supported by the knuckle arm.   The motorcycle front structure according to claim 2 or 3, wherein an inner diameter of the axle bearing is larger than a size of the lateral member when the vehicle is viewed from a side.   The knuckle arm is a first fastening member that extends in the vehicle width direction, and is detachably provided on the hub body. The lower arm is a second fastening member that extends inward from the outside of the vehicle, and the transverse member. The motorcycle front part structure according to claim 2, 3 or 4, wherein the front part structure is detachably provided on the motorcycle.

Images