JP6436550B1 - Downhill equipment - Google Patents

Abstract

[Problem] To provide a downhill tool that can realize a skid and can enjoy a dynamic downhill like snow skiing regardless of a field such as turf or grassland.
A roller ski RS includes a pair of left and right left downhill units KL and a right downhill unit KR. The front wheel caster angle αF is set so that the lower end side of the steering shaft 42 of the front wheel 20 is forward of the upper end side, and the rear end of the steering shaft 142 of the rear wheel 120 is forward of the upper end side. A wheel caster angle αR is set. When the player descends, in the left downhill unit KL and the right downhill unit KR, each front wheel 20 turns inward in the turning direction from the neutral state, while each rear wheel 120 turns inward in the turning direction from the neutral state. An angled state in which the steering wheel is not steered and a side slip state in which each front wheel 20 is steered outward in the steering direction from the neutral state and each rear wheel 120 is steered outward in the steering direction from the neutral state. Is possible.
[Selection] Figure 8

Description

  The present invention relates to a downhill tool to be worn on both feet when downhill on a field such as grass or grassland where there is no snow.

  During the winter ski season, many skiers visit the ski area and enjoy skiing. On the snow, the skier repeatedly turns left and right, and slides down the slope. In the turn operation, the skier controls his / her posture. Specifically, the ski is turned by using the deflection of the ski by controlling the load and the weight of the ski through the boot, thereby making the corner of the edge square on the snow. In a general turn, the ski moves to the next turn in the reversed direction while skidding.

  By the way, instead of skiing on snow (hereinafter referred to as “snow skiing”), skiers practicing preparation for downhill skiing in winter and those who want to enjoy the best of downhill skiing. There are people who enjoy field skiing such as grass skiing in the off-season where there is no grass. Others enjoy in-line skating, which mainly runs on flat ground. An example of the inline skate is disclosed in Patent Document 1.

  In the in-line skate described in Patent Document 1, three holders are provided in one row on the lower surface of a base on which a player's foot is placed so as to be able to turn the roller. And the brake and the stopper are arrange | positioned in the position which pinches | interposes the front roller arrange | positioned ahead. Moreover, the brake and the stopper are arrange | positioned in the position which pinches | interposes the back roller arrange | positioned back.

  In the inline skate described in Patent Document 1, when the player stops from the sliding state, the left and right inline skates are opened to the pull stance, and outward loads separated from each other are applied to the front roller and the rear roller. Thereby, each of the front roller and the rear roller has a reverse C shape in plan view, and comes into contact with a brake (rubber pad) disposed on the inside. As a result, the braking force due to the frictional force acts on the front roller and the rear roller, and can be stopped. Also, if the player accidentally applies a load in the direction of closing both feet to the front roller and the rear roller while the player is sliding, the front roller and the rear roller will each have a square shape in plan view, and a stopper placed on the outside. Contact. Thereby, excessive turning of the front roller and the rear roller is prevented. As a result, unintended braking is prevented by preventing a lateral shift (side slip) of the front roller and the rear roller.

JP 2014-76144 A

  By the way, in order to simulate the snow skiing motion in a field ski, it is necessary to cause a skid in which both front and rear wheels are steered in the same direction in the left and right field skis. However, the inline skate described in Patent Document 1 does not intentionally cause skidding due to the design as described above. In other words, even if the front roller and the rear roller on the left side are steered in the same direction and the front roller and the rear roller on the right side are steered in the same direction so as to cause a side slip, One front roller and the rear roller come into contact with the stopper. In this way, with the conventional downhill equipment including the inline skate described in Patent Document 1, the slope of the field such as turf and grassland where there is no snow is realized, such as snow skiing, including dynamic skidding. There was nothing possible.

  The present invention has been made to solve the above problems. That is, the problem is to provide a downhill tool that can realize a skid and enjoy a dynamic downhill like snow skiing regardless of fields such as grass and grassland.

The present invention
A base member on which one foot of the player is placed;
A front wheel disposed on the front side of the base member and rotatable,
In a downhill tool comprising a pair of left and right downhill units having a rear wheel disposed on the rear side of the base member and rotatable,
The front wheel is assembled to the base member so as to be steerable with respect to the ground,
The rear wheel is assembled to the base member so as to be steerable with respect to the ground,
The front wheel caster angle is set so that the lower end side of the steered shaft of the front wheel is ahead of the upper end side,
The rear wheel caster angle is set so that the lower end side of the steered shaft of the rear wheel is more forward than the upper end side thereof,
When the turning axis of the front wheel is arranged ahead of the center of rotation of the front wheel, the amount of offset in the front-rear direction between the turning axis of the front wheel and the center of rotation of the front wheel is defined as “+” When the rear wheel turning shaft is disposed forward of the rear wheel rotation center, the longitudinal offset between the rear wheel turning shaft and the rear wheel rotation center is determined. Is defined as "+"
The offset amount in the front-rear direction between the turning shaft of the rear wheel and the rotation center of the rear wheel is smaller than the offset amount in the front-rear direction between the steering shaft of the front wheel and the rotation center of the front wheel. ,
When the player slides down, the pair of left and right downhill units
A first state in which the front wheels are steered to the inner side in the steered direction than in the neutral state, and the rear wheels are not steered inward in the steered direction from the neutral state;
It is possible to take a second state in which the front wheels steer outward in the steering direction from the neutral state and the rear wheels steer outward in the steering direction from the neutral state. It is a downhill tool.

According to this downhill tool, the left and right front wheels can be steered in a state where the front wheel caster angle is set so that the lower end side of the steered shaft is forward. Furthermore, the left and right rear wheels can also be steered with the rear wheel caster angle set so that the lower end side of the steered shaft is forward. In addition, if a turn operation is performed when the player slides down, the first state where the left and right rear wheels are steered inward in the steering direction while the left and right front wheels are steered inward in the steered direction (squared state) ) Is possible. Thereby, it is possible to turn. Furthermore, if the player performs the pushing operation to the outside in the turning direction, the left and right front wheels are steered to the outside in the turning direction, and the left and right rear wheels are steered to the outside in the turning direction. It is possible to take. Thereby, it is possible to skid. In this way, it is possible to realize skidding regardless of fields such as grass and grassland, and it is possible to enjoy dynamic downhill skiing like snow skiing.
Furthermore, the front-rear offset between the steered shaft of the rear wheel and the center of rotation of the rear wheel is made smaller than the offset of the front-rear direction between the steered shaft of the front wheel and the center of rotation of the front wheel. It is possible to make it difficult for the rear wheels to be steered inward in the steered direction compared to the front wheels. Thus, in the first state, it is possible to easily realize a behavior in which the front wheels are steered inward in the steering direction while the rear wheels are not steered inward in the steered direction. That is, in the first state, it is possible to prevent the rear wheels from being steered inward in the steering direction in the same manner as the front wheels.

In the downhill tool having the above configuration,
The rear wheel caster angle may be larger than the front wheel caster angle.

  According to this downhill tool, as described above, since the offset amount in the front-rear direction of the rear wheel is made smaller than the offset amount in the front-rear direction of the front wheel, the rear wheel steers outward in the steering direction in the second state. May be difficult. Therefore, in order to cope with this, the rear wheel caster angle is made larger than the front wheel caster angle. Thereby, in the second state, it is possible to actively promote the steering toward the outside in the steering direction with respect to the rear wheels. Thus, although the rear wheels do not steer inward in the steering direction in the first state, it is possible to easily realize the behavior in which the rear wheels steer outward in the steering direction in the second state.

In the downhill tool having the above configuration,
The front wheel caster angle is set to 5 degrees or more and 19 degrees or less,
The rear wheel caster angle may be set to 10 degrees or more and 29 degrees or less.

  According to this downhill tool, by setting the front wheel caster angle to 5 degrees or more and 19 degrees or less, the front wheels are steered inward in the steering direction in the first state, and outward in the steering direction in the second state. It is possible to make it easy to steer. On the other hand, by setting the rear wheel caster angle to be not less than 10 degrees and not more than 29 degrees, the rear wheels are prevented from being steered inward in the steering direction in the first state, and are steered outward in the steering direction in the second state. It is possible to make it easy to steer.

  Moreover, in the downhill tool of the said structure, it is good for the said rear-wheel caster angle to be set to 15 to 25 degree | times.

  According to this downhill tool, by setting the rear wheel caster angle to 15 degrees or more and 25 degrees or less, it is possible to avoid feeling that the steering characteristics of the rear wheel are dull or sensitive to the opposite, and to operate appropriately. It is possible to make it.

The present invention
A base member on which one foot of the player is placed;
A front wheel disposed on the front side of the base member and rotatable,
In a downhill tool comprising a pair of left and right downhill units having a rear wheel disposed on the rear side of the base member and rotatable,
The front wheel is assembled to the base member so as to be steerable with respect to the ground,
The rear wheel is assembled to the base member so as to be steerable with respect to the ground,
The front wheel caster angle is set so that the lower end side of the steered shaft of the front wheel is ahead of the upper end side,
The rear wheel caster angle is set so that the lower end side of the steered shaft of the rear wheel is more forward than the upper end side thereof,
The steering axes of the left and right rear wheels are offset so as to be closer to the left and right direction than the steering axes of the left and right front wheels,
When the player slides down, the pair of left and right downhill units
A first state in which the front wheels are steered to the inner side in the steered direction than in the neutral state, and the rear wheels are not steered inward in the steered direction from the neutral state;
It is possible to take a second state in which the front wheels steer outward in the steering direction from the neutral state and the rear wheels steer outward in the steering direction from the neutral state. It is a downhill tool.

According to this downhill tool, the left and right front wheels can be steered in a state where the front wheel caster angle is set so that the lower end side of the steered shaft is forward. Furthermore, the left and right rear wheels can also be steered with the rear wheel caster angle set so that the lower end side of the steered shaft is forward. In addition, if a turn operation is performed when the player slides down, the first state where the left and right rear wheels are steered inward in the steering direction while the left and right front wheels are steered inward in the steered direction (squared state) ) Is possible. Thereby, it is possible to turn. Furthermore, if the player performs the pushing operation to the outside in the turning direction, the left and right front wheels are steered to the outside in the turning direction, and the left and right rear wheels are steered to the outside in the turning direction. It is possible to take. Thereby, it is possible to skid. In this way, it is possible to realize skidding regardless of fields such as grass and grassland, and it is possible to enjoy dynamic downhill skiing like snow skiing.
Also, if the left and right front wheel steering shafts and the left and right rear wheel steering shafts are not offset in the left-right direction, the rear wheels of the downhill unit in the first state (squared state) There is a risk of turning inward in the turning direction. In addition, the rear wheels of the downhill unit may be steered outward in the steering direction. Therefore, according to this downhill tool, the left and right rear wheel turning shafts are offset so as to be closer to the left and right directions than the left and right front wheel turning shafts. Thereby, in a 1st state, it is possible to suppress that the rear wheel of the downhill unit inside turns in the turning direction inside. In addition, it is possible to suppress the rear wheels of the downhill unit on the outside from turning in the turning direction. As a result, in the first state, it is possible to stabilize the turning behavior without turning the left and right rear wheels.

  According to the downhill tool according to the present invention, it is possible to realize a skid regardless of a field such as turf or grassland, and it is possible to enjoy a dynamic downhill like snow skiing.

It is a side view of the roller ski (right downhill unit) which concerns on embodiment of this invention. It is a top view of a right downhill unit. It is an enlarged view of the front steering part shown in FIG. It is sectional drawing along the AA line of FIG. It is an enlarged view of the front steering part shown in FIG. It is a figure explaining each value regarding a tire. It is an enlarged view of the rear steering part shown in FIG. It is a schematic diagram which shows an example of the behavior at the time of roller skiing down in fields, such as a lawn and grassland. It is a schematic diagram explaining the relationship of the force which acts on the tire in a squaring state and a skid state. It is a table | surface which shows the evaluation test of a roller ski. It is a schematic diagram explaining the relationship of the force which acts on the inclined tire. It is a figure when FIG. 11 is seen from the arrow X direction. It is a figure when FIG. 12 is seen from the arrow Y direction. It is a figure which shows the state which the right-and-left rear wheel is offset inside with respect to the central axis of the left-right direction of a base. It is a table | surface which shows the simulation result when a load position is 0 mm. It is a table | surface which shows the simulation result when a load position shall be -8 mm. It is a table | surface which shows the simulation result when a load position is set to +8 mm. It is a figure which shows the state which slides down in a pruke stance. It is a side view of the roller ski of a 1st modification. It is a top view of the roller ski of a 1st modification. It is sectional drawing along the BB line of FIG. It is sectional drawing along CC line of FIG. It is a figure explaining the state by which the front wheel was steered from the neutral state to the right side. It is a figure explaining the case where a front wheel caster angle is changed, and the case where a front wheel offset amount is changed. It is a top view of the roller ski of a 2nd modification. It is a table | surface which shows the evaluation test of the roller ski of a 2nd modification. It is a figure which shows typically the relationship of the force which acts on a tire in the process from a squaring state to a skid state. It is a table | surface and a line graph which show the simulation result at the time of changing offset amount. It is a table | surface and a line graph which show the simulation result at the time of changing a caster angle. It is the table | surface and line graph which show the simulation result in case a caster angle is 10 degree | times and 20 degree | times. It is the table | surface and line graph which show the simulation result at the time of changing the trail of a rear steering part. It is the table | surface and line graph which show the simulation result at the time of changing the trail of a front steering part.

  A roller ski according to an embodiment of the present invention will be described with reference to the drawings. The roller ski RS (downhill tool) of the present embodiment is for sliding down a slope on a field such as grass or grassland where there is no snow, and is a left side downhill unit KL (see FIG. 8A) that is attached to the player's left foot. ) And a right downhill unit KR attached to the player's right foot. Since the left downhill unit KL and the right downhill unit KR have a symmetrical structure, the configuration of the right downhill unit KR will be described below as a representative.

<Configuration of the right downhill unit>
FIG. 1 is a side view of the right downhill unit KR, and FIG. 2 is a plan view of the right downhill unit KR. As shown in FIGS. 1 and 2, the right downhill unit KR includes an operation base 1, a front steering unit 10 disposed in front of the operation base 1 (left side in FIGS. 1 and 2), and an operation base 1. Is also provided with a rear steering section 100 disposed rearward (right side in FIGS. 1 and 2). In the description of the right downhill unit KR, the toe side is “front”, the heel side is “rear”, the thumb side is “left”, and the little finger side is “right”.

  As shown in FIGS. 1 and 2, the operation base 1 includes a base 2 formed long in the front-rear direction and a binding 3 attached to the upper side of the base 2. Since the binding 3 differs depending on the player, the binding 3 is not included as an essential component for the roller ski RS of this embodiment.

  The base 2 is a member on which the player's feet are placed. This base 2 is an aluminum channel material, and has a U-shaped longitudinal section (see FIG. 4). When the right downhill unit KR is grounded to the horizontal ground GR, the height H1 from the horizontal ground GR to the upper surface 2a of the base 2 is set to 50 mm or more and 70 mm or less. In this embodiment, the height H1 is set to 60 mm. The reason why the height H1 is set as described above will be described later.

  As shown in FIG. 1, the binding 3 includes a toe piece 3a for holding the front side (toe side) of the ski boot 4, a heel piece 3b for holding the rear side (heel side) of the ski boot 4, and a heel piece 3b. And a binding brake 3c that is rotatably attached to the vehicle. The binding 3 is attached to the center of the upper surface 2a (attachment surface) of the base 2 in the width direction (left-right direction). The binding brake 3c is provided on both the left and right sides of the heel piece 3b.

  The ski boot 4 is attached to and detached from the binding 3 in the same manner as snow skiing. That is, when the heel piece 3b is pushed down by the heel of the ski boot 4 with the toe of the ski boot 4 held by the toe piece 3a, the ski boot 4 is fixed (mounted) by the two piece 3a and the heel piece 3b. . On the other hand, the ski boot 4 is released from being fixed by lifting the heel of the ski boot 4 away from the heel piece 3b.

  Here, when the ski boot 4 is attached and the heel piece 3b is pushed down, the binding brake 3c extends so as to be substantially parallel to the horizontal ground GR. On the other hand, when the ski boot 4 is not mounted and the heel piece 3b is not pushed down, the binding brake 3c is inclined (rotated) so as to extend obliquely downward toward the rear (two points in FIG. 1). (See chain line). At this time, the rear end of the binding brake 3c contacts the horizontal ground GR, so that the right downhill unit KR can stand on its own.

  Next, the front steering part 10 is demonstrated based on FIGS. FIG. 3 is an enlarged view of the front steering unit 10 shown in FIG. 4 is a cross-sectional view taken along line AA in FIG. As shown in FIGS. 3 and 4, the front steering unit 10 includes a front wheel 20, a fork 30, a support unit 40, a neutral return mechanism 50, and a brake unit 60.

  As shown in FIGS. 3 and 4, the front wheel 20 includes a rubber tire 21, a rim 22 on which the tire 21 is mounted, and a shaft 23 disposed at the rotation center O <b> 1 of the tire 21. The tire 21 can rotate around the shaft 23. The tire 21 of this embodiment has a tire radius R of 75 mm and a tread (width dimension) of 40 mm. As shown in FIG. 4, the rim 22 has a tire 21 mounted on the outer side in the radial direction, and a shaft 23 is assembled on the inner side in the radial direction via a bearing Br1. The shaft 23 extends in the left-right direction and has a screw portion 23a at the left end. The shaft 23 is inserted into a side wall portion 32 of the fork 30 described later, and is fixed to the side wall portion 32 of the fork 30 by screwing a screw portion 23 a to the nut 24.

  The fork 30 is formed by bending a metal plate into a U shape (see FIG. 4), and includes a horizontal upper wall portion 31 and side wall portions 32 extending in the vertical direction on both the left and right sides. In addition, since the side wall part 32 arrange | positioned at the left side and the side wall part 32 arrange | positioned at the right side are the left-right symmetry and are the same structures, below, it demonstrates collectively as the "side wall part 32".

  As shown in FIG. 4, the upper wall portion 31 is assembled to a steering shaft 42 (steering shaft) in a pair of upper and lower portions via a bearing Br2 so as to be rotatable (steerable). Thus, the front wall 20 assembled to the fork 30 can be steered around the steering shaft 42 by rotating the upper wall portion 31 around the steering shaft 42.

  As shown in FIG. 3, the side wall 32 has five insertion holes 32 a on the lower side substantially along the front-rear direction. Each insertion hole 32a is penetrated in the left-right direction, and the shaft 23 mentioned above can be penetrated. In this embodiment, the front wheel offset amount SF can be adjusted by changing the position where the shaft 23 is inserted through the insertion hole 32a. Here, as shown in FIG. 6, the distance from the rotation center of the tire to the axis center of the steering shaft is the offset amount S, and the offset amount S with respect to the front wheels 20 is the “front wheel offset amount SF”. In this embodiment, the front wheel 20 is not offset in the front-rear direction, and the front wheel offset amount SF is set to 0 mm.

  In the present embodiment, when the shaft 23 is inserted through the insertion hole 32a disposed at the forefront, the front wheel offset amount SF is set to −20 mm. Further, when the shaft 23 is inserted through the insertion hole 32a arranged second from the front, the front wheel offset amount SF is set to −10 mm. Further, when the shaft 23 is inserted through the insertion hole 32a arranged third from the front, the front wheel offset amount SF is 0 mm, that is, the front wheel 20 is not offset in the front-rear direction. Further, when the shaft 23 is inserted through the insertion hole 32a arranged at the fourth position from the front, the front wheel offset amount SF is set to +10 mm. Further, when the shaft 23 is inserted through the insertion hole 32a arranged at the rearmost position, the front wheel offset amount SF is set to +20 mm. The shaft 23 and each insertion hole 32a correspond to “adjustment means” that can adjust the front wheel offset amount SF.

  Here, the magnitude of the offset amount S (see FIG. 6) will be described. When the steering shaft 42 (steering shaft) of the front wheel 20 is positioned in front of the center of rotation of the front wheel 20, an offset amount S between the steering shaft 42 of the front wheel 20 and the center of rotation of the front wheel 20 in the front-rear direction. (Front wheel offset amount SF) is defined by “+”. However, for example, when the shaft 23 is inserted through the insertion hole 32 a (see FIG. 3) arranged at the foremost position, the steering shaft 42 of the front wheel 20 is located behind the rotational center of the front wheel 20. Therefore, the front wheel offset amount SF is “− (minus)”. Further, when the shaft 23 is inserted into the insertion hole 32a (see FIG. 3) arranged in the forefront (front wheel offset amount SF = −20 mm), the shaft 23 is inserted into the insertion hole 32a arranged second from the front. Compared with the case of insertion (front wheel offset amount SF = −10 mm), the value of the front wheel offset amount SF is small. In this case, the offset amount S appears to be large for the purpose of viewing, but increases as a negative value, so that the front wheel offset amount SF is treated as being small. These apply similarly to the offset amount S (rear wheel offset amount SR) of the rear wheel 120 described later.

  As shown in FIGS. 3 and 4, the support portion 40 includes a support bracket 41 disposed above the fork 30, a steering shaft 42 extending in the vertical direction, and a pair of left and right connecting frames 43. . The support portion 40 supports the fork 30 and is connected to the front end portion of the base 2 on the rear side.

  The support bracket 41 is formed by bending a metal plate into a U-shape (see FIG. 4), and is a flat plane portion 41a and a bent portion bent downward from the left and right ends on the rear side of the plane portion 41a. 41b. Since the bent portion 41b arranged on the left side and the bent portion 41b arranged on the right side are symmetrical and have the same configuration, they will be collectively described as the “bent portion 41b” below. FIG. 5 is an enlarged view of the front steering unit 10 shown in FIG.

  As shown in FIG. 5, the flat portion 41 a has a substantially rectangular shape that is long in the front-rear direction, and is arranged in parallel with the upper wall portion 31 of the fork 30 as shown in FIG. 4. A brake bracket 61 (described later) is disposed below the upper wall portion 31 of the fork 30. And the upper wall part 31 of the fork 30 is arrange | positioned between the plane part 41a of the support bracket 41, and the brake bracket 61 so that it may be pinched | interposed through the bearing Br2.

  The left and right bent portions 41 b are attached to the respective connection frames 43 in a state of being disposed inside the left and right connection frames 43. As shown in FIG. 3, a large number of connecting holes 41c are formed in the bent portion 41b. The connection holes 41 c penetrate in the left-right direction, and are provided in large numbers so that the positions of the connection bolts 44 that connect the support bracket 41 and the connection frame 43 can be adjusted.

  The steering shaft 42 serves as an axis for turning the front wheel 20. As shown in FIG. 4, the steering shaft 42 is inserted from below into the brake bracket 61, the upper wall portion 31 of the fork 30, and the flat portion 41 a of the support bracket 41. A nut 45 is screwed to a screw portion formed at the upper end of the steering shaft 42. Accordingly, the fork 30 (front wheel 20) can be steered around the steering shaft 42 with respect to the support bracket 41 and the brake bracket 61.

  Thus, in this embodiment, as shown in FIG. 3, the steering shaft 42 extends in the vertical direction so that the lower end is disposed forward of the upper end, and the front wheel caster angle αF is set to 10 degrees. Here, as shown in FIG. 6, the inclination of the axis center of the steering shaft with respect to the perpendicular is the caster angle α, and the caster angle α with respect to the front wheel 20 is the “front wheel caster angle αF”. The caster angle α is defined as “+” when the lower end side of the steering shaft is disposed forward of the upper end side.

  Each connection frame 43 extends substantially in the vertical direction, and is welded to the front end portion of the base 2 at the lower end. In addition, two attachment holes 43 a are formed on the upper side of each connection frame 43 in the vertical direction. The support bracket 41 is attached to the connection frame 43 by inserting the connection bolts 44 through the attachment holes 43 a and the connection holes 41 c of the bent portions 41 b of the support bracket 41. In the present embodiment, as described above, a large number of the connection holes 41c are provided in the bent portion 41b of the support bracket 41. Therefore, the posture of the support bracket 41 is changed by changing the connection holes 41c through which the connection bolts 44 are inserted. be able to. As a result, the front wheel caster angle αF can be set to, for example, 0 degrees, 5 degrees, 15 degrees, and 20 degrees other than 10 degrees.

  The neutral return mechanism 50 provides an elastic force for returning to the neutral state when the front wheel 20 (fork 30) is steered around the steering shaft 42 from a neutral state (initial state) where the front wheel 20 (fork 30) is not steered. is there. 3 and 5, the neutral return mechanism 50 includes two pressing pins 51 attached to the upper wall portion 31 of the fork 30 and two locking pins attached to the flat portion 41a of the support bracket 41. 52 and a wire spring 53 that can be locked to each pressing pin 51 and each locking pin 52.

  As shown in FIG. 5, each pressing pin 51 is arranged on both the left and right sides at the front end portion of the upper wall portion 31 of the fork 30. Each pressing pin 51 is inserted into a long hole 31a formed in the upper wall portion 31 of the fork 30 and extends in the vertical direction as shown in FIG. Here, the pressing pin 51 on the left side is referred to as “left pressing pin 51a”, and the pressing pin 51 on the right side is referred to as “right pressing pin 51b”. As shown in FIG. 5, the left pressing pin 51 a is disposed on the left side (lower side in FIG. 5) with respect to the left portion 53 a of the wire spring 53, and the right pressing pin 51 b is the right portion 53 b of the wire spring 53. It is arranged on the right side (upper side in FIG. 5). That is, each pressing pin 51 is disposed outside the wire spring 53.

  As shown in FIG. 5, each locking pin 52 is disposed on both the left and right sides at the front end portion of the flat portion 41 a of the support bracket 41. Each locking pin 52 is inserted into a long hole 41d formed in the flat portion 41a of the support bracket 41, and extends in the vertical direction as shown in FIG. Here, the locking pin 52 on the left side is referred to as a “left locking pin 52a”, and the locking pin 52 on the right side is referred to as a “right locking pin 52b”. As shown in FIG. 5, the left locking pin 52 a is disposed on the left side of the left portion 53 a of the wire spring 53, and the right locking pin 52 b is on the right side of the right portion 53 b of the wire spring 53. Has been placed. That is, each locking pin 52 is disposed outside the wire spring 53.

  The wire spring 53 is a metal wire, and is an elastic member obtained by deforming a wire having a wire diameter of about 3 mm into a substantially U shape. The wire spring 53 is locked to each pressing pin 51 and each locking pin 52 in the initial state. Here, for example, if the fork 30 (front wheel 20) tries to steer in the direction of the arrow X1 in FIG. 5, the left pressing pin 51a presses the left portion 53a of the wire spring 53 in the direction of the arrow X1 in FIG. Thereby, the fork 30 is steered in the direction of the arrow X1 in FIG. Thereafter, when the force in the direction of the arrow X1 is released, the wire spring 53 tries to return to the original position by the elastic force. At this time, the left portion 53a of the wire spring 53 returns to the original position until it is locked to the left locking pin 52a, and the fork 30 (front wheel 20) returns to the neutral state (initial state). Note that, when the fork 30 turns in the direction of the arrow X2 in FIG.

  Thus, in this embodiment, the neutral return mechanism 50 prevents the front wheel 20 (fork 30) from being excessively steered with a slight steering force, thereby improving the straight running stability. Further, by adjusting the insertion position of each pressing pin 51 with respect to the long hole 31a and the insertion position of each locking pin 52 with respect to the long hole 41d, it is possible to adjust the elastic force by the wire spring 53. Thereby, it is possible to finely adjust the operation feeling by adjusting the restoring force of the front wheel 20 to the neutral state.

  The brake unit 60 regulates the steering of the front wheels 20 to decelerate or brake the front wheels 20. As shown in FIGS. 3 and 4, the brake unit 60 includes a planar brake bracket 61, a pair of left and right brake support members 62 extending in the vertical direction, and a brake shoe 63 supported by each brake support member 62. have.

  As shown in FIG. 4, the brake bracket 61 is a metal plate disposed below the upper wall portion 31 of the fork 30, and the steering shaft 42 is inserted as described above. As shown in FIG. 5, the brake bracket 61 has substantially V-shaped notches 61a at the left and right ends on the rear side. Each notch 61 a is for preventing the side wall portion 32 of the fork 30 from interfering with the brake bracket 61 when the fork 30 is steered around the steering shaft 42. Further, as shown in FIG. 5, the brake bracket 61 is fixed to the flat portion 41a of the support bracket 41 via connecting bolts 64 extending in the vertical direction behind the notches 61a (FIG. 3). reference).

  As shown in FIG. 4, each brake support member 62 is disposed at a position slightly separated from the upper portion of the tire 21 in the left-right direction. Each brake support member 62 is a bolt with a male screw, and is fixed to the brake bracket 61 with a nut 65 at the upper end. A brake shoe 63 is mounted except for the upper part of each brake support member 62.

  Each brake shoe 63 is made of a synthetic rubber such as urethane rubber or a resin having wear resistance, and has a cylindrical shape (hollow pipe). Each brake shoe 63 does not come into contact with the upper side surface of the tire 21 as a matter of course in a state in which the fork 30 (front wheel 20) is not steered. Each brake shoe 63 of the present embodiment hits the side surface of the upper portion of the tire 21 when the front wheel 20 is turned about 30 degrees around the steering shaft 42 from the neutral state (when the turning angle of the front wheel 20 becomes 30 degrees). It comes to touch. After the brake shoe 63 and the upper side surface of the tire 21 come into contact with each other, the upper side surface of the tire 21 causes the brake support member 62 and the brake shoe 63 to bend by the force that the tire 21 tries to steer. The rudder angle increases.

  Therefore, as the turning angle of the front wheel 20 becomes larger than 30 degrees, a large frictional resistance force is generated between the upper side surface of the tire 21 and the brake shoe 63. Thereby, it is possible to decelerate or brake the front wheel 20 while suppressing excessive steering of the front wheel 20. In the present embodiment, when the turning angle of the front wheel 20 reaches about 35 degrees, the side wall 32 of the fork 30 comes into contact with the notch 61a (see FIG. 5) of the brake bracket 61, and further turning of the front wheel 20 is performed. Is regulated. That is, the maximum turning angle of the front wheels 20 is set to about 35 degrees.

  In the brake unit 60 of this embodiment, as shown in FIG. 4, the brake bracket 61 is a dual-purpose bracket for attaching the brake support members 62 and for attaching the steering shaft 42. Therefore, since the steering shaft 42 is not a one-side support that is fixed only to the support bracket 41 but a both-side support that is also fixed to the brake bracket 61, the rigidity of the steering shaft 42 can be easily secured. The size of the bearing Br2 can be reduced. As shown in FIG. 3, the two members of the brake bracket 61 arranged in parallel and the flat portion 41 a of the support bracket 41 are coupled by a steering shaft 42 and a connecting bolt 64 to form a two-layer structure. The stress acting on the portion to which the steering shaft 42 is attached is dispersed. Thus, the brake bracket 61 itself also has an effect of increasing rigidity.

  By the way, for example, it is conceivable to form a brake by bonding a plate-shaped brake shoe to a bracket. However, in this configuration, the manufacturing burden due to the use of the adhesive is increased, and the brake shoe is easily peeled off when coming into contact with the tire 21. On the other hand, in the brake part 60 of this embodiment, as described above, a brake is configured by inserting the cylindrical (hollow pipe) brake shoe 63 through the brake support member 62 that is a shaft rod. Therefore, it is easy to manufacture because no separate member such as an adhesive is required. Furthermore, since the brake shoe 63 is attached by insertion, the brake shoe 63 can be prevented from being peeled off by contact with the tire 21.

  Next, the rear steering unit 100 will be described with reference to FIG. However, the rear steering unit 100 is basically the same as the configuration of the front steering unit 10 described above. Therefore, in FIG. 7, members corresponding to the configuration of the front steering unit 10 are denoted by reference numerals 100. Below, it demonstrates centering on a different part from the front steering part 10. FIG.

  In the rear wheel 120, as shown in FIG. 7, the tire 121 can rotate around the rotation center O2. As with the front wheel 20, the rear wheel 120 is not offset in the front-rear direction. That is, the rear wheel offset amount SR is set to “0 mm”. However, the rear wheel offset amount SR can be changed to −20 mm, −10 mm, +10 mm, and +20 mm by changing the position at which the shaft 123 is inserted through the insertion hole 132a. The shaft 123 and each insertion hole 132a correspond to an “adjustment unit” that can adjust the rear wheel offset amount SR. Further, the support portion 40 and the base 2 of the front steering portion 10 and the support portion 140 of the rear steering portion 100 correspond to a “base member” for assembling the front wheels 20 and the rear wheels 120 so that they can be steered.

  In the fork 130, the upper wall portion 131 is assembled to the support bracket 141 of the support portion 140 via the bearing Br2 and the steering shaft 142 (steering shaft). Thereby, the rear wheel 120 (tire 121) can be steered around the axis center Q2 of the steering shaft 142. The connection frame 143 is welded so as to extend obliquely upward toward the rear with respect to the rear end portion of the base 2. The support bracket 141 is attached to the connection frame 143 by inserting the connection bolt 144 through the attachment hole 143 a of the connection frame 143 and the connection hole 141 c of the bent portion 141 b of the support bracket 141. Thereby, in the rear wheel 120, the rear wheel caster angle αR is set to 15 degrees. However, the posture of the support bracket 141 can be changed by changing the connecting hole 141c through which the connecting bolt 144 is inserted. As a result, the rear wheel caster angle αR can be set to, for example, 5 degrees, 10 degrees, 20 degrees, and 25 degrees other than 15 degrees.

  By the way, in this embodiment, as shown in FIG. 2, in the front steering unit 10, the support bracket 41 is attached to the connection frame 43 so as not to be offset in the left-right direction with respect to the center axis P <b> 1 in the left-right direction of the base 2. ing. Therefore, the front wheels 20 (forks 30 and tires 21) attached to the support bracket 41 are also arranged so as not to be offset in the left-right direction with respect to the center axis P1 in the left-right direction of the base 2. As a result, the shaft center Q1 of the steering shaft 42 with respect to the front wheels 20 is disposed on the center axis P1 of the base 2 in the left-right direction and is not offset in the left-right direction.

  On the other hand, as shown in FIG. 2, in the rear steering unit 100, the support bracket 141 is located on the inner side in the left-right direction with respect to the center axis P <b> 1 in the left-right direction of the base 2. 2 is attached to the connecting frame 143 so as to be offset. Specifically, the support bracket 141 is offset inward in the left-right direction by interposing a spacer 145 between the right connecting frame 143 and the right bent portion 141b of the support bracket 141. In the rear steering unit 100 of the right downhill unit KR, as shown in FIGS. 1 and 2, the left bent portion 141b of the support bracket 141 is arranged on the left side (front side in FIG. 1) of the connection frame 143. Yes. In the case of the left downhill unit KL (see FIG. 14) that is symmetrical to the right downhill unit KR, the support bracket 141 is offset to the right end side of the base 2 with respect to the central axis P1 in the left and right direction of the base 2. doing.

  Thus, in the rear steering unit 100, the rear wheels 120 (fork 130 and tire 121) attached to the support bracket 141 are arranged so as to be offset inward with respect to the central axis P1 of the base 2 in the left-right direction. Yes. As a result, the shaft center Q2 of the steering shaft 142 with respect to the rear wheel 120 is offset inward with respect to the center axis P1 of the base 2 in the left-right direction, that is, the shaft center Q1 of the steering shaft 42 with respect to the front wheel 20.

  In the present embodiment, the distance Vx (hereinafter referred to as “left-right direction offset amount Vx”) in which the shaft center Q2 of the steering shaft 142 with respect to the rear wheel 120 is offset in the left-right direction with respect to the center axis P1 is set to 8 mm. ing. As described above, in the roller ski RS of this embodiment (the right downhill unit KR and the left downhill unit KL), the steering shafts 142 of the left and right rear wheels 120 are closer to the left and right directions than the steering shafts 42 of the left and right front wheels 20 are. The reason for this is that the reason for this will be described later.

<Roller ski behavior>
Next, the behavior of the roller ski RS will be described with reference to FIGS. FIG. 8 is a schematic diagram showing an example of behavior when the roller ski RS slides down in a field such as grass or grassland. In FIG. 8, the upper side in the figure shows the mountain side, and the lower side in the figure shows the valley side.

  As shown in FIG. 8A, when the player is moving straight toward the valley side (lower side in FIG. 8) and applying a large load while tilting the posture to the left, the right downhill unit KR and the left side The downhill unit KL tilts leftward from the standing posture (see FIG. 9A). Thereby, the squaring state shown in FIG. In the squaring state, the front wheel 20 of the right downhill unit KR is steered inward in the turning direction (direction indicated by the arrow in FIG. 8B) with respect to the shaft center Q1, and the front wheel 20 of the left downhill unit KL is also turned on. Then, the vehicle is steered (inner steered) toward the inner side of the steered direction with respect to the shaft center Q1.

  In the squaring state (first state), the rear wheel 120 of the right downhill unit KR and the rear wheel 120 of the left downhill unit KL are not turned inward in the turning direction with respect to the axis Q2. This is because if the rear wheels 120 are steered inward in the steered direction, turning to the left is impeded. Therefore, each rear wheel 120 is desirably non-steered without turning. In the squaring state, each rear wheel 120 is allowed to turn slightly outward in the turning direction. However, if each rear wheel 120 is steered to the outside in the steered direction to some extent, turning to the left becomes excessive and control becomes extremely difficult. Therefore, even if each rear wheel 120 is steered (outwardly steered) outward in the steered direction, only slight steering is allowed. Thus, the player can turn to the left depending on the squaring state.

  Here, when the player pushes the right down unit KR and the left down unit KL leftward and performs an extrusion operation to the outside in the turning direction (the lower side in FIG. 8), the skid shown in FIG. It becomes a state. The skid state in this embodiment does not mean a tire slip, but a state that simulates a skid skid. A right downhill unit KR and a left side as shown in FIG. It means the parallel movement of the downhill unit KL to the outside in the turning direction. In the side-sliding state, the front wheel 20 of the right downhill unit KR and the front wheel 20 of the left downhill unit KL are turned outward in the turning direction (direction indicated by the arrow in FIG. 8C) with respect to the shaft center Q1. Further, the rear wheel 120 of the right downhill unit KR and the rear wheel 120 of the left downhill unit KL are also steered outwardly in the turning direction with respect to the shaft center Q2 (the direction indicated by the arrow in FIG. 8C). Thus, since the player can take a skid, it is possible to enjoy dynamic behavior due to skidding even in fields such as grass and grassland.

  In the skidding state, when the turning of the left and right front wheels 20 or the left and right rear wheels 120 is large (when the turning angle is 30 degrees or more), the tires 21 and 121 come into contact with the brake shoes 63 and 163 (see FIG. 4). ). As a result, the tires 21 and 121 are decelerated by the frictional force (braking force) acting on them. Therefore, the player can obtain a sense of turn operation like snow skiing by controlling the braking force while skidding.

  Here, FIG. 9B is a schematic diagram for explaining the relationship between the forces acting on the tires (the front wheels 20 and the rear wheels 120) in the squaring state. FIG. 9C is a schematic diagram for explaining the relationship between forces acting on the tire in a skid state. 9A, 9B, and 9C show the left foot of the player attached to the left downhill unit KL, and shows a case where the player turns to the left as shown in FIG. Since a centrifugal force is generated during turning, the player will incline in the turning direction to balance the left and right, and the tires shown in FIGS. 9A, 9B, and 9C are also on the left (the right side in FIG. 9). ).

  As shown in FIG. 9A, a position where the load (weight) of the player acts on the left downhill unit KL from the sole is defined as “load point A”. A reaction force F acts on the tire from the contact point, and the reaction force F extends toward the load point A. The magnitude of the reaction force F is a quarter of the player's load (weight). Here, the vertical component of the reaction force F is “vertical component force c”, and the horizontal component of the reaction force is “horizontal component force d”. The distance from the lowest end J of the tire to the rotation center O of the tire is the “tire radius R”. Further, the distance from the lowest end J of the tire to the load point A is “the center of gravity height H”. The angle formed between the reaction force F and the tire center line CH is the “load angle θ”.

  In the state shown in FIG. 9A, the tire is tilted inward in the turning direction (right side in FIG. 9), and the ground contact point of the tire is moved outward from the tire center line CH (right side in FIG. 9). The distance from the tire center line CH to the tire contact point is defined as “movement width B”. In the state shown in FIG. 9A, the load point A is not displaced in the left-right direction with respect to the center line CH of the tire.

  When the tire is further tilted from the state shown in FIG. 9A to the angled state shown in FIG. 9B, the load angle θ increases. At this time, the contact point of the tire has moved to the outer end of the tire (the right end in FIG. 9), and the movement width B has increased. At the same time, the player's load is shifted toward the thumb, and the load point A moves from the center line CH of the tire to the outside in the turning direction (left side in FIG. 9). The position of the load point A with respect to the center line CH of the tire is referred to as “load position V”. It can be said that the load position V is an amount by which the position where the player applies the load is moved in the width direction.

  Thereafter, when the player performs the pushing operation to the outside in the turning direction, the skidding state shown in FIG. At this time, the load point A moves to the inside in the turning direction (right side in FIG. 9) with respect to the tire center line CH. For this reason, the load position V shown on the outer side in the turning direction in FIG. 9B is moved on the inner side in the turning direction in FIG. 9C. Thus, the load position V indicating the load point A located inside the turning direction is a negative value. Then, the ground contact point of the tire has moved to the inside of the tire (left side in FIG. 9) and the movement width B is smaller than the state shown in FIG. Thus, in the skid state shown in FIG. 9C, the direction of the load angle θ is reversed and the direction of the horizontal component force d of the reaction force F is reversed as compared to the state shown in FIG. 9B. . Therefore, the load angle θ and the horizontal component force d are negative values.

<Roller ski evaluation test>
Next, an evaluation test of the roller ski RS will be described with reference to FIG. FIG. 10 shows an actual evaluation when the applicant wears the roller ski RS and takes a squaring state or a skid state. However, the roller ski RS used in this evaluation test is different from the roller ski RS of the present embodiment described above, and the steering shaft 142 of the left and right rear wheels 120 is in the left-right direction with respect to the steering shaft 42 of the left and right front wheels 20. It is not offset. That is, the roller ski RS in which the horizontal direction offset amount Vx shown in FIG. 2 is set to “0 mm” is used.

  In FIG. 10A, an evaluation test of the front wheel 20 is shown. The front wheel caster angle αF is changed to 0 degree, 5 degrees, 10 degrees, 15 degrees, and 20 degrees, and the front wheel offset amount SF is set to −10 mm. The case where it changed to 0 mm and 10 mm is shown. FIG. 10B shows an evaluation test of the rear wheel 120. The rear wheel caster angle αR is changed to 0 degrees, 5 degrees, 10 degrees, 15 degrees, and 20 degrees, and the rear wheel offset amount SR is changed. The case where it changed to -10 mm, 0 mm, and 10 mm is shown. Here, as shown in FIG. 6, the trail T is a distance from the position where the shaft center of the steering shaft contacts the ground GR to the ground contact point of the tire. In FIG. 10A, a trail T (front wheel trail TF) for the front wheel 20 is also shown, and in FIG. 10B, a trail T (rear wheel trail TR) for the rear wheel 120 is also shown. The trail T is a value determined based on the caster angle α and the offset amount S.

  10 (A) and 10 (B), “outer rudder” means that the tire is steered (turned) outward in the steered direction with respect to the center of the steering shaft. On the other hand, “inner rudder” means that the tire steers (cuts) inward in the steered direction with respect to the center of the steering shaft. On the other hand, “no steering” means neither an outer rudder nor an inner rudder, and means that no steering is performed. Further, “inner foot rudder” means that a tire disposed on the inner side during turning of the left and right tires is an inner rudder. On the other hand, the “outer foot outer rudder” means that a tire disposed on the outer side during turning of the left and right tires is an outer rudder.

  In the front wheel 20, in the squaring state, as described above, it is preferable that the inner wheel is moderately inner rudder. On the other hand, in a skid state, it is preferable that the steering is moderately appropriate. 10A, when the front wheel caster angle αF is not less than 5 degrees and not more than 15 degrees and the front wheel offset amount SF is not less than −10 mm and not more than 10 mm, both the squaring state and the skid state are “ “O” or “△”.

  As described above, the rear wheel 120 is preferably non-steered in the squaring state. Alternatively, it is allowed to be a slight outer rudder. On the other hand, in a skid state, it is preferable that the steering is moderately appropriate. Referring to FIG. 10B, when the rear wheel caster angle is 5 degrees and the rear wheel offset amount SR is 0 mm, the rear wheel caster angle is 10 degrees and the rear wheel offset amount SR is 0 mm. When the rear wheel caster angle is 15 degrees and the rear wheel offset amount SR is −10 mm, the evaluation is “◯” or “Δ” in both the squaring state and the skid state.

  In the front wheel 20, it is not preferable that the front wheel caster angle αF is 0 degree. This is because the front wheel 20 is easily cut off either inside or outside, resulting in unstable operability. Further, when the front wheel caster angle αF is “−” which is smaller than 0 degree, it is not preferable because it is opposite to the characteristics when “+”. Also, it is not preferable that the front wheel caster angle αF is 20 degrees or more. This is because the force (moment) for turning the front wheel 20 becomes large, and it tends to be excessively cut inward or outward. That is, the front wheel 20 is cut too much with a little operation, and it becomes difficult to adjust the turning radius. The above evaluation is the same for the rear wheel 120. From the above, it is preferable that the front wheel caster angle αF and the rear wheel caster angle αR are set to be not less than 1 degree and not more than 19 degrees.

<Roller ski simulation>
Next, the simulation of the roller ski RS is verified using a dynamic model. FIG. 11 is a schematic diagram for explaining the relationship between forces acting on a tilted tire. “W / 4” in FIG. 11 indicates that one-fourth of the player's weight (60 kg) is acting. As shown in FIG. 11, since the ground contact surface of the tire is curved, when the tire tilts and the contact point moves to the outside of the tire (right side in FIG. 11), the distance between the rotation center O of the tire and the contact point is Rr. It becomes. Since the difference between the distance Rr between the tire rotation center O and the ground contact point and the tire radius R is so small that it can be ignored, R is used instead of Rr in the calculation. Since the other values in FIG. 11 have already been described with reference to FIGS. 9A, 9B, and 9C, description thereof will be omitted.

  FIG. 12 is a view when FIG. 11 is viewed from the direction of the arrow X. The “vertical component force c of the reaction force F” shown in FIG. 12 can be decomposed into a “first component force e” and a “second component force g”. The first component force e is a component extending in the same direction as the steering shaft in the vertical component force c. The second component force g is a component that extends in the direction perpendicular to the steering axis of the vertical component force c.

FIG. 13 is a view of FIG. 12 viewed from the direction of the arrow Y. Here, a moment (steering force) at which the tire is steered (turned) inward in the steered direction is referred to as an inner rudder moment. Moreover, the moment (steering force) by which the tire is steered outward is referred to as an outer rudder moment. Due to the mechanical relationship, the inner rudder moment and the outer rudder moment must be balanced in order to eliminate the rudder. Therefore, it can be expressed by the following [Equation 1].
[Formula 1] Tt × d (inner rudder moment) = B × g (outer rudder moment)

As shown in FIG. 12, Tt can be expressed by the following [Equation 2].
[Equation 2] Tt = Ttk + S = Rsin α + S
Further, as shown in FIG. 11, the horizontal component force d can be expressed by the following [Equation 3].
[Equation 3] d = Fsin θ
12 and 11, the second component force g can be expressed by the following [Equation 4].
[Formula 4] g = c × sin α = (Fcos θ) × sin α
[Equation 1] can be expressed by the following [Equation 5].
[Equation 5] (Rsinα + S) × Fsinθ = B × (Fcosθ) × sinα
Here, the load angle θ can be expressed by the following [Equation 6] as shown in FIG.
[Formula 6] θ = arctan {(B + V) / H}

When the player is going to make a turn (turn) during downhill, the front wheel 20 needs to be steered inward in the steered direction, as shown in FIG. 8B. For this purpose, the inner rudder moment (Tt × d) must exceed the outer rudder moment (B × g). The relationship can be expressed by [Equation 7].
[Expression 7] Tt × d> B × g

  In the squaring state shown in FIG. 9 (B), the inclination of the tire is larger than that in the state shown in FIG. 9 (A), and the movement width B is increased. Further, the load point A that was on the center line CH of the tire has moved outward in the turning direction (left side in FIG. 9), and the load position V has increased. The load angle θ is increased by [Equation 6], the horizontal component force d is increased by [Equation 3], and the inner rudder moment is increased. Although the increase in the movement width B also increases the outer rudder moment, there is an increase in the inner rudder moment exceeding that, so the front wheels 20 are steered inward in the steered direction. At this time, the rear wheel 120 tends to steer inward in the steering direction, but this is not convenient. This is because in the squaring state, the rear wheel 120 is required not to be steered inward in the steered direction. In fact, in the “evaluation of the squaring state” of the evaluation test shown in FIG. 10B, the rear wheel 120 arranged on the inner side during turning is steered inward in the turning direction ( Inner foot rudder). On the other hand, in this evaluation test, the rear wheels 120 arranged on the outer side during turning are not steered inward in the steered direction, but rather steered outwardly in the steered direction (outside the outer leg). Rudder). This is presumed that the load position V may be further increased. The lateral offset amount Vx that solves these will be described later.

When the player attempts to skid during downhill, the tire needs to be steered outward in the steered direction as shown in FIG. For this purpose, the inner rudder moment (Tt × d) must be lower than the outer rudder moment (B × g). The relationship can be expressed by [Equation 8].
[Equation 8] Tt × d <B × g

In the skid state shown in FIG. 9C, the inclination of the tire is smaller than that in the state shown in FIG. 9A, and the movement width B is reduced. Further, the load point A on the tire center line CH moves to the inside in the turning direction (right side in FIG. 9), and the load position V increases in the minus direction. Since the load position V is a negative value, the load angle θ can be expressed by [Equation 9] obtained by modifying [Equation 6].
[Equation 9] θ = arctan {(B−V) / H}

  [Equation 9] reduces the load angle θ, and [Equation 3] decreases the horizontal component force d, and the inner rudder moment decreases. Although the decrease in the movement width B also decreases the outer steering moment, there is a decrease in the inner steering moment that exceeds the outer steering moment, so the tire is steered outward in the steering direction. When the caster angle α is 5 degrees or less and the offset amount S is −10 mm or less (large in the minus direction), the solutions of [Equation 7] and [Equation 8] do not become the intended results. This is because the value of the inner rudder moment component Tt is negative, and operation with this setting must be performed carefully.

  The applicant performed a simulation of the squaring state using the above [Equation 5] and [Equation 6]. In the simulation, the caster angle α is changed to 0 degree, 5 degrees, 10 degrees, 15 degrees, and 20 degrees, and the offset amount S is changed to −20 mm, −10 mm, 0 mm, 10 mm, and 20 mm. The tire radius R is 75 mm, the movement width B (see FIG. 11) is 20 mm, and the load position V (see FIG. 11) is 0 mm. The center of gravity height H is set to 115 mm, and the reaction force F is set to 15 kgf. The simulation does not distinguish between the front wheels 20 and the rear wheels 120, and does not distinguish between the inner tire and the outer tire (left and right). The simulation result by these settings is shown in FIG.

  By the way, in the evaluation test of the rear wheel 120 shown in FIG. 10 (B), the characteristics opposite to the intended ones are obtained when the rear wheel caster angle αR is 15 degrees and the rear wheel offset amount SR is 0 mm. Is shown. That is, in the squaring state, although the rear wheel 120 is desirably non-steered, the tire disposed on the inner side during turning is the inner rudder, whereas the tire disposed on the outer side during turning is disposed on the outer side. The tires that were on the outside were rudder. Therefore, the applicant configured the right downhill unit KR and the left downhill unit KL as shown in this embodiment in order to deal with the above problems.

  That is, as shown in FIG. 14, in the right downhill unit KR, the rear wheel 120 (the shaft center Q2 of the steering shaft 142) is inside (see FIG. 2) with respect to the center axis P1 (see FIG. 2) in the left-right direction of the base 2. 14 on the right side of the player's right foot). In other words, the position where the right foot applies the load from the sole to the rear wheel 120 is shifted outward (left side in FIG. 14, the little finger side of the player's right foot). Similarly, in the left downhill unit KL, the rear wheel 120 (the axis center Q2 of the steering shaft 142) is offset inward (left side in FIG. 14) with respect to the center axis P1 (see FIG. 2) in the horizontal direction of the base 2. doing. In other words, the position where the left foot applies a load to the rear wheel 120 from the sole is shifted to the outside (right side in FIG. 14). In this embodiment, the left-right offset amount Vx shown in FIG. 14 is set to 8 mm as described above.

  In this way, by offsetting the left and right rear wheels 120 closer to the left and right directions than the left and right front wheels 20, in the squaring state, the inner wheel moment is reduced in the rear wheel 120 of the left downhill unit KL, and the right downhill unit. The inner rudder moment increases at the rear wheel 120 of KR. As a result, as shown in FIG. 14, when turning to the left, the rear wheel 120 of the left downhill unit KL disposed inside can suppress the inner rudder and make it non-steered. Further, in the rear wheel 120 of the right downhill unit KR arranged on the outside, the increased inner rudder moment cancels out the outer rudder moment, and can be made unsteered.

  In the left-side downhill unit KL shown in FIG. 14, the horizontal component force d is shown to be small due to the offset to the inside of the rear wheel 120 (left side in FIG. 14). The inner rudder moment is proportional to the horizontal component force d as shown in [Equation 1]. Therefore, it can be seen that the inner rudder moment decreases as the horizontal component force d decreases. On the other hand, in the right downhill unit KR, it is shown that the horizontal component force d is increased due to the offset to the inside of the rear wheel 120 (the right side in FIG. 14). Therefore, it can be seen that the inner rudder moment increases as the horizontal component force d increases.

  FIG. 15 shows a simulation result when the load position V is 0 mm. In FIG. 16, the simulation result of the same conditions as FIG. 15 is shown except that the load position V is −8 mm. FIG. 16 shows a simulation result when the rear wheel 120 is offset inward (left side in FIG. 14) with respect to the center axis P1 in the left-right direction of the base 2 as in the left downhill unit KL shown in FIG. Will be shown. As can be seen from the comparison between FIG. 15 and FIG. 16, it can be seen that the inner rudder moment is reduced by reducing the load position V from 0 mm to −8 mm. Therefore, it has been proved that the rear wheel 120 of the left downhill unit KL can be made rudder by suppressing the inner rudder.

  In FIG. 17, the simulation result of the same conditions as FIG. 15 is shown except that the load position V is +8 mm. FIG. 17 shows a simulation result when the rear wheel 120 is offset inward (right side in FIG. 14) with respect to the central axis P1 of the base 2 in the left-right direction as in the right downhill unit KR shown in FIG. Will be shown. As can be seen from the comparison between FIG. 15 and FIG. 17, it can be seen that the inner rudder moment is increased by increasing the load position from 0 mm to +8 mm. Therefore, it has been proved that the increased inner rudder moment can cancel the outer rudder moment and no steering at the rear wheel 120 of the right downhill unit KR.

<Operational effects of this embodiment>
According to the roller ski RS of the present embodiment, as shown in FIGS. 3 and 7, the front wheels 20 and the rear wheels 120 can be steered around the steering shafts 42 and 142, and the front wheel caster angle αF (10 degrees in this embodiment). ) And the rear wheel caster angle αR (15 degrees in this embodiment) are set to positive values. Then, if the player performs a turn operation when sliding down, as shown in FIG. 8B, the left and right rear wheels 120 are steered in the steered direction while the left and right front wheels 20 are steered inward in the steered direction. It is possible to take a cornering state that does not steer inward. Thereby, it is possible to turn. Further, when the player pushes out to the outside in the turning direction, as shown in FIG. 8C, the left and right front wheels 20 are steered to the outside in the turning direction, and the left and right rear wheels 120 are made to be outside in the turning direction. It is possible to take a skid state of turning. Thereby, it is possible to skid. In this way, it is possible to realize skidding regardless of fields such as grass and grassland, and it is possible to enjoy dynamic downhill skiing like snow skiing. In addition, in the roller ski RS of the present embodiment, not only a side slip state by a parallel stance as shown in FIG. 8C, but also a side slip state by a pull stance as shown in FIG.

  Further, according to the roller ski RS of this embodiment, the steering shafts 142 of the left and right rear wheels 120 are offset inward so as to be closer to the left and right directions than the steering shafts 42 of the left and right front wheels 20 (see FIG. 2 and FIG. 14). The left-right offset amount Vx of the rear wheel 120 of the right downhill unit KR is set to +8 mm, and the left-right direction offset amount Vx of the rear wheel 120 of the left downhill unit KL is set to −8 mm. Thereby, in the squaring state, for example, when turning leftward, it is possible to suppress the rear wheel 120 on the left side downhill unit KL from turning inward in the turning direction. In addition, it is possible to suppress the rear wheel 120 on the right side downhill unit KR on the outside from turning in the turning direction. As a result, it is possible to stabilize the turning behavior without turning the left and right rear wheels 120 in the squaring state.

  Further, according to the roller ski RS of the present embodiment, as shown in FIG. 1, when the roller ski RS is grounded to the horizontal ground GR, the height H1 from the horizontal ground GR to the upper surface 2a of the base 2 is , 50 mm or more and 70 mm or less. Specifically, in this embodiment, the height H1 is set to 60 mm. This is based on the following reason.

  That is, if the height H1 is greater than 70 mm, the binding brake 3c extending obliquely downward toward the rear cannot contact the ground GR when the ski boot 4 is not attached to the binding 3. That is, the roller ski RS can no longer stand on its own. On the other hand, if the height H1 is greater than 70 mm, the position of the center of gravity of the player is higher than that on snow skis. As a result, it becomes impossible to operate with the same feeling as snow skiing. On the other hand, if the height H1 is smaller than 50 mm, the bottom of the base 2 may come into contact with the ground during sliding. The roller ski RS of this embodiment is designed to be able to run not only on summer ski resorts such as grass and grassland, but also on mountain bike downhill courses. Therefore, when the bottom of the base 2 comes into contact with an uneven road surface, the running is hindered. As described above, by setting the height H1 to 50 mm or more and 70 mm or less, the height H1 can be independent and can be operated with the same feeling as a ski on snow, and avoid the grounding of the bottom portion of the base 2 during the sliding. Is possible.

  As mentioned above, although embodiment of roller ski RS which concerns on this invention was described, this invention is not limited to this, A various change is possible in the range which does not deviate from the meaning. Therefore, a modified example will be described below. However, the modification will be described with a focus on differences from the present embodiment, and the description of the same configuration will be omitted.

<Modification>
In this embodiment, the front wheel caster angle αF is set to 10 degrees, and the rear wheel caster angle αR is set to 15 degrees. However, the front wheel caster angle αF and the rear wheel caster angle αR are not limited to the angles described above, and can be changed as appropriate. However, as described in the present embodiment, the front wheel caster angle is based on the stability of the neutral state of the front wheels 20 and the rear wheels 120 and the viewpoint of preventing the front wheels 20 and the rear wheels 120 from being excessively steered (cut). αF and the rear wheel caster angle αR are preferably set to 1 degree or more and 19 degrees or less.

  In this embodiment, the left-right offset amount Vx of the rear wheel 120 of the right downhill unit KR is set to +8 mm, and the left-right direction offset amount Vx of the rear wheel 120 of the left downhill unit KL is set to −8 mm. However, the left-right direction offset amount Vx is not limited to the above values (+8 mm, −8 mm), and can be changed as appropriate. From the viewpoint of suppressing the inner rudder of the rear wheel 120 on the inner side during turning in the squaring state and suppressing the outer rudder of the rear wheel 120 on the outer side during turning, the left-right direction offset amount Vx is even a little. If it is set (for example, Vx = + 1 mm, −1 mm), the effect is obtained. However, in order to achieve a more effective effect, the left-right offset amount Vx with respect to the rear wheel 120 on the inner side during turning is set in the range of −16 mm to −5 mm, and the left and right relative to the rear wheel 120 on the outer side during turning is set. The direction offset amount Vx is preferably set in a range of +5 mm or more and +16 mm or less.

  Further, in this embodiment, the axis center Q1 of the steering shaft 42 with respect to the left and right front wheels 20 is not offset in the left-right direction with respect to the center axis P1 in the left-right direction of the base 2 (see FIG. 2). However, the axis center Q1 of the steering shaft 42 with respect to the left and right front wheels 20 may be offset in the left-right direction with respect to the center axis P1 in the left-right direction of the base 2. However, even in this case, the shaft center Q2 of the steering shaft 142 with respect to the left and right rear wheels 120 may be set to be inside the shaft center Q1 of the steering shaft 42 with respect to the left and right front wheels 20. This is because in the squaring state, the inner wheel can be suppressed more than the front wheel 20 at the rear wheel 120 on the inner side during turning, and the outer steering can be suppressed at the rear wheel 120 on the outer side during turning. . In short, the steering shafts 142 of the left and right rear wheels 120 are offset so as to be closer to the left and right directions than the steering shafts 42 of the left and right front wheels 20 regardless of the arrangement of the steering shaft 42 with respect to the left and right front wheels 20. It should be.

  Further, in the present embodiment, the front wheel offset amount SF can be adjusted by changing the position of the shaft 23 inserted through the insertion hole 32a of the fork 30 (see FIG. 3). However, the front wheel offset amount SF may be adjusted using another configuration (for example, a long hole). The front wheel offset amount SF can be changed in the range of −20 mm, −10 mm, 0 mm, 10 mm, and 20 mm, but may be changed to other values such as 5 mm and −5 mm. The front wheel offset amount SF may be fixed and cannot be changed.

  In this embodiment, the front wheel offset amount SF is set to 0 mm. However, other values may be set. However, as shown in the evaluation test of FIG. 10A, the front wheels 20 are easily steered inward in the steering direction in the squaring state, and the front wheels 20 are steered appropriately in the lateral direction in the side slip state. In order to facilitate this, it is preferable to set the front wheel caster angle αF in the range of 5 degrees to 15 degrees and the front wheel offset amount SF in the range of −10 mm to 10 mm.

  Further, in the present embodiment, the rear wheel offset amount SR can be adjusted by changing the position of the shaft 123 inserted through the insertion hole 132a of the fork 130 (see FIG. 7). However, the rear wheel offset amount SR may be adjusted using another configuration (for example, a long hole). The rear wheel offset amount SR can be changed in the range of −20 mm, −10 mm, 0 mm, 10 mm, and 20 mm, but may be changed to other values such as 5 mm and −5 mm. In this embodiment, the rear wheel offset amount SR is set to 0 mm, but may be set to other values. The rear wheel offset amount SR may be fixed and not changeable.

  Further, in this embodiment, the front wheel caster angle αF can be adjusted by changing the position of the connecting bolt 44 inserted through the connecting hole 41c of the support bracket 41 (see FIG. 3). However, the front wheel caster angle αF may be adjusted using other configurations (for example, a cylinder mechanism or a mechanism for rotating the connecting frame 43). The front wheel caster angle αF may be fixed and cannot be changed.

  Further, in this embodiment, the rear wheel caster angle αR can be adjusted by changing the position of the connecting bolt 144 inserted through the connecting hole 141c of the support bracket 141 (see FIG. 7). However, the rear wheel caster angle αR may be adjusted using another configuration (for example, a cylinder mechanism or a mechanism for rotating the connecting frame 143). The rear wheel caster angle αR may be fixed and cannot be changed.

  In this embodiment, when the roller ski RS is grounded to the horizontal ground GR, the height H1 from the horizontal ground GR to the upper surface 2a of the base 2 is set to 60 mm. However, the height H1 is not limited to 60 mm and can be changed as appropriate. However, if the height H1 is set in the range of 50 mm or more and 70 mm or less from the viewpoint of being able to operate independently and operating with the same feeling as snow skiing and avoiding the bottom of the base 2 from touching during the slide, good.

  Here, in the roller ski RS of the above embodiment, a mechanism (support portions 40, 140) for turning the front wheel 20 or the rear wheel 120 is provided on the outside of the front wheel 20 or the rear wheel 120 (see FIG. 1). However, a mechanism for turning the front wheel 220 or the rear wheel 320 may be provided inside the front wheel 220 or the rear wheel 320 as in the roller ski RSA of the first modification described below.

<First Modification>
Based on FIGS. 19-24, the roller ski RSA of a 1st modification is demonstrated. The roller ski RSA of the first modification includes a right downhill unit KRA and a left downhill unit (not shown) that are symmetrical structures. Hereinafter, the configuration of the right downhill unit KRA will be described as a representative. FIG. 19 is a side view of the right downhill unit KRA, and FIG. 20 is a plan view of the right downhill unit KRA. As shown in FIGS. 19 and 20, the right downhill unit KRA includes an operation base 1A, a front steering unit 10A disposed in front of the operation base 1A (left side in FIGS. 19 and 20), and an operation base 1A. Is also provided with a rear steering section 100A disposed on the rear side (right side in FIGS. 19 and 20).

  Since the operation base 1A has the same configuration as that of the operation base 1 (see FIG. 1) described above, the same reference numerals are given to the constituent members, and description thereof will be omitted. The front steering unit 10A will be described with reference to FIGS. FIG. 21 is a sectional view taken along line BB in FIG. 22 is a cross-sectional view taken along the line CC of FIG. FIG. 23 is a diagram illustrating a state in which the front wheel 220 is steered from the neutral state to the right side.

  In the front steering unit 10A, the front wheel 220 is rotatable. As shown in FIG. 21, the front wheel 220 includes a tire 221, a rim 222 on which the tire 221 is mounted, and a shaft 223. Connection frames 243 are respectively disposed on the left and right sides of the tire 221. As shown in FIG. 19, the connection frame 243 is formed in a substantially U shape, and has a substantially L-shaped arm portion 243a on the front side. The arm portion 243a extends in the up-down direction and is slightly inclined obliquely downward toward the front.

  As shown in FIG. 21, both end portions of a shaft 223 extending in the left-right direction are press-fitted into the lower end portion of each arm portion 243a. Thereby, each arm part 243a and the shaft 223 are assembled | attached integrally. Further, as shown in FIG. 19, a slit-shaped slit 243b extending in the vertical direction is formed at the lower end of the arm portion 243a, and the assembly bolt 247 is penetrated in the front-rear direction with respect to the slit 243b. Is extended.

  As shown in FIG. 21, a holder 241 is assembled inside the rim 222 via a pair of left and right bearings Br3. Each bearing Br3 is disposed coaxially with the rotation center O3 (see FIG. 22) of the tire 221. Therefore, the tire 221 mounted on the rim 222 is rotatable around the rotation center O3 with respect to the holder 241. An annular collar 245 (see FIG. 22) is assembled outside the holder 241 between the left and right bearings Br3.

  As shown in FIGS. 21 and 22, a holder 241 b is formed inside the holder 241, and a support member 242 is stored in the holder 241 b. The support member 242 passes through a shaft 223 extending in the left-right direction, and is integrally assembled with the shaft 223 using a locking bolt 246. That is, the locking bolt 246 is screwed to the support member 242, and the tip of the locking bolt 246 is in strong contact with the peripheral surface of the shaft 223. Due to this contact, the locking bolt 246, the support member 242, and the shaft 223 are integrally assembled.

  And the supporting member 242 is each assembled | attached to the accommodating part 241b of the holder 241 via the bearing Br4 on both upper and lower sides. The support member 242 and each bearing Br4 are arranged coaxially with the shaft center Q3 (steering shaft) shown in FIGS. Thus, the holder 241 can be steered about the axis center Q3 with respect to the support member 242. That is, the front wheel 220 assembled to the holder 241 can be steered about the axis center Q3 with respect to the support member 242 and the shaft 223 (see FIG. 23). Here, although the shaft 223 is inserted through the holder 241 in the left-right direction, the holder 241 can swing about the shaft center Q3 to some extent with respect to the shaft 223. That is, the holder 241 is provided with the relief hole 241a so that the holder 241 and the shaft 223 do not interfere when the holder 241 swings by turning the front wheel 220. As shown in FIG. 23, the escape hole 241a is formed in a tapered shape that becomes wider toward the outside in the left-right direction in order to increase the turning angle of the front wheel 220.

  In the first modification, as shown in FIG. 19, the shaft center Q3 extends in the vertical direction so that the lower end is disposed forward of the upper end, and the front wheel caster angle βF is set to 10 degrees. . And as shown in FIG. 22, the rotation center O4 of the shaft 223 is not arrange | positioned on the rotation center O3 of the tire 221, but is arrange | positioned ahead of the rotation center O3. Thus, the front wheel offset amount SF, which is the distance from the rotation center O3 of the tire 221 to the shaft center Q3 (steering shaft), is set to 10 mm.

  In the front steering section 10A, as shown in FIG. 20, coil springs 253 are attached to the left and right connection frames 243 (each arm section 243a), respectively. Each coil spring 253 extends in the left-right direction, is attached to each arm portion 243a on the outer side in the left-right direction, and can be locked to the holder 241 on the inner side in the left-right direction. Each coil spring 253 performs the same function as the wire spring 53 (see FIG. 5) described above. That is, as shown in FIG. 23, when the front wheel 220 is steered to the right side, the coil spring 253 disposed on the left side contracts. At this time, the coil spring 253 arranged on the left side applies an elastic force so as to turn the front wheel 220 to the left side in an attempt to return to the original state. Thus, the straight spring stability is improved by the coil springs 253 so that the front wheels 220 are not steered excessively with a small steering force.

  In the front steering section 10A, as shown in FIG. 21, brake shoes 263 are attached to the inner sides of the left and right arm sections 243a, respectively. Each brake shoe 263 is composed of a synthetic rubber such as urethane rubber or a resin having abrasion resistance, and performs the same function as the brake shoe 63 (see FIG. 4) described above. That is, as shown in FIG. 23, when the front wheel 220 is steered to the right side, the upper right side surface (see FIG. 21) of the tire 221 abuts on the brake shoe 263 disposed on the right side, The upper left side is in contact with the brake shoe 263 disposed on the left side. As a result, a frictional resistance is generated between the left and right side surfaces of the upper portion of the tire 221 and each brake shoe 263, and the front wheel 220 can be decelerated or braked.

  In the roller ski RSA of the first modification, the front wheel caster angle βF (see FIG. 19) can be adjusted like the roller ski RS described above. Hereinafter, a method for adjusting the front wheel caster angle βF will be described. First, the screwing of the assembly bolt 247 (see FIG. 19) attached to the lower end portion of the arm portion 243a is loosened. As a result, the slit 243b is opened, and the press-fitting of the shaft 223 into the lower end portion of the arm portion 243a is weakened, and the coupled state between the lower end portion of the arm portion 243a and the shaft 223 is weakened. Thereby, as shown in FIG. 22, it is possible to rotate the support member 242 together with the shaft 223 around the rotation center O4 of the shaft. As a result, the support member 242 can be rotated from the posture shown in FIG. 22 to, for example, the posture shown in FIG. FIG. 24A shows a state where the front wheel caster angle βF is set to 30 degrees. Thus, when the assembly bolt 247 is tightened in a state where the posture of the support member 242 is changed, the coupled state between the lower end portion of the arm portion 243a and the shaft 223 is restored. As described above, the front wheel caster angle βF can be changed from 10 degrees to 30 degrees. Although the case where the front wheel caster angle βF is changed to 30 degrees is shown, since the support member 242 can be changed to various postures by rotation, the front wheel caster angle βF is changed steplessly in addition to 10 degrees and 30 degrees. It is possible to make it.

  Further, in the roller ski RSA of the first modified example, the front wheel offset amount SF can be adjusted like the roller ski RS described above. Hereinafter, a method for adjusting the front wheel offset amount SF will be described. With the holder 241, the support member 242, and the shaft 223 not assembled to the front wheel 220 (rim 222), the holder 241 is reversed from the state shown in FIG. 22 to the front and back as shown in FIG. Invert to be. Here, FIG. 24B shows a state where the front wheel offset amount SF is set to −10 mm. Thus, if the holder 241, the support member 242, and the shaft 223 are assembled to the front wheel 220 with the holder 241 reversed so that the front and rear are reversed, the front wheel offset amount SF can be changed from 10 mm to −10 mm. Is possible. In the first modification, the front wheel offset amount SF can be changed only to either 10 mm or -10 mm, but the front wheel offset amount SF can be appropriately changed by changing the holder 241 itself. It is.

  Here, in the roller ski RSA of the first modified example, as shown in FIG. 20, the shaft center Q3 (steering shaft) with respect to the front wheel 220 is offset in the left-right direction with respect to the center axis P2 in the left-right direction of the base 2. Absent. However, the axial center Q3 with respect to the front wheel 220 can be offset in the left-right direction with respect to the central axis P2 of the base 2. A method for adjusting the distance offset in the left-right direction will be described below. First, the screwing of the assembly bolt 247 (see FIG. 19) attached to the lower end portion of the arm portion 243a is loosened. As a result, the slit 243b is opened, and the press-fitting of the shaft 223 into the lower end portion of the arm portion 243a is weakened, and the coupled state between the lower end portion of the arm portion 243a and the shaft 223 is weakened. Thereby, the shaft 223 can be moved in the left-right direction with respect to the lower end portion of the arm portion 243a. Thereafter, the assembled state of the lower end portion of the arm portion 243a and the shaft 223 is restored by tightening the assembly bolt 247 while the front wheel 220 assembled to the shaft 223 is moved in the left-right direction. As described above, it is possible to arbitrarily change the distance in which the axis center Q3 with respect to the front wheel 220 is offset in the left-right direction with respect to the center axis P2 of the base 2.

  Next, the rear steering unit 100A will be described. The configuration of the rear steering unit 100A is basically the same as the configuration of the front steering unit 10A. Accordingly, among the constituent members of the rear steering unit 100A, those that are the same as the constituent members of the front steering unit 10A are denoted by reference numerals in the 300s and the description thereof is omitted. As shown in FIG. 19, the shaft center Q4, which is the turning axis of the rear wheel 320, extends in the vertical direction so that the lower end is disposed forward of the upper end, and the rear wheel caster angle βR is 10 degrees. Is set. Hereinafter, a description will be given focusing on differences from the configuration of the front steering unit 10A.

  As shown in FIG. 20, the shaft center Q4 (steering shaft) for the rear wheel 320 is offset inward in the left-right direction (lower side in FIG. 20) with respect to the center axis P2 in the left-right direction of the base 2. In this first modification, the distance Vx (left-right direction offset amount Vx) at which the shaft center Q4 with respect to the rear wheel 320 is offset in the left-right direction with respect to the center axis P2 is set to 8 mm. Thus, also in the roller ski RSA of the first modified example, the shaft centers Q4 (steering shafts) of the left and right rear wheels 320 are the same as the shaft centers Q3 (steering shafts) of the left and right front wheels 220, similarly to the roller ski RS described above. Is offset closer to the left-right direction.

  As shown in FIG. 20, in the rear steering unit 100A, the rear wheel 320 is offset on the inner side in the left-right direction (the lower side in FIG. 20) with respect to the central axis P2 of the base 2, so While the brake shoe 363 is thick, the brake shoe 363 disposed on the left side is thin. The coil spring 353 arranged on the right side is long in the left-right direction, while the coil spring 353 arranged on the left side is short in the left-right direction.

  The roller ski RSA according to the first modification has been described above, but the operational effects are the same as those of the roller ski RS described above, and thus the description thereof is omitted. However, in the roller ski RSA of the first modified example, the mechanism for turning the front wheel 220 and the rear wheel 320 is exposed by the escape holes 241a and 341a, and dust easily enters. Therefore, there is a demerit that dust resistance is poor as compared with the roller ski RS described above. Furthermore, as compared with the roller ski RS described above, there are many parts to be cut, and there are many members that are required to have high dimensional accuracy. On the other hand, compared with the roller ski RS mentioned above, there exists a merit which can be comprised compactly and can aim at weight reduction.

<Second Modification>
By the way, in the roller ski RS of the above embodiment, the steering shafts 142 of the left and right rear wheels 120 are offset inward so as to be closer to the left and right directions than the steering shafts 42 of the left and right front wheels 20 (see FIGS. 2 and 2). (See FIG. 14). However, like the roller ski RSB (see FIG. 25) of the second modification described below, the right downhill unit KRB and the left downhill unit KLB are provided with the shaft center Q1 of the steering shaft 42 with respect to the front wheel 20 and the steering with respect to the rear wheel 120. The shaft center Q2 of the shaft 142 is disposed on the center axis P1 in the left-right direction of the base 2, and is not offset in the left-right direction.

  The applicant desires that the downhill tool (roller ski) according to the present invention can be applied to various fields such as a paved road surface, turf, and grassland. Here, the result of the evaluation test shown in FIGS. 10A and 10B was the result when the roller ski RS was slid down on the paved road surface. Therefore, the applicant studied that the downhill tool according to the present invention can be applied to grass. Unlike the smooth paved road surface, the grass has many irregularities, so the front wheels 20 and the rear wheels 120 are easily swung from side to side (easily steered). Therefore, in order to prevent the front wheel 20 and the rear wheel 120 from being shaken, a torsional moment is used as a wire spring 53 (see FIG. 5) provided in the front steering unit 10 and a wire spring (not shown) provided in the rear steering unit 100. The one with large (torque) was used.

  Specifically, in the second modification example (turf evaluation test), the wire spring 53 provided in the front steering unit 10 is 0.51 (N · m) when the turning angle of the front wheels 20 is 0 degree. Torque is generated, and when the turning angle of the front wheels 20 is 25 degrees, a torque of 0.85 (N · m) is generated. The wire spring provided in the rear steering unit 100 generates a torque of 0.65 (N · m) when the turning angle of the rear wheel 120 is 0 degree, and when the turning angle of the rear wheel is 25 degree. This generates a torque of 1.38 (N · m).

  In the above configuration (evaluation test on the paved road surface), the wire spring 53 provided in the front steering unit 10 generates a torque of 0.35 (N · m) when the turning angle of the front wheels 20 is 0 degree. However, when the turning angle of the front wheels 20 is 25 degrees, a torque of 0.56 (N · m) is generated. Further, the wire spring provided in the rear steering unit 100 generates a torque of 0.27 (N · m) when the turning angle of the rear wheel 120 is 0 degree, and when the turning angle of the rear wheel is 25 degree. Torque of 0.44 (N · m) was generated.

  With the above, the evaluation test with the roller ski RSB in the second modification will be described based on FIG. FIG. 26 (A) shows an evaluation test of the front wheel 20, in which the front wheel caster angle αF is changed to 5, 10, 15 and 20 degrees, and the front wheel offset amount SF is set to −10 mm, 0 mm, 10 mm. The case where it is changed to 20 mm is shown. FIG. 26B shows an evaluation test of the rear wheel 120. The rear wheel caster angle αR is changed to 10, 15, 20, 25, and 30 degrees, and the rear wheel offset amount SR is changed. The case where it changed to -20 mm, -10 mm, 0 mm, and 10 mm is shown.

  In the evaluation test shown in FIG. 26, the point changed from the evaluation test shown in FIG. 10 is that the front wheel offset angle SF = 20 mm is added to the front wheel 20 except for the case where the front wheel caster angle αF = 0 °. It is. In addition, the rear wheel caster angle αR = 0 ° and 5 ° are excluded from the rear wheel 120, and the rear wheel caster angles 25 ° and 30 ° are added, and the rear wheel offset amount SR = −20 mm. It is added.

  As can be seen from FIG. 26A, the front wheel offset amount SF is a positive value, which is relatively favorable. FIG. 26B shows that the evaluation is relatively favorable when the rear wheel caster angle αR is a positive value and is 15 degrees or more. This is considered to be the following reason. That is, since the wire spring 53 of the front steering unit 10 and the line spring of the rear steering unit 100 having a large torque are used, the front wheels 20 and the rear wheels 120 are difficult to steer. In order to cope with this, it is necessary to increase the caster angle α (see FIG. 6) or the offset amount S (see FIG. 6) to increase the values of the inner rudder moment and the outer rudder moment. Therefore, the front steering unit 10 obtains favorable evaluation by increasing the front wheel offset amount SF to +, and the rear steering unit 100 obtains favorable evaluation by increasing the rear wheel caster angle αR to +. It is thought.

  In addition, if the evaluation test shown in FIG. 26B is compared with the evaluation test shown in FIG. 10B, the evaluation test shown in FIG. The result of “characteristics opposite to the intention” is not seen. This is considered to be due to the use of a wire spring having a large torque as the wire spring 53 of the front steering unit 10 and the wire spring (not shown) of the rear steering unit 100. Increasing the torque (repulsive force) by these wire springs not only has the effect of suppressing the front wheels 20 and rear wheels 120 from being inadvertently steered by disturbances, but also has a sliding down inside the steered direction. It is thought that the effect which suppresses the difference in the characteristic of a unit (inner ski) and the downhill unit (outer ski) in the outer side of a steering direction is also exhibited.

  In the roller ski RS of the above embodiment, the characteristics of “inner foot inner rudder”, “outer foot outer rudder”, and “characteristic opposite to intention” shown in the evaluation test of FIG. Therefore, the steering shafts 142 of the left and right rear wheels 120 are offset inward so that they are closer to the left and right directions than the steering shafts 42 of the left and right front wheels 20 are. However, this method is merely one method for approaching “no steering”, and does not necessarily eliminate the difference in characteristics between the inner ski and the outer ski.

  That is, the difference between the characteristics of the inner ski and the outer ski is mainly due to variations in the operation from the player between the left side and the right side. The variation between the left side operation and the right side operation varies depending on the player's physique, habit, skill level, etc., and therefore it is desirable that it can be adjusted accordingly. That is, in the method of offsetting the steering shafts 142 of the left and right rear wheels 120 in the left-right direction as in the roller ski RS of the above embodiment (see FIGS. 2 and 14), the structure is uniquely determined, and the left-right offset The quantity Vx cannot be easily changed by the player. Therefore, it is possible to easily approximate “no steering” when the torque generated by the wire spring 53 of the front steering unit 10 and the wire spring of the rear steering unit 100 can be adjusted as appropriate.

  In the roller ski RS of the above embodiment and the roller ski RSB of the second modified example, as shown in FIG. 5, the positions of the left pressing pin 51a, the right pressing pin 51b, the left locking pin 52a, and the right locking pin 52b are adjusted. However, the torque generated by the wire spring can be easily changed by replacing the wire spring itself. However, in the second modification, it is not always possible to realize a desired behavior in the squaring state and the skid state only by changing the torque generated by the wire spring.

  Therefore, in the following, a method for suppressing the inner rudder moment generated at the rear wheel 120 in the squaring state will be examined. As described above, in the squaring state, as shown in FIG. 8B, the rear wheel 120 disposed on the inner side during turning (the rear wheel 120 of the downhill unit disposed on the inner side in the turning direction). Although it is desirable that the steering wheel is unsteered, there is a risk that it may become an inner rudder depending on the setting. Here, FIG. 27 schematically shows the relationship between the forces acting on the tire in the process from the squaring state to the skidding state. When the player shifts from the squaring state to the skidding state, the player raises the roller-ski that is tilted (banked) as shown in FIG. 27 (A) → FIG. 27 (B) → FIG. 27 (C). Do.

  FIG. 27A shows a squaring state in which the load position V increases with a value of “+”. Hereinafter, the case of V = 30 in the state shown in FIG. FIG. 27B shows a state in which the player is applying a load at the center in the left-right direction of the downhill units KRB and KLB. That is, the load point A is not displaced in the left-right direction with respect to the center line CH of the tire. Hereinafter, the case of V = 0 as the state shown in FIG. 27B is referred to as “load from the center”. FIG. 27C shows a skid state, where the load position V increases with a value of “−”. Hereinafter, the case of V = −30 as the state shown in FIG. 27C is referred to as “side slip”. In addition, in “squaring” shown in FIG. 27 (A) → “load from the center” shown in FIG. 27 (B) → “slip” shown in FIG. 27 (C), the ground contact point on the outer side (edge) of the tire is Since the tire moves toward the center of the tire, the movement width B changes from “20” → “15” → “10” with the movement of the load position V.

  FIG. 28A shows a simulation result showing the relationship of the external steering force with respect to “squaring”, “load from the center”, and “slip” when the offset amount S is changed to “−5”, “0”, and “5”. It is. Here, the external rudder force means the difference between the external rudder moment and the internal rudder moment. A value of “+” indicates “external rudder”, and a value of “−” indicates “internal rudder”. It means to become. In the simulation result shown in FIG. 28A, the caster angle α is fixed at 15 degrees.

  FIG. 28B shows the results shown in FIG. 28A when the offset amount S = “− 5”, when the offset amount S = “0”, and when the offset amount S = “5”. It is divided into graphs. The vertical axis of the graph shown in FIG. 28 (B) indicates the external steering force, and the horizontal axis shown in FIG. 28 (B) indicates “squaring”, “load from the center”, and “slip” from the left to the right. Show. When the outer rudder force is a value “−”, “inner rudder force (inner rudder moment)” is generated. Hereinafter, when “outer rudder force” and “inner rudder force” are described together, they are simply referred to as “steering force”.

  As shown in FIG. 28 (B), the three line graphs (offset amount S = “− 5”, “0”, “5” straight line) are rising to the right and are on the right side of “load from the center”. Cross at. In other words, the difference between the three line graphs (the difference in steering force) increases toward the left side (“square”) in FIG. 28B and decreases on the right side (“side slip”) in FIG. I can say that. In short, when the value of the offset amount S is changed, it can be said that the change in rudder force due to squaring is greater than the change in rudder force due to skidding. The slope of the line graph becomes gentler as the value of the offset amount S is decreased. In particular, if the line graph with the offset amount S = “− 5” is seen, the internal steering force at the cornering is reduced and approaches “0” compared to the line graph with the offset amount S = “0”. Yes. From the above, it can be seen that when the inner rudder is desired to be reduced in the squaring state, the value of the offset amount S may be set to a value “−” such as “−5”.

  The reason described above is based on the following reason. As can be seen from FIG. 12, when the value of the offset amount S is set to “−”, the trail T decreases. In conjunction with this, the value of Tt also decreases. Tt is an element of the inner rudder moment as shown in the above [Equation 1]. Accordingly, it can be theoretically explained that when the value of the offset amount S is reduced (particularly when the value is “−”), the inner rudder moment is reduced.

  As described above, if the value of the offset amount S is made small (a value of “−” like “−5”), it is possible to prevent the internal steering in the squaring state. In this way, it is possible to solve the problem that the rear wheel 120 arranged on the inner side during turning (the rear wheel 120 of the downhill unit arranged on the inner side in the turning direction) becomes an inner rudder. In the rear wheel evaluation test shown in FIG. 26 (B), if the value of the rear wheel offset amount SR is “−” in the range where the rear wheel caster angle αR is 25 degrees or less, the evaluation of the “corned state” is performed. No "inner rudder" has occurred ("no rudder" or "outer rudder"). Therefore, it can be said from this that the above-mentioned theory has been proved.

  However, reducing the value of the offset amount S has the following problems. That is, by reducing the value of the offset amount S, the slope of the line graph shown in FIG. If it becomes so, the increase in the external steering force by side slip will become small. The fact that the external rudder force in a side slip is small means that it is difficult to appropriately generate a side slip state as shown in FIG. Therefore, the applicant decided to solve the above-mentioned problems by increasing the caster angle α. The reason will be described below.

  FIG. 29A is a simulation result showing the relationship of the external steering force with respect to “squaring”, “load from the center”, and “side slip” when the caster angle α is changed to “10”, “15”, and “20”. is there. In the simulation result shown in FIG. 29A, the offset amount S is fixed at “0”.

  FIG. 29B divides the results shown in FIG. 29A into a case where the caster angle α = “10”, a case where the caster angle α = “15”, and a case where the caster angle α = “20”. It is a graph. The vertical axis of the graph shown in FIG. 29B indicates the external steering force, and the horizontal axis shown in FIG. 29B indicates “squaring”, “load from the center”, and “slip” from the left to the right. Show.

  As shown in FIG. 29B, the three line graphs (straight lines of caster angles α = “10”, “15”, “20”) are ascending to the right and on the left side of “load from the center”. Crossed. That is, the difference between the three line graphs (the difference in steering force) is small on the left side (“square”) in FIG. 29B and larger toward the right side (“side slip”) in FIG. 29B. I can say that. In short, when the value of the caster angle α is changed, it can be said that the change in rudder force due to skidding is greater than the change in rudder force due to squaring. The slope of the line graph becomes steeper as the caster angle α is increased. In particular, when the line graph with the caster angle α = “20” is seen, the external steering force in the side slip is greatly increased as compared with the line graph with the caster angle α = “10”. From the above, it can be seen that when the steering force is increased in the skid state, the caster angle α should be increased.

  Next, the ideal values of the caster angle α and the offset amount S will be examined. In the front wheel evaluation test shown in FIG. 26 (A), it can be seen that favorable evaluation is relatively obtained when the front wheel caster angle αF is in the range of 5 degrees to 15 degrees. And it turns out that favorable evaluation is comparatively obtained in the range whose front-wheel offset amount SF is 0 mm or more and 20 mm or less. Therefore, it is assumed that the front wheel 20 (front steering unit 10) has an ideal value when the front wheel caster angle αF is 10 degrees and the front wheel offset amount SF is 10 mm as an intermediate value in the above-described range.

  Thus, in FIG. 30A, when the caster angle α is 10 degrees and the offset amount S is 10 mm as the ideal value of the front wheel 20 (front steering unit 10), “square corner” and “load from the center”. The simulation result which shows the relationship of the external steering force with respect to "" slip "is shown. In FIG. 30B, the simulation result described above is graphed by a solid line (see “front steering unit”). The vertical axis of the graph shown in FIG. 30B indicates the external steering force, and the horizontal axis shown in FIG. 30B indicates “squaring”, “load from the center”, and “slip” from the left to the right. Show.

  On the other hand, in the rear wheel evaluation test shown in FIG. 26B, it can be seen that favorable evaluation is relatively obtained when the rear wheel caster angle αR is in the range of 15 degrees to 25 degrees. It can be seen that favorable evaluation is relatively obtained when the rear wheel offset amount SR is in the range of -20 mm or more and 0 mm or less. Therefore, in the rear wheel 120 (rear steering unit 100), it is assumed that the rear wheel caster angle αR is 20 degrees and the rear wheel offset amount SR is −10 mm as an ideal value as an intermediate value in the above range. .

  Thus, in FIG. 30B, as the ideal value of the rear wheel 120 (rear steering section 100), when the caster angle α is 20 degrees and the offset amount S is −10 mm, The simulation result which shows the relationship of the external steering force with respect to "load" and "side slip" is shown. In FIG. 30B, the above simulation result is graphed with a broken line (see “rear steering section”).

  As shown in FIG. 30B, in the line graph of the front steering unit, the external steering force is a large value of “−” due to squaring. In other words, it can be seen that the inner steering force has a large value due to squaring. Therefore, it can be said that both the front wheel 20 on the inner side in the turning direction and the front wheel 20 on the outer side in the turning direction can be made “inner rudder” (see FIG. 8B). Moreover, it can be seen from the line graph of the front steering section that the external steering force has a large value due to skidding. Accordingly, it can be said that both the front wheel 20 on the inner side in the turning direction and the front wheel 20 on the outer side in the turning direction can be made “outer rudder” (see FIG. 8C) in the side slip state.

  Further, as shown in FIG. 30B, it can be seen from the line graph of the rear steering section that the external steering force is almost “0” by squaring. Therefore, in the squaring state, it can be said that both the rear wheel 120 inside the turning direction and the rear wheel 120 outside the turning direction can be set to “no steering” (see FIG. 8B). Moreover, it can be seen from the line graph of the rear steering section that the outer steering force has a large value due to skidding. Therefore, it can be said that both the rear wheel 120 on the inner side in the turning direction and the rear wheel 120 on the outer side in the turning direction can be made “outer rudder” (see FIG. 8C) in the side slip state.

  In particular, in FIG. 30B, the value of the external steering force is almost the same due to skidding in the line graph of the front steering section and the line graph of the rear steering section. In other words, in the side-sliding state, the front wheels 20 and the rear wheels 120 generate almost the same external steering moment. As a result, the balance between the front wheels 20 and the rear wheels 120 in the skidding state is good, and the skiing state can be continued without the roller ski RSB turning. From the above, it is proved that the ideal value described above is appropriate.

  By the way, in the above, when viewed from the rear wheel 120 alone, the rear wheel caster angle αR is in the range of 15 degrees to 25 degrees, and the rear wheel offset amount SR is in the range of −20 mm to 0 mm. It was described as preferable. However, the rear wheel caster angle αR and the rear wheel offset amount SR are not necessarily preferable in all the above-described ranges (see FIG. 26B). Therefore, this point will be further examined.

  FIG. 31A is a simulation result showing the relationship of the external steering force with respect to “squaring”, “load from the center”, and “side slip” when the trail T of the rear wheel 120 is changed. Specifically, when the caster angle α = 15 degrees and the offset amount S = −20 mm (Trail T = −0.6 mm), the caster angle α = 15 degrees and the offset amount S = −10 mm (Trail T). = 9.74 mm), the caster angle α = 15 degrees and the offset amount S = 0 mm (trails T = 20.1 mm). When the caster angle α = 20 degrees and the offset amount S = −20 mm (Trail T = 6.01 mm), the caster angle α = 20 degrees and the offset amount S = −10 mm (Trail T = 16.7 mm). In this case, the caster angle α = 20 degrees and the offset amount S = 0 mm (Trail T = 27.3 mm). When the caster angle α = 25 degrees and the offset amount S = −20 mm (Trail T = 12.9 mm), the caster angle α = 25 degrees and the offset amount S = −10 mm (Trail T = 23.9 mm). In this case, the caster angle α = 25 degrees and the offset amount S = 0 mm (Trail T = 35 mm).

  FIG. 31 (B) is a graph of the results shown in FIG. 31 (A). In FIG. 31B, when the caster angle α = 15 degrees and the offset amount S = −20 mm (trailer T = −0.6 mm), a thick (relatively thick) solid line graph ((1) Reference). Further, the case where the caster angle α = 15 degrees and the offset amount S = −10 mm (trailer T = 9.74 mm) is shown by a thick broken line graph (see (2)). Further, the case where the caster angle α = 15 degrees and the offset amount S = 0 mm (trails T = 20.1 mm) is indicated by a thick dashed line graph (see (3)). Further, a case where α = 20 degrees and an offset amount S = −20 mm (trail T = 6.01 mm) is indicated by a thick two-dot chain line graph (see (4)). Further, the case of the caster angle α = 20 degrees and the offset amount S = −10 mm (Trail T = 16.7 mm) is shown by a broken line graph (see (5)) which is thick and has a narrow pitch interval. .

  In FIG. 31B, when the caster angle α = 20 degrees and the offset amount S = 0 mm (trailer T = 27.3 mm), a thin (relatively thin) solid line graph (see (6)). ). Further, the case where the caster angle α = 25 degrees and the offset amount S = −20 mm (trail T = 12.9 mm) is shown by a thin broken line graph (see (7)). Further, a case where the caster angle α = 25 degrees and the offset amount S = −10 mm (trail T = 23.9 mm) is shown by a thin dot-dash line graph (see (8)). Further, a case where the caster angle α = 25 degrees and the offset amount S = 0 mm (Trail T = 35 mm) is shown by a thin two-dot chain line graph (see (9)).

  Here, when the caster angle α = 15 degrees and the offset amount S = −20 mm, the trail T becomes −0.6 mm, which is almost “0”. In this case, the value of the trail T is the smallest in the simulation result shown in FIG. In FIG. 31B, when a thick solid line which is a line graph in this case is seen, it goes down toward the right side of FIG. This means that the side rudder force is smaller in the side slip state than in the squaring state, and it is understood that the player cannot control. Therefore, when the caster angle α = 15 degrees and the offset amount S = −20 mm (trails T = −0.6 mm), it is difficult to say that this is a preferable setting.

  Subsequently, a case where the value of the trail T is larger than “−0.6 mm” will be considered. The case where the value of the trail T is the next largest after “−0.6 mm” is the case where α = 20 degrees and the offset amount S = −20 mm (trailer T = 6.01 mm). In addition, the case where the value of the trail T is the second largest after “−0.6 mm” also means that the value is the second smallest from the bottom among the values of the nine trails T shown in FIG. In FIG. 31 (B), when a thick two-dot chain line which is a line graph in this case is seen, it slightly rises toward the right side of FIG. 31 (B). Therefore, since the outer rudder force is larger in the side-sliding state than in the squaring state, it can be controlled depending on the player, which is an improvement over the thick solid line graph described above. As described above, the minimum value of the trail T applied to the rear wheel 120 is set to 6 mm.

  Next, the largest value of the trail T in the simulation result shown in FIG. The largest value of the trail T is when the caster angle α = 25 degrees and the offset amount S = 0 mm (the trail T = 35 mm). In FIG. 31B, when a thin two-dot chain line which is a line graph in this case is seen, it rapidly rises toward the right side of FIG. This is because the increase / decrease in the inner rudder moment is extremely large, and it means that the change in the characteristics when shifting from the squaring state to the skid state is too large. That is, the roller ski RSB behaves excessively by a slight operation of the player, and control becomes extremely difficult. Therefore, when the caster angle α = 25 degrees and the offset amount S = 0 mm (trailing T = 35 mm), it is difficult to say that the setting is preferable.

  Next, a case where the value of the trail T is smaller than “35 mm” will be considered. The case where the value of the trail T is next smaller than “35 mm” is a case where α = 20 degrees and an offset amount S = 0 mm (trails T = 27.3 mm). Note that the case where the value of the trail T is the next smallest after “35 mm” also means the case where the value of the trail T is the second largest from the top among the values of the nine trails T shown in FIG. In FIG. 31B, when a thin solid line that is a line graph in this case is seen, the slope of the line graph is gentler than that of the thin two-dot chain line described above. This is because the change in increase / decrease in the inner rudder moment is suppressed as the trail T decreases. Therefore, it can be said that it is improved from the thin two-dot chain line graph described above. As described above, the maximum value of the trail T applied to the rear wheel 120 is set to 27 mm.

Thus, when viewed from the rear wheel 120 alone, the range of the trail T is 6 mm or more and 27 mm or less. Thus, there are the following advantages when not specifying in the range of the rear wheel offset amount SR but specifying in the range of the rear wheel caster angle αR and the range of the trail T. That is, as shown in FIG. 12, even if the value of the caster angle α and the value of the offset amount S are the same, the value of the trail T changes when the tire radius R is different. Here, the trail T can be expressed by the following [Equation 10] as shown in FIG.
[Equation 10] T = Sk + Tk
Sk can be expressed by the following [Equation 11].
[Equation 11] Sk = S / cos α
Tk can be expressed by the following [Equation 12].
[Equation 12] Tk = R × tan α
Therefore, the trail T includes not only the elements of the caster angle α and the offset amount S but also the element of the tire radius R. Therefore, there is an advantage of specifying in the range of the trail T instead of the offset amount S in that the factor of the tire radius R can be taken into consideration.

  In the above description, the range of the trail T on the rear wheel 120 has been examined, but in the following, the range of the trail T on the front wheel 20 will be examined. FIG. 32A is a simulation result showing the relationship of the external steering force with respect to “squaring”, “load from the center”, and “side slip” when the trail T of the front wheel 20 is changed. Specifically, when the caster angle α = 5 degrees and the offset amount S = 0 mm (trails T = 6.56 mm), the caster angle α = 5 degrees and the offset amount S = 10 mm (trails T = 16. 6 mm), the caster angle α = 5 degrees and the offset amount S = 20 mm (trails T = 26.6 mm). When the caster angle α = 10 degrees and the offset amount S = 0 mm (Trail T = 13.2 mm), the caster angle α = 10 degrees and the offset amount S = 10 mm (Trail T = 23.4 mm). In some cases, the caster angle α = 10 degrees and the offset amount S = 20 mm (Trail T = 33.5 mm). Also, when the caster angle α = 15 degrees and the offset amount S = 0 mm (Trail T = 20.1 mm), the caster angle α = 15 degrees and the offset amount S = 10 mm (Trail T = 30.4 mm) In some cases, the caster angle α = 15 degrees and the offset amount S = 20 mm (Trail T = 40.8 mm).

  FIG. 32B is a graph of the result shown in FIG. In FIG. 32B, when the caster angle α = 5 degrees and the offset amount S = 0 mm (Trail T = 6.56 mm), a thick (relatively thick) solid line graph (see (1)). Is shown. Further, the case of the caster angle α = 5 degrees and the offset amount S = 10 mm (trails T = 16.6 mm) is shown by a thick broken line graph (see (2)). Further, a case where the caster angle α = 5 degrees and the offset amount S = 20 mm (Trail T = 26.6 mm) is shown by a thick dashed line graph (see (3)). Further, a case where the caster angle α = 10 degrees and the offset amount S = 0 mm (Trail T = 13.2 mm) is shown by a thick two-dot chain line graph (see (4)). Further, the case where the caster angle α = 10 degrees and the offset amount S = 10 mm (trails T = 23.4 mm) is indicated by a broken line graph (see (5)) which is thick and has a narrow pitch interval.

  In FIG. 32B, a thin (relatively thin) solid line graph (see (6)) when the caster angle α = 10 degrees and the offset amount S = 20 mm (trail T = 33.5 mm). ). The case of the caster angle α = 15 degrees and the offset amount S = 0 mm (trails T = 20.1 mm) is shown by a thin broken line graph (see (7)). Further, the case where the caster angle α = 15 degrees and the offset amount S = 10 mm (Trail T = 30.4 mm) is indicated by a thin one-dot chain line graph (see (8)). Further, a case where the caster angle α = 15 degrees and the offset amount S = 20 mm (trail T = 40.8 mm) is shown by a thin two-dot chain line graph (see (9)).

  Here, when the caster angle α = 5 degrees and the offset amount S = 0 mm, the trail T is a relatively small value of 6.56 mm. In this case, the value of the trail T is the smallest in the simulation result shown in FIG. In FIG. 32B, when a thick solid line which is a line graph in this case is seen, it is only slightly raised toward the right side of FIG. Further, since the inner steering force is small in the squaring state, the front wheel 20 is difficult to turn inward in the steering direction. Therefore, when the caster angle α = 5 degrees and the offset amount S = 0 mm (Trail T = 6.56 mm), it is difficult to say that this is a preferable setting.

  Subsequently, a case where the value of the trail T is larger than “6.56 mm” will be considered. A case where the value of the trail T is the next largest after “6.56 mm” is a case where α = 10 degrees and an offset amount S = 0 mm (trails T = 13.2 mm). In addition, the case where the value of the trail T is the second largest after “6.56 mm” also means that the value is the second smallest from the bottom among the values of the nine trails T shown in FIG. In FIG. 32B, when a thick two-dot chain line which is a line graph in this case is seen, the slope of the line graph is steeper than that of the thick solid line described above. And in a squaring state, since the inner rudder force is larger than the thick solid line mentioned above, it becomes easy to cut to the inner side in the turning direction. Therefore, it can be said that this is an improvement over the thick solid line graph described above. As described above, the minimum value of the trail T applied to the front wheel 20 is set to 13 mm.

  Next, the largest value of the trail T in the simulation result shown in FIG. The largest value of the trail T is when the caster angle α = 15 degrees and the offset amount S = 20 mm (trailer T = 40.8 mm). In FIG. 32B, when a thin two-dot chain line, which is a line graph in this case, is seen, it rapidly rises toward the right side of FIG. This is because the increase / decrease in the inner rudder moment is extremely large, and it means that the change in the characteristics when shifting from the squaring state to the skid state is too large. That is, the roller ski RSB behaves excessively by a slight operation of the player, and control becomes extremely difficult. Therefore, when the caster angle α = 15 degrees and the offset amount S = 20 mm (trails T = 40.8 mm), it is difficult to say that this is a preferable setting.

  Subsequently, a case where the value of the trail T is smaller than “40.8 mm” will be considered. When the value of the trail T is the next smallest after “40.8 mm”, α = 10 degrees and the offset amount S = 20 mm (trailer T = 33.5 mm). Note that the case where the value of the trail T is the next smallest after “40.8 mm” also means the case where the value of the trail T is the second largest from the top among the values of the nine trails T shown in FIG. In FIG. 32B, when the thin solid line which is the line graph in this case is seen, the slope of the line graph is gentler than that of the thin two-dot chain line described above. This is because the change in increase / decrease in the inner rudder moment is suppressed as the trail T decreases. Therefore, it can be said that it is improved from the thin two-dot chain line graph described above. As described above, the maximum value of the trail T applied to the front wheel 20 is set to 33 mm.

<Operational effects of the second modification>
According to the roller ski RSB of the second modified example, unlike the roller ski RS of the above embodiment, as shown in FIG. 25, the axis center Q1 of the steering shaft 42 with respect to the front wheels 20 and the axis center Q2 of the steering shaft 142 with respect to the rear wheels 120 Are arranged on the center axis P1 in the left-right direction of the base 2 and are not offset in the left-right direction. Thereby, it is possible not to change the setting of the player but to avoid a structure that is not symmetrical from the initial state. As a result, it is possible to make a simple structure as compared with the roller ski RS of the above form.

  In addition, in the roller ski RSB of the second modified example, the front wheel offset amount SF is specifically set to +10 mm, and the rear wheel offset amount SR is specifically set to −10 mm. Thus, by making the rear wheel offset amount SR smaller than the front wheel offset amount SF, it is possible to make the rear wheel 120 less likely to be an inner rudder than the front wheel 20. Thereby, in the squaring state, while the front wheel 20 becomes the inner rudder, it is possible to realize a behavior in which the rear wheel 120 does not become the inner rudder. That is, in the squaring state, it is possible to prevent the rear wheel 120 from becoming an inner rudder in the same manner as the front wheel 20.

  However, in the roller ski RSB of the second modified example, as described above, since the rear wheel offset amount SR is made smaller than the front wheel offset amount SF, it is difficult for the rear wheel 120 to steer outward in the steered direction in a skid state. There is a fear. In order to deal with this, in the second modification, the front wheel caster angle αF is specifically set to 10 degrees, and the rear wheel caster angle αR is specifically set to 20 degrees. Thus, by making the rear wheel caster angle αR larger than the front wheel caster angle αF, it is possible to increase the external steering moment acting on the rear wheel 120 in a side-sliding state and to actively promote the external steering of the rear wheel 120. Is possible. As described above, while the rear wheel offset amount SR is reduced, the rear wheel caster angle αR is increased, so that the rear wheel 120 does not steer inward in the steering direction in the squaring state, but the rear wheel in the skid state. It is possible to realize a behavior in which 120 steers outward in the steering direction.

  The roller ski RSB of the second modification has been described above, but the other functions and effects are the same as those of the roller ski RS described above, and thus the description thereof is omitted. In the second modification, the front wheel offset amount SF is set to +10 mm and the rear wheel offset amount SR is set to -10 mm. However, it can be appropriately changed to other values. In this case, the rear wheel offset amount SR may be changed within a range that is smaller than the front wheel offset amount SF. This is because in the squaring state, the behavior of the rear wheel 120 and the front wheel 20 can be made different so that the rear wheel 120 does not become an inner rudder like the front wheel 20. In this case, the front wheel offset amount SF is set to a positive value (a value larger than “0”), for example, from the viewpoint of more positively changing the behavior of the front wheel 20 and the rear wheel 120 in the squaring state. The offset amount SR may be in a range of a negative value (a value smaller than “0”).

  In the second modification, the front wheel caster angle αF is set to 10 degrees and the rear wheel caster angle αR is set to 20 degrees, but may be appropriately set to other values. In this case, it is preferable to change the rear wheel caster angle αR within a range in which the rear wheel caster angle αR is larger than the front wheel caster angle αF based on the description in the second modification. This is because it is possible to actively promote the outer steering of the rear wheel 120 in the side-sliding state. In addition, the front wheel caster angle αF may be set to 5 degrees or more and 19 degrees or less, and the rear wheel caster angle αR may be set to 10 degrees or more and 29 degrees or less. This is because it is easy to realize a behavior in which the front wheel 20 is set to the inner rudder in the angled state and is turned to the outer rudder in the side-sliding state, while the rear wheel 120 is made unsteered in the angled state and turned to the outer rudder in the side-sliding state. is there. Further, in the above-described range, the rear wheel caster angle αR is preferably set to 15 degrees or more and 25 degrees or less. This is because the steering characteristics of the rear wheels 120 can be prevented from feeling dull or sensitive, and more appropriate operability can be achieved.

  As described above, the roller ski RS of the present embodiment, the roller ski RSA of the first modified example, and the roller ski RSB of the second modified example have been described, but it is of course possible to carry out by appropriately combining these features.

RS, RSA, RSB ... Roller ski KL, KLB ... Left downhill unit KR, KRA, KRB ... Right downhill unit 10, 10A ... Front steering unit 100, 100A ... Rear steering unit 20, 220 ... Front wheel 120, 320 ... Rear wheel 30 , 130 ... Forks 42, 142 ... Steering shafts αF, βF ... Front wheel caster angles αR, βR ... Rear wheel caster angles SF, SR ... Front wheel offset amount, rear wheel offset amount Vx ... Left-right direction offset amount

Claims (5)

A base member on which one foot of the player is placed;
A front wheel disposed on the front side of the base member and rotatable,
In a downhill tool comprising a pair of left and right downhill units having a rear wheel disposed on the rear side of the base member and rotatable,
The front wheel is assembled to the base member so as to be steerable with respect to the ground,
The rear wheel is assembled to the base member so as to be steerable with respect to the ground,
The front wheel caster angle is set so that the lower end side of the steered shaft of the front wheel is ahead of the upper end side,
The rear wheel caster angle is set so that the lower end side of the steered shaft of the rear wheel is more forward than the upper end side thereof,
When the turning axis of the front wheel is arranged ahead of the center of rotation of the front wheel, the amount of offset in the front-rear direction between the turning axis of the front wheel and the center of rotation of the front wheel is defined as “+” When the rear wheel turning shaft is disposed forward of the rear wheel rotation center, the longitudinal offset between the rear wheel turning shaft and the rear wheel rotation center is determined. Is defined as "+"
The offset amount in the front-rear direction between the turning shaft of the rear wheel and the rotation center of the rear wheel is smaller than the offset amount in the front-rear direction between the steering shaft of the front wheel and the rotation center of the front wheel. ,
When the player slides down, the pair of left and right downhill units
A first state in which the front wheels are steered to the inner side in the steered direction than in the neutral state, and the rear wheels are not steered inward in the steered direction from the neutral state;
It is possible to take a second state in which the front wheels steer outward in the steering direction from the neutral state and the rear wheels steer outward in the steering direction from the neutral state. Downhill tool. The downhill tool according to claim 1 ,
The downhill tool characterized in that the rear wheel caster angle is larger than the front wheel caster angle. The downhill tool according to claim 2 ,
The front wheel caster angle is set to 5 degrees or more and 19 degrees or less,
The rear wheel caster angle is set to 10 degrees or more and 29 degrees or less. The downhill tool according to claim 3 ,
The rear wheel caster angle is set to 15 degrees or more and 25 degrees or less. A base member on which one foot of the player is placed;
A front wheel disposed on the front side of the base member and rotatable,
In a downhill tool comprising a pair of left and right downhill units having a rear wheel disposed on the rear side of the base member and rotatable,
The front wheel is assembled to the base member so as to be steerable with respect to the ground,
The rear wheel is assembled to the base member so as to be steerable with respect to the ground,
The front wheel caster angle is set so that the lower end side of the steered shaft of the front wheel is ahead of the upper end side,
The rear wheel caster angle is set so that the lower end side of the steered shaft of the rear wheel is more forward than the upper end side thereof,
The steering axes of the left and right rear wheels are offset so as to be closer to the left and right direction than the steering axes of the left and right front wheels,
When the player slides down, the pair of left and right downhill units
A first state in which the front wheels are steered to the inner side in the steered direction than in the neutral state, and the rear wheels are not steered inward in the steered direction from the neutral state;
It is possible to take a second state in which the front wheels steer outward in the steering direction from the neutral state and the rear wheels steer outward in the steering direction from the neutral state. Downhill tool.

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