A tiltable motorcycle with two steering wheels and a front deflector.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- PIAGGIO & C SPA
- Filing Date
- 2024-05-23
- Publication Date
- 2026-05-29
Smart Images
Figure 2026517476000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of tiltable motorcycles, i.e., the field of tiltable motorcycles with a saddle for straddle riding, comprising at least one driven rear wheel and two tiltable front steering wheels.
Background Art
[0002] In the field of automobiles, there is an increasing offer of vehicles that combine the characteristics of two-wheeled vehicles with saddle (e.g., motorcycles and scooters) in terms of handling and the stability of four-wheeled vehicles. Such vehicles include three-wheeled motorcycles provided with two front steering wheels and four-wheeled motorcycles generally called QUAD.
[0003] More specifically, the above-mentioned three-wheeled automobiles are provided with two front steering wheels. The front steering wheels are adapted to be steered by a driver using a handlebar and to be tilted or inclined laterally with rolling, i.e., a rolling motion. The rolling motion is an inclined motion centered on an axis substantially directed in the forward direction. The three-wheeled automobile further comprises a driven rear wheel mechanically connected to a motor. The driven rear wheel provides driving torque and thus traction, and the pair of front wheels provides the vehicle's directivity.
[0004] The pair of front wheels is capable of an inclination motion in addition to the steering motion. Also, the pair of front wheels is connected to the vehicle frame by a shock-absorbing suspension that allows a springing motion. With the pair of two front wheels, compared to an automobile having one front wheel, the tiltable vehicle has a pair of front wheels that are doubly supported on the ground, ensuring greater stability similar to that of an automobile.
[0005] The front wheels are connected to each other by a motion mechanism that allows the front wheels themselves to tilt and steer substantially synchronously, for example, by the interposition of one or two four-bar links that connect the front wheels to the front end frame. Such automobiles often have two independent shock-absorbing suspensions. Each suspension comprises an elastic element (spring) and a viscous element (shock absorber).
[0006] While tiltable three-wheeled vehicles (motorcycles) offer many advantages over conventional two-wheeled motorcycles, they also have a drawback: their wider frontal area compared to conventional motorcycles with a single steering front wheel results in greater resistance to forward movement. [Overview of the project] [Problems that the invention aims to solve]
[0007] Therefore, it is desirable to adopt measures aimed at reducing the air resistance of three-wheeled motorcycles, that is, reducing the drag coefficient. [Means for solving the problem]
[0008] The present invention provides a substantially tiltable motorcycle having a saddle. The tiltable motorcycle comprises a frame having a saddle, at least one drive rear wheel, and two steering front wheels. Furthermore, the motorcycle is equipped with a tiltable four-bar linkage. The four-bar linkage connects the left steering front wheel and the right steering front wheel to the frame. This allows these front wheels to perform steering motion, controlled by a steering system connected to the steering front wheels, in addition to tilting motion. Furthermore, the motorcycle is equipped with a shield positioned behind the left steering front wheel, the right steering front wheel, and the four-bar linkage in the forward direction of the motorcycle. To improve the coefficient of air resistance, the shield is provided with a left deflector along the left lateral edge of the shield and a right deflector along the right lateral edge of the shield. Each deflector, together with the shield, forms a channel for transporting air from the front region of the shield toward the left and right sides of the motorcycle, respectively.
[0009] The channels are formed between the shield and each deflector.
[0010] In practice, two deflectors positioned behind the steering front wheel direct the airflow generated by the motorcycle's forward movement, which is caused by the overpressure effect in front of the shield, along each side of the motorcycle, reducing the vorticity of the flow and consequently reducing air resistance during forward movement. In effect, the airflow is directed between the shield and each deflector.
[0011] Further features and embodiments of the present invention are described in the following description and appended claims. [Brief explanation of the drawing]
[0012] The present invention will be better understood by following the description and accompanying drawings illustrating exemplary and non-limiting embodiments of the invention. [Figure 1]This is a side view of a motorcycle according to one embodiment of the present invention. [Figure 2] This is a partial cross-sectional view along line II-II in Figure 1. [Figure 2A] This is a magnified view of a portion of Figure 2. [Figure 3] This is a front view along line III-III in Figure 1. [Figure 4] This is a front view similar to Figure 3, with the fairing (including the shield) removed. [Figure 5] This is a front view of the motorcycle according to the second embodiment, with the steering front wheel removed. [Figure 6] This is a front view similar to Figure 5, with the fairing (including the shield) removed. [Figure 7] This is a front view similar to Figure 6, with the steering front wheels further removed. [Figure 8] Figures 5 to 7 are side views of the motorcycle with the fairing removed. [Modes for carrying out the invention]
[0013] Figures 1 to 4 show a first embodiment of a motorcycle according to the present invention. The motorcycle as a whole is denoted by reference numeral 1.
[0014] The motorcycle comprises a frame 3, a saddle 4 mounted on the frame 3, a drive rear wheel 5, and a pair of steering front wheels indicated by reference numerals 7.1 (left steering front wheel) and 7.2 (right steering front wheel).
[0015] "Right" and "Left" refer to the right and left sides of the motorcycle when the rider is in the riding position. In the attached diagram, arrows L and R indicate the left and right sides of the motorcycle, respectively. F indicates the forward direction (direction of travel), and B indicates the opposite direction. U and D indicate the upward and downward directions of motorcycle 1.
[0016] Motorcycle 1 is equipped with a steering system 9 for controlling the rotational motion of steering wheels 7.1 and 7.2 around their respective steering axes A1 and A2 (Figure 4). The rotational motion of the steering system 9 is transmitted by a steering column 11. A tiltable four-bar linkage device, collectively indicated by reference numeral 13, is connected to this steering column 11. In the illustrated embodiment, the four-bar linkage device 13 comprises a single four-bar link. The four-bar link has a left strut 13.1, a right strut 13.2, an upper cross member 13.3, and a lower cross member 13.4 (Figure 4). The cross members 13.3 and 13.4 are hinged to the frame of motorcycle 1 at the midpoint of each cross member. The hinge point of the upper cross member 13.3 is indicated by reference numeral 13.5. The hinge point of the lower cross member 13.4 is not visible in Figure 4 and is located behind a tilt locking device, collectively indicated by reference numeral 15.
[0017] In other embodiments, the four-bar linkage may be configured and / or positioned in different locations. For example, in Figures 1 to 4, the four-bar linkage 13 is positioned entirely above the steering front wheels 7.1 and 7.2, i.e., higher than the highest point of the steering front wheels 7.1 and 7.2 relative to the ground support point. In other embodiments, however, the four-bar linkage may be positioned between the steering front wheels 7.1 and 7.2, i.e., at least partially housed in a cylindrical volume surrounding the two steering front wheels.
[0018] Furthermore, instead of a single four-bar linkage, the tiltable four-bar linkage system may have two four-bar links, one for each steering front wheel 7.1 and 7.2.
[0019] In the illustrated embodiment, the rotational movement of the steering front wheels 7.1, 7.2 about the steering axes A1 and A2 is transmitted by the steering rod 18 from the steering column 11 to the left support arm 16.1 of the left steering front wheel 7.1 and the right support arm 16.2 of the right steering front wheel 7.2. Arms 17.1 and 17.2 respectively show the suspensions of the left steering front wheel 7.1 and the right steering front wheel 7.2. Each of the suspensions 17.1 and 17.2 includes shock absorbers (viscous elements) 21.1 and 21.2 and springs (elastic elements) 19.1 and 19.2.
[0020] The motorcycle 1 includes a front shield 31 fixed to the frame (FIG. 3). The shield 31 is disposed behind the steering front wheels 7.1 and 7.2 (with respect to the forward direction, i.e., the traveling direction F of the motorcycle 19). Thus, the shield is "forward" with respect to the driver but "rearward" with respect to the steering front wheels 7.1 and 7.2. The shield 31 is removed in FIG. 4 and can be seen particularly in FIGS. 2, 2A, and 3. In the present specification and the appended claims, the shield or front shield is provided as part of a fairing for the motorcycle located behind the steering front wheels 7.1 and 7.2 (with respect to the traveling direction F) and does not extend laterally with respect to the motorcycle or is not provided as part of a fairing located in front of the steering front wheels 7.1 and 7.2.
[0021] The shield 31 includes a left lateral edge 33.1 and a right lateral edge 33.2 (FIG. 2).
[0022] A distinctive feature is that the left deflector 35.1 is mounted along a portion of the left lateral edge 33.1 of the shield 31. The right deflector 35.2 is mounted along a portion of the right lateral edge 33.2 of the shield 31. The left deflector 35.1 and the right deflector 35.2 are symmetrical with respect to the central plane MM of the motorcycle with the saddle (Figure 2). Thus, below, we also refer to a single deflector, generally indicated by reference numeral 35, without intending it to be one or the other of the right deflector 35.2 and the left deflector 35.1.
[0023] In particular, in the embodiments shown in Figures 2 and 2A, each deflector 35 is composed of a curved laminar flow component, i.e., a molded sheet or wing. This sheet extends from a leading edge 37 located in front of the front surface of the shield 31 with respect to the forward direction F of the motorcycle 1, to a trailing edge 39 located on the side of the motorcycle 1 behind the front surface of the shield 31 with respect to the forward direction F of the motorcycle 1. Thus, in practice, each deflector 35 extends at a distance from each of the lateral edges 33.1 and 33.2 of the shield 31.
[0024] As a result, channels, indicated by reference numerals C1 and C2, i.e., air transport channels, are formed between the lateral edges 33.1 and 33.2 of the shield 31 and the respective deflectors 35.1 and 35.2. During travel, the movement of the motorcycle 1 generates an overpressure of air in front of the shield 31. This overpressure generates an airflow FA along the front of the shield 31, directed toward the two lateral edges 33.1 and 33.2 of the shield itself. Due to the presence of the two lateral deflectors 33.1 and 33.2, the airflow FA is directed into channels C1 and C2 formed between the respective lateral edges 33.1 and 33.2 of the shield 31 and the respective deflectors 35.1 and 35.2. The airflow FA is then transported laterally to the motorcycle 1 with a main velocity component parallel to the direction of travel of the motorcycle 1. This reduces the turbulence generated by the shield 31 and reduces the drag coefficient of the vehicle.
[0025] Each of the sheets or wings forming the right deflector 35.2 and the left deflector 35.1 can be fixed to the shield 31 by a spacer 36 (Figure 2A). The spacer 36 may have an aerodynamic shape, for example, an airfoil cross-section with a linear profile code, so as not to generate lift.
[0026] As shown in the attached plan view (Figure 2), the left deflector 35.1 is positioned at least partially behind the left steering front wheel 7.1 with respect to the forward direction F of the motorcycle. Similarly, the right deflector 35.2 is positioned at least partially behind the right steering front wheel 7.2.
[0027] Furthermore, as shown in the plan view (Figure 2) and the side view (Figure 1 or Figure 8), the left deflector 35.1 is positioned at least partially rearward relative to the suspension 17.1 of the left steering front wheel 7.1 (with respect to the forward direction of the motorcycle 1, i.e., the direction of travel F). Similarly, the right deflector 7.2 is positioned at least partially rearward relative to the suspension 17.2 of the right steering front wheel 7.2 with respect to the forward direction of the motorcycle, i.e., the direction of travel. Likewise, as shown in the same plan view, the two deflectors 35.1 and 35.2 are positioned at least partially rearward relative to the tiltable four-bar linkage device 13 with respect to the forward direction of the motorcycle F.
[0028] In some embodiments, as shown in the front view of motorcycle 1 (Figure 3), the left deflector 35.1 is partially visible above the left steering front wheel 7.1, and the right deflector 35.2 is partially visible above the right steering front wheel 7.2. In other words, each deflector 35.1 and 35.2 extends to a position higher than the highest point of their respective steering front wheels, i.e., positioned at a height greater than the diameter of the steering front wheels. More specifically, each deflector 35.1 and 35.2 includes an upper end in direction U that extends above the dimensions of their respective steering front wheels 7.1 and 7.2. The upper ends also remain below the portion of the front fairing CF that defines the wheel arch of each front wheel.
[0029] In the embodiments shown in Figures 1 to 4, each deflector 35 extends over approximately half of the vertical extension of the corresponding lateral edge of the shield 31.
[0030] In other embodiments, the deflectors may have larger vertical extensions. Examples of this are shown in Figures 5 to 8. Here, the same reference numerals assigned to motorcycle parts or elements are equivalent to those shown in Figures 1 to 4. Therefore, a repetition of detailed descriptions is omitted. The main difference between the embodiments in Figures 1 to 4 and those in Figures 5 to 8 is that in the embodiments of Figures 5 to 8, the lateral deflectors 35.1 and 35.2 extend from a substantially equal high position to that of the deflectors in Figures 1 to 4 (approximately the height of the lower cross member 13.4 of the 4-bar link 13) to a lower position than the deflectors in Figures 1 to 4. In Figures 5 to 8, the deflectors extend to approximately the height where the pivots of the steering front wheels 7.1 and 7.2 are located. In this embodiment, each deflector actually extends over most of the vertical extension of the lateral edge of the shield 31, i.e., more than half of it.
[0031] In each embodiment, the left deflector 35.1 and the right deflector 35.2 are positioned at a distance from the shield 31, around the left and right lateral edges 33.1 and 33.2 of the shield, respectively. In this way, channels are defined between the shield 31 and each deflector 35.1 and 35.2 to collect air that tends to accumulate in front of the shield 31, and to direct that air laterally and rearward to the sides of the shield 31 and the motorcycle 1.
[0032] The inlet of the air channel defined in this way is directed, at least in part, towards the central plane of the motorcycle 1, i.e., the area between the front wheels 7.1 and 7.2, and is positioned behind them and in front of the front surface of the shield 31. The outlet of the air channel is directed, at least in part, towards the rear of the motorcycle 1, so as to graze the side of the shield 31.
[0033] Therefore, the deflectors 35.1 and 35.2 are shaped to facilitate airflow from the area of overpressure on the front of the shield 31 caused by the forward movement of the motorcycle 1 to the area of lower pressure on the side of the shield 31.
Claims
1. A tiltable motorcycle (1), Frame (3) and A saddle (4) fixed to the frame (3), At least one drive rear wheel (5) and Left-steering front wheels (7.1) and right-steering front wheels (7.2), A tiltable four-bar linkage device (13) connects the left steering front wheel (7.1) and the right steering front wheel (7.2) to the frame (3), A steering system (9) connected to the left steerable front wheel (7.1) and the right steerable front wheel (7.2), With respect to the forward direction of the motorcycle, the left steering front wheel (7.1), the right steering front wheel (7.2), and the shield (31) positioned behind the four-bar linkage device (13), Equipped with, The shield (31) is provided with a left deflector (35.1) along its left lateral edge (33.1) and a right deflector (35.2) along its right lateral edge (33.2). The left deflector (35.1), together with the shield (31), forms a channel (C1) for transporting air from the front region of the shield (31) toward the left side of the motorcycle (1). The right deflector (35.2), together with the shield (31), forms a channel (C2) for transporting air from the front region of the shield (31) toward the right side of the motorcycle (1). Motorcycle (1).
2. The motorcycle (1) according to claim 1, wherein the channel (C1) for transporting air from the front region of the shield (31) toward the left side of the motorcycle (1) is formed between the shield (31) and the left deflector (35.2), and the channel (C2) for transporting air from the front region of the shield (31) toward the right side of the motorcycle (1) is formed between the shield (31) and the right deflector (35.2).
3. In a plan view, the left deflector (35.1) is at least partially positioned behind the left steering front wheel (7.1) with respect to the forward direction (F) of the motorcycle, and the right deflector (35.2) is at least partially positioned behind the right steering front wheel (7.2) with respect to the forward direction of the motorcycle, the motorcycle (1) according to claim 1 or 2.
4. In a plan view, the left deflector (35.1) is positioned at least partially further rearward than the suspension (17.1) of the left steering front wheel (7.1), and the right deflector (35.2) is positioned at least partially further rearward than the suspension (17.2) of the right steering front wheel (7.2) with respect to the forward direction (F) of the motorcycle, according to any one of claims 1 to 3 (1).
5. In a plan view, the left deflector (35.1) and the right deflector (35.2) are at least partially positioned further rearward with respect to the tiltable four-bar linkage device (13) with respect to the forward direction (F) of the motorcycle, according to any one of claims 1 to 4.
6. In a front view of the motorcycle, the left deflector (35.1) is at least partially positioned behind the left steering front wheel (7.1), and the right deflector (35.2) is at least partially positioned behind the right steering front wheel (7.2), according to any one of claims 1 to 5 (1).
7. The motorcycle (1) according to claim 6, wherein, in a front view of the motorcycle, the left deflector (35.1) is partially visible above the left steering front wheel (7.1), and the right deflector (35.2) is partially visible above the right steering front wheel (7.2).
8. In a side view, the left deflector (35.1) is positioned at least partially further rearward than the suspension (17.1) of the left steering front wheel (7.1), and the right deflector (35.2) is positioned at least partially further rearward than the suspension of the right steering front wheel (7.2) with respect to the forward direction (F) of the motorcycle, according to any one of claims 1 to 7.
9. In a side view, the left deflector (35.1) and the right deflector (35.2) are at least partially positioned further rearward with respect to the tiltable four-bar linkage device (13) with respect to the forward direction (F) of the motorcycle, according to any one of claims 1 to 8.
10. The motorcycle (1) according to any one of claims 1 to 9, wherein each of the left deflector (35.1) and the right deflector (35.2) comprises a molded sheet, the sheet extending from a front edge (37) located in front of the front surface of the shield (31) with respect to the forward direction (F) of the motorcycle to a rear edge (39) located on the side of the motorcycle (1) behind the front surface of the shield (31) with respect to the forward direction (F) of the motorcycle, and each of the deflectors extends at a distance from the respective lateral edges (33.1, 33.2) of the shield (31).
11. The motorcycle (1) according to claim 10, wherein the sheets of the left deflector (35.1) and the right deflector (35.2) are connected to the shield via a spacer (36).
12. The motorcycle (1) according to claim 11, wherein each of the spacers is configured to have an airfoil-shaped cross section extending along the channel from a leading edge to a trailing edge in order to transport air in the direction of airflow.
13. The motorcycle (1) according to any one of claims 1 to 12, wherein the left deflector (35.1) extends along most of the left lateral edge (33.1) of the shield (31), and the right deflector (35.2) extends along most of the right lateral edge (33.2) of the shield (11).