Motor vehicle

Abstract

A motor vehicle comprises at least: a first transmission for transmitting a steering angle of a handlebar to each steered wheel, which wheels are each structurally supported by an element of a second transmission, which is fixed to the frame, enabling a bouncing movement of the suspension. The first movement mechanism is composed of a shear type mechanism with two elements, and one element is integrated with a main shaft of a wheel. The original characteristic is beneficial for managing the suspension sinking effect caused by ground braking force; it is also helpful to manage different dragging distance changes caused by additional displacement of the rotation axis of the wheel (the additional displacement overlaps with the displacement caused by the suspension movement mechanism), and also helpful to manage different transmission ratios between the column rotation angle of the handlebar operated along the axis and the wheel steering angle measured along the steering axis. The steering angle is measured on an element of an integrated main shaft, rather than downstream of a transmission scissor movement mechanism, and the main shaft contains a wheel rotating shaft.

Description

[0001] Citation of Related Patent Applications

[0002] This application claims priority to Italian Patent Application No. 102024000000300, filed on January 9, 2024, the content of which is incorporated herein by reference. Technical Field

[0003] The present invention relates to the field of straddle motor vehicles having two, three or four wheels (which may be tilting wheels), such vehicles being capable of performing a tilting movement about a median plane extending longitudinally along their length, wherein the steering transmission between the handlebars and at least one wheel is adapted to withstand bounce forces by means of at least one two-element scissor system. Background Art

[0004] In the most common front-end systems for single-steering-wheel motor vehicles, a component fixed to the frame along the steering axis performs both the steering and suspension functions, which the rider can control and rotate via the handlebars; this is the case for both ordinary telescopic forks and Earles or Girder suspensions, the latter two devices not using telescopic components but instead employing a kinematic mechanism with a swing arm that is connected to the frame via the steering axis.

[0005] There are also other very common solutions that distinguish between a first steering axis and a second steering axis on the frame, the first steering axis being the axis about which the handlebars rotate and the second steering axis determining the steering of the wheel and being located in the unsprung mass part of the suspension, which constantly changes its position relative to the axis on the frame during the bounce. In the second group of solutions, a kinematic mechanism is required to effectively transmit the steering movement between the two axes in order to ensure a constant and uniform rotational relationship as much as possible between the handlebars and the wheel and to avoid the wheel from losing steering control due to the bounce of the suspension (a phenomenon commonly referred to as "kickback steering") or the tilting of the vehicle (a phenomenon commonly referred to as "roll steering") when the handlebars are stationary.

[0006] The complexity of such a steering kinematic mechanism depends on the mechanism that guides the bounce and / or roll of the wheels, which, like in the case of the Bimota Tesi, can consist of a transmission push rod with spherical joints, or can use telescopic universal joints as in the Parker US4526249A1 patent, or can integrate the universal joint into a scissor system as in the Doveri IT101993900296913 patent, or can even be a simple two-element scissor system. If it is a two-element scissor system, the two elements can be connected to each other through spherical joints and connected to the frame and the steering shaft on the wheel through two cylindrical hinges parallel to each other, with the steering shaft and the hinges being orthogonal, as shown in the solution of the Hossack GB2207645A patent. The two elements can also be connected through three hinges parallel to each other and orthogonal to the steering shaft, as shown in the specific case of the Cagiva company's IT101992900233465 patent, but in this case the two steering shafts coincide and slide relative to each other under the guidance of a non-steering telescopic group parallel to the shaft. Summary of the Invention

[0007] The present invention aims to provide a motor vehicle without the said drawbacks and which is simple and economical to manufacture.

[0008] The present invention provides a motor vehicle according to the appended claims.

[0009] In particular, it is pointed out that the present invention proposes to overcome the limitations in the kinematic mechanism solution adopted, which transfers the steering between the steering shafts on the frame to the shaft on the unsprung mass of the suspension, thereby reducing its complexity and thus its weight and cost, and also providing new parameters for the designer to improve the vehicle dynamics.

[0010] The new solution requires the use of a two-element scissor kinematic mechanism, characterized in that one of the elements (preferably the element not connected to the steering axis of the handlebars) integrates the wheel axle, and the wheel axle includes the rotation axis of the wheel and the fixed part of the braking assembly: the brake shoes in a drum brake or the more common calipers in a disc brake. Based on this characteristic, the reaction force of the braking torque is released to the scissor kinematic mechanism, rather than on the wheel suspension support system. Therefore, through the position setting of its two elements, the influence of the braking force itself on the suspension movement can be determined. As is well known, the braking force generated at the contact point between the tire and the ground and opposite to the movement direction of the motor vehicle can be easily decomposed into two components. The first component points to the instantaneous rotation center of the vehicle, and the second component is orthogonal to the first component. Since there is a torque due to the lever arm relative to the instantaneous rotation center, it can interact with the suspension movement to cancel or stimulate the latter movement. The first case is usually an "antidive" suspension, and the second case is a "prodive" suspension.

[0011] As is well known, telescopic forks have a "help sinking" characteristic. As the suspension sinks during braking, the inclination of the telescopic link relative to the ground increases, and this behavior of the telescopic fork is significantly weakened, making the wheel trajectory increasingly tend to be vertical; in the extreme case of being completely vertical, the instantaneous rotation center of the contact point between the tire subjected to the braking force and the ground will become infinitely far away, and the influence of the braking force on the suspension movement will become zero.

[0012] It is hereby emphasized that in the known case of using a transmission device with a scissor mechanism, the positions of the two elements constituting the mechanism have no influence on the sinking effect of the suspension, because the trajectory of the unsprung mass including the wheel only depends on the movement mechanism of the suspension itself; while in the present invention, the wheel trajectory is comprehensively determined by the suspension movement mechanism and the scissor movement mechanism for transmitting steering, so the present invention also affects the scrub radius, that is, the distance between the intersection point of the wheel steering axis and the ground and the contact point between the tire and the ground.

[0013] In fact, through the present invention, the scissor steering transmission device can not only control the anti-sinking effect of the vehicle suspension during braking, but also affect the change of the scrub radius.

[0014] If the scissor movement mechanism is well manufactured, it can transmit the steering movement between two relatively moving axes. Even if the transmission ratio during rotation is not uniform or even, with the present invention, the transmission symmetry between turning the handlebar to the right and to the left can be maintained (exactly the same as that of a universal transmission device), because the main shaft is integrated into one of the two elements of the scissor mechanism, and the movement chain is shorter, so the transmission ratio is changed accordingly.

[0015] In terms of structure, the scissor mechanism of the present invention can have various configurations, which are different in the type and position of the hinge and the combination method of the suspension movement mechanism connecting the unsprung mass to the vehicle frame.

[0016] Unless the steering shafts to be connected always coincide because they are guided by a linear trajectory mechanism, such as the telescopic coupling of an aircraft landing gear, the aforementioned Cagiva patent IT101992900233465 or the similar patent application WO1997026178A1 of Lefas, or the steering shafts remain linear in the working area like the Watt, Roberts and Tchebytcheff movement mechanisms (in this case, all hinges can be cylindrical, parallel to each other and orthogonal to the steering shafts), usually only two cylindrical hinges with the said characteristics are used, and a spherical hinge is added, but obviously there is a major limitation, that is, its center cannot be located on one of the two steering shafts, otherwise rotation cannot be transmitted.

[0017] In a reasonable (and also the most commonly used) system, it is possible to avoid having the center of the sphere located on one of the two steering axes, and the spherical joint is placed between the two elements of the scissor mechanism. Therefore, the present invention is special because no main shaft is integrated into one of the two scissor elements between the lower cylindrical hinge of the scissor mechanism and the steering axis, so the lower hinge and the steering axis are close to each other.

[0018] The following situations may occur therefrom:

[0019] - The axis of the lower hinge of the scissor mechanism intersects perpendicularly with the steering axis on the unsprung mass; in this case, the two hinges correspond to an ordinary universal joint and can also be physically replaced by the said commercial joint.

[0020] - Similar to the previous situation, the two hinges are still orthogonal, but their order is reversed, that is, the steering axis is on the main shaft, and the swing axis of the scissor mechanism is on the lever arm. This is an important situation worthy of attention because in the previous case, the driving arm rotates upward, and its front end includes a sunken steering axis, while the lever arm moves the steering axis away from the vertical direction, thereby increasing the trail during the deceleration phase and entering a curve when the opposite effect is desired; however, through the said reversal of the hinges, the steering axis follows the movement of the scissor movement mechanism when it sinks, and this mechanism can be easily configured to correctly reduce the trail, just like a suspension with telescopic forks. It should be noted that reversing the hinges will also cause a change in the steering error, that is, if the suspension sinks and steers at a non-zero handlebar angle, the value will change with the order of the chain, but compared with the said possible situation of reducing the trail during braking and facilitating entering a curve, its impact on vehicle driving is usually negligible.

[0021] - A simpler spherical joint replaces the two orthogonal hinges, which has a greater degree of freedom of movement. But in this case, care must be taken when replacing the spherical hinge placed between the two elements of the scissor mechanism or connecting the hinge to the handlebar column, otherwise the system will be unstable because it may regard the straight line connecting the center of the joint as an (unwanted) second steering axis. Note that this configuration has a spherical hinge on the wheel steering axis of the suspension arm, which can only be achieved by the present invention, rather than only using the scissor system in the known configuration. For the reasons stated above, the sphere cannot transmit rotation, but it does not prevent the movement mechanism connected upstream of it from rotating. The movement mechanism (only existing in the present invention) includes the main shaft and the wheel, that is, the element for steering the vehicle to turn.

[0022] There are two other sub - situations in the latter configuration containing the sphere:

[0023] 1) If the center of the sphere always remains on the axis of rotation of the handlebar, the position of the sphere actually has no influence on the steering movement mechanism, and the handlebar axis coincides with the wheel steering axis; in this case, the movement mechanism connecting the unsprung mass to the frame has a linear trajectory, and this can be achieved by the telescopic group of the Cagiva and Lefas patents or a more complex system that utilizes the Watt, Roberts, and Tchebytceff kinematic structures and has at least one linear trajectory within the working area.

[0024] 2) Conversely, if the center of the sphere is not on the axis of the handlebar (similarly when driving the arm, excluding at most the two torques where the circular trajectory of the force arm intersects the handlebar axis), there is a certain offset of the center of the sphere relative to the axis of rotation of the handlebar, and this offset generates an additional camber angle in the middle plane of the wheel during steering. Depending on the geometry of the scissor drive, this camber angle may or may not be consistent with the roll angle generated by the curve. The said camber angle can be reduced or eliminated, so that the scissor mechanism of the present invention is equivalent to other more complex drive systems that do not introduce a camber angle, but this feature does not necessarily have a negative impact on driving the vehicle. In fact, in the case of the same wheel steering angle, the annular profile of the tire can ensure that the camber angle generates an additional steering effect on the vehicle. Therefore, if the camber generated by the system is consistent with the steering applied by the driver, the effects will be superimposed and the responsiveness of the vehicle will be enhanced. Whether through the camber of the wheel or the lateral camber, the contact point of the tire on the ground can be moved, because the camber occurs around the center of the sphere, and the center of the sphere is at zero distance from the ground. For example, during a right turn, the contact point moves a certain amount to the left, and this amount is superimposed on the similar displacement caused by the steering angle applied by the driver, increasing the stabilizing torque of the drag distance.

[0025] Finally, it is worth noting that since the angles between the two elements of the scissor movement mechanism and between these elements and the frame change during bouncing, this characteristic can be utilized by inserting a suspension element composed of an elastic element, a damping element, or a combination of both between two components connected by a cylindrical hinge, that is, between the upright and the upper element of the scissor mechanism, between the two elements of the scissor mechanism, and between the upright and the lower element.

[0026] This solution can obviously be used for vehicles equipped with a two-wheel rear end and suspension and roll schemes, and can also be used for vehicles equipped with two steering and rolling front wheels. All the described variants of the invention can be used for such vehicles, but it is best to use the variant with the hinges swapped, because if the roll is achieved by the swing of the longitudinal arm, compared with a two-wheel vehicle, it is more necessary to ensure that the ground angle of the steering axis of each wheel remains unchanged, so as to avoid significant changes in the drag distance between the wheels.

[0027] With this invention, the known dual-element scissor movement mechanism has acquired new functions, capable of controlling the anti-squat effect during braking and influencing the scrub radius, the gear ratio, and even potentially introducing additional camber during steering, allowing designers to adjust more parameters to optimize the vehicle's dynamic performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The following preferred vehicle embodiments will be described in detail and highlight other features and advantages of the present invention. These embodiments are merely examples and are not restrictive, and are accompanied by the following drawings:

[0029] Figure 1 Four possible schemes for the steering shaft to transfer rotation to the wheels are shown, comparing the known scheme with the scheme of the present invention;

[0030] Figure 2 A specific application scenario where the unsprung mass of the suspension is guided by a drive arm is shown, comparing the steering transmission scheme implemented by the dual-element scissor mechanism with the scheme of the present invention;

[0031] Figure 3 A detailed comparison is made of Figure 2 the case where the order of the C” and B hinges is reversed as described therein and a derivative version using spheres to replace the two shafts at a steering angle of zero and 30° to the right;

[0032] Figure 4 A second special case is shown where the trajectory of the unsprung mass is ensured by two non-steering telescopic groups and is thus not completely straight;

[0033] Figure 5 The application of the present invention in various steering systems of the suspension type in Figure 4 is shown;

[0034] Figure 6 The application of the present invention in Figure 5 a motor vehicle is shown, demonstrating how the instantaneous center of rotation of a point on the ground is controlled in displacement by the two elements of the scissor transmission during bouncing;

[0035] Figure 7 The application of the present invention in Figure 5 a vehicle is shown, demonstrating how the shock absorber spring assembly can be positioned between the element of the transmission and the fixed steering point of the strut;

[0036] Figure 8 The application of Figure 2 and Figure 3 the swapped hinge scheme on a motor vehicle with two front wheels is shown;

[0037] Figure 9 The structural details of managing front-end roll and bounce through a horizontal rocker arm and roll lock are shown;

[0038] Figure 10 shows the steering lever in three different functional schemes;

[0039] Figure 11 compares Figure 8 the straight-line steering and 30° steering conditions of the vehicle in;

[0040] Figure 12 shows a three-wheeled motor vehicle with a straight guide rail suspension. Detailed implementation mode

[0041] Embodiments will be described below with reference to the drawings. Those skilled in the art recognize that the described embodiments are only examples of the present invention and are not restrictive.

[0042] According to the accompanying drawings, the present invention relates to a motor vehicle equipped with at least one steering transmission system employing a scissor mechanism. In the present invention, the term "motor vehicle" is a broad term including any internal combustion or electric vehicle having at least one steering wheel.

[0043] In the description and the appended claims, the terms "right" and "left" refer to the right and left sides relative to the driver in the driving position on the vehicle. "Vertical" or "horizontal" respectively denote positions orthogonal or parallel to the ground or the support surface of the vehicle in a stationary and vertical state (i.e., not inclined inwardly about the rolling axis). Unless otherwise stated, "below", "above", "on", "under", "middle" generally refer to the position of the parts or components of the motor vehicle relative to the support plane or the ground of the vertically and stationary (not inclined) motor vehicle. In different figures, similar functions will be denoted by the same numbers for easy understanding of their operation modes.

[0044] Figure 1 There are four possible schemes in, where the column 3 is firmly connected to the handlebar 31 of the motor vehicle ( Figure 1 not shown in), can rotate in the cylindrical groove of the motor vehicle frame 4 around the axis A, and transmit the steering determined by the driver to the steering wheel 9 ( Figure 1 not shown in). In the known configuration, the rotation axis G of the steering wheel is located on the main shaft and is fixedly connected to the element 5 in the figure.

[0045] The main shaft refers to the vehicle element that integrates the wheel pin and steers together with the wheel, but it is not affected by the rotation of the wheel around the pin and is suitable as a non-rotating element of the brake; therefore, it is equivalent to the brake shoe of a drum brake and the caliper of a disc brake. The corresponding rotating element, drum track or brake disc is connected to the wheel.

[0046] The element 5 can in turn rotate about an axis B within a cylindrical groove of an element 6 which forms part of a suspension system of a vehicle, the system being arranged to apply a specific trajectory to the element 5 relative to the vehicle frame 4 during a bounce.

[0047] As is known, in order to transmit rotation between two intersecting axes A and B which move relative to one another, a scissor mechanism with two elements 1 and 2 can be used, the mechanism being provided with three suitable connecting hinges, one in the middle and two on the outside. If the two axes A and B coincide and the movement of B relative to A is only a translation along a common direction as shown in variant "a", then the three hinges connecting the two elements 1 and 2 to one another and to the external elements 3 and 5 are cylindrical, with axes C', C and C" respectively, these axes being parallel to one another and orthogonal to the axes A and B. However, during rotation, as long as they do not coincide, even for a short time, then one of the cylindrical hinges needs to be replaced by a spherical hinge, the only significant limitation being that the centre of the introduced sphere 13 cannot lie on one of the axes A, B at the ends of the transmission, since the sphere cannot transmit rotation about its central axis and the movement mechanism may not operate. Remember that the spherical joint represents a triple constraint in terms of movement, since it constrains three spatial coordinates and allows three free rotations; if the centre of the sphere lies outside the externally applied axis of rotation, then it can transmit rotation by virtue of the movement of its centre, whereas if its centre lies on the applied axis of rotation, without changing the coordinates, it cannot transmit an angle, since this would require an appropriate combination of the three angular freedoms achievable by the sphere and would thus potentially result in free movement. Figure 1 In order to move the spherical hinge as far as possible away from the axes A and B, in all vehicles using this type of transmission arrangement with two cylindrical hinges and one spherical hinge, it is usual for the spherical hinge to be in the middle, as shown in variant "b", where the sphere 13 is inserted between the elements 1 and 2 to replace the cylindrical hinge with axis C'.

[0048]

[0049] Figure 1 It should be noted that in all variants, the respective axes C and C" are orthogonal to the axes A and B, and although this configuration is the most common, these conditions are not essential features for the operation of the variant.

[0050]

[0051] According to the invention, the main axis which includes the axis of rotation G of the wheel is no longer located on the element 5 but on the element 2 (axis G' in the figure), this change making variant "b" only apparently the same as the said variant but in fact having improved functionality, the movement chain from the handlebar axis A to the axis of rotation of the wheel (originally G, now G') being shortened and the rigidity and responsiveness being increased.

[0051] The invention places the axis of rotation of the wheel G' on the element 2, which effectively improves the solution, and the vehicles equipped with the invention behave very differently from those using the known solutions.

[0052] In the first case, the invention allows the order of the articulation of the axes C" and B to be reversed in the sequence of movement from the handlebars 31 to the wheel 9. Since the elements 5 and 6 are still there, their functions are the same as described in the known solution, but now these elements are located after the main axis, the order can be reversed, which completely changes the way the vehicle operates, as will be described later. Figure 2 , Figure 3 and Figure 5 shown.

[0053] In another case, in the special case where the two hinge axes C" and B intersect (as mentioned above, usually they do not intersect), the hinge axis can be replaced by a sphere 130 whose center is coextensive with the intersection of the hinge axes; this approach has advantages in terms of volume, weight and cost, and avoids the use of element 5, since the sphere 130 is directly fixed to the unsprung part of the suspension system through an element formerly named 6, now renamed 6', which allows the spherical joint to perform various free rotations.

[0054] When using a sphere located downstream of the main axis, there are two situations: Figure 1 In the "c" solution, the center of the ball 130 always remains on the rotation input axis A during the bounce and steering process, while in the "d" solution, the center of the ball deviates from this axis at least during a certain part of the suspension sinking process. The solution "c" obtained in the first case can be superimposed with the function of "a", while in the second case, the solution "d" is obtained, in which the version of the scissor-type kinematic mechanism with two cylindrical hinges C, C' and the ball 130 below requires an additional degree of freedom in order to work properly; in order to generate this additional degree of freedom, the preselected system provides for the division of element 1 into two parts, 1a and 1b, which are then connected by a new cylindrical hinge, the axis D of which is orthogonal to the other two cylindrical hinges C, C' and intersects the axis A. With this modification, when the system transmits a rotation between A and B, a rotation is introduced along the D axis between the C and C' cylindrical hinges, which rotation contains two components: one component is superimposed on the steering of the main shaft connected to element 2, and the other component is orthogonal to the steering, usually called the camber angle of the wheel.

[0055] Figure 2 Expanded Figure 1The content of the so-called "b" solution, which is achieved by a scissor mechanism composed of two components, 1 and 2, equipped with two cylindrical hinges C and C", and a spherical hinge 13 in the middle position, is applicable to the following situation: The unsprung part of the suspension includes a wheel 9 with a brake disc 12 and a spindle 7 with a brake caliper 11, which is guided by a drive arm 6 through a shaft pivot E. The drive arm is connected to the frame 4 and is equipped with a shock absorber spring assembly 8.

[0056] Figure 2 Details the differences between the prior art solution "b", the solution "b1" of the present invention, and the solution "b2" with the order of hinges C" and B reversed.

[0057] These solutions are represented in pure side views, where the lateral axis degenerates into a point. Therefore, the names of these axes are marked in the figure, and a line is used to represent their projections on the mid-plane M belonging to the frame 4, which includes the steering axis A of the handlebar and the midpoint of the rotation axis of the rear wheel rim.

[0058] In Figure 2 the solution "b", the spindle 7 includes the rotation axis of the wheel G and the brake caliper 11. It is located downstream of the component 2 of the scissor drive and is released by this component through the shaft C". The braking torque acts around the rotation axis G parallel to the C" axis; the drive arm 6 bears this torque and is fixed to the component 5 (integrating the spindle 7) through the steering axis B orthogonal to the torque. Through this solution, the drive arm 6 also identifies the position of the instantaneous rotation center of the braking wheel set at its rotation pivot E.

[0059] Determining the instantaneous rotation center is crucial because the braking force on the ground can be decomposed into two orthogonal directions. One direction points to the instantaneous rotation center that exerts mechanical stress on the structure, and the other direction is orthogonal to this direction. The suspension is compressed or extended according to the position of this instantaneous rotation center. The situation described in image "b" reproduces the prior art, where the instantaneous rotation center is located at the pivot E of the drive arm 6 on the frame 4, and the resulting angle α (usually called the squat angle) is so large that the suspension may be extended during braking, which is obviously not conducive to driving. Because on the one hand, it makes the suspension feel stiffer during braking, and on the other hand, it increases the camber of the steering axis B relative to the ground and even the trail during the cornering phase, while the suspension should drop like a normal telescopic fork during this phase.

[0060] Image "b1" shows the solution of the present invention, where the spindle 7 is integrated into the lower component 2 (now 2') of the scissor mechanism instead of 5, and 5 actually only serves as a physical connection between the two very close axes C" and B (the trajectory of the C" axis in the projection plane of the figure intersects the B axis, but this is not a feature required by the present invention).

[0061] Thanks to this innovation, the two elements 1 and 2 of the scissors joint can be used as part of a four-bar linkage structure in a pure side view. The elements 5 and 6 that make up this four-bar linkage structure are connected by B (perpendicular to the straight steering plane of the four-bar linkage structure and thus having no influence under this motion condition). The main shaft 7 integrated in element 2' changes the trajectory of the wheel axle G' because it no longer moves together with the drive arm 6 (unless the wheel axle G' happens to be located on the hinge axis C", otherwise its trajectory will not change), but serves as the connecting rod of the four-bar linkage structure. Elements 1 and the assembly composed of elements 6 and 5 act as the cranks of the four-bar linkage structure, with the fulcrums located on the C and E axes respectively. When determining the braking behavior, the instantaneous rotation center of the tire-ground contact point is crucial. It is the center of element 2' to which G' belongs and is located at the intersection between the directions defined by the cranks in the plane of the figure. In particular, it should be noted that the upper direction is determined by the synthesis of the trajectory on the C-axis plane and the center of the sphere 13, and the lower direction is determined by the synthesis of the two trajectories on the E-C" axis plane.

[0062] The intersection point changes its position during suspension depression, and if the lines are parallel instantaneously, this intersection point can even be infinitely far away.

[0063] It is necessary to determine a four-bar linkage structure to control the position of the instantaneous rotation center of the ground contact point during braking, because in this way, the instantaneous rotation center can be moved to achieve the behavior desired by the designer, which is usually similar to that of a common telescopic front fork and represents a substantial improvement in driving dynamics brought by the invention.

[0064] The image on the right side of the figure is called "b2". The only change compared to "b1" is that the hinge C" and B of element 5 are swapped, and element 5 is deformed into 5'. The result is obvious. In the situation shown in figure "b1", the lower cylindrical hinge C" is also parallel to the rotation axis of the wheel G' during steering, but in the "b2" situation, with the swapping of the C" and B hinge order, this situation will not occur again (see Figure 3 ), thus resulting in a steering error, that is, if the suspension sinks during the rotation of the steering gear, the rotation angles of both the wheel and the handlebar will increase ("collision steering"). This effect is also generally accepted and controlled in automobiles, and its impact on driving can be completely offset in the present invention because the caster angle of the steering axis on wheel B can be separated from the drive arm 6, the drag distance during braking is reduced, and entering a curve is as simple as a telescopic fork.

[0065] Simply put, with the invention described in image "b1", the vehicle can control the influence of braking torque on the suspension behavior, and at the same time, by swapping the hinge order of "b2", it can also manage the change of the drag distance, solving multiple important limitations of the prior art.

[0066] Figure 3 A detailed comparison was made Figure 2The case where the C-axis and B-axis hinge orders described in "b1" and "b2" are inverted, and the corresponding "d" versions where the two axes are replaced by spheres are shown. The upper row shows the intersection of the two axes during zero turning, and the lower row shows the intersection with a 30° rightward offset of the turning angle. Figure 3 Only the elements and axes that change position during pure turning are shown. These elements and axes have the suffix "st" in the lower row, indicating that they have undergone a 30° turn of the handlebar 31.

[0067] Image "b1" shows Figure 1 the element 5 pointed out in, which is pivotally connected to the element 2' with the C"-axis as the pivot point. The element 2' includes the function of the main shaft 7 and is pivotally connected to the drive arm 6 with the B-axis as the pivot point. In image "b2", the orders of the hinges C" and B are swapped, and the element 5 is deformed into 5' so as to be connected to the other elements 2' and 6 in the new order: now it is connected to the element 6' rather than 2' along the C"-axis ( Figure 3 its number is not pointed out in, because it is opposite to the situation in the "b1" figure and will not change position during turning!), and there is a direct cylindrical seat like B to connect the element 2'.

[0068] As Figure 1 described, the two axes C" and B can be replaced by a spherical joint 130. In this case, the spherical joint follows the Figure 1 "d" scheme in rather than the "c" scheme, because the center of the spherical joint will move in a circular motion along with the drive arm 6 and is therefore always separated from the steering axis A. Similar to the "d" scheme in Figure 1 , the element 1 is divided into two parts 1a and 1b, which can rotate relative to each other along the axis D and are respectively connected to the element 2 and the element 3 through cylindrical hinges along the C and C' axes.

[0069] The 5' element in the "b2" scheme is replaced by a simple spherical joint, which can generate the additional camber of the steering wheel.

[0070] Figure 4 A vehicle with a specific suspension is shown. The trajectory of the unsprung mass in the suspension is completely straight because the two telescopic groups 14', 14" guiding it are completely similar to the telescopic groups of an ordinary motor vehicle, but these two groups are fixed to the frame 4 and therefore do not turn. In order to turn the wheel 9, there should also be a steering axis in the hub B; only when the telescopic groups are parallel to the steering axis can this axis be superimposed with the A-axis of the steering column 3 controlled by the handlebar; in this case, according to Figure 1 , 2 and the image "a" of 3, the steering axes A and B can be connected to each other through a transmission system equipped with two scissor elements 1 and 2, and the three hinges C, C', C" of this system are parallel to each other.

[0071] As described above, when using three cylindrical hinges C, C', C", the steering shaft A fixed to the handlebar and the steering shaft B moving on the wheel need to always remain coincident. If an installation error, manufacturing tolerance, or elastic deformation causes an offset relative to the theoretical coincidence, the driver may be hindered when turning the handlebar. Therefore, it is better to adopt a scheme where the shafts do not coincide with each other during operation, even if this requirement seems unnecessary.

[0072] Due to structural reasons, the main shaft 7 seems to be split into left and right parts to accommodate the steering pin 5 on the suspension support 6, and the suspension support 6 is fixed to the non-steering telescopic groups 14' and 14". Subsequently, each subgroup can be split to accommodate the brake calipers 11' and 11". When passing through the fixing point of the transverse support 6 with a small size and stressed due to a large torsional load, the caliper braking torque generates a reaction in the telescopic groups 14' and 14". It should be noted that this fixing replicates the fixing method between the wheel axle and the fork legs of an ordinary motor vehicle, but there is a significant difference, that is, this system does not have to bear any torsional load generated by the braking torque, and the braking torque is directly released to the telescopic group that fixes the pliers at this time; therefore, compared with an ordinary motor vehicle, the disadvantage in this regard is obvious.

[0073] In order to make the steering element in the wheel hub 5 as long as possible, this element is set to a diameter length that intersects the rotation axis G of the wheel. The offset, which is usually defined as the distance between the steering axis and the wheel rotation axis, is zeroed. As is well known, the scrub radius is the sum of the effects caused by the caster angle and the offset value, but these two effects are different in nature. Therefore, even if the scrub radius value is the same, as long as the two factors are distributed differently, the dynamic behavior is different: during steering, only the caster angle will cause the front end to lower, as exemplified by the rotating wheels of a shopping cart. Only through the offset can the scrub radius be achieved to prevent the cart from lowering during steering, and the customer needs to exert force to straighten the trajectory by restoring the center of gravity height. It should be reiterated for the above content that Figure 4 the scheme in

[0074] Figure 4 shows a vehicle with the above-mentioned characteristics in side view, isometric view, and exploded view. This vehicle is similar to the vehicle claimed in the patent No. 101992900233465 of Cagiva company. As described above, it corresponds to Figure 1 case "a", so there is no modification introduced by the present invention.

[0075] Figure 5 shows various steering systems of the present invention, which are applied to the vehicle in Figure 4 and depicted in images "b1", "b2", and "d". These systems have Figure 3The features described. Since the various components are symmetric with respect to the median plane M of the frame, the symbols (') and (") are used to denote respectively the components located on the left and right sides of the median plane M.

[0076] In the image "b1", the scissor drive of the main shaft 7' is integrated in the element 2 (which thus becomes 2'), but the main shaft can still be disassembled into the 71' part, which is fixed to the two lower end parts 72' and 72" by the radially mounted calipers 11' and 11". The lower end elements 72' and 72" have circular seats to accommodate the bearings connected to the wheel 9 (not shown in the figure), and these bearings allow the element 2' to swing during the suspension sinking as the scissor drive deforms. The wheel hub 15 can also be split into a right side 15" and a left side 15" to allow the assembly of the lateral support 6, which holds the kingpin 5, and the kingpin represents the steering shaft B that coincides with A.

[0077] The seats on the outside of the wheel hub 15 are used to accommodate more wheel bearings, thus allowing the wheel to rotate while the wheel hub 15 remains stationary, with the steering device inside, and the main shaft 7' can swing freely on the bearings outside the wheel: in fact, the wheel rim rotates through two sets of bearings with different sizes coaxial along the axis G..

[0078] Strictly speaking, since the axes of the telescopic elements 14' and 14" assembled are also parallel to the axes A and B, the axes A and B always coincide. In this case, the cylindrical hinge C' connecting the elements 1 and 2' and integrating the main shaft 7' can remain fixed, but considering that the tilt angle of the telescopic assembly with respect to the steering axis can be adjusted, and tolerances, machining errors, and elastic deformations of the structure may cause changes, it is better to use a spherical joint 13 between the elements 1 and 2', adopting a solution that can also work when A and B do not coincide.

[0079] Compared with Figure 3 the situation in, in this case the shaft hinge C" is coaxial with the wheel axis G", and is made of bearings placed outside the steering wheel hub, so the diameter is very large. The coaxiality ensures the correct operation of the calipers, because during the swing of the main shaft 2' due to the suspension sinking, the calipers will be correctly centered on the braking track, and the wheel trajectory will not change, because the element 2' swings exactly around the wheel axis G', and the wheel axis G' maintains the original straight trajectory caused by the telescopic group 14' and 14".

[0080] However, one fact cannot be ignored. Through the present invention, the braking reaction torque is transferred from the telescopic group 14' and 14" to the scissor drive mechanism with two elements 1 and 2', thus eliminating Figure 4 the adverse phenomenon of the load increase shown, limiting its impact on the suspension, as shown below Figure 6 shown.

[0081] It should be noted that if the Figure 4 The solution is to use a telescopic group 14', 14" that must be parallel to the steering axis A=B, otherwise the transmission system with three parallel cylindrical hinges cannot work. The present invention uses a ball joint 13 to make the telescopic group non-parallel to the steering axis. This feature changes the way the trailing distance changes during the sinking of the suspension. If the inclination of the telescopic group relative to the ground is greater than the A=B axis, the component along the axis will be reduced, and the part of the ground braking force that tends to compress the connecting rod will be reduced.

[0082] exist Figure 5 In image "b2", the hinges C" and B are swapped, so that the steering element in the hub becomes 5' and oscillates with the 7" spindle of element 2' during sinking, resulting in a change in the trail, because now the steering axis B is no longer only affected by the linear movement of the telescopic group (even if they are still parallel to A), but also by the circular movement caused by the oscillation of the corresponding element 2".

[0083] This 7" spindle is different from the 7' one, it is a ready-made 15' and 15" part of the hub, so the spindle sinks and swings using the bearings that also allow the wheel to rotate.

[0084] Hinge C" is obtained by placing bearings in the fork legs 16" and 16", so that now element 6" also swings with the kingpin 5" and the main shaft 7" of element 2"; the bearings now used are reduced in size, which on the one hand reduces the weight of the structure and saves construction, and on the other hand allows C" and C' to be non-coaxial, solving the original space problem (but they are still coaxial in the figure). If this non-coaxiality occurs, the wheel 9 that swings with element 2" will present a complex trajectory, depending on the combination of the said swinging and straight-line trajectory of the telescopic group. It is worth noting that even if C" and G' are not coaxial and the hinges C" and B are reversed, there will be no problem in the operation of the caliper, because they can continue to maintain the correct positioning on the brake track through the wheel bearing or swinging around G'.

[0085] An important difference between "b1" and "b2" is the change in the type of bearing that rotates around the C-axis: in the first case, a large bearing must be used that can follow the wheel revolutions, while in the second case a small bearing can be used in the fork leg and, since the bearing is only allowed to oscillate but not rotate, it can be replaced by a bushing or even a ball joint.

[0086] And in Figure 5In the image "d", the two steering shafts B in the transverse hub C" are combined within the sphere 130 on the steering shaft A of the handlebar, in order to further reduce complexity, weight, and cost. Since the spherical joint 130 is smaller in size than the cylindrical steering hinge with the steering pin 5, the spherical joint can be placed far from the diameter of the hub and even the rotation axis G of the wheel, and significantly improve the dynamics when achieving the same movement offset as the traditional telescopic suspension.

[0087] The telescopic guide rails 14’, 14” parallel to the shaft A of the handlebar ensure a straight trajectory, and the center of the sphere is exactly located on the said shaft. Therefore, the center of the sphere 130 always remains on the axis A of the handlebar during sinking and does not generate an additional camber angle during steering. As in other cases, due to the construction tolerances and elastic deformations of the structure, the center of the sphere may be separated from the steering axis of the handlebar. Although this distance is very small in this case, it may also lead to movement failures of the movement mechanism, hindering the driver from rotating the steering device. Therefore, even when the sphere is located on the steering axis A, the additional cylindrical spherical joint described in Figure 1 can be adopted. The spherical joint consists of two elements 1a and 1b, and the elements can rotate relative to each other around the D axis. However, at this time, the spherical joint does not generate an additional camber angle and only ensures good operation.

[0088] Obviously, if it is desired to position the sphere outside the steering axis A and have a straight trajectory imposed by the telescopic group 14’, 14”, then an additional camber angle will be generated during steering. This camber angle may or may not be consistent with the camber angle caused by the vehicle roll angle, depending on the position of the scissor steering element.

[0089] If they are consistent, the responsiveness of the vehicle will increase.

[0090] In any case, the application of the present invention to the type of suspension claimed in the Cagiva patent significantly improves the performance and introduces additional design parameters, such as the control of the anti-dive effect, the trail, and the camber angle.

[0091] Figure 6 Similar to Figure 2 the situations shown in the images "b1" and "b2", where a four-bar linkage structure is set up with parallel rocker arms and the instantaneous center of rotation is located at infinity. This figure shows how the instantaneous center of rotation of the ground contact point changes during bouncing, and this center is controlled by two elements 1, 2 that bear the braking torque within the scissor linkage.

[0092] This figure shows Figure 5 all three situations, because with the present invention, the caliper always swings together with the lower element of the scissor drive, and then moves the reaction force according to the position of the instantaneous center of rotation. But it is in Figure 5In the cases of "b2" and "d", additional effects (not shown in the figures) occur. At this time, wheel B belongs to the lower element of the steering mechanism, and its steering axis changes the camber angle during bouncing, and the vehicle also changes the scrub radius accordingly.

[0093] Figure 7 Shows another variant allowed by the scissor mechanism, which integrates the suspension.

[0094] Due to the change in the relative angle between the two elements of the transmission, this solution is always applicable between these two elements, and thus also applicable to Figure 2 and Figure 3 the solution of, but in the case where the suspension has telescopic groups 14’ and 14”, it is best to position the shock absorber spring assembly 8 between the scissor transmission and the steering fixed point 31 of the column 3, so as to introduce an unknown progressive nature in the compression curve of the suspension, because the traditional fork tends to become more and more vertical relative to the ground and slightly retreat when sinking.

[0095] By introducing an external shock absorber spring assembly into the connecting rod, the connecting rod will obviously lose the corresponding internal elastic and damping elements and only retain the function of guiding the wheel trajectory.

[0096] The left version has a shock absorber spring group 8 working in the compression state, while the right version includes a spring group working in the traction state. However, in both cases, the geometry of the scissor drive system ensures the changing trend of the length of the shock absorber spring group, so that the required geometric progressive nature can be introduced.

[0097] - Figure 8 Shows Figure 3 the application of the scissor drive system "b2" on a vehicle with double front wheels. Both wheels require a mechanism: the symbol (’) refers to the element located on the left side of plane M, and the symbol (”) refers to the symmetric element on the right side of plane M. If the symbol has been previously used to distinguish axes, then in order to distinguish the axes related to the right wheel and the left wheel, a suffix needs to be added, "sx" represents the left side, and "dx" represents the right side.

[0098] However, compared with the solution "b2" in Figure 3 , the introduced variant is provided with a spherical hinge, which originally existed between elements 1 and 2’ (now, due to the doubling of the motion mechanism, between elements 1’ and 2’, 1” and 2”), between the steering rod 21 and elements 1’ and 1”, and is named 13’ and 13”.

[0099] Figure 1 Regarding the description of the system of, it should be noted that the center of the spherical hinge 13 is not located on axis A, because it will not be able to transmit the steering wheel rotation angle. However, the two front wheels solve this problem because the spheres 13’ and 13” must be placed at a large distance from the steering axis A.

[0100] The distance between the spherical hinges 13’ and 13” depends on the expected type of vehicle steering. If it is equal to the distance between the steering axes B’ and B”, the plane where it is located is orthogonal to the axes B’ and B” and passes through the centers of the spheres 13’ and 13”. In the case where the vehicle is not rolling and is steering straight, a rectangle can be determined, which is composed of two pairs of equal opposite sides: the first pair of opposite sides is determined by the distance between the centers of the hinges 13’ and 13”, and the trajectories of the points B’ and B” on the plane; the second pair of opposite sides is determined by the distance between the hinge center and the corresponding projection on the same-side middle plane M, that is, the distance between the center of the hinge 13’ and the projection point B’, and the distance between the center of the hinge 13” and the projection point B”. When the rectangle deforms during steering, it will maintain the parallelism between the sides, so there is parallel steering, that is, the wheels 9’ and 9” and B’ and B” rotate at the same angle.

[0101] However, this situation will result in each side wheel having its own independent instantaneous rotation center, thus causing relative sliding of the tires on the ground, leading to premature wear of the tires and hindering steering. Nevertheless, this higher grip is utilized in some special vehicles, such as go-karts without a differential, or cars with a serious rear weight bias like the Porsche 911.

[0102] As is well known, it is best to ensure that the two wheels share an instantaneous rotation center with the rear axle, that is, to achieve “kinematic steering”, which can be achieved by means of the well-known Jantaud or Ackerman kinematic mechanism. This is a simple implementation method, which is very close to kinematic steering. The specific method is as follows: Draw two lines J’ and J” on the plane orthogonal to the steering axes B’ and B”, which intersect at the height of the ground contact point of a single rear wheel; if it is a double wheel, it can intersect at the height of the connecting line of the ground contact points of the double rear wheels.

[0103] If the centers of the spheres 13’ and 13’’ are located on the lines J’ and J”, regardless of the distance between the centers and the axes B’ and B” (obviously, the greater this distance, the narrower the rod 21), the expected kinematic steering can be obtained.

[0104] With the help of Figure 8 the kinematic steering shown, when the rod translates, the four-bar linkage formed by the centers of the spheres 13’ and 13” and the trajectories of B’ and B” is no longer a rectangle but a trapezoid, and the wheels will turn at different angles (the inner wheel turns more), and the front end will experience a more complex movement for this, because to compensate for the length difference between the base and the side of the trapezoid (as is well known, a rigid-sided trapezoid cannot deform), other freedoms need to be utilized, especially the freedoms of rotation around the C’sx and C”dx axes. In fact, the rod with the handling kinematic mechanism (to be described later in Figure 10(which is explained in detail below)not only presents a lateral displacement but also a longitudinal displacement, increasing the compensation required but not changing the essence of the object.

[0105] Figure 11 Compares Figure 8 The situation of the front end inside in the case of straight wheels and steering wheels.

[0106] Even when using kinematic steering, when the handlebar is not turned and there are potholes or roll, or when any rotation occurs in the 6' and 6" force arms, the wheels still remain straight and parallel to each other, that is, they will not rotate uncontrollably by the handlebar. On the contrary, when such errors only account for a small part of the angle generated by the handlebar itself and can be ignored, the errors will exist.

[0107] If the present invention is used on a rolling vehicle and each steering axis B" and B" inside the vehicle is connected to the drive arm suspensions 6" and 6", then the order of the hinge C" and B can be swapped. This is crucial because the roll is achieved by the reverse rotation of the drive arms 6' and 6", and these drive arms are connected to the wheels 9' and 9" (see Figure 9 ). Therefore, if the axes B' and B" are directly set on the drive arms 6' and 6", their positions relative to the ground will change significantly, resulting in a very large scrub radius for one side wheel and a very small or even negative value for the other side. By swapping the order, the lengths of the elements 1' and 1" in the scissor drive can be made equal to the lengths of the drive arms 6' and 6", thus projecting a rectangle on the midplane M. At this time, the wheel axles 2' and 2" are connected to the corresponding 5' and 5", so as to ensure that during the wheel movement caused by bouncing, especially rolling, the ground inclination angles of the wheels (i.e., the angles between B' and B" and the ground) always remain unchanged. During the deformation process of these rectangles composed of the elements 4, 1', 2' and 5', 6' and 4, 1", 2" and 5", 6", the axes allowed to deform are E, C"sx and C"dx, C'sx respectively. The C'dx and C on the described three-wheeler are identified by the center connection line of the spheres 13' and 13" on the rod 21.

[0108] It should be noted that for a three-wheeler equipped with a lateral suspension, its internal space is greatly reduced, so it is very easy to set a steering axis B' and B" without lateral offset, which is located on the tire middle plane of the corresponding wheel without adjusting the excessive inclination of the rim. For example, there is such a lateral ground arm on the Piaggio MP3, with a length of 25 mm, which can reduce the driving responsiveness.

[0109] Figure 9 Shows the details of a mechanism that manages the front-end roll and bounce through a horizontal rocker arm and a roll lock.

[0110] Known solutions allow the use of a rocker arm 18 which is pivotally fixed to the frame 4 about an axis F, lies in the median plane M and is substantially orthogonal to the plane formed by the axes S' and S" of the shock absorber groups 8' and 8". However, the layout in this case is also quite unique. The rocker arm assembly is aligned with and located behind the drive arms, thus being located under the vehicle footrest and not occupying the front space of the vehicle, which is different from the common configuration where the rocker arm is vertically placed between the wheels. This configuration can also minimize the track width because there is no space for the suspension system between the wheels, only the drive arms 6' and 6" with the minimum distance between them. The common pivot E of the drive arms 6' and 6" is located on a structure 41 connected to the frame 4, parallel to the axis C". A rotary locking system is installed inside, which can connect the drive arms to each other while keeping them free relative to the frame. The lock can be achieved by a known method, such as a belt brake, a drum brake, a disc brake or even a ratchet, and can be automatically driven by the vehicle control unit when the speed and the camber angle drop below a specific threshold. The driver can decide whether to intervene according to a known strategy.

[0111] Figure 9 The mechanical caliper 19 fixed to the drive arm 6' is clearly shown, and the brake disc sector 20 fixed to the drive arm 6" is also faintly shown.

[0112] Since the drive arms 6' and 6" can be connected together, the entire front end can bounce like a rigid axle. Therefore, the vehicle will only pitch (not roll), which is beneficial to improving comfort. This design improves the roll locks of current models such as Piaggio MP3 and Peugeot on the market. Such locks will lock the movement of the suspension after activation, resulting in neither roll nor pitch.

[0113] In the case of no roll and symmetric bounce, the end axes C" of the two drive arms coincide. If there is only roll, the rotation amplitudes of the drive arms 6' and 6" around the common pivot E are equal but in opposite directions. Therefore, each end will have independent axes C’’sx (left side) and C”dx (right side) respectively, but these axes are always parallel to each other and parallel to E. The rear ends of the drive arms 6' and 6" are equipped with protrusions 61' and 61" for fixing the spherical hinges at the ends of the shock absorbers 8' and 8". These shock absorbers basically keep their length unchanged during movement. At the same time, since the rocker arm connected to the spherical hinge can rotate freely, no significant reaction force will be generated. In the case where the two wheels encounter roadblocks (such as road pillars) or rollover blocks simultaneously due to vehicle load and bounce, the force arms 6' and 6" will rotate upward synchronously, evenly compressing the two shock absorbers 8' and 8", without causing the rocker arm 18 to rotate. Finally, an asymmetric impact will cause the relevant arm to move, and the rocker arm will distribute the load, so that the shock absorbers will shorten equally.

[0114] Figure 10The steering rod 21 shown is the core of the system, enabling the scissor steering drive in the invention to be used at the front end equipped with two bouncing, rolling and steering wheels 9', 9".

[0115] In the previous figures of vehicles equipped with a single front wheel, the C-axis between the element 1 of the scissor linkage and the column 3 rotates around the A-axis; as the most obvious improvement, the spheres 13', 13" at the rear ends of the two previously mentioned elements 1', 1" are directly fixed to the steering column 3. However, this will not enable the transmission of steering, because the lateral distance of the said spheres from the median plane M is very large, and the rotation angle of the handlebar is almost completely converted into longitudinal movement at the fixed points, while the design intention of the movement mechanism is to handle lateral displacement work. Therefore, a lateral steering rod needs to be introduced, which can convert the rotation of the handlebar into the lateral displacement of the end spheres of the elements 1', 1".

[0116] Contrary to what usually happens, the rod must have an original characteristic, that is, it must always be orthogonal to the longitudinal vertical median plane of the vehicle M, even during the steering of the handlebar, when the elements 1', 1" of the scissor drive are independent of each wheel in height. Since the elements 1', 1" are fixed in front of the cylindrical hinge along the C’sx and C’dx axes, the rod must be supported at a preset height to prevent it from falling due to its own weight and driving the elements 1', 1" to fall, greatly increasing the angle of the axis B', B" of each wheel with respect to the ground. This angle is defined as the rake angle, which is positively correlated with the trail. Therefore, if the angle increases, the trail also increases, and the driving stability and roughness also increase. If the steering rod 21 is only suspended on the column 3, the longitudinal height can be ensured, thus avoiding the said problem. However, if the spherical joint between the column and the steering rod allows the steering rod to rotate around a substantially vertical axis, the two spheres at the ends of the elements 1' and 1" can be at different longitudinal heights. This is because the spherical joint acts similarly to Figure 9 the rocker arm described in, which will move with the B" axis when the B' axis undergoes an inclined movement, but in the opposite direction.

[0117] In fact, the present invention endows the steering rod with an original characteristic, that is, it converts the steering of the handlebar around the axis A into a substantially lateral movement, that is, orthogonal to the plane M. Subsequently, depending on the implementation method, this movement can also cause translation in the longitudinal and / or vertical directions, but the said orthogonal characteristic is not lost, so there is no rotation.

[0118] The left figure shows a solution where the steering rod 21 is equipped with a transverse cylindrical coupling that is located on a suitable support 42 connected to the frame 4. Steering occurs because the handlebar forces the rod to move purely transversely through rotation, and the spherical joints 13', 13" equipped at the rod ends are fixed to the elements 1', 1" of the scissor drive, forcing the two wheels to turn along their respective axes B', B".

[0119] There is a known transmission system that can convert the rotation of the handlebar around axis A into the transverse movement of the steering rod 21. This system consists of: a pair of double-ended cylindrical hinge parallel connecting rods 22 and a second element 23, and the second element includes two components 231 and 232 that are connected by a cylindrical hinge on the Q axis to ensure that the P axis is always parallel to the A axis during steering.

[0120] According to the described solution, the braking reaction force is directly absorbed by the frame 4 through the seat of the transverse cylindrical hinge, thus leaving the steering column 3 unloaded.

[0121] The middle figure shows the first variant of this solution, which retains the system that transmits the handlebar angle to the steering rod 21 composed of elements 22, 23, but replaces the transverse cylindrical hinge with a four-bar linkage structure that is fixed to the frame and includes the steering rod 21 itself and two identical and preferably symmetrically mounted connecting rods 43', 43" on both sides of the middle plane M. And all the Pa (front) and PP (rear) axes are parallel to each other and parallel to the P axis of the element 232.

[0122] The load is still borne by the frame 4, so the column 3 is unloaded, but the movement is definitely freer because the sliding friction of the transverse cylindrical coupling (which also has its own potential problems in terms of lubrication) is replaced by the ordinary connecting rods 43', 43" mounted on rolling bearings. The only difference is that now the rod no longer makes a purely transverse movement relative to the middle plane M, but is perpendicular to the middle plane M and moves according to the positions of the connecting rods 43', 43". Due to the slight longitudinal displacement of the steering rod 21, the inclination angles of the B', B" axes will change slightly during steering, but since the rods remain parallel during movement, this change is the same for both wheels.

[0123] The third configuration finally uses a four-bar linkage to achieve pure translational motion. However, at this time, the four-bar linkage is fixed to the column 3 instead of the frame 4. On the one hand, the reaction force during braking will act on the column instead of the frame in the original configuration. On the other hand, this solution is simpler, lighter and more economical in design because in two links of the four-bar linkage, one is directly formed by the extension part 31 of the column 3 and the P axis is located on this extension part, and the other is formed by a column 3” that is the same as but shorter than the column 3. This link is fixed to the frame 4 through a bushing, and the A” axis of the bushing is parallel to A. This configuration also eliminates the complex system in the previous solution, which is composed of the transmission elements 22 and 23 between the column 3 and the rod 21.

[0124] It is best to project the axis of the four-bar linkage onto the middle plane M to achieve the coincidence of A = A” and P = P”. However, this is not a rigid requirement for the design: to ensure the translational motion of the steering rod 21, it is only necessary to ensure that the axes A, A’’, P and P’’ are parallel to each other and at least two by two equidistant: in the figure, the distances between A, A” and P, P” are equal, and the distances between A and P, A” and P” are also equal.

[0125] Regarding the greater load supported by this steering system solution, please remember that if compared with a motor vehicle, it will be found that the bounce force in our example is released to the lower part of the frame through the fulcrums of the drive arms 6’ and 6” and the rocker arm 18. When a single-disk motor vehicle brakes straight ahead, if the flexibility of the components brings a steering torque to the handlebars, then factors such as different road surface frictions will cause the wheels 9’ and 9” to receive asymmetric braking forces, which cannot cause the lateral displacement of the steering rod and cannot generate a torque on the steering device, so that the lateral force arm on the ground is zero. Finally, it should be noted that there are always two columns (3, 3”) on the frame, and a part of the bending load will still be absorbed by the column 3” that is not connected to the handlebars.

[0126] Figure 11 Shows Figure 8 the vehicle in, which is equipped with double columns 3 and 3’, and the handlebars are in the left straight position and the right turn 30° when the roll lock is implemented, so that the middle plane M of the vehicle is orthogonal to the ground. For the convenience of reading, the left wheel is omitted to see clearly the components involved in steering. For the relevant explanations, please refer to Figure 8 、 9 and the description of 10.

[0127] Figure 12 Shows Figure 8 the vehicle, in which the parts related to the suspension and roll lock are modified: the bounce and roll are achieved by appropriately changing the lengths of two non-steering telescopic guide rail groups 141’ and 142’, and these guide rails are symmetric with respect to the middle plane M and functionally replace the drive arms 6’ and 6”.

[0128] Compared with the vehicles shown in Figure 4 , 5 , 6, and 7, the telescopic guide rails have become four to ensure that the movement of each wheel is determined by two cylindrical couplings instead of one, avoiding unnecessary rotation around the axis of the remaining cylindrical coupling. A part of these cylindrical guide rails is fixed to the vehicle frame 4, and the other part on the opposite side is fixed to the elements 5' and 5", which are connected to the elements 2' and 2" as described Figure 8 maintaining the connection because the components inside the wheels have not changed. The only difference is that a fixed point is provided for the rocker arm 24 on the main shafts 2' and 2" through the spherical hinges 26' and 26" located at both ends, and this rocker arm controls the actual compression amount of the spring shock absorber assembly 28.

[0129] These cylindrical hinges 26', 26" allow the rotation related to the steering of the wheels 9', 9" (as Figure 8 described, since the spherical hinges 13', 13" are still located on the axes J', J", it is a kinematic type of steering), and at the same time allow the vehicle to roll (i.e., the inclination of the middle plane M relative to the road surface). Therefore, there are different slides between the telescopic groups 141', 142' related to the wheel 9' and the telescopic groups 141", 142" related to the wheel 9". Moreover, the bounce is symmetric when the vehicle is carrying a large load or when both wheels encounter an obstacle at the same time, and asymmetric when only one wheel encounters an obstacle. The said bounce causes the telescopic groups of the relevant wheels to shorten, and in terms of the movement that the spherical hinges must withstand, this bounce is the same as what happens to the inner wheel on the curve during rolling.

[0130] Obviously, the stroke of the telescopic group must also allow a certain elongation because when the vehicle rolls, the two telescopic groups of the outer wheels must elongate by the same amount as the shortening of the telescopic groups of the inner wheels compared to straight driving, and the initial length values of these telescopic groups are the same, all determined by the load borne by the front suspension before rolling.

[0131] Since the rocker arm 24 moves laterally as the vehicle steers, its length must change because the wheels move apart from each other during kinematic steering. To allow for the said change in length, the spherical hinges 26', 26" at the ends are mounted on the detachable terminals 27', 27" of the rocker arm 24. To ensure that the shock absorber spring group 28 does not change its length during steering, that is, the driver does not need to overcome this change by increasing the load during steering, the upper fixing of the shock absorber 28 must also follow the steering movement; therefore, the upper fixing of the shock absorber spring group 28 is located on the protrusion 32 connected to the column 3.

[0132] The end fixation of the spring damper group 28 is very special because it has to withstand the falling torque generated when the roll locking drum 29 is actuated and also maintain the centering position of the rocker arm 24 between the two detachable spherical hinges 26": at the upper end, the fork of the damper 28 is fixed to the column protrusion 32 through a pure cylindrical coupling orthogonal to the A axis, instead of using a spherical joint or a rubber silent block as in a common damper; at the lower end, to avoid unnecessary rotation, the damper group 28 is connected to the rocker arm 24 through a spherical hinge 30, and the center of the hinge passes through the centers of the two end hinges 26’, 26".

[0133] For the correct operation of the damper 28 and rocker arm 24 assembly, the spherical joint 30 must achieve two freedoms: one is the same rotational freedom as the damper axis S, which enables the rocker arm 24 to maintain the same lateral position as the steering rod 21 during steering, while the body of the damper 28 follows the rotation of the column 3 through the protrusion 32 and the said cylindrical coupling along the U axis; the other is the freedom of the rocker arm to lean inwards to adapt to the roll and bounce along the T axis. These two requirements can be met if the center of the hinge 30 is located at the intersection of the axis S and the axis T.

[0134] However, the spherical hinge 30 also allows a rotation orthogonal to the two aforementioned rotational directions, but for the normal operation of the system, this rotation should not cause additional movement; this condition has been met because the center of the spherical hinge 30 is not only located on the line connecting S and T but also on the line connecting the centers of the other two end hinges 26’, 26”, so the concerned degrees of freedom have actually been solved by the spherical hinge and the detachable elements 27’, 27”, and the function of the spherical hinge 30 is repeated without causing unnecessary additional movement.

[0135] The part 291 of the locking drum 29 will be connected to the rocker arm 24, while the other part 292 is guided by the damper spring group 28 during roll through the rotation of the locking drum along the T axis, and the cylindrical collar coaxial with the S axis serves as a guiding carrier, allowing the damper spring group to rotate internally so as to maintain the rotation along the S axis set by the upper end hinge of the U axis.

Claims

1. A motor vehicle, comprising a frame (4) and a roll front end, wherein the roll front end comprises: - a handlebar (31) connected to a column (3), the column (3) being connected to the frame (4) so as to rotate about a first steering axis (A); - at least one front wheel (9) rotatably mounted about an axis outside a central rotation axis (G) and steerably mounted about an axis outside a second steering axis (B); - a main shaft (7) connected to and angled with respect to the front wheel (9) directly mounted above it; - a non-steering support mechanism connected to the frame (4) and rotatably supporting the main shaft (7) so as to allow the main shaft (7) to rotate and bounce about the second steering axis (B); - a brake for braking the front wheel (9) and provided with a fixing part; - a transmission system for transmitting the rotation angle of the handlebar (31) about the first steering axis (A) to the main shaft (7) so that the front wheel (9) rotates about the second steering axis (B); wherein the transmission system comprises a scissor mechanism formed by an upper element (1), a lower element (2) and three hinges along respective hinge axes (C, C', C"), these axes being parallel to each other and most preferably orthogonal to the first steering axis (A) and the second steering axis (B); characterized in that the lower element (2) of the scissor mechanism integrates the main shaft (7) and the fixing part of the brake.

2. The motor vehicle according to claim 1, wherein the trajectory of the lower element (2) during braking is controlled in cooperation with the upper element (1) and a suspension movement mechanism.

3. The motor vehicle according to claim 1, wherein: one of the three hinges connects the main shaft (7) integrated in the lower element (2) to a kingpin (5); and the kingpin (5) rotates about the second steering axis (B) relative to a support (6) of the suspension.

4. The motor vehicle according to claim 1, wherein: one of the three hinges connects the kingpin (5) to a support (6) of the suspension; and the main shaft (7) integrated in the lower element (2) of the scissor mechanism rotates about the second steering axis (B) relative to the kingpin (5) such that the kingpin (5) and the second steering axis (B) during sinking can change the caster angle relative to the support (6) of the suspension, and thus the motor vehicle can adjust the trail according to the geometry of a four-bar linkage formed by the two elements (1, 2) of the scissor mechanism.

5. The motor vehicle according to claim 1, wherein: the upper element (1) is connected to a steering column (3) by a first cylindrical hinge orthogonal to the first steering axis (A) and subsequently connected to the handlebar (31); and The lower element (2) connects the upper element (1) through a second cylindrical hinge parallel to the first cylindrical hinge and is connected to the non-steering support structure through a spherical hinge (13), and the spherical hinge is held on the first steering axis (A) by the suspension movement mechanism during bouncing.

6. The motor vehicle according to claim 5, wherein: the center of the spherical hinge (13) is located outside the first steering axis (A); and the upper element (1) of the scissor mechanism is divided into two parts (1a, 1b), and these parts can rotate relative to each other around a rotation axis (D) intersecting the first steering axis (A).

7. The motor vehicle according to claim 1, wherein the non-steering support mechanism includes two telescopic assemblies (14', 14") fixed to the vehicle frame (4) and non-steering.

8. The motor vehicle according to claim 7, including a shock absorber spring assembly (8), and the shock absorber spring assembly is located between the upper element (1) of the scissor mechanism and the steering column (3).

9. The motor vehicle according to claim 1, wherein the non-steering support mechanism includes one or more drive arms (6).

10. The motor vehicle according to any one of the preceding claims, wherein: there are two front wheels (9', 9") symmetrically arranged with respect to a longitudinal plane (M) connected to the vehicle frame (4), and this plane is determined by the first steering axis (A) and the midpoint of the rear axle; there are two scissor mechanisms, which support the corresponding front wheels (9', 9"), and are both driven by the handlebar (31) through two spherical hinges (13', 13") arranged at the rear ends of the corresponding upper elements (1', 1"); and a shaft (C) connects the centers of the spherical hinges (13', 13"), and can only be controlled to move by the handlebar (31) and is always orthogonal to the longitudinal plane (M).

11. The motor vehicle according to claim 10, wherein: the suspension bouncing and roll movements are achieved through two drive arms (6', 6"), and the two drive arms are equipped with a common pivot axis (E) on the vehicle frame (4), and the front hinge connection axes (C"dx, C"sx) are parallel to each other and parallel to the pivot axis (E); and the two drive arms (6', 6") are also connected to other elements (5', 5"), and these elements are also connected to the upper elements (2', 2") along the second steering axes (B', B").

12. The motor vehicle according to claim 11, wherein: the suspension bouncing movement and roll movement are achieved through the operation of two hinges with connection axes (C"dx, C"sx), and the latter movement is carried out straight along the axes (W1, W2, W3, W4) of the linear guide rails (141', 142', 141", 142"); The linear guides (141’, 142’, 141”, 142”) consist of telescopic groups equipped with cylindrical couplings, the upper part of the telescopic groups being connected to the vehicle frame (4), while the lower part contains shafts (C”sx, C”dx) for connecting the other elements (5’, 5”), which elements are connected to the upper elements (2’, 2”) along the second steering axes (B’, B”); and The bouncing element originates from a shock absorber spring assembly (28), the upper part of which is connected to the projection (32) of the upright (3) by means of a cylindrical coupling orthogonal to the axis (U) and the first steering axis (A), while the lower part is fixed by means of a spherical hinge (30).

13. The motor vehicle according to claim 12, wherein the spherical hinge (30) lies on two lines: one connecting the axis (S) of the connecting rod of the shock absorber spring assembly (28) to the relative rotation axis (T) between the two parts of the roll locking brake; the other connecting two other sets of spherical hinges (26’, 26”) on the two extendable ends (27’, 27”) of the rocker arm (24), which hinges connect the rocker arm to the upper elements (2’, 2”).

Images