MOTOR VEHICLE HAVING A TILTING BLOCK DEVICE AND ASSOCIATED METHODS - Patent application

Abstract

In a leaning saddle-type motor vehicle having a lean block system, a control unit is provided which activates a pre-close movement of the lean block caliper towards an initial blocking position before activating a complete blocking of the lean movement, the initial blocking position being calibratable, so that the lean block operates more quickly.

Description

[Technical field]

[0001] The present invention relates to the field of so-called leaning motor vehicles (hereinafter also referred to as vehicles), i.e. motor vehicles with a leaning movement around a mid-plane extending longitudinally along the vehicle. The embodiments described herein relate to a leaning, i.e. rolling, saddle-type vehicle with at least rear drive wheels and two front steered wheels. [Background technology]

[0002] In the field of motor vehicles, motor vehicles that combine the ease of handling of saddle-type two-wheeled motor vehicles (such as motorcycles and scooters) with the stability of four-wheeled motor vehicles have been provided. Among such vehicles, there are three-wheeled motor vehicles with two front steering wheels and one rear drive wheel, and four-wheeled motor vehicles typically called quad bikes.

[0003] More specifically, the above-mentioned three-wheel motor vehicle is provided with two front wheels that are steered and tilted, i.e. adapted to steer the vehicle controlled by the driver via the handlebars, and adapted to tilt laterally with a tilting motion, which is essentially a rocking motion about an axis oriented in the direction of travel. The three-wheel motor vehicle also includes a rear drive wheel that is mechanically coupled to the engine and has the purpose of providing a drive torque and thus enabling traction. The paired front wheel provides the directional control of the vehicle.

[0004] In addition to steering motion, the pair of front wheels have tilting motion and are connected to the vehicle frame via a suspension that allows spring motion. By using two pair of front wheels, a leaning vehicle has greater stability compared to a motor vehicle with only two wheels, due to the front wheels being double supported on the ground, similar to the support provided by an automobile.

[0005] The front wheels are linked together by a kinematic mechanism, for example by one or two four-bar links connecting the front wheels to the front ends, and tilt and steer substantially synchronously. These motor vehicles are often provided with two independent suspensions for each front steering wheel. Each suspension includes an elastic element (spring) and a viscous element (shock absorber).

[0006] Even though the stability is high, under certain conditions, three-wheel and four-wheel tilting motor vehicles may tip over due to uncontrolled tilting motion. This may occur especially when the motor vehicle is moving at a low speed, stopped or parked. To avoid such inconvenience, three-wheel or four-wheel tilting motor vehicles are usually provided with a tilt block device, or tilt control device, which prevents accidental tip over when the motor vehicle is stationary or moving at a low speed. Three-wheel motor vehicles having tilt block devices or tilt control devices are described, for example, in WO 2017115293, WO 2017115294, WO 2017115295, WO 2017115296, WO 2017115297, WO 2018116210, WO 2018116211, U.S. Pat. No. 7,264,251, and European Patent Application No. 1,561,612.

[0007] The tilt block device has proven to be very useful in increasing driving safety and comfort, however, some aspects can still be improved.

[0008] Typically, the tilt block is manually activated by the driver when the motor vehicle is stationary or has stopped. In some cases, automatic tilt block systems have also been developed, which intervene when the motor vehicle's speed falls below a threshold value close to zero. Summary of the Invention [Problem to be solved by the invention]

[0009] One problem with tilt blocking devices is that they are rather slow to operate; i.e. from the moment the tilt block is activated (manually or automatically) until the moment the tilt movement is actually blocked, a few tenths of a second pass due to the stroke that the blocking caliper must perform. The stroke of the caliper lengthens over time due to wear of the brake pads. The driver therefore runs the risk of losing his balance, since the motor vehicle comes to a complete stop before the tilt movement is effectively stopped. However, it is not possible to over-predict the activation of the tilt block, since blocking the tilt movement at a moment when the motor vehicle is still moving at a significant speed entails a significant risk of tipping over. In fact, blocking the tilt movement when the motor vehicle is still moving can lead to the motor vehicle rolling over, for example if one of the front wheels hits an uneven surface.

[0010] It would therefore be useful to provide a tilt blocking apparatus that overcomes the shortcomings of the prior art devices, and in particular, it would be useful to provide a tilt blocking apparatus that requires a shorter intervention time, i.e., that more quickly blocks tilting movement of a motor vehicle.

[0011] According to one aspect, a leaning saddle-type motor vehicle is provided, including two front steering wheels and at least one tilting four-bar link connecting the front steering wheels to a frame. The motor vehicle also includes a blocking member integral with components of the tilting four-bar link and a caliper adapted to cooperate with the blocking member and block the tilting four-bar link relative to the frame. The caliper is controlled by an actuator, for example but not limited to an electric motor with a gearbox if necessary. Also provided is a control unit operatively connected to the actuator controlling the caliper. The control unit is adapted to control a pre-approach movement of the caliper to the blocking member based on driving parameters of the motor vehicle. The pre-approach movement brings the caliper from a fully open position to a position of initial blocking of the leaning movement relative to the blocking member.

[0012] In this way, if the driving parameters indicate that a tilt block may be needed soon, for example before stopping at a traffic light, the caliper of the tilt block system can be brought closer to the blocking position, allowing the tilt block to be activated more quickly.

[0013] Advantageously, the driving parameter of the motor vehicle is a driving speed of the motor vehicle, and the control unit is adapted to control the pre-approach maneuver when the driving speed is below a minimum threshold value.

[0014] As will be explained in more detail below with reference to the accompanying drawings, in an advantageous embodiment the control unit is adapted to perform a calibration step of the initial block position, which may be performed on request by a user or automatically, for example each time the caliper is controlled to move to the tilt block position or only in conjunction with part of the tilt block control.

[0015] The complete blocking of the tilt can be controlled automatically based on the travel parameters, typically the travel speed for example. In other embodiments, the tilt blocking is controlled manually, which is currently preferred for safety reasons. In either case, the approaching movement of the caliper to the blocking member in the pre-blocking step, where the jaws are placed in the initial blocking position, offers the advantage of an effective blocking of the tilt movement faster than in prior art systems.

[0016] Further advantageous features and embodiments of the motor vehicle are described below and defined in the accompanying claims.

[0017] The invention also relates to a method for managing tilt blocks in a lean saddle-type vehicle of the type mentioned above, the characteristics of various embodiments of which are explained below and defined in the accompanying claims. [Brief description of the drawings]

[0018] The invention will become clearer from the following description and the accompanying drawings which show non-limiting embodiments of the invention. [Figure 1] FIG. 2 is an axonometric view of the motor vehicle with some parts removed. [Diagram 2] FIG. 1 is a front view of the front axle of a motor vehicle, showing the front steering wheels, suspension, and tilt four-bar linkage, with the rear wheels and other components of the motor vehicle removed for clarity. [Diagram 3] FIG. 1 is an axonometric view of a tilt block device. [Figure 4] FIG. 13 illustrates the position of the tilt block caliper. [Diagram 5] 13A-13C show different positions of the tilt block caliper. [Figure 6] 13A-13C show different positions of the tilt block caliper. [Figure 7] FIG. 2 is a block diagram of a method according to the present disclosure. [Figure 8] FIG. 2 is a diagram showing various control variables of a motor vehicle and a tilt block system. [Figure 9] FIG. 2 is a diagram showing various control variables of a motor vehicle and a tilt block system. [Figure 10] 4 is a flow chart summarizing a further method according to the present invention involving calibration of initial block positions; [Figure 11] 4 is a flow chart summarizing a further method according to the present invention involving calibration of initial block positions; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] In the following description and in the accompanying drawings, reference is made to a leaning saddle-type motor vehicle having one rear drive wheel and two front steered wheels, with a single leaning four-bar linkage connecting the two front steered wheels to the frame of the motor vehicle. However, it should be noted that many of the novel aspects described herein can be advantageously applied to other types of leaning saddle-type vehicles, such as motor vehicles having four wheels. Also, the novel features of the tilt block control system can be implemented in a system having a dual leaning four-bar linkage.

[0020] With reference to the accompanying drawings, Fig. 1 is an axonometric view of a motor vehicle 1 according to one embodiment. In Fig. 1 and other figures, arrow U indicates the upward direction, arrow D indicates the downward direction, arrow L and arrow R indicate the leftward and rightward directions, respectively. Also, F indicates the forward direction (traveling direction), and B indicates the reverse direction.

[0021] The motor vehicle 1 includes a frame 3 to which rear drive wheels 5 are connected. The rear drive wheels are coupled to an engine (not shown). Reference numeral 9 denotes a saddle of the motor vehicle 1. In FIG. 1, the panels of the body of the motor vehicle, the engine and its transmission members, and other elements that are not necessary for understanding the present invention are omitted.

[0022] In an alternative embodiment, not shown, the motor vehicle 1 includes two rear drive wheels instead of one.

[0023] With reference to the accompanying drawings, the motor vehicle 1 includes, at the front, a front end portion 11 including a steering section, a pair of front steering wheels, and a mechanism for connecting the front steering wheels and their suspensions to a frame 3. This allows the motor vehicle to perform tilting motion, i.e., rotational motion about a horizontal axis parallel to the direction of travel and the ground, i.e., the support surface of the motor vehicle.

[0024] More specifically, the front axle 11 includes a steering column 13 to which a handlebar 15 is connected, shown diagrammatically by dotted lines. The steering column 13 is rotatably housed in a steering sleeve 14 which is integral with or forms part of the frame 3. The driver transmits steering movements via the steering column 13 to two front steering wheels, more precisely a left front steering wheel 17A and a right front steering wheel 17B. The steering movements are transmitted to the front steering wheels 17A, 17B via a steering rod 16.

[0025] One shock absorbing device is associated with each front steering wheel 17A, 17B. This device typically includes an elastic element and a viscous element. More precisely, reference number 19A denotes a left shock absorbing device associated with the left front steering wheel 17A and reference number 19B denotes a right shock absorbing device associated with the right front steering wheel 17B.

[0026] The front steering wheels 17A, 17B and the associated shock absorbing devices 19A, 19B are connected to the frame 3 in a manner that allows a rotational (steering) movement of the front steering wheels 17A, 17B about respective steering axes, indicated by Xa for the left front steering wheel 17A and by Xb for the right front steering wheel 17B. Furthermore, the front steering wheels 17A, 17B are connected to the frame 3 in a manner that allows the motor vehicle 1 to perform a tilting movement, i.e. a tilting movement about a horizontal axis passing through the support surface of the motor vehicle (indicated by S in FIG. 2), for example when a motorcycle is driven around a bend. The tilting movement is represented diagrammatically by two arrows R in FIG. 2.

[0027] To enable such movement, the front end 11 of the motor vehicle 1 includes an inclined four-bar link 21 which provides a mechanical connection between the front steering wheels 17 A, 17 B and the frame 3 .

[0028] The inclined four-bar link 21 (hereinafter simply referred to as the "four-bar link" 21) includes an upper crossbar 23 and a lower crossbar 25 connected to the frame 3 as described below. The four-bar link 21 also includes a left upright 27A and a right upright 27B hinged to the upper crossbar 23 and the lower crossbar 25, which constitute a rocker of the four-bar link 21. In the illustrated embodiment, the left front steering wheel 17A and the left shock absorbing device 19A are connected to the four-bar link 21 via a left arm 20A rotatably housed in the left upright 27A so as to rotate about the left steering axis Xa. Similarly, the right front steering wheel 17B and the right shock absorbing device 19B are connected to the four-bar link 21 via a right arm 20B rotatably housed in the right upright 27B so as to rotate about the right steering axis Xb.

[0029] The upper crossbar 23 is hinged at the midpoint of its longitudinal extension to a central element of the frame 3 or to an element rigidly connected to the frame 3, for example the steering sleeve 14, or to an element integral therewith. Reference number 29 indicates a middle hinge point of the upper crossbar 23. In fact, the hinge point 29 defines a central hinge axis about which the upper crossbar 23 rotates relative to the frame 3. The central hinge axis lies in the vertical mid-plane of the vehicle and its trajectory coincides with the axis AA in FIG. 2. The hinge axis extends in the direction of the mid-plane and is inclined downwards in the direction of the arrow B opposite to the forward movement direction (arrow F).

[0030] The lower crossbar 25 is hinged to a central element of the frame 3 at the midpoint 36 of its longitudinal extension. In fact, the hinge point 36 defines a central hinge axis about which the lower crossbar 25 rotates relative to the frame 3. The central hinge axis, like the hinge axis of the upper crossbar 23 hinged to the frame 3, lies in the vertical mid-plane of the vehicle. The central hinge axis of the lower crossbar 25, like the central hinge axis of the upper crossbar 23, extends in the direction of the mid-plane and is inclined downwards in the reverse direction (arrow B).

[0031] Under certain conditions of the motor vehicle 1, it is advantageous to prevent the upper crossbar 23 and the lower crossbar 25 from tilting, i.e. rotating, relative to the frame 3. This is the case, for example, when the motor vehicle 1 is stationary or nearly stationary, typically when stopped at traffic lights. By blocking the tilting movement (arrow R, FIG. 2) when the motor vehicle is in a vertical position (i.e. when the tilt angle is equal to zero), the driver can balance himself on the saddle of the motor vehicle 1 without having to place his feet on the ground, or even support the weight of the motor vehicle 1 with his feet on the ground. Conversely, when the motor vehicle 1 is moving, even at moderate speeds, the tilting movement must be free.

[0032] The motor vehicle 1 therefore comprises a tilt block device 51, which is shown in Figure 3 but which has been partially removed for a clearer view in Figures 1 and 2. The tilt block device 51 comprises a block member 53 which is integral with one of the elements or components of the four-bar link 21, i.e. with one of the crossbars 23, 25 or with one of the uprights 27A, 27B. In the embodiment shown, the block member 53 is integral with the lower crossbar 25, i.e. rigidly connected thereto, as shown in particular in Figure 2.

[0033] The blocking device 51 also includes a caliper 55 and an actuator 57 for controlling the opening and closing of the caliper. In the illustrated embodiment, the actuator 57 includes a geared electric motor 59, generally designated by the reference number 59. For clarity of illustration, the actuator 57 has been omitted from Figures 1 and 2 and is only shown in the axonometric view of Figure 3.

[0034] In the embodiment shown, the opening and closing movement of the caliper 55 is controlled via a cable 63 inserted in the sheath 61. One end of the cable 63 is fixed to a control element of the caliper 55, and the other end of the cable 63 is fixed to an element 65 movable with a rotational movement f65 about an actuation axis controlled by a motor 59.

[0035] By rotating the element 65 in a direction pulling the cable 63, the caliper 55 is closed, so that the block member 53 is clamped between two jaws 55A, 55B, which are also shown diagrammatically in Figures 4, 5 and 6. The caliper can be opened by an elastic member (e.g. a compression spring) when the cable 63 is released.

[0036] Figures 4, 5 and 6 show the closing movement of the caliper 55. In Figure 4, the caliper 55 is fully open and does not interfere with the block member 53. In Figure 6, the caliper 55 is closed and grips the block member 53 between two jaws 55A, 55B. Because the caliper 55 is integral with the frame 3 of the motor vehicle 1, when the caliper grips the block member 53, the entire four-bar link 21 is integral with the frame 3 and is not deformed. This prevents, or blocks, tilting movement of the motor vehicle 1.

[0037] FIG. 5 shows an intermediate position of the caliper 55, where the jaws 55A, 55B have completed a portion of the closing stroke but have not yet gripped the blocking member. This position is referred to herein as the "initial blocking position" since it precedes the blocking position (FIG. 6) of the four-bar link 21. The initial blocking position has a unique function in the context of the operation of the tilt blocking device 51, which will be described below. Preferably, in the initial blocking position, there is no mutual contact between the jaws 55A, 55B and the blocking member 53. Furthermore, in a slightly less preferred embodiment than the currently preferred embodiment, in the initial blocking position of FIG. 5, the jaws 55A, 55B (or one of them) may be in contact with the blocking member 53 without exerting sufficient force to block the tilting motion.

[0038] The actuator 57 is associated with a position sensor, such as for example a potentiometer or an encoder. The position sensor is configured to detect the position of the actuator or an element thereof mechanically connected to the jaws 55A, 55B of the caliper 55. FIG. 3 shows two points where the position sensor 70 can be provided. The position sensor 70 can be attached, for example, to the shaft of the motor 59 (position 70a in FIG. 3) and detects the position of the actuator by counting the degrees of rotation of the shaft of the motor 59. In another embodiment, the position sensor is aligned with the movable element 65 (position 70b in FIG. 3) and detects the angular movement of the movable element 65 corresponding to the movement of the cable that actuates the caliper 55. In a further embodiment (not shown), the position sensor is attached to a screw mechanism that transmits the movement from the cable 61 to the jaws 55A, 55B.

[0039] The actuators 57 are connected to a central control unit, indicated diagrammatically with reference numeral 71 in FIG. 3 . The central control unit 71 may be a dedicated control unit or may be the central control unit of the motor vehicle 1. For the purposes of the present disclosure, in addition to being operatively connected to the actuators 57, the control unit 71 is also operatively connected to a position sensor 70 of the caliper 55 and to a sensor for detecting at least one driving parameter of the motor vehicle 1. In the embodiment described herein, the driving parameter is the driving speed of the motor vehicle 1 and the sensor may include a tachometer, indicated diagrammatically with reference numeral 73, adapted to detect the speed of the motor vehicle 1.

[0040] The control unit 71 is also operatively connected to an interaction sensor, indicated diagrammatically with reference numeral 75, for detecting an interaction between the caliper 55 and the block member 53. As used herein, the term "caliper / block member interaction sensor" refers to any instrument, control unit, sensor, group of sensors or group of instruments capable of detecting one or more quantities providing information regarding the physical interaction between the caliper 55, i.e. the jaws 55A, 55B, and the block member 53.

[0041] In the embodiment described herein, the interaction sensor 75 comprises a device adapted to directly or indirectly detect the current absorbed by the electric motor 59 of the actuator 57. As will be explained in more detail below, the current absorbed by the electric motor 59 varies based on the interaction between the jaws 55A, 55B of the caliper 55 and the block member 53. More precisely, the current absorbed increases as the force exchanged between the caliper 55 and the block member 53 increases.

[0042] The tilt block device 51 operates as follows.

[0043] When the motor vehicle is traveling, the caliper 55 of the tilt block device 51 is in the fully open position shown in FIG.

[0044] When the motor vehicle 1 decelerates and the travel speed detected by the tachometer 73 or other suitable sensor falls below the threshold value Vmin, the control unit 71 activates the tilt blocking device 51 to cause a partial closure of the caliper 55 accompanied by a pre-approaching movement of the jaws 55A, 55B of the caliper 55. This pre-approaching movement brings the jaws 55A, 55B from the fully open position (FIG. 4) to the initial blocking position of FIG. 5. In this position, the working faces 551A, 551B of the jaws 55A, 55B of the caliper 55 are preferably at a minimum distance from the opposing faces 531A, 531B of the blocking member 53. In this state, the mutual position of the jaws 55A, 55B and the blocking member 53 is still such that they do not block the tilting movement, i.e. the jaws are not in contact with the blocking member 53 or are in contact without exerting a sufficient blocking force.

[0045] The initial block position is achieved by activating the electric motor 59 of the actuator 57 via the control unit 71 to control the pre-approach stroke of the jaws 55A, 55B to the initial block position of Fig. 5. The position sensor 70 detects the position of the caliper 55, i.e., its jaws 55A, 55B, and transmits that information to the control unit 71. The control unit stops the pre-approach movement when the initial block position is reached.

[0046] The initial block location may be part of the stored information available to the control unit 71 .

[0047] As will be explained in more detail below, in a preferred embodiment of the invention, the initial block position is allowed to change over time to account for changes in clearance due to wear, particularly wear of the brake pads on the jaws 55A, 55B.

[0048] In a practical embodiment, the initial block position may be calibrated every time the tilt block device 51 is actuated, or only occasionally, randomly, or after every N actuations of the tilt block device 51, where N>1. The calibration cycle is described below.

[0049] When the tilt block device 51 reaches the initial blocking position of FIG. 5, various situations can occur. If the motor vehicle speeds up, the control unit 71 actuates the actuator 57 to return the caliper 55 to the fully open position (FIG. 4). If the motor vehicle 1 continues to decelerate and eventually comes to a halt, the tilt block device can be actuated by fully closing the caliper 55 (FIG. 6). The tilt block can be controlled automatically, for example when the road speed of the motor vehicle is close to zero. Preferably, the tilt block is controlled by the driver, for example via a control button provided on the handlebar.

[0050] The tilting movement can be blocked more efficiently by the device described herein, since the caliper 55 has already been moved (automatically, without the need for driver intervention) to the initial blocking position of Fig. 5. The subsequent actuation of the tilting block, when the motor vehicle 1 further decelerates and finally to zero, is significantly faster, since the closing stroke of the jaws 55A, 55B is substantially shorter than that required by the prior art system. In fact, a large part of the closing stroke of the caliper 55 has already been performed in advance, when the speed of the motor vehicle has fallen below the threshold Vmin, but is still higher than the speed that would allow the tilting movement to be completely stopped.

[0051] In some embodiments, this corresponds to a reduction of 20% to 70% of the time required to close the caliper 55 in the tilt block position of Fig. 6 compared to the time required with prior art devices. The increased readiness of the tilt block system increases comfort and safety. In particular, the tilt block can be activated very slowly, practically at no speed, reducing the risk of accidental loss of balance, caused for example by a too late activation of the tilt block, i.e. by a too long time interval (even of the order of one second) between the moment of activation of the tilt block and the moment the tilt movement is actually blocked.

[0052] The timeliness of tilt block actuation provided by the pre-approach stroke of the caliper 55 to the initial block position substantially reduces or eliminates this problem.

[0053] The method described above is summarized in the flow chart of Figure 7, where Vo represents the speed at which tilt motion is blocked.

[0054] By taking into account the clearances between the mechanical members of the blocking device 51, the pre-approach stroke towards the initial blocking position (FIG. 5) can be optimized.

[0055] Indeed, in particular the pads 552A, 552B of the jaws 55A, 55B may be subject to wear and reduce in thickness. The caliper 55 is controlled to an initial block position based on a signal from a position sensor 70. This sensor detects the position of the mechanical elements kinematically constrained to the caliper. A given position of the position sensor 70 corresponds to a variable position of the working surfaces 551A, 551B of the jaws 55A, 55B and thus also a variable distance between the working surfaces 551A, 551B of the jaws and the opposing working surfaces 531A, 531B of the block member 53. This change may be due to wear and / or clearance variations of the various members transmitting the motion from the motor 59 to the caliper or of other members of the tilt block arrangement 51. In some cases, the change may occur due to disassembly and reassembly, work, maintenance, cleaning, repair or as a result of the accumulation of dirt on the members of the tilt block system.

[0056] These variations may lead to a decrease in the efficiency of the system described herein, since due to wear the initial blocking position (FIG. 5) may become less optimal and the distance between the jaws 55A, 55B and the blocking member 53 may be greater than strictly necessary for the correct and safe operation of the mechanism described herein. Also, due to an accidental event, in the initial blocking position detected by the position sensor 70, the jaws 55A, 55B may get too close to the blocking member 53 and interact with the blocking member 53 with a more or less high contact force, even hindering to some extent the free tilting movement of the motor vehicle 1, which is preferably completely free until the blocking is actuated.

[0057] To partially or completely overcome this drawback, an improved embodiment of the device described herein may provide an initial block position calibration step, which may be performed, for example, when the engine of the motor vehicle 1 is started, for example under manual control by the user, before starting driving.

[0058] However, the calibration step may preferably be performed each time the tilt block device 51 is actuated, or randomly in conjunction with some of the actuation steps of the tilt block device 51, or after every N actuations of the tilt block device 51. In general, it is advantageous for the calibration step to be initiated and executed automatically, for example by the control unit 71.

[0059] The calibration step may be performed using an interaction sensor for detecting the interaction between the caliper 55 and the blocking member 53. The interaction sensor may be a sensor that provides a direct interaction signal or may be a sensor that provides an indirect signal of the interaction between the caliper 55 and the blocking member 53.

[0060] In the embodiment described herein, the caliper / block member interaction sensor is a device that detects a quantity that correlates to the current absorbed by the electric motor 59 of the actuator 57. This solution is particularly advantageous as it does not require more components than the electric motor 59 would normally comprise. A current sensor detects the absorbed current and generates a signal for the control unit 71. The control unit can process the current signal, for example by extracting therefrom a function of the current over time. In the embodiment described herein, the control unit 71 calculates the time derivative of the current absorbed by the electric motor 59.

[0061] In another embodiment, the caliper / block member interaction sensor is a force sensor, e.g. a load sensor, which detects the force exchanged between the block member 53 and the caliper 55, e.g. one or both jaws 55A, 55B. The load sensor is, for example, fixed to the block member 53. In another embodiment, a distance sensor is provided. The distance sensor measures the distance between one or both working surfaces 531A, 531B and the respective working surfaces 552A, 552B of the jaws 55A, 55B. The distance sensor can be a capacitive sensor, an optical sensor or another type of sensor.

[0062] Referring again to the drawings, FIG. 8 shows the current C1 absorbed by the electric motor 59 as a function of time when the tilt block is actuated. Curve C2 is the position signal of the position sensor 70 associated with the caliper 55. The current C1 has a pattern that shows a peak at the moment when the electric motor 59 is actuated, corresponding to the starting torque. The current is then approximately constant until the jaws 55A, 55B contact the surface of the block member 53. At this point, the mechanical resistance encountered by the jaws as they move forward until the caliper 55 is completely closed causes an increase in the absorbed current. The moment t1 indicates the moment when the mechanical interaction between the caliper 55 and the block member 53 begins. The curve C2 has an approximately linear pattern from the beginning of the closing stroke (moment t0) to the moment t2 when the closing movement of the caliper 55 ends.

[0063] Figure 8 represents the situation where the tilt block occurs in a single operation, i.e. in a gradual closing movement from the position of Figure 4 to the position of Figure 6, and does not show the situation where the caliper 55 remains in the initial block position (Figure 5). In fact, Figure 8 does not represent the effective execution of a tilt block cycle, but is intended to illustrate the variation of the parameters involved and the methods that can be used to perform the calibration step of the initial block position.

[0064] From FIG. 8 it is clear that approximately half the time taken from activation of the tilt blocking device 51 to the stopping of the caliper is required to initiate the interaction between the caliper 55 and the blocking member 53 .

[0065] The method and apparatus described herein essentially operate to reach the initial block position Cx shown by the curve C2 in a pre-approach step when the driving speed V of the motor vehicle 1 falls below the value Vmin. In this way, the time interval [t1-t0] required to achieve the initial block position elapses before the effective (automatic or manual) activation of the tilt block. When the driver or the automatic activation system activates the tilt block, the time required to achieve the effective block is [t2-t1], which is shorter than [t2-t0]. In fact, in order to avoid excessive wear of the pads 552A, 552B of the jaws 55A, 55B and / or to keep the inclined four-bar link 21 completely free for movement until the moment when the block is actually actuated, the initial block position Cx can differ slightly from the position at which the mechanical contact between the jaws 55A, 55B and the block member 53 begins.

[0066] For the reasons mentioned above, if the initial blocking position (FIG. 5) is defined fixedly as a value on the curve C2, the initial blocking position, i.e. the end of the pre-approach stroke, will increase over time due to wear of the mechanical parts forming the tilt blocking device 51, in particular wear of the caliper pads.

[0067] To avoid this, since a signal indicative of the effective interaction between the caliper 55 and the blocking member 53 is available to the control unit 71, it is possible to calibrate the point Cx each time the tilt block device 51 is operated, or to calibrate it only occasionally when the tilt block device 51 is operated.

[0068] In fact, at each tilt block cycle, the current absorption curve C1, or a function of this curve, can be detected and the control unit 71 can determine (from the curve C2) the actual position of the caliper 55 when the interaction between the caliper 55 and the block member 53 starts. This position can be stored as the initial block position. More precisely and more appropriately, the initial block position is set equal to the position Cx corresponding to the start signal of the interaction between the caliper 55 and the block member 53, corrected by a factor to ensure that at the initial block position the jaws 55A, 55B are not yet in contact with the block member 53. If the position read by the position sensor 70 corresponding to the start of the mutual contact between the caliper 55 and the block member 53 is Cx, the initial block position can be set equal to [Cx-A], where A is, for example, a value appropriately selected to keep a distance of a few tenths of a millimeter between the jaws 55A, 55B and the block member 53.

[0069] Fig. 8 shows that the current signal C1 is characterized by a constant ripple and is not particularly practical for implementing the above mentioned control. For this reason, in the present preferred embodiment, the control unit 71 can calculate the value of the time derivative of the current from the current signal C1 and the derivative function can be used for the calibration of the initial blocking position instead of the current signal. Fig. 9 shows the current derivative (curve C3) and the position signal of the position sensor 70 (curve C2) as a function of time. C4 represents the threshold value of the current derivative, which corresponds to the beginning of contact between the caliper 55 and the blocking member 53. On the curve C2, the point Cx corresponding to the beginning of mutual contact between the caliper 55 and the blocking member 53 and the point [Cx-A], which is assumed to be the initial blocking position, are shown.

[0070] The step of calibrating the initial blocking position therefore makes it possible to determine this position when the tilt blocking operation is performed, so that the tilt blocking device 51 always brings the caliper 55 to an initial blocking position which guarantees a minimum distance between the working surfaces 551A, 551B of the jaws of the caliper 55 and the blocking member 53, consistent with a correct operation of the tilt blocking device 51, when the driving speed V of the motor vehicle 1 falls below a threshold value Vmin. This makes it possible to always minimize the time [t2-t1] required to effectively block the tilt four-bar link 21 when required.

[0071] Fig. 10 summarizes a method for controlling the tilt block, including a calibration step for calibrating the initial block position. In the block diagram of Fig. 10 it is assumed that the detection of the interaction position of the caliper and the blocking member is performed each time the tilt block device 51 is operated, but this is not the only possible solution, as mentioned above.

[0072] Under certain circumstances, the jaws 55A, 55B of the caliper 55 may contact the blocking members before reaching the initial blocking position. This type of situation may be caused, for example, by the accumulation of dirt or debris between the blocking members and the working surfaces 551A, 551B of the pads 552A, 552B of the jaws 55A, 55B. In other cases, this type of abnormality may occur due to incorrect reassembly of the members of the tilting blocking system after a maintenance or cleaning intervention, or for other reasons.

[0073] In a particularly advantageous embodiment, in order to avoid or eliminate this type of situation, a control of the interaction between the caliper 55 and the blocking member 53 is provided in the step of approaching the initial blocking position. Essentially, via the caliper / blocking member interaction sensor 75, a premature interaction between the caliper 55 and the blocking member 53 is detected before or when the initial blocking position is reached. Essentially, in such a case, the interaction sensor 75 indicates to the control unit 71 an interaction between the caliper 55 and the blocking member 53 before or when the initial blocking position is reached. If a premature interaction occurs, the control unit 71 can stop the approaching movement to the initial blocking position and, if necessary, control a small backward movement of the caliper 55. The new position reached by the caliper can be stored as a new initial blocking position.

[0074] The above mentioned checks are combined with those explained with reference to figure 10. The process involving the double checking of the interaction between the caliper 55 and the blocking member 53 is summarised in the flow chart of figure 11.

[0075] Basically, in such a case, a step of calibrating the initial block position is provided, which can be performed before and / or during the approach of the caliper to the pre-stored initial block position or after the caliper 55 has reached the tilted block position. This system makes it possible to correct deviations with respect to the pre-stored initial block position both in case of premature stopping (too far) of the jaws 55A, 55B with respect to the block member 53 and in case of premature contact of the jaws with the block member.

Claims

1. A tilting saddle-type motor vehicle, two front steering wheels and at least one tilt four-bar link connecting the front steering wheels to a frame; A block member integral with the components of the inclined four-bar link; a caliper adapted to cooperate with the blocking member to block the inclined four-bar link relative to the frame; an actuator for controlling the caliper; a control unit operatively connected to the actuator for controlling the caliper; Including, the control unit is adapted to control a pre-opening movement of the caliper towards the blocking member based on a driving parameter of the motor vehicle, the pre-opening movement bringing the caliper from a fully open position to an initial blocking position of a tilting movement relative to the blocking member. Motor vehicle.

2. The motor vehicle of claim 1 , wherein the driving parameter of the motor vehicle is a driving speed of the motor vehicle, and the control unit is adapted to control a pre-approach maneuver when the driving speed is below a minimum threshold value.

3. 3. The motor vehicle according to claim 1 or 2, wherein the control unit is adapted to execute a calibration step of the initial block position when the caliper is brought into an anti-tilt position.

4. an interaction sensor between the caliper and the block member; the interaction sensor is adapted to detect a quantity indicative of an interaction between the caliper and the blocking member; The motor vehicle of any one of claims 1 to 3, wherein the control unit is functionally connected to the interaction sensor and adapted to perform a step of calibrating the initial block position based on an amount indicative of an interaction between the caliper and the block member.

5. 5. The motor vehicle of claim 4, wherein an amount indicative of the interaction between the caliper and the block member is a function of a distance between an action surface of the caliper and the block member.

6. 6. The motor vehicle of claim 4 or 5, wherein the control unit is adapted to store a position of the actuator controlling the caliper detected by a position sensor when a quantity indicative of an interaction between the caliper and the blocking member has a value associated with an initial blocked state of the tilting movement.

7. 7. The motor vehicle according to claim 4, wherein the actuator for controlling the caliper is an electric actuator.

8. 8. The motor vehicle of claim 7, wherein an amount indicative of the interaction between the caliper and the blocking member is a function of the current absorbed by the actuator controlling the caliper.

9. 9. The motor vehicle of claim 8, wherein the quantity indicative of the interaction between the caliper and the blocking member is the time derivative of the current absorbed by the actuator controlling the caliper.

10. 10. The motor vehicle of claim 9, wherein the control unit is adapted to detect the initial blocking position when a derivative of the current absorbed by the actuator controlling the caliper exceeds a threshold value.

11. The motor vehicle according to any one of claims 4 to 6, wherein the interaction sensor between the caliper and the block member includes one of a load sensor adapted to detect a force exchanged between the block member and the caliper, and a sensor to detect proximity between an active surface of the caliper and the block member.

12. 1. A method for controlling blocking of leaning motion of a leaning saddle-type motor vehicle including two front steering wheels and at least one leaning four-bar link connecting the front steering wheels to a frame, a blocking member integral with components of the leaning four-bar link, and a caliper adapted to cooperate with the blocking member and block the leaning four-bar link relative to the frame, comprising: detecting a driving parameter of the motor vehicle; activating an actuator controlling the caliper based on the driving parameters to perform a pre-close movement of the caliper towards the blocking member, bringing the caliper from a fully open position to an initial blocking position for a tilt movement relative to the blocking member; A method comprising:

13. The method of claim 12 , wherein the driving parameter is a driving speed of the motor vehicle, and the pre-approach maneuver is performed if the driving speed is below a minimum threshold.

14. The method according to claim 12 or 13, further comprising a calibration step of calibrating the initial block position when the caliper is brought into an anti-tilt position.

15. The calibration step includes: actuating the caliper to block the tilting motion; detecting a quantity indicative of an interaction between the caliper and the blocking member when the caliper performs a closing motion to clamp the blocking member; storing a position of an actuator as an initial block position based on a quantity indicative of an interaction of the caliper and the block member; Including, The method of claim 14.

16. The method of claim 15 , wherein an amount indicative of the interaction between the caliper and the blocking member is a function of the distance between an action surface of the caliper and the blocking member.

17. 17. The method according to any one of claims 12 to 16, wherein the actuator controlling the caliper is an electric actuator, and the quantity indicative of the interaction between the caliper and the blocking member is a function of the current absorbed by the actuator controlling the caliper.

18. The method of claim 17 , wherein the quantity indicative of the interaction between the caliper and the blocking member is the time derivative of the current absorbed by the actuator controlling the caliper.

19. 20. The method of claim 18, wherein the initial blocking position is the position of the caliper when a derivative of the current absorbed by the actuator controlling the caliper exceeds a threshold value.

20. 17. The method according to any one of claims 12 to 16, wherein the quantity indicative of the interaction between the caliper and the blocking member is one of a force exchanged between the caliper and the blocking member and a distance between an action surface of the caliper and the blocking member.

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