Mechanical coupling devices between vehicles, particularly between trains of motor vehicles

Abstract

A coupling device (10) of a type envisaged between a first vehicle (A) with at least two axles and a second vehicle (B) with at least two axles, with the first vehicle (A) positioned preceding the second vehicle (B), is particularly suitable for a convoy of automated guided vehicles. The coupling device (10) comprises a hinged coupling section (20) associated with the first vehicle (A) and a drawbar section (30) associated with the second vehicle (B), which are rotatably connected to each other via an associated distal section. The drawbar section (30) comprises an arc-shaped guide portion (40) horizontally positioned in front of the second vehicle (B) so as to extend from the right side to the left side of the second vehicle (B), a sliding portion (50) sliding along the arc-shaped guide portion (40), and a telescopic arm (60) integrated into one end of the sliding portion (50) and rotatably connected to the other end of the coupling section (20). The coupling device (10) also advantageously includes a steering assist mechanism (70) suitable for redundancy of the steering member (S) in the second vehicle (B) by setting the steering angle depending on the position of the slider (50) along the arc-shaped guide section (40). The coupling device of the present invention allows the automated guidance system to control the position and trajectory of the vehicles without any substantial exchange of forces through the device. The coupling device of the present invention comes into operation when there is a malfunction in the operation of the automated guidance system, allowing the train of vehicles to be safely stopped.

Description

[Technical field]

[0001] The present invention relates to a mechanical coupling device between two vehicles, in particular between a convoy of automated guided vehicles. [Background technology]

[0002] Recent developments in electronics in the transport sector have made it possible to platoon road vehicles, that is to say to build a train of several vehicles in a line, without being guided by a driver, or at most only the first one, while the others automatically follow the leading one. These vehicles are connected, from the point of view of information exchange, in such a way that they slow down and accelerate simultaneously with the first vehicle, thus maintaining the same distance from each other, and with an appropriate phase delay with respect to the preceding vehicle, so that they move in the same direction, but follow the same trajectory.

[0003] Current electronic technology is mature enough to enable platoons of both road vehicles used for public transportation and commercial vehicles to meet regulatory and safety requirements, but mechanical connectivity between the vehicles in the convoy is necessary.

[0004] Vehicle towing devices have been known for some time, which basically include a hinged connection section associated with a leading vehicle and a drawbar section associated with a trailing vehicle. These two sections each have a proximal part rigidly connected to the respective vehicle and a distal interconnecting part that is rotatable. Such devices are intended to allow towing by transmitting forces. These systems are relatively easy to implement and, thanks to the lack of relative motion (apart from a single uniaxial rotational motion), allow easy association of tubes for fluids and electrical sockets for energy exchange. However, this type of device is not at all suitable to allow an automatic guidance system to manage the guidance of the trailing vehicle, so as to rigidly connect the two vehicles with a single degree of freedom of rotation relative to the vertical axis of the hinged connection between the two sections of the towing device, thereby allowing it to travel exactly the same trajectory as the leading vehicle. Furthermore, in such conventional systems, which provide only one degree of freedom of rotation, if the result of the exchanged forces is positive (the leading vehicle pulls more than the trailing vehicle), a behavior will result which will tend to stabilize the convoy, while if the result is negative, the convoy will tend to swerve, whereby each vehicle will tend to go in the opposite direction relative to the leading vehicle, resulting in breakage of the hook and creating an emergency situation which is crucial for braking functionality.

[0005] Also known are coupling devices in which the drawbar section comprises an elongated arm, the purpose of which is to allow the maintenance of a reduced radius of curvature whilst allowing independent steering between the vehicles. Indeed, when two vehicles are in a curve, due to the contours of the vehicles, the distance between the rear central zone of the leading vehicle and the front central zone of the following vehicle becomes longer.

[0006] Other coupling devices in the known art, for example described in EP 0 982 161, US 5 725 231, US 5 468 007 and GB 2 219 979, include the presence of an arched guide rail, which holds the arm of the drawbar section so that the slide can slide along it and move the point of application of the forces exchanged between the two vehicles. In these, the arched rail is integrated into the leading vehicle and its contour is not designed to determine the specific point of application of the forces exchanged between the vehicles on the trailing vehicle.

[0007] EP 0 765 770 A1 discloses a coupling device useful for coupling a locomotive to a trailer not equipped with a steering member. This document also includes an arched guide rail integrated into the trailing vehicle. In this document, the slide that slides along the rail is a pin to which the arm of the drawbar section is pivotally connected in its middle section, while the end of the arm is hinged at a fixed point on the trailer located forward relative to the axis of the trailer itself.

[0008] Furthermore, the mechanical coupling devices in the known art do not provide a kinematic member that can be coupled to the steering means of the tracking vehicle to control the tracking vehicle or at least influence the positioning of the tracking vehicle. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] European Patent Application Publication No. 0982161 [Patent Document 2] U.S. Pat. No. 5,725,231 [Patent Document 3] U.S. Pat. No. 5,468,007 [Patent Document 4] GB Patent Application Publication No. 2219979 [Patent Document 5] European Patent Application Publication No. 0765770 Summary of the Invention [Problem to be solved by the invention]

[0010] The main goal of the present invention is to propose a mechanical coupling device between two vehicles, which allows complete relative freedom of movement between the two vehicles within a certain safety distance and is particularly suitable for creating a mechanically safe connection for automated guided vehicles.

[0011] Another goal of the invention is to propose a mechanical coupling device between two vehicles suitable for maintaining the mutual distance and creating redundancy in the setting of steering angles imposed by the automatic guidance of a convoy of automated guided vehicles.

[0012] Another goal of the invention is to propose a mechanical coupling device between two vehicles suitable for determining the suppression of relative motion between the two vehicles only when their mutual distance and steering angle deviate beyond certain limits that should be imposed by the automatic guidance system of the convoy. [Means for solving the problem]

[0013] According to one aspect of the invention, the aforementioned goal is achieved by a coupling device according to claim 1.

[0014] In particular, a mechanical coupling device of the type generally envisaged between a first vehicle with at least two axles and a second vehicle with at least two axles and comprising a steering member with the first vehicle positioned prior to the second vehicle comprises a hinged coupling section associated with the first vehicle and a drawbar section associated with the second vehicle, each of which comprises a proximal portion rigidly connected to the respective vehicle and a rotatable distal interconnecting portion.

[0015] According to a particular aspect of the invention, the drawbar section of the device comprises: - an arcuate guidance integrated into the second vehicle, extending horizontally between the right and left sides of the second vehicle, the radius of curvature of said arcuate guidance being such that the centre of said relevant radius of curvature is substantially on the centre line of the rear axle of said second vehicle in the rear region of said second vehicle; a sliding part arranged to slide along the arcuate guide part; a telescopic connecting arm, rigidly connected at one end to said sliding part and rotatably connected at the other end to said linking section, said connecting arm having a maximum length and a minimum length so as to define a maximum distance and a minimum distance, respectively, between the first vehicle and the second vehicle; Equipped with.

[0016] The mechanical coupling device outlined above is particularly well suited for application to convoys of automated guided vehicles because it does not rigidly connect the two vehicles, allowing the automated guidance system to determine the vehicle's speed and trajectory, but at the same time establishing safe constraints between the two vehicles should their behavior deviate beyond certain limits from those ideally imposed by a perfectly functioning automated guidance system.

[0017] Advantageously, the drawbar section comprises a steering assist mechanism associated with said slide and with the steering member of the second vehicle, the steering assist mechanism being adapted to act on the steering member in such a way as to tend to maintain the steering position of the second vehicle as a function of the position of the slide along said guide.

[0018] The steering assist mechanism can influence the steering member of the tracking vehicle depending on the position of the slide, so that if there is an excessive deviation between the ideal steering angle imposed by a perfectly functioning automatic guidance system and the actual steering angle, the steering assist mechanism tends to control the steering member to return to the correct trajectory setting.

[0019] Further advantageous features of the mechanical coupling device according to the invention are set out in the dependent claims.

[0020] These and other aspects and advantages of the invention will be understood from the following description of embodiments of the invention, given as non-exhaustive examples, with the aid of the attached drawings. [Brief description of the drawings]

[0021] [Figure 1A] FIG. 1 is a schematic top view of two vehicles in linear motion joined as a train and mechanically connected by a device according to the invention. [Figure 1B] FIG. 1 is a schematic top view of two vehicles joined as a train and mechanically connected by a device according to the invention, in the steering phase. [Diagram 2] FIG. 2 is a top view of a device according to the invention. [Diagram 3] 3 is a cross-sectional view of the device of FIG. 2 taken along line III-III. [Figure 4] FIG. 4 is a detailed view of FIG. [Diagram 5] 1 is a schematic top view of an embodiment of a device according to the invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] With reference to FIG. 1, the number 10 generally denotes a coupling device, envisaged between a first vehicle A, of the type with two axles, and a second vehicle B, also of the type with two axles. The first vehicle A is placed ahead of the second vehicle B. The vehicles A and B are advantageously part of a convoy including other vehicles placed in succession, the individual vehicles and the whole convoy being guided by an automatic guidance system of a type suitable for enabling the vehicles of the convoy to all move on the same trajectory, while keeping their mutual distances substantially unchanged. The leading vehicle, i.e. the first vehicle A, and the following vehicle, i.e. the second vehicle B, are equipped with their own steering systems S, suitable for steering at least at the relevant front axles (FIG. 5). In particular, in the embodiment shown in FIG. 1, the first and second vehicles A and B have steering front axles and non-steered rear axles.

[0023] 2-4, the coupling device 10 comprises a hinged joint section 20 suitable for stable association with a first vehicle A, and a drawbar section 30 suitable for stable association with a second vehicle B. Each of these two sections 20, 30 has a proximal part rigidly connected to the respective vehicle and a rotatable distal interconnecting part. The distal parts of the two sections 20 and 30 advantageously allow free rotation relative to one another about a vertical axis, and also some degrees of rotational freedom (at least a few degrees) about two mutually perpendicular horizontal rotation axes.

[0024] The tensile bar section 30 is: - an arc-shaped guide 40 integrated into the second vehicle B, extending horizontally between the right and left sides of the second vehicle B, having a radius of curvature and positioned relative to the second vehicle B such that the centre C of the associated radius of curvature lies substantially on the centre line of the rear axle P of the second vehicle B; a sliding part 50 arranged to slide along the arc-shaped guide part 40; a telescopic connecting arm 60, rigidly connected at one end to said sliding part 50 and rotatably connected at the other end to said linking section 20, said connecting arm 60 having a maximum length and a minimum length so as to define, respectively, a maximum distance and a minimum distance between the first vehicle A and the second vehicle B; Equipped with.

[0025] The arcuate guide 40 comprises a container body 41, provided with a central separating bulkhead 42, and a cover 43 defining two overlapping rails 44. The guide 40 further comprises two reinforcing flaps 45, which provide greater bending strength, by means of which the arcuate guide 40 is anchored to the second vehicle B. At both ends of the arcuate guide 40 there are respectively removable side covers 46. Removal of the side covers 46 allows the slide 50 to be assembled on the rails 44, which, once fixed to the container body 41, constitute the stroke end elements for the sliding movement of the slide 50.

[0026] The slide 50 comprises a plate 51 and two supports 52 inserted into slots in the cover 43 and at their ends a freely pivoting pin 53 is attached, received in the rail 44 so as to roll on an associated rolling surface. A boot 54 is associated with the slide 50 between the plate 51 and the cover 43 and is operable on the other side of the plate 51, selectively interacting with the cover 43 so as to establish a stop capable of blocking the slide 50 from sliding along the arcuate guide 40 when the telescopic arm reaches a certain minimum length. The interaction between the boot 54 and the outer surface of the cover 43 is advantageously by friction, but alternatively can be produced by interference, forming the surfaces of the boot 54 and the cover 43 into suitable teeth.

[0027] The telescopic connecting arm 60 comprises a traction hook 61. The traction hook 61 constitutes the distal part of the drawbar section 30, provided at one end of an annular body 62 which constitutes a connection member with the articulating section 20. At the opposite end of the traction hook 61, a flange 63 is present, to which a tubular element 64 is fixed and which is telescopically inserted into a cone-shaped element 65 integrated with the sliding part 50. The tubular element 64 has a shoulder 66 in its longitudinal middle section, which constitutes an abutment element for two compression springs 67, 68. The first compression spring 67 acts between the shoulder 66 and the sliding part 50, thereby constituting an elastic member arranged to oppose the contraction of the telescopic arm 60 with respect to the neutral configuration. The second compression spring 68 acts between the shoulder 66 and the cylindrical-shaped element 65, thereby constituting an elastic member arranged to oppose the extension of the telescopic arm 60 with respect to the neutral configuration. The maximum retraction stroke of the telescopic arm 60 is established by the distance between the tubular element 64 and the shoulder 50, since the outer surface of the plate 51 constitutes a stroke end element for the movement of the tubular element 64 relative to the cylindrically shaped element 65. The shoulder 66 advantageously consists of a fastening ring, removably associated with the tubular element 64. The tubular element 64 and the shoe 54 of the slider 50 are constructed and arranged to block the sliding movement of the slider 50 along the arcuate guide 40 by acting on the shoe 54 when the tubular element 64 reaches the proximal end of the associated stroke, pushing the shoe 54 out and into engagement with the arcuate guide 40. The reinforcing tube 69 is arranged coaxially inside the tubular element 64 and guides the telescopic movement inside the cylindrically shaped element 65.

[0028] The coupling device 10 described above works in the following way: In normal operating conditions of a convoy of automated guided vehicles, the mechanical coupling device 10 is not used for a continuous exchange of forces between the two vehicles, since the automated guidance system is responsible for maintaining the distance between the two successive vehicles and for setting the correct trajectory. The configuration of the coupling device 10 allows the automated guidance system to set the correct trajectory for the following vehicle B, thanks to the connecting arm 60 between the two vehicles A and B being able to slide along the arc-shaped guide section 40. In case of small deviations between the ideal mutual positioning of the two vehicles, which the automated guidance system should impose, and the actual mutual positioning, the forces between the two vehicles are exchanged via the device 10. In these cases, small deviations in the distance between the two vehicles are tolerated by the telescopic arm 60, thanks to the provided elastic member, which allows a progressive increase in the forces exchanged between the two vehicles A and B. Additionally, the contour of the arc-shaped guidance section 40 and the associated connection mode to the frame of the following vehicle B also tracks the movement of the sliding section 50 and therefore of the telescopic arm 60 along the arc-shaped guidance section 40, so that the point of application of the force on the following vehicle is maintained on the centerline of the rear non-steering axis of the same second vehicle B. This characteristic reverses the behavior with respect to conventional systems, where the behavior deviates when the force exchanged between the two vehicles is positive (the leading vehicle pulls more than the following vehicle), while the behavior converges when the result is negative (the leading vehicle is braked more than the following vehicle). In a convoy of automated guided vehicles, deviations in traction can be managed thanks to the active control of the automated guidance itself, since if there is traction, the entire system is assumed to be functioning correctly. Otherwise, if the automated guidance does not work, a comprehensive fault signal is generated that forces the entire convoy to a stop, automatically bringing it to a standstill and bringing negative forces, and favorably converging the vehicle behavior. Furthermore, when the distance between the two vehicles A and B decreases beyond a certain limit, the telescopic arm 60 reaches the end of its stroke and the tubular element 64 drives the shoe portion 54 which blocks the sliding of the sliding portion 50 along the arcuate guide portion 40.

[0029] 5, a particularly advantageous embodiment of the mechanical coupling device according to the invention also envisages a steering assist mechanism 70 associated with the sliding part 50 and with the steering member S of the second vehicle B. The steering assist mechanism 70 is configured to act on the steering member S in such a way as to tend to maintain the steering position of the second vehicle B depending on the position of the sliding part 50 along the arcuate guide 40.

[0030] The steering assist mechanism 70 mechanically connects the position of the sliding part 50 along the guide with the steering angle of the second vehicle B, and its configuration naturally depends on the geometry of the steering system in the second vehicle B. In the embodiment shown in FIG. 5, the steering assist mechanism 70 comprises a telescopic rod 71 for connecting to the sliding part 50, two hub carrier connecting rods 72, 73, an eccentric member 76 to which the hub carrier connecting rods 72, 73 are connected, and an actuation mechanism 75 including a parallelogram mechanism 77 articulated to connect the telescopic rod 71 to the eccentric member 76. The rotation of the telescopic rod 71 following the movement of the sliding part 50 along the arc-shaped guide 40 modifies the position and geometry of the articulated parallelogram mechanism 77, which modifies the position and orientation of the eccentric member 76, which in turn actuates the steering member S of the second vehicle B by pushing or pulling the hub carrier connecting rods 72 and 73. Advantageously, the hub carrier connecting rods 72, 73 have elastic shock absorbers 78 which allow slight deviations between the steering angle imposed by the steering member S and the steering angle imposed by the steering assist mechanism 70 of the mechanical coupling device of the present invention.

[0031] The steering assist mechanism 70 creates a redundant mechanical steering control system for the vehicle's steering member S. The steering assist mechanism 70 exploits the linear proportional relationship that always exists between the angle α between the telescopic arm 60 and the longitudinal axis of the vehicle and the inclination angles β and γ of the wheels relative to the longitudinal axis of the vehicle.

[0032] If a second vehicle B is connected to the train by the device of the invention, the position of the sliding part 50 along the arc-shaped guiding part 40 redundantly determines the steering angle of the wheels also when they form the steering member S of the vehicle. In a situation where the automatic guidance system works properly, this does not create any problems, since the steering member S of the vehicle and the steering assistance mechanism 70 set the same steering angle. The elastic shock absorber 78 of the steering assistance mechanism 70 allows a certain tolerance for deviations between the steering angle set by the steering member S of the vehicle and the steering angle set by the steering assistance mechanism 70. The tolerance becomes necessary for dynamic reasons, which may result in a different behavior of the vehicles forming the train, for example, due to different vehicle conditions (drift of tires, delay in responding to the application of a steering angle, suspension members, different loads, etc.). If this tolerance is exceeded, it means that there is a failure in the automatic guidance system and the train of vehicles must stop. In such conditions, the forces transmitted through the mechanical coupling device are always negative and the convergence tendency imposed by the device of the present invention in such situations results in stabilization of the convoy and thus improved safety in emergency conditions.

[0033] In comparison with what has been shown and described, variations in construction may certainly exist, despite always applying the concept of creating a mechanical coupling device as expressed above. In detail, as already emphasized, the outer shape of the arc-shaped guide 40 and the manner of connecting the arc-shaped guide 40 to the second vehicle B naturally depend on the construction and dimensional characteristics of the second vehicle B itself, and the same applies to the steering assistance mechanism 70, the outer shape of which depends on the outer shape of the steering member S in the second vehicle B.

[0034] The above-mentioned advantages of the described embodiment of the mechanical inter-vehicle coupling device according to the invention, in particular for a convoy of automated guided vehicles, are protected in the presence of further variations and embodiments. Indeed, the described and presented embodiments are merely examples and are not limiting. Thus, the device according to the invention may provide further modifications and variations in the nature of the actual application, while still falling within the scope of protection provided by the following claims.

Claims

1. A coupling device (10) of the type envisaged between a first vehicle (A) with at least two axles and a second vehicle (B) with at least two axles, comprising a steering member (S) with the first vehicle (A) placed in front of the second vehicle (B), Particularly suitable for a train of automated guided vehicles, the train of automated guided vehicles comprises a hinged joint section (20) associated with said first vehicle (A) and a drawbar section (30) associated with said second vehicle (B), each of said sections having a proximal portion rigidly connected to said respective vehicle and a rotatable distal interconnecting portion; The drawbar section (30) an arc-shaped guide (40) integrated into the second vehicle (B), extending horizontally between the right and left sides of the second vehicle (B), the radius of curvature of the arc-shaped guide (40) and the positioning of the arc-shaped guide (40) being such that the centre of the relevant radius of curvature is in the rear region of the second vehicle (B); A sliding portion (50) arranged to slide along the arc-shaped guide portion (40); a telescopic connecting arm (60) rigidly connected at one end to the sliding part (50) and rotatably connected at the other end to the hinged connection section (20), the telescopic connecting arm having a maximum length and a minimum length to define a maximum distance and a minimum distance, respectively, between the first vehicle (A) and the second vehicle (B); The coupling device (10) is characterized in that the second vehicle (B) has a front axle on which the steering member (S) is provided and at least one non-steered rear axle, and the contour of the arc-shaped guiding portion (40) and the relative connection method to the frame of the second vehicle (B) are such that the movement of the sliding portion (50) along the arc-shaped guiding portion (40) and thus the movement of the telescopic connecting arm (60) are tracked so that the point of application of forces on the second vehicle (B) is maintained on the center line of the at least one non-steered rear axle of the second vehicle (B).

2. 2. The coupling device (10) according to claim 1, characterized in that the drawbar section (30) comprises a steering assist mechanism (70) associated with the sliding part (50) and with the steering member (S) of the second vehicle (B), the steering assist mechanism (70) being configured to act on the steering member (S) in such a way as to tend to maintain the steering position of the second vehicle (B) depending on the position of the sliding part (50) along the arcuate guide portion (40).

3. 3. The coupling device (10) according to claim 2, characterized in that the steering assist mechanism (70) comprises a telescopic rod (71) for connecting to the sliding part (50), hub carrier connecting rods (72, 73) connecting the steering assist mechanism (70) to the steering member (S) of the second vehicle (B), and an actuation mechanism (75) kinematically connecting the telescopic rod (71) to the two hub carrier connecting rods (72, 73).

4. 4. The coupling device (10) according to claim 3, characterized in that the actuation mechanism (75) comprises an eccentric member (76) to which the hub carrier connecting rod (72, 73) and an articulated parallelogram mechanism (77) are connected, the parallelogram mechanism (77) connecting the telescopic rod (71) to the eccentric member (76) and thereby performing tracking of the movement of the sliding part (50) along the arcuate guide part (40), the rotation of the telescopic rod (71) modifying the position and profile of the articulated parallelogram mechanism (77), which in turn modifies the position and orientation of the eccentric member (76), which in turn pushes or pulls the hub carrier connecting rod (72, 73) thereby moving the steering member (S) of the second vehicle (B).

5. 2. The coupling device (10) of claim 1, wherein the drawbar section (30) comprises a resilient member (68) arranged to resist extension of the telescoping connecting arm (60) relative to a neutral configuration.

6. The connecting device (10) according to any one of claims 1 to 5, characterized in that the drawbar section (30) comprises a resilient member (67) arranged to oppose the contraction of the telescopic connecting arm (60) towards a neutral configuration.

7. The connecting device (10) according to any one of claims 1 to 6, characterized in that the drawbar section (30) comprises a locking member (54) arranged to prevent sliding of the sliding portion (50) along the arcuate guide portion (40) when the telescopic connecting arm (60) reaches the minimum length.

8. The telescopic connecting arm (60) comprises a towing hook (61) constituting the distal part of the drawbar section (30) provided at one end with a ring body (62) for connection to the hinged connection section (20), and at the opposite end of the towing hook (61) there is a tubular element (64) telescopically inserted in a cylindrical shaped element (65) integrated in the sliding part (50), the tubular element (64) having a shoulder (66) in its longitudinal middle section, the shoulder (66) and the sliding part (50) being connected to each other by a ring body (62) at one end of the drawbar section (30).

8. The coupling device (10) according to claim 1, characterized in that it constitutes abutment elements for a first compression spring (67) acting between the shoulder (66) and the cylindrical shaped element (65) thereby constituting an elastic member arranged against the contraction of the telescopic connecting arm (60) relative to a neutral configuration, and a second compression spring (68) acting between the shoulder (66) and the cylindrical shaped element (65) thereby constituting an elastic member arranged against the extension of the telescopic connecting arm (60) relative to a neutral configuration.

9. The coupling device (10) of claim 8, characterized in that the shoulder (66) consists of a clamping ring removably associated with the tubular element (64).

10. The coupling device (10) of claim 8 when citing claim 7, characterized in that the tubular element (64) and the locking member (54) of the sliding part (50) act on the locking member (54) when the tubular element (64) reaches proximal to the associated stroke end, pushing the locking member (54) out and engaging the arcuate guide portion (40), thereby blocking the sliding movement of the sliding part (50) along the arcuate guide portion (40).

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