The subject of the invention is double pivot joint unit with running gear for road vehicles, which beneficially influences the turning ability and safety of the vehicle in a way that the turning lane is about half of the usual one, the swinging mass in the turn is significantly less, thereby the stability of the vehicle is significantly better, relative to the traditional articulated vehicles.
One of the most important aspects of designing articulated vehicles is the safety of combined vehicle, as well as the related allowable velocity. Particularly, the divided vehicle body is to be protected from jack-knifing, as well as from the less critical tilting and wriggling. The phenomenon can be caused by the steering, braking or the quality of the road (route and unevenness) alike. The effect of these factors increases with the velocity, therefore, restriction are usually introduced for the allowed velocity of such combined vehicles. The extent of counter measures to be taken is significantly influenced by the actual loads of the combined vehicle. In addition to the improvement of driving technique of drivers, the safety can be increased also by improving the construction.
In case of the traditional articulated solution the length of the articulated vehicles can be increased only by improving the turning ability, because diameter and the width of the turning lane are limited. The methods for accomplishing this aim was to provide better steering geometry, and the introduction of steering of the rear axle in association with this.
The patent document HU 172 626 makes known articulated vehicle, particularly motor driven vehicle. According to the solution described in this document the wheel of the trailer is steered by the rocker mechanism connected to the towing vehicle. The rear wheel turns in proportion with the actual turning of the towing vehicle. This solution decreases the turning angle between the towing vehicle and the trailer by improving the turning ability, which is particularly important when the vehicle is started from the side of a sidewalk. This solution is widely used, in which the risk of swinging out still exists, although to a limited extent.
Similar solution makes known by the patent document HU 193 631, where the hinge mechanism controls the turning of the rear wheel with similar results. According to the patent document GB 2 068 860 the rear wheels are steered by a complicated linkage attached to the tractor. According to patent document GB 2 446 631 the double axle trailer is also controller by the tractor similarly to the method used in trucks. In both cases the rear wheels turn in a direction which is opposite to the turn of the front steered wheels, but the swinging out still remains.
A different approach is used in the solution makes known by the patent document HU 182100, which introduces an axle configuration used preferably for articulated vehicles. According to the solution described in this document, the rear member of the vehicle train has a driven non-steered rear axle, as well as a non-driven steered front axle. The front vehicle member has rigid axle. This unconventional configuration makes people uneasy, and therefore it is not very much used, although the turning properties of the vehicle are better than those of the traditional vehicle still in use.
The patent document DE 3232367 makes known a railbus design, which is suitable for travelling in both directions. According to the solution introduced in this document the wheels run free on the middle axle, and the centre of the axle coincides with the vertical axis of the hinge. The planned solution does not provide suitable space for the wheels in the hinge, and the hinge is too big, which gives rise to structural problems.
The patent document DE 3841772 makes known an articulated vehicle which can move in both directions along guided route. In this case the hinge accommodates the middle axle also, as a result of which the internal space of the vehicle can be configured in a more flexible manner. A feeler device is necessary for the steering. The guidance for the experimental vehicle was provided by a beam protruding from the carriageway. A separate bus lane had to be established because of it, however, this cannot be intersected by vehicle traffic. This is particularly problematic at crossings. The bus lane cannot be used for other purposes, for instance for rescuing operations. The steering conditions ensured by the fixing of middle axle limits the length of the vehicle substantially. The drawings in the patent are not to scale, the vehicle cannot provide the desired benefit, and this becomes clear only after preparing the drawings again.
The patent document DE 10 2006 037 588 uses a novel computerized approach for analysing the steering of multiple-axle vehicles. A vehicle with four axles and two hinges is introduced here, all the axles of which had to be steered, but the description uses software solution, and not structural solution. The German industrial sample description DE 202007012413 (U1) introduces a control system, which offers solution for the control of hinge angles, which can be different, of vehicles with two hinges. The design and axle configuration of the vehicle are traditional.
The drawbacks of the solutions known and used according to the state of art includes that the traditional articulated buses used in the urban traffic have extremely wide turning lane, which could not be reduced efficiently by the various known solutions. Because of the traditional axle configuration the stability during turning is acceptable only at low vehicle speed. Specifications for the turning lane necessarily limit the vehicle length, therefore, the carrying capacity of the vehicles cannot be increased.
The aim of developing the solution according to the invention was to improve the turning properties of articulated vehicles, particularly the increasing of turning ability and safety, as well as increasing the capacity of the vehicle.
During the development of the solution according to the invention it was recognised that if we use independent joint unit with double pivot between the primary vehicle members of articulated vehicles, then the vehicle will be able to receive intermediate running gear also, as a result of which the above mentioned problems can be resolved and the vehicle gets more beneficial running and stability properties. This recognition also allows the increase of vehicle length and carrying capacity, if the permitted turning lane is utilized.
The invention is a double pivot joint unit with running gear for road vehicles, which joint unit is located between the front member of the road vehicle and the rear member of the vehicle, and the joint unit has a structure consisting of rocker and linkages for preventing jack-knifing and for ensuring proportional turn, which is connected to the front member of the vehicle and to the rear member of the vehicle with rotating rings. It is characterised by that, the joint unit includes the intermediate axle or the vehicle or its twin axle, or the twin axles of the intermediate joint units, and it has double pivots along the longitudinal axis of the vehicle, and a structure that ensures proportional turn of the vehicle members.
In one preferred embodiment of the joint unit according to the invention the structure of joint unit, that ensures proportional turning, consists of two meshing sectors gears, one of which is integrated with one of the rings of one of the rotating ring, while the other sector ring or both of them are integrated with a respective rocker sector gear, and the rocker sector gears are connected directly with connecting rods, or through pitching joint to the vehicle members.
In another preferred embodiment of the joint unit according to the invention the two rocker sector gears are used in the joint unit, which are connected to the front member of the vehicle and to the rear member of the vehicle with connecting rods by means of hinged joint.
In a further preferred embodiment of the joint unit according to the invention rotating rings are installed in its pivots at identical centres, one ring of which are connected to the joint unit and the other ring of which are connected to the vehicle members, and one of the vehicle member is connected to pitching joint which is capable of rotating around a horizontal axis.
In a further preferred embodiment of the joint unit according to the invention a structure for preventing jack-knifing is installed symmetrically to the longitudinal axis of the vehicle, where hydraulic cylinders are connected through hinged joint to the structure of joint unit and to the rocker sector gear or to the intermediate rocker; and their chambers are interconnected with hydraulic pipes passed through the control unit, and the control unit works on the basis of information collected from the vehicle and commands received from the driver's stand through the control port.
In a further preferred embodiment of the joint unit according to the invention in its structure ensuring proportional articulation the radii of sector gears may be different, and/or the alignment of connecting rods may deviate from the parallel.
In a further preferred embodiment of the joint unit according to the invention hydraulic cylinders located symmetrically to the longitudinal axis of the vehicle combine the two functions of the structure of the joint unit, which ensures proportional articulations and provides protection against jack-knifing, which are connected to the structure of joint unit at one side, and are connected at the other side to the intermediate rockers with hinged joint, while the intermediate rockers are connected to the vehicle members through the connecting rods, and the chambers of the hydraulic cylinders are interconnected with hydraulic pipes, which are passed through control unit and routed properly, and the control unit operates the hydraulic cylinders on the basis of the information received from the vehicle through control port and the commands received from the driver's stand.
In a further preferred embodiment of the joint unit according to the invention the pitching movement of the vehicle is ensured by the pitching joint by means of the flexibly embedded horizontal shaft installed between the consoles and one of rings of the rotating ring of one of the vehicle member; or by means of the flexibly embedded horizontal shaft installed between the console of the vehicle member and pitching joint integrated with one of rings of the rotating ring.
In a further preferred embodiment of the joint unit according to the invention the twin axles of the joint unit are established with axle steering.
In a further preferred embodiment of the joint unit according to the invention more than one, in the given case two joint units are used between the front member of the vehicle and the rear member of the vehicle, which are connected to an intermediate vehicle unit.
The solution according to the invention is furthermore set forth by the enclosed drawings:
The towing force is propagated by a pivot, which is supported in bearings, or by the replacing rotating ring. In case of articulated buses, the axles A and B are on the front member'of the vehicle 100, in the given case on a tractor, and the axle C is in the given case on the trailer. Axle A is always steered, while axles B and C are rigid, or axle B is rigid and axle C is counter steered. Double wheels are to be mounted on the middle axle B because of the loads and the drive, or on the rigid axle C working in pushing mode because of the drive, and this significantly reduces the internal space of the vehicle. In the traditional solutions the articulated part needs a space which has a length equivalent to about the width of the vehicle, and only a portion of it can be utilized, and by standing passengers only.
In order to improve the turning ability, the distance between axle B and pivot of joint 130 should be increased, however, this is limited by the tilting of the vehicle body during turning. On the other hand, the axle C is brought closer to the joint 130 in order to meet the requirement about the turning ability, as a result of which the rear overhang of the vehicle body is increased. For this reason the end of the vehicle body swings out from the traffic lane, which is particularly dangerous when the vehicle departs from the side of a sidewalk. The tilting mass M is rather high during the turning of the vehicle, which affects the stability of the vehicle detrimentally. Yet another problem with the traditional articulated solution is that the turning lanes of the vehicle is too wide with the allowed turning radii.
As can be seen in
The rocker sector gear 7 is attached to the front member 1 of the vehicle with connecting rods 8. The connecting rods 8 are attached to the front member 1 of the vehicle and to the rocker sector gear 7 with the help of the hinged joint 16. The rocker sector gear 7 is connected to the joint unit 3 on the pivot 20. The figure also shows the hydraulic cylinders 15, which are connected as indicated by the figure through the hinged joint 16 to the rocker sector gear 7 and to the joint unit 3. The hydraulic cylinders 15 are connected to the hydraulic pipes 17 through the control unit 18, to which the travel information and commands coming from the vehicle are transferred through the control port 19.
The rear member 2 of the vehicle is connected to the external ring 5k of the rotating ring 5 through the consol 11 by means of the horizontal shaft 12 having a flexible bedding. In this structural configuration the vehicle is divided into the common unit of the front member 1 and the joint unit 3, and to the unit of the rear member 2 of the vehicle. This allows the rotation around horizontal axis Y, the pitching movement of the vehicle, which is necessary because of the unevenness of the road and the terrain conditions.
During travelling or turning of the vehicle the hydraulic cylinders 15 follow the movement of intermediate rocker 9, and their pistons move in opposite directions. The operation of the hydraulic cylinders 15 is controlled by the commands received through the control port 19 using the hydraulic pipes 17 passed through the control unit 18. This has a special importance in preventing jack-knifing, when the sudden and large turn of the various members of the vehicle is to be prevented. The hydraulic cylinders 15 can hinder the movement of the intermediate rocker 9 upon the action of the control, and therefore the respective members of the vehicle cannot rotate relative to each other at the pivot 13. During normal traffic conditions the hydraulic cylinders 15 act as shock absorbers.
Possible preferred embodiments and applications of the solution according to the invention:
During the application of the solution according to the invention the properties of the vehicles are made more advantageous by the running gear unified with the joint unit according to the invention. The joint structure unified with running gear includes pivots 13, which pivots 13 have a distance from each other that allows enough space for the wheels of middle axle B when the vehicle bodies articulate while taking a turn. There is a structure in the joint unit 3, which ensures the proportional turn of front member 1 of the vehicle and the rear member 2 of the vehicles, and at the same time, it prevents the undesirable jack-knifing and the pushing over.
As shown in
As can be seen in
As can be seen in
Axle C may be rigid, but a steered axle C is more preferable. As can be seen in
A potential danger of the joint unit 3 having pivots 13 is that the joint unit 3 and the rear member 2 of the vehicle may travel behind the front member 1 of the vehicle with different articulation because of road unevenness and other effects during turning; or the joint unit 3 and the front member 1 may jack-knife in pushing mode. For this reason it is necessary to ensure the proportional turning of the vehicle bodies on the one hand, and the protection against jack-knifing shall be ensured on the other hand. Proportional articulation means that the same degree of articulation of the desired total articulation occurs at the pivots 13. The articulation of the vehicle members could be different from one another at the pivots 13, but they are always proportional.
In case of a preferred embodiment of the solution according to the invention, the proportional articulation is ensured by the meshing sector gears 6, which are integrated with the rocker structure with sector gear 7, and they are connected with connecting rods 8 to the front member 1 of the vehicle and to the rear member 2 of the vehicle. In order to reduce the deflection of the connecting rod 8, it is possible to use an intermediate rocker 9. The intermediate rocker 9 and the sector gear 7 are joined by the connecting rod 10. The sector gear 7 and the pivots 20 of the intermediate rocker 9 are mechanically attached to the structure of joint unit 3. The mechanical design of the entire articulating system allows its operation even in case of hydraulic failure. Instead of one of the sector gear 7, the sector gear 6 can be integrated with the external rings 4k, 5k of the rotating ring 4,5. The external and internal arcs of the rotating rings can be interchanged, for instance, the sector gear 6 can be connected to the internal arc 4b or to the internal arc 5b of the rotating ring.
Jack-knifing of the vehicle is prevented by the hydraulic cylinders 15, which are connected to the joint unit 3 at one side, and to the rocker sector gear 7 or to the intermediate rocker 9 at the other side. The connection points are hinged joints 16 that allow rotation, which are connected to the joint unit 3, or to the rocker sector gear 7 or to the intermediate rocker 9. The chambers of the hydraulic cylinders 15 are interconnected by hydraulic pipes 17 passed through the control unit 18. The control unit 18 controls the operation of hydraulic cylinders 15 on the basis of the information and commands received from the vehicle and from the driver's stand through control port 19.
In case of the second embodiment of the structure that ensures proportional turning and preventing jack-knifing shown in
During the travel of the articulated vehicle, the axis of the vehicle is broken in vertical plane by the unevenness of the road or when travelling on slope. In case of joint unit having double pivot introduced in
The unevenness of the road also causes a lateral tilting of the vehicle during travelling. Considering the width of the vehicle, this tilting has a minor extent, but a rigid structure cannot absorb the load without damage. The protection is provided mostly by the suspension. With the hydro-pneumatic suspension used for instance in large vehicles, the wheels located opposite to each other can be connected in an efficient manner. In case of the solution according to the invention as shown with the embodiments in
The advantages of the vehicle built with the joint unit according to the invention are as follows as compared to the presently known solutions:
The above properties are present in the vehicle simultaneously. The vehicle described above is fully symmetrical in longitudinal direction, therefore it is suitable to travel in both directions, if two driver stands are established. The twin axles allow higher loads too. The size of the vehicles could be increased further, or the turning ability of long vehicles can be improved, if joint unit 3 with multiple axles is used. These vehicles may travel on closed track also as tram or trolley with special permit.
Relative to the traditional articulated solutions, the tilting mass is much less and has better distribution relative to those of the solution according to the invention, which improves the stability of the vehicle significantly.
1—vehicle front member (towing vehicle)
2—vehicle rear member (trailer)
3—joint unit
4—rotating ring (tractor)
4
b—internal ring (rotating ring of tractor) 4k—external ring (rotating ring of tractor)
5—rotating ring (trailer)
5
b—internal ring (rotating ring of trailer)
5
k—external ring (rotating ring of trailer)
6—sector gear
7—rocker sector gear
8—connecting rod (between the tractor unit and one of the rockers)
9—intermediate rocker
10—connecting rod (between the intermediate rocker and the rocker sector gear)
11—console (trailer or tractor)
12—horizontal shaft (with flexible bedding)
13—pivot (joint unit)
14—pitching joint
15—hydraulic cylinder
16—hinged joint (at the hydraulic cylinders and at linkages)
17—hydraulic pipe (between the hydraulic cylinders)
18—control unit
19—control port (for information and commands)
20—pivot (rockers)
21—intermediate vehicle unit (intermediate trailer)
22—road kerb
100—front member (old type vehicle)
200—rear member (old type vehicle)
130—joint
A—steered front axle
B—intermediate axle
B1, B2, B3, B4—twin axles
C—rear axle
F—rear sweep
M—tilting mass
r—internal radius (of turning lane)
R—external radius (of turning lane)
S—turning lane
Y—horizontal axis (joint)
Number | Date | Country | Kind |
---|---|---|---|
P 11 00607 | Nov 2011 | HU | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/HU2012/000110 | 10/25/2012 | WO | 00 | 5/2/2014 |