Connecting mechanism ^" that connects two vehicles or vehicle parts and method for producing a link arm for a connecting mechanism

TECHNICAL FItLD

The present invention relates to a connecting mechanism that connects two vehicles or vehicle parts, e.g., an accordion bus. More specifically, a control mechanism consisting of two crossed link arms, each of which is linked at its first end to a first part of the vehicle and at its other end to a second part of the vehicle, together with damping means to control the movement between the front and rear parts of the vehicle.

BACKGRC fUN))

Connecting mechanisms for articulated buses or railroad cars have existed for a long time. A usual connecting mechanism is to have a large bearing between a bus and a trailer, where a first molded connecting plate is arranged in ibe rear par? of Hie bus and another molded connecting plate in the front part of the trailer, are placed between the parts. Such as structure, however, is relatively unstable, since it has only one contact point (bearing), which rotates easily about its own axis. The structure also tends to be heavy and stiff. Instability is another problem, especially when ii is the trailer that drive.; _* the assembly forward, and in order to help this, large damping cylinders and electronic monitoring/control systems are mounted.

US 5,452,912, US 4,421,339, HP 1,245,468, E? 1,126,986, DF 3134301. and FP 1 ,342,594 Bl are examples of various connecting plates.

PURPOSE OF THE INVENTION One goal of tbe present invention is Io provide structure for a connecting mechanism for an articulated bus or railroad car that has a relatively low weight.

Other goals of the inventions arc:

~ to provide a connecting mechanism for articulated buses or railroad cars tbai is relatively strong.

- to provide a connecting mechanism for articulated buses or railroad cars that is relatively inexpensive to produce,

- to provide a connecting mechanism for articulated buses or railroad cars ihaf causes a lower environmental burden during production. - to provide a connecting mechanism for articulated buses or railroad cars that causes a lower environmental burden the work of operating the vehicle.

BR)BP DESCRIPTION OF THF INVENTION

At least one of the above goals is solved by providing a connecting mechanism according to the type described above, where at least one of the link amis has a longihidirsa! cavity with a covering materia] ami fhat it includes a cross-section, preferably half as. large or less, even more preferably one third as large or less. This contributes to making it possible for the connecting mechanism to be made extremely light, with low material consumption and minimal effect on the environment.

Additional reported characteristics:

That each of the link arms includes an upper long profile with a mainly U- shaped cross-section and a lower long profile with a mainly U-shaped cross- section, which upper and lower profiles are arranged with their respective open sides facing each other, so as to from an enclosing cross-section with a longitudinal inner hollow space, with two opposite longitudinal welded joints where the U-profϊles meet. This contributes to the link arms becoming extremely strong, and they can handle high axle pressures and loads. That the set of materials consists of a metallic material, preferably steel, even more preferably stainless steel. - That the set of materials has a thickness in the range 4-20 mm.

Also, a method for producing a link arm for a connecting mechanism, including the steps: a) forming two U-pro files out of a rolled plate, b) placing the two U-profϊles against each other, so that they from a cross- section where the free-standing edges of U-pro files meet one another, c) longitudinal welding, where the edges of the U-pro files meet one another, so that a hollow profile is formed.

DESCRIPTION OP THE- DIAGRAMS

Fig. 1 shows a divided vehicle with a front and a rear part connected with a link mechanism.

Fig. 1 a shows tbe orientation of the x, y, and z axes with respect Io fhe vehicle.

Fig.] c shows the behavior of the connecting mechanism when the vehicle turns. Fig. 2 shows a perspective view of a connecting mechanism.

Fig. 3a, 3b shows the link arms, viewed from the side.

Fig. 4 si io Wb a Sink ami seen from above.

Fig. 5 shows an upper and a lower half with the cross-section on a link arm. Fig. Ci shows the link mechanism seen from above and in maximum final deviation. Fig. 7 shows a process overview for producing a link arm,

I)[ TAHJ D DESC R[PI lOK

Wc shall now describe the connecting mechanism 3, starting from Figs. i -6. A connecting mechanism / connecting plate 3 connects a front vehicle part 1 to a rear vehicle par! 2. The vehicle I, 2 can be, for example, an articulated bus, railroad ear, rail bus, or streetcar. The connecting mechanism permits contact between the front and rear vehicle parts in the vehicle, specifically:

- a rotating contact about the vertical axis (Z)

~ rotation about the longitudinal axis of tbc vehicle ( X)

- rotation about the transverse axis of the vehicle (Yj.

In a vehicle, a transition bridge (not show) is normally used over the connecting mechanism 3 that permits a passenger to pass between the front and rear vehicle parts. /Vn encapsulation of the bellows type is used on the outside. The connecting mechanism 3 includes two crossed link arms 4, 5, each of which is linked at its front end to the front vehicle part 1 and at its rear end to the rear vehicle part 2. The connecting mechanism A, 5 is damped by two damping cylinders 6, 7 (shown only in Fig. 1 ), one for each link arm 4, 5, to control the movement between the front and rear parts of the vehicle.

During turning, the crossed arms give the car a self-stabilizing path, even when the motor is placed in the back of the car. This is obtained when the crossing point of the arms move towards the center point of the curve (see Fig. Ic).

The respective front ends of the link arms 4, 5 have a cavity through them, in which a corresponding front bearing housing 10, 11 with a front bearing 10a, 1 Ia, is mounted. The respective front ends of the link arms 4, 5 are connected by the front bearing housings 10, 11, to be their corresponding front coupling 12, 13 of the front car, which front couplings are arranged at approximately the same height from the ground and at a distance Ll from each other in a side connecting.

The respective front couplings 12, 13 include vertical bolts 14, 15 that are mounted on bearings in the corresponding front bearing housings 10, 11. The front ends of the link arms 4, 5, are thereby permitted to rotate about the longitudinal axis (X) of the vehicle and about its vertical axis (Z), but the vehicle also rotates about its transverse axis (Y) through the respective front coupling 12, 13 permitting a limited movement in the vertical connecting.

As can be seen in Fig. 3, the respective link arms 4, 5 form base L, turned almost opposite to each other, where the rear end is thicker and corresponds to the lower part of L. This makes it possible for the link arms 4, 5 to be able to change position without becoming stuck in each other.

The respective rear ends of the link arms 4, 5 have a rear cavity through them, in which a corresponding rear bearing housing 18, 19, with two rear bearings 18a, 18b, 19a, 19b are mounted. The respective rear ends of the link arms 4, 5, are connected by the rear bearing housings 18, 19 to be their corresponding rear couplings 20, 21 in the rear car, which rear bearings are arranged at approximately the same height from the ground at a distance L2 from each other in a side connecting.

The respective rear couplings 20, 21, include vertical bolts 22, 23 that are mounted on bearings in the corresponding rear bearing housings 18, 19. The rear ends of the link arms 4, 5 thereby permit turning about its vertical axis (Z).

As can be seen from the cross-section in Fig. 5, the respective link arms 4, 5 form two form-pressed halves 4a, 4b, 5a, 5b, an upper half 4a, 5a, and a lower half 4b, 5b, that are connected together with a longitudinal weld along the sides of the link arms 4, 5. In other words, two U-shaped halves 4a, 4b, 5a, 5b are connected against each other. This contributes to the link arms 4, 5 being able to handle very high loads with respect to the thickness of the material in the link arms 4, 5. This contributes to the link arms remaining very light with respect to their volume.

The size of the connecting mechanism 3 is kept short in length with the aid of the crossed link-arros 4, 5, which maxirm/e Hie space in the vehicle I ₅ 2 and give room for several more paying ρa<vsεπgεϊ\s

Through tbc radical weight reduction of the connecting mechanism 3, great synergies can be achieved:

- in producing the connecting mechanism 3 itself, through reduced material costs and energy consumption. ~ irs the operation of the vehicle. Increased revenue, since tbe operator can take more paying passengers without increasing the total axle pressure.

- This gives a car with less total resources in operation, and the total environmental effect is reduced.

- The bus manufacturer can demonstrate directly calculable economic savings for operators of bus fleets.

The link arms 4, 5 are preferably made of steel, preferably stainless steel, RST 4003 (EN 10088-2/1.4003), stainless EXl. '4301 (SS2333 ), Domex EN 10MO-2, DocoL But in certain cases, another material with similar characteristics can be used.

The two halves are preferably connected by a key-hole, plasma welding, laser welding, plasma hybrid welding, or laser hybrid welding.

Key-hole plasma welding has the following advantages, among others:

- very high welding speed - possibility of butt welding without additional material ~ secure through welding

- small zone affected by heat and low deformation of the plate material

- small filUng and penetration bead

Laser welding as the following advantages, among others: - very high welding speed

- deep penetration

- slight deformation

Plasma hybrid welding combines plasma welding with conventional MIG _' 'MAG welding and gives advantages, primarily through its ability to tϊSI joint plates. I aser hybrid welding combines laser welding with conventional MIGA'I λC J welding and gives advantages primarily through its ability to fill joint plates.

The halves of the link arras can be shaped by the following methods:

- Traditional press methods with forms and holders, advantageous for long series of about 4000 units/year, somewhat less accurate tolerances

- Quintus pressing, advantageous for short scries up to about 4000 units 'year and for complex shapes, high tolerance factor

- Hydro forming, possibility of designing complex details; the material goes to the form in one final piece. High tolerance factor.

Jn one embodiment that has been presented, the two halves are formed with Quititus forming and the Domex or RST 4003 material } EN 10088-2/1.4003), then connected with plasma hybrid welding.

A number of manufacturing steps for link arms are shown in Figure 7. A single system of reference points is used throughout, i.e., at least 3 points are controlled, and there may be several support points, to assure repeatability in the output. By always measuring the same strategically selected points, it can be seen directly where the chain needs to be acted on. These points should always be the same; in other words, for the upper form halves 4a, 5a, e.g., the hole centers with respect to each other, when the complete unit is viewed welded together, the former reference points become new reference points together. In this way, repeatability, traceability, and measurability are assured.

A raw material of high strength is placed flat in a form with reference points, then pressed to the desired shape by a hydraulic press or Quintus press, depending on the volume and desired tolerance of the output. A Quintus press gives better tolerances and a finer finished product; for larger series, however, a traditional hydraulic press machine is cheaper.

The halves are placed in a laser machine in a fixture with reference points when the pressed raw material is cut clean. The respective halves of the form 4a, 4b, 5a, 5b can be different, but surfaces of halves of articles that meet should be centered on and parallel to the opposite surfaces. In other words, the upper halves 4a, 5a and lower halves 4b, 5b can have different shapers, but a given thickness, but the surfaces that meet each other are preferably parallel and do not have large variations in the slit between each other; otherwise, there is a risk that plasma welding will not have proper bearing strength and the product can crack under high loads or wear when used in the vehicle 1, 2.

The two component halves 4a, 4b, 5a, 5b are placed against each other and constitute the final form.

After this, the bearing units 10, 18, 11, 19 are mounted in the respective link arms.

The halves 4a, 4b, 5a, 5b are attached to each other according to the reference points and then combined with the aid of a plasma hybrid weld or laser hybrid weld, preferably plasma hybrid weld, which is cheaper. The shape of the joint is preferably an I-shape.