WO1989001435A1

WO1989001435A1 - Special vehicle with movable steering mechanism and driver's cab capable of being lowered

Info

Publication number: WO1989001435A1
Application number: PCT/CH1988/000125
Authority: WO
Inventors: Walter Baiker
Original assignee: Walter Baiker
Priority date: 1987-08-14
Filing date: 1988-07-18
Publication date: 1989-02-23
Also published as: CH675102A5

Abstract

A special vehicle has a cross-country steering system and a cab capable of being lowered. A hydraulically assisted steering mechanism of the front axle is provided. A hydraulically assisted steering column assembly (8) is directly secured by securing means (18, 35) to the axle body (13) and/or to the change gearbox (34) of the axle, and is supported thereby. This construction allows the front axle and the cab to move relative to each other. When it is lowered, the cab describes a curved line, i.e., it moves not only in the vertical direction but also diagonally in the forward direction and around the front wheels. It thus become possible to make superstructures with a long boom pivot through 360° when the cab is lowered. At the same time, the vehicle has a short length and can be safely steered by means of the described steering system during translational movements of the front axle as well.

Description

S P E Z I A L F A H R Z E U G H I T B E W E G B A R E M L E N K M E C H A N I S M U S U N D A B S E N K B A R E R

F A H R E R K A B I N E

The invention relates to a special vehicle according to the preamble of claims 1 and 7.

Many special vehicles; such as crane, fire brigade or weapon vehicles, have body elements with a large opening. At the same time, the largest possible swivel range is required in operation, which in the optimal case is 360 °.

The major disadvantage of conventional special vehicles is that the driver's cab, whose size and position cannot be freely selected, proves to be an obstacle in operation. If, for example, crane booms, fire brigade ladders or weapon attachments with gun barrels are to be rotated in a horizontal position, the swivel range is restricted to approximately 300 ° because of the driver's cabin. This means that such vehicles have to be put down for work or that the arms of the equipment bodies have to be raised for a full turn in the area of the driver's cab. In the case of crane and weapon carrier vehicles in particular, this places a significant restriction on the operational given enough, so that trailers or _t very long vehicles are often used. One difficulty is that in very many cases the vehicle cannot be brought into the required position or position due to its large and limited maneuverability, and the required work area can therefore often not be reached.

Various obstacles are in the way of solving the problem. On the one hand, the driver's cab cannot be dimensioned arbitrarily small, since drivers with a height of 1.90 m must also find space in it, on the other hand, the total height of the vehicle, including the body, must not exceed 4 m. Furthermore, the driver's cab cannot be placed anywhere in front of the steering axis, where a problem-free up and down movement would be possible, but is necessarily arranged so that the steering wheels of the front vehicle axis are a hindrance when the cabin moves.

It is an object of the invention to provide a special vehicle which, even in large driver's cabs, allows equipment bodies with long cantilevers to be rotated through 360 °, is controllable at any time and can be used in the field, has great traffic safety even with very large axle loads, and a short one Construction length and high maneuverability allowed.

This object is achieved by the features mentioned in the characterizing parts of claims 1 and 7;

The vehicle according to the invention has an off-road steering system and a lowerable cabin. When lowering the cabin describes a curve line, ie the movement is not only in vertical, but in both the horizontal and vertical directions. This makes it possible for the cabin to be lowered even with large front wheels by being guided around the wheels or the fenders by a corresponding lifting / lowering mechanism. By executing the lowering mechanism by means of articulated lever arms, preferably in the form of a parallelograph, the steering ability is not impaired when lowering. The steering is not attached to the chassis or the cab as usual, but is built onto the axle body itself, which enables precise steering even when the cabin is lowered. Another advantage of this arrangement of the steering mechanism is that additional relative movements of the front axle and the cabin, such as, for example, adjusting the height of the vehicle or leveling the cabin, are possible without the steerability being impaired. In addition, the steering is not affected by movements of the steering axle during deflection or off-road.

Exemplary embodiments of the invention are explained in more detail with reference to the following drawings.

1 shows a side view of a crane vehicle with a lowerable cabin.

FIG. 2 shows a side view of the crane vehicle according to FIG. 1 with the cabin lowered in the course of work.

Fig. 3 shows a longitudinal section through the driver's cabin and the steering mechanism.

Fig. 4 shows a steering axis according to the invention in the view from the front. 5 shows the steering axle according to FIG. 1 with the holding plate removed in a view from the front.

6 shows a cross section through the axis according to FIG. 4 along the section line A-A.

7 shows an axis according to FIG. 4 in a view from above.

In the example of a crane vehicle shown in FIG. 1, a driver's cab 1, a crane structure 41 with a crane boom 42, and a lifting / lowering device 4 for the movement of the cabin 1 can be seen. The crane boom 42 is telescoping extendable manner by means of a hydraulic system and can be adjusted in the inclination ^'. The driver's cab 1 is in the driving position, ie in the raised position for driving on the road.

FIG. 2 shows the crane vehicle according to FIG. 1 with the cab 1 lowered. The crane structure 41 is rotated in a working position by 180 ° with respect to the rest position. Since the driver's cab 1, which is suspended by means of articulated arms 2, is lowered almost to the ground, it is easily possible to move the crane boom 42 over the cab 1 in order, for example, to carry out work in the driver's field of vision. Even in its lowest position, ie in a horizontal position, the crane boom 42 can be rotated through 360 ° without the driver's cabin being a hindrance. This is of great advantage, for example, when working in low rooms. The cabin 1 is suspended by means of a plurality of articulated arms 2, which form part of the lifting / lowering device 4. FIG. 3 shows a detailed sectional view of the driver's cab 1 and the steering mechanism. The cab is again in the driving position. The articulated arms 2, which are articulated to the driver's cab 1 and a holding device 30, are held in the raised position by one or more hydraulic cylinders 31. The bearing axes or the articulated points of these articulated arms form the corner points of a parallelogram, viewed from the side. If the hydraulic cylinder or the hydraulic cylinder 31 is adjusted, the front ends of the articulated arms 2 move along a circular path and accordingly the cabin 1 moves as well - Form pedes, and two hydraulic cylinders are provided on each side of the cabin, so the cabin can be moved up or down in a horizontal orientation even when the chassis is tilted. This is achieved in that the two cylinders 31 are adjusted in a coordinated manner, ie the right and left cylinders have a different stroke in accordance with the inclination of the vehicle. Since the driver's cab shifts relative to the chassis or the vehicle axles, in particular the steering axle, during the up or down movement, the steering must be transmitted in such a way that the steering is not impaired during these movements of the cabin.

In order to achieve the shortest possible construction of the vehicle, the mounting device 30 is preferably arranged above the front wheels 14 or even behind them. This makes it possible to raise the cabin by means of the articulated arms 2 so that the rear wall thereof lies above or also behind the front wheels 14. When lowering, the cabin moves obliquely forward, as will be explained in more detail below, so that the steerability of the wheels 14 is not impaired. With a suitable construction of the holding device 30 and the articulated arms 2, the cabin is moved up and down in such a way that the elements lying in the area of the front wheels 14 do not hinder the wheel turning, which means that the cabin also during the Ride up and down can be moved. This is achieved in that the cabin moves on an essentially circular or elliptical path and the articulated arms 2 are so long that all elements of the cabin are always at least about the radius of the front wheels 14 from the front axles.

In order to ensure reliable maneuverability or good steerability of the vehicle even on uneven terrain, the cabin 1 preferably has its own suspension that is independent of the rest of the vehicle. For this purpose, for example, a spring or diaphragm accumulator can be provided in the oil supply system of the cylinder 31 lifting the cylinder 1. This memory can either be switched on or off.

In special vehicles that are also used off-road, ie also on uneven ground, »the vehicle axles make large movements in relation to the chassis. This brings with it additional problems for satisfactory steerability, in particular when large axle loads are transmitted to the steering axle. This poses the problem of assembling the steering system so that there are no obstacles to sensitive relative movements between the steering axle and the chassis or driver's cabin. The steering system according to the invention solves this problem by a novel design and arrangement of the steering system. This contains a steering wheel 33, a steering spindle 3, an angular gear 5, and a transmission shaft 7 with two sections 7a, 7b and a universal joint 6 for the steering transmission, as well as further elements not visible in this figure. The transmission shaft 7 has in the rear Section 7b a toothed sliding sleeve for the compensation of length differences when the driver's cab 1 or the front axle 32 moves. By turning the steering wheel 33, the control movement is transmitted via this steering system to the steering column not shown in this figure.

FIG. 4 shows an exemplary embodiment of a steering axle according to the invention viewed from the front. A bracket plate 18 is fixedly connected to the axle body 13. A mounting structure for a hydraulic spindle steering column 8 and two auxiliary cylinders 15, 16 (FIG. 5) concealed here are attached to this mounting plate 18. The steering column 8 is connected on the one hand via its input shaft 27 to the rear section of the transmission shaft 7b and on the other hand to a steering arm 9. Furthermore, the piston rods 11, the short tie rod sections 12 and a connecting rod 10 and corresponding connecting elements 25, 26 can be seen. The two piston rods 11 are each connected at their ends by a connecting element 25 or 26. The steering transmission is primarily purely mechanical, but is supported by hydraulic support in the steering column 8 and additionally by the two hydraulic auxiliary cylinders 15, 16 and their piston rods 11. The mechanical tracking by means of the lever 9 and the connecting rods 10 is intended to provide a mechanical steering connection from the steering wheel to the wheels 14. On the one hand, greater steering precision can be achieved on the one hand, and on the other hand there is the possibility, even if only conditionally, according to regulations, in the event of an engine failure the vehicle to steer by hand.

Figure 5 shows, also from the front, the steering axis, with the mounting plate 18 being removed. This makes the two auxiliary cylinders 15, 16 visible. The piston rods 11 are continuous, wherein they have a hydraulic piston 17 in the middle. The The application area for the hydraulic oil on both sides of the piston 17 is of the same size and, accordingly, the same amount of oil or the same oil pressure is required both for steering movements to the left and to the right. As can easily be seen, the piston rods serve at the same time as an intermediate member of the tie rod sections 12, with which they are connected in an articulated manner via the connecting elements 25, 26. The two auxiliary cylinders 15, 16 serve as a guide.

FIG. 6 shows a cross section through the steering axis and the holding plate 18. The mounting plate 18 is connected to the axle gear housing 34 or the axle body 13 by means of mounting elements 35. The two auxiliary cylinders 15, 16 with the piston rods 11 and the hydraulic spindle steering column 8 are fastened to it. Connection openings 19, 20 are provided on the auxiliary cylinders 15, 16 for connecting the hydraulic lines or hoses. The shaft 7 is connected to the hydraulic spindle steering column via a shaft stub 27 and by means of a universal joint, not shown, which is pushed and fastened over the shaft. The mechanical steering transmission is thus ensured by the steering arm 9.

Figure 7 shows a view of the steering axis from above. The axle body 13, the axle drive 34, 37 with a differential integrated therein as well as the mounting device 18, 35 and the steering column 8 can be seen. It can also be clearly seen that the steering column 8 connected to the axle body 13 or the axle transmission housing 34 via the holding device 18, 35 via the steering arm 9, the connecting rod 10, the connecting elements 25, 26 and the articulated thereon Coupled tie rod sections 12 is connected both to the wheels, which are not visible here, and to the auxiliary cylinders 15, 16, which are concealed here. Movements of the steering arm 9 are thereby transmitted via the connecting rod 10 and the connecting elements 25, 26 both to the tie rod sections 12 and to the piston rods 11. The supply and discharge lines 21-24 are provided on the hydraulic spindle steering column and are preferably connected to the hydraulic cylinders 15, 16 by hoses. Instead of hydraulic hoses, pipe connections can also be used.

So that very heavy vehicles can be controlled, the additional steering support is designed in a new way as a so-called 2-circuit steering system. Hydraulically assisted steering systems have been used in conventional large delivery and lorries with 2 or 3 axles and tractors for more than 15 years. The hydraulic support usually takes place in the steering column, ie the steering column contains a hydraulic piston which, in a manner similar to the present hydraulic spindle steering column, facilitates the movement of a steering arm when the steering is actuated. In this case, even with small rotary movements of the steering wheel, a hydraulic valve is opened, which directs oil supplied by a hydraulic pump to the double-acting piston of the steering column, so that the steering movement is supported. In the case of even heavier vehicles, e.g. four-axle trucks, in which two front axles have to be steered or vehicles with an axle load of more than six tons on the steering axle, such hydraulic support by the hydraulic spindle steering column is no longer sufficient. So far, therefore, an additional, double-acting hydraulic cylinder has been attached somewhere on the steering transmission linkage and connected to the hydraulic system of the hydraulic spindle steering column in such a way that the oil flow coming from the pump was also supplied to this hydraulic cylinder when the steering was operated. For even heavier Fahr¬ vehicles with axle loads substantially greater than six tonne ^'n on the steered axles (heavy purpose vehicles) and at relatively high speeds, that is larger than the previously usual 30 to 40 Kilometers per hour, this solution is also insufficient with an additional hydraulic cylinder. There is in particular the risk that a pipeline breaks or a hydraulic hose bursts and the vehicle would consequently no longer be steerable due to the failure of the hydraulic cylinder. Additional safety precautions are therefore necessary.

The steering system according to the invention therefore uses two parallel auxiliary steering cylinders 15, 16, which in the present exemplary embodiment are arranged one above the other. The two auxiliary cylinders 15, 16 each have openings at their ends and each have a continuous piston rod 11 with corresponding pistons 17. Connections 19, 20 cause the oil flow coming from the hydraulic spindle steering column via lines 21-24 to the auxiliary cylinder Change 15, 16 fed and discharged. One cylinder is supplied via one line pair 21, 22, the other via the second line pair 23, 24. The hydraulic spindle steering column, which in turn also has a hydraulic piston, contains two mutually independent control blocks and correspondingly separate control valves or valve units, which work independently of one another. The hydraulic spindle steering column provided for the steering system according to the invention accordingly has 4 connections, ie one connection on the left and one on the right for the cylinder 15 and for the cylinder 16. This ensures that if one auxiliary cylinder fails, the other thanks to the separate one Oil supply circuit continues to work without any problems. The vehicle loses oil, but can be steered without difficulty until it stops. Since the piston rods 11 are rigidly coupled at their ends by means of the connecting elements 25, 26, the non-functional cylinder is also carried along and the transmission of steering to the tie rod sections 12 is guaranteed. The auxiliary cylinders 15, 16, the hydraulic spindle steering column 8 and the shaft end 27 are carried by the mounting plate 18 and form a unit which is carried by the axle body 13. The piston rods 11 guided in the auxiliary cylinders 15, 16, which at the same time perform the function of an intermediate member of the tie rod sections, are thus connected to the axle. In this way, a precisely functioning steering of the heavily loaded axle is possible even on uneven terrain, where the axle can twist relatively strongly and constantly move up and down.

Claims

PATENT CLAIMS

1. Vehicle with steering of the front axle and hydraulic Kraft¬ support, characterized in that a hydraulically assisted steering column (8) by means of fastening devices (18, 35) attached to the axle body (13) and / or the axle gear housing (34) and by this (n / s) is worn.

2. Vehicle according to claim 1, characterized in that the steering system, with the exception of the steering spindle and sections of a transmission shaft (7a) mounted on the driver's cab or the chassis, in particular a steering arm (9), a steering column (8) and a section of the The steering shaft (7b) connecting the steering shaft to the steering spindle is connected to the front axle of the vehicle in such a way that, together with the front axle of the vehicle, it can carry out translational movements relative to the vehicle chassis or the driver's cab without any steering differences .

3. Vehicle according to one of claims 1 or 2, characterized in that at least two tie rod sections 12, which are connected via at least two hydraulic auxiliary steering systems (11, 15, rigidly interconnected by means of connecting elements (25, 26), 16) are connected to each other for guiding the front wheels (14).

4. Vehicle according to claim 3, characterized in that the hydraulic auxiliary steering systems are designed as hydraulic cylinders (15, 16) with continuous piston rods (11) and are integrated into the tie rod as intermediate links between two tie rod sections (12).

5. Vehicle according to claim 3 or 4, characterized in that the two hydraulic auxiliary steering systems (11, 15, 16) are controlled by separate supply lines (21, 22, 23, 24) and form an actively redundant system.

6. Vehicle according to one of claims 3 to 5, characterized in that the auxiliary steering systems are fastened by means of mounting devices (18, 35) on the axle body (13) and / or the axle drive housing (34, 37) and by this ( n / s) are worn.

7. Vehicle with a lowerable driver's cab, characterized gekenn¬ characterized in that the driver's cabin (1) in the rear area by at least 4 parallel articulated arms (2) which with the driver's cab and by means of a bracket device (30) with the chassis or with the Body are articulated, suspended and can be raised and lowered by means of a hydraulic system (31).

8. Vehicle according to claim 7, characterized in that the mounting device (30) and the rear wall of the cabin (1), when the latter is raised, is in the area above the front wheels (14) or behind them.

9. Vehicle according to claim 7 or 8, characterized in that the length of the articulated arms (2) is greater than the radius of the front wheels (14), so that the cabin (1) swings out at an angle when lowering and does not impair the steerability of the wheels (14) in any position.

10. Vehicle according to one of claims 7 to 9, characterized gekenn¬ characterized in that when lifting and lowering the cabin (1) by their elements in the area of the front wheels (14) described curves with respect to the front wheel axis over their entire area at least have a distance which corresponds to the radius of the front wheels (14) and the cabin is at least approximately horizontal in every position, so that the vehicle can be driven while the cabin is being moved.

11. Vehicle according to one of claims 7 to 10, characterized in that the cabin (1) contains its own suspension which is independent of the rest of the vehicle and which is lifted by means of a cylinder () in the oil supply system of the cabin (1). s) (31) provided spring or diaphragm accumulator can be switched on and off.