FI87437B - Steering device - Google Patents

Description

87437 STEERING SYSTEM STYRNINGSANORDNING The invention relates to a vehicle steering system in which the body steering and steering by means of swiveling wheels are combined ± y for operation with a single control device, most often a steering wheel or rudders, and that the combination of the two steering modes is optionally combined.

Vehicle body steering is already known and used in a number of implements, most often those in which all the wheels are the same size, as well as in cases where high load capacity is required on both axles of the vehicle. I.In addition, frame steering is widely used to steer vehicles with multi-axle rollers, as well as in cases where the rear wheels of the vehicle are desired to follow the groove of the front wheels.

A combination of front-wheel steering and a kind of frame steering is known in Finnish Publication No. 53951, in which a joint is placed outside the backhoe on which a support wheel is mounted, which can be moved laterally and vertically, but the structure is inelastic and the weight of the front of the vehicle rests on only one of its two steering wheels, and the invention does not comprise any combination of steering.

; Long vehicles, such as graders, also have a steering arrangement in which, in addition to the known steering wheel turning of the front wheels, it is possible to use the foot pedal to control the turning of the frame joint in both directions. In this case, the vehicle is equipped with two independent control modes known per se.

In addition, there are known steering arrangements in which the frame steering is enhanced, by an additional arrangement, most often by a reversing brake, or as in DK patent 148793 B, if the folding of the folding vehicle body, and thus steering, is achieved by individually adjusting the speed of all driving wheels .

5 A weakness of the current known solutions, especially in the case of tractor agitator adjustment, is that when driven by the front wheel alone, the tractor excavator is clumsy when using a front loader, as the loader rotates with a large radius and requires a lot of free space. If the backhoe loader is frame-guided, 10 then it is substantially better in front loader operation, but then it has equal front and rear wheels and poor visibility past the wheels. In addition, in this case the engine is placed high, above the front axle and visibility over the bonnet is also poor.

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When, in a frame-guided tractor, the frame joint is usually very close to the center point between the front and rear axles, this means that the rear wheels follow the tracks of the front wheels very closely. In excavator operation, this causes problems in digging a straight ditch 20, because if the excavator's front wheels deviate from the intended driving line and are steered back to the desired line by frame control, the rear wheels in turn move away from the desired line and the ditch alignment deviates. In addition, it is difficult to use the full rollers 25 in frame-only tractors alone, because these tractors generally do not have brake control in use.

The disadvantage of grader control is that the frame and front wheels are controlled by two separate independent 30-racket controls. This requires special concentration from the driver and impairs road safety. In addition, especially on work machines, there are several control devices on the hands and feet to be controlled simultaneously, which results in unnecessary strain during driving.

The method according to the invention provides a decisive improvement in the above-mentioned drawbacks by combining the frame steering and the front wheel steering in a new way. To achieve this, the invention is characterized by what is set forth in the characterizing part of claim 1.

The invention will now be described in detail with reference to the accompanying drawings, in which:

Figure 1 shows the operation diagram of the control system.

Figure 2 shows a frame and front wheel steered vehicle in different steering situations 3,0,0.

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In the control system diagram of Figure 1, part (1) is a power supply, which can be e.g. a pump. The devices (2a and 2b) are controls, one of which is the steering wheel and the other the foot pedal. These use control devices (3) which are hydraulic-15 valves. The device (4) is a cross-connection device with which the operation of the turning devices (5a, 5b, 5c) can be varied between the control devices (2a, 2b). The turning device (5a) is a steering wheel turning device, the turning device (5b) is a second steering wheel turning device, and the turning device (5c) is a frame steering turning device. The devices (6) are position sensors. The device (7) is a microprocessor-based electronic control center, the devices (8) are the braking devices of both braking wheels in reversing braking, the device (9) is a speed sensor and the device (10) is a control center for selecting 25 control modes.

; Figure 2a shows a vehicle comprising a front frame: (11) and a rear frame (12) connected to it by a frame joint (13), as well as front wheels (14) and rear wheels (15) and turned to a position where the frame steering and front wheel steering increase each other Reverse effect.

Figure 2b shows a vehicle comprising a front frame (11) and a rear frame (12) 35 connected to it by a frame joint 1 (13), as well as front wheels (14) and rear wheels (15) and turned to a position where the frame steering and front wheel steering cancel each other out .

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Figure 2c shows a vehicle comprising a front frame (11) and a rear frame (12) connected to it by a frame joint (13), as well as front wheels (14) and rear wheels (15), and in which the front wheel steering and frame steering are adjusted to cause reversal effect in the same direction, but at a different magnitude.

Claims (6)

1. A method for steering wheel and frame steering vehicles, in particular a tractor, in which frame steering and steering with one or more wheels lying at least on one axle are combined to operate together by the use of a steering means (23,2b) characterized by It is possible that a control unit can be set in a control unit, that when the said control means, the frame control and the steering wheel / steering are moved, both ways in relation to each other cause simultaneous steering action which are different and changing. Method according to claim 1, characterized in that a control method can be selected in the steering unit, in which frame steering and steering with steering wheels / partially or completely compensate each other's turning effect. Method according to claim 1 or 2, characterized in that the pulse coming from the driving speed sensor reads the frame control. Method for steering vehicles according to any one of claims 1-3, characterized in that the steering angles of two or more steering wheels are independently adjustable. Apparatus for realizing the method according to claim 1 in a vehicle comprising the frame guide by means of "a frame joint (13) and the wheel guide with a steering wheel / s and an electronic control center (7) which controls the control means note that the control center (7) comprises devices for selecting and maintaining different hanging relations between said control modes. Apparatus according to claim 5, characterized in that each control device (5a, 5b, 5c) is provided with the steering angle sensor (6).