CN1132813A - Steering system for surface compacting machines - Google Patents

Abstract

The invention relates to a steering system for tandem-type surface compacting machines equipped with two independent steering modes, e.g. machines equipped with both frame steering and with individual steering of one of the rollers. The object is to achieve simultaneous control of both systems, one enabled by a steering wheel-activated control valve an the other enabled by a joystick-activated electric control valve, arranged via switching valves which are activatable with an electric switch, in such a way that the machine operator can instantly select the steering system whose activation with the steering wheel or joystick respectively he deems most appropriate at any given moment.

Description

The steering of road roller

The present invention relates to the steering of tandem roller.This road roller has two independently to turn to pattern, and promptly in a kind of steering, or preceding pressure roller or back pressure roller can turn to separately, and as from United States Patent (USP) NO.3,868,194 is known; Perhaps in another kind of steering, allow frame-steering or one of them pressure roller to turn to separately.This pressure roller generally turns to by the pilot operated valve device control that a steering wheel starts, and pilot operated valve device is regulated the fluid that turns to oil cylinder and flowed.Start reversal valve and allow to select the oil cylinder that turns to wanted, oil cylinder works to preceding pressure roller or back pressure roller, and perhaps, second kind of situation, oil cylinder works to frame-steering or one of them pressure roller.

Patent right requirement according to the application, the present invention seeks to reach and handle two systems simultaneously, wherein a system is adopted the method for the control valve of steering wheel startup, the method to another system adopts control device affacts on the motor-operated control valve such as action bars.These two systems are by being configured to the reversal valve that electric switch is fitted together: the driver can any regulation the time standby he think only steering wheel or operating lever operation and select steering immediately.The flow of the reversal valve that steering wheel starts will be adapted to the size of corresponding pressure roller, and at this moment, turning velocity is influenced by the velocity of rotation of steering wheel; The switching valve that control stick starts is furnished with choke valve, can make to turn to slowly with steady.

The road roller of frame-steering normally starts frame-steering by steering wheel by its control valve, and wherein the track of two pressure rollers is because frame-steering and one in front and one in back.If want bigger effective pressure degree of having a lot of social connections, promptly to line up when trapezoidal when pressure roller, available control stick starts one of them pressure roller separately, and this pressure roller is rotated.This situation takes place when car moves, and road roller just curves.The steering wheel that rotate to start frame-steering then to be compensating this amount of curving and to keep straight circuit, and pressure roller is done shifted laterally in random or selected direction.The switching valve that is started by control stick also can be used to make the road roller during the normal operation to turn to, and affacts the pressure roller that turns to separately then.Like this steering geometry is exerted an influence, make the track of pressure roller with the turning track of vehicle frame not on same circuit.This can show very big advantage in various different work, for example just have advantage near the operation of road tooth or when the cutout facility being housed on pressure roller therein when the machine road roller.

Compactor operator can be selected the steering of suitable utilization with steering wheel or control stick immediately at any given time.

Referring now to accompanying drawing, the present invention will be described.Fig. 1 represents the lateral view of a tandem roller.Fig. 2 is the horizontal plane figure of Fig. 1, represents that a frame-steering section header and one turn to section header and steering spindle cylinder separately on pressure roller therein.Fig. 3 is the hydraulic schematic diagram of one embodiment of the invention.

In Fig. 1, back vehicle frame part 1 is linked front frame part 2 by frame-steering section header 3.The back pressure roller 4a of road roller is contained on the roller frame 5a, and roller frame 5a is contained in bearing 6 places of back vehicle frame part 1 rotationally.Preceding pressure roller 4b is contained on the roller frame 5b, and roller frame 5b is fixed on the front frame part 2.

Fig. 2 represents to turn to oil cylinder 7 to make frame-steering by vehicle frame section header 3, turns to oil cylinder 8 to affact on the roller frame 5a, and roller frame 5a can turn to around bearing 6 together with pressure roller 4a.

Fig. 3 is the oil circuit figure of hydraulic steering system, and wherein oil pump 9 is furnished with reducing valve 10, links the rotary control valve 11 of steering wheel startup and the motor-operated control valve 12 that control stick starts through pressure oil circuit CF.Be an adjustable throttling 13 before motor-operated control valve 12, can set up suitable fluid flow by it.When steering wheel is turned left respectively and is turned right, control valve 11 just by turns feed flow flow to R and L oil circuit.The proportional relation of the velocity of rotation of the equidirectional dish of flow.Liquid stream stopped when steering wheel stopped operating.When electrically-controlled valve 12 is not activated, block liquid stream by electrically-controlled valve 12, but when control stick to the right or when moving left, limited liquid stream passes through reversal valve 14 and flow to the oil cylinder that turns to that is connected with steering, cause road roller to the right or to left movement.Startup one to control stick stops, and control stick just turns back to its cutout meta, thereby motor-operated control valve is also got back to it and blocked meta.4 reversal valves 14 are linked frame-steering oil cylinder 7 and pressure roller in couples respectively and are turned to oil cylinder 8, are changed their position of function by the electric switch (not shown) in the drivers' cab.When starting frame-steering, by pressure controlled one way valve 15, fluid can flow back to control valve 11 from the low-pressure section that turns to oil cylinder 7.If start control stick control, fluid flows to fuel tank 17 with corresponding manner, and pressure controlled one way valve 16 allows oil to flow back to from the low-pressure section that turns to oil cylinder 8.Frame-steering system and pressure roller steering will reach with the configuration of two overflow valves 18 and two one way valves 19: if prevent the steering overload when very large external applied load takes place, just this situation may occur when pressure roller clashes into certain hard object such as road tooth etc.

Claims (4)

1. a control has the method for the tandem roller of two independent hydraulically controlled steering, described two steering can alternately enable them by the control device that compactor operator starts, the feature of this method is that described control device has two devices that can start simultaneously: the control valve (11) by the steering wheel startup that is used for one of them control system, and electrical control valve (12) that for example starts that is used for another control system by control stick, they are configured to: compactor operator can be selected by the steering wheel or the control system of control stick startup at once with an electric switch, thereby can control two steering simultaneously.

2. in accordance with the method for claim 1, it is characterized in that control valve (12) that control stick starts makes that the steering that is activated has slowly, turning velocity stably, and the turning velocity of the steering of being enabled by the control valve (11) that steering wheel starts depends on the velocity of rotation of steering wheel.

3. device of realizing the described method of claim 1, the switch that it is characterized in that the steering that starts with steering wheel or control stick is a tumbler switch of linking four reversal valves (14), when the tumbler switch tripping, the spool position of reversal valve (14) changes simultaneously, Tong Guo oil feed line L1 and R1 thereby switch from the liquid flow point of control valve (11), cause frame-steering oil cylinder (7) to turn to oil cylinder (8) to work to pressure roller, meanwhile, the startup pressure roller from control valve (12) turns to the liquid rheology of oil cylinder (8) to change startup frame-steering oil cylinder (7) into.

4. device of realizing the described method of claim 2, it is characterized in that the control valve (11) that steering wheel starts is a revolving valve, when steering wheel rotated, control valve (11) control was flowed through the liquid that reversal valve (14) flows into steering, made the proportional relation of velocity of rotation of the equidirectional dish of liquid stream flow; The control valve (12) that control stick starts produces steady, adjustable liquid stream by the adjustable throttling (13) in its front, supplies with connected steering through reversal valve (14).

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