RU2625695C1 - Hydraulic steering system for heavy trucks - Google Patents

Abstract

FIELD: transportation.

SUBSTANCE: hydraulic steering system for heavy trucks contains the pressurised operating fluid flow amplifier, communicated to the steering gear distributor and with the rod ends of four cylinders and two additional distributors, communicated to the head ends of four cylinders. Four cylinders are made as single-rod. The pressurised operating fluid flow amplifier is provided with the pressurised operating fluid flow direction selection distributor, communicated to the rod ends of four cylinders. The head ends of each cylinders pair is communicated to one of additional distributors. The control domes of the additional distributors are communicated with solenoid valves connected to non-contact position sensors of the vehicle moving elements.

EFFECT: design simplification and the hydraulic system maintenance.

6 cl, 8 dwg

Description

The invention relates to transport machinery, in particular to hydraulic vehicle control systems, mainly mining trucks.

Known hydraulic steering for heavy vehicles [1, Mariev P.L., Egorov A.N. etc. Heavy-duty mining dump trucks. Design, technology, marketing / P.L. Mariev et al., Minsk: Integralpolygraph, 2008, pp. 124-126, fig. 2.6.1], comprising an amplifier for working fluid flow under pressure, in communication with the steering distributor and with the cavities of two single-rod cylinders.

The disadvantage of such a hydraulic system is that it can be used for steering according to the scheme of turning the front wheels of a heavy vehicle, observing the exact parameters of the angle of rotation of these wheels from the selected design parameters of the wheelbase, which reduces the versatility of the hydraulic system and is not suitable for the acceptable maneuverability of heavy heavy vehicles vehicles, for example armored vehicles or mining trucks of extra-high carrying capacity (over 450 tons), for which go turn agreed not only the front but the rear axle.

Known more universal and effective for the maneuverability of heavy vehicles, the hydraulic steering system [2, Patent RU 2488508, IPC B62D 5/06, B62D 15/00, priority 04.24.2012, publ. 07.27.2013], adopted as a prototype. It contains two amplifiers of the working fluid flow under pressure, one of which is communicated through the distributor of the steering mechanism with the cavities of two two-cylinder cylinders, and the other of which is communicated with the cavities of the additional two-cylinder cylinders through the flow divider and two additional distributors associated with one of the rods of the additional two-cylinder cylinders other rods of which are connected with pre-compressed centering threshold springs.

The disadvantage of the prototype [2] is the complexity of the design and maintenance of the hydraulic steering system due to the presence of two flow amplifiers in the hydraulic system, which are fed from two hydraulic tanks through two pumping stations, as well as due to the presence of two rods in two-rod main and additional cylinders and communication their rods with additional elements of the hydraulic system - two additional valves and pre-compressed centering threshold springs.

In addition, such a hydraulic steering system allows it to be used in the classic scheme of turning the wheels of heavy vehicles relative to their axles. However, such a turning pattern limits the increase in carrying capacity of heavy vehicles. A more progressive scheme of their rotation is to control the coordinated circular movement of the bridges themselves relative to each other, for example, mounted on slewing rings rotated by hydraulic system cylinders.

The objective of the invention is to achieve a technical result aimed at simplifying the design and maintenance of the hydraulic steering system, as well as providing the possibility of its application for the scheme of rotation of heavy vehicles using the coordinated circular movement of their axles relative to each other.

The problem for the invention is solved in that the hydraulic steering system for heavy vehicles, comprising a pressure enhancer for working fluid flow in communication with a steering distributor and with rod cavities of four cylinders, and with two additional distributors communicated with piston cavities of four cylinders, distinguishing features: four cylinders are single-rod, the pressure fluid flow amplifier is equipped with a directional selection valve eniya flow of hydraulic fluid under pressure communicated with the rod end of the four cylinders, each pair of piston cavity which communicate with one of the extra valves, which control chamber communicated with the electromagnetic valves connected to the proximity sensors of the vehicle position of the moving elements.

The introduction to the amplifier of the working fluid flow under pressure of the distributor of the choice of the direction of flow of the working fluid under pressure is aimed at eliminating the need, as in the prototype [2], the use of two complex constructional amplifiers of the flow of working fluid under pressure, which is aimed at simplifying the design and maintenance of the steering hydraulic system management.

The communication of the distributor for choosing the direction of flow of the working fluid under pressure with the rod cavities of four single-rod cylinders, the piston cavities of each pair of which are connected with one of the additional valves, will allow for the creation of a simple control scheme for turning two vehicle bridges, which also aims to simplify the design and maintenance of the hydraulic system steering.

Communication of control cavities of additional distributors with electromagnetic valves connected to non-contact position sensors of the vehicle’s moving elements will create a new simple tracking system for turning the rear axle of the vehicle depending on the rotation of its front axle, which also aims to simplify the design and maintenance of the steering hydraulic system with such an extension of its functionality.

Together, all the distinguishing features of the invention will allow the use of a hydraulic system in a progressive turning system of heavy vehicles by controlling the coordinated circular movement of their bridges relative to each other, which ensures the creation of heavy vehicles with a carrying capacity of over 450 tons.

Additional features of the invention in relation to the hydraulic steering system:

- it is in communication with a collector energy storage device, consisting of pneumohydroaccumulators and an additional electromagnetic valve;

- piston cavities of four single-rod cylinders are also in communication with relief valves;

- the amplifier of the working fluid flow under pressure in the place of its communication with the stock cavities of four single-rod cylinders, as well as the collector energy storage device, are equipped with safety valves;

- single-rod cylinders are paired with a movable solid ring of the slewing ring.

The invention is illustrated by illustrations, where in FIG. 1 shows, by way of example, a general view of a heavy vehicle in which the hydraulic steering system of the invention can be installed; in FIG. 2 is a diagram of the location of bridges of such a vehicle with four single-rod cylinders under its cargo platform; in FIG. 3 is a view A of FIG. 2, with a diagram of a bridge device; in FIG. 4 is a section BB in FIG. 2 to the partially illustrated slewing ring device of FIG. 3; in FIG. 5 shows a functional diagram of a steering hydraulic system as applied to the axle layout of a heavy vehicle of FIG. 2; in FIG. 6 is a schematic diagram of a hydraulic steering system of FIG. 5; in FIG. 7 is the same as in FIG. 2, but with the rotation of one bridge of a heavy vehicle; in FIG. 8 is the same as in FIG. 7, but with the turn of its two bridges.

The device according to the invention is used for heavy vehicles and is installed, for example, on a mining dump truck (Fig. 1), having, as the propulsors of the wheel 1, the front axle PM and the rear axle ЗМ, mounted movably on the skeleton 2, on which the cargo platform 3 and the motor compartment 4 with cab 5.

Each PM and ZM bridge of a mining truck contains a central body 7 connected to the on-board housings 8 on which the wheels 1 are mounted. The rotary housings 6 are equipped with a slewing ring 9 (Figs. 1-4), consisting of a fixed composite ring 10 (Fig. 3, 4), which is fixed by the studs 11 (Fig. 4) on the skeleton 2 and the movable integral ring 12, which is fixed by the studs 13 on the rotary housing 6. The movable integral ring 12 is equipped with treadmills 14 in contact with the rolling bodies - rollers on top and bottom 15 located between him and b govymi tracks 16 fixed ring 10 of the composite.

Moreover, the slewing ring 9 is attached to the skeleton 2, and is made with the possibility of its rotation (Fig. 7, 8) to the right and left by means of the steering hydraulic elements 17 connected to the rotary housing 6 6 and with the skeleton (Fig. 2, 5 , 7, 8) a dump truck (Fig. 1).

On the skeleton 2 (Fig. 2) of the dump truck, limiters 18 are installed in pairs. They are designed to limit the rotation of the common axle bridges at angles α (Fig. 7) and δ (Fig. 8). For this purpose, the stops 19 are fixed on the rotary housings 6 between the stops 18 on the skeleton 2.

The central housings 7 are connected to the rotary housings 6 through central levers 20 (Fig. 3), the shoulders of which are connected to the suspension elements 21, for example, shock absorbers and / or dampers, which are also connected to the rotary housings 6. The central housings 7 can be connected to the rotary the housing 6 using a mounting element, for example a two-shoulder articulated lever 22.

The hydraulic steering system 17 (Fig. 5, 6) for heavy vehicles, such as a mining truck (Fig. 1), contains (Fig. 5, 6) an amplifier for working fluid flow under pressure 23 (in Fig. 6 circled by a dot-dash line) communicated with the distributor of the steering mechanism 24 (in Fig. 6 circled by a dash-dot line) and communicated with the rod cavities 25 of four cylinders 26-29, which are single-rod, through the distributor for selecting the direction of flow of the working fluid under pressure 30.

The hydraulic steering system 17 also contains two additional distributors 31 and 32 (in Fig. 6 circled by a dot-dash line), in communication with the piston cavities 33 of the four cylinders 26-29.

The control cavity 34 (Fig. 6) of the additional valves 31 and 32 are in communication with the solenoid valves 35, 36 (Fig. 5, 6) connected via an electric relay control unit 37 (Fig. 5) to the proximity sensors 38-40 (for example, induction) the position of the rotary elements of a heavy vehicle on which such a hydraulic steering system is installed 17. In the shown example of a heavy vehicle, such as a mining truck (Fig. 1, 2), such rotary elements are movable integral rings ring 12 (Figs. 3, 4) of pivoting wheels 9 mounted on pivoting housings 6, while contactless sensors 38-40 can be fixed (not shown) to the core 2 so that the contactless sensors 38 and 39 are located on the right and on the left, on the skeleton 2 near the front axle of the PM dump truck, with the possibility of triggering from the rotary housings 6 in their extreme positions, and the proximity sensor 40 is centered on the skeleton 2 near the rear axle of the ЗМ with the possibility of triggering, for example, from the rotary housing 6 during bias from the original Independent user position.

The control cavity 41 (Fig. 6) of the steering gear distributor 24 is in communication with the hydraulic motor 42 (Fig. 6), which, like the steering gear distributor 24, is kinematically connected, for example, by means of a cardan-articulated lever gear 43, to the steering wheel 44 mining truck.

With its inputs, the amplifier of the working fluid flow under pressure 22 (Fig. 6), as well as additional distributors 31 and 32, are connected to the hydraulic pump 45, which is fed from the hydraulic tank 46 of the dump truck through the pressure line 47, which also communicates the input of the collector energy storage 48 (in Fig. 6 is outlined by a dash-dot line), consisting of pneumatic accumulators 49 and an additional solenoid valve 50.

The outputs of the said units 23, 31, 32 and 48 are in communication with the hydraulic tank 46 through the drain lines 51. In the drain line 51, in communication with the amplifier of the flow of the working fluid under pressure 23, a filter 52 is installed.

To increase the reliability of the hydraulic steering system, the piston cavities 33 of the four single-rod cylinders 26-29 are also in communication with the blocks 53 (outlined in dotted lines in FIG. 6) of the unloading valves 54, and the hydraulic fluid flow amplifier under pressure 23 at the place of its communication with the rod cavities 25 four single-rod cylinders 26-29 and in the place of its communication with the drain line 51, as well as the collector energy storage 48, are equipped with safety valves 55.

The amplifier for the flow of working fluid under pressure 23 also contains a two-line valve 56, priority valve 57 and on-off valves 58, in series with the distributor for choosing the direction of flow of the working fluid under pressure 30.

In the necessary places of the hydraulic system of the steering, check valves 59, throttles 60 and fittings of the control output 61 are installed.

Through the control lines 62 (shown in dashed lines in Fig. 8), the steering distributor 24 is in communication with the hydraulic fluid flow amplifier under pressure 23 and with additional distributors 31 and 32. Through the drain line 63 (also shown in dashed lines in Fig. 6), the steering distributor the mechanism 24 is in communication with the drain line 51 in front of the filter 52.

Thus, a dual-circuit hydraulic steering system 17 (Fig. 5, 6) of a mining dump truck (Fig. 1) of a hydrostatic type with internal hydraulic feedback is obtained.

The steering structure of such a heavy vehicle is based on the principle of alternately turning its steered axles - the PM front axle and the ZM rear axle (Figs. 2, 7, 8).

The principle of operation of the hydraulic steering system 17 (Fig. 5, 6) for heavy vehicles is as follows.

After starting the engine (not shown) in the engine compartment 4 (Fig. 1) of the mining truck, the flow of the working fluid by the hydraulic pump 45 (Fig. 6) is fed through the collector energy storage 48 to the amplifier flow of the working fluid under pressure 23 and to the additional distributors 31 and 32 . From the collector energy storage medium, the working fluid is supplied to charge the pneumohydroaccumulators 49.

Pneumohydraulic accumulators 49 are intended for accumulation under pressure of the working fluid, which enters the steering hydraulic system to feed it, as well as in an emergency situation when the supply of the working fluid from the hydraulic pump is interrupted for any reason.

The presence of pneumatic hydraulic accumulators 49 in the hydraulic system makes it possible, when the engine stops suddenly or the hydraulic pump 45 fails, turn the steered front and / or rear axles of the PM, ZM of the mining truck from one extreme position to another extreme position and return them back to the exit to a safe place and stop such a heavy vehicle .

When a mining truck moves, for example, in a straight line (Fig. 2), cylinders 26-29 (Figs. 2, 5 and 6) of its hydraulic steering system are in a neutral position and they do not receive working fluid under pressure.

In this case, the steering wheel 44 occupies a predominantly neutral position, in which the working fluid received to the power fluid flow amplifier under pressure 23, as well as to the steering gear distributor 24 and to the additional distributors 31 and 32, is blocked by the spools of the listed hydraulic units. Therefore, the rod cavities 25 and the piston cavities 33 of the cylinders 26-29 are blocked. At the same time, the control cavities 34 of the additional distributor 32 of the rear axle ZM are connected by electromagnetic valves 35, 36 to the drain line 51, and the control cavities 34 of the additional distributor 31 of the front axle PM are connected by its electromagnetic valves 35 and 36 to the control line 62 of the steering gear distributor. In this case, the supply of working fluid from the steering distributor to the additional rear axle distributor 32 of the ЗМ is blocked by electromagnetic valves 35 and 36, and the additional PM front axle distributor 31 with the additional rear axle distributor 32 of the ЗМ are connected to each other by feedback through their chokes 60 and through the steering gear distributor 24 with a drain through the filter 52 along the drain line 51 to the hydraulic tank 46.

When the steering wheel 44 is turned to the left, the working fluid from the distributor of the steering mechanism 24 enters along the control line 62 to the amplifier for the flow of working fluid under pressure 23, ensuring its entry into the rod cavities of the cylinders 27 and 29 and to the additional distributor 31 of the PM front axle. In this case, the steering gear distributor 24 and the rod cavities 25 of the turning cylinders 26 and 29 communicate through the amplifier of the working fluid flow under pressure 23 with a drain. Through the control cavity 34 of the additional distributor 31, the working fluid from the collector energy storage 48 enters the piston cavity 33 of the cylinder 26. The front axle rotates to the left. From the opposite piston cavities 33 of the cylinders 26 and 27 of the PM front axle, the working fluid is displaced through the distributor 31 with a drain through the filter 52 along the drain line 51 into the hydraulic tank 46.

As a result, the rotary housing 6 (Fig. 1 and 2) of the front of the dump truck together with the movable solid ring 12 (Fig. 4) of the support-rotary circle 9 of the front axle PM (Fig. 7) is rotated along the rollers 15 (Fig. 4) -turn circle 9 to the required angle and rotates the wheels 1 (Fig. 7) depending on the angle of rotation of the steering wheel.

When the rotation of the steering wheel 44 is stopped, the steering distributor 24 and the control cavity 34 of the additional front axle distributor 31 PM are connected to the drain, as described above. In this case, the additional distributor 31 and the amplifier of the working fluid flow under pressure 23 return to their original position, blocking the rodless cavities 25 and rod cavities 33 of the cylinders 26 and 27 of the PM front axle, respectively, stopping its rotation. The rear axle ZM remains in a position corresponding to the movement of a mining truck in a straight line (Fig. 7).

If it is necessary to perform a maneuver by a mining truck with a smaller radius (further turning it steeper), while continuing to rotate the steering wheel 44 to the left, the steering system provides rotation of the rotary housing 6 (Fig. 8) together with the wheels 1 of the rear axle ЗМ of the mining truck in a similar way, but in the opposite direction from the front axle PM. Restricting the rotation of the PM and ZM bridges to the angles α and δ is carried out by the contact of the corresponding limiters 18 to the stops 19 installed on the skeleton 2.

In this case, the sensor 38 of the extreme left position of the PM front axle is activated, providing voltage (Fig. 5 and 6) to the electromagnetic valves 35 and 37 of the additional valves 31 and 32, respectively, of the PM front axle and the rear axle ЗМ. Therefore, the additional distributor 32 of the rear axle ЗМ communicates with its electromagnetic valves 35 and 36 with the distributor of the steering gear 3, and the additional distributor 31 of the front axle PM communicates with its electromagnetic valves 35 and with the drain. The supply of working fluid from the steering distributor 24 to the control cavity 34 of the additional distributor 31 is blocked by its electromagnetic valves 35 and 36. The working fluid along the control lines 62 enters the rod cavities 25 of the turning cylinders 27 and 29. In this case, the rod cavities 25 of the cylinders 26 and 28 are connected through flow amplifier A8 with drain. The control cavity 34 of the additional rear axle distributor 32 ZM passes the working fluid from the collector energy storage 48 into the piston cavity 33 of the rear axle cylinder 28, which rotates to the right. From the rod cavities of the 25 cylinders 28 and 29, the working fluid is displaced, respectively, through the amplifier of the working fluid flow under pressure 23 to drain into the hydraulic tank 46.

When the rotation of the steering wheel 44 is stopped, the power fluid flow amplifier under pressure 23 returns to its original position, blocking the rod cavities 25 of the cylinders 26, 27. The steering gear distributor 24 and, accordingly, the additional rear axle distributor 32 of the rear axle communicate with the drain in the hydraulic tank 46. As a result, an additional distributor 32 and the amplifier of the working fluid flow under pressure 23 return to their original position, blocking the piston cavities 33 and the rod cavities 25 of the cylinders 28, 29, respectively. one hundred ZM stops.

Upon exiting the left turn, the rear axle ZM first turns, reaching a position corresponding to the movement of a mining truck in a straight line (Fig. 7). In this position, the proximity sensor 40 of the middle position of the rear axle 3M is triggered, providing a shutdown of the voltage to the solenoid valves 35 and 36 (Fig. 5 and 6). As a result, the additional distributor 31 of the front axle PM communicates with its electromagnetic valves 35 and 36 with the distributor of the steering gear 24, and the additional distributor 32 of the rear axle PM communicates with its electromagnetic valves 35 and 36 with the drain line 51. The control cavity of the additional distributor 32 blocks the piston cavities of 33 cylinders 28 and 29 of the rear axle ЗМ. The supply of working fluid from the steering distributor 24 to the control cavity of the additional distributor 32 is blocked by the solenoid valves 35 and 36 of the rear axle ЗМ.

With further rotation of the steering wheel 44 to the right, the working fluid from the distributor of the steering mechanism 24 enters through the control line 62 and then to the amplifier for the flow of working fluid under pressure 23, providing it to the rod cavities 25 of the turning cylinders 26 and 28 and to the control cavity of the additional distributor 31 and 32 front axle PM. The rod cavity 25 of the cylinders 27 and 29 are connected through an amplifier for the flow of a working fluid under pressure 23 with a drain. The control cavity of the additional distributor 31 passes the working fluid from the collector energy storage to the rodless cavity 33 of the cylinder 27. The front axle PM rotates to the right. From the rod cavities of 25 cylinders 26 and 28, the working fluid is displaced through the amplifier of the working fluid flow under pressure 23 into the drain line 51.

Piston cavities 33 of cylinders 26-29 are in communication with relief valves 54, which are designed to relieve pressure spikes in cylinders 26-29 in the event of an emergency.

When a dump truck hits an obstacle that causes extreme load, which tends to rotate its rear and front axles (PM, ZM), the pressure in the opposing cylinder cavities will increase the pressure relief valve. Unloading valves 54 are adjusted to a pressure of 38 MPa. When this pressure is reached, any of them can open and inform the corresponding piston cavity 33 of one of the cylinders 26-29 with the piston cavity 33 of the other hydraulic cylinder.

The pressure of the working fluid in the hydraulic steering system (Fig. 5 and 6) is determined by the setting of the unloading machine (not shown) of the hydraulic pump 45 at a pressure of 17-21 MPa, the limit level - by setting the safety valves 55 25 MPa.

Thus, this use of slewing rings 9 in the bridges of a mining truck and the above-described construction of this bridge according to the invention in a mining truck with its rotation using the above-described construction of an automobile slewing device

- apply eight tires of the same size instead of the traditionally used six tires, which is aimed at increasing the carrying capacity of a mining truck to 450 tons and above;

- to provide the ability to rotate two bridges of such a vehicle relative to its integral frame, which will significantly improve maneuverability and reduce the overall dimensions of a mining truck,

and is also aimed at improving the stability of the corners of a mining truck and at improving its maneuverability, and at the same time increasing its carrying capacity.

The invention is implemented in the construction of a dump truck BELAZ-75710.

Information sources

1. Mariev P.L., Egorov A.N. etc. Heavy-duty mining dump trucks. Design, technology, marketing / P.L. Mariev et al., Minsk: Integralpolygraph, 2008, pp. 124-126, fig. 2.6.1.

2. Patent RU 2488508, IPC B62D 5/06, B62D 15/00, priority 04.24.2012, publ. 07/27/2013 / prototype for the hydraulic system /.

3. Mariev P.L., Egorov A.N. etc. Heavy-duty mining dump trucks. Design, technology, marketing / P.L. Mariev et al., Minsk: Integralpolygraph, 2008, p. 14, 15, 25, 127-139, fig. 1.1.2, 1.1.4, 2.6.2-2.6.4, 2.6.8, 2.7.1 / prototype for the dump truck /.

Claims (6)

1. The hydraulic steering system for heavy vehicles, comprising a pressure enhancer for working fluid flow in communication with a steering distributor and with rod cavities of four cylinders, and two additional distributors in communication with piston cavities of four cylinders, characterized in that the four cylinders are single-rod , the amplifier of the working fluid flow under pressure is equipped with a distributor for selecting the direction of flow of the working fluid under pressure in communication with the rod olostyami four cylinders, each pair of piston cavity which communicate with one of the extra valves, which control chamber communicated with the electromagnetic valves connected to the proximity sensors the position of movable parts of the vehicle. 2. The hydraulic system according to claim 1, characterized in that it is in communication with a collector energy storage device, consisting of pneumatic accumulators, an additional solenoid valve and a safety valve. 3. The hydraulic system according to claim 1, characterized in that the piston cavities of the four single-rod cylinders are in communication with relief valves. 4. The hydraulic system according to claim 1, characterized in that the amplifier for the flow of working fluid under pressure in the place of its communication with the rod cavities of the four single-rod cylinders is equipped with relief valves. 5. The hydraulic system according to claim 1, characterized in that the amplifier for the flow of working fluid under pressure also contains priority and safety valves. 6. The hydraulic system according to claim 1, characterized in that the single-rod cylinders are paired with rotary bodies.

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