DE2029998A1 - Method for regulating the lifting of an arm articulated to a frame and lifting device for carrying out this method - Google Patents

Description

description

In certain applications, for controlling the setting of two related components, e.g. a A hydraulic cylinder connected between the two components is used. So the boom of a road construction machine, in relation to the headboard or platform to which it is hinged.

In most of these use cases, the imprint that Carry out operation in the least possible time unit. All that is needed is the selection of the various components and the type of cylinder as well as its arrangement on the head part and on the arm, the length of the arms etc ... on the machines in use however, it is found that the movement or manipulation

009852/1643 '

BATH ORIGINAL

a certain, ex. load attached to the end of the boom is carried out within a certain period of time while moving or manipulating a load that is half as large is executed within the same period of time. Since the coupling required for lifting in the second pail is only half of the in the first lall raised load, it would be expected that with the same drive force, the second movement is carried out twice as fast as the first, it being assumed that the first load is equal to the upper limit load. So far, however, no device is known which allows such a mode of operation.

However, machines are known in which the maximum lifting clutch of a cylinder can be regulated without modifying it has been made possible by changing the position of the force application point of the cylinder, this change as required and is not automatically effected.

The Applicant wanted to improve this state of affairs and _p for the accomplishment, it intended to proceed in a new way, by creating the opportunity to work with the maximum extent permitted by the required lifting clutch speed, of course, the movement a force that does not exceed a specified value must be carried out.

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0098S2 / 1643
BATH ORIGINAL "'"

The invention initially relates to a method for controlling the with the greatest possible speed caused lifting of an arm pivotably articulated on a frame by means of a hydraulic fluid pressurized cylinder without the expended Force exceeds an estimated value. Here, there is a dependency of the position of at least one of the joint axes of the cylinder from the level of the feed pressure of this cylinder.

The invention also has one for performing this method certain lifting device to the object, which consists of an arm pivotably articulated on a frame, from an arm between the latter Arm and a component that can be adjusted with respect to the frame switched on cylinder and consists of a control element regulating the position of the component. The control element is controlled by the cylinder's feed pressure

In a preferred embodiment, the control member consists of ί a second, switched between the frame and the cylinder component, said second cylinder is connected by means of a distributor slide valve with either a hydraulic fluid supply and a surge tank. The slide is subjected to the action of the liquid of a branch line of the pressure liquid feed of the cylinder connected between the arm and the adjustable component. ■

009852/1643

BAD ORJQfNAt

In an advantageous embodiment, a between the feed and return lines between the ensures. Arm and the adjustable component arranged cylinder switched on "switching block ^11, the connection of the second cylinder to the hydraulic fluid supply when a first cylinder space of the two

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see the arm and the adjustable component arranged cylinder is fed with hydraulic fluid while he is the second The cylinder separates when the first cylinder space of the cylinder arranged between the arm and the adjustable component is separated is.

The first cylinder space of the cylinder arranged between the arm and the adjustable component forms the one during lifting of the arm articulated to the frame with the hydraulic fluid supply connected to the cylinder space.

Finally, in a preferred embodiment, there is the holding block formed by a first check valve which is arranged in a branch line of the line that is connected to the supply of the first cylinder space between the arm and the adjustable Component arranged cylinder and can be connected to one of the cylinder chambers of the second cylinder »

Second and third check valves are in one with the other Cylinder space of the second cylinder connectable line arranged, which work in opposition to each other.

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The third, in relation to the second cylinder beyond the second 'Check valve arranged check valve is · of the Fluid pressure; the line controllable, the one with the supply. of the first cylinder space of the cylinder arranged between the arm and the adjustable component can be connected, and the circulation of that contained in the line in which it is arranged ! Allows fluid in both directions as soon as its control pressure is above a specified value.

In the course of the following description of an exemplary embodiment the invention will also be better understood secondary features as well as their advantages will emerge. The description and the drawings are self-evident It is intended to be illustrative and not restrictive . ■ ■ '

Show in the accompanying drawings

fig. 1 is a partial view of a machine on which an inventive Lifting device is attached j

Flg. 2 shows a schematic view of a lifting device according to the invention and

Fig. 3 is a schematic view of a modification of the Fig.

device shown. -

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SADORK & NAC

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The machine in which the device according to the invention is used finds, has a head part 1, on which a boom is articulated pivotably about an axis 3. A first cylinder 4 is connected between the boom 2 and a component 5 which is pivotable about an axis 6 on the head part 1 is appropriate. The cylinder 4 is pivotable about an axis 7 on the boom 2 and about an axis 8 on the pivotable component 5 articulated ο Finally, a second cylinder 9 is between the head part 1 and the component 5 by means of axles 10 and 11 switched on.

According to a first, in Pig. 2 has illustrated embodiment the feed circuit of the cylinders 4 and 9 is a source of pressurized fluid 12, ex. a hydraulic pump, which the cylinder by means of a bsp. by a lever 14 manually operated three-way distributor 13 dines. An expansion tank 15 is provided for the return of the liquid.

When lifting the boom 2, the cylinder 4 is through the line 16 fed. The liquid pressure in the line 16 is limited by an adjusted valve 17, which may contain the liquid leads to the expansion tank or tank 15.,

From the line 16 branches off a line 18, which is in a cylinder 19 for controlling the position of the slide of a three-way distributor valve 20 opens, with the slide under the opposite direction Effects of the liquid of the line 18 and

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BAO

a spring 21 is in equilibrium. The cylinder 9 is means of the distributor 20 is fed by a pressure fluid source 22. A set valve 23 limits the feed pressure of cylinder 9 o

The pressure fluid sources 12 and 22 can be transformed into one and the same pump are combined, as is provided in the second embodiment ₀ lines 24 connecting the two cylinder spaces of the cylinder 9 in the distributor 20th

A second embodiment is shown in FIG. It contains certain parts that correspond to those already described and have the same reference numerals as those.)

The device is supplemented by a single pump 25 with the distributor 13 is connected by a line 26. A line 27, which leads back to the tank 15 via an adjusted valve 28, is used as a branch in the line 26 in a known manner.

Two lines 29 and 30 connect the two cylinder spaces 4a and 4b of the cylinder 4 in the manifold 13, the line 29 at adjoins the cylinder space 4a, which at the moment of the lifting of the boom 2 via the distributor 13 with the return line 26 of the Pump 25 is connected.

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Between the lines 29 and 30, a "circuit block ¹¹ 31 is provided two conduits 32, 33 connect this switch block 31 with a three-way distributor slide 34;. They are extended through the manifold 34 out through lines 35, 36 which of the cylinder chambers 9a and 9b Cylinder 9. The distributor 34 ensures either the separation of the lines 35 »36 or the connection of these lines 35, 36 with the lines 32, 33 or vice versa with the lines 33, 32.

On the other hand, a pressure transducer 37 (capteur de pression), which consists of a piston 38 slidably mounted in a cylinder housing 39, is connected to the line 29 by a line 40. Opposite the cylinder space 37a, into which the line 40 opens, and on the other side of the piston 38, a spring 41 is arranged in the cylinder space 37b between the piston 38 and the cylinder housing 39. The piston rod 42 of the piston 38 is arranged precisely coaxially thereon.

In the example shown, the distributor 34 and the cylinder 37 are connected to the frame of the machine, e.g. with the head part 1, firmly connected, while a connecting lever 43 connects the moving parts of the distributor 34, the cylinder 37 and the cylinder 9 to one another. Accordingly, the axis 11 is hinged the piston rod of the cylinder 9 on the lever 43, the axis of the cylinder body 44 slides the piston rod 42 37 in a slot 45 provided in the connecting lever 43, and wherein 'speaking on unloading, the axis 46 of the slider of the manifold 34 in

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an elongated hole 47 of the lever 43 slides,

The switch block 31 will be described below. First it should be made clear that its function is to separate the cylinder spaces 9a and 9b of the cylinder 9 as soon as the cylinder 4 is not applied, in other words, as soon as ex. the cylinder space 4a is separated from the pump 25 and the tank 15 at the same time is.

Among the various that can be performed to ensure this function Devices, the switching block 31 is preferably selected. It advantageously has four check valves, two of which are controlled.

A first check valve 48 is arranged in line 32, which is connected to line 29. The check valve 48 allows the flow of the liquid of the line 29 to the Distributor 34.

A second check valve 49 is arranged in line 33, which is connected to line 30. This check valve 49 allows the liquid of the manifold 34 to flow therethrough the line 30.

A third check valve 50 is in the line 33 ', namely with respect to the manifold 34 beyond the check valve 49, This check valve 50 is arranged via a line 51

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BADORiQlNAt

connected to line 32. The line 51 is connected to the line 32 between the check valve 48 and the connection of the line 32 connected to line 29. It is opposite the check valve 49 built in.

A fourth check valve 52 is in the line 29, namely below or in the direction of flow before the connection point the lines 32 and 29, arranged. This check valve 52 is connected to the line 33 via a line 53 which is connected to the line 33 between the check valve 50 and the connection of the Lines 30 and 33 are connected »The check valve 52 allows the flow of the liquid of the distributor 13 to the cylinder space 4a of the cylinder 4.

It remains to be clarified that the check valves 50 and 52 in the lines 33, 29 in which they are arranged control the flow allow the liquid in both directions as soon as the control pressures of the liquid in the lines 51, 53 are greater than the predetermined response values are, as soon as these pressures ex. are not zero

The mode of operation of the machine described above is in fact completely new compared to that of previously known machines.

With regard to the first embodiment shown in FIG is, two mutually corresponding modes of action are presented, namely the first for lifting the boom 2 without a contradiction

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BAOORfOfNAt

stand would exist, and the second to lift a large load.

If in a first section of the boom 2 bsp. is to be lifted without a load, the cylinder 4 is fed through the line 16, wherein the slide of the distributor 13 is moved into the relevant position. When the resistance against lifting is weak, the pressure in line 16 required for lifting is low and below the set pressure of the Valve 17. The effect of the pressure in the control cylinder 19 of the slide of the distributor 20 is less than that of the spring 21 such that that the distributor 20 is in a position in which it acts on the cylinder 9 in the direction of the G-elenkachs'e 11. ■.

In this way, the cylinders 9 pulls the component J5 and transferred it from the broken-line position 5 'in the fully extended position 5. This causes at a given supply pressure in the line 16 and a predetermined flow rate, that is at a similar predetermined force, shortening the lever arm of the lifting coupling, ie ultimately lifting with a coupling force that is weaker than before, but is nevertheless sufficient for lifting, but also with a greater lifting speed. This means that a small load can be lifted very quickly.

The reverse is true in the second case, if one of the preceding Embodiment goes out, the pressure in the line 16 is practical

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equal to the set pressure of the valve 17 · The slide of the distributor 20 is then adjusted by the control cylinder 19 in this way that the "cylinder space located on the side of the joint axis 10 of the cylinder 9" is fed with pressure fluid. The component 5 is moved back to position 5 '. The arm of the lifting coupling becomes longer, i.e. the coupling force increases and the speed increases decreases accordingly. It can thus be lifted more slowly than before, but a greater load.

It should be noted that it is sufficient to balance the slide of the distributor in the middle position with a slight the pressure of the line 18 which is below the set or response pressure of the valve 17 is to be provided so that the cylinder 9 is fed in such a way that the component 5 is acted upon in the sense of lifting the load at the highest possible speed, wherein the pressure in the cylinder 4 is limited to a predetermined value.

In other words, the device according to the invention regulates continuously the position of the component 5, i.e. the position of the joint axis 8 of the cylinder 4 on the head part in such a way that with the greatest speed permitted by a given lifting force is raised. As soon as the Hebedruok under the action of the control cylinder 19 on the slide of the distributor 20 below the maximum pressure given to feed cylinder 4 falls, cylinder 9 is fed to shorten the lifting lever arm, i.e. to increase the lifting speed.

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Of course, the speed is none the less limited by an end position of the component 5 and by a maximum feed flow rate of the cylinder 4, a flow rate, which is at most equal to a given value.

If, on the other hand, the lifting clutch force were weaker than the resistance, the lifting speed would automatically be reduced to the extent that that the clutch force is greater than the resistance.

So you always have the highest possible speed that the shortest possible operating time and the best possible efficiency of the lifting device} all of this happens in one perfectly automatic way.

It is obvious that the question of the maximum speed arises when lowering does not pose in the same way. The pressure in the line 16 is then zero (return of the liquid to the expansion tank 15) and component 5 is set to ensure operation at maximum speed.

If no adjustment of the boom 2 is effected, but meanwhile the pressure in the cylinder space of the cylinder 4 rises, which is usually fed during the lifting of the boom 2, the control cylinder 19 and thus the cylinder 9 is then actuated, which is an indirect and undesired one Change of boom 2 has the consequence. This way of working can, for example. be that of a crane operator when a load is lifted from the ground by means of a hoist

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should be lifted without changing the position of the boom to the ground. If the booms are held immovable it appears necessary to provisionally apply the compensation device (dispositif d'asservissement) described above neutralize."

This result is achieved by using, for example, the second execution Sk Rungsform achieved, which will be described below with reference to Pig, 3 is described »

When the cylinder space 4a of the cylinder 4 _S, which is usually fed with hydraulic fluid at the moment of the lifting of the boom 2, in the position of the example shown in FIG. The distributor 13 shown is separated from the tank 15 and the pump 25, it should be noted that there is little or no pressure in the line 30 and thus in the line 53, that the check valve 52 prevents the flow of the liquid in the cylinder chamber 4a to the distributor and that the liquid pressure in the line 29 above the valve 52 with respect to the cylinder 4 is weak or zero. The pressure in the line 51 is also weak or zero, so that the check valve 50 is controlled in such a way that it only allows liquid in the line 30 to flow to the check valve 49. It can be readily seen that the counter-acting check valves 49 and 50 block the flow in the line 33 and thereby separate one of the cylinder spaces of the cylinder 9, whatever the position of the slide of the distributor 34 may be. Aue of this embodiment it follows that the cylinder 9

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BADORiQlNAL. :

"remains blocked and the position of component 5 is temporarily not more changes, which allows to keep the boom 2 immobile, whatever the current ex. from lifting one load resulting from excess pressure without the desired movement of the boom may be in the cylinder space 4a of the cylinder 4. Of course it is known that the pressure in the various cylinders is limited by an exhaust valve; if therefore accidentally a load exceeding the maximum design of the machine is to be lifted, this would lead to leakage of the cylinder space 4a of the cylinder 4 lead. However, this only applies to a .. outside the normal use of the machine and provides a safety device that would work in this exceptional case.

The device derpig. 3 also permits the automatic position correction of the component 5. When to be raised in a first case, the boom 2, one fed by the pump 25, the line 29 by the matching set manifold 13. The ZY λ relieving space 4a is also fed with pressure fluid, while the cylinder space 4b is set to reflux to the tank 15 via the line 30.

When the liquid pressure in the line 29 and thus in the line 40 drops and the lifting resistance is weak, the spring 41 pushes the piston 38 of the cylinder 37 back quite considerably. From it it follows that when the axis 11 is currently stationary, the piston rod of the piston 42 of the cylinder 37 pulls on the connecting lever 43,

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so that it pivots about the axis 11. This moves the slide of the distributor 34> which then has the lines 32 and 35 and 33 and 36 connects. The pressure fluid contained in the line 29 is fed through the lines 32 and 35 and the check valve 48 apart from the cylinder space 4a of the cylinder 4, the cylinder space 9a of the cylinder 9 · At the same time, the check valve 50 held open by the control pressure of the line 51, so that the liquid of the cylinder space 9b of the cylinder 9 through the lines 36 and 33 and the check valves 49 and 57 to the line 30 and the tank 15 can flow out. This operational phase causes the axis 11 to be shifted in the correct sense for setting the position of the component 5 and, in addition, the pivoting of the connecting lever 43 about the axis 44 of the piston rod 42 of the cylinder 37 », this axis 44 being fixed in the line 40 for a given pressure. The movement of the connecting lever 43 puts the slide of the distributor 34 in a central position Position.

If, contrary to the case described, the pressure in the lines 29 and 40 increases, you get an analog working method, but in the opposite sense.

In addition, it should be noted that each feed pressure of the cylinder chamber 4a of the cylinder 4 corresponds to a position of the piston 38 of the cylinder 37. A control of the component is thus obtained 5 for a continuous feed pressure curve of the cylinder space 4a and not a regulation through pressure thresholds as in the first

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Embodiment. -

Finally, it should be noted that when the lowering of the Boom 2 is controlled by operating the distributor 13, wherein this time the line 30 is connected to the return of the pump 25 and the line 29 to the tank 15, the drain of the in the cylinder chamber 4a contained liquid through the check valve 52, which is controlled by the control pressure of the liquid lines 30 and 53 are kept open, is possible

Finally, the invention is not limited to that described above Embodiment limited, but also covers all modifications that, without departing from its scope, fall under the concept of the invention fall. .

The position of the component 5 could thus be regulated by the cylinder 9 is, by a guide device, ex. a sliding guide, the axis 8 of the cylinder 4 can be replaced, the gate I direction in a modified embodiment by a one Screw driving motor is controlled.

Likewise, in order to ensure that the method according to the invention is carried out, not only the hinge pin 8 of the cylinder 4 can be regulated with regard to their position, but it can- ' te also the second hinge axis 7 can be provided with a gate direction according to the axis 8 that is determined to regulate its position.

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Finally, for the same purpose a control of the position could be at least one of ^G-1 elenkachsen be provided of the cylinder, which is arranged between the boom and the swing levers of the machine.

009852 / 18A3

Claims (6)

Claims 1·. Method for regulating the lifting of an arm pivotably articulated to a frame by means of a cylinder loaded with pressure fluid, which is effected at the highest possible speed, without the applied force exceeding an estimated value , characterized in that a dependency of the position of at least one of the articulation axes of the | Cylinder is produced by the level of the feed pressure of this cylinder. 2. Lifting device for carrying out the method according to claim 1, which consists of an arm pivotably articulated on a frame, a cylinder connected between this arm and a component that is adjustable with respect to the frame, and a control element regulating the position of the component, characterized in that the control member is controlled by the feed pressure of the cylinder. 3. Apparatus according to claim 2, characterized in that the control member consists of a second cylinder connected between the frame and the component and that this second cylinder is optionally connectable by means of a distributor slide with a Druckflüseigkeitsspeisung and a reservoir, the slide of the action of the liquid one Branch line of the hydraulic fluid supply between the ■ -2- 009852/1643 Arm and the adjustable component is subject to the sown cylinder. 4. Apparatus according to claim 3 » characterized in that a switched between the feed and return lines of the cylinder arranged between the arm and the adjustable component" switching block "ensures the connection of the second cylinder with the hydraulic fluid supply when a first cylinder space between the arm and the cylinder arranged to be adjustable is fed with pressure fluid while it separates the second cylinder when the first cylinder space of the cylinder arranged between the arm and the adjustable element is separated. 5. Apparatus according to claim 4, characterized in that the first cylinder space of the cylinder arranged between the arm and the adjustable component forms the cylinder space which is in communication with the hydraulic fluid supply during the lifting of the arm hinged to the frame. 6. Device according to one of claims 4 or 5, characterized in that the switching block is formed by a first check valve which is arranged in a branch line of the line which is connected to the supply of the first cylinder space of the cylinder arranged between the arm and the adjustable component and is connectable to one of the cylinder chambers of the second cylinder, while second and third check valves in 009852/1643 one with the other cylinder space of the second cylinder yer-bindable conduit are arranged, which act opposite to each other, the third, with respect to the second cylinder Check valve arranged on the other side of the second non-return valve can be controlled by the fluid pressure of the line is that with the supply of the first cylinder space of the arranged between the arm and the adjustable component Cylinder is connectable, and the circulation of the in the line, in which it is arranged, liquid contained in both Allows directions as soon as its control pressure is above a predetermined value. 009852/1643 Le e rs ei f e