DE102021208932B3 - stabilization module - Google Patents

Abstract

Stabilization module (1) for stabilizing the working movement of a hydraulic consumer of a working machine, preferably a construction machine and in particular a shovel of a wheel loader, with a stabilization module connection valve (2) hydraulically actuated by a pilot valve (16). When the stabilization module sequence valve (2) is in a working position, there is a hydraulic connection between a pressure accumulator line (12) of the stabilization module (1) and a pressure line (6) acting in the load-lifting direction of the consumer and between a tank line (18) with an in Load-lowering acting pressure line (8) made, and in its basic position, these connections are separated. A connection that can be established via a hydraulic control line (10) between a control side of the stabilization module sequence valve (2) and the pilot valve (16) is controlled by the stabilization module sequence valve (2) itself.

Description

technical field

The present invention relates to a stabilization module for damping a movement of a shovel of a mobile working machine, e.g.

Background of the Invention

In the case of hydraulic systems of wheel loaders, switchable hydraulic (vibration) damping is known, for example for the shovel of a wheel loader. The hydraulic damping/hydraulic suspension of this type has the function of reducing a pitching movement of the wheel loader, which occurs particularly when the wheel loader drives over uneven terrain with a loaded, currently inactive bucket and at high speed.

From the EP 0 388 641 B1 such a hydraulic suspension for a wheel loader shovel is known.

When putting such a hydraulic suspension into operation and taking it out of operation, i.e. during the transition from pump operation (for actuating, i.e. raising and lowering the shovel) to storage operation (for resilient storage of the shovel) and vice versa, unintentional up and down resp. Pitch movements of the blade occur. These movements result from a possible pressure difference between the working pressure in pump operation and the current accumulator pressure of the hydraulic accumulator. When rapidly changing between the two operating conditions, this pressure difference can cause the blade to move. It has been shown that when the known hydraulic suspension is added, the movement of the shovel is generally greater than when the hydraulic suspension is removed. Such unintentional movements of the shovel are often surprising and disturbing for the wheel loader driver and should therefore be avoided.

State of the art

DE 10 2018 210 471 B3 discloses a generic hoist suspension for a shovel hoist of a wheel loader. A switching valve, in particular a proportional pressure control valve, is controlled by an activation valve (pilot valve). The proportional pressure control valve is designed to selectively connect a hydraulic accumulator via a pressure accumulator line with (lifting) cylinders of the lifting gear and thus to dampen oscillation of the shovel via the switched-on pressure accumulator. This means that the proportional pressure control valve can increase and decrease the accumulator-supported hydraulic suspension/damping depending on the current operating status of the lifting gear.

The lift suspension/damping also includes a shut-off valve that can connect the accumulator line to a tank. If the pressure in the accumulator line becomes greater than a pressure in a line connecting to the cylinder, the shut-off valve to the tank opens and relieves pressure in the accumulator line. Thus reveals the DE 10 2018 210 471 B3 a solution to reduce or avoid excessive pressure in the accumulator line.

The shut-off valve in the DE 10 2018 210 471 B3 must be hydraulically tight when closed and is therefore complex to manufacture. The low production tolerances required for this result in high production costs and complex quality control.

Summary of the Invention

It is therefore an object of the invention to provide a hydraulic suspension or a stabilization module that overcomes the disadvantages of the prior art and offers a structurally cost-effective solution. It is a particular object of the invention to provide a stabilization module that dispenses with the shut-off valve and still does not allow excessive, rapid blade movement when the hydraulic suspension is switched on/added.

This object is achieved by a stabilization module having the features of claim 1. Advantageous developments of the invention are the subject matter of the appended dependent claims.

The invention therefore relates to a stabilization module for stabilizing the working movement of a hydraulic consumer of a working machine, preferably a construction machine and in particular a shovel of a wheel loader with a stabilization module connection valve hydraulically actuated by a pilot valve. In an (actuated) working position of the stabilization module sequence valve, a hydraulic connection is established between a pressure accumulator line of the stabilization module and a pressure line acting in the load-raising direction of the consumer and between a tank line and a pressure line acting in the load-lowering direction. In a (non-actuated) basic position of the stabilization module sequence valve, these connections are separated. According to the invention, a connection that can be produced via a hydraulic control line between a control side of the stabilization module sequence valve (for its actuation) with the front control valve controlled by the stabilization module sequence valve itself.

In concrete terms, the pressure that is built up in a control line by the pilot control valve is not applied directly to the stabilization module connection valve or its one control side. Rather, the working fluid in the control line is first routed through an additional internal valve (with throttle function) of the stabilization module sequence valve. The configuration of this internal valve that is preferred according to the invention restricts the flow of working fluid from the control line to the one control side of the stabilization module connection valve. As a result, the stabilization module sequence valve switches/changes only slowly from its basic position (in which the connections between the pressure accumulator and consumers are blocked) to its working position (in which these connections are established). Due to the slow switching/changing from the basic (end) position to the working (end) position, the opening/opening cross-section between the pressure accumulator line and the pressure line in the stabilization module sequence valve acting in the load-lifting direction of the consumer is over only slightly/slowly increasing over a longer period of time. As a result, the mutually possibly different pressures in the pressure accumulator line and the pressure line acting in the load-lifting direction adapt slowly, or there are no pressure peaks as a result of switching over/alternating. As a result, the shovel of the wheel loader moves only slowly and not abruptly during the switchover/changeover from pump operation to storage operation, which the operator does not notice, or at least does not notice in a disturbing manner.

The present invention can also dispense with the shut-off valve between the pressure accumulator line and the tank line mentioned in the prior art.

As discussed above, the purpose of the prior art shut-off valve is to vent to tank increased pressure in the accumulator line of the stabilization module that is causing undesired vane movement. In the present invention, on the other hand, the shut-off valve can be dispensed with, since the design of the internal valve means that the stabilization module connection valve switches over/changes over so slowly that no disruptive pressure peaks occur when switching over.

In a preferred embodiment of the stabilization module according to the invention, the stabilization module connection valve is therefore designed in such a way that the control of the connection between the control side of the stabilization module connection valve with the pilot valve results in a predetermined or adjustable slowed down or braked connection between the pressure lines with the pressure accumulator line and the tank line causes, as has already been indicated above.

In other words, the stabilization module sequence valve switches/changes over so slowly between the basic position, possibly a middle position and the working position, that the connection between the pressure lines and the pressure accumulator line or the tank line is only established at a slower rate. As a result, the pressures in the respective lines can slowly adapt to each other and there are no pressure peaks.

In a preferred embodiment of the stabilization module according to the invention, the pressure of the pressure accumulator line and the pressure in the pressure line acting in the load-lifting direction are slowly equalized before the stabilization module switch-on valve completely switches/changes to its working position. This will prevent pressure spikes in one of the lines when the lines are connected. Due to the slow switching/changing of the stabilization module sequence valve, the respective line pressures have enough time to slowly adjust. By avoiding pressure peaks, unwanted surprising blade movements are prevented.

In a preferred embodiment of the stabilization module according to the invention, the stabilization module connection valve is a spring-loaded 7/3 switching valve. In the basic position, the stabilization module sequence valve hydraulically connects the control side of the stabilization module sequence valve with the pilot valve and a pump line with the pressure accumulator line and separates the connections between the pressure accumulator line with the pressure line acting in the load-lifting direction of the consumer and between the tank line the pressure line acting in the load lowering direction.

In a preferred embodiment of the stabilization module according to the invention, the stabilization module connection valve connects the control side of the stabilization module connection valve to the pilot valve and the connections between the pressure accumulator line to the pressure line acting in the load-lifting direction of the consumer and between the tank line to the load line in a middle position -Pressure line acting in the lowering direction is hydraulically throttled and separates the connection between the pump line and the pressure accumulator line.

In a preferred embodiment of the stabilization module according to the invention, the stabilization module connection valve in the working position connects the control side of the stabilization module connection valve to the pilot valve and hydraulically unthrottled the connections between the pressure accumulator line with the pressure line acting in the load-lifting direction of the consumer and between the tank line with the pressure line acting in the load lowering direction and separates the connection between the pump line and the pressure accumulator line.

In the basic position of the stabilization module sequence valve, the pressure lines and the pressure accumulator line or tank line are separated. The pressure accumulator line is preferably connected to the pump line. This allows the accumulator to be refilled.

The connection between the control side of the stabilization module connection valve and the pilot control valve allows the stabilization module connection valve to be switched/actuated, as was explained above. In the (actuated) center position, the pressure lines and the pressure accumulator line or tank line are connected in a hydraulically throttled manner. This allows the pressure in the lines to adjust slowly. The connection between the control side of the stabilization module sequence valve and the pilot valve is also hydraulically throttled. As a result, the stabilization module sequence valve switches more slowly from the middle position to the working position. In the working position, the pressure lines and the pressure accumulator line or tank line are connected hydraulically without being throttled. The pressure accumulator with air chamber serves as a damper/stabilization module.

In a preferred embodiment of the stabilization module according to the invention, the internal valve is arranged in a main slide/valve piston of the stabilization module sequence valve and establishes the connection between one end face of the main slide (control side of the sequence valve) and the control line. A working fluid flow between the control side of the stabilization module sequence valve and the pilot control valve is throttled by the internal valve in the stabilization module sequence valve. This means that the flow of working fluid that switches/actuates the stabilization module sequence valve from the basic position is throttled by the internal valve. As a result, the stabilization module sequence valve switches/changes more slowly from the basic position to the working position.

In a preferred embodiment of the stabilization module according to the invention, the main slide of the stabilization module sequence valve has an axial bore on one end face, in which a combined throttle check valve with a valve body and a valve seat is arranged. The one-way flow control valve is the internal valve. The axial bore establishes a connection between the pilot valve and the front side of the main spool and thus to the control side of the stabilization module sequence valve. The valve body or the valve seat of the internal valve has a lateral notch extending in the working fluid flow direction (valve longitudinal direction), through which working fluid can flow in a closing direction of the throttle check valve. The throttle check valve thus enables a low volume flow of working fluid in the closing direction, even when the valve body is seated on the valve seat. This indentation makes it possible for the working fluid in the control line to flow in a throttled manner to the control side of the stabilization module sequence valve (as a result of the narrow cross-section of the indentation). The notch acts as a throttle and throttles the flow of working fluid from the pilot valve to the control side of the stabilization module sequence valve.

In other words, the internal valve of the stabilization module connection valve is a kind of throttle valve, in particular a throttle check valve (i.e. a throttle valve with an additional check function). The combined one-way flow control valve is constructed in such a way that, when it is closed, it allows a small amount of flow towards the control side of the sequence valve. In the open state, on the other hand, it does not or only slightly throttle the working fluid flowing through from the control side of the sequence valve.

In other words, the one-way flow control valve has a valve body that is preloaded onto a valve seat with a preferably additional throttle point that is upstream in relation to the control side of the sequence valve and that acts in principle, with the valve body or the valve seat having a notch as a further throttle point that acts depending on the direction of flow, through which a working fluid residual flow can flow in the closed state of the throttle check valve.

When the stabilization module sequence valve switches from the working position back to the basic position, working fluid flows from the front side of the main spool through the throttle check valve to the control line connection. In this direction, the one-way flow control valve has a (significantly) lower flow resistance than in the closing direction, since the notch has no effect due to the valve body being lifted from the valve seat and only the upstream throttle retains its function. This switches/changes the stabilization module sequence valve from the working position to the basic position faster than the other way around.

In a preferred embodiment of the stabilization module according to the invention, the valve body has the notch. The indentation allows working fluid to flow through the combined throttle/return valve in the closing direction of the valve. The notch creates a high flow resistance. So only a small volume flow of working fluid can flow in the closing direction. Due to the high flow resistance, the working fluid can only flow slowly to the front side of the main slide and the stabilization module sequence valve is switched over only slowly.

In a preferred embodiment of the stabilization module according to the invention, the piston stroke speed of the main slide is higher in an initial phase of a switchover/changeover process of the stabilization module connection valve from the basic position to the working position than in a middle phase of the switchover process. Structurally, this can be achieved in that in the initial phase, i.e. in an initial displacement range of the main spool, the control side of the stabilization module sequence valve (basically) from the working fluid flowing through the notch of the valve body, and additionally (temporarily) another fluid flow of working fluid is acted upon from the control line, which can reach the control side of the sequence valve through a (circumferential) gap between the main slide and a switching valve housing. As a result, the main slide moves faster in the initial phase than in a middle phase, i.e. until preferably a control edge on the main slide closes this (circumferential) gap formed on the radial outside of the main slide in the axial direction on reaching a middle position/middle phase. Faster movement in the initial phase is less critical than fast movement in the middle phase.

Due to the faster movement in the initial phase, it is possible to switch more quickly between the basic and working positions of the stabilization module sequence valve. The large diameter sections of the main spool that cover/block the line ports are longer than the line ports are wide. This moves the main spool a certain distance without affecting the opening state of the ports. In other words, the main slide can move a certain distance without switching to another position. This distance corresponds to the distance that the main slide is moved during the initial phase and can therefore be bridged with a higher piston speed.

In a preferred embodiment of the stabilization module according to the invention, an additional volume flow of the working fluid is added to the indentation flow in the initial phase of the switching process of the stabilization module connection valve. In order to generate the rapid movement explained above, an additional fluid flow is generated in the initial phase, as explained above. The additional fluid flow is caused by the working fluid being able to flow past the main spool. In concrete terms, a diameter of a main slide receiving bore of the valve housing is larger than the diameter of the main slide in a defined axial section, as a result of which the aforementioned flow gap arises. In this axial section, therefore, working fluid can flow past the outside/circumferential side of the main slide. When a control edge on the main spool/main piston reaches a control edge on the valve housing for a specific piston stroke, the control edges close the circumferential gap in the axial direction. No working fluid can then flow past the main slide and the piston stroke speed is reduced.

In a preferred embodiment of the stabilization module according to the invention, the piston stroke speed of the main slide is higher in an end phase of the switchover process of the stabilization module sequence valve than in the middle of the switchover process. This means that in the end phase of the piston stroke, the main slide moves faster again than in the middle phase. Similar to what was described above, there is also a certain distance/piston stroke in the final phase that the main spool can travel without switching to another position. This distance can be covered with a higher piston stroke speed in order to shorten the overall switching time. This means that the piston stroke speed is lowest in the middle phase. The middle phase is the most critical as this is the phase in which line fittings are actually hydraulically connected.

In a preferred embodiment of the stabilization module according to the invention, an additional volume flow of the working fluid is switched on in the final phase of the switching process of the stabilization module connection valve, similar to the initial phase. The additional volume flow is generated by working fluid being able to flow past the main slide through a further circumferential milling and thereby acting on one control side of the stabilization module connection valve in addition to the volume flow through the check valve. This will move the main spool in faster again in the final phase of the switching process than in the middle phase.

In a preferred embodiment of the stabilization module according to the invention, the additional volume flow in the initial and/or final phase is greater than the continuous volume flow through the notch. Because the gap between the main spool and the main spool receiving bore in the valve body is larger than the cross section of the notch, the flow past the main spool is greater than the flow through the notch.

character list

• 1 zeigt einen hydraulischen Schaltplan des erfindungsgemäßen Stabilisierungsmoduls;
• 2 zeigt einen Längsschnitt durch einen Hauptschieber eines Stabilisierungsmodul-Zuschaltventils in einer Grundstellung;
• 3 zeigt einen Ausschnitt des Längsschnitts in 2 mit einem internen Ventil, das in dem Hauptschieber positioniert ist;
• 4 zeigt einen inneren Ventilkörper des Stabilisierungsmodul-Zuschaltventils;
• 5 zeigt einen Längsschnitt durch den Hauptschieber in einer Arbeitsstellung;
• 6a zeigt ein Zeit-Druck-Diagramm mit einem ersten Szenario;
• 6b zeigt ein Zeit-Druck-Diagramm mit einem zweiten Szenario;
• 7 zeigt eine Unterseite des Stabilisierungsmoduls;
• 8 zeigt eine Oberseite des Stabilisierungsmoduls;
• 9 zeigt eine weitere Ansicht des Stabilisierungsmoduls;
• 10 zeigt das Stabilisierungsmodul mit einer Adapterplatte;
• 11 zeigt eine Draufsicht auf das Stabilisierungsmodul mit der Adapterplatte; und
• 12 zeigt eine Schnittansicht durch ein Füllventil des Stabilisierungsmoduls.

The invention is explained in more detail below using a preferred exemplary embodiment with reference to the accompanying figures.

• 1 shows a hydraulic circuit diagram of the stabilization module according to the invention;
• 2 shows a longitudinal section through a main slide of a stabilization module connection valve in a basic position;
• 3 shows a section of the longitudinal section in 2 with an internal valve positioned in the main spool;
• 4 shows an inner valve body of the stabilization module sequence valve;
• 5 shows a longitudinal section through the main slide in a working position;
• 6a shows a time-pressure diagram with a first scenario;
• 6b shows a time-pressure diagram with a second scenario;
• 7 shows an underside of the stabilization module;
• 8th shows a top of the stabilization module;
• 9 shows another view of the stabilization module;
• 10 shows the stabilization module with an adapter plate;
• 11 shows a plan view of the stabilization module with the adapter plate; and
• 12 shows a sectional view through a filling valve of the stabilization module.

Detailed description of the invention

1 shows a hydraulic circuit diagram of the stabilization module 1 according to the invention. The basic operation of the circuit diagram is from FIG DE 10 2018 210 471 B3 famous. Therefore, a detailed description of components or groups that are identical to the prior art is omitted.

Accordingly, a cylinder 4 first has a cylinder space that acts in a load-raising direction and a cylinder space that acts in a load-lowering direction. The load is preferably a shovel (not shown) of a mobile work machine, in particular a wheel loader. The cylinder chamber, which acts in the load-lifting direction, is connected to a pressure line 6, which acts in the load-lifting direction. The cylinder chamber, which acts in the load-lowering direction, is connected to a pressure line 8, which acts in the load-lowering direction, the line pressures of which can be controlled in a manner not shown in detail such that the load can be selectively raised or lowered.

The pressure lines 6, 8 are also connected to a stabilization module sequence valve 2 according to the present invention. In the present case, the stabilization module sequence valve 2 is a 7/3-way valve with three inputs and four outputs. The pressure lines 6.8 are each connected to an output. A control line 10 , a pressure accumulator line 12 and a tank line 18 are connected to the inputs of the stabilization module sequence valve 2 . The control line 10 is connected to a pilot valve 16 , the pressure accumulator line 12 is connected to a pressure accumulator 14 and the tank line 18 is connected to a tank 20 . A pump line 28 and a control line 24 on the control side are connected to the other outputs of the stabilization module connection valve 2 . The control line 24 on the control side is connected to a control side of the stabilization module connection valve 2 and the pump line 28 is connected to a pump 5 .

In a spring-biased basic position of the stabilization module sequence valve 2 (see 1 ) the pressure lines 6, 8 or the corresponding outlets are shut off by a valve piston/valve slide of the stabilization module connection valve 2. In contrast, the pump line 28 is hydraulically connected to the pressure accumulator line 12 and the control line 10 is connected to the control line 24 on the control side. In a middle position of the stabilization module connection valve 2, the connection to the pump line 28 is blocked. In contrast, the pressure line 6 acting in the load-lifting direction is connected in a hydraulically throttled manner to the pressure accumulator line 12 in the middle position, and the pressure line 8 acting in the load-lowering direction is connected to the tank line 18 in a hydraulically throttled manner. The control line 10 is also hydraulically throttled connected to the control-side control line 24. Finally, in a working (end) position of the stabilization module sequence valve 2, the pressure line 6 acting in the load lifting direction is connected to the pressure accumulator line 12, the pressure line 8 acting in the load lowering direction is connected to the tank line 18 and the control line 10 is connected to the control line on the control side. The connection to the pump line 28, however, is blocked.

The stabilization module sequence valve 2 is switched from the basic position to the central and working position by increasing a control pressure in the control line 10 .

The pilot valve 16 is presently a 3/2-way valve and is connected on the output side via the control line 10 to the stabilization module connection valve 2 at its one input connection. In a spring-biased basic position of the pilot valve 16, a connection/passageway to the accumulator line 12 is blocked. The control line 10 is also relieved via the tank line 18 . In a working position of the pilot valve 16, which is activated by an electric actuator, the control line 10 is connected to the pressure accumulator line 12, in which a pressure accumulator line pressure from the pressure accumulator 14 is always present.

A continuously adjustable inlet pressure compensator 30 and a throttle 32 are arranged in the pump line 28 between the pump 5 and the connection of the stabilization module connection valve 2 . The inlet pressure compensator 30 is designed as a 3/3-way valve. In a spring-biased basic position of the inlet pressure compensator 30, the pump line 28 is blocked and the inlet pressure compensator 30 acts as a load-holding valve. In a middle position, connections of the pump line 28 are connected, i.e. the pump line 28 is open. The input pressure compensator 30 can be switched by a pressure in a control line 36 in which a throttle 38 is used. This control line 36 branches off from the pump line 28 downstream of the inlet pressure compensator 30 and downstream of the throttle 32 . The inlet pressure compensator 30 and the throttle 32 thus form a 2-way flow regulator.

A check valve 34 is also arranged in the pump line 28 between the throttle 32 and the connection of the stabilization module connection valve 2 , the opening direction of which is directed towards the stabilization module connection valve 2 and thus towards the pressure accumulator 14 .

The control pressure in the control line 36 acting towards the blocking position (basic position) of the input pressure compensator 30 is limited via an adjustable pressure-limiting valve 42 . The pressure-limiting valve 42 is connected to the tank line 18 on the outlet side. The pressure relief valve 42 is an accumulator boost pressure relief.

A further pressure limiting valve 40 is arranged between the pressure accumulator line 12 and the tank line 18 and limits a pressure in the pressure accumulator line 12 .

2 shows a longitudinal section of a valve piston/main slide 48 of the stabilization module connection valve 2 in the basic position (construction position). Ie the structural design of the stabilization module connection valve 2 is described below.

The main slide 48 is arranged in an axially displaceable manner in a main slide receiving bore 50 of a valve housing 52 . The main spool 48 is presently an elongated/cylindrical piston having three large diameter axial sections. The three large-diameter axial sections are axially connected by intermediate small-diameter axial sections. Only in the large diameter sections is there a very small gap between the main spool 48 and the main spool receiving bore 50 . The main slide receiving bore 50 is closed axially on an end face of the valve housing 52 by a screw plug (blind plug) 56 . In the basic position according to the 2 the main slide 48 is pressed by a spring 54 in the direction towards the locking screw 56 . That is, the main slide 48 is preloaded by the spring 54 .

• - Ein Tankanschluss 58 ist mit der Tankleitung 18 verbunden.
• - Ein in Last-Heberichtung wirkender Zylinderanschluss 60 ist mit der in Last-Heberichtung wirkenden Druckleitung 6 verbunden.
• - Der Druckspeicheranschluss 62 ist mit der Druckspeicher-Leitung 12 verbunden.
• - Ein Druckwaageanschluss 64 ist mit der Pumpenleitung 28 zur Eingangsdruckwaage 30 verbunden.
• - Ein Pumpenanschluss 66 ist mit der Pumpenleitung 28 verbunden.
• - Ein in Last-Absenkrichtung wirkender Zylinderanschluss 68 ist mit der in Last-Absenkrichtung wirkenden Druckleitung 8 verbunden.
• - Ein weiterer Tankanschluss 70 ist ebenfalls mit der Tankleitung 18 verbunden.
• - Ein Steueranschluss 72 ist mit der Steuerleitung 10 verbunden.

The valve housing 52 has a number of connections to various lines, as has already been explained above. At each line connection, the valve housing 52 has a circumferential recess/groove on the inside in the bore 50 . These circumferential recesses form control edges. The line connections are arranged as follows in a sequence from the side of the spring 54 to the screw plug 56:

• - A tank connection 58 is connected to the tank line 18 .
• A cylinder connection 60 acting in the load-lifting direction is connected to the pressure line 6 acting in the load-lifting direction.
• - The accumulator port 62 is connected to the accumulator line 12.
• - A pressure compensator connection 64 is connected to the pump line 28 to the inlet pressure compensator 30.
• - A pump connection 66 is connected to the pump line 28 .
• A cylinder connection 68 acting in the load-lowering direction is connected to the pressure line 8 acting in the load-lowering direction.
• - Another tank connection 70 is also connected to the tank line 18 .
• - A control connection 72 is connected to the control line 10 .

Since there is no gap or only a very small gap between the main spool 48 and the main spool receiving bore 50 in the axial large-diameter sections, the line connections are hydraulically blocked/locked when a large-diameter section of the main spool 48 before/over positioned at a port.

In the basic position of the stabilization module connection valve 2, the tank connection 58 is open. The cylinder connection 60 acting in the load-lifting direction is covered by the main slide 48 and is therefore closed. The accumulator port 62 and the pressure compensator port 64 are connected to one another. That is, in the basic position, working fluid can flow from the pump line 28 to the accumulator line and vice versa. The pump connection 66 is blocked, and the cylinder connection 68 acting in the load-lowering direction is also blocked. The other tank connection 70 is open. The connection from control port 72 to the control side of the main slide is open in the basic position.

3 shows a front section of the main slide 48 2 in detail. As described above, the valve housing 52 has a peripheral recess 73 with a control edge at the control connection 72 . The main slide 48 has an axially extending milling 76 at an axial end portion with a large diameter, which is closer to the plug screw 56 . Milling 76 is thus an elongated recess in main spool 48 and is positioned near face 74 of main spool 48 but is spaced from face 74 . The milling 76 is positioned in the circumferential direction on the side of the main slide 48 which is opposite the control line connection 72 . In the basic position, the milling 76 is hydraulically connected to the recess 73 of the control connection 72 .

The main slide 48 also has a central axial bore 80 on its end face 74 . The milling 76 and the axial bore 80 are connected by a radially extending channel 78 which is formed in the main spool 48 . A spool internal valve 11 having a valve body 82 and a valve seat 84 is positioned within the axial bore 80 .

The valve body 82 is preferably an elongated cone tapering to a point on one axial side. The valve body 82 is seated on the valve seat 84 in an axially movable manner. In the present case, the valve seat 84 is formed by a screw insert/grub screw which is screwed into the axial bore 80 and which has an axial through bore. The combination of the valve seat 84 and the valve body 82 forms a combined throttle check valve. The one-way flow control valve has its opening direction in a flow direction away from the end face 74 towards the milling 76. The main slide 48 has a second milling 86 which, viewed in the circumferential direction, is opposite the first milling 76 and is formed/axially opened on the end face 74 is. This means that the second milling 86 does not form a control edge on the end face 74 of the main slide 48.

In addition to the cutouts at the line connections 58 - 72 , the valve housing 52 also has a further circumferential cutout 88 . The diameter of the main slide receiving bore 50 is larger on a front side of the recess 88 than on a spring-side side of the recess 88. Due to the larger diameter of the main slide receiving bore 50, a gap forms on this axial section between the main slide 48 and the main slide Locating bore 50. With the smaller diameter, no gap is formed between the main spool 48 and that of the main spool locating bore 50.

4 12 shows the valve body 82 of the internal valve 11. The valve body 82 is essentially an elongate cone, the peripheral wall of which converges to a point at one end. In the longitudinal direction, two opposite peripheral sections are milled to form a plane and thus form two plane-parallel surfaces 92. The two plane surfaces 92 are connected by a transverse bore 94 through the valve body 82 transversely to the longitudinal direction of the valve body 82. The transverse bore 94 is positioned approximately in the axial center of the valve body 82 . On the axial side, which does not converge (i.e. is cylindrical), the valve body 82 has a central longitudinal bore 96 (in 3 visible) on. The longitudinal bore 96 runs along the central axis of the valve body 82 and opens into the transverse bore 94. Finally, the valve body 82 has an outer longitudinal notch 98. The notch 98 extends from the conically pointed end face of the valve body 82 in the longitudinal direction to the phase end, ie to that axial section of the valve body 82 in which the conical shape changes into the cylindrical shape. The notch 98 is formed on/in the axial extension of one of the planar surfaces 92 as seen in the circumferential direction. The notch 98 has a smaller cross-section than the longitudinal bore 73 .

5 shows a longitudinal section of the entire main slide 48 in the working position. In the working position, the main slide 48 is completely displaced in the direction towards the spring 54 and the spring 54 is therefore completely compressed. In the working position, the tank connection 58 is covered by the main slide 48. The cylinder port 60 acting in the load-lifting direction is connected to the accumulator port 62 . The pressure compensator connection 64 and the pump connection 66 are blocked. The cylinder port 68 acting in the load lowering direction is connected to the tank port 70 . The control port 72 is open. The connections between the cylinder ports 60, 68 with the pressure accumulator port 62 and the tank port 70 are realized in that the respective line ports are located on a section with a small diameter of the main slide 48 in such a way that the respective line ports are not blocked/obstructed/covered and working fluid can flow from one line connection to the adjacent one.

• In einem Pumpenbetrieb des Radladers wird die Radlader-Schaufel (nicht dargestellt) von der Pumpe 5 wahlweise angehoben bzw. gesenkt. Diese Betätigung zählt zum bekannten Stand der Technik und ist vorliegend nicht weiterdargestellt.
• In einem Speicherbetrieb werden die Schaufelzylinder mit dem Stabilisierungsmodul 1 aufweisend zumindest das Stabilisierungs-Zuschaltventil 2 mit Vorsteuerventil 16 und den Druckspeicher 14 und vorzugsweise das Ventil 30 sowie die genannten Drosseln 32, 38 und Druckbegrenzungsventils 40, 42, verbunden, das unerwünschte Schaufelbewegungen dämpft. Dazu wird das Stabilisierungsmodul 1 folgendermaßen geschaltet:
  • Das Vorsteuerventil 16 wird durch elektrische Betätigung des Aktors in seine Arbeitsstellung geschaltet. Dadurch wird die Steuerleitung 10 mit dem Druck aus der Druckspeicher-Leitung 12 (und dem Druckspeicher 14) beaufschlagt. Das Stabilisierungsmodul-Zuschaltventil 2 wird durch den Druck in der Steuerleitung 10 bzw. durch einen Arbeitsfluidstrom in der Steuerleitung 10 geschaltet/betätigt.

The hydraulic design described above works as follows:

• When the wheel loader is in pump mode, the wheel loader shovel (not shown) is selectively raised or lowered by the pump 5 . This actuation is part of the known prior art and is not presented in any more detail here.
• In storage operation, the shovel cylinders are connected to the stabilization module 1, which has at least the stabilization connection valve 2 with the pilot valve 16 and the pressure accumulator 14 and preferably the valve 30 and the throttles 32, 38 and the pressure-limiting valve 40, 42 mentioned, which dampen unwanted shovel movements. For this purpose, the stabilization module 1 is switched as follows:
  • The pilot valve 16 is switched into its working position by electrical actuation of the actuator. As a result, the pressure from the pressure accumulator line 12 (and the pressure accumulator 14) is applied to the control line 10 . The stabilization module sequence valve 2 is switched/actuated by the pressure in the control line 10 or by a flow of working fluid in the control line 10 .

Since control line 10 (or control line section 22 between pilot control valve 16 and sequence valve 2) and control line 24 on the control side are hydraulically connected when stabilization module sequence valve 2 is in the basic position, working fluid can flow from control line 10 to the control side of stabilization module sequence valve 2. The working fluid first switches the stabilization module sequence valve 2 to the central position and then to the working position. Since the connection between the control line 10 and the control line 24 on the control side is hydraulically throttled in the center position, the stabilization module connection valve 2 switches to the working position only slowly. The pressure line 6 acting in the load-lifting direction is hydraulically throttled in the central position and connected to the pressure accumulator line 12 . The pressure line 8 acting in the load lowering direction is connected to the tank line 18 in a hydraulically throttled manner. In the working position, the pressure lines 6, 8 are connected to the pressure accumulator line 12 and the tank line 18, respectively. In the working position, the cylinder acting in the load-lifting direction is connected via the corresponding pressure line 6 and to the pressure accumulator line 12 and thus to the pressure accumulator 14 . Since an air chamber is formed in the pressure accumulator 14, the pressure accumulator 14, together with the hydraulic circuit described above, forms a damped hoist suspension.

• Das Arbeitsfluid strömt demnach aus der Steuerleitung 10 durch den Steueranschluss 72 in die Aussparung 73. Die Aussparung 73 ist mit der Fräsung 76 verbunden. Durch den in die Fräsung 76 sich öffnenden, radial im Hauptschieber 48 sich erstreckenden Kanal 78 fließt Arbeitsfluid in die Axialbohrung 80 und zum internen Ventil 11. Damit fließt Arbeitsfluid in Schließrichtung des internen Ventils 11. Durch die Einkerbung 98 des Ventilkörpers 82 kann jedoch ein geringer Volumenstrom an Arbeitsfluid entgegen der Schließrichtung des internen Ventils 11 zur Stirnseite 74 des Hauptschiebers 48 fließen. Der kleine Querschnitt der Einkerbung 98 drosselt dabei den Arbeitsfluidstrom zur Stirnseite 74. Die Einkerbung 98 weist folglich einen hohen Strömungswiderstand auf. Dadurch erhält das interne Ventil 11 die Funktion eines kombiniertes Drossel-Rückschlagventil, wie dies vorstehend erwähnt wurde.

The throttling of the working fluid between the control line 10 and the control side of the stabilization module sequence valve 2 results from the structural design of the main slide 48 in 3 :

• The working fluid accordingly flows out of the control line 10 through the control connection 72 into the recess 73. The recess 73 is connected to the milling 76. Working fluid flows through the channel 78, which opens into the milling 76 and extends radially in the main slide 48, into the axial bore 80 and to the internal valve 11. Working fluid thus flows in the closing direction of the internal valve 11. However, due to the notch 98 of the valve body 82, a smaller Flow of working fluid against the closing direction of the internal valve 11 to the end face 74 of the main slide 48 flow. The small cross section of the notch 98 throttles the flow of working fluid to the end face 74. The notch 98 consequently has a high flow resistance. This gives the internal valve 11 the function of a combined throttle-check valve as mentioned above.

The working fluid now slowly collects on the end face 74 of the main slide 48 and pushes the main slide 48 against the direction of the Spring force of the spring 54 toward the spring side. As a result, the main slide 48 of the stabilization module connection valve 2 is slowly pushed into the working position. As a result of the movement of the main slide 48, the line connections are released or covered by the main slide 48 in accordance with the above description. The movement of the main slide 48 therefore causes the stabilization module connection valve 2 to be switched/changed from the basic position via the central position to the working position.

As described above, in the working position, the pressure line 6 acting in the load lifting direction is connected to the pressure accumulator line 12 and the pressure line 8 acting in the load lowering direction is connected to the tank line 18 . These connections are established by the piston movement of the main spool 48.

The working fluid flow through the notch 98 is constant throughout the piston movement of the main spool 48 . This would mean that the speed of movement of the main slide would remain essentially the same throughout its slide travel. In addition to this (constant) volume flow, there is another (temporary/time-dependent) (secondary) volume flow. In an initial phase of the piston movement, the front control edge of the milling 76 is closer to the screw plug 56 or the control side of the main slide 48 than the recess 88. On the front side of the recess 88 is the gap between the main slide 48 and the main slide receiving bore 50 present. Working fluid can therefore flow from the milling 76 through the gap on the main slide 48 to the end face 74 . Due to this additional volume flow, the main slide 48 moves faster in the initial phase than in a middle phase. This means that the piston stroke speed is greater in the initial phase than in the middle phase. The additional volume flow breaks off when/as soon as the front edge of the milling 76 has passed the spring-side control edge of the recess 88 (reaching the middle phase).

Also in an end phase of the main slide movement, an additional (temporary/time-dependent) volume flow occurs in addition to the (constant) volume flow through the notch 98. If the control edge 87 of the second milling 86 passes the front control edge of the recess 73, working fluid can flow from the control connection 72 directly to the front side 74 of the main slide 48 flow (reaching the end phase). Due to the additional flow of working fluid, the main slide movement is also accelerated in the end phase of the movement. This means that the piston stroke speed is also greater in the end phase than in the middle phase.

When the stabilization module sequence valve 2 is switched from the working position to the basic position, the pressure in the control line 10 is reduced or relieved into the tank line by the pilot control valve 16 . The main slide 48, which is preloaded by the spring 54, presses in the direction of the screw plug 56. The working fluid flows from the end face 74 via the axial bore 80 with the internal valve 11 and the channel 78 to the control port 72. The working fluid flows in the opening direction of the internal valve 11 The flow of working fluid is also throttled in the opening direction by the transverse and longitudinal bores 94, 96. In this case, the transverse and longitudinal bores 94, 96 have a larger cross section than the notch 98 and thus a lower flow resistance.

• Da das Arbeitsfluid auf dem Weg von der Steuerleitung 10 zur Steuerseite des Stabilisierungsmodul-Zuschaltventils 2 gedrosselt wird, wird das Stabilisierungsmodul-Zuschaltventil 2 nur verlangsamt geschaltet bzw. der Hauptschieber 48 bewegt sich nur langsam von seiner Grundstellung in seine Arbeitsstellung. Dadurch werden die Verbindungen zwischen der in Last-Heberichtung wirkenden Druckleitung 6 mit der Druckspeicher-Leitung 12 und der in Last-Absenkrichtung wirkenden Druckleitung 8 mit der Tankleitung 18 nur langsam hergestellt. Die langsame Kolbenhubbewegung des Hauptschiebers 48 bewirkt also, dass die Verbindungen zwischen den Druckleitungen 6, 8 und der Druckspeicher-Leitung 12 bzw. der Tankleitung 18 nicht schlagartig hergestellt werden, sondern über eine bestimmte Zeitdauer. Dadurch entsteht zwischen der Grund(-end)-stellung des Hauptschiebers 48 und damit des Stabilisierungsmodul-Zuschaltventils 2 und der Arbeits(-end)-stellung die Mittelstellung, in der die Druckleitungsanschlüsse 60, 68 noch nicht vollständig geöffnet und damit hydraulisch gedrosselt sind. In der Mittelstellung passen sich die jeweiligen Drücke in den Druckleitungen 6, 8 und der Druckspeicher-Leitung 12 bzw. Tankleitung 18 aneinander an. Da sich die Drücke in den jeweiligen Leitungen aneinander anpassen können, wird verhindert, dass es Druckdifferenzen in den Druckleitungen beim Umschalten vom Pumpenbetrieb in den Speicherbetrieb gibt. Dadurch wird ein Stabilisierungsmodul 1 bereitgestellt, dass keine übermäßige Schaufelbewegung beim Zu- und Abschalten des Stabilisierungsmoduls/ der Hubwerksfederung zulässt.

The functionality described above results from the structural design and has the following effects/advantages:

• Since the working fluid is throttled on the way from the control line 10 to the control side of the stabilization module connection valve 2, the stabilization module connection valve 2 is only switched slowly or the main slide 48 moves only slowly from its basic position to its working position. As a result, the connections between the pressure line 6 acting in the load lifting direction and the pressure accumulator line 12 and the pressure line 8 acting in the load lowering direction and the tank line 18 are made only slowly. The slow piston stroke movement of the main slide 48 has the effect that the connections between the pressure lines 6, 8 and the pressure accumulator line 12 or the tank line 18 are not made suddenly, but over a certain period of time. This creates the middle position between the basic (end) position of the main slide 48 and thus of the stabilization module sequence valve 2 and the working (end) position, in which the pressure line connections 60, 68 are not yet fully open and are therefore hydraulically throttled. In the middle position, the respective pressures in the pressure lines 6, 8 and the pressure accumulator line 12 or tank line 18 adapt to one another. Since the pressures in the respective lines can adapt to one another, pressure differences in the pressure lines when switching from pump operation to storage operation are prevented. This provides a stabilization module 1 that does not allow excessive blade movement when the stabilization module/lift mechanism suspension is switched on and off.

The different piston stroke speeds in the beginning, end and middle phase of the Piston strokes have the following reason. As in 2 As can be seen clearly, the sections with a large diameter of the main slide 48 have a greater axial extent than the recesses on the line connections 58 - 72. This means that the main slide 48 has to move a relatively large distance before the line connections 58 - 72 are released or covered . In the initial and final phases of the piston stroke, the main slide 48 thus moves a certain distance without bringing line connections into fluid contact, ie without switching between valve positions. This section is not relevant for the pressure adjustment in the lines. The piston stroke speed in these phases can therefore be faster than the piston stroke speed in the middle phase, in which the valve is actually switched or the pressure adjustment takes place.

Since the internal valve 11 has a lower flow resistance in its opening direction than in the closing direction, the stabilizing module connection valve 2 switches more quickly from its working position to the normal position than in the other direction. This is not critical insofar as most of the excessive (blade) movements or pressure differences occur when the stabilization module 1 is switched on.

6a shows a time-pressure diagram in a first scenario. The pressure accumulator line pressure p _X2 is higher than the pressure p _H in the pressure line 6 acting in the load-lifting direction. 6b shows a time-pressure diagram in a second scenario. In the second scenario, the pressure p _H in the pressure line 6 acting in the load-lifting direction is greater than the pressure accumulator line pressure p _X2 . In both scenarios there is a point in time at which there is a switchover from one operating state to the other. It is clear that the pressure accumulator line pressure P _X2 and the pressure in the pressure line 6 adjust to a pressure p _END in a time window t. The adjustment of the pressures is possible through the slow switching over of the stabilization module connection valve 2 as described above. Pressure peaks are avoided by the slow pressure equalization in the period t.

7 1 shows a view of the stabilization module 1. The stabilization module 1 has the valve housing 52 with a number of connections and a plate 100 for connecting an adapter 102. FIG. On the plate side, the valve housing 52 has the cylinder port 68 acting in the load-lowering direction, the pump port 66, the cylinder port 60 acting in the load-raising direction, and the tank ports 58, 70. Furthermore, the valve housing 52 has the check valve 34 in the pump line 28 and the throttle 38 .

On one side of the valve housing 52, the valve housing 52 has the pressure accumulator port 62, the cylinder port 68 acting in the load-lowering direction, and the cylinder port 60 acting in the load-raising direction. The valve housing 52 has the pilot valve 16 on the end face. On the opposite side of the pilot valve 16, the valve housing 52 has the pressure-limiting valve 42 for limiting the accumulator charging pressure.

8th shows another view of the stabilization module 1. On the side of the pressure relief valve 48, the valve housing 52 has the stabilization module connection valve 2 and the pressure relief valve 40 for maximum pressure limitation.

9 shows another view of the stabilization module 1. The valve housing 52 has the inlet pressure compensator 30 and a throttle 32 for accumulator charging flow limitation.

10 shows the stabilization module 1 with the adapter plate 102. The adapter plate 102 is attached to the connection plate 100. The adapter plate 102 is cuboid and has lines that are connected to the connections 58 , 60 , 62 , 64 , 66 , 68 , 70 , 72 of the stabilization module 1 . The pump and tank lines 18, 28 are connected to the stabilization module 1 through the adapter plate.

11 shows another view of the stabilization module 1 with the adapter plate 102.

12 shows a longitudinal section through the inlet pressure compensator 30 in a spring-loaded basic position. In the basic position, a connection to the pump line 103 on the main valve side is closed. The pump-side connection 105 has a connection to the control side of the inlet pressure compensator 30. In the basic position, working fluid can flow from the pump-side connection 105 through an axial bore 106 in a valve slide 104 to an end face of the valve slide 104. The pressure that is thereby applied to the end face pushes the valve spool against the spring force of spring 108 toward spring 108 . As a result, the valve spool 104 is pushed into a working position (not shown). In the working position, the two connections 103, 105 are connected. Thus, the pump line 28 is connected and working fluid can flow from the pump 5 to the stabilization module sequence valve 2 .

Claims (15)

Stabilization module (1) to stabilize the working movement of a hydraulic consumer a work machine, in particular a shovel of a wheel loader, with a stabilization module connection valve (2) hydraulically actuated by a pilot valve (16), in its working position hydraulic connections between a pressure accumulator line (12) of the stabilization module (1) with a load-lifting direction pressure line (6) acting on the consumer and between a tank line (18) with a pressure line (8) acting in the load-lowering direction, and in whose normal position these connections are separated, characterized in that a hydraulic control line (10) can be used to establish a Connection between a control side of the stabilization module connection valve (2) with the pilot valve (16) is controlled by the stabilization module connection valve (2) itself. stabilization module claim 1 , wherein the stabilization module connection valve (2) is designed in such a way that the control of the connection between the control side of the stabilization module connection valve (2) and the pilot valve (16) results in a predetermined or adjustable decelerated or braked connection between the pressure lines (6, 8) with the pressure accumulator line (12) and the tank line (18). stabilization module claim 1 or 2 , wherein the stabilization module connection valve (2) is a spring-loaded 7/3-way valve which, in the basic position, connects the control side of the stabilization module connection valve (2) to the pilot valve (16) and a pump line (28) to the pressure accumulator line (12 ) hydraulically connects and separates the connections between the pressure accumulator line (12) with the pressure line (6) acting in the load-lifting direction of the consumer and between the tank line (18) with the pressure line (8) acting in the load-lowering direction. stabilization module claim 3 , whereby the stabilization module connection valve (2) in a central position connects the control side of the stabilization module connection valve (2) with the pilot valve (16) and the connections between the pressure accumulator line (12) and the pressure line (6 ) and between the tank line (18) with the pressure line (8) acting in the load lowering direction in a hydraulically throttled manner and separates the connection between the pump line (28) and the pressure accumulator line (12). Stabilization module according to one of claims 3 or 4 , whereby the stabilization module sequence valve (2) in the working position connects the control side of the stabilization module sequence valve (2) with the pilot valve (16) and the connections between the pressure accumulator line (12) and the pressure line (6 ) and between the tank line (18) hydraulically connects to the pressure line (8) acting in the load lowering direction and separates the connection between the pump line (28) and the pressure accumulator line (12). Stabilization module according to one of Claims 1 until 5 , An internal valve (11) being arranged in a main slide (48) of the stabilization module sequence valve (2) and producing a connection between an end face (74) of the main slide (48) and the control line (10). Stabilization module (1) after claim 6 , wherein the internal valve (11) has a higher flow resistance in the closing direction than in the other direction. stabilization module claim 6 or 7 , wherein the internal valve (11) has a valve body (82) and a valve seat (84) and is positioned in an axial bore (80) in the main spool connecting the end face (74) and the control line (10). Stabilization module (1) after claim 8 , whereby the internal valve (11) is a combined throttle/non-return valve that allows a low flow rate when closed. Stabilization module (1) according to one of Claims 8 or 9 wherein the valve body (82) has an indentation (98) through which working fluid can flow. Stabilization module (1) according to one of Claims 6 until 10 , whereby the stabilization module sequence valve (2) switches more quickly from the working position to the basic position than in the opposite direction. Stabilization module (1) according to one of Claims 6 until 11 , wherein the piston stroke of the main slide (48) is faster in an initial phase of a switching process of the stabilization module connection valve (2) than in a middle phase. Stabilization module (1) according to one of Claims 10 until 12 , as far as the Claims 11 and 12 on claim 10 are related back, wherein in the initial phase of the switching process of the stabilization module connection valve (2), an additional volume flow is added to the continuous volume flow through the notch (98). Stabilization module (1) according to one of Claims 10 until 13 , as far as the Claims 11 until 13 on claim 10 are referred back, in a final phase of the switching process of Stabili mation module sequence valve (2), an additional volume flow is added to the continuous volume flow through the notch (98). Stabilization module (1) according to one of Claims 13 or 14 , wherein the additional volume flow in the initial and / or final phase is greater than the continuous volume flow through the notch (98).

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