WO2018041856A1

WO2018041856A1 - Hydraulic slewing gear drive and mobile concrete pump comprising such a slewing gear drive

Info

Publication number: WO2018041856A1
Application number: PCT/EP2017/071695
Authority: WO
Inventors: Benjamin Stegmeier; Roman Zirbs
Original assignee: Putzmeister Engineering Gmbh
Priority date: 2016-08-30
Filing date: 2017-08-30
Publication date: 2018-03-08
Also published as: EP3290386A1

Abstract

The invention relates to a slewing gear drive (14) in particular for the distribution boom (2) of a mobile concrete pump (1) and to a concrete pump (1) comprising a pivotal distribution boom (2). The slewing gear drive (14) with a hydraulic motor (15) and a friction brake (16) for securing the slewing gear drive (14) when the hydraulic motor (15) is inactive has a functional unit (25), by means of which the flow of hydraulic oil pumped through the functional unit (25) by the inactive hydraulic motor (15) is limited to a specified volumetric flow rate in the event of slipping of the friction brake (16), wherein the functional unit (25) is connected to the hydraulic motor (15) via a changeover valve (24) arranged between the two supply lines for the hydraulic motor (15). In a mobile concrete pump (1) with a distribution boom (2) which can be pivoted in the azimuth direction relative to a substructure (3) by a slewing gear (10), the slewing gear (10) comprising a slewing gear drive (14) according to the invention.

Description

HYDRAULIC ROTARY ACTUATOR AND MOBILE

Concrete pump with such a rotary actuator

The invention relates to a slewing gear drive, in particular for the placing boom of a mobile concrete pump, and to a concrete pump with a pivoting placing boom.

Work machines with a boom mounted on a substructure usually have drives and actuators for moving the boom. An example of a working machine with a corresponding boom are mobile concrete pumps, in which a boom is provided with a conveying line guided along it, through which flowable concrete can be pumped.

For a pivoting movement of the boom relative to the base of the machine a rotary drive is provided regularly, which is often a hydraulic rotary drive.

A hydraulic rotary drive comprising a hydraulic motor, the pressure is restored with ^¬ schlagtem hydraulic oil hydraulic energy can convert a rotary motion at a correspondingly controlled supply, - is converted into the desired pivotal movement ge ^¬ - optionally via a transmission. Since a corresponding hydraulic motor is always switched pressure-free at rest and thus unfolds virtually no braking effect with which the boom could be secured in a desired position, the hydraulic drive to secure the rotary drive at rest continues to include a friction brake, with the rotary drive in its respective Position can be fixed. In certain exceptional operating conditions of the working machine or by external action on the boom, for example. By wind, it may happen that the friction brake ^¬ starts to slip through. In this case, the static friction between the components of the friction brake, which is basically used to secure the boom in one position, is overcome and the components of the friction brake begin to slide against each other. As soon as the sliding begins, the braking effect of the friction brake is reduced to the sliding friction, which is generally lower than the static friction. As a result, the boom moves uncontrollably when slippage of the friction brake, from which he ^¬ considerable risks for the working machine and close to be ^¬-sensitive people result.

From WO 2009/062484 Al (document Dl) is a Hydrauliksteu- erkreis for controlling a slewing gear drive, in which is ge ^¬ transferred from the non-driven side of the hydraulic motor from the hydraulic oil passing ^¬ via a controllable throttle valve. In the normal state, the throttle valve does not exert Dros ^¬ selfunktion from that flowing through the valve but fluid can restrict, if required. To control the throttle valve or its throttle function, a pilot control is provided, which can be overwritten if necessary via a foot brake pedal. A disadvantage of this prior art is that two controllable throttle valves and an additional feedforward control are required for an automatic braking of the rotary drive. If the feedforward control fails, it is imperative that an operator be available to brake the footbrake pedal in order to brake.

The invention has for its object to provide a slewing drive and a concrete pump with a pivoting distributor boom, in which the disadvantages mentioned are reduced. This object is achieved by a slewing drive according to the main claim and a concrete pump according to the nebengeord ^¬ Neten claim 9. Advantageous further developments are the subject of the dependent claims.

Accordingly, the invention relates to a slewing drive, in particular ^¬ special for the boom of mobile concrete pumps, with a hydraulic motor and a friction brake for setting the sleuth drive in case of inactivity of the hydraulic motor, wherein the slew drive further having a functional unit with which in the event of slippage of the friction brake of the inactive switched hydraulic motor by the functional unit funded hydraulic oil flow is limited to a predetermined volume flow, wherein the functional unit is connected via a zwi ^¬ tween the two leads to the hydraulic motor arranged shuttle valve with the hydraulic motor.

The invention further relates to a concrete pump with a ge ^¬ genüber a substructure via a slewing in azimuth pivotable distribution boom, wherein the rotating mechanism comprises a rotary mill drive according to the invention.

First, some terms used in connection with the invention will be explained.

As a "mobile concrete pumps with distribution boom," all on ei ^¬ nem trucks or similar vehicles built Ma ^¬ machines for pumping flowable concrete designated by conveying lines, are performed on a distribution mast where the conveyor lines at least partially ^stabilized. In particular, han ^¬ it delt itself for mobile concrete pumps with distributor boom, ie truck-mounted concrete pumps and truck mixers with distribution mast (PUMI). As "distribution boom" Prior ^¬ direction of one or more extendible or foldable parts denoted by a conveyor line for conveying flowable concrete. The distributor mast is mounted on a "base", which forms the support structure for the distributor mast, a power-operated pivotable consisting , In order to pivot the distribution boom with respect to the Un ^¬ window construction in the azimuth direction, a "turning" is provided with the distribution mast, for example with respect to the base. By +/- 360 ° can be pivoted. In general, the rotating mechanism comprises a connected to the distribution mast , referred to as "rotation ^¬ wreath" toothed pivot bearing, engages in the toothing connected to the substructure slewing drive.

To as "case" is hereinafter referred to an extraordinary Be ^¬ operating state, act for the loads on the distri ^¬ lermast which can not be completely absorbed by the friction ^¬ brake, so that there is an undesirable movement of the placing boom. The to an overload leading loads can result in particular from acting on the distribution boom wind forces.

A hydraulic motor is "inactive" or "switched inactive" when applied causing Druckdiffe ^¬ rence between the motor connections for the hydraulic oil does not, a rotational movement of the hydraulic motor. If the shaft of the motor is rotated in an inactive hydraulic motor, the hydraulic motor will immediately act as a pump. In contrast, a Hydrau ^¬ likmotor "active" or "activated" when from a

Pressure difference resulting hydraulic energy is converted into mechanical ^¬ cal energy in the form of a rotary motion. The direction of rotation of the hydraulic motor can be selected via the direction of the applied pressure gradient. A "shuttle valve" is a valve with two inputs and egg ^¬ nem output, in which always the one input, at which the higher pressure is fluidly connected to the output, wherein an exit of the entering through the inlet in question fluid through the other input through As is known, the shuttle valve can be realized as a T-shaped shuttle valve or by means of suitable switching of two non-return valves.

The invention is based on the insight that essential co-rotates at a, resulting from an overload movement of the distributor mast about the axis of the rotating mechanism of the switched inactive Hyd ^¬ raulikmotor of the rotary actuator, whereby the hydraulic motor then conveys as a pump hydraulic oil.

By the invention is provided to limit the flow rate of the pumped by the hydraulic motor in case of overload hydraulic oil by an additional functional unit, an additional braking torque can be generated by the hydraulic motor in the slewing drive, which supports the due to the sliding friction against the static friction braking effect of the slipping friction brake , By throttling this hydraulic flow, the maximum rotational speed of the hydraulic motor in case of overload can be set, whereby the uncontrolled from the prior art, movement of a boom in case of overload can at least be limited as regards the speed of the Drehbewe ^¬ supply in the sequence. Also, in most cases, by the force applied by the hydraulic motor additional Bremsmo ^¬ ment is slowed down, the rotation motion such that the frictional ^¬ brake after the occurrence of an overload case back into the supply stand of the static friction can be converted and the distribution boom is stopped so on. If the placing boom is stopped, the hydraulic motor stops rotating in the sequence and thus can also apply no more braking torque; However, this is irrelevant, since in this case the friction brake is again in the state of static friction and then no additional braking torque by the hydraulic motor is required to secure the position of the distributor mast.

The functional unit is connected via a valve disposed between the two Zulei ^¬ obligations shuttle valve to the hydraulic motor to the hydraulic motor. The shuttle valve connects in a ^simple and reliable manner that supply line of the hydraulic engine with the functional unit in which the higher pressure is applied when the hydraulic motor is inactive. In the case of slipping of the slewing drive with inactive Hydrau ^¬ likmotor therefore that supply line whose volume flow is to be limited in order to decelerate the slewing drive. It is sawn vorzugt when the conveyed from the inactive-connected hydraulic motor in case of overload hydraulic oil is fed into a tank, wherein the functional unit is then arranged in the flow channel Zvi ^¬ rule hydraulic motor and the tank. In this case, preferably, the turning drive an anti-cavitation on, is ensured over the sufficient supply of the hydraulic motor with Hyd ^¬ rauliköl and idling of the hydraulic motors ^¬ is prevented.

It is in principle possible for hydraulic oil to flow through the functional unit even during active operation of the hydraulic motor. The air flowing through the functional unit limited Vo ^¬ volume flow must be taken into account when driving the hydraulic motor possibly similar to a leakage. In particular ^¬ sondere when the conveyed from the inactive hydraulic motor connected in hydraulic oil is fed into a tank, but it is preferred if the functional unit is a controllable

Locking device comprises, with which a flow of hydraulic ^¬ köl be selectively prevented by the functional unit can. By a suitably controlled blocking of the flow through the functional unit can be ensured that the hydraulic motor can be used in a known manner as a drive with active control, without causing hydraulic oil flows through the functional unit into the tank. In other words, the flow of hydraulic oil is to be prevented by the radio ^¬ tion unit in the case of an active-connected hydraulic motor, while in the case of inactivation tivity the hydraulic oil can flow through the functional unit. Can raulikölstroms for limiting the conveyed by the functional unit, the functional unit hy- grasp a flow control valve to ^¬. The flow control valve may have a constant unchangeable cross-section which is determined solely by the construction of the valve. But it is also possible that the cross section of the flow control valve is adjustable. Is a manu ^¬ elle adjustability provided, the cross section of Ven ^¬ TILs in particular before the first start-up and / or can be adjusted as ^¬ following maintenance, but remains constant during loading ^¬ drive of the rotary drive. If the cross-section of the flow control valve can be actively controlled, the cross-section and thus the given flow rate can be changed as planned during the operation of the slewing gear drive. The Stromven ^¬ til may be a throttle valve or an orifice valve.

Alternatively, or in addition to a flow control valve, the radio unit can tion also comprise a controlled proportional valve for Be ^¬ limitation of the volume flow. With a corresponding proportional valve, the predetermined volume flow during the operation of the slewing drive can be changed as planned, for example. Depending on in the range of the functional unit prevailing pressures.

The locking means, the flow control valve and / or the proportio ^¬ nalventil of the function unit are preferably hydraulically via Control lines or electrically controllable. Preferably, control lines and / or a control device are provided, which are designed for the above-described control of the individual components.

To explain the mobile concrete pump according to the invention, reference is made to the above statements.

The invention can be carried out in particular by simple Nachrüs ^¬ tion already existing slewing drives, with only a shuttle valve between the leads to the hydraulic motor of the existing slewing drive must be used. At this shuttle valve then a functional ^¬ unit is connected without further changes to the slewing drive would be required.

The invention will now be described by way of example with reference to advantageous embodiments with reference to the accompanying drawings. Show it:

Figure 1: a schematic representation of a first embodiment of a mobile concrete pump according to the invention with distribution boom comprising a slewing gear with inventive slewing drive;

FIG. 2 shows a circuit diagram of a first embodiment variant of the slew drive according to the invention from FIG

1;

FIG. 3 shows a circuit diagram of a second embodiment variant of the slew drive according to the invention from FIG

1;

4a, b: Schematics of third embodiment variants of the slew drive according to the invention of Figure 1; and 5a, b: Schematics of fourth embodiment variants of the slew drive according to the invention of Figure 1.

The mobile concrete pump 1 with distributor boom 2 shown in FIG. 1 is a truck-mounted concrete pump, in which the distributor boom 2 is fastened to a mobile substructure 3. The distribution boom 2 comprises a plurality of through Hydraulikzy ^¬ relieving 4 fold parts 5, in which (only partly shown) conveying line 6 is guided for flowing concrete. With the help of a arranged on the base 3 concrete pump 7 flowable concrete can be promoted from the hopper 8 through the feed line 6 with the free open end 9 of the delivery line 6.

For pivoting the distributor boom 2 relative to the base 3 in the azimuth direction, a slewing gear 10 is provided, which is shown in Figure 1 as an isolated detail.

With the slewing gear 10, the distribution boom 2 with respect to the substructure 3 can be arbitrarily rotated by +/- 360 °. For this purpose, the slewing gear 10 comprises a pivot bearing 11, which is arranged in the installed state between distributor boom 2 and substructure 3. The part of the pivot bearing 11, which is ver ^¬ connected with the distribution mast 2, has an outer toothing 12 in which engages a drive pinion 13 of a rotary drive fourteenth As explained in more detail below, the slew drive 14 is operated hydraulically. The delivery line 6 can be guided centrally through the pivot bearing 11 (not shown).

2 shows the circuit diagram of a first embodiment of the rotary drive 14 of the invention from figure 1 is found ^¬. The slewing drive 14 includes a hydraulic motor 15 and a hydraulically controlled friction brake 16, which always unfolds their braking ^¬ effect on the slewing drive 14 when it is depressurized. Not shown is a possibly between the hydraulic motor 15 and the drive pinion 13 of the rotary drive 14 (see Figure 1) provided gear.

The control of the rotational movement of the slew drive 14 via a 4/3-way valve 17 with floating center position. The 4/3-way valve 17 has a standard pressure port P, a tank port T and two working ports A, B. Depending on the position of the directional control valve 17, the working ports A, B are relieved of pressure, if necessary Nachsau ^¬ gene of hydraulic oil but connected to the pot connection T (see center position shown in Figure 2), or between the working ports is a pressure difference substantially corresponding to the pressure difference between the pressure port P and tank port T. With the selectability made possible by the valve 17, at which working port A, B the higher pressure is present, the direction of rotation of the hydraulic motor 15 can be adjusted.

Between the 4/3-way valve 17 and the hydraulic motor 15, a valve unit 18 is provided. The valve unit 18 comprises a per se known arrangement of check valves 19 and overload valves 20 to avoid overpressures on hydraulic motor 15. On the 4/3-way valve 17 side facing the valve unit 18 is still a shuttle valve 21 pre ^¬ see that between is arranged the coming of the Arbeitsauslässen a, B lines 15 and can flow freely in a hydraulic oil tank 22 via the excess Hyd ^¬ rauliköl inactivity of the hydraulic motor. The hydraulic oil tank 22 may of course be the tank which is connected to the tank connection T of the 4/3-way valve 17. In order to avoid that hydraulic oil at active circuit of the Hyd ^¬ raulikmotors 15 - on one of the working outlets A, B of the 4/3-way valve 17 is thus the ^¬ through the pressure port P supplied ^¬ operating pressure to -in the hydraulic oil tank 22 flows, is between shuttle valve 21 and hydraulic oil tank 22 a 3/2-way valve 23 with control line 23 ^λ provided. If operation ^¬ B of the 4/3-way pressure on one of the two working outputs A, valve 17 on, 21 and 3/2-way valve 23, and thus trol cable in the tax is this pressure in the line between the shuttle valve 23 ^λ of , By the pressure in the control line 23 ^λ , the 3/2-way valve 23 is adjusted, so that a drainage of hydraulic oil through the 3/2-way valve 23 is prevented.

At the same time, the pressure applied to the 3/2-way valve 23 is transmitted to the friction brake 16, which is thereby released. As soon Thus operating pressure is applied A, B of the 4/3-way valve 17 at one of the two Arbeitsauslässe, not only is the Hydrau ^¬ likmotor applied 15 with a required for the operating pressure differential, but it is also achieved the friction brake 16 simultaneously, so that the hydraulic motor 15 can actually turn.

As soon as the 4/3-way valve 17 is moved back into the floating middle position, no working pressure is applied to its working outputs A, B. The hydraulic motor 15 is thus switched inactive. At the same time, the pressure in the outgoing from the 3/2-way valve 23 line, whereby on the one hand, the friction brake 16, on the other hand, the 3/2-way valve 23 opens the line to the hydraulic oil tank 22 again.

According to the invention, on the side of the valve unit 18 facing the hydraulic motor 15 there is provided a second changeover valve 24 assigned to the functional unit 25, which is arranged between the two supply lines to the hydraulic motor 15 and via the hydraulic oil to the functional unit 25 and from there into the hydraulic oil tank 22 can pass.

The functional unit 25 comprises a as a throttle valve formed with un ^¬ variable cross section flow control valve 26 for limiting the volume flow through the functional unit 25 and via a control line 27 ^λ controllable blocking device 27, so that a flow of hydraulic oil through the function ^¬ unit 25 can be selectively inhibited. The Steuerlei ^¬ tion 27 ^λ is connected to the supply line to the friction brake 16 so that the locking device 27 in the case in which the

Friction brake 16 is released due to an active circuit of the hydra ^¬ likmotors 15, the flow of by the func ^¬ onseinheit 25 prevents, in the case of a tightened friction ^¬ brake 16, however, allows. In the function unit 25 at the active circuit Hyd ^¬ raulikmotors blocks 15, the operation of the rotating mechanism ^¬ drive 14 during active rotation of the distribution boom 2 relative to the base 3 (see FIG. 1) is not impaired. However, by the functional unit 25, the behavior of the rotary drive 14 in case of overload - ie with inactive Hydrau ^¬ likmotor 15 and slipping of the friction brake 16 - significantly improved.

In the case of slipping of the friction brake 16 of the hydra ^¬ likmotor 15 is set in rotation. The hydraulic motor 15 then acts as a pump for the hydraulic oil and delivers the hydraulic oil via the second shuttle valve 24 through the functional unit 25, the locking device 27 is opened in this case as described, in the hydraulic oil tank 22. Due to the flow control valve 26 of the hydraulic motor 15th however, limited volumetric flow, resulting in an additional braking torque on the hydraulic motor 15, which desired movement of the slewing gear in case of overload counteracts. The braking torque is described, in particular, from ^¬ pending on the throttling action of the flow valve 26th

If the hydraulic motor 15 conveys hydraulic oil through the functional unit 25 into the hydraulic oil tank as described, hydraulic oil is simultaneously sucked in via the tank connection T of the 4/3-way valve 17, so that the hydraulic lines of the slewing drive are continuously filled with hydraulic oil. In the Figures 3, 4a, b and 5a, b variants are shown to that shown in Figure 2 first embodiment of the rotating mechanism ^¬ drive fourteenth Below it is referred only to the differences from the embodiment of Figure 2 is ^¬ addressed and the remainder to the above explanations for FIG. 2 In the figures 3, 4a, b and 5a, b was further on the representation of the 4/3-way valve 17 with

Floating middle position dispensed and only the Arbeitsauslässen A, B indicated.

In the second embodiment of a slewing drive 14 according to the invention according to Figure 3, the flow control valve 26 is ^{ausgestal ¬} tet for limiting the flow rate through the functional unit 25 as a throttle valve with manually adjustable cross-section. The cross-section of the flow control valve 26 can thus be checked, for example, before the first start-up and during maintenance of the rotary drive 14 and, if necessary, readjusted.

4a, b, the control of the 3/2-way valve 23 (see FIG 4a) or the 3/2-way valve 23 and the locking device 27 of the functional ^¬ unit 25 (see Figure 4b) instead of control lines 23 27 ^λ (see Figure 2) electromagnetically. The control takes place due to electrical impulses, not one of generated control unit can be generated. By an electromagnetic control of the 3/2-way valve 23 and / or the blocking device 27 of the functional unit 25, it is pos ^¬ lich, the corresponding components in comparison to the direct control via control lines 23 27 ^λ (see Figure 2) as needed easy to time-delayed to control. This makes it for example. Possible to solve the friction brake 16 until the hydraulic motor 15 already brings a certain drive torque to ^¬. In the embodiments according to Figures 5a, b, instead of a flow control valve 26 (see FIGS. 2, 3a, b, 4a, b) a pro ^¬ portionalventil 28 is provided, with which the flow can be controlled or regulated during operation by the operation unit 25 , The control of the proportional valve 28, via the control line 28 directly ^λ depending on the place in the line between the second shuttle valve 24 and the function unit 25 (see FIG. 5a). But it is also possible that the proportional valve 28 is electromagnetically controlled by a control unit, not shown (see Figure 5b).

Claims

claims

Slewing gear drive (14), in particular for the distribution boom (2) of mobile concrete pumps (1), with a hydraulic motor (15) and a friction brake (16) for securing the slewing drive (14) in the inactivity of the hydraulic motor (15), characterized in that

the slewing drive (14) has a function unit (25) on ^¬ with which in the case of slippage in the friction ^¬ brake (16) from said inactive connected hydraulic motor (15) by the functional unit (25) supported hy- raulikölstrom to a predetermined volume flow is limited, wherein the functional unit (25) via a between the two leads to the hydraulic motor (15) arranged shuttle valve (24) is connected to the hydraulic motor (15).

Slewing drive according to claim 1,

characterized in that

from said inactive connected hydraulic motor (15) hydraulic oil conveyed in the overload case is conveyed into a hydraulic oil ^¬ tank (22), wherein the functional unit (25) in the flow channel between the hydraulic motor (15) and Hydrau ^¬ liköltank (22) is arranged.

Slewing drive according to one of the preceding claims, characterized in that

the functional unit (25) comprises a controllable blocking device (27) with which a flow of hydraulic oil through the functional unit (25) can optionally be prevented.

Slewing drive according to one of the preceding claims, characterized in that the functional unit (25) comprises a flow control valve (26) for limiting the hydraulic oil flow delivered by the functional unit (25).

Slewing drive according to claim 4,

characterized in that

the flow control valve (26) has a constant unchanging cross-section, a preferably manually adjustable cross-section or a controllable active cross-section has ^¬.

Slewing drive according to claim 4 or 5,

characterized in that

the flow control valve (26) is a throttle valve or a diaphragm valve ^¬.

Slewing drive according to one of the preceding claims, characterized in that

the functional unit (25) comprises a controlled proportional valve (28) for limiting the hydraulic fluid flow delivered by the functional unit (25).

Slewing drive according to one of claims 3 to 7, characterized in that

the locking device (27), the flow control valve (26) and / or the proportional valve (28) of the functional unit (25) hydraulically via control lines (27 28 ^λ ) or electromagnetically controlled.

Mobile concrete pump (1) with a distributor mast (2) pivotable in the azimuth direction relative to a substructure (3) via a slewing gear (10),

characterized in that

the slewing gear (10) comprises a slewing gear drive (14) according to one of claims 1 to 8.