DE102005005927A1 - Hydraulic control arrangement - Google Patents

Abstract

Hydraulic control arrangement (1) comprises an emergency operating valve (8) actuated by hand arranged in a control oil flow path. A directional control valve can be adjusted by the emergency operating valve to a position to actuate the consumer when the pilot valve arrangement (47) is in the base position. An independent claim is also included for a rotary disk valve for the above hydraulic control arrangement. Preferred Features: The emergency control valve shuts off the connection to a pressure reducing valve (30) in its switched positions (a, b). The emergency control valve is a rotary disk valve. The pilot valve arrangement has a pressure limiting valve (32) for limiting the pressure in the control oil flow path.

Description

The The invention relates to a hydraulic control arrangement for driving a consumer according to the generic term of claim 1 and a rotary valve for a hydraulic Control arrangement according to the preamble of claim 9.

such hydraulic control arrangements are used, for example, in loading cranes and other mobile work tools for the control of hydraulic consumers, such as Hydraulic cylinders or hydraulic motors used.

In the DE 199 48 232 A1 For example, a hydraulic control arrangement is shown, in which connections of a hydraulic cylinder can be connected via a 4/3-way valve with a variable displacement pump or a tank. The directional control valve is actuated by means of electrohydraulic pilot valves and is spring-centered in a middle position in which its pump connection, tank connection and the two working connections of the hydraulic cylinder are shut off from each other. The hydraulic control arrangement fulfills an emergency stop function, since after the failure of the electrical and / or hydraulic supply, the directional control valve assumes its central position by the spring preload and thus an unwanted consumer movement is excluded.

adversely in such hydraulic control arrangements is that after the failure of the electrical and / or hydraulic supply not more is possible is to operate the directional control valve and so that the consumer, for example, a crane, in a safe Move to position or to ensure emergency operation.

In contrast, lies The invention has the object, a hydraulic control system and a rotary valve for to provide a hydraulic control arrangement, the emergency operation of Enable consumers.

These Task is with respect to the hydraulic control system through the features of claim 1 and in terms of the rotary valve solved by the features of claim 9.

The inventive hydraulic Control arrangement for controlling a consumer, in particular a mobile work tool, has a pre-controlled by means of a pilot valve arrangement with a pump or pressure fluid sink (tank) connectable directional control valve. The pilot valve arrangement is at least one pressure reducing valve assigned to set a control pressure in a control oil flow path, when switching the pilot valve assembly from a home position connected to a control chamber of the directional control valve to the consumer to press. According to the invention hydraulic control assembly in the control oil flow path a manually operated Emergency valve, over the the directional control valve in the basic position of the pilot valve assembly is adjustable to a position to operate the consumer. About the Notbetätigungsventil can the directional valve even in case of failure of the electrical and / or operated hydraulic supply become. This makes it possible for the Consumer, for example, a loading crane, in a safe position to move or to ensure emergency operation.

at a preferred embodiment of Invention, the pilot valve assembly has two pilot valves, whose output each over a control channel and a pilot control line with a control room the directional control valve are connected, wherein the emergency actuation valve in a basic position opens the connection between the pilot valves to the control rooms and shuts off in its switching positions and one of the pilot control lines connects with a pressure medium source.

In his switching positions, the emergency operating valve locks preferably the connection to the pressure reducing valve, so that a loss of pressure medium is prevented during emergency operation of the control arrangement.

It becomes according to the invention preferred, the emergency valve form as a 6/3-way valve, in particular as a rotary valve. As a result, the valve is without big Effort by hand and in an emergency in the shortest time adjustable.

Basically the control arrangement according to the invention independently on the type of pump. To limit the pressure in the control oil flow path the pilot valve arrangement may preferably have at least one pressure relief valve.

When Pressure source is preferably a constant pump at bypass pressure balance Use.

at a failure of the electrical and hydraulic supply, can a hand-operated Auxiliary pump can be connected as a pressure source. About the Auxiliary pump it is possible the one for operation the consumer to produce required hydraulic pressure and thereby enabling an emergency operation.

The inventive rotary valve has a variety of connections and switching positions, wherein on a guided in a valve housing rotary valve Ring grooves are formed in each of a plurality of Perimeter sections formed longitudinal pockets open, the by turning the rotary valve with different connections in coverage can be brought to depend on from the switching position via the annular grooves and lengthwise pockets to establish a pressure medium connection between the annular grooves and terminals. According to the invention, the angular distance the arranged on a peripheral portion longitudinal pockets at least 90 °. Thereby will be a big one sealing surface between the adjacent longitudinal pockets and thus allowing a maximum sealing effect to the leakage losses to reduce.

at a preferred embodiment the invention, the rotary valve has a valve housing with a pressure port, two control input ports, two control output ports and a control pressure connection. In a basic position of the rotary valve is the pressure connection with the control pressure connection and respectively a control input terminal connected to a control output terminal. The pilot pressure port and the control input port are in a first switching position locked and the pressure port with the Control output terminal and the control input terminal with the Control output connection connected. In a second switching position the control pressure connection and the control input connection are blocked and the pressure port to the control output port and the control input port connected to the control output terminal. A connection opens at the front and the other connections on the circumference in a valve bore receiving the rotary valve one. This makes it possible both control rooms supply the directional control valve with pressure medium, this in its switching positions to adjust and the connected implements and the like in one safe position or to ensure emergency operation.

The Rotary valve preferably has two annular grooves, with the Valve bore two ring channels limit, wherein in a first annular channel of the pressure port and in the other second ring channel, a first control input terminal ends and the other peripherally opening connections in the axial distance to the ring channels open into the valve bore and depending on the setting position of the rotary valve on the circumference of the rotary valve arranged longitudinal pockets with the ring channels are connectable.

Of the second control input terminal opens as an axial connection in a rear side adjacent to the second annular channel, from an end face of the Rotary valve limited end portion of the valve bore and the other connections are preferably designed as radial connections. A first Control output connection opens in the area between the ring channels, the second control output port and the control pressure port offset by 90 ° flow in a front end section adjacent to the first annular channel one.

Preferably ends in the frontal area of the rotary valve an axial channel, which extends over two mutually perpendicular Radial holes in the periphery of the front end portion of the rotary valve empties. The radial bores are in the basic position and in a first Setting position hydraulically connected to the second control output terminal.

at an advantageous embodiment According to the invention, two longitudinal pockets extend from the first annular groove into the front end section. A first length pocket is in the home position with the pilot pressure port and the second longitudinal pocket in a second parking position with the second control pressure output port hydraulically connected. From the first annular groove to the second annular groove extends a third longitudinal pocket, in the first setting position with the first control output terminal connected is. A fourth and a fifth longitudinal pocket extend from the second annular groove towards the first annular groove. The fourth longitudinal pocket is in the basic position and the fifth longitudinal pocket in the second switching position connected to the first control output terminal.

Preferably are the first longitudinal pocket and the second longitudinal pocket around 180 °, the third longitudinal pocket and the fourth longitudinal pocket around 90 ° and the fourth and fifth vertical pocket offset by 90 ° arranged to each other, wherein the first longitudinal pocket and the third longitudinal pocket coaxial with each other. According to the invention, the angular distance of the a peripheral portion arranged longitudinal pockets at least 90 °. Thereby will be a big one sealing surface between the adjacent longitudinal pockets and thus allows a maximum sealing effect to the leakage losses to reduce.

The Rotary valve preferably has a safety device, which indicates an adjustment of the rotary valve from the home position. This will be the first time operation of the emergency valve signals warned more users of the hydraulic control and the maintenance personnel on the present error of the control arrangement made aware.

It has proved to be particularly advantageous if the safety device has a shear pin has, which is sheared off during the adjustment of the rotary valve.

At the front end portion of the rotary valve is preferably a Circumferential groove for receiving a sealing element, in particular a sealing ring designed to reduce the leakage losses.

Preferably limits the back face the rotary valve with an adjacent end face of the valve bore a white space.

other advantageous developments of the invention are the subject of further Dependent claims.

in the The following will be a preferred embodiment of the invention explained in more detail with reference to schematic drawings. Show it:

1 a circuit diagram of a valve disc for pressure medium supply of a first and a second consumer port;

2 a spatial representation of a concrete embodiment of a rotary valve according to the invention and

3 a sectional view of an actuating device of the rotary valve 2 ,

1 shows a schematic circuit diagram of a valve disc 1 executed control arrangement for pressure medium supply of a first consumer port C and a second consumer port D. This consists essentially of a two pilot valves 2 . 4 operated 4/3-way valve 6 and one as a 6/3-way rotary valve 8th trained emergency valve.

The pressure medium supply of the valve disc 1 takes place in the illustrated embodiment via a pump port P which is connected to a pump, not shown, via the pressure medium into a pump line 10 is encouraged. From the pump line 10 branches a bypass line 12 to a tank channel 13 , which flows into a tank connection T. In the bypass line 12 is a continuously operable inlet pressure compensator 14 arranged in the opening direction from the pressure in the pump line 10 and in the closing direction of the highest load pressure of all consumers connected to the consumer terminals C, D and a spring 16 is charged. The highest load pressure is in a known manner via a shuttle valve cascade 18 tapped by all consumers of the system and is located on a load reporting line 20 at the inlet pressure balance 14 at. That is, the control arrangement 1 is designed as a LS (Load Sensing) system in which the highest load pressure of the driven loads via the load-sensing line 20 and an LS port LS reported to a pump, not shown, and this is regulated so that in the pump line 10 a certain pressure difference .DELTA.p is above the load pressure lying pump pressure, wherein the pressure difference .DELTA.p of the force of the spring 16 equivalent. From the pump line 10 branches another bypass line 22 to the tank channel 13 and the tank port T, in which a primary pressure relief valve 24 is arranged, over which the maximum pressure in the pump line 10 is limited. The pump can be designed as a fixed displacement pump with speed-controlled drive or as a variable displacement pump.

From the pump line 10 continues to branch a control pressure line 26 for supplying a control pressure source 28 consisting of a pressure reducing valve 30 and a pressure relief valve 32 from. A control output line 34 the pressure reducing valve 30 is to Redudierung of in the control pressure line 26 pending pump pressure to the maximum control pressure to a Steurdruckversorgungsleitung 36 connected. The control pressure limiting valve 32 is with the pilot pressure supply line 36 and a control pressure relief line 38 connected to the maximum pressure in the control pressure supply line 36 to limit. For the control pressure relief line 38 is a port Y on the valve disc 1 available. One connection X to the external control oil supply of the valve disc 1 is closed.

Via the 4/3-way valve 6 the pressure medium supply to the load ports C, D is controlled. This has a pressure port P and two working ports A, B, which in the illustrated spring-biased basic position ( 0 ) via one outlet flow restrictor each 40 with a tank connection T of the directional valve 6 and over the tank line 64 with the tank channel 13 and the tank port T of the valve disc 1 are connected. The pressure port P of the valve disc 1 is connected to the input port P of the directional control valve via the pump line 10 connected. In the control positions of the directional valve marked with (a) 6 is via a control edge another drainage restrictor 40 between the working port A and the tank port T of the directional control valve 6 open. At the control positions marked with (b) lies the drainage restrictor 40 between the working connection B and the tank connection T. The working connections A, B are via two working channels 42 . 44 connected to the consumer terminals C and D respectively. To simplify the explanation, it is assumed that the in 1 upper, with a damping throttle 46 provided working channel 42 the supply channel is, while the bottom re, with the consumer terminal D connected working channel 44 the drainage channel is. With appropriate switching of the directional control valve 6 then the flow channel to the drain channel and vice versa.

The control of the 4/3-way valve 6 via the two pilot valves 2 . 4 , which are designed as electro-hydraulically operated 3/2-way valves and a pilot valve assembly 47 form. These are connected to a pressure input P via a bypass line 48 to the control pressure supply line 36 , with a tank outlet T via a bypass line 50 with the control pressure relief line 38 connected and with a control output R via one control channel 52 . 54 and a pilot control line 56 . 58 each with a control room 60 . 62 of the directional valve 6 connectable.

According to the invention is in the control oil flow path, ie between the pilot valves 2 . 4 and the directional valve 6 the manually operated emergency valve 8th arranged over which the directional control valve 6 in the illustrated basic position ( 0 ) of the pilot valves 2 . 4 is adjustable in a position to supply the consumer ports C, D with pressure medium. About the emergency valve 8th can the directional valve 6 be operated even in case of failure of the electrical and / or hydraulic supply. This makes it possible to supply the consumer ports C, D with pressure medium and to move connected implements and the like in a safe position, or to ensure emergency operation.

This is the emergency valve 8th as a 6/3-way rotary valve with a pressure port P two control input terminals X1, X2, two control output terminals Y1, Y2 and a control pressure port Z executed. The control input terminals X1, X2 are above the control channel 52 to the pilot valve 2 or via the control channel 54 to the pilot valve 4 connected. The control output terminals Y1, Y2 are via the pilot control lines 56 . 58 each with one of the two control rooms 60 . 62 of the directional valve 6 , the pressure port P to the pump line 10 and the control pressure port Z to the control pressure line 26 connected.

In the illustrated basic position ( 0 ) of the emergency valve 8th For example, the control input terminals X1, X2 are respectively connected to the control output terminals Y1, Y2, and the pressure port P is connected to the control pressure port Z. As a result, in normal operation of the hydraulic control arrangement 1 a control of the directional control valve 6 via the pilot valves 2 and 4 and a pressure medium supply of the control pressure wave 28 possible.

In case of failure of the pilot valves 2 . 4 is the directional valve 6 due to the spring preload in the illustrated basic position ( 0 ), where the working channels 42 . 44 via a tank line 64 and the tank channel 13 with the tank connection T of the control arrangement 1 are connected.

Thereby a consumer operation is prevented and achieves an emergency stop function.

To the consumer, for example, a crane even in the event of failure of the pilot valves 2 . 4 to move to a safe position, or to ensure emergency operation, the directional control valve 6 even with a failure of the electrical and / or hydraulic supply via the emergency valve 8th be operated. In the event of failure of the pressure medium source, the pressure required to actuate the load can be transmitted to the pump line by means of a pressure, not shown 10 or connect the pressure port P, auxiliary pump can be applied.

For emergency operation of the directional control valve 6 are in a first switching position (a) of the emergency valve 8th the control pressure port Z and the control input port X1 are disabled, and the pressure port P is connected to the control output port Y1 and the control input port X2 is connected to the control output port Y2. This will be the control room 62 acted upon by the pump pressure, the directional control valve 6 adjusted to its switching position (b) and the consumer port D supplied with pressure medium. In the second switching position indicated by (b), the control pressure port Z and the control input port X2 are disabled, and the pressure port P is connected to the control output port Y2 and the control input port X1 is connected to the control output port Y1. In this switching position of the emergency control valve 8th becomes the control room 60 of the directional valve 6 acted upon by the pump pressure, the directional control valve 6 adjusted to its switching position (a) and the consumer port C supplied with pressure medium. This makes it possible to supply both consumer ports C, D with pressure medium and to move connected implements and the like in a safe position, or to ensure emergency operation.

The essential difference of the above-described solution to the prior art is thus that the directional control valve 6 even with a failure of the pilot valves 2 . 4 via the manually operated emergency valve 8th can be adjusted.

2 shows a concrete embodiment of a rotary valve according to the invention 8th , This has a hatched indicated valve housing 66 with a valve bore 68 and a guided therein about cylindrical rotary valve 70 , This has at a front end portion 72 a circumferential groove 74 for receiving a sealing ring 76 (please refer 3 ) and goes into a likewise cylindrical handling section 78 with smaller diameter over. The rotary valve 8th has the pressure port P, two control input ports X1, X2, and two control output ports Y1, Y2 and a control pressure port Z, with the control input port X2 in the front side of the rotary valve 70 receiving valve bore 68 and the control input terminal X1, the control output terminals Y1, Y2, the pressure port P and the control pressure port Z circumferentially in the valve bore 68 open out. A back face 80 of the rotary valve 70 limited to an adjacent end face 82 the valve bore 68 a white space 84 ,

On the rotary valve 70 are two ring grooves 86 . 88 formed with the valve bore 68 two ring channels 90 . 92 limit, wherein in the first annular channel 90 the pressure port P and in the other second annular channel 92 a first control input terminal X1 opens and the other peripherally opening ports Y1, Y2, Z at the axial distance to the ring channels 90 . 92 into the valve bore 68 open out.

The second control output connection X2 opens as an axial connection in one to the second annular channel 92 adjacent back from the frontal area 80 of the rotary valve 70 limited end section 94 the valve bore 68 , The first control control output terminal Y1 opens in the area between the ring channels 90 . 92 the second Steuerausgangsanschuss Y2 and the offset by 90 ° control pressure port Z in the first annular channel 90 adjacent front end portion 72 of the rotary valve 70 one.

In the face 80 of the rotary valve 70 is an axial channel 96 formed, which has two mutually perpendicular radial bores 98 . 100 in the circumference of the front end portion 72 of the rotary valve 70 empties. The radial bores 98 . 100 are in the basic position ( 0 ) and in a first setting position (a) of the rotary valve 70 hydraulically connected to the second control output port Y2.

Starting from the first ring groove 86 extend two longitudinal pockets 102 . 104 in the front end section 72 of the rotary valve 70 into it. The first longitudinal pocket 102 is in the basic position ( 0 ) of the rotary valve 70 with the control pressure port Z and the second longitudinal pocket 104 in a second setting position (b) hydraulically connected to the second control pressure output port Y2. From the first ring groove 86 to the second annular groove 88 towards a third longitudinal pocket extends 106 which is connected to the first control output terminal Y1 in the first setting position (a). A fourth longitudinal pocket 108 and a fifth long pocket 110 extend from the second annular groove 88 towards the first ring groove 86 , wherein the fourth longitudinal pocket 108 in the basic position ( 0 ) and the fifth longitudinal pocket 110 in the second switching position (b) is connected to the first control output terminal Y1. The lengthwise pockets 102 to 110 run along the rotary valve surface and have an approximately rectangular basic shape, which is rounded in the region of the terminals in each case arcuately.

The first longitudinal pocket 102 and the second longitudinal pocket 104 are 180 °, the third longitudinal pocket 106 and the fourth longitudinal pocket 108 by 90 ° and the fourth longitudinal pocket 108 and fifth long pocket 110 arranged offset by 90 ° to each other. The first longitudinal pocket 102 and the third longitudinal pocket 106 are coaxial with each other. That is to say the angular spacing of the longitudinal pockets arranged on a circumferential section is at least 90 °. As a result, a large sealing surface between the adjacent longitudinal pockets and thus a maximum sealing effect is made possible in order to reduce the leakage losses.

in principle can the connections and the lengthwise pockets also with other angular distances in the valve housing or be arranged in the rotary valve.

In the illustrated basic position ( 0 ) of the emergency valve 8th (0 ° position), the control input terminals X1, X2 are respectively connected to the control output terminals Y1, Y2 and the pressure port P to the control pressure port Z. This is in normal operation of the hydraulic control system 1 a control of the directional control valve 6 via the pilot valves 2 . 4 and a pressure medium supply of the control pressure source 28 possible (see 1 ).

For emergency operation of the directional control valve 6 are in a first switching position (a) of the emergency valve 8th (-90 ° position), the control pressure port Z and the control input port X1 are disabled and the pressure port P is connected to the control output port Y1 and the control input port X2 is connected to the control output port Y2. This will be the control room 62 acted upon by the pump pressure, the directional control valve 6 adjusted to its switching position (b) and the consumer port D supplied with pressure medium (see 1 ). At the (b) marked second switching position of the emergency valve 8th (90 ° position), the control pressure port Z and the control input port X2 is disabled, and the pressure port P is connected to the control output port Y2 and the control input port X1 is connected to the control output port Y1. In this switching position of Notbetäti supply valve 8th becomes the control room 60 acted upon by the pump pressure, the directional control valve 6 adjusted to its switching position (a) and the consumer port C supplied with pressure medium. That is, in the switching positions (a), (b) of the rotary valve 8th It is possible to supply the consumer ports C, D with pressure medium and to move connected implements and the like in a safe position, or to ensure emergency operation.

According to 3 , which is a sectional view of an actuator 114 of the rotary valve 8th shows, this has an operating handle 116 with an approximately hollow cylindrical body 118 attached to the housing cover 120 of the valve housing 66 facing end portion 122 a holding section 124 formed with a reduced diameter. The holding section 124 indicates on its inner circumference 126 frontally an annular projection 128 on, a mushroom-shaped projection 130 of the housing cover 120 engages behind and the operating handle 116 on the housing cover 120 rotatably fixed. The housing cover 120 is non-rotatable with the valve body 66 bolted and the operating handle 116 rotatably with the cylindrical handling section 78 of the rotary valve 70 connected.

At the front end portion 72 of the rotary valve 70 is a circumferential groove 74 for receiving the sealing ring 76 Designed to prevent leakage from the housing cover 120 and the rotary valve 70 limited annulus 132 to avoid the outside.

The rotary valve 70 is in the shown basic position ( 0 ) of one by a spring 136 charged ball 138 fixed in a radial blind hole 140 of the housing cover 120 is used. The spring-loaded ball 138 emerges from the blind hole 140 in sections, and in a recess 142 of the rotary valve 70 one.

In the handling section 78 is a radially projecting stop pin 144 inserted, resulting in a non-circumferential groove 146 of the housing cover 120 extends and the adjustment of the rotary valve 70 limited to + 90 ° to -90 °. As a result, the two rotated switching positions of the rotary valve 70 Are defined.

Disclosed is a hydraulic control arrangement 1 for controlling a consumer, in particular a mobile working device, via a by means of a pilot valve arrangement 47 pilot operated directional control valve 6 with a pump or a pressure medium sink (tank) can be connected, wherein the pilot valve arrangement 47 at least one pressure reducing valve 30 for adjusting a control pressure in a control oil flow path, which when switching the pilot valve arrangement 47 from a basic position ( 0 ) with a control room 60 . 62 connected to the directional control valve to actuate the consumer. According to the invention in the control oil flow path is a manually actuated emergency actuation valve 8th arranged over which the directional control valve 6 in the basic position ( 0 ) of the pilot valve assembly 47 is adjustable to a position to operate the consumer.

1

control arrangement

2

pilot valve

4

pilot valve

6

way valve

8th

Rotary valve

10

pump line

12

bypass line

13

tank channel

14

Inlet pressure

16

feather

18

Cascade of shuttle valves

20

Load-sensing line

22

bypass line

24

Primary pressure relief valve

26

Control pressure line

28

Control pressure source

30

Pressure reducing valve

31

Return line

32

Pressure relief valve

33

control spring

34

Control output line

36

Control pressure supply line

38

Control pressure relief line

40

orifice

42

working channel

44

working channel

46

damping throttle

47

Pilot valve arrangement

48

Steuerölzuführleitung

50

Pilot oil tank line

52

control channel

54

control channel

56

pilot line

58

pilot line

60

control room

62

control room

64

tank line

66

valve housing

68

valve bore

70

rotary vane

72

front end

74

circumferential groove

76

sealing ring

78

handling section

80

rear face

82

front

84

whitespace

86

first ring groove

88

second ring groove

90

annular channel

92

annular channel

94

back end

96

axial

98

radial bore

100

radial bore

102

first vertical pocket

104

second vertical pocket

106

third vertical pocket

108

fourth vertical pocket

110

fifth long pocket

112

peripheral portion

114

actuator

116

operating handle

118

body

120

housing cover

122

end

124

maintenance section

126

inner circumference

128

head Start

130

head Start

132

annulus

134

vent hole

136

feather

138

Bullet

140

Blind hole

142

recess

144

shear pin

146

groove

Claims (18)

Hydraulic control arrangement ( 1 ) for controlling a consumer, in particular a mobile working device, via a by means of a pilot valve arrangement ( 47 ) Pilot operated directional control valve ( 6 ) is connectable to a pump or a pressure medium sink (tank), wherein the pilot valve arrangement ( 47 ) at least one pressure reducing valve ( 30 ) for adjusting a control pressure in a control oil flow path, which when switching the pilot valve assembly ( 47 ) from a basic position ( 0 ) with a control room ( 60 . 62 ) of the directional valve ( 6 ) is actuated to actuate the consumer, characterized in that in the control oil flow path a manually operable emergency actuation valve ( 8th ) is arranged, via which the directional control valve ( 6 ) in the basic position ( 0 ) of the pilot valve arrangement ( 47 ) is adjustable to a position to operate the consumer. Control arrangement according to claim 1, wherein the pilot control valve arrangement ( 47 ) two pilot valves ( 2 . 4 ) whose output (R) in each case via a control channel ( 52 . 54 ) and a pilot control line ( 56 . 58 ) with a control room ( 60 . 62 ) of the directional valve ( 6 ), wherein the emergency actuation valve ( 8th ) in a basic position ( 0 ) the connection between the pilot valves ( 2 . 4 ) to the control rooms ( 60 . 62 ) and in its switching positions (a, b) shuts off and one of the pilot control lines ( 56 . 58 ) connects to a pressure medium source. Control arrangement according to claim 1 or 2, wherein the emergency actuation valve ( 8th ) in its switching positions (a, b) the connection to the pressure reducing valve ( 30 ) locks. Control arrangement according to one of the preceding claims, wherein the emergency actuation valve ( 8th ) is a 6/3-way valve. Control arrangement according to one of the preceding claims, wherein the emergency actuation valve ( 8th ) is a rotary valve. Control arrangement according to one of the preceding claims, wherein the pilot control valve arrangement ( 47 ) at least one pressure relief valve ( 32 ) for limiting the pressure in the control oil flow path. Control arrangement according to one of the preceding claims, wherein the pressure source is a fixed displacement pump with inlet pressure compensator. Control arrangement according to one of the preceding claims, wherein a hand-operated Auxiliary pump can be connected as a pressure source. Rotary valve ( 8th ), in particular for a hydraulic control arrangement ( 1 ) according to one of the preceding claims, having a plurality of terminals (X1, X2, Y1, Y2, Z, P) and switching positions (a, 0, b), wherein on one in a valve housing ( 66 ) guided rotary valve ( 70 ) Annular grooves ( 86 . 88 ) are formed, in each of which a plurality of formed on peripheral portions longitudinal pockets ( 102 to 110 ), by turning the rotary valve ( 70 ) can be brought into overlap with different terminals (Y1, Y2, Z) in order to be able to move in dependence on the switching position (a, b) via the annular grooves ( 86 . 88 ) and longitudinal pockets ( 102 to 110 ) a pressure medium connection between the annular grooves ( 86 . 88 ) and connections (Y1, Y2, Z), characterized in that the angular distance of the arranged on a peripheral portion longitudinal pockets ( 102 to 110 ) is at least 90 °. Rotary slide valve according to claim 9, with a valve housing ( 66 ) having a pressure port (P), two control input ports (X1, X2), and two control output ports (Y1, Y2) and a pilot pressure port (Z), wherein in a home position ( 0 ), the pressure port (P) to the control pressure port (Z) and a respective control input port (X1, X2) to a control output port (Y1, Y2) is connected and in a first switching position (a), the control pressure port (Z) and the control input terminal (X1) are disabled and the pressure port (P) to the control output port (Y1) and the control input port (X2) to the control output port (Y2) are connected, and in a second switching position (b) of the control pressure port (Z ) and the control input terminal (X2) are disabled and the pressure port (P) is connected to the control output port (Y2) and the control input port (X1) is connected to the control output port (Y1), the port (X2) being at the front and the other ports (X1, Y1, Y2, P, Z) circumferentially in a rotary valve ( 70 ) receiving valve bore ( 68 ). Rotary slide valve according to claim 10, with two annular grooves ( 86 . 88 ) with the valve bore ( 68 ) two ring channels ( 90 . 92 ), wherein in a first annular channel ( 90 ) the pressure port (P) and in the other second annular channel ( 92 ) opens a first control input terminal (X1) and the other peripherally opening terminals (X1, Y1, Y2, P, Z) at the axial distance to the ring channels ( 90 . 92 ) into the valve bore ( 68 ) and in dependence on the setting position (a, 0, b) of the rotary valve ( 70 ) over the circumference of the rotary valve ( 70 ) arranged longitudinal pockets ( 102 to 110 ) with the ring channels ( 90 . 92 ) are connectable. Rotary slide valve according to claim 11, wherein the second control input connection (X2) as axial connection ( 96 ) in a to the second annular channel ( 92 ) adjacent back, from an end face ( 80 ) of the rotary valve ( 70 ) limited end section ( 94 ) of the valve bore ( 68 ) and the other terminals are formed as radial terminals (X1, Y1, Y2, P, Z), wherein a first control output terminal (Y1) in the region between the ring channels ( 90 . 92 ), the second control output connection (Y2) and the control pressure connection (Z) offset by 90 ° in a direction to the first annular channel (Y2) 90 ) adjacent front end portion ( 72 ). Rotary slide valve according to claim 12, wherein in the end face ( 80 ) of the rotary valve ( 70 ) an axial channel ( 96 ), which via two mutually perpendicular radial bores ( 98 . 100 ) in the periphery of the front end portion ( 72 ) of the rotary valve ( 70 ), whereas in the basic position ( 0 ) and in a first setting position (a) are hydraulically connected to the second control output terminal (Y2). Rotary slide valve according to claim 13, wherein two longitudinal pockets ( 102 . 104 ) of the first annular groove ( 86 ) in the front end portion ( 72 ), wherein a first longitudinal pocket ( 102 ) in the basic position ( 0 ) with the control pressure connection (Z) and the second longitudinal pocket ( 104 ) is hydraulically connected in a second setting position (b) to the second control pressure output port (Y2), and wherein from the first annular groove ( 86 ) to the second annular groove ( 88 ) a third longitudinal pocket ( 106 ) which is connected to the first control output terminal (Y1) in the first setting position (a) and extends from the second annular groove (9) 88 ) to the first annular groove ( 86 ) a fourth and a fifth longitudinal pocket ( 108 ; 110 ), the fourth longitudinal pocket ( 108 ) in the basic position ( 0 ) and the fifth longitudinal pocket ( 110 ) are connected to the first control output terminal (Y1) in the second switching position (b). Rotary slide valve according to claim 14, wherein the first longitudinal pocket ( 102 ) and the second longitudinal pocket ( 104 ) by 180 °, the third longitudinal pocket ( 106 ) and the fourth longitudinal pocket ( 108 ) by 90 ° and the fourth and fifth longitudinal pocket ( 108 ; 110 ) are arranged offset by 90 ° to each other, wherein the first longitudinal pocket ( 102 ) and the third longitudinal pocket ( 106 ) are coaxial with each other. Rotary slide valve according to one of the claims 9 to 15, wherein the rotary valve ( 70 ) at the front end portion ( 72 ) a circumferential groove ( 74 ) for receiving a sealing element ( 76 ), in particular a sealing ring. Rotary slide valve according to one of the claims 9 to 16, wherein the rear end face ( 80 ) of the rotary valve ( 70 ) with an adjacent end face ( 82 ) of the valve bore ( 68 ) a white space ( 84 ) limited. Rotary slide valve according to one of the claims 9 to 17, wherein a positioning element ( 138 ), preferably a spring-loaded ball, in the basic position ( 0 ) of the rotary valve ( 70 ) fixed.