Information
-
Patent Grant
-
6481461
-
Patent Number
6,481,461
-
Date Filed
Thursday, September 20, 200122 years ago
-
Date Issued
Tuesday, November 19, 200221 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 060 436
- 137 596
- 137 62523
-
International Classifications
-
Abstract
A hydraulic pilot control system having two control outputs to which a control pressure can be applied and having a hydraulic pilot controller, which has a handle which can be pivoted from a neutral position in a first direction and in a second direction, and a pressure valve that can be displaced from the neutral position by the deflection of the handle. During pivoting of the handle in the first direction and during pivoting of the handle in the second direction, the pressure valve can be adjusted with the same effect, and wherein there is a directional control valve which, depending on the pivoting direction of the handle, connects a control output of the pressure valve to the first control output or to the second control output, whereby a behavior of the pilot control pressure which is symmetrical with respect to the deflection of the control lever in the two directions is adjustable in a simple way.
Description
FIELD AND BACKGROUND OF THE INVENTION
The invention is based on a hydraulic pilot control system having two control outputs (
96
,
97
) to which a control pressure can be applied and having a hydraulic pilot controller, which has a handle (
81
) which can be pivoted from a neutral position in a first direction to apply a variable control pressure to the first control output (
96
) and in a second direction, which is preferably opposite to the first direction, to apply a variable control pressure to the second control output (
97
), and a pressure valve (
69
) which can be displaced from the neutral position by the deflection of the handle (
81
) and generates a control pressure at a control output (
80
).
Such a hydraulic pilot control system is disclosed, for example, by DE 196 30 798 A1. This pilot control system comprises a pilot controller which contains a plurality of pressure reducing valves, by which a pilot control pressure can be generated by each at a control output. The pilot controller has a control lever which, from a neutral position, can be pivoted in a first direction to adjust a first pressure reducing valve and in a second direction, opposed to the first direction, to adjust a second pressure reducing valve. In general, after the control lever has been pivoted through a specific angle in the first direction, the pilot control pressure then present on the first control output is different from the pilot control pressure present on the second control output when the control lever is deflected by the same angle in the second direction. This can be attributed to the tolerances with which the individual components of a pressure reducing valve are afflicted. In particular, the tolerances of the control spring of a pressure valve influence the pilot control pressure.
The difference in the pilot control pressures at a specific pivoting angle of the control lever is not desirable in certain cases. In addition, there are applications in which, irrespective of the pivoting direction, the intention is for the same pressure to be present either on the first control output or on the second control output after a specific pivoting angle of the control lever. For example, a hydraulic control arrangement for a winch is known in which pivoting the control lever from its neutral position firstly adjusts a proportionally adjustable directional control valve from its mid-position in one direction or in the other direction, depending on the pivoting direction of the control lever. Beginning at a specific pivoting angle of the control lever, the feed diaphragm of the directional control valve is completely open. Starting at this pivoting angle, irrespective of the pivoting direction of the control lever, the absorption volume of a hydraulic motor driving the winch drum is then set as a function of the pilot control pressure. This adjustment is intended to take place starting at a specific pivoting angle of the control lever which can be sensed by the operator by means of a pressure point. Previously, a great deal of adjustment work has been needed if, firstly, it is wished to have the same pilot control pressure in the two control outputs in each case, irrespective of the pivoting direction, after a specific pivoting angle of the control lever, and if this pilot control pressure is also intended to have a specific value.
The invention is based on the object of developing a hydraulic pilot control system having the introductory-mentioned features in such a way that, irrespective of the pivoting direction of the handle, after a specific pivoting angle, one simply has a specific pilot control pressure at one of the control outputs. The aim is also to configure the known hydraulic pilot control system more cost-effectively.
The object is achieved wherein a hydraulic pilot control system having the introductory-mentioned features, has a pressure valve which, when the handle is pivoted in the first direction and when the handle is pivoted in the second direction, can be adjusted with the same effect, and has a directional control valve which, depending on the pivoting direction of the handle from a rest position, which it assumes in the neutral position of the handle, can be changed over into a first switching position, in which it connects the control output of the pressure valve to the first control output, or into a second switching position, in which it connects the control output of the pressure valve to the second control output. Therefore, in the case of a hydraulic pilot control system according to the invention, only one pressure valve is provided for two pivoting directions of the handle. Therefore, tolerances in the components of the pressure valve no longer influence the difference in the values of the pilot control pressures after the handle has been pivoted by a specific pivoting angle. If the adjustment of the pressure valve as a function of the pivoting angle is made equal for both pivoting directions of the handle, then in each case the pilot control pressure is also irrespective of the pivoting direction. If it is wished to have a specific pilot control pressure at a specific pivoting angle, then it is necessary for only a single pressure valve to be adjusted. Furthermore, a directional control valve can generally be produced with less effort than a pressure valve having many individual parts. A hydraulic pilot control system according to the invention can therefore also be produced more cost-effectively.
For example, according to other features, in the rest position of the directional control valve, the two control outputs are relieved of pressure via a tank connection of the directional control valve, circumventing the pressure valve. Intrinsically, in the rest position of the directional control valve, relieving the pressure on the control outputs would also be possible via the pressure valve, since in the neutral position of the handle, the control output of the pressure valve is relieved of pressure.
According to still other features, the directional control valve preferably has, as a movable control element, a rotary slide, whose axis is aligned with the axis of rotation of the handle and which can be rotated via the handle in a valve bore in a valve housing. Even at large pivoting angles of the handle, there are no difficulties here in connecting the control element of the directional control valve and the handle to each other. The rotary slide is advantageously urged by an axial stop against a stop on the valve housing by a spring, so that it always assumes the same axial position and reliably controls the connections between individual ducts opening into the valve bore.
A refinement according to the invention is particularly preferred wherein there is a permanently set pressure reducing valve, which serves for the internal control pressure supply and which is accommodated in a space-saving way in an axial bore in the control element of the directional control valve, formed as a slider. One speaks of an internal control pressure supply when a pressure reducing valve generates from a high system pressure a significantly lower control pressure, which is fed to an adjustable pressure valve.
According to another feature of the invention, the relationship between the displacement of the pressure valve, at least over a large angle range, when the handle is pivoted in the second direction from the neutral position is the same as when the handle is pivoted in the first direction from the neutral position. This may easily be achieved by a control disk for the pressure valve which is appropriately configured and can be rotated by the handle. At the same pivoting angle, therefore, irrespective of the pivoting direction, in each case the same pilot control pressure is present on one of the two control outputs. This is particularly advantageous if a hydraulic appliance is to be controlled in the same way irrespective of the pivoting direction of the handle.
A specific pilot control pressure at a specific pivoting angle may be set in a particularly simple way by the pressure valve being adjustable from the outside after its components have been mounted in a housing. In this case, two advantageous possible ways of adjusting the pressure valve are provided. According to one way, an adjusting spring is provided, whose prestress can be varied by means of an adjustable stop, so that a total spring force which results from the force of the control spring and from the force of the adjusting spring and acts on the control element may be adjusted. According to another way, for the purpose of adjustment, the control edges fixed to the housing are displaced axially, so that the control position of the movable control element and, therefore, at a given axial position of the plunger, the prestress of the control spring in the control position of the control element is changed. By means of a combination of the features of these two ways, both the level of the pilot control pressure at a specific pivoting angle of the handle, and also the idle angle between the neutral position of the handle and the start of a pilot control pressure build-up can be adjusted.
A refinement according to the invention is particularly preferred wherein the plunger is guided in a guide sleeve. The control cartridge, which is inserted adjustably into a housing in order to vary the position of the control edges fixed to the housing, is extended beyond the control edges and accommodates the guide sleeve in a captive manner. The control cartridge, the guide sleeve and the movable parts of the pressure valve therefore form a structural unit, which can be handled as a whole and can be simply mounted as a whole in a housing. Reference is expressly made to the fact that the configuration of a pressure valve according to this refinement is also advantageous when this pressure valve is used in conventional pilot controllers, in which there is generally an adjustable pressure valve for every pivoting direction of the handle.
BRIEF DESCRIPTION OF THE DRAWINGS
An exemplary embodiment of a hydraulic pilot control system according to the invention is illustrated in the drawing. The invention will now be explained in more detail using the figures of this drawing, in which:
FIG. 1
shows the exemplary embodiment in a circuit diagram in which the control lever and the angle ranges in which the control lever is located during the various operating modes are also represented schematically,
FIG. 2
shows a partial section through a pilot controller at right angles to the axis of the control lever, the section plane for the restoring device and the housing being different from that for the pilot control valve,
FIG. 3
shows the shaft which can be rotated by the control lever and has cam tracks, the pressure piece of the restoring device and a plunger belonging to the pilot control valve in a position which the parts assume when the control lever is deflected to the maximum in the easing direction,
FIG. 4
shows the same parts as in
FIG. 3
in a position in which the control lever has been deflected from its neutral position through 15° into the hoisting angle range,
FIG. 5
shows the same parts as in
FIG. 4
after a deflection of the control lever through 25°,
FIG. 6
shows the parts from
FIG. 5
after a deflection of the control lever through 45° as far as the end of the hoisting angle range,
FIG. 7
shows the parts from
FIG. 6
after a deflection of the control lever through 57° as far as the start of the mooring angle range,
FIG. 8
shows the parts from
FIG. 7
after the control lever has been pivoted through 100° as far as the end of the mooring angle range,
FIG. 9
shows a section along the line IX—IX from FIG.
2
and
FIG. 10
shows the unrolled groove pattern of the rotary slide of the directional control valve, via which the control output of the adjustable pressure valve can be connected to one control output, to the other or to both control outputs.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1
reveals a winch
10
, which can be driven in opposite directions via a gearbox
11
via an adjustable hydraulic motor
12
. Arranged between the output shaft of the hydraulic motor and the gearbox is a brake
13
, which can be actuated via a single-acting hydraulic cylinder
14
. The hydraulic cylinder
14
is constructed in the manner of a differential cylinder, whose piston and piston rod can be displaced by a spring with the effect of engaging the brake. By applying pressure medium to the annular chamber
15
of the hydraulic cylinder
14
, piston and piston rod are moved back counter to the force of the spring and, as a result, the brake
13
is released. The absorption volume of the hydraulic motor
12
may be adjusted continuously on the basis of a control pressure applied to the control input
16
, and is smaller the greater the control pressure. For the adjustment, there are an actuating cylinder
17
constructed as a differential cylinder and a pump control valve
18
. The latter has a tank connection, which is connected to a leakage oil line
19
, a pressure connection which is connected via two nonreturn valves
20
to the motor connection
21
or
22
, respectively, and a cylinder connection connected to the pressure chamber, on the side remote from the piston rod, of the actuating cylinder
17
. The pressure chamber on the piston rod side of the actuating cylinder
17
is connected to the pressure connection of the pump control valve
18
. The piston slide of the pump control valve
18
is acted on with the effect of connecting the cylinder connection to the pressure connection of the control pressure and with the effect of connecting the cylinder connection to the tank connection by a first compression spring, set to a fixed value, and by a second compression spring whose prestress changes with the position of the piston and the piston rod of the actuating cylinder
17
. The piston and piston rod of the actuating cylinder
17
therefore in each case assume a position such that the force generated as a result of the applied control pressure and the force generated by the springs maintain the equilibrium at the piston of the pump control valve
18
. In this way, a specific absorption volume of the hydraulic motor
12
can be set by the control pressure.
The source for the pressure medium which is fed to the hydraulic motor
12
is a displacement pump
25
, which takes hydraulic oil from a tank
26
and discharges it into a feed line
27
. The displacement pump
25
is provided with a pressure controller
28
, and therefore, when the pressure set on the pressure regulator
28
is reached in the feed line
27
, pivots back to a swept volume which is sufficient to maintain the set pressure in the feed line
27
. In order to safeguard the entire control arrangement against excessively high pressures, a pressure limiting valve
29
is connected to the feed line
27
. The maximum swept volume of the displacement pump is designed in such a way that said pump is not pivoted as far as the stop even if, taking account of a simultaneous actuation of a plurality of hydraulic loads, the maximum quantity of pressure medium is requested.
The rotational speed at which the hydraulic motor
12
rotates and the direction of rotation can be controlled by a proportionally adjustable directional control valve
35
. This is spring-centered into a mid-position and can be actuated hydraulically. It has a total of six connections, namely a feed connection
36
, to which pressure medium can flow from the feed line
27
via a pressure compensator
37
, an outlet connection
38
, which is connected directly to a tank line
39
, a second outlet connection
40
, which is connected via a brake valve
41
to the tank line
39
, a first load connection
42
, which is connected via a load line
43
to the motor connection
21
, a second load connection
44
, which is connected via a load line
45
to the motor connection
22
, and a brake connection
46
, via which pressure medium can be applied to the annular chamber
15
of the hydraulic cylinder
14
.
In the spring-centered mid-position of the directional control valve
35
, its connections
36
,
40
and
44
are blocked off. The connections
42
and
46
are connected to the connection
38
and therefore to the tank
26
. By applying a control pressure to a first control chamber
47
, the valve piston of the directional control valve
35
is displaced to a different extent, depending on the level of the control pressure, into a first operating position, in which the outlet connection
38
is blocked off. The load connection
42
and the brake connection
46
are jointly connected to the feed connection
36
via a feed metering diaphragm
48
, whose opening cross section depends on the extent of the displacement of the valve piston. The load connection
44
is connected via an outlet restrictor
49
to the outlet connection
40
. If the control chamber
47
is relieved of pressure, and if a second control chamber
50
has a control pressure applied to it, then the valve piston of the directional control valve
35
passes to a different extent from the mid-position into a second operating position, in which the load connection
42
is connected in an unrestricted manner to the outlet connection
38
. The brake connection and the other load connection
44
are jointly connected to the feed connection
36
via the feed metering diaphragm
48
. The outlet connection
40
is blocked off. The maximum displacement travel of the valve piston in the two opposite directions is limited by adjustable stops
51
.
According to the connections outlined, the pressure compensator
37
is arranged between the various connections of the directional control valve
35
in the two operating positions of the latter, in each case upstream of the feed metering diaphragm
48
. The control piston of the pressure compensator
37
is acted on in the closing direction by the pressure upstream of the feed metering diaphragm and in the opening direction by a compression spring
52
and by a pressure which is applied via a control line
53
, which is connected to the brake connection of the directional control valve and therefore in each case to the load connection
42
or
44
of the directional control valve
35
in the flow to the hydraulic motor
12
. The pressure is therefore in each case equal to the pressure downstream of the feed metering diaphragm
48
. The pressure compensator
37
therefore controls a specific pressure difference, equivalent to the force of the spring
52
, across the feed metering diaphragm
48
. The quantity of pressure medium flowing via the feed metering diaphragm
48
therefore depends only on the opening cross section of the feed metering diaphragm and is independent of the load pressure and of the pump pressure.
The control piston of the brake valve
41
is acted on in the opening direction by the pressure present on the load connection
42
of the directional control valve
44
and therefore also present in the load line
43
and at the motor connection
21
, and is acted on in the closing direction by the force of a compression spring
54
and by a pilot control pressure applied via a control line
55
, which is constantly in the region of
40
bar, for example. The two pressures act on equally large areas, so that under a pulling load, the brake valve
41
, together with the restrictor
49
, restricts the outflow of pressure medium from the hydraulic motor
12
via the load line
45
in each case to such a great extent that, in the load line
43
, a pressure is built up which produces a force on the control piston of the brake valve which maintains the equilibrium of the force of the compression spring
54
and the force generated by the pilot control pressure. The rotational speed of the hydraulic motor
12
is therefore also determined by the opening cross section of the feed metering diaphragm
48
when under a pulling load. In addition, the pressure on the brake connection
46
of the directional control valve
35
is so high under a pulling load that the brake
13
remains released.
Arranged between the two load lines
43
and
45
is a pressure limiting valve
60
, which is set to a pressure which is about 10-20 bar above the pressure controlled by the displacement pump
25
, but below the set pressure of the pressure limiting valve
29
.
The directional control valve
35
, the pressure compensator
37
, the brake valve
41
and the pressure limiting valve
60
are accommodated in a valve plate
61
. Built up on the latter is a pilot controller
65
, via which a bypass line
66
which can be blocked off leads, which originates from the feed line
27
upstream of the pressure compensator
37
and opens into the load line
45
, that is to say circumvents the pressure compensator
37
and the directional control valve
35
. Located in the bypass line
66
is a nozzle
67
, which is located in the plate
61
and through which the quantity of pressure medium which can flow to the hydraulic motor
12
via the bypass line
66
is limited to about 10% of the quantity of pressure medium which flows to the hydraulic motor
12
via the directional control valve
35
when the feed metering diaphragm
48
is at its maximum opening.
The pilot controller
65
contains two pressure reducing valves
68
and
69
, a directional control valve
70
, a nonreturn valve
71
, various changeover valves
72
,
73
,
74
and
75
, two damping nozzles
76
, two relief nozzles
77
and various ducts for connecting the valves to one another. The nonreturn valve
71
is in the bypass line
66
and blocks toward the feed line
27
. Downstream of the nonreturn valve
71
, the pressure reducing valve
68
is connected to the bypass line
66
by its pressure connection. A relief connection of the pressure control valve
68
is connected to a leakage duct
78
. The pressure reducing valve
68
is set to a fixed value and, at its control output and in a pilot control pressure supply duct
79
, to which the control line
55
leading to the brake valve
41
is also connected, for example controls the aforementioned pressure at the level of 40 bar. The second pressure reducing valve
69
, which is connected by its pressure connection to the duct
79
, by its relief connection to the duct
78
and by its control output to a pilot control pressure duct
80
, can be adjusted by pivoting a control lever
81
from a neutral position. The pivot axis of the control lever
81
is designated by
82
. Fixed to the control lever is a control disk
83
having a control cam on which an actuating plunger
84
of the pressure reducing valve
69
bears. The control cam is configured such that when the control lever is pivoted from the neutral position, first of all the pressure reducing valve
69
is adjusted in the same way, irrespective of the pivoting direction. To be specific, the pilot control pressure in the duct
80
increases continuously, starting from a pivoting angle of about 8 degrees up to the pivoting angle of 45 degrees, even if not necessarily with the same slope everywhere. The pivoting angle of the control lever
81
is limited to about 50 degrees for the pivoting in one direction. In this direction, the control lever is pivoted for the purpose of easing, that is to say for unwinding the hawser from the winch
10
. Pivoting the control lever in the other direction is carried out for the purpose of hoisting, that is to say when the hawser is to be wound up on the winch
10
. In this case, both when being pivoted in the direction of easing and when being pivoted in the direction of hoisting, the control lever
81
pivots back into its neutral position again, because of a restoring device acting on it, when it is released. In the hoisting direction, however, the control lever can be pivoted up to a pivoting angle of about 100 degrees, remaining in the position assumed by it when it is pivoted over about 54 degrees, even when it is released. In this range, the winch
10
is operated in the mooring mode. The three angular ranges of easing, hoisting and mooring are indicated hatched in FIG.
1
and provided with reference numbers
85
for easing,
86
for hoisting and
87
for mooring. Here, the control disk
83
is configured such that in the mooring angle range
87
the pressure in the duct
80
decreases as the pivoting angle of the control lever
81
increases.
The directional control valve
70
is actuated mechanically by the control lever
81
. Its movable valve element is constructed as a rotary slider
181
(see FIGS.
9
and
10
), whose axis of rotation coincides with the axis
82
of the control lever
81
. It can assume a total of four functionally distinguishable switching positions and has
7
connections, of which two connections
88
and
89
are downstream of the nonreturn valve
71
and upstream of the nozzle
67
in the bypass line
66
. The pilot control pressure duct
80
leads to one connection
90
. One connection
91
is connected to the leakage duct
78
. The three remaining connections
92
,
93
and
94
each lead to a first input of a changeover valve
72
,
73
and
74
, respectively. The second input of the changeover valve
74
is connected to the brake connection
46
of the directional control valve
35
. A line
95
leads from the output of this changeover valve to the annular chamber
15
of the hydraulic cylinder
14
. The second input of each of the two changeover valves
72
and
73
is respectively connected to an external connection
95
, which is closed in the present case but offers the possibility of controlling the winch with a second pilot controller, which is arranged at a distance from the block comprising the plate
61
and the pilot controller
65
. For the case of this remote control, and for the case of small pilot control pressures, the line between the connection
46
of the directional control valve
35
and the changeover valve
74
is needed, since the annular chamber
15
of the hydraulic cylinder
14
can then be pressurized via this line. From the output of the changeover valve
72
, a control line
96
leads via a damping nozzle
76
to the control chamber
50
, and from the output of the changeover valve
73
, likewise via a damping nozzle
76
of a control line
97
leads to the control chamber
47
of the directional control valve
35
. The changeover valve
75
is connected by one input to the output of the changeover valve
72
and by its other input to the output of the changeover valve
73
. Its output is connected via a control line
98
to the control input
16
of the hydraulic motor
12
.
In the neutral position of the control lever
81
, the directional control valve
70
assumes a position in which the connections
88
,
89
and
90
are blocked off and the other connections are connected to the tank duct
78
. The bypass line
66
is therefore blocked. The control lines
95
,
96
,
97
and
98
are relieved of pressure in relation to the duct
78
. The directional control valve
35
is therefore in its midposition. The hydraulic motor
12
is at maximum absorption volume. The brake
13
is engaged.
The control lever is then adjusted into the angle range
85
for easing. As a result, the directional control valve
70
moves into a switching position, in which the connections
89
and
94
, the connections
90
and
93
and the connections
91
and
92
are respectively connected to each other. Therefore, the control chamber
47
of the directional control valve
35
has a control pressure applied to it via the connections
90
and
93
and the changeover valve
73
and the control line
97
. This control pressure is also present on the control input
16
of the hydraulic motor
12
via the changeover valve
75
and the control line
98
. The control chamber
50
of the directional control valve
35
is relieved of pressure via the control line
96
, the changeover valve
72
and the connections
91
and
92
of the directional control valve
70
, and via the one relief nozzle
77
. The directional control valve
35
is therefore moved into a position in which the feed connection
36
is connected via the feed metering diaphragm
48
to the load connection
42
and to the brake connection
46
. In the load line
43
and in the feed line
27
, a pressure builds up which, via the changeover valve
74
, is also present in the annular chamber
15
of the hydraulic cylinder
14
and is finally sufficient to release the brake. Pressure medium delivered by the hydraulic pump
25
can then flow via the feed line
27
, the pressure compensator
37
, the directional control valve
35
and the load line
43
to the hydraulic motor
12
and, from there, via the load line
25
, the restrictor opening
49
of the directional control valve
35
and via the brake valve
41
, to the tank
26
. The hawser is unwound from the winch
10
. In the process, even when a pulling load hangs on the hawser, the brake valve
41
ensures that the outflow of pressure medium from the hydraulic motor
12
to the tank can only take place in a restricted manner so that a specific pressure is maintained in the load line
43
. This pressure is sufficient to hold the brake
13
released. In addition, the speed at which the hawser is paid out is determined only by the control pressure, which depends on the deflection of the control lever
81
. In this case, the speed of the winch
10
is influenced in two ways. Up to about a deflection angle of 25 degrees, only the directional control valve
35
is adjusted, but not the hydraulic motor
12
. The latter remains at the maximum absorption volume and maximum torque. The torque is indicated in
FIG. 1
by the radial extent of the fields
85
,
86
and
87
. After a deflection of the control lever
81
of
25
degrees, the directional control valve
35
is completely open. During further deflection of the control lever
81
, the absorption volume of the hydraulic motor
12
is then reduced, as a result of which its rotational speed is increased, but its torque is reduced. This is indicated by the decreasing radial extent of the field
85
in FIG.
1
.
If, starting from the neutral position shown, the control lever
81
is pivoted into the hoisting angle range
86
, then the directional control valve
70
comes into a position in which the connections
89
and
94
are again connected to each other. However, the connection
90
is now connected to the connection
92
and the connection
91
to the connection
93
. The control chamber
47
is therefore depressurized, and the control chamber
50
of the directional control valve
35
has applied to it a pilot control pressure dependent on the deflection angle of the control lever
81
. This pressure is also present on the control input
16
of the hydraulic motor
12
. The directional control valve moves into its second operating position, in which pressure medium delivered by the displacement pump
25
can flow via the feed line
27
, the pressure compensator
37
, the connections
36
and
44
with the feed metering diaphragm
48
located between them, and via the load line
45
, to the hydraulic motor
12
. The outflow of the pressure medium from the hydraulic motor
12
takes place via the load line
43
and the connections
42
and
38
of the directional control valve
35
to the tank
26
. In the load line
45
and in the feed line
27
, a load-dependent pressure is built up which is sufficient to release the brake
13
. The hawser is then wound up on the winch
10
.
If the control lever
81
is pivoted still further into the mooring angle range
87
, then the directional control valve
70
passes into a switching position in which the connections
88
and
94
are connected to the connection
89
. Accordingly, the bypass line
66
is open for the flow of pressure medium, and the annular space
15
of the hydraulic cylinder
14
is connected to the bypass line downstream of the nonreturn valve
71
. The connection
91
of the directional control valve
70
is blocked off. The connections
92
and
93
are connected to the connection
90
, and therefore to the control output on the pressure reducing valve
69
. The same pilot control pressure is therefore present in both the control chambers of the directional control valve
35
, so that the latter returns into the mid-position on account of its spring centering. The pilot control pressure is also present on the inlet
16
of the hydraulic motor
12
. In this case, the control cam of the control disk
83
is configured in such a way that, at the start of the mooring angle range, the pilot control pressure is so high that the hydraulic motor is set to its minimum absorption volume. The torque that can be exerted by the hydraulic motor
12
is therefore also a minimum. As the deflection of the control lever
81
increases in the mooring angle range
87
, the pilot control pressure decreases continuously, so that the absorption volume and therefore the torque that can be exerted by the hydraulic motor
12
increases continuously. This is beneficial in terms of working physiology.
In the mooring angle range
87
, pressure medium can still flow to the connection
22
of the hydraulic motor
12
only via the bypass line
66
. This feed flow is limited by the nozzle
67
, so that in the mooring mode, the rotational speed of the hydraulic motor and therefore the speed with which the hawser is wound up is limited. This is important for operational safety. This is because, since the control lever
81
in the mooring angle range
87
maintains its position, even without the action of an external force, there is the possibility that a person will firstly place the control lever in the mooring angle range and then do something with the hawser or stay in the area of the hawser. As a result of the nozzle
67
, the speed at which the hawser is moved is now limited to a low speed. Even if the hawser breaks, the speed at which the hawser is then wound up is low, because of the nozzle
67
, even though it may be somewhat higher than under load.
The control lever
81
is fixed to a shaft
183
which projects from the housing
101
of the pilot controller
65
and with which, as
FIG. 2
reveals, within the housing
101
a cam disk
102
with a cam track
104
cooperating with a restoring device
103
, and the control disk
83
axially immediately adjacent to the cam disk
102
and having a control cam
105
cooperating with the plunger
84
of the pressure reducing valve
69
are coupled in a rotationally secure manner. The cam track
104
and the control cam
105
are in each case part-cylindrical surfaces which extend axially over a certain distance. The cam disk
102
and the control disk
83
are located in a relatively large cavity
99
in the housing
101
, into which there open two housing bores
106
and
107
which are located diametrically opposite but, in accordance with the axial offset of the cam disk
102
and control disk
83
, are likewise offset axially in relation to each other. The housing bore
106
accommodates the parts of the restoring device
103
. The pressure reducing valve
69
is inserted into the housing bore
107
.
This pressure reducing valve
69
can be adjusted from the outside in such a way that a quite specific pilot control pressure prevails in the duct
80
at a selected deflection angle of the control lever
81
. At this selected deflection angle, the intention is for the directional control valve
35
to be fully open and for the displacement of the hydraulic motor
12
to begin. For the purpose of adjustment, the pressure reducing valve
69
has a control cartridge
108
, which is screwed into the housing bore
107
from the externally open end of the latter. The control cartridge
108
is stepped three times on the outside and, at each step, has a seal
109
,
110
and
111
. Formed between the seal
109
with the smallest diameter and the middle seal
110
, between the control cartridge
108
and the housing
110
, is an annular chamber, which is part of the control pressure supply duct designated by
79
in FIG.
1
and in which there prevails the pressure regulated by the pressure reducing valve
68
at the level of 40 bar. Axially between the two seals
110
and
111
, on the outside of the control cartridge
108
, there is a further annular chamber, which belongs to the pilot control pressure duct
80
from
FIG. 1. A
further annular chamber between the control cartridge
108
and the housing
101
is created in front of the seal
109
, this annular chamber belonging to the leakage duct
78
from FIG.
1
.
The central passage
112
through the control cartridge
108
has sections lying axially one behind another with different cross sections. A bore section with the smallest diameter is located axially approximately between the seals
109
and
110
and, via two radial holes
113
, is open to the annular chamber
79
. It merges outward into a bore section which is somewhat larger and partially provided with an internal thread and from which there lead radial holes
114
which open into the annular chamber
80
. Screwed into the bore section is a grub screw
115
, by means of which the aforementioned bore sections are closed off to the outside. On the other side of the grub screw
115
, the passage is formed as an internal polygon, on which a tool can be attached for the purpose of rotating and therefore for the purpose of axial adjustment of the control cartridge
108
. The bore section into which the radial holes
113
open merges inward into an accommodation chamber
116
, which is again stepped and from which radial holes
117
lead into the annular chamber
78
. Inserted into this accommodation chamber
116
is a guide bush
118
for the plunger
84
of the pressure regulating valve
69
, said guide bush being captively secured therein by a grub screw
121
. The guide bush has radial holes
119
, via which, together with an annular chamber placed between the control cartridge
108
and the guide bush
118
, a spring chamber
120
formed between the control cartridge
108
, the guide bush
118
and the plunger
84
is connected to the annular chamber
78
and therefore to the tank.
The passage section into which the radial holes
113
open is used as a guide bore for a control piston
125
and, together with the control piston, controls the connections between the various annular chambers
78
,
79
and
80
. The edges between the radial holes
113
and the bore section, on the one hand, and the edge between the bore section and the relatively large spring chamber
120
, on the other hand, form the control edges in this case. The control piston
125
is a hollow piston having an axial blind bore
126
, which is open toward the radial holes
114
and is connected via a plurality of radial holes
127
to the outer side of the control piston. The radial holes
127
merge on the outside into an annular groove
128
. The axial extent of the annular groove, including the radial holes
127
, is slightly smaller than the clear axial spacing between the control edges on the control cartridge
108
, so that it is possible to separate the blind bore
26
with a positive overlap both from the radial holes
113
and from the spring chamber
120
. The control piston
125
extends through the spring chamber
120
and projects with a head
129
into a blind bore
130
in the plunger
84
. With the head
129
, it engages behind a disk
131
, which is arranged between the plunger
84
and a spring plate
132
, and holds the head
129
in the manner of a slotted securing ring. A restoring spring
133
accommodated by the spring chamber
120
and intended for the plunger
84
is supported at one end on the control cartridge
108
and at the other end, via the spring plate
132
and the disk
131
, on the plunger
84
and presses the plunger against the control cam
105
. Also accommodated by the spring chamber
120
is a control spring
134
, which is clamped in between a spring plate
135
bearing on a shoulder of the control piston
125
and the spring plate
132
, and which ensures that, in the rest position shown of the plunger
84
, the head
129
of the latter bears on the disk
131
.
The pressure limiting valve
69
is arranged with respect to the axis of the control lever
81
such that the axis of the plunger
84
intersects the axis
82
of the control lever
81
at right angles. Starting from a central neutral line, in which its distance from the axis
82
is a minimum and on which the plunger
84
bears in the neutral position of the control lever
81
, the control cam
105
is initially of the same shape on both sides. Its distance from the axis
82
increases continuously. Toward one side, the control cam
105
ends in a surface section
140
which extends radially outward, for which the plunger
84
acts as a stop and which therefore limits the pivoting angle of the control lever
81
in one direction. In the other direction, approximately at the same distance from the center line as the control cam section
140
, there is a small elevation
141
, on account of which, during the pivoting of the control lever
81
, the torque rises briefly and it is therefore indicated to the operator that a change is being made from one operating range into a second operating range. Following the elevation
141
,the distance of the control cam from the axis
82
decreases in the control cam section
142
.
In the neutral position of the control cam
105
shown in
FIG. 2
, the plunger
84
and, with it, the control piston
125
of the pressure reducing valve
69
is in a position in which the annular chamber
80
has a fluidic connection to the annular chamber
78
via the blind hole
126
, the radial holes
127
, the spring chamber
120
, the radial holes
119
and the radial holes
117
. If the control lever is then deflected, then the plunger
84
is displaced into the control cartridge
108
. Via the control spring
134
, the control piston
125
is carried with it, so that the connection between the blind hole
126
and the annular chamber
78
is interrupted, and a connection between the blind hole
126
and the annular chamber
79
is opened. From the latter, pressure medium can then flow through the control piston
125
into the annular chamber
80
and onward to one or both control chambers
47
and
50
of the directional control valve
35
. A pressure is built up by means of which the control piston
125
is pushed back against the control spring
134
until equilibrium prevails between the hydraulic force and the spring force. The control piston
125
then assumes a control position. The level of the pilot control pressure in the annular chamber
80
is in this case determined by the prestress which the control spring
134
has in the given position of the plunger
84
in the control position of the control piston
125
. This prestress, and therefore also the pilot control pressure in the given plunger position, can be adjusted. For this purpose, the control cartridge
108
is screwed somewhat into the housing
101
or somewhat out of the housing
101
. As a result, the control position of the control piston
125
also changes and, therefore, at a given plunger position, the prestress of the control spring
134
and therefore the level of the pilot control pressure. The pilot control pressure increases as a result of the control cartridge
108
being screwed in, and decreases as a result of said control cartridge being screwed out. For a selected position of the control lever
81
, a specific pilot control pressure can therefore be adjusted. Away from the selected position of the control lever
81
, on the other hand, specimen scatter may still occur, since the stiffness of the control springs used in different specimens varies.
The restoring device
103
comprises a pressure piece
145
which is guided in the housing bore
106
by a cylindrical section
146
and by a double flat
147
, whose flat faces are aligned perpendicular to the axis
82
, said pressure piece
145
projecting into the hollow chamber
99
and being pressed against the restoring cam track
104
with its end
148
extending parallel to the axis
82
. A pressing force is exerted over the entire pivoting range by a restoring spring
149
. In addition, in the mooring angle range designated by
87
in
FIG. 1
, a further pressure spring
150
acts. The springs are located in a spring chamber between the pressure piece
145
and a closing screw
151
screwed into the housing bore
106
. In order to accommodate springs of the necessary length, the pressure piece
146
has a blind hole
152
which is open toward the closing screw
151
and between whose base and the closing screw
151
the restoring spring
149
is clamped. Within the restoring spring
149
there is a bush
153
, which is likewise open to the closing screw
151
and in whose blind hole the pressing spring
150
is accommodated for the major part. In the position shown in
FIG. 2
of the pressure piece
145
, in which the latter is at its greatest distance from the closing screw
151
, the pressing spring
150
is completely unstressed. The pressing spring
150
becomes effective only after a specific travel of the pressure piece
145
toward the closing screw
151
.
Within the guide section
146
, the pressure piece
145
has, on its outer side, two diametrically opposite, axially extending grooves
154
and
155
, which are of different lengths but begin at the same distance from that end of the pressure piece
145
which faces the closing screw
151
. A pin
156
, which is held in the housing
101
, engages in the groove
154
with slight play. The pressure piece
145
is secured against rotation by the pin
156
. The groove
154
is sufficiently long for the axial movement of the pressure piece
145
not to be limited by the pin
156
.
The cam track
104
is substantially composed of four flat cam sections which can be distinguished from one another. One cam section
160
extends over 180 degrees around the axis
82
and is circularly cylindrically curved, that is to say has the same distance from the axis
82
everywhere. In the neutral position of the control lever
81
and therefore of the cam track
104
, as shown in
FIG. 2
, the axial plane
164
which goes through the axis
82
and the ends of the cam section
160
is perpendicular to the axis of the pressure piece
145
. Between the two ends of the cam section
160
there are three flat, level cam sections
161
,
162
and
163
, which run at an angle to one another. The central cam section
161
of these three cam sections extends at a short distance from the plane
164
, parallel to the latter. The two cam sections
162
and
163
run at an angle to the cam section
161
toward the cam section
160
.
That end
148
of the pressure piece
145
which faces the cam track
104
has two level surface sections
168
and
169
which are aligned with each other and perpendicular to the axis of the pressure piece
145
, and extend inward to different extents from the round side surface sections of the double flat
147
. In this case, the surface section
169
is substantially longer than the surface section
168
. Between these two surface sections, a continuous recess
170
perpendicular to the flat sides is introduced into the end
148
and, starting from the inner end of the surface section
168
, is bounded by a uniformly curved surface
171
, whose curvature is equal to the curvature of the cam section
160
of the cam track
104
. The surface
171
is adjoined by a channel
172
, which is located centrally in the end of the pressure piece. One side of the channel
171
merges into the flat surface section
169
at a stop face
173
.
Into the channel
172
there opens an axial bore
174
which passes through the pressure piece
145
and in whose extension the base of the bush
153
also has an axial bore
175
. The spring chamber that accommodates the springs
149
and
150
is therefore continuously connected fluidically to the hollow chamber
99
in the housing
101
. The hollow chamber
99
is in turn located in the leakage line
78
.
To ease, that is to say to unwind the hawser from the winch
10
, the control lever
81
is pivoted into the easing angle range
85
according to FIG.
1
. As a result, the control disk
83
and the cam disk
102
are rotated in the clockwise direction in the view of FIG.
2
. In the process, firstly the corner between the cam sections
161
and
163
slides along on the surface section
169
of the pressure piece
145
. As a result, the pressure piece is displaced in the direction of the closing screw
151
, so that the prestress of the restoring spring
149
is increased continuously. If the control lever is released at any point, then the pressure piece
145
and the control lever return into the neutral position shown in
FIG. 2
, under the action of the restoring spring
149
. However, if the control lever
81
is pivoted still further in the direction of easing, then the cam section
163
finally rests flat on the surface section
169
of the pressure piece
145
. During a further deflection of the control lever, the point of action of the pressure piece
145
moves abruptly further away from the axis
82
of the control lever toward the corner between the cam section
163
and the cam section
160
. This manifests itself in a steep rise in the torque exerted by the restoring device
103
on the control lever. This indicates to the operator that the directional control valve
35
from
FIG. 1
is now completely open and, during the further pivoting of the control lever
81
, the absorption volume of the hydraulic motor
12
will be reduced. When the cam sections
163
and
169
rest flat on each other, then the pilot control pressure should have the specific level which is set by adjusting the pressure regulating valve
69
. During further deflection, the corner between the cam section
160
and the cam section
163
then slides along on the surface section
169
, as a result of which the pressure piece
145
is displaced further in the direction of the closing screw and the restoring spring
149
is prestressed further. Finally, an end position is reached as shown in FIG.
3
. The control disk
83
has struck the plunger
84
of the pressure reducing valve
69
with the section
140
of the control cam
105
and can no longer be rotated further. If the control lever is released, it returns into its neutral position again under the action of the restoring device
103
.
If the control lever
81
is pivoted from its neutral position, in which, as
FIG. 2
reveals, the cam section
161
of the cam track
104
and the surface sections
168
and
169
of the pressure piece
145
bear flat on one another, in the direction of hoisting, then the control disk
83
and the cam disk
102
are rotated in the counterclockwise direction in the view of FIG.
2
. The pressure piece
145
acts on the cam track
104
at the corner between the cam sections
161
and
162
, as shown in FIG.
4
. During the further pivoting of the control lever
81
, the cam section
162
of the cam track
102
finally comes to bear flat on the surface section
168
of the pressure piece
145
. This state is shown in FIG.
5
. During further pivoting of the control lever
81
, the operator notices a sharp rise in the necessary actuating force and is therefore given an indication that the absorption volume of the hydraulic motor
12
is then being adjusted. Finally, the surface
168
of the pressure piece
145
bears on the corner between the cam section
162
and the cam section
160
of the cam track
104
, as
FIG. 6
shows. There, the control lever
81
has already been rotated to such an extent that the plunger
84
of the pressure reducing valve
69
has struck the elevation
141
on the control cam
105
. This manifests itself to the operator in a further pressure point during the pivoting of the control lever
81
. This indicates that, during further pivoting of the control lever, the hoisting angle range
86
will be left. When the control lever
81
is released in the hoisting angle range, the restoring device
103
is able to return the control lever into its neutral position again, since any further deflection of the control lever in this range is associated with an increase in the prestress of the restoring spring
149
.
If the control lever is pivoted further, with the increased expenditure of effort, which is needed for the plunger
84
to overcome the elevation
141
, then, first of all, the edge between the two cam sections
168
and
160
and, to an ever increasing extent, the cam section
160
passes into the region of the recess
170
in the pressure piece
145
, where the cam section
160
bears on the surface
171
of the recess
170
. In the positions shown in
FIG. 6
of the individual components, the pressure piece
145
has been displaced to such an extent in the direction of the closing screw
151
that the pressing spring
150
is still just located in an unstressed condition between the pressure piece and the closing screw. During the further rotation of the cam disk
102
in the counterclockwise direction, the pressure piece is displaced still further toward the closing screw and, as a result, the pressing spring
150
is stressed, until finally the edge between the cam sections
160
and
168
of the cam track
104
passes into the region of the recess
170
in the pressure piece
145
.
FIG. 7
shows a state in which the plunger
84
has just overcome the elevation
141
on the control cam
105
, and the cam section
160
of the cam track
104
has dipped slightly into the recess
170
and bears on the surface
171
there. The pressure piece
145
is then pressed against the cam section
160
of the cam track
104
by the force of the spring
149
and additionally by the force of the spring
150
. Since the curvatures of the cam section
160
and of the surface
171
are the same, further pivoting of the control lever no longer leads to increased prestressing of the springs
149
and
150
. These therefore no longer exert any restoring force on the control lever. The control lever is located in the mooring angle range
87
. The distance between the hoisting angle range and the mooring angle range is about 10 degrees, in which the plunger
84
overcomes the elevation
141
on the control cam
105
. The increase in the pilot control pressure which occurs in the process has no effect on the directional control valve
35
or the hydraulic motor
12
, since at the end of the hoisting angle range, the directional control valve
35
is fully open and the hydraulic motor
12
is set to its smallest absorption volume. At the end of the mooring angle range
87
from
FIG. 1
, the cam section
168
of the cam track
104
strikes the stop face
173
of the recess
170
, as shown in FIG.
8
. Further pivoting of the control lever
81
is no longer possible.
On the other side of the elevation
141
, the control cam
105
in the region
142
is shaped such that with further deflection of the control lever, the plunger
84
emerges further and further from the guide bush
118
, so that the springs of the pressure reducing valve
69
exert a torque on the control lever
81
with the effect of further deflection. The frictional forces between the pressure piece
145
and the cam disk
102
and between the plunger
84
and the control disk
83
are so high, however, that the control lever maintains its position in the mooring angle range even when it is released.
FIG. 8
also reveals in particular the effect of the channel
172
in the recess
170
in the pressure piece
145
. By means of this channel, an exchange of pressure medium between the spring chamber with the springs
149
and
150
and the hollow chamber
99
in the housing
101
is ensured in a simple way even if the control lever
81
has been pivoted as far as the end of the mooring angle range.
The groove
155
in the pressure piece
145
is of no significance for a control arrangement with a mooring mode of the winch. However, not every winch is also provided for the mooring mode. The groove
155
permits the pressure piece
145
also to be used for a winch without the mooring mode. For this purpose only, as compared with the state shown in
FIG. 2
, it is incorporated in the housing
101
rotated through 180 degrees about its longitudinal axis. The pin
156
then engages in the groove
155
. Because of the shortness of this groove, the pin
156
limits the travel by which the pressure piece
145
can be displaced toward the closing screw
151
. This therefore provides a stop for the control lever at the end of the hoisting angle range. The pin
156
can likewise become effective at the end of the easing angle range. Depending on the length of the groove
155
, however, it is possible for the plunger
84
already to have struck the surface
140
of the control cam
105
previously. The groove
155
therefore permits a pilot controller for a winch without the mooring mode and a winch with the mooring mode to be constructed with the same pressure piece
145
. Likewise, an existing winch can be converted.
FIG. 9
reveals that the housing
101
has a valve bore
180
, in which the movable control element of the directional control valve
70
, formed as a rotary slide
181
, is located and into which the various lines or line sections which lead to the directional control valve according to FIG.
1
and which are formed as bores in the housing
101
open, as will be described further using FIG.
10
. At its one end, the valve bore
180
widens to form the hollow chamber
99
, in which the cam disk
102
and the control disk
83
are located. The cam disk
102
and control disk
83
are produced in one piece with the rotary slide
181
. The hollow chamber
99
is closed off to the outside by a housing cover
182
, in which, centrally and aligned with the axis of the rotary slide
181
, the shaft
183
is rotatably mounted, projects beyond the cover
182
and on which the control lever
81
is fixed to the projecting section. The shaft ends within the housing
101
in a stop collar
184
, which strikes a step in the cover
182
and prevents the shaft
183
becoming detached from the housing
101
. Shaft
183
and rotary slide
181
are coupled to each other in a rotationally secure manner by two pins
185
, each of which engages axially in a hole in the rotary slide and the shaft. In a central blind hole in the shaft
183
, which is open toward the rotary slide
181
, there is accommodated a compression spring
186
, which is supported on the base of the blind hole and, via a ball
187
, on the rotary slide
181
and urges the shaft
183
and rotary slide
181
apart axially, so that at one end the shaft
183
bears on the cover
182
and the rotary slide
181
via the cam disk
102
on the housing
101
, and the two parts assume largely fixed axial positions.
Opposite the hollow chamber
99
, the valve bore
180
opens into an end chamber
188
, which has an enlarged radius and is closed off to the outside by a closure screw
189
. The hollow chamber
99
and the chamber
188
, as indicated by the dashed line provided with the reference number
78
from
FIG. 1
, are connected to each other and to the leakage oil line
19
.
From the side facing the closure screw
189
, a stepped blind bore
190
, into which the pressure reducing valve
68
is inserted, is introduced into the rotary slide
181
. Axially upstream of the pressure reducing valve
68
, the blind bore
190
forms an axial control connection
191
of the pressure reducing valve
68
, into which the latter regulates a constant pilot control pressure of 40 bar. An annular chamber
192
between the pressure reducing valve
68
and the rotary slide
181
, said chamber being connected via two axial holes
193
to the chamber
188
, forms the outlet connection of the pressure reducing valve
68
. A second annular chamber
194
is the feed connection of the pressure reducing valve.
In the developed representation of the rotary slide
181
according to
FIG. 10
, dashed lines represent the openings of various holes in the housing
101
, which are shown partially three-dimensionally in FIG.
9
and partially by dashed lines and which represent the various connections
88
to
94
of the directional control valve
70
. The connection
90
opens into the valve bore
180
at a point at which an annular groove
201
runs around the rotary slide
181
. In a line, axially on one side of the connection
90
and at a distance from the latter, the connection
92
opens into the valve bore
180
and, on the other side, the connection
93
opens into the valve bore
180
. Axially at the level of the connection
92
there are in the rotary slide
181
two equally long finite grooves
202
and
203
, which are connected to the annular groove
201
via axial grooves. Between the two grooves
202
and
203
there are shorter grooves
204
and
205
, which in each case have a fluidic connection via a radial hole
206
to a central axial bore
207
, and via a further radial hole
208
in the rotary slide
181
to the hollow chamber
99
and therefore to the leakage line.
Point-symmetrical in relation to the grooves
204
and
205
with respect to the connection
90
, axially at the level of the connection
93
, there are two grooves
209
and
210
, which in turn are connected via radial holes
206
to the axial bore
207
in the rotary slide
181
. Between the two grooves
209
and
210
there are in each case two grooves
211
and
212
and, respectively,
213
and
214
which, like the grooves
202
and
203
, are connected to the annular groove
201
via axial grooves. Only the annular groove
201
and the grooves
202
,
204
,
209
,
211
and
213
are important for the directional control functions of the valve
70
. The other grooves are used for radial pressure equalization on the rotary slide
181
.
In
FIG. 10
, the rotary slide
181
is shown in a position which it assumes in the neutral position of the control lever
81
. It can be seen that the grooves
204
and
209
cover the connections
92
and
93
, so that these two connections are relieved of pressure. If, then, for the hoisting operating mode of the winch, the rotary slide is moved downward in the view according to
FIG. 10
, then the connection
92
will be isolated from the groove
204
and, after a short distance, comes to overlap the groove
202
. The connection
92
is therefore then connected to the control output of the pressure reducing valve
69
. The connection
93
initially remains overlapping the groove
209
and is therefore relieved of pressure. This configuration is maintained as far as the end of the hoisting angle range
86
from FIG.
1
. The connection
93
then passes out of the range of the groove
209
and comes to overlap the groove
213
. The same pilot control pressure is then present on said connection
93
as on the connection
92
.
When the control lever is pivoted in the easing direction, the connection
92
continues to overlap the groove
204
, while the connection
93
comes to overlap the groove
211
.
In addition to the grooves
202
to
205
, the rotary slide
181
also has a circumferential groove
215
from which, radial holes
216
start and open into the blind bore
191
upstream of the pressure reducing valve
68
inserted into the rotary slide
181
, that is to say are connected to the control output of the pressure reducing valve
68
. The groove
215
and the radial holes
216
are therefore located in the duct
79
according to
FIG. 1
, via which a largely constant supply control pressure is present on the feed connection of the pressure reducing valve
69
.
In the region of the connection
89
, a groove
217
runs around the rotary slide
181
and, via axial grooves, is connected to two mutually diametrically opposite short grooves
218
. If the control lever is pivoted as far as the mooring angle range, the grooves
218
come to overlap with the connections
88
, so that pressure medium can flow via the bypass line
66
from FIG.
1
. The grooves
218
and therefore the groove
217
are connected via a further annular groove
219
to two mutually diametrically opposite grooves
220
which the connection
94
comes to overlap when the control lever is pivoted out of the neutral position, so that the annular chamber
15
of the cylinder
14
from
FIG. 1
can have system pressure applied to it. In the neutral position of the control lever
81
, the connection
94
is connected to the axial bores
193
via a small radial hole
221
in the rotary slide
181
, and is therefore relieved to the tank. Via the radial hole
222
which is open toward the annular groove
219
, the annular chamber
194
, that is to say the pressure inlet to the pressure reducing valve
68
, is connected to the annular groove
217
and therefore to the bypass line
66
.
Claims
- 1. A hydraulic pilot control system having two control outputs (96, 97) to which a control pressure is appliable and having a hydraulic pilot controller (69, 70), which has a handle (81) pivotable from a neutral position in a first direction to apply a variable control pressure to a first of the control outputs (96) and in a second direction to apply a variable control pressure to a second of the control outputs (97), and whereina pressure valve (69) of the pilot controller is displaced from the neutral position by deflection of the handle (81) to generate the variable control pressure at a control output (80) of the pressure valve (69), during a pivoting of the handle (81) in the first direction and during a pivoting of the handle (81) in the second direction, the pressure valve (69) of the pilot controller is adjusted by movement of the handle, and a directional control valve (70) of the pilot controller depends on a pivoting direction of the handle (81) from a rest position to change into a first switching position which connects the control output (80) of the pressure valve (69) to the first control output (96), or to change into a second switching position which connects the control output (80) of the pressure valve (69) to the second control output (97).
- 2. The hydraulic pilot control system as claimed in claim 1, wherein relationship between displacement of the displaceable pressure valve (69) when the handle (81) is pivoted in the second direction from the neutral position is the same as when the handle (81) is pivoted in the first direction from the neutral position.
- 3. The hydraulic pilot control system as claimed in claim 1, wherein the adjustable pressure valve (69) is a three-way pressure reducing valve.
- 4. A hydraulic pilot control system having two control outputs (96, 97) to which a control pressure is appliable and having a hydraulic pilot controller (69, 70), which has a handle (81) pivotable from a neutral position in a first direction to apply a variable control pressure to a first of the control outputs (96) and in a second direction to apply a variable control pressure to a second of the control outputs (97), anda pressure valve (69) which is displaced from the neutral position by the deflection of the handle (81) and generates the variable control pressure at a control output (80) of the pressure valve (69), wherein during a pivoting of the handle (81) in the first direction and during a pivoting of the handle (81) in the second direction, the pressure valve (69) is adjustable by movement of the handle, a directional control valve (70) which, depending on pivoting direction of the handle (81) from a rest position, which it assumes in the neutral position of the handle (81), is changable over into a first switching position, in which it connects the control output (80) of the pressure valve (69) to the first control output (96), or into a second switching position, in which it connects the control output (80) of the pressure valve (69) to the second control output (97); and wherein, in the rest position of the directional control valve (70), the two control outputs (96, 97) are relievable of pressure via a tank connection (91) of the directional control valve (70), circumventing the pressure valve (69).
- 5. A hydraulic pilot control system having two control outputs (96, 97) to which a control pressure is appliable and having a hydraulic pilot controller (69, 70), which has a handle (81) pivotable from a neutral position in a first direction to apply a variable control pressure to a first of the control outputs (96) and in a second direction to apply a variable control pressure to a second of the control outputs (97), anda pressure valve (69) which is displaced from the neutral position by the deflection of the handle (81) and generates the variable control pressure at a control output (80) of the pressure valve (69), wherein during a pivoting of the handle (81) in the first direction and during a pivoting of the handle (81) in the second direction, the pressure valve (69) is adjustable by movement of the handle, a directional control valve (70) which, depending on pivoting direction of the handle (81) from a rest position, which it assumes in the neutral position of the handle (81), is changable over into a first switching position, in which it connects the control output (80) of the pressure valve (69) to the first control output (96), or into a second switching position, in which it connects the control output (80) of the pressure valve (69) to the second control output (97); and wherein the directional control valve (70) has, as a movable control element, a rotary slide (181), whose axis is aligned with an axis of rotation of the handle (81) and which is rotatable via the handle (81) in a valve bore (180) in a valve housing (101).
- 6. The hydraulic pilot control system as claimed in claim 5, wherein the rotary slide (181) has an axial stop (102) with which it is urged by a spring (186) against a stop on the valve housing (101).
- 7. The hydraulic pilot control system as claimed in claim 6, wherein the handle (81) is fixed to a shaft (183) which is rotatably mounted relative to the valve housing, and has an axial stop (184) which acts in the direction out of the valve housing (101), wherein the rotary slide (181), as a separate part, is rotationally securely coupled to the shaft (183), and wherein between the shaft (183) and the rotary slide (181) there is arranged said spring (186) that urges the shaft and rotary slide axially apart.
- 8. The hydraulic pilot control system as claimed in claim 6, wherein connected in one piece to the rotary slide (181) is a cam disk (102), on which a pressure piece (145) belonging to a restoring device (103) for the handle (81) bears under force of a restoring spring (149), said cam disk (102) projecting radially beyond the rotary slide (181) and forming the axial stop of the rotary slide (181).
- 9. A hydraulic pilot control system having two control outputs (96, 97) to which a control pressure is appliable and having a hydraulic pilot controller (69, 70), which has a handle (81) pivotable from a neutral position in a first direction to apply a variable control pressure to a first of the control outputs (96) and in a second direction to apply a variable control pressure to a second of the control outputs (97), anda pressure valve (69) which is displaced from the neutral position by the deflection of the handle (81) and generates the variable control pressure at a control output (80) of the pressure valve (69), wherein during a pivoting of the handle (81) in the first direction and during a pivoting of the handle (81) in the second direction, the pressure valve (69) is adjustable by movement of the handle, a directional control valve (70) which, depending on pivoting direction of the handle (81) from a rest position, which it assumes in the neutral position of the handle (81), is changable over into a first switching position, in which it connects the control output (80) of the pressure valve (69) to the first control output (96), or into a second switching position, in which it connects the control output (80) of the pressure valve (69) to the second control output (97); and wherein a control element of the directional control valve (70), formed as a slide (181), in an axial bore (190) introduced into it from its one end, accommodates a permanently set pressure reducing valve (68) for an internal control pressure supply.
- 10. The hydraulic pilot control system as claimed in claim 9, wherein the pressure reducing valve (68) has an axial control connection (191) which is oriented into the axial bore (190) and is connected to a housing duct (79) via at least one radial hole (216) in the slide (181) opening into the axial bore (190), a radial outlet connection (192), which is connected to a chamber (188) in front of the end of the slide (181) via at least one axial bore (193) in the slide (181), and a radial feed connection (194), which is located further in than the outlet connection (192) in the axial bore (190) and which in turn is connected to a housing duct via at least one radial hole (221) in the slide (181) opening into the axial bore.
- 11. A hydraulic pilot control system having two control outputs (96, 97) to which a control pressure is appliable and having a hydraulic pilot controller (69, 70), which has a handle (81) pivotable from a neutral position in a first direction to apply a variable control pressure to a first of the control outputs (96) and in a second direction to apply a variable control pressure to a second of the control outputs (97), anda pressure valve (69) which is displaced from the neutral position by the deflection of the handle (81) and generates the variable control pressure at a control output (80) of the pressure valve (69), wherein during a pivoting of the handle (81) in the first direction and during a pivoting of the handle (81) in the second direction, the pressure valve (69) is adjustable by movement of the handle, a directional control valve (70) which, depending on pivoting direction of the handle (81) from a rest position, which it assumes in the neutral position of the handle (81), is changable over into a first switching position, in which it connects the control output (80) of the pressure valve (69) to the first control output (96), or into a second switching position, in which it connects the control output (80) of the pressure valve (69) to the second control output (97); and wherein the adjustable pressure valve (69) has a plunger (84) which is displaceable in direction of its axis, wherein the axis of the plunger (84) passes substantially perpendicularly through a pivot axis of the handle (81), and wherein the plunger (84) is displaceable, counter to force of a spring (133, 134) of the pressure valve (69), by a control cam (105) located on the circumference of a control disk (83) that is rotatable by the handle (81).
- 12. A hydraulic pilot control system having two control outputs (96, 97) to which a control pressure is appliable and having a hydraulic pilot controller (69, 70), which has a handle (81) pivotable from a neutral position in a first direction to apply a variable control pressure to a first of the control outputs (96) and in a second direction to apply a variable control pressure to a second of the control outputs (97), anda pressure valve (69) which is displaced from the neutral position by the deflection of the handle (81) and generates the variable control pressure at a control output (80) of the pressure valve (69), wherein during a pivoting of the handle (81) in the first direction and during a pivoting of the handle (81) in the second direction, the pressure valve (69) is adjustable by movement of the handle, a directional control valve (70) which, depending on pivoting direction of the handle (81) from a rest position, which it assumes in the neutral position of the handle (81), is changable over into a first switching position, in which it connects the control output (80) of the pressure valve (69) to the first control output (96), or into a second switching position, in which it connects the control output (80) of the pressure valve (69) to the second control output (97); and wherein the adjustable pressure valve (69), after its components are mounted in a housing (101), is adjustable from outside such that at a specific pivoting angle of the handle (81) a specific pilot control pressure is present on the control output (80) of the pressure valve (69).
- 13. The hydraulic pilot control system as claimed in claim 12, wherein the adjustable pressure valve has a valve housing, an axially guided plunger that is displaceable via the handle, a movable control element, which interacts with at least one control edge fixed to the housing, a control spring, which bears with one end on the movable control element and whose other end is drivable along in event of a displacement of the plunger, an adjustable stop which is fixed to the housing and, with respect to the control element, is located opposite the plunger, and an adjustment spring, which is arranged between the stop and the control element.
- 14. The hydraulic pilot control system as claimed in claim 12, wherein the adjustable pressure valve (69) has valve housing (101), an axially guided plunger (84) that is displaceable via the handle (81), a movable control element (125), which interacts with at least one control edge fixed to the housing, a control spring (134), which bears with one end on the movable control element (125) and whose other end is drivable along in event of a displacement of the plunger (84), and a control cartridge (108) introduced into the valve housing (101), on which the at least one control edge fixed to the housing is located and whose axial position is adjustable from outside.
- 15. The hydraulic pilot control system as claimed in claim 14, wherein the plunger (84) is guided in a guide sleeve (118) and wherein the control cartridge (108) is extended beyond the at least one control edge and accommodates
Priority Claims (1)
Number |
Date |
Country |
Kind |
199 13 276 |
Mar 1999 |
DE |
|
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
PCT/EP00/01790 |
|
WO |
00 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO00/57067 |
9/28/2000 |
WO |
A |
US Referenced Citations (6)
Foreign Referenced Citations (4)
Number |
Date |
Country |
1601720 |
Jan 1971 |
DE |
116080 |
Nov 1975 |
DE |
4316229 |
Nov 1994 |
DE |
19630798 |
Jan 1998 |
DE |