Information
-
Patent Grant
-
6247494
-
Patent Number
6,247,494
-
Date Filed
Thursday, March 2, 200024 years ago
-
Date Issued
Tuesday, June 19, 200123 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Webb Ziesenheim Logsdon Orkin & Hanson, P.C.
-
CPC
-
US Classifications
Field of Search
-
International Classifications
-
Abstract
A control valve device for a hydraulic user includes an electrically actuated control valve that has a sliding spool for the control of the connection of at least one user channel that is in communication with the user with a delivery channel and a reservoir channel. A shutoff valve located in the user channel blocks a return flow from the user to the control valve. A pilot control valve actuates the shutoff valve. When the user channel is connected with the reservoir channel, the pilot control valve can be actuated to move the shutoff valve into the open position by an actuator element. The control valve device has a low actuation force for the deflection of the sliding spool and for the actuation of the pilot control valve. A gear train actuates the sliding spool and the actuator element. The gear train has an input element which is effectively connected with an electrical drive device and the output element which is in a driving connection with the sliding spool and is effectively connected with the actuator element. In one configuration, the output element is in connection by a connecting rod with the sliding spool and located on the output element is a cam disc which is connected by a rocker arm with the actuator element.
Description
BACKGROUND INFORMATION
1. Field of the Invention
This invention relates to a control valve device for a hydraulic user. More specifically, the invention relates to an electrically actuated control valve that has a sliding spool to control the connection of at least one user channel with a delivery and a reservoir channel, a shutoff valve in the user channel, which shuts off a return flow from the user to the control valve and a pilot valve to actuate the shutoff valve.
2. Background Information
Control valve devices are often used to actuate single-action or double-action users. On each of the user channels that lead from the sliding spool to the user, these devices have a shutoff valve that can be controlled by a pilot control valve for the leak-free isolation of the user. The shutoff valves are check valves that open toward the user and are generally spring-loaded and can be moved by the pilot valve into the open position to make possible a return flow from the user to the sliding spool if, as a result of a corresponding deflection of the sliding spool, the user channel is in communication with the reservoir channel. In this case, the pilot valves are also spring-loaded check valves and can be actuated by an actuator element, e.g., an actuator pin, to move them into the open position. In the open position, a connection is created between the control pressure compartment of the shutoff valve, which is in communication with the user and the reservoir channel so that the shutoff valve is moved into the open position by the pressure of the user. This makes possible a flow of hydraulic fluid from the user via the open shutoff valve and the sliding spool to the reservoir.
DE-OS 20 32 107 describes a similar control valve device of the prior art with a mechanically actuated control valve that is a sliding spool. In this device, the pilot control valves can be actuated by actuator pins moved into the open position. The actuator pins are in communication with diagonal, conical-shaped control surfaces formed on the sliding spool. When there is an axial deflection of the sliding spool, the pilot control valve can thus be opened by the actuator pin. With a mechanical actuation of the pilot control valves by a diagonal control surface formed on the sliding spool, a transverse force is exerted on the actuator pin, which in turn produces friction. As a result, the control valve device of this type is sluggish and subject to wear caused by friction. Consequently, with a control valve device of this type, a high actuation force is required to move the sliding spool and to actuate the pilot control valve.
The object of this invention is to make available a control valve device of the type described above with an electrically actuated control valve, which has a low actuation force to move the sliding spool and to actuate the pilot control valve.
SUMMARY OF THE INVENTION
The invention actuates the sliding spool and the actuator element through a gear train, the input element of which is effectively connected with an electrical drive apparatus. The output element of the gear train is in a driving connection with the sliding spool, and is effectively connected with the actuator element of the pilot control valve.
The invention provides a single-stage gear train that includes the input element and the output element. The input element is connected with the electrical drive device. The output element is provided for the actuation of the sliding spool and of the actuator element of the pilot control valve. The actuation of the sliding spool and of the actuator element is accomplished by the output element of the gear train.
The control valve device of the invention has the following series of advantages.
With a gear train of the invention, it becomes possible to easily move the actuator element so that any transverse forces, and thus friction on the actuator element, are eliminated. The result is a low actuation force of the control valve device to move the sliding spool and the actuator element.
Furthermore, as a result of reduced friction, there is a higher resistance to wear. As a result of an appropriate design of the gear train, a speed reduction can be achieved. Consequently, a low drive force or a low drive torque on the drive device is sufficient to achieve the necessary actuation force. An electric motor may be used as the electrical drive device. As a result of the elimination of control surfaces on the sliding spool for the actuation of the actuator element, the construction of the sliding spool can be made simpler, more compact and more economical to manufacture.
In one embodiment of the invention, the output element is effectively connected with a cam disc to actuate the actuator element. With a cam disc, while the output element is rotating, the actuator element can be deflected with a low actuation force, and the pilot control valve can thus be moved into the open position.
The cam disc may be connected with a rocker arm which is effectively connected with the actuator element. When the output element is in rotation, the rocker arm is thus rotated and deflects the actuator element. It is thereby possible to reduce the opening stroke of the pilot control valve that results from the movement of the actuator element to the angle of rotation of the output element. This increases the precision of the resolution. In addition, with an actuation of the actuator of this type by a rocker arm, an actuation of the actuator pin that does not involve any transverse forces becomes possible. As a result, a low actuation force is necessary for the actuation of the pilot control valve.
A further reduction of the actuation force for the pilot control valve can be achieved if the rocker arm is provided with a roller that is arranged to rotate and is in contact against the cam disc. The connection between the cam disc and the rocker arm is therefore almost frictionless.
In one configuration, in which the actuator element is an actuator pin, there are advantages if the actuator pin is a sphere on the end opposite the pilot control valve, and is mounted in a conical-shaped recess of the rocker arm. It is thereby possible to deflect the actuator pin easily and without any transverse forces, whereby wear on the actuator pin caused by transverse forces is also eliminated.
The cam disc can thereby be non-rotationally connected with the output element. In order to keep the number of components low, the cam disc may be integrally connected with the output element. To actuate the sliding spool and to actuate the pilot control valve, all that is necessary is an output element which is in a driving connection with the sliding spool and is connected with the actuator element via the rocker arm.
In one embodiment of the invention, the output element is effectively connected with the sliding spool by a connecting rod. The output element, together with the connecting rod and the sliding spool, forms a crank mechanism. With a connecting rod, it is easily possible to convert a rotational movement of the output element into a linear movement of the sliding spool. A connecting rod of this type requires only small angular deviations from the longitudinal axis of the sliding spool to achieve the piston stroke of the longitudinal shutter. Only low transverse forces occur on the sliding spool, and thus a low actuation force is necessary for the deflection of the sliding spool.
In one refinement of the invention, the connecting rod is suspended in the sliding spool and/or in the output element. The installation of the connecting rod can thereby be performed simply by suspending the connecting rod in the sliding spool and/or the output element. Removing it is also simple. No additional fastening parts are required to connect the connecting rod with the output element and the sliding spool, which results in reduced manufacturing costs and easier assembly.
In one embodiment of the invention, to connect the connecting rod with the sliding spool and/or the output element, there is a sphere which can be fastened in a spherical-shaped recess. A sphere that can be housed in a spherical-shaped recess represents a simple design for the suspension of the connecting rod in the sliding spool or the output element.
This design can be achieved with little effort and manufacturing expense if the sphere is located on the connecting rod and the spherical-shaped recess is located on the output element and/or on the sliding spool. The sphere may be formed on the connecting rod and the spherical-shaped recess may be formed on the sliding spool. It is easily possible with little effort to manufacture a sphere on the connecting rod and a spherical-shaped recess on the sliding spool.
In an additional embodiment of the invention, to connect the connecting rod with the output element and/or the sliding spool, there is a boring in which a pin or bolt is rotationally fastened. This is likewise an easy and economical way to suspend the connecting rod in the sliding spool or in the output element without the need for additional fastening parts. The boring in the output element may be oriented parallel to the axis of rotation of the output element, and the connecting rod may be provided with the pin or bolt. A boring can easily be created in the output element. The connecting rod can also easily be provided with the pin or bolt, for example, by screwing or pressing. The bolt or pin can also be integral with the connecting rod. A connection of this type between the connecting rod and the output element is also extremely compact.
A fastening fork may be on the output element through a recess that is in communication with the boring. For this purpose, the connecting rod can be located in the fastening fork formed by the recess, and can thus be secured in the output element in the axial direction with respect to the boring.
In the outer area of a lateral bracket of the fastening fork, there may be an opening that runs through the lateral bracket. The presence of the opening in a lateral bracket of the output element makes it possible to move the connecting rod in the axial direction in the boring for installation or removal until the connecting rod is located in the fastening fork formed by the recess. As a result of the presence of the opening in the outer portion of the lateral bracket, the connecting rod can also be suspended in the output element and/or removed from the output element at angles of rotation of the output element that are beyond the range of angles of rotation that occur during operation of the control valve device. With an arrangement of this type, it therefore becomes possible that at angles of rotation of the output element that occur during operation, the connecting rod can be secured between the lateral brackets of the fastening fork against accidentally becoming unhinged in the recess of the output element.
The gear train may be a worm gear pair. In one embodiment of the invention, the gear train is a spur gear. A spur gear is easy to manufacture, which results in low manufacturing costs. The spur gear can be made particularly compact if the output element is a toothed quadrant that is engaged with an input element in the form of a gear wheel. As a result of the crank mechanism that includes the output element, the connecting rod and the sliding spool, all that is necessary to generate the piston stroke is a limited angle of rotation of the output element of the spur gear of the sliding spool. As a result, the output element can be a toothed quadrant of a gear wheel.
The input element can be non-rotationally connected with an output shaft of the drive device. The input element may be integral with the output shaft of the drive device. The input element, which can be a gear wheel, for example, can thereby be formed on the output shaft of the drive device.
The cost of manufacture of the control valve device of the invention can be reduced if the gear train is located in a transmission housing to which the drive device can be fastened. The transmission housing can thereby be fastened to a control valve block of the control valve device. The input element and the output element as well as the drive device are thus located in or on a separate transmission housing which is connected with the control valve block. Thus no additional devices are necessary in the control valve block for the mounting of the input or output element or for the fastening of the drive device. As a result, the control valve block is economical to manufacture.
The cost of manufacturing can be further reduced if the rocker arm and the pilot control valve are located in the transmission housing, and the actuator pin is mounted in the transmission housing so that it can move longitudinally. The actuator devices for the sliding spool and the shutoff valve are thereby located in the transmission housing, which is connected with the sliding spool only by the connecting rod. This results in easy installation and removal of the actuator device on the valve block because all that is necessary is to suspend or remove the connecting rod in the sliding spool or the output element. As a result of the integration of the pilot control valve into the transmission housing, less effort is also required to manufacture a control valve block in a multi-layer construction. The multi-layer construction includes a plurality of segment plates that are connected to one another by soldering or by some other adhesive. Complex, time-consuming and expensive borings at a right angle to the layers can be eliminated, as a result of which the cost of manufacturing a multi-layer control valve block can be reduced.
With regard to a low cost of manufacture for the transmission housing, the transmission housing may have an opening in an area that faces the control valve block, and the output shaft of the drive device may be rotationally mounted in a housing boring of the transmission housing. The diameter of the input element that is effectively connected with the output shaft is less than or equal to the diameter of the housing boring. The output element and the rocker arm can thereby be installed through the opening in the transmission housing. When the transmission housing is attached to the control valve block, the connecting rod that is effectively connected with the sliding spool can also be guided through the opening. The diameter of the input element is less than or equal to the diameter of the output shaft. The output shaft of the drive device and the input element that is effectively connected with the drive device can thereby be inserted through the housing boring into the transmission housing. An additional housing cover on the transmission housing is not necessary for the installation of the input element.
In the vicinity of the housing boring, there may be a sealing device to seal the output shaft with respect to the transmission housing. It thereby becomes possible in a simple manner to seal the drive device with respect to the transmission housing.
In one refinement of the invention, the sliding spool is effectively connected with a spring retraction device. A spring retraction device, which moves the sliding spool to the center position when it is not actuated, also eliminates the gear play between the input element and the output element when the sliding spool is not in the center position, i.e., when the control valve device is actuated.
The electrical drive device may be a drive motor, in particular a stepper motor. In the control valve device of the invention, the speed reduction necessary for the actuation of the sliding spool is achieved by the gear train when a stepper motor is used, combined with the actuation of the pilot control valve without transverse force and thus without wear to the actuator pin, whereby the rocker arm also reduces the opening stroke of the pilot control valve to the piston stroke of the sliding spool and thus achieves an improved resolution.
BRIEF DESCRIPTION OF THE DRAWINGS
Additional advantages and details of the invention are explained in greater detail below with reference to the exemplary embodiments that are illustrated schematically in the accompanying figures, in which:
FIG. 1
is a schematic diagram of a control valve device according to the invention;
FIG. 2
is a longitudinal sectional view through a control valve device as illustrated in
FIG. 1
;
FIG. 3
is an additional longitudinal sectional view through the control valve device as illustrated in
FIG. 1
;
FIG. 4
is a sectional view taken along Line A—A in
FIG. 2
;
FIG. 5
is a sectional view taken along Line B—B in
FIG. 2
;
FIG. 6
is a sectional view taken along Line C—C in
FIG. 4
;
FIG. 7
is a sectional view taken along Line D—D in
FIG. 4
; and
FIG. 8
is a sectional view taken along Line E—E in FIG.
4
.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1
is a schematic diagram of a hydrostatic drive system with a first exemplary embodiment of a control valve device
1
of the invention for the control of a single-action user
2
, for example a single-action hydraulic cylinder, and a second exemplary embodiment of a control valve device
3
of the invention for the control of a double-action user
4
, for example a double-action hydraulic cylinder. The user
2
may be, for example, a lifting cylinder and the user
4
may be a tilting cylinder of an industrial truck. The control valve devices
1
,
3
are located in a common control valve block
5
.
The control valve device
1
has a control valve
6
which is connected on the input side to a delivery branch channel
7
, which is in communication with a delivery
10
channel
9
connected to a pump
8
. A reservoir branch channel
10
leads from the control valve
6
to a reservoir channel
11
, which leads to a reservoir
12
. The connection between the delivery branch channel
7
or the reservoir branch channel
10
and a user channel
13
, which is connected
15
with the user
2
, can be controlled with the control valve
6
.
The control valve device
3
has a control valve
14
which is connected by a delivery branch channel
15
to the delivery channel
9
and by a reservoir branch channel
16
to the reservoir channel
11
. Two user channels
17
,
18
lead to the user
4
, and the connection between these user channels
17
,
18
and the delivery branch channel
15
or the reservoir branch channel
16
can be controlled by the control valve
14
.
The control valves
6
and
14
are sliding spool valves with a spring-centered center position that provide throttling in intermediate positions. In the center position of control valves
6
and
14
, the corresponding connections are closed.
For the leak-free isolation of the user
2
, a shutoff valve
20
, in the form of a check valve that opens toward the user
2
, is located in the user channel
13
. When the control valve
6
is actuated into the switched position illustrated in the top of
FIG. 1
to lower a load applied to the user
2
, the shutoff valve
20
can be moved toward an open position by a pilot control valve
21
that is also in the form of a check valve. The control pressure chamber of the shutoff valve
20
that acts in the closing direction is thereby connected by a control pressure line
22
to the control pressure chamber of the pilot control valve
21
that acts in the closing direction, and is in communication by a control pressure line
23
with the reservoir channel
11
.
For the leak-free isolation of the user
4
, shutoff valves
25
,
26
that open toward the user
4
are located in the user channels
17
,
18
, respectively. Each of the shutoff valves
25
,
26
can be actuated by a pilot control valve
27
,
28
that is in the form of a check valve. For this purpose, a control pressure line
29
runs from the control pressure chamber of the shutoff valve
25
that acts in the closing direction to the pilot control valve
27
. The pilot control valve
27
, through a control pressure line
30
, makes possible a connection between the control pressure line
30
and the reservoir channel
11
in the opened position. The control pressure chamber of the shutoff valve
26
that acts in the closing direction is connected by a control pressure line
31
to the pilot control valve
28
, which in the open position makes possible a connection between the control pressure line
31
, via the control pressure line
30
, and the reservoir channel
11
. The pilot control valve
27
can thereby be actuated in the event of an actuation of the control valve
14
toward the bottom switched position illustrated in the figure and the pilot control valve
28
can be moved, in the event of an actuation of the control valve
14
toward the top switched position in the figure. The shutoff valves
25
and
26
, which in the corresponding switched position of the control valve
14
are located in the user channels
17
,
18
which is in communication with the reservoir branch channel
15
and thus in the return line of the user
4
, are actuated into the open position, as a result of which hydraulic fluid can flow from the user channel
17
or
18
to the reservoir
12
.
To determine the speed of movement of the user
2
, there is a sensor device
35
that is a delivery flow sensor, which is connected with an electronic control device
40
. The measurement element of the sensor device
35
can thereby be the valve body of the shutoff valve
20
. The sensor device
35
can also be formed so that the corresponding speed of movement of the user
2
can be measured both during the ascent and the descent of the user
2
.
The speed of movement of the user
4
can be measured by a sensor device
36
, which is effectively connected with the electronic control device
40
. The sensor device
36
can be a delivery flow sensor, for example, which is located in the reservoir branch line
16
that is in communication with the reservoir
12
.
The control valve
6
can be actuated electrically, whereby there is an electrical drive device
41
, such as a stepper motor, for example, which is connected to the electronic control device
40
. The direction of movement and a setpoint speed are specified by a setpoint device
42
, such as a joystick, for example, which is effectively connected with the electronic control device
40
. The control valve
14
can also be actuated electrically, for example by a drive device
43
that is a stepper motor, and is effectively connected with an electronic control device
40
. To specify a direction of movement and a setpoint speed of the user
4
, there is a setpoint device
44
, such as a joystick, for example, which is connected with the electronic control device
40
.
To control the unpressurized circulation of the delivery flow of the pump
8
, which is a constant delivery pump, when the control valves
6
,
14
are not actuated, and to limit the maximum working pressure of the users
2
,
4
, there is a pilot-controlled pressure relief valve
46
which is connected on the input side to the delivery channel
9
and on the output side to the reservoir channel
11
. The response pressure of the pressure relief valve
46
is thereby set by an electrically actuated pilot control valve
47
which is connected to the electronic control device
40
.
FIGS. 2 and 3
each show a longitudinal section through the control valve block
5
which has a construction that consists of a plurality of segment plates that are connected together by soldering or some other adhesive process. The delivery channel
9
and the reservoir channel
1
are formed by communicating recesses in some of the segment plates.
The sliding spool
51
or the control valve
6
is located so that it can move longitudinally in a housing boring
50
that is formed in the control valve block
5
. The housing boring
50
is thereby provided with an annular groove
52
that starts from an annular groove that is connected with the delivery channel S. The annular groove
52
is connected to the user channel
13
. The annular groove
52
is in communication with an annular groove
53
of a housing boring
54
in which the shutoff valve
20
is located, which simultaneously forms the sensor device. An additional annular groove
55
that is on the housing boring
51
is in communication with the reservoir channel
11
.
In a housing boring
60
of the control valve block
5
, the sliding spool
61
of the control valve
14
is located so that it can move longitudinally, whereby the housing boring
60
, starting from an annular groove that is in communication with the delivery channel
9
, is provided with a plurality of annular grooves
62
,
63
,
64
and
65
. The annular groove
62
is in communication with an annular groove
66
on a housing boring
67
, in which the shutoff valve
25
is located. The housing boring
67
is in turn in communication with an annular groove
68
which is in communication with the user channel
17
in a manner not illustrated in any further detail. In an analogous manner, the annular groove
63
is in communication with an annular groove
69
of a housing boring
70
, in which the shutoff valve
26
is located. An annular groove
71
on the housing boring
70
is thereby in communication with the user channel
18
in a manner not illustrated in any further detail. The annular groove
64
and the annular groove
65
of the housing boring
60
lead to an annular groove
72
on a housing boring
73
, in which the sensor device
36
is located. An annular groove
74
located on the housing boring
73
is thereby in communication with the reservoir channel
11
.
The shutoff valve
20
has a control pressure chamber
80
that acts in the closing direction. A spring
81
is located in control pressure chamber
80
which is in communication via a throttle device
82
with the segment of the user channel
13
that is connected to the user
2
. In an analogous manner, the shutoff valves
25
and
26
each have a control pressure chamber
84
or
85
which acts in the closing direction, in which there are respective springs
86
and
87
, and which are in communication via respective throttle devices
88
and
89
with the annular grooves
68
and
71
. Control pressure chambers
84
and
85
are in communication with the corresponding segment of the user channels
17
and
18
which are in communication with the user
4
.
The control pressure chamber
80
of the shutoff valve
20
is in communication, in a manner not shown in any greater detail, with the control pressure line
22
which leads to the pilot control valve
21
. The control pressure chambers
84
and
85
of the shutoff valves
25
and
26
, respectively, are connected to the control pressure lines
29
and
31
, respectively, which are not shown in any greater detail and which lead to the respective pilot control valves
27
and
28
. The shutoff valves
20
,
25
and
26
thereby have a differential piston surface.
As shown in
FIGS. 2 and 7
, the pilot control valve
21
is a spring-loaded check valve in the isolation position with a valve element
90
that is in the form of a sphere. The valve element can be moved toward an opening position by an actuator element
91
that is in the form of an actuator pin. The pilot control valve
21
is thereby located in a step-shaped boring
92
of a transmission housing
93
which is closed by a screw plug
94
. The pilot control valve
21
consists of a component
95
in connection with a flange on a shoulder of the boring
92
, and a valve seat component
96
in contact with the component
95
and provided with a longitudinal opening
97
which, on the end opposite the component
95
, forms a valve seat for the valve element
90
. The actuator pin
91
is mounted so that it can move longitudinally in a boring of the component
95
. In the component
95
, there is an annular groove
98
in communication via opening
99
with the longitudinal opening
97
of the component
96
. The annular groove
98
is thereby in communication with the control pressure line
23
, which can lead to the reservoir channel, for example. A control pressure chamber
100
in the boring
92
, and which is active in the closing direction of the valve element
90
, is in communication with the control pressure line
22
.
FIG.
2
and
FIG. 8
show the construction of the pilot control valves
27
,
28
, which are spring-loaded check valves with valve elements
101
,
102
in the form of a sphere. The valve seat of the valve element
101
,
102
is realized in respective valve seat component
103
,
104
, located in a step-shaped boring
105
,
106
of the transmission housing
93
. The boring
105
,
106
can be closed by a respective screw plug
117
or
118
. In the borings
105
,
106
there are respective control pressure chambers
107
and
108
which are active in the direction of the closing position. The control pressure chamber
107
is connected to the control pressure line
29
and the control pressure chamber
108
is connected to the control pressure line
31
. The valve seat components
103
and
104
are each provided with respective longitudinal openings
109
and
110
. Actuator elements
111
and
112
that are in the form of actuator pins that can move respectively in the borings
105
and
106
are each provided with a longitudinal groove. When the valve elements
101
,
102
are open, hydraulic fluid can flow out of the control pressure lines
29
,
31
via the longitudinal grooves
113
,
114
into the interior of the housing
115
. As shown in
FIG. 2
, housing
115
is in communication with the annular groove
65
which can be brought into communication with the reservoir channel
11
. The boring
105
,
106
is thereby widened in the vicinity of the actuator element
111
,
112
, so that the actuator pin
111
,
112
is mounted in the boring
105
,
106
only in the area facing the valve seat element
101
,
102
.
To actuate the sliding spool
61
or
62
and the pilot control valve
21
or
27
,
28
associated with the sliding spools, there is a gear train
120
or
121
that is in the form of a spur gear.
FIG. 5
shows a longitudinal section of gear train
121
by way of example for the gear trains
120
,
121
.
The input element
122
of the gear train
120
and
121
is non-rotationally connected with the output shaft
123
of the corresponding electrical drive device
41
or
43
, which can be a stepper motor, for example. The drive device
41
or
43
is thereby detachably fastened to the transmission housing
93
by screws. The output shaft
123
of the drive device
41
or
43
is rotationally mounted in a housing boring
124
of the transmission housing
93
. In the vicinity of the housing boring
124
there is also a sealing device
195
. The transmissions
120
or
121
have respective output elements
125
and
126
which are mounted so that they can rotate around an axis of rotation D that is oriented parallel to the output shaft
123
and perpendicular to the longitudinal axis L of the sliding spools
51
and
61
, respectively. For purposes of mounting, the output elements
125
and
126
are provided with a boring
127
, which is penetrated by a bearing pin
128
that is located in the transmission housing
93
. The bearing pin
128
is axially secured in the transmission housing
93
by a securing device
175
and is sealed by a sealing device
129
.
The input element
122
of the transmission
120
and
121
, respectively, is a gear wheel which is non-rotationally connected with the output shaft
123
. The gear wheel is engaged with a gear wheel that is in the form of a toothed quadrant
131
,
132
. The toothed quadrants
131
and
132
are formed integrally, i.e. in one piece, on the respective output elements
125
and
126
. The outside diameter of the input element
122
is thereby less than or equal to the diameter of the housing boring
124
, whereby the output shaft
123
can be inserted together with the input element
122
into the transmission housing
93
. A cam disc
133
or
134
is also formed on or non-rotationally fastened to the respective output element
125
or
126
. The cam disc
133
, as shown in
FIG. 7
, also has an effective cam
135
which is effectively connected with a roller
137
that is rotationally located on a rocker arm
136
. The cam
135
is effectively connected with a roller
137
that is rotationally connected to a rocker arm
136
. In the illustrated center position of the control valve device
6
, the roller
137
is thereby in contact with the cam
135
. The cam disc
134
, as shown in
FIG. 8
, has two effective cams
138
,
139
. The cam
138
is in contact with a roller
141
that is located on a rocker arm
140
and the cam
139
is in contact with a roller
143
that is located on a rocker arm
142
, in the illustrated center position of the control valve
14
.
The respective rocker arms
136
or
140
,
142
are each rotationally mounted around a pivoting axis S in the transmission housing
93
, which pivoting axis S is oriented parallel to the axis of rotation D of the respective output elements
125
and
126
. The pivoting axis S is coaxial to the output shaft
123
. For the rotational fastening of the rocker arm
136
or of the rocker arm
140
,
142
, the rocker arms are each provided with a boring
150
to hold a bearing pin
151
which is fastened in a boring
105
of the transmission housing
93
and secures the rocker arm or rocker arms in the axial direction by a collar
153
.
The rocker arm
136
which is in effective contact with the cam
135
of the cam disc
133
that is formed on the output element
125
is connected with the actuator pin
91
of the pilot control valve
21
. The actuator pin
91
is thereby in contact with the external surface of the rocker arm
136
. The rocker arm
140
which is in effective contact with the cam
138
of the cam disc
134
that is formed on the output element
126
controls the pilot control valve
27
by the actuator pin
111
. The rocker arm
142
that is in effective contact with the cam
139
of the cam disc
134
controls the pilot control valve
28
by the actuator pin
112
. The actuator elements
111
,
112
are thereby in a spherical shape in the portion that projects out of the borings
105
,
106
of the transmission housing
93
, and are located in conical-shaped recesses
145
,
146
of the corresponding rocker arms
140
,
142
.
To actuate the sliding spool
51
, there is a connecting rod
150
which is connected with the output element
125
of the transmission
120
and the sliding spool
51
. The sliding spool
61
is actuated by a connecting rod
151
which is connected with the output element
126
of the transmission
121
and the sliding spool
61
.
The connecting rod
150
or
151
is suspended for easy installation in the respective output element
125
or
126
and in the respective sliding spool
51
or
61
. For this purpose, the end of the connecting rod
150
or
151
facing the sliding spool
51
or
61
is provided with a sphere
152
or
154
, which is held by suspension in a spherical-shaped recess
153
,
155
on the end surface of the sliding spool
51
or
61
.
To fasten the connecting rod
150
,
151
in the output element
125
,
126
, as shown in
FIGS. 2
,
4
and
6
to
8
, in each output element
125
,
126
, a recess
160
,
161
is in a center plane of the output element. The recesses
160
,
161
, as shown in
FIG. 4
, form, in the respective output elements
125
,
126
, fastening forks
158
,
159
, each of which has two lateral brackets
125
a
,
125
b
, and
126
a
,
126
b
. In the vicinity of the recess
160
,
161
and thus of the fastening fork
158
,
159
, the output element
125
,
126
is provided with a transverse boring
162
,
163
, which is oriented parallel to the axis of rotation D of the output element
125
,
126
. The connecting rod
150
,
151
is provided on the end opposite the sphere
152
,
153
with a pin
156
,
157
which is oriented perpendicular to the shaft of the connecting rod
150
,
151
. The pin
156
,
157
can, for example, be pressed or screwed to the connecting rod
150
,
151
.
The connecting rod
150
,
151
is located in the recess
160
,
161
and is secured in the axial direction between the side pieces
125
a
,
125
b
and
126
a
,
126
b
of the respective fastening fork
158
,
159
. A lateral bracket
125
a
,
126
a
of the respective fastening fork
158
,
159
is penetrated by an opening
170
,
171
, located in the vicinity of a boundary surface of the recess
160
,
161
and thus in the outer portion of the fastening fork
158
,
159
, and which extends from the transverse boring
162
,
163
to the outer periphery of the output element
125
,
126
. If the connecting rod
150
,
151
is pivoted far enough that it is aligned with the opening
170
,
171
, the connecting rod
150
,
151
can be pushed in the axial direction out of or into the transverse boring
162
,
163
and thus the recess
60
,
161
. The opening
170
,
171
is thereby located so that the pivoting angle of the output element
125
,
126
for the installation or removal of the connecting rod
150
,
151
in the output element
125
,
126
lies outside the angle of rotation that occurs during operation of the control valve
6
,
14
.
The sliding spool
51
or
61
, as shown in
FIG. 2
, is effectively connected on the end opposite the connecting rod
150
or
151
with a spring retraction device
180
or
181
that acts in both directions. The spring retraction device
180
or
181
retracts the sliding spool
51
or
61
into the illustrated center position and eliminates gear play between the input element
122
and the output element
125
or
126
of the respective gear train
120
,
121
outside the center position.
As shown in
FIGS. 4
,
7
and
8
, the housing
93
, in an area facing the control valve block
5
, has an opening
190
or
191
, through which the rocker arm
136
or
140
,
142
and the output element
125
or
126
can be installed. In addition, when the transmission housing
93
is attached to the control valve block
5
, the connecting rod
150
or
151
to the sliding spool
51
or
61
is guided through the opening
190
or
191
.
The function of the control valve device is explained in greater detail by way of example below, with reference to the gear trains illustrated in
FIGS. 7 and 8
, in connection with FIGS.
2
and
3
:
When the output element
125
of the gear train
120
is actuated by a determined angle of rotation in the direction
190
by a corresponding actuation of the input element of the gear train
120
, as the result of an actuation of the drive device
41
by a larger angle of rotation in the opposite direction, the rocker arm
136
is deflected upward in
FIG. 7
from the cam
135
formed on the cam track
133
, as a result of which the rocker arm
136
is pivoted around the axis of rotation S upward in
FIG. 7
, and the valve element
90
of the pilot control valve
21
is pushed by the force of the actuator element
91
against the force of the spring into the opening position. As a result, hydraulic fluid flows from the control pressure line
22
via the control pressure chamber
100
, the longitudinal opening
97
, the opening
99
and the annular groove
98
into the control pressure line
23
, which is connected with the reservoir channel
11
. The control pressure chamber
80
of the shutoff valve
20
is thereby depressurized and the shutoff valve
20
is pushed into the opening position by the pressure in the user channel
13
. At the same time, the connecting rod
150
is deflected downward in
FIG. 7
, so that the sliding spool
51
is deflected downward in
FIG. 2
, in which a connection is created between the annular groove
52
and the annular groove
55
, which is in communication with the reservoir channel
11
, as a result of which hydraulic fluid can flow from the user
2
via the opened shutoff valve
20
and the sliding spool
51
to the reservoir
12
.
When the output element
126
of the gear train
121
is pivoted in the direction
190
by a corresponding deflection of the input element
112
by the drive device
43
, the rocker arm
140
is deflected upward in the
FIG. 8
by the cam
138
located on the cam disc
134
around the axis of rotation S, and thus the valve seat element
101
of the pilot control valve
27
is pushed into the open position by the actuator pin
111
. The control pressure line
29
is thereby connected via the control pressure chamber
107
, the longitudinal opening
109
and the longitudinal groove
113
of the actuator element
111
with the interior
115
of the housing, which is in communication with the annular groove
65
. The control pressure chamber
84
of the shutoff valve
25
is thereby depressurized and the shutoff valve
25
is pushed into the opening position by the user pressure. The connecting rod
151
thereby deflects the sliding spool
61
downward in
FIG. 2
into a position in which the annular groove
62
is in communication with the annular groove
65
and the annular groove
63
is in communication with the delivery channel
9
, and thus the user channel
18
forms the admission line and the user channel
17
the return line of the user
4
, whereby hydraulic fluid can flow out of the user via the opened shutoff valve
25
.
When there is a deflection of the output element
126
in a direction opposite to the direction
190
, the rocker arm
142
is correspondingly pivoted by the cam
139
and the pilot valve
28
is moved into the open position, as a result of which the shutoff valve
26
is actuated. In this switched position of the sliding spool
61
, in which the annular groove
63
is in communication with the annular groove
64
and thus with the reservoir channel
11
, and the annular groove
62
is in communication with the delivery channel
9
and thus with the user channel
17
, represents the admission line and the user channel
18
the return line of the user
4
, is located in the return line of the user
4
and thus makes possible a flow of hydraulic fluid from the user
4
to the reservoir
12
.
With the gear train
120
,
121
provided in the control valve device
6
,
14
of the invention, there is a necessary reduction of the angle of rotation of the drive device when a stepper motor is used for the actuation of the sliding spool
51
,
61
. An actuation of the pilot control valves
21
,
27
,
28
by rotationally mounted rocker arms
136
,
140
,
142
which deflect the actuator elements
91
,
111
,
112
, results in no transverse forces occurring on the actuator elements
91
,
111
,
112
which could lead to wear and increased actuation forces. In addition, as a result of the presence of the rocker arms
136
,
140
,
142
, the opening stroke of the pilot control valves
21
,
27
,
28
is reduced to the piston stroke of the sliding spool
51
,
61
. As a result, it is ensured that the pilot control valves
21
,
27
,
28
can be moved into the open position even with a short piston stroke of the sliding spool
51
,
61
. As a result of the gear train
120
,
121
and the rocker arm
136
,
140
,
142
, a low drive movement of the drive device
41
,
43
is necessary to achieve the actuation force of the sliding spool
51
,
61
and of the actuator elements
91
,
111
,
112
.
The above-described invention is intended to be illustrative of the present invention and not restrictive thereof. It will be apparent that various changes may be made to the present invention with the spirit and scope of the present invention. The present invention is intended to be defined by the appended claims and equivalents thereto.
Claims
- 1. A control valve device for a hydraulic user comprising:a plurality of hydraulic channels including at least one user channel in communication with the user, a delivery channel and a reservoir channel; a sliding spool for the control of the connection of at least one user channel with a delivery channel and a reservoir channel; a shutoff valve located in the user channel which blocks a return flow from the user to the control valve; a pilot control valve for the actuation of the shutoff valve, wherein when the user channel is connected with the reservoir channel, the pilot control valve can be actuated to move the shutoff valve into the open position; an actuator element to actuate the pilot valve; a gear train to actuate the sliding spool and the actuator element, the gear train housing an input element and an output element in a driving connection with the sliding spool and effectively connected with the actuator element; and an electrical drive device effectively connected with the input device.
- 2. The control valve device as claimed in claim 1 wherein the output element is effectively connected with a cam disc to actuate the actuator element.
- 3. The control valve device as claimed in claim 2 wherein the cam disc is connected with a rocker arm which is effectively connected with the actuator element.
- 4. The control valve device as claimed in claim 3 wherein the rocker arm is provided with a rotating roller which is in contact with the cam disc.
- 5. The control valve device as claimed in claim 3 wherein the actuator element is an actuator pin on an end opposite the pilot control valve in the shape of a sphere and located in a conical-shaped recess of the rocker arm.
- 6. The control valve device as claimed in claim 2 wherein the cam disc is formed in one piece with the output element.
- 7. The control valve device as claimed in claim 1 wherein the output element is connected with the sliding spool by a connecting rod.
- 8. The control valve device as claimed in claim 7 wherein t he connecting rod is suspended in the sliding spool or in the output element.
- 9. The control valve device as claimed in claim 7 wherein there is a sphere which can be fastened in a spherical recess to connect the connecting rod.
- 10. The control valve device as claimed in claim 9 wherein the sphere is located on the connecting rod and the spherical recess is located on the output element.
- 11. The control valve device as claimed in claim 9 wherein the sphere is formed on the connecting rod and the spherical recess is formed on the sliding spool.
- 12. The control valve device as claimed in claim 7 wherein a boring in which a pin can be rotationally fastened provides the connection of the connecting rod.
- 13. The control valve device as claimed in claim 12 wherein the boring is located on the output element parallel to the axis of rotation of the output element and the connecting rod is provided with the pin.
- 14. The control valve device as claimed in claim 13 wherein a fastening fork is on the output element including a recess that is in communication with the boring.
- 15. The control valve device as claimed in claim 14 wherein in the outer area of a lateral bracket of the fastening fork, there is an opening that extends through the lateral bracket.
- 16. The control valve device as claimed in claim 1 wherein the gear train includes a spur gear.
- 17. The control valve device as claimed in claim 16 wherein the output element is a toothed quadrant, which is engaged with an input element that is a gear wheel.
- 18. The control valve device as claimed in claim 1 wherein the input element is integral with an output shaft of the drive device.
- 19. The control valve device as claimed in claim 1 wherein the gear train is located in a transmission housing to which the drive device can be fastened and wherein the transmission housing can be fastened to a control valve block of the control valve device.
- 20. The control valve device as claimed in claim 19 further including a rocker arm that can rotate in the transmission housing.
- 21. The control valve device as claimed in claim 19 wherein the pilot control valve is located in the transmission housing.
- 22. The control valve device as claimed in claim 19 further including an actuator pin mounted so that it can move longitudinally in the transmission housing.
- 23. The control valve device as claimed in claim 19 wherein the transmission housing has an opening in an area that faces the control valve block, and an output shaft of the drive device is rotationally mounted in a housing boring of the transmission housing, wherein the diameter of the input element that is effectively connected with the output shaft is less than or equal to the diameter of the housing boring.
- 24. The control valve device as claimed in claim 23 wherein in the vicinity of the housing boring, there is a sealing device to seal the output shaft with respect to the transmission housing.
- 25. The control valve device as claimed in claim 1 wherein the sliding spool is effectively connected with a spring retraction device.
- 26. The control valve device as claimed in claim 1, wherein the electrical drive device is a stepper motor.
Priority Claims (1)
Number |
Date |
Country |
Kind |
199 09 712 |
Mar 1999 |
DE |
|
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
5738142 |
Eike et al. |
Apr 1998 |
|