Regulating valve

A regulating valve comprising a housing having a cylindrical valve chamber, the valve chamber being provided with at least one inlet and at least two outlets, the inlet and the outlets being at least partially closeable as needed by a common valve body arranged in the valve chamber and rotatable around an axis, the valve body being operable by an actuator, the inlet and/or at least one of the outlets being surrounded by a sealing device on the side of the housing facing the valve body and the sealing device being able to be brought into sealing engagement with the valve body under elastic preload. The valve body is designed having the shape of the segment of a cylinder and is bounded on the peripheral side by two boundary surfaces which each have an edge on the side facing the housing, the edge overtravelling the inlet during its opening being designed as an efflux edge and having an elliptically shaped recess extending in axial direction. Configured in the valve body is a duct-shaped opening which extends between the boundary surfaces and penetrates them.

BACKGROUND OF THE INVENTION 
The invention relates to a regulating valve of the type comprising a 
housing with a cylindrical valve chamber that has at least one inlet and 
at least two outlets. The inlet and the outlets of this type of valve can 
be at least partially closed as needed by a common valve body arranged in 
the valve chamber and rotatable around an axis. The valve body is designed 
as a rotary valve and is operable by an actuator. The inlet and/or at 
least one of the outlets is surrounded by a seal which can be brought into 
sealing engagement with the valve body under elastic preload. 
Such a regulating valve is known from German Patent Application 26 32 476. 
The regulating valve in that patent application is designed as a valve for 
controlling flow and is used in a mixing faucet for mixing cold and hot 
water. Both the inlets and the outlets are arranged diametrically opposite 
one another, respectively, the inlets and the outlets being arranged at 
right angles to one other. 
In that device, the actuating forces required to move the valve body to 
open the inlets, through the strong acceleration of the flow at the efflux 
edge of the valve body, are considerable, since the suction effects 
arising upon opening act upon the valve body in a manner that cause it to 
want to close. To overcome the suction forces, the actuator for that 
device should be designed to be correspondingly strong, which is a 
disadvantage economically and with regard to the compact dimensions of the 
valve. 
SUMMARY OF THE INVENTION 
An object of the invention is to develop further a regulating valve in such 
a way that the starting torque necessary to open the regulating valve is 
substantially reduced, that a more consistent opening characteristic of 
the valve is obtained, and that the actuator can be designed to be more 
economical and compact. 
Within the framework of the present invention, the valve body may be 
designed having the shape of a segment of a cylinder. The peripheral sides 
of the segment constitute two boundary surfaces, each of which has an edge 
on the side facing the housing (i.e., on the side of the boundary surface 
farthest from the axis of rotation of the valve body). The edge 
overtravelling the inlet during its opening is designed as an efflux edge 
and has an elliptically shaped recess extending in the axial direction. A 
duct-shaped opening is configured in the valve body and extends from one 
boundary surface to the other. 
With such a configuration, upon opening the inlet, a sudden strong 
acceleration of the flow is avoided at the efflux edge of the valve body, 
and, because of this, suction forces which act upon the valve body in a 
manner that cause it to want to close are kept low. The static pressure 
which acts on the valve body remains nearly constant during the opening of 
the inlet, so that more uniform opening characteristics are achieved, 
beginning with the opening of the inlet up to the clearing of the entire 
opening cross-section. 
The elliptical shape of the recess is particularly advantageous in that at 
first only a very small passage cross-section is released past the valve 
body and, because of this, the actuating force during the opening process 
up until the entire cross-section of the inlet is released remains 
constant to a large extent. These advantageous operating characteristics 
are advanced by the configuration of the duct-shaped opening within the 
valve body. The starting torque necessary to open the regulating valve is 
further reduced by the duct-shaped opening. It turns out that the 
adjusting torque needed to adjust the valve body reaches a maximum when 
the inlet is about half open. The duct-shaped opening causes the flow 
through the valve with reference to the axis of the valve body, which 
forms the rotational center point, to be substantially symmetrical. 
Therefore, the resulting torque on the valve body is markedly reduced. 
Because of this, the regulating valve is particularly suited for 
applications of high volumetric flow accompanied by low actuating forces 
of the valve body. 
The elliptical recess can be configured such that it is extends adjacent 
to, but spaced from, the top and bottom sides which comprise the axial 
boundaries of the valve body. In this manner an excellent guidance of the 
valve body in the housing, in particular near the efflux edge which is 
provided with the elliptical recess, is assured. Appearances of canting of 
the valve body in the housing are reliably avoided by this configuration. 
The valve body can be actuated by an electrically operated stepping motor, 
the stepping motor preferably being linked in a signal-conductive manner 
with an electronic regulating device. Depending upon preselected 
parameters which are stored, for instance, in the form of a characteristic 
in the regulating device, the passage cross-sections through the inlet 
and/or outlet can be adjusted. For example, a regulating valve according 
to the invention can be arranged in liquid circulation circuits to connect 
various interconnected partial areas of the circulation circuit. The 
actuation of the valve body with an electrically operated stepping motor 
is particularly advantageous for such applications, since a very exact 
regulation of the liquid distribution within the circulation circuit can 
be carried out depending upon the characteristic data in the regulating 
device. 
Actuation of the valve body is likewise possible by means of 
electromagnetically, pneumatically or hydraulically operated actuator 
elements. For example, a particularly simple and economically 
cost-effective actuation of the valve body can be carried out by means of 
an element made of expansion material, the valve body, depending upon the 
temperature with which the expansion material element is acted upon, 
releasing the passage cross-section through the inlet and/or the outlets. 
For instance, the actuation of the valve body can then be regulated by the 
temperature of the flowing medium. 
The inlet and the outlets are capable of being brought into sealing 
engagement with the valve body, which is rotatable around its axis, by 
sealing devices, the sealing devices having to seal both statically and 
dynamically. With frequent actuation of the valve body, durable seals 
which exhibit only slight wear over the entire operating life are 
advantageous. To achieve excellent sealing results over the entire 
operating life, the seals can be formed by ring-shaped premolded seals 
made of PTFE and can be supported on the side facing away from the valve 
body in an elastically flexible manner on a spring element in the axial 
direction of the premolded seal. In doing this, it is an advantage that, 
in spite of a good sealing of the inlet and/or the outlets against the 
relatively rotatable valve body, excellent smooth relative mobility is 
retained. Because of the elastic flexibility in the axial direction of the 
premolded seal, the premolded seal made of PTFE is sealingly engaged with 
the valve body and optimally allocated to it even when, subject to 
manufacturing and/or assembly, the housing and valve body are not 
absolutely exactly concentrically aligned. 
The spring element can be formed, for example, by an O-ring made of 
elastomeric material. O-rings are parts which are economically available 
in nearly all desired dimensions. A regulating valve according to the 
invention can be constructed with a comparatively low weight and can be 
economically produced in large quantities. The housing can have, for 
example, one inlet and three outlets, such an embodiment being 
particularly useful when the regulating valve is used in cooling systems 
of combustion engines. 
The duct-shaped opening through the valve body can have an essentially 
circular cross-section and can extend in an essentially curved manner 
around the axis. In view of the desirability of having a mass inertia 
which is as low as possible and an actuation of the valve body by starting 
torque which is as low as possible, the valve body may consist of a light 
metal alloy. An essentially circular cross-section, extending in a curved 
manner around the axis of the valve body and being smooth and continuous 
without abrupt changes in direction, allows exceptionally effective flow. 
By the avoidance of turbulence within the opening, cavitation is avoided. 
Thus the regulating valve exhibits uniformly good operating 
characteristics during its entire service life. 
A regulating valve according to the invention may be used, for example, in 
a liquid cooling system of a combustion engine. The inlet may be connected 
with the coolant outlet of the combustion engine, with the outlets 
connected to the radiator circulation circuit, the bypass circulation 
circuit and the circulation circuit for the heating of the vehicle 
passenger compartment. The outlet to the radiator circulation circuit on 
the one side and the outlet to the passenger compartment heating 
circulation circuit on the other side are adjacent to the inlet in the 
circumferential direction of the valve chamber. The inlet and the outlets 
for the radiator and passenger compartment heating may be completely 
closed simultaneously, with the outlet of the bypass circulation circuit 
only completely closed by the valve body when the inlet and the outlets 
adjacent on both sides in the circumferential direction are completely 
open. 
Instead of the heating circulation circuit, in the case of corresponding 
cooling systems the oil/water heat exchanger can be connected. By the use 
of a regulating valve according to the invention, a liquid cooling system 
design for combustion engines using particularly few parts is possible. A 
regulating valve is simply used in order to control all the circulation 
circuits of the cooling system depending upon, for example, the component 
temperature of the cylinder head and/or the coolant temperature. The 
passage cross-section through the inlet into the valve chamber and through 
the outlets out of the valve chamber into the adjacent circulation 
circuits can be adjusted easily to the respective conditions of the 
application by the continuously operable valve body. 
When the regulating valve is used in the liquid cooling system of a 
combustion engine, it has proven to be advantageous to allocate a 
resetting spring to the valve body which, for example, in the event of the 
loss of actuation, brings the valve body into a position in which the 
associated engine suffers no damage. For instance, such a position is set 
in when the valve body completely releases the inlet into the valve 
chamber and the outlet to the radiator and to the vehicle passenger 
compartment heating and completely closes the bypass circulation circuit. 
An overheating of the associated engine is then reliably prevented. 
By the integration of the heating circulation circuit into the regulating 
valve, it is possible to prevent circulation of the coolant in the warm-up 
phase, since during the warm-up phase no circulation of the coolant takes 
place through the vehicle passenger compartment heating circulation 
circuit. For example, the actuation of the regulating valve can be 
effected by an electrically driven stepping motor which is linked in a 
signal-conductive manner to the electronic valve timing of a combustion 
engine. Depending upon parameters which are stored for the electronic 
valve timing, the coolant temperature during the operation of the 
combustion engine can be adjusted by way of the volumetric flow through 
the cooling system. In this manner, it is possible to reduce fuel 
consumption and emissions. Also, a component temperature control, for 
instance a temperature control of the cylinder head, is possible.

DETAILED DESCRIPTION OF DRAWINGS 
In FIG. 1, an embodiment of a regulating valve according to the invention 
is shown, which is used for regulating the flow of coolant through the 
liquid cooling system of a combustion engine. The regulating valve 
comprises essentially a hollow cylindrical housing 1, which encloses a 
valve chamber 2, with a valve body 8 being arranged inside the valve 
chamber 2. The valve body 8 is connected to a drive axle 20 and is 
rotatable around the axis 7 by an actuator 9, shown schematically in FIG. 
1. 
The valve chamber 2 is sealed with respect to the surroundings and the 
valve body 8. The connections to the housing 1, which are formed by the 
inlet 3 and three outlets not pictured in FIG. 1, are designed as pipe 
sockets which are joined to the housing 1 in a liquid-tight manner. The 
sealing of the pipe sockets with respect to the valve body 8 is effected 
on the side facing the valve body 8 by a sealing device 10, which is 
manufactured as a premolded part from PTFE, the sealing device 10 being 
supported in an elastically flexible manner in axial direction of the pipe 
socket on a spring element 19 designed as an O-ring. (The sealing device 
10 and the compressed spring element 19 in the form of an O-ring are shown 
more clearly in the enlarged view A in FIG. 2) 
The guidance of the drive axle 20 within the housing 1 takes place in 
sliding sleeves 21 in order to ensure a relative mobility of the valve 
body 8 in relation to the housing 1 that is as low-friction as possible. A 
duct-shaped opening 16 is provided within the valve body 8. In this 
embodiment the duct-shaped opening 16 has an oval cross-section. 
In FIG. 2, the regulating valve shown in FIG. 1 is shown in cross-sectional 
representation. The regulating valve is provided with an inlet 3 which in 
this embodiment is connected with the coolant outlet of a combustion 
engine (not shown). The outlets 4, 5 and 6 connect the valve chamber 2 to 
the radiator circulation circuit, the bypass circulation circuit and the 
vehicle passenger compartment heating circulation circuit of the cooling 
system, respectively. A limit stop 22 is provided as a rotation boundary 
of the valve body 8. Because of the elastic flexibility of the spring 
elements 19 (designed as O-rings), the sealing devices 10 consisting of 
PTFE of the inlet 3 and the outlet 4 are sealingly engaged with the 
surface of the valve body 8 under elastic preload. The operating state 
pictured here, in which the inlet 3 is blocked, causes a short warm-up 
phase and a quick warming of the combustion engine after the cold start. A 
circulation of the coolant through the cooling system of the combustion 
engine does not take place. It can be seen that the duct-shaped opening 16 
extends in an essentially curved manner around the axis 7 of the valve 
body 8 and penetrates the boundary surfaces comprised of the two 
peripheral sides 11, 12. 
In FIG. 3, the regulating valve is shown in an operating state different 
from FIG. 2. With increasing heating of the coolant and/or the components 
of the engine, the valve body 8 moves clockwise from the limit stop 22 in 
a direction which opens the inlet 3, until the entire opening 
cross-section of the inlet 3 is clear. The geometry of the valve body 8 
and the arrangement of the inlet 3 relative to the outlets 4, 5, 6 brings 
about the result that, with the completely open inlet, the outlet 5 to the 
bypass circulation circuit and the outlet 6 to the heating circulation 
circuit are also completely open. The outlet 4 is still closed in the 
direction of the radiator circulation circuit by the valve body 8 in order 
to continue to achieve a quick warming of the engine to the optimum 
operating temperature. 
The configuration of the valve body 8 is of an importance to be emphasized. 
Starting from the operating state of the regulating valve represented in 
FIG. 2, the valve body 8 in FIG. 3 is rotated relative to the housing and 
causes a gradual opening of the inlet 3. In order upon opening the inlet 3 
to prevent a sudden enlargement of the cross-section and an abrupt 
acceleration of the flow and because of this a decrease of the static 
pressure, and to keep the starting torque for actuating the valve body 8 
as low as possible, the efflux edge 13 is provided with an elliptical 
recess 15 (see FIG. 6) and the duct-shaped opening 16. With this 
construction, suction effects which cause a moment of rotation on the 
valve body 8 contrary to the opening direction are reduced when opening 
the inlet 3. Besides a more uniform opening characteristic of the valve 
accompanied by comparatively low actuating forces by the actuator 9, the 
opening 16 brings about an additional reduction of the starting torque 
needed because the flow relative to the turning center point of the valve 
body 8 is substantially symmetrical. 
In FIG. 4, the temperature of the coolant and/or the temperature of the 
components arranged within the combustion engine has further increased and 
the valve body 8 is moved further in the clockwise direction by the 
actuator 9 until the edge 13 which forms the efflux edge frees a section 
of the cross-section of the outlet 4 and the edge 14 opposite in 
circumferential direction closes a section of the outlet 5 to the bypass 
circulation circuit. A part of the coolant circulating in the cooling 
system reaches the radiator through the outlet 4 and is subsequently fed 
again, cooled, to the combustion engine. 
In FIG. 5, an operating state of the regulating valve is shown which 
occurs, for instance, when the combustion engine is operated at full load 
and the maximum cooling performance is required. The edge 14 of the valve 
body 8 is engaged with the limit stop 22, and the valve body 8 completely 
and sealingly covers the outlet 5 of the bypass circulation circuit. In 
order to achieve maximum cooling performance, the outlet 4 to the radiator 
is completely open. In this operating state, the coolant supplied through 
the inlet 3 into the regulating valve 1 is distributed proportionally to 
the vehicle passenger compartment heating circulation circuit and the 
radiator circulation circuit. The valve body 8 according to the invention 
turns out to be especially advantageous when a high volumetric flow, 
pumped through the cooling system, is necessary to cool the combustion 
engine. The elliptical recess 15, in conjunction with the duct-shaped 
opening 16, causes the valve body 8 to be movable by low starting torque 
of the actuator 9. 
In FIG. 6, the valve body 8 from FIGS. 1 through 5 is shown in perspective 
representation. As shown in FIG. 6, the valve body 8 is shaped 
substantially in the form of a segment of a cylinder, having a bottom side 
17 and a top side 18 comprising axial boundaries, an outer curved side 23, 
and two peripheral sides 11, 12 comprising boundary surfaces. Each 
peripheral side 11, 12 has an outside edge 13, 14 facing the housing. The 
outside edge 13 of the peripheral side 11, which is designed as the efflux 
edge, has an elliptical recess 15 which extends in the axial direction 
between the axial boundaries 17, 18 of the valve body 8. The opening 16 is 
not seen in this representation. 
A regulating valve V according to the invention may be used, for example, 
in a liquid cooling system of a combustion engine, shown schematically in 
FIG. 7. In this embodiment, the inlet 3 of the regulating valve V is 
connected with the coolant outlet of the combustion engine, with the 
outlets 4, 5, 6 connected to the radiator circulation circuit, the bypass 
circulation circuit and the circulation circuit for the heating of the 
vehicle passenger compartment. The outlet 6 to the radiator circulation 
circuit on the one side and the outlet 4 to the passenger compartment 
heating circulation circuit on the other side are adjacent to the inlet 3 
in the circumferential direction of the valve chamber. The inlet 3 and the 
outlets 6, 4 for the radiator and passenger compartment heating may be 
completely closed simultaneously, with the outlet 5 of the bypass 
circulation circuit only completely closed by the valve body when the 
inlet 3 and the outlets 6, 4 adjacent on both sides in the circumferential 
direction are completely open.