Technical field
[0001] The invention relates to a valve for regulating a flow cross section in a throttle
flap connector, having a throttle flap which is mounted in the throttle flap connector
so as to be rotatable about an axis of rotation, wherein the throttle flap is rotatable
about the axis of rotation, by means of an actuator which acts on the throttle flap,
counter to a force generated by a mechanical spring, wherein the maximum angle of
rotation of the throttle flap in the throttle flap connector is limited by stops.
Prior art
[0002] Throttle flaps are used for example in the intake tract of internal combustion engines
for the purposes of regulating the air quantity to be supplied to the combustion chamber.
Through the use of a throttle flap, it is possible in particular for the supplied
air quantity to be adapted to the supplied fuel quantity, and/or for an air-fuel mixture
suitable for the respective load state of the internal combustion engine to be generated.
[0003] Throttle flaps in throttle flap connectors are known.
DE 195 12 729 A1 describes a throttle flap connector with a tubular housing in which a throttle flap
is fastened to a throttle flap shaft which, at its free ends led through recesses
in the housing wall, is mounted so as to be rotatable transversely with respect to
the longitudinal axis of the tubular housing.
[0004] Throttle flaps can be rotated in their throttle flap connector by means of an actuator,
such as for example an electric motor. As a result of the rotation of the throttle
flap relative to the throttle flap connector, the flow cross section of the throttle
flap connector can be increased and decreased in size. Often, throttle flaps are designed
so as to be held open by a mechanical spring when not acted on by the actuator. Here,
the actuator is used to close the throttle flap, through the application of a force,
counter to the spring force acting on said throttle flap.
[0005] A disadvantage of devices in the prior art is in particular that the positioning
of the throttle flap in a defined position, for example in a so-called home position
or safety position, in which the throttle flap is open to a minimal extent, is possible
only with the aid of mechanical stops or with the aid of active elements such as for
example actuators.
Presentation of the invention, problem, solution, advantages
[0006] Therefore, the problem addressed by the present invention is that of creating a throttle
flap arranged in a throttle flap connector, which throttle flap serves as a valve
for a flow, wherein the throttle flap is fixable in at least one defined position,
wherein the fixing is possible in particular even in a deenergized state.
[0007] The problem is solved, with regard to the valve, by means of a valve having the features
of claim 1.
[0008] An exemplary embodiment of the invention relates to a valve for regulating a flow
cross section in a throttle flap connector, having a throttle flap which is mounted
in the throttle flap connector so as to be rotatable about an axis of rotation, wherein
the throttle flap is rotatable about the axis of rotation, by means of an actuator
which acts on the throttle flap, counter to a force generated by a mechanical spring,
wherein the maximum angle of rotation of the throttle flap in the throttle flap connector
is limited by stops, wherein the throttle flap, in at least a first position, is fixable
in said first position by means of a magnet device, wherein the magnet device is formed
by a first permanent magnet in the housing of the throttle flap connector, and a second
permanent magnet is formed on the throttle flap, wherein the permanent magnets are
oriented relative to one another such that those ends of the permanent magnets which
are of the same polarity are directed toward one another.
[0009] The at least first position may vary depending on the construction of the valve and
in particular the arrangement and functioning of the mechanical spring and of the
actuator. In a first embodiment, the mechanical spring acts on the throttle flap such
that the flow cross section of the throttle flap connector is opened up when no force
is transmitted from the actuator to the throttle flap. The mechanical spring thus
rotates the throttle flap such that the valve is opened. This is advantageous because
it is thereby ensured that, even in the event of a failure of the actuator, the throttle
flap is opened in order to permit at least emergency operation of a downstream internal
combustion engine. In this embodiment, the actuator is used to rotate the throttle
flap counter to the mechanical spring such that the flow cross section is decreased
in size or is closed entirely.
[0010] In a further embodiment, the operating principle of the mechanical spring and of
the actuator may be implemented in reverse fashion, whereby the throttle flap is closed
by the mechanical spring and is opened by the actuator counter to the action of the
mechanical spring.
[0011] In both embodiments, the magnet device can be used in an effective manner. In the
first case, the magnet device prevents the throttle flap from being completely closed
by the actuator if the force generated by the magnet device in combination with the
mechanical spring is greater than that of the actuator. Also, the magnet device may
in this case act as a type of stop damper if the force of the actuator is greater
than that of the magnet device.
[0012] In the second case, the magnet device may contribute to a situation in which the
throttle flap rotated by the mechanical spring in the direction of a closed position
is not fully closed if the force of the magnet device is greater than that of the
mechanical spring. Here, the throttle flap is at all times held in a position in which
at least a minimal flow cross section of the throttle flap connector remains open.
Such a position is known for example as a rest position or emergency position, because
it ensures a certain minimum functionality of the valve even in the event of failure
of the actuator, because at least a minimal flow cross section remains for a passage
of flow.
[0013] The magnet device may advantageously also be integrated into the valve so as to act
as a stop damper even in the open position of the throttle flap.
[0014] It is particularly advantageous if the throttle flap, in the first position, opens
up a defined flow cross section in the throttle flap connector. This is advantageous
for ensuring a certain minimum throughput through the valve at all times. In the case
of a completely closed throttle flap, it would not be possible for any air mixture
to be supplied to the internal combustion engine, whereby operation would be rendered
impossible.
[0015] It is also advantageous if the flow cross section of the throttle flap connector
can be reduced in size by the throttle flap by means of the mechanical spring counter
to the force that can be generated by the actuator, wherein the magnet device prevents
a complete closure of the flow cross section of the throttle flap connector. This
is advantageous because, in such an embodiment, the magnet device ensures that the
throttle flap cannot be rotated into a fully closed position.
[0016] A preferred exemplary embodiment is characterized in that at least one of the permanent
magnets is surrounded by means for directing the magnetic field, wherein said means
are formed by metal plates which at least partially enclose the permanent magnets.
Such means for directing the magnetic field are advantageous because, by means of
these, the action of the respective permanent magnets can be improved. As a result
of the directing of the magnetic field, the force of the permanent magnets can be
considerably increased, whereby, with an unchanged magnet size, greater forces can
be generated, or alternatively, smaller permanent magnets can be used.
[0017] It is also preferable if the means for directing the magnetic field are formed by
steel plates. Steel plates are, owing to their material characteristics, particularly
well-suited for directing magnetic field lines.
[0018] It is furthermore advantageous if the second permanent magnet arranged on the throttle
flap is movable on a circular path formed around the axis of rotation of the throttle
flap, wherein the spacing between the first permanent magnet and the second permanent
magnet in a circumferential direction along the circular path is defined by the angle
of rotation of the throttle flap relative to the throttle flap connector. This is
advantageous for ensuring that the permanent magnets are moved toward one another
or away from one another as a result of the rotation of the throttle flap, whereby
the function of said permanent magnets is ensured.
[0019] It is furthermore advantageous if the second permanent magnet is part of the toothed
ring by means of which the movement of the actuator can be transmitted to the throttle
flap. This is advantageous because the movement of the throttle flap thus leads directly
to a movement of the permanent magnet.
[0020] It is also expedient if the throttle flap is rotatable between two maximum positions,
wherein, in the first maximum position, the throttle flap closes the flow cross section
of the throttle flap connector, and in the second maximum position, the throttle flap
opens up the flow cross section of the throttle flap connector. The throttle flap
is advantageously designed such that complete closure of the throttle flap is prevented
in order that a minimum functionality of the valve is maintained even in the event
of a defect, for example in the event of failure of the actuator.
[0021] It is also advantageous if the throttle flap, in the first position in which it is
fixable by means of the magnet device, incompletely closes the flow cross section
of the throttle flap connector and holds a minimum flow cross section open. This is
advantageous for ensuring that, even in the event of a defect, a minimum quantity
of air can pass into the combustion chamber of the downstream internal combustion
engine and thus ensure at least emergency operation. This applies in particular to
an embodiment of the valve in which the mechanical spring would lead to complete closure
of the throttle flap in the event of failure of the actuator.
[0022] It is furthermore expedient if the force generated by the magnet device for holding
the throttle flap in the first position is at least equal to or greater than the force
generated by the mechanical spring. This is advantageous for ensuring that the throttle
flap would not be pushed into a fully closed position counter to the magnetic forces.
[0023] It is furthermore advantageous if the two permanent magnets are arranged on a common
circular path, wherein the first permanent magnet is connected positionally fixedly
to the housing of the throttle flap connector, and the second permanent magnet is
rotatable with the throttle flap along the circular path. In this way, it is ensured
that the magnets are moved toward one another or away from one another in controlled
fashion as a result of the rotation of the throttle flap.
[0024] It is also preferable if the force generated by the magnet device between the permanent
magnets of the throttle flap and of the throttle flap connector counteract the force
generated by the actuator. This is advantageous if the valve is designed such that
the mechanical spring opens the throttle flap and the actuator acts counter to this.
The actuator thus closes the throttle flap as far as a point at which the closing
force of the actuator is equal to the repelling forces between the two permanent magnets.
[0025] Advantageous refinements of the present invention are described in the subclaims
and in the following description of the figures.
Brief description of the drawings
[0026] Below, the invention will be discussed in detail on the basis of an exemplary embodiment
and with reference to the drawing, in which:
- figure 1
- shows a perspective view of a detail of the valve according to the invention, wherein
the upper part of the figure shows the two permanent magnets, and the lower part of
the figure is a schematic illustration of the magnetic field generated by the permanent
magnets.
Preferred embodiment of the invention
[0027] Figure 1 shows, in the upper part, a detail view of the valve 1, wherein the illustration
shows substantially the housing 2 of the throttle flap connector, the mechanical spring
3 and the toothed ring section 4 which transmits the movement of the actuator (not
shown) to the throttle flap (likewise not shown).
[0028] A permanent magnet 5 is arranged at the free end region of the toothed ring section
4. A further permanent magnet 7 is arranged in a receptacle 6 of the housing 2.
[0029] The two permanent magnets 5 and 7 are oriented relative to one another such that
in each case the identical magnetic poles point toward one another. This has the effect
that the two permanent magnets 5 and 7 repel one another when they are moved close
enough to one another.
[0030] The toothed ring section 4 is rotated by an actuator in order to move the throttle
flap that is attached to the toothed ring section 4. Here, the throttle flap and the
toothed ring section 4 preferably rotate about a common axis of rotation. The permanent
magnet 5 thus moves on a circular path defined by the toothed ring section 4. The
second permanent magnet 7 is preferably likewise arranged on said circular path in
order to ensure that the two permanent magnets 5, 7 can be moved toward one another
or away from one another as a result of the rotation of the throttle flap.
[0031] If the two permanent magnets 5, 7 have been moved close enough to one another, they
repel one another owing to the orientation of the permanent magnets 5, 7, and thus
generate a spacing between themselves. The toothed ring section 4 and thus the attached
throttle flap are thereby fixed in a position.
[0032] Depending on the construction of the valve and in particular on the direction of
action of the mechanical spring 3 and of the force imparted by the actuator, it is
thus possible for the throttle flap to be fixed in a slightly open position or in
a fully open position.
[0033] The force generated by the repulsion of the permanent magnets 5, 7 may be used both
for opening the throttle flap and for closing the latter. This is dependent substantially
on the directions of action of the actuator and of the mechanical spring 3.
[0034] The magnet device 5, 7 may also be used as a stop damper if the force component that
moves the toothed ring section in the direction of the second permanent magnet 7 is
correspondingly dimensioned so as to overcome the repulsion force. In such a situation,
the toothed ring section 4 is braked by the repulsion force and is moved as far as
a physical stop by the relatively high actuation force counter to the repulsion action.
[0035] If the repulsion force is greater than the actuation force that the toothed ring
section 4 imparts to the second permanent magnet 7, the movement of the toothed ring
section 4 is ended, possibly with slight overshoots, before the toothed ring section
4 abuts against the housing 1.
[0036] Depending on the manner in which the individual force components of the mechanical
spring 3, of the actuator and of the magnetic repulsion are directed and thus act
on the throttle flap, corresponding functionality can be realized. Here, the common
functionalities include stop damping and fixing in a defined position, in which the
throttle flap is at least slightly open.
[0037] The lower part of figure 1 shows a diagrammatic sketch of two permanent magnets,
showing the arrangement of the equal magnetic poles toward one another. The permanent
magnets 5, 7 in the upper part of figure 1 are arranged in the same manner as in the
diagrammatic sketch.
[0038] The exemplary embodiment of figure 1 is in particular not of a restrictive nature,
and serves for illustrating the concept of the invention.
1. A valve (1) for regulating a flow cross section in a throttle flap connector, having
a throttle flap which is mounted in the throttle flap connector so as to be rotatable
about an axis of rotation, wherein the throttle flap is rotatable about the axis of
rotation, by means of an actuator which acts on the throttle flap, counter to a force
generated by a mechanical spring (3), wherein the maximum angle of rotation of the
throttle flap in the throttle flap connector is limited by stops, characterized in that the throttle flap, in at least a first position, is fixable in said first position
by means of a magnet device (5, 7), wherein the magnet device (5, 7) is formed by
a first permanent magnet (5) in the housing (2) of the throttle flap connector, and
a second permanent magnet (7) is formed on the throttle flap, wherein the permanent
magnets (5, 7) are oriented relative to one another such that those ends of the permanent
magnets (5, 7) which are of the same polarity are directed toward one another.
2. The valve (1) as claimed in claim 1, characterized in that the throttle flap, in the first position, opens up a defined flow cross section in
the throttle flap connector.
3. The valve (1) as claimed in one of the preceding claims, characterized in that the flow cross section of the throttle flap connector can be reduced in size by the
throttle flap by means of the mechanical spring (3) counter to the force that can
be generated by the actuator, wherein the magnet device (5, 7) prevents a complete
closure of the flow cross section of the throttle flap connector.
4. The valve (1) as claimed in one of the preceding claims, characterized in that at least one of the permanent magnets (5, 7) is surrounded by means for directing
the magnetic field, wherein said means are formed by metal plates which at least partially
enclose the permanent magnets (5, 7).
5. The valve (1) as claimed in claim 4, characterized in that the means for directing the magnetic field are formed by steel plates.
6. The valve (1) as claimed in one of the preceding claims, characterized in that the second permanent magnet (7) arranged on the throttle flap is movable on a circular
path formed around the axis of rotation of the throttle flap, wherein the spacing
between the first permanent magnet (5) and the second permanent magnet (7) in a circumferential
direction along the circular path is defined by the angle of rotation of the throttle
flap relative to the throttle flap connector.
7. The valve (1) as claimed in one of the preceding claims, characterized in that the second permanent magnet (7) is part of the toothed ring (4) by means of which
the movement of the actuator can be transmitted to the throttle flap.
8. The valve (1) as claimed in one of the preceding claims, characterized in that the throttle flap, in the first position in which it is fixable by means of the magnet
device (5, 7), incompletely closes the flow cross section of the throttle flap connector
and holds a minimum flow cross section open.
9. The valve (1) as claimed in one of the preceding claims, characterized in that the force generated by the magnet device (5, 7) for holding the throttle flap in
the first position is at least equal to or greater than the force generated by the
mechanical spring (3).
10. The valve (1) as claimed in one of the preceding claims, characterized in that the two permanent magnets (5, 7) are arranged on a common circular path, wherein
the first permanent magnet (5) is connected positionally fixedly to the housing (3)
of the throttle flap connector, and the second permanent magnet (7) is rotatable with
the throttle flap along the circular path.
11. The valve (1) as claimed in one of the preceding claims, characterized in that the force generated by the magnet device (5, 7) between the permanent magnets (5,
7) of the throttle flap and of the throttle flap connector counteract the force generated
by the actuator.