DE19720849A1 - Piezo-valve with two stable positions, for use in miniature systems - Google Patents

Abstract

The valve has a casing (1) with an internal element (13) which can be switched between two positions (14,15) against fixed supports (7',9'). The element has an elongated support (18) which is mounted so that it can be deflected across its longitudinal direction (20). The support has two suspension parts (21,22) which are located on each side of the element with a separation in the longitudinal direction, in order to support it from two positions (23,24) which lie on opposite walls of the casing across the switching direction (17). At least one elongated section of the support is formed by spring equipment (32). The separation between the mounting positions is chosen so that the support adopts a shape in each switching position which curves towards the associated fixed support, and is stabilised by the spring equipment.

Description

The invention relates to a valve with one in a Ventilge housing arranged closure body which between two switching positions can be switched, in which it is on one housing tight support part rests, with the closure body an elongated carrier is provided which with a Longitudinal distance to the closure body arranged suspension part is stored at a housing-side bearing point and for order switch the closure body transversely to its longitudinal direction is steerable, with a loading and the closure body in at least one of its switching positions biasing spring device and with an actuator for deflection of the carrier for the purpose of switching the closure body.

A valve of this type is known for example from DE 36 08 550 A1. The valve described there is a piezo valve trained and has one sided on a bearing place clamped on the housing side, the free end carries the closure body. A spring on the side direction clamps the closure body in a first switching position lung in which it is formed on a valve seat  Support section rests. A pie is used as the actuating device zoeinrichtung provided, the activation of the carrier is deflected into a second switching position by bending, in which he is also formed by a valve seat second support section is present. If the piezo device becomes deak tiviert, the spring device causes an automatic closing switch the closure body back to the starting position.

The known valve is already relatively good for one Miniaturization. The disadvantage, however, is that the shawl th of the valve and especially for holding the breech body pers in the switching position deflected against the spring force a considerable amount of electrical energy is required is.

It is therefore the object of the present invention to Miniaturization to create a suitable valve in which to be used operation and to maintain the desired switching point little energy is needed.

To solve this problem it is provided that the carrier about has two suspension parts related to the Longitudinal direction of the carrier with a distance to both sides of the ver closing body and over which the carrier at two transversely to the switching direction of the closure body at a distance GE opposite bearing points on the housing is suspended, that at least a length of the beam from the spring direction is formed, and that the distance between the hous side bearings is chosen so that the carrier in the  two switch positions of the closure body one with respect to Connection line between the bearing points in the changeover direction bulged or buckled towards the assigned support section te takes shape, each by the spring device is stabilized.

In this way, there is a valve that is especially for small sizes is predestined because of its energy absorption is low. The valve has a bistable switchover mechanism, wherein a single spring device is sufficient to to stabilize the two switch positions. The carrier is fully or partially designed as a spring device, wherein due to a correspondingly small distance between the housings side bearings in both possible switch positions elastic preload is achieved. In the respective Switch position, the carrier has a related to the ge figured out the connecting line between the bearings arched or bent shape, the closure body is pressed against the support section. During the switchover movement if the carrier passes through a kind of dead center by deformation, so that with a suitable design a kind of snap action can take place. In all of this, the one for switching the ver closing body relatively low on energy to be applied.

Advantageous developments of the invention are in the Unteran sayings listed.  

Basically, there are alternative options, the Trä either in its entirety or only partially as a feather furnishing.

If only part of the carrier is formed by the spring device, a compression spring is expediently used as the spring device direction provided in the longitudinal course of the carrier is turned on that their main suspension direction in the longitudinal direction direction of the carrier runs. Here it is particularly advantageous if the spring device in the on one side of the Closure body located length portion of the carrier be finds and in particular this one length section overall forms, the one on the opposite side of the ver final body located a particular section rigid support section can be at the bearing is pivotally suspended. To move the closure body switch, can be a short here by the actuator impulsive lateral impact on the carrier or the ver closing body are exercised, which ensures that the carrier shifted over the dead center into the other switching position becomes. The impact accelerates the wearer who is there after due to its inertia the spring force and can overcome any upcoming media pressure. Once the Dead center is exceeded, the spring device itself acts as a loading device to completely insert the valve body into the to spend another switching position.

The actuating device can be arranged via a tappet have, in particular two actuators, each with egg  Nem plunger are present in one or the other whose direction can act on the valve body. The fault ßelhub can be much less than the switching path of the closure body when the operating speed of the Plunger is correspondingly large. This can, for example, under Use of magnetic coils with overexcitation or piezo translators can be achieved. What is essential is that per switch Gang supplied energy, which is particularly from the mass and the geometrical data of the carrier and the closure body pers, from the biasing force of the spring device and its Spring characteristic and the media pressure can be calculated. This Ener gie is relatively low here.

In one trained as a spring device in its entirety ten carrier it is appropriate to use the carrier as a leaf spring-like che, transverse to the longitudinal elastic bending spring arrangement to train. It can be provided here that the spiral spring order in neutral position has a linear extension and practically along the imaginary connecting line between the Bearings runs. By reducing the distance between the bearing points by means of a suitable actuation direction can the spiral spring arrangement in a first switching position be arched out laterally. To switch is then only briefly on the movable bearing on the carrier acting holding force to cancel, so that the carrier finally the closure body in the direction of the neutral position lung is bent back, with this one dead center marking neutral position swings out. By immediately then the holding force mentioned is again applied,  the closure body can be completely in the other switching shift position and hold there.

Here, the axial preload is practically elastic knocked out carrier for the period of time that the Carrier needs the neutral position due to its springback to achieve. Overcoming the neutral position can again with the participation of the kinetic energy of the wearer and the closure body can be reached. It is sufficient here if the actuating device has only one actuator in Shape of a suitable adjusting device, which either is controlled accordingly or because of its Eigenfre quenz is appropriately coordinated.

The invention based on the accompanying drawing tion explained in more detail. In this show:

Fig. 1 shows a first design of the valve of the invention with a partially from a Federeinrich tung carriers formed in a schematic longitudinal sectional view,

Fig. 2 shows a further design of the Ven valve according to the invention with a support designed entirely as a spring device, again in a schematic table, but showing only a section of the valve, longitudinal sectional view.

Both valves shown have a valve housing 1 with a valve chamber 2 located inside. The valves are designed as 3/2-way valves and have three fluid channels 3 , 4 , 5 , which on the one hand on the outer surface of the Ven tilgehäuses 1 and on the other hand open into the valve chamber 2 .

One fluid channel 3 is a feed channel. He is normally ruled out to a particular source of pneumatic pressure fluid. The valve chamber 2 associated mouth 6 of this Spei channel is surrounded by a first valve seat 7 , which can be formed by a collar-like annular housing jump for example.

Another fluid channel 4 is a ventilation channel. For example, a silencer can be connected to it. An orifice 8 associated with the valve chamber 2 is at a distance from the orifice 6 of the fluid channel 3 . It is also surrounded by an annular valve seat 9 . The two valve seats 7 , 9 are located on opposite walls of the valve chamber 2 .

The third fluid channel 5 is a working channel. A consumer to be supplied with the fluidic pressure medium can be connected to it. Its associated with the valve chamber 2 Mün manure 12 is apart from the other mouths 6 , 8th

A movable closure body 13 is arranged in the valve chamber 2 . For example, it has a plate-like or pill-like shape. In both figures, the closure body is shown by 13 in solid lines in a first switch position 14 , in which it rests on the valve seat 9 of the fluid channel 4 and closes the associated mouth 8 in a fluid-tight manner. The Ven tilsitz 9 forms a support section for the closure body 13th

With the help of an actuating device 16 , 16 ', the closure body 13 can be switched by shifting from the first switching position 14 into a second switching position 15 indicated by dash-dotted lines in the figures. In the second switching position 15 , it rests on the also a support section 7 'form the other valve seat 7 and closes the associated and previously open mouth 6 of the fluid channel 3 fluid tight. At the same time, the closure body 13 is lifted from the other valve seat 9 , so that the mouth 8 of the fluid channel 4 is released.

The switching direction of the closure body 13 at the transition between the two switching positions 14 , 15 is indicated by double arrow 17 . In the valve design shown, there is a fluid connection between the feed channel 3 and the working channel 5 in the most switching position via the valve chamber 2 . At the same time, the ventilation duct 4 is blocked. In the second switching position, the feed channel 3 is shut off, while at the same time the working channel 5 communicates with the venting channel 4 via the valve chamber 2 , so that the consumer is vented.

The closure body 13 is seen on an elongated carrier 18 , which is also located in the valve chamber 2 . The water carrier 18 has at its two opposite ends th narrow ends each have a suspension section 21 , 22 with which it hangs up or is supported on a housing-side bearing 23 , 24 . The arrangement is such that an imaginary, dash-dotted line in the figures Ver connecting line 25 between the two bearing points 23 , 24 transverse and in particular at least substantially perpendicular to the switching direction 17 . For example, the bearings are placed 23 , 24 opposite walls 26 of the Ventilkam mer 22 , which extend transversely to the mutually opposite and also the mouths 6 , 8 having other walls 29 .

The closure body 13 is arranged with a longitudinal distance measured in the longitudinal direction 20 between the two suspension parts 21 , 22 between the sen. As a result, there is a carrier section 27 , 28 on both sides of the closure body 13 , which produces the connec tion between the closure body 13 and the suspension section 21 , 22 or the bearing point 23 , 24 concerned.

The closure body 13 can, as shown in Fig. 1, be inserted in the longitudinal course 20 of the carrier 18 , so that it practically forms part of the carrier itself. However, the variant shown in FIG. 2 is also possible, for example, in which the carrier 18 is a strand body which runs between the two suspension parts 21 , 22 and carries the closure body 13 . Here it is useful to provide a multi-part closure body 13 which has two closure body parts that sit on the two longitudinal sides of the carrier 18 facing a respective valve seat 7 , 9 .

It is advantageous if the closure body 13 is arranged at least approximately in the middle between the suspension parts 21 , 22 .

As is clear from the figures, the distance measured in the direction of the connecting line 25 between the two La gerstellen 23 , 24 is chosen so that the carrier in both switching positions 14 , 15 of the closure body 13 takes a shape in which he laterally in Switching direction 17 from the Ver connecting line 25 is arched or buckled. Whether it is more of a buckling or a bulge essentially depends on the design of the carrier 18 . In the case of FIG. 2 there is rather an arched bulge, while in the case of FIG. 1 it is more of a buckling.

The respective curved or bent shape is stabilized by a spring device 32 , 32 '. This Federeinrich device 32 , 32 'takes over its stabilization task advantageously in both switching positions 14 , 15 , whereby it causes the closure body 13 against the respectively associated and example formed by a valve seat 7 , 9 support part 7 ', 9 'is pressed. It is not an additional Lich provided to the carrier 18 spring device 32 , 32 ', son, it is rather at least a longitudinal section of the carrier 18 itself formed by the spring device 32 . The result is a small number of components.

In the embodiment shown in Fig. 1, only a certain water, extending in the longitudinal direction 20 part of the carrier 18 is formed by the spring device 32 . This is preferably a carrier section 28 which extends between the closure body 13 and the one suspension part 22 . The spring device 32 is here preferably designed as a compression spring device 33 which is designed in the manner of a screw spring device and which engages on one end on the closure body 13 and on the other hand on the bearing point 24 . In this way, its main suspension device 34 coincides with the longitudinal direction of the carrier 18 .

The oppositely arranged other carrier section 27 is, for example, rigid in itself, a rigid connection also preferably being present between the carrier section 27 and the closure body 13 . With its opposite, the mounting section 21 forming the end of the support portion, however, is pivotally mounted on the associated bearing point 23 27, so that the support portion 27 is pivotally bar in a plane which is spanned by the two openings 6, 8 and the bearing point 23rd

The distance between the two bearings 23 , 24 is constant and remains unchanged during operation of the valve.

In the two switching positions 14 , 15, the Federeinrich device 32 acts with a spring force F on the closure body 13 , the direction of force at an acute angle to the Ver connecting line 25 extends. This results in a resulting closing force that presses the closure body 13 against the associated valve seat 7 , 9 .

To switch between the switching positions 14 , 15 , the actuating device 16 is briefly actuated. In the exemplary embodiment, this comprises a tappet arrangement with two tappets 35 , 36 , which can act on the carrier 18 or preferably on the closure body 13 at high speed in the desired switching direction by means of an actuator 37 .

For example, the plungers 35 , 36 are arranged in such a way that their actuating end 42 of the closing surface 38 , 38 'of the closure body 13 facing the assigned valve seat 7 , 9 in the respective switching position lies opposite the closure body 13 with the smallest possible distance. For this purpose, a respective plunger 35 , 36 can extend through the housing 1 and the associated mouth 6 , 8 as shown. By actuating the actuator 37 , which is preferably arranged on the outside of the valve housing 1 , the tappet 35 , 36 in question is displaced against the closure body 13 - a displaced position is indicated by dash-dotted lines in FIG. 1 at 39 -, the loaded closure body 13 being removed from the associated support section 7 , 9 is lifted and accelerated in the switching direction 17 to the support section. In this case, the compression spring device 33 , which is preferably articulated on the closure body 13 and on the bearing point 24 , is compressed while reducing its overall length, the minimum Längenab dimensions then set when the carrier 18 deflected in this way reaches a dead center at which it lies on the connecting line 25 . However, this is an extremely unstable equilibrium. In practice, it is therefore the case that the closure body accelerated by the plunger 35 , 36 swings over 13 due to the kinetic energy or momentum obtained via the dead center and then immediately from the correspondingly deflected compression spring device 33 in the direction of the desired other switching position is pressed. It is therefore not necessary that the stroke of the tappet 35 , 36 in question corresponds to the entire switching path of the closure body 13 , it may even be less than the path to the connecting line 25 . The only requirement is that the closure body 13 holds sufficient kinetic energy. In this connection, the closure body 13 is preferably designed in such a way that it acts as an inertial body, the inert mass of which supports the process. Alternatively, a separate inertial body could also be provided on the carrier 18 .

The actuators 37 can, for example, be magnetic coils which act on a displaceable armature which is connected to the relevant plunger 35 , 36 or this bil det. However, other suitable actuators could also be used.

In the embodiment shown in FIG. 2 is formed, the carrier 18 completely as a spring device 32 '. In her hand it is, for example, a spiral spring device 43 designed in the manner of a leaf spring, which device 20 is elastically flexible transversely to the longitudinal direction. The entire length of the carrier 18 is taken up by this spiral spring device 43 .

While a bearing point 24 is arranged stationary on the valve housing 1, the other also supported on the valve housing 1 bearing device 24 as required relative to the Ven tilgehäuse 1 movable. It sits on an exemplary stan gene or plunger-like actuator 44 of an actuator 37 'of the actuating device 16 ' and is displaceable by moving the actuator 44 transversely to the switching direction 17 in the longitudinal direction of the connecting line 25 . As a result, the distance between the bearing points 23 , 24 can be varied.

In the two switch positions 14 , 15 there is a minimum distance between the bearings 23 , 24 . Since the length of the carrier 18 is greater than this distance, the carrier takes the bulged shape shown in FIG. 2.

To switch the closure body 13 , the movable La gerstelle 24 is moved by actuating the actuator 37 'in the sense of an increase from the other bearing 24 away. The attached to the movable bearing 24 suspension part 22 is pulled, so that the curvature of the carrier 18 is reduced, the closure body 13 from the support part 9 lifts off. At 45 , a corresponding intermediate position of the carrier 18 is indicated by dash-dotted lines.

The suspension section 22 can be withdrawn until the distance between the bearing points 23 , 24 corresponds to the length of the carrier 18 in the stretched linear state. Here, the carrier 18 takes the neutral position at 46 'indicated by dash-dotted lines, in which it runs along the connecting line 25 . The position taken up by the movable bearing 24 is indicated at 47 .

The carrier 18 is preferably designed so that the neutral position 46 is the position it occupies in the unloaded state. In order to achieve the two switch positions 14 , 15 , therefore, an actuator force directed towards the opposite bearing point 23 must be exerted on the associated suspension part 22 via the actuator 37 ', so that the distance between the bearing points 23 , 24 is reduced and the carrier 18th is forced into the arched shape. However, this has the advantage that no switching force is required to initiate the switching process. It suffices to remove the actuating or holding force of the actuator 37 ', so that the closing body 13 moves solely in the switching direction 17 due to the inherent elasticity of the carrier 18 . Here again it is advantageous that, due to the kinetic energy present, the closure body 13 does not stop when the neutral position 46 is reached , but instead swings beyond the linear shape of the carrier 18 or the neutral position. If the actuator 37 'is immediately moved again in the sense of a reduction in the distance between the bearing points 23 , 24 , the breech body is forced by 13 into the other switching position.

To switch over, the axial preload of the elastically bulging carrier is released for exactly the period of time that it needs to reach the neutral position. Part of it is that only one actuator 37 'is required, for example in turn an electromagnet or a miniaturized linear drive in particular.

It would also be conceivable to at least partially design the carrier 18 as a spring device, which is composed of different spring types. One could imagine, in the construction according to FIG. 1, to provide a spiral spring arrangement similar to the type described in FIG. 2 instead of the rigid support section 27 .

In all of the exemplary embodiments there is a valve with a bistable switching mechanism before, depending on the design very low switching forces and / or very low holding forces are needed.

Claims (15)

1. Valve, with a in a valve housing ( 1 ) arranged closure body ( 13 ) which can be switched between two switching positions ( 14 , 15 ), in which it rests on a housing-fixed support section ( 7 ', 9 '), the closure body ( 13 ) on an elongated support ( 18 ) is provided, the suspension part ( 21 ) arranged on a housing-side bearing ( 23 ) ge over a longitudinally spaced to the closure body ( 13 ) and for switching the closure body ( 13 ) transversely to it Longitudinal direction ( 20 ) can be deflected, with a spring element ( 32 , 32 ') acting on the closure body ( 13 ) and prestressing in at least one switch position ( 14 , 15 ) and with an actuating device ( 16 , 16 ') for deflecting the carrier ( 18 ) for the tick of switching the United closure body ( 13 ), characterized in that the carrier ( 18 ) has two suspension parts ( 21 , 22 ), the are located with respect to the longitudinal direction ( 20 ) of the carrier ( 18 ) at a distance from the sides of the closure body ( 13 ) and via which the carrier ( 18 ) at two opposite to each other transversely to the switching direction ( 17 ) of the closure body ( 13 ) housing-side bearing points ( 23 , 24 ) is suspended, that at least a longitudinal section of the carrier ( 18 ) is formed by the spring device ( 32 , 32 '), and that the distance between the housing-side bearing points ( 23 , 24 ) is selected so that the carrier ( 18 ) in the two switching positions ( 14 , 15 ) of the closure body pers ( 13 ) with respect to the connecting line ( 25 ) between the bearing points ( 23 , 24 ) in the switching direction ( 17 ) to the associated support section ( 7 ', 9 ' ) bulges out or bent Ge takes shape, which is stabilized by the spring means ( 32 , 32 '). 2. Valve according to claim 1, characterized in that only a part of the carrier ( 18 ) of the spring device ( 32 ) is gebil det. 3. Valve according to claim 2, characterized in that the spring device ( 32 ) in the on one side of the United circuit body ( 13 ) located length section of the carrier ( 18 ). 4. Valve according to claim 2 or 3, characterized in that the spring device ( 32 ) is a compression spring device ( 33 ) which is arranged such that its main suspension direction ( 34 ) extends in the longitudinal direction ( 20 ) of the carrier ( 18 ). 5. Valve according to claim 4, characterized in that the compression spring device ( 33 ) is a coil spring device. 6. Valve according to one of claims 3 to 5, characterized in that the on the of the spring means ( 32 ) opposite side of the closure body ( 13 ) located Längenab section of the carrier ( 18 ) on the associated bearing point ( 23 ) pivotally articulated rigid support section ( 27 ). 7. Valve according to one of claims 2 to 6, characterized in that the distance between the bearing points ( 23 , 24 ) is invariable. 8. Valve according to claim 1, characterized in that the carrier ( 18 ) is formed overall by a spring device ( 32 '). 9. Valve according to claim 8, characterized in that the carrier ( 18 ) is partially formed by a compression spring device ( 33 ) GE, which is arranged such that its main suspension direction ( 34 ) in the longitudinal direction ( 20 ) of the carrier ( 18 ) . 10. Valve according to claim 8 or 9, characterized in that the carrier is at least partially formed by a leaf spring-like, transverse to the longitudinal direction ( 20 ) of the carrier ( 18 ) flexurally elastic spiral spring device ( 43 ). 11. Valve according to one of claims 8 to 10, characterized in that the carrier is formed overall by a leaf spring-like spiral spring device ( 43 ). 12. Valve according to one of claims 1 to 11, characterized in that on the carrier ( 18 ), in particular from the closure body ( 13 ) formed, support the switching process of the inertial body is arranged. 13. Valve according to one of claims 1 to 12, characterized in that the actuating device ( 16 ) has a plunger arrangement ( 35 , 36 ), which in particular act on the closure body ( 13 ) or the carrier ( 18 ) to switch over can. 14. Valve according to one of claims 1 to 12, characterized in that the actuating device ( 16 ') has a housing-side fixed actuator ( 37 '), which has a bearing ( 24 ) having an actuator ( 44 ) which Transversely to the switching direction ( 17 ) is displaceable in order to change the distance between the two bearing points ( 23 , 24 ). 15. Valve according to one of claims 1 to 14, characterized in that at least one and preferably both support portions ( 7 ', 9 ') of a fluid channel ( 3 , 4 ) associated valve seat ( 7 , 9 ) are formed.