DE102006056842A1 - Injection valve for medium e.g. petrol, in vehicle, has flexible sealing unit staying in connection with fluid in hollow chamber with its inner side, sealing at valve seat with its outer side or releasing passage opening of valve body - Google Patents

Abstract

The valve (1) has an actuator (4) arranged in an inner hollow space (3c) of a stationary valve unit i.e. valve needle (3), where the fluid (5) is arranged within the inner hollow space. A flexible sealing unit (6) is arranged at the valve unit. The sealing unit stays in connection with the fluid with its inner side. The sealing unit seals at a valve seat (2b) of a valve body (2) with its outer side or releases a passage opening (2a) of the valve body. The sealing unit exhibits a cap-shape, where the sealing unit is fixed to an end of the valve unit.

Description

State of the art

The The present invention relates to a valve for injecting a Medium, in particular a valve for the injection of liquid or gaseous Fuel.

valves for the injection of media are different from the prior art Embodiments known. Most recently However, both gasoline and diesel injection have a lot of time reinforced high pressures required, under which the medium is to be injected. This elevated in particular the requirements for the injection valves. In particular to ensure the tightness of the valve if no injection is to be made, the individual components of the valves are manufactured with the highest precision. This However, it is relatively expensive and expensive. In particular for production Consumption and emissions, however, will increasingly increase in the near future used smaller engines and thus cheaper vehicles.

Advantages of the invention

The inventive valve for injection of a medium having the features of the claim 1 shows in contrast the advantage that it can be produced relatively inexpensively and still at high pressures can be used and has the required tightness. The valve according to the invention here has a minimum number of moving parts to special economical to be manufactured. This is inventively achieved in that the valve a valve body with a passage opening and a valve seat and a fixed valve element has. The valve element has a cavity in which an actuator and a liquid is arranged. The cavity is to the outside by a flexible and sealed high-strength sealing element, wherein an inside of the Sealing element with the liquid, which is in the cavity, is in communication. An outside of the sealing element seals on the valve seat of the valve body and gives the passage opening for the medium to be injected free or closes this. By use the flexible and high-strength sealing element can be ensured that the valve is also for use with very high pressures, such as fuel injection of liquid fuels or an injection of gaseous Fuels under pressure is suitable. Thus, according to the invention Valves very cost-effective to be provided. The flexible, high-strength sealing element can while an excellent seal by a certain elasticity of the sealing element to ensure. About that In addition, the valve according to the invention a very small space, in particular also designs possible are, where the valve body a big Length and may have a small diameter, which was previously in the state of Technique only under extreme difficulties and high costs possible is.

The under claims show preferred developments of the invention.

Preferably the fixed valve element is a valve needle or a slider. This allows in particular existing concepts and designs of valves used be, which in contrast to the prior art far cheaper can be produced and still at higher levels To press can be used.

Further Preferably, the sealing element has a substantially cap-like Mold on and is at one end of a valve element, which serves as a valve needle is formed, fixed. This can on the one hand a very simple Structure similar can be realized by needle valves and on the other hand can the sealing element can be produced very easily.

The Shape of the sealing element is preferably U-shaped in section. Further Preferably, the sealing element has a flat on its inside Area, in particular perpendicular to a longitudinal axis of the valve element on. As a result, in particular a symmetrical pressure on the Sealing element exercised be, so that a uniform deformation the sealing element possible is.

According to one Alternative embodiment of the invention is the shape of the sealing element on average essentially W-shaped. This can in particular a provision of the sealing element after a release of the passage opening by the shape of the sealing element supports become.

According to one Another preferred embodiment of the invention is between the Valve body and the valve element at least one supply area arranged to the supply medium to be injected to the sealing element. Particularly preferred the supply area while channel-like recesses on the inside the valve body and / or on the outside of the valve element. This can be a particularly compact design of the valve can be achieved.

Preferably, the actuator, which is arranged in the cavity of the valve element, a piezoelectric actuator. Piezo actuators are particularly well suited because they are physically small. Alternatively, the actuator operated electromagnetically or mechanically.

According to one another preferred embodiment of the present invention the valve further comprises a flexible membrane, which in the cavity of Valve element is arranged and connected to the actuator. at an operation of the actuator, a shape of the membrane is changed such that the sealing element lifted off the valve seat. The membrane deforms starting from the cavity to the outside. A particularly compact design is achievable when the actuator is arranged between the sealing element and the membrane, so that Seal element and diaphragm face each other.

Further Preferably, a stroke of the actuator can be translated by a translator device become. This allows especially larger forces on the be exercised in the valve element trapped liquid.

The Sealing element is preferably made of a highly elastic metal, in particular of a metallic glass alloy, also bulk metallic Called glass (BMG). Alternatively, the sealing element made of a titanium alloy or a high-strength plastic. The sealing element is preferably attached to the valve element by means of gluing or welding attached.

The inventive valve thus has only a small number of moving parts, so that only a little wear and tear so that virtually no maintenance costs.

drawing

following become preferred embodiments the invention with reference to the accompanying drawings in Detail described. In the drawing is:

1 a schematic sectional view of a valve according to a first embodiment of the invention,

2 a sectional view taken along the line II-II of 1 .

3 a schematic sectional view of a valve according to a second embodiment of the invention,

4 a schematic sectional view of a valve according to a third embodiment of the invention,

5 a sectional view taken along the line VV of 4 .

6a to 6f schematic sectional views of various sealing elements, which can be used in a valve according to the invention, and

7 a schematic sectional view of a valve according to a fourth embodiment of the invention.

Preferred embodiments the invention

The following is with reference to the 1 and 2 a valve 1 described according to a first embodiment of the invention.

As in 1 shown includes the valve 1 a valve body 2 , which at its end a passage opening 2a having. In the drawing, only one passage opening 2a shown, but there are several openings possible. At the valve body 2 is also an annular valve seat 2 B formed, which on an inner side of the valve body 3 is trained. The valve 1 further comprises a non-movable valve needle element 3 which is formed in two parts in this embodiment. The valve needle element 3 includes a first part 3a and a second part 3b , Inside the valve needle element is a closed cavity 3c educated. In the cavity 3c is an actor 4 , which is a piezoelectric actuator in this embodiment, arranged. In the remaining cavity 3c is a liquid 5 arranged.

How out 1 is apparent, is the first part 3a the valve needle element 3 needle-shaped with an inner channel 3d formed, which to the end of the valve needle element 3 is open. The cavity 3c and the channel 3d However, are by a cap-shaped sealing element 6 sealed to the outside. The sealing element 6 is on the valve needle element 3 fixed by gluing or welding or soldering. The sealing element 6 has flexible and high-strength properties and is preferably made of highly elastic parts, such as a titanium alloy (nitinol) or a metallic glass alloy (BMG). How out 1 it can be seen seals the sealing element in the closed state of the valve at the annular valve seat 2 B of the valve body 2 from. How farther 2 is apparent, is on the inside of the valve body 2 a variety of elongated feed channels 2c formed to a medium to be injected to the valve seat 2 B supply.

That in the 1 and 2 illustrated first embodiment is a valve for injection of fuel, wherein the fuel under pressure in the supply channels 2c pending.

1 shows the closed position of the valve 1 , By activation of the piezo actuator 4 is, as indicated by the arrow A, through the piezoelectric actuator 4 a high pressure on the liquid 5 produced, which, as indicated by the arrows B, to a local elastic deformation of the highly elastic sealing element 6 leads. As a result, the sealing element seals 6 safe at the valve seat 2 B from. The seal is so high quality that the medium to be injected can also be at the highest pressures. The piezo actuator is opened to open the valve 4 operated so that it shortens, causing the on the sealing element 6 acting pressure is reduced, so that the sealing element 6 due to its elasticity the valve seat 2 B releases. The material of the sealing element 6 should therefore have only a relatively small modulus of elasticity. This can do so in the feed channels 2c Pending medium through the passage opening 2a in the valve body 2 For example, be injected into a combustion chamber. Should the valve 1 be closed again, the piezoelectric actuator 4 pressed again, so that it lasts again and pressure over the liquid 5 on the sealing element 6 is exercised and the sealing element 6 again at the valve seat 2 B is applied.

According to the invention, the valve 1 In this case, a particularly small number of moving parts, so that it can be produced very inexpensively. Due to the high elasticity of the sealing element 6 can also have a certain area positive fit between the sealing element 6 and the valve seat 2 B be achieved. As a liquid 5 For example, oil or a (viscous) silicone compound is used. For the valve according to the invention can also be realized an already made design of valves, for example valves with a long valve needle element with a small diameter.

The following is with reference to 3 a valve 1 according to a second embodiment of the invention described in detail. Identical or functionally identical parts are denoted by the same reference numerals as in the first embodiment.

In contrast to the first embodiment, the valve 1 the second embodiment additionally a membrane 7 on. The membrane 7 closes the cavity 3c the valve needle element 3 off on one side. The membrane 7 is with the actor 4 connected, which is also a piezoelectric actuator in the embodiment and in the cavity 3c is arranged. 3 again shows the closed state of the valve. By actuating the actuator 4 as indicated by the arrow A, the membrane 7 as shown by the dashed line 7 ' indicated, deformed. This will be the sealing element 6 whose inside with the liquid 5 communicating, from the valve seat 2 B lifted. This results in an injection of the medium through the passage opening 2a in the valve body 2 , To the deformation of the membrane 7 to allow, is in the cavity 3c another gas filled area 3e intended. The membrane 7 is further, as in 3 shown between the first part 3a and the second part 3b of the valve element 3 arranged.

As further out 3 it can be seen that is the cavity 3c directed side of the membrane 7 with the liquid 5 in contact, being in the actuator 4 Through openings 4a are formed. Otherwise, this embodiment corresponds to the first embodiment, so that reference may be made to the description given there.

The following is with reference to the 4 and 5 a valve 1 according to a third embodiment of the invention, wherein identical or functionally identical parts are denoted by the same reference numerals as in the preceding embodiment.

As in 4 shown corresponds to the valve 1 of the third embodiment, substantially the first embodiment, wherein in contrast to the first embodiment additionally still a translator device 8th in the valve needle element 3 is provided. The translator facility 8th translates a hub of the actor 4 provided piezoelectric actuator. This can affect the liquid 5 , which on the interior of the sealing element 6 is applied, a higher pressure to be exercised. Thus, the valve 1 of the third embodiment is suitable for use at higher pressures. Furthermore, the valve needle element is formed only in one piece and the actuator 4 seals by means of a seal 9 at the opposite end of the sealing element 6 from.

Otherwise corresponds to this embodiment the previous embodiments, so that reference can be made to the description given there.

The 6a to 6f show various possibilities of an embodiment of the highly elastic sealing element 6 on average. All shown sealing elements 6 are doing to a central axis XX of the valve 1 formed symmetrically. This in 6a shown sealing element 6 has in section a U-shape and can therefore be provided in a particularly simple and cost-effective. This in 6b shown sealing element 6 has in section a U-shape and also a flat area 6a on. The plane area 6a has the function of even pressure distribution at the extreme end of the sealing element 6 sure. As a result, a particularly uniform seal on the valve seat can be achieved. This in 6c shown sealing element has next to the flat area 6a Furthermore, on its inside a circumferential constriction 6b on. 6d shows a section in the substantially W-shaped configuration of the sealing element 6 , which supports a provision of the sealing element. This in 6e shown sealing element 6 has constrictions directed in the axial direction XX 6c on and a tapered end 6d , As a result, in particular, a surface seal by the sealing element 6 be enabled. This in 6f shown sealing element 6 is similar to the one in 6c shown sealing element, wherein the constriction 6b deeper and the outside part spherical. In principle, it should be noted that the configuration of the outer sealing surface of the sealing element 6 each from the valve seat 2 B on the valve body 2 depends.

7 shows a valve 1 according to a fourth embodiment of the invention, wherein the same or functionally identical parts are designated as in the preceding embodiments.

In contrast to the previous embodiments, the valve 1 of the fourth embodiment in the form of a slide valve, wherein a slide 13 is provided as a valve element. The slider 13 However, it is fixed in a valve body 12 arranged. How out 7 can be seen, the slider 13 two annular projecting portions 13a and 13b on. At the first annular area 13a is a first sealing element 16a and at the second annular area 13b is a second sealing element 16b arranged. In dashed lines 16a ' respectively. 16b ' are the deformations of the sealing elements 16a and 16b in 7 drawn, which represent the sealing state. The first and second sealing element 16a . 16b each seal on valve seats 12b , which are provided annularly, from. In the slide 13 is also a first channel 17a and a second channel 17b intended. Similar to the previous embodiments, the channels 17a . 17b with a first fluid 15a or a second fluid 15b filled. The one end of the channels opens on an inner side of the first sealing element 16a or of the second sealing element 16b and the other end of the channels each terminate at an actuator 14a . 14b , which are also formed in this embodiment as a piezoelectric actuators.

The function of the valve 1 according to the fourth embodiment is similar to that in the previous embodiments. If the first actor 14a or the second actuator 14b is pressed, a pressure on the liquid 15a respectively. 15b exerted, wherein an elastic deformation of the first sealing element 16a or of the second sealing element 16b in the with 16a ' respectively. 16b ' marked positions takes place. In these positions are the passage openings 12a in the valve body 12 locked. As a result, no medium from the passages 12a escape. In the in 7 shown opened state, however, can medium, which on the outside of the sealing elements 16a and 16b flowed past, through the passages 12a emerge and be injected into a room, such as a combustion chamber of an internal combustion engine. The advantage of this designed as a slide valve valve of the fourth embodiment lies in the fact that the passages 12a can be opened or closed individually. However, this is also the construction effort by the provision of two actuators 14a . 14b and two closed volumes of liquid 15a . 15b increased. Otherwise, this embodiment corresponds to the previous embodiment, so that reference can be made to the description given there.

Claims (11)

Valve for injecting a medium, comprising a valve body ( 2 ; 12 ), which at least one passage opening ( 2a ; 12a ) and a valve seat ( 2 B ; 12b ), a fixed valve element ( 3 ; 13 ), which has an internal cavity ( 3c ; 17a . 17b ), an actuator ( 4 ; 14a . 14b ), which in the inner cavity ( 3c ; 17a . 17b ), a liquid ( 5 ; 15a . 15b ), which is arranged in the interior of the cavity, a flexible, high-strength sealing element ( 6 ; 16a ; 16b ), which on the valve element ( 3 ; 13 ) is arranged, with an inside with the liquid in the cavity ( 5 ; 15a . 15b ) and with an outside on the valve seat ( 2 B ; 12b ) of the valve body ( 2 ; 12 ) or the passage opening ( 2a ) releases. Valve according to claim 1, characterized in that the fixed valve element ( 3 ; 13 ) is a fixed valve needle or a fixed slide. Valve according to one of the preceding claims, characterized in that the sealing element ( 6 ) has a substantially cap-like shape and at one end of the fixed valve element ( 3 ; 13 ) is fixed. Valve according to claim 3, characterized in that a shape of the sealing element ( 6 ) is substantially U-shaped in section. Valve according to claim 3 or 4, characterized in that the sealing element ( 6 ) on its inside a flat area ( 6a ), which in particular perpendicular to a longitudinal axis XX of the valve element ( 3 ; 13 ). Valve according to claim 3, characterized in that a shape of the sealing element ( 6 ) is substantially W-shaped in section. Valve after one of the previous times claims, characterized in that the sealing element ( 6 ) is made of a metallic glass alloy or a titanium alloy. Valve according to one of the preceding claims, characterized in that between the valve body ( 2 ) lind the valve element ( 3 ) at least one supply area ( 3e . 30 is arranged to the medium to be injected to the sealing element ( 6 ). Valve according to claim 8, characterized in that the supply area channel-like recesses on the inside of the valve body ( 2 ) and / or channel-like recesses on the outside of the valve element ( 3 ). Valve according to one of the preceding claims, characterized in that the actuator ( 4 ) is a piezoelectric actuator. Valve according to one of the preceding claims, further comprising a flexible membrane ( 7 ), which in the inner cavity ( 3c ) of the valve element ( 3 ) and with the actuator ( 4 ), wherein upon actuation of the actuator ( 4 ) a form of the membrane ( 7 ) is changed such that the sealing element ( 6 ) from the valve seat ( 2 B ) Will get removed.