VALVE

Abstract

Valve for blocking and releasing a flow path, having an electromagnetic actuator unit, an armature movable by the electromagnetic actuator unit, and a closure element connected to the armature. The closure element blocks and releases a flow path. A housing receives the armature and a first axial end of the closure element, a housing part forms a valve seat and against which a second axial end of the closure element is pressed by a spring device in a closed position of the valve. The spring device has at least one spring compressible at a first spring rate starting from a fully closed position of the valve to a partially open intermediate position of the valve, and a spring compressible at a second spring rate starting from a partially open intermediate position of the valve to a fully open position of the valve.

Claims

1.-9. (canceled)

10. A valve for blocking and releasing a flow path, comprising: an electromagnetic actuator unit; an armature configured to be moved axially by the electromagnetic actuator unit; a closure element connected to the armature and configured to block and release a flow path; a housing that receives at least the armature and a first axial end of the closure element connected to the armature; a spring device comprising: at least one first spring that can be compressed at a first spring rate starting from a fully closed position of the valve up to a partially open intermediate position of the valve; and a second spring that can be compressed at a second spring rate starting from a partially open intermediate position of the valve up to a fully open position of the valve, wherein the first spring rate differs from the second spring rate; and a housing part that forms a valve seat and against which a second axial end of the closure element is pressed by a spring device in a closed position of the valve.

11. The valve as claimed in claim 10, wherein the second spring rate is greater than the first spring rate.

12. The valve as claimed in claim 10, wherein the spring device has at least the at least one first spring which is compressible at the first spring rate, and the second spring which is compressible at the second spring rate.

13. The valve as claimed in claim 12, wherein the at least one first spring and the second spring are arranged coaxially.

14. The valve as claimed in claim 13, wherein the second spring has a smaller diameter than the at least one first spring.

15. The valve as claimed in claim 14, wherein the at least one first spring is supported on a base of the closure element and the second spring is supported on a collar inside the at least one first spring and concentric thereto, and a stop is arranged on the base of the closure element and is in contact with the collar during compression of the second spring.

16. The valve as claimed in claim 10, wherein the spring device comprises a single spring which can be compressed at the first spring rate up to an intermediate position of the closure element and then at the second spring rate, wherein the first spring rate is smaller than the second spring rate.

17. The valve as claimed in claim 10, wherein the electromagnetic actuator unit is configured to exert either a first force F.sub.1 or a second force F.sub.2 on the armature, wherein F.sub.1 is not equal to F.sub.2.

18. A motor vehicle comprising: a turbocharger device comprising: an intake side with a compressor; and a turbine side with a turbine; a bypass line to the compressor is provided on the intake side; a valve is arranged in the bypass line configured to release or block the bypass line comprising: an electromagnetic actuator unit; an armature configured to be moved axially by the electromagnetic actuator unit; a closure element connected to the armature and configured to block and release a flow path; a housing that receives at least the armature and a first axial end of the closure element connected to the armature; a spring device comprising: at least one first spring that can be compressed at a first spring rate starting from a fully closed position of the valve up to a partially open intermediate position of the valve; and a second spring that can be compressed at a second spring rate starting from a partially open intermediate position of the valve up to a fully open position of the valve, wherein the first spring rate differs from the second spring rate; and a housing part that forms a valve seat and against which a second axial end of the closure element is pressed by a spring device in a closed position of the valve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Embodiments of the invention will now be explained in greater detail with reference to the accompanying figures.

[0029] FIG. 1 is diagrammatically, in longitudinal section, a valve in a closed position;

[0030] FIG. 2 is the valve from FIG. 1 in a partially open intermediate position; and

[0031] FIG. 3 is diagrammatically the valve from FIG. 1 in a fully open position.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

[0032] FIG. 1 shows a valve 1, configured as a recirculation dump valve for a turbocharger (not shown) of a vehicle, according to one aspect of the invention, in a closed position. The valve 1 is shown in FIG. 1, as in all figures, in longitudinal section, i.e. cut parallel to a longitudinal axis of the valve.

[0033] The valve 1 comprises a housing 2 with an integrally formed flange having bores, via which the housing 2 is flanged-mounted on the turbocharger (not shown) in a region of a bypass line 4. In the installed position shown, the housing 2 is adjoined by a second housing part 13 of the valve 1.

[0034] Alternatively, the housing part 13 and the further housing part 18 may be formed integrally with the housing 2.

[0035] An electromagnetic actuator unit 5 having a coil 6 and a metal pin 7 connected to an armature 8 is arranged in the housing 2. The pin 7 is mounted by means of an upper bearing 24 and a lower bearing 26 so as to be axially displaceable in the housing 2, and is fixedly connected to a pot-like closure element 10.

[0036] The pot-like closure element 10, serving as a piston, cooperates with a valve seat 12 to block or release the bypass line 4. For this, the closure element 10 has an annular sealing face 14, which cooperates with a valve seat 16 to close off the cross-section of the bypass line 4. A spring device 17 presses the closure element 10 in the direction of the valve seat 16. When the valve 1 is not actuated, the force generated by the spring device 17 is countered only by the force acting on the base 12 of the closure element 10 owing to the pressure in the line 4.

[0037] The closure element 10 is sealed against the housing part 42 by an annular seal 38 with V-shaped profile.

[0038] In the embodiment shown, the spring device 17 has a first spring 32 and a second spring 34. The first spring 32 and the second spring 34 are arranged coaxially to the longitudinal axis L of the valve 1 and configured as coil springs, wherein the second spring 34 has a smaller diameter than the first spring 32 and is arranged inside the first spring 32. The first spring 32 and the second spring 34 have spring rates D1 and D2 respectively.

[0039] The second spring 34 is formed shorter than the first spring 32. The first spring 32 is supported at one end on the base 12 of the closure element 10 and the other end on a ring disc 40, which is arranged in the housing 2 coaxially to the longitudinal axis L. The second spring 34 is also supported at one end on the ring disc 40, but at its other end on a collar 30 held by a guide sleeve 28.

[0040] The guide sleeve 28 is arranged so as to be axially displaceable in the housing 2, concentrically to the pin 7 and armature 8. The guide sleeve 28 is also arranged so as to be axially displaceable relative to the pin 7 and armature 8. Its purpose is to hold the lower bearing 26 and also support the collar 30.

[0041] A stop 36, in the form of a partially interrupted, radially peripheral web, is arranged on the base 12 of the closing element 10 coaxially to the longitudinal axis L. The distance from the stop 36 to the longitudinal axis L substantially corresponds to the distance of the collar 30 from the longitudinal axis L, so that by displacement of the closure element 10 in the axial direction, the stop 36 can be brought into contact with the collar 30.

[0042] The two springs 32, 34 together form the spring device 17. The spring device 17 has two different spring rates in the embodiment shown. When the spring device 17 is compressed, starting from the closed position of the valve 1 shown in FIG. 1, the spring rate D1 of the first spring 32 is active because initially only this spring 32 is compressed. If the valve 1 is opened further however, beyond a defined intermediate position, at the same time also the second spring 34 is compressed, so that in total the spring constants D1+D2 are applied. This process is now described in more detail on the basis of FIGS. 2 and 3.

[0043] FIG. 2 shows the valve 1 from FIG. 1 in a partially open position in which the bypass line 4 is partially released, i.e. a reduced mass flow through this is possible. In order to reach the partially open position, a voltage was applied to the magnetic coil 6, which resulted in a magnetic force that was sufficient to compress the first spring 32. Then the valve 1 opened until the stop 36 came to rest on the underside of the collar 30. This position is illustrated in FIG. 2.

[0044] In this position however the axial movement of the closure element 10 stops, since for further opening of the valve 1, not only must the counter-force of the first spring 32 be overcome, but also the further counter-force of the second spring 34, which is now connected in parallel. Because of the contact between the stop 36 and the collar 30, for further opening of the valve, both springs 32, 34 must now be compressed, for which a greater magnetic force is required.

[0045] If the bypass line 4 is to be only partially opened, therefore a voltage is applied to the coil 6, which is sufficient to overcome the counter-force of the first spring 32 and reach the intermediate position shown in FIG. 2, but which is too small to overcome the additional counter-force of the second spring 34 and reach the fully open position shown in FIG. 3.

[0046] In order to reach the fully open position of the valve 1 shown in FIG. 3, starting from the intermediate position shown in FIG. 2, then a higher magnetic force is provided by the actuator unit 5. For this, for example, a higher voltage is applied. If the force is sufficient to overcome the counter-force provided by the two springs 32, 34, which are now connected in parallel, the closure element 10 moves in the axial direction until it completely releases the bypass line 4. This position of the valve 1 is illustrated in FIG. 3.

[0047] The valve 1 thus allows not only a fully closed and a fully open position, but also an intermediate position. If the spring device 17 is configured to have more than two different spring constants, further intermediate positions are also conceivable, between which typically the spring constant rises in steps.

[0048] The electromagnetic actuator unit 5 is actuated accordingly to overcome the respective counter-force of the spring device 17. In this way, by an electromagnetic valve and while omitting position sensors, it is possible to provide a recirculation dump valve which has one or more defined intermediate positions of the closure element 10, which can be actuated in targeted fashion.

[0049] Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.