DEVICE FOR CONTROLLING A FLOW RATE AND EXPANDING A FLUID IN A FLUID CIRCUIT

Abstract

A device for controlling a flow rate and expanding a refrigerant in a refrigerant circuit of an air conditioning system of a motor vehicle. The device has a housing, an actuating element and a valve element arranged in the interior of the housing and aligned in an axial direction, a valve seat element, and at least one sealing element. The valve element is arranged within the valve seat element and sealed towards the housing and the valve seat element via the at least one sealing element, and is formed in a circular cylindrical shape with a sealing area formed on a lateral surface. The inner surface of the sealing element forms a sealing seat in conjunction with the sealing area of the valve element.

Claims

1. A device for controlling a flow rate and expanding a fluid in a fluid circuit, the device comprising: a housing; an actuating element and a valve element arranged in an interior of the housing and aligned in an axial direction; a valve seat element; and at least one sealing element, wherein the valve element is arranged within the valve seat element and sealed towards the housing as well as the valve seat element via the at least one sealing element, and has a substantially circular cylindrical shape with a sealing area formed on a lateral surface, wherein the sealing element has a shape of a circular ring disk with an inner surface formed on an inner diameter as well as a first side face and a second side face pointing in the axial direction, and wherein the inner surface of the sealing element forms a sealing seat in conjunction with the sealing area of the valve element.

2. The device according to claim 1, wherein the sealing element has a groove-shaped recess on the first side face oriented in a direction of the valve seat element, and wherein the recess extends from the first side face in the axial direction into the sealing element and the sealing element is formed in a surrounding manner in a circumferential direction.

3. The device according to claim 2, wherein the sealing element is formed with a sealing edge arranged on the first side face and on the inner diameter in a surrounding manner for abutting on the sealing area of the valve element.

4. The device according to claim 3, wherein the sealing edge has a shape of a web formed between the inner surface and the recess of the sealing element, and wherein the web is elastically deformable.

5. The device according to claim 4, wherein the sealing element has a surrounding edge formed projecting in a surrounding manner from the first side face for abutting on the valve seat element, and wherein the edge delimits the recess on an outside in a radial direction.

6. The device according to claim 1, wherein the valve element is arranged, in a closed state of the device, with the sealing area abutting on the sealing element, and that the valve element, in an open state of the device, is arranged forming a full-circumferential gap between the valve element and the sealing element.

7. The device according to claim 1, wherein there are at least two sealing elements and the valve element is arranged sealed towards the housing as well as the valve seat element via the at least two sealing elements, wherein the valve element is arranged sealed towards the housing as well as the valve seat element via a first one of the at least two sealing elements and towards the housing via a second one of the at least two sealing elements.

8. The device according to claim 7, wherein the valve element, in a closed state of the device, is arranged with the sealing area abutting on the first one of the at least two sealing elements and on the second one of the at least two sealing elements, and that the valve element, in an open state of the device, is arranged with the sealing area abutting on the second one of the at least two sealing elements and at a distance from the first one of the at least two sealing elements.

9. The device according to claim 7, wherein the second one of the at least two sealing elements is formed as a sliding seal.

10. The device according to claim 1, wherein the actuating element is formed as a drive shaft oriented in the axial direction.

11. The device according to claim 10, wherein the drive shaft is formed connected to an electric motor.

12. The device according to claim 10, wherein the drive shaft as well as a transmission arrangement and a sliding anti-rotation lock arrangement are formed for transmitting a rotary movement of the drive shaft about a longitudinal axis into a linear movement of the valve element in the direction of the longitudinal axis relative to the housing.

13. The device according to claim 12, wherein the transmission arrangement is formed as a pair of threads between the drive shaft and the valve element, wherein the drive shaft is arranged inserting into a hole of the valve element formed as a through-hole.

14. The device according to claim 13, wherein an external thread is formed on an outer side of the drive shaft and an internal thread is formed within the hole of the valve element.

15. The device according to claim 13, wherein the transmission arrangement is formed with a free cross section between the drive shaft and the valve element.

16. The use of the device for controlling the flow rate and expanding the fluid according to claim 1 in a refrigerant circuit of an air conditioning system of a motor vehicle.

Description

DRAWINGS

[0036] Further details, features and advantages of configurations of the invention emerge from the following description of an exemplary embodiment with reference to the associated drawings.

[0037] FIG. 1A: shows a device for controlling a flow rate and expanding a fluid in a fluid circuit, in particular a refrigerant circuit of an air conditioning system of a motor vehicle, with a housing and a valve element arranged within the housing in the closed state, in a lateral sectional view,

[0038] FIG. 1B: shows a detail view of an arrangement of a valve element within a valve seat element and two sealing elements of the device from FIG. 1A, in a lateral sectional view,

[0039] FIG. 2A: shows a detail view of the arrangement of the valve element within the valve seat element and two sealing elements of the device from FIGS. 1A and 1B, in a lateral sectional view, and

[0040] FIG. 2B: shows a detail view of the arrangement of the valve element according to FIG. 2A within a first sealing element, in a lateral sectional view.

DETAILED DESCRIPTION OF EMBODIMENTS

[0041] FIG. 1A shows a device 1 for controlling a flow rate and expanding a fluid in a fluid circuit, in particular in a refrigerant circuit of an air conditioning system of a motor vehicle, with a housing 2 and a valve element 6 arranged inside the housing 2 in the closed state, in a lateral sectional view, while FIG. 1B depicts a detail view of the arrangement of the valve element 6 within a valve seat element 7 and two sealing elements 11, 12 of the device 1 according to FIG. 1A, in a lateral sectional view.

[0042] The device 1, in particular an electrically driven valve 1, is formed with an electric motor 3 which sets a drive shaft provided as an actuating element 4 in a rotary movement 4a. With the aid of a transmission arrangement 5 provided on the drive shaft 4 oriented in an axial direction, in particular a thread, specifically a so-called movement thread, the rotary movement 4a of the drive shaft 4 about its longitudinal axis is converted into a translatory stroke movement of a valve element 6, preferably formed as a valve needle. The translatory stroke movement thus corresponds to a linear movement 6a of the valve element 6 in the axial direction, that is to say in the direction of the longitudinal axis of the drive shaft 4.

[0043] The pair of threads of the transmission arrangement 5 is provided between the drive shaft 4 and the valve element 6. Here, the drive shaft 4, which substantially has the shape of a cylinder rod, in particular a round rod with sections of different diameters, is inserted with a free end into a hole 6b formed in the valve element 6. The free end of the drive shaft 4 is arranged distally to an end connected to the electric motor 3. The drive shaft 4 thus has an external thread at the free end as the first element of the pair of threads, while inside the hole 6b of the valve element 6 an internal thread is formed as the second element of the pair of threads.

[0044] The valve element 6 is arranged in a valve seat element 7. The valve element 6, which is moved linearly in the axial direction and substantially extends in the axial direction, is held here by a sliding anti-rotation lock arrangement 8, which prevents a rotary movement of the valve element 6 about the axial direction or the longitudinal axis of the valve element 6 and allows the linear movement 6a in the axial direction.

[0045] The valve element 6 has protrusions 6c in the region sliding along inside the housing 2. The protrusions 6c are formed on an end of the valve element 6 that is oriented towards the electric motor 3 and project in pairs opposite from the valve element 6. The valve element 6 thus has a T-shape in a cross section through the longitudinal axis.

[0046] The housing 2 is formed in the area of the protrusions 6c of the valve element 6 with notch-shaped or groove-like recesses arranged opposite one another with respect to the longitudinal axis of the valve element 6, each of which corresponds in shape to a protrusion 6c of the valve element 6. The shapes of the recesses of the housing 2 correspond to the outer shape of the protrusions 6c of the valve element 6 plus a play for sliding movement of the valve element 6 within the housing 2 in the axial direction.

[0047] By arranging the protrusions 6c of the cross-sectionally T-shaped valve element 6 within the notch-shaped or groove-like recesses of the housing 2, a rotary movement of the valve element 6, driven by the actuating element 4 rotating about the longitudinal axis, is prevented. The valve element 6 is thus guided in the linear movement 6a by the rotary movement 4a of the actuating element 4 without its own rotation about the longitudinal axis.

[0048] The device 1 is also formed with a first connection 9 and a second connection 10 for connecting to fluid lines. A through hole 9a of the first connection is oriented to the valve element 6 in the radial direction, while a through hole 10a of the second connection 10 is oriented in the axial direction of the valve element 6. The through hole 9a of the first connection 9 is pressurized by refrigerant at a first pressure p1, so that the pressure p1 acts on the valve element 6 substantially in the radial direction. The through hole 10a of the second connection 10 is pressurized by refrigerant at a second pressure p2, so that the pressure p2 acts on the valve element 6 substantially in the axial direction. All the pressurized surfaces of the valve element 6 are designed in such a way that the valve element 6 is arranged in an almost isostatic state. The pressure forces acting on the valve element 6 are in equilibrium.

[0049] The introduction of a section formed as a flattened area, not shown, of the thread of the actuating element 4, which otherwise has a circular cross-section, ensures the pressure equalization in the axial direction with respect to the second pressure p2 within the valve 1 as a flow through hole in combination with the hole 6b of the valve element 6 formed as a through bore.

[0050] The valve element 6 is also arranged via two sealing elements 11, 12, in particular a first, static sealing element 11, sealed towards the housing 2 as well as the valve seat element 7, and on the other hand a second, dynamic sealing element 12 sealed towards the housing 2. The second sealing element 12 is formed as a sliding seal, in particular a rod seal, in the form of an axial seal or a ring seal, while the first sealing element 11 is formed as a seat seal, in particular as a valve seat seal. The first sealing element 11 is consequently arranged between the housing 2, the valve element 6 and the valve seat element 7.

[0051] Due to the dimensioning of the electric drive, only a limited force is available for moving the valve element 6, that is to say the valve needle. In addition, a tight fit of the valve element 6 within the valve seat element 7 in the de-energized state of the electric motor 3 as well as at temperatures from −40° C. to +120° C., in particular up to +160° C., must be ensured. By generating a force acting on the valve element 6 and thus pressing the valve element 6 into the valve seat element 7, the valve element 6 can be held by the transmission arrangement 5 formed as a self-locking movement thread. However, a combination of the force pressing the valve element 6 into the valve seat element 7 with a change in temperature and the associated different expansion of the components of the valve 1 result in the components jamming, in particular the valve element 6 within the first sealing element 11, so that the valve element 6 is immovably fixed specifically when attempting to open it from a closed position.

[0052] FIG. 2A shows a detail view of an arrangement of the valve member 6 within the valve seat element 7 and two sealing elements 11, 12 of the device 1 according to FIGS. 1A and 1B, in a lateral sectional view, while FIG. 2B depicts a detail view of the arrangement of the valve element 6 according to FIG. 2A within a first sealing element 11 of the valve 1, in a lateral sectional view.

[0053] The valve element 6 and the first sealing element 11 abut on one another in a sealing area 13, causing the device 1 to be sealed internally. The first sealing element 11 is configured substantially as a circular ring disk with an inner diameter, an outer diameter and an extension in the axial direction, also referred to as the thickness or depth of the first sealing element 11. The lateral surface of the first sealing element 11, which is formed as a hollow circular cylindrical inner surface on the inner diameter, represents a sealing seat 14 in conjunction with a circular cylindrical outer surface or lateral surface of the valve element 6.

[0054] To achieve complete internal tightness of the device 1, at least in the sealing area 13, the valve element 6 must be formed with an exact circular cylindrical outer surface and the first sealing element 11 with an exact hollow circular cylindrical inner surface, which correspond to one another. The production of a circular cylindrical outer surface of the valve element 6 as well as a hollow circular cylindrical inner surface of the first sealing element 11 each with a constant radius over the circumference and the entire length of the sealing area 13 or the sealing seat 14 cannot be ensured due to possible, economically sensible production processes and machining processes.

[0055] In order to compensate for deviations in the radii of the circular cylindrical outer surface of the valve element 6 as well as of the hollow circular cylindrical inner surface of the first sealing element 11 from the constant radius over the circumference and the entire length of the sealing area 13 or the sealing seat 14, the first sealing element 11 is formed with a recess 15.

[0056] The recess 15 has the shape of a groove or a notch, which, from a first side face of the substantially circular ring disk-shaped sealing element 11 pointing in the axial direction, extends into the sealing element 11 in the axial direction, and which surrounds the first sealing element 11 radially. The first side face is oriented in the direction of the valve seat element 7.

[0057] The sealing element 11 is provided with a further recess on a second side face opposite the first side in the axial direction, which recess extends in the form of a groove into the sealing element 11 in the axial direction and surrounds the first sealing element 11 radially. The second side face is oriented in the direction of the housing 2.

[0058] A surrounding edge of the recess 15 arranged on the outside in the radial direction projects from the first side face of the first sealing element 11 pointing in the axial direction so that the first sealing element 11 abuts on the valve seat element 7. The first sealing element 11 abuts on the valve seat element 7 with an outer side pointing in the radial direction of the surrounding edge of the recess 15 arranged on the outside, as well as the area of the first side face of the first sealing element 11 that adjoins from the surrounding edge arranged on the outside in the radial direction to the outside.

[0059] A surrounding edge of the recess 15 arranged on the inside in the radial direction is formed as a flexible sealing edge 16 for abutment of the first sealing element 11 on the valve element 6. The sealing edge 16 has the shape of a web provided between the hollow circular cylindrical inner surface and the recess 15 of the first sealing element 11, which web is elastically deformable, in particular in the radial direction.

[0060] With the elastic deformability of the sealing edge 16 of the first sealing element 11, the sealing seat 14 can be molded onto the circular cylindrical outer surface of the valve element 6. The recess 15 consequently enables an elastic movement of the sealing edge 16 and thus an adaptation of the sealing seat 14 of the first sealing element 11 to the sealing area 13 of the valve element 6, so that the contour of the outer surface of the valve element 6 always abuts on the first sealing element 11, internally sealing the device 1. The adaptation of the sealing surfaces in the sealing area 13 of the valve element 6 or the sealing seat 14 of the first sealing element 11 enables an internally tightly closing valve 1.

[0061] The sealing seat 14 formed in this way with the flexibly deformable sealing edge 16 of the first sealing element 11 serves not only to compensate for geometric deviations in the sealing surfaces but also to compensate for different thermal expansions of the materials of the components of the device 1, in particular the housing 2, the valve element 6 and the valve seat element 7 and the first sealing element 11, without the use of additional elements, such as a spring element.

[0062] The different thermal expansions of the materials of the housing 2, the valve element 6 and the valve seat element 7 as well as the first sealing element 11 have a very clear effect, for example, when the device 1 is closed after operation. In this case, the components can be heated to temperatures in the range up to 160° C.

[0063] After a standstill or a resting phase of the system, the components of the device 1 can have cooled down to an ambient temperature of approximately 25° C. In this case, the first sealing element 11 at the sealing seat 14 in the sealing area 13 can be shrunk onto the valve element 6 so that the device 1 cannot be opened at the next system start.

[0064] With the formation of the first sealing element 11 with the flexible sealing seat 14, the rigid shrinking of the sealing element 11 onto the valve element 6 is avoided, since the flexibly deformable sealing edge 16 compensates for the different thermal expansion of the materials. The valve 1 remains fully functional under all circumstances.

LIST OF REFERENCE NUMERALS

[0065] 1 device, valve [0066] 2 housing [0067] 3 electric motor [0068] 4 actuating element, drive shaft [0069] 4a rotary movement of actuating element 4 [0070] 5 transmission arrangement [0071] 6 valve element [0072] 6a linear movement of valve element 6 [0073] 6b hole of valve element 6 [0074] 6c protrusion of valve element 6 [0075] 7 valve seat element [0076] 8 sliding anti-rotation lock arrangement [0077] 9 first connection [0078] 9a through hole of the first connection 9 [0079] 10 second connection [0080] 10a through hole of the second connection 10 [0081] 11 first sealing element [0082] 12 second sealing element [0083] 13 sealing area [0084] 14 sealing seat [0085] 15 recess [0086] 16 sealing edge [0087] p1, p2 pressure