INJECTION MOLDED PLASTIC VALVE ASSEMBLY FOR A MOTOR VEHICLE

Abstract

A valve assembly for controlling cooling fluid flows in a motor vehicle, the valve assembly including: a valve housing having a main housing body and a housing cover connected to the main housing body, a valve body receiving space being developed in the valve housing, which is enclosed by the main housing body and the housing cover, a fluid line system having at least two fluid lines, which run in different spatial regions starting from the valve body receiving space, a valve body, which is accommodated in the valve body receiving space rotatable about an actuation axis, the valve body being designed to taper along the actuation axis in such a way that by rotating the valve body about the actuation axis, a fluid connection situation of at least two fluid lines of the fluid line system is changeable, and a prestressing means, which applies a pressure onto the valve body along the actuation axis in the tapering direction,
both the valve body as well at least the main housing body to be formed as injection molded parts from thermoplastic.

Claims

1.-15. (canceled)

16. A valve assembly for controlling cooling fluid flows in a motor vehicle, the valve assembly comprising: a valve housing having a main housing body and a housing cover connected to the main housing body, a valve body receiving space being developed in the valve housing, which is enclosed by the main housing body and the housing cover, a fluid line system having at least two fluid lines, which run in different spatial regions starting from the valve body receiving space, a valve body tapering along an actuation axis, which is accommodated in the valve body receiving space rotatable about the actuation axis in such a way that by rotating the valve body about the actuation axis, a fluid connection situation of at least two fluid lines of the fluid line system is changeable, and a prestressing means, which applies a pressure onto the valve body along the actuation axis in a tapering direction, wherein both the valve body as well as at least the main housing body are formed as injection molded parts from thermoplastic.

17. The valve assembly as recited in claim 16, wherein the housing cover is fused to the main housing body.

18. The valve assembly as recited in claim 16, wherein the housing cover is welded to the main housing body.

19. The valve assembly as recited in claim 16, wherein the valve housing comprises only the main housing body and the housing cover as housing components.

20. The valve assembly as recited in claim 16, wherein at least two connection formations are formed on the outer side of the valve housing for connecting a fluid line to the latter.

21. The valve assembly as recited in claim 16, wherein an actuating shaft protrudes from the valve body along the actuation axis, which penetrates through the valve housing.

22. The valve assembly as recited in claim 16, wherein between the valve body and a wall bounding the valve body receiving space, a shell element made of a plastic having a low coefficient of friction is disposed.

23. The valve assembly as recited in claim 22, wherein the plastic that has a low coefficient of friction is taken from the group consisting of polytetrafluoroethylene, ethylene tetrafluoroethylene copolymer, polyoxymethylene, polyphtalamide, polyvinylidene fluoride, a thermoplastic filled with a friction-reducing filler, a thermoplastic filled with friction-reducing graphite and a thermoplastic filled with friction-reducing PTFE.

24. The valve assembly as recited in claim 16, wherein the valve body abuts directly on a wall bounding the valve body receiving space, the valve body being formed from a plastic having a low coefficient of friction.

25. The valve assembly as recited in claim 24, wherein the plastic that has a low coefficient of friction is taken from the group consisting of polytetrafluoroethylene, ethylene tetrafluoroethylene copolymer, polyoxymethylene, polyphtalamide, polyvinylidene fluoride, a thermoplastic filled with a friction-reducing filler, a thermoplastic filled with friction-reducing graphite and a thermoplastic filled with friction-reducing PTFE.

26. The valve assembly as recited in claim 16, wherein the valve body has at least one volume through which fluid is able to flow in the operation of the valve assembly, the valve body having on its outer side at least one rib protruding away from the actuation axis and running on the outer side of the valve body, which in the outer surface of the valve body surrounds the flow-through volume or an opening of the flow-through volume through which fluid is able to flow.

27. The valve assembly as recited in claim 26, wherein the valve body has a plurality of flow-through volumes and/or a plurality of flow-through openings in its outer surface, each flow-through volume and/or each flow-through opening being surrounded by at least one rib protruding on the outer side of the valve body and running along an outer side of the valve body.

28. The valve assembly as recited in claim 16, wherein the prestressing means is supported on the valve housing side with a first support section and on the valve body side with a second support section that is different from the first support section.

29. The valve assembly as recited in claim 28, wherein a sliding bushing is situated between the second support section and the valve body, which is in a sliding contact engagement with the second support section and/or with the valve body.

30. The valve assembly as recited in claim 16, wherein the prestressing means is made of metal.

31. The valve assembly as recited in claim 30, wherein the prestressing means is the only metallic component in the valve housing.

32. The valve assembly as recited in claim 16, wherein the prestressing means is made of a stainless steel.

33. The valve assembly as recited in claim 16, wherein the valve assembly has two valve bodies that are coaxial with respect to the actuation axis, are axially movable relative to each other, and are respectively axially loaded.

34. The valve assembly as recited in claim 33, wherein the two valve bodies are connected to each other for joint rotation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The invention may take physical form in certain parts and arrangement of parts, a preferred embodiment of which will be described in detail and illustrated in the accompanying drawings which forms a part hereof and wherein:

[0035] FIG. 1 a schematic top view in the viewing direction along the actuation axis onto a first exemplary embodiment of a valve assembly according to the invention in the left half of the drawing and onto a second exemplary embodiment of a valve assembly according to the invention in the right half of the drawing,

[0036] FIG. 2 a schematic elevation view of the two valve assemblies of FIG. 1,

[0037] FIG. 3 a schematic sectional view of the two specific embodiments of FIGS. 1 and 2 along the sectional plane III-III of FIG. 1,

[0038] FIG. 4 a schematic perspective view of a first specific embodiment of a valve body for use in one of the valve assemblies of FIGS. 1 through 3,

[0039] FIG. 5 a schematic perspective view of a second specific embodiment of a valve body for use in one of the valve assemblies of FIGS. 1 through 3,

[0040] FIG. 6 a schematic elevation view of a first valve body configuration having two identical valve bodies, and

[0041] FIG. 7 a schematic elevation view of a second valve body configuration having two identical valve bodies.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0042] Referring now to the drawings wherein the showings are for the purpose of illustrating preferred and alternative embodiments of the invention only and not for the purpose of limiting the same, FIGS. 1 through 3 respectively show in the left half of the drawing a first specific embodiment of a valve assembly 10 and in the right half of the drawing a second specific embodiment of a valve assembly 110.

[0043] Components and component sections identical and functionally identical to those in the first specific embodiment are labeled in the second specific embodiment with the same reference numerals, but incremented by the number 100. The second specific embodiment will be described only to the extent that it differs from the first specific embodiment, express reference otherwise being made to the explanation of the first specific embodiment for the description of the second specific embodiment. The separation of the two specific embodiments occurs along a separation plane T that is respectively orthogonal to the drawing planes of FIGS. 1 through 3.

[0044] Valve assembly 10 comprises a valve housing 12, which is mounted in a base 14 in the illustrated exemplary embodiment. Base 14 is not necessary, however.

[0045] Four connection formations 16 protrude from valve housing 12 along connection axes A in the exemplary form of respectively one connection fitting for connecting a fluid line such as a hose or a pipe, for example. In a manner known per se, connection formations 16 respectively have at their free longitudinal end a projecting rim running around connection axis A preferably in a closed manner as a safety catch of a fluid line situated on the respective connection formation 16. Connection formations 16 are part of a fluid line system 17, which also includes the fluid lines 19 (see FIG. 3) developed in valve housing 12.

[0046] The viewer of FIG. 1 looks onto housing cover 18, which completely conceals the main housing body 20 (see FIGS. 2 and 3) situated behind housing cover 18 in the viewing direction of FIG. 1.

[0047] A central opening 22 passes through housing cover 18, through which an actuating shaft end 24 of a valve body 26 (see FIGS. 2 and 3) extends along the actuation axis B, which is orthogonal to the drawing plane of FIG. 1. Actuating shaft end 24 is thus accessible from outside valve housing 12 for introducing a torque using a drive that is now shown.

[0048] FIG. 2 shows an elevation view of the two specific embodiments of valve assemblies 10 and 110, respectively, from FIG. 1. The direction of view of FIG. 2 runs along the lowermost connection axis in FIG. 1, orthogonally to actuation axis B, which runs parallel to the drawing plane of FIG. 2.

[0049] As may be seen in FIG. 2, the two specific embodiments differ, among other things, in that housing cover 18 is fused with main housing body 20, that is, preferably fused by welding. For the preferred integral connection of housing cover 18 and main housing body 20, various welding methods are conceivable such as, for example, hot plate welding, infrared welding, hot air welding, ultrasonic welding and the like. Housing cover 18 may also be integrally connected to main housing body 20 in a chemical manner, for example in that the mutually facing surfaces of housing cover 18 and main housing body 20 are partially dissolved by application of a solvent and are connected to each other in the partially dissolved state. Adhesive bonding of housing cover 18 to main housing body 20 is in principle also conceivable, although thermal fusion of housing cover 18 and main housing body 20 is preferable. Fusing housing cover 18 and main housing body 20 results in an absolutely tight joint between housing cover 18 and main housing body 20, without having to provide a separate sealing configuration between the two components.

[0050] The housing cover 118 of the second specific embodiment of valve assembly 110, on the other hand, is screw fitted to main housing body 120. As may be seen in the sectional view of FIG. 3, this requires, however, the development of a sealing groove 128 in one of the two components of housing cover 18 and main housing body 20, in the illustrated example in housing cover 18. Furthermore, in order to seal the joining gap between housing cover 18 and main housing body 20, which exists even after the screw fitting, a sealing device is required, which is to be situated in sealing groove 128.

[0051] For better clarity, the screw connection between housing cover 118 and main housing body 120 behind the sectional plane is not shown in FIG. 3.

[0052] As is further shown in the sectional view of FIG. 3, whose sectional plane III-III includes both actuation axis B as well as both connection axes A right and left in FIG. 1, the connection formations 116 of the second specific embodiment are developed as separate components and mounted in corresponding mounting recesses, for example adhesively bonded and/or shrunk into these mounting recesses.

[0053] The connection formation 16 of the first specific embodiment by contrast is formed in one piece on the main housing body 20 produced by injection molding. The main housing body 120 of the second specific embodiment is also produced by injection molding.

[0054] As may be seen further in FIG. 3, actuating shaft end 24 is formed in one piece with the roughly schematic frustoconical valve body 26 and protrudes axially from the larger end face of the roughly schematic frustoconical valve body 26. At its free longitudinal end, actuating shaft end 24 has a rotationally non-symmetric, in this case: polyhedral, coupling formation 24a for the torque-transmitting coupling to a drive that is not shown in the figures.

[0055] Actuating shaft end 24 is outwardly sealed with respect to the opening 22 in housing cover 18 penetrated by actuating shaft end 24 by a shaft seal 30 situated in housing cover 18.

[0056] Valve body 26 is accommodated in a valve body receiving space 32 in main housing body 20. A shell element 34 made of a friction-reducing plastic material is disposed between valve body 26 and a wall 32a bounding the valve body receiving space 32 radially outwardly. The friction-reducing plastic material may be selected, among other things, from polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene copolymer, polyoxymethylene, polyphtalamide, polyvinylidene fluoride, or a thermoplastic filled with friction-reducing filler, such as for example graphite or PTFE.

[0057] Alternatively, shell element 34 may be omitted and valve body 26 itself may be formed from the friction-reducing plastic material and contact wall 32a directly. As a further option, the valve body may have a core made of a conventional plastic, which is overmolded radially on the outside with a friction-reducing plastic or onto which a friction-reducing plastic is injection molded radially on the outside. In mating with the material of wall 32a, the friction-reducing plastic has a lower coefficient of friction than the material of the core of the valve body.

[0058] In the illustrated example, valve body 26 has two flow-through volumes 36 and 38, which are recessed from its frustoconical virtual enveloping surface (see the virtual enveloping surface H′ in FIG. 7) toward actuation axis B into valve body 26. Flow-through volumes 36 and 38 are physically separated from each other by valve body 26. In the example of FIG. 3, valve body 26 is situated in a rotational position, in which in FIG. 1 it connects the right and the lower connection formations 16 to each other via flow-through volume 38 to form a continuous fluid line and separates these from the left and the upper connection formations 16, which for their part are connected to each other by flow-through volume 36 to form a continuous fluid line.

[0059] On the inner side of housing cover 18, a prestressing means 40 is supported in the exemplary form of a compression spring. On its end opposite from housing cover 18, prestressing means 40 is supported on a sliding bushing 42, which is connected to prestressing means 40 in a torsionally fixed manner with respect to a rotation about actuation axis B, but which is able to slide relative to valve body 26. Sliding bushing 42 is merely in an abutting engagement with valve body 26.

[0060] Valve cover 26 and with it, if present, shell element 34 is subjected to pressure by prestressing means 40 in the direction of its tapering, that is, in the direction from its larger diameter end toward its smaller diameter end, thereby ensuring contact of the stressed components to one another. This makes it possible to compensate for wear, thermal deformation and the like. In addition, the tightness in the area of valve body receiving space 32 is thereby increased, since the joining gaps between valve cover 26 and shell element 34 or wall 32a as well as between shell element 34 and wall 32a are reduced and can only be increased against the pressure applied by prestressing means 40.

[0061] The shell element 34, which is torsionally fixed relative to main housing body 20 by form-locking engagement, has passages in the area of fluid lines 19 penetrating connecting formations 16, in order to connect these fluid lines 19 to valve body receiving space 32 and thereby, depending on the rotational position of valve body 26, to flow-through volumes 36 and 38.

[0062] Shell element 34 is inserted axially along actuation axis B into valve body receiving space 32 of main housing body 20. On a circumferential section, shell element 34 has a projection radially on the outside (not shown), which is insertable into an axial groove in main housing body 20 along actuation axis B, so that the shell element may be mounted in the axial direction and is fixated in the fully mounted state by the axial groove in the circumferential direction about actuation axis B.

[0063] As is shown in the right half of the drawing in FIG. 3, on its side opposite from the projection side of actuating shaft end 24, valve body 26 may have a centering protrusion 144, which projects into a corresponding centering recess 146 of main housing body 20. As is shown on the left half of the drawing of FIG. 3, such centering by way of centering protrusion 144 and centering recess 146 is not essential due to the frustoconical shape of valve body 26.

[0064] In a perspective view, FIG. 4 shows schematically valve body 26 in isolation, which is formed in one piece with actuating shaft end 24. The end face of valve body 26, on which sliding bushing 42 abuts in a sliding manner, is indicated by 26a.

[0065] A continuous rib structure 48 surrounds each flow-through volume 36 and 38 on the radial outer side of valve body 26. Rib structure 48 is thus a fluid-mechanical separating structure between the flow-through volumes 36 and 38.

[0066] Rib structure 48 comprises a single rib 50 projecting radially outward, whose radially outwardly facing free end face 50a, in the completely mounted and operational state, sealingly abuts either on the inner side of shell element 34 or on wall 32a of valve body receiving space 32. At a predefined axial prestress force exerted by prestressing means 40, the end face 50a abuts against the radially opposite component with higher contact pressure than valve body 26 without a rib, due to the considerably smaller area of end face 50a of rib 50 in comparison to the remaining frustoconical lateral surface of valve body 26.

[0067] Since only the end face 50a of rib 50 must sealingly abut against a radially opposite component, only end face 50a must be produced with high precision by injection molding, while the remaining surfaces of valve body 26 may be injection molded with higher tolerance. Hydrodynamic and hydrostatic forces, which act on the edges of rib 50 on both sides of end face 50a in the circumferential direction, mutually cancel each other out in terms of actual value.

[0068] FIG. 5 shows a variation of valve body 26 from FIG. 4. Valve body 26 from FIG. 4 corresponds completely to the one of FIG. 5 with the exception that rib structure 48 has two mutually parallel ribs 50 and 52 instead of just one rib. Accordingly, two end faces 50a and 52a, which lie in a common frustoconical virtual enveloping surface, are developed for making contact with a radially opposite component.

[0069] FIG. 6 shows a variation of the valve body of a valve assembly according to the present invention. A valve body 26, as it is known from FIG. 4, is coupled to an identical valve body 26′, which is merely rotated by 180° with respect to an axis orthogonal with respect to actuation axis B. Identical and functionally identical components and component sections on valve body 26′ are labeled by the same reference numerals as on valve body 26, but with the addition of an apostrophe.

[0070] Valve body 26 is developed in mirror symmetry with respect to two mutually orthogonal mirror symmetry planes that intersect each other in actuation axis B. In FIG. 6, one of the mirror symmetry planes is orthogonal with respect to the drawing plane of FIG. 6 and coincides with the representation of actuation axis B. The other mirror symmetry plane is parallel to the drawing plane of FIG. 6.

[0071] Valve bodies 26 and 26′ form a valve body configuration 62, whose valve bodies 26 and 26′, arranged coaxially with respect to actuation axis B, are coupled by a rotationally non-symmetric prism rod 54 for joint rotation about actuation axis B. Prism rod 54, however, allows for an axial relative movement of valve bodies 26 and 26′, so that the latter may be prestressed from their respective larger diameter end faces 26a and 26a′ toward each other.

[0072] Using only one drive, valve body configuration 62 allows for a greater, essentially a two-fold, quantity of fluid per unit of time to flow through the valve assembly in the otherwise identical operating position of the valve assembly, compared to a valve assembly that has only one valve body.

[0073] FIG. 7 shows a further variation of the valve body configuration as valve body configuration 62′. Valve body configuration 62′ corresponds to valve body configuration 62 from FIG. 6, with the exception that valve bodies 26 and 26′ face each other not with their smaller diameter end faces, but with their larger diameter end faces 26a. Accordingly, actuating shaft end 24 does not protrude from the larger diameter end face of a valve body 26 or 26′, but from its smaller diameter end face.

[0074] This specific embodiment has the advantage that a single prestressing means 56 situated axially between the two valve bodies 26 and 26′ suffices to apply pressure onto each valve body 26 and 26′ axially away from the respectively other valve body 26 or 26′ in its respective tapering direction.

[0075] The valve housing accommodating valve body configurations 62 and 62′ from FIG. 6 and FIG. 7, respectively, will normally comprise more than only two housing components in order to allow for a simple assembly of a valve assembly having a valve body configuration 62 or 62′. For example, such a valve assembly may have a main housing body and the latter may have one housing cover on each of two axially opposite sides.

[0076] The valve assembly presented here may be used advantageously in an electrically driven vehicle in order to conduct cooling liquid to thermally stressed units. The preferred fluid is a liquid, although gas shall not be excluded. In operation, the valve assembly particularly preferably has a water-glycol mixture flowing through it.

[0077] While considerable emphasis has been placed on the preferred embodiments of the invention illustrated and described herein, it will be appreciated that other embodiments, and equivalences thereof, can be made and that many changes can be made in the preferred embodiments without departing from the principles of the invention. Furthermore, the embodiments described above can be combined to form yet other embodiments of the invention of this application. Accordingly, it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.