The Invention refers to an automotive liquid distribution device for distributing a liquid, for example a liquid coolant, from one or more liquid sources to one or more liquid targets.

Generally, liquids can be distributed by a valve concept comprising several single valves which are controlled and switched separately by a control unit. This arrangement Is complex and expensive.

WO 2014/184783 Al discloses an Integrated automotive liquid distribution device with three hydraulic ports of which two hydraulic ports are defined by a static housing defining two port openings and a rotatable valve element comprising corresponding port openings which are in-line with the housing body opening in an open position of the valve element. Both swltchable ports are provided with a shiftable sealing sleeve which is, respectively, guided within the housing body port opening and which Is pushed towards the rotatable valve element by a spring element. The fluldic sealing of the valve is provided by a separate conventional sealing ring.

The preload force of the spring element has to be relatively high to guarantee a sufficient fluldic sealing even at relatively high pressure differences. A high preload force of the spring element causes relatively high friction and wear. The conventional sealing ring has to be of very good quality to guarantee a long-term and high sealing quality In particular at high pressure differences. It is an object of the Invention to provide an automotive liquid distribution device with Improved sealing quality and reduced costs.

This object is solved with the automotive liquid distribution device with the features of claim 1. The automotive liquid distribution device according to the invention is provided with at least one controllable hydraulic port for selectively distributing a liquid from one or more Inlet ports to one or more outlet ports. Every single controllable hydraulic port can be an Inlet port or an outlet port. Every controllable hydraulic port defines a high pressure at the Inlet side and a low pressure at the outlet side of the respective port. The pressure difference between the Inlet side and the outlet side might be minimal with an open valve but can be more than 100 mbar with a closed valve. The term "controllable" means that the respective hydraulic port can be opened gradually so that the flow rate generally can be controlled steplessly, If a gradual control of the flow rate should be required.

The liquid distribution device is provided with a static housing defining all ports, namely the switchable hydraulic ports and the non-swltchable hydraulic ports. A movable valve element is provided inside the housing, the valve element being movable with respect to the static housing. The valve element is actuated and driven by a valve actuator, preferably by an electric actuator motor. The static housing is defined by a housing body defining a port opening for every port switchable. The valve element Is defined by a valve element body defining at least one valve element opening for every switchable port. The valve element opening Is In-line with the corresponding housing body opening in an open position of the valve element, with respect to this port. The valve element can have different opening positions, and can selectively and/or commonly open and/or close the switchable hydraulic ports of the distribution device. Additionally, the hydraulic ports can preferably be partially opened or closed in order to regulate the flow rate.

The switch able housing ports are provided with a sealing arrangement respectively. The sealing arrangement comprises a shiftable sealing sleeve with a guidance part being axlally shiftable and shlftably guided within the corresponding housing body port opening. The axial direction In this context Is the axis of the opening which is basically the flow direction of the liquid through the housing body port opening.

The sealing sleeve Is also provided with a support part which Is supported by and sealfngly gliding on the outer surface of the valve element body. The guidance part is the distal part and the support part Is the proximal part of the sealing sleeve. In this context, the term 'proximal' means In direction to the valve element and, and the term 'distal' means In direction to the corresponding hydraulic port opening.

The sealing arrangement also comprises a separate and relatively flexible elastic sealing ring which Is X-shaped or C-shaped in cross-section and comprises a proximal ring-like sealing lip and a distal ring-like sealing lip, both ring lips defining a ring-groove between them. The proximal sealing lip is supported at and by the sealing sleeve support part and the distal sealing lip Is supported at an Inside surface ring surrounding the opening edge of the corresponding port opening. The circular groove of the sealing ring opens to the high pressure so that the two sealing lips of the flexible sealing ring are pushed apart from each other by the pressure difference between the high pressure and the low pressure. Preferably, the sealing ring is less stiff than the sealing sleeve.

The proximal sealing lip is supported at the sealing sleeve support part so that the sealing sleeve is axlally pushed against the valve element so that the sealing quality between the sealing sleeve support part and the valve element Is improved. The sealing sleeve support part is provided with a structure which supports the proximal sealing lip at least In part in axial direction. Alternatively, the sealing sleeve and the sealing ring could also be produced as one part.

The distal sealing lip Is directly supported by the housing body so that no leakage can appear in this region.

When the corresponding valve is open, the pressure difference between the high-pressure, which is the pressure at the inlet side of a hydraulic port, and the low-pressure, which is the pressure at the outlet side of a hydraulic port, is relatively small so that only a relatively small local force Is caused pushing the two sealing lips apart from each other. Since the pressure difference is relatively low, the sealing lips are not pushed very strong against the corresponding parts so that leakage could appear theoretically. But leakage of an open valve port would not be a problem because the valve is open anyway. On the other hand, the relatively low forces on the sealing lips avoid wear at the sealing lips when the valve element is moving.

When the valve is closed, namely when the valve element opening Is not in-line or overlapping with the corresponding housing body opening anymore, the pressure difference substantially Increases so that both sealing lips are pushed with a relatively high force against the corresponding surfaces of the sealing sleeve support part and the port opening ring surface of the housing body. This results In a high sealing quality when the valve is closed so that no leakage through the closed port appears or is minimized. No separate spring element is necessary anymore to push the shlftable sealing sleeve against the valve element.

According to a preferred embodiment of the Invention, at least one hydraulic switchable port Is defining an outlet port so that the high pressure is inside of the valve element and the ring-groove is open to Its radial outside so that the pressure Inside the valve element Is always present in the sealing ring-groove. When the corresponding port is closed, the high pressure inside the valve element is present In the sealing ring- groove so that the sealing quality is high when the corresponding port is closed.

Alternatively, or additionally, at least one hydraulic switchable port is defining an inlet port so that the high-pressure Is outside of the valve element and the low-pressure Is inside of the valve element. The ring- groove Is open to the radial inside of the sealing ring namely to the region of high pressure when the valve element is in the closed position.

According to a preferred embodiment, a preload ring spring element is provided in the ring- groove to spread the lips apart. The spring element guarantees that even at low or no pressure differences both sealing lips are In contact with the corresponding surfaces of the housing and the valve element. As soon as the pressure difference increases, it is guaranteed that no pressure equalization can locally appear because of a local raise of the corresponding sealing lip.

Generally, the valve element body can be plane or flat, or can be spherical In shape, but preferably is cylindrical In shape. The general form of the valve element can be cylindrical whereas the ring-portions comprising the valve element openings can be spherical. In the latter case, the flexible sealing ring is circular. If the valve element Is completely cylindrical then the flexible sealing ring has a wave-like course In the axial extension. According to a preferred embodiment of the invention, the sealing sleeve is provided with an equilibrium channel connecting a dead volume with the low-pressure. The dead volume can appear between the distal sealing lip and the housing body. For providing the wished pressure difference at the distal sealing Hp, it is necessary that the low pressure Is always present at the distal side of the distal sealing lip. The equilibrium channel makes sure that this is always the case. The equilibrium channel can be a bore or also can be an open slit in the sealing sleeve body.

Preferably, the support part of the sealing sleeve is defined by a ring-like lateral collar which Is lying with its complete proximal collar surface at the distal valve element body surface so that a high sealing quality is guaranteed. The proximal sealing lip Is supported by the distal side of the support part collar.

According to a preferred embodiment, the flexible sealing ring is made out of rubber. Preferably, the sealing sleeve Is made out of plastic. The sealing sleeve Is less flexible than the sealing ring.

Two embodiments of the Invention are explained with reference to the enclosed drawings, wherein figure 1 shows schematically a longitudinal section of an automotive liquid distribution device with one inlet port and three switchable outlet ports, figure 2 shows one outlet port of the distribution device of figure 1 more detailed, and figure 3 shows another embodiment of a hydraulic port, namely a switchable Inlet port. Figure l shows an automotive liquid distribution device 10 for selectively distributing a liquid coolant, namely cooling water, from a liquid coolant source 14, for example a coolant pump, to three different liquid coolant targets 151, 152, 153. The distribution device 10 is provided with one non-controllable inlet port 44 and with three controllable hydraulic outlet ports 41, 42, 43 which are controllable to selectively distribute the coolant flowing into the distribution device 10 via the Inlet port 44 to the different coolant targets 151, 152, 153. The distribution device 10 is provided with a static housing 40 which is basically cylindrical In shape and a rotatable cylindrical valve element 20. The static housing 40 is defined by a metal housing body 40' with an axial inlet port 44 at one longitudinal end of the cylindrical housing body 40', and three radial outlet ports 41, 42, 43 at different circumferential angles and longitudinal positions. The radial outlet ports 41, 42, 43 are defined by cylindrical openings 50 surrounded by a cylindrical housing collar 51, respectively, which openings 50 have a radial orientation with respect to the rotation axis 27 of the rotatable valve element 20. The valve element 20 Is defined by a cylindrical valve element body 20' which is rotatably supported by two ring friction bearings 16, 16' at both longitudinal ends of the housing body 40'. The valve element body 20' is provided with three valves element openings 21-23 which are in-line with the corresponding switchable hydraulic port opening 50 In an open valve body position with respect to the corresponding port openings 50 of the outlet ports 41-43. The valve element 20 is driven by an electrical valve actuator 12 via an axial motor shaft 13 and three radial struts 14 which are connected to the valve body 20'. In the first opening position of the valve element 20, a first and a second outlet port 41, 42 are completely open and a third outlet port 43 Is completely closed, as shown in figure 1. In a second opening position (not shown) of the valve element 20, a third outlet port 43 is completely open, and the first and the second outlet ports 41, 42 are closed. In any other valve element position, all outlet ports 41- 43 are completely closed. The valve element openings can be positioned In any other way to define other switching combinations of the outlet ports 41-43.

In the first embodiment of the distribution device 10 shown in figures 1 and 2, all three switchable ports 41-43 are outlet ports so that generally high-pressure Ph is present inside of the valve element 20 and low- pressure PI is present in the port openings 50 outside of the valve element 20. The pressure difference between the high-pressure Ph and the low- pressure PI is relatively low when the corresponding outlet port 41-43 Is open and can be relatively high when the outlet port 41-43 is closed, for example higher than 100 mbar. Every outlet port 41,42,43 Is provided with an outlet sealing arrangement 200 comprising a relatively stiff and sh!ftable sealing sleeve 60, a flexible sealing ring 80 and a preload ring spring element 90. The second outlet port 42 including the sealing arrangement 200 is shown in more detail in figure 2. As can be seen in figure 2, the sealing arrangement 200 is substantially arranged in the ring space defined between the cylindrical housing body 40' and the hollow-cylindrical valve element body 20'. The sealing arrangement 200 comprises the radially shiftable sealing sleeve 60 made out of a relatively stiff plastic sealing sleeve body 61. The flexible and In cross-section C-shaped sealing ring 80 is made out of a rubber and the preload ring spring element 90 is made out of a metal wire. The sealing sleeve 60, the sealing ring 80 and the ring spring element 90 are axially symmetric and are co -axially provided with respect to the radial port axis 52.

The sealing sleeve 60 is provided with a cylindrical and neck-like guidance part 62 which is shiftably supported within the corresponding port opening 50 and with a collar-like support part 64 which is supported by and sealingly gliding on the cylindrical outer surface 32 of the valve element body 20'. The outer cylindrical surface 68 of the guidance part 62 is of approximately the same diameter as the corresponding cylindrical port opening 50 so that the sealing sleeve 60 is approximately play-free gliding within the port opening 50. Preferably, there will be a small radial clearance of about 0,3 - 0,5 mm to avoid a separate equilibrium channel. The clearance allows a self-positioning of the collar on the valve element. The proximal surface 72 of the sealing sleeve 60 Is also cylindrical with approximately the same radius as the outer valve element's body surface 32 so that the sealing sleeve's proximal surface 72 is directly in contact with the corresponding outer surface 32 of the valve element 20 at a relatively large ring-like surface. The sealing sleeve 60 is provided with a cylindrical bore 66 which, In the open valve state, is in-line with and of approximately the same diameter as the corresponding valve element opening 22.

The sealing ring 80 is C-shaped in cross section and is defined by a sealing ring body 84 of rubber. The sealing ring 80 comprises a proximal sealing lip 81 and a distal sealing lip 82 which are connected to each other at their radially inner edges so that a ring-groove 85 Is defined between them which is open to the radial outside with respect to the port axis 52. The distal sealing lip 82 is supported at the housing body inside ring surface 55 surrounding the inside edge of the port opening 50. The proximal sealing Up 81 Is supported at the distal side of the sealing sleeve support part 64.

The sealing sleeve 60, the ring surface 55 and the sealing ring 80 enclose a ring-like dead volume 99 which is connected to the low-pressure PI in the port opening 50 via an equilibrium channel 70 which Is realized as a longitudinal groove in the outer surface 68 of the guidance part 62 of the sealing sleeve 60.

If there is a pressure difference between the high-pressure Ph within the valve element 20 and the low-pressure PI In the port opening 50, the sealing lips 81, 82 of the sealing ring 80 are spread apart so that the sealing lips 81, 82 are pushed against the corresponding surfaces of the housing body 40' and the sealing sleeve 60. This Is always the case when the port 42 Is completely closed so that the valve element opening 22 is not overlapping with the port 66, so that the port 42 is completely closed and no liquid leaks into the outlet port 42.

A preload ring spring element 90 Is provided In the ring-groove to spread the lips 81, 82 apart as long as no relevant pressure difference is present between the high-pressure Ph and the low-pressure PI.

Figure 3 shows an alternative embodiment of a hydraulic port 141 which Is realized as an inlet port 141. The pressure situation at the Inlet port 141 is different of that of the outlet ports shown in figures 1 and 2, so that the high pressure Ph is upstream of the valve element 20 and the low pressure PI is downstream of the valve element 20, if the port is closed. As a consequence, the sealing arrangement 100 of the Inlet port 141 Is arranged inverse compared to the sealing arrangement 200 of an outlet port 41-43.

The valve element 20 is provided with a valve element opening 22' which is an inlet opening. The housing 40 defining the inlet port 141 is defined by a housing body 40" which is provided with a housing collar 51' and with a ring-like recess radially inwardly which defines the inside ring surface 155 of the housing 40 and the cylindrical port opening 150.

The shlftable sealing sleeve 160 is defined by a sealing sleeve body 161 which Is provided with a cylindrical guidance part 162 and with a collar- like support part 164 which extends from the guidance part 162 radially inwardly with reference to the radial port axis 52. The proximal surface 72' of the sealing sleeve support part 164 is supported by the distal surface 32 of the valve element 20. The cylindrical outside surface 68' of the guidance part 162 Is supported by the inner surface of the cylindrical port opening 150. An equilibrium channel 170 is provided at the outside surface 68' of the sealing sleeve guidance part 162. The equilibrium channel 170 fluidically connects the dead volume 199 with the low pressure PI. The flexible sealing ring 180 is defined by rubber sealing ring body 110' which Is provided with two sealing lips 181, 182 which are connected to each other at their radially outer edges so that the ring-groove 185 opens to the radial inside referring to the port axis 52. A preload ring spring element 190 Is provided at the inner surface 130 of the ring-groove 185. The spring element 190 is realized as a, seen in cross section, C-shaped metal ring spring body which directly spreads the sealing lips 181, 182 apart.