Abstract:
Disclosed is a valve arrangement for selectively holding engine oil from leaking into an oil tank vent line. The valve arrangement includes an oil tank and a valve. The oil tank supplies engine oil to the engine lubrication circuit of a vehicle&#39;s internal combustion engine. The oil tank includes a vent opening that vents the oil tank. The valve closes the vent opening as a function of the oil pressure in the engine lubrication circuit.

Description:
PRIORITY  
         [0001]    This patent application claims priority to German Patent Application No. 103 28 178.9, filed Jun. 16, 2003; inventors: Eberhard Wizgall and Ralf Centmayer.  
         TECHNICAL FIELD  
         [0002]    The disclosure relates to a valve arrangement for temporarily closing a vent opening of an oil tank, an oil tank for supplying an engine lubrication circuit and a method for temporarily closing a vent opening of an oil tank.  
         BACKGROUND  
         [0003]    Generally, a suitable oil is used as lubricant for an engine lubrication circuit of an internal combustion engine for a vehicle. This oil is stored in an oil tank or reservoir that is incorporated in the engine lubrication circuit. For venting purposes the oil tank is connected to a venting line via a vent opening. The vent opening is provided on the oil tank such that when the oil tank is positioned in the normal way, i.e. when the vehicle is operating normally, no or only a little oil can escape through the vent opening.  
           [0004]    In the event of a non-regular position of the vehicle, e.g. if the vehicle turns on its side or turns right over, the oil tank of the combustion engine and hence the vent opening of the oil tank should be closed off in an oiltight manner. The irregular position of the vehicle mentioned above may occur for example in a water sports vehicle known as a jet ski.  
           [0005]    Jet skis are used for playing a water sport in which a person riding the jet ski travels over the surface of the water in the manner of a motorcycle. When performing acrobatic maneuvers or if the driver loses control of the jet ski, it may happen that instead of its normal position (essentially perpendicular to the surface of the water), the jet ski adopts an essentially horizontal recumbent position. This horizontal position may also occur when after traveling over the surface of the water the jet ski is set down on its side on the beach, for example.  
           [0006]    In such cases of horizontal or upside down positioning of the jet ski, it follows that the oil tank will also be positioned horizontally. The result of this is that when the vent opening is not closed the oil contained in the oil tank escapes into the vent line.  
           [0007]    When the engine is running or newly started up this oil would be taken in with the combustion air by the engine. Depending on the amount of oil this may cause malfunction or damage to the components.  
           [0008]    Typically, the vent opening or the attached venting line is closed off using electromagnetically operated valves (needle valves). A valve of this kind can be shut off by a break in the ignition circuit. Such an arrangement is expensive, however. The valve has to be suitably wired up and in addition it has to have a constant current supply. This results in additional costs both during manufacture and in use.  
           [0009]    When a valve of this kind is used in a jet ski the construction of an electromagnet for opening and closing the valve presents additional problems, as the valve also has to be resistant to salt water.  
         BRIEF SUMMARY  
         [0010]    In some embodiments of the invention there is a valve arrangement in a vehicle for selectively holding engine oil from leaking into an oil tank vent line. The valve arrangement includes an oil tank that supplies engine oil to an engine lubrication circuit of an internal combustion engine. The oil tank has a vent opening that vents the oil tank. The valve arrangement also includes a valve that closes the vent opening as a function of a pressure of the oil in the engine lubrication circuit.  
           [0011]    In some alternate embodiments there is an oil tank for holding and supplying oil to an engine lubrication circuit of an internal combustion engine of a vehicle. The oil tank has a vent opening, an oil inlet opening, and an oil outlet opening. The vent opening vents the oil tank and the oil outlet opening returns oil from the oil tank back to the engine via the engine lubrication circuit. A hydraulic valve is also included that closes the vent opening as a function of a pressure of the oil in the engine lubrication circuit. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    [0012]FIG. 1 shows in diagrammatic side view, partly in section, a preferred embodiment of the invention in a first state.  
         [0013]    [0013]FIG. 2 shows in sectional side view, from a different perspective, the embodiment of FIG. 1 in a second state. 
     
    
     DETAILED DESCRIPTION  
       [0014]    [0014]FIG. 1 shows an oil tank  2  with a valve arrangement according to one embodiment of the invention. The oil tank  2 , which is partly cut open at the top, has a valve  4  in its upper part. The valve  4  comprises a piston  10  sealed off by an O-ring, a closing spring or spring  8  and a closing ram  6 . A vent opening  3  of the oil tank  2  opens directly on to the closing ram  6  of the valve  4 .  
         [0015]    The oil tank  2  also has an inlet opening  13  for the oil, shown at the top in FIG. 1, and a return  15  for the oil to flow back to the engine at the bottom.  
         [0016]    The valve  4  is controlled by the pressure oil connection  12  to which is secured to a pressure line  7  of the engine lubricating or lubrication circuit. The oil, which is under pressure in the pressure line  7  in the engine lubrication circuit, presses against the piston  10  at the pressure oil connection  12 , this piston  10  acting upon or positioning the spring  8  and hence the closing ram  6  as a function of the force of the pressure of the oil.  
         [0017]    Thus, according some embodiments of the invention, the valve is connected to a pressure line of the engine lubrication circuit via a pressure oil connection, and the oil opens and closes the vent opening using the valve via the pressure oil connection as a function of the pressure. With these embodiments, variations in the pressure of the oil within the engine lubrication circuit can be utilized directly. The valve can easily be connected via the pressure oil connection. This is particularly the case when the oil tank is located close to the internal combustion engine.  
         [0018]    Any change in pressure essential to the operation of the valve arrangement or valve is passed on within a short time. For this purpose the engine lubrication circuit can be tapped and provided with the pressure line at any suitable point without any problem.  
         [0019]    In the view shown in FIG. 1, the valve arrangement or the oil tank  2  is in a closed state. This may be the case when the engine is switched off. In this case, the pressure of the oil inside the engine lubrication circuit is below a switchover pressure, with the result that the force of the pressure of the oil acting on the piston  10  at the pressure connection  12  within the engine lubrication circuit is not sufficient to counteract the force of the spring  8  to such an extent that the closing ram  6  is pressed downwards and the vent opening  3  is opened.  
         [0020]    In this embodiment, the vent opening is opened by means of the valve above a switchover pressure of the oil and closed below the switchover pressure. In an alternative embodiment, the vent opening is closed by means of the valve above a switchover pressure of the oil and opened below the switchover pressure. The operation of the valve may be adapted to suit specific and/or particularly favorable conditions. Depending on whether the pressure of the oil is built up or broken down faster within the engine circuit, the construction of the valve and/or actuation of the valve by connection to the pressure line via the pressure oil connection may be suitably or favorably designed.  
         [0021]    Additionally the switchover pressure may be set at a defined level so that any changes in the pressure conditions within the engine lubrication circuit can be taken into account in a flexible manner. This may be the case after assembly, for example. However, this also makes it possible to fit a valve arrangement to oil tanks of different combustion engines having correspondingly different oil pressures during operation.  
         [0022]    In some embodiments of the invention, it is provided that the vent opening is opened by means of the valve when the engine is running and shut when the engine is at a standstill. Venting of the oil tank only occurs and/or is necessary in these embodiments as long as the engine is running. Once the engine has been switched off, which may be caused for example by an unforeseen non-regular operational situation of the vehicle in which the engine is mounted, the valve arrangement according to the invention promptly shuts off the oil tank. This ensures that the oil cannot be sucked in accidentally. The combustion of oil and the resulting harmful emissions can be avoided. When there is too much oil and high pressure loading, burnt oil may be deposited, which detracts from the efficiency of the engine and, in the worst-case scenario, causes damage.  
         [0023]    In one embodiment, it may be specified in this respect that the switchover pressure is at least 0.5 bar. The vent opening and hence the oil tank are consequently opened at a pressure of more than 0.5 bar. In a normally operating internal combustion engine there is generally a pressure of at least 0.5 bar within the engine lubrication circuit. In another embodiment, the switchover pressure is at least 1.5 bar.  
         [0024]    [0024]FIG. 2 shows the valve arrangement according to one embodiment of the invention and the oil tank  2  in cross-section in side view, rotated through 90°. In addition to the components described in FIG. 1, FIG. 2 also shows venting channels  5 , vent line  22 , the inside  14  of the oil tank  2  holding oil  9 , a welded-in mesh  17  in the return means  15 , a cooling water inlet  18 , a cooling water jacket  19  and a cooling water outlet  20 .  
         [0025]    [0025]FIG. 2 shows the valve arrangement and hence the oil tank  2  in an open state. The force of the pressure of the oil on the pressure oil connection  12  on the piston  10  is sufficient to overcome the force of the spring  8  and press the closing ram  6  downwards. This is the case particularly when the pressure of the oil prevailing in the engine lubrication circuit exceeds the switchover pressure of the valve arrangement, which can be set to a defined level. In this state, it is possible for air to escape from the interior  14  of the tank through the venting channels  5 , as indicated by the arrows.  
         [0026]    Thus, according to certain embodiments of the invention, the valve may have a spring counteracting the pressure of the oil. As a result of this construction the valve can react directly and straightforwardly to the pressure of the oil within the engine lubrication circuit.  
         [0027]    As both FIGS. 1 and 2 show when viewed together, the valve arrangement is actuated by the pressure of the oil in the engine lubrication circuit. In the event of the motor coming to a standstill (pressure of the oil is less than the switchover pressure) the valve  4  is shut, actuated by the spring  8 . When the engine is running (oil pressure present, pressure of the oil is greater than the switchover pressure) the valve  4  opens. An opening or closing movement occurs as the result of the interaction between a force of the spring  8  and a force of the pressure of the oil acting upon the piston  10  at the pressure oil connection in this embodiment of the invention.  
         [0028]    A sealing seat for the valve  4  in the form of a plate valve, in particular, is constructed as a conical seat. The oil tank  2  is closed off in airtight and/or oiltight manner by the closing ram  6  that engages on the vent opening  3 .  
         [0029]    Thus, according to certain embodiments of the invention, the valve of the valve arrangement that temporarily closes a vent opening of an oil tank is constructed as a plate valve. By means of the plate valve the vent opening of the oil tank or a venting line for the oil tank can be opened and closed over a large cross section. The high level of force of the oil acting upon the spring of the valve prevents accidental closure of the valve. Thus, the operation of the valve is not affected and/or impaired by for example, forces of gravity or inertia generated by acceleration processes. The operation of the valve arrangement is also unaffected by vibrations. The high differential force which influences the function of the valve arrangement according to the invention by the interaction between the spring on the one hand and the pressure of the oil on the other hand ensures that the valve and hence the vent opening and the oil tank can be closed off tightly, in order to be airtight and/or oiltight, in particular.  
         [0030]    In contrast to the known solution with an electromagnetically operated valve, no external electrical control is required. This regulation is carried out directly hydraulically, i.e. in particular not electromagnetically and thus indirectly. The operation of the combustion engine or engine lubrication circuit in this respect is not dependent on external systems or equipment but is self-sufficient. The hydraulic actuation by means of the pressure of the oil allows a relatively high level of force for both the opening and closing movement. As a result, this mechanically actuated construction is unaffected by oscillations and closes with a strong sealing force.  
         [0031]    In addition, the construction is not critically affected by loss of seal at the actuating piston of the internal combustion engine as any oil leaks are diverted into the oil tank  2 .  
         [0032]    The oil tank valve arrangement above may be used in any internal combustion engine having an engine lubrication circuit with an oil tank. Obviously, in other embodiments, it may be that another device inside an internal combustion engine is affected by the pressure-dependent switching between two possible states. This is particularly advantageous when the running and stoppage of the engine are critical determinants for a change of state.  
         [0033]    The oil tank valve arrangement above may be applied to engines of all kinds of vehicles. It may be used to particular advantage in substantially “single-track” vehicles and/or vehicles which change their position even during normal operation. This may apply to motorcycles or snowmobiles, provided that they are not tipped on to their sides to park them when they are not operational.  
         [0034]    In a further embodiment the invention may be used in marine sports equipment of all kinds and particularly in jet skis. In the event of the engine cutting out, i.e. when no forward propulsion is possible, a jet ski traveling on the water tips on to its side. However, since the valve arrangement or the oil tank is sealed off in airtight and/or oiltight manner once the internal combustion engine has ceased operation, harmful escape of oil into the vent line  22  is prevented.  
         [0035]    Thus, different embodiments are disclosed. One skilled in the art will appreciate that the present invention can be practiced with embodiments other than those disclosed. The disclosed embodiments are presented for purposes of illustration and not limitation, and the present invention is limited only by the claims that follow.