DE102009030500A1 - Liquid filter system of a fluid circuit - Google Patents

Abstract

A liquid filter system (16) of a liquid circuit (10), in particular a fuel injection system with a fuel return, is described. The liquid filter system (16) has at least one filter element (36), a raw liquid inlet (28) and a liquid outlet (34), each of which can be connected to a liquid reservoir (12). The liquid filter system (16) also has a clean liquid outlet (30) which can be connected to a consumer (20), the filter element (36) being arranged functionally between the raw liquid inlet (28) and the clean liquid outlet (30). A raw side (36a) of the filter element (36) is correspondingly connected to a control unit (66) which has a temperature detection unit (66b) for controlling a valve (66a) contained in the control unit (66) as a function of a liquid temperature of a liquid in the liquid circuit (10), as a result of which the liquid which has not been removed by the consumer (20) can at least partially be fed back to the raw side (36a) of the filter element (36). A liquid pump (78) is provided at least to fill the filter element (36) with liquid.

Description

Technical area

The The invention relates to a fluid filter system of a fluid circuit, in particular a fuel injection system with a fuel return, comprising at least one filter element, a Rohflüssigkeitseinlass and a liquid outlet, each with a liquid reservoir connectable, and a clean fluid outlet, with A consumer is connectable, wherein the filter element functional between the raw fluid inlet and the clean fluid outlet is arranged and a raw side of the filter element corresponding connected to a control unit, which is a temperature detection unit has for controlling a valve contained in the control unit depending on a liquid temperature of a Liquid in the fluid circuit, causing the at least by the consumer not taken liquid partially fed to the raw side of the filter element again is.

Further The invention relates to a bendable fluid conduit and a filter element of a fluid filter system, which can be connected to each other.

Furthermore The invention relates to a check / throttle valve and a filter element of a liquid filter system, the can be connected to each other.

Known market Liquid filter systems are used in liquid circuits used in which a liquid, such as Water, oil or fuel, is filtered and at least a partial return of the liquid takes place in the liquid storage.

State of the art

From the DE 100 30 324 A1 For example, a liquid filtration system of a liquid loop for filtration is known. The liquid circuit has a liquid reservoir, a liquid pump, a consumer, a filter element and a control unit. The filter element can be at least partially supplied to a heated liquid. In the liquid circuit, the liquid is pumped with the liquid pump from the liquid storage in liquid lines, cleaned by the filter element and fed to the consumer. The liquid not required by the consumer is supplied via a liquid return line to the control unit, which supplies the liquid to the filter element or the liquid reservoir, depending on the liquid temperature. The control unit and the filter element are incorporated in a common housing, which has a Rohflüssigkeitseinlass, a Reinflüssigkeitsauslass, a liquid return and a liquid outlet. Often it is necessary that the consumer always fluid in an optimal state, especially under optimal pressure and / or temperature and / or optimum amount, is provided.

Of the Invention is based on the object, a liquid filter system, a bendable fluid conduit, a connectable thereto Filter element, a check / throttle valve and a with this connectable filter element of a fluid circuit to create which is always simple and efficient, especially after a start of operation as quickly as possible, the provision of liquid in optimal condition for the consumer enable.

Disclosure of the invention

These The object is achieved by a liquid pump at least for priming of the filter element with liquid.

According to the invention So with the liquid pump, the filter element with liquid be prefilled, so that at a start of operation, in particular after a filter change, the consumer quickly liquid is ready. The liquid pump can basically at different points in the fluid circuit the raw side or be arranged on the clean side of the filter element. Overall, so can liquid temperature, pressure and quantity on the consumer side, in internal combustion engines can be referred to as rail, simply always optimally regulated become.

at In an advantageous embodiment, a liquid return connectable to the consumer and corresponding to the control unit be connected. The liquid return allows a return of unneeded liquid from the consumer side. The returning liquid can be used to preheat newly supplied liquid be used from the liquid storage.

advantageously, The liquid pump can functionally between the Rohflüssigkeitseinlass and the raw side of the filter element can be arranged. This is space saving and has a positive effect on the length of the needed Liquid lines off.

In a further advantageous embodiment, a pressure control means for controlling the fluid pressure at least on the consumer side of the fluid circuit, wherein the pressure control means may be arranged downstream of the liquid return, if one is given. The pressure control means ensures that On the consumer side, there is always the optimum liquid pressure for the consumer. Depending on the liquid temperatures, part of the liquid not removed by the consumer is supplied to the filter element, whereby the cold liquid from the liquid reservoir mixes with the warmer liquid from the consumer side, which has an overall positive effect on the state, in particular the consistency and the flowability Liquid for the consumer.

at In a further advantageous embodiment, the temperature detection unit be designed so that it depends on the valve Liquid temperature of the liquid on the raw side the filter element or optionally a time-averaged mixing temperature from a liquid return from the consumer side can control, provided a liquid return given is. In this way, the valve can depend on the liquid temperature in the flow or in the return a so-called Rails be regulated.

advantageously, the temperature detection unit may be a spring element of a Shape memory material, in particular Nitinol, or a bimetal or have a wax element. With a shape memory material can simply be realized a spring element, which is a temperature-dependent realized increased closing pressure of the valve. Parallel acting to the spring element of shape memory material In addition, a spring element, in particular made of steel, with a substantially temperature-independent spring force be provided, which has a minimum opening pressure of the Valves defined. The two spring elements can thereby be coordinated so that the temperature independent Spring element at liquid temperatures of less than For example, 20 ° C takes over the control of the valve. Nitinol is an easy to process and more reliable Shape memory material. Temperature-dependent spring elements made of bimetal have a minimal hysteresis, so with them a sufficiently reproducible switching point both during the warm-up process as well as the cooling process is realized. wax elements are simple and reliable switching elements.

at In a further advantageous embodiment, the liquid pump reversibly operable, in particular a gear pump or a diaphragm pump be an inlet / outlet of the liquid pump for Liquid can with a collecting area for separating liquid be connected to the raw side of the filter element, another Inlet / outlet of the liquid pump connected to the raw liquid inlet Functionally related may additionally with a Abscheideflüssigkeitsauslass the liquid filter system be connected, and control means may be provided with those depending on the liquid conveying direction the liquid pump optionally the connection of the liquid pump to the raw liquid inlet or to the separation liquid outlet can be opened. The control means and the liquid pump You can be so coordinated that you alone by reversing the liquid conveying direction the Open fluid lines in the way respectively close that optionally from the liquid storage Fluid pumped or with the same fluid pump Abscheideflüssigkeit from the collection area of the filter element via pumped the Abscheideflüssigkeitsauslass from the filter system can be. The separating liquid may be when using the system as a fuel filter system, for example to act water, which transported in the filter element of the Fuel is deposited and collected in the collection area can. The separating water should reach a predetermined Maximum level and / or regular Be pumped out intervals, hence the function of the filter element is not affected. The refilling of the liquid and the pumping of the Abscheideflüssigkeit can thus with a single liquid pump to be carried out what the amount of components and the required space reduced.

Conveniently, the control means may comprise at least two check valves which are functional between the fluid pump and the raw liquid inlet and the liquid pump and the Abscheideflüssigkeitsauslass are arranged such that optionally the connection to the raw fluid inlet or the connection to the separation liquid outlet open is. Check valves are simple and reliable and close automatically when reversing the liquid conveying direction. They can be spring or weight loaded and so in Passage direction dependent on the fluid pressure be opened automatically. The two check valves can be arranged so that they respect the conveying direction of the liquid pump opposite Have locking directions. Alone by the reversal of the conveying direction so the desired line branch opens automatically become.

In a further advantageous embodiment, an electronic control system for controlling at least the liquid pump and a bendable liquid line may be provided, which leads from the liquid pump to a collecting region for Abscheideflüssigkeit on the raw side of the filter element, wherein the bendable liquid line extends removably in the filter element. With the control electronics, the liquid pump can be controlled as needed. The liquid The pump can also be started and stopped gently, which significantly reduces wear. The conveying direction can simply be reversed in order to use the liquid pump, optionally for repumping liquid from the liquid reservoir or for pumping off separating liquid from the filter element. The liquid pump can be arranged in the spatial vicinity of the filter element, preferably on its upper side, and can be connected via the bendable liquid line to the collecting region of the separating liquid at or in the lower region of the filter element. The bendable liquid line can be protected in the interior of the filter element and accommodated to save space. It can be easily placed in the filter element, even in confined spaces, because of its flexibility when changing filters.

Around the achievement of a certain maximum level of Abscheideflüssigkeit In the collection area easy to capture, can advantageously the bendable fluid line in a collecting area assigned Section Sensors, in particular electrodes, for detecting separation liquid and signal lines can from the sensors to the control electronics along the bendable liquid line run. In this way, the control electronics spatially removed from the sensors mounted above the filter element so that in case of damage or a filter change about down flowing liquid can not harm.

advantageously, For example, the pressure regulating means can move in the direction of flow tapered inflow area for the Liquid and a subsequent spring-loaded Have valve. About the inflow area and the valve in common can increase the fluid pressure on the Consumer side. With the inflow area If a pressure reduction upstream of the valve is achieved, so that in case of damage, such as the breakage of a spring of the valve, a reduced system pressure on the consumer side can be obtained, which allows emergency operation of the fluid circuit. In the inflow area, moreover, the flow velocity the liquid reduces, which positively affects the life of the valve.

at Another advantageous embodiment may be functional between the clean side of the at least one filter element, in particular one Prefilter element, and the liquid outlet another Filter element, in particular a main filter element, be arranged. By using two filter elements connected in series the filter effect is significantly improved overall. The first Filter element can advantageously with the invention Valves, the control unit and the liquid pump connected so that there is the cold start management of the liquid filtration system is concentrated.

Conveniently, can the raw side of the other filter element with the clean side the at least one filter element and possibly with the pressure control means be functionally connected and the clean side of the other filter element can be functionally connected to the clean fluid outlet be. In this way, the further filter element with the consumer and optionally form a sub-circuit with the pressure control means, the Liquid supplied from the first filter element can be. The from the liquid storage the first Filter element supplied liquid can over the control unit with the liquid not removed by the consumer be preheated from the subcircuit.

Further can advantageously the raw side of the at least one filter element or possibly the raw side of the further filter element over a bleed valve with the liquid outlet be functionally connected, over the deposited in the respective filter element Gases, especially air, can be discharged.

at a further advantageous variant, the clean side of at least a filter element or possibly the clean side of the further filter element over a check / throttle valve with the clean fluid outlet be functionally connected. The check / throttle valve combines the function of a check valve, namely a return of liquid from the consumer in the further filter element or in the at least one filter element to prevent, with a restriction of the liquid flow. The degree of throttling can preferably be automatically dependent be adjusted by the type of filter elements used. Preferably, this can be done on the filter elements used Be arranged actuator, which automatically at the assembly of the respective filter element the throttling degree of Setback / throttle valve sets. The reverse lock function is particularly advantageous especially when using the liquid filter system for consumers who have longer downtimes, during which the consumer side of the fluid circuit not allowed to run empty. So this variant is particularly favorable when used with emergency generators.

Advantageously, a main liquid pump can be arranged in the liquid circulation, in particular downstream of the at least one filter element. The main liquid pump can be independent of the former Flüssigkeitsspum be operated pe. In this way, separating liquid can be discharged from the collecting area of the filter element with the first-mentioned liquid pump, while the liquid in the liquid circulation is conveyed with the main liquid pump.

Conveniently, The main liquid pump can not be integrated into the liquid filtration system and the liquid filtration system can be appropriate Line connections for the main liquid pump exhibit. The main liquid pump can be so spatially separated from the liquid filter system preferably solid be arranged in or on the liquid storage. To this Way can also be a large-sized main liquid pump can be used without taking up the space for the actual Liquid filter system thereby increased becomes.

Further can be functional between the liquid reflux and the liquid outlet a vent valve be arranged on the gases, in particular air, from the consumer side of the fluid circuit discharged can be. The vent valve can with the pressure control valve act in such a way that even at a gas discharge always an optimal fluid pressure on the consumer side is ensured.

Conveniently, can the vent valve spatially above the Be arranged pressure control means. That way you can the incoming at the pressure control valve gases rise and more efficient the vent valve be discharged.

Especially Advantageously, the liquid filter system as a module be constructed. A module can be easily preassembled and with the consumer, the Liquid storage and possibly the main liquid pump get connected. Through housing-fixed connections is a quick and easy installation of the fluid circuit possible.

The Filter element and / or optionally the further filter element can advantageously be a replaceable filter, the replaceable filter element is inexpensive and can be easily exchanged.

The Task is also solved according to the invention through the bendable liquid line, the sensors, in particular Electrodes, for the detection of separating liquid and Having signal lines from the sensors to control electronics, which run along the bendable fluid line. The bendable fluid line has the advantage that they simply at the same time a hydraulic connection from a collecting area of the filter element, also referred to as "bowl" can be, with a fluid pump and an electrical connection of sensors in the collection area with electronics outside implemented the filter element. The bendable fluid line can be simple and flexible, especially through a channel in the center be guided of the filter element. With the help of the sensors can operating states in the collection area, in particular a Liquid level and / or liquid temperature, be detected in order to optimize the state of the liquid.

The Task is also according to the invention solved by the filter element being a receiving element, in particular a central tube, has for a particular bendable fluid conduit according to the invention, making the filter element easy with a bendable fluid line can be equipped.

Also the object is achieved according to the invention, that the check / throttle valve with a filter element can be mechanically connected, wherein an actuating element the filter element with a special geometry with an attack area a throttle element of the check / throttle valve with a corresponding counter-geometry can interact in such a way that the check / throttle valve in its by a non-return element the check / throttle valve predetermined passage direction With fluid can be flowed through. This way you can the check / throttle valve only by mounting a filter element, this is an actuator with the special geometry has opened in the forward direction and thus in operation be set. In this way it is prevented in the case of Using a wrong or incorrectly mounted filter element damage occurs in the liquid filter system. This allows the liquid to optimally Condition is provided.

A further inventive solution to the problem is that the further filter element is an actuating element with a special geometry that includes an attack area a throttle element of a particular invention Check / throttle valve with a corresponding counter-geometry can cooperate such that the throttle element an opening state accepts. So can a corresponding check / throttle valve by the assembly of the filter element according to the invention opened in the forward direction and thus put into operation , thereby ensuring the optimal state of the liquid provided is possible. Brief description of the drawings

Further advantages, features and details of the invention will become apparent from the following description, in the embodiments of the inventions tion will be explained in more detail with reference to the drawing. The person skilled in the art will expediently also individually consider the features disclosed in the drawing, the description and the claims in combination and combine them into meaningful further combinations. Show it:

1 schematically a liquid circuit with a liquid filter system;

2 schematically an isometric view of the liquid filter system of the 1 ;

3 a control unit of the liquid filter system of the 1 and 2 on average;

4 a pressure regulating valve of the liquid filter system of the 1 and 2 on average;

5 a first embodiment of a prefilter with a flexible liquid line of the liquid filter system of the 1 and 2 on average;

6 schematically a detailed view of a liquid pump of the liquid filter system of the 1 and 2 on average;

7 schematically a longitudinal section of a Abscheideflüssigkeitsaustragventils the liquid filter system 1 and 2 ;

8th 1 schematically shows a section of a valve assembly with a pre-pump check valve and an inlet check valve of the liquid filter system of the 1 and 2 ;

9 schematically a first embodiment of a check / throttle valve of the liquid filter system of the 1 and 2 with a main filter according to a first embodiment in section;

10 schematically a trained as an alternating filter second embodiment of a main filter of the liquid filter system of the 1 and 2 on average;

11 schematically a trained as an alternating filter second embodiment of a pre-filter of the liquid filter system of the 1 and 2 on average;

12 schematically a second embodiment of a check / throttle valve of the liquid filter system of the 1 and 2 on average.

Embodiment (s) of the invention

In the 1 is a fluid circuit 10 shown schematically. The fluid circuit 10 includes a liquid storage 12 , one of the liquid storage 12 Outgoing raw fluid line fourteen , one to the raw liquid line fourteen subsequent liquid filtration system 16 , a clean fluid line 18 which is a consumer 20 with the liquid filter system 16 connects, a liquid return 22 and a liquid discharge 24 , The consumer 20 For example, may include a fuel injection system of an internal combustion engine, the liquid fuel (liquid) is supplied from a fuel storage. So that a liquid in the liquid circulation 10 is a main fluid pump 26 provided which a fluid pressure in the fluid circuit 10 generated and has a larger volume than the consumer 20 can take maximum. The main liquid pump 26 is outside of the liquid filtration system in this embodiment 16 arranged. The arrangement of the main liquid pump 26 but is within the fluid circuit 10 arbitrary, whereby an arrangement, for example, in the liquid filter system 16 , in the liquid storage 12 or another fluid-carrying line is possible.

The components of the fluid filtration system 16 which in the 1 within the with 27 designated rectangular frame are arranged, as in 2 shown, built as a module. The liquid filter system 16 can be preassembled easily with the liquid storage 12 and the consumer 20 get connected.

The module of the liquid filter system 16 has a raw fluid inlet 28 and a liquid outlet 34 , via which by means of the raw liquid line fourteen and the liquid discharge 24 the liquid filter system 16 separable with the liquid storage 12 connected is.

Furthermore, the module of the liquid filtration system 16 a liquid outlet 30 and a liquid return 32 on, via the means of the clean fluid line 18 and the liquid return 22 the liquid keitsfiltersystem 16 separable with the consumer 20 connected is.

The liquid filter system 16 has a prefilter 36 and a main filter 38 on, each one raw page 36a respectively 38a and a clean side 36b respectively 38b exhibit. The respective raw pages 36a . 38a and clean pages 36b . 38b are sealingly separated. The raw fluid inlet 28 is via a supply line 40 with the raw side 36a of the pre-filter 36 connected.

In the supply line 40 is a weighted inlet check valve 42 arranged, which is a return of liquid from the raw side 36a back to the raw fluid inlet 28 should prevent. The clean side 36b of the pre-filter 36 is via a main pump supply line 44 with a pump line outlet 46 the liquid filter system 16 connected. To the pump line outlet 46 is a suction line 48 the main liquid pump 26 detachably connected.

From the pressure side of the main fluid pump 26 leads a pressure line 50 to a pumping line inlet 52 the liquid filter system 16 , The pumping line inlet 52 is via a main pump Ablaufleitunng 54 with the raw side 38a of the main filter 38 connected. From the clean side 38b of the main filter 38 performs a main filter clean line 56 to the clean fluid outlet 30 , In the main filter clean line 56 is a below explained in more detail spring-loaded check / throttle valve 58 with, among other things, a return of liquid from the clean liquid outlet 30 to the clean side 38b of the main fluid filter 38 is prevented.

In the liquid filter system 16 is also a return line 60 integrated, which the liquid return 32 with the liquid outlet 34 combines. In the return line 60 is a return bleed valve 62 arranged in the form of a check valve. The return bleed valve 62 prevents backflow of liquid and / or gas from the liquid outlet 34 towards the liquid return 32 , A vent section of the return line 60 downstream of the return bleed valve 62 is in 1 dashed lines, which should be indicated that in this area essentially gas, preferably air, from the liquid circulation 10 is discharged. Normally, the liquid left by the consumer 20 is not taken, except for the permanent leaks caused by the return bleed valve 62 and a main filter venting valve discussed below 74 be formed within the fluid filtration system 16 on the side of the consumer 20 , The consumer side of the fluid circuit 10 can also be referred to as "rail" in fuel systems. Upstream of the return bleed valve 62 branches a control unit connection line 64 from the return line 60 and leads to the raw side 36a of the pre-filter 36 , In the control unit connection line 64 is a control unit 66 arranged in 3 shown in section. With the control unit 66 becomes a liquid reflux from the liquid return 32 to the raw side 36a depending on the temperature of the liquid on the raw side 36a of the pre-filter 36 controlled.

Downstream of the branch to the control unit connection line 64 branches a main pump connection line 68 from the return line 60 and discharges into the main pump supply line 44 , In the main pump connection line 68 is a pressure control valve 70 arranged to control the fluid pressure on the consumer side of the fluid circuit 10 , The pressure control valve 70 allows fluid flow from the return line 60 to the main pump supply line 44 , In reverse flow direction locks the pressure control valve 70 ,

The main pump connection line 68 with the pressure control valve 70 is functionally parallel to the control unit connection line 64 , the control unit 66 and the pre-filter element 36 having liquid line branch.

The pressure control valve 70 is located below the return air vent valve 62 , so that upstream of the pressure control valve 70 occurring gases, in particular air, via the return-vent valve 62 , the vent section of the return line 60 and the liquid discharge 24 optimal for liquid storage 12 can be discharged.

The raw side 38a of the main filter 38 is via a vent line 72 with the return line 60 connected and opens into the vent section downstream of the return vent valve 62 , In the vent line 72 is the above-mentioned main filter vent valve 74 arranged, which is constructed as a spring-loaded check valve, and a gas discharge from the raw side 38a of the main filter 38 to the venting section of the return line 60 allowed.

From the supply line 40 further branches upstream of the inlet check valve 42 a priming pump line 76 which leads to a reversibly operable liquid pump 78 leads. In the pre-pump line 76 there is a weighted fore pump check valve 80 , with which a liquid return flow from the liquid pump 78 to the supply line 40 is prevented. From the liquid pump 78 leads a bendable fluid line 82 , which can also be referred to as a "flexible pipe", to a collection area 84 for separating liquid at the bottom of the pre-filter 36 , In fuel systems, the capture liquid is essentially water.

Between the pre-pump check valve 80 and the liquid pump 78 branches a separation liquid discharge line 86 from the backing pump line 76 and leads to a Abscheideflüssigkeitsauslass 88 the liquid filter system 16 , To the separation liquid outlet 88 is a not relevant interest drain line closed. In the separating liquid discharge pipe 86 is a spring loaded separation liquid discharge valve 90 which arranges a return flow of separating liquid to the liquid pump 78 prevented.

In the 3 is the control unit 66 shown in section. The control unit 66 comprises a valve unit 66a with which the control unit connection line 64 can be opened or closed. Furthermore, the control unit 66 a helical compression spring made of nitinol (Nitinolfeder 66b ), which by means of their shape memory as a temperature detection unit for the liquid temperature of the filter-side region of the control unit connecting line 64 serves. Instead of nitinol, a different shape memory material or a bimetal or a wax element can be used.

The valve unit 66a and the nitinoleather 66b are in a common cylindrical valve housing 92 accommodated. The valve housing 92 has an inlet opening on the front side 94 for liquid, which with that with the return line 60 connected portion of the control unit connection line 64 corresponds. The entrance opening 94 is with a valve body 96 lockable, which in a valve room 102 of the valve housing 92 to the entrance opening 94 towards and away from this is movable. To close the inlet opening 92 is a corresponding sealing surface of the valve body 96 at a valve seat around the inlet opening 94 sealingly.

In 3 is the valve unit 66a shown in the open state. The valve unit 66a is closed in the normal state, not shown below a certain liquid pressure on the consumer side and above a certain liquid temperature on the filter side. The opening pressure of the valve unit 66a is totally dependent on the liquid temperature. This is due to the spring force of Nitinolfeder 66b and a co-acting in the same direction helical compression spring made of steel (steel spring 98 ) causes. The steel spring 98 surrounds the Nitinolfeder 66b coaxial with this. The steel spring 98 but also within the Nitinolfeder 66b be arranged.

The nitinoleather 66b and the steel spring 98 are supported on the underside of the valve body 96 and at the entrance opening 94 opposite inner surface of the valve housing 92 from.

On opposite circumferential sides of the valve body 92 There are also two outlet openings 100 that with the valve room 102 are connected. The outlet openings 100 correspond via the first connection line 64 with the raw side 36a of the pre-filter 36 connected.

The nitinoleather 66b is in total in thermal contact with liquid in the section of the connecting line 64 to the raw side 36a of the pre-filter 36 and thus detects the liquid temperature in the flow. The nitinoleather 66b increases its axial extent with increasing liquid temperature and thus exerts a closing pressure on the valve body in a predetermined liquid temperature range 96 to close the valve unit 66a out, leaving no liquid from the return line 60 to the pre-filter 36 arrives. Below the predetermined flow liquid temperature, preferably 20 ° C, for example, during a cold start, takes the Nitinolfeder 66b their original axial extent, so that their share of the closing force of the valve unit 66a decreases as the liquid temperature decreases. The minimum opening pressure of the valve unit 66a is then through the steel spring 98 defined, whose spring force is substantially independent of temperature. The steel spring 98 prevents the valve unit 66a opens below the minimum opening pressure.

The below the certain flow temperature via the control unit 66 derived liquid partial flow also serves to heat the liquid in the pre-filter 36 ,

In the 4 is the pressure control valve 70 shown in section. The pressure control valve 70 has a liquid inlet 103 on that with the return line 60 connected is. To the liquid inlet 103 closes in the flow direction tapering, multi-stepped inflow 104 at. At the inflow area 104 closes a valve seat of a spring-loaded check valve 106 at. In the basic position of the check valve 106 presses a valve spring 108 a valve body 110 against the valve seat 105 and thus closes the check valve 106 , To the valve seat 105 closes downstream an annulus 112 at. The annulus 112 has an outlet opening on the peripheral side 114 for the liquid that is connected to the main pump connecting pipe 68 connected is. The inflow area 104 and the check valve 106 are in a common housing 115 arranged substantially linearly.

With the pressure control valve 70 the fluid pressure in the fluid circuit becomes 10 on the consumer side, especially in the main filter clean line 56 , the pure liquid line 18 , the fluid return line 22 and the portion of the return line 60 in front of the vent valve 62 regulated. The inflow area act here 104 and the check valve 106 functionally together, wherein by means of the inflow 104 the flow velocity in the region of the valve body 110 is reduced. With the return bleed valve 62 and the main filter bleed valve 74 is the amount of ge Dissolved air in the liquid kept as low as possible, so that the pressure control valve 70 is optimized for cavitation. With the inflow area 104 Furthermore, an emergency operation will be possible, even if the check valve 106 due to a defect, such as the breakage of the valve spring 108 no longer closes.

In the 5 is the pre-filter 36 shown in section according to a first embodiment. The pre-filter 36 has a cylindrical filter housing 116 on, in which a here not further interesting, substantially rotationally symmetrical filter element 118 is arranged. The filter element 118 separates an inlet space 120 on the raw side 36a of the pre-filter 36 close to an inner space on the Reiseite 36b , Below the filter element 118 is from this with an end plate 120 separated the collection area 84 for the separating liquid. The collection area 84 surrounding housing part can also be referred to as a "bowl". The raw side 36a is with the collection area 84 connected, so that the liquid to be transported on the raw side 36a and in the collection area 84 can distribute. On the raw side 36a separated capture liquid may be down to the bottom of the collection area 84 sink and gather there in a central depression.

In a central central tube 122 runs the bendable liquid line 82 from a terminal block 82a almost to the bottom of the collection area 84 where she is open. The bendable fluid line 82 is made of a plastic, especially PA11. The fluid line 82 Due to its flexibility, it can easily fit into the center tube 122 be inserted, for example, when changing the pre-filter 36 , In this case, the pre-filter 36 relative to the connection head 82a also tilted or tilted. The fluid line 82 can be easily exchanged.

The connection head 82a has hydraulic connections for the liquid pump 78 and electrical connections for a control electronics unit 124 the liquid filter system 16 on.

On the outside of the bendable fluid line 82 run in the axial direction two signal lines 126 in the form of metal strands to the free end of the liquid line 82 , There they are with liquid sensors 128 connected, with which the achievement of a predetermined level of Abscheideflüssigkeit in the collection area 84 can be detected.

The liquid sensors 128 can also be electrode-like from the signal lines 126 be educated.

The signal lines 126 are in the terminal block 82a via the electrical connections with the control electronics unit 124 connected. With the control electronics unit 124 can the liquid pump 78 on signals from the liquid sensors 128 be controlled so that they are the Abscheideflüssigkeit from the collection area 84 sucks.

The length of the bendable fluid line 82 is optimal for the height of the pre-filter 36 matched, leaving the muzzle at a distance from the bottom of the collection area 84 is arranged, which is optimal for the suction of the Abscheideflüssigkeit.

The liquid pump 78 is in the 6 shown. It is a gear pump that can be operated reversibly. The gear pump has two steel gears 78a whose teeth slide along ceramic-coated housing walls. The housing walls may be coated with another material, such as plastic or steel instead of ceramic. But they can also be made entirely of ceramic, plastic or steel. The teeth of the two stainless steel gears 78a interlock The sense of rotation of the stainless steel gears 78a specifies the direction of delivery. An inlet / outlet 130 the liquid pump 78 is with the backing pump line 76 connected, another inlet / outlet 132 is over the terminal block 82a with the bendable fluid line 82 connected.

Depending on the control of the liquid pump 78 with the electronic control unit 124 the conveying direction can be specified so that either separating liquid from the collecting area 84 is sucked or liquid from the backing pump line 76 the raw side 36a , respectively the collection area 84 , is pumped.

When aspirating separating liquid from the collecting area 84 is doing the backing pump return valve 80 automatically closed, so that a pressure for opening the Abscheideflüssigkeitsaustragsventils 90 in the separation liquid discharge line 86 builds. With sufficient separation liquid pressure, the separation liquid discharge valve becomes 90 opened against the spring load, so that the separating liquid from the collecting area 84 of the pre-filter 36 pumped and so on the Abscheideflüssigkeitsauslass 88 from the fluid filtration system 16 be removed.

Will the starting fluid pump 78 with the electronic control unit 124 activated for repumping liquid. This is the case, for example, if after a change of the prefilter 36 , in which still no liquid is contained. A lack of fluid can also be with the fluid Velocity Sensors 128 or another detection unit detected and to the control electronics unit 124 be transmitted. For repulping liquid, the liquid pump 78 with the electronic control unit 124 so driven that they pass over the fluid line fourteen and the priming pump line 76 Aspirate liquid and over the flexible liquid line 82 the pre-filter 36 can supply. This is the pre-pump check valve 80 automatically opened. The separation liquid discharge valve 90 is automatically closed, so that the required for Nachpumpen suction pressure in the backing pump line 76 can build and also no Abscheideflüssigkeit from Abscheideflüssikeitsauslass 88 can flow back. Once with the control electronics unit 124 it is detected that the pre-filter 36 is sufficiently filled with liquid for an operating start, the priming process is terminated by the liquid pump 78 with the electronic control unit 124 is stopped. The liquid filter system 16 is now ready for normal operation.

In normal operation, liquid is made by means of the main liquid pump 26 via the supply line 40 and the self-opening check valve 42 to the raw side 36a of the pre-filter 36 sucked.

The 7 shows the separation liquid discharge valve 90 in longitudinal section. The separation liquid discharge valve 90 has an inlet opening 90a on with the separating liquid discharge pipe 86 connected is. An outlet channel 90b extends in the Abscheideflüssigkeitsauslass 88 , which on a valve housing 90c the separation liquid discharge valve 90 is releasably attached. The inlet opening 90a is below a certain separating liquid pressure in the separating liquid discharge pipe 86 with a valve body 90d closed, with a preloaded valve spring 90e pressed against a valve seat, which is the inlet opening 90a surrounds. The separation liquid discharge valve 90 is constructed linearly overall.

As in 8th shown are the inlet check valve 42 and the fore pump check valve 80 in a common multi-part housing 129 accommodated. In the pre-pump check valve 80 this is a weighted ball valve, the inlet check valve 42 has a valve body 42 on, by means of a coil spring 42b is charged. The from the raw liquid inlet 28 incoming liquid line opens into a peripheral inlet 125 a branching chamber 127 between the inlet check valve 42 and forepump check valve 80 , In the further course, the corresponding liquid line branches are in the fore pump check valve 80 as the above-mentioned priming pump line 76 and in the inlet check valve 42 as the supply line 40 designated.

In 9 is the check / throttle valve 58 according to a first embodiment shown in a filter head 132 for the main filter 38 is installed. The main filter 38 who in 9 is also constructed according to a first embodiment is at the bottom of the filter head 132 angschraubt. The check / throttle valve 58 has a cup-shaped housing 134 on which to the main filter 38 is open. The housing 134 has a liquid side circumference 136 to which the section of the main filter clean line 56 connects to the clean fluid outlet 30 leads. In the case 134 is also a cup-shaped throttle valve piston 138 slidably disposed in the axial direction. The bottom of the throttle valve piston 138 is located on the main filter 38 facing side. On the periphery, the throttle valve piston 138 a liquid opening 140 on which in the in the 9 illustrated upper position in which the check / throttle valve 58 its minimum throttle effect, with the fluid opening 136 flees. The bottom of the throttle valve piston 138 has a receiving opening 142 for receiving a hollow connecting piece 144 on top of the front of the main filter 38 is attached. The connection piece 144 is fluid-conducting with the clean side 386 of the main filter 38 connected.

A check valve piston 146 is inside the throttle valve piston 138 slidably disposed in the axial direction relative to the latter. With the check valve piston 146 can the receiving opening 142 be closed. On the receiving opening 142 opposite side engages a preloaded coil spring 148 at the check valve piston 146 on, whose opposite side is against a housing cover 150 of the housing 134 supported. The spiral spring 148 exerts a closing force on the check valve piston 146 from and pressed against a sealing surface at a receiving opening 142 surrounding valve seat at the bottom of the throttle valve piston 138 so that the receiving opening 142 below a certain fluid pressure on the clean side 38b of the main filter 38 closed is. The check valve piston 146 also has a seal 147 against the edge of the connecting piece 144 on. The edge of the connecting piece 144 is designed as a sealing surface. The seal 147 seals in the closed position of the check valve piston 146 the interior of the throttle valve piston 138 against the clean side 38b of the main filter 38 from.

The connection piece 144 has a shoulder 152 , which are opposite the edge of the connecting piece 144 is discontinued. The shoulder 152 lies with correctly installed main filter 38 at the connecting piece. 144 facing surface of the throttle valve piston 138 fluid tight and pushes the throttle valve piston 138 against the spring force of the coil spring 148 to the housing cover 150 so that the fluid openings 136 and 140 aligned. The check / throttle valve 58 is then open in the forward direction.

When using a main filter of another type, which has no or another connection piece, which is not suitable, the throttle valve piston 138 to the housing cover 150 to move towards, or if the main filter 38 is not mounted correctly, the liquid openings overlap 136 and 140 less or not at all, allowing the flow of fluid through the main filter clean line 56 is throttled. Thus, the use of a wrong main filter or a wrong mounting can be detected. The check / throttle valve 58 thus combines a backstop for liquid from the main filter clean line 56 to the consumer 20 with the throttle function in particular for fault detection. The backstop prevents the consumer side from running empty when the consumer 20 not in operation.

In the 10 is a second embodiment of a main filter 238 shown, which is designed as a replaceable filter. In a filter housing pot 240 is an exchangeable replaceable filter element 245 arranged. The filter housing pot 240 is on one as a filter head 242 trained part of one in the 10 not otherwise shown check / throttle valve, which to the check / throttle valve 58 from the 9 otherwise similar, releasably secured. The filter head 242 forms the lid of the filter housing pot 240 , An end plate 246 of the replaceable filter element 245 lies fluid-tight on a corresponding sealing surface of the filter head 242 at. In the center of the end disk 246 is a connecting piece 244 with a collar 252 arranged, which is analogous to the connecting piece 144 of the first embodiment of the main filter 38 from the 9 interacts with the check / throttle valve. In the second embodiment, it is advantageous, for example chips, when drilling an opening for the connecting piece 244 in the filter head 242 incurred, not to the clean side 238b of the replaceable filter element 245 can reach.

In 11 is a second embodiment of a prefilter 236 shown, which is designed as a replaceable filter. In contrast to the pre-filter 36 according to the first embodiment 5 , is the filter housing 316 constructed in two parts in the second embodiment and can be opened. In the filter housing 316 is a replaceable filter element 237 arranged interchangeably. The replaceable filter element 237 has a central tube 322 , which is analogous to the central tube 122 from the first embodiment according to 5 as a recording for in the 11 not shown bendable liquid line 82 serves. The filter housing 316 is with the one opening 327 for the bendable liquid line 82 having front side 329 mounted on a filter head, not shown. The center tube 322 has at its free end outside of the filter housing 316 on the radially outer side of a circumferential seal 323 on, with which it is sealed in the radial direction against the filter head. At the front 329 Another closed seal is arranged, with which the front side 329 is sealed against a corresponding sealing surface of the filter head in the axial direction.

In 12 is a second embodiment of a check / throttle valve 58 shown. Those elements corresponding to those of the first embodiment according to 9 are similar, are provided with the same reference numerals, so that reference is made to the description of the first embodiment with respect to their description. In contrast to the first embodiment, in the second embodiment, the check / throttle valve 58 In addition, a preloaded outer coil spring 149 on, coaxial with the coil spring 148 , these and the receiving opening 142 in the bottom of the throttle valve piston 148 surrounding, runs. The outer coil spring 149 rests on one side against the housing cover 150 and on the other side against the bottom of the throttle valve piston 138 from. The outer coil spring 149 stops when the main filter is not mounted 38 the throttle valve piston 138 in its closed position.

The liquid filter system 16 or parts thereof can be used instead of a fuel circuit in a different fluid circuit, such as a water or oil circuit.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 10030324 A1 [0005]

Claims (25)

Liquid filter system ( 16 ) of a fluid circuit ( 10 ), in particular a fuel injection system with a fuel return, comprising at least one filter element ( 36 ; 236 ), a Rohflüssigkeitseinlass ( 28 ) and a liquid outlet ( 34 ), each with a liquid storage ( 12 ) are connectable, and a clean fluid outlet ( 30 ) with a consumer ( 20 ) is connectable, wherein the filter element ( 36 ; 236 ) functionally between the raw liquid inlet ( 28 ) and the clean fluid outlet ( 30 ), and a raw page ( 36a ) of the filter element ( 36 ; 236 ) corresponding to a control unit ( 66 ), which is a temperature sensing unit ( 66b ) for controlling one in the control unit ( 66 ) valve ( 66a ) depending on a liquid temperature of a liquid in the liquid circuit ( 10 ) by which the consumer ( 20 ) not removed liquid at least partially the raw side ( 36a ) of the filter element ( 36 ; 236 ) can be fed again, characterized by a liquid pump ( 78 ) at least for priming the filter element ( 36 ; 236 ) with liquid. Liquid filter system according to claim 1, characterized by a liquid return ( 32 ), with the consumer ( 20 ) connectable and corresponding to the control unit ( 66 ) connected is. Liquid filter system according to claim 1 or 2, characterized in that the liquid pump ( 78 ) functionally between the raw liquid inlet ( 28 ) and the raw side ( 36a ) of the filter element ( 36 ; 236 ) is arranged. Liquid filter system according to one of the preceding claims, characterized in that a pressure regulating means ( 70 ) for regulating the fluid pressure at least on the consumer side ( 60 ) of the fluid circuit ( 10 ), wherein the pressure control means ( 70 ) possibly downstream of the liquid reflux ( 32 ) is arranged. Liquid filter system according to one of the preceding claims, characterized in that the temperature detection unit ( 66b ) is designed so that the valve ( 66a ) depending on the liquid temperature of the liquid on the raw side ( 36a ) of the filter element ( 36 ; 236 ) or optionally a time-averaged mixing temperature from a liquid return from the consumer side can control. Liquid filter system according to one of the preceding claims, characterized in that the temperature detection unit is a spring element ( 66b ) comprises a shape memory material, in particular nitinol, or a bimetal or a wax element. Liquid filter system according to one of the preceding claims, characterized in that the liquid pump ( 78 ) reversibly operable, in particular a gear pump or a diaphragm pump, is an inlet / outlet ( 132 ) of the liquid pump ( 78 ) for liquid with a collecting area ( 84 ) for separating liquid on the raw side ( 36a ) of the filter element ( 36 ; 236 ), another inlet / outlet ( 130 ) of the liquid pump ( 78 ) connected to the raw fluid inlet ( 28 ) is functionally in communication, in addition with a Abscheideflüssigkeitsauslass ( 88 ) of the liquid filter system ( 16 ), and control means ( 80 . 90 ) are provided with which, depending on the liquid conveying direction of the liquid pump ( 78 ) optionally the connection of the liquid pump ( 78 ) to the raw fluid inlet ( 28 ) or to the separating liquid outlet ( 88 ) can be opened. Liquid filter system according to claim 7, characterized in that the control means comprise at least two non-return valves ( 80 . 90 ), which functionally between the liquid pump ( 78 ) and the raw fluid inlet ( 28 ) and the liquid pump ( 78 ) and the Abscheideflüssigkeitsauslass ( 88 ) are arranged such that either the connection to the Rohflüssigkeitseinlass ( 28 ) or the connection to the separating liquid outlet ( 88 ) is open. Liquid filter system according to one of the preceding claims, characterized by control electronics ( 124 ) for controlling at least the liquid pump ( 78 ) and a bendable fluid line ( 82 ) coming from the liquid pump ( 78 ) to a collection area ( 84 ) for separating liquid on the raw side ( 36a ) of the filter element ( 36 ; 236 ), wherein the bendable liquid line ( 82 ) removable in the filter element ( 36 ; 236 ) runs. Liquid filter system according to claim 9, characterized in that the bendable liquid line ( 82 ) in a collection area ( 84 ) assigned to section sensors ( 128 ), in particular electrodes, for detecting separation liquid and signal lines ( 126 ) from the sensors ( 128 ) to the control electronics ( 124 ) along the bendable fluid line ( 82 ). Liquid filter system according to claim 4, characterized in that the pressure regulating means ( 70 ) a flow area tapering in the flow direction ( 104 ) for the liquid and a subsequent spring-loaded valve ( 106 ) having. Liquid filter system according to one of the preceding claims, characterized in that funk between the clean side ( 36b ) of the at least one filter element ( 36 ; 236 ), in particular a prefilter element, and the liquid outlet ( 34 ) a further filter element, in particular a main filter element ( 38 ; 238 ) is arranged. Liquid filter system according to claim 12, characterized in that the raw side ( 38a ) of the further filter element ( 38 ; 238 ) with the clean side ( 36b ) of the at least one filter element ( 36 ; 236 ) and possibly with the pressure control means ( 70 ) is functionally connected and the clean side ( 38b ; 238b ) of the further filter element ( 38 ; 238 ) with the clean liquid outlet ( 30 ) is functionally connected. Liquid filter system according to one of the preceding claims, in particular according to claim 12 or 13, characterized in that the raw side ( 36a ) of the at least one filter element ( 36 ; 236 ) or possibly the raw side ( 38a ) of the further filter element ( 38 ; 238 ) via a vent valve ( 74 ) with the liquid outlet ( 34 ) is functionally connected. Liquid filter system according to one of the preceding claims, in particular according to one of claims 12 to 14, characterized in that the clean side ( 36b ) of the at least one filter element ( 36 ; 236 ) or possibly the clean side ( 38b ; 238b ) of the further filter element ( 38b ; 238b ) via a check / throttle valve ( 58 ) with the clean liquid outlet ( 30 ) is functionally connected. Liquid filter system according to one of the preceding claims, characterized in that in the liquid circuit ( 10 ), in particular downstream of the at least one filter element ( 36 ; 236 ), a main liquid pump ( 26 ) is arranged. Liquid filter system according to claim 16, characterized in that the main liquid pump ( 26 ) not in the liquid filter system ( 16 ) and the liquid filter system ( 16 ) corresponding connections ( 46 . 52 ) for the main liquid pump ( 26 ) having. Liquid filter system according to claim 2, characterized in that functionally between the liquid return ( 32 ) and the liquid outlet ( 34 ) a vent valve ( 62 ) is arranged. Liquid filter system according to claims 4 and 18, characterized in that the vent valve ( 62 ) spatially above the pressure control means ( 70 ) is arranged. Liquid filter system according to one of previous claims, characterized in that it as Module is constructed. Liquid filter system according to one of the preceding claims, characterized in that the filter element ( 236 ) and / or optionally the further filter element ( 238 ) is a replaceable filter. Bendable fluid line ( 82 ) a liquid filter system ( 16 ) in particular according to claim 9 or 10, characterized by sensors ( 128 ), in particular electrodes, for detecting separation liquid and signal lines ( 126 ) from the sensors ( 128 ) to a control electronics ( 124 ), along the bendable liquid line ( 82 ). Filter element ( 36 ; 236 ) a liquid filter system ( 16 ) in particular according to one of claims 9 or 10, characterized by a receiving element, in particular a central tube ( 122 ; 322 ), for a bendable fluid line ( 82 ) in particular according to claim 22. Check valve / throttle valve ( 58 ) a liquid filter system ( 16 ) in particular according to claim 15, characterized in that it is provided with a filter element ( 38 ; 238 ) can be mechanically connected, wherein an actuating element ( 144 ) of the filter element ( 38 ; 238 ) with a special geometry ( 152 ) with an attack area ( 142 ) of a throttle element ( 138 ) of the check / throttle valve ( 58 ) can cooperate with a corresponding counter-geometry such that the check / throttle valve ( 58 ) in its by a non-return element ( 146 ) of the check / throttle valve ( 58 ) can be flowed through with predetermined passage direction fluid. Filter element ( 38 ; 238 ) a liquid filter system ( 16 ) in particular according to claim 15, characterized by an actuating element ( 144 ) with a special geometry ( 152 ) with an attack area ( 142 ) of a throttle element ( 138 ) of a check / throttle valve ( 58 ) can interact in particular according to claim 24 with a corresponding counter-geometry such that the throttle element ( 138 ) assumes an opening state.

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