DE102019125209A1 - Liquid filter - Google Patents

Abstract

The invention relates to a liquid filter (10) with a filter housing (12) and a filter insert (14) which is arranged axially movable within the filter housing (12) and has filter material (34), the filter material (34) from a raw side (36) ) a liquid to be filtered can flow through to a clean side (38) of the liquid filter (10), an axial movement of the filter insert (14) being able to be caused by a pressure difference between the raw side (36) and the clean side (38).

Description

The invention relates to a liquid filter with a filter housing and a filter insert, which is arranged axially movable within the filter housing and has filter material, the filter material being able to be flowed through by a liquid to be filtered from a raw side to a clean side of the liquid filter.

The filter material of a filter insert experiences aging with increasing service life, which can be attributed in particular to the contamination of the filter material. For this reason, liquid filters have hitherto been regularly serviced, with the filter insert having to be replaced or the filter material of the filter insert cleaned as part of the maintenance. If the required maintenance is not carried out or is carried out incorrectly, the liquid throughput through the liquid filter can be significantly impaired, for example.

In the case of fuel filters, this can lead to a noticeable reduction in engine performance and even insufficient fuel supply to run the engine. In the case of oil filters, the aging of the filter insert often leads to the opening of a bypass or bypass valve, as a result of which the liquid filter loses its filter function. This can lead to considerable damage to the unit in which the liquid filter is used.

To avoid the aging-related scenarios outlined above, filter cartridges are often replaced too early in practice, so that the filter cartridges are not used until the end of their service life. The maximum operating time of filter cartridges is therefore regularly not exhausted, which results in considerable savings potential. In the case of commercial vehicles in particular, the exhaustion of the service life of corresponding filter inserts would lead to a considerable reduction in maintenance costs.

Furthermore, fixed maintenance intervals are specified for the liquid filters used in practice, which, for example, considerably limit the freedom of action of operators of large vehicle fleets.

In order to counter these problems, liquid filters with a wear indicator are already known in the prior art, in which a user can read the state of wear on the liquid filter. From the pamphlet US 2008/0053879 A1 For example, a liquid filter is known in which an axial movement of the filter insert is triggered by an increase in pressure on the raw side of the liquid filter. The axial movement of the filter insert is due to the pressure difference between the liquid pressure on the raw side and the ambient pressure.

The problem with these and other known solutions is that the pressure on the clean side of the liquid filter has no influence on the axial displacement of the filter insert, so that the pressure level on the clean side is not taken into account when determining the degree of contamination of the filter insert.

The object on which the invention is based is therefore to provide a liquid filter in which the aging or the state of contamination of the filter material can be monitored via an axial movement of the filter insert, with both the pressure on the raw side and the pressure on the clean side of the Liquid filter is taken into account.

The object is achieved by a liquid filter of the type mentioned at the beginning, wherein an axial movement of the filter insert of the liquid filter according to the invention can be caused by a pressure difference between the raw side and the clean side.

The invention makes use of the knowledge that the pressure difference between the raw side and the clean side increases with increasing contamination of the filter material due to a decreasing permeability of the filter material. The axial movement of the filter insert, which is dependent on the pressure difference between the raw side and the clean side of the liquid filter, can be used to monitor the aging or the state of contamination of the filter material. As a result of the monitoring, the filter insert can be used until the end of its service life, so that replacing the filter insert too early is effectively avoided. By utilizing the entire service life of the filter insert, the maintenance costs of commercial vehicles can be reduced considerably. In addition, flexible maintenance intervals that are adapted to the level of contamination can be implemented.

The liquid filter according to the invention is thus designed in such a way that when the differential pressure increases between the raw side and the clean side, the filter insert is moved out of its rest position in the axial direction. The filter insert has, for example, two opposite end disks, the filter material being arranged between the end disks. Due to the pressure difference between the raw side and the clean side of the liquid filter, there are axial forces on the end plates, which are oriented in opposite directions. Since an end disk on the If the clean side has a discharge opening for the filtered liquid, the axial forces acting on the end disks differ so that they do not cancel out or compensate one another. The discharge opening is located, for example, in the inner dome area of an end disk. Due to the different axial forces on the end plates, a deflection force remains, which causes an axial movement of the filter insert. The remaining deflection force increases as the pressure difference between the raw side and the clean side of the liquid filter increases. The liquid filter can be, for example, a fuel filter or an oil filter of a vehicle, in particular a commercial vehicle.

In a preferred embodiment, the liquid filter according to the invention has a spring element which counteracts the axial movement of the filter insert. The spring element can preferably be compressed and / or extended apart by an axial movement of the filter insert. The spring element is, for example, a helical spring. The spring element is preferably arranged in the filter housing of the liquid filter. The spring element absorbs the axial force acting on the filter insert, so that an axial deflection of the filter insert that is dependent on the spring properties and the pressure difference between the raw side and the clean side is implemented. The degree of contamination of the filter material and thus the state of aging of the filter insert can be determined via the extent of the axial deflection of the filter insert. A small axial deflection of the filter insert indicates a low level of contamination of the filter material. A strong axial deflection of the filter insert indicates that the filter material is very dirty.

In another preferred embodiment, the liquid filter according to the invention has a detection device, in particular an electrical one, by means of which a position and / or the axial movement of the filter insert can be detected and / or determined. The detection device can comprise a proximity sensor or a distance sensor, by means of which the approach of the filter insert or the distance to the filter insert can be detected and / or determined. The position and / or the axial movement of the filter insert can be detected capacitively and / or inductively by the detection device, for example. The detection device can be set up, for example, to detect a change position of the filter insert, which indicates a state of contamination which makes it necessary to change the filter insert. Changing a filter element is usually necessary when the filter element has reached an end-of-lifetime status. This state is typically considered to have been reached when the state of contamination of the filter insert is just sufficient for a certain operating time serving as safety without impairment. In the case of parallel operation of several filters, however, the condition can also be selected in such a way that the contamination condition would already impair operation of the filter. The change position of the filter insert can be an end position, so that no axial movement of the filter insert beyond the change position is possible. The detection device can have a contacting mechanism by means of which an electrically conductive permanent contact is established when the filter insert assumes a specific position, for example the changing position. An axial stop for the filter insert is preferably implemented by the contacting mechanism, so that no further axial displacement of the filter insert beyond the specific position is possible after the permanent contact has been established.

In addition, a liquid filter according to the invention is preferred which has a display device. The state of contamination of the filter material based on the axial deflection of the filter insert can be optically displayed by means of the display device. The display device of the liquid filter thus serves as an aging indicator for the filter insert. Since the axial deflection of the filter element depends on the pressure difference between the raw side and the clean side of the liquid filter, the contamination status of the filter material that can be visually indicated by the display device is also based on the pressure difference between the raw side and the clean side of the liquid filter.

In another preferred embodiment of the liquid filter according to the invention, the display device has a latching mechanism by means of which a contamination state remains optically displayed after a pressure difference between the raw side and the clean side has been resolved. The pressure difference between the raw side and the clean side of the liquid filter is dissolved, for example, when the delivery of the liquid to be filtered is interrupted. A corresponding interruption of the delivery occurs, for example, when a delivery pump is switched off, it being possible for the delivery pump to be switched off when an engine is switched off. The contamination status can thus also be read off when the delivery of the liquid to be filtered is interrupted, for example because the engine of the vehicle in which the liquid filter is installed has been switched off. The locking mechanism can have several locking steps. The display of the contamination status is maintained after the pressure difference between the raw side and the clean side has been resolved. Alternatively, the locking mechanism can also be designed continuously.

In a further development of the liquid filter according to the invention, the display device has a visor body which is designed to cover a display body of the display device, the degree to which the display body is covered by the visor body is dependent on the axial deflection of the filter insert. The visor body and the display body are therefore movable relative to one another in the axial direction. The visor body and the display body preferably have different colors, so that the degree of obscuration of the display body by the visor body can be clearly perceived. The diaphragm body is preferably designed as a sleeve diaphragm. The display body is preferably designed as a colored display sleeve. The visor body designed as a sleeve diaphragm and the display body embodied as a display sleeve are preferably arranged coaxially to one another.

In addition, a liquid filter according to the invention is preferred in which the diaphragm body is coupled to the filter insert in such a way that the diaphragm body is moved in the axial direction by the filter insert when the filter insert is axially deflected. The coupling of the diaphragm body and the filter insert preferably has an axial play which prevents the diaphragm body from moving back through the filter insert in the event of an opposing axial movement of the filter insert after a pressure difference between the raw side and the clean side has been resolved. If the pressure difference between the raw side and the clean side is dissolved, for example due to an interruption in the delivery of liquid, the filter insert moves back into its rest position, with the diaphragm body remaining in its axially deflected position. The diaphragm body preferably has a sliding surface, in particular a circumferential sliding surface, on which a fastening section of the filter insert slides when the axial play is used. The diaphragm body is fastened, for example, to an end disk of the filter insert, the fastening having the axial play. The diaphragm body is preferably clipped into the filter insert. Alternatively, however, a different fastening or a diaphragm formed in one piece on the filter insert is also possible. The display body is attached, for example, to the filter housing of the liquid filter so that it cannot be deflected by an axial movement of the filter insert and / or the visor body. In another embodiment, the display body can also be axially movable and axially deflectable by an axial movement of the filter insert and / or the diaphragm body. Alternatively, it is also possible for the display body to be attached to the filter insert and the diaphragm body to be attached to the filter housing. In this case, the display body is moved with the filter insert. With a corresponding configuration of the filter housing, a diaphragm body can also be omitted or formed by the filter housing.

In a further preferred embodiment of the liquid filter according to the invention, the visor body and the display body are components of the latching mechanism, the visor body and the display body having corresponding latching sections which can be brought into engagement in different locking stages via a relative movement of the visor body and the display body in the axial direction. Disengaging the latching sections requires increased effort so that a latching effect is implemented. If the pressure difference between the raw side and the clean side is dissolved, for example if the liquid feed is interrupted, the corresponding latching sections of the visor body and the display body remain in engagement, so that the degree of concealment that exists during operation even after the pressure difference between the raw side and the clean side has been dissolved is retained. If the filter insert needs to be changed, the increased effort required to disengage the latching sections can be applied manually to the visor body or the display body, so that the latching mechanism is manually reset to its original state, this state indicating an unpolluted filter material .

In an advantageous development of the liquid filter according to the invention, the display device comprises a viewing window in the filter housing, through which the degree of obscuration of the display body by the visor body is optically perceptible, in particular optically readable. The degree of obscuration by the viewing window can preferably be visually perceived by a person from the outside. On the viewing window or markings can be arranged in the vicinity of the viewing window, which mark different degrees of covering of the display body by the visor body. The contamination status of the filter material can then be read from the markings.

In addition, a liquid filter according to the invention is preferred which has a water separation device for separating water from the liquid. The water separation device has a collection chamber for the separated water. The filling level of the collecting chamber can be visually perceived, in particular optically read, via the viewing window. The viewing window thus allows a combined display of the aging condition of the filter insert and the filling level of the collecting chamber. The diaphragm body and / or the display body are preferably arranged in the collecting chamber. Markings which indicate different filling levels of the collecting chamber can be arranged on the viewing window or in the vicinity of the viewing window. The filling level of the collecting chamber can thus be read from the markings.

In another embodiment of the liquid filter according to the invention, the display device has a temperature-dependent locking mechanism, by means of which a relative movement between the display body and the diaphragm body can be prevented when the filter insert is axially deflected. During a cold start, the temperature-related increased viscosity of the liquid to be filtered temporarily leads to a comparatively high pressure difference between the raw side and the clean side of the liquid filter. So that the display device does not display the contamination status incorrectly and / or the locking mechanism is unintentionally adjusted during a cold start, a relative movement between the display body and the visor body in the event of an axial deflection of the filter element during a cold start must be fundamentally prevented. As soon as the liquid is in the operating temperature range and thus has a reduced viscosity compared to the cold start state, the locking mechanism releases the relative movement between the display body and the diaphragm body again when the filter insert is axially deflected. The function of the display device is thus restored as soon as the liquid to be filtered has reached an operating temperature. Alternatively, the relative movement of the filter insert itself can also be prevented by a temperature-controlled locking mechanism at cold temperatures.

In another preferred embodiment of the liquid filter according to the invention, the display body is axially movable, the diaphragm body exerting a drag force on the display body when the filter insert is axially deflected and the display body is controlled by a temperature-controlled actuator, such as a retaining spring with temperature-dependent spring properties, an expansion element or a bimetal element , is held in a rest position until the entrainment force exceeds the holding force of the retaining spring holding the display body in the rest position. The actuator is preferably a retaining spring and part of the temperature-dependent locking mechanism. Depending on the spring properties of the retaining spring, an axial deflection of the filter insert results either in a common axial deflection of the display body and the diaphragm body or in a relative movement of the display body and the diaphragm body in the axial direction. If there is a common axial movement of the display body and the visor body, the degree to which the display body is covered by the visor body is not changed. If there is a relative movement of the display body and the visor body in the axial direction, the degree to which the display body is covered by the visor body is changed. Whether there is a relative movement between the display body and the visor body is therefore dependent on the temperature of the retaining spring. The axial movement of the display body and visor body during a cold start can thus be avoided, so that there is no false indication of the state of contamination and / or incorrect actuation of the locking mechanism due to the increased viscosity of the liquid to be filtered during a cold start. An increase in the temperature of the liquid to be filtered leads to an increase in temperature at the retaining spring, so that the spring properties of the retaining spring are changed in such a way that a relative movement of the display body and the diaphragm body in the axial direction is possible again.

In addition, a liquid filter according to the invention is advantageous in which the retaining spring is formed from a shape memory alloy. At high temperatures, the shape memory alloy is preferably austenitic. At low temperatures, the shape memory alloy is preferably martensitic. At high temperatures, the retaining spring is much more rigid than at low temperatures. At low temperatures, the retaining force of the retaining spring is therefore comparatively small. Thus, at low temperatures, there is a common axial movement of the display body and the visor body, a relative movement of the display body and the visor body in the axial direction being prevented. At high temperatures, the holding force of the holding spring is comparatively great. At high temperatures, a relative movement between the display body and the visor body is again possible in the axial direction.

A liquid filter according to the invention is also advantageous in which the display device has a locking body which is to be moved from a locked position into a release position in order to enable the filter insert to be coupled to the display device. The filter insert preferably has an unlocking element, by means of which the blocking body can be moved from the blocking position into the release position. Shoring protection is implemented via the blocking body, by means of which the installation of unsuitable filter inserts is prevented. The locking body is acted upon by a return spring with a restoring force which holds the locking body in the locking position. The return spring is designed to bring the locking body from the release position back into the locking position when the locking body has been deflected into the release position. When the locking body is in the locking position, the coupling of the filter element with the Display device not possible. When the unlocking element is arranged on the filter insert, the unlocking element can be brought into abutment with the locking body during the coupling process, so that the locking body is moved from the locking position to the unlocking position during the coupling process, thus enabling the filter insert to be coupled to the display device .

A liquid filter according to the invention is also advantageous in which the blocking body in the blocking position prevents elastic deformation of a material section of the display device by the filter insert, which is necessary for coupling the filter insert to the display device. The blocking body is preferably located in the blocking position in an area which is required by the material section of the display device for deformation. As long as the locking body is in this area, deformation of the material section is therefore not possible. In the release position, the blocking body preferably releases the elastic deformation of the material section of the display device by the filter insert, which is necessary for coupling the filter insert to the display device. This is preferably done in that the area required for the deformation is no longer occupied by the blocking element.

• 1 ein Ausführungsbeispiel des erfindungsgemäßen Flüssigkeitsfilters in einer perspektivischen Darstellung;
• 2 einen erfindungsgemäßen Flüssigkeitsfilter mit einem nichtausgelenkten Filtereinsatz in einer seitlichen Schnittdarstellung;
• 3 einzelne Bestandteile des in der 2 abgebildeten Flüssigkeitsfilters in einer perspektivischen Explosionsdarstellung;
• 4 einen Abschnitt des in der 2 abgebildeten Flüssigkeitsfilters in einer perspektivischen Schnittdarstellung;
• 5 einen Abschnitt des in der 2 abgebildeten Flüssigkeitsfilters in einer seitlichen Schnittdarstellung;
• 6 einen Abschnitt des in der 2 abgebildeten Flüssigkeitsfilters in einer weiteren seitlichen Schnittdarstellung;
• 7 den in der 2 dargestellten Flüssigkeitsfilter mit einem axial ausgelenkten Filtereinsatz in einer seitlichen Schnittdarstellung;
• 8 einen Abschnitt des in der 7 abgebildeten Flüssigkeitsfilters in einer seitlichen Schnittdarstellung;
• 9 einen Abschnitt des in der 7 abgebildeten Flüssigkeitsfilters in einer weiteren seitlichen Schnittdarstellung;
• 10 einen Abschnitt eines erfindungsgemäßen Flüssigkeitsfilters mit einem Sperrmechanismus in zwei unterschiedlichen Zuständen während eines Kaltstarts in einer seitlichen Schnittdarstellung;
• 11 einen Abschnitt des in der 10 abgebildeten Flüssigkeitsfilters in zwei unterschiedlichen Alterungszuständen in einer seitlichen Sch nittdarstell u ng;
• 12 einen Teilbereich eines Filtergehäuses eines erfindungsgemäßen Flüssigkeitsfilters in einer Seitenansicht;
• 13 einzelne Bestandteile eines erfindungsgemäßen Flüssigkeitsfilters mit einem Verbauschutz in einem ersten Montagezustand in einer Schnittdarstellung;
• 14 die in der 13 abgebildeten Teile eines erfindungsgemäßen Flüssigkeitsfilters in einem zweiten Montagezustand in einer Schnittdarstellung; und
• 15 die in der 13 abgebildeten Teile eines erfindungsgemäßen Flüssigkeitsfilters in einem dritten Montagezustand in einer Schnittdarstellung.

Preferred embodiments of the invention are explained and described in more detail below with reference to the accompanying drawings. Show:

• 1 an embodiment of the liquid filter according to the invention in a perspective view;
• 2 a liquid filter according to the invention with a non-deflected filter insert in a lateral sectional view;
• 3rd individual components of the 2 liquid filter shown in a perspective exploded view;
• 4th a section of the 2 liquid filter shown in a perspective sectional view;
• 5 a section of the 2 liquid filter shown in a side sectional view;
• 6th a section of the 2 liquid filter shown in a further lateral sectional view;
• 7th in the 2 shown liquid filter with an axially deflected filter insert in a lateral sectional view;
• 8th a section of the 7th liquid filter shown in a side sectional view;
• 9 a section of the 7th liquid filter shown in a further lateral sectional view;
• 10 a section of a liquid filter according to the invention with a locking mechanism in two different states during a cold start in a sectional side view;
• 11 a section of the 10 liquid filter shown in two different aging conditions in a lateral sectional representation;
• 12th a partial area of a filter housing of a liquid filter according to the invention in a side view;
• 13th individual components of a liquid filter according to the invention with an installation protection in a first assembly state in a sectional view;
• 14th those in the 13th depicted parts of a liquid filter according to the invention in a second assembly state in a sectional view; and
• 15th those in the 13th depicted parts of a liquid filter according to the invention in a third assembly state in a sectional view.

The 1 shows a liquid filter designed as a fuel filter 10 . The liquid filter 10 includes a filter housing 12th , being inside the filter housing 12th a filter insert 14th (hidden) is arranged. The filter housing 12th comprises a substantially cylindrical portion 16a and a cup-shaped portion 16b . The sub-area 16a is with a base 30th screwed.

The liquid filter 10 has a display device 18th on, by means of which the state of contamination of a filter material 34 of the filter insert 14th can be visually displayed. The display device 18th thus serves as an aging indicator for the filter insert 14th . The display device 18th includes a display body 22nd and a visor body 24 . The visor body 24 is set up to the display body 22nd depending on the level of contamination of the filter material 34 of the filter insert 14th to cover up. The degree of obscuration of the display body 22nd through the visor body 24 is therefore the aging condition of the filter insert 14th pending.

In the sub-area 16b of the filter housing 12th there are viewing windows 20a , 20b . Through the Viewing window 20a , 20b is the degree of obscuration of the display body 22nd through the visor body 24 optically readable. In the vicinity of the viewing window 20b are markings 78a-78d arranged, which different degrees of obscuration of the display body 22nd through the visor body 24 mark. About the markings 78a-78d can thus reduce the level of contamination of the filter material 34 of the filter insert 14th can be read.

Furthermore, the liquid filter 10 a water separating device for separating water from the liquid to be filtered, the water separating device having a collecting chamber 88 for the separated water. The level of the collection chamber 88 is about the viewing window 20a , 20b optically readable. In the vicinity of the viewing window 20b are markings 26a-26c arranged, which different fill levels of the collection chamber 88 mark. About the markings 26a-26c can thus determine the filling level of the collecting chamber 88 can be read.

An outlet opening of the filter housing 12th of the liquid filter 10 is by means of a closure element 28 locked. The closure element 28 can be used to remove the water that is in the collection chamber 88 has accumulated, to be resolved.

The 2 shows that the base 30th and the sub-area 16a of the filter housing 12th via threaded sections 32a , 32b are screwed together. Inside the filter housing 12th is the filter insert 14th arranged. The filter insert 14th is inside the filter housing 12th axially movable and has a filter material 34 on. The filter material 34 is of a liquid to be filtered from a raw side 36 to a clean side 38 of the liquid filter 10 permeable. An axial movement of the filter element 14th is caused by a pressure difference between the raw side 36 and the clean side 38 caused. The pressure difference between the raw side 36 and the clean side 38 increases due to a decreasing permeability of the filter material 34 with increasing contamination of the filter material 34 at.

The filter insert 14th has a support structure 40 on, the support structure 40 a lower end disk 44a and an upper end plate 44b includes. Between the end caps 44a , 44b there is an interior dome 42 the support structure 40 . The inner dome 42 is from the filter material 34 surrounded, the filter material 34 between the end plates 44a , 44b is arranged. Due to the pressure difference between the raw side 36 and the clean side 38 result at the end plates 44a , 44b during operation of the liquid filter 10 Axial forces directed in opposite directions. Because the end disk 44b on the clean side 38 has a discharge opening for the filtered liquid, those on the end plates differ 44a , 44b acting axial forces so that there is no force compensation. The discharge opening is located in the inner dome area of the end plate 44b and is with the exhaust ducts 58 , 60 connected.

In the area of the base 30th is inside the filter housing 12th a spring element 56 arranged, which of the axial movement of the filter element 14th counteracts. The spring element 56 is caused by an upward movement of the filter element 14th , which is caused by the pressure difference between the raw side 36 and the clean side 38 of the liquid filter 10 is caused, compressed. When the pressure difference between the raw side 36 and the clean side 38 is dissolved, for example due to an interruption in the flow of liquid, the filter insert 14th from the spring element 56 pushed back into the starting position. The filter insert is in the starting position 14th in a rest position in which support elements 64a-64d , which on the end plate 44a are arranged in contact with a support surface 66 stand. The support surface 66 thus serves as an axial stop for the filter insert 14th , which is the rest position of the filter element 14th pretends.

The spring element 56 takes the on the filter insert 14th acting on the axial force, so that one of the spring properties of the spring element 56 and the pressure difference between the raw side 36 and the clean side 38 dependent axial deflection of the filter insert 14th is possible. The extent of the axial deflection of the filter element 14th depends on the degree of contamination of the filter material 34 and thus on the aging condition of the filter insert 14th dependent. If the filter material is slightly soiled 34 there is no or only a slight axial deflection of the filter insert 14th . If the filter material is very dirty 34 there is a strong axial deflection of the filter insert 14th .

The liquid filter 10 may have an electrical detection device, not shown, by means of which it can be determined when the filter insert 14th takes a change position. If the filter element 14th is in the change position, this is an indication that the filter element needs to be changed 14th is required. The change position is an upwardly deflected end position of the filter insert 14th . If in the liquid filter 10 a water sensor 76 is provided (see below), the electrical detection device can advantageously be accommodated in its vicinity so that cabling can run adjacent.

The 3rd shows the display device 18th of the liquid filter 10 in detail. By means of the display device 18th is one on the axial deflection of the filter insert 14th based contamination status of the filter material 34 visually displayable. The display device 18th comprises a diaphragm body designed as a sleeve diaphragm 24 and a display body designed as a colored display sleeve 22nd . The visor body 24 and the display body 22nd are movable relative to one another in the axial direction and have different colors. The visor body 24 is set up to the display body 22nd to obscure, the degree of obscuration of the display body 22nd through the visor body 24 from the axial deflection of the filter insert 14th is dependent. The display body can also comprise several colors, so that different colors can be seen depending on the visibility of the body.

The visor body 24 is on the end plate 44a attached. The filter insert 14th has a fastening portion 52 on, with the visor body 24 in the fastening section 52 of the filter insert 14th is clipped. The visor body 24 has a sliding surface 50 on which the fastening section 52 of the filter insert 14th can slide along.

The 4th to 6th show that the fastening section 52 an inwardly directed protrusion of material 90 having, which with an outwardly directed material projection 92 of the visor body 24 is engageable. About the material protrusions 90 , 92 is the visor body 24 such with the filter insert 14th coupled that the visor body 24 with an axial deflection of the filter insert 14th from the filter insert 14th is moved in the axial direction, the coupling of the visor body 24 and the filter insert 14th has an axial play which causes the visor body to move back 24 through the filter insert 14th with an opposite axial movement of the filter insert 14th after dissolving a pressure difference between the raw side 36 and the clean side 38 prevented. When the axial play is used, the inwardly directed material projection slides 90 of the fastening section 52 on the sliding surface 50 of the visor body 24 along.

The display device 18th also has a locking mechanism 62a , 62b on, by means of which a state of contamination after triggering a pressure difference between the raw side 36 and the clean side 38 remains visually displayed. The state of contamination can be due to the locking mechanism 62a , 62b can also be read when the delivery of the liquid to be filtered is interrupted, for example because the engine of the vehicle in which the liquid filter is 10 is installed, is turned off. The locking mechanism 62a , 62b has several locking steps. The multiple locking steps are on the display body via multiple locking grooves running in the circumferential direction 22nd implemented, wherein the locking grooves are arranged axially spaced from one another. The material advantage 62b on the visor body 24 can due to the elastic deformability of the material webs on which the locking grooves 62a are arranged, engaged and disengaged from the different locking grooves 62a to be brought. Due to the locking mechanism 62a , 62b the contamination status is displayed in stages. Via a relative movement of the visor body 24 and the display body 22nd Different detent levels are set in the axial direction. For disengaging the latching sections of the visor body 24 and the display body 22nd an increased effort is required so that a locking effect is implemented. The illustrations also show that the closure element 28 into a lock receptacle 46 is screwed in. The lock mount 46 is in turn in an inner shell 48 screwed in. By means of a circumferential O-ring seal 54 becomes the filter housing 12th opposite the inner shell 48 sealed.

The display body 22nd is attached to the lock holder via a clip connection 46 attached. The visor body 24 shows the material protrusion on its 62b having inner tube on outward wings, which form an end stop and a complete release of the visor body 24 from the display body 22nd prevent.

The 7th to 9 show the liquid filter 10 with dirty filter material 34 . Inside the base 30th there is an inlet port 68 through which the liquid to be filtered enters the filter housing 12th can be initiated.

Due to the pollution of the filter material 34 is the permeability of the filter material 34 for the liquid to be filtered is reduced, resulting in an increased pressure difference between the raw side 36 and the clean side 38 results.

Due to the increase in differential pressure between the raw side 36 and the clean side 38 is the filter insert 14th has been moved upward out of the rest position in the axial direction. Due to the axial deflection of the filter insert 14th became the visor body 24 through the filter insert 14th taken axially upwards, so that the degree of obscuration of the display body 22nd through the visor body 24 was reduced. By the outward movement of the visor body 24 is now a lower section of the display body 22nd no longer covered. The concealed state can be viewed by a user through a viewing window 20a , 20b can be read, so that there is a change in differential pressure between the raw side 36 and the clean side 38 based wear indicator is implemented.

Due to the axial deflection of the visor body 24 were several rest stops the Locking mechanism 62a , 62b drive through. The material projection is in the state shown 62b in engagement with the uppermost locking groove so that the last locking position is reached.

When changing the filter insert 14th is the visor body 24 manually push back down so that the locking mechanism 62a , 62b is postponed. After resetting the locking mechanism 62a , 62b can change the aging condition of a new filter element 14th monitored again.

The 10 and 11 show a liquid filter 10 , in which the display device 18th a temperature-dependent locking mechanism 80 having. The locking mechanism 80 prevents an incorrect indication of the contamination status by the display device 18th during a cold start. The locking mechanism is for this purpose 80 set up a relative movement between the display body 22nd and the visor body 24 with an axial deflection of the filter insert 14th to prevent during a cold start.

The cold start situation is in the 10 shown. During a cold start, the temperature-related high viscosity of the liquid to be filtered initially results in a comparatively high pressure difference between the raw side 36 and the clean side 38 so that an axial deflection of the filter insert 14th is caused.

In the embodiment shown, the display body is 22nd axially movable, the diaphragm body 24 if the filter insert is deflected 14th a drag force on the display body 22nd exercises. The display body 22nd is held by a retaining spring 70 held in a rest position until the entrainment force affects the display body 22nd holding force of the holding spring in the rest position 70 exceeds. The retaining spring 70 is between a stationary or immobile contact surface 72 and one on the display body 22nd arranged contact surface 74 positioned. The retaining spring 70 is made from a shape memory alloy and thus has temperature-dependent spring properties. In the cold start situation, i.e. at low temperatures, the holding force is the holding spring 70 comparatively small. The drag force that the visor body 24 with an axial deflection of the filter insert 14th on the display body 22nd exercises is greater than the holding force of the retaining spring at low temperatures 70 . Thus, at low temperatures, there is a common axial movement of the display body 22nd and visor body 24 , causing an adjustment of the locking mechanism 62a , 62b the display device 18th is avoided in the cold start situation. During the common axial movement of the display body 22nd and the visor body 24 becomes the retaining spring 70 compressed.

The 11 shows an axial deflection of the filter insert due to wear 14th . At higher temperatures, i.e. in the normal operating state of the liquid filter 10 , is the holding force of the holding spring 70 comparatively large. At high temperatures, the display body will 22nd by the retaining spring 70 consequently held in the rest position, so that a relative movement between the display body 22nd and the visor body 24 due to an axial movement of the filter element 14th is possible.

Furthermore, the illustrated liquid filter 10 a water sensor 76 on, by means of which an electrical signal can be generated to monitor the water separated from the liquid to be filtered.

The 12th shows a partial area 16b a filter housing 12th , within which a viewing window 20a is positioned. The viewing window 20a allows a combined display of the aging condition of the filter insert 14th and the filling level of a collecting chamber 88 a water separator of the liquid filter 10 . About the markings 26a-26c can be the filling level of the collecting chamber 88 can be read. The collection chamber 88 is up to the mark 26b filled with water.

About the markings 78a-78d can be the state of wear of the filter element 14th can be read. The state of wear is at the wear level 78d so that the filter element 14th is to be exchanged.

The 13th to 15th show components of a liquid filter 10 , which has shoring protection. The display device 18th in this case has a locking body 82 on, which is to be moved from a locking position to a release position in order to couple the filter insert 14th with the display device 18th to enable. The filter insert 14th has an unlocking element 84 on, by means of which the locking body 82 is movable from the locking position to the release position. The blocking body 82 is operated by a return spring 86 acted upon by a restoring force, which the locking body 82 holds in the locked position, provided the locking body 82 not from the unlocking element 84 is moved out of the locked position.

In the 13th is the locking body 82 in the locking position in which the locking body 82 an elastic deformation of a material section of the display device 18th prevents the coupling of the filter element 14th with the display device 18th is required. An inward movement of the material protrusion on the panel side 92 is prevented so that the material protrusion on the filter element side without unlocking 90 cannot be moved past this.

In the 14th and 15th became the blocking body 82 through the unlocking element 84 moved out of the locked position. The deformation of the upper section of material of the visor body 24 is thus no longer through the locking body 82 with special needs. Thus, the display device 18th in the fastening section 52 of the filter insert 14th are clipped in by the filter-side material projection 90 by an elastic inward movement of the panel-side material projection 92 can be moved past this. The blocking body 82 after leaving the locked position gives the one for coupling the filter insert 14th with the display device 18th required elastic deformation of the material section of the display device 18th through the filter insert 14th free.

List of reference symbols

10

Liquid filter

12th

Filter housing

14th

Filter insert

16a, 16b

Sub-areas

18th

Display device

20a, 20b

Viewing window

22nd

Display body

24

Visor body

26a-26c

Markings

28

Closure element

30th

base

32a, 32b

Threaded sections

34

Filter material

36

Raw side

38

Clean side

40

Support structure

42

Interior dome

44a, 44b

End plates

46

Lock mount

48

Inner shell

50

Sliding surface

52

Fastening section

54

poetry

56

Spring element

58

Exhaust duct

60

Exhaust duct

62a, 62b

Locking mechanism

64a-64d

Support elements

66

Support surface

68

Inlet port

70

Retaining spring

72

Contact area

74

Contact area

76

Water sensor

78a-78d

Markings

80

Locking mechanism

82

Locking body

84

Unlocking element

86

Return spring

88

Collection chamber

90

Material protrusion

92

Material protrusion

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• US 2008/0053879 A1 [0006]

Claims (15)

Liquid filter (10), with - a filter housing (12); and - a filter insert (14) which is axially movable within the filter housing (12) and has filter material (34), the filter material (34) from a raw side (36) to a clean side (38) of the liquid filter (10) from a liquid to be filtered can be flowed through; characterized in that an axial movement of the filter insert (14) can be caused by a pressure difference between the raw side (36) and the clean side (38). Liquid filter (10) Claim 1 , characterized by a spring element (56) which counteracts the axial movement of the filter insert (14) and can be compressed and / or expanded apart by an axial movement of the filter insert (14). Liquid filter (10) Claim 1 or 2 , characterized by a detection device, in particular an electrical one, by means of which a position and / or the axial movement of the filter insert (14) can be detected and / or determined. Liquid filter (10) according to one of the preceding claims, characterized by a display device (18) by means of which a state of contamination of the filter material (34) based on the axial deflection of the filter insert (14) can be visually displayed. Liquid filter (10) Claim 4 , characterized in that the display device (18) has a latching mechanism (62a, 62b) by means of which a soiling state remains optically indicated after a pressure difference between the raw side (36) and the clean side (38) has been resolved. Liquid filter (10) Claim 4 or 5 , characterized in that the display device (18) has a visor body (24) which is designed to cover a display body (22) of the display device (18), the degree of obscuration of the display body (22) by the visor body (24 ) depends on the axial deflection of the filter insert (14). Liquid filter (10) Claim 6 , characterized in that the screen body (24) is coupled to the filter insert in such a way that the screen body (24) is moved in the axial direction by the filter insert (14) when the filter insert (14) is axially deflected, the coupling of the screen body (24) and the filter insert (14) preferably has an axial play which causes the diaphragm body (24) to move back through the filter insert (14) in the event of an opposite axial movement of the filter insert (14) after a pressure difference between the raw side (36) and the clean side (38) has been resolved. prevented. Liquid filter (10) Claim 6 or 7th , characterized in that the visor body (24) and the display body (22) are components of the latching mechanism (62a, 62b), wherein the visor body (24) and the display body (22) have corresponding latching sections, which via a relative movement of the visor body (24 ) and the display body (22) can be brought into engagement in different locking steps in the axial direction. Liquid filter (10) according to one of the Claims 6 to 8th , characterized in that the display device (18) comprises a viewing window (20a, 20b) in the filter housing (12), through which the degree of obscuration of the display body (22) by the visor body (24) is optically perceptible, in particular optically readable . Liquid filter (10) Claim 9 , characterized by a water separating device for separating water from the liquid, the water separating device having a collecting chamber (88) for the separated water and the filling level of the collecting chamber (88) being optically perceptible, in particular optically readable, via the viewing window (20a, 20b) . Liquid filter (10) according to one of the Claims 6 to 10 , characterized in that the display device (18) has a temperature-dependent locking mechanism (80), by means of which a relative movement between the display body (22) and the diaphragm body (24) can be prevented when the filter insert (14) is axially deflected. Liquid filter (10) according to one of the Claims 6 to 11 , characterized in that the display body (22) is axially movable, the screen body (24) exerting a drag force on the display body (22) when the filter insert (14) is axially deflected and the display body (22) is in a rest position by a temperature-controlled actuator is held until the entrainment force exceeds the holding force of the temperature-controlled actuator holding the display body (22) in the rest position. Liquid filter (10) Claim 12 , characterized in that the temperature-controlled actuator is designed as a retaining spring (70) made of a shape memory alloy. Liquid filter (10) according to one of the Claims 4 to 13th , characterized in that the display device (18) has a locking body (82) which is to be moved from a locking position to a release position in order to achieve a coupling of the To enable the filter insert (14) with the display device (18), the filter insert (14) preferably having an unlocking element (84) by means of which the blocking body (82) can be moved from the blocking position into the release position. Liquid filter (10) Claim 14 , characterized in that the blocking body (82) in the blocking position prevents elastic deformation of a material section of the display device (18) by the filter insert (14), which is necessary for coupling the filter insert (14) to the display device (18).

Images