Device for sealing an opening of a tank, system comprising the tank and the device

Abstract

The invention relates to a device (10) for sealing an opening (12) of a tank (14) and a tank (14) comprising the device (10), wherein the opening (12) comprises an interface (16) configured to receive the device (10), the device (10) comprising: a housing (22); a seal (18) configured to seal the opening (12) via the interface (16); a seal carrier (26) configured to receive the seal (18) and movable at least axially relative to the housing (22); a spring (20) arranged between the housing (22) and the seal carrier (26), configured to press the seal (18) against the interface (16) by means of a spring force acting on the seal carrier (26), which is oriented particularly axially (28);and a pressure ring (30) designed to move the housing (22) axially (28) relative to the sealing carrier (26) when the housing (22) is rotated relative to the pressure ring (30), so that the spring force varies to press the seal (18) against the interface (16).

Description

The present invention relates to a device for sealing an opening of a tank and a system comprising the tank and the device. DE 3025185 A1 discloses a fuel tank closure. DE 3505136 A1 discloses a closure arrangement for the filler neck of a container. EP 0080624 A1 discloses a closure cap, in particular for a fuel tank. Sealing caps for tanks, for example for liquids or gases, seal an opening of the tank to prevent the unwanted escape of the medium contained within. In known systems, pressure builds up inside the tank against a spring force of the sealing cap, which is correlated, for example, with the contact force of a seal against the opening. In known sealing caps, the pressure builds up against the full effective diameter of the cap. This pressure build-up reduces the spring force, which can lead to leakage at the opening. To counteract this, the spring force on the sealing cap is increased, which in turn creates a torque required to screw the sealing cap onto and off the opening. These sealing caps are often leaky or cannot be installed without tools. Accordingly, a tank closure cap is desirable in which a spring force and thus a compression of the seal remains essentially maintained or constant despite pressure build-up or pressure fluctuations in the tank, thereby improving the tightness and mountability of the closure cap on an opening of the tank, or making it essentially independent of the pressure build-up within the tank. This is achieved by a device and a system according to the independent claims. The device for sealing an opening of a tank, wherein the opening comprises an interface configured to receive the device, comprises: a housing; a seal configured to seal the opening across the interface; a seal carrier configured to receive the seal and movable at least axially relative to the housing; a spring arranged between the housing and the seal carrier, configured to press the seal against the interface by means of a spring force acting on the seal carrier, which is in particular axially oriented; and a pressure ring configured to move the housing axially relative to the seal carrier when the housing is rotated relative to the pressure ring, such that the spring force varies to press the seal against the interface. In this context, the term "tank" refers specifically to containers designed to hold liquids or gases. It is also conceivable that the tank is designed to hold solids, for example, in the form of granules or pellets. The tank can be a liquid container. For example, the tank can be a vehicle's tank, such as that of a motor vehicle, designed to hold the vehicle's fuel or alternative consumables. Alternative consumables include, for example, fluids used for exhaust aftertreatment, cooling, or the vehicle's braking system. In this context, "axial" describes a direction, such as an opening direction or the direction in which the device is inserted into or removed from the opening. This direction is, for example, orthogonal to an imaginary opening plane. "Axially" also describes, for example, a direction relative to the device itself, in which an axis of rotation is oriented around which the device is rotated to open or close it onto the opening or interface. An axial movement is, for example, a movement along or parallel to a principal axis of the device. The principal axis is, for example, the axis of rotation around which the device is rotated to open or close it. In this context, an axial direction describes a direction that is axially oriented.In the present context, the terms "turning on" and "turning off" and related terms refer to turning the device onto the opening to close the opening and turning the device off the opening to open the opening. The pressure ring, which creates relative movement between the housing and the sealing carrier, allows the device to be designed in such a way that the sealing carrier is essentially completely surrounded by pressure from inside the tank. Thus, the sealing carrier is essentially entirely within the tank's pressure system. This makes the spring force acting between the housing and the sealing carrier, which correlates with the sealing pressure at the interface, robust and independent of the pressure or pressure fluctuations inside the tank. The sealing pressure at the interface, for example, characterizes the tightness of the opening sealed by the device. Since the contact pressure is essentially independent of the pressure inside the tank, the spring can be dimensioned more simply and lower spring forces can be used. Thus, the device can be mounted with a torque that remains essentially constant and is primarily influenced by the controllable or predictable spring force. The pressure ring also enables a device design in which the seal carrier is rotatably arranged around the housing. This prevents sliding friction between the seal and the interface, which would otherwise occur when screwing the device on or off, especially above a certain contact pressure. This protects the seal and reduces the torque required to screw the device on or off. It may be provided that the pressure ring includes at least one engagement section extending radially outward and designed to engage with a hook section of the interface through a rotational movement of the pressure ring. In this context, "radial" describes, for example, a direction orthogonal to the axial direction and oriented towards or away from the main axis. "Outward" in this context means that the radial direction is oriented away from the main axis. A radial direction, in this context, describes a direction that is radially oriented. It can be provided that at least one engagement section is designed to stop the rotational movement of the pressure ring when it comes into contact with a stop encompassed by the hook section, thus preventing the housing from rotating relative to the pressure ring. This allows for a space-saving and production-efficient way to rotate the housing relative to the pressure ring. The resulting movement sequence of the device, for example when screwing it on, involves first inserting the device into or against the opening. In the first stage, the entire device, including all its components, rotates so that at least one engagement section engages with the hook section, similar to a bayonet fitting. When at least one engagement section comes into contact with the stop, rotation of the pressure ring is prevented or stopped.If the device continues to rotate in a second phase of the movement, a relative rotation occurs between the pressure ring and the housing, as the rotation of the pressure ring is blocked by the stop. The previously described movement sequence occurs, for example, in reverse order when the device is turned. The device may include a locking mechanism that is fixed to the housing, for example, by positive locking, and is designed to axially couple the pressure ring to the housing. The locking mechanism reduces the complexity of the device's design, as, for example, no undercuts need to be incorporated into the housing. Furthermore, assembly of the device is simplified, since, for example, the spring, the seal carrier, and the pressure ring can be placed onto the housing and then held in place, particularly axially, by subsequently securing the locking mechanism to the housing.Furthermore, the locking mechanism, due to the axial coupling of the locking mechanism and the pressure ring, simplifies the realization of the relative axial movement between the housing and the sealing carrier. The locking mechanism may include at least one locking pin that extends radially outwards and axially couples the locking mechanism to the pressure ring. The locking pin reduces the complexity of the device's design and the interface configuration. The locking pin allows for efficient and space-saving axial coupling between the pressure ring, the locking mechanism, and consequently, the housing. The engagement section may be provided with an axially oriented contact surface, and the at least one locking pin may at least partially radially overlap the engagement section and be in contact with the contact surface. The contact surface comprises a ramp with an axial slope. During rotation of the housing relative to the pressure ring, the at least one locking pin moves tangentially along the contact surface and over the ramp to move the housing axially relative to the seal carrier and to vary the spring force. In this context, "tangential" describes a direction that is orthogonal to the radial direction. The contact surface with the ramp enables a space-saving implementation of the axial movement of the housing, to which the locking mechanism is attached, relative to the seal carrier, so that the spring is compressed between the seal carrier and the housing, and the spring force is varied.The slope is designed or oriented in such a way that the spring is compressed when the device is turned, thereby increasing the spring force, which increases the contact pressure of the seal on the interface. It may be provided that the contact surface at one end of the ramp has a snap bead over which the at least one locking pin can be moved, particularly when moving the device into a closed position. In this context, the closed position describes a position of the device on the opening in which the device is turned up to a predetermined stop or end and seals the opening. The snap bead allows the user of the device to receive feedback indicating that the device has reached the closed position. When the device is turned, from the point of contact between the at least one engagement section and the stop of the hook section, the locking pin is moved across the contact surface as the device continues to turn and snaps into place at a specific point over the snap bead, generating, for example, an audible click.This improves the user's handling of the device. The seal can be designed to seal the opening axially across the interface and radially across the housing. This improves the sealing of the opening, and the seal carrier can be positioned in a pressure-neutral manner relative to the pressure inside the tank, so that it essentially experiences no forces induced by the pressure inside the tank. The device may include a cover that is coupled to the housing, in particular by means of a coupling, to transmit a rotational movement of the cover to the housing. The cover protects the device against external influences and improves handling for the user. A system comprises the tank and the device, wherein the tank includes an opening with an interface, the interface being configured to accommodate the device for sealing the opening. Further features and details will become apparent from the following description, in which exemplary embodiments of the invention are illustrated with reference to the drawing. The features mentioned in the claims and the description can each be essential to the invention individually or in any combination. The drawing shows: Fig. 1A a schematic sectional view of a device for sealing an opening of a tank in an insertion position; Fig. 1B a schematic sectional view of the device in a hook-in position; Fig. 1C a schematic sectional view of the device in a closed position; Fig. 2A a schematic partial section of the device in the hook-in position; Fig. 2B a schematic partial section of the device in the closed position; Fig. 3A a schematic bottom view of the device in the insertion position; Fig. 3B a schematic bottom view of the device in the hook-in position; Fig. 3C a schematic view of the device in the closed position; Fig. 1A shows a sectional view of a device 10 for sealing an opening 12 of a tank 14 in an insertion position. The opening 12 includes an interface 16 configured to receive the device 10. The device 10 is, for example, a closure or a cap for the tank 14. In this context, the insertion position describes a position of the device 10 in which it is loosely inserted into the interface 16 or the opening 12. Thus, the insertion position indicates a state of the device 10 in which it does not seal the opening 12. The state of the device 10 in the insertion position also corresponds, for example, to a state of the device 10 in which it is completely detached from the tank 14 or the opening 12. The device 10 comprises a housing 22, which, for example, forms a base body of the device 10 to which further components are arranged. The device 10 includes a seal 18 configured to seal the opening 12 via the interface 16. The seal 18 is in contact with the interface 16 and is pressed against the interface 16 or a sealing surface of the interface 16, in particular by a predeterminable contact pressure or a predeterminable contact force, in order to seal the opening 12. The device 10 includes a seal carrier 26 configured to receive the seal 18. The seal 18 is, for example, fixed to the seal carrier 26. The seal carrier 26 is movable at least axially 28 relative to the housing 22. It may be provided that the sealing carrier 26 is also arranged to be rotatably movable relative to the housing 22, for example, once internal friction between individual parts of the device 10 has been overcome. It is also conceivable that the rotary movement between the housing 22 and the sealing carrier 26 is possible within a predetermined angular range due to internal mechanical stops. The device 10 comprises a spring 20, which is arranged between the seal carrier 26 and the housing 22 and which is configured to press the seal 18 against the interface 16 by means of a spring force acting on the seal carrier 26, which is oriented particularly axially 28. The spring force acts between the housing 22 and the seal carrier 26. It is transmitted to the seal 18 via the seal carrier 26. The device 10 comprises a pressure ring 30 configured to move the housing 22 axially 28 relative to the sealing carrier 26 when the housing 22 rotates relative to the pressure ring 30, thus varying the spring force to press the seal 18 against the interface 16. For example, due to internal friction, the pressure ring 30 moves with the rotation of the device 10 until its movement is blocked. This blocking results in a relative rotation between the housing 22 and the pressure ring 30 when the device 10 continues to rotate. This relative rotation causes the housing 22 to move axially relative to the sealing carrier 26, thereby compressing or relaxing the spring 20 and varying the spring force.It can be provided that the pressure ring 30 is connected to the sealing carrier 26 in such a way, for example in a form-fitting manner, that essentially no relative rotation between them is possible. The device 10 may include a locking mechanism 24 that is fixed to the housing 22, for example by a positive locking mechanism, and which is designed to axially couple the pressure ring 30 to the housing 22. In the example shown, the locking mechanism 24 is firmly coupled to the housing 22, and the sealing carrier 26 is pressed against the locking mechanism 24 and thus against the housing 22, for example, by a preload of the spring 20. The locking mechanism 24 can enable a simple assembly of the device 10, for example, by first placing the spring 20, the sealing carrier 26, and the pressure ring 30 onto the housing 22, and finally the locking mechanism 24 completes and holds this assembly together.It is conceivable that the seal 18, the seal carrier 26, the pressure ring 30, the locking device 24 and the housing 22 are essentially designed in a ring or cylinder shape around a main axis 58, so that the device 10 can, for example, seal a roundly shaped opening 12. Fig. 1B shows a sectional view of the device 10 in an engaged position. The engaged position can, for example, be described as an intermediate position. The device 10 is rotated from the insertion position until it reaches the engaged position. In this context, the engaged position is characterized by the fact that if the device 10 continues to rotate beyond the engaged position, the pressure ring 30 is rotationally blocked. Consequently, further rotation results in a relative rotation between the housing 22 and the pressure ring 30. The pressure ring 30 may comprise at least one engagement section 32 extending radially outwards, configured to engage a hook section 36 of the interface 16 through a rotational movement of the pressure ring 30. The pressure ring 30 may also comprise at least two opposing engagement sections 32. This results in improved force transmission between the individual parts of the device 10 and prevents the individual parts from tilting relative to one another. Accordingly, it is conceivable that the interface 16 may also comprise at least two, in particular opposing, hook sections 36. The hook section(s) 36 are, for example, configured such that the engagement section(s) 32 can engage with them, similar to a bayonet fitting.For the sake of simplicity, the terms hook-in section 36 and engagement section 32 are used in the singular below; however, this does not preclude the possibility that several engagement sections 32 or hook-in sections 36 may be provided. The engagement section 32 may be designed to stop the rotational movement of the pressure ring 30 when the engagement section 32 comes into contact with a stop 38 encompassed by the hook section 36, thus resulting in the rotation of the housing 22 relative to the pressure ring 30. The individual parts of the device 10, in particular the housing 22, the seal carrier 26, the locking mechanism 24, and the pressure ring 30, rotate together with the device 10 until the pressure ring 30 comes into contact with the stop 38 of the hook section 36 – in the hook position. An axial clearance may be provided between the interface 16 and the seal 18 so that the seal 18 does not rub against the interface 16 when screwed into the hook position. Fig. 1C shows a sectional view of the device 10 in a closed position. In the closed position, the device 10 is screwed onto the opening 12 and seals it. In the closed position, the seal 18 is pressed against the interface 16 by the contact force to seal the opening 12. Compared to Figs. 1A and 1B, Fig. 1C shows a gap between the seal carrier 26 and the locking mechanism 24 or the housing 22. This gap is created by the axial movement between the housing 22 or the locking mechanism 24 and the seal carrier 26 relative to each other. This compresses the spring 20 and, accordingly, presses the seal 18 against the interface 16 by the contact force. The contact force or a profile of the contact force can be determined, for example, by dimensioning the spring 20. If the device 10 is rotated beyond the engagement position, the pressure ring 30, and for example also the sealing carrier 26 along with the seal 18, stops at the stop 38 while the housing 22 and the locking mechanism 24 continue to rotate. This results in the relative rotation between the housing 22 and the pressure ring 30, and the housing 22 is moved axially relative to the sealing carrier 26 and, for example, pushed deeper into the tank 14 and through the opening 12, while the seal 18 is prevented from axial movement by the interface 16. Thus, the seal 18 is pressed against the interface 16 depending on the varying spring force. Fig. 2A shows a partial section view of the device 10 in the hook-in position. The engagement section 32 of the pressure ring 30 is in contact with the stop 38 of the hook-in section 36 of the interface 16. The locking mechanism 24 may comprise at least one locking pin 40 extending radially 34 outwards and coupling the locking mechanism 24 axially 28 to the pressure ring 30. The term locking pin 40 is used in the singular in the following text; however, this does not preclude the possibility of multiple locking pins 40. It may be possible for a number of engagement sections 32 and / or hook sections 36 and / or locking pins 40 to be identical. The engagement section 32 may have an axially oriented contact surface 46, and the at least one locking pin 40 may at least partially radially overlap the engagement section 32 and be in contact with the contact surface 46. The contact surface 46 has a ramp 42 with an axial slope, wherein the at least one locking pin 40 moves tangentially 44 along the contact surface 46 and over the ramp 42 during rotation of the housing 22 relative to the pressure ring 30, in order to move the housing 22 axially relative to the sealing carrier 26 and to vary the spring force. Due to the slope in the axial direction, an offset increases between the pressure ring 30 and the locking mechanism 24 or the housing 22, respectively, as the locking pin 40 moves over the ramp 42. Fig. 2B shows a partial section view of the device 10 in the closed position. The locking pin 40 has moved across the ramp 42 by the further rotation of the device 10 and the stopping of the pressure ring 30 against the stop 38, thus varying or increasing the spring force. It can be provided that the locking pin 40 is blocked in the closed position by a section of the stop 38 or by a stop 38 provided on the pressure ring 30. This allows a defined closed position to be specified, beyond which the housing 22 and the locking mechanism 24, or the device 10, cannot be rotated. Starting from the hook position, as the device 10 continues to rotate, the locking mechanism 24 is moved via the ramp 42 of the pressure ring 30 to an end point, for example, the stop 38. The locking mechanism 24 thereby pulls the housing 22 axially towards the interface 16, where the seal 18 and the seal carrier 26 are pressed against the interface 16 by the spring 20. The contact surface 46 at one end 48 of the ramp 42 may have a snap bead 50 over which the at least one locking pin 40 can be moved, particularly when the device 10 is moved into a closed position. The locking pin 40 snaps over the snap bead 50 when the device 10 reaches the closed position. The snap bead 50 triggers feedback that the closed position has been reached, and the closed position is held until the device 10 is actuated again, for example, by turning it. Any actuating torque that occurs when turning the device 10 is controlled by the spring 20 and is essentially not influenced by the pressure inside the tank 14. The seal 18 can be designed to seal the opening 12 axially 28 across the interface 16 and radially 34 across the housing 22. This radial 34 sealing is shown, for example, in the section 60 in Figures 2A and 2B. In the illustrated example, a corresponding section of the seal 18, which provides the radial seal, slides axially along a corresponding sealing section of the housing 22 when the housing 22 moves axially 28 towards the seal carrier 26. The device 10 may include a cover 54 which is coupled to the housing 22, in particular by means of a coupling 56, in order to transmit a rotational movement of the cover 54 to the housing 22. Figures 3A to 3C show a bottom view of the device 10 in the insertion position, the hooking position and the closing position. The interface 16 may be designed to accommodate the device 10, as described above, for sealing the opening 12. For this purpose, the interface 16 may have at least one insertion section 52 through which the engagement section 32 can be inserted. The insertion section 52 may, for example, be a recess. In particular, the insertion section 52 exposes the hook section 36 of the interface 16, allowing the engagement section 32 of the pressure ring 30 to be inserted into the hook section 36. Fig. 3A shows the device 10 in the insertion position. The engagement sections 32 are inserted into the hook section 36 interface 16 by insertion sections 52. Fig. 3B shows the device 10 in the hook-in position. In the illustrated example, the device 10 was rotated from the insertion position by, for example, 125°, whereby the engagement section 32 was guided along the hook-in section 36 to the stop 38. Up to this position, all individual parts of the device 10 rotate together. Fig. 3C shows the device 10 in the closed position. In the illustrated example, this position is achieved by a further rotation of, for example, an additional 24°. During this rotation, the pressure ring 30 and, optionally, the sealing carrier 26 are blocked in their rotation by the stop 38. Accordingly, the locking pin 40 is guided into the closed position via the ramp 42 and the optional snap bead 50. The resulting relative rotation between the pressure ring 30 and the closure leads to the relative axial movement between the housing 22 and the sealing carrier 26, which is pressed against the interface 16 via the seal 18. In other words, the locking mechanism 24 pulls the housing 22 against the interface 16, against which the seal 18 and the sealing carrier 26 are pressed by the spring 20. In the closed position, the device 10 is clamped in the interface. In the example shown in Figures 3A to 3C, the device 10 is clamped into the interface 16 via the cover 54 through the coupling 56 onto the pressure ring 30 and the locking mechanism 24. This arrangement, and in particular the locking mechanism 24 and the pressure ring 30, allows for a configuration in which the spring 20 and the sealing carrier 26 are essentially completely enclosed by the volume of the tank 14 and, consequently, also by the pressure within the tank 14. Therefore, the pressure of the tank 14 acts on both sides of the sealing carrier 26, thus compensating for its effect on the sealing carrier 26, which then only transmits the spring force to the seal 18.

Claims

Device (10) for sealing an opening (12) of a tank (14), wherein the opening (12) comprises an interface (16) configured to receive the device (10), the device (10) comprising: - a housing (22); - a seal (18) configured to seal the opening (12) via the interface (16); - a seal carrier (26) configured to receive the seal (18) and movable at least axially relative to the housing (22); - a spring (20) arranged between the housing (22) and the seal carrier (26), configured to press the seal (18) against the interface (16) by means of a spring force acting on the seal carrier (26), which is particularly axially oriented;and a pressure ring (30) designed to move the housing (22) axially relative to the sealing carrier (26) when the housing (22) is rotated relative to the pressure ring (30), so that the spring force varies to press the seal (18) against the interface (16). The device (10) according to claim 1, wherein the pressure ring (30) comprises at least one engagement section (32) which extends radially outwards and which is configured to engage in a hook section (36) of the interface (16) by means of a rotational movement of the pressure ring (30). The device (10) according to claim 2, wherein the at least one engagement section (32) is configured to stop the rotational movement of the pressure ring (30) when the at least one engagement section (32) comes into contact with a stop (38) encompassed by the hook section (36), so that the rotation of the housing (22) relative to the pressure ring (30) results. The device (10) according to one of the preceding claims, comprising a locking mechanism (24) which is fixed to the housing (22), for example by positive locking, and which is configured to axially couple the pressure ring (30) to the housing (22). The device (10) according to claim 4, wherein the locking mechanism (24) comprises at least one locking pin (40) which extends radially outwards and couples the locking mechanism (24) axially with the pressure ring (30). The device (10) according to claims 2 and 5, wherein the engagement section (32) has an axially oriented contact surface (46) and the at least one locking pin (40) at least partially radially overlaps the at least one engagement section (32) and is in contact with the contact surface (46), wherein the contact surface (46) comprises a ramp (42) with an axial slope, wherein the at least one locking pin (40) moves tangentially (44) along the contact surface (46) and over the ramp (42) during the rotation of the housing (22) relative to the pressure ring (30) in order to move the housing (22) axially relative to the sealing carrier (26) and to vary the spring force. The device (10) according to claim 6, wherein the contact surface (46) at one end (48) of the ramp (42) has a snap bead (50) over which the at least one locking pin (40) can be moved, in particular when moving into a closed position of the device (10). The device (10) according to one of the preceding claims, wherein the seal (18) is configured to seal the opening (12) axially via the interface (16) and radially via the housing (22). The device (10) according to one of the preceding claims, comprising a cover (54) coupled to the housing (22), in particular by means of a coupling (56) to transmit a rotational movement of the cover (54) to the housing (22). A system comprising a tank (14) and a device (10) according to any one of claims 1 to 9, wherein the tank (14) comprises an opening (12) with an interface (16), wherein the interface (16) is configured to accommodate the device (10) for sealing the opening (12).

Images