A fuel distributor for facilitated disassembly of fuel rail assemblies

Abstract

The present disclosure proposes a fuel distributor (1) for a fuel rail assembly (100) for combustion engines. The fuel distributor (1) comprises one or more injector cups (2) with respective main central axes (A). Each injector cup (2) is arranged for engaging with a respective fuel injector (10). The one or more injector cups (2) are provided with one or more snag portions (21) for engaging with respective one or more snaggers (51) that are provided on one or more snagging tools (5). The one or more snag portions (21) are arranged to conduct a force exerted by the snagging tool (5) along the main central axis (A) in the first direction (z).

Description

[0001] SPECIFICATION

[0002] A FUEL DISTRIBUTOR FOR FACILITATED DISASSEMBLY OF FUEL RAIL ASSEMBLIES

[0003] Technical Field of the Invention

[0004] The present disclosure relates to a fuel distributor for a fuel charge assembly according to the preamble of Claim 1 .

[0005] Background of the Disclosure

[0006] Fuel rail assemblies or fuel charge assemblies, in particular for common rail systems, are known in the art. A fuel rail assembly generally includes a group of fuel injectors for provision of fuel through nozzles thereon, into respective combustion chambers of an internal combustion engine. Each of the fuel injectors is connected to a fuel distributor over respective injector cups at an opposite end of the fuel injector with regard to the nozzles. CN 212406922 U and WO 2012 / 150074 A1 disclose exemplary fuel distributors for use in fuel rail assemblies.

[0007] The injector cups connect each respective fuel injector to the fuel distributor. The injector cups can be formed on the fuel distributor, e.g., integral therewith. A fuel distributor is provided with a connection bore for allowing fluid flow coming from a fuel chamber of the fuel distributor to the fuel injectors via inner volume of the respective injector cups.

[0008] Attachment of the fuel injectors to respective injector cups can be achieved using fixing members such as U-clips, for axial stabilization of the fuel injectors relative to the injector cups. The fuel rail assembly can further include retaining arms for axially biasing the fuel injectors away from the respective injector cups. A retaining arm can be considered as a damper to axial forces that emerge during combustion in a combustion chamber and push the fuel injector away from the combustion chamber. So, retaining arms reinforce sealing between the fuel injectors and respective combustion chambers. TR 2016 / 19492 discloses an exemplary retaining arm for use in such fuel rail assemblies. Hence, a fuel rail assembly can be considered as a combined structure that includes a group of fuel injectors that are attached to a fuel distributor over respective injector cups via fixing members and that are provided with respective retaining arms.

[0009] Engagement between such fuel rail assembly and a respective group of combustion chambers involves the introduction of nozzle tips of the fuel injectors through open ends of respective combustion chambers. Such introduction is generally performed in a direction that extends along the gravity vector or that has a component in the gravitational direction when the engine is in use. Then, the fuel rail assembly is secured for stabilizing the same from moving relative to the combustion chambers along main central axes thereof. Because of the component in the gravitational direction, such fuel rail assembly can also be referred to as a suspended fuel rail assembly.

[0010] Maintenance and repair of a component of the fuel rail assembly requires the disassembly of the same. Such disassembly can involve removal of one or more of fixing members, so that one or more corresponding fuel injectors can be separated from respective injector cups.

[0011] The removal of a fixing member can require translation of the same in a radial direction with regard to a main central axis of the respective fuel injector, until the fixing member is completely separated from one or both of the injector cup and fuel injector. In some cases, the engine architecture does not allow such separation, because there is no sufficient room around the fixing member available for such radial translation of the same.

[0012] It is considered desirable to develop a solution to this problem.

[0013] Brief Description of the Disclosure

[0014] An object of the present disclosure is to provide a fuel distributor for fuel rail assemblies, which is easy to separate from a respective engine. Another object of the present disclosure is to provide a fuel distributor that allows an easy separation of fuel injectors from respective injector cups, even in the case of space limitations around a fixing member that holds the fuel injector and injector cup together.

[0015] The present disclosure proposes a fuel distributor for a fuel rail assembly for combustion engines. The fuel distributor comprises one or more injector cups with respective main central axes. The one or more injector cups are arranged for engaging with a respective fuel injector that has a nozzle tip, by receiving a first end of the fuel injector opposite to the nozzle tip in a first direction, through an opening of the injector cup. Said first direction is from the nozzle tip towards said first end. The injector cups are arranged for that, when engaged to the injector cup, the fuel injector extends along the respective main central axis.

[0016] The one or more injector cups are provided with one or more snag portions for engaging with respective one or more snaggers that are provided on one or more snagging tools. The one or more snag portions are arranged to conduct a force exerted by the snagging tool along the main central axis in the first direction. Hence, a fuel rail assembly that is provided with the fuel distributor according to the present disclosure can be detached from a corresponding combustion engine by pulling the fuel distributor at the one or more injector cups, using the snagging tool, in the first direction. So, the detachment of such fuel rail assembly from the combustion engine is performed by a translational movement along the main central axis. As a result, one or more fixing members that secure fuel injectors to respective injector cups are exposed for removal of the fixing members by radially pulling the same with regard to the main central axis. Thus, removal of the one or more fixing members is facilitated even in the case where a radial space around the injector cup is insufficient for on-site removal of the fixing member due to the architectural structure of a respective engine.

[0017] A possible embodiment according to the present disclosure of the fuel distributor can comprise two or more of the injector cups that are in accordance with the description discussed above. This embodiment allows an enhanced directional stability at pulling a fuel rail assembly with the fuel distributor according to the present disclosure away from an engine, by eliminating play in at least one of possible radial directions around the main central axis.

[0018] In a possible embodiment according to the present disclosure, the one or more snaggers can be arranged for engaging respective one or more snag portions, upon passing through a passage portion provided on the injector cup and then being moved in the first direction.

[0019] In a possible embodiment according to the present disclosure, the snagging tool can comprise one or more bars which can be provided with the one or more snaggers. In this case, a force to be exerted onto the injector cup in order to move the fuel distributor away from an engine, can be manually applied onto the bar and conducted to the injector cup through the bar.

[0020] The bar can comprise two or more snaggers. This enables evenly distributed conduction of said force to multiple injector cups at once. Considering that a combination of force that are distributed to multiple injector cups amounts to a total extent of force that would be necessary for separation of a fuel rail assembly from an engine, the extent of force per injector cup is reduced. Likewise, the extent of force exerted onto each injector cup for overcoming the gravity (g), is reduced at carrying such fuel rail assembly after separation from the engine.

[0021] In a possible embodiment according to the present disclosure, the snag portion can be provided on an extension. The extension can extend along the main central axis in the first direction. The snag portion can radially extend away from the main central axis. The extension can comprise a passage portion at a side of the snag portion, that can be relatively closer to the opening. In this embodiment, the snag portion can be considered as having the general shape of a pileus or head, and the passage portion can be considered as a neck that allows snagging of the snag portion by the snagger.

[0022] In a possible embodiment according to the present disclosure, the injector cup can comprise one or more radial cavities as passage portion. The snag portion can be an end of the cavity that is relatively distal to the opening with regard to the main central axis. The snag portion can be arranged for being engaged by a respective snagger in the form of a pin, when the snagger is radially introduced into the passage portion and then translated in the first direction. In this embodiment, the snag portion can be considered as having the general shape of a side wall of the cavity that is relatively distal with regard to the opening when compared to the remaining side wall portions of the cavity; and the passage portion receives the snagger to allow snagging of the snag portion.

[0023] In a possible embodiment according to the present disclosure, the one or more radial cavities can be formed on one or more extensions that extend along respective main central axes in the first direction. In this embodiment, the snag portion can be easily designed and formed without burden relevant to geometric considerations for engagement and cooperation between the injector cup and a respective injector.

[0024] In a possible embodiment according to the present disclosure, the one or more extensions can be arranged to overlap with the main central axes of respective injector cups. This embodiment provides orientational stability at separation of a fuel rail assembly with the fuel distributor according to the present disclosure, since the forces exerted onto an injector cup with such an extension will inherently also overlap with the main central axis.

[0025] In a possible embodiment according to the present disclosure, the one or more snagging tool can comprise one or more handles for manual translation of the snagging tool in the first direction; thereby facilitating the use of the snagging tool and enhancing the comfort of a user.

[0026] Brief Description of the Figures

[0027] Fig.1 is a schematical exploded front view of a fuel injector assembly with a first possible embodiment of the fuel distributor according to the present disclosure.

[0028] Fig.2 is a schematical exploded front view of a fuel injector assembly with a second possible embodiment of the fuel distributor according to the present disclosure.

[0029] Fig.3 is a schematical plan view of the snagging tool from Fig.1.

[0030] Fig.4 is a schematical plan view of the snagging tool from Fig.2.

[0031] Detailed Description of the Figures

[0032] The present disclosure proposes a fuel distributor (1) for a fuel rail assembly (100) with fuel injectors (10), that can be suitable for being employed in common rail systems. Two of possible fuel distributor (1) embodiments according to the present disclosure are schematically represented in Fig.1 and Fig.2.

[0033] Fig.1 is a schematical exploded front view of a fuel rail assembly (100) with a first possible embodiment of the fuel distributor (1) according to the present disclosure. Fig.1 represents an instance where the first embodiment of the fuel distributor (1) is aligned with a snagging tool (5), which is suitably arranged for engaging with one or more snaggers on the first embodiment of the fuel distributor (1).

[0034] Fig.2 is a schematical exploded front view of a fuel rail assembly (100) with a second possible embodiment of the fuel distributor (1) according to the present disclosure. Fig.2 represents an instance where the second embodiment of the fuel distributor (1) is aligned with a respective embodiment of a snagging tool (5), which is suitably arranged for engaging with one or more snag portion (21) on the second embodiment of the fuel distributor (1).

[0035] With reference to either of Fig.1 or Fig.2, the fuel distributor (1) according to the present disclosure comprises one or more injector cup (2) that are arranged for being engaged with respective fuel injectors (10), for thereby forming a fuel rail assembly (100).

[0036] The one or more injector cup (2) has respective main central axes (A). When engaged with a respective fuel injector (10) by axially receiving a first end (12) of the fuel injector (10) that is axially distal with regard to a nozzle tip (11) of the fuel injector (10), the cup (2) and fuel injector (10) can be considered coaxial by a main axis of the fuel injector (10). In other words, a main axis of a fuel injector (10) can be considered to overlap with the main central axis (A) of a respective injector cup (2). The direction in which the first end (12) of the fuel injector (10) is inserted into the injector cup (2) through an opening (20) thereof can be considered as a first direction (z), and as being parallel to the main central axis (A), or as overlapping with the main central axis (A). It can be contemplated that each of the one or more injector cups (2) are provided with a slot (24) for receiving the first end (12) of a respective fuel injector (10).

[0037] The one or more injector cups (2) are provided with one or more snag portions (21) that are arranged for being engaged by respective one or more snaggers (51) on one or more snagging tools (5). The one or more snag portions (21) are arranged for conduction of a force exerted by the snagging tool (5) along the main central axis (A) in the first direction (z), to the fuel distributor (1). So, an operator can engage the snagging tool (5) to the one or more snag portions (21), resulting in an engagement between the snagging tool (5) and the fuel distributor (1). The fuel distributor (1) can then be pulled by the one or more injector cups (2) by forcing the snagging tool (5) in the first direction (z). As a result, a fuel rail assembly (100) that is provided with the fuel distributor (1) according to the present disclosure can be detached from a corresponding combustion engine by simply pulling the one or more snag portions (21). So, the detachment of such fuel rail assembly (100) from the combustion engine is performed by a translational movement along the main central axis (A), in the first direction (z) or in a direction that has a component in the first direction (z). One or more fixing members (3), each of which secure a fuel injector (10) to a respective injector cup (2) are thus exposed; and removal of the fixing members (3) is then easily managed by radially pulling the same with regard to the main central axis (A). Thus, removal of the one or more fixing members (3) is facilitated even in the case where a radial space around the injector cup (2) is insufficient for on-site removal of the fixing member (3) due to architectural structure of a respective engine.

[0038] The fuel distributor (1) can comprise two or more of the injector cups (2), that are in accordance with the present disclosure by comprising the one or more snag portions (21). This embodiment allows an enhanced directional stability at pulling a fuel rail assembly (100) with the fuel distributor (1) away from an engine, by eliminating play in at least one of possible radial directions around the main central axis (A). The one or more snaggers (51) can be arranged for engaging the respective one or more snag portions (21), upon passing through a passage portion (23) provided on the injector cup (2) and then being moved in the first direction (z).

[0039] In a possible embodiment of the present invention, the snag portion (21) can be provided on an extension (22). The extension (22) can extend along the main central axis (A) in the first direction (z). The snag portion (21) can radially extend away from the main central axis (A). The extension (22) can comprise a passage portion (23).

[0040] In another possible embodiment of the present invention, the passage portion (23) can be considered to be disposed in-between the snag portion (21) and the opening (20), or in-between the snag portion (21) and the slot (24). In other words, the passage portion (23) can be located at a side of the snag portion (21), said side being relatively closer to the opening (20). An example to such embodiment is represented in Fig.1. Referring back to Fig.1 in conjunction with Fig.3; in such embodiment, the snag portion (21) can be considered as having a general shape of a pileus or head. With regard to the main central axis (A), the passage portion (23) can be considered as having the general shape of a neck by being radially narrower than the snag portion (21). This is considered as a possible way to enable the snagging of the snag portion (21) by the snagger (51). In this case, one or more of the snaggers (51) can be considered as being sized and shaped to receive and radially grasp the passage portion (23), by having an inner space such as that available in-between two adjacent fingers of a fork, or by being in the form of a groove.

[0041] Fig.3 and Fig.4 show schematical plan views of exemplary snagging tools (5) that are suitable for engaging a fuel distributor (1) embodiment that are represented in Fig.1 and Fig.2, respectively. With reference to Fig.3 and Fig.4; in a possible embodiment, the snagging tool (5) can comprise one or more bars (53) which can be provided with the one or more snaggers (51). So, a force to be exerted onto the injector cup (2) in the first direction (z) for moving the fuel distributor (1) away from an engine, can be manually applied onto the bar (53) in a facilitated way.

[0042] The embodiment shown in Fig.1 , in which the snag portion (21) is in the form of a head that is radially wider than a respective neck as the passage portion (23), provides a relatively easier alignment and snagging, when compared to the other possible embodiment that is discussed in the present disclosure, which comprises a cavity as a passage portion (23) as visually exemplified in Fig.2. On the other hand, it can be considered that the formation of a passage portion (23) is easier for the embodiment that is exemplified in Fig.2, in comparison with that which is exemplified in Fig.1 ; because drilling of a cavity as a passage portion (23) can be considered comparatively easier.

[0043] In an embodiment of the present invention, the number of snaggers (51) can be more than one, in other words, two or more. This enables an even distribution of the above- mentioned manually applied force to the injector cups (2), simultaneous with one another. Thus, the extent of force per injector cup (2) is reduced. Likewise, the extent of force exerted onto each injector cup (2) for overcoming the gravity (g), is reduced at carrying a respective fuel rail assembly (100) after separation from an engine. Hence, service life of the injector cup (2) and fuel distributor (1) is enhanced.

[0044] Fig.4 is a schematical plan view of an exemplary snagging tool (5) that is suitable for engaging the fuel distributor (1) embodiment that is represented in Fig.2. Referring back to Fig.2 in conjunction with Fig.4; in a possible embodiment, the injector cup (2) can comprise one or more radial cavities that can be considered as an embodiment of passage portion (23) and represented with the same reference sign. In this embodiment, the snag portion (21) can be considered as having the general shape of an inner side wall portion of the passage portion (23) that is relatively distal with regard to the opening (20) when compared to the remaining inner side wall portions of the passage portion (23); and the passage portion (23) receives the snagger (51) to allow the snagging of the snag portion (21). In other words, a portion of the side wall of the cavity as passage portion (23), that is axially distal to the opening (20) with regard to the main central axis (A), can be considered to function as an embodiment of the snag portion (21). The snag portion (21) can be arranged for being engaged by a respective snagger (51) that can be in the form of a pin such as those visually exemplified in Fig.4. In such case, the snagging can be achieved by radially introducing the snagger (51) (here: pin) into the passage portion (23) (here: cavity) and then translationally moving the snagger (51) in the first direction (z).

[0045] The one or more passage portions (23) that are in the form of radial cavities can be formed on one or more extensions (22) that extend along respective main central axes (A) in the first direction (z). In such embodiments, the snag portion (21) and passage portion (23) are axially away from the slot (24). Hence, the snag portion (21) can be easily designed and formed without burden, that is, without necessitating any further considerations on geometry of the injector cup (2) around the slot (24). So, existing geometric design parameters that are relevant to enablement of engagement and cooperation between the injector cup (2) and a respective fuel injector (10) can be applied without change, to the possible embodiments with the extensions (22). In a possible embodiment in which the one or more extensions (22) can be arranged to overlap with the main central axes (A) of respective injector cups (2); an enhanced orientational stability is provided at separation of a fuel rail assembly (100) with such embodiment of the fuel distributor (1). The reason to this is that the forces exerted onto an injector cup (2) with such an extension (22) inherently overlaps with the main central axis (A). This feature minimizes or even eliminates the forces that can apply onto the fuel injector (10) in directions that are transverse to the main central axis (A), at separation of a fuel rail assembly (100) with the fuel distributor (1), from an engine. Thus, the possibility of mechanical damage is reduced and the service life is extended. The one or more snagging tool (5) can be provided with one or more handles (52), arranged for translationally moving the snagging tool (5) by hand, in the first direction (z). This provides an enhanced comfort at use and facilitates the operation of the snagging tool (5).

[0046] Reference list:

[0047] 1 fuel distributor

[0048] 2 injector cup

[0049] 20 opening

[0050] 21 snag portion

[0051] 22 extension

[0052] 23 passage portion

[0053] 24 slot

[0054] 3 fixing member

[0055] 4 retaining arm

[0056] 5 snagging tool

[0057] 51 snagger

[0058] 52 handle

[0059] 53 bar

[0060] 10 fuel injector

[0061] 11 nozzle tip

[0062] 12 first end

[0063] 100 fuel rail assembly

[0064] A axis g gravity z first direction

Claims

CLAIMS1. A fuel distributor (1) for a fuel rail assembly (100) for combustion engines, the fuel distributor (1) comprising one or more injector cups (2) with respective main central axes (A); each injector cup (2) arranged for engaging with a respective fuel injector (10) with a nozzle tip (11) by receiving a first end (12) of the fuel injector (10) opposite to the nozzle tip (11) in a first direction (z) from the nozzle tip (11) towards said first end (12), through an opening (20) of the injector cup (2), such that the fuel injector (10) extends along the respective main central axis (A) when engaged to the injector cup (2); characterized in that, the one or more injector cups (2) are provided with one or more snag portions (21) for engaging with respective one or more snaggers (51) that are provided on one or more snagging tools (5), the one or more snag portions (21) are arranged to conduct a force exerted by the snagging tool (5) along the main central axis (A) in the first direction (z).

2. The fuel distributor (1) according to claim 1 ; wherein the one or more snaggers (51) are arranged for engaging respective one or more snag portions (21) upon passing through a passage portion (23) provided on the injector cup (2) and then being moved in the first direction (z).

3. The fuel distributor (1) according to claim 2; wherein the snagging tool (5) comprises one or more bars (53) which is provided with the one or more snaggers (51).

4. The fuel injector (1) according to claim 3; wherein the bar (53) is provided with two or more snaggers (51).

5. The fuel distributor (1) according to anyone of claims 1 to 4; wherein the snag portion (21) is provided on an extension (22) that extends along the main central axis (A) in the first direction (z) and; the extension (22) comprises a passage portion (23) disposed in-between the snag portion (21) and the opening (20); and the snag portion (21) is radially wider than the passage portion (23) with regard the main central axis (A).

6. The fuel distributor (1) according to anyone of claims 1 to 4; wherein the injector cup (2) comprises one or more radial cavities as the passage portion (23); the snag portion (21) is an end of the passage portion (23) that is relatively distal to the opening (20) with regard to the main central axis (A); the snag portion (21) is arranged for being engaged by a respective snagger (51) in the form of a pin, when the snagger (51) is radially introduced into the passage portion (23) and then translated in the first direction (z).

7. The fuel distributor (1) according to claim 6; wherein the one or more passage portions (23) are formed on one or more extensions (22) that extend along respective main central axes (A) in the first direction (z).

8. The fuel distributor (1) according to anyone of claims 5 or 7; wherein the one or more extensions (22) overlap with the main central axes (A) of respective injector cups (2).

9. The fuel distributor (1) according to any of claims 1 to 8; wherein the snagging tool (5) comprises one or more handles (52) for manual translation of the snagging tool (5) in the first direction (z).

10. The fuel distributor (1) according to anyone of claims 1 to 9, comprising two or more of the injector cups (2).

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