A fuel distributor for facilitated disassembly of fuel rail assemblies

Abstract

The present invention proposes a fuel distributor (1) for a fuel rail assembly (100). The fuel distributor (1) comprises one or more injector cups (2) provided on a tube (21). The fuel distributor (1) is provided with end caps (22) at both ends of the tube (21) with regard to a tube axis (A1); the one or more end caps (22) are arranged to, when in use, axially extend from the tube (21) at a length (L1) along the tube axis (A1). The one or more end caps (22) comprise one or more circumferential grooves (24) provided around the tube axis (A1); the grooves (24) have a width (L2) along the tube axis (A1); and a ratio of the width (L2) to the length (L1) is 0.1 or greater.

Description

[0001] SPECIFICATION

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

[0003] Technical Field

[0004] The present disclosure relates to a fuel distributor 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. Fuel provided into the fuel distributor that includes a tube is communicated into fuel injectors through injector cups that have a respective inner volume that is in fluid flow communication with the tube hole of such tube. One or both ends of the tube of a fuel distributor can be closed using respective end caps, which can be considered to serve as a blind plug or stopper. 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 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. These objects are achieved by means of the features that constitute the appended independent claim.

[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 provided on a tube for communicating fuel from the tube to respective fuel injectors when the fuel injectors are engaged to the one or more injector cups. The fuel distributor is provided with end caps at both ends of the tube with regard to a tube axis. The one or more end caps are arranged to, when in use, axially extend from the tube at a first length along the tube axis.

[0016] The one or more end caps comprise one or more circumferential grooves provided around the tube axis. The grooves have a width along the tube axis; and a ratio of the width to the length is 0.1 or greater.

[0017] Using a suitably designed tool, the proposed fuel distributor facilitates the process of separation of a fuel rail assembly that is equipped with the proposed fuel distributor, from a corresponding engine block.

[0018] Locating and catching of the one or more grooves is easier with greater ratios of the width to length. Accordingly, in a possible embodiment, the ratio of the width to the length is 0.3 or greater. In a further possible embodiment, the ratio of the width to the length can be 0.5 or greater.

[0019] In a possible embodiment, the end cap comprises a head portion at an axially distal end with regard to a center of the tube. When compared to the groove, the head portion can have a greater diameter than a diameter of the groove in radial directions around the tube axis. The head portion facilitates the locating and engaging of the tool in the groove using a suitably designed tool. It also prevents the head portion from dispersing the tool from the cavity.

[0020] The present disclosure further proposes a tool for engaging the fuel distributor. The tool comprises one or more catchers that are arranged for being received by the one or more grooves. The tool can be provided in a kit that also includes one or more of the proposed fuel distributors in accordance with any of the embodiments that are discussed in the present specification.

[0021] In a possible embodiment of the tool: along the tube axis, a value of a thickness of the one or more catchers of the tool, when in use, can have a smaller value when compared to the width of one or more grooves. In a possible embodiment, or furthermore, the one or more catchers can have a tapered cross-section, such that the thickness has reduced values at sections of the catchers that are radially closer to the corresponding grooves, when in use with regard to the tube axis. These measures provide an even more facilitated operation when separating a fuel rail assembly with the proposed fuel distributor, from an engine. Brief Description of the Figures

[0022] Fig.1 is a schematical exploded front view of an exemplary fuel injector assembly in which an exemplary embodiment of the fuel distributor according to the present disclosure is employed, aligned with an exemplary embodiment of the tool according to the present disclosure.

[0023] Fig.2 is a close-up view of detail-F form Fig.1.

[0024] Detailed Description of the Figures

[0025] 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.

[0026] Fig.1 depicts an exploded side view of an exemplary fuel rail assembly (100) that is provided with a possible embodiment of the proposed fuel distributor (1) according to the present disclosure. Fig.1 shows an instance where an exemplary embodiment of a tool (5) for extraction of the fuel rail assembly (100) from a combustion engine block, is aligned with the proposed fuel distributor (1). The nozzle tips (11) of the fuel injectors (10) are directed towards inside the combustion chamber ( not shown in the figures ) but also first ends (15) of the fuel injectors (10) are received towards inside by openings (20) which are formed on the injector cups (2). Such introduction is generally performed in a direction that extends along the gravity vector (g) or that has a component in the gravitational direction when the engine is in use.

[0027] Hence, a fuel rail assembly (100) can be considered as a combined structure that includes a group of fuel injectors (10) that are attached to a fuel distributor (1) over respective injector cups (2) via fixing members (3) and that are provided with respective retaining arms (4). Also, mounting brackets (25) are provided between the injector cups (2) to mount the fuel distributor (1) to the engine block.

[0028] Referring to Fig.1 , 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) provided on a tube (21) for communicating fuel from the tube (21) to respective fuel injectors (10) when the fuel injectors (10) are engaged to the one or more injector cups (2). The fuel distributor (1) is provided with end caps (22) at both ends of the tube (21) with regard to a tube axis (A1). The one or more end caps (22) are arranged to, when in use, axially extend from the tube (21) at a length (L1) along the tube axis (A1). The one or more end caps (22) comprise one or more circumferential grooves (24) provided around the tube axis (A1). The grooves (24) have a width (L2) along the tube axis (A1); and a ratio of the width (L2) to the length (L1) is 0.1 or greater.

[0029] In a possible embodiment of the invention, the ratio of the width (L2) to the length (L1) can be 0.3 or greater. In a further possible embodiment, the ratio of the width (L2) to the length (L1) can be 0.5 or greater.

[0030] In a possible embodiment of the invention, the end cap (22) comprises a head portion

[0031] (23) at an axially distal end with regard to the tube (21). When compared to the groove

[0032] (24), the head portion (23) can have a greater diameter than a diameter of the groove (24) in radial directions around the tube axis (A1).

[0033] The fuel distributor (1) is thus arranged for being engaged by a tool (5) that is provided with one or more catchers (51) that are sized and shaped for being aligned and engaged with the respective one or more grooves (24).

[0034] The one or more catchers (51) can be hook-shaped as represented in Fig.1 , such that when the one or more catchers (51) are approached towards the respective grooves (24) in a radial direction with regard to the tube axis (A1), the hook-shaped catchers (51) can be received by the respective grooves (24).

[0035] Alternatively, in a possible embodiment of the invention, the one or more catchers (51) can be in a ring-shaped and pivotable, such that when the one or more catchers (51) are approached towards the respective grooves (24) in an axial direction along the tube axis (A1) and then moved in a radial direction with regard to the tube axis (A1), the ringshaped catchers (51) can be received by the respective grooves (24).

[0036] In any of the cases discussed above, it can be contemplated that the one or more catchers (51) inherently have a thickness (T) along the tube axis (A1) when in use, the thickness (T) being smaller than the width (L2) of the groove (24).

[0037] Alternatively, the one or more catchers (51) can have a tapered cross-section such that the thickness (T) have reduced values at sections of the catchers (51) that are radially closer to the corresponding grooves (24) when in use with regard to the tube axis (A1), and thus the catchers (51) can be easily received by the grooves (24).

[0038] In accordance with the discussions above, it can be contemplated that the tool (5) is arranged to be suitable for use in separating the fuel rail assembly (100) provided with the proposed fuel distributor (1), from a combustion engine. Referring to Fig.1 , the tool (5) can comprise one or more catchers (51) arranged for being received by the one or more respective grooves (24).

[0039] The tool (5) can comprise one or more handles (52), such that the tool (5) can be manually pulled at the handle (52) in a first direction (z) in which the one or more catchers (51) retain engagement with the respective one or more grooves (24). The presence of such one or more handles (52) facilitates the work and provides an enhanced comfort to an operator or technician. As exemplified in Fig.1 , the one or more handles (52) can be provided at the second side of the bar (53) that is away from the fuel distributor (1) when in use. So, the extent of required space around the tool (5) is reduced and the working space is rendered more compact. Within the context of the present disclosure, in particular when directed to the tool (5), the word “use” corresponds to engagement between the one or more catchers (51) and respective one or more grooves (24), and / or to the process of separating a fuel rail assembly (100) that includes the proposed fuel distributor (1), from a combustion engine body.

[0040] In accordance with the considerations discussed above, the present disclosure proposes a kit that comprises any of the possible embodiments of the proposed fuel distributor (1). The kit further comprises one or more tools (5) comprising one or more catchers (51), that are arranged for engaging to the one or more grooves (24), by being received by the one or more grooves (24).

[0041] Along the tube axis (A1), a value of a thickness (T) of the one or more catchers (51) can have a smaller value when compared to the width (L2) of the one or more grooves (24). For instance, a ratio of the thickness (T) to the width (L2) can be 0.9 or lower, 0.8 or lower, 0.7 or lower, 0.6 or lower, 0.5 or lower, or even 0.4 or lower. Smaller values of the ratio of thickness (T) to the width (L2) provide easier alignment and engagement between the one or more catchers (51) and the respective one or more grooves (24).

[0042] Alternatively, or furthermore, the one or more catchers (51) can have a tapered crosssection; such that the thickness (T) has reduced (that is, decreasing) values at sections of the catchers (51) that are radially closer to the corresponding grooves (24), when the tool (5) is in use. For instance, when in use, at zones where a catcher (51) is in mechanical contact with a respective groove (24), a ratio of the thickness (T) to the width (L2) can be 0.9 or lower, 0.8 or lower, 0.7 or lower, 0.6 or lower, 0.5 or lower, or even 0.4 or lower. Smaller values of the ratio of thickness (T) to the width (L2) provide easier alignment and engagement between the one or more catchers (51) and the respective one or more grooves (24). Above-discussed features relevant to the embodiments of the proposed fuel distributor

[0043] (1) and tool (5), greatly facilitates the process of separation of a fuel rail assembly (100) that is equipped with the proposed fuel distributor (1), from a corresponding engine block. By separating a fuel rail assembly (100) that is equipped with the proposed fuel distributor (1), from a corresponding engine block; fixing members (3) such as U-clips that fix fuel injectors (10) to respective injector cups (2) can be removed by radially pulling the fixing members (3) with regard to an injector cup axis (A) of the injector cup

[0044] (2). So, the fuel injectors (10) can be easily separated from respective injector cups (2), notwithstanding whether there is sufficient radial space around the fixing member (3) is available for removal of the same when the fuel rail assembly (100) is attached to an engine body. Hence, the fuel distributor (1) proposed herein eliminates architectural structure-based difficulties in separation of a fuel rail assembly (100) from an engine body.

[0045] Reference list:

[0046] 1 fuel distributor

[0047] 2 injector cup

[0048] 20 opening

[0049] 21 tube

[0050] 22 end cap

[0051] 23 head portion

[0052] 24 groove

[0053] 25 mounting bracket

[0054] 3 fixing member

[0055] 4 retaining arm

[0056] 5 tool

[0057] 51 catcher

[0058] 52 handle

[0059] 53 bar

[0060] 10 fuel injector

[0061] 11 nozzle tip

[0062] 15 first end

[0063] 100 fuel rail assembly

[0064] A injector cup axis

[0065] A1 tube axis

[0066] L1 a length

[0067] L2 a width

[0068] T a thickness g gravity vector z first direction

Claims

CLAIMS1. A fuel distributor (1) for a fuel rail assembly (100) for combustion engines, the fuel distributor (1) comprises one or more injector cups (2) provided on a tube (21) for communicating fuel from the tube (21) to respective fuel injectors (10) when the fuel injectors (10) are engaged to the one or more injector cups (2); the fuel distributor (1) is provided with end caps (22) at both ends of the tube (21) with regard to a tube axis (A1); the one or more end caps (22) are arranged to, when in use, axially extend from the tube (21) at a length (L1) along the tube axis (A1); characterized in that, the one or more end caps (22) comprise one or more circumferential grooves (24) provided around the tube axis (A1); the grooves (24) have a width (L2) along the tube axis (A1); and a ratio of the width (L2) to the length (L1) is 0.1 or greater.

2. The fuel distributor (1) according to claim 1 ; wherein the ratio of the width (L2) to the length (L1) is 0.3 or greater.

3. The fuel distributor (1) according to anyone of claims 1 or 2; wherein the ratio of the width (L2) to the length (L1) is 0.5 or greater.

4. The fuel distributor (1) according to anyone of claims 1 to 3; wherein the end cap (22) comprises a head portion (23) at an axially distal end with regard to the tube (21); and when compared to the groove (24), the head portion (23) has a greater diameter than a diameter of the groove (24) in radial directions with regard to the tube axis (A1).

5. The fuel distributor (1) according to anyone of claims 1 to 4, wherein in a kit that further comprises one or more tools (5) comprising one or more catchers (51) that are arranged for being received by the one or more grooves (24).

6. The fuel distributor (1) according to claim 5; wherein, when in use, along the tube axis (A1), a value of a thickness (T) of the one or more catchers (51) of the tool (5) in the kit have a smaller value when compared to the width (L2) of the one or more grooves (24).

7. The fuel distributor (1) according to anyone of claims 5 or 6; wherein, the one or more catchers (51) of the tool (5) in the kit have a tapered cross-section such that the thickness (T) has reduced values at sections of the catchers (51) that are radially closer to the corresponding grooves (24) when in use with regard to the tube axis (A1).

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