Fuel supply device

Abstract

The invention relates to a fuel supply device comprising: - a connection interface (2), - a tube (4) connected to the connection interface using a connection device, in which the connection device comprises: - a nozzle (6) comprising a body (7) and a head (8) comprising a front end (9) and a rear end (10), - a nut (11) comprising a threaded nut portion (12), - a ring (16) located around the body (7) of the nozzle (6) and inside the nut (11), the ring (16) comprising a first surface (17) in contact with the rear end (10), and a second surface (18) in contact with the bearing surface (15), in which the rear end (10) of the head (8) and the first surface (17) are configured to form a ball joint, and in which the channel comprises a guide surface (19). Figure for abstract: Fig. 2

Description

Title of the invention: Fuel supply device Technical field

[0001] The invention relates to the field of fuel supply devices, in particular in the field of internal combustion engines and fuel cells. The fuel may be a fuel intended to power an internal combustion engine or a reducing reagent intended to power a fuel cell. Technological background

[0002] The fuel supply devices of the state of the art, for example those in the field of internal combustion engines, comprise a common rail having a main chamber, and a connection interface comprising a flow channel opening into the main chamber and intended to be connected to a tube for transporting fuel.

[0003] In order to connect the tube and the connection interface, a connection device is provided comprising a tip and a nut. The tip comprises a body fixed to one end of the tube and a head comprising a front end cooperating with the flow channel and a rear end. The nut comprises a threaded portion cooperating with the threaded portion of the connection interface, and a bearing portion cooperating with the rear end of the head of the tip so as to fix the head in the flow channel.

[0004] However, this type of connection does not allow the assembly between the tube and the connection interface to be optimally sealed because the connection does not take into account manufacturing tolerances which may result in geometric defects such as coaxiality defects between the different elements. Summary

[0005] An idea underlying the invention is to improve the sealing of the connection between the tube for transporting fuel and the connection interface by taking into account manufacturing tolerances which may lead to geometric defects, for example coaxiality, in particular between the end piece and the flow channel.

[0006] According to one embodiment, the invention provides a fuel supply device comprising: - a connection interface comprising a flow channel for the fuel, and a threaded interface portion, - a tube for transporting fuel connected to the connection interface using a connection device, the tube comprising a nozzle having a body fixed to one end of the tube and a head comprising a front end cooperating with the flow channel of the connection interface and a rear end, the tip being configured to conduct fuel from the tube to the flow channel, in which the connecting device comprises - a nut comprising a threaded nut portion cooperating with the threaded interface portion so as to allow rotation of the nut relative to the connection interface along a screwing axis, and a bearing portion connected to the threaded nut portion and comprising a bearing surface, the end piece passing through the bearing portion with radial clearance, the head being located inside the nut, - a ring located around the body of the end piece and inside the nut, an outside diameter of the ring being strictly less than an inside diameter of the nut so as to define a radial clearance between the ring and the nut, the ring comprising a first surface facing towards and in contact with the rear end of the head, and a second surface in contact with the bearing surface, the second ring surface and the bearing surface being configured to form a connection comprising a degree of translational connection along the screwing axis and degrees of freedom in translation in the plane normal to the screwing axis, in which the rear end of the head and the first surface are configured to form a ball joint connection, and wherein the flow channel has a guide surface formed about an axis of revolution, the guide surface and the front end of the head of the bit being configured to guide the bit to a position in which the front end of the head is in contact with the guide surface all about the axis of revolution, when screwing the nut onto the connection interface.

[0007] Thanks to these characteristics, the ring is arranged so as to be able to move in the plane normal to the screwing axis in order to compensate for a coaxiality defect between the nut, the connection interface and the end piece. In addition, the ball joint between the head of the end piece and the first bearing surface makes it possible to compensate for the non-alignment between the tube and the connection interface by allowing the tube end piece to tilt relative to the connection interface. The ball joint and the ring thus make it possible to improve the sealing of the connection between the tube and the connection interface.

[0008] According to embodiments, such a fuel supply device may comprise one or more of the following features.

[0009] According to one embodiment, the threaded interface portion is formed on an outer surface of the connection interface. Thus, the threaded nut portion surrounds the threaded interface portion.

[0010] According to another embodiment, the threaded interface portion is formed in an inner surface of the connection interface. Thus, the threaded interface portion surrounds the threaded portion of the nut.

[0011] According to one embodiment, the axis of revolution around which the guide surface is formed is parallel to the screwing axis, preferably coincident with the screwing axis, within geometric manufacturing tolerances.

[0012] According to one embodiment, said end piece is coaxial with the axis of revolution of the guide surface.

[0013] According to one embodiment, the rear end of the head is produced in the form of a spherical zone.

[0014] A spherical area is the portion of the surface of a sphere between two parallel planes that intersect the sphere.

[0015] According to one embodiment, the first surface of the ring is produced in the form of a spherical zone so that the contact between the first surface and the rear end is surface-like.

[0016] According to one embodiment, the first surface of the ring is made in the form of a truncated cone of revolution so that the contact between the first surface and the rear end is linear all around the head of the tip.

[0017] According to one embodiment, the bearing surface of the nut and / or the second surface of the ring is / are flat, preferably the bearing surface and the second surface are flat.

[0018] According to one embodiment, the front end of the head of the nozzle and the guide surface of the flow channel are configured to form a ball joint.

[0019] According to one embodiment, the front end of the head of the tip is produced in the form of a spherical zone.

[0020] According to one embodiment, the guide surface of the flow channel is produced in the form of a truncated cone of revolution.

[0021] According to one embodiment, an inner diameter of the support portion of the nut is strictly less than the inner diameter of the nut.

[0022] According to one embodiment, an internal diameter of the support portion of the nut is strictly greater than an external diameter of the body of the end piece.

[0023] According to one embodiment, the front end and the rear end of the head define at their intersection a maximum external diameter of the head, the maximum external diameter of the head being strictly greater than an internal diameter of the ring.

[0024] According to one embodiment, the axis of revolution around which the guide surface is formed is substantially parallel to the screwing axis, within geometric manufacturing tolerances. Brief description of the figures

[0025] The invention will be better understood, and other aims, details, characteristics and advantages thereof will appear more clearly during the following description of several particular embodiments of the invention, given solely for illustrative and non-limiting purposes, with reference to the appended drawings.

[0026] [Fig-1] [Fig.l] represents an exploded view of a power supply device fuel according to one embodiment.

[0027] [Fig.2] [Fig.2] is a sectional view of the connection device attached to the connection interface according to a first embodiment.

[0028] [Fig.3] [Fig.3] is a view of detail III of [Fig.2] of the connections of the ring with the nut and the head of the end piece.

[0029] [Fig.4] [Fig.4] is a sectional view of the connection device attached to the connection interface according to a second embodiment.

[0030] [Fig.5] [Fig.5] is a view of detail V of [Fig.4] of the connections of the ring with the nut and the head of the end piece.

[0031] [Fig.6] [Fig.6] is a sectional view of the connection device attached to the connection interface according to a third embodiment. Description of the embodiments

[0032] [Fig.l] shows a fuel supply device 1 comprising a connection interface 2 which is for example formed in the case of an internal combustion engine in a common rail (not shown). This connection interface 2 is provided with a flow channel 3 for the fuel. The fuel supply device 1 also comprises at least one tube 4 for transporting the fuel, which connects for example a tank to the common rail. The tube 4 is thus connected to the connection interface 2 in order to circulate the fuel from one point to another in the system which may be for example an internal combustion engine or a fuel cell. The connection interface 2 comprises on an outer surface a threaded interface portion 13.

[0033] The tube 4 and the connection interface 2 are connected to each other using a connection device 5 which provides both fixing and sealing in the connection between the tube 4 and the connection interface 2. The connection device 5 will be described in more detail below.

[0034] Figures 2 and 4 show more particularly the connection device 5 assembled to the connection interface 2 and to the tube 4 (not shown in Figures 2 and 4).

[0035] The tube 4 comprises a nozzle 6 comprising a body 7 and a head 8. The head 8 comprises a front end 9 cooperating with the flow channel 3 of the connection interface 2 and a rear end 10. The nozzle 6 is configured to conduct the fuel from the tube 4 to the flow channel 3. According to one embodiment, the end piece 6 and the remaining portion of the tube 4 are formed in one piece. According to another embodiment, the end piece 6 and the remaining portion of the tube 4 are two separate pieces fixed to each other.

[0036] The tip 6 comprises a tip channel 20 which passes right through the head 8 and the body 7.

[0037] The end channel 20 makes it possible to create continuity in the fuel path between the tube 4 and the flow channel 3.

[0038] The flow channel 3 further comprises a guide surface 19 formed around an axis of revolution, which in the schematic case illustrated in [Fig.2] coincides with the screwing axis. The guide surface 19 forms the inlet portion of the flow channel 3 for the end piece 6. The guide surface 19 and the front end 9 of the head 8 are in fact configured to guide the end piece 6 to a position in which the front end 9 of the head 8 is in contact with the guide surface 19 all around the axis of revolution, when screwing the nut 11 onto the connection interface 2 in order to seal the connection between the end piece 6 and the connection interface 2.

[0039] The connection device 5 also comprises a nut 11 comprising a threaded nut portion 12 cooperating with the threaded interface portion 13 so as to allow rotation of the nut 11 relative to the connection interface along a screwing axis. Thus, the nut 11 is screwed all around the connection interface 2. The nut 11 further comprises a bearing portion 14 connected to the threaded nut portion 12 and comprising a bearing surface 15. The bearing portion 14 comprises an orifice 23 in which the body 7 of the end piece 6 passes through the nut 11. In order to ensure radial clearance between the nut 11 and the body 7 of the end piece 6, the diameter of the orifice 23 is greater than the outside diameter of the body 7. The head 8 is located inside the threaded nut portion 12.

[0040] The connecting device 5 finally comprises a ring 16 located around the body 7 of the end piece 6 and inside the nut 11. In addition, in order to ensure radial clearance between the ring 16 and the nut 11, the outside diameter of the ring 16 is smaller than the inside diameter of the nut 12. The ring 16 comprises a first surface 17 in contact with the rear end 10 of the head 8, and a second surface 18 in contact with the bearing surface 15 of the nut 11. The ring 16 thus acts as an intermediary between the end piece 6 and the nut 11 so that when the nut 11 is screwed onto the connection interface 2 and the bearing surface 15 presses against the second surface 18, the tightening force is transmitted to the head 8 of the end piece 6.

[0041] In the embodiments illustrated in Figures 3 and 5, the second surface 18 of the ring 16 and the bearing surface 15 are both planar and thus form a bearing-plane connection comprising a degree of translational connection along the screwing axis. and degrees of freedom in translation in the plane normal to the screwing axis. Thus, the ring 16, due to its dimension smaller than the nut 11 and its support-plane connection, can move in the plane normal to the screwing axis in order to assist in the positioning of the head 8 of the end piece 6 in the flow channel 3, taking into account any coaxiality defects.

[0042] Furthermore, the tube 4 is not necessarily in the screwing axis before being connected to the connection interface 2. It is therefore advantageous to provide degrees of freedom in rotation for the end piece 6 during its assembly between the nut 11 and the connection interface 2 in order to avoid excessively stressing the connection between the end piece 6 and the tube 4. For this, the connection between the rear end 10 of the head 8 and the first surface 17 of the ring is a ball joint.

[0043] In the first embodiment illustrated in particular in [Fig. 3], the rear end 10 is produced in the form of a spherical zone while the first surface 17 is produced in the form of a truncated cone of revolution. The connection between the first surface 17 and the rear end 10 is therefore a cone / sphere connection which is one of the forms of a ball joint connection.

[0044] In the second embodiment illustrated in particular in [Fig. 5], the rear end 10 is produced in the form of a spherical zone while the first surface 17 is produced in the form of a spherical zone. The connection between the first surface 17 and the rear end 10 is therefore a sphere / sphere connection which is one of the forms of a ball joint connection.

[0045] It has also been found that, to further promote this inclination of the end piece 6 relative to the connection interface 2 in the event of non-alignment of the tube 2, it is also advantageous to provide that the connection between the front end 9 of the head 8 and the guide surface 19 of the connection interface 2 is a ball joint.

[0046] For this purpose and as visible in figures 2 and 4, the front end 9 is produced in the form of a spherical zone while the guide surface is produced in the form of a truncated cone of revolution. The connection between the first surface 17 and the rear end 10 thus forms a cone / sphere connection which is one of the forms of a ball joint connection.

[0047] Thus, the connection device makes it possible on the one hand to correct any coaxiality defects and on the other hand to correct geometric defects, for example an inclination of the tube 4 relative to the connection interface 2.

[0048] [Fig. 6] represents a third embodiment which is distinguished from the first embodiment of [Fig. 2] by the shape of the nut 11 and the connection interface 2. Indeed, unlike [Fig. 2], the threaded interface portion 13 is formed in an internal surface of the connection interface 2. Thus in this embodiment, the nut 11 is screwed via the threaded nut portion 12 inside the connection interface 2 so that it is the interface threaded portion 13 which surrounds the nut threaded portion 12.

[0049] Although the invention has been described in connection with several particular embodiments, it is quite obvious that it is in no way limited thereto and that it includes all the technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.

[0050] The use of the verb “comprise”, “comprise” or “include” and its conjugated forms does not exclude the presence of other elements or other steps than those stated in a claim.

[0051] In the claims, any reference sign in parentheses cannot be interpreted as a limitation of the claim.

Claims

Claims

1. Fuel supply device (1) comprising: - a connection interface (2) comprising a flow channel (3) for the fuel, and a threaded interface portion (13), - a tube (4) for transporting fuel connected to the connection interface (2) using a connection device (5), the tube comprising a nozzle (6) comprising a body (7) and a head (8) comprising a front end (9) cooperating with the flow channel (3) of the connection interface (2) and a rear end (10), the nozzle (6) being configured to conduct the fuel from the tube (4) to the flow channel (3), and in which the connection device (5) comprises: - a nut (11) comprising a threaded nut portion (12) cooperating with the threaded interface portion (13) so as to allow rotation of the nut (11) relative to the connection interface (2) along a screwing axis, and a bearing portion (14) connected to the threaded nut portion (12) and comprising a bearing surface (15), the end piece (6) passing through the bearing portion with radial clearance, the head (8) being located inside the nut (11), - a ring (16) located around the body (7) of the end piece (6) and inside the nut (11), an outside diameter of the ring (16) being strictly less than an inside diameter of the nut (11) so as to define a radial clearance between the ring (16) and the nut (11), the ring (16) comprising a first surface (17) facing and in contact with the rear end (10) of the head (8), and a second surface (18) in contact with the bearing surface (15), the second ring surface (18) and the bearing surface (15) being configured to form a connection comprising a degree of translational connection along the screwing axis and degrees of freedom in translation in the plane normal to the screwing axis, in which the rear end (10) of the head (8) and the first surface (17) are configured to form a ball joint connection, and in which the flow channel (3) comprises a surface of guide (19) formed around an axis of revolution,the guide surface (19) and the front end (9) of the head (8) of the tip (6) being configured to guide the tip (6) to a position in which the front end (9) of the head (8) is in contact with the surface of, guide (19) all around the axis of revolution, when screwing the nut (11) onto the connection interface (2), the front end (9) of the head (8) of the end piece (6) and the guide surface (19) of the flow channel (3) being configured to form a ball joint.

2. Fuel supply device (1) according to claim 1, wherein the rear end (10) of the head (8) is made in the form of a spherical area.

3. A fuel supply device (1) according to claim 2, wherein the first surface (17) of the ring (16) is formed as a spherical area so that the contact between the first surface (17) and the rear end (10) is surface.

4. Fuel supply device (1) according to claim 2, wherein the first surface (17) of the ring (16) is made in the form of a truncated cone of revolution so that the contact between the first surface (17) and the rear end (10) is linear all around the head (8) of the nozzle (6).

5. Fuel supply device (1) according to one of claims 1 to 4, wherein the bearing surface (15) of the nut (11) and / or the second surface (18) of the ring (16) is / are flat.

6. Fuel supply device (1) according to one of claims 1 to 5, wherein the front end (9) of the head (8) of the nozzle (6) is made in the form of a spherical zone.

7. Fuel supply device (1) according to one of claims 1 to 6, wherein the guide surface (19) of the flow channel (3) is designed in the form of a truncated cone of revolution.

8. Fuel supply device (1) according to one of claims 1 to 7, in which the front end (9) and the rear end (10) of the head (8) define at their intersection a maximum external diameter of the head (8), the maximum external diameter of the head (8) being strictly greater than an internal diameter of the ring (16).

9. A fuel supply device (1) according to one of claims 1 to 8, wherein the interface threaded portion (13) is formed on an outer surface of the connection interface (2) or on an inner surface of the connection interface (2).

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