IMPLEMENTING METHOD

The present invention relates to a motor vehicle liquid circuit filling device. The invention also relates to a filling assembly comprising such a filling device and a filling tool. The invention also relates to a liquid tank and to a motor vehicle comprising such a filling device. The invention also relates to a method for implementing such a filling device.

In a motor vehicle, several systems are equipped with a liquid circuit: the engine, transmission, power steering, cooling system, braking system, etc. Each of these systems is provided with a liquid tank, either internally such as the engine oil reservoir for example, typically situated at the bottom of the engine, or externally such as the cooling liquid tank for example.

At the factory of the motor vehicle manufacturer the liquid circuit is filled by an operator using the tool provided for that purpose, for example a quick-fill gun inserted into the liquid tank. In practice, the operator operates the tool according to a filling sequence that includes specific cycles. First of all, the operator performs a cycle under vacuum in order to purge out any air present in the circuit. Next, the operator performs a cycle under pressure to fill the circuit. Finally, the operator performs a suction cycle in order to adjust the final level of liquid in the circuit.

During the suction cycle, the final liquid level is generally adjusted at the end of the filling tool, and is therefore dependent on the length of this tool. This being so, specifications force the designer of the tank to provide a specific distance between the neck of the tank, more specifically the upper rim thereof, and the maximum level of liquid in the tank.

However, there are other design considerations that may be involved, such as the mechanical strength of the tank and the expansion volume of the liquid circuit, which corresponds to the volume situated above the maximum level of liquid in the tank. This expansion volume is defined with precision, and is dependent on the volume of the liquid circuit and on the thermal expansion of the liquid.

When the manufacturing plant is designed to assemble a single type of vehicle, then just one filling tool will suffice. When several types of vehicles are assembled on the same assembly line, the operator may need to use a number of filling tools of different lengths, alternatively an adjustable single tool, with risks of error.

WO-A-2014/028500 describes a device for filling a liquid circuit, more specifically a fuel tank. The device comprises a guide member of the deflector type, inserted removably into a filling pipe leading to the tank. The guide member comprises two tubular parts connected by an elastic elbow. This guide member is designed to receive and guide a tank filling tool, following the curvature of the pipe. The fuel tank can be filled correctly even if the filling tool is not in sealed contact with the guide member.

DE-U-20 201 1 100846 describes another device for filling a liquid circuit, more specifically a urea tank. The device comprises a filling pipe, an insert positioned in the pipe, a shut-off cap, and numerous other component parts. This device is designed to prevent the tank from being filled by an incorrect filling tool supplying a liquid other than urea. Furthermore, this device is of complex construction.

FR-A-2 953 792 describes another device for filling a liquid circuit. The device comprises a filling pipe belonging to a liquid tank and a member for setting the level of the liquid in the tank. This member can be positioned downstream of the pipe or in the pipe. This member comprises an upstream part of frustoconical shape and a downstream part of cylindrical shape. In order to fill the tank, a filling tool is positioned resting in the frustoconical part of the member. In other words, sealing between the member and the tool is achieved on a conical section, which is not entirely satisfactory.

The object of the present invention is to propose an improved filling device seeking to overcome the abovementioned disadvantages.

To this end, one subject of the invention is a device for filling a liquid circuit for a motor vehicle, the filling device being suitable for receiving a filling tool and comprising: an inlet opening; a pipe that extends in the liquid circuit downstream from the inlet opening and which includes a wall having a first inner diameter; and a guide member that is positioned in the pipe and includes a cylindrical wall delimiting a channel for receiving the filling tool along a cylindrical sealing section, this channel having a second inner diameter smaller than the first inner diameter of the pipe. The filling device is characterized in that the channel extends as far as a downstream orifice formed in the guide member and positioned at a maximum desired fill level in the liquid circuit, the guide member forming a means of extending the filling tool in order to adjust the final level of liquid in the liquid circuit to the maximum fill level by coming flush with the downstream orifice in the pipe.

Thus, the invention makes it possible to simplify the filling of the liquid circuit, and the design of the tool, of the circuit and of the tank. The guide member makes it easier to insert the filling tool into the device and then to carry out the filling sequence. After sucking out the excess liquid, the maximum fill volume will be defined by the downstream orifice situated at the end of the guide member. Thus there is no need to design the tank by adapting the maximum fill volume to suit the length of the filling tool. One single standard filling tool of defined length can be used regardless of the position of the maximum liquid level in the tank belonging to the liquid circuit. Furthermore, sealing over a cylindrical section is more reliable than sealing over a conical section.

According to other advantageous features of the invention, considered in isolation or in combination:

- The guide member includes an upstream orifice that has a gradual reduction in diameter until it reaches the second inner diameter, that upstream orifice being configured to guide the filling tool into the channel.

- The guide member is of one piece.

- The guide member is fastened to the wall of the pipe by welding.

- The guide member is fastened to the wall of the pipe by clipping.

- The guide member is fastened to the wall of the pipe by pinching.

- The guide member is integral with the wall of the pipe.

- The guide member comprises a body and a tubular extension together delimiting the channel, the tubular extension being formed protruding at a downstream end of the body.

- The guide member includes an inner sealing gasket positioned in the channel and provided to grip the filling tool.

Another subject of the invention is a filling assembly, comprising a filling device as mentioned hereinabove; and a filling tool provided to be inserted into the filling device in order to fill the liquid circuit. The filling tool includes a head inserted into the channel to fill the liquid circuit up to a maximum fill level flush with the downstream orifice of the guide member.

For preference, the filling tool also comprises an outer sealing gasket fitted against the wall of the channel, notably when the guide member has no internal sealing gasket positioned in the channel.

Another subject of the invention is a liquid tank for a motor vehicle, comprising a filling device as mentioned hereinabove.

In the particular case of a brake fluid tank, the invention makes it possible to obtain a satisfactory compromise, at the time of design, between optimized expansion volume and reduced size.

Another subject of the invention is a motor vehicle comprising a filling device as mentioned hereinabove.

Another subject of the invention is a method for implementing a filling device as mentioned hereinabove, in other words a filling method. The method comprises the following successive steps: inserting a filling tool through the inlet opening, then into the channel of the guide member along the cylindrical sealing section; and actuating the filling tool to carry out a filling sequence of the liquid circuit, the final level of liquid in the liquid circuit being adjusted to the maximum fill level flush with the downstream orifice of the guide member in the pipe.

More specifically, the filling sequence comprises a vacuum cycle for purging out any air present in the circuit; a pressurized cycle to fill the circuit; and a suction cycle for adjusting the final liquid level in the circuit.

The invention will be better understood from reading the description which follows, given solely by way of non-limiting example and made with reference to the attached drawings in which:

- figure 1 is a partial section of a filling device not in accordance with the invention;

figure 2 is a section similar to figure 1 showing a filling device according to the invention; and

figure 3 is a section similar to figures 1 and 2 showing an alternative form of filling device according to the invention.

For the sake of simplification, the various elements have been depicted partially in figures 1 to 3.

Figure 1 depicts an automobile system 101 comprising a liquid circuit 102 which includes a liquid tank 103. The liquid circuit 102 can be filled using a filling assembly 105 comprising, on the one hand, a filling device 1 10 incorporated into the tank 103 and, on the other hand, a filling tool 120 designed to be inserted into the filling device 1 10. The device 1 10 comprises a neck 130 and an internal pipe 140 for conveying liquid into the circuit 102. The tool 120 is positioned at the neck 130 and penetrates the pipe 140.

The tank 103 needs to be designed to adapt its expansion volume to suit the length of the filling tool 120. This constraint may have implications regarding the shape of the tank 103, for example regarding the radius of curvature of the walls thereof, and therefore the mechanical strength thereof. For certain applications such as air separator bottles, in order to maintain sufficient strength, it may be necessary to increase the wall thickness of the tank 103 or provide additional reinforcing ribs. That increases the weight of the reservoir 103 and may disturb the flow of fluids (air and liquid).

Figure 2 depicts an automobile system 1 comprising a liquid circuit 2 which includes a liquid tank 3. A filling assembly 5 according to the invention is used to fill the circuit 2 with liquid L. This assembly 5 comprises, on the one hand, a filling device 10 according to the invention, advantageously incorporated into the tank 3 and, on the other hand, a filling tool 20 designed to be inserted into the filling device 10. The filling tool 20 comprises a hollow stem 21 provided with a head 22 and delimiting an internal channel 24 for the flow of liquid L. The head 22 is slightly wider than the rest of the stem 21 and has an outer diameter D20. The tool 20 comprises a body 26 depicted in part for the sake of simplification, arranged around the stem 21. The head 22 comprises an external annular groove 27 and an external annular sealing gasket 28 housed in the groove 27.

The device 10 comprises a neck 30, an internal pipe 40 for conveying liquid L into the circuit 2, and a guide member 50 which is arranged in the pipe 40 and which delimits an internal channel 60 for accepting the tool 20. The device 10 is roughly centered on an axis XI O.

The neck 30 comprises an external screw thread 32 for screwing on a closure cap, not depicted. The neck 30 delimits a housing 34 for accepting the tool 20. The neck 30 comprises a throat 36 connecting it with the pipe 40. The throat 36 has a curved shape and a diameter that decreases toward the pipe 40. The neck 30 comprises an opening 38 of circular shape, defining the inlet of the device 10, of the tank 3, and therefore of the circuit 2. The opening 38 is the zone of the device 10 situated furthest toward the outside. The flow of liquid L into the device 10 is directed away from this opening 38, in a direction referred to as a downstream direction.

The pipe 40 extends downstream from the neck 30, particularly downstream from the opening 38. The pipe 40 comprises a cylindrical inner wall 42 having an inner diameter D40. The wall 42 delimits a channel 44 for the flow of liquid L.

The member 50 comprises a body 51 and extension 52, each of tubular shape. The member 50 is elongate between an upstream end 53 and a downstream end 54. The extension 52 is formed so that it protrudes from the body 51 at the downstream end 54. The body 51 constitutes most of the material of the member 50, as compared with the extension 52. The body 51 has an outer diameter which is greater than the outer diameter of the extension 52. The body 51 comprises a cylindrical outer wall 55. The wall 55 of the member 50 is fixed to the wall 42 of the pipe 40, preferably by welding. As an alternative, the member 50 may be fixed in the pipe 40 by any suitable means, for example by clipping or pinching.

The member 50 further comprises a cylindrical inner wall 56 which extends along the body 51 and the extension 52. The wall 56 delimits the channel 60 that accommodates the tool 20 and along which the liquid L flows into the circuit 2. In other words, the body 51 and the extension 52 together delimit the channel 60 in the member 50. The channel 60 has an inner diameter D60 less than the inner diameter D40 of the pipe 40 and slightly greater than the outer diameter D20 of the tool 20. The channel 60 extends between an upstream orifice 57 and a downstream orifice 58 which are formed in the member 50. More specifically, the orifice 57 is formed at the end 53 of the member 50 in the body 51 and the orifice 58 is formed at the end 54 of the member 50 in the extension 52. The orifice 57 has a roughly conical shape, with a gradual reduction in diameter until it reaches the diameter D60.

The member 50 is preferably made of one piece. In other words, the member 50 is not made up of several components assembled with one another. The channel 60 extends uninterrupted between the orifices 57 and 58.

The method of implementing the device 10 comprises the following successive steps: a first step that consists in inserting the tool 20 through the opening 38 then into the channel 60 of the member 50, then a second step consisting in actuating the tool 20 in order to carry out a sequence of filling the liquid circuit 2.

In the first step, the head 22 of the tool 20 passes through the opening 38 and is then received in the orifice 57. The shape of the orifice 57 makes it easier for the head 22 to be inserted into the member 50, more specifically into the channel 60. In other words, the orifice 57 is configured to guide the tool 20 as far as and into the channel 60. At this stage, the channel 60 accepts the tool 20, defining by virtue of the sealing gasket 28 a cylindrical section 62 for sealing between the tool 20 and the member 50. More specifically, the sealing gasket 28 provides sealing between the head 22 of the tool 20 and the wall 56 of the channel 60 to prevent liquid L from rising back up to the opening 38 in the upstream direction. The sealing achieved in the channel 60 between the tool 20 and the member 50 at the cylindrical section 62 is more reliable than sealing that might be achieved at a conical section. The section 62 is defined whatever the position of the head 22 of the tool 20 in the channel 20.

In the second step, the filling sequence comprises a vacuum cycle for purging out the air present in the circuit 2; a pressurized cycle for filling the circuit 2 with liquid L; and a suction cycle for adjusting the final level of liquid L in the circuit 2. In particular, this final level is adjusted to the maximum level for liquid L in the tank 3 so as to obtain a predetermined expansion volume V. In the channel 44 of the pipe 40 the maximum level of liquid L lies flush with the orifice 58 of the member 50.

In practice, the member 50 forms a means of extending the filling tool 20 into the device 10. This extension is directed away from the opening 38, in the downstream direction. Instead of a length L1 defined between the downstream end of the tool 20 and the opening 38, a length L2 greater than the length L1 is defined between the orifice 58 and the opening 38. The member 50 is dimensioned such that the orifice 58 is positioned at the maximum desired fill level in the tank 3. At the end of the suction cycle, the liquid L is present in the circuit 2 in optimum quantity. The predetermined expansion volume V is defined above the maximum level for filling with liquid L.

Figure 3 depicts an alternative form of filling device 10, the component parts of which are comparable with those of figure 2 and bear the same numerical references. In this alternative form, the guide member 50 is formed integral with the wall 42 of the pipe 40, notably being molded as one therewith. Part of the wall 55 is separated from the wall 42 of the pipe 40 by a space 59. The devices 10 of figures 2 and 3 work in a similar way.

Moreover, the filling device 10 may be configured differently from figures 2 and 3 without departing from the scope of the invention.

As an alternative form which has not been depicted, the device 10 may be designed to fill a liquid circuit 2 that does not have a tank 3.

According to another alternative form that has not been depicted, the pipe 40 for conveying liquid into the circuit 2 may have a configuration different from figures 1 to 3, notably according to the configuration of the automobile system 1. For example, the pipe 40 may be more or less elongate and more or less wide. Furthermore, when the device 10 has no neck 30, the opening 38 may be formed directly at the inlet to the pipe 40.

In another alternative form which is not been depicted, the member 50 may have a different shape and different dimensions. For example, the member 50 may be devoid of an extension 52. In that case, the body 51 on its own delimits the channel 60 and the downstream orifice 58 of the channel 60 is formed directly in the body 51 . According to another example, the orifice 57 may have a different geometry.

According to another alternative form which is not been depicted, the member 50 may comprise an inner sealing gasket positioned in the channel 60 and designed to grip the tool 20 when the latter is inserted into the channel 60. In that case, the tool 20 is preferably devoid of an outer sealing gasket designed to collaborate with the wall of the channel. The inner sealing gasket then defines the cylindrical section 62 for sealing between the tool 20 and the member 50.

According to another alternative form which has not been depicted, the walls 42 and 55 may have different shapes, for example non-cylindrical shapes. In that case, the diameter D40 may be the minimum inside diameter of the pipe 40.

Whatever the embodiment, the channel 60 extends as far as a downstream orifice 58 formed in the guide member 50 and positioned at a maximum fill level desired in the liquid circuit 2. The guide member 50 forms a means of extending the filling tool 20 in order to adjust the final level of liquid L in the liquid circuit 2 to the maximum fill level flush with the downstream orifice 58 in the pipe 40. For preference, the guide member 50 is of one piece and secured to the wall 42 of the pipe 40 (by welding into the pipe 40 or directly by being molded as one with the pipe 40).

Furthermore, the technical features of the various embodiments and alternative forms mentioned hereinabove may all, or just some, be combined with one another. Thus, the filling device 10 can be adapted in terms of cost and functionality.