Patent Description:
It is known that in a fuel pump for a motor vehicle engine, a fuel pump actuator is provided in order to regulate the quantity of fuel flowing from the fuel pump to fuel injectors.

Fuel flowing through the fuel pump actuator brings impurities coming from different elements of the motor vehicle engine that are crossed by the fuel before arriving at the fuel pump actuator. These elements are for example the fuel tank, the fuel heater or other parts of the fuel pump. Impurities can also appear because of a low quality fuel.

These impurities are released from the actuator when fuel is conveyed from the actuator to the injection system of the motor vehicle engine. In order to prevent the impurities from entering the injection system, a filter, called JET filter, is provided in the fuel pump in a position close to the actuator. Thus, impurities are accumulated in the JET filter.

The accumulation of these impurities impacts the functioning of the JET filter, which must be replaced by a new one when the quantity of accumulated impurities is important.

Nevertheless, in some fuel pump configurations, the JET filter is placed in a position that is hardly accessible by using conventional tools. So, its removal from the fuel pump is difficult. In addition, by using conventional tools, a risk of introducing metallic particles inside the injection system exits.

Accordingly, it is an object of the present invention to resolve the above-mentioned problem in providing a kit for replacing a JET filter arranged in an engine fuel pump, the JET filter being placed on a lateral wall of a fuel pump cavity. the kit comprising an extractor for extracting said JET filter, a pushing rod for fitting a JET filter in the engine fuel pump, and a centering guide shaped to cooperate with the extractor and the pushing rod.

The centering guide is configured to be partially positioned in the cavity of the fuel pump. The centering guide comprises a main body including a cavity, wherein the cavity is shaped such that the JET filter can be extracted from the engine fuel pump by the extractor or can be pushed to the engine fuel pump by the pushing rod.

Thanks to the claimed kit, the JET filter is reached by the extractor when the extractor and the centering guide cooperate. Hence, the JET filter can be removed from the fuel pump.

In embodiments, the extractor comprising a handle and a bar, wherein a first end of said bar comprises a threaded surface to engage the JET filter.

In an embodiment of the extractor, the bar is shaped to cooperate with the centering guide, the extractor being provided with a nut surrounding a portion of said bar.

In embodiments, the pushing rod comprising a handle and a bar, wherein a first end of said bar is shaped to push the JET filter to a final position in the engine fuel pump.

In an embodiment of the pushing rod the bar is shaped to cooperate with the centering guide.

In an embodiment of the centering guide, the main body comprises a cylindrically shaped portion.

In an embodiment of the centering guide, the main body comprises a trapezoidal prism shaped portion.

In an embodiment of the centering guide, the trapezoidal prism shaped portion comprises an entry orifice of the cavity of the main body, and the cylindrically shaped portion comprises an exit orifice of said cavity.

In an embodiment of the centering guide, the entry orifice is arranged on a face of the trapezoidal prism shaped portion, the face being substantially perpendicular to a longitudinal axis of the cavity.

In an embodiment of the centering guide, the longitudinal axis of the cavity is tilted in relation to a longitudinal axis of the cylindrically shaped portion.

The invention further extends to a method for extracting the JET filter arranged in the engine fuel pump by means of the present kit, the method comprising the steps of:.

The invention yet further extends to a method for fitting the JET filter in the engine fuel pump by means of the present kit, the method comprising the steps of:.

The present invention is now described by way of example with reference to the accompanying drawings in which:.

As shown in <FIG>, an engine fuel pump <NUM> comprises a cavity <NUM>, and a JET filter <NUM> placed on a lateral wall of the cavity <NUM>. The cavity <NUM> has advantageously a substantially cylindrical shape extending along an axial direction A. The axial direction A corresponds to longitudinal axis of the cavity (<NUM>).

The cavity <NUM> is in particular shaped to install therein a fuel pump actuator. The fuel pump actuator is further screwed to a first hole <NUM> and to a second hole <NUM> arranged on a face <NUM> of the engine fuel pump <NUM>, the face <NUM> being substantially perpendicular to the axial direction A of the cavity <NUM>. The first hole <NUM> and the second hole <NUM> are positioned next to the cavity <NUM>, on diagonally opposite positions between them.

The JET filter <NUM> advantageously has a substantially cylindrical shape. A base of the JET filter <NUM> comprises a grid allowing retaining impurities. A lateral wall of the JET filter <NUM> comprises a threaded surface.

The present invention relates to a JET filter extractor <NUM> and a centering guide <NUM> shaped to allow the extraction of the JET filter <NUM> from the fuel pump <NUM> when the extractor <NUM> and the centering guide <NUM> are used in combination. The present invention further relates to a JET filter pushing rod <NUM> shaped to allow the fitting of the JET filter <NUM> in the fuel pump <NUM> when used in combination with the centering guide <NUM>.

<FIG> shows a JET filter extraction assembly used in order to apply a method for extracting the JET filter <NUM> from the fuel pump <NUM>. The JET filter extraction assembly includes the extractor <NUM> and the centering guide <NUM>. The centering guide <NUM> is partially positioned in the cavity <NUM> of the fuel pump <NUM>, while the extractor <NUM> goes through the centering guide <NUM>.

<FIG> shows a JET filter insertion assembly used in order to apply a method for fitting the JET filter <NUM> in the fuel pump <NUM>. The JET filter insertion assembly includes the pushing rod <NUM> and the centering guide <NUM>. As in the JET filter extraction assembly, the centering guide <NUM> is partially positioned in the cavity <NUM> of the fuel pump <NUM>, while the pushing rod <NUM> goes through the centering guide <NUM>.

The method for extracting the JET filter <NUM> and the method for fitting the JET filter <NUM> will be later described.

Now, the extractor <NUM> will be described. The extractor <NUM> is shaped to engage the JET filter <NUM>, so that the JET filter <NUM> can be extracted from the fuel pump <NUM>. The extractor <NUM> comprises a handle <NUM>, a bar <NUM> and a nut <NUM>. The handle <NUM> and the bar <NUM> extend along an axial direction B of the extractor <NUM>. A length L1 of the extractor <NUM> is preferably comprised between <NUM> and <NUM>, preferably between <NUM> and <NUM>.

As shown in <FIG>, the handle <NUM> comprises a rough portion <NUM> placed between two substantially smooth portions <NUM>. The handle <NUM> is made of a metallic material, preferably of unalloyed steel. In particular, the handle <NUM> is made of a C35 unalloyed steel. Advantageously the handle <NUM> has a cylindrical shape. A diameter d1 of the handle <NUM> is comprised in a range between <NUM> and <NUM>, preferably between <NUM> and <NUM>.

The bar <NUM> comprises a first end <NUM>, a second end <NUM> and a central part <NUM>, the central part <NUM> being positioned between the first and the second ends <NUM>, <NUM>. The first end <NUM> comprises a threaded surface. On the contrary, a surface of the second end <NUM> and a surface of the central part <NUM> are substantially smooth.

Advantageously, the second end <NUM> and the central part <NUM> have a substantially circular section, a diameter d3 of the central part <NUM> being larger than a diameter d2 of the second end <NUM>. The diameter d3 is comprised in a range from <NUM> to <NUM>, preferably from <NUM> to <NUM>.

The bar <NUM> is made of a metallic material, preferably of unalloyed steel. In particular, the bar <NUM> is made of C45 unalloyed steel.

The handle <NUM> and the bar <NUM> are firmly attached between them. In particular, as shown in <FIG>, the second end <NUM> of the bar <NUM> is inserted inside a cavity <NUM> of the handle <NUM>, the cavity <NUM> extending along the axial direction B of the extractor <NUM>.

Advantageously, a screw connection is established between the handle <NUM> and the second end <NUM> of the bar <NUM>. Alternatively, the connection between the handle <NUM> and the second end <NUM> of the bar <NUM> is established by adhesive means. The adhesive means are, for example, a layer of glue between the surface of the second end <NUM> and a surface of the cavity <NUM>. The attachment can also be established by using both the screw connection and the adhesive means.

Preferably, the cavity <NUM> has a circular section having a diameter substantially equal to the diameter d2 of the second end <NUM>.

The nut <NUM> is coupled to the central part <NUM> of the bar <NUM>. In particular, the nut surrounds a portion of the central part <NUM>, said portion being close to the handle <NUM>. Preferably, the nut <NUM> comprises an external surface and an internal surface. The external surface is substantially hexagonal, while the internal surface is substantially circular.

The internal surface of the nut <NUM> is in contact with the surface of the central part <NUM>, a diameter of the internal surface of the nut <NUM> being substantially equal to a diameter of the central part <NUM>. Preferably, the nut <NUM> is a M5 type nut.

A length L2 of the first end <NUM> of the bar is comprised in a range between <NUM> and <NUM>, preferably between <NUM> and <NUM>.

The threaded surface of the first end <NUM> of the bar <NUM> is shaped to cooperate with the JET filter. In particular, said threaded surface is adapted to cooperate with the threaded surface of the lateral wall of the JET filter. Hence, the JET filter can be hooked in the bar <NUM> by screwing the bar <NUM> around the B-axis.

<FIG> shows the JET filter pushing rod <NUM>. The pushing rod <NUM> is used to push the JET filter <NUM> inside the cavity of the centering guide <NUM>, so that the JET filter <NUM> can be fitted in the fuel pump <NUM>. The pushing rod <NUM> comprises a handle <NUM> and a bar <NUM> extending along an axial direction C of the pushing rod <NUM>. Preferably, the handle <NUM> and the bar <NUM> constitute a single piece having a length L3 comprised in a range from <NUM> to <NUM>, preferably from <NUM> to <NUM>.

The pushing rod <NUM> is made of a metallic material, preferably of unalloyed steel. In particular, the handle <NUM> and the bar <NUM> are made of a C35 unalloyed steel.

The handle <NUM> comprises a rough portion <NUM> placed between two substantially smooth portions <NUM>. Advantageously the handle <NUM> has a cylindrical shape. A diameter d4 of the handle <NUM> is comprised in a range between <NUM> and <NUM>, preferably between <NUM> and <NUM>.

The bar <NUM> comprises a first end <NUM> and a main part <NUM>, the main part <NUM> being positioned between the first end <NUM> and the handle <NUM>. In particular, a length L4 of the main part <NUM> is comprised between <NUM> and <NUM>, preferably between <NUM> and <NUM>. A length L5 of the first end <NUM> is comprised between <NUM> and <NUM>, preferably between <NUM> and <NUM>.

As detailed in <FIG>, the first end <NUM> comprises a first portion <NUM> and a second portion <NUM>. The first portion <NUM> extends between the main part <NUM> and the second portion <NUM>, over a length L6 comprised in a range from <NUM> to <NUM>, preferably from <NUM> to <NUM>. A length L7 of the second portion <NUM> is comprised in a range from <NUM> to <NUM>, preferably from <NUM> to <NUM>.

A surface of the first end <NUM> and a surface of the main part <NUM> are substantially smooth.

Advantageously, the first end <NUM> and the main part <NUM> have a substantially circular section. A diameter d5 of the main part is in particular comprised between <NUM> and <NUM>, preferably between <NUM> and <NUM>.

A diameter d6 of the first portion <NUM> is larger than a diameter d7 of the second portion <NUM>. In particular, the diameter d5 of the first portion <NUM> is comprised in a range from <NUM> to <NUM>, preferably from <NUM> to <NUM>. The diameter d7 of the second portion <NUM> is in particular comprised in a range from <NUM> to <NUM>, preferably between <NUM> to <NUM>.

An extremity of the first end <NUM> comprises a hollow <NUM> adapted to accommodate the JET filter. The hollow <NUM> extends along a fraction of the first portion <NUM> and along the integrality of the second portion <NUM>. The hollow <NUM> includes a first part <NUM> and a second part <NUM>. Advantageously, the first part <NUM> has a substantially conical shape, while the second part <NUM> has a substantially cylindrical shape. A length L8 of the second part <NUM> is comprised in a range from <NUM> to <NUM>, preferably from <NUM> to <NUM>. A diameter d7 of the second part <NUM> is comprised in a range from <NUM> to <NUM>, preferably between <NUM> to <NUM>.

<FIG> shows the centering guide <NUM>. The centering guide <NUM> is shaped to guide the access of the extractor <NUM> to the JET filter <NUM> installed in the fuel pump <NUM>, as well as to guide the extraction of the JET filter <NUM> from the fuel pump <NUM> by means of the extractor <NUM>. The centering guide <NUM> is further shaped to guide the installation of the JET filter in the fuel pump <NUM> by means of the pushing rod <NUM>.

The centering guide <NUM> is made of a metallic material, preferably of unalloyed steel. In particular, the centering guide <NUM> is made of C35 unalloyed steel.

The centering guide comprises a main body <NUM> including a substantially cylindrically shaped portion <NUM> juxtaposed to a substantially trapezoidal prism shaped portion <NUM>.

The cylindrically shaped portion <NUM> is shaped to be inserted in the cavity <NUM> of the fuel pump <NUM> when the actuator is not installed therein. In particular, the cylindrically shaped portion <NUM> extends along an axial direction D over a length L9 comprised in a range from <NUM> to <NUM>, preferably from <NUM> to <NUM>. A diameter d8 of the cylindrically shaped portion <NUM> is comprised in a range from <NUM> to <NUM>, preferably from <NUM> to <NUM>.

The trapezoidal prism shaped portion <NUM> comprises a front face <NUM> opposite to a rear face <NUM>. The front face <NUM> and the rear face <NUM> are substantially perpendicular to the axial direction D. In particular, when the cylindrically shaped portion <NUM> is completely inserted in the cavity <NUM>, the rear face <NUM> contacts the face <NUM> of the fuel pump.

The trapezoidal prism shaped portion <NUM> further comprises an upper face <NUM> and a lower face <NUM>. The upper face <NUM> is substantially parallel to the axial direction D, while the lower face <NUM> is inclined in relation to the axial direction D. In particular, the lower face <NUM> forms an angle with the axial direction D comprised in a range from <NUM>° to <NUM>°, preferably from <NUM>° to <NUM>°.

The trapezoidal prism shaped portion <NUM> comprises a hole <NUM> extending from the front face <NUM> to the rear face <NUM> of the trapezoidal prism shaped portion <NUM>. A length L10 of the hole <NUM> corresponds to a distance between the front face <NUM> and the rear face <NUM>. In particular, the length L10 of the hole <NUM> is comprised between <NUM> and <NUM>, preferably between <NUM> and <NUM>.

The hole <NUM> allows the centering guide <NUM> to be screwed to the fuel pump <NUM>. In particular, the hole <NUM> is positioned in the trapezoidal prism shaped portion <NUM> such that when the cylindrically shaped portion <NUM> is inserted in the cavity <NUM>, the hole <NUM> lies in front of the first hole <NUM> arranged in the fuel pump <NUM>. Thus, a screw can be arranged between the hole <NUM> and the first hole <NUM> in order to fix the centering guide <NUM> to the fuel pump <NUM>.

The main body <NUM> further comprises a cavity <NUM> extending along the cylindrically shaped portion <NUM> and the trapezoidal prism shaped portion <NUM>. In particular, the cavity <NUM> extends along an axial direction E, the axial direction being perpendicular to the lower face <NUM>. The axial direction E corresponds to a longitudinal axis of the cavity. Advantageously the cavity <NUM> has a circular section.

The cavity <NUM> comprises a first portion <NUM> and a second portion <NUM>, a diameter d9 of the first portion <NUM> being larger than a diameter d10 of the second portion <NUM>. In particular, the diameter d9 of the first portion <NUM> is comprised in a range from <NUM> to <NUM>, preferably from <NUM> to <NUM>. The diameter d10 of the second portion <NUM> is comprised in a range from <NUM> to <NUM>, preferably between <NUM> and <NUM>.

The cavity <NUM> is shaped such that the bar <NUM> of the extractor <NUM> or the bar <NUM> of the pushing rod <NUM> can slide inside said cavity <NUM>. Thus, the diameters d9 and d10 are necessarily larger than the diameter d3 of the bar <NUM> and larger than the diameter d5 of the bar <NUM>. In particular, the diameter d <NUM> of the second portion <NUM> is slightly larger than the diameter d3, so that the central part <NUM> of the bar <NUM> remains in contact with a lateral wall of the second portion <NUM> when the extractor <NUM> is inserted in the cavity <NUM>.

As shown in <FIG>, an entry orifice <NUM> is arranged on the lower face <NUM> of the trapezoidal prism shaped portion <NUM>. The entry orifice <NUM> connects with the cavity <NUM>. Advantageously, a diameter of the entry orifice <NUM> is equal to the diameter d9 of the first portion <NUM> of the cavity <NUM>.

As shown in <FIG> an exit orifice <NUM> is arranged on the upper face <NUM> of the trapezoidal prism shaped portion <NUM>. The exit orifice <NUM> connects with the cavity <NUM>. Advantageously, a diameter of the exit orifice <NUM> is equal to the diameter d10 of the second portion <NUM> of the cavity <NUM>.

The cavity <NUM> is further shaped such that when the nut <NUM> surrounding the bar <NUM> contacts the lower face <NUM> of the centering guide <NUM>, the first end <NUM> of the bar <NUM> projects from the cavity <NUM> through the exit orifice <NUM>. Likewise, the cavity <NUM> is shaped such that when the handle <NUM> of the pushing rod <NUM> contacts the lower face <NUM> of the centering guide <NUM>, the first end <NUM> of the bar <NUM> projects from the cavity <NUM> through the exit orifice <NUM>. Thus, the cavity <NUM> extends along the axial direction E over a length L11 comprised between <NUM> and <NUM>, preferably between <NUM> and <NUM>. Advantageously, a length L12 of the first portion <NUM> of the cavity is comprised in a range from <NUM> to <NUM>, preferably from <NUM> to <NUM>.

A kit for replacing the JET filter <NUM> comprises at least one of the extractor <NUM>, the pushing rod <NUM> or the centering guide <NUM>.

Now, the method of extracting the JET filter from the fuel pump <NUM> by means of the extraction assembly of <FIG> is going to be described.

In particular, the method for extracting the JET filter <NUM> comprises a first step of positioning the centering guide <NUM> in the engine fuel pump <NUM>. The centering guide <NUM> is positioned in the fuel pump <NUM> by inserting the cylindrically shaped portion <NUM> inside the cavity <NUM> such that the rear face <NUM> of the trapezoidal prism shaped portion <NUM> contacts the face <NUM> of the fuel pump <NUM>, and the hole <NUM> of the centering guide <NUM> lies in front the hole <NUM> of the fuel pump <NUM>. Thus, the centering guide <NUM> can be screwed to the fuel pump <NUM>.

Secondly, the extractor <NUM> is inserted in the cavity <NUM> of the centering guide <NUM>. The bar <NUM> of the extractor <NUM> is in particular inserted in the cavity <NUM> through the entry orifice <NUM>. Then, a first force in a direction substantially parallel to the axial direction E of the cavity is applied on the extractor <NUM> such that the bar <NUM> slides along the cavity <NUM> until the first end <NUM> of the bar <NUM> contacts the JET filter <NUM>.

When the first end <NUM> of the bar <NUM> is in contact with the JET filter, a hole on the JET filter <NUM> must be made on the JET filter <NUM>. In order to make said hole on the JET filter <NUM>, the handle <NUM> of the extractor <NUM> is hit in the direction substantially parallel to the axial direction E of the cavity <NUM> until the nut <NUM> of the extractor <NUM> contacts the lower face <NUM> of the centering guide <NUM>.

Once the hole is done on the JET filter <NUM>, the first end <NUM> of the bar <NUM> is screwed to the JET filter <NUM>. In particular, the threaded surface of the first end <NUM> is screwed to the threaded surface of the JET filter <NUM>.

Finally, the extractor <NUM> screwed to the JET filter <NUM> is extracted from the cavity <NUM> of the centering guide <NUM>. Thus, the JET filter <NUM> is also extracted. The extraction is possible by applying a second force in a direction substantially parallel to the axial direction E of the cavity. In particular, the second force is applied in a substantially opposite direction than the first force. Since the diameter d10 of the second portion <NUM> of the cavity <NUM> is slightly larger than the diameter d3 of the bar <NUM>, the extraction of the extractor <NUM> from the cavity <NUM> may require the use of an adjustable wrench applied on the nut <NUM>.

Now, the method for fitting the JET filter <NUM> in the fuel pump <NUM> by means of the insertion assembly shown in <FIG>.

In order to fit the JET filter <NUM> in the fuel pump <NUM>, the centering <NUM> must be firstly positioned in the fuel pump <NUM>. As for the method for extracting the JET filter <NUM>, the positioning of the centering guide <NUM> in the fuel pump <NUM> is carried out by inserting the cylindrically shaped portion <NUM> inside the cavity <NUM> such that the rear face <NUM> of the trapezoidal prism shaped portion <NUM> contacts the face <NUM> of the fuel pump <NUM>, and such that the hole <NUM> of the centering guide <NUM> lies in front the hole <NUM> of the fuel pump <NUM>. Thus, the centering guide <NUM> can be screwed to the fuel pump <NUM>.

Secondly, the JET filter <NUM> slides inside the cavity <NUM> of the centering guide <NUM> by means of the pushing rod <NUM>. In particular, the sliding of the JET filter <NUM> inside the cavity <NUM> is carried out by pushing the JET filter <NUM> with the first end <NUM> of the bar <NUM> of the pushing rod <NUM>. The pushing rod <NUM> is pushed along the cavity by applying a first force in a direction substantially parallel to the axial direction E of the cavity <NUM>. Said first force is transmitted to the JET filter <NUM> because of the contact between the pushing rod <NUM> and the JET filter <NUM>, so that the JET filter <NUM> slides inside the cavity <NUM>.

The JET filter <NUM> and the pushing rod <NUM> are in particular inserted inside the cavity <NUM> through the entry orifice <NUM>. Before inserting the JET filter <NUM> in the cavity <NUM>, an end of the JET filter <NUM> is positioned on the hollow <NUM> of the pushing rod <NUM>. Then, the pushing rod <NUM> with the JET filter <NUM> placed on the hollow <NUM> are inserted in the cavity <NUM>. Alternatively, the JET filter <NUM> is inserted directly in the cavity <NUM> before inserting the pushing rod <NUM> in the cavity <NUM>.

Then, the JET filter <NUM> is installed in the fuel pump <NUM> by hitting the handle <NUM> of the pushing rod <NUM> in the direction substantially parallel to the axial direction E of the cavity <NUM> until the handle <NUM> of the pushing rod <NUM> contacts the lower face <NUM> of the centering guide <NUM>. In this configuration, the JET filter <NUM> is in a final position. In the final position the JET filter <NUM> is correctly installed in the fuel pump <NUM>.

Finally, the pushing rod <NUM> is extracted from the cavity <NUM> of the centering guide <NUM>. The extraction is possible by applying a second force in a direction substantially parallel to the axial direction E of the cavity <NUM>. In particular, the second force is applied in a substantially opposite direction in relation to the first force.

Please note that the invention is not limited to the illustrated embodiments. In particular, the method for extracting the JET filter <NUM> and the method for fitting the JET filter <NUM> can be carried out successively, so that the centering guide <NUM> is already positioned in the fuel pump <NUM> before the start of the method for fitting the JET filter <NUM> in the fuel pump. Thus, the first step of of positioning the centering guide <NUM> in the fuel pump <NUM> in the method for fitting the JET filter <NUM> can be omitted.

Additionally, the centering guide <NUM> is not limited to the described shape, other shapes of the centering guide <NUM> being possible.

Claim 1:
A kit for replacing a JET filter (<NUM>) arranged in an engine fuel pump (<NUM>), the JET filter (<NUM>) being placed on a lateral wall of a fuel pump cavity (<NUM>), the kit comprising an extractor (<NUM>) for extracting said JET filter (<NUM>), a pushing rod (<NUM>) for fitting a JET filter (<NUM>) in the engine fuel pump (<NUM>), and a centering guide (<NUM>) shaped to cooperate with the extractor (<NUM>) and with the pushing rod (<NUM>); wherein said centering guide (<NUM>) is configured to be partially positioned in the cavity (<NUM>) of the fuel pump (<NUM>), and
said centering guide (<NUM>) comprises a main body (<NUM>) including a cavity (<NUM>), wherein the cavity is shaped such that the JET filter (<NUM>) can be extracted from the engine fuel pump (<NUM>) by the extractor (<NUM>) or can be pushed to the engine fuel pump (<NUM>) by the pushing rod (<NUM>).