GB2589610A

GB2589610A - Method of removing lacquering from a fuel pump actuator

Info

Publication number: GB2589610A
Application number: GB1917733.6A
Authority: GB
Inventors: Faber Guillaume; Hoarau Yann
Original assignee: Delphi Technologies IP Ltd
Current assignee: Delphi Technologies IP Ltd
Priority date: 2019-12-04
Filing date: 2019-12-04
Publication date: 2021-06-09
Also published as: GB201917733D0

Abstract

Method (100, fig.6) of removing lacquering in a fuel pump actuator 10 comprising a solenoid, a valve member, and an actuator stem, the method comprising the steps of: a) fixing the fuel pump actuator 10 to a connection device 32; b) injecting in the actuator a lacquering solvent; c) evacuating air from the actuator; and d) extracting from the actuator a mixture of the lacquering solvent and dissolved lacquering. Wherein the injecting of the solvent at step b) is via an inlet syringe 34, and extraction of the air at step c), and the lacquering solvent and dissolved lacquering at step d), is via an outlet syringe 36. Both syringes are connected to the connection device 32. An electronic device 40 can also be used to energise the solenoid to displace the valve member.

Description

METHOD OF REMOVING LACQUERING FROM A FUEL PUMP

ACTUATOR

TECHNICAL FIELD

The present invention relates to a method of removing lacquering in a fuel pump actuator allowing extending the lifespan of the fuel pump actuator.

BACKGROUND OF THE INVENTION

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 going through the fuel pump actuator is subjected to high pressures and high temperatures, provoking the formation of lacquering deposits that are accumulated on the actuator's walls. The accumulation of lacquering on the actuator's wall disturbs the movement of the different parts included inside the actuator, slowing down the fuel flowing.

Classically, when lacquering problems are found in the fuel pump actuator, the fuel pump actuator must be replaced by a new one. Nevertheless, this solution is costly and reduces the lifespan of the fuel pump actuator.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to resolve the above-25 mentioned problem in providing a method of removing lacquering in a fuel pump actuator provided with at least a solenoid, a valve member and an actuator stem, the method comprising the steps of: a) fixing the fuel pump actuator to a connection device; b) injecting in the fuel pump actuator a lacquering solvent; c) evacuating air from the fuel pump actuator; and d) extracting from the fuel pump actuator a mixture of the lacquering solvent and dissolved lacquering Thanks to the claimed method, the lacquering on the fuel pump actuator is dissolved by the action of the lacquering solvent and removed from the fuel pump actuator by the extraction of the mixture of the lacquering solvent and dissolved lacquering. Hence, the fuel pump actuator is free from lacquering, avoiding the need of replacing it.

Step c) may be performed by means of an outlet syringe adapted to be connected to the connection device Step b) may be performed by means of an inlet syringe connected to the connection device, the inlet syringe containing the lacquering solvent.

Step b) may be performed by applying to the lacquering solvent in the inlet syringe a pressure comprised in a range from 1 bar to 7 bar, preferably from 2 bar to 6 bar.

Step c) may be carried out by means of an electronic device adapted to energise the solenoid of the fuel pump actuator, the energisation of the solenoid provoking a displacement of the valve member.

The electronic device adapted to energise the solenoid during step c) may be connected to the solenoid by means of an electrical connector cable adapted to establish a connection between the electronic device and the solenoid of the fuel pump actuator.

Step d) may be carried out after a time comprised in a range between 20 min and 70 min after the evacuation of air of step c), preferably between 30 min and 60 min Step d) may be performed by means of the outlet syringe.

An additional step of injecting in the fuel pump actuator the lacquering solvent may be carried out between step c) and step d).

BRIEF DESCRIPTION OF THE DRAWINGS

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

Figure 1 shows a schematic view of a longitudinal section of a fuel pump actuator Figure 2 shows a schematic frontal view of a connection device receiving an inlet syringe and an outlet syringe as per a step of a method of removing lacquering according to the present invention.

Figure 3 shows a schematic view of an assembly of the connection device of figure 2 connected to the fuel pump actuator of figure 1 as per another step of the method according to the present invention Figure 4 shows a schematic longitudinal section of the assembly of figure Figure 5 shows a longitudinal section of the assembly of figure 3 as per another embodiment of the present invention Figure 6 shows a flowchart of the method of removing lacquering in a fuel pump actuator of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in figure 1, a fuel pump actuator 10 comprises a valve member 12, an actuator stem 14, and a solenoid 16. The valve member 12 is movable inside a valve housing 18. In particular, the valve member 12 can be displaced inside the valve housing 18 along an axial direction A of the actuator 10.

Preferably, the valve housing 18 and the valve member 12 have a substantially cylindrical shape.

The actuator stem 14 is coupled to an armature 20, the armature 20 being displaceable along the axial direction A by virtue of a magnetic field created by the solenoid 16. A displacement of the armature 20 provokes an analog displacement of the actuator stem 14 along the axial direction A. A first end of the actuator stem 14 cooperates with a first end of the valve member 12, such that the displacement of the actuator stem 14 along the axial direction A causes an equivalent displacement of the valve member 12 along the axial direction A. The cooperation of the actuator stem 14 and the valve member 12 is assured by a first spring 22 and a second spring 24. The first spring 22 is placed at a second end of the actuator stem 14 and the second spring 24 is placed at a second end of the valve member 12. The first spring 22 biases the actuator stem 14 against the valve member 12, while the second spring 24 biases the valve member 12 against the actuator stem 14. Thus, the valve member 12 and the actuator stem 14 remain coupled together despite the displacement of the actuator stem 14 or the displacement of the valve member 12.

The actuator 10 further comprises an inlet passage 26 disposed laterally to the valve housing 18. The inlet passage 26 is supplied with fuel from a fuel pump.

An orifice 28 extends radially inside the valve housing 18 In an initial position, the orifice 28 lies in front of the inlet passage 26, allowing the passage of fuel inside the actuator.

The actuator 10 is configured to control an extent of the orifice 28 in front of the inlet passage 26, such that the quantity of fuel flowing from the fuel pump to fuel injectors is regulated. In particular, when the solenoid 16 generates the magnetic field, the armature 20 is displaced along the axial direction A towards the second spring 24, the stem actuator 14 being displaced in the same way. Because of the cooperation between the actuator stem 14 and the valve member 12, the valve member 12 is also displaced towards the spring 22.

Due to the displacement of the valve member 12, an extent of the orifice 28 in front of the inlet passage 26 is reduced, the quantity of fuel entering the actuator 10 being limited. It is also possible that the displacement of the valve member 12 obstructs integrally the orifice 28, the entering of fuel inside the actuator 10 being avoided.

An outlet passage 30 is disposed at an end of the actuator 10.

Advantageously, the outlet passage 30 allows the exit of fuel from the actuator to an inlet check valve (not shown).

Fuel going through the actuator 10 is subjected to a high pressure and a high temperature, provoking the formation of lacquering particles inside the actuator 10 due to an incomplete combustion of fuel.

Generally, lacquering particles are composed of a carbon core representing 50% to 75% by weight of each lacquering particle. Lacquering particles further comprise water, sulphur compounds, for example SF), and other mineral matter.

Lacquering particles aggregate to form a lacquering layer that accumulates on internal surfaces of the actuator 10. The lacquering layer disturbs the proper functioning of the actuator 10. In particular, the layer of lacquering hinders the displacement of the valve member 12, the actuator stem 14 or the armature 20 along the axial direction A. Thus, the efficiency of the actuator 10 is reduced.

It is now disclosed a method 100 of removing lacquering from the fuel pump actuator 10.

Obviously, the invention is not limited to the previously described actuator 10 but, on the contrary, the method 100 applies to different types of actuator 10 In order to apply the method 100, the actuator 10 is taken out from the fuel pump.

A first step SI of the method 100 involves fixing the actuator 10 to a connection device 32.

As shown in figures 2 and 3, the connection device 32 is a substantially prismatic piece, and preferably a substantially parallelepiped-shaped piece. The connection device 32 has at least three connection holes, each connection hole being disposed in a different face of the prismatic connection device 32.

A first connection hole 321 is adapted to receive the actuator 10, the actuator 10 being fixed to the first connection hole 321 by the valve housing 18. In particular, when the actuator 10 is fixed to the connection device 32, the inlet passage 26 and the outlet passage 30 are placed inside the connection device 32.

A second and a third connection holes 322, 323 are adapted to receive, respectively, an inlet syringe 34 and an outlet syringe 36. The inlet and outlet syringe 34, 36 comprise a plunger displaceable inside a body adapted to contain a liquid. Advantageously, the bodies of the inlet and outlet syringes 34, 36 comprise a front hole 341, 361 allowing the exit of liquid from the inlet syringe 34 and the entry of liquid inside the outlet syringe 36.

In particular, the front holes 341, 361 in the inlet syringe 34 and in the outlet syringe 36 allow establishing an airtight fixation between the syringes 34, 36 and the connection device 32.

The airtight fixation between the syringes 34, 36 and the connection device 32 is established by means of an airtight adaptor 38 disposed between the inlet syringe 34 and the second connection hole 322, and another airtight adaptor 38 disposed between the outlet syringe 36 and the third connection hole 323. The syringes 34, 36 establish in particular a screw connection with the airtight adaptors 38.

Advantageously, the actuator 10 is also hermetically fixed to the first connection hole of the connection device 32.

Once the actuator 10 is fixed to the connection device 32, the outlet passage 30 is placed in front of the second connection hole 322 adapted to receive the inlet syringe 34, while the inlet passage 26 is placed in front of the third connection hole 323 adapted to receive the outlet syringe 36. Thus, the front hole 34i of the inlet syringe 34 communicates with the outlet passage 30 of the actuator 10, and the front hole 363 of the outlet syringe 36 communicates with the inlet passage 26 of the actuator 10, the communication between the syringes 34, 36 and the passages 26, 30 being established by means of the airtight adaptors 38.

Before being fixed to the connection device 32, the inlet syringe 34 is filled with a lacquering solvent. The lacquering solvent is in particular a solution containing 50% of water and 50% of a cleaning agent. The cleaning agent is well-known to a person skilled in the art under the name of Decon 90.

A second step S2 involves injecting the lacquering solvent inside the actuator 10.

The injection of the lacquering solvent is performed by pushing, by means of the inlet syringe 34, the lacquering solvent inside the actuator 10 through the outlet passage 30. The injection of the lacquering solvent is carried out at a pressure high enough to allow the lacquering solvent to go through the different elements of the actuator 10. The pressure is in particular comprised in a range from 1 bar to 7 bar, preferably from 2 bar to 6 bar.

A third step S3 involves evacuating air from the actuator 10 by means of the outlet syringe 36. The air is in particular an air caught in the actuator 10 because of the hermetical fixation of the actuator 10, the inlet syringe 34 and the outlet syringe 36 to the connection device 32.

In order to extract air from the actuator 10, the lacquering solvent injected into the actuator is extracted by means of the outlet syringe 36. When air remains inside the actuator 10 or the connection device 32, bubbles can be seen inside the outlet syringe 36. During this operation, the outlet syringe 36 may be rinsed several times until the extracted lacquering solvent does not contain any bubble, implying that the actuator 10 is free from air.

In order to carry out step S3, the solenoid 16 is energised by means of an electronic device 40 connected to the solenoid 16 of the actuator 10 by means of an electrical connector cable 42.

The electrical connector cable 42 may have a cable head adapted to a specific type of actuator 10. Alternatively, the cable head 44 of the electrical connector cable 42 may be exchanged in order to adapt the electrical connector cable 42 to a full range of actuators 10.

The electronic device 40 is in particular a command unit generating an electrical current when activated.

The electrical current generated by the electronic device 40 is transmitted to the solenoid 16, creating the magnetic field that provokes the displacement of the armature 20 along the axial direction A towards the spring 24. Thus, the valve member 18 is also displaced along the axial direction A towards the spring 24.

Advantageously, the solenoid 16 is repeatedly energised, provoking a continuous back and forth movement of the valve member 18. A maximal evacuation of the air caught in the actuator 10 is possible thanks to the back and forth movement of the valve member 18.

Once the actuator 10 is free from air, lacquering solvent is able to cover every internal surface of the actuator 10 due to the absence of air inside the actuator 10. If the quantity of lacquering solvent remaining in the actuator 10 is not enough to cover every internal surface of the actuator 10, lacquering solvent is injected again in the actuator 10 by means of the inlet syringe 34.

The lacquering solvent injected in the actuator 10 is maintained therein during a time, called action time, comprised in a range between 20 min to 70 mm, preferably between 30 min and 60 min. During the action time, the lacquering solvent reacts with the lacquering layer accumulated on the internal surfaces, provoking the dissolution of the lacquering layer on the lacquering solvent. A mixture of the lacquering solvent and dissolved lacquering appears inside the actuator 10.

Once the action time has passed, a forth step S4 can be performed. Step S4 involves extracting from the fuel pump actuator 10 the mixture of lacquering solvent and dissolved lacquering by means of the outlet syringe 36. The mixture of lacquering solvent and dissolved lacquering goes out from the actuator 10 through the inlet passage 26 in communication with the front hole of the outlet syringe 36.

Advantageously, a colour of the lacquering solvent differs from a colour of the mixture of lacquering solvent and dissolved lacquering. Thus, a maximal level of lacquering removal is attained when the mixture extracted by the outlet syringe 36 has substantially the same colour of the lacquering solvent. In this situation, the outlet syringe 36 is actually extracting the lacquering solvent instead of the mixture, since lacquering inside the actuator 10 has already been totally, or almost totally, removed. It is possible that the step S2 of injecting the lacquering fuel solvent inside the actuator 10 should be carried out several times in order to attain the maximal level of lacquering removal.

Thanks to the described method 100, the lacquering layer formed on the internal surfaces of the actuator 10 is removed, so that the displacement of the valve member 12, the actuator stem 14 or the armature 20 along the axial direction A of the actuator 10 is not anymore disturbed. Therefore, the actuator 10 does not need to be replaced by a new one, its lifespan being increased.

Please note that the invention is not limited to the illustrated embodiments. In particular, the method 100 of removing lacquering is not limited to the fuel pump actuator 10 as disclosed. On the contrary, it can be applied to other types of fuel pump actuators. For example, as shown in figure 5, the connection device can be connected to a diameter adaptor 46 in order to be adapted to different sizes of actuators 10.

Additionally, the described arrangement of the syringes 34, 36 in the connection device 32 may change. For example, the inlet syringe 34 could be in communication with the inlet passage 26 of the actuator 10, while the outlet syringe 36 could be in communication with the outlet passage 30 of the actuator 10.

Moreover, syringes 34, 36 can be replaced by any other means adapted to, respectively, inject/extract the lacquering solvent in/from the fuel pump actuator 10.

LIST OF REFERENCES

A axial direction of the actuator Si first step S2 second step S3 third step S4 forth step fuel pump actuator 12 valve member 1 0 14 actuator stem 16 solenoid 18 valve housing armature 22 first spring 24 second spring 26 inlet passage 28 orifice outlet passage 32 connection device 321 first connection hole 322 second connection hole 323 third connection hole 34 inlet syringe 341 front hole of the inlet syringe 36 outlet syringe 361 front hole of the outlet syringe 38 airtight adaptor electronic device 42 electrical connector cable 44 cable head of the electrical connector cable 46 diameter adaptor method of removing lacquering

Claims

CLAIMS: A method (100) of removing lacquering in a fuel pump actuator (10) provided with at least a solenoid (16), a valve member (12) and an actuator stem (14), the method (100) comprising the steps of a) fixing the fuel pump actuator (10) to a connection device (32); b) injecting in the fuel pump actuator (10) a lacquering solvent; c) evacuating air from the fuel pump actuator (10); and d) extracting from the fuel pump actuator (10) a mixture of the lacquering solvent and dissolved lacquering.
2 A method (100) as per claim 1, wherein step c) is performed by means of an outlet syringe (36) adapted to be connected to the connection device (32).
3. A method (100) as per claims 1 or 2, wherein step b) is performed by means of an inlet syringe (34) connected to the connection device (32), the inlet syringe (34) containing the lacquering solvent.
4. A method (100) as per claim 3, wherein step b) is performed by applying to the lacquering solvent in the inlet syringe (34) a pressure comprised in a range from 1 bar to 7 bar, preferably from 2 bar to 6 bar.
5. A method (100) as per anyone of the preceding claims, wherein step c) is carried out by means of an electronic device (40) adapted to energise the solenoid of the fuel pump actuator (10), the energisation of the solenoid provoking a displacement of the valve member (12).
6. A method (100) as per claim 5, wherein the electronic device (40) adapted to energise the solenoid (16) during step c) is connected to the solenoid (16) by means of an electrical connector cable (42) adapted to establish a connection between the electronic device (40) and the solenoid (16) of the fuel pump actuator (10).
7. A method (100) as per anyone of the preceding claims, wherein step d) is carried out after a time comprised in a range between 20 min and 70 min after the evacuation of air of step c), preferably between 30 min and 60 min
8. A method (100) as per anyone of claims 2 to 7, wherein step d) is performed by means of the outlet syringe (36).
9. A method (100) as per anyone of the preceding claims, wherein an additional step of injecting in the fuel pump actuator (10) the lacquering solvent is carried out between step c) and step d).