Overmolded coil assembly for fuel pump

Abstract

An overmolded coil assembly (60) is provided, comprising a body (62) having a hollow cylindrical shape and including an inner surface (62b) defining a central opening (62d) and a recess (62c). A spool (64) is received in the recess of the body. The spool comprises an annular barrel (64e) and has opposing first and second ends (64a, 64b). The first end (64a) is adjacent to the central opening of the body. A coil (66) of electrically conductive wire is arranged within the annular barrel of the spool and surrounds it. A washer (68) having inner and outer surfaces (68c, 68d) is adjacent to the second end of the spool. An overmolded element (72) made of an electrically insulating material covers the spool, coil, washer and body, and seals the periphery of the spool, coil, washer and body. A fuel pump (20) including the overmolded coil assembly and a method for sealing the coil assembly are also provided.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims the benefit of U.S. Patent Application No. 18 / 197,181, filed May 15, 2023, the disclosure of which is incorporated herein by reference in its entirety.

[0002] The present disclosure generally relates to fuel pumps for supplying fuel to internal combustion engines, and more particularly to coil assemblies for operating valves of fuel pumps.

Background Art

[0003] Modern fuel systems for internal combustion engines that use gasoline as fuel, particularly those used in the automotive industry, employ gasoline direct injection (GDi), where the fuel injection device injects fuel directly into the combustion chamber of the internal combustion engine. In a system employing GDi, fuel from the fuel tank is typically supplied at a relatively low pressure by a low - pressure fuel pump, which is an electric fuel pump installed within the fuel tank. The low - pressure fuel pump supplies fuel to a high - pressure fuel pump, which generally includes a fuel pump housing and a pumping plunger that reciprocates within the fuel pump housing by means of the camshaft of the internal combustion engine. The reciprocating motion of the pumping plunger further pressurizes the fuel and supplies it to a fuel injection device that injects the fuel directly into the combustion chamber of the internal combustion engine. During operation, the internal combustion engine is subject to varying demands for output torque. To meet the varying demands for output torque, it is necessary to vary the amount of fuel supplied with each stroke of the pumping plunger. One strategy for varying the fuel supply by the high - pressure fuel pump is to use an intake valve assembly that includes a solenoid. The intake valve assembly (i.e., spill valve) can completely fill the pump chamber with fuel during each intake stroke, but the solenoid can be operated to keep the intake valve assembly open during part of the compression stroke of the pumping plunger, allowing some of the fuel to return to the original supply source. Then, when the solenoid is operated to close the intake valve assembly, the remaining part of the compression stroke pressurizes the fuel and discharges the fuel to the fuel injection device.

[0004] To prevent fuel leakage, sealing devices are provided to seal the space between the fuel pump housing and the intake valve assembly. In devices such as those described in U.S. Patent No. 10,947,942 by Stritzel et al., a portion of the intake valve assembly is welded to the fuel pump housing to provide a sealed interface. In other devices, such as those described in U.S. Patent No. 7,401,594 by Usui et al., the intake valve assembly can be sealed to the fuel pump housing by providing radially arranged O-rings between the intake valve assembly and the fuel pump housing. In either case, the sealing device is provided to prevent fuel from leaking out of the fuel pump housing from between the intake valve assembly and the fuel pump housing. Despite these measures, the portion of the intake valve assembly extending outside the fuel pump housing is exposed to environmental conditions, and liquids such as rainwater and saltwater from roads containing de-icing agents may adhere to the intake valve assembly. These fluids can penetrate the interfaces of the components forming the intake valve assembly or solenoid, potentially damaging some or all of the components of the intake valve assembly or solenoid over time, which could lead to improper operation of the intake valve assembly or fuel leakage.

[0005] In particular, in some devices, the intake valve assembly includes a solenoid having a body portion (inner housing) on ​​the fuel pump housing, and a coil assembly attached to the body portion. The coil assembly contains a coil and is electrically connected to a power source, thereby supplying electricity to the coil which acts on the magnetic pole pieces of the body portion. A narrow clearance space exists between the coil assembly and the body portion. However, existing solenoid designs include multiple leak paths in the coil assembly, allowing water and contaminants to enter the narrow clearance space. This narrow clearance space between the coil assembly and the body portion is susceptible to crevice corrosion when exposed to water and other contaminants that may enter through the leak paths. This crevice corrosion can create corrosion pits on the outer surface of the body portion, which over time can puncture the body and cause fuel leaks.

[0006] Therefore, there is a need for a fuel pump with an intake valve assembly in which the coil assembly minimizes or eliminates some or all of the above-mentioned drawbacks. [Overview of the project]

[0007] An improved coil assembly for a fuel pump is provided. The coil assembly is an overmolded coil assembly that reduces or eliminates leakage paths present in conventional designs. The overmolded coil assembly includes a body. The body generally has a hollow cylindrical shape and an inner surface that defines a central opening and a recess. A spool is received in the recess of the body. The spool includes an annular barrel and has opposing first and second ends. The first end is adjacent to the central opening of the body, and the inner surface of the annular barrel defines an axial hole. A coil of electrically conductive wire is placed within the annular barrel of the spool and surrounds it. A washer with an inner and outer surface is adjacent to the second end of the spool. The inner surface of the washer defines an axial hole. An overmolded element made of an electrically insulating material covers the spool, coil, washer, and body and seals the periphery of the spool, coil, washer, and body.

[0008] In certain embodiments, the overmolded element, the axial hole in the spool, the axial hole in the washer, and the central opening in the body together define the plug.

[0009] In certain embodiments, the plug is sealed by an overmolded element.

[0010] In certain embodiments, the plug is open only at the central opening of the body.

[0011] In certain embodiments, the body has an outer surface, and the overmolded element covers the outer surface of the body at least partially.

[0012] In certain embodiments, the body includes at least one annular groove at the end of the overmolded element.

[0013] In certain embodiments, the overmolded element forms an annular slot into which a portion of the main body is received.

[0014] In certain embodiments, the bush is adjacent to the washer on the opposite side of the spool.

[0015] In certain embodiments, the bush has an inner annular surface defining an axial hole, and the axial hole of the bush, the overmolded element, the axial hole of the spool, the axial hole of the washer, and the central opening of the body together define the plug.

[0016] In certain embodiments, the outer surface of the washer includes at least one notch that defines a passage through which the overmolded element extends.

[0017] In certain embodiments, the overmolded element extends from the plug and defines the electrical connector.

[0018] Fuel pumps including an overmolded coil assembly are also provided. In some embodiments, the fuel pump has a fuel pump housing in which a pump chamber is defined, and an intake valve bore extending outside the fuel pump housing along the intake valve bore axis. A pumping plunger reciprocates within the plunger bore, with the intake stroke of the pumping plunger increasing the volume of the pump chamber, and the compression stroke of the pumping plunger decreasing the volume of the pump chamber. A solenoid assembly selectively provides (1) fluid communication between the intake port of the fuel pump and the pump chamber, and (2) selectively prevents fluid communication between the intake port of the fuel pump and the pump chamber. The solenoid assembly includes an inner housing housed within the intake valve bore, the inner housing extending outside the fuel pump housing. A magnetic pole piece made of a magnetically permeable material is located within the inner housing. The overmolded coil assembly is combined with the inner housing, and the coil surrounds the pole piece from the outside. When electricity is supplied to the coil, it creates a magnetic attraction between the pole piece and the valve element of the solenoid assembly, causing the valve element to move toward the pole piece.

[0019] In certain embodiments, the overmolded element, the axial hole in the spool, the axial hole in the washer, and the central opening in the body together define the plug.

[0020] In certain embodiments, the plug is sealed by an overmolded element.

[0021] In certain embodiments, the plug is open only at the central opening of the body.

[0022] In certain embodiments, the plug is combined with an inner housing.

[0023] In certain embodiments, the bush is adjacent to the washer on the opposite side of the spool, the bush has an inner annular surface, and the inner annular surface of the bush, the overmolded element, the axial hole of the spool, the axial hole of the washer, and the central opening of the body together define the plug.

[0024] In certain embodiments, the body has an outer surface, and the overmolded element covers the outer surface of the body at least partially.

[0025] A method of sealing a coil assembly of a fuel pump is also provided. The method includes providing a spool that includes an annular barrel and has opposing first and second ends, wherein an inner surface of the annular barrel defines an axial hole. The method further includes disposing a coil of an electrically conductive wire within and surrounding the annular barrel of the spool. The method further includes disposing a washer adjacent to the second end of the spool, the washer having an inner surface and an outer surface, wherein the inner surface of the washer defines an axial hole. The method further includes disposing a bushing adjacent to the washer on a side opposite the spool, the bushing having an inner annular surface that defines an axial hole. The method further includes forming an overmold element made of an electrically insulating material over the spool, the coil, the washer, and the bushing, the overmold element covering the spool, the coil, the washer, and the bushing. The method further includes providing a body having a hollow cylindrical shape and including an inner surface that defines a central opening, an outer surface, and a recess. The method further includes press-fitting the overmold element into the body, wherein the spool, the coil, and the washer are received within the recess of the body, and the overmold element covers at least a portion of the outer surface of the body, whereby the overmold element seals around the spool, the coil, the washer, the bushing, and the body, and the overmold element, the axial hole of the spool, the axial hole of the washer, and the central opening of the body together define a plug sealed by the overmold element.

Brief Description of the Drawings

[0026] Various advantages and aspects of the present disclosure will be understood by considering the following detailed description in connection with the accompanying drawings.

[0027] [Figure 1] FIG. 1 is a schematic view of a fuel system including a fuel pump having an overmolded coil assembly according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view of the fuel pump of FIG. 1. [Figure 3]Figure 3 is an enlarged view of a part of Figure 2 showing an intake valve assembly of a fuel pump including an overmolded coil assembly. [Figure 4] Figure 4 is a perspective view of the overmolded coil assembly. [Figure 5] Figure 5 is a side view of the overmolded coil assembly. [Figure 6] Figure 6 is a cross-sectional view of the overmolded coil assembly taken along line 6-6 of Figure 5. [Figure 7] Figure 7 is a cross-sectional view of the overmolded coil assembly taken along line 7-7 of Figure 6.

Mode for Carrying Out the Invention

[0028] Referring to FIGS. 1-7, the same numbers indicate corresponding parts throughout several drawings, and an overmolded coil assembly for a fuel pump is illustrated and shown as overmolded coil assembly 60. In an exemplary embodiment, the overmolded coil assembly 60 is applied to a fuel pump 20 of a gasoline direct injection (GDi) device. Although the fuel pump is shown as a GDi pump, it should be understood that the present invention is not limited to the use of a GDi pump and can also be applied to other fuel / fluid pumps. The overmolded coil assembly 60 closes, blocks, and seals leakage paths existing in conventional coil assemblies.

[0029] In exemplary embodiments of this disclosure, referring first to Figure 1, a fuel system 10 for an internal combustion engine 12 is schematically shown. The fuel system 10 generally includes a fuel tank 14 that holds fuel supplied for the operation of the internal combustion engine 12, a plurality of fuel injectors 16 that directly inject fuel into each combustion chamber (not shown) of the internal combustion engine 12, a low-pressure fuel pump 18, and a high-pressure fuel pump 20, the low-pressure fuel pump 18 drawing fuel from the fuel tank 14, increasing the pressure of the fuel and supplying it to the high-pressure fuel pump 20, the high-pressure fuel pump 20 further increasing the pressure of the fuel and supplying it to the fuel injectors 16. In a non-limiting example, the low-pressure fuel pump 18 can increase the fuel pressure to about 500 kPa or less, and the high-pressure fuel pump 20 can increase the fuel pressure to about 14 MPa or more, and possibly 35 MPa or more. Although four fuel injectors 16 are shown, it should be understood that fewer or more fuel injectors 16 may be provided depending on the number of cylinders / combustion chambers included in the internal combustion engine.

[0030] As shown, the low-pressure fuel pump 18 may be located inside the fuel tank 14. However, instead, the low-pressure fuel pump 18 may be located outside the fuel tank 14. The low-pressure fuel pump 18 may be an electric fuel pump well known to those skilled in the art. The low-pressure fuel supply passage 22 provides fluid communication from the low-pressure fuel pump 18 to the high-pressure fuel pump 20. A fuel pressure regulator 24 may be provided, which returns some of the fuel supplied by the low-pressure fuel pump 18 to the fuel tank 14 through the fuel return passage 26 in order to maintain a nearly uniform pressure in the low-pressure fuel supply passage 22. Although the fuel pressure regulator 24 is shown in the low-pressure fuel supply passage 22 outside the fuel tank 14, it should be understood that the fuel pressure regulator 24 may be located inside the fuel tank 14 and integrated with the low-pressure fuel pump 18.

[0031] Referring further to Figure 2, the high-pressure fuel pump 20 has a fuel pump housing 28 which includes a plunger hole 30 extending along and centered on the plunger hole axis 32. As shown, the plunger hole 30 may be defined directly by the insert and the fuel pump housing 28. The high-pressure fuel pump 20 also includes a pumping plunger 34 located within the plunger hole 30 and reciprocating within the plunger hole 30 along the plunger hole axis 32 based on input from the rotating camshaft 36 of the internal combustion engine 12 (shown only in Figure 1). The pump chamber 38 is defined within the fuel pump housing 28, more specifically, the pump chamber 38 is defined by the plunger hole 30 and the pumping plunger 34. The intake valve assembly 40 of the high-pressure fuel pump 20 is received within the intake valve hole 28a of the fuel pump housing 28, the intake valve hole 28a extending outside the fuel pump housing 28 and along the intake valve hole axis 28b. The high-pressure fuel pump 20 selectively provides and prevents fluid communication between the intake port 20a of the high-pressure fuel pump 20 and the pump chamber 38 via the pump housing intake passage 41 of the fuel pump housing 28. On the other hand, the exhaust valve assembly 42 is located in the exhaust passage 43 of the fuel pump housing 28 and selectively allows the flow of fuel from the pump chamber 38 to the fuel injectors 16 via the fuel rail 44, through which each fuel injector 16 is in fluid communication. During operation, the reciprocating motion of the pumping plunger 34 causes the plunger return spring 46 to move the pumping plunger 34 downward to increase the volume of the pump chamber 38 during the intake stroke (downward in Figure 2). Conversely, during the compression stroke (upward in Figure 2), the camshaft 36 moves the pumping plunger 34 upward against the force of the plunger return spring 46 to decrease the volume of the pump chamber 38. In this way, fuel is selectively drawn into the pump chamber 38 during the intake stroke in accordance with the operation of the intake valve assembly 40, and conversely, during the compression stroke, the fuel is pressurized in the pump chamber 38 by the pumping plunger 34 and discharged under pressure to the fuel rail 44 and fuel injector 16 through the exhaust valve assembly 42.

[0032] Referring particularly to Figure 3, the intake valve assembly 40 includes a valve body 48, a valve element 50 located within the valve body 48, and a solenoid assembly 52. ​​The valve body 48 is cylindrical and extends along the intake valve bore axis 28b. The valve body 48 is in fluid communication with the pump housing intake passage 41 via a valve body intake passage 49. The valve body 48 also includes a number of valve body exhaust passages 54 provided in the end walls of the valve body, and the valve body 48 is in fluid communication with the pump chamber 38. The valve element 50 is made of a magnetic material and also extends along the intake valve bore axis 28b. The valve element 50 slides within the valve body 48 to open and close the valve body intake passage 49.

[0033] The solenoid assembly 52 includes an inner housing 56, a magnetic pole piece 57 located within the inner housing 56, and a return spring 58. The inner housing 56 extends along its axis, with the intake valve bore axis 28b as the center. The inner housing 56 is received within the valve body 48 and is sealed to the valve body 48 and therefore to the fuel pump housing 28, preventing fuel leakage from the pump housing intake passage 41 to the outside of the fuel pump housing 28. This sealing may be achieved by, in some, non-limiting examples, an interference fit between the inner housing 56 and the valve body 48, welding around the inner corners where the inner housing 56 contacts the valve body 48, and one or more adhesives.

[0034] The pole piece 57 is made of a magnetically permeable material and is received within the inner housing 56, extending along the axis of the intake valve bore axis 28b. The pole piece bore 57a penetrates the pole piece 57 axially and includes a shoulder 57b. A return spring 58 is partially received in the pole piece bore 57a and strikes the pole piece shoulder 57b. The return spring 58 is compressed and held between the pole piece shoulder 57b and the valve element 50, in this way the return spring 58 biases the valve element 50 away from the pole piece 57.

[0035] Referring further to Figures 4-7, the solenoid assembly 52 further includes a subassembly, in particular, an overmolded coil assembly 60. The coil assembly 60 includes a body 62 having a hollow cylindrical shape. The body 62 has an outer surface 62a defining a recess 62c, an inner surface 62b on the opposite side, and a central opening 62d at one end 62e of the body 62, the central opening 62d opening into and continuous with the recess 62c. The body 62 further includes an inwardly extending flange 62f that is continuous with the inner surface 62b and defines a shoulder 62g. The flange 62f extends to the central opening 62d and is at a distance from the end 62e of the body. The outer diameter of the body 62 is slightly narrowed at the flange 62f, and the portion of the body 62 between the flange 62f and the end 62e of the body forms an end annular ring 62h having a diameter smaller than the diameter of the rest of the body 62. The body 62 may be made of a metal such as stainless steel.

[0036] The spool 64 is received in a recess 62c of the body 62. The spool 64 has a first end 64a and a second end 64b opposite to it, and flanges 64c, 64d at the first end 64a and the second end 64b, respectively, and an annular barrel 64e between the flanges 64c, 64d. The inner surface 64f of the annular barrel 64e defines an axial hole 64g, and the spool 64 has a cylindrical shape. The first end 64a of the spool 64 rests on the shoulder 62g of the body 62 and is adjacent to the central opening 62d of the body 62, so that the axial hole 64g of the spool 64 is continuous with and substantially continuous with the central opening 62d. A coil 66 of conductive wire (e.g., copper wire) is placed on and wound around the annular barrel 64e, so that the coil 66 surrounds the annular barrel 64e. The spool 64 may be formed of an electrically insulating material such as plastic, for example, PA66, i.e., nylon (polyamide) 66.

[0037] The washer 68 is positioned adjacent to the second end 64b of the spool 64 and in a recess 62c of the body 62. In this way, the spool 64 is axially positioned between the washer 68 and the flange 62f of the body 62. The washer 68 has a first side 68a, a second side 68b on the opposite side, an inner surface 68c, and an outer surface 68d. The first side 68a of the washer 68 is in contact with the second end 64b of the spool 64. The inner surface 68c of the washer 68 defines an axial hole 68e, and the washer 68 has a disc shape. The axial hole 68e of the washer 68 is continuous with and substantially continuous with the axial hole 64g of the spool 64. The outer surface 68d of the washer 68 includes at least one notch 68f, each defining a passage 68g for a purpose described later. For example, a washer 68 may include three rectangular or trapezoidal wedge-shaped notches 68f removed from its outer surface 68d. The washer 68 also provides a path for magnetic flux to pass through when current flows through the coil 66, and for this reason, the washer 68 may be called a flux washer. The washer may be made of a metal such as stainless steel.

[0038] The bush 70 is adjacent to the second side portion 68b of the washer 68 on the opposite side of the spool 64. In this way, the washer 68 is axially positioned between the spool 64 and the bush 70. The bush 70 extends outward from the recess 62c of the body 62, is cylindrical in shape, and has a first end 70a in contact with the washer 68, a second end 70b on the opposite side, an annular outer surface 70c, and an annular inner surface 70d on the opposite side. The inner surface 70d of the bush 70 is continuous with the axial hole 68e of the washer 68, forming a substantially continuous axial hole 70e. The bush 70 may be formed of, for example, powder metal.

[0039] An overmolded element 72 made of an electrically insulating material covers the bush 70, spool 64, coil 66, washer 68, and body 62, sealing around the bush 70, spool 64, coil 66, washer 68, and body 62. The electrically insulating material may be a plastic such as PA66, i.e., nylon (polyamide)66, but is not limited to PA66. The bush 70, washer 68, spool 64, and coil 66 are enclosed within the overmolded element 72. The overmolded element 72 covers at least partially the outer surface 62a of the body 62, for example, from the end 62i of the recess 62c to the vicinity of the flange 62f. The overmolded element 72 forms an annular slot 72a that receives a portion of the body 62, in particular the side wall 62j that forms the recess 62c. The outer surface 62a of the main body 62 may have one or more annular grooves 62k near the end 72b of the overmolded element 72 and the flange 62f of the main body 62. The annular grooves 62k provide an interference fit between the overmolded element 72 and the main body 62. When forming the overmolded element 72, the passage 68g of the washer 68 allows the overmolded element material (e.g., plastic) to flow through the washer into the space between the spool 64 / coil 66 and the inner surface 62b of the main body 62.

[0040] The overmolded element 72, the axial hole 70e of the bush 70, the axial hole 64g of the spool 64, the axial hole 68e of the washer 68, and the central opening 62d of the body 62 together define the plug 74. The plug 74 is completely sealed by the overmolded element 72 and is open only at the central opening 62d of the body 62. The plug 74 is a closed structure with no other openings. The overmolded element 72 eliminates any leakage paths from outside the overmolded element to the body 62, spool 64 / coil 66, washer 68, bush 70, and finally to the inside of the plug 74. Thus, the overmolded element 72 prevents water and other external corrosive contaminants (e.g., saltwater) from entering the narrow clearance space between the plug 74 of the coil assembly 60 and the inner housing 56 of the solenoid assembly 52.

[0041] An overmolded element 72 extends from the plug 74 and defines an electrical connector 76. The electrical connector 76 includes a pair of electrical terminals 76a, 76b that connect to a complementary electrical connector (not shown) connected to a power / current supply, so that one or more electrical signals can be supplied to the coil 66 to actuate the intake valve 40. The body 62 has a low-profile portion 62l that forms notches for electrically connecting both ends of the coil 66 to the pair of terminals 76a, 76b.

[0042] When the coil assembly 60 is attached to the fuel pump 20 by connecting the plug 74 of the coil assembly 60 to the inner housing 56, the spool 64, washer 68, and bush 70 extend along the intake valve bore axis 28b, and as a result, the spool 64 and associated coil 66 tightly surround the inner housing 56. Consequently, when current flows through the coil 66, the valve element 50 is magnetically attracted and moves toward the pole piece 57. When no current flows through the coil 66, the valve element 50 is moved away from the pole piece 57 by the return spring 58, thereby allowing or blocking the flow of fuel from the intake passage 41 to the pump chamber 38.

[0043] In some embodiments, a method for manufacturing an overmolded coil assembly 60 includes forming an overmolded element 72 on a spool 64, coil 66, washer 68, and bush 70, while simultaneously forming an annular slot 72a in the overmolded element 72. The overmolded element 72 is then press-fitted into the body 62, with the side wall 62j of the body 62 fitting into the annular slot 72a, and the end 72b of the overmolded element 72 engaging with an annular groove 62k on the outer surface 62a of the body 62. In this configuration, the overmolded element 72 seals around the spool 64, coil 66, washer 68, bush 70, and body 62, eliminating a leakage path to the plug 74.

[0044] It should be understood that the appended claims are not limited to the specific compounds, compositions, or methods described in the detailed description, and may vary depending on the specific embodiment within the appended claims. With respect to the groups of Markush relied upon to describe specific features or aspects of various embodiments herein, each member of each group of Markush may yield different, special, and / or unexpected results, independently of all other members of the other group. Each member of the group of Markush may be relied upon individually or in combination to provide sufficient support for the specific embodiment within the appended claims.

[0045] Furthermore, the ranges and subranges relied upon when describing various embodiments of the present invention are individually and collectively within the appended claims, and these ranges are understood to describe and consider all ranges, including whole values ​​and / or fractional values, even if such values ​​are not expressly stated herein. Those skilled in the art will readily recognize that the enumerated ranges and subranges adequately describe and enable various embodiments of the present invention, and such ranges and subranges may be further divided into relevant halves, thirds, quarters, fifths, etc. As an example, the range "0.1 to 0.9" may be further divided into a lower third, i.e., 0.1 to 0.3, a middle third, i.e., 0.4 to 0.6, and an upper third, i.e., 0.7 to 0.9, which are individually and collectively within the appended claims, and may be individually and / or collectively relied upon, and may provide sufficient support for specific embodiments within the appended claims. Furthermore, with respect to language that defines or modifies ranges such as “at least,” “greater than,” “less than,” and “not greater than,” it should be understood that such language includes subranges and / or upper or lower limits. As another example, the range “at least 10” essentially includes subranges from at least 10 to 35, from at least 10 to 25, from 25 to 35, and so on, with each subrange being relied upon individually and / or collectively to provide sufficient support for a particular embodiment within the appended claims. Finally, individual numbers within the disclosed range are relied upon to provide sufficient support for a particular embodiment within the appended claims. For example, the range “1 to 9” includes various individual integers such as 3, and individual numbers including decimals (or fractions) such as 4.1, which are relied upon to provide sufficient support for a particular embodiment within the appended claims.

[0046] The above description relates to current embodiments of the invention. Various modifications and changes can be made without departing from the spirit and broad aspects of the invention as set forth in the appended claims, and these will be interpreted in accordance with the principles of patent law, including the equivalence principle. This disclosure is presented for explanatory purposes and should not be construed as an exhaustive description of all embodiments of the invention, nor does it limit the claims to any particular element illustrated or described in relation to these embodiments. For example, any individual element of the described invention may be replaced by an alternative element that provides substantially the same function or otherwise provides suitable operation. This includes, for example, currently known alternative elements, those that may be currently known to those skilled in the art, and alternative elements that may be developed in the future, those that a person skilled in the art may recognize as alternatives at the time of development. Furthermore, the disclosed embodiments include several features that are described in conjunction and may work together to provide a set of advantages. The invention is not limited to embodiments that include all of these features or provide all of the advantages described, except to the extent expressly set forth in the published claims. When referring to components of a claim using ordinal numbers, such as "first," "second," and "third," these are used for clarity and should not be interpreted as restricting the order in which the components appear. When referring to a component element in the singular form, such as using "a," "an," "the," or "said," these should not be interpreted as limiting the element to the singular.

Claims

1. An overmolded coil assembly (60) for a fuel pump, The overmolded coil assembly is The main body (62) has a hollow cylindrical shape and includes an inner surface (62b) that defines a central opening (62d) and a recess (62c), A spool (64) to be received in the recess (62c) of the main body (62), comprising an annular barrel (64e) and having opposing first end (64a) and second end (64b), wherein the first end (64a) is adjacent to the central opening (62d) of the main body (62), and the inner surface (64f) of the annular barrel (64e) defines an axial hole (64g), The spool (64) is disposed within the annular barrel (64e) and surrounded by a coil (66) of conductive wire, A washer (68) having an inner surface (68c) and an outer surface (68d), wherein the inner surface (68c) of the washer (68) defines an axial hole (68e), and the washer (68) is adjacent to the washer (68) of the second end (64b) of the spool (64), An overmolded element (72) made of an electrical insulating material, which covers the spool (64), the coil (66), the washer (68), and the body (62), and seals the periphery of the spool (64), the coil (66), the washer (68), and the body (62), An overmolded coil assembly (60) comprising the above.

2. The overmolded coil assembly (60) according to claim 1, wherein the overmolded element (72), the axial hole (64g) of the spool (64), the axial hole (68e) of the washer (68), and the central opening (62d) of the body (62) together define the plug (74).

3. The overmolded coil assembly (60) according to claim 2, wherein the plug (74) is sealed by the overmolded element (72).

4. The overmolded coil assembly (60) according to claim 2 or 3, wherein the plug (74) is open only at the central opening (62d) of the main body (62).

5. The overmolded coil assembly (60) according to any one of claims 1 to 4, wherein the main body (62) has an outer surface (62a), and the overmolded element (72) at least partially covers the outer surface (62a) of the main body (62).

6. The overmolded coil assembly (60) according to any one of claims 1 to 5, wherein the main body (62) includes at least one annular groove (62k) at the end (72b) of the overmolded element (72).

7. The overmolded coil assembly (60) according to any one of claims 1 to 6, wherein the overmolded element (72) forms an annular slot (72a) into which a part of the main body (62) is received.

8. The overmolded coil assembly (60) according to any one of claims 1 to 7, wherein the bush (70) is adjacent to the washer (68) on the opposite side from the spool (64).

9. The overmolded coil assembly (60) according to claim 8, wherein the bush (70) has an inner annular surface (70d) defining an axial hole (70e), and the axial hole (70e) of the bush, the overmolded element (72), the axial hole (64g) of the spool (64), the axial hole (68e) of the washer (68) and the central opening (62d) of the body (62) together define a plug (74).

10. The overmolded coil assembly (60) according to any one of claims 1 to 9, wherein the outer surface (68d) of the washer (68) includes at least one notch (68f) that defines a passage (68g) through which the overmolded element (72) extends.

11. The overmolded coil assembly (60) according to claim 2, wherein the overmolded element (72) extends from the plug (74) and defines an electrical connector (76).

12. A fuel pump (20) comprising an overmolded coil assembly (60) according to any one of claims 1 to 11.

13. A fuel pump (20), A fuel pump housing (28) having a defined pump chamber (38), and an intake valve hole (28a) extending outward from the fuel pump housing (28) along the intake valve hole axis (28b), A pumping plunger (34) that reciprocates within a plunger hole (30), wherein the intake stroke of the pumping plunger (34) increases the volume of the pump chamber (38), and the compression stroke decreases the volume of the pump chamber (38), A solenoid assembly (52) that 1) selectively provides fluid communication between the intake port (20a) of the fuel pump (20) and the pump chamber (38), and 2) selectively prevents fluid communication between the intake port (20a) of the fuel pump (20) and the pump chamber (38), and the solenoid assembly (52) An inner housing (56) is received within the intake valve hole (28a) and extends to the outside of the fuel pump housing (28), A magnetic pole piece (57) made of a magnetically permeable material is located inside the inner housing (56), A solenoid assembly (52) having an overmolded coil assembly (60) according to any one of claims 1 to 11, The overmolded coil assembly (60) is coupled to the inner housing (56), the coil (66) surrounds a pole piece (57), and when electricity is applied to the coil (66), a magnetic attraction is generated between the pole piece (57) and the valve element of the solenoid assembly (52), causing the valve element to move toward the pole piece (57), in a fuel pump (20).

14. The fuel pump (20) according to claim 13, wherein the overmolded element (72), the axial hole (64g) of the spool (64), the axial hole (68e) of the washer (68), and the central opening (62d) of the body (62) together define the plug (74).

15. The fuel pump (20) according to claim 14, wherein the plug (74) is sealed by the overmolded element (72).

16. The fuel pump (20) according to claim 14 or 15, wherein the plug (74) is open only at the central opening (62d) of the main body (62).

17. The fuel pump (20) according to any one of claims 14-16, wherein the plug (74) is coupled to the inner housing (56).

18. The fuel pump (20) according to claim 13, wherein the bush (70) is adjacent to the washer (68) on the opposite side of the spool (64), the bush (70) has an inner annular surface (70d), and together the inner annular surface (70d) of the bush (70), the overmolded element (72), the axial hole (64g) of the spool (64), the axial hole (68e) of the washer (68) and the central opening (62d) of the body (62) define the plug (74).

19. The fuel pump (20) according to any one of claims 13-18, wherein the main body (62) has an outer surface (62a), and the overmolded element (72) at least partially covers the outer surface (62a) of the main body (62).

20. A method for sealing a fuel pump coil assembly, A step of providing a spool (64), wherein the spool (64) includes an annular barrel (64e) having opposing first end (64b) and second end (64b), and the inner surface (64f) of the annular barrel (64e) defines an axial hole (64g), The steps include placing the coil (66) of the electrically conductive wire inside the annular barrel (64e) of the spool (64) and surrounding it, A step of placing a washer (68) adjacent to the second end (64b) of the spool (64), wherein the washer (68) has an inner surface (68c) and an outer surface (68d), and the inner surface (68c) of the washer (68) defines an axial hole (68e), A step of positioning a bush (70) adjacent to the washer (68) on the opposite side of the spool (64), wherein the bush (70) has an inner annular surface (70d) that defines an axial hole (70e), A step of forming an overmolded element (72) made of an electrical insulating material on the spool (64), the coil (66), the washer (68), and the bush (70), wherein the overmolded element (72) covers the spool (64), the coil (66), the washer (68), and the bush (70), The steps include providing a body (62) having a hollow cylindrical shape and including an inner surface (62b) that defines a central opening (62d), an outer surface (62a), and a recess (62c), A step of press-fitting the overmolded element (72) into the body (62), wherein the spool (64), the coil (66), and the washer (68) are received in the recess (62c) of the body (62), the overmolded element (72) covers at least a portion of the outer surface (62a) of the body (62), the overmolded element (72) seals around the spool (64), the coil (66), the washer (68), the bush (70), and the body (62), defining a plug in which the overmolded element (72), the axial hole (64g) of the spool (64), the axial hole (68e) of the washer (68), and the central opening (62d) of the body (62) are together sealed by the overmolded element (72), A method for providing this.

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