WO2005061881A1

WO2005061881A1 - Electrical connector for fuel injector assembly

Info

Publication number: WO2005061881A1
Application number: PCT/US2003/037036
Authority: WO
Inventors: Gregg R. Spoolstra
Original assignee: Robert Bosch Gmbh
Priority date: 2003-11-18
Filing date: 2003-11-18
Publication date: 2005-07-07
Also published as: AU2003291578A1

Abstract

An electrical connector (10, 200) for an electrically operated fuel injector assembly (12, 150, 202) has a bracket assembly (14, 206) with a male plug (56, 222), at least one electrical conductor (38, 40, 214, 216), and a spring clip (16, 208). The electrical conductor (38, 40, 214, 216) terminates at a connector (62, 64, 228, 230) in the male plug (56, 222) and is adapted to mate with at least one terminal (112, 172, 286) in a socket (26, 174, 276) in the fuel injector assembly (12, 150, 202). The spring clip (16, 208) is disposed on the bracket assembly so that when the male plug (56, 222) mates with the terminal (112, 172, 286) in the socket (26, 174, 276), the spring clip (16, 208) will bear against the fuel injector assembly (12, 150, 202) to hold the electrical connecter (10, 200) securely in place. The resulting connection is secure and inhibits vibration of the electrical connector (10, 200) relative to the fuel injector assembly (12, 150, 202).

Description

ELECTRICAL CONNECTOR FOR FUEL INJECTOR ASSEMBLY BACKGROUND OF THE INVENTION

Field of the Invention The invention relates to fuel injector assemblies, and more particularly to electrical connections to control valves within fuel injector assemblies.

Description of the Related Art Electrically operated fuel injector assemblies typically have control valves that are activated or deactivated by a solenoid or other electrically driven armature. This is true whether the fuel injector assembly is a pump or a unit injector. In one common arrangement, the terminals of the solenoid comprise prongs that project from the solenoid or control valve. An adapter, having one or more internal conductors, is mounted to the solenoid with the conductors mating to the terminals. The adapter has a female receptacle at an angle relative to the terminals, which is adapted to receive a male plug connected to a wiring harness. In another common arrangement, a female receptacle in which prongs project extends at an angle from the case in which the solenoid or control valve is located. The prongs are internally connected to the solenoid terminals. A male connecter has sockets corresponding to the prongs and is otherwise connected to a wiring harness that provides electrical current. In either arrangement, electrical connection is provided by inserting the male plug into the female receptacle with the sockets engaging the prongs. In all known arrangements for fuel injector assemblies, the female receptacle is at an angle relative to the terminals and to the longitudinal axis of the fuel injector assembly, whether it is a pump or a unit injector. Consequently, it has been found that the connection is subject to significant vibration during operation of the fuel injector assembly. Such vibration aggravates fretting and corrosion of the contacts so that premature failure of the connection is not uncommon. There is a need to improve the durability and security of the electrical connections to the solenoid in a fuel injector assembly. SUMMARY OF THE INVENTION In accord with the invention, an electrical connector is provided for an electrically operated fuel injector assembly having at least one terminal extending into a socket. The electrical connector is characterized by a bracket assembly having a male plug, at least one electrical conductor, and a spring clip. The electrical conductor terminates at a connector in the male plug and is adapted to mate with at least one terminal in the socket. The spring clip is disposed on the bracket assembly so that when the male plug mates with the terminal in the socket, the spring clip will bear against the fuel injector assembly to hold the electrical connecter securely in place and to minimize vibration of the electrical connector relative to the fuel injector assembly. The fuel injector assembly typically has a longitudinal axis and the male plug is disposed on the bracket so as to be parallel to the longitudinal axis when the electrical connector is secured to the fuel injector assembly. Preferably, the male plug will be within the exterior contour of the fuel injector assembly when the electrical connector is secured to the fuel injector assembly. Also, preferably, the bracket assembly comprises a case molded of glass-filled polymer. In one aspect of the invention, the spring clip includes a long arm having a securing tab, and a short arm having a spring section. The securing tab can retain the electrical connector securely to the fuel injector assembly against the force of the spring section. In another aspect of the invention, the spring clip has a bight section and is pivotably mounted to the bracket assembly. Thus, it can be rotated to a position where the bight section bears against the fuel injector assembly to retain the electrical connector securely to the fuel injector assembly against the force of the bight section. Here, the bracket assembly preferably has a brace that is positioned to bear against the fuel injector assembly opposite the bight section. The invention is applicable where the fuel injector assembly is a unit injector, a fuel injector pump, or an inline unit injector. Typically the socket will be either in an end of the fuel injector assembly, or in a side of the fuel injector assembly. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: Fig. 1 is an exploded view of an electrical connector according to the invention in association with a fuel injector pump. Fig. 2 is a top perspective view of the electrical connector of Fig. 1 with parts broken away for clarity. Fig. 3 is a bottom perspective view of the electrical connector of Fig. 1. Fig. 4 is a cross sectional view of a fuel injector pump incorporating an electrical connector according to the invention. Fig. 5 is an exploded view of the electrical connector according to the invention. Fig. 6 is a cross sectional view of a unit fuel injector assembly incorporating an electrical connector according to the invention. Fig. 7 is a cross sectional view of an electrical connector according to the invention, taken along lines 7-7 of Fig. 1. Fig. 8 is a top plan view of a portion of the unit fuel injector assembly of Fig. 6, taken along lines 8-8. Fig. 9 is a perspective view of another embodiment of an electrical connector according to the invention. Fig. 10 is a cross sectional view of an inline unit fuel injector with an electrical connector of the type illustrated in Fig. 9. Fig. 11 is a cross sectional exploded view of the inline unit injector and electrical connector of Fig. 10.

DETAILED DESCRIPTION Fig. 1 illustrates, in exploded view, an electrical connector 10 according to the invention, as it would be used in conjunction with a fuel injector pump 12. The electrical connector 10 comprises a bracket assembly 14 and a clip 16. The fuel injector pump 12 comprises generally a pump body 18 with a bracket 20 adapted to mount the fuel injector pump to a fuel injector (not shown) or to an engine. A proximal end 22 of the pump body 18 includes a port 24 adapted to fluidly connect to a high pressure conduit in a fuel injector, and a female socket 26 serves to provide an electrical connection between the connector 10 and a solenoid internal to the pump body. It will be understood that the invention is not limited to a solenoid operated pump, but rather encompasses any electrically operated actuator, such as piezoelectric, electrorestrictive, magnetorestrictive or solid state devices. An annular lip 28 near the proximal end 22 provides another point of attachment for the connector 10 as explained below. It will be seen that the components of the fuel injector pump 12 are generally aligned on a longitudinal axis 29. Turning now to Figs. 2 and 3, the bracket assembly 14 comprises a generally J- shaped case 30 having a long leg 32, a medial leg 34, and a short leg 36. The case 30 is preferably an integrally molded piece made of a glass-filled polymer. Molded into the case 30 is a pair of electrical conductors 38, 40 having respective extensions 42, 44 that are connected directly to a source of electric current (not shown). The medial leg 34 has a recess 46 on the outer side of the case 30 between the conductors 38, 40, and a slot 48 at one end of the recess, adjacent the long leg 32. A channel 50 extends longitudinally on the inner side of the long leg 32 from a shoulder 52, which is spaced from the slot 48 to a tab end 53. Reinforcing gussets 54 may be provided on an inner side of the medial leg 34 between the long leg 32 and the short leg 36. Extending from the short leg 36 is a male plug 56 having a pair of holes 58, 60 side-by-side. The conductor 42 connects to a female connector 62 in one hole 58, and the other conductor 44 connects to a female connector 64 in the other hole 60. Preferably, the female connectors 62, 64 are completely within the holes 58, 60 and do not extend beyond the male plug 56. Turning now to Figs. 5 and 7, it can be seen that the clip 16 is received in the bracket assembly 14 through the slot 48. The clip 16 is made of spring steel and roughly L-shaped, having a long arm 70 and a short arm 72. The long arm 70 has a first face 74 that abuts the inner side of the long leg 32, and a second face 76 that faces away from the long leg 32. The short arm 72 comprises a spring section 78 and a distal end 80. An attachment tab 82 extends from the first face 74 to assist in attaching the clip 16 to the bracket assembly 14. The attachment tab 82 is spaced from the spring section 78 roughly the same distance as the shoulder 52 is spaced from the slot 48 on the bracket assembly 14. A securing tab 84 extends from the second face 76 to assist in mounting the connector 10 to the fuel injector pump 12. When the clip 16 is mounted to the bracket assembly 14, the long arm 70 extends through the slot 48, parallel and adjacent to the long leg 32. The short arm 72 is received within the recess 46 where the end 80 bears against the medial leg 34. The attachment tab 82 snaps in place behind the shoulder 52 against the spring force of the spring section 78 so that the clip 16 remains firmly attached to the bracket assembly 14. A gasket 86 is provided around the male plug 56 to seal the resulting connection against contaminants. Fig. 4 shows, in cross section, the unit pump 12 of Fig. 1 with the connector 10 mounted to it. The pump body 18 defines a high-pressure pumping chamber 90. A plunger 92 is disposed in the pumping chamber for pressurizing fuel. The port 22 connects to an injector 94 through a high-pressure line 96. The port 22 is connected to the pumping chamber 90 by a high-pressure fluid line 98. An electrically operated solenoid actuated control valve 100 selectively routes pressurized fuel from the pumping chamber 90 to the port 22 when closed, or when open, provides pressure relief to the pumping chamber in a well-known manner. The plunger 56 has a tail end 102 received in a spring seat 104. A plunger spring 106, compressed between the pump body 18 and the spring seat 104, biases the plunger 92 to a retracted position as shown by solid lines in Fig. 4. The plunger 92 may be driven to an extended position (shown in phantom) by an engine driven cam (not shown). A cam follower assembly 108 receives the spring seat 104 and has a cam roller 110 that is driven by the engine driven cam to urge the plunger 92 to the extended position, compressing fuel in the pumping chamber. As the plunger is continuously driven from the retracted to the extended position, the control valve 100 is controlled to selectively supply fuel at various pressures to the port 22, and to the injector 94. The solenoid actuated control valve 100 receives current by way of terminals 112 that extend into the female socket 26 as prongs 113. When the electrical connector 10 is mounted to the pump body 18, the male plug 56 is received within the female socket 26, with one of the prongs 113 simultaneously received within each of the female connectors 62, 64. The respective dimensions of the male plug 56, female socket 26, female connectors 62, 64 and prongs 113 are such that the resulting connection is preferably tight. The gasket 86 bears against the proximal end 22 to preferably provide a watertight seal for the connection. Simultaneously, the securing tab 84 snaps behind the annular lip 28 to firmly secure the electrical connector to the pump body 18. Also, the bracket 20 has an annular lip 114 that defines an annular groove 116 between the lip 114 and the side of the pump body 18. The tab end 53 is received in the annular groove 116. It will be apparent that the connector 10 has a low mass. Preferably, the contour of the connector 10 is complementary to the cross sectional profile of the pump body 18 so that the connector effectively "hugs" the pump body. Also, the male plug 56 will be parallel to the longitudinal axis 29. Consequently, the shape, low mass, and attachment arrangement of the connector 10 minimize vibration at the connection. Looking now at Figs. 6, 7 and 8, an embodiment of an electromagnetic unit fuel injector assembly 150 is shown incorporating an electrical connector 10 according to the invention. The electromagnetic unit fuel injector assembly 150 has a longitudinal axis 151 and includes a pump body 152 that has a vertical main body portion 157, which slideably receives a pump plunger 158. A plunger actuator follower 160 connects to the pump plunger 158, and is adapted to be reciprocated by an engine driven cam or rocker as conventionally known in the art, under the bias of a plunger return spring 162. A nut, generally indicated at 164, is threaded to the lower end of the main body portion 154 and secures an injector assembly 166 to it. The delivery of fuel from a source such as a fuel tank to the injector assembly 166 is controlled by means of a solenoid actuated, pressure balanced valve, generally indicated at 168 in the side body portion 156. Operation of the valve 168 is effected by means of a solenoid assembly, generally indicated at 170. The solenoid assembly 170 is mounted to the side body portion 156 by four bolts 180. An annular lip 182 extending from the solenoid assembly 170 or from the side body portion 156 defines a groove 184 adjacent to a side wall of the solenoid assembly 170 or the side body portion 156 (as the case may be). The solenoid assembly 170 typically includes an armature for actuating the valve 168 in response to electrical excitation of a stator assembly 170. Terminals 172 extend from the solenoid assembly 170 into a female socket 174 as prongs 176. When the electrical connector 10 is mounted to the solenoid assembly 170 or to the side body portion 156 (as the case may be), the male plug 56 is received within the female socket 174, with one of the prongs 176 simultaneously received within each of the female connectors 62, 64. The respective dimensions of the male plug 56, female socket 174, female connectors 62, 64 and prongs 176 are such that the resulting connection is preferably tight. The gasket 86 bears against an upper end 178 of the side body to preferably provide a water-tight seal for the connection. Simultaneously, the securing tab 84 snaps behind an annular lip or detent 180 on the outside of the side body portion 156 to firmly secure the electrical connector to the side body portion 156. Also, the tab end 53 is received within the groove 184. Preferably, the contour of the connector 10 is complementary to the cross sectional profile of the side body portion 156 so that the connector effectively "hugs" the side body portion 156. Also, the male plug 56 will be parallel to the longitudinal axis 151. Consequently as in the earlier embodiment, the shape, low mass, and attachment arrangement of the connector 10 minimize vibration at the connection. Figs. 9-11 illustrate another embodiment of an electrical connector according to the invention as it may be found in another type of fuel injector. Here, an electrical connector 200 is adapted to connect to an inline fuel injector assembly 202 having a generally longitudinal axis 204. Looking first at Fig. 9, the electrical connector 200 comprises a bracket assembly 206 and a clip 208. The bracket assembly 206 comprises a generally L-shaped case 210 having a brace 212 projecting therefrom. The case 210 is preferably an integrally molded piece made of a glass-filled polymer. The brace 212 can be integrally molded with the case 210, or it can be separately molded or fabricated and assembled to the case. Molded into the case 210, and forming one leg 211 of the L-shape, is a pair of electrical conductors 214, 216 having respective extensions 218, 220 that are connected directly to a source of electrical current (not shown). Extending at a right angle from the one leg 211, is a second leg 221 comprising a male plug 222 having a pair of holes 224, 226 side-by-side. A groove 290 in the second leg 221 accommodates a seal 300. The conductor 214 connects to a female connector 228 in one hole 224, and the other conductor 216 connects to a female connector 230 in the other hole 226. Preferably, the female connectors 228, 230 are completely within the holes 224, 226 and do not extend beyond the male plug 222. The brace 212 comprises a pair of arms 232, 234 extending parallel to the one leg 211. Each arm 232, 234 has an extension 236, 238 that curves approximately 90 degrees so that the distal ends 240, 242 project roughly parallel to the second leg 221. A pin 244 extends between the arms 232, 234 and a brace bar 246 extends between the distal ends 240, 242. Preferably, as shown, reinforcing posts 248, 250 extend parallel to the second leg 221 from the arms 232, 234 where the pin 244 is located. Additional brace bars 252, 254, 256 can connect the reinforcing posts 248, 250 to each other and to the distal ends 240, 242. The clip 208 comprises a U-shaped piece of spring steel wherein a first end 258 is rotatably mounted to the pin 244, and the other end 260 has a tab 262 to facilitate manual manipulation of the clip. The clip 208 is mounted so that its bight section 264 can extend between the extensions 218, 220 and will project away from the brace 212. Looking now at Figs. 9, 10 and 11, it will be seen how the electrical connector 200 connects to the fuel injector assembly 202. The in-line fuel injector assembly 202 has a pump section 270 and an adapter section 272. An electrically operated control valve 274 is disposed in the adapter section 272 at the interface with a pump section 270. The pump section 270 has an L-shaped socket 276 comprising a smaller segment 278 that is open to the adapter section 272, and a larger segment 280 that is open to a side 277 of the injector assembly 202. The larger segment 280 is bounded by an upper wall 282 and a lower wall 284 that are spaced apart far enough from each other so that the electrical connector 200 can easily pass between them. Electrical terminals 286 extend into the smaller segment 278 from the control valve actuator 274 and terminate at a pair of prongs 288. To provide power to the control valve actuator 274, the electrical connector 200 is received in the larger segment 280 and then urged downwardly so that the male plug 222 is received in the smaller segment 278, with the prongs 288 simultaneously received within the female connectors 228, 230. The respective dimensions of the male plug 222, the smaller segment 278, the female connectors 228, 230, the prongs 288,and the seal 300 are such that the resulting connection is preferably tight. The male plug 222 is parallel to the longitudinal axis 204. To further secure the electrical connector 200 within the socket 276 and minimize vibration, the clip 208 is rotated until the bight section 264 bears against the upper wall 282, which in turn forces the brace 212 against the lower wall 284. Preferably, the clip 208 can be urged further in rotation until the maximum pressure is exerted by the clip against the upper wall 282 and the brace against the lower wall 284. The shape of the clip 208 is such that when the structure is exposed to any vibration (as would occur in normal engine operation), the clip will tend to be urged into further engagement. While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and the scope of the appended claims should be construed as broadly as the prior art will permit.

Claims

CLAIMS What is claimed is:

1. An electrical connector (10, 200) for an electrically operated fuel injector assembly (12, 150, 202) having at least one terminal (112, 172, 286) extending into a socket (26, 174, 276), characterized by a bracket assembly (14, 206) having a male plug (56, 222), at least one electrical conductor (38, 40, 214, 216), and a spring clip (16, 208) wherein the electrical conductor terminates at a connector (62, 64, 228, 230) in the male plug (56, 222) adapted to mate with at least one teiminal

(112, 172, 286) in the socket (26, 174, 276), and the spring clip (16, 208) is disposed on the bracket assembly (14, 206) so that when the male plug (56, 222) mates with the terminal (112, 172, 286) in the socket (26, 174, 276), the spring clip (16, 208) will bear against the fuel injector assembly (12, 150, 202) to hold the electrical connecter (10. 200) securely in place and to minimize vibration of the electrical connector (10, 200) relative to the fuel injector assembly (12, 150, 202).

2. An electrical connector (10, 200) according to claim 1 wherein the fuel injector assembly (12, 150, 202) has a longitudinal axis (29, 151, 204) and the male plug (56, 222) is disposed on the bracket assembly (14, 206) so as to be parallel to the longitudinal axis (29, 151, 204) when the electrical connector (10, 200) is secured to the fuel injector assembly (12, 150, 202).

3. An electrical connector (10, 200) according to claims 1 or 2 wherein the male plug (56, 222) is within the exterior contour of the fuel injector assembly (12, 150, 202) when the electrical connector (10, 200) is secured to the fuel injector assembly (12, 150, 202).

4. An electrical connector (10, 200) according to claims 1-3 wherein the bracket assembly (14, 206) comprises a case (30, 210) molded of glass-filled polymer.

5. An electrical connector (10) according to claims 1-4 wherein the spring clip (16) comprises a long arm (70) having a securing tab (84), and a short arm (72) having a spring section (78), whereby the securing tab (84) can retain the electrical connector (10) securely to the fuel injector assembly (12, 150) against the force of the spring section (78).

6. An electrical connector (200) according to claims 1-4 wherein the spring clip (208) has a bight section (264) and is pivotably mounted to the bracket assembly (206) so that it can be rotated to a position where the bight section (264) bears against the fuel injector assembly (202) to retain the electrical connector (200) securely to the fuel injector assembly (202) against the force of the bight section (264).

7. An electrical connector (200) according to claim 6 wherein the bracket assembly (206) has a brace (212) that is positioned to bear against the fuel injector assembly (202) opposite the bight section (264).

8. An electrical connector (10, 200) according to claims 1-7 wherein the fuel injector assembly is a unit injector (150, 202).

9. An electrical connector (10) according to claims 1-5 wherein the fuel injector assembly is a fuel injector pump (12).

10. An electrical connector (10, 200) according to claim 9 wherein the socket (26, 174) is in an end (22, 178) of the fuel injector assembly (12, 150).

11. An electrical connector (200) according to claim 1 -4 and 6-8 wherein the fuel injector assembly is an inline unit injector (202).

12. An electrical connector (200) according to claim 11 wherein the socket (276) is in a side (277) of the fuel injector assembly (202).

13. An electrical connector (10, 200) according to any of claims 1-12 characterized by the bracket assembly (14, 206) and clip (16, 208) together having low mass.