Conduit Arrangement in a Control Valve Module for a Fuel Injector Assembly

Abstract

A control valve module (14′) for a fuel injector assembly (10) has a conduit arrangement where a high-pressure passage (108) has a first portion (110) extending linearly between an annulus (106) surrounding the control valve cylinder (42) and an upper edge (34), and a second portion (112) extending linearly between the annulus (106) and a lower edge (35′).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a cross-sectional view of a fuel injector assembly in the prior art.

FIG. 2 is a cross-sectional view of a fuel injector assembly incorporating the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Looking now more closely at FIG. 2, it can be seen that the overall relative arrangement of conventional components in the fuel injector assembly of FIG. 1 remains. Consequently like components will bear like reference numerals to those of FIG. 1. Turning now to the invention, it will be apparent that a conduit arrangement 100 in the control valve module 14′ is new. Moreover, the interface between the pump body 22′ and the control valve module 14′ is new. The large recess 33 in which the control valve module 14 is received in the fuel injector assembly of the prior art is eliminated. A smaller recess 102 is provided in the pump body 22′ with clearance to accommodate enclosing a portion of the stator assembly 36. A facing recess 104 in the upper edge 34′ of the control valve module 14′ cooperates with the recess 102 to completely enclose the stator assembly 36. A high-pressure annulus 106 surrounds and is in communication with the cylindrical chamber 42 containing the control valve 40. A high-pressure passage 108 comprises a first portion 110 extending linearly between the upper edge 34′, where it communicates with the high-pressure passage 30 in the pump body 22′, and the high-pressure annulus 106. The high-pressure passage 108 also comprises a second portion 112 extending linearly between the high-pressure annulus 106 and the lower edge 35′ of the control valve module 14′, where it communicates with the high-pressure passage 52 in the spring cage assembly 16.

Manufacture of the pump body and the control valve module are simpler because of the invention. Conventional machining processes can form the facing recess 104 and the cylindrical chamber 42, as well as the upper edge 34′. Precision machining is unnecessary because the recess 102 and facing recess 104 are adequate to center the stator assembly 36. Conventional machining and grinding are adequate to obtain the necessary tolerances for the upper edge 34′ on the control valve module 14′.

Formation of the conduit arrangement 100 can be accomplished by drilling at an oblique angle from the upper edge 34′ to a point where the high-pressure annulus 106 is to be formed at an intersection with the cylindrical chamber 42, and also drilling at an oblique angle from the lower edge 35′ to the same point. Applying a single ECM process at the intersection will form the high-pressure annulus 106.

It can be seen that the conduit arrangement 100 according to the invention enables a simpler and less costly manufacturing process. It eliminates the need for drilling and reaming a close tolerance cross passage, and then plugging the passage. It also eliminates one ECM process. It further eliminates a precision grinding process, otherwise required in the large recess 33. It has been found that with a new conduit arrangement 100 according to the invention, hydraulic performance is improved, strength of the junction of the nozzle nut with the pump body is increased, and electrical connections to the stator assembly can be made more easily and securely during assembly.

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

1. A control valve module for a fuel injector assembly for an internal combustion engine, the fuel injector assembly having a pump body with a high-pressure passage and a spring cage assembly with a high-pressure passage, wherein the control valve module is adapted to be interposed between the pump body, with an upper edge facing the pump body and a lower edge facing the spring cage assembly, and wherein the control valve module further has a facing recess to accommodate at least a portion of a stator assembly with a cylindrical chamber extending into the valve module from the facing recess, with an annulus surrounding the cylindrical chamber, and with a high-pressure passage, characterized by: the control valve high-pressure passage having a first portion extending linearly between the annulus and the upper edge where it is positioned to communicate with the pump body high-pressure passage, and a second portion extending linearly between the annulus and the lower edge where it is positioned to communicate with the spring cage assembly high-pressure passage.

2. A control valve module according to claim 1 wherein the first portion and second portion extend relative to each other at an angle other than 180 degrees.

3. A control valve module according to claim 1 wherein the pump body is provided with a recess to accommodate at least portion of the stator assembly so that the recess and the facing recess fully enclose and retain the stator assembly when the control valve module is assembled to the pump body.

4. A fuel injector assembly for an internal combustion engine, the fuel injector assembly having a pump body with a high-pressure passage, a spring cage assembly with a high-pressure passage, and a control valve module between the pump body and the spring cage assembly, with an upper edge facing the pump body and a lower edge facing the spring cage assembly, and wherein the control valve module has a facing recess to accommodate at least a portion of a stator assembly with a cylindrical chamber extending into the valve module from the facing recess, with an annulus surrounding the cylindrical chamber, and with a high-pressure passageway, characterized by: the control valve high-pressure passage having a first portion extending linearly between the annulus and the upper edge where it is positioned to communicate with the pump body high-pressure passage, and a second portion extending linearly between the annulus and the lower edge where it is positioned to communicate with the spring cage assembly high-pressure passage.

5. A fuel injector assembly according to claim 4 wherein the pump body has a recess to accommodate at least portion of the stator assembly so that the recess and the facing recess fully enclose and retain the stator assembly.

6. A fuel injector assembly according to claim 4 wherein the first portion and second portion extend relative to each other at an angle other than 180 degrees.

7. A method of making a control valve module for a fuel injector assembly for an internal combustion engine comprising the steps of: providing a metal block with a machined upper edge and machined lower edge;machining a facing recess into the upper edge with a cylindrical chamber extending therefrom;drilling a first portion of a conduit from the upper edge to an intersection point at the cylindrical chamber;drilling a second portion of a conduit from the lower edge to the intersection point; and electro chemically machining an annulus surrounding the cylindrical chamber at the intersection point.