Method for matching the spool valve lands in a fuel injector

• US 6,174,219 B1
• Filed: 07/23/1999
• Issued: 01/16/2001
• Est. Priority Date: 07/23/1999
• Status: Expired due to Term

• Current Assignee: International Engine Intellectual Property Company, LLC (Volkswagen AG)
• Original Assignee: Navistar International Transportation Corp. (Volkswagen AG)
• Inventors: Mathews, Will W.
• Primary Examiner(s): Scherbel, David A.
• Assistant Examiner(s): Shakeri, Hadi
• Application Number:
  US09/360,878
• Time in Patent Office: 543 Days
• Field of Search: 451/5, 451/6, 451/8, 451/28, 451/51, 731/19.A
• US Class Current: 451/8
• CPC Class Codes: B24B 15/04 on valve members
• CPC Class Codes: F02M 57/025 hydraulic, e.g. with pressure amplification
• CPC Class Codes: F02M 59/105 hydraulic drive F02M59/32 takes precedence
• CPC Class Codes: F02M 59/44 Details, components parts, or accessories not provided for in, or of interest apart from, the apparatus of groups F02M59/02 - F02M59/42; Pumps having transducers, e.g. to measure displacement of pump rack or piston
• CPC Class Codes: F02M 59/466 Electrically operated valves, e.g. using electromagnetic or piezoelectric operating means
• CPC Class Codes: F02M 59/48 Assembling; Disassembling; Replacing
• CPC Class Codes: F16K 11/0716 with fluid passages through the valve member F16K11/0704, F16K11/0708, F16K11/0712 take precedence

Abstract

A method is described for matching the lands in a spool valve (300) for a fuel injector. The spool valve (300) has a valve body (340) forming an inside surface (373) to receive the spool (310). The inside surface is measured to locate the position of contact points on the valve body (340). A starting contact point (514) is selected from the contact points on the valve body (340). The starting contact point (514) is transposed to the spool (310). The other contact points are transposed to the spool (300), preferably by using the distances between the other contact points and the starting contact point on the valve body. Grind areas are identified on the spool (310) based on the starting contact point, the other contact points, and specifications for the spool. The grind areas are ground to form lands on the spool (310) that match lands on the valve body (340). Alternatively, the lands on the valve body (340) are made based on the contact points of the spool (310)

Claims

1. A method for matching lands in a spool valve for a fuel injector, wherein the spool valve has a valve body forming an inside surface having an inside diameter to receive a spool having outside diameter, specifications defining the inside surface of the valve body, the valve body having a contact point at a location where a body land connects with a spool land formed by a spool groove on the spool, the method comprising the steps of:

(a) measuring the inside surface;

(b) determining the location of the contact point on the valve body;

(c) identifying a grind area on the spool based on the location of the contact point on the valve body; and

(d) grinding the grind area to form the spool groove and the spool land.

2. A method according to claim 1, wherein the step (a) of measuring the inside surface further comprises the substep of moving a measurement device axially along the inside surface.

3. A method according to claim 2, wherein the step (a) of measuring the inside surface further comprises the substep of rotating the valve body.

4. A method according to claim 1, wherein the step (a) of measuring the inside surface further comprises the substep of confirming that the inside surface conforms to specification for the valve body.

5. A method according to claim 1, wherein the step (a) of measuring the inside surface further comprises the substep of grinding the outside diameter of the spool to match the diameter of the inside surface.

6. A method according to claim 1, wherein the step (b) of determining the location further comprises the substeps of;

(b1) identifying start and end positions of the body land; and

(b2) comparing the start and end positions to specifications for the valve body.

7. A method according to claim 6, wherein the substep (b1) of identifying start and end positions includes performing a mean best-fit plane approximation technique.

8. A method according to claim 1, wherein the step (c) of identifying a grind area further comprises the substeps of:

(c1) transposing the location of the contact point from the valve body onto the spool; and

(c2) determining the grind area according to the location of the contact point on the spool and specifications for the spool.

9. A method according to claim 8, wherein the substep (c1) of transposing the location includes determining the location of the contact point on the valve body and the location of the contact point on the spool in relation to a reference position.

10. A method according to claim 9, wherein the reference position is an edge of the valve body aligned with a datum of the spool.

11. A method according to claim 8, wherein the substep (c1) of transposing the location includes adjusting the location of the contact point on the spool.

12. A method according to claim 1, further comprising the step of:

(e) qualifying at least one datum based upon the location of the contact point.

13. A method for matching lands in a spool valve for a fuel injector, wherein the spool valve includes a valve body forming an inside surface to receive a spool, the valve body having a first contact point at a first location where a first body land connects with a first spool land formed by a first spool groove on the spool, the valve body having a second contact point at a second location where a second body land connects with a second spool land formed by a second spool groove on the spool, the method comprising the steps of:

(a) measuring the inside surface;

(b) determining the first location and the second location on the valve body;

(c) identifying a first grind area and a second grind area on the spool, the first grind area based on the first location, the second grind area based on the second location; and

(d) grinding the first grind area and the second grind area, wherein grinding the first grind area forms the first spool groove and the first spool land, and wherein grinding the second grind area forms the second spool grove and the second spool land.

14. A method according to claim 13, wherein the step (b) of determining the first location and the second location further comprises the substep of performing a mean best-fit plane approximation technique.

15. A method according to claim 13, wherein the step (c) of identifying a first grind area and a second grind area further comprises the substep of identifying the first grind area and the second grind area sequentially.

16. A method according to claim 13, wherein the step (c) of identifying a first grind area and a second grind area further comprises the substeps of:

(c1) ascertaining the location of the first contact point on the spool;

(c2) determining the first grind area according to the location of the first contact point on the spool and specifications for the spool;

(c3) transposing the location of the second contact point from the valve body onto the spool; and

(c4) determining the second grind area according to the location of the second contact point on the spool and specifications for the spool.

17. A method according to claim 16, wherein the substep (c1) of ascertaining the location includes transposing the location of the first contact point from the valve body onto the spool by determining the location of the first contact point on the valve body and the location of the first contact point on the spool in relation to a reference position.

18. A method according to claim 16, wherein the substep (c3) of transposing the location includes determining the locaton of the second contact point on the valve body and the location of the second contact point on the spool in relation to a reference position.

19. A method according to claim 16, wherein the substep (c1) of ascertaining the location includes selecting an arbitrary position on the spool as the location of the first contact point on the spool.

20. A method according to claim 16, wherein the substep (c3) of transposing the location includes determining the location of the second contact point on the spool based upon the distance between the first contact point and the second contact point on the valve body.

21. A method according to claim 16, wherein the substep (c3) of transposing the location includes determining the location of the second contact point on the spool based upon the distance between the first contact point and the second contact point on the valve body.

22. A method according to claim 18, wherein the substep (c3) of transposing the location includes adjusting the location of the second contact point on the spool.

23. A method according to claim 18, wherein the substep (c4) of determining the second grind area includes determining the second grind area based upon the location of the first contact point on the spool.

24. A method according to claim 13, wherein the step (d) of grinding the first grind area and the second grind area further comprises the substep of grinding the first grind area and the second grind area sequentially.

25. A method according to claim 15, further comprising the step of:

(e) qualifying at least one datum based upon the location of one of the contact points on the spool.

26. A method for matching lands in a spool valve for a fuel injector, wherein the spool valve has a valve body forming an inside surface having an inside diameter to receive a spool having an outside diameter and specifications defining the spool, the valve body having a plurality of contact points at locations where a plurality of body lands connect with a plurality of spool lands formed by a plurality of spool grooves on the spool, the method comprising the steps of:

(a) measuring the inside surface;

(b) determining the locations of the plurality of contact points on the valve body;

(c) identifying a plurality of grind areas on the spool based on the locations of the plurality of contact points on the valve body; and

(d) grinding the plurality of grind areas to form the plurality of spool grooves and the plurality of spool lands.

27. A method according to claim 26, wherein the step (c) of identifying a plurality of grind areas further comprises the substeps of:

(c1) transposing the locations of the plurality of contact points from the valve body onto the spool; and

(c2) determining the plurality of grind areas according to the locations of the plurality of contact points on the spool and specifications for the spool.

28. A method according to claim 26, wherein the step (c) of identifying a plurality of grind areas further comprises the substeps of:

(c1) selecting a starting contact point from the plurality of contact points on the valve body;

(c2) ascertaining the location of the starting contact point on the spool;

(c3) transposing the locations of the remaining plurality of contact points onto the spool based on the positions of the remaining plurality of contact points in relation to the starting contact point; and

(c4) determining the plurality of grind areas according to the location of the starting contact point, the locations of the remaining plurality of contact points, and specifications for the spool.

29. A method according to claim 28, wherein the substep (c2) of ascertaining the location includes transposing the location of the starting contact point from the valve body to the spool.

30. A method according to claim 29, wherein the substep (c2) of ascertaining the location further includes determining the location of the starting contact point on the valve body and the location of the starting contact point on the spool in relation to a reference position.

31. A method according to claim 28, wherein the substep (c2) of ascertaining the location includes selecting an arbitrary position on the spool as the location of the starting contact point on the spool.

32. A method according to claim 28, wherein the substep (c3) of transposing the locations includes adjusting at least one location of the remaining plurality of contact points on the spool.

33. A method according to claim 26, further comprising the step of:

(e) grinding at least one datum based upon the location of one of the plurality of contact points.

34. A method for matching lands in a spool valve for a fuel injector, wherein the spool valve includes a valve body having an inside diameter for receiving a spool with an outside diameter, the spool having at least one contact point where at least one spool land connects with at least one body land formed by at least one body groove on the valve body, the method comprising the steps of:

(a) measuring the outside diameter;

(b) determining the location of the at least one contact point on the spool;

(c) identifying at least one grind area on the valve body, the at least one grind area based on the location of at least one contact point on the spool; and

(d) grinding the at least one grind area to form the at least one body groove and the at least one body land.

35. A method according to claim 34, wherein the step (a) of measuring the outside diameter comprises the substep of measuring the outside diameter of the spool.

36. A method according to claim 34, wherein the step (c) of identifying at least one grind area comprises the substeps of:

(c1) transposing the location of the at least one contact point from the spool onto the valve body; and

(c2) determining the least one grind area according to the location of the at least one contact point and specifications for the valve body.

37. A method according to claim 36, wherein the substep (c1) of transposing the location includes determining the location of the at least one contact point on the spool and the location of the at least one contact point on the valve body in relation to a reference position.

38. A method according to claim 36, wherein the substep (c1) of transposing the location includes adjusting the location of the at least one contact point on the valve body.