Method of remanufacturing a prechamber assembly

Patent metadata

Field	Value
Publication number	US-10662865-B2
Application number	US-201715651231-A
Country	US
Kind code	B2
Filing date	Jul 17, 2017
Priority date	Aug 31, 2016
Publication date	May 26, 2020
Grant date	May 26, 2020

Abstract

A method of remanufacturing a prechamber assembly includes determining a width W of an original circumferential weld bead that extends around and joins a proximal end of an outer peripheral wall of a prechamber housing and a distal end of an outer peripheral wall of a body assembly, cutting through the weld bead in order to separate the prechamber housing from the body assembly, and removing material from an outer peripheral portion of a distal end portion of the body assembly. The method includes removing the material in an axial direction parallel to the central axis of the prechamber assembly for a distance that is from 2.5-3 times the width W.

First claim

What is claimed is:

1. A method of remanufacturing a prechamber assembly, the prechamber assembly including a prechamber housing welded to a body assembly, wherein one of a distal end portion of the body assembly and a proximal end portion of the prechamber housing includes a reduced diameter portion, the other includes a counterbore configured to receive the reduced diameter portion, and an original circumferential weld bead extends around and joins a proximal end of an outer peripheral wall of the prechamber housing and a distal end of an outer peripheral wall of the body assembly along an original circumferential weld joint, the method comprising:
determining a width W of the original circumferential weld bead as measured in an axial direction parallel to a central axis of the prechamber assembly;
cutting through the weld bead in order to separate the prechamber housing from the body assembly;
removing material from an outer peripheral portion of the distal end portion of the body assembly; wherein the material is removed in an axial direction parallel to the central axis of the prechamber assembly for a distance that is from 2.5-3 times the width W; and
removing a heat affected zone of the original circumferential weld bead extending circumferentially around the central axis, based on the removal of material from an outer peripheral portion of the distal end portion of the body assemble.

2. The method of claim 1 , further including:
removing material from the outer peripheral portion of the distal end portion of the body assembly, wherein the material is removed in a radial direction relative to the central axis of the prechamber assembly for a distance that is from 1.2-2.0 times the width W.

3. The method of claim 2 , further including providing a new prechamber housing including one of a counterbore or a reduced diameter portion at a proximal end of the new prechamber housing, wherein the one of the counterbore or the reduced diameter portion of the new prechamber housing is configured to form a press fit with one of a reduced diameter portion or a counterbore, respectively, at a distal end portion of the body assembly.

4. The method of claim 3 , wherein the one of the counterbore or the reduced diameter portion at the proximal end of the new prechamber housing is configured to mate along an axial length of the one of the reduced diameter portion or the counterbore, respectively, at the distal end portion of the body assembly to form a cylindrical press fit interface.

5. The method of claim 1 , wherein:
the distal end portion of the body assembly includes the reduced diameter portion, and the proximal end portion of the prechamber housing includes the counterbore; and
material is removed from the outer peripheral portion of the distal end portion of the body assembly to extend the axial length of the reduced diameter distal end portion of the body assembly by a distance that is 2.5-3 times the width W.

6. The method of claim 5 , wherein material is removed from the outer peripheral portion of the distal end portion of the body assembly in a radially, inward direction relative to the central axis of the prechamber assembly for a distance ranging from 1.2-2.0 times the width W to form the reduced diameter distal end portion of the body assembly.

7. The method of claim 6 , further including providing a new prechamber housing including a counterbore at a proximal end portion of the new prechamber housing wherein the counterbore is configured to form a press fit with the reduced diameter distal end portion of the body assembly.

8. The method of claim 7 , further including removing material from the distal end of the outer peripheral wall of the body assembly and from the proximal end of the outer peripheral wall of the new prechamber housing to form mirror-image circumferential weld cut-out chamfers around the distal end of the body assembly and around the proximal end of the new prechamber housing.

9. The method of claim 8 , further including:
press-fitting the reduced diameter distal end portion of the body assembly into the counterbore of the new prechamber housing; and
welding the proximal end of the outer peripheral wall of the new prechamber housing to the distal end of the outer peripheral wall of the body assembly, along a new circumferential weld joint spaced axially along the outer peripheral wall of the body assembly by a distance of 2.5-3 times the width W from the original circumferential weld joint.

10. A remanufactured prechamber assembly, comprising:
a remachined body assembly;
a new prechamber housing welded to the remachined body assembly along a new circumferential weld joint;
wherein: one of a distal end portion of the remachined body assembly and a proximal end portion of the new prechamber housing includes a reduced diameter portion; and
an axial length of the reduced diameter portion is configured to be fitted in a counterbore formed at the other of the distal end portion of the remachined body assembly and the proximal end portion of the new prechamber housing; and
a new circumferential weld bead extending around and joining a proximal end of an outer peripheral wall of the new prechamber housing and a distal end of an outer peripheral wall of the remachined body assembly along the new circumferential weld joint, and the new prechamber housing abuts the remachined body assembly at a location that is radially inward of the new circumferential weld bead;
wherein a centerline of the new circumferential weld bead is spaced axially along the outer peripheral wall of the remachined body assembly toward a proximal end of the remachined body assembly from a location of a centerline of an original circumferential weld bead at an original circumferential weld joint around a distal end of the outer peripheral wall of the body assembly by a distance of 2.5-3 times a width W of the original circumferential weld bead as measured in an axial direction parallel to a central axis of the prechamber assembly; and,
wherein a heat affected zone of the original circumferential weld bead extending cirucumferential around the center axis is removed.

11. The remanufactured prechamber assembly of claim 10 , wherein the remachined body assembly includes a reduced diameter distal end portion with an outer diameter that is from 2.4 W to 4.0 W less than an outer diameter of an outer peripheral surface at the distal end portion of the remachined body assembly.

12. The remanufactured prechamber assembly of claim 10 , further including one of the counterbore or the reduced diameter portion at the proximal end portion of the new prechamber housing that is configured to form a press fit with one of the reduced diameter portion or the counterbore, respectively, at the distal end portion of the remachined body assembly.

13. The remanufactured prechamber assembly of claim 12 , wherein the one of the counterbore or the reduced diameter portion at the proximal end portion of the new prechamber housing is configured to mate along an axial length of the one of the reduced diameter portion or the counterbore, respectively, at the distal end portion of the remachined body assembly to form a cylindrical press fit interface.

14. The remanufactured prechamber assembly of claim 10 , wherein:
the distal end portion of the remachined body assembly includes the reduced diameter portion;
the proximal end portion of the new prechamber housing includes the counterbore; and
the axial length of the reduced diameter distal end portion of the remachined body assembly is 2.5 W-3.0 W longer than the axial length of the reduced diameter distal end portion of the

Assignees

• Caterpillar Inc

Inventors

• Graham Curtis J
• Graham Timothy S
• Luick Kegan J
• Bright Larry D

Classifications

• F02B19/16

  Chamber shapes or constructions not specific to sub-groups F02B19/02 - F02B19/10 · CPC title

• H01T13/08

  Mounting, fixing or sealing of sparking plugs, e.g. in combustion chamber · CPC title

• F02B19/12

  with positive ignition (engines with non-timed positive ignition, and with incandescent chambers F02B9/08) · CPC title

• F02B77/005

  Plugs · CPC title

• B23P6/02 Primary

  Pistons or cylinders · CPC title