Caulking method for preventing piston of hydraulic/pneumatic cylinder from being loosened

Patent metadata

Field	Value
Publication number	US-9522445-B2
Application number	US-201214430090-A
Country	US
Kind code	B2
Filing date	Sep 24, 2012
Priority date	Sep 24, 2012
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

A caulking method for preventing a piston from being loosened in a hydraulic or pneumatic cylinder. The method includes forming a screw hole and a mutual screw engagement portion of a cylinder rod and a piston, and fasteningly engaging a set screw with the screw hole. The method also includes pressing a remaining space portion of the screw hole in an engagement direction of the set screw using a press mechanism after fasteningly engaging the set screw with the screw hole to change a pitch of a screw thread of an inlet portion of the screw hole.

First claim

The invention claimed is:

1. A caulking method for preventing a piston from being loosened in a hydraulic or pneumatic cylinder including a tube, a cylinder rod that linearly reciprocates in the tube, the piston fastened to a screw portion of the cylinder rod, and a set screw that prevents the piston from being loosened from the cylinder rod, the method comprising the steps of:
forming a screw hole in a mutual screw engagement portion of the cylinder rod and the piston and fasteningly engaging the set screw with the screw hole; and
pressing a remaining space portion of the screw hole in an engagement direction of the set screw using a press mechanism after fasteningly engaging the set screw with the screw hole to change a pitch of a screw thread of an inlet portion of the screw hole;
wherein the press mechanism includes:
a hammer; and
a press tool detachably mounted on the hammer, the press tool including a caulking guide portion coupled to a wrench hole of the set screw to secure a center position of caulking around the set screw and the screw hole during the caulking, and a stopper formed so as to extend from an inner end of the caulking guide portion to adjust a depth of the remaining space portion during the caulking.

2. The caulking method according to claim 1 , wherein a pitch of a screw thread of the pressed remaining space portion is modified to be equal to at least ⅓ of the pitch of the screw thread of the screw hole.

3. The caulking method according to claim 1 , wherein the hammer is any one of an impact hammer, a vibrator, and a punching device.

Assignees

• Volvo Constr Equip Ab

Inventors

• Chung Yun-Hyun
• Song Ki-Cheon

Classifications

• Y10T29/49256

  with assembly or composite article making · CPC title

• F16J1/12 Primary

  with piston-rods, e.g. rigid connections · CPC title

• B23P15/10 Primary

  pistons · CPC title

• F16B39/02

  in which the locking takes place after screwing down (F16B39/01 takes precedence; split-pins, circlips, or the like for preventing relative axial movement only F16B21/10; fastening nuts by welding or riveting F16B37/06) · CPC title

• F16J10/00

  Engine or like cylinders (pressure vessels in general F16J12/00; cylinders for engines or other apparatus of particular kinds, see the appropriate subclasses, e.g. for combustion engines F02F); Features of hollow, e.g. cylindrical, bodies in general · CPC title