| 摘要 |
1,030,447. Assembling force fits. GENERAL MOTORS CORPORATION. Sept. 10, 1963 [Sept. 20, 1962], No. 35653/63. Heading B3U. [Also in Division F2] A method of press-fitting a pair of cylindrical members comprises applying vibratory energy to one of the members in a plane normal to the longitudinal axis of the member. An apparatus for performing the method comprises a pneumatic press having a ram 10 and a vibratory energy device 16 which applies energy to a liner 14 to be inserted into a cylinder bore 4 of an engine 6. The device 16 comprises a disc 17 threaded on a post 18 which also carries a seating member 20 having an upper conical portion 22 and a split skirt 24. Two similar vibrators 26 are mounted adjacent the periphery of the disc 17, each vibrator consisting of a housing 28, Fig. 5 (not shown), clamped to the disc 17, and having a bore 34 containing a sleeve 36 into which air can pass from an annular chamber 40, by tangential passages 42, which are inclined so as to produce in the two vibrators oppositely directed rotations of free rollers 46 which work in the bores 44 of the sleeves 36. The rollers 46 orbit in opposite directions and produce complex vibrations which can be resolved into three motions, viz., a flexural centre-suspended beam type, a flexural twist of the plate 17 and a twist about the axis of the liner. The operating frequency of the vibrators is not less than 100 c.p.s. and is preferably at the resonant frequency of the disc 17. It is important that the vibrators subject the disc 17 to torsion. In an example, a liner having a diameter of 3À7495 inches was inserted into a hole 0À0005 inch smaller, by the method of the invention, using a load of 1275 pounds as against a load of 11,000 pounds without vibration. |
