Abstract: This invention relates to a reinforcement member to be mounted internally in the doors of an automobile, and more particularly to the member comprising two parallel flat members and one or two corrugated members which connect said two parallel members in such a manner as to position the ridges of folds thereof perpendicular to the surfaces of the plate members. The reinforcement member is mounted internally in car doors. When the car receives an impact from the side of the door, the corrugated surfaces of the member can distribute the impact evenly by deforming themselves into a fan-like shape to thereby prevent the door from being abruptly folded at one point.

Abstract: A method for forming projections on the periphery of a pipe in order to provide branch pipes, such as a manifold for automobiles, is characterized in that the branch pipes are formed by a bulging process to have a predetermined thickness without thinning. A first embodiment includes the step of indenting a pipe member by press work or the like, at locations close to the position of a projection which is to be formed, in a preliminary deforming process. The deformed pipe member is then placed in a bulge mold having a recess or space, with the pipe member being positioned so that the indentations in the pipe member lie adjacent the recess in the bulge mold. Pressurized fluid is then introduced into the interior of the pipe member to bulge the wall of the pipe member into the recess in the bulge mold. A second embodiment employs a bulge mold having fixed recesses or spaces and variable recesses or spaces for forming a plurality of projections.

Abstract: A method of securing a tubular member within an annular cam member for the manufacture of a cam shaft is provided, including the steps of forming a cam member from sintered materials with at least two axially extending grooves being provided in the inner surface of the cam member adjacent the portion of the cam member having the greatest thickness such that a radially projecting ridge is defined between adjacent grooves, fitting the tubular member into the cam member, supplying a working fluid to the interior of the tubular member and applying pressure to the fluid so as to expand the tubular member while maintaining substantially the same wall thickness within the cam member until the ridge bites into the outer surface of the expanding tubular member and becomes tightly engaged therewith. The pressure applied to expand the tubular member is less than that required to fully expand the tubular member along the inner surface of the cam member.

Abstract: A structure and a method of manufacture of a manifold which is to be mounted either on the intake side or on the exhaust side of an internal combustion engine, which is formed by projecting branch pipes from one side of a pipe member in the form of straight pipes. The manifold is further provided with grooves for gas leakage prevention and for rotation prevention at the connection between branch pipes and flanges caulked to the free ends thereof.

Abstract: A method for forming branch pipes on the periphery of a pipe, such as a manifold for automobiles, is characterized in that the branch pipes are formed by a bulging process to have a predetermined thickness without thinning. A first embodiment includes the step of indenting a pipe member by press work or the like, at locations close to the position of a projection, in a preliminary deforming process. A second embodiment employs a bulge mold having fixed spaces and variable spaces for forming a plurality of projections. The second embodiment includes the step of bulging the pipe material into the fixed spaces while the variable spaces are occupied by detachable members, and the step of removing the detachable members from the mold and then bulging the pipe member again.

Abstract: A manifold which is mounted either on the intake side or on the exhaust side of an internal combustion engine. A main body of a manifold is divided into an end manifold, at least one intermediate manifold and a base manifold. Branch pipes are formed by a bulging process to project upright branch pipes on a side of each manifold, and manifolds are connected on ends with gaskets interposed therebetween so that the bending moment caused by the expansion of metal members due to hot exhaust gases may be absorbed instead of being concentrated on the roots of the manifold to enhance the durability of the manifold.

Abstract: A method and an apparatus for manufacturing cam shafts in which cam members are held in respective rotatable axially aligned rings by holding members connected within the rotatable rings so that a pipe member cam be inserted through respective aligned holes of the cam members. The rings are individually rotatable so as to rotate the cam members by respetive predetermined angles. After a pipe member is inserted in the holes of the individually rotated cam members, a bulging process device seals respective opposite ends of the pipe member and forces a pressurized fluid into the pipe so as to bulge the pipe to fix the pipe in the respective holes, thereby to form the cam shaft.

Abstract: A tubular transmission shaft for use as a drive shaft which transmits rotation from an engine to an axle of driving wheels of an automobile, including a tubular member having a smaller diameter at the middle portion thereof and larger diameter at both ends thereof and solid shaft members which are inserted and pressure tightened in both ends of the tubular member.

Abstract: A pipe material is tightly clamped into a first pair of split forming dies to form a first formed tubular body which comprises a cylindrical wall part and a flat wall part, and then the first formed body is clamped tightly into a second pair of split forming dies, the interior of which is formed to be complementary to a toothed rack to be produced on the flat wall part. A mandrel is then forcefully inserted, either with or without vibration, into the bore of the first formed part while contained within the second forming dies, so that the teeth of a rack are formed on the flat wall of the first formed part by plastic deformation. A rack thus produced from a pipe material is light in weight and inexpensive, while functionally equivalent to a rack conventionally produced by machining from a round bar.