Abstract: A bolt fastening method enabling the same effect as when reducing the coefficient of friction of a thread surface without changing the coefficient of friction of the thread surface so as to realize an increase in a bolt axial force generated when fastening the bolt and a bolt fastening device realizing the bolt fastening method are provided. The bolt fastening method of the present invention is a bolt fastening method for when using a bolt having a bolt head and a bolt shank provided with an external thread to fasten fastened members, characterized by intentionally biasing surface pressures of a thread surface and a bolt bearing surface generated when fastening the bolt by imparting a lateral load parallel to the bolt bearing surface to the bolt head and, in that state, imparting a rotational torque rotating the external thread to the bolt head so as to fasten the bolt.

Abstract: A bolt fastening method enabling the same effect as when reducing the coefficient of friction of a thread surface without changing the coefficient of friction of the thread surface so as to realize an increase in a bolt axial force generated when fastening the bolt and a bolt fastening device realizing the bolt fastening method are provided. The bolt fastening method of the present invention is a bolt fastening method for when using a bolt having a bolt head and a bolt shank provided with an external thread to fasten fastened members, characterized by intentionally biasing surface pressures of a thread surface and a bolt bearing surface generated when fastening the bolt by imparting a lateral load parallel to the bolt bearing surface to the bolt head and, in that state, imparting a rotational torque rotating the external thread to the bolt head so as to fasten the bolt.

Abstract: An exhaust double pipe used for interconnecting an exhaust manifold with a catalytic converter of an internal combustion engine, comprising an inner pipe and an outer pipe. The outer pipe comprises a first pipe and a second pipe. The outer end of the first pipe is welded to a flange together with one end of the inner pipe. The outer end of the second pipe is welded to another flange together with the other end of the inner pipe. The inner end of the first pipe is directly fitted into the inner end of the second pipe, or is indirectly connected to the inner end of the second pipe via a spacer so as to be able to slide relative to the second pipe.

Abstract: The disclosure is relative to an improved fitting structure of an exhaust manifold to a cylinder head of an integral combustion engine for an automobile, in which enough clearance is provided between each of fitting holes, formed in the exhaust manifold and a gasket allowing a bolt to pass therethrough, and the bolt to prevent the exhaust manifold from contacting the bolt even when the exhaust manifold is thermally expanded and a low frictional thermostable member is inserted into at least one of two places, between the exhaust manifold and the gasket and between the exhaust manifold and the bolt head or a nut. The expansion of the exhaust manifold is not restricted by bolts when it is thermally expanded but is slidably displaceable freely along the surface of the cylinder head, therefore, no crevices are formed between the exhaust manifold and the cylinder head.

Abstract: An exhaust double pipe used for interconnecting an exhaust manifold with a catalytic converter of an internal combustion engine, comprising an inner pipe and an outer pipe. The outer pipe comprises a first pipe and a second pipe. The outer end of the first pipe is welded to a flange together with one end of the inner pipe. The outer end of the second pipe is welded to another flange together with the other end of the inner pipe. The inner end of the first pipe is directly fitted into the inner end of the second pipe, or is indirectly connected to the inner end of the second pipe via a spacer so as to be able to slide relative to the second pipe.

Abstract: A structure for mounting an exhaust manifold of the type having a plurality of branch tubular portions and a continuous strip-like flange portion which joins the free end portions of the branch tubular portions to the body of an internal combustion engine, wherein only opposite end portions of the strip-like flange portion are positively fastened to the body of the engine.

Abstract: An exhaust double pipe used for interconnecting an exhaust manifold with a catalytic converter of an internal combustion engine, comprising an inner pipe and an outer pipe. The outer pipe comprises a first pipe and a second pipe. The outer end of the first pipe is welded to a flange together with one end of the inner pipe. The outer end of the second pipe is welded to another flange together with the other end of the inner pipe. The inner end of the first pipe is directly fitted into the inner end of the second pipe, or is indirectly connected to the inner end of the second pipe via a spacer so as to be able to slide relative to the second pipe.