Abstract: An annular space is formed between a circumferential wall of a wear-resistant chip and a circumferential wall of a recessed portion of a mechanical part. A resilient stopper in the form of a ring is installed in the annular space for resilient deformation between the circumferential wall of the wear-resistant chip and the circumferential wall of the recessed portion for thereby urging the wear-resistant chip and the recessed portion in opposite direction thereby fixing the wear-resistant chip to the recessed portion.

Abstract: A replenishing solution unit for color-developing a color photographic light-sensitive material is disclosed. The replenishing solution unit comprises at least (1) a replenishing solution containing a color developing agent and a sulfinic acid or a salt thereof and the pH of said replenishing solution is 2 to 6 and (2) a replenishing solution containing a replenishing solution component other than the color developing agent. The replenishing solution unit enables the preparation of a concentrated developing solution and has excellent storage stability over a long period of time without the decrease of photographic sensitivity and the increase of D.sub.min. A method for processing a color photographic light-sensitive material with the above replenishing solution unit is also disclosed.

Abstract: In a frictionally sliding structure, a metallic intermediate member is provided, which has a head and a stud. The stud is interfit into a recess provided with a tappet, while the head has a ceramic chip on which a cam is adapted to frictionally slide.

Abstract: A mechanical part has a contact surface for movement on a mating surface. The contact surface is first rough ground by using a grinding wheel of a grain size, for example, equal to or smaller than #200 and then barrel finished or buffed so as to have such a profile that is roughness spacing ranges from 5 to 100 .mu.m and more than half of its peaks are smoothly rounded.

Abstract: A tappet for an internal combustion engine comprises a tappet main body and a ceramic seat plate. The tappet main body is constituted by axially separated first and second parts which are made of different metallic materials. The first part is for installation in a hole of a cylinder block for sliding therein. The second part is for installation between a push rod and a cam. The metallic material for the second part is more wear-resistant than that of the first part. The ceramic seat plate is brazed to the second part, and the first and second parts are joined together by welding such as electron beam welding, laser beam welding, etc.

Abstract: A method of producing 1H-pyrazolo[5,1-c]-1,2,4-triazoles represented by general formula (II): ##STR1## (wherein R.sub.1, R.sub.2 and R.sub.3 each represents a hydrogen atom or a substituent group) which comprises making a compound represented by general formula (I) undergo a ring closure reaction: ##STR2## (wherein R.sub.1, R.sub.2 and R.sub.3 each represents a hydrogen atom, or a substituent group), and a method of producing a pyrazol derivative represented by general formula (I) by reacting a compound represented by general formula (III) and general formula (IV): ##STR3## wherein R.sub.1, R.sub.2 and R.sub.3 have the same meaning as in general formula (I); Y represents an acid radical; and n represents 0 to 1.

Abstract: An induction valve of a direct fuel injection diesel engine has helical flow director flanges formed on the upstream side for directing the inducted air into a vortical flow within the combustion chamber. The flow directing flanges are formed on the valve and the induction port with which the valve is associated has an extremely simple configuration. An induction passage liner is simply configured to reduce the resistance to air flow.

Abstract: A process for producing a 3-iminonitrile represented by the following general formula (I): ##STR1## wherein M represents an alkali metal, which comprises reacting acetonitrile with an alkali metal hydride in an amount of from 0.01 to 0.5 molar equivalent to acetonitrile; and a process for producing a 3-iminonitrile of the formula (II): ##STR2## which comprises mixing the compound represented by the foregoing general formula (II), which was obtained by the reaction between acetonitrile and the alkali metal hydride, with a protic solvent, are disclosed. These processes are useful for producing the desired 3-iminonitrile safely, inexpensively and in high yields.

Abstract: A camshaft structure has shaft portions made of metal and which are axially aligned with each other. Ceramic cam portions are axially sandwiched between adjacent shaft portions. A thin layer of brazing alloy is arranged between adjacent surfaces of the shaft portions and cam portions so as to integrally bond the portions together to provide a high ridigity structure.

Abstract: In a tappet structure in which a rotary movement is transformed into an axial movement by way of a cam, the tappet structure has a metallic tappet body, an inside of which has a hollow portion in a manner to have an opening at one end of the tappet body. A friction-resistant ceramic plate is integrally fixed to the open end of the tappet body by means of brazing, so that the cam can frictionally slide on the ceramic plate to move the tappet body axially.

Abstract: A mechanical part has a contact surface for movement on a mating surface. The contact surface is first rough ground by using a grinding wheel of a grain size, for example, equal to or smaller than #200 and then barrel finished or buffed so as to have such a profile that its roughness spacing ranges from 5 to 100 .mu.m and more than half of its peaks are smoothly rounded.

Abstract: A mechanical part has a contact surface for movement on a mating surface. The contact surface is first rough ground by using a grinding wheel of a grain size, for example, equal to or smaller than #200 and then barrel finished or buffed so as to have such a profile that its roughness spacing ranges from 5 to 100 .mu.m and more than half of its peaks are smoothly rounded.

Abstract: A body, like a rocker arm, is disclosed which comprises a base body fabricated of a Ni-Cr-Mo type steel which contains less than 8 wt % Cr; and a ceramic tip soldered to a given portion of the base body. The soldering is so made as to increase the hardness of the base body.

Abstract: A mechanical part has a metal main body and a ceramic tip having a joining surface at which it is joined to the metal main body. The ceramic tip has a chamferred edge at the periphery of the joining surface. The joining surface and the chamferred edge are metallized prior to joining of the joining surface to the metal main body.

Abstract: A rotary valve is rotatable about an axis and has a port extending crosswise of the axis of rotation. A drive unit drives the rotary valve to oscillate about 180.degree. in such a way that the rotary valve rotates in one direction into and out of the position of establishing communication between the valve port and a cylinder head port communicating with a combustion chamber.

Abstract: A metal-ceramic heat-insulating structure having a metallic tubular member fitted with a hollow cylindrical sintered ceramic, the inner surface of which is to be exposed to elevated temperatures. The sintered ceramic is bound to the metallic tubular member by means of a ceramic powder compacted in a gap located between the two members.

Abstract: A cylinder head has an insert assembly defining a precombuation chamber in a cylinder head. The insert assembly includes a domed insert made of ceramics and cast into a cylinder head body. A fuel injection nozzle hole and a glow plug hole are formed so as to open through the domed insert into the precombustion chamber and inclined with respect to a center axis of the precombustion chamber. The domed insert is provided at the inner surface thereof with a flat inner surface portion constituting part of a circular plane of which axis coincides with a center axis of the precombustion chamber and/or a recess constituting part of a truncated cone or a sphere of which axis coincides with the center axis of the precombustion chamber, whereby to eliminate an otherwise occurring sharp edged portion or portions of the domed insert.

Abstract: An inclined surface of a valve head extending between a valve stem and a valve seat contacting portion has an annular portion in the place intermediate between the valve steam and the valve seat contacting portion. The inclined surface is ground at the annular portion only.

Abstract: A rocker arm comprises a main body section made of ceramics and a protective member section covering the outer surface of the main body section. The protective member section is in the form of a film or layer and made of a ductile material so that upon breakage of the ceramic main body section the protective member is plastically deformed to hold the broken pieces of the ceramic main body together.

Abstract: A mechanical part comprises a sliding section and a sleeve section which are prepared separately. The sliding section is made of a wear resisting material such as ceramics and formed with a planar sliding surface at one of the sides thereof. The sliding section is further formed with a joining portion at the outer periphery thereof. The sleeve section is made of metal and formed with a joining portion at the inner periphery thereof. The joining portions of the sliding section and the sleeve section are joined by interference fit or the like, whereby to allow the sliding surface of the sleeve section to be formed into a crowned shape.