TPR Co., Ltd.

A device according to the present disclosure is a workpiece retaining device 10 that retains a retained portion 110 of an axial-directional end portion of a workpiece 100 that is cylindrical. The workpiece retaining device 10 includes a core member 32 that is round and that comes into contact an inner perimeter face of the retained portion 110 of the workpiece 100 , a pressing member 33 that presses an outer perimeter face of the retained portion 110 of the workpiece 100 to an inner side in a radial direction, and an aligning member 44 that, upon a pressing force from the pressing member 33 acting thereupon, allows the core member 32 to move in the radial direction, in accordance with a magnitude and a direction of the pressing force.

A compression ring to be used in a spark-ignition engine using hydrogen gas fuel and to be fitted to a piston ring groove of a piston installed in a cylinder, wherein T≤10 is satisfied, when an abrasion resistance test is performed with a reciprocating friction tester in a predetermined condition in order to evaluate an outer peripheral sliding surface of the compression ring, TW1 (μm) is defined as an amount of abrasion of the outer peripheral sliding surface in the test with dropping of 1 mL/hour of a bearing oil and 0.5 mL/hour of distilled water, TO1 (μm) is defined as an amount of abrasion of the outer peripheral sliding surface in the test with dropping of only 1 mL/hour of the bearing oil, and T (μm)=TW1−TO1 is defined.

In order to enable improvement with respect to recycling performance, achieve further reduction in weight, and improve environmental performance, a cylinder liner ( 30 ) according to the present disclosure has a structure in which, out of an inner face ( 21 i ) of a cylinder ( 21 ) in a reciprocating engine, the cylinder liner is provided in only a partial region over which a piston ring ( 50 ) fit onto a piston ( 40 ) that performs reciprocal motion in the cylinder ( 21 ) slides, and a liner entire length L along an axial direction of the cylinder ( 21 ) is smaller than an inner diameter B of the cylinder, and recessed and protruding forms are formed on one lower end portion ( 30 d ) that is an end portion toward a bottom dead center side of the piston ring ( 50 ) in the axial direction.

A cylinder includes grooving in the inner peripheral surface of the cylinder. In the cylinder, the grooving includes a honed groove and recessed grooves of which the groove widths and groove depths are more than those of the honed groove, the honed groove and the recessed grooves extend in the circumferential direction of the cylinder and include an inclination angle with respect to a direction perpendicular to the axis direction of the cylinder, and a length of 4 mm in which four or more of the recessed grooves exist in the axis direction of the cylinder in a region in which an oil ring slides in a case in which a crank angle is 50° or more and 140° or less can be selected on the inner peripheral surface of the cylinder.

A retaining unit that retains a stack body in which piston rings are stacked in an axial direction, a cutting-out unit that delivers a piston ring at the tip end of the stack body from the stack body, and a detecting unit that detects a boundary between the piston rings that are adjacent to each other in the stack body are included, and the cutting-out unit includes a moving unit that moves a pushing-out unit and a restricting unit, and after inserting the pushing-out unit and the restricting unit into a dividing portion that is a boundary between the piston ring at the tip end and a piston ring that is adjacent to the piston ring at the tip end in the stack body, in a state in which movement of the piston ring that is adjacent to the piston ring at the tip end in a delivering direction in which the piston ring at the tip end is delivered is restricted by the restricting unit, the moving unit moves the pushing-out unit in the delivering direction, so that the piston ring at the tip end is separated from the stack body, and the piston ring at the tip end is delivered along the retaining unit.

The present invention provides a stylus to be provided at the tip of a measuring probe, wherein the stylus includes: a stylus tip whose outer peripheral surface is brought into contact with an object to be measured; and a stylus shaft whose one end is connected to the stylus tip; wherein the stylus tip has a hard coating on the outer periphery thereof, and wherein, when a protrusion of the hard coating extending locally from the outer peripheral surface and having a height of 1 μm or more is defined as a coating protrusion, a 0.10 mm×0.10 mm region of the outer peripheral surface of the stylus tip in which region the number of the coating protrusions is 5 or less, can be selected.

A drip prevention device for a pressurized pouring furnace according to the present disclosure is a device 10 that prevents dripping of molten metal from a molten metal outlet of the pressurized pouring furnace The drip prevention device 10 includes: a stopper 20 that brings a lower end thereof into contact with the outlet so as to block the outlet, and is provided so as to be able to rotate about a central axis 20 C of the stopper with no rotation angle limitation and move vertically above the outlet; a rotation motor 30 that rotates the stopper 20 ; a drip detection device 60 that detects dripping of molten metal from the outlet in a case where the dripping occurs; and a control device 70 that, in a case where a drip detection signal is received from the drip detection device 60 , drives the rotation motor 30 to cause the stopper 20 to perform a predetermined rotation operation.

Provided is a piston ring that is used in an internal combustion engine that uses a hydrogen gas fuel. In the piston ring, the piston ring satisfies 0.75≤FPS in a case in which: the transverse rupture index of the piston ring in a case in which a transverse test is conducted under a predetermined condition is taken as FP1; the post-corrosion transverse rupture index of the piston ring in a case in which the transverse test is conducted after a corrosion test is conducted in which the piston ring is immersed in a 1% aqueous nitric acid solution for 30 minutes is taken as FP2; and the transverse rupture strength maintenance rate FPS of the piston ring is defined as FPS=FP2/FP1.

A casting system ( 10 ) includes a plurality of mold tables ( 41 and 42 ), molten metal pouring trucks ( 21 and 22 ), and a molten metal supply furnace ( 30 ). The mold tables are each provided with centrifugal casting molds ( 81 to 84 and 91 to 94 ). Each molten metal pouring truck can move to the position of each mold table and pour molten metal into the molds installed on the mold table. The molten metal supply furnace supplies molten metal to the molten metal pouring trucks.

A cylinder includes grooving in the inner peripheral surface of the cylinder. In the cylinder, the grooving includes a honed groove and recessed grooves of which the groove widths and groove depths are more than those of the honed groove, the honed groove and the recessed grooves extend in the circumferential direction of the cylinder and include an inclination angle with respect to a direction perpendicular to the axis direction of the cylinder, and a length of 4 mm in which four or more of the recessed grooves exist in the axis direction of the cylinder in a region in which an oil ring slides in a case in which a crank angle is 50° or more and 140° or less can be selected on the inner peripheral surface of the cylinder.