Abstract: Flaky alumina particles including mullite in a surface layer of the flaky alumina particles. A method for producing flaky alumina particles including forming a mixture by mixing together an aluminum compound that contains elemental aluminum, a molybdenum compound that contains elemental molybdenum, and silicon or a silicon compound that contains elemental silicon, the aluminum compound being in an amount greater than or equal to 50 mass %, calculated as Al2O3, the molybdenum compound being in an amount less than or equal to 40 mass %, calculated as MoO3, the silicon or the silicon compound being in an amount of 0.5 mass % or greater and less than 10 mass %, calculated as SiO2, relative to a total mass of the flaky alumina particles taken as 100 mass %; and firing the mixture.

Abstract: A heavy duty pneumatic tire in which occurrence of uneven wear is inhibited is provided. In the tire, each shoulder land portion includes a groove wall portion forming a wall of a shoulder circumferential groove, and a cap portion located outward of the groove wall portion in an axial direction. A wear resistance index of the groove wall portion is lower than a wear resistance index of the cap portion. A ratio of a distance in the axial direction from an outer edge of the shoulder circumferential groove to a boundary between the groove wall portion and the cap portion on an outer surface of the shoulder land portion, to a width in the axial direction of the shoulder land portion, is not less than 20% and not greater than 30%.

Abstract: An electromagnetic operation part of an electromagnetic valve includes a bobbin, a fixed iron core, a movable iron core, a return spring, a magnetic cover, and a magnetic plate. A coil is would around the bobbin. The fixed iron core and the movable iron core are housed in a bobbin hole extending through the bobbin. The return spring places the movable iron core back into an initial position. The magnetic cover covers the electromagnetic operation part. The magnetic plate provides magnetic coupling between the magnetic cover and the movable iron core. The fixed iron core has a spring housing hole extending within and through the fixed iron core. The return spring is housed in the spring housing hole. A proximal end of the return spring is in contact with the magnetic cover, and a distal end of the return spring is in contact with the movable iron core.

Abstract: A compressed fluid discharge control device is provided with a diaphragm valve. When an opening/closing operation member is operated, a pilot chamber opening/closing valve opens to open a pilot chamber. As a result, pressure within a valve chamber becomes higher than that in the pilot chamber and the diaphragm valve separates from a valve seat. Then, compressed fluid previously accumulated in a holding chamber flows into a discharge passage through the valve chamber and is discharged from the discharge opening of the discharge passage.

Abstract: A heavy-duty pneumatic tire includes a section width being equal to or less than 335 mm, an aspect ratio being equal to or less than 55%, and a toroidal carcass extending between axially spaced bead portions through a tread portion and sidewall portions. The carcass includes a carcass ply which includes a main portion and a turn-up portion turned up around a bead core of each bead portion. A belt layer is disposed radially outward of the carcass in the tread portion, wherein a radially outer end of the turn-up portion is located between the main portion and the belt layer in the tread portion. A sheeted rubber layer is disposed between the main portion and the turn-up portions in each sidewall portion.

Abstract: Enlarged holes are formed at respective end portions of a valve hole housing a spool by forming an upper recessed groove and a lower recessed groove at each end portion. The respective lower recessed grooves are in communication with discharge ports. The spool includes discharge lands and discharge packing portions, which open and close discharge passages connecting an output port and the discharge ports. When the discharge land and the discharge packing portion open the discharge passage by displacing of the spool, the discharge passage and the discharge port are in communication with each other through the enlarged hole by positioning the discharge land and the discharge packing portion inside the enlarged hole.

Abstract: A compressed fluid discharge control device is provided with a diaphragm valve. When an opening/closing operation member is operated, a pilot chamber opening/closing valve opens to open a pilot chamber. As a result, pressure within a valve chamber becomes higher than that in the pilot chamber and the diaphragm valve separates from a valve seat. Then, compressed fluid previously accumulated in a holding chamber flows into a discharge passage through the valve chamber and is discharged from the discharge opening of the discharge passage.

Abstract: A pressure booster having arranged therein drive cylinders on both sides of a boosting cylinder is provided with a pair of pilot valves that are actuated when pistons of the drive cylinders abut against the moving ends thereof. A pair of actuation valves switch the supply state of a pressure fluid to pressure chambers of the drive cylinders. When the pilot valves are actuated, the pressure fluid passes through the pilot valves and is supplied to the pair of actuation valves, and the supply state of the pressure fluid is switched.

Abstract: A fluid circuit for air cylinders is provided with a switching valve, an air supply source, an exhaust port and a check valve. When the switching valve is in a first position, one cylinder chamber is connected with the air supply source and the other cylinder chamber is connected with the exhaust port. When the switching valve is in a second position, the one cylinder chamber is connected with the other cylinder chamber via the check valve, and the one cylinder chamber is connected with the exhaust port. The acoustic velocity conductance of a pipe connecting the switching valve and a cylinder port part of the one cylinder chamber is lower than the acoustic velocity conductance of the switching valve and the cylinder port part of the one cylinder chamber.

Abstract: A heavy duty pneumatic tire in which occurrence of uneven wear is inhibited is provided. In the tire, each shoulder land portion includes a groove wall portion forming a wall of a shoulder circumferential groove, and a cap portion located outward of the groove wall portion in an axial direction. A wear resistance index of the groove wall portion is lower than a wear resistance index of the cap portion. A ratio of a distance in the axial direction from an outer edge of the shoulder circumferential groove to a boundary between the groove wall portion and the cap portion on an outer surface of the shoulder land portion, to a width in the axial direction of the shoulder land portion, is not less than 20% and not greater than 30%.

Abstract: An air cylinder fluid circuit is formed by connecting a switching valve, which switches the supply and discharge of compressed air, and cylinder port parts of an air cylinder by means of pipes, wherein the acoustic velocity conductance of the pipes is smaller than the acoustic velocity conductance of the switching valve and the cylinder port parts.

Abstract: A pressure booster having arranged therein drive cylinders on both sides of a boosting cylinder is provided with a pair of pilot valves that are actuated when pistons of the drive cylinders abut against the moving ends thereof. A pair of actuation valves switch the supply state of a pressure fluid to pressure chambers of the drive cylinders. When the pilot valves are actuated, the pressure fluid passes through the pilot valves and is supplied to the pair of actuation valves, and the supply state of the pressure fluid is switched.

Abstract: A heavy-duty pneumatic tire includes a section width being equal to or less than 335 mm, an aspect ratio being equal to or less than 55%, and a toroidal carcass extending between axially spaced bead portions through a tread portion and sidewall portions. The carcass includes a carcass ply which includes a main portion and a turn-up portion turned up around a bead core of each bead portion. A belt layer is disposed radially outward of the carcass in the tread portion, wherein a radially outer end of the turn-up portion is located between the main portion and the belt layer in the tread portion. A sheeted rubber layer is disposed between the main portion and the turn-up portions in each sidewall portion.

Abstract: A pneumatic tire to be mounted on a 15-degree-taper rim comprises a pair of bead portions each with a bead core, wherein in a meridian section of the tire under a state that the tire is not mounted on the rim but the bead portions are held such that the bead width is equal to the rim width of the 15-degree-taper rim, the bead base surface of each bead portion, which is defined as extending between a bead heel and a bead toe, is substantially straight and inclined at an angle of from 22 to 26 degrees with respect to the tire axial direction, and a ratio La/Lb of the axial width La of the bead base surface to the maximum width Lb of the bead core is in a range of from 1.3 to 1.6.

Abstract: A pneumatic tire comprises a tread portion provided with blocks, each block provided with circumferentially opening V-shaped corners each defined between two corner walls intersecting each other. In a cross section including the intersecting line K of the two corner walls and a normal line drawn normally to the tread face from a radially outer end of the intersecting line K, the intersecting line K comprising an upper slanting part KU and a lower normal part KL, the upper slanting part KU extending radially inwards from the tread face to a point P1 with an inclination angle &thgr;1 with respect to said normal line, and the lower normal part KL extending radially inwardly from the point P1 in substantially parallel to the normal line. The depth D1 of the point P1 from the tread face being in a range of from 0.30 to 0.50 times the height H0 of the block.

Abstract: A pneumatic tire to be mounted on a 15-degree-taper rim, comprises a tread portion, a pair of sidewall portions, a pair of bead portions each with a bead core therein, and a carcass comprising a ply of steel cords, wherein in a meridian section of the tire under a state that the tire is not mounted on a rim but the bead portions are held such that the bead width is equal to the rim width of said 15-degree-taper rim, the bead base surface of each said bead portion, which is defined as extending between a bead heel and a bead toe, is substantially straight and inclined at an angle of from 22 to 26 degrees with respect to the tire axial direction, and a ratio La/Lb of the axial width La of the bead base surface to the maximum width Lb of the bead core is in a range of from 1.3 to 1.

Abstract: A pneumatic tire comprises a tread portion provided with blocks, each block provided with circumferentially opening V-shaped corners each defined between two corner walls intersecting each other. In a cross section including the intersecting line K of the two corner walls and a normal line drawn normally to the tread face from a radially outer end of the intersecting line K, the intersecting line K comprising an upper slanting part KU and a lower normal part KL, the upper slanting part KU extending radially inwards from the tread face to a point P1 with an inclination angle &thgr;1 with respect to said normal line, and the lower normal part KL extending radially inwardly from the point P1 in substantially parallel to the normal line. The depth D1 of the point P1 from the tread face being in a range of from 0.30 to 0.50 times the height H0 of the block.