Abstract: In a cylinder device, a rod of which one end portion is joined to a piston in a cylinder and the other end portion protrudes from an opening portion of the cylinder includes a first member that is a hollow cylindrical member in sliding contact with a sliding contact member, and a second member that does not come into sliding contact with the sliding contact member. An outer diameter of at least a first member side end portion of the second member is smaller than an outer diameter of the first member. An inner peripheral portion of the first member is joined to an outer peripheral portion of the second member by friction weld joining.

Abstract: This cylinder device of the present aspect includes: a cylinder having a bottomed tubular shape; a seal member provided at an opening of the cylinder; and a piston rod that is provided to protrude from the opening of the cylinder and slides with respect to the seal member. A sliding surface of the piston rod has a chrome-plated layer. In the sliding surface, as characteristic evaluation parameters of a plateau structure surface described in JIS B 0671-2 and ISO 13565-2, a reduced valley depth Rvk is 0.06 ?m or more and less than a plating thickness, a reduced peak height Rpk is 0 ?m or more and 0.04 ?m or less, and a core roughness depth Rk is 0.08 ?m or more and 0.16 ?m or less.

Abstract: A method for manufacturing a rod includes a step of preparing a hollow first member and a second member formed so as to have a portion smaller in outer diameter than an outer diameter of the first member, a restraining step of placing a restraining member into abutment with an outer peripheral surface of the first member, a step of moving an inner peripheral surface of the first member and an outer peripheral surface of the second member closer to each other while rotating at least one of the first member or the second member, and a step of joining the first member and the second member by welding with the aid of friction by axially pressing in the first member and the second member by a predetermined amount after placing the inner peripheral surface of the first member and the outer peripheral surface of the second member into contact.

Abstract: In a cylinder device, a rod of which one end portion is joined to a piston in a cylinder and the other end portion protrudes from an opening portion of the cylinder includes a first member that is a hollow cylindrical member in sliding contact with a sliding contact member, and a second member that does not come into sliding contact with the sliding contact member. An outer diameter of at least a first member side end portion of the second member is smaller than an outer diameter of the first member. An inner peripheral portion of the first member is joined to an outer peripheral portion of the second member by friction weld joining.

Abstract: A caliper body of a floating-type disk brake includes a cylinder-part constituent part including a cylinder bore into which a piston pressing brake pads against a disk rotor is disposed, a bridge part extending from the cylinder-part constituent part and including a through-hole, and a claw-part constituent part formed on a leading end side of the bridge part and disposed so as to be opposite to the cylinder-part constituent part. In a method of manufacturing the caliper body of the floating-type disk brake, a mold in which sprues are provided in at least two places spaced apart from each other in a disk rotor circumferential direction on a region corresponding to the claw-part constituent part is prepared. Molten metal is poured from the sprues of the at least two places of the mold, and starts to solidify from a side of the cylinder-part constituent part.

Abstract: A caliper body of a floating-type disk brake includes a cylinder-part constituent part including a cylinder bore into which a piston pressing brake pads against a disk rotor is disposed, a bridge part extending from the cylinder-part constituent part and including a through-hole, and a claw-part constituent part formed on a leading end side of the bridge part and disposed so as to be opposite to the cylinder-part constituent part. In a method of manufacturing the caliper body of the floating-type disk brake, a mold in which sprues are provided in at least two places spaced apart from each other in a disk rotor circumferential direction on a region corresponding to the claw-part constituent part is prepared. Molten metal is poured from the sprues of the at least two places of the mold, and starts to solidify from a side of the cylinder-part constituent part.

Abstract: A disk brake includes a caliper body having a cylinder portion (25) with a cylindrical shape. The cylinder portion (25) has a bore (30) with a bottom (34) formed by integrally joining together an opening peripheral edge (98) at the bottom side of the cylinder portion (25) and a bottom cover member (92) to be fitted to the opening peripheral edge (98) through friction stir welding. The bottom cover member (92) has a disk shape and is friction-stir-welded along the outer periphery thereof. The terminating point of the friction stir welding is within the boundaries of the bottom cover member (92).

Abstract: A caliper body of a floating-type disk brake includes a cylinder having a cylinder bore into which piston pressing brake pads are disposed against a disk rotor, a bridge extending from the cylinder part including a through-hole, and a claw part formed on a leading end side of the bridge and disposed opposite to the cylinder part. The caliper body of the floating-type disk brake is made in a mold with sprues provided in at least two places spaced apart from each other in a disk rotor circumferential direction on a region corresponding to the claw part. Molten metal is poured from the sprues in at least two places of the mold, and starts to solidify from a side of the cylinder part.

Abstract: A disk brake includes a caliper body having a cylinder portion 25 with a cylindrical shape. The cylinder portion 25 has a bore 30 with a bottom 34 formed by integrally joining together an opening peripheral edge 98 at the bottom side of the cylinder portion 25 and a bottom cover member 92 to be fitted to the opening peripheral edge 98 through friction stir welding. The bottom cover member 92 has a disk shape and is friction-stir-welded along the outer periphery thereof. The terminating point of the friction stir welding is within the boundaries of the bottom cover member 92.

Abstract: A caliper body of a floating-type disk brake includes a cylinder having a cylinder bore into which piston pressing brake pads are disposed against a disk rotor, a bridge extending from the cylinder part including a through-hole, and a claw part formed on a leading end side of the bridge and disposed opposite to the cylinder part. The caliper body of the floating-type disk brake is made in a mold with sprues provided in at least two places spaced apart from each other in a disk rotor circumferential direction on a region corresponding to the claw part. Molten metal is poured from the sprues in at least two places of the mold, and starts to solidify from a side of the cylinder part.