Abstract: Provided is a disc brake including a brake caliper. The brake caliper has a first bridge part positioned on a first pin disposition part side and on which a sprue mark formed at the time of casting a caliper main body part is provided, and a second bridge part positioned on a second pin disposition part side. The brake caliper has a shape in which a moment of inertia of area of the caliper main body part on the first bridge part side is larger than a moment of inertia of area of the caliper main body part on the second bridge part side when the caliper main body part is divided by a straight line that bisects a line segment connecting a center of the first pin disposition part and a center of the second pin disposition part when viewed from an axial direction of a disc.

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 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 including: a brake pad; a piston; a cylinder bore; an annular sealing groove formed on the cylinder bore; and a rectangular piston seal fitted into the sealing groove sealing between the piston and the cylinder bore, wherein the sealing groove includes: a bottom surface portion inclined as the sealing groove expands its diameter; a lateral surface portion that extends from one end of the bottom surface portion, the one end being a side where the sealing groove has the maximum diameter; and a chamfered portion, and wherein an inclined angle of the bottom surface portion is 2 to 8 degrees, an angle between the bottom surface portion and the lateral surface portion is 82 to 89 degrees, and with the piston installed into the cylinder bore, the piston seal abuts against the bottom surface portion and the lateral surface portion of the sealing groove.

Abstract: The bottom surface of a seal groove provided in a cylinder bore has a first slant portion and a second slant portion. A transition point between the first slant portion and the second slant portion is located closer to the opening of the cylinder bore than the center in the cylinder bore axial direction of the seal groove. A gap is formed between the outer peripheral surface of a piston seal member and the bottom surface of the seal groove, and the surface pressure applied to the bottom surface of the seal groove from the piston seal member is higher at the cylinder-bottom-side end of the piston seal member than at the cylinder-opening-side end thereof. Thus, it is possible to suppress the movement of the piston toward the cylinder bore bottom due to thermal expansion of the piston seal member.

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: The bottom surface of a seal groove provided in a cylinder bore has a first slant portion and a second slant portion. A transition point between the first slant portion and the second slant portion is located closer to the opening of the cylinder bore than the center in the cylinder bore axial direction of the seal groove. A gap is formed between the outer peripheral surface of a piston seal member and the bottom surface of the seal groove, and the surface pressure applied to the bottom surface of the seal groove from the piston seal member is higher at the cylinder-bottom-side end of the piston seal member than at the cylinder-opening-side end thereof. Thus, it is possible to suppress the movement of the piston toward the cylinder bore bottom due to thermal expansion of the piston seal member.

Abstract: A disk brake including: a brake pad; a piston; a cylinder bore; an annular sealing groove formed on the cylinder bore; and a rectangular piston seal fitted into the sealing groove sealing between the piston and the cylinder bore, wherein the sealing groove includes: a bottom surface portion inclined as the sealing groove expands its diameter; a lateral surface portion that extends from one end of the bottom surface portion, the one end being a side where the sealing groove has the maximum diameter; and a chamfered portion, and wherein an inclined angle of the bottom surface portion is 2 to 8 degrees, an angle between the bottom surface portion and the lateral surface portion is 82 to 89 degrees, and with the piston installed into the cylinder bore, the piston seal abuts against the bottom surface portion and the lateral surface portion of the sealing groove.