Abstract: A valve spring device is provided with a first coil spring and a second coil spring combined in series with each other. The inside diameter (coil inside diameter) of the second coil spring is greater than the outside diameter (coil outside diameter) of the first coil spring. A part of the first coil spring including an end portion along an axis is inserted into the second coil spring, thereby forming a combined spring. The end portion of the first coil spring and an end portion of the second coil spring are connected to each other by a connecting member. The first and second coil springs are compressed along the axis as they are located in series between a cylinder head and a retainer. A shaft of a valve is passed within the coil springs.

Abstract: A spring retainer is made from an iron-based material to improve the strength and abrasion resistance of the spring retainer and reduce the thickness and weight thereof. The spring retainer includes a retainer body having a tapered support hole to be supported with a valve stem and a flange-like spring seat circumferentially formed on a periphery at a first side of the retainer body to receive and support a valve spring. The retainer body and spring seat are integrally formed from resilient steel with grain flows continuously formed from the retainer body to the spring seat.

Abstract: A port is formed in a cylinder head of an engine. The port is opened and closed by a valve. A valve spring device is provided with a first spring and a second spring. The second spring is contained in a housing and held by a stopper in a manner such that it is compressed along an axis or subjected to a preload. The preload of the second spring is larger than an installation load of the first spring. An axial load acts on the springs. The valve spring device has load-deflection characteristics such that only the first spring deforms axially when the axial load is not larger than a predetermined value and that both the first and second springs deform axially when the axial is load exceeds the predetermined value.

Abstract: A steel wire has tempered martensite, comprises, as essential components, by mass, C: 0.53 to 0.68%; Si: 1.2 to 2.5%; Mn: 0.2 to 1.5%; Cr: 1.4 to 2.5%; Al: 0.05% or less; further comprises, as a selective component, Ni: 0.4% or less; V: 0.4% or less; Mo: 0.05 to 0.5%; or Nb: 0.05 to 0.5%; and further comprises remainder essentially consisting of Fe and inevitable impurities, wherein the grain size number of prior austenite is 11.0 or larger, and the proof stress ratio (?0.2/?B), namely, a ratio of 0.2% proof stress (?0.2) to tensile strength (?B) is 0.85 or lower. Satisfying the above requirements makes it possible to produce a steel wire for high-strength spring excellent both in workability (cold workability), and in sag resistance and fatigue properties.

Abstract: A spring retainer can reduce the set height and mass of a coil spring. The spring retainer has a retainer body attached to a stem end of a valve and a circumferential plate-like spring part having an inner circumferential part supported by the retainer body and resiliently supporting an end of the valve spring. A spring constant of the plate-like spring part is made higher than a spring constant of the valve spring, so that the plate-like spring part deflects after the valve spring is compressed, to provide a two-step load characteristic and reduce the set height, compressed height, and mass of the valve spring. It can also reduce the height and mass of the spring retainer. A spring system formed by combining the spring retainer and valve spring with each other will be compact and lightweight.

Abstract: A spring retainer is made from an iron-based material to improve the strength and abrasion resistance of the spring retainer and reduce the thickness and weight thereof. The spring retainer includes a retainer body having a tapered support hole to be supported with a valve stem and a flange-like spring seat circumferentially formed on a periphery at a first side of the retainer body to receive and support a valve spring. The retainer body and spring seat are integrally formed from resilient steel with grain flows continuously formed from the retainer body to the spring seat.

Abstract: An electrical contact member and a contact probe that are durable and economical are provided. For this purpose, an outer peripheral portion, which has a symmetrical shape with respect to a central axis in a longitudinal direction and has a hollow portion, and a core portion, which has an approximate bar shape extending in the longitudinal direction and filling the hollow portion, are included. One of the outer peripheral portion and the core portion is made of a noble metal alloy, and the other is made of a conductive material other than the noble metal alloy. The one of the outer peripheral portion and the core portion, which is made of the noble metal alloy, projects further than the other at one end portion in the longitudinal direction.

Abstract: A cylindrical core portion, at least a part of which is made of a noble metal alloy and which has a diameter larger than a maximum diameter of a shape obtained by lathe machining, and a hollow-cylindrical peripheral portion, which is made of a material different from the material of the core portion, are included. The core portion is arranged in a hollow portion of the peripheral portion with no space. The material applied to the peripheral portion is a free-cutting material selected from a group of, for example, free-cutting brass, free-cutting phosphor bronze, free cutting nickel silver, and free-cutting beryllium copper. The noble metal alloy applied to the core portion is, for example, alloy mainly consisting of silver, palladium, gold, platinum, zinc, copper, iron, and nickel, alloy mainly consisting of palladium, silver, and copper, or alloy mainly consisting of silver, platinum, zinc, gold, and copper.

Abstract: A coil spring reduces Hertzian stress on a first turn and bending stress on a coil end. A coil end 11 is shifted in a diametral outer or inner direction of a coil spring relative to the first turn 13, to form a vertical gap between the coil end 11 and the first turn 13 in a free state without load on the coil spring. Due to the gap, the coil spring including the coil end 11 and first turn 13 can be entirely processed by shot peening as well as the remaining portion. The first turn 13 receives a combination of torsional stress and Hertzian stress (contact stress). Since the coil end 11 that receives high Hertzian stress is shifted in a diametral outer or inner direction of the coil spring relative to the first turn 13, a contact point on the first turn 13 is shifted in the diametral outer or inner direction to reduce the torsional stress on the first turn 13.

Abstract: A valve spring device is provided with a first coil spring and a second coil spring combined in series with each other. The inside diameter (coil inside diameter) of the second coil spring is greater than the outside diameter (coil outside diameter) of the first coil spring. A part of the first coil spring including an end portion along an axis is inserted into the second coil spring, thereby forming a combined spring. The end portion of the first coil spring and an end portion of the second coil spring are connected to each other by a connecting member. The first and second coil springs are compressed along the axis as they are located in series between a cylinder head and a retainer. A shaft of a valve is passed within the coil springs.

Abstract: Provided is a high-strength stainless steel spring exhibiting a good workability and having a high load characteristic. Thus, the high-strength stainless steel spring of the invention has an chemical component containing 0.04 to 0.08% by mass of C, 0.15 to 0.22% by mass of N, 0.3 to 2.0% by mass of Si, 0.5 to 3.0% by mass of Mn, 16 to 20% by mass of Cr, 8.0 to 10.5% by mass of Ni, 0.5 to 3.0% by mass of Mo, and the balance of Fe and inevitable impurities, and when the average diameter of the coil is represented by D and further the diameter of the steel wire is represented by d in the case that cross sections of the stainless steel wire are in a complete round form or the value obtained by subtracting the average coil diameter from the outer diameter of the coil is represented by d? in the case that the cross sections of the stainless steel wire are in a form other than the complete round form, the spring has a spring index D/d or D/d? of 2 to 6.

Abstract: There are provided: a seamless steel pipe formed from a cylindrical steel material billet through a hot isostatic extrusion step, wherein a depth of a contiguous flaw formed on an inner periphery surface and an outer periphery surface of the steel pipe is 50 ?m or less; a hollow spring obtained by forming a hollow body in a shape of a coil or a bar or a bar with curved part from the seamless steel pipe made of spring steel and applying a surface treatment to the hollow body so that the hollow body has compressive residual stress; and a method for producing seamless steel pipe including: a billet molding step; a first heating step; a hot isostatic extrusion step; a second heating step; an extension step; a third heating step; and a pickling step.

Abstract: A port is formed in a cylinder head of an engine. The port is opened and closed by a valve. A valve spring device is provided with a first spring and a second spring. The second spring is contained in a housing and held by a stopper in a manner such that it is compressed along an axis or subjected to a preload. The preload of the second spring is larger than an installation load of the first spring. An axial load acts on the springs. The valve spring device has load-deflection characteristics such that only the first spring deforms axially when the axial load is not larger than a predetermined value and that both the first and second springs deform axially when the axial is load exceeds the predetermined value.

Abstract: A spring retainer can reduce the set height and mass of a coil spring. The spring retainer has a retainer body attached to a stem end of a valve and a circumferential plate-like spring part having an inner circumferential part supported by the retainer body and resiliently supporting an end of the valve spring. A spring constant of the plate-like spring part is made higher than a spring constant of the valve spring, so that the plate-like spring part deflects after the valve spring is compressed, to provide a two-step load characteristic and reduce the set height, compressed height, and mass of the valve spring. It can also reduce the height and mass of the spring retainer. A spring system formed by combining the spring retainer and valve spring with each other will be compact and lightweight.

Abstract: A coil spring reduces Hertzian stress on a first turn and bending stress on a coil end. A coil end 11 is shifted in a diametral outer or inner direction of a coil spring relative to the first turn 13, to form a vertical gap between the coil end 11 and the first turn 13 in a free state without load on the coil spring. Due to the gap, the coil spring including the coil end 11 and first turn 13 can be entirely processed by shot peening as well as the remaining portion. The first turn 13 receives a combination of torsional stress and Hertzian stress (contact stress). Since the coil end 11 that receives high Hertzian stress is shifted in a diametral outer or inner direction of the coil spring relative to the first turn 13, a contact point on the first turn 13 is shifted in the diametral outer or inner direction to reduce the torsional stress on the first turn 13.

Abstract: Provided is a high-strength stainless steel spring exhibiting a good workability and having a high load characteristic. Thus, the high-strength stainless steel spring of the invention has an chemical component containing 0.04 to 0.08% by mass of C, 0.15 to 0.22% by mass of N, 0.3 to 2.0% by mass of Si, 0.5 to 3.0% by mass of Mn, 16 to 20% by mass of Cr, 8.0 to 10.5% by mass of Ni, 0.5 to 3.0% by mass of Mo, and the balance of Fe and inevitable impurities, and when the average diameter of the coil is represented by D and further the diameter of the steel wire is represented by d in the case that cross sections of the stainless steel wire are in a complete round form or the value obtained by subtracting the average coil diameter from the outer diameter of the coil is represented by d? in the case that the cross sections of the stainless steel wire are in a form other than the complete round form, the spring has a spring index D/d or D/d? of 2 to 6.

Abstract: A bellows unit and a compression coil spring are located in series with each other between a first member and a second member. The bellows unit has an inner bellows, an outer bellows, and first and second end members. A sealed space is defined in the bellows unit. A compressed gas is sealed in the sealed space. The bellows unit is caused to extend and contract in the direction of an axis by the compressed gas. The sealed space contains an uncompressible liquid that can exchange heat with the gas. The liquid is an example of a heat exchange material.

Abstract: A bellows unit and a compression coil spring are located in series with each other between a first member and a second member. The bellows unit has an inner bellows, an outer bellows, and first and second end members. A sealed space is defined in the bellows unit. A compressed gas is sealed in the sealed space. The bellows unit is caused to extend and contract in the direction of an axis by the compressed gas. The sealed space contains an uncompressible liquid that can exchange heat with the gas. The liquid is an example of a heat exchange material.

Abstract: A steel wire has tempered martensite, comprises, as essential components, by mass, C: 0.53 to 0.68%; Si: 1.2 to 2.5%; Mn: 0.2 to 1.5%; Cr: 1.4 to 2.5%; Al: 0.05% or less; further comprises, as a selective component, Ni: 0.4% or less; V: 0.4% or less; Mo: 0.05 to 0.5%; or Nb: 0.05 to 0.5%; and further comprises remainder essentially consisting of Fe and inevitable impurities, wherein the grain size number of prior austenite is 11.0 or larger, and the proof stress ratio (?0.2/?B), namely, a ratio of 0.2% proof stress (?0.2) to tensile strength (?B) is 0.85 or lower. Satisfying the above requirements makes it possible to produce a steel wire for high-strength spring excellent both in workability (cold workability), and in sag resistance and fatigue properties.

Abstract: Disclosed is a steel wire rod for hard-drawn springs capable of exhibiting fatigue strength and sag resistance equivalent to or higher than springs made of an oil-tempered wire. The steel wire rod contains carbon in a range from 0.5 to less than 0.7 mass %, silicon in a range from 1.4 to 2.5 mass %, manganese in a range from 0.5 to 1.5 mass %, chromium in a range from 0.05 to 2.0 mass %, and vanadium in a range from 0.05 to 0.40 mass %, and has an area ratio Rp with respect to pearlite which satisfies the mathematical expression (1): Rp(area %)?55×[C]+61??(1) where [C] denotes the content (mass %) of carbon.