A gas sensor (1) has a sensor element (21) extending in an axis direction and having, at a top end side thereof, a detecting portion (22) that detects gas; a stainless steel-made tubular metal shell (11) enclosing a radial direction periphery of the sensor element (21) and holding the sensor element (21) and having (a) a brim portion (14) protruding outwards in a radial direction and (b) a crimp portion (16) formed at a rear end side of the metal shell (11); and a sealing member (41) placed between the sensor element (21) and the metal shell (11). The crimp portion (16) is bent inwards in the radial direction and pressing down a rear end of the sealing member (41) toward the top end side. A Micro Vickers hardness of a cross section along the axis direction of the crimp portion (16) is 140 to 210 Hv.

The invention relates to the production of profiled hose nipples. The invention was based on the object of providing a method and an apparatus which allow hose nipples of the type outlined in the introduction to be produced in a simple manner such that the formation of burrs is avoided and there is no reduction in diameter. This object is achieved in that during the forming of pipe portions (1) in the apparatus (2, 7, 9) according to the invention in the region of the subsequent ring-shaped webs (4) of the nipple profile (3), the material of the pipe portion (1), at its outwardly pointing end (4), does not come into contact with the tool in the region of the parting joints (6) of the apparatus (2, 7). This can be realized by additional cavities (14) in the tool (2, 7).

The invention relates to the production of profiled hose nipples. The invention was based on the object of providing a method and an apparatus which allow hose nipples of the type outlined in the introduction to be produced in a simple manner such that the formation of burrs is avoided and there is no reduction in diameter. This object is achieved in that during the forming of pipe portions (1) in the apparatus (2, 7, 9) according to the invention in the region of the subsequent ring-shaped webs (4) of the nipple profile (3), the material of the pipe portion (1), at its outwardly pointing end (4), does not come into contact with the tool in the region of the parting joints (6) of the apparatus (2, 7). This can be realized by additional cavities (14) in the tool (2, 7).

A method is used to forge an outer joint member of a constant velocity universal joint. Track grooves of the outer and inner joint members each have an arc-shaped ball raceway center line having a curvature center that is not offset in an axial direction with respect to a joint center. The forging method includes performing ironing by press-fitting a cylindrical portion of one end of a shaft portion of a pre-processing material of the outer joint member including the shaft portion and the cylindrical portion into a die hole of a die while a punch set that is radially expandable and contractable is fitted to an inner peripheral surface of the cylindrical portion. The punch set includes punches and a punch base to guide the punches to enable advancing and retreating. Each of the punches has a pair of forming surfaces for forming the adjacent track grooves.

A method is used to forge an outer joint member of a constant velocity universal joint. Track grooves of the outer and inner joint members each have an arc-shaped ball raceway center line having a curvature center that is not offset in an axial direction with respect to a joint center. The forging method includes performing ironing by press-fitting a cylindrical portion of one end of a shaft portion of a pre-processing material of the outer joint member including the shaft portion and the cylindrical portion into a die hole of a die while a punch set that is radially expandable and contractable is fitted to an inner peripheral surface of the cylindrical portion. The punch set includes punches and a punch base to guide the punches to enable advancing and retreating. Each of the punches has a pair of forming surfaces for forming the adjacent track grooves.

A novel hollow shaft manufacturing method includes the steps of hollow cold-rolling of seamless steel pipe, cutting, annealing and surface treatment, forming by forging, precision machining, and heat treatment. The present invention uses a new process instead of the traditional process. The forging process using high-strength cold-rolled seamless steel pipes has fewer steps than using bar stock: saving three forging passes, one annealing pass and one surface treatment pass, hence saving about ½ in time and cost, shortening the cycle, reducing costs, reducing energy consumption and reducing the three wastes, increasing the stock utilization rate to about 68%, and reducing the inter-process cost calculated by weight. For the same products, using this process can shorten the production cycle.

A novel hollow shaft manufacturing method includes the steps of hollow cold-rolling of seamless steel pipe, cutting, annealing and surface treatment, forming by forging, precision machining, and heat treatment. The present invention uses a new process instead of the traditional process. The forging process using high-strength cold-rolled seamless steel pipes has fewer steps than using bar stock: saving three forging passes, one annealing pass and one surface treatment pass, hence saving about ½ in time and cost, shortening the cycle, reducing costs, reducing energy consumption and reducing the three wastes, increasing the stock utilization rate to about 68%, and reducing the inter-process cost calculated by weight. For the same products, using this process can shorten the production cycle.

A method of manufacturing a rotating bearing unit includes to cause one end surface in the axial direction of the forming punch (46), formed by combining a plurality of punch elements (46, 46) divided in the circumferential direction, which are displaceable in the axial direction and which are not displaceable in the circumferential direction, and having a processing teeth (44, 44) at one end surface in the axial direction, to face the other end surface of the caulking section (20) in the axial direction. In this state, rolls (30a) are rotated about the central axis (α) of the hub main body (8) while pressing the other end surface of the forming punch (46) in the axial direction with a pressing surface (43) of the roll (30a) having a central axis (β) that is inclined with respect to the central axis (α) of the hub main body (8).

A method of manufacturing a rotating bearing unit includes to cause one end surface in the axial direction of the forming punch (46), formed by combining a plurality of punch elements (46, 46) divided in the circumferential direction, which are displaceable in the axial direction and which are not displaceable in the circumferential direction, and having a processing teeth (44, 44) at one end surface in the axial direction, to face the other end surface of the caulking section (20) in the axial direction. In this state, rolls (30a) are rotated about the central axis (α) of the hub main body (8) while pressing the other end surface of the forming punch (46) in the axial direction with a pressing surface (43) of the roll (30a) having a central axis (β) that is inclined with respect to the central axis (α) of the hub main body (8).

A forging apparatus includes an ironing mechanism and a phase alignment mechanism. The ironing mechanism includes: a punch set, which is fitted into a cylindrical portion of a pre-processing material to be formed into the outer joint member, and is radially expandable and contractible, the cylindrical portion having grooves formed in an inner peripheral surface thereof; and a die having a hole into which the cylindrical portion is press-fitted. The phase alignment mechanism is configured to align phases of the grooves in the inner peripheral surface of the pre-processing material and phases of track groove portion forming surfaces of the punch set with each other before the pre-processing material is fitted to the punch set.