The invention discloses a tooth profile correcting method for an automobile steering device rockshaft gear sector. The method is a modification amount changing profile correcting method. Profile correcting is achieved through slotting machining, the modification amount of profile correcting is determined by three parameters including a modification start, a terminal angle and the maximal modification amount by adopting a ramp function related to gear sector rotating angles, and in the slotting machining process with a certain transmission ratio curve, a radial feed shaft retracts or feeds according to the law of motion of the ramp function to achieve profile correcting. By means of modification correcting within the range of the modification start and the terminal angle, tooth profiles of a certain section in the middle portion of the gear sector become thick, and the purpose that the back lash of an automobile steering device gear sector and rack pair is reduced or the purpose of backlash-free engaging is achieved. For the overcutting phenomenon in the profile correcting process, theoretical tooth profiles are calculated through a tooth profile normal method, and actual tooth profiles are calculated through an envelope line method. When the actual profile correcting amount does not conform to the theoretical profile correcting mount, the three parameters are adjusted, the actual profile correcting amount is calculated again until the actual profile correcting amount conforms to the theoretical profile correcting amount, and once the three parameters are adjusted, the three parameters are fixed and put on production.

Tooth profile correcting method for automobile steering device rockshaft gear sector

The invention relates to a sector shaft for a circulating ball type steering gear and a machining method thereof, a steering gear, and a vehicle. The sector shaft includes a sector shaft body; a central gear of the sector shaft body includes a pair of bosses formed on tooth profiles at two opposite sides of the central gear; the pair of bosses are symmetrical with respect to a longitudinal centralcross section of the central gear; each boss includes an intermediate section intersecting with reference circles of all the cross sections of a sector of the sector shaft, and side sections positioned on an upper side and a lower side of the intermediate section respectively and having a thickness not greater than the intermediate section. The pair of bosses are arranged on the central gear, thecirculating ball type steering gear can satisfy an ideal matching clearance characteristics of the steering sector shaft and a steering nut, the clearance is zero while an automobile runs linearly, and the position feeling of the central portion of the steering gear is improved; and after a steering wheel rotates at a certain angle, the steering gear has good steering reversal performance.

Sector shaft for circulating ball type steering gear and machining method thereof, steering gear and vehicle

The invention relates to a manufacturing method of a rocker shaft gear sector of a negative ratio redirector and a gear shaping cutter used for the same. The manufacturing method comprises the following steps of: firstly determining the angle transmission ratio of the redirector; then determining a computational formula of the special gear shape of the rocker shaft gear sector according to the transmission ratio; then drawing a curve group according to the computational formula to determine a male normal line of a large gear shape end used as a measurement foundation during machining; then inputting the transmission ratio on a gear shaping machine to generate a machining procedure; and finally utilizing the specially-made gear shaping cutter to carry out the cutting machining of the rocker shaft gear sector. The manufacturing method can be realized by using the gear shaping cutter, the rocker shaft gear sector with different gear shapes can be manufactured by adopting the manufacture method of the invention, and the negative ratio of the redirector can be realized in such a way that the rocker shaft gear sector is matched with a piston fitted with the rocker shaft gear sector.

Rongjin Shen

Papers

Manufacturing method of rocker shaft gear sector of negative ratio redirector