6results about How to "Eliminate thread clearance" patented technology

A die adjusting device of a press machine comprises a plunger type cylinder, a guide column, a nut lifting driving mechanism, an adjusting nut, a fixing seat and an upper cross beam. The lower ends of the guide columns are fixed to the base, and the upper ends of the guide columns penetrate through and extend out of the upper beam which is in sliding fit with the guide columns. A cylinder body of the plunger type cylinder is fixed to the fixing base, the fixing base is installed on the upper cross beam, and a plunger of the plunger type cylinder is arranged at the upper end of the guide column. The adjusting nut is sleeved outside the guide post in a penetrating manner, is in threaded connection with the guide post, is positioned above the upper cross beam and in the fixed seat, and is driven by the nut lifting driving mechanism to ascend or descend along the guide post; and the nut lifting driving mechanism is mounted on the upper cross beam. The die adjusting device of the press machine is simple in structure, simple in die adjusting and high in die adjusting precision.

The utility model relates to the technical field of stop valve discloses a kind of stop valve to prevent valve flap rotation, comprising: valve body, valve flap and valve flap cover;Valve body is opened with the valve cavity for flowing medium, valve seat is installed in valve cavity, valve cover is installed on valve body;Valve stem is installed in valve cover;Valve stem is installed in valve cavity, valve flap is connected with valve stem, valve flap is driven to adhere or away from valve seat by valve stem to cut off or communicate valve cavity;One end of valve flap structure is fixedly connected with valve flap, other end is fixedly connected with valve stem.This structure prevents the unevenness of medium flow, drives valve flap to rotate, increases the wear of valve flap cover to valve stem.When high-speed or turbulent medium passes through valve, the risk that the traditional valve flap may rotate due to uneven impact of medium, leading to wear or sealing failure is eliminated.And by prohibiting rotation, significantly reduce the mechanical wear of valve stem, valve flap cover and valve flap, prolong the life of valve.

The utility model discloses a firearm sight structure capable of adjusting the width of a notch, which is suitable for different requirements and wide in application range. Comprising a sight seat, a square groove is formed in the sight seat, an adjusting rod is arranged between the two side walls of the square groove of the sight seat, cross threads are arranged in the middle of the adjusting rod, a left sight and a right sight are arranged in the square groove of the sight seat, and leaf springs are arranged between the bottom wall of the square groove of the sight seat and the bottoms of the left sight and the right sight. The left rear sight and the right rear sight are matched with crossed threads on the adjusting rod respectively, the screwing directions of the threads on the left rear sight and the right rear sight are opposite, the two ends of the adjusting rod are both in clearance fit with the rear sight seats, and the portions, corresponding to the head of the adjusting rod, in the rear sight seats are provided with top heads and top head springs, and the top heads are perpendicular to the adjusting rod. A plurality of arc-shaped grooves are evenly formed in the cylindrical face of the head of the adjusting rod in the circumferential direction, the ejector heads are ejected into one groove under the action of the ejector head spring, and circumferential positioning of the adjusting rod is achieved.

The invention relates to the technical field of mold tables, and discloses a four-column mold table with a stroke adjusting function, the four-column mold table comprises a lower fixed plate, a top frame, a lower movable plate, a stroke adjusting assembly, an upper fixed plate and an upper movable plate, four guide columns are fixedly installed between the lower fixed plate and the top frame, the upper movable plate and the lower movable plate are sequentially connected outside the guide columns in a sliding and sleeving mode from top to bottom, and the stroke adjusting assembly is arranged between the upper fixed plate and the lower movable plate. The top of the guide column is a threaded part, a threaded tooth sleeve is rotationally connected into the upper fixing plate, the top of the guide column is sleeved with the threaded tooth sleeve in a threaded mode, a driving assembly used for driving the threaded tooth sleeve to rotate is arranged on the upper fixing plate, and a lower crank arm assembly is arranged between the lower fixing plate and the lower movable plate. According to the mold closing distance adjusting mechanism, the mold closing distance between the lower movable plate and the upper movable plate can be finely adjusted conveniently, the situation that the mold closing distance is prone to large adjusting errors is prevented, and accurate adjusting operation of the mold closing distance is more convenient.

This application relates to the field of dressing technology, and in particular to a method for ensuring the accuracy of a grinding wheel dresser. The dresser is provided with a U-shaped support seat, and a first support circular hole and a second support circular hole are respectively provided on both sides of the U-shaped support seat. During processing, the inner diameter of the first support circular hole is made smaller than the inner diameter of the second support circular hole. A steel shaft is inserted into the first support circular hole and the second support circular hole. The U-shaped support seat with the inserted steel shaft is placed vertically, and there will be a gap between the second support circular hole and the steel shaft. High-strength adhesive is filled into the gap between the steel shaft and the second support circular hole 12. After the adhesive solidifies, the steel shaft is removed. At this time, the coaxiality of the first support circular hole and the second support circular hole is relatively high. Due to the fixing effect of the adhesive and the calibration effect of the steel shaft, the coaxiality of the first support circular hole and the second support circular hole has reached a high precision. By using the steel shaft for calibration, the accuracy of the dresser can be significantly improved, enabling it to meet the requirements of high-precision processing.

The invention relates to the technical field of dressers, in particular to a precision guaranteeing method for a grinding wheel dresser, the dresser is provided with a U-shaped supporting seat, a first supporting round hole and a second supporting round hole are formed in the two sides of the U-shaped supporting seat respectively, and during machining, the inner diameter of the first supporting round hole is smaller than that of the second supporting round hole; the steel shaft is inserted into the first supporting round hole and the second supporting round hole; the U-shaped supporting seat inserted with the steel shaft is vertically placed, a gap is formed between the second supporting round hole and the steel shaft, the gap between the steel shaft and the second supporting round hole 12 is filled with high-strength glue, the steel shaft is taken out after the glue is solidified, at the moment, the coaxiality of the first supporting round hole and the second supporting round hole is high, and due to the fixing function of the glue and the calibration function of the steel shaft, the coaxiality of the steel shaft is not influenced. The coaxiality of the first supporting round hole and the second supporting round hole reaches high precision, the precision of the dresser can be remarkably improved by using the steel shaft for calibration, and the dresser can meet the requirement for high-precision machining.