Composition and principle of three-grip chuck 'Chuck' is a mechanical device used to clamp workpieces on machine tools. From the number of jaws of the chuck, it can be divided into: two-jaw chuck, three-jaw chuck, four-jaw chuck, six-jaw chuck and special chuck. In terms of power, it can be divided into: manual chuck, pneumatic chuck, hydraulic chuck, electric chuck, dynamic chuck and mechanical chuck. From the structure, it can also be divided into: hollow type and medium solid type. The three-claw chuck uses a voltaic wrench to rotate the bevel gear. The bevel gear drives the plane rectangular thread, and then drives the three claws to move centripetally. Because the pitch of the rectangular thread on the chuck surface is equal, the three claws move at the same distance, which has the effect of automatic centering. The three-jaw chuck is composed of a large bevel gear, three small bevel gears, and three claws. Three small bevel gears mesh with the large bevel gear. The back of the large bevel gear has a plane thread structure, and three claws are equally installed on the plane thread. When the small bevel gear is turned with a wrench, the large bevel gear rotates, and the Read More »

　Three-jaw chucks are mainly used to process round parts, while four-jaw chucks are used to process square, square and eccentric parts. Application occasions: The three-jaw chuck is mainly used in finishing turning, grinding, rough turning using a universal indexing head, and grinding, milling and other processing situations where invisible position accuracy is required. Four-jaw chucks are mainly used in ordinary lathes, economical CNC lathes, grinders, milling machines, drilling machines and machine tool accessories, and indexing head rotary tables. There are two types of jaws for four-jaw self-centering chucks, including integral jaws and separated jaws. The integral claw is a claw in which the base claw and the top claw are integrated. A pair of integral claws is divided into four positive claws and four reverse claws. A pair of separation claws only has four claws, and each claw is composed of a base claw and a top claw. Through the transformation of the top claw, the functions of the forward claw and the reverse claw are achieved. In addition, soft claws can be provided according to user requirements. After random assembly (grinding), high centering accuracy can be obtained to meet clamping requirements. Three-jaw chuck clamper Read More »

　When the three-claw chuck is used for a long time, the coaxiality will decrease and the bell mouth phenomenon will occur, which directly affects the processing accuracy and clamping reliability. Practice has proved that using the following method to correct it is simple, practical and effective, so you might as well give it a try. Taking the positive jaw chuck as an example, first use an external clamp to clamp a round bar of appropriate diameter, start the machine tool, and turn the outer circular part of the jaw. Then use an inner support to clamp a ring-shaped piece, start the machine tool, and turn the inner circular part and end face of the claw. Obviously, this can significantly improve the coaxiality between the machined inner circle of the claw and the machine tool spindle, eliminate the bell mouth phenomenon, obtain higher accuracy, and achieve the purpose of correction. The following points should be noted during specific applications: 1. The outer circle of the round rod and the inner circle of the ring must be processed in advance and have a certain degree of accuracy. Moreover, the inner diameter of the annular body should not be too small, otherwise the claw surface will have a deep concave arc, which will easily damage the surface of the workpiece when clamping large-diameter workpieces, so attention must be paid. 2. Because the claws and chuck body Read More »

　In addition to the insufficient oil pressure and wear of the claws described above, there are generally several other reasons why the three-claw chuck cannot clamp the workpiece tightly: 1. The stroke of the bottom claw is insufficient. Generally, the position of the workpiece we are clamping when clamping is required to be at the midpoint of the stroke of our bottom claw. 2. The cutting force may be too large, so lower the speed or cutting force appropriately. 3. Pay attention to the maintenance of the chuck and try adding grease again. 4. The bottom claw and center core of the chuck are severely worn. If this is the case, it is recommended to replace the chuck or mold the claws according to strict requirements and add cross grooves to the claws. 5. The pressure maintaining effect of the oil cylinder is poor, and the piston or seal of the oil cylinder is worn. Please handle it accordingly. 6. Check whether the pressure and hydraulic oil of the hydraulic station are normal. Sometimes the meter does not reflect it. It is generally not recommended that you increase the pressure to adjust the clamping force. Excessive clamping force will not only damage the chuck and cylinder, but also risk the chuck being damaged and the workpiece flying out and injuring people. Read More »

　The reasons for the centering error of the three-jaw chuck were analyzed. The good results achieved by using cast iron ferrules and elastic rings in actual work are explained. The adjusted and processed parts meet not only the size requirements but also the performance, thereby extending the service life of the mechanical parts. The reasons for the centering error of the three-claw chuck: 1. The manufacturing errors of the positioning parts, guide parts and tool parts on the three-claw chuck and the amount of wear during use may change the correct positional relationship between the machine tool, the tool and the workpiece, and can cause processing errors. The size of these machining errors can be determined based on the manufacturing tolerance calculations of the main parts of the fixture. For an existing set of fixtures or a set of fixtures that have been used and worn, the actual error can be measured. According to the measurement results, the centering error of the general three-jaw self-centering chuck can reach 0.1~0.15mm. 2. Analyzing the structure of the three-jaw self-centering chuck, almost all its parts Read More »

　　The most direct way to upgrade processing capabilities is to upgrade equipment, but each part of the processing still needs to cooperate with each other. For example, it already has a 5-axis DMG machine tool, which has the ability to process parts with a diameter of 840mm, a length of 500mm, and a maximum weight of 600kg. It can produce a variety of parts including circular, rectangular, and irregular geometric shapes. The traditional three-jaw chuck cannot meet the demand, and a safe, fast and flexible clamping method needs to be found to ensure the efficient operation of the new machine. Floating clamping solution The clamping methods of the following group of products are worthy of reference. For easily deformed parts and diverse combinations of clamped workpieces, through the combination of claws and components, the patented floating centering clamping can solve the centering processing problems of rectangular and geometrically irregular parts. ▲Used for centering floating clamping ▲Clamping of easily deformable parts ▲Clamping of square, round, and asymmetric parts Processing of easily deformable thin-walled parts: Thin-walled parts clamping Read More »

　1. Install the chuck onto the tie rod. Remove the soft claws and dust cover of the chuck, lock the threads with screws No. 1, 2, and 3. Place the sleeve wrench on the center hole of the chuck. Lock the tie rod nut into the tie rod. Depending on whether the oil pressure is at 4-5kgf/cm2, move the tie rod back and forth 2-3 times and lock the nut smoothly. 2. When the tie rod nut is locked on the tie rod, if it is not locked smoothly, you should recheck whether the center of the thread is tilted, etc. If it is forced to lock, it will cause accuracy errors and damage to the thread. 3. Install the chuck on the spindle. Turn the sleeve wrench until it is securely coupled to the end face of the spindle. Tighten the screws in the following order. Note: Please tighten the chuck connecting screws according to the set torque. If the locking torque is insufficient or too strong, an accident may occur. The above attached screws are the usage principle. If there are special circumstances, please use 12.9 or above (M22 or above 10.9) and have sufficient length. Read More »

　1. Install the tie rod on the rotary cylinder. Screw the tie rod into the piston thread of the rotary cylinder until it reaches the bottom of the piston. (If the position is not reached, the spiral stop lock of the piston will be damaged). 2. Install the rotary cylinder on the main shaft (rotary cylinder connecting plate), check whether the rotary cylinder deflects and whether the pipeline is normal, set the oil pressure to a low pressure state (0.4Mpa-0.5Mpa, 4-5kgf/cm2), make the piston move 2-3 times and then stop at the front end, and then turn off the power. 3. When installing or removing the chuck, it is necessary to use a sling or lifting ring to fix it. 4. Remember to remove the lifting ring or strap from the chuck after use. Read More »

With the development of society, more production fields have begun to use automation equipment as industrial productivity. The normal operation of automation equipment has an increasing impact on the overall production of enterprises. Here, we introduce the indexing chuck. The indexing chuck is a clamping tool that can rotate the workbench and plays an important role in many automation equipment. However, most of the existing indexing chucks assembled in the automation equipment on the market have the following problems: when using a grinder to process workpieces, there is no indexing chuck, and it is extremely inconvenient to coordinate the instructions with a single tilt plate for three angle adjustments; and each adjustment of the angle requires re-clamping, which makes it difficult to ensure the concentricity of the processing. In addition, there is no positioning mechanism connected to the chuck, so it is difficult to ensure the concentricity of the workpiece; the overall structure is not uniform, the operation method is complex, the positioning method is unstable, error-prone, and the versatility is weak. The chuck specifications applicable to different equipment are different, and the scope of application is insufficient. for Read More »

　　Hydraulic chuck is also called power chuck. Hydraulic chuck is mainly used in lathes, milling machines, drilling machines, machining centers, indexing plates, etc. The advantages of hydraulic chuck are high precision, large clamping force and high processing efficiency. The hydraulic chuck clamps and releases the workpiece through the push and pull action of the tie rod. The accuracy of hydraulic chuck can reach up to about 0.01mm. The hydraulic chuck consists of a pull plate, an inner ring nut, a base claw, a T-block, a plate body, and a claw. The front end of the pull rod (self-made screw threads at both ends of the pull pipe, which can be made of seamless pipe) is connected to the inner ring screw of the chuck, and the other end of the pull rod is connected to the hydraulic rotary cylinder nut of the lathe tailstock. Oil is supplied to the rotary cylinder through the hydraulic station, and the piston action of the hydraulic rotary cylinder forms a thrust force. The pulling force drives the pull rod, and the pull rod drives the inner ring nut and the stress point of the pull plate to loosen and clamp the claws. Read More »

How to correct the three-jaw chuck in hydraulic chuck? Read More »

　　A brief analysis of the new turning method using a three-claw chuck instead of a dial Abstract: A new turning method using a three-claw chuck instead of a dial can improve productivity, reduce costs, and simplify the installation of workpieces. Analyze and discuss the construction technology of the triangular claw plate. During turning, for shaft workpieces that require high coaxiality and need to be turned around, double centers are often used to clamp the workpiece and rotate with the spindle through the dial and clamp. However, this method has relatively low production efficiency, high cost, and the installation operation is more complicated. The construction technology of using a three-claw chuck instead of the dial has certain advantages compared with it. In the era of competition, enterprises must pay attention to improving production efficiency, reducing production costs, and simplifying construction processes. The turning method of using a three-jaw chuck instead of a dial is a relatively advanced turning method. 1 Types and process improvements of three-jaw chucks With the increasing demand for high-precision and high-speed mechanical processing, in order to meet the diversification and high-standard machines pursued by users, Read More »