Analysis of Typical Trapezoidal Thread Shaft Processing
Processing Procedures
Generally, the base surface is processed first, and the processing is carried out from near to far, from rough to fine, and from primary to secondary. That is, the base surface accuracy is first turned out, and then the process of rounding first, roughing second, fine first, and then finishing is carried out, and finally the surface groove and trapezoidal thread are processed.
Select the Appropriate Tr Thread End Mill
When turning a trapezoidal thread shaft, when selecting the rough turning tool, a hard metal turning tool with a main deflection angle greater than or equal to 90° should be selected. Its secondary deflection angle is relatively large and can affect the contour of the part. The selection of grooving is based on the width of the groove of the trapezoidal thread shaft. It is necessary to determine the standard of tool rigidity and use one tool to process all grooves. When selecting tools for fine-tuning and threading, choose a tool that matches the thread profile angle. For example, for a turning tool for a hard metal 50! external trapezoidal thread, the selected tooltip angle is 49.5° and the selected tool tip circle radius is 0.06-0.1mm.
The Amount of Cutting of Trapezoidal Thread Shaft
When selecting the cutting amount of trapezoidal thread, you must ensure the durability of the tool and the processing standard, and give full play to the maximum use of the tool and machine tool, which not only increases the quality of cutting, but also reduces the processing cost.
The Amount Principle for Rough Processing
The selected backing tool amount should be the largest: then according to the nature and function of the machine tool, the feed amount should be selected with the largest amount: the service life of the installed tool should be the most suitable cutting speed.
The Amount Principle for Fine Feeding
The backing tool amount should be selected according to the remaining amount after rough processing, and then according to the standard of the smoothness of the processed part, a small feed amount should be selected, and the use limit of the tool should be ensured to select the fastest cutting speed.
Calculation of Trapezoidal Thread Shaft
Trapezoidal thread shaft is generally represented by “T” in the calculation formula. In the formula, the size of the left-hand thread should be marked with “LH”. According to the international calculation rules, the tooth angle of the trapezoidal thread is 30°.
Process Analysis of Turning of Trapezoidal Thread Shaft
Because the difference in the radius value between each step of the trapezoidal thread shaft is not very large, the material selection can be No. 40 steel.
Because the two sides of the trapezoidal thread shaft must have a coaxial standard, when performing precision turning, it is necessary to use two-sided tip clamping to implement turning. And install the front tip on the front tip inside the machine tool, or use the metal front tip with a 60-degree cone angle made by yourself (pay attention to the processing of the cone surface every time you install it, and ensure that the rotation and the cone surface are on the same axis).
When using turning to process trapezoidal thread shafts, the finishing and rough turning operations should be performed separately. When rough turning the trapezoidal thread shaft, grind the quick metal to a tool tip angle of 28″ and make it convenient to cut on both sides to have a margin for fine turning. The width of the tool tip should not be greater than the width of the bottom of the tooth groove, and a large front angle should be ground, usually, eight to ten degrees in height, and a 0.2 mm margin should be reserved on each side.
When fine turning the trapezoidal thread shaft, grind the quick metal to a tool tip angle of thirty degrees, the same as the tooth angle, the width of the tool tip should be slightly smaller than the width of the bottom of the tooth groove, and the front angle is zero. And first fine turn one side of the part, just to see the light, then turn the small plate over, eliminate the gap, and then advance 0.2 mm, in order to move the fine turning trapezoidal thread cutter slightly away from the side that has been processed. Perform two more operations to turn the deeper area thoroughly and fine-turn the bottom. Fine turn the other side, and always pay attention to check whether the diameter of the trapezoidal thread shaft meets the standard requirements.
There are certain standard requirements for the tolerance of taper, so the adjustment of the angle of the small slide requires the most accurate detection. The main process: rotate the slide by half an angle and fix the nut. Add a dial gauge seat with electromagnetic attraction on the chuck surface or saddle of the machine tool, and then point the measuring pointer of the measuring gauge to the horizontal ground and touch the side of the slide; adjust the measuring gauge to zero and drag the slide so that the measuring gauge touches the side of the slide, adjust it, and then point the slide so that they are ten meters apart, and then observe whether the value of the test gauge meets the standard.
Processing Example of Trapezoidal Thread Shaft
The processing procedure of trapezoidal thread shaft:
Select the materials to be used for processing: standard size steel.
Perform rough turning:
- Use a three-jaw self-centering chuck to fix one side, and reserve 60 mm.
- Flat end face.
- Drill a hole in the middle, repair and polish, apply grinding green on the top of the binding of the harder metal, and then put it on the machine tool for research and polishing, so as to meet the requirements of the design standards of the drawing.
- When rough turning the outer circle of the trapezoidal thread shaft, reserve 0.2 mm on one side.
- When rough turning the outer circle of the 30 mm trapezoidal thread shaft, it must meet the required standard size.
- When rough turning the trapezoidal thread, reserve 0.2 mm at the bottom and both sides of the tooth profile, and pay attention to the cleaning of the top edge of the tooth profile.
Problems That are Easy to Occur When Processing Trapezoidal Thread Shafts
When processing trapezoidal thread shafts, it is necessary to use the front and rear tops and the heart-shaped clamping device clamping solution, otherwise it is not easy to meet the design standard requirements of the drawings.
When using the front and rear tops and the heart-shaped clamping device clamping solution, due to its insufficient clamping force, it can only be processed by fine turning and the processing of the trapezoidal thread shaft is the obstacle of English cutting. Therefore, the trapezoidal thread shaft parts must be rough turned first.
Since the smoothness of the center hole in the middle of the trapezoidal thread shaft is relatively large, most of the holes drilled by drilling with a center drill alone cannot be guaranteed, so the trapezoidal thread shaft parts must be studied and polished.
The base cone surface is more suitable for turning, and the quality and standard are much higher than those of processing with an electric drill.
There are no tolerance issues in other aspects, but the standard requirements for the accuracy of the size of the trapezoidal thread shaft are very high, and the rough turning and fine tuning must be carried out separately. The use of front and rear centers and heart-shaped devices for fine turning can ensure the coaxiality of each surface, which will enhance the accuracy of the processing technology of the trapezoidal thread shaft parts.
Analysis of the Wedge-cross Rolling Process for Trapezoidal Thread Shafts
The wedge-cross rolling process not only improves the processing efficiency of trapezoidal thread shafts but also saves processing materials. It has important advantages in the processing of trapezoidal thread shaft parts by virtue of the continuous partial processing method. Therefore, this method is generally used when processing trapezoidal thread shafts.
Trapezoidal thread shaft parts have a very wide range of uses in industrial production. Trapezoidal thread shafts with small radius have the purpose of connection and fixation. Trapezoidal thread shaft parts with large radius can not only be fixed and connected but also transmit power. For example, the worm shaft can be used in space axial power transmission. At present, the common processing method for trapezoidal thread shafts with large radius is turning, etc. The processing process is complicated, there are many steps, and the efficiency cannot be improved.
The use of wedge-cross rolling technology to process parts of trapezoidal thread shafts is a major progress and breakthrough in the current process processing. This process method has effectively increased the production and processing efficiency of trapezoidal thread shaft parts to a large extent, reduced production costs, saved processing materials, and promoted the development of industrial parts processing technology.
The theoretical concept of wedge-cross rolling technology for processing trapezoidal thread shaft parts has been particularly mature, but the structure of trapezoidal thread shaft parts has a certain degree of complexity, which causes some problems when using the wedge-cross rolling technology. The main problem is the universal mold designed by the rolling method of the two sides when processing the trapezoid and thread. In response to these problems, a series of studies have been conducted and a pre-blank segment mold solution has been introduced to improve the wedge-cross rolling process.
Through the analysis of the processing technology of typical trapezoidal thread shafts, we know that the two sides of the tooth profile of the trapezoidal thread shaft are smooth and deep. The precision is high, and the problem of tool piercing will occur during processing. Therefore, in order to avoid this situation, when processing the typical trapezoidal thread shaft, it is necessary to use single-sided cutting, and when cutting to a certain depth, it is necessary to avoid multi-sided cutting, so as to ensure the processing quality of the trapezoidal thread shaft.
The selection of tools for processing the trapezoidal thread shaft should be cautious. If the selected tools do not meet the standards, the processing accuracy will be insufficient, resulting in damage to the parts of the trapezoidal thread shaft. When calculating the size of the trapezoidal thread shaft, attention should also be paid to the calculation range and the use of the calculation formula. Since the application of typical trapezoidal thread shafts is very wide. Therefore, its processing technology is very critical.
