Introduction to the standard of taper shank for common tools of CNC tools

With the extensive use of CNC metal cutting machine tools, the amount of CNC tooling used is also increasing. Since China has introduced a large number of CNC machine tools from different countries for many years, and the tool taper shank standards used by these machine tools are not the same, this brings some difficulties to the users (especially new users who are just in contact with CNC gold cutting machine tools). And the problem. This article makes a brief introduction based on some relevant standards collected by the author, and hopes to help readers to understand and master the standard of taper shank for CNC tool.

At present, the most used CNC milling and boring and milling centers are still 7:24 tool taper shanks. However, the use of 1:10 hollow short taper shank is increasing on high-speed machine tools. For turning centers and turning centers, there are more 1:10 short taper shanks (the CZG cylindrical shank tooling system used in turning centers is beyond the scope of this article).

The 7:24 tool taper shank standard commonly used in automatic tool changers mainly includes: Chinese national standard GB 10944-89 "7:24 taper tool handle 40, 45 and 50 taper shank for automatic tool change machine"; international standard ISO 7388 /1:1983 (tool taper shank 40, 45 and 50) and ISO 7388/3:1986 (tool taper shank No. 30); German standard DIN 69871-1:1995 (30, 40, 45, 50 and 60) Tool taper shank) and DIN 69871-2 (tool taper shanks 40, 45, 50, 55 and 60); current Japanese standards are JIS B 6339:1998 (30, 35, 40, 45, 50, 55 and 60) No. tool taper shank), used to replace the Japanese Work Machinery Industry Association standard MAS-403: 1975 (40, 45, 50 and 60 tool taper shank); the current US standard is AMSE B5.50-1994 (30, 40, 45 , 50 and 60 tool taper shanks, used to replace the ANSI/AMSE B5.50-1985 standard.

Common standards for 7:24 tool taper shanks for manual tool change are National Standard GB 3837.3-83 and International Standard ISO 297-82, and Machinery Industry Standard JB 3381.1-83.

The 1:10 hollow tool taper shank currently has the national standard GB 19449.1-2004 "Hollow cone interface with flange contact surface Part 1: Handle - Dimensions". It is equivalent to the content of the international standard ISO 12164-1:2001. The original German standard DIN 69893-1:1996 has been replaced by the new standard DIN 69873-1:2003, and the new German standard is equivalent to the international standard ISO 12164-1:2001. The 1:10 tool taper shanks of other common structures are basically enterprise-standard and monopolistic, such as the KM series of Kennametal, the Capto series of Sweden Sandvik, and the NOVEX series of Walter of Germany.

The Chinese national standard GB 10944-89 for 7:24 tool taper shank for automatic tool changer is based on the international standard ISO 7388/1:1983, except for the rounding of individual project data (such as the bottom thread bottom hole depth). 13) The data is identical except that the data is not specified (such as the bottom of the keyway on the flange). The international standard ISO 7388/1:1983 is also based on the A-type tool taper shank of the German standard DIN 69871-1, so the three standards have the same external dimensions. In China, the tool taper handle is coded "JT". The utility model is characterized in that: the flange has a small thickness; there is a positioning notch for loading the knife; the two end key grooves are asymmetrically distributed.

7:24 tool taper shank for automatic tool changer is divided into A type, AD type and B type in German standard DIN 69871-1: A type is threaded bottom hole is unreachable; AD type is threaded bottom hole through; Type B is supplied to the flange end face. While DIN 69871-2 is only a type C, it is a double parallel flange, no V-shaped groove, and is rarely used now. Although the tool taper shank code is not specified in the standard, its code name in Germany is usually called "SK".

The Japanese standard JIS B 6339:1998 for 7:24 tool taper shank for automatic tool changer has replaced the Japan Work Machinery Industry Association standard MAS-403:1975, but because of its main external dimensions, it has no effect on the use, so The MAS-403 standard code is still marked on many manufacturers' samples, but JIS B 6339 is not marked. However, it should be noted that the rivets used in these two standards are different. The tool taper shank code is “BT, the characteristic is: the flange thickness is large; the V-shaped groove is asymmetrically distributed, close to the working part side; the two end key grooves are symmetrically distributed; the end keyway is not milled.

The American standard AMSE B5.50-1994 with 7:24 tool taper shank for automatic tool changer has replaced ANSI/AMSE B5.50-1985. Similarly, many manufacturers still mark ANSI/AMSE on the sample due to the same external dimensions. B5.50, or just ANSI. Although the tool taper shank code is not specified in the standard, it is usually called "CAT", which is characterized by: the flange thickness is small; the two end keyways are asymmetrically distributed; the identification hole is drilled on the bottom surface of one end keyway For tool positioning. The tail thread should be UNC thread, which is changed by the domestic manufacturer for the user's use, and the corresponding metric thread is changed.

The Chinese national standard GB 3837.3-83 for manual tool change with 7:24 tool taper shank is equivalent to the international standard ISO 297-82. It is characterized by no V-groove on the flange and the two end keyways are symmetrically distributed. The small end of the taper shank has a cylindrical tail, and the length of the taper shank portion of the tool is large. In China, the tool taper shank code is "ST". For general purpose milling machines.

The mechanical industry standard JB 3381.1-83 for manual tool change with 7:24 tool taper shank is a tool taper for CNC milling machines without robots and magazines. The feature is that there is no V-shaped groove on the flange, the two end key grooves are symmetrically distributed, and the small end of the taper shank does not have a cylindrical tail. In China, the tool taper shank code is also “ST”, so it is easy to be confused with the 7:24 tool taper shank with cylindrical tail. Therefore, the user must specify whether or not to have a cylindrical tail when ordering. WST" to show the difference). Although the standard has been replaced by the national standard GB 10944-89, there is still a need for users. Therefore, it is recommended to solve the legality of the standard and the problem of naming the tool taper code when the standard is revised or formulated in the future.

In addition to the manual tool change with a cylindrical tail, the 7:24 tool taper shank does not require a pull stud. The other 7:24 tool taper shank requires a rivet to be used, and its external dimensions depend on the standard used.

The national standard GB 10945-89 "7:24 taper tool handles for automatic tool changers, 40, 45 and 50 taper shank pull rods" is based on the international standard ISO 7388/2-1984, the same size, divided into Type A and Type B: The tension angle of the A-type rivet is 15°, which is used for the tensioning device without steel ball, codenamed “LDA”; the angle of the tension surface of the B-type rivet is 45°, a tensioning device for steel balls, codenamed “LDB”. Both have through holes for coolant circulation.

The German standard DIN 6988-1987 has two types of rivets, A and B. The A type has a through hole. The B type does not have a through hole, but there is an annular groove for the sealing ring to prevent the coolant from leaking from the tail. Both types of rivets have a slant angle of 15° for tensioning devices without steel balls.

The Japanese standard JIS B 6339:1998 has only one type of pull stud, and the pull surface of the pull stud is inclined at 15° for the tensioning device without steel ball, code name “xxP”. The standard MAS-403 of the Japan Working Machinery Industry Association has two types: Type I and Type II: the tension angle of the tension type of the type I rivet is 30°, which is used for the tensioning device without the steel ball; The tensioning surface of the nail is 45°, which is used for the tensioning device with steel balls. It should be noted that the length of the head of these two kinds of rivets is smaller than the diameter of the stylus head of JIS B 6339:1998 standard, and the length of the neck is long, and its code name is "PxxT".

The American standard AMSE B5.50-1994 has only one type of pull stud, the pull surface of the pull stud is inclined at 45°, and there is no centering cylinder between the flange and the thread. The thread should be made of UNC thread. The domestic manufacturer is also convenient for the user, and it is also changed to the corresponding metric thread. The other dimensions are unchanged.

The international standard ISO 12164-1:2001 for 1:10 hollow short taper shank basically adopts the German standard DIN 69873-1. The main difference is that the taper of the shank is changed from 1:10 to 1:9.98 to ensure that the diameter of the big end is first contacted when the taper shank is fitted with the mounting hole; only the theoretical correct size of the large end diameter is specified, and the large size is eliminated. Small end diameter and its tolerance; the distance between the large and small end diameters is eliminated; the marking method of the tail end keyway rounding is changed; the type of the empty sipe of the taper shank and the flange end face is specified in the normative appendix And size; balanced areas are recommended in the informative appendix. Unfortunately, the taper tolerance and the big end diameter tolerance of the taper shank are not specified. It is divided into two types: A type and C type: type A is used for automatic or manual tool change; type C can only be used for manual tool change. Due to the double positioning of the tapered surface and the end surface, the axial and radial positioning accuracy is high; the friction between the key and the tapered surface and the end surface of the tail end is large; the length of the taper shank is short, the weight is light, and the tool change is fast; Used, so it was quickly promoted.

Although the KM type 1:10 hollow short taper shank of the US Kenner Company appeared earlier, it has not been adopted as an ISO standard due to structural and technological defects, and is currently used more on CNC lathes.

The Capto series of Sweden's Sandvik Company and the NOVEX series of Walter Company of Germany are enterprise standards, and their applications have certain limitations and will not be introduced here.