ASME B5.50:2015 pdf free download – 7/24 Taper Tool to Spindle Connection for Automatic Tool Change
This Standard pertains to the standardization of basic toolholder shank, retention knob, and socket assemblies for numerically controlled machining centers with auto- matic tool changers. The requirements contained herein are intended to provide toolholder interchangeability between machining centers with automatic tool chang- ers of various types. This Standard is the inch solution for basic toolholder shank, retention knob, and socket assemblies. This design specifies an interchangeable retention knob with a 45-deg clamping surface. Section 2 of this Standard specifies the dimensions and tolerances of toolholder shanks having 7/24 tapers intended for automatic tool change. These are intended for use with the corresponding basic retention knob and spindle sockets specified in sections 3 and 4 (see Table 1). Section 3 contains information for standardization of retention knobs for use with the 7/24 connection system described herein (see Table 2). Section 4 specifies the dimensions and tolerances of spindle sockets, drive keys, and key seats for machine tool spindles having 7/24 tapers intended for automatic tool change (see Table 3 and Fig. 1). These are intended for use with the corresponding basic toolholder shank and retention knob specified in sections 2 and 3.
1.2 Noninterchangeability
Tool shanks conforming to ASME B5.18-1972 (R2009) and ASME B5.40-1977 (R2013) are not interchangeable with tool shanks established in this Standard. Tool shanks conforming to ISO 7388-1:1983 and retention knobs per ISO 7388-2:1984, types A and B are not inter- changeable with this Standard. This also applies to addi- tional shankand knob designs that are inthe draftstages within the ISO standards development system. Accord- ingly, the reader should note the warning statement included with the retention knob specifications shown in Table 2. Some incompatibility with existing automatic tool change arms may arise from dimension M (Table 1).
This Standard covers a basic toolholder shank with an inch threaded retention knob with 45-deg clamping surface that is applicable to general-purpose machining 1 centers where loading and exchange of toolholders are accomplished by automatic means. The term general purpose is intended to differentiate between machine designs for unusually high accuracy requirements and designs intended to function with exceptionally high spindle rotational speeds coupled with higher axis feed rates, such as is normally found in high-speed machin- ing. Tool shanks made to this Standard may be used with a variety of proprietary retention and/or flange locking systems.
1.4 Definitions
automatic tool changer (ATC): mechanism for the transfer of the toolholder between a storage feature and the spin- dle or nonrotating socket. balance: when the mass centerline and rotational center- line of a rotor are coincident. basic cone: geometrically ideal conical surface that is given by its geometrical dimensions. These are a basic cone diameter, the basic cone length, and the basic rate of taper, or the basic cone angle. basic toolholder shank: unit that fits directly into the spin- dle or nonrotating socket of the machine and has provi- sion for automatic tool change. coolant hole: passage through the center of the retention knob that allows through-the-spindle coolant to pass. This hole also permits access to a tool set height adjust- ment screw if so equipped. drive key: device intended to assist in delivery of the driving torque from the spindle nose to the tool. effective case: depth within a metal part, measured from the part’s surface, where the minimum required hard- ness is present. retention knob: member of the toolholder retention sys- tem that provides a coupling point between the tool- holder taper and the spindle drawbar. spindle: component assembly of the machine tool, the function ofwhich is to accept the basic toolholder shank. spindle nose: the part of a spindle into which the tool shank is accepted.