数控车床刀库设计参考文献英文

数控车床刀库设计参考文献英文

DESIGN OF AN AUTOMATIC TOOL CHANGER WITH DISC

MAGAZINE FOR A CNC HORIZONTAL MACHINING

CENTER

Abstract--Automatic tool changers (ATCs) are devices used in CNC machine tools to exchange the tool in the spindle with the tool in the magazine. In this paper, the design of the ATC of a CNC horizontal machining center which was realized for a CNC machine tool manufacturer is introduced. After examination of several alternatives, it was decided to implement the disc-type ATC. A magazine was designed with 24 tools with a maximum tool diameter of 150 mm and a maximum tool weight of 8 kgf. The designed ATC can change the closest tool within 4 s and the

tool farthest away within 6 s. ? 1997 El~vier Science Ltd. All fights reserved 1. INTRODUCTION

Any machine tool manufacturer must either pay for the patent of any particular CNC machine tool, or design its own system to manufacture CNC machine tools. Buying a new technology is an expensive alternative, and it is not generally allowed to make any modifications and developments on the purchased system. The machine tool manufacturers refrain from selling new technologies developed by themselves, and they are generally willing to sell their abandoned technologies.

Therefore, a particular CNC machine tool manufacturer has started research and development studies for the design and production of a new

CNC horizontal machining center. It was required to design a new system

of ATC for this particular machine tool.

An ATC can be defined as a device which can select and change tools from a tool storage magazine according to the commands given by the machine control unit.

Various types of ATC with quite different working principles have

been used in horizontal machining centers produced by the different machine tool manufacturers [1-17]. A tool storage magazine is generally either a chain type or a disc (carousel) type. However, nowadays, there are some other types of magazines such as spherical, cassette, etc. [17].

Disc-type magazines may be categorized according to the functions of the discs.

(1) In a "disc with a changer arm"-type magazine, the tools are changed by means of an arm which takes the tool from the magazine and exchanges it with the one in the spindle. Therefore, the disc has the functions of indexing and storing the tools only [1-5]. Some examples of this type are shown in Fig. l(a) [1], Fig. l(b) [1] and Fig. l(c) [5].

(2) A "disc without a changer arm"-type magazine acts like a tool changer arm. The tools are changed by the disc itself [2, 6--8]. An example of this type is shown in Fig. 2 [1 ]. As shown in the figure,

two disc magazines and two spindles mounted on a turret exist in this application.

In an ATC with chain-type magazines [9-16], the tool is changed by a changer arm. Chain-type magazines may be categorized according to the