JPH08174363A - Machine tool - Google Patents

Abstract

PURPOSE: To reduce a waste time to a minimum by providing a means to control an automatic tool exchange means to perform preparation for machining in such a manner that one tool is exchanged while machining is effected by using the other tool. CONSTITUTION: When, while one main spindle head, for example, 13b is continued to effect machining of a work, a tool attached to the other main spindle head 13a is exchanged, rotation of the main spindle head 13a is first stopped according to a command from a controller. Simultaneously, the main spindle head 13a is moved to a tool exchange position adjoining an ATC 12a. The tool is then exchanged by using the ATC 12a. When exchange of a tool is completed, the number of revolutions of the main spindle head 13a is increased to a given value and waiting is effected in a waiting position. When machining by the main spindle head 13b is completed, transfer to the stop of rotation of the main spindle of the main spindle head 13b and tool exchange operation is carried out. Simultaneously therewith, the main spindle head 13a is moved from the waiting position to a machining position to start machining.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a machine tool such as a machining center for drilling, milling, etc., and more particularly to a machine tool capable of moving a tool in three-dimensional directions.

[0002]

2. Description of the Related Art In recent years, FMS has been used as an automated production system.
(Flexible Manufacturing System) has been introduced. Most of the machine tools used in FMS are machining centers.

FIG. 7 is a front view (A) and a side view (B) showing a machining center as an example of a conventional machine tool 50. Referring to FIGS. 7A and 7B, a conventional machine tool 50 includes a column 51 having a spindle head 53 to which a cutting tool is attached, and an X-direction movement for moving the column 51 in the X direction in the drawing. Means 55 and Z direction moving means 5 for moving the X direction moving means 55 in the Z direction in the drawing.
6 and a controller 60 for controlling the machine tool 50.

The movement of the main shaft 53 in the Y direction in the drawing is performed by the column 51.
It is performed by a lifting drive mechanism 54 provided inside.
The column 51 holds a plurality of cutting tools to be attached to the spindle 53, and replaces the tools as needed.
(Automatic Tool Changer) 52 is included. When it is necessary to replace the tool provided on the main shaft 53, the main shaft 53 is moved in the Y direction in the drawing using the elevating drive mechanism 54, and at the moved predetermined position, the tool provided on the ATC 52 is replaced. It

[0005]

The conventional machining center as a machine tool used in the FMS is constructed as described above. When the machining center is used in FMS, in order to minimize the so-called dead time in which no machining is performed, various measures have been taken such as increasing the moving speed of each axis and increasing the automatic tool changing speed.

However, when exchanging the tool, the rotation of the tool is inevitably stopped and the spindle 53 is moved to the ATC 52.
It was necessary to move in the Y direction to the position and replace the tool at that position. That is, in exchanging the tool, while stopping the rotating main spindle 53, it is moved to a predetermined tool exchanging position, and the tool is exchanging there.
It was necessary to rotate it again at the processing speed and move it to a predetermined working position.

In this case, even if the tool-to-tool time for exchanging only the tool is shortened, the spindle is stopped from the predetermined spindle speed and moved to the position of the ATC 52, and after the exchange, The time to move the spindle up to the machining speed and move to the machining position is added. This time increases as the spindle rotation speed increases, and the so-called chip to chip (chip to chip) from the end of chip generation by the previous tool to the chip generation by the next tool
There was a problem that it would lead to an increase in time.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a machine tool capable of minimizing the dead time.

[0009]

A machine tool according to the present invention includes a movable member movable in a first direction, and the movable member rotatably holds a cutting tool at each end in the first direction. An automatic tool including first and second tool holding means for exchanging tools held by the first and second tool holding means independently of each other and preparing for working to satisfy a predetermined working condition An exchange means and a means for controlling the automatic tool exchange means so as to exchange the tools held by the second tool holding means and prepare for processing while the first tool holding means is performing the processing using the first tool. Including and

[0010]

In the machine tool according to the present invention, the second tool is replaced while the work is being processed by the first tool, and preparations for the next processing are made. Therefore, the tool-to-tool time, the spindle rotation stop time, and the rise time can be set to 0, and the chip-to-chip time can be greatly reduced.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a front view of a machining center as an example of a machine tool according to the present invention, and FIG. 2 is a side view thereof.
FIG. 3 is a plan view.

1 to 3, the machining center 10 includes a pair of spindle heads 13 for holding a machining tool.
A column 11 having a and 13b mounted on the front surface thereof, a Z-direction moving device 21 for moving the column 11 in the Z-direction in which the table 15 holding the work is placed, and a Z-direction moving device 21 are mounted. An X-direction moving device 25 for moving the column base 20 in the X direction in the drawing, and the machining center 1
The controller 30 controls the movement of the entire zero.

The column 11 has a pair of spindle heads 13a,
A lifting drive mechanism 14 for moving 13b in the Y direction in the figure.
a, 14b and a pair of ATs for exchanging tools attached thereto for a pair of spindle heads 13a, 13b
C12a and 12b are provided. A pair of spindle heads 13
a and 13b are independently movable in the Y direction. For example, while one spindle head 13a is processing a work (not shown), the other spindle head 13b is moved to a position close to the ATC 12b, and the spindle head 13b is there. It is possible to replace the tool attached to. FIG. 2 is a diagram showing such a state, in which one spindle head 13a is
When the workpiece is being machined at the position 3a ', the other spindle head 13b is located at the tool exchange / replacement position 13b'.

The Z-direction moving device 21 includes a ball screw 22 for moving the column base 11 in the Z direction, a motor 23 for rotationally driving the ball screw 22, and a pair of sliding rails for slidably supporting the column 11. 24a and 24b are included. The X-direction moving device 25 includes a ball screw (not shown) for moving the column base 20 in the X-direction, a motor 26,
Sliding rails 27a for slidably supporting the column base 20,
27b and.

Next, a tool changing operation in the machining center according to the present invention will be described. FIG. 4 is a flow chart for explaining the operation in the case where the tool attached to the other spindle head 13a is exchanged while one spindle head, for example 13b, continues to machine a workpiece. With reference to FIG. 4, the tool exchange procedure will be described by taking the case of exchanging the tool attached to the spindle head 13a as an example.
When receiving a command from the controller 30 that the tool attached to the spindle head 13a should be replaced, first, the rotation of the spindle head 13a is stopped (step S11, the following steps are omitted). At the same time, the main spindle head 13a is the
Is moved to the tool exchange position adjacent to (S12). Next, the tool is replaced using the ATC 12a (S1).
3). When the tool replacement is completed, the spindle head 13a is rotated up to a predetermined rotation speed (S14) and stands by at the standby position.

When the machining of the spindle head 13b is completed, the spindle rotation of the spindle head 13b is stopped and the tool changing operation is started. At the same time, the spindle head 13a is moved from the standby position to the machining position and machining is started. In this case, only the x-axis coordinate is d in the figure.
It is possible to switch to a machining program that has been shifted.

As described above, in the machining center 10 according to the present invention, the pair of spindle heads 13a and 13b are provided in the single column 11, and the pair of spindle heads 13 is provided.
a and 13b can be independently moved in the Y direction, but in the X and Z directions orthogonal thereto, the column 1
X direction moving device 25 and Z direction moving device 21
Each is provided with only one set. Therefore, it is possible to reduce the number of driving devices and the like as compared with the case of performing the same operation using a pair of machining centers having a single main spindle head, so that it is possible to reduce the cost as compared with that case. Moreover, since the pair of spindle heads 13a and 13b are configured to move in the same column, the chip to chip time can be shortened by a simple program change.

In the above embodiment, the case where the present invention is applied to the machining center of the type in which the table for holding the work is fixed has been described, but the invention is also applied to various types of moving the table as shown in FIG. It goes without saying that it is good. In this case, it is not necessary to move the column in the direction in which the table is moved.

Further, in the above embodiment, the case where the so-called magazine direct system is adopted as the ATC has been described, but the same can be applied to the case of the ATC using a swing arm.

Further, in the above embodiment, the case where the present invention is applied to the horizontal machining center in which the horizontal spindle head moves up and down in the vertical direction has been described. However, in the vertical machining center as shown in FIG. You may apply.

[0021]

As described above, according to the present invention, the tool held by the second tool holding means is exchanged for machining while the first tool holding means is machining using the first tool. The automatic tool changer is controlled to make the preparation. Therefore, the second tool is replaced while the work is being processed by the first tool, and preparations for the next processing are made. Therefore, the chip-to-chip time can be greatly shortened. As a result, it is possible to provide a machine tool that can minimize the dead time.

[Brief description of drawings]

FIG. 1 is a front view of a machine tool according to the present invention.

FIG. 2 is a side view of the machine tool according to the present invention.

FIG. 3 is a plan view of a machine tool according to the present invention.

FIG. 4 is a flowchart showing a tool changing operation of the machine tool according to the present invention.

FIG. 5 is a diagram showing various types of horizontal machining centers.

FIG. 6 is a diagram showing various types of vertical machining centers to which the present invention can be applied.

FIG. 7 is a schematic diagram showing a schematic configuration of a conventional machine tool.

[Explanation of symbols]

 10 Machine Tools 11 Columns 12a, 12b ATC 13a, 13b Spindle Heads 14a, 14b Elevating Drive Mechanism 15 Table 30 Controller

Claims (1)

[Claims] 1. A moving member movable in a first direction, wherein the moving member has first and second tool holding means respectively rotatably holding a cutting tool at an end portion of the first direction. And an automatic tool changer for exchanging tools held by the first and second tool holders independently of each other and preparing for machining so as to satisfy a predetermined machining condition, and the first tool holder. A means for controlling the automatic tool changing means to replace the tool held by the second tool holding means and prepare for the processing while the means is performing the processing using the first tool. machine.