Tool changing – Including machine tool or component – Rotary spindle machine tool
Reexamination Certificate
1999-11-10
2002-05-14
Briggs, William (Department: 3722)
Tool changing
Including machine tool or component
Rotary spindle machine tool
C029S040000, C409S203000, C409S213000, C409S217000, C483S001000, C483S031000
Reexamination Certificate
active
06387025
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a machining device equipped with a spindle position interchanger, and a method for interchanging spindle positions.
2. Description of the Related Art
The outline of an example of a conventional machining center is shown in
FIGS. 8 and 9
. As shown in
FIGS. 8 and 9
, this machining center comprises a longitudinal table
02
provided on a bed
01
and movable in a horizontal direction, a transverse table
03
provided on the longitudinal table
02
and movable in a direction perpendicular to the table
02
, a column
04
erected on the transverse table
03
, a spindle head
05
vertically movable along the column
04
, a main spindle
06
attached to the spindle head
05
, a tool change arm
08
for changing a tool
07
in the main spindle
06
, and a tool magazine
010
housing many tools
09
. In
FIG. 9
, the reference numeral
031
denotes a base plate for the bed,
032
denotes a ball screw and a support bearing,
033
denotes an X-axis slide cover,
034
denotes a Z-axis rear slide cover,
035
denotes a spindle and a motor,
036
denotes an ATC motor,
037
denotes a strut, and
038
denotes a control panel.
The above-described machining center has the main spindle
06
, the tool change arm
08
adapted for the main spindle
06
, andthemagazineolo storing the tools
09
. Thus, this machining center can perform various types of machining one after another while changing the tool
07
in the main spindle
06
for a selected tool
09
in the tool magazine
010
by the use of the tool change arm
08
. This tool change is carried out by moving the spindle head
05
to a predetermined tool change position, stopping rotation of the main spindle
06
, gripping both of the tool
07
in the main spindle
06
and the tool
09
in the tool magazine
010
by the tool change arm
08
, and turning the tool change arm
08
. After completion of this tool change, the main spindle
06
is restarted. After a wait until the main spindle
06
reaches a predetermined revolution speed, a subsequent machining operation is performed.
In connection with the tool change, the following actions occur on the main spindle
06
: {circle around (1+L )} Stoppage (deceleration) of the main spindle
06
, {circle around (2+L )} change from the tool
07
in the main spindle
06
to the tool
09
selected from within the tool magazine
010
, and {circle around (3+L )} restart (acceleration) of the main spindle
06
after tool change. Periods of time required for these actions are added one to another sequentially.
How to reduce the times for the actions has been studied to ensure high efficiency and increased productivity on a machining line for mass production. However, the main spindle is present at one site only, so that the main spindle rotating at a high speed needs to be stopped. Thus, it has been difficult to shorten the time necessary for tool change. Particularly, as the frequency of tool change increases, this tool change time is accumulated, resulting in a decrease in productivity. To shorten the machining time, it is required to make the rotation of the main spindle as fast as possible. However, the time necessary for deceleration or acceleration is prolonged, failing to fulfill the requirement for reduction of the tool change time.
With a conventional machining device, therefore, a proposal has been made to provide two main spindles on a machining side, as shown in
FIG. 10
, and to move and control these main spindles individually. As illustrated in
FIG. 10
, this machining device has two spindle heads
025
,
026
vertically movable along columns
023
,
024
by respective feed motors
021
,
022
, and has main spindles
027
,
028
installed on the spindle heads
025
,
026
. A tool magazine
029
is common to the main spindles
027
,
028
, and indexing and longitudinal movement of the tool magazine
029
result in the change of respective tools. A workpiece is mounted on a table
030
.
Such a machining device has the two main spindles provided on the machining side in changing tools. Thus, the movement of the tools during tool change may induce interference with the workpiece, thereby limiting the timing of tool change. Furthermore, the spindle heads
025
,
026
are present for the columns
023
,
024
, respectively, thus upsizing the entire machining device, and making the area of installation large. In addition, the distance between the two main spindles diminishes the effective moving distance to and from the workpiece.
SUMMARY OF THE INVENTION
The present invention has been accomplished to solve the foregoing problems with the earlier technologies.
According to a first aspect of the present invention, there is provided a machining device equipped with a spindle position interchanger, which has a spindle head vertically movably mounted on a moving column horizontally moving in longitudinal and transverse directions, the machining device comprising a turret unit provided on the spindle head rotatably about a turning axis; a plurality of main spindles provided on the turret unit, positions of the main spindles being interchangeable by rotation about the turning axis; spindle drive motors coupled to the respective main spindles; and a tool changer for performing tool change for the main spindle located at anon-machining position. Thus, even during indexing for spindle position interchange, the tool in the main spindle can keep rotating. Hence, during machining using a certain main spindle, the tool in another main spindle can be rotated beforehand, and can be put into machining immediately after indexing for the main spindle. Consequently, the non-cutting time can be decreased, the cycle time for machining can be shortened, so that productivity per machining device is increased. Using the same number of the machining devices of the present invention as the number of the conventional machining devices will make increased production possible. On condition that the same amount of work is to be machined, the use of the machining device of the present invention can decrease the required number of the machining devices.
According to a second aspect of the present invention, there is provided a method for interchanging spindle positions in a machining device equipped with a spindle position interchanger, the machining device having two or more main spindles connected to spindle drive motors, and the machining device including the spindle position interchanger for interchanging positions of the two or more main spindles by rotation about a turning axis, and a tool changer for changing a tool for at least one of the main spindles, the method comprising performing machining with the use of one of the main spindles, while changing a tool mounted on a different one of the main spindles; then starting rotation of the different main spindle; and then interchanging positions of the one main spindle and the different main spindle by rotation about the turning axis. Furthermore, machining is immediately started by use of the tool in the different main spindle after spindle position interchange. Thus, the time for tool change done while stopping the rotation of the main spindle, as in the earlier technology, becomes unnecessary. Moreover, if the revolution speed of the main spindle having a tool, which will replace the tool in current use for machining, is raised to a predetermined revolution speed before spindle position interchange, machining can be immediately started after spindle position interchange, so that the non-machining time can be reduced markedly.
According to a third aspect of the present invention, there is provided a method for interchanging spindle positions in a machining device equipped with a spindle position interchanger as recited in the second aspect, wherein the one main spindle during machining is provided so as not to interfere with the different main spindle when the tool is changed. Thus, tool change can be performed on the side opposite to the side on which machining is carried out. There is
Kawagoe Katsumi
Konishi Mitsuyuki
Takehana Isamu
Watanabe Akira
Briggs William
Mitsubishi Heavy Industries Ltd.
LandOfFree
Machining device equipped with spindle position interchanger... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Machining device equipped with spindle position interchanger..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Machining device equipped with spindle position interchanger... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2860733