Loader control device

Details Loader control device Loader control device

2001-11-19

2004-08-31

Picard, Leo (Department: 2125)

Data processing: generic control systems or specific application

Specific application, apparatus or process

Product assembly or manufacturing

C700S173000, C700S192000

Reexamination Certificate

active

06785584

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to a loader control device for controlling a loader which carries out a delivery of works to an outer machine such as machine tools.
BACKGROUND OF THE INVENTION
According to an automatic machine tool of NC lathe or the like, a loader is attached to the machine tool main body, and the work is transported in and out automatically. In the loader of gantry loader or the like, there are several important locating positions during the operation of a series of a cycle. For example:
a. load/unload position to the spindle chuck,
b. load/unload position to the work reversing machine,
c. delivering position between other transporting device.
Generally, the setting of these positions are carried out by a professional operator in advance to the starting of mass production, by a so-called work, “instruction”, and is handled as a fixed position during mass production.
However, during mass production, there are cases in which the locating fails even by forcibly appointing to the position by using the fixed value, due to various changes in the condition, such as a mechanic saccadic movement, deterioration of the mechanism parts, and changes in the material differentiation. For example, there are cases in which it leads to a breakdown or an accident wherein it proceeds to processing under impossible posture wherein defective articles are produced, and a work falls off from the chuck or the like during processing. In some cases, the breakdown can be prevented beforehand by stopping the abnormal load alarm of the loader axis, and defects generate in that the operating rate decreases.
It is thus an object of the present invention to provide a loader control device capable of preventing the generation of abnormal operation of the loader or the delivery mistakes due to the core displacement of the chuck when delivering a work to the chuck of an outer device.
It is another object of the present invention to facilitate the adjustment of the work delivering position just by changing the coordinates.
It is still a further object of the present invention to prevent the abnormality reflecting on the next processing when an abnormality generates.
SUMMARY OF THE INVENTION
The present invention will now be described in reference to
FIG. 1
which corresponds to the embodiment. A loader control device is a loader control device
20
for controlling a loader
5
which delivers a work W to a chuck
2
of an outer device
1
. Moreover, the loader control device comprises a displaced amount detecting means
31
and an adjusting means
32
. The displaced amount detecting means
31
detects by the torque of the motors
11
,
12
of the loader
5
, the displacement of a center position of a loader chuck
14
and a center position of the chuck
2
of the outer device
1
, when a work W is delivered with the loader chuck
14
placed on the work delivering position. The adjusting means
32
adjusts the work delivering position of the loader chuck
14
by an amount corresponding to the detected displaced amount when delivering the next work W.
According to this structure, the position of the loader chuck
14
is fixed to the work delivering position instructed beforehand, and the work W is delivered to the chuck
2
of the outer device
1
. When the work W is held by the chuck
2
of the outer device
1
and becomes under a restricted state, in the case a displacement has occurred between the center position of the loader chuck
14
and the center position of the chuck
2
of the outer device
1
, the torque of the motors
11
,
12
for transferring the chuck position of the loader
5
increases. The displaced amount detecting means
31
detects the displacement of the center position of the loader chuck
14
and the center position of the chuck
14
of the outer device
1
, by the torque under the restricted state. The adjusting means
32
adjusts the work delivering position of the loader chuck
14
by the amount corresponding to the displaced amount detected by the displaced amount detecting means
31
when delivering the next work W. Therefore, even when a displacement is generated in the appropriate work delivering position due to various changing factors from the time the work delivering position is instructed, the work W can be delivered by adjusting the displacement constantly. As a result, the abnormal operation of the loader or the delivering failure due to the displacement in the core of the chucks
2
,
14
can be prevented from generating. Further, the adjusting amount can be the same as the displaced amount or can be in a predetermined ratio to the displaced amount.
Moreover, the outer device
1
mentioned here is a device different from the loader
5
, and for example, when the loader
5
is embedded inside the machine tool of the lathe or the like, the outer device
1
can be a section other than the loader in the machine tool. The chuck
2
of the outer device
1
is a chuck of the device delivered with a work W from the loader
5
.
According to the present invention, the loader
5
operates by the coordinate data of the work delivering position appointed by the loader program
21
, and can carry out an adjustment of the work delivering position by either rewriting the coordinate data or adding revised amount based on aforementioned displaced amount. The specification of the work delivering position by the loader program
21
is carried out by the identifying code {circle around (
1
)}, {circle around (
2
)}, {circle around (
3
)} . . . of the work delivering position, and the coordinate data corresponding to the identifying code can be stored in the locating position setting means
23
, and the work delivering position can be specified by the coordinate data directly to the loader program
21
.
In either case, based on the detected displaced amount, by rewriting the coordinate data or by adding the revised amount, the adjusting of the work delivering position can be carried out easily. When storing the coordinate data to the locating position setting means
23
, the rewriting of the coordinate data based on the displaced amount is to be for example, rewriting the stored coordinate data itself. When writing the coordinate data to the processing program
21
, for example, the coordinate data of the processing program
21
is to be rewritten. When adding the revised amount based on the displaced amount, for example, revising can be added when outputting the operational command by the coordinate data set in the locating position setting means
23
or in the processing program.
According to the present invention, when the torque of the motors
11
,
12
is larger than the set value, a processing means during excess load
33
for stopping the adjustment of the delivering position by the adjusting means
32
can be provided.
When the torque of the motors
11
,
12
is excessive, it can be assumed that some abnormality, exceeding tolerance level, has occurred. In such case, the adjustment of the delivering position by the adjusting means
32
is stopped, and the abnormality in the adjustment is prevented by the processing means during excess load
33
. The judgment whether or not the torque of the motor is larger than the set value can be carried out after converting the torque of the motor into the displaced amount. Moreover, the process to stop the adjustment by the adjusting means
32
can be made not to carry out the adjusting process accordingly, by stopping the displaced amount being input to the adjusting means
32
.
Further, according to the present invention, a correlation setting means
34
which sets the correlation of the motor torque and the displaced amount can be provided, and the displaced amount detecting means
31
can figure out the displaced amount by referring the detected torque to the correlation setting means
34
.
As in the manner stated above, by providing the correlation setting means
34
, the displaced amount can be instantly found from the torque value.


REFERENCES:
patent: 5436845 (1995-07-01), Takahashi
patent: 5742138 (1998

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