JPH04340104A - Loader control device - Google Patents

Abstract

PURPOSE:To apply this control device to a loader such as a lathe and to eliminate necessity for teaching loading and unloading positions even at the time of changing works with different lengths. CONSTITUTION:The loader control device is provided with a position detecting means 21 for detecting a moving position of a loader chuck 12 in the Y axis direction, a deviation arithmetic means 26 for calculating a deviation V between the detection value of the means 21 and a position command value and a skip command means 31 for allowing a program to chuck opening/closing operation to be the succeeding operation command. When the chuck 12 is moved down and abutted upon the work W on a work feeding board 13, the chuck 12 is closed and operated. Similar control is applied also in the X axis direction to load the work W to the main spindle of the lathe.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loader control device such as a gantry loader installed in a machine tool such as a lathe.

0002

2. Description of the Related Art In a gantry loader, one end of a workpiece is gripped by a loader chuck, and the workpiece is transported between a workpiece supply table and a spindle chuck. The receiving and delivering position of the loader chuck with respect to such a workpiece supply table and spindle chuck needs to be changed by the difference when the length of the workpieces differs.

[0003] Conventionally, therefore, the receiving/delivering position of the loader chuck is taught each time a lot of workpieces of different lengths are changed. This teaching is performed, for example, by operating the loader in manual mode. However, such teaching operations are complicated and require time and effort to change setups. In particular, in a two-axis lathe or the like, the number of teaching points is 10 or more, so the teaching operation takes a considerable amount of time.

In order to solve this problem, a workpiece detection switch 5 is installed in the loader chuck 50 as shown in FIG.
1, the loader chuck 50 descends and the table 52
Attempts have been made to close the loader chuck 50 when the switch 51 is turned on by the workpiece W above.

[0005]

[Problems to be Solved by the Invention] According to this configuration, operation can be performed without teaching the receiving position of the workpiece W. However, the work W held by the loader chuck 50
This method cannot be applied to the case where the switch 51 remains on regardless of whether the loader chuck 50 reaches the delivery position or not. Moreover, it is necessary to provide the switch 51 on the loader chuck 50,
Since it is necessary to conduct the wiring from the loader chuck 50 to the control device, there is a problem that the wiring system becomes complicated.

[0006] An object of the present invention is to provide a loader control device that can be operated without teaching the receiving and delivery positions and does not require a complicated wiring system.

[0007]

[Means for Solving the Problems] The structure of the present invention will be explained with reference to FIG. 1 corresponding to an embodiment. This invention provides a loader control device (28) that sequentially executes each operation command, including a drive device (16) for moving a loader chuck (12),
(18) is applied to a controller (25) having an axis movement command means (23) for giving an axis movement command (Q) in accordance with a position command value.

In the above configuration, the loader chuck (12
) position detection means (20), (21
), and a deviation calculating means (26) for calculating the deviation (V) between the detected value of the means (20), (21) and the position command value.
and a skip command means (31) for skipping to the next operation command of the axis movement command being executed when the deviation (V) reaches the set value (a).

[0009]

[Function] According to this configuration, when the axis of the loader chuck (12) moves, the loader chuck (12) hits the workpiece supply table (13) or the workpiece (W) on the spindle chuck, and the loader chuck (12) cannot move. When it runs out, the deviation (V) between the actual position of the loader chuck (12) and the position command value
becomes larger. This deviation (V) is calculated by the deviation calculation means (26)
When the deviation (V) reaches the set value (a), the skip command means (31) skips to the next operation command, such as a command for a chuck closing operation. The same applies to the case where the loader chuck (12) grips the workpiece (W) and transfers the workpiece (W) to a workpiece discharge table or the like.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. 1 to 7. FIG. 2 is a schematic front view showing the lathe 1 and the loader 2. The lathe 1 consists of a turret lathe, and the main shaft 3
A turret carriage 6 carrying a turret 5 is installed on the side of the headstock 4 supporting the turret 5 so as to be movable laterally (in the X-axis direction).

The loader 2 has a traveling platform 8 installed on a rail 7 constructed above the lathe 1, and a lifting rod 10 installed on the traveling platform 8 via a back and forth moving platform 9. A loader head 11 is provided at the lower end of the lifting rod 10. The loader head 11 has two loader chucks 12 on the surface facing the main shaft 3 and on the lower surface, and the positions of both loader chucks 12 can be exchanged with each other by a turning mechanism (not shown). The chuck claws of each loader chuck 12 can be opened and closed by an actuator provided on the loader head 11. In the traveling range of the traveling table 8 of the loader 2, a workpiece supply table 13 and a workpiece discharge table 15 each consisting of a conveyor device
are arranged on both sides of the lathe 1.

FIG. 1 is an explanatory diagram showing the drive system and control system of the loader 2. As shown in FIG. The back-and-forth moving table 9 is driven forward and backward by a Z-axis servo motor 16 and a feed screw 17 installed on the traveling table 8, and the elevating rod 10 is driven by a Y-axis servo motor 18 and a rack and pinion mechanism 19 mounted on the back-and-forth moving table 9. It is driven up and down. Each axis servomotor 16, 18 has a position detector 20, 21, each consisting of a pulse coder or the like.

The loader automatic operation means 22 is a control device consisting of a CPU, a memory device, etc., and a numerically controlled loader control program is stored in the memory device. The loader automatic operation means 22 is provided with an axis movement command means 23 for moving the loader head 11 along a predetermined path, and a chuck opening/closing command means 24.

The axis movement command means 23 is a means for giving an axis movement command Q such as a rapid feed command or a skip feed command using a position command value consisting of a pulse train, and the axis movement command Q is inputted to the servo controller 25. The servo controller 25 receives the command value of the axis movement command Q and the position detector 20,
21 is calculated by a deviation calculation means 26 consisting of a deviation counter, and drives each axis servo motor 16, 18 via a servo driver 27. Although the servo controllers 25 are provided separately for each of the X to Z axes, the X and Z axes are omitted in FIG.

The loader automatic operation means 22, the servo controller 25, and the position detectors 20 and 21 constitute a loader control device 28. Loader automatic operation means 22
has an emergency stop means 29 in addition to the above, and the deviation V of the deviation calculation means 26 of the servo controller 25 is the error setting value b.
, c, a stop command H is output to the programmable controller 30 of the lathe 1 to stop the entire lathe 1 and loader 2. In addition, this stop command H causes the notification means (
(not shown) generates an alarm. Error setting values b, c
As will be described later, different values are set for fast forwarding and for low speed skip forwarding.

Loader control device 28 having such a basic configuration
In this invention, the automatic operation means 22 is provided with a skip command means 31. When the deviation V between the position command value during skip feeding and the detected value of the position detection signal F reaches a predetermined error setting value a, the skip command means 31 issues a command S to skip to the next operation command in the loader control program.
It is a means to output. This means 31 is constituted by step S4 in FIG. 6, which will be explained later.

Error setting value a for outputting the skip command S and each error setting value b in the emergency stop means 29
, c may be set in the loader control program, or may be set separately from the loader control program as reference parameters.

FIG. 5 shows the relationship between the magnitudes of each error setting value a to c. The error setting value b, which is used as an alarm (emergency stop) during skip feed, is set smaller than the error setting value c during rapid feed to ensure machine safety. The error setting value a for outputting the skip command S is set to a smaller value than the error setting value b for the alarm.

The operation of the above configuration will be explained. Loader 2 is
Under the control of the loader automatic operation means 22, the following operations are repeatedly performed. That is, the work supply table 13 in FIG.
Lower the loader head 11 above the supply position P of
The workpiece W is gripped by the downward loader chuck 12. After gripping, the loader head 11 is raised and travels above the main shaft 3. Here, the loader head 11 is lowered,
After receiving the processed work W on the main spindle 3 into the empty loader chuck 12 in front, the two loader chucks 12, 12
and transfer the workpiece W to the spindle 3. Next, the machine travels to the workpiece discharge table 15 and discharges the processed workpiece W received from the main spindle 3, and then goes to the workpiece supply table 13 to pick up the workpiece W again.

In the above-mentioned repeating process, the work supply table 13
Figures 4 and 6 show the operation when going to pick up the workpiece W.
I will explain it together. In FIG. 4, the loader head 11 is lowered by rapid feed (for example, G0 of the NC code) to the skip feed start position Ya. When descending to the fast-forwarding position Ya, skip-feeding (for example, G31) of descending at a low speed while limiting torque is executed (step S in FIG. 6).
1).

In the process of skip feeding, the destination command value Y
b (S2), the deviation V between the position detection signal F of the Y-axis position detector 21 and the position command value of the axis feed command Q is monitored by the skip command means 31 (S4). When the deviation V reaches the error setting value a, the lowering is stopped and the next operation, the chuck closing operation (S3), is skipped.

To explain this in conjunction with FIG. 3, in a servo system, the position detection value (F), which is generally a feedback signal, usually lags behind the command value (Q). is monitored, and if the error exceeds the set value a, a skip signal is output.

In the example shown in FIG. 4, when descending to the collision position Yc, the loader chuck 12 hits the workpiece W and cannot descend any further. Therefore, after this, only the command value increases and the deviation V gradually increases. When the command value increases to the position Yd where the deviation V reaches the error setting value a, the next operation is skipped and the loader chuck 12 grips the workpiece W. do.

Therefore, even if the workpiece W has different lengths, it can be gripped by the loader chuck 12. Therefore, it is no longer necessary to teach the receiving position of the loader chuck 12 every time the workpiece length differs.
Loader operation programs can be shared.

Furthermore, this loader control device performs skipping by using the output of the deviation calculation means 26 normally provided in the servo system, so there is no need for a dedicated switch or the like, and the area around the loader head 11 is There is no problem of a complicated wiring system.

The deviation V mentioned above is also monitored by the emergency stop means 29 shown in FIG. At this time, if the position command value continues to increase due to some problem and the deviation V exceeds the error setting value a for skip command output and reaches the skip feed error setting value b, an alarm will be generated. Make an emergency stop to ensure machine safety. In the case of fast forwarding, the normal value of the deviation V is larger than in the case of skip forwarding, so the error setting value c is set to a large value as shown in FIG. 5, and when this value c is reached, an emergency stop is performed.

The above explanation of the skip command is based on an example in which the workpiece W is received from the workpiece supply table 13.
When transferring the workpiece W to the workpiece discharge table 15, the loader chuck 1 is
A skip to the second opening operation is performed. In addition, as shown in FIG. 7, the workpiece W is
In the case of receiving and delivering, it is possible to operate without position teaching by issuing a skip command based on the monitoring of the deviation V, as described above. However, in this case, Z
A skip command is output according to the deviation between the position command value for the axis and the position detector.

In each of the above embodiments, in the case of skip feeding, when the error setting value a is exceeded, the skipping is always performed to the next operation, but the skip feeding means 31 is activated by a predetermined command in the loader control program. It may be possible to switch between the state and the disabled state.

FIG. 8 shows a portion of a loader control program containing such instructions. In the same figure, step R1
When moving the axis, if the positional deviation V becomes excessive, an alarm is generated and an emergency stop is triggered. Position deviation ignore command (R2)
If there is, and the positional deviation V becomes excessive during subsequent axis movement (R3), the next operation, the chuck opening/closing operation (R4), is executed instead of setting an alarm. When the position deviation ignore cancellation command (R5) is issued, until the position deviation ignore command is issued again, an alarm is generated when the position deviation becomes excessive, as in the case of the axis movement in step R1. With this configuration as well, no teaching is required when changing the setup for workpieces of different lengths. In this case, the position deviation ignore command (R
2) and the position deviation ignore cancellation command (R5) are, for example, commands for setting and resetting a predetermined flag, and the state of the flag is checked during axis movement to select either an alarm or a skip.

Although each of the above embodiments has been described with reference to the case where it is applied to a gantry loader, the present invention can be applied to various other types of loaders, such as an articulated robot type loader. Furthermore, when the movement of the loader chuck 12 to the delivery position involves simultaneous movement of multiple axes, the skip command means monitors the deviation for each axis, or monitors the deviation of only the predetermined axes that are moved simultaneously. Or, the next movement is skipped based on comprehensive judgment of each axis deviation.

[0031]

Effects of the Invention The loader control device of the present invention includes a position detecting means for detecting the moving position of the loader chuck, a deviation calculating means for calculating the deviation between the detected value and the position command value, and a set value for the deviation. Since the present invention is provided with a skip command means for skipping to the next operation command when the operation command is reached, it is possible to receive and deliver workpieces of various lengths without teaching the receiving and delivery position. Therefore, the burden on the operator when changing the type of workpiece can be significantly reduced. Moreover, since the skip is performed using the output of the deviation calculation means normally provided in the servo system, there is no need for a dedicated switch or the like, and there is no problem of a complicated wiring system.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram showing the configuration of a loader control device according to an embodiment of the present invention.

FIG. 2 is a front view of a lathe and a loader to which the loader control device is applied.

FIG. 3 is an explanatory diagram showing delays in the servo system in the loader control device.

FIG. 4 is an explanatory diagram of the work receiving operation.

FIG. 5 is an explanatory diagram showing the relationship between the respective error setting values.

FIG. 6 is a flowchart showing a part of the process of skipping from skip feeding to the next operation in the loader control program.

FIG. 7 is an explanatory diagram of the transfer operation between the main spindle chuck and the loader chuck.

FIG. 8 is a flowchart showing part of a loader control program in another embodiment.

FIG. 9 is an explanatory diagram of the operation of a conventional example.

[Explanation of symbols]

1... Lathe, 2... Loader, 3... Main spindle, 5... Turret, 8...
Traveling table, 9... Back and forth moving table, 10... Lifting rod, 11... Loader head, 12... Loader chuck, 13... Work supply table, 16... Z-axis servo motor, 18... Y-axis servo motor, 20, 21... Position detection 22... Loader automatic operation means, 23... Axis movement command means, 25... Servo controller,
26... Deviation calculation means, 28... Loader control device, 29... Emergency stop means, 31... Skip command means, a to c... Error setting value, H... Stop command, Q... Axis movement command, V... Deviation, W...
work

Claims (1)

[Claims] 1. A loader control device that has an axis movement command means for giving an axis movement command to a controller of a drive device that moves a loader chuck in accordance with a position command value, and that sequentially executes each operation command. A position detection means for detecting, a deviation calculation means for calculating the deviation between the detected value of this means and the position command value, and when this deviation reaches a set value, the next operation command of the axis movement command being executed. A loader control device comprising a skip command means for skipping.