JPH11333672A - Work conveying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a work conveying device to effect both movement of a work and measuring operation for the work by a sensor. SOLUTION: A control device for exclusive use to control movement of a work conveying device has a sensor 36 for measuring a work arranged in the vicinity of the gripper claw 16 for grasping a work of the work conveying device. A high resolution position detector is arranged for detection of movement in the directions of three axes of X, Y, and Z of a work conveying device in combination with an ordinary position detector. During measurement of the work by the sensor 36, the high resolution position detector is switched for use.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work transfer device for controlling a moving position of a numerically controlled machine tool by a numerical control device to carry in and out a work, and more particularly to a work transfer device in the vicinity of a work holding portion of the work transfer device. The present invention relates to a work transfer device provided with a contact sensor and performing various measurement and detection of a work using a control function of a numerical control device.

[0002]

2. Description of the Related Art Generally, a machining system for a machine tool is configured by appropriately combining a machine tool main body, a measuring device, a work transfer device, various monitoring devices, and these control devices. Regarding measurement detection for a work, it is necessary to first confirm whether or not there is a work to be conveyed, and if so, it is necessary to measure the shape and size of the work in order to identify whether or not the work can be conveyed . Further, a work phase check may be necessary for gripping the work. In recent years, there is a tendency for machining and production using machine tools to produce different kinds of workpieces in small lots and in many types, and more strict measurement detection is becoming increasingly important.

[0003] A conventional procedure of work measurement detection and transport will be described. 1. A detector is movably arranged in the stocker for material work to detect whether or not the material work exists. 2. Another measuring device is movably arranged in the stocker for material work to measure the shape and size of the material work. 3. If necessary, detect the phase of the workpiece. 4. If necessary, the material work is phase-positioned at a predetermined angular position by a phase determining device. 5. The opening amount of the gripper provided in the transfer device is determined, and the workpiece in the stocker is gripped and carried into the machine tool. 6. If necessary, the chuck of the machine tool is stopped at a predetermined angular position in accordance with the phase of the work. 7. The workpiece is transferred from the gripper of the transfer device to the machine tool chuck. 8. After the cutting, the dimensions of the finished product work are measured by a measuring instrument provided on a tool post or the like, the finished product is gripped by a gripper of a transfer device, and the finished product work is carried out.

Conventionally, a measuring instrument and a detector are provided in each section as described above, and each section apparatus is operated by a signal from each measuring instrument. This control was controlled by a central controller for the machine tool.

A case where a conventional control state using these various measuring instruments is applied to a lathe will be described with reference to a control relation diagram shown in FIG.

The central control device 100 for controlling the movement of each part of the lathe main body includes rotation of the main spindle of the lathe and control for stopping at a fixed position, X, Y and Z movement of the tool rest and tool selection control, Z movement of the tailstock and sleeve clamp control. In addition to door opening / closing control, coolant discharge control, chuck jaw opening / closing control, and measurement control of the finished product work, the following control was also performed in addition to the control of the lathe body. That is, X, Y, and Z movement control of the work transfer device 101, opening and closing control of the work gripper 102, and the work presence / absence detector 10 provided in the material work stocker 103.
4, operation control and measurement control of the work size measuring device 105,
Material device pallet 106 in material stocker 103
The rotation control was performed together.

[0007]

In the measurement and detection method described in the prior art, since each part is provided with a measuring instrument, it is necessary to drive each of these measuring instruments and to control the driving. Further, these controls have to communicate with a central controller for controlling the main body of the machine tool to perform integrated control by the central controller, which has a problem that both mechanisms and controls are complicated. In addition, there is a problem that the burden is large from an economical point of view and the burden at the work preparation stage is also increased.

[0008] The present invention has been made in view of such problems of the prior art, and the object thereof is to
A dedicated control device is provided for the work transfer device, and a measurement sensor is attached near the work gripper of the work transfer device.
This dedicated control device not only controls the work transfer, but also controls the movement of the sensor for the work measurement detection operation, thereby reducing the number of control mechanisms, reducing the number of control systems, and increasing reliability through direct detection. An object of the present invention is to provide a work transfer device with a contact sensor that can be used.

[0009]

According to a first aspect of the present invention, there is provided an apparatus according to the present invention, wherein a numerical controller is provided for conveying a work, and the numerical controller is mounted near a work holding portion by the numerical controller. The work is measured by the sensor.

According to the above-described apparatus, since the numerical controller is provided for transferring the work, the burden on the central controller for the machine tool can be reduced. In addition, since a sensor is mounted near the work gripper to perform work measurement, a sensor drive mechanism and a control device for this drive are not required for work measurement, and space for dedicated measurement means can be omitted. Done, and the price is lower. In addition, since the finished workpiece gripped by the spindle chuck is measured by a sensor attached near the workpiece gripper, there is no need to attach a measuring instrument to the tool mount tool mount on the lathe, and the Many tools can be attached.

According to a second aspect of the present invention, there is provided an apparatus for pivoting a work holding portion, wherein a contact of a sensor mounted near the work is directed in the direction of the work. According to the above-described device, the sensor is rotated by the turning motion of the work gripping portion, so that a turning device dedicated to the sensor is not required, and the structure is further simplified.

According to a third aspect of the present invention, there is provided a position detector having a high resolution for work measurement separately from a position detector for work transfer. According to the above-described apparatus, the two position detectors are switched between the time of transferring the work and the time of measuring the work, so that the work can be measured with high accuracy.

According to a fourth aspect of the present invention, there is provided an apparatus for detecting a position of a workpiece gripper, which measures the diameter of the workpiece when gripping the workpiece. According to the above-described apparatus, the work can be grasped and the work diameter can be measured at the same time, so that not only the structure is simplified, but also the non-machining time can be reduced.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic explanatory view when a loader as a work transfer device is used for a lathe.

A main spindle (not shown) is mounted on the headstock 2 of the lathe main body 1 so as to be able to position the rotation angle in the horizontal Z-axis direction, and a chuck 3 for gripping a work is attached to the front end of the main spindle. On the upper and lower two pairs of sliding surfaces 5A and 5B provided on the bed 4, two upper and lower carriages 6A and 6B are mounted so as to be movable and positioned in the Z-axis direction with the main shaft axis interposed therebetween. A tool post 8 is provided on sliding surfaces 7A and 7B in the X-axis direction provided on the upper surfaces of the carriages 6A and 6B, respectively.
A and 8B are mounted so as to move and position at right angles to the Z axis.

The frame 1 has a rectangular parallelepiped shape surrounding the entire lathe.
1 is provided, and a loader beam 13 extending in the X-axis direction while straddling the two upper beams 12 in the Z-axis direction of the frame body 11 is attached so as to be movable and positioned in the Z-axis direction. . The loader beam 13 has a rail 13a in the X-axis direction.
It is mounted so that it can be moved and positioned in the axial direction. A loader arm 15 is attached to the front end surface of the loader body 14 on the Z-axis tailstock side so as to be movable and positioned in the vertical Y-axis direction.
6 is mounted so as to be able to move and open and close in the Z-axis direction. The workpiece W is placed on each of a plurality of pallets 18 at the front left side of the lathe main body 1 on the worker side, and these pallets 18 are rotated in a horizontal plane to position a required pallet at a predetermined work take-out position. A stocker 17 for material work is provided.

FIG. 2 is an explanatory view showing the internal mechanism of the loader main body 14. As shown in FIG. A ball screw 20 is rotatably mounted on the loader main body 14 in the vertical Y-axis direction.
Is connected by a coupling 22 to a servomotor 21 with a position detector 21a attached to the upper surface of the device and is rotated. The ball screw nut 23 meshing with the ball screw 20 is fixed to the loader arm 15, and the servo motor 21 is rotated by a command from the numerical controller, and the loader arm 15 is controlled to move in the vertical Y-axis direction.

The servo motor 2 is provided on the loader body 14 side of the facing portion of the loader body 14 and the loader arm 15.
The scale unit 24-1 of the position detector 24 having a higher resolution than the position detector 21a attached to the loader arm 1, and the slider 24-2 is attached to the loader arm 15 side. When the position of the loader arm 15 in the Y-axis direction is detected, the above-described 2
The two position detectors 21a and 24 are switched and used. In each case, the Y of the loader arm 15 moved
The axial position is detected and transmitted to the numerical controller.

Although only the Y-axis direction has been described above, a position detector having a higher resolution is provided in addition to the work transfer position detector in the X-axis direction and the Z-axis direction. The position detector is switched and used during work measurement.

FIGS. 3 and 4 show a pair of gripper claws 16 provided at the tip of the loader arm 15 and the work detection sensor 3.
FIG. 6 is a schematic explanatory view showing a drive mechanism of No. 6;

The lower end of the loader arm 15 is bifurcated to form a support portion 15a between which the revolving body 25 is located.
Is sandwiched. The revolving unit 25 is pivoted 26 in the horizontal X-axis direction.
And the lower bifurcated support portion 1 of the loader arm 15
5a is pivotally supported in the YZ plane so as to be able to rotate and index. Further, a worm wheel 27 is provided integrally with the pivot 26. A servomotor 29 is attached to the loader arm 15 with the axis thereof in the Z-axis direction and the output shaft 28 facing downward. A worm 30 meshing with the worm wheel 27 is provided at a lower end of the output shaft 28.
5 rotates 90 degrees in the directions of arrows a and b in FIG.

The revolving unit 25 has a guide groove 25a in the X-axis direction.
And a pair of gripper claws 16 are slidably mounted in the guide groove 25a. A driving screw shaft 31 whose torsion directions are opposite to each other at the center in the X-axis direction in the guide groove 25a is pivotally supported on the revolving unit 25,
The pair of gripper claws 16 are screwed respectively. The drive screw shaft 31 is connected to an output shaft of a servo motor 32 attached to the revolving unit 25, and the pair of gripper claws 16 are simultaneously moved apart and approach by the same amount to open and close by driving of the servo motor 32.

A scale 33-1 of the position detector 33 is mounted in the X-axis direction near the base of the gripper claw 16 of the revolving unit 25. The scale 33-1 is attached to the base of each gripper claw 16 by a slider 33-2. The position of the gripper claw 16 is detected. Two contacts are attached to the pair of gripper claws 16 at an angle of 45 ° with respect to the up and down direction via an insulating material, and a signal is sent to the numerical controller when it comes into contact with the work.

At this time, the distance between the gripper claws 16 increases and decreases by √2Δd in accordance with the increase and decrease of the work diameter by Δd. Also, by aligning the axis of the pair of grippers 16 with the axis of the workpiece holding center axis, the workpiece measurement sensor 36
Are attached to the revolving superstructure 25. When the loader is positioned on the front surface of the chuck 3 of the lathe headstock 2, the tip contact of the sensor 36 is in a state of protruding toward the chuck 3 in the Z-axis direction.

FIG. 5 is a control relation diagram showing a control state of the present invention. A central control device 50 for controlling all the movements of the lathe main body portion, and a separate dedicated control device 5 for the loader
1 is provided. The transfer / measurement of the work is all controlled by the loader control device 51. That is, the loader X, Y, Z
Axis movement control, 90 ° turning movement control of the revolving unit 25, opening / closing control of the gripper claw 16 of the loader tip, measurement control of the work by the sensor 36 attached to the revolving unit 25, the stocker 1
The control for rotating the pallet 18 is performed. Then, information is exchanged between the control device 51 and the central control device 50, and the movement of each part of the lathe main body and the movement of each part of the loader are associated with each other as necessary.

Next, the movement of the loader portion controlled by the dedicated control device 51 for the loader will be described.

First, the revolving body 25 is rotated 90 ° in the direction of arrow A in FIG. 4 by the servomotor 29 to bring the gripper pawl 16 into a horizontal state. This turning causes the sensor 36 to move the contact vertically downward. The loader beam 13 is moved to the left in the Z-axis direction by using a work transport position detector, and the loader main body 14 is moved to the front in the X-axis direction.
6 is positioned above the material workpiece unloading position of the material stocker 17.

In the material stocker 17, a predetermined pallet 18
Is rotated in the horizontal plane to position the workpiece at a predetermined material removal position. The loader arm 15 is moved downward in the Y-axis direction by using the work-measuring high-resolution position detector 24 to detect whether or not the material work W exists on the pallet 18 positioned at the material work take-out position. The tip of the contact of the sensor 36 is brought into contact with the workpiece W. When the tip of the sensor 36 directly contacts the pallet 18 near the lower end of the loader arm 15, the pallet 18
It can be seen that there is no material work W above.

When the material work W is present on the pallet 18, the movement of the loader beam 13 in the Z-axis direction and the movement of the loader body 1 using a high-resolution position detector for work measurement are performed.
4, the sensor 36 is moved in the XZ plane by moving the sensor 36 in the XZ plane, and the tip of the contactor of the sensor 36 is brought into contact with three positions on the outer periphery of the workpiece W as shown in FIG. .

Also, a high-resolution position detector 2 for work measurement.
7 by moving the loader arm 15 in the Y-axis direction using FIG.
The height of the workpiece W and the step size of the workpiece W are obtained by moving the sensor 36 up and down in the Y-axis direction as shown in FIG.
If the material workpiece W is provided with a protrusion at a position deviated from the center, the sensor 36 is moved in the XZ direction to detect a deviation phase of the protrusion with respect to the reference position as shown in FIG.

The servo motor 32 is instructed to open a required amount of the gripper claw 16 based on the dimensions of the workpiece thus obtained. The position of the gripper claw 16 at this time is determined by the position detector 33. Then, in order to make the chuck 3 of the lathe body open the claws according to the size of the workpiece,
When the phase detection is performed, information is exchanged between the dedicated control device 51 and the central position control device 50 in order to cause the chuck 3 of the lathe main body to stop the angular position in accordance with the phase as necessary.

After measurement of the workpiece W on the pallet 18, a pair of the loader beam 13 is moved in the Z-axis direction, the loader body 14 is moved in the X-axis direction, and the loader arm 15 is moved in the Y-axis direction using the work transfer position detector. The material work W is inserted between the gripper claws 16, and the servo motor 32 is operated to grip the material work W with the gripper claws 16. The grip of the workpiece W is confirmed by sending contact signals from all four contacts 34 attached to the inner surfaces of the pair of gripper claws 16. At this time, it is assumed that the operator's front cover of the lathe is in an open state.

After the workpiece W is gripped by the gripper claw 16, the loader arm 15 is raised in the Y-axis direction using the work transfer position detector, the revolving unit 25 is turned 90 ° in the direction of arrow B in FIG. 4, and the Z-axis of the loader beam 13. The material workpiece W is moved by moving the loader body 14 to the right in the direction of FIG.
Are positioned on the same rotation line as the lathe chuck 3. At this time, the lathe chuck 3 opens the pawl by a predetermined amount, and if necessary, stops and waits with the chuck pawl indexed to a required angular position.

Then, the loader beam 13 is moved to the left in the Z-axis direction and stopped with the left end of the workpiece W inserted between the chuck claws. Next, the claws of the chuck 3 are closed to hold the workpiece W, and the gripper claws 16 are opened to complete the delivery of the workpiece W from the loader to the lathe. When the loader retreats to a position away from the lathe main body after the completion of the delivery of the workpiece W, the front cover of the lathe is closed and cutting of the workpiece W is started.

When the front cover of the lathe is opened again after the completion of the cutting process, the loader is fed into the lathe, and the loader is moved in the three axes of X, Y, and Z by using a high-resolution position detector for work measurement. Then, the dimensions of the finished work are measured by the sensor 36, and the measurement result is transmitted from the dedicated control device 51 to the central control device 50. After that, the loader grips the finished work using the gripper claws 16 using the work transfer position detector and transfers the finished work to a not-shown finished stocker.

The material work W is not limited to one kind. Even if different material works W are respectively mounted on the plurality of pallets 18 of the material stocker 17, the material work W is detected by the sensor 36. It is also possible to discriminate the type and call a machining program corresponding to each material work based on the discriminated information to perform each cutting process. In the above description, the sensor 3
Although 6 is provided on the revolving unit 25 of the gripper claw 16 which is the work gripping portion at the tip of the loader arm 15, the workpiece gripping portion and the sensor 36 can be replaced and attached to the tip of the loader arm 15.

[0037]

Since the present invention is constructed as described above, the following effects can be obtained. In the apparatus according to the first aspect of the present invention, since a dedicated control device is provided for the work transfer device, the control load on the central control device can be reduced.
In addition, since a work contact sensor is provided near the work holding portion to measure and detect the work, a sensor drive mechanism and a control device for this drive for work measurement are not required, and a space for dedicated measuring means is saved. I can do it. Also, the price is lower.

Further, since the finished work gripped by the spindle chuck is measured by a sensor provided in the vicinity of the workpiece gripping portion, it is not necessary to attach a measuring instrument to the tool mount tool mounting portion in the lathe, and the cutting tool is not required. More tools can be attached to the table.

In the apparatus according to the second aspect of the present invention, since the sensor is rotated by the swiveling motion of the work holding portion, a dedicated swiveling device is not required, and the structure is further simplified.

In the apparatus according to the third aspect of the present invention, a high-resolution position detector is used at the time of work measurement, so that work measurement can be performed with high accuracy.

The apparatus according to the fourth aspect of the present invention can measure the diameter and the like of a workpiece gripped by the gripper of the loader, and the measuring operation itself is performed simultaneously with the gripping operation. In addition, it leads to a reduction in non-machining time.

[Brief description of the drawings]

FIG. 1 is an overall schematic explanatory view of a work transfer device of the present invention.

FIG. 2 is a schematic explanatory view of a main part structure of a work transfer device.

FIG. 3 is a schematic explanatory view of a work gripping part.

FIG. 4 is an AA view of FIG. 3;

FIG. 5 is a diagram showing a control relationship according to the present invention.

FIG. 6 is a diagram illustrating a measurement state of a work diameter.

FIG. 7 is a diagram illustrating a measurement state of a work height and a step.

FIG. 8 is a diagram showing a state of phase detection of a work.

FIG. 9 is a diagram illustrating a control relationship according to the related art.

[Explanation of symbols]

 16 Gripper 20 Ball Screw 21 Servomotor 21a Position Detector 23 Ball Screw Nut 24 High Resolution Position Detector 36 Work Measurement Sensor

Claims (4)

[Claims] 1. A work transfer device for a machine tool having a drive mechanism and a position detector, and a moving position is controlled by a numerical control device, comprising: a work control device numerical control device;
Providing a work contact sensor attached near the work gripper, moving the contact of the sensor using the drive mechanism, and performing work measurement with the output of the position detector by the numerical controller. A work transfer device characterized by the following. 2. A turning mechanism for turning the workpiece gripping portion 90 ° between two positions, a horizontal position for gripping the workpiece and a vertical position for gripping the workpiece, and contacts in a direction in which the workpiece can be contacted by the pivoting motion. A workpiece contact sensor mounted in the vicinity of the work gripping portion by projecting a child so that the numerical control device allows the workpiece gripping portion to match the direction of the grip center axis with the axis of the workpiece. 2. The work transfer device according to claim 1, wherein a contact of the sensor is directed in a work direction by being rotated using the turning mechanism. 3. 3. A position detector having a high resolution for work measurement in addition to a work transfer position detector in the three-axis direction is provided, and the position detector is used for work transfer and work measurement. The work transfer device according to claim 1, wherein the work transfer device is used for switching. 4. A work transfer device for a machine tool having a drive mechanism and a position detector, and a moving position is controlled by a numerical control device, comprising: a work control device numerical control device;
A work gripping member driving mechanism for opening and closing the work gripping member under the control of the numerical control device for the work transfer device, and a position detector for detecting the position of the work gripping member are provided. The output of the position detector by the numerical control device is provided. A workpiece transfer device characterized in that workpiece measurement is performed by using