CN113165133A

CN113165133A - Workpiece holding determination system

Info

Publication number: CN113165133A
Application number: CN201880099648.5A
Authority: CN
Inventors: 柳崎淳
Original assignee: Fuji Corp
Current assignee: Fuji Corp
Priority date: 2018-11-27
Filing date: 2018-11-27
Publication date: 2021-07-23
Anticipated expiration: 2038-11-27
Also published as: JPWO2020110184A1; JP7058347B2; CN113165133B; WO2020110184A1

Abstract

A workpiece holding confirmation device for an automatic workpiece carrier using a laser measuring instrument, comprising: a processing machine that processes the workpiece held by the holding device in the processing chamber; an automatic workpiece carrier for transferring workpieces to and from the processing machine; a laser measuring device which is installed outside the processing chamber and projects laser light to the workpiece in the processing chamber which is gripped by the automatic workpiece conveyor from the gripping device; and a workpiece holding determination device for determining whether or not the automatic workpiece carrier has gripped the workpiece based on the measurement information of the laser measurement device.

Description

Workpiece holding determination system

Technical Field

The present invention relates to a workpiece gripping determination system that uses a laser measuring device to confirm transfer of a workpiece between a processing machine and an automatic workpiece carrier.

Background

When a workpiece is machined in a machine tool, the workpiece needs to be accurately gripped by a workpiece holding unit such as a spindle chuck in order to obtain a required high machining accuracy. Therefore, the machine tool is provided with a detection device that detects the air pressure when the workpiece is in position and determines the gripping state of the workpiece. In addition, patent document 1 below discloses a workpiece attachment determination mechanism that determines the state of a workpiece held by a spindle chuck by measurement with a touch sensor and a laser measurement device. Specifically, the touch sensor for measuring the end portion of the workpiece in the direction of the rotation axis is movably assembled in the direction parallel to the rotation axis of the spindle chuck, and the laser measuring device is provided at a position apart from the spindle chuck so that the laser beam is projected from the direction perpendicular to the rotation axis onto the outer periphery of the workpiece.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2000-135656

Disclosure of Invention

Problems to be solved by the invention

However, although the conventional example of patent document 1 checks the workpiece gripped by the spindle chuck of the machine tool, it is necessary to determine gripping of the workpiece when the workpiece is conveyed by the automatic workpiece conveyor. This is because it is necessary to confirm whether or not the exchange with the spindle chuck is appropriately performed, in other words, whether or not the machined workpiece is not transferred to the automatic workpiece carrier side and is not left in the machine tool. The judgment of the gripping of the workpiece by the automatic workpiece conveyor up to this point is performed outside the processing room. However, since the detection position is far from the spindle chuck, if the workpiece is not gripped, a time loss from the determination result to the next operation becomes large. On the other hand, a configuration in which a sensor is provided in the processing chamber is also conceivable as in patent document 1, but since the processing chamber is in an environment in which the coolant is splashed, there is a problem that the sensor is likely to malfunction.

In order to solve the above problems, the present invention aims to provide a workpiece gripping determination system in which a laser measurement device is installed outside a processing chamber.

Means for solving the problems

A workpiece grip determination system according to an aspect of the present invention includes: a processing machine that processes the workpiece held by the holding device in the processing chamber; an automatic workpiece carrier for transferring workpieces to and from the processing machine; a laser measuring device which is installed outside the processing chamber and projects laser light to the workpiece in the processing chamber which is gripped by the automatic workpiece conveyor from the gripping device; and a workpiece holding determination device for determining whether or not the automatic workpiece carrier has gripped the workpiece based on the measurement information of the laser measurement device.

Effects of the invention

According to the above configuration, the laser measuring device installed outside the processing chamber projects laser light to the workpiece gripped by the automatic workpiece carrier from the gripping device in the processing chamber, and thereby it is determined whether or not the automatic workpiece carrier grips the workpiece based on the measurement information of the laser measuring device.

Drawings

Fig. 1 is a side view showing an internal structure of a machine tool.

Fig. 2 is a side view showing a state when the automatic workpiece carrier moves.

Fig. 3 is a side view showing a state where the workpiece is transferred by the automatic workpiece conveyor.

Fig. 4 is a side view schematically showing a state when the workpiece of the automatic workpiece conveyor is taken out.

Fig. 5 is a side view schematically showing a state in the automatic workpiece carrier when detecting the gripping of a workpiece.

Fig. 6 is a simplified diagram of the cleaning device.

Detailed Description

Next, an embodiment of a workpiece gripping determination system according to the present invention will be described below with reference to the drawings. In the present embodiment, a description will be given of a workpiece gripping determination system in a case where a workpiece is transferred between a machine tool and an automatic workpiece carrier, by way of example. Fig. 1 is a side view showing an internal structure of a machine tool. The machine tool 1 is assembled to a movable bed 18 having wheels, and is movable in the front-rear direction along a guide rail 201 laid on the upper surface of the base 2. In the present embodiment, a direction parallel to the horizontal main axis of the main axis device 11 and a machine body front-rear direction are taken as a Z-axis direction, a vertical machine body up-down direction orthogonal to the Z-axis is taken as an X-axis direction, and a machine body width direction orthogonal to the Z-axis and the X-axis is taken as a Y-axis direction.

The machine tool 1 has a spindle device 11 mounted on a movable bed 18 and is configured to be capable of rotating a spindle chuck 12 that grips a workpiece W. The machine tool 1 includes a tool table 16 including a rotary tool such as an end mill or a drill or a cutting tool such as a tool, and is provided with a turret device 15 capable of rotationally indexing the tool table 16. The machine tool 1 is a 2-axis lathe including a Z-axis drive device 13 for moving the turret device 15 in the Z-axis direction and an X-axis drive device 14 for moving the turret device 15 in the X-axis direction. The Z-axis drive device 13 and the X-axis drive device 14 have a slidable Z-axis slider 131 or X-axis slider 141, and are configured to convert the rotational output of the servomotor into a linear motion by a ball screw mechanism and move the linear motion. A control device 5 for controlling the respective driving units such as the spindle device 11, the Z-axis driving device 13, the X-axis driving device 14, and the turret device 15 is mounted on the machine tool 1.

The machine tool 1 uses a coolant for lubrication of machining of the workpiece W and flushing of chips. The spent coolant is retained in the reservoir 21 in the base 2 together with the chips and the like of the workpiece W. The coolant in the storage tank 21 is circulated through the filter and sent to the coolant tank 22, and from there, the coolant is sent to the processing chamber 10 by the pump 23. In addition to the coolant pipe 24 connected to the pump 23 being connected to a cleaning nozzle for flushing the chips into the storage tank 21, a branched pipe is also connected to the turret device 15, and the coolant is also sprayed from the tool table 16 to the machining point of the workpiece W.

The machine tool 1 is provided with a front cover 4 that can be opened and closed at a front surface portion of the machine body, in addition to a machine body cover 3 that constitutes a processing chamber 10. The front cover 4 is a member forming the conveying space 20 when processing machines of the same cover shape or the like are arranged in the width direction, and as shown in fig. 2 and 3, an automatic workpiece conveyor 8 that transfers the workpiece W is incorporated therein. Fig. 2 and 3 are side views showing the relationship of the automatic workpiece carrier 8 with respect to the machine tool 1, and particularly, fig. 2 shows a state during movement, and fig. 3 shows a state of transferring workpieces.

The machine tool 1 has a narrow width and a long shape in the front-rear direction, and a machining chamber 10 is formed in the front part of the machine body shown in fig. 2 and 3. The automatic workpiece carrier 8 is configured to move the articulated robot 26 on the front side of the machine tool 1. In the machine tool 1, an automatic slide door 301 is provided in an opening formed in the machine body cover 3, and when the automatic workpiece carrier 8 is opened by the slide door 301, the articulated robot 26 enters the processing chamber 10 through the opening, and the workpiece W is transferred to and from the spindle chuck 12.

The automatic workpiece carrier 8 has an articulated robot 26 incorporated in a traveling device 25 configured to move a traveling base 36 in the Y-axis direction. The articulated robot 26 is configured such that the upper arm member 31 and the forearm member 32 change their configurations by driving the 1 st joint mechanism 33 and the 2 nd joint mechanism 34. Specifically, the posture can be changed to a moving posture in which the upper arm member 31 and the forearm member 32 are folded and erected as shown in fig. 2 and a working posture in which the forearm member is tilted and extended as shown in fig. 3. A robot hand 27 having a chuck mechanism is assembled to the distal end of the articulated robot 26, and can grip and release the workpiece W.

The workpiece transfer device 8 moves the articulated robot 26 by driving the traveling device 25 with respect to the machine tool 1 constituting a machining line together with other machining machines or the like, and delivers and receives the workpiece W as shown in fig. 5. Then, the machine tool 1 that has received the workpiece W selects a tool of the tool table 16 by the rotational indexing of the turret device 15, and moves the tool to a predetermined position in the Z-axis direction and the X-axis direction by driving the Z-axis drive device 13 and the X-axis drive device 14. In the spindle device 11, the tool is brought into contact with the rotating workpiece W while rotating the spindle head 12, thereby performing cutting or the like. Thereafter, the processed workpiece W is removed from the spindle chuck 12 by the automatic workpiece conveyor 8 and conveyed to a subsequent processing machine or the like.

In the machine tool 1 and the automatic workpiece carrier 8, in order to appropriately perform automatic machining of the workpiece W, a gripping determination of the workpiece W by the spindle chuck 12 and the robot hand 27 is performed. A machine tool 1 incorporates a seating determination device for determining the seating of the spindle chuck 12. Although not shown in detail, the seating determination device is configured to send compressed air to a detection hole formed in the spindle chuck 12 through an air flow path, and determine the state in which the detection hole is blocked by the workpiece W, in other words, the seating state of the workpiece W, based on the back pressure in the air flow path. With this seating determination device, it can be confirmed that the spindle chuck 12 correctly grips the workpiece W, and precision machining of the workpiece W can be performed.

On the other hand, the automatic workpiece carrier 8 confirms that the machined workpiece W is reliably received from the spindle chuck 12. This is because the robot hand 27 may not grip the workpiece W and may hold the workpiece W in the spindle chuck 12. Heretofore, a sensor is mounted in the conveyance space 20, and the robot hand 27 determines the gripping of a workpiece at a detection point set outside the processing chamber 10. However, since the distance from the robot hand 27 to the transfer space 20 after exiting the processing chamber 10 is long, if an error occurs in gripping by the robot hand 27, the time required for the subsequent operation transition, such as a retry operation for transferring the workpiece or a stop of driving the machine tool 1, becomes long.

Here, in the present embodiment, a workpiece gripping determination system is configured to be able to check whether or not the workpiece W gripped by the robot hand 27 is present in the processing chamber 10. In this case, in order to perform detection in the processing chamber 10, for example, a detection sensor may be provided in the processing chamber 10. However, since the coolant splashes in the processing chamber 10 during processing, the detection sensor may be affected by the coolant, causing a failure or the like. In the present embodiment, in consideration of this point, the laser sensor 6 is mounted via a bracket in the conveying space 20 outside the processing chamber 10, which is the position shown in fig. 3, particularly, in the opening of the body cover 3 provided with the automatic slide door 301.

Here, fig. 4 and 5 are side views showing the automatic workpiece carrier 8 in a simplified manner, fig. 4 shows a state when the workpiece is taken out, and fig. 5 shows a state when the workpiece is gripped and detected. The laser sensor 6 measures the time until the laser beam 601 reflecting the workpiece W is received, for example, using a time measurement type sensor, and determines the presence or absence of the workpiece W from the detected time. The laser sensor 6 is provided with a detection point P for detecting the workpiece W gripped by the robot hand 27, and the mounting angle is determined so that the laser beam 601 is projected obliquely from the conveyance space 20 side at the installation position into the processing chamber 10. The closer the detection point P is to the spindle chuck 12, the better it is, but in order to avoid erroneous detection, the detection point P is set at a position separated from the spindle chuck 12 by a predetermined distance L.

This is because, if the position is too close to the spindle chuck 12, there is a possibility that a difference between normal detection in which the laser beam 601 is reflected off the workpiece W held by the robot hand 27 and detection in a case where the workpiece W is not held and the laser beam 601 is reflected off the spindle chuck 12 or the like cannot be distinguished. On the other hand, if the detection point P is far from the collet 12, the time required to confirm an error in gripping the workpiece W is disadvantageously shortened. Here, a position at least closer to the spindle chuck 12 than a position of the slide door 301 (a position of the boundary line 30 shown in fig. 5) where the workpiece W enters and exits from the processing chamber 10 is set as the detection point P. From this point of view, in the present embodiment, the detection point P in the machine tool 1 is preferably located at a position separated from the spindle chuck 12 by about 100 mm.

The coolant is supplied into the processing chamber 10 during processing, and the coolant is sprayed particularly in the vicinity of a detection point P near a processing point onto the rotating workpiece W to be vigorously splashed. Therefore, the coolant may be attached to the surface of the workpiece W after machining as water droplets, and the water droplets on the workpiece surface may affect the reflection of the laser beam 601. Further, the coolant splashed during the machining of the workpiece is atomized into water after the machining and floats in the machining chamber 10. When the laser beam 601 is projected in such an environment, it may be reflected by the coolant in the form of mist and still be affected. Therefore, the machine tool 1 according to the present embodiment is configured to eliminate water droplets and mist of the coolant that affect the workpiece gripping detection.

Specifically, the cleaning device 17 incorporated in the turret device 15 is used. Fig. 6 is a simplified diagram of the structure of the cleaning device 17. In the turret device 15, a plurality of tools 49 are mounted on the tool table 16, and the tool 49 for performing machining can be selected by rotational indexing. In the turret device 15, a device main body 151 is fixed to the Z-axis slider 131, and the tool table 16 is assembled to the device main body 151 via a turning mechanism. The turret device 15 is provided with an air flow path 41 that communicates from the device main body 151 to the tool post 16.

The tool table 16 has a polygonal shape, and a tool block 48 integrated with a tool 49 is attachable to and detachable from each side. The tool table 16 is configured such that a nozzle block 42 provided with an air nozzle 44 can be attached and detached in addition to the tool block 48, and an air flow path 43 communicating with the air flow path 41 on the apparatus main body 151 side is formed therein. Air piping 46 extending from the compressor 45 is connected to the

air flow paths

41 and 43, and an open/close solenoid valve 47 is provided in the air piping 46. Therefore, the cleaning device 17 constitutes an air blower that passes compressed air from an air compressor 45 through the

air flow paths

41, 43 and ejects the air from the air nozzle 44.

The automatic workpiece conveyor 8 has a control device 28 that controls the driving of the traveling device 25, the articulated robot 26, and the robot hand 27, and a conveying program for delivering and receiving the workpiece W to and from the machine tool 1 and the like is stored in the memory. In particular, in the present embodiment, a workpiece gripping determination program is incorporated in the conveyance program. On the other hand, the machine tool 1 constitutes a processing line together with other processing machines and the like, and each control device is connected to the control device 28 of the automatic workpiece conveyor 8, and a LAN is constructed in the processing line. The control device 5 of the machine tool 1 stores a support program for operating the cleaning device 17 in accordance with the workpiece gripping determination process of the automatic workpiece carrier 8.

Here, as shown in fig. 4, the automatic workpiece conveyor 8 that conveys the processed workpiece W to the next step enters the processing chamber 10 through the opening of the slide door 301. The articulated robot 26 extends from the transfer space 20 to the depth of the processing chamber 10 while changing its posture, and the workpiece W is gripped between the spindle chuck 12 and the robot hand 27 at the tip end. Thereafter, the articulated robot 26 is folded, and the workpiece W is checked to be gripped at the detection point P during the conveyance to the outside of the processing chamber 10.

The robot hand 27 gripping the workpiece W performs 90-degree rotation so as to move the workpiece W upward to the detection point P. When the workpiece W moves to the detection point P, the articulated robot 26 stops for about 1 second, and the laser beam 601 is projected from the laser sensor 6 at this point, and it is determined whether or not the workpiece W is gripped by the robot hand 27. When the robot hand 27 holds the workpiece W, the presence of the workpiece is determined by receiving the laser beam 601 that has reflected the workpiece W. On the other hand, in the case where the robot hand 27 is not holding the workpiece W, the laser light 601 is caused to pass through the robot hand 27. In this case, since the laser beam 601 is reflected by another object and received, the detection time is different, and a workpiece gripping error is determined.

In such detection, while the workpiece W after machining is moved from the spindle chuck 12 to the detection point P, a supporting operation of blowing off water droplets adhering to the workpiece W and mist around the workpiece W is performed by driving the cleaning device 17 or the like. In the supporting operation, the direction of the air to be ejected is adjusted by the rotational displacement of the turret device 15 with respect to the air nozzle 44 of the cleaning device 17, and the position of the air to be ejected into the processing chamber 10 is adjusted by the driving of the Z-axis driving device 13 and the X-axis driving device 14. Therefore, in the workpiece holding detection, as shown in fig. 5, air is ejected from the air nozzle 44, and water droplets of the workpiece W and surrounding mist are blown away by the air, whereby the laser beam 601 is projected and received without being affected by the coolant.

According to such a workpiece holding determination, if an erroneous determination occurs that the robot hand 27 does not hold the workpiece W, the operator is required to remove the workpiece W from the spindle chuck 12 by manual operation. Therefore, the articulated robot 26 retreats to a predetermined position in the conveying space 20 and performs drive stop control together with the machine tool 1. When an erroneous determination has occurred, the robot hand 27 may again perform the detection of the gripping of the workpiece W by the robot hand 27 and the replacement of the gripping of the workpiece W with respect to the spindle chuck 12 by the retry operation. On the other hand, when it can be confirmed that the robot hand 27 grips the workpiece W, the workpiece W is conveyed to the next processing machine or the like.

Therefore, in the present embodiment, since the position close to the spindle chuck 12 is used as the detection point P, the detection result can be obtained in a short time, and the time loss until the next operation is shifted can be reduced compared to the conventional one. In addition, since the laser sensor 6 is mounted outside the processing chamber 10, it is not adversely affected by the coolant. In particular, since the laser sensor 6 is mounted at the upper portion of the opening of the body cover 3 where the slide door 301 is provided, the operation of the articulated robot 26 is not hindered. Further, by performing the operation of supporting the work using the blower, the accuracy of the detection of the gripping of the workpiece using the laser sensor 6 is improved.

However, in the present embodiment, the workpiece gripping detection is performed while keeping the detection point P constant. Therefore, the workpiece W needs to be stopped for about 1 second. Therefore, it is also considered that a driving mechanism for adjusting the projection angle of the laser beam 601 is added as a mounting tool for the laser sensor 6, and the projection position is changed so as to match the previously known movement position of the workpiece W. The laser beam 601 is projected over a constant movement range with respect to the workpiece W that moves from the spindle chuck 12 to the robot hand 27, and the time until the workpiece W receives light that changes with the movement is calculated and determined. This makes it possible to determine the gripping of the workpiece W without stopping.

While one embodiment of the present invention has been described above, the present invention is not limited to the above, and various modifications can be made without departing from the scope of the invention.

For example, in the above embodiment, the position moved by about 100mm from the spindle chuck 12 is used as the detection point P, and the workpiece W is stopped for about 1 second to perform sensing detection.

Further, the laser sensor 6 that measures the time until the laser beam 601 receives light is exemplified, but may be configured to measure a change in the position at which the laser beam is condensed on the detection element.

Further, the cleaning device 17 incorporated in the turret device 15 is used to perform the supporting operation, but a cleaning device for ejecting air to the workpiece W at the detection point P in the processing chamber 10 may be used. Further, a mist collector that collects mist of the coolant in the machining chamber 10 may be incorporated into the machine tool 1.

Description of the reference numerals

1 … automatic workpiece transporter with 5 … controller 6 … laser sensor 8 … for machine tool

10 … processing chamber 11 … spindle assembly 12 … spindle chuck 15 … turret assembly 17 …

The sweeping device 20 … carries the space 26 … multi-joint robot 27 … robot hand 28 … control

Device 601 … laser

Claims

1. A workpiece hold determination system includes:

a processing machine that processes the workpiece held by the holding device in the processing chamber;

an automatic workpiece carrier for transferring and receiving workpieces to and from the processing machine;

a laser measuring device which is installed outside the processing chamber and projects laser light to the workpiece in the processing chamber grasped by the automatic workpiece conveyor from the grasping device; and

and a workpiece gripping determination device for determining whether or not the automatic workpiece carrier has gripped the workpiece, based on the measurement information of the laser measurement device.

2. The workpiece hold determination system according to claim 1,

the automatic workpiece carrier temporarily stops the movement of the workpiece at a measurement position where the laser beam is projected from the laser measuring device.

3. The workpiece hold determination system according to claim 2,

the processing machine has a cleaning device that cleans, with air, the workpiece temporarily stopped at the measurement position.

4. The workpiece hold judging system according to any one of claims 1 to 3,

the automatic workpiece carrier has an air blower for blowing air around a measurement position where the laser is projected from the laser measurement device.

5. The workpiece hold judging system according to any one of claims 1 to 4,

the laser measuring device takes a position closer to the gripping device than an opening of the processing chamber into and out of which the workpiece is to be taken as a measuring position for projecting laser onto the workpiece.