WO2020250798A1

WO2020250798A1 - Removal system and control device

Info

Publication number: WO2020250798A1
Application number: PCT/JP2020/022116
Authority: WO
Inventors: 民和西宮
Original assignee: 株式会社北川鉄工所
Priority date: 2019-06-10
Filing date: 2020-06-04
Publication date: 2020-12-17
Also published as: JPWO2020250798A1; JP7455122B2; TWI839528B; TW202108326A

Abstract

[Problem] To provide a removal system and a control device that can remove foreign matter adhering to a close-contact surface of a jig. [Solution] According to one aspect of the present invention, provided is a removal system for removing foreign matter adhering to a machine tool, the removal system comprising a surface sensor, a foreign matter removal device, and a control device. The surface sensor is configured to be able to detect a surface state of a close-contact surface in the surface of a jig of the machine tool. Here, the close-contact surface is at least one of a surface interposed between members constituting the jig and a surface that contacts a workpiece grasped by the jig. The foreign matter removal device is configured to be able to remove foreign matter from the close-contact surface, and the control device is provided with a surface state storage unit, a foreign matter detection unit, and an operation instruction unit. The surface state storage unit stores a surface state of the close-contact surface being in a state in which foreign matter does not adhere. The foreign matter detection unit is configured to be able to detect foreign matter adhering to the close-contact surface on the basis of a comparison between a surface state of the close-contact surface detected by the surface sensor and the surface state stored in the surface state storage unit. The operation instruction unit is configured to be able to send an operation instruction to the foreign matter removal device when the foreign matter detection unit detects foreign matter.

Description

Removal system and control device

The present invention relates to a removal system and a control device.

In machine tools such as lathes and machining centers, normal operation may not be possible if chips are attached to the gripping surface that grips the work, or if chips are entangled in the chuck or tool.

Therefore, a technique for preventing chips from entering a predetermined space (see, for example, Patent Document 1) and a technique for removing attached chips (see, for example, Patent Document 2) have been proposed.

Japanese Unexamined Patent Publication No. 2001-277012

Japanese Unexamined Patent Publication No. 8-150537

By the way, even in jigs of machine tools, for example, chucks, NC rotary tables, vices, stationary chucks, pallet jigs, etc., if foreign matter such as chips adheres to the contact surface between the members constituting them, Poor gripping of the work may occur, and the machining accuracy of the work is lowered. Similarly, when foreign matter such as chips adheres to the contact surface with the work when gripping the work, the work may be poorly gripped and the machining accuracy of the work may be lowered. In addition, the adhesion of foreign matter may cause damage to the work and the jig itself.

For this reason, it is important to remove foreign matter even on the contact surface of the jig.

However, the technique described in Patent Document 1 cannot completely prevent chips from entering a predetermined space. For this reason, when this technique is used, there is a possibility that foreign matter may adhere to the surface that becomes the close contact surface to which the members are attached or replaced or the work is gripped. is there.

Further, in the technique described in Patent Document 2, it is difficult to remove small foreign substances because the chips are grasped and removed by the chip removing hand.

Further, in the technique described in Patent Document 2, since chips are detected by physically pushing the sensor with chips, it is difficult to detect small foreign substances. For example, the contact surface of the jig. When serrations are formed in the valley, it is almost impossible to detect foreign matter in the valley.

In view of the above circumstances, the present invention has decided to provide a removal system and a control device capable of removing foreign matter adhering to the contact surface of the jig.

According to one aspect of the present invention, the removal system for removing foreign matter adhering to a machine tool includes a surface sensor, a foreign matter removing device, and a control device, and the surface sensor is a jig of the machine tool. The surface state of the close contact surface is detectable, and the close contact surface is at least a surface between members constituting the jig and a surface in contact with the work gripped by the jig. On the other hand, the foreign matter removing device is configured to be able to remove foreign matter from the close contact surface, and the control device includes a surface state storage unit, a foreign matter detection unit, and an operation instruction unit, and the surface state storage unit. Stores the surface state of the contact surface in a state where no foreign matter is attached, and the foreign matter detection unit stores the surface state of the contact surface detected by the surface sensor and the surface state storage unit. Based on the comparison with the surface state, the foreign matter adhering to the close contact surface can be detected, and the operation instructing unit refers to the foreign matter removing device when the foreign matter detecting unit detects the foreign matter. A removal system configured to be able to send operation instructions is provided.

According to one aspect of the present invention, foreign matter adhering to the contact surface is detected based on the comparison between the surface state of the contact surface detected by the surface sensor and the surface state stored in the surface state storage unit. .. As a result, it is possible to detect foreign matter such as relatively small chips, and it is possible to detect foreign matter even if there are markings or scratches on the contact surface.

It is a block diagram which shows the functional structure of the removal system 1. It is a perspective view which shows the appearance of a chuck. It is a perspective view which shows the appearance of the master jaw 72. It is a perspective view which shows the appearance of the top jaw 73. It is a figure which showed the example of the image of the surface state of the contact surface in the state where foreign matter is not attached. It is a figure which showed the example of the image of the surface state of the contact surface at the time of detecting a foreign substance. It is a figure which showed the example of the image which shows the difference between the image shown in FIG. 5 and the image shown in FIG. It is an activity diagram which shows the operation flow of the removal system 1.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The various features shown in the embodiments shown below can be combined with each other.

By the way, the program for realizing the software appearing in the present embodiment may be provided as a non-temporary recording medium readable by a computer, may be provided as a downloadable form from an external server, or may be provided. It may be provided so that the program is started by an external computer and the function is realized by the client terminal (so-called cloud computing).

Further, in the present embodiment, the "part" may include, for example, a combination of hardware resources implemented by a circuit in a broad sense and information processing of software that can be concretely realized by these hardware resources. .. In addition, various information is handled in this embodiment, and these information are, for example, physical values of signal values representing voltage and current, and signal values as a bit aggregate of a binary number composed of 0 or 1. It is represented by high-low or quantum superposition (so-called qubit), and communication / calculation can be executed on a circuit in a broad sense.

Further, a circuit in a broad sense is a circuit realized by at least appropriately combining a circuit (Circuit), circuits (Circuitry), a processor (Processor), a memory (Memory), and the like. That is, an integrated circuit for a specific application (Application Special Integrated Circuit: ASIC), a programmable logic device (for example, a simple programmable logic device (Simple Programmable Logical Device: SPLD), a composite programmable logic device (Complex Program), a compound Program It includes a programmable gate array (Field Programmable Gate Array: FPGA) and the like.

1. 1. Configuration Example First, the configuration of the removal system will be described. FIG. 1 is a block diagram showing a functional configuration of the removal system 1.

As shown in the figure, the removal system 1 is configured to include a control device 2, a robot arm 3, a surface sensor 4, and a foreign matter removing device 5, and is a system for removing foreign matter adhering to the machine tool 6.

The control device 2 controls the robot arm 3, the surface sensor 4, and the foreign matter removing device 5, and includes a surface state storage unit 21, a foreign matter detecting unit 22, and an operation indicating unit 23.

The robot arm 3 is a robot capable of performing various operations on the machine tool 6, and an end effector can be attached to and detached from the tip of the robot arm 3, and a surface sensor 4 and foreign matter can be placed on the outer periphery near the tip of the robot arm 3. The removal device 5 can be attached. Further, the removal system 1 may include a plurality of robot arms 3 and use both the robot arm 3 equipped with the surface sensor 4 and the robot arm 3 equipped with the foreign matter removing device 5. The surface sensor 4 and the foreign matter removing device 5 may be attached to and detached from the robot arm 3 as end effectors.

The surface sensor 4 is configured to be able to detect the surface state of the contact surface of the members constituting the jig of the machine tool 6. Specifically, the surface sensor 4 is realized by a camera, a displacement meter, or the like. As the displacement meter, various types such as optical type, eddy current type, ultrasonic type, and laser type can be used as long as they are non-contact type. For example, a two-dimensional laser displacement meter or a three-dimensional displacement meter can be used. A laser displacement meter can be used. Further, the surface sensor 4 may be arranged at the tip or the outer circumference of the robot arm 3 as long as it can detect the surface state of the contact surface of the member constituting the jig of the machine tool 6, and the processing of the machine tool 6 may be performed. It may be arranged in the area. When arranging the surface sensors 4 in this processing area, a plurality of surface sensors 4 may be used. The jig and its contact surface will be described later.

The foreign matter removing device 5 removes foreign matter from the close contact surface of the members constituting the jig of the machine tool 6, and has a rotating brush, a brush, a gripper, an air blow, a liquid ejector, an aspirator, and the like. These may be simple substances or a combination thereof as appropriate. It is also possible to use an integrated combination such as an air blow with a built-in gripper.

Further, the removal system 1 may be provided with a plurality of foreign matter removing devices 5, and may be appropriately used, such as one for removing relatively large foreign matter and one for removing relatively small foreign matter.

The surface state storage unit 21 stores the surface state of the close contact surface of the members constituting the jig of the machine tool 6 in a state where no foreign matter is attached. Specifically, the result of detecting the surface state of the contact surface by the surface sensor 4 is stored when the jig is newly used or immediately after the inspection is completed. When the surface sensor 4 is a camera, the surface state storage unit 21 stores an image in a state where no foreign matter is attached.

Further, when the surface sensor 4 is a two-dimensional laser displacement meter, the surface state storage unit 21 operates the robot arm 3 so that the two-dimensional laser displacement meter can measure the entire contact surface, and measures the foreign matter. A contour diagram image of the surface state of the contact surface in the non-adhered state is stored. In addition, instead of the contour diagram image, the numerical data measured by the two-dimensional laser displacement meter may be stored.

When the surface sensor 4 is a three-dimensional laser scanner, the surface state storage unit 21 stores a two-dimensional contour diagram as an image or stores numerical data.

The foreign matter detecting unit 22 adheres based on the comparison between the surface state of the contact surface of the member constituting the jig of the machine tool 6 detected by the surface sensor 4 and the surface state stored in the surface state storage unit 21. Detects foreign matter adhering to the surface. Specifically, the foreign matter detecting unit 22 uses the surface state image stored in the surface state storage unit 21 as a background image, the surface state image detected by the surface sensor 4 as a foreground image, and removes foreign matter by background subtraction. To detect.

When the surface sensor 4 is a camera, the foreign matter detecting unit 22 detects foreign matter adhering to the close contact surface based on the difference between the image captured by the camera and the image stored in the surface state storage unit 21. To do. Further, when the surface sensor 4 is a two-dimensional laser displacement meter, the foreign matter detection unit 22 operates the robot arm 3 so that the two-dimensional laser displacement meter can measure the entire contact surface, and measures the measurement result. A foreign substance adhering to the contact surface is detected based on the difference between the contour-figured image and the image stored in the surface state storage unit 21.

When the foreign matter detecting unit 22 detects a foreign matter, the operation instruction unit 23 sends an operation instruction to the robot arm 3 and the foreign matter removing device 5. The operation instruction sent by the operation instruction unit 23 to the robot arm 3 includes position information indicating the position of the foreign matter detected by the foreign matter detection unit 22, and the robot arm 3 causes the foreign matter removing device 5 to use the foreign matter removal device 5 based on the position information. It is a movement instruction to move to the vicinity. The operation instruction sent by the operation instruction unit 23 to the foreign matter removing device 5 is a driving instruction for driving the foreign matter removing device 5. For example, if the foreign matter removing device 5 is composed of a rotating brush, its rotation thereof. It is for driving the brush.

The operation instruction unit 23 may communicate with the machine tool 6 to interlock with the machine tool 6, but at least the machine tool 6 is in an operating state of cutting or is stopped. It is desirable to be able to confirm whether it is in a state.

The operation instruction to the foreign matter removing device 5 may be notified from the operation instruction unit 23 to the foreign matter removing device 5 via the robot arm 3 on which the foreign matter removing device 5 is mounted.

When a plurality of foreign matter removing devices 5 are used, the operation instruction unit 23 selects one of the plurality of foreign matter removing devices 5 based on at least one of the position and size of the foreign matter detected by the foreign matter detecting unit 22. , Sends a mounting instruction to the robot arm 3 instructing the mounting of the selected foreign matter removing device. The selection based on the position of the foreign matter is performed, for example, when serrations are formed on the contact surface, and when a foreign matter suitable for removing the foreign matter from the serrations is used.

Further, when the surface sensor 4 is attached to the robot arm 3, the operation instruction unit 23 sends an operation instruction for detecting the surface state of the contact surface to the robot arm 3.

2. 2. Adhesion surface Next, the adhesion surface to which the removal system 1 removes foreign matter will be described. The close contact surface is both a surface where the member constituting the jig and the member are in contact with each other and a surface where the member and the work are in contact with each other. Examples of the jig include a chuck, an NC rotary table, a vise, a stationary chuck, a pallet jig, and the like. Here, the contact surface will be described by taking the chuck as an example. Although the description other than the chuck is omitted, jigs other than the chuck are also subject to the removal system 1 for removing foreign matter.

FIG. 2 is a perspective view showing the appearance of the chuck. As shown in the figure, the chuck 7 includes a body 71, a master jaw 72, and a top jaw 73. Each of the body 71, the master jaw 72, and the top jaw 73 corresponds to a member constituting the jig.

Next, the contact surface will be explained. FIG. 3 is a perspective view showing the appearance of the master jaw 72. Further, FIG. 4 is a perspective view showing the appearance of the top jaw 73. As shown in FIG. 3, the master jaw 72 has serrations 721 and grooves 722. Further, as shown in FIG. 4, the top jaw 73 has serrations 731.

Both the serration 721 and the serration 731 are in close contact with each other, and when the top jaw 73 is attached to the master jaw 72, the serration 721 has a peak portion and the serration 731 has a valley portion so as to mesh with each other.

The groove 722 is also a close contact surface. The groove 722 is a portion into which a T-nut, which is a member (not shown), can be inserted, and is an inverted T-shaped groove.

Also, when grasping the work with the top jaw 73, a locator (not shown) is attached to position the work. The surface in contact between the locator and the work is also a close contact surface, and the surface in contact with the top jaw 73 and the work is also a close contact surface.

3. 3. Image Next, an image of the surface state detected by the surface sensor 4 will be described. FIG. 5 is a diagram showing an example of an image of the surface state of the close contact surface in a state where no foreign matter is attached. Further, FIG. 6 is a diagram showing an example of an image of the surface state of the contact surface when detecting a foreign substance.

Both the image shown in FIG. 5 and the image shown in FIG. 6 correspond to images of serrations 721 taken from the front when the surface sensor 4 is a camera. Further, when the surface sensor 4 is a two-dimensional laser displacement meter, it corresponds to a contour diagram when the serration 731 is measured from the front.

The contour diagram is, for example, created by the foreign matter detection unit 22, and for each resolution measured by the two-dimensional laser displacement meter, pixels showing gradations according to the measured distance are generated, and a set of the pixels is generated. It is an image.

The foreign matter detecting unit 22 extracts background subtraction using the image shown in FIG. 5 as a background image and the image shown in FIG. 6 as a foreground image. At this time, appropriate image processing and the like are performed on each image, but description of these details will be omitted.

FIG. 7 is a diagram showing an example of an image showing the difference between the image shown in FIG. 5 and the image shown in FIG. The image shown in the figure is a binarization of the difference between the image shown in FIG. 5 and the image shown in FIG. 6 based on a predetermined threshold value, and shows a foreign substance such as chips. It is preferable to appropriately adjust such a threshold value according to the dynamic range and the like of the surface sensor 4 to be used. Further, the threshold value may be adjusted so as not to detect water droplets of cutting water but to detect chips. If necessary, the algorithm may be devised so as to use information on the color and shape of the foreign matter.

4. Operation Next, the operation of the removal system 1 will be described. FIG. 8 is an activity diagram showing an operation flow of the removal system 1. Here, it is assumed that the surface sensor 4 is mounted on the outer peripheral surface near the tip of the robot arm 3.

When the removal system 1 needs to replace the members constituting the jig, the robot arm 3 first removes the target member (A101).

Subsequently, the robot arm 3 moves the surface sensor 4 to the vicinity of the contact surface of the member removed in A101, and the surface sensor 4 detects the surface state of the contact surface (A102).

Then, the foreign matter detection unit 22 extracts background subtraction based on the image stored in the surface state storage unit 21 and the image detected by the surface sensor 4 (A103).

As a result, if no foreign matter is detected, the robot arm 3 attaches the member to be replaced (A104).

On the other hand, when a foreign matter is detected, the robot arm 3 attaches a foreign matter removing device 5 to its tip (A105).

Subsequently, the robot arm 3 moves the foreign matter removing device 5 to the vicinity of the contact surface of the member removed in A101 to try to remove the foreign matter (A106).

Next, the robot arm 3 moves the surface sensor 4 to the vicinity of the contact surface of the member removed in A101, and the surface sensor 4 detects the surface state of the contact surface (A107).

Then, the foreign matter detection unit 22 extracts background subtraction based on the image stored in the surface state storage unit 21 and the image detected by the surface sensor 4 (A108).

As a result, if no foreign matter is detected, the robot arm 3 removes the foreign matter removing device 5 (A109) and attaches the member to be replaced (A104).

Further, when foreign matter is detected as a result of extracting the background subtraction of A108, if the number of trials for removing foreign matter is less than a predetermined number, the foreign matter removing device 5 is moved to the vicinity of the contact surface of the member removed by A101 again. And try to remove the foreign matter (A106).

The foreign matter of A106 is removed by a predetermined number of trials, and if the foreign matter cannot be removed during that period, the removal system 1 stops the operation and issues a warning or the like.

When using a plurality of foreign matter removing devices 5, when the foreign matter removing trial of A108 is repeated a plurality of times, a different foreign matter removing device 5 may be used for each foreign matter removing trial.

5. Others Finally, although the embodiments according to the present invention have been described, these are presented as examples and are not intended to limit the scope of the invention. The novel embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. The embodiment and its modifications are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and the equivalent scope thereof.

The present invention may be provided in each of the following aspects.
In the removal system, the surface sensor is a camera, the surface state storage unit stores an image of the close contact surface in a state where no foreign matter is attached, and the foreign matter detection unit is an image captured by the camera. A removal system that detects foreign matter adhering to the close contact surface based on the difference between the image and the image stored in the surface state storage unit.
In the removal system, the surface sensor is a displacement meter, and the surface state storage unit stores a contoured image of the surface state of the contact surface in a state where no foreign matter is attached, which is measured by the displacement meter. Then, the foreign matter detecting unit detects the foreign matter adhering to the close contact surface based on the difference between the contour diagram of the measurement result by the displacement meter and the image stored in the surface state storage unit. Removal system.
In the removal system, the foreign matter removing device is attached to a robot arm that performs a predetermined operation on the machine tool, and the operation instruction unit is a position of a foreign matter detected by the foreign matter detecting unit with respect to the robot arm. A removal system configured to be able to send movement instructions based on location information indicating.
In the removal system, the surface sensor is a removal system mounted on the robot arm.
The removal system includes a plurality of the foreign matter removing devices, and the operation indicating unit selects one of the foreign matter removing devices based on at least one of the position and size of the foreign matter detected by the foreign matter detecting unit. A removal system that sends a mounting instruction to the robot arm to instruct mounting of the selected foreign matter removing device.
A control device for a foreign matter removing device for removing foreign matter adhering to a machine tool, which includes a surface state storage unit, a foreign matter detection unit, and an operation instruction unit, and the surface state storage unit is a jig of the machine tool. The surface state of the contact surface detected by the surface sensor in a state where no foreign matter adheres to the contact surface that is in close contact with at least one of the member constituting the jig and the work gripped by the jig. The foreign matter detection unit adheres to the contact surface based on the comparison between the surface state of the contact surface detected by the surface sensor and the surface state stored in the surface state storage unit. A control device configured to be able to detect a foreign matter, and the operation indicating unit is configured to be able to send an operation instruction to the foreign matter removing device when the foreign matter detecting unit detects a foreign matter.
In the control device, the foreign matter removing device is attached to a robot arm that performs a predetermined work on the machine tool, and the operation instruction unit is a position of a foreign matter detected by the foreign matter detecting unit with respect to the robot arm. A control device configured to be able to send a movement instruction based on the position information indicating.
In the control device, the surface sensor is a control device mounted on the robot arm.
Of course, this is not the case.

1: Removal system 2: Control device 21: Surface state storage unit 22: Foreign matter detection unit 23: Operation instruction unit 3: Robot arm 4: Surface sensor 5: Foreign matter removal device 6: Machine tool

Claims

A removal system that removes foreign matter adhering to machine tools.
It is equipped with a surface sensor, a foreign matter removing device, and a control device.
The surface sensor is configured to be able to detect the surface state of the contact surface of the surface of the jig of the machine tool, wherein the contact surface is a surface between members constituting the jig and the surface of the jig. At least one of the workpieces gripped by the tool and the surface in contact with it,
The foreign matter removing device is configured to be able to remove foreign matter from the close contact surface.
The control device includes a surface state storage unit, a foreign matter detection unit, and an operation instruction unit.
The surface state storage unit stores the surface state of the close contact surface in a state where no foreign matter is attached.
The foreign matter detection unit detects foreign matter adhering to the contact surface based on a comparison between the surface state of the contact surface detected by the surface sensor and the surface state stored in the surface state storage unit. Configured to be possible
The operation instruction unit is a removal system configured to be able to send an operation instruction to the foreign matter removing device when the foreign matter detecting unit detects a foreign matter.
In the removal system according to claim 1,
The surface sensor is a camera.
The surface state storage unit stores an image of the close contact surface in a state where no foreign matter is attached.
The foreign matter detecting unit is a removal system that detects foreign matter adhering to the close contact surface based on the difference between the image captured by the camera and the image stored in the surface state storage unit.
In the removal system according to claim 1,
The surface sensor is a displacement meter and
The surface state storage unit stores an image obtained by contouring the surface state of the close contact surface in a state where no foreign matter is attached, which is measured by the displacement meter.
The foreign matter detecting unit is a removal system that detects foreign matter adhering to the close contact surface based on the difference between the image obtained by contouring the measurement result by the displacement meter and the image stored in the surface state storage unit. ..
In the removal system according to any one of claims 1 to 3.
The foreign matter removing device is attached to a robot arm that performs a predetermined work on the machine tool.
The operation instruction unit is a removal system configured to be able to send a movement instruction based on position information indicating the position of a foreign matter detected by the foreign matter detection unit to the robot arm.
In the removal system according to claim 4,
The surface sensor is a removal system mounted on the robot arm.
In the removal system according to claim 4 or 5.
A plurality of the foreign matter removing devices are provided.
The operation instruction unit selects one of the foreign matter removing devices based on at least one of the position and size of the foreign matter detected by the foreign matter detecting unit, and gives a mounting instruction to instruct the mounting of the selected foreign matter removing device. A removal system that delivers to the robot arm.
A control device for a foreign matter removing device that removes foreign matter adhering to a machine tool.
It is provided with a surface state storage unit, a foreign matter detection unit, and an operation instruction unit.
In the surface state storage unit, no foreign matter adheres to the surface of the jig of the machine tool, which is in close contact with at least one of the member constituting the jig and the work gripped by the jig. The surface state of the contact surface detected by the surface sensor in the state is memorized and stored.
The foreign matter detection unit detects foreign matter adhering to the contact surface based on a comparison between the surface state of the contact surface detected by the surface sensor and the surface state stored in the surface state storage unit. Configured to be possible
The operation instruction unit is a control device configured to be able to send an operation instruction to the foreign matter removing device when the foreign matter detection unit detects a foreign matter.
In the control device according to claim 7.
The foreign matter removing device is attached to a robot arm that performs a predetermined work on the machine tool.
The operation instruction unit is a control device configured to be able to send a movement instruction based on position information indicating the position of the foreign matter detected by the foreign matter detection unit to the robot arm.
In the control device according to claim 7 or 8.
The surface sensor is a control device mounted on the robot arm.