Machine tool system

Abstract

To provide a machine tool system capable of shortening idling time.SOLUTION: A machine tool system includes a machine tool 1 and an NC controller 20 that controls the operation of the machine tool 1, the system further includes an AE sensor 10 and an AE amplifier 20. The AE sensor 10 detects an AE signal representing an elastic wave generated when a tool 3 comes into contact with a workpiece W when the tool 3 is rotated by a spindle 2 to machine the workpiece W, and transmits the AE signal to the AE amplifier. The AE amplifier 20 generates a tool contact signal by A / D converting and amplifying the AE signal sent from the AE sensor 10, and transmits the tool contact signal to the NC controller 20. The NC controller 30 controls an operation of the machine tool using the tool contact signal sent from the AE amplifier 20.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a machine tool system, and more particularly to a machine tool system having a function of determining the state of a tool mounted on the spindle of a machine tool.

Background Art

[0002] Conventionally, in machining using a machine tool, a touch switch sensor (tool setter) has been used to measure the tool length of a tool (machining tool).

[0003] As shown in FIG. 2, a touch switch sensor (tool setter) 100 is installed at the end of a work table 5 on which a work W of a machine tool is placed. When the tool 3 mounted on the NC machine spindle (main spindle) 2 of the machine tool is brought into contact with the touch switch sensor 100 (when brought into contact without rotating the tool 3), the touch switch sensor 100 detects a tool contact signal. Further, the touch switch sensor 100 transmits the detected tool contact signal to the NC controller 30. When the NC controller 30 receives the tool contact signal transmitted by the touch switch sensor 100, it calculates the tool length of the tool 3 using the tool contact signal.

[0004] Then, the NC controller 30 obtains the machining point (position data in the Z-axis direction) of the work using the tool length of the tool 3 obtained from the tool contact signal detected by the touch switch sensor 100, and controls the operation of the machine tool using the obtained machining point to machine the work W. Also, the machining point obtained using the touch switch sensor 100 is merely a numerical value in calculation, and there may be an error from the actual machining point. Therefore, currently, when the NC controller 30 applies the tool 3 to the machining point of the work for machining, instead of rotating the tool 3 at a high speed from the position of the machining point, the tool 3 is rotated at a rotational speed slower than the high speed, and after a predetermined time (predetermined seconds) has elapsed (after determining that there is no problem with the operation), the tool 3 is shifted to the high-speed rotation operation to machine the work W. Note that the touch switch sensor (tool setter) is disclosed in, for example, Non-Patent Document 1.

Prior Art Documents

Non-Patent Documents

[0005]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the method of using the above-described conventional touch switch sensor (tool setter) measures the wear amount of the tool by bringing the tool into contact with the touch switch sensor as a pre-step process every time the workpiece is machined. This process becomes the idle time when the workpiece is not being machined, and there is a problem that the machining time of the workpiece becomes long due to this idle time. In addition, the method of using the above-described conventional touch switch sensor (tool setter) starts machining from the calculated machining point position. Therefore, instead of immediately rotating the tool at high speed from that machining point position, the tool 3 is rotated at a low speed (for the sake of explanation, “trial operation”) that is slower than the high speed rotation for a predetermined time (predetermined seconds), and then the tool 3 is shifted to the high speed rotation operation to machine the workpiece W. Therefore, there is a problem that the machining takes time. Note that the above-described conventional technology also has a problem that the machining area is restricted because the touch switch sensor (tool setter) is installed on the worktable.

[0007] The present invention has been made in view of the above problems, and an object thereof is to provide a machine tool system capable of shortening the machining time of a workpiece.

Means for Solving the Problem

[0008] The present invention made to solve the above problems is a machine tool system including a machine tool that processes a workpiece placed on a worktable with a tool mounted on a spindle, and an NC controller that controls the operation of the machine tool according to a predetermined machining control program, comprising an AE (Acoustic Emission) sensor installed on the worktable, and an AE amplifier electrically connected to the AE sensor, wherein the frequency range of the AE sensor is set to detect a frequency region determined according to the material of the workpiece, and when the tool is rotated by the spindle to machine the workpiece, an AE signal representing an elastic wave generated when the tool contacts the workpiece is detected and transmitted to the AE amplifier, the AE amplifier generates a tool contact signal obtained by A / D converting and amplifying the AE signal sent from the AE sensor, transmits the tool contact signal to the NC controller, and the NC controller controls the operation of the machine tool using the tool contact signal sent from the AE amplifier to machine the workpiece on the machine tool. Further, when the tool is rotated by the spindle to machine the workpiece, it is desirable that the NC controller identifies a machining point of the workpiece based on the tool contact signal generated from the AE signal detected by the AE sensor when the tool first contacts the workpiece, and controls the operation of the machine tool to machine the workpiece from the machining point on the machine tool.

[0009] Thus, in the machine tool system of the present invention, when the spindle rotates to machine the workpiece, the AE sensor detects an AE signal representing an elastic wave generated when the tool contacts the workpiece, generates a tool contact signal obtained by A / D converting and amplifying the detected AE signal, and the NC controller controls the operation of the machine tool using the tool contact signal sent from the AE amplifier to machine the workpiece on the machine tool. According to this configuration, by detecting that the tool first contacts the workpiece, the actual machining point can be identified, eliminating the need for the process of measuring the tool length as in the above-described prior art. That is, according to the present invention, since "the operation of contacting the touch switch sensor with the tool to measure the tool length, which is performed as a previous step every time the workpiece is machined" is unnecessary, the idling time during which the machine tool does not machine the workpiece can be shortened. Further, according to the present invention, by detecting that the tool first contacts the workpiece, the actual machining point is identified, and since the workpiece is machined from the position of the actual machining point, machining can be performed by rotating the tool at high speed from the position of the machining point. Therefore, according to the present invention, since the "trial operation process" like the machine tool of the prior art becomes unnecessary, the working time can be shortened. Also, according to the present invention, there is no need to provide a touch switch sensor (tool setter) on the worktable, and since an AE sensor smaller in size than the touch switch sensor is installed, the machining area is not restricted as in the above-described prior art.

[0010] Further, it is desirable that the NC controller obtains the wear amount of the tool from the tool contact signal, corrects the position data set in the machining control program using the wear amount, and controls the operation of the machine tool using the corrected position data to machine the workpiece on the machine tool. According to this configuration, since the workpiece can be machined reflecting the wear amount of the tool during machining, high-precision machining becomes possible.

[0011] Also, it is desirable that the NC controller determines the state of the tool from the wear amount of the tool obtained from the tool contact signal. According to this configuration, since the state of the tool can be determined during machining of the workpiece, it is possible to prevent the tool from being damaged during machining, and it is possible to suppress the occurrence of poor quality due to tool breakage. That is, according to the present invention, it is possible to detect tool breakage (such as chipping or breakage of the cutting edge) without providing a touch switch sensor (tool setter).

[0012] Further, it is desirable that the NC controller generates wear amount information obtained by quantifying the wear amount of the tool determined from the tool contact signal and outputs the generated wear amount information. Thus, according to the present invention, the wear amount of the tool can be confirmed for each machining of the workpiece.

Effect of the Invention

[0013] According to the present invention, it is possible to provide a machine tool system capable of shortening the machining time of a workpiece.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Best Mode for Carrying Out the Invention

[0015] Hereinafter, a machine tool system according to an embodiment of the present invention will be described with reference to the drawings. Here, FIG. 1 is a schematic diagram showing the configuration of the machine tool system of the present embodiment. In the description of the present embodiment, the same components (or corresponding components) as those of the prior art machine tool system shown in FIG. 2 described above are denoted by the same reference numerals, and the description thereof is omitted or simplified.

[0016] As shown in FIG. 1, the machine tool system of the present embodiment includes an NC machine (hereinafter simply referred to as a "machine tool") 1 that machines a workpiece W placed on a worktable 5 with a tool (machining tool) 3 mounted on an NC machine spindle (hereinafter referred to as a "spindle") 2, and an NC controller 30 that drives and controls the machine tool 1.

[0017] Further, the above-mentioned machine tool system includes an AE (Acoustic Emission) sensor 10 installed on the worktable 5 of the machine tool 1, and an AE (Acoustic Emission) amplifier 20 electrically connected to the AE sensor 10 and electrically connected to the NC controller 30.

[0018] Specifically, the machine tool 1 includes a spindle 2 to which a tool 3 is attached, a worktable 5, and a drive mechanism (not shown) that relatively moves the spindle 2 and the worktable 5 three-dimensionally. The worktable 5 holds the work W to be machined in a state where it is placed and fixed at a predetermined position, and can move, for example, in the X-axis direction and the Y-axis direction of the XYZ coordinate axes. The spindle 2 is provided so as to be movable in the height direction (Z-axis direction) with respect to the worktable 5 above the worktable 5. In addition, a chuck mechanism is provided at the lower end of the spindle 2, and the tool 3 can be detachably attached to the lower end of the spindle 2 by the chuck mechanism.

[0019] The above-mentioned AE sensor 10 detects an AE signal (high-frequency signal) representing an elastic wave (elastic wave generated by elastic energy) generated when the tool 20 contacts the work W when the tool 3 is rotated by the spindle 2 to machine the work W. Further, the AE sensor 10 transmits the detected AE signal to the AE amplifier 20.

[0020] In addition, the AE sensor 10 is configured such that the detection frequency range can be set, and is installed near the work W installed on the worktable 5. Specifically, the frequency range of the AE sensor 10 is set so as to detect an AE signal (high-frequency signal) in a frequency region determined according to the material of the work W to be machined. For example, when the work W to be processed is "ceramic", the frequency range of the AE sensor 10 is set to detect AE signals (high-frequency signals) in a region within a predetermined range before and after around 300 KHz. Also, for example, when the work W to be processed is "copper", the frequency range of the AE sensor 10 is set to detect AE signals (high-frequency signals) in a region within a predetermined range before and after around 60 KHz. Further, for example, when the work W to be processed is "iron, stainless steel, FPR (fiber reinforced plastic)", the frequency range of the AE sensor 10 is set to detect AE signals (high-frequency signals) in a region within a predetermined range before and after around 150 KHz.

[0021] Note that, for example, the AE sensor 100 can use the "Early Observer (registered trademark)" manufactured by J.C.C. Co., Ltd., the applicant of the present application.

[0022] The AE amplifier 20 A / D-converts the AE signal sent from the AE sensor 10 to generate a tool contact signal that is amplified, and transmits the tool contact signal to the NC controller 30. Note that the AE amplifier 20 of the present embodiment is configured to A / D-convert and amplify the AE signal sent from the AE sensor 10 in "0.1 μs".

[0023] The NC controller 30 performs drive control of a drive mechanism (not shown) of the machine tool 1 and operation control of the tool 3 according to a predetermined machining control program. Also, when the NC controller 30 rotates the tool 3 by the spindle 2 to machine the work W, when the tool 3 first contacts the work W, the machining point of the work W is specified by the tool contact signal generated from the AE signal detected by the AE sensor 10, and the operation of the machine tool 1 is controlled to machine the work W from the specified machining point of the machine tool 1. Further, the NC controller obtains the wear amount of the tool 3 from the tool contact signal sent from the AE amplifier 30, corrects the position data (coordinate data (Z-axis coordinate data)) set in the machining control program using the wear amount, and controls the operation of the machine tool 1 using the corrected position data to machine the work W. Further, the NC controller 30 is capable of determining the state of the tool 3 (whether it is in a state where there is a risk of breakage) from the wear amount of the tool 3 obtained from the tool contact signal.

[0024] Also, a display device (not shown) such as a liquid crystal display is connected to the NC controller 30. Then, the NC controller 30 generates wear amount information obtained by quantifying the wear amount of the tool 3 obtained from the above tool contact signal, outputs it to a display device (not shown), and causes the display device to display the wear amount information. When the NC controller 30 determines that the tool 3 is in a broken state, it generates breakage notification information for notifying the risk of breakage of the tool 3, outputs it to a display device (not shown), and causes the display device to display the breakage notification information.

[0025] Thus, in the machine tool system of the present embodiment, when the tool 3 is rotated by the spindle 2 to machine the workpiece W, the AE sensor 10 detects an "AE signal representing the elastic wave generated when the tool 3 and the workpiece W come into contact", the AE amplifier 20 generates a "tool contact signal obtained by A / D converting and amplifying the AE signal", and the NC controller 30 uses the "tool contact signal to control the operation of the machine tool 1 to machine the workpiece W on the machine tool 1. Also, in the present embodiment, when the NC controller rotates the tool 3 by the spindle 2 to machine the workpiece W, the machining point of the workpiece W is specified by the tool contact signal generated from the AE signal detected by the AE sensor 10 when the tool 3 first contacts the workpiece W, and the operation of the machine tool 1 is controlled to machine the workpiece W from the machining point on the machine tool 1.

[0026] According to this configuration, by detecting that the tool 3 first contacts the workpiece W, the actual machining point can be specified, so that the "step of measuring the tool length" for calculating the machining point as in the above-described prior art becomes unnecessary. That is, according to the present embodiment, since the "operation of bringing the tool 3 into contact with the touch switch sensor to measure the wear amount of the tool 3, which is performed as a previous step every time the workpiece W is machined" becomes unnecessary, the idling time during which the machine tool 1 does not machine the workpiece W can be shortened. Further, according to the present embodiment, by detecting that the tool 3 first contacts the workpiece W, the actual machining point is specified, and since the workpiece W is being machined from the position of the actual machining point, the tool can be rotated at high speed from the position of the machining point to perform machining. Therefore, according to the present invention, the "trial operation process" as in the prior art machine tool becomes unnecessary, and the working time can be shortened.

[0027] Further, according to the present invention, it is not necessary to provide a touch switch sensor (tool setter) on the worktable, and since an AE sensor smaller in size than the touch switch sensor is installed, the machining area is not restricted as in the above-described prior art.

[0028] Also, in the present embodiment, the NC controller 30 obtains the wear amount of the tool 3 from the tool contact signal, corrects the position data set in the machining control program using the wear amount, and controls the operation of the machine tool 1 using the corrected position data to machine the workpiece W on the machine tool 1. According to this configuration, since the workpiece W can be machined reflecting the wear amount of the tool during machining of the workpiece W, high-precision machining becomes possible.

[0029] Also, in the present embodiment, the NC controller 30 determines the state of the tool from the wear amount of the tool obtained from the tool contact signal. According to this configuration, during machining of the workpiece W, the state of the tool 3 can be determined, so that breakage of the tool 3 during machining can be prevented, and the occurrence of quality defects due to breakage of the tool 3 can be suppressed. That is, according to the present embodiment, breakage (such as chipping or breakage of the cutting edge) of the tool can be detected without providing a touch switch sensor (tool setter).

[0030] In the present embodiment, the NC controller 30 generates wear amount information obtained by quantifying the wear amount of the tool 3 obtained from the tool contact signal, and outputs the generated wear amount information. According to this configuration, the amount of tool wear can be confirmed for each machining of the workpiece W.

Explanation of Signs

[0031] W... Workpiece 1... NC Machine Tool (Machine Tool) 2... NC Machine Spindle (Spindle) 3... Tool 5... Worktable 10... AE Sensor 20... AE Amplifier 30... NC Controller

Claims

1. A machine tool system comprising a machine tool for machining a workpiece placed on a worktable with a tool mounted on a spindle, and an NC controller for controlling the operation of the machine tool according to a predetermined machining control program, an AE (Acoustic Emission) sensor installed on the worktable, and an AE amplifier electrically connected to the AE sensor, wherein the frequency range of the AE sensor is set to detect a frequency range determined according to the material of the workpiece, and when the tool is rotated by the spindle to machine the workpiece, an AE signal representing an elastic wave generated when the tool contacts the workpiece is detected and transmitted to the AE amplifier, the AE amplifier generates a tool contact signal by A / D converting and amplifying the AE signal sent from the AE sensor, and transmits the tool contact signal to the NC controller, and the NC controller controls the operation of the machine tool using the tool contact signal sent from the AE amplifier to machine the workpiece on the machine tool. The machine tool system is characterized by this.

2. When the NC controller rotates the tool by the spindle to machine the workpiece, the machining point of the workpiece is specified by the tool contact signal generated from the AE signal detected by the AE sensor when the tool first contacts the workpiece, and the operation of the machine tool is controlled to machine the workpiece from the machining point on the machine tool. The machine tool system according to claim 1 is characterized by this.

3. The NC controller obtains the wear amount of the tool from the tool contact signal, corrects the position data set in the machining control program using the wear amount, and controls the operation of the machine tool using the corrected position data to machine the workpiece on the machine tool. The machine tool system according to claim 1 is characterized by this.

4. The NC controller determines the state of the tool from the amount of wear of the tool obtained from the tool contact signal, and the machine tool system according to claim 3 is characterized in that.

5. The NC controller generates wear amount information obtained by quantifying the amount of wear of the tool obtained from the tool contact signal, and outputs the generated wear amount information, and the machine tool system according to claim 3 or 4 is characterized in that.

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