DE112020000649T5 - Industrial machine, device for determining eccentricity, method for determining eccentricity and program - Google Patents

Abstract

A rotation command unit issues a rotation command to a rotating motor. A unit for detecting an angle of rotation detects a measured value of an angle of rotation of a grinding wheel from an angle of rotation sensor. A vibration detection unit detects a value related to vibration of the grinding wheel in a cutting direction based on the measurement value of displacement from a displacement sensor. A unit for determining eccentricity determines a value related to a deviation between a center of gravity of the tool and the central axis based on the measured value of the rotation angle and the value related to vibration.

Description

Technical area

The present invention relates to an industrial machine, a device for determining eccentricity, a method for determining eccentricity and a program.
This application claims priority to that filed in Japan on March 29, 2019 Japanese Patent Application No. 2019-068529 , the content of which is incorporated herein by reference.

Technical background

Patent Document 1 discloses a technology for a lathe-broaching machine capable of calculating an unbalance amount of a crankshaft from raw material.

State of the art documents

Patent documents

Patent Document 1 Japanese Unexamined Patent Application, First Publication No. 2015-44249

Summary of the invention

Problems to be Solved by the Invention

In a grinding machine that processes a workpiece with a rotating grinding wheel, the center of gravity of the grinding wheel preferably coincides with the fulcrum of the grinding wheel. When the center of gravity of the grinding wheel and the fulcrum of the grinding wheel are shifted from each other, the grinding wheel vibrates with the rotation of the grinding wheel, and the machining accuracy of the workpiece is lowered. It is therefore necessary to attach a correction weight to the grinding wheel so that the center of gravity of the grinding wheel and the fulcrum substantially coincide.

As a method of determining an attachment position of the correction weight, a method using a balance monitor is known. The balance monitoring device includes a rotation sensor that measures the rotational speed of a grinding wheel, and an acceleration sensor that measures vibration of a grinding wheel carrier and calculates a center of gravity deviation based on measured values of the rotation sensor and the acceleration sensor. In order to determine the center of gravity of the grinding wheel, it is necessary to calculate an amplitude of vibration of the grinding wheel. If the amplitude is calculated on the basis of the acceleration sensor, it is necessary to carry out multiple integration of a measured value. Therefore, it is likely that calculation of the deviation of the center of gravity using the acceleration sensor is affected by noise included in the measurement value of the acceleration sensor.

The object of the present invention is to create an industrial machine, a device for determining eccentricity, a method for determining eccentricity and a program with which the above-described problem of the present invention is solved.

Means of solving the problem

According to a first aspect of the present invention, a machine tool includes a tool having a disk shape, a rotating motor configured to rotate the tool about a central axis of the tool, an actuator configured to move the tool in a cutting direction, a rotation angle -Sensor, which is designed to measure an angle of rotation of the tool, a displacement sensor, which is designed to measure displacement of the tool in the cutting direction, and a control device, which is designed to regulate the rotating motor and the actuator, wherein the Control device, a unit for a rotation command, which is designed to output a rotation command to the rotating motor, a unit for detecting a rotation angle, which is designed to detect a measured value of the rotation angle from the rotation angle sensor, a unit for detecting Vibration designed to be a n value relating to the vibration of the tool in the cutting direction detected on the basis of a measurement value of the displacement from the displacement sensor, as well as including a unit for determining eccentricity, which is designed to have a value relating to a Deviation between a center of gravity of the tool and the central axis is recorded on the basis of a measured value of the angle of rotation and the value that relates to the vibration.

Effects of the invention

According to at least one of the aspects described above, the industrial machine determines the center of gravity of a tool on the basis of the measured value of the displacement from the displacement sensor. By using the measured value of the displacement, it is not necessary to perform gravity integration of the measured value, and thus, unlike a case in which an acceleration sensor is used, it is possible to obtain a value that relates to the eccentricity of the Without being influenced by noise.

Figure list

• 1 Fig. 13 is a plan view showing a structure of a grinding machine according to a first embodiment.
• 2 Fig. 13 is a schematic block diagram showing a configuration of a control device according to the first embodiment.
• 3 Fig. 13 is a flow chart illustrating a process for balancing a grindstone according to the first embodiment.
• 4th FIG. 13 is a flowchart illustrating a method for determining a vibration vector by the controller according to the first embodiment.
• 5A Fig. 13 is a diagram showing an example of amplitudes of chatter vibration of a grinding wheel before and after balancing the grinding wheel using the control device according to the first embodiment.
• 5B Fig. 13 is a diagram showing an example of amounts of chatter vibration of a grinding wheel before and after balancing the grinding wheel using the controller according to the first embodiment.

Mode for carrying out the invention

First embodiment

In the following, an embodiment will be described in detail with reference to the drawings.
1 Fig. 13 is a plan view showing a structure of a grinding machine according to the first embodiment. The grinding machine is an example of an industrial machine.

Structure of the grinding machine

A grinding machine 100 contains a base 110 , a receiving facility 120 , a grinding wheel carrier 130 , a control device 140 and a display device 150 . The base 110 is installed on a floor area of a factory. The receiving facility 120 and the grinding wheel carrier 130 are at a top of the base 110 present. The receiving facility 120 takes both ends of a workpiece W. and turns the workpiece W. around a spindle. The grinding wheel carrier 130 carries a grinding wheel 131 to edit the from the receiving device 120 recorded workpiece W. . The grinding wheel 131 is an example of a tool.
The following is a direction at right angles to the spindle at the top of the pedestal 110 referred to as an X direction, a direction in which the spindle extends is referred to as a Y direction, and becomes a direction at right angles to the top of the pedestal 110 referred to as a Z direction. That is, in the following description, the positional relationship of the grinding machine 100 will be described with reference to a three-dimensional rectangular coordinate system that includes an X-axis, a Y-axis, and a Z-axis.

The base 110 includes a Y-axis guide section 111 holding the grinding wheel carrier 130 supports so that it can be moved in the Y-axis direction and a Y-axis actuator 112 that is the grinding wheel carrier 130 on the Y-axis guide section 111 moved along in the Y-axis direction. The Y-axis actuator 112 can be designed as a linear motor or can be designed as a combination of a ball screw and a rotating motor.

The receiving facility 120 closes a headstock 121 holding one end of the workpiece W. with a substantially cylindrical shape, and carries a tailstock 122 one that is the other end of the workpiece W. wearing. The headstock 121 includes a rotating motor 123 one that is the workpiece W. rotates around an axis of the same.

The grinding wheel carrier 130 includes a grinding wheel 131 , an X-axis guide section 132 , an X-axis actuator 133 , a displacement sensor 134 , a rotating motor 135 as well as a rotation angle sensor 136 one.
The grinding wheel 131 is formed in a disk shape and is driven by the rotating motor 135 rotated around its central axis. The central axis of the grinding wheel 131 is parallel to the Y-axis. Abrasive grains for processing the workpiece W. are on the outer peripheral surface of the grinding wheel 131 present. On one side surface of the grinding wheel 131 there are a plurality of attachment holes for attaching a correction weight at equal intervals on the same circumference.
The X-axis guide section 132 stores the grinding wheel carrier 130 so that it is in the X-axis direction with respect to the socket 110 can be moved.
The X-axis actuator 133 moves the grinding wheel 131 in the X-axis direction on the X-axis guide section 132 along. The X-axis direction is a cutting direction of the grinding wheel 131 . The X-axis actuator 133 can be designed as a linear motor, or can be a combination of a ball screw and a rotating motor. The cutting direction is perpendicular to a direction of the pivot point.
The displacement sensor 134 measures the displacement of the grinding wheel carrier 130 in the X-axis direction with respect to the base 110 . The displacement sensor 134 is formed, for example, by a code ruler.
The rotating motor 135 turns the grinding wheel 131 around the central axis.
The rotation angle sensor 136 measures an angle of rotation of the grinding wheel 131 . The rotation angle sensor 136 is formed, for example, by a rotary encoder.

That is, with the grinding machine 100 according to the first embodiment, the workpiece W. between the headstock 121 and the tailstock 122 the receiving facility 120 and becomes the outer peripheral surface of the workpiece W. with the grinding wheel 131 sanded.

Configuration of the control device

2 Fig. 13 is a schematic block diagram showing a configuration of the control device according to the first embodiment.
The control device 140 controls the Y-axis actuator 112 , the rotating motor 123 , the X-axis actuator 133 and the rotating motor 135 . The control device 140 closes a processor 141 , a main memory 143 , a memory 145 as well as an interface 147 one. The processor 141 reads a program from memory 145 , loads the program into main memory 143 and performs processing according to the program. The processor 141 saves a memory area in the main memory 143 according to the program.
The program can implement some of the functions that the control device 140 having. For example, the program can have functions already in memory by means of a combination with another 145 stored program or by means of a combination with another program installed in another device. In addition, the control device 140 In another embodiment, a customer-specific large-scale integrated circuit (LSI), such as a programmable logic device (PLD), contain. Examples of the PLD include a programmable logic arrangement (programmable array logic - PAL), a general gate logic (generic array logic - GAL), a complex programmable logic device (complex programmable logic device - CPLD) or a user-programmable gate arrangement (field programmable gate array - FPGA). In this case, some or all of them can go through the processor 141 realized functions can be realized by the integrated circuit.

Examples of the memory 145 include a hard disk drive (HDD), a so-called solid-state drive (SSD), a magnetic disk, a magneto-optical disk, a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disc Read Only Memory) ), a semiconductor memory or the like. The memory 145 can be an internal medium that connects directly to a bus of the control device 140 connected, or an external medium that is connected via the interface 147 or a data transmission line with the control device 140 connected is. Furthermore, if the program is sent to the control device 140 is distributed via a data transmission line, the control device 140 that received the distribution, the program into main memory 143 load and perform the processing described above. In at least one embodiment, the memory is 145 a non-volatile physical storage medium.

The processor 141 functions as a unit by running a program 410 for detection of an angle of rotation, one unit 411 for detection of vibration, one unit 412 for calculating a target position, one unit 413 for calculating a target state variable, one unit 414 for calculating a command value, one unit 415 to issue a command, a unit 416 for a rotation command, a feedback unit 417 , one unity 418 for determining eccentricity, one unit 419 for setting a correction weight, one unit 420 for determining an amount of vibration and a unit 421 for display control.

The unit 410 for detecting an angle of rotation detects a measured value from the angle of rotation sensor 136 . That is, the unit 410 for detecting an angle of rotation detects a measured value of an angle of rotation of the grinding wheel 131 .
The unit 411 for detection of vibration detects a reading from the displacement sensor 134 . That is, the unit 411 for detection of vibration detects a measured value of the displacement of the grinding wheel 131 in the X-axis direction. In addition, the measured value of displacement in the X-axis direction is a value that relates to vibration of the grinding wheel 131 refers in the cutting direction.

the unit 412 for calculating a nominal position calculates a predetermined specific position as a nominal position of the grinding wheel 131 when balancing the grinding wheel 131 .

The unit 413 for calculating a nominal state variable calculates a nominal value of a state variable that relates to the displacement of the grinding wheel 131 relates, on the basis of the unit 412 target position calculated for calculating a target position. That is, the unit 413 for calculating a nominal state variable calculates values of a nominal speed, a nominal acceleration and a nominal jerk of the grinding wheel 131 in the X-axis direction.

The unit 414 for calculating a command value calculates a current command value for the X-axis actuator 133 based on the nominal value of the state variable of the grinding wheel 131 and a feedback signal from the feedback unit 417 . That is, the unit 414 for calculating a command value converts the setpoint of the state variable of the grinding wheel 131 into a current value for reaching the setpoint value and adds the value of the feedback signal to the current value in order to calculate the current command value.

The unit 415 for issuing a command is given by the unit 414 Current command value calculated for calculating a command value to the X-axis actuator 133 out. The unit 416 for a rotation command gives a rotation command for rotating the grinding wheel 131 with a predetermined number of revolutions to the rotating motor 135 out.

The return unit 417 gives a feedback signal that relates to the drive of the X-axis actuator 133 relates, on the basis of a difference between that by the unit 411 for recording of vibration recorded measured value of displacement of the grinding wheel 131 in the X-axis direction and that through the unit 412 target position of the grinding wheel determined for calculating a target position 131 out.

The unit 418 for determining eccentricity determines a vibration vector based on the determined by the unit 411 for recording of vibration recorded measured value of displacement of the grinding wheel 131 in the X-axis direction and that through the unit 410 for recording an angle of rotation recorded measured value of the angle of rotation of the grinding wheel 131 . The vibration vector indicates a direction and an amount in relation to a phase reference value (e.g. 0 °) that occurs when the grinding wheel is displaced 131 occurs by rotation of the grinding wheel 131 whose central axis and center of gravity do not coincide with each other. That is, the vibration vector is a value that relates to a difference between the position of the center of gravity of the grinding wheel 131 and the central axis relates.

The unit 419 for setting a correction weight determines the position of the mounting hole to which the correction weight is to be attached, as well as the weight of the correction weight based on the information provided by the unit 418 for determination of eccentricity determined position of the center of gravity and the position of the mounting hole of the grinding wheel 131 to find the fulcrum and center of gravity of the grinding wheel 131 essentially to coincide.

The unit 420 for determining an amount of vibration determines the amplitude of the chatter vibration caused by the eccentricity of the grinding wheel 131 is caused on the basis of by the unit 411 for recording of vibration recorded measured value of displacement in the X-axis direction of the grinding wheel 131 as well as through unity 410 for recording an angle of rotation recorded measured value of the angle of rotation of the grinding wheel 131 . In the following, the amplitude of the chatter vibration is also referred to as an amount of vibration. That is, the unit 420 For determining an amount of vibration, determines the amplitude of a frequency band that corresponds to the frequency of rotation of the grinding wheel by performing a corresponding filter process (e.g. a bandpass filter process) from time series of the measured values of displacement in the X-axis Direction, which determines the amount of vibration that the chatter vibration is related to. In addition, the frequency of rotation of the grinding wheel is determined based on the measured value of the rotation angle sensor 136 determined.

The unit 421 for display control gives to the display device 150 Display signals of a screen showing the position of the mounting hole and the weight of the correction weight given by the unit 419 for setting a correction weight can be set, and a screen showing the through the unit 420 for determining an amount of vibration represents certain amount of vibration when the grinding wheel 131 is balanced.

Process for balancing the grinding wheel

The following is a procedure for balancing the grinding wheel 131 the grinding machine 100 described.
3 Fig. 13 is a flow chart illustrating a process for balancing the grinding wheel according to the first embodiment.
The operator operates the control device 140 to start a balancing mode (step S1). Then the control device rotates 140 the grinding wheel 131 in a state in which there is no test weight to the grinding wheel 131 is added, and determines a vibration vector in a manner described below (step S2). The test weight is a weight that is added to unbalance the grinding wheel 131 to measure up. The operator then adds a test weight in a predetermined mounting hole that relates to a reference phase of the grinding wheel 131 relates (step S3). Then the control device rotates 140 the grinding wheel 131 in a state in which the test weight to the grinding wheel 131 is added, and determines a vibration vector in the manner described below (step S4).

Then calculate the unit 419 for setting a correction weight for the control device 140 a weight W _{1 of} an ideal correction weight based on Expression (1) (step S5). The ideal correction weight is a virtual correction weight that is independent of the position of the mounting hole of the grinding wheel 131 at a freely selected position on the grinding wheel 131 can be attached. The actual attachment position of the correction weight is limited by the position of the attachment hole.
[Equation 1] $$\begin{array}{l}{\mathrm{W.}}_1=\frac{{\mathrm{A.}}_1}{{\mathrm{A.}}_2}{\mathrm{W.}}_0\\ {\mathrm{A.}}_2=\sqrt{{\mathrm{A.}}_1{}^2+{\mathrm{A.}}_0{}^2-2{\mathrm{A.}}_1{\mathrm{A.}}_0\text{cos}\left({\theta }_1-{\theta }_0\right)}\end{array}$$

In equation (1), W _{0 is} the weight of the test weight. A ₀ is an amplitude component of the vibration vector in a state in which the test weight determined in step S2 is not added. A ₁ is an amplitude component of the vibration vector in a state in which the test weight determined in step S4 is added. A ₂ is an amplitude component of the vibration vector that cancels out the eccentricity. θ ₀ is a phase component of the vibration vector in a state where the test weight determined in step S2 is not added. θ ₁ is a phase component of the vibration vector in a state in which the test weight determined in step S4 is added.

Then the unit lays down 419 for setting a correction weight, fix an attachment angle φ1 of the ideal correction weight on the basis of expression (2) (step S6).
[Expression 2] $${\mathrm{<figure-callout\; id="1"\; label="\phi "\; filenames="DE112020000649T5\_0004.png,DE112020000649T5\_0006.png"\; state="\{\{state\}\}">\varphi </figure-callout>}}_1=180-{\text{cos}}^{-1}\left({\mathrm{A.}}_1{}^2-{\mathrm{A.}}_0{}^2-\frac{{\mathrm{A.}}_2{}^2}{2{\mathrm{A.}}_0{\mathrm{A.}}_2}\right)$$

Then determine the unit 419 for setting a correction weight, the weight W ₁ and an attachment _{angle φ 1 of} the correction weight as well as the positions φ ₂ and φ _{3 of} the two attachment holes, which _{are closest to the attachment angle φ 1} , and sets the weight W ₂ and W _{3 of} the correction weights, which in to be attached to each attachment hole, based on Expression (3) (step S7).
[Expression 3] $$\begin{array}{l}{\mathrm{W.}}_2=\frac{\text{sin}\left({\varphi }_3-{\varphi }_1\right)}{\text{sin}\left({\varphi }_3-{\varphi }_2\right)}{\mathrm{W.}}_1\\ {\mathrm{W.}}_3=\frac{\text{sin}\left({\varphi }_2-{\varphi }_1\right)}{\text{sin}\left({\varphi }_2-{\varphi }_3\right)}{\mathrm{W.}}_1\end{array}$$

Then there is the unit 421 for display control to the display device 150 outputs a display signal of a screen showing the positions φ ₂ and φ _{3 of} the mounting holes set in step S7 and the weights W ₂ and W _{3 of} the correction weights (step S8).

The operator then removes the test weight from the grinding wheel 131 (Step S9) and adds the correction weight with the weight that has been displayed to the attachment hole at the displayed position (Step S10). Then the operator rotates the grinding wheel 131 in a state in which the correction weight to the grinding wheel 131 is added, and determines a vibration vector in a manner to be described later (step S11). Then determine the unit 420 for determining an amount of vibration, an amplitude of a frequency band that corresponds to a frequency of rotation of the grinding wheel, by means of a corresponding filter process (e.g. a bandpass filter process) from time series of measured values of displacement in the X-axis direction, whereby an amount of vibration is determined (step S12). The unit 421 for display control gives a display signal of a screen indicating the certain amount of vibration of the grinding wheel 131 represents, to the display device 150 off (step S13).

The operator determines whether the displayed amount of vibration is equal to or greater than a reference value (step S14). When the amount of vibration is equal to or greater than the reference value (step S14: YES), the process returns to step S3, and balancing is further performed. When the amount of vibration is smaller than the reference value (step S14: NO), the operator ends the balancing.

Method for determining a vibration vector

4th FIG. 13 is a flowchart illustrating a method for determining a vibration vector by the controller according to the first embodiment.
When the control device 140 starts a process for determining a vibration vector in steps S2, S4 or S11, the unit calculates 412 for calculating a target position, a predetermined specific position as a target position of the grinding wheel 131 (Step S31). The unit 413 for calculating a nominal state variable, calculates nominal values of a state variable (speed, acceleration and jerk) that relate to the displacement of the grinding wheel 131 based on the target position calculated in step S31 (step S32).

The unit 414 for calculating a command value converts the setpoints of the state variable of the grinding wheel 131 into a current value (torque value) in order to achieve the setpoint values (step S33). The unit 414 for calculating a command value calculates a current command value V by taking a value from the feedback unit 417 output feedback signal is added to the current value converted in step S33 (step S34). The unit 415 for issuing a command, outputs the current command value calculated in step S34 to the X-axis actuator 133 off (step S35). Furthermore there is the unit 416 for a rotation command, a rotation command for rotating the grinding wheel 131 with a predetermined rotational speed to the rotating motor 135 off (step S36).

The unit 410 for detecting an angle of rotation detects a measured value of an angle of rotation of the grinding wheel 131 from the rotation angle sensor 136 , and the unit 411 for detection of vibration detects a measured value of the displacement of the grinding wheel 131 in the X-axis direction from the displacement sensor 134 (Step S37). The recorded measured value is stored in the main memory 143 or the like stored in connection with time. The return unit 417 gives a feedback signal that relates to the drive of the X-axis actuator 133 on the basis of the measured value of the displacement detected in step S37 and the target position calculated in step S31 (step S38). The feedback signal can be determined by means of proportional control, sliding state control and other methods.

The unit 418 for determining eccentricity determines whether a required number of measurement values for calculating the vibration vector have been collected (step S39). For example, the unit 418 for determining eccentricity, determine whether measured values relating to a predetermined period of time have been collected, or it can determine whether measured values relating to a predetermined number of rotations have been collected. If a required number of measurement values for calculating a vibration vector have not been collected (step S39: NO), the process returns to step S31 and collection of measurement values continues. On the other hand, when a required number of measurement values for calculating a vibration vector have been collected (step S39: YES), the unit determines 418 for determining eccentricity, a vibration vector based on time series of the collected measurement values of displacement (step S40). In particular, the unit determines 418 to determine eccentricity, an angle of rotation of the grinding wheel 131 at a time point of a peak of a waveform of the time series of the collected measurement values of displacement as a phase component of the vibration vector. Furthermore, the unit determines 418 for determining eccentricity, an amplitude of the waveform of the time series of the collected measured values of displacement as an amplitude component of the vibration vector.

Function of the control device when machining the workpiece

When the workpiece W. machined after balancing the grinding wheel 131 is completed, the operator brings the workpiece W. at the reception facility 120 on, actuates the control device 140 and activates the edit mode. The control device determines accordingly 140 based on the angle of rotation of the rotating motor 123 and the desired shape of the workpiece W. the position of one of the grinding wheels 131 facing contour of the workpiece W. than the target position of the grinding wheel 131 and processes the workpiece W. . When machining the workpiece W. collect the unit 410 for detecting an angle of rotation and the unit 411 for acquisition of vibration readings from the displacement sensor 134 and the rotation angle sensor 136 the grinding wheel 131 . The control device 140 performs processing from step S12 to step S13 based on the collected measurement values and shows the amount of vibration of the grinding wheel 131 on the display device 150 on. In this way, the operator can check the imbalance of the grinding wheel 131 every time the workpiece is processed W. check. It also determines the unit 420 for determining an amount of vibration, the amount of vibration corresponding to the frequency of rotation of the grinding wheel 131 in the step S12 and is thereby able to determine the amount of vibration due to the chatter vibration of the grinding wheel 131 from time series of measured values from displacement including machining of the workpiece W. to extract caused vibration. That is, the unit 420 for determining an amount of vibration is able to determine the amount of vibration due to chatter vibration even when machining the workpiece W. to determine correctly.

Function and effects

The control device 140 According to the first embodiment, as described above, determines the vibration vector of the grinding wheel 131 on the basis of the rotation angle sensor 136 and the displacement sensor 134 the grinding wheel 131 recorded measured values. Since the control device 140 need not perform multiple integration of the measured values using the measured values of displacement, unlike a case where an acceleration sensor is used, it is possible to determine the center of gravity without being influenced by noise.
5A and 5B 12 are diagrams showing examples of chatter vibration of a grinding wheel before and after balancing the grinding wheel using the control device according to the first embodiment. When balancing is performed according to the first embodiment, it is as in FIG 5A and 5B shown, possible, chatter vibration of the grinding wheel 131 that occurred before balancing, using the in 3 to reduce the balance shown to the same level as other disturbances. That is, with the in 5A In the example shown, it is possible to reduce the amplitude of chatter vibration to essentially 1/20. The in 5B In the example shown, it is possible to reduce the power of chatter vibration to essentially 1/10.
In addition, the control device determines 140 according to the first embodiment, a vibration vector as a value related to a deviation of the center of gravity from the central axis, however, another embodiment of the present invention is not limited thereto. For example, the control device 140 according to another embodiment, determine the position of the center of gravity in relation to the central axis as a value which relates to a deviation of the center of gravity and the central axis from one another.

The control device 140 According to the first embodiment, feedback control performs so that the grinding wheel 131 through the return unit 417 is brought to a specific position at the time of balancing the grinding wheel, but is not limited to this. For example, the control device must 140 According to another embodiment, when balancing the grinding wheel, no current command is sent to the X-axis actuator 133 output.

Second embodiment

The control device 140 According to the first embodiment, determines a vibration vector using a measurement value of the displacement sensor 134 . The control device 140 according to a second embodiment, however, determines a vibration vector based on a thrust of the X-axis actuator 13.

The unit 411 for detection of vibration of the control device 140 According to the second embodiment, in addition to the measured values according to the first embodiment, it also detects a current value from the X-axis actuator 133 . The current value of the X-axis actuator 133 is proportional to the amount of pushing force of the X-axis actuator 133 . The unit 418 for determining the eccentricity, the displacement of the X-axis actuator is calculated 133 based on the current value of the X-axis actuator 133 and determines the vibration vector.

The following describes the reason why the vibration vector is based on the thrust of the X-axis actuator 133 can be calculated. When balancing the grinding wheel 131 gives the unity 415 for outputting a command from the control device 140 a current command so that the grinding wheel 131 is brought to a specific position. However, the grinding wheel will 131 shifted in the X-axis direction due to chatter vibration. When displacement occurs in the X-axis direction, the feedback unit generates 417 the control device 140 a feedback signal to cancel the shift and outputs the feedback signal to the unit 414 for calculating a command value. This causes the X-axis actuator to exercise 133 the thrust corresponding to the displacement in the X-axis direction due to chatter vibration via feedback control.

Function and effects

This is how the control device determines 140 according to the second embodiment, the vibration vector of the grinding wheel 131 based on the thrust of the X-axis actuator 133 . The thrust of the X-axis actuator 133 is synchronized with the displacement in the X-axis direction due to the chatter vibration, as described above, by means of feedback control. Hence it is with the regulating device 140 possible according to the second embodiment, the vibration vector of the grinding wheel 131 to be determined in the same manner as in the first embodiment.

In addition, even if the control device 140 according to the second embodiment, the vibration vector of the grinding wheel 131 without Use of the measured value of the displacement sensor 134 determined, the present invention is not limited thereto. The control device 140 According to another embodiment, the vibration vector can be determined using the measurement value of the displacement sensor 134 and the thrust of the X-axis actuator 133 determine. For example, the control device 140 According to another embodiment, the vibration vector using an average value of the measured value of the displacement sensor 134 and that based on the thrust of the X-axis actuator 133 determine specific shift.

Although an embodiment has been described in detail with reference to the drawings, concrete configurations are not limited to those described above, and various structural changes and the like can be made.

For example, the control device regulates 140 according to the embodiment described above, the grinding machine 100 However, the present invention is not limited to this. For example, the control device 140 according to another embodiment regulate an industrial machine in which a tool other than the grinding wheel 131 is used. In addition, the shape of the grinding wheel 131 not limited to the shape of a disk and may be a circular saw blade or a grindstone having a cylindrical shape. In another embodiment, instead of the control device 140 an external measuring device can determine the eccentricity of the tool.

Industrial uses

According to the disclosure of the present invention described above, the industrial machine determines the center of gravity of the tool based on the measurement values of displacement from the displacement sensor. If the measured values of displacement are used, it is not necessary to perform multiple integration of the measured values, and thus it is possible to determine a value related to the eccentricity of the tool and different from a case where an acceleration -Sensor is used, is not influenced by noise.

List of reference symbols

100:

Grinding machine

110:

base

111:

Y-axis guide section

112:

Y-axis actuator

121:

Headstock

122:

Tailstock

123:

rotating motor

120:

Receiving facility

130:

Grinding wheel carrier

131:

Grinding wheel

132:

X-axis guide section

133:

X-axis actuator

134:

Displacement sensor

135:

rotating motor

136:

Rotation angle sensor

140:

Control device

141:

processor

143:

Main memory

145:

Storage

147:

interface

150:

Display device

410:

Unit for recording a rotation angle

411:

Unit for detecting vibration

412:

Unit for calculating a target position

413:

Unit for calculating a target state variable

414:

Unit for calculating a command value

415:

Unit for issuing a command

416:

Unit for a rotation command

417:

Return unit

418:

Unit for determining eccentricity

419:

Unit for determining a correction weight

420:

Unit for determining an amount of vibration

421:

Display control unit

W:

workpiece

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• JP 2019068529 [0001]
• JP 201544249 [0003]

Claims (7)

Industrial machine, which includes: a tool; a rotating motor configured to rotate the tool about a central axis of the tool; an actuator configured to move the tool in a cutting direction; a rotation angle sensor which is designed to measure a rotation angle of the tool; a displacement sensor adapted to measure displacement of the tool in the cutting direction; such as a control device designed to control the rotating motor and the actuator, wherein the control means includes: a rotation command unit configured to issue a rotation command to the rotating motor; a unit for detecting an angle of rotation which is designed to detect a measured value of the angle of rotation from the angle of rotation sensor; a vibration detection unit configured to detect a value related to vibration of the tool in the cutting direction based on a measurement value of displacement from the displacement sensor; such as a unit for determining eccentricity configured to detect a value related to a deviation between a center of gravity of the tool and the central axis based on a measurement value of the rotation angle and the value related to the vibration. Industrial machine after Claim 1 , where the value related to the vibration is a measurement of displacement from the displacement sensor. Industrial machine after Claim 1 wherein the control device further includes: a command issuing unit configured to issue to the actuator an actual command for positioning the tool at a specific position on the basis of a measurement value of the displacement from the displacement sensor, and the value related to the vibration is a value related to a pushing force of the actuator. Industrial machine according to one of the Claims 1 until 3 , wherein the control device further includes a unit for determining a correction weight, which is designed to determine a position and a weight of a correction weight to be attached to the tool. Device for determining eccentricity which is adapted to determine a value relating to the eccentricity of a tool with which a workpiece is machined by moving the tool in a cutting direction while rotating the tool by a rotating motor rotating around a central axis, the apparatus for determining eccentricity comprising: a rotation command issuing unit configured to issue a rotation command to the rotary motor; a unit for detecting a rotation angle which is designed to detect a measured value of a rotation angle of the rotating motor; a vibration detection unit configured to detect a value related to vibration of the tool in the cutting direction based on a measurement value of displacement of the tool in the cutting direction; such as a unit for determining eccentricity configured to detect a value related to a deviation between a center of gravity of the tool and the central axis based on a measurement value of the rotation angle and the value related to the vibration. Method for determining eccentricity with which a value is determined which relates to the eccentricity of a tool with which a workpiece is machined by moving the tool in a cutting direction while the tool is rotated about a central axis by a rotating motor wherein the method of determining eccentricity comprises the steps of: issuing a rotation command to the rotating motor; Acquiring a measurement value of a rotation angle of the rotating motor; Detecting a value relating to vibration of the tool in a cutting direction based on a measurement value of displacement of the tool in the cutting direction; and determining a value relating to a deviation between a center of gravity of the tool and the central axis on the basis of a measured value of the rotation angle and the value relating to the vibration. Program that is run by a computer and includes the following steps: Issuing a rotation command to a rotating motor of an industrial machine including a tool, the rotating motor being adapted to rotate the tool about a central axis of the tool and including an actuator adapted to move the tool in a cutting direction; Acquiring a measurement value of a rotation angle of the rotating motor; Detecting a value relating to vibration of the tool in the cutting direction based on a measurement value of displacement of the tool in the cutting direction; such as Determining a value relating to a deviation between a center of gravity of the tool and the central axis on the basis of a measured value of the rotation angle and the value relating to the vibration.

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