Grinding System

Abstract

To provide a grinding processing system that can perform satisfactory grinding processing even if the system cannot obtain an evaluated result unintentionally.SOLUTION: When a control device 30 of a grinding processing system 1 can obtain an evaluation signal S from a processing state evaluation device 4, the control device executes sign-management processing for making a grinder main body 10 execute processing for correcting a grinding wheel T, when an evaluation result of the evaluation signal S obtained from the processing state evaluation device 4 shows occurrence of a sign of deterioration in the grinding processing state by the grinding wheel T; and when the evaluation signal S from the processing state evaluation device 4 cannot be obtained, executes frequency management processing for making the grinder main body 10 execute processing for correcting the grinding wheel T when a frequency of grinding processing reaches a specified frequency.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a grinding system. [Background technology]

[0002] Grinding is performed, for example, by bringing a grinding wheel rotating at high speed into contact with a rotating workpiece. Therefore, in grinding, it is important to manage the state of the grinding wheel in order to maintain the grinding accuracy of the workpiece. For this reason, Patent Documents 1 to 3 have conventionally disclosed techniques for managing the state of the grinding wheel based on the processing state when the workpiece is ground by the grinding wheel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-151962 [Patent Document 2] Japanese Patent Publication No. 2020-23040 [Patent Document 3] Japanese Patent Application Publication No. 2020-15129 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when evaluating the processing state and managing the condition of the grinding wheel based on the evaluation results, it is at least necessary to acquire the evaluation results. Therefore, if the evaluation results cannot be acquired, especially if the evaluation results cannot be acquired unintentionally, it is impossible to grasp the condition of the grinding wheel. As a result, there is a risk that grinding will continue in a deteriorated state of the grinding wheel.

[0005] The present invention has been made in consideration of such problems, and aims to provide a grinding system that is capable of performing good grinding even when evaluation results cannot be obtained unintentionally. [Means for solving the problem]

[0006] One aspect of the present invention is a grinding machine comprising: a grinding machine body that performs grinding processing on a workpiece using a grinding wheel; an observation device provided on the grinding machine body for detecting measurement data observed during grinding in order to observe a processing state of the workpiece during grinding by the grinding machine body; a control device that counts the number of grinding processes that indicates the number of times the grinding process has been performed by the grinding machine body and controls the operation of the grinding machine body; Based on the measurement data detected by the observation device When the grinding machine main body grinds the workpiece The aforementioned a machining state evaluation device that performs evaluation processing for evaluation items related to the machining state and outputs an evaluation signal related to the evaluation results of the evaluation items to the control device; Equipped with the machining state evaluation device is set to perform the evaluation process for each grinding cycle, The control device When the evaluation signal can be acquired from the processing state evaluation device, if the evaluation result of the evaluation signal acquired from the processing state evaluation device indicates that a sign of deterioration in the grinding processing state by the grinding wheel has occurred, a sign management process is performed to cause the grinding machine main body to perform a correction process for the grinding wheel; Although the processing state evaluation device is set to acquire the evaluation signal, In the grinding processing system, if the evaluation signal cannot be obtained from the processing state evaluation device, a number management process is performed in which the grinding machine main body performs the correction process on the grinding wheel when the number of grinding processes reaches a specified number. [Effects of the Invention]

[0007] The control device performs symptom management processing when it can acquire an evaluation signal from the machining state evaluation device. The symptom management processing is a process that causes the grinding machine body to perform grinding wheel correction processing when the evaluation result of the evaluation signal acquired from the machining state evaluation device indicates that a symptom of deterioration in the grinding processing state by the grinding wheel has occurred. In this way, by performing grinding wheel correction processing at a stage before the grinding processing state deteriorates, it is possible to prevent deterioration of the grinding processing state. Therefore, it is possible to continue grinding the workpiece with high precision.

[0008] Furthermore, when symptom management processing is being performed, grinding wheel correction processing can be performed not when the number of times the workpiece has been ground reaches a predetermined number, but when it is evaluated that a symptom of a deterioration in the grinding state has occurred. Therefore, even if the number of times the workpiece has been ground exceeds a predetermined number, grinding processing can be continued without performing grinding wheel correction processing. This makes it possible to lengthen the interval between grinding wheel correction processing (the number of grinding processing times between the previous correction processing and the next correction processing). Therefore, the life of the grinding wheel can be extended.

[0009] However, the symptom management process by the control device requires acquisition of an evaluation signal from the machining state evaluation device. The control device may be unable to acquire the evaluation signal unintentionally, for example, when the power supply to the machining state evaluation device is cut off (power outage) or communication is interrupted. In this way, when the control device is unable to acquire the evaluation signal from the machining state evaluation device, the control device performs a count management process. The count management process is a process that causes the grinding machine body to perform a grinding wheel correction process when the number of grinding processes reaches a specified number. In other words, when the control device is unable to perform the symptom management process, the control device can maintain the condition of the grinding wheel in good condition by performing the count management process. As a result, deterioration of the grinding accuracy of the workpiece can be suppressed.

[0010] As described above, according to the above aspect, it is possible to provide a grinding system that is capable of performing good grinding even when evaluation results cannot be acquired unintentionally. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a plan view showing the configuration of a grinding system according to a first embodiment. [Figure 2] FIG. 2 is a diagram illustrating a configuration of a control device in FIG. [Figure 3] 3 is a diagram showing the contents of a symptom management command issued by a symptom management processing unit constituting the control device of FIG. 2. FIG. [Figure 4]10 is a flowchart showing a process performed by the machining state evaluation device of the second embodiment. [Figure 5] FIG. 10 is a diagram illustrating the configuration of a control device according to a third embodiment. [Figure 6] FIG. 10 is a diagram illustrating the configuration of a control device according to a fourth embodiment. [Figure 7] 10 is a diagram showing the contents of a symptom management command issued by a symptom management processing unit constituting the control device of the fourth embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] (Embodiment 1) 1. Overview of Grinding System 1 A grinding system 1 of this embodiment will be described with reference to Fig. 1. As shown in Fig. 1, the grinding system 1 includes a grinding machine 2, an observation device 3, and a processing state evaluation device 4. The grinding machine 2 rotates the workpiece W and also rotates the grinding wheel T, thereby moving the workpiece W and the grinding wheel T relative to each other, thereby grinding the workpiece W with the grinding wheel T. The grinding machine 2 can be configured in various ways, such as a cylindrical grinding machine, a cam grinding machine, or a surface grinding machine.

[0013] The observation device 3 is a device that observes the state of grinding performed by the grinding machine 2. The observation device 3 is provided on the grinding machine 2 in order to observe the state of grinding performed by the grinding machine 2. The observation device 3 can be, for example, a sensor that acquires the operation of the components that make up the grinding machine 2 during grinding, a sensor that acquires grinding sounds generated during grinding, a sensor that acquires surface images of the grinding wheel T and the workpiece W, or the like.

[0014] The machining state evaluation device 4 evaluates a plurality of evaluation items related to the grinding state of the grinding machine 2 based on measurement data observed by the observation device 3 while the grinding machine 2 is grinding the workpiece W. Then, the machining state evaluation device 4 outputs the evaluation results of the plurality of evaluated evaluation items to the grinding machine 2. In this embodiment, the machining state evaluation device 4 communicates with the grinding machine 2 to output each evaluation signal S including the evaluation results of the plurality of evaluation items.

[0015] Furthermore, when the grinding accuracy of the workpiece W is reduced due to the state of the grinding wheel T, the grinding machine 2 performs a correction process for the grinding wheel T. Specifically, the grinding machine 2 performs a dressing operation to sharpen the grinding wheel T.

[0016] The grinding machine 2 then determines the timing to perform the dressing operation based on the evaluation result of the evaluation signal S acquired from the processing state evaluation device 4. Specifically, the grinding machine 2 performs the dressing operation when the evaluation result of the evaluation signal S acquired from the processing state evaluation device 4 indicates that there is a sign of deterioration in the grinding processing state by the grinding wheel T.

[0017] However, the grinding machine 2 can determine the timing to perform the dressing operation based on the evaluation result only when the grinding machine 2 can acquire the evaluation signal S from the machining state evaluation device 4. However, there is a risk that a situation may occur in which the grinding machine 2 cannot acquire the evaluation signal S unintentionally, such as a situation in which the power supply to the machining state evaluation device 4 is cut off (power outage) or a situation in which communication is interrupted. In such a case, the grinding machine 2 cannot acquire the evaluation signal S from the machining state evaluation device 4.

[0018] Therefore, when the grinding machine 2 cannot acquire the evaluation signal S from the machining state evaluation device 4, it performs processing without using the evaluation signal S. Specifically, the grinding machine 2 performs a dressing operation when the number of grinding operations reaches a specified number.

[0019] In FIG. 1, the grinding system 1 is exemplified by a case in which one machining state evaluation device 4 is provided for one grinding machine 2. This configuration makes it possible to increase the communication speed between the grinding machine 2 and the machining state evaluation device 4. However, the grinding system 1 may also be configured so that one machining state evaluation device 4 is capable of communicating with multiple grinding machines 2. In this case, the machining state evaluation device 4 can be provided in, for example, a server device. In other words, the machining state evaluation device 4 and the multiple grinding machines 2 are configured to form a network.

[0020] 2. Grinding machine 2 configuration The configuration of the grinding machine 2 will be described with reference to Fig. 1. The grinding machine 2 includes a grinding machine body 10, an operation panel 20, and a control device 30. The grinding machine body 10 performs grinding on a workpiece W using a grinding wheel T. In detail, the grinding machine body 10 is configured to rotatably support the workpiece W, and to be able to grind the workpiece W by relatively moving the workpiece W and the grinding wheel T toward and away from each other while the grinding wheel T is rotating.

[0021] In this embodiment, the grinding machine body 10 is a cylindrical grinding machine, and a wheel head traverse type grinding machine is taken as an example. However, a table traverse type grinding machine or a grinding machine other than a cylindrical grinding machine can also be applied to the grinding machine body 10. The grinding machine body 10 in this embodiment includes a bed 11, a headstock 12, a tailstock 13, a traverse base 14, a wheel head 15, a sizing device 16, and a grinding wheel dressing device 17.

[0022] The bed 11 is placed on an installation surface. The headstock 12 is placed on the upper surface of the bed 11, on the near side in the X-axis direction (lower side in FIG. 1), which is the front side of the machine, and on one end side in the Z-axis direction, which is the left side of the machine (left side in FIG. 1). The headstock 12 supports one axial end of the workpiece W, and supports the workpiece W rotatably about the Z-axis. Furthermore, the headstock 12 drives a motor 12a provided on the headstock 12 to rotate the workpiece W about the Z-axis.

[0023] The tailstock 13 is disposed on the upper surface of the bed 11 in a position facing the headstock 12 in the Z-axis direction. That is, the tailstock 13 is disposed on the near side in the X-axis direction, which is the front of the machine (the lower side in FIG. 1), and on the other end side in the Z-axis direction, which is the right side of the machine (the right side in FIG. 2). The tailstock 13 supports the other axial end of the workpiece W and supports the workpiece W rotatably around the Z-axis. Therefore, both ends of the workpiece W are rotatably supported by the headstock 12 and the tailstock 13. The workpiece W may also be cantilevered by the headstock 12 alone.

[0024] The traverse base 14 is disposed on the upper surface of the bed 11 so as to be movable in the Z-axis direction. The traverse base 14 is moved by driving a motor 14a provided on the bed 11. The grinding wheel head 15 is disposed on the upper surface of the traverse base 14 so as to be movable in the X-axis direction. The grinding wheel head 15 is moved by driving a motor 15a provided on the traverse base 14. The grinding wheel head 15 is equipped with a rotatable grinding wheel T. The grinding wheel T rotates by driving a motor 15b provided on the grinding wheel head 15. The grinding wheel T is composed of a plurality of abrasive grains fixed together with a binder.

[0025] The sizing device 16 measures the dimension (diameter) of the workpiece W. The sizing device 16 is provided on the upper surface of the bed 11 so as to be movable in the Z-axis direction. The position of the sizing device 16 in the Z-axis direction is controlled by a feed mechanism 16a provided on the bed 11.

[0026] The grinding wheel dressing device 17 is a device for adjusting the shape of the grinding wheel T. That is, the grinding wheel dressing device 17 is a device for performing truing and dressing of the grinding wheel T. For example, a rotary dresser or a single-stone dresser can be used as the grinding wheel dressing device 17. In FIG. 1, the grinding wheel dressing device 17 is shown as a rotary dresser.

[0027] Truing here refers to the process of adjusting the shape of the grinding wheel T. Truing is the process of shaping the grinding wheel T to fit the shape of the workpiece W when the grinding wheel T is worn, worn out, has abrasive grains falling off, or has broken abrasive grains due to grinding, and the process of removing runout of the grinding wheel T due to uneven wear. Dressing is the process of dressing the grinding wheel T, adjusting the amount of protrusion of the abrasive grains, and creating cutting edges for the abrasive grains. In other words, the dressing operation is the process of correcting dullness, clogging, and missing grains.

[0028] The operation panel 20 is an input device that performs various input processes by an operator. For example, input of a machining program, input of various parameters, etc. is performed by operating the operation panel 20. The operation panel 20 is further equipped with a display device that can display information input by the operator, the status of the grinding machine main body 10, etc.

[0029] The control device 30 acquires the machining program and various information input from the operation panel 20, as well as detection information from various sensors that constitute the grinding machine body 10. The control device 30 then controls the operation of the grinding machine body 10 based on the acquired machining program and detection information from the various sensors that constitute the grinding machine body 10. In particular, the control device 30 controls each drive device that constitutes the grinding machine body 10.

[0030] The control device 30 controls the grinding machine main body 10 to execute a grinding cycle for the workpiece W. For example, one grinding cycle is a process for grinding one workpiece W. In other words, the control device 30 repeatedly executes the grinding cycle, thereby causing the grinding machine main body 10 to grind a plurality of workpieces W. The control device 30 also controls the display device of the operation panel 20 to display various information.

[0031] Furthermore, the control device 30 acquires an evaluation signal S from the machining state evaluation device 4. Based on the evaluation signal S, the control device 30 performs a process for correcting the grinding wheel T, particularly a process for managing the timing of performing a dressing operation. That is, the control device 30 determines the timing for performing the dressing operation of the grinding wheel T, and when the time to perform the dressing operation arrives, causes the grinding machine body 10 to perform the dressing operation.

[0032] However, there are cases where the control device 30 is unable to acquire the evaluation signal S from the machining state evaluation device 4. For such cases, the control device 30 causes the grinding machine body 10 to perform a dressing operation of the grinding wheel T when the grinding number of times, which indicates the number of grinding operations performed by the grinding machine body 10, reaches a specified number. To do this, the control device 30 counts the grinding number of times. The grinding number of times is the number of times a grinding cycle has been performed, and in particular, the control device 30 counts the number of times a grinding cycle has been performed since the previous dressing operation of the grinding wheel T was performed up to the present. When the dressing operation of the grinding wheel T is performed, the grinding number of times is reset.

[0033] 3. Observation equipment 3 The observation device 3 will be described with reference to FIG. 1. The observation device 3 is provided on the grinding machine body 10 to observe the state of grinding performed by the grinding machine 2. In this embodiment, the observation device 3 detects observation data related to the operation of the members constituting the grinding machine 2 as a physical quantity representing the state of grinding. For example, the observation data may be the acceleration of vibrations occurring in response to the surface state of the workpiece W, the displacement (amplitude) of vibrations, etc. In this case, the observation device 3 may measure the measurement data by directly or indirectly contacting the workpiece W, or may estimate the measurement data without contacting the workpiece W.

[0034] In particular, in this embodiment, one of the observation devices 3 is an acceleration sensor provided on the tailstock 13 of the grinding machine body 10, as shown in Fig. 1. The acceleration sensor serving as one of the observation devices 3 detects, for example, the acceleration of vibrations of the tailstock 13 observed during grinding of the workpiece W. The acceleration sensor serving as one of the observation devices 3 outputs acceleration data of the detected vibrations to the machining state evaluation device 4 as measurement data D.

[0035] Another of the observation devices 3 is a sizing device 16 constituting the grinding machine main body 10. The sizing device 16, which is another of the observation devices 3, acquires outer diameter data or surface shape data of the measured workpiece W. The sizing device 16 outputs the acquired outer diameter data or surface shape data as measurement data D to the machining state evaluation device 4. The observation device 3 may be configured to output to the machining state evaluation device 4 via the control device 30, or may be configured to output directly to the machining state evaluation device 4.

[0036] 4. Detailed configuration of the machining state evaluation device 4 The detailed configuration of the machining state evaluation device 4 will be described with reference to Fig. 1 and Fig. 2. In this embodiment, as shown in Fig. 1, the machining state evaluation device 4 functions as an edge computer provided corresponding to one grinding machine 2, and is capable of realizing high-speed calculation processing. The machining state evaluation device 4 is provided with a communication device independent of the control device 30 of the grinding machine 2, and is configured to be able to communicate with the control device 30. In addition, the machining state evaluation device 4 is provided with a power supply circuit independent of the grinding machine 2.

[0037] The machining state evaluation device 4 acquires the measurement data D from the observation device 3. Then, based on the acquired measurement data D, the machining state evaluation device 4 performs evaluation processing for a plurality of evaluation items related to the machining state by the grinding machine body 10 when the grinding machine body 10 grinds the workpiece W. The machining state evaluation device 4 outputs an evaluation signal S related to the evaluation results of the evaluation items to the control device 30.

[0038] In this embodiment, the multiple evaluation items can be appropriately selected from, for example, the presence or absence of chatter generated by grinding, the degree of chatter, the presence or absence of grinding burn, the surface roughness of the ground surface of the workpiece W, the shape of the workpiece W, etc. Then, the machining state evaluation device 4 performs evaluation processing for each evaluation item and outputs an evaluation signal S relating to the evaluation result of each evaluation item to the control device 30 via communication.

[0039] 2, the machining state evaluation device 4 performs evaluation processing for, for example, four evaluation items. In this embodiment, "evaluation item 1" is the presence or absence of chatter that occurs during grinding, "evaluation item 2" is the presence or absence of grinding burn, "evaluation item 3" is the surface roughness of the workpiece W, and "evaluation item 4" is the shape of the workpiece W.

[0040] Furthermore, the processing state evaluation device 4 generates evaluation results for each of "evaluation item 1" to "evaluation item 4" using four levels: "good," "poor," "warning," and "failure." The evaluation result "good" indicates that the state of the evaluation item is good. The evaluation result "poor" indicates that the state of the evaluation item is poor. The evaluation result "warning" indicates that there are signs of deterioration in the grinding processing state by the grinding wheel T. In other words, the evaluation result "warning" indicates that there is a possibility of a defect occurring as the state of the grinding wheel T deteriorates. The evaluation result "failure" indicates that the evaluation itself has failed. Examples of failures in the evaluation itself include when an evaluation result cannot be generated or when an abnormal value that does not exist as a normal evaluation result is output.

[0041] The machining state evaluation device 4 estimates the presence or absence of chatter, the presence or absence of grinding burn, and surface roughness and determines the level based on, for example, the vibration of the tailstock 13 in the measurement data D, and outputs an evaluation signal S including the evaluation results to the control device 30 of the grinding machine 2. Furthermore, the machining state evaluation device 4 determines the presence or absence of grinding burn and the level of the shape of the workpiece W based on, for example, the vibration of the tailstock 13 and the outer diameter of the workpiece W in the measurement data D, and outputs an evaluation signal S including the evaluation results to the control device 30 of the grinding machine 2.

[0042] In the processing state evaluation device 4, the types of evaluation results for each evaluation item are not limited to the above four types, but can be set arbitrarily. However, the types of evaluation results shall include at least "Warning."

[0043] In this embodiment, the machining state evaluation device 4 can perform evaluation processing, for example, for each grinding cycle. That is, the machining state evaluation device 4 performs evaluation processing for each of "evaluation item 1" to "evaluation item 4" for all workpieces W and generates evaluation results. Then, the machining state evaluation device 4 outputs the evaluation results to the control device 30 before grinding of the next workpiece W is started.

[0044] Here, when the workpiece W has one grinding location, one grinding cycle is a process of grinding one grinding location on one workpiece W. In this case, after one grinding cycle is completed, the machining state evaluation device 4 performs an evaluation process for the grinding location.

[0045] Furthermore, for example, in a workpiece W having a plurality of journal portions, such as a crankshaft or a camshaft, the same grinding process may be performed on each of the plurality of journal portions. When the workpiece W has a plurality of grinding locations of the same type, such as a plurality of journal portions, one grinding cycle is a process of grinding a plurality of grinding locations on one workpiece W. In this case, after the completion of one grinding cycle, the machining state evaluation device 4 may perform an evaluation process on the plurality of grinding locations.

[0046] In addition, evaluation processing may be performed on some of the grinding areas that have already been ground during one grinding cycle in which multiple grinding areas of the same type are to be ground. In this case, evaluation processing can be performed while grinding is being performed on the remaining grinding areas of the workpiece W, and the evaluation processing can be completed before one grinding cycle ends.

[0047] 5. Detailed configuration of grinding wheel correction processing by the control device 30 Of the configuration of the control device 30, the function related to grinding wheel adjustment processing will be described with reference to Figures 2 and 3. The control device 30 is made up of a PLC (Programmable Logic Controller) 31 and a CNC (Computerized Numerical Control) device 32.

[0048] The PLC 31 communicates with the machining state evaluation device 4 to obtain an evaluation signal S from the machining state evaluation device 4. Based on the evaluation signal S, the PLC 31 determines whether or not to dress the grinding wheel T. When the CNC device 32 receives a command from the PLC 31 to dress the grinding wheel T, it causes the grinding machine main body 10 to perform a dressing operation on the grinding wheel T.

[0049] As shown in FIG. 2, the PLC 31 includes a signal acquisition unit 41, an evaluation item setting unit 42, an evaluation item validity determination unit 43, an evaluation signal acquisition determination unit 44, and an output unit 45.

[0050] The signal acquiring unit 41 acquires the evaluation signal S output from the processing state evaluating device 4. That is, the signal acquiring unit 41 acquires the evaluation signal S relating to the evaluation results of the evaluation items evaluated by the processing state evaluating device 4. In the present embodiment, the processing state evaluating device 4 outputs an evaluation signal S relating to the evaluation results of each of the multiple evaluation items. Therefore, the signal acquiring unit 41 is configured to be able to acquire the evaluation signal S relating to the evaluation results of each of the multiple evaluation items output from the processing state evaluating device 4. When the signal acquiring unit 41 acquires each evaluation signal S from the processing state evaluating device 4, it turns on the "signal" for each evaluation item by, for example, ladder logic, and then switches to the "signal OFF."

[0051] The evaluation item setting unit 42 sets whether or not evaluation items are required to be acquired from the processing state evaluation device 4, among the multiple evaluation items. That is, the evaluation item setting unit 42 sets evaluation items to be acquired from the processing state evaluation device 4 as "valid," and sets evaluation items not to be acquired (unnecessary) as "invalid."

[0052] The evaluation item setting unit 42 may, for example, allow the operator to arbitrarily set "valid" or "invalid" for the required evaluation items in advance, or may set "valid" or "invalid" according to the evaluation items in the evaluation signal S acquired by the signal acquisition unit 41. As shown in FIG. 2, the evaluation item setting unit 42 of this embodiment takes as an example a case where "valid" or "invalid" can be set for each of "evaluation item 1" to "evaluation item 4." "Evaluation item 1," "evaluation item 2," and "evaluation item 4" are set to "valid," and "evaluation item 3" is set to "invalid."

[0053] The signal acquisition unit 41 acquires evaluation signals S for evaluation items that have been set to "enabled" by the evaluation item setting unit 42. On the other hand, the signal acquisition unit 41 does not acquire evaluation signals S for evaluation items that have been set to "disabled" by the evaluation item setting unit 42. In FIG. 2, the signal acquisition unit 41 acquires evaluation signals S for "evaluation item 1," "evaluation item 2," and "evaluation item 4," but does not acquire an evaluation signal S for "evaluation item 3." Then, if the signal acquisition unit 41 has acquired evaluation signals S for each of the three evaluation items that it should acquire, it switches the state of each of the evaluation items to "signal ON."

[0054] The evaluation item validity determination unit 43 checks the setting status of the evaluation item setting unit 42. Then, the evaluation item validity determination unit 43 determines "Yes" if the setting status of the evaluation item setting unit 42 is such that at least one of "Evaluation Item 1" to "Evaluation Item 4" is set to "Valid." On the other hand, the evaluation item validity determination unit 43 determines "No" if the setting status of the evaluation item setting unit 42 is such that all of "Evaluation Item 1" to "Evaluation Item 4" are set to "Invalid."

[0055] When the evaluation item validity determination unit 43 determines that at least one of "evaluation item 1" to "evaluation item 4" is set to "valid" as the setting state of the evaluation item setting unit 42, the evaluation signal acquisition determination unit 44 determines whether or not the evaluation signal S related to the evaluation item set to "valid" has been switched to "signal ON" by the signal acquisition unit 41. In other words, the evaluation signal acquisition determination unit 44 determines whether or not the evaluation signal S related to the evaluation result has been acquired from the processing state evaluation device 4 for the evaluation item set to "valid" in the evaluation item setting unit 42.

[0056] As described above, after performing the evaluation process, the machining state evaluation device 4 outputs an evaluation signal S relating to the evaluation result to the PLC 31 of the control device 30 via communication. The signal acquisition unit 41 of the PLC 31 acquires, via communication, the evaluation signal S relating to the evaluation item set to "enabled" in the evaluation item setting unit 42. In this case, upon acquiring the evaluation signal S, the signal acquisition unit 41 switches from "signal OFF" to "signal ON."

[0057] However, if the communication state between the control device 30 and the machining state evaluation device 4 deteriorates or if the power supply to the machining state evaluation device 4 is cut off due to a power outage or the like, the machining state evaluation device 4 cannot transmit the evaluation signal S to the control device 30. In this case, the signal acquisition unit 41 of the PLC 31 cannot switch the evaluation signal S for the evaluation item set to "enabled" from "signal OFF" to "signal ON."

[0058] The evaluation signal acquisition determination unit 44 determines "Yes" when the signal is switched to "signal ON." That is, the evaluation signal acquisition determination unit 44 determines "Yes" when all evaluation signals S have been acquired from the machining state evaluation device 4 for the evaluation items set to "enabled" in the evaluation item setting unit 42. On the other hand, the evaluation signal acquisition determination unit 44 determines "No" when the signal is "signal OFF." That is, the evaluation signal acquisition determination unit 44 determines "No" when no evaluation signal S has been acquired from the machining state evaluation device 4 for the evaluation items set to "enabled" in the evaluation item setting unit 42. Note that the evaluation signal acquisition determination unit 44 determines "No" when even one of the multiple evaluation items that should be acquired cannot be acquired.

[0059] The output unit 45 selects and executes one of the symptom management process and the number management process based on the determination results of the evaluation item validity determination unit 43 and the evaluation signal acquisition determination unit 44. The output unit 45 generates a command based on the selected management process and outputs the generated command to the CNC device 32. The command here is mainly a command to the grinding machine body 10 regarding the execution of a dressing operation.

[0060] The output unit 45 includes a symptom management processing unit 45a that performs symptom management processing, and a count management processing unit 45b that performs count management processing. The symptom management processing is processing that causes the grinding machine body 10 to perform a dressing operation of the grinding wheel T when it is evaluated that a symptom of deterioration in the grinding processing state by the grinding wheel T has occurred. However, the symptom management processing can be configured to include other processing. The count management processing is processing that causes the grinding machine body 10 to perform a dressing operation of the grinding wheel T when the grinding processing count, which indicates the number of grinding processing times by the grinding machine body 10, reaches a specified count.

[0061] The symptom management processing unit 45a of the output unit 45 executes symptom management processing when the evaluation item validity determination unit 43 determines that at least one of the multiple evaluation items is set to "valid" and the evaluation signal acquisition determination unit 44 determines that the signal has been switched to "signal ON." In other words, when the signal acquisition unit 41 can acquire an evaluation signal S related to the evaluation result of the acquired and set evaluation item from the machining state evaluation device 4, the symptom management processing unit 45a executes symptom management processing based on the evaluation result of the acquired evaluation signal S. The symptom management processing unit 45a executes symptom management processing to output a symptom management command R1 to the CNC device 32.

[0062] The symptom management command R1 will be described with reference to Fig. 3. The symptom management command R1 includes a first command R11, a second command R12, a third command R13, and a fourth command R14. In other words, the symptom management processing unit 45a executes symptom management processing to determine one of the commands R11 to R14 included in the symptom management command R1, and outputs the determined symptom management command R1 to the CNC device 32.

[0063] 3, each of the commands R11 to R14 of the symptom management command R1 is set according to the evaluation result of the evaluation signal S acquired by the signal acquisition unit 41. As described above, there are four levels of the evaluation result: "good," "bad," "warning," and "failure." Therefore, each of the commands R11 to R14 is set as a command corresponding to each of the four levels.

[0064] The first command R11 is a command that is determined when the evaluation result is "good." The first command R11 is a command to lengthen the interval between dressings of the grinding wheel T by the grinding wheel dressing device 17 (extending the dressing life). In other words, the first command R11 is a command to the grinding machine main body 10 not to perform the dressing operation of the grinding wheel T. If the evaluation result is "good," it is determined that there is no need to dress the grinding wheel T, and therefore the first command R11 is set as described above. Furthermore, the first command R11 includes a command to display "Evaluation result: good" on the display device of the operation panel 20.

[0065] The second command R12 is a command that is determined when the evaluation result is "fail." If the evaluation result is "fail," continuing grinding of the workpiece W may result in the generation of another defective workpiece W. Therefore, the second command R12 is a command to stop the grinding cycle for the next workpiece W. In other words, the second command R12 is a command to stop grinding of the workpiece W by the grinding machine main body 10. Furthermore, the second command R12 includes a command to display "Evaluation result: Fail" on the display device of the operation panel 20. The second command R12 can also perform processing to inform external devices, such as a management device or a terminal of a manager or worker, that the evaluation result is "fail."

[0066] The third command R13 is a command that is determined when the evaluation result is "Warning." That is, the third command R13 is a command that is determined when there are signs of deterioration in the grinding processing state. When there are signs of deterioration in the grinding processing state, it means that the target evaluation item is not defective but is approaching defective. Therefore, the third command R13 is a command to cause the grinding machine main body 10 to perform a dressing operation of the grinding wheel T. Furthermore, the third command R13 includes a command to cause the display device of the operation panel 20 to display "Evaluation result: Warning." The number of grinding operations since the previous dressing operation can also be added to the display content. The third command R13 can also perform processing to notify external devices, such as the management device or the manager's or operator's terminal, that the evaluation result is "Warning." The number of grinding operations since the previous dressing operation can also be added to the display content.

[0067] The fourth command R14 is a command that is determined when the evaluation result is "failure." If the evaluation result is "failure," the evaluation process has not been performed appropriately, meaning that the machining state cannot even be evaluated. Continuing to grind the workpiece W in this state may result in the production of a defective workpiece W. Therefore, the fourth command R14 is a command to stop the grinding cycle for the next workpiece W. In other words, the fourth command R14 is a command to stop the grinding process of the workpiece W by the grinding machine main body 10. Furthermore, the fourth command R14 includes a command to display "Evaluation result: Fail" on the display device of the operation panel 20. The fourth command R14 can also perform processing to inform external devices, such as a management device or the terminals of the manager and worker, that the evaluation result is "failure."

[0068] The number of times management processing unit 45b of the output unit 45 executes the number of times management process when the evaluation item validity determination unit 43 determines that all evaluation items are set to "invalid," i.e., when all evaluation items are set to not require acquisition. Furthermore, the number of times management processing unit 45b executes the number of times management process when the evaluation signal acquisition determination unit 44 determines that the signal has not been switched to "signal ON." In other words, when the signal acquisition unit 41 cannot acquire the evaluation signal S related to the evaluation results of the evaluation items that have been set to acquire from the machining state evaluation device 4, the number of times management processing unit 45b executes the number of times management process. By executing the number of times management process, the number of times management processing unit 45b outputs a number of times management command R2 to the CNC device 32.

[0069] The number of times management processing is processing for causing the grinding machine body 10 to perform a dressing operation of the grinding wheel T when the grinding process count, which indicates the number of grinding processes performed by the grinding machine body 10, reaches a specified number. Therefore, the number of times management processing unit 45b acquires the number of grinding processes since the previous dressing operation and determines whether the acquired number of grinding processes has reached the stored specified number. When the number of grinding processes has reached the specified number, the number of times management processing unit 45b outputs a number of times management command R2 to the CNC device 32 to cause the grinding wheel T to perform a dressing operation.

[0070] On the other hand, if the number of grinding operations has not reached the specified number, the number management processing unit 45b outputs a number management command R2 to the CNC device 32 to not perform the dressing operation of the grinding wheel T. Note that the number management processing unit 45b can also be configured not to output any command to the CNC device 32 if the number of grinding operations has not reached the specified number.

[0071] Furthermore, the number of times management command R2 output by the number of times management processing unit 45b may include a command to display "number of times management" on the display device of the operation panel 20. The number of times management command R2 can also perform processing to instruct external devices such as the management device and the terminals of the manager and worker to perform number of times management processing.

[0072] Here, while the symptom management processing is being performed by the symptom management processing unit 45a, there are cases where the signal acquiring unit 41 is unable to acquire the evaluation signal S from the machining state evaluating device 4 due to, for example, a communication interruption. Then, when the first command R11, which is the dressing life extension, is continuously determined by the symptom management processing, there are cases where the number of grinding operations has already exceeded the specified number.

[0073] Therefore, when the symptom management process is performed and the number of grinding processes exceeds the specified number, if the signal acquisition unit 41 is unable to acquire the evaluation signal S from the processing state evaluation device 4, the number management processing unit 45b determines that the number of grinding processes has reached the specified number and outputs a number management command R2 to the CNC device 32 to cause the grinding machine main body 10 to perform a dressing operation of the grinding wheel T.

[0074] When the indication management processing unit 45a of the output unit 45 of the PLC 31 outputs commands R11 to R14, the CNC device 32 controls the grinding machine body 10 based on the output commands R11 to R14.

[0075] When a first command R11 is output from the symptom management processing unit 45a of the output unit 45, the CNC device 32 performs dressing life extension and displays on the screen. When a second command R12 is output from the symptom management processing unit 45a of the output unit 45, the CNC device 32 stops the next grinding cycle and displays on the screen. When a third command R13 is output from the symptom management processing unit 45a of the output unit 45, the CNC device 32 executes a dressing operation and displays on the screen. When a fourth command R14 is output from the symptom management processing unit 45a of the output unit 45, the CNC device 32 stops the next grinding cycle and displays on the screen.

[0076] 6.Effects As described above, the control device 30 performs symptom management processing when it can acquire the evaluation signal S from the machining state evaluation device 4. The symptom management processing is processing in which the grinding machine main body 10 performs a dressing operation of the grinding wheel T when the evaluation result of the evaluation signal S acquired from the machining state evaluation device 4 indicates that a symptom of deterioration in the grinding processing state by the grinding wheel T has occurred.

[0077] In particular, when the evaluation result of the evaluation signal S acquired from the machining state evaluation device 4 indicates that a sign of deterioration in the grinding state by the grinding wheel T has occurred, the control device 30 executes the command content of the third command R13 of the sign management command R1. That is, the control device 30 causes the grinding machine main body 10 to perform a dressing operation of the grinding wheel T based on the evaluation result of the evaluation signal S. In this way, by performing correction processing on the grinding wheel T at a stage before the grinding state deteriorates, it is possible to prevent deterioration of the grinding state. Therefore, it is possible to continue grinding the workpiece W with high precision.

[0078] Furthermore, when symptom management processing is being performed, the dressing operation of the grinding wheel T is not performed when the number of times the workpiece W has been ground reaches a specified number, but can be performed when it is evaluated that a symptom of a deterioration in the grinding state has occurred. Therefore, even if the number of times the workpiece W has been ground exceeds the specified number, grinding can be continued without performing the dressing operation of the grinding wheel T. This makes it possible to lengthen the interval between dressing operations of the grinding wheel T (the number of grinding operations between the previous dressing operation and the next dressing operation). Therefore, the life of the grinding wheel T can be extended.

[0079] However, the symptom management process by the control device 30 requires acquisition of the evaluation signal S from the machining state evaluation device 4. The control device 30 may be unable to acquire the evaluation signal S unintentionally, for example, when the power supply to the machining state evaluation device 4 is cut off (power outage) or when communication is interrupted. In this way, when the control device 30 is unable to acquire the evaluation signal S from the machining state evaluation device 4, the control device 30 performs a count management process. The count management process is a process in which the grinding machine main body performs a dressing operation of the grinding wheel T when the number of grinding operations reaches a specified number.

[0080] That is, in a situation where the symptom management process cannot be performed, the control device 30 performs the number management process, thereby maintaining the condition of the grinding wheel T in a good state. As a result, deterioration of the grinding accuracy of the workpiece W can be suppressed.

[0081] In this embodiment, the processing state evaluation device 4 is configured to perform evaluation processing for a plurality of evaluation items related to the processing state ("evaluation item 1" to "evaluation item 4"). The control device 30 has an evaluation item setting unit 42 that sets evaluation items to be acquired from the processing state evaluation device 4 out of the plurality of evaluation items.

[0082] When the control device 30 can acquire an evaluation signal S relating to the evaluation results of the set evaluation items from the processing state evaluation device 4, the control device 30 performs symptom management processing based on the evaluation results of the evaluation signal S acquired from the processing state evaluation device 4. On the other hand, when the control device 30 cannot acquire an evaluation signal S relating to the evaluation results of the set evaluation items from the processing state evaluation device 4, the control device 30 performs count management processing.

[0083] When the processing state evaluation device 4 is capable of performing evaluation processing for multiple evaluation items, the control device 30 selectively performs symptom management processing and number management processing as described above, thereby suppressing deterioration in the grinding accuracy of the workpiece W.

[0084] In this case, if the evaluation item setting unit 42 is set to not require acquisition for all evaluation items, the control device 30 will not acquire the evaluation signal S from the machining state evaluation device 4. Therefore, the control device 30 performs the number of times management process.

[0085] 3, the symptom management command R1 is set to four levels of commands R11 to R14. Then, the command contents according to the commands R11 to R14 are implemented. In particular, when the evaluation result is "defective" or "failed," the command contents of the second command R12 and the fourth command R14 are implemented, thereby making it possible to prevent defects from being generated in the workpiece W.

[0086] (Embodiment 2) The processing by the machining state evaluation device 4 in the grinding system 1 of the second embodiment will be described with reference to Fig. 4. The machining state evaluation device 4 of the first embodiment performs evaluation processing for target evaluation items on all workpieces W. The machining state evaluation device 4 of the present embodiment changes the timing of performing the evaluation processing depending on the degree of success of the evaluation result.

[0087] 4, after the workpiece W has been ground, the machining state evaluation device 4 performs an evaluation process for the evaluation items on the workpiece W (S1). Subsequently, the machining state evaluation device 4 determines whether the evaluation result is "good" or not (S2).

[0088] Next, if the evaluation result is "good" (S3: Yes), the processing state evaluation device 4 determines whether the degree of goodness is high. For example, if a numerical value is obtained by the evaluation process and the numerical value is between the lower limit and the upper limit representing "good," the evaluation result is evaluated as "good." In this case, if the numerical value is close to the median, the degree of goodness is determined to be "high," and if the numerical value is close to the lower limit or the upper limit, the degree of goodness is determined to be "low."

[0089] If the degree of goodness is "high" (S4: Yes), the timing of the evaluation process is set to a first set number of times Na (S5). Next, the number of grinding processes N since the previous evaluation process is obtained (S6). Then, it is determined whether the number of grinding processes N has reached the first set number of times Na (S7). If the number of grinding processes N has not reached the first set number of times Na (S7: No), the process of S6 is performed and the process is repeated.

[0090] In S7, if the number of grinding operations N reaches the first set number of operations Na (S7: Yes), the process returns. That is, an evaluation process is performed on the workpiece W (S1). Therefore, if the degree of goodness is determined to be "high," the interval of the evaluation process becomes the first set number of operations Na.

[0091] If the degree of goodness is "low" in S4 (S4: No), the timing of the evaluation process is set to a second set number of times Nb (S8). The second set number of times Nb is set to a number that is smaller than the first set number of times Na. Next, the number of grinding processes N since the previous evaluation process is obtained (S9). Then, it is determined whether the number of grinding processes N has reached the second set number of times Nb (S10). If the number of grinding processes N has not reached the second set number of times Nb (S10: No), the process of S9 is performed and the process is repeated.

[0092] In S10, if the number of grinding operations N reaches the second set number of times Nb (S10: Yes), the process returns. That is, an evaluation process is performed on the workpiece W (S1). Therefore, if the degree of goodness is determined to be "low," the interval of the evaluation process becomes the second set number of times Nb.

[0093] In this way, when the evaluation result is good and the degree of goodness is high, the machining state evaluation device 4 sets a larger number of grinding times for the workpiece from the previous evaluation process until the next evaluation process, compared to when the degree of goodness is low. In cases where the machining state evaluation device 4 performs evaluation process after the grinding cycle of the workpiece W is completed, performing evaluation process on all workpieces W may lengthen the cycle time. In such cases, this embodiment is effective. Furthermore, since the calculation load on the machining state evaluation device 4 can be reduced, it is highly useful for executing other processes, for example.

[0094] (Embodiment 3) The grinding system 1 of the third embodiment will be described with reference to Fig. 5. The grinding system 1 of the present embodiment differs from the grinding system 1 of the embodiment only in the PLC 31 of the control device 30.

[0095] Note that, among the symbols used in the third and subsequent embodiments, the same symbols as those used in the previous embodiments represent the same components, etc. as those in the previous embodiments, unless otherwise specified.

[0096] The PLC 31 of the present embodiment includes a signal acquisition unit 41, an evaluation item setting unit 42, an evaluation signal acquisition determination unit 44, and an output unit 45. The PLC 31 of the present embodiment does not include the evaluation item validity determination unit 43 that constitutes the PLC 31 of the first embodiment. The other components 41, 42, 44, and 45 are the same as those of the first embodiment. The grinding system 1 of the third embodiment achieves the same effects as the grinding system 1 of the first embodiment, except for the part related to the evaluation item validity determination unit 43 of the first embodiment.

[0097] (Embodiment 4) The grinding system 1 of the fourth embodiment will be described with reference to Figures 6 and 7. The grinding system 1 of the present embodiment differs from the grinding system 1 of the first embodiment in the PLC 31 of the control device 30.

[0098] The PLC 31 includes a signal acquiring unit 51, an evaluation result determining unit 52, and an output unit 53. The PLC 31 does not include the evaluation item setting unit 42 that constitutes the PLC 31 of the first embodiment. Therefore, the signal acquiring unit 51 acquires evaluation signals S for all evaluation items from the machining state evaluating device 4. However, the signal acquiring unit 51 does not acquire the evaluation result "good", but acquires other evaluation results such as "bad", "warning", and "failure". Note that the machining state evaluating device 4 can be set not to output the evaluation signal S for the evaluation result "good", and the signal acquiring unit 51 can also be set not to acquire the evaluation signal S for the evaluation result "good".

[0099] The evaluation result determination unit 52 determines whether or not an evaluation result other than "good" such as "poor," "warning," or "failure" has been obtained based on the evaluation signal S acquired by the signal acquisition unit 51. If the evaluation result determination unit 52 has acquired the evaluation result of "poor," "warning," or "failure," it determines "Yes," and if it has not acquired any evaluation result, it determines "No."

[0100] The output unit 53 includes a symptom management processing unit 53a and a count management processing unit 53b. When the evaluation result determination unit 52 acquires the evaluation result of "bad," "warning," or "failure," the symptom management processing unit 53a executes symptom management processing in the output unit 53. The symptom management processing unit 53a executes symptom management processing to output a symptom management command R3 to the CNC device 32. On the other hand, if the evaluation result determination unit 52 does not obtain any evaluation results, the output unit 53 performs a count management process using the count management processing unit 53b. The count management process is the same as the count management process in the first embodiment.

[0101] The symptom management command R3 will be described with reference to Fig. 7. The symptom management command R3 includes a first command R31, a second command R32, and a third command R33. The first command R31, the second command R32, and the third command R33 are similar to the second command R12, the third command R13, and the fourth command R14 in the first embodiment. This embodiment also achieves the same effects as the first embodiment. [Explanation of symbols]

[0102] 1 Grinding system 4. Processing status evaluation device 10 Grinding machine body 30 Control device T grinding wheel W Workpiece S Evaluation signal

Claims

1. a grinding machine body that performs grinding on a workpiece using a grinding wheel; an observation device provided on the grinding machine body for detecting measurement data observed during grinding in order to observe a processing state of the workpiece during grinding by the grinding machine body; a control device that counts the number of grinding processes that indicates the number of times the grinding process has been performed by the grinding machine body and controls the operation of the grinding machine body; a machining state evaluation device that performs evaluation processing for evaluation items related to the machining state when the grinding machine main body grinds the workpiece based on the measurement data detected by the observation device, and outputs evaluation signals related to the evaluation results of the evaluation items to the control device; Equipped with the machining state evaluation device is set to perform the evaluation process for each grinding cycle, The control device When the evaluation signal can be acquired from the processing state evaluation device, if the evaluation result of the evaluation signal acquired from the processing state evaluation device indicates that a sign of deterioration in the grinding processing state by the grinding wheel has occurred, a sign management process is performed to cause the grinding machine main body to perform a correction process for the grinding wheel; a grinding system that, when the evaluation signal cannot be acquired from the processing state evaluation device despite being set to acquire the evaluation signal from the processing state evaluation device, performs a number management process that causes the grinding machine main body to perform the correction process on the grinding wheel when the number of grinding processes reaches a specified number.

2. The grinding system according to claim 1 , wherein the correction process is a dressing operation for dressing the grinding wheel.

3. the machining state evaluation device is configured to perform the evaluation process for a plurality of evaluation items related to the machining state, The control device The evaluation items to be acquired from the processing state evaluation device are set among the plurality of evaluation items, When the evaluation signal relating to the evaluation result of the set evaluation item can be acquired from the processing state evaluation device, the symptom management process is performed based on the evaluation result of the evaluation signal acquired from the processing state evaluation device; 3. The grinding system according to claim 1, wherein the number management process is performed when the evaluation signal relating to the evaluation result of the set evaluation item cannot be obtained from the machining state evaluation device.

4. The grinding system according to claim 3 , wherein the control device further performs the number of times management process when all of the evaluation items are set to be unnecessary.

5. The symptom management process includes: If the evaluation result is good, the correction process is not performed; If the evaluation result indicates that a sign of deterioration in the grinding state by the grinding wheel has occurred, the correction process is carried out; A grinding system according to any one of claims 1 to 4, wherein grinding of the workpiece by the grinding machine body is stopped when the evaluation result is poor or when the evaluation result fails the evaluation process.

6. The grinding system according to any one of claims 1 to 5, wherein the control device performs the correction process when a state occurs in which the evaluation signal cannot be acquired from the machining state evaluation device while the number of grinding operations exceeds the specified number of times after performing the symptom management process.

7. The grinding system according to any one of claims 1 to 6, wherein the processing state evaluation device performs the evaluation process for at least one of the evaluation items: presence or absence of chatter that occurs during grinding, the magnitude of the chatter, presence or absence of grinding burns that occur on the workpiece during grinding, surface roughness of the ground surface of the workpiece, and the shape of the workpiece due to grinding.

8. 8. The grinding system according to claim 1, wherein the control device further instructs an external device to perform the number of times management process when the number of times management process is to be performed.

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