Control method and apparatus for surface grinding.

Abstract

The present invention provides a control method and apparatus for surface grinding, which enable high-precision machining and improve machining efficiency. [Solution] A control method for surface grinding, comprising: a current value acquisition step S30 for acquiring the drive current value of a wheel drive motor that rotates the grinding wheel; a current value feature analysis step S40 for generating current value change trend data by analyzing the rise and fall change characteristics of the drive current value acquired in the current value acquisition step; a grinding condition evaluation step S50 for evaluating grinding conditions based on the current value change trend data generated in the current value feature analysis step and grinding processing data stored in a database; and a grinding condition optimization step S60 for generating grinding condition optimization data for optimizing grinding conditions based on the evaluation results of the grinding conditions evaluated in the grinding condition evaluation step, wherein grinding is performed based on the grinding condition optimization data generated in the grinding condition optimization step.

Description

[Technical Field]

[0001] The present invention relates to a control method for surface grinding and a surface grinding apparatus, and particularly to a control method for surface grinding and a surface grinding apparatus that allow suitable adjustment of grinding conditions even by unskilled operators. [Background Art]

[0002] Conventionally, there are surface grinding apparatuses that move a rotating grinding wheel relative to a workpiece and grind a processing surface of the workpiece with the rotating grinding wheel. In this type of surface grinding apparatus, it is known to detect a grinding load applied by the grinding wheel and adjust grinding conditions such as the depth of cut of the grinding wheel, feed rate, and dressing conditions based on the detected grinding load.

[0003] For example, Patent Document 1 discloses a surface grinding method in which when surface-grinding a workpiece with a grinding wheel, while monitoring the grinding load, the cutting speed of the grinding wheel is decreased when the grinding load rises to a predetermined load threshold, and the cutting speed of the grinding wheel is increased when the grinding load drops to the predetermined load threshold.

[0004] Further, for example, Patent Document 2 discloses a numerically controlled grinding apparatus that grinds a workpiece by controlling the relative movement speed between a grinding wheel and the workpiece via numerical control, the apparatus comprising load output means that detects and outputs a load applied by the grinding wheel to the workpiece. The numerically controlled grinding apparatus disclosed in said document corrects a speed value that specifies the relative movement speed between the grinding wheel and the workpiece based on the load value output by the load output means, and comprises control means that controls the grinding wheel to grind the workpiece using the obtained corrected speed value. [Prior Art Documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Unexamined Patent Publication No. 2017-56516 [Patent Document 2] Japanese Patent Publication No. 2018-24040 [Overview of the project] [Problems that the invention aims to solve]

[0006] To perform high-precision grinding accurately and efficiently with a surface grinding machine, it is necessary to appropriately set grinding conditions such as the depth of cut of the grinding wheel, feed rate, and dressing conditions to correspond to the shape and material of the grinding wheel and workpiece. Providing appropriate grinding conditions to the surface grinding machine for high-precision and high-efficiency grinding requires the experience and knowledge of skilled operators.

[0007] In the conventional surface grinding control method and surface grinding apparatus described above, it is known that the grinding load from the grinding wheel is detected and the grinding conditions are adjusted based on that grinding load. However, the conventional surface grinding control method and surface grinding apparatus had areas that needed improvement in order to perform high-precision grinding with high efficiency.

[0008] For example, in the conventional technology disclosed in Patent Documents 1 and 2, which involves detecting the grinding load value and correcting the cutting speed of the grinding wheel based on that value, it is difficult to calculate the optimal grinding conditions.

[0009] Specifically, the grinding load value can fluctuate even with slight changes in the material, shape, or processing conditions of the grinding wheel or workpiece. Therefore, it is difficult to accurately evaluate the grinding conditions based on the absolute value of the detected grinding load and its relationship to predetermined thresholds or reference values, and thus it is impossible to determine the optimal grinding conditions.

[0010] Therefore, with conventional surface grinding equipment, determining the optimal grinding conditions required repeated trial and error during actual grinding. This placed a significant burden on operators, especially those without much practical experience or knowledge. Consequently, there is a need to enable high-precision and highly efficient grinding processes to streamline the machining work.

[0011] The present invention has been made in view of the above circumstances, and its object is to provide a control method and a surface grinding apparatus that enable high-precision machining and improve machining efficiency. [Means for solving the problem]

[0012] The present invention provides a control method for surface grinding, which involves grinding a workpiece with a rotating grinding wheel, and comprises: a current value acquisition step of acquiring a drive current value of a grinding wheel drive motor that rotates the grinding wheel; a current value feature analysis step of analyzing the rise and fall change characteristics of the drive current value acquired in the current value acquisition step to generate current value change trend data; a grinding condition evaluation step of evaluating grinding conditions based on the current value change trend data generated in the current value feature analysis step and grinding processing data stored in a database; and a grinding condition optimization step of generating grinding condition optimization data to optimize the grinding conditions based on the evaluation results of the grinding conditions evaluated in the grinding condition evaluation step, wherein grinding is performed based on the grinding condition optimization data generated in the grinding condition optimization step.

[0013] Furthermore, the surface grinding apparatus of the present invention comprises a grinding wheel that rotates to grind a workpiece, a grinding wheel drive motor that rotates the grinding wheel, a current detection device that detects the drive current value of the grinding wheel drive motor, a control device that controls the grinding process of the workpiece by the grinding wheel, and a database that stores grinding process data including information on grinding conditions and grinding results. The control device analyzes the rise and fall characteristics of the drive current value acquired by the current detection device to generate current value change trend data, evaluates the current value change trend data and the grinding process data stored in the database to evaluate the current value change trend data and generates grinding condition optimization data to optimize the grinding conditions based on the evaluation results of the grinding conditions, and controls the grinding process based on the grinding condition optimization data. [Effects of the Invention]

[0014] The control method for surface grinding of the present invention comprises: a current value acquisition step of acquiring the drive current value of a grinding wheel drive motor that rotates the grinding wheel; a current value feature analysis step of analyzing the rise and fall change characteristics of the drive current value acquired in the current value acquisition step to generate current value change trend data; a grinding condition evaluation step of evaluating the grinding conditions based on the current value change trend data generated in the current value feature analysis step and the grinding processing data stored in the database; and a grinding condition optimization step of generating grinding condition optimization data to optimize the grinding conditions based on the evaluation results of the grinding conditions evaluated in the grinding condition evaluation step. Grinding is performed based on the grinding condition optimization data generated in the grinding condition optimization step. As a result, even operators with little experience or knowledge can efficiently and accurately set and adjust suitable grinding conditions, enabling high-precision and high-efficiency surface grinding. Therefore, in the production of various processed products, the time required for surface grinding can be shortened and productivity can be increased.

[0015] Furthermore, in the control method for surface grinding according to the present invention, the grinding conditions and the data for optimizing the grinding conditions may include at least one of the cutting depth, feed rate, and feed rate of the grinding wheel. This allows even operators with little experience or knowledge to set suitable grinding conditions, enabling high-precision and high-efficiency grinding.

[0016] Furthermore, in the control method for surface grinding of the present invention, the grinding condition optimization data may be generated such that, when a change characteristic is confirmed in the current value change trend data in which the drive current value rises above a predetermined rate of increase or falls below a predetermined rate of decrease, at least one of the depth of cut, the feed rate, and the feed rate is increased or decreased based on the grinding data. This makes it possible to perform high-precision and high-efficiency grinding with suitable grinding conditions.

[0017] Furthermore, in the control method for surface grinding of the present invention, the grinding condition optimization data generated in the grinding condition optimization step is displayed on the display unit, and the grinding process may be performed based on the grinding condition optimization data displayed on the display unit, which is input from the operation unit. As a result, even operators with little experience or knowledge can input suitable grinding conditions by referring to the grinding condition optimization data displayed on the display unit, enabling highly accurate and efficient grinding.

[0018] Furthermore, in the control method for surface grinding according to the present invention, the grinding conditions and the data for optimizing the grinding conditions may also include dressing conditions for dressing the grinding surface of the grinding wheel. This allows for efficient dressing of the grinding wheel at a suitable interval, enabling high-precision and highly efficient grinding.

[0019] Furthermore, the surface grinding apparatus of the present invention comprises a grinding wheel that rotates to grind a workpiece, a grinding wheel drive motor that rotates the grinding wheel, a current detection device that detects the drive current value of the grinding wheel drive motor, a control device that controls the grinding process of the workpiece by the grinding wheel, and a database that stores grinding process data including information on grinding conditions and grinding results. The control device analyzes the rise and fall characteristics of the drive current value acquired by the current detection device to generate current value change trend data, evaluates the current value change trend data and the grinding process data stored in the database to evaluate the current grinding conditions of the current grinding process, generates grinding condition optimization data to optimize the grinding conditions based on the evaluation result of the grinding conditions, and controls the grinding process based on the grinding condition optimization data. As a result, even operators with little experience or knowledge can efficiently and accurately set and adjust suitable grinding conditions, enabling highly accurate and efficient surface grinding. Therefore, in the production of various processed products, the time required for surface grinding can be shortened, thereby increasing productivity.

[0020] Further, the surface grinding apparatus of the present invention comprises a feed mechanism that moves the workpiece or the grinding wheel such that the workpiece and the grinding wheel move relative to each other, wherein the grinding conditions and the grinding condition optimization data include at least one of a cutting depth, a feed amount and a feed rate of the grinding wheel, and the control device may control the feed mechanism based on the grinding condition optimization data to control at least one of the cutting depth, the feed amount and the feed rate. This enables a worker with little experience or knowledge to perform highly accurate and highly efficient grinding.

[0021] Further, in the surface grinding apparatus of the present invention, the grinding condition optimization data may be generated such that when a change characteristic that the drive current value increases exceeding a predetermined increase rate or decreases exceeding a predetermined decrease rate is confirmed in the current value change tendency data, at least one of the cutting depth, the feed amount and the feed rate is increased or decreased based on the grinding processing data. This enables highly accurate and highly efficient grinding to be performed with suitable grinding condition settings.

[0022] Further, the surface grinding apparatus of the present invention comprises a display unit that displays the grinding condition optimization data, and an operation unit that inputs the grinding condition optimization data displayed on the display unit, wherein the control device may control the grinding processing based on the grinding condition optimization data input to the operation unit. This enables a worker with little experience or knowledge to input suitable grinding conditions with reference to the grinding condition optimization data displayed on the display unit, and perform highly accurate and highly efficient grinding.

[0023] Further, the surface grinding apparatus of the present invention comprises a dressing device that dresses the grinding surface of the grinding wheel, wherein the grinding conditions and the grinding condition optimization data include dressing conditions by the dressing device, and the control device may control the dressing device based on the grinding condition optimization data. This enables efficient dressing of the grinding wheel at suitable intervals, and performs highly accurate and highly efficient grinding. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] [Figure 1] It is a diagram showing a schematic configuration of a surface grinding device according to an embodiment of the present invention. [Figure 2] It is a diagram showing an outline of a control system of a surface grinding device according to an embodiment of the present invention. [Figure 3] It is a flow diagram showing an outline of a control process for grinding performed by a surface grinding device according to an embodiment of the present invention. [Figure 4] It is a flow diagram showing an outline of a step of storing grinding processing data of a surface grinding device according to an embodiment of the present invention. [Figure 5] It is a flow diagram showing an outline of a step of displaying grinding condition data and the like of a surface grinding device according to an embodiment of the present invention. [Figure 6] It is a flow diagram showing an example of a step of performing grinding condition evaluation and grinding condition optimization for a surface grinding device according to an embodiment of the present invention. [Figure 7] It is a diagram showing an example of current value change trend data of a surface grinding device according to an embodiment of the present invention. [Figure 8] It is a diagram showing another example of current value change trend data of a surface grinding device according to an embodiment of the present invention. [Figure 9] It is a diagram showing another example of current value change trend data of a surface grinding device according to an embodiment of the present invention. [Figure 10] It is a flow diagram showing another example of a step of performing grinding condition optimization for a surface grinding device according to an embodiment of the present invention. DETAILED DESCRIPTION OF EMBODIMENTS

[0025] Hereinafter, a control method for surface grinding and a surface grinding device according to an embodiment of the present invention will be described in detail with reference to the drawings. Figure 1 is a diagram showing a schematic configuration of a surface grinding device 1 according to an embodiment of the present invention.

[0026] As shown in Figure 1, the surface grinding apparatus 1 comprises a CNC (Computerized Numerical Control) surface grinding machine 2 for grinding the workpiece surface W, and a control device 3 for automatic numerical control of the CNC surface grinding machine 2.

[0027] The CNC surface grinding machine 2 has a grinding wheel 10 as a tool for grinding the workpiece W, and a table 12 as a workpiece support means for supporting the workpiece W, and grinds the upper surface of the workpiece W, which is the workpiece surface, with the rotating grinding wheel 10.

[0028] More specifically, the grinding wheel 10 is rotationally driven by the grinding wheel drive motor 31, and the circumferential end of the rotating grinding wheel 10 contacts the upper surface of the workpiece W, thereby grinding the upper surface of the workpiece W into a substantially flat shape. The CNC surface grinding machine 2 may be, for example, a CNC form grinding machine capable of grinding complex shapes or other types of grinding machines.

[0029] The table 12 is configured to reciprocate freely in the left-right horizontal direction (X direction) when viewed from the front. The grinding wheel 10 is supported by a grinding wheel shaft head 11, which is a tool support means that can reciprocate freely in the up-down direction (Y direction). The grinding wheel shaft head 11 that supports the grinding wheel 10 is supported by a column 13 that is configured to reciprocate freely in the front-back horizontal direction (Z direction), that is, in a direction approximately perpendicular to the plane of the paper in Figure 1.

[0030] The table 12 supporting the workpiece W is, for example, an electromagnetic chuck equipped with an electromagnet or the like, which can support the placed workpiece W by magnetic force to prevent it from moving. The grinding wheel 10 supported on the grinding wheel head 11 and the workpiece W supported on the table 12 are fed by a feed mechanism (not shown, described later with reference to Figure 2) numerically controlled by the control device 3, and move back and forth in the aforementioned directions.

[0031] The CNC surface grinding machine 2 may be provided with left and right handles 26, front and rear handles 27, and up and down handles 28 as operating means that allow the operator to move the grinding wheel 10 and the workpiece W relative to each other. The up and down handles 28 may be provided on the control panel 16, which will be described later.

[0032] The grinding area where the grinding wheel 10 and table 12 are positioned is covered by a cover 14. The front and top surfaces of the cover 14 are open to allow the operator to set and remove the workpiece W. A door (not shown) that can be opened and closed may be provided in this opening.

[0033] Figure 2 is a diagram illustrating the control system of the surface grinding machine 1. Referring to Figures 1 and 2, the CNC surface grinding machine 2 has a current detection device 25 that detects the load current, i.e., the drive current value, of the grinding wheel drive motor 31 that rotates the grinding wheel 10.

[0034] The current detection device 25 is connected to the control device 3. As a result, the drive current value of the grinding wheel drive motor 31 detected by the current detection device 25 is sent to the control device 3 and used as data to control the grinding process by the grinding wheel 10.

[0035] The control device 3 is connected to the left and right handles 26, the front and rear handles 27, and the up and down handles 28 in a communication manner. As a result, the control device 3 can control the grinding process based on the operator's input from the left and right handles 26, the front and rear handles 27, and the up and down handles 28.

[0036] The control device 3 is a control means for controlling the grinding process of the workpiece W by the grinding wheel 10, and includes a control panel 15, an operation panel 16, a calculation device 20, and a database 23. The control panel 15, operation panel 16, calculation device 20, and database 23 are connected by wired or wireless connections to enable information communication, and may be connected via, for example, an internet connection. Alternatively, the control panel 15, operation panel 16, calculation device 20, and database 23 may be configured as an integrated control unit housed inside a single casing or the like (not shown).

[0037] The control panel 15 is installed, for example, inside the main body of the CNC surface grinding machine 2 and is connected to the grinding wheel drive motor 31, table feed device 32, grinding wheel forward / backward feed device 33, grinding wheel up / down feed device 34, dressing device 35, and grinding fluid supply device 36, and controls these devices.

[0038] The control panel 15 is connected to an operation panel 16 on which the operator performs various operations for grinding. The operation panel 16 is equipped with an operation unit 17, which is an operating means for the operator to input grinding conditions including various processing information, and a display unit 18 that displays the grinding conditions.

[0039] The operation unit 17 consists of various switches, buttons, etc., for inputting grinding conditions. The display unit 18 is a monitor, display, etc., that shows grinding conditions, processing conditions, etc. Alternatively, the display unit 18 may be a touchscreen that can be used as the operation unit 17 for input.

[0040] The grinding conditions input from the operation unit 17 and displayed on the display unit 18 include, for example, the depth of cut of the grinding wheel 10 by the grinding wheel vertical feed device 34 (Y-direction movement), the forward and backward feed amount (Z-direction movement) and forward and backward feed speed (Z-direction movement speed) by the grinding wheel forward and backward feed device 33, and the left and right feed speed (X-direction movement speed) by the table feed device 32.

[0041] Furthermore, the grinding conditions input from the operation unit 17 and displayed on the display unit 18 include grinding information such as the grit size, material, dimensions, position information and rotational speed of the grinding wheel 10, the processing dimensions, material, and position information of the workpiece W, grinding patterns such as shift plunge and traverse, and dressing information from the dressing device 35.

[0042] Furthermore, the control unit 17 may be equipped with, for example, a start button for the operator to input instructions for detecting the workpiece W and starting the grinding process, a pause button for inputting instructions to temporarily stop the process, and an emergency stop button for inputting instructions to completely stop the process.

[0043] The calculation unit 20 is an electronic computer that performs various calculations for grinding, and may be, for example, a computer, a tablet terminal, or other portable dedicated operating device. The calculation unit 20 is equipped with an operation unit 21 for the operator to input grinding conditions, etc., and a display unit 22 for displaying the grinding conditions, etc.

[0044] For example, the operation unit 21 may be a keyboard, touchscreen, voice input device, image input device, or other various input devices. The display unit 22 may be a display, touchscreen, etc., or it may be a voice output device, etc.

[0045] Database 23 is a storage device, such as a server, that stores and manages grinding process data, including information on grinding conditions and grinding results, and various other data. Database 23 records grinding process data, for example, linking grinding conditions with the conditions of the processing results resulting from those grinding conditions.

[0046] Furthermore, an information and communication terminal 24 may be provided as a component of the control device 3. The information and communication terminal 24 may be a portable information and communication device such as a smartphone or tablet, and may be connected via wired or wireless connection to the control panel 16, the computing device 20, and the database 23, etc., via the internet or the like.

[0047] Furthermore, the CNC surface grinding machine 2 is equipped with various sensors 29 that acquire data related to the grinding wheel 10, the workpiece W, and other grinding processes. These sensors 29 are connected to the control device 3 via wired or wireless connection for information communication.

[0048] The various sensors 29 include, for example, contact-type sensors having probes and contacts for detecting the position of the grinding wheel 10 and workpiece W, non-contact sensors such as air sensors, AE (Acoustic Emission) sensors having piezoelectric elements for detecting vibration, current sensors, voltage sensors, pressure sensors, and other various sensors for detecting the load of various drive devices.

[0049] Furthermore, the CNC surface grinder 2 is equipped with various switches 30 for inputting grinding conditions and other operational information related to the grinding process, and these switches 30 are connected to the control device 3 via wired or wireless connection for information communication.

[0050] Furthermore, the CNC surface grinder 2 has a grinding fluid supply device 36 that supplies grinding fluid to the grinding wheel 10 or the workpiece W during grinding. The pump, valves, etc. that make up the grinding fluid supply device 36 are connected to the control device 3 and may be controlled by the control device 3 based on the grinding conditions described above.

[0051] Next, with reference to Figures 3 to 10, the control method for the grinding process performed by the surface grinding apparatus 1 will be explained in detail. Figure 3 is a flowchart illustrating the control process for grinding using the surface grinding machine 1.

[0052] Referring to Figures 1 to 3, in the grinding process using the surface grinding apparatus 1, first, in step S10, the operator registers the grinding conditions, which are various conditions necessary for the grinding process.

[0053] Specifically, the operator operates the control panel 17 of the control panel 16 of the CNC surface grinding machine 2, for example, and inputs grinding conditions using interactive software or the like. Here, the grinding conditions are displayed on the display panel 18 of the control panel 16, so the operator can accurately confirm the entered grinding conditions visually. The grinding conditions entered by the operator are then transferred from the control panel 16 to the calculation unit 20.

[0054] Next, in step S20, the automatic grinding cycle is started. Specifically, the automatic grinding cycle is started by the operator operating the control unit 17, etc.

[0055] When grinding begins, control is executed from the control panel 15 of the control device 3, and the grinding wheel 10 is driven to rotate at a predetermined speed by the grinding wheel drive motor 31. Then, the table feed device 32, grinding wheel forward / backward feed device 33, and grinding wheel up / down feed device 34, which are automatically controlled by the control panel 15, move the grinding wheel 10 and the workpiece W to predetermined relative positions. An automatic grinding cycle is then executed in which the workpiece surface is ground with the rotating grinding wheel 10.

[0056] Next, during the automatic grinding process, a current value acquisition process S30, indicated as step S30, is performed. In the current value acquisition process S30, the drive current value of the grinding wheel drive motor 31, which rotates the grinding wheel 10, is acquired by the current detection device 25. The measurement data of the drive current value acquired by the current detection device 25 is sent to the calculation device 20 of the control device 3.

[0057] When measurement data of the drive current value that rotates the grinding wheel 10 is sent to the calculation unit 20, the current value characteristic analysis step S40 shown in step S40 is performed. Specifically, the calculation unit 20 analyzes the rise and fall change characteristics of the drive current value in the current value characteristic analysis step S40 based on the measurement data of the drive current value acquired by the current detection device 25 in the current value acquisition step S30, and generates current value change trend data.

[0058] The current value change trend data may include, for example, image information data in which the change characteristics of the drive current value measured by the current detection device 25 are converted into image data by the calculation device 20.

[0059] Furthermore, the current value change trend data may be displayed as image information on the display unit 18 of the control panel 16, the display unit 22 of the calculation unit 20, etc. This allows the operator to visually confirm and clearly understand the grinding process status as graphical image information.

[0060] Once current value change trend data is generated in the current value feature analysis step S40, the grinding condition evaluation step S50 is performed as step S50 to evaluate the grinding conditions. Specifically, in the grinding condition evaluation step S50, the calculation unit 20 evaluates the grinding conditions based on the current value change trend data generated in the current value feature analysis step S40 and the grinding processing data stored in the database 23.

[0061] Furthermore, the evaluation results of the grinding conditions in the grinding condition evaluation process S50 may also be displayed as textual or image information on the display unit 18 of the control panel 16, the display unit 22 of the calculation device 20, etc. This allows the operator to know the status of the grinding process and whether the current grinding conditions are appropriate.

[0062] After the grinding condition evaluation step S50 is executed, the grinding condition optimization step S60 is then performed as step S60, which optimizes the grinding conditions. In the grinding condition optimization step S60, the calculation unit 20 generates grinding condition optimization data to optimize the grinding conditions based on the evaluation results of the grinding conditions evaluated in the grinding condition evaluation step S50.

[0063] Specifically, the grinding condition optimization data is a new grinding condition that has been corrected and optimized based on the current grinding conditions registered in step S10, the current value change trend data generated in the current value characteristic analysis step S40, the evaluation results of the grinding conditions evaluated in the grinding condition evaluation step S50, and the grinding processing data stored in the database 23.

[0064] Next, in step S80, the grinding condition optimization data generated in the grinding condition optimization step S60 may be displayed as text information or image information on the display unit 18 of the control panel 16, the display unit 22 of the calculation device 20, etc. This allows the operator to clearly grasp the current grinding status, the ease of optimizing the grinding conditions, and the information of the grinding condition optimization data by visual inspection.

[0065] Thus, with the surface grinding apparatus 1, even operators with little experience or knowledge can efficiently and accurately set and adjust optimal grinding conditions, enabling high-precision and highly efficient surface grinding. Therefore, in the production of various processed products, the time required for surface grinding can be reduced, thereby increasing productivity.

[0066] Figure 4 is a flowchart illustrating the general process for storing grinding data of the surface grinding machine 1. In Figure 4, steps that have the same or similar function and effect as those shown in Figure 3 are denoted by the same reference numerals, and their detailed explanations are omitted.

[0067] Referring to Figures 1 and 4, the current value change trend data generated in the current value feature analysis step S40 may be stored in the database 23 in step S41. As described above, the current value change trend data stored in the database 23 may include image information data in which the change characteristics of the drive current value acquired by the current detection device 25 are converted into image data by the calculation device 20.

[0068] In step S41, grinding condition data may also be saved in the database 23 along with the current value change trend data. The grinding condition data saved in the database 23 is the data of the current grinding conditions registered in step S10.

[0069] Then, when the grinding process is completed, in step S51, the information of the workpiece W after processing is registered as grinding data. Specifically, grinding data including the finished dimensional accuracy and surface roughness of the workpiece W's processed surface, and the dimensions, surface roughness, and abrasive grain condition of the grinding wheel 10's processed surface, may be confirmed and measured by the operator and input from the operation section 17 of the control panel 16, etc.

[0070] Furthermore, grinding data such as the coordinates and dimensions of the workpiece surface W and the dimensions of the grinding surface of the grinding wheel 10 may be automatically measured by various sensors 29 (see Figure 2), such as a position sensor, and stored in the control panel 16 or the like.

[0071] When grinding data is registered in the control panel 16, etc. in step S51, the grinding data is sent from the control panel 16, etc. to the database 23 in step S52 and stored in the database 23.

[0072] In this way, the database 23 stores linked information including grinding conditions, data on the trend of current value changes during grinding, and grinding data after grinding. As a result, in the grinding condition evaluation step S50 (see Figure 3), the grinding conditions can be evaluated based on the grinding data stored in the database 23.

[0073] Furthermore, in the grinding condition optimization process S60 (see Figure 3), grinding condition optimization data can be generated based on the grinding condition data stored in the database 23. Therefore, the surface grinding apparatus 1 can perform grinding with high precision and high efficiency.

[0074] Figure 5 is a flowchart illustrating the general process for displaying grinding condition data for the surface grinding apparatus 1. In Figure 5, steps that have the same or similar function or effect as those shown in Figure 3 are denoted by the same reference numerals.

[0075] Referring to Figures 1 and 5, once the grinding conditions are registered in step S10, in step S11, the calculation unit 20 of the control device 3 searches for similar grinding condition data that is similar to the newly registered grinding conditions from the grinding condition data stored in the database 23.

[0076] The calculation unit 20 then reads similar grinding condition data that are similar to the newly registered grinding conditions, as well as grinding processing data that is linked to and stored with the similar grinding condition data, from the database 23.

[0077] Next, in step S12, the similar grinding condition data and grinding process data read from the database 23 may be displayed on the display unit 22 of the calculation unit 20. Alternatively, the similar grinding condition data, etc., read from the database 23 may be transmitted from the calculation unit 20 to the control panel 16 and displayed on the display unit 18 of the control panel 16.

[0078] In this case, the similar grinding condition data may not be just one data point, but multiple data points. For example, multiple similar grinding condition data points may be read from database 23 and displayed in order of similarity.

[0079] Next, in step S13, the operator can check similar grinding condition data displayed on the display unit 22 or the display unit 18, etc., and choose whether or not to modify the registered grinding conditions.

[0080] If it is selected in step S13 to modify the grinding conditions (YES in step S13), the process proceeds to step S14, where the modified grinding conditions are registered. Specifically, the operator can select the grinding conditions that need modification and input the modified new grinding conditions by operating the control panel 17 on the control panel 16. The control process then proceeds to step S11, where a search for similar grinding condition data is performed.

[0081] On the other hand, if it is selected not to modify the grinding conditions in step S13 (NO in step S13), the process proceeds to step S20 and the automatic grinding cycle is started.

[0082] In this way, similar grinding condition data is searched from the grinding condition data and grinding process data stored in the database 23 and displayed on the display unit 18, etc., making it possible for even operators with little experience or knowledge to set suitable grinding conditions. Therefore, high-precision and highly efficient grinding can be performed.

[0083] Figure 6 is a flowchart showing an example of the process for evaluating and optimizing the grinding conditions of the surface grinding apparatus 1. Referring to Figures 1, 2, and 6, the grinding condition evaluation process S50 is executed, and after the grinding processing data is registered in step S51, in step S53, the control device 3 determines whether or not the grinding results are good.

[0084] If the grinding results are determined to be poor (NO in step S53), the process proceeds to step S63, where data for optimizing the grinding conditions is generated to loosen the grinding conditions. For example, data for optimizing the grinding conditions is generated to reduce at least one of the following: the depth of cut of the grinding wheel 10 by the grinding wheel vertical feed device 34, the forward and backward feed amount and forward and backward feed speed by the grinding wheel forward and backward feed device 33, and the left and right feed speed by the table feed device 32.

[0085] On the other hand, if it is determined in step S53 that the grinding results are good (YES in step S53), the control process proceeds to step S54, where it is determined whether the current value change trend data has characteristics of an upward waveform that exceeds a predetermined rate of increase.

[0086] In step S54, if the current value change trend data shows an increase characteristic exceeding a predetermined rate of increase (YES in step S54), the process proceeds to step S62, where data for optimizing grinding conditions to tighten the grinding conditions is generated.

[0087] Specifically, grinding condition optimization data is generated to increase at least one of the following: the depth of cut of the grinding wheel 10 by the grinding wheel vertical feed device 34, the forward and backward feed amount and forward and backward feed speed by the grinding wheel forward and backward feed device 33, and the left and right feed speed by the table feed device 32.

[0088] On the other hand, if in step S54 no features of an upward waveform exceeding a predetermined rate of increase are observed in the current value change trend data (NO in step S54), the control process proceeds to step S55. In step S55, it is determined whether the current value change trend data has characteristics of a downward waveform that exceeds a predetermined rate of decline.

[0089] In step S55, if a decrease characteristic exceeding a predetermined decrease rate is confirmed in the current value change trend data (YES in step S55), the process proceeds to step S63, where grinding condition optimization data is generated to loosen the grinding conditions.

[0090] On the other hand, if, in step S55, no characteristic of a downward waveform exceeding a predetermined rate of decline is observed in the current value change trend data (NO in step S55), the control process proceeds to step S61, where the current grinding conditions are determined to be suitable and maintained.

[0091] Figure 7 shows an example of current value change trend data for the surface grinding machine 1. Figure 7(A) shows an example where the grinding conditions are evaluated as appropriate, Figure 7(B) shows an example where an upward trend in waveform change is observed, and Figure 7(C) shows an example where a downward trend in waveform change is observed. In Figure 7, the horizontal axis is time T and the vertical axis is current value A.

[0092] As described above, the evaluation of grinding conditions in the grinding condition evaluation step S50 (see Figure 3), and the generation of grinding condition optimization data in the grinding condition optimization step S60 (see Figure 3) are performed based on the characteristics of the waveform changes in the current value change trend data.

[0093] Specifically, the evaluation of grinding conditions and the generation of data for optimizing grinding conditions are performed based on the characteristics of the trend in the change of current value per pass, that is, in one grinding operation in which the workpiece W is sent from one end to the other, as shown in Figure 7(A).

[0094] For example, at the 1-pass determination time Tp during which one pass of grinding is performed, if the drive current value of the grinding wheel 10 (see Figure 1) displayed in the current value change trend data is within a predetermined rate of change, the grinding conditions are judged to be good.

[0095] Here, the rate of change in the current value change trend data is expressed, for example, as the ratio of the current value Ap2 at the end of grinding to the current value Ap1 at the start of grinding during the 1-pass determination time Tp in which one pass grinding is performed, i.e., current value Ap2 / current value Ap1.

[0096] Furthermore, the change characteristics of the current value change trend data may also be evaluated by the current value difference ΔAp between the current value Ap1 at the start of one grinding pass and the current value Ap2 at the end of the grinding pass.

[0097] In other words, when the current value Ap2 / current value Ap1 or the current value difference ΔAp is within a predetermined range, the grinding conditions are considered appropriate and the grinding process is evaluated as being performed well.

[0098] The change reference value that determines the predetermined range is determined by the current grinding conditions and the grinding condition data and grinding processing data stored in database 23 (see Figure 1). In other words, the change reference value is a predetermined reference condition determined according to the grinding conditions, which include the type of grinding wheel 10, the specifications of the workpiece W, the depth of cut, the feed rate, the feed rate, the grinding feed pattern, and other information.

[0099] For example, as shown in Figure 7(B), if the change characteristics of the current value change trend data per pass are on an upward trend and the current value rises beyond a predetermined rate of increase, then, as described above, in step S54 (see Figure 6), it is determined that the waveform has changed beyond a predetermined range of increase, and in step S62 (see Figure 6), control may be performed to tighten the grinding conditions.

[0100] For example, as shown in Figure 7(C), if the change characteristics of the current value change trend data per pass are on a downward trend and the current value falls beyond a predetermined rate of decrease, then, as described above, in step S55 (see Figure 6), it is determined that the current value has changed beyond a predetermined rate of decrease, and in step S63 (see Figure 6), control may be performed to tighten the grinding conditions.

[0101] Figure 8 shows another example of current value change trend data for the surface grinding machine 1. In Figure 8, the horizontal axis represents time T, and the vertical axis represents the current value A. Referring to Figure 8, the change characteristics of the current value change trend data may also be determined from the changes during grinding over multiple passes.

[0102] For example, during the determination time Ts in which multiple passes of grinding are performed, if the drive current value of the grinding wheel 10 (see Figure 1) displayed in the current value change trend data changes by more than a predetermined rate of change, it may be determined that the grinding conditions need to be optimized.

[0103] Here, the rate of change of the current value change trend data is expressed, for example, as the ratio of the current value As2 at the end of grinding to the current value As1 at the start of grinding during the determination time Ts in which a predetermined number of reference passes of grinding are performed, i.e., current value As2 / current value As1.

[0104] Furthermore, the change characteristics of the current value change trend data may be evaluated by the current value difference ΔAs between the current value As1 at the start of grinding and the current value As2 at the end of grinding for a predetermined set of multiple passes that serve as a reference.

[0105] For example, if the current value change trend data decreases continuously during multiple passes of grinding, and the current value As2 / current value As1 decreases beyond a predetermined range, or the current value difference ΔAs decreases beyond a predetermined range, i.e., decreases beyond a predetermined negative value, then, as described above, in step S55 (see Figure 6), it is determined that the current value has changed beyond a predetermined decrease range, and control to loosen the grinding conditions may be performed in step S63 (see Figure 6).

[0106] Figure 9 shows another example of the current value change trend data for the surface grinding machine 1. Figure 9(A) shows an example where a downward trend in waveform change is observed, and Figure 9(B) shows an example where an upward trend in waveform change is observed. In Figure 9, the horizontal axis represents time T, and the vertical axis represents the current value A. The same signs are used for the same values ​​as in Figure 8, which has already been explained.

[0107] Referring to Figures 9(A) and 9(B), the change characteristics of the current value change trend data are analyzed based on the determination time Ts during which multiple passes of grinding are performed, and may be used, for example, to optimize the dressing conditions of the grinding wheel 10 (see Figure 1).

[0108] In other words, the grinding conditions include dressing conditions for dressing the grinding surface of the grinding wheel 10, and in the grinding condition evaluation step S50 and the grinding condition optimization step S60 shown in Figure 3, for example, diagnosis and correction may be performed to optimize the dressing conditions such as the dressing interval.

[0109] Specifically, as shown in Figure 9(A), during the determination time Ts in which multiple passes of grinding are performed, if the drive current value of the grinding wheel 10 displayed in the current value change trend data decreases by more than a predetermined rate of decrease, grinding condition optimization data that lengthens the dressing interval may be generated.

[0110] Conversely, as shown in Figure 9(B), if, during the determination time Ts in which multiple passes of grinding are performed, the drive current value of the grinding wheel 10 displayed in the current value change trend data increases by more than a predetermined rate, grinding condition optimization data that shortens the dressing interval may be generated.

[0111] Furthermore, although not shown in the diagram, if a so-called "miss" occurs during dressing after grinding, where there is no contact between the grinding wheel 10 and the dresser, grinding condition optimization data may be generated in grinding condition optimization step S60 to shorten the dressing interval. Also, if a similar condition is detected, grinding condition optimization data may be generated to increase the dressing depth and dressing speed.

[0112] Conversely, in the dressing process after grinding, if it is determined in the grinding condition evaluation step S50 that no misfires occur, and the grinding conditions are for finish grinding, then the grinding conditions are judged to be appropriate, and the current grinding conditions may be maintained.

[0113] Furthermore, in the dressing process after grinding, if it is determined in the grinding condition evaluation step S50 that no misfires occur, and the grinding conditions are rough grinding, then it may be determined in the grinding condition evaluation step S50 that there is sufficient margin in the grinding conditions, and grinding condition optimization data may be generated in the grinding condition optimization step S60 to lengthen the dressing interval.

[0114] By optimizing the grinding conditions, including the dressing conditions, it is possible to perform appropriate dressing according to the degree of clogging or chipping of the grinding wheel 10, thereby enabling highly efficient grinding with minimal time loss while suppressing deterioration of the grinding performance of the grinding wheel 10.

[0115] Furthermore, in addition to current value change trend data, contact sensors such as AE sensors may be used to determine the dressing conditions.

[0116] Figure 10 is a flowchart showing another example of the process for optimizing the grinding conditions of the surface grinding apparatus 1. Referring to Figure 10, in the grinding condition optimization process S60, the grinding conditions may be optimized based on a pre-selected and registered processing mode.

[0117] Specifically, the grinding conditions include the processing mode conditions. For example, in step S10 (see Figure 3), when registering grinding conditions, the operator can select and register the processing mode for the grinding conditions from the control panel 16 (see Figure 1). More specifically, the operator can select a desired processing mode that suits the purpose of the grinding process from the processing modes displayed on the display unit 18 (see Figure 1) and register it from the control unit 17 (see Figure 1), etc.

[0118] For example, the processing modes may include a standard mode that prioritizes standard grinding accuracy and grinding efficiency, a high-power mode that prioritizes reducing grinding time and performs highly efficient grinding, a low-power mode that prioritizes preventing deterioration of the grinding wheel 10 (see Figure 1) and improving the precision of the grinding surface, and various other operating modes set according to different priority conditions, with multiple stages of processing modes.

[0119] Then, for example, in the grinding condition optimization process S60, step S65 determines whether the processing mode registered in the grinding conditions is the high-power mode. If the processing mode is the high-power mode (YES in step S65), the process proceeds to step S71, where control is performed to tighten the grinding conditions in the grinding condition optimization data.

[0120] On the other hand, if the processing mode of the registered grinding conditions is not high power mode (NO in step S65), the process proceeds to the next step S66, where it is determined whether or not the processing mode is low power mode.

[0121] In step S66, if it is determined that the machining mode is low power mode (YES in step S66), the process proceeds to step S72, where control is performed to loosen the grinding conditions in the grinding condition optimization data.

[0122] On the other hand, if it is determined in step S66 that the machining mode of the grinding conditions is not the low power mode (NO in step S66), the process proceeds to the next step S67, where it is determined whether or not other machining modes are registered.

[0123] If it is determined in step S67 that other machining modes are registered (YES in step S67), the process proceeds to step S77, where any other preset corrections are made to the grinding conditions.

[0124] On the other hand, if it is determined in step S67 that no other processing modes are registered (NO in step S67), the process proceeds to the next processing mode determination step (not shown). If no other processing modes requiring changes to the grinding conditions are registered, the control process proceeds to step S70, where the basic grinding conditions without processing mode-based correction are selected.

[0125] In this way, the operator can select a suitable machining mode according to the workpiece W (see Figure 1) to be machined, and the grinding condition optimization data is corrected according to the selected and registered machining mode, thereby enabling optimal grinding that conforms to the production target.

[0126] Furthermore, although the illustration of the current value change trend data is omitted, as shown in Figure 3, in the grinding condition evaluation step S50 and the grinding condition optimization step S60, control for optimizing spark out may be performed.

[0127] For example, if there is a large change in the load current value of the grinding wheel 10 (see Figure 1) in the current value change trend data due to spark out after grinding cut, the grinding condition evaluation step S50 may determine that the current grinding conditions are too severe, and grinding condition optimization data may be generated in the grinding condition optimization step S60 to loosen the grinding conditions.

[0128] Furthermore, for example, if the change in the load current value of the grinding wheel 10 in the current value change trend data is small after spark out following grinding cut, the grinding condition evaluation step S50 may determine that the current grinding conditions are good, and for example, if it is rough grinding, grinding condition optimization data may be generated in the grinding condition optimization step S60 to make the grinding conditions stricter.

[0129] As described above, the surface grinding apparatus 1 of the present invention allows even operators with little experience or knowledge to efficiently and accurately set and adjust suitable grinding conditions, enabling high-precision and highly efficient surface grinding. Therefore, it is possible to shorten the time required for surface grinding in the production of various processed products and increase productivity.

[0130] In particular, unlike conventional technologies that evaluate grinding based on whether the absolute value of the measured load current exceeds a predetermined threshold, the surface grinding apparatus 1 evaluates and optimizes grinding conditions using current value change trend data obtained by analyzing the characteristics of changes in the rise and fall of the load current. This enables highly accurate and efficient grinding, which was difficult with conventional technologies.

[0131] It should be noted that the present invention is not limited to the embodiments described above. Various modifications can be made without departing from the spirit of the present invention. [Explanation of Symbols]

[0132] 1: Surface grinding machine 2: CNC surface grinding machine 3: Control device 11: Shaft head 12: Table 13: Column 14: Cover 15: Control Panel 16: Control panel 17:Operation section 18: Display section 20: Arithmetic device 21:Operation unit 22:Display section 23: Database 24: Information and communication terminals 25: Current detection device 26: Left-hand drive 27: Front and rear handlebars 28: Upper and lower handles 29: Sensor 30: Switch 31: Drive motor 32: Table feeder 33: Forward / backward feed device 34: Up and down feed device 35: Dressing device 36: Grinding fluid supply device A: Current value Ap1: Current value Ap2: Current value As1: Current value As2: Current value T: Time Tp: 1 pass judgment time Ts: Judgment time W: Work ΔAp: Current value difference ΔAs: Current value difference S30: Current value acquisition process S40: Current value characteristic analysis process S50: Grinding condition evaluation process S60: Grinding condition optimization process

Claims

1. A control method for surface grinding, in which a workpiece is ground with a rotating grinding wheel, A current value acquisition step is to acquire the drive current value of the grinding wheel drive motor that rotates the grinding wheel, A current value characteristic analysis step involves analyzing the rise and fall characteristics of the drive current value obtained in the current value acquisition step to generate current value change trend data, A grinding condition evaluation step, which evaluates the grinding conditions based on the current value change trend data generated in the current value characteristic analysis step and the grinding processing data stored in the database, The system comprises a grinding condition optimization step that generates grinding condition optimization data for optimizing the grinding conditions based on the evaluation results of the grinding conditions evaluated in the grinding condition evaluation step, A method for controlling surface grinding, characterized in that grinding is performed based on the grinding condition optimization data generated in the grinding condition optimization step.

2. The control method for surface grinding according to claim 1, characterized in that the grinding conditions and the data for optimizing the grinding conditions include at least one of the cutting depth, feed rate, and feed rate of the grinding wheel.

3. The control method for surface grinding according to claim 2, characterized in that the grinding condition optimization data is generated based on the grinding data so as to increase or decrease at least one of the cutting depth, feed rate, and feed rate when a change characteristic is confirmed in the current value change trend data in which the drive current value rises above a predetermined rate of increase or falls below a predetermined rate of decrease.

4. The grinding condition optimization data generated in the grinding condition optimization process is displayed on the display unit. A control method for surface grinding according to any one of claims 1 to 3, characterized in that the grinding process is performed based on the grinding condition optimization data displayed on the display unit, which is input from the operation unit.

5. The control method for surface grinding according to any one of claims 1 to 3, characterized in that the grinding conditions and the data for optimizing the grinding conditions include dressing conditions for dressing the grinding surface of the grinding wheel.

6. A grinding wheel rotates to grind the workpiece, A grinding wheel drive motor rotates the aforementioned grinding wheel, A current detection device for detecting the drive current value of the aforementioned grinding wheel drive motor, A control device for controlling the grinding process of the workpiece using the grinding wheel, The system comprises a database for storing grinding process data, including information on grinding conditions and grinding results, The control device is The current detection device analyzes the rise and fall characteristics of the drive current value to generate current value change trend data. Based on the generated current value change trend data and the grinding data stored in the database, the current grinding conditions for the grinding process are evaluated. Based on the evaluation results of the grinding conditions, grinding condition optimization data is generated to optimize the grinding conditions. A surface grinding apparatus characterized by controlling the grinding process based on the aforementioned data for optimizing grinding conditions.

7. The system comprises a feed mechanism for moving the workpiece or the grinding wheel so that the workpiece and the grinding wheel move relative to each other, The aforementioned grinding conditions and the data for optimizing the grinding conditions include at least one of the cutting depth, feed rate, and feed rate of the grinding wheel. The surface grinding apparatus according to claim 6, characterized in that the control device controls the feed mechanism based on the grinding condition optimization data to control at least one of the depth of cut, the feed amount, and the feed rate.

8. The surface grinding apparatus according to claim 7, characterized in that the grinding condition optimization data is generated based on the grinding processing data so as to increase or decrease at least one of the cutting depth, feed rate, and feed rate when a change characteristic is confirmed in the current value change trend data in which the drive current value rises above a predetermined rate of increase or falls below a predetermined rate of decrease.

9. A display unit that displays the data for optimizing the grinding conditions, The system comprises an operation unit for inputting the grinding condition optimization data displayed on the display unit, The surface grinding apparatus according to any one of claims 6 to 8, characterized in that the control device controls the grinding process based on the grinding condition optimization data input to the operation unit.

10. The system comprises a dressing device for dressing the grinding surface of the grinding wheel, The aforementioned grinding conditions and the data for optimizing the grinding conditions include the dressing conditions by the dressing device. The surface grinding apparatus according to any one of claims 6 to 8, characterized in that the control device controls the dressing apparatus based on the grinding condition optimization data.

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