JPH0351555B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a dressing device for a grindstone of a grinding machine tool. More specifically, the present invention relates to an automatic grindstone wear measurement method for an automatic dressing device for diamond grindstones used for machining difficult-to-cut materials such as ceramics. <Conventional technology> Dressing refers to the process of renewing and restoring sharpness when a grinding wheel becomes clogged or clogged, resulting in poor cutting quality.Usually, point dressers made from a single diamond, Rotary dressers, crushing rollers, etc. are used depending on conditions such as the type of grinding wheel, grinding conditions, and type of workpiece. When processing difficult-to-cut materials such as ceramics, a diamond grindstone is used as the processing wheel because the workpiece is hard. However, since the workpiece is hard, the diamond grindstone wears quickly and requires frequent dressing. For dressing a diamond whetstone, it would be better to use abrasive grains harder than diamond, but there are none, so the abrasive grains used in dressers are relatively hard among abrasive grains, but softer than diamond. Generally, GC abrasive grains and WA abrasive grains are used as abrasive grains for this dresser. In order to improve the sharpness of dressing, these dresser abrasive grains are bonded together with a relatively soft bonding agent to produce a dressing grindstone. In other words, if a soft binder is used, the abrasive grains involved in grinding will fall off one after another and be renewed, and new abrasive grains will always be involved in cutting, so that sharpness can be maintained. Therefore, these abrasive grains for dressers, that is, grindstones, have a wear amount several times to several tens of times greater than that of diamond grindstones. It is necessary to correct the relative position between the diamond grindstone and the dresser grindstone by the amount of wear using the numerical control device. As a result, since the dressing starting point changes, there are problems in that it is difficult to automate the dressing work and that dressing takes a long time. In particular, it was difficult to automate the dressing work of a diamond grinding wheel by assembling it into the machining center that makes up the FMS. Even with automation, it was difficult because there are many shapes and sizes of diamond grinding wheels. In particular, as a result of dressing, the dimensions of the diamond grindstone for processing also change, which affects the processing dimensions. For this reason, an operator must measure the dimensions of the workpiece and adjust the depth of cut manually, making it difficult to automatically measure the grindstone. <Problems to be Solved by the Invention> In view of the above-mentioned problems, the present invention automates the dressing work of a diamond grinding wheel, automates the measurement of dressing wear, and automates the correction of dressing wear based on this measured value. This is what I did. <Means for Solving the Problems> A tool storage magazine that stores a plurality of tools including a grinding wheel 5; an automatic tool exchange device that exchanges the tools between a rotationally driven machining spindle; Dresser grindstones 9, 22, 53, 56 provided for dressing the tool 5
and the grinding wheel 5 and the dresser grinding wheel 9, 2.
2, 53, 56, the machining center 1 has a sensor 6 for detecting contact with the grinding wheel 5 and the dresser grinding wheel 9, 2.
2, 53, 56 to approach the dressing operation start position 0, and the grinding wheel 5 and the dressing wheel 9, 2.
2, 53, 56 gradually approach in the cutting direction, and a contact time searching step of searching for a time when the grinding wheel 5 and the dresser grinding wheel 9, 22, 53, 56 come into contact; and the grinding. grindstone 5 and the dresser grindstone 9, 2
2, 53, 56, a dressing step in which dressing and cutting are performed a predetermined number of times after the sensor 6 detects contact between the grinding wheels 2, 53, and 56, and the amount of wear of the grinding wheel 5 during dressing and grinding after this dressing. In order to measure, the grinding wheel 5 and the contacts 10a, 10b are brought into contact and measured, and the grinding wheel 5 or The contact 10
An automatic method for measuring grindstone wear, comprising: a wear amount determination step for determining the wear amount from the feed position information of a and 10b; and a correction amount rewriting step for rewriting a correction value from the wear amount. It is. <Function> A grinding wheel driven to rotate from a tool storage magazine storing multiple tools is taken out by an automatic tool changer and attached to the main shaft of a machining center, and the dressing device dresses the grinding wheel. Dressing and measuring method. a dressing operation start position approaching step for bringing the grinding wheel and the dresser wheel closer to a dressing operation start position; and a dressing operation start position approaching step for bringing the grinding wheel and the dresser wheel closer to each other in the cutting direction; a contact time searching step for finding a time when the grinding wheel and the dresser wheel come into contact; and a predetermined number of times after the sensor detects that the grinding wheel and the dresser wheel come into contact. a dressing step for dressing and cutting; and a measuring step for bringing the grinding wheel and a contactor into contact to measure the amount of wear during dressing and grinding of the grinding wheel after this dressing; , a wear amount determination step for determining the wear amount from feed position information of the grinding wheel or the contactor based on a signal sensed by the contactor; and a correction amount for rewriting a correction value from the wear amount. This is an automatic method for measuring grindstone wear that includes a rewriting process. <Example> Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing the overall configuration when the present invention is applied to a horizontal machining center 1. As shown in FIG. A headstock 3 is movable on the bed 2, and a main spindle 4 is rotatably provided on the headstock 3, and a diamond grindstone 5 is chucked at the tip of the main spindle 4. The diamond grindstone 5 can be automatically replaced with another tool by an automatic tool changer (ATC) not shown. The spindle housing that supports the spindle 4 is equipped with a detection ring 6 (described later) that detects contact between the diamond grindstone 5 and the dresser grindstone 9. The dressing device 7 has a structure in which a dressing grindstone 9, a measuring block 10, etc. are mounted on a pallet 8. This dressing device 7
The pallets 8 are pooled in a pallet pool 12 like pallets 8 for processing other workpieces, and are exchanged by a pallet changer 11. When it receives a call from the control device, it is clamped to the table of the machining center 1 and becomes ready for dressing work. Dressing Device (FIG. 2) FIG. 2 shows details of the dressing device. FIG. 2a shows a plan view, and FIG. 2b shows a side view. A dressing device 7 is mounted on the pallet 8. Dressing device 7 mounted on pallet 8
A grindstone shaft 21 is rotatably provided in a housing 20 via a bearing. A grindstone 22 is fixed to one end of the grindstone shaft 21, and a grindstone shaft pulley 23 is fixed to the opposite side. An air motor 26 is mounted parallel to the housing 20. A pulley 25 is fixed to the output shaft of the air motor 26. A belt 24 is stretched between the grindstone shaft pulley 23 and the motor pulley 25. The dresser grindstone 22 used here is basically a general GC grindstone, but in order to make it conductive,
It is divided into segments, and the segments are connected by metal layers 27. This metal layer 27 exists radially from the central hub portion to the outermost diameter of the grindstone. However, the grindstone portion is connected and is not separated from the connection portion between the grindstone portion and the metal layer portion. Further, since the grindstone shaft 21 uses a normal rolling bearing, and the other parts are also made of metal, the metal layer 27 of the dresser grindstone 22, the grindstone shaft 21, the housing 20, the pallet 8, the machining center table, It is electrically connected to the machine itself, including the bed. Solenoid valve 31 and rotary valve 32 from air source 30 outside the machine
The air guided by the shaft 33, table 3
4 through the reference pad 35 on the table top and into the pallet 8 clamped thereon. A block 37 is attached to the pallet 8, and air piping is connected from the block 37 to the air motor 26. As mentioned above, the air entering the pallet 8 passes through the air passage 36 provided in the pallet 8 and the block 37, and is then sent to the air motor 26.
to go into. FIG. 3 shows other necessary items, and in addition to the dressing device 7, a measuring block 10 is fixed to the upper surface of the pallet 8. The measurement block 10 includes a contactor 10a,
10b, which are also made of conductive material. When the diamond grindstone 5 is brought into contact with the contacts 10a and 10b, the NC information of the feed of the spindle 4 at that time or the feed of the table when the pallet 8 is clamped is used to check the wear of the dressing grindstone 9 during the previous dressing. Measure by comparing with the dimensions of. In this embodiment, contact is simply detected, but a non-contact type air micro, electric micro, etc. may also be used. Furthermore, there is also a method of directly measuring the diameter of the dressing grindstone using a measuring device such as a differential transformer or a magnetic scale. A diamond grindstone 5 as a processing tool is attached to the main shaft 4 of the machining center. The diamond grinding wheel 5 is roughly classified into resin bond and metal bond depending on the bonding material, but resin bond generally has no conductivity. However, it is also possible to make the bonding material conductive by adding metal powder to the bonding material. In the case of metal bonds, since they are inherently conductive, there is no problem in using them in the dressing device of this embodiment. Hereinafter, the present invention is based on the premise that a conductive diamond grindstone 5 is used. The main spindle housing of the machining center 1 is equipped with a detection ring 6, and the tool attached to the main spindle 4 detects a conductor on a pallet 8, such as a metal part of a grindstone 9 for a dresser, or a contact 1 of a measuring block.
0a, 10b, etc., a skip signal can be given to a custom macro (a program that can be created by the user) that detects this. The detection ring 6 has two built-in cores in this embodiment, and when the tip of the diamond grinding wheel 5 contacts the dresser grinding wheel 9 to form an RC closed circuit, two cores are generated.
One of the two cores, the excite core, causes a circulating current to flow, the other pickup core captures it, and sends a touch signal to the control section.
(Not shown) Example of application to a vertical machining center (FIG. 4) FIG. 4 shows a case where the present invention is applied to a vertical machining center 40, where a is a side view of the machine and b is a view from the top of the table. In the figure, a dressing device 50 having two grindstone shafts 52, 55, a vertical shaft and a horizontal shaft, is attached to the end of the table. This dressing device 50 includes two dresser grindstones 53 and 56. The grindstone shafts 52 and 55 of both dresser grindstones 53 and 56 are perpendicular to each other. The bottom side of the diamond grindstone 44 is dressed on the side surface of the dresser grindstone 53 having the vertical grindstone shaft 52, that is, on the horizontal surface 54. The diamond grinding wheel 4
Dress the circumferential surface of 4. Since a vertical machining center normally does not have a table indexing function, it is provided with two dresser grindstones 53 and 56. In this embodiment, the dresser grindstones 53 and 56 are each of a type that is appropriately braked and rotates as the processing diamond grindstone 44 rotates. However, the dressing grindstone may be forcibly rotated as in the dressing device 7 shown in FIG. A measuring block 60 similar to the measuring block 10 is arranged adjacent to the dressing device 50. Dressing Operation and Measurement Operation We will consider the case of dressing the end face portion of the diamond grinding wheel 5 and the case of dressing the outer peripheral portion. Dressing of the end face is mainly required for cup-shaped grindstones.
Dressing work is carried out in the positional relationship shown in Fig. 3a-a. Further, the measurement following the dressing operation is carried out at the position B in Fig. 3a. Such position selection is performed using the table index and X, Y, and Z axis movement functions of the horizontal machining center. After selecting the position, the end face of the diamond whetstone 5 is pressed against the end face of the contactor 10b, and the wear of the diamond whetstone 5 is measured based on the contact position. All operations and corrections are performed using custom macros of the NC device. Call the custom macro using the following program. G65P X Z W
H A Here, G65 is the macro call code, P is the end dressing macro program number, X is the diameter of the diamond grinding wheel 5, Z is the dimension of the diamond grinding wheel in the Z direction, W is the radial length to be dressed, H
is the tool offset number, and A is the type of bond, for example, 1: resin bond, 2: metal bond. Flow of End Dressing Operation (FIG. 5) The operation flow of end face dressing will be described in detail below with reference to a flowchart. FIG. 5 shows the operational flow of end face dressing. In FIG. 5, in a step, it is determined whether the diamond grinding wheel 5 is new by referring to a certain variable, and if it is new, there is no need for dressing, so the measurement operation is immediately started. At that time, the variables are automatically rewritten in the step, and will not be handled differently from next time onwards. Note that the variables used here can be set manually in advance, and by setting them on the new grindstone, only the measurement operation can be performed without performing the dressing operation.
If it is determined in this step that the grindstone is not a new one, the process proceeds to the next step. Depending on the type of bond, a step or step is selected, and the number of dressings is optimally set, such as 10 times or 5 times, depending on the type of bond. The type of bond is determined based on the argument A of the macro call. The number of times set here is used in the dressing operation performed in the step. Next, in a step, the pallet 8 is rotated 90 degrees around the B axis (an axis perpendicular to the plane of the pallet) according to the table index, so that the diamonds attached to the dressing device 7 and the machine spindle 4 in FIG. An angular positional relationship A with the grindstone 5 is obtained. Next, in step 0, the approach point shown in FIG.
Move to. In this embodiment, the distance between the side surface of the Dressessa whetstone 9 and the circumferential surface of the diamond whetstone 5 is 10 mm.
Similarly, the circumferential surface and tip surface were set to 0.1 mm. This starting point is preferably located as close to the dressing wheel 9 as possible in order to reduce the empty dressing time. The position of the dresser grinding wheel 9 is known in advance, and the outer diameter and width of the dresser grinding wheel 9 are stored separately in the tool offset memory, so the approach point is automatically calculated from these data. . Next, in a step, the main spindle rotation speed is determined, and in a step, the rotation of the main spindle 4 and the dresser grindstone 9 is turned on. Although the rotation of the dresser grindstone 9 is substantially constant, the rotation speed of the main shaft 4 is determined according to the outer diameter of the diamond grindstone 5 so as to have an optimum circumferential speed. Dressing operation is performed in steps. In FIG. 7, a shows the operation of the diamond grindstone 5 starting from the position shown in FIG. 6 until it comes into contact with the dresser grindstone 9, and b shows the operation thereafter until the dressing is completed. In a, 0 represents the edge of the diamond grinding wheel 5 at the approach point,
The sequential movement of the points is represented by numbers attached in that order. In other words, it moves at a fast rate from the approach point, then moves in the X direction, and returns (same as). Next, a cut is made in the Z-axis direction by a certain amount, for example, 10 μm, and the cut is moved from the position to the X direction, and then returned to (the same position). As this process is repeated, it will come into contact with the dresser grindstone 9 several times. In the figure, it is assumed that contact occurred at point a on the way from to XI. Since both the diamond grindstone 5 and the dresser grindstone 9 are electrically conductive, the detection ring 6 shown in FIG. 1 can detect the contact and obtain it as a skip signal. When a skip signal is input,
After interrupting the operation of the block and returning to the starting point of movement on the X axis (in this example),
become. Here, in step, the rotation of the main spindle 4 and dresser grindstone 9 is stopped, and in step,
Return the table index angle to its original position. As a result, the positional relationship of the diamond grindstone 5 with respect to the pallet 8 in FIG. 3 is as shown in (B). In the step, it almost coincides with the center of the contact 10b of the end face measurement block 10, and is 10 mm from the end face.
It's a remote location. Since the position of the contactor 10b is known in advance and the dimensions of the diamond grinding wheel 5 are given by the arguments X and Z of the custom macro calling program, the position is automatically calculated and
Move to that position. End Face Measuring Operation In the end face measuring operation of the step, as shown in FIG. In Figure b, it approaches the contact 10b in the Z direction from the approach point at a fast feed rate, for example, about 800 mm/min, and makes contact at a point. The contact is detected by the detection ring 6 in FIG. 1 and is given as a skip signal. The skip signal causes the block to jump to the next block, and after the block has dropped, the contact 10b is moved slowly, for example at a rate of about 50 mm/min.
move forward until it touches. The machine position at the point where the skip signal was obtained at this time, contact 10b
The actual Z dimension of the diamond grinding wheel 5 is calculated from the Z coordinate. In step, the tool correction is rewritten using the difference between the planned dimension, the actual dimension, and the actual Z dimension of the diamond grindstone 5 as the correction amount. Furthermore, the diameter of the dresser grindstone 9 is calculated from the machine position at the final stage of dressing and the measured grindstone size Z, and the corresponding tool correction memory is rewritten. Flow of dressing the outer periphery Next, dressing of the outer periphery is mainly required for flat whetstones, whetstones with shafts, etc.
Dressing work is performed in the positional relationship shown in Figure b. Also, following the dressing operation, the measurement operation is
Perform at position B in Figure 3b. Call the custom macro using the following program. G65P X Z W D
A Here, G65 is the macro call code, P is the outer diameter dressing macro program number, X is the diameter of the diamond grinding wheel 5, and Z is the Z of the diamond grinding wheel 5.
In the directional dimension, W is the length of the outer diameter portion to be dressed, D is the tool offset number, and A is the type of bond, for example, 1: resin bond, 2: metal bond. FIG. 9 shows the operational flow of outer peripheral dressing. In the figure, it is determined whether the diamond grinding wheel 5 is new by referring to a variable in the step, and if it is new, there is no need for dressing, so the measurement operation is immediately started.
At that time, the variables are automatically rewritten in the step, and a new grindstone will not be handled from next time onwards. Note that the variables used here can be manually set in advance, so by setting them on a new grindstone, only the measurement operation can be performed without performing the dressing operation. If in the step it is determined that the grindstone is not a new one, then in the next step the number of dressings is set to 10 or 5 depending on the type of bond. The type of bond is determined based on the argument A of the macro call. The number of times set here is used in the dressing operation performed in the step. Next, in step, it is confirmed that the pallet 8 is in its original position around the B-axis (an axis perpendicular to the pallet surface), and if it is not in its original position, it is returned to its original position on the B-axis. Device 7
The angular positional relationship between the diamond grindstone 5 and the diamond grindstone 5 mounted on the machine main shaft 4 can be obtained. Next step,
Move to the approach point shown in FIG. This position has substantially the same positional relationship as the end face dressing. The position of the dressing wheel 9 is predetermined.
Furthermore, since the outer diameter and width of the dresser grindstone 9 are stored separately in the offset memory of the tool, the approach point is automatically calculated from these data. Next, in step, the main spindle rotation speed is determined, and in step, the rotation of the main spindle 4 and the dresser grindstone 9 is turned on. Although the rotational speed of the dresser is approximately constant, the rotational speed of the main shaft 4 is determined according to the diameter of the diamond grindstone 5 so as to have an optimum circumferential speed. Dressing operation is performed in steps. In FIG. 11, a shows the operation of the diamond grindstone 5 starting from the position shown in FIG. 10 until it comes into contact with the dresser grindstone, and b shows the operation thereafter until the dressing is completed. In a, 0 represents the edge of the diamond grinding wheel 5 at the approach point, and the sequential movement of that point is represented by numbers assigned in that order. In other words, it moves at a fast rate from the approach point, then moves in the Z direction, and returns (same as). Next, make a cut in the X-axis direction by a certain amount, for example 10 μm, move from the position to the Z direction, and return to (same as). As this process is repeated, it will come into contact with the dresser grindstone 9 several times. In the figure, it is assumed that contact occurred at point a on the way from to XI. diamond whetstone 5
Since both the dresser grindstone 9 and the dresser grindstone 9 are electrically conductive, the detection ring 6 shown in FIG. When a skip signal is input, the operation of that block is interrupted and the block returns to the Z-axis movement start point (in this example), as shown in FIG. 11b.
Here, after completing a certain amount of cut in the X direction for the number of times n set in the step and step, spark out is performed several times at the same cut position, and then the X-axis mechanical coordinates of that position are memorized. and then returns to the approach point (0 in Figure 11a). Note that during the series of operations in the step, the first
The operation up to contact with the grinding wheel explained in Figure 1a is shown in Figure 11c.
It is also possible to carry out the method shown in . That is, it moves from approach point 0 to point 1 with fast feed, and then moves in the X-axis direction with slow feed.
If the grindstone comes into contact with the grindstone on the way, a skip signal is input, so the movement in the X-axis direction is interrupted, and the state shown in FIG. 11b is from the position shown in FIG. The subsequent movements are as already described. Measurement of outer diameter Next, in step, the rotation of the spindle and dresser is stopped. In this step, the robot moves to the outer diameter measurement approach point (see FIG. 12). In this position, the end face of the diamond grinding wheel 5 is the measuring block 1.
It almost coincides with the center of the contact 10a of 0, and the outer diameter is Y
Located 10mm apart in the axial direction. Since the position of the contactor 10a is known in advance and the dimensions of the diamond grindstone 5 are given by the arguments X and Z of the macro calling program, the position is automatically calculated and moved to that position. In the step outer diameter measurement operation, the contact 10a
, contact 1 in the Y direction from the approach point
Approach 0a with a fast feed, for example about 800 mm/min, and make contact at a point. The first thing that came into contact with me was
It is detected by the detection ring 6 in the figure and given as a skip signal. Jump to the next block with a skip signal. When the contact 10a lowers, slowly feed it, for example about 50mm/min.
move forward until it touches. At this time, the actual diameter Z dimension of the diamond grindstone 5 is calculated from the machine position at the point where the skip signal was obtained and the Y coordinate of the contact 10a. In step, the tool correction is rewritten using the difference between the planned dimensions of the diamond grindstone 5 and the measured actual dimensions as the correction amount. Furthermore, the diameter of the dresser grindstone 9 is calculated from the machine position at the final stage of dressing and the measured dimensions of the diamond grindstone 5, and the corresponding tool correction memory is rewritten. The above description is for a horizontal machining center, but a similar dressing operation can be performed for a vertical machining center by slightly changing the dressing shape and processing software. In the case of a vertical machining center, the table index function is
It is normal that they are not prepared. In the embodiment shown in Fig. 3, there are two types: one for end face dressing and one for outer diameter dressing.
It has two whetstones, so you can use one depending on the dressing area. That is, when dressing the end face of a horizontal machining center, table indexing is performed in the steps shown in FIG. 5, but in the case of a vertical machining center, dressing can be performed at the position of the dresser grindstone 9 shown in FIG. 3. Control Device for Dressing Apparatus FIG. 13 is a block diagram showing an example of the control device of the present invention. Processing program for processing the workpiece, diameter X of the diamond grindstone (processing grindstone), Z direction dimension Z,
Equipped with data such as dressing length W, offset number H, bond type A, dresser grindstone data, dressing program, measurement program, and memory to store wear amount of processing grindstone and dresser grindstone. There is. The dressing start position is detected by the detection ring 6, NC position information is taken out, the dressing start position is detected from this information, and dressing is started. Similarly, in the measurement operation, the contacts 10a and 10b detect the contact of the diamond grinding wheel, extract the position from the NC information, calculate the amount of wear, and store the correction value. This value is used to correct the grindstone position during grinding. <Other Embodiments> The present invention is not limited to the above embodiments, and various design changes can be made within the scope of the basic technical idea of the present invention. An example of the change is shown below. In the embodiments described so far, the contact detection between the diamond grinding wheel 5 and the dresser grinding wheel 9 or the measuring block 10 is performed using the inductive detection type detection ring 6, but the method of contact detection is There is no need to limit it to this only. For example, it is also possible to insulate a part of the path from the spindle to the housing, column, bed, and table, apply a potential difference across it, and detect contact based on a change in the potential difference. Another method is to attach a strain gauge or IC pressure sensor to a measuring block or spindle head to detect the force at the time of contact. In the embodiment described above, the measuring block 10 is provided on the pallet 8, but there is also a method in which the measuring block 10 is fixed to the headstock 3 or the bed 2 and the diamond grindstone 5 is measured. There is a method of indirectly measuring the diamond whetstone by measuring the dresser whetstone 9 instead of measuring the diamond whetstone 5. This measurement can also be done by checking the spindle 4 with a touch sensor and measuring the diameter of the dresser grindstone 9. <Effects of the Invention> As described above, the present invention has the following effects. a) It has become possible to accurately and automatically measure the wear of diamond grinding wheels in machining centers. b. Dressing of grindstones with various shapes, abrasive grains, and binders can be automated. c Can be incorporated into systems such as FMS. d) The time required for dressing is shortened. e The grindstone dimensions after dressing are automatically corrected, making it easy to maintain machining accuracy.

[Brief explanation of drawings]

The embodiment of FIG. 1 is a diagram showing the entire embodiment of the present invention, FIG. 2a is a plan view of the dressing device,
Figure b is a front view of the dressing device, Figure 3 a is a plan view showing the positions of dressing and measuring operations, and Figure 3
Fig. 4b shows a front view of the same, Fig. 4a shows another embodiment in which the dressing device of the present invention is applied to a vertical machining center, and Fig. 4b shows the dressing device of Fig. 4a. Figure 5 is a flowchart of the end face dressing operation, Figure 6 is a diagram showing the starting point of the end face dressing operation, Figure 7a is a diagram of the movement path of the diamond grinding wheel until the dressing operation starts, and Figure 7b is the dressing operation. Figure 7c is a route diagram showing other operations, Figure 8a is a diagram showing the starting point of the end face measurement operation, Figure 8b is a route diagram showing the end face measurement operation, and Figure 9 is an operation flow diagram of outer circumference dressing. Fig. 10 is a diagram showing the starting point of the outer circumference dressing operation, Fig. 11a is a route diagram until the outer circumference dressing operation is started, Fig. 11b is an operation route diagram of outer circumference dressing, and Fig. 11c is an outer circumferential dressing operation route diagram. Other path diagrams of the dressing operation, FIG. 12a is a diagram showing the starting point of outer circumference measurement, FIG. 12b is an operation route diagram of outer circumference measurement, and FIG. 13 is a diagram showing the automatic measurement method of grindstone wear of the present invention. FIG. 3 is a control block diagram for DESCRIPTION OF SYMBOLS 1... Machining center, 2... Bed, 3... Headstock, 4... Spindle, 5... Diamond grindstone, 6... Detection ring, 7... Dressing device, 8... Pallet,
9... Grindstone for dressing, 10... Measuring block, 11... Pallet changer, 12... Pallet pool.

Claims (1)

[Scope of Claims] 1. A tool storage magazine that stores a plurality of tools including a grinding wheel 5; an automatic tool exchange device that exchanges the tools between a rotationally driven machining spindle; and the grinding tool 5. Dresser grindstones 9, 22, 53, 56 provided for dressing
and the grinding wheel 5 and the dresser grinding wheel 9, 2.
2, 53, 56, the machining center 1 has a sensor 6 for detecting contact with the grinding wheel 5 and the dresser grinding wheel 9, 2.
2, 53, 56 to approach the dressing operation start position 0, and the grinding wheel 5 and the dressing wheel 9, 2.
2, 53, 56 gradually approach in the cutting direction, and a contact time searching step of searching for a time when the grinding wheel 5 and the dresser grinding wheel 9, 22, 53, 56 come into contact; and the grinding. grindstone 5 for dressers and the grindstone 9 for dressers,
22, 53, 56, a dressing step in which dressing and cutting are performed a predetermined number of times after the sensor 6 detects contact with the grinding wheel 5, and the amount of wear of the grinding wheel 5 during dressing and grinding after this dressing. In order to measure, the grinding wheel 5 and the contacts 10a, 10b are brought into contact and measured, and the grinding wheel 5 or The contact 10
A method for automatically measuring grindstone wear, comprising: a wear amount determining step for determining the wear amount from the feed position information of a and 10b; and a correction amount rewriting step for rewriting a correction value from the wear amount. .