JP2007319907A - Surface treatment device for workpiece - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface treatment device where, while rotating a rotary tool, the tip part thereof is thrust into the surface part of a workpiece, thus surface treatment is performed thereto, by which, as the thrusting amount is held not so as to be more excessive than a standard thrusting amount, the period for detecting the actual tip position of the rotary tool is changed, and the total time required for the detection of the position is reduced, so as to drastically increase the productivity of the workpiece. <P>SOLUTION: A position detection means 6 detects the actual tip position to the tip standard position in the rotary tool 10, and based on the actual tip position, a thrusting amount correction means 7 corrects a tool thrusting amount for thrusting the rotary tool 10 into the surface part Wa of the workpiece W, and a command means 8 outputs a command for operating the position detection means 6 and the thrusting amount correction means 7. At this time, regarding the detection period for detecting the actual tip positions of a plurality of the rotary tools 10 by the position detection means 6, the detection period in the case the frequency of the rotation of the plurality of rotary tools 10 is equal to or less than a prescribed value is made shorter than the detection period in the case it is higher than the prescribed value. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  In the present invention, while rotating a rotary tool attached to a spindle of a machine tool, its tip is pushed into a surface portion of a workpiece, and the surface portion of the workpiece is softened by frictional heat with the rotary tool to be plastically flowed and modified. The present invention relates to a surface treatment apparatus for a workpiece that performs surface treatment.

  Conventionally, a technique for modifying the surface portion of an aluminum alloy workpiece made of a cast product using the workpiece surface treatment apparatus is well known, and the surface portion of the workpiece subjected to this surface treatment has a metallographic structure. , The uniform dispersion of eutectic silicon particles, the reduction of casting defects, and the like, and the durability (thermal fatigue strength, impact resistance) is enhanced. For example, Patent Documents 1 and 2 disclose a technique in which the surface treatment is performed on a valve portion between adjacent supply / exhaust ports in an engine cylinder head.

  In this workpiece surface treatment device, a dimensional change (thermal expansion) caused by a temperature change of the rotary tool and the spindle occurs mainly due to frictional heat between the rotary tool and the workpiece, and due to a change in the temperature of the outside air and the working fluid of the device. Due to this dimensional change, the tool push-in amount for pushing the rotary tool into the surface portion of the workpiece varies. And even if the tool push-in amount becomes too small or too large than the reference push-in amount, the surface part of the workpiece cannot be properly modified.For example, if the tool push-in amount becomes smaller than the reference push-in amount, If there is a concern about the occurrence of unfilled defects and the tool push-in amount is larger than the reference push-in amount, the trace of the rotary tool may remain on the surface of the workpiece.

  Here, as disclosed in Patent Documents 1 and 2, when a plurality of rotary tools are rotated and used, compared to a case where a single rotary tool is used continuously, the use of each rotary tool is used. Since the time (operation time) can be shortened and the cooling period is lengthened, thermal expansion of the rotary tool can be suppressed. However, as the number of rotations of multiple rotary tools increases, frictional heat accumulates in the rotary tool. In addition, since the thermal expansion of the spindle cannot be suppressed, the tendency of the tool pressing amount to be larger than the reference pressing amount cannot be suppressed.

Therefore, in Patent Document 1, the actual tip position with respect to a predetermined tip reference position of the rotary tool attached to the spindle is detected by a touch sensor or the like, and the tool push-in amount is determined based on the actual tip position. A technique for correcting the amount of indentation) is described.
JP 2003-48064 A Japanese Patent Laid-Open No. 2003-120415

  When the actual tip position with respect to a predetermined tip reference position of the rotary tool attached to the spindle is detected by a touch sensor or the like as in the technique described in Patent Document 1, the tool push amount is determined as the reference push amount based on the actual tip position. Although the time required for detecting the actual tip position of the rotary tool (for example, about 20 seconds) is relatively long, the position detection of the rotary tool is always performed each time the number of rotations increases. If this is done, the total time required for this position detection increases, so the productivity of the workpiece is significantly reduced.

  The object of the present invention is to correct the tool pressing amount for pressing the rotary tool into the surface portion of the workpiece during the surface treatment to the reference pressing amount, to reliably modify the surface portion of the workpiece, and to Keeping the tool push-in amount from exceeding the reference push-in amount, taking into account the changing tendency of the actual tip position with respect to the predetermined tip reference position of the rotary tool when using the rotary tool in rotation. On the other hand, by changing the cycle for detecting the actual tip position of the rotary tool and properly decimating the position of the rotary tool, the total time required to detect the position is greatly reduced, and the productivity of the workpiece is improved. The object is to provide a workpiece surface treatment apparatus which can be remarkably improved.

  The surface treatment apparatus for a workpiece according to claim 1 pushes the tip portion into the surface portion of the workpiece while rotating the rotary tool detachably attached to the spindle of the machine tool, and softens the surface portion of the workpiece by frictional heat. A surface treatment is performed by plastic flow, and a plurality of rotary tools used for the surface treatment are rotated and used, and the used rotary tool is replaced every time the series of surface treatments are performed one or more times. In the workpiece surface treatment apparatus configured as described above, position detecting means capable of detecting an actual tip position with respect to a predetermined tip reference position of the rotary tool attached to the main shaft for use, and an actual tip detected by the position detecting means A pressing amount correcting means for correcting the tool pressing amount for pressing the rotary tool into the surface portion of the workpiece during the surface treatment to be a reference pressing amount based on the position; Command means for outputting a command for operating the position detection means and the push-in amount correction means, wherein the rotation of the plurality of rotary tools is detected with respect to a detection cycle in which the position detection means detects the actual tip positions of the plurality of rotary tools. Command means for shortening the detection cycle when the number of times is equal to or less than a predetermined value to be shorter than the detection cycle when the number of times is larger than the predetermined value.

  In this workpiece surface treatment apparatus, a rotary tool is detachably attached to a spindle of a machine tool, the rotary tool rotates, a tip portion is pushed into the surface portion of the workpiece, and the surface portion of the workpiece is in contact with the rotary tool. It is softened by frictional heat and plastically flows to be modified. A plurality of rotating tools used for surface treatment are rotated and used, and the rotating tool used for use is replaced every time a series of surface treatments are performed one or more times. Compared with the case of using, since the use time (operation time) of each rotary tool is shortened and the cooling period is lengthened, the thermal expansion of the rotary tool can be suppressed. However, as the number of rotations of the rotating tool increases, friction heat accumulates in the rotating tool, and the thermal expansion of the spindle cannot be suppressed, so the tool pushing amount tends to be larger than the reference pushing amount. Can not be suppressed.

  Therefore, when the actual tip position with respect to a predetermined tip reference position of the rotary tool attached to the main shaft for use is detected by the position detection unit, the push amount correction unit detects the actual tip position based on the actual tip position detected by the position detection unit. Therefore, when the surface treatment is performed, the tool push-in amount that pushes the rotary tool into the surface of the workpiece is corrected so that it becomes the reference push amount. In the workpiece surface after the surface treatment, the metal structure is made finer and the durability (thermal fatigue strength, impact resistance) is enhanced. However, the time required for detecting the actual tip position of the rotary tool is relatively long, and if the position detection of the rotary tool is always performed every time the number of rotations increases by one, the productivity of the workpiece is significantly reduced.

  Here, the dimensional change accompanying the temperature change of the rotary tool and the spindle is mainly caused by frictional heat generated between the rotary tool and the workpiece as the number of rotations increases from the start of the machine tool. The dimensional change amount tends to gradually decrease. Therefore, the detection cycle for detecting the actual tip positions of the plurality of rotary tools by the command means is made shorter than the detection cycle when the number of rotations is less than or equal to a predetermined value. In this way, by outputting a command for operating the position detecting means and the push-in amount correcting means, the tool push-in amount becomes the reference push-in amount in consideration of the change tendency of the actual tip position with respect to the predetermined tip reference position of the rotary tool. The period for detecting the actual tip position of the rotary tool is changed in order to correct the tool push-in amount while maintaining it so as not to become excessive.

  In the invention of claim 1, the command means sets the detection cycle when the number of rotations since the start of the machine tool is greater than a first predetermined value to a fixed cycle (claim 2). When the rotation number from the start of the machine tool is equal to or smaller than a second predetermined value that is smaller than the first predetermined value, the position detection unit and the push amount correction are performed each time the rotation number increases by one. (Claim 3), the command means increases the second predetermined value as the number of rotating tools to be subjected to the surface treatment decreases (Claim 4). It is possible to adopt a configuration in which, as the number of rotating tools used for the surface treatment is smaller, the detection cycle is shortened as a whole (Claim 5), and the workpiece is a cylinder head of an engine (Claim 6). .

  According to the workpiece surface treatment apparatus of the first aspect, since the position detecting means and the push-in amount correcting means are provided, the actual tip position with respect to the tip reference position of the rotary tool attached to the spindle for use is detected. Based on the tip position, the tool push-in amount that pushes the rotary tool into the surface part of the workpiece during surface treatment can be corrected so that it becomes the reference push amount. Since the command means is provided, the detection cycle for detecting the actual tip positions of a plurality of rotary tools is set to a detection cycle when the number of rotations is less than a predetermined value. By outputting a command to operate the position detection means and push-in amount correction means so as to be shorter than the detection cycle when it is larger than the value, a plurality of rotary tools are rotated and used. The actual tip position of the rotary tool is detected while maintaining the tool push-in amount not exceeding the reference push-in amount, taking into account the change tendency of the real tip position relative to the tip reference position of the rotary tool. The position of the rotating tool is changed and the position detection of the rotary tool is appropriately thinned out, so that the total time required for the position detection can be greatly reduced, and the productivity of the workpiece can be increased.

  According to the workpiece surface treatment apparatus of the second aspect, the command means sets the detection cycle when the number of rotations since the start of the machine tool is larger than the first predetermined value to a constant cycle. When it is larger than the predetermined value, the dimensional change due to the thermal expansion of the rotary tool is small and the temperature change of the main spindle is also small. By setting a value, the tool push-in amount can be maintained so as not to be larger than the reference push-in amount, and the position detection of the rotary tool can be performed at a constant cycle.

  According to the workpiece surface treatment apparatus of the third aspect, the command means has the number of rotations once when the number of rotations since the start of the machine tool is equal to or less than a second predetermined value smaller than the first predetermined value. Since the position detection means and the push-in amount correction means are operated each time the tool is increased, the tool push-in is performed especially during the period when the rate of increase in dimensional change accompanying the temperature change of the rotary tool is large (the rotary tool and spindle are cold). The tool push-in amount can be reliably corrected to be the reference push-in amount so that the amount does not exceed the reference push-in amount.

  According to the workpiece surface treatment apparatus of the fourth aspect, the command means increases the second predetermined value as the number of rotating tools to be subjected to the surface treatment decreases, so that the number of rotating tools to be subjected to the surface treatment decreases. Since the number of rotations until the change of the actual tip position with respect to the tip reference position of the rotary tool becomes larger, the tool push amount does not become larger than the reference push amount by increasing the second predetermined value. The tool push-in amount can be reliably corrected so as to be the reference push-in amount.

  According to the workpiece surface treatment apparatus of claim 5, the instruction means shortens the detection cycle as a whole as the number of rotating tools to be subjected to the surface treatment decreases, so that the command means corresponds to the number of rotating tools to be subjected to the surface treatment. By properly setting the detection cycle, the tool push amount can be reliably corrected to be the reference push amount so that the tool push amount does not become larger than the reference push amount.

  According to the workpiece surface treatment apparatus of the sixth aspect, since the workpiece is a cylinder head of the engine, for example, surface treatment is performed on the valve portion between the air supply / exhaust ports of the cylinder head to thereby improve durability of the valve portion. And the productivity of high quality cylinder heads can be increased.

  In the workpiece surface treatment apparatus of the present invention, the position detection means detects the actual tip position relative to a predetermined tip reference position of the rotary tool attached to the spindle for use, and the push amount correction means detects the actual tip position. Based on the actual tip position, the tool push amount for pushing the rotary tool into the surface portion of the workpiece during the surface treatment is corrected so as to become the reference push amount, and the command means causes the position detection means and the push amount correction means to In this case, with respect to the detection cycle in which the position detection means detects the actual tip positions of the plurality of rotary tools, the detection cycle when the number of rotations of the plurality of rotary tools is less than or equal to a predetermined value is less than the predetermined value. The detection period is shorter than the detection period when it is larger.

  FIG. 1 is a configuration diagram of a workpiece surface treatment apparatus 1 according to the present invention, FIG. 2 is a side view of a tip portion of a rotary tool 10, and FIG. 3 is a cross-sectional view of a main part including the rotary tool 10 and the workpiece W of FIG. It is. As shown in FIG. 1, the surface treatment apparatus 1 includes a main shaft 2 to which a rotary tool 10 is detachably attached, tool rotating means 3 that rotates the rotary tool 10 (main shaft 2), and the rotary tool 10 (main shaft 2). A tool relative moving means 4 for moving the workpiece W relative to the workpiece W is provided. The rotary tool 10 attached to the spindle 2 is rotated together with the spindle 2 and the tip thereof is pushed into the surface portion Wa of the workpiece W. A surface treatment (friction stirring treatment) is performed in which the surface portion Wa is softened by frictional heat with the rotary tool 10 and is plastically flowed for modification.

  As shown in FIGS. 1 to 3, the rotary tool 10 is made of a material (for example, a steel material such as carbon steel) having a hardness higher than that of the material of the workpiece W (for example, an aluminum alloy). The probe portion 12 protrudes from the center of the distal end of the base portion 11, a screw thread is formed on the probe portion 12, and a flat shoulder portion 13 is formed on the distal end surface of the rotation base portion 11. In addition, in this rotary tool 10, various rotary tools, such as those in which the probe portion 12 is not formed with a thread, those in which the probe portion is omitted, and those in which the shoulder portion is tapered toward the base end side, can be adopted. is there.

  In this surface treatment, first, while the rotary tool 10 rotates, the probe portion 12 of the rotary tool 10 is pushed into the surface portion Wa of the workpiece W to be positioned, and subsequently, the tip portion of the rotation base portion 11 is moved from the shoulder portion 13 to the workpiece. It is pushed into the surface portion Wa of W, and the surface portion Wa of the workpiece W is softened by frictional heat with the rotary tool 10 to cause plastic flow and is stirred and modified. In FIG. 1, the rotary tool 10 is relatively moved with respect to the workpiece W in a state where the tip of the rotary tool 10 is pushed into the surface portion Wa of the workpiece W, and the surface continuously reaches the surface portion Wa of the workpiece W. The form which a process is performed is shown. However, the surface treatment Wa of the workpiece W can be spot-treated.

  The workpiece W is a cast product made of an aluminum alloy, and the surface portion Wa of the workpiece W that has been subjected to surface treatment is designed to refine the metal structure, uniformly disperse eutectic silicon particles, reduce casting defects, and the like. And durability (thermal fatigue strength, impact resistance) is enhanced. The workpiece W is, for example, the cylinder head W of the engine shown in FIG. 8, and the surface treatment is performed on the valve portion Wd between the adjacent supply / exhaust ports Wb and Wc in the cylinder head W. As the workpiece W, various workpieces such as those made of light metal other than aluminum alloy, those made of metal other than light metal, those made of forged products, workpieces other than the cylinder head, and the like can be applied.

  As shown in FIG. 1, the surface treatment apparatus 1 includes a tool changer 5 for exchanging the rotary tool 10 attached to the spindle 2, and rotates a plurality (for example, four) of rotary tools 10 used for the surface treatment. The rotating tool 10 used for use is exchanged every time a series of surface treatments are performed a plurality of times. Here, when the workpiece W is the cylinder head W of FIG. 8, the surface treatment is applied to all of the four inter-valve portions Wd corresponding to the four cylinders. The series of surface treatments refers to the surface of each inter-valve portion Wd. This refers to the process from the start to the completion. Therefore, every time a series of surface treatments are performed four times, that is, for each cylinder head W, the used rotary tool 10 is replaced.

  The surface treatment apparatus 1 includes a position detection unit 6 capable of detecting an actual tip position with respect to a predetermined tip reference position of a rotary tool 10 attached to the spindle 2 and used for use, and an actual tip position detected by the position detection unit 6. Based on the pressing amount correction means 7 for correcting the tool pressing amount F for pressing the rotary tool 10 into the surface portion Wa of the workpiece W during the surface treatment to the reference pressing amount FB, the position detection means 6 and the pressing amount correction. The command means 8 outputs a command for operating the means 7, and the number of rotations Rn of the plurality of rotary tools 10 is a predetermined value for the detection period in which the position detection means 6 detects the actual tip positions of the plurality of rotary tools 10. Command means 8 is provided that makes the detection cycle in the following cases shorter than the detection cycle when it is larger than the predetermined value and sets the detection cycle when it is larger than the predetermined value to a constant cycle.

  Here, the surface treatment apparatus 1 including the main shaft 2 and the plurality of means 3 to 8 will be specifically described. As shown in FIGS. 4 and 5, the surface treatment apparatus 1 is mainly configured by a machine tool 15 such as a machining center. In the machine tool 15, the main shaft 2 is supported in a vertical direction so as to be rotatable and movable up and down. 2, the table 16 is supported so as to be movable in two horizontal orthogonal directions (X direction and Y direction), and the workpiece W is positioned and supported by the table 16.

  The machine tool 15 includes a control unit 20 including an NC controller 21, a tool rotation motor 22, a tool lifting motor 23, table X and Y motors 24 and 25, a tool changer 26, a tool magazine 27, and a touch sensor 27. The tool rotation motor 22 corresponds to the tool rotation means 3, the tool lifting / lowering motor 23 and the table X and Y motors 24, 25 correspond to the tool relative movement means 4, the tool changer 26 corresponds to the tool change means 5, and the control unit. 20, the tool lifting motor 23, the table X and Y motors 24 and 25, and the touch sensor 27 correspond to the position detection means 6, and the control unit 20 corresponds to the push amount correction means 7 and the command means 8.

  The control unit 20 drives the tool rotation motor 22 on the basis of the NC program set in advance according to the workpiece W, and numerically controls the tool lifting motor 23 and the table X, Y motors 24 and 25, When the workpiece W is subjected to surface treatment, and the workpiece W is the cylinder head W of FIG. 8, the rotary tool 10 is applied to the workpiece W along the path indicated by the arrow at each of the four valve portions Wd. The surface treatment is performed by relative movement.

  The tool magazine 27 accommodates at least a plurality of (for example, four) rotary tools 10 to be used for the surface treatment, and the tool changer 26 is driven and controlled by the control unit 20 so that the used rotary tool 10 is used as a tool magazine. When the workpiece W is the cylinder head W of FIG. 8, the rotary tool 10 is replaced every time the surface treatment of one cylinder head W is completed. The tool magazine 27 also stores a burr removing tool. If necessary, after the surface treatment of the workpiece W, the burr removing tool is mounted on the spindle 2 to remove unnecessary burrs generated on the workpiece W. The

  As shown in FIGS. 6 and 7, the touch sensor 28 is arranged and fixed upward on the work W on the upper surface of the table 16 and a portion that does not interfere with the surface treatment, and is electrically connected to the control unit 20. . When detecting the actual tip position with respect to a predetermined tip reference position of the rotary tool 10 attached to the spindle 2, the table X and Y motors 24 and 25 are controlled by the control unit 20, and the touch sensor 28 is moved to the rotary tool 10. While being positioned on the lower side, the tool lifting / lowering motor 23 is controlled to lower the rotary tool 10 to contact the touch part 28a of the touch sensor 28, and the touch signal is transmitted from the touch sensor 28 to the control unit 20.

  In the control unit 20, the tip reference position of the rotary tool 10 is stored, and based on the drive amount of the tool lifting motor 23 when a touch signal is received from the touch sensor 28 with respect to the tip reference position, the rotary tool 10 is stored. Ten actual tip positions are calculated and detected. Based on this actual tip position, the tool pressing amount F for pressing the rotary tool 10 into the surface portion Wa of the workpiece W during the surface treatment is corrected so as to become the reference pressing amount FB.

  Here, a dimensional change (mainly, thermal expansion) due to a temperature change of the rotary tool 10 and the spindle 2 is mainly caused by frictional heat between the rotary tool 10 and the workpiece W, or by a temperature change of the outside air or the apparatus hydraulic oil. Due to this dimensional change, detection of the actual tip position and correction of the tool push amount are necessary so that the tool push amount F does not become excessive, but here, as shown in FIG. When the workpiece W is the cylinder head W of FIG. 8 with respect to the amount of change in the actual tip position with respect to the tip reference position of the rotary tool 10 with respect to the elapsed time since the start of the machine tool 15, A plurality of data of Examples and Comparative Examples 1 and 2 were collected.

  In the second comparative example, one rotary tool 10 is continuously used for 88 workpieces W, and the tool push amount is detected by using the touch sensor 28 every time the rotary tool 10 is replaced, so that the surface treatment is performed. The amount of change in the tool length of the rotary tool 10 detected for each workpiece W including when the machine tool 15 is started is shown. In Comparative Example 1, four rotary tools 10 are rotated to 88 workpieces W. The rotary tool 10 used is replaced every time the surface treatment of one workpiece W is completed, and the tool push-in amount is detected by using the touch sensor 28 every time the rotary tool 10 is replaced. The amount of change in the tool length of the rotary tool 10 detected for each workpiece W including the time when the machine tool 15 is started is shown for one rotary tool 10.

  In the embodiment, 88 workpieces W are used by rotating four rotary tools 10, and the used rotary tool 10 is replaced every time the surface treatment of one workpiece W is completed. Surface treatment is performed so that the tool push-in amount is detected using the touch sensor 28 only when the number of times is the number of rotations, and the rotation detected for each of the workpieces W including one at the start of the machine tool 15 for one rotary tool 10. The change amount of the tool length of the tool 10 is shown. Note that the period of about 170 to 220 minutes is a period in which the machine tool 15 is stopped due to, for example, a lunch break.

  In the comparative example 2, the amount of change in the tool length becomes extremely large until about 12 minutes from the start of the machine tool 15 until the surface treatment of about 12 workpieces W is performed. There are places that are stable but unstable. In Comparative Example 1, the amount of change in the tool length gradually increases until the surface treatment of about 12 workpieces W is performed for about 50 minutes from the start of the machine tool 15, and then gradually increases but stabilizes. The surface is stabilized after the surface treatment of about 44 workpieces W is performed for about 100 minutes after the machine tool 15 is started.

  For example, the time required for the surface treatment of one workpiece W is about 6 minutes, but the time for one rotary tool 10 required for measuring the tool length requires about 21 seconds. If the tool length is measured for each unit, 21 × 400 = 8400 seconds = 140 minutes are required, and the productivity of the workpiece W becomes extremely low. Therefore, in consideration of such test results, in the surface treatment apparatus 1 of the present invention, the productivity of the workpiece W is improved while maintaining the tool pushing amount F so as not to be larger than the reference pushing amount FB. It is comprised so that the period which detects the real tip position of the rotary tool 10 may be changed so that it may obtain.

  Next, with respect to the processing including the surface processing executed by the control unit 20 of the surface processing apparatus 1, the flowchart of FIG. 9 (Si (i = 1, 2, 3... In the figure indicates each step)). This will be explained based on. A program for executing this processing is stored in a storage unit (such as a ROM of a computer) of the control unit 20. In addition, the four rotary tools 10 used for surface treatment are rotated and used, and the tool numbers 1 to 4 are respectively associated with these rotary tools 10, and a series of surface treatments are performed on the workpiece W including the cylinder head W. Every time the work W is exchanged four times, the used rotary tool 10 is exchanged.

  As shown in FIG. 9, this process is started when the machine tool 15 is operated (at the time of activation). First, the number of rotations Rn of the plurality of rotary tools 10 is set to 1, and the tool number Tn is set to 1. (S1). Next, it is determined whether or not Rn ≦ 3 or Rn = 7 or Rn = 11 (S2). If S2; Yes, the actual tip position detection process (S3) and the tool push-in amount correction process (S4) are performed. As described above, the actual tip position with respect to the predetermined tip reference position of the rotary tool 10 is detected as described above, and the rotary tool 10 is pushed into the surface portion Wa of the workpiece W during surface treatment based on the actual tip position. The tool push amount F is corrected so as to become the reference push amount FB.

  After S4, a surface treatment (S5) is performed, and as described above, the tip of the rotary tool 10 is pushed into the surface portion Wa of the workpiece W while the rotary tool 10 is rotated. It is softened by the frictional heat and plastically flows and reformed, and in this case, the surface treatment is applied to all the four valve-interval portions Wd of the cylinder head W (S5). Thereafter, it is determined whether or not Tn = 4 (S6). If S6; No, Tn is incremented to Tn + 1 (S7), replaced with the rotary tool 10 corresponding to Tn (S8), and the process returns to S3.

  On the other hand, in the case of S2; No, similarly to S5 to S8, the surface treatment (S9) is executed to determine whether Tn = 4 (S10). In the case of S10; No, Tn is incremented to Tn + 1 (S11). ), The tool is replaced with the rotary tool 10 corresponding to the Tn (S12), and the process returns to S9. Thus, the surface treatment is performed on the four workpieces W by the four rotary tools 10, and in this case, when Rn ≦ 3 or Rn = 7 or Rn = 11, the actual tip position with respect to each rotary tool 10. The detection process and the tool push-in amount correction process are executed. When Rn ≦ 3 or Rn = 7 or Rn = 11, the actual tip position detection process and the tool push-in amount correction process are omitted.

  When surface treatment is performed on the four workpieces W by the four rotary tools 10, Tn = 4, so S6; Yes or S10; Yes, and then whether or not the total number of rotations Rna <set times Is determined (S13). This Rna is used to measure the life of the rotary tool 10 and is stored and held even when the machine tool 15 is not operated. In S13; No, it is determined whether or not Rn = 21 (S14). In S14; No, Rn is incremented to Rn + 1 (S15), and in S14; Yes, Rn is set to 11. Then, Ran is incremented to Rna + 1 (S17), and the process returns to S2.

  Here, in the case of S13; Yes, the tool change notification (S18) is executed. In this tool change notification, the change of the rotary tool 10 is notified by voice, a lamp or the like, and based on this notification, it is rotated and used. The four rotary tools 10 are switched to the new four rotary tools 10, and tool numbers 1 to 4 are associated with the four rotary tools 10, respectively. Thus, when the tool switching is completed (S19; Yes), Rna is set to 1 (S20) and the process returns.

  That is, for each rotating tool 10, when the rotation number Rn is 1 to 3, the actual tip position detection process (S3) and the tool push amount correction process (S4) each time the rotation number Rn increases by one, When the rotation number Rn is 4 to 11, the actual tip position detection process (S3) and the tool push amount correction process (S4) are performed each time the rotation number Rn increases four times from the third time. When the rotation number Rn is 12 or more in total, the actual tip position detection process (S3) and the tool push-in amount correction process (S4) are executed every time the rotation number Rn increases by 10 times.

  Here, as shown in FIG. 11, with respect to the amount of change in the tool push amount F of the rotary tool 10 with respect to the elapsed time from the start of the machine tool 15, when the workpiece W is the cylinder head W of FIG. A plurality of data of Examples and Comparative Examples 1 and 2 were collected. In Comparative Example 2, surface treatment was performed on 88 workpieces W using one rotary tool 10 continuously, and the tool push-in amount F was corrected for each workpiece W including when the machine tool 15 was started. The amount of change in the tool push-in amount F is shown. In Comparative Example 1, the tool push-in amount F in the case where the tool push-in amount F is not corrected using the four rotary tools 10 rotated on 88 workpieces W is used. The amount of change is shown.

  In Comparative Example 2, since the tool push amount F is corrected for each workpiece W, the amount of change in the tool push amount F is stabilized at substantially 0. However, as described above, the time required for measuring the tool length becomes long, The productivity of the workpiece W becomes extremely low. In Comparative Example 1, the four rotary tools 10 are rotated and used, but since the tool push amount F is not corrected, the tool push amount F becomes excessive and the surface portion Wa of the workpiece W cannot be appropriately modified. Further, there is a high possibility that the trace of the rotary tool 10 remains on the surface portion Wa of the workpiece W. Therefore, based on the test results of Comparative Examples 1 and 2, in this example, the tool length measurement is shortened and the tool push-in amount F is not excessively increased. This was achieved by changing the long detection period as described above.

  According to this surface treatment apparatus 1, since the position detecting means 5 and the push amount correcting means 6 are provided, the actual tip position with respect to the tip reference position of the rotary tool 10 attached to the spindle 2 and used for use is detected. Based on the tip position, the tool push amount F for pushing the rotary tool 10 into the surface portion Wa of the workpiece W during the surface treatment can be corrected so as to be the reference push amount FB, so that the surface portion Wa of the workpiece W can be reliably modified. The metal structure can be refined, and the durability can be improved.

  In addition, since the command means 8 is provided, the number of rotations Rn is equal to or less than a predetermined value (11 of the first predetermined value or 3 of the second predetermined value) for the detection cycle for detecting the actual tip positions of the four rotary tools 10. The four rotation tools 10 are output by outputting a command for operating the position detection means 6 and the push-in amount correction means 7 so that the detection period in the case of is shorter than the detection period in the case of being larger than a predetermined value. In consideration of the change tendency of the actual tip position with respect to the tip reference position of the rotary tool 10 when rotating the tool, the tool push amount F is maintained so as not to be larger than the reference push amount FB. The cycle of detecting the actual tip position of the rotary tool 10 is changed, and the position detection of the rotary tool 10 is appropriately thinned out, so that the total time required for this position detection is greatly reduced, and the work W is produced. Sex It is Mel possible.

  In addition, the command means 8 sets the detection cycle when the number of rotations Rn from the start of the machine tool 15 is larger than the first predetermined value (11 times) to a constant cycle (10 rotation cycles). Is larger than the predetermined value, the dimensional change due to the thermal expansion of the rotary tool 10 is small and the temperature change of the spindle 2 is also small. Therefore, the change in the actual tip position with respect to the tip reference position of the rotary tool 10 is small. The first predetermined value is set and maintained so that the tool push-in amount F does not exceed the reference push-in amount FB, and the position detection of the rotary tool 10 is thinned out at a constant cycle. it can.

  Further, when the number of rotations Rn from the start of the machine tool 15 is equal to or smaller than the second predetermined value (3), the position detecting unit 6 and the push-in amount correcting unit 7 are operated each time the number of rotations Rn increases by one. Therefore, the tool push-in amount F is not excessively larger than the reference push-in amount FB, particularly in a period in which the rate of increase in dimensional change accompanying the temperature change of the rotary tool 10 is large (the rotary tool 10 and the spindle 2 are in a cold state). Thus, it can correct | amend reliably so that the tool pushing amount F may be set to the reference pushing amount FB.

  That is, the detection cycle (1 rotation cycle) when the number of rotations Rn is 3 times (second predetermined position) or less is shorter than the detection cycle (4 rotation cycles or 10 rotation cycles) when it is greater than 3 times. In addition, the detection cycle (1 rotation cycle or 4 rotation cycle) in the case where the number of rotations Rn is 11 times (a constant value at the first place) or less is longer than the detection cycle (10 rotation cycles) in the case of being larger than the 11th rotation. As a result, when the surface treatment is performed on 400 workpieces W, the measurement of the tool length is required 52 times and can be omitted 348 times, and the time per rotation tool 10 required for the measurement of the tool length can be reduced. In the case of about 21 seconds, the production time can be shortened by 21 × 348 = 121.8 minutes.

  Thus, when the workpiece W is the cylinder head W of the engine, the inter-valve portion Wd between the air supply / exhaust ports Wb and Wc of the cylinder head W is subjected to surface treatment to increase the durability of the inter-valve portion Wd. Productivity of a quality cylinder head W can be increased.

Next, a modified form of the embodiment will be described.
1] The command means 8 may shorten the detection cycle as a whole as the number of the rotary tools 10 used for the surface treatment is smaller. For example, FIG. 12 shows a case where four rotary tools 10 are rotated and used on 88 workpieces W when the number of rotary tools 10 to be subjected to the surface treatment is three and four. Each time the surface treatment of the workpiece W is completed, the used rotary tool 10 is replaced to perform surface treatment, and the rotation detected for each of the workpieces W including one at the time of starting the machine tool 15 for one rotary tool 10. The change amount of the tool length of the tool 10 is shown.

  As can be seen from this figure, the amount of change in the tool length when the number of the rotary tools 10 to be subjected to the surface treatment is three is larger than that when the number is four, and until the machine tool 15 is stabilized from the start. The time will be longer. Therefore, the instruction means 8 appropriately sets the detection cycle according to the number of the rotary tools 10 used for the surface treatment by shortening the detection cycle as a whole as the number of the rotary tools 10 used for the surface treatment decreases. Thus, the tool push amount F can be reliably corrected to be the reference push amount FB so that the tool push amount F does not become larger than the reference push amount FB.

2] In this case, the command means 8 may increase the second predetermined value as the number of the rotary tools 10 used for the surface treatment is smaller. For example, when the number of the rotary tools 10 used for the surface treatment is 3, the second predetermined value is set to 4 or 5 times. That is, the smaller the number of rotary tools 10 used for the surface treatment, the greater the number of rotations Rn until the change of the actual tip position with respect to the tip reference position of the rotary tool 10 becomes smaller. Therefore, the second predetermined value is increased. Thus, the tool push amount F can be reliably corrected to the reference push amount FB so that the tool push amount F does not become larger than the reference push amount FB.

3] A spindle is rotatably attached to the robot arm, and a rotary tool 10 is detachably attached to the spindle, and the robot arm is operated to push the rotary tool 10 into the surface portion Wa of the workpiece W for surface treatment. You may give it.
4] In addition to the touch sensor 28, the actual tip position may be detected by imaging the rotating tool 10 with a camera and analyzing the image, or by imaging the spindle 2 and the rotating tool 10 with an infrared camera, The actual tip position (amount of change in the tool length) based on the temperature of the spindle 2 and the rotary tool 10 set in advance may be calculated from the temperatures of the spindle 2 and the rotary tool 10 obtained by the analysis.

5] In the flowchart of FIG. 9, the time from the end of the surface treatment to the start of the next surface treatment is measured, and when that time has elapsed (for example, 1-2 hours), the process returns to S1. It may be. Thereby, when the machine tool 15 is stopped due to a lunch break or the like, the spindle 2 and the rotary tool 10 are cooled, and thermal expansion occurs again for a certain period, so that the detection and correction of the tool length are required continuously. However, it becomes possible to cope with this.

6] The rotation tool 10 may be replaced each time a series of surface treatments are performed a plurality of times other than four times as in the main embodiment. In other words, even if the entire surface treatment is not completed for one workpiece W, the rotary tool 10 may be replaced during the process.
7] The number of rotating tools 10 used for the surface treatment is not limited to four in the main embodiment, but may be two, three, or five or more.
8] The first predetermined value and the second predetermined value can be changed as appropriate.

9] In addition, the present invention can be carried out with various modifications other than the above-mentioned disclosure within the scope of the present invention, and the rotary tool 10 can be applied to the surface portion Wa of various workpieces W other than the cylinder head. It can be applied to a surface treatment apparatus that pushes the tip of the workpiece W while rotating it, softens the surface portion Wa of the workpiece W by frictional heat, and plastically flows it to modify it.

It is a block diagram of the surface treatment apparatus of an Example. It is sectional drawing of the principal part of FIG. It is a side view of the front-end | tip part of a rotary tool. It is a side view of a surface treatment apparatus. It is a block diagram of a surface treatment apparatus. It is a side view of a touch sensor. It is a top view of a touch sensor. It is a top view of a cylinder head. It is a flowchart of the process which the control unit of a surface treatment apparatus performs. It is a contrast diagram of the Example which shows the variation | change_quantity of tool length, and a comparative example. It is a comparison figure of the Example which shows the variation | change_quantity of a tool pushing amount, and a comparative example. It is a comparison figure which shows the variation | change_quantity of the tool length in case the number of tools of a change form is 3 and 4.

Explanation of symbols

W Work 1 Surface treatment device 2 Spindle 6 Position detection means 7 Push amount correction means 8 Command means 10 Rotating tool 15 Machine tool

Claims (6)

While rotating a rotary tool removably attached to the spindle of a machine tool, the tip of the tool is pushed into the surface of the workpiece, and the surface of the workpiece is softened by frictional heat and subjected to surface treatment to improve it by plastic flow. In the surface treatment apparatus for a workpiece configured to rotate and use a plurality of rotary tools to be used for the surface treatment, and to replace the rotary tool used for use each time the series of surface treatments are performed one or more times,
Position detection means capable of detecting an actual tip position with respect to a predetermined tip reference position of a rotary tool attached to the spindle for use;
Based on the actual tip position detected by the position detection means, a push amount correction means for correcting the tool push amount for pushing the rotary tool into the surface portion of the workpiece during the surface treatment to be a reference push amount;
Command means for outputting a command for operating the position detection means and the push-in amount correction means, wherein the position detection means detects the actual tip positions of the plurality of rotary tools, and the detection period of the plurality of rotary tools. Command means for making the detection cycle when the number of rotations is equal to or less than a predetermined value shorter than the detection cycle when larger than the predetermined value;
A surface treatment apparatus for a workpiece, comprising:   The workpiece surface treatment apparatus according to claim 1, wherein the command unit sets the detection cycle when the number of rotations since the start of the machine tool is greater than a first predetermined value to a constant cycle. .   When the rotation number from the start of the machine tool is equal to or smaller than a second predetermined value that is smaller than the first predetermined value, the command unit is pushed in with the position detection unit every time the rotation number increases by one. 3. The workpiece surface treatment apparatus according to claim 2, wherein the amount correction means is operated.   4. The workpiece surface treatment apparatus according to claim 3, wherein the command means increases the second predetermined value as the number of rotating tools to be subjected to the surface treatment is smaller.   The workpiece surface treatment apparatus according to claim 1, wherein the command unit shortens the detection cycle as a whole as the number of rotating tools used for the surface treatment is smaller.   The work surface treatment apparatus according to claim 1, wherein the work is a cylinder head of an engine.

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