JP2009012163A - Honing processing method and honing processing control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a honing processing method and a honing processing control device, suitable for honing processing of a large processing margin. <P>SOLUTION: In this honing processing method, a honing head 3 is inserted into a gauge hole Dψ of the same dimension as a target processing diameter of a master gauge 30, and an expanding moving amount in a state of a grinding tool 7 contacting with an inner surface of the gauge hole Dψ by an expanding material, is stored as a target expanding amount, and the honing head 3 is inserted into a processing hole W1 of a workpiece W, and the honing processing of an inner surface of the processing hole W1 is performed by rotating the honing head 3 by expansively moving the grinding tool 7 outside in the radial direction by the expanding member arranged in the honing head 3, and the honing processing is completed in a stage when the expanding moving amount of the grinding tool 7 reaches the target expanding amount set by the master gauge 30. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a honing process method and a honing process control apparatus for precisely machining an inner surface of a cylinder.

  Conventionally, in cylinder bores of cylinder blocks, which are important parts that determine engine performance, it has been required to finish the roundness and cylindricity of machining diameter and shape accuracy with high precision, and honing is performed as the final finish. It is common. In the honing process that is performed, high-precision machining is realized by using a technique that performs machining while always measuring the bore diameter during machining, and finishes machining when the preset bore diameter is reached. (See Patent Document 1).

In order to measure the bore diameter during processing, a method of incorporating an air micro gauge in a honing head that is a processing tool is employed. In addition, as another method for measuring the bore diameter during processing, a method in which a honing head is provided with a plug gauge may be employed.
Japanese Patent Application Laid-Open No. 5-277728

  By the way, in the conventional example with the built-in air micro gauge, the back pressure of the air discharged through the air passage provided in the guide pad built in the honing head is detected, and the clearance between the guide pad and the cylinder bore is determined from the voltage. It is converted and converted into the cylinder bore diameter. However, in the above measurement method, there is an upper limit for clearance and voltage conversion, and when the clearance is too large (generally, about φ0.1 [mm] or more), the voltage cannot be accurately converted and the diameter cannot be measured. When the machining allowance by the honing process is large, there is a problem that cannot be applied.

  In addition, in the method in which the honing head is equipped with a plug gauge, the processing proceeds with the plug gauge portion being in contact with the upper end of the cylinder bore during processing, and the plug gauge portion reaches a predetermined cylinder bore diameter that can be inserted into the cylinder bore. The processing is completed at the stage where it is done. However, since the plug gauge is in contact with the cylinder bore, there is a possibility that the inner surface of the cylinder bore may be damaged when the plug gauge is inserted. In particular, when a thin coating layer is provided on the cylinder bore surface by thermal spraying or the like, there is a possibility that the coating layer may be peeled off by insertion of a plug gauge, and there is a problem that it is difficult to apply. Further, in this measurement method, only the upper part of the cylinder bore is measured. Therefore, when the machining allowance is large, the lower end of the cylinder bore is likely to have a small diameter (squeeze), but there is also a problem that it cannot be detected.

  From the above, when honing a cylinder bore with a large machining allowance, prepare multiple honing heads with different set machining diameters, and replace the tool with a honing head with a larger machining diameter each time machining progresses. It is necessary to equip the honing machine with a tool change function, or it is necessary to divide a processing station for each tool of different diameters, resulting in a problem that the tool change time loss and the capital investment amount increase.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a honing processing method and a honing processing control apparatus suitable for honing with a large machining allowance.

  According to the present invention, a honing head having a grindstone on an outer peripheral portion is inserted into a machining hole of a workpiece, and the grindstone is expanded and moved radially outward by an expansion member provided in the honing head, thereby adding an inner surface of the machining hole. This is a honing method in which honing is performed while pressing, and the honing head is inserted into a gauge hole having the same dimension as the target diameter of the master gauge, and the expansion member is expanded with the grindstone in contact with the inner surface of the gauge hole. The movement amount is stored as a target expansion amount, the honing head is inserted into the machining hole of the workpiece, the grindstone is expanded and moved radially outward by the expansion member provided in the honing head, and the honing head is rotated to perform the machining. Due to the deformation that occurs in the workpiece according to the machining reaction force against the machining hole of the grindstone that is detected at this time The grinding wheel forward amount, a value obtained by subtracting from the amount of the expanding movement of the grinding wheel was set as the honing completed at the stage of reaching the target expansion amount established by the master gauge.

  Therefore, in the present invention, the honing head is inserted into the gauge hole having the same dimension as the target processing diameter of the master gauge, and the extension movement amount in the state where the grindstone is in contact with the inner surface of the gauge hole by the extension member is set as the target extension amount. The honing head is inserted into the machining hole of the workpiece, the grindstone is expanded and moved radially outward by the expansion member provided in the honing head, and the honing head is rotated to perform the honing process on the inner surface of the machining hole. Then, the value obtained by subtracting the advancement amount of the grindstone due to the deformation generated in the workpiece in accordance with the processing reaction force to the processing hole of the grindstone detected at this time from the extension movement amount of the grindstone is the target extension amount set by the master gauge. The honing process is completed when it reaches. For this reason, even in honing with a large machining allowance, the diameter of the workpiece machining hole can be measured, and honing can be performed to a target inner diameter. In addition, errors due to deformation generated in the workpiece W due to the machining reaction force are eliminated, and the honing diameter of the workpiece machining hole W1 can be brought close to the target machining diameter with high accuracy.

  Hereinafter, a honing processing method and a honing processing control apparatus according to the present invention will be described based on each embodiment.

(First embodiment)
1 to 3 show an embodiment of a honing method and a honing processing control device according to the present invention, FIGS. 1 and 2 are system configuration diagrams of the honing processing control device of the present embodiment, and FIG. FIG. 4 is a perspective view of a master gauge used in the honing method according to this embodiment.

  As shown in FIGS. 1 and 2, the honing process control device 1 of the present embodiment is disposed at the tip of the drive cylinder 2 and is inserted into a hole W1 formed in the work W. The elevating drive motor 4 elevating the honing head 3 by elevating the drive cylinder 2, the stroke position detector 5 detecting the elevating position, and the rotary drive motor rotating the honing head 3 by rotating the drive cylinder 2. 6 and a feed composed of an NC servo motor that adjusts the radial position, that is, the feed position, of the plurality of honing grindstones 7 provided on the honing head 3 with respect to the head 3 by moving the push rod 8 in the drive cylinder 2 up and down. A drive motor 9 and a machining reaction force sensor 12 such as a piezo element for measuring a machining reaction force applied to the honing grindstone 7 are provided.

  The detection signals of the stroke position detector 5 and the machining reaction force sensor 12 are input to an arithmetic control unit 15 as a controller, and the arithmetic control unit 15 controls the control signals of the motors 5, 6, 9 based on these input signals. Is calculated and output to a drive circuit (not shown) of each of the motors 5, 6, 9. The feed position of the feed drive motor 9 constituted by the NC servo motor is fed back to the arithmetic control unit 15 as the NC data read by the built-in motor encoder. The arithmetic control unit 15 of the honing processing control device 1 is configured by an NC (Numerical Control) device that automatically controls the driving of the honing head 3 in response to input of processing command information indicated by numerical information. This NC device includes a motor control unit, a calculation control unit (control means), an input unit, and the like (not shown).

  The arithmetic control unit 15 controls the driving of the honing head 3 in an integrated manner. Based on the processing command information input as numerical information via the input unit, the rotation speed of the honing head 3 and the honing head 3 The machining conditions such as the raising / lowering movement position and the raising / lowering speed, the feed amount in the radial direction of the grindstone 7 and the feeding speed are optimized, and a control signal is output to each motor control unit to drive the honing head 3 based on the machining conditions. . In particular, regarding the feed control in the radial direction of the grindstone 7, the vertical direction of the grindstone base 22 in the grindstone mounting hole 21 (in order to allow the grindstone 7 to be fed to the inner surface of the hole W1 to be processed with an optimized feed amount ( The movement target amount of the push rod 8 is set in consideration of play in the axial direction of the drive cylinder 2).

  As shown in FIGS. 1 and 2, the honing head 3 includes a grindstone holder 13 that is connected to the tip of the drive cylinder 2. The push rod 8 is inserted into the drive cylinder 2, and the push rod 8 is movable with respect to the drive cylinder 2 on the central axis thereof in the axial direction (vertical direction) by the feed drive motor 9. ing.

  At the lower end of the push rod 8, tapered extruding portions 23 that are reduced in diameter toward the lower side are provided in two upper and lower stages. On the other hand, the lower end portion of the drive cylinder 2, that is, the grindstone holder 13, is provided with a plurality of grindstone mounting holes 21 penetrating in the radial direction on the side wall thereof arranged at equal intervals in the circumferential direction. A grindstone base 22 is mounted in the grindstone mounting hole 21 so as to be displaceable in the radial direction of the honing head 3, and the grindstone 7 is fixed to the outer end surface of each grindstone base 22. The inner end surfaces of these grinding wheel bases 22 are formed in a two-step upper and lower taper shape so as to coincide with the outer end surfaces of the two upper and lower push-out portions 23, and the push-out portion 23 is lowered by the push rod 8. Each of the grinding wheel bases 22 is pushed out radially outward by these pushing portions 23, whereby the grinding wheel diameter (the diameter of the circumscribed circle of all the grinding wheels 7) is increased.

  The grinding wheel base 22 is located radially outward, and has an outer peripheral side grinding wheel base 22A provided with the grinding wheel 7 fixed integrally to the outer surface by adhesion or the like, and an inner circumference that is taper-engaged with the upper and lower two-stage pushing portions 23. A working reaction force sensor 12 composed of the load cell or piezo element or the like is interposed and fixed therebetween. These machining reaction force sensors 12 detect the machining reaction force F received by the grindstone 7 from the workpiece W, and the detection signal is amplified by the amplifier 12B and then input to the arithmetic control unit 15.

  A honing method by the honing processing control apparatus 1 having the above configuration will be described below based on the processing procedure shown in FIG. In the honing method according to the present embodiment, as shown in FIG. 4, a master gauge 30 having a gauge hole Dφ formed in the same diameter as the target machining diameter is manufactured in advance, and the master gauge 30 is processed for each machining cycle of the workpiece W. The target machining diameter of the honing process control device 1 is set by the gauge 30, and the hole inner surface formed in the workpiece W is honed so as to have the set target machining diameter.

  First, in step S1, the honing head 3 of the honing process control device 1 is inserted into the gauge hole Dφ of the master gauge 30 and, as shown in step S2, the push rod 8 and the tapered pushing portion 23 are moved by the feed drive motor 9. The grindstone base 22 and the grindstone 7 that are extruded downward and are in taper contact are expanded radially outward. In accordance with the feed amount of the feed drive motor 9, the reading position by the motor encoder built in the NC servo motor of the feed drive motor 9 is fed back to the arithmetic control unit 15 as NC data.

  When the expanded grindstone 7 comes into contact with the inner surface of the gauge hole Dφ of the master gauge 30, the reaction force detected by the machining reaction force sensor 12 (piezo element) disposed between the outer peripheral side grindstone base 22A and the inner peripheral side grindstone base 22B is generated. The pressure rises from zero output to a predetermined positive pressure value and is input to the arithmetic control unit 15. The arithmetic control unit 15 stores the NC data (reading position) of the feed drive motor 9 at the time when the reaction force from the machining reaction force sensor 12 is output as the NC extension target base point. The feed drive motor 9 is stopped in response to the rising of the detected reaction force, and the feed drive motor 9 is reversely rotated to retract the push rod 8, the pushing portion 23, and the internal / external grinding wheel base 22 to return to the standby position, step S3. Proceed to

  The reaction force detected by the processing reaction force sensor 12 at the time point is generated in a state where the gaps (clearances) between the push rod 8, the pushing portion 23, and the inner and outer grinding wheel bases 22 are filled. Yes, it is a relatively small value compared to the actual processing reaction force, and does not cause the push rod 8 to be bent or the master gauge 30 to be deformed.

  Next, as shown in step S3, the honing head 3 is inserted into the machining hole W1 formed in the workpiece W, the feed drive motor 9 is operated, and the push rod 8, the pushing portion 23, and the inner and outer grindstone base 22 are fed out. The grindstone 7 is brought into contact with the inner surface of the processing hole W1, and the honing head 3 is moved up and down by the elevating drive motor 4 while the drive cylinder 2 and the honing head 3 are rotated by the main shaft rotating motor 6, thereby honing the inner surface of the hole. According to the difference between the feed amount (NC data) at the stage where the grindstone 7 contacts the inner surface of the work hole W1 of the workpiece W by the feed drive motor 9 (the rising stage of the machining reaction force F) and the NC extension target base point, An appropriate feed amount is set by the calculation control unit 15, the feed speed of the feed drive motor 9 is set, and the grindstone 7 is pressed against the inner surface of the hole W1 to be machined. Further, the reading position by the motor encoder incorporated in the NC servo motor of the feed drive motor 9 is fed back to the calculation control unit 15 as NC data, and the machining reaction force F is fed back from the machining reaction force sensor 12 to the calculation control unit 15. Is done.

  The arithmetic control unit 15 determines the workpiece W based on the read position (NC data) by the motor encoder incorporated in the NC servo motor of the feed drive motor 9 fed back and the machining reaction force F from the machining reaction force sensor 12. The hole diameter of the processed hole W1 is calculated (step S4).

  The calculation of the hole diameter of the machining hole W1 is performed by using the machining reaction force F detected by the machining reaction force sensor 12 as follows: a bending δ1 generated in the push rod 8 and a deformation δ2 generated in the workpiece W. It is calculated by adding to the reading position (NC data) by the motor encoder built in the motor.

  FIG. 5 shows that when a processing reaction force F is applied to the grindstone 7 during processing, a strain δ1 is generated in the push rod 8 due to the action of the processing reaction force F. Therefore, the NC command value to the feed drive motor 9 and the actual grindstone 7 A difference of [NC command value−retraction amount of the grinding wheel due to strain δ1 = actual extended movement amount] occurs. The strain δ1 is generated in proportion to the processing reaction force F as shown in FIG. Therefore, the actual extended movement amount of the grindstone 7 is a value obtained by subtracting the grindstone retraction amount due to the strain δ1 of the push rod 8 generated by the machining reaction force F from the NC command value. In particular, when the sharpness of the grindstone 7 is low or when the machining NC command value is large (when the machining load is large), the machining reaction force F becomes relatively large, and the strain amount δ1 of the push rod 8 becomes large. The difference between the NC command value and the actual extension movement amount (diameter) increases.

  FIG. 7 shows a state during processing in which the grindstone 7 is in contact with the inner surface of the hole W1 to be processed. To be deformed as shown by the two-dot chain line. The deformation amount δ2 increases in proportion to the processing reaction force F as shown in FIG. Accordingly, the actual extended movement amount of the grindstone 7 is a value obtained by subtracting the grindstone advance amount due to the deformation amount δ2 of the workpiece W generated by the machining reaction force F from the NC command value. Even in this case, when the sharpness of the grindstone 7 is low or when the machining NC command value is large (when the machining load is large), the machining reaction force F becomes relatively large and the deformation amount δ2 of the workpiece W becomes large. Therefore, the difference between the NC command value and the actual extension movement amount (diameter) becomes large.

  Further, the amount of deformation δ2 of the workpiece W with respect to the processing reaction force F also varies depending on the shape of the workpiece W. For example, in a honing process of an engine cylinder bore, in a top deck type in which both ends of a cylinder forming a cylinder bore are connected to a cylinder block, the portion adjacent to the upper and lower decks is relatively small and is axially extended from the upper and lower decks. As it leaves, it tends to become relatively large at the intermediate position. Further, in the open deck type, the upper end of the cylinder bore tends to be large, and varies depending on the connection state of the cylinder by the cylinder block.

  Therefore, the calculation of the hole diameter of the processing hole W1 is based on the processing reaction force F detected by the processing reaction force sensor 12 from the reading position (NC data) by the motor encoder built in the NC servomotor of the feed drive motor 9. It is calculated by subtracting the grinding wheel retraction amount caused by the bending δ1 generated in the push rod 8 and the bending δ2 generated in the workpiece W.

  The calculated hole diameter of the machining hole W1 is compared with the NC expansion target base point in step S5. If the NC expansion target base point is not reached, steps S3 to S5 are repeatedly executed. When the hole to be machined W1 is a cylinder bore honing process, the process proceeds to step S6 when the calculated hole diameter of the machining hole W1 reaches the NC expansion target base point in all axial regions, and the honing process is completed. The In step S6, the feed amount by the feed drive motor 9 is returned to the initial position, the rotation of the drive cylinder 2 is stopped by the spindle rotation motor 6, and the honing head 3 is extracted from the machining hole W1 of the workpiece W by the lift drive motor 4. Raise. The machining hole W1 of the workpiece W subjected to the honing process returns to its deformation by removing the machining reaction force F, and a target inner diameter is obtained. The machining accuracy of the machining hole W1 of the obtained workpiece W can be assured as a fine boring accuracy (range 0.03).

  As described above, the target machining diameter of the honing process control device 1 is set by the master gauge 30 for each machining cycle of the workpiece W, and the inner surface of the hole formed in the workpiece W so that the set target machining diameter is obtained. Since the honing is performed, the wear amount of the grindstone 7 accompanying the honing of the cylinder bore per cylinder block is within 1 μm, and the inner diameter after the processing can be set to a level with no problem.

  As described above, honing, which has a large machining allowance, has a high technical hardware for thinning the thin film sprayed metal, for example, when thin film spraying of hard metal is performed on the inner surface of the cylinder bore of the cylinder block. Therefore, it is effective to perform the honing process according to the present embodiment, which can realize the sizing process even if the machining amount is large, as a pre-process for performing the finishing honing.

  In the present embodiment, the following effects can be achieved.

  (A) The honing head 3 provided with the grindstone 7 on the outer peripheral portion is inserted into the machining hole W1 of the workpiece W, and the grindstone 7 is provided in the radial direction by the expansion members (8, 22, 23) provided in the honing head 3. The honing process method or honing process control device 1 performs honing while pressurizing the inner surface of the processing hole W1 by expanding the outer side of the processing hole W1. A machining reaction force detecting means 12 for detecting force is provided, the honing head 3 is inserted into a gauge hole Dφ having the same dimension as the target machining diameter of the master gauge 30, and the grindstone 7 is brought into contact with the inner surface of the gauge hole Dφ with the expansion member. The amount of extension movement in the state of being made is stored as a target extension amount, the honing head 3 is inserted into the machining hole W1 of the workpiece W, and the grindstone 7 is moved to the honing head. The machining reaction force detected by the machining reaction force detection means 12 is carried out by performing an honing process on the inner surface of the machining hole W1 by rotating the honing head 3 by expanding it radially outward by an expansion member provided in the lid 3. Accordingly, the honing process is completed when the value obtained by subtracting the amount of advancement of the grindstone caused by deformation generated in the workpiece W from the amount of extension of the grindstone 7 reaches the target amount of extension set by the master gauge 30. . For this reason, even in the honing process with a large machining allowance, the diameter of the workpiece machining hole W1 can be measured, and honing can be performed to the target inner diameter. In addition, errors due to deformation generated in the workpiece W due to the machining reaction force are eliminated, and the honing diameter of the workpiece machining hole W1 can be brought close to the target machining diameter with high accuracy.

  (A) The honing head 3 is provided with a machining reaction force detection means 12 for detecting a machining reaction force generated in the grindstone 7 with respect to the workpiece machining hole W1, and according to the machining reaction force detected by the machining reaction force detection means 12. By expanding the honing process when the value obtained by subtracting the retraction amount of the grindstone due to the strain generated in the expansion member from the expansion movement amount of the grindstone 7 reaches the target expansion amount set by the master gauge 30, the expansion member is completed. The error due to the distortion caused by the machining reaction force is eliminated, and the honing diameter of the workpiece machining hole W1 can be brought close to the target machining diameter with high accuracy.

  (C) The expansion member includes a feed drive motor 9 made of an NC servo motor, a push rod 8 for transmitting the feed amount of the NC servo motor to the honing head 3, and a grindstone from the honing head 3 according to the movement amount of the push rod 8. 7 is composed of an extrusion unit 23 for feeding out in the radial direction and a grindstone base 22, so that the feed control amount can be easily determined based on the output value from the motor encoder of the NC servo motor, and the bending of the push rod 8 as the expansion member The influence due to can be easily subtracted from the output value of the encoder.

(Second Embodiment)
9 to 13 show a second embodiment of a honing method and a honing process control device according to the present invention, FIG. 9 is a front view and a side view showing a grindstone shape in the present embodiment, and FIG. 10 is in the present embodiment. FIG. 11 is a characteristic chart showing a data table of a target machining diameter and an extended movement amount of a grinding wheel according to the sharpness of the grindstone, FIG. 11 is a time chart showing a change in sharpness of the grindstone, and FIG. 12 shows a procedure of the honing method according to this embodiment. FIG. 13 is a process diagram showing a procedure of a multi-step honing method inserted between the honing methods shown in FIG. In the present embodiment, a configuration in which the honing diameter is brought close to the target diameter with high accuracy in consideration of the sharpness of the honing grindstone is added to the first embodiment. The same devices as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified.

  The honing process control apparatus 1 in the present embodiment is configured in the same manner as the honing process control apparatus shown in FIG. Further, as shown in FIG. 9, the grindstone 7 attached to the honing head 3 has a uniform thickness in the radial direction, but has a trapezoidal shape that becomes wider as it moves toward the tip side of the honing head 3. Forming. According to this shape, since the margin for removing the lower end of the processed hole W1 cannot be secured sufficiently, the lower end portion of the processed hole W1 is difficult to be cut, and the problem that the processed hole W1 tends to have a squeezed dimension is solved. be able to.

  In addition, although not shown in figure, in the grindstone 7 with a uniform width dimension, short stroke (reducing the speed | rate of a feed operation) and dwell operation (Dwell) are implemented so that a lower end part of a bore may be cut actively. . The dwelling operation means that in machining, the cutting operation is stopped with the cutting edge of the tool applied and the feed operation is stopped. In the honing process of the cylinder bore, the time when the cutting edge (honing grindstone 7) contacts the lower end by temporarily stopping the vertical stroke (feed) operation of the honing head at the lower end in order to actively cut the lower end of the bore. By relatively increasing (that is, the processing work amount), the problem that the cylinder bore tends to be in a constricted shape is solved.

  However, in this embodiment, by making the grindstone 7 trapezoidal, deterioration of processing conditions such as an increase in cycle time due to short strokes and dwell operations and uneven wear of the grindstone are improved.

  Further, in the honing method, the completed diameter of the hole W1 to be processed varies depending on the sharpness of the grindstone 7 to be honed even with the same extended movement amount of the grindstone 7. That is, in FIG. 10, the diameter dimension of the hole W1 to be machined with respect to the extension movement amount of the grindstone 7 in FIG. When the sharpness of the grindstone 7 is low, the inclination gradient rises as shown by the line A in the figure, whereas when the sharpness of the grindstone 7 is low, as shown by the line C in the figure. , The rising slope is low. In addition, the line B in a figure shows the diameter dimension of the processing hole W1 with respect to the extended movement amount of the grindstone 7 by the standard stable sharpness grindstone 7. FIG.

  In the honing method according to this embodiment, attention is paid to the sharpness of the grindstone 7 described above. That is, the extended movement amount of the grindstone 7 for machining the machining hole W1 to the target machining diameter is reduced when the sharpness of the grindstone 7 is good, and is increased when the sharpness of the grindstone 7 is low. Is.

  In addition, honing is started to determine the sharpness of the grindstone 7, and the honing is interrupted and honed at an intermediate stage when the extended movement amount of the grindstone 7 reaches a preset (intermediate) extended movement amount X. The grindstone 7 is retracted and separated from the surface of the machining hole W1, and the actual diameter of the machining hole W1 is measured to determine the machining hole size relative to the extended movement amount of the grinding stone 7, that is, the sharpness of the grindstone 7. Is. Further, the target extension amount (setting (intermediate) extension movement amount X + remaining extension movement amount) that reaches the target machining diameter by the subsequent honing is set according to the sharpness of the grindstone 7.

  In the honing method of the present embodiment, in order to achieve the above-mentioned problem, prior to the honing process, the grindstone 7 (line A) having a good sharpness, the grindstone 7 having a low sharpness (line C), and an intermediate between them. Corresponding to each of a plurality of sharp grinding wheels 7 in the stage (in the illustrated example, only one “standard” sharp grinding stone 7 (line B) is shown), “working hole diameter—grinding wheel extension movement amount”. Create a data table. Specifically, it is created by measuring honing processing performed using a plurality of grindstones 7 having different sharpness in advance and the machining hole size of the obtained workpiece. As shown in FIG. 10, the “processed hole diameter—grinding wheel extended movement amount” data table may be a characteristic diagram showing a processed hole diameter with respect to the extended movement amount of the grindstone 7, and may be a preset setting ( Intermediate) A data file of the measured diameter of the intermediate hole for the expansion movement amount X and the target expansion amount for the target hole diameter may be used.

  FIG. 11 shows the change in the sharpness of the grindstone 7 along with the elapsed time due to the change in the diameter of the processing hole W1 that is honed by the same extended movement amount of the grindstone 7. In addition, D shows the average value (target sharpness) of the sharpness of the grindstone 7. As shown in FIG. 11, the sharpness of the grindstone 7 is the highest in a new state, and shifts to a stable sharpness during the habituation processing by a predetermined number of workpieces. However, as the workpiece is processed, chips of the workpiece W and crushed abrasive powder are clogged between the abrasive grains, and the sharpness gradually decreases. Further, the sharpness of the grindstone 7 with reduced sharpness is restored again by removing the chips of the workpiece W clogged between the abrasive grains and the pulverized abrasive powder by sharpening with a soft truing tool.

  As described above, the sharpness of the normal grindstone 7 gradually changes due to the sharpening or clogging of the grindstone 7. Therefore, it is desirable to update the setting of the sharpness of the grindstone 7 by the above-described “working hole diameter—extended movement amount of the grindstone 7” data table every time the honing is performed on the predetermined number of workpieces W. For this reason, in the honing method of the present embodiment, the sharpness setting honing method shown in FIG. 12 for performing the honing of the workpiece W while confirming the sharpness of the grindstone 7 being used, and the sharpness are set. The sharpening-set honing method shown in FIG. 13 for honing the workpiece W with the grindstone 7 is performed. The former honing method is performed each time the latter honing method is performed at a plurality of cycle times, thereby maintaining the accuracy of the diameter of the honing hole W1 while maintaining the total honing cycle time. It can be shortened.

  In the following, the honing method according to this embodiment will be described first with respect to the sharpness setting honing method shown in FIG. 12, and then the sharpness-set honing method shown in FIG.

  The honing method for sharpness setting shown in FIG. 12 is, first, in step S10, the grindstone 7 with good sharpness (line A), the grindstone 7 with low sharpness (line C) described in FIG. A data table of “machined hole diameter−extended movement amount of the grindstone 7” is created in correspondence with the plurality of sharp grindstones 7 in the intermediate stage.

  Next, in step S11, the honing head 3 of the honing process control apparatus 1 is inserted into the gauge hole Dφ of the master gauge 30, and the push rod 8 and the tapered pushing portion 23 are pushed downward by the feed drive motor 9 to make a taper contact. The grindstone table 22 and the grindstone 7 are expanded radially outward. In accordance with the feed amount of the feed drive motor 9, the reading position by the motor encoder built in the NC servo motor of the feed drive motor 9 is fed back to the arithmetic control unit 15 as NC data.

  When the expanded grindstone 7 contacts the inner surface of the gauge hole Dφ of the master gauge 30, the reaction force detected by the machining reaction force sensor 12 (piezo element) disposed between the outer peripheral side grindstone base 22A and the inner peripheral side grindstone base 22B. Rises from zero output to a predetermined positive pressure value and is input to the arithmetic control unit 15. The arithmetic control unit 15 stores the NC data (reading position) of the feed drive motor 9 at the time when the reaction force from the machining reaction force sensor 12 is output as the NC extension target base point. The feed drive motor 9 is stopped in response to the rising of the detected reaction force, and the feed drive motor 9 is reversely rotated to retract the push rod 8, the pushing portion 23, and the internal / external grinding wheel base 22 to return to the standby position, step S12. Proceed to

  The reaction force detected by the processing reaction force sensor 12 at the time point is generated in a state where the gaps (clearances) between the push rod 8, the pushing portion 23, and the inner and outer grinding wheel bases 22 are filled. Yes, it is a relatively small value compared to the actual processing reaction force, and does not cause the push rod 8 to be bent or the master gauge 30 to be deformed.

  Next, as shown in step S12, the honing head 3 is inserted into the machining hole W1 formed in the workpiece W, the feed drive motor 9 is operated, and the push rod 8, the extrusion unit 23, and the internal / external grinding wheel base 22 are fed out. The grindstone 7 is brought into contact with the inner surface of the processing hole W1. Then, while the drive cylinder 2 and the honing head 3 are rotated by the main shaft rotating motor 6, the honing head 3 is moved up and down by the lifting drive motor 4 to perform the honing process on the inner surface of the hole. According to the difference between the feed amount (NC data) at the stage where the grindstone 7 contacts the inner surface of the work hole W1 of the workpiece W by the feed drive motor 9 (the rising stage of the machining reaction force F) and the NC extension target base point, An appropriate feed amount is set by the calculation control unit 15, the feed speed of the feed drive motor 9 is set, and the grindstone 7 is pressed against the inner surface of the hole W1 to be machined. Then, the reading position by the motor encoder incorporated in the NC servo motor of the feed drive motor 9 (the extended movement amount of the grindstone 7) is fed back to the arithmetic control unit 15 as NC data, and the processing reaction force F is processed by the processing reaction force sensor. 12 is fed back to the arithmetic control unit 15 (step S13).

  In step S14, it is determined whether or not the grinding wheel expansion movement amount in step S13 has reached a preset (intermediate) expansion movement amount X. If the setting (intermediate) expansion movement amount X has not been reached, it is determined. When Step S13 to Step S14 are repeatedly executed and the hole to be machined W1 is the honing of the cylinder bore, the calculated wheel extension movement amount is set to the set (intermediate) extension movement amount X in all axial regions. When it reaches, the process proceeds to step S15.

  In step S15, the grinding wheel expansion movement is stopped, the grinding wheel expansion movement amount X at that time is stored, and the process proceeds to step S16.

  In step S16, the grindstone 7 is retracted by a certain amount to a position where the grindstone 7 and the work inner surface do not contact each other. Further, whether or not the grindstone 7 is really in contact with the inner surface of the workpiece hole W1 is confirmed by a machining reaction force sensor. If the grindstone 7 is in contact, the grindstone 7 is retracted by a certain amount again. By releasing the contact state between the grindstone 7 and the inner surface of the work hole W1 of the work W, the distortion of the work W and the tool accumulated during the honing process is once canceled.

  In step S17, the grindstone 7 is re-expanded and stopped when the output from the machining reaction force sensor rises to bring the grindstone 7 into contact with the machining hole W1, and the amount of expansion movement of the grindstone 7 at that time is calculated. Output to the control unit 15. The arithmetic control unit 15 measures the actual machining hole diameter (intermediate measurement machining hole diameter) of the work hole W1 of the workpiece based on the input movement amount of the grindstone 7 at that time. Depending on the sharpness of the grindstone 7, the actual machining hole diameter with respect to the set (intermediate) extended movement amount X changes under the influence of the workpiece W accumulated during machining and the distortion of the tool.

  In step S18, which grindstone 7 of the data table corresponds to the sharpness of the actual machining hole diameter based on the grinding wheel expansion movement amount X stored in step S15 based on the “processing hole diameter—grinding wheel expansion movement amount” data table. Select. That is, in FIG. 10, for the setting (intermediate) extended movement amount X of the grindstone 7, for example, if the intermediate measurement processing hole diameter is “a” dimension, it is determined that the sharpness has the characteristic A, and the intermediate measurement processing hole If the diameter is the “b” dimension, it is determined that the sharpness has the characteristic B, and if the intermediate measurement hole diameter is the “c” dimension, the sharpness is determined to have the characteristic C. Further, the sharpness of the grindstone 7 in the honing process in the next step of step S23 is set by correcting the determined sharpness (or corrected target expansion amount).

  Further, according to the expansion movement amount (setting (intermediate) expansion movement amount X) of the grindstone 7 stored in the step S15 and the sharpness characteristic of the grindstone 7 set by the intermediate measurement processing hole diameter, “processing hole diameter—grinding wheel expansion”. Based on the “movement amount” data table, the remaining wheel extension movement amount to the target machining hole diameter is calculated. That is, in FIG. 9, if the sharpness characteristic of the grindstone 7 is “A”, the remaining extension movement amount is set to “A ′”, and if “B”, the remaining extension movement amount is set to “B ′”. If “C”, the remaining extended movement amount is set to “C ′”. Therefore, the (correction) target expansion amount until the target machining hole diameter is reached is “X + A ′” for the characteristic “A”, “X + B ′” for the characteristic “B”, depending on the sharpness characteristics of the grindstone 7. ", ... will be set. X is the set (intermediate) extended movement amount in step S14.

  In step S19, the feed drive motor 9 is operated to feed out the push rod 8, the extruding portion 23, and the inner and outer grindstone bases 22 to bring the grindstone 7 into contact with the inner surface of the machining hole W1 again. While the head 3 is rotated, the honing head 3 is moved up and down by the lift drive motor 4 to resume the honing processing of the hole W1 to be processed. According to the difference between the feed amount (NC data) at the stage where the grindstone 7 contacts the inner surface of the work hole W1 of the workpiece W by the feed drive motor 9 (the rising stage of the machining reaction force F) and the NC extension target base point, An appropriate feed amount is set by the calculation control unit 15, the feed speed of the feed drive motor 9 is set, and the grindstone 7 is pressed against the inner surface of the hole W1 to be machined. Further, a reading position (grinding wheel extension movement amount) by a motor encoder built in the NC servo motor of the feed drive motor 9 is fed back to the arithmetic control unit 15 as NC data, and a machining reaction force F is fed from the machining reaction force sensor 12. Feedback is provided to the arithmetic control unit 15 (step S20).

  In step S21, it is determined whether or not the grinding wheel expansion movement amount in step S20 has reached the (correction) target expansion amount set in step S18. If (correction) the target expansion amount has not been reached, step S21 is performed. Steps S20 to S21 are repeatedly executed. When the hole to be machined W1 is the cylinder bore honing process, the process proceeds to step S22 when the calculated extension movement amount of the grindstone 7 reaches the (correction) target extension amount in all axial regions.

  In step S22, the feed amount by the feed drive motor 9 is returned to the initial position, the rotation of the drive cylinder 2 is stopped by the spindle motor 6, and the honing head 3 is extracted from the machining hole W1 of the workpiece W by the lift drive motor 4. The honing process in this process is completed.

  In the sharpening-set honing method shown in FIG. 13, the honing head 3 is inserted into the machining hole W1 formed in the workpiece W in step S31, the feed drive motor 9 is operated, and the push rod 8 / extrusion unit 23 is operated. -Sending out the inner / outer whetstone base 22 and bringing the whetstone 7 into contact with the inner surface of the processing hole W1 again. Then, while the drive cylinder 2 and the honing head 3 are rotated by the spindle rotation motor 6, the honing head 3 is moved up and down by the lift drive motor 4 to start honing of the inner surface of the hole. According to the difference between the feed amount (NC data) at the stage where the grindstone 7 contacts the inner surface of the work hole W1 of the workpiece W by the feed drive motor 9 (the rising stage of the machining reaction force F) and the NC extension target base point, An appropriate feed amount is set by the calculation control unit 15, the feed speed of the feed drive motor 9 is set, and the grindstone 7 is pressed against the inner surface of the hole W1 to be machined. Further, the reading position by the motor encoder incorporated in the NC servo motor of the feed drive motor 9 (extended movement amount of the grindstone 7) is fed back to the arithmetic control unit 15 as NC data and the processing reaction force F is processed by the processing reaction force sensor. 12 is fed back to the arithmetic control unit 15 (step S32).

  In step S33, it is determined whether or not the grinding wheel expansion movement amount has reached the (correction) target expansion amount based on the sharpness of the grinding wheel 7 set in step S23. If the grinding wheel expansion movement amount does not reach the (correction) target expansion amount, steps S32 to S33 are repeatedly executed. When the hole W1 to be machined is a cylinder bore honing process, the process advances to step S34 when the calculated extension movement amount of the grindstone 7 reaches the (correction) target extension amount in all axial regions.

  In step S34, the feed amount by the feed drive motor 9 is returned to the initial position, the rotation of the drive cylinder 2 is stopped by the spindle rotating motor 6, and the honing head 3 is extracted from the machining hole W1 of the workpiece W by the lift drive motor 4. The honing process in this process is completed.

  When the honing method for sharpness setting shown in FIG. 12 is executed every time honing is performed, the sharpness of the grindstone 7 used for the honing can be corrected each time, and the workpiece after honing is processed. Hole diameter accuracy and cylindricity can be improved.

  In addition, the sharpness setting honing method shown in FIG. 13 and the sharpness setting honing method shown in FIG. 12 are performed each time the former honing is performed in a plurality of steps. Thus, it can also be carried out after the sharpening work of the grindstone 7 used for the honing process or after exchanging the grindstone 7. In this method, the sharpness of the grindstone 7 used in the honing process can be corrected each time, the accuracy and cylindricity of the hole diameter after the honing process can be improved, and the sharpness determination of the grindstone 7 can be determined. The processing cycle time can be shortened compared to what is performed each time processing is performed.

  In the present embodiment, in addition to the effects (a) to (c) in the first embodiment, the following effects can be achieved.

  (D) In the intermediate stage where the extension movement amount of the grindstone 7 reaches the target extension amount set by the master gauge 30, the machining hole diameter of the intermediate stage obtained by honing is measured, and the extension movement amount of the grindstone 7 In order to correct the target expansion amount based on the processing hole diameter at the intermediate stage with respect to the above, the variation of the processing hole diameter with respect to the expansion movement amount of the grindstone 7 that changes due to the sharpness of the grindstone 7 can be corrected, and the honing processed work The accuracy of the hole diameter can be improved.

  (E) a data table in which a plurality of correlations of the diameter of the hole to be processed with respect to the amount of movement of the grindstone 7 corresponding to the change in sharpness of the grindstone 7 are stored, and the target expansion amount is corrected from Since it is made based on the correlation of the diameter of the hole to be machined with respect to the extended movement amount of the grindstone 7 due to the sharpness of the grindstone 7 selected based on the processing hole diameter at the intermediate stage, Variations in the diameter of the hole to be processed can be corrected, and the accuracy of the diameter of the hole to be processed that has been subjected to honing can be improved.

  (F) Measurement of the diameter of the hole to be processed in the intermediate stage is performed again with the grindstone 7 of the honing head 3 retracted and once detached from the inner surface of the hole to be processed W1, and the distortion of the workpiece or tool is once canceled. Since measurement is performed with a grindstone in contact with the inner surface of the hole, distortion of the workpiece W or tool accumulated during machining can be canceled once, and remaining machining can be performed stably, so that the accuracy of the finished workpiece can be improved.

  (G) In the honing process for the workpiece W in a plurality of processes after the next process performed after the completion of the honing process in which the target expansion amount has been corrected, honing is performed by performing the honing process based on the corrected target expansion amount. During the honing process of a plurality of steps in which the change in the sharpness of the grindstone 7 used for machining does not become large, the measurement of the diameter of the machining hole in the intermediate stage can be omitted, and the sharpness of the grindstone 7 is determined every time the honing is performed. The processing cycle time can be shortened with respect to an object.

  (G) Since the grindstone 7 is formed in a trapezoidal shape that becomes wider as it moves to the tip side of the honing head 3, the removal allowance at the lower end of the hole W1 to be processed cannot be secured sufficiently. It is possible to solve the problem that the lower end portion is difficult to cut and the hole W1 is likely to have a squeezed dimension. Moreover, the cylindricality of the completed hole W1 to be processed can be secured, and deterioration of processing conditions such as an increase in cycle time due to a short stroke and a dwell operation and uneven wear of the grindstone 7 can be improved.

The system block diagram of the honing process control apparatus which shows one Embodiment of this invention. The system block diagram of the honing process control apparatus which similarly includes a process reaction force detection means. Process drawing which shows the procedure of the honing processing method of this embodiment. The perspective view of the master gauge used for the honing processing method of this embodiment. Explanatory drawing explaining the mechanism of pushrod distortion | strain (delta) 1 generation | occurrence | production. The characteristic view which shows the relationship between the process reaction force F and pushrod distortion | strain amount (delta) 1. Explanatory drawing explaining the deformation | transformation mechanism of the process hole of a workpiece | work. The characteristic view which shows the relationship between the process reaction force F and the bore deformation amount (delta) 2. The front view (A) and side view (B) which show the grindstone shape used for the honing process control apparatus which shows 2nd Embodiment of this invention. The characteristic view which shows the data table of the target process diameter according to the sharpness of the grindstone in this embodiment, and the extended movement amount of a grindstone. The time chart which shows the change of the sharpness of the grindstone. Process drawing which shows the procedure of the honing processing method in this embodiment. Process drawing which shows the procedure of the honing processing method of the several process inserted between the honing processing methods shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Honing process control apparatus 2 Drive cylinder 3 Honing head 4 Lift drive motor 5 Stroke position detector 6 Spindle motor 7 Grinding wheel 8 Push rod 9 Feeding drive motor 12 Processing reaction force sensor 13 Grinding wheel holder 15 Computation control part as control means

Claims (15)

A honing head equipped with a grindstone on the outer periphery is inserted into the machining hole of the workpiece, and the grinding wheel is expanded and moved radially outward by an expansion member provided in the honing head, so that honing is performed while pressurizing the inner surface of the machining hole. Honing processing method
The honing head is inserted into a gauge hole having the same dimension as the target processing diameter of the master gauge, and the extension movement amount in a state where the grindstone is in contact with the inner surface of the gauge hole with the extension member is stored as a target extension amount.
The honing head is inserted into the machining hole of the workpiece, the honing head is rotated by moving the grinding wheel radially outward by an expansion member provided in the honing head, and the honing process is performed on the inner surface of the machining hole.
The value obtained by subtracting the advancement amount of the grindstone due to deformation generated in the workpiece in accordance with the machining reaction force against the machining hole of the grindstone detected at this time has reached the target extension amount set by the master gauge. Honing method characterized in that honing is completed in stages.   Honing is performed when the value obtained by subtracting the grinding wheel retraction amount due to strain generated in the expansion member according to the detected processing reaction force from the expansion movement amount of the grinding wheel reaches the target expansion amount set by the master gauge. The honing method according to claim 1, wherein the honing method is completed. In the intermediate stage where the expansion movement amount of the grindstone reaches the target expansion amount set by the master gauge, the hole diameter of the intermediate stage obtained by honing is measured,
3. The honing method according to claim 1, wherein a target expansion amount is corrected based on a hole diameter in the intermediate stage with respect to the expansion movement amount of the grindstone. A plurality of data tables storing a correlation of the diameter of a hole to be processed with respect to the extended movement amount of the grindstone corresponding to the change in sharpness of the grindstone,
The target expansion amount is corrected based on the correlation of the hole diameter to be processed with respect to the amount of expansion movement of the grinding wheel due to the sharpness of the grinding wheel selected based on the intermediate processing hole diameter from the data table. The honing method according to claim 3.   The measurement of the hole diameter in the intermediate stage is performed by retracting the honing head's grindstone to once remove it from the inner surface of the hole to be worked, and once again canceling the distortion of the workpiece or tool, The honing method according to claim 3, wherein the measurement is performed by contacting the honing method.   The honing process is performed based on the corrected target expansion amount in a honing process for a workpiece in a plurality of steps after the next process performed after completion of the honing process in which the target expansion amount is corrected. The honing method according to any one of claims 3 to 5.   The honing method according to any one of claims 1 to 6, wherein the grindstone is formed in a trapezoidal shape that becomes wider as it moves toward the tip side of the honing head. A honing head equipped with a grindstone on the outer periphery is inserted into the machining hole of the workpiece, and the grinding wheel is expanded and moved radially outward by an expansion member provided in the honing head, so that honing is performed while pressurizing the inner surface of the machining hole. Honing process control device that performs
The honing head is provided with a processing reaction force detecting means for detecting a processing reaction force against the processing hole of the grindstone,
The honing head is inserted into a gauge hole having the same dimension as the target processing diameter of the master gauge, and the extension movement amount in a state where the grindstone is in contact with the inner surface of the gauge hole with the extension member is stored as a target extension amount.
During the honing process in which the honing head is inserted into the machining hole of the workpiece, the grinding wheel is caused by the radial deformation generated in the workpiece in accordance with the machining reaction force detected by the machining reaction force detection means from the extended movement amount of the grinding wheel. A honing process control device comprising: control means for determining that the honing process is completed when a value obtained by subtracting the advance amount reaches a target expansion amount set by the master gauge.   The control means is a target extension set by the master gauge, which is a value obtained by subtracting the grinding wheel retraction amount due to strain generated in the expansion member in accordance with the machining reaction force detected by the machining reaction force detection means from the extension movement amount of the grinding wheel. The honing process control apparatus according to claim 8, wherein the honing process is determined to be completed when the amount is reached. The expansion member includes a feed drive motor composed of an NC servo motor, a push rod that transmits the feed amount of the NC servo motor to the honing head, and an extrusion unit that feeds the grindstone in the radial direction from the honing head according to the movement amount of the push rod. And a grinding wheel stand,
The honing process control device according to claim 8 or 9, wherein the strain generated in the expansion member is a bending of the push rod. In the intermediate stage where the expansion movement amount of the grindstone reaches the target expansion amount set by the master gauge, the measuring means comprises a measuring means for measuring the hole diameter of the intermediate stage obtained by honing.
10. The honing process control according to claim 8, wherein the control unit corrects the target expansion amount based on the diameter of the drilled hole in the intermediate stage with respect to the expansion movement amount of the grindstone by the measuring unit. apparatus. The control means includes a data table in which a plurality of correlations of the hole diameter to be processed with respect to the extended movement amount of the grindstone are stored corresponding to changes in the sharpness of the grindstone,
The target expansion amount is corrected based on the correlation of the hole diameter to be processed with respect to the amount of expansion movement of the grinding wheel due to the sharpness of the grinding wheel selected based on the intermediate processing hole diameter from the data table. The honing process control apparatus according to claim 11.   The measurement of the hole diameter in the intermediate stage is performed by retracting the honing head's grindstone to once remove it from the inner surface of the hole to be worked, and once again canceling the distortion of the workpiece or tool, The honing process control apparatus according to claim 11, wherein the honing process control apparatus is configured to perform contact measurement.   In the honing process for a workpiece in a plurality of steps after the next process performed after completion of the honing process in which the target expansion amount is corrected, the control means performs the honing process based on the corrected target expansion amount. The honing process control apparatus according to any one of claims 11 to 13, wherein the honing process control apparatus is characterized.   The honing process control device according to any one of claims 8 to 14, wherein the grindstone is formed in a trapezoidal shape that becomes wider as it moves to a tip side of the honing head.

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