JP2007098523A - Method for judging service life of broach, broach quality control device, and broaching device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for judging a service life of a broach for exactly judging whether or not the service life of the broach expires and whether or not cutting amount, etc. of each cutting edge is in a normal state without directly measuring the broach, a broach quality control device and a broaching device. <P>SOLUTION: Back component force to be cutting resistance load acting in the direction orthogonal to an axial direction of the broach 101 is measured according to moving in the cutting direction. The actually measured value is compared with a reference value to be the back component force of the broach 101 when flank wear amount (s) of the cutting edge 110 is a wear limit value. When the actually measured value is the reference value or less, it is judged that the service life of the broach 101 does not expire. When the actually measured value exceeds the reference value, it is determined that the service life of the broach 101 expires. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a broach life determination method for determining the life of a broach based on a cutting resistance load acting on the broach, a broach quality management device for managing the quality of the broach, and a broach processing device.

  The broach has a plurality of cutting edges aligned in the axial direction thereof, and each cutting edge is formed to have a predetermined cutting amount with respect to the immediately preceding cutting edge. Therefore, for example, when abnormal wear occurs in a certain cutting edge n due to chipping or the like, the cutting edge n + 1 immediately after that becomes a predetermined double cutting amount, and the wear of the cutting edge n + 1 also progresses and wears abnormally. The cutting edges n + 2, n + 3,... Move one after another, and the amount of wear of each cutting edge reaches the wear limit value in a shorter time than in normal wear, leading to the life of the broach.

  In addition, when abnormal wear occurs in a certain cutting edge, vibration is generated in the broach at the time of cutting, and the cutting edge may be lost due to such vibration, and the life of the broach may be shortened in a shorter time than normal wear. In addition, if the cutting edge is severely damaged, it is difficult to regenerate with a sharpening blade and the broach may not be reused.

  Even when there is a cutting edge with a cutting depth that exceeds the specified value, the blade may be worn abnormally or damaged by vibration. There is a risk of reaching the end of life.

  By the way, conventionally, the tool material which constitutes each cutting edge of the broach is made of a cemented carbide, and by coating with a hard film, a technique for suppressing abnormal wear such as chipping and extending the tool life is known (for example, Patent Document 1). Such a carbide broach is more likely to chip the cutting edge than a normal broach when it is cut with an excessive wear state or an excessive depth of cut or when vibration such as impact is applied.

  Therefore, it is desirable to always keep track of the state of wear of the cutting edge, the presence or absence of defects, and whether the cutting amount of the cutting edge is within the specified range, but the broach has a plurality of cutting edges. It is cumbersome and costly to perform inspections such as direct measurement, observation, and inspection on all these cutting edges. Therefore, conventionally, the number of times of machining by broach is set, and periodic inspection is performed in which the broach is directly inspected for each number of times of machining (prior art 1).

  In addition, among the cutting resistance load acting on the broach by providing a load sensor etc. directly under the workpiece, the main component force that is the cutting resistance load acting in the axial direction of the broach is measured, and the measured main component force is preset. In the case of exceeding the above value, a technique (conventional technique 2) for determining that the wear amount of the broach is at the wear limit is generally known.

  In addition, in a broaching device that uses a drive motor to move the broach in the cutting direction, the current value of the drive motor is replaced with the main component force at the time of cutting, and the current value is set in advance. A technique (conventional technique 3) for determining that the wear amount of the broach is at the wear limit when the value exceeds the above-mentioned value is generally known.

JP 2001-239425 A

  In the prior art 1, since the broach is regularly inspected, the state of the cutting edge cannot always be grasped. Therefore, for example, when the progress of wear is fast, there is a possibility that a large amount of wear will occur during the next inspection, resulting in a situation in which regeneration by blade sharpening is impossible.

  In both of the prior art 2 and the prior art 3, the main component force which is a cutting resistance load acting in the axial direction of the broach is detected, and whether the cutting edge is at the wear limit based on the detected main component force. However, since the main component force has a small degree of change in accordance with the wear state of the cutting edge, and particularly the degree of change from 0 to the wear limit value, such a main component force is small. It is difficult to determine whether the cutting edge is at the wear limit based on the component force.

  The main component force has a small degree of change when cutting from the front end to the rear end of the broach, and there are abnormal cutting edges such as an excessive cutting amount among a plurality of cutting edges. It cannot be determined based on the change in main component.

  The present invention has been made in view of these problems, and an object of the present invention is to determine the life of a broach and accurately determine the life of the broach and the state of each cutting edge without directly measuring the broach. Another object is to provide a broach quality control device and a broach processing device.

  The invention of the broach life determination method according to claim 1 for achieving the above object is a cutting resistance load acting on the broach in accordance with movement in the cutting direction and acting in a direction perpendicular to the axial direction of the broach. The actual measured value of the back component force is compared with the reference value which is the back component force when the flank wear amount of the broaching edge is the wear limit value. In some cases, it is determined that the life of the broach has not been reached, and when the measured value exceeds the reference value, it is determined that the life of the broach has been reached.

  The invention of the broach quality control device described in claim 2 is a cutting load acting on the broach according to the movement in the cutting direction by moving at least one of the broach and the workpiece in the cutting direction of the broach. Back component force measuring means that measures the back component force acting in the direction orthogonal to the axial direction of the broach, the actual measured value of the back component force actually measured by the back component force measuring unit, and the flank wear of the cutting edge of the broach When the measured value is less than the reference value, it is determined that the broach has not reached the end of its life. And broach life judging means for judging the life of the broach.

  According to a third aspect of the present invention, in the broach quality control device according to the second aspect, the flank wear amount of the cutting edge of the broach is estimated by estimating the flank wear amount of the cutting edge based on the actually measured value of the back component force. Compare the reference value, which is the back component force when the estimated flank wear amount is, with the measured value, and the measured value from the start of movement in the cutting direction of the broach to the end of movement is less than the reference value. When there is a part larger than a predetermined value, it has a cutting edge state judging means for judging that the cutting edge existing in the part is in an abnormal state.

  The invention according to claim 4 is the broach quality control device according to claim 2 or 3, wherein the reference value is a specific cutting resistance load which is a cutting resistance load per unit area of a portion to be cut and removed by the cutting edge of the broach. And the removal area cut and removed by the cutting edge.

  The invention of the broaching device according to claim 5 is a control means for performing control to disable execution of broaching when the broach quality control device according to claim 2 or 3 determines that the life of the broach has been reached. It is provided with.

  The invention of the broaching device according to claim 6 performs control to disable the execution of broaching when the broach quality control device according to claim 3 determines that the cutting edge is in an abnormal state. Control means is provided.

  The invention according to claim 1 measures the back component force acting in the direction perpendicular to the axial direction of the broach among the cutting resistance loads acting on the broach by movement in the cutting direction, and the measured actual value and Then, by comparing with the reference value which is the back component force when the flank wear amount of the cutting edge of the broach is the wear limit value, it is determined whether or not the life of the broach is reached. Since the back component force acting in the direction perpendicular to the axial direction of the broach has a greater degree of change in the cutting resistance load according to the flank wear amount than the main component force acting in the axial direction of the broach, It is possible to accurately determine whether or not the flank wear amount of the cutting edge of the broach has reached the wear limit value. Therefore, it is possible to accurately determine whether or not the broach has reached the end of its life without directly measuring, observing or inspecting the broach.

  According to the second aspect of the invention, the back force acting in the direction perpendicular to the axial direction of the broach is measured by the back force measuring means among the cutting resistance load acting on the broach by movement in the cutting direction. To do. And the measured value of the measured back component force is compared with the reference value that is the back component force of the broach when the flank wear amount of the cutting edge is the wear limit value. When the measured value exceeds the reference value, it is determined that the broach has reached the end of its life. Since the back component force acting in the direction perpendicular to the axial direction of the broach has a greater degree of change in the cutting resistance load according to the flank wear amount than the main component force acting in the axial direction of the broach, It is possible to accurately determine whether or not the flank wear amount of the cutting edge of the broach has reached the wear limit value. Therefore, it is possible to accurately determine whether or not the broach has reached the end of its life without directly measuring, observing or inspecting the broach.

  According to the third aspect of the present invention, the flank wear amount of the cutting edge is estimated based on the actually measured back component force, and the reference is the back component force of the broach having the estimated flank wear amount. If there is a place where the measured value is greater than the reference value by more than the reference value between the start of movement in the cutting direction of the broach and the end of movement, comparing the measured value with the measured value, the cutting edge present at the location Is determined to be in an abnormal state. Therefore, even if the flank wear amount of each cutting edge of the broach is less than the wear limit value and the life of the broach is not exhausted, abnormalities in the cutting amount, cutting width and flank wear amount of each cutting edge will be detected. Can be found. Thereby, it is possible to confirm whether or not each cutting edge of the broach is in a normal state, for example, when the broach is new or when the blade is sharpened again.

  The invention described in claim 4 shows an example of a method for calculating the reference value. According to this, the reference value is a cutting resistance load per unit area of the portion of each cutting edge of the broach to be removed by cutting. Is calculated based on the specific cutting resistance load and the removal area removed by each cutting edge.

  According to the fifth aspect of the present invention, when the broach life determining means of the broach quality control device determines that the life of the broach has been reached, control is performed to disable the execution of broaching. Therefore, broaching by a broach whose life has expired can be prevented. As a result, the degree of damage to the broach can be suppressed to a low level, and it is possible to prevent the cutting edge from being worn down to a situation where it is difficult to regenerate by the re-blading. Further, it is possible to prevent the work from being troubled by broaching with a broach that has reached the end of its life, and the work can be machined accurately and stably.

  According to the sixth aspect of the present invention, the broaching device of the present invention can be used when the cutting edge state judging means of the broach quality control device according to the third aspect determines that the cutting edge is in an abnormal state. Control to disable the processing. Therefore, broaching by a broach whose cutting edge is in an abnormal state can be prevented. As a result, the degree of damage to the broach can be suppressed to a low level, and it is possible to prevent the cutting edge from being worn down to a situation where it is difficult to regenerate by the re-blading. In addition, it is possible to prevent the workpiece from being troubled by broaching with a broach having an abnormal cutting edge, and the workpiece can be machined accurately and stably.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram for explaining the configuration of a broaching apparatus according to the present embodiment, FIG. 2 is a side view of the broach, FIG. 3 is a cross-sectional view taken along the line AA in FIG. FIG. 5 is a cross-sectional view taken along the line BB of FIG. 4, and FIG. 6 is a block diagram showing an outline of a control system of the broach quality control device and broach processing device.

  The broaching device 1 is a so-called drawing type inner surface broaching device that performs broaching on the inner peripheral surface of the workpiece W, and a broach 101 is detachably attached as shown in FIG. As shown in FIG. 2, the broach 101 is provided with a front grip portion 102 for pulling the broach 101 in the cutting direction which is the front side in the axial direction at one end, and a rear grip portion for pulling back the broach 101 at the other end. 109 is provided.

  In the broach 101, a cutting blade portion 104 is provided between the front grip portion 102 and the rear grip portion 109. The cutting blade portion 104 is for forming a keyway on the inner peripheral surface of an inner diameter hole formed in advance on the workpiece W, and is composed of a rough cutting blade group 105 and a finishing blade group 106, and a finishing blade group. A final finishing blade group 107 that performs finishing with particularly high accuracy is formed in 106.

  In the roughing blade group 105 and the finishing blade group 106 of the cutting blade portion 104, a plurality of cutting blades 110 protrude from the cylindrical body portion along the direction perpendicular to the axial direction of the broach 101, and the axis of the broach 101 It is arranged in a line along the direction.

  The outer diameter of the body portion is set to a size that is inserted into the inner diameter hole of the workpiece W and guided by the inner peripheral surface of the inner diameter hole. As shown in FIGS. 3 to 5, the cutting edge 110 has a substantially rectangular parallelepiped shape in which a cross section in a direction orthogonal to the axial direction forms a substantially rectangular shape, and a rake face 111 is provided on the front side in the axial direction. The flank 112 is formed on the radially outer side, and an edge portion (blade edge) 113 is formed by the ridge line portion between the rake face 111 and the flank 112.

  As shown in FIG. 5, the rake surface 111 of the cutting edge 110 is gradually rearward in the axial direction as it moves in the direction orthogonal to the axial direction of the broach 101 and from the radial center side of the broach 101 toward the radial outer side. It has a planar shape inclined by a rake angle α with respect to the direction orthogonal to the axis L of the broach 101.

  The flank 112 of the cutting edge 110 is formed to be inclined so as to shift to the axial center side of the broach 101 as it moves from the axial front side to the axial rear side. In FIG. 3, the symbol h represents the cutting width of the cutting edge 110, and the symbol t in FIG. 4 represents the cutting amount.

  Further, a front guide portion 103 is formed between the front grip portion 102 and the cutting blade portion 104, a rear guide portion 108 is formed between the cutting blade portion 104 and the rear grip portion 109, and the broach 101 is The workpiece W is positioned coaxially with the inner diameter hole of the workpiece W.

  The broach 101 is made of an ultrafine particle cemented carbide and coated with a hard film. As the ultrafine particle cemented carbide, for example, a WC fine powder having a particle diameter of 1 μm or less sintered with Co of 12% or less as a binder is used. For the hard coating, for example, (TiAl) N having an oxidation start temperature of 800 ° C. or higher is used.

  As shown in FIG. 1, the broaching apparatus 1 includes a main body 2 having a horizontally extending table surface 2a, a work holding means 3 for holding a work W at the center of the table surface 2a, and cutting of the broach. Broach holding means 4 that holds the broach 101 vertically so that the direction is a direction to move downward from above, and drive means 5 that moves the broach holding means 4 downward along the axial direction of the broach 101. (See FIG. 6).

  A through hole 2b having a size capable of inserting the broach 101 is formed in the main body 2 so as to penetrate vertically, and an upper end of the through hole 2b is opened at the center of the table surface 2a. The work holding means 3 is provided so as to be movable in the horizontal direction integrally with the work W along the table surface 2 a of the main body 2.

  The broach holding means 4 holds the front grip part 102 of the broach 101 inserted through the through hole 2b of the main body part 2 and the rear grip part 109 of the broach 101 and holds the broach 101 in the vertical posture state. It has a support part (not shown) which supports so that it may become. The ram portion 4a is provided on the main body portion 2 so as to be slidable up and down.

  As shown in FIG. 6, the drive unit 5 includes an actuator 5 a such as a hydraulic cylinder or an electric motor that is driven in response to a control signal from a control unit 11 described later, and a ram portion 4 a of the broach holding unit 4. Is moved from above to below along the axial direction of the broach 101 with a predetermined tensile force, and the broach 101 is moved in the cutting direction.

  Further, the broaching device 1 includes a control unit 11 that controls the cutting speed, cutting force, and the like by the broach 101 and a broach quality management unit (broach quality management device) 21 that manages whether the quality of the broach 101 is appropriate. And a load sensor 31 that detects a cutting resistance load acting on the broach 101 by the movement of the broach 101 in the cutting direction, and a movement position sensor 32 that detects a movement position of the broach 101 relative to the workpiece W.

  The load sensor 31 is attached between the work holding means 3 and the main body 2 as shown in FIG. And the 3 axis | shaft which consists of the 1st axial direction along the axial direction of the broach 101, the 2nd axial direction orthogonal to the 1st axial direction, and the 3rd axial direction orthogonal to the 1st axial direction and the 2nd axial direction It is comprised by the piezoelectric element which can measure the load of a direction.

  The movement position sensor 32 is attached between the ram part 4a of the broach holding means 4 and the main body part 2 (not shown in FIG. 1), and can detect the position of the ram part 4a with respect to the main body part 2, for example, linear It is composed of a scale and the like.

  The control means 11 is constituted by a sequence program computer or a relay circuit. As shown in FIG. 6, an operation panel 12 for inputting and operating set values such as machining conditions and workpiece types is connected to the input side of the control means 11. On the side, driving means 5 for operating the actuator 5a and a display unit 14 are connected. The display unit 14 includes a display or the like, and displays various setting values, operating conditions, and the like, and is provided on the operation panel 12.

  The control means 11 controls the actuator 5a to be actuated by the drive means 5 based on the set values such as machining conditions, and to move the broach 101 in the cutting direction via the broach holding means 4. The control means 11 is connected to the broach quality management means 21 so as to be capable of two-way communication. The control means 11 receives the broach quality management information from the broach quality management means 21 and, based on the broach quality management information, the broach for the next workpiece. A process for determining whether or not processing is possible is performed.

  The broach quality management means 21 is constituted by a PC (personal computer), and is installed in a state where a software program for broach quality management can be executed. The broach quality management means 21 executes a software program for broach quality management, so that an internal function of the broach quality management means 21 is a cutting resistance measuring unit (back force measuring means) 22 and a broach moving position measurement. Unit 23, broach life determination processing unit (broach life determination means) 24, cutting edge state determination processing unit (cutting edge state determination means) 25, and time measurement unit 26 are conceptually configured.

  The time measuring unit 26 performs a process of measuring the broach moving time from the start of movement of the broach 101 in the cutting direction to the end of movement by the driving unit 5.

  The cutting resistance measuring unit 22 acts in a direction orthogonal to the axial direction of the broach 101 among cutting resistance loads acting on the broach 101 based on a detection signal from the load sensor 31 capable of measuring the load in the three axial directions. The back component force is obtained and stored in the memory in a form associated with the elapsed time from the movement start time to the movement end time in the cutting direction.

  FIG. 7 is a diagram for explaining the cutting resistance load acting on the broach 101 during broaching. When the broach 101 is moved in the cutting direction, each cutting edge 110 cuts the workpiece W, and a cutting resistance load acts on the broach 101. As shown in FIG. 7, the cutting resistance load includes a main component force acting along the axial direction of the broach 101 and in a direction opposite to the cutting direction, and a back force acting in a direction orthogonal to the axial direction of the broach 101. Divided into power. In the present invention, the life of the broach 101 and the state of each cutting edge 110 are determined using the back component force of the main component force and the back component force.

  The broach movement position measurement unit 23 performs a process of measuring the movement position of the broach 101 in the cutting direction based on the detection signal from the movement position sensor 32. The movement position of the broach 101 is stored in the memory of the broach quality management means 21 in a form associated with the elapsed time from the start of movement in the cutting direction.

  The broach life determination processing unit 24 obtains the back force corresponding to the moving distance of the broach 101 based on the processing result of the cutting force measuring unit 22 and the processing result of the broach moving position measuring unit 23 and is converted into two-dimensional data. A process of storing the actual measured value in the memory of the broach quality management means 21 is performed.

  Then, the measured value is compared with a reference value that is the back component force of the broach 101 when the flank wear amount s of the cutting edge 110 is the wear limit value, and when the measured value is less than the reference value, the broach When the measured value exceeds the reference value, it is determined that the life of the broach 101 is reached. When it is determined that the broach 101 has not reached the end of its life, a process for transmitting the determination result to the control means 11 as broach quality management information is performed.

  The reference values are the specific cutting resistance load that is the cutting resistance load (back force) per unit area of the portion where the cutting edge 110 cuts and removes the workpiece W (cutting amount t × cutting width h), and the cutting edge 110 removes the cut. It is calculated based on the removal area to be performed. In the present embodiment, the reference value is calculated from a value where the flank wear amount s (see FIG. 5) of each cutting edge 110 is 0 to a predetermined wear limit value (for example, 100 μm). The two-dimensional data is stored in the memory as the back component force corresponding to the movement distance of the broach 101.

  The cutting edge state determination processing unit 25 determines whether each cutting edge is in a normal state by determining that the broach life determination processing unit 24 has not reached the life of the broach 101. The cutting edge state determination processing unit 25 estimates the flank wear amount s of the cutting edge 110 based on the measured actual value of the back component force, and uses the back component force of the broach 101 having the estimated flank wear amount s. A certain reference value is compared with an actual measurement value. And when there is a place where the actual measurement value is larger than the reference value by a predetermined value or more between the start of movement of the broach 101 in the cutting direction and the end of movement, the cutting edge 110 existing in that place is in an abnormal state. When it is determined that there is no portion where the actual measurement value is greater than the reference value by a predetermined value or more, it is determined that each cutting edge 110 is in a normal state. And the process which transmits these judgment results to the control means 11 as brooch quality management information is performed.

  Next, a broaching method for the workpiece W using the broaching apparatus 1 having the above configuration will be described. First, as shown in FIG. 1, the work W is placed on the work holding means 3 to hold the work W, and the broach 101 is held by the broach holding means 4 so that the cutting direction of the broach 101 is downward. Let Then, the type of the workpiece, the specifications of the broach 101, the processing conditions, and the like are input from the operation panel 12 to the control means 11.

  Next, when a machining operation start signal is input from the operation panel 12 at a predetermined timing, a drive signal is output from the control means 11, the actuator 5a is actuated by the drive means 5, and the broach holding means 4 is moved downward. Thus, the broach 101 is moved in the cutting direction with a predetermined tensile force and tensile speed. Broaching is performed on the inner peripheral surface of the workpiece W by the movement of the broach 101 in the cutting direction. In the present embodiment, a keyway is formed on the inner peripheral surface of the workpiece W.

  The processing operation start signal is also input from the control means 11 to the broach quality management means 21. Then, in response to the input of the start signal of the machining operation, the measurement of the back component force acting on the broach 101 and the measurement of the movement position of the broach 101 are performed from the movement start point of the broach 101 to the movement end point. Based on this, a measured value of the back component force is obtained.

  Then, the broach life determination processing unit 24 determines whether or not the broach 101 is at the end of its life. Here, the reference value that is the back component force of the broach 101 when the flank wear amount s is the wear limit value is compared with the actually measured value, and when the actually measured value exceeds the reference value of the wear limit value. When it is determined that the service life of the broach 101 is equal to or less than the reference value of the wear limit value, it is determined that the broach 101 has not reached the service life. When it is determined that the life of the broach 101 has been reached, the determination result is transmitted to the control means 11 as broach quality management information.

  When receiving the broach management judgment information having the judgment result of the life of the broach 101, the control means 11 performs control to disable the broaching to the next workpiece W so as to prohibit the broaching by the broach 101. At the same time, error information is displayed on the display unit 14, and a warning alarm or the like is sounded to notify the operator.

  Accordingly, it is possible to accurately determine whether or not the broach 101 is at the end of its life every time broaching is performed on the workpiece W without directly measuring, observing, and inspecting the broach 101, and managing the quality of the broach. be able to. Further, broaching by the broach 101 with the flank wear amount s of each cutting edge 110 exceeding the wear limit value can be prevented, the degree of damage to the broach is suppressed, and the broach 101 to a situation where it is difficult to regenerate by re-blading. It is possible to prevent the cutting edge 110 from being worn. Thereby, the workpiece | work W can be processed accurately and stably.

  On the other hand, when the actual measurement value is equal to or less than the reference value of the wear limit value by the determination process by the broach life determination processing unit 24 and it is determined that the broach 101 has not reached the life, the cutting edge state determination processing unit 25 Processing for determining whether or not each cutting edge 110 of the broach 101 is in a normal state is performed.

  Here, first, the flank wear amount s of the cutting edge 110 is estimated based on the actually measured value of the back component force. The flank wear amount s is collated with an actual measurement value and a reference value from a value where the flank wear amount s of each cutting edge 110 stored in the memory of the broach quality control means 21 is 0 to a wear limit value. The reference value closest to the actually measured value is specified, and the flank wear amount s of the broach 101 is estimated based on the specified reference value.

  Next, a reference value (= specified reference value) that is the back component force of the broach 101 having the estimated flank wear amount s is compared with an actual measurement value, and from the movement start time of the broach 101 to the movement end time. It is determined whether or not there is a location where the actually measured value is larger than the reference value by a predetermined value or more, for example, 10% or more of the reference value.

  When there is a location where the actual measurement value is greater than the reference value by a predetermined value or more from the start of movement of the broach 101 to the end of movement, the cutting blade 110 corresponding to the location is specified, and the cutting blade 110 is identified. Is determined to be in an abnormal state, and each cutting edge 110 is determined to be in a normal state when there is no portion where the actual measurement value is greater than the reference value by a predetermined value or more. Then, these determination results are transmitted to the control means 11 as broach quality management information.

  When the control means 11 receives the broach quality management information having the determination result that each cutting edge 110 is in the normal state, the control means 11 determines that the quality of the broach 101 is appropriate and performs broaching on the next workpiece W. Perform the process to enable it.

  On the other hand, when receiving broach quality control information having a determination result that the cutting edge 110 is in an abnormal state, the control means 11 cannot perform broaching on the next workpiece W in order to prohibit broaching by the broach 101. And error information is displayed on the display unit 14, and a warning alarm is sounded to notify the operator.

  Therefore, even when the life of the broach 101 is not exhausted, the abnormal state of each cutting edge 110 can be found. Accordingly, every time broaching is performed on the workpiece W without directly measuring, observing, or inspecting the broach 101, an abnormality occurs in the cutting amount t, the cutting width h, and the flank wear amount s of each cutting edge. It is possible to check whether or not the broach 101 is in quality. In addition, for example, an abnormality such as an excessive cutting amount t of the cutting edge 110 may be found when the broach 101 is new or when the blade is sharpened again.

  In this embodiment, a material equivalent to cemented carbide P30 is used for the broach 101, and a material around the hardened steel HRC60 is used for the workpiece W. And the cutting speed of the broaching apparatus 1 was set to 60 m / min.

  The cutting amount t of each cutting edge 110 of the broach 101 is generally 10 to 50 μm, which is extremely small as compared with turning or milling, and a large amount of wear on the cutting edge occurs on the flank 112.

FIG. 8 is a graph showing the relationship between the flank wear amount s and the cutting resistance load. As shown in FIG. 8, the main component force acting in the axial direction of the broach 101 among the cutting resistance loads acting on the broach 101 is 910 N / mm ² when the flank wear amount s is 15 μm, and 100 μm. There are 1750 N / mm ^2, the increase amount is 840N / mm ^2. In contrast, the back component force acting in a direction perpendicular to the axial direction of the broach 101 when flank wear s of 15μm is at 810N / mm ^2, when the 100μm is 3300N / mm ^2, the increase The amount is 2490 N / mm ² . Therefore, it can be seen that the change in the cutting resistance load when the flank wear amount s is 0 to 100 μm is greater in the back component force than in the main component force. In the present invention, paying attention to this point, the life of the broach 101 and whether each cutting edge 110 is in a normal state are determined based on the back component force.

  When the flank wear amount s of the cutting edge 110 is 100 μm or more, the cemented carbide broach 101 used in the present embodiment is abruptly worn and is largely lost, and it is difficult to regenerate with the blade sharpener 101. Cannot be reused. Therefore, when the wear amount of the flank 112 is 100 μm, the wear limit value of the flank wear amount s is set as the wear limit value, and when the broaching is performed with the broach 101 having the flank wear amount s of each cutting edge 110 of 100 μm, It is set as the standard value.

FIG. 9 is a diagram showing the relationship between the cutting resistance load and the broach movement distance in the broaching of the workpiece W having a cutting length of 50 mm. The vertical axis of the graph represents the cutting resistance load kN / mm ² , and the horizontal axis represents the broach movement length mm. The dotted line shown in FIG. 9 is an actual measurement value, and the solid line is a reference value. In this embodiment, a reference value having the flank wear amount s of 20 μm is specified as the most approximate reference value. And P part in a figure protrudes from the reference value of 20 micrometers, and becomes a big value beyond a predetermined value (for example, 10% of reference values). Therefore, it can be determined that there is an abnormality in the cutting edge 110 located at the corresponding location.

  FIG. 10 is a diagram illustrating the relationship between the cutting resistance load and the broach movement distance in the broaching of the workpiece W having a cutting length of 200 mm. The dotted line shown in FIG. 10 is a measured value, the solid line is a reference value of 100 μm where the flank wear amount s is the wear limit value, and the alternate long and short dash line is a reference value where the flank wear amount s is 50 μm. In this embodiment, a flank wear amount s of 50 μm is specified as the most approximate reference value, and the flank wear amount s, which is a wear limit value, is shown together with a reference value of 100 μm.

  According to this, it can be seen that the actually measured value is smaller than the reference value of 100 μm which is the wear limit value. Therefore, it is accurately determined that the flank wear amount s of each cutting edge 110 is less than the wear limit value and the broach 101 has not reached the end of its life, in other words, the broach 101 is continuously usable. Can do.

  And it turns out that Q part shown by FIG. 10 protrudes from the reference value of 50 micrometers. Therefore, it can be easily grasped that the flank wear amount s of the corresponding cutting edge 110 is worn larger than 50 μm. In addition, when the broach 101 was actually measured directly, the flank wear amount s other than the Q portion was 40 to 50 μm, but the flank wear amount s of the cutting edge 110 corresponding to the Q portion was 70 μm. It was confirmed that the reference value exceeded 50 μm.

  According to the broach quality control device, the back component force acting on the broach 101 is measured by movement in the cutting direction, the measured value of the back component force, and the flank wear amount s of the cutting edge 110 are worn. By comparing with the reference value which is the back component force of the broach 101 at the limit value, it is possible to accurately determine whether or not the broach 101 is at the end of its life without directly measuring the broach 101 or the like.

  Further, the flank wear amount s of the cutting edge 110 is estimated based on the measured actual value of the back component force, and a reference value and an actual value that are the back component force of the broach 101 having the estimated flank wear amount s are calculated. And when there is a place where the actual measurement value is larger than the reference value by a predetermined value or more between the start of movement of the broach 101 in the cutting direction and the end of movement, the cutting edge 110 existing in the place is in an abnormal state. It is judged that. Therefore, even when the life of the broach 101 is not exhausted, it is possible to find an abnormality in the cutting amount t, the cutting width h, and the flank wear amount s of each cutting edge 110.

  When the broach quality management unit 21 determines that the quality of the broach 101 is not appropriate, the control unit 11 performs control to disable the broaching process, and therefore the flank wear amount s of each cutting edge 110 is determined. Can be prevented from being broached into the work W by the broach 101 whose wear limit has been exceeded, that is, the so-called broach 101 having expired, or the broach 101 in which the cutting edge 110 is in an abnormal state. Therefore, the degree of damage to the broach 101 can be suppressed to a small level, and the cutting edge 110 of the broach 101 can be prevented from being worn down to a situation where it is difficult to regenerate by re-sharpening. In addition, it is possible to prevent the work W from being defective due to broaching by the broach 101 whose quality is not appropriate, and the work W can be processed accurately and stably.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the case where the load sensor 31 is attached between the work holding means 3 and the main body 2 has been described as an example. However, as long as the back component force acting on the broach 101 can be detected. Good.

  FIG. 11 is a diagram illustrating a configuration example in which the load sensor 31 is attached to the broach guide 6. In addition, the detailed description is abbreviate | omitted by attaching | subjecting the same code | symbol to the component similar to the broaching apparatus 1 shown in FIG. In this configuration example, the broach guide 6 is provided so as to be movable in the horizontal direction above the workpiece W, and the load sensor 31 is provided so as to detect a horizontal cutting resistance load acting on the broach guide 6. It has been. Therefore, it is possible to detect the back force acting on the broach 101 by the movement of the broach 101 in the cutting direction.

It is a figure explaining the structure of the broaching apparatus concerning this Embodiment. It is a side view of a broach. It is the sectional view on the AA line of FIG. It is an axial perpendicular direction sectional view of a cutting edge. It is the BB sectional view taken on the line of FIG. It is a block diagram which shows the outline of the control system of a broach quality control apparatus and a broach processing apparatus. It is a figure explaining the cutting resistance load which acts on a broach at the time of broach processing. It is the graph which showed the relationship between the amount of flank wear and cutting resistance load. It is a figure which shows the relationship between cutting resistance load and broach movement distance. It is a figure which shows the relationship between cutting resistance load and broach movement distance. It is a figure which shows the other structural example concerning this Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Broach processing apparatus 4 Brooch holding means 4a Ram part 5 Drive means 11 Control means 21 Brooch quality control means (brooch quality control apparatus)
22 Cutting resistance measuring part (Back force measuring means)
23 Broach movement position measurement unit 24 Broach life determination processing unit (brooch life determination means)
25 Cutting edge state determination processing unit (cutting edge state determination means)
26 Time measurement unit 31 Load sensor 32 Movement position sensor 101 Broach 110 Cutting edge 111 Rake face 112 Flank face 113 Edge part s Flank wear amount t Cutting depth h Cutting width

Claims (6)

  Actual measured value of the back resistance force acting on the broach according to the movement in the cutting direction and acting in the direction perpendicular to the axial direction of the broach, and the clearance of the cutting edge of the broach Compared with a reference value which is a back component force when the surface wear amount is a wear limit value, when the measured value is equal to or less than the reference value, it is determined that the life of the broach has not been reached, and the measured value is When the reference value is exceeded, it is determined that the life of the broach is determined. By moving at least one of the broach and the workpiece in the cutting direction of the broach, a cutting resistance load acting on the broach according to the movement in the cutting direction and acting in a direction perpendicular to the axial direction of the broach Back component force measuring means for measuring the back component force,
Compared with the actual value of the back component force actually measured by the back component force measuring means and a reference value that is the back component force when the flank wear amount of the cutting edge of the broach is a wear limit value, Broach life judging means for judging that the life of the broach has not reached when the measured value is less than or equal to the reference value, and for determining the life of the broach when the measured value exceeds the reference value. A brooch quality control device.   Based on the actual measured value of the back component force, the flank wear amount of the cutting edge is estimated, and the reference is a back component force when the flank wear amount of the cutting edge of the broach is the estimated flank wear amount If the measured value is larger than the reference value by a predetermined value or more between the start of movement in the cutting direction of the broach and the end of movement, the value is compared with the measured value. The broach quality control device according to claim 2, further comprising a cutting edge state determining means for determining that the cutting edge to be in an abnormal state.   The reference value is calculated based on a specific cutting resistance load that is a cutting resistance load per unit area of a portion that is cut and removed by the cutting edge of the broach and a removal area that is cut and removed by the cutting edge. The broach quality control device according to claim 2 or 3.   A broaching device comprising control means for performing control for disabling execution of broaching when it is determined by the broach quality control device according to claim 2 or 3 that the life of the broach has been reached. . A broach comprising control means for performing control to disable execution of broaching when the broach quality control device according to claim 3 determines that the cutting edge is in an abnormal state. Processing equipment.

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