JP3117939U - Tapping device - Google Patents

Abstract

Provided is a tapping device that reliably prevents damage to taps and has a simple structure and can be manufactured at low cost.
A control unit 20 that retracts and controls a tap 12 before a limit torque that damages the tap is applied, and the control unit 20 stores a set torque value T for each type of the tap 12 is provided. The spindle rotation motor control unit 26, the input unit (28) for selecting the type of the tap 12, the torque detection unit 30 for detecting the total value of the load torque applied to the spindle rotation motor 13, and the input unit 28. The set torque value T is read from the storage unit 24 corresponding to the type of the tap, and the load setting is determined by comparing the read set torque value and the total load torque value detected by the torque detection unit 30 during rotation of the spindle. And a processing unit 22 including a torque comparison / determination unit that is configured to retract the tap when the total load torque value is equal to or greater than a set torque value.
[Selection] Figure 1

Description

  The present invention relates to a tapping device that prevents breakage of a tap during tapping.

For example, when tapping a workpiece with a tapping machine or the like, the load torque applied to the tap is abruptly increased due to clogging of cutting chips and the tap is often broken. If the tap breaks, the tap is lost unnecessarily, and at the same time, the tip of the folded tap remains on the work, so that the work cannot be used as a product. Therefore, various techniques for preventing tap breakage during tapping have been proposed. For example, Patent Document 1 discloses the technique. In the tapping device described in Patent Document 1, whether or not the wear level of the tapper is a lifetime by sequentially calculating the actual cutting load or the load increase amount from the total load detected at the time of tapping and a preset reference load, or It has an overload judgment means to judge whether or not the tapper is clogged with cutting waste, and it is judged that the tapper is at the end of its life or the tapper is clogged with cutting waste. When this is done, the spindle is decelerated and cutting of the tapper is stopped while the rotation phase of the spindle and the feed position remain synchronized. Further, as the reference load, for example, the total load torque (idle operation reference load torque) at the time of idling is used.
Japanese Patent No. 3650737

  In the tapping device described in Patent Document 1, the actual cutting load torque or the cutting load torque increase amount is sequentially calculated during tapping, and the calculated actual cutting load torque or cutting load torque increase amount and the overload determination value are calculated. Since it is necessary to perform sequential determination (calculation), both the hardware side of the computer of the control unit and the control program are complicated. In particular, in order to prevent breakage of taps rotating at high speed, high-speed arithmetic and control processing is required in the processing device, so that a high-performance processing device and complex electronic circuits are required, and the device manufacturing cost Was expensive. In addition, since the reference load torque during idling is used as the reference load, tapping is performed in idling each time before tapping, and the total load data detected at that time is saved in the computer by input operation on the input device. Therefore, there are problems such as troublesome preparation before the machining operation, complication of the work process, a long working time, and a high processing cost.

  The present invention has been made in view of the above-described conventional problems, and one of its purposes is to reliably prevent the tap from being damaged, and to be simple and inexpensive to manufacture. An object of the present invention is to provide a tapping apparatus that can perform preparation and perform smooth tapping.

  In order to solve the above-mentioned problems, the present invention is a tapping device that rotates a tap 12 connected to a main shaft 14 to make a tap hole, and controls the retraction of the tap 12 before a limit torque that damages the tap is applied. The control unit 20 includes a storage unit 24 that stores a preset torque value T that is less than a preset failure limit torque value for each type of the tap 12, and a spindle that controls the spindle rotating motor 13. The rotary motor control unit 26, an input unit (28) for selecting the type of the tap 12 connected to the main shaft 14, a torque detection unit 30 for detecting the total value of the load torque applied to the main shaft rotary motor 13, and an input unit ( 28) The set torque value T is read from the storage unit 24 corresponding to the type of tap selected in 28), and the read set torque value and the torque detection unit 30 are detected during the spindle rotation. And a processing unit 22 including a torque comparison / determination unit 222 for comparing the load torque total value and determining the load, and when the total load torque value exceeds a set torque value, the tap is retracted and controlled. The tapping device 10 is characterized. The tapping device 10 may be, for example, a vertical device in which the rotation axis of the main shaft is arranged in the vertical vertical direction, or a horizontal device in which the rotation axis of the main shaft is set in the horizontal direction. The tapping device may be a device that manually adjusts the position of the tap with respect to the workpiece, or a device that drives a motor or the like based on a numerical value input to the computer to control the position. . Further, it is preferable that the set torque value stored for each tap type in the storage unit 24 is further subdivided and stored by the material of the workpiece.

  Further, the control unit 20 includes a rotation number detection unit 32 that detects the rotation number of the tap 12, and the storage unit 24 stores a tap processing rotation number R set in advance for each tap type. When the processing unit 22 pierces the tap hole, the processing unit 22 rotates the tap 12 at a constant rotation speed R stored in the storage unit 24 corresponding to the type of tap selected by the input unit (28). It is good to control so that.

  Further, the processing unit 22 does not compare the total load torque value with the set torque value until the main shaft 14 reaches a constant rotation speed after the rotation start of the main shaft 14, or the total load torque value is the set torque value. Even when the above is reached, the retraction control of the tap 12 may not be performed. That is, the processing unit 22 performs control such that the tapping control of the tap 12 is not performed without comparing and determining the total load torque value and the set torque value before the tap actually drills the tap hole. Control is performed so that the tap 12 is not retracted even when the total load torque value is compared with the set torque value and the total load torque value is equal to or greater than the set torque value.

  Further, for each type of tap, the storage unit 24 retracts the tap to a position where the torque load due to drilling is eliminated when the total load torque value becomes equal to or greater than the set torque value T, and the hole being processed again. The life number N before reaching the life limit due to wear or fatigue of the tap at the time of repeating the operation of drilling through the inside is stored, and the processing unit 22 determines the number of repetitions of the advance / retreat control of the tap 12. If the number of times of service life is less than N, the advancing / retracting control of the tap 12 is repeated, and the rotation of the spindle 14 is stopped when the number of times the tapping / retreating control of the tap 12 is repeated N times or more. It is good to do. That is, before reaching the life limit due to the fatigue that the tap accumulates and breaks due to repeated advancement and retraction of the tap, or the tap wears and the tap hole cannot be cut, The rotation of the spindle can be stopped.

  According to the tapping device of the present invention, the tapping device that rotates the tap connected to the main shaft to make the tap hole includes a control unit that controls the retraction of the tap before a limit torque that damages the tap is applied. The control unit is connected to the main shaft, a storage unit that stores a set torque value less than a preset failure limit torque value for each tap type, a main shaft rotation motor control unit that controls the main shaft rotation motor, and the main shaft. An input unit for selecting the tap type, a torque detection unit for detecting the total value of the load torque applied to the spindle motor, and a set torque value read from the storage unit corresponding to the tap type selected by the input unit A processing unit including a torque comparison determination unit that determines a load by comparing the set torque value read during rotation of the spindle and the total load torque value detected by the torque detection unit, Since the tap is retracted when the total torque value exceeds the set torque value, it is possible to reliably prevent the tap from being subjected to a load that damages the tap, thereby protecting the tap from bending and workpieces. However, a tapping device capable of drilling a tapped hole can be realized with a simple configuration, and can be manufactured at low cost. In particular, the value used for determining the load torque applied to the tap is only a comparison operation based on the binary value of the load torque total value that is sequentially detected and a preset torque value that is set in advance. It can be configured relatively simply. Also, before tapping, simply selecting the type of tap connected to the spindle at the input section, etc., the set torque value is set according to the tap, so only a simple preparatory work is required. Can be processed.

  Further, the control unit has a rotation number detection unit that detects the rotation number of the tap, and the storage unit stores a preset processing rotation number for each tap type, and the processing unit includes: When making a tap hole, for example, by controlling the tap to rotate at a constant processing rotation speed stored in the storage unit corresponding to the type of tap selected in the input unit, for example, Depending on the type and material of the workpiece, the tap hole can be drilled while preventing breakage of the tap while maintaining a suitable processing speed condition. As a result, a highly accurate and high quality tap hole is drilled. it can.

  In addition, the processing unit does not compare the total load torque value with the set torque value or until the total load torque value is equal to or greater than the set torque value from when the main shaft starts rotating until before the main shaft reaches a constant rotational speed. Even if the main shaft is not retracted, the tap is actually placed in the tap hole without complicating the configuration, for example, due to the high total load torque that is instantaneously applied when the main shaft starts rotating. It is possible to prevent an operation failure such that the tap is retracted before the advance.

  In addition, for each type of tap, the storage unit retracts the tap to a position where the torque load due to drilling is eliminated when the total load torque value is equal to or greater than the set torque value, and again in the hole being processed. Store the number of times of life before reaching the life limit due to wear or fatigue of the tap when repeating the operation to advance and drill holes, and the processing unit is less than the number of times of life of the tap advance / retreat control, The tap is repeatedly controlled by repeating the tap advance / retract control and controlling the spindle to stop rotating when the tap advance / retract control repeat count exceeds the lifespan. The tap that gradually accumulates fatigue due to the advancement / retraction control of the tap does not break due to the fatigue life, or the tap that gradually wears cannot be drilled due to the wear life. Before and rotation of the spindle is stopped, it can be prevented breakage due life of the tap, it is possible to prevent damage to the workpiece.

  Hereinafter, a tapping apparatus of the present invention will be described with reference to the accompanying drawings. The tapping device of the present invention is a tapping device that prevents damage to the tap caused by an overload applied to the tap due to clogging of cutting chips during tapping. 1 to 5 show an embodiment of a tapping apparatus according to the present invention. In the present embodiment, as shown in FIG. 1, the tapping device 10 includes a control unit 20 that controls the retraction of the tap before a limit torque that damages the tap is applied when the tap hole is processed.

  In this embodiment, as shown in FIGS. 1 and 2, for example, the tapping device 10 includes a main shaft 14 that is rotatably provided with a tap 12 connected to a shaft tip, and a workpiece (working object) on a horizontal plane. It has a processing table 16 on which W is placed, a head stock device 18 that rotatably supports the main shaft 14, and a main shaft rotating motor 13 that rotates the main shaft 14. In the present embodiment, the rotation axis of the main shaft 14 is set in the horizontal horizontal direction, and the tap is provided to rotate around the horizontal axis. In the present embodiment, the Z-axis is set in the axial direction of the tap, the X-axis is set in the horizontal direction perpendicular to the Z-axis, and the Y-axis is set in the vertical direction. The headstock device 18 is movable in the X-axis direction and the Y-axis direction with respect to the work table 16, and the head stock device 18 is moved so that the tap is positioned with respect to the pilot hole of the workpiece W on the worktable. The Further, the tapping device 10 has an X-axis feed motor 19 that moves the headstock device in the X-axis direction, and the X-axis direction of the workpiece W on the work table 16 of the tap 12 via the X-axis feed motor. Positioning is performed. The headstock device 18 is moved in the Y-axis direction by, for example, manually moving up and down via a handle (not shown) to position the tap 12 with respect to the workpiece in the Y-axis direction. The movement of the tap 12 in the Z-axis direction, that is, the advancement of the tap 12 into the pilot hole of the work W is manually moved via the handle 15, for example. When the rotating tap 12 is advanced into the pilot hole, the tap 12 is rotated by itself while cutting the tap hole by the rotation of the tap itself. A fixing device (not shown) is provided on the processing table 16, and the workpiece W placed on the processing table is fixed at an arbitrary position.

  Further, the tapping device 10 includes an X-axis coordinate detector 171 that detects the X-axis position of the tap, a Y-axis coordinate detector 172 that detects the Y-axis position, and a Z-axis coordinate detector 173. Each of the X, Y, Z coordinate detectors 171, 172, and 173 is electrically connected to the control unit 20, detects the position sequentially, and sends detection data to the control unit 20. An operation unit 21 including an on / off switch and an input / display device is provided on the upper side of the headstock device.

  In the present embodiment, as shown in FIG. 1, the control unit 20 includes a processing device 22, a storage device 24, a spindle rotation motor control device 26, an input / display device 28, a torque detection unit 30, and a rotation speed. And a detection unit 32. The control unit 20 numerically controls the tapping device 10 based on the detected load torque, the numerical value such as the rotation speed, the numerical value stored in the storage unit, and the numerical value of the calculation result by the control program. The control unit 20 includes, for example, a computer or the like built in the headstock device 18 or the machining table 16.

  As shown in FIG. 3, in the present embodiment, for example, a set torque value T less than the breakage limit torque value set in advance for each type of the tap 12 is stored in the storage device 24. The storage device 24 stores a processing rotation speed R that is set in advance for each type of the tap 12. The machining rotation speed R is set to an optimum rotation speed that can be machined with high accuracy without breaking the tap when the tap hole is machined. Further, the storage device 24 stores the number N of lifetimes described later. In the present embodiment, each type of tap is further subdivided according to the material of the workpiece and stored in a database. That is, the database constructed in the storage device 24 includes, for example, tap types (for example, M2.5, M3, M4,...) Classified by tap diameter, pitch, etc., and workpiece materials ( For example, a set torque value T, a processing rotation speed R, a service life number N, and the like are stored in association with aluminum, copper, brass, iron, stainless steel, plastic, and the like. In addition, the storage device 24 has a memory unit 242 that temporarily stores and holds a set torque value T, a processing rotation speed R, and the like corresponding to the selected tap type and workpiece material. Further, in the present embodiment, the storage device 24 stores a control program, the position of the pilot hole of the workpiece, the depth of the tap hole to be drilled, other processing conditions, and the like. Read out.

  In the present embodiment, the input / display device 28 includes, for example, a touch panel in which an input unit and a display unit are integrated, and configures the operation unit 21 of the headstock device 18. The input / display device 28 displays the tap type and workpiece material stored in the storage unit 24, and allows selection of the tap type and workpiece material. Further, the input / display device 28 displays the X, Y, Z axis coordinate position of the tap based on the detection data from the X, Y, Z coordinate detection unit, for example, and can perform the tap positioning while viewing the display. It is like that. Further, the input / storage device 28 can input the position of the tap hole, the depth of the tap hole, other processing conditions, and the like according to the workpiece and store them in the storage unit 24. Note that the input device and the display device may be configured separately.

  The torque detection unit 30 is a detection unit that detects the total value of the load torque applied to the spindle rotating motor. In the present embodiment, the torque detection unit 30 sequentially detects, for example, the current value when rotating the spindle motor as the total load torque value. That is, the torque detector sequentially detects changes in the current value of the spindle motor and outputs the current value to the processing device 22 side. The total load torque value detected by the torque detector 30 includes torque due to inertia for rotating the spindle, tap, motor, etc., load torque received from the workpiece when the tap cuts the tap hole, and cutting waste clogged in the tap. It is a value that includes all the load torque that is applied at the time. The torque detection unit 30 is connected to the spindle rotation motor control device 26, and the detected value is output to the processing device 22 via the spindle rotation motor control device 26. On the other hand, the rotation speed detection unit 32 includes a rotation sensor that sequentially detects the rotation speed of the main shaft 14. In the present embodiment, the rotation speed detection unit 32 is connected to the main shaft rotation motor control device 26, and the detection data is output to the processing unit 22.

  The spindle rotation motor control device 26 is electrically connected to the spindle rotation motor 13 and performs motor drive control including forward rotation, reverse rotation, and stop of the spindle rotation motor 13 in accordance with a signal from the processing device 22. It is a motor control device. In the present embodiment, the spindle rotation motor control device 26 sequentially receives detection data from the torque detection unit 30 and the rotation speed detection unit 32 and outputs the detection data to the processing device 22. A control signal is output to the spindle rotating motor 13 based on the calculation and determination results.

  The processing device 22 executes the control program stored in the storage device in the control unit, receives data from the storage device 24, the spindle motor control device 26, the input / display device 28, the detection unit, etc., and performs calculation and processing. It is the central part that controls each device. In the present embodiment, the processing device 22 sequentially compares and determines whether or not the total load torque value applied to the main shaft rotating motor 13 from the torque detector 30 exceeds the set torque value. When determining that the total load torque value is lower than the set torque value, the spindle rotation motor control device 26 is controlled so as to rotate the spindle 14 at a constant rotation speed, so that a tapped hole is drilled. On the other hand, when the processing device 22 determines that the load torque is equal to or greater than the set torque value, the spindle rotating motor control device is controlled so as to control the withdrawal of the tap.

  Specifically, in the present embodiment, as illustrated in FIG. 3, the processing device 22 includes a torque comparison determination unit 222 and a rotation speed comparison determination unit 224. When the type of tap and the material of the workpiece are selected by the input / display device 28, the processing device 22 sets the set torque value T stored in the storage device 24 corresponding to the selected tap type and workpiece material. Then, the processing rotation speed R and the like are stored and held in the memory unit 242 of the storage device 24. While the spindle is rotating, the processing device 22 reads the set torque value T stored and held in the area of the storage unit via the torque comparison determination unit 222, and uses the read set torque value T and the torque detection unit 30. The load is determined by sequentially comparing the detected total load torque value.

  As shown in FIG. 5, when the torque comparison determination unit 222 determines that the total load torque value is smaller than the set torque value T, the processing device 22 passes through the rotation number comparison unit 224 as described later. The spindle rotating motor control device is feedback-controlled so that the spindle rotates at a constant rotation speed R (BC section). On the other hand, when the torque comparison / determination unit 222 determines that the total load torque value is equal to or greater than the set torque value (point C), the processing device 22 determines that the tap is overloaded, and the spindle rotation motor. The controller 26 is controlled to perform tap evacuation control (CG section). The specific retraction control in the present embodiment is, for example, that the processing device 22 activates the spindle motor controller before the breakage limit torque value at which the tap breaks is applied when the total load torque value reaches the set torque value. The spindle 14 is suddenly decelerated and stopped (CD section). After the instantaneous stop (DE interval), the rotation direction of the main shaft 14 is switched to gently accelerate the reverse rotation of the main shaft 14 (EF interval), and torque generated due to clogging of chips during machining at a constant reverse rotation speed. The tap is withdrawn from the tap hole until the load disappears (FG section). After the tap is retracted from the tap hole, a large braking force is applied and the reverse rotation of the main shaft 14 is rapidly decelerated and stopped (GH section). Note that the rotational speed for rotating the main shaft in the reverse direction is set relatively gently so that the tap does not break. After the tap is retracted, the processing device 22 again rotates the main shaft in the forward direction to advance the tap into the hole being machined and resume drilling. In this way, the processing device 22 advances the tap and pierces the tap hole while repeating the retraction control. As described above, in this embodiment, the value used for determining the load torque applied to the tap is only a comparison operation based on the binary value of the load torque total value that is sequentially detected and a preset torque value that is set in advance. The circuit configuration, control program, and the like may be relatively simple, and a tapping device that can reliably prevent tap breakage can be easily configured and manufactured at low cost.

  For example, the processing device 22 is configured to compare and determine whether or not the tap hole has been drilled to a preset tap hole depth stored in the storage unit 24. In the present embodiment, the processing device 22 detects the Z-axis coordinate position of the tap detected by the Z-axis coordinate detection unit 171 as the depth of the tap hole that the tap has actually drilled, and the depth of the tap hole, The spindle rotation motor control device is controlled by comparing with a preset value. When it is determined that the depth of the tap hole is smaller than the preset depth value, the processing device 22 repeats tap advancement / retraction control, and the tap hole depth is set to the depth value. When it is determined that the spindle has reached, the spindle is controlled to stop.

  Further, when drilling the tap hole, the processing device 22 reads the processing rotation number R stored and held in the area of the storage unit 24 via the rotation number comparison / determination unit 224, and reads the processing rotation thus read. The number and the number of rotations detected by the rotation number detection unit 32 are sequentially compared and determined. As shown in FIG. 5, the processing device 22 accelerates the spindle until it rotates at the machining rotational speed R (AB section), and feedback-controls the spindle motor control device so as to maintain a constant machining rotational speed R. (BC section). Specifically, as shown in the BC section of FIG. 5, the processing device 22 receives resistance from the workpiece when the tap hole is drilled while rotating the spindle at the machining rotational speed R. If the rotation speed of the main shaft is to be reduced, the current of the main shaft rotation motor is increased and the rotation speed of the main shaft is held at the machining rotation speed R. Conversely, if the rotational speed is to be increased, the current of the spindle motor is decreased, and the rotational speed of the spindle is maintained at the machining rotational speed R. Thus, since the main shaft, that is, the number of tap rotations is kept constant, the tap hole can be drilled with high precision and cleanness.

  In the present embodiment, the processing unit 22 is configured not to perform tap retraction control until the rotation speed reaches a constant value after the spindle starts rotating. When starting the rotation of the main shaft, a large load torque is required instantaneously (or for a certain period of time) to rotate the stopped main shaft, tap, and motor rotor, and the total load torque value due to this inertia is the set torque value. May be exceeded. Further, since the torque increases when the rotational speed of the main shaft is low, the total load torque value detected before reaching the predetermined processing rotational speed R may exceed the set torque value. Thus, before the main shaft reaches the processing rotation speed, that is, before the tap is actually advanced into the tap hole, the total load torque value of the main shaft rotation motor becomes equal to or greater than the set torque value, and tap retraction control is performed. Malfunction occurs. Therefore, for example, in the interval between accelerations until the rotational speed of the spindle reaches a constant processing rotational speed R (AB section in FIG. 5), the tapping holes are not actually drilled. The torque comparison / determination unit 222 does not perform comparison / determination between the total load torque value and the set torque value, and does not perform tap retraction control. That is, the processing device 22 is more likely to break the tap, and the comparison and determination of the load torque total value is performed only when the tap has actually advanced into the tap hole and drilled (BC section in FIG. 5). In addition, tap evacuation control is performed. As a result, it is possible to reliably prevent malfunctions of the tapping device as described above without complicating the configuration or increasing the calculation speed. Note that the processing device 22 may make the load torque total value and the set torque value be compared and determined from when the rotation of the main spindle starts to reach a constant rotational speed. Even when the total load torque value is equal to or greater than the set torque value, the tap withdrawal control may not be performed.

  Further, as shown in FIG. 3, the processing device 22 counts the number of repetitions of tap advance / retreat control, the number of repetitions detected by the counting unit 226, and the lifetime stored in the storage device in advance. A number comparison unit 228 that compares the number N. As for the number of times of life N, taps that are repeatedly advanced and retracted as described above gradually accumulate fatigue as they advance into the tap hole of the workpiece and drill holes, and finally the tap breaks with the life due to fatigue. However, it is set to the number of times before the life of such a tap becomes the limit. The number N of times of life is stored in the storage device 22 together with the set torque value and the processing rotation speed, corresponding to the type of tap and the material of the workpiece, for example. When the type of tap and the material of the work are selected by the input / display device 28, the processing device 22 reads the life number N corresponding to the selected tap type and the material of the work, and tap evacuation control is performed. The number comparison unit 228 compares and determines the number of times from the counting unit 226 and the life number N every time. Then, when the number comparison unit 228 of the processing unit 22 determines that the number of repetitions of tap advancement / retraction control is less than the lifespan number, the spindle rotation is performed so as to repeat the tap advancement / retraction control as described above. A control signal is sent to the motor control device 26. On the other hand, if it is determined that the number of tap advancement / retraction control repetitions is N or more, the tap is retracted from the tap hole being processed, and the spindle re-enters the tap hole to rotate the spindle. Control to stop. Thereby, it is possible to prevent the tap from being broken and remaining on the workpiece W due to fatigue, and the workpiece can be protected. In the present embodiment, the number of times of life is set based on the fatigue life in which the tap breaks due to fatigue accumulated in the tap, but the wear life in which the tap hole cannot be drilled due to wear of the tap. It is good also as setting to the frequency | count before becoming.

  As shown in FIG. 1, the control unit 20 has an X-axis feed motor control device 29 that drives and controls the X-axis feed motor 19. The X-axis feed motor control device 29 receives, for example, a control signal from the processing device 2 based on detection data from the X-axis coordinate detection unit 171 and a control program, and drives and controls the X-axis feed motor to control the spindle head device 18. Is moved in the X-axis direction. For example, by previously inputting the positions of a plurality of pilot holes provided in the workpiece, it is possible to automatically perform a continuous tap hole drilling operation.

  FIG. 4 shows a schematic flowchart when the tap hole is drilled, and will be described together with the operation of the tapping apparatus according to the present embodiment. For example, as shown in FIG. 1, a workpiece W having a pilot hole drilled in advance at a position where a tap hole is drilled is placed on the processing table 16 and fixed by a fixing device (not shown) or the like. As shown in FIG. 4, in step S12, first, the tap 12 is connected to the main shaft 14 and attached to the tapping device. At this time, the headstock device is moved via a handle (not shown), an operation unit, or the like, and the tap is positioned at a position corresponding to the prepared hole of the workpiece. If necessary, the load torque in a state where no load is applied to the tap may be detected to adjust whether or not the load torque value is within a predetermined range. Proceeding to step S14, the kind of tap connected to the spindle and the material of the work are selected via the input / display device. Then, in step S16, when a tap type or the like is selected, processing conditions such as a set torque value, a processing rotation speed, and a life count are read by the processing unit. At this time, for example, other processing conditions such as the coordinate position of the pilot hole of the workpiece and the depth of the tap hole are input via an input / display device as necessary. Next, the process proceeds to step S18, where the spindle is rotated at a constant machining rotational speed, and the tap 12 is advanced into the pilot hole of the workpiece W via the handle 15, for example, to perform tap machining. In step S20, the total value of load torque applied to the spindle rotating motor is sequentially detected via the torque detector while the spindle is held at the set machining rotational speed. In step S22, a torque comparison determination is made as to whether or not the total load torque value is equal to or greater than the set torque value. If it is determined that the total load torque value is lower than the set torque value (in the case of No), the process proceeds to step S24, and it is determined whether the tap hole is drilled to the set cutting depth. If the depth of the tap hole drilled in step S24 has reached the set value (in the case of Yes), the process proceeds to step S26 and the spindle is stopped. In step S28, the main shaft is reversely rotated to retract the tap from the tap hole, and the tapping process is completed. On the other hand, when it is determined in step S24 that the depth of the drilled tap hole has not reached the set value (in the case of Yes), the process returns to step S20.

  On the other hand, in step S22, if the tap is clogged with cutting waste and the total load torque value increases in order to maintain the rotation speed of the spindle motor, and the total load torque value is equal to or greater than the set torque value (in the case of Yes). Then, it is determined that an overload is applied to the tap, and as shown in the CD section of FIG. 5, the process proceeds to step S <b> 32, and the processing apparatus rapidly decelerates the spindle to stop it. In step S34, it is compared and determined whether or not the number of tap advance / retreat control repetitions is equal to or greater than a preset life setting N. If it is determined that the number of tap advance / retreat control repetitions is less than the number of lifetimes (in the case of No), the process proceeds to step S36, and the main shaft is rotated in reverse as shown in the EG section of FIG. Thus, the tap is retracted to a position where the torque load due to drilling is eliminated (to a position where the total load torque value during the drilling of tap holes is less than the set torque value T). After the tap is reversely rotated and retracted, the process proceeds to step S38 and the spindle is rapidly decelerated and stopped. In step S40, the main shaft is rotated again, the process returns to step S20, and the tap is re-advanced into the tap hole while monitoring the total load torque value to process the tap hole. Thereby, smooth tapping of the tapped holes can be performed while preventing tapping well. On the other hand, if it is determined in step S34 that the number of tap advance / retreat control repetitions has reached the number of lifespan (in the case of Yes), the process proceeds to step S42, and the main shaft is rotated backward to tap the tap. After retracting, the spindle is stopped in step S44. Then, after replacing the tap with a new one in step S46, the process returns to step S18 to resume the drilling of the tap hole. Thereby, it is possible to prevent breakage due to the life of the tap.

  The tapping apparatus of the present invention described above is not limited to the configuration of only the above-described embodiment, and may be arbitrarily modified without departing from the essence of the present invention described in the claims of the utility model registration. Also good.

  The tapping device of the present invention is, for example, a vertical device in which the rotation axis of the main shaft is arranged in the vertical vertical direction, a horizontal device in which the rotation axis of the main shaft is set in the horizontal direction, or a manual or automatic tapping device. The present invention is applied to various tapping device configurations such as those capable of position control.

It is a schematic block diagram of a tapping apparatus according to the present embodiment. It is a schematic perspective view of the tapping apparatus of FIG. It is a schematic explanatory drawing which shows a part of control part of the tapping apparatus of FIG. It is a schematic flowchart figure at the time of drilling a tap hole with the tapping apparatus of FIG. It is a graph which shows roughly the time change of the rotation speed of the spindle motor controlled by the processing unit of FIG. 1 and the time change of the total load torque value.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Tapping device 12 Tap 13 Spindle rotation motor 14 Spindle 20 Control part 22 Processing apparatus 222 Torque comparison determination part 224 Rotation speed comparison determination part 24 Memory | storage device 26 Spindle rotation motor control apparatus 28 Input / display apparatus 30 Torque detection part 32 Rotation number detection Part

Claims (4)

A tapping device for drilling a tap hole by rotating a tap connected to a main shaft,
Including a control unit that retracts the tap before the limit torque that damages the tap is applied,
The control unit
A storage unit that stores a set torque value less than a preset breakage limit torque value for each tap type;
A spindle rotation motor control unit for controlling the spindle rotation motor;
An input unit for selecting the type of tap connected to the spindle;
A torque detector for detecting the total load torque applied to the spindle motor;
Read the set torque value from the storage unit corresponding to the type of tap selected by the input unit, and compare the read set torque value during spindle rotation with the total load torque value detected by the torque detection unit And a processing unit including a torque comparison / determination unit for determining a load, wherein the tap is retracted when the total load torque value is equal to or greater than a set torque value. The control unit has a rotation number detection unit that detects the rotation number of the tap,
In the storage unit, the processing rotation number of the tap set in advance for each tap type is stored,
The processing unit is configured to control the tap so that the tap is constantly rotated at the processing rotation number stored in the storage unit corresponding to the type of the tap selected by the input unit when the tap hole is drilled. The tapping apparatus according to claim 1.   The processing unit does not compare the load torque total value with the set torque value or until the load torque total value is greater than or equal to the set torque value from when the spindle starts rotating until before the spindle reaches a certain number of revolutions. However, the tapping device according to claim 1 or 2, wherein tap evacuation control is not performed. For each type of tap, when the total load torque value is equal to or greater than the set torque value, the storage unit retracts the tap to a position where there is no torque load due to drilling, and advances through the hole being processed again. Store the number of times of life before reaching the life limit due to wear or fatigue of the tap when repeating the drilling process,
The processing unit repeats the tap advancement / retraction control when the tap advancement / retraction control repeat count is less than the lifetime number,
The tapping device according to any one of claims 1 to 3, wherein control is performed to stop the rotation of the main spindle when the number of tap advance / retreat control repetitions exceeds the number of lifetimes.

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