JP2006088299A - Tapping device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tapping device capable of stabilizing screw machining precision against a work by monitoring a tap holding means. <P>SOLUTION: Forward moving time Tf until the time to receive input of a forwarding end detection signal from a limit switch 76 for forwarding end detection from the time to output a normally rotating direction rotating driving signal is measured against a geared motor 51 to move a tap shaft 41 which is the tap holding means in the tap forwarding direction and the tap retreating direction by rotating it in the normally rotating direction and the reversing direction, and it is compared with previously set forward moving standard time (Tfmin to Tfmax). Thereafter, output of the normally rotating direction rotating driving signal and a reversal direction rotating driving signal to the geared motor 51 is prohibited by judging that abnormality occurs on a tap unit 5 when the forward moving time is longer than the forward moving standard time. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a tapping device that forms a screw hole by screwing a tap into a screw pilot hole previously formed in a workpiece.

  Conventionally, there is a tapping device that forms a screw hole in a workpiece such as an engine block of an automobile.

  A conventional tapping device has a workpiece holding means for holding a workpiece in a preset posture, a feed unit that moves in a direction approaching and separating from the workpiece held by the workpiece holding means, and a rotation to the feed unit. A tap shaft that is a tap holding means that is freely supported and movable along the rotation axis direction, a socket that is provided at the tip of the tap shaft and supports the tap detachably on the same axis, and a tap on the tap shaft A geared motor that rotates in the forward rotation direction that is the threading rotation direction and the reverse rotation direction that is the tap removal rotation direction, and the tap shaft in the tap forward direction and tap backward direction according to the rotation of the tap shaft in the forward rotation direction and reverse rotation direction. A feed screw mechanism for feeding and moving is provided.

  The geared motor includes a brake, and when not energized, the brake shoe is pressed against the motor rotation shaft so as not to rotate, and when energized, the brake is released and the motor rotation shaft can be rotated. ing. The feed screw mechanism has a shaft portion in which a master screw is screwed and a boss portion in which a master screw hole into which the master screw of the shaft portion is screwed is formed, and has the same pitch as the screw pitch of the tap. The tap shaft is configured to move in the tap forward direction and the tap backward direction.

  The feed unit is provided with a forward end detecting limit switch for detecting the forward end of the tap shaft and a backward end detecting limit switch for detecting the backward end, and the forward end provided in advance on the tap shaft. The forward end of the tap shaft is detected by the detection dog abutting on the switch lever of the forward end detection limit switch at the forward end, and the backward end detection dog provided in advance on the tap shaft is also the backward end at the backward end. The retracted end of the tap shaft is detected by contacting the switch lever of the detection limit switch.

  Control of the tapping apparatus having the above configuration is performed by a control unit. When the control unit inputs a tapping start command by operating the start button or the like, the control unit moves the feed unit in the workpiece approaching direction and stops it at a position where the separation distance between the tip of the tap and the screw hole of the workpiece is about 5 mm.

  Then, a forward rotation direction rotation drive signal is output to the geared motor, the geared motor is rotated forward, the tap shaft is rotated in the forward rotation direction, and the feed screw mechanism moves the tap forward direction at the same pitch as the tap screw pitch. .

  Then, the tap is screwed into the screw pilot hole, the screw pilot hole is threaded to a predetermined depth, the forward end detection dog abuts against the switch lever of the forward end detection limit switch, and the forward end detection limit switch is tapped. When the forward end of the shaft is detected, the output of the forward rotation direction drive signal to the geared motor is stopped, the brake is applied by de-energization to stop the rotation of the geared motor, and the tap shaft is stopped at the forward end.

  Then, a reverse rotation direction drive signal is output to the geared motor, the brake is released by energization, the tap shaft is rotated in the reverse direction and moved in the tap backward direction, and the tap is extracted from the screw hole formed in the workpiece.

  When the tap shaft is retracted to a predetermined position, the backward end detection dog abuts the switch lever of the backward end detection limit switch, and when the backward end detection limit switch detects the backward end of the tap shaft, The output of the reverse direction rotation drive signal is stopped, the brake is applied by de-energizing, the rotation of the geared motor is stopped, and the tap shaft is stopped at the backward end.

  According to the conventional tapping device having the above configuration, the tap shaft can be rotated in the forward direction and the reverse direction to be reciprocated between the forward end and the backward end in the tap forward direction and the tap backward direction. A screw hole having a predetermined depth can be formed in the pilot hole. In particular, a geared motor with a brake is used, and the rotation of the geared motor is stopped by detecting the forward end and the backward end, so that it is possible to secure a high degree of stop position accuracy of the tap shaft and to process the screw hole for the workpiece. The accuracy can be stabilized.

  A detection body is attached to the holding body that holds the tap, a sensor that detects the detection body is positioned oppositely, and when the detection body is detected by the sensor, the power supply to the motor is stopped and the holding body is rotated by a predetermined amount. A tapping machine having a configuration for stopping at a stop position has been conventionally proposed and known (for example, see Patent Document 1).

JP-A-6-335823

  However, in the case of the conventional tapping device having the above-described configuration, the forward end and the backward end of the tap shaft are detected only by the forward end detection limit switch and the backward end detection limit switch. In other methods, the detection is performed. Not.

  Therefore, for example, when a malfunction occurs in the forward end detection limit switch and the forward end of the tap shaft cannot be detected, the control unit continues to output the forward rotation direction rotation drive signal to the geared motor. As a result, the tip of the tap may bottom the bottom surface of the screw pilot hole to cause tap breakage, or the shaft portion of the feed screw mechanism may come off from the boss portion.

  Similarly, when the malfunction of the limit switch for detecting the backward end occurs and the backward end of the tap shaft cannot be detected, the control unit continues to output the reverse direction rotation drive signal to the geared motor. As a result, there is a possibility that the tap shaft moves beyond the preset range and moves in the tap retraction direction, and the shaft portion of the feed screw mechanism bites into the boss portion.

  As countermeasures against such problems with the forward end detection limit switch and the backward end detection limit switch, the emergency position is set to the forward side position with respect to the forward end detection limit switch and the reverse side position with respect to the backward end detection limit switch. If a limit switch for stopping is additionally provided and the limit switch for detecting the forward end or the limit switch for detecting the backward end does not operate due to some malfunction, these limit switches for emergency stop are set to the forward end detecting dog or the backward end. A method of stopping the rotational drive of the geared motor by pressing with the detection dog can be considered.

  However, if a failure has occurred in the emergency stop limit switch, the forward end detection dog and the backward end detection dog cannot be detected in the same manner, and the rotation of the geared motor cannot be stopped. Further, the number of limit switches is doubled, and the control becomes complicated due to the increase in the number of contacts in the control unit, and the cost is increased due to the increase in the number of parts.

  Further, in the case of the tapping device having the above configuration, it is possible to detect whether or not the tap shaft has reached the forward end or the backward end, but it is possible to detect a change in the stop position of the tap shaft or a change in the machining time. I can't.

  For example, the sensitivity of the forward end detection limit switch and the backward end detection limit switch is lowered, the position of the forward end detection dog or the backward end detection dog is misaligned, the wear of the brake shoe of the geared motor, and the brake shoe dragging due to poor brake release. If this occurs, the tap shaft cannot be accurately stopped at the forward end and the backward end, the tap shaft stop position changes, the screw hole processing accuracy is impaired, and the processing time changes. There is a problem of end.

  The present invention has been made to solve at least one of the above problems, and an object of the present invention is to provide a tapping device that can monitor the tap holding means and stabilize the screw machining accuracy for the workpiece. .

  The invention of the tapping device according to claim 1, which solves the above-mentioned problem, includes a tap holding means for holding a tap, and supports the tap holding means so as to be rotatable coaxially with the rotation center axis, and taps along the rotation center axis. Support means for movably supporting in the forward direction and tap retreat direction, rotation drive means for rotating the tap holding means rotatably supported by the support means in the forward rotation direction and the reverse rotation direction, and tap holding means by the rotation drive means Feed moving means for moving the tap holding means in the forward direction of the tap in accordance with the rotation of the tap holding means in the forward direction, and for moving the tap holding means in the backward direction of the tap in accordance with the rotation of the tap holding means in the reverse direction by the rotation driving means. And a forward end detection signal that outputs a forward end detection signal by contacting the tap holding means that moves in the tap forward direction by the feed moving means. And a backward end detecting means for outputting a backward end detection signal by contacting with the tap holding means that moves in the tap backward direction by the feed moving means, and forward rotation direction rotation drive to the rotational drive means based on a predetermined tapping start command Outputs a signal, rotates the tap holding means in the forward rotation direction to move in the tap forward direction, and receives the forward end detection signal from the forward end detection means to output the reverse direction rotation drive signal to the rotation drive means. Then, the tap holding means is rotated in the reverse direction to move in the tap backward direction, and when the backward end detection signal is input from the backward end detection means, a rotation stop signal is output to the rotation driving means to rotate the tap holding means. In the tapping device having the control means for stopping, the control means detects the forward end from the time when the forward rotation direction rotation drive signal is output to the rotation drive means. When the forward movement time until the forward end detection signal is received from the means is longer than the preset forward movement reference time, it is determined that an abnormality has occurred, and the forward direction rotational drive signal for the rotational drive means and The output of the reverse direction rotation drive signal is prohibited.

  According to a second aspect of the present invention, in the tapping device according to the first aspect, the control means receives the forward end detection signal from the forward end detection means from when the forward rotation direction rotational drive signal is output to the rotational drive means. When the forward movement time until the time of receipt is shorter than the preset forward movement reference time, it is determined that an abnormality has occurred and the output of the forward rotation direction rotation drive signal and the reverse rotation direction rotation drive signal to the rotation drive means is prohibited. It is characterized by that.

  According to a third aspect of the present invention, in the tapping device according to the first or second aspect, the control unit starts measuring the forward movement time from the time when the forward rotation direction rotation drive signal is output to the rotation drive unit, and the forward movement If the movement time becomes longer than the forward movement reference time before receiving the forward end detection signal from the forward end detection means, a rotation stop signal is output to the rotation drive means and an abnormality is determined to occur. The output of the forward rotation direction rotation drive signal and the reverse rotation direction rotation drive signal to the drive means is prohibited.

  According to a fourth aspect of the present invention, in the tapping device according to any one of the first to third aspects, the control means moves backward from the reverse end detection means from the time when the reverse rotation direction rotation drive signal is output to the rotation drive means. When the reverse movement time until the end detection signal is input is shorter than the preset reverse movement reference time, it is determined that an abnormality has occurred and the forward rotation direction rotation drive signal and the reverse rotation direction rotation drive are detected. The output of the signal is prohibited.

  According to a fifth aspect of the present invention, in the tapping device according to the fourth aspect, the control means receives an input of the backward end detection signal from the backward end detection means from when the reverse rotation direction rotational drive signal is output to the rotational drive means. When the reverse movement time until the time is shorter than the preset reverse movement reference time, it is determined that an abnormality has occurred and the output of the forward direction rotation drive signal and the reverse direction rotation drive signal to the rotation drive means is prohibited. It is characterized by that.

  According to a sixth aspect of the present invention, in the tapping device according to the fourth or fifth aspect, the control means starts measuring the backward movement time from the time when the reverse rotation direction rotational drive signal is output to the rotational drive means, and the backward movement is performed. If the time is longer than the reverse movement reference time before the reverse end detection signal is input from the reverse end detection means, a rotation stop signal is output to the rotation drive means, and it is determined that an abnormality has occurred and is driven to rotate. The output of the forward rotation direction rotation drive signal and the reverse rotation direction rotation drive signal to the means is prohibited.

  According to the invention of the tapping device described in claim 1, it is possible to monitor whether or not the forward movement time until the tap holding means reaches the forward end is longer than the forward movement reference time. If it is longer, it can be determined as abnormal.

  Therefore, it is possible to recognize that some abnormality has occurred, such as a shift in the detection position by the forward end detection means, a shift in the rotation stop position by the rotation drive means, or a change in the rotation speed. Therefore, it is possible to prevent defects such as tap breakage and to form a screw hole whose processing accuracy is always constant.

  According to the invention described in claim 2, it is possible to monitor whether or not the forward movement time until the tap holding means reaches the forward end is shorter than the forward movement reference time, and is shorter than the forward movement reference time. Sometimes it can be judged abnormal.

  Therefore, it is possible to recognize that some abnormality has occurred, such as a shift in the detection position by the forward end detection means, a shift in the rotation stop position by the rotation drive means, or a change in the rotation speed. Therefore, it is possible to prevent problems such as defective molding of screw holes, and to form screw holes with a constant machining accuracy.

  According to the third aspect of the invention, the forward movement time of the tap holding means that moves in the tap forward direction from when the forward rotation direction rotation drive signal is output to the rotation drive means is monitored, and the forward movement time is monitored. If the forward end detection signal is not received from the forward end detection means before the forward movement reference time becomes longer, the rotation of the rotation drive means can be stopped. Therefore, for example, even when the arrival of the tap holding means to the forward end cannot be detected due to a detection failure of the forward end detecting means, the rotational drive of the rotational drive means can be stopped. Therefore, it is possible to prevent the tap tip from hitting the bottom of the screw pilot hole and causing the tap to be bent or the feed moving means to be defective.

  According to the invention described in claim 4, it is possible to monitor whether or not the backward movement time until the tap holding means reaches the backward end is longer than the backward movement reference time, and is longer than the backward movement reference time. Sometimes it can be judged abnormal.

  Accordingly, it is possible to recognize that some abnormality has occurred, such as a shift in the detection position by the backward end detection means, a shift in the rotation stop position by the rotation drive means, or a change in the rotation speed. Therefore, it is possible to prevent an abnormal operation such as moving the tap holding means larger than a preset feed movement amount, and prevent a malfunction in the feed movement means.

  According to the fifth aspect of the present invention, it is possible to monitor whether or not the backward movement time until the tap holding means reaches the backward end is shorter than the backward movement reference time, and is shorter than the backward movement reference time. Sometimes it can be judged abnormal.

  Accordingly, it is possible to recognize that some abnormality has occurred, such as a shift in the detection position by the backward end detection means, a shift in the rotation stop position by the rotation drive means, or a change in the rotation speed. Therefore, it is possible to prevent problems such as being unable to remove the tap from the screw hole.

  According to the sixth aspect of the present invention, the backward movement time of the tap holding means that moves in the tap backward direction is monitored, and from the backward end detection means until the backward movement time becomes longer than the backward movement reference time. When the input of the backward end detection signal is not received, the rotation of the rotation driving means can be stopped. Therefore, for example, even when the arrival of the tap holding means to the backward end cannot be detected due to a detection failure of the backward end detecting means, the rotational driving of the rotational driving means can be stopped. Therefore, it is possible to prevent an abnormal operation such as moving the tap holding means in the tap retraction direction larger than the preset feed movement amount, and to prevent the feed movement means from being defective.

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

  FIG. 1 is an overall view of a tapping apparatus 1 according to the present embodiment, and FIG. 2 is an enlarged view of a main part of FIG.

  As shown in FIG. 1, the tapping apparatus 1 includes a bed 2 installed on the floor, a work holding means 3 for holding the work 101 on the bed 2 in a predetermined posture, and a top surface of the bed 2. The feed unit 4 moves in a direction approaching and separating from the workpiece holding means 3, and the tap unit 5 is provided on the feed unit 4 and forms a screw hole in the screw under hole 102 of the workpiece 101.

  The workpiece holding means 3 is in a posture state in which the machining side surface 103 of the workpiece 101 faces the tap unit 5 and the screw hole 102 formed in the machining side surface 103 extends in the horizontal direction along the moving direction of the feed unit 4. And the cylinder body 12a is provided upright at a side position of the mounting table 11, and the cylinder rod 12b protrudes upward from the upper part of the cylinder body 12a in the vertical direction. A clamp cylinder 12 that expands and contracts, and a clamper 13 that protrudes horizontally at the tip of the cylinder rod 12b, faces the upper surface of the workpiece 101, and holds the workpiece 101 between the mounting table 11 by contraction of the cylinder rod 12b. I have.

  The feed unit 4 includes a pair of guide rails 21 provided so as to extend in a direction approaching and separating from the work holding means 3 along the upper surface of the bed 2, and a slider guided to be reciprocally movable by the guide rails 21. 22, a slide table 23 attached to the upper part of the slider 22 and extending horizontally along the upper surface of the bed 2, and moving the slide table 23 toward and away from the work holding means 3 to set and retract A head feed cylinder 24 that can be selectively arranged at a position is provided.

  The tap unit 5 includes a shaft head 31 provided on the upper surface of the slide table 23 of the feed unit 4, and a tap that is rotatably supported by the shaft head 31 and movable along the rotation axis direction on the rotation center axis. A shaft (tap holding means) 41, a geared motor 51 that rotates the tap shaft 41 in the forward rotation direction that is the tap threading rotation direction and the reverse rotation direction that is the tap extraction rotation direction, and the forward rotation direction and the reverse rotation direction of the tap shaft 41 Is provided with a feed moving means 61 that feeds and moves the tap shaft 41 in the tap forward direction and the tap backward direction according to the rotation of the tap shaft 41, and a detection unit 71 that detects the forward end and the backward end of the tap shaft 41.

  The shaft head 31 has a rectangular box shape, and as shown in FIG. 2, a tap shaft 41 is provided so as to protrude horizontally from the front wall portion 32 toward the workpiece 101, and the rear wall portion 33. Is provided with a geared motor 51.

  The tap shaft 41 is formed of a round bar member extending in a straight line, and the central portion in the axial direction is a guide bush (support means) so that the rotation center axis extends coaxially with the screw hole 102 of the workpiece 101. ) 34 and is supported by the shaft head 31. A socket 42 is provided at the tip of the tap shaft 41, and the tap 43 is detachably supported on the same axis. A master screw portion 62 of the feed moving means 61 is coaxially formed at the proximal end portion of the tap shaft 41, and a spline portion 44 is coaxially formed at the proximal end side.

  The guide bush 34 is formed in a cylindrical body portion 35 having a through hole 35a into which the tap shaft 41 is inserted, and is formed at one end portion of the body portion 35 so as to be bolted to the front wall portion 32. A flange portion 36 that can be fixed to the head 31 is provided, and the tap shaft 41 is supported so as to be rotatable in the forward and reverse directions, and is supported so as to be movable along the axial direction by a preset stroke. It is configured as follows.

  A master screw hole portion 63 that is screwed into the master screw portion 62 of the tap shaft 41 is attached to the other end portion of the body portion 35, and the feed moving means 61 is configured by the master screw portion 62 and the master screw hole portion 63. Is formed.

  The feed moving means 61 is configured to move the tap shaft 41 in the tap forward direction and the tap backward direction at the same pitch as the tap 43 by rotating the tap shaft 41 in the forward direction and the reverse direction.

  The spline portion 44 of the tap shaft 41 is connected to an intermediate gear box 53 provided in the shaft head 31. The intermediate gear box 53 includes a first intermediate gear 54 that is rotatably supported integrally with the motor rotation shaft 51 a of the geared motor 51, and a second intermediate gear 55 that is meshed with the first intermediate gear 54 and is rotatably supported. It has.

  A spline hole 56 is formed at the axial center position of the second intermediate gear 55. The tap shaft 41 is supported so that the spline portion 44 is fitted into the spline hole 56 of the second intermediate gear 55 and can rotate integrally with the second intermediate gear 55 and can move in the axial direction.

  The geared motor 51 can rotate the tap shaft 41 in the forward direction and the reverse direction via the intermediate gear box 53 by receiving power supply from a motor driver 52 described later. There is provided a brake that presses a built-in brake shoe (not shown) against the motor rotation shaft 51a so as to prevent the motor rotation shaft 51a from rotating, and enables the motor rotation shaft 51a to rotate by releasing the brake when energized. ing.

  The detection unit 71 extends on the upper surface of the shaft head 31 along the axial direction of the tap shaft 41, and rises along the axial direction of the tap shaft 41. A pair of bushes 73 facing each other, a guide rod 74 extending in parallel with the tap shaft 41 and supported by the pair of bushes 73 so as to be movable in the axial direction, and one end fixed to the tip of the guide rod 74 The other end of the tap shaft 41 is rotatably connected to the tap shaft 41 and is connected to the tap shaft 41 so as to be integrally movable in the axial direction. The guide rod 74 can be moved in the axial direction in synchronization with the movement.

  The detection unit 71 includes a forward end detection limit switch (forward end detection means) 76 for detecting the forward end of the tap shaft 41 and a backward end detection limit switch for detecting the backward end of the tap shaft 41. (Backward end detection means) 77 is provided.

  The forward end detecting limit switch 76 and the backward end detecting limit switch 77 are fixed to the vertical wall surface of the bracket 72 so as to be positioned above the guide rod 74, and downward from the switch main bodies 76a, 77a. And switch arms 76b and 77b that can swing along the extending direction of the guide rod 74.

  A forward end detecting dog 78 and a backward end detecting dog 79 are attached to the guide rod 74. The forward end detecting dog 78 moves in the tap forward direction together with the guide rod 74 in accordance with the movement of the tap shaft 41 in the tap forward direction. When the tap shaft 41 reaches the forward end, the forward end detection dog 78 is brought into contact with the tip of the switch arm 76b. The switch arm 76b is swung in contact, and the contact of the forward end detection limit switch 76 is switched from OFF to ON.

  Similarly, the backward end detection dog 79 moves in the tap backward direction together with the guide rod 74 in accordance with the movement of the tap shaft 41 in the tap backward direction, and when the tap shaft 41 reaches the backward end, the tip of the switch arm 77b. , The switch arm 77b is swung, and the contact of the backward end detection limit switch 77 is switched from OFF to ON.

  In the present embodiment, six tap units 5 having the above-described configuration are arranged on the slide table 23 of the feed unit 4 at predetermined intervals in a direction orthogonal to the moving direction of the slide table 23. It is provided horizontally.

  FIG. 5 is an explanatory diagram showing a display unit of the tapping apparatus 1.

  A display panel 81 that constitutes a display unit of the tapping device 1 is installed at a position near the tapping device 1 that can be visually recognized by an operator, and a time display unit 84 is provided on the panel surface 82. The time display unit 84 is provided with a forward time display unit 85 in the upper part and a backward time display unit 86 in the lower part. The actually measured movement times are displayed on the upper stages 85a and 86a, respectively, and the upper reference times Tfmax and Trmax of the forward movement reference time and the backward movement reference time are displayed on the lower stages 85b and 86b. In addition, an alarm lamp (abnormality display means) 83 is provided on the panel surface 82, and is configured to be turned on when an abnormality occurs in the tap unit 5 to notify the operator of the abnormality. The time display unit 84 and the alarm lamp 83 are provided on the panel surface 82 for each of the tap units 5 from # 1 to # 6.

  The tapping apparatus 1 having the above configuration is controlled by the control unit 91. FIG. 3 is a diagram for explaining a control system of the tapping apparatus 1 having the above configuration, and FIG. 4 is a functional block diagram of the tapping apparatus 1.

  The control unit 91 is provided in a control panel (not shown) installed in the vicinity of the tapping device 1 and includes a sequence computer and a relay circuit. As shown in FIG. 3, a forward end detection limit switch 76 and a backward end detection limit switch 77 are connected to the input side of the control unit 91. A motor driver 52 that drives the geared motor 51, a time display unit 84, and an alarm lamp 83 are connected to the output side.

  In the controller 91, as shown in FIG. 4, forward end determination means 92, backward end determination means 93, rotation drive signal output means 94, travel time measurement means 95, abnormality determination means 96, and alarm signal output means 97 are provided. It is configured. The forward end determining means 92 determines whether or not the tap shaft 41 is at the forward end based on the detection signal from the forward end detecting limit switch 76, and the backward end determining means 93 is the backward end detecting limit switch 77. Based on the detection signal from, it is determined whether or not the tap shaft 41 is at the retracted end. The determination results by the forward end determination unit 92 and the reverse end determination unit 93 are output to the rotation drive signal output unit 94 and the movement time measurement unit 95.

  The rotation drive signal output means 94 outputs a forward rotation direction rotation drive signal, a reverse rotation direction rotation drive signal, and a rotation stop signal to the motor driver 52. The motor driver 52 energizes the geared motor 51 to rotate the tap shaft 41 in the forward rotation direction when the forward rotation direction rotation drive signal is input, and receives the reverse rotation direction rotation drive signal to move the tap shaft 41 in the reverse rotation direction. The geared motor 51 is energized so as to rotate at the same time. When the rotation stop signal is input, the energization to the geared motor 51 is stopped.

  The movement time measuring means 95 starts time measurement of the forward movement time Tf from when the rotation drive signal output means outputs the forward rotation direction rotation drive signal to the motor driver 52, and outputs the reverse rotation direction rotation drive signal. Measurement of the backward movement time Tr is started, and information on the measured forward movement time Tf and the backward movement time Tr is input to the abnormality determination means 96.

  In the abnormality determination means 96, the measured forward movement time Tf and backward movement time Tr are set in advance in the range of the forward movement reference time (lower limit reference time Tfmin to upper limit reference time Tfmax) and the reverse movement reference time (lower limit reference time Trmin). To determine whether it is within the range of (upper reference time Trmax). When the forward movement reference time (Tfmin to Tfmax) and the backward movement reference time (Trmin to Trmax) are out of range, in other words, the forward movement time Tf is greater than the upper reference time Tfmax of the forward movement reference time. If it is long or shorter than the lower limit reference time Tfmin, or if the backward movement time Tr is longer than the upper reference time Trmax of the backward movement reference time or shorter than the lower reference time Trmin, there is an abnormality in the tap unit 5. Judge that it has occurred.

  Information on the occurrence of abnormality is output to the rotation drive signal output means 94 and the alarm signal output means 97. The range of the forward movement reference time (Tfmin to Tfmax) and the range of the backward movement reference time (Trmin to Trmax) are stored in advance in the storage means of the control unit 91.

  When the alarm signal output means 97 receives the information on the occurrence of an abnormality from the abnormality determination means 96, it outputs an alarm signal to the alarm lamp 83 and turns on the alarm lamp 83 to inform the operator that an abnormality has occurred. .

  Next, the operation of the tapping apparatus 1 having the above configuration will be described below with reference to the flowcharts of FIGS.

  First, when an operator places the workpiece 101 on the mounting table 11 and operates a start button (not shown), the workpiece holding means 3 holds the workpiece 101, and a tapping start command is input to the control unit 91 by the holding. Is done.

  When the tapping start command is input, the controller 91 drives the head feed cylinder 24 of the feed unit 4 to move the slide table 23 from the retracted position to the set position. Thereby, the tap 43 attached to the tip of the tap shaft 41 is opposed to the tip of the tap 43 with a gap of about 5 mm between the workpiece 101 and set coaxially with the screw pilot hole 102.

  Next, in the controller 91, the rotation drive signal output means 94 outputs a forward rotation direction rotation drive signal to the motor driver 52, and the movement time measurement means 95 starts measuring the forward movement time Tf (step S101). The motor driver 52 energizes the geared motor 51 in order to rotate the tap shaft 41 in the normal direction when receiving the input of the normal direction rotation drive signal.

  The geared motor 51 receives power from the motor driver 52, releases the brake, and rotates the motor rotating shaft 51a in the direction in which the tap shaft 41 rotates in the forward rotation direction.

  The rotation of the motor rotation shaft 51a is transmitted from the first intermediate gear 54 of the intermediate gear box 53 to the second intermediate gear 55, transmitted from the second intermediate gear 55 to the tap shaft 41 via the spline portion 44, and the tap shaft 41. Rotate in the forward direction.

  When the tap shaft 41 is rotated in the forward rotation direction, it moves in the tap forward direction by the feed moving means 61. As a result, the tap 43 held at the tip of the tap shaft 41 is screwed into the screw pilot hole 102 of the workpiece 101 from the tip, and threading into the screw pilot hole 102 is started.

  The tap shaft 41 moves in the tap advance direction along with threading of the screw prepared hole 102 by the tap 43, and the guide rod 74 also moves in the tap advance direction in synchronization with the movement.

  When the forward end detection dog 78 of the guide rod 74 contacts the switch arm 76b of the forward end detection limit switch 76 to swing the switch arm 76b and switch the contact point from OFF to ON (YES in step S102). The forward end detection signal is input to the control unit 91. As a result, the forward end determination unit 92 of the control unit 91 determines that the tap shaft 41 has reached the forward end and outputs the information to the rotation drive signal output unit 94.

  When the rotation drive signal output means 94 receives information from the advance end determination means 92 that the advance end has been reached, the rotation drive signal output means 94 outputs a rotation stop signal to the motor driver 52 (step S103), and the motor driver 52 stops the rotation. The energization to the geared motor is stopped based on the signal, the brake is applied, and the rotation of the motor rotating shaft 51a is stopped. Thereby, the rotation of the tap shaft 41 is also stopped, and the threading to the screw prepared hole 102 by the tap 43 is also stopped.

  When it is determined that the forward end has been reached by the forward end determination unit 92 and the rotation stop signal is output from the rotation drive signal output unit 94, the abnormality determination unit 96 causes the rotation drive signal output unit 94 to rotate forward to the motor driver 52. The contact point of the forward end detection limit switch 76 is switched from OFF to ON by the forward end detection dog 78 after the direction rotation drive signal is output, and the forward end determination means 92 detects the forward end from the forward end detection limit switch 76. The forward movement time Tf until the input of the signal (ON) is obtained, and it is determined whether the forward movement time Tf is within a preset forward movement reference time (Tfmin to Tfmax) (step S104). ).

  Here, when the forward movement time Tf is outside the range of the forward movement reference time (Tfmin to Tfmax) (NO in step S104), the abnormality determination means 96 determines that an abnormality has occurred in the tap unit 5 and rotates. The output of the forward direction rotation drive signal and the reverse direction rotation drive signal by the drive signal output means 94 is prohibited, and an alarm signal is output from the alarm signal output means 97 to turn on the alarm lamp 83 of the display panel 81, so that the operator Is notified that an abnormality has occurred (step S108). Since the alarm lamp 83 is provided for each of the tap units 5 from # 1 to # 6, the operator can easily recognize which tap unit 5 has an abnormality.

  On the other hand, when the forward movement time Tf is within the range of the forward movement reference time (Tfmin to Tfmax) (YES in step S104), it is determined to be normal (step S105), and the subsequent processing is continued.

  Further, when the forward movement time Tf exceeds the upper reference time (Tfmax) of the forward movement reference time before the contact of the forward end detection limit switch 76 is switched from OFF to ON (NO in Step S102 and YES in Step S106). ) In other words, if no forward end detection signal is input from the forward end detection limit switch 76 even if the forward movement time Tf has passed the upper limit reference time (Tfmax) of the forward movement reference time, the abnormality determination means 96 determines that an abnormality has occurred and outputs the information to the rotation drive signal output means 94.

  When the rotation drive signal output means 94 receives information on the occurrence of abnormality from the abnormality determination means 96, it outputs a rotation stop signal to the motor driver 52 (step S107). When receiving a rotation stop signal from the rotation drive signal output means 94, the motor driver 52 stops energization to the geared motor 51 and applies a brake to stop the rotation of the motor rotation shaft 51a. Accordingly, the rotation of the tap shaft 41 is also stopped, and the threading of the workpiece 101 into the screw prepared hole 102 by the tap 43 is also stopped.

  The abnormality determination unit 96 prohibits the output of the forward rotation direction rotation drive signal and the reverse rotation direction rotation drive signal by the rotation drive signal output unit 94, and outputs an alarm signal from the alarm signal output unit 97. The alarm lamp 83 is turned on to notify the operator that an abnormality has occurred (step S108).

  Therefore, for example, even when the arrival of the tap shaft 41 at the forward end cannot be detected due to a detection failure of the forward end detection limit switch 76, the rotational drive of the geared motor 51 can be stopped. It is possible to prevent in advance occurrence of problems such as the tip end of the tap 43 bottoming into the bottom of the screw pilot hole 102 and causing tap breakage, or the master screw 62 of the feed moving means 61 falling out of the master screw hole 63. Can do.

  On the other hand, when the forward movement time Tf is within the range of the forward movement reference time (Tfmin to Tfmax) (step S104) and is judged normal (step S105), the rotation drive signal output means 94 reverses to the motor driver 52. A direction rotation drive signal is output, and the measurement of the backward movement time Tr is started (step S201).

  The motor driver 52 energizes the geared motor 51 to rotate the tap shaft 41 in the reverse direction when receiving the reverse rotation direction drive signal from the rotation drive signal output means 94.

  When the geared motor 51 receives power from the motor driver 52 and releases the brake, the geared motor 51 rotates the motor rotating shaft 51a in a direction to rotate the tap shaft 41 in the reverse direction.

  The rotation of the motor rotation shaft 51a is transmitted from the first intermediate gear 54 of the intermediate gear box 53 to the second intermediate gear 55, transmitted from the second intermediate gear 55 to the tap shaft 41 via the spline portion 44, and the tap shaft 41. Rotate in the reverse direction.

  The tap shaft 41 is moved in the reverse direction of the tap by the feed moving means 61 due to the rotation in the reverse direction, and the tap 43 attached to the tip of the tap shaft 41 is rotated in the direction of being extracted from the screw pilot hole 102 of the work 101.

  The tap shaft 41 moves in the tap retracting direction in accordance with the rotation of the tap 43 in the extraction direction, and the guide rod 74 also moves in the tap retracting direction in synchronization with the movement. Then, when the tap 43 is extracted from the screw pilot hole 102 and the tap shaft 41 is further moved in the tap retracting direction, the retracting end detecting dog 79 of the guide rod 74 moves the switch arm 77b of the retracting end detecting limit switch 77. Press to rock. When the contact is switched from OFF to ON (YES in step S202), the backward end determining means 93 determines that the tap shaft 41 has reached the backward end and outputs the information to the rotational drive signal output means 94.

  When the rotational drive signal output means 94 receives information from the backward end determination means 93 that the rear end has been reached, it outputs a rotation stop signal to the motor driver 52 (step S203). When receiving a rotation stop signal from the rotation drive signal output means 94, the motor driver 52 stops energization to the geared motor 51 and applies a brake to stop the rotation of the motor rotation shaft 51a. Thereby, the rotation of the tap shaft 41 is also stopped, and the movement in the tap backward direction is also stopped.

  When it is determined by the reverse end determination means 93 that the reverse end has been reached and the rotation stop signal is output from the rotation drive signal output means 94, the abnormality determination means 96 outputs the rotation drive signal in the reverse direction. The contact point of the reverse end detection limit switch 77 is switched from OFF to ON by the reverse end detection dog 79 from the time of output, and the reverse end determination means 93 receives the reverse end detection signal (ON) from the reverse end detection limit switch 77. The backward movement time Tr until the time when the input is received is obtained, and it is determined whether the backward movement time Tr is within a preset backward movement reference time (Trmin to Trmax) (step S204).

  Here, when the backward movement time Tr is outside the range of the backward movement reference time (Trmin to Trmax) (NO in step S204), the abnormality determining means 96 determines that some abnormality has occurred in the tap unit 5. The rotation drive signal output means 94 prohibits the output of the forward rotation direction rotation drive signal and the reverse rotation direction rotation drive signal, and also outputs an alarm signal from the alarm signal output means 97 to turn on the alarm lamp 83 of the display panel 81, The operator is notified that an abnormality has occurred (step S208).

  On the other hand, when the backward movement time Tr is within the range of the backward movement reference time (Trmin to Trmax) (YES in step S204), it is determined that it is normal (step S205), and the slide table 23 of the feed unit 4 is moved to the retracted position. To complete the tapping operation.

  Further, when the backward movement time Tr exceeds the upper reference time (Trmax) of the backward movement reference time before the contact of the backward end detection limit switch 77 switches from OFF to ON (NO in step S202 and YES in step S206). ) In other words, if the backward movement detection time Tr does not receive the backward movement detection signal from the backward movement detection limit switch 77 even after the upper reference time (Trmax) of the backward movement movement reference time has elapsed, the abnormality determination means 96 determines that an abnormality has occurred and outputs the information to the rotation drive signal output means 94.

  When the rotation drive signal output means 94 receives the information on the occurrence of abnormality from the abnormality determination means 96, it outputs a rotation stop signal to the motor driver 52 (step S207). When receiving a rotation stop signal from the rotation drive signal output means 94, the motor driver 52 stops energization to the geared motor 51 and applies a brake to stop the rotation of the motor rotation shaft 51a. Accordingly, the rotation of the tap shaft 41 is also stopped, and the movement of the tap 43 in the tap backward direction is also stopped.

  The abnormality determination unit 96 prohibits the output of the forward rotation direction rotation drive signal and the reverse rotation direction rotation drive signal by the rotation drive signal output unit 94, and outputs an alarm signal from the alarm signal output unit 97. The alarm lamp 83 is turned on to notify the operator that an abnormality has occurred (step S208).

  FIG. 8 is a diagram for explaining the operation state of the tapping device 1 when it is normal and when it is abnormal. In this embodiment, the forward movement reference time and the backward movement reference time are set to 6.9 seconds ± 0.3.

  In the case shown in FIG. 8A, the period from when the forward rotation direction rotation drive signal is output to the motor driver 52 until the forward end determination means 92 inputs the forward end detection signal from the forward end detection limit switch 76. The forward movement time Tf is 6.9 seconds, and is within the range of the forward movement reference time (Tfmin to Tfmax). The reverse movement time Tr from when the reverse rotation direction rotation drive signal is output to the motor driver 52 until the reverse end determination means 93 inputs the reverse end detection signal from the reverse end detection limit switch 77 is 6.9 seconds. Yes, it is in the range of reverse movement reference time (Trmin to Trmax). Therefore, the tap unit 5 is operating normally and can continue tapping.

  In the case shown in FIG. 8B, the forward movement time Tf and the reverse movement time Tr are longer than the normal time of 6.9 seconds due to brake shoe dragging and brake shoe wear due to brake release failure. .8 seconds. Therefore, there is a risk that the cycle time is extended due to the increase of the processing time, and the production efficiency is lowered.

  However, conventionally, the stop position of the tap shaft 41 is merely controlled based on the forward end detection signal from the forward end detection limit switch 76 and the backward end detection limit switch 77 and the backward end detection signal. The abnormality of the geared motor 51 could not be recognized.

  On the other hand, the tapping device 1 according to the present embodiment has the forward movement time of the tap shaft 41 in addition to the forward end detection signal of the forward end detection limit switch 76 and the backward end detection signal of the backward end detection limit switch 77. Tf and reverse movement time Tr are monitored.

  Therefore, when the forward movement time Tf is not within the range of the forward movement reference time (Tfmin to Tfmax) due to an abnormality of the geared motor 51 as in this case, or when the upper reference time Tfmax of the forward movement reference time is exceeded, When the movement time Tr is not within the range of the backward movement reference time (Trmin to Trmax) and exceeds the upper limit reference time Trmax of the backward movement reference time, it is recognized that some abnormality has occurred in the tap unit 5. can do.

  In the case shown in FIG. 8C, the forward end detection position is displaced in the tap forward direction from the normal position due to the poor sensitivity of the forward end detection limit switch 76. Therefore, the tap 43 may be screwed into a deeper position than specified in the screw pilot hole 102 and the tap may be broken.

  However, conventionally, only the stop position of the tap shaft 41 is controlled using the forward end detection signal of the forward end detection limit switch 76, and the occurrence of an abnormality due to the poor sensitivity of the forward end detection limit switch 76 is recognized. I couldn't.

  On the other hand, the tapping device 1 in the present embodiment monitors the forward movement time Tf and the backward movement time Tr of the tap shaft 41 in addition to the detection signal of the forward end detection limit switch 76.

  Therefore, the forward movement time Tf is not within the range of the forward movement reference time (Tfmin to Tfmax) due to the abnormality of the forward end detection limit switch 76 as in this case, and exceeds the upper limit reference time Tfmax of the forward movement reference time. In this case, it is possible to recognize that some abnormality has occurred in the limit switch system including the dog or the tap unit 5.

  According to the tapping device 1 having the above-described configuration, the forward movement time Tf of the tap shaft 41 is monitored, and the forward end detection signal is output from the forward end detection limit switch 76 from when the forward rotation direction rotational drive signal is output to the motor driver 52. The forward movement time Tf from when the forward movement time Tf is not within the range of the forward movement reference time (Tfmin to Tfmax) or when the forward rotation direction rotation drive signal is output to the motor driver 52 is measured. When the forward movement time Tf exceeds the upper reference time (Tfmax) of the forward movement reference time before the contact of the forward end detection limit switch 76 is switched from OFF to ON, it is determined that an abnormality has occurred.

  Similarly, the backward movement time of the tap shaft 41 is monitored, and the backward movement time Tr from when the reverse direction rotation drive signal is output to the motor driver 52 until when the backward end detection signal is input from the backward end detection limit switch 77. Is not within the range of the reverse movement reference time (Trmin to Trmax), or the reverse movement time Tr starts to be measured from when the reverse direction rotation drive signal is output to the motor driver 52, and the reverse end detection limit switch If the backward movement time Tr exceeds the upper limit reference time (Trmax) of the backward movement reference time before the contact 77 switches from OFF to ON, it is determined that an abnormality has occurred.

  Accordingly, for example, when the forward end or the backward end of the tap shaft 41 cannot be detected due to an abnormality in the forward end detection limit switch 76 or the backward end detection limit switch 77, the forward end detection limit switch 76, When the detection position of the forward end or the backward end is displaced from the normal position to the tap forward direction side or the tap backward direction side due to the poor sensitivity of the backward end detection limit switch 77, the stop position due to the brake failure of the geared motor 51 It is possible to recognize that some abnormality has occurred in the tap unit 5 such as a deviation of the speed, a change in the rotational speed of the geared motor 51, and the like.

  For example, when the brake of the geared motor 51 breaks down when the tap shaft 41 moves in the tap backward direction, and the tap shaft 41 stops at a position shifted further in the tap backward direction than the backward end, the tap forward direction in the next cycle. When moving to, it takes a long time to reach the forward end, and it can be determined that the brake is abnormal.

  When an abnormality occurs, the geared motor 51 is quickly stopped to stop the rotation of the tap shaft 41 and the rotation of the geared motor 51 is prohibited. For example, the master screw portion 62 of the feed moving means 61 is set in advance. It is possible to prevent the feed moving means 61 from having troubles such as moving more than the feed movement amount that has been moved and coming off the master screw hole 63 or the master screw 62 being bitten into the master screw hole 63. Can do.

  Further, it is possible to prevent movement larger than a preset feed movement amount, and it is possible to prevent problems such as breakage of the tap 43, defective formation of the screw hole, defective extraction from the screw pilot hole 102, and the like. The processing accuracy of processing can always be made constant.

  Since the forward movement time Tf, the forward movement reference time (Tfmin to Tfmax), the backward movement time Tr and the backward movement reference time (Trmin to Trmax) are displayed side by side on the surface 82 of the display panel 81, the forward movement of the tap shaft 41 is performed. The time Tf, the forward movement reference time (Tfmin to Tfmax), the backward movement time Tr and the backward movement reference time (Trmin to Trmax) can be viewed at a time, and the current state of the tap unit 5 can be easily grasped. Therefore, for example, when an abnormality occurs, the forward movement time Tf and the forward movement reference time (Tfmin to Tfmax), or the backward movement time Tr and the backward movement reference time (Trmin to Trmax) are compared with each other to consider the time difference. 5 can be easily identified.

  Moreover, since the alarm lamp 83 is provided for each tap unit 5 on the panel surface 82 of the display panel 81, it is possible to easily recognize which of the plurality of tap units 5 is abnormal, Subsequent countermeasures such as parts replacement can be quickly performed.

  In addition, this invention is not limited to the above-mentioned embodiment, A various change is possible in the range which does not deviate from the meaning of this invention. For example, a case where the above-described forward movement reference time range (Tfmin to Tfmax) and the backward movement reference time range (Trmin to Trmax) are set in advance and stored in the storage unit of the control unit 91 will be described as an example. However, it may be configured such that it can be changed by inputting from the input means 87 provided at the lower part of each display portion of the forward time display portion 85 and the backward time display portion 86.

1 is an overall view of a tapping apparatus according to an embodiment. It is a principal part enlarged view of FIG. It is a figure explaining the control system of a tapping apparatus. It is a functional block diagram of a tapping device. It is a figure which shows the display part of a tapping apparatus. It is a flowchart explaining a forward movement operation | movement. It is a flowchart explaining reverse movement operation | movement. It is a figure for comparing and explaining the operation state at the time of normal and abnormal of a tapping device.

Explanation of symbols

1 Tapping device 34 Guide bush (support means)
41 Tap shaft (tap holding means)
43 Tap 51 Geared motor (rotation drive means)
61 Feed moving means 76 Limit switch for forward end detection (forward end detection means)
77 Limit switch for reverse end detection (reverse end detection means)
83 Alarm lamp (Abnormality display means)
84 Time display section 85 Advance time display section (advance time display means)
86 Backward time display section (backward time display means)
91 Control unit (control means)
92 Forward end determination means 93 Backward end determination means 94 Rotation drive signal output means 95 Travel time measurement means 96 Abnormality determination means 97 Alarm signal output means 101 Work 102 Screw pilot hole
Tf Forward movement time
Tr Reverse movement time
Tfmin to Tfmax Forward movement reference time
Trmin to Trmax Backward movement reference time

Claims (6)

Tap holding means for holding the tap;
A support means for supporting the tap holding means so as to be rotatable coaxially with the rotation center axis and movably supporting the tap advance direction and the tap retreat direction along the rotation center axis;
Rotation driving means for rotating the tap holding means rotatably supported by the support means in the forward rotation direction and the reverse rotation direction;
The tap holding means is moved in the forward direction of the tap in accordance with the rotation of the tap holding means in the forward rotation direction by the rotation driving means, and in response to the rotation of the tap holding means in the reverse direction by the rotation driving means. Feed moving means for moving the tap holding means in the tap retraction direction;
Forward end detection means for outputting a forward end detection signal by contacting the tap holding means that moves in the tap forward direction by the feed movement means;
A retreat end detection means for outputting a retreat end detection signal by contacting the tap holding means moving in the tap retreat direction by the feed movement means;
Based on a predetermined tapping start command, a forward rotation direction rotation drive signal is output to the rotation drive means, the tap holding means is rotated in the forward rotation direction and moved in the tap forward direction, and the forward end detection means is moved to the forward end. Upon receipt of a detection signal, a reverse rotation direction rotation drive signal is output to the rotation drive means, the tap holding means is rotated in the reverse rotation direction and moved in the tap backward direction, and the backward end detection means is detected from the backward end detection means. A tapping device having control means for receiving a signal input and outputting a rotation stop signal to the rotation driving means to stop the rotation of the tap holding means;
The control means is configured to advance in which a forward movement time from when the forward rotation direction rotation drive signal is output to the rotation drive means to when a forward end detection signal is received from the forward end detection means is set in advance. A tapping device characterized in that when it is longer than the movement reference time, it is determined that an abnormality has occurred and output of the forward rotation direction rotation drive signal and the reverse rotation direction rotation drive signal to the rotation drive means is prohibited.   The control means is configured to advance in which a forward movement time from when the forward rotation direction rotation drive signal is output to the rotation drive means to when a forward end detection signal is received from the forward end detection means is set in advance. 2. The tapping according to claim 1, wherein when the time is shorter than the movement reference time, it is determined that an abnormality has occurred, and output of the forward rotation direction rotation drive signal and the reverse rotation direction rotation drive signal to the rotation drive unit is prohibited. apparatus.   The control means starts measuring the forward movement time from when the forward rotation direction rotation drive signal is output to the rotation drive means, and receives the forward end detection signal from the forward end detection means. If it becomes longer than the forward movement reference time before, a rotation stop signal is output to the rotation drive means and it is determined that an abnormality has occurred, and the forward rotation direction rotation drive signal and the reverse rotation are determined for the rotation drive means. The tapping device according to claim 1 or 2, wherein the output of the direction rotation drive signal is prohibited.   The control means has a backward movement time set in advance from when the reverse rotation direction rotation drive signal is output to the rotation drive means until when the backward end detection signal is input from the backward end detection means. 4. The method according to claim 1, wherein when the time is longer than a reference time, it is determined that an abnormality has occurred and output of the forward rotation direction rotation drive signal and the reverse rotation direction rotation drive signal to the rotation drive means is prohibited. The tapping apparatus according to item 1.   The control means has a reverse movement reference in which a reverse movement time from when the reverse rotation direction rotation drive signal is output to the rotation drive means to when a reverse end detection signal is input from the reverse end detection means is preset. 5. The tapping apparatus according to claim 4, wherein when the time is shorter than the time, it is determined that an abnormality has occurred, and the output of the forward rotation direction rotation drive signal and the reverse rotation direction rotation drive signal to the rotation drive means is prohibited.   The control means starts measuring the backward movement time from when the reverse rotation direction rotational drive signal is output to the rotational drive means, and the backward movement time is input from the backward end detection means to the backward end detection signal. If the reference time is longer than the reverse movement reference time before, a rotation stop signal is output to the rotation drive means, and it is determined that an abnormality has occurred, and the forward rotation direction rotation drive signal and the reverse rotation direction to the rotation drive means are determined. 6. The tapping device according to claim 4, wherein output of the rotation drive signal is prohibited.

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