Bar stock processing system

Abstract

To provide a rod stock machining system capable of significantly suppressing application of an excessive load (axial compressing load) on a rod stock even when a moving direction of a spindle base is reversed during machining of the rod stock or the like.SOLUTION: This rod stock machining system comprises: a rod stock machine having a spindle base moved; a rod stock feeder that pushes a rear end of a rod stock in by a feed member to move the rod stock forward; and a synchronizer that can synchronize movement of the spindle base of the rod stock machine and movement of the feed member of the rod stock machine in an advancing / retreating direction of the rod stock. The rod stock feeder includes a drive motor that can provide moving force to the feed member of the rod stock feeder. The drive motor is drive-controlled in accordance with a change state of the spindle base in the moving direction in a state where the movement of the spindle base and the movement of the feed member are synchronized by the synchronizer.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a bar processing system comprising: a bar processing machine; and a bar feeder that advances a bar (generally a steel or resin material having a diameter of approximately φ12 or less) by pushing the rear end of the bar with a feed member. [Background Art]

[0002] Conventionally, there has been known a bar processing system comprising: a bar processing machine having a movable headstock (also called a "headstock moving type bar processing machine"); a bar feeder that advances a bar by pushing the rear end of the bar with a feed member (also called a "feed pusher"); and a synchronization device capable of synchronizing the movement of the headstock of the bar processing machine and the movement of the feed member of the bar feeder in the forward and backward moving directions of the bar.

[0003] The feed member is generally connected to an endless chain wound around a sprocket rotationally driven by a motor. A finger chuck for gripping the rear end of the bar is provided at the front end of the feed member, and the rear end of the bar is adapted to be inserted into the finger chuck.

[0004] As the feed member moves forward along with the travel of the endless chain, the bar is fed toward the bar processing machine. When the front end of the bar moves to a predetermined position of the bar processing machine (for example, a position defined by a stopper portion), the bar is gripped by a collet chuck of the bar processing machine. Thereafter, the bar is processed while the headstock moves back and forth.

[0005] During bar processing in which the headstock of the bar processing machine moves, it is preferable that the feed member moves in synchronization with the movement of the headstock so that the rear end of the bar does not slip out of the finger chuck and an excessive load is not applied to the bar. For this purpose, a synchronization device is provided.

[0006] For example, Patent Document 1 by the applicant presents a configuration comprising an endless chain 122 for a feed member 112 supporting the feed member 112, a feed member interlocking rotary body 120 that rotates in conjunction with the movement of the endless chain 122, an endless chain 150 for a headstock connected to a headstock 106, and a headstock interlocking rotary body 148 that rotates in conjunction with the movement of the endless chain 150. In this configuration, the feed member interlocking rotary body 120 and the headstock interlocking rotary body 148 are detachably connected by a clutch means 130 (an example of a synchronization device) (see Figure 11: a figure corresponding to Figure 1 of Patent Document 1). When the clutch means 130 is released, the feed member 112 can be moved by the drive motor 149 independently of the movement of the headstock 106 (it is possible to provide the movement force of the feed member 112 independently of the movement force of the headstock 106).

[0007] Furthermore, Patent Document 2 by the applicant in this case proposes a configuration that, based on the setup shown in Figure 11, allows for inexpensive and accurate confirmation that the diameter of the rod material is appropriate for the collet chuck. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2001-246502 [Patent Document 2] Patent No. 6784392 [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] In the configurations shown in Patent Documents 1 and 2, when the clutch means 130 is engaged, the movement of the headstock 106 and the movement of the feed member 112 are synchronized in the direction of feeding the rod material.

[0010] The applicant has found that, in such a synchronous drive state, driving the drive motor 149 maintains (remains) a predetermined load (axial compressive load) on the bar material between the headstock 106 and the feed member 112 in the bar material feeding direction, which is effective in stabilizing the bar material during bar material processing, and has adopted this in its actual product lineup.

[0011] Specifically, the drive current value of the drive motor 49 is set such that the torque load on the drive motor 149 when driving the movement of the feed member 112 is approximately a desired value (for example, about 1.7 Nm).

[0012] The inventors of this case have found that when the drive current value of the drive motor 149 is set uniformly, when the direction of movement of the headstock 106 and / or the direction of movement of the feed member 112 are reversed during the machining of the bar material, a load (axial compressive load) exceeding the desired range may be generated on the bar material (see Figure 4).

[0013] The present invention was conceived based on the above findings. The object of the present invention is to provide a bar processing system that can significantly suppress the occurrence of excessive load (axial compressive load) on the bar material even when the direction of movement of the headstock and / or the direction of movement of the feed member are reversed during the processing of the bar material. [Means for solving the problem]

[0014] One aspect of the present invention is a bar stock processing system comprising: a bar stock processing machine having a moving headstock; a bar stock feeding machine that advances a bar stock by pushing the rear end of the bar stock with a feed member; and a synchronization device capable of synchronizing the movement of the headstock of the bar stock processing machine and the movement of the feed member of the bar stock feeding machine in the forward and backward directions of the bar stock, wherein the bar stock feeding machine has a drive motor capable of providing moving force to the feed member of the bar stock feeding machine, and the drive motor is driven and controlled in accordance with the change in the direction of movement of the headstock and / or the direction of movement of the feed member, while the movement of the headstock and the movement of the feed member are synchronized by the synchronization device.

[0015] According to this aspect of the present invention, the drive motor is controlled to move in accordance with the changes in the direction of movement of the headstock and / or the direction of movement of the feed member, while the movement of the headstock and the movement of the feed member are synchronized by a synchronization device. This effectively suppresses the occurrence of a load (axial compressive load) on the bar stock that exceeds a desired range.

[0016] The concept of the present invention is also effective in bar stock processing systems that do not have a synchronization device. In bar stock processing systems that do not have a synchronization device, the bar stock itself acts as an intermediary, transmitting the movement of the headstock to the feed member, which then moves in conjunction with the feed member. Even in such cases, the concept of the present invention is effective.

[0017] In other words, one aspect of the present invention is a bar processing machine comprising a spindle head that moves, and a bar feeder that advances the bar by pushing the rear end of the bar with a feeder, wherein the bar feeder has a drive motor capable of providing moving force to the feeder of the bar feeder, and the drive motor is driven and controlled in accordance with the change in the direction of movement of the spindle head and / or the direction of movement of the feeder, while the movement of the spindle head is transmitted by the bar as the movement of the feeder.

[0018] According to this aspect of the present invention, the drive motor is controlled to drive in accordance with the change in the direction of movement of the headstock and / or the direction of movement of the feed member, while the movement of the headstock is transmitted by the rod itself as the movement of the feed member. This effectively suppresses the occurrence of a load (axial compressive load) on the rod that exceeds a desired range.

[0019] Furthermore, the concept of the present invention can also be effectively used in a bar processing system where the headstock does not move, for controlling the positioning of the tip of the bar by bringing it into contact with a stopper.

[0020] In other words, one aspect of the present invention is a bar processing machine having a stopper portion for positioning the tip of a bar, and a bar feeding machine that advances the bar by pushing the rear end of the bar with a feeding member, wherein the bar feeding machine has a drive motor capable of providing movement force to the feeding member of the bar feeding machine, and the drive motor is driven and controlled in accordance with the change in the direction of movement of the feeding member when the resistance force received from the stopper portion after the tip of the bar reaches the stopper portion is transmitted to the feeding member by the bar.

[0021] According to this aspect of the present invention, the drive motor is controlled to move in accordance with the change in the direction of movement of the feed member while the resistance force received from the stopper portion is transmitted to the feed member by the rod, thereby effectively suppressing the occurrence of a load (axial compressive load) on the rod that exceeds a desired range.

[0022] Specifically, for example, the driving force of the drive motor is preferably smaller when the headstock and / or the feed member starts to move in the backward direction of the bar than when the headstock is moving in the forward direction of the bar, under any one of the following conditions: a state where the movement of the headstock and / or the movement of the feed member are synchronized by the synchronization device, a state where the movement of the headstock is transmitted as the movement of the feed member via the bar, or a state where the resistance force received from the stopper portion after the front end portion of the bar reaches the stopper portion is transmitted to the feed member via the bar.

[0023] According to this, the driving force of the drive motor is reduced at the timing when the moving direction of the headstock and / or the moving direction of the feed member is reversed, which can effectively suppress the occurrence of a load (axial compressive load) on the bar that exceeds a desired range. In addition, the reduction of driving force means the reduction of power consumption, which contributes to energy saving and environmental protection.

[0024] Alternatively, for example, the driving force of the drive motor is preferably smaller when a predetermined time has elapsed after the headstock and / or the feed member starts moving in the backward direction of the bar than when the headstock and / or the feed member is moving in the forward direction of the bar, under any one of the following conditions: a state where the movement of the headstock and the movement of the feed member are synchronized by the synchronization device, a state where the movement of the headstock is transmitted as the movement of the feed member via the bar, or a state where the resistance force received from the stopper portion after the front end portion of the bar reaches the stopper portion is transmitted to the feed member via the bar.

[0025] According to this configuration, the driving force of the drive motor is reduced at a timing when a predetermined time has elapsed after the moving direction of the headstock and / or the moving direction of the feed member is reversed. Therefore, while effectively suppressing the occurrence of a load (axial compressive load) exceeding a desired range on the bar material, the frequency of drive control of the drive motor can be suppressed, which in turn reduces the risk of failure occurrence. Furthermore, since the reduction in driving force means a reduction in power consumption, this achieves energy saving and can contribute to environmental protection.

[0026] Alternatively, for example, the driving force of the drive motor is under a state where the movement of the headstock and the movement of the feed member are synchronized by the synchronizing device, or under a state where the movement of the headstock is transmitted as the movement of the feed member via the bar material, or under a state where the resistance force received from the stopper portion after the tip end of the bar material reaches the stopper portion is transmitted to the feed member via the bar material, when the headstock and / or the feed member starts to move in the backward direction of the bar material, the driving force is smaller than that when the headstock and / or the feed member is moving in the forward direction of the bar material, and when a predetermined time has elapsed after the headstock and / or the feed member starts to move in the backward direction of the bar material, the driving force is preferably even smaller than that when the headstock and / or the feed member starts to move in the backward direction of the bar material.

[0027] According to this configuration, the driving force of the drive motor is reduced in two steps at the timing when the moving direction of the headstock and / or the moving direction of the feed member is reversed, and at the timing when a predetermined time has elapsed after the moving direction of the headstock and / or the moving direction of the feed member is reversed. Therefore, when the rotation returns to the normal rotation direction again while the driving force is reduced in one step, the followability to the rise of rotation to normal rotation can be improved. Furthermore, since the reduction in driving force means a reduction in power consumption, this achieves energy saving and can contribute to environmental protection.

[0028] Furthermore, each of the above inventions is also similarly applicable to a case where the moving direction of the headstock and / or the moving direction of the feed member returns to the original direction again.

[0029] In other words, for example, it is preferable that the driving force of the drive motor is greater when the headstock and / or feed member begin to move again in the forward direction of the rod when the headstock and / or feed member begin to move in the reverse direction of the rod, when the movement of the headstock and / or feed member begin to move in the reverse direction of the rod, when the movement of the headstock and / or feed member begin to move in the forward direction of the rod, when the movement of the headstock and / or feed member begins to move in the reverse direction of the rod, when the movement of the headstock and / or feed member begins are synchronize

[0030] According to this, the driving force of the drive motor is increased (for example, returned to its original position) at the moment when the headstock movement direction and / or the feed member returns to its original direction, so that it can smoothly follow the forward movement of the headstock or the stopper and stably feed the bar stock to the bar stock processing machine.

[0031] Alternatively, for example, the driving force of the drive motor is preferably greater than when the headstock and / or the feed member are moving in the reverse direction of the rod when a predetermined time has elapsed since the headstock and / or the feed member began moving again in the forward direction of the rod, under conditions where the movement of the headstock and the movement of the feed member are synchronized by the synchronization device, or where the movement of the headstock is transmitted as the movement of the feed member by the rod, or where the resistance force received from the stopper after the tip of the rod reaches the stopper is transmitted to the feed member by the rod.

[0032] According to this, the driving force of the drive motor is increased (for example, returned to its original position) at a predetermined time after the headstock movement direction and / or the feed member have returned to their original direction. This effectively suppresses the occurrence of loads (axial compressive loads) on the rod that exceed the desired range, while also reducing the frequency of drive motor control, and consequently reducing the risk of malfunction.

[0033] Alternatively, for example, it is preferable that the driving force of the drive motor is greater than when the headstock and / or the feed member is moving in the reverse direction of the rod when the headstock and / or the feed member starts moving again in the forward direction of the rod when the headstock and / or the feed member starts moving again in the forward direction of the rod when the headstock and / or the feed member starts moving in the reverse direction of the rod when a predetermined time has elapsed since the headstock and / or the feed member started moving again in the forward direction of the rod.

[0034] According to this, the driving force of the drive motor is increased in two stages: once when the spindle head returns to its original direction of movement and / or the feed member returns to its original direction, and again when a predetermined time has elapsed since the spindle head returned to its original direction of movement and / or the feed member returned to its original direction. Therefore, when the spindle head returns to the reverse direction again while the driving force is being increased by one stage, the ability to follow up until the torque is reduced can be improved.

[0035] Alternatively, for example, it is preferable that the driving force of the drive motor is greater when the headstock begins to move in the reverse direction of the rod than when the headstock and / or the feed member are moving in the forward direction of the rod, and smaller when a predetermined time has elapsed since the headstock began to move in the reverse direction of the rod than when the headstock and / or the feed member began to move in the reverse direction of the rod.

[0036] According to this, the driving force of the drive motor is set in two stages: at the timing when the direction of movement of the headstock and / or the feed member returns to their original direction, and at the timing when a predetermined time has elapsed since the direction of movement of the headstock and / or the feed member returned to their original direction. For example, the change in driving force at the former timing allows the motor to follow the forward movement of the headstock or the forward movement of the stopper part more quickly (preferably instantaneously), and the change in driving force at the latter timing allows the motor to return to its original driving force.

[0037] Furthermore, the drive motor is controlled based on a drive current command, and the value of the drive current command is switched according to each of a plurality of states (for example, before and after a change in the movement direction of the headstock and / or the movement direction of the feed member). Preferably, the value of the drive current command corresponding to each of the plurality of states can be set arbitrarily. This makes fine adjustments at the actual system installation site easier.

[0038] Furthermore, the change in the movement direction of the headstock and / or the movement direction of the feed member is detected by the rotation of the encoder mechanism, and it is preferable that the threshold for determining the change in rotation direction based on the rotation of the encoder mechanism can be set arbitrarily. For example, in detecting reverse rotation, setting a small margin, such as setting the threshold to "-50rpm" instead of "0rpm", can effectively prevent false detection of reverse rotation. Similarly, in subsequent detection of reverse rotation, setting a small margin, such as setting the threshold to "+50rpm" instead of "0rpm", can effectively prevent false detection. [Effects of the Invention]

[0039] According to the present invention, when the movement of the headstock and the movement of the feed member are synchronized by a synchronization device, or when the movement of the headstock is transmitted as the movement of the feed member by the rod, or when the resistance force received from the stopper after the tip of the rod reaches the stopper is transmitted to the feed member by the rod, the drive motor is driven and controlled according to the change in the direction of movement of the headstock and / or the direction of movement of the feed member, thereby effectively suppressing the occurrence of a load (axial compressive load) on the rod that exceeds a desired range. [Brief explanation of the drawing]

[0040] [Figure 1] This is a side view of a bar stock processing system according to one embodiment of the present invention. [Figure 2] Figure 1 is a side view of the bar material feeding machine. [Figure 3] Figures 1 and 2 are plan views of the bar material feeding machine. [Figure 4] This graph shows a first embodiment of the command current control of the drive motor in this embodiment. [Figure 5] This graph illustrates the reduction in the load on the rod material by the first embodiment shown in Figure 4. [Figure 6] This graph shows a second embodiment of the command current control of the drive motor in this embodiment. [Figure 7] This graph shows a third embodiment of the command current control of the drive motor in this embodiment. [Figure 8] This graph shows a fourth embodiment of the command current control of the drive motor in this embodiment. [Figure 9] This is a side view of a bar stock processing system without a synchronization device. [Figure 10] This is a schematic diagram showing the stopper section of a bar stock processing machine. [Figure 11] This is a schematic perspective view of a conventional bar material feeding machine (corresponding to Figure 1 of Patent Document 1). [Modes for carrying out the invention]

[0041] Embodiments of the present invention will be described below with reference to the drawings.

[0042] (Basic configuration) Figure 1 is a side view of a bar processing system according to one embodiment of the present invention, Figure 2 is a side view of the bar feeding machine of Figure 1, and Figure 3 is a plan view of the bar feeding machines of Figures 1 and 2.

[0043] As shown in Figures 1 to 3, the bar stock processing system 1 comprises a spindle-moving type bar stock processing machine 2 and a bar stock supply machine 4 for supplying bar stock W to the bar stock processing machine 2.

[0044] The bar stock processing machine 2 includes a headstock 6 that moves back and forth along the feed axis OO of the bar stock W, a spindle 8 that extends within the headstock 6 along the feed axis OO, a collet chuck 10 located near the tip of the spindle 8 for gripping the bar stock W, a guide bush 12 located in front of the headstock 6 and positioned on the feed axis OO, and a parting tool 14 for cutting off the bar stock W.

[0045] On the other hand, the bar material feeder 4 includes a guide rail 16 that extends along the feeding axis OO and has a cover portion (not shown), a feed member 18 for feeding bar material W to the bar material processing machine 2 along the guide rail 16, a feed member drive device 20 for moving the feed member back and forth, a bar material supply means (not shown) for supplying new bar material W to the guide rail 16, a leftover material box portion 26 for disposing of leftover material after the completion of product processing, an oil injection device (not shown) for injecting oil into the guide rail 16 to support the bar material W straight on the feeding axis OO during bar material processing, etc., and a clamp device (not shown) for holding the rear end of the bar material W in place so that it does not move while it is being inserted into the receiving portion of the feed member 18.

[0046] The feed member 18 comprises a pushing member body 18a and a rod holder portion 18b provided at the tip of the pushing member body 18a. The rod holder portion 18b has a cylindrical receiving portion into which the rear end of the rod W can be inserted. The feed member 18 also has a fin 18c for connecting to an endless chain 20d.

[0047] The feed member drive device 20 includes a sprocket 20a provided near the front and rear ends of the guide rail 16, an endless chain 20b wrapped around the sprocket 20a, and a servo motor 20c which is a drive motor for driving the endless chain 20b. The blades 18c of the feed member 18 are connected to the endless chain 20b.

[0048] Furthermore, a synchronization device 22 is provided for synchronizing the headstock 6 and the feed member 18, and a control unit 24 is provided for controlling the operation of the bar stock feeder 4 and the bar stock processing machine 2.

[0049] The synchronization device 22 includes a connecting plate 22a for connecting to the headstock 6, a connecting rod 22b whose front end is connected to the headstock 6 via the connecting plate 22a and which extends straight parallel to the guide rail 16, an endless chain 22d which is wrapped around a pair of sprockets 22c along the guide rail 16 and supported, and connected to the connecting rod 22b, and a synchronization clutch 22e which releasably synchronizes (connects) the endless chain 20b and the endless chain 22d.

[0050] (basic action) As an initial state, the headstock 6 is assumed to be in a standby position P2 between the retracted position P1 and the forward position P3, and the feed member 18 is assumed to be retracted behind the guide rail 16.

[0051] When the bar processing system 1 is started, a new bar W is fed into the guide rail 16. The tip of the bar W is then gripped by a bar clamping device (not shown) provided on the bar supply machine 4. Next, the servo motor 20c is driven, and the feed member 18 moves forward, inserting the rear end of the bar W into the receiving part of the bar holding section 18b. After that, the bar clamping device is released, and the feed member 18 moves further forward by the servo motor 20c, inserting the tip of the bar W into the spindle 8 and feeding it to just before the guide bush 12.

[0052] Next, the collet chuck 10 closes, gripping the tip of the bar stock W. Furthermore, the synchronization device 22 synchronizes the movement of the headstock 6 and the movement of the feed member 18 in the forward and reverse directions. Specifically, the synchronization clutch 22e is engaged, synchronizing the movement of the endless chain 20b and the endless chain 22d, thereby synchronizing the movement of the headstock 6 and the movement of the feed member 18.

[0053] Under these synchronized conditions, the tip of the rod W is inserted into the guide bush 12.

[0054] For example, the portion of the rod W that should be cut off (the tip portion Ymm) is moved to a position where it protrudes in front of the parting tool 14, i.e., the cut-off position, and is then cut off by the parting tool 14.

[0055] Next, the collet chuck 10 opens, the synchronization of the synchronization device 22 is released, and the headstock 6 is retracted by the product machining length. Then, the collet chuck 10 closes again, gripping the new end of the bar stock W, and the synchronization device 22 synchronizes the movement of the headstock 6 and the movement of the feed member 18 again in the forward and reverse directions.

[0056] Under these synchronized conditions, a new tip of the bar W is inserted into the guide bush 12 and cut off, for example, by a parting tool 14.

[0057] The aforementioned processing steps are repeated until the bar material W reaches a length that can no longer be used to process the product, at which point the bar material W is discarded as waste material in the waste material box section 26.

[0058] (Characteristic effects of this embodiment) Now, the bar stock processing system 1 of this embodiment can significantly suppress the occurrence of excessive load (axial compressive load) on the bar stock W even when the direction of movement of the headstock 6 is reversed during the processing of the bar stock W. This characteristic function will be explained below.

[0059] In this embodiment, the servo motor 20c is driven and controlled by a PLC (not shown) and a servo amplifier (not shown) provided in the control unit 24. More specifically, the PLC and the servo amplifier provide the servo motor 20c with a preset drive current command (selected from eight current values ​​in this embodiment) according to conditions based on the change in the movement direction of the headstock 6 (in this embodiment, according to the change in the movement direction of the feed member 18 which is synchronized with the change in the movement direction of the headstock 6). The drive current command (for example, each of the eight current values) can be set arbitrarily. The change in the movement direction of the feed member 18 can be detected as a change in the rotation direction of the servo motor 20c itself by an encoder mechanism built into the servo motor 20c. The encoder mechanism can effectively prevent false detection of reverse rotation by setting a small margin, for example, by setting a threshold of "-50rpm" instead of "0rpm" when detecting reverse rotation. Similarly, in subsequent detection of forward rotation, setting a small margin, such as using "+50rpm" as the threshold instead of "0rpm," can effectively prevent false detections.

[0060] (First embodiment) Figure 4 is a graph showing the first embodiment of command current control of the servo motor 20c (drive motor) in this embodiment.

[0061] As shown in Figure 4, in the first embodiment, the driving force of the servo motor 20c is controlled such that, when the headstock 6 begins to move in the reverse direction of the bar stock W, while the movement of the headstock 6 and the movement of the feed member 18 are synchronized by the synchronization device 22, the driving force is smaller than when the headstock 6 is moving in the forward direction of the bar stock W. For example, the command current value when the headstock 6 begins to move in the reverse direction of the bar stock W (e.g., 20mA) is the lowest current value out of 8 levels, and the command current value when the headstock 6 is moving in the forward direction of the bar stock W (e.g., 100mA) is the fourth highest current value out of 8 levels.

[0062] According to this first embodiment, the driving force of the servo motor 20c is reduced when the direction of movement of the headstock 6 is reversed, so that it is possible to effectively suppress the occurrence of a load (axial compressive load) on the bar material W that exceeds the desired range.

[0063] Specifically, when the current command value of the servo motor 20c is uniform, the load on the rod W (axial compressive load) increases as shown in Figure 5(a). However, as shown in Figure 5(b), the load on the rod W (axial compressive load) can be effectively reduced.

[0064] Furthermore, as shown in Figure 4, in the first embodiment, the driving force of the servo motor 20c is controlled such that when the headstock 6 starts moving again in the forward direction of the bar stock W, while the movement of the headstock 6 and the movement of the feed member 18 are synchronized by the synchronization device 22, the driving force of the servo motor 20c is greater than when the headstock 6 is moving in the reverse direction of the bar stock W.

[0065] According to this first embodiment, when the direction of movement of the headstock 6 returns to its original direction, the driving force of the servo motor 20c is increased (returned to its original position in this embodiment), so that it can smoothly follow the forward movement of the headstock 6 or the forward movement of the stopper part S, and the bar stock W can be stably fed to the bar stock processing machine 2.

[0066] In the first embodiment described above, when changing the command current value to the servo motor 20c, a smooth command current value change control, as shown by the dashed line in Figure 4, may be adopted by interposing, for example, a first-order lag filter (not shown). The time constant of the first-order lag filter can be, for example, about 30 milliseconds.

[0067] (Second example) Figure 6 is a graph showing a second embodiment of command current control of the servo motor 20c (drive motor) in this embodiment.

[0068] As shown in Figure 6, in the second embodiment, the driving force of the servo motor 20c is controlled such that, under conditions where the movement of the headstock 6 and the movement of the feed member 18 are synchronized by the synchronization device 22, the driving force of the servo motor 20c is smaller than the driving force when the headstock 6 is moving in the forward direction of the bar stock W when a predetermined time has elapsed since the headstock 6 began moving in the reverse direction of the bar stock W (preferably this setting can be changed, and is preferably about 20 milliseconds). For example, the command current value (e.g., 20mA) when a predetermined time has elapsed since the headstock 6 began moving in the reverse direction of the bar stock W is the lowest current value out of 8 levels, and the command current value (e.g., 100mA) when the headstock 6 is moving in the forward direction of the bar stock W is the fourth highest current value out of 8 levels.

[0069] According to this second embodiment, the driving force of the servo motor 20c is reduced at a predetermined time after the direction of movement of the headstock 6 is reversed. This effectively suppresses the occurrence of a load (axial compressive load) on the bar material W that exceeds the desired range, while also reducing the frequency of changes in the control mode of the servo motor 20c compared to the first embodiment, thereby reducing the risk of failure.

[0070] Furthermore, as shown in Figure 6, in the second embodiment, the driving force of the servo motor 20c is controlled such that, while the movement of the headstock 6 and the movement of the feed member 18 are synchronized by the synchronization device 22, the driving force of the servo motor 20c is greater than when the headstock 6 is moving in the reverse direction of the bar stock W when a predetermined time (preferably adjustable, for example, about 20 milliseconds) has elapsed since the headstock 6 began moving in the forward direction of the bar stock W again.

[0071] According to this second embodiment, the driving force of the servo motor 20c is increased (returned to its original position in this embodiment) at a predetermined time after the movement direction of the headstock 6 begins to return to its original direction. This effectively suppresses the occurrence of a load (axial load) exceeding the desired range on the bar material W, while also reducing the frequency of changes in the control mode of the servo motor 20c compared to the first embodiment, thereby reducing the risk of failure.

[0072] In the second embodiment described above, when changing the command current value to the servo motor 20c, a smooth command current value change control, as shown by the dashed line in Figure 6, may be adopted by interposing, for example, a first-order lag filter (not shown). The time constant of the first-order lag filter can be, for example, about 30 milliseconds.

[0073] (Third embodiment) Figure 7 is a graph showing a third embodiment of command current control of the servo motor 20c (drive motor) in this embodiment.

[0074] As shown in Figure 7, in the third embodiment, the driving force of the servo motor 20c is controlled such that, when the headstock 6 begins to move in the reverse direction of the bar stock W, while the movement of the headstock 6 and the movement of the feed member 18 are synchronized by the synchronization device 22, the driving force is smaller than when the headstock 6 is moving in the forward direction of the bar stock W, and after a predetermined time (preferably adjustable, for example, about 20 milliseconds) has elapsed since the headstock 6 began to move in the reverse direction of the bar stock W, the driving force is even smaller than when the headstock 6 began to move in the reverse direction of the bar stock W. For example, the command current value when the headstock 6 begins to move in the reverse direction of the bar stock W (e.g., 80mA) is the third lowest current value out of eight levels; the command current value when a predetermined time has elapsed since the headstock 6 began to move in the reverse direction of the bar stock W (e.g., 20mA) is the lowest current value out of eight levels; and the command current value when the headstock 6 is moving in the forward direction of the bar stock W (e.g., 100mA) is the fourth highest current value out of eight levels.

[0075] According to this third embodiment, the driving force of the servo motor 20c is reduced in two stages at the timing when the direction of movement of the headstock 6 is reversed and at the timing when a predetermined time has elapsed since the direction of movement of the headstock 6 was reversed. This makes it possible to more effectively suppress the occurrence of a load (axial compressive load) on the bar stock W that exceeds the desired range, and also improves the ability to follow the rise of rotation to the forward direction when the rotation returns to the forward direction again while the driving force is being reduced in one stage.

[0076] Furthermore, as shown in Figure 7, in the third embodiment, the driving force of the servo motor 20c is controlled such that, when the headstock 6 starts moving again in the forward direction of the bar stock W, while the movement of the headstock 6 and the movement of the feed member 18 are synchronized by the synchronization device 22, the driving force is greater when the headstock 6 starts moving again in the forward direction of the bar stock W than when the headstock 6 is moving in the reverse direction of the bar stock W, and after a predetermined time has elapsed since the headstock 6 started moving again in the forward direction of the bar stock W, the driving force is even greater than when the headstock 6 started moving again in the forward direction of the bar stock W.

[0077] According to this third embodiment, the driving force of the servo motor 20c is increased in two stages (returned to its original position in this embodiment) at the timing when the direction of movement of the headstock 6 returns to its original direction, and at the timing when a predetermined time has elapsed since the direction of movement of the headstock 6 returned to its original direction. This effectively suppresses the occurrence of a load (axial compressive load) exceeding the desired range on the bar stock W, while stably feeding the bar stock W to the bar stock processing machine 2. Furthermore, when the direction of movement returns to the reverse direction again while the driving force is being increased in one stage, the responsiveness to torque reduction can be improved.

[0078] In the third embodiment described above, when changing the command current value to the servo motor 20c, a smooth command current value change control, as shown by the dashed line in Figure 7, may be adopted by interposing, for example, a first-order lag filter (not shown). The time constant of the first-order lag filter can be, for example, about 30 milliseconds.

[0079] (Fourth embodiment) Figure 8 is a graph showing a fourth embodiment of command current control of the servo motor 20c (drive motor) in this embodiment.

[0080] As shown in Figure 8, in the fourth embodiment, similar to the third embodiment, the driving force of the servo motor 20c is controlled such that, when the headstock 6 begins to move in the reverse direction of the bar stock W, it is smaller than when the headstock 6 is moving in the forward direction of the bar stock W, and after a predetermined time (preferably adjustable, for example, about 20 milliseconds) has elapsed since the headstock 6 began to move in the reverse direction of the bar stock W, it is even smaller than when the headstock 6 began to move in the reverse direction of the bar stock W. For example, the command current value when the headstock 6 begins to move in the reverse direction of the bar stock W (e.g., 80mA) is the third lowest current value out of eight levels; the command current value when a predetermined time has elapsed since the headstock 6 began to move in the reverse direction of the bar stock W (e.g., 20mA) is the lowest current value out of eight levels; and the command current value when the headstock 6 is moving in the forward direction of the bar stock W (e.g., 100mA) is the fourth highest current value out of eight levels.

[0081] Similar to the third embodiment, the driving force of the servo motor 20c is reduced in two stages at the timing when the direction of movement of the headstock 6 is reversed and at the timing when a predetermined time has elapsed since the direction of movement of the headstock 6 was reversed. This makes it possible to more effectively suppress the occurrence of a load (axial compressive load) on the bar stock W that exceeds the desired range, and also improves the ability to follow the rise of rotation to the forward direction when the rotation returns to the forward direction again while the driving force is being reduced in one stage.

[0082] Then, as shown in Figure 8, in the fourth embodiment, the driving force of the servo motor 20c is controlled such that, when the headstock 6 starts moving again in the forward direction of the bar stock W, while the movement of the headstock 6 and the movement of the feed member 18 are synchronized by the synchronization device 22, the driving force is greater than when the headstock 6 was moving in the forward direction of the bar stock W, and less than when the headstock 6 started moving again in the forward direction of the bar stock W, after a predetermined time has elapsed since the headstock 6 started moving again in the forward direction of the bar stock W.

[0083] According to this fourth embodiment, the driving force of the servo motor 20c is set in two stages: at the timing when the direction of movement of the headstock 6 returns to its original direction, and at the timing when a predetermined time has elapsed since the direction of movement of the headstock 6 returned to its original direction. The change in driving force at the former timing allows the servo motor 20c to follow the forward movement of the headstock 6 more quickly (preferably instantaneously), and the change in driving force at the latter timing allows it to return to the original driving force.

[0084] In the fourth embodiment described above, when changing the command current value to the servo motor 20c, a smooth command current value change control, as shown by the dashed line in Figure 8, may be adopted by interposing, for example, a first-order lag filter (not shown). The time constant of the first-order lag filter can be, for example, about 30 milliseconds.

[0085] (Variations in detecting the movement direction of the headstock 6 and / or the movement direction of the feed member 18) In the embodiments described above (each embodiment), the rotational direction of the servo motor 20c itself is detected and used as the direction of movement of the headstock 6. Strictly speaking, this should be said to be detecting the direction of movement of the feed member 18, not the direction of movement of the headstock 6, but at least at the time of filing this application, there is no need to clearly distinguish between the two in the embodiments, and it is sufficient that the driving force of the servo motor 20c is controlled based on the detection information of either of the two.

[0086] For example, a magnetic scaler or the like may be installed in conjunction with the headstock 6 to directly detect (measure) the direction of movement of the headstock 6. Alternatively, a method may be adopted in which the direction of movement of the headstock 6 is determined in advance based on a program applied to the movement control of the headstock 6.

[0087] On the other hand, the method for detecting (measuring) the direction of movement of the feed member 18 is not limited to the embodiment described above, at least as of the time of filing this application. For example, a magnetic scaler or the like may be installed in conjunction with the feed member 18 for detection (measurement).

[0088] Furthermore, the rotational direction of the synchronization clutch 22e of the synchronization device 20 may be detected (measured) as the direction of movement of the headstock 6 and / or the feed member 18.

[0089] (Modified version without the synchronization device 20) The command current value change control in each of the embodiments described above is also effective in bar stock processing systems that do not have a synchronization device. In bar stock processing systems that do not have a synchronization device, the bar stock itself acts as an intermediary, transmitting the movement of the headstock to the feed member side, causing the feed member to move in conjunction. Even in such cases, the command current value change control in each of the embodiments described above is effective.

[0090] Figure 9 is a side view of a bar stock processing system without a synchronization device. Except for the absence of the synchronization device 20, the other configurations are the same as those of the bar stock processing system in the embodiment shown in Figure 1. In Figure 9, the same reference numerals are used for components similar to those in the embodiment shown in Figure 1, and their detailed descriptions are omitted.

[0091] (Example 1 (2)) Even in bar stock processing systems that do not have a synchronization device, the application of command current control of the servo motor 20c (drive motor) shown in Figure 4 is effective (First Embodiment).

[0092] In this case, the driving force of the servo motor 20c is controlled such that, when the headstock 6 begins to move in the reverse direction of the bar stock W, while the movement of the headstock 6 is transmitted by the bar stock W as the movement of the feed member 18, the driving force is smaller than when the headstock 6 is moving in the forward direction of the bar stock W. For example, the command current value when the headstock 6 begins to move in the reverse direction of the bar stock W (e.g., 20mA) is the lowest current value out of 8 levels, and the command current value when the headstock 6 is moving in the forward direction of the bar stock W (e.g., 100mA) is the fourth highest current value out of 8 levels.

[0093] According to this first embodiment, the driving force of the servo motor 20c is reduced when the direction of movement of the headstock 6 is reversed, so that it is possible to effectively suppress the occurrence of a load (axial compressive load) on the bar material W that exceeds the desired range.

[0094] Specifically, when the current command value of the servo motor 20c is uniform, the load on the rod W (axial compressive load) increases as shown in Figure 5(a). However, as shown in Figure 5(b), the load on the rod W (axial compressive load) can be effectively reduced.

[0095] Furthermore, in this case, the driving force of the servo motor 20c is controlled such that when the headstock 6 starts moving again in the forward direction of the bar stock W, while the movement of the headstock 6 is being transmitted by the bar stock W as the movement of the feed member 18, the driving force is greater than when the headstock 6 is moving in the reverse direction of the bar stock W.

[0096] According to this first embodiment, when the direction of movement of the headstock 6 returns to its original direction, the driving force of the servo motor 20c is increased (returned to its original position in this embodiment), so that it can smoothly follow the forward movement of the headstock 6 and stably feed the bar stock W to the bar stock processing machine 2.

[0097] In this case as well, when changing the command current value to the servo motor 20c, a smooth command current value change control, as shown by the dashed line in Figure 4, may be adopted by interposing, for example, a first-order lag filter (not shown). The time constant of the first-order lag filter can be set to, for example, about 30 milliseconds.

[0098] (Second Example (2)) Even in bar stock processing systems that do not have a synchronization device, the application of command current control of the servo motor 20c (drive motor) shown in Figure 6 is effective (second embodiment).

[0099] In this case, the driving force of the servo motor 20c is controlled such that, when the movement of the headstock 6 is transmitted by the rod stock W as the movement of the feed member 18, the driving force of the servo motor 20c is smaller than when the headstock 6 is moving in the forward direction of the rod stock W when a predetermined time (preferably adjustable, for example, about 20 milliseconds) has elapsed since the headstock 6 began moving in the reverse direction of the rod stock W. For example, the command current value (e.g., 20mA) when a predetermined time has elapsed since the headstock 6 began moving in the reverse direction of the rod stock W is the lowest current value out of 8 levels, and the command current value (e.g., 100mA) when the headstock 6 is moving in the forward direction of the rod stock W is the fourth highest current value out of 8 levels.

[0100] According to this second embodiment, the driving force of the servo motor 20c is reduced at a predetermined time after the direction of movement of the headstock 6 is reversed. This effectively suppresses the occurrence of a load (axial compressive load) on the bar material W that exceeds the desired range, while also reducing the frequency of changes in the control mode of the servo motor 20c compared to the first embodiment, thereby reducing the risk of failure.

[0101] Furthermore, in this case, the driving force of the servo motor 20c is controlled to be greater than when the headstock 6 is moving in the reverse direction of the bar stock W when a predetermined time (preferably adjustable, for example, about 20 milliseconds) has elapsed since the headstock 6 began moving again in the forward direction of the bar stock W, while the movement of the headstock 6 is being transmitted by the bar stock W as the movement of the feed member 18.

[0102] According to this second embodiment, the driving force of the servo motor 20c is increased (returned to its original position in this embodiment) at a predetermined time after the movement direction of the headstock 6 begins to return to its original direction. This effectively suppresses the occurrence of a load (axial load) exceeding the desired range on the bar material W, while also reducing the frequency of changes in the control mode of the servo motor 20c compared to the first embodiment, thereby reducing the risk of failure.

[0103] In this case as well, when changing the command current value to the servo motor 20c, a smooth command current value change control, as shown by the dashed line in Figure 6, may be adopted by interposing, for example, a first-order lag filter (not shown). The time constant of the first-order lag filter can be set to, for example, about 30 milliseconds.

[0104] (Third Example (2)) Even in bar stock processing systems that do not have a synchronization device, the application of command current control of the servo motor 20c (drive motor) shown in Figure 7 is effective (third embodiment).

[0105] In this case, the driving force of the servo motor 20c is controlled such that, when the headstock 6 begins to move in the reverse direction of the bar stock W, while the movement of the headstock 6 is transmitted by the bar stock W as the movement of the feed member 18, the driving force is smaller than when the headstock 6 is moving in the forward direction of the bar stock W, and after a predetermined time (preferably adjustable, for example, about 20 milliseconds) has elapsed since the headstock 6 began to move in the reverse direction of the bar stock W, the driving force is even smaller than when the headstock 6 began to move in the reverse direction of the bar stock W. For example, the command current value when the headstock 6 begins to move in the reverse direction of the bar stock W (e.g., 80mA) is the third lowest current value out of eight levels; the command current value when a predetermined time has elapsed since the headstock 6 began to move in the reverse direction of the bar stock W (e.g., 20mA) is the lowest current value out of eight levels; and the command current value when the headstock 6 is moving in the forward direction of the bar stock W (e.g., 100mA) is the fourth highest current value out of eight levels.

[0106] According to this third embodiment, the driving force of the servo motor 20c is reduced in two stages at the timing when the direction of movement of the headstock 6 is reversed and at the timing when a predetermined time has elapsed since the direction of movement of the headstock 6 was reversed. This makes it possible to more effectively suppress the occurrence of a load (axial compressive load) on the bar stock W that exceeds the desired range, and also improves the ability to follow the rise of rotation to the forward direction when the rotation returns to the forward direction again while the driving force is being reduced in one stage.

[0107] Furthermore, in this case, the driving force of the servo motor 20c is controlled such that, when the headstock 6 starts moving again in the forward direction of the bar stock W while the movement of the headstock 6 is transmitted by the bar stock W as the movement of the feed member 18, the driving force is greater than when the headstock 6 is moving in the reverse direction of the bar stock W, and after a predetermined time has elapsed since the headstock 6 started moving again in the forward direction of the bar stock W, the driving force is even greater than when the headstock 6 started moving again in the forward direction of the bar stock W.

[0108] According to this third embodiment, the driving force of the servo motor 20c is increased in two stages (returned to its original position in this embodiment) at the timing when the direction of movement of the headstock 6 returns to its original direction, and at the timing when a predetermined time has elapsed since the direction of movement of the headstock 6 returned to its original direction. This effectively suppresses the occurrence of a load (axial load) exceeding the desired range on the bar stock W, while stably feeding the bar stock W to the bar stock processing machine 2. Furthermore, when the direction of movement returns to the reverse direction again while the driving force is being increased in one stage, the responsiveness to torque reduction can be improved.

[0109] In this case as well, when changing the command current value to the servo motor 20c, a smooth command current value change control, as shown by the dashed line in Figure 7, may be adopted by interposing, for example, a first-order lag filter (not shown). The time constant of the first-order lag filter can be set to, for example, about 30 milliseconds.

[0110] (Fourth Example (2)) Even in bar stock processing systems that do not have a synchronization device, the application of command current control of the servo motor 20c (drive motor) shown in Figure 8 is effective (Fourth Embodiment).

[0111] In this case, the driving force of the servo motor 20c is controlled such that, when the headstock 6 begins to move in the reverse direction of the bar stock W, while the movement of the headstock 6 is transmitted by the bar stock W as the movement of the feed member 18, the driving force is smaller than when the headstock 6 is moving in the forward direction of the bar stock W, and after a predetermined time (preferably adjustable, for example, about 20 milliseconds) has elapsed since the headstock 6 began to move in the reverse direction of the bar stock W, the driving force is even smaller than when the headstock 6 began to move in the reverse direction of the bar stock W. For example, the command current value when the headstock 6 begins to move in the reverse direction of the bar stock W (e.g., 80mA) is the third lowest current value out of eight levels; the command current value when a predetermined time has elapsed since the headstock 6 began to move in the reverse direction of the bar stock W (e.g., 20mA) is the lowest current value out of eight levels; and the command current value when the headstock 6 is moving in the forward direction of the bar stock W (e.g., 100mA) is the fourth highest current value out of eight levels.

[0112] According to this fourth embodiment, the driving force of the servo motor 20c is reduced in two stages at the timing when the direction of movement of the headstock 6 is reversed and at the timing when a predetermined time has elapsed since the direction of movement of the headstock 6 was reversed. This makes it possible to more effectively suppress the occurrence of a load (axial compressive load) on the bar stock W that exceeds the desired range, and also improves the ability to follow the rise of rotation to the forward direction when the rotation returns to the forward direction again while the driving force is being reduced by one stage.

[0113] Furthermore, in the fourth embodiment, the driving force of the servo motor 20c is controlled such that, when the headstock 6 starts moving again in the forward direction of the bar stock W while the movement of the headstock 6 is transmitted by the bar stock W as the movement of the feed member 18, the driving force is greater than when the headstock 6 is moving in the forward direction of the bar stock W, and when a predetermined time has elapsed since the headstock 6 started moving again in the forward direction of the bar stock W, the driving force is less than when the headstock 6 started moving again in the forward direction of the bar stock W.

[0114] According to this fourth embodiment, the driving force of the servo motor 20c is set in two stages: at the timing when the direction of movement of the headstock 6 returns to its original direction, and at the timing when a predetermined time has elapsed since the direction of movement of the headstock 6 returned to its original direction. The change in driving force at the former timing allows the servo motor 20c to follow the forward movement of the headstock 6 more quickly (preferably instantaneously), and the change in driving force at the latter timing allows it to return to the original driving force.

[0115] In this case as well, when changing the command current value to the servo motor 20c, a smooth command current value change control, as shown by the dashed line in Figure 8, may be adopted by interposing, for example, a first-order lag filter (not shown). The time constant of the first-order lag filter can be set to, for example, about 30 milliseconds.

[0116] (A modified version in which the spindle head does not move) The command current value change control in each of the embodiments described above is also effective when positioning a bar stock W by bringing its tip into contact with a stopper part S (see Figure 10) in a bar stock machining system where the headstock does not move (illustrations are omitted; this includes cases where the bar stock machining system described above is used in a manner in which the headstock does not move). (The stopper part S is located on the movement path of the bar stock W when positioning the bar stock W, but moves away from the movement path once the bar stock W has been positioned.)

[0117] (First Example (3)) Even when the headstock does not move, the command current control of the servo motor 20c (drive motor) shown in Figure 4 is effective (first embodiment).

[0118] In this case, the driving force of the servo motor 20c is controlled such that when the headstock 6 begins to move in the reverse direction of the bar stock W, while the resistance force received from the stopper part S after the tip of the bar stock W reaches the stopper part S is transmitted to the feed member 18 by the bar stock W, the driving force is smaller than when the headstock 6 is moving in the forward direction of the bar stock W. For example, the command current value when the headstock 6 begins to move in the reverse direction of the bar stock W (e.g., 20mA) is the lowest current value out of 8 levels, and the command current value when the headstock 6 is moving in the forward direction of the bar stock W (e.g., 100mA) is the fourth highest current value out of 8 levels.

[0119] According to this first embodiment, the driving force of the servo motor 20c is reduced when the direction of movement of the headstock 6 is reversed, so that it is possible to effectively suppress the occurrence of a load (axial compressive load) on the bar material W that exceeds the desired range.

[0120] Specifically, when the current command value of the servo motor 20c is uniform, the load on the rod W (axial compressive load) increases as shown in Figure 5(a). However, as shown in Figure 5(b), the load on the rod W (axial compressive load) can be effectively reduced.

[0121] Furthermore, in this case, the driving force of the servo motor 20c is controlled such that when the headstock 6 starts moving again in the forward direction of the rod W, after the tip of the rod W has reached the stopper part S and the resistance force received from the stopper part S is transmitted to the feed member 18 by the rod W, the driving force of the servo motor 20c is greater than when the headstock 6 is moving in the reverse direction of the rod W.

[0122] According to this first embodiment, when the direction of movement of the headstock 6 returns to its original direction, the driving force of the servo motor 20c is increased (returned to its original position in this embodiment), so that it can smoothly follow the forward movement of the headstock 6 and stably feed the bar stock W to the bar stock processing machine 2.

[0123] In this case as well, when changing the command current value to the servo motor 20c, a smooth command current value change control, as shown by the dashed line in Figure 4, may be adopted by interposing, for example, a first-order lag filter (not shown). The time constant of the first-order lag filter can be set to, for example, about 30 milliseconds.

[0124] (Second Example (3)) Even when the headstock does not move, the application of command current control for the servo motor 20c (drive motor) shown in Figure 6 is effective (second embodiment).

[0125] In this case, the driving force of the servo motor 20c is controlled to be smaller than when the headstock 6 is moving in the forward direction of the bar stock W when a predetermined time (preferably adjustable, for example, about 20 milliseconds) has elapsed since the headstock 6 began moving in the reverse direction of the bar stock W, under the condition that the resistance force received from the stopper part S after the tip of the bar stock W reaches the stopper part S is transmitted to the feed member 18 by the bar stock W. For example, the command current value (e.g., 20mA) when a predetermined time has elapsed since the headstock 6 began moving in the reverse direction of the bar stock W is the lowest current value out of 8 levels, and the command current value (e.g., 100mA) when the headstock 6 is moving in the forward direction of the bar stock W is the fourth highest current value out of 8 levels.

[0126] According to this second embodiment, the driving force of the servo motor 20c is reduced at a predetermined time after the direction of movement of the headstock 6 is reversed. This effectively suppresses the occurrence of a load (axial compressive load) on the bar material W that exceeds the desired range, while also reducing the frequency of changes in the control mode of the servo motor 20c compared to the first embodiment, thereby reducing the risk of failure.

[0127] Furthermore, in this case, the driving force of the servo motor 20c is controlled to be greater than when the headstock 6 is moving in the reverse direction of the rod W when a predetermined time (preferably adjustable, for example, about 20 milliseconds) has elapsed since the headstock 6 began moving again in the forward direction of the rod W, while the resistance force received from the stopper part S after the tip of the rod W reaches the stopper part S is transmitted to the feed member 18 by the rod W.

[0128] According to this second embodiment, the driving force of the servo motor 20c is increased (returned to its original position in this embodiment) at a predetermined time after the movement direction of the headstock 6 begins to return to its original direction. This effectively suppresses the occurrence of a load (axial compressive load) exceeding the desired range on the bar material W, while also reducing the frequency of changes in the control mode of the servo motor 20c compared to the first embodiment, thereby reducing the risk of failure.

[0129] In this case as well, when changing the command current value to the servo motor 20c, a smooth command current value change control, as shown by the dashed line in Figure 6, may be adopted by interposing, for example, a first-order lag filter (not shown). The time constant of the first-order lag filter can be set to, for example, about 30 milliseconds.

[0130] (Third Example (3)) Even when the headstock does not move, the application of command current control for the servo motor 20c (drive motor) shown in Figure 7 is effective (third embodiment).

[0131] In this case, the driving force of the servo motor 20c is controlled such that, when the headstock 6 begins to move in the reverse direction of the bar stock W while the resistance force received from the stopper portion S after the tip of the bar stock W reaches the stopper portion S is transmitted to the feed member 18 by the bar stock W, the driving force is smaller than when the headstock 6 is moving in the forward direction of the bar stock W, and after a predetermined time (preferably adjustable, preferably about 20 milliseconds) has elapsed since the headstock 6 began to move in the reverse direction of the bar stock W, the driving force is even smaller than when the headstock 6 began to move in the reverse direction of the bar stock W. For example, the command current value when the headstock 6 begins to move in the reverse direction of the bar stock W (e.g., 80mA) is the third lowest current value out of eight levels; the command current value when a predetermined time has elapsed since the headstock 6 began to move in the reverse direction of the bar stock W (e.g., 20mA) is the lowest current value out of eight levels; and the command current value when the headstock 6 is moving in the forward direction of the bar stock W (e.g., 100mA) is the fourth highest current value out of eight levels.

[0132] According to this third embodiment, the driving force of the servo motor 20c is reduced in two stages at the timing when the direction of movement of the headstock 6 is reversed and at the timing when a predetermined time has elapsed since the direction of movement of the headstock 6 was reversed. This makes it possible to more effectively suppress the occurrence of a load (axial compressive load) on the bar stock W that exceeds the desired range, and also improves the ability to follow the rise of rotation to the forward direction when the rotation returns to the forward direction again while the driving force is being reduced in one stage.

[0133] Furthermore, in this case, the driving force of the servo motor 20c is controlled such that when the headstock 6 starts moving again in the forward direction of the bar stock W while the resistance force received from the stopper part S after the tip of the bar stock W has reached the stopper part S is transmitted to the feed member 18 by the bar stock W, the driving force is greater than when the headstock 6 is moving in the reverse direction of the bar stock W, and when a predetermined time has elapsed since the headstock 6 started moving again in the forward direction of the bar stock W, the driving force is even greater than when the headstock 6 started moving again in the forward direction of the bar stock W.

[0134] According to this third embodiment, the driving force of the servo motor 20c is increased in two stages (returned to its original position in this embodiment) at the timing when the direction of movement of the headstock 6 returns to its original direction, and at the timing when a predetermined time has elapsed since the direction of movement of the headstock 6 returned to its original direction. This effectively suppresses the occurrence of a load (axial compressive load) exceeding the desired range on the bar stock W, while stably feeding the bar stock W to the bar stock processing machine 2. Furthermore, when the direction of movement returns to the reverse direction again while the driving force is being increased in one stage, the responsiveness to torque reduction can be improved.

[0135] In this case as well, when changing the command current value to the servo motor 20c, a smooth command current value change control, as shown by the dashed line in Figure 7, may be adopted by interposing, for example, a first-order lag filter (not shown). The time constant of the first-order lag filter can be set to, for example, about 30 milliseconds.

[0136] (Fourth Example (3)) Even when the headstock does not move, the application of command current control for the servo motor 20c (drive motor) shown in Figure 8 is effective (Fourth Embodiment).

[0137] In this case, the driving force of the servo motor 20c is controlled such that, when the headstock 6 begins to move in the reverse direction of the bar stock W while the resistance force received from the stopper portion S after the tip of the bar stock W reaches the stopper portion S is transmitted to the feed member 18 by the bar stock W, the driving force is smaller than when the headstock 6 is moving in the forward direction of the bar stock W, and after a predetermined time (preferably adjustable, preferably about 20 milliseconds) has elapsed since the headstock 6 began to move in the reverse direction of the bar stock W, the driving force is even smaller than when the headstock 6 began to move in the reverse direction of the bar stock W. For example, the command current value when the headstock 6 begins to move in the reverse direction of the bar stock W (e.g., 80mA) is the third lowest current value out of eight levels; the command current value when a predetermined time has elapsed since the headstock 6 began to move in the reverse direction of the bar stock W (e.g., 20mA) is the lowest current value out of eight levels; and the command current value when the headstock 6 is moving in the forward direction of the bar stock W (e.g., 100mA) is the fourth highest current value out of eight levels.

[0138] According to this fourth embodiment, the driving force of the servo motor 20c is reduced in two stages at the timing when the direction of movement of the headstock 6 is reversed and at the timing when a predetermined time has elapsed since the direction of movement of the headstock 6 was reversed. This makes it possible to more effectively suppress the occurrence of a load (axial compressive load) on the bar stock W that exceeds the desired range, and also improves the ability to follow the rise of rotation to the forward direction when the rotation returns to the forward direction again while the driving force is being reduced by one stage.

[0139] Furthermore, in the fourth embodiment, the driving force of the servo motor 20c is controlled such that when the headstock 6 starts moving again in the forward direction of the bar stock W while the resistance force received from the stopper portion S after the tip of the bar stock W has reached the stopper portion S is transmitted to the feed member 18 by the bar stock W, the driving force is greater than when the headstock 6 is moving in the forward direction of the bar stock W, and when a predetermined time has elapsed since the headstock 6 started moving again in the forward direction of the bar stock W, the driving force is less than when the headstock 6 started moving again in the forward direction of the bar stock W.

[0140] According to this fourth embodiment, the driving force of the servo motor 20c is set in two stages: at the timing when the direction of movement of the headstock 6 returns to its original direction, and at the timing when a predetermined time has elapsed since the direction of movement of the headstock 6 returned to its original direction. The change in driving force at the former timing allows the servo motor 20c to follow the forward movement of the headstock 6 more quickly (preferably instantaneously), and the change in driving force at the latter timing allows it to return to the original driving force.

[0141] In this case as well, when changing the command current value to the servo motor 20c, a smooth command current value change control, as shown by the dashed line in Figure 8, may be adopted by interposing, for example, a first-order lag filter (not shown). The time constant of the first-order lag filter can be set to, for example, about 30 milliseconds. [Explanation of Symbols]

[0142] 1. Bar stock processing system 2 Bar processing machine 4 Bar feeder 6 Headstock 8 main axis 10 Collet Chucks 12 Guide bush 14 Cutting bite 16 Guide rails 18 Feed member 18a Pressing member body 18b Bar holding part 18th century feather 20 Feed Member Drive Device 20a sprocket 20b Endless chain 20c servo motor (drive motor) 22 Synchronizing device 22a Connecting plate 22b Connecting rod 22c sprocket 22d endless chain 22e Synchronized Clutch 24 Control Unit 26. Leftover material box section 106 Headstock 112 Feed member 120 Feed member interlocking rotating body 122 Endless chain for feeder 130 Clutch mechanism 148 Headstock Interlocking Rotating Body 149 Drive motor 150 Endless chain for headstock

Claims

1. A bar stock processing machine with a moving headstock, A rod feeder that advances a rod by pushing the rear end of the rod with a feeding member, A synchronization device capable of synchronizing the movement of the headstock of the bar processing machine and the movement of the feed member of the bar supply machine in the forward and backward directions of the bar material, Equipped with, The aforementioned bar material feeder has a drive motor capable of providing movement force to the feed member of the bar material feeder, The drive motor is driven and controlled such that, while the movement of the headstock and the movement of the feed member are synchronized by the synchronization device, the magnitude of the moving force is changed in accordance with the change in the direction of movement of the headstock and / or the direction of movement of the feed member, while maintaining the direction of the moving force. A bar material processing system characterized by the following features.

2. A bar stock processing machine with a moving headstock, A rod feeder that advances a rod by pushing the rear end of the rod with a feeding member, Equipped with, The aforementioned bar material feeder has a drive motor capable of providing movement force to the feed member of the bar material feeder, The drive motor is controlled to change the magnitude of the moving force while maintaining the direction of the moving force, in accordance with the change in the direction of movement of the headstock and / or the direction of movement of the feed member, while the movement of the headstock is transmitted as the movement of the feed member by the rod. A bar material processing system characterized by the following features.

3. A bar processing machine having a stopper for positioning the tip of a bar, A rod feeder that advances the rod by pushing the rear end of the rod with a feeding member, Equipped with, The aforementioned bar material feeder has a drive motor capable of providing movement force to the feed member of the bar material feeder, The drive motor is controlled according to the change in the direction of movement of the feed member, while the resistance force received from the stopper portion after the tip of the rod reaches the stopper portion is transmitted to the feed member by the rod. A bar material processing system characterized by the following features.

4. The driving force of the drive motor is smaller when the headstock and / or the feed member begin to move in the reverse direction of the rod than when the headstock and / or the feed member is moving in the forward direction of the rod. The bar processing system according to claim 1 or 2, characterized by the features described above.

5. The driving force of the drive motor is smaller when a predetermined time has elapsed since the headstock and / or the feed member began moving in the reverse direction of the rod, than when the headstock and / or the feed member was moving in the forward direction of the rod. The bar processing system according to claim 1 or 2, characterized by the features described above.

6. The driving force of the aforementioned drive motor is When the headstock and / or the feed member begin to move in the backward direction of the rod, the movement is smaller than when the headstock and / or the feed member is moving in the forward direction of the rod. When a predetermined time has elapsed since the headstock and / or the feed member began moving in the reverse direction of the rod, the time is even smaller than when the headstock and / or the feed member began moving in the reverse direction of the rod. The bar processing system according to claim 1 or 2, characterized by the features described above.

7. The driving force of the drive motor is greater when the headstock and / or the feed member begin moving again in the forward direction of the rod than when the headstock and / or the feed member is moving in the reverse direction of the rod. The bar processing system according to claim 1 or 2, characterized by the features described above.

8. The driving force of the drive motor is greater when a predetermined time has elapsed since the headstock and / or the feed member began moving again in the forward direction of the rod, than when the headstock and / or the feed member was moving in the reverse direction of the rod. The bar processing system according to claim 1 or 2, characterized by the features described above.

9. The driving force of the aforementioned drive motor is When the headstock and / or the feed member begin to move again in the forward direction of the rod, the movement is greater than when the headstock and / or the feed member is moving in the reverse direction of the rod. When a predetermined time has elapsed since the headstock and / or the feed member began moving again in the forward direction of the rod, the time is greater than when the headstock and / or the feed member began moving again in the forward direction of the rod. The bar processing system according to claim 1 or 2, characterized by the features described above.

10. The driving force of the aforementioned drive motor is When the headstock and / or the feed member begin to move again in the forward direction of the rod, the movement is greater than when the headstock and / or the feed member is moving in the reverse direction of the rod. When a predetermined time has elapsed since the headstock and / or the feed member began moving again in the forward direction of the rod, the time elapsed is smaller than the time when the headstock and / or the feed member began moving again in the forward direction of the rod. The bar processing system according to claim 1 or 2, characterized by the features described above.

11. The aforementioned drive motor is controlled based on a drive current command. The value of the drive current command is configured to switch according to each of the multiple states. The value of the drive current command corresponding to each of the aforementioned multiple states can be set arbitrarily. A bar material processing system according to any one of claims 1 to 3.

12. The change in the movement direction of the headstock and / or the movement direction of the feed member is detected by the rotation of the encoder mechanism. The threshold for determining the change in rotation direction based on the rotation of the encoder mechanism can be set arbitrarily. The bar processing system according to claim 1 or 2, characterized by the features described above.

13. The driving force of the drive motor is smaller when the feed member begins to move in the reverse direction of the rod than when the feed member is moving in the forward direction of the rod. The bar material processing system according to feature 3.

14. The driving force of the drive motor is smaller when a predetermined time has elapsed since the feed member began moving in the reverse direction of the rod than when the feed member was moving in the forward direction of the rod. The bar material processing system according to feature 3.

15. The driving force of the aforementioned drive motor is When the feed member begins to move in the backward direction of the rod, the amount of movement is smaller than when the feed member is moving in the forward direction of the rod. When a predetermined time has elapsed since the feed member began moving in the reverse direction of the rod, the time is even smaller than when the feed member began moving in the reverse direction of the rod. The bar material processing system according to feature 3.

16. The driving force of the drive motor is greater when the feed member starts moving again in the forward direction of the rod than when the feed member is moving in the reverse direction of the rod. The bar material processing system according to feature 3.

17. The driving force of the drive motor is greater when a predetermined time has elapsed since the feed member began moving again in the forward direction of the rod, than when the feed member was moving in the reverse direction of the rod. The bar material processing system according to feature 3.

18. The driving force of the aforementioned drive motor is When the feed member begins to move again in the forward direction of the rod, the movement is greater than when the feed member was moving in the reverse direction of the rod. When a predetermined time has elapsed since the feed member began moving again in the forward direction of the rod, the time is even greater than when the feed member began moving again in the forward direction of the rod. The bar material processing system according to feature 3.

19. The driving force of the aforementioned drive motor is When the feed member begins to move again in the forward direction of the rod, the movement is greater than when the feed member was moving in the reverse direction of the rod. When a predetermined time has elapsed since the feed member began moving again in the forward direction of the rod, the time elapsed is smaller than when the feed member began moving again in the forward direction of the rod. The bar material processing system according to feature 3.

20. The change in the direction of movement of the feed member is detected by the rotation of the encoder mechanism. The threshold for determining the change in rotation direction based on the rotation of the encoder mechanism can be set arbitrarily. The bar material processing system according to feature 3.

21. A bar stock processing machine with a moving headstock, A rod feeder that advances a rod by pushing the rear end of the rod with a feeding member, A synchronization device capable of synchronizing the movement of the headstock of the bar processing machine and the movement of the feed member of the bar supply machine in the forward and backward directions of the bar material, Equipped with, The aforementioned bar material feeder has a drive motor capable of providing movement force to the feed member of the bar material feeder, The drive motor is driven and controlled in accordance with the change in the direction of movement of the headstock and / or the direction of movement of the feed member, while the movement of the headstock and the movement of the feed member are synchronized by the synchronization device. The aforementioned drive motor is controlled based on a drive current command. The value of the drive current command is configured to switch according to each of the multiple states. The value of the drive current command corresponding to each of the aforementioned multiple states can be set arbitrarily. A bar material processing system characterized by the following features.

22. A bar stock processing machine with a moving headstock, A rod feeder that advances a rod by pushing the rear end of the rod with a feeding member, Equipped with, The aforementioned bar material feeder has a drive motor capable of providing movement force to the feed member of the bar material feeder, The drive motor is driven and controlled in accordance with the change in the direction of movement of the headstock and / or the direction of movement of the feed member, while the movement of the headstock is transmitted as the movement of the feed member by the rod. The aforementioned drive motor is controlled based on a drive current command. The value of the drive current command is configured to switch according to each of the multiple states. The value of the drive current command corresponding to each of the aforementioned multiple states can be set arbitrarily. A bar material processing system characterized by the following features.

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