Rod stock machining 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 supplying machine that advances the bar (generally steel or resin material of approximately φ12 or less) by pushing the rear end of the bar with a feeding member. [Background technology]

[0002] Conventionally, there has been known a bar processing system that includes a bar processing machine with a movable headstock (also called a "moving headstock type bar processing machine"), a bar feeder that advances the bar by pushing the rear end of the bar with a feed member (also called a "feed arrow"), and a synchronizing device that can synchronize the movement of the headstock of the bar processing machine with the movement of the feed member of the bar feeder in the forward and reverse directions of the bar.

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

[0004] The bar is fed toward the bar processing machine by the feed member moving forward in accordance with the movement of the endless chain. When the tip of the bar moves to a predetermined position on the bar processing machine (for example, a position determined by a stopper), the bar is gripped by the collet chuck of the bar processing machine. The bar is then processed while the headstock moves back and forth.

[0005] During bar processing, when 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 come out of the finger chuck and so that an excessive load is not applied to the bar. For this purpose, a synchronizing device is provided.

[0006] For example, in Patent Document 1 by the present applicant, there is a configuration including a feed member endless chain 122 supporting a feed member 112, a feed member interlocking rotor 120 that rotates and moves in conjunction with the movement of the feed member endless chain 122, a headstock endless chain 150 connected to a headstock 106, and a headstock interlocking rotor 148 that rotates and moves in conjunction with the movement of the headstock endless chain 150, in which the feed member interlocking rotor 120 and the headstock interlocking rotor 148 are detachably connected by a clutch means 130 (an example of a synchronizing device) (see FIG. 11: a diagram corresponding to FIG. 1 in Patent Document 1). When the clutch means 130 is released, it is possible to move the feed member 112 by a drive motor 149 independently of the movement of the headstock 106 (it is possible to provide a moving force for the feed member 112 independently of the moving force of the headstock 106).

[0007] In addition, Patent Document 2 by the present applicant proposes a configuration for inexpensively and accurately confirming that the diameter of the bar material is appropriate for the collet chuck, based on the configuration shown in Figure 11. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent Publication No. 2001-246502 [Patent Document 2] Patent No. 6784392 Summary of the Invention [Problem to be solved by the invention]

[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 bar feed direction.

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

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

[0012] Here, the inventors of the present invention have found that if the drive current value of the drive motor 149 is set uniformly, when the moving direction of the headstock 106 and / or the moving direction of the feed member 112 are reversed during processing of the bar stock, a load (axial compressive load) exceeding the desired range may be generated on the bar stock (see FIG. 4).

[0013] The present invention has been devised based on the above findings. An object of the present invention is to provide a bar processing system that can significantly prevent an excessive load (axial compressive load) from being applied to the bar, even when the moving direction of the headstock and / or the moving direction of the feed member are reversed during processing of the bar. [Means for solving the problem]

[0014] One aspect of the present invention is a bar processing system comprising a bar processing machine with a movable headstock, a bar stock feeder which advances the bar stock by pushing the rear end of the bar stock with a feed member, and a synchronizing device capable of synchronizing the movement of the headstock of the bar processing machine with the movement of the feed member of the bar stock feeder in the forward and reverse directions of the bar stock, wherein the bar stock feeder has a drive motor capable of providing a moving force to the feed member of the bar stock feeder, and the drive motor is drive controlled in response to 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 the synchronizing device.

[0015] According to this aspect of the present invention, the drive motor is driven and controlled in response to 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 synchronizing device, thereby effectively preventing the occurrence of a load (axial compressive load) on the bar stock that exceeds the desired range.

[0016] The concept of the present invention is also effective in a bar processing system that does not have a synchronizing device. In such a bar processing system, the bar itself acts as an intermediary, and the movement of the headstock is transmitted to the feed member, which then moves in conjunction with the headstock. Even in such a case, the concept of the present invention is effective.

[0017] That is, one aspect of the present invention is a bar processing system comprising a bar processing machine with a movable headstock, and a bar feeder which advances the bar stock by pushing the rear end of the bar stock with a feed member, the bar feeder having a drive motor capable of providing a moving force to the feed member of the bar feeder, and the drive motor is drive controlled in response to changes in the direction of movement of the headstock and / or the direction of movement of the feed member under a state in which the movement of the headstock is transmitted by the bar stock as movement of the feed member.

[0018] According to this aspect of the present invention, the drive motor is controlled in response to 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 is transmitted by the bar itself as movement of the feed member, thereby effectively preventing the occurrence of a load (axial compressive load) on the bar that exceeds the desired range.

[0019] Furthermore, the concept of the present invention can also be effectively utilized for control in positioning the tip of a bar by abutting it against a stopper portion in a bar processing system in which the headstock is stationary.

[0020] That is, one aspect of the present invention is a bar processing system comprising a bar processing machine having a stopper portion for positioning the tip of a bar stock, and a bar stock supplying machine which advances the bar stock by pushing the rear end of the bar stock with a feed member, wherein the bar stock supplying machine has a drive motor capable of providing a moving force to the feed member of the bar stock supplying machine, and the drive motor is driven and controlled in response to a change in the moving direction of the feed member under a state in which the resistance force received from the stopper portion after the tip of the bar stock reaches the stopper portion is transmitted to the feed member by the bar stock.

[0021] According to this aspect of the present invention, the drive motor is controlled in response to changes 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 bar material, thereby effectively preventing the occurrence of a load (axial compressive load) on the bar material that exceeds the desired range.

[0022] Specifically, for example, it is preferable that the driving force of the drive motor is smaller when the headstock and / or the feed member start to move in the backward direction of the bar than when the headstock is moving in the forward direction of the bar under a state in which the movement of the headstock and / or the feed member is synchronized with the movement of the feed member by the synchronizing device, or under a state in which the movement of the headstock is transmitted by the bar as the movement of the feed member, or under a state in which the resistance force received from the stopper portion after the tip of the bar reaches the stopper portion is transmitted to the feed member by 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, so that it is possible to effectively prevent the load (axial compressive load) on the bar that exceeds the desired range. Furthermore, the reduction in driving force means a reduction in power consumption, which contributes to energy conservation and environmental consideration.

[0024] Alternatively, for example, it is preferable that the driving force of the drive motor is smaller when a predetermined time has elapsed since the headstock and / or the feed member start to move in the backward direction of the bar stock than when the headstock and / or the feed member are moving in the forward direction of the bar stock, under a state in which the movement of the headstock and the movement of the feed member are synchronized by the synchronizing device, or under a state in which the movement of the headstock is transmitted as the movement of the feed member by the bar stock, or under a state in which the resistance force received from the stopper portion after the tip of the bar stock reaches the stopper portion is transmitted to the feed member by the bar stock.

[0025] According to this, the driving force of the drive motor is reduced at a timing when a predetermined time has elapsed since the movement direction of the headstock and / or the movement direction of the feed member are reversed, so that it is possible to effectively prevent the load (axial compressive load) on the bar stock from exceeding a desired range while reducing the frequency of drive control of the drive motor, thereby reducing the risk of breakdown. Furthermore, reduced driving force means reduced power consumption, which contributes to energy conservation and environmental consideration.

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

[0027] According to this, the driving force of the drive motor is reduced in two stages 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 since the moving direction of the headstock and / or the moving direction of the feed member was reversed, so that when the forward rotation direction is restored while the driving force is reduced by one stage, it is possible to improve the follow-up to the start of forward rotation. Furthermore, since the reduction in driving force means a reduction in power consumption, it saves energy and contributes to environmental consideration.

[0028] Moreover, each of the above-mentioned inventions can be similarly applied to the case where the moving direction of the headstock and / or the moving direction of the feed member returns to the original direction.

[0029] That is, for example, it is preferable that the driving force of the drive motor is greater when the headstock and / or the feed member start to move again in the forward direction of the bar under a state in which the movement of the headstock and the movement of the feed member are synchronized by the synchronizing device, or under a state in which the movement of the headstock is transmitted by the bar as movement of the feed member, or under a state in which the resistance force received from the stopper portion after the tip of the bar reaches the stopper portion is transmitted to the feed member by the bar, than when the headstock and / or the feed member are moving in the backward direction of the bar.

[0030] According to this, the driving force of the drive motor is increased (e.g., returned to its original state) when the movement direction of the headstock and / or the feed member return to their original direction, so that the advancement of the headstock or the advancement of the stopper portion can be smoothly followed, and the bar material can be stably fed to the bar processing machine.

[0031] Alternatively, for example, it is preferable that the driving force of the drive motor is greater than that when the headstock and / or the feed member are moving in the backward direction of the bar when a predetermined time has elapsed since the headstock and / or the feed member start to move again in the forward direction of the bar, under a state in which the movement of the headstock and the movement of the feed member are synchronized by the synchronizing device, or under a state in which the movement of the headstock is transmitted as movement of the feed member by the bar, or under a state in which the resistance force received from the stopper portion after the tip of the bar reaches the stopper portion is transmitted to the feed member by the bar.

[0032] According to this, the driving force of the drive motor is increased (e.g., returned to its original state) when a predetermined time has elapsed since the movement direction of the headstock and / or the feed member have returned to their original direction. This effectively prevents the occurrence of a load (axial compressive load) on the bar stock that exceeds the desired range, while also reducing the frequency of drive control of the drive motor, thereby 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 are moving in the backward direction of the bar when the headstock and / or the feed member start to move again in the forward direction of the bar under a state in which the movement of the headstock and the movement of the feed member are synchronized by the synchronizing device, or when the movement of the headstock is transmitted as the movement of the feed member by the bar, or when the resistance force received from the stopper portion after the tip of the bar reaches the stopper portion is transmitted to the feed member by the bar, and is even greater than when the headstock and / or the feed member start to move again in the forward direction of the bar when a predetermined time has elapsed since the headstock and / or the feed member started to move again in the forward direction of the bar.

[0034] According to this, the driving force of the drive motor is increased in two stages, at the timing when the movement direction of the headstock and / or the feed member returns to its original direction and at the timing when a predetermined time has elapsed since the movement direction of the headstock and / or the feed member return to its original direction. Therefore, when the driving force is returned to the reverse direction again while it is increased by one stage, it is possible to improve the tracking ability until the torque is reduced.

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

[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 its 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 returns to its original direction. For example, the change in driving force at the former timing allows the drive motor to more quickly (preferably instantly) follow the advancement of the headstock or the advancement of the stopper portion, and the change in driving force at the latter timing allows the drive motor to return to the original driving force.

[0037] It is preferable that the drive motor is controlled based on a drive current command, 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 moving direction of the headstock and / or the moving direction of the feed member), and the value of the drive current command corresponding to each of the plurality of states can be arbitrarily set, which makes it easy to perform fine adjustments at the actual system installation site.

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

[0039] According to the present invention, under a condition in which the movement of the headstock and the movement of the feed member are synchronized by a synchronizing device, or under a condition in which the movement of the headstock is transmitted as movement of the feed member by the bar stock, or under a condition in which the resistance force received from the stopper portion after the tip of the bar stock reaches the stopper portion is transmitted to the feed member by the bar stock, 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, thereby effectively preventing the occurrence of a load (axial compressive load) on the bar stock that exceeds the desired range. [Brief description of the drawings]

[0040] [Figure 1] FIG. 1 is a side view of a bar processing system according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a side view of the bar feeder of FIG. [Diagram 3] FIG. 3 is a plan view of the bar feeder of FIGS. 1 and 2; [Figure 4] 4 is a graph showing a first example of command current control of the drive motor according to the present embodiment. [Diagram 5] 5 is a graph illustrating the load on the bar reduced by the first embodiment of FIG. 4. [Figure 6] 6 is a graph showing a second example of command current control of the drive motor according to the present embodiment. [Figure 7] 13 is a graph showing a third example of command current control of the drive motor according to the present embodiment. [Figure 8] 13 is a graph showing a fourth example of command current control of the drive motor according to the present embodiment. [Figure 9] FIG. 1 is a side view of a bar processing system without a synchronizer. [Figure 10] FIG. 2 is a schematic view showing a stopper portion of a bar processing machine. [Figure 11] FIG. 1 is a schematic perspective view of a conventional bar feeder (corresponding to FIG. 1 of Patent Document 1). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0041] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0042] (Basic configuration) FIG. 1 is a side view of a bar processing system according to one embodiment of the present invention, FIG. 2 is a side view of the bar feeder of FIG. 1, and FIG. 3 is a plan view of the bar feeder of FIGS.

[0043] As shown in FIGS. 1 to 3, a bar processing system 1 includes a bar processing machine 2 having a movable main shaft, and a bar feeder 4 for feeding a bar W to the bar processing machine 2.

[0044] The bar stock processing machine 2 has 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 arranged on the feed axis OO, and a cut-off tool 14 for cutting through the bar stock W.

[0045] On the other hand, the bar stock supplying machine 4 has a guide rail 16 extending along the feed axis OO and having a cover portion (not shown), a feed member 18 for feeding the bar stock W along the guide rail 16 to the bar stock processing machine 2, a feed member drive device 20 for moving the feed member back and forth, a bar stock supplying means (not shown) for supplying new bar stock W to the guide rail 16, a residue box portion 26 for disposing of residue stock left after product processing is completed, an oil injection device (not shown) for injecting oil into the guide rail 16 to support the bar stock W straight during bar stock processing, etc., and supporting the bar stock W on the feed axis OO with the oil, and a clamp device (not shown) for holding the bar stock W so as not to move while the rear end of the bar stock W is inserted into the receiving portion of the feed member 18.

[0046] The feed member 18 has a push member body 18a and a bar holder 18b provided at the tip of the push member body 18a. The bar holder 18b is formed with a cylindrical receiving portion into which the rear end of the bar W can be inserted. The feed member 18 also has a blade 18c for connecting to the endless chain 20d.

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

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

[0049] The synchronizer 22 has 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 extends straight parallel to the guide rail 16, an endless chain 22d that is wound around and supported by a pair of sprockets 22c along the guide rail 16 and connected to the connecting rod 22b, and a synchronizing clutch 22e that releasably synchronizes (connects) the endless chain 20b and the endless chain 22d.

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

[0051] When the bar processing system 1 is started, a new bar W is fed into the guide rail 16. Then, the tip of the bar W is gripped by a bar clamping device (not shown) provided on the bar feeder 4. Next, the servo motor 20c is driven to move the feed member 18 forward, and the rear end of the bar W is inserted into the receiving portion of the bar holder 18b. Thereafter, the bar clamping device is released, and the feed member 18 is further moved forward by the servo motor 20c, and the tip of the bar W is inserted into the spindle 8 and fed until it reaches just before the guide bush 12.

[0052] Next, the collet chuck 10 closes to grip the tip of the bar W. In addition, the movement of the headstock 6 and the movement of the feed member 18 in the forward and backward directions are synchronized by the synchronizer 22. Specifically, the movement of the headstock 6 and the movement of the feed member 18 are synchronized by engaging the synchronizing clutch 22e to synchronize the movement of the endless chains 20b and 22d.

[0053] In this synchronized state, the tip of the bar W is inserted into the guide bush 12.

[0054] For example, the portion of the bar W to be shortcutted (the tip portion Ymm) is moved to a position where it projects forward of the cut-off tool 14, that is, to the shortcut position, and is cut off by the cut-off tool 14.

[0055] Next, the collet chuck 10 opens, the synchronization device 22 is released, and the headstock 6 is moved backward by the product machining length. Then, the collet chuck 10 closes again to grip a new tip end of the bar W, and the movement of the headstock 6 and the movement of the feed member 18 in the forward and backward directions are again synchronized by the synchronization device 22.

[0056] Under such a synchronous state, a new tip end of the bar W is inserted into the guide bush 12 and cut off by, for example, the cut-off tool 14.

[0057] The above-mentioned processing steps are repeated, and when the length of the bar W becomes such that it is no longer possible to process any more products into the bar W, the bar W is discarded in the remnant box section 26 as a remnant.

[0058] (Characteristic action of this embodiment) The bar stock processing system 1 of the present embodiment can significantly prevent an excessive load (axial compressive load) from being applied to the bar stock W even when the moving direction of the headstock 6 is reversed during processing of the bar stock W. Such a characteristic action will now be described.

[0059] The servo motor 20c in this embodiment 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 a preset drive current command (selected from eight current values ​​in this embodiment) to the servo motor 20c in response to a condition based on the change in the moving direction of the headstock 6 (in this embodiment, in response to the change in the moving direction of the feed member 18 synchronized with the change in the moving direction of the headstock 6). The drive current command (e.g., each of the eight current values) can be set arbitrarily. The change in the moving 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 or the like built into the servo motor 20c itself. For example, the encoder mechanism or the like can effectively prevent erroneous detection of reverse rotation by setting a slight margin, such as setting a threshold value of "-50 rpm" instead of "0 rpm" in detecting reverse rotation. Similarly, in subsequent detection of forward rotation, false detection can be effectively prevented by setting a small margin, such as setting the threshold value to "+50 rpm" instead of "0 rpm".

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

[0061] 4, in the first embodiment, the driving force of the servo motor 20c is controlled so that when the headstock 6 starts to move in the backward direction of the bar W under a state in which the movement of the headstock 6 and the movement of the feed member 18 are synchronized by the synchronizer 22, the driving force of the servo motor 20c is smaller than when the headstock 6 is moving in the forward direction of the bar W. For example, the command current value (e.g., 20 mA) when the headstock 6 starts to move in the backward direction of the bar W is the lowest current value among the eight levels, and the command current value (e.g., 100 mA) when the headstock 6 is moving in the forward direction of the bar W is the fourth highest current value among the eight levels.

[0062] According to the first embodiment described above, the driving force of the servo motor 20c is reduced at the timing when the moving direction of the headstock 6 is reversed, so that it is possible to effectively prevent a load (axial compressive load) that exceeds the desired range from being generated on the bar W.

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

[0064] Furthermore, as shown in FIG. 4, in the first embodiment, when the headstock 6 starts to move again in the forward direction of the bar W under the condition that the movement of the headstock 6 and the movement of the feed member 18 are synchronized by the synchronizer 22, the driving force of the servo motor 20c is controlled so as to be larger than when the headstock 6 is moving in the backward direction of the bar W.

[0065] According to the first embodiment described above, the driving force of the servo motor 20c is increased (or returned to its original state in this embodiment) at the timing when the moving direction of the headstock 6 returns to its original direction, so that the forward movement of the headstock 6 or the forward movement of the stopper portion S can be smoothly followed, and the bar W can be stably fed to the bar 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 Fig. 4 may be adopted by, for example, using a first-order lag filter (not shown). The time constant of the first-order lag filter may be, for example, about 30 milliseconds.

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

[0068] 6, in the second embodiment, the driving force of the servo motor 20c is controlled so that when a predetermined time (preferably changeable, for example, about 20 milliseconds) has elapsed since the headstock 6 started to move in the backward direction of the bar W, under the condition that the movement of the headstock 6 and the movement of the feed member 18 are synchronized by the synchronizer 22, the driving force of the servo motor 20c is smaller than that when the headstock 6 is moving in the forward direction of the bar W. For example, the command current value (e.g., 20 mA) when a predetermined time has elapsed since the headstock 6 started to move in the backward direction of the bar W is the lowest current value among the eight levels, and the command current value (e.g., 100 mA) when the headstock 6 is moving in the forward direction of the bar W is the fourth highest current value among the eight levels.

[0069] According to the second embodiment, the driving force of the servo motor 20c is reduced when a predetermined time has elapsed since the direction of movement of the headstock 6 is reversed. This effectively prevents the occurrence of a load (axial compressive load) on the bar W that exceeds the desired range, while 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 FIG. 6, in the second embodiment, the driving force of the servo motor 20c is controlled so that when a predetermined time (preferably a settable value, preferably about 20 milliseconds, for example) has elapsed since the headstock 6 started to move again in the forward direction of the bar W, with the movement of the headstock 6 and the movement of the feed member 18 synchronized by the synchronizer 22, it is greater than when the headstock 6 is moving in the backward direction of the bar W.

[0071] According to the second embodiment, the driving force of the servo motor 20c is increased (returned to its original state in this embodiment) when a predetermined time has elapsed since the movement direction of the headstock 6 begins to return to its original direction. This effectively prevents the occurrence of a load (axial load) on the bar W that exceeds the desired range, while 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, when changing the command current value to the servo motor 20c, a smooth command current value change control as shown by the broken line in Fig. 6 may be adopted by, for example, using a first-order lag filter (not shown). The time constant of the first-order lag filter may be, for example, about 30 milliseconds.

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

[0074] As shown in FIG. 7, in the third embodiment, when the movement of the headstock 6 and the movement of the feed member 18 are synchronized by the synchronizer 22, the driving force of the servo motor 20c is controlled so that when the headstock 6 starts to move in the backward direction of the bar W, it is smaller than when the headstock 6 is moving in the forward direction of the bar W, and when a predetermined time (preferably adjustable, for example, about 20 milliseconds) has elapsed since the headstock 6 started to move in the backward direction of the bar W, it is even smaller than when the headstock 6 starts to move in the backward direction of the bar W. For example, the command current value (e.g., 80 mA) when the headstock 6 starts to move in the backward direction of the bar W is the third lowest current value among the eight levels, the command current value (e.g., 20 mA) when a predetermined time has elapsed since the headstock 6 started to move in the backward direction of the bar W is the lowest current value among the eight levels, and the command current value (e.g., 100 mA) when the headstock 6 is moving in the forward direction of the bar W is the fourth highest current value among the eight levels.

[0075] According to the third embodiment, the driving force of the servo motor 20c is reduced in two stages, at the timing when the moving direction of the headstock 6 is reversed and at the timing when a predetermined time has elapsed since the moving direction of the headstock 6 was reversed. This makes it possible to more effectively prevent a load (axial compressive load) that exceeds the desired range from being generated on the bar W. In addition, when the driving force is reduced by one stage and the normal rotation direction is returned to, the ability to follow the start of the normal rotation can be improved.

[0076] Furthermore, as shown in FIG. 7, in the third embodiment, when the headstock 6 starts to move in the forward direction of the bar W again under a condition in which the movement of the headstock 6 and the movement of the feed member 18 are synchronized by the synchronizer 22, the driving force of the servo motor 20c is controlled so that it is greater than when the headstock 6 is moving in the backward direction of the bar W, and is even greater than when the headstock 6 starts to move in the forward direction of the bar W again after a predetermined time has elapsed since the headstock 6 started to move in the forward direction of the bar W again.

[0077] According to the third embodiment, the driving force of the servo motor 20c is increased in two stages (returned to its original state in this embodiment) at the timing when the moving direction of the headstock 6 returns to its original direction and at the timing when a predetermined time has elapsed since the moving direction of the headstock 6 returns to its original direction. Therefore, the bar material W can be stably fed to the bar processing machine 2 while effectively preventing a load (axial compressive load) that exceeds the desired range from being generated on the bar material W. In addition, when the driving force is returned to the reverse direction again while being increased in one stage, the tracking ability up to the torque reduction can be improved.

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

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

[0080] As shown in FIG. 8, in the fourth embodiment, as in the third embodiment, the driving force of the servo motor 20c is controlled so that when the headstock 6 starts to move in the backward direction of the bar W under a state in which the movement of the headstock 6 and the movement of the feed member 18 are synchronized by the synchronizer 22, the driving force of the servo motor 20c is smaller than when the headstock 6 is moving in the forward direction of the bar W, and is even smaller than when the headstock 6 starts to move in the backward direction of the bar W after a predetermined time (preferably adjustable, for example, about 20 milliseconds) has elapsed since the headstock 6 started to move in the backward direction of the bar W. For example, the command current value (e.g., 80 mA) when the headstock 6 starts to move in the backward direction of the bar W is the third lowest current value among the eight levels, the command current value (e.g., 20 mA) when a predetermined time has elapsed since the headstock 6 started to move in the backward direction of the bar W is the lowest current value among the eight levels, and the command current value (e.g., 100 mA) when the headstock 6 is moving in the forward direction of the bar W is the fourth highest current value among the eight levels.

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

[0082] As shown in FIG. 8, in the fourth embodiment, when the headstock 6 starts to move in the forward direction of the bar W again, with the movement of the headstock 6 and the movement of the feed member 18 synchronized by the synchronizer 22, the driving force of the servo motor 20c is controlled so that it is greater than when the headstock 6 is moving in the forward direction of the bar W, and is smaller than when the headstock 6 starts to move in the forward direction of the bar W again, a predetermined time after the headstock 6 starts to move in the forward direction of the bar W again.

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

[0084] In the fourth embodiment, 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 Fig. 8 may be adopted by, for example, using a first-order lag filter (not shown). The time constant of the first-order lag filter may be, for example, about 30 milliseconds.

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

[0086] For example, a magnetic scaler or the like may be installed corresponding to the headstock 6, and the moving direction of the headstock 6 may be directly detected (measured). Alternatively, a mode may be adopted in which the moving direction of the headstock 6 is known in advance based on a program applied to the movement control of the headstock 6.

[0087] On the other hand, the manner of detecting (measuring) the moving direction of the feed member 18 is not limited to the above embodiment, at least at the time of filing this application, and detection (measurement) may be performed, for example, by installing a magnetic scaler or the like corresponding to the feed member 18.

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

[0089] (Modification without synchronizer 20) The command current value change control in each of the above-mentioned embodiments is also effective in a bar machining system that does not have a synchronizer. In a bar machining system that does not have a synchronizer, the bar itself acts as an intermediary, the movement of the headstock is transmitted to the feed member side, and the feed member is linked (moved). Even in such a case, the command current value change control in each of the above-mentioned embodiments is effective.

[0090] Fig. 9 is a side view of a bar processing system without a synchronizing device. Except for not having a synchronizing device 20, the other configuration is the same as that of the bar processing system of the embodiment shown in Fig. 1. In Fig. 9, the same components as those of the embodiment shown in Fig. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0091] (First Example (2)) Even in a bar processing system that does not have a synchronous device, the application of the command current control of the servo motor 20c (drive motor) shown in FIG. 4 is effective (first embodiment).

[0092] In this case, the driving force of the servo motor 20c is controlled so that when the headstock 6 starts to move in the backward direction of the bar W under a state in which the movement of the headstock 6 is transmitted as the movement of the feed member 18 by the bar W, the driving force is smaller than when the headstock 6 is moving in the forward direction of the bar W. For example, the command current value (e.g., 20 mA) when the headstock 6 starts to move in the backward direction of the bar W is the lowest current value among the eight levels, and the command current value (e.g., 100 mA) when the headstock 6 is moving in the forward direction of the bar W is the fourth highest current value among the eight levels.

[0093] According to the first embodiment described above, the driving force of the servo motor 20c is reduced at the timing when the moving direction of the headstock 6 is reversed, so that it is possible to effectively prevent a load (axial compressive load) that exceeds the desired range from being generated on the bar W.

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

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

[0096] According to the first embodiment described above, the driving force of the servo motor 20c is increased (or returned to its original state in this embodiment) at the timing when the moving direction of the headstock 6 returns to its original direction, so that the driving force of the servo motor 20c smoothly follows the forward movement of the headstock 6 and the bar W can be stably fed to the bar processing machine 2.

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

[0098] (Second Example (2)) Even in a bar processing system having no synchronous device, the command current control of the servo motor 20c (drive motor) shown in FIG. 6 is effectively applied (second embodiment).

[0099] In this case, the driving force of the servo motor 20c is controlled so that when a predetermined time (preferably a settable value, preferably about 20 milliseconds, for example) has elapsed since the headstock 6 started to move in the backward direction of the bar W, under the condition that the movement of the headstock 6 is transmitted as the movement of the feed member 18 by the bar W, it is smaller than when the headstock 6 is moving in the forward direction of the bar W. For example, the command current value (e.g., 20 mA) when a predetermined time has elapsed since the headstock 6 started to move in the backward direction of the bar W is the lowest current value among the eight levels, and the command current value (e.g., 100 mA) when the headstock 6 is moving in the forward direction of the bar W is the fourth highest current value among the eight levels.

[0100] According to the second embodiment, the driving force of the servo motor 20c is reduced when a predetermined time has elapsed since the direction of movement of the headstock 6 is reversed. This effectively prevents the occurrence of a load (axial compressive load) on the bar W that exceeds the desired range, while 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 so that when a predetermined time (preferably adjustable, for example, approximately 20 milliseconds) has elapsed since the headstock 6 starts to move again in the forward direction of the bar W while the movement of the headstock 6 is being transmitted as movement of the feed member 18 by the bar W, the driving force of the servo motor 20c is greater than when the headstock 6 is moving in the backward direction of the bar W.

[0102] According to the second embodiment, the driving force of the servo motor 20c is increased (returned to its original state in this embodiment) when a predetermined time has elapsed since the movement direction of the headstock 6 begins to return to its original direction. This effectively prevents the occurrence of a load (axial load) on the bar W that exceeds the desired range, while 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, when changing the command current value to the servo motor 20c, for example, a first-order lag filter (not shown) may be used to smoothly change the command current value as shown by the dashed line in Fig. 6. The time constant of the first-order lag filter may be, for example, about 30 milliseconds.

[0104] (Third Example (2)) Even in a bar machining system having no synchronous device, the command current control of the servo motor 20c (drive motor) shown in FIG. 7 is effectively applied (third embodiment).

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

[0106] According to the third embodiment, the driving force of the servo motor 20c is reduced in two stages, at the timing when the moving direction of the headstock 6 is reversed and at the timing when a predetermined time has elapsed since the moving direction of the headstock 6 was reversed. This makes it possible to more effectively prevent a load (axial compressive load) that exceeds the desired range from being generated on the bar W. In addition, when the driving force is reduced by one stage and the normal rotation direction is returned to, the ability to follow the start of the normal rotation can be improved.

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

[0108] According to the third embodiment, the driving force of the servo motor 20c is increased in two stages (returned to its original state in this embodiment) at the timing when the moving direction of the headstock 6 returns to its original direction and at the timing when a predetermined time has elapsed since the moving direction of the headstock 6 returns to its original direction. Therefore, the bar material W can be stably fed to the bar processing machine 2 while effectively preventing a load (axial load) that exceeds the desired range from being generated on the bar material W. In addition, when the driving force is returned to the reverse direction again while being increased in one stage, the tracking ability up to the torque reduction can be improved.

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

[0110] (Fourth Example (2)) Even in a bar machining system having no synchronous device, the command current control of the servo motor 20c (drive motor) shown in FIG. 8 is effectively applied (fourth embodiment).

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

[0112] According to the fourth embodiment, the driving force of the servo motor 20c is reduced in two stages, at the timing when the moving direction of the headstock 6 is reversed and at the timing when a predetermined time has elapsed since the moving direction of the headstock 6 was reversed. This makes it possible to more effectively prevent a load (axial compressive load) that exceeds the desired range from being generated on the bar W. In addition, when the driving force is reduced by one stage and the normal rotation direction is returned to, the ability to follow the start of the normal rotation can be improved.

[0113] Furthermore, in the fourth embodiment, when the headstock 6 starts to move in the forward direction of the bar W again under a state in which the movement of the headstock 6 is transmitted as the movement of the feed member 18 by the bar W, the driving force of the servo motor 20c is controlled so as to be larger than when the headstock 6 is moving in the forward direction of the bar W again, and to be smaller than when the headstock 6 starts to move in the forward direction of the bar W again a predetermined time has elapsed since the headstock 6 started to move in the forward direction of the bar W again.

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

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

[0116] (Modification in which the headstock does not move) The command current value change control in each of the above-mentioned embodiments is also effective for use in positioning the tip of the bar W by abutting it against the stopper portion S (see FIG. 10) in a bar machining system in which the headstock does not move (not shown, but including the case where the above-mentioned bar machining system is used in a form in which the headstock does not move). (The stopper portion S exists on the movement path of the bar W when the bar W is positioned, but once the position of the bar W is determined, it is adapted to move away from the movement path.)

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

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

[0119] According to the first embodiment described above, the driving force of the servo motor 20c is reduced at the timing when the moving direction of the headstock 6 is reversed, so that it is possible to effectively prevent a load (axial compressive load) that exceeds the desired range from being generated on the bar W.

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

[0121] Furthermore, in this case, when the headstock 6 starts to move again in the forward direction of the bar W after the tip of the bar W reaches the stopper portion S and the resistance force received from the stopper portion S is transmitted to the feed member 18 by the bar W, the driving force of the servo motor 20c is controlled so as to be greater than when the headstock 6 is moving in the backward direction of the bar W.

[0122] According to the first embodiment described above, the driving force of the servo motor 20c is increased (or returned to its original state in this embodiment) at the timing when the moving direction of the headstock 6 returns to its original direction, so that the driving force of the servo motor 20c smoothly follows the forward movement of the headstock 6 and the bar W can be stably fed to the bar processing machine 2.

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

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

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

[0126] According to the second embodiment, the driving force of the servo motor 20c is reduced when a predetermined time has elapsed since the direction of movement of the headstock 6 is reversed. This effectively prevents the occurrence of a load (axial compressive load) on the bar W that exceeds the desired range, while 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, when the resistance force received from the stopper portion S after the tip of the bar W reaches the stopper portion S is being transmitted to the feed member 18 by the bar W, the driving force of the servo motor 20c is controlled so that when a predetermined time (preferably adjustable, for example, about 20 milliseconds) has elapsed since the headstock 6 started to move again in the forward direction of the bar W, it is greater than when the headstock 6 is moving in the backward direction of the bar W.

[0128] According to the second embodiment, the driving force of the servo motor 20c is increased (returned to its original state in this embodiment) when a predetermined time has elapsed since the movement direction of the headstock 6 begins to return to its original direction. This effectively prevents the occurrence of a load (axial compressive load) on the bar W that exceeds the desired range, while 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, when changing the command current value to the servo motor 20c, for example, a first-order lag filter (not shown) may be used to smoothly change the command current value as shown by the dashed line in Fig. 6. The time constant of the first-order lag filter may be, for example, about 30 milliseconds.

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

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

[0132] According to the third embodiment, the driving force of the servo motor 20c is reduced in two stages, at the timing when the moving direction of the headstock 6 is reversed and at the timing when a predetermined time has elapsed since the moving direction of the headstock 6 was reversed. This makes it possible to more effectively prevent a load (axial compressive load) that exceeds the desired range from being generated on the bar W. In addition, when the driving force is reduced by one stage and the normal rotation direction is returned to, the ability to follow the start of the normal rotation can be improved.

[0133] Furthermore, in this case, when the headstock 6 starts to move again in the forward direction of the bar W under the condition that the resistance force received from the stopper portion S after the tip of the bar W reaches the stopper portion S is being transmitted to the feed member 18 by the bar W, the driving force of the servo motor 20c is controlled so that it is greater than when the headstock 6 is moving in the backward direction of the bar W, and is even greater than when the headstock 6 starts to move again in the forward direction of the bar W after a predetermined time has elapsed since the headstock 6 started to move again in the forward direction of the bar W.

[0134] According to the third embodiment, the driving force of the servo motor 20c is increased in two stages (returned to its original state in this embodiment) at the timing when the moving direction of the headstock 6 returns to its original direction and at the timing when a predetermined time has elapsed since the moving direction of the headstock 6 returns to its original direction. Therefore, the bar material W can be stably fed to the bar processing machine 2 while effectively preventing a load (axial compressive load) that exceeds the desired range from being generated on the bar material W. In addition, when the driving force is returned to the reverse direction again while being increased in one stage, the tracking ability up to the torque reduction can be improved.

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

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

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

[0138] According to the fourth embodiment, the driving force of the servo motor 20c is reduced in two stages, at the timing when the moving direction of the headstock 6 is reversed and at the timing when a predetermined time has elapsed since the moving direction of the headstock 6 was reversed. This makes it possible to more effectively prevent a load (axial compressive load) that exceeds the desired range from being generated on the bar W. In addition, when the driving force is reduced by one stage and the normal rotation direction is returned to, the ability to follow the start of the normal rotation can be improved.

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

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

[0141] In this case, when changing the command current value to the servo motor 20c, for example, a first-order lag filter (not shown) may be used to smoothly change the command current value as shown by the dashed line in Fig. 8. The time constant of the first-order lag filter may be, for example, about 30 milliseconds. [Explanation of symbols]

[0142] 1. Bar processing system 2 Bar processing machine 4 Bar feeder 6 Headstock 8 spindle 10 Collet Chuck 12 Guide bush 14 Cutting tool 16 Guide rail 18 Feed member 18a Pushing member body 18b Bar holding part 18c Feather 20 Feed member drive device 20a sprocket 20b endless chain 20c Servo motor (drive motor) 22 Synchronous Device 22a Connecting plate 22b Connecting rod 22c sprocket 22d endless chain 22e Synchronous clutch 24 Control Unit 26 Remnant box section 106 Headstock 112 Feed member 120 Rotating body linked with feed member 122 Endless chain for feeding components 130 Clutch means 148 Headstock linked rotor 149 Drive motor 150 Headstock endless chain

Claims

1. A bar processing machine with a moving headstock; a bar feeder that advances the bar by pushing a rear end of the bar with a feed member; a synchronizing device capable of synchronizing the movement of the headstock of the bar processing machine with the movement of the feed member of the bar feeder in the forward and backward directions of the bar; Equipped with the bar feeder has a drive motor capable of providing a moving force to the feed member of the bar feeder; The drive motor is controlled in response to a change in the moving direction of the headstock and / or the moving direction of the feed member, while the movement of the headstock and the movement of the feed member are synchronized by the synchronizing device. A bar processing system comprising:

2. A bar processing machine with a moving headstock; a bar feeder that advances the bar by pushing a rear end of the bar with a feed member; Equipped with the bar feeder has a drive motor capable of providing a moving force to the feed member of the bar feeder; The drive motor is controlled in response to a change in the moving direction of the headstock and / or the moving direction of the feed member under a condition in which the movement of the headstock is transmitted as the movement of the feed member by the bar. A bar processing system comprising:

3. a bar processing machine having a stopper portion for positioning a tip end of the bar; a bar feeder that advances the bar by pushing a rear end of the bar with a feed member; Equipped with the bar feeder has a drive motor capable of providing a moving force to the feed member of the bar feeder; The drive motor is controlled in response to a change in the moving direction of the feed member under a condition in which 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 by the bar material. A bar processing system comprising:

4. The driving force of the drive motor is smaller when the headstock and / or the feed member start to move in the backward direction of the bar than when the headstock and / or the feed member are moving in the forward direction of the bar.

4. A bar processing system according to claim 1, wherein the bar processing system is a bar processing system.

5. The driving force of the drive motor is smaller when a predetermined time has elapsed since the headstock and / or the feed member started to move in the backward direction of the bar than when the headstock and / or the feed member are moving in the forward direction of the bar.

4. A bar processing system according to claim 1, wherein the bar processing system is a bar processing system.

6. The driving force of the drive motor is When the headstock starts to move in the backward direction of the bar, the headstock and / or the feed member are smaller than when the headstock and / or the feed member are moving in the forward direction of the bar, When a predetermined time has elapsed since the headstock started to move in the backward direction of the bar, the time when the headstock and / or the feed member started to move in the backward direction of the bar is smaller than the time when the headstock and / or the feed member started to move in the backward direction of the bar.

4. A bar processing system according to claim 1, wherein the bar processing system is a bar processing system.

7. When the headstock and / or the feed member start to move in the forward direction of the bar again, the driving force of the drive motor is greater than when the headstock and / or the feed member are moving in the backward direction of the bar.

4. A bar processing system according to claim 1, wherein the bar processing system is a bar processing system.

8. The driving force of the drive motor is greater when a predetermined time has elapsed since the headstock and / or the feed member start to move in the forward direction of the bar again than when the headstock and / or the feed member are moving in the backward direction of the bar.

4. A bar processing system according to claim 1, wherein the bar processing system is a bar processing system.

9. The driving force of the drive motor is When the headstock and / or the feed member start to move again in the forward direction of the bar, the headstock and / or the feed member are moved more rapidly than when the headstock and / or the feed member are moving in the backward direction of the bar, When a predetermined time has elapsed since the headstock and / or the feed member started to move again in the advancing direction of the bar, the headstock and / or the feed member are moved at a rate that is larger than the rate at which the headstock and / or the feed member started to move again in the advancing direction of the bar.

4. A bar processing system according to claim 1, wherein the bar processing system is a bar processing system.

10. The driving force of the drive motor is When the headstock starts to move in the backward direction of the bar, the headstock and / or the feed member are moved in the forward direction of the bar, and When a predetermined time has elapsed since the headstock started to move in the backward direction of the bar, the time is smaller than when the headstock and / or the feed member started to move in the backward direction of the bar.

4. A bar processing system according to claim 1, wherein the bar processing system is a bar processing system.

11. The drive motor is controlled based on a drive current command. the value of the drive current command is switched in response to each of a plurality of states; The drive current command values ​​corresponding to the respective states can be arbitrarily set.

4. A bar processing system according to claim 1, wherein the bar processing system is a bar processing system.

12. A change in the moving direction of the headstock and / or the moving direction of the feed member is detected by rotation of an encoder mechanism, The threshold value for determining the change in the rotation direction based on the rotation of the encoder mechanism can be set arbitrarily.

4. A bar processing system according to claim 1, wherein the bar processing system is a bar processing system.

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