JPH078388B2 - Roll feeder - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a roll feeder, and more specifically, a feed-side feed roll that is driven by a servo motor to supply a coil material or a sheet material to a processing stage, and also is driven by a servo motor to discharge a coil material or a sheet material from the processing stage. In the roll feeder of the double roll feed system independently provided with the discharge side feed roll, the feeding length in the vicinity of the end of the material is accurately controlled, and the material from the supply side feed roll to the discharge side feed roll is controlled. The present invention relates to a new roll feeder that enables smooth delivery.

[Prior art]

For example, a so-called double roll feed type roll feeder in which a feed side feed roll and a discharge side feed roll are arranged in front of and behind the processing stage is used as a feed device for supplying a coil material or a sheet material to a processing stage such as a press machine. It has been known from the past, and when this type of double roll feed type roll feeder is used, the material is conveyed by the discharge side feed roll even after the end of the sheet material or the coil material has passed the position of the supply side feed roll. Therefore, the material can be effectively used even near the end of the material.

[Problems to be Solved by the Invention]

Now, in the case of this type of double roll feed type roll feeder, when the material is conveyed by using both the feed side feed roll and the discharge side feed roll at the same time near the end of the coil material or sheet material, Unless the side feed roll and the discharge side feed roll are transporting the material at exactly the same speed, one of the feed rolls acts as a load on the other feed roll, which adversely affects the flatness of the material. there is a possibility. Therefore, in the case of the conventional double roll feed type roll feeder, the material is conveyed using only the feed side feed roll until the end of the material passes the feed side feed roll, and the end of the material is fed to the feed side feed roll. After passing through the rolls, the feed side feed rolls are released, the discharge side feed rolls clamp the material, and the discharge side feed rolls convey the material. However, in the case of the method of delivering the material from the feed side feed roll to the discharge side feed roll in the vicinity of the end of the material as described above, control accuracy of the delivery timing is required, and particularly the operation cycle of the press device and other processing stages is required. When it is fast, the so-called mechanical feeding at the time of delivery is not negligible because it is necessary to shorten the entire delivery time, which is a cause of deteriorating the accuracy of the carry amount.

[Means for solving problems]

The present invention has been made in view of such problems,
An object of the present invention is to provide a novel roll feeder capable of smoothly delivering a material without being affected by so-called mechanical feeding at the time of delivering the material from the feed side feed roll to the discharge side feed roll. In summary, the roll feeder of the present invention comprises: a feed-side feed roll which is arranged before the processing stage and has a release mechanism, and a discharge-side feed roll which is arranged after the processing stage and has a release mechanism. In a roll feeder in which each of the side feed roll and the discharge side feed roll is servo-driven, at least the discharge side feed roll is provided with a torque limiting mechanism: the supply side feed roll, the discharge side feed roll, and the discharge side. A side feed roll torque limiting mechanism, and a release mechanism of the supply side feed roll,
And a control means for independently controlling the release mechanism of the discharge side feed roll, so that the material can be smoothly transferred from the supply side feed roll to the discharge side feed roll near the end of the material. Both are designed to be able to sufficiently follow the speed increase of the processing stage.

[Action]

That is, according to the roll feeder of the present invention, the material is conveyed by both the feed-side feed roll and the discharge-side feed roll at least near the end of the material, and the discharge-side feed roll is fed after the end of the material has passed through the feed-side feed roll. Since the material is conveyed only by itself, it is less likely to be affected by so-called mechanical delay at the time of delivering the material, and when the material is simultaneously conveyed by the feed side feed roller and the discharge side feed roll near the end of the material, the discharge side feed roll is used. Since the torque limit is applied to, the discharge side feed roll rotates following the supply side feed roll.
It is possible to avoid the step-out caused by the simultaneous conveyance.

【Example】

An embodiment of the present invention will be described in detail below with reference to the drawings. The embodiment described below is an embodiment in which the present invention is applied to a roll feeder that supplies a coil material to a pressing device. First, FIG. 1 shows the principle of a roll feeder according to one embodiment of the present invention. In the figure, 1 shows a press device which is an example of a processing stage, and a press device 1 is provided in front of the press device 1. A feed-side feed roll 3 for supplying the coil material 2 is arranged, and a discharge-side feed roll 4 for discharging the coil material 2 from the press device 1 is arranged downstream of the press device 1. First, the feed-side feed roll 3 has a source roll 3a and a driven roll 3b.
Close to the transport plane of. Then, the source roll 3a is configured to rotate in the conveying direction by the rotation of the servo motor 3c being transmitted via the pulley 3d-belt 3e-pulley 3f, and the driven roll 3b is driven by the cylinder 3g to the source roll 3a. By being pushed to the side, it is configured to rotate following the source roll 3a. 3h indicates a connecting rod for transmitting the pressing force of the cylinder 3g to the driven roll 3b, and 3i indicates a spring for releasing the driven roll 3b from the source roll 3a. Similarly, the discharge-side feed roll 4 has a source roll 4a and a driven roll 4b, and the side faces of both rolls are in close contact with the conveyance plane of the coil material 2. Then, the source roll 4a is adapted to rotate in the transport direction by the rotation of the servo motor 4c being transmitted via the pulley 4d-belt 4e-pulley 4f, and the driven roll 4b is driven by the cylinder 4g to the source roll 4a. By being pressed to the side, it is configured to rotate following the source roll 4a. In addition, 4h indicates a connecting rod for transmitting the pressing force of the cylinder 4g to the driven roll 4b, and 4i indicates a spring for releasing the driven roll 4b from the source roll 4a. Next, S ₁ , S _2, and S ₃ are photoelectric sensors, and each photoelectric sensor S ₁ , S _2, and S ₃ is composed of, for example, a light emitting diode and a phototransistor, and is used for passing the coil material 2 at the end. Accompanying
It is adapted to be turned on by forming an optical path from the light emitting diode to the phototransistor. The first sensor S ₁ is for detecting that the end of the coil material 2 has approached the feed-side feed roll 3, and is arranged at least one feed pitch forward of the feed-side feed roll 3. The second sensor S ₂ is for detecting that the end of the coil material 2 has reached the position of the feed side feed roll 3, and is arranged immediately before the feed side feed roll 3. Further, in the third sensor S ₃ , the end of the coil material 2 is the pressing device 1
The third sensor S ₃ is arranged in front of the press device 1 by at least one feed pitch. The operation of this embodiment will be summarized as follows: (1) In the normal conveying state, the coil material 2 is conveyed only by the feed-side feed roll 3, and (2) the end of the coil material 2 is connected to the first sensor S ₁
When detecting, the coil material 2 is simultaneously conveyed by the feed side feed roll 3 and the discharge side feed roll 4 while the torque is limited to the discharge side feed roll 4, and (3) the second sensor S ₂ moves the end of the coil material 2 to the end. When detected, the supply side feed roll 3 is released, the torque limit of the discharge side feed roll 4 is released, and the coil material 2 is conveyed only by the discharge side feed roll 4. FIG. 2 is a circuit diagram showing an example of the control circuit of the present invention.
_{a · S 1 · S 2 ·} S 3 each servo motor 3a · servo motor 4a · first sensor S ₁ · second sensors described with reference to FIG. 1 S ₂ ·
A third sensor S ₃ is shown, the first sensor S ₁ is a light emitting diode D ₁ and a phototransistor Q ₁ , the second sensor S ₂ is a light emitting diode D ₂ and a phototransistor Q ₂ , and the third sensor S ₃ is a light emitting device. Each is composed of a diode D ₃ and a phototransistor Q ₃ . Further, 5 is a control device for controlling the entire system, 6 is a memory storing at least a control program, 7 and 8 are output interfaces, and 9 is an input interface, respectively, for each sensor S ₁ , S ₂ , S ₃ . The output is fed back to the control device 5 via the input interface 9. Further, the servo motor 3a (4a) constitutes a known feedback loop for positioning control, and 3j (4j) is a pulse generator that digitizes the rotation amount of the feed side feed roll 3 (discharge side feed roll 4), 3k (4k) indicates an error counter and 3l (4l) indicates a speed amplifier. Then, through the output interface 7, the error counter
When the command value is given to 3k (4k), the error counter 3k (4k
k) outputs the deviation between the command value and the current value added from the pulse generator 3j (4j), and the speed amplifier 3l (4l) drives the servo motor 3a (4a) based on this deviation,
The supply side feed roll 3 (discharging side feed roll 4) to be controlled follows the command value. Now, although this type of feedback loop itself is well known in the prior art, the characteristic point of the present invention is that the speed amplifier 4l constituting the discharge side feed roll 4 is provided with a torque limiting mechanism, and its load is Even if it rises, the torque above a certain value cannot be generated. Although various methods can be considered for the torque limiting method itself, in the present embodiment, a current limiter is provided at the output portion of the speed amplifier 4l, and the current limiter control terminal 4n for operating the current limiter is provided as the output interface 8. Connected to the control device 5 via the output interface 8 and sending a control signal to the current limiter control terminal 4n via the output interface 8 so that the drive current above a certain level does not flow to the speed amplifier 4l when the current limiter is operated. Is assumed. Further, in FIG. 2, 3m and 4m are solenoid coils of a directional control valve for switching the cylinders 3g and 4g, respectively. Next, the operation of this embodiment will be described with reference to the above matters and the flowchart of FIG. First, when the system is activated, the control device 5 activates the photoelectric sensors S ₁ , S ₂ , S ₃ via the output interface 8. Then, after that, the control device 5 generates a start instruction to the solenoid coil 3m forming the supply side feed roll 3, and at the same time, generates a start instruction to the servo motor 3c forming the supply side feed roll 3. First, as a result of the start instruction to the solenoid 3m, the solenoid 3m is excited by the output interface 8, and the cylinder 3g pushes down the driven roll 3b constituting the feed side feed roll 3 against the spring 3i. Further, as a result of the instruction to start the servo motor 3c, a command pulse is added from the output interface 7 to the error counter 3k constituting the feed roll 3 on the supply side, and the error counter 3k is added. Then, the speed amplifier 3l gives a drive current corresponding to the output value of the error counter 3k to the servo motor 3c,
Rotate 3c. Since the rotation of the servomotor 3c is transmitted to the source roll 3a via the pulley 3d-belt 3e-pulley 3f, the source roll 3a constituting the feed side feed roll 3 rotates in the conveyance direction of the coil material 2. It will be. Since the driven roll 3b is pushed down by the cylinder 3g toward the source roll 3a at this time, the driven roll 3b rotates following the source roll 3a, and the coil material 2 constitutes the feed side feed roll 3. It is conveyed while being sandwiched between the source roll 3a and the driven roll 3b. The feed amount of the feed roll 3 on the supply side is digitized by the pulse generator 3j, and the output pulse of the pulse generator 3j acts to subtract the error counter 3k. Therefore, the error counter 3k corresponds to the deviation between the command value and the current value. Therefore, the feed amount by the feed roll 3 on the supply side follows the command value given to the error counter 3 via the output interface 7. On the other hand, the control device 5 is a photoelectric sensor from the system startup.
Power is applied to S ₁ , S _2, and S ₃ , but while the coil material 2 remains sufficiently, the light-emitting diodes D ₁ , D ₂ , and S that constitute each sensor S ₁ , S _2, and S ₃ Since the optical path from D ₃ to the phototransistors Q ₁ , Q _2, and Q ₃ is blocked by the coil material 2, all the phototransistors Q ₁ , Q _2, and Q ₃ are blocked, and the input of each stage of the input interface 9 is All are at H level. Then, the controller 5 outputs the output of the phototransistor Q ₁ at H level.
During the level, the start instruction to the servo motor 4c forming the discharge side feed roll 4 is not generated, and the start instruction to the solenoid coil 4m forming the discharge side feed roll 4 is not generated either. It will be conveyed only by the feed roll 3. The coil material 2 is pressed by the pressing device 1 in the process of being conveyed in this way. Now, in this way, as the conveyance of the coil material 2 progresses, the remaining amount of the coil material 2 decreases, and eventually the end of the coil material 2 passes the position of the first sensor S ₁ . As a result, an optical path from the light emitting diode D ₁ forming the first sensor S ₁ to the phototransistor Q ₁ is formed, so that the phototransistor Q ₁ becomes conductive and the input corresponding to the phototransistor Q ₁ of the input interface 9 is L The control device 5 knows that the end of the coil material 2 has passed the position of the first sensor S _{1 at} the level. Now, when the end of the coil material 2 passes the position of the first sensor S ₁ , the control device 5 causes the supply side feed roll 3 to continue the conveying operation as it is, and the discharge side feed roll 4
It excites the solenoid coil 4m, which constitutes the above, and also gives a command pulse to the error amplifier 4k. At this time, the same pulse as the command pulse given to the error amplifier 3k forming the supply side feed roll 3 is distributed to the error amplifier 4k forming the discharge side feed roll 4. Since the discharge-side feed roll 4 is basically given the same (or extremely similar) characteristics as the supply-side feed roll 3, the discharge-side feed roll 4 operates similarly to the supply-side feed roll 3. The coil material 2 is simultaneously conveyed by the discharge side feed roll 4 and the supply side feed roll 3. By the way, although the discharge-side feed roll 4 is basically given the same (or extremely approximate) characteristic as the supply-side feed roll 3, there is no guarantee that the two characteristics are completely the same. If the step-out occurs, the smooth transfer operation may be hindered. However, in this embodiment, after the first sensor S ₁ is turned on, the control device 5 gives a control signal to the current limiter control terminal 4n of the speed amplifier 4l constituting the discharge side feed roll 4 via the output interface 8, The current limiter is activated. When the discharge side feed roll 4 tries to precede the supply side feed roll 3, the supply side feed roll 3 acts as a load on the discharge side feed roll 4, and the discharge side feed roll 4 4, the discharge side feed roll 4 cannot lead the supply side feed roll 3 because the current limiter operates in the discharge side feed roll 4 as described above. Therefore, the discharge-side feed roll 4 rotates within the range of the speed of the supply-side feed roll 3, and it becomes possible to carry out smooth transport as in the case of transporting with a single feed roll. Therefore, in order to maximize the effect of the present embodiment that facilitates simultaneous conveyance by the discharge-side feed roll 4 and the supply-side feed roll 3, the discharge-side feed roll 4 has a characteristic as a single body when the discharge-side feed roll 4 is used. It is desirable to make an adjustment that slightly precedes 3. An error counter that constitutes the discharge side feed roll 4
Error counter that composes 4k and feed side feed roll 3
Since the common command pulse is distributed to 3k, it goes without saying that the coil material 2 is conveyed by a predetermined amount at the end of the 1-pitch conveyance cycle. Now, when the transport operation is further performed after the end of the coil material 2 has passed the first sensor S ₁ , the end of the coil material 2 passes the position of the second sensor S ₂ in due course. As a result, an optical path from the light emitting diode D ₂ forming the second sensor S ₂ to the phototransistor Q ₂ is formed, so that the phototransistor Q ₂ becomes conductive and the input corresponding to the phototransistor Q ₂ of the input interface 9 is L The control device 5 knows that the end of the coil material 2 has passed the position of the second sensor S _{2 at} the level. Now, when the end of the coil material 2 passes the position of the second sensor S ₂ , the control device 5 cuts off the exciting current given to the solenoid coil 3m forming the feed roll 3 via the output interface 8. At the same time, the command pulse given to the error counter 3k constituting the feed side feed roll 3 via the output interface 7 is stopped. In this way, the solenoid coil 3m forming the supply side feed roll 3 is demagnetized by cutting off the exciting current, so that the cylinder 3g is switched in the backward direction,
The driven roll 3b constituting the feed side feed roll 3 is released by the spring 3i. Further, since the servo motor 3c stops rotating when the command pulse stops, the source roll 3a forming the feed side feed roll 3 also stops rotating. Then, the solenoid coil that constitutes the discharge side feed roll 4 even after the end of the coil material 2 has passed the second sensor S _2.
4m continues to be excited, and the command pulse is given to the error counter 4k, so that the end of the coil material 2 is the second sensor S ₂
After passing through, the coil material 2 is conveyed only by the discharge-side feed roll 4. Also, after the end of the coil material 2 has passed the second sensor S ₂ , the discharge side feed roll 4 alone carries as described above, so that the supply side feed roll 3 and the discharge side feed roll 4 are out of step. Therefore, when the end of the coil material 2 passes through the second sensor S ₂ , the control device 5 precedes the supply-side feed roll 3 and the release / stop processing, and outputs it via the output interface 8. The current limitation for the speed amplifier 4l forming the feed roll 4 is released. Then, the controller 5 determines that the end of the coil material 2 is the third sensor S ₃
Until passes, to perform the conveying operation by the discharge-side feed rolls 4, ends of the coil material 2 passes through the third sensor S _3, the phototransistor Q ₃ constituting the third sensor S ₃ is turned on, the transfer process To finish. As described above, in the roll feeder of this embodiment, the discharge side feed roll 4 is simultaneously conveyed within the range of the conveyance speed of the supply side feed roll 3 before the end of the coil material 2 passes through the supply side feed roll 3. Therefore, even if the operation cycle of the press machine 1 becomes faster, there is no possibility that a so-called mechanical delay will occur when delivering the material from the feed side feed roll 3 to the discharge side feed roll 4, and smooth delivery is possible. Becomes In the above, an example in which three types of sensors are provided is shown, but since the position of the feed side feed roll 3 and the position of the press device 1 with respect to the position of the first sensor S ₁ are fixed,
The end position of the coil material is calculated from the feed length after the detection output of the first sensor S ₁ is generated, and the second sensor S ₂ and the third sensor are calculated.
S ₃ may be omitted. Further, in the above, only the feed-side feed roll 3 is independently conveyed until the end of the coil material 2 passes the position of the first sensor, and the feed-side feed roll 3 is fed after the end of the coil material 2 passes the position of the first sensor. An example has been shown in which the coil material 2 is simultaneously conveyed by the feed side feed roll 3 and the discharge side feed roll 4 while the torque is limited to the roll 4, but in the present invention, the end of the material is the feed side feed roll 3. Before passing through the position, the feed side feed roll 3 and the discharge side feed roll 4 simultaneously convey the material while limiting the torque to the discharge side feed roll 4 to transfer the material from the feed side feed roll 3 to the discharge side feed roll. The essence is to smoothly deliver, and the feed-side feed roll 3 and the discharge-side feed roll 4 are constantly torque-limited while being constantly applied. Dororu may be as simultaneous transport of material by 4. Further, when the feed side feed roll 3 and the discharge side feed roll 4 simultaneously convey the material while the torque is always limited to the discharge side feed roll 4, the first sensor S ₁ is not necessary. Needless to say, the second sensor S ₂ is required. Further, although an example in which a coil material is used as the material has been shown above, it goes without saying that the present invention can be applied to other than the coil material as long as it is a continuous material. Further, although the example in which the press device is used as an example of the processing stage has been described above, it goes without saying that the processing stage is not limited to the pressing device. Further, although the photoelectric sensor is used as an example of the sensor in the above, it goes without saying that the structure of the sensor is not an essential element as long as it can detect the end. Further, the case where the feed-side feed roll is arranged in the preceding stage of the single machining stage and the discharge-side feed roll is arranged in the latter stage of the machining stage has been described above. Even when each feed roll is arranged in the same direction and a series of processing is performed while sequentially transporting the material between the adjacent processing stages, the above-mentioned plurality of feed rolls serve as the discharge side feed rolls for the preceding processing stage. The present invention can be applied to the case where it has a function of acting as a feed-side feed roll for the subsequent processing stage.

【effect】

As described above, according to the present invention, before the end of the material passes the feed side feed roll, the discharge side feed roll carries out simultaneous feeding of the material within the range of the feeding speed of the feed side feed roll, Even if the operation cycle of the processing stage becomes faster, there is no possibility of a so-called mechanical delay in the delivery of the material from the feed side feed roll to the discharge side feed roll, and extremely smooth delivery is possible. Further, according to the present invention, when the discharge-side feed roll and the supply-side feed roll are simultaneously conveyed, the discharge-side feed roll is subjected to torque limitation and rotates within the speed range of the supply-side feed roll. Therefore, smooth transportation is not hindered.

[Brief description of drawings]

FIG. 1 is a front view showing in principle the roll feeder according to one embodiment of the present invention, FIG. 2 is a circuit diagram of the roll feeder according to one embodiment of the present invention, and FIG. 3 is one embodiment of the present invention. 6 is a flowchart showing a control operation of the roll feeder according to the present invention. 1 ... Pressing device, 3 ... Supply side feed roll 2 ... Coil material, 4 ... Discharge side feed roll 4n ... Current limiter control terminal

Claims (1)

[Claims] 1. A supply-side feed roll having a release mechanism arranged in front of a processing stage and a discharge-side feed roll arranged in a rear stage of the processing stage and having a release mechanism. In a roll feeder in which each side feed roll is servo-driven, at least the discharge side feed roll is provided with a torque limiting mechanism, and the supply side feed roll, the discharge side feed roll, and the discharge side feed roll torque limiting mechanism. When,
A release mechanism for the feed-side feed roll and a release mechanism for independently controlling the release mechanism for the discharge-side feed roll, and the control means is used to make at least the end of the material the feed-side feed roll. During the period until passing through the rolls, the feed side feed roll and the discharge side feed roll simultaneously convey the material while limiting the torque on the discharge side feed roll, and the end of the material passes through the feed side feed roll. After that, the roll feeder releases the supply-side feed roll, releases the torque limitation of the discharge-side feed roll, and conveys the material by the discharge-side feed roll.