Lifting control method and lifting device of spinning machine

Abstract: When power failure occurs, a lifting drive system is operated by a simple arrangement with a power consumption smaller than that in ordinary operation until the idle rotation of a spindle drive system is approximately stopped. The draft part and spindle drive system is driven by a main motor (M) through a driving shaft (1). The lifting drive system is independent of the draft part and spindle drive system and driven by a first drive motor (19) in ordinary operation and when power failure occurs, it is driven by a second drive motor (28) which can be driven with a power consumption smaller than that of the first drive motor. Electric power is supplied to the second drive motor (28) and a controller (30) from a battery (37) in the power failure and the controller (30) controls the second drive motor (28) until the idle rotation of the spindle drive system is approximately stopped. Yarn is wound around a bobbin in the state that it does not cause a hindrance when a spinning machine is restarted and the rewinding of the yarn in a winder process is not hindered.

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lifting control method and a lifting device of a spinning machine such as a ring spinning frame, a ring twister and the like, and more specifically, to a lifting control method and a lifting device of a spinning machine in which a lifting drive system is driven by a motor different from that used for a roller part and spindle drive system. 2. Description of the Related Art In this type of spinning machines, there is employed a lifting device which gradually lifts a ring rail while repeating the lifting/lowering motion of the ring rail during the operation of the machines and also lifts and lowers a lappet angle and the like accordingly. When filling building is carried out, there is proposed a device arranged such that a lifting drive system is driven by a motor different from that used for a roller part and spindle drive system so that the amount the ring rail is lifted and lowered each time and each winding amount thereof can be easily changed. However, the moment of inertia of the roller part and the spindle drive system is greatly different from that of the lifting drive system and the moment of inertia of the lifting drive system is considerably smaller than that of the spindle drive system. As a result, when the motors of the spindle-drive system and the lifting drive system are simultaneously deenergized due to power failure, the spindle drive system continues its operation for some time after the lifting drive system stops. Thus, since yarn is wound around the same position of a bobbin lengthily, there is a drawback that yarn is often snapped when the spindle drive system and the lifting drive system are restarted and when the yarn is rewound from a bobbin in a winding process, the yarn is rewound in an excessive amount from the portion of the bobbin where it is wound many times at the same portion of the bobbin. To solve this problem, Japanese Examined Utility Model Publication No. 3-48223 discloses a device arranged such that a lifting drive system and a roller part and spindle drive system are driven by independent drive motors as well as both the drive systems are coupled with each other through a clutch by a control mechanism so that the clutch is in a connected state only when power failure occurs. In the device, the lifting drive system is driven by the motor different from that of the draft part and spindle drive system in ordinary operation. When the drive motors of the lifting drive system and the spindle drive system are deenergized due to power failure while a spinning machine is in operation, both the drive systems are coupled with each other through the clutch. Then, both the drive systems are driven in synchronism with each other until they stop even after they are idly driven. Japanese Unexamined Patent Publication No. 60-246826 (corresponding to DE-A- 3412060), which is considered to be the closest prior art, discloses a device arranged such that when power failure occurs in a spinning frame having a draft part drive system, a lifting drive system and a spindle drive system which are driven by different motors, respectively, the respective motors are driven by a back-up power supply and the respective drive systems are stopped in a synchronized state. In addition, the publication also discloses a device arranged such that the motor of the spindle drive system therein is idly rotated and the motors of the other drive systems are driven by the back-up power supply. Japanese Unexamined Patent Publication No. 62-215022 discloses a method for a spinning frame having a spindle drive system, a draft part drive system, a lifting drive system which are driven by different motors, respectively, wherein the respective drive systems are stopped in synchronism with each other using the regenerative power of the drive motor of the spindle drive system which has a large amount of moment of inertia in power failure. In the device disclosed in Japanese Examined Utility Model Publication No. 3-48223, a transmission mechanism is required to transmit the rotational force of the motor of the spindle drive system to the lifting drive system by coupling the spindle drive system with the lifting drive system in power failure. Since a large amount of speed reduction is necessary to transmit the rotation of the spindle drive system to the lifting drive system, a speed reduction mechanism occupies a large space. As a result, the transmission mechanism for connecting the spindle drive system to the lifting drive system in power failure must be disposed to the side of a gear end, by which the degree of freedom in layout of the device is reduced. On the other hand, in the device disclosed in Japanese Unexamined Patent Publication No. 60-246826, the above drawback is not caused because the respective motors are energized by the back-up power supply in power failure and the respective drive systems are stopped in synchronism with each other. However, the device has a problem that since a back-up power supply of large capacity is necessary to drive the motor of the spindle drive system and the motor of the lifting drive system, the size of the back-up power supply is increased and a cost is increased. Further, when the regenerative power of the drive motor of the spindle drive system disclosed in Japanese Unexamined Patent Publication No. 62-215022 is used, there is a problem that control is difficult. SUMMARY OF THE INVENTION A main object of the present invention made taking the above problems into consideration is to provide a lifting, control method and a lifting device of a spinning machine in which a lifting drive system is driven by a motor different from that of a roller part and spindle drive system, the method and device permitting the lifting drive system to be operated by a simple arrangement with a power consumption smaller than that required in ordinary operation until the idle rotation of the spindle drive system is stopped or approximately stopped. Another object of the present invention is to precisely drive the motor for driving the lifting drive system by simple control. To achieve the above objects, one aspect of the invention provides a lifting control method of a spinning machine in which a lifting drive system is driven by a motor different from that of a roller part and spindle drive system, the method comprising providing a first drive motor and a second drive motor which can be driven with a power consumption smaller than that of the first drive motor with the lifting drive system, driving the lifting drive system by the fist drive motor in ordinary operation, and driving the lifting drive system by the second drive motor using a back-up battery as a power supply in power failure until the idle rotation of the spindle drive system is stopped or approximately stopped. According to the lifting control method, the lifting drive system is driven in the ordinary operation by the first drive motor using the electric power supplied from an ordinary power supply. When power failure occurs during the operation, the spindle drive system is idly operated and the lifting drive system is driven by the second drive motor which is energized by the back-up battery until the idle rotation of the spindle drive system is stopped or approximately stopped. The second drive motor is driven with a power consumption (electric power consumption) smaller than that of the first drive motor. According to another aspect of the invention, there is provided a lifting device of a spinning machine in which a lifting drive system is driven by a motor different from that of a roller part and spindle drive system, the lifting device comprising a first drive motor for driving the lifting drive system in ordinary operation, a second drive motor capable of driving the lifting drive system with a power consumption smaller than that of the first drive motor, control means for controlling the second drive motor in power failure until the idle rotation of the spindle drive system is stopped or approximately stopped, power failure detecting means for detecting the occurrence of power failure and outputting a power failure detecting signal to the control means and a battery for energizing the second drive motor and the control means in power failure. According to the above lifting device, the drive motors for driving the respective drive systems are driven by electric power supplied from an ordinary power supply in the ordinary operation and the lifting drive system is driven by the first drive motor. When power failure occurs, a power failure detecting signal is output from the power failure detecting means to the control means. When the power failure occurs, electric power is supplied from the battery to the second drive motor and the control means, respectively. The second drive motor is controlled by the control means until the idle rotation of the spindle drive system is stopped or approximately stopped and the lifting drive system is driven by the second drive motor. The second drive motor is driven with a power consumption smaller than that of the first drive motor used in the ordinary operation. According to the invention described above in detail, the lifting drive system can be operated in power failure by a simple arrangement with a power consumption smaller than that in ordinary operation until the idle rotation of a spindle drive system is stopped or approximately stopped. Further, the degree of freedom in layout of the lifting device is increased. It is preferable that the lifting device further includes operation detecting means for detecting operating state of the spindle drive system and generating an output signal showing the operating state, wherein the control means controls the second drive motor in response to the output signal from the operation detecting means. With this arrangement, the lifting drive system can be securely driven until the idle rotation of the spindle drive system is stopped or approximately stopped regardless of spinning conditions and the number of rotation of a spindle in the occurrence of power failure. It is preferable that the lifting device further comprises position detecting means for detecting the position of the ring rail, the second drive motor is composed of a reversible motor and the control means determines the rotational direction of the second drive motor based on the position of the ring rail in power failure detected by the position detecting means. Thus, the second drive motor is driven in rotation in the determined direction until the idle rotation of the spindle drive system is stopped or approximately stopped and a ring rail is stopped within a predetermined lifting/lowering region. As a result, the snap of yarn can be prevented when the spinning machine is restarted after power failure is recovered and a bobbin can be formed in the state that the rewinding of yarn is not hindered in a winding process. The operation detecting means may be composed of a rotary encoder or a tachometer generator disposed to the drive means of the roller part/spindle drive system. The battery may be connected to an AC power supply through a charger or to a power supply unit to which a charging circuit is assembled. Further, it is preferable that the second drive motor is composed of a DC motor rotatable only in one direction and the lifting drive system includes direction switching means disposed on the side of the output shaft of the DC motor which can optionally change the moving direction of the ring rail under the control of the control means. Further, it is preferable that the first drive motor for driving the lifting drive system, the drive means for driving the roller part/spindle drive system and the control means are disposed to any one of the out end and the gear end and the control means also controls the drive means and the first drive motor in addition to the second drive motor. When the drive motor, the drive means and the control means are disposed as described above, the interval at which the motor for the lifting drive system and the control means thereof are disposed is greatly reduced as compared with the case that they are disposed on the opposite side of the spinning machine. When the lifting motor is feedback controlled, since it is difficult for a disturbance to be mixed with the lifting motor control signal output from the control means and the signals input to the control means for notifying the operating states of the spindle drive system and the lifting drive system, the lifting drive system can be precisely driven. It is preferable that the roller part drive system, the spindle drive system and the lifting drive system are driven by respective different drive means disposed to any one of the out end and the gear end. With this arrangement, the number of components disposed to the other side end (usually, gear end) of the spinning machine is greatly reduced so that the spinning machine can be made compact. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic perspective view of a driving system of an embodiment; FIG. 2 is a block diagram showing the electrical arrangement of a controller; FIG. 3 is a flowchart showing operation in power failure; FIG. 4 is a schematic view showing the shape of a bobbin while it is in a winding process; FIG. 5 is a partial schematic perspective view of a drive system of a modification; FIG. 6 is a schematic view of a spinning frame to which the drive system of FIG. 1 is assembled; FIG. 7 is a partial schematic perspective view of the drive system according to another modification; and FIG. 8 is a schematic view of a ring spinning frame to which the drive system of FIG. 7 is assembled. DESCRIPTION OF THE PREFERRED EMBODIMENTS Now, an embodiment of the present invention, which is embodied in a ring spinning frame including a lifting device arranged to lift and lower a ring rail and a lappet angle by forward and rearward rotating a line shaft will be described with reference to FIG. 1 to FIG. 4. As shown in FIG. 1, a driving shaft 1 extending in the lengthwise direction of a spinning frame main body (not shown) is driven in rotation by a main motor M through a belt transmission mechanism 2 and spindles 3 (only one of them is shown) are driven in rotation through a spindle tape 5 stretched between it and a chin pulley 4 fixed to the driving shaft 1. The main motor M is composed of a variable speed motor driven through an inverter 6 and provided with a rotary encoder 7 as means for detecting operation of a spindle drive system. The rotary shaft 8a of front rollers 8 constituting a draft part or a roller part is coupled with the driving shaft 1 through a gear train 9a. A draft part driving system is composed of the main motor M, the belt transmission mechanism 2, the driving shaft 1, the gear train 9a and the rotary shaft 8a and a spindle drive system is composed of the main motor M, the belt transmission mechanism 2, the driving shaft 1, the chin pulley 4 and the spindle tape 5. That is, the draft part driving system and the spindle drive system are driven by the common main motor M. Note, although the draft part and the spindles 3 are disposed on both the right and left sides of the spinning frame main body, FIG. 1 shows those disposed on only one side thereof. A line shaft 10 (shown only that disposed on one side) is rotatably disposed along the lengthwise direction of a spindle rail (not shown), that is, in parallel with the driving shaft 1. The line shaft 10 includes lifting/ lowering units 13 (only one of them is shown) disposed at predetermined intervals for lifting/lowering the ring rail 11 and the lappet angle 12, respectively. The lifting/lowering unit 13 includes a screw gear 14 fixed to the line shaft 10 so as to rotate integrally therewith and nut bodies 16 to be threaded with the screw portions 15a formed on the lower portions of porker pillars 15 which support the ring rail 11 or the lappet angle 12. The porker pillars 15 are supported by a machine frame (not shown) so that it can move upward and downward. The nut bodies 16 are rotatably supported at a predetermined height of the machine frame through brackets (not shown) and have screw gears 16a formed to the outer peripheries thereof integrally therewith so as to be meshed with each other. Each two of the porker pillars 15 supporting the ring rail 11 or the lappet angle 12, are disposed adjacent to each other, the screw gears 16a of the nut bodies 16 disposed in correspondence to the respective porker pillars 15 are meshed with each other and one of the screw gears 16a is also meshed with the screw gear 14. Note, the above arrangements are substantially the same as those of the device disclosed in, for example, Japanese Unexamined Patent Publication No. 2-277826. A rotary shaft 17 constituting a line shaft drive system is rotatably disposed in parallel with both the line shafts 10 and a gear 18 is fixed to it so as to rotate integrally therewith. The gear 18 is meshed with a gear 20 fixed to the output shaft 19a of a first drive motor 19 so as to rotate integrally therewith. The first drive motor 19 is composed of an AC servo motor which is driven by a commercial AC power supply. A rotary shaft 21 is disposed at a position corresponding to the ends of both the line shafts 10 perpendicularly thereto. The rotary shaft 21 has worms 23 fixed to both the ends thereof so as to rotate integrally therewith and the worms 23 are meshed with worm wheels 22 fixed to the ends of the line shafts 10 so as to rotate integrally therewith. The rotary shaft 17 has a bevel gear 24 fixed thereto so that it is rotated integrally with the rotary shaft 17 and the bevel gear 24 is meshed with a bevel gear 25 fixed to the rotary shaft 21 at an intermediate portion thereof so as to rotate integrally therewith. An absolute type rotary encoder 26 as ring rail detecting means is coupled with an end of the line shaft 10 through gears. The line shaft 10 is rotate forward and rearward by the forward/rearward rotation of the first drive motor 19. The line shaft drive system is composed of the rotary shafts 17, 21, the gears 18, 20, the worm wheels 22, the worms 23, the bevel gears 24, 25 and the drive motor 19. A lifting drive system for lifting/lowering the ring rail 11 and the lappet angle 12 is composed of the line shafts 10, the lifting/lowering unit 13 and the line shaft drive system. The lifting drive system is provided with a gear 27 to be meshed with the gear 18. The gear 27 is supported by the output shaft 28a of a second drive motor 28 through an electromagnetic clutch 29 constituting control means so that it is rotated integrally with the motor 28. The power consumption (amount of electric power consumed) of the second drive motor 28 is smaller than that of the first drive motor 19. In the embodiment, the second drive motor 28 is composed of a DC geared-motor capable of rotating forward and rearward. The electric power consumed by the first drive motor 19 is about several hundreds of watts when the motor carries out an ordinary lifting motion and it is about one kilowatt when it lifts the ring rail 11 at a high speed. On the other hand, the electric power consumed by the second drive motor 28 is about several tens of watts. The electromagnetic clutch 29 is arranged to connect the gear 27 to the output shaft 28a in a magnetized state. An electrical arrangement for driving the above drive systems will be described with reference to FIG. 2. Note, in FIG. 2. lines without arrow show power supply cables and the lines with arrows show signal cables. The first drive motor 19 is controlled by a controller 30 constituting control means through a servo driver 31. The main motor M is controlled by the controller 30 through the inverter 6. An input device 32 is connected to the controller 30. The first drive motor 19 includes a rotary encoder 33 as ring rail detecting means for detecting the position of the ring rail 11. The main motor M is connected to a power supply unit 34 through the inverter 6 and the first drive motor 19 is connected thereto through the servo driver 31, respectively. The power supply unit 34 supplies commercially available, electric power (for example, AC 400) to the inverter 6 without transforming its voltage and AC 200V obtained by transforming the voltage of the above electric power through a transformer is supplied to the servo driver 31. The power supply unit 34 includes an AC/DC converter 35 for converting the commercially available electric power to a direct current of low voltage (24 V in this embodiment). A power supply switching unit 36 is connected to the DC output terminal of the power supply unit 34 and a back-up battery 37. The second drive motor 28, the electromagnetic clutch 29, the controller 30 and the rotary encoders 7, 26, 33 are connected to the output terminal of the power supply switching unit 36. The power supply switching unit 36 includes a power failure detecting means 38 so that it can be switched to the state that it supplies the DC power from the power supply unit 34 to a load when no power failure occurs and to the state that it supplies the DC power from the battery 37 to the load when power failure occurs. The power failure detecting means 38 detects the DC voltage supplied from the power supply unit 34 and outputs a power failure detecting signal when the voltage drops below a set value. The power supply switching unit 36 switches the power supplies by a relay based on the power failure detecting signal from the power failure detecting means 38. The power failure detecting signal is also supplied to the controller 30. The battery 37 is composed of a reversible battery having the same electromotive force as the DC voltage of the power supply unit 34 and connected to an AC power supply through a charger 39 as a charging circuit. The controller 30 includes a central processing unit (hereinafter, referred to as CPU) 40 as control means and arithmetic operation means. The controller 30 includes a program memory 41 as memory means, a working memory 42 as memory means, an input interface 43, an output interface 44, a main motor drive circuit 45 and motor drive circuits 46, 47. The CPU 40 is connected to the input device 32, the rotary encoders 7, 26, 33 and the power failure detecting means 38 through the input interface 43, respectively. The CPU 40 is connected to the inverter 6 through the output interface 44 and the main motor drive circuit 45 and to the servo driver 31 through the output interface 44 and the motor drive circuit 46, respectively. The CPU 40 is connected to the second drive motor 28 through the output interface 44 and the motor drive circuit 47 and to the electromagnetic clutch 29 through the output interface 44 and a clutch magnetizing/demagnetizing circuit 48, respectively. The CPU 40 operates based on the predetermined program data stored in the program memory 41. The program memory 41 is composed of a read only memory (ROM) which stores the above program data and various types of data necessary to the execution of the program data. The working memory 42 is composed of a random access memory (RAM) which temporarily stores data input from the input device 32, the result of arithmetic operation executed in the CPU 40 and the like. The input device 32 includes key switches through which spinning conditions such as the number of revolution of the spindle, a spinning length, a lift length, a chase length and the like in spinning operation are input. Further, also input from the input device 32 is the reference position LS of the ring rail 11 which is used to determine the rotational direction of the second drive motor 28 in power failure. The CPU 40 calculates the position of the ring rail 11 based on the signal output from the rotary encoder 26 when the spinning frame starts up and thereafter calculates the amount of movement and position of the ring rail 11 based on the signal output from the rotary encoder 33. That is, although the absolute type rotary encoder 26 is used to confirm the position of the ring rail 11 when the spinning frame starts up, it is not used in operation. In ordinary operation, the CPU 40 calculates the timing at which the ring rail 11 is reversed which serves as the lifting condition input through the input device 32 based on the amount of movement and position of the ring rail 11 and controls the first drive motor 19 through the servo driver 31 so that the ring rail 11 and the like execute a predetermined lifting/lowering motion. The CPU 40 determines the rotational direction of the second drive motor 28 based on the position of the ring rail 11 when power failure occurs. That is, the CPU 40 outputs a control signal for rotating the second drive motor 28 so that the lifting drive system is driven in the direction to lower the ring rail 11 when the position of the ring rail 11 is above the reference position at the time of power failure and in the direction to lift the driving shaft 11 when the position of the ring rail 11 is below the reference position. When a power failure detecting signal is input to the CPU 40 from the power failure detecting means 38, the CPU 40 outputs a signal for magnetizing the electromagnetic clutch 29 as well as a signal for controlling the second drive motor 28. When the idle rotation of the spindle drive system is approximately stopped, the CPU 40 stops the magnetization of the electromagnetic clutch 29 and the drive of the second drive motor 28 based on the signal output from the rotary encoder 7. Next, operation of the device arranged as described above will be explained. First, spinning condition data such as the number of rotation of the spindle, the spinning length, the chase length and the like in spinning operation is input through the input device 32 prior to the operation of the spinning frame. Further, the reference position data of the ring rail 11 necessary to determine the rotational direction of the second drive motor 28 in power failure is input through the input device 32. Employed as the reference position L s is, for example, the lower limit position of the region of a bobbin 49 where yarn is not wound to its reduced-diameter portion 51 under its barrel portion 50 shown in FIG. 4 when the ring rail 11 is lowered from the reference position in the occurrence of power failure. Then, when the spinning frame is started, the main motor M and the first drive motor 19 are driven in response to a command from the controller 30. When the first drive motor 19 is driven, the line shafts 10 are rotated through the rotary shafts 17, 21, the worms 23 and the like, so that the nut bodies 16 are rotated through the screw gears 14. Then, the porker pillars 15 meshed with the nut bodies 16 are lifted or lowered to thereby lift or lower the ring rail 11 and the like. When the first drive motor 19 is driven forward, the ring rail 11 and the like are moved upward, whereas when it is driven rearward, they are moved downward. Yarn fed from the front rollers 8 is wound around a bobbin through a snell wire and a traveler. The CPU 40 calculates the position of the ring rail 11 when the spinning frame starts based on the signal output from the rotary encoder 26 and corrects the reference position of the rotary encoder 33 based on the value of the calculated position. Then, the CPU 40 calculates the amount of movement and position of the ring rail 11 based on the signal output from the rotary encoder 33 mounted on the first drive motor 19 during operation. The CPU 40 controls the first drive motor 19 through the servo driver 31 so that the rotational direction thereof is changed when the ring rail 11 moves a distance corresponding a previously input lifting or lowering amount per chase. When power supply to the power supply unit 34 is interrupted during operation by an abnormal situation such as power failure or the like, the main motor M, the first drive motor 19 and the like are deenergized and they are idly rotated. When the power supply to the power supply unit 34 is interrupted, the power supply switching unit 36 is operated based on the power failure detecting signal from the power failure detecting means 38 so that the electric power supplied to the second drive motor 28, the electromagnetic clutch 29, the controller 30 and the rotary encoders 7, 26, 33 is switched to the battery 37. Since the battery 37 is sufficiently charged through the charger 39 while electric power is supplied thereto without the occurrence of power failure, the electric power required by the second drive motor 28, the controller 30 and the like in power failure can be securely supplied thereto. Therefore, the second drive motor 28, the electromagnetic clutch 29, the controller 30 and the rotary encoder 7, 26, 33 normally function in power failure. Next, a procedure for controlling the lifting drive system in power failure will be explained according to the flowchart of FIG. 3. When a power failure detecting signal is input from the power failure detecting means 38, the CPU 40 controls the second drive motor 28 and the electromagnetic clutch 29 according to a stop due to power failure program. That is, the CPU 40 calculates the position L 0 of the ring rail 11 in the occurrence of power failure based on the signal output from the rotary encoder 33 at step S1 and magnetizes the electromagnetic clutch 29 at step S2. Next, the CPU 40 compares the position L 0 of the ring rail 11 in the occurrence of power failure with the reference position L s at step S3. Then, when the position L 0 of the ring rail 11 is higher than the reference position L s (L 0 > L s ), the process goes to step S4 and outputs a control signal for lowering the ring rail 11 to the servo driver 31 and when the position L 0 of the ring rail 11 is equal to or lower than the reference position L s (L 0 ≦ L s ), the CPU 40 goes to step S5 and outputs a control signal for lifting the ring rail 11 to the servo driver 31, respectively. As a result, the ring rail 11 is moved by the second drive motor 28 in a predetermined direction at a speed slower than that in ordinary operation. Next, the CPU 40 determines the operating state of the draft part and spindle drive system, that is, the idly rotational state thereof based on the signal output from the rotary encoder 7. More specifically, the CPU 40 calculates the idly rotational speed of the spindle drive system at step S6 and determines whether the idly rotational speed is equal to or less than a predetermined speed or not at step S7. The idle rotation of the spindle drive system is gradually reduced and the spindle drive system will be stopped soon. The CPU 40 goes to step S8 when the spindle drive system is approximately stopped, that is, when the idly rotational speed calculated at step S6 is made lower than the predetermined speed and outputs a signal for stopping the second drive motor 28 as well as outputs a signal for demagnetizing the electromagnetic clutch 29 and finishes a series of control. As a result, the driving force to the lifting drive system is shut off to thereby stop the system and the spindle drive system is also stopped a little later. Although the spindle drive system is stopped a little later after the lifting drive system is stopped, since the spindle 3 rotates less than until the spindle drive system is stopped after the lifting drive system is stopped, there is no difficulty even if the lifting drive system is stopped prior to the spindle drive system. Since a period of time during which the idle rotation of the spindle drive system is continued in power failure is different depending upon the spinning conditions and since the second drive motor 28 is driven at a given speed, the distance the ring rail 11 moves during the time is also different depending upon the spinning conditions. In the arrangement that the ring rail 11 simply continues to move in a given direction from the occurrence of power failure, the ring rail 11 may move up to a position which exceeds the yarn winding region of the bobbin 49 depending upon the spinning conditions and the position of the ring rail 11 in the occurrence of power failure. As a result, hindrance is caused when the spinning frame is restarted after the power failure is recovered or when yarn is rewound in a winder process. For example, when power failure occurs in the vicinity of the lifting end position of the ring rail 11 when the 80% or more wound bobbin 49 is processed in the condition that the moving direction of the ring rail 11 is limited to a lifting direction, the ring rail 11 may move upward of a top punch winding position when doffing is stopped. In addition, a disadvantage occurs when power failure occurs in the state that yarn is wound in a small amount in the condition that the moving direction of the ring rail 11 is limited to a lowering direction. That is, when power failure occurs at the time yarn is wound in a very small amount and the ring rail 11 is located at a position near to its lowering end, the ring rail 11 may move downward of the yarn winding region of the bobbin 49. Further, as shown in FIG. 4, the bobbin 49 formed by filling building has the reduced-diameter portion 51, where its diameter is reduced downward, formed under the so-called the barrel portion 50 where a portion of predetermined diameter is continuously formed. Therefore, even after a certain amount of wound yarn is secured, when power failure occurs at the time the length of the barrel portion 50 of the bobbin 49 is short, the ring rail 11 may move to a position corresponding to the reduced-diameter portion 51 under the barrel portion 50 and yarn may be wound around the reduced-diameter portion 51. When the yarn is wound around the reduced-diameter portion 51 after the formation of the barrel portion 50, the yarn is often difficult to be rewound in a winder process. According to the embodiment, however, since the rotational direction of the second drive motor 28, that is, the moving direction of the ring rail 11 in power failure is determined based on the position of the ring rail 11 when the power failure occurs, the yarn which is wound around the bobbin 49 while the idle rotation of the spindle drive system continues in the power failure is securely wound to a position where the above disadvantage is not caused. When the power failure is recovered, the CPU 40 calculates the position of the ring rail 11 from the rotary encoder 26. When the position where the ring rail 11 stops is outside of the chase in the occurrence of the power failure, the CPU 40 controls the first drive motor 19 to continue the lifting/lowering motion interrupted by the occurrence of the power failure after the ring rail 11 is moved to the position where it is reversed to a lifting motion in the chase motion next to the chase motion when the power failure occurs. When the position where the ring rail 11 stops is inside of the chase in the occurrence of the power failure, the CPU 40 controls the first drive motor 19 to continue the lifting/lowering motion interrupted by the occurrence of the power failure after the spinning frame is restarted. This embodiment has the following effects: (a) There is used the second drive motor 28 whose power consumption is smaller than that of the first drive motor 19 for driving the lifting drive system in ordinary operation and which is driven by the back-up battery 37 as the drive source for driving the lifting drive system in power failure. Therefore, the mechanism is simplified as compared with the case that a rotation transmission mechanism is interposed between the lifting drive system and the spindle drive system. As a result, since it is easy to dispose the first drive motor 19 serving as the drive source of the lifting drive system and the second drive motor 28 to the out end side of the spinning frame in addition to the gear end side thereof, the degree of freedom in layout of the lifting device is increased; (b) Since the second drive motor 28 is deenergized in power failure a little before the idle rotation of the spindle drive system is completely stopped, a power consumption is reduced as compared with the case that the second drive motor is stopped by the stop of the idle rotation of the spindle drive system; (c) Since the idle rotation of the spindle drive system is determined based on the signal output from the rotary encoder 7 as the spindle drive system operation detecting means disposed to the main motor M, the lifting drive system can be simply and securely stopped a little before the idle rotation of the spindle drive system is stopped regardless of the spinning conditions and the rotational speed of the spindle in the occurrence of power failure. Further, since the rotational speed of the motor used in power failure can be changed regardless of the rotational speed of the spindle, it can be set faster when thick yarn is spun and slower when thin yarn is spun; (d) Since the second drive motor 28 can be driven forward and rearward, the rotational direction thereof can be determined based on the position of the ring rail 11 when power failure occurs. As a result, the yarn wound while the spindle drive system is idly rotated is wound around the bobbin 49 in such a manner that the yarn is prevented from being snapped when the spinning frame is restarted and no hindrance is caused when the yarn is rewound in a winder process regardless of the amount of the yarn wound around the bobbin 49; (e) Employed as the reference position for determining the rotational direction of the second drive motor 28 is the lower limit position of the region of the bobbin 49 where yarn is not wound to the reduced-diameter portion 51 thereof when the ring rail 11 is lowered from the reference position in the occurrence of power failure. Therefore, the ring rail 11 is often located on the upper side of the reference position in power failure. As a result, the second drive motor 28 often drives the lifting drive system in the direction for lowering the ring rail 11, by which power consumption can be reduced. (f) Since the battery 37 is connected to the AC power supply through the charger 39, it can be sufficiently charged therethrough while electric power is supplied thereto without the occurrence of power failure, so that the electric power required by the second drive motor 28, the controller 30 and the like in power failure can be securely supplied; and (g) Since the geared motor is used as the second drive motor 28, the arrangement can be made compact as compared with the case that a speed reduction mechanism is interposed between the motor and the rotary shaft 17. Note that the present invention is not limited to the above embodiment, but may be embodied, for example, as described below: (1) The second drive motor 28 may be stopped simultaneously with the stop of the idle rotation of the spindle drive system. In this case, the same effects as those of the above embodiment can be achieved except the item (b); (2) The second drive motor 28 is stopped after a predetermined period of time from the output of a power failure detecting signal in place of that the timing at which the motor is stopped is determined based on the signal output from the rotary encoder 7 mounted on the main motor M. The predetermined period of time is determined based on the spinning conditions and the rotational speed of the spindle in the occurrence of power failure. In this case, the operating state of the spindle drive system need not be detected after the control of the second drive motor 28 is started; (3) The reference position for determining the rotational direction of the second drive motor 28 may be located between the lower limit position of the region of the bobbin 49 where yarn is not wound around the reduced-diameter portion 51 of the bobbin 49 when the ring rail 11 is moved downward from the reference position and the upper limit position where the yarn does not exceeds the winding region of the bobbin 49 when the ring rail 11 is moved upward from the reference position; (4) The second drive motor 28 may be driven to continue the chase motion before the occurrence of power failure in place of the arrangement that the rotational direction of the second drive motor 28 in the occurrence of power failure is determined by comparing the position of the ring rail 11 when the power failure occurs with the reference position and the ring rail 11 is moved in a given direction until it is stopped. In this case, since the ring rail 11 is moved to keep the predetermined chase motion except that the moving speed thereof is reduced, the reference position need not be input as well as the ring rail 11 need not be moved up to a predetermined position when the operation of the spinning frame is resumed after the power failure is recovered; (5) An unreversible DC motor is used as the second drive motor 28 in replace of the reversible DC motor and two sets of gear trains 52, 53 for a lifting motion and a lowering motion are interposed between the second drive motor 28 and the rotary shaft 17 as shown in FIG. 5. The lifting gear train 52 is composed of the gear 18 and the gear 27 in the above embodiment and the lowering gear train 53 is newly added. The rotational force of the output shaft 28a is transmitted to the gear train 53 through an electromagnetic clutch 54. This device is arranged such that when only the electromagnetic clutch 29 is magnetized in power failure, the rotary shaft 17 is driven in the direction for lifting the ring rail 11 through the gear train 52, whereas when only the electromagnetic clutch 54 is magnetized, the rotary shaft 17 is driven in the direction for lowering the ring rail 11 through the gear train 53. Therefore, even if the second drive motor 28 is composed of the unreversible motor, since the moving direction of the ring rail 11 can be optionally changed by controlling the magnetization/demagnetization of the electromagnetic clutches 29, 54 by the controller 30, the control of the above embodiment and the item (4) can be realized in power failure; (6) The ring rail 11 is permitted to move in any one direction of a lifting direction and a lowering direction in power failure in place of the arrangement that it can be moved in any direction of the lifting direction and the lowering direction. Then, when the ring rail 11 reaches the boundary of the predetermined winding region of the bobbin 49, the second drive motor 28 is stopped even if the idle rotation of the spindle drive system is not approximately stopped. In this case, a power consumption is reduced by driving the second drive motor 28 in the direction for lowering the ring rail 11; (7) A so-called spring-close type electromagnetic clutch may be used as the electromagnetic clutch 29 in the embodiment to connect the output shaft 28a to the gear 27 in power failure and disconnect the output shaft 28a from the gear 27 when electric power is supplied. In this case, since the electromagnetic clutch 29 is automatically connected simultaneously with the occurrence of power failure, the electromagnetic clutch 29 need not be magnetized by the battery 37, by which the battery 37 is less consumed; (8) A DC servo motor may be used as the first drive motor 19 in place of the AC servo motor and a servo driver corresponding to it may be used. Further, a variable speed motor whose speed is changed by an inverter may be used in place of the servo motor as well as a mechanism for changing the rotational direction of the line shaft 10 by the magnetization/demagnetization of a pair of electromagnetic clutches may be disposed. Further, a constant speed motor may be used as the main motor M; (9) The rotary encoder as the spindle drive system operation detecting means for detecting the operating state of the spindle drive system may be mounted to a position which is rotated in synchronism with the main motor M such as, for example, the driving shaft 1 in place of the main motor M. In addition, a tachometer generator may be mounted in placed of the rotary encoder. When the tachometer generator is mounted, since a pulse signal is output in proportion to the number of rotations without the need of the back-up by electric power different from the case that the rotary encoder is used, wiring can be simplified. Further, a dog may be disposed to a portion which is rotated by the main motor to detect the rotation of the dog by a proximity switch. (10) A motor using a voltage different from that used by the controller 30 may be used as the second drive motor 28 and the controller 30 and the second drive motor 28 may use a different battery. Further, the battery 37 is not connected to the AC power supply through the charger 39 but may be replaced with a charged battery when an amount of charge is reduced below a predetermined value; (11) The power failure detecting means 38 may be disposed to a position where it can detect that the power supply to the power supply unit 34 is interrupted or a position where it can detect that the power supply to the main motor M or the first drive motor 19 is interrupted in place of that it is disposed to the power supply switching unit 36; (12) Means other than the rotary encoder may be used as the position detecting means of the ring rail 11. For example, there may be employed a device arranged such that a so-called magnet scale having a multiplicity of permanent magnets with the N-poles and the S-poles thereof disposed alternately is disposed in the vicinity of the lifting/lowering range of the ring rail 11 as well as the detecting portion of the magnet scale is fixed so as to be movable integrally with the ring rail 11. Further, a linear potentiometer may be used as the position detecting means. The rotary encoder may be mounted at any suitable position so long as it is a part rotatable in synchronism with the rotation of the line shaft 10; (13) A charging circuit may be assembled to the power supply unit 34 in place of the provision of the charger 39 so that the battery 37 can be charged through the charging circuit; and (14) The spindle 3 may be driven by a tangential belt in place of the arrangement that it is driven by the spindle tape 5 stretched around the chin pulley 4. Further, the device may be applied to a ring twister. Next, the disposition of the main elements described in relation to FIG. 1 and FIG. 2 will be described with reference to FIG. 6. A main motor M for driving a draft part and spindle drive system and a lifting motor 19 for driving a lifting drive system are disposed on the side of the out end 61 of a spinning frame main body 60 as one of the ends thereof. A controller 30 as control means for controlling the main motor M and the lifting motor 19 is disposed to the out end 61. A rotary shaft 8a as shown in FIG. 1 is coupled with a driving shaft 1 through a gear train 9a disposed on the side of the gear end 62 of the spinning frame main body 60 as the other end thereof as described above. Further, the rotation of the rotary shaft 8a is transmitted to a middle bottom roller and a back bottom roller (both not shown) which constitute the draft part through a gear train 9b (shown in FIG. 6). Likewise the controller 30 shown in FIG. 1 and FIG. 2, a controller 30 includes a central processing unit 40 (hereinafter, referred to as a CPU) 40 as control means and arithmetic operation means, memory devices 41, 42 and input/output interfaces 43, 44 and controls the main motor M, the lifting motor 19, a motor 28 used in power failure, an electromagnetic clutch 29 and the like according to a program stored in the memory device. An input device 32 for inputting spinning conditions and the like is connected to the controller 30. Signals output from rotary encoders 7, 33, 26 and power failure detecting means 38 (see FIG. 2) are input to the controller 30. The above embodiment has the following effects: (a) Since the main motor M, the lifting motor 19 and the controller 30 for controlling both the motors M and 19 are disposed to the same end (out end 61) of the spinning frame main body 60, the wiring for sensing a signal necessary to feed-back control the lifting motor 19 can be shortened. As a result, since it is difficult for a disturbance to be mixed with the signal output from the controller 30 to control the lifting motor 19 and with the signals input to the controller 30 to notify the operating state of the spindle drive system and the lifting drive system (output from the rotary encoders 7, 33, 26), the lifting drive system can be precisely driven by a simple control. Further, since wirings connecting the out end 61 to the gear end 62 are reduced, a manpower for assembly is reduced to thereby lower a manufacturing cost; and (b) Since the motor 28 used in power failure, the electromagnetic clutch 29 and a battery 37 are disposed on the same side end as the controller 30, necessary wirings are shortened and a control accuracy is improved as well as since the number of wirings is reduced, a manpower for assembly is decreased to thereby lower a manufacturing cost. Next, a modification of the embodiment will be described with reference to FIG. 7. The modification is different from the above embodiment in that coutermeasure means against power failure which is different from that of the above embodiment is disposed on a gear end side. Therefore, the modification also has the effect of the above item (a). Note, although elements 6, 30, 31, 32. 37 etc. are omitted in FIG. 7, the modification includes them likewise. As the countermeasure means against power failure, there is disposed rotation transmission means 70 on the side of a gear end 62 to transmit the rotation of a spindle drive system to a lifting drive system. The rotation transmission means 70 includes a gear transmission mechanism 72 capable of transmitting the rotation of a rotary shaft 71 disposed in parallel with line shafts 10 to both of them (only the line shaft 10 on one side is shown), a rotary shaft 73 to which the rotation of a driving shaft 1 is transmitted through a gear train and a belt transmission mechanism 75 interposed between an end of the rotary shaft 73 and the rotary shaft 71 of a gear transmission mechanism 74. The gear transmission mechanism 74 is coupled with both the line shafts 10 through bevel gears 76, 77 in place of that it is coupled therewith through worms and worm wheels. The belt transmission mechanism 75 transmits the rotation of the rotary shaft 73 to the rotary shaft 71 when an electromagnetic clutch 78 disposed to the rotary shaft is magnetized. The electromagnetic clutch 78 is energized by a battery 37 in power failure and the magnetization/ demagnetization of it is controlled in response to the control signal from a controller 30. Since the electromagnetic clutch 78 is kept to a demagnetized state in an ordinary state (no power failure occurs), the rotation of the spindle drive system is not transmitted to the lifting drive system while a spinning frame is in operation. When power failure occurs, the main motor M and the lifting motor 19 are .idly rotated. The electromagnetic clutch 78 is magnetized in response to the magnetizing signal from the controller 30 and the rotation of the driving shaft 1 is transmitted to the lifting drive system through the rotation transmission mechanism 70. Therefore, while the electromagnetic clutch 78 is kept to the magnetized state, the lifting drive system is driven in synchronism with the spindle drive system and the ring rail 11 is moved in one direction. Thus, there is a possibility that the ring rail 11 moves up to a position which exceeds the winding range of a bobbin while the spindle drive system is idly rotated depending upon the position of the ring rail 11 when the power failure occurs. The controller 30 calculates the position of the ring rail 11 based on the signal output from a rotary encoder 33 and stops the lifting drive system by outputting a demagnetizing signal to the electromagnetic clutch 78 when the ring rail 11 moves up to the limit of the winding range of the bobbin even before the idle rotation of the spindle drive system is approximately stopped. Therefore, yarn is not wound to a position exceeding the winding range of the bobbin while the spindle drive system is idly rotated. Further, since a motor 28 used in power failure is not necessary, a power consumption is reduced. Next, another example of the disposition will be described with reference to FIG. 8. In the disposition, a draft part drive system is driven by a motor different from that of a spindle drive system and the motor for the draft part drive system and the control means thereof are disposed to the same side end (out end 61) as that where a main motor and the like are disposed. There are disposed to the draft part drive system a plurality (two sets in this embodiment) of drive motors for arbitrarily changing a draft ratio, that is, a first draft motor 80 for driving a front bottom roller and a second draft motor 81 for driving a middle bottom roller and other rollers following the middle bottom roller. Both the draft rollers 80, 81 are composed of servo motors which are controlled by a controller 30 through a servo driver (not shown). A rotary encoder (not shown) is provided with each of both the draft motors 80, 81 to feed back the operating state of the draft part drive system. The controller, the spindle drive system and a lifting drive system are arranged likewise those of the embodiment show in FIG. 1 and FIG. 2. As to these elements, refer to FIGS. 1 and 2. There are disposed on the side of a gear end 62 a belt transmission mechanism 82 for transmitting the rotation of a driving shaft 1 to the rotary shaft 8a of the front bottom roller 8 in power failure and a rotation transmission mechanism 83 for transmitting the rotation of the rotary shaft 8a to the middle bottom roller and the other rollers following it in power failure. An electromagnetic clutch (not shown) to be connected in power failure is disposed to each of the belt transmission mechanism 82 and the rotation transmission mechanism 83, so that the rotation of the driving shaft 1 is transmitted to the rotary shaft 8a and the rotation of the rotary shaft 8a is transmitted to the middle bottom roller and the other rollers following it only when the power failure occurs. Therefore, the embodiment can simply change a draft ratio by changing the rotational speed ratio of both the draft motors 80, 81 without the need of the troublesome replacement of a change gear. Both the draft motors 80, 81 are controlled by the controller 30 disposed on out end 61 side likewise other motors. Consequently, since it is difficult for a disturbance to be mixed with the signals output from the controller 30 to control both the draft motors 80, 81 and the feedback signal input to the controller 30, the draft part drive system can be precisely driven by a simple control. In addition, when power failure occurs, since the draft part drive system is connected to the spindle drive system and driven in synchronism with each other until the idle rotation of the spindle drive system is stopped, the snap of yarn caused by the excessive draft of rough yarn can be prevented. Note the present invention is not limited to the above embodiments but may be embodied, for example, as described below. Two sets of lifting and lowering gear trains are interposed between both the rotary shafts 71, 73 as the rotation transmission mechanism 70 disposed on the gear end side as well as an electromagnetic clutch is provided with each of the gear trains. Then, the direction in which the ring rail 11 is moved is determined based on the position of the ring rail 11 in the occurrence of power failure likewise the above embodiment and the electromagnetic clutch corresponding to it is magnetized. In this case, the yarn to be wound during the idle rotation of the spindle drive system is wound around a bobbin in the state that it is prevented from being snapped when the spinning frame is restarted and the rewinding of the yarn in a winder process is not hindered regardless of the amount of yarn which has wound around the bobbin when power failure occurs. There is provided a back-up battery for energizing both the draft motors 80, 81 as means for driving the draft part drive system in synchronism with the spindle drive system in power failure in place of the belt transmission mechanism 82 and the rotation transmission mechanism 83. Then, both the draft motors 80, 81 may be feedback controlled by the controller 30 based on the rotational speed of the spindle drive system in power failure. In this case, since the draft part drive system can be rotated at a draft ratio corresponding to spinning conditions in power failure, no irregularity of thickness is caused to spun yarn. The draft part may be driven by a single draft motor. In this case, although the change of a draft ratio requires the replacement of a change gear, no change gear is necessary to change the number of twists. When power failure occurs, a lifting drive system is operated by a simple arrangement with a power consumption smaller than that in ordinary operation until the idle rotation of a spindle drive system is approximately stopped. The draft part and spindle drive system is driven by a main motor (M) through a driving shaft (1). The lifting drive system is independent of the draft part and spindle drive system and driven by a first drive motor (19) in ordinary operation and when power failure occurs, it is driven by a second drive motor (28) which can be driven with a power consumption smaller than that of the first drive motor. Electric power is supplied to the second drive motor (28) and a controller (30) from a battery (37) in the power failure and the controller (30) controls the second drive motor (28) until the idle rotation of the spindle drive system is approximately stopped. Yarn is wound around a bobbin in the state that it does not cause a hindrance when a spinning machine is restarted and the rewinding of the yarn in a winder process is not hindered.

Claims: A lifting control method of a spinning machine including a lifting drive system, a spindle drive system, means for driving the lifting drive system, and means provided, in addition to the above drive means, for driving the spindle drive system, said method comprising the steps of: providing the drive means of the lifting drive system with a first drive motor (19) and a second drive motor (28) which can be driven with a power consumption smaller than that of said first drive motor (19); driving the lifting drive system by said first drive motor (19) in ordinary operation; and driving, when power failure occurs, the lifting drive system by said second drive motor (28) using a back-up battery (37) as a power supply until the idle rotation of the spindle drive system is stopped or approximately stopped. A lifting device of a spinning frame including an out end located at one end of the spinning frame, a gear end located at the other end thereof, a lifting drive system having a ring rail extending between the out end and the gear end, a spindle drive system extending between the out end and the gear end, means for driving the lifting drive system, and means provided, in addition to said drive means, for driving the spindle drive system: wherein the drive means of the lifting drive system comprises a first drive motor (19) and a second drive motor (28) capable of being driven with a power consumption smaller than that of said first drive motor (19); and wherein the lifting device further comprises power failure detecting means (38) for detecting the occurrence of power failure and outputting a power failure detection signal, control means (30) for controlling said second drive motor (28) in response to the power failure detection signal from the power failure detecting means (38) until the idle rotation of the spindle drive system is stopped or approximately stopped, and a battery (37) for supplying electric power to said second drive motor (28) and said control means (30). A lifting device according to claim 2, further comprising operation detecting means (7) for detecting operating state of the spindle drive system and generating an output signal showing the operating state, wherein said control means (30) controls said second drive motor (28) in response to the output signal from said operation detecting means (7). A lifting device according to claim 2 or 3, further comprising position detecting means (32, 33) for detecting the position of the ring rail (11), wherein said second drive motor (28) is composed of a reversible motor, and said control means (30) determines the rotational direction of said second drive motor (28) based on the position of the ring rail (11) detected by said position detecting means (32, 33) when power failure occurs. A lifting device according to claim 3, wherein said operation detecting means is composed of a rotary encoder (7) disposed to the drive means (M) of the spindle drive system. A lifting device according to claim 3, wherein said operation detecting means is composed of a tachometer generator (7) disposed to the drive means (M) of the spindle drive system. A lifting device according to claim 2, wherein said battery (37) is connected to an AC power supply through a charger (39). A lifting device according to claim 2, wherein said battery (37) is connected to a power supply unit (34) to which a charging circuit is assembled. A lifting device according to claim 2 or 3, wherein said second drive motor (28) is composed of a DC motor rotatable only in one direction and said lifting drive system includes direction switching means (29, 52, 53, 54) disposed on the side of an output shaft (28a) of the DC motor to optionally change the moving direction of the ring rail (11) under the control of said control means (30). A lifting device according to claim 2, wherein said first drive motor (19) for driving the lifting drive system, said drive means (M) for driving the spindle drive system, and said control means (30) are disposed to one of the out end and the gear end, and said control means (30) also controls said drive means (M) and said first drive motor (19) in addition to said second drive motor (28). A lifting device according to claim 10, wherein the spinning machine further includes a roller part drive system and said roller part drive system, the spindle drive system and the lifting drive system are driven by respective different drive means (80, 81; M; 19, 28) disposed in one of the out end and the gear end.

Inventors: NIIMI KIWAMU, TERASHITA MASAHIRO, NIIMI, KIWAMU, TERASHITA, MASAHIRO, NIIMI, KIWAMU, C/O KABUSHIKI KAISHA TOYODA, Terashita, Masahiro, c/o Kabushiki Kaisha Toyoda
Applicants: KK, KABUSHIKI KAISHA
Application year: 1997
Main classification: D01H1
IPC codes: D01H1