KR19990087647A - Drive system - Google Patents

Abstract

The drive system for driving the inertial mass 40 beyond the drive path between the first and second extreme positions comprises electric drive motors 12 and 14, drive motors 12 and 14 in the mass 40 for driving mass, , A storage capacitor (20) for storing power, and a drive motor (20) for accelerating the mass (40) from one of the first and second extreme positions over a first portion of its drive path 12, and 14, respectively. The control means (16, 18) are adapted to drive the motors (12, 14) when the drive motor is actuated to block the electromagnet during the deceleration of the mass (40) over a second portion of its drive path towards the other of the first and second extreme positions, (12, 14) to the storage capacitance (20) used to charge the storage means (20). The monitoring device 22 monitors the energy level stored in the storage means 20 and the control means determines whether the power stored in the storage means 20 exceeds the predetermined level during the acceleration of the mass 40 over the first part of the drive path And power is supplied from the storage means 20 to the drive motors 12, 14.

Description

Drive system

All the operating parts in the machine, such as the loom and knitting machine, are constantly driven by the general drive motor. Where a Jacquard, dobby, tappet device, a cam device in a loom, a yarn carrier and a needle-operated reciprocating machine in a knitting machine (flatbed and round) are used, Power is applied to the loom or machine. Recently, the speed-increasing generation of these types of fabric-forming machines has been limited to their respective high inertial masses. In the past, driving from a single reference AC or DC motor at nominal operating speeds, which allows for a speed reduction to be integrated, has been achieved, and the inertial mass, which is regarded as their motor shaft, is reduced to the square of the reduction ratio . It is required to review the respective inertial masses of the power of the driven device so as to improve the speed parameter in fabric formation and to produce these fabrics in a more economical production rate in a programmable stepwise relationship. As a result, energy consumption is a key variable for productivity gains.

The helmet frame, tappet motion and camming motion, which are driven by weaving for example during weaving, are carried out vertically via mechanical coupling devices by crank motion on a rotating cam or a common shaft, respectively selected by use of a clutch or other power selection device I will make a round trip. When driven by the drive motor, the shape of the cam and / or the crank trajectory path is accelerated from the lowest threshold position of the heddle frame to a rate at which the heddle frame remains over before it begins to decelerate toward the upper threshold position. The handheld frame is decelerated and driven toward the upper position under the action of gravity, accelerated and decelerated, and its stored position and kinetic energy return to the drive shaft with the aid of gravity towards the lowest critical position. The returned energy accelerates another heddle moving from their bottom to the upper metric position. As a result, the drive motor can be a relatively low-power motor.

Typically, the linkage mechanism of the helf frame provides a suitable mechanism with the advantage of allowing the drive motor to use relatively low power. This enables the drive frame to be driven at speeds up to 600 picks per minute. However, the power of the drive motor must be increased significantly in order to increase the speed of the heald frame above the range, so that the system becomes uneconomical. When the linkage is provided more directly to the helmet frame, a considerable amount of power is generated in the drive motor " driven " by the helmet while the end of the stroke of the downwardly biasing operation is decelerated due to inertia of the helmet frame.

Figure 1 is an ideal graph of time versus speed for motion of the heddle frame from its lowest critical position to its uppermost position during a shedding operation. A graph of the repetition motion of the hand frame from its best-order position to its lowest-most position is shown in FIG. This indicates that the maximum power from the drive motor is required for the acceleration period t _a of time t ₀ to t ₁ as an ideal operation chart. When the held frame, the end velocity v accelerated to speed v ₁ required at _zero speed, the held frame, whose center shed (shed), substantially constant for a time t _c to t ₂ from time t ₁ through the position do. Above this period, the energy required by the drive motor drops, and sufficient energy is required to overcome the frictional forces present to maintain the speed of the frame at v ₁ only. Beyond the period t _d of time t ₂ to t ₃ , at which the hand frame reaches its conflicting top position, the velocity drops to zero. In this period or more, the drive motor has an effect of shutting off the electromagnet. Thus, as the handheld frame drives the motor, the power is generated by the motor acting as a generator and the power is usually wasted.

As a result, the accelerations and decelerations of the respective hedge frames are limited due to the inertial stresses of the system, so that the time period from the bottom shed position to the upper shed position becomes longer, so that the acceleration and deceleration time periods t _a , t _d It becomes longer.

The present invention relates to a drive system for driving an inertial mass.

1 is a graph showing the speed versus time for ideal motion of a vibration mass driven along a drive path between two shortest positions.

Fig. 2 is a graph similar to Fig. 1 in which friction and emotional violence are taken into account.

3 is a graphical representation similar to FIG. 1 showing the speed and time for ideal movement of a reciprocating mass, such as the helmet frame of a loom, driven by a preferred form of the drive system according to the invention.

4 is a diagram showing a preferred embodiment of a drive system according to the present invention for a textile machine.

5 is a diagram showing operational steps of a drive system according to the present invention using relative position feedback for drive control.

Fig. 6 is a view similar to Fig. 5 using analog absolute position feedback for drive control.

Figure 7 is a graph similar to Figure 3.

Figure 8 is a graph that is more similar than Figure 3.

It is an object of the present invention to provide an improved drive system for driving an inertial mass.

Thus, the present invention provides:

Electric drive motor;

Coupling means for coupling the mass with the drive motor to drive the mass;

And control means for applying power to the drive motor to accelerate the mass from one of the first and second extreme positions over a first portion of its drive path, Providing a drive system for driving an inertial mass over,

Wherein the control means connects the drive motor to the storage means so that the drive motor

The drive motor charges the storage means when it functions to cut off the electromagnetic force during the deceleration of the mass over a second portion of its drive path toward the other of the first and second shortest positions.

Although the invention can be applied to any inertial mass driven in a vibrational manner, an example of reciprocal motion of an inertial mass such as a heald or a handle frame of a fabric machine is described below.

Referring to the drawings, Fig. 4 shows a drive system 10 for a fabric machine 11. Each heddle in the fabric machine, and / or one or more heddle frames 40 are driven by a motor or an actuator. The linear actuator 12 is shown. A rotary actuator 14 may additionally or alternatively be provided. The form of the actuator can be chosen to suit particular requirements and is not limited to the actuator shown in FIG.

In the preferred embodiment, each handheld frame is driven by itself or by the actuators 12, 14 (although only the handheld frame is described below, the embodiments may equally be applied to a single handheld or a combination of single handheld and handheld frames) . This can significantly reduce the power motor used to directly drive the handheld frame, making the handheld frame relatively light. Since each handheld frame requires only a very low power actuator, you can use an actuator such as a servo motor (which can be accelerated very quickly with the required handheld frame rate) without the need to use a brush. This can reduce both the acceleration and deceleration times for the heald frame to increase the weaving speed.

The control system includes a microprocessor 16 that individually controls the operation of each of the actuators 12, 14 to control the weaving operation according to a pre-selected weaving program. The microprocessor 16 determines the selection and selection time of the hand frame and the movement of the weft. The control signal from the microprocessor passes through the actuator controller 18, which monitors the power drawn by each actuator. Indicates whether or not each actuator (and each hand frame) is accelerated from one of its terminal lowest or highest shed positions. The actuator controller 18 is also connected to a power storage means, preferably in the form of a capacitor 20, and also to a storage monitor 22 and a power controller 24. The power controller 24 controls the power supply from the main feeder.

A DC / AC converter 26 is also provided. Which may be coupled to the storage capacitance 20 and controlled by the microprocessor 16 (or actuator controller 18) to power mains from the storage capacitance 20, if desired.

Each actuator 12, 14 is also provided with a sensor (28) that monitors the position of the actuator (linear or rotational) and the handle frame to provide a signal to the actuator controller 18 indicating the position of the handle frame. The actuator controller 18 may selectively or additionally use a signal from the sensor 28 to indicate whether each controller and associated handheld frame is accelerated or decelerated rather than merely monitoring the power drawn by each actuator .

Figure 5 illustrates the operation of the drive system with reference to the operation of the linear actuator 12. This operation can be equally applied to any other type of actuator.

If the microprocessor 16 departs from a position to provide a desired position signal for the position of the linear actuator 12 (i.e., the associated handheld frame), the signal may be provided to the error calculation logic 100 . Which compares the desired position signal with the actual position signal supplied from storage location 118 to produce a position error signal applied to output select logic circuit 102. [ The linear actuator 12 shown in Figure 5 is a two-phase motor with two coils 104, 106 and drive circuits 108, 109 for the associated coils. Output selection logic 102 controls the drive circuits 108, 110 for driving the coils and moves the actuator and the handle frame to their new position.

Each coil on the actuator 12 associated with a respective position sensor 28 provides a signal representative of the position of the actuator relative to its associated drive coil. Although two sensors are shown here, only one sensor is needed to provide a single position signal. The position change and change rate over time can be used to provide the speed and acceleration of the actuator and the helmet frame.

Each of the signals from the sensors 28 is supplied to a relative Inverted Position Lookup Table 112, 114 that compares the data or reference signal to provide a signal indicative of the absolute position of the actuator 12 and the combined handheld frame. Each of the signals from the comparators 112, 114 compares the position selection logic circuit or comparator 116 to a signal indicative of the previous position of the actuator 12. The comparator 116 consequently generates an error signal, and an error signal is applied to the memory location 118. The storage location 118 stores the current location of the actuator 12 and updates the error signal received at that time. A signal indicative of the previous position of the actuator 12 is held in the logic circuit 120 so that the current position signal is applied from the memory location 118. The logic circuit 120 updates the stored signal indicative of the previous position of the linear actuator to respond to receive the error signal to store the new signal indicative of the current actuator and the position of the hand frame.

Additionally, the logic circuit 120 includes a subtractor for subtracting the difference between the signal indicative of the new position of the actuator, the signal indicative of the previous position, and the pre-selection reference value set by the microprocessor 16. In fact, the circuit monitors the velocity and acceleration of the actuator and the heel frame by monitoring the change in position of the actuator over time and comparing it with a pre-selected reference value. The position signal supplied by the microprocessor 16 to the error calculation logic circuit 100 changes above the rate of change indicative of the movement period of the actuator and the acceleration and deceleration of the actuator and the hedge frame. In fact, the circuit monitors the speed of the actuator and compares the difference comparison of the position signal with the desired speed and pre-selection reference value set by the microprocessor 16 by the time-dependent change of the position signal from the microprocessor 16 .

Depending on the change in the reference value and the signal difference, the comparison indicates the speed and acceleration of the linear actuator 12, and the logic circuit 120 also applies an error signal to the speed calculation circuit 122. It also receives signals from storage 118, which later indicate the current position within the period of the linear actuator and the helmet frame. The speed calculation circuit 122 determines whether the hand frame is maintained at a constant speed, accelerated or decelerated, and provides a final signal to the output selection logic 102 to either accelerate or decelerate the linear actuator at the same rate or according to the actuator .

The position signal from the memory device 118 is also supplied to the polarity and the coil selection circuit 124 determines the direction of movement of the linear actuator 12 and the helmet frame in accordance with the position signal, And applies a directional signal to the output selection logic circuit 102 which moves in the reverse direction and holds the actuator 12. [

Figure 6 shows a simple control system in which a position sensor 28 on the actuator 12 feeds a position signal to the deck 200. This compares the signal with the desired position signal from the microprocessor 16 and supplies the final error signal to the polarity and coil selection circuit 202 and the output is applied to the coil drive circuits 108,110 of the actuator 12 do.

Also, the position signal from sensor 28 is digitized by analog to digital converter 204 and applied to a look-up table 206. Is later pre-programmed with a digital value representing the various absolute positions of the actuator 12 and the connected handheld frame to determine the absolute position of the actuator 12 in comparison with the signal from the converter 204. [ The final directional and velocity signals are applied to the bipolar and coil selection circuit 202 to control the signals supplied to the coils via the output drive circuitry.

Selection reference value is set by the microprocessor 16 and the logic circuit 120 is fixed constantly over a period of time compared to the position difference signal and the movement pattern of the required mass (i. E., The fabric pattern) Can be transformed in a pre-selected manner

The desired position signal is also supplied by the microprocessor 16 to the error calculation logic circuit 100 by the microprocessor 16 to provide a desired deformation in the position of the linear actuator 12 and the connected hand frame, As shown in FIG.

The error signal generated by the error calculation logic 100 returns to the microprocessor 16 where it is compared to the pre-set reference level. If the error signal exceeds the pre-set reference level, it indicates that the speed or acceleration of the actuator 12 does not reach the desired value and the current applied to the actuator coil reaches a level that is unacceptable. This may be the result of a frictional force in the machine that has failed or increased. When this phenomenon occurs, the microprocessor 16 supplies current to the coil drive circuits 108 and 110 in a limited manner to prevent the applied current from reaching an unacceptable high level.

This can also be achieved by monitoring the deviation between the set reference value and the position difference signal in the logic circuit 120. If the deviation increases beyond the pre-selected level, the actuator will again fail to reach the required velocity or acceleration as a result of the malfunction and the coil current will reach a level that is unacceptable.

The time-domain velocity graph shown in Fig. 3 compares an embodiment of the present invention (curve B) with an ideal conventional drive system (curve A in Fig. 1).

As can be seen, the preferred embodiment of the acceleration and deceleration time of the drive system of the present invention _a t`, t` _d without significantly adverse effects to the short and the reciprocating rate of the frame time t`c held over the standing time than the conventional system dramatically And the shed is opened to turn the weft. The rate exceeding a thousand picks per minute is achieved compared to the conventional one with a peak at about 600 peaks per minute.

The use of each of the actuators 12, 14 can have considerable force expenditure. However, a preferred drive system is one in which the kinetic energy of the < RTI ID = 0.0 > mv ² ) can be used to avoid this.

Assuming that the actuator 12 drives a handle frame from the lowest shed position, which is upward according to curve B in Figure 3, the actuator controller 18 monitors the velocity of the actuator in the manner described above, With the desired speed v ₁ set by the change in the desired position signal from the target position signal. Since the initial speed of the actuator 12 and the held frame is less than v ₁ the controller 18 applies a power to the actuator so as to increase the actuator speed. However, the acceleration of the actuator 12 is held constant (as determined by the slope 30 of curve B) in accordance with the reference set by the microprocessor 16 and compared with the deviation signal in the logic circuit 120. The reference value is increased according to the microprocessor 16 at a pre-selected ratio from the first maximum preset value to the second maximum preset value. Enabling the actuator 12 to be powered at a controlled rate that ensures normal acceleration of the actuator 12 at a pre-selected rate.

Before or immediately before the time t ' _a, the reference value reaches a second preset value set by the microprocessor 16 as the maximum value, and is fixed at that value. This is effective to prevent further acceleration of the actuator (12) for continuously at a desired speed v _1.

Reference value is maintained at its maximum value in t` _c above to maintain the speed of the actuator (12) and held in the frame ₁ v.

T` time _d before or microprocessor 16 immediately before the start to reduce the reference value from its maximum value toward again to the first preset value. This reduces the power of the actuator at a relatively constant rate and thus decelerates the actuator 12 in a controlled manner.

During the deceleration period of the actuator 12, the actuator 12 functions to shut off the electromagnet on the handle frame, such that the handle frame is pointing at its uppermost shed position, producing power. The excess power is generated by the actuator supplied by the controller 18 to the storage power capacitance 20.

Once the heald frame reaches its best shade position, the actuator 12 is accelerated in the reverse direction and the cycle is repeated in the same manner as described above. Again, when the actuator is decelerated toward the lowest shade position of the heald frame, electrical energy is generated by the motor and is stored again in the power capacitance 20.

The actuator controller 18 monitors the power required in each actuator and supplies power from the power storage means 20 when the threshold rises.

The level of the power capacitance 20 is monitored by the monitor 22 in a manner that eventually switches the main power from the main source via the power controller 24 to the capacitance when the power capacitance level drops below a certain level do.

During operation of the textile machine, the power returning to the system by each actuator will be below the limit initially monitored by the monitor 22. This is achieved by the system as a device that, if the power level is below the limit, nothing returns to the power capacitance and, if possible, the operating speed is reached as quickly as possible. Once the power level is returned to the system by the actuators 12,14, it rises above the limit of the monitor 22 to allow the power capacitance to flow. And is transmitted from the power capacitance to the actuator by the actuator controller when power is required by one of the actuators.

The use of the apparatus described above is regenerated and returned to the main source to reduce the total energy cost in any unbalanced energy state, significantly reducing the required energy derived from the main source.

While the above description relates to the application of the invention to a textile machine, the invention described above is equally applicable to the yarn holder of the control and / or knitting machine of the needle.

The invention is also directed to a method of making a knitted fabric, which is guided in a vibrational fashion, such as a flatbed and circular knitting machine, a needle plate of a sewing device, a tuft needle, a yarn winding device and a composite motion of various stokes and frequencies, It can be applied to any other type of device with inertial mass.

Some inertial mass, such as the needle frame of a textile machine or the needle of a knitting machine, can be driven separately from one another at various stokes and frequencies.

With reference to Fig. 7, Fig. 3 shows the motion pattern of the heddle frame of the textile machine, but the motion is not ideal in Fig. In other words, the handheld frame is accelerated from its lowest position to its center shed position at full speed and vice versa, decelerating toward its recall shed position.

Figure 8 shows a simpler form of operation of the hand frame in sinusoidal form. Each of the above modes of operation can be applied to any inertial mass oscillating between the two positions.

Claims (16)

A drive system (10) for driving an inertial mass (40) over a drive path between a first and a second shortest position, Electric drive motors (12, 14); Coupling means (30) connecting said drive motor (12, 14) to said mass (40) for driving said mass; Storage means (20) for storing electric power; And Control means (16, 18) for applying power to the drive motor (12, 14) which accelerates the mass (40) from one of the first and second shortest positions over a first portion of its drive path, , Wherein the control means (16,18) connects the drive motors (12,14) to the storage means (20) so that the drive motors (12,14) are located at the first and second shortest positions Characterized in that the drive motor (12, 14) functions to charge the storage means (20) when the electromagnet is cut off during the deceleration of the mass beyond the second position of its drive path towards the other. 2. The apparatus according to claim 1, further comprising monitoring means (22) for monitoring an energy level stored in said storage means (20), wherein said control means And to supply power from said storage means (20) to said drive motor (12, 14) during acceleration of said mass (40) beyond said first portion of said drive path when said mass (40) is exceeded. 3. The apparatus according to claim 1 or 2, further comprising monitoring means (28) for monitoring the current portion of the mass and continuously providing a monitored current position signal accordingly, wherein the control means Further comprising control means (18) for comparing said desired and monitored positions and thereby controlling the power supplied to said drive motors (12, 14). 4. The drive system according to claim 3, wherein the desired position signal is varied in a continuous manner. 5. The system according to claim 3 or 4, wherein the control means (18) comprises: first storage means (120) for storing the previously monitored current position signal; Further comprising comparison means (116) for comparing the current position signal with the previously monitored current position signal and generating a position error signal accordingly, wherein said control means (18) (12, 14). ≪ / RTI > 6. The drive system according to claim 5, wherein said control means (18) further comprises second storage means (118) for storing said current position signal, respectively. 7. A drive system according to claim 6, characterized in that the second storage means (118) is operative to update the stored current position in connection with the first comparison means (116) and in response to receive the position error signal . 8. Device according to any one of claims 4 to 7, characterized in that the control means (18) comprises means (120) for comparing the deviation between the pre-monitored and stored reference value and the current position signal and generating a second signal accordingly, , Wherein the control means (18) is operative to control the power supplied to the drive motors (12, 14) in accordance with the second error signal. 9. The drive system according to claim 8, wherein the second error signal is a function of the position error signal. 10. A drive system according to claim 8 or 9, characterized in that said reference value is generated by said processor means (16). 11. The drive system according to claim 8, 9 or 10, wherein the reference value is variable. 12. A device according to any one of the claims 3 to 11, characterized in that the control means (18) further comprise means (124) for controlling the direction of drive of the mass (40) in accordance with the monitored current position signal Wherein the direction control means operates in opposition to the driving direction of the mass in response to the monitored current position signal indicating that the mass (40) reaches one of the shortest positions. 13. A system according to any one of the claims 3 to 12, characterized in that the control means (18) comprises second comparing means (12) for comparing the desired position signal with the monitored current position and producing a third position error occurrence signal accordingly 100), wherein the control means (18) is operative to control the power supplied to the drive motors (12, 14) in accordance with the third position error signal. 14. A method according to any one of claims 3 to 13, wherein the control means (18) is configured to control the power transmitted between the drive motors (12, 14) and the storage means (20) Further comprising means (102) for driving the motor. 15. Drive system according to any of the claims 1 to 14, characterized in that the mass (40) is a heald or a handle frame of a textile machine. 16. A drive system according to any one of claims 1 to 15, characterized in that the mass (40) is a needle of a textile machine or the like.