JPH05263338A - Racking device of filling knitting machine and method for determining its standard position - Google Patents

Abstract

PURPOSE:To accurately locate a racking device of filling knitting machine on a racking standard position without being influenced by backlash and loss of synchronism of step motor by determining a shogging position of needle beds at fixed intervals from slits or a mark position of a linear encoder. CONSTITUTION:In racking of needle beds of filling knitting machine, a motor drive circuit 29 is controlled by a microcomputer 28, a step motor 9 is rotated by steps corresponding to the number of pulses inputted from the circuit 29 and the needle beds are laterally moved in one direction to a position for crossing slits 23 or a mark of a linear encoder 17 for indicating shogging width of the needles beds detected by pitch sensors 19 to count the number of pulses corresponding to the lateral movement. The number of pulses up to the center of the slits 23 or the mark is calculated from the counted number of pulses. The step motor 9 is driven based on the calculated number of pulses and the needle beds are located on a standard position. Standard positioning of home position is carried out by combination of an oblong window 22 and a home position sensor 18 in the same way manner.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a racking device for swinging a needle bed in a flat knitting machine and a method for positioning the needle bed at a reference position for racking.

[0002]

2. Description of the Related Art Conventionally, as a racking device for swinging (moving laterally) a needle bed by a stepping motor (pulse motor), for example, a device described in Japanese Utility Model Application Laid-Open No. 54-139746 is known. In this conventional racking device, a proximity switch is provided in the mechanism that converts the rotation of the stepping motor into a linear motion and transmits it to the needle bed, the origin of the stepping motor is detected by this, and the rotation of the stepping motor is based on this origin. A desired swing width is given to the needle bed only by electrically controlling the direction and the number of pulses for driving the direction.

[0003]

However, if the swing width is determined by the number of drive pulses of the stepping motor, the stepping motor itself has a backlash (step error of the motor) and it is different for each motor. There is a problem that the number of pulses input to the stepping motor does not correspond to the actual swing pitch number, and an accurate swing width or swing reference position cannot be obtained.

Further, since the number of pulses is controlled so that, for example, 20 pulses are input to the stepping motor for swinging for one pitch, the load of the motor suddenly increases due to some cause, and the motor step-out occurs. Occasionally, the number of pulses cannot be accurately controlled due to the vibration caused by the step out, and the swing width and the swing reference position are displaced.

SUMMARY OF THE INVENTION An object of the present invention is to always obtain an accurate swing width and swing reference position in view of such conventional problems.

[0006]

In the racking device according to the present invention, a slit or mark for indicating a swing unit is provided on a needle bed at a predetermined pitch corresponding to the needle pitch of the needle bed (for example, 1/2 pitch of the needle pitch). The linear encoder formed in 1. is provided, and the frame supporting the needle bed is provided with a pitch sensor that photoelectrically detects the presence or absence of slits or marks of the linear encoder, and the stepping motor is driven by the signal from the pitch sensor. It is designed to be controlled.

Furthermore, in order to position the needle bed at the home position, the linear encoder is provided with a horizontally long window or horizontally long mark for indicating the home position of the needle bed, and the frame is provided with the horizontally long window or horizontally long mark. A home position sensor for photoelectrically detecting the presence or absence of

In such a racking device, the positioning method of the present invention is characterized in that when the power is turned on, a pulse is input to the stepping motor to move the needle bed laterally in one direction until the pitch sensor crosses the slit or mark. Count the number of pulses required for lateral movement of the width of the slit or mark, calculate the number of pulses required from the counted number of pulses to the center of the slit or mark, and then drive the stepping motor with the calculated number of pulses. The pitch sensor positions the needle bed at a position corresponding to the center of the slit or mark.

[0009]

According to the racking device of the present invention, the swing position of the needle bed is not fixed by the number of pulses given to the stepping motor, but by a fixed interval (for example, 1/2 pitch of the needle pitch) depending on the position of the slit or mark of the linear encoder. Since it is decided absolutely, it is possible to always give an accurate swing width to the needle bed without being affected by backlash or step-out of the stepping motor.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings. First, the mechanical structure of the racking device according to the present invention will be described. In FIGS. 1 and 2, the front needle bed 1 is fixedly attached to the frame 2, while the rear needle bed 3 is a guide pipe 5 installed between the left and right side plates 4 of the frame 2 (only the left side is shown). It is mounted on the frame 2 so as to be slidable right and left along.

That is, the groove plate 6 of the rear needle bed 3 is provided on the left and right inverted L-shaped leg plates 7 (only the left side is shown) which penetrate the guide pipe 5 and slide along the guide pipe 5, as shown in FIG. Is fixed via a reinforcing plate 8 (only the left side is shown), and is movable left and right integrally with the left and right leg plates 7 and the left and right reinforcing plates 8.

Since the rear needle bed 3 itself automatically moves to the left and right, a stepping motor 9 capable of reversing the direction is attached to the side surface of the left leg plate 7, and the left and right sides of the leg plate 7 and the frame 2 are attached. A propulsion mechanism 10 with a screw as shown in FIG. 3 is provided between the side plate 4 and the side plate 4. The propulsion mechanism 10 includes left and right bearings 1 fixed to the left and right of a left leg plate 7.
The screw shaft 12 is rotatably supported between the screw shaft 12 and the screw shaft 12.
Is screwed through a nut 13 fixed to the left side plate 7 of the frame 2, and a driven gear 16 meshing with a drive gear 15 fixed to the output shaft 14 of the stepping motor 9 is fixed to the left end of the screw shaft 12. It is a thing.

Therefore, when the screw shaft 12 rotates in the normal / reverse direction by the normal / reverse rotation of the stepping motor 9, the screw shaft 12 rotates in the normal / reverse direction.
Is propelled to the left or right with respect to the nut 13,
The groove plate 6 of the rear needle bed 3 is swung to the left or right.

In order to detect the position of the groove plate 6 and its swing width, a linear encoder 17 is provided on the groove plate 6 side, and a home position sensor 18 and a pitch sensor 19 for photoelectrically detecting the linear encoder 17 are provided on the frame 2 side. It is provided. The linear encoder 17 is screwed to the lower side of the groove plate 6 together with the reinforcing plate 8. The home position sensor 18 and the pitch sensor 19 are fixed on the sensor base plate 20 so as to be separated from each other on the left and right. The sensor base plate 20 is screwed to a clamp 21 which holds the guide pipe 5 and is fixed to the guide pipe 5.

As shown in FIG. 5, the linear encoder 17 has a horizontally long window 22 for detecting the home position of the groove plate 6 of the rear needle bed 3 and a large number of slits 23 for detecting the swing pitch of the groove plate 6. And are provided. The slit 2
3 are provided at a predetermined pitch corresponding to the needle pitch on the groove plate 6, for example, at a half pitch of the needle pitch. Home position sensor 18 and pitch sensor 19
Are both light emitting parts 18a and 19a and light receiving parts 18a and 1a.
9b and a so-called transmissive photocoupler facing each other with the linear encoder 17 interposed therebetween. The home position sensor 18 detects the presence or absence of the horizontally long window 22 by transmitting and blocking light, and the pitch sensor 19 detects the presence or absence of each slit 23. Detects by transmitting and blocking light.

Light receiving portion 18 of home position sensor 18
The output from b and the light receiving portion 19b of the pitch sensor 19 is
Waveform shaping circuit 2 amplified by amplifiers 24 and 25 respectively
After being binarized in 6.27, it is processed by a microcomputer 28 including a CPU and the like. Then, the microcomputer 28 controls a motor drive circuit 29 for driving the stepping motor 9, the stepping motor 9 is controlled in its rotation direction, and is stepwise rotated according to the number of pulses input from the motor drive circuit 29. It

Next, operation control processed by the microcomputer 28 will be described. When the power is turned on, first, as an initial setting, the rear needle bed 3 is positioned so that the pitch sensor 19 faces the center of the slit 23 of the linear encoder 17. FIG. 6 is an operation explanatory view showing the operation in the order of (1) to (6).

The rear needle bed 3 is longer than the linear encoder 17, and the positional relationship of the rear needle bed 3 to the linear encoder 17 is actually the pitch sensor 19 for the slit 23 and the lateral window 22. Although it is determined by the home position sensor 18, for the sake of convenience in describing the positional relationship, the position will be simply referred to as the position of the rear needle bed 3 with respect to both the slit 23 and the lateral window 22 for convenience sake.

When the power is turned on, the rear needle bed 3 is located at the position shown in FIG.
9 present position), the stepping motor 9
Is rotated step by step every time a pulse is input, and the rear needle bed 3
Is moved to the left by X (the number of pulses to the stepping motor 9 is X) from the left edge of the slit 23 to the left as shown in FIG. By the reversal, the rear needle bed 3 is moved rightward to the place where it crosses the right edge of the slit 23 rightward by X as shown in FIG. Then, the right and left widths of the slit 23 are measured during the rightward movement, that is, the number of pulses RC required for the rightward movement from the left edge to the right edge of the slit 23 is counted.

Next, the rear needle bed 3 is moved leftward from the right side of the slit 23 to the position where it crosses the left side edge of the slit 23 leftward again by X, and at this time, from the right side edge of the slit 23. The number of pulses LC required for the leftward movement to the left edge is counted. Then, from the pulse number LC and the pulse number RC when moving to the right, the pulse number Z required for positioning the slit 23 at the center is calculated according to the following equation.

Z = (RC + LC) / 4 + α This Z is the number of pulses required to move the rear needle bed 3 from the left or right edge of one slit 23 to the center, and in the case of this example, rightward transverse movement. The average value is obtained from the pulse numbers RC and LC detected in both the leftward and rightward transverse movements. It should be noted that α is a correction value obtained by an experiment and may be 0 in some cases.

After that, the rear needle bed 3 is moved rightward from the left side of the slit 23 to the left side edge of the slit 23 as shown in FIG. 5 (5), and as shown in FIG. The slit 2 is moved to the right by the number of pulses Z described above.
It is positioned at a position facing the center of 3 (actually, the pitch sensor 19 faces).

FIGS. 7 and 8 are flow charts specifically showing the operation shown in FIG. Steps 50 to 53 are the operations (1) to (2) in FIG. 6, steps 54 to 61 are the operations (3), steps 62 to 69 are the operations (4), and steps 70 to 70 are the steps. Up to 72, the operation (5) is performed, and at step 73, the operation (6) is performed. During each of these operations, the home position sensor 18 keeps the horizontal window 2
If it deviates from 2, that is, steps 51, 55, 58,
When YES in 63, 66, and 71, the operation is stopped as an error.

FIG. 9 is a flow chart showing the operation of moving the rear needle bed 3 from the center of the slit 23 to the center of the next slit 23 by one pitch to the right or the left, and the rear needle bed 3 is arbitrarily moved. When swinging by the width, the operation shown in FIG. 9 is repeated a number of times corresponding to the swing width. The movement by one pitch is performed by moving the rear needle bed 3 to the right or left edge of the slit 23 in steps 80 and 81 in the figure, and then in step 82 by the pulse number Z, that is, the slit 23.
It is done by moving in the same direction to the center of.

FIG. 10 shows the rear needle bed 3 at the home position,
That is, it is a flowchart showing the operation of positioning at the intermediate position of the maximum swing range. After moving the rear needle bed 3 to the left edge of the horizontally long window 22 in steps 90 and 91, the moving direction is reversed to the right and the edge detection of the slit 23 is repeated in steps 92, 93 and 94, which is performed Y times. If only the number of pulses is detected, in step 95, the pulse is moved by the number Z of pulses, that is, to the center of the slit 23 located in the center in the same direction for positioning.

As described above, when the power is turned on, the positioning operation to the center of the slit shown in FIGS. 7 and 8 is always automatically performed, but thereafter, the swinging operation for each pitch shown in FIG. 9 is performed. Whether to perform the movement operation to the home position shown in FIG. 10 can be selected by a manual operation from a keyboard or the like. In that case, it is necessary to confirm that the knitted fabric does not hang on the knitting needle, especially when the latter moves to the home position.
Also, when using a memory card for automatic organization,
Movement to the home position is prohibited to avoid trouble.

In the above embodiment, the linear encoder 17 is provided with the slit 23 and the lateral window 22, and the presence or absence of these is detected by the pitch sensor 19 and the home position sensor 18 which are transmissive photocouplers by transmitting and blocking light. However, instead of the slit 23 and the horizontally long window 22, a reflective mark may be provided on the linear encoder 17, and the presence or absence thereof may be detected by the difference in the amount of reflected light.

In the above embodiment, the pitch sensor 19 is moved back and forth for one slit 23 to the right and left in order to obtain the number of pulses Z required for positioning the slit 23 at the center. It is also possible to move transversely to one side only. For example, if the number of pulses obtained by the transverse movement to the right is RC, then Z = RC / 2 + α.

[0029]

According to the racking device of the present invention, the swinging position of the needle bed is not fixed by the number of pulses applied to the stepping motor but by the position of the slit or mark of the linear encoder. ), It is possible to always give an accurate swing width to the needle bed without being affected by backlash, step-out, etc. of the stepping motor.

According to claim 2, in the linear encoder,
Since a horizontal window or a horizontal mark indicating the home position of the needle bed is provided and the presence or absence thereof is detected by the home position sensor, the needle bed can be accurately positioned at a fixed home position.

According to the method of claim 3, the racking can be positioned with high accuracy by a simple method.

[Brief description of drawings]

FIG. 1 is a side view of an example of a racking device according to the present invention.

FIG. 2 is a sectional view of the same.

FIG. 3 is a partially cutaway plan view of a mechanism for swinging and driving a rear needle bed in the above.

FIG. 4 is an exploded perspective view of the portion shown in FIG.

FIG. 5 is a conceptual diagram of a method for detecting the position of the rear needle bed.

FIG. 6 is an operation explanatory view showing the operation of positioning the rear needle bed at the slit center of the linear encoder in the order of (1) to (6).

7 is a flowchart illustrating the operation of FIG.

FIG. 8 is a flowchart following FIG.

FIG. 9 is a flowchart illustrating an operation of moving the rear needle bed by one pitch.

FIG. 10 is a flowchart illustrating an operation of positioning the rear needle bed at a home position.

[Explanation of symbols]

 2 Frame 3 Rear needle bed 9 Stepping motor 17 Linear encoder 18 Home position sensor 19 Pitch sensor 22 Horizontal window 23 Slit

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Akira Hasegawa 1350 Nishioki, Fujii, Kashiwazaki City, Niigata Prefecture Kashiwazaki Silver Seiko Co., Ltd.

Claims (3)

[Claims] 1. In a racking device of a flat knitting machine for laterally moving a needle bed with respect to a frame by rotating a stepping motor, a slit or mark indicating a swing unit corresponds to the needle pitch of the needle bed in the needle bed. A linear encoder formed at a predetermined pitch is provided, and a pitch sensor for photoelectrically detecting the presence or absence of slits or marks of the linear encoder is provided in the frame, and the stepping motor is driven by a signal from the pitch sensor. A racking device for a flat knitting machine characterized by being controlled. 2. The linear encoder is provided with a horizontal window or a horizontal mark for indicating a home position of the needle bed,
2. The racking device for a flat knitting machine according to claim 1, wherein the frame is provided with a home position sensor that photoelectrically detects the presence or absence of the horizontally long window or the horizontally long mark. 3. The racking device according to claim 1, wherein when the power is turned on, a pulse is input to the stepping motor to laterally move the needle bed in one direction until the pitch sensor crosses the slit or mark. The number of pulses required for lateral movement of the width of the slit or mark is counted by calculating the number of pulses required from the counted number of pulses to the center of the slit or mark, and then the stepping motor is calculated by the calculated number of pulses. Is driven to cause the pitch sensor to position the needle bed at a position corresponding to the center of the slit or mark, and a reference positioning method for racking a flat knitting machine.