The loom is composed of five major mechanisms: shedding, weft insertion, weft beating, let-off, and take-up, commonly known as the five major movements.
The adjustment methods and requirements of each institution are as follows:
图1：Air jet loom
1. Coiling mechanism
The winding movement of this machine adopts the turbine type intermittent winding mechanism. Coiler worm toothing requires flexibility and centering. For the adjustment of the coiling stroke, there is a sliding rotor on the right sley, the upward stroke is large, that is, the number of supporting teeth is large, and the downward stroke is small, and the number of supporting teeth is also small.
The weft density is calculated as follows:
Inch system: number of ratchet teeth = weft density * number of teeth per weft / 3
Metric system: number of ratchet teeth = weft density * number of teeth per weft / 1.175
2. Delivery mechanism
1. The warp let-off mechanism is the outer vertical warp let-off, and this set of devices is ideal. Adjust the spring force according to the size of the warp beam. Automatically adjust the let-off amount by warp tension, and maintain a certain warp tension.
2. The teeth of the disc and the let-off gear are in good condition. Tension adjustment:
A. The screw rods on the three springs rotate clockwise, the tension of the cloth surface will increase, otherwise the tension will decrease.
B. The cloth surface will become tighter when the tension weight goes forward, and it will be transferred backward.
C. Two 12cm screws tighten the cloth surface tension will increase, otherwise the tension will decrease.
D. In the weaving process, the let-off compensation required by different weft densities is different. Generally, a weft density of 32-80 threads/cm uses a single-head worm gear, and a weft density of 16-32 threads/cm uses a double-head worm gear. ~16 heels/cm uses three-head worm gear for let-off and double-head worm gear for take-up.
3. Transmission and braking mechanism
1. Electromagnetic clutch and electromagnetic brake are the key transmission parts of the loom, the gap is 0.2mm~0.5mm, and the two friction surfaces are even around.
2. There should be no oil. If it slips, wipe off the oil with a cloth or wash it with diesel oil to avoid bad brake position.
3. The small belt pulley should always check whether the key shaft is off, so as to avoid the shaft hole of the small belt pulley becoming larger, the motor shaft and keyway worn, and the transmission wheel not to lose oil, otherwise the bearing is easy to wear, and the gap is too large, which will cause abnormal noise.
4. The drive belt should not be too tight or too loose. Check the belt for skew.
4. Opening mechanism
The 743 loom adopts the pedal opening, and the 747 loom adopts the dobby to complete, and the spring steel heald is used below. The sprocket is connected to the dobby sprocket through the chain transmission. Its motion is caused by the crankshaft, and the opening time is 285°~310°, generally around 290°. The end face of the first heald frame is 310mm~315mm from the inner end face of the top beam (when the crankshaft is at 180°, it is about 265mm~270mm from Dalong to the end face of the heald frame). The heald frames cannot fight each other. The heald lifting arm to the pulley and the steel heald box should basically be in a straight line. It is better to start the first and second pieces of the heald lifting arm on the dobby with the third or third and a half gears. The slider on the heald lifting arm has a small opening upwards and The bottom is that the opening is large, and the movement of the heald frame should be stable.
5. Weft insertion mechanism
1. The weft insertion mechanism is composed of two sets of connecting rod mechanisms. The sector gear can swing around 0 o’clock. The support leg and the sley foot are fixed as one and swing synchronously. Therefore, when the crankshaft moves back and forth to drive the sley foot to swing , 0 o’clock means swinging around the center of the rocking shaft at 0 o’clock to make the sector gear produce a swing motion relative to the sley foot, which constitutes the motion in the weft insertion motion.
2. The rotation of the crankshaft drives the central shaft to rotate. One end of the connecting rod is connected to the central shaft. It has an eccentric “e” with the center of rotation of the central shaft to generate a small crank rotation. The other end of the connecting rod is connected to the sector gear, thereby making the sector gear An additional movement occurs relative to the sley foot.
3. The above two movements (i.e. the main movement and the additional movement) are superimposed to become a compound movement of the sector gear relative to the sley foot. The cylindrical tooth shape and the conical tooth shape are fixed on the same axis, and the sword wheel is installed on the shaft of the bevel gear. In this way, the swing of the sector gear is transferred to the reciprocating rotation of the transfer sword wheel through the meshing between the gears, thereby driving the transfer rapier belt and the sword head to complete the weft insertion movement.
According to the reed width to be woven, adjust the connection point A position of the connecting rod and the sector gear to ensure that the rapier head can be correctly handed over in the center of the sley, so that the bending axis of the loom is at 70° at the yarn inlet of the rapier head ~75° between.
6. Beating mechanism
The guide rail piece should be calibrated with a gauge, and it should be easy to pass without being too loose. The shuttle box and the guide rail should be perpendicular to each other and must not be skewed. The sword belt should fit easily in the rail and shuttle box. Always check the looseness of the track piece and the shuttle box screw. When the width of the sword belt bakelite wears to 225mm and the thickness wears to 1.5mm, it must be replaced in time, otherwise the sword head will be worn. From an economic point of view, often It is more cost-effective to replace the bakelite chips.
7. Color selection agency
1. The height distance between the color selection rod and the cover of the shuttle box is 2~3mm. The 6 color selection rods cannot touch each other. The color selection pulley and the rocker arm should be flexible and vertical.
2. There is an eccentric shaft in the color selection box. With the help of the eccentric effect of the shaft, the toothing between the gears should be good. Drive sprocket tension should be moderate.
3. The relationship between the height of the color selection rod, the height of the temple cover and the weft feeding sword. If the color selection rod is too high and the temple cover is too high, the weft yarn will pass over the sword head, and the weft yarn will not be brought in, resulting in weft insertion errors. If the color selection rod is too low, it will collide with the cover of the shuttle box, causing the head of the color selection rod to break and the surface of the shuttle box to be worn. If the temple cover is too low, the weft yarn may go under the rapier head, and the rapier head cannot bring in the weft yarn, resulting in failure of weft insertion. At the same time, warp breakage will occur, and the warp yarn will be cut off on the cloth surface.
8. Broken warp organization
a. The machine’s warp-breaking self-stop mechanism adopts a contact-type six-column electric warp-stopping structure.
b. The electric warp stop device is fixed on the support foot of the warp stop frame of the middle beam of the loom. The six long warp stop rods are composed of copper strips and stainless steel skins. The contact surface between them is placed with a polyester film for insulation. One is from the electric control. The two lead wires of No. 15 and No. 16 cables of the box are connected respectively on the two screws of the support correspondingly connected with it. When the warp yarn is broken, the warp drop will fall due to its own weight. Under the action of the inclined surface at the upper end of the long slot of the warp, the warp will touch the copper bar and the stainless steel skin at the same time, which will cause a short circuit and automatically stop the machine.
Post time: May-16-2023
