Structure and working principle of water jet loom (2)

(1) Nozzle
The nozzle specifications include the diameter of the spray needle and the nozzle (inner hole). At present, the commonly used specifications are 1.4, 1.6, 1.8, 2.0 for spray needles, and 2.1, 2.4, 2.5, 2.6, and 2.8 for nozzles. The variety of the fabric and the diameter of the needle and nozzle (mm) through wire, processed wire 2.5, 2.6, 1.8, strong twisted wire 2.6, 1.6, 1.84, 2.0, etc. vary with the speed, width, water pump plunger and spring. Changes.
(1) Yarn press
The function of the yarn presser is to control the weft thread to start entering the shed and end the flight to clamp the weft thread. It is an essential part of the weft insertion mechanism. Divided into mechanical pressing and electronic pressing, the opening and closing are controlled by the electronic control program, which is used for double nozzles and multi-nozzles. Mechanical pressing is mainly used for single nozzles.
When the loom is running, the rotation of the yarn presser cam causes the cam link to swing, which drives the yarn presser link to swing, so that the yarn presser shaft moves up and down, and controls the weft yarn to enter the shed and end the flight.
(1) Setting of weft insertion time
(1) Setting of weft insertion time, the jetting start time is set at the reed swings backwards, and when the reed face (front) just passes the center of the nozzle, water is sprayed. Because the machine is equipped with different reed strokes, the jetting starts The time setting is different, such as: single jet (75 stroke) is 85°, double jet (95 stroke) is 90°.
(2) At the end of the flight, it should be set before the reed swings forward to the centerline of the nozzle.
(3) The injection start time is set by adjusting the position of the water pump cam.
(4) The start time of the weft flight during the weft insertion and the end time of the weft flight at the end of the weft insertion can be set by adjusting the position of the yarn presser cam.
(5) In order to ensure smooth weft insertion, it is necessary to straighten the short wire protruding from the tip of the nozzle and set a leading angle. Therefore, the time to open the yarn presser is delayed from the injection start time, and this angle is the advance angle. According to the different weft yarns, it is usually set as: cotton and polyester 10°, strong twisted yarn 5°-10°, and polyester processed yarn 15°-20°.
(1) Double-pump weft insertion mechanism
With the development of weaving technology, a single water pump can no longer meet the requirements of multiple types of fabrics, and double water pumps have emerged at the historic moment. The double water pump can realize the stable weft insertion of two kinds of weft yarns with very different linear densities and characteristics. Even when the same kind of weft yarns are mixed, each nozzle is set with the best weft picking conditions, so high-speed and stable weft picking effects can be exerted. Double water pumps achieve four jets, that is, one pump controls one weft yarn and the other pump controls two weft yarns. The situation that one pump controls two wefts is the same as the situation of single pump and double jet, so I won't repeat it here. Here is a brief introduction to the working principle of the double pump. Two pump cams are installed on the drive shaft. When the high point of the pump cam is in contact with the connecting rod arm of the water pump, the water pump sucks water from the water tank, compressed by the water pump spring, and enters the reversing valve. The water of pump 1 or pump 2 is controlled electrically. The water sprayed from the nozzle, and the water sprayed by the other pump is returned to the water tank through the reversing valve. Regardless of whether it is a single pump or a double pump, the principle of weft insertion is the same. The difference is that the water of the single pump is sprayed through the nozzle every time, while the water of one of the pumps is sprayed through the nozzle when the double pump is working. , And the water from the other pump is discharged through the reversing valve, and the sequence can be pre-set by the electronic control system Standard loom process time Different loom models and fabric varieties, the standard process time of the loom will vary different.