opening mechanism

Opening mechanism

The shedding mechanisms of projectile looms mainly include: positive cam shedding mechanism, positive dobby machine, large jacquard machine (double-stroke, full shedding) and high-speed edge jacquard machine, etc.
1. Positive pedal shedding mechanism
The positive cam shedding mechanism is a simple and reliable shedding mechanism that can weave 4, 5, 6, 7 and 8 weft circulating fabrics, and can hold up to 10 to 14 pieces of fabric. The frame uses a conjugate cam to actively control the healing of the heald frame. Through the design of the cam curve, the healing law of the heald frame is optimized, making the healing of the heald frame smooth and harmonious. Other cam opening mechanisms have simple shed adjustment and are equipped with automatic shed leveling devices.

The structure of the positive cam opening mechanism is shown in Figure 4-10. There are 10 groups of opening cams 13 on the camshaft O1, and each two mutually conjugated opening cams form a group. The two rotors 12 on the swing arm 11 are respectively in contact with the surfaces of the two conjugated opening cams. When the opening cam 13 rotates, the rotor 12 causes the swing arm 11 to swing around the axis O2. There is a clamping block 14 at the upper end of the swing arm, which is fastened to the upper end of the swing arm 11 by means of screws 15. One end of the connecting rod 10 and the upper end of the swing rod 9 are hingedly connected; the other end of the connecting rod 10 extends into the hole at one end of the connecting block 16, and the two are connected by screws 17. The other end of the connecting block 16 is clamped The blocks 14 are hingedly connected. The lower end of the swing rod 9 is connected to one end of the horizontal rod 7 through the long connecting rod 8, and the horizontal rod 7 is connected to the two swing angle arms 5 through two pins 5a. When the swing arm 11 swings, the swing rod 9 also swings through the clamping block 14, the connecting block 16, and the connecting rod 10, and through the long connecting rod 8 and the horizontal rod 7, the swing angle arm 5 is centered on the axis 6 Do swinging for leisure. The other arm of the swing angle arm is hingedly connected to the connecting rod 4 through the pin 5b, and the connecting rod 4 is hingedly connected to the lifting rod 3 through the pin 3b. The upper end of the lifting rod 3 has a hook head 3a, which can extend into the hole of the heald frame 2 and hook with the square block 2a fixed in the heald frame 2. When the swing angle arm 5 swings, the heald frame 2 is lifted and lowered in the guide groove of the guide frame 1 through the connecting rod 4 and the lifting rod 3.
2. Automatic leveling device
The automatic leveling device is suitable for the cam opening mechanism. It is composed of a driving motor and a reduction gearbox. When the warp or weft yarns are broken, the automatic leveling heald device can adjust the heald frames to the same height. Its operation is completed using the plug-in (FH1) of the electronic and electrical control box. As shown in Figure 4-11.

Different positions of switch handle 2 (KFW) and switch handle 3 (SFW) on the plug-in can achieve different operating states: switch handle 2 (KFW) and switch handle 3 (SFW) are both In the “OFF” position, the automatic leveling device does not work. When the switch handle 2 (SFW) is in the “ON” position, after the warp yarn is broken, the automatic flat heald device will automatically lift the shed. When the switch handle 3 (KFW) is in the “ON” position, after the weft yarn is broken, the automatic leveling device will automatically lift the shed. The working and resetting process of the automatic leveling and heald device is shown in Figure 4-12.

When the loom is operating normally, the contact of the positioning switch 9 is located in the notch 8 of the connecting disc 7, and the contact 12a of the positioning switch 12 is located in the notch 11 of the connecting disc 10. At this time, the electric motor 6 has no power supply and the automatic leveling device does not work.
When the loom is stopped, press the button 5, the motor 6 starts and rotates 180°. At this time, the contact of the positioning switch 9 is located in the gap 8a of the connecting disc 7, and the contact 12a of the positioning switch 12 is located in the connecting plate. On the surface of the disc 10, due to the action of the positioning switch 12, the loom cannot be started. At this time, the heald frame is in the flat heald position. Press button 5 again, the motor 6 starts and rotates 180° again. At this time, the two positioning switches 9 and 12 return to their original positions.
The P7300 projectile loom automatic flat heald device has two flat heald positions:
(1) Level all the heald frames at the same position to adjust the heald frame height or replace the opening cam.
(2) For automatic weft finding, the heald rods are leveled, but the heald frames are only flat and not lifted. In this way, using the automatic weft finding device, the last weft yarn to be woven can be woven without moving the heald frames. The tension remains the same.
3. Automatic weft-breaking searching device
The automatic weft-breaking searching device of the projectile loom is shown in Figure 4-13. In order to find the broken weft, the handle 1 can be moved from position I to position III, and then returned to position II. At this time, the automatic weft breaking device will perform the following actions:

(1) When handle 1 is in position I, switch cam 2 on handle 1 pushes limit switch 3, and limit switch 3 engages the electromagnetic clutch of gear device 6, so that the gear device 6 is connected to the side shaft 8.
(2) In positions Ⅱ and Ⅲ, the weft-finding and breaking clutch 7 is disengaged. At this time, the side shaft 8 is disengaged from the main engine and can rotate freely.
(3) In position III, when the limit switch 3 is turned to the second position, the motor 5 starts. The electric motor 5 rotates backward through the gear device 6 . The cam is driven to rotate reversely, causing the heald frame to relax in the reverse direction while the loom does not move.
(4) After accurately rotating one weft, the weft finding and breaking clutch 7 is automatically engaged, and the electric drive mechanism of the weft finding and breaking device is disconnected through the switch cam 2 and the limit switch 3. Return handle 1 to initial position I.
Position of handle 1:
Position Ⅰ: Weft breakage clutch��7 engagement.
Position II: The weft-finding and breaking clutch 7 is disengaged. When the loom makes one pick, it engages again.
Position III: The weft-finding and breaking clutch 7 is disengaged, the handle 1 has passed the dead center, and the weft-finding and breaking clutch 7 cannot engage.
4. The shed shape of the P7300 projectile loom
The geometric shape of the front shed of the P7300 projectile loom can be adjusted into a symmetrical shed, and the shed opening angle adjustment range is from 12° to 12°. 33° (the opening angle of the 10 pedals is 18°~33°), and the beating angle of the reed is tilted 4° toward the warp edge, as shown in Figure 4-14.

Compared with the front shed of the P7150 projectile loom, the front shed is extended by 5mm and raised by 2mm. The extension of the front shed is very conducive to beating up heavy fabrics. .
The geometry of the rear shed of the P7300 projectile loom can be adjusted to a symmetrical shed. If a double back beam is adopted, the diameter of the warp beam can reach 1016mm; if a single rear beam is adopted, the rear shed will be a symmetrical and equal tension shed. The diameter of the beam can reach 1100mm.

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