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Section 7. Technical sciences
Djuraev Anvar Djuraevich, technical sciences associate professor of the Department"Theoretical and applied mechanics", Tashkent Institute of Textile and Light Industry, Republic of Uzbekistan E-mail: djuraevanvar1948@mail.ru Madrahimov Shavkat Halimovich, teacher of the Department"Theoretical and applied mechanics"
E-mail: shohruz200904@mail.ru
Urinova Sohiba Isroiljonovna, teacher of the Department "Theoretical and applied mechanics"
Ways of reducing superfluous communications in battant mechanism of weaving looms
Abstract: In this article, new scheme of cam and lever battant mechanism with compound hinges, including elastic elements ofweaving looms are investigated. The technique of liquidation and decrease in superfluous communications in kinematic steams of battant mechanism of the weaving looms are presented.
Keywords: weaving loom, beater, cam, lever, elastic element, inertiaforces, reactionforces, superfluous communications, mobility degree, and kinematic pair.
nisms can be divided by type into two main groups — crank and cam drive. Shuttle weaving looms contain most widespread mechanisms of the first group. Cam drive battant mechanism widespread in shuttle-less weaving looms.
Battant mechanisms must satisfy the following technological and technical requirements:
- swing reed must be the least to avoid strong grinding teeth reed warp yarns; weft thread to the edge of the fabric to be nailed smooth pressure and not blow;
- the mass of the batten should be small and sufficient to meet all technological and mechanical operations of the mechanism;
- bounded speed driving modes due to large inertial forces and reactions in kinematic pairs due to redundant links in the mechanism; rapid failure of bearings, and low resource mechanism.
To ensure the necessary technological requirements and increase the effect of the work mechanism Batant recommended method to reduce redundant links in the mechanism by the use of elastic elements in the kinematic pairs [2].
Fig. 1 is a diagram of the batant mechanism, which is used on looms. Cams 1 and 2 are rotating about shaft O. The cam 1 contacts with the roller 6 and the cam 2 contacts with the roller 3, which are installed on the crank 4, the latter is located on the shaft 5. On blades 7 mounted beam 8 and reed blade 9. The blades are significantly shorter than blades of conventional shuttle machines. On the beams of the battant from the edge of the fabric fixed comb, made from steel plates 10. They are guide when moving the thread-plotters through the throat (on machines ATPR, plate 10 is not mounted on pneumatic looms, confuse attached to the beam 8). Battant mechanism is considerably facilitated, as it has no shuttle boxes and the mechanism warning a separation of the basic threads at thread plotter (last one moves in a pharynx on directing combs). For the given mechanism, we define quantity of superfluous communications according to [3].
The main technological function of battant mechanism of the shuttle-weaving loom is nailing the weft yarn to the edge of the fabric. Besides, the battant mechanism carries out a number of additional functions: it provides the movement of the shuttle on the beam, sets in motion the mechanisms of commodity and main regulators, automatic change of bobbins, unloading valves and others. On battant mechanism of shuttle-weaving looms mount multishuttle devices, safety devices from a start of a shuttle and control mechanisms wrap threads. Battant mechanism of these machines consists of the fighting mechanism, picking stick, which performs translational motion together with battant [1].
Fig.1. Battant mechanism of the STB weaving loom
On battant mechanism of the shuttle-less looms are installed guide combs for moving the thread-plotter or special channel-con-fuser for pneumatic or hydraulic machines [1]. The battant mecha-
Ways of reducing superfluous communications in battant mechanism of weaving looms
q = W-6 n + 5 P5 + 4 P4 + 3 P3 + 2 P2 + P^ (l)
where, W — degree of mobility of the mechanism, P5 , P4 , P3 , P2 , P1 — quantity of kinematic pairs of fifth, fourth, third, second and first classes; n — quantity of mobile links. In the considered mechanism Fig. 1, it agree, W = 5, n = 4, P5 = 4, P4 = 2 and accordingly the quantity of superfluous communications will be q = 3.
It is known that, superfluous communications appear because axes are not parallel kinematic pairs. Thus, there are great strengths of reactions in kinematic steams and their fast failure. To eliminate of superfluous communications, usually reduce a class of corresponding kinematic pairs [3]. We have to eliminate redundant links recommended to perform hinge components include elastic elements. In addition, each coordinate or direction of elastic deformation elements respectively eliminates a redundant link in the mechanism.
Fig. 2 shows battant mechanism which comprises a housing 1, a cam 2, counter-cam 3 mounted to the main shaft 4. Compound rollers 5 and 6 are hinged to the lever 7 and trehplechem contact with profiles (surfaces) of the cams 2 and 3. The rollers 5 and Compound 6 include hinges 9 and 12 are impaled on the resilient rubber bushings 13 and 14. The thickness of the rubber sleeve 13 is twice larger than the thickness of the elastic rubber sleeve 14. The lever 7 mounted pivotally on a shaft 8. The third lever arm 7 connected rigidly to the timbers 10 and 11.
Shoulder reed 7 of three-humeral arm further connected to the shaft 8 with a torsion spring 15. The elastic rubber bushings 13 and 14 are made of oil-resistant rubber stamps.
Following formula is recommended for definition of superfluous communications of the proposed mechanism:
q = W- 6 n + 5 P + 4 P + 3 P + 2 P2 + Pi - К, (2)
where, K-quantity of elastic elements in kinematic pairs of the mechanism or coordinate of their deformation.
For recommended battant mechanism K = 3, then q = 0, superfluous communications are eliminated. For the following кулачкового the mechanism it agree rice 3, superfluous communication will be a rhubarb to unit, as in mechanism K = 2.
For the next cam mechanism according to Fig. 3, excessive communication will be the rhubarb unit, as in the mechanism of K = 2.
Fig. 4 shows a diagram of the four bar crank-hinge mechanism used as a battant mechanism of weaving looms.
The mechanism consists of a crank 1, rod 2, the rocker 3, and carrying reed 4 of rider 5. According to the method described in [3], for this mechanism would be:
W = 3 n - 2 P - P = 3 • 3 - 2 • 4 = 1;
5 4 '
Q= W - 6n + 5 P - 4 P = 1 - 18 + 20 = 3.
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To eliminate redundant links in the lever battant mechanism, the kinematic pairs made components; including elastic elements (see Figure 5).
Battant mechanism of the weaving machine consists of a frame 1, crank 2, connecting rod 3 and the rocker 4, interconnected by hinges 7, 8, 14, 15. The rocker arm 4 carries a reed 5 and rider 6. Hinge 7 between the two crank and connecting rod 3 is made integral, comprising an axle 12 rigidly connected to the rod 3, on which the elastic sleeve 13 is pushed over the concave curved shape forming. In the elastic sleeve 13 is mounted with a hub 11 corresponding to the convex curved shape forming the inner surface. The sleeve 11 is rigidly connected to the crank 2. Hinge 8 also made compound includes an axle 9, is rigidly connected to the axis of the rocker 4. At axle 9 planted elastic sleeve 10 with an elliptical cross-section, on which a sleeve 11 is rigidly connected to the rod 3.
Fig. 2. Battant mechanism of a weaving loom with compound cam rollers
Fig. 3. Battant mechanism of a weaving loom with elastic elements
Fig. 4. Four bar crank-hinge mechanism
Fig. 5. Lever battant mechanism of the loom with composite joints Table 1. - Shows the main indicators discussed in battant mechanism of weaving looms
№ n P5 P4 q W K
1 Cam drive battant mechanisms (fig. 1) 4 4 2 3 5 0
2 Battant mechanism of a weaving loom with compound rollers and cam with elastic elements (fig. 2) 4 4 2 0 5 3
3 Battant mechanism of a weaving loom with elastic elements (fig. 3) 4 4 2 1 5 2
4 The scheme four bar slider mechanism (Fig. 4) 3 4 0 3 1 0
5 Lever battant mechanism of a weaving loom with compound hinges (Fig. 5) 3 4 0 0 1 3
Taking into account that the elastic elements in the hinge beater provide deformation along three dimensions, by their marks in the form of an ellipse and a concave curved way, then K = 3. At the same time, respectively, will be eliminated redundant links in the kinematic pairs of mechanism.
Conclusions
New schemes of battant mechanism with elastic elements of weaving looms are recommended. The technique of elimination of superfluous communications in kinematic pairs of battant mechanism is developed.
References:
1. Baranova A. A. Battant, additional safety mechanisms and weaving machines: Methodological guidelines for laboratory work on the course for students majoring MTTM 1-50 01 01 - "Technology ofyarn, fabrics, knitted fabrics and nonwovens" - Vitebsk, 2007. - S. 1-10.
2. Dzhuraev A. et al. Structural, kinematic and dynamic analysis of the lever-shaft couplings with elastic elements propeller mechanisms. Monograph. Ed. - "Fergana", 2013. - P. 116.
3. Dzhuraev A. and others. The theory of mechanisms and machines. Ed. "G. Gulyamov". - Tashkent, P. 592.
