SU1659549A1 - Thread-tensioning device of high-speed warp-knitting machine - Google Patents

Abstract

The invention relates to a knit machine industry, namely, to nitenate devices of high-speed bases — hall machines, and allows to increase reliability in operation. The filler device contains a rock made of a low-density material and in the form of a beam shaped profile core-shaped, the support surface of which is in contact with an elastic element made in the form of a chamber of thin elastic material filled with compressed air and enclosed in a casing, 2 h. P. f-ly, 3 ill., 3 tab.

Description

J

The invention relates to the field of knitting machine building, namely, to ni- tary devices of high-speed foundations of aerial machines.

The purpose of the invention is to increase reliability in operation.

Figure 1 shows the scheme of the thread-bearing device to the high-speed base in the filling machine, cross-section; figure 2 - the same general view; Fig. 3 is a tension rock diagram, cross section with designation dimensions.

The thread-tight device for the high-speed warping machine contains a tension rock 1, made in the form of a bent shaped profile profile core, the supporting surface 2 of which, interacting directly with the elastic element 3, is a part of the cylindrical surface whose geometrical axis 4 coincides with the axis of the cylindrical surface 5, interacting directly with the threads 6 of the base, and the elastic element 3, made in the form of an elliptical chamber 7 with a thin elastic, for example rubber, about 8. The hull of the chamber 7 enclosed in a casing 9 with a longitudinal slit 10 whose width is equal to the width of the support surface 1 two rock and filled with compressed air. A thread-separating ridge 11 and a thread guide roller 12 are installed in front of the tension rock, providing the necessary wrap angle with the rock strands 6 of the warp. The height h of the cylindrical surface 2 is equal to or slightly greater than the maximum oscillation amplitude of the rock during operation of the machine.

Let us determine the height h of the segment for a given radius R of the sector OADB and the central angle a (Fig. 3).

h R -OS R-RCosy R (l -cos y) ())

About SP

you ate

-N

H)

If the value of h is given, then you can determine the radius R of the sector at different angles and by the formula

h (2)

R

1 - Cos |

The calculated values of the radius R are given in table 1.

As can be seen from Table 1, with an increase in the height of the segment h and with a decrease in the central angle a, the radius R of the sector sharply increases, which leads to an increase in the size of sy; ala. The total height is rock, where r is the radius of a cylindrical surface, con- tacting with the warp threads, which can be taken to be equal to mm.

The next important parameter of the rock is the area of the ADB segment, from which magnitude the variations in the volume of air in the chamber of the elastic element during rock oscillations and the total volume of the chamber depend.

The area of the segment is found as the area of the AOBD sector and the AOW triangle (FIG. 3), i.e.

Seer -

7TR2 a

360 pas

12

but

2Rslri7f a

R cos tr

The above calculations confirm the possibility of obtaining a very compact nitrating device to the bases — a filling machine. 5 Take the following notation:

V is the volume of the chamber influenced by the tension rock;

P is the air pressure in the chamber; F is the minimum tension of the threads 10 of the base;

D V - reduction of the volume of the chamber at the maximum lowering of the rock by the value of h;

Д Р - increase in air pressure in the 15th chamber;

D F - increase the tension of the warp threads.

According to the equation of state of an ideal Mendeleev-Clapeyron gas

20 PV (P + AP) (V-AV) RT (6)

where M is the mass of gas;

ja is the molar mass of gas; R is a universal gas constant; 25 T - absolute gas temperature.

With constant values of M, fi, R and T

(w-sinrcosҐ)

360 but sln-y then

 R2

cos -7-ggr sina,

na

thirty

seg

 L cin n 360 h

(3)

PV (P + A PXV- A V) const. From equation (7) AVDR

(7)

(eight)

V Р + ДР The total tension of the warp threads transmitted to the rock is balanced by the force of air pressure in the chamber, i.e. 35, and DR D PS, l

But the magnitude of the radius R depends on the required height h of the segment and the central angle a, therefore, equation (3) after the stand, the value of R from equation (2) takes the form

Seer

(pas 1 q

a.2 360 2b1poch

9 )(

(1 - Cos J y {/,)

The area of the segment at various values of h and a is presented in Table 2.

The width of the rock is equal to the length of the chord AB and is determined by the accepted values of the height h of the segment, the central angle a and the radius R

(five)

W AB 2RSln |

The estimated width of the rock is given in table.3.

From the analysis of the calculated data presented in table. 1-3, it can be concluded that with an increase in the central angle, the sector radius, the width and the area of the segment are significantly reduced at constant values of the segment height.

0

PV (P + A PXV- A V) const. From equation (7) AVDR

(7)

(eight)

V Р + ДР The total tension of the warp threads transmitted to the rock is balanced by the force of air pressure in the chamber, i.e. 5, and DR D PS, l

where S is the contact area of the rock with the chamber of the elastic element.

Then equation (8) takes the form

AV - DR (l

0v F + DR (

From equation (9) it is obvious that

can be picked up

volume

V

such that the changes in D F of the tension of the base thread are minimal.

Since the rock rests along the entire length

Camera control, then the ratio v

volumes can

consider as the ratio of the cross sections of the working surface of the rock (rock segment) and the chamber of the elastic element (ellipse), i.e. 5seg / 5ell or taking into account equations (4) and (9)

l FS R (GCSG 2 g), a

 SaEL

Sann

F + DR SannPYa

where a, b are the semiaxes of the ellipse.

As can be seen from table 2, the parameters of the rock can be chosen such that the area

the segment will be minimal and very small compared to the cross-sectional area of the camera (ellipse).

For example, when h b mm and a 80 ° we obtain the following parameters of the rock:, 6 mm; , 9 mm: mm2 (see tab.1-3). If you take a camera with an ellipse cross section with semiaxes mm, mm, then

, 14-40 70 8792 mm2, then according to equation (10)

p + dr 134: 8792 0.015

and AF 0.015, i.e. Changes in the tension of the warp threads are only 1.5%.

To make the device more compact and reduce the calculated volume of the chamber, the chamber 7 and the housing 9 in cross section have the shape of an ellipse that extends in the direction of the rock.

To fix the tension rock with respect to the elastic element, the rock is fixed on the elastic element along the line 13 of their touch, for example, vulcanized, and inside it contains a stretched thin string 14 fixed at points 15 and 16 to the frame of the machine. The chamber contains a duct 17 and a pressure gauge 18.

The threading device operates as follows.

The warp threads 6 pass between the teeth of the thread separator ridge 11, under the guide roller 12, over the rock 1 along its cylindrical surface 5 and are directed to the loop-forming organs of the machine.

With an increase in the tension of the threads of the base 6, the rock 1 descends and its pressure on the chamber 7 increases, the volume of which decreases, and the air pressure in it increases. This compensates for the lack of length of the yarn in the looping zone and reduces the tension of the yarn to the desired value. With a decrease in the tension of the warp threads as a result of an excess length of the threads in the loop formation zone, rock 1 rises under the action of a pressure difference on the rock of the elastic element and warp threads. As the rock moves upward, an excess of the length of the warp threads in the loop formation zone is compensated for and the tension of the strands increases to the desired value. In this case, changes in the tension of the warp threads will be minimal due to the high compressibility and elasticity of the air in the chamber. The air pressure in the chamber is monitored by a pressure gauge 18.

The working surfaces of the rock in the areas of its interaction with the warp threads (uchatok 5) and the elastic element (section 2) are cylindrical with a common axial line 4 of their centers, thereby providing radial directions of forces

5 pressure on the rock from the side of the warp and compressed air in the chamber, the resultant of which is directed in the same plane, and the steady position of the rock relative to the chamber. For the same purpose, the cable is fixed on the chamber along the line 13 of their tangency, and inside it contains a taut thin string 14 fixed at points 15 and 16 to the frame of the machine.

Claims (3)

5 The tension device to the high-speed warping base allows the compensation of excess and deficiencies in the length of the warp threads in the loop formation zone, due to the peculiarities of the loop formation process on the main die machines and to maintain the tension of the warp loop during the loop formation, which will increase uniformity of the heel structure and stability of knitwear structure parameters at high speeds of the machine operation, as well as when the machine is stopped and started; eliminates the conditions for the formation of a defect in the base of the base fabric (transverse banding) that occurs when the machine is stopped and started; Claim 1. The thread-tension device of the high-speed base of the die machine containing a tension rock made of a material of low density, the cylindrical surface of which contacts the base threads, and an elastic element in contact with the rock and made in the form 0 chambers of thin elastic material filled with compressed air and encased in a casing, characterized in that, in order to increase reliability in operation, the tension rock is made in the form of a beam 5 of the shaped profile of a core-shaped form, the supporting surface of which is in contact with the elastic element along its entire length and is a cylindrical surface, the geometrical axis 0 which coincides with the axis of the cylindrical surface in contact with the warp threads. 2. Pop.1 device, characterized by the fact that the elastic element is made 5 elliptical in cross section. 3. The device according to PP 1 and 2, that is, with the fact that it was attached to the elastic element along the line of their contact. Table 1 table 2 Table 3 sixteen 2