RU29748U1 - Anchor rod - Google Patents

Description

The utility model relates to mining, and specifically to the anchoring of mine workings.

It is known 1. p. 112 that, with the help of anchors, individual layers of rocks are fastened (stitched together) into one whole, which is what the rocks are fastened to. Possible anchor designs are shown in 1. Fig. 36, where in the caption signature the anchor body itself is called the rod.

Known anchors made in the form of solid round rods 1. Fig. 36, a, b, c, d, e, e. The disadvantage of such round rods is the impossibility of their fastening in the well with concrete or polymer mixtures.

In recent years, non-smooth rods have been most widely used, in particular, made of reinforcing steel - reinforcing rods 1. Fig. 36, item 20, on the surface of which a thread is formed during rolling, capable of holding concrete or polymer mixtures between the rod and the wall of the well. Since July 1, 1999, 2 reinforcing steel of screw profile No. 20 has been used as reinforcing rods based on the certificate of conformity ROSS Ki.MSh04.V0001 3 and in accordance with Gosgortekhnadzor of Russia Resolution No. РРС 04-22 4.

The disadvantage of the reinforcing bar according to 2 is the large angle of elevation of the trapezoidal thread and the small reduced coefficient of friction between the bar and the nut, which often leads to self-twisting of the nut from the bar under the action of axial forces and the occurrence of emergency situations in this regard.

The objective of the utility model is to eliminate the noted drawbacks.

5 shows the shape and size of the thread of the used reinforcing bar of the anchor. We give it in more detail in figure 1, where are indicated:

-P is the distance between the same points of adjacent threads or a thread pitch;

-di is the internal diameter of the thread;

-d2 is the outer diameter of the thread;

-do is the average diameter of the thread;

-2СС - double angle of the thread profile;

-a is the width of the coil head;

-b - axial projection of the right side of the profile;

-c is the width of the depression;

-1 - axial projection of the left side of the profile;

and U 2-L

-n - thread height,

In the used reinforcing bars, these values have the following values: mm, mm,, mm, 6) 40 °,,, 7 mm,, 6 mm,, 7 mm.,., I.e. with a.

.., lil.ililillillii E21D

OOG 1 1 8034

Anchor rod

as a result, it can be proved that such a connection cannot provide guaranteed retention of the nut on the anchor rod when axial load is applied to the anchor.

It is known 6. p. 23, ur-e 1.1, that the angle of the thread of a threaded rod is determined by the formula:

 or T arctg- (1)

yaoyoyo

and in the used reinforcing bar, it is equal to:

The conditions for thread self-braking are determined by 6. p.

where, g is the angle of friction in the thread. It is also known 6. p. 29 that where fn is the reduced coefficient of friction, determined from the dependence

where f is the coefficient of friction of the considered friction pair,

a is the angle of the thread profile.

If we take the coefficient of friction steel on steel, 15 7. Tab 7.1, p. 155, then according to (4) with a according to (3)

Then, according to (2), it turns out that the thread elevation angle slightly differs from the friction angle, therefore, holding the nut on the rod can be achieved only by increasing, in some way, the friction coefficient in the friction pair.

The objective of this utility model is to eliminate the noted serious shortcomings of the reinforcing steel used and widely used in mining.

The dryness of the utility model consists in the fact that for an anchor rod made of reinforcing steel with a trapezoidal thread, the width of the thread head, the axial projection of the right side of the thread, the width of the hollow of the coil, and the axial projection of the left side of the thread are made equal and equal to the height thread winding.

Due to the proposed dimensions of the main thread parameters, the following is achieved; its positive effect:

Because it is assumed that a b c t h 2 mm, then the thread pitch P a + b + c + t 8 mm.

From the fact that, it follows that the SS is 45 °, then by (1)

T arctg 9.47. 3.14-21

9. (2)

arctg fn, (3)

, (4) cos a

, 15 / cos40 0.1958,

eleven

a no (3) 12%

because 6.9 ° 12 °, TO in accordance with (2), we can conclude that the proposed thread is self-braking with a guaranteed safety margin from self-unscrewing 12/6,, 7.

l} foj (/

. 0.212, cos 45

Sources:

1. Lukyanov V.G., Gromov A.D., Pinchuk N.P. Mining and exploration technology: Textbook for high schools. - Tomsk: Vol. Univ., 1999.-452 p.

2. Anchor support made of steel reinforcing screw profile from 07/01/1999.

3. Certificate of conformity. No.ROSS RU. MSh04.VOOO 1. No. 4812651.

4. Resolution of the Gosgortekhnadzor of Russia No. РРС04-22 dated February 19, 1999

5. Anchor anchor A20V. Passport A20.OOOPS.

6. Ivanov M.N. Machine parts. Textbook for students of higher educational institutions. - 5th edition, revised. - M: Higher. Shk., 1991, - 383 s.

7.Mashnev M.M., Kraskovsky E.Ya., Lebedev P.A. Theory of mechanisms and machines and machine parts: Textbook. A manual for students of non-machine-building majors of universities. - 2nd ed., Revised. and add. - L .: Engineering, Leningrad. Sep, 1980 .-- 512 s.

Applicant: Director of Mining Instrument LLC

The authors

:; ; toto- r7 Dvornikov L.T.

 Prokushenko S.I.

Moshkin P.V.

, Vechujanin D.S.

Babanov A.I.

/ f / Prokushenko S.I.

Claims (1)

An anchor rod made of reinforcing steel with a trapezoidal thread, characterized in that at the anchor rod the width of the thread head, the axial projection of the right side of the thread, the width of the hollow of the coil, the axial projection of the left side of the thread are made equal and equal to the height of the thread.