SU1405994A1 - Method of preparing concrete mix during transportation of mixer truck - Google Patents

Abstract

The invention relates to vehicles with a rotating mixing drum and will improve performance by preventing the reduction of the transport speed of the concrete mixer on the turn. The method of preparing the concrete mix during transportation of the concrete mixer involves moving it in a mixing drum as it is delivered to the consumer. At the turn of the concrete mixer, the mixing drum is said to rotate in the direction opposite to the direction of rotation of the concrete mixer. The frequency of rotation of the mixing drum is determined from the ratio 2 7/7 / vVr about X tsin (5.5n-30) -sin (0.165n- 45) (0.165n-45) -cos (5.5n-30) 7y 1 where V is the speed of movement of the concrete mixer; g is the turning radius of the concrete mixer, g is the acceleration of gravity, g is 9.81 m / s, and n is the frequency of rotation of the mixing drum. 6 Il. with S (L

Description

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The invention relates to vehicles with a rotating working capacity and can be used: in auto concrete mixers.

The aim of the invention is to increase productivity by preventing the reduction of the transport speed of the concrete mixer in the short run,

Figure 1 shows a diagram of the rotation of a concrete mixer when turning shravo; figure 2 - the same, with a left turn; Fig. 3 is a diagram of the action: w forces arising from the turn of an concrete-concrete mixer with a fixed shifting drum; Fig. 4 shows a key with a mixing drum rotating in the opposite direction from the direction of movement of the Zetonosm auto mixer; Fig. 3 is a diagram of the location of the center of mass of the concrete mixture at the different direction of rotation of the drum; Fig. 6 is a graph of the frequency of rotation of the mixing drum of the concrete mixer truck versus the turning radius of the machine r at a speed of 1Г 4; eight; 12 m / s.

The method is carried out as follows.

The concrete mixing drum is: the kneader is loaded with components of a concrete mixture or ready-mixed concrete. The drive of the basic passi and the mixing drum is turned on, the auto concrete mixer transports the prepared mixture to its destination. When turning, the rotation of the drum is switched to the side, against (:: 1) the direction of its rotation.

The initial information for the driver to switch the mixing drum to one or the other side is the angle of the steering wheel rotation, the excess of which implies the obligatory switching on of the mixing drum in order to stabilize the repetition process, i.e. achieving the possibility of turning at a higher speed; ipocTH.1 The magnitude of the rotation frequency of the drum is determined by the driver according to the schedule n f (V, R) (Fig. 6), - respectively, the speed of movement and minimum) turning radius: concrete mixer. Entry into a car-mixer in a turn is usually dried by a transition curve, for example, a clothoid. The most dangerous is the final (minimum g; lny) turning radius. Kosveiig) and an estimate of the turning radius for driving ;; is the steering angle.

The described operations for controlling the process of turning on and off the mixing drum can be carried out automatically with the help of various devices.

When the drum rotates clockwise, all the material at an angle of repose is placed in the front of the drum. The height of the center of mass is above its position with the horizontal arrangement of the free surface. When the drum rotates counterclockwise (for unloading), the material goes to the discharge part of the drum and its extreme placement (with cover) does not exceed the primary value of the height of the center of mass. As a result, the weight of the concrete mix prevents the mixer from tipping over.

The frequency of rotation of the mixing drum in the truck mixer is determined from the ratio

2 .Y. . iisiUs: 3oirJisi 2 ws: | L ,,

 r-g owls (0.165n-45) -coe (5.5n-30 ()

where V is the speed of movement of the concrete mixer;

g - the radius of rotation of the concrete mixer;

n is the frequency of rotation of the mixing drum;

g — free fall acceleration g 9.81 m / s (see FIG. 4) —depends on the frequency of rotation of the mixing drum and is related to the frequency of rotation through the relation:

H f (,;%)

where Lf and Lf - initial and final

the angles of the concrete mix in the mixing drum; u and (- obtained experimentally} {by the ideal method I 1 / 0.165p - 43 Lf5 5.5p - 30

Fia-based animal testing. Research with rioc t Precise 1 and iTric. i bank stable1 g and

V- iO t j -

g-k1: I am U, - in- (.f ,,

Since the increase in the frequency of the puff of the mixing drum increases the power of its drive, the stability after its fishing speed will be equal to

.g

V r-g

sin t / j - sintfi

-

cos V, COS tfj

practically does not increase, it is advisable to take the rotational speed of the mixing drum equal to

.Y. "I li5 55 :: 30i; sini0 165nr40l t.gco (0,165n-45) -coe (5,5n-30)

Considering that the transport speed of loaded concrete mixers does not exceed V 60 km / h, and the turning radius, as a rule, lies in the range of 5-30 m, the rotational speed of the mixing drum on the basis of the ratio set out is equal to n 3 - 20 rpm .

In order to turn the mixing drum towards the unloading, the concrete mixture does not start to be unloaded from the mixing drum, the number of its turns in this direction is limited and for the serial production of concrete mixers this value is N 3-7.

If necessary, the mouth of the mixing drum can be closed with a special device.

Claims (1)

Invention Formula The method of preparing the concrete mix during the transportation of the concrete mixer truck by moving it in a mixing drum, in order to increase productivity by preventing a decrease in transport 15 the speed of the concrete mixer on the turn, the concrete mixture on the turn of the concrete mixer is given a movement in the direction opposite to the direction of its rotation, at 20 than the frequency of rotation of the mixing drum is determined from the ratio 2,.-Y-- .5isib5n: 30ilSil i05, 4554545, cos (0,165n-45) -cos (5,5n-30) the speed of movement of the concrete mixer; turning radius avtobetonosmesitel; g - free fall acceleration, g 9,81 m / s 30 n is the frequency of rotation of the mixing drum. 25 r-g where v g Rig1 Rig.d Fig 5 Fi.C / 7, ff // W 20 18 7B 14 12 W 8 t 5 Ю 15 20 25 W 35, M Figure 6