CN2913578Y - Rotary digging driller mast - Google Patents

Abstract

The utility model discloses a mast for rotary drilling rig, which comprises a front panel and a rear box board. The front panel is provided with a recess groove. The cross-sectional shape of the rear box board is configured to a deep groove with one bottom edge, two vertical edges and slanting edges therebetween. The utility model is characterized in that the recess groove, received on the front panel, enables the downward shift of the neutral axis of cross sections of the mast, thereby increasing the bending strength of the whole mast.

Description

The rotary drilling rig mast

Technical field

The utility model relates to a kind of mast that is used for rotary drilling rig.

Background technology

At present, rotary drilling rig is applied to foundation construction field more and more widely.Because rotary drilling rig is highly higher after when work, mast erected, under the effect of pulling force, the mast body of rod is easy to generate flexural deformation.When the unit head output torque, mast is subjected to torsional moment in addition, can produce shear stress on its cross section.Based on above reason, require mast to have stronger bending resistance, anti-twisting property.And at present in engineering machinery field the cross sectional shape of rotary drilling rig mast adopt two kinds of loop configuration and box structures mostly, consider that from aspects such as technology, cost and rotary drilling rig design features box structure is more reasonable.But as shown in Figure 1, its body of rod 1 cross sectional shape of the mast of common box structure square-section is a rectangle, its bending resistant section coefficient is less, therefore the mast of this common box structure square-section is used in and can occurs on the large-tonnage rotary drilling rig rocking even producing than the macrobending phenomenon, shows the weakness of flexural strength deficiency.

The utility model content

The technical problem that the utility model solves is to provide a kind of flexural strength better rotary drilling rig mast.

Rotary drilling rig mast of the present utility model comprises front panel and rearing-box plate, and described front panel has groove.

Rotary drilling rig mast of the present utility model, the cross sectional shape of wherein said groove are " open channel " shape, and the cross sectional shape of described rearing-box plate is the deep trouth shape that has a base, has hypotenuse to connect between two vertical edges, vertical edges and the bases.

Rotary drilling rig mast of the present utility model by on the plate groove being set in front, moves down the neutral axis in rotary drilling rig mast cross section, thereby has strengthened the flexural strength of whole mast.

Description of drawings

Fig. 1 is the cross sectional view of rotary drilling rig mast in the prior art;

Fig. 2 is the cross sectional view of the utility model rotary drilling rig mast one embodiment.

The specific embodiment

It comprises front panel 1 and rearing-box plate 2 one embodiment of the utility model rotary drilling rig mast that reference is shown in Figure 2, wherein have the groove 2 that cross sectional shape is " open channel " shape on the front panel 1, the cross sectional shape of rearing-box plate 2 is the deep trouth shape that has a base, has hypotenuse to connect between two vertical edges, vertical edges and the bases.

When rotary drilling rig was worked, under the effect of pulling force, its mast was subjected to the moment M effect, and it can make the bending of mast generation transversal force, and this moment, mast cross section internal force mainly showed as normal stress:

$\mathrm{\σ}=\frac{M}{W}---\left(1\right);$

In the formula: $W=\frac{I_z}{y}---\left(2\right)$ Be the bending resistant section coefficient;

I _Z=∫ _Ay ²FA (3) is a second moment of area;

Y be in the cross section any point to the distance of neutral axis.

Can be learnt by following formula: normal stress and bending resistant section coefficient W are inversely proportional to, and W is relevant with cross-sectional geometry, the mast cross section is inner when unit head is in running order in addition can produce shearing force, according to the principle of work and power: on the cross section moment of couple T with add torsional couple square m work done and equate, can draw mast rod member angle of torsion on unit length $\mathrm{\Φ}=\frac{\mathrm{mS}}{4G{\mathrm{\ω}}^2\mathrm{\δ}}$ (4)

In the formula:

S is the cross section midline length;

G is a shear modulus;

ω is the area that the cross section center line is surrounded;

δ is the cross section wall thickness.

For a concrete box structure a definite neutral line is arranged all the time, according to the box structure of the utility model rotary drilling rig mast as can be known: the ordinary rectangular cross section structure of rotary drilling rig mast is compared in the prior art as shown in Figure 1 all identical with its maximum appearance and size and wall thickness, the neutral axis in the utility model rotary drilling rig mast cross section offsets downward, just the y value increases, again because maximum occurs in from the neutral axis farthest, according to formula (1), (2), (3) as can be known: the ordinary rectangular cross section structure that the utility model box structure is all identical with wall thickness with maximum appearance and size its flexural strength of comparing is stronger.

Claims (2)

1, a kind of rotary drilling rig mast comprises front panel (1) and rearing-box plate (2), and it is characterized in that: described front panel (1) has groove (2).

2, rotary drilling rig mast according to claim 1, it is characterized in that: the cross sectional shape of described groove (2) is " open channel " shape, and the cross sectional shape of described rearing-box plate (2) is the deep trouth shape that has a base, has hypotenuse to connect between two vertical edges, vertical edges and the bases.

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