RU2234583C1 - Hammer for percussion mechanism - Google Patents

Abstract

FIELD: machinery building, mining industry and building, particularly hammers.

SUBSTANCE: hammer has cylindrical piston part, cylindrical percussion part and cavity filled with material having specific weight different from that of main hammer material. Cavity has the shape of body of revolution. Radius of inner hammer cavity periphery in cross-section in any cut elementary layer is determined from the following equation:

where R is outer radius of cross section of main hammer material, ρ is reduced radius of hammer cross-section, λ is parameter indicating ratio of specific weights of main material and material located in hammer cavity.

EFFECT: provision of stable percussion mechanisms position into case, generation of smooth impulses having no steps.

3 dwg

Description

The invention relates to the field of engineering, mining and construction, in particular to the strikers of shock mechanisms.

Known firing pin, which is a rotational semi-catenoid [1, RU 2182953 C1, figure 2], which when struck by a waveguide forms in the last shock pulse of a smooth shape that does not have steps. The disadvantage of such strikers is the inability to integrate them into the body of the shock mechanisms, since they do not contain a piston stage that can provide them with a stable position in the body.

Known step striker of the percussion mechanism [2, p. 223, Fig. VII.3, e], which is characterized by the presence of two parts: piston and percussion, made in the form of cylinders. The disadvantage of such strikers is the fact that they form a shock pulse of a stepped form, which can lead to the occurrence of sudden changes in the forces in the waveguide and to its destruction.

The objective of the present invention is to develop such a striker, which, having a stable position in the body of the shock mechanisms, would generate a shock pulse of a smooth shape that does not have steps.

The essence of the invention lies in the fact that the striker of the percussion mechanism, equipped with cylindrical piston and shock parts, according to the invention contains filled with material, the specific gravity of which is different from the specific gravity of the main material of the striker, an internal cavity, the shape of which is a body of revolution, while the radius of the outer circle the said inner cavity of the striker in the cross section of any cut out elementary layer is determined by the formula:

where R is the outer radius of the cross section of the main material of the striker;

ρ is the reduced radius of the cross section of the striker;

λ is a parameter indicating the ratio of the specific gravities of the main material of the striker and the material of the internal cavity of the striker.

Figure 1 shows the proposed firing pin, section; figure 2 is a cross section of the elementary layer aa ’, b’-b; figure 3 - semi-catenoid rotation.

The proposed striker comprises a cylindrical piston part of the striker 1, a cylindrical shock part of the striker 2. In the main material of the striker is an internal cavity 3 filled with material with a specific gravity different from the specific gravity of the main material of the striker. Also in FIG. 1 shows an elementary layer aa ', b'-b of thickness Δx cut in a striker, and a waveguide 4 with a diameter of d ₀ , which strikes with a striker.

The drummer works as follows.

Compressed air or liquid acts on the end surface of the piston part 1, as a result of which the striker rushes to the left and strikes the waveguide 4. The energy stored by the striker is transmitted to the waveguide 4 in the form of an elastic wave. Moreover, due to the difference in the specific gravities of the material of the main body with the material placed in the internal cavity 3, the firing pin generates a wave pulse equivalent to the pulse generated by the rotational semi-catenoid.

We show the condition for the identity of the strikers shown in figure 1 and figure 3, according to the pulse generated by them.

In the cross section of any cut out elementary layer aa’’, b’-b of thickness Δx there is a ring formed by the main material of the striker and a circle formed by the material of the inner cavity of the striker.

The area of the ring formed by the main material of the striker:

where R is the radius of the outer circumference of the ring formed by the base material;

r is the radius of the inner circle of the ring formed by the main material, or the radius of the outer circle formed by the material of the inner cavity of the striker.

Layer volume of the base material:

The weight of the base material layer:

where γ ₁ is the specific gravity of the main material of the striker.

The area of the circle formed by the material of the inner cavity of the striker:

The volume of the layer of material of the inner cavity of the striker:

The weight of the layer material of the inner cavity of the striker:

where γ ₂ is the specific gravity of the material of the internal cavity of the striker.

We now turn to the semi-catenoidal striker (Fig. 3). The hammer in the form of a semi-catenoid of rotation [3, p. 171, Fig. 5, d] is a body of revolution made of solid material, the generatrix of which is a chain line - catena, which is described by the formula [4, p. 129, second column, 9- I line above]:

Cross-sectional area of a rotational semi-catenoid:

The volume of the elementary layer allocated in the semi-catenoid of revolution:

The weight of the elementary layer allocated in the semi-catenoid of revolution:

where γ ₃ is the specific gravity of the material of the semi-catenoidal hammer.

Given the fact that γ ₃ = γ ₁ between the reduced striker in the form of a rotational semi-catenoid (Fig. 3) and the stepped striker in Fig. 1, the connection in the form is obvious:

Where according to (1-6, 8-10)

From formula (12), assuming the shape of the main part of the striker, that is, R, to be known, one can find the radius of the circle formed by the material of the inner cavity of the striker, which is determined by the formula:

получаем:Marking through

we get:

which uniquely determines the shape of the internal cavity of the striker, in which the strikers shown in Fig. 1 and Fig. 3 will be identical in the momentum generated by them.

Thus, the striker, containing cylindrical piston and impact parts, filled with material, the specific gravity of which is different from the specific gravity of the main material of the striker, an internal cavity whose shape is a body of revolution, while the radius of the outer circumference of the inner cavity of the striker is in cross section any cut out elementary layer is determined by the formula (14), the reduced specific gravity will be a semi-catenoid of revolution.

Used sources

1. Patent No. 2182953, cl. E 21 V 1/38, B 25 D 17/02.

2. Alimov O.D., Dvornikov L.T. Drilling machines, M., Mechanical Engineering, 1976.

3. Ultrasound. Little Encyclopedia. M., Soviet Encyclopedia, 1979

4. Bronstein I.N., Semendyaev K.A. Math reference book for engineers and college students. Edition 13, revised, M., Science, 1986

Claims (1)

The striker of the percussion mechanism, containing cylindrical piston and impact parts, characterized in that it contains a material filled, the specific gravity of which is different from the specific gravity of the main material of the striker, an internal cavity whose shape is a body of revolution, while the radius of the outer circumference of the said inner cavity of the striker the cross section of any cut out elementary layer is determined by the formula

, where R is the outer radius of the cross section of the main material of the striker; ρ is the reduced radius of the cross section of the striker; λ is a parameter denoting the ratio of the specific gravities of the base material and the material of the internal cavity of the striker.

Images