RU2508187C1 - Separation method of rod into long workpieces - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: rod is supplied till a separation plane is aligned with an introduction plane of a wedge tool made in the form of a roller with a V-shaped working edge. Rotational movement is given to the wedge tool. A deforming force is applied to the wedge tool simultaneously with application of a pressure force to a cantilever end of a long workpiece. A V-shaped groove is formed in a rod separation plane. The long workpiece is separated from the rod. The pressure force to the cantilever end of the long workpiece and the deforming force to the wedge tool are applied on one side relative to the rod axis in a common longitudinal radial plane having the possibility of rotational movement about the longitudinal axis of the rod. Values of periodically alternating tensile and compressions stresses in the rod separation plane are set in the range of the value of metal limit of elasticity at implementation of the wedge tool till the value is not lower than the value of metal shear yield point by the time the long workpiece has been separated from the rod.

EFFECT: improving quality of long workpieces.

2 dwg, 1 ex

Description

The invention relates to the field of metal forming and can be used, in particular, for dividing the bar into lengthy workpieces.

A known method of cutting wire into measured billets, which consists in feeding the material to the stop and cutting it into measured billets with movable knives rotating towards each other (USSR author's certificate 716683, M.cl. 2 B21F 11/00).

Using this method allows to increase cutting performance due to the simultaneous cutting of two dimensional blanks. However, the resulting workpieces are of poor quality due to the inevitable formation of defects in the form of weights and wrinkles of the end sections of the workpiece, as well as the occurrence of burrs on the end edges of the measured workpiece (Forging and stamping. Handbook in 4 volumes T.1. Ed. E.I. Semenova, Moscow: Mashinostroenie, 1985, p. 171).

A known method of dividing the bar into long workpieces, which consists in feeding the bar until the separation plane is aligned with the insertion plane of the wedge tool, made in the form of a roller with a V-shaped working edge, communicates rotary motion to the wedge tool and applies a deforming force thereto, forming a V-shaped groove in the plane of separation of the bar, the application of pressure to the cantilever end of the measured workpiece and its separation from the bar by the destruction of the metal along the notch plane. Obtained by this method, lengthy workpieces have face chamfers, which increases their quality. This technical solution is the closest in the set of essential features and was adopted as a prototype (Forging and stamping. Handbook in 4 vols. T.1. Edited by E.I.Semenov. M .: Mechanical Engineering. 1985. - S. 165).

The main disadvantage of the described method of dividing the bar into long billets is the reduced quality of the measured billets, due to the large roughness of its end surfaces, since the measured billets are separated by tearing it from the bar with the destruction of the metal along the notch plane (Forging and stamping. Handbook in 4 t T.1. Edited by EI Semenov. M.: Mechanical Engineering. 1985. - P.165).

The basis of the invention is the task of improving the quality of lengthy workpieces.

To solve the problem in the method of dividing the bar into lengthy workpieces, which consists in feeding the bar until the separation plane is aligned with the insertion plane of the wedge tool made in the form of a roller with a V-shaped working edge, the wedge tool is rotated and the deforming force is applied to it, forming V-shaped grooves in the plane of separation of the bar, the application of pressure to the cantilever end of the long workpiece and its separation from the bar, according to the invention with The pressing force is brought to the cantilever end of the long workpiece simultaneously with the application of the deforming force to the wedge tool, while the pressing force to the cantilever end of the long workpiece and the deforming force to the wedge tool are applied one-sided with respect to the axis of the bar in a common radial longitudinal plane that can rotate around the longitudinal axis of the rod, and the values of periodically alternating tensile and compression stresses in the plane of separation of the rod they are pressed in the range from the value of the elastic limit of the metal at the time of introduction of the wedge tool to a value not less than the value of the yield strength of the metal at a shift to the moment of separation of the measured workpiece from the bar.

By the simultaneous unilateral application of pressing and deforming forces with their placement in a common longitudinal radial plane, which has the possibility of rotational movement around the longitudinal axis of the bar, in the proposed method of dividing the bar into long billets create a circular alternating bending moment, and the values of periodically alternating tensile and compression stresses in the separation plane the bar is set in the range of change from the value of the elastic limit of the metal at the time of implementation of the wedge ment to a value not less than the value of the yield strength of the metal to shear by the time the measured billet is separated from the rod, than they cause intragranular shear deformation with the formation of a fatigue fracture surface of the metal in this plane by the time the measured billet is separated from the bar (Tension, deformations, fracture. L. Publishing house "Metallurgy", 1970, p. 56-60). As a result, dimensional blanks with smooth end surfaces and end facets are obtained, which ensures high quality of lengthy blanks.

The proposed invention is illustrated by drawings, where figure 1 shows the start of the process of dividing the bar into long workpieces, figure 2 - the moment of separation of the long workpiece from the bar.

The method of dividing the bar into long workpieces consists in supplying the bar until the separation plane is aligned with the introduction plane of the wedge tool, made in the form of a roller with a V-shaped working edge, inform the wedge tool of the rotational movement and apply a deforming force to it simultaneously with the application of pressing force to the cantilever end of a lengthy workpiece. The pressing force to the cantilever end of the long workpiece and the deforming force to the wedge tool are applied one-sidedly with respect to the axis of the bar in a common longitudinal radial plane having the possibility of rotational movement around the longitudinal axis of the bar. The values of periodically alternating tensile and compression stresses in the plane of separation of the bar are set in the range from the value of the elastic limit of the metal at the time of introduction of the wedge tool to a value not less than the value of the yield strength of the metal at a shift to the moment of its destruction in the separation plane. A V-shaped groove is formed in the plane of separation of the bar, and the lengthy workpiece is separated from the bar.

The method of dividing the bar into lengthy workpieces is implemented as follows. The rod 1 through the guide sleeve, for example, a split collet 2 of the collet 3, is fed with rollers 4 and 5 into the rod 1 rotating around the axis 6, coinciding with the longitudinal axis 7, the rotor 8, rigidly connected with the drive element 9, for the length of the measured workpiece 10 to the spring stop 11, and clamp, for example, in the collet chuck 3 by moving the sleeve 12 along the split collet 2. The plane 13 of the separation of the rod 1 is combined with the plane 14 of the introduction of the wedge tool, made in the form of a roller 15 with a V-shaped working edge 16, installed in holder 1 7, and the cantilever end 18 of the measuring workpiece 10 is located opposite the pressure roller 19 with a rounded working surface 20 installed in the holder 21. The holders 17 and 21 are placed in the wall 22 of the rotor 8 one-sidedly relative to the axis 6 of rotation of the rotor 8 with the possibility of radial movement in the plane 23 including the longitudinal axis 24 and 25, respectively, of the rollers 15 and 19 and the longitudinal axis 7 of the rod 1 (figure 1).

Then move the pressure sleeve 26 with the working surface 27 made with bevels α and β, acting on the pressure balls 28 and 29 installed in the holders 17 and 21, the centers of which are placed in the plane 23 (Fig. 1), creating by means of radial movement of the holders 17 and 21 deforming and pressing forces, respectively, on the rollers 15 and 19.

Since the unilateral application of deforming and pressing forces placed in one radial plane 23, with the possibility of rotational movement around the longitudinal axis 7 of the rod 1, in the plane 13 of the separation of the rod 1 by means of the roller 15 form a V-shaped groove 30, and the pressure roller 19 by deflecting the cantilever the end of the 18 dimensional workpiece 10 in this plane create a circular alternating bending moment, with periodically alternating tensile and compression stresses cause intragranular shear deformation in the plane section 13 of the separation of the rod 1, which leads to the formation of smooth end surfaces of the measured billet 10, perpendicular to its longitudinal axis 31 (figure 2), while the stress value is set in the range from the value of the elastic limit of the metal at the time of introduction of the roller 15 into the separation plane 13 rod 1 to a value not less than the limit of the shear strength of the metal by the time of its destruction in the plane 13 of separation and separation of the measured workpiece 10 from the bar 1. Separated from the bar 1 long workpiece 10 is removed from the rotor 8 h Res window 32 formed in a wall 22 (Figure 2).

Example. A batch of long workpieces with a diameter of d = 24 mm and a length of l = 52 mm, with end facets of 2 × 45 °, was obtained. Material steel 30; tensile strength of steel 30 σ _in = 500 MPa; yield strength σ _m = 300 MPa (Forging and stamping. Handbook in 4 volumes of Vol.

The calculation of the process parameters of the process is carried out in the following order.

1. Determine the magnitude of the pressure from the ratios:

$$M_{\mathrm{and}sg}={\sigma }_{\mathrm{at}}\cdot W_{\mathrm{and}sg},\mathrm{to}g\cdot m;(\mathrm{one})$$

$$M_{\mathrm{and}sg}=P_n\cdot l,\mathrm{to}g\cdot m;(2)$$

where M _izg - bending moment in the plane of separation of the bar into measured billets;

σ _y is the elastic limit of steel, MPa; take σ _y = σ _m (Polytechnical Dictionary. Ch. ed. I.I. Artobolevsky. - M.: Soviet Encyclopedia, 1977. - p. 386);

- момент сопротивления сечения, мм³, $$W_{\mathrm{and}sg}=\frac{\pi \cdot d_{\mathrm{to}}^3}{32}$$

- the moment of resistance of the cross section, mm ³ ,

where d _k is the diameter of the wedge groove; d _k = d-2 · h = 24-2 · 2 = 20 mm;

h - 2 mm - bevel depth;

P _n - pressure, kg

$$P_n=\frac{{\sigma }_y\cdot W_{\mathrm{and}sg}}{\mathrm{one}}=\frac{300\cdot \pi \cdot {\mathrm{twenty}}^3}{52\cdot 32}=4529H=453\mathrm{to}g$$

2. Determine the magnitude of the deviation of the cantilever part of the measured billet under the action of pressure (Bezukhov NI Theory of elasticity and plasticity. - M .: State Publishing House. 1953. - p.150).

$$f=\frac{{\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="00000009.png"\; state="\{\{state\}\}">l</figure-callout>}}^2\cdot M_{\mathrm{and}s\mathrm{<figure-callout\; id="2"\; label="g"\; filenames="00000009.png"\; state="\{\{state\}\}">g</figure-callout>}}}{2\cdot E\cdot I_{\mathrm{and}sg}},mm,(3)$$

where f is the deviation of the cantilever part of the measured workpiece, mm; E = 2 · 10 ⁵ - modulus of elasticity of steel, MPa;

- момент инерции поперечного сечения в плоскости $$I_{\mathrm{and}sg}=\frac{\pi \cdot r^{\mathrm{four}}}{\mathrm{four}}$$

- moment of inertia of the cross section in the plane

separation of the rod, mm ⁴ ;

r is the radius of the workpiece, mm; r = 0.5 · d = 0.5 · 34 = 17 mm;

$$f=\frac{{52}^2\cdot 453\cdot 52\cdot \mathrm{four}}{2\cdot 2\cdot {10}^5\cdot 3.14\cdot {10}^{\mathrm{four}}}=0.20mm.$$

3. The number of cycles (rotor revolutions) required to obtain the surface of the fatigue fracture and the separation of the measured workpiece from the bar is determined.

To do this, according to the schedule (Stress, strain, fracture. V. Kolmogorov, Metallurgy Publishing House, 1970, p. 59, fig. 30) for steel 30, the total degree of shear strain (Λ _Σ ) equal to Λ _Σ = 6, and according to the value on the graph, the number of cycles (N) is found equal to N = 6.

4. Determine the angle (α) of the bevel of the pressure sleeve 26 for radial movement of the holder 17.

Take a rotor speed of 8 120 rpm, a longitudinal feed (S _p ) of the pressure sleeve 26 S _p = 4 mm / rev. Then

tgα = h / S _n = 2/4 = 0.5; α = 27 °.

Here h = 2 mm is the height of the end facet (by condition).

5. Determine the angle (β) of the bevel of the pressure sleeve 26 for radial movement of the holder 21:

tgβ = f / S _n = 0.2 / 4 = 0.05; β = 3 °.

In the 6-cycle process of separating the measured workpiece from the bar, the stroke (L) of the movement of the pressure sleeve 26 was L = N · Sn = 6 · 4 = 24 mm.

6. Determine the yield strength of the metal by shear according to the known formula

τ _S = 0.58 σ _S ,

where τ _S is the yield stress of metal on shear, MPa;

σ _S - deformation resistance, MPa;

for practical calculations take σ _S ≈σ _in . Then

τ _S = 0.58 · σ _in = 0.58 · 500 = 290 MPa.

The obtained lengthy workpieces had end facets and smooth end surfaces perpendicular to the longitudinal axis.

Thus, the implementation of the proposed method can significantly improve the quality of long workpieces obtained from the bar.

Claims (1)

A method of dividing a bar into long workpieces, including feeding the bar until the separation plane is aligned with the insert plane of the wedge tool made in the form of a roller with a V-shaped working edge, communicating rotary motion to the wedge tool and applying a deforming force to it, forming a V-shaped groove in the plane the separation of the rod, the application of pressure to the cantilever end of a long workpiece and its separation from the bar, characterized in that the application of pressure to the cantilever the end of the long workpiece is carried out simultaneously with the application of the deforming force to the wedge tool, while the pressing force to the cantilever end of the long workpiece and the deforming force to the wedge tool is applied one-sidedly with respect to the axis of the bar in a common longitudinal radial plane that has the possibility of rotational movement around the longitudinal axis of the bar, and periodically alternating tensile and compression stresses in the plane of separation of the bar is set in the range from the value of pr metal case elasticity at the time of introduction of the wedge tool to a value not less than the yield strength of the metal values to shift the time separation of the preform rod lengthy.

Images