RU2234228C1 - Needle cutting method - Google Patents

Abstract

FIELD: methods for mechanical processing of materials by cutting, in particular, by needle cutting.

SUBSTANCE: method involves rotating needle cutter and moving it relative to work piece under process, with coarse and final needle cutting being performed by needle cutters of different rigidity and different density of pile pack. Method is effectuated by means of apparatus having casing with spindle incorporating two immovably fixed flanges and additional flange positioned for axial displacement. Apparatus is provided with mechanism for axial displacement of additional flange. Method may be used for trimming of welded joints and for cleaning of surfaces of articles from metal and other materials from corrosion and scale.

EFFECT: increased efficiency and improved quality of processing of surfaces.

2 cl, 5 dwg

Description

The invention relates to mechanical engineering technology, and in particular to methods of machining materials by cutting and needle-milling, as well as stripping welds and cleaning surfaces of metals and other materials, for example, from corrosion and scale.

A known method of machining with a cylindrical brush containing a sleeve with disks mounted on it, each of which has peripheral holes for attaching V-shaped bundles of wire pile and flanges for fixing the disks on the sleeve [1].

The disadvantages of this method are the low efficiency of use due to the low density of the stuffing of the pile and its unreliable fastening, therefore, the brush has low rigidity, which does not allow to achieve high performance and to remove significant allowances with high quality, while narrow technological capabilities limit the scope.

A known method of machining with a cylindrical brush containing a sleeve with disks mounted on it, each of which has peripheral holes for attaching V-shaped bundles of wire pile and flanges for fixing the disks on the sleeve, each pile of tuf being fixed to the disk in such a way that the section of its bend is placed between a pair of holes, and its free ends pass through the holes and are located radially with respect to the axis of the sleeve, while the distance between the axes of each pair of holes of the disk is not Witzlaus twice the hole diameter, wheels mounted offset relative to one another so that one pile tufts are located between beams of other, and the distance between the axes of two holes arranged along the length of the sleeve disc is equal to half the distance between the axes of the pair of holes in the disk [2].

The disadvantages of this method are the low degree of mechanization of the set-up work of needle-milling, which requires large manual expenditures of effort and time to change and adjust the stiffness of the brush and the density of the stuffing pile when changing the nature of the work when switching from light to heavy power working conditions and vice versa, in addition, it is not possible quickly respond to changes in hardness and strength of the processed material, etc.

The objective of the invention is the expansion of the technological capabilities of the method through the use of a semi-automatic device for changing the rigidity of the needle cutter and the density of the pile, which allows you to change the processing efficiency with reliable fastening of the pile with high-performance and high-quality removal of significant allowances and work in difficult power conditions.

The problem is solved using the proposed method of needle milling, in which the needle is rotated and moved relative to the workpiece, and rough and fine needle milling is performed at different stiffness of the needle and various densities of the pile packing carried out by a device containing a body with a spindle on which two flanges are mounted fixed fixed, and an additional flange mounted with the possibility of movement in the axial direction, as well as the axial mechanism emescheniya additional movable flange.

In addition, the two fixed flanges mentioned provide the minimum rigidity with which fine needle-cutting is carried out, and roughing with the removal of significant allowances is carried out by more rigid needle-cutting, with additional rigidity provided by an additional flange.

Figure 1 presents the design of a device that implements the proposed method; figure 2 - the working position of the needle cutter with the most diluted flanges for finishing; figure 3 - the position of the needle with maximum rigidity for roughing; figure 4 - assembly diagram of the needle cutter; figure 5 is a section aa in figure 1.

The proposed method of needle milling involves rotating the needle and moving it relative to the workpiece.

The features of the method are that rough and fine needle-milling is carried out with different rigidity of the needle-mill and different density of the pile packing, carried out by a special device that implements the proposed method.

The device comprises a spindle 1, which is mounted using bearings 2 and 3 for rotation in the housing 4. To rotate the spindle, a pulley 5 is used, connected by an endless belt 6 to the pulley 7 of the drive motor 8, mounted, for example, on the housing 4.

On the spindle 1 between the flanges 9 and 10 are installed disks 11 with V-shaped bundles of wire pile.

On the spindle 1 between the flange 9, fixedly mounted using nuts 12, and the axial movement mechanism 13 mounted movable flange 14, which has the ability to move along the spindle 1.

On the spindle 1 between the fixed flange 10 and the housing 4 is mounted an axial movement mechanism 13 with a movable element — a piston 15, to which a movable flange 14 is attached, or, as shown in FIG. 1, the movable flange 14 is made integrally with the piston 15. In the hole piston 15 on the spindle 1 between the fixed flange 10 and the piston 15 is installed compression spring 16.

The axial movement mechanism 13 can be made in the form of a power cylinder connected to a clutch 17 mounted on the non-working end of the spindle 1. In this case, the clutch 17 is connected to a pressure source of the working medium, for example, a hydraulic station or a pneumatic network.

The cylindrical needle-cutter contains disks 11, each of which has peripheral holes 18 for attaching V-shaped bundles 19 of wire pile and flanges 9 and 10 for fixing the disks 11 on the spindle 1. Each V-shaped bundle 19 of the pile is mounted on the disk 11 so that the section of its bend is placed between the pair of holes 18, and its free ends pass through these holes and are located radially with respect to the axis of the spindle 1. The distance between the axes of each pair of holes of the disk 11 does not exceed twice the diameter d of the hole. The disks 11 are mounted with an offset relative to each other so that the tufts 19 of the pile of one of them are located between the tufts of the other. The distance l between the axes of the holes 18 of two adjacent disks 11 located along the length of the spindle 1 is equal to half the distance L between the axes of the pair of holes 18 in the disk.

Assembly of acupuncture is as follows.

A wire is cut from the bay and bundles are dialed with a diameter close to the diameter of the hole 18. Then the bundles are bent and threaded into the adjacent holes 18 of the disk 11, after which they are bent again in the radial direction of the disk. Then the disks 11 are put on the working end of the spindle 1 against the stop in the flange 10 and are fixed on the opposite side by the other flange 9, followed by tightening with the nuts 12. The disks 11 are mounted on the spindle so that the tufts of pile on one disk are located between the tufts of pile on a nearby standing disk .

Acupuncture is used as follows.

An acupuncture is mounted on a spindle, to which rotation is communicated, and brought to the work surface. The ends of the wire pile, interacting with the treated surface, carry out micro-cutting.

Roughing with the removal of significant allowances is carried out by a stiffer needle cutter, with additional rigidity provided by an additional flange 14, which is brought closer to the flange 9 due to the inclusion of the axial movement mechanism 13 (see Fig. 3), which, as under the press, increases the density of the pile packing and rigidity of acupuncture.

Fine needle-milling, as well as other light types of work: cleaning surfaces of metals and other materials, for example, from corrosion, scale, cleaning welds and burrs, are carried out by needle-cutting with minimal rigidity, for which, on the go, without stopping the process, turn off the axial movement mechanism 13 and under the action of the spring 15, the additional flange 14 is diverted from the needle cutter (see figure 2).

Example. The workpiece was machined from a hot-rolled strip of steel 20 according to the proposed method on a modernized horizontal milling machine mod. 6R82G. The modernization consisted in equipping the spindle with a pneumatic cylinder to further increase the rigidity of the needle cutter. A steel spring wire with a diameter of 0.5 ... 1.0 mm from 65G steel was used as a pile. An acupuncture was used with an h / i ratio, where h is the length of the pile over the flanges; i is the smallest inertia radius of the cross section of the wire elements, which is in the range of 50 ... 100, and the coefficient K _{p of the} density of the wire pile is in the range of 0.6 ... 0.7 for finishing and 0.8 ... 0.9 for roughing, while the tightness was H = 0.7.,. 1.0 mm for finishing and H = 1.2 ... 1.5 mm for roughing [3].

Operating modes: peripheral speed for roughing 2 ... 3 m / s, for finishing - 4 ... 5 m / s. The longitudinal feed was determined by the formula S = h · n (mm / min), where n is the speed of the device, min ^-1 ; the value of h (mm) depends on the interference and the diameter of the disk and was determined empirically.

Processing showed that the needle cutter during roughing cuts off scale from the surface to be treated together with a hardened layer; during fine needle-milling, the roughness improves by one class, the force of pressing the needle-cutting to the workpiece surface was 200 ... 300 N and 400 ... 600 N per 10 mm of the width of the working surface of the needle-cutting machine, respectively, during finishing and roughing, and the tangential component of the cutting force at this was 150 ... 250 N and 450 ... 550 N, respectively, during finishing and roughing.

When processing the proposed method, the condition was met:

for finishing

To _p = p / σ _in = 1.5 ... 1.7;

for roughing

To _p = p / σ _in = 1.8 ... 2.0,

where p is the pressure of the needle on the treated surface, MPa;

σ _in - the tensile strength of the material of the workpiece, MPa.

The choice of the corresponding pressure p depends on the physicomechanical properties of the material of the wire pile, on the rigidity and density of the latter, as well as on the interference fit [3].

Using the proposed method allows to expand the technological capabilities of needle cutting, to increase the efficiency of using a needle mill with reliable fastening of the wire pile by increasing the density of the pile and increasing the rigidity. The reliability of the pile fastening and the stiffness control also allows high-performance removal of significant allowances, i.e. to work in severe power conditions, to predict the roughness and quality of the processed surface.

Sources of information

1. US patent No. 2983940, CL. 15-181, 1961.

2. A.S. USSR 1431726, MKI A 46 B 7/10. Cylindrical brush. Abugov L.G., Bogdanov L.N., Bogdanov V.N. and other Application No. 4109194 / 27-12, decl. 06/17/86, publ. 10.23.88. Bull. No. 39 is a prototype.

3. Gavrilenko I.G. A method of combining preliminary and final needle-milling stripping of cylindrical parts. // Automation and modern technology. - 1992. - No. 9. - S.27-30.

Claims (2)

1. The method of needle milling, in which the needle is rotated and moved relative to the workpiece, characterized in that the rough and fine needle milling is performed at different stiffness of the needle and various densities of the pile packing, carried out by a device containing a housing with a spindle on which two flanges are mounted, fixed motionless, and the additional flange is mounted for axial movement, as well as the axial movement mechanism of the movable additional Lanza. 2. The method according to claim 1, characterized in that the two said fixed flanges provide the minimum rigidity with which fine needle-cutting is carried out, and roughing with the removal of significant allowances is carried out by a more rigid needle-mill, with additional rigidity provided by an additional flange.

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