RU2334591C1 - Device for combined pin turning processing of screws - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: device includes front and back orbital stocks and cutter. Front stock includes outer and inner eccentric shells, the inner shell holding a spindle with a blank, rotating independently around orbital axis. Internal eccentric shell with 'e' eccentricity has separate orbital rotation drive against central axis, while the cutter is mounted in cutter holder on a transverse rest and has separate transverse feed drive. The device features cutting pin tool mounted opposite to threaded cutter. Pin tool has separate transverse manual drive and is intended to function as a mobile support holder loaded by blank clamping force equal to cutting force exerted by the threaded cutter. Lengthwise movement of transverse rest is kinematically connected to orbital rotation of a blank on the condition of a distance covered by a rest with cutter and pin tool per one turn of orbital axis equal to the processed spiral surface pitch.

EFFECT: extended technological possibilities.

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Description

The invention relates to mechanical engineering in the field of machine tool engineering and mechanical engineering technology, can be used for high-speed turning of screw surfaces of precision screws from hard-to-handle materials in combination with acupuncture.

A device is known for turning eccentric screws with an eccentricity “e”, comprising planetary front and rear heads and a cutter, while the front head contains external and internal eccentric sleeves, the last of which contains a spindle with a workpiece independently rotating relative to the planetary axis, while the internal the eccentric eccentric sleeve has an individual planetary rotation drive relative to the central axis, and the cutter is mounted in the tool holder on the transverse support and an independent drive infeed [1].

The known device has significant disadvantages. The process of forming a threaded surface is intermittent and is characterized by shock loads that cause vibrations that reduce tool life, productivity and machining quality. In this case, the unilateral action of the cutting force in the transverse plane causes a longitudinal deflection of a long non-rigid workpiece, which also reduces the quality and productivity of processing.

The objective of the invention is to expand the technological capabilities of high-speed turning of helical surfaces of precision screws from difficult to machine materials, which allows to increase tool life, productivity and quality of processing by additional communication of the planetary motion blanks, as well as to reduce the longitudinal deflection of a long non-rigid screw blanks by installing an additional support equipped with a needle cutting element .

The problem is solved using the proposed device for turning eccentric screws with an eccentricity "e", containing planetary front and rear headstock and cutter, while the front headstock contains external and internal eccentric sleeves, the last of which contains a spindle independently rotating relative to the planetary axis billet, while the inner eccentric eccentric sleeve has an individual planetary rotation drive relative to the central axis, and the cutter is set in the tool holder on the transverse support and has an independent transverse feed drive, and it is equipped with a cutting needle tool installed diametrically opposite to the threaded cutter, the cutting needle tool has an independent manual transverse feed drive and is designed to perform the function of a movable lunette, loaded with a pressing force to the workpiece equal to the cutting force developed by the threaded cutter, and the longitudinal movement of the transverse caliper is kinematically connected with the planetary we take the workpiece from the condition that the caliper displacement is equal with the needle tool per revolution of the planetary axis to the step of the machined helical surface.

Design features of the device are illustrated by drawings.

Figure 1 shows a diagram of the processing of a screw workpiece using the proposed device for acupuncture processing of screws with the installation of the workpiece in the chuck of a lathe with planetary movement of the spindle and preloading by the rear center, which also performs planetary movements, top view; figure 2, 3, 4 - section aa in figure 1 of the front headstock of a lathe with planetary movement of the spindle, which shows the relative position of the spindle, inner and outer eccentric sleeves; figure 5 - section bb in figure 1, the device for fastening the threaded cutter in the tool holder on the transverse caliper; in Fig.6 is a section GG in Fig.1, the device for attaching the needle tool in the tool holder on the transverse support; Fig.7 is a section bB in Fig.1; on Fig is a diagram of the processing of the subsequent section of the screw of the proposed device and the relative position of the workpiece and tools when turning the workpiece half a turn, top view.

The proposed device is intended for roughing and semi-finishing of screws 1 with eccentric screw surfaces having an eccentricity "e", with a threaded cutter 2 in combination with a needle tool 3. The operation of the device for needle-turning processing of screws, for example, screws of oil pumps operating in the oil industry, includes the message of the workpiece screw 1 of independent rotational movement with a speed of V _W , which determines the cutting speed and assigned depending on the cutting properties of the tool. This independent rotational movement V _{З of the} workpiece is carried out relative to the planetary axis О _П , offset from the central axis О _{Ц of the} workpiece by the eccentricity value "e".

In addition, a planetary rotational movement V _P relative to the central axis O _C is kinematically connected with the longitudinal feed S _{PR of} tools 2 and 3. This means that when the planetary axis O _{P is} rotated about the central axis O _C by one revolution, the transverse support 4 with tools 2 and 3 will move in the longitudinal direction by the step size “t” of the machined screw surface.

The device provides simultaneously with turning turning to carry out processing with a needle tool. To this end, in a diametrically opposite place relative to the threaded cutter 2, a tool holder 5 with a cutting needle tool 3 is installed on the transverse support 4, which is a bundle of wire pile fixed in a holder 6 in a known manner. The tool holder 5 with a cutting needle tool 3 has an independent transverse drive similar to the drive the transverse feed of the threaded cutter, and acts as a movable lunette, which is loaded with a force P _{And a} clamp to the workpiece, equal to the cutting force R _U developed by the threaded cutter m

The work of the proposed device for acupuncture processing of screws is performed in the following sequence.

The blank of screw 1, for example, smooth round rolling, is installed and fixed in a chuck 7 equipped with cams 8, and is pressed by the rear center 9. A chuck 7 is mounted on the spindle 10 of the front planetary headstock 11 of the lathe. The planetary headstock 11 of the lathe is characterized by the planetary movement of the spindle 10, which is installed in the inner 12 and outer 13 eccentric sleeves [2-4]. As can be seen in Fig.2-4, in the body of the grinding headstock 11 are two eccentric sleeves 12 and 13 and the spindle 10, and the rotation of the inner sleeve 12 is provided with planetary movement V _P , and the outer sleeve 13 serves to set the required eccentricity e. Figure 3 shows the layout of the spindle 10 with the workpiece when the eccentricity is maximum and equal to "2E". 4, the axis of the spindle 10 coincides with the axis of the outer sleeve 13. The alignment of the axis of the spindle 10 with the axis of the outer sleeve 13 is used to process conventional shafts with coaxial surfaces.

Pinole 14 with center 9 is located in the tailstock 15 of the machine and has the ability to make planetary motion V _P , similar to the spindle of the front headstock and synchronous with it.

After fixing the screw blank to the back, the needle tool 3 is brought in using the handwheel 16, which is mounted on the screw 17 of the cross support 4 of the machine, creating the force P _{AND of the} needle tool on the workpiece. Next, the handwheel 18, which is mounted on the screw 19, connected with the upper movable plate 20, is brought to the workpiece threaded cutter 2. The threaded cutter 2 is mounted in the tool holder 21, which is installed on the upper movable plate 20. On the dial (not shown) the handwheel 18 sets the depth cutting, as in traditional turning, and includes a longitudinal feed S _PR .

The proposed device allows you to abandon the wide threaded cutters that are used in traditional threading and profiling, reduce power loads and improve accuracy and productivity.

Example. The left screw H41.1016.01.001 of the screw pump EVN5-25-1500 was processed, which had the following dimensions: total length - 1282 mm, length of the screw part - 1208 mm, cross-section diameter of the screw - D = 27 ^-0.05 mm, eccentricity e = 1.65 mm, 2e = 3.3 mm, pitch t = 28 ^{± 0.01} mm, roughness R _a = 3.2 μm; single-helical screw surface, left direction; material - steel 18HGT GOST 4543-74, hardness HB 207-228, weight - 5.8 kg. Billet from round high-quality rolled metal in accordance with GOST 2590-71 with a diameter of 32 mm.

Processing was carried out on a modernized mod screw-cutting lathe. 16K20 with a planetary front spindle headstock (described above) and a planetary tailstock, as well as a transverse caliper on which the front and rear tool holders are mounted, respectively, with a T15K6 GOST 20872-80 threaded cutter and a needle tool with a pile of wire bundle of 1.5 mm diameter, mounted front and back of the workpiece. Cutting speed i.e. workpiece speed V _W = 169.56 m / min (2.83 m / s), n _W = 2000 rpm, planetary speed of the workpiece - V _P = 0.8 m / min (0.0133 m / s), n _P = 77.2 rpm, longitudinal feed S _PR = 0.4 mm / rev. A lubricating coolant (coolant) was supplied to the treatment zones.

The required roughness and accuracy of the helical surface was achieved after T _m = 39.12 min (against T _m ^bases = 76.5 min according to the basic version with the traditional separate rough and semi-finished turning of screws on a lathe model 1K62 equipped with a vortex head on AO Livhydromash).

Thus, to ensure the required quality and dimensional accuracy of processing, the main time was required is almost 2 times less than with separate roughing and semi-turning.

The control was carried out by an indicator bracket with an indicator ICh 10 B cells. 1 GOST 577-68. The cumulative error between any non-adjacent steps was not more than 0.1 mm, the clearance during the control by the straightedge of the protrusions forming in diameter was not more than 0.07 mm, which is permissible according to the technical specifications.

The proposed device for acupuncture processing of screw surfaces of screws expands technological capabilities through the use of planetary high-speed turning, increases tool life due to shock-free processing, improves quality and increases processing productivity, and also reduces the longitudinal deflection of a long non-rigid workpiece by installing an additional support equipped with a needle cutting element, thanks to the installation of the latter, the wear resistance and durability of the machined tops.

Information sources

1. Patent DT 1942050, B23B 5/46, 1970 - prototype.

2. Reference technologist-machine builder. In 2 vols. T.1 / Ed. V.M.Kovana. - 2nd ed., Rev. and add. - M.: GNTIML, 1963. P.361, Fig. 212.

3. Reference technologist-machine builder. In 2 vols. T.2 / Ed. A.G. Kosilova and R.K. Meshcheryakova. - 4th ed., Revised. and add. - M .: Engineering, 1985. P.228, Fig. 34 - prototype.

4. Loskutov V.V. Metal Grinding: A Textbook for Secondary Vocational Schools. - 7th ed., Revised. and add. - M.: Mechanical Engineering, 1985, p. 94-95.

Claims (1)

A device for turning eccentric screws with an eccentricity "e", containing planetary front and rear headstock and cutter, while the front headstock contains external and internal eccentric sleeves, the last of which contains a spindle with a workpiece independently rotating relative to the planetary axis, while the internal eccentric with eccentricity “e”, the sleeve has an individual planetary rotation drive relative to the central axis, and the cutter is mounted in the tool holder on the transverse support and has an independent simulated transverse feed drive, characterized in that it is equipped with a cutting needle tool installed diametrically opposite to the threaded cutter, the cutting needle tool has an independent manual transverse feed drive and is designed to perform the function of a movable rest, loaded with a pressing force to the workpiece, equal to the cutting force developed by a threaded cutter, and the longitudinal movement of the transverse support is kinematically connected with the planetary rotation of the workpiece from the condition of equality Extensions of a support with a cutter and a needle tool for one revolution of the planetary axis to a step of the machined helical surface.

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