RU2337805C1 - Device for rolling screws with rounded cross profile - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: device has case with three deformation instruments, helical cylindrical spring, holders, two posts, compression springs and columns. The cylindrical spring is made with spacing which is a multiple of the thread of the processed screw and is wrapped around the latter. The holders are mounted inside the helical cylindrical spring at a distance equal to the thread of the processed screw. The two posts have openings and are in a case. One of the above mentioned posts can be moved, while the other is immovable. The columns rest on the compression spring and are put inside the openings in the posts. The deformation instruments are fixed to the holders. The ends of the cylindrical spring are fixed to the columns. The middle deformation instrument is mounted at the opposite extreme deformation instrument relative the processed work piece and is made with provision for radial movement for regulating tightness and rolling force.

EFFECT: more technological capabilities, reduction of roughness parameter of processed surface and increase in hardness of latter.

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Description

The invention relates to mechanical engineering technology, in particular to finishing and hardening processing of workpieces such as screws with a round transverse profile of steels and alloys by surface plastic deformation by a multi-element rolling tool.

Known three-roller device for rolling screws, consisting of a holder with rollers, pivotally connected to the housing, which is mounted on a machine support [1].

A disadvantage of the known device is the limited application, narrow specialization (only for cylindrical surfaces) and low productivity, while to obtain high quality it is necessary to create large working forces, and this requires the use of rollers with a large radius of the profile, which negatively affects the overall dimensions and not always feasible.

A known method and device that implements it for rolling screws, providing a message to the workpiece rotational motion, and a deforming tool containing a housing and a holder with deforming elements, movably connected to the housing, the message is a longitudinal feed movement, while rolling is carried out by many deforming elements, except Moreover, the tool is equipped with two disks with central holes, one of which is rigidly connected to the body, and the other disk is rigidly attached to the end of the disc using spacer sleeves and screws, while between the discs a holder that holds deforming elements with rings that are inserted into the end grooves of the holder and axially limit the deforming elements freely located in the trough are freely installed using three extensions in the form of tension springs the holes of the holder, while to prevent rotation of the holder, it is equipped with a handle located on the periphery, which is supported by a roller with an axis fixed between the disks, in addition, the said stretch marks -pruzhiny fixed to the spacers [2, 3].

A disadvantage of the known method and device that implements it is the limited use due to narrow specialization - only for screws of the same name, when changing the processing object, another device for rolling in is necessary, as well as the inability to regulate the interference of deforming elements and regulating the rolling force, therefore, the workpiece is large a batch of parts processed in a previous operation with a maximum outer diameter within the tolerance will be run in with a maximum interference, therefore, with max minimum rolling force, and a workpiece with a minimum outer diameter - with a minimum rolling force. These blanks will have different roughness, degree of hardening and depth of the hardened layer, i.e. the process is unstable, which is undesirable.

The objective of the invention is the expansion of technological capabilities, which consists in reducing the error of previous processing and improving accuracy by unloading the machine components from the one-sided application of the rolling force when processing screws, in reducing the roughness parameter of the treated surface and increasing its hardness to a considerable depth due to the smoothing effect of several deforming tools, increasing productivity by increasing the contact spot of deforming tools with a machined surface and the possibility of applying large feeds and regulating working forces, as well as treating the screw surfaces of large-range screws and being universal.

The problem is solved using the proposed device for rolling screws with a round transverse profile, comprising a housing with three deforming tools, and it is equipped with a coil spring, the step of which is a multiple of the step of the machined screw, having at least one turn and configured to cover the machined screw for providing radial feed to deforming tools, holders installed inside the coil spring at a distance equal to the pitch screw, two racks with holes located in the housing, one of which is movable, and the other is stationary, compression springs and columns supported by compression springs and located in the holes of the racks, while the said deforming tools are fixed in holders, the ends of the cylindrical screw the springs are fixed on the columns, the middle deforming tool is installed opposite the extreme deforming tools relative to the workpiece and is made with the possibility of radial movement Plenum for adjusting the interference fit and break-in force.

Features of the device are illustrated by drawings.

In Fig.1 shows a diagram of rolling a screw with a round transverse profile of the proposed device, a partial longitudinal section; figure 2 is a cross section aa in figure 1; figure 3 is a section bB in figure 2.

The proposed device is intended for processing by surface plastic deformation of the outer surfaces of rotation of the workpieces of the type of screws mainly with a large pitch and a round transverse profile, for example, screws of screw oil pumps.

Processing is performed on turning, rotary machines with a message about the rotational movement of the workpiece - V _s , and for a device with deforming tools - longitudinal feed movement S _ave .

Deforming tools, such as balls 1, are fixed in the holders 2 and installed inside a coil spring 3.

The rolling treatment is carried out by several (for example, three, as shown in FIG. 1) deforming tools 1 fixed in the holders 2.

The holders 2 are installed from each other at a distance of step t of the machined screw 4 inside the coil spring 3. The spacing of the spring 3 is a multiple of the pitch of the machined screw 4 and its minimum value is equal to two steps - 2t of the machined screw (see Fig. 1). A spring 3 with a length of at least one turn in order to ensure a radial feed S _{P to the} deforming tools 1 covers the workpiece 4. The ends of the spring 3 are rigidly fixed to the columns 5, which are movably mounted on a sliding fit in the holes of the uprights 6. The columns 5 are supported by compression springs 7, the last also located in the holes of the uprights 6. The extension of the columns 5 from the uprights 6 under the action of the springs 7 in the inoperative state of the tool is limited by the union nuts 8.

To tune to a specific step equal to 2t, the springs 3 of the strut 6 are interconnected by a rod 9, the nuts 10 are screwed on their threaded ends, while one strut is mounted on the housing 11 motionless, the other is movable, with the possibility of adjusting the distance between them.

The middle deforming tool 1 is installed inside the spring 3 opposite to the extreme deforming tools and is equally removed at a distance t of the step of the workpiece 4 in the longitudinal direction relative to the extreme deforming tools.

The middle deforming tool 1, in contrast to the extreme deforming tools, which are fixed on the spring 3 rigidly, has the ability to radially move in order to regulate the interference fit and rolling force with the help of the clamp 12 and the threaded holder 2 (see Fig. 3).

The assembly of the device is carried out in the following sequence.

On the case 11, prepared for installation, for example, on the transverse support of the lathe, install and rigidly fasten the fixed stand 6. The movable stand 6 is installed on the dovetail on the case 11. Both stands 6 are connected by a rod 9 with a distance of 2t between the axes of the holes for the columns and fix with nuts 10. In the holes for the columns of the uprights 6, the springs 7 and the columns 5 are inserted, pre-mounted on the power spring 3, on which holders 2 with deforming tools 1 are also installed.

Columns 5 are fixed from falling out of the rack openings with nuts 8.

The general assembly of the device ends by installing the middle deforming tool 1 by fixing the clamp 12 and screwing the threaded holder 2 with the deforming tool 1 pre-fixed on it.

At the end of the assembly, the deforming tool is adjusted and adjusted to the required size by installing it on a control sample of the screw and contacting the deforming tools with the surface of the screw with the necessary force by unscrewing the threaded holder 2 from the clamp 12. A certain position of the holder is fixed by known methods, for example, a lock nut . It is also necessary to adjust the position of the deforming tools in the longitudinal direction, carried out by moving the movable stand by tightening or loosening the nuts 10 on the rod 9.

Work with the proposed device is carried out in the following sequence.

When finishing with surface plastic deformation - rolling in a screw with a circular cross-section having a profile and dimensions D, D ₁ , t, е (Fig. 1 shows screw H41.1103.01.027 with dimensions D = 98 mm, D ₁ = 70 mm , t = 180 ± 0.05 mm, e = 14 ± 0.1 and a total length of 1655 mm) with a deforming tool, the screw blank, which has undergone preliminary, for example, commodity processing, is fixed in the cartridge 13 of the spindle 14 of the headstock 15, the device is brought in and the free end of the screw blank into the hole of the device and tighten the center 16 of the tailstock 17. The processed zag ovki reported screw rotational movement V _s. The speed of rotation of the workpiece is set depending on the required performance, design features of the workpiece and equipment. Typically, the speed is V ₃ = 30 ... 150 m / min. The deforming tool is informed of a longitudinal feed S _PR in one direction of not more than 0.1 ... 3.0 mm / rev. The optimal supply of S ^O _PR is determined by the formula: S ^O _PR = k S, where k is the number of deforming tools; S - feed to one deforming tool, accepted for balls no more than 0.01 ... 0.05 mm / rev.

When switching to processing of another screw size, it is enough to replace the spring 3 complete with holders 2 and deforming tools 1.

Example. A screw N41.1103.01.027 with dimensions D = 98 mm, D ₁ = 70 mm, t = 180 ± 0.05 mm, e = 14 ± 0.1 and a total length of 1655 mm, roughness R _a = 0.4 was machined by rolling microns; one-way screw surface, right direction; material-steel 12X18H9T GOST 5632-72, hardness HB 207 ... 228, weight - 50 kg. Preliminary processing by turning and finishing processing by rolling was carried out on a mod screw-cutting lathe. 1M63BF101, the peripheral speed of the workpiece - V _s = 88 m / min (1.47 m / s), n _s = 400 r / min, the longitudinal feed S _pr ^{about was} determined by the formula S _pr ^about = k S mm / rev and took S _pr ^about = 3 · 0.3 = 0.9 mm / rev, where k = 3 is the number of rollers in the tool, the diameter of the rollers is 14.88 mm. The breaking-in force was about ≈ 1700 N, the depth of the riveted layer was in the range 0.15 ... 0.20 mm; the size by which the size has changed after running-in - 0.01 ... 0.02 mm; Sulfofresol (5% emulsion) served as a lubricating and cooling fluid during the run-in.

The required roughness and accuracy of the helical surface was achieved after T _m = 4.4 min (against T _m ^bases 16.8 min according to the basic version with traditional grinding using a grinding head, followed by polishing with an abrasive tape LVT 2200 × 55 E4, 5-8 -10 GOST 12439-79 on a 1K62 lathe at Livhydromash JSC). 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 when controlling the straightedge of the protrusions forming in diameter was not more than 0.07 mm, which is permissible according to the technical specifications.

The advantages of the proposed device with a floating multi-element tool for rolling screws with a round profile of the end section are:

- the ability to run in screws with an increase in machining accuracy (by 10 ... 20%) due to the design (all inaccuracy is reduced to inaccuracy of one element - the spring);

- allows running in at maximum feeds in comparison with single-tool devices;

- reduction of the error of the previous processing;

- ensuring a constant contact force of deforming tools with the work surface;

- the multi-element tool allows for multi-pass processing, due to which a higher quality of processing is achieved;

- allows you to unload the machine components from a one-sided application of force and process a large range of screws;

- the formation of a certain macro- and microgeometric shape of the treated surface, a decrease in the roughness parameter — smoothing of the surface, a change in the structure of the material — surface hardening and the creation of a certain stress state — all this favorably affects the wear resistance.

The proposed device for rolling screws with a circular cross-section is easy to implement, and the deforming tool is not complicated in design and reliable in operation. The structural layer obtained on the surface of the workpiece has increased hardness and, accordingly, wear resistance and resistance to fatigue failure.

Using the proposed device can improve processing productivity by 2 ... 2.5 times and ensure high accuracy.

Information sources

1. Reference technologist - machine builder. In 2 T.T.2 / Ed. A.G. Kosilova and R.K. Meshcheryakova. - 4th ed., Revised. and add. - M .: Mechanical Engineering, 1985. P.387, Fig. 6.

2. RF patent No. 2 268 134, IPC V24V 39/00. Floating device for rolling in non-rigid screws. Stepanov Yu.S., Kirichek A.V., Samoilov N.N., Afanasyev B.I., Katunin A.A., Fomin D.S. Application 2004128667/02, 09/27/2004; 01/20/2006. Bull. No. 02.

3. RF patent No. 2268135, IPC V24V 39/00. The method of running in non-rigid screws. Stepanov Yu.S., Kirichek A.V., Samoilov N.P., Afanasyev B.I., Katunin A.A., Fomin D.S. Application 2004128668/02, 09/27/2004; 01/20/2006. Bull. No. 02 is a prototype.

Claims (1)

A device for rolling round screws with a round transverse profile, comprising a housing with three deforming tools, characterized in that it is provided with a helical coil spring, the step of which is a multiple of the step of the machined screw, having at least one turn and made with the possibility of covering the machined screw to ensure radial feed deforming tools, holders installed inside the coil spring at a distance equal to the pitch of the screw being machined, with two uprights In the case, located in the housing, one of which is movable and the other is stationary, compression springs and columns supported on compression springs and located in the holes of the uprights, the aforementioned deforming tools are fixed in holders, the ends of the coil spring are fixed on the columns, middle the deforming tool is installed opposite the extreme deforming tools relative to the workpiece and is made with the possibility of radial movement to adjust the interference and effort running in.

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