RU2282529C1 - Oscillating combination type tool - Google Patents

Abstract

FIELD: combination working of metals by friction surface hardening and surface-plastic strike-pulse deforming, possibly finishing surfaces.

SUBSTANCE: combination type tool includes mandrel carrying mounted in it along the same axis device for working by balls and device for friction surface hardening. Tapered washers are mounted in pairs on ends of combination type tool. Washer-gasket is placed between said devices. Device for working by balls includes left and right lids mutually joined along their periphery through elastic shell having seats for balls. Set of spacing washers is arranged between lids. Device for friction surface hardening includes disc made of material with low heat conductivity and having working surface in its periphery. Said disc is mounted by acute angle relative to plane normal to its rotation axis.

EFFECT: enlarged manufacturing possibilities, improved quality, enhanced efficiency of working, increased wear resistance of tool.

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Description

The invention relates to a combined treatment of friction surface hardening of metals and surface-plastic shock-pulse deformation and can be used for finishing, finishing processing of surfaces subject to intense wear, steel and cast iron precision machine parts.

Known combination tool containing a grinding wheel with elements of its attachment to the mandrel and coaxially mounted with it a device for processing metal surfaces with balls [1].

The disadvantages of the known combined tool are: the need for an additional surface hardening operation, for example, quenching by high frequency currents (HFC), cementation and quenching in gas furnaces, etc. This requires additional expensive equipment, tools and time; reduces the productivity, accuracy and quality of the processing process.

The objective of the invention is the expansion of the technological capabilities of the tool by providing periodic, combined and sequential effects on the machined flat and rotating surfaces by friction surface hardening before impulse-impact plastic deformation with axially-shifted working surface, which allows to improve the quality and accuracy, reduce the complexity of processing and tool consumption and increase productivity, as well as noise absorption, reduced ball wear, reduced power losses spines of the drive.

This is achieved using the proposed oscillating combination tool located at an acute angle α to a plane perpendicular to the axis of rotation, and containing a mandrel located in pairs from the ends of the combined tool oblique washers, and a device for treating metal surfaces with balls with its fastening elements on the mandrel, made with left and right covers, connected on the periphery by an elastic shell with nests for balls placed between the said covers by a set of spacer washers, the mmar height of which is not less than the height of the elastic shell, with each nest for balls made in the form of a tube with rolled ends, in which the ball is mounted with free movement, and it is equipped with a device for friction surface hardening mounted on a mandrel coaxially with a device for processing metal surfaces balls, and a spacer washer installed between them, while the device for friction surface hardening is made in the form of a disk made of a material with a low coefficient thermal conductivity and with a working surface on its periphery, installed using oblique washers and washers-spacers at an acute angle α to a plane perpendicular to the axis of rotation, and the acute angle of inclination α is determined by the formula:

arctg (V _beats / D) ≥α≥arctg (V _fr / D),

where In _beats - the height of the elastic shell with balls, mm;

D is the outer diameter of the tool, mm;

α is the acute angle of inclination of the tool to a plane perpendicular to the axis of rotation, deg;

In _FR - the height of the disk device for friction surface hardening.

Figure 1 shows the design of the proposed oscillating combination tool, rotated by a maximum angle α; figure 2 is a section aa in figure 1; figure 3 - more technologically advanced for assembly version of the design of the right cover; figure 4 - design of the proposed combined tool, rotated by a minimum angle α = 0.

The proposed combined tool contains a disk 1 for friction surface hardening with the elements of its fastening on the mandrel 2 and coaxially mounted with it a device 3 for processing metal surfaces with balls.

The fastening elements of the tool are made in the form of oblique washers 4 in the amount of four pieces, two from each end of the combined tool to provide an axially offset cutting layer by installing the disk 1 and device 3 at an angle to a plane perpendicular to the longitudinal axis, with the possibility of smooth adjustment of the oscillation amplitude by changes in the angle of inclination of the disk 1 and the device 3. The spacer washer-gasket 5 and the nut 6 are also fasteners and serve for the reliable installation of the components of the combined tool ment on the mandrel 2.

The device 3 for treating metal surfaces with balls contains a left 7 and a right 8 cover, peripherally connected by an elastic shell 9, in which nests for balls 10 are made, each socket consisting of a tube 11 with rolled ends, in which the ball 10 freely moves.

To ensure the state of "expansion" of the elastic shell 9, which is attached by known methods, for example, vulcanization, to the ends of the covers 7 and 8, between the covers there is a set of spacer washers 12, the total height of which is not less than the height of the elastic shell 9.

To reduce drive power losses, as well as reduce wear of the sockets 11 and balls 10, the axis 13 of each socket 11 is located at an angle β to a straight line 14 connecting the longitudinal axis of the mandrel 2 with the center of the outlet of the socket 11.

The angle β depends on the diameter of the tool, because they select it such that at the moment of contact of the ball 10 with the surface to be treated, the axis 13 of each socket 11 is directed at right angles to it when processing flat surfaces, or along the normal to the tangent when processing surfaces of revolution.

For a more technologically advanced assembly and adjusting the tension of the shell 9, a design option for the right cover is provided (Fig. 3), which is made integral and consisting of a ring 15, a flange 16 connected by screws 17.

The operation of the device 3 with the deforming balls 10 is as follows.

Under the action of centrifugal forces arising from the rotation of the shell 9, the balls 10 protrude above its periphery. By setting the longitudinal feed to the tool and the rotation of the workpiece in the case of processing bodies of revolution, you can process surfaces of any given size. In the case of processing flat surfaces, the combined tool is mounted on the spindle of a surface grinding machine and machined as with traditional flat grinding with the periphery of the wheel.

A device for friction surface hardening, consisting of a disk 1 of a material with a low coefficient of thermal conductivity and with a working surface at its periphery, is installed coaxially with the device 3 with deforming balls. The disk 1 is also located on the mandrel 2 at an acute angle α to the plane perpendicular to the axis of rotation, using oblique washers 4 mounted and arranged in pairs from the ends of the tool, and washers 5 installed between the devices.

Combined tool assembly works as follows.

A workpiece such as a body of revolution is clamped in a chuck, for example, of a grinding or other machine, and a combined tool on the mandrel of the grinding head or in a device with an individual drive. The tool rotates with a peripheral speed V = 65 ... 70 m / s and is pressed with a constant force P = 0.65 ... 1.0 kN to the workpiece that rotates (in the case of processing cylindrical surfaces) with a peripheral speed of 0, 02 ... 0.08 m / s. The longitudinal feed of the tool relative to the workpiece is (0.1 ... 0.2) V _fr , where V _fr - the height of the disk 1 for friction surface hardening, mm

The length of the line of contact of the tool with the workpiece (In _FR ) is 5 ... 8 mm. During friction of the tool and the workpiece in the zone of their contact, the surface of the workpiece being pulsed is heated to a temperature of 800 ... 1000 ° C. A lubricating coolant (coolant) is supplied to the treatment zone, which provides quick cooling of the hardened surface. As a result of hardening, structures of white layers with a thickness of 0.1 ... 0.15 mm with increased microhardness of 7 ... 10 GPa arise on the surface of the workpiece. In the zone of frictional sliding contact, a certain amount of heat (most of it) goes into a rapidly rotating tool. Therefore, titanium alloy or stainless steel having low thermal conductivity (λ = 21.9 ... 25.5 W / m · K) is chosen as the material of the disk. When moving the contact zone in the axial direction due to the inclination of the working disk, the heated working surface of the tool instantly transitions to the cooled surface of the workpiece (Fig. 1). This leads to a cyclical change in temperature on the surface of the hardened workpiece and, accordingly, to an increase in the depth of the hardened layer to 0.15 ... 0.22 mm. By changing the angle of inclination, and therefore by changing the oscillation amplitude A _{fr of the} disk, the depth and microhardness of the hardened layer can be adjusted.

When A _FR <B _{FR, the} increase in the depth of the hardened layer is insignificant, but there is a high probability of overheating of the tool. When the value of A _FR > In _{beats, a} further slight increase in the thickness of the hardened layer leads to an increase in vibration, deterioration in the quality of processing. Therefore, the angle of inclination α is determined by the formula:

arctg (V _beats / D) ≥α≥arctg (V _fr / D),

where B _beats - the height of the elastic shell with balls, mm;

D is the outer diameter of the tool, mm;

α is the acute angle of inclination of the tool to a plane perpendicular to the axis of rotation, deg;

In _FR - the height of the disk for friction surface hardening, mm

Thus, during joint processing with a combined tool, the disk 1, mounted at an angle to the axis of rotation, in contact with the peripheral axially displaced peripheral working layer, hardens the surface layer of the workpiece to a greater depth, and the deforming balls 10 protruding above the periphery of the shell 9 of the device 3 strike on hardened treated surface and reduce the height of microroughnesses. In this case, a final microprofile of regular roughness is obtained with a relatively small number of working balls 10.

The axially displaced working layer of the disk 1 strengthens the work surface by heating it, and the deforming balls ensure the continuity of plastic deformation of the heated surface of the product, which eliminates vibration and vibration of the tool and reduces the roughness of the processed surface.

As the friction disk 1 wears out, it decreases in diameter and it is necessary to restore its original size. To partially adjust the size of the outer diameter in the radial direction and restore the original size, it is rotated in a plane passing through the axis of rotation by a certain angle. This adjustment is possible when replacing the washer gasket 5 with two oblique washers 4 (not shown).

With significant wear of the disk 1 and the device of shock-pulse deformation 3, as well as when finding the optimal processing conditions, use the angle α of the tilt of the tool (figure 4) using mutual rotation of the oblique washers 4 relative to each other.

The proposed combined tool, consisting of a reinforcing disk and a device with deforming balls, is characterized by sound absorption due to the use of an elastic shell, reduced wear of the balls and reduced drive power losses.

The proposed design extends the technological capabilities of the tool by providing periodic, combined and sequential effects on the machined flat and surface of rotation of friction surface hardening before impulse-impact plastic deformation with axially-shifted working surface.

Combined tools can increase wear resistance, improve quality and accuracy, reduce the complexity of processing and tool consumption, as well as increase productivity.

Information sources

1 RF Patent 2228254, MKI B 24 D 5/00, 24 V 39/00, 05/10/2004.

Claims (1)

An oscillating combined tool located at an acute angle α to a plane perpendicular to the axis of rotation and containing a mandrel, slanting washers arranged in pairs from the ends of the combined tool and a device for treating metal surfaces with balls with fastening elements on the mandrel made with left and right covers connected on the periphery an elastic shell with nests for balls placed between the said covers by a set of spacer washers, the total height of which is not less than the height shell, each nest for balls made in the form of a tube with rolled ends, in which the ball is mounted with free movement, characterized in that it is equipped with a device for friction surface hardening mounted on a mandrel coaxially with a device for processing metal surfaces with balls, and a washer placed between them, while the device for frictional surface hardening is made in the form of a disk made of a material with a low coefficient of thermal conductivity and with whose surface at the periphery thereof mounted by means of oblique washers and washer-gasket at an acute angle α to the plane perpendicular to the rotation axis, and the acute angle of inclination α is determined from the following expression: arctg (V _beats / D) ≥α≥arctg (V _fr / D), where In _beats - the height of the elastic shell with balls, mm; D is the outer diameter of the tool, mm; α is the acute angle of inclination of the tool to a plane perpendicular to the axis of rotation, deg; In _FR - the height of the disk device for friction surface hardening.

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