WO2006078189A1

WO2006078189A1 - Vibration cutting method and a vibration cutter

Info

Publication number: WO2006078189A1
Application number: PCT/RU2005/000324
Authority: WO
Inventors: Sergey Nikolaevich Tikhonov; Eduard Mikhailovich Gots
Original assignee: Sergey Nikolaevich Tikhonov; Eduard Mikhailovich Gots
Priority date: 2005-01-20
Filing date: 2005-06-09
Publication date: 2006-07-27

Abstract

The invention relates to mechanical engineering and to processing hard-to-machine steels, alloys, tough non-ferrous metals and composite materials. The inventive method consists in rotating a machining workpiece, in translating a cutter and in carrying out the oscillatingly adjustable displacement of the cutter cutting point under action of cutting resistance forces acting on an oscillating circuit which consists of the movable cutting point of the cutter, resilient elements and the fixed part of the cutter. In order to increase the process performance and the tool resistance, said invention provides for the use a cutter comprising an additional resiliently damping oscillating circuit operating on a plane which is perpendicular to the main oscillating circuit in such a way that an additional damping bridging is produced in the front area of the cutter cutting point, wherein said resilient element of the main circuit is used for damping the stem of the cutter part with respect to the fixed part thereof.

Description

Vibratory cutting method and vibration cutter

The invention relates to the field of engineering, in particular to the processing by vibration cutting of materials, mainly hard to work steels, alloys, viscous non-ferrous metals, composite and other materials.

The inventive method and device for its implementation provide crushing chips during the processing of any materials while ensuring high productivity and high quality of the processed surface, and without the use of additional sources and devices for creating vibration.

Vibratory cutting of metals provides reliable crushing of chips during processing of any material. This effect is widely used in technology.

However, to implement the known methods of vibrational cutting, additional energy sources are usually used to drive devices that provide oscillatory movement of the cutting tool: mechanical, electromechanical, hydraulic, magnetostrictive, etc.

Known "Method and device for the formation of crushed chips during processing of a rotating part" (US patent N ° 5113728, application. 10/11/1990, publ. 05/19/1992), in accordance with which the thickness of the chip periodically varies from maximum to zero. Such a periodic change in thickness is achieved due to the impact of the vibrating in a certain way, depending on the angular position of the rotating workpiece, the cutting tool. In accordance with the invention, the vibration of the tool can be provided by various devices. In a specific embodiment, an electromechanical drive is used.

It is known "Device for vibrating cutting" (RF patent X ° 2212309, declared. 08.22.2001, publ. 09/20/2003), in which the necessary nature of the movement of the cutting tool is provided through the use of an additional drive and a swing mechanism in the form of an eccentric shaft paired with eccentric sleeve.

In the invention, “Method for metal cutting and a device for its performance” (RF patent Ni.2030255, application. 17.04.1992, publ. 10.03.1995), the magnetostriction method was used to excite elastic vibrations. The disadvantage of all of the above inventions is the need for an additional energy source and a device for bringing the tool into oscillatory motion. The presence of a rigid kinematic connection between the cutter and the oscillation generator leads to a decrease in cutting speed, tool life and accuracy of the workpiece.

In the international application “Method and Vibratory Cutter for Processing Hard-Working Steels, Alloys, Viscous Non-Ferrous Metals and Composite Materials” (WO 03/086688 Al, decl. without using an additional energy source. Bringing the cutting tool into constant oscillatory motion is ensured by the action of the resistance forces to the cutting and the elastic elements included in the oscillatory circuit of the vibrating cutter. This invention is selected as a prototype. The prototype method provides the following steps:

- rotation of the workpiece relative to the axis of rotation;

- translational movement of the cutter when feeding;

- bringing the movable cutting part of the cutter to strictly defined positions depending on the angular position of the rotating part along the entire path of its translational movement when feeding, that is, ensuring the oscillatory movement of the moving part of the cutter.

At the same time, under the action of cutting forces on an oscillating circuit that closes the moving oscillating cutting part of the cutter through a set of elastic elements on the fixed part (cutter body), the path of the tip of the cutter has a sinusoidal shape with different amplitude A of vibrations and height h of microroughnesses. the possibility of adjustment provided by elastic elements of various stiffness included in the oscillatory circuit of the cutter.

The prototype vibrating cutter comprises a housing (stationary working part), a housing cover, a movable (oscillating) part with one or more removable cutting plates, and a set of elastic elements connecting the movable part of the cutter with the housing and cover with the formation of an oscillating circuit. In this case, the movable part of the cutter installed with the possibility of rotation under the action of constituent cutting forces that occur during processing on an axis fixed between the body and the cover.

However, the method and cutter selected as a prototype do not provide the necessary processing accuracy. Under the influence of considerable efforts, in particular as a result of the action of negative (directed against the direction of movement of the cutter) pulses, spontaneous

"Squeezing" the cutter from the axis of the workpiece. At very high loads, the moving part of the cutter can even jam, and under such conditions the cutter will not work as a vibrating one, but as an ordinary one.

The objective of the present invention is to eliminate this drawback and create a method of vibration cutting and a vibration cutter without the use of additional energy sources, providing high precision processing with significant performance, as well as increased tool life.

This problem is solved due to the fact that in the method of vibrational cutting, which includes rotation of the workpiece, the translational movement of the cutter and oscillatory sinusoidal adjustable movement of the cutting part of the cutter under the action of resistance to cutting, acting on the main oscillating circuit, which includes a movable (rotary) cutting part the cutter, the elastic elements and the stationary part of the cutter, according to the invention, creates an additional elastic-damping oscillatory circuit operating in the plane, which is perpendicular to the main oscillating contour of the plane, when the contours interact, an additional damping closure is provided in the front zone of the movable cutting part of the cutter to the corresponding stationary part of the cutter, while the elastic elements of the main contour also perform the function of damping the shank of the moving part of the cutter relative to the body.

In the method of vibratory cutting with longitudinal turning, the vibrational contours provide the creation of angular vibrations, when cutting and cutting - tangential vibrations, and when boring holes - torsional vibrations.

The above problem is also solved due to the fact that in the vibrating cutter containing the housing and mounted with the possibility of rotation relative to it, the movable working part of the cutter, connected by an oscillating circuit comprising a set of elastic elements, according to the invention, between the movable (rotary) working part of the cutter and the body in the front zone there is an additional elastic-damping element included in the additional oscillating circuit, while the elastic element of the main oscillating circuit placed in the shank of the movable part of the cutter is made damping, and the action planes of the contours are mutually perpendicular.

The vibrating cutter is also characterized in that the elastic-damping elements cover the entire lateral surface of the moving part of the cutter along the perimeter or part thereof and are made by continuous casting.

The vibrating cutter is characterized in that the elastic damping elements cover the entire inner surface of the housing in contact with the side surface of the movable part of the cutter, or its part and are made by continuous casting.

Using the main oscillating circuit, as in the prototype, provides the creation of oscillatory motion of the cutting part of the cutter through the use of resistance to cutting. The parameters of the oscillatory process are also regulated by changing the stiffness of the elastic elements of the main oscillating circuit.

The introduction of an additional elastic-damping oscillatory circuit closed to the housing, the action of which is synchronized with the action of the main oscillatory circuit, ensures the preservation of the complex, adjustable nature of the sinusoidal movement of the cutting part of the tool depending on the angular position of the workpiece, while maintaining constant movable engagement between the tool and the part. Excessive negative impulses arising at high loads, leading in the prototype to “squeeze” the cutting part from the workpiece, are fully compensated (damped) by an additional oscillatory circuit, which allows for high accuracy of the diametrical dimensions of the workpiece. The same elastic damping oscillatory circuit provides reliable prevention of jamming of the moving part of the cutter relative to the housing. The execution of the elastic element the main oscillating circuit located in the shank of the movable part of the cutter or adjacent to this tail part, elastic-damping increases the reliability and accuracy of the work.

In addition, the use of sinusoidal movements of the cutting part of the cutter created by two oscillatory circuits of a given complex nature ensures a reduction in the loads on the cutter and, as a result, an increase in its durability.

The invention is illustrated by drawings:

- Fig.l is a schematic representation of a method of vibration cutting with angular vibrations of the cutter during the turning operation;

- figure 2 - the trajectory of the tip of the cutter in the XOY plane;

- Fig.Z - a through vibration cutter during the turning operation;

- figure 4 - vibration cutter during the operation of cutting;

- figure 5 - vibration cutter during the operation of the bore. The proposed method of vibrational cutting of mainly difficult-to-work steels, alloys, viscous non-ferrous metals, composite and other materials includes the following actions: rotation of the workpiece, translational movement of the cutter in the feed direction, constant oscillatory sinusoidal movement of the moving cutting part of the cutter relative to the axis of the main oscillating circuit. The operation of the oscillatory circuit is based on the interaction of a rotating part, the moving part of the cutter, the stationary body of the cutter and the elastic elements connecting the moving and fixed parts of the cutter. In this case, the oscillatory circuit plays the role of a pendulum, driven by the forces of resistance to cutting and providing “swing” of the cutting part of the cutter.

In addition, during the implementation of the method, the absorption (damping) of the forces tending to “squeeze” the tip of the cutter from the surface to be machined, that is, increase the distance from the tip of the cutter to the axis of the rotated part by an additional elastic-damping oscillatory circuit, takes place. An additional elastic-damping element of this contour closes the movable part of the cutter on the stationary body of the cutter in a zone close to the cutting zone. The damping effect is enhanced by imparting damping functions to the elastic element of the main oscillating circuit. As a result of this damping provided permanent engagement of the cutting part of the cutter with the workpiece surface.

In this case, the action planes of the oscillatory circuits are at right angles to each other. The parameters of the sinusoidal oscillatory motion (amplitude A, microroughness height h) can be controlled, for example, by changing the stiffness of the elastic elements.

The method is as follows. The workpiece 1 (FIG. 1) is mounted in the chuck of the lathe 2. The tool body 3 is fixed in the tool holder of the lathe.

The workpiece 1 is driven into rotation with an angular velocity co.

The required cutting depth t and the working feed S are set. The movable cutting part 4 of the vibratory cutter is brought into contact with part 1. The thickness of the cut is formed as a result of two movements: rotational movement of the workpiece with an angular velocity ω and feed motion S. During cutting, resistance forces arise cutting. They act on the main oscillating circuit. The cutting part 4 of the vibration cutter in relation to the workpiece 1 moves in the feed direction S and angular oscillations in the XOY plane. In this case, the oscillatory circuit performs the function of a pendulum with the axis of oscillation K.

The angular velocity of the workpiece 1 ω (τ) and the linear velocity of the cutting part 4 of the cutter, equal to the feed rate S, are variables. The law of oscillatory movement of the cutter is harmonic:

J ₂ = A ₂ sin τ, where

J is the angle of rotation of the cutter relative to the perpendicular restored from the axis of vibration K to the axis of the workpiece 1, respectively, for the first and second turns of the part 1;

A is the angular amplitude of the oscillations; τ is the phase angle;

T ₀ - phase angle, taking into account not an integer number of oscillations per revolution. In FIG. 2, the dashed line shows the trace of the tip of the cutter under the action of a power pulse, positive (coinciding with the direction of supply of the tool) at the first revolution and negative (direction of the force pulse is opposite to the direction of supply) at the second revolution. As can be seen from the figure, at the first revolution under the influence of a positive impulse, the increment of the cutting feed equal to S _p / 2 is added to the main feed per revolution S _p . After a period of time equal to the time of one revolution of the part t _Ob , the cutter is given a negative impulse, as a result of which the cutter moves in the opposite direction by ΔS / 2, which leads to interruption of the discharge chips. At the next turn of the part, the cutter will overcome the load, which is less by the value of S _p / 2, than in the case of the action of only positive or only negative impulses. This provides a reduction in the load on the cutter and, consequently, an increase in its resistance.

This is how the main oscillating circuit works. But when significant loads occur due to the action of a negative pulse, “cutting” of cutter 4 from the workpiece 1 can occur. To eliminate this drawback, a second additional elastically damping oscillatory circuit is provided, which operates in a plane perpendicular to the action plane of the main oscillatory circuit. The purpose of this additional circuit is the absorption of excess energy. In this case, a short circuit occurs on the cutter body in two zones: on the elastic elements of the main oscillating circuit and on the additional elastic-damping element in the front zone of the moving part 4 of the cutter. To increase the effect, the elastic element of the main oscillating circuit, located in the rear part of the movable part 4 of the cutter (connected to or adjacent to it), is made elastically damping. Moreover, the elastic modulus of the additional circuit is much lower than the elastic modulus of the main oscillating circuit.

In this example, longitudinal turning is considered. Similarly, operations can be performed segments (slotting), boring (see figure 4 and 5). In all cases, additional elastic-damping elements are positioned in such a way as to prevent the “cutting” of the cutting tool from the work surface. The vibrating cutter (Fig. 3) comprises a housing 3 and a movable cutting part 4 mounted with the possibility of rotation relative to it, interconnected by two oscillatory circuits.

The main oscillating circuit includes a movable cutting part 4 of the cutter with one or more removable cutting plates 5, the fixed part of the cutter - body 3, a set of elastic elements. Elastic elements can be metal, rubber-metal and polymer. The set of elastic elements includes an element 6 located between the shank of the movable working part 4 and the corresponding part of the cutter body 3. This element 6 has damping properties. The axis 7 of the main oscillating circuit is fixedly mounted in the housing 3. The movable part 4 of the cutter is mounted on the axis 7. The oscillating circuit may also include additional bearing units 8.

The additional elastic-damping oscillatory circuit includes an elastic-damping element 9 located in the front zone of the cutter between the movable rotary working part 4 and the housing 3. In addition, the elastic-damping element 6 of the main circuit is involved in the operation of the additional circuit.

Elastic-damping elements can be made of elastic polyurethane, polyurethane rubbers and other polymers. To impart damping properties, element 6 may be provided with a shell of the specified material.

Elastic-damping elements 6 and 9 can be made in the form of a coating covering the entire lateral surface of the moving part of the cutter along the perimeter, and can cover only part of this surface. This form of execution is achieved by continuous casting. Thus, the entire contact surface between the body and the side walls of the movable part of the cutter or part of this surface is covered with a layer of elastic damping material.

Similarly, a coating of resiliently damping material may be poured onto the inner surface of the tool body in contact with the moving part of the tool, or on its part. The form of execution of elastic and elasto-damping elements, their rigidity, location is determined depending on the material being processed, dimensions and other characteristics of the workpiece 1.

Thus, the inventive method of vibration cutting and vibration cutter provide: the ability to process any materials, including hard-working steels, alloys, viscous non-ferrous metals, composite and other materials;

- reliable chip crushing; - the accuracy of the geometric dimensions of the machined part;

- high tool life;

- high productivity of the processing process.

It does not require the use of additional energy sources, special devices to ensure the vibrational movement of the tool. The above examples are not exhaustive and it is possible to use various configurations and modifications of the invention without deviating from its essence, formulated in the proposed claims and defined by them.

Claims

FORMULA

1. The method of vibrational cutting, involving rotation of the workpiece, translational movement of the cutter and oscillatory sinusoidal adjustable movement of the cutting part of the cutter under the action of resistance to cutting, acting on the oscillating circuit, which includes a moving cutting part of the cutter, elastic elements and a fixed part of the cutter, characterized in that creates an additional elastic-damping oscillatory circuit operating in a plane perpendicular to the main oscillating circuit In case of interaction between the contours, an additional damping closure is provided in the front zone of the movable cutting part of the cutter to the corresponding stationary part of the cutter, while a part of the elastic elements of the main contour also performs the function of damping the shank of the moving part of the cutter relative to the body.

2. The method according to p. 1, characterized in that during longitudinal turning, the vibrational contours provide the creation of angular vibrations, when cutting and cutting - tangential vibrations, and when boring holes - torsional vibrations.

3. A vibrating cutter comprising a housing and a movable working part of the cutter mounted rotatably relative to it, connected by an oscillating circuit comprising a set of elastic elements, characterized in that between the movable working part of the cutter and the housing in the front zone there is an additional elastic-damping element included in the additional oscillatory circuit, while the elastic element of the main oscillating circuit, located in the shank of the movable part of the cutter is made damping, and the action plane I contours are mutually perpendicular.

4. The vibrating cutter according to claim 3, characterized in that the elastic damping elements cover the entire lateral surface of the moving part of the cutter around the perimeter and are made by continuous casting.

5. The vibrating cutter according to claim 3, characterized in that the elastic damping elements cover part of the side surface of the moving part of the cutter and are made by continuous casting.

6. The vibration cutter according to claim 3, characterized in that the elastic damping elements cover the entire inner surface of the housing in contact with the side surface of the moving part of the cutter and are made by continuous casting.

7. The vibration cutter according to claim 3, characterized in that the elastic damping elements cover part of the inner surface of the housing in contact with the side surface of the moving part of the cutter, and are made by continuous casting