CN103418847B - a cutting device - Google Patents

Abstract

A cutting device is characterized in that: it includes a particle knife, a cutting table, a micro-jet nozzle and a hydraulic device; the cutting table and the micro-jet nozzle move in a relatively straight line; the particle knife includes a knife body and a knife head, and the knife The head is convexly arranged on the outer surface of the knife body, the geometric size of the knife head is 10nm ~ 1mm, and a counterweight is arranged in the knife body; the micro-jet nozzle is provided with an injection chamber, and the bottom of the injection chamber is provided with an injection port. The injection opening forms an annular flow, the particle knife is captured by the annular flow, and the outer diameter of the particle knife is adapted to the inner diameter of the annular flow. The advantage of the present invention is that micro-cutting is carried out through water-induced (micro-jet) rotary driving particle knife or fixed "clamping" particle knife. The uneven deformation field generated by the action ensures the quality and work efficiency of micro-cutting, and is a new type of micro-cutting method.

Description

a cutting device

technical field

The invention relates to a cutting device, in particular to a cutting device using a particle knife for processing.

Background technique

With the development of society, the miniaturization of industrial products has become an important feature of high quality, and the key to realize the transformation of product miniaturization lies in the improvement of the processing technology level of micro parts.

Micro-cutting is a fast and low-cost machining method for tiny parts, and it is not limited by the processing materials. The processing quality of parts (such as precision, surface roughness, etc.) )closely related. The performance of the machine tool is mainly related to the spindle, worktable and control system. The diameter of the tool used in micro-cutting is very small. In order to improve the processing efficiency, the spindle speed of the micro-cutting machine tool is very fast.

In order to meet the torque requirements, traditional micro-cutting devices usually use electric spindles and hybrid angular contact bearings. This kind of bearings expands due to frictional heat generation, and the maximum speed generally does not exceed 60,000 rPmin. When the speed is higher, air bearings should be used, but the torque provided by air bearings is small. At present, the maximum speed of air bearing spindles can reach 200,000 rPmin. In order to obtain high cutting speed, the taper of the spindle is consistent with the taper of the high-speed cutting tool holder. The worktable of micro-cutting precision machine tools is generally driven by linear motors. Compared with ordinary drives such as ball screws, linear motor drive systems have no cumulative errors caused by friction and electromagnetic coupling, and no loss of accuracy due to wear. Clearance, and can provide greater acceleration, the accuracy of the linear motor drive system can reach ± 1μm. Micro-cutting precision machine tools have good rigidity and low vibration, and most of them are equipped with various sensors and actuators. They have strict requirements on the control of the surrounding environment, which makes the cost of processing tiny parts higher.

To sum up, the current cutting devices used for micromachining are either too complex in structure, or the manufacturing cost is too high, and the operation has high environmental requirements, which makes assembly and adjustment inconvenient, and cannot meet the requirements of mass production .

Contents of the invention

The technical problem to be solved by the present invention is to provide a cutting device with simple overall structure, low manufacturing cost and easy operation in view of the above-mentioned prior art.

The technical solution adopted by the present invention to solve the above technical problems is: a cutting device, characterized in that: the cutting device includes a particle knife, a cutting workbench, a micro-jet nozzle located above the workbench, and a micro-jet nozzle for the micro-jet nozzle. A hydraulic device for spraying liquid is provided; wherein, the cutting table and the micro-jet nozzle move relatively linearly; the particle knife includes a knife body and a knife head, and the knife head is convexly arranged on the On the outer surface of the knife body, the geometric dimension of the knife head is 10nm～1mm, and a counterweight that can make the knife head on the knife body deflect downward all the time is arranged in the knife body; There is an injection chamber that can be communicated with the liquid outlet pipeline of the hydraulic device, the bottom of the injection chamber is provided with an injection port, and the injection port forms an annular flow, and the particle knife is captured by the annular flow, and, The outer diameter of the particle knife is adapted to the inner diameter of the annular flow.

Preferably, the cutting table can be set to move linearly, and the micro-jet spray head can be set to be fixed.

As another preference, the cutting table can be set to be fixed, and the micro-jet spray head can be set to move linearly.

As yet another preference, the cutting table and the micro-jet nozzle can also be set to move linearly in opposite directions at the same time.

In order to be able to form a stable annular flow, and at the same time facilitate processing and installation, preferably, the micro-jet spray head includes a spray seat and a nozzle, and the spray seat is provided with a through hole penetrating in the axial direction, and the nozzle is connected to the On the bottom of the spray seat, the nozzle is provided with a plurality of small injection holes distributed in a ring in the circumferential direction at a position corresponding to the through hole, and the plurality of small injection holes form the injection port.

As another preferred solution, the cutting device of the present application can also be realized with the following structure, characterized in that: the cutting device includes a particle knife, a cutting workbench, a micro-jet nozzle located above the workbench, and a micro-jet nozzle for the micro-jet The spray head provides a hydraulic device for spraying liquid, wherein the cutting table and the micro-jet spray head move relatively linearly; the particle knife includes a knife body and a knife head, and the knife head is convexly arranged on the On the outer surface of the knife body, the geometric size of the knife head is 10nm to 1mm; the micro-jet spray head is provided with a spray chamber that can communicate with the liquid outlet pipeline of the hydraulic device, and the bottom of the spray chamber An injection port is provided, and the injection port forms an annular flow, and the inner diameter of the annular flow is adapted to the outer diameter of the particle knife; and, the center line of the particle knife is deviated from the center line of the annular flow, The following initial conditions are satisfied between the particle knife and the micro-jet nozzle:

Wherein, in the above formula, k is an action coefficient; r is the distance from the center of gravity of the particle knife to the point of action of the microjet; ρ is the density of the microjet liquid; v ₀ is the microjet in the microjet The velocity at the injection port place of nozzle; g is the acceleration of gravity; h is the height from the bottom of described microjet nozzle to microjet and described particle knife contact point; f is coefficient of static friction; m is the quality of described particle knife; θ is the angle between the point of action of the microjet on the vertical force component of the particle knife to the center of the circle and the vertical outer diameter of the particle knife. Therefore, when the particle knife rotates, the workbench can move linearly relative to the micro-jet nozzle at the same time, so that the cutting process can be realized through the rotation of the particle knife.

Preferably, the cutting table can move linearly, and the micro-jet nozzle is fixed.

As another preference, the cutting table can be fixed, and the micro-jet nozzle can move linearly.

As yet another preference, the cutting table and the micro-jet nozzle can also be set to move linearly in opposite directions at the same time.

As a preference, the micro-jet spray head includes a spray seat and a nozzle, the spray seat is provided with a through hole penetrating in the axial direction, the nozzle is connected to the bottom of the spray seat, and the nozzle corresponds to the through hole in the through hole. The positions of the holes are provided with a plurality of injection holes distributed in a circular shape along the circumferential direction, and the plurality of injection holes form the injection port. The above-mentioned structure of the micro-jet spray head facilitates processing and installation on the one hand, and on the other hand enables the spray liquid coming out of the spray port to form a stable annular flow, ensuring the working stability and processing accuracy of the particle knife.

Compared with the prior art, the advantages of the present invention are: firstly, the cutting edge on the particle cutter head is extremely thin, reaching micron or nanoscale, and can realize nanoscale cutting; secondly, through water-induced (micro-jet) The particle knife is driven by rotation or fixed "clamping" particle knife for micro-cutting. The particle knife does not need to be installed on the machine tool like a traditional tool and is driven by the rotation of the spindle, so that the cutting device does not need a spindle and the overall structure is simpler; in addition, the microfluidic beam Timely take away the heat generated in the cutting process, greatly reducing the uneven deformation field caused by thermal-mechanical coupling, and reducing the size effect, uneven strain, dislocation, etc. of the micro-cutting deformation zone on the shear deformation stress and It is a new type of micro-cutting processing method, which ensures the quality and work efficiency of micro-cutting due to the influence of shear deformation.

Description of drawings

Fig. 1 is a schematic diagram of the structure of a particle knife according to an embodiment of the present invention.

FIG. 2 is a perspective cross-sectional view of the particle knife shown in FIG. 1 .

Fig. 3 is a cutting device using the particle knife shown in Fig. 1 .

Fig. 4 is a force analysis diagram of the particle knife according to the embodiment of the present invention.

Fig. 5 is a calculation diagram of the effective area of the particle knife under the action of the jet according to the embodiment of the present invention.

Fig. 6 is a cross-sectional view of the spray head of the cutting device according to the embodiment of the present invention.

Fig. 7 is a bottom view of the spray head shown in Fig. 6 .

Fig. 8 is a cutting device using another particle knife structure according to the embodiment of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

This embodiment relates to a kind of micro-cutting technology, which is different from ordinary cutting. During micro-cutting, the cutting depth is usually from micron to nano-level, while the grain size of general materials is several microns. The cutting process is to cut the grains one by one, which will inevitably lead to a sharp increase in the cutting stress per unit area, thereby generating a great deal of heat on the unit area of the cutting edge, causing the temperature at the tip to rise. High, in high temperature, high stress working condition.

In order to solve the problems in the above-mentioned micro-cutting process, as shown in Figures 1 to 8, this embodiment proposes a new type of cutting device, which includes a particle knife, a cutting workbench 3, and is located above the workbench 3. The micro-jet nozzle 4 and the hydraulic device that provides the injection liquid for the micro-jet nozzle 4, the micro-jet nozzle 4 is provided with an injection chamber, the top of the injection chamber is provided with a liquid inlet, the liquid inlet is connected to the liquid outlet pipeline of the hydraulic device, and the injection The bottom of the cavity is provided with an injection port, which forms an annular flow, and the outer diameter of the particle knife 1 is adapted to the inner diameter of the annular flow; the micro-jet nozzle 4 includes a spray seat 41 and a nozzle 42, and the spray seat 41 is provided with a Axially through the through hole 411 , the nozzle 42 is connected to the bottom of the spray seat 41 , and the nozzle 42 is provided with a plurality of small injection holes 421 distributed in a circular shape along the circumferential direction at positions corresponding to the through hole.

The cutting device of the present embodiment adopts a particle knife as a tool for cutting, as shown in Figure 1 and Figure 2, the particle knife 1 includes a cutter body 11 and a cutter head 12, the cutter head 12 is in the shape of a convex point, and the cutter body 11 The outer surface of the blade can be provided with one or more cutter heads 12 distributed at intervals; the geometric size of the cutter body 11 is generally set to the millimeter or micron level, as preferably, the size range can be selected between 20 μm and 10 mm, and the cutter head 12 The cutter head 12 is convexly arranged on the outer surface of the cutter body 11 . The geometric size of the cutter head 12 is smaller than that of the cutter body 11 . The knife body of the particle knife in this embodiment can be a regular three-dimensional geometric shape structure, such as spherical or elliptical; the knife body of the particle knife in this embodiment can also be other irregular three-dimensional geometric shapes, as shown in Figure 8. 'That is, an irregular crystal structure.

Among them, the particle knife 1, the micro-jet nozzle 4 and the cutting workbench 3 can have the following movement modes: first, the micro-jet nozzle 4 is fixed, and the particle knife 1 is fixedly placed in the micro-jet nozzle 4, The cutting table 3 can move linearly relative to the micro-jet nozzle 4; in the second type, the cutting table 3 is fixed, the particle knife 1 is fixed and accommodated in the micro-jet nozzle 4, and the micro-jet head 4 can move relative to the cutting table. 3. Linear movement; the third type, the particle knife 1 is fixedly placed in the micro-jet nozzle 4, and the micro-jet nozzle 4 and the cutting table 3 move linearly in the opposite direction at the same time; the fourth type, the cutting table 3 is fixed , the particle knife 1 performs a rotary motion, and the micro-jet nozzle 4 moves linearly; the fifth type, the particle knife 1 performs a rotary motion, the micro-jet nozzle 4 is fixed, and the cutting table 3 can move linearly relative to the micro-jet nozzle 4; Six types, the particle knife 1 performs a rotary motion, and the micro-jet nozzle 4 and the cutting table 3 move linearly in opposite directions at the same time.

When adopting the above-mentioned first, second and third movement modes, a counterweight 2 is arranged in the knife body 11 of the particle knife, and the counterweight 2 can make the knife head 12 on the knife body 11 always face down It is deflected and in contact with the cutting surface. When working, the nozzle of the micro-jet nozzle forms an annular flow with liquid as the medium. The annular flow acts on the surface of the particle knife, generating an inward horizontal component force and a downward force on the surface of the particle knife. The vertical component of the force, the inward horizontal component has a "clamp" effect on the particle knife, and will firmly "clamp" the particle knife located under the micro-jet nozzle like tweezers; the downward vertical component and the counterweight Working together on the particle knife, the knife head 12 is always facing down. When the cutting table and the micro-jet spray head move relative to each other, the cutting of the workpiece can be realized.

When using the fourth, fifth and sixth motion modes above, to realize the rotation of the particle knife in the water potential well, the particle knife must be subjected to a torque. For this reason, the particle knife can be placed On the surface of the material, the symmetrical centerline of the water jet deviates from the center of rotation of the particle knife, and one part of the particle knife is always in contact with the jet water beam, and the other part is not in contact. We call the contact part the action area, and the action area is affected by the pressure of the water beam , the uncontacted area is not affected by the pressure, and the pressure is zero. Due to the existence of the pressure difference, a rotational moment is generated, which makes the particle cutter possible to rotate; When the contact area on both sides of the center of gravity of the particle knife is equal, due to the symmetrical distribution of pressure, no net torque will be generated on the particle knife, and the particle knife will not rotate in the water potential well; when the center of gravity of the particle knife does not overlap with the center line of the jet , that is, the center of gravity of the particle knife deviates from the center line of the micro-jet nozzle, and there is a pressure difference on both sides of the particle knife in the water potential well, and the pressure difference generates a rotational moment on the particle knife, and the particle knife can rotate around its axis. Therefore, the particle knife is rotated by the torque. When the micro-jet nozzle moves horizontally at the same time, the particle knife can rotate while moving, and the workpiece is cut through the relative movement between the worktable and the micro-jet nozzle. .

Specifically, when the particle knife 1 and the cutting table 3 adopt the fourth, fifth and sixth working modes, in order to realize the rotation of the particle knife, the following initial conditions need to be satisfied between the particle knife and the micro-jet nozzle:

Wherein, in the above formula, k is an action coefficient; r is the distance from the center of gravity of the particle knife to the microjet between the point of action of the microjet; ρ is the density of the microjet liquid; v ₀ is the microjet at the microjet nozzle The velocity at the injection port; g is the acceleration of gravity; h is the height from the bottom of the micro-jet nozzle to the contact point between the micro-jet and the particle knife; f is the coefficient of static friction; m is the mass of the particle knife; The angle between the line connecting the point of application of the force to the center of the circle and the outer diameter of the particle knife in the vertical direction.

The above initial conditions are derived through the following mechanical analysis: set the shape of the particle knife as a sphere, and take the particle knife as the research object, and the force analysis is shown in Figure 4;

At rest, the particle knife is in a state of equilibrium, determined by:

$\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}\\ \mathrm{<span\; class="notranslate">\; \&Sigma;</span>}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

have to:

$\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}\\ {\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; mg</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

e=rsinθ (3)

F _f = fF _N (4)

By the momentum moment theorem:

Jα=F _y eF _f rF _x rcosθ (5) If the particle knife rotates, α>0 is required, namely:

F _y eF _f rF _x rcosθ＞0 (6) Substituting formula (2), formula (3) and formula (4) into formula (6), the solution is:

${\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}<span\; class="notranslate">\; ></span>\frac{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}\mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; fmg</span>}}{\mathrm{<span\; class="notranslate">\; sin</span>}\mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 7</span>}<span\; class="notranslate">\; )</span>$

If F _y exists, sinθ-f>0 is required, namely:

f<sinθ (8) When the particle knife is in the initial state of rotation, F _x =0, formula (7) can be simplified as:

${\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}<span\; class="notranslate">\; ></span>\frac{\mathrm{<span\; class="notranslate">\; fmg</span>}}{\mathrm{<span\; class="notranslate">\; sin</span>}\mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 9</span>}<span\; class="notranslate">\; )</span>$

When the jet impacts the particle knife, as shown in Figure 3, the pressure formed on the surface of the particle knife is:

$\mathrm{<span\; class="notranslate">\; P</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; \&rho;g</span>}<span\; class="notranslate">\; (</span>\sqrt{\frac{{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; g</span>}}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; )</span>$

As shown in Figure 5, the shaded part is the maximum action area of the jet on the particle knife, that is, the 1/4 spherical surface, which is shown as a semicircle in the figure. At this time, the action effect is the best.

Assuming that the action area of the jet on the particle knife is S, then:

S=kπr ² (11)

${\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; P.S.</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; k\&pi;</span>}{\mathrm{<span\; class="notranslate">\; r</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; \&rho;g</span>}<span\; class="notranslate">\; (</span>\sqrt{\frac{{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; g</span>}}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 12</span>}<span\; class="notranslate">\; )</span>$

Substitute formula (12) into formula (9):

$\mathrm{<span\; class="notranslate">\; k\&pi;</span>}{\mathrm{<span\; class="notranslate">\; r</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; (</span>\sqrt{\frac{{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; g</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ></span>\frac{\mathrm{<span\; class="notranslate">\; fm</span>}}{\mathrm{<span\; class="notranslate">\; sin</span>}\mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 13</span>}<span\; class="notranslate">\; )</span>$

Equation (13) is the initial condition for the particle knife to rotate and perform cutting.

Among them: π, r, ρ, g, f, m are known, k, v ₀ , h, θ are changing parameters.

The relationship between k and θ is determined as follows.

When the jet impacts the particle knife, the projection of its action area (that is, the mutual contact area) is bow-shaped. According to the textbook of theoretical mechanics, its area S is found to be:

Combine formula (11) and formula (14):

Organized:

k and θ are interrelated variables, which are related to the jet flow, the size of the particles, the relative position between the two, and so on. According to Figure 4, the value range of θ is:

0≤θ<90° (17) Substituting formula (17) into formula (16), the value range of k is:

0<k≤0.5 (18) To sum up, the initial conditions for the particle knife to rotate and cut are:

The meanings of the symbols in the above formulas (1) to (19) are as follows:

F _x is the horizontal resultant force of the liquid on the particle knife;

F _y is the vertical resultant force of the liquid on the particle knife;

F _f is the friction force between the particle knife and the surface to be processed;

F _N is the support force of the particle knife on the surface to be processed;

f is the coefficient of static friction;

r is the particle knife radius;

m is the mass of the particle knife;

g is the acceleration due to gravity;

e is the horizontal distance from the action point of F _y to the center of the particle knife circle;

J is the moment of inertia of the particle knife relative to the center of mass;

P is the pressure of the jet on the surface of the particle knife;

h is the height from the bottom of the nozzle to the point of contact between the jet and the particle knife;

k is the action coefficient;

S is the action area of the jet on the particle knife;

ρ is the density of the jet liquid;

θ is the angle between the F _y action point and the center of the circle and the vertical direction;

α is angular acceleration;

v ₀ is the velocity of the jet at the outlet of the nozzle.

Therefore, as long as the existence of the rotational torque is maintained, the particle knife will continue to rotate, thus realizing the water-induced rotation of the particle knife. On the particle knife, there will be a rotational moment, so that the particle knife will rotate, similar to the effect of wind on the windmill in reality, the "windmill" of the particle knife can rotate under the action of the "wind" generated by the water jet; in addition, The rotation direction of the particle knife depends on its initial position in the water potential well and the shape of the particle knife itself ("initial position" refers to the moment when the water potential well successfully captures the particle knife, and the position of the particle knife in the water potential well).

The water-induced rotation drives the particle knife or the water-induced clamping of the particle knife for micro-cutting. The micro-fluid jets take away the heat generated during the cutting process in a timely manner, greatly reducing the uneven deformation field caused by the thermal-mechanical coupling effect, and reducing the The effect of size effect, uneven strain, dislocation, etc. on the shear deformation stress and shear deformation energy of the micro-cutting deformation zone improves the cutting efficiency and quality.

In the actual working process (the particle knife is rotating), we can choose single crystal silicon as the experimental material, and use the particle knife 1 with a spherical structure as shown in Figure 1 and Figure 2 to conduct micro-cutting and nano-cutting experiments respectively. Since single crystal silicon is a brittle material, according to the principle of fracture mechanics, there is a brittle-plastic transition when processing brittle materials. Due to the cutting of the tool tip, the potential energy of the atoms at the tool tip of the surface to be processed is changed, and the kinetic energy of the silicon atoms increases suddenly, which breaks the arrangement of the atoms and causes a phase transition from the local lattice structure to a disordered state. The sequence state is located under the front of the tool tip. As the cutting direction develops, air pockets are formed at the front. This process is driven by the energy provided by the high strain energy at the tool tip. When the strain energy is converted into kinetic energy, the voids expand and eventually develop into clear cracks. The chemical reaction energy between the air and the crystal increases the kinetic energy of the atoms, the atomic motion intensifies, the distance between the atoms is elongated, the crack expands, the material is peeled off, and chips are formed to complete the cutting process.

Claims (10)

1. a topping machanism, is characterized in that: this topping machanism includes particulate knife, skiver's station, be positioned at microjet shower nozzle above this workbench and provide the hydraulic means of atomizing of liquids for described microjet shower nozzle; Wherein, do relative rectilinear between described skiver's station and described microjet shower nozzle to move; Described particulate knife includes cutter body and cutter head, be arranged on the outer surface of described cutter body described cutter head evagination, the physical dimension of described cutter head is 10nm ~ 1mm, is provided with the balancing weight that the cutter head on this cutter body can be made to deflect all the time in described cutter body down; Described microjet shower nozzle offers the spray chamber that can be connected with the fluid pipeline of described hydraulic means, the bottom of described spray chamber is provided with jet, this jet forms annular stream, described particulate knife by described annular stream catch, further, the internal diameter that flows of the external diameter of described particulate knife and described annular is suitable.

2. topping machanism according to claim 1, is characterized in that: described skiver's station moves linearly, and described microjet shower nozzle maintains static.

3. topping machanism according to claim 1, is characterized in that: described skiver's station maintains static, and described microjet shower nozzle moves linearly.

4. topping machanism according to claim 1, is characterized in that: described skiver's station and microjet shower nozzle move linearly simultaneously in opposite direction.

5. the topping machanism according to claim 1 or 2 or 3 or 4, it is characterized in that: described microjet shower nozzle includes spray seat and nozzle, described spray seat offers the through hole run through vertically, described nozzle is connected to the bottom of described spray seat, described nozzle offers multiple jet apertures circumferentially distributed ringwise in the position of the described through hole of correspondence, and the plurality of jet apertures defines described jet.

6. a topping machanism, it is characterized in that: this topping machanism includes particulate knife, skiver's station, be positioned at microjet shower nozzle above this workbench and provide the hydraulic means of atomizing of liquids for described microjet shower nozzle, wherein, do relative rectilinear between described skiver's station and described microjet shower nozzle to move; Described particulate knife includes cutter body and cutter head, is arranged on the outer surface of described cutter body described cutter head evagination, and the physical dimension of described cutter head is 10nm ~ 1mm; Described microjet shower nozzle offers the spray chamber that can be connected with the fluid pipeline of described hydraulic means, and the bottom of described spray chamber is provided with jet, and this jet forms annular stream, and the external diameter of the internal diameter that described annular flows and described particulate knife is suitable; Further, the center of gravity line of described particulate knife deviates from the center line setting of described annular stream, meets following primary condition between described particulate knife and microjet shower nozzle:

wherein, in above formula, k is function coefficient; R is that the center of gravity of described particulate knife is to the distance of microjet between this particulate knife application point; ρ is the density of microjet liquid; v ₀for microjet is in the speed at the jet place of described microjet shower nozzle; G is acceleration of gravity; H is the height of bottom to microjet and described particulate knife contact point of described microjet shower nozzle; F is confficient of static friction; M is the quality of described particulate knife; θ is that microjet is to the angle between the application point of particulate knife vertical stress component to the line and the vertical direction external diameter of particulate knife in the center of circle.

7. topping machanism according to claim 6, is characterized in that: described skiver's station moves linearly, and described microjet shower nozzle maintains static.

8. topping machanism according to claim 6, is characterized in that: described skiver's station maintains static, and described microjet shower nozzle moves linearly.

9. topping machanism according to claim 6, is characterized in that: described skiver's station and described microjet shower nozzle move linearly simultaneously in opposite direction.

10. the topping machanism according to claim 6 or 7 or 8 or 9, it is characterized in that: described microjet shower nozzle includes spray seat and nozzle, described spray seat offers the through hole run through vertically, described nozzle is connected to the bottom of described spray seat, described nozzle offers multiple jet apertures circumferentially distributed ringwise in the position of the described through hole of correspondence, and the plurality of jet apertures defines described jet.