CN1050837A - Stepped middle-positioned ultrasonic vibration cutting device - Google Patents

Abstract

The invention relates to an ultrasonic vibration cutting device. The bending vibration cutter bar is characterized in that the traditional bending vibration cutter bar with the equal section is designed into a step symmetry type bending vibration cutter bar, the ratio of the sectional areas of a thin section and a thick section of the bending vibration cutter bar is less than or equal to 1/4, and the bending vibration cutter bar is clamped and fixed near the sudden change of the sections of the thick section and the thin section. The step bending vibration cutter bar has the function of two-stage amplitude variation, so that the manufacturing, tuning, using, cutter regrinding and the like of a vibration system are convenient, and particularly, the cutter is easier to resonate due to the fact that the cutter is remounted after regrinding.

Description

Ladder middle ultrasonic vibration cutting device

The present invention is the ultrasonic vibration cutting device that uses in a kind of machining.

UVC is the edge new technology that ultrasonic wave physics combines with cutting principle, and it is difficult to grinding and during to the higher part of surface quality and required precision, has excellent technological effect in that cutting is various.Researchs in this respect such as Japan, the Soviet Union, the U.S., China are more.At present, the subject matter that exists during at home and abroad UVC is used is to lack a kind of ultrasonic vibration cutting device more stable, easy to use.

Ultrasonic vibration cutting device is made up of supersonic generator, transducer, compressional vibration luffing bar and flexural vibrations knife bar parts such as (cutters).Send the high-frequency electrical signal by supersonic generator and be converted into high-frequency mechanical vibration through transducer, by compressional vibration luffing bar the amplitude of vibration is amplified and be applied on the flexural vibrations knife bar, the flexural vibrations knife bar is with the form resonance of shear wave.

Both at home and abroad in existing this class ultrasonic vibration cutting device, all adopt prismatic flexural vibrations knife bar or point of a knife to be positioned near the neutral line and press the similar knife bar of uiform section flexural vibrations knife bar design, making important luffing function concentrate is born by compressional vibration luffing bar, promptly only rely on the one-level luffing effect of compressional vibration luffing bar, make every effort at the bigger amplitude of point of a knife place acquisition.But this vibrational system can't solve following contradiction: the 1) contradiction of the small and exquisite property of the acquisition of high amplitude and system architecture.For the ease of practical application, always wish that acoustic heads (being made up of transducer and compressional vibration luffing bar) volume is the smaller the better, but the way that obtains large amplitude usually is to adopt the cascade of multistage combined compressional vibration luffing bar, thereby causes structure huge.2) contradiction of the job stability of compressional vibration luffing bar and luffing ratio.Though as taper compressional vibration luffing bar job stability and processing technology are preferably arranged, in the UVC system development, often do not adopt than little because of luffing.3) contradiction of vibration of the high amplitude of flexural vibrations knife bar and knife bar clamping.The flexural vibrations knife bar is because cutting force the time is born in cutting, must be near node clamping, the knife bar vibration amplitude is big more, clamping is difficult more.In addition, knife bar length changes after cutter is refaced, and is difficult for resonance again during clamping.

In a word, conventional apparatus often is not suitable for UVC for the acoustic heads that uses at the point of a knife place bigger amplitude of acquisition, and device in use generally needs to adjust repeatedly ability resonance, after cutter is refaced, flexural vibrations knife bar length changes, and is difficult for resonance.

Purpose of the present invention is exactly in order to solve the existing existing above problem of ultrasonic vibration cutting device, designed a kind of ultrasonic vibration cutting device of realizing the secondary luffing.

Ultrasonic vibration cutting device of the present invention mainly is by cooling jacket (1), ultrasonic transducer (2), compressional vibration luffing bar (3), flexural vibrations knife bar (4), knife bar anchor clamps compositions such as (5), it is characterized in that flexural vibrations knife bar (4) is thick in the middle of being, two ends are thin, its aspect ratio equals 1/2 or less than 1/2, width is than equaling 1/2 or less than 1/2 symmetrical expression stepped stem (i.e. the ratio of (7) section and (4) section), all be provided with blade at the bar two ends, its thin segment is less than or equal to 1/4 with the ratio of thick section sectional area, and in two abrupt changes of cross-section (8), (9) locate clamping, the knife bar of this structure has the function of conversion flexural vibrations amplitude (being the secondary luffing) and makes exciting point (being the tie point of compressional vibration luffing bar and flexural vibrations knife bar) position characteristic of accurate, and a knife bar is equivalent to two cutters.

According to theoretical and experimental studies have found that: the stepwise bent of press the certain condition design is vibrated knife bar, when its resonance, thick section has the different vibration displacement regularities of distribution with thin segment, derive through theory, thin segment end face (being the point of a knife place) vibration amplitude with the ratio R of thick section antinodal point (exciting point place) amplitude is:

R＝1.41[β ₁β ₂T ₁₁λ ₁₁（T ₁₂λ ₁₂-

I ₁T ₂₁λ ₂₁/I ₂·（1+COSλ ₁₂L ₂）+

T ₂₂λ ₂₂COSλ ₁₂L ₂）+β ₁β ₂

（I ₁T ₁₁λ ₁₁/I ₂+T ₂₂λ ₂₂）.

T ₂₁λ ₂₁COSλ ₁₂L ₂COSλ ₁₁L ₁-

β ₁α ₂T ₁₁λ ₂₁T ₂₁（I ₁P ₁₁/T ₁₂+

I ₂P ₂₂/T ₁₂）Sinλ ₁₂L ₂Sinλ ₁₁L ₁+

β ₁β ₂T ₂₁λ ₂₁（T ₁₂λ ₁₂+T ₁₁λ ₁₁I ₁/I ₂）

COSλ ₁₁L ₁]

Each symbolic significance is as follows in the formula:

T _1i= (ρω2)/(K′Gλ1′) + λ _1i；

T ₂₁= λ ₂₁- (ρω ²)/(K′Gλ _2′) ；

$P_{1i}=E{\mathrm{\λ}}_{1i}^2-{\mathrm{\ρ\ω}}^2;$ $p_{2l}={\mathrm{E\λ}}_{2l}^2+{\mathrm{\ρ\ω}}^2$

${\mathrm{\α}}_i=1/{\mathrm{EI}}_i({\mathrm{\λ}}_{1i}^2+{\mathrm{\λ}}_{2i}^2);$

${\mathrm{\β}}_i=1/(T_{1i}{\mathrm{\λ}}_{1i}+T_{2i}{\mathrm{\λ}}_{2i})$

E, ρ, G are flexural vibrations knife bar material characteristic parameter; K ' is the cross section uneven distribution coefficient of shear stress, I ₁Be cross section rotary inertia; S ₁Be sectional area;

λ _1i= ［ a / 2 + (a ²/ 4 + b ₁) ^1/2］ ^1/2;

λ _2i= ［ -a / 2 + (a ²/ 4 + b ₁) ^1/2］ ^1/2;

a=(1+E/K′G)ω ²/C ²;

b ₁= ω ²S i / C 2I _i·(1 - (ω ²)/(C 2) · (I i)/(S _I) · (E)/(K′G)

C＝（E/ρ） ^1/2;

ω=2 π f(f are vibration frequency);

i＝1、2。

Thin segment length L when stepwise bent vibration knife bar ₂=9mm, is L highly respectively at thick segment length, width ₁=100mm, b ₁=20mm, h ₁During=15mm, the secondary luffing of calculating with formula (1) than R with the aspect ratio h of thin segment with thick section ₂/ h ₁, width compares b ₂/ b ₁The theoretical curved surface that changes is seen Fig. 5.The actual curved surface of the R that is obtained by experiment under the same terms is seen Fig. 6, and each grid intersection point is an experimental point among the figure.As seen from the figure, the theoretical curved surface that calculates matches basically with the experiment curved surface.

For flexural vibrations knife bar dimension series commonly used in the ultrasonic vibration cutting device, flexural vibrations secondary luffing is than the general 2-4 that reaches of R.After adopting this technical scheme, solved foregoing problems preferably: promptly: 1) adopt the general compressional vibration luffing of non-combined type bar can obtain bigger amplitude at the point of a knife place.2) make vibrational system can adopt a few thing stable performance, be subjected to the fluctuation of load to influence little compressional vibration luffing bar (as taper luffing bar), and the task of further increasing the luffing ratio is born by the flexural vibrations knife bar.3) though point of a knife place amplitude is bigger, thick section vibration is not strong, thereby helps the knife bar clamping.4) owing to adopt symmetrical expression double-pole header structure, big, the good rigidity of bearing stride not only, and because the available other end in end wearing and tearing back, reface simultaneously in two ends then, thereby make the position of the back exciting point of refacing still be positioned at antinodal point place in the middle part of the flexural vibrations knife bar more exactly.

Ultrasonic vibration cutting device of the present invention compared with prior art, have that cutter is easy for installation, the resonance adjustment easily, steady operation and other merits, no matter be new cutter or reface after cutter, the back is installed gets final product resonance as long as adjust electric generator frequency turn-knob a little, the knife bar clamping is reliable, and it is few respectively to connect connection point and the heating of clamping point, near room temperature, the required precision of knife bar anchor clamps is lower, and manufacturing process is simple.

Accompanying drawing 1 is a ultrasonic vibration cutting device structure chart of the present invention;

Fig. 2 is the side view of Fig. 1;

Fig. 3 is the structure chart of flexural vibrations knife bar;

Fig. 4 is the side view of Fig. 3;

Fig. 5 is the theoretical surface chart that changes with sectional dimension than R with the secondary luffing that formula (1) is calculated;

Fig. 6 is the actual surface chart that is changed with sectional dimension than R by the secondary luffing that experimental verification obtains;

Among Fig. 1,2,3, (1) is cooling jacket, and (2) are ultrasonic transducer, (3) be compressional vibration luffing bar, (4) are the flexural vibrations knife bar, and (5) are the knife bar anchor clamps, (6) be carbide chip, (7) are the knife bar thin segment, and (8), (9) are abrupt change of cross-section place.

Among Fig. 5,6, b ₂/ b ₁Be the width ratio of stepwise bent vibration knife bar thin segment and thick section, h ₂/ h ₁Be the aspect ratio of thin segment and thick section, R is a secondary luffing ratio.

Accompanying drawing the 1, the 2nd, the embodiment of ultrasonic vibration cutting device of the present invention, flexural vibrations knife bar (4) is made symmetrical stairstepping, the centre is thick, two ends are thin, promptly (4) section is thick, (7) section is thin, the ratio of its height is equal to or less than 1/2, the ratio of width is equal to or less than 1/2, thin segment is about 1/4 with the ratio of thick section sectional area, being provided with taper hole at thick section middle part is connected with compressional vibration luffing bar (3), at compressional vibration luffing bar output amplitude during, can obtain the amplitude more than the 15 μ m at the point of a knife place less than 8 μ m.Clamp with the side of knife bar anchor clamps at the flexural vibrations knife bar.

Claims (1)

1, a kind of ultrasonic vibration cutting device of mainly forming by cooling jacket (1), ultrasonic transducer (2), compressional vibration luffing bar (3), flexural vibrations knife bar (4), knife bar anchor clamps (5), it is characterized in that flexural vibrations knife bar (4) is thick in the middle of being, thin its aspect ratio in two ends equals 1/2 or less than 1/2, width is than equaling 1/2 or less than 1/2 symmetrical expression stairstepping bar, at the knife bar two ends carbide chip is arranged all, its thin segment is less than or equal to 1/4 with the ratio of thick section sectional area, and locates clamping in two abrupt changes of cross-section (8), (9).

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