CN102445317A - Experimental apparatus for accurately measuring characteristic parameters of tool holder-main shaft combined part - Google Patents

Abstract

An experimental apparatus for accurately measuring the characteristic parameters of a tool holder-main shaft combined part comprises a main shaft, a main shaft end cover, a preloaded bolt, a blind rivet with an elongated connecting rod and a tool holder. The blind rivet is connected to the tool holder, and fixed to the main shaft end cover at the tail end of the main shaft through the elongated connecting rod and by means of the preloaded bolt; the torque of a torque spanner is adjusted and a foil gauge in the preloaded bolt displays the present preload on a computer through a strain gauge; therefore, the acting force or broaching force between the tool holder and the main shaft is adjusted. The tool holder, the main shaft and the tool holder-main shaft system are tested, respectively, so that the characteristic parameters of the tool holder-main shaft combined part are identified without introducing excessive errors; and the apparatus offers the basis of the prediction of cutting stability and the structure optimization of the tool holder.

Description

The experimental provision of a kind of accurate measurement handle of a knife-joint portion characteristic parameter

Technical field

The present invention relates to a kind of experimental provision, can accurately obtain the handle of a knife-main shaft joint portion characteristic parameter of handle of a knife under different broach force effects, belong to Machine Design, manufacturing, field tests in order to accurate measurement handle of a knife-main shaft joint portion characteristic parameter.

Background technology

The identifying of handle of a knife-main shaft joint portion characteristic parameter mainly contains following mode:

Handle of a knife-main shaft joint portion characteristic parameter identification process is accomplished in consideration on complete machine or experiment table; This dual mode all at first measure before the assembling frequency response function between the handle of a knife and main shaft joint portion point on the Knife handle structure and handle of a knife end exciting point and cutter handle combining part point between frequency response function; Measure the frequency response function between the main shaft and cutter handle combining part point on the main shaft then; At last handle of a knife is installed on the main shaft; Measure the transport function between the exciting point on the handle of a knife, above data are updated to the characteristic parameter that the identification formula can calculate handle-main shaft joint portion.Though this dual mode can pick out the characteristic parameter of handle of a knife-main shaft joint portion; But at the frequency response function between main shaft and the cutter handle combining part point on the measurement assembling forward spindle; And when measuring the transport function between the handle of a knife exciting point of assembling back; Because the influence of factors such as motor, servomechanism installation, cooling system and other joint portions, the identification result error is bigger, can not accurately reflect real connection situation.

Summary of the invention

The objective of the invention is to; Deficiency to test existence on complete machine and experiment table; The experimental provision of a kind of accurate measurement handle of a knife-main shaft joint portion characteristic parameter is provided; Reduce the influence of additional interference factor that noise and other parts bring through manufacturing and designing new experimental provision, and can utilize the least squares identification formula to find the solution, thereby improve identification precision identification result.The present invention can be implemented in the accurate identification of handle of a knife under the different broach forces-main shaft joint portion characteristic parameter.

The present invention adopts following technological means to realize:

A kind of experimental provision of measuring handle of a knife-main shaft joint portion characteristic parameter comprises handle of a knife 1, main shaft 2, blind rivet 3, extension rod 4, main shaft end cap 5, pre-stressed bolt 6; Main shaft end cap 5 is fixed on main shaft 2 ends, and handle of a knife 1 links together with blind rivet 3, and blind rivet 3 connects extension rod 4 and is fixed on the center pit on the main shaft end cap 5 through pre-stressed bolt 6, thereby has realized being connected of handle of a knife 1 and main shaft 2; Pre-stressed bolt 6 is through electric bridge, and dynamic strain indicator links to each other with computing machine, utilizes dial torque wrench to regulate pre-stressed bolt 6, can demonstrate the size of current handle of a knife-axis system broach force on computers, thereby realizes the adjustable of broach force; Handle of a knife 1 is provided with acceleration transducer 8 away from an end of main shaft end cap 5, is used for power hammer 7, acceleration transducer 8, computing machine and the dynamic strain indicator of handle of a knife 1 application of force are all linked to each other with LMS mode test macro.

Main shaft end cap 5 is connected through bolt with main shaft 2 ends.

It is the modal forces hammer of PCB-086C03 that said power hammer 7 adopts model; It is the acceleration transducer of PCB-333B30 that said acceleration transducer 8 adopts model; Dynamic strain indicator adopts the BZ2668 dynamic strain indicator.

The present invention compared with prior art has following remarkable advantages and beneficial effect:

The present invention is through removing devices such as servo-drive system, cooling and broaching tool on the lathe; Thereby the noise that above structure is brought when having reduced system test has improved identification precision, simultaneously; In order to analyze under the different condition situation of change to handle of a knife-main shaft joint portion rigidity; The adjusting of broach force is added in this experimental provision, and this regulating device quality is little, can not bring very big interference to integrally-built frequency response function; So experimental provision can accurately be measured broaching tool handle of a knife-main shaft joint portion characteristic parameter, this experimental provision can also be measured other types handle of a knife-main shaft characteristic parameter.

Description of drawings

Fig. 1 measures the connection synoptic diagram of the experimental provision of broaching tool handle of a knife-main shaft joint portion characteristic parameter;

Fig. 2 is the main shaft synoptic diagram;

Fig. 3 is a main shaft end cap synoptic diagram;

Fig. 4 is that handle of a knife-main shaft connects synoptic diagram

Among the figure: 1, handle of a knife, 2, main shaft, 3, blind rivet, 4, extension rod, 5, the main shaft end cap, 6, pre-stressed bolt, 7, the power hammer, 8, acceleration transducer.

Embodiment

4 couples of the present invention are described further below in conjunction with Figure of description 1-accompanying drawing:

The ultimate principle of the experimental provision of the accurate measurement handle of a knife-main shaft joint portion characteristic parameter of present embodiment is to get rid of devices such as servo, cooling and broaching tool on the lathe; And according to actual conditions; Through adding the size that pre-stressed bolt is regulated broach force; And do not have the outer influence factor of plus during to integrated testability, thereby reached the accurate identification of handle of a knife-main shaft joint portion characteristic parameter.This experimental provision is as shown in Figure 1, comprises handle of a knife 1, main shaft 2, blind rivet 3, extension rod 4, main shaft end cap 5, pre-stressed bolt 6.Main shaft end cap 5 is bolted to main shaft 2 ends through 4; Handle of a knife 1 links together with blind rivet 3, and blind rivet 3 is through extension rod 4 and utilize pre-stressed bolt 6 to be fixed on the center pit on the main shaft end cap 5, thereby has realized being connected of handle of a knife 1 and main shaft 2; Pre-stressed bolt links to each other with computer through strainmeter; Utilize dial torque wrench to regulate pre-stressed bolt, can read the size of corresponding power on computers, realized the adjustable of broach force.Test handle of a knife, main shaft respectively, and the frequency response function of handle of a knife-axis system under the effect of different broach forces, above data are updated to the characteristic parameter accurately that can obtain handle of a knife under the different broach forces-main shaft joint portion in the identification formula.

Being illustrated in figure 2 as the main shaft synoptic diagram, is main shaft end cap synoptic diagram like Fig. 3;

Fig. 4 is that handle of a knife-main shaft connects synoptic diagram, and its concrete identification process is following:

Basic thought based on mechanical impedance; Be the experimental process structure with one-piece construction is discrete, the application of mechanical impedance method is set up the kinetics equation of each minor structure respectively; According to interstructural actual connection situation; Confirm the displacement and the power constraint condition at joint face place,, obtain the integrally-built equation of motion and kinematic behavior thereby the equation of motion of each sub-structures integrated through the constraint condition between the minor structure.The kinetics equation of structure can be written as

-ω ²MX+iωCX+KX＝F

The form of being write as mechanical impedance does

ZX＝F (1)

Wherein

Z＝-ω ²M+iωC+K

The frequency response function expression formula is write as in (1) does

X＝HF (2)

In the following formula, X is the displacement response of structure, and H is the frequency response function of structure, and F is the acting force of structure

Like the handle of a knife-main shaft joint portion model of Fig. 4 for simplifying, The model can be divided into 3 parts: Knife handle structure A, and main axle structure B and unit, the joint portion C that forms by n spring-damper, wherein spring-damper and main shaft and handle of a knife adopt and are rigidly connected.E is the exciting point on the handle of a knife A, and point 1,2...n are the binding site on the Knife handle structure A, and some n+1, n+2...2n are the binding site on the main axle structure B, and some 2n+1,2n+2...3n are the measurement point on the main axle structure B.Set up the kinetics equation of each sub-structures of system according to formula (2), the kinetics equation of A structure does before the assembling

Brief note is:

$\left\{\begin{array}{c}{X}_e^A\\ X_J^A\end{array}\right\}=\left[\begin{array}{cc}{H}_{e.e}^A& H_m^A\\ H_{J.e}^A& H^A\end{array}\right]\·\left\{\begin{array}{c}{F}_e^A\\ F_J^A\end{array}\right\}---\left(3\right)$

Each frequency response function can be write as the alphabetical A of unified form

and represented that this is the frequency response function of structure A in the following formula; Q is the structural exciting point of A, and p representes the structural response point of A.

Can get by (3) second formulas

$F_J^A={\left(H^A\right)}^{-1}\·(X_J^A-H_{J.e}^A{F}_e^A)---\left(4\right)$

The equation of motion of B structure is before the assembling:

$\left\{\begin{array}{c}{X}_{n+1}^B\\ X_{n+2}^B\\ M\\ X_{2n}^B\\ ---\\ X_{2n+1}^B\\ X_{2n+2}^B\\ M\\ X_{3n}^B\end{array}\right\}=\left\{\begin{array}{cccc}{H}_{(n+1).(n+1)}^B& H_{(n+1).(n+2)}^B& L& H_{(n+1).2n}^B\\ H_{(n+2).(n+1)}^B& H_{(n+2).(n+2)}^B& L& H_{(n+2).2n}^B\\ M& \mathrm{<figure-callout\; id="2n"\; label="M\; M\; H"\; filenames="HDA0000093958460000022.png"\; state="\{\{state\}\}">M</figure-callout>}& & M\\ H_{}^{}{}_{2n.(n+1)}^B& H_{2n.(n+2)}^B& L& H_{2n.2n}^B\\ & ---& & \\ H_{(2n+1).(n+1)}^B& H_{(2n+1).(n+2)}^B& L& H_{(2n+1).2n}^B\\ H_{(2n+2).(n+1)}^B& H_{(2n+2).(n+2)}^B& L& H_{(2n+2).2n}^B\\ M& M& & M\\ H_{\left(3n\right).(n+1)}^B& H_{\left(3n\right).(n+2)}^B& L& H_{3n.2n}^B\end{array}\right\}\&CenterDot;\left\{\begin{array}{c}{F}_{n+1}^B\\ F_{n+2}^B\\ M\\ F_{2n}^B\end{array}\right\}$

Brief note does

$\left[\begin{array}{c}{X}_J^B\\ X_m^B\end{array}\right]=\left[\begin{array}{c}{H}_1^B\\ H_2^B\end{array}\right]\&CenterDot;\left[F_J^B\right]---\left(5\right)$

Can get by (5)

$\left\{\begin{array}{c}{F}_J^B={\left(H_1^B\right)}^{-1}\&CenterDot;X_J^B\\ F_J^B={\left(H_2^B\right)}^{-1}\&CenterDot;X_m^B\end{array}\right.---\left(6\right)$

Make that first formula and second formula equate in (6), have

$H_J^B=H_1^B\&CenterDot;{\left(H_2^B\right)}^{-1}\&CenterDot;H_m^B---\left(7\right)$

Can know by the physical characteristics on the faying face

$F_J^A=-F_J^B---\left(8\right)$

With the second formula substitution (8) in formula (3) and (5), and rearrange and to get

$H_J^A=H_{J.e}^A-H^A\&CenterDot;{\left(H_2^B\right)}^{-1}\&CenterDot;H_m^B---\left(9\right)$

Relation by between structural plane power and the faying face displacement can be known

$F_J^B=\mathrm{\&alpha;}(X_J^A-X_J^B)---\left(10\right)$

In the formula, α is the Dynamic Stiffness Matrix of faying face

With second formula, formula (7) and (9) substitution formula (10) in the formula (6), and rearrange and to discern formula based on the handle of a knife-main shaft joint portion characteristic parameter of frequency response function

$\left\{\begin{array}{c}{H}_2^B\mathrm{g\&alpha;}(H_{J.e}^A-H^A\&CenterDot;{\left(H_2^B\right)}^{-1}\&CenterDot;H_m^B-H_1^B\&CenterDot;{\left(H_2^B\right)}^{-1}\&CenterDot;H_m^B)=H_m^B\\ H^A\mathrm{g\&alpha;}(H_{J.e}^A-H^A\&CenterDot;{\left(H_2^B\right)}^{-1}\&CenterDot;H_m^B-H_1^B\&CenterDot;{\left(H_2^B\right)}^{-1}\&CenterDot;H_m^B)=(H_{J.e}^A-H_J^A)\end{array}\right.---\left(11\right)$

be comprehensive before on the A structure handle of a knife transport function between exciting point and the binding site vectorial

H ^ABe the transfer function matrix between the binding site on the A structure handle of a knife before comprehensive

is the transfer function matrix between the binding site on the comprehensive preceding B structure main shaft

be comprehensive before the transfer function matrix between measurement point and the binding site on the B structure main shaft

is the transport function between exciting point and the measurement point on the handle of a knife-axis system of assembling back

Two formulas have unified form in the formula (11), can be abbreviated as

A in the following formula, B, C are respectively three corresponding matrixes, M, and N, L are respectively the dimension of corresponding matrix, work as M, and during N＞L, matrix A and B are nonsingular, and this moment, Dj had unique solution, and the least square solution of formula (12) does

What should explain at last is: above embodiment only in order to the explanation the present invention and and unrestricted technical scheme described in the invention; Therefore, although this instructions has carried out detailed explanation to the present invention with reference to each above-mentioned embodiment,, it will be understood by those of skill in the art that still and can make amendment or be equal to replacement the present invention; And all do not break away from the technical scheme and the improvement thereof of the spirit and the scope of invention, and as changing the type identification other types handle of a knife-main shaft joint portion characteristic parameter of spindle hole, it all should be encompassed in the middle of the claim scope of the present invention.

Claims (3)

1. an experimental provision of measuring handle of a knife-main shaft joint portion characteristic parameter comprises handle of a knife (1), main shaft (2), blind rivet (3), extension rod (4), main shaft end cap (5), pre-stressed bolt (6); It is characterized in that: main shaft end cap (5) is fixed on main shaft (2) end; Handle of a knife (1) links together with blind rivet (3); Blind rivet (3) connects extension rod (4) and is fixed on the center pit on the main shaft end cap (5) through pre-stressed bolt (6), thereby has realized being connected of handle of a knife (1) and main shaft (2); Pre-stressed bolt (6) is through electric bridge, and dynamic strain indicator links to each other with computing machine, utilizes dial torque wrench to regulate pre-stressed bolt (6), can demonstrate the size of current handle of a knife-axis system broach force on computers, thereby realizes the adjustable of broach force; Handle of a knife (1) is provided with acceleration transducer (8) away from an end of main shaft end cap (5), is used for power hammer (7), acceleration transducer (8), computing machine and the dynamic strain indicator of handle of a knife (1) application of force are all linked to each other with LMS mode test macro.

2. a kind of experimental provision of measuring handle of a knife-main shaft joint portion characteristic parameter according to claim 1 is characterized in that: main shaft end cap (5) is connected through bolt with main shaft (2) is terminal.

3. a kind of experimental provision of measuring handle of a knife-main shaft joint portion characteristic parameter according to claim 1 is characterized in that: it is the modal forces hammer of PCB-086C03 that said power hammer (7) adopts model; It is the acceleration transducer of PCB-333B30 that said acceleration transducer (8) adopts model; Dynamic strain indicator adopts the BZ2668 dynamic strain indicator.

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