CN102445317B - 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 in order to accurate measurement handle of a knife-main shaft joint portion characteristic parameter, can accurately obtain the handle of a knife of handle of a knife under different broach force effects-main shaft joint portion characteristic parameter, belong to Machine Design, manufacture, field tests.

Background technology

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

Consideration completes handle of a knife-main shaft joint portion Characteristic parameter identification process on complete machine or experiment table, these two kinds of modes all at first measure before assembling the frequency response function between handle of a knife and main shaft joint portion point on Knife handle structure and handle of a knife end exciting point and cutter handle combining part point between frequency response function, then measure the frequency response function between main shaft and cutter handle combining part point on main shaft, finally handle of a knife is arranged on main shaft, measure the transport function between exciting point on handle of a knife, above data are updated to the characteristic parameter that the identification formula can calculate handle-main shaft joint portion.Although these two kinds of modes can pick out the characteristic parameter of handle of a knife-main shaft joint portion, but the frequency response function on measurement assembling forward spindle between main shaft and cutter handle combining part point, and while measuring after assembling the transport function between handle of a knife exciting point, impact due to factors such as motor, servomechanism installation, cooling system and other joint portions, the identification result error is larger, can not accurately reflect real connection.

Summary of the invention

The object of the invention is to, for the deficiency that test exists 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, by manufacturing and designing the impact on identification result of additional interference factor that new experimental provision comes noise reduction and other parts to bring, and can utilize the least squares identification formula to be solved, thereby improve identification precision.The present invention can realize the accurate identification of handle of a knife under 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, comprise 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 main shaft end cap 5 by pre-stressed bolt 6, thereby has realized the connection of handle of a knife 1 and main shaft 2; Pre-stressed bolt 6 is by electric bridge, and dynamic strain indicator is connected with computing machine, utilizes dial torque wrench to regulate pre-stressed bolt 6, can demonstrate on computers the size of current handle of a knife-axis system broach force, thereby realize 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, for the hammer of the power to handle of a knife 1 application of force 7, acceleration transducer 8, computing machine and dynamic strain indicator, all with LMS mode test macro, is connected.

Main shaft end cap 5 is bolted to connection with main shaft 2 ends.

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

The present invention compared with prior art, has following obvious advantage and beneficial effect:

The present invention is by removing servo-drive system on lathe, the devices such as cooling and broaching tool, thereby the noise that while having reduced system test, above structure is brought, improved identification precision, simultaneously, in order to analyze under different condition the situation of change to handle of a knife-main shaft joint portion rigidity, the adjusting of broach force is added in this experimental provision, this regulating device quality is little, can not bring very large 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.

The accompanying drawing explanation

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

Fig. 2 is the main shaft schematic diagram;

Fig. 3 is main shaft end cap schematic diagram;

Fig. 4 is handle of a knife-main shaft connection diagram

In 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

Below in conjunction with Figure of description 1-accompanying drawing 4, the invention will be further described:

The ultimate principle of the experimental provision of the accurate measurement handle of a knife of the present embodiment-main shaft joint portion characteristic parameter is the devices such as servo, cooling and broaching tool of getting rid of on lathe, and according to actual conditions, the size of by adding pre-stressed bolt, regulating broach force, and there is no 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 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 by 4, handle of a knife 1 links together with blind rivet 3, blind rivet 3 is by extension rod 4 and utilize pre-stressed bolt 6 to be fixed on the center pit on main shaft end cap 5, thereby realized the connection of handle of a knife 1 and main shaft 2, pre-stressed bolt is connected with computer by strainmeter, utilize dial torque wrench to regulate pre-stressed bolt, can read on computers the size of corresponding power, realized the adjustable of broach force.Test respectively handle of a knife, main shaft, and the frequency response function of handle of a knife-axis system under the effect of different broach forces, above data are updated in the identification formula to the characteristic parameter accurately that can obtain handle of a knife under different broach forces-main shaft joint portion.

Be illustrated in figure 2 the main shaft schematic diagram, as Fig. 3 is main shaft end cap schematic diagram;

Fig. 4 is handle of a knife-main shaft connection diagram, and its concrete identification process is as follows:

Basic thought based on mechanical impedance, by one-piece construction discrete be several minor structures, the application of mechanical impedance method, set up respectively the kinetics equation of each minor structure, according to interstructural actual connection, determine displacement and the power constraint condition at joint face place, by the constraint condition between minor structure, thereby the equation of motion of each minor structure is integrated and obtains the integrally-built equation of motion and kinematic behavior.The kinetics equation of structure can be written as

-ω ²MX+iωCX+KX＝F

The form of being write as mechanical impedance is

ZX＝F (1)

Wherein

Z＝-ω ²M+iωC+K

(1) is write as to the frequency response function expression formula is

X＝HF (2)

In above formula, the displacement response that X is structure, the frequency response function that H is structure, the acting force that F is structure

As Fig. 4 is the handle of a knife simplified-main shaft joint portion model, whole model can be divided into 3 parts: Knife handle structure A, and main axle structure B and unit, the joint portion C formed by n spring-damper, wherein spring-damper and main shaft and handle of a knife employing are rigidly connected.E is the exciting point on handle of a knife A, puts 1,2...n is the binding site on Knife handle structure A, and some n+1, n+2...2n are the binding site on main axle structure B, and some 2n+1,2n+2...3n are the measurement point on main axle structure B.Set up the kinetics equation of each minor structure of system according to formula (2), before assembling, the kinetics equation of A structure is

Brief note is:

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

In above formula, each frequency response function can be write as unified form

Letter A means that this is the frequency response function of structure A, and q is the structural exciting point of A, and p means the structural response point of A.

By (3) second formulas, can be obtained

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

Before assembling, the equation of motion of B structure is:

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

Brief note is

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

By (5), can be obtained

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

Make the first formula and the second formula in (6) equate have

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

From the physical characteristics on faying face

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

By the second formula substitution (8) in formula (3) and (5), and rearrange and can obtain

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

From the relation between structural plane power and faying face displacement

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

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

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

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

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

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

For the transfer function matrix between binding site on B structure main shaft before comprehensive

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

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

In formula (11), two formulas have unified form, can be abbreviated as

A in above formula, B, C is respectively three corresponding matrixes, M, N, L is respectively the dimension of corresponding matrix, works as M, and during N>L, matrix A and B are nonsingular, and now Dj has unique solution, and the least square solution of formula (12) is

Finally it should be noted that: above embodiment is only in order to illustrate the present invention and unrestricted technical scheme described in the invention; Therefore, although this instructions has been described in detail 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 modify or be equal to replacement the present invention; And all do not break away from technical scheme and the improvement thereof of the spirit and scope of invention, as the type identification other types handle of a knife that changes spindle hole-main shaft joint portion characteristic parameter, it all should be encompassed in the middle of claim scope of the present invention.

Claims (3)

1. an experimental provision of measuring handle of a knife-main shaft joint portion characteristic parameter, comprise 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 main shaft end cap (5) by pre-stressed bolt (6), thereby has realized the connection of handle of a knife (1) and main shaft (2); Pre-stressed bolt (6) is by electric bridge, and dynamic strain indicator is connected with computing machine, utilizes dial torque wrench to regulate pre-stressed bolt (6), can demonstrate on computers the size of current handle of a knife-axis system broach force, thereby realize 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), for the hammer of the power to handle of a knife (1) application of force (7), acceleration transducer (8), computing machine and dynamic strain indicator, all with LMS mode test macro, is connected.

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 bolted to connection with main shaft (2) end.

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: the modal forces hammer that described power hammer (7) employing model is PCB-086C03; Described acceleration transducer (8) adopts the acceleration transducer that model is PCB-333B30; Dynamic strain indicator adopts the BZ2668 dynamic strain indicator.

Images