CN202501880U - Device for measuring effective flow rate and dynamic pressure of grinding fluid - Google Patents

Abstract

The utility model discloses a device for measuring an effective flow rate and a dynamic pressure, which not only can measure the effective flow rate of the grinding fluid passing through between a sand wheel and a work piece, but also can measure the dynamic pressure of the grinding fluid in a grinding area. The device mainly consists of a differential screw mechanism, a rubber baffle, an effective flow separation board, the work piece, a scraping board, a collecting groove and a piezoelectric pressure sensor, wherein the work piece is as wide as the sand wheel; the effective flow separation board is fixedly arranged on a sliding board of the differential screw mechanism; a screw rod controls the effective flow separation board to transversely move, so as to control the effective flow separation board to approach to or depart from the sand wheel; the scraping board is fixedly arranged at a position on the effective flow separation board, which is matched with the sand wheel; the collecting groove is connected on the work piece; the buffer baffle is fixedly arranged on the sliding board of the differential screw mechanism; the piezoelectric pressure sensor is fixedly arranged inside the work piece; the pressure of the grinding fluid in the grinding area of the work piece of the sand wheel is transmitted to the piezoelectric pressure sensor through a small hole on the work piece, so as to measure the dynamic pressure; and furthermore, the differential screw mechanism, the work piece and the collecting groove are directly fixedly arranged on a working table of a grinding machine.

Description

The measurement mechanism of grinding fluid effective discharge rate and dynamic pressure

Technical field

The utility model relates to the measurement mechanism of a kind of grinding fluid effective discharge rate and dynamic pressure.

Background technology

The grinding processing method Technological adaptability is extremely strong; Applied range; Can carry out famine, thick, essence and superfinishing to various materials such as metal, pottery, glass, stone material, fire resistive material, concrete, bone, compound substances; Many difficult-to-machine materials can only be used grinding at present, and at present known grinding machine is above 3000 kinds.What is more important, the final precision and the surface quality of most machined part are determined by grinding process.Therefore, grinding be that mechanical processing industry is the most basic, one of most important process.

Grinding, the energy that removal unit materials volume is consumed produces a large amount of heat much larger than other cutting working method in grinding area, and these heat pass and are dispersed on smear metal, cutter and the workpiece.The grinding heat effect is very big to workpiece surface quality and usability influence.Particularly when temperature surpasses a certain critical value on emery wheel/workpiece interface; Will cause the fire damage (oxidation, burn, residual tension and the crackle on surface) on surface; Its result will cause the wear resistance of part to reduce; The anti-fatigue performance variation, thus the serviceable life and the reliability of part reduced.In addition, the accumulation temperature rise of workpiece in the grinding cycle causes the dimensional accuracy of workpiece, the serviceable life of form accuracy sum of errors emery wheel to be reduced.Therefore, the temperature of effectively controlling grinding area reduces the surface of the work fire damage, is research grinding principle and the important topic that improves quilt mill piece surface integrality.

In grinding, grinding fluid occupies an important position because that it has is lubricated, cooling, cleaning, chip removal, antirust, reduce grinding force and improve effects such as workpiece surface quality, be one of indispensable production factors of Grinding Process.The coefficient of heat conductivity of water is 6 times of mineral oil, adds part mineral oil and little additive in the water, can obtain that cost is low, the emulsion of perfect heat-dissipating and microemulsion.But because environmental protection requirement, the waste liquid of lubricating fluid must pass through processing, could discharge after up to standard, and liquid waste processing is costly, up to 54% of grinding fluid cost, makes people have to grinding fluid is reappraised.Germany did investigation to automobile factory, and the result who obtains is: tool expense only accounts for the 2%-4% of processing cost; But the expense relevant with grinding fluid but accounts for the 7%-17% of cost, be tool expense 3-5 doubly.Energy consumption in the machining, the power that spindle operation needs only accounts for 20%, and the energy consumption relevant with cooling and lubricating but accounts for 53%.This explanation is owing to the requirement of " environmental protection and low-carbon (LC) ", and the cheap advantage of emulsion does not exist, has become the obstacle that influences production development.In the face of the needs of human social, imperative towards environmental friendliness, resource-effective low-carbon (LC) manufacturing.

For reducing the grinding area temperature, extensively adopt cast-type feed flow method reduction grinding area temperature from big flow grinding fluid to grinding area that supply with in the production.But this feed liquid method is because " airbond " that the emery wheel high speed rotating forms makes grinding fluid get into very difficulty of grinding area; Actual " the effective discharge rate " that gets between emery wheel/workpiece is merely the 5%-40% of nozzle flow; A large amount of grinding fluids can't get into emery wheel/workpiece interface at all; Grinding fluid just plays the effect of cooling workpiece substrate, causes grinding burn and surface of the work integrality to worsen; The grinding fluid of adding a large amount of supplies forms hydrodynamic pressure and fluid introducing power at emery wheel and workpiece wedge gap, makes grinding wheel spindle produce deflection deformation, causes actual cutting-in to reduce.Therefore this feed liquid method not only makes processing work produce the shape and size error, and wastes grinding fluid in a large number, increases supply and handles the cost of grinding fluid, and environment is caused great injury.

Present improved grinding fluid method for implanting has: auxiliary air-flow method, high-pressure injection method, the interior cooling method of emery wheel, the radial jet shock peening heat exchange method etc. of blocking of air register.Air register is assisted and blocked the air-flow method is at emery wheel outer peripheral face and side adjustable air register to be set, and hinders air and flows fast to the arc district.Baffle plate and wheel face gap should be as far as possible little, reducing and can adjust continuously with grinding wheel diameter.Adopt air register, wheel face can be better wetted, can prevent that also grinding fluid from splashing to the both sides.High-pressure injection method is to improve the pressure of supplying with grinding fluid, sprays grinding fluid at a high speed, makes it can break through airflow barrier and gets into the arc district, and grinding heat is taken away rapidly, and general working pressure is at several MPa.Cooling method is the side opening feed flow that utilizes emery wheel radial hole feed flow or utilize abrasive disc in the emery wheel.Utilize the effect of centrifugal force seepage that grinding fluid is thrown away from periphery through the emery wheel pore, get into grinding area.System need dispose high-precision filtration unit, in order to avoid emery wheel stops up.The radial hole high-pressure injection grinding fluid of radial jet shock peening heat exchange method utilization fluting CBN emery wheel makes grinding fluid with very high-speed (can reach 100m/s), near vertically impacting arc district surface of the work.Because high-pressure spray can break through easily and forms stopping of steam film, guarantee grinding fluid and surface of the work continue contact, thereby just have ready conditions and break through into the obstacle of film boiling; The grinding arc area temperature is reduced, and this liquid coolant method for implanting does not receive the influence of emery wheel airbond, and heat exchange efficiency is high; Emery wheel was prone to produce vibration when shortcoming was work; Cause processing work precision and surface quality to reduce, and the liquid-supplying system complex structure, cost is high.

Grinding fluid reality is called the effective discharge rate through the ratio of the flow between emery wheel/workpiece and nozzle flow; The measurement grinding fluid all is improved on the basis of existing grinding machine liquid feed device through the device of the effective discharge rate of grinding area at present; Automaticity and measuring accuracy are limited, more not energy measurement effective discharge rate and grinding fluid hydrodynamic pressure.

The utility model content

The purpose of the utility model is for addressing the above problem; The measurement mechanism of a kind of grinding fluid effective discharge rate and dynamic pressure is provided; It both the energy measurement grinding fluid through the effective discharge rate between emery wheel/workpiece, and the grinding fluid hydrodynamic pressure of energy measurement grinding area.

For realizing above-mentioned purpose, the utility model adopts following technical scheme:

The measurement mechanism of a kind of grinding fluid effective discharge rate and dynamic pressure, it comprises mainly and being made up of differential screw mechanism, rubber baffle, effective discharge separating plate, workpiece, scraper plate, feeder and piezoelectric pressure indicator; Wherein, the width of the workpiece equates with grinding wheel width; The effective discharge separating plate is fixed on the slide plate of differential screw mechanism, by laterally moving of screw rod control effective discharge separating plate make its near or leave emery wheel; The position of on the effective discharge separating plate, matching with emery wheel is provided with the scraper plate that is connected, and feeder is connected on the workpiece, and rubber baffle is fixed on the slide plate of differential screw mechanism; Piezoelectric pressure indicator is fixed on interior, and the pressure of emery wheel workpiece grinding area grinding fluid is delivered on the piezoelectric pressure indicator through the aperture on the workpiece and then measures its dynamic pressure; In addition, differential screw mechanism, workpiece and feeder directly are fixed on the Grinder bench.

The left end of said workpiece has the hole that cooperates with holding screw and has fluting to link to each other with feeder; The right-hand member perforate of workpiece matches with piezoelectric pressure indicator; Wherein have aperture in the top at workpiece; Certain any hydrodynamic pressure is delivered on the piezoelectric pressure indicator through this aperture in the grinding area; The output electric wire of piezoelectric pressure indicator lower end links to each other with extraneous charge amplifier through the groove of workpiece bottom, and the output signal is finally imported in the computer.

Said feeder is the turning shape; The feeder top is provided with thin plate; On the thin-walled of feeder inlet end, have along the slotted hole of short transverse and cooperate with holding screw, workpiece and feeder are screwed into through holding screw in the threaded hole of workpiece left end, along the fixing feeder of width of the workpiece direction.

Said differential screw mechanism mainly is made up of base, screw rod and slide plate, and the helical pitch of screw rod both sides screw thread is different, but the both sides thread rotary orientation is identical, and wherein the helical pitch of A section screw thread is 1.25mm, and the helical pitch of B section screw thread is 1mm; The slide plate bottom is swallow-tail form, is installed in the dovetail groove of base, and it moves by screw rod control, and the displacement s of this differential screw mechanism slide plate does

L wherein _A, l _BBe respectively the lead of screw of screw rod A section and B section, It is the angle that screw rod turns over.

Said effective discharge separating plate is processed by organic glass, and the threaded hole that a side of effective discharge separating plate has 3 certain depths is connected with slide plate, the scraper plate of differential screw mechanism respectively, and the bottom of opposite side has groove, and felt is arranged in groove.

Said scraper plate is processed by elastomeric material, and the both sides of scraper plate have elongated slot, uses bolt again after when being connected with the effective discharge separating plate, can vertically regulating its position.

A kind of method that adopts the measurement mechanism measurement grinding fluid effective discharge rate of grinding fluid effective discharge rate and dynamic pressure, step is following:

1) installs, fixes each parts of device, regulate the screw rod of differential screw mechanism, make the effective discharge separating plate away from workpiece;

2) supply with grinding fluid, start emery wheel, the gap between adjustment emery wheel, workpiece is zero, and emery wheel is alignd with the workpiece both sides of the edge;

3) screw rod of adjusting both sides differential screw mechanism makes the effective discharge separating plate near the contact emery wheel;

4) adjustment worktable, making the horizontal range H of emery wheel axis and effective discharge separating plate right side is 5～10mm, the emery wheel axis is in the left side of effective discharge separating plate right side;

5) stop the emery wheel revolution and supply with, lay scraper plate, regulate its position, make it, use bolt again near the contact emery wheel with grinding fluid;

6) supply with grinding fluid, start emery wheel;

7) collect effective discharge from the feeder endpiece, acquisition time t, t are 5～20min;

8) measure the mass M of the grinding fluid of collecting, bring formula into

Wherein ρ is the density of grinding fluid, can obtain the effective discharge q that collects _Effectively

9) from the flowmeter of hydraulic system, directly read the delivery rate q of nozzle _Spray

10) q has been arranged _EffectivelyAnd q _SprayThereby, calculating the effective discharge rate of grinding fluid, its value is q _Effectively/ q _Spray

11) repeating step 7～10, draw three groups of effective discharge rates, get its mean value;

12) change the parameter that influences effective discharge: the position of grinding wheel speed, nozzle flow, jet velocity and nozzle, angle, measure the effective discharge rate under relevant parameter, thereby study of the influence of each parameter it.

In the said step 12), the mathematical model of effective discharge rate is following:

$u_{\mathrm{\θ}}\frac{{\mathrm{du}}_{\mathrm{\θ}}}{\mathrm{d\θ}}-\frac{\mathrm{\μR\φ}}{k_{\mathrm{\θ}}\mathrm{\ρ}}(v_s-u_{\mathrm{\θ}})=0---\left(1\right)$

$\frac{u_{\mathrm{\&theta;}}^{2}h}{2R}\frac{d^{2}h}{{\mathrm{d\&theta;}}^2}-\frac{h^2}{R}{\left(\frac{d{u}_{\mathrm{\&theta;}}}{\mathrm{d\&theta;}}\right)}^2+\frac{{2u}_{\mathrm{\&theta;}}h}{R}\frac{\mathrm{dh}}{\mathrm{d\&theta;}}\frac{{\mathrm{du}}_{\mathrm{\&theta;}}}{\mathrm{d\&theta;}}+\frac{1}{2}(\frac{1}{k_r}-\frac{1}{k_{\mathrm{\&theta;}}})\frac{{\mathrm{\&mu;<figure-callout\; id="2"\; label="h"\; filenames="HDA0000147534340000062.png"\; state="\{\{state\}\}">h</figure-callout>}}^2}{\mathrm{\&rho;}}\frac{{\mathrm{\&phi;du}}_{\mathrm{\&theta;}}}{\mathrm{d\&theta;}}---\left(2\right)$

$+\frac{{\mathrm{\&mu;\&phi;u}}_{\mathrm{\&theta;}}}{{2k}_r\mathrm{\&rho;}}\frac{\mathrm{hdh}}{\mathrm{d\&theta;}}+\frac{{\mathrm{\&mu;<figure-callout\; id="2"\; label="h"\; filenames="HDA0000147534340000062.png"\; state="\{\{state\}\}">h</figure-callout>}}^2\mathrm{\&phi;}}{2\mathrm{\&rho;}}(v_s-u_{\mathrm{\&theta;}})\frac{d}{\mathrm{d\&theta;}}\left(\frac{1}{k_{\mathrm{\&theta;}}}\right)+u_{\mathrm{\&theta;}}^{2}h-\frac{\mathrm{pR}}{\mathrm{\&rho;}}=0$

In the formula: u _θBe the tangential velocity of grinding fluid at the emery wheel circumference; μ is the kinetic viscosity of grinding fluid; R is the radius of emery wheel; φ is the porosity of emery wheel; ρ is the density of grinding fluid; v _sIt is the peripheral speed of emery wheel; H is the degree of depth that grinding fluid penetrates into the wheel face pore; P is the hydrodynamic pressure of grinding fluid in grinding area; k _θAnd k _rFor grinding fluid at the tangential of wheel face and infiltration coefficient radially,

$\frac{1}{k_{\mathrm{\&theta;}}}=\frac{\mathrm{\&alpha;}{(1-\mathrm{\&phi;})}^2}{{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="HDA0000147534340000062.png"\; state="\{\{state\}\}">d</figure-callout>}}^2{\mathrm{\&phi;}}^3}+\frac{\mathrm{\&beta;}(1-\mathrm{\&phi;})}{{\mathrm{\&phi;}}^3}\frac{\mathrm{\&rho;v}}{\mathrm{\&mu;d}}---\left(3\right)$

$\frac{1}{k_r}=\frac{\mathrm{\&alpha;}{(1-\mathrm{\&phi;})}^2}{{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="HDA0000147534340000062.png"\; state="\{\{state\}\}">d</figure-callout>}}^2{\mathrm{\&phi;}}^3}+\frac{\mathrm{\&beta;}(1-\mathrm{\&phi;})}{{\mathrm{\&phi;}}^3}\frac{{\mathrm{\&rho;\&phi;u}}_{\mathrm{<figure-callout\; id="2"\; label="ro"\; filenames="HDA0000147534340000062.png"\; state="\{\{state\}\}">ro</figure-callout>}}}{2\mathrm{\&mu;d}}---\left(4\right)$

In the formula: the v grinding fluid is in the speed of wheel face, v=φ (v _s-u _θ); D is the diameter of wheel face pore; u _RoIt is the radial velocity that grinding fluid gets into the emery wheel pore; α and β are characteristic coefficient, α=150, β=1.75

Boundary condition equation is:

As θ=θ ₀The time, h=0 (5)

dh/dθ＝(u _r0R)/u _θ0 (6)

In the formula: u _R0And u _{θ 0}For at θ=θ ₀Grinding fluid during the position radially and tangential velocity.

Grinding fluid through the effective discharge of grinding area is:

q _Effectively=hb φ u _θ(7)

The effective discharge rate of grinding fluid does

A kind of method that adopts the measurement mechanism measurement grinding area dynamic pressure of grinding fluid effective discharge rate and dynamic pressure, step is following:

1) lays down scraper plate, effective discharge separating plate and rubber baffle on the device, regulate the screw rod of both sides differential screw mechanism, make slide plate away from workpiece; The adjustment emery wheel, making the minimum clearance between emery wheel and the workpiece is 0, the aperture of workpiece is positioned at emery wheel and workpiece minimum clearance place, and the aperture center of workpiece and grinding wheel width central lines;

2) supply with grinding fluid, start emery wheel;

3) regulate the worktable 1mm that moves right, the force value of record piezoelectric pressure indicator this moment output;

4) repeating step 3,20～30mm until worktable has moved right;

5) adjust emery wheel again, making the minimum clearance between emery wheel and the workpiece is 0, and the aperture of workpiece is the minimum clearance place between emery wheel and workpiece, and the aperture center of workpiece and grinding wheel width central lines;

6) regulate worktable and be moved to the left 1mm, record force value at this moment;

7) repeating step 6, until worktable has been moved to the left 5～10mm, so far draw the pressure-plotting of grinding area along the x direction;

8) adjust emery wheel again, making the minimum clearance between emery wheel and the workpiece is 0, and the aperture of workpiece is positioned at emery wheel and workpiece minimum clearance place, regulates that the aperture center line aligns on the inboard face of emery wheel and the workpiece;

9) regulate worktable and drive the workpiece 1.5mm that moves forward, the force value of record this moment;

10) repeating step 9, move to the lateral surface of emery wheel up to the aperture of workpiece, draw the pressure-plotting of grinding area minimum clearance place along the grinding wheel width direction this moment;

11) change the parameter that influences the grinding area hydrodynamic pressure: the minimum clearance between speed of grinding wheel, emery wheel and the workpiece, the dynamic pressure of measuring grinding area under relevant parameter distributes, and confirms the influence of each parameter to it.

In the said step 11), grinding area hydrodynamic pressure equation is:

$\frac{\&PartialD;}{\&PartialD;x}(\frac{{\mathrm{<figure-callout\; id="3"\; label="H"\; filenames="HDA0000147534340000011.png,HDA0000147534340000042.png"\; state="\{\{state\}\}">H</figure-callout>}}^3}{12\mathrm{\&mu;}}\frac{\&PartialD;p}{\&PartialD;x}-\frac{H}{2}{v}_s)+\frac{\&PartialD;}{\&PartialD;y}\left(\frac{{\mathrm{<figure-callout\; id="3"\; label="H"\; filenames="HDA0000147534340000011.png,HDA0000147534340000042.png"\; state="\{\{state\}\}">H</figure-callout>}}^3}{12\mathrm{\&mu;}}\frac{\&PartialD;p}{\&PartialD;y}\right)=0---\left(9\right)$

Its boundary condition equation is:

$p{|}_{x=a}=0,-\frac{b}{2}\&le;y\&le;\frac{b}{2}---\left(10\right)$

p _|y＝±b/2＝0，α≤x≤c (11)

$\frac{\&PartialD;p}{\&PartialD;x}{|}_{x=c}={p|}_{x=c}=0,-\frac{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="HDA0000147534340000062.png"\; state="\{\{state\}\}">b</figure-callout>}}{2}\&le;y\&le;\frac{b}{2}---\left(12\right)$

In the formula: H is the thickness of grinding area grinding fluid between emery wheel and workpiece, and b is a grinding wheel width, and a is the length that grinding fluid gets into the grinding area inlet end, and c is the length of grinding area endpiece, and R is the radius of emery wheel.

$H=\frac{x^2}{2R}---\left(13\right)$

The beneficial effect of the utility model is: grinding fluid is integrated at the measurement mechanism of the hydrodynamic pressure of grinding area generation through effective discharge rate between emery wheel/workpiece and grinding fluid; It both the energy measurement grinding fluid through the effective discharge rate between emery wheel/workpiece; And the hydrodynamic pressure that causes of the grinding fluid of energy measurement grinding area, efficiency of measurement is high; The effective discharge separating plate near or leave emery wheel and adopt differential screw mechanism, through the fine motion adjustment of differential screw mechanism,, improved precision and the reliability measured to realize accurate separation to the grinding fluid effective discharge; The effective discharge separating plate is processed by organic glass, so that observe the mobility status of grinding area grinding fluid, has improved the reliability of measurement mechanism; The bottom of effective discharge separating plate one side has groove, and felt is arranged in groove, seals to stop the slit of effective discharge between effective discharge separating plate and workpiece when measuring to reveal, and has improved the precision of measuring; Feeder is connected on the workpiece, and rubber baffle is fixed on the slide plate of differential screw mechanism, prevents that the grinding fluid that overflows from the fluerics from sneaking into feeder and can stop it to be splashed to differential screw mechanism; Piezoelectric pressure indicator is fixed on interior, and the pressure of emery wheel workpiece grinding area grinding fluid is delivered on the piezoelectric pressure indicator through the aperture on the workpiece and then measures its dynamic pressure; In addition, differential screw mechanism, workpiece and feeder directly are fixed on the Grinder bench, and be easy for installation.Compared with prior art, the integrated degree of the utility model is high, and measuring accuracy is high, and convenient measurement is convenient to realize automatic control, has solved a difficult problem that does not have the integral measuring device at present, and is significant to commercial production.

Description of drawings

Fig. 1 experimental provision general assembly (GA) axonometric drawing;

Fig. 2 experimental provision general assembly (GA) vertical view;

The cut-open view of Fig. 3 workpiece and sensor assembling;

The upward view of Fig. 4 workpiece;

Fig. 5 feeder axonometric drawing;

The axonometric drawing of Fig. 6 feeder and workpiece assembling;

Fig. 7 differential screw mechanism axonometric drawing;

Fig. 8 effective discharge separating plate axonometric drawing;

Fig. 9 scraper shaft mapping;

Figure 10 experimental provision general assembly (GA) vertical view (removing scraper plate);

Figure 11 experimental provision general assembly (GA) front view;

Figure 12 experimental provision general assembly (GA) right view;

Figure 13 hydrodynamic force boundary condition figure;

Figure 14 measures grinding area hydrodynamic pressure synoptic diagram.

Wherein, 1-differential screw mechanism, 2-rubber baffle, 3-effective discharge separating plate, 4-workpiece; The 5-worktable, 6-emery wheel, 7-scraper plate, 8-feeder, 9-piezoelectric pressure indicator; The 10-base, 11-screw rod, 12-slide plate, 13-felt; The 14-angle bar, 15-exports electric wire, 16-charge amplifier, 17-computer.

Embodiment

Below in conjunction with accompanying drawing the utility model is done explanation.

By Fig. 1,2,3 visible, the measurement mechanism of grinding fluid effective discharge rate and dynamic pressure, it mainly is made up of differential screw mechanism 1, rubber baffle 2, effective discharge separating plate 3, workpiece 4, scraper plate 7, feeder 8 and piezoelectric pressure indicator 9; In order to measure the hydrodynamic pressure of grinding fluid effective discharge rate and grinding area, the width of workpiece 4 equates with grinding wheel width; Effective discharge separating plate 3 is fixed on the slide plate 12 of differential screw mechanism 1, by laterally moving of screw rod 11 control effective discharge separating plates 3 make its near or leave emery wheel 6; For prevent effective discharge through grinding area along emery wheel 6 circulating refluxs to the fluerics, this device has used a scraper plate 7, is fixed by bolts on the effective discharge separating plate 3; Feeder 8 usefulness holding screws are connected on the workpiece 4, and the grinding fluid through grinding area is along feeder 8 final inflows in the containers; Rubber baffle 2 is fixed on the slide plate 12 of differential screw mechanism 1, prevents to sneak in the feeder 8 and can stop on its screw rod that is splashed to differential screw mechanism 1 11 from the grinding fluid that overflow the fluerics; Piezoelectric pressure indicator 9 is fixed on workpiece 4 inside, and the pressure of emery wheel workpiece grinding area grinding fluid is delivered on the piezoelectric pressure indicator 9 through the aperture on the workpiece 4 and then measures its dynamic pressure; In addition, the differential screw mechanism 1 of this device, workpiece 4 and feeder 8 directly are fixed on the Grinder bench 5.

The used workpiece of this measurement mechanism is like Fig. 3, shown in 4.Fig. 3 is the full sectional view along workpiece 4 width centrelines; Fig. 4 is the upward view of workpiece 4.The left end of workpiece 4 has the hole and the fluting that cooperate with holding screw and links to each other with feeder 8; The right-hand member perforate of workpiece 4 match with piezoelectric pressure indicator 9 (Fig. 3); Wherein the top has the aperture of φ 0.5 * 3mm; Certain any hydrodynamic pressure is delivered on the piezoelectric pressure indicator 9 through this aperture in the grinding area; The output electric wire 15 of piezoelectric pressure indicator 9 lower ends links to each other with extraneous charge amplifier 16 through the groove of workpiece 4 bottoms, and the output signal is finally imported 17 li in computer, and is shown in figure 14.

Feeder 8 is as shown in Figure 5, and longitudinally direction of feed is collected the grinding fluid inconvenience, so feeder 8 is made the turning shape; The thin plate at feeder 8 tops is in order to prevent outside the grinding fluid that grinding area ejects is splashed to feeder 8; On the thin-walled of feeder 8 inlet ends, have along the slotted hole of short transverse and cooperate with holding screw.

Workpiece 4 is as shown in Figure 6 with being connected of feeder 8, and holding screw is screwed in the threaded hole of workpiece 4 left ends, along the fixing feeder 8 of workpiece 4 Widths.

Differential screw mechanism 1 is as shown in Figure 7, and it is made up of base 10, screw rod 11 and slide plate 12, and the helical pitch of screw rod 11 both sides screw threads is different, but the both sides thread rotary orientation is identical, and the helical pitch of A section screw thread is 1.25mm, and the helical pitch of B section screw thread is 1mm.The helical pitch of selecting receives the restriction of worktable 5 width, because of differential screw mechanism 1 will be fixed on the worktable 5, if the helical pitch of choosing is big; Under the identical situation of slide plate 12 strokes; Screw rod 11 will be elongated, and corresponding base length will become greatly, and fixing of whole differential screw mechanism 1 is just insecure.Slide plate 12 bottoms of moving are swallow-tail form, are installed in the dovetail groove of base 10, and it moves by screw rod 11 controls.The displacement s of slide plate 12 does

L wherein _A, l _BBe respectively the lead of screw of screw rod A section and B section,

It is the angle that screw rod turns over.Slide plate 12 strokes of this device design are 6mm.

Using differential screw mechanism 1, mainly is the function of utilizing its fine setting, and shown in the expression formula of above-mentioned slide plate 12 displacement s, screw rod 11 revolves and turns around, and slide plate 12 moves 0.25mm.In the both sides of workpiece 4 differential screw mechanism 1 is arranged all, as shown in Figure 2, through its fine setting, control effective discharge separating plate is near contact emery wheel 6, to realize the separation to the grinding fluid effective discharge.

When whole differential screw mechanism 1 is installed; Screw rod 11 is connected with slide plate 12; Let slide plate 12 screw the shaft shoulder place of screw rod 11 centres, insert in the base dovetail groove slide plate 12 bottoms then, moves it screw rod A section screw thread and whorl of base hole and begin to screw the place; Rotary screw 11 more at last makes screw rod 11 screw threads screw out slide plate 12 and screws in the whorl of base hole.Under the identical situation of slide plate 12 strokes, screw rod 11 length that can shorten design are installed like this, and then reduce the length of base 10, whole differential screw mechanism 1 better is fixed on the worktable 5.

Effective discharge separating plate 3 is like Fig. 1, shown in 8, and it is processed by organic glass, so that observe the mobility status of grinding area grinding fluid; The threaded hole that one side of effective discharge separating plate 3 has 3 certain depths is connected with slide plate 12, the scraper plate 7 of differential screw mechanism 1 respectively; The bottom of opposite side has groove; Felt 13 is arranged in groove, seals to stop the slit of effective discharge between effective discharge separating plate 3 and workpiece 4 when measuring to reveal.Be positioned at the screw rod 11 on the workpiece both sides differential screw mechanism 1 through adjusting, the effective discharge separating plate that makes both sides is near contact emery wheel 6, thereby isolates effective discharge.

Scraper plate 7 is as shown in Figure 9, and it is processed by elastomeric material, main effect be prevent effective discharge through grinding area along the emery wheel circulating reflux to the fluerics.When the effective discharge separating plate 3 of organic glass during fully near emery wheel 6, scraper plate 7 just can link together with effective discharge separating plate 3, and is as shown in Figure 1, and will control effective discharge separating plate 3 and leave emery wheel 6 time, then need unload lower scraping plate 7 earlier.The both sides of scraper plate 7 have elongated slot, use bolt again after when being connected with effective discharge separating plate 3, can vertically regulating its position.

Figure 10 has showed the position relation between effective discharge separating plate 3, workpiece 4 and the feeder 8, and it is on the basis of Fig. 2, to remove scraper plate 7 to obtain.As shown in the figure, the certain distance of workpiece 4 is stretched out in the left side of two effective discharge separating plates 3, can know in conjunction with Fig. 6, and the grinding fluid through grinding area all flows in the feeder 8, has realized the collection to effective discharge.In addition, the inlet end of feeder 8 wraps in the inside to effective discharge separating plate 3, but it can not hinder the adjusting (stroke of the effective discharge separating plate of this device design be 6mm) of effective discharge separating plate in travel range.

Rubber baffle 2; The one of which end directly is fixed by bolts on the slide plate 12; The other end is fixing shown in figure 11 with angle bar 14, and its effect is to prevent that sneaking into feeder from the grinding fluid that overflow the fluerics also can stop on its screw rod that is splashed to differential screw mechanism 1 11, and is shown in figure 12.

This device can be surveyed the effective discharge rate of grinding fluid earlier, surveys the grinding area hydrodynamic pressure again.

The step of measuring grinding fluid effective discharge rate is following:

1) according to shown in Figure 10, install, fix each parts of device, regulate the screw rod of differential screw mechanism, make the effective discharge separating plate away from workpiece;

2) supply with grinding fluid, start emery wheel, the gap between adjustment emery wheel workpiece is zero, and emery wheel is alignd with the workpiece both sides of the edge;

3) screw rod of adjusting both sides differential screw mechanism makes the effective discharge separating plate near the contact emery wheel;

4) the adjustment worktable makes the horizontal range H of emery wheel axis and effective discharge separating plate right side be 5～10mm, and shown in figure 10, the emery wheel axis is in the left side of effective discharge separating plate right side;

5) stop the emery wheel revolution and supply with, lay scraper plate 7, regulate its position, make it, use bolt again near the contact emery wheel with grinding fluid;

6) supply with grinding fluid, start emery wheel;

7) collect effective discharge from the feeder endpiece, acquisition time t, t are 5～20min;

8) measure the mass M of the grinding fluid of collecting, bring formula into

Wherein ρ is the density of grinding fluid, can obtain the effective discharge q that collects _Effectively

9) from the flowmeter of hydraulic system, directly read the delivery rate q of nozzle _Spray

10) q has been arranged _EffectivelyAnd q _Spray, can calculate the effective discharge rate of grinding fluid, its value is q _Effectively/ q _Spray

11) repeating step 7～10, draw three groups of effective discharge rates, get its mean value;

12) change the parameter influence effective discharge,, measure the effective discharge rate under relevant parameter, can study of the influence of each parameter it like the position of grinding wheel speed, nozzle flow, jet velocity and nozzle, angle etc.

The mathematical model of effective discharge rate is following:

$u_{\mathrm{\&theta;}}\frac{{\mathrm{du}}_{\mathrm{\&theta;}}}{\mathrm{d\&theta;}}-\frac{\mathrm{\&mu;R\&phi;}}{k_{\mathrm{\&theta;}}\mathrm{\&rho;}}(v_s-u_{\mathrm{\&theta;}})=0---\left(1\right)$

$\frac{u_{\mathrm{\&theta;}}^{2}h}{2R}\frac{d^{2}h}{{\mathrm{d\&theta;}}^2}-\frac{h^2}{R}{\left(\frac{d{u}_{\mathrm{\&theta;}}}{\mathrm{d\&theta;}}\right)}^2+\frac{{2u}_{\mathrm{\&theta;}}h}{R}\frac{\mathrm{dh}}{\mathrm{d\&theta;}}\frac{{\mathrm{du}}_{\mathrm{\&theta;}}}{\mathrm{d\&theta;}}+\frac{1}{2}(\frac{1}{k_r}-\frac{1}{k_{\mathrm{\&theta;}}})\frac{{\mathrm{\&mu;<figure-callout\; id="2"\; label="h"\; filenames="HDA0000147534340000062.png"\; state="\{\{state\}\}">h</figure-callout>}}^2}{\mathrm{\&rho;}}\frac{{\mathrm{\&phi;du}}_{\mathrm{\&theta;}}}{\mathrm{d\&theta;}}---\left(2\right)$

$+\frac{{\mathrm{\&mu;\&phi;u}}_{\mathrm{\&theta;}}}{{2k}_r\mathrm{\&rho;}}\frac{\mathrm{hdh}}{\mathrm{d\&theta;}}+\frac{{\mathrm{\&mu;<figure-callout\; id="2"\; label="h"\; filenames="HDA0000147534340000062.png"\; state="\{\{state\}\}">h</figure-callout>}}^2\mathrm{\&phi;}}{2\mathrm{\&rho;}}(v_s-u_{\mathrm{\&theta;}})\frac{d}{\mathrm{d\&theta;}}\left(\frac{1}{k_{\mathrm{\&theta;}}}\right)+u_{\mathrm{\&theta;}}^{2}h-\frac{\mathrm{pR}}{\mathrm{\&rho;}}=0$

In the formula: u _θBe the tangential velocity of grinding fluid at the emery wheel circumference; μ is the kinetic viscosity of grinding fluid; R is the radius of emery wheel; φ is the porosity of emery wheel; ρ is the density of grinding fluid; v _sIt is the peripheral speed of emery wheel; H is the degree of depth that grinding fluid penetrates into the wheel face pore; P is the hydrodynamic pressure of grinding fluid in grinding area; k _θAnd k _rFor grinding fluid at the tangential of wheel face and infiltration coefficient radially,

$\frac{1}{k_{\mathrm{\&theta;}}}=\frac{\mathrm{\&alpha;}{(1-\mathrm{\&phi;})}^2}{{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="HDA0000147534340000062.png"\; state="\{\{state\}\}">d</figure-callout>}}^2{\mathrm{\&phi;}}^3}+\frac{\mathrm{\&beta;}(1-\mathrm{\&phi;})}{{\mathrm{\&phi;}}^3}\frac{\mathrm{\&rho;v}}{\mathrm{\&mu;d}}---\left(3\right)$

$\frac{1}{k_r}=\frac{\mathrm{\&alpha;}{(1-\mathrm{\&phi;})}^2}{{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="HDA0000147534340000062.png"\; state="\{\{state\}\}">d</figure-callout>}}^2{\mathrm{\&phi;}}^3}+\frac{\mathrm{\&beta;}(1-\mathrm{\&phi;})}{{\mathrm{\&phi;}}^3}\frac{{\mathrm{\&rho;\&phi;<figure-callout\; id="2"\; label="u\; ro"\; filenames="HDA0000147534340000062.png"\; state="\{\{state\}\}">u</figure-callout>}}_{\mathrm{ro}}}{2\mathrm{\&mu;d}}---\left(4\right)$

In the formula: the v grinding fluid is in the speed of wheel face, v=φ (v _s-u _θ); D is the diameter of wheel face pore; u _RoIt is the radial velocity that grinding fluid gets into the emery wheel pore; α and β are characteristic coefficient, α=150, β=1.75.

Boundary condition equation is:

As θ=θ ₀The time, h=0 (5)

dh/dθ＝(u _r0R)/u _θ0 (6)

In the formula: u _R0And u _{θ 0}For at θ=θ ₀Grinding fluid during the position radially and tangential velocity.

Grinding fluid through the effective discharge of grinding area is:

q _Effectively=hb φ u _θ(7)

The effective discharge rate of grinding fluid does

Before measuring emery wheel workpiece grinding area hydrodynamic pressure, scraper plate 7, effective discharge separating plate 3 and the rubber baffle 2 of handle assembly all to lay down, so that the complete grinding area dynamic pressure of measuring distributes.A diameter is arranged at the workpiece top is the aperture of 0.5mm, hole depth 3mm, and the dynamic pressure of grinding area is delivered on the piezoelectric pressure indicator 9 through this aperture just, thereby measures its size, and Figure 14 is for measuring grinding area inner fluid dynamic pressure synoptic diagram.

The concrete steps of measuring the grinding area dynamic pressure are following:

1) lays down scraper plate 7, effective discharge separating plate 3 and rubber baffle 2 on the device, regulate the screw rod of both sides differential screw mechanism, make slide plate away from workpiece; The adjustment emery wheel, making the minimum clearance between emery wheel and the workpiece is 0, aperture is positioned at emery wheel and workpiece minimum clearance place, and the aperture center of workpiece and grinding wheel width central lines;

2) supply with grinding fluid, start emery wheel;

3) regulate the worktable 1mm that moves right, the force value of record sensor this moment output;

4) repeating step 3,20～30mm until worktable has moved right;

5) adjust emery wheel again, making the minimum clearance between emery wheel and the workpiece is 0, and aperture is the minimum clearance place between emery wheel and workpiece, and the aperture center of workpiece and grinding wheel width central lines;

6) regulate worktable and be moved to the left 1mm, record force value at this moment;

7) repeating step 6, until worktable has been moved to the left 5～10mm, so far can draw the pressure-plotting of grinding area along the x direction;

8) adjust emery wheel again, making the minimum clearance between emery wheel and the workpiece is 0, and aperture is positioned at emery wheel and workpiece minimum clearance place, regulates the inboard face of emery wheel and aligns with workpiece aperture center line;

9) regulate worktable and drive the workpiece 1.5mm that moves forward, the force value of record this moment;

10) repeating step 9, move to the edge of emery wheel lateral surface up to aperture, and can draw the pressure-plotting of grinding area minimum clearance place along the grinding wheel width direction this moment;

11) change the parameter influence grinding area hydrodynamic pressure, like the minimum clearance between speed of grinding wheel, emery wheel and the workpiece etc., the dynamic pressure distribution of measuring grinding area under relevant parameter can be studied the influence of each parameter to it.

Grinding area hydrodynamic pressure equation is:

$\frac{\&PartialD;}{\&PartialD;x}(\frac{{\mathrm{<figure-callout\; id="3"\; label="H"\; filenames="HDA0000147534340000011.png,HDA0000147534340000042.png"\; state="\{\{state\}\}">H</figure-callout>}}^3}{12\mathrm{\&mu;}}\frac{\&PartialD;p}{\&PartialD;x}-\frac{H}{2}{v}_s)+\frac{\&PartialD;}{\&PartialD;y}\left(\frac{{\mathrm{<figure-callout\; id="3"\; label="H"\; filenames="HDA0000147534340000011.png,HDA0000147534340000042.png"\; state="\{\{state\}\}">H</figure-callout>}}^3}{12\mathrm{\&mu;}}\frac{\&PartialD;p}{\&PartialD;y}\right)=0---\left(9\right)$

Its boundary condition equation is:

$p{|}_{x=a}=0,-\frac{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="HDA0000147534340000062.png"\; state="\{\{state\}\}">b</figure-callout>}}{2}\&le;y\&le;\frac{b}{2}---\left(10\right)$

p| _y＝±b/2＝0，α≤x≤c (11)

$\frac{\&PartialD;p}{\&PartialD;x}{|}_{x=c}={p|}_{x=c}=0,-\frac{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="HDA0000147534340000062.png"\; state="\{\{state\}\}">b</figure-callout>}}{2}\&le;y\&le;\frac{b}{2}---\left(12\right)$

In the formula: H is the thickness of grinding area grinding fluid between emery wheel and workpiece, and b is a grinding wheel width, and a is the length that grinding fluid gets into the grinding area inlet end, and c is the length of grinding area endpiece, and R is the radius of emery wheel.

$H=\frac{x^2}{2R}---\left(13\right)$

Claims (6)

1. the measurement mechanism of grinding fluid effective discharge rate and dynamic pressure is characterized in that it comprises mainly and being made up of differential screw mechanism, rubber baffle, effective discharge separating plate, workpiece, scraper plate, feeder and piezoelectric pressure indicator; Wherein, the width of the workpiece equates with grinding wheel width; The effective discharge separating plate is fixed on the slide plate of differential screw mechanism, by laterally moving of screw rod control effective discharge separating plate make its near or leave emery wheel; The position of on the effective discharge separating plate, matching with emery wheel is provided with the scraper plate that is connected, and feeder is connected on the workpiece, and rubber baffle is fixed on the slide plate of differential screw mechanism; Piezoelectric pressure indicator is fixed on interior, and the pressure of emery wheel workpiece grinding area grinding fluid is delivered on the piezoelectric pressure indicator through the aperture on the workpiece and then measures its dynamic pressure; In addition, differential screw mechanism, workpiece and feeder directly are fixed on the Grinder bench.

2. the measurement mechanism of grinding fluid effective discharge rate as claimed in claim 1 and dynamic pressure is characterized in that, the left end of said workpiece has the hole that cooperates with holding screw and has fluting to link to each other with feeder; The right-hand member perforate of workpiece matches with piezoelectric pressure indicator; Wherein have aperture in the top at workpiece; Certain any hydrodynamic pressure is delivered on the piezoelectric pressure indicator through this aperture in the grinding area; The output electric wire of piezoelectric pressure indicator lower end links to each other with extraneous charge amplifier through the groove of workpiece bottom, and the output signal is finally imported in the computer.

3. according to claim 1 or claim 2 grinding fluid effective discharge rate and the measurement mechanism of dynamic pressure is characterized in that said feeder is the turning shape; The feeder top is provided with thin plate; On the thin-walled of feeder inlet end, have along the slotted hole of short transverse and cooperate with holding screw, workpiece and feeder are screwed into through holding screw in the threaded hole of workpiece left end, along the fixing feeder of width of the workpiece direction.

4. the measurement mechanism of grinding fluid effective discharge rate as claimed in claim 1 and dynamic pressure; It is characterized in that; Said differential screw mechanism mainly is made up of base, screw rod and slide plate, and the helical pitch of screw rod both sides screw thread is different, but the both sides thread rotary orientation is identical; Wherein the helical pitch of A section screw thread is 1.25mm, and the helical pitch of B section screw thread is 1mm; The slide plate bottom is swallow-tail form, is installed in the dovetail groove of base, and it moves by screw rod control, and the displacement s of this differential screw mechanism slide plate does

L wherein _A, l _BBe respectively the lead of screw of screw rod A section and B section,

It is the angle that screw rod turns over.

5. the measurement mechanism of grinding fluid effective discharge rate as claimed in claim 1 and dynamic pressure; It is characterized in that; Said effective discharge separating plate is processed by organic glass; The threaded hole that one side of effective discharge separating plate has 3 certain depths is connected with slide plate, the scraper plate of differential screw mechanism respectively, and the bottom of opposite side has groove, and felt is arranged in groove.

6. the measurement mechanism of grinding fluid effective discharge rate as claimed in claim 1 and dynamic pressure; It is characterized in that; Said scraper plate is processed by elastomeric material, and the both sides of scraper plate have elongated slot, uses bolt again after when being connected with the effective discharge separating plate, can vertically regulating its position.

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