CN100462190C - Method for trimming drill chuck clamping jaw external thread - Google Patents

Abstract

A method for modifying the shape of external spiral thread on the clamping jaw for drill fixture features that a '4-corner 6-arc modifying method' if disclosed for respectively to modify the spiral surfaces at both sides and modify the curvature of spiral threads at the edges of tooth top and tooth bottom, so removing the excessive material which can generate interference with the engaged internal spiral thread.

Description

The correction method of drill chuck clamping jaw external thread

Technical field

The present invention relates to a kind of correction method of drill chuck clamping jaw external thread.

Background technology

Drill chuck is the critical piece of various drilling machines and manual electric drill, and the drill chuck product of China occupies the main in the world market share.Along with the scope of application of electric tool constantly enlarges, the demand of high-performance drill chuck is constantly increased, meet the requirements of under the prerequisite in precision, flexibility and outward appearance, to the most important performance of product--the requirement of clamping force and anti-impact force is more and more higher.Therefore, require drill chuck satisfying under the prerequisite of certain performance requirement, structure is simple as far as possible, and cost reduces.Present both at home and abroad drill chuck enterprise is all in the research that increases aspect drill chuck clamping force, the anti-impact force.Because the high-performance self-locking clamping chuck of drill bit has characteristics such as high accuracy, high technology content, high added value and high benefit, can adapt to electric tool carries out bore operation reliably under vibrations, impact occasion requirement; The widely used heavy spanner drill chuck of professional power tool has characteristics such as tight power is big, precision is accurate; Therefore, high-performance self-locking clamping chuck of drill bit and heavy spanner drill chuck demand are in continuous increase both at home and abroad in recent years, and relevant both at home and abroad enterprises and institutions also bring the research of this respect into schedule.

Rotation by conical sleeve during drill chuck work drives the flexible of 3 uniform jaws, and drill handle part mainly is to clamp drill bit shaft portion by tapered thread transmission self-locking.Sleeve has particularity with combining of jaw, both screw type differences, and promptly the internal thread on the sleeve is a taper thread, its lead angle is a variate; And the external screw thread on the jaw is a cylindrical thread, and its lead angle is a definite value.Therefore, the helix equation of the two is inconsistent, and the conical surface and bolt will be contacted by the Archimedes spiral of two different curvature in the cross section when screwing, and forms " interference effect " in embossed area.The tapered thread that is to say conical sleeve is the degree that freely screws can't accomplish to screw as cylindrical thread the time with the cylindrical thread of jaw.For addressing this problem, the method that the enterprise of China generally adopts is: (1) reduces the button (circle) that screws of taper thread as far as possible and counts the thickness of (2) attenuate jaw screw thread tooth.Do so only can solve and freely screw problem, that is to say that jaw can free stretching motion, but lost very precious properties of product: the contact area of faying face is greatly reduced, have only the very limited flank of tooth when screwing in contact, most of flank of tooth is in " unsettled " state.The problem of bringing is: (1) jaw elasticity is big, rigidity is low, and the clamping force of formation is not enough; (2) less contact surface descends the shear strength parameter index of screw thread tooth bound fraction, can not bear bigger impulsive force, is easy to generate the failure phenomenon of " collapsing tooth ".

Clamping force and anti-impact force are to influence China's drill chuck principal element of product specification and price in the international market, because the influence of these two indexs, the most of drill chuck of China can only be in the lower position of international market, and be subjected to the fastidious of international procurement merchant easily, economic benefit of enterprises is had a strong impact on, can only generate profit by increasing output, and increase the consumption indicators of the energy and resource thus.Through the man drill chuck of present domestic number manufacturing enterprise present situation on product is analyzed, find that revolve (knot) of jaw and mated pair thereof closes the basic factor that precision is above-mentioned two important indicators of influence.Solution screws precision problem must start with from theory analysis, seeks influence and screws accuracy factors, makes special cutter according to theoretical analysis result, when the jaw that processes can realize that jaw and sleeve screw, reaches maximum contact area between facing.Select to combine with the material of steel again, just can produce the high-quality high-end drill chuck product that is consistent with advanced level in the world, the breaks through foreign patent limitation is improved the meagre profits that enterprise faced such as domestic drill chuck and electric tool, energy consumption height, situation that raw materials consumption is big.

Summary of the invention

The correction method that the purpose of this invention is to provide a kind of drill chuck clamping jaw external thread, employing to the tooth form face of drill chuck clamping jaw external thread carry out the correction of the flank shape of bilateral helicoid and (or) crest, the correction of the flank shape of tooth bottom edge helix curvature, with clamping force and the impact resistance index that improves common drill chuck.

The technical solution used in the present invention is:

Drill chuck clamping jaw external thread bilateral helicoid is carried out correction of the flank shape, i.e. four jiaos of correction of the flank shape methods: so-called four jiaos of correction of the flank shape methods are exactly that the bilateral helicoid of jaw external thread projection can be fallen with four clipped corners that the drill chuck internal thread of sleeve screws interference, make that the interference of thread side did not take place screw thread when screw thread screwed; According to the interference generation area, every side helicoid equation of jaw thread is divided into three parts, but adopt mathematical measure to set up the surface equation of these three sections helicoid smooth connections, calculate ideal and screw actual spiral angle and the accurate functional relation of opening up between the angle in the scope, go out the part that will pare off when correction of the flank shape is handled according to this function calculation, and determine that on this basis the cutting face shape of cutting tool, the movement locus of planning cutting tool carry out the technical goal that accurate correction of the flank shape is handled with realization to helicoid; Perhaps drill chuck clamping jaw external thread crest face and tooth bottom edge helix curvature are carried out correction of the flank shape, i.e. six arc correction of the flank shape methods: so-called six arc correction of the flank shape methods are exactly that the middle part of drill chuck clamping jaw external thread crest face and tooth bottom surface and the part material removal between both sides are fallen, and make screw thread when screw thread screws that the interference at the bottom of crest and the tooth no longer take place; According to the interference generation area, the segmental arc that arc at the bottom of crest and the tooth is divided into three sections different curvature respectively, set up the new crest face and the cambered surface equation of tooth bottom surface smooth connection respectively, and determine that on this basis the cutting face shape of cutting tool, the movement locus of planning cutting tool carry out the technical goal that correction of the flank shape is handled with realization to drill chuck clamping jaw external thread crest face and tooth bottom surface.

Drill chuck clamping jaw external thread is carried out the correction of the flank shape of bilateral helicoid, and promptly four jiaos of correction of the flank shape methods are carried out correction of the flank shape to drill chuck clamping jaw external thread crest and tooth bottom edge helix curvature again simultaneously, i.e. six arc correction of the flank shape methods.

The beneficial effect that the present invention has is:

Drill chuck clamping jaw external thread is carried out correction of the flank shape, to excise that part of unnecessary material that when screwing, interferes on the jaw form of thread face exactly, jaw not only can freely be stretched but also can contact area as much as possible be arranged with internal thread with the inside tapered thread that screws mutually.Therefore, the part that is cut off should be able to accurately be controlled, and avoiding occurring too much influences bond strength, the very few problem of not eliminating interference again of excision because of excising.Carry out correction of the flank shape by double thread, when solution drill chuck internal thread of sleeve and jaw external thread screw, screw the little problem of area.The present invention carries out on the basis of labor in " interference effect " that influence is screwed, " four jiao of six arc " correction method is proposed, set up corresponding Mathematical Modeling, realize the correction of the flank shape of jaw screw thread at last by special process, when thoroughly solution drill chuck internal thread of sleeve and jaw external thread screw, screw the little problem of area.Handle by correction of the flank shape, common drill chuck anti-impact force and maximum clamping force are enhanced about more than once.

Description of drawings

Fig. 1 screws screw thread pair internal and external screw line in the scope of screwing to launch rear screw angle comparison diagram mutually; I, III place are meant that screw thread forms the zone of some contact; In the helical angle of I place jaw screw thread helical angle, interfere to occur in upper right and bottom left section greater than the sleeve taper thread; In the helical angle of III place jaw screw thread helical angle, interfere to occur in upper left and lower right-most portion less than bush whorl; II is meant that screw thread is in the zone of vacant state.

Fig. 2 is a helix interference pattern solution; (a) be meant not correction of the flank shape figure; (b) be meant the interference at the place of III shown in Fig. 1; (c) be meant the interference at the place of I shown in Fig. 1, dash area is an interference region.

Fig. 3 is the cylindrical thread schematic diagram.

Fig. 4 is four jiaos of correction of the flank shape methods; (a) figure has described the correction of the flank shape zone of four jiaos of correction of the flank shape methods, wherein 1 is meant screw thread; 2 are meant the correction of the flank shape zone; (b) after figure has described and has adopted four jiaos of correction of the flank shape methods, the projection of helicoid helix on middle diametric plane, wherein n ₁, n ₂, n ₃Be meant the projection of outward flange helix on middle diametric plane of three sections helicoids that the screw thread correction of the flank shape is later.

Fig. 5 is the diagram method and the solution of curvature interference; (a) be the interference at I place; (b) be the interference at III place, dash area is the interference region at the bottom of crest and the tooth among the figure; (c) be of the projection of the later crest edge camber line of six arc corrections of the flank shape in the bottom surface; h ₁, h ₂, h ₃Be the projection of crest edge three segmental arcs after practicing Buddhism or Taoism in the bottom surface; h ₄, h ₅, h ₆Be the projection of tooth feather edge three segmental arcs after practicing Buddhism or Taoism in the bottom surface.

The specific embodiment

One, four jiaos of correction of the flank shape methods:

The jaw of drill chuck is cylindrical thread (can't adopt tapered tread), and the intersection of its tooth form face and middle diametric plane is that helical angle is the helix of definite value, and the screw thread evolute of the taper thread of sleeve is a curve, and its helical angle is a variate.Two evolutes should overlap when requiring the screw thread pair transmission, otherwise just can not correctly screw, even interfere phenomenon easily.The screw thread pair internal and external screw line that screws is mutually launched and be placed in the coordinate system to compare, see shown in Figure 1ly, the zone that goes wrong in the time of can finding to screw: I, III are meant that screw thread forms the zone of some contact; II is meant that screw thread is in the zone of vacant state.The projection of helicoid on middle diametric plane seen shown in Figure 2, (b), (c) be depicted as the III that occurs interference when screwing on the helicoid, the particular location at I place.As seen from Figure 2, eliminate interference and just should start with, obtain the size of required sleeve in this zone and jaw helical angle from analyzing interference region.

Tapered tread and the interactional situation of cylindrical thread when screwing in order better to analyze and to obtain are at first set up the parametric equation of sleeve circular cone internal thread helical.A known circular cone, central axis are on the z axle, and conical point is set up coordinate system at origin of coordinates O.If A is a particle of conical surface, with A along with the element of cone at its place, upwards be the uniform rectilinear motion from conical point, this bus is crossed the axle of the summit of circular cone around circular cone on taper seat simultaneously, promptly, so just formed the internal thread of sleeve conical around the rotation of z axle.If bus begins to be rotated counterclockwise from the position that is projected in the x axle, the semiapex angle of circular cone is θ, and point-to-point speed is v ₁, rotational angular velocity is ω ₁, then the parametric equation of this helical is:

$\left\{\begin{array}{cc}x=l\sin \mathrm{\&theta;}\cos {\mathrm{\&omega;}}_{1}t& \\ y=l\sin \mathrm{\&theta;}\sin {\mathrm{\&omega;}}_{1}t& t\&GreaterEqual;\mathrm{0,0}<l\&le;r/\sin \mathrm{\&theta;}\\ z=l\cos \mathrm{\&theta;}& \end{array}\right.$ Equation (1)

In the formula, l is the distance of t moment A point to conical point, l=v ₁T.

Jaw cylinder external screw thread is analyzed, and is research object with complete cylinder helical plane, vertically places jaw, is the z axle with the central axis, and plane, circle place, bottom surface is the xoy plane, straight line l ₁, l ₂Select the straight line of the mutual orthogonal on the cylindrical outer surface, wherein l ₁Around l ₂Motion, i.e. l spin ₁On the one hand around l ₂Do constant speed and rotate, on the other hand again along l ₂Be the uniform rectilinear motion, at the volley l ₁Keep forever and l ₂Orthogonal is like this by l ₁The curved surface that is drawn is called right helicoid, i.e. cylinder helical plane.Get l ₂As coordinate z axle, and l ₁The direction of motion be z axle forward, l ₁The plane at place is the xoy plane, l ₁With l ₂Intersection point be origin of coordinates O, set up coordinate system.Establishing movement at the uniform velocity speed simultaneously is v ₂, the constant speed rotational angular velocity is ω ₂, and begin to y axle motion by the x axle, then can this cylinder helical plane, see shown in Figure 3.The parametric equation of this cylinder helical plane is:

$\left\{\begin{array}{cc}x=d\cos {\mathrm{\&omega;}}_{2}t& \\ y=d\sin {\mathrm{\&omega;}}_{2}t& t\&GreaterEqual;0,-\&infin;<d<+\&infin;\\ z=v_{2}t& \end{array}\right.$ Equation (2)

Wherein, d is t l constantly ₁Go up certain some distance that projects to origin of coordinates o on the xoy plane.

Screw thread above the jaw is the part of cylindrical thread, in drill chuck inside, when jaw and internal thread of sleeve screw, the jaw angle [alpha] that can tilt, be the conversion that is rotated, tilts of original coordinate system, according to the coordinate transform formula, the equation of the new helicoid after can tilting.

Above equation group is the basis, the requirement that helicoid equation after jaw tilts when screwing on it should be consistent with sleeve inner helicoid equation, obtain the size of the cylindrical thread both sides helical angle on each jaw, and set up Mathematical Modeling, theoretical foundation as four jiaos of correction of the flank shape methods, adopt four jiaos of correction of the flank shape methods then, see shown in Figure 4ly, double thread carries out correction of the flank shape.Four jiaos of correction of the flank shape methods are exactly that the bilateral helicoid of jaw thread protrusion can be fallen with four clipped corners that internal thread screws interference, promptly the helicoid in the correction of the flank shape zone of 2 indications among Fig. 4 is handled, made the interference that the thread side does not take place when screw thread screws.This needs again every side helicoid equation of jaw thread to be divided into three parts, but adopt mathematical measure to set up the surface equation of these three sections helicoid smooth connections, set up two the new helicoid equations corresponding with the both sides helicoid, calculate ideal thus and screw actual spiral angle and the accurate functional relation of opening up between the angle in the scope, go out the part that will pare off when correction of the flank shape is handled according to this function calculation, realizing quantitative correction of the flank shape, and determine the cutting face shape of cutting tool on this basis, the movement locus of planning cutting tool is to realize that helicoid is carried out the technical goal that accurate correction of the flank shape is handled.The later helicoid of correction of the flank shape in the helix projection on the middle diametric plane shown in (b) among Fig. 4, n wherein ₁, n ₂, n ₃Be meant the projection of outward flange helix on middle diametric plane of three sections helicoids that the screw thread correction of the flank shape is later, helicoid has obtained processing as can be seen, makes screw thread screw area and increases, and screws closely, has increased impact resistance.

Two, six arc correction of the flank shape methods

The edge helix curvature correction of the flank shape of jaw crest and tooth bottom surface, the normal curvature of jaw helix is a definite value, and the normal curvature of bush whorl is a variate, and the closer to the vertex of a cone, curvature is big more, and jaw will adapt to the variation of curvature equally, otherwise, can't normally screw.The edge helical of research screw thread is a research object with conical and cylindrical spiral promptly.Get equidistant conical, establishing pitch is P ₁, the circular cone semiapex angle is θ, the bottom surface radius is r, then bus is long is l=r/sin θ, high h=r.ctg θ, on the then same bus everywhere the intersection point of helix and bus be followed successively by to the distance (crest edge helix then be greatly directly, then is path at the bottom of the tooth) of axle: R ₁=(h-P ₁-v ₁T) tg θ, R ₂=(h-2P ₁-v ₁T) tg θ ... R _n=(h-nP ₁-v ₁T) tg θ, between difference be: P ₁Tg θ.Getting the bottom surface radius is R, and pitch is P ₂Cylindrical spiral, helix is projected as a circle when normally placing on the bottom surface, because jaw external thread combines with sleeve when screwing, only is concerned about the part of helical inclined outer side.The projection of this part in the bottom surface is that spacing is P when tilting to place ₂A series of semiellipses of sin λ, and parameter is that major semiaxis is that R, semi-minor axis are Rcos λ.Conical and cylindrical spiral are placed on comparison in the same coordinate system, and when screwing the relative position relation of sleeve and jaw, can get the curvature interference shown in (a) and (b) among Fig. 5, crest and tooth feather edge camber line are divided into the segmental arc of three sections differing heights, different curvature respectively as can be seen, so just need handle, i.e. six arc correction of the flank shape methods six sections arcs.So-called six arc correction of the flank shape methods are exactly that the middle part of crest face and tooth bottom surface and the part material removal between both sides are fallen, make interference at the bottom of crest and the tooth no longer takes place when screw thread screws, crest and tooth feather edge camber line are divided into the segmental arc of three sections different curvature respectively, see h among Fig. 5 (c) ₁, h ₂, h ₃, h ₄, h ₅, h ₆Shown in, set up the equation of each segmental arc, and by the relativeness between big footpath (path) spacing and the semiellipse spacing, obtain the equation of each segmental arc, and the movement locus of cutting face shape, planning cutting tool of determining cutting tool on this basis is to realize carrying out the technical goal that correction of the flank shape is handled at the bottom of crest and the tooth.Tapered tread is at the spiral of Archimedes that is projected as of bottom surface, can be approximated to be circular arc in the little segmental arc scope, crest face and tooth bottom edge helix that the curvature interference takes place are studied, with the center of circle, male screw bottom surface is initial point, with a jaw crest (at the bottom of the tooth) face edge helix back normal of projection camber line on the bottom surface is the y axle, crossing the vertical with it straight line of initial point is the x axle, set up coordinate system, see shown in Fig. 5, then crest and tooth feather edge helix are exactly following equation group in the projection equation of bottom surface during the curvature correction of the flank shape.

(1) crest face edge helix is in bottom surface projection equation

$\left\{\begin{array}{c}{x}^2+{(y-y_1)}^2=r_I^2\\ x^2+{(y-y_2)}^2=r_{\mathrm{II}}^2\\ x^2+{(y-y_3)}^2=r_{\mathrm{III}}^2\end{array}\right.$ Equation (3)

(2) tooth bottom edge helix is in bottom surface projection equation

$\left\{\begin{array}{c}{x}^2+{(y-y_1^{\&prime;})}^2=r_I^{\&prime;2}\\ x^2+{(y-y_2^{\&prime;})}^2=r_{\mathrm{II}}^{\&prime;2}\\ x^2+{(y-y_3^{\&prime;})}^2=r_{\mathrm{III}}^{\&prime;2}\end{array}\right.$ Equation (4)

Y in the formula ₁, y ₂, y ₃Three sections camber line h for crest face edge differing heights, different curvature ₁, h ₂, h ₃The position of the center of curvature on the y axle;

Three sections camber line h for tooth bottom edge differing heights, different curvature ₄, h ₅, h ₆The position of the center of curvature on the y axle; r _I, r _II, r _III,

Be h ₁, h ₂, h ₃, h ₄, h ₅, h ₆The radius of curvature of crest, tooth bottom edge helix everywhere.In the reality, crest segmental arc h ₁, h ₃Equation might be identical; Segmental arc h at the bottom of the tooth ₄, h ₆Equation also might be identical.

The later helicoid radius of curvature of jaw inclination should be consistent with the helicoid radius of curvature of sleeve when foundation screwed, continue to derive and calculate, set up Mathematical Modeling, calculate screw thread requirement to crest and tooth bottom surface helix curvature when screwing, calculate the size of radius of curvature to be processed, determine the equation of interference region inner vortex, change h on the helix ₁, h ₂, h ₃The curvature equation of each section makes in the scope of screwing, and all radius of curvature all meet and screw requirement.Fig. 5 (c) mean camber line h is seen in three sections new edge helix projections on middle diametric plane of crest after the correction of the flank shape ₁, h ₂, h ₃Shown in, correction of the flank shape with backteeth at the bottom of three sections new edge helix projections on middle diametric plane see h among Fig. 5 (c) ₄, h ₅, h ₆Shown in.

Four jiao of six arc correction of the flank shape

The contour surface of drill chuck clamping jaw external thread carries out the accurate correction of the flank shape of four jiao of six arc, and above-mentioned four jiaos of correction of the flank shape methods and six arc correction of the flank shape methods can realize the correction of the flank shape to drill chuck clamping jaw external thread.Simultaneously they are combined, can reach better effect from helical angle and two angle considerations of radius of curvature, just four jiao of six arc correction of the flank shape method.Specific implementation process is identical with above-mentioned four jiaos, six arc implementation processes, exactly the two is combined.

Implementing process of the present invention:

Buy traditional drill chuck, concrete technology realizes by cutting tool and grinding tool.According to the Mathematical Modeling of setting up, determine the shape in the cutting face of four kinds of cutting tools, be bilateral helicoid cutter, crest face cutter and tooth bottom surface cutter, cook up pairing four cutting tool paths, it is the movement locus of movement locus, crest face and the tooth bottom surface correction of the flank shape cutter of bilateral helicoid correction of the flank shape cutter, the screw thread that adopts cutter, grinding tool to carry out correction of the flank shape is availablely cut, is cut or grind off unnecessary threaded portion, accomplishes the shape that needs and gets final product.Screw thread after correction of the flank shape is handled, screwing with internal thread of sleeve can be tightr, eliminates interference.

Claims (1)

1. the correction method of a drill chuck clamping jaw external thread, it is characterized in that drill chuck clamping jaw external thread bilateral helicoid is carried out correction of the flank shape, i.e. four jiaos of correction of the flank shape methods: so-called four jiaos of correction of the flank shape methods are exactly that the bilateral helicoid of jaw external thread projection can be fallen with four clipped corners that the drill chuck internal thread of sleeve screws interference, make that the interference of thread side did not take place screw thread when screw thread screwed; According to the interference generation area, every side helicoid equation of jaw thread is divided into three parts, but adopt mathematical measure to set up the surface equation of these three sections helicoid smooth connections, calculate ideal and screw actual spiral angle and the accurate functional relation of opening up between the angle in the scope, go out the part that will pare off when correction of the flank shape is handled according to this function calculation, and determine that on this basis the cutting face shape of cutting tool, the movement locus of planning cutting tool carry out the technical goal that accurate correction of the flank shape is handled with realization to helicoid; Perhaps drill chuck clamping jaw external thread crest face and tooth bottom edge helix curvature are carried out correction of the flank shape, i.e. six arc correction of the flank shape methods: so-called six arc correction of the flank shape methods are exactly that the middle part of drill chuck clamping jaw external thread crest face and tooth bottom surface and the part material removal between both sides are fallen, and make screw thread when screw thread screws that the interference at the bottom of crest and the tooth no longer take place; According to the interference generation area, the segmental arc that arc at the bottom of crest and the tooth is divided into three sections different curvature respectively, set up the new crest face and the cambered surface equation of tooth bottom surface smooth connection respectively, and determine that on this basis the cutting face shape of cutting tool, the movement locus of planning cutting tool carry out the technical goal that correction of the flank shape is handled with realization to drill chuck clamping jaw external thread crest face and tooth bottom surface.

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