CN1295903A - Other axle helicoidal surface grinding method and edge-grinding machine for cutting edge of twist drill - Google Patents

Abstract

The present invention relates to a sharpening method of metal cutting tool and a cutter grinding machine. It provides a method for sharpening cutting edge of twist bit, and is characterized by grinding main rear tool face of drill bit into Archimedian spiral surface using a straight line which and the axis of drill bit are mutually crossed to form some angle as axis to make the rear angle of external edge of main cutting edge and rear angle of chisel edge possess rational value. The drill point grinder using said invented method as principle is simple in structure, easy to operate, can implement good repeated edge-grinding accuracy.

Description

Its axle helicoidal surface of fluted drill cutting edge mill method and blade milling machine

The present invention relates to a kind of grinding method and cutter grinding machine of full genus cutting tool, especially relate to a kind of grinding method and drill point grinder of fluted drill cutting edge.

At present, widely used fluted drill in the industrial and mining enterprises, its grinding method is nothing more than two kinds: a kind of is by the free-hand sharpening on abrasive machine by rule of thumb of pincers worker.Another kind is to adopt mechanical sharpening, and mechanical sharpening method is also divided two kinds: the one, the main back knife face of drill bit is worn into taper seat, and claim taper seat mill method, the 2nd, wear into the main back knife face of drill bit with drill bit self axis and be the helicoid of axis, claim helicoid mill method.Above-mentioned free-hand by rule of thumb on abrasive machine the major defect of grinding method be to be difficult to guarantee that the relief angle of institute's abrasive drilling head and an angle are accurate and symmetrical, more can not guarantee the geometry of back knife face.As for traditional mechanical sharpening method, no matter be taper seat mill method or helicoid mill method, a common drawback is all arranged, promptly can not make the relief angle of main cutting edge outer rim place (the X1 point among Fig. 1) and chisel edge place (the X2 point among Fig. 1) be reasonable value simultaneously.And the main technical requirements of processing to drill bit of holing under the reasonable and different just operating modes of symmetry of drill bit main cutting edge relief angle and drift angle.

Purpose of the present invention just provides its axle helicoidal surface mill method of a kind of fluted drill cutting edge and is the drill sharpening equipment of principle with this method, the back knife face geometry of symmetry, rationally and the main cutting edge outer rim place's relief angle and the chisel edge place relief angle of symmetry so that obtain accurately.

The objective of the invention is to realize by following technical scheme:

The drill bit of this its axle helicoidal surface of fluted drill cutting edge mill method sharpening, geometry of its main back knife face be with drill axis O ₁O ₁The straight line of angled φ-β of intersecting is the Archimedes' helicoid of axes O O, and the distance of this two axis equals to bore the radius of core; The computational methods of relief angle are: calculating Chosen Point X method section respectively is the angle of spiral axp of axis with above-mentioned OO _NcAnd the angle axp between this Chosen Point basal plane Prx and the Pc ' plane _c' sum of the two is the tool nomal clearance a of this Chosen Point X _Nx, i.e. anx=axp _c'+axp _Nc, wherein: Pc ' is the parallel plane of drill bit midship section, and the distance on two planes is to bore core radius.The tool nomal clearance of described Chosen Point X is $\frac{\mathrm{do}}{2}\×\frac{\cos \mathrm{\φ}}{\mathrm{Rx}\cos \mathrm{\λtx}}+\frac{\mathrm{Tn}}{2\mathrm{\πr}},$ Wherein: do is for boring core diameter, and φ is the drill bit semiapex angle, and Rx is the radius of Chosen Point X, and Tn is a helical pitch, and r is the radius of curvature of Chosen Point X, and λ tx is the end face cutting edge inclination of Chosen Point X.

With its axle helicoidal surface mill method of fluted drill cutting edge is the blade milling machine of principle, comprise main shaft 7, abrasive machine 2, its improvements are that abrasive machine 2 is packed on the upper slide 1 that can slide along middle slide plate 17, and the inner surface of middle slide plate 17 lower curved grooves contacts with the outer surface of lower skateboard 18 top arc-shaped guide rails; Described main shaft 7 is loaded on the main shaft pedestal 9, and an end of main shaft 7 connects with lower slider 14; The outer surface of arc-shaped guide rail contacts with the inner surface of upper saddle 15 lower curved grooves on the lower slider 14; Clamping rod 3 is installed on the upper saddle 15.

Arc-shaped guide rail on the described lower skateboard 18 and the arc-shaped guide rail on the lower slider 14 are same axle center SS, and this axle center SS is the vertical line of main shaft 7 axis and axis of workpiece.

Be equipped with and tooth bar 12 meshed gears 6 at the middle part of described main shaft 7, and tooth bar 12 is installed on the slide plate 11, and the piston in slide plate 11 and the oil cylinder 5 connects.

On the described main shaft pedestal 9 roller 8 is housed also, the outer surface of the dove-tail form guide rail on the inner surface of main shaft pedestal 9 bottom grooves and the base 13 contacts.

Adopt this its axle helicoidal surface of fluted drill cutting edge mill method can obtain accurately and the back knife face geometry of symmetry, reasonable and symmetrical main cutting edge outer rim place's relief angle and chisel edge place relief angle, and accurate and symmetrical semiapex angle, can satisfy the specification requirement of processing of holing under the different operating modes to drill bit.And in this way have simple in structure, processing ease for the drill point grinder of principle, can realize repeating preferably the sharpening precision.

Below in conjunction with accompanying drawing the utility model is described in further detail:

Fig. 1 is a schematic diagram of the present invention;

Fig. 2 is Chosen Point X ₁Method profile P n-Pn profile;

Fig. 3 is a Chosen Point method section helix expanded view;

Fig. 4 is the structural representation of blade milling machine.

See also Fig. 1 to shown in Figure 3, OO is the axis of knife face helicoid behind the drill bit master, it and emery wheel axes O ₂O ₂On same plane P m, emery wheel working surface and OO axis angle are β, and β is the helical angle of back knife face helicoid.The parallel plane Pc ' of drill bit midship section Pc overlaps with Pm, and makes drill bit main cutting edge X ₁X ₂Overlap with helicoid generation line, like this, drill axis O ₁O ₁With the Pm plane parallel, the two distance is $\frac{\mathrm{do}}{2}$ (do is for boring core diameter), O ₁O ₁On Pm, be projected as O ₁' O ₁', O ₁' O ₁' equal φ-β with the OO axis angle.During grinding, emery wheel rotates to be main motion, and drill bit on the one hand is that axis rotates with OO, is that helical pitch moves along the OO axis and forms feed motion on the one hand with T.So just, the main back knife face of drill bit being worn into OO is the Archimedes' helicoid of axis.

Because Pc ' plane is by the OO axis, so perpendicular to main cutting edge X ₁X ₂Method profile P n-Pn in, form angle axp between the section of the vertical plane on Pc ' plane and back knife face _cIn this section, there is angle axp in ' (see figure 2) between Pc ' and the basal plane Prx in addition _c', these two jiaos of sums are the angle between cutting plane Psx and the knife face section, back just, is the tool nomal clearance anX of this Chosen Point X.

Can get following formula by Fig. 1, Fig. 2, Fig. 3: $\mathrm{tg}{{a_{x1P}}_c}^{\′}=\frac{\mathrm{do}}{2}\×\frac{\cos \mathrm{\φ}}{R{x}_1\cos \mathrm{\λt}{x}_1}------\left(1\right)$ In like manner: $\mathrm{tg}{{a_{x2P}}_c}^{\′}=\frac{\mathrm{do}}{2}\×\frac{\cos \mathrm{\φ}}{R{x}_2\cos \mathrm{\φ}}------\left(2\right)$ $\mathrm{tg}{a_{x1P}}_{\mathrm{nc}}=\frac{T\sin \mathrm{\β}}{2\mathrm{\πr}}=\frac{\mathrm{Tn}}{2\mathrm{\π}{r}_1}------\left(3\right)$ In like manner: $\mathrm{tg}{a_{x1P}}_{\mathrm{nc}}=\frac{T\sin \mathrm{\β}}{2\mathrm{\πr}}=\frac{\mathrm{Tn}}{2\mathrm{\π}{r}_2}------\left(4\right)$ Like this: $a_{n{X}_1}={{a_{x1P}}_c}^{\′}+{a_{X1P}}_{\mathrm{nc}}=\frac{\mathrm{do}}{2}\×\frac{\cos \mathrm{\Φ}}{R{x}_1\cos \mathrm{\λt}{x}_1}+\frac{\mathrm{Tn}}{2\mathrm{\π}{r}_1}---\left(5\right)$ ${a_{\mathrm{nX}}}_2={{a_{x2P}}_c}^{\′}+{a_{X1P}}_{\mathrm{nc}}=\frac{\mathrm{do}}{2}\×\frac{\cos \mathrm{\φ}}{R{x}_2\cos \mathrm{\φ}}+\frac{\mathrm{Tn}}{2\mathrm{\π}{r}_2}---\left(6\right)$ Obviously, ${{a_{\mathrm{XP}}}_c}^{\′}$ Be the function of drill bit semiapex angle φ and Chosen Point radius R x, and ${a_{\mathrm{XP}}}_{\mathrm{nc}}$ Be helical pitch T, helixangle and Chosen Point radius of curvature r _xFunction.Suitably select these parameters can grind rational drift angle and relief angle under the different operating modes.Now slightly lifting numerical example is listed in the table below:

Drift angle 2 φ	118°			136°			100°
The main sword outer rim relief angle (afx of place 1)										12°	10°	8°	10°	8°	6°	15°	12°	10°
The main sword chisel edge relief angle (afx of place 2)	36°			28.5°			42.8°

The structural representation of blade milling machine of the present invention such as Fig. 4.Abrasive machine 2 is contained on the upper slide 1, upper slide 1 can slide along the dove-tail form guide rail of middle slide plate 17, to adjust the radius of curvature r of back knife face, middle slide plate 17 can be along on the lower skateboard 18 being that the arc-shaped guide rail in the center of circle rotates with the SS axis, to adjust required helixangle, workpiece (by the drill bit of sharpening) is contained in clamping and holds in both hands in 3, clamping rod 3 is that benchmark is contained in the V-type groove of upper saddle 15 and locatees with its cylindrical, two alignment pins 4 along the circumference five equilibrium are arranged on the clamping rod 3, it plays axial location and calibration effect, alignment pin 4 serves as the location benchmark with the elongated slot on the slide block 16, and slide block 16 can be along the longitudinal movement with the control grinding tolerance.Upper saddle 15 can be along on the lower slider 14 being that the arc guide rail in the center of circle rotates with the SS axis, and to adjust φ-β angle, lower slider 14 can move along the dove-tail form guide rail that is contained in main shaft 7 ends, to adjust size $\frac{\mathrm{do}}{2}$ , this dove-tail form guide rail rotates with main shaft.

During work, emery wheel rotates to be main motion.Oil cylinder 5 and promotion slide plate 11 are along the guide rail straight reciprocating motion on the base 13, tooth bar 12 is housed on the slide plate 11, tooth bar 12 and sector gear 6 engagements that are contained on the main shaft 7, thereby driving main shaft rotates, realize that workpiece is the rotation of axes O O with the main-shaft axis, on the slide plate 11 master plate 10 is housed also simultaneously, roller 8 is housed on the main shaft pedestal 9, roller 8 is pressed on the side of master plate 10 by spring force, when master plate 10 was mobile with slide plate 11, master plate 10 just promoted roller 8, and roller 8 drives main shafts and moves along the dove-tail form guide rail on the base 13, main shaft also moves when rotating vertically like this, the feed motion when finishing grinding.Master plate 10 can be adjusted to different angles, so that helicoid obtains definite helical pitch T.

Claims (6)

1, a kind of its axle helicoidal surface of fluted drill cutting edge mill method, the geometry that it is characterized in that its main back knife face of drill bit of sharpening be with drill axis (O ₁O ₁) intersect that angled (straight line of φ-β) is the Archimedes' helicoid of axis (OO), and the distance of this two axis equals to bore the radius of core; The computational methods of relief angle are: calculate the angle of spiral that is axis with above-mentioned (OO) in any Chosen Point (X) method section respectively $\left({a_{\mathrm{XP}}}_{\mathrm{nc}}\right),$ And the angle between this Chosen Point basal plane (Prx) and the Pc ' plane $\left({{a_{\mathrm{XP}}}_c}^{\′}\right),$ Sum of the two is the tool nomal clearance (a of this Chosen Point (X) _Nx), promptly ${(a}_{\mathrm{nx}})=({{a_{\mathrm{XP}}}_c}^{\′}+{a_{\mathrm{XP}}}_{\mathrm{nc}}),$ Wherein: Pc ' is the parallel plane of drill bit midship section, and the distance on two planes is to bore core radius.

2,, it is characterized in that the tool nomal clearance (a of described Chosen Point (X) according to described a kind of its axle helicoidal surface of the fluted drill cutting edge mill method of claim l _Nx) be $\frac{\mathrm{do}}{2}\×\frac{\cos \mathrm{\φ}}{\mathrm{Rx}\cos \mathrm{\λtx}}+\frac{\mathrm{Tn}}{2\mathrm{\πr}},$ Wherein: do is for boring core diameter, and φ is the drill bit semiapex angle, and Rx is the radius of Chosen Point (X), and Tn is a helical pitch, and r is the radius of curvature of Chosen Point (X), and λ tx is the end face cutting edge inclination of Chosen Point X.

3, a kind of is the blade milling machine of principle with its axle helicoidal surface mill method of fluted drill cutting edge, comprise main shaft (7), abrasive machine (2), it is characterized in that described abrasive machine (2) is packed on the upper slide (1) that can slide along middle slide plate (17), the inner surface of middle slide plate (17) lower curved groove contacts with the outer surface of lower skateboard (18) top arc-shaped guide rail; Described main shaft (7) is loaded on the main shaft pedestal (9), and an end of main shaft (7) connects with lower slider (14); The outer surface that lower slider (14) is gone up arc-shaped guide rail contacts with the inner surface of upper saddle (15) lower curved groove; Clamping rod (3) is installed on the upper saddle (15).

4, a kind of blade milling machine according to claim 3, it is characterized in that arc-shaped guide rail and the arc-shaped guide rail on the lower slider (14) on the described lower skateboard (18) are same axle center (SS), and this axle center (SS) is the vertical line of main shaft (7) axis and axis of workpiece.

5, a kind of blade milling machine according to claim 3, be equipped with and tooth bar (12) meshed gears (6) at the middle part that it is characterized in that described main shaft (7), and tooth bar (12) is installed on the slide plate (11), and the interior piston of slide plate (11) and oil cylinder (5) connects.

6, a kind of blade milling machine according to claim 3 is characterized in that also being equipped with on the described main shaft pedestal (9) roller (8), and the outer surface of the dove-tail form guide rail on the inner surface of main shaft pedestal (9) bottom groove and the base (13) contacts.

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