JPS63306820A - Tap provided with oil hole - Google Patents

Abstract

PURPOSE:To discharge cutting chips completely from an object to be cut by forming a projection having no cutter at the tip of chamfer cut-up portion, and making an injection port communicated with an oil hole and opened toward a groove at the projection. CONSTITUTION:A groove 4 is formed in perpendicular with lead angle (alpha) of a tap cutter 1 having a spiral line S, so as to form a leading side flank 2 and a following side flank 3. An oil hole 5 is made through the center of body from handle side endface 6 to the endface 7a at chamfer cut-up portion 7a provided with a chamfer cutter 7, and a female screw 9a is provided at the endface 8 side oil hole opening 9. Another projecting member 10 having no cutter is screwed into the female screw 9a. A direct hole 11 communicated with the oil hole 5 and an oblique injection hole 12 communicated with the direct hole 11 are formed through the projecting member 10, with the oblique injection hole 12 directing toward the groove 4. Consequently, oil is injected into the groove 4 so as to discharge cutting chips through a hole made in an object to be cut, the endface 8 and the bottom of groove 4a to the handle side thus enabling smooth boring.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a tap with nine oil holes, particularly suitable for through-hole machining, which forms a female thread on the inner periphery of a machined hole.

(Prior art) A conventional tap with an oil hole has a pick-up 1 as shown in Fig. 8.
A cutting blade arranged along the iJ(S) (with a thread or straight groove (4) formed in the axial direction for 11, and an oil hole (5) drilled in the axial center/tap) There is a stop Okawa and a through Okawa, and when drilling a through hole, fill the tip of the oil hole with filler αe, and make a groove (4) perpendicular to the oil hole (5) near the chamfered cut-up part (7a). A type with an open oil spout hole (ZZa) is usually used.

When machining a blind hole, a hole without filler αe is used at the tip of the oil hole, and the chips are discharged from the groove to the outside by the oil jetted from the tip of the oil hole.

(Problem to be Solved by the Invention) However, in through-hole machining, as explained in FIG. ) is opened in the groove (4), so the strength is weak, and in addition, the cut-up part 9 (7a) has a spout hole.
During cutting, compressive stress and torsional moment are applied as concentrated stress, which causes the tongue to break. In addition, the oil is ejected from the oil ejection hole (12a) E> perpendicular to the oil hole (5) and ejected onto the hole wall surface of the workpiece, and further towards the tip of the chamfering blade (7) and the thread forming cutting edge. 1) The oil that flows in the direction of the thread forming cutting edge discharges chips to the outside of the workpiece, and the oil that flows in the direction of the tip of the chamfered blade (7)
) to push the cutting chips toward the tip of the chamfered blade. There is a limit to the amount of oil that can be ejected, and if oil is ejected in two directions, the power to eject the chips will be halved, and cutting will continue until the chips are not completely ejected, so the cutting edge will be ejected. This traps unused chips, accelerates the wear of the cutting edge, does not cause chipping of the cutting edge, increases the amount of re-grinding allowance, and requires a large number of steps for re-grinding, shortening the tool's life.

(Tth Means for Solving the Problem) This invention has a sharp cutting edge arranged along the helical wire and a plurality of rt7'H fl#s formed in the longitudinal direction, and bored in the axis of the main body. A spout hole communicating with the oil hole opening toward the groove is provided, and a protrusion is formed at the end of the main body, that is, at the tip of the recut and recut portion (7a), so that the oil is directed toward the handle side. This relates to a tap with an oil hole that allows a jet of oil to flow.

(Function) Since the spout passage (2), ae, which is formed at the tip of the chamfered cut-up part (7a) and which communicates with the oil hole is provided in the protruding part,
The oil is ejected in one direction from the tip of the chamfered blade (7) toward the handle, and the ejection force is dispersed and the chips are completely discharged outside the stiffened material. Oil is ejected and fine chips are discharged even during reverse rotation, so chips are not trapped in the cutting blade due to reverse rotation, the tap can be removed smoothly, and there is no need to clean screw-sized pieces.

(Example) The tap of the present invention will be explained using an example. In Figure 1, when a groove (4) is formed perpendicular to the leading angle (α) of the tap cutting edge (1) of the helical 1fs (S), a leading flank (2) and a trailing flank (3) are formed. Ru. Formation (n
yc The cutting edge angle (β) shown in Figure 9 for each fluff flank is the same. The end surface (8) of the chamfered cut-up part (7a) where the oil hole (5) is located at the axis of the main body and the chamfered blade (7) is provided from the handle side end surface (6).
), and a female thread (9a) is provided in the oil hole opening (9) on the end face (8) side. As shown in FIG. 2(a), the protruding member αO formed separately from the main body has an oblique jet hole α2, that is, a jet passage, which communicates with the straight length (llη) and the straight length Qll. The female thread of the oil hole opening (
9a), screw the male screw αj of the protruding member QO into the oil hole (
5) and mold hole a are communicated. The oblique jet hole α2 has a groove (
4), so the oil flows out to the groove bottom (4a). As a method of attaching the protruding member, in addition to screwing as shown in the embodiment shown in Fig. 2 (a), the protruding member Qα is made of an elastic material as shown in Fig. 2 (b), and a convex portion α4 is formed and an oil hole is installed. A recess is formed in the opening (9) of (5), and the protrusion α4 of the protruding member αO is pushed into the recess and fitted. Alternatively, it is also possible to form a reverse taper that expands inward from the oil hole opening force, provide and attach a taper that matches the taper to the protruding member 4, and press the protruding member to the opening of the oil hole. Oil enters the straight length q of the protruding member CLO through the oil hole (5), and is further jetted into the groove (4) from the oblique jet hole CLI, removing chips accumulated in the groove (4) from the workpiece. Drain outward through the hole.

Furthermore, as shown in Fig. 3, a protruding member C having approximately the same diameter as the pilot hole is provided.
It is also possible to form an ejection groove αG that opens into the groove (4) through the straight length αη of the IG to serve as an ejection path. In this case, the oil gushing out from the end face (8) of the biting blade (7) to the groove bottom (4a)
The chips flow out and are ejected only from the handle side, discharging chips. When a T-groove is formed perpendicular to the cutting edge advance angle of the helical line as in this example, the cutting edge angles of the leading side flank and the trailing side flank are the same, which improves the balance of the cutting edge and reduces cutting edge wear due to cutting. The life of the O-cutting blade, which can be equalized, is also extended. It also becomes easier to re-grind the cutting edge.

Further, FIG. 4 shows an embodiment in which the present invention is applied to a tap in which the groove (4) is a straight groove parallel to the axis, unlike the above-mentioned embodiment.

Note that if the outside diameter of the tap is small or the cutting edge does not require re-grinding, the protruding member may be fixed in the oil hole with adhesive, braze, laser beam, etc., and the function can be sufficiently performed.

Further, the embodiments shown in FIGS. 5 to 7 show an embodiment in which the protruding member is not provided separately as in the above-described embodiments, but is provided integrally with the main body.

Figure 5 shows that a protrusion (10a) is integrally formed at the tip of the upper 9 part with a chamfer, an oil hole (5) is drilled in the shaft center, and a through hole (5a) is formed in the protrusion (10a) without a cutting edge. form.

Screw the oil stopper α into the tip of the protrusion (lOa). The protrusion (XOa) has a spout hole a that communicates with the oil hole 15).
G is formed, and the nozzle hole ◇e is located at the bottom of the groove (4) of the tap.
a) Facing to the side. Note that the outer diameter of the protrusion (lOa) is made slightly smaller than the diameter of the machined hole to avoid scratches on the surface of the machined hole.

This jet of oil is directed toward the tap groove (4), and the chamfering blade (7) completely discharges the chips coming out of the forming cutting blade (1) from the machined hole with oil. In the embodiment shown in FIG. 6, the ejection hole (b) of the protrusion (ioa) is formed obliquely, and the outer diameter of the protrusion is smaller than the diameter of the machined hole. Since the oil is ejected directly to the groove (4), chips can be easily discharged. Also, the oil stopper α is fixed in the through hole (5a). Figure 7 shows the oil hole (5) as a blind hole and a protruding part (LOA).
A center hole QI3 is provided at the tip.

(Effects of the Invention) As described above, the present invention forms a protrusion without a cutting edge at the tip of the chamfered upper part, and the protrusion has a jet hole that communicates with the oil hole and extends toward the groove. As a result, the chips are completely discharged from the hole of the workpiece.

This eliminates abnormal wear and chipping of the cutting blade due to chips being caught in the cutting blade, and the life of the cutting blade is extended. Nineteenth, the accuracy of screw sizes also improves. In addition, since there is no ejection hole in the upward part of the chamfer, there is no possibility of breakage at the upward part of the cut.Furthermore, even when reversing to remove the tap, small chips are discharged by the oil jet, unlike the conventional method. There is no chance that chips will get caught in the cutting edge when rotating in reverse and damage or break the tap. Also, there is no damage to the extent of machining screws during reverse rotation.

[Brief explanation of the drawing]

Figure 1 is a partially cutaway front view of an embodiment of the present invention;
(A is a sectional view of the protruding member in FIG. 1, (B) is a sectional view of another embodiment, FIG. 3 is a sectional view of another embodiment of the oil cap, and FIGS. 4 and 5 are sectional views of another embodiment of the oil cap. 6 and 7 are partial sectional views of still another embodiment, and FIG. 8 is a partially cutaway front view of another embodiment.
The front view and FIG. 9 are explanatory diagrams showing the cutting edge angle, (4 is a partial enlarged view of a general tap, (r:4 is an enlarged view of the main part, 1... Blade 2... Advance flank 3... Trailing flank 4... Groove 4a... Groove bottom 5... Oil Hole 6... ...Handle end face 7...Bitching blade 7a...Bitching cut-up portion 8...Bitching blade end face 9...Opening 9a. ...Female thread 10...Protruding member 11...Straight hole 12...Diagonal hole (spout path) 13...Thread 14...・Convex part 15...Filling metal 16...Gushing m<Gushing path) S...Tsurimaki line agent Patent attorney Jun Kawachi 2 Figure 4 Figure 5 Figure 6 Figure 9 T Rono

Claims (3)

[Claims] (1) An oil having a cutting edge arranged along a helical line, a plurality of grooves formed in the longitudinal direction, and an oil hole drilled in the axis of the main body and opening toward the grooves. The tap with a hole is characterized in that a protruding part without a cutting edge is formed at the tip of the chamfered upward part, and the protruding part is provided with an ejection hole that communicates with the oil hole and opens toward the groove. Tap with oil hole. (2) The tap with an oil hole according to claim 1, wherein the protruding portion is formed separately from the tap body and is attached to the opening at the tip of the chamfered upward portion of the oil hole. (3) The tap with an oil hole according to claim 1, wherein the protruding portion is formed integrally with the main body.