JPH11333630A - Tap with oil hole - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform excellent lubrication and cooling of a cutting point by specifying a discharge position of oil mist and cutting liquid and resolve the breakage of a tap. SOLUTION: An oil hole 7 is formed in an axial part, a branch hole 8 communicated with the oil hole 7 is provided, and the tip of the branch hole 8 is opened in a chip discharge groove 6, and the branch hole 8 is arranged pointing to the front of a boundary part between a complete screw part 4 and a biting part 5. Further, the branch hole 8 is formed pointing to a direction orthogonal to an axis or pointing to a position slightly further in front than a direction orthogonal thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tap having an oil hole which is provided in an axis portion for cooling and lubricating a cutting portion, and the tip of the oil hole is opened in a chip discharge groove. Things.

[0002]

2. Description of the Related Art Conventionally, this type of tap with an oil hole is roughly classified into three types, a straight groove, a spiral groove, and a spiral point groove, depending on its groove shape. And those without branch holes. A straight groove type and a spiral point groove type are usually used for through-hole processing. Both types usually have a branch hole at the tip. These are applied to the hand tap and the point tap. FIGS. 5A and 5B
Discloses a tap having an oil hole of a type having a straight groove and a branch hole. In the tap with an oil hole shown in FIG. 5, an oil hole 53 is provided along the axis from the shank portion 51 to the vicinity of the biting portion 52 at the tip, and the chip is connected to the oil hole 53 and the chip is formed. A branch hole 55 is provided obliquely forward so as to open at the bottom of the discharge groove 54, and the cutting fluid is discharged obliquely forward through the oil hole 53 and the branch hole 55 (actually). Kaisho 60
-142022). Further, in consideration of the chip discharging property, there has also been proposed one in which a branch hole is provided obliquely rearward from the tip end of the oil hole as disclosed in, for example, Japanese Utility Model Laid-Open No. 63-110324. I have.

On the other hand, taps used for blind hole processing include a straight groove type and a spiral groove type, and in this case, usually, a branch hole is not provided at the tip. FIGS. 6A and 6B illustrate a tap having an oil hole of a type having a straight groove and no branch hole. In this type, the cutting fluid supplied through the oil hole 53 is discharged forward from the tip portion, and the discharged cutting fluid is discharged to the shank portion 51 side together with the chip through the chip discharge groove 54. It has become so. Note that this type of tap is applied to a hand tap. FIG.
(A) and (b) show a tap with an oil hole (spiral tap) having a spiral groove and no branch hole. In this tap with an oil hole, an oil hole 63 is provided along the axis from the shank portion 61 to the cutting edge portion 62, and the chip discharge groove 64 has a structure in which the discharge port is not opened. The cutting fluid discharged from the cutting edge portion 62 through the oil hole 63 is discharged to the shank portion 61 side together with the chip through a chip discharging groove 64 formed in a spiral shape.

[0004]

By the way, in the cutting using the tap with the oil hole as described above, conventionally,
So-called wet machining, in which cutting is performed while supplying a large amount of cutting fluid, has been the mainstream. Processing and mist processing of cutting with oil mist have attracted attention. However, because the conventional taps with oil holes are all based on wet processing, when these conventional taps with oil holes are used for semi-dry processing or mist processing, for example, in the case of a spiral tap, As shown by the arrow A in FIG. 7C, the mist discharged from the cutting edge portion 62 escapes through the chip discharge groove 64 without adhering to the cutting point, thereby lubricating the cutting point. In addition, there is a problem that the tap is broken due to excessive torque due to seizure due to poor cooling.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and the lubrication and cooling of a cutting point can be improved by defining a discharge position of an oil mist or a cutting fluid. It is an object of the present invention to provide a tap with an oil hole that can eliminate the problem.

[0006]

In order to achieve the above-mentioned object, a tap with an oil hole according to the present invention is provided with an oil hole at a shaft center and a branch hole communicating with the oil hole. And a tap with an oil hole formed by opening the tip of the branch hole into a chip discharge groove, wherein the branch hole is provided forward from the boundary between the completely threaded portion and the biting portion. It is a feature.

According to the present invention, the tip of the branch hole communicating with the oil hole provided in the shaft center is opened in the chip discharge groove,
In addition, since the branch hole is provided forward from the boundary between the completely threaded portion of the tap and the biting portion or from the boundary, oil mist or cutting oil escapes outside through the chip discharge groove. The oil mist and the like can be reliably attached to the cutting point, and it is possible to prevent a tap breakage accident due to lubrication or cooling failure from occurring.

In the present invention, the branch hole is preferably provided in a direction perpendicular to the axis of the tap with an oil hole or slightly forward from the direction perpendicular to the axis. More specifically, 80 ° to 9 ° with respect to the axis of the tap.
It is preferable to provide the branch holes so as to have an inclination of 0 °. By doing so, when this tap is used for blind hole processing, it is possible to prevent chips discharged from the cutting edge to the shank side through the chip discharge groove from entering the discharge hole of the branch hole. Can be. Therefore, it is possible to prevent an increase in tapping torque due to a decrease in the discharge amount of oil mist or cutting oil due to the intrusion of chips into the oil hole, and an inhibition of smooth flow of chips. This intrusion of chips into the branch hole is particularly remarkable when processing using an oil mist having a small mass, and is more effective when applied to semi-dry processing or mist processing.

In the present invention, when a diffusion effect of the cutting oil or oil mist discharged from the branch hole is required, it is preferable to form a chamfer at the discharge port of the branch hole.

[0010]

Next, a specific embodiment of a tap with an oil hole according to the present invention will be described with reference to the drawings.

FIG. 1 is an external view of a tap with an oil hole according to an embodiment of the present invention, (a), an end view (b), a sectional view (c), and a partially enlarged view (d) of (c). It is shown.

The tap 1 with an oil hole according to the present embodiment is applied to a spiral tap used for blind hole processing. In the tap 1 with an oil hole, the screw portion 2 is provided on the distal end side, the shank portion 3 is provided on the proximal end side, and the distal end side of the complete screw portion 4 in the screw portion 2 is toward the distal end. A bite portion (incomplete screw portion) 5 having a gradually decreasing diameter is formed. Further, a spiral (spiral) chip discharge groove 6 is provided in the screw portion 2, and chips generated by cutting work are discharged to the shank portion 3 through the chip discharge groove 6. ing.

An oil hole 7 is drilled from the base end to the vicinity of the boundary between the completely threaded portion 4 and the biting portion 5 at the axial center of the tap 1 with an oil hole. A branch hole 8 is formed from the front end portion toward the three chip discharge grooves 6. Each branch hole 8 is formed in a direction orthogonal to the oil hole 7, and is arranged such that a discharge port thereof faces a boundary between the completely threaded portion 4 and the biting portion 5. Note that a tapered chamfer 9 is formed at the discharge port of the branch hole 8 as shown in FIG.

When a female screw is formed in a work using the tap 1 with an oil hole having such a configuration, an oil mist is supplied through an oil hole 7, and the oil mist is supplied through a branch hole 8 to the complete screw portion 4. It is discharged into the chip discharge groove 6 toward the boundary with the biting portion 5. In this manner, the oil mist can be sufficiently supplied to the cutting point near the boundary between the completely threaded portion 4 and the biting portion 5, and the oil mist can be reliably attached to the cutting point. The points will be effectively lubricated and cooled. In addition, branch hole 8
Is formed in a direction perpendicular to the oil hole 7,
When chips generated by cutting are discharged through the chip discharge groove 6 to the shank portion 3 side, there is no possibility that the chips enter the branch hole 8 and the chips can be discharged smoothly. As a result, tap breakage due to excessive tapping torque due to seizure of the tap or chip clogging due to poor lubrication during cutting can be avoided.

Mist processing was performed using the tap 1 with an oil hole of the present embodiment and the conventional product shown in FIG. 7, and the tool life of each tool was compared. The test results are as follows. Here, in this mist processing, the air supply amount is 200 to 300 L / min with respect to the cutting fluid amount of 3 to 20 cc / min.

Work material: SS400, Cutting speed: 20m /
In the processing of a laminated plate of M20 × 2.5 in min, the conventional product was broken at a cutting length of 0.6 to 9.6 m, but the product of the present example was 44.8 m with no breakage and normal wear. Work material: SS400, Cutting speed: M at 30 m / min
In the processing of a single plate of 16 × 2.0, the conventional product was broken at a cutting length of 2.8 to 18.5 m.
m, no breakage and normal wear. Work material: SS400, Cutting speed: M at 35 m / min
In the processing of a laminated board of 24 × 3.0, the conventional product was broken at a cutting length of 0.6 to 1.7 m, but in the present embodiment product, it was broken.
At 4 m, there was no breakage and normal wear.

From the above test results, it can be seen that the product of this embodiment can greatly extend the tool life as compared with a conventional product (a spiral tap with an oil hole of a wet type) used for mist cutting.

In the present embodiment, the drilling angle of the branch hole 8 does not need to be limited to 90 °, and if it has an inclination angle of at least 80 ° to 90 ° forward with respect to the axis of the tap. The same operation and effect as described above can be obtained.

In this embodiment, the tapered chamfered portion 9 is formed at the discharge port of the branch hole 8, but the chamfered portion may be a round chamfer as shown in FIG. The portion 10 or a C-shaped chamfered portion (not shown) may be used, and an embodiment without a chamfered portion as shown in FIG. 2B is also possible. In addition, these chamfered parts are provided when aiming at the diffusion effect of oil mist (cutting oil).

In this embodiment, a spiral tap used mainly for blind hole processing has been described. However, the present invention is used for a hand tap used for both blind hole processing and through hole processing and for blind hole processing. It can be applied to point taps.

FIGS. 3A and 3B show an embodiment applied to a hand tap. FIG. 3A is an end view on the blade edge side, and FIG. 3B is an external view.

The tap 11 with an oil hole according to this embodiment includes a screw portion 12 and a shank portion 13.
A biting portion 15 having a gradually decreasing diameter toward the front end is formed on the front end side of the complete screw portion 14 in FIG. Further, on the outer periphery, three chip discharge grooves 16 are provided in the longitudinal direction of the tap from the tip of the screw portion 12 to the tip of the shank portion 13.

An oil hole 17 is drilled in the axial center of the tap 11 with an oil hole from the base end to the vicinity of the boundary between the completely threaded portion 4 and the biting portion 5. A branch hole 18 is formed from the front end of each of the three chips toward the three chip discharge grooves 16. Each branch hole 18 is formed so as to be slightly inclined forward with respect to the oil hole 17, and is arranged such that its discharge port faces the boundary between the complete screw portion 4 and the biting portion 5. I have. Here, the inclination angle of the branch hole 18 with respect to the oil hole 17 is preferably set in a range of 45 ° to 90 °.

According to the tap 11 with an oil hole of the present embodiment,
The oil mist is discharged into the chip discharge groove 16 through the branch hole 18 toward the boundary between the completely threaded portion 14 and the biting portion 15, so that the fully threaded portion 1
The oil mist can be sufficiently supplied to the cutting point near the boundary between the bit 4 and the biting portion 15, and the oil mist can be reliably attached to the cutting point. However, since the tap 11 with an oil hole according to the present embodiment is mainly used for processing a through hole, even if the inclination angle of the branch hole 18 with respect to the oil hole 17 is set in the range of 45 ° to 90 °, the chip Does not enter the branch hole 18. When this hand tap is used for blind hole machining, it is preferable to set the inclination angle to an angle near 90 ° in consideration of clogging of chips.

Also in this embodiment, in order to achieve the effect of diffusing the oil mist discharged from the branch hole 18, a tapered, round or C-shaped chamfered portion may be provided at the discharge port of the branch hole 18. it can.

FIGS. 4A and 4B show an embodiment applied to a point tap, in which FIG. 4A is an end view on the blade edge side, and FIG.

The tap 21 with an oil hole of this embodiment is basically the same as the tap 11 with an oil hole of the previous embodiment except for the configuration having the spiral point 22 at the tip of the chip discharge groove 16 ′. There is no difference. Therefore, the parts common to the previous embodiment are denoted by “′”
A detailed description thereof will be omitted by attaching a (dash) symbol.

In each of the above embodiments, mist processing or semi-dry processing has been described, but the tap with an oil hole according to the present invention can be expected to have the required effect even when applied to ordinary wet cutting. .

[Brief description of the drawings]

FIG. 1 is a view showing a tap with an oil hole according to one embodiment of the present invention, wherein (a) is an external view, (b) is an end view on the blade edge side, (c) is a cross-sectional view, (D) is a partial enlarged view of (c).

FIGS. 2A and 2B are diagrams showing a modification of the shape of the discharge port of the branch hole.

FIGS. 3A and 3B show an embodiment applied to a hand tap, in which FIG. 3A is an end view on the blade edge side, and FIG. 3B is an external view.

FIGS. 4A and 4B show an embodiment applied to a point tap, in which FIG. 4A is an end view on the blade edge side, and FIG. 4B is an external view.

FIG. 5 is a view showing a conventional tap with an oil hole of a type having a straight groove and a branch hole, in which (a) is a cutting edge side end view, and (b) is a cross-sectional view.

FIG. 6 is a view showing a conventional tap with an oil hole of a type that is a straight groove and does not have a branch hole, where (a) is an end view on the cutting edge side and (b) is a cross-sectional view.

7A and 7B are views showing a conventional spiral tap, in which FIG. 7A is an end view on the blade edge side, FIG. 7B is an external view, and FIG.
FIG. 4 is a view for explaining a situation in which mist escapes from a chip discharge groove.

[Explanation of symbols]

 1,11,21 Tap with oil hole 2,12,12 'Screw part 3,13,13' Shank part 4,14,14 'Fully threaded part 5,15,15' Biting part 6,16,16 ' Debris discharge groove 7, 17, 17 'Oil hole 8, 18, 18' Branch hole 9, 10 Chamfered part 22 Spiral point

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukiyuki Yamauchi 3-1-1 Ueno, Hirakata-shi, Osaka Komatsu Manufacturing Co., Ltd. Production Technology Development Center

Claims (4)

[Claims] 1. A tap with an oil hole, wherein an oil hole is provided in a shaft center portion, a branch hole communicating with the oil hole is provided, and a tip of the branch hole is opened in a chip discharge groove. A tap with an oil hole, wherein the branch hole is provided forward from a boundary between the completely threaded portion and the biting portion. 2. The tap with an oil hole according to claim 1, wherein the branch hole is provided in a direction orthogonal to an axis of the tap with an oil hole or slightly forward from a direction orthogonal to the axis. 3. The tap with an oil hole according to claim 1, wherein an oil mist or a small amount of liquid oil is supplied to the oil hole together with air. 4. The tap with an oil hole according to claim 1, wherein a chamfered portion is formed at a discharge port of the branch hole.