JPS58186527A - Tap - Google Patents

Abstract

PURPOSE:To use a tap holder with large grasping force and rigidity, by forming a relief angle to at least 1 deg. and arranging accuracy of a shank equally to or above a shank of an end mill of the same nominal diameter to decrease cutting torque in case of tapping a material difficult to cut. CONSTITUTION:A relief angle of a tapping thread is formed to at least 1 deg. in either case providing the relief angle 3 left with a margin width 1 or providing the angle 3 from an edge point. A shank of a tap is formed to a thick shape and accuracy of an end mill shank, in which, accuracy of a permissible difference out of roundness and cylindricity is increased, and a milling chuck with large grasping force and rigidity can be used for a tap holder.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an improvement in a tap for making internal threads, and the relief of the tap thread can be increased by leaving a margin width (11) of 1311 m from the cutting edge (Fig. 3C) or from the cutting edge. 7 degrees or more, and the tolerance of the shank diameter (D in q.) is 1 Il.
As shown in I, compared to the conventional lug shank diameter tolerance, l
/~l/, milling chuck (also known as machining domi holder or machining domi ν chuck) K11f
This is a tap designed to be used at different times.

The general shape of conventional taps consists of a threaded part forming an internal thread and a shank with four threaded parts, such as the first and second prongs, and there is no screw opening (see Fig. 3). A
), a margin width (11) with a relief angle (Fig. 3B), and a relief angle from the cutting edge (Fig. 3C). When used with a tap, it is held in an axially balanced tapping chuck or a tapping chuck with a built-in mechanism for radial movement, and a female thread is formed by twisting -F of the tap. The conventional method was to correct the discrepancy between the axial center of the tap and the axial center of the female screw by free-floating the screw, and then tap the screw.

In this way, in either case, the female thread is formed with the torsion -F of the tap, so from the moment the tapping begins, the tap should be drawn on both sides so that it advances along the torsional direction. Since it was important for the threaded surfaces of the tap to maintain contact and for the tap to maintain its self-propelling function, it was convenient that the tap screw thread had only a small amount of relief thread in order to maintain self-guiding properties. . The diameter of the shank is generally less than M6 and is equal to or thicker than the nominal diameter of the thread (see Figure C), and the diameter of the shank is smaller than M8 and is smaller than the root diameter of the thread. (Figure 1 C) may be normal,
The tolerance of the shank diameter is the first. , IIK, the conventional shank tolerance value was 7°.

The tap of this invention can be used for machining center or N0III.
It is intended to be used by attaching it to an I machine, and the workpiece material is
It targets difficult-to-cut materials such as Inconel 1 titanium alloy, stainless steel, and various fiber #I reinforced plastics. Therefore, the relief of the tap thread is 1111 (2+) with the margin width [ ] 1 in the direction of Figure 3, or M (31) from the cutting edge in Figure 3C; It shall be 7 degrees or higher in both cases.

The accuracy of the shank shall be equivalent to or higher than the shank of an end mill with the same nominal diameter (tolerance, roundness, cylindricity), and an example of the tolerance of the diameter -) is shown in Figure 1. The roundness and cylindricity are to be within the tolerance of 1I3. When machining or FiN C41 machines are used, the tool is moved to a fixed position WIKN, and the tape Ivf\ to which the workpiece is attached is moved. When tapping a screw using a tap on such a machine, if the table travel distance and the time required are equal to the pitch of 1 cod 1f rotation and the time required for that rotation, the workpiece will not be affected by the tap and the required time. Since female threads with the same pitch can be produced, the self-guidance of the tap is unnecessary, and even if the escape of the tap thread is increased, the pitch of the female thread will not be distorted. If the workpiece is made of difficult-to-cut materials, the cutting torque can be reduced, and if the cutting edge is slightly worn, the margin width part will immediately come into contact with the female thread and cause friction. Alternatively, this K generates heat, which softens the hardness of the tap V and reduces its sharpness, making it impossible to tap the screw.Also, welding to the thread flank can be avoided and the life of the tap can be extended. For example, when the workpiece material is a titanium alloy, the conditions of the tool clearance piece are important, and if the clearance angle is too small as in a conventional tap, welding will easily occur on the tap thread surface. Therefore, one of the features of the present invention is that the clearance angle of the screw thread can be increased without being restricted by the self-guidance of the tap as in conventional taps.

Next, let's talk about the shank. In machining centers or NO machines, the axial center of the tap and the axis of the pre-threaded hole of the workpiece are maintained to match with high precision, so the conventional floating method is used to hold the tap and make the pre-screw hole. Since there is no need to perform operations such as searching for and positioning the shank of the tap, see Figure 2! J3) or a convex en-Ft/V shank with a thick and precise shape and high accuracy in tolerance, roundness, and cylindricity. A milling chuck with high rigidity can be used. If the rigidity of the tap and holder can be increased in this way, tool pitting that occurs when the rigidity is low, such as stainless steel, can be prevented, and this can be an effective means of extending the life of the tap. An example of the tolerance of the effective shank diameter φ of this invention is vg
1, this is another feature of the present invention.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an example of a comparison of the shank diameter tolerance of the present invention and a conventional tap. Fig. 1 φ), r) Conventional tap, Ft,! J) + is a side view and both end views of the end mill, Fig. 3 μ) is a tap without a relief hook for the thread, -1 is a tap with a relief hook that measures the margin width, 0 is a tap from the cutting edge to the thread FIG. 1I is a side view and both end views of three types of taps with different diameters having shanks according to the present invention. (2+, t31... Agent for the patent applicant OnisG Co., Ltd. -, - □ Ikarizo λ

Claims (1)

[Claims] The tap screw thread relief is 7 degrees or more, and the shank has an accuracy (tolerance, roundness, cylindricality) that is equal to or higher than that of a machined shank of the same nominal diameter. Tap.