JPH01193123A - Spiral groove forming method - Google Patents

Abstract

PURPOSE:To obtain a spiral groove which will not cause damage to the feed accuracy by forming a cutting edge of a cutter into two rows per lead in the same pitch as a spiral groove to be formed, and cutting a work while rotating the work and the cutter at a rotation ratio of 2:1. CONSTITUTION:A cutter 10 having a row of cutting edges r1, r2 is rotated in the same direction as a work 14 at a rotation ratio of 2:1, and the work 14 is cut from its radial direction. When the work 14 is cut by cutting edges a1-a6 of the row of cutting edge r1 for single screw thread, a groove part A1-A6 is formed. Next, when the work 14 is turned into the second turn, a groove part A1-A6 is cut again by cutting edges a'1-a'6 of the row of cutting edges r2 for double screw thread. Similarly, a groove part A7 or A12 of second row, a groove part H1 or H6 of-14th row are simultaneously formed respective ly. In this cutting method, waviness of a groove part 16 of the work 14 produced by cutting edges a1-a12 is cut by cutting edges a'1-a'12 having 180 deg. phase shift, and waviness U1 of a sine curve is cut by waviness U2 of a sine curve having opposite phase, and thus the locus of a middle point of both sine curves becomes a straight line.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for forming a spiral groove in the outer periphery of a bar by cutting.

[Conventional technology]

As a method for forming a spiral groove on the outer periphery of a workpiece (hereinafter referred to as a work), there are known methods such as cutting using a lathe, cutting using a thread milling machine, etc. In addition, as a method other than this, there is an invention disclosed in Japanese Patent Laid-Open No. 60-62413 filed by the present applicant, which proposes a method for manufacturing parts for intermittent feeding.

The invention related to this conventional proposal provides a method for manufacturing an intermediate feeding part having a spiral groove formed by connecting grooves having a linear bottom with a lead angle of zero on the outer periphery while shifting the grooves in sequence at a preset pitch. , on the outer periphery of the cutting tool, at equal intervals in the circumferential direction.
A large number of blades are provided along the circumferential direction parallel to the rotation direction and sequentially shifted by 1/n pitch in the axial direction,
By cutting a workpiece that rotates at a constant speed from the radial direction with each month of the cutting tool that rotates in the same direction as the workpiece at a rotation ratio of 1:1, a row of blades of the cutting tool is formed on the outer periphery of the workpiece. A spiral groove is formed with a threaded portion having the same length.

A specific example will be explained with reference to FIGS. 3 to 11.

Figure 4 shows a cutter (
Fig. 5 is a front view of the cutter;
The cutter IO has a mounting hole 12 with a key 4111 in the center, and has many cutting blades 13 on the outer periphery. As shown in FIG. 6, this cutting edge 13 has a chevron-shaped cross section, and the top thereof is slightly straight.

Each of the cutting blades 13 is a plurality of continuous rows of n cutting blades provided in the circumferential direction, and each adjacent cutting blade 13 has two cutting blades in the circumferential direction.
They are shifted by π/n radians and by 1/n pitch in the axial direction. FIG. 7 is an explanatory diagram showing a state in which the cutter 10 is expanded in the circumferential direction.
Eight cutting blades 13 are shifted at equal intervals of 1/8 pitch in the axial direction, and 12 rows of a-1 are provided, with these eight cutting blades 13 being one row. Therefore, the first cutting edge a in the first row and the second cutting edge a2 are offset by 45 degrees in the circumferential direction and 1/8 pitch in the axial direction, and similarly, the eighth cutting edge in the first row cutting blade a8 and the first cutting blade in the second row,
Also, 45 degrees in the circumferential direction, 1/8 pitch deviation in the axial direction, 12
The same deviation occurs up to the eighth cutting edge Net in the second row.

FIG. 8 and FIG. 9 are side views of the state of cutting using the cutter IO described above, and 14 indicates a workpiece. Work 1
4 is a round bar having a diameter of 1/10 of the cutter 10, and the workpiece 14 and the cutter 10 are both rotated counterclockwise at a rotation ratio of 1:1.

Now, as shown in FIG. 9, the cutter 10 and the workpiece 14 are rotated in the direction of the arrow at an equal rotation ratio of 1:1.
When the cutter 10 and the workpiece 14 move a predetermined distance toward the center of the workpiece 14, the contact locus between the cutter 10 and the workpiece 14 becomes a straight line, and the hatched portion of the workpiece 14 is cut. As a result, a single-shaped groove having the same cross-sectional shape as the cutting blade 13 is formed on the outer circumference of the workpiece 14, but this groove is parallel to a perpendicular line orthogonal to the axis of the workpiece 14. Since the cutter lO and the workpiece 14 are both rotating in the direction of the arrow at different circumferential speeds, the cutting edge a2 next comes into contact with the workpiece 14, and the workpiece 14 makes an angle of 135 degrees with the previously cut straight line. Linear contact trajectory (
(indicated by a two-dot chain line) to form a new single-character groove.

Since the cutting edges a and az are shifted by 1/8 pitch in the axial direction of the cutter 10, the new groove and the previous groove are shifted by 178 pitches in the axial direction of the workpiece 14. Thereafter, by rotating the cutting tool 10 once, eight pieces are placed on the outer circumference of the workpiece 14 at equal intervals in the circumferential direction and sequentially 1/2 in the axial direction.
The one-letter grooves shifted by 8 pitches are formed with threaded portions having the same length as the row of blades of the cutter 10. In addition, if it is not possible to form a groove of the desired depth with one contact cutting, reduce the feed amount of the cutter 10 to reduce the cutting amount of each cutting blade 13 at one time, and rotate the cutter 10 continuously. good.

FIG. 10 is a front view of the intermittent feed component manufactured by the method described above, and FIG. 11 is a right side view of the intermittent feed component, in which 15 is a shaft, 16 is a groove, and 17 is a spiral shape. The groove 18 is a feeding section.

A large number of grooves 16 having straight bottoms are formed on the outer circumference of the shaft 15 over the same length range as the row of blades of the cutter 10 . FIG. 12 is an explanatory diagram showing the advance angle of the intermittent feeding component. The groove portion 16 is parallel to the vertical &IY which is perpendicular to the axis 8 pieces equally spaced in the direction, and 1/8 in the axial direction
These grooves 16 are continuous in a pitch-shifted state, and as a result, one spiral groove 17 is formed by these grooves 16. A feed portion 18 having an advance angle and through which the moving member is fed is formed at each connection portion of the groove portion 16 cut and formed on the outer peripheral portion of the shaft 15 by the cutter 10.

The pointed end 8 of the moving member is slidably fitted into the spiral groove 17 of the intermittent feed component having such a configuration.

In a feeding mechanism equipped with such an intermittent feed component, as the intermittent feed component rotates, the pointed end 8
When the moving member 6 slides in the feeding portion 18 of each groove portion 16, the moving member 6 moves in accordance with the advance angle θ2 of the feeding portion 18.
moves in a predetermined direction and when the pointed end 8 reaches the groove 16, the power to the motor is cut off and the movement of the moving member 6 is stopped.

In this manner, the moving member is moved intermittently by moving at the feeding portion 18 and stopping at the groove portion 16.

[Problem to be solved by the invention]

By the way, in the method of manufacturing a part for intermittent feeding according to the above proposal, and in the method of forming a spiral groove using a lathe or milling machine, cutting is performed by rotating a cutter or a workpiece to cut the outer or inner circumference of the workpiece. When viewed microscopically in the grooves formed by the grooves, undulations as shown by the solid line in FIG. 13 occur every cycle.

For this reason, when the spiral groove cut as described above is used as a feeding groove, there is a possibility that the intended feeding accuracy may not be obtained due to this waviness.

This invention was made in view of such a technical background, and its purpose is to propose a method for forming a spiral groove that can provide a spiral groove that does not impair feeding accuracy due to waviness. It's about doing.

[Means to solve the problem]

In order to achieve the above object, the present invention forms cutting edges connected in a spiral manner at a preset pitch on the outer periphery of a cutter, and cuts the outer periphery of a workpiece rotating in the same direction as the cutter from the radial direction. In the method for forming a spiral groove in which a spiral groove is formed on the outer periphery of a workpiece, the cutting edge is set at the same pitch as the pitch of the spiral groove to be formed, and
Two strips are formed so that the same position can be cut with a different cutting blade every time the cutter rotates 0 degrees, and the workpiece and cutter are rotated at a rotation ratio of 2:1 to perform cutting.

[Effect]

According to the above means, since the groove position cut by - degree is cut again with the cutting blade having the opposite phase, the groove part itself is cut by 180 degrees.
This results in a undulation state in which the phase is shifted.

However, if you take the midpoint of the side surfaces of the cut groove, it will be straight or curved without undulations because both sides are cut in opposite phases. Therefore, when an engager or the like is engaged with the cut groove and a member connected to the engager is transferred, the center of the engager will coincide with the midpoint of the groove, and undulations of the groove will appear during transfer. There's nothing to do.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

Figures 1 to 3 are for explaining the present invention in detail. Figure 1 is a developed view showing the relationship between the groove formed in the workpiece and the cutting edge of the cutter, and Figure 2 is a developed view showing the relationship between the groove portion formed in the workpiece and the cutting edge of the cutter. FIG. 3 is an explanatory view showing the cutting state of the cutter, and FIG. 3 is an explanatory view showing the state of the engager engaging with the groove. In the drawings, the same reference numerals are given to constituent elements that are the same or can be considered to be the same as those of the conventional example, and redundant explanations will be omitted as appropriate.

This embodiment is intended to form six grooves 16 on the outer periphery of the workpiece 14, as shown in FIG. 13 is shifted by 30 degrees (2π/12 radians) and shifted by 1/6 bit in the axial direction, and there are two cutting edges 13 per l lead t.A two thread row of cutting edges rI similar to a two thread screw.
+r! It consists of That is, as shown in FIG. 1, in this embodiment, 12 cutting blades 13, which are equally spaced by 30 degrees in the circumferential direction per pitch p, are sequentially cut to 1/6 in the axial direction.
These 12 cutting blades 13 are shifted bit by bit, and the first cutting blade row indicated by a to h is divided into 1/2 rows.
Lead separation, similarly, 1 pitch p is equally spaced by 30 degrees in the circumferential direction and sequentially shifted by 1/6 pitch in the axial direction.
It is provided with a second cutting blade row r2 indicated by a' to h' with two cutting blades in one row. Therefore, the first cutting edge at and the second cutting edge a2 in the first row of the first thread are offset by 30 degrees in the circumferential direction and 1/6 bit in the axial direction, and the 12th cutting edge in the first row Blade a1□ and the first cutting blade b in the third row
1 is also shifted by 30 degrees in the circumferential direction and 1/6 bit in the axial direction.

In addition, the first cutting blades a and I of the second row are at positions rotated 180 degrees from the first cutting blade a of the first row of the first row, and are in the same position as the cutting blade a1 in the axial direction. are formed at the same position, and the second cutting edge row r2 has these cutting edges a and l as starting points.

When two cutting blade rows rl+rffi are formed as described above, when the cutter 10 is rotated 180 degrees, the second cutting blade row is placed in the place cut by the first cutting blade a of the first cutting blade row r1. The first cutting edge a1' of r2 is positioned and cutting is performed again.

Similarly, the cutting blades a2' are placed at the cutting edge a1 position, and the cutting blades a and 'a' are placed at the cutting edge a3 position, so that the cutting blades shifted by 180 degrees are used for re-cutting. Therefore, the cutting edge row rInr! As shown in FIG. 2, the cutter 10 having the
In other words, the cutter 1 rotates in the same direction with a rotation ratio of 2:1.
0 in contact with the workpiece 14 from the radial direction, when the workpiece 14 is first cut with the cutting edge a of the first cutting edge row r1, a groove A1 is formed in the workpiece 14, and the cutting edge A2 forms the groove A2, cutting blade a3 forms the groove A], cutting blade a4 forms the groove A4, and cutting blade a% forms the groove A.

However, grooves A are formed by the cutting edges a. When the workpiece 14 enters the second rotation, the groove A1 is cut by the cutting edge a.
, I cuts the groove A2 with the cutting edge a, l cuts the groove A4 with the cutting edge a, 41 cuts the groove AS with the cutting edge a,
The cutting blade aS' cuts the groove part A, and the cutting blade ah/ cuts the groove part A again. Similarly, the second row groove A,
to A+t, 3rd row grooves B1 to B6, 4th row grooves B, to B1□, ... 144th row groove H
3 to H6 are formed simultaneously. In the figure, p is the pitch of the cutting blade 13, and t is the lead of the cutting blade 13.

When cutting in this way, the undulation U of the groove 16 of the workpiece 14 caused by the cutting edge aIn at...a+t, which is typically shown by the solid line in FIG. Cutting edges a, ', a with a phase shift of 180 degrees
t'...a1! ’ is cut. In other words, with respect to the sine curve undulation U shown by the solid line, the cutting blade al'+a2'...al,' of the cutter 10 cuts with the sine curve undulation H2 of the opposite phase shown by the broken line. , if we take the locus M at the midpoint of both sin curves, it becomes a straight line. As shown in FIG. 3, this means that the cutting edge rows rIn'! have opposite phases. Cutting edges a,, a,...
When cutting with . It shows that the locus N is always located at the center of the groove width W of each part of the groove part 16.

In addition, in cutting each of the grooves 16, if it is not possible to cut the groove to the predetermined depth by cutting twice, the groove is cut multiple times to the predetermined depth. It is important to set the position to be cut twice. Furthermore, the shape of the groove 16, the feeding principle, the general shape of the cutter 10, etc., which are not particularly explained in the above description, are all formed the same as in the conventional example.

As described above, according to the above embodiment, by cutting the workpiece 14 with the cutter lO from the radial direction at a rotation speed of 1/2, the groove formation width t is the same as the width of the blade row of the cutter 10. , z, six grooves 16 are arranged in succession at a pitch of 1/6 per round, and it is possible to easily form a spiral groove for feeding in which the waviness of the grooves is canceled.

Furthermore, in the above embodiment, assuming that the number of cutting blades of the cutter 10 is n per round, two cutting blades sequentially shifted by 2/n pitch are provided per lead t, and 2 cutting blades are provided on the outer periphery of the workpiece 14 per round. / Although n grooves 16 are formed, n can be appropriately selected depending on the grooves to be formed in the workpiece 14 to be machined. Moreover, the cutting edge row 'I+' in the above embodiment! If it is continuously provided on the outer periphery of the cutter 10 and cut, it is also possible to form a single spiral groove 17 with a uniform advance angle on the outer periphery of the workpiece 14.

〔Effect of the invention〕

As is clear from the above description, according to the invention configured as described above, the cutting edge of the cutter is formed at the same pitch as the spiral groove to be formed and two grooves per lead, and the work piece is Since the cutter is rotated at a rotation ratio of 2:1 and the workpiece is cut from the radial direction, the same groove position is cut by the cutting blades whose phase is 180 degrees eccentrically, and the center position of the groove is cut. The locus can be made straight in plan view. As a result, when the groove portion is used as a feed groove, the undulations are reduced, and a spiral groove with extremely excellent feed accuracy can be formed. At this time, since it is only necessary to cut the workpiece from the radial direction, the workpiece can be manufactured easily and at low cost.

[Brief explanation of the drawing]

Figures 1 to 3 are for explaining the present invention in detail. Figure 1 is an explanatory diagram showing the cutting edge of the cutter and the spiral groove of the workpiece in an expanded state, and Figure 2 is an illustration of the workpiece and the workpiece. FIG. 3 is an explanatory diagram showing the state of the cutter in which the tip is held in place in the groove, and FIG.
The figures are for explaining the conventional example. Fig. 4 is a side view of the cutter, Fig. 5 is a front view of the cutter, Fig. 6 is an enlarged sectional view of the cutting blade, and Fig. 7 is an expanded state of the cutting blade. FIG. 8 and FIG. 9 are side views showing the cutting state of a workpiece by a cutter, FIG. 10 is a front view of an intermittent feed component manufactured by the manufacturing method of the conventional invention, and FIG. 11 is a right side view of the intermittent feed component shown in FIG. 10, FIG. 12 is an explanatory diagram showing the advance angle of the intermittent feed component shown in FIG. 10, and FIG. 13 is a diagram showing the conventional manufacturing method and the forming method of the present application. It is an explanatory view showing the state of the undulation of a groove part. 10... Cutter, 13... Cutting blade, 14...
...Work, 16...Groove, 17...
...Spiral groove, rl, rg... Cutting blade row. 1st FIl 2nd figure 37th figure 4th figure 5th figure 1st er1! J Figure 9

Claims (1)

[Claims] A spiral cutting blade is formed on the outer periphery of the cutter at a preset pitch, and the outer periphery of the workpiece rotating in the same direction as the cutter is cut from the radial direction to create a spiral shape on the outer periphery of the workpiece. In the method for forming a spiral groove for forming a groove, the cutting edge is arranged at the same pitch as the pitch of the spiral groove to be formed,
In addition, two grooves are formed per lead, and the cutting blades are arranged so that the same groove position can be cut by each groove with a 180 degree phase difference, and the rotation ratio of the workpiece and cutter is 2:1. A method for forming a spiral groove, which is characterized by rotating and cutting the groove.