JPS6315091B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a cutter suitable for cutting, for example, a spiral groove provided on the outer periphery of an intermittent feed component.

[Background of the invention]

Conventionally, an intermittent feed mechanism has been known that uses a screw member provided with a spiral groove on the outer periphery of a shaft, and rotates the screw member by a predetermined angle to reciprocate a moving member engaged with the spiral groove by a predetermined distance. It is being

FIG. 1 is a schematic configuration diagram of such an intermittent feeding mechanism, in which 1 is a stepping motor, 2 is a bearing, 3 is a rotating connection member, 4 is a screw member, 5 is a guide bar,
6 is a moving member, 7 is a leaf spring, 8 is a tip, and 9 is a spiral groove.

A spiral groove 9 is formed on the outer periphery of the screw member 4, which is an intermittent feeding component, and one end of the screw member 4 is connected to the stepping motor 1 via the rotary connection member 3, and the other end is connected to the bearing 2. is supported by. The guide bar 5 is installed parallel to the screw member 4, and a movable member 6 is slidably fitted into the guide bar 5, and a pointed end 8 is provided at the lower end of the movable member 6 via a leaf spring 7. is slidably fitted into the spiral groove 9 of the screw member 4.

When it is desired to intermittently feed the movable member 6 at a predetermined pitch using this feeding mechanism, the stepping motor 1 is intermittently energized to intermittently rotate the screw member 4 forward, thereby moving the movable member 6 to the guide bar. 5 within a predetermined range.

By the way, the screw member 4, which is a conventional intermittent feed component used in this type of feed mechanism, is
As shown in the figure, the advance angle Θ of the spiral groove 9 is designed to be the same over the entire circumference, so by using a thread cutting lathe etc.
It can be processed relatively easily and with high precision. However, for example, the rotation angle of the screw member 4 is 0°, 45°, 90°, 135°, 180°, 225°, 270°, 315°.
When it is desired to intermittently stop the movement of the movable member 6 at 8 locations, due to variations in the rotation angle of the screw member 4 or discrepancies in the rotation control, the position of the movable member 6 will shift in proportion to the rotation angle, and the position of the movable member 6 may be shifted in proportion to the rotation angle of the screw member 4. There were problems with reliability as the engine could not be stopped at any point. In addition, as mentioned above, feed rate errors tend to occur due to deviations in the rotation control of the stepping motor 1, so in order to reduce this error, it is necessary to use a high precision, that is, an expensive stepping motor, or to use a spiral It is conceivable to use a special screw member with a modified advance angle Θ of the groove 9, but using an expensive stepping motor is a cost disadvantage, and it also requires machining a specially shaped spiral groove. for
There was also the problem that an NC lathe or special thread cutting lathe was required, resulting in an expensive part for intermittent feeding.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a cutting cutter that can easily and accurately process a special-shaped spiral groove with uneven advance angles, while eliminating the drawbacks of the prior art described above.

[Summary of the invention]

In order to achieve this object, the present invention provides a method for applying n-shaped fibers to the outer circumference of a cylindrical cutter body at regular intervals in the circumferential direction.
large-diameter cutting blades that are sequentially shifted by 1/n pitch in the axial direction and formed along the circumferential direction parallel to the rotation direction, and π/n in the circumferential direction with the adjacent large-diameter cutting blades.
Radian, axially shifted by 1/2n pitch,
The cutter is characterized by a small-diameter cutting blade formed along the circumferential direction parallel to the direction of rotation, and this cutter is given a rotary cutting motion in the same direction as the workpiece to cut the outer periphery of the workpiece. This forms a spiral groove with uneven advance angles.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below with reference to FIGS. 3 to 12.

FIG. 3 is a side view showing an embodiment of a cutting cutter according to the present invention, and FIG. 4 is a front view of the cutter. The cutter 10 consists of a cylindrical body 11 made of carbon steel or the like, and a number of cutting blades 13 made of cemented carbide or the like. , fixed precisely along the circumferential direction parallel to the direction of rotation. A mounting hole 12 with a keyway 12a is provided at the center of the cylindrical body 11, and the cutting edge 13 has a chevron-shaped cross section as shown in FIG. It's summery.

Each of the cutting edges 13 is provided in a plurality of consecutive rows in the circumferential direction, and the outer diameter of each cutting edge 13 is such that large diameter ones and small diameter ones are continuous alternately. , the adjacent cutting edges 13 are shifted by 2π/n radians in the circumferential direction of the cylinder 11 and by 1/n pitch in the axial direction of the cylinder 11. FIG. 6 is an explanatory view showing the state in which the cutter 10 is expanded in the axial direction. The 16 large and small cutting edges 13 that were misaligned are sequentially 1/1 in the axial direction.
The 16 cutting blades 13 are shifted by 16 pitches and are arranged in 12 rows a to l. Therefore, the first large-diameter cutting edge a ₁ in the first row and the second small-diameter cutting edge a ₂ are offset by 22.5 degrees in the circumferential direction and 1/16 pitch in the axial direction, and similarly. 16th small diameter cutting edge in the 1st row
A ₁₆ and the 1st large diameter cutting edge in the 2nd row, b ₁ , are also offset by 22.5 degrees in the circumferential direction and 1/16 pitch in the axial direction, and the 16th small diameter cutting edge in the 12th row is up to l ₁₆ . , and the following are similarly shifted.

7 to 9 are side views of cutting states using the cutter 10 described above, and 14 indicates a workpiece. The workpiece 14 is 1/1 of the cutter 10.
With a round bar having a diameter of 10, the workpiece 14 and cutter 10 are rotated together in a counterclockwise direction with a rotation ratio of 1:1.

Now, as shown in FIG. 8, the cutter 10 and the workpiece 14 are rotated in the direction of the arrow at an equal rotation ratio of 1:1, and the cutter 10 is sent a predetermined amount toward the center of the workpiece 14, that is, in the radial direction. Then, the contact locus between the cutting edge of the cutting blade 13 and the workpiece 14 becomes approximately a straight line, and the portion of the workpiece 14 shown by diagonal lines is cut by the large-diameter cutting blade _a1 . As a result, a V-shaped groove _A1 having the same cross-sectional shape as the cutting blade 13 is formed on the outer circumference of the workpiece 14.
A ₁ is parallel to a perpendicular line perpendicular to the axis of the workpiece 14. The cutter 10 and the workpiece 14 are
Since the diameters are different, the respective circumferential parts rotate together in the direction of the arrow at different circumferential speeds, so that the cutting edge _a2 with the smaller diameter starts a contact trajectory with the workpiece 14 next,
A new V-shaped groove A ₂ is formed in the workpiece ₁₄ at a position shifted by 1/16 pitch in the axial direction from the groove A ₁ formed by the cutting edge a 1 . moreover,
When the cutter 10 and workpiece 14 rotate, the ninth
As shown in the figure, the large-diameter cutting blade _a3 now starts a contact trajectory with the workpiece 14, and the workpiece 14 has a V-shaped groove A with the same depth as the aforementioned cutting blade _a1 . ₃ is formed. Therefore, the groove A ₃ formed by this cutting edge a ₃ is
1/16 pitch deviation in the axial direction from groove A ₂ due to cutting edge A ₂ ,
Groove A by cutting edge _A1 is shifted by 1/8 pitch in _{the 1-} axis direction. In addition, the depth of the groove A ₂ due to the small diameter cutting edge A ₂ is:
Since the depth of the grooves A ₁ and A ₃ formed by the large-diameter cutting edges A ₁ and A ₃ is shallow compared to the depth of the grooves A ₁ and A 3 , as shown in the figure,
The groove A ₂ formed by the cutting edge a ₂ chamfers the connecting portion between the grooves A ₁ and A ₃ formed by the groove A ₃ . Thereafter, by rotating the cutter 10 once, the workpiece 1
4, a total of 16 grooves having relatively long linear bottoms formed by large-diameter cutting blades and chamfering grooves formed by small-diameter cutting blades are arranged alternately in the circumferential direction, and in the axial direction. With a sequential shift of 1/16 pitch,
The row of blades of the cutter 10 (in this example, 12 blades a to l)
(column) with a threaded portion of the same length. Note that it is difficult to cut a groove of a desired depth with one contact trajectory, so in this case, cutter 10 is used.
The workpiece 14 and cutter 10 may be continuously rotated by reducing the amount of feed of each cutting blade 13 to reduce the amount of cutting per time.

FIG. 10 is a front view of the intermittent feed part processed by the cutter 10 described above, FIG. 11 is a right side view of the intermittent feed part shown in FIG. 10, and FIG.
The figure is an explanatory view showing the advance angle of the intermittent feeding part shown in FIG. 10, in which 15 is a shaft, 16 is a groove, 17 is a chamfer, and 18 is a spiral groove.

A large number of groove portions 16 having linear groove bottoms and chamfered portions 17 are alternately formed on the outer peripheral portion of the shaft 15 over a predetermined range. This groove portion 16 is
Parallel to the perpendicular Y that is orthogonal to the axis X of the shaft 15,
In other words, the lead angle Θ ₁ is zero, and there are eight pieces spaced at equal intervals in the circumferential direction, and shifted by 1/8 pitch in the axial direction.
Additionally, eight chamfered portions 17 are provided at equal intervals in the circumferential direction.
Although the chamfers 17 are shifted by 1/8 pitch in the axial direction, the groove depth of these chamfers 17 is shallower than that of the grooves 16, so as shown in FIG. It looks like the part has been chamfered. These groove portions 16 and chamfered portions 1
7 forms one spiral groove 18, and the chamfered portion 17 acts as a feeding portion for a moving member to be described later.

The spiral groove 18 of the intermittent feed component having such a structure has the pointed end 8 of the moving member 6 shown in FIG.
are slidably fitted. In the case of a feeding mechanism equipped with such an intermittent feeding component, the shaft 1
5, when the tip portions 8 slide within the chamfered portions 17, the chamfered portions 17
When the movable member 6 moves in a predetermined direction corresponding to the advance angle Θ ₂ and the tip 8 comes into the groove 16,
The power supply to the stepping motor 1 is cut off, and the movement of the moving member 6 is stopped. In this way, the movable member 6 is fed intermittently by being fed at the chamfered portion 17 and stopped at the groove portion 16, but the feeding operation of the movable member 6 is smooth due to the chamfered portion 17. As mentioned above, in the groove portion 16, the advance angle Θ ₁
is zero, so even if the rotation angle of the intermittent feeding component deviates somewhat, the stopping position of the moving member 6 is appropriate.
For this reason, the accuracy of the stepping motor is not required to be very high, and even inexpensive stepping motors can be used.

In addition, in the above embodiment, a case was described in which 12 rows of cutting blades 13 of different sizes, 16 in total, which were shifted at equal intervals of 22.5 degrees in the circumferential direction, were sequentially shifted by 1/16 pitch in the axial direction. The number and spacing of the cutting blades 13 according to the present invention are not limited to these, nor are the diameter ratio of the cutter 10 and the workpiece 14 or the rotation ratio during cutting to be limited to the above embodiments.

〔Effect of the invention〕

As explained above, according to the present invention, grooves having a linear bottom with a lead angle of zero are sequentially shifted by 1/n pitch on the outer periphery of the workpiece by a large-diameter cutting blade, and are Compared to machining a spiral groove for intermittent feed with uneven advance angles by chamfering the connection part of the square groove with a small-diameter cutting edge using an NC lathe or special thread cutting lathe, the machining time is longer. can be processed quickly and easily, and since the precision of the spiral groove is determined by the precision of each cutting edge of the cutter, it can be formed with high precision. If a member having such a spiral groove is used in an intermittent feed mechanism, etc., it is possible not only to increase the stopping position of the moving member without using a high-precision and expensive stepping motor, but also to smoothly move the moving member. can be sent to.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the feeding mechanism, Fig. 2 is an explanatory diagram showing the advance angle of a conventional intermittent feeding component, Figs. 3 to 12 show embodiments of the present invention, and Fig. A side view of the cutter according to the invention, FIG.
FIG. 5 is an enlarged sectional view of the cutting blade, FIG. 6 is an explanatory diagram showing the expanded state of the cutting blade, and FIGS. 7, 8, and 9 show the cutter of the present invention. 10th side view showing the cutting state of the workpiece by
The figure is a front view of the intermittent feed part machined by the cutter shown in Fig. 3, Fig. 11 is a right side view of the intermittent feed part shown in Fig. 10, and Fig. 12 is the same as Fig. 10. It is an explanatory view showing the lead angle of the shown part for intermittent feeding. 10... Cutter, 11... Cylindrical body, 13... Cutting blade, 14... Workpiece, 16... Groove, 17...
Chamfered portion, 18... spiral groove.

Claims (1)

[Claims] 1. In a spiral groove cutting cutter that rotates a workpiece and a cutter that cuts the workpiece in the same direction, and brings the cutter into contact with the workpiece from the radial direction to cut an intermittent feed groove. , the cutters are formed on the outer periphery of the cylindrical cutter main body in n pieces at equal intervals in the circumferential direction and sequentially shifted by 1/n pitch in the axial direction, parallel to the rotation direction and along the circumferential direction. A small-diameter cutting edge is formed along the circumferential direction parallel to the direction of rotation, and is sequentially offset from the adjacent large-diameter cutting edge by π/n radians in the circumferential direction and 1/2n pitch in the axial direction. A spiral groove cutting cutter characterized by having a blade.