JPH0655305A - Curved surface machining attachment for lathe - Google Patents

Abstract

PURPOSE:To machine a curved surface with any radius of curvature economically using a general-purpose lathe and inexpensive tools on the market. CONSTITUTION:A rotating shaft 2 is provided on a base 1 which is mounted on a tool post A, and a holder 3 is mounted detachably at the upper end of the shaft. When the rotating shaft 2 is rotated by operating a wheel 5a of a drive mechanism, the tool edge position of a throwaway tip 4 which is fitted to the holder 3 is moved on a circle with its center at the shaft 2. Here a cutting is made with a feed of tool edge movement on the circle. Thus a curved surface with a radius of curvature from the center of the shaft 2 to the tool edge of the tip can be machined using a general-purpose lathe and standard tools.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an attachment for curved surface processing which makes it possible to economically process a curved surface of an arbitrary radius on a work by using a general-purpose lathe and a commercially available inexpensive cutting tool.

[0002]

2. Description of the Related Art Turning of a curved surface of a stepped portion on the outer periphery of a workpiece and a curved surface of an outer peripheral groove is usually carried out by machining with a figure tool or by numerical control.

[0003]

Since the shape of the cutting edge is transferred to the work by machining with the figure tool, it can be processed by a general-purpose lathe, but a special cutting tool having a cutting edge matching the radius of the curved surface is required. And It is also necessary to prepare cutting tools of various sizes to cope with changes in the R radius. Further, since the size of the cutting tool is limited, a curved surface having a large R radius cannot be processed.

On the other hand, in the copying process, since the cutting tool is gradually moved in the radial direction of the work while sending it so that the movement locus of the cutting edge draws a curve, the cutting tool is a general-purpose product, but an expensive NC lathe is required. Machining becomes complicated with general-purpose lathes.

Therefore, in order to reduce the economic burden, the present invention uses a commercially available inexpensive cutting tool, for example, a standard polygonal throw-away tip, to form a curved surface having an R radius larger than the nose radius of the cutting tool on a general-purpose lathe. The purpose is to enable easy processing with.

[0006]

In order to achieve the above object, according to the present invention, a base fixed to a tool rest of a lathe, and a rotary shaft vertically assembled near the tip of the base,
Curved surface processing consisting of a holder that is detachably attached to the upper end of the rotating shaft, a cutting tool that protrudes the cutting edge toward the outer circumference of the holder and is mounted on the seat of the holder, and a drive mechanism for the rotating shaft that is assembled to the base. Provide attachments for.

[0007]

When the holder is rotated together with the rotary shaft by applying power to the rotary shaft, the cutting edge of the cutting tool attached to the holder moves to the center of the rotary shaft. The locus of this movement becomes a circle if the rotary shaft rotates at a fixed position. Therefore, if machining is performed with the cutting edge movement on this circle as the feed, the surface to be cut is from the axis of the rotary shaft to the cutting edge. The curved surface has a radius of R.

Incidentally, the change of the radius R of the processed curved surface is basically dealt with by exchanging the holder with a different size. If the amount of change in R radius is small, it is also possible to adjust the position of the positioning reference plane of the cutting tool provided on the holder.

[0009]

Embodiments of the attachment of the present invention will be described below with reference to the accompanying drawings.

As shown in FIGS. 1 to 4, a curved surface attachment 10 is a base 1 fixed to a tool rest A of a lathe.
A rotary shaft 2 provided on the tip side of the base, a holder 3 attached to the upper end of the shaft, a throw-away tip 4 mounted on the holder, and a drive mechanism 5 for the rotary shaft 1.

The upper corner at the tip of the base 1 is notched to avoid interference with the work. This base 1 is shown in FIG.
2 is provided with a vertical hole 1a, a horizontal hole 1b extending through the rear surface of the base part, and a plurality of bolt holes 1c (FIG. 2) penetrating the base part in the width direction. The bolt 6 (FIGS. 1 and 2) passed through is screwed into the tool rest.

The rotary shaft 2 is rotatably assembled in the vertical hole 1a. The shaft 2 is integrally provided with a socket 2a having a larger diameter than the hole 1a at the upper end to prevent the socket from coming out downward, and by screwing the foot 3a (FIG. 4) of the holder 3 into the socket, It is easy to attach and detach.

As shown in FIG. 5, the holder 3 has a male screw foot 3a and a seat portion 3b on which the throw-away tip is seated.
And a clamp screw 3c for the chip. Chip 4
Can be fixed by pressing the clamp piece from above or tightening with a flat head screw from above, but the clamp screw 3 shown in the figure that presses the chip against the positioning reference surface 3d with an eccentric shaft is used.
If it is c, as shown in FIG. 6, the position of the reference surface 3d can be adjusted by using the shim 7, and the blade edge position (R radius of the machined surface)
Fine adjustment of is allowed. The fine adjustment of the blade edge position can be performed by using a fine adjustment mechanism such as that used in a well-known micro unit.

As the throw-away tip 4, a negative type triangular tip is used here in consideration of economy.
The chip may be a parallelogram, a quadrangle, a round piece, or the like, and the use of a positive type chip is not limited.

The drive mechanism 5 rotates the handle 5a,
This rotative movement is transmitted to the rotary shaft 2 by a worm gear to rotate this shaft. That is, as shown in FIG. 3, a worm shaft 5c is provided at the tip of an input shaft 5b to which a handle 5a is attached, while a worm wheel 5d is attached to the lower end of the rotary shaft 2 and these are shown in FIGS. As described above, the rotating shaft 2 rotates rightward or leftward depending on the operating direction of the handle 5a. Reference numeral 5e is a bearing sleeve for enhancing the support stability of the input shaft 5b, and this sleeve is fixed to the base 1.

When it is necessary to greatly change the R radius of the machined surface, the holder 3 is replaced with a holder having a different size (R dimension in FIGS. 5 and 6).

The use of the exemplary attachment will now be described. FIG. 7 shows an example of processing the curved surface a on the outer peripheral step of the work W. As shown in the drawing, when the curved surface forming portion is tapered in advance so that interference with the holder 3 does not occur, the tool rest is operated to move the attachment 10 so that the tip of the tip 4 has a curved start end S. Move to where you come to. The tip of the tip may reach the point S by cutting the outer periphery of the small diameter part of the work while feeding it with a tool rest. In this case, the feed of the attachment by the tool rest is stopped when the point S is reached (the axis of the rotary shaft 2 is at the R center of the curved surface a at this time). Next, when the holder 3 is gradually rotated in the direction of the arrow in the drawing until the tip of the tip reaches the point E by operating the handle 5a, cutting is performed by the movement of the tip as a result, and the work area is cut. The (shaded portion) is scraped off to form the target curved surface a.

As shown in FIG. 8, even when the curved surface processing portion of the work W has a shape in which the cutting edge cannot be moved all the way to the S point at once, a small cut is made with the tool rest (the cutting edge is located on the axial center side of the work). Then, if the holder is rotated at each cutting position and the work area is divided into several times, the cutting can be advanced without any trouble. At this time, if the cutting blade feed direction is alternately reversed every time the divided work area is further cut, unnecessary rotation of the holder is eliminated.

The curved surface b of the circular arc groove on the outer periphery of the work shown in FIG.
Also, as in the case of FIG. 8, the work area can be cut without difficulty by cutting the work area several times, or by using a trapezoidal groove having a chain line to reduce the work area in advance and then using an attachment.

[0020]

As described above, if the attachment of the present invention is used, a curved surface having an arbitrary R radius can be easily processed with a commercially available inexpensive cutting tool without using a figure bite or an NC lathe, and the attachment itself is simple. It is economically advantageous because it can be made at low cost.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of an attachment of the present invention.

FIG. 2 is a side view of the above.

FIG. 3 is a partially cutaway plan view of the same as above.

FIG. 4 is a cross-sectional view taken along line XX of FIG.

FIG. 5 is a partially cutaway side view showing details of the holder.

FIG. 6 is a partially cutaway side view of a different size holder.

FIG. 7 is a diagram showing an example of curved surface processing.

FIG. 8 is a diagram showing another example of curved surface processing.

FIG. 9 is a diagram showing still another example of curved surface processing.

[Explanation of symbols]

 1 Base 1a Vertical Hole 1b Horizontal Hole 1c Bolt Hole 2 Rotating Shaft 2a Socket 3 Holder 3a Leg 3b Seat 3c Clamp Screw 3d Positioning Reference Surface 4 Throwaway Tip 5 Drive Mechanism 5a Handle 5b Input Shaft 5c Worm Shaft 5e Worm Wheel Sleeve 6 Bolt 7 Shim 10 Attachment for curved surface processing A Tool post W Work

Claims (1)

[Claims] 1. A base fixed to a tool post of a lathe, a rotary shaft vertically assembled near the tip of the base, a holder detachably attached to the upper end of the rotary shaft, and a blade tip protruding to the outer periphery of the holder. And a cutter attached to the seat of the holder, and a drive mechanism for the rotary shaft assembled to the base, and the holder is rotated together with the rotary shaft to move the blade edge of the cutter about the rotary shaft, A curved surface processing attachment for lathes, which is designed to machine a curved surface with an R radius from the axis to the cutting edge of the cutting tool.