JPH0643003B2 - Oval processing machine - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to an elliptical machining machine for cutting the bottom surface of an elliptical hole in a workpiece.

2. Description of the Related Art Conventionally, when the bottom surface of an elliptical hole is machined flat, a milling machine or the like has been conventionally used and an end mill is used to proceed along the elliptical shape. Therefore, the processed product is XY
It is common to fix it on a table and process it over time using an NC machine.In rare cases, a lathe is used, the tool spindle that rotates the end mill is placed on the tool rest, and the workpiece attached to the lathe spindle is used. While slowly rotating, in synchronization with the rotation of the lathe spindle, the tool post was swung to gradually feed in the main direction to scrape the inner surface of the elliptic cylinder and at the same time scrape the bottom surface of the elliptic cylinder. All of them use end mills, and there is a problem when cutting the inner surface or the bottom of a deep ellipse due to the shape of the blade, and when cutting near the outer circumference of the ellipse, cut near the center. However, it is not efficient, and it requires complicated processing.In addition, complicated processing operations are required and chip discharge is poor, so the factory life is limited. It was a difficult processing method due to reasons such as

OBJECTS OF THE INVENTION Therefore, an object of the present invention is to provide a clever elliptical machining machine capable of machining an elliptical bottom surface in an efficient and stable state that satisfies all necessary motion conditions.

Therefore, according to the present invention, the main tool rest is arranged so as to hold the work piece while rotating the work piece by the lathe spindle and to face the work piece. This composite tool post holds at least one tool post in a state of being movable in the radial direction of the elliptical hole of the workpiece.

The tool rest supports the elliptical hole so that the bottom surface of the elliptical hole can be moved in the radial direction of the elliptical hole and can be swung so as to always face the cutting direction.

Further, the main tool post incorporates a gear mechanism that rotates in synchronization with the lathe spindle and a proportional conversion mechanism. This proportional conversion mechanism converts the rotation of the gear mechanism into a reciprocating linear motion by a cam / lever mechanism, and also changes the stroke of the reciprocating linear motion in proportion to the radial feed amount of the elliptical hole for bottom machining. To the turret for use. As a result, the bottom surface cutting tool first cuts the bottom surface of the elliptical hole while drawing a circular motion, but gradually changes to a spiral elliptical motion, and finally the final inner circumference of the elliptical hole. It approaches the elliptic motion of the surface.

In this way, the cutting tool for bottom machining moves gradually from the center to the outer periphery along the elliptical spiral locus on the bottom surface of the elliptical hole, and the cutting direction is always elliptical. While correcting the tangential direction of, elliptical bottom surface will be processed.

Configuration of the Invention FIGS. 1 to 4 show an elliptical machining machine 1 of the present invention.

This elliptical machining machine 1 is at a position facing the lathe spindle 2.
A main tool rest 3 is provided. This main turret 3 is a bed 4
It is provided on the slide guide surface 5 so as to be movable back and forth in the direction of the lathe spindle 2, and is driven forward or backward by a feed unit or the like (not shown).

The main tool rest 3 supports the elliptical feed slide 7 and the feed slide 8 in a movable state on the upper surface thereof by means of a slide guide surface 6 in a direction orthogonal to the lathe spindle 2. One of the elliptical feed slides 7 is also a fixed displacement slide 1 by a slide guide surface 9 in the same direction.
0, and the sliding guide surface 11 of this fixed displacement slide 10
Thus, the cutting feed slide 12 is movably supported in the direction of the lathe spindle 2. The other feed slide 8 is a slide guide surface 1 in a direction orthogonal to the lathe spindle 2.
3, the machining feed slide 14 is held in a retractable state.

The one cutting feed slide 12 rotatably supports a tool 17 for machining the inner peripheral surface by a support shaft 16 parallel to the lathe main shaft 2 by a tool rest 15 fixed to the upper surface thereof. Similarly, the processing feed slide 14 described above is also used.
Is a support shaft 19 parallel to the other tool post 18 and lathe spindle 2.
Thus, the bottom processing blade 20 is rotatably held.

The cutting feed slide 12 can be machine-feeded in the direction of the lathe spindle 2 by an axial cutting feed means provided between the cutting feed slide 12 and the fixed displacement slide 10, that is, a feed nut 21 and a feed screw 22. . The feed screw 22 is a feed servomotor 23 mounted on the fixed displacement slide 10, and an output shaft thereof and a timing belt wound around the feed screw 22.
It is adapted to be driven by the pulley 24. Further, the fixed displacement slide 10 constitutes a fixed displacement means together with the hydraulic cylinder 25. The fixed displacement slide 10 is provided with a pair of hydraulic cylinders 25 provided on the elliptical feed slide 7 and driven by the same for performing finishing after rough cutting. The driven member 26 on the side of the fixed displacement slide 10 can be displaced by a fixed amount.

The feed slide 8 serves as a radial cutting feed means.
The feed servomotor 27 attached to this, the feed nut 28 attached to the main tool rest 3, and the feed nut 28 inserted under the screw pair,
It can be moved along the slide guide surface 6 by a feed screw 29 driven by 7.

Further, below the main tool post 3, a gear mechanism for taking in synchronous rotation from the lathe main shaft 2 inside the case 30 is provided. That is, the rotation of the lathe main shaft 2 is given to the input shaft 31 by a winding transmission means or the like, and one gear 3 is provided at the input gear 32.
3 and 34 to the timing belt / pulley 36 of the intermediate shaft 35 and the mushroom-shaped cam 38 of the cam shaft 37.
It is also transmitted to the one mushroom-shaped cam 42.

One of the cams 38 is sandwiched by a pair of roller-like cam followers 43 on the diameter line of the cam shaft 37 to form a cam mechanism. The cam follower 43 is rotatably supported by a pin 45 with respect to a bracket 44 attached to the elliptical feed slide 7. The other cam 42 is also in contact with the pair of cam followers 46 on the diameter line of the cam shaft 41. Similarly, the cam follower 46 is rotatably supported by a pin 47 on the tip portion of a swing lever 48 having a substantially Y shape.

The swing lever 48 includes the cam 42, the piece 51, the bracket 52, the link 55, and the intermediate lever 5.
6, a pinion 58, and a rack 59 constitute a proportional conversion mechanism, which is swingably supported at the base end by a fulcrum shaft 49 parallel to the cam shaft 41 with respect to the main tool rest 3. Intermediate slide guide groove 5 in the longitudinal direction
0 holds the piece 51 in a movable state. The piece 51 is fitted in a sliding groove 53 of a bracket 52 attached to the feed slide 8 in a sliding pair, and is connected to an intermediate lever 56 by two pins 54 and a link 55. The intermediate lever 56 is supported by the intermediate shaft 57 together with the pinion 58 at the portion of the feed slide 8 in a non-rotating state. The pinion 58 meshes with a rack 59 attached to the lower surface of the processing feed slide 14.

Further, the intermediate shaft 57 is connected to the intermediate shaft 61 by a timing belt / pulley 60 as a transmission mechanism and a universal joint 69.
The gear 62 is engaged with the gear 63 of the support shaft 19.

On the other hand, the intermediate shaft 35 is similarly connected to the intermediate shaft 77 by a timing belt / pulley 64 and an expandable / contractible universal joint 70. The intermediate shaft 77 has a lever 68 fixed to the support shaft 16 by an eccentric pin 65, a connection mark 66, and a link 67 for connection.
Is connected to the tip of. These constitute the swing motion mechanism of the blade 17.

Operation of the Invention Next, the processing operation of the elliptical machining machine 1 will be described together with the operation of the invention.

First, the workpiece 71 is attached to the lathe spindle 2 in a centered state by a face plate or a chuck 72, faces the two blades 17 and 20, and rotates during processing. As shown in FIGS. 1 and 3 to 6, an elliptical hole 73 is formed in the workpiece 71, and a perfect circular hole 76 is formed in the bottom surface 75 thereof. And one knife 17
In order to process the inner peripheral surface 74 of the elliptical hole 73, is fed by the depth of the elliptical hole 73 along the generatrix direction.
The other blade 20 is fed in the direction away from the center, that is, in the radial direction of the elliptical hole 73, starting from the outer peripheral surface of the perfect circular hole 76, in order to machine the bottom surface 75 of the elliptical hole 73.

By the way, as shown in FIG. 5, one of the blades 17 has a stroke of a length L, which is half the difference between the short diameter and the long diameter, in order to process the inner peripheral surface 74 of the ellipse. In synchronism with the rotation of 71, the reciprocating forward / backward movement is periodically repeated. At the same time, the blade 17 supports the support shaft 16 in order to ensure a constant rake angle with respect to the machined surface, that is, the inner peripheral surface 74.
Performs rocking motion around. As a result, at the time of cutting the inner peripheral surface 74, the rake angle of the cutting tool 17 is always constant, and the best cutting condition can be secured for all the inner peripheral surfaces 74.

On the other hand, as shown in FIG. 6, the other blade 20 moves from the central portion to the outer portion gradually while drawing an elliptical spiral motion starting from the outer peripheral surface of the perfect circular hole 76. Finally, it approaches the ellipse of the elliptical hole 73. In such a cutting process, the direction of the cutting tool 20 with respect to the working direction does not always form a constant angle with respect to the center of the perfect circular hole 76, and is synchronized with the rotation of the work piece 71 and periodically. Must change to. For this reason, the support shaft 19 gives the blade 20 a necessary swinging motion.

The feed motion and the direction correction motion of the blades 17 and 20 are given as follows.

First, the machining feed motion for one of the blades 17 is given by the servo motor 23. That is, the rotation of the servo motor 23 is given to the feed screw 22 by the timing belt pulley 24. Due to the rotation of the feed screw 22, the feed nut 21 advances in the feed direction, that is, from the opening surface of the elliptical hole 73 to the depth direction, so that the blades 17 are sequentially fed.

On the other hand, the rotary motion of the workpiece 71, that is, the rotary motion of the lathe spindle 2 is transmitted to the gears 32, 33, 34 by the input shaft 31. Therefore, the cam 38, in synchronization with the rotational movement of the workpiece 71, gives the elliptical feed slide 7 a periodic reciprocating linear movement in the direction orthogonal to the lathe spindle 2, that is, in the radial direction of the elliptical hole 73. . Stroke L at this time
Corresponds to half the difference between the short diameter and the long diameter, as described above. When the blade 17 is on the major axis portion of the inner peripheral surface 74, it is at the position farthest from the machining center, and conversely, when it is at the minor axis position, it is at the position closest to the machining center. Moreover, the rotation of the input shaft 31 is
The eccentric pin 65 is given as an orbital motion of the eccentric pin 65 by the pulley 64 and the universal joint 70, and the eccentric pin 65, the connecting pin 66, the link 67, and the swing lever 6 are provided.
It is converted into a reciprocating swinging motion by the lever crank mechanism of 8 and transmitted to the support shaft 16. As a result, the blade 17
While maintaining a constant rake angle with respect to the inner peripheral surface 74 of the elliptical hole 73, the elliptical hole 73
It will be processed sequentially from the opening surface of the to the back.

In the meantime, the feed servo motor 27 gives a relative feed motion between the feed slide 8 and the machining feed slide 14, so that the other blade 20 has a perfect circular shape shown by an imaginary line in FIG. The hole 76 is moved from the outer peripheral position to a position corresponding to a circle having a short diameter. The movement amount D at this time is half the difference between the radius of the perfect circular hole 76 and the minor diameter of the elliptical hole 73.

Moreover, the cam 42 transmits the swinging motion to the intermediate lever 56 via the link 55 by giving the swinging motion to the swinging lever 48. As a result, the pinion 58
Via the rack 59 to the machining feed slide 14,
It is given as a reciprocating linear motion. This processing feed slide 14
Since the reciprocating linear motion of (1) is given to the other blade 20 as a reciprocating linear motion of the elliptical hole 73 in the radial direction,
By the combined movement of the linear movement from the center of the feed slide 8 to the outside and the reciprocating linear movement of the processing feed slide 14, a perfect elliptical circle 76 is started from the starting point and moves outward while drawing a spiral elliptical movement. I will do it.

Moreover, since the piece 51 is located near the fulcrum shaft 49 in the initial stage of machining, the swinging motion of the swinging lever 48 is small relative to the bracket 52 in the direction orthogonal thereto. As a result, the feed slide 8 gives the bottom surface 75 a cutting locus of circular motion close to the circular hole 76 in the initial stage of processing. However, when the feed slide 8 is fed by the servo motor 26 in the direction away from the machining center, the piece 51 moves in the direction away from the fulcrum shaft 49, so that the bracket 52 moves from the swing lever 48 to a large reciprocating straight line. You will get exercise. In this way, as the feed slide 8 is fed in the direction away from the processing center, the stroke of the reciprocating linear movement of the feed slide 8 gradually increases from 0 in proportion to the feed amount. The maximum stroke is at the end of machining, and corresponds to half the difference between the short diameter and the long diameter of the elliptical hole 73, that is, the stroke L. In this way, the other blade 20 gradually draws a spiral ellipse with a large ellipticity while drawing a perfect circular locus along the hole 76 in the initial stage of processing, and finally, within the elliptical hole 73. It approaches the ellipse of the peripheral surface 74.

Moreover, the rotation of the intermediate shaft 57 is caused by the timing belt / pulley 60, the universal joint 69, and the gear 6.
It is transmitted as a reciprocating rotary motion to the support shaft 19 by means of 2.63. Therefore, the blade 20 is, as shown in FIG.
It is directed in a fixed direction, that is, always in a tangential direction with respect to the traveling direction of the elliptical spiral. Therefore, the blade 20
Even if the bottom surface 75 moves along a machining path of an elliptical spiral, the direction of the machining direction is corrected so that the cutting state is always corrected to the best cutting state. Moreover, since the correction angle in this direction is given by the proportional conversion mechanism including the swing lever 48, the piece 51, and the bracket 52, as the ellipse of the machining locus increases,
The swing angle is gradually set to a large value. of course,
Since the feed motion and the correction motion of the orientation are always synchronized with the rotary motion of the lathe spindle 2, they are not displaced with respect to the elliptical hole 73 of the workpiece 71.

In this way, when the rough machining of the inner peripheral surface 74 is completed, the fixed displacement slide 10 is moved by the hydraulic cylinder 25 in the direction away from the machining center by a certain amount, so that the final finishing machining is performed. It is set in a state where it can be done, and the inner peripheral surface is finished in that state. Then, the processing of the inner peripheral surface 74 and the processing of the bottom surface 75 are set to be completed at substantially the same time from the viewpoint of processing efficiency.

Effects of the Invention According to the present invention, the following effects can be obtained.

First, the bottom surface cutting tool cuts the bottom surface while drawing a perfect circle in the initial stage of processing, and the stroke of the radial reciprocating linear motion is proportional to the radial feed amount. Since the size is increased and finally the inner peripheral surface of the elliptical hole is approached, a setup change or the like is not required during the processing, and one bottom surface can be continuously processed.

Secondly, the bottom surface cutting tool always continues cutting at a constant angle with respect to the cutting direction, so that the bottom surface can be machined as a beautifully finished surface.

Thirdly, since the radial feed of the ellipse for the bottom surface machining and the correction motion in the cutting direction are always performed in synchronization with the rotary motion of the workpiece, the motion and the ellipse of the machining target are performed. There is no misalignment with the hole and ideal cutting can be done efficiently under mechanical control.

[Brief description of drawings]

FIG. 1 is a plan view of an elliptical machining machine of the present invention, FIG. 2 is a vertical sectional view as seen from the rear surface of the main part, FIG. 3 is a vertical sectional view as seen from the side surface of the inner peripheral surface processed portion, and FIG. Is a vertical cross-sectional view as seen from the side surface of the bottom surface processed portion, and FIGS. 5 and 6 are explanatory views of an elliptical hole to be processed. 1 ... Elliptical machining machine, 2 ... Lathe spindle, 3 ... Main turret, 7 ... Elliptical feed slide, 8 ... Feed slide, 1
0: Fixed displacement slide, 12: Cutting feed slide,
14 ... Machining feed slide, 15, 18 ... Turret, 1
7, 20 ... Blade, 21, 28 ... Feed nut, 22,
29 ... Feed screw, 23, 27 ... Feed servo motor, 25 ... Hydraulic cylinder, 26 ... Following member, 32,
33, 34, 39, 40, 62, 63 ... Gears, 37,
41 ... Cam shaft, 38,42 ... Cam, 43,46 ...
Cam followers, 44, 52 ... Brackets, 48 ... Swing levers, 49 ... Support shafts, 50 ... Sliding guide grooves, 51
...... Pieces, 53 …… Sliding grooves, 55 …… Links, 56 …… Intermediate levers, 58 …… Pinions, 59 …… Racks, 65…
... eccentric pin, 66 ... connecting pin, 67 ... connecting link, 68 ... lever, 71 ... workpiece, 73 ... elliptical hole, 74 ... inner peripheral surface, 75 ... bottom surface.

Claims (2)

[Claims] 1. A diameter of an elliptical hole of a work piece is provided by arranging a main tool post facing a lathe spindle that holds a work piece while rotating the work piece, and feeding a tool post for bottom surface machining to the main tool post by a slide. Provided movably in the direction, rotatably supporting a bottom surface cutting tool for cutting the bottom surface of the elliptical hole in this tool rest, and in synchronization with the rotation of the lathe spindle on the main tool rest side. A rotating gear mechanism and proportional conversion for converting the rotation of the gear mechanism into a reciprocating linear motion proportional to the radial feed amount of the tool post and transmitting the reciprocating linear motion to the tool post as a radial reciprocating linear motion of the elliptical hole. Mechanisms are provided respectively, and further, between the tool post and the main tool post, a machining feed slide for giving a cutting feed in a direction away from the machining center in the radial direction of the elliptical hole and its radial cutting feed means are provided as the composite tool post. Built into Elliptical processing machine, characterized in Rukoto. 2. A cam driven by the gear mechanism, the proportional conversion mechanism, and a longitudinal sliding guide groove rotatably supported on the tip side and rotatably on the base side with respect to the cam. A swing lever, a piece slidably provided in a slide guide groove of the swing lever, a bracket which intersects the slide guide groove and fits in the piece, and is fixed to the feed slide, and swings on the feed slide. A movably supported intermediate lever, a link connecting the intermediate lever and the piece,
A pinion fixed to the intermediate lever, and a rack fixed to the machining feed slide and engaged with the pinion.
The elliptical machining mechanism described in the item.