JPH0643004B2 - Oval processing machine - Google Patents

Description

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

Conventional Technology Conventionally, when a cylindrical inner peripheral surface and a circular bottom surface are simultaneously processed, on a base of one combined tool post,
A feed slide that is slidable in the axial direction of the lathe spindle, and a feed slide that is slidable in a perpendicular direction to the lathe spindle are separately attached, and a blade for cutting the inner surface of the cylinder on each slide, and A processing machine is separately provided that includes a blade for cutting the bottom surface.

The blade for cylindrical surface processing moves from the opening surface of the workpiece toward the inner bottom surface, and the blade for bottom surface processing cuts from the center portion of the bottom surface to the outer peripheral portion by machining feed. During this time, the workpiece is held on the lathe spindle,
It is rotating at a constant speed. In such a complex cutting process, the cutting feed between the cylindrical inner peripheral surface and the bottom surface thereof is set to be substantially the same.

Then, after such processing, the surpluses at the corners of the processed portion are cut off from both sides at right angles to each other, thereby eliminating the end of processing such as when individual cutting is performed, and there is no chattering. Processing is possible.

The above-described conventional processing method is a method well known and frequently used as a method for efficiently and rationalizing a cylindrical hole by moving two blades at the same time.

However, when the elliptical hole of the workpiece is the object to be machined, it is necessary to generate an elliptical shape for each blade, so that a synchronous movement other than cutting feed is required for each blade.

That is, for a tool for machining the inner peripheral surface of an elliptical hole, a reciprocating linear motion corresponding to the difference between the major axis and the minor axis of the ellipse is required, and moreover, in order to keep the rake angle of the tool constant, the tool is shaken. Dynamic movement is required. In addition, in addition to the reciprocating linear motion corresponding to the difference between the long diameter and the short diameter, the cutting tool for bottom surface cutting also has a swinging motion that constantly holds the direction of the cutting tool constant with respect to the cutting direction. Will be needed.

As described above, simultaneous machining of the elliptical inner peripheral surface and its bottom surface requires complicated movements and further demands such as rough cutting and finishing machining. , Also not developed.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a clever elliptical machining machine capable of simultaneously machining an elliptical inner peripheral surface and its bottom surface while satisfying all of the above-mentioned plurality of motion conditions and efficiently and stably. Is.

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

In order to cut the inner peripheral surface of the elliptical hole, one of the tool rests swingably holds the tool in a state where it can be cut and fed in the generatrix direction of the inner peripheral surface. The other tool rest is supported in a state of being movable in the radial direction of the elliptical hole and swingable so as to always face the cutting direction in order to process the bottom surface of the elliptical hole.

Further, the compound tool post incorporates a gear mechanism, a cam mechanism, and a proportional conversion mechanism that rotate in synchronization with the lathe spindle. This cam mechanism converts the rotation of the gear mechanism into a reciprocating linear motion, and applies this to one tool post as a reciprocating linear motion in the radial direction of the elliptical hole. As a result, the tool for machining the inner peripheral surface moves along the desired elliptical inner peripheral surface by moving away from the center when machining the major diameter portion and moving toward the center when machining the minor diameter portion. Perform elliptical feeding movement.

The proportional conversion mechanism converts the rotation of the gear mechanism into a reciprocating linear motion by a cam / lever mechanism, and changes the stroke of the reciprocating linear motion in proportion to the radial feed amount of the elliptical hole. It is transmitted to the other tool post for bottom machining. 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, one of the blades for machining the inner peripheral surface is sent from the opening side of the elliptical hole toward the bottom by a cutting feed motion, creates an elliptical surface by a reciprocating linear motion, and scoops by the rocking. The corner is always kept constant and good cutting is performed. At the same time, the other 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. The elliptical bottom surface will be processed while making corrections in the tangential direction.

Therefore, the elliptical machining machine of the present invention can simultaneously machine the inner peripheral surface of the elliptical hole and the elliptical bottom surface,
In addition to improving the machining efficiency, it is possible to perform good internal cutting under numerical control.

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 composite tool rest 3 is provided. The composite tool rest 3 is provided on the slide guide surface 5 of the bed 4 so as to be movable back and forth in the direction of the lathe spindle 2, and is driven in a forward or backward direction by a feed unit or the like (not shown). ing.

Then, the compound tool post 3 has an upper surface thereof by a slide guide surface 6 in a direction orthogonal to the lathe spindle 2.
The elliptical feed slide 7 and the feed slide 8 are movably supported. On the other hand, the elliptical feed slide 7 has a fixed displacement slide 10 by means of a slide guide surface 9 in the same direction as well as the slide guide surface 1 of the fixed change slide 10.
1, the cutting feed slide 12 is movably supported in the direction of the lathe spindle 2. The other feed slide 8 holds the machining feed slide 14 in a retractable state by a slide guide surface 13 in a direction orthogonal to the lathe spindle 2.

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 is provided with an axial cutting feed means provided between the cutting feed slide 12 and the constant displacement slide 10, that is, a feed nut 21 and a feed screw 22 so that the lathe spindle 2 is rotated.
It can be processed and fed in the direction of. The feed screw 22 is driven by a feed servo motor 23 mounted on the fixed displacement slide 10, an output shaft thereof, and a timing belt / pulley 24 wound around the feed screw 22. ing. 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.
A feed servomotor 27 attached to this, a feed nut 28 attached to the compound tool post 3, and a feed screw 29 which is inserted into the feed nut 28 under a screw pair and is driven by the servomotor 27. It can be moved along the guide surface 6.

Further, a gear mechanism is provided below the compound tool post 3 inside the case 30 to take in synchronous rotation from the senna main shaft 2. That is, the rotation of the lathe main shaft 2 is given to the input shaft 31 by a winding rolling means or the like, and one gear 3 is provided at the input gear 32.
3, 34 are transmitted 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, and is supported at the base end portion by a fulcrum shaft 49 parallel to the cam shaft 41 so as to be swingable with respect to the compound tool rest 3. The slide guide groove 50 in the middle holds the piece 51 in a movable state. This piece 51
Is fitted in the sliding groove 53 of the bracket 52 attached to the feed slide 8 in a sliding pair, and is connected to the 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. And this pinion 58
Engages 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 6 fixed to the support shaft 16 by an eccentric pin 65, a connecting pin 66 and a connecting link 67.
It is connected to the tip of 8. 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.

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 of the feed slide 8 outward from the center and the reciprocating linear movement of the processing feed slide 14, a spiral elliptical movement is drawn, and the circular circle 76 is used as the starting point to move outward. 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 intermediary shaft 57 depends on 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 of this direction is given by the proportional conversion mechanism including the swing lever 48, the piece 51, and the bracket 52, the swing angle is gradually set to be larger as the ellipse of the machining locus becomes larger. . Of course, such a feed motion and a direction correction motion are always synchronized with the rotary motion of the lathe spindle 2, so that they do not deviate from 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. 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 of all, first, a tool for machining the inner peripheral surface of an elliptical hole and a tool for machining the bottom surface of the compound tool post are fed in the machining direction,
And, since it is incorporated in a state in which the radial feed motion of the ellipse is provided, the inner peripheral surface and the bottom surface of the elliptical hole can be cut at the same time. Therefore, the processing efficiency of this type of workpiece is increased as compared with the conventional one.

Secondly, since the cutting tool for machining the inner peripheral surface is subjected to the movement in the radial direction of the elliptical hole and the movement that the rake angle is always constant, the machining is always performed in the best condition. Therefore, a good machined surface without chattering can be obtained.

And thirdly, the bottom surface cutting tool cuts the bottom surface while drawing a perfect circle at 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. Moreover, since the bottom surface cutting tool always continues cutting at a constant angle with respect to the cutting direction, the bottom surface can be machined as a clean finished surface.

Further, fourthly, the feeding of the inner peripheral surface cutting tool and the bottom surface cutting tool in the radial direction of the ellipse, and the rake angle correction and the cutting direction correction motion are always synchronized with the rotary motion of the workpiece. Since it is performed in a state, there is no deviation between those movements and the elliptical hole to be machined, and ideal cutting machining can be efficiently performed in one step.

[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 ... Compound 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, fulcrum shafts, 51, bridges, 55, links, 56, intermediate levers, 58, pinions, 59.
Rack, 65 ... Eccentric pin, 66 ... Connecting pin, 67 ...
... Link for connection, 68 ... Lever, 71 ... Workpiece, 73 ... Elliptical hole, 74 ... Inner peripheral surface, 75 ... Bottom surface.

Continuation of the front page (56) References JP-A-52-147266 (JP, A) JP-A-59-152001 (JP, A) JP-A-59-76755 (JP, A)

Claims (1)

[Claims] 1. A compound tool post is arranged so as to face a lathe spindle that holds a workpiece while rotating it, and two tool posts can be moved in the radial direction of an elliptical hole of the workpiece. The turrets are provided side by side in a state in which one of the tool rests rotatably supports a tool for inner peripheral surface cutting for cutting the inner peripheral surface of the elliptical hole, and the other tool rest for cutting the bottom surface of the elliptical hole. A gear mechanism that rotatably supports a machining tool and that rotates on the composite tool post side in synchronization with the rotation of the lathe spindle.
A cam mechanism that converts the rotation of this gear mechanism into a reciprocating linear motion and transmits it to the one tool post as a radial reciprocating linear motion of an elliptical hole, and the rotation of the gear mechanism in the radial direction of the other tool post. Providing a proportional conversion mechanism for converting to a reciprocating linear motion proportional to the feed amount and transmitting to the other tool rest as a reciprocating linear motion in the radial direction of the elliptical hole, and further on the one tool rest side by the gear mechanism. An oscillating motion mechanism that is driven to give an oscillating motion to the inner peripheral surface cutting tool,
Axial cutting feed means for cutting and feeding the inner peripheral surface cutting tool in the axial direction of the work piece, and the above inner peripheral surface processing blade away from the machining center in the radial direction of the elliptical hole during finishing after rough cutting. Incorporating a constant displacement means for displacing a fixed amount in the direction, and also to the other tool post, a transmission mechanism that transmits the swinging motion of the proportional conversion mechanism to the tool for bottom machining, and an elliptical hole in the other tool post. An elliptical machining machine characterized in that radial cutting feed means for giving a cutting feed in a direction away from the machining center in the radial direction is incorporated in the compound tool post.