JPS6048282B2 - Non-circular shape processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for machining non-circular parts, and more specifically, the part to be machined is gripped by a chuck at the tip of a spindle, and the spindle is held by a cam device. The present invention relates to a processing device that processes a predetermined non-circular shape by moving the device in a plane orthogonal to the main axis.

Conventionally, many processing devices for non-circular shapes have been developed and implemented, but the processing method and device of the present invention belong to a type of processing device that rotates and turns or grinds the parts to be processed. The spindle, which has a chuck that grips the part to be machined, is movable in a direction perpendicular to its axis, and by moving in accordance with the shape of the part to be machined, a desired non-circular shape can be machined. It belongs to the type of practice.

Processing equipment belonging to this type includes elliptical cutting machines and polygon cutting machines that are used to process only specific non-circular shapes, and machines that process arbitrary non-circular shapes with a predetermined main axis. There is a device that is configured to have a shaped cam and use the cam to move the main shaft in a direction perpendicular to its axis, but it generally has problems with rigidity and machining accuracy, making it difficult to achieve high efficiency and high precision. Many of them do not have sufficient capabilities to process them. A conventional processing device is illustrated in FIGS. 1 and 2 as a concept (2).

The apparatus shown in FIG.
is provided coaxially with the main shaft, and the main shaft is rotated while being biased toward a cam follower 5 fixed to the headstock so as to be rotatable five times.
Moreover, the main shaft is configured to be movable only in the lateral direction in FIG.

In this device, the part to be machined is gripped by a chuck at the tip of the main shaft, and the main shaft is rotated around the center of the cam plate 4. By rotating the main shaft, the cam plate 4 rotates together with the main shaft, and the cam surface 2 is rotated.
The main shaft rotates while moving left and right depending on the shape, and the desired shape is turned by cutting with the cutting tool 8. With this machining method, turning is possible at a relatively constant cutting speed (although it varies in proportion to the distance between the spindle center and the machining position), but as is clear from the figure, the rake angle of the cutting tool 8, the clearance It has the disadvantage that the angle of entry varies widely. FIG. 2 shows another example of a conventional device, in which a ring-shaped cam plate 4 having an inner cam 2 and an outer cam 3 formed in an equidistant curve with respect to the shape 1 of the part to be machined is used as the main shaft. The cam plate 4 is held between a cam follower 5 which is rotatably fixed to the headstock and comes into contact with the inner cam 2 and two backup rollers 6 which come into contact with the outer cam 3, and the backup rollers 6 are integrated into one body. The cam plate 4 is supported so as to be slidable only in the direction toward the cam follower 5 (left-right direction in the figure), and the cam plate 4 is pressed by a strong spring 7. The parts to be machined are mounted coaxially with the center of the cam plate 4, and as the main shaft rotates, the cam plate 4, which is held between the cam follower 5 and two backup rollers 6, is aligned vertically and horizontally. The main shaft (component) coaxial with it also rotates while moving vertically and horizontally. When turning is performed by aligning the tip of the cutting tool 8 with the center of the cam follower 5 and rotating the main shaft three times, the inner cam 2 forms a curve equidistant with the shape of the part, so that the part is turned into the desired shape. In this processing method, unlike the above-mentioned first conventional example, the rake angle and relief angle of the cutting tool 8 are relatively constant, but the posture of the cam plate 4 is Since the rotation of the component is controlled by two backup rollers 6, the rotation of the component is a combination of the back and forth rotation controlled by the cam plate 4 and the rotation of the main shaft, and the cutting speed fluctuates widely, and in some cases has the disadvantage that the parts to be machined may partially stop or reverse, and furthermore, the shape and accuracy of the parts are determined by the inner cam surface 2, so it is difficult to manufacture high-precision cams compared to outer cams. This method also has the drawback that the shape of the machined part becomes the correct desired shape only when cutting at the center position of the cam follower 5, and as the cutting position moves away from the center of the cam follower 5, the shape becomes distorted. Yes.o
The present invention eliminates the drawbacks of these conventional methods, always keeps the rake angle of the cutting tool constant during machining, has high rigidity, enables higher speed rotation or heavier cutting than conventional equipment, and also allows grinding if necessary. The object of the present invention is to obtain a method and apparatus for machining non-circular shapes.

The present invention will be described in detail based on examples.

FIG. 3 is a conceptual diagram showing the principle of processing of the present invention.
As an example, processing of a part having a substantially square shape with arcuate sides and corners will be described.

In other words, the shape 1 of this part has four sides Pl, P3, and P, respectively.
5, the radius is R1 and R2 with P7 as the center, the corner is rounded with a circular arc with radius R3, and the center is P2
, P4, P6, and P8. While rotating this rectangular shaped part 11 in the counterclockwise direction as shown by the arrow, the cutting tool 8 is set at the cutting point K fixed on the X axis of the
When machining shape 1 of a non-circular part by cutting, while cutting the edge, point P1, which is the center of the arc, is fixed on the X axis and rotated, and after cutting to point B ( That is, after the center P2 of the corner I reaches P2' on the X-axis), the center P2 of the corner I is fixed at the point P2' on the , P6, P7, and P8 are fixed on the X-axis and cutting is performed sequentially.The machined surface at the cutting point K is always orthogonal to the X-axis, and cutting with a constant rake angle is possible. Grinding is also possible if a grindstone 8' is provided so as to be in contact with it. At this time, the center O' of the part 11
moves on the arc 0A-0-O'-0B during the cutting of side Tsukuda, moves on the arc 0B-0D-0C during the cutting of the corner I, and moves on the arc 0B-0D-0C during the cutting of the side CD in the figure. Convex arc to the left 0C-
Move on 0D and on 0D-0C-0A during cutting of the corner DE and return to the original position 0A, and during the latter half of cutting from point E to point A, move on the center O' of the part. passes through the above-mentioned locus again and completes one rotation of the part.

Next, a cam configuration that satisfies the above conditions will be considered.

The embodiment shown in FIG. 3 has one main cam 12, two auxiliary cams 13, 14, and three cam followers 15, 16, 17 rotatably fixed to the coordinate system (i.e., the headstock). However, the cam follower 15 provided on the X axis corresponds to the main cam 12, and the other two cam followers 16 and 17 arranged at an interval of approximately 120 degrees correspond to the auxiliary cams 13 and 14, respectively.
It is always in contact with each cam surface.

As mentioned above, since the machining section AB of the part rotates around the point P1 on the X axis, the distance between the centers of the cam followers 15, 16, 17 and the rotation center P1 is constant, All of the 14 cam surfaces form circular arcs 12a, 13a, and 14a centered on P1.

(If the edge grip is a non-circular arc, the center of the radius of curvature of the shape should always be on the The profile is an envelope of a circular arc centered on the point where the locus of the center of the cam follower moves on the X-axis at a distance from the cutting point K by the radius of curvature, that is, the center P1 of the radius of curvature.The same is true for all cams. Therefore, the following explanation will be made only for circular arcs, and the explanation for non-circular arcs will be omitted.Side AB
If is a straight line, the center of the arc will be the point at infinity, and the cam profile will be a straight line parallel to the shape 1 of the part 11. If the side AB is a concave arc, the center point P1 of the arc will be the main point. Except when it is inside the cam 12, by setting the center point P1 on the left side, processing can be performed in exactly the same way. ) In particular, the cam surface 12a of the main cam 12 has a rotation center Pl, . Since the cutting point K and the center of the cam follower 15 are on a straight line, they form an equidistant curve with respect to the shape of the part to be machined. As mentioned above, when the machining is completed up to point B, the center point P2 of the arc I is the point P on the X axis.
2', and the machining of the arc I is performed by rotating J around this point.
Cut while cutting. At this time as well, since the distance between point P2' and the center of each cam follower is constant, the cam profiles 12b, 13b, and 14b all form circular arcs centered on point P2'. In particular, the cam profile 12b of the main cam 12 is an equidistant curve with the shape I of the part. Thereafter, cams are formed in the same manner by circular arcs centered at P3, P4, . . . . That is, the main cam 12 has a cam profile formed with a curve equidistant from the shape of the part to be machined, and the plurality of auxiliary cams 13, 1
4 each have a cam profile formed by a circular arc of the shape of the part to be machined or a circular arc centered on the center of the radius of curvature.

(Strictly speaking, as mentioned above, the center trajectory of the cam follower of both the main cam and the auxiliary cam is the profile of the cam that meets the above conditions.) In the processing method configured as described above, , when the cutting point K moves on the X-axis, that is, when considering the shape to be cut when the cutting point K moves to K' in Fig. 3, during cutting between sides A'B', the X-axis Since it rotates around the upper point P1, the radius of rotation R1 becomes a circular arc that is increased by a distance KK'.

Similarly, corner B'C' rotates around point P2' on the X-axis, forming an arc whose radius R2 is longer by KK'. The same is true for the following P3, P4, . . . , and they form equidistant curves separated by a distance KK'. Figures 4, 5, and 6 show an example of a processing device that embodies the above-mentioned processing method. Figure 4 is an external perspective view showing the main parts of the device, and Figure 5 is a vertical cross-section of the headstock. The top view, FIG. 6, is a sectional view taken along line AA in FIG. 5.

In FIG. 4, a headstock 22 is fixed on a bed 21, and a cam device 23 of the present invention is located in front of the headstock 22.
The chuck 24 grips the part 11 to be processed.

There is a tool rest 26 on the bed 21 facing the part 11,
The tool rest 26 has a vertical slide 27 and a horizontal slide 28 that can slide left and right and back and forth with respect to the headstock as in a normal lathe.
The tool post 29 is located at the upper end of the tool post 29, and the cutting tool 8
is held. The structure of the tool rest is sufficient if it is similar to that of a normal lathe, so it will not be described in detail here. FIG. 5 is a vertical sectional view of the headstock of the processing device of the present invention, showing a drive shaft 31 that rotates by drive from a drive source (not shown) and a drive shaft 31 that rotates through a coupling 35. A cam device 23 of the present invention is provided which is driven by the cam device 23 of the present invention.

In this embodiment, the drive shaft 31 is rotatably supported by a sleeve 33 via a bearing 32 at the rear (left side in the figure) of the headstock 22, and the sleeve 33 is fixed to the headstock.
The drive shaft 31 receives power from a drive source (not shown) through a pulley 34 at its rear end, and is connected to the cam device 23 via a coupling 35 at its other end. This coupling 35 is used to transmit power by following the movement of the main shaft 36 in a direction perpendicular to the shaft by the cam device 23, and is used in various types of joints that can transmit power even if the amount of eccentricity is large. For example, a Cardan joint, an Orgum joint, a universal joint, etc. can be used, and in this embodiment, a Schmitt joint is used. The cam device 23 is disposed on the front surface (right side in the drawing) of the headstock 22 as described above.

The cam device 23 has a substantially cylindrical fixing member 37 on its outer periphery, and a plurality of cam follower holding shafts 38 are fitted radially from the outer periphery of the fixing member 37 toward the center. cam follower shaft 39 provided parallel to
, has a cam follower 15 or 16 rotatably attached to the shaft, has an adjustment nut 42 held by a holder 41 at the rear end, and is configured to be movable toward the main shaft. The cam follower device extending downward from the main shaft 36 similarly has a cam follower holding shaft 43, a cam follower shaft 44, and a cam follower 17 at the tip, and a holder 4 at the rear end.
Adjustment screw 47 and lock nut 48 screwed into 6
A spring 49 inserted into the adjustment screw 47 presses the cam follower 17 against the cam, and the biasing force can be adjusted by the adjustment screw 47. At the center of the cam device 23 is the main shaft 36 connected to the drive shaft 31 via the coupling 35 as described above, and includes the key 54 and the cam adapter 5.
It has three cams 12, 13, 14 via 3.

Of these three cams, the frontmost one (right end in the drawing) is the main cam 1.
2, and the other two are auxiliary cams 13 and 14, which are fixed to the cam adapter 53 as one unit, and when changing the shape of the parts, etc., they can be combined into one unit by removing the front cover 56. It is constructed so that it can be easily replaced.
The thrust is between the shoulder 36a of the main shaft 36 and the cam adapter 53.
The collar 53a of the thrust collar 55 and the front cover 56
It is supported so that it can be moved in the direction orthogonal to the axis. A chuck 24 is provided at the tip of the main shaft 36 and is adapted to grip the part 11 to be machined.

FIG. 6 is a sectional view along line AA in FIG. 5, showing the actual shape of the cam and the arrangement of the cam followers in this embodiment.
With respect to the shape 1 of the part to be machined, which is drawn as an imaginary line in the center of FIG. It is always in contact with the left cam follower 15.

The first auxiliary cam 13 has a shape in which only the upper half is drawn with a broken line, and comes into contact with the cam follower 16 on the upper right side.
Only the lower half of the second auxiliary cam 14 is shown as a broken line, and is in contact with the cam follower 17 on the lower right side. The shapes of the remaining portions of the first auxiliary cam 13 and the second auxiliary cam 52 are both point symmetrical to the illustrated shape with respect to the center of the main axis. All three cam followers 15, 16, 17 are provided in substantially fixed positions, and the holders 4 provided on the left and upper right cam follower devices
1. The position adjustment mechanism consisting of the adjustment nut 42, etc. is for accurately positioning the cam follower 15 or 16, and the biasing device using the spring 49 provided on the cam follower device on the lower right side is used for manufacturing the cam, etc. It is intended to absorb errors and operate smoothly, and does not substantially move the position of the cam follower.

In the processing apparatus of the present invention configured as described above,
The drive shaft 31 is driven by power from a drive source (not shown).
When the is rotated, the main shaft 36 rotates via the coupling 35, and as described above, the three cam followers 15, 16, 17 are provided at fixed positions, and the three cam followers 15, 16, 17 are connected to one body and rotate together with the main shaft. Since the cams 12, 13, and 14 are always in contact with each other, the main shaft 36 is controlled to move within a plane perpendicular to the shaft by the cam and the cam follower to a position corresponding to the rotation angle of the main shaft.

The method of controlling the movement, the direction of movement, the amount of movement, etc. have already been described in detail with reference to FIG. 3, so they will not be repeated here. Therefore, in the processing apparatus shown in FIG. 4, the part 11 held by the chuck 24 rotates and makes a predetermined movement in a plane perpendicular to the axis, and is cut into a desired shape by the cutting tool 8. . FIG. 7 is a longitudinal sectional view of another embodiment of the present invention, in which a cam device 23 is installed in the headstock 22.
Furthermore, the cams 12, 13, 14 and a non-circular gear 59 driven by a drive source (not shown) are combined into an L body together with a cam adapter 53, resulting in a more compact configuration. The non-circular gear 59 is provided to substantially eliminate changes in cutting speed caused by the combination of rotation of the main shaft, movement in the orthogonal direction, and change in distance from the center of the part to the cutting point. It varies depending on the shape and dimensions of the part and the desired cutting speed, and varies depending on the part to be machined.The cam and the cam adapter 53 are combined together with the cam and can be easily replaced. The thrust of the main shaft 36 is taken by sandwiching the shoulder 36a of the main shaft 36 and the collar 53a of the cam adapter 53 between the rear cover 55 and the front cover 56, as in the first embodiment (FIG. 5). However, a thrust collar 60 is provided so that the main shaft 36 can be held even if the front cover 56 is removed when changing parts. The rest of the configuration is almost the same as the first embodiment (see FIG. 5), so a description thereof will be omitted here.
Note that since the main shaft 36 moves in a direction perpendicular to the axis, the non-circular gear 59 also moves, and of course a fixed gear train will come out of mesh, but an intermediate gear that moves together with the gear 59 is provided. It is well known that driving forces can be transmitted by this method. In the above explanation, we have only explained the case of one main cam and two auxiliary cams, but the same effect can be obtained even if there are three or more auxiliary cams and the number of cam follower devices corresponding to each cam is provided. It is clear that it can be constructed as

The non-circular shape machining device of the present invention is constructed as described above, and in particular, since all the cam follower devices are provided at substantially fixed positions, it is easy to create a structure with sufficiently high rigidity. As a result, it is possible to perform heavy cutting or high-speed rotation compared to conventional equipment, and has the effect of improving machining accuracy.It also has the effect of cutting end faces and slopes, or cutting two or more places in the same cam or process. When cutting, it has great effects such as being able to create a correct equidistant curve with respect to the reference shape.

In the explanation so far, only the case where a cutting tool, particularly a cutting tool, is used has been described, but in the processing method and apparatus of the present invention, the cutting surface is always perpendicular to the center of rotation at the cutting point K. In addition to cutting with a cutting tool, it is also possible to perform milling or grinding by installing a tool axis on the tool post, and it is also possible to fit together cut parts and ground parts, making it possible to cut even larger parts. It has remarkable effects such as being able to use it for various purposes.

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[Brief explanation of the drawing]

Figures 1 and 2 are conceptual diagrams of the conventional processing method, Figure 3 is a conceptual diagram explaining the processing method of the present invention, and Figure 4 is a conceptual diagram of the processing method of the present invention.
A perspective view of the embodiment, FIG. 5 is a vertical sectional view of the headstock, FIG. 6 is a sectional view taken along line AA in FIG. 5, and a seventh gate view is a vertical sectional view of the headstock of another embodiment. 1... Shape of the part to be machined, 8,8'...
...Bite or processing tool, 12... Main cam, 13, 14... Auxiliary cam, 15, 16, 17
...Cam follower, 22... Headstock,
23...Cam device, 24...Chuck, 25...Parts, 26...Turret post,
36...Main shaft, 59...Non-circular gear.

Claims (1)

[Claims] 1. A main shaft having a cam molded into a predetermined shape corresponding to the shape of the part to be machined is rotatably supported on the head stock and movable in a direction orthogonal to the rotation axis, and at least In a type of non-circular machining device in which the position of the spindle is regulated by a cam follower fixed to a single headstock, the cam is arranged such that the center locus of the cam follower is equal to the non-circular shape to be machined. A main cam formed as a distance curve, and a plurality of auxiliary cams formed so that the center locus of the cam follower is on an arc centered on the arc of the non-circular shape to be machined or the center of the radius of curvature. It consists of a cam body connected to one body, a plurality of cam followers corresponding to each of the main cam and a plurality of auxiliary cams, the position of which is substantially fixed to the headstock, and a cam body that rotates the main shaft. A non-circular shape machining device comprising a drive transmission mechanism for driving, a chuck for gripping a part to be machined on the front side thereof, and a tool rest having a cutting tool or a grindstone disposed opposite to the chuck. . 2. The non-circular shape machining device according to claim 1, wherein the drive transmission mechanism has a non-circular gear in a part thereof. 3. The non-circular shape machining device according to claim 2, wherein the non-circular gear is integrally connected to the cam body.