JPH0255187B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a device for generating and machining a rotating bilobal hyperboloid surface, and its purpose is to create an uncut portion on the workpiece generation surface, etc. at the center of rotation of the workpiece while the cutting edge of the tool is in circular motion. The objective is to generate a high-precision rotating bilobal hyperboloid surface without causing any damage.

Conventionally, in order to create rotating bilobal hyperboloids and other aspheric surfaces, a workpiece W is attached to the end face of a spindle 2 and a spindle device 1 for rotating it at high speed is movable in the axis direction of the spindle, as shown in FIG. At the same time, the cutting tool 3 is fixed on a slide table 4 that is movable in a direction perpendicular to the spindle axis, and while the workpiece W is rotating at high speed, the slide table 4 and the spindle device 1 are fed by numerical control to adjust the cutting edge. There is a method that creates a hyperboloid of revolution by drawing a predetermined hyperboloid.

In such a conventional device, since the rotational speed of the workpiece at the cutting point of the cutting tool enables cutting, the cutting speed becomes close to zero at the center of rotation of the workpiece, so cutting cannot be performed, resulting in uncut residue.

In order to eliminate such conventional drawbacks, the present invention has the following features:
The purpose is to generate a rotating bilobal hyperboloid by rotating the tool side, and to avoid leaving uncut parts at the center of rotation of the workpiece, and to generate a rotating bilobal hyperboloid of all specifications for a constant tool rotation radius. The purpose of the present invention is to provide a highly versatile processing device that is equipped with adjustment elements that can create the following.

The principle of creation of a rotating bilobal hyperboloid according to the present invention will be explained.

In general, if a rotating bilobal hyperboloid is expressed in an xyz coordinate system, x ² /a ² −y ² +z ² /b ² =1 (a>0, b>0) The axis of rotational symmetry is the x-axis. This curved surface is an envelope surface of an inscribed sphere centered on a point on the x-axis. Therefore, as shown in Figure 2, the tool side passes through Oc and is tilted by θ with the x-axis as the rotation axis, rotates with the rotating tool radius, and if the workpiece side rotates once around the x-axis, the inscribed sphere Oc A part QQ′⌒−SS′⌒ is created. When part of this spherical surface includes MM', the hyperboloid MM' is cut. Move the position of Oc along the x-axis to the center position of the sphere touching the vertex T (see Figure 3) and at the same time
If we change the length of OcP, we get a rotating bilobal hyperboloid.
MTM′ is created.

Considering the xy plane, for the hyperboloid x ² /a ² -y ² /b ² = 1 and the circle (x+a+X) ² +y ² =R ² to touch, R ² = b ² {(a+X) ² /a ² +b ² −1} Also, in the inscribed circle touching the vertex, (x+a+X) ² +y ² =b ² {(a+X) ² /a ² +b ² −
1}, and satisfies x ⁼ -a, y=0, so if X ^at this time is _{X 0 ,} then = d/2/R ₀ = b ² d/2a = ………(1) Also, Z ² = ² − ² = R ² − ^{d 2} /4 If Z and X are controlled using the relationship expressed by equation (2), a rotating bilobal hyperboloid can be created.

An example of a processing device to which such a creation principle is applied is shown in FIGS. 4 and 5.

10 is a bed, and on this bed 10 a tool support stand 11 and a workpiece support stand 12 are provided.
The tool support stand 11 includes a face plate 21 that supports the tool 20.
A tool headstock 23 that rotatably supports a rotating spindle 22 equipped with a rotary spindle 22, a slide base 24 and a guide base 25 for sliding the headstock 23 in a direction parallel to the spindle axis U, and a guide base 25. It is comprised of a swivel base 26 and a swivel support base 27 on which a rotary machine is placed and can be rotated about an axis V perpendicular to the spindle axis U. A spindle drive motor 28 is mounted on the spindle stock 23, and pulleys 23a, 28a and a belt 29
It is rotatably connected to the rotating main shaft 22 via. On the face plate 21 is a tool 20 made of a diamond cutting tool that is eccentric to the center of rotation and protrudes in the axial direction.
is provided, and the cutting edge 20a of the tool performs a circular motion with a rotational diameter d. Note that the tool 20 is not limited to a single-point cutting tool, and a milling cutter or a grindstone can also be used. The swivel support base 27 is provided with an adjustment handle 27a, which is connected to the swivel base 26 via a worm and a worm gear (not shown), and the swivel base 26 can be adjusted by turning the handle 27a. The turning angle θ can be adjusted. Guide base 25 placed on swivel table 26
, a servo motor is connected to a slide table 24 on which a headstock 23 is mounted and a feed screw (not shown).
SMa is provided to control the amount of movement Z in FIG.

The workpiece support device 12 includes a workhead 3 that rotatably supports a rotating main shaft 30 that supports a workpiece W.
1, a movable base 32 and a slide base 33 for sliding the work head 31 in a direction parallel to the spindle axis T, and a guide base 3 for slidingly guiding the slide base 33 in a direction perpendicular to the spindle axis T.
4. The work head 3
1 is provided with a main shaft drive motor 35, which is connected to one end of the rotating main shaft 30 via a speed reduction mechanism. A face plate 30a is provided at the other end of the rotating main shaft 30, and a workpiece W is concentrically fixed to this face plate 30a. The guide base 34 is provided with an adjustment handle 34a, and a feed screw (not shown) that is threadedly engaged with the slide base 33 is connected to the handle 34a. By turning this handle 34a, the work head 31 is moved in a direction perpendicular to the axis, and the work head 31 is set in a positional relationship such that the cutting point of the tool 20 passes on the work rotation center line T, as shown in FIG. be able to. The slide base 33 has a servo motor SMb connected to a feed screw (not shown) that is screwed into the slide base 32.
is provided to control movement of the work head 31 in the workpiece axis direction.

40 is a numerical control device, which controls the servo motor;
SMa and SMb are controlled to maintain the relationship expressed by equation (2) above. Here, as shown in FIG. 5, the angle θ between the tool rotation axis U and the workpiece rotation axis T is constant, and the Z dimension with respect to the intersection Oc of both axes is controlled by the servo motor SMa. That is, the intersection Oc is an immovable point if the angle θ is constant, and if the headstock 23 is fed forward along the tool rotation axis U, a will increase, and if it is sent backward, Z will decrease. Also, the X dimension with respect to the intersection Oc is the servo motor
Controlled by SMb, if the work head 31 is fed forward (to the left in the drawing) along the workpiece rotation axis T, X will decrease, and if it is sent backward (to the right in the drawing), X will increase. Note that the angle θ formed by both axes is adjusted when changing the dimensions a and b of the rotating bilobal hyperboloid based on the relationship in equation (1) above, and changing this angle θ causes the tool cutting edge to move closer to the workpiece. Since it does not pass on the rotation axis T, it is necessary to make an adjustment using the handle 34a to move the work head 31 in a direction perpendicular to the work rotation axis. These adjustments are made manually as the creation specifications of the rotating bilobal hyperboloid are changed.

By calculating the above formula (2) with an electronic computer,
Several pairs of Z and X are determined, but the number of pairs to be determined may be increased or decreased depending on the required accuracy. The Z I asked for
The numerical control device 40 performs two-dimensional pulse distribution by connecting a large number of points defined by
In this case, the Z and X point group data are programmed in advance and stored in the storage device 41 built into the numerical control device 40. Of the pulse trains for the two axes simultaneously outputted from the numerical control device 40, the pulse train for the A-axis is applied to the servo motor SMa to move the tool headstock 23 in the direction of the tool rotation axis U to determine the distance from the intersection point Oc to the cutting edge rotation plane. Z is controlled, and the other B-axis pulse train is applied to the servo motor SMb to move the work head 31 in the direction of the work rotation axis V, thereby controlling the distance X from the intersection Oc to the work creation surface. In this way, when a set of Z and X is given and the work W is rotated once, a part of the paraboloid in Fig. 2
Since MM' is machined, each time the work W is rotated, another set of Z and X is given, and by sequentially shifting the machining point in the Z-axis direction, a rotating bilobal hyperboloid can be created.

In addition, it is also possible to shift the machining point in the Z-axis direction according to the rotation of the workpiece and control it along a helical locus. In this case, the motor for driving the workpiece is also a servo motor, and the numerical control device 40 is programmed with a set of point group data (α, Z, X) including the workpiece rotation angle α, and this data It suffices to distribute pulses to three axes at the same time and apply the distributed pulses to each servo motor.

According to the present invention, the tool is rotated around an axis that makes an angle with the workpiece axis, the tool and the workpiece are controlled to move relative to each other in the direction of the tool rotation axis and the workpiece rotation axis, and the workpiece is rotated. Since the tool is moved so as to draw a hyperboloid on the workpiece creation surface to create a rotating bilobal hyperboloid, even if the cutting point of the tool becomes the center of rotation of the workpiece, the cutting speed will not decrease and uncut material will remain. do not have.

Furthermore, since the A-axis and B-axis, which are the control axes, do not have to be controlled as a function of the rotation angle of the tool rotating at high speed, control is relatively easy and the mechanical system can be easily designed.

Also, a, b as the creation dimensions of the rotating bilobal hyperboloid
can be changed arbitrarily by adjusting the angle θ formed by the tool rotation axis with respect to the workpiece rotation axis, so the processing apparatus has the advantage of being versatile.

[Brief explanation of drawings]

Fig. 1 is a plan view showing a conventional device, Fig. 2 is an explanatory diagram of the creation principle of a rotating bilobal hyperboloid according to the present invention, and Fig. 3 is a plan view showing a conventional device.
The figure is a diagram showing the relationship with the inscribed sphere touching the vertex, the fourth
5 and 5 show a processing apparatus which is an embodiment of the present invention, with FIG. 4 being a front view and FIG. 5 being a plan view. DESCRIPTION OF SYMBOLS 11... Tool support device, 12... Work support device, 20... Tool, 23... Tool headstock, 24...
...Sliding base, 25...Guide base, 26...Swivel base, 27...Swivel support base, 30...Rotating main shaft, 3
1...Work head, 32...Sliding table, 33...
Slide base, 34... Guide base, SMa,
SMb...Servo motor.

Claims (1)

[Scope of Claims] 1. A workpiece support device that supports and rotates a workpiece in which a rotating bilobal hyperboloid is formed; a workpiece support device that has a rotational axis that is inclined with respect to the rotational axis of the workpiece; and a tool that is eccentrically protruded from one end thereof; a rotating spindle, a tool headstock that rotatably supports the rotating spindle, a first feeding means for moving the rotating spindle and the workpiece relative to each other in the axial direction of the rotating spindle, and a first feeding means that moves the rotating spindle and the workpiece in the direction of the workpiece rotational axis. and a numerical control device, the tool is rotated, and the rotating main shaft is moved in the axial direction by the first feeding device, and the workpiece is moved in the axial direction by the second feeding device. In a processing device that cuts a rotating bilobal hyperboloid x ² /a ² −y ² +z ² /b ² = 1 by controlling the θ is sinθ=b ² d/2a The axial movement amount Z of the rotating main shaft by the first feeding means and the axial movement amount X of the workpiece by the second feeding means. 1. A rotating bilobal hyperboloid generation processing device characterized by generating a rotating bilobal hyperboloid surface by controlling the relationship such that the following relationship is maintained. 2. The first feeding means includes a guide means for slidably guiding a tool headstock that rotatably supports the rotary spindle in an axial direction of the rotary spindle, and a guide means for moving the tool headstock guided by the guide means. 2. The rotating bilobal hyperboloid generating processing device according to claim 1, comprising a feed screw mechanism and a servo motor connected to the feed screw mechanism. 3. The second feeding means includes a guiding means for slidably guiding the work supporting device in the direction of the rotational axis of the work, a feed screw mechanism for moving the work supporting device guided by the guiding means, and a feeding screw mechanism for moving the work supporting device guided by the guiding means. 2. The rotating bilobal hyperboloid generating processing device according to claim 1, comprising a servo motor connected to a screw mechanism. 4. The first feeding means rotates the guide means for guiding the tool headstock about an axis that is perpendicular to a plane including the axis of the rotational spindle and the rotational axis of the workpiece and orthogonal to the axis of the rotational spindle. 3. The rotating bilobal hyperboloid generating processing apparatus according to claim 2, further comprising a turning adjustment means for adjusting the rotating bilobal surface. 5. The rotating bilobal hyperboloid generating device according to claim 3, wherein the second feeding means includes a movement adjusting means for adjusting the movement of the guiding means for guiding the work supporting device in a direction perpendicular to the guiding direction. Processing equipment.