JPS62188615A - Machining method for scroll component - Google Patents

Abstract

PURPOSE:To machine a scroll component at high speed and that in a highly accurate manner, by keeping moving paths of a tool constant in rectilinear form when the scroll component being used for a compressor of a refrigerator or the like is machined, and synchronizing the tool movement with rotation of the component mechanically. CONSTITUTION:When the outside of a wall 2 of a scroll component 1 is machined, an outer wall surface 14 is of an involute curve, and a tool 3 in use is, for example, an end mill. And, a turning center of this tool 3 is designed to be shiftable on a tangent (d) line offsetting a radius portion of a base circle of the involute curve. In addition, the scroll component 1 is set up to be rotatable with a center (a) point of the base circle as the center. These movements are carried out by a numerically controlled machine tool. Rectilinear motion in an arrow direction of the tool 3 and rotational motion of the component 1 come to simple proportion, and it is offset as far as the radius portion of the tool 3 in the arrow direction from the involute curve of the outer wall surface 14, whereby if movement of the tool 3 and rotation of the component 1 are carried out, the outer wall surface 14 is machinable. In this connection, an inner wall surface 16 is also machinable.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for processing scroll parts used in compressors such as refrigerators.

<Prior art> When machining the wall surface of a scroll component used in a compressor such as a refrigerator with a tool such as an end mill, the relational expression of the involute curve of the scroll component was conventionally calculated by a computer and converted into an orthogonal coordinate system. These coordinate values were then input into the NC device of the machining center in the orthogonal x-y coordinate system as movement commands from point to point, and machining was performed by allowing the tool and scroll component to move relative to each other. .

Therefore, the motion locus of the tool has a 5-wound shape.

<Problems to be Solved by the Invention> The conventional processing of scroll parts has the following drawbacks.

(2) The time it takes for the tool to move the distance from the current point to the next point is limited to the time required for calculation processing in one block of the NC device, and the upper limit of the tool feed rate is determined, making high-speed machining impossible.

■ Due to the tracking delay of the NC device's servo, X +, Y
When interpolation is performed, the error in the movement trajectory of the tool increases as it approaches the center of the scroll component, making it impossible to increase the feed rate of the tool.

■ Computer processing is required to convert the tool movement locus into X-Y coordinate values.The present invention was made to effectively solve the above drawbacks, and allows scroll parts to be machined at high speed and with high precision. The purpose of this invention is to provide a method for processing scroll parts.

Means for Solving the Problems> The gist of the present invention to achieve the above object is a scroll component processing method for processing a spiral wall of an involute curve of a scroll component, the method comprising: While moving the center position of the processing tool on a straight line tangent to the circle, the scroll part is rotated about the center of the base circle of the involute curve, and the linear movement of the tool and the rotation of the scroll part are kept at a constant ratio. The present invention resides in a method of processing a scroll component, which is characterized by mechanically synchronizing the scroll parts.

Function: The locus of movement of the tool is kept constant in a straight line, and the linear movement of the tool and the rotation of the scroll parts are mechanically synchronized.

Example of implementation> Fig. 1(a) shows the plane of the scroll part, Fig. 1(b) shows the plane of the scroll part.
The scroll part 1 shown in the figure is a main part used as a compressor of a refrigerator, etc., and the wall 2 of the involute curve connects the other part ( (Scroll parts with opposite spirals) and compress the fluid from the outer periphery toward the center. For this reason, the accuracy of the inner and outer wall surfaces of the wall 2 must be maintained at a high level of accuracy since airtightness is required.

Fig. 2 shows a machine tool for processing a scroll part 1, which includes a spindle 4 equipped with a tool 3, a spindle head 5 that rotationally drives these, and a spindle head 5 that moves the spindle head 5 up and down (Z-axis). Feed drive device 6, column 7, and scroll component 1
a chuck 8 that grasps the chuck 8, a rotary table 9 that rotates these (C axis), a moving table 101 that moves in the left and right direction (X axis), and a saddle 1 that moves in the front and rear direction (Y axis).
1 and a bed 12, and the three perpendicular axes of X, Y, and Z and the rotation axis C-axis are controlled by commands from the NCC vehicle 13 and others.

FIG. 3 shows the relationship between the scroll part 1 and the tool 3,
This is a case where the outside of the wall 2 of the scroll component 1 is processed.

Outer wall surface! 4 is an involute curve defined by a base circle 15 with a radius R8, and the tool 3 is, for example, an end mill.

The rotation center point of the tool 3 is movable on a tangent line d offset by a radius of 8 g from the base circle 15, and the scroll part 1 is arranged so as to be rotatable about the center point a of the base circle 15. There is. These movements are performed by the NC machine tool shown in FIG. An offset of 80 minutes in radius is performed on the Y arm (or (machining depth).

Here, the angle between the starting point S of the involute curve and the tangent point e between the d line and the base circle 13 is ψ, the angle θ between the intersection point C of the involute curve and the d line and point 5, and the angle between the 0 point and e The angle of the point is φ, the distance between point a and point 0 is r, and the distance between point e and point 0 is X
When a is set, the following relational expression holds true.

θ. m tanΦ. −φ. (Involute Kanzheng 0
...(1) (1) From equation (3), Xo and ψ are simply proportional.

When the tool A3 contacts the outer wall 14, the radius of the tool 3 is r. The following relational expression holds true.

0o-tanφ. −φ. ...(5
) Here ψC″: ψ0+α ... (9)
xo=xo+ψ. ...Because it is αG (
8) The equation becomes, and the linear movement of the tool 3 in the X direction and the scroll part l
The rotational movement of is simply proportional, and the tool radius numerator c in the X direction
The outer wall surface 14 can be machined by offsetting the involute curve of the outer wall surface 14 by a rotation angle α and moving the tool 3 and rotating the scroll part 1 according to the ratio α9. The inner wall surface 16 can also be processed in the same manner.

This synchronization is shown in FIGS. 4(a) and 4(b).

FIG. 5(a) shows the rotating table, -pull 9 and the moving table lO.
The 0-rotation electric motor 18 rotates the shafts of the gear 20 and the worm 21 by the coupling 19, and the worm 21 meshes with the worm wheel 22 to rotate the rotary table 9.

A gear 20 meshes with a gear 23, a gear 24 coaxial with the gear 23 meshes with a gear 25, and a gear 26 coaxial with the gear 25 meshes with a gear 27 to rotate a feed nut 28 coupled to the gear 27. The rotation of the feed nut 28 causes the moving table 10 to move linearly relative to the feed screw 29. The feed screw 29 is coupled to a feed motor 33 by a coupling 32, and the rotation of the feed motor 33 positions the moving table IO immediately before and after machining.
During processing, the power feeding percentage machine 33 is stopped.

Here, the rotation angle of the rotary table 9 is ψ, and the rotation angle of the rotary motor 18 is ψ. , the number of threads of the worm 21 is N□, the number of teeth of the worm wheel 22 is N2 gears 20, 23.24.25.
The number of teeth of 28.27 is N 3 , Na ,
N s , Na , N 7 , Na , the amount of advance per revolution of the feed nut 28 is L, the moving table 1
Letting the position of 0 be X, ), the following relational expression holds true.

(conversion), from formula 03, (4), from formula 04...α, N 3 , Na , N s , Na
The combination eliminates approximately π (pi) within the allowable error.

The above mechanism enables synchronization of rotation and linear motion corresponding to equation (4), and allows the relative feed speed of the tool 3 to be increased.

FIG. 5(b) shows a cross-sectional view of the rotary table 9 and the movable table 10. The rotary table 9 is coupled to the worm wheel 22 and rotates on the movable table IO. The moving table 10 is guided by linear guides 38, 37 and moved linearly on the saddle 11 by means of a feed screw 29 and a feed nut 28.

Therefore, the rotation of rotary table 9 and the movement of movable table 10 (linear movement of tool 3) are mechanically synchronized, making it possible to increase the feed rate without performing complicated control.

<Effects of the Invention> The scroll component processing method of the present invention rotates the scroll component around the center of the base circle of the involute curve of the scroll component, moves the tool on a straight line tangent to the base circle, and rotates the scroll component. Since the movement of the tool and the tool are mechanically synchronized at a fixed ratio, scroll parts can be machined at high speed and with high accuracy without the need for complex control for synchronization. As a result, there are no restrictions on processing due to numerical control or the like.

[Brief explanation of drawings]

Figure 1(a) is a plan view of the scroll parts, Figure 1(b)
Figure 1 is a sectional view taken along the line III in the bottom, Figure 2 is a perspective view of a machine tool that implements the method of the present invention, Figure 3 is a conceptual diagram showing the relationship between tools and scroll parts, and Figure 4 (a). 4(b) is a conceptual diagram showing the relationship between the tool and the scroll part in the machining start state, FIG. 4(b) is a conceptual diagram showing the relationship between the tool and the scroll part in the machining completed state, and FIG. 5(a) is the rotary table and the moving table. Figure 5 (b) is an expanded conceptual diagram showing the synchronization mechanism with
) is a sectional view of the rotating table and the moving table. In the drawing, 1 is a scroll part, 3 is a tool, and 9 is a rotary table. 1G is a moving table. Figure 1 (a) Figure 5 (a) Figure 5 (b) 21 jt>

Claims (1)

[Claims] A method of machining a scroll component in which a spiral wall of an involute curve of the scroll component is machined, the center position of a machining tool being moved on a straight line tangent to a base circle of the involute curve, while the scroll component is machined along the involute curve. A method for processing a scroll component, characterized in that the tool is rotated about the center of a base circle as the rotation center, and the linear movement of the tool and the rotation of the scroll component are mechanically synchronized at a constant ratio.