JP3622432B2 - Top surface processing method of scroll parts - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of processing an upper surface which is a release side of a scroll component composed of two parts of a central involute-shaped scroll plate portion and an outer portion of a non-involute shape outside thereof.
[0002]
[Prior art]
A scroll compressor used for an air conditioner or the like is, for example, as shown in a top view in FIG. 3, a fixed scroll component comprising two parts, a central involute-shaped scroll plate portion 11 and an outer non-involute-shaped outer portion 12. 10 is used as a housing. The fixed scroll component 10 is opened on one side in the direction of the central axis O in order to insert a movable scroll component that makes a revolving motion, and the contour of the outer portion 12 partially protrudes to provide a cover mounting hole 13. It has a shape with a part.
[0003]
In the fixed scroll component 10, the inner wall surface 11a and the outer wall surface 11b of the scroll plate portion 11 are separately processed by a reciprocating path of the same end mill, and the bottom surface 11c between the wall surfaces 11a and 11b facing each other simultaneously is also the end mill. It is processed by the tip. The top surfaces of the scroll plate portion 11 and the outer portion 12 are also machined. In order to ensure the accuracy of the height from the bottom surface 11c to the top surface, these processes are performed by the same processing machine with the chuck of the fixed scroll component 10. Without removing the king, the inner and outer wall surfaces 11a and 11b and the bottom surface 11c are processed using the same end mill tips.
[0004]
The upper surface is processed along the same inner processing path La as the involute shape of the scroll plate portion 11 from the center processing start point SP to the switching point IP at which the involute shape of the scroll plate portion 11 ends. In order to minimize the length of the machining locus from the switching point IP to the machining end point EP in the outer side portion 12 with the target protrusion, as shown in FIG. 3, a plurality of points passing through the points (corner portions) CP1 to CP6. This is performed along the refracted outer processing path Lb composed of the arc-shaped paths Lb1, Lb3, Lb5, Lb7 and the linear paths Lb2, Lb4, Lb6. More specifically, the machining along the involute-shaped inner machining path La is performed by rotating the fixed scroll component 10 around the central axis O of the involute-shaped base circle (not shown) and the end mill in a direction perpendicular to the central axis O. The processing along the refracted outer processing path Lb is performed by stopping the rotation of the fixed scroll component 10 and moving the end mill 27 in the X and Y directions perpendicular to the central axis O. Note that the first path Lb1 from the switching point IP to the first corner portion CP1 calculates the distance from the central axis O to the point on the first path Lb1 every 90 degrees of phase angle, and smoothly smoothes these points. It is composed of a plurality of arcs calculated to be connected.
[0005]
[Problems to be solved by the invention]
In such a conventional technique, the feed direction of the tool spindle 26 is suddenly reversed at each corner portion CP1 to CP6 of the outer machining path Lb. Therefore, at each corner portion CP1 to CP6, the feed speed of the tool spindle 26 is once near zero. And then accelerated again to the desired feed rate, thus lowering the average feed rate. Further, the maximum command value of the feed speed of the tool in the X direction and the Y direction in the outer machining path Lb is normally limited to about 8 m / min for control reasons, so the average feed speed is about 4 to 5 m / min. It becomes. For this reason, there is a problem that the machining time increases despite the shortening of the length of the machining locus.
An object of the present invention is to solve such a problem and shorten the processing time.
[0006]
[Means for Solving the Problems]
The method of processing the top surface of a scroll component according to the present invention comprises an involute-shaped base circle consisting of two parts, a central involute-shaped scroll plate portion and a non-involute-shaped outer portion outside the center of the rotating workpiece spindle. Grip the fixed scroll part with one side in the center axis direction released so that the center axis of the base circle is parallel to the rotation axis of the workpiece spindle,
A tool having a rotation axis parallel to the workpiece spindle is moved relative to the fixed scroll component in a direction perpendicular to the rotation axis of the workpiece spindle so as to machine the upper surface on the released side of the fixed scroll component. Related to the top surface processing method of the scroll parts,
In the entire machining range of the scroll plate and the upper surface of the outer part, the work spindle that holds the fixed scroll part is continuously rotated in one direction, and the tool has a substantial machining path for the fixed scroll part. And moving in a direction perpendicular to the central axis of the workpiece spindle so as to form a continuous spiral shape.
[0007]
The top surface of the scroll plate part is processed from the inside to the outside along the involute-shaped inner processing path, and the upper surface of the outer part is a spiral shape that is substantially continuous with the inner processing path so as to process the entire processing area. It is preferable to process along the outer processing path.
[0008]
Through the machining of both the scroll plate portion and the outer portion, it is preferable that the rotational feed direction of the fixed scroll component and the feed direction in the direction perpendicular to the central axis of the workpiece main axis of the tool do not change.
[0009]
The tool for processing the upper surface of the fixed scroll component is preferably an end mill for processing the inner wall surface and the outer wall surface of the scroll plate portion, and the bottom surface between the opposing wall surfaces.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
A method for processing the top surface of the scroll component according to the present invention will be described below from the embodiment shown in FIGS.
FIG. 1 shows a top view of a fixed scroll component 10 machined according to the present invention. This fixed scroll component 10 is exactly the same in use and shape as that processed by the prior art shown in FIG. 3, and is composed of a scroll plate portion 11 having a central involute shape and an outer portion 12 having a non-involute shape outside thereof. It consists of a part and one side is released. The inner wall surface 11a and the outer wall surface 11b of the scroll plate portion 11 are the same involute-shaped surfaces and are shifted in phase around the central axis O of the base circle. Both the wall surfaces 11a and 11b face each other. The bottom surface 11c between 11a and 11b and the top surfaces of the scroll plate portion 11 and the outer portion 12 are machined by the same end mill 27.
[0011]
FIG. 2 shows a scroll processing machine for processing the fixed scroll component 10. A table 22 guided and supported by an X-axis guide table 21 fixed on a bed 20 of a scroll processing machine so as to be movable in the horizontal X direction is reciprocated by a servo motor 23, and its position is detected by an encoder 24. A tool spindle 26 is pivotally supported on a spindle stock 25 fixed on the table 22 so as to be rotatable about an axis parallel to the horizontal Z direction orthogonal to the X direction, and is rotated by a motor (not shown). An end mill 27 for processing the fixed scroll component 10 is attached to the tip of the tool spindle 26.
[0012]
A column 31 guided and supported by a Z-axis guide stand 28 fixed on the bed 20 on the front surface of the tool spindle 26 so as to be movable in the Z direction is reciprocated by a servo motor 29, and its position is detected by an encoder 30. The workpiece spindle head 34 guided and supported by the column 31 so as to be movable in the vertical Y direction is reciprocated by a servo motor 32, and its position is detected by an encoder 33. A workpiece spindle 35 is supported on the workpiece spindle head 34 so as to be rotatable about an axis C parallel to the Z direction, and is rotated by a servo motor (not shown). A chuck 36 for detachably holding the fixed scroll component 10 is provided.
[0013]
A numerical control device 40 for controlling the operation of the scroll machine has a central processing unit 41 and a memory 42 as main components. The central processing unit 41 operates the servo motors 23, 29, 32 and the like described above via the interface 44 and the drive units 47, 48, 49 so that the operation described below is performed, so that the table 22, the column 31 are operated. Then, the workpiece spindle head 34 is moved, and the positions of the table 22, the column 31 and the workpiece spindle head 34 detected by the encoders 24, 30, 33 are fed back to the central processing unit 41 via the interface 44. An input device 45 for inputting necessary data and commands and an output device 46 for displaying are connected to the central processing unit 41 via an interface 43.
[0014]
Next, processing of the fixed scroll component 10 by the scroll processing machine will be described. First, processing of the inner and outer wall surfaces 11a, 11b and the bottom surface 11c of the scroll plate portion 11 of the fixed scroll component 10 will be described. First, in the fixed scroll component 10, the center axis O of the involute-shaped base circle of both wall surfaces 11a and 11b of the scroll plate portion 11 coincides with the rotation axis C of the work spindle 35, and the released upper surface is the end mill 27 (tool). 27) The tip of the workpiece spindle 35 is held by the chuck 36 so as to be on the side. The numerical control device 40 controls the servo motors 23, 29, and 32 to offset the rotation axis C of the work spindle 35 with respect to the rotation axis of the end mill 27 in the vertical direction by the radius of the base circle. With the rotation of the workpiece spindle 35 stopped at the machining start phase and the end mill 27 rotated, the table 22 is positioned in the X direction so that the end mill 27 is positioned at the machining start point SP, and the column 31 is advanced. The end mill 27 is fed into the fixed scroll component 10 to a predetermined depth.
[0015]
Next, the numerical controller 40 gives the workpiece spindle 35 a rotational feed in the clockwise direction in FIG. 1 by a servo motor (not shown), and in association with this, the servo motor 23 gives the end mill 27 in the X direction in FIG. A movement feed in the right direction is given to process the inner wall surface 11a and the majority of the bottom surface 11c on the side. When the end mill 27 reaches the switching point IP of the scroll plate portion 11, the numerical controller 40 positions the table 22 in the X direction so that the end mill 27 is in a position to cut into the outer wall surface 11b of the scroll plate portion 11, and the workpiece spindle. The remaining portions of the outer wall surface 11b and the bottom surface 11c of the scroll plate part 11 are machined with the rotation feed of 35 and the movement feed of the end mill 27 reversed, reaching the machining start point SP and reaching the inner end of the scroll plate part 11. When the machining is finished, the rotational feed and the moving feed are stopped, the column 31 is moved backward by the servo motor 29, and the end mill 27 is pulled out from the fixed scroll component 10. Thereby, the processing of the inner and outer wall surfaces 11a and 11b and the bottom surface 11c of the scroll plate portion 11 is completed.
[0016]
Subsequent processing of the upper surface of the fixed scroll component 10 includes processing of the upper surface of the scroll plate portion 11 along the inner processing path La from the processing start point SP to the switching point IP, and from the switching point IP to the processing end point EP. The processing is performed on the upper surface of the outer portion 12 along the outer processing path Lb. The inner machining path La is a path along an involute shape that is intermediate between both wall surfaces 11 a and 11 b of the scroll plate portion 11, and the outer machining path Lb is a spiral path that processes the entire machining area of the upper surface of the outer portion 12. It is.
[0017]
In machining along the inner machining path La, first, the numerical control device 40 moves the end mill 27 in the X direction by the servo motor 23 and rotates the fixed scroll component 10 as necessary, so that the center of the end mill 27 is aligned with the inner machining path La. A machining start point SP that does not overlap the scroll plate portion 11 on the extension of the involute shape is set, and the column 31 is advanced by the servo motor 29 so that the tip of the end mill 27 is a predetermined distance from the bottom surface 11c between the wall surfaces 11a and 11b. Position so that. Next, the numerical controller 40 gives the workpiece spindle 35 a rotational feed in the clockwise direction in FIG. 1 by a servo motor (not shown), and in connection with this, the servo motor 23 gives the end mill 27 the X-direction fixed scroll component 10 in the X direction. A moving feed in a direction away from the central axis O is given, a feed along the inner machining path La is given to the end mill 27, and the upper surface of the scroll plate portion 11 is machined by the tip of the end mill 27.
[0018]
When the end mill 27 reaches the switching point IP, the numerical control device 40 continues to provide the workpiece spindle 35 with a rotational feed in the clockwise direction, and to the end mill 27 with the X direction feed in the same direction as before. The upper surface of the outer portion 12 is processed along a substantially continuous spiral outer processing path Lb. The outer machining path Lb first calculates the distance from the central axis O necessary for machining the entire machining area of the upper surface of the outer portion 12 to a point on the outer machining path Lb for each phase angle of 90 degrees. Are formed by a plurality of arcs calculated so as to smoothly connect the points.
[0019]
Of the processing of the upper surface of the housing 10 performed as described above, the processing of the upper surface of the scroll plate portion 11 is not substantially different from the prior art described above. However, in the processing of the upper surface of the outer portion 12, the outer processing path Lb has a spiral shape that is substantially continuous with the inner processing path La. Therefore, unlike the prior art described above, the feed of the end mill 27 to the fixed scroll component 10 is performed. Rapid changes in speed and feed direction are eliminated. Further, since the distance from the central axis O of the fixed scroll component 10 is large in the outer portion 12, the rotational speed around the central axis O for control reasons is within the limit of the maximum command value (usually, for example, 300 rotations / min). The feed speed of the end mill 27 with respect to the housing 10 can be increased to, for example, about 50 m / min. As a result, the average feed speed of the end mill 27 is greatly increased, so that the machining time is greatly shortened.
[0020]
Further, in the above-described prior art, the processing of the upper surface of the outer portion 12 of the fixed scroll component 10 greatly changes the feed speed and feed direction of the end mill 27, and thereby the cutting resistance changes greatly. As a result, the processing accuracy of the upper surface of the outer portion 12 varies depending on the location. However, according to the above-described embodiment, since the change in the bending direction and the bending amount of the end mill 27 due to the cutting resistance is reduced by eliminating the abrupt changes in the feeding direction and the feeding speed of the end mill 27, the processing accuracy varies depending on the location. Also decreases.
[0021]
In the above-described embodiment, the center axis of the end mill 27 and the center axis O of the fixed scroll component 10 are offset in the Y direction by a distance corresponding to the radius of the involute base circle, so that each part of the fixed scroll component 10 is However, this is applied to the case of processing a normal involute scroll plate 11 having a constant base circle diameter. However, in order to increase the efficiency of the scroll compressor, it is preferable to use the scroll plate portion 11 having an involute shape in which the diameter of the base circle gradually increases. In this case, the end mill 27 is provided with an increase in the diameter of the base circle. A feed in the Y direction is also given, and the offset between the center axes of the end mill 27 and the fixed scroll component 10 may be increased in accordance with the rotation of the fixed scroll component 10. In any of the involute shapes, it is possible to perform machining without an offset between the center axis of the end mill 27 and the center axis O of the fixed scroll part 10, but the end mill 27 with respect to the rotational feed of the workpiece spindle 35 is possible. Therefore, it takes time to calculate the feed, and therefore, extra time is required for the control.
[0022]
The fixed scroll component 10 may be gripped by the work spindle 35 so that the center axis O of the involute-shaped base circle of the scroll plate portion 11 is parallel to the rotation axis C of the work spindle 35. It is only one of the parallel modes to hold the base axis O of the base circle so that it coincides with the rotation axis C of the workpiece spindle 35. Such matching makes it easy to calculate the feed of the end mill 27 with respect to the rotational feed of the workpiece spindle 35, and thus facilitates control.
[0023]
【The invention's effect】
According to the present invention, the fixed scroll component continuously rotates in one direction in the entire processing range of the upper surface, and the machining path of the tool with respect to the fixed scroll component becomes a substantially continuous spiral shape. There is no sudden change in the feed rate and feed direction of the tool with respect to. In addition, since the distance from the central axis of the fixed scroll component is large at the outer portion, the feed rate of the tool to the housing is large even within the limit of the maximum command value of the rotational speed around the central axis for control reasons. As a result, the average feed speed of the tool increases, so that the machining time is shortened.
[Brief description of the drawings]
FIG. 1 is a top view showing an embodiment of a top surface processing method of a scroll component according to the present invention.
FIG. 2 is a side view of a scroll processing machine used to implement the present invention.
FIG. 3 is a top view illustrating an example of a top surface processing method of a scroll component according to a conventional technique.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Fixed scroll component, 11 ... Scroll board part, 11a ... Inner wall surface, 11b ... Outer wall surface, 11c ... Bottom surface, 12 ... Outer part, 27 ... Tool (end mill), 35 ... Workpiece spindle, La ... Inner machining path, Lb ... outside machining path, O ... center axis.

Claims (4)

Fixed to the tip of the rotating work spindle, which is composed of two parts, a central involute scroll plate and a non-involute outer part on the outer side, and one side in the direction of the central axis of the involute base circle is released. The scroll component is gripped so that the central axis is parallel to the rotation axis of the workpiece spindle, and a tool having a rotation axis parallel to the workpiece spindle is rotated with respect to the fixed scroll component. In the top surface processing method of the scroll component, which is relatively moved in a direction orthogonal to the axis, to process the top surface on the released side of the fixed scroll component,
In the entire processing range of the upper surface of the scroll plate portion and the outer portion, the work spindle that grips the fixed scroll component is continuously rotated in one direction, and the tool is processed with respect to the fixed scroll component. An upper surface machining method for a scroll component, characterized by feeding and moving in a direction orthogonal to the central axis of the workpiece spindle so that a path is substantially continuous. The upper surface of the scroll plate portion is processed from the inner side to the outer side along the inner processing path of the involute shape, and the upper surface of the outer portion is substantially continuous with the inner processing path so as to process the entire processing area. The method of processing a top surface of a scroll component according to claim 1, wherein the processing is performed along a spiral outer processing path. Through the machining of both the scroll plate part and the outer part, the direction of rotational feed of the fixed scroll part and the direction of feed in the direction perpendicular to the central axis of the workpiece spindle of the tool do not change. The upper surface processing method of the scroll components of Claim 1 or Claim 2. The said tool which processes the upper surface of the said fixed scroll component is an end mill which processes the inner wall surface and outer wall surface of the said scroll board part, and the bottom face between these both wall surfaces which face each other. The upper surface processing method of the scroll components as described in a term.

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