JP5310651B2 - Screw rotor manufacturing method and manufacturing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a quality of a screw rotor and shorten manufacturing time thereof in manufacturing the screw rotor, by machining a workpiece with a tool while moving the tool and the workpiece relative to each other. <P>SOLUTION: A method for manufacturing the screw rotor 2 includes a rough machining step S1 and finish machining steps S2 and S3. The rough machining step S1 performs rough machining of a spiral groove 11 on an outer diameter of the workpiece. The finish machining steps S2 and S3 perform finish machining of a side surface 13 and a bottom surface 14 of the spiral groove 11 after the rough machining step S1. In the finish machining steps S2 and S3, a side surface finishing tool 152 having a convexly curved round blade 152a at a tip end thereof is used to finish the side surface 13 together with a part of the bottom surface 14 adjacent to the side surface, and a bottom surface finishing tool 153 is used to finish a central part of the bottom surface 14. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to a method and an apparatus for manufacturing a screw rotor, and more particularly to a method and an apparatus for manufacturing a screw rotor of a screw compressor used as a refrigerant compressor or the like.

  Conventionally, there is a screw compressor used as a refrigerant compressor or the like shown in Patent Document 1 (International Publication No. 2004/089569). Such a screw compressor has a screw rotor in which a spiral groove that meshes with the gate rotor is formed. And a screw rotor is manufactured by processing a to-be-processed object with a tool, using an NC axis machine device, moving a tool and a to-be-processed object relatively. More specifically, the screw rotor is manufactured by roughing a spiral groove on the outer diameter of the workpiece and then finishing the spiral groove. Here, the finishing process is performed by cutting the side surface and the bottom surface of the spiral groove by a side surface finishing tool and a bottom surface finishing tool (that the tool itself does not rotate).

  However, in the above-described finishing of the spiral groove of the screw rotor, the bite tool for finishing the side surface of the spiral groove is different from the bite tool for finishing the bottom surface of the spiral groove. It is easy for processing residue to occur. In addition, since a bite tool is used for finishing, it is necessary to repeatedly cut the side surface and bottom surface of the spiral groove several times, which increases the processing time for finishing.

  For this reason, it is desired to improve the quality by eliminating the remaining processing of the seam between the side surface and the bottom surface of the spiral groove and to shorten the processing time of the finishing process.

  An object of the present invention is to improve the quality of a screw rotor and shorten the processing time in the manufacture of a screw rotor by manufacturing the screw rotor by processing the workpiece with the tool while relatively moving the tool and the workpiece. There is to plan.

  A screw rotor manufacturing method according to a first aspect is a screw rotor manufacturing method for manufacturing a screw rotor by processing a workpiece with a tool while relatively moving the tool and the workpiece. It has a processing step and a finishing processing step. The roughing step is a step of roughing the spiral groove on the outer diameter of the workpiece. The finishing step is a step of finishing the side surface and the bottom surface of the spiral groove after the roughing step. In the finishing step, a side finishing tool comprising a rotary tool having a curved R blade at the tip is used to finish the side surface together with a portion near the side of the bottom surface, and the bottom finishing tool is used to finish the bottom surface. Finish the center part. Here, the rotating tool means a tool that performs cutting by rotating the tool itself such as an end mill.

  In this screw rotor manufacturing method, the side surface finishing tool made of a rotary tool is used in the finishing process of the side surface of the spiral groove, so that it is not necessary to repeatedly cut the side surface of the spiral groove many times. For this reason, in the finishing process of the side surface of the spiral groove, the processing time of the finishing process of the side surface of the spiral groove can be shortened as compared with the case where a tool that does not rotate itself such as a conventional bite tool is used. . In addition, in this screw rotor manufacturing method, the side surface vicinity portion of the bottom surface is processed so as to be removed by the R blade of the side surface finishing tool. For this reason, it is difficult for processing residue to occur at the joint between the side surface and the bottom surface of the spiral groove, and the processing quality of the screw rotor can be improved. Further, in the finishing process of the bottom surface of the spiral groove, since the cutting range by the bottom surface finishing tool is only the center part of the bottom surface, the processing time of the finishing process of the bottom surface of the spiral groove can be shortened.

Moreover, in this screw rotor manufacturing method, the bottom finishing tool is a rotary tool having an R blade that is convexly curved at the tip and has the same radius as that of the central portion of the bottom surface of the spiral groove.

In this screw rotor manufacturing method, as described above, a side finishing tool having an R-blade is used in the finishing process of the side surface of the spiral groove. Therefore, in the finishing process of the bottom surface of the spiral groove, cutting is performed by the bottom finishing tool. The range to be done is limited to the central part of the bottom. For this reason, in finishing processing of the bottom surface of the spiral groove, it is not necessary to bring the bottom surface finishing tool close to the side surface of the spiral groove until it contacts the side surface of the spiral groove, and it is necessary to use a conventional bite tool as the bottom surface finishing tool. It is gone.

Therefore, in this screw rotor manufacturing method, as described above, a rotary tool having an R blade at the tip is used as the bottom finishing tool. For this reason, in the finishing process of the bottom surface of the spiral groove, it is possible to further shorten the processing time of the finishing process of the bottom surface of the spiral groove as compared with the case of using a conventional bite tool.

  The screw rotor manufacturing method according to the second aspect is the screw rotor manufacturing method according to the first aspect, wherein the radius of the R blade of the side finishing tool is smaller than the radius at the central portion of the bottom surface of the spiral groove. Here, the radius at the center portion of the bottom surface of the spiral groove means the radius at the center portion of the bottom surface of the spiral groove after finishing.

  In this method of manufacturing the screw rotor, it becomes easy to process so that a portion near the side surface of the bottom surface of the spiral groove in the central portion of the bottom surface of the spiral groove can be obtained. For this reason, it is possible to reliably prevent the remaining processing of the joint between the side surface and the bottom surface of the spiral groove.

A screw rotor manufacturing apparatus according to a third aspect is a screw rotor manufacturing apparatus that manufactures a screw rotor by processing a workpiece with a tool while relatively moving the tool and the workpiece. The workpiece support unit, the blade support unit, and the control unit are included. The workpiece support unit supports and moves the workpiece. The blade support portion supports and moves the tool. The control unit performs a roughing step for roughing the spiral groove on the outer diameter of the workpiece, and a finishing step for finishing the side surface and the bottom surface of the spiral groove after the roughing step. The workpiece is processed by the tool while the support portion and the blade support portion are relatively moved. In the finishing step, a side finishing tool comprising a rotary tool having a curved R blade at the tip is used to finish the side surface together with a portion near the side surface of the bottom surface, and the bottom finishing tool is used. Finish the center part of the bottom.

  In this screw rotor manufacturing apparatus, the side surface finishing tool made of a rotating tool is used in the finishing processing of the side surface of the spiral groove, so that it is not necessary to cut the side surface of the spiral groove repeatedly. For this reason, in the finishing process of the side surface of the spiral groove, the processing time of the finishing process of the side surface of the spiral groove can be shortened as compared with the case where a tool that does not rotate itself such as a conventional bite tool is used. . In addition, in this screw rotor manufacturing apparatus, the side surface vicinity portion of the bottom surface is processed by the R blade of the side surface finishing tool so as to be removed more than before. For this reason, it is difficult for processing residue to occur at the joint between the side surface and the bottom surface of the spiral groove, and the processing quality of the screw rotor can be improved. Further, in the finishing process of the bottom surface of the spiral groove, since the cutting range by the bottom surface finishing tool is only the center part of the bottom surface, the processing time of the finishing process of the bottom surface of the spiral groove can be shortened.

Moreover, in this screw rotor manufacturing apparatus, the bottom surface finishing tool is a rotary tool having an R blade that is convexly curved at the tip and has the same radius as the radius at the central portion of the bottom surface of the spiral groove.

In this screw rotor manufacturing apparatus, as described above, a side finishing tool having an R-blade is used for finishing the side surface of the spiral groove, so that the bottom finishing tool is used to cut the bottom surface of the spiral groove. The range to be done is limited to the central part of the bottom. For this reason, in finishing processing of the bottom surface of the spiral groove, it is not necessary to bring the bottom surface finishing tool close to the side surface of the spiral groove until it contacts the side surface of the spiral groove, and it is necessary to use a conventional bite tool as the bottom surface finishing tool. It is gone.

Therefore, in this screw rotor manufacturing apparatus, as described above, a rotary tool having an R blade at the tip is used as the bottom finishing tool. For this reason, in the finishing process of the bottom surface of the spiral groove, it is possible to further shorten the processing time of the finishing process of the bottom surface of the spiral groove as compared with the case of using a conventional bite tool.

The screw rotor manufacturing apparatus according to the fourth aspect is the screw rotor manufacturing apparatus according to the third aspect, wherein the radius of the R blade of the side finishing tool is smaller than the radius at the central portion of the bottom surface of the spiral groove.

  In this screw rotor manufacturing apparatus, it becomes easy to process so as to pass through the vicinity of the side surface of the bottom surface of the spiral groove in the central portion of the bottom surface of the spiral groove. For this reason, it is possible to reliably prevent the remaining processing of the joint between the side surface and the bottom surface of the spiral groove.

  According to the present invention, in finishing processing of the side surface of the spiral groove, the processing time of finishing processing of the side surface of the spiral groove is shortened as compared with the case where a tool such as a conventional tool that does not rotate itself is used. be able to. Moreover, it is difficult for processing residue to occur at the joint between the side surface and the bottom surface of the spiral groove, and the processing quality of the screw rotor can be improved.

It is a perspective view which shows the principal part of a screw compressor. It is sectional drawing of a screw rotor. It is the schematic which looked at the screw rotor manufacturing apparatus from the Z-axis direction front. It is the schematic which looked at the screw rotor manufacturing apparatus from the X-axis direction side. It is the schematic which looked at the screw rotor manufacturing apparatus from the Y-axis direction upper direction. It is a block diagram which shows the principal part of the control part of a screw rotor manufacturing apparatus. It is a flowchart which shows the manufacturing process of the spiral groove of the screw rotor concerning 1st Embodiment. It is a figure which shows the process of the spiral groove of the screw rotor concerning 1st Embodiment, Comprising: It is a figure which shows the spiral groove after rough machining. It is a figure which shows the manufacturing process of the spiral groove of the screw rotor concerning 1st Embodiment, Comprising: It is a figure which shows the spiral groove after the side surface finishing process. It is a figure which shows the manufacturing process of the helical groove | channel of the screw rotor concerning 1st Embodiment, Comprising: It is a figure which shows the helical groove | channel after the finishing process of a side surface and a bottom face. It is a figure which shows the spiral groove after the finishing process of the conventional screw rotor. It is a figure which shows the state which looked at the mode at the time of the finishing process of the bottom face of a screw rotor from the tool side. It is a simulation result which shows the state after the finishing process of the spiral groove by the difference in the blade shape at the front-end | tip of a side finishing tool.

  The manufacturing method and manufacturing apparatus of the screw rotor concerning this invention are demonstrated based on drawing.

<Configuration of screw compressor>
FIG. 1 is a perspective view showing a main part of the screw compressor 1. FIG. 2 is a cross-sectional view of the screw rotor 2. Here, the screw compressor 1 is a single screw compressor used as a refrigerant compressor for compressing a refrigerant.

  The screw compressor 1 mainly includes a screw rotor 2, a casing (not shown) that houses the screw rotor 2, a shaft 4 that serves as a rotation shaft of the screw rotor 2, gate rotors 5 and 6, a gate rotor 5, 6 and rotation shafts 8 and 9.

  The screw rotor 2 is a columnar rotor having a plurality of spiral spiral grooves 11 on the outer peripheral surface. The screw rotor 2 is integrated with the shaft 4 and can be rotated inside the casing. One end of the shaft 4 is connected to a drive motor (not shown).

  Each of the gate rotors 5 and 6 is a rotating body having a plurality of teeth 12 meshing with the spiral groove 11 of the screw rotor 2, and can be rotated around rotating shafts 8 and 9 substantially orthogonal to the shaft 4. The gate rotors 5 and 6 are disposed at positions symmetrical with respect to the rotation center of the screw rotor 2. When the screw rotor 2 rotates, the teeth 12 of the gate rotors 5 and 6 are sequentially engaged with the spiral groove 11.

  Further, the casing is provided with a suction port (not shown) for sucking the refrigerant into the casing and a discharge port (not shown) for discharging the refrigerant compressed inside the casing. .

<Operation of screw compressor>
First, when the shaft 4 receives a rotational force from a drive motor outside the casing, the screw rotor 2 rotates in the direction of the arrow R1 as shown in FIG. At this time, the gate rotors 5 and 6 meshing with the spiral groove 11 of the screw rotor 2 rotate in the direction of the arrow R <b> 2 when these teeth 12 are pushed by the side surface 13 of the spiral groove 11. At this time, in the screw rotor 2, the groove volume of the spiral groove 11 is expanded, and the refrigerant is sucked into the spiral groove 11 through the suction port. Then, as the rotation of the screw rotor 2 proceeds, the spiral groove 11 is confined by the teeth 12 of the gate rotors 5 and 6 when the groove volume of the spiral groove 11 of the screw rotor 2 is maximized. Further, as the rotation of the screw rotor 2 proceeds, the groove volume of the spiral groove 11 of the screw rotor 2 decreases, and the refrigerant is compressed and discharged through the discharge port.

<The manufacturing method and manufacturing apparatus of the screw rotor concerning 1st Embodiment>
-Manufacturing method and manufacturing apparatus of screw rotor-
Next, 1st Embodiment of the screw rotor manufacturing apparatus 100 for manufacturing the screw rotor 2 which comprises said screw compressor 1 is described using FIGS. 3-10. Here, FIG. 3 is a schematic view of the screw rotor manufacturing apparatus 100 as viewed from the front in the Z-axis direction. FIG. 4 is a schematic view of the screw rotor manufacturing apparatus 100 as viewed from the side in the X-axis direction. FIG. 5 is a schematic view of the screw rotor manufacturing apparatus 100 as viewed from above in the Y-axis direction. FIG. 6 is a block diagram illustrating a main part of the control unit 140 of the screw rotor manufacturing apparatus 100. FIG. 7 is a flowchart showing the processing steps of the spiral groove 11 of the screw rotor 2. FIG. 8 is a diagram showing a processing step of the spiral groove 11 of the screw rotor 2 and shows the spiral groove 11 after roughing. FIG. 9 is a diagram illustrating a processing step of the spiral groove 11 of the screw rotor 2 and is a diagram illustrating the spiral groove 11 after the side surface 13 is finished. FIG. 10 is a diagram illustrating a process of processing the spiral groove 11 of the screw rotor 2 and is a diagram illustrating the spiral groove 11 after finishing the side surface 13 and the bottom surface 14.

  The screw rotor manufacturing apparatus 100 mainly includes a blade support part 110, a workpiece support part 120, a foundation stand 130, and a control part 140.

  The blade support part 110 is a part that supports and moves the tool. The blade support part 110 mainly has a column 111 provided on the foundation stand 130 and a spindle part 112 attached to the column 111. The column 111 is a portion that is slidably attached to a Z-axis guide rail 131 provided on the upper surface of the base stand 130, and is movable in the Z-axis direction in which the Z-axis guide rail 131 extends. Here, the Z-axis extends in the horizontal direction. The column 111 moves while being positioned in the Z-axis direction by a servo motor (not shown). A Y-axis guide rail 113 extending along the Y-axis is provided on the surface of the column 111 that faces the workpiece support 120. Here, the Y-axis extends in the vertical direction. The spindle portion 112 mainly has a base portion 114, a spindle main body 115, and a tool holder 116. The base portion 114 is a portion that is slidably attached to the Y-axis guide rail 113 of the column 111. The base portion 114 is a portion that moves while being positioned in the Y-axis direction by a servo motor (not shown). The spindle body 115 is a portion provided on the base portion 114, and a tool holder 116 is detachably attached thereto. Further, the spindle body 115 is provided with a motor (not shown), and the tool holder 116 can be rotated at a desired rotational speed by this motor. The tool holder 116 is a part that supports the tool. The tool supported by the tool holder 116 can be changed by an automatic tool changer (not shown). In such a blade support unit 110, the servo motors of the column 111 and the base unit 114 are driven and controlled in accordance with a control signal from the control unit 140, and the tool is moved to the desired Y-axis direction position and Z-axis direction position. It is designed to be positioned. Further, the motor of the spindle main body 115 is driven and controlled in accordance with a control signal from the control unit 140, and the tool is driven to rotate or is supported so as not to rotate.

  The workpiece support 120 is a portion that supports and moves the workpiece. The workpiece support unit 120 mainly includes a rotary table 121, a clamp unit 122, and a center 123. The turntable 121 is a portion provided so as to be rotatable with respect to the base stand 130. The turntable 121 mainly has a base portion 124 and a turntable 125. The base portion 124 is a portion that is provided on the upper surface of the base stand 130 and is slidably attached to an X-axis guide rail 132 that extends in the X-axis direction (a direction orthogonal to the Y-axis and the Z-axis). The turntable 125 is a part attached to the base portion 124 so as to be rotatable about a vertical axis B extending in the vertical direction. The base portion 124 moves while being positioned in the X-axis direction by a servo motor (not shown). The turntable 125 rotates while the rotation angle about the vertical axis B is positioned by a motor (not shown). The clamp part 122 is a part that is provided on the rotary table 121 and clamps the workpiece. The clamp part 122 rotatably supports the workpiece around a horizontal axis A extending in the horizontal direction. Here, the horizontal axis A intersects the vertical axis B that is the rotation center of the turntable 125. The clamp part 122 rotates the workpiece while positioning the rotation angle around the horizontal axis A by a motor (not shown). The center 123 is a part that is provided on the rotary table 121 and supports the rotation center of the workpiece supported by the clamp part 122. The center 123 is a portion that can slide along the horizontal axis A on the rotary table 121. The center 123 is configured to come into contact with the rotation center of the workpiece supported by the clamp portion 122 from the front end side of the workpiece. The center 123 is center-pressed at the center of rotation at the free end of the workpiece clamped in a cantilevered manner by the clamp portion 122, thereby causing shaft blurring when the workpiece is rotationally driven around the horizontal axis A. It is preventing. In such a workpiece support unit 120, the servo motor of the rotary table 121 is driven and controlled in accordance with a control signal from the control unit 140 so that the workpiece is positioned at a desired X-axis direction position. It has become. Further, the motors of the rotary table 121 and the clamp unit 122 are driven and controlled in accordance with a control signal from the control unit 140 so that the workpiece is positioned around the vertical axis B and the horizontal axis A. .

  As described above, the screw rotor manufacturing apparatus 100 controls the tool along the Y axis and the Z axis mainly by controlling the blade support part 110 and the workpiece support part 120 in accordance with the control signal from the control part 140. The workpiece is linearly moved along the X axis, and the workpiece is rotated about the horizontal axis A and the vertical axis B (that is, the tool and the workpiece are relatively moved). ), The workpiece is processed into the screw rotor 2 with a tool.

  The control unit 140 mainly includes a tool path setting unit 141, an NC data creation unit 142, and an output unit 143. The tool path setting unit 141 is a part for setting target tool path data. More specifically, the tool path setting unit 141 receives the design data of the spiral groove 11 of the screw rotor 2, the shape of the workpiece before machining, and the like, and the tool for the workpiece based on these design data and the like. The target tool path data is calculated and set. Here, the target tool path data is data relating to the position and orientation of the tip of the tool with respect to the workpiece during machining and the movement path. The NC data creation unit 142 is a part that mainly creates NC data for controlling the blade support unit 110 and the workpiece support unit 120. More specifically, the NC data creation unit 142 creates NC data for driving the blade support unit 110 and the workpiece support unit 120 based on the target tool path data set by the tool path setting unit 141. To do. The NC data includes position command data for three orthogonal axes (X axis, Y axis, and Z axis) in the screw rotor manufacturing apparatus 100, position command data for two rotation axes (horizontal axis A and vertical axis B), and the like. The output unit 143 is a part that outputs NC data to the blade support unit 110 and the workpiece support unit 120. More specifically, the output unit 143 outputs a control signal to the motor and the like of the blade support unit 110 and the workpiece support unit 120 based on the NC data from the NC data creation unit 142.

  Then, when a control signal is input from the output unit 143 to the motors of the blade support unit 110 and the workpiece support unit 120, the tool support unit 110 and the workpiece support unit 120 move, and the tool is moved to the workpiece. On the other hand, the spiral groove 11 is machined in the workpiece while moving along a desired target tool path. More specifically, the processing of the spiral groove 11 is mainly performed in the order of the roughing step S1, the finishing step S2, and S3.

  The roughing step S1 is a step of roughing the spiral groove 11 on the outer periphery of the workpiece. In the roughing step S1, a roughing tool 151 composed of an end mill as a rotary tool (a tool that performs cutting by rotating the tool itself) is used as a tool. First, the roughing tool 151 is attached to the spindle portion 112 via the tool holder 116. Then, the spiral groove 11 is cut into the workpiece by the roughing tool 151. At this time, a target tool path for roughing is set as the target tool path of the roughing tool 151, and the blade support part 110 and the workpiece support part 120 are driven in accordance with the target tool path for roughing. The In addition, the solid line in FIG. 8 has shown the shape of the spiral groove 11 actually processed into a workpiece, and the broken line in FIG. 8 has shown the shape of the spiral groove 11 after finishing.

  Finishing steps S2 and S3 are steps for finishing the side surface 13 and the bottom surface 14 of the spiral groove 11 after the roughing step S1. In the finishing step S2 of the side surface 13, a side finishing tool 152 made of an end mill as a rotary tool is used as a tool. The side finishing tool 152 has an R blade 152a that is convexly curved at the tip. That is, the side finishing tool 152 is a rotary tool with an R blade 152a. Here, the radius r1 of the R blade 152a is smaller than the radius r2 of the center portion of the bottom surface 14 after finishing. Here, the radius r1 of the R blade 152a is set to be 0.7 times or more and less than 1.0 times the radius r2 of the center portion of the bottom surface 14 after finishing. First, the side finishing tool 152 is attached to the spindle portion 112 via the tool holder 116. Then, the side surface 13 of the spiral groove 11 is cut together with the vicinity of the side surface of the bottom surface 14 by the side surface finishing tool 152. More specifically, the target tool path for the side finishing machining is set as the target tool path for the side finishing machining, and the tool support unit 110 and the workpiece support are supported according to the target tool path for the side finishing machining. The unit 120 is driven. Here, the target tool path for the side finishing process is such that the portion near the side surface of the bottom surface 14 maintains the bottom surface 14 after the finishing processing and the radius r2 of the center portion thereof by the R blade 152a of the side finishing tool 152. The path is set so as to be removed from a line extending in the lateral direction (see a two-dot chain line in FIGS. 8 to 10). Next, in the finishing step S3 of the bottom surface 14, a bottom surface finishing tool 153 composed of an end mill as a rotary tool is used as a tool. The bottom finishing tool 153 has an R blade 153a that is curved in a convex shape at the tip. That is, the bottom finishing tool 153 is a rotary tool with an R blade 153a. Here, the radius r3 of the R blade 153a is the same as the radius r2 of the center portion of the bottom surface 14 after finishing. First, the bottom finishing tool 153 is attached to the spindle portion 112 via the tool holder 116. Then, the center portion of the bottom surface 14 of the spiral groove 11 is cut by the bottom finishing tool 153. More specifically, the target tool path for the bottom surface finishing machining is set as the target tool path for the bottom surface finishing machining, and the blade support unit 110 and the workpiece support according to the target tool path for the bottom surface finishing machining. The unit 120 is driven. Here, the target tool path for bottom surface finishing is set to a path in which only the center portion of the bottom surface 14 is cut by the bottom surface finishing tool 153.

-Features of screw rotor manufacturing method and manufacturing equipment-
The manufacturing method and the manufacturing apparatus 100 of the screw rotor 2 of this embodiment have the following characteristics.

  First, in the manufacturing method and the manufacturing apparatus 100 of the screw rotor 2 according to the present embodiment, the side surface finishing tool 152 made of a rotary tool is used in the finishing processing of the side surface 13 of the spiral groove 11, and thus the side surface 13 of the spiral groove 11. It is no longer necessary to cut repeatedly. For this reason, in the finishing process of the side surface 13 of the spiral groove 11, the processing time of the finishing process of the side surface 13 of the spiral groove 11 can be shortened compared to the case where a tool that does not rotate itself such as a conventional bite tool is used. Can be planned.

  Further, in the conventional screw rotor manufacturing method and manufacturing apparatus, in the finishing of the spiral groove of the screw rotor, the bite tool that finishes the side surface of the spiral groove is different from the bite tool that finishes the bottom surface of the spiral groove. As shown in FIG. 11, the processing residue is likely to occur at the joint between the side surface and the bottom surface of the spiral groove. However, in the manufacturing method of the screw rotor 2 according to the present embodiment, the R blade 152a of the side finishing tool 152 keeps the bottom surface 14 of the bottom surface 14 in the vicinity of the side surface while maintaining the radius r2 of the center portion of the bottom surface 14 after finishing. It is processed so that it can be removed from the line extended in the side direction. For this reason, it is difficult for processing residue to occur at the joint between the side surface 13 and the bottom surface 14 of the spiral groove 11, and the processing quality of the screw rotor 2 can be improved. In addition, since the radius r1 of the R blade 152a of the side finishing tool 152 is smaller than the radius r2 at the center portion of the bottom surface 14 of the spiral groove 11, the spiral groove at the center portion of the bottom surface 14 of the spiral groove 11 is used here. It is easy to process so that the part near the side surface of the bottom surface 14 of 11 can be obtained. For this reason, it is possible to reliably prevent the remaining processing of the seam between the side surface 13 and the bottom surface 14 of the spiral groove 11.

  Further, in the manufacturing method and the manufacturing apparatus 100 of the screw rotor 2 according to the present embodiment, in the finishing process of the bottom surface 14 of the spiral groove 11, only the central portion of the bottom surface 14 needs to be cut by the bottom finishing tool 153. The processing time for finishing the bottom surface 14 of 11 can be shortened.

  Further, in the conventional screw rotor manufacturing method and manufacturing apparatus, in the finishing process of the spiral groove of the screw rotor, a rotating tool is not used as a bottom finishing tool, and a bite tool is used. Because the spiral groove of the screw rotor is inclined when viewed from the tool side (X-axis direction in FIGS. 3 to 5), as shown in FIG. This is because the rotary tool comes into contact with the side surface of the spiral groove before cutting the vicinity of the side surface of the bottom surface. However, in the manufacturing method and the manufacturing apparatus 100 of the screw rotor 2 of the present embodiment, as described above, in the finishing process of the bottom surface 14 of the spiral groove 11, the range to be cut by the bottom finishing tool 153 is only the central portion of the bottom surface 14. It has come to be finished. For this reason, in the finishing process of the bottom surface 14 of the spiral groove 11, it is not necessary to bring the bottom surface finishing tool close to the side surface of the spiral groove until it contacts the side surface 13 of the spiral groove 11, and a conventional bite tool is used as the bottom surface finishing tool. No longer need to use. Therefore, in the manufacturing method and the manufacturing apparatus 100 of the screw rotor 2 of the present embodiment, a rotary tool having an R blade 153a at the tip is used as the bottom finishing tool 153. For this reason, in the finishing process of the bottom surface 14 of the spiral groove 11, the processing time of the finishing process of the bottom surface 14 of the spiral groove 11 can be further shortened compared with the case where a conventional bite tool is used.

  In addition, according to the manufacturing method and manufacturing apparatus 100 of the screw rotor 2 of this embodiment, as shown in FIG. 13, the shape of the bottom face 14 of the spiral groove 11 is a rotary tool with an R blade (that is, a bottom finishing tool 153). The processing line for finishing the bottom surface 14 (see the thick solid line in FIG. 13) and the processing line for finishing the side surface 13 with the R-bladed rotary tool (that is, the side finishing tool 152) (see the thin solid line in FIG. 13). And is a composite. That is, the processing line for finishing the side surface 13 by the side surface finishing tool 152 is the bottom surface by the bottom surface finishing tool 153 at a position closer to the center line (see FIG. 10) than the limit position where the bottom surface 14 can be finished by the rotating tool. It is connected to 14 finishing lines. For this reason, it can be seen that the portion near the side surface of the bottom surface 14 is processed so as to be slightly removed from the design ideal line of the bottom surface 14 of the spiral groove 11 (see the thin one-dot chain line in FIG. 13). The depth of the bottom surface 14 is about 20 μm in the spiral groove in which r2 of the bottom surface 14 is about 100 mm and the groove width between the side surfaces 13 is about 30 mm. On the other hand, when a rotary tool without an R blade (that is, a rotary tool with a flat tip without the R blade 152a) is used as a side finishing tool, the same side direction position as that when a rotary tool with an R blade is used. When the bottom finishing tool 153 is connected to the finishing line of the bottom surface 14, the portion near the side surface of the bottom surface 14 is the design ideal line of the bottom surface 14 of the spiral groove 11 (see the thin one-dot chain line in FIG. 13). It can be seen that processing must be carried out so as to be very large (see the two-dot chain line in FIG. 13). The depth of the bottom surface 14 is about 100 μm in the spiral groove in which r2 of the bottom surface 14 is about 100 mm and the groove width between the side surfaces 13 is about 30 mm. Thus, according to the manufacturing method and the manufacturing apparatus 100 of the screw rotor 2 of this embodiment, since the rotary tool with R blade is used as the side finishing tool, the side surface of the bottom surface 14 is close to the design ideal line. A rotary tool can be used as a bottom finishing tool while machining the neighboring portion slightly.

<Other embodiments>
As mentioned above, although embodiment of this invention was described based on drawing, specific structure is not restricted to said embodiment, It can change in the range which does not deviate from the summary of invention.

  In the screw rotor manufacturing apparatus according to the above embodiment, as a configuration for moving the tool and the workpiece relative to each other, the tool is linearly moved along the Y axis and the Z axis, and the workpiece is linearly moved along the X axis. The configuration is adopted in which the workpiece is moved and the workpiece is rotated about the horizontal axis A and the vertical axis B. However, the present invention is not limited to this. For example, the tool may be rotated about the vertical axis B, and the tool is not moved forward and backward with respect to the workpiece, but the tool is moved forward and backward with respect to the workpiece. You may make it make it.

  Moreover, in the manufacturing method of the screw rotor according to the above-described embodiment, the finishing process of the side surface 13 is performed after the finishing process of the side surface 13 in the finishing process of the spiral groove 11. However, the present invention is not limited thereto, and the side surface 13 may be finished after the bottom surface 14 is finished.

  The present invention is widely applicable to a method and an apparatus for manufacturing a screw rotor of a screw compressor used as a refrigerant compressor or the like.

DESCRIPTION OF SYMBOLS 2 Screw rotor 11 Spiral groove 13 Side surface 14 Bottom surface 100 Screw rotor manufacturing apparatus 110 Blade support part 120 Workpiece support part 140 Control part
152 Side finishing tool 152a, 153a R blade
153 Bottom finishing tool r1, r2, r3 radius
S1 roughing step
S2 and S3 finishing steps

International Publication No. 2004/089569

Claims (4)

A screw rotor manufacturing method for manufacturing a screw rotor (2) by processing the workpiece with the tool while relatively moving the tool and the workpiece,
A roughing step (S1) for roughing the spiral groove (11) on the outer diameter of the workpiece;
A finishing step (S2, S3) for finishing the side surface (13) and the bottom surface (14) of the spiral groove after the roughing step;
In the finishing step, the side surface is finished together with a portion near the side surface of the bottom surface by using a side surface finishing tool (152) made of a rotary tool having an R blade (152a) curved convexly at the tip, A bottom finishing tool (153) comprising a rotating tool having an R blade (153a) having a radius (r3) that is the same as the radius (r2) in the central portion of the bottom surface of the spiral groove. Finishing the central part of the bottom surface,
A manufacturing method of a screw rotor.   The screw (1) according to claim 1, wherein a radius (r1) of an R blade (152a) of the side finishing tool (152) is smaller than a radius (r2) in a central portion of a bottom surface (14) of the spiral groove (11). A method for manufacturing a rotor. A screw rotor manufacturing apparatus that manufactures a screw rotor (2) by processing the workpiece with the tool while relatively moving the tool and the workpiece,
A workpiece support (120) for supporting and moving the workpiece;
A blade support (110) for supporting and moving the tool;
A roughing step for roughing the spiral groove (11) to the outer diameter of the workpiece, and a finishing step for finishing the side surface (13) and the bottom surface (14) of the spiral groove after the roughing step. A control unit (140) that causes the tool to process the workpiece while moving the workpiece support and the blade support relative to each other.
In the finishing step, the side surface is finished together with a portion near the side surface of the bottom surface by using a side surface finishing tool (152) made of a rotary tool having an R blade (152a) curved convexly at the tip, A bottom finishing tool (153) comprising a rotary tool having an R blade (153a) having a radius (r3) equal to the radius (r3) at the central portion of the bottom surface of the spiral groove. Finishing the central part of the bottom surface,
Screw rotor manufacturing apparatus (100).   The screw (1) according to claim 3, wherein the radius (r1) of the R blade (152a) of the side finishing tool (152) is smaller than the radius (r2) at the central portion of the bottom surface (14) of the spiral groove (11). A rotor manufacturing apparatus (100).

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