JPH10286720A - Screw part working method of screw rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the machining time for the screw part of a screw rotor, by coaxially mounting a single cutter and a hob, on a hob main shaft, so that the roughing is performed by the single cutter, and the finishing is performed by the hob. SOLUTION: A screw cutting work of a screw part is performed on a work 14 by bringing the work 14 and a single cutter 12 into contact with each other, driving a rotary table 6, and further driving a saddle 3. When the roughing of all grooves has been finished, the finishing is started. In the finishing, a cross angle to the work 14, of the hob main shaft 9 is changed. A hob shift device 10 is controlled so that the hob 13 is located in opposition to the work 14. Then number of revolutions of the hob main shaft 9, number of revolutions of the rotary table 6, feeding speed of the saddle 3 or the like are fully automatically controlled, to perform the finishing of the screw part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing a screw portion of a screw rotor used for a screw compressor.

[0002]

2. Description of the Related Art Screw portions of a pair of male and female rotors (hereinafter referred to as "screw rotors") used in a screw compressor have been processed by a hobbing machine. That is, a work is mounted on a rotary table of a hob machine, and a cutting tool is mounted on a hob main shaft of a hob head.

[0003] As the cutting tools, there are a milling cutter provided with a cutting blade in a worm (hereinafter referred to as "hob") and a single-section cutter (hereinafter referred to as "single cutter"). In the processing using the single cutter, it is necessary to perform indexing for each groove of the screw portion of the screw rotor, and there is a problem that the indexing is troublesome.
Then, there is a problem that the product accuracy depends on the indexing accuracy. However, the single cutter was able to cut at a higher speed than the hob.

In the machining using the hob, all the grooves can be machined at the same time, so that it is not necessary to index the work, and high-accuracy machining is possible. However, since the cutting speed is low, there is a problem that the processing time is longer than that of the single cutter.

[0005]

Conventionally, a hob for roughing and a hob for finishing are mounted on a hob arbor attached to a main shaft of a hob, and the hob arbor is shifted in an axial direction to shorten the processing time. Was. However, since the hob is used for rough machining, the number of revolutions cannot be increased, and machining efficiency cannot be increased.

There is also a machining method in which roughing is performed by a single cutter and finishing is performed by a hob. However, since the single cutter and the hob have different mounting angles of a blade with respect to a work, they are performed by separate machines. This necessitated the necessity of changing the setup, and it was not possible to improve the processing efficiency. Further, it is conceivable to perform roughing and finishing with a single cutter, but in this case, roughing may be inaccurate, so that indexing can be performed in a short time. Since it has to be performed, it takes time to determine the index, and it is difficult to improve the processing efficiency.

In any case, it is difficult to improve the processing efficiency by the conventional processing method. An object of the present invention is to provide a new processing method capable of performing high-efficiency processing in order to solve such problems.

[0008]

In order to achieve the above object, the present invention takes the following measures. That is, the feature of the present invention is that in a method of processing a screw portion of a screw rotor using a single cutter and a hob by a hob machine, a single cutter and a hob are arranged on the same axis on a hob main shaft, The point is that roughing is performed by a single cutter and finishing is performed by a hob.

According to the above method, the indexing of the single cutter takes time, but since it is a rough machining, accurate indexing is not required. Therefore, there is no problem even if high-speed indexing is performed. , Roughing can be performed at high speed. On the other hand, in the finishing process, since it is processed by a hob, there is no need for indexing, and the process can be performed with high precision.

In the transition from roughing to finishing, the single cutter and the work were opposed to each other until then.
The hob main shaft is automatically moved in the axial direction so that the hob and the workpiece are opposed to each other, the phase of the hob blade and the roughed work tooth groove are adjusted, and the mounting angle of the hob main shaft to the work is adjusted. Make changes automatically.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 show a hobbing machine, which comprises a bed 1 installed on a floor and a column 2 fixed to one side of the bed 1.
And a hob saddle 3 provided on the column 2 so as to be vertically movable.
A hob head 4 provided on the hob saddle 3 so as to be rotatable about a horizontal axis, a slide table 5 provided on the bed 1 so as to be movable in a horizontal direction, and a vertical axis provided on the slide table 5 It is mainly composed of a rotary table 6 rotatable around, a support 7 fixed to the slide table 5, and a support arm 8 provided on the support 7 so as to be vertically movable.

The hob head 4 has a hob main shaft 9 having an axis perpendicular to the horizontal axis and driven to rotate.
The hob main shaft 9 is movable in the axial direction by a hob shift device 10. The hob arbor 11 is attached to the hob main shaft 9.
The single cutter 12 and the hob 13 are mounted on the hob arbor 11 on the same axis.

A lower end of a work 14 is attached to the rotary table 6, and an upper end of the work 14 is supported by the support arm 8, and the work 14 is driven to rotate about a vertical axis by the rotary table 6. The hobbing machine is NC (numerical control), and the movement of each part is performed fully automatically.

FIG. 3 shows the single cutter 12 and FIG.
Indicates the hob 13. A processing method using the hobbing machine will be described with reference to FIG. First, the single cutter 12 and the hob 13 are attached to the same arbor 11 in series, and the arbor 11 is attached to the hob main shaft 9. Then, the lower end of the work 14 is attached to the rotary table 6, and the upper end is supported by the support arm 8. Then press the start button,
The hobbing machine starts processing automatically.

That is, first, roughing is started. In this roughing, the rotation angle of the hob head 4 is set so that the hob main shaft 9 intersects the axis of the work 14 at a predetermined angle, and the hob shift device 10 is set so that the single cutter 12 faces the work 14. Is controlled, and the slide table 5 is driven to move the work 14 and the single cutter 1.
2 and the rotary table 6 is driven, and the saddle 3 is also driven, so that the work 14 is subjected to screw cutting of the screw portion. When the machining of one groove of the screw portion is completed, the rotary table 6 performs indexing to machine the next groove, and the rough machining of the groove is performed in the same manner as described above. The cutting speed of this roughing is about 150m
/ Min.

When the roughing of all the grooves is completed, the process proceeds to finishing. At the time of this finishing, the work 1 of the hob spindle 9
4 is changed. Then, the hob shift device 10 is controlled such that the hob 13 faces the work 14. Next, the rotation speed of the hob spindle 9 and the rotary table 6
, The feed speed of the saddle 3 and the like are all fully automatically controlled, and the finishing of the screw portion is performed. The cutting speed at this time is about 50 to 60 m / min.

Since a series of these operations are performed for processing, it is not necessary to change the work between the conventional rough processing and the finishing processing. That is, the one-chuck processing in which the setting (centering and phase alignment) of the work was omitted was performed.
According to the above method, the processing time was reduced by about 31% as compared with the conventional method in which roughing and finishing were performed by a hob.

The present invention is not limited to the above embodiment.

[0019]

According to the present invention, high-precision machining can be performed when machining the screw portion of the screw rotor.
The processing time can be reduced. Conventionally, 2
What is processed by one machine is processed by one machine, so that the transportation cost and floor space can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an outline of a hobbing machine.

FIG. 2 is a perspective view showing a main part of the hobbing machine.

FIG. 3 is a plan view and a front view showing a single cutter.

FIG. 4 is a perspective view showing a hob.

FIG. 5 is an explanatory diagram of a processing method.

[Explanation of symbols]

 12 Single cutter 13 Hob

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tatsuo Goishi 41 Harima-cho Niijima, Kako-gun, Hyogo Prefecture Inside the Harima general-purpose compressor plant at Kobe Steel Co., Ltd. Kobe Steel, Ltd.Harima general-purpose compressor factory (72) Inventor Megumi Konishi 41, Niijima, Harima-cho, Kako-gun, Hyogo Prefecture Kobe Steel, Ltd.Harima general-purpose compressor factory (72) Inventor Shoji Yoshimura Takasago, Hyogo Prefecture 2-3-1, Shinhama, Araimachi Kobe Steel, Ltd. Takasago Works

Claims (2)

[Claims] In a method of processing a screw portion of a screw rotor using a single cutter and a hob by a hob machine, a single cutter and a hob are arranged on the same axis on a hob main shaft, and roughing is performed by a single cutter. And a finishing process by a hob. 2. The transition from roughing to finishing is performed by automatically moving the hob main shaft in the axial direction so that the hob and the work are opposed to each other, while the single cutter and the work are opposed to each other. 2. The method for processing a screw portion of a screw rotor according to claim 1, wherein the mounting angle of the hob spindle to the workpiece is automatically changed.