JPS58186530A - Machining method of herringbone groove in journal shaft - Google Patents

Abstract

PURPOSE:To form a groove to a uniform depth further obtain a flat bottom of the groove, by intermittently rotating a journal shaft in machining fluid while successively electric discharge machining the herringbone groove with a salient electrode. CONSTITUTION:Machining fluid 38 is filled in a machining tank 31. A journal shaft 33 is intermittently rotated by a rotation controller 40 supported in the machining fluid. A machining electrode body 35 having salient electrodes 36 corresponding to plural herringbone grooves to be machined is arranged at a face-to-face position to the journal shaft 33 in the machining fluid, and the herringbone grooves are successively formed to the journal shaft by electric discharge action when intermittent rotation is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a method for machining a herringbone groove in a journal shaft, and in particular to a method for machining fI4J of a laser beam in a laser printer.
J3I! This invention relates to an improvement in the method of machining a herringbone groove in a journal shaft of a rotating mirror used for scanning.

(Middle) Prior art and problems Electrophotographic transfer printers that use laser beam scanning (hereinafter referred to as laser printers) generally have the following characteristics, as shown in Figure 1:
A charging means 2 charges a stain on a photosensitive drum 1 attached to a rotating means, and a laser beam from a laser oscillator 8 is applied to the photosensitive surface of the drum 1 in a dot pattern of characters by an A-○ modulator 4. - The light is turned off, and the light is scanned linearly at high speed in the axial direction of the photosensitive dome 1 by the rotating mirror 5 to sequentially expose it. The character latent image on the drum l formed on the conductive pongee by the exposure is developed by the magnetic shoes V developed i1
6, and toner, which is a recording medium, is deposited on the latent image. This toner image is transferred onto the E3 peak paper 9 fed out from the hopper 8 in the transfer section 7.
The upper transferred toner image is sent to the fixing section 10 and fused to the paper 9 by heat and pressure, thereby recording the character pattern.

By the way, in a laser printer configured as described above, especially a high-speed or ultra-high-speed laser printer that prints one line or more per minute, when the rotation -5 is rotated at high speed in order to scan the laser beam at high speed, The air bearing eliminates inconveniences caused by friction between the rotating mirror 5 and the journal shaft that rotatably supports it. That is, conventionally, this air bearing is 4-j as shown in FIG.
A large number of herringbone grooves 2b are carved on the outer circumferential surface of a journal shaft 24, which has a rotor 21 and a mirror surface 22 around it and rotatably supports a nine-cylindrical rotating mirror.
5 is rotated by the motor rotor 828 combined with the motor rotor 21, sewing rotation! 15 and Sufusto bearing stand! Air is drawn into the gap with the journal shaft 24 and the herringbone groove 25 from between the rotary mirror 5 and the journal shaft 24, and the rotating mirror 5 floats above the Sufst bearing stand 26 and is in non-contact with the journal shaft 24 through the air. A 1i structure that rotates at

However, in the past, in order to carve a large number of herringbone grooves 25 on the outer peripheral surface 11 of the journal shaft 24,
Rounding, which uses photo-etching technology, requires large-scale equipment and special processing techniques;
Such processing operations become extremely complicated and processing costs increase. See you again! There is a problem in that the machining accuracy for the depth of the herringbone groove 25 is difficult, and the bottom of the groove is difficult to finish flat.
Due to the uneven finish of the groove depth, the rotational axis of the rotating mirror 6 shifts, which is extremely undesirable for high-speed rotation.

(0) Purpose of the Invention In view of the shortcomings of the 1st century conventional technology, the present invention provides a novel method that enables the machining of a large number of herringbone grooves on the outer circumferential surface of a journal shaft easily and with high precision using electrical discharge machining technology at high efficiency and low cost. The purpose is to provide a processing method.

1) Structure and object of the invention According to the present invention, a journal shaft having a plurality of herringbone grooves carved on its outer circumferential surface is intermittently rotated at a predetermined angle in a machining tank in which machining fluid is stored. The pole bodies are disposed opposite each other and are rotated intermittently. At each rotation stop of the journal shaft! tI period machining'ii [Due to the electric discharge action of the pole body,
This is achieved by providing a method for machining a herringbone groove in a journal shaft, which is characterized in that several hemlocks are formed on the outer circumferential surface of the journal shaft.

(θ) *Polar side of the invention Preferred embodiments of the invention will be described in detail below using the drawings.

FIG. 8 is a #'rthi diagram conceptually showing an embodiment of an electric discharge machining apparatus used in the method of machining a herringbone groove of a journal shaft according to the present invention.

In the figure, 81 is a processing tank, and a rotation mechanism 82 that is arranged in 1181 and can rotate intermittently at a predetermined angle during processing.
For example, a journal shaft 88 made of a material called Ferrotic C, which is an alloy of iron (Fe) and titanium (T1), is carved with a herringbone groove of the number 1 on the outer circumferential surface, as shown in the figure. A machining electrode body having a protrusion of 11 & 11 corresponding to a plurality of herringbone grooves 84 to be carved along the outer circumferential predetermined area #JK on the yarn shaft 8B with a pole 86. Feed 8b! 11188, and are arranged facing each other with a predetermined gap. In this embodiment, the structure of the machining pole body 85 is as shown in FIG. As shown in the figure, four protruding electrodes 86 made of, for example, a silver (Ag)-tungsten (W) alloy with low electrical resistance, corresponding to a herringbone $84, are provided on the curved surface.

As shown in the figure, a machining fluid 88 made of, for example, kerosene or transformer oil is stored in the machining tank 81 having such a structure, and the machining electrode body 85 connected to the feed@@B'l is discharged [m
tm89 as an anode, and the journal shaft 88 as a cathode! [In a good continuous state, a discharge is generated between the journal shaft 88 and each protruding electric current FM8B of the machining electrode body 86 facing the other, and the feed m-B7 is interlocked, so that a predetermined depth is reached by the discharge action. After that, the journal shaft 88 is intermittently rotated by 10 degrees at a time in the direction of the arrow by the control device 40 that controls the journal shaft 88 by 8 rotations, and the above-mentioned discharge is performed. By repeating the machining operation, a large number of herring pawns #84 are carved on the outer !#4 surface of the journal shaft 88. In this way, a large number of precision holes with a predetermined depth and a flat groove bottom are carved. Journal shaft 88 with ring pawn #184 on the outer circumference
It is possible to easily and efficiently obtain 1N capacity.

(G) Effects of the Invention As is clear from the above explanation, the present invention allows a large number of herringbone grooves to be carved very efficiently, and also that #I is flattened and highly accurate herringbone grooves can be easily formed. It is extremely advantageous for machining herringbone grooves on journal shafts of rotating mirrors. Furthermore, by applying the journal shaft obtained by this machining force method to support the rotating mirror of a laser printer, it is possible to improve the reliability of the laser printer.

[Brief explanation of the drawing]

Fig. 1 is a conceptual diagram explaining a laser printer, Fig. 2 is a cross-sectional view of a main part explaining a journal shaft that supports a rotating mirror in a laser printer, and the conventional herringbone groove machining method, and Fig. 8 is a sectional view of the present invention. Electric discharge machining 4I used for machining method of herringbone groove of journal shaft related to! ! t! which conceptually shows one embodiment of the system. FIG. 4 is a perspective view showing the processing electrode body in FIG. In the figure, 81 is a processing tank, 82 is a rotation mechanism, 8B is a journal shaft, 84 is a plurality of herringbone grooves 85 is a processing 1
86 is the protruding electrode, 87 is the feeding machine, 188 is the machining fluid, 8g is the discharge power source, and 40 is the rotation control device. , Figure 1, Figure 21.4

Claims (1)

[Claims] A method of carving K11ilk herringbone grooves on the outer circumferential surface of a journal shaft, the shaft being provided so as to be able to rotate intermittently by a predetermined angle in a machining tank in which machining fluid is stored; Machining electrode bodies having protruding IT poles corresponding to a plurality of herringbone grooves to be carved are disposed facing each other along a predetermined outer circumference surface of the journal shaft, and in each stop state of the journal shaft that rotates intermittently. A method for machining herringbone grooves in a journal shaft, characterized in that a plurality of herringbone grooves are sequentially formed on the outer peripheral surface of the journal shaft by the electric discharge action of a machining electrode body.