JP2007253290A - Apparatus and method for blasting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely prevent a blasted sleeve having poor roundness and poor rotation accuracy from being fed to the next process by exactly recognizing the irregular rotation and the rotation locking of the sleeve in a blasting process. <P>SOLUTION: The sleeve 2 is held by a driving-side holding jig 21 and a driven-side holding jig 22. The blasting treatment is carried out by jetting particles (blasting media 12) on the surface of the sleeve 2 from a blasting nozzle 11 moving upward and downward in the axial direction of the sleeve 2 while rotating the sleeve 2. In this case, the blasting treatment is carried out while measuring the rotation of the driven-side holding jig 22. When the driven-side holding jig 22 abnormally rotates, the blasting treatment is stopped based on the information about the rotation. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a blasting apparatus and a blasting method for performing a blasting process (roughening) on a sleeve of a developing roll mounted on a copying machine, a laser printer, or the like, and in particular, for realizing a uniform roughening. Related to technology.

  A developing roll for visualizing an electrostatic latent image formed on a photosensitive drum such as a copying machine or a printer has a cylindrical shape made of metal made of aluminum, stainless steel, or the like, with a magnet piece attached to the peripheral surface of a shaft, for example. It is configured by attaching a sleeve. In developing, the developer (toner) is transported to the surface of the photosensitive drum by the sleeve and fixed on paper or the like, so that characters or images corresponding to the electrostatic latent image are visualized (printed).

  The metal sleeve used as described above has a roughened surface so that the developer can be efficiently conveyed. In this case, various methods are known for roughening the sleeve surface, but it is general to use a blasting method in which particles are jetted onto the sleeve surface to roughen the surface.

  In this case, the blast medium (particles) is irradiated while rotating around the central axis of the sleeve. However, as the requirements for roundness and runout accuracy become stricter, uniform blasting has been required. Therefore, various techniques for realizing uniform blasting have been proposed (see, for example, Patent Document 1 to Patent Document 3).

  For example, Patent Document 1 discloses a surface roughness process in which a workpiece (sleeve) is rotated, and abrasive grains (blast media) are ejected onto the surface of the workpiece to give a predetermined surface roughness to the surface of the workpiece. In the method, there is disclosed a surface roughness treatment method in which the discharge direction of abrasive grains to the surface of a workpiece is made uniform around the workpiece and the workpieces are opposed to each other. In the invention described in Patent Document 1, two blast nozzles are arranged so as to be movable substantially parallel to the axis of the sleeve.

  The invention described in Patent Document 2 relates to the regeneration of the developer carrier (sleeve), but when performing the blasting, the nozzle is rotated in the axial direction of the sleeve by rotating at a constant speed around the center of the sleeve circle. It is disclosed that particles are ejected while being discharged. In the invention described in Patent Document 2, the sleeve is supported so as to be rotated by a rotary motor, and a masking jig is attached to the surface. The masking jig is a jig that covers the non-blasted portion at the end of the sleeve.

Patent Document 3 discloses a configuration in which a rotation position (rotation angle) index detection sensor of a rotation drive shaft is attached and the rotation speed is controlled according to the rotation position. Specifically, a rotating plate with a plurality of docks is provided concentrically on the rotating shaft that rotates the workpiece (metal casting product), and the number of docks is counted by the position index detection sensor. And controlling the rotational speed. That is, it is disclosed that the rotation speed is switched during one rotation.
JP-A-8-90416 JP 2003-20809 A JP 2000-263446 A

  By the way, when the requirements for roundness and runout accuracy of the sleeve become strict, it is necessary to prevent shaft blurring when rotating the sleeve, and the rotation shaft for rotating the sleeve also supports the gap ( The gap) must be set narrower. In this case, it is necessary to pay attention to the occurrence of rotation unevenness due to the entry of particles into the gap.

  When performing the blasting process, the sleeve is held by the driving side holding jig and the driven side holding jig, and the surface of the sleeve is irradiated with the blast medium while rotating around the sleeve axis. At this time, as described above, the gap that supports the rotating shaft becomes narrower. For example, when the blasting medium rises in the blasting apparatus, the blasting medium enters the gap, and a phenomenon called so-called powder galling occurs. appear. When this dusting is generated, the rotation is braked and the sleeve cannot be rotated at a constant speed, and this causes idle rotation at the clamp portion (holding member) of the driven holding jig. In addition, the rotation axis is shifted. When such rotation unevenness or rotation stop is caused, blasting is not performed uniformly, and a problem that roundness and runout accuracy become poor occurs.

  In the above-described conventional technology, it is not possible to cope with the problems caused by the dusting as described above, and countermeasures are desired. For example, in the invention described in Patent Document 3, a configuration for controlling the rotation speed is disclosed. However, no consideration is given to the holding structure of the product to be processed (metal casting product), in particular, the driven side, and the rotation drive is not considered. The purpose is to control the rotation speed according to the rotation angle of the shaft, and no consideration is given to how to deal with rotation unevenness or rotation stoppage.

  The present invention has been proposed in view of such conventional circumstances, and can accurately grasp the rotation unevenness and rotation lock of the sleeve during the blasting process. For example, the roundness and runout accuracy are poor. It is an object of the present invention to provide a blast processing apparatus and a blast processing method capable of reliably preventing the occurrence of blast inferior goods.

  In order to achieve the above-mentioned object, the blasting apparatus of the present invention includes a driving side holding jig and a driven side holding jig that respectively hold both ends of the sleeve, and moves up and down in the central axis direction of the sleeve. A blast nozzle having a blast nozzle for injecting particles onto the surface and performing a blasting process by injecting particles onto the sleeve surface with the blast nozzle while rotating the sleeve with the driving side holding jig and the driven side holding jig. In the processing apparatus, the driven side holding jig is a state in which a rotation shaft of the driven side holding jig is supported by a fixed base via a bearing and detects a rotation speed of the rotary shaft. A detection mechanism is provided.

  In the blasting method of the present invention, the sleeve is held by the driving side holding jig and the driven side holding jig, and particles are applied to the sleeve surface by the blast nozzle that moves up and down in the central axis direction of the sleeve while rotating the sleeve. Is a blasting method in which the blasting process is performed by detecting the rotation of the driven side holding jig.

  In the present invention, as described above, the rotation detection mechanism detects rotation unevenness or rotation lock of the driven side holding jig, and stops rotation of the driving side holding jig based on the detected rotation speed information, for example. The main purpose is to take measures. If rotation unevenness or rotation lock is detected in the driven side holding jig, it is considered that rotation unevenness or rotation lock has also occurred in the sleeve due to the influence of dusting. Therefore, when the rotation unevenness or the rotation lock of the driven side holding jig is detected, the sleeve with poor roundness and runout accuracy does not flow out by removing the poor blast product by stopping the rotation.

  According to the present invention, it is possible to accurately grasp the rotation unevenness and rotation lock of the sleeve during the blasting process. For example, it is ensured that a bad blast product with poor roundness and runout accuracy is misused in the next process. It is possible to prevent.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a blast processing apparatus and a blast processing method to which the present invention is applied will be described in detail with reference to the drawings.

  First, the structure of a developing roll in which a sleeve to be blasted is incorporated will be described. As an example, as shown in FIG. 1, the developing roll 1 includes a cylindrical sleeve 2 and a magnet and a shaft. It is configured by incorporating a solid (hereinafter referred to as a magnet shaft) 3. The sleeve 2 is made of a nonmagnetic material, and is made of a metal material such as aluminum or stainless steel. Further, it is formed as a cylindrical body having a length sufficient to accommodate the magnet shaft 3. Specific examples of dimensions of the sleeve 2 are an outer diameter of 20 mm, an inner diameter of 18.8 mm (thickness of 0.6 mm), and a length of 230 mm to 320 mm. Further, a gap having a predetermined interval is formed between the inner peripheral surface of the sleeve 2 and the outer peripheral surface of the magnet shaft 3 accommodated therein.

  The magnet shaft 3 is configured, for example, by arranging a plurality of magnet shaft magnets 5 around a metal shaft 4 and fixing them. Each of the magnet shaft magnets 5 has a fan-shaped cross section, and these are bonded to the periphery of the shaft 4 to constitute a magnet body having a generally cylindrical shape as a whole.

  Each magnet shaft magnet 5 is often formed by extrusion molding or injection molding a mixture containing a binder (thermoplastic resin) and magnet powder. Here, the type of the binder is not particularly limited, and specifically, polyamide resins (nylon 6, nylon 12, etc.), polyolefin resins such as polypropylene and polyethylene, polycarbonate resins, and the like can be used. Examples of the magnet powder include ferrite magnet powder (for example, Sr-based ferrite powder and Ba-based ferrite powder) and rare earth metal magnet powder (for example, SmCo-based, NdFeB-based, SmFeN-based, etc.). What is necessary is just to select according to the characteristic requested | required from these.

  The magnet shaft magnets 5 are each magnetized in a substantially radial direction, and the outer peripheral surface side is set to N pole or S pole, and the N pole and S pole are alternately arranged on the outer peripheral surface of the magnet shaft 3. Are combined. These magnet shaft magnets 5 function as a pumping pole, a layer regulating pole, a transport pole, a developing pole, and a peeling pole, and are attached in a predetermined arrangement in the rotation direction of the sleeve 2.

  The shaft 4 is made of a high-strength material such as metal and is longer than the length of the magnet shaft magnet 5 attached to the peripheral surface, and therefore when the magnet shaft magnet 5 is attached to the peripheral surface. , Both ends are exposed. Both end portions of the exposed shaft 4 are rotatably inserted into flanges 6 and 7 provided at both ends of the sleeve 2 through bearings 8 and 9. One end side of the shaft 4 is inserted through the flange 6 and extends outward. The other end is abutted against the flange 7, and a shaft portion 7 a is provided on the flange 7 so as to extend the shaft 4. ing.

  Here, when the shaft portion 7 a is rotationally driven from the right flange 7 side in FIG. 1, the rotation is transmitted to the sleeve 2 via the flange 7. Therefore, the right flange 7 is called a drive side flange, and is formed of a nonmagnetic material (for example, aluminum or stainless steel) having excellent wear resistance. On the other hand, the left flange 6 in FIG. 1 has only a function of holding the magnet shaft 3 in the sleeve 2 and is called a driven flange, and is made of the same material as the flange 7 (drive flange). Although formed, it may be formed of a lightweight and low-cost resin material or the like.

  When assembling the developing roll having the above-described configuration, the magnet shaft 3 is inserted into the sleeve 2 and the flanges 6 and 7 are press-fitted into the sleeve 2 for assembly. Thereafter, the surface of the sleeve 2 is subjected to a blasting process for roughening. Of course, the sleeve 2 alone may be subjected to blasting for roughening. Hereinafter, a blast processing apparatus and a blast processing method used for this blast processing will be described.

  FIG. 2 shows an example of a blasting apparatus for performing the blasting process. The blasting apparatus of this example is a so-called parallel movement type blasting apparatus, and the blast nozzle 11 moves in the vertical direction (in the direction of the arrow in the drawing) so as to be parallel to the rotation axis of the sleeve 2. The moving speed is, for example, about 2 to 30 mm / second. The distance between the blast nozzle 11 and the sleeve 2 is about 50 to 150 mm. Although the shape of the blast nozzle 11 is various, for example, a cylindrical one having a diameter of 5 to 10 mm may be used.

  In the case of this example, the blast nozzles 11 are arranged opposite to each other with the sleeves 2 interposed therebetween, and each blast nozzle 11 is supplied with blast media such as compressed air and abrasive grains, and the blast media is supplied to the sleeves 2 with compressed air. Inject towards. The blast media may be spherical powder or alundum powder, and examples thereof include glass, metal, zircon, and ceramic. The injection pressure is about 0.2 to 0.5 MPa.

  In this blasting apparatus, the blasting medium (particles or powder) 12 is sprayed while moving the blast nozzle 11 up and down, and the surface is roughened by applying it to the surface of the cylindrical sleeve 2. The blasting process for roughening is performed while rotating the sleeve 2 so that the entire circumference of the sleeve 2 is uniformly roughened. The rotation speed is about 10 to 300 rotations / minute, and is set together with the above-described movement speed of the blast nozzle 11 and other conditions.

  Note that the blast processing apparatus is not limited to the parallel movement type blast processing apparatus, and for example, an oscillating blast processing apparatus may be used. This swing type blast processing apparatus ejects a blast medium 12 from a blast nozzle 11 attached to the tip while swinging a swing arm in an arc shape.

  FIG. 3 shows a rotation mechanism for rotating the sleeve 2. As shown in FIG. 3, the rotating mechanism includes a driving side holding jig 21 and a driven side holding jig 22 that hold both ends of the sleeve 2 of the developing roll 1 and mask each end. The sleeve 2 is rotationally driven in a state held by. Here, urethane holding members 21 a and 22 a are respectively attached to the driving side holding jig 21 and the driven side holding jig 22, and the inner diameters of these holding members 21 a and 22 a are the outer diameters of the sleeve 2. Is set to be slightly smaller. Therefore, by inserting both end portions of the sleeve 2 into the holding members 21a and 22a, the sleeve 2 is held by the driving side holding jig 21 and the driven side holding jig 22 and is driven by the frictional force of the holding members 21a and 22a. As the holding jig 21 rotates, the sleeve 2 and the driven side holding jig 22 are also rotated.

  Further, the driving side holding jig 21 and the driven side holding jig 22 have rotating shafts 21b and 22b, respectively, and a motor 23 is attached to the rotating shaft 21b of the driving side holding jig 21, thereby rotating. The structure is driven.

  Here, the rotating shaft 21b of the driving side holding jig 21 is inserted into a through hole 25a provided in the first fixing base 25 via a bearing 24 formed of polyacetal resin (trade name Duracon) or the like. The first fixed base 25 is connected to the motor 23 on the back side.

  On the other hand, the driven holding jig 22 is connected to a through hole 26a provided in a second fixing base 26 assembled in the apparatus with a predetermined distance from the first fixing base 25 via a bearing 27. And is movable in the vertical direction and is in a rotation-free state. Therefore, when the sleeve 2 is mounted, the driven side holding jig 22 is raised and the lower end portion of the sleeve 2 is inserted into the driving side holding jig 21, and then the driven side holding jig 22 is lowered to move the upper end of the sleeve 2. Insert the part into this.

  Blasting is performed while rotating the sleeve 2 by the rotation mechanism having the above structure, but the bearings 24 and 27 of the rotary shafts 21b and 22b are formed of a resin material such as polyacetal because of a demand for low friction. . Further, from the viewpoint of preventing shaft shake, the gap between the bearings 24 and 27 and the rotary shafts 21b and 22b is set to 500 μm or less (for example, about 100 μm). When the blasting process is performed in such a situation, blasting media (powder) or fine powder obtained by pulverizing the powder may soar (or fall) around the rotating mechanism. Blasting media or fine powder may enter the gaps between the bearings 24 and 27 and the rotary shafts 21b and 22b, and so-called dusting may occur.

  For example, with respect to the driving side holding jig 21, the dusting plate is provided with a large-diameter umbrella-type dustproof plate 28 and rotates integrally with the driving side holding jig 21. By covering up the through-hole 25a provided in the fixed base 25, it is possible to prevent the blasting media or the fine powder that soars (or falls) from entering the gap. On the other hand, since the driven side holding jig 22 needs to be moved up and down when the sleeve 2 is mounted, it is not possible to install a dustproof plate between the driven side holding jig 22 and the fixed base 26. difficult.

  Therefore, in the present embodiment, sealing members 29 and 30 formed of felt or the like are installed so as to close both open ends of the through holes 26a of the fixing base 26 into which the driven side holding jig 22 is inserted. In addition, a rotation detection mechanism that detects the rotation state of the rotation shaft 22b of the driven side holding jig 22 is provided.

  The rotation detection mechanism may be any mechanism that can detect the rotation of the driven side holding jig 22. In the present embodiment, the rotation detecting mechanism is provided at the tip of the rotating shaft 22 b of the driven side holding jig 22. A rotation detection member 31 that is in the form of a gear having detection teeth formed at intervals is attached, and a rotation sensor 32 that detects the rotation of the rotation detection member 31 is attached to the fixed base 26.

  FIGS. 4A and 4B show how the rotation detection member 31 and the rotation sensor 32 are attached. The rotation detection member 31 has a plurality of (here, four) detection teeth 31a at equiangular intervals (here, 90 ° intervals), and rotates with the rotation of the rotation shaft 22b. When rotating at a constant rotational speed, the detection teeth 31a face the rotation sensor 32 at regular time intervals.

  The rotation sensor 32 only needs to be able to detect the rotation speed (cycle) of the detection tooth 31a. For example, if each detection tooth 31a is formed of a magnetic material and a Hall element or the like is used as the rotation sensor 32, the rotation sensor 32 Whether or not the detection teeth 31a are opposed to each other can be extracted as a magnetic signal. Alternatively, the detection tooth 31a may be formed of a material having a high light reflectance, light may be emitted from the rotation sensor 32, and the return light reflected by the detection tooth 31a may be detected. In any case, the signal detected by the rotation sensor 32 has a pulse waveform having a constant pulse interval t as shown in FIG.

  As described above, the sealing member 29, 30 made of felt or the like is installed in the vicinity of the opening of the through hole 26a of the fixed base 26 with respect to the driven side holding jig 22, thereby preventing powder from entering the bearing 27. can do. However, the powder that could not stop intrusion by the sealing members 29 and 30 enters the gap between the bearing 27 and the rotating shaft 22b, and causes powdering. If dusting occurs and rotation unevenness or rotation lock of the driven side holding jig 22 is caused, there is a problem in uniformly roughening the surface of the sleeve 2 and there is a possibility that it becomes a blast poor product.

  In the present embodiment, in the unlikely event that the dusting occurs and rotation unevenness or rotation lock occurs in the driven side holding jig 22, this is detected by the rotation detection mechanism, and the motor of the driving side holding jig 21 is immediately detected. The drive by 23 is stopped and the blasting process is stopped.

  When the driven side holding jig 22 rotates at a constant rotation speed (steady rotation), the signal detected by the rotation sensor 32 has a constant pulse interval t as shown in FIG. It has a pulse waveform. On the other hand, for example, when a rotational load is applied due to dusting and uneven rotation occurs, the driven side holding jig 22 slips. As a result, as shown in FIG. 5B, a part of the pulse signal interval widens, and a signal having a pulse interval T larger than the pulse interval t is detected. Alternatively, when the rotational speed of the driven side holding jig 22 gradually decreases due to dusting, the pulse interval between the pulse signals gradually increases as shown in FIG. 5 (c), such as t1 <t2 <t3. Become.

  Therefore, if the pulse signal shown in FIG. 5 (b) or the gradual increase of the pulse interval shown in FIG. 5 (c) is detected by the rotation sensor 32 and this is fed back as rotation speed information, the occurrence of blasting bad products can be prevented. I can grasp it. For example, if the control circuit for stopping the rotation according to the rotation speed information is incorporated in the control circuit of the motor 23 that rotationally drives the drive side holding jig 21, the rotation sensor 32 detects the rotation unevenness and the rotation lock. In this case, the rotation of the sleeve 2 can be stopped by stopping the motor 23, and wasteful processing can be suppressed. In addition, it is possible to identify a blast rough product in which unevenness or the like has occurred in the surface roughening due to abnormal rotation, and to prevent outflow to a subsequent process.

  As described above, according to the blast processing device and the blast processing method of the present invention, when rotation abnormality such as rotation unevenness or rotation lock occurs in the driven side holding jig 22, this is detected by the rotation sensor 32. Feedback and take measures such as stopping rotation. Therefore, it is possible to accurately grasp the blast poor product, for example, it is possible to reliably prevent the blast poor product with poor roundness and runout accuracy from being misused in the next process.

  Hereinafter, specific experimental examples to which the present invention is applied will be described.

  In this experimental example, the sleeve 2 was blasted using the sleeve rotation mechanism shown in FIG. 3, but at this time, the gear 31 (four detection teeth 31a) was attached to the driven side holding jig 22. At the same time, the rotation sensor 32 was attached to the fixed base 26. In addition, it experimented in the state which removed the felt as the sealing members 29 and 30 in order to confirm the function of a rotation detection mechanism.

  The blasting conditions were set as follows. The blast nozzle 11 is disposed so as to face the sleeve 2, and the blast nozzle 11 is moved in the vertical direction so as to be parallel to the rotation axis of the sleeve 2. The moving speed was 14 mm / second. The distance between each blast nozzle 11 and the sleeve 2 was 125 mm. Each blast nozzle 11 was cylindrical and had a diameter of 7 mm. As the blasting media, powder (trade name: Fuji Zircon Beads FZB-120) having an average particle size of 110 μm (particle size of about 63 to 125 μm) was used, and the injection pressure was set to 0.4 MPa. The rotational speed of the sleeve 2 was 120 revolutions / minute.

  As a result, when a blasting process was started, a pulse waveform having a constant pulse interval was obtained. However, it was found that the pulse interval due to dusting gradually increases when the blasting process is continued for about 8 hours. When the blasting process was further continued for 5 hours, a part of the pulse signal interval widened, and the blasting process was stopped when the pulse interval became longer than the set pulse interval (for example, +0.06 seconds). As a result, it was possible to prevent the outflow of defective blasting material (sleeve) due to dusting.

It is a schematic sectional drawing of a developing roll. It is a figure which shows an example of a blasting apparatus typically. It is a figure which shows the rotation mechanism of a sleeve. An example of a rotation detection mechanism is shown, (a) is a schematic plan view, (b) is a schematic side view. An example of a detection signal detected by the rotation detection mechanism is shown. (A) is an example of a pulse signal waveform during normal rotation, (b) is an example of a pulse signal waveform when rotation unevenness occurs due to slip, (c ) Shows an example of a pulse signal waveform when the rotational speed is gradually decreasing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Developing roll, 2 Sleeve, 3 Magnet shaft, 4 Shaft, 5 Magnet shaft magnet, 6, 7 Flange, 11 Blast nozzle, 12 Blast media, 21 Drive side holding jig, 22 Drive side holding jig, 21a, 22a Holding member, 21b, 22b Rotating shaft, 23 Motor, 24 Bearing, 25 First fixing base, 25a Through hole, 26 Second fixing base, 26a Through hole, 27 Bearing, 28 Dustproof plate, 29, 30 Sealing member 31 rotation detection member, 31a detection tooth, 32 rotation sensor

Claims (8)

A drive-side holding jig and a driven-side holding jig that hold both ends of the sleeve, respectively, and a blast nozzle that moves up and down in the central axis direction of the sleeve and injects particles onto the sleeve surface. A blasting apparatus for performing blasting by injecting particles onto the surface of the sleeve by the blast nozzle while rotating the sleeve by a jig and a driven side holding jig,
The driven side holding jig is in a state in which the rotating shaft of the driven side holding jig is supported by a fixed base via a bearing, and is provided with a rotation detection mechanism for detecting the rotation speed of the rotating shaft. A blasting apparatus characterized by comprising:   The blast processing apparatus according to claim 1, wherein the rotation detection mechanism includes a rotation detection member attached to the rotation shaft and a rotation sensor attached to the fixed base.   The rotation detection member attached to the rotation shaft has a gear shape in which detection teeth are formed at predetermined intervals, and the rotation sensor detects a rotation state of the rotation shaft based on a signal based on the detection teeth. The blasting apparatus according to claim 2.   4. A blasting process according to claim 2, further comprising a control mechanism for stopping the blasting process based on rotational speed information detected by the rotation sensor when a rotation abnormality occurs in the driven side holding jig. apparatus.   The blast processing apparatus according to claim 1, wherein the bearing is installed on an inner wall surface of a through hole formed in the fixed base.   6. The blasting apparatus according to claim 5, wherein the bearing is a bearing made of polyacetal resin, and a gap between the driven holding jig and the rotating shaft is set to 500 μm or less. A blasting method in which a sleeve is held by a driving side holding jig and a driven side holding jig, and particles are ejected onto the sleeve surface by a blast nozzle that moves up and down in the central axis direction of the sleeve while rotating them. Because
A blasting method, wherein the blasting process is performed while detecting the rotation of the driven side holding jig. The blasting method according to claim 7, wherein when a rotation abnormality occurs in the driven side holding jig, the blasting process is stopped based on rotation speed information of the driven side holding jig.

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