JP3591255B2 - Magnet roll warpage correction method - Google Patents

Description

【００１８】
図５では、比較品１及び本発明品１〜５までのデータをａの実線で示し、１０本〜４０本までの間の本数が反りの矯正効果が大きく、４０本を超えると、矯正効果が低下することがわかる。そして、図中ｂは、所定本数に束ねた後、８０〜１５０°Ｃの環境下で３〜１０時間熱処理を行い１０時間をかけて除冷したマグネットロール１を測定した結果を示し、本数が多くなればなるほど反り量が減っていることがわかる。
図６によれば、反り量が大きいほどゾーン値も大きくなっていることがわかる。
又、図７に、加熱温度と反り量を示すグラフが示され、加熱温度が高く、しかも加熱時間が多いほど反り量が小さいことがわかるが、図８に示すように、加熱温度が１５０°Ｃ以上で且つ加熱時間が５時間以上になると、軸強度低下を引き起こし、加熱温度及び加熱時間を配慮する必要がある。
表１及び図５から明らかなように反り量平均が３００μｍ以下で、ゾーン値平均が４．０ｍＴ以下が好ましい。
【００１９】
又、前記実施例では、軸部とロール部とを一体形成するようにしたが、金属製または合成樹脂製のシャフトをインサートしたシャフトインサート型マグネットロールを形成したものにおいても本発明は適応することができる。
【００２０】
【発明の効果】
請求項１によれば、形成されたマグネットロールを長手方向に移動させて取り出す構成にすることによって、分割金型の場合のようなパーティングラインが存在しないから、形成されたマグネットロールにそれの長手方向にバリが発生することを無くすことができるとともに、真円度を高めることができ、完成度の高いマグネットロールを提供することができる。そして、このようにして形成されたマグネットロールに備えられている磁気吸引力を利用して複数のマグネットロールを束ねることにより、各マグネットロールの持つ磁力で相互に引き合う力を利用して、各マグネットロールに発生した反りを矯正することができるから、大掛かりな反り矯正用の機構等を設けることなく、反りの矯正が行え、コスト面において有利となる。
【００２１】
請求項２によれば、金型内での成形体表面温度が８０〜１５０°Ｃにまで冷却された時点でマグネットロールを取り出して、１０〜４０本を束ねた状態で冷却する場合が反り矯正に最適であることが測定結果からも明確である。
【００２２】
請求項３によれば、３０°Ｃ以下にまで除冷された成形品の反りを矯正する場合には、１０本以上束ねて８０〜１５０°Ｃに再度加熱してからその状態を３〜１０時間保持し、５時間以上かけて除冷すると更に高い矯正効果を得ることができ、一層精度の高いマグネットロールを得ることができる。
【００２３】
請求項４によれば、束ねた成形体をそれの長手方向が水平となる横置きにして反り矯正を行うことによって、縦置きにする場合の成形体の支持の難しさや軸部に重量が加わり軸部の振れにつながることを一挙に解消することができる。しかも、成形体を最も設置面積を多く取ることができる横置きにするから、自身の重量が成形体の長手方向に均一に作用して、安定した反りの矯正効果を得やすく、成形方法としては、最適である。
【図面の簡単な説明】
【図１】（イ）は溶融樹脂磁石の注入開始状態を示す金型の断面図、（ロ）は溶融樹脂磁石の注入完了状態を示す金型の断面図。
【図２】（イ）は端部成形型をメイン成形型に対して離間させた状態を示す金型の断面図、（ロ）は形成されたマグネットロールを離脱させた状態を示す金型の断面図。
【図３】（イ）は多数のマグネットロールをそれ自身の磁気吸引力により適当に束ねて置台上に載置した状態を示す正面図、（ロ）はその側面図。
【図４】（イ）はマグネットロールの両端を磁気吸引力により矯正しようとする説明図、（ロ）はマグネットロールの中央部を磁気吸引力により矯正しようとする説明図。
【図５】束の本数と反り量平均との関係を示すグラフ。
【図６】反り量平均とゾーン値平均との関係を示すグラフ。
【図７】加熱処理時間と反り量とを示すグラフ。
【図８】加熱温度と軸折れ強度とを示すグラフ。
【符号の説明】
１ マグネットロール ２ ロール本体部
３，４ 軸部 ５ メイン成形型
６ 端部成形型 ７ スライド型
８ 成形空間 ９ 磁場配向手段
１０ 注入口 １１ アクチュエータ
１２ 置台[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is for manufacturing a magnet roll used in an electrophotographic developing device such as a copying machine, a facsimile, and a printer, and a magnet roll used for other purposes, and then correcting a warpage of a formed magnet roll. The present invention relates to a method for straightening a magnet roll.
[0002]
[Prior art]
When manufacturing a magnet roll, generally, a resin magnet composition is injected into a split mold composed of a fixed mold and a movable mold that can be separated from the fixed mold, and the magnet roll is formed. An injection molding method is used.
However, in this method, in order to stabilize the magnetic properties in the longitudinal direction and reduce the warpage, the mold temperature is set to 110 to 130 ° C., and the inside of the mold is slowly cooled. Despite the fact that the cooling is performed over a long period of time in this way, a difference occurs in the amount of warpage of each molded body, stabilizing the longitudinal magnetic force (zone magnetic force) necessary for high image quality, The effect is not sufficient to reduce the warpage, and it is general to perform the warp correction in a later step.
[0003]
Immediately after the molded product is taken out (molded product surface temperature: 80 to 150 ° C.), there is also a method in which the molded product is sandwiched one by one with a two-part straightening mold and straightened, but a large-scale post-process (straightening process) is required. Although it is not necessary separately, the method of sandwiching one by one is troublesome and troublesome. Further, since the split mold has a parting line, burrs are generated through the parting line with the passage of time, and the size, shape, location, and the like of the burrs change for each molded product. There was a problem with the stability of the correction.
[0004]
[Problems to be solved by the invention]
In view of the above situation, the present invention is intended to solve the problem that the warpage can be easily corrected without requiring a large-scale post-process (correction process), and the warpage is stabilized by suppressing the occurrence of burrs. It is an object of the present invention to provide a method of straightening a magnet roll that can perform straightening.
[0005]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a resin magnet composition containing a magnetic powder and a binder as main components, which is injected and injected into a molding space formed by a mold, and a magnetic field provided in the mold. After applying a magnetic field of two or more poles by an orientation means, in a method of manufacturing a magnet roll that takes out from a mold, a main molding die for forming a roll body of the magnet roll is used as the mold, An end mold disposed at one end of the main mold to form one of the shafts formed at both ends, and an inner mold formed within the main mold to form the other shaft. A magnet roll is formed by using a slide die slidably disposed in the mold, and after this molding, the slide die is protruded into a molding space to take the magnet roll out of the die and take it out. Was plurality of magnet roll, bundled by adsorbing the magnetic attraction force of their own, is characterized by performing the correction of warpage by holding the bundled state.
Therefore, by forming the magnet roll formed to be moved in the longitudinal direction and taking it out, there is no parting line as in the case of the split mold, so that the formed magnet roll has burrs in the longitudinal direction thereof. Occurrence can be eliminated, and roundness can be increased. Then, a plurality of magnet rolls are bundled using the magnetic attraction provided in the magnet roll formed in this way. In this bundled state, the magnets are attracted to each other by the magnetic force of each magnet roll, so that a force for correcting the warp acts on each magnet roll.
[0006]
It is characterized in that the surface temperature of the formed body when the formed magnet roll is taken out of the mold is set to 80 to 150 ° C., and cooling is performed in a state where 10 to 40 pieces are bundled.
The minimum surface temperature of the molded body that can correct the warpage of the formed magnet roll by using the attraction force interacting with each other as described above is set at 80 ° C, and mechanical external force other than magnetic attraction force is applied. The maximum temperature of the surface of the compact which is solidified to such an extent that it cannot be deformed to 150 ° C. That is, when the surface temperature of the molded body in the mold is cooled to 80 to 150 ° C., the magnet roll is taken out and cooled in a state where 10 to 40 rolls are bundled. is there.
[0007]
It is characterized in that heat treatment is performed on the compacts bundled into 10 or more bundles in an environment of 80 to 150 ° C. for 3 to 10 hours, and the cooling is performed over 5 hours or more.
When correcting the warpage of the molded article which has been cooled down to 30 ° C or less, bundle 10 or more pieces, reheat to 80 to 150 ° C, hold the state for 3 to 10 hours, and hold for 5 hours or more If the cooling is carried out preferably for 10 hours or more, a higher correction effect can be obtained.
[0008]
By performing the warp correction by placing the bundled compacts horizontally so that their longitudinal direction is horizontal, it is difficult to support the compacts when placing them vertically, and the weight is added to the shaft, which leads to the deflection of the shaft Can be eliminated at once. In addition, since the molded body is placed horizontally so as to take the largest installation area, its own weight acts uniformly in the longitudinal direction of the molded body, and it is easy to obtain a stable warpage correcting effect.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
FIGS. 2A and 2B show a magnet roll formed by injecting a resin magnet composition into a mold. The magnet roll 1 has a circular cross-sectional shape at both ends of a roll body 2. The shaft portions 3 and 4 are formed so as to protrude, and are integrally formed using a resin magnet. Although not shown, a cut-out portion for positioning or driving force transmission may be formed in the one shaft portion 3 or 4 or both shaft portions 3 and 4 for implementation. The present invention is also applicable to a magnet roll 1 in which the roll portion 2 is not a cylinder but a polygonal pillar, or a magnet in which the center of the roll portion 2 and the center of the shaft portions 3 and 4 are intentionally eccentric. Can be similarly applied.
[0010]
The resin magnet composition constituting the magnet roll 1 is mainly composed of a magnetic powder and a binder for binding the magnetic powders together, and a silane or titanate coupling agent for strengthening the binding, It is a mixture containing a small amount of a lubricant for improving the properties, a stabilizer for preventing the thermal decomposition of the binder, etc.It is also possible to add a flame retardant, a reinforcing agent, etc. if necessary. Rare earth-based (SmCo-based, NdFeB-based), MnAIC-based, alnico-based, SmFeN-based, and the like can be selected. As the binder, a thermoplastic resin, a thermosetting resin, a low melting point alloy, or the like can be used.
[0011]
The magnet roll 1 is used as a developing roll and a cleaning roll in an electrophotographic developing device such as a copying machine, a facsimile, and a printer, but can be used for other purposes.
[0012]
Next, the manufacturing apparatus of the magnet roll 1 will be described. As shown in FIGS. 1 (a) and (b) and FIGS. 2 (a) and 2 (b), the roll body 2 of the magnet roll 1 is formed. A cylindrical main mold 5 on the fixed side; an end mold 6 disposed at one end of the main mold 5 for forming the shaft 4 of the magnet roll 1; 5, and move back and forth with the injection of the molten resin magnet into the molding space 8 formed by the main molding die 5, the end of the magnet roll 1, That is, the slide mold 7 for forming the shaft portion 3 constitutes a molding die for the magnet roll. After the molten resin magnet is completely injected into the molding space 8 as shown in FIG. 1B and provided in the main mold 5, the magnetic particles of the magnetic particles are solidified until the molten resin magnet solidifies. And a magnetic field orienting means 9 for performing magnetization and orientation. The number of the magnetic field orienting means 9 may be any number, and the magnetic field orienting means 9 may be of various existing configurations such as an electromagnet. The molten resin magnet is supplied from a not-shown injection cylinder or the like into the molding space 8 through the injection port 10 shown in the figure. The magnetization and orientation by the magnetic field orientation means 9 may be performed at the same time as the injection of the molten resin magnet is started, and the start timing may be any time.
[0013]
Next, a method of forming the magnet roll 1 will be described.
As shown in FIG. 1A, after driving the actuator 11 for moving the slide die 7 to move the slide die 7 to the forward position, the molten resin is injected into the die through the injection port 10. Start magnet injection. As the actuator 11, for example, an air compressor, a hydraulic cylinder, a pneumatic cylinder, a screw screw, a rack and pinion gear, a linear motor, or the like can be used. Next, as shown in FIG. 1B, the molding space 8 is filled with the molten resin magnet while the slide die 7 is retracted to the retracted position by the combined force of the injection pressure of the molten resin magnet and the driving force of the actuator 11. You do it. When a hydraulic cylinder is used as the actuator 11, the hydraulic oil is leaked while being squeezed to apply a braking force to the backward movement of the slide die 7, so that the molten resin magnet is filled in the molding space 8 without gaps. It becomes possible to go. However, a braking force applying means for applying a braking force by friction or the like may be provided to apply the braking force when the slide die 7 moves backward. Further, the slide die 7 may be retracted while applying a braking force by the actuator 11 according to the injection injection speed of the molten resin magnet. Further, when the molten resin magnet is filled, the driving by the actuator 11 may be stopped. When the injection of the molten resin magnet is completed, the magnetic field orienting means 9 magnetizes and orients the magnetic particles until the molten resin magnet is solidified.
[0014]
After the injection-fused molten resin magnet is solidified, the end mold 6 is moved away from the main mold 5 as shown in FIG. As shown in (b), the magnet roll 1 is detached. The main mold 5 may be moved away from the end mold 6.
[0015]
By gathering a plurality of the magnet rolls 1 (18 in the figure) at one place in the same direction as described above, as shown in FIGS. 3A and 3B, the mutual magnetic attractive force is reduced. After being bundled at random by using, it is placed on a mounting table 12 having a horizontal surface at the upper end, and is cooled, so that the warpage of each magnet roll 1 can be corrected.
The principle by which this warpage can be corrected is shown in FIGS. That is, in FIG. 4A, the two ends of the magnetic poles (N-pole and S-pole) formed on the magnet roll 1 are attracted to each other by the attraction force between the two ends where the warpage occurs, and the warp is caused to approach the sides closer to each other. In FIG. 4B, conversely, the warped central portions are drawn closer to each other to correct the warp. 4 (a) and 4 (b), the degree of warpage is illustrated in a state where the degree of warpage is large for easy understanding, but in reality it is very small. Also, FIGS. 4A and 4B show the case of two poles for the sake of simplicity, but the case of four poles as shown in FIGS. The number of poles or five or more poles may be used.
[0016]
A bundle of a plurality (16, 30, 40, 60, 70) of the magnet rolls 1 formed as described above, and a single one as a comparative example were respectively warped average and longitudinal. The magnetic force variations (zone values) in the directions were measured and are shown in Table 1. In the measurement, a predetermined number of magnet rolls 1 were randomly extracted, the number of each measurement was measured 10 times, and the average value of the 10 times was tabulated. In particular, in the case of one comparative example, three examples are given because the measurement error is large. The variation on the right side of the average warpage amount in the table indicates the difference between the maximum value and the minimum value of the warpage amount, and the variation on the right side of the average zone value indicates the difference between the maximum value and the minimum value of the zone value. .
5 and 6 were prepared based on Table 1.
[0017]
[Table 1]

[0018]
In FIG. 5, the data of the comparative product 1 and the present invention products 1 to 5 are indicated by the solid line of a, and the straightening effect of the warp is large when the number between 10 and 40 is more than 40. It can be seen that is decreased. And b in the figure shows the result of measuring the magnet rolls 1 which were bundled into a predetermined number, heat-treated in an environment of 80 to 150 ° C. for 3 to 10 hours, and cooled down over 10 hours, and It can be seen that as the number increases, the amount of warpage decreases.
FIG. 6 shows that the zone value increases as the amount of warpage increases.
FIG. 7 is a graph showing the heating temperature and the amount of warpage. It can be seen that the higher the heating temperature and the longer the heating time, the smaller the amount of warpage. However, as shown in FIG. If the heating temperature is C or more and the heating time is 5 hours or more, the axial strength is reduced, and it is necessary to consider the heating temperature and the heating time.
As is clear from Table 1 and FIG. 5, the average warpage is preferably 300 μm or less, and the average zone value is preferably 4.0 mT or less.
[0019]
Further, in the above embodiment, the shaft portion and the roll portion are integrally formed, but the present invention is applicable to a shaft insert type magnet roll in which a metal or synthetic resin shaft is inserted. Can be.
[0020]
【The invention's effect】
According to the first aspect of the present invention, the formed magnet roll is moved in the longitudinal direction and taken out, so that there is no parting line as in the case of the split mold. The generation of burrs in the longitudinal direction can be eliminated, the roundness can be increased, and a highly completed magnet roll can be provided. Then, by bundling a plurality of magnet rolls using the magnetic attraction force provided on the magnet roll formed in this way, each magnet roll is attracted to each other using the magnetic force of each magnet roll. Since the warpage generated in the roll can be corrected, the warpage can be corrected without providing a large-scale warpage correction mechanism or the like, which is advantageous in cost.
[0021]
According to the second aspect, when the surface temperature of the molded body in the mold is cooled to 80 to 150 ° C., the magnet roll is taken out and cooled in a state where 10 to 40 magnet rolls are bundled. It is clear from the measurement results that this is optimal.
[0022]
According to the third aspect, when correcting the warpage of the molded article which has been cooled down to 30 ° C. or less, bundle 10 or more pieces and heat them again to 80 to 150 ° C., and then change the state to 3 to 10 ° C. If the temperature is maintained and the cooling is performed for 5 hours or more, a higher correction effect can be obtained, and a more accurate magnet roll can be obtained.
[0023]
According to the fourth aspect, the bundled compacts are placed horizontally so that the longitudinal direction thereof is horizontal, and the warp is corrected. This makes it difficult to support the compacts in the case of placing them vertically and adds weight to the shaft. It can be eliminated at a stroke that the shaft portion runs. Moreover, since the molded body is placed horizontally so that it can take the largest installation area, its own weight acts uniformly in the longitudinal direction of the molded body, and it is easy to obtain a stable warping correction effect. Is the best.
[Brief description of the drawings]
FIG. 1A is a cross-sectional view of a mold showing a start state of injection of a molten resin magnet, and FIG. 1B is a cross-sectional view of a die showing a completion state of injection of a molten resin magnet.
FIG. 2A is a cross-sectional view of a mold showing a state in which an end mold is separated from a main mold, and FIG. 2B is a mold showing a state in which a formed magnet roll is detached. Sectional view.
3A is a front view showing a state in which a number of magnet rolls are appropriately bundled by their own magnetic attraction and mounted on a mounting table, and FIG. 3B is a side view thereof.
4A is an explanatory view of correcting both ends of a magnet roll by magnetic attraction, and FIG. 4B is an explanatory view of trying to correct the center of the magnet roll by magnetic attraction.
FIG. 5 is a graph showing the relationship between the number of bundles and the average amount of warpage.
FIG. 6 is a graph showing a relationship between a warpage amount average and a zone value average.
FIG. 7 is a graph showing heat treatment time and warpage.
FIG. 8 is a graph showing heating temperature and shaft breaking strength.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Magnet roll 2 Roll body part 3, 4 Shaft part 5 Main molding die 6 End molding die 7 Slide die 8 Molding space 9 Magnetic field orienting means 10 Inlet 11 Actuator 12 Mounting table

Claims (4)

After applying a magnetic field of two or more poles to a resin magnet composition containing magnetic powder and a binder as main components by injection into a molding space formed by a mold by a magnetic field orientation means provided in the mold. In the method for manufacturing a magnet roll that is removed from a mold, the mold includes, as the mold, one of a main molding die for forming a roll body of the magnet roll and one of shaft portions formed at both ends of the magnet roll. It comprises an end molding die disposed at one end of the main molding die to form a shaft, and a slide die slidably disposed within the main molding die to form the other shaft. Then, a magnet roll is formed using the material, and after this, the slide die is protruded into the molding space to take out the magnet roll out of the mold. Bundled by adsorbing the magnetic attraction force of Luo itself, the magnet roll of the warp correction method characterized by performing the correction of warpage by holding the bundled state. 2. The warpage of a magnet roll according to claim 1, wherein the surface temperature of the formed body when the formed magnet roll is removed from the mold is set to 80 to 150 [deg.] C., and cooling is performed in a state where 10 to 40 pieces are bundled. Straightening method. The warp correction of the magnet roll according to claim 1, wherein the heat treatment is performed on the molded body bundled into 10 or more pieces in an environment of 80 to 150 ° C for 3 to 10 hours, and the cooling is performed over 5 hours or more. Method. 2. The method for correcting warpage of a magnet roll according to claim 1, wherein the bundled formed body is placed horizontally so that its longitudinal direction is horizontal, and the warpage is corrected.

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