JP2006206307A - Roller, recording device having the roller, and method of manufacturing the roller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the rigidity of a flange from being lowered due to its shrinkage by a gas circulated to the rear side of the flange when a roller having the flange projected from the outside of its hollow shaft is injection-molded by the gas. <P>SOLUTION: This resin carrying roller comprises the hollow shaft and the flange radially projected from the hollow shaft, and is manufactured by the injection molding with the gas. The roller comprises a corner R formed in a boundary between the shaft and the flange with a dimension larger than the wall thickness of the shaft. The dimension of the corner R may be larger than the wall thickness of the flange. Also, the wall thickness of the flange may be larger than the wall thickness of the shaft. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a roller, a recording apparatus including the roller, and a method for producing the roller.

2. Description of the Related Art Conventionally, as a resin discharge roller for discharging a recording material of a recording apparatus, a technique for expanding the diameter of a roller shaft by forming the roller shaft hollow by a gas injection method is known (for example, (See Patent Document 1). According to this technique, the bending rigidity and torsional rigidity of the discharge roller can be increased by increasing the diameter of the roller shaft.
JP 2003-335430 A

  However, in the above technique, when gas injection molding is performed on a roller having a flange protruding outside the hollow shaft, the gas may flow around the back side of the flange in the hollow portion, and the thickness of the base of the flange may be insufficient. It was. In this case, there is a problem that the rigidity of the flange is insufficient.

  In order to solve the above problems, in the first embodiment of the present invention, there is provided a resin roller that includes a hollow shaft and a flange projecting in the diameter direction of the hollow shaft, and is produced by gas injection molding. Thus, a roller is provided in which an angle R having a dimension larger than the wall thickness of the shaft is formed at the boundary between the shaft and the flange. According to such a roller, a thin portion is not formed at the base of the flange. Therefore, the rigidity of the flange can be ensured.

  According to a second aspect of the present invention, there is provided a resin roller that includes a hollow shaft and a flange that projects in a diameter direction of the hollow shaft, and is produced by gas injection molding. A roller is provided in which a C-plane with dimensions larger than the wall thickness of the shaft is formed at the boundary. According to such a roller, a thin portion is not formed at the base of the flange. Therefore, the rigidity of the flange can be ensured.

  In the rollers of the first and second embodiments, the dimension of the corner R or C surface may be larger than the thickness of the flange. Further, the thickness of the flange may be larger than the thickness of the shaft. As described above, even if the base of the flange has a shape that is particularly easy to close at the time of molding, the roller does not form a thin portion at the base of the flange. Therefore, the rigidity of the flange can be ensured.

  According to a third aspect of the present invention, there is provided a recording apparatus for recording on a recording material, which is formed at a hollow shaft, a flange projecting in the diameter direction of the hollow shaft, and a boundary between the shaft and the flange. A resin roller having an angle R larger than the thickness of the shaft and produced by gas injection molding, and rotating the roller while the roller is in contact with the material to be recorded. A recording apparatus is provided that includes a transport unit that transports a recording material to a recording area in which recording is performed. According to such a recording apparatus, since the rigidity of the flange in the roller is high, the recording object can be conveyed with high accuracy.

  According to a fourth aspect of the present invention, there is provided a recording apparatus for recording on a recording material, which is formed at a hollow shaft, a flange projecting in the diameter direction of the hollow shaft, and a boundary between the shaft and the flange. A resin roller having a C surface having a dimension larger than the thickness of the shaft and produced by gas injection molding, and the roller is driven to rotate while the roller is in contact with the material to be recorded. A recording apparatus is provided that includes a transport unit that transports a recording material to a recording area in which recording is performed. According to such a recording apparatus, since the rigidity of the flange in the roller is high, the recording object can be conveyed with high accuracy.

  According to a fifth aspect of the present invention, there is provided a method for producing a resin roller comprising a hollow shaft and a flange projecting in the diametrical direction of the hollow shaft, and forming a boundary between the shaft and the flange. There is provided a production method for producing a roller by gas injection molding using a mold in which an angle R having a dimension larger than the thickness of the shaft is formed in a portion. According to such a production method, a thin portion is not formed at the base of the flange. Therefore, it is possible to produce a roller having a high flange rigidity.

  According to a sixth aspect of the present invention, there is provided a production method for molding a resin roller comprising a hollow shaft and a flange projecting in the diameter direction of the hollow shaft, wherein the boundary between the shaft and the flange is molded. There is provided a production method for producing a roller by gas injection molding using a mold in which a C surface having a dimension larger than the thickness of the shaft is formed in the portion to be formed. According to such a production method, a thin portion is not formed at the base of the flange. Therefore, it is possible to produce a roller having a high flange rigidity.

  The above summary of the invention does not enumerate all the necessary features of the present invention, and sub-combinations of these feature groups can also be the invention.

  Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the scope of claims, and all combinations of features described in the embodiments are included. It is not necessarily essential for the solution of the invention.

  FIG. 1 shows an appearance of an ink jet printer 100 according to this embodiment. The ink jet printer 100 includes an upper housing 101 and a lower housing 102 that are substantially rectangular parallelepiped. The upper housing 101 and the lower housing 102 are fixed by a snap fit. A paper feed port 103 is formed on the rear side of the upper housing 101. The paper feed port 103 is provided with a paper feed tray 110 on which stacked sheets are fed. The paper feed tray 110 is disposed so as to protrude obliquely upward and rearward, and holds the paper in an inclined state. A paper discharge port 104 is formed on the front side of the upper housing 101. Disposed on the front side of the upper housing 101 and the lower housing 102 is a sheet discharge stacker 120 on which sheets to be discharged are stacked and placed.

  FIG. 2 is a perspective view showing the internal structure of the ink jet printer 100. On the lower housing 102, a main board 130 for controlling the printer is arranged vertically, and further, a recording means 140 constituting a print engine, a paper supply means 150, a conveying means 160, and the like are arranged. On the main board 130, control elements and storage elements such as CPU, ROM, RAM, and ASIC (not shown) and other various circuit elements are mounted. The recording unit 140 includes a carriage 141, a recording head 142, a carriage motor 143, a timing belt 144, an ink cartridge 146, and the like.

  FIG. 3 is a cross-sectional view of the main part of the ink jet printer 100. The ink jet printer 100 includes a supply unit 150, a conveyance unit 160, a recording unit 140, and a paper discharge stacker 120 in order from the upstream side in the direction in which the paper P, which is a recording object, is conveyed. The supply unit 150 separates one sheet of paper P accumulated on the paper feed tray 110 and feeds it to the transport unit 160. The transport unit 160 transports the paper P downstream while controlling the relative position of the paper P with respect to the recording unit 140. When the recording by the recording unit 140 is completed, the transport unit 160 discharges the paper P to the paper discharge stacker 120.

  The carriage motor 143 drives the timing belt 144 based on control by the main board 130 and scans the carriage 141. The recording head 142 is mounted on the carriage 141 and performs recording by ejecting ink while scanning on the paper P. Each color ink is supplied to the recording head 142 from, for example, four color ink cartridges 146 stored in the carriage 141, for example, yellow, magenta, cyan, and black.

  The supply unit 150 includes a paper feed tray 110, a paper feed guide 111, a paper feed roller 151, a hopper 152, a separation pad 153, and the like. The supply unit 150 rotates the paper feed roller 151 in a state where the paper feed roller 151 is in contact with the recording material, thereby conveying the recording material to a recording area where recording on the recording material is performed. For example, the paper P stacked on the paper feed tray 110 and aligned by the paper feed guide 111 is pressed against the paper feed roller 151 by the separation pad 153 due to the hopper 152 rising as the paper feed roller 151 rotates. The paper P is separated one by one and fed to the transport means 160. The paper feed roller 151 is an example of the transport roller of the present invention.

  The transport unit 160 includes a paper feed roller 161, a driven roller 162, a paper discharge roller 163, a knurled roller 164, a paper feed motor 165, and the like. The paper feed motor 165 drives the paper feed roller 161 and the paper discharge roller 163. The paper feed roller 161 holds the paper P supplied from the supply unit 150 between the driven roller 162 and conveys the paper P to a position facing the recording unit 140. The paper discharge roller 163 sandwiches the paper P between the paper discharge rollers 164 and discharges it to the paper discharge stacker 120. The paper feed roller 161 and the paper discharge roller 163 are examples of the transport roller of the present invention.

  FIG. 4 is a perspective view showing the appearance of the paper feed roller 151. FIG. 5 shows a cross section of the paper feed roller 151. FIG. 6 is a partially enlarged view in which the portion A of FIG. 5 is enlarged. The paper feed roller 151 is formed longer than the maximum width of the recording paper, and includes a hollow shaft 20, a plurality of flanges 10 and 12 projecting in the diameter direction of the hollow shaft 20, and a main roller 16. Yes. The shaft 20 includes a through hole 30 penetrating in the longitudinal direction and a plurality of bearing portions 14. The paper feed roller 151 is made of a resin material and is integrally formed by gas injection molding. A rubber or elastomer (not shown) is wound around the main roller 16 for the purpose of preventing slippage. Thereby, the paper supply roller 151 can reliably convey the paper P. The main roller 16 is provided at a position offset toward the home position side from the center of the shaft 20 in order to correspond to a plurality of sizes of recording materials. The flanges 10 and 12 are provided at a predetermined interval in order to prevent the paper from floating when a paper P having a larger width is loaded. The diameters of the flanges 10 and 12 are substantially the same as the diameter of the main roller 16. Examples of the dimensions of the paper feed roller 151 are as follows. Main roller 16: φ39 (mm), shaft 20: φ8 (mm), shaft 20 thickness: 1.5 (mm), flange 10 thickness: 4 (mm), build-up part 11: R5 (mm).

  When the paper feed roller 151 is produced by gas injection molding, gas flows around the inside of the flange in the hollow portion 30 and sink marks 32 are likely to occur. In particular, when the thickness of the flange is larger than the thickness of the shaft 20, a larger shrinkage 32 is generated at the location. On the other hand, the sheet feeding roller 151 of the present embodiment has a built-up portion 11 formed at the boundary between the shaft 20 and the flange 10. The built-up portion 11 forms, for example, an angle R, and the dimension in the range of the shaft 20 in the axial direction and the diameter direction is larger than the thickness of the shaft 20. According to such a sheet feeding roller 151, a thin portion is not formed at the base of the flange 10. Therefore, the rigidity of the flange 10 can be ensured.

  In addition, it is not necessary to form the build-up part 11 in the boundary with the axis | shaft 20 of the flange 12 thinner than the thickness of the axis | shaft 20. FIG. In the case of gas injection molding, there is no empirical sink on the flange that is thinner than the wall thickness parallel to the injection direction. Therefore, a thin portion is not formed in the thickness of the base of the flange 12, and the rigidity of the flange 12 is ensured. On the other hand, although the main roller 16 is provided thicker than the flange 10, since a plurality of meat thefts are formed as shown in FIG. 4, there is no sink on the hollow portion 30 side. Therefore, it is not necessary to form the built-up portion 11 at the boundary with the shaft 20.

  As another example of the paper feed roller 151, the built-up portion 11 may be a slope such as a C surface instead of the corner R. The dimension of the range of the slope in the axial direction and the diameter direction of the shaft 20 is larger than the thickness of the shaft 20. In this case as well, a thin portion is not formed at the base of the flange 10 as in the above embodiment. Therefore, the rigidity of the flange can be ensured.

  Examples of the material of the feed roller 151 include ABS (acrylonitrile, butadiene, styrene copolymer), PS (polystyrene), POM (polyacetal), modified PPE (polyphenylene ether), PC (polycarbonate), and PBT (polybutylene terephthalate). ), And alloy-based thermoplastic resins are used. Furthermore, in order to further increase the bending rigidity, additives such as GF (glass filler), GB (glass beads), carbon, nylon, potassium titanate and the like are added. The addition amount of this additive is preferably 5% to 50%, and more preferably 10% to 30% for the purpose of further increasing the bending rigidity.

  FIG. 7 is a diagram showing the shape of a mold 200 that produces the paper feed roller 151 by gas injection molding. The mold 200 has a wall in which the range of the shaft 20 in the axial direction and the diametric direction is larger than the thickness of the shaft 20 at the base of the flange forming portion 210 for forming the flange 10, that is, the portion forming the boundary between the shaft 20 and the flange 12. A forming part 211 is formed. The build-up molding part 211 is, for example, a corner R or a C plane. The mold 200 further includes an inlet 202 for injecting molten resin and gas, and an outlet 204 for discharging gas and resin. A waste cavity (not shown) for receiving excess gas and resin is attached to the discharge port 204.

  Gas injection molding of the paper feed roller 151 is performed according to the following procedure. First, the temperature of the cavity of the mold 200 is adjusted to a predetermined temperature, and then molten plastic is injected from the injection port 202 of the mold 200. Subsequently, high-pressure gas is injected from the injection port 202 of the mold 200. As a result, the resin in contact with the inner surface of the cavity is rapidly cooled and pressed by the gas pressure, and is cured in a state of being attached to the inner surface of the cavity. Then, the uncured plastic that is not in contact with the inner surface of the cavity is pushed out from the discharge port 204 by the gas pressure and discharged into the cavity. In this case, sink marks 32 are generated at the base of the flange forming portion 210 as shown in FIG. However, a thin portion is not formed at the base of the flange 10 due to the effect of the build-up portion 211 formed in the mold 200. Therefore, according to the above production method, it is possible to produce the paper feed roller 151 having a high rigidity of the flange 10.

<Comparative Example 1>
8 to 10 show a configuration of a paper feed roller 50 which is a comparative example of the present embodiment. The paper feed roller 50 does not have the built-up portion 11 at the boundary between the flange 10 and the shaft 20. In this case, as shown in the cross-sectional views of FIGS. 9 and 10, the thin portion 51 is formed by sinks 32 generated by the gas flowing around the base of the flange 10. Since the thin portion 51 is locally thinly formed, stress concentration tends to occur when an external force is applied to the flange 10. Therefore, the paper feed roller 50 of this comparative example is less rigid than the paper feed roller 151 shown in FIGS. The paper feed roller 50 of this comparative example is an example of a conventional transport roller. That is, as is clear from comparison with this comparative example, according to this embodiment, it is possible to provide a transport roller having higher rigidity than the conventional one.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

1 is a perspective view illustrating an appearance of an ink jet printer 100 according to an embodiment. 1 is a perspective view showing an internal structure of an ink jet printer 100. FIG. 2 is a cross-sectional view of a main part of the ink jet printer 100. FIG. 3 is a perspective view illustrating an appearance of a paper feed roller 151. FIG. 3 is a cross-sectional view of a paper feed roller 151. FIG. It is the elements on larger scale which expanded the A section of FIG. FIG. 5 is a diagram illustrating a shape of a mold of a paper feed roller 151. It is a perspective view showing the appearance of a paper feed roller 50 which is a comparative example of the present embodiment. 3 is a cross-sectional view of a paper feed roller 50. FIG. It is the elements on larger scale which expanded the B section of FIG.

Explanation of symbols

10 flange, 11 build-up part, 12 flange, 14 bearing part, 16 main flange, 20 shaft, 30 hollow part, 32 sink, 50 feed roller, 51 thin part, 100 inkjet printer, 101 upper housing, 102 lower housing , 103 paper feeding port, 104 paper ejection port, 110 paper feeding tray, 111 paper feeding guide, 120 paper ejection stacker, 130 main board, 140 recording means, 141 carriage, 142 recording head, 143 carriage motor, 144 timing belt, 146 Ink cartridge, 150 supply means, 151 paper feed roller, 160 transport means, 161 paper feed roller, 163 paper discharge roller, 165 paper feed motor, 200 mold, 210 flange molding part, 211 overlay molding part

Claims (8)

A resin roller comprising a hollow shaft and a flange projecting in the diameter direction of the hollow shaft, and produced by gas injection molding,
A roller having an angle R larger than the thickness of the shaft at the boundary between the shaft and the flange. A resin roller comprising a hollow shaft and a flange projecting in the diameter direction of the hollow shaft, and produced by gas injection molding,
A roller in which a C surface having a dimension larger than the thickness of the shaft is formed at the boundary between the shaft and the flange.   The roller according to claim 1 or 2, wherein a dimension of the corner R or the C surface is larger than a thickness of the flange.   The roller according to claim 1, wherein a thickness of the flange is larger than a thickness of the shaft. A recording device for recording on a recording object,
Resin produced by gas injection molding having a hollow shaft, a flange projecting in the diameter direction of the hollow shaft, and an angle R formed at the boundary between the shaft and the flange and having a dimension larger than the thickness of the shaft Made of rollers,
A conveyance unit configured to convey the recording material to a recording area in which recording is performed on the recording material by rotating the roller while the roller is in contact with the recording material; Recording device. A recording device for recording on a recording object,
A resin produced by gas injection molding having a hollow shaft, a flange projecting in the diameter direction of the hollow shaft, and a C-plane formed at the boundary between the shaft and the flange and having a dimension larger than the thickness of the shaft Made of rollers,
A conveyance unit configured to convey the recording material to a recording area in which recording is performed on the recording material by rotating the roller while the roller is in contact with the recording material; Recording device. A method of producing a resin roller comprising a hollow shaft and a flange projecting in the diameter direction of the hollow shaft,
A production method for producing the roller by gas injection molding using a mold in which a corner R having a dimension larger than the thickness of the shaft is formed at a portion where the boundary between the shaft and the flange is molded. A production method for molding a resin roller comprising a hollow shaft and a flange projecting in a diameter direction of the hollow shaft,
A production method for producing the roller by gas injection molding using a mold in which a C surface having a dimension larger than the thickness of the shaft is formed at a portion where the boundary between the shaft and the flange is molded.

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