Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
  • B29C45/17—Component parts, details or accessories; Auxiliary operations
  • B29C45/26—Moulds
  • B29C45/27—Sprue channels ; Runner channels or runner nozzles
  • B29C45/2701—Details not specific to hot or cold runner channels
  • B29C45/2708—Gates
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
  • G03B15/00—Special procedures for taking photographs; Apparatus therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
  • B29C45/0025—Preventing defects on the moulded article, e.g. weld lines, shrinkage marks
  • B29C2045/0027—Gate or gate mark locations
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
  • B29C45/0025—Preventing defects on the moulded article, e.g. weld lines, shrinkage marks
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/13—Hollow or container type article [e.g., tube, vase, etc.]
  • Y10T428/1352—Polymer or resin containing [i.e., natural or synthetic]

Definitions

• the present invention relates to a dome cover used for a dome type surveillance camera or the like.
• Such a surveillance camera has a dome cover for accommodating and protecting the lens.
• the dome cover is typically made of transparent grease.
• the dome cover includes a substantially hemispherical dome having an opening, and a flange provided at the peripheral edge of the opening.
• the lens of the surveillance camera rotates in the pan or tilt direction while being accommodated in the dome cover.
• the surveillance video is shot through the transparent dome cover.
• This dome cover is required to have high optical performance. For example, it is required that high-quality images and high-resolution images can be obtained with a power image taken through a dome cover.
• Such a dome type camera is disclosed in, for example, Japanese Patent Laid-Open No. 2005-300659 (pages 4-6, FIG. 2).
• Such a dome cover is manufactured, for example, by injection molding.
• a cavity having a shape corresponding to the shape of the dome cover is formed between the upper mold and the lower mold of the mold used for injection molding.
• a gate port for injecting grease is provided at a position corresponding to the flange portion of the dome cover so that a gate mark remains in the dome portion of the molded dome cover.
• the gate opening is provided on the side of the cavity (the circumferential portion of the substantially circular cavity in plan view). With the side of the cavity, the molten resin heated and injected from the gate of the injection mold is poured into the cavity, and the molten resin is cooled and cured. In this way, the dome cover is manufactured by injection molding.
• Such an injection mold is disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-285351 (page 3-6, FIG. 2).
• the gate loca provided on the side of the cavity also injects the grease.
• the side of the cavity (a substantially circular
• the grease injected from one circumference of the tee flows around the center of the cavity (the part corresponding to the top of the dome cover) and goes to the exit of the other circumference of the cavity. And flow.
• unevenness in the pressure and temperature of the resin in the cavity where the flow of the resin is uniform occurs near the gate opening and the outlet part. Therefore, in the dome cover manufactured by the conventional method, uneven molding occurs in the part corresponding to the gate opening and the exit part, and optical unevenness (reduction of image quality, resolution, etc. ) May occur.
• An object of the present invention is to provide a method of manufacturing a dome cover that can suppress the occurrence of partial molding unevenness in the dome cover.
• One aspect of the present invention is a method for manufacturing a dome cover.
• a shape of the dome cover is provided between the first mold and the second mold for injection molding.
• a gate opening for pouring molten resin is provided at a position corresponding to the top of the dome cover of the first mold, and the gate loca also injects molten resin into the cavity to form a dome.
• the force bar is manufactured by injection molding.
• Another aspect of the present invention is a dome cover, and the dome cover is manufactured using the method for manufacturing the dome cover.
• dome type camera Another aspect of the present invention is a dome type camera, and the dome type camera includes the dome force bar and a camera provided inside the dome cover.
• Fig. 1 shows a mold for injection molding of a dome cover according to an embodiment of the present invention (game Cross-sectional view of the state where the bin member is pulled out)
• FIG. 2 is a cross-sectional view of a dome cover injection mold (with a gate bin member inserted) according to an embodiment of the present invention.
• FIG. 3 is a cross-sectional view of a dome cover manufactured in an embodiment of the present invention.
• FIG. 4 is a perspective view of the dome cover manufactured in the embodiment of the present invention.
• FIG. 5 is a front view of a dome type camera according to an embodiment of the present invention.
• FIG. 6 is a side view showing a state of post-processing of the dome cover in the embodiment of the present invention.
• FIG. 7 is a perspective view showing a state of post-processing of the dome cover in the embodiment of the present invention.
• FIG. 8 is an explanatory view of a modification of the dome cover according to the embodiment of the present invention.
• Fig. 9 shows a shooting state of the dome type camera according to the embodiment of the present invention (horizontal direction T
• FIG. 10 is a side view for explaining the photographing state of the dome type camera (the photographing state at the WIDE end in the downward direction) in the embodiment of the present invention.
• a dome cover shape cavity is formed between the first mold and the second mold for injection molding, and the top of the dome cover of the first mold is formed.
• a gate port for injecting molten resin is provided at a position corresponding to the top, and the gate loca also has a structure for injecting molten resin into the cavity and manufacturing the dome cover by injection molding.
• a post-processing apparatus having a mirror-finished contact surface is used, and the contact surface is pressed against the zenith portion of the dome cover manufactured by injection molding. It is also possible to melt the grease at the top of the cover and transfer the mirror surface shape of the contact surface of the post-processing device to the top of the dome cover.
• the shape of the abutting surface of the post-processing apparatus that has been mirror-finished is transferred to the zenith portion of the dome cover, so that the zenith portion of the dome cover can be post-processed.
• the gate opening trace gate trace
• the gate trace can be easily made inconspicuous by post-processing.
• the dome cover manufacturing method of the present invention may have a configuration in which the resin at the zenith portion of the dome cover is melted by ultrasonically vibrating the contact surface of the post-processing apparatus. .
• the grease on the surface of the zenith portion of the dome cover can be removed only during ultrasonic vibration. Melt. Therefore, the degree of melting of the resin can be easily controlled as compared with the case where the resin is heated and melted. In addition, when the ultrasonic vibration stops, the grease at the top of the dome force bar hardens. Therefore, the time required for curing the resin can be shortened, and the time required for post-processing can be shortened.
• the dome cover manufacturing method of the present invention may have a configuration in which the contact surface of the post-processing device is vibrated along the tangential direction at the zenith portion of the dome cover.
• the gate port is provided with a gate pin member that is detachably inserted, and when pouring the grease, the gate pin member is pulled out to the pulling position, After opening the mouth and injecting the grease, the gate pin member is inserted to the insertion position, the gate port is closed with the gate pin member, and the inner surface of the first mold around the gate port and the front end surface of the gate pin member are continuous. You may have the structure which forms a surface.
• the gate port located at the top of the dome cover is closed with the gate pin member, and a continuous surface is formed at the tip surface of the gate pin member.
• the gate trace at the top can be reduced.
• the dome cover of the present invention has a configuration including a dome cover manufactured by using the above manufacturing method.
• a dome-type camera of the present invention has a configuration including the dome cover described above and a camera provided inside the dome cover.
• FIGS. 1 and 2 show a mold for injection molding of a dome cover according to an embodiment of the present invention.
• . 1 and 2 are cross-sectional views of the injection mold as viewed from the side.
• FIG. 3 is a cross-sectional view of the dome cover manufactured by injection molding as seen from the side, and
• FIG. 4 is a perspective view of the dome cover.
• FIG. 5 is a front view of a dome type camera provided with a dome cover.
• the dome-type camera 1 houses and protects the main body 3 having the mounting portion 2, the lens 5 of the surveillance camera 4 provided at the lower portion of the main body 3, and the lens 5.
• a dome cover 6 is provided.
• the dome type camera 1 is attached to the ceiling of the facility, for example, by the attachment portion 2.
• the main body 3 is provided with a pan / tilt mechanism 7 for turning the lens 5 of the surveillance camera 4 in the pan direction (horizontal direction) and the tilt direction (vertical direction).
• the lens 5 is composed of a plurality of lenses assembled in a lens barrel.
• An image sensor such as a CCD is incorporated behind the lens barrel. In this way, the surveillance camera 4 is configured.
• the dome cover 6 is attached to the main body 3 in a state where the lens 5 is accommodated.
• the dome cover 6 includes a substantially hemispherical dome portion 9 having an opening portion 8 and a flange portion 10 that protrudes outward from the periphery of the opening portion 8. And prepare.
• a dome cover 6 having a dome portion 9 having a shape combining a hemisphere and a cylinder is shown as an example.
• the cylindrical portion of the dome portion 9 is not always necessary.
• the dome portion 9 of the dome cover 6 may be hemispherical. In FIG. 1 and FIG. 2, which will be described later, the cylindrical portion of the substantially hemispherical dome cover 6 is not shown for the sake of simplicity.
• the optical axis of the lens 5 is offset from the center of the hemisphere of the dome cover 6 toward the zenith side of the dome cover 6 with the lens 5 oriented in the horizontal direction. (See Fig. 8). By this offset, even when the lens 5 is oriented in the horizontal direction, the lens 5 that is not obstructed by the main body 3 (the camera angle of view is lost by the main body 3) can photograph the front.
• the dome cover 6 is made of transparent resin.
• a transparent synthetic resin such as polycarbonate (PC), acrylic, acrylonitrile butadiene styrene (ABS), or the like is used as the material of the dome cover 6.
• the dome cover 6 is required to have high optical performance. For example, it is required that the camera image taken through the dome cover 6 has high image quality and resolution.
• the injection mold 11 includes an upper mold 12 and a lower mold 13 that are opened and closed vertically.
• a substantially hemispherical cavity 14 corresponding to the shape of the dome cover 6 is formed between the upper mold 12 and the lower mold 13.
• a gate port 16 for injecting molten resin is provided at a position corresponding to the zenith 15 of the dome cover 6 of the upper mold 12.
• a cooling medium flow path 17 for flowing a cooling medium is provided outside the cavity 14 of the upper mold 12 (a position corresponding to the peripheral portion of the outer surface of the dome cover 6).
• a gate pin member 18 is removably inserted into the gate port 16.
• the gate pin member 18 is slidable in the vertical direction between the drawing position shown in FIG. 1 and the insertion position shown in FIG.
• the gate port 16 of the upper mold 12 is open, and it is possible to inject grease into the cavity 14 from the gate port 16. It is.
• the gate pin member 18 when the gate pin member 18 is inserted to the insertion position, the gate port 16 of the upper die 12 is blocked by the gate pin member 18, and the upper inner peripheral surface 19 around the gate port 16 is closed.
• a pin tip surface 20 of the gate pin member 18 form a continuous surface. That is, as shown in FIG. 2, the upper mold inner peripheral surface 19 around the gate port 16 and the pin tip surface 20 of the gate pin member 18 are in a continuous state without a step.
• the upper mold 12 of the injection mold 11 can be said to be an outer mold for molding the outer portion of the dome cover 6 and corresponds to the first mold of the present invention.
• the lower mold 13 of the injection mold 11 can be said to be an inner mold for molding the inner part of the dome cover 6, and corresponds to the second mold of the present invention.
• FIG. 6 and FIG. 7 show a state in which post-processing is performed on the dome cover 6 manufactured by injection molding.
• FIG. 6 is a side view showing a state in which the zenith portion 15 of the dome cover 6 is post-processed
• FIG. 7 is a perspective view showing a state in which the zenith portion 15 of the dome cover 6 is post-processed.
• an ultrasonic welder device 21 is used as a post-processing device that performs post-processing on the zenith portion 15 of the dome cover 6.
• the ultrasonic folder device 21 includes an apparatus main body (not shown), an ultrasonic vibrator that is provided in the apparatus main body and oscillates ultrasonic vibrations, and a horn member to which the ultrasonic vibration generated by the ultrasonic vibrator is transmitted. 22 is provided.
• the horn member 22 of the ultrasonic welder device 21 is configured to vibrate in the horizontal direction (left-right direction in FIG. 6) along the tangential direction at the zenith portion 15 of the dome cover 6.
• the horn member 22 of the ultrasonic welder device 21 has a convex tip convex portion 23.
• the lower surface 24 of the tip convex portion 23 of the horn member 22 has a spherical shape (concave spherical shape) along the spherical shape (convex spherical shape) of the upper surface of the apex portion of the dome cover 6.
• the lower surface 24 of the tip convex portion 23 of the horn member 22 is given a mirror surface force.
• the ultrasonic welder device 21 corresponds to the post-processing device of the present invention
• the lower surface 24 of the tip convex portion 23 of the horn member 22 corresponds to the contact surface of the present invention.
• the dome cover 6 When the dome cover 6 according to the embodiment of the present invention is manufactured by injection molding, first, as shown in FIG. 1, the upper mold 12 and the lower mold 13 of the injection mold 11 are closed, and A cavity 14 is formed between the lower mold 13 and the lower mold 13. Next, the gate pin member 18 is pulled out to the pulling position, and the gate port 16 is opened. Thereafter, the melted resin is poured into the cavity 14 through the gate port 16. At this time, the grease injected from the gate port 16 isotropically and uniformly from the center of the cavity 14 (the part corresponding to the zenith 15 of the dome cover 6) toward the circumference of the cavity 14. Flowing.
• the gate pin member 18 is inserted to the insertion position, and the gate is inserted.
• the gate 16 is closed with the gate pin member 18.
• the horn member 22 of the ultrasonic welder device 21 is vibrated in the horizontal direction (horizontal direction in FIG. 6), so that the top 15 of the dome cover 6 Melt the rosin again. Then, the mirror shape force of the lower surface 24 of the tip convex portion 23 of the pressed horn member 22 is transferred to the zenith portion 15 of the dome cover 6. Thereafter, the oscillation of the ultrasonic wave from the ultrasonic welder device 21 is stopped, and the grease on the zenith 15 of the dome cover 6 is hardened again.
• the zenith 15 of the dome cover 6 is post-processed.
• the gate mark 25 can be made inconspicuous.
• the thin dome cover 6 having the zenith portion 15 as shown in FIG. 8 can be easily manufactured. is there.
• the center of the hemisphere inside the dome part 9 is offset to the zenith side of the dome part 9 with respect to the center of the hemisphere outside the dome part 9.
• the dome thickness at the top 15 of the dome 9 is smaller than the dome thickness in the horizontal direction of the dome (thickness at the periphery of the dome 9).
• the optical path difference at the dome portion 9 is reduced.
• the aberration due to the optical path difference is reduced, and the image quality of the camera image is improved.
• the position corresponding to the flange portion of the dome cover also has the cavity when the grease is injected. Since it is narrow at the zenith, the injected resin does not flow into the zenith of the cavity, and molding defects occur at the zenith of the cavity. In contrast, in the manufacturing method of the present embodiment, grease is poured from the gate port 16 located at the top 15 of the dome cover 6. Since the injected grease flows smoothly through the cavity 14, molding defects do not occur at the zenith 15 of the dome cover 6.
• the gate mark 25 remains at the zenith 15 of the dome cover 6.
• the dome cover 6 The gate mark 25 can be made inconspicuous by post-processing the zenith 15 of the gate. Therefore, the method of manufacturing the dome cover 6 of the present embodiment is optimal for manufacturing the thin dome cover 6 having the zenith portion 15 as shown in FIG.
• the image quality of the camera image taken at the TELE end (the maximum telephoto focal length of lens 5) with the lens 5 of the surveillance camera 4 in the horizontal direction was evaluated.
• a conventional dome cover was used as a comparative example.
• the dome cover 6 of the present embodiment is formed by injecting resin from the gate 16 located at the zenith 15 of the dome cover 6 and injection molding.
• the dome cover of the comparative example is injection-molded by injecting a gate locus resin on the side corresponding to the flange portion of the dome cover, that is, the cavity.
• the grease injected from the center of the cavity 14 (the part corresponding to the zenith 15 of the dome cover 6) is uniformly directed toward the circumference of the cavity 14. Therefore, the unevenness of the pressure and temperature of the resin in the cavity 14 is suppressed, and the molding unevenness of the manufactured dome cover 6 is suppressed.
• the lens 5 of the surveillance camera 4 is moved directly downward (the top of the dome cover 6).
• the gate mark 25 was conspicuous in the camera image at the WIDE end (the maximum wide-angle focal length of the lens 5) toward the top.
• grease was injected from the gate 16 located at the zenith portion 15 of the dome cover 6 as in the present embodiment, but a dome cover was used after applying a post-treatment.
• the portion of the gate mark 25 at the zenith 15 of the dome cover 6 becomes opaque, and the other side of the gate mark 25 can be seen through. I helped.
• the gate mark 25 at the zenith 15 of the dome cover 6 is not noticeable, and the other side of the gate mark 25 can be seen. From this result, it was confirmed that the gate mark 25 can be made small and inconspicuous by performing post-processing on the zenith portion 15 of the dome cover 6.
• molten resin is injected into the cavity 14 from the gate port 16 provided at a position corresponding to the zenith portion 15 of the dome cover 6. As a result, it is possible to suppress the occurrence of partial molding unevenness in the manufactured dome cover 6.
• the grease injected from the center part of the cavity 14 flows uniformly toward the circumferential part of the cavity 14. It is.
• the resin into which the center point force of the point-symmetric shape 14 is injected flows isotropically (point-symmetric) toward each part of the point-symmetric shape 14. Therefore, it is possible to suppress the occurrence of unevenness in the pressure and temperature of the resin within the cavity 14 and to suppress the formation of unevenness in the manufactured dome cover 6.
• the shape of the abutment surface of the post-processing device that has been mirror-finished is transferred to the zenith portion 15 of the dome cover 6, thereby transferring the rear surface to the zenith portion 15 of the dome cover 6.
• the gate trace 25 can be easily made inconspicuous by post-processing by transfer.
• the post-processing by transfer can be automated by the machine. Productivity of cover 6 is high.
• the zenith portion 15 of the dome cover 6 is only during ultrasonic vibration.
• the surface grease melts. Therefore, it is possible to easily control the degree of melting of the resin, which does not require difficult temperature control, as compared with the case where the resin is heated and melted.
• the ultrasonic vibration stops the grease on the zenith 15 of the dome cover 6 is cured. Therefore, the time required to cure the resin can be shortened, and the time required for post-processing can be shortened. For example, when the resin is melted by ultrasonic vibration, the time required for melting and curing the resin is about 0.1 second. Therefore, the time required for post-processing can be significantly shortened, and the cost of the dome cover 6 can be reduced because the mass productivity of the dome cover 6 is high.
• the contact surface of the post-processing device is vibrated along the tangential direction at the zenith portion 15 of the dome cover 6.
• the grease on the zenith 15 of the dome cover 6 can be easily melted by the friction generated between the contact surface that vibrates ultrasonically and the zenith 15 of the dome cover 6.
• the vibration direction of the contact surface is the tangential direction at the zenith portion 15 of the dome cover 6, the vibration due to the ultrasonic wave is compared with the case of vibrating along the normal direction of the zenith portion 15 of the dome cover 6. Energy is efficiently converted to friction energy.
• the gate port 16 located at the zenith 15 of the dome cover 6 is closed with the gate pin member 18, and the upper mold inner peripheral surface 19 and the pin tip surface Since a continuous surface is formed with 20, the gate mark 25 at the zenith 15 of the dome cover 6 can be reduced.
• the gate pin member 18 is used to block the gate port 16
• a large cylindrical column mark 25 is formed on the zenith portion 15 of the dome cover 6 due to the grease remaining inside the gate port 16.
• the gate mark 25 at the zenith portion 15 of the dome cover 6 is a small gate mark 25 having only a circular shaped part line between the gate port 16 and the gate pin member 18.
• the ultrasonic welder device 21 is used as a post-processing device, and the horn member 22 is ultrasonically vibrated to melt the resin of the zenith portion 15 of the dome cover 6.
• the scope of the present invention is not limited to this. For example, heat the resin at the zenith 15 of the dome cover 6 to melt it.
• the method of manufacturing a dome cover according to the present invention has an effect of suppressing the occurrence of partial molding unevenness in the manufactured dome cover, and has a dome-type monitoring power mela It is useful as a method for manufacturing a dome cover used for the like.

Landscapes

• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Moulds For Moulding Plastics Or The Like (AREA)
• Injection Moulding Of Plastics Or The Like (AREA)
• Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=38162947

Family Applications (1)

Country Status (6)

Families Citing this family (10)

Citations (6)

Family Cites Families (8)

• 2005
  • 2005-12-14 JP JP2005360508A patent/JP4257861B2/ja not_active Expired - Fee Related
• 2006
  • 2006-12-13 CN CN2006800474853A patent/CN101351319B/zh not_active Expired - Fee Related
  • 2006-12-13 EP EP06834592.5A patent/EP1972422A4/en not_active Withdrawn
  • 2006-12-13 US US12/096,038 patent/US8142084B2/en not_active Expired - Fee Related
  • 2006-12-13 WO PCT/JP2006/324837 patent/WO2007069641A1/ja not_active Ceased
  • 2006-12-13 RU RU2008128481/05A patent/RU2417885C2/ru not_active IP Right Cessation

Patent Citations (6)

Also Published As

Similar Documents

Legal Events