JP5197183B2 - Powder charge meter - Google Patents

Description

  The present invention relates to a powder charge measuring device that sucks charged powder such as toner as a measurement sample and measures the charge amount and charge amount of the sucked powder.

  As a conventional powder charge amount measuring device, for example, Patent Document 1 includes an insulating container and a conductor container housed in the insulating container, and a filter that captures toner inside the conductor container is a conductor container. A toner charge amount measuring device that measures the charge amount of toner in a suction nozzle, which is a conductor container, having a structure sandwiched between an intake port portion and an exhaust port portion constituting a suction nozzle is described. In this toner charge amount measuring apparatus, the charge amount of the toner sucked into the suction nozzle in the insulating container is measured. Then, the lid of the insulating container is removed, the suction nozzle is taken out from the insulating container, and the weight of the suction nozzle containing the toner is measured. By dividing the difference between the measured weight and the previously measured weight of the suction nozzle by the measured charge amount, the charge amount per unit weight of the toner can be obtained.

Japanese Patent No. 3567463 (FIG. 5)

  In the charge amount measuring device described in Patent Document 1, it is necessary to remove the lid of the insulating container in order to measure the weight of the suction nozzle. There is no specific description in Patent Document 1 regarding the structure for attaching the lid to the insulating container. If the lid is firmly fixed to the insulating container with a plurality of screws or the like, the operation for putting the suction nozzle in and out of the insulating container becomes very complicated. In the next measurement, it is necessary to disassemble the suction nozzle and clean the inside of the suction nozzle to which the toner has adhered, and further complicated work such as replacement of the filter in the suction nozzle requires a long preparation for the measurement work. There was a problem such as.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a powder charge measuring device that does not require cleaning of attached powder and simplifies the preparation work for the next measurement.

Means for Solving the Problems and Effects of the Invention

  The powder charge measuring device of the present invention includes a housing and a filter cartridge that is disposed in the housing and contains a filter that captures powder sucked from the outside of the housing. A powder charge amount measuring device for measuring the charge amount of powder trapped in the housing, wherein the casing is composed of first and second housing members for housing the filter cartridge, and the first housing The member has an outer first cover made of a conductive material, and an inner first case made of a conductive material having a suction port that is housed in the outer first cover and is electrically insulated from the outer first cover, The second housing member includes an outer second cover made of a conductive material that can be fitted into the outer first cover, and a conductive material housed in the outer second cover and electrically insulated from the outer second cover. Kara An inner second case, and both the first and second housing members are fitted with both covers, whereby the end face of the inner first case and the end face of the inner second case in the fitting direction. There is provided a lock mechanism for engaging the two housing members with each other while maintaining the state where the two are in pressure contact with each other.

  According to this, when both the covers are fitted, the locking mechanism works, and the two housing members incorporating the filter cartridge can be engaged with each other. Thus, the operation of inserting and removing the filter cartridge into and from the housing is simplified by the lock mechanism that engages the two housing members with each other. In addition, when the housing members are engaged with each other, the electrical contact between the outer first and second covers and the electrical contact between the inner first case and the inner second case are firmly maintained. Therefore, the amount of charge in the closed space of the inner first and second cases can be accurately measured, and the closed spaces of the inner first and second cases can be measured by the outer first and second covers that are in electrical contact. When measuring the amount of charges in the inside, the influence of the external electric field can be effectively eliminated.

  The powder charge measuring device of the present invention includes a housing and a filter cartridge that is disposed in the housing and stores a filter that captures powder sucked from the outside of the housing, A powder charge amount measuring device for measuring a charge amount of powder in a filter cartridge, wherein the housing includes first and second housing members for housing the filter cartridge, and the first housing member Is an inner first cover formed with a first outer cover made of a conductive material, a first holder made of an insulating material, and a nozzle made of a conductive material and disposed between the outer first cover. The second housing member is made of a conductive material and is made of an outer second cover that can be fitted to the outer first cover, a second holder made of an insulating material, and a conductive material. Kisotogawa and a second inner casing forming a cup holder which is arranged at a position sandwiching the second holder between the second cover. Then, by fitting both covers to the first and second housing members, an end face of the inner first case in which the nozzle portion is formed in the fitting direction and an inner second in which the cup holder is formed. There is provided a lock mechanism for engaging the two housing members with each other while maintaining a state in which the end surface of the case is in pressure contact.

  According to this, the locking mechanism works by fitting both covers, the two housing members containing the filter cartridge can be engaged with each other, and by releasing the locking mechanism, both housing members can be engaged. The engagement can be easily released. Thus, the operation of the lock mechanism for engaging the two housing members with each other simplifies the operation of inserting and removing the filter cartridge into and from the housing. In addition, when the two housing members are engaged with each other, electrical contact between the outer first and second covers and the inner second case in which the end surface of the inner first case in which the nozzle portion is formed and the cup holder are formed. The electrical contact with the end face of this is kept strong. Therefore, the amount of charge in the inner first and second cases can be accurately measured, and the outer first and second covers can measure the amount of charge in the inner first and second cases. The effect can be effectively eliminated.

  In the present invention, the locking mechanism is a cover that is one of the outer first cover and the second cover in the fitting direction, and protrudes from an inner peripheral surface that overlaps the other cover of the cover, The other cover has an annular protrusion that protrudes from the outer peripheral surface overlapping the one cover and has a notch corresponding to the protrusion. The protrusion is engaged with the annular protrusion by rotating the one housing member less than one turn in the circumferential direction after fitting the covers so that the protrusion passes through the notch. It is preferable to do. Thereby, a lock mechanism becomes a simpler structure.

  Moreover, in this invention, the inner side 1st case which formed the said nozzle part is along the said fitting direction from the said 1st holder between the said 1st holder and the inner side 1st case where the said nozzle part was formed. It is preferable that a first urging member for urging the inner first case formed with the nozzle portion so as to be separated is provided. Thereby, the press-contact force of the end surface of the inner second case forming the cup holder against the end surface of the inner first case in which the nozzle portion is formed when the two housing members are engaged with each other is increased. Therefore, the electrical contact state between the two can be more reliably maintained.

  In the present invention, the filter cartridge may be separated from the inner first case in which the nozzle portion is formed along the fitting direction between the inner first case in which the nozzle portion is formed and the filter cartridge. It is preferable that a second urging member for urging the filter cartridge is provided. Thereby, even if there is some variation in the size of the filter cartridge with respect to the fitting direction, it is possible to absorb the variation in the size by the second urging member.

  Further, in the present invention, a plurality of protrusions are formed on the outer peripheral surface of the filter cartridge so as to be spaced apart from each other along the circumferential direction, and the plurality of protrusions connect the filter cartridge to the nozzle portion. When it is inserted into the inner first case formed with the tip, it is preferable that the tip engages with the inner first case formed with the nozzle portion. Accordingly, when the lock mechanism is released and the filter cartridge is removed from the housing, the filter cartridge is unlikely to fall out of the first housing member. Therefore, the powder is less likely to spill from the filter cartridge.

  In the present invention, the upstream end of the inner first case in which the nozzle portion is formed and the upstream end of the filter cartridge are disposed at substantially the same position along the suction direction for sucking powder. Is preferred. Thereby, all of the powder sucked into the inner first and second cases can be collected in the filter cartridge.

  Further, in the present invention, the filter cartridge includes a long portion extending along a suction direction for sucking powder, and a diameter-expanded portion having a diameter larger than that of the long portion and accommodating the filter. It is preferable that the outer peripheral side surface of the enlarged diameter portion is chamfered. This makes it difficult for the filter cartridge removed from the housing to roll. Therefore, the powder is less likely to spill from the filter cartridge, and the weight measurement of the filter cartridge that captures the powder can be performed stably.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view when a first housing member and a second housing member of a powder charge amount measuring device such as a toner according to an embodiment of the present invention are separated. FIG. 2 is an exploded perspective view of the powder charge measuring device shown in FIG. FIG. 3 is a cross-sectional view of a powder charge measuring device according to an embodiment of the present invention.

  As shown in FIG. 1, the powder charge amount measuring device 1 includes a housing 1 a and a filter cartridge 4 housed in the housing 1 a, and the outer shape is formed in a substantially cylindrical shape. The housing 1a includes a first housing member 2 and a second housing member 3, and is configured to be separable. The filter cartridge 4 is disposed between the housing members 2 and 3. The powder charge measuring device 1 is connected to a connecting member 70 for connecting a piping member connected to a suction pump (not shown) to the powder charge measuring device 1. For this reason, when the suction pump is driven, the powder charge amount measuring device 1 supplies the toner in a direction parallel to the axial direction from the left to the right in FIG. 3 (suction direction A). Suction.

  As shown in FIGS. 2 and 3, the first housing member 2 includes a cylindrical outer first cover 21 made of aluminum alloy, a cylindrical first holder 22 made of polycarbonate resin, and an outer side made of stainless steel. An inner first case 23 having an inner first case 23 formed with a cylindrical nozzle portion disposed at a position sandwiching the first holder 22 between the first cover 21 and the outer first cover 21 and the nozzle portion. One case 23 is arranged in an electrically insulated state. The inner first case 23 on which the outer first cover 21 and the nozzle portion are formed may be made of a conductive material other than aluminum alloy and stainless steel. The first holder 22 may be made of an insulating material other than polycarbonate resin.

  At the upstream end of the outer first cover 21 in the suction direction A, an annular flange 31 having a hole 31a through which a part of the inner first case 23 having the first holder 22 and the nozzle portion can be inserted is formed. At the downstream end in the suction direction A of the outer first cover 21, an annular protrusion 33 is formed which is formed by forming a groove 32 extending in the circumferential direction in the vicinity of the downstream end. Two cutouts 34 a and 34 b are formed in the annular protrusion 33. The notch 34a is formed at a position rotated 180 ° from the notch 34b. That is, the two notches 34 a and 34 b are arranged symmetrically with respect to the central axis of the outer first cover 21. As shown in FIG. 3, when the outer first cover 21 and the outer second cover 51 of the second housing member 3 are fitted to each other, the annular protrusion 33 has a first outer side in the fitting direction. The cover 21 protrudes from the outer peripheral surface overlapping the outer second cover 51.

  As shown in FIGS. 2 and 3, the first holder 22 includes a cylindrical tip portion 22a protruding outside from the hole 31a, and a cylindrical main body portion 22b whose most part is covered by the outer first cover 21. And an annular flange 22c that connects the tip 22a and the main body 22b. As shown in FIG. 3, the first holder 22 is fixed to the outer first cover 21 in a state where the annular flanges 31 and 22 c are in close contact with each other by screwing screws from the outer side of the outer first cover 21. Yes.

  An annular protrusion 36 protruding in the radial direction of the main body 22b is formed at the downstream end of the main body 22b in the suction direction A. The outer diameter of the annular protrusion 36 is substantially the same as the outer diameter of the annular protrusion 33. The annular protrusion 36 is formed with two notches 37a and 37b having the same shape and the same size as the two notches 34a and 34b. These notches 37a and 37b are arranged such that when the first holder 22 is fixed to the outer first cover 21, the notches 37a are just opposite to the notches 34a, and the notches 37b are just opposite to the notches 34b. And two large notches 38a and 38b are formed.

  The annular protrusion 36 is provided with two press-fit plungers 39a and 39b having resin balls urged outward in the radial direction of the main body portion 22b. The press-fit plunger 39a is disposed at a position rotated by 180 ° from the press-fit plunger 39b. That is, the two press-fit plungers 39a and 39b are arranged symmetrically with respect to the central axis of the main body portion 22b. The press-fit plungers 39a and 39b are arranged at positions rotated by 90 ° from the notches 37a and 37b.

  As shown in FIGS. 2 and 3, the inner first case 23 formed with the nozzle portion has a long portion 23 a extending along the suction direction A and a larger inner diameter than the inner diameter of the downstream end of the long portion 23 a. It has a diameter-enlarged portion 23b and a cylindrical collar 45 disposed in the enlarged-diameter portion 23b. The long portion 23a is formed stepwise along the suction direction A and the tip portion 41a that protrudes outside from the first holder 22 when the inner first case 23 in which the nozzle portion is formed is attached to the first holder 22. It has a connecting portion 41b that is enlarged in diameter and connects the distal end portion 41a and the enlarged diameter portion 23b. The inner first case 23 in which the nozzle portion is formed passes through the first inner case 23 in which the nozzle portion is formed in the first holder 22, and then a C-type retaining ring in the vicinity of the upstream end of the connecting portion 41 b in the suction direction A. By being provided with 42, it attaches so that it may not drop from the 1st holder 22. Moreover, although the short tube 99 which consists of an insulating material and has flexibility is engage | inserted by the front-end | tip part 41a, it does not need to be provided in particular.

  The diameter-expanded portion 23b is expanded in steps along the suction direction A. A tapered surface 45 a that is inclined with respect to the suction direction A is formed on the inner peripheral surface of the collar 45. The collar 45 is fixed to the enlarged diameter portion 23b with screws in a state of being in close contact with an annular flange 43 formed at the upstream end of the enlarged diameter portion 23b in the suction direction A.

  An urging member 47 is disposed in the connecting portion 41b. The urging member 47 is disposed between the stepped portion 48 of the connecting portion 41b and the collar 45, and moves the filter cartridge 4 inserted into the first inner case 23 having the nozzle portion in the suction direction A (that is, The filter cartridge 4 is urged in a direction away from the inner first case 23 in which the nozzle portion is formed. The urging member 47 includes a coil spring 47a and a pedestal 47b disposed between the coil spring 47a and the collar 45. For example, the urging member 47 may be configured by replacing the coil spring 47a with an elastic member such as rubber. The base 47b may be omitted.

  A biasing member 49 is disposed in the main body 22 b of the first holder 22. The biasing member 49 is disposed between the annular flange 22c and the enlarged diameter portion 23b, and biases the inner first case 23 in which the nozzle portion inserted into the first holder 22 is formed in the suction direction A. . In addition, since the C-type retaining ring 42 is provided in the inner first case 23 in which the nozzle portion is formed, the inner first case 23 in which the nozzle portion is formed from the first holder 22 does not fall off with respect to the suction direction A. The first holder 22 is slidably supported. The urging member 49 is composed of a coil spring, but may be composed of an elastic member such as rubber, for example.

  2 and 3, the second housing member 3 includes a cylindrical outer second cover 51 made of aluminum alloy, a second holder 52 made of polycarbonate resin, and an outer second cover made of stainless steel. The outer second cover 51 is sandwiched between the second inner case 53 formed of a polycarbonate resin and the inner second case 53 formed with a cylindrical cup holder disposed between the second holder 52 and the second holder 52. The outer second cover 51 and the inner second case 53 having the cup holder having the joint holder 54 disposed at the position are disposed in an electrically insulated state. The inner second case 53 in which the outer second cover 51 and the cup holder are formed may be made of a conductive material other than aluminum alloy and stainless steel. The second holder 52 and the joint holder 54 may be made of an insulating material other than polycarbonate resin.

  An annular flange 61 having a hole 61a through which a part of the second holder 52 can be inserted is formed at the downstream end of the outer second cover 51 in the suction direction A. The annular flange 61 is formed with a hole 61 b through which a coaxial cable (not shown) connected to a measurement electrometer (not shown) is passed, and the outer shield wire of the coaxial cable is connected to the outer second cover 51. The core wire is connected to the inner second case 53 in which the cup holder is formed.

  Two protrusion forming members 66 and 67 constituting two protrusions 51 a and 51 b protruding from the inner peripheral surface of the outer second cover 51 are fixed to the upstream end in the suction direction A of the outer second cover 51. . Specifically, two notches 68 and 69 are formed at the upstream end of the outer second cover 51. These notches 68 and 69 are arranged point-symmetrically around the central axis of the outer second cover 51. Then, the projection forming members 66 and 67 are fitted into the notches 68 and 69 so that the tip portions (projections 51a and 51b) protrude from the inner peripheral surface of the outer second cover 51, and the outer second cover 51 is screwed. It is fixed to. The shape of the part which protruded from the internal peripheral surface of the outer side 2nd cover 51 of the protrusion formation parts 66 and 67 is a shape corresponding to the notch parts 38a and 38b. Therefore, after the two outer first and second covers 21 and 51 are fitted together, the first housing member 2 is rotated by 90 ° along the circumferential direction, so that the protrusions are projected in the fitting direction parallel to the suction direction A. 51a and 51b and the annular protrusion 33 engage. Thus, the protrusions 51a and 51b and the annular protrusion 33 constitute a lock mechanism that locks the fitting of the housing members 2 and 3.

  As shown in FIG. 2, the second holder 52 has a substantially disc shape, and a surface of the inner second case 53 formed with a cup holder is formed on a surface facing the inner second case 53 formed with the cup holder. A recess 63 into which the downstream end in the suction direction A is fitted is formed. A hole 64 is formed at the center of the bottom surface of the recess 63. As shown in FIG. 3, an annular protrusion 52a that includes the hole 64 and is inserted into the hole 61a is formed on the surface of the second holder 52 opposite to the surface on which the recess 63 is formed. The second holder 52 is formed with a hole 52b that faces the hole 61b and has the same diameter as the hole 61b when fixed to the outer second cover 51. The core wire of the coaxial cable connected to the inner second case 53 in which the cup holder is formed and the insulating member covering the core wire are also passed through the hole 52b.

  As shown in FIG. 3, the inner second case 53 in which the cup holder is formed includes a tapered surface 53a inclined with respect to the suction direction A, a straight surface 53b extending along the suction direction A, and a tapered surface 53a and a straight surface. It has an inner peripheral surface composed of a curved surface 53c that connects 53b. Further, an annular protrusion 65 projecting in the radial direction is formed on the outer periphery of the end portion of the inner second case 53 on which the cup holder is formed on the side opposite to the second holder 52. The annular protrusion 65 has the same outer diameter as the largest outer diameter of the enlarged diameter portion 23b of the inner first case 23 in which the nozzle portion is formed. The inner second case 53 in which the cup holder is formed is screwed in from the outer side of the second holder 52 so that the downstream end in the suction direction A of the inner second case 53 in which the cup holder is formed is fitted in the recess 63. In this state, the second holder 52 is fixed.

  As shown in FIG. 3, the joint holder 54 includes an inner cylinder 71 that is fitted between the hole 61 a of the annular flange 61 and the annular protrusion 52 a of the second holder 52, and an outer cylinder 72 that is disposed outside the inner cylinder 71. And an annular flange 73 that connects the inner and outer cylinders 71, 72. On the inner peripheral surface of the inner cylinder 71, a female screw is formed from the vicinity of the center to the downstream end in the suction direction A, and the connecting member 70 is screwed into this female screw portion. An annular protrusion 52 a of the second holder 52 is fitted into the upstream end portion of the inner cylinder 71. An annular groove is formed on the outer peripheral surface of the annular protrusion 52a, and an O-ring is disposed in the annular groove. Thereby, the sealing performance between the inner cylinder 71 and the holder 52 is improved. The joint holder 54 is screwed into the second holder 52 from the outside of the joint holder 54, so that the annular flange 61 is sandwiched between the joint holder 54 and the second holder 52. The three members 51, the second holder 52 and the joint holder 54 are fixed.

  Next, the filter cartridge 4 will be described below. FIG. 4 is a perspective view of the filter cartridge shown in FIG. FIG. 5 is a cross-sectional view of the filter cartridge shown in FIG.

  As shown in FIGS. 4 and 5, the filter cartridge 4 includes two housings 81 and 82 that are made of an insulating material (for example, polypropylene resin) and can be fitted to each other, and a filter 83 that is housed in both the housings 81 and 82. It consists of and. The filter cartridge 4 includes a cylindrical elongated portion 4a extending along the suction direction A, a cylindrical enlarged portion 4b having a diameter larger than the inner diameter of the downstream end of the elongated portion 4a, and a long length. It has a cylindrical short part 4c shorter than the part 4a. The filter 83 is formed with a plurality of filter holes having a hole diameter such that the powder sucked into the filter cartridge 4 does not pass through the filter 83. As shown in FIG. 4, the outer peripheral side surface farthest from the center of the enlarged diameter portion 4b is chamfered. Thereby, even if the filter cartridge 4 removed from the housing 1a is placed on a flat surface so that the outer peripheral side surface thereof is in contact, the filter cartridge 4 is difficult to roll. For this reason, it is difficult for the toner to spill out of the filter cartridge 4, and the weight of the filter cartridge that captures the powder can be stably measured.

  The housing 81 is formed with an elongated portion 4a and an upstream half 85 that constitutes the upstream half of the enlarged diameter portion 4b. The long part 4a connects the tip part 86 having an outer diameter slightly smaller than the inner diameter of the tip part 41a, the tip part 86 and the upstream half part 85, and has an outer diameter slightly smaller than the smallest inner diameter of the joint part 41b. It has the joint part 87 which has.

  The distal end portion 86 has substantially the same length as the distal end portion 41a in the suction direction A, and the upstream end of the distal end portion 86 when the filter cartridge 4 is inserted into the first inner case 23 having the nozzle portion. And the upstream end of the tip portion 41a are arranged at substantially the same position. As a result, the powder sucked into the powder charge measuring device 1 does not adhere to the inner peripheral surface of the tip portion 41a, and most of the powder enters the filter cartridge 4. Therefore, it is possible to measure the weight of all the powders whose charge amount has been measured by measuring the weight of the filter cartridge 4. The connecting portion 87 has substantially the same length as the connecting portion 41b in the suction direction A. Three contact portions 88 and three protrusions 89 that extend in the suction direction A and protrude from the outer peripheral surface are formed on the outer peripheral surface of the connecting portion 87 and in the downstream end in the suction direction A. The abutting portions 88 and the protrusions 89 are arranged apart from each other along the circumferential direction, and are alternately arranged.

  The three contact portions 88 have a prismatic shape extending in the suction direction A, and the height from the outer peripheral surface of the connecting portion 87 is lower than the protrusion 89. Specifically, when the filter cartridge 4 is inserted into the inner first case 23 having the nozzle portion, the contact portion 88 passes through the collar 45 without contacting the inner peripheral surface of the collar 45 and contacts the pedestal 47b. The filter cartridge 4 is urged in the suction direction A by the urging member 47. By urging the filter cartridge 4 in the suction direction A in this way, the downstream end of the filter cartridge 4 can be pressed against the side surface of the second holder 52 containing the hole 64, so that the filter cartridge 4 and the cup holder are The sealing property between the formed inner second case 53 is also improved, and the powder can be reliably sucked and collected in the filter cartridge 4, and the inner first case 23 and the filter are formed between both the tip portions 41 a and 86. The powder is not accidentally sucked into the gap of the cartridge 4.

  The three protrusions 89 have a triangular prism shape extending in the suction direction A, and the sharp tips of the protrusions 89 are arranged at positions farthest from the outer peripheral surface of the connecting portion 87. Further, the protrusion 89 has such a height that the tip is brought into contact with the inner peripheral surface of the collar 45 and is crushed when the filter cartridge 4 is inserted into the inner first case 23 having the nozzle portion. . As a result, when removing the filter cartridge 4 from the housing 1a, the collar 45 and the projection 89 are engaged with each other, so that the filter cartridge 4 is unlikely to come off from the first housing member 2. Therefore, the powder is less likely to spill from the filter cartridge 4. Further, the upstream end surface of the protrusion 89 in the suction direction is inclined. Therefore, when the filter cartridge 4 is inserted into the inner first case 23 having the nozzle portion, the tip of the protrusion 89 is easily crushed.

  As shown in FIGS. 4A and 5, four ribs 91 are formed in the upstream half 85. The rib 91 extends from the vicinity of the inlet of the upstream half 85 to the vicinity of the outer peripheral end of the upstream half 85 along the inclined surface 85a. These ribs 91 are disposed at positions 90 degrees apart from each other with the central axis of the upstream half 85 as a center, and come into contact with the upstream surface when the filter 83 is stored in the filter cartridge 4.

  The housing 82 is formed with a short portion 4c and a downstream half 92 that constitutes the downstream half of the enlarged diameter portion 4b. The short portion 4c has an outer diameter slightly smaller than the smallest inner diameter (the inner diameter of the straight surface 53b portion) of the inner second case 53 that forms the cup holder. An annular protrusion 95 is formed at the downstream end of the short portion 4c. The outer diameter of the annular protrusion 95 is substantially the same as the smallest inner diameter of the inner second case 53 forming the cup holder.

  As shown in FIGS. 4B and 5, two ribs 93 that are orthogonal to each other and extend to the vicinity of the outer peripheral end of the downstream half 92 along the inclined surface 92 a are formed in the downstream half 92. Yes. These ribs 93 also come into contact with the downstream surface of the filter 83 when the filter 83 is stored in the filter cartridge 4, and sandwich the filter 83 with the rib 91. By providing the rib 93 in contact with the downstream surface of the filter 83 in this manner, the filter 83 is less likely to be deformed when the powder is sucked into the filter cartridge 4. Therefore, the filter 83 is less likely to be damaged, and the powder can be reliably captured by the filter 83. In addition, a notch 93 a is formed at the downstream end of each rib 93. The rib 93 extends from the vicinity of the outlet of the downstream half 92 to the vicinity of the outer peripheral end of the downstream half 92 along the inclined surface 92a.

  Subsequently, an operation until obtaining a charge amount per unit weight of the powder sucked by using the powder charge measuring device 1 will be described. FIG. 6 is an explanatory diagram when the filter cartridge is assembled to the first and second housing members.

  First, the weight of the filter cartridge 4 is measured. Then, as shown in FIG. 6, the filter cartridge 4 is disposed between the separated first and second housing members 2 and 3, and the long portion 4a of the filter cartridge 4 is formed on the inner side where the nozzle portion is formed. Insert into the long part 23 a of one case 23. At this time, the contact portion 88 contacts the pedestal 47 b, the tip of the projection 89 comes into contact with the inner peripheral surface of the collar 45 and is crushed, and the projection 89 and the collar 45 are engaged.

  Next, when the covers 21 and 51 are fitted, the positions of the covers 21 and 51 are adjusted so that the projections 51a and 51b can pass through the notches 38a and 38b. And the 1st and 2nd housing members 2 and 3 are moved to the direction which mutually approaches, and covers 21 and 51 are fitted. Before the covers 21 and 51 are fitted to each other, as shown in FIG. 6, the downstream end in the suction direction A of the inner first case 23 in which the nozzle portion is formed is moved by the biasing force of the biasing member 49 to the first holder 22. It protrudes in the suction direction A from the downstream end. However, by fitting the covers 21 and 51 together, as shown in FIG. 3, the downstream end face of the inner first case 23 in which the nozzle portion is formed and the annular protrusion 65 of the inner second case 53 in which the cup holder is formed. The inner first case 23 in contact with the upstream end surface and forming the nozzle portion is pushed into the first holder 22. At this time, since the pressing force of the upstream end surface of the annular protrusion 65 against the downstream end surface of the inner first case 23 in which the nozzle portion is formed by the urging force of the urging member 49 is increased, the inner first case 23 in which the nozzle portion is formed The electrical contact state with the inner second case 53 in which the cup holder is formed is further ensured. Furthermore, when the outer first and second covers 21 and 51 are fitted to each other and the protrusions 51a and 51b and the annular protrusion 33 are engaged with each other, The pressing force of the inner second case 53 forming the cup holder against the downstream end surface of the inner first case 23 in which the nozzle portion is formed is reduced, but by providing the urging member 49, between the covers 21, 51 The rattling is absorbed, and a decrease in pressure contact force between the inner first case 23 in which the nozzle portion is formed and the inner second case 53 in which the cup holder is formed is suppressed.

  Further, when the covers 21 and 51 are fitted together, the urging force of the urging member 47 acts on the filter cartridge 4, so that the downstream end surface of the filter cartridge 4 and the side surface of the second holder 52 including the hole 64 are included. The pressure contact force increases. Therefore, the sealing performance between the filter cartridge 4 and the inner second case 53 in which the cup holder is formed is improved, and the powder can be reliably sucked and collected in the filter cartridge 4. The powder is not accidentally sucked into the gap of the filter cartridge 4.

  Next, after the outer first and second covers 21 and 51 are fitted, the first housing member 2 is rotated by 90 °. Then, the resin balls of the press-fit plungers 39a and 39b are formed at positions facing the annular protrusions 33 on the inner peripheral surface of the outer second cover 51 and overlapping the protrusion forming members 66 and 67 along the suction direction A. Enter the two curved grooves. In addition, four curved grooves are formed in the outer second cover 51 and are arranged at positions separated from each other by 90 ° with the central axis of the outer second cover 51 as the center. As a result, the first housing member 2 becomes difficult to rotate with respect to the second housing member 3. That is, the first and second housing members 2 and 3 do not rotate easily unless a certain amount of rotational force is applied to the first and second housing members 2 and 3. Further, since the protrusions 51a and 51b are rotated by 90 ° from the position where they have passed through the notches 38a and 38b, the protrusions 51a and 51b and the annular protrusion 33 are engaged with each other in the fitting direction. The electrical contact between the covers 21 and 51 is maintained by the fitting at this time. Further, since the urging force of the urging member 49 also acts in the direction in which both the covers 21 and 51 are separated (the direction parallel to the fitting direction), the engagement force between the projections 51a and 51b and the annular projection 33 increases and the electrical force is increased. The contact state is more reliable. From this viewpoint, the urging member 49 also constitutes a part of the lock mechanism. In this way, the housing 1a is configured by locking the fitting of the two housing members 2 and 3.

  Next, a suction pump (not shown) is driven so as to generate a suction force from the distal end portion 86 of the filter cartridge 4 toward the filter 83, and the powder is sucked into the filter cartridge 4 through the tube 99. The sucked powder is captured by the filter 83. At this time, most of the powder adheres to the filter 83, but some powder also adheres to the inner surfaces of the tip end portion 86, the joint portion 87 and the upstream half portion 85. Then, the suction pump is stopped.

Next, the total charge amount of the powder in the filter cartridge 4 is measured. On the outer surface of the filter cartridge 4 formed of an insulator, an equal amount of charge is induced by dielectric polarization according to the amount of charge of the powder collected in the filter cartridge 4, and the filter cartridge 4 In accordance with the amount of electric charge induced by dielectric polarization on the outer surface, it is composed of a conductor container containing the filter cartridge 4, that is, an inner second case 23 having a nozzle portion and an inner second case 53 having a cup holder. An electric charge equivalent to the amount of powder collected in the filter cartridge 4 is generated in the conductive container by electrostatic induction, and the electric potential due to the charge is measured by an electrometer and collected in the filter cartridge 4. The value of the total charge amount of the obtained powder can be obtained.
In this regard, in the conventional Faraday cage, the capturing means for capturing the charged toner or the like is formed of a conductor container, and the electric charge is measured by measuring the potential of the conductor container. Conventionally, in such a device, bringing an insulator into the conductor container also brings a charged object, and at the time of sucking toner, frictional charging is caused between the sucked toner and the insulator. Although it was thought that this would lead to measurement errors, there was no such effect when actually confirmed. New knowledge was obtained that the measurement was not affected. In the above example, the filter cartridge 4 is made of an insulating material. However, the filter cartridge 4 may be made of a conductive material such as metal. Note that the total charge amount Q of the powder is a charge amount of a conductor container constituted by the inner second case 23 in which the nozzle portions before and after sucking the powder are formed and the inner second case 53 in which the cup holder is formed. And obtained from the difference.

  Subsequently, the charge amount per unit weight of the powder in the filter cartridge 4 is obtained. In this case, the filter cartridge 4 is taken out from the housing 1a and the weight of the filter cartridge 4 containing the sucked powder is measured. The method for taking out the filter cartridge 4 from the housing 1a is performed in the reverse order of the above. That is, the first housing member 2 is rotated by 90 °, and both housing members 2 and 3 are moved away from each other. Then, the capsule 4 supported by the inner first case 23 in which the nozzle portion is formed by the engagement between the collar 45 and the protrusion 89 is removed from the inner first case 23 in which the nozzle portion is formed, and the filter cartridge 4 is removed from the weight measuring device. For example, it is measured with an electronic balance. Then, when the total charge amount Q of the powder is divided by the difference between the measured weight and the weight of the filter cartridge 4 measured in advance before the filter cartridge 4 is attached to the housing 1a, the powder The amount of charge per unit weight of the body can be determined.

  As described above, according to the present embodiment, both housing members to which the lock mechanism is attached the capsule 4 simply by rotating the first housing member 2 by 90 ° in the circumferential direction after fitting both the covers 21 and 51. 2, 3 can be engaged with each other. Since the lock mechanism for engaging the two housing members 2 and 3 with each other has a simple configuration, the work of inserting and removing the filter cartridge 4 into and from the housing 1a is simplified. Further, at the time of the next measurement, it is only necessary to replace the filter cartridge 4 with a new one, and it is not necessary to disassemble and clean the suction nozzle portion or the like as in the prior art, and the workability of the measurement is improved.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. For example, in this embodiment, the locking mechanism is composed of the protrusions 51 a and 51 b and the annular protrusion 33, but a male thread portion is formed on the outer peripheral surface of the cover 21, and a female screw portion is formed on the inner peripheral surface of the cover 51. The housing member may be engaged with each other by rotating any one of the housing members by less than one rotation in the circumferential direction and screwing the male screw portion into the female screw portion. Further, the protrusions 51 a and 51 b may be formed on the first housing member 2, and the annular protrusion 33 may be formed on the second housing member 3. That is, the protrusions 51a and 51b and the annular protrusion 33 may be formed on the housing members 2 and 3 opposite to the present embodiment.

  Further, the lock mechanism is not limited to the one described above, and any mechanism can be used as long as it can reliably and easily assemble and separate the first housing member 2 and the second housing member 3. For example, a hook-type locking mechanism or coupler type that engages with the groove 32 so that the two housings 2 and 3 are not disengaged simply by fitting the first housing member 2 to the second housing member 3. The locking mechanism may be used. Furthermore, a plunger-type locking mechanism that locks the housings 2 and 3 so that the fitting between the housings 2 and 3 is not released only by the pre-fit plungers 39a and 39b may be used.

  Further, the urging members 47 and 49 may not be provided. Further, the plurality of protrusions 89 may not be formed on the outer peripheral surface of the filter cartridge 4. Further, with respect to the suction direction A, the upstream end of the inner first case 23 in which the nozzle portion is formed may not substantially coincide with the upstream end of the filter cartridge 4. The outer peripheral side surface of the filter cartridge 4 may not be chamfered. Further, the rib 93 may not be formed on the housing 82.

It is a perspective view when the 1st housing member and 2nd housing member of the powder electric charge measuring device by one Embodiment of this invention are isolate | separated. It is a disassembled perspective view of the powder charge amount measuring device shown in FIG. It is sectional drawing of the powder charge amount measuring device by one Embodiment of this invention. FIG. 3 is a perspective view of the filter cartridge shown in FIG. 2. FIG. 3 is a cross-sectional view of the filter cartridge shown in FIG. 2. It is explanatory drawing when a filter cartridge is assembled | attached to the 1st and 2nd housing member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Powder electric charge measuring device 1a Case 2 1st housing member 3 2nd housing member 4 Filter cartridge 4a Long part 4b Diameter expansion part 21 Outer 1st cover 22 1st holder 23 Inner 1st which formed the nozzle part 1 case 33 annular projection 34a, 34b notch 47 urging member (second urging member)
49 Biasing member (first biasing member)
51 Outer second cover 51a, 51b Protrusion 52 Second holder 53 Inner second case with cup holder 83 Filter 89 Protrusion 93 Rib

Claims (8)

A housing, and a filter cartridge that is disposed in the housing and contains a filter that captures powder sucked from outside the housing, the charge amount of the powder captured in the filter cartridge being A powder charge measuring device to measure,
The housing is composed of first and second housing members that house the filter cartridge,
The first housing member includes an outer first cover made of a conductive material, and an inner first case made of a conductive material having a suction port housed in the outer first cover and electrically insulated from the outer first cover. And
The second housing member includes an outer second cover made of a conductive material that can be fitted into the outer first cover, and a conductive material housed in the outer second cover and electrically insulated from the outer second cover. An inner second case made of
By fitting both covers to the first and second housing members, the end surface of the inner first case and the end surface of the inner second case are kept in pressure contact with respect to the fitting direction. In addition, a powder charge measuring device is provided, which is provided with a lock mechanism for engaging both housing members with each other. A powder that includes a housing and a filter cartridge that is disposed in the housing and contains a filter that captures powder sucked from the outside of the housing; A body charge measuring device,
The housing is composed of first and second housing members that house the filter cartridge,
The first housing member is an outer first cover made of a conductive material, a first holder made of an insulating material, and a nozzle made of a conductive material and disposed at a position sandwiching the first holder between the outer first cover. An inner first case formed with a portion,
The second housing member is made of an electrically conductive material and can be fitted to the outer first cover, the second holder is made of an insulating material, and the outer second cover is made of an electrically conductive material. 2 having an inner second case formed with a cup holder disposed at a position sandwiching the holder,
By fitting both covers to the first and second housing members, the end surface of the inner first case in which the nozzle portion is formed in the fitting direction and the inner second case in which the cup holder is formed. A powder charge measuring device characterized in that a lock mechanism is provided for engaging the two housing members with each other while maintaining a state in which the end surface is in pressure contact. The locking mechanism is a cover that is one of the outer first cover and the second cover in the fitting direction and protrudes from an inner peripheral surface that overlaps the other cover of the cover; An annular protrusion that protrudes from the outer peripheral surface overlapping the one cover and has a notch corresponding to the protrusion;
The protrusion engages with the annular protrusion by rotating the one housing member less than one turn in the circumferential direction after fitting both the covers so that the protrusion passes through the notch. The powder charge measuring device according to claim 1 or 2.   Between the first holder and the inner first case in which the nozzle portion is formed, the nozzle portion so that the inner first case in which the nozzle portion is formed is separated from the first holder along the fitting direction. The powder charge measuring device according to claim 2 or 3, wherein a first urging member is provided to urge the inner first case formed with the shape.   The filter cartridge is attached between the inner first case in which the nozzle portion is formed and the filter cartridge so that the filter cartridge is separated from the inner first case in which the nozzle portion is formed along the fitting direction. 5. The powder charge measuring device according to claim 2, wherein a second urging member is provided. A plurality of protrusions are formed on the outer peripheral surface of the filter cartridge so as to be spaced apart from each other along the circumferential direction.
The plurality of protrusions, when the filter cartridge is inserted into an inner first case in which the nozzle portion is formed, engages with the inner first case in which the nozzle portion is formed. Item 6. The powder charge measuring device according to any one of Items 2 to 5.   The upstream end of the inner first case in which the nozzle portion is formed and the upstream end of the filter cartridge are arranged at substantially the same position along a suction direction for sucking powder. The powder charge measuring device according to any one of 2 to 6. The filter cartridge has a long portion extending along a suction direction for sucking powder, and a diameter-expanded portion that has a diameter larger than that of the long portion and accommodates the filter,
The powder charge measuring device according to any one of claims 1 to 7, wherein an outer peripheral side surface of the enlarged diameter portion is chamfered.

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