JPH0452763Y2 - - Google Patents

Description

[Detailed explanation of the idea]

(Industrial Application Field) The present invention relates to a developer storage container that stores powder developer for replenishment, and discharges and replenishes it to a developer container of a developing device after being transported and stored. (Prior Art) In order to discharge powder from the inside of a commonly used container, it has been required that the inside of the container be made smooth and that the accuracy be quite high. This type of conventional container stores a large amount of developer and is called a developer container (also called a hopper).
Some containers have openings at their longitudinal ends to prevent scattering during supply. Since it is difficult to store 100% of the developer in this container, a small amount of space remains inside the container. This space allows the developer to move within the container, but at the same time, the developer aggregates and becomes uneven during storage and transportation. In order to prevent this, it is required to shake the container several times before supplying the developer, but this tends to cause blockage near the opening, so the inner surface of the container is made smoother for better drainage. I also didn't have high expectations. Furthermore, in order to keep the cost of packaging materials low, it is required for this type of container to fill as much developer as possible with respect to the volume of the container and to make the opening as small as possible. However, the general idea is that making the opening smaller will increase the amount remaining in the container, so the opening has been made to be a certain size. In addition, with conventional developer storage containers, even if you shake the container before replenishing it, it will not be transported or
It was not possible to sufficiently loosen the developer that had hardened during storage. Therefore, in the past, there was a drawback that the developer could not be replenished smoothly and the replenishment operation required a long time. However, more important issues than these remain unresolved. That is, the risk of damage to the container containing the developer during transportation has not been resolved. Particularly under low temperature conditions around -5° C., if the container falls, it will be destroyed and the developer contained therein will be scattered and wasted. Therefore, the developer storage container is required to be protected from damage before being sold. To solve this problem, if you create a container with a wall thickness of 3 to 5 mm or more, it will not only cause uneven strength, resulting in a relatively weak container, but also increase the volume occupied by the container itself, making it difficult to hold enough developer. There is an inconvenience that the amount cannot be stored. (Purpose of the invention) The present invention was made by focusing on the problem of container damage among the above-mentioned problems. The purpose of this invention is to provide a drug storage container. (Summary of the invention) The invention stores replenishing developer in a long synthetic resin container body, and allows the developer container of the developing device to be accessed from an opening provided at one end in the longitudinal direction of the container body. In the developer storage container for discharging and replenishing the developer, the container body is blow-molded and has an octagonal cross section in a direction perpendicular to the longitudinal direction, with short sides and long sides alternating. The bottom surface of the other end in the longitudinal direction and the octagonal peripheral surface are continuous by a curved surface having a radius of curvature, and this radius of curvature is larger on the short side than on the long side, and the container body The inner surface is provided with a plurality of protrusions in the longitudinal direction in a direction intersecting with the longitudinal direction, and the ratio of the area (a) cm ² of the developer discharge opening and the volume (W ₂ ) cc of the container is ( W ₂ /a) is 50 or more, and the volume of the container (W ₂ ) and the volume of the developer contained in the container (W ₁ ) is the value obtained by dividing the weight of the developer by the true specific gravity of the developer. ) is characterized in that the ratio W ₂ /W ₁ is 3.5 or more. According to this invention, even under low temperature conditions of -15℃, 90cm
It withstands a head drop test and reliably preserves stored developer without wasting it. Further, according to the present invention, sufficient durability can be achieved without increasing the wall thickness of the container, so that the amount of developer stored can be increased. The present invention will be described below with reference to examples. (Example) In the example described below, several preferable conditions were set for each purpose.
The present invention includes any combination of one or more of these. A preferred embodiment of the present invention does not simply consider the shape of the developer storage container or the shape of the opening, but also focuses on the container volume of the developer storage container, that is, the volume of the space that stores the developer and is sealed. , a developer storage container that can efficiently discharge the developer from inside the container without requiring a complicated structure. Further, in a preferred embodiment of the present invention, a relatively large amount of developer can be accommodated, the amount of residual developer can be significantly reduced, and stable discharge can be achieved. In the example described below, the area of the developer discharge opening of the container (a) cm ² and the volume of the container (W ₂ ) cc
The developer storage container has a ratio (W ₂ /a) of 50 or more, and the ratio of the volume (W ₂ ) cc of the container to the volume (W ₁ ) cc formed by the developer accommodated in the container. _W2 /
The developer storage container is characterized in that W ₁ is 3.5 or more. This embodiment also has a configuration that focuses on the ratio between the amount of developer stored in the container and the closed space for storing the developer in the container, which improves the movement of the powder developer within the container. Gas is used for dispersing and discharging the powder developer, and discharging can be done quickly and reliably. This embodiment provides extremely excellent practical effects. Volume (W ₂ ) of the developer storage container in this example
cc is the volume of the closed space in which the developer is accommodated, and to give a specific example of measurement, a method such as placing water in the closed space and calculating the volume by dividing the amount of water contained therein by the specific gravity can be applied. Further, the volume (W ₁ )cc of the developer in the present invention is defined as the weight of the developer stored in the developer storage container divided by the true specific gravity (average value). When this developer is a two-component developer, the volume of the developer is the sum of the volume obtained by dividing the weight of the carrier particles by the true specific gravity of the carrier particles and the volume obtained by dividing the weight of the toner particles by the true specific gravity of the toner particles. shall be. Further explanation of the present invention and more preferred configurations of the present invention will be understood from the following description. First, as the developer container A, inner surface protrusions 1 to 7 which increase the effect in terms of powder discharge performance and agitation performance.
A container having the following structure will be explained with reference to FIG. Container A having this protrusion is a synthetic resin powder storage container having openings 21 and 31 for accommodating powder and discharging the powder, and the powder storage container has a longitudinal end B that Members 12 and 13 having an opening and closing the opening of the opening
and a plurality of minute protrusions 1 to 7, which are provided in a direction intersecting with the longitudinal direction and protrude inside the container and become an obstacle when the powder moves in the longitudinal direction, so as to be independent from each other in the longitudinal direction. This is a powder storage container characterized by: FIG. 1 is a side view of a container embodiment applied to the present invention, in which the container A has protrusions 1 to 7 which are spaced apart from each other in the longitudinal direction and protrude inward over the entire circumference.
It is a cylindrical resin bottle having an opening 16 at the upper end, which is the end in the longitudinal direction, and the opening 16 is usually closed with a cap (not shown). The bottle is
A mixed material of polypropylene and polyethylene.
After putting the liquid material into the mold, air was introduced into the container and blow molding was performed. Protrusions 1 to 7 are curved protrusions (radius of curvature 8.2±0.5) with a width _t1 of 10 mm and a maximum height of 5 mm with respect to the inner diameter of the resin bottle of 100 mm. Protrusion (2,
3), (4, 5), and (6, 7) form pairs of each other, the interval t ₂ between the pairs is the same as the width t ₁ , and the interval t ₃ of each pair is greater than the width t ₂ ( In this example, it is 3 times),
These are arranged at regular intervals as shown. This protrusion is formed by a container recess formed around the entire periphery of container A. The container recesses (in this example, the radius of curvature γ ₁ is 7.2 mm) are formed by protrusions 1 to 1, respectively.
7 (radius of curvature γ), and the boundary between the container circumferential surface and the recess is formed so that the mold has an apex for forming an edge and does not form a curved surface but a substantial edge. I am doing it. This edge 8 is
This has the purpose and effect of being able to maintain the shape of the container A at the central boundary and preventing large deformation even if the container 8 receives input during feeding. If this boundary has a radius of curvature of 5
In the case of 1 mm, the container is greatly deformed, creating an internal pressure that causes the seal 23 to peel off from the container, and the deformation during supply causes problems such as scattering of the developer. Moreover, this edge makes it possible to make the wall thickness t of the central region of the container uniform, and in this example, the container is formed to have a thickness of 1 mm. Note that the thickness of the recessed portion is 3 mm. The container opening side end B is the side distance D (container A
Since it is approximately octagonal, the parallel planes are spaced at intervals of 10) and are decreased toward the cap 15 shown in Fig. 3.
When the decreasing angle is θ, in this example, θ=10 degrees. This angle θ is preferably in the range of greater than 0 and less than 20 degrees as a discharge condition, and in practice, it is suitable that the angle θ is greater than 0 and less than 15 degrees to be effective for various developers. found. This decreasing angle not only reliably guides and discharges the developer inside the container main body in the longitudinal direction, but also produces resin for forming the ring 20 as a reinforcing part and the stopper part of the cap 15, which will be described later, thereby reinforcing the entire container. can. It has been experimentally found that the angle θ is in the range of 10°±1, providing stable discharge of toner particles of 5 μm to 30 μm in powder size. Since the end B area does not have a recess separated by the edge 8, it is made thicker than the center thickness t _p (1.5 mm in this example) for the purpose of supplementing strength.
And so. Since the opening area of this end B is reduced, good evacuation performance can be obtained with a configuration in which the protrusions 1 to 7 are not provided at the end B as in this example. Now, the part of the developer storage container that is most likely to be damaged is the bottom of the end C facing the opening on the opposite side of the opening. In this embodiment, the cross-sectional shape of the central region of the container and the bottom portion thereof, which intersect with each other with respect to the longitudinal direction of the container, that is, the developer discharge direction, is approximately octagonal (FIG. 2). As seen in Figure 2, the bottom of the container is an octagon with long sides 10 and short sides 9 arranged next to each other, with the corners of a square cut off, and the longitudinal direction from the bottom to the center area of the container Regarding, the short side 9 has a radius of curvature R of 20 mm, and the long side 10 has a radius of curvature R ₁ of 10 mm.
It is set to mm. In other words, the short sides correspond to the corners of the quadrilateral. By eliminating the corners and changing the radius of curvature in this way, we can significantly reduce the chance of breakage when using these corners as corners, and even under low-temperature conditions, developer scattering, transport failure, and waste due to container breakage can be avoided. It can be prevented. In this case, when the curvature R of the short side 9 is made the same as R ₁ , the thickness of the bottom of the container is uneven, the molded product is weak in strength, and a 90 cm drop test at -5°C results in a lot of damage. A crack had formed that caused developer to leak. When this was placed in the presentation box 22 and subjected to the same drop test, the temperature at -5°C was the limit at which cracking could barely be suppressed, and it was unusable at -10°C and -15°C. In contrast, in this example,
By changing the radius of curvature, the thickness of the bottom part could be made uniform, and no cracks or developer scattering occurred even in the same drop test at -15°C. When this was subjected to a drop test at -20°C, only a few cracks were observed. In addition, in this example, the wall thickness of the bottom region C
We were able to mold t _p to a uniform 1.5 mm. As described above, the container of this example, which does not crack or scatter even under practical conditions of -15°C, has improved limits and is good in terms of transportability and developer storage. In this way, having adjacent parts with different radii of curvature (in this example, they are provided alternately, but one side may be different with two sides in between) forms a uniform distribution of the resin material. It has been found that this increases the reliability of the container. Further, in the case of having a large side and a small side, it is preferable to make the radius of curvature of the small side larger because this further ensures uniform thickness distribution. Further, in this embodiment, for a developer storage container that is transported and sold in a presentation case 22 having a rectangular cross section,
Provides a larger developer storage capacity than a cylindrical container,
It also has the effect of reducing container costs. Furthermore, in this example, the recess and the convex portion 7 formed corresponding thereto are placed at a distance L from the bottom (60 mm in this example) with respect to the end region including the bottom described above.
At least one (or two or more may be provided) is provided within the area. This is preferable because it further increases the strength of the bottom and prevents deformation caused by human effort. Experimentally, 80 mm is a good distance L, and this example has a configuration in which there is one protrusion 7 and one recess within 60 mm. This configuration interacts with the radius of curvature of the bottom to achieve increased strength of the container. As described above, in addition to the configuration of the radius of curvature, this embodiment preferably has an additional configuration for improving the strength of the entire container, and also prevents wastage of the developer in the container and improves drainage. It is also in good condition. As mentioned above, the protrusion is preferably composed of at least a plurality of protrusions, which ensures that the developer (using toner particles with an average diameter of 8 μm) is dispersed before reaching the opening. This is one of the preferred embodiments of the present invention because the developer can be supplied smoothly. In FIG. 3, 11 is the outer frame of the cap 15;
12 is a rotatable shutter, 13 is a shutter fixed to 11, and the shutters 12 and 13 are used by being fitted into the outer frame 11 so that the openings 21 and 31 do not overlap. When in use, this cap is set in the developer hopper of the developing device and the shutters 12 are rotated to align the openings of the shutters 12 and 13, so that the developer is discharged. FIG. 3 shows a cap 15 which forms an opening for the developer to flow out which is smaller than the cylindrical inner diameter of the container A, and has a shutter that can be opened and closed, and the opening area indicated by the arrow is 40% of the cross-sectional area of the container. Container A shown in FIG. 1 was filled with an electrophotographic developer up to about 75% of the container volume, and the cap shown in FIG. 3 was placed and vibrated with a vibrator for 10 minutes in the same manner as described above. Fourth
As shown in the figure, the developer container A was set in a developer hopper 16 having a developing device (not shown since it may be a known one) below, the shutter was opened, and the developer was discharged. In the case of this container, the discharge was completed in about 20 seconds. Further, the amount of developer remaining in the container after being discharged was 10 to 15 g in the conventional container, whereas it was significantly reduced to 1 to 5 g in the container shown in FIG. Note that 17 indicates a relatively large mesh provided at the powder input portion of the developer container hopper 16;
The toner from container A is dispersed and passed through. In the above embodiment, the protrusions are provided over the entire inner circumferential surface of the container, and the protrusions are perpendicular to the outflow direction of the powder, so the effect is quite good. Even if it does not cover all the particles, the presence of a plurality of separate particles makes it possible to flow out the powder much better than before. The protrusions on the inner surface of the container that act as obstacles to the powder and have the effect of acting on the powder may have any shape as defined in the present invention. Particularly preferably, the shape has a large component in the direction perpendicular to the direction in which the container is shaken. In the above example, only an electrophotographic developer was used as the powder, but the projections can be applied to all kinds of powder. Especially average particle size 3
The effect is remarkable for powders of ~40 μm that tend to aggregate. If the amount of protrusions on the inner surface of the container is too large or too small, the effect will be reduced.
More preferably, it is about 20 to 40%. If the height of the protrusion on the inner surface of the container is too low, it will have little effect, and if it is too high, it may become a major hindrance rather than an obstacle when discharging the powder. 0.5~ of distance between inner walls
The optimal amount is about 20%, preferably about 2 to 10%. However, the required height of the protrusions may vary depending on the shape of the powder. For example, average particle size 40μm
For powders that are difficult to agglomerate, a protrusion of 2 to 3 mm is sufficient in a container with an inner diameter of 100 mm, but an average particle size of 10 μm is sufficient.
In the case of the following easily agglomerated powders, the inner diameter is 100
mm container requires a projection with a height of 5 mm or more.
In this sense, protrusions with a height of 1 mm or more are suitable for powder average particle diameters of 3 to 40 μm. The arrangement of the protrusions may be regular or irregular, but preferably, as shown in Figure 1, the protrusions are not equidistant and are close to each other (referred to as a set of protrusions in close proximity). It is better to have a place where the protrusions are spaced apart by a smooth surface (this is called a set where the sets are arranged with a larger interval than the distance between the protrusions within the set). In general, the larger the number of protrusions is, the greater the effect will be if the area of the protrusions is constant; however, if the number is too large, the effect will be less because the space between the protrusions will be smaller. Approximately 3 to 20 pieces in the normal longitudinal direction is considered appropriate. As explained above, the simple structure of separately providing multiple convex shapes on the inner surface of a powder container allows the powder that has aggregated inside the container to be dispersed and loosened when the powder container is shaken. This has the effect of making the process more efficient and making it easier to discharge the powder. Furthermore, the presence of the protrusions can increase the strength of the powder storage container. The following will explain what is effective for each of the above-mentioned containers, and which can further enhance the effect of the projections, especially for those having projections. First, with the configuration shown in Figure 1, the discharge port area a (cm ² ) when the gap shown in Figure 3 is attached to the opening 16 is 15.8 (cm ² ).
Let the container volume W ₂ be 3800 (cc) in terms of water capacity, so,
W ₂ /a≈240.5, and the ratio of W ₁ to a was 50 or more.
A developer was stored in this container, and an experiment was conducted in which the container was placed perpendicularly to the replenishment port of the developing device as shown in FIG. This is because when the ratio of the container opening area to the container volume is small, the problem of supply failure when storing a large amount of developer could not be solved by simply widening the opening area. This is an experiment.
In other words, the present inventors conducted this experiment because they noticed that there was some kind of relationship between the container volume, the opening area, and the stored developer volume. The experiment involved varying the weight of toner (true specific gravity: 1.45) as the developer, and observing how the developer was discharged depending on the number of times the developer storage container was shaken. The results are summarized in Table 1.

[Table] As can be seen from Table 1, it was found that there was a very significant difference depending on the ratio of the developer amount to the container volume. Good developer discharge is possible when the container volume (W ₂ )/stored developer volume (W ₁ ) is
It was also found that it was 3.5 or higher. Next, when we conducted experiments using toners with different specific gravity, we found that the minimum number of times differed by one or two times, but the same tendency was observed. , W ₂ /W ₁ is 3.5 or more, which is the critical point where an extremely significant change occurs. Also, if the container does not have a protrusion, the container volume is 2.
In the following cases, good discharge results were obtained with the above-mentioned limit value W ₂ /W ₁ ≧3.5. This result is thought to be due to the fact that even if the number of shakes is small, air, which is a gas in the container, coexists between the powder particles and improves discharge. In addition, a container having a protrusion inside was a preferable condition for satisfying the ratio of W ₂ /W ₁ even for a large-capacity container with a container volume exceeding 2. For containers that exceed the container volume 2 and have no internal protrusions, the limit value of W ₂ /W ₁ becomes large, and if it exceeds 3.8, which is less than 10%, then 2
For those with protrusions, extremely good discharge was achieved with W ₂ /W ₁ of 3.5 or higher. The container thus has the advantage of containing more developer within the container volume and allowing good drainage. Next, container A has a container volume W ₂ of 1600 (cc), W ₂ /a
An experiment was conducted using a modified version of 113.9. At this time, use the cap shown in Figure 5, and set the opening area to 15.8
(cm ² ), and the ratio was set to 50 or more. This ratio of 50 or more means that the opening is small compared to the volume of the container, but the present invention has an even stricter condition in which the opening of the container has an aperture shape that is smaller than the cross-sectional area perpendicular to the developer movement direction of the container. It is extremely effective for

[Table] In this case as well, there is a significant difference when W ₂ /W ₁ is around 3.5, confirming that W ₂ /W ₁ ≧3.5 is an important condition that is not influenced only by the volume of the container. It was done. The shape of the container is not limited to the cap type, and similar results were obtained with only a seal. The contents of the container (air and developer) are mixed well by shaking the container, increasing the fluidity of the toner, and loosening the toner, allowing for smooth discharge even if the opening is small compared to the volume of the container. became possible. In addition, a container that satisfies the above-mentioned protrusion or volume ratio relationship (or a container with strength and durability, as in the present invention, prevents inconveniences during supply and improves evacuation) can be used to easily unravel copies. This makes it possible to smoothly discharge areas where there is a safety grate at the machine entrance where even large-diameter containers are blocked and cannot be discharged. This method is effective for any powder, especially powders that tend to clump or powders like toner.
The effect is particularly remarkable for powders whose main particle size is 20μ or less. The larger the content of the container, the greater the effect of the radius of curvature of the present invention. Also, various shapes of containers can be used, and the example shown above is one example, but it is better to use a bottle with many irregularities.
Smooth discharge is possible even if W ₂ /W ₁ is a small value. (Effects) According to the present invention, it is possible to prevent waste during developer transport and damage to the container itself, and to achieve good developer supply regardless of the shape of the container. Further, according to the present invention, the developer can be smoothly discharged from the developer storage container.

[Brief explanation of the drawing]

FIG. 1 is a side view of a cylindrical powder container in which the present invention is implemented, FIG. 2 is a bottom view of the container shown in FIG.
FIG. 4 is a perspective view showing how the developer is supplied to the developer hopper using the container shown in FIG. 1 and the cap shown in FIG. 3. 1 to 7 are protrusions, 11 is the outer frame of the cap 15, 1
2 is a rotatable shutter, 13 is a fixed shutter,
A is a developer storage container, 15 is a cap used for container A, 16 is a developer hopper lid, 17 is a developer replenishment port, and R and _R1 are curvature radii.

Claims (1)

[Claim for Utility Model Registration] A replenishing developer is stored in a long synthetic resin container body, and the developer container of the developing device is accessed through an opening provided at one longitudinal end of the container body. In the developer storage container for discharging and replenishing the developer, the container body is blow molded,
The cross section perpendicular to the longitudinal direction has an octagonal shape with alternating short sides and long sides, and the bottom surface of the other end in the longitudinal direction and the octagonal peripheral surface are continuous by a curved surface with a radius of curvature. The radius of curvature of the short side portion is larger than that of the long side portion, and the inner surface of the container main body is provided with a plurality of convex portions in the longitudinal direction in a direction intersecting the longitudinal direction, for discharging the developer. The ratio (W ₂ /a) of the opening area (a) cm ² to the volume (W ₂ ) cc of the container is 50 or more, and the volume (W ₂ ) of the container and the developer contained in the container are 50 or more. The ratio of W ₂ /W ₁ to the volume formed by (W ₁ , which is the value obtained by dividing the weight of the developer by the true specific gravity of the developer) is 3.5.
A developer storage container characterized by the above.