JPH02111980A - Developer supplying container - Google Patents

Abstract

PURPOSE:To improve sealability by compressing specific low-expansion polyurethane to a specific ratio and using the same as a sealing member. CONSTITUTION:The sealing member 2 is applied with compressive stress at 30% compression rate between a bearing surface (a) and agitating shaft 3 of a container body 1. The bearing surface (a) of the container body 1 is embossed to increase the friction resistance to the sealing member 2. The sealing member 2 is thus compressed and fixed. A material having <=5% compression set, 5 to 75 hardness (specified in JIS K 6301) and <=0.8 coefft. of friction MU is prefer able for the sealing member 2. The member is preferably so constituted as to be compressed by >=30%. The more specific materials include low-expansion polyurethane, silicone rubber sponge, etc. The size of the cell is preferably <=300mum and the sp. gr. 0.2 to 0.5g/cm<3> in case of the low-expansion polyure thane. The high sealability is maintained in this way even with a developer which is fine powder and has good flowability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a developer supply container for supplying developer to a developing device such as an electrostatic copying machine or a printer.

[Prior Art] Conventionally, some developer supply containers have a stirring device for preventing agglomeration of the powder developer contained in the container body and for assisting conveyance to a developing device.

Many stirring devices of this type utilize mechanical motion, but because the developer supply container is generally disposable, they require expensive members and structures. Therefore,
The sealing member is compressed between the container body and the stirring shaft, and the current (
It has been common to have a configuration that prevents the leakage of the agent and at the same time rotates the stirring shaft by moving the sealing member and the stirring shaft.

An example of this will be further explained based on the schematic diagram shown in FIG. Bar 5
stirred by The driving force at this time is guided from a driving source outside the developer container main body 1 via the stirring shaft 3 connected to the stirring rod 5.

Therefore, the stirring shaft 3 is brought into contact with the sealing surface of the developer container main body 1 via the sealing member 2 by a stopper bottle 4 that suppresses displacement in the thrust direction. This sealing member 2 has a structure that allows it to rotate freely guided by the rotation of the stirring shaft 3, and its sealing performance is not so high.

[Problems to be Solved by the Invention] However, the developer used in electrophotographic copying machines and blinkers is usually a fine powder with a volume average particle size of 20 μm or less, and moreover, it does not contain materials such as silica that impart fluidity. Since it is added, a considerably high degree of sealing performance is required to keep it hermetically sealed inside the container. Furthermore, when the particle size of the developer becomes even finer, or when the amount of developer filled in the container is increased in order to reduce costs, the sealing conditions become even more severe.

In conventional methods, to seal the developer in a container,
It is necessary to apply considerable pressure to the seal member to ensure seal surface pressure, but the frictional resistance with the stirring shaft increases and the stirring torque increases.However, as the stirring torque increases, the drive to the stirring shaft increases. The load on the gears (not shown) that relays the image becomes heavy (and in the worst case, the gear teeth jump, causing problems such as pitch unevenness, image unevenness, and image white lines.For this reason, It was necessary to increase the strength of the gears and the rotational power of the drive motor, which tended to increase costs.

On the other hand, in order to reduce the stirring torque, the sealing member is
To solve this problem, if the pressure is reduced, the developer will leak during use, and in the worst case, the leaked developer will reach the relay gear, causing abnormal noise and an increase in stirring torque. Although various sealing members have been used for this purpose, none have been able to fully satisfy the sealing performance and stability of stirring torque.

[Means and effects for solving the problems] An object of the present invention is to solve the above-mentioned problems and provide a structure or material with high sealing performance.

That is, according to the present invention, the sealing member is made of a material having appropriate hardness and smoothness with low compression set and low repulsive force during compression, so that the sealing part can be sealed and the frictional resistance can be reduced. By compressing the developer into a container, it is possible to provide a developer supply container with good sealing properties and stable stirring torque. In addition, in order to make the present invention more effective, it is necessary that the sealing member and the stirring bearing of the container body be arranged on a surface (second
In order to improve the sealing performance between the stirring shaft and the stirring shaft, it is preferable that the sealing member does not rotate together with the stirring shaft, and the stirring bearing is fixed to the surface.

In the configuration of the present invention, the stirring shaft and the inner diameter side of the sealing member slide, but the sealing member is compressed on one side of the shaft, and the action of tightening the stirring shaft works effectively (so that the sealing property is improved). is good.

This seal member has a compression set of 5% or less and a hardness of 5 to 7.
5 (JIS standard 6301), preferably a material with a friction coefficient μ = 0.8 or less, and 1 to compress 30% or more.
Specific materials that are preferably used include low foaming polyurethane, silicone rubber sponge, and the like. In the case of low-foaming polyurethane, the cell size is preferably 300 μm or less and the specific gravity is approximately 0.2 to 0.51<7 cm.Also, this sealant has an appropriate repulsive force when compressed, and the degree of compression is It is desirable that the degree of increase in the repulsive force that changes when the compression force is increased is gradual, and by using the material of the present invention, a significant increase in frictional resistance due to changes in the degree of compression can be prevented, and a highly stable Stirring torque can be obtained.

FIG. 5 shows the difference in the relationship between the repulsive force and the degree of compression between the conventional sealing material (wool felt) and the sealing material used in the present invention (low foaming polyurethane).

In addition, as a method of fixing the seal member to prevent co-rotation, the bearing of the container body may be embossed on the surface of the container body (section a in Figure 2) and the surface of the seal member facing the container (section shown in Figure 2), or double-sided tape or friction may be applied. There are two methods of fixing, such as attaching a member with a large coefficient to increase the frictional resistance, and fixing from the outer diameter side of the seal member, and these methods ensure the effects of the present invention. .

Hereinafter, the present invention will be explained in detail based on examples.

[Example] ! m Figures 1 and 2 show a first example in which the present invention is applied to a conventional configuration.
An example of this is shown. FIG. 1 is an enlarged cross-sectional view of the stirring unit in a sealed assembled state, in which 1 is the developer container body, 2 is a sealing member, 3 is a stirring shaft, 4 is a stopper bottle, and 5 is a stirring rod. Figure 2 shows an exploded sectional view of the stirring part in Figure 1. 6 In assembly, the stirring shaft is passed through the hole in the sealing member, the bearing is pushed into the part, the sealing member is compressed, and it protrudes into the inside of the container. Insert the stopper bottle into the hole on the stirring shaft and secure it.

In this example, the sealing member has a specific gravity of polyurethane foam of 0,
32, the thickness was 3.0 mm, and the bearing of the container body was compressed to 2.1 mm between the surface and the stirring shaft. That is, the structure is such that compressive stress is applied at a compression rate of 30%. Also,
The surface of the bearing of the container body (section a in FIG. 2) was textured to increase the frictional resistance with the sealing member, thereby compressing and fixing the sealing member.

According to this example, the developer (volume average particle diameter 12μ,
Even when 385 g of the developer was placed in the container body and continuously stirred for 24 hours, no leakage of developer from the stirring section or other abnormalities were observed. Further, the stirring torque was stable at 1500 to 1700 gf·cIR when the developer was contained in the container body.

The configuration of the stirring section and the material of the sealing member used were all the same as in Example 1.

In this example, as a method of fixing the sealing member, double-sided tape was pasted on the surface of the sealing member facing the container (part a in Fig. 2), and the stirring bearing of the container body was fixed to the surface (part a in Fig. 2). 0 In this example, the same test as in Example 1 was conducted, and the same effects were obtained.

Figure 4 is a perspective view showing a third embodiment of the present invention. The stirring bearing of the container body has the same configuration as Example 1 except that the shape of the surface and the sealing member was changed. In this example, the sealing member was fixed in a square shape as shown in Fig. 4. Even though the sealing member was press-fitted into the rectangular hole in the surface of the stirring bearing of the container body and fixed in Example 3, the same test as in Example 1 was conducted, and the same effect was obtained.

When we tested wool felt, which is commonly used as a sealing member for stirring parts, with the same configuration as in Example 1, we found that the stirring torque was quite large.In order to reduce the stirring torque, we increased the thickness of the felt by 3. Change from 0mm to 2.5mm,
When the compression ratio is increased from 30% to 16%, the initial stirring torque is approximately 1000 g 100 O, but as the stirring time becomes longer, developer leakage becomes more significant, and in the worst case, the drive to the stirring shaft may be relayed. It reached the gear part where the oil was being used, causing abnormal noise and an increase in stirring torque.

This is because a felt with a large compression set exhibits good sealing performance initially, but if it continues to be compressed for several days or even several hours, it loses its elasticity and its sealing performance deteriorates.

In addition, when we tried rubber sponge, olefin elastomer, and urethane elastomer as sealing members with the same configuration as in Example 1, we found that the stirring torque was large for all of them when compressed enough to ensure sealing performance. It is had.

In addition, in the examples described above, low foaming polyurethane is used in all cases, but the present invention is not limited to low foaming polyurethane. Similar effects can be obtained with other materials. Furthermore, the method of fixing the sealing member to the surface of the stirring bearing of the container body is not limited to this example, and the method of fixing the sealing member and the stirring bearing to the surface is equivalent as long as the method allows the sealing member and the stirring bearing to be fixed tightly to the surface and maintain sealing performance. The effect of this can be obtained.

[Effects of the Invention] As explained above, low foaming polyurethane is used as the sealing member for the stirring part of the developer supply container, and the sealing member is fixed so as not to rotate together with the stirring shaft.

The durability of the agitation section is improved compared to the previous model, so it maintains high sealing performance even with fine powder and fluid developer.
In addition, it is possible to obtain a stable and appropriate stirring torque, and it is also possible to increase the amount of developer filling and increase the development speed.

In addition, by stabilizing the stirring torque, there is no increase in the torque as in the conventional case, so it is possible to downsize the drive motor, change the material of the relay gear (no longer requires strength), and reduce the number of relay gears. The structure is simple, with relatively inexpensive low-foaming polyurethane as the sealing material, and the number of parts is small: stirring shaft, stopper bottle, and stirring rod.
It is also advantageous for cost reduction.

[Brief explanation of the drawing]

FIG. 1 is an enlarged cross-sectional view of the agitation unit according to the present invention in a sealed assembled state, FIG. 2 is an exploded cross-sectional view of the agitation unit according to the present invention, and FIG. 3 is a developing device having a developer stirring mechanism. FIG. 4 is an enlarged exploded perspective view of the stirring part of another example, and FIG. 5 is a cross-sectional view of the agent supply container. FIG. 5 shows the degree of compression and repulsive force of the sealing material used in the present invention and the conventional sealing material. It is a graph showing the relationship. 1-Developer container main body 2-Seal member 3151 stirring shaft 4-Stopper bottle l present/drop j
rIl milk drop each book Figure 1 5 - Stirring rod 6 - Developer 7 - Stirring blade a - Stirring bearing of the container body is surface b - Sealing member facing the container surface Canon Co., Ltd.

Claims (2)

[Claims] (1) A developer supply container having a developer stirring mechanism and a sealing material for the stirring shaft bearing part has a hardness of 5 to 75.
(According to JIS standard K6301), 30% low foam polyurethane with a compression set of 5% or less, a friction coefficient μ of 0.8 or less with respect to the sliding partner member, a cell size of 60 to 300 μm, and a specific gravity of 0.2 to 0.5. A developer supply container characterized by a sealing member which is used after being compressed. (2) The developer supply container according to claim 1, wherein in the developer supply container, a seal member is fixed to the container body so that the seal member does not rotate together with the stirring shaft.