JPH0436386B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cleaning device using a blade in a copying machine or the like.

In an electrostatic copying machine, after a toner image formed on a photoreceptor is transferred to a transfer paper, it is necessary to remove toner remaining on the photoreceptor. A cleaning device using a blade as a device for removing this residual toner is known.

By the way, in a cleaning device using this blade, the amount of pressure applied to the blade changes depending on the amount of penetration of the blade into the photoconductor, that is, the corresponding position of the tip of the blade with respect to the surface of the photoconductor, and it is possible to determine whether the cleaning state is good or not. is affected. For this reason, this type of cleaning device is configured to regulate the positional relationship between the blade and the photoconductor using a blade pressure adjustment mechanism so that the amount of penetration of the blade into the photoconductor is appropriate. . However, although this conventional cleaning device can regulate the position of the blade when it approaches and separates from the photoreceptor, it cannot adjust the change in the amount of bite caused by expansion and contraction of the blade itself.

That is, in this cleaning device, the length of the blade itself changes due to changes in the temperature of the environment, and as a result, the amount of bite of the blade may become inappropriate. Therefore, when setting the blade biting amount in this device, it is necessary to change the set value according to the environmental temperature at that time.

For example, the standard value of blade depth is 0.5±0.1mm.
In this case, when the temperature at the time of setting is 10℃, the blade depth is set to 0.4 to allow for expansion of the blade.
mm, and at 30℃, take into account the shrinkage.
It is conceivable to set it in advance to correspond to the temperature change of the blade, such as 0.6 mm. but,
In reality, this kind of temperature control is difficult, and
If the amount of expansion and contraction of the blade exceeds the allowable range of the appropriate biting amount, there is a drawback that optimum cleaning cannot be performed.

This invention was made in view of the above points,
The purpose is to provide a cleaning device that can always maintain a constant value by setting the blade biting amount to a predetermined standard value without considering an increase or decrease due to temperature changes.

The present invention will be explained below with reference to illustrated embodiments.

A cleaning device in a copying machine is arranged, for example, along the generatrix direction of the photoreceptor 1, as shown in FIG. In this cleaning device, when the photoreceptor 1 is rotated by operating the print button, the blade 2 is pressurized by a solenoid (not shown), and the blade 2 is brought into a cleaning state. Note that this blade 2 removes the residual toner on the photoconductor, and then
That is, after copying is completed, the solenoid is released and returns to the position indicated by the two-dot chain line in FIG.

The blade 2 is fixed to a support 3, and the support 3 is fixed to a blade rotation shaft 4 with a screw 5.

The blade rotation shaft 4 is rotatably supported on the side of the cleaning device casing 6, and the one end 4
An auxiliary lever 7 is fixed to a (see FIGS. 2 and 3). A stopper pin 8 is caulked to this auxiliary lever 7. A tip 10a of a stopper 10 fixed to the copying machine main body 9 extends into the rotation path of the stopper pin 8, and when the blade rotation shaft 4 is rotated by the solenoid mentioned above, this When the stopper pin 8 comes into contact with the tip 10a, the rotation of the rotation shaft 4 is stopped, and the blade tip 2a is positioned. Therefore, by changing the position of the tip 10a of the stopper 10, the amount d of the blade 2 biting into the photoreceptor 1 can be adjusted.

By the way, as mentioned earlier, the blade (made of rubber) used in conventional cleaning devices expands and contracts depending on the temperature, and experimental results show that the blade (made of rubber) expands and contracts by 0.11 mm/10 degrees.
It has a certain degree of expansion and contraction. Therefore, the above-mentioned conventional blade pressure (blade biting amount) adjustment mechanism has a drawback that it cannot cope with changes in biting amount due to expansion and contraction of the blade itself due to temperature changes.

In other words, the environmental temperature in which copying machines are used changes within a wide range of 0°C to 35°C in all four seasons, and the expansion and contraction of the blade at this temperature theoretically reaches 0.385 mm. In the above mechanism where the appropriate range of biting amount is narrow, this expansion and contraction of the blade is a fatal drawback.

In particular, at low temperatures, the amount of bite may drop below zero due to blade contraction.
Sometimes it becomes impossible to clean.

In the above-mentioned mechanism, if the setting value is increased in advance so that the blade biting amount does not decrease at low temperatures, the inability to clean can be resolved, but in this case, the blade biting amount when the blade is extended is Since the amount exceeds the appropriate value, there are drawbacks such as poor cleaning and failure to release the blade.

As described above, the appropriate range of the blade biting amount is extremely small, and therefore, even if the set value is simply changed by the above-mentioned adjustment mechanism, it is difficult to obtain a good cleaning effect throughout the seasons.
Further, expansion and contraction of the blade due to temperature changes cannot be avoided due to the material of the blade.

Therefore, as shown in FIGS. 5 and 6, for example, the appropriate location of the blade pressure adjustment mechanism (in the illustrated embodiment, the tip 10a of the stopper 10) is made of the same material as the blade or a material with a high coefficient of linear expansion similar to that of the blade. A pressure regulating member 11 consisting of the following is provided. Fifth
As shown in FIG. 6 and FIG.
The contact positional relationship between the stopper pin 8 and the stopper pin 8 changes according to changes in the environmental temperature. That is, when the temperature is high, the pressure regulating member 11 expands as shown in FIG. 5, and rotates the auxiliary lever 7 in the direction of arrow a via the stopper pin 8. As the auxiliary lever 7 rotates, the blade 2 rotates to the left in FIG.
a rotates in a direction away from the surface of the photoreceptor 1.

In this way, as the pressure regulating member 11 expands (proportional to temperature), the blade 2 separates from the photoreceptor 1, and the amount of bite d appears to decrease. However, since the blade 2 itself also expands to approximately the same extent in proportion to its temperature, the increase in the biting amount due to the expansion of the blade 2 is due to the decrease in the biting amount due to the expansion of the pressure regulating member 11. and are canceled out.

Therefore, according to the cleaning device provided with this pressure regulating member 11, even if a temperature change occurs, the amount of biting of the blade into the photoreceptor remains substantially constant. When the temperature is low, the pressure regulating member 11 contracts, the auxiliary lever 7 rotates in the direction of arrow b in FIG. Even though the amount of biting is increased, contrary to the above, the blade 2 itself is also reduced, so the biting amount remains approximately constant.

In addition, in the embodiment shown in FIGS. 5 and 6,
Although the pressure regulating member 11 is disposed at the tip of the stopper 10, for example, as shown in FIG.
1 around the stopper pin 8, the same effect as above can be obtained.

Further, each of the above-mentioned embodiments shows an example in which the pressure regulating member 11 is disposed at the abutting portion between the stopper 10 and the stopper pin 8. For example, as shown in FIG. A similar effect can be obtained by arranging the stopper 10 at the base of the pressure regulating member 10 and rotating the stopper 10 in accordance with the expansion and contraction of the pressure regulating member 11 due to temperature changes.

It goes without saying that when selecting the material of the pressure regulating member 11, it is determined by taking into account the amount of blade biting, the lever ratio of the regulating mechanism, the temperature, and the like. As described above, according to the present invention, the shortcomings of the conventional mechanism can be very effectively overcome by simply adding a pressure regulating member to the conventional blade pressure adjustment mechanism.

As described above, the cleaning device according to the present invention suppresses changes in the biting amount due to changes in blade temperature by arranging a pressure regulating member with a high coefficient of linear expansion at the appropriate position of the adjustment mechanism that regulates the position of the blade. Since it is possible to absorb the heat and keep it substantially constant, it is possible to prevent cleaning defects caused by changes in the amount of bite of the blade. Further, since the disadvantages of the conventional device can be solved using extremely simple components, the cost does not increase.

[Brief explanation of drawings]

Figure 1 is a schematic sectional view of the cleaning device, Figure 2 is a schematic sectional view of the cleaning device;
The figure is a schematic diagram of an adjustment mechanism for positioning the blade, Figure 3 is a partial plan view of the adjustment mechanism, Figure 4 is an explanatory diagram showing the amount of blade bite, and Figure 5 shows an embodiment of the invention. 6 is a plan view of the above embodiment, FIG. 7 is a partial side view showing another embodiment of the invention, and FIG. 8 is a partial side view showing still another embodiment of the invention. be. DESCRIPTION OF SYMBOLS 1...Photoreceptor, 2...Blade, 3...Support, 4...Blade rotating shaft, 7...Auxiliary lever,
8... Stopper pin, 10... Stopper pin, 1
1...Pressure adjustment member, d...Blade biting amount.

Claims (1)

[Claims] 1. In a cleaning device that uses a blade to remove residual toner on a photoconductor, a linear expansion material that is made of the same material as the blade or similar to that of the blade is installed at an appropriate location in the blade pressure adjustment mechanism that regulates the positional relationship between the blade and the photoconductor. A pressure regulating member made of a material with a constant coefficient is provided, and the expansion and contraction of this pressure regulating member as a result of temperature changes offsets the expansion and contraction of the blade itself due to temperature changes, thereby keeping the blade pressure approximately constant. A cleaning device with special features.