JPH07181802A - Doctor gap adjusting mechanism - Google Patents

Abstract

PURPOSE:To provide a doctor gap adjusting mechanism for automatically and precisely adjusting the gap between a developing roller and a developing blade, at the time of manufacturing a developing device. CONSTITUTION:A temporarily positioning pin 1 supported so as to vertically slide by a supporting block 3 and a linear guide 4 and an adjusting pin 2 provided in a driving part 8 capable of being vertically movable in an adjusting direction (the direction of the arrow A) are concentrically positioned. The adjusting hole 6a of a doctor blade 6 is fitted to the temporarily positioning pin 1, to position (temporarily position) it. A driving part 8 is lowered to push the pin 1 into the supporting block 3 by the adjusting pin 2. After that, the driving part 8 is moved in the adjusting direction and the doctor blade 6 is moved via the adjusting pin 2, to adjust the gap between the developing roller 7 and the doctor blade 6, that is, a doctor gap to a prescribed size.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a doctor gap adjusting mechanism for adjusting a gap between a developing roller and a developing blade (doctor blade) in manufacturing a developing device using a two-component developer.

[0002]

2. Description of the Related Art Conventionally, a developing device using a two-component developer is well known as a developing device mounted on an image forming apparatus such as a copying machine, a printer or a facsimile. Typically,
Many two-component developers are composed of a toner and a carrier, and a developing device using the two-component developer is widely used in an image forming apparatus such as an electrophotographic system or an electrostatic recording system.

In a developing device using a two-component developer, toner and carrier are mixed and stirred inside the device and supplied to a developing roller by a supply member such as a stirring paddle. The developing roller is usually a magnet roller in which a magnet group is fixedly arranged inside a cylindrical sleeve formed of a non-magnetic material, and the toner is magnetized on the roller surface.
Then, the developer (toner) supplied to the developing roller by the stirring paddle is regulated to a constant amount by the developing blade (doctor blade).

The size of the gap between the developing roller and the doctor blade, that is, the doctor gap is an important characteristic value for forming (developing) an appropriate image.

Conventionally, at the time of manufacturing a developing device, this doctor gap has been manually set and inspected using a gap gauge.

[0006]

However, the accuracy of manual adjustment of the doctor gap is as low as ± 0.1 mm, and if accurate adjustment (setting) is not performed,
There is a problem that it adversely affects proper image formation (development).

The present invention solves the above-mentioned problem that the accuracy of the manual adjustment of the doctor gap at the time of manufacturing the developing device is low, which adversely affects the proper image formation (development), and the accuracy of the doctor gap is high. It is an object to provide a doctor gap adjusting mechanism that enables automatic adjustment.

[0008]

According to the present invention, there is provided a doctor gap adjusting mechanism for automatically adjusting a gap between a developing roller and a developing blade at the time of manufacturing a two-component developing device. The problem can be solved by including a position provisionally determining member for provisionally determining the position, and a movement adjusting unit for moving the developing blade provisionally positioned by the position provisional determining member to adjust the gap to a predetermined value.

Further, according to the present invention, in order to solve the above-mentioned problems, the temporary positioning member is a pin member which is inserted into a hole provided in the developing blade and is provided at a temporary positioning position and a retracting position. It is proposed that the movable pin is movable.

Further, according to the present invention, in order to solve the above-mentioned problems, the movement adjusting means has an adjusting pin that can be inserted into the hole of the developing blade, and the adjusting pin is coaxial with the movable pin at the start of adjustment. When the adjustment pin is inserted into the hole portion of the developing blade that is set to be located above and is temporarily inserted into the movable pin, the movable pin pressed by the adjustment pin is moved to the retracted position. It is proposed that the gap can be adjusted by moving.

[0011]

Operation: The developing blade positioned by the temporary position determining member (temporary positioning) is moved by a predetermined distance by the movement adjusting means to adjust the gap (doctor gap) between the developing blade and the developing roller to a predetermined value. To do.

Other functions will be apparent from the description of the embodiments below.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In order to accurately set the gap between the doctor blade and the developing roller, that is, the doctor gap, during the manufacture of the two-component developing device, it is necessary to move the doctor blade at a predetermined position by a predetermined distance. It is not possible to make adjustments. For that purpose, first of all, it is absolutely necessary to place the doctor blade accurately in a predetermined position.

Therefore, according to the present invention, the doctor blade can be accurately placed at a predetermined position (the position of the doctor blade can be accurately tentatively determined), and then the doctor blade can be moved by a predetermined distance to accurately set the doctor gap. A doctor gap adjusting mechanism is provided. That is, in FIG. 1, 7 is a developing roller and 6 is a doctor blade. At the time of manufacturing this developing device, the doctor blade 6 is held by a holding means (not shown) so as to be movable in the arrow A direction. A guide plate 10 of an automatic adjustment mechanism is located behind the doctor blade 6 (opposite to the developing roller 7). The adjustment drive unit 8 is located above the guide plate 10, and the adjustment pin 2 is attached and fixed to the flat plate 9 of the drive unit 8. Then, the drive unit 8 can be moved in the vertical direction by a vertical mechanism (not shown). In addition, a drive mechanism composed of a motor, a gear and the like (not shown) is housed in the drive unit 8 and can be moved in the doctor gap adjusting direction (direction of arrow A) by a guide rack (not shown). The drive unit 8 including the adjustment pin 2 is also provided on the opposite side in the longitudinal direction of the doctor blade 6, and the doctor gap is adjusted by a pair of left and right drive units 8 (in the longitudinal direction of the doctor blade 6). .

By the way, an adjusting hole 6a is provided at a position of a distance C from the end of the doctor blade 6 on the side opposite to the developing roller 7. Further, the adjusting pin 2 described above is normally stopped at a position where the distance from the center of the pin to the guide plate 10 is C. Therefore, when the doctor blade 6 is brought into contact with the guide plate 10, the adjustment hole 6 is provided directly below the adjustment pin 2.
a is coming.

When the doctor gap is adjusted by this automatic adjusting mechanism, the doctor blade 6 held by the holding means (not shown) so as to be movable in the adjusting direction is brought into contact with the guide plate 10. Then, as described above, the adjustment hole 6a provided in the doctor blade 6 is located directly below the adjustment pin 2. At this point, the adjustment drive unit 8 is lowered to insert the adjustment pin 2 into the adjustment hole 6a. afterwards,
The adjusting drive unit 8 is moved in the direction of arrow A toward the developing roller 7, and the gap between the doctor blade 6 and the developing roller 7, that is, the doctor gap is set to a predetermined value.
The operation of the drive unit 8 at the time of adjustment is controlled by a control unit such as a CPU (not shown) and can be adjusted with an accuracy of ± 0.05 mm.

Then, after fixing the doctor blade 6 set to a predetermined doctor gap, the drive unit 8 rises and the adjusting pin 2 is pulled out from the adjusting hole 6a of the doctor blade 6, and the adjusting work is completed.

Thus, according to the doctor gap adjusting mechanism of this embodiment, the doctor blade 6 and the developing roller 7 are
It is possible to set the gap between the two, that is, the doctor gap with high accuracy, and it is possible to manufacture a developing device that exhibits appropriate developing performance.

However, in this automatic adjustment mechanism, the doctor blade 6 must first be brought into contact with the guide plate 10 located on the rear side in the adjustment direction and then moved in the opposite direction to adjust the doctor gap. No, it takes time to adjust. Further, the doctor blade 6 is not fixed in the adjustment direction, and only comes into contact with the guide plate 10 when the adjustment pin 2 is inserted. Therefore, when an external force such as vibration is applied, It is conceivable that the doctor blade 6 temporarily positioned moves in the adjustment direction. Then, the adjustment pin 2 cannot be inserted into the adjustment hole 6a, and the doctor gap cannot be adjusted.
Further, when the doctor blade 6 largely moves in the adjustment direction, the developing roller 7 and the doctor blade 6 may come into contact with each other and damage each other. Further, in order to surely insert the adjustment pin 2 into the adjustment hole 6a, the distance between the guide plate 10 and the adjustment pin 2 and the position where the adjustment hole 6a of the doctor blade 6 is provided in the normal condition must be strictly controlled. I have to.

Therefore, as another embodiment of the present invention, a doctor gap adjusting mechanism improved from the above embodiment will be proposed below.

2 and 3, a provisional pin support block 3 (hereinafter referred to as a support block) is located in the vicinity of the developing roller 7 in the lateral direction. The support block 3 has a cylindrical hollow portion, and a linear guide 4 is embedded in the upper end portion thereof. The linear guide 4 also has a cylindrical hollow portion, but its diameter is smaller than the hollow portion of the support block 3. Then, the provisional setting pin 1 is fitted in the hollow portion of the linear guide 4 and can slide up and down, and is pushed up from below by the spring 5 inserted in the hollow portion of the support block 3. The diameter of the lower end of the provisional pin 1 is larger than that of the other parts so that it cannot be pulled out upward from the linear guide 4.

The drive unit 8 is located above the support block 3, and the adjustment pin 2 is mounted and fixed to the flat plate 9 of the drive unit 8. The adjusting pin 2 is usually coaxial with the provisional pin 1. The drive mechanism 8 can be moved in the vertical direction by a vertical mechanism (not shown). In addition, a drive mechanism including a motor, a gear, and the like (not shown) is housed in the drive unit 8,
It can be moved in the doctor gap adjustment direction (arrow A direction) by a guide rack (not shown).

In order to adjust the doctor gap,
First, the adjustment hole 6a of the doctor blade 6 is temporarily set in the pin 1
And is held by a holding means (not shown) so as not to move in the vertical direction. The doctor blade 6 held by the holding means is movable in the doctor gap adjusting direction, but cannot be moved in the adjusting direction when the provisional setting pin 1 is fitted in the adjusting hole 6a, and the doctor blade 6 is accurately positioned. Has been done.

In this state, when the automatic adjustment of the doctor gap is started, as shown in FIG. 4, the drive unit 8 descends (moves in the direction of arrow B), and the adjustment pin 2 becomes the provisional pin 1.
Press down. When the provisional pin 1 is pushed, the spring 5 in the support block 3 contracts, and the provisional pin 1 is pushed into the support block 3. At this time, since the adjustment pin 2 and the provisional pin 1 are located on the same axis, the adjustment pin 2 is surely inserted into the adjustment hole 6a, and the provisional pin 1 can be pushed into the support block 3. After that, the drive unit 8 moves in the adjustment direction (direction of arrow A) to adjust the gap between the developing roller 7 and the doctor blade 6, that is, the doctor gap to a predetermined size. The operation of the drive unit 8 at the time of adjustment is controlled by a control unit such as a CPU (not shown) and can be adjusted with an accuracy of ± 0.05 mm.

Then, after fixing the doctor blade 6 set to a predetermined doctor gap, the drive unit 8 rises and the adjusting pin 2 is pulled out from the adjusting hole 6a of the doctor blade 6, and the adjusting work is completed.

When the adjusting pin 2 is removed from the adjusting hole 6a, or when the adjusting pin 2 is moved in the adjusting direction and the pressing force of the provisional determining pin 1 is released, the provisional determining pin 1 acts on the spring 5. However, even if the provisional pin 1 contacts the doctor blade 6, it does not affect the adjustment work because the tension force of the spring 5 does not need to be so strong. Further, the support block 3 may be provided so as to be movable up and down, and when the provisional pin 1 is pushed into the support block 3 by the adjustment pin 2, the support block 3 may be retracted downward.

According to the doctor gap adjusting mechanism of the present embodiment, the doctor blade 6 which has been temporarily positioned can be immediately moved to the predetermined position, so that the adjustment does not take time. Further, since the provisional setting pin 1 is inserted into the adjustment hole 6a at the time of provisional positioning, the doctor blade 6 does not move even when there is vibration or the like, and the doctor blade 6 and the developing roller 7 come into contact with each other. Both sides will not hurt. Furthermore, since the provisional pin 1 and the adjustment pin 2 are positioned coaxially at the start of adjustment, the adjustment pin 2 is reliably inserted into the adjustment hole 6a. Furthermore, doctor blade 6
Since it is not necessary to strictly control the distance C in FIG. 1, the component manufacturing cost can be suppressed.

[0029]

As described above, according to the doctor gap adjusting mechanism of the present invention, the gap between the doctor blade and the developing roller, that is, the doctor gap can be set with high accuracy, so that the proper developing performance is exhibited. The developing device can be manufactured.

According to the structure of claim 2, since the movable pin (temporary setting pin) is inserted in the adjusting hole of the doctor blade, the doctor blade does not move due to vibration or the like, and the developing roller and the doctor blade are damaged. There is no. In addition, the cost of manufacturing doctor blade parts can be reduced.

According to the third aspect of the present invention, since the provisional setting pin and the adjustment pin are positioned coaxially at the start of adjustment, the adjustment pin is surely inserted into the adjustment hole.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a perspective view showing another embodiment of the present invention.

FIG. 3 is a side view (partially sectional view) of the embodiment shown in FIG.

4 is a side view (partially sectional view) showing a state during an adjusting operation in the embodiment shown in FIG.

[Explanation of symbols]

 1 Temporary pin 2 Adjusting pin 3 Support block 4 Linear guide 5 Spring 6 Doctor blade 6a Adjusting hole 7 Developing roller 8 Drive part 10 Guide plate

Claims (3)

[Claims] 1. A doctor gap adjusting mechanism for automatically adjusting a gap between a developing roller and a developing blade when a two-component developing device is manufactured, and a position provisionally determining member for temporarily determining the position of the developing blade, and the position. A doctor gap adjusting mechanism, comprising: a moving adjusting unit that moves the developing blade temporarily positioned by a temporary determining member to adjust the gap to a predetermined value. 2. The position provisionally determining member is a pin member that is inserted into a hole provided in the developing blade and is a movable pin that is movable between a provisionally determining position and a retracted position. The doctor gap adjusting mechanism according to claim 1. 3. The movement adjusting means has an adjustment pin that can be inserted into the hole of the developing blade, and the adjustment pin is set so as to be positioned coaxially with the movable pin at the start of adjustment. When the adjustment pin is inserted into the hole portion of the developing blade that is fitted and provisionally positioned, the movable pin pressed by the adjustment pin moves to the retracted position and the gap can be adjusted. The doctor gap adjusting mechanism according to claim 2, which is characterized.