JPH0521083Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a toner replenishing device with improved toner replenishment in a developing device using a two-component developer.

[Conventional technology]

FIG. 6 shows a configuration diagram of the main mechanical parts of the electrophotographic copying machine. A photoreceptor drum 1 is located approximately in the center of the copying machine body, a scanning exposure optical system 2 is located above it, an automatic document feeder 3 is located above the body, a recording paper reversing conveyance device 4 is located at the bottom of the body, and a recording paper reversing conveyance device 4 is located on the right side of the body. A recording paper accommodating device 5 is arranged in each of the areas.

A toner replenishing device 7 connected to the developing device 6 near the photosensitive drum 1 drops the stored toner into the toner receiving port at the upper right of the developing device 6 through a replenishing port 7a at the bottom and into the developing device 6. Replenish toner.

The toner replenishing device 7 has a storage chamber (hopper) 7b which is long in the front-rear direction of the copying machine body in order to increase the amount of toner that can be accommodated. The toner is conveyed in one direction by force.

In the developing device 6, a stirring roller 6a mixes toner and carrier, and the uniformly mixed developer consisting of toner and carrier is carried on the circumferential surface of the developing sleeve 6b and forms a latent image on the photoreceptor drum 1. is developed and made into a toner image.

When copying is repeated, the toner in the developing device 6 is consumed, and therefore, unless an amount of toner commensurate with the consumption is replenished and the mixture ratio of toner and carrier is always kept constant, copies with proper density are not made. Therefore, the mixture ratio of toner and carrier in the developing device 6 is detected, and the toner is automatically dropped and replenished by the shutter means.

[Problem that the invention attempts to solve]

The toner T accommodated in the storage chamber 7b is easily solidified due to temperature and humidity, especially in the large storage chamber 7b.
A large amount of toner contained in the container b tends to be compressed by its own weight and solidify.

When it becomes bulky, the toner T close to the conveying screw 7c grows into an arch-like or bridge-like hard wall, and the inside becomes hollow, causing the storage chamber 7
Even though there is sufficient toner in the container b, the toner T does not fall even when the conveying screw 7c rotates, making it impossible to replenish the developing device 6 with toner. In order to prevent such a toner hollowing phenomenon, there is a method of rotating an agitation roller 7d in the storage chamber 7b to agitate the toner T and eliminate the bridging. When the toner T is filled, the toner T around the agitation roller 7d is compressed by the agitation roller 7d and solidified, creating a cavity similar to that described above.
d only idles in the cavity and does not send the toner T to the conveyance screw 7c, or does not eliminate the cavity generated around the conveyance screw 7c, causing problems in that the toner T is not dropped or replenished.

In order to solve the above problem, a vibrating member is provided on the top of the toner replenishing member near the toner replenishing port to prevent the toner from falling, and the vibrating member is oscillated as the toner replenishing member rotates. The applicant proposed the device in Utility Application No. 158058/1983.

However, the above-mentioned toner replenishing device is also insufficient to eliminate the phenomenon of toner cavitation in a large and deep storage chamber.

[Means for solving problems]

This invention prevents the toner from falling due to the toner hollowing phenomenon in the toner storage chamber of the toner replenishing device, thereby keeping the toner in a fluid state and ensuring proper toner replenishment to the developing device. The purpose is to provide a replenishment device.

The toner replenishing device of the present invention which achieves the above object is provided with a diaphragm for preventing the toner from falling close to the inclined inner wall surface of the replenishment box where toner is replenished, and a cam guide with good thermal conductivity is attached to the diaphragm. By providing a section and intermittently pressing the cam guide section by a cam means with good thermal conductivity which is rotationally driven by a drive source, the diaphragm is oscillated and the cam guide section and the cam means are pressed together. This feature is characterized in that it is configured to radiate heat generated due to friction at the parts.

〔Example〕

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

FIG. 1 is a front sectional view of a toner replenishing device 10 provided with a vibration plate for preventing toner from falling according to the present invention;
FIG. 2 shows its side sectional view. FIG. 3 is a perspective view of the diaphragm, and FIG. 4 is a perspective view of a cam member that vibrates the diaphragm.

Slightly below the inner wall surface of the toner storage chamber main body (hopper) 11, two inclined surfaces 11a and 11b are integrally formed. The surface 11b forms an inverted trapezoidal cross-sectional shape, and these wall surfaces and the opposing wall surface form a box shape, which is integrally molded from a synthetic resin material.

A lid member 12 having a toner replenishing means is provided at the upper open portion of the hopper 11 to form a hermetically sealed state.

A toner conveying screw 13 and a stirring shaft 21 are rotatably supported at the bottom of the hopper 11.

In FIG. 2, a gear G2 is fixed to the right end of the conveyance screw 13, and the hopper 11
It is driven and rotated by a gear G1 that is integral with the drive shaft of a drive motor M provided on the outer wall of the motor. The left end portion of the conveying screw 13 is pivotally supported by a toner supply cylinder 14 . Supply port 14 below the supply cylinder 14
a is fitted around the outer periphery of the toner supply cylinder 14,
It can be opened and closed by a shutter cylinder 15 that is biased by a spring and can move in a straight line. That is, when the developing device 6 is attached to the toner replenishing device fixed to the main body of the copying machine, the toner receptacle 6 of the developing device 6 is
A part of the shutter cylinder 15 presses the shutter cylinder 15, moves straight to the right, and stops, and at this time, the replenishment port 14a of the replenishment cylinder 14 and the opening 15a of the shutter cylinder are aligned and become open. In this state, the toner T in the hopper 11 is sent out to the left by the conveyance screw 13, and near the left shaft end,
The toner is dropped and replenished into the developing device 6 from the toner receiving port 6c through the through hole between the replenishing port 14a and the opening 15a.

A gear G3 is fixed to the right end of the stirring shaft 21 which is supported above the conveying screw 13, and the gear G3 meshes with the gear G1 which is integral with the drive shaft of the drive motor M so as to be rotatable. ing.

Two cam members 22 are screwed to the middle of the stirring shaft 21, as shown in FIG. The cam member 22 has a holding portion 22a having a U-shaped cross section.
and a large diameter cam piece portion 22b having a large operating radius.
and a small diameter cam piece portion 22c having a small operating radius.
It consists of a metal plate with good thermal conductivity that is pressed and bent into an integral mold. For example, it is made by processing a 1 mm thick silver top plate (manufactured by Nippon Steel Corporation), which is a steel plate coated with a silicone resin coating.
It is also possible to perform molding using a sintered alloy.

On the other hand, the diaphragm 23 for preventing the toner from falling is the third
As shown in the figure, it is a sieve-shaped plate with many holes 23g, and has a first plate surface part 23a and a bent part 2.
3c to form a predetermined angle of inclination. The first plate surface portion 23a can slide in contact with the inclined surface 11a of the hopper 11 (see FIG. 1). The second plate surface portion 23b is capable of sliding in contact with the inclined surface 11b of the hopper 11 (see FIG. 2).

On the upper surface side of the first plate surface portion 23a, four protruding surfaces 23d protrude to a predetermined height by extrusion drawing press processing, and each of the two protruding surfaces 23d
A cam guide plate 24, which is an example of a cam guide portion, is fixed with a screw on each portion d.

The cam guide plate 24 includes a mounting surface portion 24a,
It consists of two upright surface portions 24b rising at right angles from the mounting surface portion 24a, and the upright surface portions 24b are connected at the top to form a single body. Cam guide plate 24
is made by press bending a metal plate with good thermal conductivity and wear resistance, such as phosphor bronze.

The cam member 22 is fitted onto the inner surface of the upright surface portion 24b of the cam guide plate 24, as shown in FIG. Here, the sum of the radii of the large-diameter cam piece portion 22b and the small-diameter cam piece portion 22c of the cam member 22 is set to be slightly smaller than the inner wall interval of the upright surface portion 24b.

Note that the elongated hole 23e located above the first plate surface portion 23a of the diaphragm 23 is connected to the inclined surface 1 of the hopper 11.
It is slidably fitted into a guide boss 11c protruding from 1a to guide the diaphragm 23 to reciprocate in one direction.

In addition, when the diaphragm 23 rises from the inclined surface 11a, the two protrusions 23f rising near the bottom of the diaphragm 23 hit the inner surface of the upright wall 11d of the hopper 11 to keep the rise below a certain amount. regulate.

Next, the operations of the diaphragm 23, cam guide plate 24, and cam member 22 according to the present invention will be explained.

When the amount of toner in the developing device 6 decreases, this is detected by a toner concentration detection means (not shown). The detection signal rotates the drive motor M, and the toner conveying screw 13 starts rotating via the gears G1 and G2, and the toner near the bottom of the hopper 11 is sent out in the direction of the supply cylinder 14. The toner then falls and is replenished into the developing device 6 through the replenishing port 14a of the replenishing cylinder 14, through the opening 15a of the shutter cylinder 15, and through the toner receiving port 6c of the developing device 6. Reference numeral 16 denotes a remaining amount detecting means for notifying that the toner in the hopper is consumed and that toner needs to be replenished.

At the same time, the drive motor M rotates the gears G1, G
The stirring shaft 21 is rotationally driven through the stirring shaft 2.
The cam member 22 fixedly attached to 1 also rotates fully. Due to the full rotation of the cam member 22, the two cam pieces 22b and 22c with different radii rotate in the direction of the arrow in FIG. The first plate surface portion 23a of the diaphragm 23, which is integral with the diaphragm 23, is reciprocated along the inclined surface 11a of the hopper 11 in the direction of the arrow in FIG. At the same time, the first plate surface portion 2
The second plate surface portion 23b, which is integral with the hopper 3a, reciprocates in the direction of the arrow along the inclined surface 11b of the hopper 11, as shown in FIG.

More specifically, the large diameter cam piece 22b of the rotating cam member 22 presses against the upper inner surface of the cam guide plate 24 and forcibly pushes up the cam guide plate 24 diagonally upward to move the diaphragm 23 back. However, as the large-diameter cam piece 22b rotates further and the large-diameter cam piece 22b separates from the upper inner surface of the cam guide plate 24 and comes into contact with the small-diameter cam piece 22c, the dead weight of the diaphragm 23 and the diaphragm 23 accumulate. Due to the weight of the toner, the diaphragm 23 slides down and back along the inclined surfaces 11a and 11b. In this way, the cam piece portions 22b, 22c
Since the contact surface intermittently contacts the inner surface (cam guide surface) of the cam guide plate 24, little heat is generated at the contact surface. In addition, the heat generated at the contact surface is removed by the cam guide plate 24, which is made of a metal material with good thermal conductivity, and the cam member 2.
2. Since the heat is radiated through the stirring shaft 21 and the vibration plate 23, the toner does not solidify due to heat accumulation.

As described above, when the first plate surface part 23a and the second plate surface part 23b of the diaphragm 23 reciprocate diagonally upward due to the rotation of the cam member 22, they solidify near the conveyance screw 13 and become bridge-like to form a cavity. The toner can maintain a fluid state without solidifying. Note that the large number of holes 23g formed in both plate surface portions 23a and 23b of the diaphragm 23 effectively act on the vibrational fall of the toner.

FIG. 5 is a partial perspective view showing another embodiment of the toner replenishing device according to the present invention.

In this embodiment, the diaphragm 23 is divided into two parts, one cam guide plate 34A is fixed on one diaphragm 33A, and the cam guide plate 34A is vibrated by a cam member 32A fixed to the stirring shaft 31. Also, the other diaphragm 33
Another cam member 32B is provided with another cam guide plate 34B fixedly installed on the cam shaft 31 and whose phase is shifted by 180 degrees to the cam shaft 31.
make it vibrate. That is, since the large-diameter cam piece 32Ab of the cam member 32A and the large-diameter cam piece 32Bb of the cam member 32B are fixed to the camshaft 31 with a phase shift of 180 degrees, the camshaft 31
One rotation drive of the two diaphragms 33A, 33
B alternately reciprocates. As a result, the diaphragm 33
Since the pushing up driving forces of A and 33B are distributed and divided into half each, there is an advantage that the load on the drive motor M can be small.

[Effect of idea]

According to the present invention, the perforated diaphragm is vibrated by being driven back and forth by the rotation of the cam means.
It is possible to reliably prevent cavitation due to toner bridging and to always perform appropriate toner replenishment.

Furthermore, since the cam means is made of a material with good thermal conductivity, it is effective in preventing coagulation and granulation of the toner due to the heat dissipation effect. This is because when the granulated toner is replenished into the developing device, striped or lumpy white spots appear on the copied image on the recording paper, so preventing granulation has an excellent effect on improving the quality of the copied image.

Furthermore, by dividing the diaphragm into two parts, it is not only useful to reduce the torque of the drive motor, but also to reduce the driving load on the diaphragm due to the increased weight of toner, especially in the case of toner replenishment devices that store large and large amounts of toner. be.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of the toner replenishing device according to the present invention, FIG. 2 is a side sectional view of the device, FIG. 3 is a partial perspective view of a diaphragm for preventing toner from falling, and FIG. 4 is a perspective view of a cam member. 5 is a perspective view showing another embodiment of the toner replenishing device according to the present invention, and FIG. 6 is a configuration diagram of a copying machine equipped with a conventional toner replenishing device. 6... Developing device, 7, 10... Toner supply device, 11... Toner storage chamber (hopper), 11a,
11b... Inclined surface, 13... Conveyance screw, 1
6... Toner remaining amount detection means, 21, 31... Stirring shaft, 22, 32A, 32B... Cam member, 22
b, 22c...cam piece, 23, 33A, 33B
...Vibration plate, 23a...First plate surface portion, 23b...
Second plate surface part, 23g...hole, 24, 34A, 34
B...Cam guide plate, 24b...Upright surface, M...
Drive motor, G1, G2, G3...gears.

Claims (1)

[Scope of utility model registration request] A diaphragm for preventing toner from falling is provided close to the inclined inner wall surface of the replenishment box where toner is replenished, and a cam guide portion with good thermal conductivity is provided on the diaphragm. The cam guide section is intermittently pressed by a thermally conductive cam means to swing the diaphragm and radiate heat generated by friction at the pressing section between the cam guide section and the cam means. A toner replenishing device characterized by: