JP3168504B2 - Carriage moving mechanism and corona charger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a carriage moving mechanism for moving a carriage along a screw by rotating the screw, and a corona charger having the carriage moving mechanism.

[0002]

2. Description of the Related Art In an image forming apparatus employing an electrophotographic method, various types of charging means are used to charge a photosensitive member for forming a latent image to a predetermined potential. Among them, a corona charger is widely used. Used. The corona charger applies a high voltage to a charging wire stretched along the surface of the photoconductor, and charges the photoconductor by ionizing air near the charging wire. In this case, if the charging wire is contaminated with toner, dust, or the like due to durability or the like, not only the charging efficiency is reduced, but also the image quality such as image unevenness may be caused due to uneven charging of the photoreceptor surface.

Therefore, a corona charger 130 having an automatic charging wire cleaning mechanism shown in FIGS. 12 and 13 has been proposed. The charging wire automatic cleaning mechanism is shown in FIG.
As shown in FIG. 1, a cleaning pad 102 in contact with a charging wire 101, a carriage 103 holding the cleaning pad 102, and the carriage 103 being connected to the charging wire 101.
It is configured to include a propulsion means for moving along.

As shown in FIG. 12, a carriage 103 has a pair of left and right rails 104 having a U-shaped cross section and provided on the inner surfaces of left and right shield plates 112 so as to face each other.
(Only one of them is shown in FIG. 12).
1, the cleaning pad 10 which holds the charging wire 101 from both sides thereof.
Holding 2. As shown in FIG. 13, a guide portion 105 is formed on the carriage 103, and a screw 106 is inserted through the guide portion 105.
A projection 107 projecting from a part of the guide 105 is engaged with a spiral groove 106 a of the screw 106.

When the screw 106 is rotationally driven by an external drive source, the carriage 103 moves along the screw 106 by receiving a propulsive force from the screw 106 at the protrusion 107, and the moving direction of the screw 106 is Depends on the direction of rotation. Therefore, the carriage 103 holding the cleaning pad 102 can be reciprocated along the charging wire 101 by controlling the driving of the screw 106 and switching the rotation direction thereof, and the cleaning pad 102 reciprocally moves together with the carriage 103. The charging wire 101 can be automatically cleaned.

[0006]

However, in the above-described conventional automatic charging wire cleaning mechanism, since the propulsion force of the carriage 103 is entirely received by the projection 107, there is a disadvantage that the projection 107 wears quickly due to durability. .
When the protrusion 107 is worn, the amount of engagement of the protrusion 107 with the helical groove 106a of the screw 106 decreases, so that the propulsive force transmitted from the screw 106 to the carriage 103 via the protrusion 107 decreases, and 1
03 is not smoothly moved, or the carriage 103
May stop while moving, and the like.

In the conventional charging wire automatic cleaning mechanism, the carriage 103 is slightly inclined with respect to the screw 106, and the straightness of the carriage 103 is deteriorated due to the inclination. There are also drawbacks, such as an increase in frictional resistance between the 103s, impairing smooth movement of the carriage 103, and abrasion of the carriage 103 and the like due to an increase in load. The deterioration of the straightness of the carriage 103 occurs for the following reasons.

That is, like the projection 107, the carriage 1
When the point receiving the propulsive force F from the screw 106 in the position 03 is located forward of the center of gravity G of the carriage 103 in the traveling direction, even if the carriage 103 is slightly inclined as shown in FIG. Correct the carriage 103
Generates a moment Mf acting in a direction parallel to the screw 106.

However, when the point receiving the propulsive force F from the screw 106 is located behind the center of gravity G in the traveling direction, the propulsive force F further rotates the inclined carriage 103 as shown in FIG. This generates a moment Mr that causes the carriage 103 to move straight. Actually, it is difficult to completely match the point receiving the propulsive force F with the center of gravity G of the carriage 103. Therefore, when the carriage 103 is reciprocated, one of the forward path and the return path is behind the center of gravity G. F, the straightness of the carriage 103 deteriorates.

In addition, since a force that deteriorates the straightness is generated in the carriage 103 during operation due to friction with the rail 104 or the like, even if the point of action of the center of gravity G and the point of action of the propulsion force F are matched, the carriage 103 is inclined. No moment Mf for correcting the carriage 103 is generated, and the straightness of the carriage 103 is also impaired.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a carriage moving mechanism and a corona charger which can achieve smooth movement of a carriage and improved durability with a simple structure. Is to do.

[0012]

In order to achieve the above-mentioned object, according to the first aspect of the present invention, there is provided a screw having a helical groove formed in a round shaft, and a projection engaging with the helical groove of the screw. A carriage moving mechanism that moves the carriage along the screw by rotationally driving the screw, wherein the carriage is provided with at least two protrusions ;
At the time of movement,
The propulsion force from the screw is mainly
It is characterized by being constituted so that it can be transmitted to .

[0013] According to the second aspect of the present invention , a spiral groove is formed on the round shaft.
The screw formed and the spiral groove of the screw
A carriage having a projection to be engaged,
Drive the carriage by rotating the screw.
The carriage moving mechanism that moves along the screw
And the carriage is provided with two protrusions, and between the two protrusions.
L is the pitch in the screw axis direction, and the screw is spiral
When the pitch of the groove is a, the following (1) and (2)
Engagement; (1) L is not an integer multiple of a, when the n the largest integer that satisfies (2) L> n · a ,
N + 1 screw spiral groove peaks between two protrusions
enter. It is characterized by being comprised so that it may satisfy.

According to a third aspect of the present invention, in the first or the second aspect of the present invention, the protrusion is formed with respect to the screw.
It is characterized by being biased .

According to a fourth aspect of the present invention, in the first, second or third aspect of the present invention, the protrusion is formed by the screw.
When a force exceeding a predetermined level is applied, the screw
It is characterized in that it is configured to be able to deviate from the spiral groove .

The invention according to claim 5 is the invention according to claim 1, 2 or
3. The invention according to claim 3 , wherein the protruding portion is formed by a single leaf spring.
And held by the carriage, and the leaf spring
That the screw is biased by
It is characterized by.

According to a sixth aspect of the present invention, there is provided a charging wire,
Cleaning means for contacting and cleaning the charging wire;
Move the carriage holding the cleaning means along the charging wire
A carriage movement mechanism that moves the carriage
The driving mechanism is a screw formed by forming a spiral groove on the round shaft,
Having a projection engaging with a spiral groove of the screw;
In a corona charger including a carriage,
At least two on the carriage of the carriage moving mechanism
Is provided, and when the carriage moves,
Swivel the protrusion that is more forward in the carriage travel direction.
It was structured so that the driving force from Clew could be conveyed mainly.
And features.

According to a seventh aspect of the present invention, there is provided a charging wire,
Cleaning means for contacting and cleaning the charging wire;
A carriage moving mechanism for moving a carriage holding the cleaning means along the charging wire, wherein the carriage moving mechanism has a screw formed by forming a spiral groove on a round shaft;
In a corona charger including the carriage having a protrusion engaged with a spiral groove of the screw,
Two projections provided on the carriage of the carriage moving mechanism, the pitch of the screw axis direction between the two projections L, scan
When the pitch of the screw spiral groove is a,
(1) and (2); (1) L is not an integral multiple of a, and (2) When the largest integer satisfying L> n · a is n,
N + 1 screw spiral groove peaks between two protrusions
enter. It is characterized by being comprised so that it may satisfy .

[0019]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

<Embodiment 1> FIG. 1 is a side sectional view showing the structure of a charging wire automatic cleaning mechanism of a corona charger including a carriage moving mechanism according to Embodiment 1 of the present invention, and FIG.
3 is a partial cross-sectional view for explaining the operation of the charging wire automatic cleaning mechanism.

In the corona charger 30 shown in FIG.
Reference numeral 2 denotes a shield plate, and 1 denotes a charging wire. The charging wire 1 is stretched between charging blocks 10 and 11 provided at both ends of the shield plate 12, and is connected to a high voltage of several kV from an external terminal (not shown). Is applied, a corona discharge occurs between itself and the shield plate 12. The charging wire 1 is sandwiched between cleaning pads 2 (2a, 2b) which are divided into left and right parts. As the cleaning pad 2, a pad having both elasticity and polishing ability, such as rubber containing an abrasive, is used.

A screw 6 having a helical groove 6a formed in a round shaft is rotatably supported between the charging blocks 10 and 11 and below the charging wire 1. A guide section 5 formed on the carriage 3 is movably fitted to the carriage 3.

The carriage 3 is movably supported along the charging wire 1 by rails (not shown) provided on the inner surface of the shield plate 12 so as to face the cleaning pad 2. I have. Two projections 7 are provided at both front and rear ends of the guide portion 5 of the carriage 3.
a and 7b are protruded, and both protrusions 7a and 7b are engaged with the spiral groove 6a of the screw 6.

In this embodiment, the pitch L between the two projections 7a and 7b in the direction of the screw 6 is L = 1.
The pitch a of the spiral groove 6a of the screw 6 is set to a = 3.8 mm, and the peak of the spiral groove 6a of the screw 6 is 5 mm between the two projections 7a and 7b.
It is configured to fit in.

The carriage 3 holding the cleaning pad 2 is stationary at the standby position at the end of the charging wire 1 except during the wire cleaning operation, and does not affect the charging of the photosensitive member or the like.

At the time of wire cleaning, first, the screw 6 is driven to rotate by an external power such as a motor or the like.
The carriage 3 is moved in the direction of the arrow. At that time, FIG.
As shown in FIG. 5, the front projection 7a of the two projections 7a and 7b in the traveling direction comes into contact with the mountain of the spiral groove 6a of the screw 6 first, and the propulsive force F is transmitted to the front projection 7a. . After moving the carriage 3 to a predetermined position while cleaning the charging wire 1 with the pad 2 as it is, when the screw 6 is rotated in the opposite direction, as shown in FIG. The peak of the helical groove 6a of the screw 6 abuts on the projection 7b, and the carriage 3 receives the propulsion force F from the projection 7b and moves in the direction of the arrow in FIG.
The pad 2 can return to a predetermined standby position while cleaning the charging wire 1.

As described above, the carriage 3 reciprocates and cleans the charging wire 1 with the cleaning pad 2. However, the carriage 3 alternately protrudes from the protrusions 7a and 7b located forward in the traveling direction of the carriage 3 both in the forward path and in the backward path. In order to obtain a force F, a moment Mf for maintaining the straightness as shown in FIG. 14 always acts on the carriage 3, and smooth and efficient movement of the carriage 3 is realized with a simple configuration.

In this embodiment, the pitch L between the two projections 7a and 7b in the direction of the screw 6 is L = 1.
The pitch a of the spiral groove 6a of the screw 6 is set to a = 3.8 mm, and the both protrusions 7a,
The helical groove 6a of the screw 6 is configured to have five peaks between the screws 7b, and these ridges are formed by the following (1) and (2).
(1) When L is not an integral multiple of a and (2) n is a maximum integer satisfying L> n · a, n + 1 screw groove peaks are formed between the two projections. Can be freely selected, and the same effect as in the present embodiment can be obtained.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a sectional side view showing a configuration of a charging wire automatic cleaning mechanism of a corona charger including a carriage moving mechanism according to Embodiment 2 of the present invention, and FIGS. 5 to 7 show the operation of the charging wire automatic cleaning mechanism. FIG. 4 is a partial cross-sectional view for explaining, in which the same elements as those shown in FIGS. 1 to 3 are denoted by the same reference numerals.

Also in this embodiment, the carriage 3 is supported by a rail (not shown) so as to be movable along the charging wire 1. The carriage 3 supports the cleaning pad 2 that holds the charging wire 1, and one of the cleaning pads 2. The guide part 5 provided in the part is fitted to the screw 6. At both ends of the carriage 3, sliders 8a and 8b made of resin or the like having high slidability are supported.
A and 8b are urged in the direction of the screw 6 by elastic springs 9a and 9b, and each tip is engaged with the spiral groove 6a of the screw 6.

Here, the operation of the charging wire automatic cleaning mechanism according to the present embodiment will be described.

The carriage 3 holding the cleaning pad 2 is stationary at the standby position at the end of the charging wire 1 except during the wire cleaning operation, and does not affect the charging of the photosensitive member or the like.

At the time of wire cleaning, first, the screw 6 is driven to rotate by an external power such as a motor or the like.
The carriage 3 is moved in the direction of the arrow. At this time, at least one of the two sliders 8a and 8b comes into contact with the ridge of the spiral groove of the screw 6, and the driving force F is transmitted thereto.

As shown in FIG. 5, when the slider 8b on the rear side in the traveling direction of the carriage 3 comes into contact with the helical groove 6a of the screw 6, and the propulsion force F is mainly transmitted to the rear slider 8b, FIG. As shown, there is a possibility that the straightness of the carriage 3 may be deteriorated. In this case, the friction between the carriage 3 and a rail or screw 6 (not shown) increases, and a load is applied to the carriage 3 to prevent the carriage 3 from moving. work. When such a load acts on the carriage 3, the force acting on the rear slider 8b receiving the propulsive force F from the screw 6 increases, and the elastic spring 9b is deformed to retract the slider 8b as shown in FIG. On the contrary, the propulsive force F transmitted to the front slider 8a increases. When the propulsive force to the forward slider 8a increases in this way, a moment Mf acts to maintain the straightness of the carriage 3 as shown in FIG.
The carriage 3 can move smoothly and well.

The carriage 3 is composed of a pad 2 and a charging wire 1
Is moved along the charging wire 1 to the end opposite to the standby position while cleaning. Then, the carriage 3 which has reached the end portion abuts on the charging block 11 and cannot be moved any further. At this time, the sliders 8a and 8b receiving the propulsive force F from the screw 6 have elastic springs as shown in FIG. The propulsive force F from the screw 6 can be released by climbing over the helical groove 6a of the screw 6 by the elasticity of the screws 9a and 9b, and the screw 6 can continue to rotate. For this reason, it is not necessary to detect the arrival of the carriage 3 at the end by a sensor or the like and to cut off the driving of the screw driving motor, and it is sufficient to control the screw driving motor to rotate by a timer or the like for a certain period of time.

After the screw 6 is rotated for a time necessary for the carriage 3 to reach the end opposite to the standby position,
It is driven for a certain time in the opposite direction. When the screw 6 is reversed, the carriage 3 is moved by the cleaning pad 2 to the charging wire 1.
Is moved toward the end of the charging wire 1 which is a standby position while cleaning, and abuts on the charging block 10 and stops at the standby position. Also at this time, similarly to the forward path, when the propulsive force F from the screw 6 concentrates on the slider 8a located rearward in the traveling direction of the carriage 3 and the straightness of the carriage 3 deteriorates, it naturally acts on the front slider 8b. Since the propulsion force F increases and the straightness of the carriage 3 is improved, the carriage 3 can move smoothly.

As described above, in the charging wire automatic cleaning mechanism using the carriage moving mechanism according to the present embodiment,
The carriage 3 can be satisfactorily reciprocated along the charging wire 1 with a simple configuration and simple control means, and the cost reduction and long life of the charging wire automatic cleaning mechanism can be realized.

<Third Embodiment> Next, a third embodiment of the present invention will be described with reference to FIGS. FIG. 8 is a partial perspective view showing the configuration of a charging wire automatic cleaning mechanism of a corona charger including a carriage moving mechanism according to Embodiment 3 of the present invention, and FIG. 9 is a diagram of the charging wire automatic cleaning mechanism of the corona charger. FIG. 10 is a partial sectional view showing the configuration, and FIG.
11A and 11B are a front view and a side view of a leaf spring used in the automatic charging wire cleaning mechanism. In these figures, the same elements as those shown in FIGS. Are denoted by the same reference numerals.

Also in this embodiment, the carriage 3 is supported by the rail 4 so as to be movable along the charging wire 1. The carriage 3 supports the cleaning pad 2 for holding the charging wire 1, and a part thereof. The provided guide part 5 is fitted to the screw 6. The carriage 3 has a slider 22 made of a resin or the like having high slidability.
a, 22b are supported, and both sliders 22a, 22b are supported.
b is attached to the elastic leaf spring 20 by heat caulking.

The leaf spring 20 is provided with a screw 21 on the carriage 3.
9 and 10, the sliders 22a and 22b are engaged with the spiral groove 6a of the screw 6, as shown in FIGS. Here, the leaf spring 20 has a bent portion in the middle as shown in FIG.
10, the sliders 22a and 22b are urged in the direction of the screw 6 and engaged with the spiral groove 6a as shown in FIG.

When the screw 6 is rotationally driven by an external driving means (not shown), the driving force is transmitted to the sliders 22a and 22b engaged with the helical grooves 6a of the screw 6, and the carriage 3 moves. However, at this time, the propulsive force that the carriage 3 receives from the screw 6 can be dispersed by the two sliders 22a and 22b.
22b can be reduced.

Further, the sliders 22a, 22b
Even if the slider 2 is worn out, the slider 2
Since the tips of the sliders 2a and 22b are shifted toward the screw 6, the engagement portions of the sliders 22a and 22b with the helical groove 6a are not reduced, and the carriage 3 can be continuously provided with a sufficient propulsive force.

Further, if the wear of the sliders 22a and 22b has progressed, the sliders 22a and 22b together with the leaf spring 20 can be easily replaced with new ones simply by removing the screws 21.

As described above, in the carriage moving mechanism according to the present embodiment, it is possible to improve the durability and the maintainability of the sliders 22a and 22b that transmit the driving force from the screw 6 to the carriage 3 with a simple configuration. .

[0045]

As is apparent from the above description, according to the present invention, a screw formed by forming a spiral groove in a round shaft;
In a corona charger comprising a carriage having a projection engaged with a spiral groove of the screw, the carriage moving mechanism for moving the carriage along the screw by rotating the screw, or a corona charger including the carriage moving mechanism. , At least two on the carriage
One of the projections is provided, the protruding portion at the time the carriage movement
To the protrusion that is more forward in the carriage travel direction.
It is configured so that the thrust from the screw is mainly transmitted,
Alternatively, two protrusions are provided on the carriage, and between the two protrusions.
L is the pitch in the screw axis direction, and the screw is spiral
When the pitch of the groove is a, the following (1) and (2)
Engagement; (1) L is not an integer multiple of a, when the n the largest integer that satisfies (2) L> n · a ,
N + 1 screw spiral groove peaks between two protrusions
enter. Therefore, the effect is obtained that the carriage can be smoothly moved and the durability can be improved with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a configuration of a charging wire automatic cleaning mechanism of a corona charger including a carriage moving mechanism according to Embodiment 1 of the present invention.

FIG. 2 is a partial cross-sectional view illustrating an operation of a charging wire automatic cleaning mechanism of the corona charger including the carriage moving mechanism according to Embodiment 1 of the present invention.

FIG. 3 is a partial cross-sectional view illustrating an operation of a charging wire automatic cleaning mechanism of the corona charger including the carriage moving mechanism according to the first embodiment of the present invention.

FIG. 4 is a side sectional view showing a configuration of a charging wire automatic cleaning mechanism of a corona charger including a carriage moving mechanism according to Embodiment 2 of the present invention.

FIG. 5 is a partial cross-sectional view illustrating an operation of a charging wire automatic cleaning mechanism of a corona charger including a carriage moving mechanism according to Embodiment 2 of the present invention.

FIG. 6 is a partial cross-sectional view illustrating an operation of a charging wire automatic cleaning mechanism of a corona charger including a carriage moving mechanism according to Embodiment 2 of the present invention.

FIG. 7 is a partial cross-sectional view illustrating an operation of a charging wire automatic cleaning mechanism of a corona charger including a carriage moving mechanism according to Embodiment 2 of the present invention.

FIG. 8 is a partial perspective view illustrating a configuration of a charging wire automatic cleaning mechanism of a corona charger including a carriage moving mechanism according to Embodiment 3 of the present invention.

FIG. 9 is a partial sectional view illustrating a configuration of a charging wire automatic cleaning mechanism of a corona charger including a carriage moving mechanism according to Embodiment 3 of the present invention.

FIG. 10 is a sectional view taken along line AA of FIG. 9;

FIG. 11 is a front view and a side view of a leaf spring used for a charging wire automatic cleaning mechanism of a corona charger including a carriage moving mechanism according to Embodiment 3 of the present invention.

FIG. 12 is a perspective view of a corona charger including a conventional carriage moving mechanism.

FIG. 13 is a sectional view of a corona charger including a conventional carriage moving mechanism.

FIG. 14 is a diagram schematically illustrating a moment generated in a carriage that receives a propulsive force ahead of the center of gravity in the traveling direction.

FIG. 15 is a diagram schematically illustrating a moment generated in a carriage that receives a propulsive force behind the center of gravity in the traveling direction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Charging wire 2 Cleaning pad (cleaning means) 3 Carriage 6 Screw 6a Helical groove 7a, 7b Projection 8a, 8b Slider 9a, 9b Elastic spring 20 Leaf spring 22a, 22b Slider 30 Corona charger

Claims (7)

(57) [Claims] 1. A screw having a spiral groove formed on a round shaft, and a carriage having a projection engaging with the spiral groove of the screw, the carriage being rotated by driving the screw to rotate the screw. A carriage moving mechanism for moving at least two projections on the carriage ;
When the ridge moves, the protrusions
Propulsion force from the screw on the projection that is more forward
The carriage moving mechanism is configured to mainly transmit the information . 2. A screw having a spiral groove formed in a round shaft.
And a projection engaging with the spiral groove of the screw.
It is configured to include a carriage that rotates the screw
To move the carriage along the screw
In the carriage moving mechanism, the carriage is provided with two protrusions, and a gap between the protrusions is provided.
The pitch in the screw axis direction is L, and the spiral groove of the screw is
When the pitch is a, the following relations (1) and (2); (1) L is not an integral multiple of a, and (2) When the maximum integer satisfying L> n · a is n,
N + 1 screw spiral groove peaks between two protrusions
enter. A carriage moving mechanism configured to satisfy the following . 3. The screw is attached to the screw.
The carriage moving mechanism according to claim 1, wherein the carriage moving mechanism is energized . 4. The method according to claim 1, wherein the projection is a predetermined distance from the screw.
When receiving the above force, the screw may be elastically helical groove.
4. The carriage moving mechanism according to 1, 2, or 3, wherein the carriage moving mechanism is configured to be detached . 5. The method according to claim 1, wherein the protrusion is formed by a single leaf spring.
While being held by the carriage, by the leaf spring
Characterized in that it is configured to be biased by the screw
The carriage moving mechanism according to claim 1, 2 or 3, wherein 6. A charging wire and abutting on the charging wire.
Cleaning means for cleaning it and holding the cleaning means
Kyari' Before moving the carriage along the charging wire
The carriage movement mechanism has a spiral shape with a round shaft.
A screw formed with a groove, and a helical shape of the screw
The carriage includes the carriage having a protrusion engaged with the groove.
In the corona charger to be formed, the carriage of the carriage moving mechanism has at least two
Is provided, and when the carriage moves,
Swivel the protrusion that is more forward in the carriage travel direction.
It was structured so that the driving force from Clew could be conveyed mainly.
And a corona charger. 7. A charging device comprising: a charging wire; cleaning means for contacting and cleaning the charging wire; and a carriage moving mechanism for moving a carriage holding the cleaning means along the charging wire. In a corona charger including a screw having a spiral groove formed on a shaft and the carriage having a protrusion engaging with the spiral groove of the screw, two protrusions are provided on a carriage of the carriage moving mechanism. And the pitch in the screw axis direction between both projections is L,
When the pitch of the screw spiral groove is a,
(1) and (2); (1) L is not an integral multiple of a, and (2) When the largest integer satisfying L> n · a is n,
N + 1 screw spiral groove peaks between two protrusions
enter. A corona charger characterized by satisfying the following .