JP2023160070A - Wiping device and image forming device - Google Patents

Abstract

To provide a wiping device that can appropriately suppress contact pressure of a wiping member, while suppressing contact control of the wiping member from getting complicated and suppressing costs from increasing.SOLUTION: The wiping device comprises: a wiping member 22 that can contact a nozzle surface 101a of a liquid discharge head 101 and moves relatively with respect to the nozzle surface to wipe the nozzle surface; and wiping member moving means that moves the wiping member in a direction in which the wiping member contacts the nozzle surface or in a direction in which the wiping member separates from the nozzle surface. The wiping member moving means has a driving source 26 and a torque limiter 24 provided between the driving source and the wiping member. The torque limiter cuts off driving force to the wiping member, if torque exceeding a predetermined value occurs when the wiping member contacts the nozzle surface.SELECTED DRAWING: Figure 1

Description

The present invention relates to a wiping device and an image forming device.

In an inkjet image forming apparatus, in order to stably eject ink droplets, it is necessary to maintain the inside and vicinity of a nozzle in a good condition. 2. Description of the Related Art In order to maintain the interior and vicinity of a nozzle in a good condition, a technique is known in which the nozzle surface of an inkjet head is wiped with a wiping member.

Patent Document 1 discloses a wiping device in which a single traveling wiping sheet is brought into sliding contact with each of the nozzle surfaces of a plurality of droplet ejection heads to perform a wiping operation. In Patent Document 1, a sheet feeding means, a plurality of sheet pressing members that press a wiping sheet relatively against a nozzle surface, and a pool of wiping sheets to be provided to a droplet ejection head on the downstream side in a feeding direction are formed between each sheet pressing member. A plurality of pool means are disclosed. According to Patent Document 1, wiping of a plurality of droplet ejection heads can be performed efficiently in a short time.

Regarding wiping of the nozzle surface, it is necessary to control the wiping member to a predetermined contact pressure or biting amount. If the contact pressure is too low, dirt adhering to the nozzle surface cannot be sufficiently wiped away. On the other hand, if the contact pressure is too large, wiping will accelerate deterioration of the nozzle surface and the wiping member.

On the other hand, in order to control the contact pressure of the wiping member, a configuration may be considered in which the stop position when pressing the wiping member against the nozzle surface is controlled. However, since the contact pressure is determined by, for example, the relative distance between the nozzle surface and the wiping member, the contact pressure will vary due to variations in the distance between the two, as well as component errors, assembly errors, and the like.

On the other hand, as a technique for controlling the contact pressure, it has been considered to detect the contact of the wiping member with a pressure sensor or the like. A technique has been proposed that controls the stop position of the wiping member by stopping the driving of the wiping member when the detected pressure reaches a predetermined value.

Patent Document 2 discloses a nozzle surface cleaning device that cleans the nozzle surface of an inkjet head using a wiping member. Patent Document 2 discloses an elevating device that relatively moves the nozzle surface and the wiping member up and down, a detection device that detects contact of the wiping member, and a device that relatively moves the wiping member and the nozzle surface along the nozzle surface. It is disclosed that the invention includes a wiping means and a control means for stopping the raising and lowering of the raising and lowering means and causing the wiping means to perform wiping at the raising and lowering stop position. According to Patent Document 2, it is possible to improve ejection stability by consistently wiping the nozzle surface of an inkjet head with the same pressure regardless of equipment or maintenance.

However, when controlling the stop position of the wiping member using a detection means such as a pressure sensor, there is a problem that the control becomes complicated. Furthermore, when a detection means such as a pressure sensor is used, there is a problem in that the cost increases due to an increase in the number of parts.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a wiping device that can appropriately control the contact pressure of the wiping member while suppressing the complexity of controlling the contact of the wiping member and suppressing an increase in cost.

In order to solve the above problems, the wiping device of the present invention includes a wiping member that can come into contact with a nozzle surface of a liquid ejection head and wipes the nozzle surface by moving relative to the nozzle surface; wiping member moving means for moving the wiping member in a direction in which the member comes into contact with the nozzle surface or in a direction in which the member is separated from the nozzle surface, and the wiping member moving means includes a drive source; and a torque limiter provided between the wiping members, and the torque limiter controls the drive to the wiping member when a torque exceeding a predetermined value is generated when the wiping member abuts the nozzle surface. It is characterized by blocking power.

According to the present invention, the contact pressure of the wiping member can be appropriately controlled while suppressing the complexity of controlling the contact of the wiping member and suppressing an increase in cost.

FIG. 2 is a schematic diagram of a main part of an example of an image forming apparatus according to the present invention, and is a schematic diagram illustrating an example of a state in which a wiping member is not in contact with a nozzle surface. FIG. 2 is a schematic diagram of a main part of an example of an image forming apparatus according to the present invention, and is a schematic diagram illustrating an example of a state in which a wiping member is in contact with a nozzle surface. FIG. 2 is a schematic view of a main part of an example of an image forming apparatus according to the present invention, and is another schematic view showing an example of a state in which a wiping member is in contact with a nozzle surface. FIG. 2 is a schematic view of a main part of an example of an image forming apparatus according to the present invention, in which a schematic diagram (A) shows an example of a state where the wiping member is not in contact with the nozzle surface, and a schematic diagram (A) shows an example of the state in which the wiping member is in contact with the nozzle surface. FIG. 3 is a schematic diagram (B) showing an example. FIG. 3 is a schematic diagram of main parts showing another example of the image forming apparatus according to the present invention, and is a schematic diagram (A) showing an example of a state in which the wiping member is not in contact with the nozzle surface, and a schematic diagram (A) showing an example in which the wiping member is in contact with the nozzle surface. It is a schematic diagram (B) showing an example of a state. FIG. 7 is a schematic view of a main part of another example of the image forming apparatus according to the present invention, and is a schematic view showing an example of a state in which a wiping member is in contact with a nozzle surface.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A wiping device and an image forming apparatus according to the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the embodiments shown below, and may be modified within the scope of those skilled in the art, such as other embodiments, additions, modifications, deletions, etc. These are also included within the scope of the present invention as long as they exhibit the functions and effects of the present invention.

The wiping device of the present invention includes a wiping member that can come into contact with a nozzle surface of a liquid ejection head and wipes the nozzle surface by moving relative to the nozzle surface, and the wiping member comes into contact with the nozzle surface. wiping member moving means for moving the wiping member in a direction or in a direction away from the nozzle surface, the wiping member moving means being provided with a drive source and between the drive source and the wiping member. and a torque limiter, wherein the torque limiter cuts off the driving force to the wiping member if a torque exceeding a predetermined value is generated when the wiping member abuts the nozzle surface. do.

According to the present invention, the contact pressure of the wiping member can be appropriately controlled while suppressing the complexity of controlling the contact of the wiping member and suppressing an increase in cost. Since the contact pressure can be appropriately controlled, dirt adhering to the nozzle surface can be sufficiently wiped away, and deterioration of the nozzle surface and the wiping member due to wiping can be suppressed. Thereby, the quality of cleaning the nozzle surface of the liquid ejection head can be improved, and the ejection stability can be improved.

Further, a device for discharging a liquid according to the present invention is characterized by comprising a liquid discharging head for discharging a liquid and a wiping device according to the present invention. According to the liquid ejecting device of the present invention, it is possible to obtain the above-described effects of the present invention, and also to improve cleaning quality and ejection stability, so that images of good quality can be formed.

In this embodiment, wiping may be referred to as cleaning, wiping, or the like. The wiping device may also be referred to as a cleaning device, a wiping device, or the like. The wiping member moving means may also be referred to as wiping member driving means. The nozzle surface may also be referred to as a head nozzle surface or the like. Examples of the liquid include ink, and examples of the liquid ejection head include an inkjet head. The liquid ejection head may be referred to as a head or the like, and may be one or more than one. A device that discharges liquid may be referred to as a liquid discharge device, an image forming device, a printing device, a recording device, or the like.

FIG. 1 is a schematic diagram showing an example of a device for discharging liquid according to the present embodiment, and is a diagram illustrating a state in which the wiping member is not in contact with the nozzle surface. FIG. 2 is another schematic diagram showing an example of the device for discharging liquid according to the present embodiment, and is a diagram illustrating a state in which the wiping member is in contact with the nozzle surface. FIG. 3 is another schematic diagram showing an example of the device for discharging liquid according to the present embodiment, and is a diagram illustrating a state further advanced from the state shown in FIG. 2.

The liquid ejection device of this embodiment includes a liquid ejection head 101 and a wiping device 20. The wiping device 20 includes a wiping member 22, a wiping member moving means, and other members and means as necessary.

The wiping member 22 can come into contact with the nozzle surface 101a of the liquid ejection head 101, and wipes the nozzle surface 101a by moving relative to the nozzle surface 101a. Wiping may be performed by moving the wiping member 22, or may be performed by moving the liquid ejection head 101. An example of the wiping direction is shown by arrow b in FIG. The wiping member 22 is supported by, for example, a support member 30, although this is not particularly limited.

The wiping member moving means includes a motor 26 (drive source), a torque limiter 24 provided between the motor 26 and the wiping member 22, and also includes a cam 28, a gear 32, and the like. The driving force from the motor 26 is transmitted via the torque limiter 24.

The wiping member moving means moves the wiping member 22 in a direction in which the wiping member 22 comes into contact with the nozzle surface 101a or in a direction in which it separates from the nozzle surface 101a. The direction in which the wiping member 22 comes into contact with the nozzle surface 101a or the direction in which it separates from the nozzle surface is indicated by a double-headed arrow a in FIG.

An example of wiping in this example will be explained.
The wiping device 20 of this example has a drive source, and a motor 26 is used as the drive source, for example. The motor 26 rotates a gear 32 and applies driving force to the support member 30 via the torque limiter 24 and cam 28. The gear 32 is rotated by the motor 26, and rotational force (torque) is transmitted to the cam 28. As a result, the cam 28 rotates, and the support member 30 moves up and down in the direction of arrow a. When wiping, the support member 30 is brought close to the nozzle surface 101a, and the wiping member 22 is brought into contact with the nozzle surface 101a (FIG. 2). Then, for example, by moving the wiping device 20 in the direction of arrow b, the nozzle surface 101a is wiped by the wiping member 22 (FIGS. 2 and 3).

Note that in order to wipe the nozzle surface 101a, the nozzle surface 101a and the wiping member 22 only need to move relative to each other, so the present embodiment is not limited to such an example. The wiping device 20 may not move, but the wiping member 22 may move, or the liquid ejection head 101 may move. Further, the drive source for moving the wiping member 22 relative to the nozzle surface 101a is not particularly limited, and for example, the motor 26 or other drive source may be used.

Since the motor 26 in this example is used to raise and lower the wiping member 22, it may also be referred to as a wiping member elevating motor.

In this embodiment, the wiping member moving means includes a torque limiter 24. Since the wiping device 20 has the wiping member moving means, it can be said that the wiping device 20 has the torque limiter 24.

The torque limiter 24 is configured to not transmit driving force when a predetermined load is applied. The torque limiter 24 cuts off the driving force from the motor 26 to the wiping member 22 when the driving force from the motor 26 to the wiping member 22 exceeds a predetermined value when the wiping member 22 contacts the nozzle surface 101a. Thereby, the stop position of the wiping member 22 in the vertical direction can be determined mechanically by the torque limiter 24, and the contact pressure when the wiping member 22 contacts the nozzle surface 101a can be appropriately controlled. be able to.

In this embodiment, the wiping member 22 is pressed against the nozzle surface 101a until the torque limiter 24 cuts off the driving force. Therefore, even if the position of the nozzle surface 101a varies due to errors, a predetermined contact pressure can be applied.

Further, in this embodiment, in order to control the contact pressure of the wiping member 22, it is sufficient to provide a torque limiter between the drive source and the wiping member. Therefore, for example, there is no need to provide a pressure sensor, and there is no need to feed back sensor information. Thereby, it is possible to suppress the control of the contact of the wiping member from becoming complicated and to suppress an increase in costs such as an increase in the number of parts.

In this embodiment, it is preferable that the contact pressure of the wiping member 22 against the nozzle surface 101a is determined by the upper limit value of the torque transmitted from the torque limiter 24 to the wiping member 22. The upper limit value of torque may also be referred to as maximum torque.

By doing so, the contact pressure when the wiping member 22 contacts the nozzle surface 101a can be set to a predetermined pressure determined by the specifications of the torque limiter 24. Further, there is no need to separately provide means for increasing the accuracy of the stopping position of the wiping member 22 in the vertical direction, and wiping can be performed with an appropriate contact pressure while simplifying the device configuration and control.

In order for the contact pressure of the wiping member 22 against the nozzle surface 101a to be determined by the upper limit value of the torque transmitted from the torque limiter 24 to the wiping member 22, for example, the relationship between the contact pressure and torque may be measured in advance. Another method is to select an appropriate torque limiter.

It is preferable that the wiping member moving means continues to apply a driving force in a direction in which the wiping member 22 contacts the nozzle surface 101a when the wiping member 22 moves relative to the nozzle surface 101a to wipe the nozzle surface 101a. This may be rephrased as, when wiping with the wiping member 22, the drive source is continuously driven in the direction in which the wiping member 22 contacts the nozzle surface 101a.

In this embodiment, when the wiping member 22 comes into contact with the nozzle surface 101a, if the driving force applied to the wiping member 22 exceeds a predetermined value by the torque limiter 24, the driving force is cut off. Therefore, when wiping with the wiping member 22, even if the wiping member 22 is continuously driven in the direction in which it contacts the nozzle surface 101a, the contact pressure can be prevented from exceeding the set value. On the other hand, by continuing to drive, it is possible to prevent the contact pressure from becoming low. Therefore, the nozzle surface 101a can be wiped while keeping the contact pressure of the wiping member 22 constant. The wiping member 22 can wipe the nozzle surface 101a while maintaining an appropriate contact pressure.

In the case of such a configuration, the position of the wiping member 22 that provides appropriate contact pressure can be maintained. The position of the wiping member 22 here refers to the position of the wiping member 22 in the vertical direction. With such a configuration, even if there are variations in the relative position of the wiping member 22 in the wiping direction and there are places where the distance between the wiping member 22 and the nozzle surface 101a changes, it is possible to perform wiping that follows it. can. For example, even if the nozzle surface 101a has irregularities, it continues to be driven during wiping, so it can wipe while applying a predetermined contact pressure following the irregular shape.

In this embodiment, it is preferable that the wiping member 22 is swingable with the direction of relative movement when wiping the nozzle surface 101a as a rotation axis. By doing so, even if the wiping member 22 and the nozzle surface 101a are relatively inclined, wiping can be performed in an appropriate contact posture that follows the nozzle surface 101a. Furthermore, even if the nozzle surface 101a has irregularities or is tilted, it can be wiped away with a targeted contact pressure.

In this manner, in the present embodiment, the contact attitude of the wiping member 22 can be determined by swinging the wiping member at an angle relative to the nozzle surface. Thereby, it is possible to suppress the occurrence of areas that are not wiped, to suppress unwiped areas, and to improve the cleaning quality.

An example is shown in FIG. FIG. 4(A) is a schematic diagram showing a state in which the wiping member 22 is not in contact with the nozzle surface 101a, and FIG. 4(B) is a schematic diagram showing a state in which the wiping member 22 is in contact with the nozzle surface 101a. It is a diagram.
Since the wiping member 22 is swingable with the wiping direction as the rotation axis, even if the nozzle surface 101a is tilted, the wiping member 22 can swing in accordance with the tilt of the nozzle surface 101a. Therefore, it is possible to wipe the nozzle surface 101a with a targeted contact pressure.

In the illustrated example, the wiping direction is, for example, the Y-axis direction, and the nozzle surface 101a is inclined, for example, with respect to the X-axis. Further, the term "swinging" may also be referred to as "rotation".
Further, in FIG. 4, a broken line c is shown. This broken line c indicates that the support member 30 has been moved from the position of the support member 30 in FIG. 4(A) in the direction in which the wiping member 22 comes into contact with the nozzle surface 101a, as shown in FIG. 4(B). It is used for.

The method for making the wiping member 22 swingable can be selected as appropriate; for example, as shown in the figure, a spring 34 may be used. As a result, the wiping member 22 swings with the wiping direction (for example, the Y-axis direction) as the rotation axis, and comes into contact with the nozzle surface 101a. However, the method of making it swingable is not limited to the method of using the spring 34.

Another example is shown in FIG. FIG. 5(A) is a schematic diagram showing a state in which the wiping member 22 is not in contact with the nozzle surface 101a, and FIG. 5(B) is a schematic diagram showing a state in which the wiping member 22 is in contact with the nozzle surface 101a. It is a diagram.

In the example shown in FIG. 5, a spherical ball member 36 is used. Even in this case, the wiping member 22 can swing with the wiping direction (for example, the Y-axis direction) as the rotation axis, and the wiping member 22 swings and comes into contact with the nozzle surface 101a. It does not have to be a spherical ball member, but may be a cylindrical member or the like. The size of the ball member is not particularly limited and can be changed as appropriate.

The wiping member can be selected as appropriate. In the above example, the wiping member is a member that is movable relative to the nozzle surface and is flexible. Examples of flexible members include wiper blades and the like.
As the wiping member, for example, it is a member that is movable relative to the nozzle surface, and a sheet-like web can be used.

FIG. 6 shows another example of the wiping device. In this example, a sheet-like web 40 is used as the wiping member. For example, wiping is performed by pressing the web 40 against the nozzle surface 101a using the pressing member 42. Although not particularly limited, for example, the pressing member 42 moves up and down in conjunction with the support member 30. The web 40 is unwound and taken up, for example, by an unwinding roller 44 and a take-up roller 46.

Note that the configuration described in the above example is also applicable to this example. For example, even when the web 40 is used, it is possible to swing around the direction of relative movement when wiping the nozzle surface 101a as the axis of rotation. Further, when wiping the nozzle surface 101a, the driving force may be continuously applied in the direction in which the wiping member 22 comes into contact with the nozzle surface 101a.

Aspects of the present invention are, for example, as follows.
<1> A wiping member that can come into contact with a nozzle surface of a liquid ejection head and wipes the nozzle surface by moving relative to the nozzle surface;
wiping member moving means for moving the wiping member in a direction in which the wiping member comes into contact with the nozzle surface or in a direction in which the wiping member moves away from the nozzle surface;
The wiping member moving means includes a drive source and a torque limiter provided between the drive source and the wiping member,
The wiping device is characterized in that the torque limiter cuts off the driving force to the wiping member when a torque exceeding a predetermined value is generated when the wiping member comes into contact with the nozzle surface.
<2> The wiping device according to <1>, wherein the contact pressure of the wiping member against the nozzle surface is determined by an upper limit value of torque transmitted from the torque limiter to the wiping member.
<3> The wiping member moving means continues to apply a driving force in a direction in which the wiping member comes into contact with the nozzle surface when the wiping member moves relative to the nozzle surface to wipe the nozzle surface. The wiping device according to <1> or <2>, characterized by:
<4> The wiping device according to any one of <1> to <3>, wherein the wiping member is swingable about a rotation axis in a direction of relative movement when wiping the nozzle surface.
<5> Any one of <1> to <4>, wherein the wiping member is a member that is movable relative to the nozzle surface and is a flexible member or a sheet-like web. The wiping device described in Crab.
<6> An image forming apparatus comprising: a liquid ejection head that ejects liquid; and the wiping device according to any one of <1> to <5>.

22 Wiping member 24 Torque limiter 26 Motor 28 Cam 30 Support member 32 Gear 34 Spring 36 Ball member 40 Web 42 Pressing member

Japanese Patent Application Publication No. 2004-138713 Japanese Patent Application Publication No. 2013-173265

Claims (6)

a wiping member that can come into contact with a nozzle surface of a liquid ejection head and wipes the nozzle surface by moving relative to the nozzle surface;
wiping member moving means for moving the wiping member in a direction in which the wiping member comes into contact with the nozzle surface or in a direction in which the wiping member moves away from the nozzle surface;
The wiping member moving means includes a drive source and a torque limiter provided between the drive source and the wiping member,
The wiping device is characterized in that the torque limiter cuts off the driving force to the wiping member when a torque exceeding a predetermined value is generated when the wiping member comes into contact with the nozzle surface. The wiping device according to claim 1, wherein the contact pressure of the wiping member against the nozzle surface is determined by an upper limit value of torque transmitted from the torque limiter to the wiping member. The wiping member moving means is characterized in that when the wiping member moves relative to the nozzle surface to wipe the nozzle surface, the wiping member continues to apply a driving force in a direction in which the wiping member comes into contact with the nozzle surface. The wiping device according to claim 1. The wiping device according to claim 1, wherein the wiping member is swingable about a rotation axis in a direction of relative movement when wiping the nozzle surface. The wiping device according to claim 1, wherein the wiping member is a member that is movable relative to the nozzle surface and is a flexible member or a sheet-like web. An image forming apparatus comprising: a liquid ejection head that ejects liquid; and the wiping device according to claim 1.