JP2023157326A - Liquid discharge device and cap unit - Google Patents

Abstract

To inhibit deformation of a wall part of a cap.SOLUTION: A liquid discharge device according to the disclosure includes: a head having nozzles for discharging a liquid; a cap; a base which holds the cap; an absorber housed in the cap; and an inhibition member which is housed in the cap and disposed on an upper surface of the absorber. The cap has: a bottom part having an insertion hole; and a wall part enclosing a peripheral edge of the bottom part. The wall part is placed in contact with a nozzle surface of the head to cover the nozzle surface. The base has a projection which is inserted into the insertion hole of the cap. The insertion hole of the cap is not provided at an outer peripheral part of the bottom part and is provided at a center part of the bottom part. The projection of the base has a tip part which holds a holding part provided at a center part of the inhibition member.SELECTED DRAWING: Figure 4

Description

The present invention relates to a liquid ejection device and a cap unit.

Patent Document 1 describes a cap unit that caps the lower surface of a head that discharges ink.

Japanese Patent Application Publication No. 2004-216913

When the cap caps the lower surface of the head, the internal space of the cap may be made negative pressure to perform suction from the nozzle. However, when the internal space of the cap is made to have a negative pressure, the peripheral wall portion of the cap may deform, and the members inside the cap may come into contact with the nozzle surface.

An object of the present invention is to suppress deformation of the wall portion of the cap.

The main invention for achieving the above object has a head having a nozzle for discharging liquid, a bottom part having an insertion hole, and a wall part surrounding the periphery of the bottom part, and the wall part is connected to the nozzle of the head. a cap that covers the nozzle surface in contact with a surface; a base that holds the cap and has a protrusion that is inserted into the insertion hole of the cap; an absorbent material that is accommodated in the cap; and an absorbent material that is accommodated in the cap; a suppressing member disposed on the upper surface of the absorbent material, the insertion hole is not provided on the outer periphery of the bottom but is provided in the center of the bottom, and the protrusion is located on the suppressing member. This is a liquid ejecting device that has a tip portion that holds a holding portion provided in the center.

Other features of the present invention will become apparent from the description of this specification.

According to the present invention, deformation of the wall portion of the cap can be suppressed.

FIG. 1 is a schematic explanatory diagram of the external appearance of the liquid ejection device 1. As shown in FIG. 2A and 2B are explanatory diagrams of the configuration of the head unit 40. FIG. 3 is a perspective view of the cap unit 50A. FIG. 4A is a perspective view of the cap unit 50A with the absorbent material 54 and the suppressing member 55 removed. FIG. 4B is an explanatory diagram of a method of holding the suppressing member 55. FIG. 5 is an explanatory diagram of the spring 53 of the cap unit 50A. FIG. 6 is an exploded explanatory view of the cap unit 50A. FIG. 7A is an explanatory diagram of the cap unit 50A of the first comparative example. FIG. 7B is an explanatory diagram of the suppressing member 55 of the first comparative example. FIG. 8A is an explanatory diagram of the shape of the cap 51 of the first comparative example. FIG. 8B is an explanatory diagram of the shape of the cap 51 of the second comparative example.

===Embodiment===
<Basic configuration>
FIG. 1 is a schematic explanatory diagram of the external appearance of the liquid ejection device 1. As shown in FIG.

In the following description, the moving direction of the carriage 21 may be referred to as a "scanning direction." Further, the moving direction of the medium M may be referred to as a "conveyance direction," the supply side of the medium M may be referred to as "upstream (upstream side)," and the discharge side of medium M may be referred to as "downstream (downstream side)." The direction perpendicular to the nozzle surface 42 of the head 41 (see FIG. 2B) is called the "vertical direction," and the side of the head 41 viewed from the medium M is sometimes called the "top" and the opposite side is sometimes called the "bottom." . Note that the vertical direction is a direction perpendicular to the scanning direction and the conveyance direction.

The liquid ejecting device 1 is a device that ejects liquid onto a medium M (printing paper, printing film, etc.). Here, the liquid ejection device 1 is a device (inkjet printer) that prints an image on a medium M. However, the liquid ejecting device 1 may not be a device that prints an image on the medium M as long as it is a device that ejects liquid from the head 41. The liquid ejection device 1 includes a carriage unit 20, a transport unit 30, a head unit 40, and a cap mechanism 50.

The carriage unit 20 is a unit that moves the carriage 21 in the scanning direction. The carriage unit 20 includes a carriage 21 and a motor (not shown) for moving the carriage 21 in the scanning direction. The carriage 21 is a member that reciprocates in the scanning direction, and has a head 41 (described later) mounted thereon. The carriage 21 may be moved to the end of the movement range in the scanning direction and placed on standby. The position where the carriage 21 is placed on standby is sometimes referred to as a "home position." A cap mechanism 50 is arranged at the home position.

The transport unit 30 is a unit that transports the medium M in the transport direction. The medium M to be conveyed may be a long print medium such as a roll paper, or a cut sheet of paper. Further, the medium M is not limited to paper, but may also be a film, cloth, or the like. The conveyance unit 30 includes, for example, a conveyance roller 31 and a motor (not shown) that drives the conveyance roller 31. The conveyance roller 31 is a member that conveys the medium M in the conveyance direction by rotating. Note that the transport unit 30 is not limited to a configuration using the transport rollers 31. For example, the transport unit 30 may be configured to have a transport table (flat bed) and transport the medium M in the transport direction by moving the transport table.

2A and 2B are explanatory diagrams of the configuration of the head unit 40.

The head unit 40 is a unit for ejecting liquid onto the medium M. The head unit 40 has a head 41. Although the head unit 40 has one head 41 here, it may have a plurality of heads 41. The head 41 has a plurality of nozzles 45 that eject liquid. The liquid here is ink. Ink is a liquid for forming dots on the medium M that constitute an image. However, the liquid ejected from the head 41 is not limited to ink, and may be, for example, a processing liquid. The head 41 has a plurality of nozzle rows 44. The plurality of nozzle rows 44 are arranged side by side in the scanning direction. Each nozzle row 44 is composed of a plurality of nozzles 45 lined up in the transport direction. The nozzle 45 has an opening at the nozzle surface 42 (lower surface) of the head 41, and liquid is ejected from the opening.

The head 41 is arranged on the lower surface of the carriage 21. When the carriage 21 moves in the scanning direction, the head 41 also moves in the scanning direction. When the carriage 21 is moved to the home position, the head 41 can be capped by the capping mechanism 50.

The cap mechanism 50 is a mechanism for covering the nozzle surface 42 (lower surface) of the head 41. Covering the nozzle surface 42 of the head 41 is sometimes called "capping." The cap mechanism 50 is placed at the home position (see FIG. 1). The cap mechanism 50 includes a cap unit 50A (described later; see FIG. 3) that covers the nozzle surface 42 of the head 41, a cap moving mechanism (not shown) that moves the cap unit 50A in the vertical direction, and a cap 51 (see the dotted line in FIG. 2B). (see) and a pump (not shown) that makes the inside of the tank a negative pressure. When the carriage 21 moves to the home position, a cap moving mechanism (not shown) causes the cap unit 50A to approach the head 41, so that the cap unit 50A covers the nozzle surface 42 of the head 41.

FIG. 3 is a perspective view of the cap unit 50A. FIG. 4A is a perspective view of the cap unit 50A with the absorbent material 54 and the suppressing member 55 removed. FIG. 4B is an explanatory diagram of a method of holding the suppressing member 55. FIG. 5 is an explanatory diagram of the spring 53 of the cap unit 50A. FIG. 6 is an exploded explanatory view of the cap unit 50A.

The cap unit 50A is a structure for covering the nozzle surface 42 of the head 41 with a cap 51. The cap unit 50A includes a cap 51, an absorbent material 54, a suppressing member 55, a base 52, a spring 53, and a case 56.

The cap 51 is a member that covers the nozzle surface 42 of the head 41. The cap 51 is configured to have a concave shape so that the cap 51 does not come into contact with the nozzle 45 when the cap 51 covers the nozzle surface 42. The cap 51 is made of rubber and is deformable. Since the cap 51 is made of flexible rubber, the cap 51 can easily come into close contact with the nozzle surface 42. The cap 51 has a bottom portion 511 and a wall portion 512, and the bottom portion 511 and the wall portion 512 constitute a housing portion 513 (accommodation space).

The bottom portion 511 is a portion that constitutes the bottom of the cap 51. The bottom portion 511 is a rectangular plate-shaped portion that is perpendicular to the up-down direction. The bottom portion 511 is arranged substantially parallel to the nozzle surface 42 with a gap between the bottom portions 511 and the nozzle surface 42 when the cap 51 covers the nozzle surface 42 . The bottom portion 511 also functions as a support portion that supports the absorbent material 54. The bottom portion 511 has a suction hole 511A and an insertion hole 511B. The suction hole 511A is a through hole that communicates with a pump (not shown) to make the internal space of the cap 51 a negative pressure. The insertion hole 511B is a through hole into which a protrusion 521B (described later) of the base 52 is inserted. Here, the insertion hole 511B is arranged at the center of the bottom 511 (corresponding to the intersection of diagonals of the rectangular bottom 511). Note that the arrangement of the insertion hole 511B will be described later. The insertion hole 511B has a recess that can accommodate the packing 514. The packing 514 is a member that closes the gap between the insertion hole 511B and the protrusion 521B. However, the packing 514 may not be provided.

The wall portion 512 is a portion that constitutes a side surface of the cap 51. The wall portion 512 is a wall-shaped portion rising from the periphery of the rectangular bottom portion 511 . The wall portion 512 is configured to be substantially parallel to the vertical direction. By configuring the wall portion 512 to surround the periphery of the rectangular bottom portion 511, the concave cap 51 is configured, and a housing portion 513 (accommodation space) is configured. The upper edge of the wall portion 512 becomes a contact portion that comes into contact with the nozzle surface 42 of the head 41. The upper edge of the wall portion 512 contacts the nozzle surface 42 of the head 41 so as to surround the nozzle row 44 of the head 41 when the cap 51 covers the nozzle surface 42 .

The wall portion 512 has a hook portion 512A (see the enlarged view of FIG. 3). The hook portion 512A is a claw-shaped portion that protrudes inward from the inner wall surface of the wall portion 512. The hook portion 512A is a portion on which the suppressing member 55 is hooked. Since the wall portion 512 has the hook portion 512A, it is possible to suppress the suppression member 55 from coming off.

The accommodating portion 513 is a portion that accommodates the absorbent material 54 and the suppressing member 55. The absorbent material 54 and the suppressing member 55 are housed in a space defined by the bottom portion 511 and the wall portion 512 (inner space of the cap 51). As shown in FIGS. 4A and 4B, the absorbent material 54 and the suppressing member 55 are accommodated in the accommodating portion 513 so that the suppressing member 55 is above the absorbent material 54. Note that, as shown in FIG. 2, when the absorbent material 54 and the suppressing member 55 are accommodated in the accommodating portion 513, the wall portion 512 protrudes above the suppressing member 55. This suppresses the suppression member 55 (and the protrusion 521B) from coming into contact with the nozzle surface 42 of the head 41 when the cap 51 covers the nozzle surface 42 .

The absorbent material 54 is a member that absorbs liquid. The absorbent material 54 is a plate-shaped member perpendicular to the up-down direction. Here, the absorbent material 54 is a member made of a porous sintered body. However, the absorbent material 54 is not limited to a porous sintered body, and may be a porous body made of a foam such as a sponge. The absorbent material 54 has an insertion hole 54A through which a protrusion 521B (described later) of the base 52 is inserted. Here, the insertion hole 54A is arranged at the center of the absorbent material 54.

The suppressing member 55 is a member that suppresses the absorbent material 54. The suppressing member 55 is arranged on the upper surface of the absorbent material 54. The suppressing member 55 is a member perpendicular to the up-down direction. Here, the suppressing member 55 is made of a wire mesh. However, the suppressing member 55 does not need to be made of metal or a net-like member.

The suppressing member 55 includes a holding portion 551, a frame portion 552, and a rib 553.

The holding portion 551 is a portion held by the base 52 (specifically, the tip of the protrusion 521B). The holding part 551 is arranged at the center of the suppressing member 55. Here, the holding portion 551 has an insertion hole 551A through which a protrusion 521B (described later) of the base 52 is inserted. As shown in FIG. 4B, by thermally caulking the tip of the protrusion 521B inserted into the insertion hole 551A of the holding part 551, the suppressing member 55 is restrained by the tip of the protrusion 521B, and the suppressing member 55 is held on the base 52. This prevents the suppressing member 55 from coming off. However, the holding part 551 is not limited to the form having the insertion hole 551A, but may have a form as long as it is held by the protrusion 521B (for example, as described later, the holding part 551 may have a pin. ).

The frame portion 552 is a portion that constitutes the periphery of the suppressing member 55. The frame portion 552 constitutes the periphery of the four sides of the rectangular suppressing member 55. When the suppressing member 55 is accommodated in the accommodating portion 513 of the cap 51, the frame portion 552 is arranged along the inner wall surface of the wall portion 512 of the cap 51.

The ribs 553 are parts that reinforce the suppressing member 55. Here, the rib 553 connects the holding portion 551 and the frame portion 552. Note that when there are a plurality of holding parts 551, the ribs 553 may connect the holding parts 551 to each other. The ribs 553 are connected to the center of each side of the frame portion 552. Thereby, the dose to the rib 553 can be suppressed. As shown in the enlarged view of FIG. 3, it is desirable that the hook portion 512A hooks a portion of the frame portion 552 that is connected to the rib 553. Thereby, the suppressing member 55 can be stably held.

The base 52 is a member that holds the cap 51. The base 52 is made of a harder material than the cap 51, and is made of resin here. The base 52 has a cap accommodating portion 521. The cap accommodating portion 521 is a concave portion that accommodates the cap 51. Since the bottom portion 511 of the cap 51 is rectangular, the bottom surface of the cap accommodating portion 521 is also rectangular. As shown in FIG. 5, the base 52 is pressed upward by a spring 53. The cap accommodating portion 521 has a suction port 521A and a protrusion 521B.

The suction port 521A is a part that is inserted into the suction hole 511A of the cap 51, and is a part that communicates with a pump (not shown) to make the internal space of the cap 51 a negative pressure.

The protrusion 521B is a portion that projects upward and is a portion that holds the suppressing member 55. The protrusion 521B is inserted through the cap 51, the absorbent material 54, and the suppressing member 55. The protrusion 521B has a tip portion that holds the holding portion 551 of the suppressing member 55. Here, as shown in FIG. 4B, the tip of the protrusion 521B protrudes above the suppressing member 55 (holding part 551), and the tip of the protrusion 521B protruding above the suppressing member 55 is thermally caulked. As a result, the suppressing member 55 is held on the base 52. The tip of the protrusion 521B shown in FIG. 4B has a claw part 522 that protrudes outward from the circumferential surface of the protrusion 521B, and the claw part 522 holds the holding part 551 by catching on the holding part 551 of the suppressing member 55. are doing. The claw portion 522 shown in FIG. 4B is formed by thermally caulking the tip of the protrusion 521B, and is formed to protrude from the entire circumferential surface of the protrusion 521B. However, the claw portion 522 does not need to protrude from the entire circumferential surface of the protrusion 521B. For example, the claw portion 522 may protrude from a part of the circumferential surface of the protrusion 521B (in other words, the tip of the protrusion 521B (may be configured in an L-shape (hook shape)). Further, the tip portion of the protrusion 521 does not need to have the claw portion 522. For example, a concave hole is formed at the tip of the protrusion 521B, the holding part 551 of the suppressing member 55 has a pin protruding downward instead of the insertion hole 551A, and the holding part 551 is formed in the hole of the protrusion 521B. The tip of the protrusion 521B may hold the suppressing member 55 by engaging the pin of the protrusion 521B. Further, the tip of the protrusion 521B only needs to be held so that the suppressing member 55 does not come off, and the suppressing member 55 does not need to be fixed. For example, the distal end of the protrusion 521B may hold the suppressing member 55 while allowing the suppressing member 55 to move in a direction perpendicular to the up-down direction.

In order to create a negative pressure in the internal space of the cap 51, the gap between the protrusion 521B and the cap 51 is closed with the protrusion 521B inserted into the insertion hole 511B of the cap 51. By closing the gap between the protrusion 521B and the cap 51, the protrusion 521B and the cap 51 come into close contact with each other, so that the cap 51 is restrained with respect to the base 52 at the position of the insertion hole 511B. .

The spring 53 is a member that presses the base 52 (see FIG. 5). When the cap 51 covers the nozzle surface 42, the spring 53 is compressed and the base 52 moves downward with respect to the case 56. When the spring 53 presses the base 52, the cap 51 can be pressed against the nozzle surface 42 with a predetermined pressing force. Further, since the cap 51 pressed by the spring 53 is brought into contact with the nozzle surface 42, even if the cap 51 is tilted with respect to the nozzle surface 42 before contact, the cap 51 can be brought into close contact with the nozzle surface 42. .

The case 56 is a member that holds the base 52. The case 56 holds the base 52 so as to prevent the base 52, which is pressed upward, from coming off. When the cap 51 covers the nozzle surface 42, the base 52 moves downward with respect to the case 56 as the cap 51 is pushed by the nozzle surface 42. Case 56 has an upper case 56A and a lower case 56B. The upper case 56A is a member that constitutes the upper part of the case 56, and prevents the base 52 from coming off. The lower case 56B is a member that constitutes the lower part of the case 56, and is a member that fixes the upper case 56A.

<About deformation of cap 51>
In this embodiment, the insertion hole 511B of the cap 51 is not provided at the outer circumference of the bottom 511, but is provided at the center of the bottom 511. Here, as shown in FIG. 6, the insertion hole 511B of the cap 51 is provided only in the center of the bottom portion 511. Thereby, as will be described later, deformation of the wall portion 512 of the cap 51 in the height direction can be suppressed.

Note that the "center" of a rectangular member (for example, the bottom portion 511) corresponds to the position of the intersection of diagonals of the rectangular member. Further, the "center portion" of a rectangular member corresponds to a region closer to the center of the member (the position of the intersection of diagonals) than the outer edge of the member. Further, the "outer peripheral portion" of a rectangular member corresponds to a region closer to the outer edge of the member than the center of the member. The outer periphery is an area surrounding the outside of the center.

In the present embodiment, the placement of the insertion hole 511B of the cap 51 is not limited to the center of the bottom portion 511, but may be in the center of the bottom portion 511, and the insertion hole 511B may be placed at a position slightly shifted from the center. Also good. Further, the number of insertion holes 511B of the cap 51 is not limited to one, but may be two or more.

Further, the protrusion 521B of the base 52 is not provided on the outer circumferential portion of the cap accommodating portion 521, but is provided at the center portion of the cap accommodating portion 521. The protrusion 521B of the base 52 is provided at a position corresponding to the insertion hole 511B of the cap 51 (in other words, the insertion hole 511B of the cap 51 is provided at a position corresponding to the protrusion 521B of the base 52). Here, as shown in FIG. 6, the protrusion 521B is provided only at the center of the cap accommodating part 521 (at the intersection of diagonal lines of the rectangular cap accommodating part 521). Note that the arrangement of the protrusion 521B is not limited to the center of the cap accommodating portion 521, but may be located at the center of the cap accommodating portion 521, and the protrusion 521B may be arranged at a position slightly shifted from the center. Furthermore, the number of protrusions 521B is not limited to one, but may be two or more.

The insertion hole 54A of the absorbent material 54 is provided in the center of the absorbent material 54. The insertion hole 54A of the absorbent material 54 is provided at a position corresponding to the insertion hole 511B of the cap 51 and the protrusion 521B of the base 52. Here, as shown in FIG. 6, the insertion hole 54A of the absorbent material 54 is provided only in the center of the absorbent material 54. Note that an insertion hole 54A may be provided in the outer peripheral portion of the absorbent material 54. However, the protrusion 521B is not inserted into the insertion hole 54A on the outer periphery of the absorbent material 54.
Similarly, the holding portion 551 (and the insertion hole 551A) of the suppressing member 55 is provided at the center of the suppressing member 55. The holding portion 551 of the suppressing member 55 is provided at a position corresponding to the insertion hole 511B of the cap 51 and the protrusion 521B of the base 52. Here, as shown in FIG. 6, the holding portion 551 of the suppressing member 55 is provided only at the center of the suppressing member 55. Note that an insertion hole 551A may be provided in the outer peripheral portion of the suppressing member 55. However, the protrusion 521B is not inserted into the insertion hole 551A on the outer circumference of the suppressing member 55.

FIG. 7A is an explanatory diagram of the cap unit 50A of the first comparative example. FIG. 7B is an explanatory diagram of the suppressing member 55 of the first comparative example. The insertion hole 511B of the cap 51 of the first comparative example is provided not only at the center of the bottom 511 but also at the outer periphery of the bottom 511 (an area close to the inner wall surface of the wall 512). Further, the protrusion 521B of the base 52 is provided not only at the center portion of the cap accommodating portion 521 but also at the outer peripheral portion of the cap accommodating portion 521. The holding portion 551 of the suppressing member 55 is provided not only at the central portion of the suppressing member 55 but also at the outer peripheral portion of the suppressing member 55 (an area close to the frame portion 552). The plurality of protrusions 521B of the base 52 are inserted into the respective insertion holes 551A of the cap 51, the absorbent material 54, and the suppressing member 55, and the distal ends of the protrusions 521B are thermally caulked. are held in holding portions 551, respectively.

FIG. 8A is an explanatory diagram of the shape of the cap 51 of the first comparative example. The upper part of the figure is a graph of the measurement results of the shape of the cap 51 before the inside of the cap 51 is made into a negative pressure. The lower part of the figure is a graph of the measurement results of the shape of the cap 51 when the inside of the cap 51 is under negative pressure (at the time of negative pressure). The horizontal axis of the graph indicates the position in the vertical direction. The vertical axis of the graph indicates the position of the cap 51 in the vertical direction. The position of the peak in the graph (the position of the triangle mark in the figure) indicates the position of the end of the wall portion 512 of the cap 51. Note that when the inside of the cap 51 is made to have a negative pressure, the end of the wall portion 512 of the cap 51 is in contact with the nozzle surface 42 of the head 41.

FIG. 8B is an explanatory diagram of the shape of the cap 51 of the second comparative example. Similar to FIG. 8A, the upper diagram in the figure is a graph of the measurement results of the shape of the cap 51 before the inside of the cap 51 is made into a negative pressure. The lower part of the figure is a graph of the measurement results of the shape of the cap 51 under negative pressure. In the second comparative example, the shape of a single cap 51 was measured. Therefore, in the second comparative example, the absorbent material 54 and the suppressing member 55 are not arranged in the cap 51, and the protrusion 521B is not inserted into the insertion hole 511B of the cap 51. That is, in the second comparative example, the bottom portion 511 of the cap 51 is not restrained by the protrusion 521B.

As shown in FIGS. 8A and 8B, the peaks in the lower graph are lower in height than the peaks in the upper graph. That is, in both the first comparative example and the second comparative example, the wall portion 512 of the cap 51 becomes lower when the pressure is negative. This is because when the inside of the cap 51 becomes negative pressure, the wall portion 512 of the cap 51 receives a force in the direction of the nozzle surface 42, and the wall portion 512 deforms so as to collapse in the vertical direction. Note that if the wall portion 512 is lowered during negative pressure, there is a risk that the suppressing member 55 and the protrusion 521B may come into contact with the nozzle surface 42 of the head 41.

Further, as shown in FIG. 8A, the spread of the peak in the graph in the lower figure (width in the left-right direction in the figure) is wider than in the upper figure. That is, in the first comparative example, when the inside of the cap 51 is made to have a negative pressure, the wall portion 512 of the cap 51 deforms in a direction in which it becomes thicker (a direction perpendicular to the up-down direction; a left-right direction in the drawing). This is because the internal pressure of the cap 51 is made negative after the wall 512 of the cap 51 is brought into contact with the nozzle surface 42. This is thought to be due to the deformation in which the end of the tube is pulled inward. In the first comparative example, when the inside of the cap 51 is made negative pressure, the wall portion 512 not only deforms in the vertical direction but also deforms in the thickness direction. Since the vertical deformation (deformation due to the Poisson effect) accompanying the directional deformation is added, the vertical deformation of the wall portion 512 becomes relatively large.

In the second comparative example, the wall portion 512 is prevented from deforming to become thicker than in the first comparative example. This is considered to be because, in the second comparative example, when the inside of the cap 51 is made negative pressure, the bottom portion 511 of the cap 51 deforms upward. That is, as the bottom portion 511 of the cap 51 is displaced upward, the wall portion 512 of the cap 51 is deformed so as to fall outward, so that the end portion of the wall portion 512 of the cap 51 comes into contact with the nozzle surface 42. It is considered that this is because the wall portion 512 is prevented from deforming so as to be drawn inward in this state, and the wall portion 512 is prevented from deforming so as to become thicker.

Furthermore, in the second comparative example, vertical deformation of the wall portion 512 is suppressed compared to the first comparative example. In other words, in the second comparative example, the height of the wall portion 512 at the time of negative pressure is maintained (reduction in the height of the wall portion 512 is suppressed) compared to the first comparative example. This is because in the second comparative example, the deformation in the thickness direction of the wall portion 512 can be suppressed compared to the first comparative example (as described above). This is thought to be due to the suppression of deformation (deformation caused by effects).

On the other hand, in the second comparative example, since the bottom portion 511 of the cap 51 is largely deformed upward, there is a risk that the suppressing member 55 and the absorbent material 54 housed in the cap 51 may come into contact with the nozzle surface 42 . Note that in the first comparative example, deformation of the bottom portion 511 of the cap 51 is suppressed compared to the second comparative example. This is because in the first comparative example, the protrusion 521B is inserted through the cap 51 and the suppressing member 55, so that the cap 51 and the suppressing member 55 are restrained with respect to the base 52. However, as described above, in the first comparative example, there is a risk that the suppressing member 55 and the protrusion 521B may come into contact with the nozzle surface 42 due to the wall portion 512 being lowered during negative pressure.

Therefore, in this embodiment, as already explained, the insertion hole 511B of the cap 51 is not provided at the outer circumferential portion of the bottom portion 511, but is provided at the center portion of the bottom portion 511. Further, the tip of the protrusion 521B of the base 52 is held by a holding part 551 provided at the center of the suppressing member 55. Accordingly, in this embodiment, the protrusion 521B of the base 52 is inserted into the insertion hole 511B of the cap 51, so that the center portion of the cap 51 is restrained with respect to the base 52, and the center portion of the suppressing member 55 is 52, it is possible to suppress the suppression member 55 from coming into contact with the nozzle surface 42 compared to the second comparative example. Further, in this embodiment, since the insertion hole 511B is not provided on the outer circumference of the bottom part 511, the outer circumference of the cap 51 is not restrained with respect to the base 52, so that the outer circumference of the bottom part 511 is As the bottom portion 511 deforms, the wall portion 512 of the cap 51 can be deformed so as to fall down toward the outside. As a result, the wall portion 512 is It is possible to prevent the wall portion 512 from deforming to become thicker (reducing the height of the wall portion 512 due to the Poisson effect), and to suppress vertical deformation of the wall portion 512.

===Summary===
The liquid ejection device 1 (or cap unit 50A) includes a head 41, a cap 51, a base 52, an absorbent 54, and a suppressing member 55. The cap 51 has a bottom portion 511 having an insertion hole 511B and a wall portion 512 surrounding the periphery of the bottom portion 511, and the wall portion 512 is brought into contact with the nozzle surface 42 of the head 41 to cover the nozzle surface 42. . The base 52 has a protrusion 521B that is inserted into the insertion hole 511B of the cap 51. Further, the absorbent material 54 is accommodated in the cap, and the suppressing member 55 is accommodated in the cap while being disposed on the upper surface of the absorbent material 54. In this embodiment, the insertion hole 511B of the cap 51 is not provided on the outer periphery of the bottom 511 but is provided in the center of the bottom 511, and the protrusion 521B of the base 52 is provided in the center of the suppressing member 55. It has a tip portion that holds a holding portion 551. Thereby, deformation of the wall portion 512 of the cap 51 can be suppressed while suppressing the suppression member 55 from coming into contact with the nozzle surface 42 .

As shown in the enlarged view of FIG. 3, a hook portion 512A for hooking the peripheral edge (frame portion 552) of the suppressing member 55 is provided on the inner wall surface of the wall portion 512. Since the upper edge of the wall portion 512 is located above the hook portion 512A, when the outer peripheral portion of the bottom portion 511 deforms upward during negative pressure, the portion of the wall portion 512 above the hook portion 512A deforms around the hook portion 512A. Since the wall portion 512 is easily deformed so as to fall down toward the outside, it is possible to suppress the wall portion 512 from deforming so as to become thicker, and the vertical deformation of the wall portion 512 can be suppressed. However, a hook portion 512A may be provided on the inner wall surface of the wall portion 512.

It is desirable that the outer peripheral portion of the bottom portion 511 deforms toward the nozzle surface 42 when the inside of the cap 51 becomes negative pressure with the cap 51 covering the nozzle surface 42 . This allows the wall portion 512 of the cap 51 to deform so as to fall outward as the outer peripheral portion of the bottom portion 511 deforms upward during negative pressure, and as a result, the wall portion 512 becomes thicker. Thus, deformation of the wall portion 512 in the vertical direction can be suppressed.

===Other embodiments===
The above embodiments are presented as examples and do not limit the scope of the invention. The above configurations can be implemented in appropriate combinations, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. The above-described embodiments and their modifications are included within the scope and gist of the invention as well as within the scope of the invention described in the claims and its equivalents.

1 liquid ejection device,
20 carriage unit, 21 carriage,
30 conveyance unit, 31 conveyance roller,
40 head unit, 41 head,
42 nozzle surface, 44 nozzle row, 45 nozzle,
50 cap mechanism, 50A cap unit,
51 Cap,
511 bottom, 511A suction hole, 511B insertion hole,
512 wall part, 512A hook part,
513 accommodating section, 514 packing,
52 base, 521 cap storage section,
521A Suction port, 521B Projection, 522 Claw portion, 53 Spring,
54 absorbent material, 54A insertion hole,
55 suppressing member, 551 holding part, 551A insertion hole,
552 frame, 553 rib,
56 case, 56A upper case, 56B lower case,
M medium

Claims (4)

a head having a nozzle that discharges liquid;
a cap having a bottom portion having an insertion hole, and a wall portion surrounding the periphery of the bottom portion, the wall portion contacting the nozzle surface of the head to cover the nozzle surface;
a base that holds the cap and has a protrusion that is inserted into the insertion hole of the cap;
an absorbent material housed in the cap;
a suppressing member accommodated in the cap and disposed on the upper surface of the absorbent material;
Equipped with
The insertion hole is not provided on the outer periphery of the bottom, but is provided in the center of the bottom,
The protrusion has a tip portion that holds a holding portion provided at a central portion of the suppressing member.
Liquid discharge device.
The liquid ejection device according to claim 1,
A liquid ejecting device, wherein a hook portion for hooking a peripheral edge of the suppressing member is provided on an inner wall surface of the wall portion.
The liquid ejection device according to claim 1 or 2,
A liquid ejecting device, wherein when the cap covers the nozzle surface and the inside of the cap becomes negative pressure, the outer peripheral portion of the bottom portion deforms toward the nozzle surface.
a cap having a bottom portion and a wall portion surrounding the periphery of the bottom portion, the wall portion contacting the nozzle surface of the head to cover the nozzle surface;
a base holding the cap and having a protrusion;
an absorbent material having an insertion hole through which the protrusion is inserted and accommodated in the accommodation portion of the cap;
a suppressing member accommodated in the accommodating portion of the cap and disposed on the upper surface of the absorbent material;
Equipped with
The protrusion is not provided on the outer periphery of the bottom but is provided in the center of the bottom, and has a tip that holds a holding part provided in the center of the suppressing member.
cap unit.

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