JP2023056112A - Liquid discharge head and liquid discharge device - Google Patents

Abstract

To provide a liquid discharge head that hardly receives a thermal effect in the clogging of a nozzle.SOLUTION: A liquid discharge head includes a nozzle member having a nozzle for discharging liquid, a driving unit for holding a valve body for opening/closing the nozzle, an actuator, and an elastic member for holding the actuator and transmitting the driving force of the actuator to the valve body by elastically deforming by the drive of the actuator, and a storage member for holding the nozzle member and storing the driving unit. A fixing position of the driving unit with respect to the storage member is more on a nozzle side than the holding position by the elastic member at an end part on a side opposite to the nozzle member of the actuator.SELECTED DRAWING: Figure 5

Description

The present invention relates to a liquid ejection head and a liquid ejection apparatus.

In Patent Document 1, a discharge liquid is pressurized and supplied to a cavity communicating with a nozzle, the nozzle can be closed by a pin, the pin can be separated from the nozzle by an actuator, and the actuator is controlled by a control device. With this configuration, a droplet discharge head is disclosed in which the discharge liquid that is pressurized and supplied is discharged as droplets from the nozzles only while the pins are separated from the nozzles.

In an actuator having a property of contracting due to heat, the actuator itself may contract due to the heat generated when it is driven, in which case the nozzle will be incompletely blocked.

The present invention holds a nozzle member having a nozzle for discharging a liquid, a valve body for opening and closing the nozzle, an actuator, and the actuator. a drive unit having an elastic member that transmits to the nozzle member, and a housing member that holds the nozzle member and houses the drive unit;
wherein the position where the drive unit is fixed to the housing member is closer to the nozzle than the holding position by the elastic member at the end of the actuator opposite to the nozzle member. characterized by

According to the present invention, it is possible to provide a liquid ejection head that is less likely to be affected by heat when nozzles are clogged.

1 is an overall perspective view of a liquid ejection head according to an embodiment of the present invention; FIG. 1 is an overall cross-sectional view of a liquid ejection head according to an embodiment of the present invention; FIG. FIG. 4 is an explanatory diagram of a single drive unit according to the embodiment of the present invention; Schematic enlarged view of the tip of the needle valve Explanatory drawing of a fixed position. FIG. 5 is an explanatory diagram showing a modified example of the drive unit according to the embodiment of the present invention; 1 is an overall perspective view of a liquid ejection device according to an embodiment of the present invention; FIG. FIG. 8 is an overall perspective view of a carriage of the liquid ejection device of FIG. 7; FIG. 4 is a schematic configuration diagram showing another example of the liquid ejection device according to the embodiment of the present invention; FIG. 10 is a partially enlarged view of FIG. 9; Explanatory drawing which shows the application example of this invention. Explanatory drawing which shows the application example of this invention. Explanatory drawing which shows the application example of this invention. Explanatory drawing which shows the application example of this invention.

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

FIG. 1 is an overall perspective view of a liquid ejection head according to an embodiment of the invention.

A liquid ejection head (hereinafter referred to as head) 300 mainly includes a housing 310 , a connector 350 , a liquid supply port 311 and a liquid recovery port 313 . The housing 310 is made of metal material or resin material. The connector 350 is a terminal for transmitting electric signals such as drive signals for ejecting liquid, and is provided on the upper portion of the housing 310 in this embodiment. A liquid supply port 311 and a liquid recovery port 313 are located on the left and right sides of the housing 310, and the liquid supply port 311 supplies liquid into the head. A liquid recovery port 313 also drains liquid from the head.

FIG. 2 is an overall cross-sectional view (a cross-sectional view taken along the line AA in FIG. 1) of the liquid ejection head according to the embodiment of the present invention.

The housing 310 has a connector 350 for transmitting electrical signals on its upper portion, and holds a nozzle plate 301 having nozzles 302 for ejecting liquid on its lower portion. Further, the housing 310 has a channel 312 that sends the liquid from the liquid supply port 311 to the liquid recovery port 313 side through the nozzle plate 301 . Here, the nozzle plate 301 is an example of a "nozzle member".

Furthermore, the housing 310 accommodates a drive unit 330 between the liquid supply port 311 and the liquid recovery port 313 for discharging the liquid in the flow path 312 from the nozzle 302 . Although details of the drive unit 330 will be described later, the drive unit 330 generally includes a needle valve 331 , a piezoelectric element 332 and a plate spring frame 333 . The leaf spring frame 333 holds the piezoelectric element 332 and is elastically deformed by driving the piezoelectric element 332 to transmit the driving force of the piezoelectric element 332 to the needle valve 331 . The needle valve 331 receives elastic deformation of the plate spring frame 333 to open and close the nozzle 302 . Here, the needle valve 331 constituting the drive unit 330 is an example of a "valve", the piezoelectric element 332 is an example of an "actuator", and the plate spring frame 333 is an example of an "elastic member". Also, the housing 310 is an example of the "accommodating member".

The number of drive units 330 matches the number of nozzles 302, and the present embodiment exemplifies a configuration including eight drive units 330 corresponding to eight nozzles 302 arranged in one row. The number and arrangement of nozzles 302 and drive units 330 are not limited to those described above. For example, the number of nozzles 302 and drive units 330 may be nine or more, or one rather than multiple. Also, the nozzles 302 and the drive units 330 may be arranged in multiple rows rather than in one row.

In the above configuration, as for the flow of liquid, the liquid supply port 311 takes in pressurized liquid from the outside, sends the liquid in the direction of the arrow a1, and supplies the liquid to the flow path 312 . The channel 312 sends the liquid from the liquid supply port 311 in the arrow a2 direction. The liquid recovery port 313 discharges the liquid that has not been discharged from the nozzles 302 arranged along the flow path 312 in the direction of the arrow a3.

When the needle valve 331 is displaced upward in the figure, the nozzle 302 that was closed by the needle valve 331 is opened, and the liquid flowing through the flow path 312 is discharged from the nozzle. Discharge from 302 . When the piezoelectric element 332 is actuated and the needle valve 331 is displaced downward, the tip of the needle valve 331 comes into contact with the nozzle 302 and the nozzle 302 is closed. It should be noted that while the liquid is being ejected from the nozzles 302, in order not to lower the ejection efficiency from the nozzles 302, the liquid may be temporarily not discharged from the liquid recovery port 313. FIG. Next, the configuration of drive unit 330 will be described in detail.

FIG. 3 is an explanatory diagram of a single drive unit according to the embodiment of the present invention.

The drive unit 330 includes a needle valve 331 , a piezoelectric element 332 and a plate spring frame 333 . Nozzle plate 301 is joined to housing 310 . Also, the channel 312 is a common channel for the plurality of drive units 330 provided in the housing 310 .

As shown in FIG. 4 , the tip of the needle valve 331 faces the nozzle 302 provided on the nozzle plate 301 , and closes the nozzle 302 when the tip of the needle valve 331 comes into contact with the nozzle plate 301 . As shown in FIG. 3, the needle valve 331 may be provided with an elastic body 331a at its tip so as to close the nozzle 302 more reliably.

Housing 310 supports needle valve 331 via bearing 321 , and further, seal member 315 such as an O-ring is mounted between bearing 321 and needle valve 331 . A leaf spring frame 333 is arranged in a space 322 formed inside the housing 310 . The plate spring frame 333 includes a needle valve holding portion 333a, a frame portion 333b, an expandable portion 333c, a space 333d, and piezoelectric element holding portions 333e and 333f. The needle valve holding portion 333 a holds the rear end portion of the needle valve 331 . The frame portion 333b is made of, for example, a metal plate, and has a space 333d in the center. The expansion/contraction portion 333c is a plate spring formed integrally with a portion of the frame portion 333b, and this portion is expandable/contractable.

A space 333 d of the plate spring frame 333 forms an installation space for the piezoelectric element 332 . The piezoelectric element holding portion 333e protrudes toward the space 333d from the rear side of the needle valve holding portion 333a of the frame portion 333b. It protrudes towards 333d.

When the piezoelectric element 332 is attached to the plate spring frame 333 configured as described above, the plate spring frame 333 is slightly extended by utilizing the elastic deformation of the expandable portion 333c to widen the space 333d. After the piezoelectric element 332 is inserted into the expanded space 333d, the leaf spring frame 333 is released from the expanded state. As a result, the plate spring frame 333 holds both ends of the piezoelectric element 332 in the longitudinal direction by sandwiching the piezoelectric element 332 between the piezoelectric element holding portions 333e and 333f due to the restoring force of the elastic portion 333c. do. Therefore, in the default state in which the piezoelectric element 332 is inserted into the space 333d, the stretchable portion 333c is slightly stretched.

In the present embodiment, the leaf spring frame 333 as an elastic member includes the needle valve holding portion 333a, the frame portion 333b, the expandable portion 333c, and the piezoelectric element holding portions 333e and 333f as an integral member. A part of these parts may be configured by a separate member. For example, the elastic portion 333c may be configured with a spring or the like, and the spring may be attached to the frame portion 333b.

The drive unit 330 is attached to the housing 310 by, for example, fastening a screw hole 310a provided in the housing 310 and a screw hole 333g provided in the leaf spring frame 333 with a screw 310b. The screw hole 333g provided in the plate spring frame 333 is formed with a depth that does not penetrate the plate spring frame 333. As shown in FIG. The screw hole 333g may be a through hole, but in that case, the screw 310b having a length not reaching the piezoelectric element 332 is used. Also, the number of fastening points is not limited to one. For example, a similar screw hole may be provided on the right side in the drawing, and the housing 310 and the drive unit 330 may be fastened from the left and right. Fastening portions by these screw holes 310a and 333g and screws 310b form a fixing point 314, which is provided on line B (the fixing point 314 will be described later in detail).

With the above configuration, the needle valve 331 and the piezoelectric element 332 are arranged coaxially with the leaf spring frame 333 interposed therebetween, that is, arranged in series in the liquid ejection direction. When a voltage is applied to the piezoelectric element 332, the piezoelectric element 332 expands. When the piezoelectric element 332 expands, the expanding/contracting portion 333c of the leaf spring frame 333 elastically deforms to absorb the expansion, and the needle valve holding portion 333a installed at the tip of the piezoelectric element 332 is moved toward the nozzle 302 (lower side in the drawing). ). Thus, the plate spring frame 333 is elastically deformed by driving the piezoelectric element 332 and transmits the driving force of the piezoelectric element 332 to the needle valve 331 . As a result, the tip of the needle valve 331 (the elastic body 331 a in this embodiment) comes into contact with the nozzle 302 to block the nozzle 302 , thereby stopping the discharge from the nozzle 302 of the liquid pressurized and supplied to the channel 312 .

Further, when the voltage application to the piezoelectric element 332 is stopped, the piezoelectric element 332 contracts. When the piezoelectric element 332 contracts, the expansion/contraction part 333c elastically deforms to absorb the contraction, and pulls the needle valve holding part 333a installed at the tip of the piezoelectric element 332 toward the rear end (upward in the figure). As a result, the tip of the needle valve 331 (the elastic body 331 a in this embodiment) is separated from the nozzle 302 to open the nozzle 302 , and the liquid pressurized and supplied to the channel 312 is discharged from the nozzle 302 . Next, the fixed point 314 will be described.

FIG. 5 is a diagram for explaining fixed positions. FIG. 5(a) shows a comparative example, and FIG. 5(b) shows a head structure according to an embodiment of the present invention. It is shown as an abbreviated schematic.

In the comparative example, the fastening position between the housing 310 and the drive unit 330, that is, the fixing point 314 as the fixing position of the drive unit 330 with respect to the housing 310, is positioned near the end of the drive unit 330 opposite to the nozzle plate 301 (line C above), and the length (free length) from the fixed point 314 to the tip of the needle valve 331 is L1.

By the way, some piezoelectric elements 332 have the characteristic that the overall length (longitudinal length) of the piezoelectric element 332 shrinks due to the increase in ambient temperature around the piezoelectric element 332 or the heat generated when the piezoelectric element 332 itself is driven. . Therefore, if the piezoelectric element 332 shrinks due to heat, the expansion amount of the piezoelectric element 332 is insufficient even if a voltage is applied to the piezoelectric element 332, and the tip of the needle valve 331 cannot reach the nozzle 302, closing the nozzle 302. become unable.

The amount of contraction (ΔL) due to heat of the drive unit 330 is proportional to the free length (L) from the fixing point 314 to the tip of the needle valve 331, and the contraction amount tends to increase as the free length increases. Therefore, when the free length is long as in the comparative example, the shrinkage amount (ΔL) due to heat of the drive unit 330 also increases, and the nozzle 302 cannot be closed easily. On the other hand, in order to obtain a head that can handle high-viscosity liquids, a drive unit 330 that can generate a large amount of displacement is necessary, and a long piezoelectric element is effective in realizing such a drive unit 330. be.

Therefore, in this embodiment, as shown in FIG. 5B, the free length L2 from the fixing point 314 to the tip of the needle valve 331 is shortened to suppress the effect of contraction. That is, the fixed point 314 is provided closer to the nozzle plate 301 (on the line B) than in the comparative example, thereby suppressing the contraction amount (ΔL) from the effect of the contraction from the fixed point 314 to the tip of the needle valve 331, thereby Decrease the absolute value of shrinkage.

Specifically, the fixing point 314 is arranged closer to the nozzle 302 than the holding position (for example, position P) of the leaf spring frame 333 at the end of the piezoelectric element 332 opposite to the nozzle plate 301 . The free length L2 from the fixing point 314 to the tip of the needle valve 331 is as short as possible to suppress the effect of contraction. ) It is provided closer to the nozzle 302 than the half (L3/2) of the length L3. Alternatively, the fixing point 314 is provided closer to the nozzle 302 than half (L4/2) of the length L4 in the longitudinal direction (the direction of liquid ejection) of the housing 310 . Here, the longitudinal direction (liquid ejection direction) length L3 of the piezoelectric element 332 is the length of the piezoelectric element 332 when no voltage is applied to the piezoelectric element 332 .

As described above, this embodiment holds the nozzle plate 301 having the nozzles 302 for ejecting liquid, the needle valve 331 for opening and closing the nozzles 302, the piezoelectric elements 332, and the piezoelectric elements 332, and drives the piezoelectric elements 332 to A head 300 comprising a drive unit 330 having a plate spring frame 333 that elastically deforms to transmit the driving force of a piezoelectric element 332 to a needle valve 331, and a housing 310 that holds the nozzle plate 301 and accommodates the drive unit 330. The fixing point 314 of the drive unit 330 with respect to the housing 310 is closer to the nozzle 302 than the holding position (position P) of the leaf spring frame 333 at the end of the piezoelectric element 332 opposite to the nozzle plate 301. be.

Further, as described above, the nozzle plate 301 having the nozzles 302 for discharging the liquid, the needle valve 331 for opening and closing the nozzles 302, the piezoelectric elements 332, and the piezoelectric elements 332 are held, and the piezoelectric elements 332 are driven to elastically deform. A head 300 comprising: a drive unit 330 having a plate spring frame 333 for transmitting the driving force of a piezoelectric element 332 to a needle valve 331; and a housing 310 holding the nozzle plate 301 and accommodating the drive unit 330 , the fixing point 314 of the drive unit 330 with respect to the housing 310 is located closer to the nozzle 302 than the central position of the piezoelectric element 332 in the fluid ejection direction.

Further, as described above, the nozzle plate 301 having the nozzles 302 for discharging the liquid, the needle valve 331 for opening and closing the nozzles 302, the piezoelectric elements 332, and the piezoelectric elements 332 are held, and the piezoelectric elements 332 are driven to elastically deform. A head 300 comprising: a drive unit 330 having a plate spring frame 333 for transmitting the driving force of a piezoelectric element 332 to a needle valve 331; and a housing 310 holding the nozzle plate 301 and accommodating the drive unit 330 , the fixing point 314 of the drive unit 330 with respect to the housing 310 is located on the nozzle 302 side of the central position of the housing 310 in the liquid ejection direction.

As a result, the effect of shrinkage due to heat can be suppressed to the shrinkage occurring between the free length L2 from the fixed point 314 to the tip of the needle valve 331, and the head 300 is less susceptible to thermal effects when the nozzle 302 is blocked. can provide.

Also, the amount of shrinkage (ΔL) depends on the material selection of each member. For example, due to material costs, the piezoelectric element 332 and leaf spring frame 333 are made of a material that shrinks as the temperature rises. In some cases, materials with properties that In that case, the amount of contraction of the piezoelectric element 332 and the plate spring frame 333 may be larger than the amount of expansion of the housing 310 and the needle valve 331 . In such a case, the amount of contraction (ΔL) is not only the amount of contraction of the piezoelectric element 332 and leaf spring frame 333, but also the amount of expansion of the housing 310 and the needle valve 331. Therefore, the amount of contraction (ΔL) increases further. end up To address this, for example, the housing 310 is made of a material with a low coefficient of thermal expansion to reduce the amount of expansion.

As described above, in this embodiment, the housing 310 is made of a material having a lower coefficient of thermal expansion than the needle valve 331 , piezoelectric element 332 and leaf spring frame 333 . As a result, the expansion due to thermal expansion of the housing 310 is reduced, and the overall contraction amount (ΔL) can be further reduced.

6A and 6B are schematic diagrams showing a modification of the drive unit according to the embodiment of the present invention, where FIG. 6A is a schematic plan view and FIG. 6B is a schematic side view.

In this modified example, as in the above embodiment, the housing 510 holds a nozzle plate 501 having nozzles 502 for ejecting liquid, and accommodates a drive unit 530 therein. In the above embodiment, the leaf spring frame 333 (needle valve holding portion 333a) holds the needle valve 331 as shown in FIG. They are different in that they are held. The configuration of the modified example will be described below.

A housing 510 holds the nozzle plate 501 and has a flow path 512 for passing liquid on the rear side of the nozzle plate 501 (on the right side in the drawing). Housing 510 also includes space 522 for accommodating drive unit 530 . The drive unit 530 includes a needle valve 531 , a piezoelectric element 532 , a plate spring frame 533 and a lever mechanism 534 . The tip of the needle valve 531 faces the nozzle 502 provided on the nozzle plate 501 , and the tip of the needle valve 531 contacts the nozzle plate 501 to close the nozzle 502 . A seal member 515 such as an O-ring is mounted between the housing 510 and the needle valve 531 to prevent the liquid passing through the flow path 512 from flowing into the piezoelectric element 532 side.

A leaf spring frame 533 of the drive unit 530 includes a deformation portion 533a, a frame portion 533b, an expansion/contraction portion 533c, a space 533d, and the like. The deformation portion 533a has a shape such that the tip portion (left side in the drawing) of the frame portion 533b is branched into two, and the piezoelectric element 532 pushes the plate spring frame 333 toward the nozzle 502 (in the direction of the arrow a). , the deformation portion 533a is configured to deform in the direction of the arrow b. The frame portion 533b is made of, for example, a metal plate, and has a space 533d in the center. The expansion/contraction portion 533c is a leaf spring formed integrally with a portion of the frame portion 533b, and this portion is expandable/contractable. A space 533 d of the plate spring frame 533 forms an installation space for the piezoelectric element 532 .

The plate spring frame 533 holds both ends of the piezoelectric element 532 in the longitudinal direction by the restoring force of the expansion/contraction portion 533c so as to sandwich the piezoelectric element 532 between the spaces 533d. In this modified example, the plate spring frame 533 includes the deformation portion 533a, the frame portion 533b, and the expansion/contraction portion 533c as an integral member. good. For example, the elastic portion 533c may be configured with a spring or the like, and the spring may be attached to the frame portion 533b.

The lever mechanism 534 is made of an elastically deformable member formed by molding rubber, soft resin, or a thin metal plate, and has a trapezoidal bent shape as shown in FIG. 6(a). . An end portion 534a of the lever mechanism portion 534 is fixed to a deformation portion 533a of the plate spring frame 533, and a needle valve holding portion 534b holds the needle valve 531. As shown in FIG. Here, in this modified example, the nozzle plate 501 is an example of a "nozzle member", the needle valve 531 is an example of a "valve element", and the piezoelectric element 532 is an example of an "actuator". Further, the leaf spring frame 533 is an example of the "elastic member", the lever mechanism portion 534 is an example of the "moving mechanism", and the housing 510 is an example of the "accommodating member".

In the lever mechanism portion 534 having the structure described above, when a predetermined voltage is applied to the piezoelectric element 532, the piezoelectric element 532 extends. portion is pressed toward the nozzle 502 (in the direction of arrow a). Then, the deformation portion 533a of the plate spring frame 533 deforms toward the piezoelectric element 532 (in the direction of arrow b), and accordingly, the lever mechanism portion 534 having the end portion 534a fixed to the deformation portion 533a opens in the direction of arrow b. It transforms like As a result, the needle valve 531 held by the needle valve holding portion 534b moves toward the piezoelectric element 532 (in the direction of arrow c), and the nozzle 502 is opened. Note that when no voltage is applied to the piezoelectric element 532 , no external force is applied to the lever mechanism 534 , and the above-described deformation does not occur, so the needle valve 531 closes the nozzle 502 .

The drive unit 530 is attached to the housing 510 by, for example, fastening a screw hole 510a provided in the housing 510 and a screw hole 533g provided in the plate spring frame 533 with a screw 510b. At this time, also in this modified example, fixing points 514 (fastened portions by screw holes 510a and 533g and screws 510b) as fixing positions of the drive unit 530 to the housing 510 are provided as close to the nozzle plate 501 side as possible. This makes it possible to limit the amount of contraction (ΔL) of the drive unit 530 due to heat to the effect of the contraction from the fixed point 514 to the tip of the needle valve 531 .

Specifically, the fixing point 514 is arranged closer to the nozzle 502 than the holding position (for example, position P) of the piezoelectric element 532 on the opposite side of the nozzle plate 501 by the plate spring frame 533 . More preferably, the fixing point 514 is arranged closer to the nozzle 502 than half (L3/2) of the length L3 of the piezoelectric element 532 in the longitudinal direction (liquid ejection direction). Alternatively, the fixing point 514 is arranged closer to the nozzle 502 than half (L4/2) of the length L4 in the longitudinal direction (in the liquid ejection direction) of the housing 510 .

Even in the head 500 in which the lever mechanism 534 is interposed between the needle valve 531 and the plate spring frame 533, the effect of contraction due to heat is generated between the fixed point 514 and the tip of the needle valve 531. It is possible to suppress the contraction to a small amount, and it is possible to make it difficult to be affected by heat when the nozzle 502 is blocked.

FIG. 7 is an overall perspective view of the liquid ejection device according to the embodiment of the invention. The liquid ejection device exemplified here is a printing device that forms an image on, for example, the side surface of a truck body.

A printing apparatus 1000 is installed facing an object to be drawn 100, which is an example of an object. The printing apparatus 1000 includes an X-axis rail 101 , a Y-axis rail 102 intersecting the X-axis rail 101 , and a Z-axis rail 103 intersecting the X-axis rail 101 and the Y-axis rail 102 . The Y-axis rail 102 holds the X-axis rail 101 so that the X-axis rail 101 can move in the Y direction (positive side and negative side). Also, the X-axis rail 101 holds the Z-axis rail 103 so that the Z-axis rail 103 can move in the X direction (positive side and negative side). The Z-axis rail 103 holds the carriage 1 so that the carriage 1 can move in the Z direction (positive side and negative side).

The printing apparatus 1000 includes a first Z-direction drive unit 92 that moves the carriage 1 along the Z-axis rails 103 in the Z direction, and an X-direction drive unit 72 that moves the Z-axis rails 103 along the X-axis rails 101 in the X direction. Prepare. The printing apparatus 1000 also includes a Y-direction drive unit 82 that moves the X-axis rail 101 along the Y-axis rail 102 in the Y direction. Further, the printing apparatus 1000 includes a second Z-direction driving section 93 that moves the head holder 70 with respect to the carriage 1 in the Z-direction.

The printing apparatus 1000 configured as described above ejects ink, which is an example of a liquid, from the liquid ejection head provided on the head holder 70 while moving the carriage 1 in the X, Y and Z directions, and draws on the object 100 to be drawn. I do. Note that the movement of the carriage 1 and head holder 70 in the Z direction does not necessarily mean that the movement is parallel to the Z direction, and may be an oblique movement as long as it includes at least a component in the Z direction. Here, the rails 101, 102, 103 and the drive units 72, 82, 92, 93 are examples of "moving means".

In the drawing, the surface shape of the object 100 to be drawn is flat, but the surface shape of the object to be drawn 100 may be a nearly vertical surface such as the body of a car or truck, a surface with a large radius of curvature, or a slightly uneven surface. It may be a surface having

FIG. 8 is an overall perspective view of the carriage of the printing apparatus shown in FIG. 7, and is a view of the carriage 1 from the drawing object 100 side.

The carriage 1 has a head holder 70 . Further, the carriage 1 can move in the Z direction (positive side and negative side) along the Z-axis rail 103 by the power from the first Z-direction driving section 92 shown in FIG. The head holder 70 can be moved in the Z direction (positive side and negative side) with respect to the carriage 1 by power from the second Z-direction driving section 93 shown in FIG. The head holder 70 also has a head fixing plate 70a for mounting the liquid ejection head 300 thereon. Here, a configuration is illustrated in which six heads 300 described in FIGS. 1 to 5 are attached to the head fixing plate 70a, and the six heads 300a to 300f are arranged in layers. Of course, instead of the head 300, the head 500 described with reference to FIG. 6 may be used.

Each of the liquid ejection heads 300a-300f has a plurality of nozzles 302. As shown in FIG. The types and number of ink colors used in the heads 300a to 300f may be different for each head, or may be the same for all. For example, if the liquid ejection device exemplified as the printing device 1000 is a coating device that uses a single color, the inks used in the heads 300a to 300f may be the same color. Also, the number of heads constituting the head 300 is not limited to six. The number of heads 300 may be seven or more, or may be less than six.

The head 300 is fixed to the head fixing plate 70a in a state in which the nozzle row of each head intersects the horizontal plane (XZ plane) and the arrangement direction of the plurality of nozzles 302 is tilted with respect to the X-axis as shown in the drawing. . In this state, the nozzle 302 ejects ink in a direction (positive side in the Z direction) that intersects the direction of gravity to perform desired drawing on the object 100 to be drawn.

FIG. 9 is a schematic configuration diagram showing another example of the liquid ejecting apparatus according to the embodiment of the invention, and FIG. 10 is a partially enlarged view of FIG. The liquid ejection device illustrated here is a printing device that forms an image on an aircraft body or the like.

The printing apparatus 2000 includes a linear rail 404 that linearly moves the carriage 1 back and forth, and an articulated robot 405 that moves the linear rail 404 to a predetermined position and holds it at that position. The articulated robot 405 has a robot arm 405a that can freely move like a human arm through a plurality of joints, and can move the tip of the robot arm 405a freely and place it in an accurate position. be able to.

As the articulated robot 405, for example, a 6-axis control type industrial robot having 6 axes, that is, 6 joints can be used. According to the 6-axis type articulated robot, the linear rail 404 can be caused to face the predetermined position of the drawing object 702 (aircraft) extremely accurately and quickly by teaching information about the motion in advance. The robot 405 is not limited to 6 axes, and may be an articulated robot having an appropriate number of axes such as 5 axes or 7 axes.

A robot arm 405 a of the robot 405 has a fork-shaped support member 424 . A vertical linear rail 423a is attached to the tip of the left branch portion 424a of the support member 424, and a vertical linear rail 423b is attached to the tip of the right branch portion 424b in parallel. Both ends of the linear rail 404 that movably holds the carriage 1 are supported by being bridged between two vertical linear rails 423a and 423b.

The carriage 1 has the configuration of the embodiment described with reference to FIG. The head includes the head 300 described above, a plurality of heads 300 for ejecting liquids of respective colors such as yellow, magenta, cyan, black, and white, or a head 300 having a plurality of nozzle rows. Each head 300 of the carriage 1 or each nozzle row of the head 300 is supplied with liquid of each color from an ink tank 330 . Also in this embodiment, the head 500 described with reference to FIG. 6 may be used.

The carriage 1 moves in the direction of the first axis by moving on the linear rails 404, and the second axis intersecting the first axis by moving the linear rails 404 on the vertical linear rails 423a, 423b. It is possible to move in the direction of Further, although not shown, the carriage 1 has a carriage in the direction of the third axis that intersects with the above-described first and second axes (the liquid ejection direction toward the drawing object 702 in this modification). A first driving means for moving 1 is provided. The carriage 1 also has second drive means for moving the above-described head relative to the carriage 1 in the direction of the third axis.

The printing apparatus 2000 moves the linear rail 404 to the drawing area of the object 702 to be drawn by the robot 405, drives the head 300 while moving the carriage 1 along the linear rail 404 according to the drawing data, and performs drawing. conduct. When the drawing for one line is completed, the head 300 of the carriage 1 is moved from one line to the next line by driving the vertical linear rails 423a and 423b. By repeating this operation, drawing can be performed on a desired drawing area of the object 702 to be drawn.

Application examples of the present invention will be described below with reference to FIGS. 11 to 14. FIG. The present invention can also be applied to an unmanned aerial vehicle 6000, such as a drone, shown in FIG. The unmanned aerial vehicle 6000 controls the position of the unmanned aerial vehicle 6000 based on the detection result of a detector 610 such as a ranging sensor mounted on the unmanned aerial vehicle 6000 . The unmanned aerial vehicle 6000 includes a head 620 that ejects liquid such as ink, and supplies liquid stored in a liquid tank 630 to the head 620 via a cable 640 . Then, based on the position control described above, the unmanned aerial vehicle 6000 ejects the liquid from the head 620 toward the object (the wall surface of the building in this embodiment) 100 to apply the liquid to the coating portion P of the object 100 . In this case, it is possible to use the liquid ejection head of the present invention as the head 620 .

The present invention can also be applied to an unmanned vehicle 7000 such as a wall climbing robot shown in FIG. The unmanned vehicle 7000 can move by driving the rollers 710 while sucking the object (the wall surface of the building in this embodiment) 100 at the bottom of the unmanned vehicle 7000 . The unmanned vehicle 7000 includes a head 720 that ejects liquid such as ink, and supplies liquid stored in a liquid tank 730 to the head 720 via a cable 740 . Then, the unmanned vehicle 7000 ejects the liquid from the head 720 toward the object (the wall surface of the building in this embodiment) 100 to apply the liquid to the coating portion P of the object 100 . In this case, it is possible to use the liquid ejection head of the present invention as the head 720 .

The present invention can also be applied to the painting robot 8000 shown in FIG. 13 for painting the body of an automobile, for example. The painting robot 8000 has a robot arm 810 that can freely move like a human arm through a plurality of joints, and a head 820 that discharges liquid at the tip of the robot arm 810 . The robot arm 810 also has a 3D sensor 830 near the head 820 . As the coating robot 8000, an articulated robot having an appropriate number of axes such as 5, 6, or 7 axes can be used. The painting robot 8000 detects the position of the head 820 with respect to the object (the vehicle body in this embodiment) 100 by the 3D sensor 830 and moves the robot arm 810 based on the detection result to paint the object 100 . In this case, it is possible to use the liquid ejection head of the present invention as the head 820 .

The present invention can also be applied to an unmanned vehicle 9000 such as a road-traveling robot shown in FIG. The unmanned vehicle 9000 can move an object (a road surface such as a roadway or sidewalk in this embodiment) 100 by driving wheels 910 . The unmanned vehicle 9000 includes a head 920 that ejects liquid such as ink, and supplies liquid stored in a liquid tank 930 to the head 920 via a cable 940 . Then, the unmanned vehicle 9000 ejects the liquid from the head 920 toward the object 100, applies the liquid to the painted portion P of the object 100, and forms, for example, a pedestrian crossing, a stop line, a center line, etc. on the road surface. In this case, it is possible to use the liquid ejection head of the present invention as the head 920 .

In the present invention, liquids include solvents such as water and organic solvents, colorants such as dyes and pigments, functional imparting materials such as polymerizable compounds, resins and surfactants, DNA, amino acids, proteins, calcium and the like. Solutions, suspensions, emulsions, etc. containing biocompatible materials, edible materials such as natural pigments, and the like may also be used. These can be used, for example, as inkjet inks, coating materials, surface treatment liquids, liquids for forming components of electronic elements and light-emitting elements, electronic circuit resist patterns, material liquids for three-dimensional modeling, and the like.

Further, although the nozzle plate 301 and the housing 310 are separate members in the above embodiment, they may be integrally formed as a single member. When both are formed of a single member, the side where the needle valve 331 is provided is defined as the housing 310 and the side where the needle valve 331 is not provided, with the position where the tip of the needle valve 331 and the nozzle plate 301 abut as a boundary. is defined as a nozzle plate 301 .

Further, the liquid ejection apparatus according to the present invention is not limited to the configuration in which the liquid ejection head is moved with respect to the object. As long as the liquid ejection head and the object are relatively movable, the object may be moved with respect to the liquid ejection head.

What has been described above is only an example, and the present invention has specific effects in each of the following aspects.

[First aspect]
A first aspect includes a nozzle member (e.g., nozzle plate 301) having a nozzle (e.g., nozzle 302) that ejects a liquid, a valve body (e.g., needle valve 331) that opens and closes the nozzle, an actuator (e.g., piezoelectric element 332), and a drive unit (for example, drive unit 330) having an elastic member (for example, leaf spring frame 333) that holds the actuator and is elastically deformed by driving the actuator to transmit the driving force of the actuator to the valve body; a housing member (e.g., housing 310) that holds a member and houses the drive unit, wherein a fixed position (e.g., a fixing point 314 ) is closer to the nozzle than the holding position (for example, position P) by the elastic member at the end of the actuator opposite to the nozzle member.

[Second aspect]
A second aspect includes a nozzle member (eg, nozzle plate 301) having a nozzle (eg, nozzle 302) that ejects liquid, a valve body (eg, needle valve 331) that opens and closes the nozzle, an actuator (eg, piezoelectric element 332), and a drive unit (for example, drive unit 330) having an elastic member (for example, leaf spring frame 333) that holds the actuator and is elastically deformed by driving the actuator to transmit the driving force of the actuator to the valve body; a housing member (e.g., housing 310) that holds a member and houses the drive unit, wherein a fixed position (e.g., a fixing point 314 ) is located closer to the nozzle than the central position of the actuator in the ejection direction of the fluid (for example, half the length L3 in the ejection direction).

[Third aspect]
A third aspect includes a nozzle member (e.g., nozzle plate 301) having a nozzle (e.g., nozzle 302) that ejects liquid, a valve body (e.g., needle valve 331) that opens and closes the nozzle, an actuator (e.g., piezoelectric element 332), and a drive unit (for example, drive unit 330) having an elastic member (for example, leaf spring frame 333) that holds the actuator and is elastically deformed by driving the actuator to transmit the driving force of the actuator to the valve body; a housing member (e.g., housing 310) that holds a member and houses the drive unit, wherein a fixed position (e.g., a fixing point 314 ) is located closer to the nozzle than the central position (for example, half of the ejection direction length L4) of the accommodating member in the ejection direction of the liquid.

According to the first to third aspects, it is possible to provide a liquid ejection head that is less susceptible to thermal effects when the nozzles are clogged.

[Fourth mode]
A fourth aspect is any one of the first to third aspects, wherein the housing member (e.g., housing 310) comprises the valve element (e.g., needle valve 331), the actuator (e.g., piezoelectric element 332), and the elastic member ( For example, it is characterized by being made of a material having a lower coefficient of thermal expansion than the plate spring frame 333).

According to the fourth aspect, expansion due to thermal expansion of the housing member is reduced, and the overall amount of shrinkage can be further reduced.

[Fifth aspect]
A fifth aspect is any one of the first to fourth aspects, wherein the liquid ejection head (e.g., head 500) is provided between the valve element (e.g., needle valve 531) and the actuator (e.g., piezoelectric element 532). It is characterized by having a moving mechanism (for example, a lever mechanism section 534).

According to the fifth aspect, it is possible to provide a liquid ejection head that is less likely to be affected by heat when the nozzles are blocked, even in the configuration in which the movement mechanism is provided between the valve element and the actuator.

300 liquid ejection head 301 nozzle plate 302 nozzle 330 drive unit 331 needle valve 332 piezoelectric element 333 plate spring frame 314 fixed point

Japanese Unexamined Patent Application Publication No. 2010-241003

Claims (6)

a nozzle member having a nozzle for ejecting liquid;
a drive unit having a valve body for opening and closing the nozzle, an actuator, and an elastic member holding the actuator and elastically deformed by driving the actuator to transmit the driving force of the actuator to the valve body;
a housing member that holds the nozzle member and houses the drive unit;
A liquid ejection head comprising
A liquid ejection head according to claim 1, wherein a fixed position of the drive unit with respect to the housing member is closer to the nozzle than a holding position of the elastic member at an end of the actuator opposite to the nozzle member. a nozzle member having a nozzle for ejecting liquid;
a drive unit having a valve body for opening and closing the nozzle, an actuator, and an elastic member holding the actuator and elastically deformed by driving the actuator to transmit the driving force of the actuator to the valve body;
a housing member that holds the nozzle member and houses the drive unit;
A liquid ejection head comprising
A liquid ejection head according to claim 1, wherein a fixed position of the drive unit with respect to the housing member is closer to the nozzle than a central position of the actuator in the ejection direction of the fluid. a nozzle member having a nozzle for ejecting liquid;
a drive unit having a valve body for opening and closing the nozzle, an actuator, and an elastic member holding the actuator and elastically deformed by driving the actuator to transmit the driving force of the actuator to the valve body;
a housing member that holds the nozzle member and houses the drive unit;
A liquid ejection head comprising
A liquid ejection head according to claim 1, wherein a fixed position of the drive unit with respect to the containing member is closer to the nozzle than a central position of the containing member in the liquid discharging direction. 4. The liquid ejection head according to claim 1, wherein the housing member is made of a material having a lower coefficient of thermal expansion than the valve body, the actuator and the elastic member. 5. The liquid ejection head according to claim 1, further comprising a moving mechanism between the valve body and the actuator. a liquid ejection head according to any one of claims 1 to 5;
moving means for relatively moving the nozzle and the object;
A liquid ejection device comprising:

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