Droplet ejection module, droplet ejection head, and droplet ejection device

Abstract

To provide a liquid droplet discharge module in which a fixing member for positionally fixing a drive body is hardly deviated.SOLUTION: A liquid droplet discharge module includes: a valve element 331 which opens and closes a nozzle 302; a drive body (piezoelectric element 332) which extends and contracts in a longitudinal direction; a holding body 370 which holds the drive body and supports the valve element at one end in the longitudinal direction; a cylindrical housing 310b which stores the holding body; a fixing member 361 which abuts on the other end in the longitudinal direction of the holding body, has a slitting groove 361b formed to extend in the longitudinal direction, and is fixed to the housing; and an expansion member (worm screw 380) which expands an interval of the slitting groove. In the liquid droplet discharge module, the interval of the slitting groove is expanded by the expansion member and an outer peripheral surface of the fixing member is fixed to an inner peripheral surface of an outer member.SELECTED DRAWING: Figure 4A

Description

[Technical Field]

[0001] The present invention relates to a droplet ejection module that uses a driving body such as a piezoelectric element, and a droplet ejection head and a droplet ejection device that include the droplet ejection module. [Background technology]

[0002] An example of an image forming apparatus equipped with a droplet ejection device is an inkjet printer, as described in Patent Document 1 (JP 2020-23177 A). The inkjet head (droplet ejection head) of this droplet ejection device is provided with a nozzle for ejecting droplets toward a recording medium. A valve body is disposed inside the nozzle, and a driving body (actuator) such as a piezoelectric element that expands and contracts in the longitudinal direction is connected to the valve body.

[0003] The valve element opens and closes as the driver expands and contracts (vibrates) in the longitudinal direction, and the moment the valve element opens, high-pressure ink is ejected as droplets from the nozzle. The driver element is housed in a compressed state in a holder that is elastically expandable in the longitudinal direction. The valve element is supported and connected to one longitudinal end of the holder, while the other longitudinal end on the opposite side is fixed to the housing of the inkjet head. Summary of the Invention [Problem to be solved by the invention]

[0004] 9, in order to adjust the deformation amount of the valve body, the position of a fixing member 361 on the housing 310b side, which abuts the other longitudinal end of the holder 370, is adjusted in the axial direction (vertical direction), and the fixing member 361 is fixed with a bolt 362. However, it has been found that even when the relative positions of the nozzle 302 and the valve body 331 are accurately adjusted and the bolt 362 is completely tightened, variations occur in the discharge flow rate of droplets.

[0005] 10(a) to 10(c), the droplet discharge flow rate is determined by the valve opening / closing time and the valve element displacement (stroke), which is determined by the valve element displacement required to seal the valve element with the piezoelectric element displacement.

[0006] The amount of valve element displacement is determined by the adjusted position of the fixing member 361, but a stroke change occurs when the bolt 362 is fixed after the adjusted position of the fixing member 361 has been determined. This occurs because, when the bolt 362 is tightened, the dish-shaped head of the bolt 362 rubs against the side surface of the housing 310b, causing the tip of the bolt 362 to swing (oscillate) in the axial direction. When the tip of the bolt 362 swings (oscillates) in the axial direction, the stroke change causes fluctuations in the droplet discharge flow rate.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a droplet ejection module that can prevent displacement of a fixing member that fixes the position of a driver. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the droplet ejection module of the present invention includes a valve body that opens and closes a nozzle, a drive body that expands and contracts in a longitudinal direction, a holder that holds the drive body and supports the valve body at one end in the longitudinal direction, a cylindrical housing that accommodates the holder, a fixing member that abuts against the other end in the longitudinal direction of the holder and has a slot formed therein that extends in the longitudinal direction and is fixed to the housing, and an expansion member that widens the interval of the slot, and the expansion member widens the interval of the slot, and the outer peripheral surface of the fixing member is housing The present invention is characterized in that the inner peripheral surface of the [Effects of the Invention]

[0009] The present invention can prevent the fixing member from being displaced. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an explanatory diagram illustrating the appearance of a droplet ejection head according to an embodiment of the present invention. [Figure 2] 1 is an overall cross-sectional view of a droplet ejection head according to an embodiment of the present invention. [Figure 3] FIG. 4 is an explanatory diagram showing the position of a heating means of a droplet ejection head. [Figure 4A] 1 is a cross-sectional view of a droplet ejection module according to a first embodiment. [Figure 4B] FIG. 10 is a cross-sectional view of a droplet ejection module according to a second embodiment. [Figure 4C] FIG. 10 is a cross-sectional view of a droplet ejection module according to a third embodiment. [Figure 5] FIG. 10 is a cross-sectional view of a droplet ejection module according to a fourth embodiment. [Figure 6A] FIG. 10 is a cross-sectional view of a droplet ejection module according to a fifth embodiment. [Figure 6B] FIG. 10 is an exploded view of a droplet ejection module according to a fifth embodiment. [Figure 7] FIG. 10 is a cross-sectional view of a droplet ejection module according to a sixth embodiment. [Figure 8] 1 is a schematic diagram illustrating the overall configuration of a droplet ejection device. [Figure 9] FIG. 1 is a cross-sectional view of a conventional droplet ejection module. [Figure 10] 10 is a graph illustrating variations in droplet discharge flow rate due to variations in valve element displacement amount. DETAILED DESCRIPTION OF THE INVENTION

[0011] (● Droplet ejection head) Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is an explanatory view of the appearance of a droplet ejection head according to an embodiment of the present invention. Fig. 1(a) is an overall perspective view of the droplet ejection head, and Fig. 1(b) is an overall side view of the same head.

[0012] The droplet ejection head 300 includes a housing 310a and a housing 310b bonded (laminated) to the housing 310a. The housing 310a is made of a material with high thermal conductivity such as metal, and the housing 310b is made of a material with low thermal conductivity such as resin.

[0013] The housing 310a is provided with heaters 340 on its front and rear surfaces. The heaters 340 are temperature-controllable and heat the housing 310a. The housing 310b is provided with a connector 350 on its top surface for communicating electrical signals.

[0014] Here, housing 310a is an example of a first housing, and housing 310b is an example of a second housing. Heater 340 is an example of a heating means. In the following description, when the two housings are collectively referred to, they will be referred to as housing 310.

[0015] 2 is an overall cross-sectional view (cross-sectional view taken along the arrow AA in FIG. 1(a)) of a droplet ejection head 300 according to an embodiment of the present invention. A housing 310a holds a nozzle plate 301 equipped with nozzles 302 that eject droplets. The housing 310a also includes a flow path 312 (liquid supply unit) that sends liquid from a supply port 311 side through the nozzle plate 301 to a recovery port 313 side.

[0016] Housing 310b has a supply port 311 and a recovery port 313 that connect to flow path 312 of housing 310a. Between supply port 311 and recovery port 313, a droplet ejection module 330 is disposed for ejecting the liquid in flow path 312 from nozzle 302 as droplets.

[0017] (● Droplet ejection module) The number of droplet ejection modules 330 corresponds to the number of nozzles 302 provided in the housing 310a, and in this example, a configuration is shown that includes eight droplet ejection modules 330 corresponding to the eight nozzles 302 arranged in a row. Note that the number and arrangement of the nozzles 302 and droplet ejection modules 330 are not limited to those described above.

[0018] For example, the number of nozzles 302 and droplet ejection modules 330 may be one instead of multiple. Furthermore, the nozzles 302 and droplet ejection modules 330 may be arranged in multiple rows instead of one line.

[0019] 2, reference numeral 315 denotes a seal member provided at the joint between housing 310a and housing 310b. In this example, an O-ring is used as seal member 315, which prevents liquid from leaking from the joint between housing 310a and housing 310b.

[0020] With the above configuration, supply port 311 takes in pressurized liquid (ink, paint, etc.) from the outside, sends the liquid in the direction of arrow a1, and supplies the liquid to flow path 312. Flow path 312 sends the liquid from supply port 311 in the direction of arrow a2. Then, recovery port 313 recovers the liquid that was not ejected from nozzles 302 arranged along flow path 312 in the direction of arrow a3.

[0021] The droplet discharge module 330 includes a valve element 331 that opens and closes the nozzle 302, and a piezoelectric element 332 that serves as a driver for driving the valve element 331. The piezoelectric element 332 expands and contracts in the longitudinal direction when a voltage is applied. The housing 310b includes a regulating member 314 at a position facing the upper end of the piezoelectric element 332. The regulating member 314 abuts against the upper end of the piezoelectric element 332, and serves as a fixing point for the piezoelectric element 332.

[0022] Here, the nozzle plate 301 is an example of a plate member, the nozzle 302 is an example of a droplet ejection port, the valve body 331 is an example of a valve body, and the piezoelectric element 332 is an example of a driver.

[0023] In the above configuration, when the piezoelectric element 332 is actuated to move the valve element 331 upward, the nozzle 302 that was closed by the valve element 331 opens, and droplets can be ejected from the nozzle 302. When the piezoelectric element 332 is actuated to move the valve element 331 downward, the tip of the valve element 331 abuts against the nozzle 302, closing the nozzle 302 and preventing droplets from being ejected from the nozzle 302.

[0024] 3 is an explanatory diagram showing the positional relationship with the heating means of the droplet ejection head 300 according to an embodiment of the present invention. The housing 310a includes a heater 340 in the vicinity of the nozzles 302 so as to cross the nozzles 302, as shown by the dashed lines in FIG.

[0025] (●Thermal expansion of droplet ejection head) Next, we will explain thermal expansion of the droplet ejection head 300. In the droplet ejection head 300, which opens and closes the nozzle 302 by moving the valve element 331 with the piezoelectric element 332, when the piezoelectric element 332 is continuously driven at a high frequency, heat generated by the piezoelectric element 332 causes thermal expansion in the piezoelectric element 332 and the valve element 331. As described in the explanation of Figure 2, the piezoelectric element 332 is fixed to the restricting member 314 at the upper end of the piezoelectric element 332, so the thermally expanded piezoelectric element 332 stretches in the direction of arrow a4 in Figure 4(a) and presses the valve element 331 down toward the nozzle plate 301.

[0026] Furthermore, the heat from the piezoelectric element 332 is also transferred to the valve element 331 that is in contact with the piezoelectric element 332, and the valve element 331 itself also expands in the direction of arrow a5 due to thermal expansion. As a result, at the contact portion between the tip 331a of the valve element 331 and the nozzle plate 301, a state occurs in which the tip 331a is pressed into the nozzle plate 301.

[0027] Because the amount of displacement of the valve element 331 due to the operation of the piezoelectric element 332 is constant, the greater the amount that the tip 331a of the valve element 331 is pressed into the nozzle plate 301, the more difficult it becomes to open the nozzle 302. For example, in a state where no thermal expansion is occurring, the valve element 331 rises by a predetermined amount due to the operation of the piezoelectric element 332, forming an appropriate gap between the nozzle plate 301 and the tip 331a of the valve element 331. The liquid in the flow path 312 passes through this gap and can be ejected from the nozzle 302.

[0028] However, when the tip 331a of the valve element 331 is wedged into the nozzle plate 301 due to thermal expansion, even if the valve element 331 is raised by a predetermined amount, it is not possible to obtain an appropriate gap between the nozzle plate 301 and the valve element 331. The gap between the nozzle plate 301 and the valve element 331 becomes narrower than the appropriate value, and the fluid resistance of the liquid increases, so the droplet discharge speed from the nozzle 302 also decreases, and it becomes impossible to obtain the desired appropriate discharge amount.

[0029] Furthermore, because the housing 310 is not in contact with the piezoelectric element 332, there is almost no thermal expansion of the housing 310 due to the heat from the piezoelectric element 332. In other words, while the piezoelectric element 332 and the valve body 331 inside the housing 310 are stretched due to thermal expansion, the housing 310 and the nozzle plate 301 are hardly affected by the thermal expansion due to the heat from the piezoelectric element 332. This difference in thermal expansion also causes misalignment in the relative positions of the nozzle 302 and the valve body 331 in the horizontal direction.

[0030] Additionally, the environmental temperature around the head can also cause expansion and contraction of the nozzle plate 301 and the housing 310a. When expansion and contraction of the housing 310a occurs, just as when the piezoelectric element 332 generates heat, an appropriate gap cannot be obtained between the nozzle plate 301 and the tip 331a of the valve element 331, and the desired appropriate amount of ejection cannot be obtained.

[0031] As described above, this embodiment is a droplet ejection head 300 having a nozzle plate 301 equipped with nozzles 302 that eject droplets, a valve element 331 that opens and closes the nozzles 302, a piezoelectric element 332 that drives the valve element 331, and a housing 310 that holds the nozzle plate 301, the valve element 331, and the piezoelectric element 332. A heater 340 that heats the housing 310 is provided near the nozzles 302 of the housing 310. This makes it possible to provide a droplet ejection head 300 that can reduce variations in droplet ejection due to temperature changes.

[0032] The housing 310 is made up of a housing 310a equipped with a heater 340 and a cylindrical housing 310b without a heater 340. The piezoelectric element 332 is provided in the housing 310b. This allows heat to be supplied intensively to the vicinity of the nozzle 302, and improves the responsiveness of the position correction of the nozzle 302 relative to the valve body 331.

[0033] Furthermore, the housing 310a is made of metal, and the housing 310b is made of resin, which makes it easier to increase the temperature around the nozzle 302, and improves the responsiveness of the position correction of the nozzle 302.

[0034] (First embodiment) Next, a first embodiment of a droplet ejection module 330 will be described with reference to Figure 4A. A compression spring 366 is disposed at the lower end of a housing 310b. A holder 370 that holds a piezoelectric element 332 is housed within the housing 310b above the compression spring 366. The holder 370 is urged upward by the compression spring 366.

[0035] Although the above configuration is preferable to improve the responsiveness of the position correction of the nozzle 302, instead, the housing 310a and the housing 310b may be formed from a single member. Also, the housing 310a and the nozzle plate 301 may be formed from a single member.

[0036] A valve element 331 is supported at one longitudinal end of the holder 370. Two O-rings 316 are attached to the outer periphery of the shaft of the valve element 331, one above the other, to prevent leakage of high-pressure ink.

[0037] The upper end of housing 310b accommodates fixing member 361 against which the other longitudinal end of holder 370, which holds piezoelectric element 332, abuts. A slotted groove 361b extending longitudinally from the upper end is formed in fixing member 361. A female threaded hole 361c is formed to pass through in the horizontal direction on one side of slotted groove 361b, and an unthreaded blind hole 361d is formed on the opposite side of slotted groove 361b.

[0038] A set screw 380, which serves as an expansion member or screw member, is threaded into the female threaded hole 361c so as to cross the slot 361b in the horizontal direction. A tip 380a of the set screw 380 abuts against the bottom of the blind hole 361d. A clearance hole 310b3 for inserting the set screw 380 is formed in the housing 310b.

[0039] The screw member is not limited to set screw 380. If there is room in the layout, a gap may be provided in housing 310b so that the screw member does not seat, and a member with a screw head such as a pan head screw or a bind screw may be used. Also, any member that has the function of widening slot 361b in the lateral direction may be used, and is not limited to a screw member.

[0040] The vertical position adjustment of fixing member 361 and its fixation relative to housing 310b are performed as follows. First, the vertical position of fixing member 361 is adjusted with set screw 380 loosened as shown in FIG. 4A. Then, set screw 380 is tightened in the direction of the arrow as shown in FIG. 4A, and tip 380a of set screw 380 presses against the bottom of blind hole 361d. This widens the gap between slotted grooves 361b in the direction of the arrow in FIG. 4A, and the outer peripheral surface of fixing member 361 is pressed against the inner peripheral surface of housing 310b.

[0041] In this way, the fixing member 361 can be fixed in position to the housing 310b. This allows the axial positions of the holder 370 and the valve element 331 relative to the housing 310b to be determined with high precision. When the set screw 380 is tightened, the set screw 380 does not come into contact with the housing 310b at all, so no reaction force associated with this contact acts on the fixing member 361. Therefore, there is no effect on the valve element displacement amount (stroke) as in the case of fixing the position using the bolt 362 in Figure 9(a).

[0042] Therefore, it is possible to reduce the variation in droplet discharge flow rate between channels as shown in Figure 10(c). Furthermore, by reducing the variation in discharge flow rate between channels, it is possible to improve convenience by shortening the time required for initial image adjustment and adjustment when replacing the head.

[0043] (Second embodiment) In Fig. 4A, set screw 380 is threaded into fixing member 361 so as to pass through clearance hole 310b3 of housing 310b and cross slot 361b, but as shown in Fig. 4B, it may be threaded into fixing member 361 on the outside of housing 310b. In this case, there is no need to form a clearance hole in housing 310b. Tightening set screw 380 widens slot 361b in the same manner as in Fig. 4A.

[0044] (Third embodiment) 4C shows a configuration in which a female screw hole 361e is formed in the longitudinal direction (vertical direction) on the inner surface of the slotted groove 361b, and a tapered set screw 380 is screwed into the female screw hole 361e. The set screw 380 tapers and becomes larger in diameter toward the base end, so that the slotted groove 361b expands in the left-right direction as the set screw 380 is screwed into the female screw hole 361e. Therefore, as in FIGS. 4A and 4B, the fixing member 361 can be fixed to the housing 310b without the set screw 380 coming into contact with the housing 310b. This allows the axial positions of the retainer 370 and the valve element 331 relative to the housing 310b to be determined with high precision.

[0045] (Fourth embodiment) 5, a through hole for set screw 380 is formed in a direction crossing slot 361b of fixing member 361, with female threaded hole 361c formed on one side of slot 361b and a through hole without a female thread on the other side. Abutment plate 381 serving as an abutted member is housed in this through hole without a female threaded hole. Abutment plate 381 is housed in the through hole in a state where it can rotate in the rotation direction of set screw 380. Abutment plate 381 can be made of a copper alloy-based material, or it can be made of SUS, iron, aluminum alloy, etc. depending on the application and characteristics of the product.

[0046] When the set screw 380 is tightened and its tip 380a abuts against the abutment plate 381, and the back surface of the abutment plate 381 is pressed, the front surface of the abutment plate 381 is pressed against the inner surface of the housing 310b. As a result, the slotted groove 361b expands in the direction of the arrow (left and right direction) as in the previously described embodiment, and the fixing member 361 can be fixed to the housing 310b. This allows the axial positions of the holder 370 and the valve element 331 relative to the housing 310b to be determined with high precision.

[0047] Abutment plate 381 is configured to be rotatable in the rotation direction of set screw 380, and therefore it is possible to prevent the fastening force when set screw 380 is tightened from being transmitted to housing 310b. This makes it possible to prevent displacement of the positional relationship between housing 310b and fixing member 361 when fixing fixing member 361 to housing 310b by pressing it with set screw 380.

[0048] (Fifth embodiment) 6A and 6B show a configuration in which the position of the screwed member 363 is fixed using a plate-shaped second fixing member 390, without using a slot 361b or a set screw 380. The screwed member 363 has the same function as the fixing member 361 described above, and by abutting the other longitudinal end of the holder 370 against the screwed member 363, the axial positions of the holder 370 and the valve body 331 relative to the housing 310b are determined with high precision. That is, a male screw portion 363f extending outward in the longitudinal direction is formed at the upper end of the screwed member 363, and this male screw portion 363f is screwed into a female screw hole 390b of the second fixing member 390.

[0049] A plurality of loose holes 390a are formed around the female screw hole 390b in the second fixing member 390. The tips of bolts 391 inserted into these loose holes 390a are screwed into the female screw holes 310b4 on the housing 310b side to fix the second fixing member 390 to the housing 310b.

[0050] The vertical position of the threaded member 363 can be adjusted by rotating the threaded member 363. After the threaded member 363 is positioned, a nut 392 is screwed onto the male thread portion to prevent loosening. Even when the position of the threaded member 363 is fixed using the second fixing member 390 in this way, no force is applied to the housing 310b when the nut 392 is tightened, so the position of the threaded member 363 does not shift. Therefore, it is possible to prevent any effect on the valve element displacement amount (stroke).

[0051] (Sixth embodiment) 7 differs from the previously described embodiments in that no special member is used, and instead, an adherend 364 is directly fixed to the housing 310b with adhesive 395. The adherend 364 has the same function as the previously described fixing member 361, and since no force is applied to the housing 310b when the adherend 364 is adhered, the adherend 364 can be positioned in the axial direction with high precision.

[0052] This allows the axial positions of the holder 370 and the valve body 331 relative to the housing 310b to be determined with high precision. Because adhesive 395 is used, it is difficult to remove the adherend 364 once it has been fixed, but this has the advantage that the adherend 364 can be fixed in position simply and at low cost.

[0053] The adhesive 395 used for adhesive fixation can be an epoxy adhesive to obtain strength, weather resistance, etc. Since many epoxy adhesives require high temperature and long curing times, if strength, weather resistance, etc. are required, it is also possible to use a UV adhesive or anaerobic adhesive that can obtain bonding strength in a short time.

[0054] (Droplet discharge device) 8 is a schematic diagram of the entire configuration of a droplet discharge device 1000 that uses the droplet discharge module 330 described above. FIG. 8(a) is a side view of the droplet discharge device, and FIG. 8(b) is a plan view of the same device. The droplet discharge device 1000 is installed facing a drawing target 100, which is an example of an object. The droplet discharge device 1000 includes an X-axis rail 101, a Y-axis rail 102 that intersects with the X-axis rail 101, and a Z-axis rail 103 that intersects with the X-axis rail 101 and the Y-axis rail 102.

[0055] The Y-axis rail 102 holds the X-axis rail 101 so that the X-axis rail 101 can move in the Y-axis direction. The X-axis rail 101 also holds the Z-axis rail 103 so that the Z-axis rail 103 can move in the X-axis direction. The Z-axis rail 103 then holds the carriage 1 so that the carriage 1 can move in the Z-axis direction.

[0056] The droplet ejection device 1000 includes a first Z-direction drive unit 92 that moves the carriage 1 in the Z-axis direction along the Z-axis rail 103, and an X-direction drive unit 72 that moves the Z-axis rail 103 in the X-axis direction along the X-axis rail 101. The droplet ejection device 1000 also includes a Y-direction drive unit 82 that moves the X-axis rail 101 in the Y-axis direction along the Y-axis rail 102. The droplet ejection device 1000 also includes a second Z-direction drive unit 93 that moves the head holder 70 in the Z-axis direction relative to the carriage 1.

[0057] The droplet ejection head 300 described in the first to fourth embodiments is used by being attached to the head holder 70 so that the nozzles 302 of the head 300 face the drawing target 100. The droplet ejection device 1000 configured as described above ejects ink, an example of a liquid, from the head 300 (not shown) attached to the head holder 70 toward the drawing target 100 while moving the carriage 1 in the X-axis, Y-axis, and Z-axis directions, thereby drawing on the drawing target 100.

[0058] The "liquid ejection device" may be configured to include a robot arm that can move parallel to the three directions of the X-axis, Y-axis, and Z-axis and rotate around each of the X-axis, Y-axis, and Z-axis, with a droplet ejection head attached to the tip of the robot arm. In this configuration, while the robot arm is moved parallel to or rotated relative to the object to be drawn, droplets are ejected from the droplet ejection head toward the object to be drawn, thereby performing drawing on the object.

[0059] The above-mentioned "liquid ejection device" is not limited to devices that visualize meaningful images such as letters and figures using ejected liquid. For example, it also includes devices that form meaningless patterns or uniform paint films, and devices that create three-dimensional images.

[0060] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and various modifications are possible based on the technical ideas described in the claims. For example, the piezoelectric element 332 can be replaced with another driving body that expands and contracts in the longitudinal direction, and for example, a piston that expands and contracts in the longitudinal direction using an electromagnetic solenoid can be used instead of the piezoelectric element 332. [Explanation of symbols]

[0061] 1: Carriage 70: Head holder 72: X-direction drive unit 82: Y-direction drive unit 92: First Z-direction driving unit 93: Second Z-direction driving unit 100: Object to be drawn 101: X-axis rail 102: Y-axis rail 103: Z-axis rail 300: droplet ejection head 301: nozzle plate 302: Nozzle 310: Housing 310a: Housing 310b: Housing 310b3: Clear hole 310b4: Female screw hole 311: Supply port 312: Flow path 313: Collection port 314: Restriction member 315: Sealing material 316: O-ring 330: Droplet ejection module 331: Valve body 331a: Tip 332: Piezoelectric element (driver) 340: Heater 350: Connector 361: Fixing member 361b: Slotted groove 361c: Female thread hole 361d: Blind hole 361e: Female screw hole 362: Bolt 363: Screwed member 363a: Male thread part 364: Adhered member 366: Compression spring 370: Holder 380: Set screw (screw member, expansion member) 380a: Tip 381: Abutment plate 390: Second fixing member 390a: Clear hole 390b: Female screw hole 391: Bolt 392: Nut 395: Adhesive 1000: Droplet discharge device [Prior art documents] [Patent documents]

[0062] [Patent Document 1] Japanese Patent Publication No. 2020-23177

Claims

1. a valve body that opens and closes the nozzle; a driver that expands and contracts in the longitudinal direction; a holder that holds the driver and supports the valve body at one end in the longitudinal direction; a cylindrical housing that accommodates the holder; a fixing member that abuts against the other longitudinal end of the holder, has a slot formed therein extending in the longitudinal direction, and is fixed to the housing; and an expansion member that expands the interval between the slotted grooves, The droplet ejection module is characterized in that the expansion member widens the gap between the slots to fix the outer peripheral surface of the fixing member to the inner peripheral surface of the housing.

2. 2. The droplet ejection module of claim 1, wherein the expanding member has a threaded member that threadably engages with the fixed member across the slot.

3. 2. The droplet ejection module according to claim 1, wherein the expanding member has a tapered screw member that is threaded from the longitudinal direction into a female screw hole formed on the inner surface of the slotted groove and extending in the longitudinal direction.

4. 4. The droplet ejection module according to claim 1, wherein the driving element is a piezoelectric element.

5. A droplet discharge head comprising a plurality of droplet discharge modules according to claim 1 .

6. A droplet discharge device comprising the droplet discharge module according to any one of claims 1 to 4 or the droplet discharge head according to claim 5.

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