JPS61137753A - Apparatus for injecting liquid droplet - Google Patents

Abstract

PURPOSE:To prevent the interference to a liquid chamber wherein the application of voltage was stopped, by driving a piezoelectric converter at a unit of one jet nozzle. CONSTITUTION:A piezoelectric converter 11 has a characteristic stretched to the longitudinal direction and contracted to the side surface direction by non-driving or voltage applying driving. Therefore, the volumes of liquid storage chambers 3, 5 are contracted by the application of voltage and the volume of a gap passage part (a) is enlarged. The liquid in the liquid storage chamber 3 is injected from a jet nozzle 6 by the impactive stretching of the piezoelectric converter 11. An elastic constitutional body 8 opens a replenishing port 9 by liquid pressure in the liquid storage chamber 5 and, at the same time, a repulsive stream is generated in the direction of a liquid storage cylinder 5. The liquid in a liquid replenishing container 7 flows to the gap passage part (a) and is also assisted by the jet action of the repulsive stream. When the piezoelectric converter 11 comes to a non-driving state, the volumes of the liquid storage chambers 3, 5 are enlarged and the replenishing port 9 is closed and cylic volumetric conversion is repeated. The two-mode action of the piecoelectric converter exerts no interference on the volumetric alteration of a container of other one unit.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is applicable to printers, printing devices, etc., which have a piezoelectric ceramic in a liquid container that expands and contracts by repeatedly being driven by voltage application and non-driving by interruption of voltage application. , 'F4 injection device is used in the industrial field.

(Prior Art) Conventionally, a droplet ejecting device using piezoelectric conversion, which is used as an ink collector for a printer, is equipped with an ejecting nozzle at one end and has a liquid chamber configured to replenish the amount of liquid equivalent to the consumed amount. A piezoelectric transducer is bonded to the outer or inner surface of the relatively thin wall of the liquid chamber, and the transducer and the liquid chamber wall are deformed by applying a voltage. The volume of the liquid chamber was reduced, thereby applying pressure to the theater and causing droplets to be ejected from the nozzle. It is a multi-type device in which a piezoelectric transducer is connected to each chamber, and since the transducers are rarely driven all at once, the deformation shown in a + f is spread to the liquid chamber where voltage application is stopped. There are drawbacks such as interference.

(Problems to be Solved by the Invention) In conventional droplet injection devices, piezoelectric transducers are mainly connected to the outer surface of the liquid chamber wall, and rarely to the inner surface, in order to draw out the voltage application lead wire, and the voltage applied to the piezoelectric transducer is Since elastic deformation is generated each time voltage is applied, and the voltage application is frequently repeated, the above-mentioned drawbacks pose a problem in the durability of the liquid chamber constituent material.

(Means for solving the problem) The present invention causes a piezoelectric transducer to be driven to cause deformation in a liquid. A configuration that generates injection pressure without deforming the container wall and at the same time assists the flow of replenishment liquid into the liquid chamber,
The purpose of this is to solve the problems of the prior art by making it possible to form injection nozzles in individual units. A liquid chamber is formed, and a concave second liquid storage chamber is formed at the other end, and the first, ! A liquid container with a liquid storage cylinder formed between the liquid storage chambers @2, and a supply port provided around the boundary between the 81m storage chamber and the second liquid storage chamber, which is opened at the time of droplet injection or at all times for liquid replenishment. The liquid container is housed in a liquid cylindrical portion of the liquid container with its longitudinal center substantially supported, a gap communication portion is formed between the container and the peripheral wall of the cylindrical portion, and the liquid container is expanded and contracted by repeating driving and non-driving. It consists of a piezoelectric transducer, and the I+Q of the piezoelectric transducer
By driving or not driving, the volume of the first liquid storage chamber is reduced and droplets are ejected from the injection nozzle, and at the same time, the volume of the second liquid storage chamber is reduced and the liquid is stored along the wall surface of the chamber. The present invention is characterized in that a repulsive flow is generated that flows in the direction of the cylindrical portion, and the repulsive flow assists the replenishment liquid to flow from the supply port into the liquid storage cylindrical portion.

(Function) The piezoelectric transducer (11), which is supported at approximately the center in the longitudinal direction inside the liquid container (2), is not driven or when a voltage is applied [it expands in the longitudinal direction due to movement, and the piezoelectric transducer (11) is It has the characteristic of shrinking, and when shrinking, both ends of the head are
A space passageway (10) with a reduced volume is formed between the liquid storage chamber (3) and the second liquid storage chamber (5) and the peripheral wall of the liquid storage cylinder (2). When the moving image head is extended by driving or not driving and the volumes of the first liquid storage chamber (3) and the second liquid storage chamber (5) are reduced, each chamber (3),
In order to reduce the volume of (5) and dramatically increase the liquid pressure, a fixed amount of liquid droplets are ejected from the injection nozzle (6) in the first liquid storage chamber (3), and the second liquid storage chamber (5) The odor is released by pressurizing the bottom of the chamber using liquid pressure, and the reaction flow flows toward the liquid cylinder part (2), which has expanded its volume, and the liquid cylinder part (2)
In order to maintain the same pressure as the liquid, the inflow of liquid replenished from the replenishment port (9) is assisted by the noet action of the reaction flow, and as this action is repeated, droplets are intermittently jetted. .

(Embodiment) Figure 1.2 shows the first embodiment of the present invention, and case (1)
A liquid container (2) elongated in the ring direction is provided inside the container. The liquid container (2) constitutes a first liquid storage chamber (3) provided with an injection nozzle (6) at one end in the longitudinal direction, and a concave, more specifically, hemispherical, first liquid storage chamber (3) at the other end. There are two liquid storage chambers (5), and a cylindrical liquid storage cylinder (4) is provided between the first and second liquid storage chambers (3) and (5). The liquid storage cylinder part (4) is a first liquid storage chamber (
3) Slightly reduce the diameter of the portion (4a) that communicates with. The component (8) of the second liquid storage chamber (5) is an elastic body, and the liquid supply container (8) has an enlarged inner diameter near the lower end of the liquid storage cylinder (4).
7), a wall g (c+
A) is closed by elastically contacting the i-portion peripheral wall (8a) of the 6rf structure (8).

(11) is a piezoelectric transducer inserted into the storage afrN part (4) of the liquid container (2), and is formed into a long Ia rectangular shape of about 0.5XO, 5X25 mm, and is polarized on both sides perpendicular to the longitudinal direction. , electrodes (12) made of metal thin films on both sides,
(12) is provided, and the electric current is placed approximately at the center in the direction of the
Terminals (13), (
13), and piezoelectric conversion is achieved by the installation! A gap communication portion a is formed between the outer periphery of (11) and the wall of the liquid storage cylinder portion (4). (14) indicates a power supply, and (15) indicates a connected or non-contact α switch operated by a signal.

In this embodiment, the liquid container (2), liquid replenishment, and
(7) is filled with liquid, and the replenishment container (7) is configured to be able to replenish an amount of liquid commensurate with the amount of liquid lost by replenishing the liquid container 5 (2). When the matchlock shown in Fig. 1 is not driven, the liquid container (2) is replenished with liquid corresponding to the injection Mfl as will be explained later with reference to Fig. 'First and second liquid storage chambers with expanded IF product (3)
, (5) are filled with liquid, and the liquid replenishment container (7) is filled with an amount of liquid commensurate with the above-mentioned replenishment.

When a voltage is applied to the piezoelectric transducer (11) as shown in Fig. 2, the piezoelectric transducer (11) expands on both sides in the length direction centering on the support point provided by the terminal (13), and forms the first and second liquid storage chambers (3). ), reduce the volume of (5) and 1. At the same time, the volume of the FA passage section a is expanded. In the first reservoir (3) there is a piezoelectric transducer (11)
Due to the volume reduction due to the impulsive expansion of the liquid, the liquid in the liquid storage chamber (3) loses its pressure and is injected from the injection/:Xle (6). 1. In the second storage chamber (5), a piezoelectric transducer (11
) is expanded to pressurize the internal liquid toward the bottom of the contact (5), so the elastic structure (8) is pushed by the liquid pressure at that time and opens the supply port (9), and at the same time the pressure is increased. An arrow line 9 in which the liquid flows along the wall surface in the direction of the liquid storage cylinder part (4)
This causes a countercurrent. When the replenishment port (9) is opened as described above, the liquid replenishment container! (7) The liquid inside flows into the gap passage part a whose volume has been expanded and the pressure of the internal liquid has been reduced;
The inflow is assisted by the Noet action of the counterflow shown by arrow MA9.

When the piezoelectric transducer (11) is not driven, the liquid storage chamber (3), (
The volume of the component (5) is expanded as shown in Figure 1, and the volume of the component (8) is expanded as shown in Figure 1.
), the supply port (9) is closed,
The repulsive flow shown by arrow IIL9 also disappears, and the liquid pressure in the liquid container (2) including the gap passage section a whose volume has been reduced is averaged with quick response, and this cyclic volume conversion is performed as described above. Then, the injection of droplets from the injection nozzle (6) and the replenishment of the empty liquid replenishment container are repeated.

# & 3.4 Figures show a second embodiment, in which the structure (8') of the second iIII body container is formed of a hard material with no elasticity,
A supply port (9') is always opened in the reservoir 8 in a tapered shape toward the cylindrical portion (4). Since the other parts are the same as the first embodiment shown in FIG. 1.2, the same reference numerals as in the first embodiment are given to each part.

In this embodiment, when the piezoelectric transducer (11) is not driven, the liquid pressures of the liquid container (2) and the liquid replenishment container (8) are the same, so that the pressure at the replenishment port (9') is also the same. The liquid becomes stationary. When the piezoelectric transducer (11) shown in FIG.
) volume reduction, volume expansion of gap passage section (10), arrow 9
The generation of the repulsion flow shown in is the same as in the first embodiment, and the structure (8') is made of a hard material with no elasticity, and the supply port (9') is always open. There is no change in the effect.

The piezoelectric transducer (11) can be configured to expand when not driven and contract when voltage is applied. In that case, the timing of piezoelectric application is different from that in the first and second embodiments.
: Let.

The piezoelectric transducer is not limited to the configuration illustrated in FIGS. 1 to 4, but for example, as shown in FIG. I
The predetermined length of the barb is set, and the electrode (52) of each element is
It is connected by a metal lead (55) provided on the outside of each of the insulation J & membranes (54) and (54) on both sides, and a metal lead (
55) can be connected to a power source and supported approximately at the center in the length direction.

The present invention is not limited to the embodiments shown in FIGS. 1 to 4, but has many embodiments within the technical scope of the spirit of the invention.

(Effects of the Invention) The effects of the present invention are as described above, but the effect of the second effect is unique.With this configuration, e, It is useful to be able to configure droplet ejectors so that the bimodal action of the piezoelectric transducer can control the droplet ejector of each unit without interfering with volume changes in other units of the container. There is something C that can be activated.

[Brief explanation of the drawing]

Fig. 1.2 is a vertical side view showing the first embodiment of the present invention;
Fig. 3.4 is a longitudinal sectional side view showing the second embodiment. ! @Figure 5 is a longitudinal sectional front view showing an example of a piezoelectric transducer.

Claims (3)

[Claims] (1) The first liquid storage chamber is made longer in the axial direction and has an injection nozzle at one end of the length, and the second liquid storage chamber has a concave shape at the other end.
A liquid container with a liquid storage cylinder formed between the first and second liquid storage chambers, and a liquid container surrounding the boundary between the liquid storage cylinder and the second liquid storage chamber. A liquid replenishment container whose supply port is opened at the time of droplet jetting or always open, and a liquid storage cylinder portion of the liquid container supported approximately at the center in the length direction, and a gap communication portion between the liquid container and the peripheral wall of the cylinder portion. and a piezoelectric transducer that expands and deforms by repeating driving and non-driving, and the volume of the first liquid storage chamber is reduced by the driving or non-driving of the piezoelectric transducer, and droplets are injected from the injection nozzle. At the same time, the volume of the second liquid storage chamber is reduced to generate a repulsive flow flowing along the wall surface of the second liquid storage chamber in the direction of the liquid storage cylinder, and the repulsion flow causes a flow from the supply port to the liquid storage cylinder. A droplet injection device characterized by assisting the inflow of replenishment liquid. (2) The piezoelectric transducer is an elongated rectangular shape, polarized on both sides perpendicular to the longitudinal direction, and electrodes made of a thin metal film are provided on both sides of the piezoelectric transducer.
1) The droplet jetting device described above. (3) Claim (1) characterized in that the piezoelectric transducer has a predetermined elongated length made by stacking a large number of elements, and the electrodes of each element are connected by metal leads on both outer sides.
The droplet ejection device described.