JPS63162250A - Ink cartridge device of ink jet printer - Google Patents

Abstract

PURPOSE:To enable the variation in fluidity of ink and dilution liquid to be controlled to a low level with almost no change of the bending resistance of a tank even at a low temperature, by utilizing a polyester elastomer as the material of the tank. CONSTITUTION:The material of tanks 26a, 26b is elastomer of the polyester system. Therefor, its bending resistance is scarcely changed even at a low temperature and the variation in fluidity of ink 27a and dilution liquid 26 can be controlled to a low level. Further, because the bottom part 33a of a rubber stopper 33 extrudes conically to the inside of the tanks 26a, 26b, the internal pressure of the ink 27a in the tank 26a and of the dilution liquid 27b in the tank 26b always acts in the central direction. Further, because the central part of said bottom part 33a is thin in wall thickness, its action of internal pressure increase. Therefore, even through for example, cracks occur at the bottom part 33a, they can not immediately be closed. Further, even through hollow needles 35a, 35b are pulled out, no pulled out hole remains thereafter and said hole is instantly sealed.

Description

[Detailed description of the invention] Goshu division disaster The present invention relates to an inkjet printer.

Load the ink cartridge removably into the carriage,
The present invention relates to an ink cartridge device in which a hollow needle is inserted into a rubber stopper of a bellows-shaped tank in the ink cartridge to drain ink or its diluted liquid from the tank.

As this type of ink cartridge device, the applicant of Saramai and Arashi,
Inside the ink cartridge, a bellows-shaped ink tank and a diluent tank are placed side by side, and these are constantly pressurized from above with springs.The ink cartridge is mounted on a carriage, and a hollow hole is inserted at the bottom of each tank's rubber stopper. Stick the needle in.

A structure has already been provided in which the valve seat at the lower end of the hollow needle is opened when necessary to allow ink or diluent in the tank to flow into the main ink tank on the carriage side through the hollow needle.

In this device, the diluent (preservative added to pure water) is used to adjust the viscosity when the water in the ink evaporates and the viscosity increases. The ink viscosity in the main ink tank inside the carriage is detected by a viscosity sensor, and when the viscosity reaches a predetermined value (for example, water evaporation rate is 20%), the valve seat is automatically opened to maintain a constant level. It is supposed to be done only on time.

Therefore, since the replenishment time is constant, when the diluent in the dilution tank decreases and the tank contracts,
Because the spring force of the spring that pressurizes it becomes weaker, the amount of dilution will change between the initial and final times (the diluent tank will be empty).
The flow rate (cc/5ee) varies, and the ink concentration in the main ink tank in the carriage changes.

In this case, the ink droplet formation effect of the recording head changes, resulting in poor print quality. Therefore, it is desirable that there be no fluctuation in the supply flow rate of the diluent.

Figure 6 shows that as the diluted liquid flows out of the tank, the spring force (pressure force) of the spring weakens, and conversely, since the tank is bellows-shaped, its bending resistance (repulsion force) increases, and the effective pressurizing force on the diluted liquid This shows that the change in flow rate causes fluctuations in the outflow flow rate. This increases as the tank becomes less flexible at lower temperatures.

In order to reduce this kind of influence as much as possible.

Although it is possible to lower the spring force (gr/m) of the spring in advance, there is a limit and it is not practical.

Therefore, it is important to select the material of the tank.

Therefore, in the past, relatively flexible low-density polyethylene was generally used as a material for tanks, but as shown in Figure 6, this has high bending resistance at low temperatures and suffers from fluid fluctuations at low temperatures. There was a downside to getting bigger.

Purpose An object of the present invention is to make a tank made of a material that exhibits less deterioration in flexibility even at low temperatures.

Structure According to one aspect of the present invention, the material of the tank is a polyester elastomer.

The main features of polyester elastomers are as follows.

■ Its flexibility hardly changes from low to high temperatures,
Wide usable temperature range.

■ High load capacity and low creep.

■ Extremely high bending fatigue resistance.

■ Excellent oil sealing and chemical resistance.

■ Good moldability.

Next, embodiments of the present invention will be described based on the drawings.

FIG. 2 shows an inkjet printer in which a portion related to the present invention is shown in cross section. The carriage (10) is slid parallel to the platen (13) along the guide rod (11) and guide rail (12). The carriage (10)
is made by laminating many members, and has a main ink tank (14) inside and a recording head (15) on the top.
) and deflection 1ts (16).

The ink (17) in the main ink tank (14) is supplied to the recording head (15) through an ink supply passage (18) by a pump (not shown).
) is ejected as ink particles (20) from a nozzle (19) at the tip of the ink droplet (20), deflected by a deflection electrode (16), and sprayed onto the paper (21) on the platen (13). Excess ink particles (20) are received by the gutter (22), collected from the ink collection passageway (23) into the main ink tank (14), and ejected again.

The ink cartridge (24) is removably loaded onto the carriage (10), and its cartridge case (25)
) is integrally molded with synthetic resin, and the cartridge case (
25), two cylindrical guide ribs (25a) and (25b) are provided vertically in parallel as shown in FIGS. 3 and 4. Then, one guide rib (2
Inside 5a) is a bellows-shaped ink tank (2) that contracts.
6a), and a diluent tank (26b) which similarly contracts in the shape of a bellows is accommodated in the other guide rib (25b). The vertical movement of these tanks due to contraction is guided by respective guide ribs. Ink (27a) is in the ink tank (26a).
is enclosed, and a diluent is enclosed in the diluent tank (26b).

These tanks (26a) and (26b) are both molded from polyester elastomer. These tanks are housed within their respective guide ribs (25a) and (25b), but the storage structure is the same.

Now, regarding the structure of the ink tank (26a), as shown in FIG. 1, the tank (26a) is pressed from above by a spring (28).

A stepped portion (29a) is provided inside the proximal end portion of the outflow portion (29) that protrudes from the tank (26a), and the outflow portion (29)
A male thread (30) is formed on the outer circumferential surface of 29).

The male screw (30) is connected to the cartridge case (2).
5) is screwed into the female thread (32) of the protrusion part (31) on the bottom surface. A stepped portion (31a) is provided inside the tip (lower end) of this protrusion portion (31). A cap-shaped rubber stopper (33) is fitted into the outflow part (29), and the rubber stopper (33) screws the outflow part (29) into the protrusion part (31) as described above. As a result, it is held between the step portions (29a) and (31a) from both upper and lower sides.

The bottom (33a) of the rubber stopper (33) is connected to the tank (26a).
The bottom part (33a
) is thinner than its outer circumference,
A truncated conical recess (33b) is formed on the lower surface of the bottom (33a).

On the other hand, on the carriage (10) side, as shown in FIG. 3, four parts (314a) and (34b) corresponding to both tanks (26a) and (26b), respectively, are formed on the upper surface, and the recessed part (34a) ' Hollow needles (35a) and (35b) are vertically protruded from the center of (34b), respectively.

The ink cartridge (24) is mounted on the carriage (lO), and the protrusion part (
31) on the carriage (10) in each of the ink tank (26a) and the diluent tank (26b).
When fitted into the recesses (34a) and (34b), the hollow needles (35a) and (35b) fit into the ink tank (35a) and (35b), respectively.
26a) and the rubber stopper (3) of the diluent tank (26b).
3) is guided to the truncated conical recess (33b) and penetrates into the center of its bottom (33a). At this time, the bottom (33
Since the central portion of a) is thinner than its outer peripheral portion, it is easy to pierce the hollow needles (35a) and (35b). In addition, the rubber stopper (33) is connected to the tank (26a).
・The stepped part (29a) of (26b) and the cartridge case (
Since the hollow needles (35a) and (35b) are inserted and removed, the outflow portion (2
9) Prevents it from coming off. If the male screw (30) and the female screw (32) are taper screws, the rubber stopper (33) is tightened from the periphery by the outflow portion (29), thereby improving the sealing performance between them.

In this way, the hollow needles (35a) and (35b) are connected to the rubber stopper (3
The hollow needle (3) is inserted through the bottom (33a) of the hollow needle (3).
The lower ends of 5a) and (35b) are connected to the valve seat (3) shown in FIG.
6), the ink (27a) in the tank (26a) or the diluent (27b) in the tank (26b)
) is injected into the main ink tank (14) through the hollow needles (35a) and (35b). Tank (26a)・
(26b) is guided by the respective guide ribs (25a) and (25b) in its vertical movement due to its expansion and contraction, so it does not tilt.

Therefore, ink (27a) and diluent (27b)
The outflow is carried out smoothly. Moreover, since the material of these tanks (26a) and (26b) is polyester elastomer, the bending resistance hardly changes even at low temperatures as shown in FIG. Fluctuations in flow can be kept low.

In addition, the bottom (33a) of the rubber stopper (33) is connected to the tank (26).
a) and (26b), so that the ink (27a) in the tank (26a) and the tank (2
The internal pressure of the diluent (27b) in 6b) is always applied toward the center of the bottom (33a), and since the center of the bottom (33a) is thinner, the internal pressure effect increases.

Even if a crack occurs in the bottom (33a), it is immediately closed, and even when the hollow needles (35a) and (35b) are pulled out, the hole is immediately sealed without leaving a hole.

Effects According to the present invention, polyester elastomer is used as the material for the bellows-shaped tank.

The bending resistance of the tank hardly changes even at low temperatures, and fluctuations in the flow of ink and diluent can be suppressed to a low level.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a portion of an ink cartridge device according to the present invention, FIG. 2 is a cross-sectional view of an inkjet printer to which the same is applied, FIG. 3 is a cross-sectional view of a portion of the ink cartridge and carriage side, and FIG. 4 is a horizontal sectional view of the ink cartridge. Also. Figures 5 and 6 are graphs showing the relationship between the spring force of the spring and the repulsive force of the bellows-shaped tank. This is the case of a conventional example using . (10)... Carriage (24)...
...Ink cartridge (26a) ...
- Ink tank (26b)... Diluent tank (27a)... Ink (27b)... Diluent

Claims (1)

[Claims] The ink cartridge is removably loaded into the carriage and has a bellows-shaped tank filled with ink or its diluted liquid, and the tank is constantly pressurized with a spring.
An ink cartridge device for an ink jet printer in which ink or diluted liquid flows out by piercing a hollow needle into a rubber stopper of the tank, wherein the tank is made of a polyester elastomer.