JPS622309Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a pressurized liquid supply device used in color inkjet printers and the like.

[Conventional technology]

FIG. 2 is a front cross-sectional view of a conventional ink pressure liquid supply device for an inkjet printer.

In FIG. 2, a pump section 10 that sucks and discharges ink is provided with a solenoid 11, an accumulator 12, a pressure regulating valve 13, and a solenoid valve 14 corresponding to the cut-off valve 7 in FIG. 1 (described later). ing.

The operation of this conventional ink pressure liquid supply device is such that, when a solenoid 11 is driven, a pump portion 10 sucks ink from an ink reservoir (not shown), pressurizes the sucked ink, and discharges it. The accumulator 12 functions to smooth the pressure pulsations of the discharged ink pressure, and the pressure regulating valve 13 functions to adjust the pressure of the discharged ink to a predetermined constant pressure. There is.

The ink pressure liquid supply device shown in FIG. 2 requires one ink pressure liquid supply device for each color of ink.

Furthermore, an ink jet printer that performs color printing requires a total of four types of ink: three primary color inks and black ink.

Therefore, an ink pressure liquid supply apparatus for an ink jet printer for performing such color printing requires as many as four ink pressure liquid supply apparatuses as shown in FIG.

[Problem that the invention attempts to solve]

However, as is clear from FIG. 2, both a large solenoid 11 and a pressure regulating valve 13 are required for the pump portion 10 with a small displacement volume, and the solenoid 11 and pressure regulating valve 13 are of different colors. An ink pressure liquid supply device with a solenoid 11 and a pressure regulating valve 13 is required for each type of ink.

Considering the current situation in which ink jet printers are currently being used in places with limited space such as offices, and in the future,
Considering that it will be used in further development,
There are drawbacks to using a conventional ink pressure liquid supply system, such as that in FIG. 2, in such color ink jet printers.

The purpose of this invention is to eliminate the above-mentioned difficulties in miniaturization, and to contribute to the miniaturization and weight reduction of inkjet printers for printing other colors, etc., which can maintain a stable and constant fluid pressure. An object of the present invention is to provide a pressurized liquid supply device that provides high pressure liquid.

[Means for solving problems]

The configuration of the present invention is as follows.

The displacement container is separated into a displacement chamber and one displacement chamber by a piston body, and the piston body is disposed inside the displacement container so as to be movable in a direction to compress or expand the displacement chamber, The displacement chamber is connected to a reservoir via a suction valve, and the first displacement chamber has a working pressure of:
A piping line for a working fluid that changes alternately from atmospheric pressure to a constant high pressure or vice versa is connected, and a spring is installed in the displacement chamber, and the biasing force of the spring acts on the piston body. acting in a direction to expand the displacement chamber; the other displacement container is separated into one displacement chamber and the other displacement chamber by another piston body; The other displacement chamber is connected to the discharge pipe via a cut-off valve, and the one displacement chamber includes: A working fluid in which the height of the working pressure alternates from atmospheric pressure to a constant high pressure or vice versa, and the alternating changes are in phase with the change in the working pressure in the one displacement chamber. the other displacement chamber is arranged above the displacement chamber in the direction of gravity, and a discharge valve is interposed between the other displacement chamber and the displacement chamber in the direction of gravity. .

It consists of the above structure.

[Effect]

The effects of the configuration of the present invention described above are as follows.

When a working fluid at a constant pressure is applied to one displacement chamber, the pressure of the working fluid presses the piston body against the urging force of the spring and compresses the displacement chamber. The fluid such as ink is supercharged into the other displacement chamber by opening the discharge valve.

Conversely, when the working fluid in one displacement chamber is released to the atmosphere, the spring presses the piston body by its biasing force and expands the displacement chamber. As a result, the fluid such as ink in the reservoir is pressed by atmospheric pressure and pushes open the suction valve through the suction pipe, and the fluid fills into the displacement chamber.

Once the filling is completed, the cycle is then repeated, followed by another compression step of the displacement chamber.

In response to the action of the displacement container described above, when fluid such as ink from the displacement chamber is supercharged into the other displacement chamber as described above, since one displacement chamber is open to the atmosphere, the other displacement chamber is expands due to the supercharging, and when the supercharging ends, a constant pressure of working fluid is applied to one displacement chamber, and as a result, the constant working pressure causes the other piston body to The other displacement chamber is pressed in a direction to compress it, and as a result of this pressing, fluid such as ink in the other displacement chamber opens the cut-off valve and is discharged into the discharge pipe. Note that at this time, the discharge valve is closed by the ink pressure in the other displacement chamber.

In the above pump action, the other displacement chamber is arranged above the displacement chamber in the direction of gravity, and a discharge valve is interposed between the other displacement chamber and the displacement chamber in the direction of gravity. '', the fluid such as ink sucked through the suction pipe and the suction valve is sequentially discharged from below in the direction of gravity into the discharge pipe through the displacement chamber, the discharge valve, and the other displacement chamber. I'm going to go.

Therefore, during the first pump operation, the air initially accumulated in any part from one displacement chamber to the other displacement chamber is discharged into the discharge pipe along with the ink or other fluid due to its buoyancy. As a result, in the subsequent pump action, ink or the like mixed with air will not be blown out from the discharge pipe.

〔Example〕

The present invention will be described below based on examples.

FIG. 1 shows a side sectional view of a pressure liquid supply device as an embodiment of the present invention.

The displacement chamber 5b formed in the body 1 and the displacement chamber 5a formed in the side body 2 constitute the displacement container 5, and the body 1 and the side body 2 are integrally fastened with bolts (not shown). I'm wearing it.

The diaphragm 5d is clamped between the body 1 and the side body 2 in a sandwich shape.
A piston body 5c is fastened to the piston body 5c, and the piston body 5c has a shape with a concave space on the side of the displacement chamber 5b.

A nipple 4 is screwed onto the side wall of the displacement chamber 5b, and a tapered seat 9d is cut into the right end of the suction conduit 4a bored in the nipple 4, and the seat 9d receives the biasing force of a spring 9c. The ball 9a is pressed by the spring 9c, and the spring seat 9b of the spring 9c
d, the spring seat 9b and the piston body 5c abut against the side wall of the displacement chamber 5b.
The spring seat 9b is fixed to the body 1 by the urging force of the spring 5f sandwiched between the springs 5f and 5f, and the spring 5f pushes the piston body 5c into the displacement chamber 5.
It gives an auxiliary force to side A.

The spring 5f also has a centering function so that the piston body 5c is located at the center of the displacement container 5 in the radial direction.

A pressure oil pipe whose operating pressure alternately changes from atmospheric pressure to a constant pressure or vice versa communicates with the displacement chamber 5a, and the suction pipe 4a communicates with an ink reservoir (not shown).

Between the body 1 and the side body 2, a diaphragm 6
d is sandwiched between the diaphragms 6d
On the left and right of the
The diaphragm 6d is provided with a piston body 6c.
The piston body 6c is fitted in a displacement chamber 6a cut into a cylindrical shape so as to be able to slide in the axial direction thereof, and the displacement chambers 6a and 6b constitute a displacement container 6.

A discharge valve 8 is interposed between the displacement chamber 5b and the displacement chamber 6b, the discharge valve 8 is located above the displacement chamber 5b in the direction of gravity, and the displacement chamber 6b is located further above the discharge valve 8. are doing.

A diaphragm 3 is provided between the side body 3 and the body 1.
a is sandwiched in a sandwich-like manner, and the diaphragm 3a
A chamber 3c is provided on the right side of the chamber 3c, and a discharge pipe 1b is connected to the chamber 3c.
The chamber 3c, the diaphragm 3a, the spring 3b, and the hole 1a are connected to the cut-off valve 7.
It consists of

A pipe (not shown) is connected to the discharge pipe 1b, and the pipe is connected to a nozzle in an inkjet printer (also not shown), and the displacement chamber 6a is connected to a nozzle (not shown) of an inkjet printer. A hydraulic pressure is provided that changes the pressure in the opposite phase to the change in pressure.

The operation of the above configuration will be explained below.

When a working fluid at a constant pressure is applied to the displacement chamber 5a, the pressure of the working fluid pushes the piston body 5c to the left against the biasing force of the spring 5f, compressing the displacement chamber 5b, and causing the compression. As a result, the discharge valve 8 is opened, and the ink in the displacement chamber 5b is supercharged into the displacement chamber 6b. At this time, the suction valve 9 is closed by the ink pressure in the displacement chamber 5b.

Conversely, when the working oil pressure in the displacement chamber 5a is lowered to atmospheric pressure, the spring 5f presses the piston body 5c to the right by its biasing force and expands the displacement chamber 5b. As a result, the ink in the reservoir is pressed by atmospheric pressure and pushes open the suction valve 9 through the suction pipe 4a, and the ink fills into the displacement chamber 5b.

When the filling is completed, the displacement chamber 5b is then refilled.
The cycle is repeated, followed by a compression step.

In response to the action of the displacement container 5, when the displacement chamber 6b is supercharged with ink from the displacement chamber 5b as described above, since the displacement chamber 6a is open to the atmosphere, the displacement chamber 6b is When the supercharging is completed, pressurized oil at a constant pressure is applied to the displacement chamber 6a, and as a result,
Due to the constant operating pressure, the piston body 6c is pressed in the direction of compressing the displacement chamber 6b, and due to this pressing, the ink in the displacement chamber 6b is
Increase the pressure of c. Note that, at this time, the discharge valve 8 is closed by the ink pressure in the other displacement chamber 6b.

When the pressure of the ink in the chamber 3c reaches a predetermined value, the pressure overcomes the urging force of the spring 3b and pushes the diaphragm 3a to the left, causing the chamber 3
The ink c is ejected from a nozzle (not shown) at the tip of the ejection line through the perforation 1a and the ejection line 1b.

The ejected ink is controlled, and ejected particles of the controlled ink adhere to desired positions on the paper to print on the paper.

This pressure liquid supply device operates as described above, and in the above operation, a spring such as the spring 5f of the displacement container 5 is installed in the displacement container 6 to provide self-sufficiency to the displacement container 6 itself. The reason why the displacement container 5 is supercharged with ink without causing it to hold the ink is based on the following reason.

Assuming that the displacement chamber 6b is provided with a spring to bias the piston body 6c to the right, and the displacement container 6 is provided with the function of self-supplying ink, after the self-supply, the displacement chamber 6a is When the displacement chamber 6b is compressed by increasing the operating pressure, the internal spring increases its resistance in proportion to the amount of compression due to the nature of the spring.

In this case, by applying a constant working pressure to the displacement chamber 6a, a pressing force is generated in the piston body 6c due to the working pressure, and the pressing force compresses the displacement chamber 6b. , the drag force of the spring cancels out the pressing force,
Moreover, the countervailing force increases in proportion to the amount of compression.

As a result, since the operating pressure generated in the displacement chamber 6b is determined by the pressing force generated in the piston body 6c, the pressing force is reduced by the cancellation, and the ink generated in the displacement chamber 6b is reduced. The pressure becomes lower as the amount of compression increases.

This means that the pressure ejected from the nozzle changes in proportion to the amount of compression, which is an undesirable result in improving printing on paper.

For the above reasons, the self-sufficiency mechanism is removed from the displacement container 6, and the displacement container 5 for supercharging is provided instead to supercharge ink, and the piston body 6c generates almost no resistance force. The configuration of the diaphragm 6d is such that a constant operating pressure in the displacement chamber 6a acts on the piston body 6c.

That is, the piston body 6c is disposed in the displacement chamber 6a.
The pressure oil in the displacement chamber 6b and the ink liquid in the displacement chamber 6b are simply separated so that they do not mix, and as a result, the constant pressure generated in the displacement chamber 6a becomes the ink pressure in the displacement chamber 6b. It is something that exists.

Furthermore, the reason why the piston body 6c is driven not mechanically but by fluid drive is as follows.

That is, in a multicolor inkjet printer, it is necessary to pressurize various types of ink independently and eject them from independent nozzles.

For example, in order to make color printing possible, it is necessary to prepare a total of four types of ink, including three types of ink of the three primary colors and black ink, and each of these requires the pressure liquid shown in Figure 1. Four supply devices are required. However, if each of these is provided with a mechanical drive device for the piston body 6c, the entire device becomes large, making it difficult to install it in a limited space such as an office.

For the above reasons, the piston body 6c is driven by fluid, and its fluid power generation source is driven by a single device (not shown), thereby successfully reducing the size of the entire device.

After the above operations and conditions are satisfied, ink must be reliably pumped out from the discharge pipe 1b each time the displacement chamber 6b undergoes a compression process.

To this end, the present pressure liquid supply device is designed as follows.

That is, in the flow path from the suction pipe 4a to the discharge pipe 1b, the discharge valve 8 is arranged above the displacement chamber 5b in the direction of gravity, and the discharge valve 8
The configuration is such that a displacement chamber 6b is disposed above the.

As a result, from the displacement chamber 5b to the displacement chamber 6b
Even if there is air in between, due to the buoyancy of the air, the air will escape in the first stage in the direction of the discharge pipe 1b or in the direction of the air vent plug 1c, This makes it easy to extract the air.

For this reason, there is no risk of air remaining in any part after the air venting, causing the air to irregularly gush out of the nozzles during operation, causing ink output to temporarily stop.

Although the above embodiments have been explained using an inkjet printer as an example, the pressure liquid supply device of the present invention can also be used as is as a device for pressurizing other liquids other than ink. It will be easy to understand that this is the case.

[Effect of idea]

The effects of this invention are as follows:

1 By applying a constant fluid pressure to one of the displacement chambers 6a, the ink, etc. is discharged at a constant pressure, so each pressure liquid supply device itself has It is not necessary to use the large pressure regulating valve 13 used in the conventional pressure liquid supply device shown in FIG.

2 One displacement chamber 5a and one displacement chamber 6a
Since a method is adopted in which the displacement container 5 and other displacement containers 6 are driven by alternately applying atmospheric pressure and a constant fluid pressure higher than atmospheric pressure, such alternating pressure changes are output. If there is one hydraulic device, all of the pressure liquid supply devices can be driven through flexible piping without having to attach a conventional large solenoid 11 (FIG. 2) to each pressure liquid supply device.

Therefore, if the pressure liquid supply device of the present invention is used in a device that needs to discharge different types of liquids such as ink independently at the same pressure, the entire device can be made very compact. This makes it possible to flexibly separate the drive parts and freely arrange each pressure liquid supply device and drive part.

3. In particular, when the liquid discharged from the discharge pipe line 1b of the pressure liquid supply device in the present invention is used as ink for a color inkjet printer,
A single hydraulic device that alternately outputs varying pressures to each of the color inkjet printers that make up one color inkjet printer using four pressurized liquid supply devices, It becomes possible to drive a number of color inkjet printers only via hydraulic piping.

Therefore, the entire device can be made very compact, and the hydraulic devices that drive each pressure liquid supply device can be freely arranged using flexible piping, which reduces the administrative burden. It becomes easy to arrange it in a room or the like.

[Brief explanation of the drawing]

FIG. 1 shows a side sectional view of a pressure liquid supply device as an embodiment of the present invention, and FIG. 2 shows a conventional inkjet supply device.
1 shows a pressure liquid supply device for a printer in a sectional side view. The symbols used in the examples are as follows. 1...Body, 1b...Discharge pipe line, 5 and 6
...Pushing containers, 5a, 5b, 6a and 6b
...displacement chamber, 5c and 6c...piston body, 5f...spring, 7...cut-off valve,
8...Discharge valve, 9...Suction valve.

Claims (1)

[Claims for Utility Model Registration] 1. The displacement container is separated into a displacement chamber and one displacement chamber by a piston body, and the piston body is movable in a direction to compress or expand the displacement chamber. , installed in the displacement container, the displacement chamber is connected to the reservoir via a suction valve, and the first displacement chamber has an operating pressure that varies from atmospheric pressure to a constant high pressure, or vice versa. On the other hand, alternate working fluid pipes communicate with each other, a spring is disposed inside the displacement chamber, and the biasing force of the spring acts on the piston body in a direction to expand the displacement chamber, The other displacement container is separated into one displacement chamber and the other displacement chamber by another piston body, and the other piston body is movable in a direction to compress or expand the other displacement chamber. the other displacement chamber is connected to the discharge pipe via a cut-off valve, and the one displacement chamber has a working pressure that is constant from atmospheric pressure a working fluid conduit that alternately switches to a higher pressure in said one displacement chamber or vice versa, and in which said alternating changes are in opposite phase to the changes in working pressure in said one displacement chamber; The pressure liquid supply device having the above structure, wherein the chamber is disposed above the displacement chamber in the direction of gravity, and a discharge valve is interposed between the other displacement chamber and the displacement chamber in the direction of gravity. 2. The pressurized liquid supply device according to claim 1, wherein the reservoir is a part of an inkjet printer that stores ink.