JPH0747685A - Fluid connection structure and ink jet recorder employing it - Google Patents

Abstract

PURPOSE:To prevent leakage of ink and removal of tube through a simple and space saving structure at the connecting part of ink circulation system having an elastic rubber tube being fitted over a rigid pipe, and to enhance reliability in the circulation of ink by preventing or suppressing the buckling of tube in the vicinity of connecting part thus protecting the tube against external force. CONSTITUTION:When an elastic rubber tube 32 is fitted over a rigid pipe 33 to be connected therewith, a coil spring 45 having inner diameter larger than the outer diameter of the tube 32 at the free end thereof but smaller than the outer diameter of the tube 32 enlarged through insertion of the pipe 33 is further fitted over the tube 32 at the inserting part thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid connecting structure in which a rubber-like elastic tube is inserted around a rigid pipe, and an ink jet recording apparatus using the fluid connecting structure.

[0002]

2. Description of the Related Art A recording device having functions such as a printer, a copying machine and a facsimile, or a recording device used as an output device of a multifunction machine or a workstation including a computer, a word processor, etc., is a sheet or a plastic thin plate based on image information. An image (including characters and symbols) is recorded on a recording material (recording medium) such as (OHP). The recording device can be classified into an ink jet type, a wire dot type, a heat sensitive type, a thermal transfer type, a laser beam type and the like depending on the recording system of the recording means used.

In a serial type recording apparatus which employs a recording system in which a main scanning is performed in a direction intersecting a conveying direction (sub-scanning direction) of a recording material, the recording material is set at a predetermined recording position and then the recording material is set. An image (including characters, symbols, etc.) is recorded by a recording unit (recording head) mounted on a carriage that moves (main scanning) along, and after one line of recording is completed, a predetermined amount of paper is fed (sub-scan). An image is recorded in a desired range of the recording material by repeating the operation of performing (scanning) and then recording (main scanning) the image of the next row. On the other hand, in a line type recording apparatus that records a recording material only in the sub-scanning direction in which the recording material is fed in the transport direction, the recording material is set at a predetermined recording position, and one line of recording is continuously performed at one time. A predetermined amount of paper feed (pitch feed) is performed, and an image is recorded on the entire recording material.

Among them, the ink jet type (ink jet recording apparatus) is a means for recording by ejecting ink from a recording means (recording head) onto a recording material, and it is easy to make the recording means compact and high definition. Images can be recorded at high speed, plain paper can be recorded without requiring special processing, running costs are low, and the non-impact method reduces noise and uses multicolor inks. Therefore, it has an advantage that it is easy to record a color image.

As the recording means of the above-mentioned ink jet recording apparatus, there is used one which ejects the ink from the ejection port by utilizing the film boiling generated in the ink by the thermal energy generated by the electrothermal converter such as the heating element. The ink jet type recording means (recording head) for ejecting ink by using such thermal energy is used for etching, vapor deposition,
High-density liquid passage arrangement (disposition of discharge ports) by forming electrothermal converters, electrodes, liquid passage walls, top plates, etc., formed on the substrate through semiconductor manufacturing processes such as sputtering.
It is possible to easily manufacture a product having the above and further reduce the size. Further, by utilizing the advantages of IC technology and micro processing technology, it is easy to make the recording means long and planar (two-dimensional), and it is also easy to make the recording means full-multi and high-density mounting. is there.

On the other hand, as a liquid connection structure for connecting pipes in order to conduct fluid such as liquid, a structure in which a rubber-like elastic tube is inserted around the outer circumference of a rigid pipe is used. In this type of conventional fluid connection structure, the outer peripheral surface of the pipe is tightened by the elastic force of the flexible tube to achieve the hermeticity of the connection portion, or the outer circumference of the flexible tube is tightened with a band or the like. By adopting such a structure, the airtightness is achieved. Such a liquid connection structure is used as a tube connection structure of the ink circulation system of the inkjet recording apparatus.

[0007]

However, the conventional liquid connection structure and the ink jet recording apparatus using the same have the following problems to be solved. Firstly, in the structure in which the flexible tube is connected only by the elastic force, the connection portion is likely to come off when the tightening force is insufficient, and when the tube is bent near the connection portion, the connection portion is bent due to the restoring force of bending. There was an inconvenience, such as coming off.
Secondly, in the structure in which the outer circumference of the flexible tube is fastened and connected with a band or the like, fastening means for making it detachable, an operating handle, etc. are required, and the device itself is required to secure such space. There are inconveniences such as large size and disconnection of the connection part due to internal stress and plastic deformation of the tube itself after long-term use.

The present invention has been made in view of the above technical problems, and an object of the present invention is a simple and space-saving structure, which reliably prevents fluid leakage at a connecting portion and disconnection of a tube. And a fluid connection structure capable of preventing or reducing buckling of the flexible tube to improve the reliability of flow and protecting the connection portion against an external impact, and a fluid connection structure using the same An object is to provide an inkjet recording device.

[0009]

According to a first aspect of the present invention, in a fluid connection structure in which a tube of a rubber-like elastic body is inserted into the outer periphery of a rigid pipe, the outer periphery of the insertion portion of the tube is
The above object is achieved by further inserting a coil spring having an inner diameter larger than the outer diameter of the tube in a free state and smaller than the outer diameter of the tube inserted into the pipe and thickened. .

In addition to the above structure, the invention of claim 2 and claim 3 is such that the coil spring is longer than the insertion length of the tube and the pipe, or the coil spring is the insertion length of the tube and the pipe and the insertion length. The above object can be achieved more efficiently by adopting a structure having a total length of the bent portions of the tube.

According to a fourth aspect of the invention, in an ink jet recording apparatus for recording by ejecting ink from a recording means onto a recording material, a fluid connection structure in which a rubber-like elastic tube is inserted around the outer circumference of a rigid pipe is made of ink. The fluid connection structure is used for a part of a circulation system, and the fluid connection structure has an outer diameter of the tube which is larger than an outer diameter of the tube in a free state and which is thickened by being inserted into the pipe. The above object is achieved by adopting a structure having a structure in which a coil spring having a smaller inner diameter is further inserted.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic perspective view showing an embodiment of an ink jet recording apparatus suitable for applying the present invention. Figure 1
1, a plurality of (four) recording heads (recording means) 1 are mounted on a carriage 2, and the carriage 2 is guided and supported so as to be capable of reciprocating along a guide shaft 3 and a guide plate 4. The carriage 2 is reciprocally driven by a carriage motor 5 via a timing belt mechanism 9. By driving the recording head 1 in accordance with the recording information in synchronization with the reciprocating movement of the carriage 2, an image (including characters and symbols) is recorded on the recording material (recording paper or the like) 15.

When the recording for one line is completed, the recording material 15 is fed by one line by a paper feed roller (not shown) and the discharge roller 7, and the carriage is moved to the recording material 15 which is stopped. While moving 2, record the next line. Hereinafter, recording is performed on the entire area of the recording material 15 by alternately repeating the intermittent paper feeding operation and the recording operation. Reference numeral 6 is an ink cartridge as a supply source of ink to the recording head 1, and reference numeral 8 is a spur for applying a conveying force to the recording material 15 in cooperation with the paper discharge roller 7. The ink cartridge 6 is the ink supply system unit 2 provided in the main body of the apparatus.
0 (see FIGS. 3 and 4) is detachably attached.

The recording head 1 is an ink jet recording means for ejecting ink by utilizing thermal energy, and has an electrothermal converter for generating thermal energy. Further, the recording head 1 performs recording by ejecting ink from an ejection port by utilizing a pressure change caused by growth and contraction of bubbles due to film boiling caused by thermal energy applied by the electrothermal converter. Is.

FIG. 2 is a partial perspective view schematically showing the structure of the ink ejection portion of the recording means (recording head) 1.
In FIG. 2, the ejection port surface 8 that faces the recording material 15 with a predetermined gap (for example, about 0.5 to 2.0 mm).
1, a plurality of discharge ports 82 are formed at a predetermined pitch,
An electrothermal converter (heat-generating resistor, etc.) 85 for generating energy for ejecting ink is arranged along the wall surface of each liquid passage 84 that connects the common liquid chamber 83 and each ejection port 82. In this example, the recording head 1 has the ejection port 82.
Are mounted on the carriage 2 in such a positional relationship that they are arranged in a direction intersecting with the scanning direction of the carriage 2. In this way, the corresponding electrothermal converter 85 is driven (energized) based on the image signal or the ejection signal to cause the ink in the liquid passage 84 to film-boil, and the ejection port 82 is caused by the pressure generated at that time.
A recording head 1 is configured to eject ink from the recording head 1.

In FIG. 1, at a predetermined position within the moving range of the recording head 1 and outside the recording area, defective ink ejection (including non-ejection) of the recording head 1 is eliminated or normal ink ejection is maintained. A recovery system 10 is provided for this purpose. The recovery system 10 includes the ejection port surface 81 of each recording head 1.
A cap 11 for sealing (capping) the ink, a suction pump (not shown) connected to the inside of the cap 11, and the like are provided, and the suction pump is operated with the recording head 1 capped to discharge the discharge port 82. By applying a negative pressure to the ink, foreign matter such as thickened ink, air bubbles, and dust is sucked together with the ink and discharged.

In the illustrated example, four ink cartridges 6 are provided corresponding to the four recording heads 1. In the case of color recording, the four recording heads are, for example, cyan,
The ink of each color of magenta, yellow, and black is recorded, and the ink of the corresponding color is stored in each of the four ink cartridges 6. Ink of a corresponding color is supplied from each ink cartridge 6 to each recording head 1 through a supply tube 26.
The ink is supplied by, for example, capping the recording head 1 at the home position and applying a negative pressure to the ejection port 82 by the suction pump so that the ink in the ink cartridge 6 is supplied to the inside of the recording head 1 through the supply tube 26. The method is introduced in. By such ink supply, ink is filled in the recording head 1 and ink is refilled (refilled) at the time of recording.

The ink (waste ink) sucked out from the ejection port 82 by the recovery system 10 is the waste ink tube 31.
And, through the waste liquid joint 17, it is returned as waste ink to the waste ink reservoir provided in the ink cartridge 6. A wiper blade 12 for wiping and removing foreign matter such as ink and dust adhering to the ejection opening surface 81 of the recording head 1 is disposed at a position adjacent to the cap 11 by using the movement of the carriage 2. Has been done.

FIG. 3 is a schematic diagram showing the structure of the above-mentioned ink circulation system. In FIG. 3, the ink cartridge 6
When the ink cartridge is attached to the ink supply system unit 20 on the apparatus main body side, the hollow needle 21 moves the rubber plug 22 of the ink cartridge 6
And the ink in the ink bag 23 can be supplied to the recording head 1. The hollow needle 21 is a tube 2
4, through the pressure sensor 25 and the tube 26, it is connected to the sub tank 27 on the carriage 2. The pressure sensor 25 is for detecting the presence or absence of ink. The ink in the sub tank 27 is the recording head 1
Is supplied to. A separable supply joint 28 is provided in the middle of the tube 26 that connects the ink supply system unit 20 and the carriage 2.

A suction pump 30 is provided inside the recovery system 10, and the inside of the cap 11 is connected to a suction port 35 of the pump 30 via a tube 29. The discharge port 36 of the pump 30 is connected to a waste liquid absorber (waste ink reservoir) 34 in the ink cartridge 6 via a waste ink tube 31, a waste liquid joint 17, a drain tube 32 and a drain pipe 33. The waste liquid joint 17 is for detachably connecting the waste ink tube 31 and the drain tube 32. Further, the sub tank 27 on the carriage 2 is
The second of the suction pump 30 is passed through the suction tube 37.
Is connected to the suction port 38.

According to the ink circulation system shown in FIG. 3, when the ejection port surface 81 of the recording head 1 is capped and the suction pump 30 is operated, the ink is sucked from the recording head 1 through the cap 11 and recovered. In addition to performing the operation, by sucking the ink in the sub tank 27 through the suction tube 37, it functions to keep the ink level (water level) in the sub tank 27 constant and maintain good recording. The ink sucked by the pump 30 is
It is guided to the waste liquid absorber 34 in the ink cartridge 6 through the waste ink tube 31, the drain tube 32, and the drain pipe 33.

In the structure of FIG. 3, after moving the carriage 2 to a recovery position (normal home position) outside the recording area, the drive force of the drive motor 40 of the recovery system 10 drives the cap 11 forward to drive the recording head 1. Further, the pump 30 is actuated by the driving force of the drive motor 40 to generate a negative pressure, and the negative pressure causes a recovery operation of the ink ejection failure of the ejection port 82 and the ink filling into the recording head 1. And so on.

FIG. 4 shows the ink supply system unit 20 shown in FIG.
FIG. 3 is a schematic perspective view showing the ink circulation path and the ink cartridge 6 separated from each other. In FIG. 4, when each ink cartridge 6 is attached to the ink supply system unit 20, each hollow needle 21 on the unit 20 side penetrates the rubber plug 22 of each ink cartridge 6 to enable ink supply. . The hollow needle 21 is connected to the supply joint 28 via a tube 24, a first rubber joint 41, a pressure sensor 25, a second rubber joint 42, and a link pipe 43 forming a part of the tube 26. There is. The ink circulation from the supply joint 28 to the recording head 1 and the recovery system 10 is as described above. The portion of the tube 26 between the supply joint 28 and the sub tank 27 is made of a flexible tube.

On the other hand, the waste ink (waste liquid) discharged from the suction pump 30 of the recovery system 10 is guided from the waste ink tube 31 shown in FIG. 3 through the waste liquid joint 17 to the drain tube 32. The drain tube 32 is formed of a (flexible) tube of a rubber-like elastic body such as silicon rubber having flexibility and elasticity. The other end of the rubber-like elastic drain tube 32 is inserted and connected to the outer periphery of the drain pipe 33. The drain pipe 33 is made of a rigid pipe such as a rigid plastic or metal, and is provided in the ink supply system unit 20. The other end of the rigid drain pipe 33 reaches the waste liquid absorber 34 (FIG. 3) inside the waste liquid window 44 of the ink cartridge 6 mounted in the unit 20.

Therefore, a rigid pipe (drain pipe)
The connection structure (fluid connection structure) in which the rubber-like elastic tube (drain tube) 32 is inserted into the outer circumference of the tube 33 is larger than the outer diameter of the tube 32 in the free state, and Pipe 33
The coil spring 45 having an inner diameter smaller than the outer diameter of the tube 32, which is thickened by being inserted into, is further inserted. As the material of the coil spring 45, any material can be selected as long as it functions as a coil spring, such as a metal wire material for spring or a rigid plastic.

In FIG. 4, the rubber-like elastic drain tube 32 is bent in a U-shape as shown in the drawing in the vicinity of the connection portion with the drain pipe 33 in order to compact the apparatus body. As described above, the inner diameter of the coil spring 45 is set to be smaller than the outer diameter of the drain tube 32 which is inserted into the outer periphery of the drain pipe 33 and elastically deforms to have a large outer diameter. Therefore, by inserting the coil spring 45 into the outer periphery of the insertion portion of the drain tube 32, the coil spring 45 exerts a tightening force in this portion, and functions as a retaining spring for the drain tube 32.

Further, the coil spring 45 has a range of a connection portion (insertion portion) between the drain tube 32 and the drain pipe 33 and a bent portion of the drain tube 32.
It has a length to be attached to the outer circumference of the drain tube 32. By thus setting the length of the coil spring 45 to a dimension including the bent portion near the connection portion, it is possible to prevent buckling of the drain tube 32 using the resilience of the coil spring 45, and to distribute (circulate). ) Reliability can be secured.

According to the embodiment described above, it is possible to easily improve the adhesion between the tube and the pipe and the prevention force thereof by simply mounting the inexpensive coil spring 45 on the insertion portion of the tube 32 and the pipe 33. Therefore, the reliability of the connection portion can be improved at low cost. As a result, it is possible to prevent ink leakage (liquid leakage) from the connecting portion. Furthermore, it is possible to prevent the tube 32 from buckling, which not only improves the reliability of the ink distribution, but also further saves space and costs. Further, the length of the coil spring can be attached as a guide without attaching a mark or the like to the tube 32, and the cost can be reduced by improving the process. Further, by mounting the coil spring 45, it is possible to protect the tube 32 from an external force or impact.

In the above-described embodiment, the coil spring 45 is attached to each of the plurality of tubes 32, but instead of this, the coil spring 45 is attached at a portion where the plurality of tubes are combined into one tube. Alternatively, the structure may be such that a plurality of tubes are prevented from coming off by a single coil spring. Further, in the above-described embodiment, a compression type coil spring having an inner diameter smaller than the outer diameter of the inserted tube 32 is used, but a contact type coil spring may be used depending on the case.

In the above embodiment, the case of the serial recording method in which the recording means is moved in the main scanning direction has been described as an example. However, the present invention covers the entire width or a part of the recording material. The same can be applied to the case of the line recording method in which the line recording means is used to perform recording only in the sub-scan, and the same effect can be achieved. Further, the present invention is not limited to the case of color recording using a plurality of recording means for recording with different colors, but also gradation recording using a plurality of recording means for recording with the same color and different density, or recording with one recording means. The same effect can be applied to the single-color recording, and further, the recording in which these are combined, and the same effect can be achieved.

The present invention can be applied to an ink jet recording apparatus using a recording means (recording head) using an electromechanical transducer such as a piezo element, but among others, thermal energy is used. Then, an excellent effect is brought about in an ink jet recording apparatus which uses a recording means of a method of ejecting ink. This is because such a system can achieve high density recording and high definition recording.

Regarding the typical structure and principle thereof, see, for example, US Pat. Nos. 4,723,129 and 4740.
This is preferably done using the basic principles disclosed in 796. This method can be applied to both the so-called on-demand type and the continuous type, but particularly in the case of the on-demand type, a liquid (ink) is used.
By applying at least one drive signal to the electrothermal converter arranged corresponding to the sheet or liquid path in which is stored, which corresponds to the recorded information and causes a rapid temperature rise exceeding nucleate boiling. , Generates heat energy in the electrothermal converter to cause film boiling on the heat acting surface of the recording means (recording head), and as a result, bubbles can be formed in the liquid (ink) in a one-to-one correspondence with this drive signal. So effective.

Due to the growth and contraction of the bubbles, the liquid (ink) is ejected through the ejection openings to form at least one droplet. It is more preferable to make the driving signal into a pulse shape because bubbles can be grown and contracted immediately and appropriately, and thus a liquid (ink) with excellent responsiveness can be ejected. As this pulse-shaped drive signal, US Pat.
Those described in US Pat. Nos. 4,633,359 and 4,345,262 are suitable. Incidentally, US Pat. No. 43131 of the invention relating to the rate of temperature rise of the heat acting surface
If the conditions described in the specification of No. 24 are adopted, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the discharge port, the liquid passage and the electrothermal converter (the linear liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned respective specifications. US Pat. No. 4,558,333, US Pat. No. 4,558,333, which discloses a configuration in which a heat acting portion is arranged in a bending region.
A configuration using the specification of No. 459600 is also included in the present invention. In addition, Japanese Laid-Open Patent Publication No. 123670/1984 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy. The present invention is also effective as a structure based on Japanese Patent Laid-Open No. 138461/1984, which discloses a structure in which the discharge section is associated with the discharge section. That is, according to the present invention, recording can be reliably and efficiently performed regardless of the form of the recording head.

Further, as described above, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording material (recording medium) which can be recorded by the recording apparatus. . As such a recording head,
Either a structure that satisfies the length by combining a plurality of recording heads or a structure as one recording head integrally formed may be used. In addition, even with the serial type as in the above example, the recording head fixed to the device main body,
Alternatively, a replaceable chip-type recording head that can be electrically connected to the device body and supply ink from the device body when mounted on the device body, or an ink tank is integrally provided on the recording head itself. The present invention is also effective when the cartridge type recording head described above is used.

Further, it is preferable to add recovery means, preliminary auxiliary means, etc. to the recording head provided as a constitution of the recording apparatus in the present invention because the effect of the present invention can be further stabilized. If you list these specifically,
Capping means, cleaning means, pressurizing or suctioning means, electrothermal converter or other heating element or preheating means by a combination thereof, and ejection different from recording are applied to the recording head. Performing the preliminary ejection mode is also effective for stable recording.

As described above, regarding the type and number of recording heads to be mounted, for example, only one is provided corresponding to a single color ink, or a plurality of recording colors and densities are different. A plurality of inks may be provided corresponding to the ink. That is, for example, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but may be either the recording head is integrally configured or a combination of a plurality of recording heads may be used. The present invention is extremely effective for an apparatus provided with at least one of color colors or full colors by color mixing.

In addition, in the above-described embodiments of the present invention, the ink is described as a liquid, but it is an ink that solidifies at room temperature or lower and that softens or liquefies at room temperature, or an ink jet. In the method, the temperature of the ink itself is generally adjusted within a range of 30 ° C. or higher and 70 ° C. or lower to control the temperature of the ink so that the viscosity of the ink is within a stable ejection range. It may be in a liquid form. in addition,
Whether the temperature rise due to thermal energy is positively used as the energy for changing the state of the ink from the solid state to the liquid state, or the ink that solidifies when left standing for the purpose of preventing evaporation of the ink is used. In any case, the ink is liquefied by applying the thermal energy according to the recording signal and the liquid ink is ejected,
The present invention is also applicable to the case of using an ink that has a property of being liquefied only by thermal energy, such as one that has already started to solidify when it reaches the recording medium.

The ink in such a case is disclosed in JP-A-54-54.
As described in JP-A-56847 or JP-A-60-71260, a mode in which it is held as a liquid or a solid in the recesses or through holes of the porous sheet and faces the electrothermal converter. May be In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, as a form of the ink jet recording apparatus according to the present invention, in addition to the one used as an image output terminal of information processing equipment such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmitting / receiving function. And the like may be used.

[0041]

As is apparent from the above description, according to the invention of claim 1, in the fluid connection structure in which the tube of the rubber-like elastic body is inserted into the outer periphery of the rigid pipe, the outer periphery of the insertion portion of the tube is Since a coil spring having an inner diameter larger than the outer diameter of the tube in a free state and smaller than the outer diameter of the tube thickened by being inserted into the pipe is further inserted, the connection is simple and space-saving. Provided is a fluid connection structure capable of reliably preventing fluid leakage in a portion and disconnection of a tube, improving reliability of distribution, and protecting the connection portion against impact from the outside. It

According to the inventions of claims 2 and 3,
In addition to the above configuration, the coil spring has a configuration longer than the insertion length of the tube and the pipe, or the coil spring has a total length of the insertion length of the tube and the pipe and the length of the bent portion of the tube. Since it is configured, it is possible to reliably prevent fluid leakage at the connection part and disconnection of the tube with a simple and space-saving structure, and to prevent buckling of the flexible tube and improve distribution reliability. A fluid connection structure that can protect the connection portion against external impacts can be provided.

According to the invention of claim 4, in the ink jet recording apparatus for recording by ejecting ink from the recording means to the recording material, the fluid connection structure in which the tube of the rubber-like elastic body is inserted into the outer circumference of the rigid pipe. The fluid connection structure is used for a part of an ink circulation system, and the fluid connection structure is provided on the outer circumference of the insertion portion of the tube, which is larger than the outer diameter of the tube in a free state and which is thickened by being inserted into the pipe. Since it has a structure in which a coil spring having an inner diameter smaller than the outer diameter is further inserted, it is possible to reliably prevent ink leakage at the connection portion and disconnection of the tube with a simple and space-saving structure, and to prevent ink circulation. Ink with an ink circulation system that can improve reliability and protect the connection from external shocks Jet recording apparatus is provided.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an inkjet recording apparatus suitable for applying the present invention.

FIG. 2 is a partial perspective view schematically showing the structure of an ink ejection portion of the recording means in FIG.

FIG. 3 is a schematic view illustrating the configuration of an ink circulation system of an inkjet recording apparatus suitable for applying the present invention.

FIG. 4 is a schematic perspective view showing an embodiment in which the fluid connection structure according to the present invention is applied to the ink circulation system of FIG.

[Explanation of symbols]

 1 Recording Means (Recording Head) 2 Carriage 3 Guide Shaft 5 Carriage Motor 6 Ink Cartridge 7 Paper Ejection Roller 10 Recovery System 11 Cap 12 Wiper Blade 15 Recorded Material 17 Waste Liquid Joint 20 Ink Supply System Unit 21 Hollow Needle 22 Rubber Plug 23 Ink Bag 25 Pressure sensor 26 Supply tube 27 Sub-tank 28 Supply joint 30 Suction pump 31 Waste ink tube 32 Drain tube 33 Drain pipe 34 Waste liquid absorber 37 Suction tube 40 Drive motor 44 Waste liquid window 45 Coil spring 81 Discharge port surface 82 Discharge port 84 Liquid path 85 Electrothermal converter

Claims (6)

[Claims] 1. A fluid connection structure in which a tube of a rubber-like elastic body is inserted into the outer circumference of a rigid pipe, and the outer diameter of the insertion portion of the tube is larger than the outer diameter of the tube in a free state and is inserted into the pipe. A fluid connection structure characterized by further inserting a coil spring having an inner diameter smaller than the outer diameter of the thickened tube. 2. The fluid connection structure according to claim 1, wherein the coil spring is longer than the insertion length of the tube and the pipe. 3. The fluid connection structure according to claim 2, wherein the coil spring has a total length of the insertion length of the tube and the pipe and the length of the bent portion of the tube. 4. In an ink jet recording apparatus for recording by ejecting ink from a recording means to a recording material, a fluid connection structure in which a tube of a rubber-like elastic body is inserted into the outer circumference of a rigid pipe has a part of an ink circulation system. The fluid connection structure has an inner diameter larger than the outer diameter of the tube in the free state and smaller than the outer diameter of the tube thickened by being inserted into the pipe. An ink jet recording apparatus having a structure in which the coil spring is further inserted. 5. The ink jet recording apparatus according to claim 4, wherein the recording means is an ink jet recording means provided with an electrothermal converter that generates thermal energy used for ejecting ink. 6. The ink jet recording apparatus according to claim 5, wherein the recording means ejects the ink from the ejection port by utilizing the film boiling generated in the ink by the thermal energy generated by the electrothermal converter. .