JP2003080729A - Ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recorder which can surely couple a tube for constituting an ink channel and a coupling member with each other. SOLUTION: A second coupler 36 to which the flexible tube 5 is inserted and fitted has a tapering head 36a which has the maximal diameter larger than an inner diameter D1 of the tube 5 and has the diameter reduced towards a leading end, and a neck 36b continuous with the maximal diameter side of the head and having a smaller diameter than the maximal diameter. The tube 5 is fitted into the head 36a with the diameter expanded. Moreover, a length d2 of the neck 36b is constituted so that an inner periphery of the tube 5 at the side closer to an end than the head has the diameter made smaller than the maximal diameter of the head 36a towards the side of the neck 36b over a predetermined length (0.7 times of more of the inner diameter of the tube 5) in an axis direction. A resistance against a force of pulling out the tube 5 is increased accordingly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus, and more particularly to an ink jet recording apparatus capable of ensuring a connection between a tube forming an ink flow path and a connecting member.

[0002]

2. Description of the Related Art Conventionally, a tube supply type ink jet recording apparatus is known in which ink is supplied from an ink tank to a recording head through a tube. This tube supply type ink jet recording apparatus includes a recording head for ejecting ink onto a recording medium to perform recording, a carriage on which the recording head is mounted, and an ink provided outside the carriage and supplied to the recording head. And an ink tank for storing ink and a tube for supplying ink from the ink tank to the recording head.

When connecting a tube to a rigid part, a tapered projection, that is, a connecting tool is projected from the rigid part, and the tube is press-fitted to the tapered surface by utilizing its flexibility. It is used in.

[0004]

However, since the tapered surface has a shape that reduces its diameter toward the distal end side of the connector, when the carriage repeatedly reciprocates, the tube moves to the connector due to the movement of the tube. On the other hand, it is easy to loosen and may come off. Even if it does not come off, air will enter through the gap between the inner surface of the tube and the connector, and the air will form bubbles in the ink to block the ink flow path, causing defective ejection of ink in the recording head. is there.

To solve this, Japanese Patent No. 2563
As shown in FIG. 2 of Japanese Patent No. 784, the outer circumference of the tube press-fitted into the tapered surface of the connector is pressed by a cylindrical stopper member, and the stopper member can be screwed to the connector. Although conceivable, the outer diameter of the connecting portion becomes large and the device becomes large. In particular, when a plurality of tubes are lined up like a color inkjet recording apparatus, it is difficult to downsize the apparatus.

Further, in the ink jet recording apparatus, in order to prevent evaporation of water in the ink in the tube and invasion of air into the tube from the outside, the tube is made of polyethylene (PE) having low vapor permeability and gas permeability. It may be made of polypropylene (PP) or the like. Generally, these materials are hard, and when the tube is made of these materials, as compared with the case where the tube is made of a flexible material such as ethylene rubber or butadiene rubber, the adhesion with the connector is inferior, There is a problem in that air enters through the gap between the tube and the connector, and the air blocks the ink flow path, causing defective ink ejection.

The present invention has been made in order to solve the above-mentioned problems, and in particular, ink jet recording capable of ensuring the connection between the tube forming the ink flow path and the connecting member with a simple structure. The purpose is to provide a device.

[0008]

In order to achieve this object, an ink jet recording apparatus according to a first aspect of the invention is an ink flow path for supplying ink from an ink supply source to a recording head unit for ejecting ink onto a recording medium. And a flexible tube that constitutes the ink flow path, a tapered head having a maximum diameter larger than the inner diameter of the tube and having a diameter reduced toward the tip, and the maximum diameter portion side thereof. It has a neck portion that is continuous and has a diameter smaller than the maximum diameter portion, and is provided with a connecting member that constitutes the ink flow path, and while the tube is expanded and fitted to the head of the connecting member, The inner circumference on the end side over a predetermined length in the axial direction,
The length of the neck portion of the connecting member is configured so as to be smaller than the maximum diameter of the head portion toward the neck portion side.

According to the ink jet recording apparatus of the present invention, the ink of the ink supply source ejects the ink to the recording medium through the ink flow path constituted by the tube and the connecting member. Is supplied to. Here, the flexible tube is a tapered head having a maximum diameter larger than the inner diameter of the tube and having a diameter reduced toward the tip and a neck portion continuous to the maximum diameter portion side and having a diameter smaller than the maximum diameter portion. The two members are connected by being inserted into a connecting member having. Therefore, the tube is expanded and fitted to the head of the connecting member, and the inner circumference on the end side of the tube is
It is inserted into a cervical portion configured to be reduced in diameter from the maximum diameter of the head portion toward the cervical portion side over a predetermined length in the axial direction.

An ink jet recording apparatus according to a second aspect is the ink jet recording apparatus according to the first aspect,
The length of the neck of the connecting member is approximately 0.7 times or more the inner diameter of the tube.

According to a third aspect of the present invention, there is provided the ink jet recording device according to the first or second aspect, wherein the tube has a two-layer structure and one of the inner layer and the outer layer is made of a flexible material. The other is made of a material having low vapor permeability and low gas permeability.

An ink jet recording apparatus according to a fourth aspect is the ink jet recording apparatus according to the third aspect,
The one layer is made of silicone rubber, and the other layer is made of tetrafluoroethylene resin.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a plan view showing the internal configuration of an inkjet recording apparatus 1 which is an embodiment of the present invention. This inkjet recording device 1
Is a main body frame 2, a recording head unit 3 that is included in the main body frame 2 and ejects ink onto the recording paper PP, an ink tank 4 that stores ink to be supplied to the recording head unit 3, and the ink tank 4 thereof. A tube 5 for supplying ink to the recording head unit 3 from
The recovery device 6 and a transport device for transporting the recording paper PP are provided.

The main body frame 2 is made of flame-retardant plastic in a substantially box-shaped body. A rod-shaped guide rod 7 is horizontally provided in the longitudinal direction of the main body frame 2 so that the recording head unit 3 can reciprocate in a direction A (a left-right direction in FIG. 1) orthogonal to a conveyance direction B of the recording paper PP. I support you.

The recording head unit 3 includes a carriage 3a.
And a casing 3b connected to the carriage 3a, the casing 3b is formed into a substantially box shape, and a recording head (not shown), an air trap unit 11 and the like (see FIG. 2) are housed inside the casing. There is. The internal structure of the recording head unit 3 will be described with reference to FIG.

The carriage 3a is fitted on the guide rod 7 so as to be capable of reciprocating. A belt is attached to the carriage 3a, and the belt is wound around a roller attached to a carriage motor. When the carriage motor rotates, the belt wound around the roller is driven to move the recording head unit 3.

Below the recording head unit 3, a conveying roller is arranged as a conveying device for conveying the recording paper PP. The transport roller is the recording head unit 3
Located below and in front of and below the transport motor 103
Rotation of the recording sheet PP causes the recording sheet PP to move in a substantially horizontal direction (arrow B).
Transport to.

The recording head in the recording head unit 3 is
A plurality of, for example, four sets are provided side by side for full-color recording, and ink ejection ports are opened downward on the side facing the recording paper PP. Each set of recording heads distributes ink supplied from an air trap, which will be described later, into ink chambers for each ink ejection port, and ejects the ink from the ink ejection port by an actuator such as a piezoelectric element, similar to a known one. . Further, each set of recording heads is supported on the lower surface of the housing 3b of the recording head unit 3, and the surface on the recording paper PP side is covered by a cover plate except for the ink ejection ports.

The ink tank 4 is the recording head unit 3
It is for storing the ink to be supplied to the recording sheet PP and is arranged below the conveyance path of the recording sheet PP. The ink tank 4 is composed of four ink tanks 4a to 4d in which black, yellow, cyan, and magenta inks corresponding to the respective recording heads are sealed. Each ink tank 4a-4d is connected to each recording head via four tubes 5a-5d.

The recovery device 6 is a device for executing recovery processing, and is arranged on the left side portion of the main body frame 2. The recovery process is a process for recovering the ink ejection state from the recording head. The recovery device 6 includes a suction cap 6a, a suction pump (not shown) that sucks ink or the like from the recording head unit 3 through the suction cap 6a, and a wiper 6b that wipes the ink ejection port forming surface of the recording head unit 3. It is configured.

The suction cap 6a is formed in a substantially box shape, and abuts on the ink ejection port forming surface of the recording head to seal the ink ejection port forming surface. A discharge tube 6c communicates with the bottom of the suction cap 6a. The ink sucked by the action of the suction pump is discharged from the suction cap 6a through the discharge tube 6c. When the suction process is completed, the suction cap 6a separates from the ink ejection port forming surface. The ink ejection port forming surface, which is contaminated by the discharged ink, is wiped by the wiper 6b made of plate-shaped rubber, and the recovery process ends.

Next, the internal structure of the recording head unit 3 will be described with reference to FIG. FIG. 2 is a plan view showing the internal structure of the recording head unit 3. Inside the recording head unit 3, an air trap unit 11 and a joint 12 are provided.

The air trap unit 11 includes a tube 5
It is for storing the bubbles generated inside. The air trap unit 11 is formed in a substantially rectangular parallelepiped shape, and is arranged at the center of the inside of the housing 3b of the recording head unit 3.
In the air trap unit 11, four independent air bubble storage portions corresponding to the respective recording heads, that is, the air traps 3 are provided.
It is configured by being divided into 0 to 33. Further, on the rear side surface of each of the air traps 30 to 33 (upper side in FIG. 2), four connecting tools 34 for connecting with the joint member 12 are arranged in a substantially linear shape. The connector 34 is formed in a taper shape whose diameter decreases toward the joint member 12, and an ink flow path, that is, an ink inlet 11f for each air trap is formed inside.

The joint member 12 includes tubes 5a-
It is for connecting 5d and each air trap 30-33. The joint member 12 is formed in a substantially rectangular parallelepiped shape and is arranged behind the air trap unit 11 (upper side in FIG. 2). The joint member 12 has four independent ink channels 12a to 12d, and a first connector 35 for coupling to the connectors 34 of the air traps 30 to 33 is provided at both ends of each ink channel. A second connecting member 36 for connecting to the tubes 5a to 5d is provided in a protruding manner.

The first connecting member 35 includes the air traps 30-.
They are arranged in a substantially straight line on the surface of the 33 facing the connecting tool 34. The first connector 35 is composed of a neck portion protruding from the main body of the joint member 12 and a head portion that extends from the neck portion and has a tapered shape that reduces in diameter toward the connector 34. . And each 1st connection tool 35 and each corresponding connection tool 34 are the connection members 37 comprised by the substantially hollow cylindrical shape.
Are inserted and connected from both ends.

Two second connecting members 36 are provided so as to project from the left and right side surfaces of the joint member 12. Each second connector 3
6 is encapsulated and connected inside one end of each tube 5a-5d.

Here, the second connecting member 34 and the tubes 5a ...
The connection with 5d (hereinafter referred to as the tube 5) will be described in detail with reference to FIG. FIG. 3A is an enlarged cross-sectional view of the tube 5, and FIG. 3B is an enlarged cross-sectional view showing the connection state of the second connecting tool 36 and the tube 5. First, the tube 5 will be described with reference to FIG. The tube 5 includes an inner layer 52 that is in contact with ink,
The inner layer 52 has a two-layer structure including an outer layer 53 that covers the outer periphery of the inner layer 52. The inner diameter D1 of the tube 5 is preferably set to about 1.4 mm and the outer diameter is set to about 3.0 mm. However, in the present inkjet recording apparatus 1, the inner diameter is in the range of about 0.8 mm to about 2.0 mm. Outer diameter is approximately 2.4
Each can be configured in the range of mm to approximately 4.0 mmb. The thickness D3 of the outer layer 53 is about 60 μm to about 80 μm
It is preferable in terms of kink resistance that the inner layer 52 has a wall thickness that is about twice or more that of the outer layer 53.

The outer layer 53 is a resin having low vapor permeability and gas permeability, that is, an olefin resin or a fluorine resin, such as tetrafluoroethylene (hereinafter referred to as "FEP"), polytetrafluoroethylene, polyethylene. Polypropylene can be used and is preferably composed of FEP.

The inner layer 52 is made of highly flexible olefin rubber, silicon rubber or fluorine rubber, for example, silicon rubber or fluorine rubber, preferably silicon rubber. The hardness is Shore hardness A.
It is in the range of about 60 to 80 degrees, preferably about 70 degrees.

By thus forming the outer layer 53 of FEP or the like, the evaporation of water in the ink and the invasion of air are suppressed, and the inner layer 52 is made of a flexible material such as silicone rubber.
Flexibility required in the inkjet recording apparatus 1,
Flexibility can be satisfied.

On the other hand, as shown in FIG. 3 (b), the second connector 36 has a maximum diameter d4 which is larger than the inner diameter D1 of the tube 5, and has a tapered head portion 36a whose diameter is reduced toward the distal end thereof. Neck part 3 that is continuous with the maximum diameter part and has a smaller diameter than the maximum diameter part
6b and. Further, the outer diameter d1 of the end portion on the diameter reducing side of the head portion 36a is the inner diameter D1 of the tube 5 (= 1.4 m).
m) is about 1.4 mm, and the maximum diameter d4 is about 2.5 m
The length d2 of the neck portion is approximately 2.5 mm and the outer diameter thereof is approximately 1.6 mm. , Second
The connector 36 can also be constructed in a size proportional thereto. And the tube 5 and the second configured as described above
With the connecting tool 36, the tube 5 is inserted from the head side of the second connecting tool 36 to the neck 36b, and both members are connected.

Therefore, the outer diameter d1 of the end portion of the head portion 36a on the reduced diameter side is configured to be substantially equal to or slightly larger than the inner diameter D1 of the tube 5b.
6 can be easily inserted into the tube 5b and the head 3
Since both members can be connected to each other without forming a gap between the outer peripheral surface on the reduced diameter side of 6a and the inner peripheral surface of the inner layer of the tube 5b, air is stored in the gap and the bubbles grow to cause ink to grow. It is possible to prevent the flow path from being blocked.

The head portion 36a has an inner diameter D of the tube 5.
The inner layer 52 of the tube 5 has a maximum diameter d4 larger than 1 and is reduced in diameter toward the tip, and the inner layer 52 of the tube 5 is made of flexible silicone rubber. Is being expanded,
The largest diameter is the largest. Therefore, the inner peripheral surface of the tube 5 can be closely attached to and connected to the outer peripheral surface of the head portion 36a. Therefore, it is possible to effectively prevent air from entering between the tube 5b and the second connector 36.

Further, the length d2 of the neck portion 36b is about 2.5 m.
m, the difference between the outer diameter d3 of the neck portion 36b and the maximum diameter d4 of the head portion 36a is approximately 0.9 mm.
When a force in the direction of pulling out is applied to the head, the tip of the tube 25 having a reduced diameter has sufficient resistance to expand the diameter toward the head portion 36a, and the tube is loosened from the connector as the carriage reciprocates. , It won't fall out. According to the experiment by the inventor, the length d2 of the neck portion 36b is
It is preferable that the inner diameter D1 of the tube 5 is about 0.7 times or more, and about 1.5 times to about 2 times is optimal from the workability of fitting the tube 5 and the strength of the second connector 36. is there. Further, half the difference between the outer diameter d3 of the neck portion 36b and the maximum diameter d4 of the head portion 36a, that is, the outer circumference of the neck portion 36b and the head portion 3
It is preferable that the step difference from the maximum diameter portion of 6a is approximately 0.3 times or more the inner diameter D1 of the tube 5.

Although the present invention has been described based on the above embodiments, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. This can be easily guessed.

For example, in the above embodiment, the case where the inner layer of the tube 5 is made of a soft material and the outer layer is made of a material having low vapor permeability and gas permeability is explained, but the materials of the inner layer and the outer layer may be reversed. .

[0037]

According to the ink jet recording apparatus of the first aspect, the length of the neck portion of the connecting member is the inner circumference on the end side of the tube which is expanded and fitted to the head portion of the connecting member. The length of the tube (preferably 0.7 times the inner diameter of the tube or more) is reduced in the axial direction from the maximum diameter of the head, so when pulling out the tube. Can give great resistance. As a result, it is possible to reliably connect the tubes in a simple and small structure without loosening air during use and forming air bubbles to form air bubbles, and to perform stable ejection for a long period of time. There is an effect.

According to the ink jet recording apparatus of the third aspect, in addition to the effect of the ink jet recording apparatus of the first or second aspect, the tube has a two-layer structure, and one of the inner layer and the outer layer is a flexible material. Therefore, it is possible to satisfy the flexibility and bending durability required for the tube, and to adhere well to the head of the connecting member. Further, since the other layer is made of a material having low vapor permeability and low gas permeability, it is possible to suppress evaporation of water in the ink and invasion of air into the tube. Therefore, there is an effect that it is possible to prevent thickening of the ink and ejection failure of the ink due to evaporation of water in the ink and invasion of air, and it is possible to maintain good recording quality.

According to the ink jet recording apparatus of the fourth aspect, the one layer of the tube is made of silicone rubber, and the other layer is made of tetrafluoroethylene resin. It is possible to further improve the effect of the described inkjet recording apparatus.

[Brief description of drawings]

FIG. 1 is a plan view showing an internal configuration of an inkjet recording apparatus that is an embodiment of the present invention.

FIG. 2 is a plan view showing an internal configuration of a recording head unit.

FIG. 3A is a sectional view of a tube. (B) is sectional drawing which showed the connection condition of a tube and a 2nd connection tool.

[Explanation of symbols]

1 Inkjet recording device 3 Recording head unit 4 Ink tank (ink supply source) 5a-5d tube (ink flow path) 11 Air trap unit 12 Joint member 36 Second connection tool (connection member) 36a head 36b neck 52 inner layer 53 outer layer

Claims (4)

[Claims] 1. An ink jet recording apparatus having an ink flow path for supplying ink from an ink supply source to a recording head unit for ejecting ink onto a recording medium, wherein a flexible tube forming the ink flow path, The head has a tapered shape having a maximum diameter larger than the inner diameter of the tube and has a diameter reduced toward the tip, and a neck portion continuous to the maximum diameter portion side and having a diameter smaller than the maximum diameter portion, And a connecting member to configure, the tube is expanded and fitted to the head of the connecting member, the inner periphery of the end side of the tube over a predetermined length in the axial direction, the neck. The inkjet recording apparatus is characterized in that the length of the neck portion of the connecting member is configured so as to be smaller than the maximum diameter of the head portion toward the portion side. 2. The ink jet recording apparatus according to claim 1, wherein the length of the neck portion of the connecting member is set to be approximately 0.7 times the inner diameter of the tube or more. 3. The tube has a two-layer structure, one of the inner layer and the outer layer is made of a flexible material, and the other is made of a material having low vapor permeability and gas permeability. The ink jet recording apparatus according to claim 1 or 2, which is characterized. 4. The ink jet recording apparatus according to claim 3, wherein the one layer is made of silicone rubber and the other layer is made of tetrafluoroethylene resin.