JPH06278289A - Ink jet recording apparatus - Google Patents

Abstract

PURPOSE:To prevent the detachment of a joint from a main body by providing the hook engaging the end part of the joint connecting tubes forming ink passages and the main body to the main body. CONSTITUTION:A tube 22 is inserted in a joint from the end part thereof so as to forcibly expanding the end part of the joint and the flange part of the tube 22 is fitted in the region different in inner diameter of the joint. Herein, the outer diameter phid2, of the tube 22, the outer diameter phid1, of the flange part 22a and the inner diameters phiD1, phiD2, of the joint are set to the relation of phiD1>=phid1>phid2>phiD2. Therefore, as cleared from an inequality of phid2>phiD2, since the inner diameter of the joint is set so as to be smaller than the outer diameter of the tube, the sealability of the tube 22 and the joint (a) is generated by the clamping flange of the joint. The slipping-off of the tube 22 is prevented because the flange part 22a is larger than the end part of the joint to act as a stopper in the slipping-off direction of the tube.

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 having a structure in which a tube forming an ink flow path is connected to a main body such as a sub tank using a joint member.

[0002]

2. Description of the Related Art In recent years, there has been a demand for improvement in recording quality even in ink jet printers, and the density of recording dots has been increasing. Along with this, due to the increased capacity of the flat cable and the flexible cable connecting the recording head and the circuit board, the number and thickness of the cables are increased. In particular, in an inkjet printer, an ink supply tube for supplying ink to a recording head from an ink supply unit such as an ink tank in which ink is stored in addition to a cable, and a rise in ink level of a sub tank on a carriage and ink Sub-tank tubes are provided to keep the liquid level constant.Each tube is inserted into a rubber joint, and the other end of the joint into which the tube is inserted is attached to the sub-tank. It is designed to be inserted into a joint.

Further, in an ink jet recording apparatus, paper dust, dust, or the like adheres to the ink ejection surface provided on the front surface of the recording head, or the water content of the ink evaporates to increase the viscosity, so that the ink is ejected from the nozzles. The outlet is clogged, causing defective ink ejection. Therefore, in order to prevent clogging, when not in use, an elastic cap member made of rubber or the like is attached to the ink ejection surface for sealing, and suction means (negative pressure generation source) is used to interpose the cap member and the tube. A suction recovery device has been developed in which ink is sucked from a discharge port to normalize the discharge.
This suction recovery device is configured by inserting a tube into the elastic cap member, and is connected to the negative pressure generation source by inserting the tube into a rubber joint.

Further, due to the colorization of ink jet printers and the improvement of recording quality, the number of tubes such as ink supply tubes, sub-tank tubes, suction tubes, etc. tends to increase, and therefore the number of joints for connecting the tubes also increases. is doing.

FIG. 7 is a sectional view of a joint structure of a conventional ink jet printer. In the figure, reference numeral 17 indicates a flexible tube, and 18 indicates a main body, for example, a sub tank. Reference numeral 19 denotes a joint, which is made of an elastic material such as silicone rubber or butyl rubber,
The inner diameter of the joint 19 is set smaller than the outer diameter of the tube 17 and the outer diameter of the projecting joint 18a protruding from the main body 18. The tube 17 and the sub-tank 18 are connected by fitting one end of the joint 19 to the projecting joint 18 a and fitting the other end of the joint 19 to the tube 17.

[0006]

However, in the conventional example, the joint force between the tube and the joint and the joint force between the joint and the main body are the contracting force of the joint and the joint force generated by the interference of the joint. Since it depends only on the frictional force generated between the inner wall and the outer wall of the tube and the joint of the main body, external force generated by vibration or drop is applied to the product, force is applied to the tube due to the movement of the carriage, or the joint is caused by the temperature difference. There is a problem that the tube may come out of the joint or the joint may come out of the main body when the length of the body becomes longer.

There is also a problem that an operator inadvertently catches and pulls out the tube during assembly in a factory. Further, the amount of insertion of the tube into the joint and the amount of insertion of the joint into the main body are determined by the feeling of the operator. Specifically, until the tube hits the protruding joint or the joint hits the main body. If you insert the marking line on the tube until it reaches the end of the joint, you will have an ambiguous control. There was also the problem of the tube coming off.

Further, for some reason, for example, when a service person pulls out the tube from the joint in the market, even if the tube is once again inserted into the joint to which ink is attached, the ink flows around between the tube and the joint. There was also a problem that the frictional force was reduced and the initial binding force could not be obtained.

[0009]

According to the present invention, the main body is provided with a hook for locking the end portion of the joint for connecting the tube forming the ink flow path and the main body to prevent the joint from coming off the main body. This is to prevent it.

Further, according to the present invention, the joint connecting the tube forming the ink flow path and the main body is provided with a portion having a different inner diameter, and the other tube is provided with a portion having a different outer diameter so that the outer diameter of the tube is different. The tube is prevented from falling out of the joint by setting the portion at a portion having a different inner diameter of the joint.

[0011]

EXAMPLES The present invention will be specifically described based on the following examples. FIG. 1 is a schematic perspective view showing the entire inkjet recording apparatus of the present invention. In the figure, reference numeral 1 indicates a recording head, and the recording head 1 is mounted on a carriage 2. The carriage 2 includes a platen 5 that supports the recording medium 4.
It is slidably attached to a carriage shaft 3 arranged parallel to the recording head 1. The recording head 1 faces the recording medium 4 by driving a carriage motor (not shown) through a timing belt (not shown). In this state, the carriage shaft 3 is reciprocated. The recording head 1 is provided with nozzles (not shown) that eject ink droplets toward the recording medium 4 for printing the recording medium 4. Ink is supplied to this nozzle from an ink supply unit 7 (ink cartridge) via an ink remaining amount detector (not shown), an ink supply tube 8 and a sub tank 6 provided on the carriage 2.

The ink remaining amount detector and the ink supply tube 8 are connected by a joint a made of rubber, and the ink supply tube 8 and the sub tank 6 are connected by a rubber joint (not shown). The details of the connection between the tube and the joint in these connections and the details of the connection between the joint and the main body will be described later.

Further, one end of a sub-tank tube 9 is connected to the sub-tank 6 by a rubber joint (not shown) in order to raise the ink level of the sub-tank and keep the ink level constant. The other end is connected to a pump portion (not shown) of the ink suction recovery system by a rubber joint d.

The suction of ink from the nozzle for normalizing the nozzle in which the ejection failure has occurred is performed by operating the pump via the suction tube 10 after sealing the head with the elastic cap. Here, one end of the suction tube 10 is inserted into the elastic cap, and the other end is connected to the pump by a joint (not shown).

2 to 6 show the structures of various tubes, joints and main bodies (for example, sub-tanks) described above and the connection (coupling) between the tube and the joint or the connection (coupling) between the joint and the main body. Will be described below.

(Embodiment 1) First, referring to FIGS. 2 and 3, FIGS. 2 and 3 show Embodiment 1 of the present invention. FIG. 2 shows a joint, a tube and a hook of an ink jet recording apparatus. And FIG. 3 is a cross-sectional view and an end view showing the arrangement relationship of FIG. The joint (for example, a) is made of an elastic material such as butyl rubber or silicone rubber. As shown in FIG. 3, the cross section of the joint has portions having different inner diameters, that is, a part of the joint has a large inner diameter (inner diameter φ
D ₁ ), and the structure returns to the original inner diameter (φD ₂ ) at the end (φD ₁ > φD ₂ ).

On the other hand, as shown in FIG.
Is the flange 2 on a part of the tube 22 (outer diameter φd ₂ ).
2a (outer diameter φd ₁ ) is integrally provided.
As shown in FIG. 2, the tube 22 is inserted from the end of the joint so as to push the end wide.
The two flange portions are fitted into the joints having different inner diameters.

[0018] Here, the inner diameter of the outer diameter .phi.d ₁ and the joint portion of the outer diameter .phi.d ₂ and the flange portion 22a of the tube 22 phi
The relationship between D ₁ and φD ₂ is φD ₁ ≧ φd ₁ > φd ₂ > φ
It is set to be D ₂ . Therefore, tube 2
As is clear from the inequality of φd ₂ > φD ₂ , the sealability between 2 and the joint a is caused by the interference of the joint because the inner diameter of the joint is set smaller than the outer diameter of the tube.

The tube 22 from the joint a
The flange 22a (φd
₁ ) is larger than the end of the joint (φD ₂ ), so that it acts as a stopper in the pull-out direction, so that it is achieved.
Further, the management of the insertion amount of the tube with respect to the joint is surely performed by the flange portion 22a of the tube 22 entering the step portion a1 (φD ₁ ) of the joint a, and the predetermined insertion amount is secured, Stabilization of the connecting force between the tube and the joint is achieved. In addition, the efficiency of the assembly worker can be improved. In addition, even if ink is attached to the inner wall of the joint or the outer diameter of the tube when the tube is removed from the joint due to maintenance by a service person, etc. The tube will not come out again because it is set in the section.

Next, with reference to FIG. 2, the prevention of the joint from coming off from the main body will be described. As shown in FIG.
A hook 13 having an L-shaped cross section is provided from 8 to the end surface of the joint a so as to serve as a stopper in the direction of removal of the joint. The hook 13 may be molded integrally with the main body, or may be made as a separate part and fixed to the main body. The hook 13 is deformable in the directions of arrows A and B,
At the time of attaching the joint, the joint 22 is bent in the direction of arrow B so that the joint 22 can be inserted into the joint 18a of the main body 18. After the joint is attached, the hook 13 returns to its original position by the elastic force so as to hold down the end surface of the joint a. Become. Therefore, even if the joint tries to come out from the joint of the main body, the end face of the joint hits the hook 13, and therefore the joint does not come off.

(Embodiment 2) FIG. 4 shows Embodiment 2 of the present invention, and is a sectional view and an end view showing the positional relationship of the joint, tube and hook of the ink jet recording apparatus. In this embodiment, as shown in FIG.
A groove 13b (U-shaped) is provided on a tip 13a of a hook 13 having an L-shaped cross section provided on the end surface of the joint a. By inserting the tube 22 into the groove 13b of the hook from above, not only the direction in which the joint comes out (arrow C) but also the direction in which the joint a and the tube 22 are left and right (arrow D)
The movement of can also be regulated.

Therefore, the problems of the tube coming off and the joint coming off can be greatly improved.
Further, by providing a protrusion in the groove, vertical movement after the tube is put in the groove may be restricted.

(Embodiment 3) FIG. 5 shows Embodiment 3 of the present invention, and is a sectional view and an end view showing the positional relationship of the joint, tube and hook of the ink jet recording apparatus. In this embodiment, the joint 14 is not provided with parts having different inner diameters. As shown in FIG. 5, the joint 14 has the same inner diameter, and the tube 15 is provided with a flange portion 15 a. One surface of the flange portion 15a is in contact with the joint 14, and the other surface is provided so as to project from the main body and is in contact with the hook 13 having an L-shaped cross section.
Therefore, the flange portion 15a of the tube 15 is sandwiched between the joint 14 and the hook 13, and the tube and the joint are prevented from coming off. In addition, since the joint does not require extra processing, cost reduction can be achieved.

(Embodiment 4) FIG. 6 shows Embodiment 4 of the present invention and is a cross-sectional view showing a positional relationship among joints, tubes and hooks of an ink jet recording apparatus. In this embodiment, as shown in FIG.
This is an example in which the O-ring 20 is attached to the tube instead of the flange portion without integrally providing the flange portion. O
By using the ring 14, the tube has a simple shape, and the cost can be reduced. Also, the O-ring 14 is
By using a material with a high friction coefficient for the tube, such as butyl rubber, and setting the inner diameter of the O-ring to be smaller than the outer diameter of the tube, the friction coefficient of the O-ring and the tube is significantly increased, and the flange is integrated with the tube. The same level of pullout prevention strength as when the portion is provided can be obtained. That is, by sufficiently tightening the O-ring and the tube, the tube and the O-ring behave in the same way as the one in which the O-ring hits the inner wall of the joint when the force of pulling out the tube acts, and the tube It is prevented from coming off. Although the O-ring is used in this embodiment, the cross-sectional shape of the ring is not limited to a circle, but may be a quadrangle or a rectangle.

[0025]

As described above, according to the present invention,
By providing a hook from the main body to the end of the joint with respect to the joint connecting the tube forming the ink flow path and the main body, it is possible to prevent the joint from coming off the main body. Further, it is possible to prevent the tube from coming off the joint.

Further, the joint for connecting the main body and the tube is provided with a portion having a different inner diameter, the tube is further provided with a protrusion, and the protrusion of the tube is set at a portion having a different inner diameter of the joint so that the tube is prevented from coming out of the joint. It can be prevented.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an inkjet recording apparatus of the present invention.

FIG. 2 is a sectional view showing a positional relationship between a joint, a tube and a hook of the inkjet recording apparatus of the present invention.

FIG. 3 is a detailed cross-sectional view of a joint and a tube.

FIG. 4 is a cross-sectional view showing a second embodiment of the inkjet recording apparatus of the present invention.

FIG. 5 is a cross-sectional view showing a third embodiment of the inkjet recording apparatus of the present invention.

FIG. 6 is a cross-sectional view showing a fourth embodiment of the inkjet recording apparatus of the present invention.

FIG. 7 is a cross-sectional view showing a joint state of a joint and a tube of a conventional inkjet recording apparatus.

[Explanation of symbols]

 1 Recording Head 2 Carriage 3 Carriage Shaft 4 Recording Medium 5 Platen 6 Sub Tank 7 Ink Supply Section 8 Ink Supply Tube 9 Sub Tank Tube 10 Suction Tube 13 Hook a Joint 18 Main Body

Claims (8)

[Claims] 1. An ink jet recording apparatus, wherein a hook is provided from a main body so as to press an end portion of the joint with respect to a joint connecting a tube forming an ink flow path and the main body. 2. A joint for connecting a tube forming an ink flow path and a main body is provided with a portion having a different inner diameter, a tube is provided with a portion having a different outer diameter, and a portion having a different outer diameter of the tube and an inner diameter of the joint are provided. An ink jet recording apparatus characterized in that different parts of the above are fitted to each other and a tube is connected to a joint. 3. An ink jet recording comprising a joint which can be fitted to a protruding portion of a main body and has a step portion in an inner diameter, and a tube having a flange portion which can be fitted to the step portion of the joint. apparatus. 4. The inkjet recording apparatus according to claim 3, further comprising a hook protruding from the main body so as to press the end portion of the joint. 5. The ink jet recording apparatus according to claim 4, wherein a groove for receiving a tube is formed at a tip of the hook. 6. A joint that can be fitted to a protruding portion of a main body, a tube that can be fitted to the joint and has a flange portion, and a flange portion of the tube is sandwiched between an end portion of the joint. An ink jet recording apparatus having a hook protruding from the main body. 7. An ink jet system, comprising: a joint that can be fitted to a protruding portion of a main body and has a step portion in an inner diameter; and a tube to which a ring that can be fitted to the step portion of the joint is attached. Recording device. 8. The inkjet recording apparatus according to claim 7, further comprising a hook protruding from the main body so as to press the end portion of the joint.