JP4605745B2 - Ink heating mechanism of inkjet printer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ink heating mechanism of an ink jet printer for heating functional ink that passes through a nozzle inside an ink jet head of the ink jet printer and reducing the viscosity of the functional ink.
[0002]
[Prior art]
As shown in FIG. 4, nozzles (not shown) arranged on the lower surface of the inkjet head 30 that move relatively above the platen 20 in the XY directions (the horizontal direction and the front and back directions in the drawing) substantially parallel to the surface of the platen 20. Inkjet printers are known in which ink droplets are ejected in the form of dots and landed in the form of dots on the surface of a medium 10 such as a sheet mounted on a platen 20. According to this printer, a picture or / and a character consisting of an array of a plurality of ink dots can be printed on the surface of the medium 10 mounted on the platen 20. In FIG. 4, reference numeral 40 denotes a transport unit that transports the medium 10 on the platen 20 in the X direction. The inkjet head 30 is moved above the platen 20 in the Y direction (front and back direction in the figure) substantially parallel to the surface of the platen 20.
[0003]
In this printer, recently, an ink that uses a functional ink such as a solvent ink in which an ink pigment or an ink dye is dissolved in an organic solvent or a UV ink that cures when irradiated with ultraviolet rays is used as the ink to be supplied to the inkjet head 30. Printers are being developed and used.
Among them, in a printer in which solvent ink is supplied to the ink jet head, solvent ink drops excellent in weather resistance and water resistance are ejected from nozzles arranged on the lower surface of the ink jet head 30, and the ink drops are mounted on the platen 20. The dots are landed on the surface of the medium 10. Then, the ink droplets landed on the surface of the medium 10 are heated by the electric heater 50 provided inside the platen 20 and are fixed on the surface of the medium 10 instantaneously. Then, a picture or / and character composed of an array of a plurality of solvent ink dots, which is not faded and has excellent weather resistance and water resistance, is printed on the surface of the medium 10.
Further, in a printer in which UV ink is supplied to the inkjet head, UV ink droplets are ejected from nozzles arranged on the lower surface of the inkjet head 30, and the UV ink droplets are dot-like on the surface of the medium 10 mounted on the platen 20. To land. Then, the UV ink droplets landed on the surface of the medium 10 are irradiated with ultraviolet rays, and the UV ink droplets are cured on the surface of the medium 10. Then, a picture or / and a character, which is composed of an array of dots of a plurality of UV inks and is excellent in weather resistance and water resistance, is printed on the surface of the medium 10.
Media on which pictures or / and characters are printed using functional inks such as solvent inks and UV inks are used for outdoor advertisements and the like that require weather resistance and water resistance.
[0004]
[Problems to be solved by the invention]
By the way, the functional inks such as the solvent ink and the UV ink as described above have a higher viscosity in a normal temperature state such as around 20 ° C. than the aqueous ink supplied to the ink jet head of a normal ink jet printer. Therefore, when functional inks such as solvent inks and UV inks are supplied to the inkjet head in a room temperature state, the functional ink having a high viscosity can smoothly pass through the fine nozzles inside the inkjet head 30. Instead, there were frequent accidents in which the nozzle stagnated and the nozzle was clogged with functional ink.
[0005]
As a printer capable of solving such problems, conventionally, an ink heating means for heating functional ink such as solvent ink and UV ink supplied to the inkjet head 30 to reduce the viscosity of the functional ink ( An ink jet printer in which an ink jet head 30 is integrally incorporated in the ink jet head 30 has been developed.
In the printer configured as described above, the functional ink such as solvent ink and UV ink supplied to the inkjet head 30 can be heated by the ink heating means to reduce the viscosity of the functional ink. Then, the functional ink having the reduced viscosity can be smoothly passed through the nozzle without resistance without being clogged in the fine nozzle inside the inkjet head 30.
However, in such a printer, the ink jet head 30 in which the ink heating means is integrated is complicated and large-scale, and the weight and size of the ink jet head 30 are larger than those of a normal ink jet head. , Has increased significantly.
On the other hand, the inkjet head 30 has a complicated and precise structure having a large number of fine nozzles arranged on the lower surface thereof, and easily causes an accident such as clogging of the nozzles with ink. Then, the ink jet head 30 in which the nozzle is clogged with ink needs to be replaced with another new one. Therefore, it is desired that the inkjet head 30 that requires such frequent replacement be simplified in size as much as possible to keep the replacement cost low.
In addition, it is desired that the ink jet head 30 keeps its weight as small as possible and keeps the inertial force applied to the ink jet head 30 when the ink jet head 30 is moved as small as possible. Then, it is desired that the inkjet head 30 can be moved relative to the X-Y direction quickly and accurately with small inertial force above the medium 10 mounted on the platen 20.
For this reason, the printer having the ink jet head 30 having a complicated and large structure in which the ink heating means is integrally incorporated as described above is generally difficult to be widely used.
In addition, in the printer in which the ink heating means is integrally incorporated in the inkjet head 30, as described above, since it is desired to reduce the inkjet head 30 as much as possible, it is incorporated in the inkjet head 30. The ink heating means has also become smaller and lighter and has a smaller calorific value. As a result, the number of ink droplets ejected per unit time from the nozzles arranged on the lower surface of the inkjet head 30 increases, and the printing rate of the inkjet head 30 (that is, the ink landed on the surface of the medium 10 per unit time from the inkjet head 30). When the number of droplets) increases, the amount of heat generated by the ink heating means built in the inkjet head 30 tends to be insufficient. Then, the functional ink that passes through the nozzles inside the inkjet head 30 was not heated accurately, and the viscosity of the functional ink increased. An accident in which functional ink is clogged in the nozzle easily occurred.
[0006]
In addition, as a printer that can solve the above-described problems, the functional ink stored in a tank (not shown) before being supplied to the inkjet head 30 is heated to reduce the viscosity of the functional ink in advance. Inkjet printers have also been developed.
According to the printer configured as described above, the functional ink supplied to the inkjet head 30 can be preheated to reduce the viscosity of the functional ink. Then, the functional ink supplied to the inkjet head 30 and having a reduced viscosity can be passed smoothly through the nozzle without clogging in the fine-diameter nozzle inside the inkjet head 30.
However, in the printer having such a structure, the functional ink preheated in the tank or the like is cooled by outside air or the like until it is supplied to the inkjet head 30 through an ink supply tube (not shown) or the like. As a result, the temperature has dropped. Then, the viscosity of the functional ink supplied to the inkjet head 30 is increased, and the functional ink cannot easily pass through the fine nozzle inside the inkjet head 30 and is easily clogged in the nozzle.
[0007]
The present invention has been made in view of such problems, and the first object thereof is to make the nozzle of the fine diameter inside the inkjet head without making the structure of the inkjet head complicated and large. Ink-jet printer ink heating mechanism (hereinafter referred to as ink heating mechanism) that allows functional inks such as solvent inks and UV inks to be smoothly passed without resistance in a state where the viscosity is reliably reduced by constantly heating to a suitable temperature. To provide).
In addition, even if the printing rate of the inkjet head increases, the second purpose is to always heat the functional nozzles such as solvent ink and UV ink to the appropriate temperature by using the fine nozzle inside the inkjet head. It is an object of the present invention to provide an ink heating mechanism that can pass smoothly without resistance in a state where the viscosity is reliably lowered.
Furthermore, the third object is to use a general-purpose inkjet head for an inkjet head that needs to be frequently replaced due to nozzle clogging, and an ink heating mechanism that can keep the replacement cost of the inkjet head low. Is to provide.
[0008]
[Means for Solving the Problems]
In order to achieve such an object, the ink heating mechanism of the present invention includes an ink heating means for heating the ink passing through the nozzle inside the inkjet head of the inkjet printer and reducing the viscosity of the ink. The ink heating means is not covered with the nozzle opening surface, which is the surface in which the nozzle opening is formed in the inkjet head. Along the periphery of the nozzle opening surface, the ink jet head is detachably wound around and attached to the lower periphery of the inkjet head .
[0009]
In the ink heating mechanism having such a configuration, the ink heating means that is detachably wound around the lower portion of the inkjet head is disposed inside the lower portion of the inkjet head via the lower sidewall of the inkjet head. By heating the functional ink that passes through the nozzle, the viscosity of the functional ink can be reduced. Then, the functional ink can smoothly pass through the nozzle having a fine diameter inside the ink jet head without resistance.
[0010]
In addition, when the functional ink is clogged in the fine nozzles arranged on the lower surface of the inkjet head, and it becomes necessary to replace the inkjet head, it is placed around the lower portion of the inkjet head that needs to be replaced. The ink heating means that is detachably wound and attached can be detached from the lower periphery of the inkjet head. Next, when the ink jet head whose nozzle is clogged with ink is replaced with a new ink jet head, the ink heating means detached from the lower periphery of the previous ink jet head is wound around the lower periphery of the new ink jet head. Can be remounted. Then, the ink heating means can be reused as an ink heating means for heating functional ink that passes through a fine nozzle inside the new ink jet head to reduce the viscosity of the functional ink.
In addition, the ink heating means for heating the functional ink that passes through the nozzles inside the inkjet head is not integrated into the inkjet head, but is separated from the inkjet head and attached to the lower periphery of the inkjet head. Therefore, the ink heating means prevents the inkjet head from having a complicated and large structure, and the inkjet head can have a simple and lightweight structure similar to a general-purpose inkjet head. And it becomes possible to reduce the replacement cost of the inkjet head significantly.
Further, since the ink heating means is structured to be wound around and attached to the lower periphery of the inkjet head having a sufficient space, the ink heating means is adjusted to the size of the narrow inner space of the inkjet head. Without being restricted, it can be of a large structure that generates a sufficient amount of heat. And even if the printing rate of the inkjet head increases, the functional ink that passes through the nozzles inside the inkjet head is always accurately heated by using a large-sized ink heating means capable of generating a sufficient amount of heat. Thus, the viscosity of the functional ink can be reliably reduced. And it becomes possible to always pass the functional ink having the reduced viscosity smoothly through the fine nozzle inside the inkjet head without resistance.
In addition, since the ink heating means is structured to be wound around the lower part of the ink jet head near the location of the nozzle built in the ink jet head, the ink heating means is close to the heating means. It is possible to efficiently and accurately heat the functional ink that passes through the nozzles inside the inkjet head disposed in the area.
[0011]
In addition, the ink heating mechanism of the present invention has an ink heating means for heating the ink passing through the nozzles inside the inkjet head and reducing the viscosity of the ink around the lower portion of the inkjet head near the nozzle placement location. The ink heating means has a structure that circulates heated hot water through a passage inside a heating frame that is wound around and attached to the lower periphery of the inkjet head, and is attached to the ink jet head. The means is composed of a U-shaped heating frame that is wound in close contact with the lower periphery of the inkjet head, and a passage for circulating hot water continuously formed inside the frame, and the heating frame The ends of the are connected by bolts, and by tightening the bolts, the inner surface of the heating frame is attached in close contact with the lower periphery of the inkjet head It may be characterized to be.
In such a case, since the specific heat of hot water is higher than that of an electric heater made of metal or the like, a large amount of heat can be accumulated in the hot water circulating in the passage inside the heating frame. Then, from the ink heating means using hot water in which a large amount of heat accumulated in the passage inside the heating frame body is accumulated as a heat source, the lower part of the inkjet head on which the heating frame body is wound is mounted with a sufficient amount of heat. It can be heated stably. And even if the printing rate of the inkjet head increases, the functional ink that passes through the nozzles inside the lower part of the inkjet head is heated accurately by the hot water circulating through the passage inside the heating frame to ensure the viscosity of the functional ink. It is possible to reduce it.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
1 to 3 show a preferred embodiment of the ink heating mechanism of the present invention, FIG. 1 is a structural explanatory view thereof, FIG. 2 is a perspective view thereof, and FIG. 3 is a circuit diagram thereof. The ink heating mechanism will be described below.
[0013]
In the ink heating mechanism shown in FIGS. 1 to 3, the ink heating means 100 for heating the ink passing through the nozzle 32 inside the ink jet head 30 of the ink jet printer and reducing the viscosity of the ink, It has a structure in which it is detachably wound around and attached to the lower periphery of the inkjet head 30 near the place where it is placed.
The ink heating means 100 includes a substantially U-shaped heating frame 102 that is wound in close contact with the lower periphery of the inkjet head 30 and a passage 104 that circulates hot water continuously formed inside the frame. It is configured. Then, hot water is supplied from the hot water circulation means 105 to the passage 104 inside the heating frame, and the hot water is circulated through the passage 104 inside the heating frame, so that the heating frame 102 is heated by the heat of the hot water. It is configured so that the lower periphery of the inkjet head 30 mounted by being wound can be heated. As shown in FIG. 3, the hot water circulation means 105 for circulating the hot water through the passage 104 inside the heating frame body heats the water in the hot water tank 106 by storing the hot water generating water and the hot water tank 106. The hot water generated in the hot water tank 106 and the hot water tank 106 are fed into the passage 104 inside the heating frame through the connecting tube 107, and the hot water is circulated through the passage 104. And a hot water circulation pump 108 for returning to the hot water tank. The heating frame 102 is made of light aluminum having a high thermal conductivity and a specific gravity. The heat accumulated in the hot water circulating through the passage 104 inside the heating frame is passed through the heating frame 102 and the ink jet head 30. It is designed to communicate efficiently around the bottom. In addition, the inner surface of the heating frame 102 is attached to the lower periphery of the inkjet head 30 by tightening the bolts 109 connecting the both ends of the substantially U-shaped heating frame 102. I can do it. Conversely, by loosening the bolts 109 connecting the both ends of the substantially U-shaped heating frame body 102, the heating frame body 102 mounted around the lower portion of the inkjet head 30 is removed from the inkjet head 30. It can be removed from the lower periphery.
[0014]
The ink heating mechanism shown in FIGS. 1 to 3 is configured as described above, and in this ink heating mechanism, a passage inside the heating frame that is wound around the lower portion of the inkjet head 30 and attached. The hot water can be circulated using the hot water circulating means 105. And the surroundings of the lower part of the inkjet head 30 with which the heating frame 102 was wound and mounted | worn with the warm water can be heated. The functional ink such as solvent ink and UV ink that passes through the nozzle 32 inside the lower part of the inkjet head 30 can be heated to reduce the viscosity of the functional ink. And the functional ink which reduced the viscosity can be smoothly passed through the nozzle 32 of the fine diameter inside an inkjet head without resistance.
[0015]
Further, when the functional ink is clogged in the nozzle 32 having a small diameter inside the ink jet head 30 and the ink jet head 30 needs to be replaced, the ink jet head 30 that needs to be replaced is replaced. The bolt 109 connecting the both ends of the heating frame body 102 of the ink heating means which is detachably wound around the lower part is loosened, and the heating frame body 102 of the ink heating means is attached to the ink jet head 30. It can be detached from the lower periphery. Next, when the ink jet head 30 in which the nozzle 32 is clogged with ink is replaced with a new ink jet head, the heating frame body 102 of the ink heating means detached from the lower periphery of the previous ink jet head is replaced with the new ink jet head. The heating frame 102 is wound around the lower part of the head 30 and fastened with bolts 109 connecting both ends of the heating frame body 102, so that the heating frame body 102 is closely attached to the lower part of the inkjet head 30 and remounted. it can. Then, the ink heating means 100 having the heating frame 102 as a main component heats the functional ink that passes through the nozzle 32 having a small diameter inside the new inkjet head 30 to reduce the viscosity of the functional ink. The ink heating means 100 can be reused.
[0016]
Further, since the ink heating means 100 is separated from the inkjet head 30 and is attached to the lower periphery of the inkjet head 30, the ink heating means 100 makes the inkjet head 30 a complicated and large structure. Therefore, a small-sized general-purpose inkjet head having a simple structure can be used as the inkjet head 30.
[0017]
Furthermore, the ink heating means 100 wound around and mounted around the lower portion of the inkjet head 30 having a sufficient space can be of a large structure capable of generating a sufficient amount of heat. Even when the printing rate of the inkjet head 30 is increased, the functional ink that passes through the nozzles 32 inside the inkjet head is always accurately used by using the ink heating means 100 having a large structure capable of generating a sufficient amount of heat. The viscosity of the functional ink can be reliably reduced.
[0018]
In addition, using the ink heating means 100 structured to be wound around and attached to the lower periphery of the inkjet head 30, the function of passing the nozzle 32 inside the lower portion of the inkjet head 30 disposed near the heating means 100. Ink can be heated efficiently and accurately.
[0019]
The temperature of the hot water that passes through the passage 104 inside the heating frame of the heating means that is wound around the lower portion of the inkjet head shown in FIGS. 1 to 3 is preferably 40 to 50 ° C. Then, the functional ink that passes through the nozzle 32 inside the lower part of the inkjet 30 is heated to around 45 ° C., and the viscosity of the functional ink is reduced to about 5 cps. It has been confirmed through experiments that the nozzle 32 can be smoothly passed through without resistance.
[0020]
In the ink heating mechanism of the present invention, the ink heating means 100 wound around the lower portion of the inkjet head 30 can be a large electric heater or the like having a large calorific value.
[0021]
【The invention's effect】
As described above, according to the ink heating mechanism of the present invention, when an ink jet head causes ink clogging in a nozzle and the ink jet head is replaced with a new ink jet head, the ink attached to the previous ink jet head is used. The heating means can be detached from the inkjet head and reattached to a new inkjet head. Then, the ink heating means can be reused for a new ink jet head.
In addition, a small-sized general-purpose inkjet head having a simple structure can be used for an inkjet head that needs to be frequently replaced due to ink clogging. And it becomes possible to suppress the replacement cost of the inkjet head.
Furthermore, the heating means wound around and attached to the lower periphery of the inkjet head can be of a large structure with a large calorific value. And even if the printing rate of the ink jet head is increased by using the heating means of the large structure, the functional ink that passes through the nozzle disposed inside the lower part of the ink jet head is heated accurately with a sufficient amount of heat, It becomes possible to reliably reduce the viscosity of the functional ink.
[Brief description of the drawings]
FIG. 1 is a schematic structural explanatory diagram of an ink heating mechanism of the present invention.
FIG. 2 is a perspective view of an ink heating mechanism of the present invention.
FIG. 3 is a circuit diagram of the ink heating mechanism of the present invention.
FIG. 4 is a side sectional view showing a schematic structure of an ink jet printer using solvent ink.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Media 20 Platen 30 Inkjet head 32 Nozzle 100 Ink heating means 102 Heating frame body 104 Passage 105 inside heating frame body Hot water circulation means 109 Bolt

Claims (1)

A plurality of ink dots are formed by ink droplets that are ejected from nozzles arranged on the lower surface of an ink jet head that moves relative to the medium above the medium mounted on the platen and land on the surface of the medium mounted on the platen. In an inkjet printer that prints a picture or / and a character consisting of an array,
Ink heating means for heating the ink passing through the nozzles inside the inkjet head and reducing the viscosity of the ink is detachably wound around the lower part of the inkjet head near the nozzle location. And
The ink heating means is configured to circulate heated hot water through a passage inside a heating frame that is wound around and attached to the lower periphery of the inkjet head,
The ink heating means includes
A U-shaped heating frame that is wound in close contact with the lower periphery of the inkjet head; and
A path for circulating hot water continuously formed inside the frame body,
Ink for an ink jet printer, wherein both ends of the heating frame body are connected by bolts, and the inner surface of the heating frame body is attached in close contact with the lower periphery of the ink jet head by tightening the bolts. Heating mechanism.

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