JP3168742B2 - Mold for forming channel substrate of inkjet head, and method of manufacturing mold for channel substrate of inkjet head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-demand type ink jet head which, when print data is received, causes ink droplets to fly and form dots on recording paper using the ink droplets.

[0002]

2. Description of the Related Art To realize high print quality required for an on-demand type ink jet head, it is necessary to further increase the nozzle density.
As disclosed in Japanese Patent No. 64450, a highly integrated ink jet head is provided in which ink chambers communicating with respective nozzles are alternately opposed from both sides to nozzle rows formed on a common flow path substrate. In addition, in order to form this kind of flow path substrate at low cost, a manufacturing method of integrally forming the same by injection molding using a polymer resin material has been adopted. ing.

[0003]

However, in such a conventional ink jet head, the polymer resin material of the flow path substrate is apt to adsorb air bubbles, and the width and depth of the supply path are reduced, so that the air bubbles can be discharged easily. Was particularly poor, and the printing characteristics lacked stability.

[0004] End milling, which is a conventional mold processing method, has a problem in tool durability. Particularly, in the processing of a flow path substrate for a highly integrated ink jet head, the tool is very small and abrasion is severe, it is difficult to control the dimensions of the cutting groove, and it has been difficult to stably supply a high-precision mold.

In addition, the surface condition of the flow path substrate is poor at the contact surface between the dies, causing burrs, cracks, chipping, etc., which hinders the close contact between the flow path substrates and the sealing member, and reduces the ink sealing property. It was difficult to secure. For this reason, there has been a problem that ink adheres to peripheral devices, causing stains and corrosion.

[0006] As described above, the conventional highly integrated flow path substrate has poor air bubble discharge properties, and it is difficult to seal ink. In addition, a mold for injection molding the flow path substrate also has a problem that it is difficult to secure dimensional accuracy and difficult to manufacture stably.

[0007]

In order to solve the above problems, a molding die for a flow path substrate of an ink jet head according to the present invention comprises: an ink chamber communicating with each of a plurality of nozzles;
In a molding die for a flow path substrate of an ink jet head, a molding die for forming a supply path connected to the ink chamber and a common ink reservoir connected to the supply path by injection molding is formed. The mold has a supply path forming groove extending from one end to the other end, and an ink chamber wall forming groove extending from one end to the other end in a direction crossing the supply path forming groove deeper than the supply path forming groove. It is characterized by having at least a channel forming die piece for forming a chamber and a supply path. Further, in the molding die for the flow path substrate of the inkjet head, the molding die further has a peripheral molding die piece for forming a common ink reservoir, and the peripheral molding die piece and the flow path molding die are formed. The two pieces are brought into contact with no gap, and the contact surfaces are arranged on the convex portions of the flow path forming die piece and the peripheral forming die piece. Further, the method of manufacturing a mold for forming a flow path substrate of an ink jet head according to the present invention includes an ink chamber communicating with each of the plurality of nozzles, a supply path communicating with the ink chamber, and a common ink reservoir connected to the supply path. In a method of manufacturing a flow path substrate forming die of an ink jet head in which a forming die to be formed by injection molding includes a plurality of frames, the forming die is a flow path forming die for forming an ink chamber and a supply path. A supply path forming groove which is cut straight by moving a supply path forming blade straight with respect to the flow path forming die piece and passes from one end to the other end of the flow path forming die piece. The first step of forming, the ink chamber wall forming blade is moved straight in a direction intersecting with the supply path forming groove, and the flow path forming die piece is cut linearly deeper than the supply path forming groove,
Forming an ink chamber wall forming groove extending from one end to the other end of the channel forming die piece. Further, in the method of manufacturing a mold for forming a flow path substrate of an ink jet head, the method further includes a peripheral molding die piece for molding a common ink reservoir, and cutting the peripheral molding die piece to form a common ink reservoir wall forming groove. A first step of processing, a second step of polishing the side surfaces of the flow path molding die piece and the peripheral molding die piece and bringing them into contact without any gap, and a flow path molding die piece and the peripheral molding die piece And a third step of relatively fixing the position.

(2) a plurality of nozzles, an ink chamber communicating with the nozzle, a supply path communicating with the ink chamber,
A molding die for a flow path substrate of an ink jet head having a common ink reservoir connected to the supply path and manufacturing at least the ink chamber and the supply path by injection molding, wherein the molding die is a flow path molding die; A supply path forming groove in which the flow path forming die piece passes from one end to the other end, and the flow path forming die intersects the supply path forming groove deeper than the supply path forming groove. It is characterized by having an ink chamber wall forming groove that passes from one end of the frame to the other end.

(3) a plurality of nozzles, an ink chamber communicating with the nozzle, and a supply path communicating with the ink chamber;
A molding die for a flow path substrate of an ink jet head having a common ink reservoir connected to the supply path and manufacturing at least the ink chamber, the supply path, and the common ink reservoir by injection molding, wherein the molding die is Item 3. The flow path forming die top and the peripheral forming die top for forming the common ink reservoir, which are in contact with each other without any gap, and the contact surfaces thereof are the flow path forming die top and the peripheral forming die. It is characterized in that it is arranged on the convex part of the frame.

(4) a plurality of nozzles, an ink chamber communicating with the nozzle, a supply path communicating with the ink chamber,
In the method of manufacturing a mold for forming a flow path substrate of an ink jet head having a common ink reservoir connected to the supply path and manufacturing at least the ink chamber and the supply path by injection molding, the supply path forming blade is moved straight. A first step of cutting a flow path forming die piece constituting a part of the forming die to form a supply path forming groove extending from one end to the other end of the flow path forming die piece; The wall forming blade is moved straight in a direction intersecting with the supply path forming groove, the flow path forming die piece is cut deeper than the supply path forming groove, and the flow path forming die piece is removed from one end to the other end of the flow path forming die piece. And a second step of forming the ink chamber wall forming groove.

(5) The method for manufacturing a channel forming die piece according to the above (4), wherein a first step of cutting a peripheral forming die piece to form a common ink reservoir wall forming groove is performed, A second step of polishing the side surfaces of the flow path molding die piece and the peripheral molding die piece to make them contact without any gap, and relatively positioning the flow path molding die piece and the peripheral molding die piece And a third step of fixing.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the drawings.

FIG. 1 shows an ink jet head according to an embodiment of the present invention. FIG. 2 shows an example of a molding die 340 for injection-molding the flow path substrate 230 of the ink jet head. It is shown.

As shown in FIG. 1, the nozzle 190 is opened in the nozzle plate 33 and connected to the ink chamber 170. The ink chamber 170 is connected to the common ink reservoir 53 via the supply path 35. The pressure generating member 150 presses the sealing member 30 by applying a voltage, and discharges the ink in the ink chamber 170 sealed by the sealing member 30 from the nozzle 190. The ink chamber 170, the supply path 35,
A common ink reservoir 53 is provided.

As shown in FIG. 3, a molding die 340 for injection-molding the flow path substrate 230 has a flow path molding die top 34.
1 and a peripheral molding die top 342, both of which are in contact with no gap, and the contact surface 280 of which is in contact with the flow path forming die top 34.
It is arranged between the first protrusion 57 and the protrusion 58 of the peripheral molding die top 342.

As shown in FIG. 4, the flow path forming die piece 341 has a supply path forming groove 343 extending from one end 260 to the other end 261 and a depth deeper than the supply path forming groove 343, and intersects with the groove. An ink chamber wall forming groove 344 extends from one end 263 to the other end 262 of the path forming die top 341.
As shown in FIG. 5, the flow path forming die piece 341 is moved straight in the direction of the arrow by an automatic processing machine or the like programmed in advance to form the flow path forming die piece 34.
1 is cut from one end 260 to the other end 261 to cut the supply path forming groove 343, and then, as shown in FIG. 6, the ink chamber wall forming blade 346 is cut by a similar automatic processing machine or the like. Go straight from the location of A to the location of B,
The flow path forming die piece 341 is moved from one end 263 to the other end 26 thereof.
2 and cut deeper than the supply path forming groove 343 to process the ink chamber wall forming groove 344. Next, the ink chamber wall forming blade 346 is returned straight to the opposite position from b to a and returns to the original position. Is manufactured by the manufacturing method of the step of forming a plurality of Flow path molding die top 34
1 so that the ink chamber wall forming blades 3 are formed so as to leave the convex portions 57 at both ends.
It is desirable that the cutting be advanced slightly from inside.

As described above, the flow path molding die piece 34
In the first manufacturing method, the supply path forming blade 345 and the ink chamber wall forming blade 346 move linearly from one end to the other end of the flow path forming die piece 341 to advance the processing.
The width W of the ink chamber wall forming blade 346 does not need to be reduced in diameter as in the end mill end, but may be reduced in the cutting width direction (y direction). As a result, a sufficient length L can be provided in the cutting direction (x direction), and the durability of the supply path forming blade 345 and the ink chamber wall forming blade 346 can be greatly improved. Is less likely to be worn, and the flow path molding die top 341 can always be supplied with high accuracy.

Furthermore, machining can be completed without moving the tool in the cutting depth direction (z direction). Therefore, a repetitive operation error in the z direction of an automatic processing machine or the like does not occur, the accuracy of the supply path forming groove 343 and the depth of the ink chamber wall forming groove 344 is improved, and a forming die for a high-density inkjet head can be processed for the first time. It became. In particular, the depth of the supply path forming groove 343 is transferred to the supply path 35 during injection molding,
It is an important parameter that determines the characteristics such as the discharge speed and the discharge amount, and such a supply path forming groove 343 can be realized for the first time by the processing method.

The supply path forming blade 345 and the ink chamber wall forming blade 346 can have various shapes. As an example, a stepped ink chamber wall forming blade 346 as shown in FIG. 7 forms a corner at the bottom of the ink chamber 170 to prevent the accumulation of bubbles.

As shown in FIG. 8, the other peripheral molding die piece 342 is cut by the end mill 71 to form a common ink reservoir wall forming groove 347 and a nozzle plate positioning hole forming projection. 348, manufactured in the process of processing the positioning pin holes 349. End mill 7
1 advances processing while selecting a diameter suitable for each processing. The inside is slightly cut so as to leave the convex portion 58 near the contact surface with the channel forming die piece 341.

As shown in FIG. 9, the molding die 340 polishes the side surface 270 of the flow path molding die piece 341 and the side surface 271 of the peripheral molding die piece 342 manufactured as described above by lapping or the like. Contacting the two without gaps,
By adjusting the positions of the flow path forming die top 341 and the peripheral forming die top 342, the height deviation h between the bottom of the ink chamber wall forming groove 344 and the bottom of the peripheral forming die top 342 is reduced to zero, and both are screwed. It is manufactured by a process of fixing with, for example.

When a high-temperature polymer resin is poured into the molding die 340 thus manufactured and filled by pressing, the irregularities of the molding die 340 are transferred to the flow path substrate 230 as they are, and the ink chamber wall forming groove 344 is formed. The ink chamber wall 180, the supply path forming groove 343 and the supply path 35, and the nozzle plate positioning hole forming projection 348 corresponds to the nozzle plate positioning hole 35.
0, the drive unit positioning pin 351 is
52 are transferred to the channel substrate 230, respectively. In this way, the ink chamber 170 separated by the ink chamber wall 180, the supply path 35 communicating with the ink chamber 170, and the common ink reservoir 53 communicating with the supply path 35 are formed on the flow path substrate 230.

One of the features of the present invention lies in the shape of the supply passage 35 thus configured. The shape of the supply passage 35 is equal to the width of the ink chamber 170 and the depth of the supply passage 35 is, as shown in FIG. It is shallower than room 170. Such a supply path 35 promotes the flow of bubbles, and promotes the removal of bubbles in the flow path (refers to the common ink reservoir 53, the supply path 35, and the ink chamber 170). Therefore, the effect of stabilizing the ink ejection characteristics is produced. This effect will be described in more detail with reference to FIG.
Numeral 10 is sucked into the supply path 35 by suction of ink, and reaches the entrance of the supply path 53. Since the supply path 53 is narrowed in the depth direction, the bubble 210 is crushed from below, deforms along the sealing member 30 on the upper surface of the ink chamber 170, and gradually advances toward the outlet direction of the supply path 53. Go out. (Air bubbles 211 in the figure) When the ink reaches the outlet of the supply path 53, the ink chamber 17
The bubbles spread to zero (bubbles 212 in the figure). In this series of flows, the bubbles always move linearly along the surface of the sealing member 30, so that the force that hinders the flow of the bubbles is weak, and the bubble is easily discharged.

The present invention is also characterized by the shape of the molding die near the contact surface between the flow path molding die piece 341 and the peripheral part molding die piece 342, and the shape is, as shown in FIG. The periphery of the surface 280 is surrounded by the convex portions 57 and 58. This convex shape hides, in the groove 353, defects such as burrs, cracks, and chips generated on the surface of the flow path substrate 230 near the contact surface 280 of the molding die 340 (see FIG. 2).
As shown in FIG. 12, the flow path substrate 230 and the sealing member 30
Adhere to both sides of the groove 353, and the ink sealing property of the ink chamber 170 is ensured. On the other hand, the contact surface 28 of the molding die 340
Burrs and cracks generated on the surface of the flow path substrate 230 near 0
The surface roughness such as chipping is hidden by the bottom portion 285 of the groove 353 and does not contact the sealing member 30, so that a defect generated during the manufacturing does not affect the ink sealing property. The depth of the groove 353 is desirably such that the surface roughness is sufficiently buried.

The present invention relates to a nozzle 19 as shown in FIG.
0 is integrally formed with the flow path substrate 230.
Can also be applied.

[0026]

According to the present invention, a mold for forming a flow path substrate of an ink jet head includes an ink chamber communicating with each of a plurality of nozzles, a supply path communicating with the ink chamber, and a common ink reservoir connected to the supply path. In a molding die for a flow path substrate of an ink jet head in which a molding die for forming by injection molding is composed of a plurality of frames, the molding die has a supply path forming groove extending from one end to the other end, and a supply path. By providing an ink chamber wall forming groove that extends from one end to the other in a direction that intersects the supply path forming groove deeper than the forming groove, at least a flow path forming die piece that forms the ink chamber and the supply path is provided. With this, in a molding die for molding a flow path substrate of an ink jet head requiring fine processing, a die for molding a supply path and an ink chamber which requires the most complicated and accurate is called a flow path molding die piece. Since the supply path forming groove and the ink chamber wall forming groove formed in the flow path forming die piece can be linearly processed, a flow path substrate having a shape excellent in bubble discharging property can be accurately formed. It is possible to provide a molding die for performing the above. Further, the method of manufacturing a mold for forming a flow path substrate of an inkjet head according to the present invention includes an ink chamber communicating with each of the plurality of nozzles, a supply path communicating with the ink chamber, and a common ink reservoir connected to the supply path. In a method of manufacturing a flow path substrate forming die of an ink jet head in which a forming die for injection molding is formed by a plurality of frames, the forming die is a flow path forming die for forming an ink chamber and a supply path. It has at least a top,
A first step of forming a supply path forming groove extending from one end of the flow path forming die piece to the other end by linearly cutting the supply path forming blade by moving the supply path forming blade straight to the flow path forming die piece; Move the ink chamber wall forming blade straight in the direction crossing the supply path forming groove,
A second step of linearly cutting the flow path forming die piece deeper than the supply path forming groove to form an ink chamber wall forming groove extending from one end to the other end of the flow path forming die piece. The mold for forming the supply path and the ink chamber may be a flow path forming die piece, and the supply path forming groove and the ink chamber wall forming groove formed in the flow path forming die piece may be linearly processed. Therefore, a sufficient width can be provided in the cutting direction of the supply path forming blade and the ink chamber wall forming blade, and the durability of the supply path forming blade and the ink chamber wall forming blade can be improved. In addition, since the cutting direction is linear, there is an effect that a molding die with little error during processing and excellent in accuracy can be produced.

(1) Since the durability of the tool can be greatly improved, it is possible to stably supply a high-precision molding die. As a result, it is possible to provide an ink jet head with high density and little variation in ejection characteristics.

(2) Even in the case of an injection-molded ink jet head in which bubbles are relatively hard to flow, since the supply path penetrates the ink chamber and shares a partial cross section, the bubbles can easily flow along the cross section. For this reason, it is possible to provide an ink jet head having excellent bubble discharging properties by injection molding.

(3) The ink sealing property for sealing the flow path substrate is not affected by the surface roughness of the flow path substrate near the mold contact surface, and ink leakage is eliminated. As a result, the reliability of the ink jet head and its peripheral equipment is improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an ink jet head of the present invention.

FIG. 2 is a perspective view of a flow path substrate of the ink jet head of the present invention.

FIG. 3 is a perspective view of a molding die for a flow path substrate of the inkjet head of the present invention.

FIG. 4 is a perspective view of a flow path molding die piece of the present invention.

FIG. 5 is a perspective view for explaining a manufacturing process of a channel forming die piece of the present invention.

FIG. 6 is a perspective view for explaining a manufacturing process of the flow path molding die piece of the present invention.

FIG. 7 is a perspective view illustrating an example of an ink chamber wall forming blade.

FIG. 8 is a perspective view for explaining a manufacturing process of a peripheral molding die piece of the present invention.

FIG. 9 is a perspective view illustrating a manufacturing process of the molding die of the present invention.

FIG. 10 shows an ink chamber of the inkjet head of the present invention,
It is a perspective view of a supply path.

FIG. 11 is a perspective view illustrating the flow of bubbles.

FIG. 12 is a perspective view illustrating an effect of a groove.

FIG. 13 is a perspective view showing an inkjet head according to another embodiment of the present invention.

[Explanation of symbols]

 30 ‥‥ Sealing member 53 ‥‥ Common ink reservoir 58 凸 Convex portion 71 ‥‥ End mill 170 イ ン ク Ink chamber 210 気 泡 Bubbles 211 ‥‥ Bubbles 212 ‥‥ Bubbles 230 流 路 Flow path substrate 260 端 End face 261 ‥‥ End surface 262 ‥‥ End surface 263 端 End surface 280 接触 Contact surface 281 ‥‥ Contact surface 285 ‥‥ Bottom 340 ‥‥ Mold 341 流 路 Channel mold 342 ‥‥ Peripheral mold 343 供給 Supply Path forming groove 344 ‥‥ Ink chamber wall forming groove 345 ‥‥ Supply path forming blade 346 イ ン ク Ink chamber wall forming blade 347 共通 Common ink reservoir wall forming groove 348 ノ ズ ル Nozzle plate positioning hole forming protrusion 349 位置 決 め Positioning pin Hole 350 ノ ズ ル Nozzle plate positioning hole 351 駆 動 Drive unit positioning pin 352 ‥‥ Drive unit positioning hole 353溝 Groove 354 底 Ink chamber wall forming groove bottom

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41J 2/045 B23P 15/24 B41J 2/055 B41J 2/16

Claims (4)

(57) [Claims] An ink chamber connected to each of a plurality of nozzles, a supply path connected to the ink chamber, and a common ink reservoir connected to the supply path are formed by injection molding.
In a molding die for a flow path substrate of an ink jet head, wherein the molding die is formed by a plurality of frames , the molding die has a supply path forming groove that passes from one end to the other end.
Intersects with the supply path forming groove deeper than the supply path forming groove.
An ink chamber wall forming groove that passes from one end to the other
The flow for forming the ink chamber and the supply path.
Characterized in that it has at least a road forming die top.
Mold for the flow path substrate of the inkjet head. 2. The method according to claim 1, wherein the molding die includes the common ink reservoir.
It further has a peripheral molding die piece for molding,
The mold die piece and the flow path molding die piece are connected without any gap.
2. A molding die for a flow path substrate of an ink jet head according to claim 1, wherein the contact surface is arranged at a convex portion of the flow path molding die piece and the peripheral molding die piece. 3. A method for forming, by injection molding, an ink chamber communicating with each of a plurality of nozzles, a supply path communicating with the ink chamber, and a common ink reservoir connected to the supply path .
In a method of manufacturing a flow path substrate forming die of an ink jet head in which a forming die includes a plurality of frames , the forming die includes at least a flow path forming die top for forming the ink chamber and a supply path. A first feed path forming blade for moving the supply path forming blade straight to the flow path forming die piece to form a supply path forming groove extending from one end to the other end of the flow path forming die piece; And a step of causing the ink chamber wall forming blade to move straight in a direction intersecting with the supply path forming groove, and cutting the flow path forming die piece linearly deeper than the supply path forming groove, thereby forming the flow path forming metal. A second step of forming an ink chamber wall forming groove extending from one end to the other end of the die piece. 4. A peripheral molding metal for molding said common ink reservoir.
It also has a mold piece, and cuts the peripheral molding mold piece to be common
A first step of processing the ink reservoir walls forming groove, a second step of contacting without gaps therebetween by polishing sides of the peripheral molding die block and the flow path forming die block, the passage forming 4. The method according to claim 3, further comprising a third step of fixing the position of the die top and the peripheral forming die top relative to each other.