JP2024040897A - Molded product manufacturing method, liquid discharge head manufacturing method, molded product, and liquid discharge head - Google Patents

Abstract

[Problem] To provide a technology capable of efficiently and inexpensively manufacturing a molded product having a hollow portion. [Solution] A first molded product 51 and a second molded product 52 are integrally joined by molten resin injected into a molten resin flow path 540 formed between the first molded product 51 and the second molded product 52 to manufacture an integral molded product having a hollow portion. During the manufacturing, a communication path 550 that connects a predetermined hollow portion 530 among a plurality of hollow portions 530 formed in the integral molded product 50 to the molten resin flow path 540 is formed in at least one of the first molded product 51 and the second molded product 52. Thereafter, the first molded product 51 and the second molded product 52 are brought into contact with each other, and molten resin 80 is injected into the molten resin flow path 540, and the molten resin 80 is injected from the molten resin flow path 540 through the communication path 550 into the predetermined hollow portion 530. As a result, the predetermined hollow portion 530 is blocked by the molten resin 80. [Selected Figure] FIG. 7

Description

The present invention relates to a method for manufacturing a molded article having a hollow portion, a molded article manufactured by the manufacturing method, a method for manufacturing a liquid ejection head having a liquid flow path, and a liquid ejection head manufactured by the manufacturing method.

As a manufacturing method for manufacturing a molded product, Patent Document 1 discloses a method for manufacturing an integrated molded product by joining individually molded molded products to each other. In this manufacturing method, a molten resin is poured between two molded products formed by injection molding or the like and cured, thereby forming an integrally molded product. Manufacturing methods that use this type of joining method have higher reliability and strength of the joint compared to joining methods such as ultrasonic welding, vibration welding, hot plate welding, and laser welding, which melt and join the welded parts placed on molded products. It is known that it is possible to improve

On the other hand, in today's world where there is an increasing trend towards high-mix, low-volume production, variations of molded products are sometimes produced that have the same external shape but differ in the shape of the hollow part formed inside. An example of a molded product having such a hollow portion is a liquid ejection head mounted on a liquid ejection device. BACKGROUND ART A plurality of types of liquid ejection heads may be manufactured that have the same external shape but differ in the number of liquid flow paths (hollow portions) used. However, in this case, it is necessary to take measures to prevent a liquid storage tank for five colors from being attached to a liquid ejection head for four colors whose outer shape looks like five colors. For this reason, conventionally, a liquid ejection head in which one liquid supply port or liquid flow path in a liquid ejection head for five colors is closed is manufactured using a new mold. Furthermore, a liquid ejection head for four colors is also manufactured by covering the liquid supply ports of the liquid ejection head for five colors with a lid.

Japanese Patent Application Publication No. 9-33892

However, preparing a plurality of molds according to the molded product as described above leads to an increase in equipment cost and increases the manufacturing cost of the product. Further, in the case of adopting a configuration in which the liquid supply port is covered with a lid, a new mold for manufacturing the lid is required, and a manufacturing process for the lid is added, resulting in an increase in manufacturing costs.

The present disclosure provides a method for manufacturing a molded product and a method for manufacturing a liquid ejection head that can efficiently and inexpensively manufacture a molded product having a hollow portion, and a hollow molded product and a liquid ejection head manufactured by the manufacturing method. The purpose is to provide.

In the present disclosure, the first molded product and the second molded product are integrally joined by molten resin injected into a molten resin flow path formed between the first molded product and the second molded product, and a hollow portion A method for manufacturing a molded article for manufacturing an integrally molded article having a plurality of hollow portions, the method comprising: forming a communication path that communicates a predetermined hollow portion among the plurality of hollow portions with the molten resin flow path; a processing step performed on at least one of the first molded product and the second molded product; a contact step of bringing the first molded product and the second molded product into contact with each other; The molten resin is injected into the predetermined hollow part from the molten resin flow path via the communication path, and the predetermined hollow part is closed. A method for manufacturing molded products.

According to the method for manufacturing a molded article and the method for manufacturing a liquid ejection head according to the present disclosure, it is possible to efficiently and inexpensively manufacture a molded article having a hollow portion and a liquid ejection head.

FIG. 3 is a schematic cross-sectional view showing a method of joining molded products using molten resin. FIG. 3 is a schematic cross-sectional view showing the manufacturing process of a molded article. FIG. 3 is a diagram showing three different types of conventional liquid ejection heads. FIG. 3 is a schematic cross-sectional view of a liquid ejection head. FIG. 3 is a cross-sectional view showing a liquid ejection head in which one liquid supply port is rendered unusable by the manufacturing method of the present embodiment. 6 is a plan view of the liquid ejection head shown in FIG. 5. FIG. 6 is a schematic cross-sectional view for explaining a part of the manufacturing process of the liquid ejection head shown in FIG. 5. FIG.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that the following embodiments do not limit the claimed invention, and not all combinations of features described in the embodiments are essential to the solution of the invention. .

FIG. 1 is a schematic cross-sectional view showing a method of joining molded products using molten resin. Here, a process of joining the first molded product 1 and the second molded product 2 will be shown as molding to join them together. It is assumed that the first molded product and the second molded product 2 have been molded in advance by injection molding or the like. As shown in FIG. 1(a), the first molded product 1 is formed with a hollow portion 1a that penetrates from the upper surface to the lower surface in the figure. Similarly, the second molded product 2 is formed with a cylindrical hollow portion 2a that penetrates from the top surface to the bottom surface in the figure.

A concave portion 1b for forming a molten resin flow path C1 to be described later is formed on one surface (lower surface in the figure) of the first molded product 1 in combination with the second molded product 2, and on both sides of the concave surface portion 1b is formed. A blocking wall 1c is formed to block the flow of the molten resin flow path C1 (FIG. 1(b)) to the hollow portion. Similarly, a semi-cylindrical concave part 2b for forming a molten resin flow path C1 with a hollow part 2a in between is formed on one surface (upper surface in the figure) of the second molded product 2, and on both sides of the concave part 2b. A blocking wall 2c is formed.

When joining the first molded product 1 and the second molded product 2, as shown in FIG. 1(b), the blocking wall 1c of the first molded product 1 and the blocking wall 2c of the second molded product 2 are Bring it into contact. As a result, the concave surface portion 1b of the first molded product 1 and the concave surface portion 2b of the second molded product 2 form a cylindrical molten resin flow path C1 extending in a direction perpendicular to the paper plane of FIG. Further, the hollow portion 1a of the first molded product 1 and the hollow portion 2a of the second molded product 2 are in a state of communication with each other, and a hollow portion C2 is formed.

After that, the molten resin 3 is poured into the molten resin channel C1, and the molten resin channel C1 is filled with the molten resin 3. At this time, communication between the molten resin flow path C1 and the hollow section C2 is blocked by the contact between the blocking wall 1c and the blocking wall 2c, so the molten resin 3 does not flow into the hollow section C2. When the molten resin in contact with the concave surface portion 1b of the first molded product 1 and the concave surface portion 2b of the second molded product 2 solidifies, the first molded product 1 and the second molded product 2 are joined to each other, and the hollow portion C2 is An integrally molded product 4 is formed. In FIG. 1, the first molded product 1 and the second molded product 2 each have concave portions 1b and 2b, but the concave portion is formed on either the first molded product 1 or the second molded product 2. may be formed only. Moreover, although the blocking walls 1c and 2c are provided on each side, the blocking walls may not be provided in the portions other than the hollow portion C2 that allow the molten resin 3 to flow. If the molten resin can be received by the mold, problems such as deformation of the molded product can be suppressed.

In the above joining method, when the molten resin flow path C1 has a larger cross-sectional area and a shorter length, it becomes easier to flow the molten resin 3 to a desired portion of the molten resin flow path C1. Furthermore, there may be a plurality of locations (molten resin injection gates) into which the molten resin 3 is poured. Further, the molten resin may be the same material as the first molded product 1 and the second molded product 2, or may be a different material. Note that the first molded product 1 and the second molded product shown here represent part of a flow path member of a liquid ejection head that will be described later.

FIG. 2 is a schematic cross-sectional view showing the manufacturing process of the molded product. In the example shown in FIG. 2, the first step shown in FIG. 2(a) to the fifth step shown in FIG. 5(e) are sequentially performed. Each step will be explained below. ((A) First, in the first step shown in FIG. 2(a), a molding space is formed between the clamped first mold (fixed mold) 7 and second mold (movable mold) 8. The resin injected from the fixed injection nozzle 9 is injected into the fixed mold 7 through the channel 7a and the gate 7b.Thereby, the first molded product 11 and the second molded product 12 are formed.
(B) Next, in the second step shown in FIG. 2(b), the movable mold 8 is moved in the X2 direction with respect to the fixed mold 7 to open the mold. In this mold open state, the movable mold 8 holds the first molded product 11, and the fixed mold 7 holds the second molded product 12.
(C) Next, in the third step shown in FIG. 2(c), the movable mold 8 is moved in the Y1 direction, and the first molded product 11 held by the movable mold 8 is transferred to The second molded product 12 is made to face the second molded product 12.
(D) Next, the movable mold 8 is moved in the X1 direction with respect to the fixed mold 7, and the first molded product 11 and the second molded product 12 are combined by clamping the molds. As a result, a joining channel 14 is formed between the first molded product 11 and the second molded product 12. Here, the molten resin is injected from the movable injection nozzle 16 into the flow path 8a formed in the movable mold 8. The molten resin injected into the flow path 8a flows into the joining flow path 14 through the gate 8b and the flow path 11a formed in the first molded product 11. By solidifying this molten resin, the first molded product 11 and the second molded product 12 are joined to form an integrally molded product.
(E) After this, in the fifth step shown in FIG. 2(e), the movable mold 8 is moved in the X2 direction to open the mold. As a result, the integrally molded product 17 is released from the fixed mold 7 and taken out.

In the case of the above manufacturing method, by employing a hot runner system, the position of the gate 8b during multi-stage injection can be switched only by switching the valve gate. That is, after molding the first molded product 1 and the second molded product 2, by switching the valve gate and then performing joining using the molten resin 3, it becomes possible to manufacture an integrally molded product within one mold. This makes it possible to reduce the equipment cost compared to the case where the molded products are individually molded and individually supplied and then joined to each other. In other words, according to the above manufacturing method, the steps from molding the first molded product 11 and the second molded product 12 to joining the first molded product 11 and the second molded product 12 can be performed within one apparatus, Equipment costs can be reduced. However, the above manufacturing method is just an example, and even when injection molding is used, the molten resin 3 can be moved by using a robot to move the molded product or by rotating the mold, without using the slide of the mold. You may move it to the pouring position.

An example of a molded product manufactured by the above manufacturing method is a liquid ejection head mounted on a liquid ejection device such as an inkjet recording device. FIG. 3 is a diagram showing three different types of conventional liquid ejection heads; (a) shows liquid ejection head HA of model A, (b) shows liquid ejection head HB of model B, and (c) shows the liquid ejection head HB of model B. Each of the liquid ejection heads HC of C is shown. 3(a), (b), and (c), (a1), (b1), and (c1) are for the case where the liquid ejection direction of each liquid ejection head HA, HB, and HC is set downward in the direction of gravity. A plan view, (a2), (b2), and (c2) are front views, and (a3), (b3), and (c3) are bottom views.

The liquid ejection head HA shown in FIG. 3A is a liquid ejection head that is capable of ejecting five types of liquid (for example, five colors of ink). The liquid ejection head HA is provided with five liquid supply ports 21 to 25 for supplying five types of liquid, and flow paths (not shown) communicating with these ports. Further, on the bottom surface of the liquid ejection head HA, as shown in the bottom view (a3), a liquid ejection substrate 40 in which ejection ports are formed to eject the liquid supplied to the liquid supply ports 21, and supply ports 22 to 25 are provided. A discharge port substrate 41 in which a discharge port for discharging the liquid supplied to the substrate is formed is provided. Here, the portions other than the discharge port substrates 40 and 41 are formed by injection molding or the like.

Further, the liquid ejection head HB shown in model B is a liquid ejection head that is capable of ejecting four types of liquid (for example, four colors of ink). The liquid ejection head HB is provided with five liquid supply ports 22 to 25 for supplying four types of liquid, and flow paths (not shown) communicating with these ports. Furthermore, as shown in the bottom view (b3), an ejection port substrate 41 is provided on the bottom of the liquid ejection head HB, in which ejection ports are formed to eject the liquid supplied to the supply ports 22 to 25. . Here, the portions other than the discharge port substrate 41 are constituted by a molded product formed by injection molding or the like.

As shown in FIGS. 3(a) and 3(b), the liquid ejection head HA of model A and the liquid ejection head HB of model B have the same external shape, but have a hollow supply port and a flow path. The number of is different. When manufacturing such liquid ejection heads HA and HB, molds are used that correspond to the respective liquid ejection heads HA and HB. That is, when manufacturing the liquid ejection head HB, it is manufactured using a mold that closes the liquid supply port 21 of the liquid ejection head HA to form an unused portion. Therefore, when manufacturing the liquid ejection head HA shown in FIG. 3(a) and the liquid ejection head HB shown in FIG. 3(b), two types of molds are required, which increases the manufacturing cost. There is.

Further, the liquid ejection head HC shown in FIG. 3(c) is a liquid ejection head that is capable of ejecting eight types of liquid (for example, eight colors of ink). The liquid ejection head HC is formed with eight liquid supply ports 21 to 28 for supplying eight types of liquids and flow paths (not shown) communicating with these ports. Furthermore, as shown in the bottom view (c3), the bottom surface of the liquid ejection head HA includes an ejection port substrate 42 in which ejection ports are formed to eject the liquid supplied to the liquid supply ports 21 to 24; A discharge port substrate 43 is provided in which a discharge port for discharging the liquid supplied to 25 to 28 is formed. Here, the portions other than the discharge port substrates 42 and 43 are constituted by a molded product formed by injection molding or the like.

This liquid ejection head HC has the same external shape as a liquid ejection head that is capable of ejecting 10 types of liquid (for example, 10 colors of ink). Therefore, since there is a risk that the user may accidentally attach 10 types of liquid storage tanks, the area corresponding to the forming portions of the two supply ports of the liquid ejection head capable of ejecting 10 types of liquids is removed from the lid member 32. is blocked by When manufacturing such a liquid ejection head HC, a lid member and a mold for manufacturing it are required, as well as personnel to mount the lid member, which increases manufacturing costs. It becomes a factor that invites Furthermore, in the case where two types of molds are provided corresponding to two types of liquid ejection heads without providing a lid member, the manufacturing cost due to the molds increases.

FIG. 4(a) is a schematic cross-sectional view showing the cross-sectional structure of a liquid ejection head HD formed by joining molded products with molten resin, and FIG. 4(b) is a cross-sectional diagram shown by a dashed line in FIG. It is an enlarged view showing the enclosed part.

The liquid ejection head HD includes an integrally molded product 50 in which a first molded product 51 and a second molded product 52 are bonded together using molten resin, and a liquid ejection substrate 60 that is provided with a discharge port for discharging liquid and a discharge energy generating element. Equipped with. Furthermore, the liquid ejection head HD includes a metal filter 56 that covers the opening of the first molded product 51 as an insert component. The liquid ejection head HD shown here is capable of ejecting five types of liquids, and the liquid ejection substrate 60 is provided with ejection port groups consisting of a plurality of ejection ports corresponding to each of the five types of liquid. . A hollow portion 520 is formed in the second molded product 52 . This hollow portion 520 forms part of five channels (not shown) communicating with each ejection port group of the liquid ejection substrate 60. Further, the first molded product 51 is formed with liquid supply ports 510 as five hollow portions that communicate with each flow path of the second molded product 52 .

Different types of liquids are supplied to each of the liquid supply ports 510 of the first molded product 51 from five liquid storage tanks 71 to 75. Thereafter, the liquid is supplied to the liquid ejection substrate 60 through the flow path formed in the second molded product 52, and is filled into each ejection port. The liquid filled in the ejection port is ejected by driving the ejection energy generating element in response to an ejection signal from the liquid ejection device. In the illustrated example, five independent first molded products 51 each having a hollow cylindrical shape are joined to the second molded product 52, but the five first molded products 51 are It may be a single molded product.

As shown in FIG. 4(b), the first molded product 51 and the second molded product 52 form a molten resin flow path 540 by concave portions 51b and 52b formed on surfaces that contact each other. Furthermore, a hollow portion (liquid channel) 530 in the integrally molded product 50 is formed by the liquid supply port 510 of the first molded product 51 and 520 formed in the second molded product 52 . Liquid communication between the liquid flow path 530 and the molten resin flow path 540 is cut off. This is similar to the relationship between the molten resin flow path C1 and the hollow portion C2 shown in FIG. 1(b). A molten resin 80 is injected into the molten resin channel 540 as in FIG. 1(c), and as the molten resin 80 solidifies, the first molded product 51 and the second molded product 52 are joined to each other.

(Liquid ejection head unique to this embodiment and its manufacturing method)
Here, a liquid ejection head unique to this embodiment and a method for manufacturing the same will be described. FIG. 5 is a cross-sectional view of the liquid ejection head HE in which one of the liquid supply ports 510 of the liquid ejection head HD described above is rendered unusable. Note that FIG. 5(a) is a sectional view showing the overall structure of the liquid ejection head HE, FIG. 5(b) is an enlarged sectional view showing the portion surrounded by the dashed line in FIG. 5(a), and FIG. FIG. 5 is a plan view of the liquid ejection head shown in FIG. 5(a).

Like the liquid ejection head HD shown in FIG. 4, the liquid ejection head HE shown in FIG. is the same as the liquid ejection head HD shown in FIG. However, the liquid ejection head HD has a configuration in which one liquid supply port 510 in the first molded product 51 is filled with molten resin 80 and the liquid supply port 510 is closed. That is, the liquid ejection head HE shown in FIG. 5 corresponds to a variation of the liquid ejection head HD shown in FIG. 4.

The molten resin is supplied and filled into the liquid supply port 510 via a communication path 550 that communicates the liquid supply port 510 with a molten resin channel 540 formed by the first molded product 51 and the second molded product 52. conduct. That is, a part of the molten resin supplied to the molten resin flow path 540 is caused to flow into the liquid supply port 510 via the communication path 550.

As shown in FIG. 6, the liquid ejection head HE configured in this manner has a configuration in which the molten resin 80 exists in a portion where the filter 56 would normally exist, and the liquid supply port 510 is closed. Therefore, the user can easily visually confirm that the liquid storage tank cannot be attached to the portion where the molten resin 80 is present. Furthermore, if a written part indicating that the liquid storage tank cannot be installed is formed at or near the part blocked by the molten resin 80, it is possible to more reliably prevent the user from installing the liquid storage tank. It becomes possible. The written part can be added by laser engraving after the molded product is manufactured, but the written part is molded onto the surface of the molten resin when it flows into the liquid supply port and solidifies. It is also possible to engrave the written portion on the mold for molding the molded product. When engraving written parts on a mold, the written parts are formed near all liquid supply ports, and the written parts formed near the liquid supply ports that are not filled with molten resin are covered with a filter 56. , so that it is not visible from the outside. Furthermore, since the recording section formed near the supply port for filling resin is not covered by the filter 56, it can be visually recognized from the outside. According to this, even when changing the supply port for filling with molten resin, it is possible to manufacture a molded product using a common mold.

Note that the molten resin 80 does not need to fill the entire area of the hollow portion (in the example shown in FIG. 5, the liquid supply port 510 and the hollow portion 520), but should be filled only in the portion that is visible to the user. However, it is possible to achieve the intended purpose. According to this, it becomes possible to suppress the consumption amount of molten resin.

FIG. 7 is a schematic cross-sectional view for explaining a part of the manufacturing process of the liquid ejection head HE shown in FIG. 5(a). Note that FIG. 7 shows only the portion surrounded by the dashed line in FIG. 5(a).

First, the first molded product 51 and the second molded product 52 are formed by injection molding or the like. Thereafter, as shown in FIG. 5(a), heat is applied to a position facing the blocking wall 52c located on both sides of a desired hollow part 520 among the five hollow parts 520 formed in the second molded product 52. Position the processing horn 90. Next, the processed surface 90a of the heat processing horn 90 heated to a desired temperature is pressed against the blocking walls 52c located on both sides of the hollow portion 520, and the blocking walls 52c are deformed and removed while being heated and melted. A concave communication path 550 is formed. Thereafter, the heat processing horn 90 is retracted from the position facing the second molded product 52 (FIG. 5(c)), and the first molded product 51 is moved to face the second molded product 52 (FIG. 7(d)). Furthermore, as shown in FIG. 7(e), the first molded product 51 is moved to a contact position where it contacts the second molded product 52. As a result, a liquid channel 530 is formed by the liquid supply channel 510, which is the hollow part of the first molded product 51, and the hollow part 520 of the second molded product 52, and the concave part 51b of the first molded product 51 and the second A molten resin flow path 540 is formed by the concave surface portion 52b of the molded product 52. Further, the molten resin flow path 540 and the liquid flow path 530 communicate with each other via the communication path 550.

Thereafter, the molten resin 80 injected from an injection nozzle (not shown) is injected into the molten resin flow path 540, and the molten resin flow path 540 is filled with the molten resin. Further, the molten resin 80 injected into the molten resin flow path 540 flows into the liquid flow path 530 through the communication path 550 and fills the liquid flow path 530, as shown in FIG. 7(f). Then, when the molten resin 80 filled in the molten resin channel 540 and the liquid channel 530 is solidified, the first molded product 51 and the second molded product 52 are joined, and the integrally molded product 50 is formed. A liquid ejection substrate 60 is fixed to this integrally molded product 50, as shown in FIG. 5, and a liquid ejection head HE is manufactured.

Note that the method for manufacturing the molded product shown in FIG. 7 can also be carried out using the first molded product 51 and the second molded product that are individually molded in advance, but as shown in FIG. It is also possible to mold the product 51 and the second molded product, join the two molded products, and close the hollow portion using the same mold. That is, as shown in FIG. 2(a), after molding the first molded product 51 and the second molded product using the fixed mold 7 and the movable mold 8, as shown in FIGS. 2(b) and 2(c), The fixed mold 7 and the movable mold 8 are opened, and the movable mold 8 is moved so that the second molded product 52 faces the first molded product 51. After this, in this embodiment, the steps shown in FIGS. 7(a) to 7(c) described above are performed to form the communication passage 550 in the second molded product 52. Thereafter, as shown in FIG. 2(d), the movable mold is moved to bring the first molded product 51 and the second molded product 52 into contact, and the molten resin is injected into the molten resin flow path 540. ) Mold the molded product shown in (). The molten resin may be injected through a channel formed in the first molded product, as shown in FIG. 2, or the molten resin may be directly injected from the mold into the molten resin channel. As described above, in this embodiment, after the first molded product 51 and the second molded product 52 are molded, the first molded product 51 is moved to the contact position with the second molded product 52 as shown in FIG. 2(d). Prior to carrying out the movement step of moving to , the processing steps shown in FIGS. 7(a) to 7(c) are performed. This point is different from the manufacturing method shown in FIG.

As described above, according to the manufacturing method of the present embodiment, a predetermined hollow part that is formed in the first molded product 51 and the second molded product 52 and becomes unnecessary among the plurality of hollow parts (liquid flow paths) 530 is , the molten resin 80 injected into the molten resin channel 540 can be poured to close the hollow portion. Therefore, while using one mold in common, it is possible to increase the variety of molded products and liquid ejection heads using the same. Therefore, it becomes possible to suppress the equipment cost of the manufacturing apparatus for molded products and liquid ejection heads, and it becomes possible to reduce the product costs of molded products and liquid ejection heads. Furthermore, in this embodiment, by injecting molten resin to join the molded products, it is also possible to close unnecessary hollow portions formed in the molded products. Therefore, according to this embodiment, the number of processes can be reduced and manufacturing efficiency can be improved compared to the case where the process of joining the molded products and the process of closing the hollow part are performed separately. .

In addition, in the manufacturing method shown in FIG. 7, if the communication path 550 is processed by the heat processing horn 90, and then a blowing means is used to cool it and apply a coating that is excellent in mold release, the process can be made more efficiently and stably. The communication path 550 can be formed into a desired shape. Further, when processing the communication passage 550, it is also possible to use different thermal processing horns depending on the position and shape of the processed portion, and form the communication passage 550 into a desired shape and surface roughness.

Further, if the thermal processing horn 90 is attached to the tip of a six-axis robot, processing can be performed at any position, and the formation position of the communication path 550 can be changed for each molding.

Further, when a robot or the like is used for moving molded products, assembling molded products with each other, or supplying insert parts, the robot may be provided with a heat processing horn. According to this, it becomes possible to use the heat-processed horn in common in manufacturing various liquid ejection heads, and it is possible to suppress an increase in equipment costs. However, depending on the size of the mold and the amount of mold opening, the 6-axis robot may not be able to enter, so in that case, an electric cylinder or the like may be used.

In order for the molten resin 80 to smoothly flow into the hollow portion 530, it is preferable that the size (cross-sectional area) of the communicating path 550 is large. Further, by providing a region into which the molten resin 80 flows, even when the amount of molten resin varies, it becomes possible to absorb the variation. However, it is undesirable that the molten resin 80 flows only into the hollow portion (for example, the liquid channel 530) and the supply of molten resin to the molten resin channel 540 becomes insufficient. Further, it is preferable that the position where the processed portion is formed is closer to the gate through which the molten resin is injected into the molded product, since the temperature and pressure of the molten resin will decrease less. Therefore, it is preferable that the position where the communication path 550 is formed and the size of the communication path 550 are determined comprehensively, taking into consideration the size of the molten resin flow path 540, the time required for processing, and the like.

In addition, as shown in FIG. 5, there is a case where the first molded product 51 and the second molded product 52 are joined and unnecessary hollow parts are closed, and a case where the hollow parts are not closed as shown in FIG. The amount of molten resin required differs depending on the case of manufacturing the product. Further, the time for opening the mold holding the first molded product and the mold holding the second molded product 52 is different depending on whether a processed portion is formed or a processed portion is not formed. Therefore, it is preferable that the molding machine can be set to a mode corresponding to a product that closes the hollow part and a product that does not block the hollow part.

(Other embodiments)
In the above embodiment, the communication path 550 is formed in the second molded product 52 in order to form the communication path 550 that communicates the molten resin flow path 540 and the liquid flow path 530, but the present invention is not limited thereto. That is, it is also possible to form a communicating path by forming a processed portion in the first molded product 51. Further, the communicating path may be formed by forming processed parts on both the first molded product 51 and the second molded product 52. Furthermore, although an example has been shown in which the communication path 550 is formed using the heat-processed horn 90, it is also possible to form the communication path 550 by cutting.

Furthermore, the method for manufacturing a molded product according to the present disclosure is applicable to all situations in which an integrally molded product having a hollow portion is manufactured by joining molded products together, and is not limited to manufacturing a liquid ejection head.

Note that the present disclosure includes the following methods and configurations.

(Method 1)
The first molded product and the second molded product are integrally joined by molten resin injected into a molten resin flow path formed between the first molded product and the second molded product, and integral molding having a hollow part is formed. A method for manufacturing a molded article, the method comprising:
forming a communication path in at least one of the first molded product and the second molded product, which communicates a predetermined hollow part among the plurality of hollow parts with the molten resin flow path;
a contacting step of bringing the first molded product and the second molded product into contact with each other;
an injection step of injecting the molten resin into the molten resin flow path into the predetermined hollow portion from the molten resin flow path via the communication path, and closing the predetermined hollow portion; A method for manufacturing a molded article, comprising:

(Method 2)
The forming step is performed by removing a part of a blocking wall that blocks communication between the molten resin flow path and the hollow portion when the first molded product and the second molded product are brought into contact with each other. A method for producing a molded article according to Characteristic Method 1.

(Method 3)
According to method 1 or 2, in the injection step, the molten resin is injected to a position where it can be visually confirmed from the outside of the integrally molded product that the predetermined hollow part is closed by the molten resin. Method of manufacturing molded products.

(Method 4)
4. The method for producing a molded article according to any one of methods 1 to 3, wherein the molten resin is different from at least one of the resin constituting the first molded article and the resin constituting the second molded article.

(Method 5)
5. The method for manufacturing a molded product according to any one of methods 1 to 4, wherein the integrally molded product includes an insert component.

(Method 6)
The method for manufacturing a molded article according to method 5, wherein the insert part is a metal filter that covers only the opening of the hollow portion that is not blocked by the molten resin.

(Method 7)
The first molded product and the second molded product are formed of resin injected into a molding space formed between a clamped first mold and a second mold,
In the forming step, after opening the first mold and the second mold, the first molded product held in the first mold and the second molded product held in the second mold are separated. forming the flow path in at least one of the second molded products;
In the abutting step, the first molded product and the second molded product are moved by moving at least one of the first molded product held in the first mold and the second molded product held in the second mold. Move to the contact position where the two molded products come into contact,
Molding according to any one of methods 1 to 6, wherein the injection step includes injecting the molten resin into the molten resin flow path from a gate formed in the first mold or the second mold. method of manufacturing the product.

(Method 8)
A method for manufacturing a liquid ejection head comprising a flow path member in which a plurality of hollow portions forming a plurality of liquid flow paths are formed, and a liquid ejection substrate that ejects liquid supplied through the flow path member. hand,
a forming step of forming a process on at least one of the first molded product and the second molded product to form a communication path that communicates a predetermined hollow part among the plurality of hollow parts with the molten resin flow path; and,
a contacting step of bringing the first molded product and the second molded product into contact with each other;
an injection step of injecting the molten resin into the molten resin flow path into the predetermined hollow portion from the molten resin flow path via the communication path, and closing the predetermined hollow portion; and forming the flow path member,
A method of manufacturing a liquid ejection head, comprising: attaching the liquid ejection head to the flow path member.

(Method 9)
9. The method for manufacturing a liquid ejection head according to method 8, wherein in the injection step, the molten resin is injected to a position where it can be visually confirmed that the liquid flow path is blocked by the molten resin.

(Method 10)
10. The method for manufacturing a liquid ejection head according to configuration 8 or 9, wherein the molten resin is different from the resin constituting at least one of the first molded product and the second molded product.

(Method 11)
11. The method for manufacturing a liquid ejection head according to any one of methods 8 to 10, wherein the flow path member includes an insert component.

(Method 12)
12. The method for manufacturing a liquid ejection head according to method 11, wherein the insert component is a metal filter that covers an opening of the liquid flow path.

(Configuration 1)
A molded product including a first molded product and a second molded product integrally joined to each other by molten resin, and having a hollow portion inside,
A molded article characterized in that at least a part of a predetermined hollow part among the plurality of hollow parts is closed by the molten resin.

(Configuration 2)
The molded article according to configuration 1, wherein the molten resin is different from a resin constituting at least one of the first molded article and the second molded article.

(Configuration 3)
The molded product according to configuration 1 or 2, wherein the molded product includes an insert component.

(Configuration 4)
The molded product according to configuration 3, wherein the insert part is a metal filter that covers the opening of the predetermined hollow part.

(Configuration 5)
A flow path member having a plurality of hollow portions and having a configuration in which a first molded product and a second molded product are integrally joined by molten resin, and a liquid discharge substrate that discharges the liquid supplied through the flow path member. A liquid ejection head comprising:
In the liquid ejection head, at least a portion of a predetermined hollow portion of the plurality of hollow portions of the flow path member is closed with molten resin.

(Configuration 6)
6. The liquid ejection head according to configuration 5, wherein the molten resin is different from at least one of the resin constituting the first molded product and the resin constituting the second molded product.

(Configuration 7)
7. The liquid ejection head according to configuration 5 or 6, wherein the flow path member includes an insert component.

(Configuration 8)
8. The liquid ejection head according to configuration 7, wherein the insert component is a metal filter that covers an opening of the predetermined liquid flow path.

50 Integrally molded product 51 First molded product 52 Second molded product 80 Molten resin 530 Liquid flow path (hollow part)
540 Molten resin flow path 550 Communication path

Claims (20)

The first molded product and the second molded product are integrally joined by molten resin injected into a molten resin flow path formed between the first molded product and the second molded product, and integral molding having a hollow part is formed. A method for manufacturing a molded article, the method comprising:
forming a communication path in at least one of the first molded product and the second molded product, which communicates a predetermined hollow part among the plurality of hollow parts with the molten resin flow path;
a contacting step of bringing the first molded product and the second molded product into contact with each other;
an injection step of injecting the molten resin into the molten resin flow path into the predetermined hollow portion from the molten resin flow path via the communication path, and closing the predetermined hollow portion; A method for manufacturing a molded article, comprising: The forming step is performed by removing a part of a blocking wall that blocks communication between the molten resin flow path and the hollow portion when the first molded product and the second molded product are brought into contact with each other. The method for manufacturing a molded article according to claim 1. 3. The injecting step includes injecting the molten resin to a position where it can be visually confirmed from the outside of the integrally molded product that the predetermined hollow part is closed by the molten resin. A method for manufacturing molded products. 2. The method for manufacturing a molded article according to claim 1, wherein the molten resin is different from at least one of the resin constituting the first molded article and the resin constituting the second molded article. The method for manufacturing a molded product according to claim 1, wherein the integrally molded product includes an insert component. 6. The method for manufacturing a molded product according to claim 5, wherein the insert component is a metal filter that covers only an opening of the hollow portion that is not blocked by the molten resin. The first molded product and the second molded product are formed of resin injected into a molding space formed between a clamped first mold and a second mold,
In the forming step, after opening the first mold and the second mold, the first molded product held in the first mold and the second molded product held in the second mold are separated. forming the flow path in at least one of the second molded products;
In the abutting step, the first molded product and the second molded product are moved by moving at least one of the first molded product held in the first mold and the second molded product held in the second mold. Move to the contact position where the two molded products come into contact,
The method for manufacturing a molded article according to claim 1, wherein the injection step includes injecting the molten resin into the molten resin flow path from a gate formed in the first mold or the second mold. . A method for manufacturing a liquid ejection head comprising a flow path member in which a plurality of hollow portions forming a plurality of liquid flow paths are formed, and a liquid ejection substrate that ejects liquid supplied through the flow path member. hand,
forming a communication path in at least one of the first molded product and the second molded product, which communicates a predetermined hollow part among the plurality of hollow parts with the molten resin flow path;
a contacting step of bringing the first molded product and the second molded product into contact with each other;
an injection step of injecting the molten resin into the molten resin flow path into the predetermined hollow portion from the molten resin flow path via the communication path, and closing the predetermined hollow portion; and forming the flow path member,
A method of manufacturing a liquid ejection head, comprising: attaching the liquid ejection head to the flow path member. 9. The method of manufacturing a liquid ejection head according to claim 8, wherein in the injection step, the molten resin is injected to a position where it can be visually confirmed that the liquid flow path is blocked by the molten resin. 10. The method of manufacturing a liquid ejection head according to claim 8, wherein the molten resin is different from resins constituting at least one of the first molded product and the second molded product. 9. The method of manufacturing a liquid ejection head according to claim 8, wherein the flow path member includes an insert component. 12. The method of manufacturing a liquid ejection head according to claim 11, wherein the insert component is a metal filter that covers an opening of the liquid flow path. A molded product including a first molded product and a second molded product integrally joined to each other by molten resin, and having a hollow portion inside,
A molded article characterized in that at least a part of a predetermined hollow part among the plurality of hollow parts is closed by the molten resin. 14. The molded article according to claim 13, wherein the molten resin is different from at least one of the resin constituting the first molded article and the resin constituting the second molded article. The molded product according to claim 13 or 14, wherein the molded product includes an insert component. 16. The molded product according to claim 15, wherein the insert part is a metal filter that covers an opening of the predetermined hollow part. A flow path member having a plurality of hollow portions and having a configuration in which a first molded product and a second molded product are integrally joined by molten resin, and a liquid discharge substrate that discharges the liquid supplied through the flow path member. A liquid ejection head comprising:
In the liquid ejection head, at least a portion of a predetermined hollow portion of the plurality of hollow portions of the flow path member is closed with molten resin. 18. The liquid ejection head according to claim 17, wherein the molten resin is different from at least one of the resin constituting the first molded product and the resin constituting the second molded product. The liquid ejection head according to claim 17 or 18, wherein the flow path member includes an insert component. 20. The liquid ejection head according to claim 19, wherein the insert component is a metal filter that covers an opening of the predetermined liquid flow path.

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