JP2007021990A - Joining structure, joining method and recording head unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve the reliable focusing of a laser beam on the boundary between members and the reliable laser welding of the members. <P>SOLUTION: A joining method comprises joining a transparent member 1 composed of a material transmissive to a laser beam with an absorbing member 2 composed of a material absorbing the laser beam. The transparent member 1 has a focusing section 3 focusing the laser beam, on the joining surface S of the transparent member 1 and the absorbing member 2, and the transparent member 1 and the absorbing member 2 are welded together by focusing the laser beam on the joining surface S of the transparent member 1 and the absorbing member 2 through the focusing section 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a joining structure and method, and a recording head unit.

When joining the members, one member is formed of a material that is transparent to laser light, the other member is formed of a material that absorbs laser light, There is a case in which a laser welding technique for joining one member and the other member by condensing laser light at an interface with the member is used (see, for example, Patent Document 1).
According to such a technique, the laser beam is condensed at the interface between the members and absorbed by the other member, so that the temperature at the interface between the members increases, so one member and the other member. And are dissolved. For this reason, it can join by welding one member and the other member.
JP 2002-331588 A

By the way, in order to raise the temperature of the interface between a member and a member, it is necessary to focus a laser beam on the interface between a member and a member as mentioned above. For this reason, conventionally, a condensing lens is used to condense laser light in accordance with the interface between the members.
However, when the laser welding technique is applied to the joining of complicated members, the installation space for the condenser lens cannot be ensured, and the laser welding technique may not be used. For example, one member (a member formed of a material that is transparent to laser light) has a groove, and the bottom of the groove is formed of the other member (a material that absorbs laser light). When the groove portion is smaller than the condensing lens, the condensing lens cannot be disposed inside the groove portion, and the focal length of the condensing lens is limited. It becomes impossible to focus the laser beam on the interface.

  The present invention has been made in view of the above-described problems, and it is an object of the present invention to make it possible to reliably focus laser light on the interface between a member and the member, and to reliably weld the member and the member. .

  In order to achieve the above object, in the joining structure of the present invention, a joining structure of a transparent member formed of a material that is transparent to laser light and an absorbing member formed of a material that absorbs the laser light. The transparent member includes a condensing part that condenses the laser light on a joint surface between the transparent member and the absorbing member, and the laser light is absorbed through the condensing part. The transparent member and the absorbing member are welded by being condensed on the joint surface with the member.

  According to the joining structure of the present invention having such characteristics, the condensing unit that condenses the laser light is provided on the transparent member. For this reason, when joining a transparent member and an absorption member by laser welding, it becomes unnecessary to arrange | position the condensing lens for condensing a laser beam separately. Therefore, as long as the laser beam reaches the condensing part, it is possible to condense the laser beam on the interface between the transparent member and the absorbing member, and securely join the transparent member and the absorbing member. And since the joining structure of this invention joins a transparent member and an absorption member in this way, a transparent member and an absorption member will be joined reliably.

Note that, in the joint structure of the present invention, specifically, a configuration in which the condensing part is a spherical lens, a cylindrical lens, or a Fresnel lens can be employed.
For example, if the condensing part is a spherical lens, it can be suitably performed when spot welding the transparent member and the absorbing member.
Moreover, if a condensing part is a cylindrical lens, it can carry out suitably when welding a transparent member and an absorption member over a long distance.
Further, if the light collecting portion is a Fresnel lens, the height of the light collecting portion itself can be suppressed.

Next, the recording head unit of the present invention has the joining structure of the present invention.
Since the joint structure of the present invention is a structure in which the transparent member and the absorbing member are securely joined, according to the recording head unit of the present invention having such a joint structure, for example, a member having a complex shape and a complex shape These members are securely joined to each other.

  Next, the joining method of the present invention is a joining method of a transparent member formed of a material having a light-transmitting property to laser light and an absorbing member formed of a material that absorbs the laser light. The transparent member includes a condensing part that condenses the laser light on a joint surface between the transparent member and the absorbing member, and the laser light is joined to the transparent member and the absorbing member through the condensing part. The transparent member and the absorbing member are welded by condensing the light into the light.

  According to the joining method of the present invention having such characteristics, the condensing part for condensing the laser beam is provided on the transparent member. For this reason, when joining a transparent member and an absorption member by laser welding, it becomes unnecessary to arrange | position the condensing lens for condensing a laser beam separately. Therefore, as long as the laser beam reaches the condensing part, it is possible to condense the laser beam on the interface between the transparent member and the absorbing member, and securely join the transparent member and the absorbing member.

Moreover, in the joining method of this invention, the said condensing part can employ | adopt the structure that it forms simultaneously when forming the said transparent member by injection molding.
By adopting such a configuration, the light condensing part is formed simultaneously with the formation of the transparent member. For this reason, it becomes unnecessary to perform the process for forming a condensing part separately, and it becomes possible to form a transparent member provided with a condensing part easily.

  Hereinafter, an embodiment of a joining structure and method and a recording head unit according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size.

(Joint structure and method)
FIG. 1 is a perspective view schematically showing the joint structure of the present embodiment. As shown in this figure, the joining structure of the present embodiment is a joining structure of the transparent member 1 and the absorbing member 2.

The transparent member 1 is formed of a material having transparency with respect to laser light used when the transparent member 1 and the absorbing member 2 are joined. The absorbing member 2 is formed of a material that absorbs the laser light described above.
In addition, as a material which forms the transparent member 1, polyester resins, such as a polyethylene terephthalate (PET) and a polybutylene terephthalate, a polyamide resin, a vinyl chloride resin, a fluororesin etc. can be used. In addition, as a material for forming the absorbing member 2, a resin having a functional group that absorbs laser light, or a material for forming the transparent member 1 in which carbon black or a coloring pigment is blended can be used.
As shown in FIG. 1, the transparent member 1 and the absorbing member 2 are welded in a state where the lower surface 11 (see FIG. 2) of the transparent member 1 and the upper surface 21 (see FIG. 3) of the absorbing member 2 are in contact with each other. Has been.

And in the junction structure of this embodiment, the condensing lens 3 (condenser part) for condensing a laser beam on the junction surface S (interface) of the transparent member 1 and the absorption member 2 is the transparent member 1. It is formed on the upper surface 12. When a predetermined laser beam (used when the transparent member 1 and the absorbing member 2 are bonded) is incident on the condensing lens 3, the laser beam is condensed on the bonding surface S.
The parameters such as the wavelength of the laser beam and the refractive index of the transparent member 1 and the condensing lens 3 necessary for condensing the laser beam on the bonding surface S are set before the transparent member 1 and the absorbing member 2 are bonded. Obtainable. For this reason, the shape of the condensing lens 3 can be easily set based on parameters that can be obtained in advance.
And as shown in FIG. 1, in the junction structure of this embodiment, the condensing lens 3 is comprised as a spherical lens.

  According to such a joining structure of the present embodiment, laser light is incident on the condensing lens 3 formed on the upper surface 12 of the transparent member 1, so that the laser is applied to the joining surface S between the transparent member 1 and the absorbing member 2. Light can be collected. For this reason, it is not necessary to separately arrange a condensing lens when condensing the laser light, and if the laser light reaches the condensing lens 3, the laser is applied to the joint surface S between the transparent member 1 and the absorbing member 2. Light can be condensed and the transparent member 1 and the absorbing member 2 can be reliably joined. And since the joining structure of this embodiment is what the transparent member 1 and the absorption member 2 were joined in this way, the transparent member 1 and the absorption member 2 will be joined reliably.

  Next, the joining method of the transparent member 1 and the absorbing member 2 will be described in more detail.

First, as shown in FIG. 2, the transparent member 1 is formed. Specifically, the transparent member 1 is formed by injection molding a material having translucency with respect to laser light.
Here, in the joining method of this embodiment, when the transparent member 1 is injection-molded, the condensing lens 3 is simultaneously formed on the upper surface 12 of the transparent member 1. For this reason, it is not necessary to separately perform a process for forming the condenser lens 3, and the transparent member 1 including the condenser lens 3 can be easily formed.
As described above, the shape of the condensing lens 3 is a parameter which can be obtained in advance (the wavelength of the laser light necessary for condensing the laser light on the joint surface S, the transparent member 1 and the condensing lens 3 It is set based on parameters such as refractive index.

  Subsequently, the absorbing member 2 is formed as shown in FIG. Specifically, the absorbing member 2 is formed by injection molding a material that absorbs laser light.

After forming the transparent member 1 and the absorbing member 2 in this way, the lower surface 11 of the transparent member 1 and the upper surface 12 of the absorbing member 2 are aligned. Then, as shown in FIG. 4, the laser light L is incident on the condenser lens 3 formed on the transparent member 1. As a result, the laser light L is condensed by the condenser lens 3 and is condensed on the joint surface S (interface) between the transparent member 1 and the absorbing member 2. Then, the laser light is absorbed by the absorbing member 2, so that the temperature at the joint surface S rises and the transparent member 1 and the absorbing member 2 are dissolved. For this reason, the transparent member 1 and the absorbing member 2 are joined by welding by stopping the irradiation of the laser beam L.
As the laser beam L, a semiconductor laser beam or a YAG laser beam can be used.

  According to such a joining method of the present embodiment, the condensing lens 3 that condenses the laser light L is formed on the transparent member 1. For this reason, when joining the transparent member 1 and the absorption member 2 by laser welding, it becomes unnecessary to arrange | position the condensing lens for condensing the laser beam L separately. Therefore, as long as the laser beam L reaches the condenser lens 3, the laser beam L is condensed on the bonding surface S between the transparent member 1 and the absorbing member 2, and the transparent member 1 and the absorbing member 2 are reliably bonded. It becomes possible.

In addition, since the joining structure and method of this embodiment used the condensing lens 3 as the spherical lens, it becomes possible to obtain a particularly good joining state when spot welding the transparent member 1 and the absorbing member 2.
However, the present invention is not limited to this. For example, as shown in FIG. 5, the condenser lens 3 is a cylindrical lens, or as shown in FIG. 6, the condenser lens 3 is a Fresnel lens. It is also possible. And when the condensing lens 3 is a cylindrical lens, it can carry out suitably when welding the transparent member 1 and the absorption member 2 over a long distance. When the condenser lens 3 is a Fresnel lens, the height of the condenser lens 3 itself can be suppressed.
Further, the condensing lens 3 may be another lens such as a toroidal lens.

  Moreover, in the joining structure and method of this embodiment, since the transparent member 1 and the absorbing member 2 were joined by welding, no adhesive was disposed between the transparent member 1 and the absorbing member 2, The thermoplastic adhesive is disposed between the transparent member 1 and the absorbing member 2, and the adhesive is softened by the heat generated when the laser light L is condensed, so that the transparent member 1 and the absorbing member 2 are It is also possible to bond.

(Recording head unit)
Next, the recording head unit of the present embodiment having the above-described joining structure will be described.
FIG. 7 is a perspective view showing a droplet discharge device including the recording head unit of the present embodiment.

The carriage 10 is supported by the guide member 20 and connected to the step motor 4 via the timing belt 30 so as to be able to reciprocate in parallel with the platen 5.
An ink jet recording head 6 is mounted on the lower surface of the carriage 10, and a printing unit 7 is detachably mounted on the upper surface.
In this embodiment, the recording head unit includes a carriage 10, an ink jet recording head 6, and a printing unit 7.

FIG. 8 is a cross-sectional view of the printing unit 7. The printing unit 7 includes a holder 110 mounted on the carriage 10 and an ink cartridge 200 accommodated in the holder 110, and an ink jet recording head 6 is provided on the lower surface of the holder 110 facing the recording paper 9. ing.
The recording head 6 is connected by a flexible cable 13 to a terminal plate 120 that is electrically connected to a terminal (not shown) on the carriage 10 connected to the flexible cable 8 of the printer main body so as to be able to contact and separate.

  The ink cartridge 200 is divided into two regions, an ink chamber 22 for storing ink as it is by a wall 210 and a foam chamber 24 filled with a foam material 23 made of a porous material. These two chambers communicate with each other through the through hole 25.

  A convex portion 26 is formed on the bottom surface of the foam chamber 24 to press the bottom surface of the foam material 23, and a through hole 27 that forms an ink supply path is formed therein, and a first filter plate 31 is provided at the upper end. In addition, an ink supply port 28 for receiving an ink supply needle 16 described later is provided at the lower end.

  The holder 110 has an upper end formed in a needle shape so as to pass through a seal 29 that seals the ink supply port 28 of the ink cartridge 200 and can be fitted into the packing 300, and a lower end is the recording head 6. An ink supply needle 16 having a through hole 15 connected to the ink flow path 14 communicating with the ink flow path 14 is implanted.

  Further, in the middle of such an ink supply path, between the lower end of the ink supply needle 16 and the through hole 14 communicating with the recording head 6 in the present embodiment, a second filter plate as shown in FIG. A filter chamber 33 having 32 is formed.

  The first filter plate 31 is a sintered nonwoven fabric 40, 41 formed by using a stainless steel wire having a wire diameter of several μm, that is, a thin steel wire about 1/10 of a steel wire used for a twill filter. And is attached to the mounting portion 26a of the convex portion 26 so as to cover the through hole 27 communicating with the ink supply port 28.

  Of these nonwoven fabrics 40 and 41, the first nonwoven fabric 40 located on the recording head 6 side has a small dynamic pressure loss when ink is supplied to the recording head 6, that is, the flow path resistance is low and the meniscus strength is possible. As high a filter as possible. Further, the second nonwoven fabric 41 laminated inside the nonwoven fabric 40 is not particularly required to have meniscus strength, but has a sufficient thickness that can reinforce the first nonwoven fabric 40, and has a flow resistance. It is formed as the smallest possible non-woven fabric.

The second filter plate 32 assembled so as to block the through hole 14 communicating with the recording head 6 is formed using a stainless steel wire having a wire diameter of several μm, like the first nonwoven fabric 40 on the ink cartridge 200 side. It is comprised as a sintered nonwoven fabric.
The second filter plate 32 is formed as a filter having a low dynamic pressure loss when ink is supplied to the recording head 6 and a meniscus strength as high as possible.

  Note that the second filter plate 32 is for reinforcement as the first filter plate 31 because one side is protected by the head frame 110 a of the recording head 6 and the other is surrounded by the ink supply needle 16. The non-woven fabric 41 is not required. However, if a reinforcing non-woven fabric is provided in the same manner as the first filter 31, the self-shape retaining property is increased and the assembly is facilitated.

  In this embodiment, when ink is consumed by the recording head 6 by printing, the ink absorbed in the foam material 23 of the cartridge 20 is sucked out by the recording head 6 and passes through the first filter plate 31. Then, the ink flows into the ink supply needle 16 through the through hole 27 and flows into the filter chamber 33 through the ink supply path 15. Since the cross-sectional area of the filter chamber 33 is substantially the same as that of the ink supply path 15, the ink flows into the recording head 6 via the through hole 14 without reducing the flow velocity.

FIG. 9 is an exploded perspective view of the recording head 6.
The pressure generation chamber forming substrate 50 includes two rows of pressure generation chambers 51 and 52, and one surface is sealed by a diaphragm 53. On the surface of the diaphragm 53, individually separated lower electrodes 54 and 55 are formed corresponding to the pressure generating chambers 51 and 52, and piezoelectric vibrators 56 and 57 are formed on the surfaces of these electrodes 54 and 55. Further, an upper electrode 58 is formed on the surface of the piezoelectric vibrators 56 and 57 so as to be crotched by the plurality of piezoelectric vibrators 56 and 57.

  The fixed substrate 59 has a function of fixing an actuator unit composed of the pressure generation chamber forming substrate 50 and the vibration plate 53 and a function as an ink supply port forming plate for receiving ink supply from the outside. 51, 52 are provided with communication holes 60, 61, 62, 63 communicating with both ends, and two ink introduction ports 67, 68 for independently supplying ink to each of two common ink chambers 65, 66 described later. It is provided and configured.

  The common ink chamber forming plate 69 forms the common ink chambers 65 and 66 for supplying the ink from the ink introduction ports 67 and 67 to the pressure generating chambers 51 and 52 through the communication holes 60 and 62, respectively. Thus, one surface is sealed with a fixed substrate 59 and the other surface is sealed with a nozzle plate 70. Two nozzle opening rows 71 and 72 are formed in the nozzle plate 70, and each pressure is generated via the communication holes 73 and 74 of the common ink chamber forming plate 69 and the communication holes 61 and 63 of the fixed substrate 59. It communicates with the chambers 51 and 52.

In this embodiment, the joining structure of the ink supply needle 16 and the holder 110 is the joining structure of the present invention. Specifically, as shown in the enlarged sectional view of FIG. 10, the ink supply needle 16 is configured as a transparent member, and the condensing lens 162 is provided on the flange portion 161 thereof. The holder 110 is configured as an absorbing member.
When such an ink supply needle 16 is joined to the holder 110, the laser light is incident on the condenser lens 162 formed on the flange portion 161 of the ink supply needle 16, so that the laser light is in contact with the ink supply needle 16. Since the light is condensed on the joint surface with the holder 110, the ink supply needle 16 and the holder 110 are securely joined.

  While the preferred embodiments of the joining structure and method and the recording head unit according to the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to the above-described embodiments. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  For example, in the above embodiment, the joining structure of the present invention is applied only to the joining structure between the ink supply needle 16 and the holder 110 of the recording head unit. However, the present invention is not limited to this, and can be applied to other joining structures that are joined using laser light.

  In addition, the condenser lens 3 of the above embodiment can have other functions. For example, the condenser lens 3 can have a function as an alignment mark and can be used for positioning the ink supply needle 16 and the holder 110.

It is the perspective view which showed typically the joining structure which is one Embodiment of this invention. It is explanatory drawing of the joining method which is one Embodiment of this invention. It is explanatory drawing of the joining method which is one Embodiment of this invention. It is explanatory drawing of the joining method which is one Embodiment of this invention. It is a modification of the junction structure which is one Embodiment of this invention. It is a modification of the junction structure which is one Embodiment of this invention. 1 is a perspective view illustrating a droplet discharge device including a recording head unit according to an embodiment of the present invention. It is sectional drawing of a printing unit. FIG. 3 is an exploded perspective view of a recording head. It is an expanded sectional view of an ink supply needle and a holder.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Transparent member, 2 ... Absorbing member, 3 ... Condensing lens (condensing part), S ... Joining surface (interface)

Claims (7)

A joining structure of a transparent member formed of a material having translucency with respect to laser light and an absorbing member formed of a material that absorbs the laser light,
The transparent member includes a condensing part that condenses the laser light on a joint surface between the transparent member and the absorbing member, and the laser light joins the transparent member and the absorbing member via the condensing part. A joining structure, wherein the transparent member and the absorbing member are welded by being focused on a surface. The joining structure according to claim 1, wherein the condensing part is a spherical lens. The junction structure according to claim 1, wherein the condensing part is a cylindrical lens. The junction structure according to claim 1, wherein the condensing part is a Fresnel lens. A recording head unit having the joint structure according to claim 1. A method of joining a transparent member formed of a material having a light-transmitting property to laser light and an absorbing member formed of a material that absorbs the laser light,
The transparent member includes a condensing part that condenses the laser light on a joint surface between the transparent member and the absorbing member, and the laser light joins the transparent member and the absorbing member via the condensing part. A joining method, wherein the transparent member and the absorbing member are welded by focusing on a surface. The joining method according to claim 6, wherein the condensing part is formed at the same time when the transparent member is formed by injection molding.

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