JP2011240512A - Fixing structure of sheet-like member to resin molding, and liquid ejection head using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a caulking structure which can facilitate the separation of a sheet-like member from a housing while suppressing the floating and deviation of the sheet-like member fixed to the housing, and to provide a liquid ejection head using the same.SOLUTION: The fixing structure fixes the sheet-like member 3 to a resin molding 9 with an expanded part 11 formed by heating and fusing an end of a caulking pin 7 which is projected from a surface of the resin molding 9 and passed through a fixing hole 8 provided in the sheet-like member 3. A recessed part 12 is formed around the caulking pin 7 on the surface of the resin molding 9. The edge of a projection image when the expanded part 11 is projected to the resin molding surface along the normal line direction of the resin molding surface is located outside the fixing hole 8 and inside the recessed part 12.

Description

  The present invention relates to a structure for fixing a sheet-like member to a resin member, and a liquid discharge head using the structure.

  As a method for fixing a sheet-like member to a resin molded product, a method using heat caulking is known. The fixing by heat caulking has a simple structure, and the price of an apparatus (caulking apparatus) necessary for realizing the structure is relatively low. Further, the time for fixing is as short as several seconds. Furthermore, there are many advantages such as little backlash after fixing and high fixing strength.

  7A to 7C are schematic cross-sectional views showing steps for realizing a conventional fixing structure by thermal caulking. As shown in FIG. 7 (a), a cylindrical caulking pin 7 integrally formed in advance with a thermoplastic resin member 9 is passed through a fixing hole 8 provided in advance in the sheet-like member 3. Next, as shown in FIG. 7 (b), the caulking pin 7 is heated until the horn 10 abuts against the sheet-like member 3 until the horn 10 is heated above the melting point of the thermoplastic resin that is the material of the member 9. Press on. At this time, the caulking pin 7 is instantaneously melted and deformed according to the shape of the heating and pressing horn 10 to form the enormous portion 11. The diameter of the enormous portion 11 is larger than the diameter of the fixing hole 8 of the sheet-like member 3, and the sheet-like member 3 is fixed to the member 9. Thereafter, as shown in FIG. 7C, the heating and pressure horn 10 is detached.

  When the sheet-like member is fixed to the resin molded product as described above, the sheet-like member may be pushed up by the molten lump formed on the root side of the caulking pin and float. Therefore, Patent Document 1 describes forming a recess around the caulking pin. According to Patent Document 1, since the molten mass accumulates (is absorbed) in the concave portion, it is possible to prevent the sheet-like member from being lifted and the parallelism from being pushed up by the molten mass being pushed up.

  Patent Document 2 describes that the enormous portion is formed away from the sheet-like member and the fixing hole of the sheet-like member is made larger than the diameter of the caulking pin. According to Patent Document 2, since the sheet-like member is not tightly fixed to the resin molded product, warpage and deformation of the sheet-like member are prevented.

  A liquid discharge head is known as an example of a resin molded product using a fixing structure by thermal caulking as described above. In particular, ink jet recording heads (hereinafter referred to as “recording heads”) are well known.

  A recording head generally includes a recording element substrate provided with an ejection port from which ink is ejected and an energy generating element that generates energy for ejecting ink from the ejection port. Further, the recording head is electrically connected to the printer main body side in order to receive an electric signal and electric power used for driving the energy generating element from the ink jet recording apparatus main body (hereinafter referred to as “printer main body”). A contact portion is provided. For example, a configuration is known in which a recording element substrate is disposed on the bottom surface of a housing of a recording head, and a contact portion including a plurality of contact pads is disposed on a side surface substantially perpendicular to the bottom surface.

  As described above, in order to electrically connect the contact portions arranged on different surfaces of the housing and the recording element substrate, a flexible electric wiring board, so-called flexible wiring board (hereinafter referred to as “electric wiring tape”). It is advantageous to use “. As a structure for fixing the electric wiring tape to the housing, a fixing structure by heat caulking is widely used.

Japanese Patent Laid-Open No. 06-195929 JP 09-109268 A

  However, the conventional techniques have the following problems. That is, in the conventional fixing structure including the structure disclosed in Patent Document 1, a sheet-like member is sandwiched between the enormous portion and the surface of the housing and is brought into close contact therewith. For this reason, it becomes difficult to separate the resin housing from the sheet-like member made of a different material. Specifically, when removing the sheet-like member from the housing, a part of the sheet-like member sandwiched between the enormous portion and the housing surface may be torn off and remain on the housing side. For this reason, even if it tried to collect | recover and recycle the resin molded product to which the sheet-like member was fixed, it was difficult to separate the resin molded product and the sheet-like member.

  On the other hand, in the fixing structure disclosed in Patent Document 2, the sheet-like member is not sandwiched between the enormous portion and the housing surface. Therefore, compared with the fixing structure disclosed in Patent Document 1, it is easier to separate the housing and the sheet-like member. However, since the sheet-like member is not in close contact with the housing surface, it is obvious that the sheet-like member is lifted from the housing surface or the positional accuracy of the sheet-like member is lowered. In such a state, for example, when electrical contacts are provided on the sheet-like member, the reliability of electrical connection is reduced.

  An object of the present invention is to facilitate the separation of a resin molded product and a sheet-shaped member while suppressing the floating of the sheet-shaped member fixed to the resin molded product and the decrease in positional accuracy.

  The structure for fixing the sheet-like member to the resin molded product of the present invention is formed by projecting from the surface of the resin-molded product and heating and melting the end of the caulking pin passed through the fixing hole provided in the sheet-like member. It is a fixing structure for fixing the sheet-like member to the resin molded product by the enormous part, and is a surface of the resin molded product, and a recess is formed around the caulking pin, along the normal direction of the surface of the resin molded product. The edge of the projected image when the enormous portion is projected onto the surface of the resin molded product is located outside the fixed hole and inside the recess.

  A liquid discharge head according to the present invention is electrically connected to a liquid discharge substrate provided with an energy generating element that generates energy for discharging liquid from a discharge port through which the liquid is discharged, and the liquid discharge port. A liquid discharge head provided on a resin-made housing with a flexible wiring board on which the contact pads are arranged, and protrudes from the surface of the housing, outside the region where the contact pads of the flexible wiring board are arranged The caulking pins respectively passed through the at least three fixing holes provided in the inner surface, the recesses formed around the caulking pins on the surface of the housing, and the ends of the caulking pins passed through the fixing holes are heated and melted. The edge of the projected image when projecting the enormous part on the surface of the enclosure along the normal direction of the enclosure surface is outside the fixed hole, One, located inside the recess.

  ADVANTAGE OF THE INVENTION According to this invention, a resin molded product and a sheet-like member can be easily separable, suppressing the float of a sheet-like member fixed to the resin molded product, and position shift.

1 is an external perspective view showing an example of a recording head to which the present invention is applied. It is a perspective view which shows one of the processes of fixing an electrical wiring tape to the ink tank (housing) shown in FIG. It is an expanded sectional view which shows typically another one of the process of fixing an electrical wiring tape to the ink tank (housing) shown in FIG. It is an expanded sectional view showing typically the state where a part of electric wiring tape was pushed in the crevice around caulking pin. It is a partial enlarged plan view showing another example of a recording head to which the present invention is applied. It is a typical sectional view explaining the force which acts on the electric wiring tape folded as shown in FIG. It is typical sectional drawing which shows the process for implement | achieving the conventional fixed structure.

(Embodiment 1)
Hereinafter, a liquid discharge head (hereinafter referred to as “recording head”) to which the present invention is applied will be described as a first embodiment of the present invention. FIG. 1 is an external perspective view of a recording head 1 according to this embodiment. As shown in FIG. 1, the recording head 1 includes a recording element substrate 2 as a liquid discharge substrate, a flexible wiring substrate (hereinafter referred to as “electric wiring tape 3”) as a sheet-like member, and a resin molded product. And the ink tank 4 (housing 9).

  Predetermined ink is injected into the ink tank 4. The injected ink is supplied to the recording element substrate 2 through an ink supply channel formed inside the ink tank 4. The ink supplied to the recording element substrate 2 is ejected from ejection ports provided in the substrate 2. In this embodiment, the recording head and the ink tank are integrated. However, the ink tank may be detachable from the recording head.

  The recording element substrate 2 is provided with an ink supply port and an electrothermal conversion element as an energy generating element that generates energy for ejecting ink. Further, electrode portions for receiving electric signals and electric power from the outside of the recording element substrate 2 (here, the electric wiring tape 3) are arranged along the edge of the recording element substrate 2.

  The electric wiring tape 3 has flexibility and forms an electric signal path for transmitting an electric signal for ejecting ink to the recording element substrate 2. The electrical wiring tape 3 is provided with a contact portion 5 composed of a plurality of contact pads for receiving electrical signals from the printer body. When the recording head 1 is mounted on the printer main body, the contact portion 5 comes into contact with a connector pin on the printer main body side to be electrically connected. The electric signal passes through the electric wiring portion connected to the contact portion 5 and is transmitted to the output terminal portion arranged on the edge of the electric wiring tape 3. The output terminal portion is electrically connected to the electrode portions arranged on the edge of the recording element substrate 2, and an electric signal is input to the recording element substrate 2. Then, ink is ejected from the recording element substrate 2 (ejection port) according to the input electric signal. Moreover, the sealing agent for protection is apply | coated to the output terminal part.

  Next, a method and structure for fixing the electric wiring tape 3 to the surface of the ink tank 4 (housing 9), which is a characteristic part of the present invention, will be specifically described.

  First, as shown in FIG. 2, one end of the electric wiring tape 3 is fixed to the second surface (bottom surface 9 a) of the housing 9 together with the recording element substrate 2 with an adhesive. Then, the middle of the electrical wiring tape 3 in the longitudinal direction is bent along the edge of the housing 9, and the other end is made to lie along the first surface (side surface 9b) of the housing 9 as shown in FIG. At this time, the four caulking pins 7 formed in advance on the side surface 9b of the housing 9 are passed through the fixing holes 8 formed in advance in the region outside the region where the contact portion 5 of the electric wiring tape 3 is disposed. Then, the electric wiring tape 3 is fixed to the housing 9 (side surface 9b of the housing 9) by heat caulking the end portion of each caulking pin 7 passed through each fixing hole 8. Hereinafter, the heat caulking will be described more specifically.

  As shown in FIG. 3 (a), a recess 12 is formed around each caulking pin 7 provided on the side surface 9b of the housing 9 over the entire circumference. As described above, the caulking pin 7 of the housing 9 is passed through each fixing hole 8 of the electrical wiring tape 3, and the electrical wiring tape 3 is brought into close contact with the side surface 9 b of the housing 9. Then, as shown in FIG. 3B, the end of each caulking pin 7 is pressurized from above while being heated and melted by the heating and pressurizing horn 10 (pressing from the tip side toward the root side). The caulking pin 7 is melted instantaneously and deformed in accordance with the shape of the heating and pressure horn 10 to form a huge portion 11. The pushing amount (falling amount) of the heating and pressing horn 10 at this time is set so that the electric wiring tape 3 is pushed into the recess 12 beyond the side surface 9b of the housing 9 as shown in FIG. Then, even if there is a variation in the dimensional tolerance of the housing 9, as shown in FIG. 3B, the bottom surface 11a of the enormous portion 11 is at the same height as the side surface 9b of the housing 9 or a slightly lower position. It is formed. By doing so, the electric wiring tape 3 is prevented from being lifted from the housing 9, and the electric wiring tape 3 is in close contact with the side surface 9 b of the housing 9. Therefore, the possibility that the position accuracy of the contact portion 5 (FIG. 1) is lowered is reduced, and the occurrence of poor electrical connection between the recording head 1 and the printer main body is suppressed.

  Further, as shown in FIG. 3C, the diameter b of the enormous portion 11 is smaller than the diameter a of the recess 12 formed around the caulking pin 7 and larger than the diameter of the fixing hole 8. Therefore, the edge of the projected image when the enormous portion 11 is projected onto the housing side surface 9 b along the normal direction of the housing side surface 9 b is located outside the fixing hole 8 and inside the recess 12. The enormous portion 11 can be formed by adjusting the shape of the heating and pressing horn 10 and the amount of melting of the caulking pin 7. With this configuration, the electric wiring tape 3 is prevented from being bitten between the bottom surface 11 a of the enormous portion 11 and the side surface 9 b of the housing 9. Therefore, when the electric wiring tape 3 is peeled from the housing 9, a part of the electric wiring tape 3 sandwiched between the bottom surface 11 a of the enormous portion 11 and the side surface 9 b of the housing 9 is not torn off. Therefore, when the used recording head 1 is collected and recycled, it is possible to easily separate the resin ink tank 4 (housing 9) from the electric wiring tape 3 made of a different material.

  As described above, according to the configuration of the present embodiment, a recording head that can easily separate the electrical wiring tape and the ink tank (housing) while maintaining the positional accuracy of the contact portion is realized.

In addition, the cross-sectional shape of the crimping pin 7 and the enormous part 11 is not limited to a circle, and for example, the crimping pin 7 may be a prismatic shape other than a cylindrical shape. Similarly, it is not limited to the round hole of the fixing hole 8, and may be a square hole.
(Embodiment 2)
Next, another example of the recording head to which the present invention is applied will be described as a second embodiment of the present invention. However, the basic configuration of the recording head according to the present embodiment is the same as that of the recording head according to the first embodiment. Therefore, here, differences from the recording head according to the first embodiment will be mainly described, and overlapping descriptions will be omitted as appropriate.

  FIG. 5 shows the electrical wiring tape 3 included in the recording head according to the present embodiment. As in the first embodiment, the electrical wiring tape 3 is bent so as to straddle the side surface 9b (first surface) and the bottom surface 9a (second surface) of the housing 9 on which the caulking pins 7 are projected. (See FIG. 1). The side surface 9b of the housing 9 is fixed to the housing 9 by heat caulking, and the bottom surface 9a is fixed together with the recording element substrate 2 by an adhesive.

  Here, the electric wiring tape 3 that is bent and fixed as described above tends to return to the straight state shown in FIG. In order to explain the force generated in the electrical wiring tape 3, FIG. As described above, since the electric wiring tape 3 tries to return to a straight state, a force is generated in the θ direction in the figure. Therefore, a force is generated in the electric wiring tape 3 around the caulking pin 7 in a direction (Y direction) parallel to the side surface 9b of the housing 9 to which the tape 3 is fixed. Incidentally, since the X direction is fixed by the enormous portion 11 of the caulking pin 7, the force in the same direction need not be considered.

  Therefore, in the present embodiment, as shown in FIG. 5, the slit 13 is continuously provided in the fixing hole 8 of the electric wiring tape 3, and the slit 13 is extended in the Y direction. That is, the slit 13 extends in parallel with the side surface 9 b toward the bottom surface 9 a of the housing 9. The width of the slit 13 is preferably smaller than the diameter of the caulking pin 7.

  By providing the slit 13 as described above, it becomes easier to remove the electric wiring tape 3 from the ink tank 4. For example, the electric wiring tape 3 is cut at a portion where the electric wiring tape 3 is bent, the cut end portion is held, and the electric wiring tape 3 is peeled off from the ink tank 4. Then, the slit 13 communicating with the fixing hole 8 is widened, and the enormous portion 11 of the caulking pin 7 is easily removed from the fixing hole 8, and the electric wiring tape 3 is detached from the ink tank 4.

  In addition, since a force in the Y direction is generated in the electric wiring tape 3, even if the slit 13 extending in the Y direction from the fixing hole 8 is provided, the positional deviation of the contact portion 5 is equivalent to the case without the slit 13. become. That is, even if the slit 13 is provided, the occurrence of poor electrical connection between the recording head 1 and the printer body does not increase.

  As described above, according to the configuration of the present embodiment, a recording head that can more easily separate the electrical wiring tape and the ink tank (housing) while maintaining the positional accuracy of the contact portion is realized.

DESCRIPTION OF SYMBOLS 1 Recording head 2 Recording element board | substrate 3 Electrical wiring tape 4 Ink tank 5 Contact part 7 Caulking pin 8 Fixing hole 9 Housing | casing 11 Enormous part 12 Recessed part

Claims (3)

The sheet-like member is fixed to the resin-molded product by a huge portion formed by heating and melting an end portion of a crimping pin protruding from the surface of the resin-molded product and passing through a fixing hole provided in the sheet-like member. A fixed structure,
On the surface of the resin molded product, a recess is formed around the caulking pin,
The edge of the projected image when the enormous portion is projected onto the surface of the resin molded product along the normal direction of the surface of the resin molded product is outside the fixed hole, and A structure for fixing a sheet-like member to a resin molded product, which is located inside. A liquid ejection substrate provided with an ejection port from which liquid is ejected and an energy generating element that generates energy for ejecting liquid from the ejection port, and a contact pad electrically connected to the liquid ejection substrate are disposed. The flexible wiring board is a liquid discharge head provided on a resin casing,
Caulking pins that protrude from the surface of the housing and are respectively passed through at least three fixing holes provided outside the region where the contact pads of the flexible wiring board are disposed;
A recess formed on the surface of the housing and around the caulking pin;
A huge portion formed by heating and melting the end portion of the caulking pin passed through the fixing hole,
The edge of the projected image when the enormous portion is projected onto the surface of the housing along the normal direction of the surface of the housing is located outside the fixing hole and inside the recess. A liquid discharge head. The flexible wiring board is bent so as to straddle a first surface of the casing from which the caulking pin is protruded and a second surface different from the first surface;
The liquid ejection head according to claim 2, wherein a slit extending in parallel with the first surface toward the second surface is provided in the fixed hole.

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