JP2007292274A - Manufacturing method of gasket and ink-jet coating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gasket manufacturing method which can form a coating with uniform thickness and excellent in adhesive strength and durability in a predetermined portion on a substrate, and an ink-jet coating device which can form the coating with the uniform thickness in a predetermined portion of object to be coated, and extend an activity life of head. <P>SOLUTION: When bonding sealant by coating an adhesive 4 in a predetermined portion of substrate 1, the predetermined portion of the substrate 1 is coated by discharging the adhesive 4 from nozzles of ink-jet head 2. Furthermore, in a process in which the sealant is bonded to the substrate moved in X direction by coating with a predetermined printing pattern, in such a way that the adhesive is discharged from a plurality of nozzles of the ink-jet head arranged along Y direction intersecting perpendicularly with the X direction; the ink-jet head includes a discharging width wider than a coating width of the adhesive which is parallel to the Y direction of the substrate, and changes a location in the Y direction of the ink-jet head every predetermined discharging frequency so that the discharging frequency of each nozzle can be equalized by enabling to move the ink-jet head along the Y direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a gasket manufacturing method and an ink jet coating apparatus, and more particularly, to a gasket used in a field related to automobiles or general industrial machinery and having a sealing material fixed to the gasket surface with a required pattern shape and thickness. The present invention relates to a manufacturing method and an ink jet coating apparatus suitably used for the manufacturing method.

  Conventionally, as shown in FIG. 18, a cylinder head gasket used for an automobile engine or the like is known. In FIG. 18, reference numeral 100 denotes a substrate, and a stainless steel plate such as SUS301, SUS301H, SUS304, or SUS430 is used. Reference numeral 101 denotes a sealing material, which is composed of a rubber layer.

In order to manufacture such a gasket, a substrate made of a metal thin plate is punched into a predetermined shape, and at the seal portion, the thin plate is pressed to form a bead 102 as shown in FIG. Thereafter, a rubber layer is printed at a predetermined position by a method such as screen printing, and then heated and vulcanized to obtain a sealing material 101, which is a product. At that time, in order to increase the adhesive force between the rubber layer and the substrate 100, an adhesive is applied to the substrate 100 in advance. Reference numeral 103 in FIG. 19 denotes an adhesive layer formed between the substrate 100 and the sealing material 101 by an adhesive.
JP 2002-257241 A: It is disclosed that a primer applied to a cylinder head gasket is applied by a dipping method or a printing method (Claim 6), and 0035 is a solid gasket of a primer and an adhesive It is described that the method using a pad is the most desirable method among the printing methods. JP 2004-148666 A: The head moves in the X and Y axis directions JP 2004-106474 A: Frequency distribution

  In the conventional gasket manufacturing method, as described in Patent Document 1, in order to apply an adhesive to the substrate surface, a method of immersing the entire substrate in an adhesive tank and then drying in the atmosphere is known. Is called dipping.

  In this method, there is a problem that the adhesive not only adheres to a portion which is not necessary, but also protrudes into a hole for a cooling water channel, for example.

  Moreover, when the substrate is pulled out from the adhesive tank and the excess adhesive is dropped, the adhesive liquid that could not be removed partially accumulates on the substrate surface, or the adhesive liquid flows after it remains, Since this was dried as it was, there was also a problem that the thickness of the adhesive became non-uniform.

  The thickness of the adhesive is preferably a constant thickness in order to maintain its performance, but in the conventional dipping method, the thickness of the adhesive is likely to be non-uniform in this way, When the film thickness deviates from the standard value, there is a problem that the adhesive strength is lowered.

  Further, the portion where the adhesive is accumulated becomes smeared, which is not preferable in appearance.

  Furthermore, the pad printing described in Patent Document 1 has a problem that it is difficult to control the film thickness.

  An object of the present invention is to provide a method for producing a gasket capable of forming a coating film having a uniform film thickness on a predetermined portion on a substrate, forming a coating film having excellent adhesive strength and excellent durability.

  Moreover, this invention makes it a subject to provide the inkjet coating device which can form the coating film of a uniform film thickness in the predetermined site | part of a coating target object, and can extend the service life of a head.

  Other problems of the present invention will become apparent from the following description.

  The above problems are solved by the following inventions.

(Claim 1)
In the method for manufacturing a gasket in which an adhesive is applied to a predetermined portion of a substrate to bond a sealing material, an adhesive solution is discharged from a nozzle of an inkjet head and applied to the predetermined portion of the substrate during the bonding. A method for manufacturing a gasket.

(Claim 2)
The method for producing a gasket according to claim 1, wherein the adhesive coating film is applied a plurality of times to form a predetermined thickness after drying.

(Claim 3)
Adhesive is discharged from a large number of nozzles of an ink jet head arranged along a Y direction perpendicular to the X direction to a predetermined portion of the substrate moved in the X direction, and is applied in a predetermined printing pattern. A method of manufacturing a gasket to be bonded, wherein the inkjet head has a discharge width wider than the coating width of the adhesive along the Y direction of the substrate, and the inkjet head can be moved along the Y direction. A method for manufacturing a gasket, characterized in that the position of the inkjet head in the Y direction is changed every predetermined number of discharges so that the discharge frequency of each nozzle is leveled.

(Claim 4)
Based on the printing pattern, the ejection frequency of each nozzle of the inkjet head is estimated, and the Y-direction position of the inkjet head is set every predetermined number of ejections so that the estimated ejection frequency of each nozzle is leveled. The method for manufacturing a gasket according to claim 3, wherein the gasket is changed.

(Claim 5)
An ink jet equipped with an ink jet head that applies a predetermined printing pattern by ejecting a coating liquid from a number of nozzles arranged along a Y direction orthogonal to the X direction with respect to a coating object moved in the X direction. A coating apparatus, wherein the inkjet head has a discharge width wider than a coating width of the adhesive along the Y direction of the substrate, and a moving unit that moves the inkjet head along the Y direction; An inkjet coating apparatus comprising: a control unit that changes the position of the inkjet head in the Y direction every predetermined number of ejections so that the ejection frequency of each nozzle is leveled.

(Claim 6)
An estimation unit configured to estimate a discharge frequency of each nozzle of the inkjet head based on the print pattern, and the control unit is configured to perform predetermined processing so that the discharge frequency of each nozzle estimated by the estimation unit is leveled 6. The ink jet coating apparatus according to claim 5, wherein the position of the ink jet head in the Y direction is controlled every number of ejections.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the gasket which can form the coating film of a uniform film thickness in the desired site | part on a board | substrate, and can form the coating film which is excellent in adhesive strength, and excellent in durability can be provided.

  Moreover, according to this invention, the inkjet coating apparatus which can form the coating film of a uniform film thickness in the predetermined site | part of a coating target object, and can extend the service life of a head can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic view showing an example of a method for manufacturing a cylinder head gasket (hereinafter referred to as CHG) used for an automobile engine or the like using an ink jet coating apparatus.

  The substrate 1 is punched into a required shape using a stainless steel plate similar to the conventional one and beaded as necessary. As the stainless steel plate, SUS301, SUS301H, SUS304, SUS430, or the like is used. Since the plate thickness is used for gaskets, a thickness of about 0.1 to 2 mm is generally used.

  The substrate 1 is placed on a work table (not shown). Here, the substrate 1 can be moved along the feed direction by moving at a predetermined speed along the feed direction indicated by an arrow in the drawing. It has become.

  An inkjet head 2 is disposed above the substrate 1 placed on the work table. The inkjet head 2 is supplied with an adhesive from a tank 3 in which the adhesive is stored. Application of the adhesive to the surface of the substrate 1 is performed by discharging the adhesive from the inkjet head 2 as a fine droplet-like adhesive 4 and landing it in the form of dots on the surface of the substrate 1.

  The structure of the ink jet head 2 is not particularly limited as long as the adhesive can be discharged in the form of fine droplets, but the pressure applied to the adhesive in the pressure generating chamber using an electromechanical transducer such as a piezoelectric element. It is preferable that the adhesive can be applied and the adhesive can be ejected from the nozzle in the form of fine droplets.

  FIG. 2 shows a state of the nozzle surface 21 of the inkjet head 2.

  A large number of, for example, 256 nozzles 22 are formed on the nozzle surface 21 of the inkjet head 2, and are arranged in parallel along the feed direction of the substrate 1. Although FIG. 2 shows the nozzles 22 arranged in one row, it is not particularly limited, and a large number of nozzles 22 may be arranged in parallel in a plurality of rows such as two rows.

  The hole diameter of the nozzle 22 can be 10 to 200 μm, preferably 50 μm. The shape of the nozzle 22 is also preferably a tapered shape that gradually tapers along the direction of ejection.

  Further, the number of inkjet heads 2 is not limited to one, and two or more inkjet heads 2 can be used side by side.

  The inkjet head 2 is arranged so that the nozzle surface 21 on which the nozzle 22 is formed is opposed to the surface of the substrate 1 placed on the work table, and scans and moves along a direction orthogonal to the feed direction of the work table. It can be made to.

  The adhesive 4 is discharged during the scanning movement of the ink jet head 2 and applied to the surface of the substrate 1 below. At this time, it is necessary to apply the adhesive 4 to the surface of the substrate 1 by appropriately controlling the position of the nozzle 22 that discharges the adhesive 4 in the inkjet head 2 and the discharge timing and the feeding speed of the substrate 1. The adhesive 4 can be easily applied in a desired pattern only to a certain region.

  FIG. 3 shows the gasket in the middle of applying the adhesive to the surface of the substrate 1 in this way. A region indicated by reference numeral 5 in the figure is a region where an adhesive is applied. By using an inkjet apparatus, an adhesive can be applied to the surface of the substrate 1 in a desired pattern, and there is no possibility that the adhesive protrudes into an unnecessary region.

  Then, CHG is created by adhering a sealing material (not shown) on the adhesive layer.

  The adhesive layer formed by the adhesive 4 ejected from the inkjet head 2 repeatedly ejects the adhesive 4 onto the surface of the substrate 1 (multiple application), so that the adhesive layer has a desired film thickness. It is also preferable to do so. The film thickness can be controlled in this way because the discharge amount from the inkjet head 2 can be controlled.

  The adhesive used in the present invention is preferably a silane, phenol or epoxy adhesive.

  As the silane-based adhesive, one obtained by dissolving a silane coupling agent in an organic solvent can be used, and it can be applied to the sealing material of the present invention. Specific examples of the silane-based adhesive include methacryloxypropyltrialkoxysilane and vinyltrialkoxysilane. As the methacryloxypropyltrialkoxysilane, methacryloxypropyltrimethoxysilane, methacryloxypropyltriethoxysilane, or the like is used. As the vinyltrialkoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, vinyltris (2-ethoxyethoxy) silane, or the like is used.

  As the phenolic adhesive, for example, a novolak or resol that is a phenolic resin can be used as a solution using a solvent by adding a curing agent such as isocyanate or hexamethylenetetramine, and a filler. Applicable.

  The epoxy adhesive can be used without particular limitation as long as it can be applied to the sealing material of the present invention, and specific examples include epoxy phenol, epoxy novolac, epoxy aromatic diamine, epoxy polyamine and the like. .

  These adhesives preferably have a solid content of 0.1 to 15% by weight, more preferably 1 to 10% by weight, and a viscosity of 1 to 300 cp.

  As the solvent used for the adhesive, general commercially available solvents such as aromatic, ketone, ether, and alcohol can be used. Examples of such a solvent include alcohol, toluene, MEK (methyl ethyl ketone), methyl isobutyl ketone, di-n-propyl ketone, cyclohexanone, phorone, and isophorone.

  In the present invention, it is optional to apply an appropriate primer before applying the adhesive. Such primers include zinc phosphate coating, iron phosphate coating, coated chromate coating, vanadium, zirconium, titanium, molybdenum, tungsten, manganese, zinc and cerium compound or oxide inorganic coating, silane, phenol, epoxy, An organic film such as urethane is applied and heat-treated to form a primer layer having a thickness of about 0.01 to 10 μm.

  In the present invention, the sealing material is a general rubber material such as nitrile rubber, hydrogenated nitrile rubber, ethylene-propyne rubber, styrene-butadiene rubber, natural rubber, fluorine rubber, acrylic rubber, chloroprene rubber, butyl rubber, silicone rubber, or TPE. An elastic body such as an elastomer or a resin mixture thereof.

  In the present invention, after forming an adhesive and a rubber layer, an anti-tack agent may be applied as a protective film for preventing sticking of rubber, preventing wear, reducing deterioration, and the like.

  Adhesive components such as graphite, PTFE, molybdenum disulfide, carbon black, wax, etc. as adhesion inhibitors, and cellulose resin, acrylic resin, polybutadiene resin, epoxy resin, phenol resin, silicone resin, urethane resin as binder And a non-adhesive layer having a thickness of about 1 to 10 μm is formed by applying, heat treating, etc. a dispersion liquid dispersed in an organic solvent and water.

  The inkjet head 2 in the inkjet coating apparatus described above is arranged so that a large number of nozzles 22 are parallel along the feeding direction of the substrate 1, and the nozzle 22 discharges the adhesive 4 while the feeding direction of the substrate 1. By performing reciprocal scanning along the orthogonal direction, the feeding operation of the substrate 1 and the scanning movement of the inkjet head 2 cooperate to apply and print the adhesive 4 on the surface of the substrate 1 with a predetermined printing pattern. However, the configuration of the ink jet coating apparatus used in the gasket manufacturing method according to the present invention is not limited to this, and only the substrate 1 is stopped with the ink jet head 2 stopped as shown in FIG. May be sent in one direction.

  In this case, the many nozzles 22 of the inkjet head 2 are arranged so as to be parallel along the direction orthogonal to the feeding direction of the substrate 1, and the discharge width (length of the nozzle row) is the surface of the substrate 10. The width of the adhesive 4 may be the same as or slightly larger than the width at the time of applying and printing.

  By the way, when the inkjet head 2 is used for a long time, the film thickness of the adhesive layer formed by the adhesive 4 discharged from the inkjet head 2 tends to increase. FIG. 7 is a graph showing the relationship between the number of ejections and the film thickness ratio. When the discharge conditions are not adjusted, the film thickness ratio increases as the number of discharges increases.

  The cause of such an increase in film thickness is thought to be due to wear and tear of the nozzle 22. The graph of FIG. 8 represents the relationship between the number of discharges and the discharge flow rate ratio. In general, an ink jet head ejects fluid at a high speed of several kHz to several tens of kHz. Therefore, as the number of ejections increases, the nozzle 22 wears due to friction when the fluid passes through the nozzle 22, and the nozzle diameter changes greatly. come. The change in the nozzle diameter increases the discharge flow rate. As a result, the film thickness ratio increases.

  Such a change in the discharge flow rate can be corrected to some extent as shown in FIG. 7 by changing (adjusting) the discharge conditions such as the discharge voltage and discharge frequency of the inkjet head 2.

  However, when the gasket is manufactured by applying and printing the adhesive 4 on the surface of the substrate 1 as shown in FIG. That is, since the inkjet head 2 shown in FIG. 6 is stopped and the adhesive 4 is discharged from the nozzles 22, the discharge frequency of only the specific nozzles 22 is increased depending on the print pattern, and compared with the other nozzles 22. It will wear out first. This is because the discharge conditions such as the discharge voltage and the discharge frequency are commonly applied to all the nozzles 22 and therefore cannot cope with a change in the discharge flow rate due to wear and wear of the specific nozzles 22.

  FIG. 9 is a graph showing a frequency distribution representing the ejection frequency of the nozzles 22 of the inkjet head 2 in the inkjet coating apparatus shown in FIG. It can be seen that by repeating the discharge a plurality of times, it is clearly divided into a peak portion having a high discharge frequency and a valley portion having a low discharge frequency.

  As described above, when the discharge frequency of a specific nozzle 22 is increased, the specific nozzle 22 is first worn and worn, and the nozzle diameter increases, so that the film thickness of the adhesive layer formed on the substrate 1 varies. Result. If the film thickness of the adhesive layer varies, it is not preferable because it leads to a decrease in performance and quality of the manufactured gasket. In addition, since the life of the inkjet head 2 is determined by the nozzle portion that wears and wears first, the head needs to be replaced at an early stage. Since the inkjet head is expensive, the consumption cost of the head cannot be ignored.

  Accordingly, a manufacturing method and an inkjet coating apparatus that are preferable when the adhesive 4 is discharged and applied and printed while the substrate 1 is fed in one direction while the inkjet head 2 is stopped will be described below.

  FIG. 10 is a plan view illustrating an example of an inkjet coating apparatus, and FIG. 11 is a block diagram illustrating a schematic configuration of the inkjet coating apparatus.

  In FIG. 10, 10 is a work table and 20 is an inkjet head.

  The work table 10 is provided so as to be movable at a predetermined speed along the right direction (X direction) in FIG. 10 by driving the X-direction feed motor 40 controlled by the CPU 30 shown in FIG. The substrate 1 to be placed can be moved along the X direction.

  An ink jet head 20 is disposed above the work table 10. The inkjet head 20 is supplied with an adhesive that is a coating solution stored in a tank not shown here.

  The application of the adhesive to the surface of the substrate 1 is performed by the CPU 30 shown in FIG. 11 by calling a print pattern stored in the print pattern data memory 50 and driving the head driver 60 based on the print pattern. In the process in which the substrate 1 on the substrate 10 is sent in the X direction, it is discharged as a fine droplet-like adhesive from a predetermined nozzle of the inkjet head 20 at a predetermined timing, and is formed into dots on the surface of the substrate 1 This is done by landing. At this time, it is necessary to apply the adhesive to the surface of the substrate 1 by the CPU 30 appropriately controlling the position of the nozzle for discharging the adhesive in the inkjet head 20, the timing of the discharge, and the feeding speed of the substrate 1. An adhesive is applied and printed on a certain area.

  The structure of the inkjet head 20 is not particularly limited as long as the adhesive can be discharged in the form of fine droplets. However, the structure of the inkjet head 20 can be applied to the adhesive in the pressure generating chamber using an electromechanical transducer such as a piezo element. It is preferable to apply pressure so that the adhesive can be ejected from the nozzle in the form of fine droplets.

  FIG. 12 is a view of the inkjet head 20 as viewed from the nozzle surface side.

  The inkjet head 20 includes a plurality of head units 20A, 20B, and 20C. In each of the head units 20A, 20B, and 20C, a large number (for example, 256) of nozzles 201 are parallel to each other along the Y direction orthogonal to the X direction that is the feed direction of the work table 10. It is arranged. Here, three head units 20A, 20B, and 20C are included, but the number may be appropriately increased or decreased according to the required length of the inkjet head 20 along the Y direction.

  The hole diameter of the nozzle 201 can be 10 to 200 μm, preferably 50 μm. The shape of the nozzle 201 is also preferably a tapered shape that gradually tapers along the ejection direction.

  These head units 20A, 20B, and 20C are arranged in a staggered manner along the Y direction so that the nozzle pitch between adjacent head units is the same as the nozzle pitch of each head unit 20A, 20B, and 20C. Yes. Accordingly, the inkjet head 20 having a long discharge width W1 having nozzles 201 that is three times (768) the number of nozzles of one head unit is configured. The discharge width is a width in which an adhesive can be discharged from the nozzle 201 for printing and is a distance between two nozzles 201 and 201 located at both ends of the inkjet head 20 in the Y direction.

  Here, the ejection width W1 of the inkjet head 20 is formed to be larger than the coating width W2 (FIG. 10) along the Y direction when the adhesive is applied and printed onto the surface of the substrate 1.

  Further, as shown in FIG. 10, the inkjet head 20 is provided so as to be movable in parallel with the surface of the substrate 1 in both directions along the Y direction. The movement of the inkjet head 20 in the Y direction is preferably divided into a plurality of movement strokes and can be moved stepwise.

  Reference numeral 70 in FIG. 11 is a Y-direction moving mechanism that moves the inkjet head 20 in the Y direction in this way, and is driven and controlled by the CPU 30. The specific configuration of the Y-direction moving mechanism 70 is not particularly limited, and for example, a single axis robot can be used.

  Thus, since the inkjet head 20 has the discharge width W1 larger than the coating width W2 of the board | substrate 1, when it uses it in the state which stopped the position movement of the Y direction of the inkjet head 20, its discharge width W1. Only the nozzle 201 in a part of the region is used. As an example, when the coating width W2 on the substrate 1 is 150 mm at the maximum and the discharge width W1 of the inkjet head 20 is 210 mm, which is about 1.5 times that, the nozzle 201 in the region of about 60 mm pauses. Will be. However, if the inkjet head 20 is moved by a predetermined amount in the Y direction within the range of the movement stroke, the nozzle 201 that has been inactive until then can be involved in the coating printing, while on the other hand, in the coating printing until then. The nozzle 201 that was involved can be deactivated.

  In this ink jet coating apparatus, when the gasket is manufactured using such a function of the ink jet head 20, the discharge frequency of the adhesive is prevented from concentrating on the specific nozzle 201, and the nozzle in the entire ink jet head 20 is prevented. The discharge frequency 201 is leveled.

  FIG. 13 shows an algorithm at the time of manufacturing a gasket by this ink jet coating apparatus.

  First, the CPU 30 calls and inputs the print pattern data stored in the print pattern data memory 50 (S1). This print pattern data is obtained by converting a print pattern representing an adhesive application region 5 on the surface of the substrate 1 as shown in the lower part of FIG.

  If the print pattern is known, the position (coordinates) of the nozzle 201 that discharges the adhesive and the discharge frequency (frequency) can be estimated based on the print pattern data.

  Therefore, the CPU 30 next estimates the ejection frequency of each nozzle 201 from the print pattern data and creates a frequency distribution of the nozzles 201 of the inkjet head 20 used for ejection (S2).

  The graph of the frequency distribution in the case of the print pattern shown in the lower part of FIG. 14 is shown in the upper part. As shown here, the application region 5 is generated over almost the entire length along the X direction in the vicinity of both left and right ends of the substrate 1, but in the vicinity of the center, the application is performed due to the presence of the annular portion 1a where the adhesive is not applied and printed. The region 5 is generated in pieces along the X direction. For this reason, the frequency distribution of the nozzle 201 is extremely high at coordinates near the left and right ends of the substrate 1 and extremely low at coordinates near the center.

  When CHG is created using a print pattern having such a frequency distribution, the frequency increases as the number of substrates 1 increases or as the number of times of application to a single substrate 1 increases a plurality of times. The wear and tear of only the nozzle 201 becomes severe.

  Therefore, after creating such a frequency distribution, the CPU 30 determines an optimal position control pattern along the Y direction of the inkjet head 20 that equalizes the frequency distribution (S3). This position control pattern is determined based on the frequency distribution, the ejection width W1 of the inkjet head 20, the number of manufactured sheets, and the like.

  FIG. 15 shows a frequency distribution in the case of applying 10 times to one substrate 1. By controlling the position along the Y direction of the inkjet head 20 and changing the nozzle area to be used, the frequency distribution B in the case of applying 10 times without performing the position control of the inkjet head 20 in the Y direction, the frequency The distribution is leveled as A. C indicates a frequency distribution when the ink jet head 20 is applied once without controlling the position in the Y direction.

  Thereafter, the substrate 1 is placed on the work table 10 to start manufacturing CHG (S4). At the time of manufacturing, the wear frequency is not increased by increasing the discharge frequency of only the specific nozzle 201, the life of the inkjet head 20 can be extended, and the replacement frequency of the inkjet head 20 can be reduced. become.

  Further, since all the nozzles 201 of the inkjet head 20 are used almost evenly, the problem that the nozzle diameter of the specific nozzle 201 changes due to wear and the discharge amount of the adhesive partially increases can be avoided. Even after a long period of use, it becomes possible to maintain a uniform coating film thickness, which is a characteristic of inkjet coating, and to suppress variations in performance and quality.

  Although the algorithm shown in FIG. 13 shows the case of one product pattern, in actuality, since the manufacture of gaskets usually involves combining two or more substrates, optimization with a plurality of printing patterns is necessary. There is. Therefore, it is preferable that the processing of the print pattern data with a plurality of print patterns is performed in advance before the start of production, and the entire production plan is optimized.

  In the example shown in FIG. 15, the frequency distribution is leveled by dividing the discharge width W1 of the inkjet head 20 into 10 parts, and performing the position control in 6 stages with the 6 parts of the movement width being the movement stroke in the Y direction. However, if the number of divisions is increased to perform more precise position control, the frequency distribution is further leveled. For example, when the number of nozzles is 768 nozzles, the discharge width W1 can be divided into 768 corresponding to the number of nozzles, and the position can be controlled for each nozzle pitch to achieve further optimization.

  The movement of the inkjet head 20 along the Y direction is not limited to the one that is automated by the control of the CPU 30 as described above, and can also be performed manually.

  For example, as in the example of CHG shown in FIG. 16, in the case where the coating region 5 on the substrate 1 is formed by a simple printing pattern, the inkjet head 20 is simply shifted along the Y direction with a constant width. As shown in the graph of the frequency distribution shown in Fig. 5, it is possible to easily suppress the overlapping of frequency peaks. In this case, since the inkjet head 20 may be simply shifted along the Y direction with a constant width, the number of substrates 1 and the number of coatings, etc., are predetermined as long as there is a simple moving mechanism that can move the inkjet head 20 with a constant width. The frequency distribution can be leveled by manually moving the inkjet head 20 for each number of ejections.

  Even when the position control along the Y direction of the inkjet head 20 is performed as described above, the wear and wear of the nozzle 201 progresses with use for a long time, and the discharge amount increases accordingly. As shown in the graph, the film thickness ratio increases. In this case, in order to correct the increase, it is preferable to appropriately adjust the discharge conditions such as the discharge voltage and discharge frequency of the inkjet head 20.

  In the above description, the method for manufacturing CHG is taken as an example of the method for manufacturing the gasket, but other gaskets may be used.

  Hereinafter, the present invention will be described in more detail with reference to examples.

Example 1 (inkjet method)
The ink jet apparatus used was an apparatus provided with three heads with a coating width of 70 mm and 256 holes.

  The following adhesive was applied to a gasket made of SUS304 having a width of 20 mm (shown in FIG. 5) using the inkjet device.

  The applied voltage of the piezoelectric element of the ink jet head was 90 v, the frequency was 40 μm / pulse, and the work table feed speed was 100 mm / sec.

<Adhesive composition>
The adhesive composition is as follows.

Cresol-modified novolak type phenolic resin (Dainippon Ink Chemical Co., Ltd. product KA-1053L solid content 40%) 400 (100) parts by weight Resol type phenolic resin (Dainippon Ink Chemical Industry product AF-2639 solid content 40%) 211 (133) Part by weight Unvulcanized NBR (JSR type N-237) 99 parts by weight Methyl ethyl ketone 2965 parts by weight Toluene 1965 parts by weight Isophorone 1000 parts by weight

Comparative Example 1 (immersion method)
The gasket used in Example 1 was dipped in a dipping tank containing the adhesive used in Example 1 and dipped.

(Evaluation test)
1. Film thickness variation test by adhesive The thickness (nm) of the coating film after coating and drying was measured with a film thickness meter (spectrometer), and the results are shown in FIG.

  It can be seen that the variation of the method of Example 1 is smaller than that of the dipping method of Comparative Example 1 even within the same standard value range. Therefore, it can be seen that the method of the present invention forms a uniform coating film with little variation.

2. Adhesive strength Adhesive conditions were set to 150 ° C. × 72 Hr, and tensile shear strength (MPa) was measured according to JIS K6850 to examine the adhesive strength. The result is shown in FIG.

  In Example 1 (inkjet method), it can be seen that the tensile shear strength is improved as compared with Comparative Example 1 (immersion method).

3. Durability Test A 100-cycle durability test was conducted with steam (140 ° C. × 20 min) and water temperature (25 ° C. × 20 min).

  As a result, the ink-jet application of Example 1 was superior in durability to the dipping method of Comparative Example 1 although the coating was peeled off.

Schematic showing an example of a method for manufacturing a cylinder head gasket The figure which shows the mode of the nozzle surface of the inkjet head The figure which shows the gasket in the middle of applying the adhesive to the surface of the substrate The figure which shows the result of having measured the thickness of the coating film after coating and drying with a film thickness meter (spectrometer) (left is immersion method, right is inkjet method) The figure which shows the result of measuring the tensile shear strength after adhesion (left is immersion method, right is inkjet method) The top view which shows the inkjet coating apparatus which concerns on another aspect. Graph showing the relationship between the number of ejections of the inkjet head and the film thickness ratio Graph showing the relationship between the number of ejections and the ejection volume of an inkjet head Graph showing frequency distribution of inkjet head The top view which shows the inkjet coating apparatus which concerns on another aspect. The block diagram which shows schematic structure of the inkjet coating apparatus shown in FIG. The figure which looked at the inkjet head of the inkjet coating apparatus shown in FIG. 10 from the nozzle surface side Algorithm for manufacturing gaskets in the inkjet coating apparatus shown in FIG. Figure showing the gasket print pattern and frequency distribution Graph showing frequency distribution of inkjet head without position control and inkjet head with position control Plan view showing another example of gasket printing pattern The graph showing the frequency distribution in the gasket shown in FIG. Figure showing a conventional example Figure showing a conventional example

Explanation of symbols

1: Substrate 1a: Annular part 2: Inkjet head 21: Nozzle surface 22: Nozzle 3: Tank 4: Adhesive 5: Area where adhesive is applied 10: Worktable 20: Inkjet head 20A, 20B, 20C: Head unit 201: Nozzle 30: CPU
40: X direction feed motor 50: Print pattern data memory 60: Head driver 70: Y direction moving mechanism

Claims (6)

In the method of manufacturing a gasket for applying a bonding agent to a predetermined part of a substrate and bonding a sealing material,
A method for manufacturing a gasket, characterized in that an adhesive is discharged from a nozzle of an inkjet head and applied to a predetermined portion of the substrate during the bonding.   The method for producing a gasket according to claim 1, wherein the adhesive coating film is applied a plurality of times to form a predetermined thickness after drying. Adhesive is discharged from a large number of nozzles of an ink jet head arranged along a Y direction perpendicular to the X direction to a predetermined portion of the substrate moved in the X direction, and is applied in a predetermined printing pattern. A method of manufacturing a gasket to be bonded,
The inkjet head has a discharge width wider than the width of the adhesive along the Y direction of the substrate, and the inkjet head is movable along the Y direction.
A method for manufacturing a gasket, characterized in that the position of the inkjet head in the Y direction is changed every predetermined number of discharges so that the discharge frequency of each nozzle is leveled.   Based on the printing pattern, the ejection frequency of each nozzle of the inkjet head is estimated, and the Y-direction position of the inkjet head is set every predetermined number of ejections so that the estimated ejection frequency of each nozzle is leveled. The method for manufacturing a gasket according to claim 3, wherein the gasket is changed. An ink jet equipped with an ink jet head that applies a predetermined printing pattern by ejecting a coating liquid from a number of nozzles arranged along a Y direction orthogonal to the X direction with respect to a coating object moved in the X direction. A coating device,
The inkjet head has a discharge width that is wider than the coating width of the adhesive along the Y direction of the substrate,
Moving means for moving the inkjet head along the Y direction;
An inkjet coating apparatus comprising: a control unit that changes the position of the inkjet head in the Y direction every predetermined number of ejections so that the ejection frequency of each nozzle is leveled. Having estimation means for estimating the ejection frequency of each nozzle of the inkjet head based on the printing pattern;
The said control means controls the position of the said Y direction of the said inkjet head for every predetermined discharge frequency so that the discharge frequency of each nozzle estimated by the said estimation means is equalized. The inkjet coating apparatus as described.

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