GB2024079A

GB2024079A - Panel assembling method

Info

Publication number: GB2024079A
Application number: GB7918945A
Authority: GB
Original assignee: Nissan Motor Co Ltd
Current assignee: Nissan Motor Co Ltd
Priority date: 1978-06-08
Filing date: 1979-05-31
Publication date: 1980-01-09
Also published as: FR2428168A1; GB2024079B; DE2923314A1

Abstract

The method comprises spraying 28 a thermosetting adhesive to coat the same on and about the connection area of a first panel which is to be fixed to the connection area of a second panel, bringing together the connection areas of the first and second panels to form a vehicle component, installing the vehicle component to a vehicle body, and heating the vehicle body to set the thermosetting adhesive. The thermosetting adhesive is of a type which forms a protective coat on its surface when exposed to air, radiation or water. <IMAGE>

Description

SPECIFICATION Panel assembling method This invention relates to a method of assembling panels to form a vehicle component such as a vehicle door, trunk lid, hood or the like with a great efficiency and without the need for any rust proofing process.

In order to assemble panels to form a vehicle component such as a vehicle door, trunk lid, hood or the like in an efficient manner, a panel assembling method using a structural adhesive has been proposed, which includes (1) coating a thermosetting structural adhesive entirely or partially on the connection area of one of inner and outer panels to be mated with the connection area of the other panel, (2) coating zinc-enriched primer over the inside of the outer panel, (3) temporarily assembling the inner and outer panels such as by seaming, (4) installing the vehicle component to a vehicle body, (5) undercoating the vehicle body such as by electrodeposition coating, (6) heating the vehicle body to dry the coating and simultaneously to set the structural adhesive so as to provide a sufficient strength to the vehicle component, and (7) final-coating the vehicle body.However, such a conventional method has numerous disadvantages. First, it is required to separately coat the structural adhesive and the primer, with resulting poor efficiency. Second, the strength of connection of the inner and outer panels is low since it is determined by the strength of separation of the primer from the panel. Third, it is very difficult to coat the structural adhesive on the connection area of the outer panel so as to produce a constant thickness. This will cause irregular contraction of the structural adhesive when it is heated, resulting in deformation of the assembly.

Fourth, since surplus structural adhesive will be squeezed out upon seaming of the inner and outer panels, an additional process is required to wipe off this squeezed-out structural adhesive. This is true particularly when the structural adhesive is coated in bead form on the entire peripheral area of the outer panel.

According to the present invention, there is provided a method of assembling panels, which comprises; (a) spraying a rust-proof thermosetting adhesive to coat the same on and about the connection area of a first panel which is to be fixed to the connection area of a second panel; (b) bringing together the connection areas of the first and second panels to form a vehicle component; (c) installing the vehicle component to a vehicle body; and (d) heating the vehicle body to set the thermosetting adhesive.

The present invention thus seeks to provide an improved panel assembling method which can assemble panels to form a component and can install the component to a vehicle body with higher efficiency. Furthermore in one aspect of the present invention, there is to provide an improved panel assembling method which can eliminate the need for any rust proofing process, with resulting higher efficiency.

The present invention also includes an improved thermosetting adhesive which can be coated onto a panel so as to produce a uniform thickness.

Another aspect of the present invention is to provide an improved thermosetting adhesive which will form a protective coat to prevent the adhesive from scattering and being washed away even though hot water is sprayed against the adhesive coated on a panel.

Following is a description by way of example only and with reference to the accompanying drawings of methods of carrying the invention into effect.

In the drawings: Figure 1 is a schematic diagram showing a vehicle component assembly line; Figure 2 is a plan view showing the area on which a thermosetting structural adhesive is coated; and Figure 3 is a perspective view showing an automatic adhesive spraying apparatus.

Referring now to Fig. 1, there is illustrated in diagrammatic form part of a panel assembling line including a number of processing stations, on which inner and outer panels are assembled to form a vehicle component such as, for example, a vehicle hood. An outer panel is put into the line automatically or by an operator from an outer panel input station 1, and is moved to an adhesive coating station 2 including an automatic adhesive spraying apparatus 10 to be described later in more detail for coating a thermosetting structural adhesive on the area of the outer panel indicated by the hatched area in Fig. 2; that is, on the connection area A of the outer panel to be seamed with an inner panel and its vicinities B.

Further, an inner panel is put into the line automatically or by an operator from an inner panel input line 3 and is moved to a welding station 4 where a bracket such as a hood hinge or the like is welded to it. The inner and outer panels are mated with each other in a marriage station 5 and then the mated panels are seamed as a unit in a seaming station 6.

Subsequently, the seamed panels are fed out from the line such as by a conveyer.

Referring to Fig. 3, the automatic adhesive spraying apparatus 10 is shown as comprising four sprayers generally designated as 20. The sprayers 20 are mounted to respective mounting frames 21 arranged to define four sides of a rectangular frame. Each of the sprayers 20 comprises a drive cylinder 22 fixed to a mounting frame 21. The drive cylinder 22 has a piston with its opposite ends connected by a chain 23 guided by pulleys 24 and 25.

Secured to the chain 23 is a slider 26 slidably supported on a guide rod 27 fixed to the mounting frame 21. The slider 26 carries a spray gun 28, which is connected, by means of a hose 29, through a pump 30 to a tank 31 having a supply of a thermosetting structural adhesive.

When an outer panel is carried on shuttle bars 32 to the automatic adhesive spraying apparatus 10, a lift cylinder 33 is actuated to lift an underframe 34 having locator members 35 secured thereto so as to position the outer panel. Then, the structural adhesive is sprayed from the spray guns 28 on and about the connection area of the outer panel to be seamed with the inner panel, while the cylinders 22 are actuated to move the spray guns 28. Although the spray guns 28 can move only in a plane in the illustrated embodiment, this is satisfactory since the outer panel of a vehicle component such as a vehicle hood, door or the like is not greatly curved.

The thermosetting structural adhesive used in the present invention should (1) be rust resistant, (2) should have a low coefficient of contraction upon setting, (3) should be coatable using a sprayer, and (4) should form a protective coat on its surface so as not to cling to other substances and so as not to be washed away by hot water sprayed thereagainst during washing.

The following Examples specifically define the advantageous thermosetting adhesives used in the present invention which will satisfy the requirements enumerated above. The parts and percentages are by weight unless otherwise indicated.

Example 1 A mixture of 110 parts of bisphenol A diglycidyl ether (Epycoat 828, tradename for Shell Chemical Co.'s product with an epoxy equivalent of 1 90 and a viscosity of 12,000 cps/25 C) and 100 parts of dicyandiamide was crushed in a roller mill to prepare an epoxy resin paste with dicyandiamide dispersed uniformly therein.An adhesive was prepared by mixing 42 parts of the epoxy resin paste, 100 parts of Epycoat 828, 100 parts of 1 ,6-hexane diol diglycidyl ether (with an epoxy equivalvent of 165 and a viscosity of 25 cps/25 C), 100 parts of modified cashew-nut shell oil (Cashew 2520, tradename for Cashew Co.'s product with a viscoity of 82,000 cps/25 C), 2 parts of mineral spirit solution of cobalt naphthenate with cobalt content of 8% (hereinafter referred merely to as cobalt naphthenate solution), 3 parts of mineral spirit solution of lead naphthenate with lead content of 15% (hereinafter referred merely to as lead naphthenate solution), 100 parts of inorganic filler (calcium carbonate fine powder made by Shiraishi Calcium Co.), and 10 parts of silicic anhydride.

The adhesive was found to have a viscosity of 5,200 cps/20 C (measured with e B type viscometer in accordance with JIS K6838) and to be coatable uniformly on a steal plate at 20"C using an airless sprayer (made by Nippon Gray Co.: pressure ratio: 28:1, gun pressure: 1 50 Kg/cm2, nozzle chip: 163-711). A steel plate with the adhesive coated thereon to produce a thickness of about 0.3 mm was placed in the air at room temperature for 24 hours and an non-sticky coat formed on the surface of the coated adhesive. Hot water (70"C) was sprayed for 30 minutes against the coat using an airless spray gun with its nozzle removed (hydraulic pressure: 5 kg/cm2) placed 100 cm away from the coat of the adhesive, and the coat was not scattered or washed away.This showed that the coat could protect the coated adhesive from hot water sprayed thereon.

A steel panel with this adhesive coated thereon to a thickness of about 0.3 mm was contacted with another steel panel just after coating with the adhesive, and then the panels were heated for 30 minutes. The tensile shear strength of the adhesive was 1 70 kg/cm2 (measured in accordance with JIS K6850) and T-peal strength thereof was 6.8 kg/25 mm width (measured in accordance with JIS K6854).

Example 2 An epoxy resin paste was prepared by mixing 100 parts of Epycoat 828 and 20 parts of dicyandiamide denatured setting agent (D610, tradename for Asahi Chemical Industry Co.'s product) and crushing the mixture in a roller mill to uniformly disperse the dicyandiamide. An adhesive was prepared by mixing 1 20 parts of the epoxy resin paste, 100 parts of 1 ,6-hexane diol diglycidyl ether, 100 parts of linseed oil denatured medium oil alkyd resin (Beckosol Solid No. 34, tradename for Dai-Nippon Ink s Chemicals, Inc.'s product), and 2 parts of cobalt naphthenate solution.

The adhesive was found to have a viscosity of 7,500 cps/20 C and to be coatable uniformly on a steel panel using a sprayer. A steel plate with the adhesive coated thereon to a thickness of about 0.3 mm was placed in a room at 20 + 1 C and 65 + 5%RH for 24 hours and a non-sticky coat formed on the surface of the adhesive. Hot water (70"C) was sprayed against the coat under conditions similar to those of Example 1 and the coat was not scattered or washed away. A steel panel with this adhesive coated thereon to a thickness of about 0.3 mm was mated with another steel panel just after application of the adhesive and was then heated for 30 minutes.

The tensile shear strength of the combined panels was 11 6 kg/cm2 and the T-peal strength thereof was 4.2 kg/25 mm width as measured in the same manner as described in connection with Example 1.

Example 3 An adhesive was prepared by mixing 42 parts of the epoxy resin paste similar to that used in Example 1, 100 parts of bisphenol F diglycidyl ether (Epycron 830, tradename for Dai-Nippon Ink a Chemicals, Inc.'s product with an epoxy equivalent of 1 72 and a viscosity of 3,450 cps/25 C), 100 parts of trimethyrol propane tri-glycidyl ether (Epotohto YH301, tradename for Tohto Chemical Industry Co.'s product with an epoxy equivalent of 155 and a viscosity of 190 cps/25 C), 100 parts of Cashew 2520, 2 parts of cobalt naphthenate solution, 3 parts of lead naphthenate solution, 100 parts of inorganic filler, and 10 parts of silicic anhydride.

The adhesive was found to have a viscosity of 32,000 cps/20 C and to be coatable uniformly on a steel panel using a sprayer. A steel panel with the adhesive coated thereon to produce a thickness of about 0.3 mm was placed in a room for 24 hours under conditions similar to those of Example 1 and a nonsticky coat was formed on the surface of the coated adhesive. Hot water was sprayed against the coat under conditions similar to those of Example 1, and the coat not scattered or washed away. A steel panel with this adhesive coated thereon to produce a thickness of about 0.3 mm was mated with another steel panel just after application of the adhesive and was then heated at 170"C for 30 minutes. The tensile shear strength of the combined panels was 1 88 kg/cm2 and the Tpeal strength thereof was 5.1 kg/25 mm width.

Example 4 A setting agent solution was prepared by mixing and dissolving, at 60"C, 100 parts of boron trifluoride methyl amine complex solt and 100 parts of diethylene glycol. An adhesive was prepared by mixing 200 parts of the setting agent solution, 30 parts of CTBM denatured bisphenol A diglycidyl ether (Epycron TSR960, tradename for Dai Nippon Ink a Chemicals, Inc.'s product with an epoxy equivalent of 238 and a viscosity of 77,000 cps/25 C), 50 parts of 3, 4-epoxy cyclohexil methyl-3, 4-epoxy cyclohexane carboxylate (Chissonox 221, tradename for Union Carbine Co.'s product with an epoxy equivalent of 134), 20 parts of Epycoat 828, 100 parts of Cashew 2520, 2 parts of cobalt naphthenate solution, 3 parts of lead naphthenate solution, and 5 parts of silicic anhydride and dispersing the mixture uniformly using a 301 kneader.

The adhesive was found to have a viscosity of 370,000 cps/20 C and to be coatable uniformly on a steel plate using a sprayer. A steel panel with the adhesive coated thereon to produce a thickness of about 0.3 mm was placed in a room under conditions similar to those of Example 2 and a non-sticky coat was formed on the surface of the coated adhesive.

A steel panel with this adhesive coated thereon was mated with another steel panel and was then heated under conditions similar to those of Example 1. The tensile shear strength of the combined panels was 94 kg/cm2 and the T-peal strength thereof was 5.5 kg/25 mm width.

Example 5 An epoxy resin paste was prepared by mixing 110 parts of Epycoat 828, 100 parts of dicyandiamide, and 40 parts of N, N-dimethyl-N'-(2, 4-dichlorophenyl) urea and crushing the mixture in a roller mill. An adhesive was prepared by mixing 50 parts of the epoxy resin paste, 100 parts of Epycoat 828, 78 parts of 1 ,6-hexane diol diglycidyl ether, 100 parts of Cashew 2520, 2 parts of cobalt naphthenate solution, 3 parts of lead naphthenate solution, and 10 parts of silicic anhydride and dispersing the mixture uniformly using a colloid mill.

The adhesive was found to have a viscosity of 8,500 cps/20 C. A steel panel with the adhesive coated thereon to produce a thickness of about 0.1 mm was placed in a room for 24 hours under conditions similar to those of Example 1 and a non-sticky coat was formed on the surface of the coated adhesive.

The surface of the coated steel panel having thereon a hardened film was found to have 3H pencil hardness (measured in accorrance with JIS C3203) after it was heated at 130"C for 60 minutes. The metal exposed portion of the coated steel panel was coated for protection with an epoxy resin adhesive (Semedain No. 1510, tradename for Semedain Co.'s organic solvent containing epoxy resin adhesive) and heated at 80"C for 2 hours to prepare a test piece for the salt spray test (JIS Z237 1). After the test piece was exposed to salt spray for 1 ,000 hours, the surface of the text piece was found to have good rustproofing property without floating off of the coat due to occurrence of rust.

The adhesives described above in connection with Examples 1 to 5 have the property of forming a protective coat on their surfaces when exposed to air.

Example 6 An epoxy resin paste was prepared by mixing 110 parts of Epycoat 828, 100 parts of dicyandiamide, and 40 parts of N, N-dimethyl-N'-(2, 4-dichlorophenyl) urea and crushing the mixture in a roller mill. An adhesive was prepared by mixing 50 parts of the epoxy resin paste, 200 parts of bis-phenol F diglyci dyl ether (Epycron 830, trade name for Dai Nippon Ink a Chemicals, Inc.'s product), 100 parts of 1, 6-hexane diol diacrylate, 2 parts of benzil, 100 parts of inorganic filler (calcium carbonate fine powder made by Shiraishi Cal cium Co.), and 10 parts of silicic anhydride.

This adhesive has the property of forming a protective coat on its surface when exposed to radiation including ultraviolet rays. Thus, a radiation illuminating station is additionally provided in the panel assembling line of Fig.

1 after the seaming station. Any conventional radiation illuminating apparatus may be used in the station.

Example 7 An adhesive was prepared by mixing 10 parts of a solution consisting of 5 parts of boron trifluoride ethyl amide complex salt and 5 parts of ethylene glycol, 100 parts of Epycron 830, 20 parts of tetra phenyl di-propylene glycol di-phosphite, and 5 parts of silicic anhydride.

This adhesive has the property of forming a protective coat by reaction with water.

Experiments show that the desirable thickness of adhesive coated on a panel is in the range of 50 to 500 microns. The vehicle component such as a vehicle hood will be contorted if adhesive coat thicknesses above the range are used, and the rust proofing effect will be reduced and cracks will be produced due to contraction of the adhesive upon setting, if adhesive coat thicknesses below the range are used.

The above described panel assembling method provides the following distinct advantages: First, the structural adhesive can be coated on the outer panel using a sprayer to provide a uniform thickness. This eliminates the possibility of the adhesive being squeezed out upon seaming of the inner and outer panels and thus the need for a process to wipe off the squeezed adhesive. Second, the structural adhesive is coated not only on the connection area of the outer panel to be seamed with the inner panel but also on its vicinity on which zinc-enriched primer has been coated for rust proofing in conventional methods. Thus, it eliminate the needs for any special rust proofing process.Third, the adhesive coated on the outer panel has the property of forming a protective coat on its surface when exposed to air, water or radiation, thereby preventing the coated adhesive from clinging to other substances or being washed away during pretreatment. Thus the rust proofing effect can be positively kept after the panels are assembled to form a vehicle component.

CLAIMS (31 May 1979) 1. A method of assembling panels, which comprises; (a) spraying a rust-proofing thermosetting adhesive to coat the same on and about the connection area of a first panel which is to be fixed to the connection area of a second panel; (b) bringing together the connection areas of the first and second panels to form a vehicle component; (c) installing the vehicle component to a vehicle body; and (d) heating the vehicle body to set the thermosetting adhesive.

2. A panel assembling method as claimed in Claim 1, wherein the thermosetting adhesive has the property of forming a protective coat on its surface when exposed to air.

3. A panel assembling method as claimed in Claim 1 or Claim 2, wherein the thermosetting adhesive consists essentially of about 42 parts of epoxy resin paste consisting of about 110 parts of bisphenol A diglycidyl ether and about 100 parts of dicyandiamide, about 100 parts of bisphenol A diglycidyl ether, about 100 parts of 1, 6-hexane diol diglycidyl ether, about 100 parts of modified cashew-nut shell oil, about 2 parts of mineral spirit solution of cobalt naphthenate with cobalt content of about 8%, about 3 parts of mineral spirit solution of lead naphthenate with lead content of about 15%, about 100 parts of inorganic filler, and about 10 parts of silicic anhydride.

4. A method as claimed in Claim 1 or Claim 2, wherein the thermosetting adhesive comprises about 1 20 parts of epoxy resin paste consisting of about 100 parts of bisphenol A diglycidyl ether and about 20 parts of dicyandiamide denatured setting agent, about 100 parts of 1, 6-hexane diol diglycidyl ether, about 100 parts of linseed oil denatured medium oil alkyd resin, and about 2 parts of mineral spirit solution of cobalt naphthenate with cobalt content of about 8%.

5. A method as claimed in Claim 1 or Claim 2, wherein the thermosetting adhesive comprises about 42 parts of epoxy resin paste consisting of about 110 parts of bisphenol A diglycidyl ether and about 100 parts of dicyandiamide, about 100 parts of bisphenole F diglycidyl ether, about 100 parts of tri-methyrol propane tri-glycidyl ether, about 100 parts of modified cashew-nut shell oil, about 2 parts of mineral spirit solution of cobalt naphthenate with cobalt content of about 8%, about 3 parts of mineral spirit solution of lead naphthenate with lead content of about 15%, about 100 parts of inorganic filler, and about 10 parts of silicic anhydride.

6. A method as claimed in Claim 1 or Claim 2, wherein the thermosetting adhesive comprises about 200 parts of setting agent solution consisting of 100 parts of boron trifluoride methyl amine complex solt and about 100 parts of diethylene glycol, about 30 parts Or CTBM denatured bis-phenol A diglycidyl ether, about 50 parts of 3, 4epoxy cyclohexil methyl3, 4-epoxy cyclohexene carboxylate, about 20 parts of bisphenol A diglycidyl ether, about 100 parts of modified cashew-nut shell oil, about 2 parts of mineral spirit solution of cobalt naphthenate with cobalt content of about 8%, about 3 parts of mineral spirit solution of lead naphthenate with lead content of about 15%, and about 5 parts of silicic anhydride.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. cium Co.), and 10 parts of silicic anhydride. This adhesive has the property of forming a protective coat on its surface when exposed to radiation including ultraviolet rays. Thus, a radiation illuminating station is additionally provided in the panel assembling line of Fig.

5. A method as claimed in Claim 1 or Claim 2, wherein the thermosetting adhesive comprises about 42 parts of epoxy resin paste consisting of about 110 parts of bisphenol A diglycidyl ether and about 100 parts of dicyandiamide, about 100 parts of bisphenole F diglycidyl ether, about 100 parts of tri-methyrol propane tri-glycidyl ether, about 100 parts of modified cashew-nut shell oil, about 2 parts of mineral spirit solution of cobalt naphthenate with cobalt content of about 8%, about 3 parts of mineral spirit solution of lead naphthenate with lead content of about 15%, about 100 parts of inorganic filler, and about

10 parts of silicic anhydride.

6. A method as claimed in Claim 1 or Claim 2, wherein the thermosetting adhesive comprises about 200 parts of setting agent solutioneconsisting of 100 parts of boron trifluoride methyl amine complex solt and about 100 parts of diethylene glycol, about 30 parts of CTBN modified bis-phenol A diglycidyl ether, about 50 parts of 3, 4-epoxy cyclohexil methyl-3, 4-epoxy cyclohexene carboxylate, about 20 parts of bisphenol A diglycidyl ether, about 100 parts of modified cashew-nut shell oil, about 2 parts of mineral spirit solution of cobalt naphthenate with cobalt content of about 8%, about 3 parts of mineral spirit solution of lead naphthenate with lead content of about 15%, and about 5 parts of silicic anhydride.

7. A panel assembling method as claimed

in Claim 1 or Claim 2, wherein the thermosetting adhesive comprises about 50 parts of epoxy resin paste consisting of 110 parts of bisphenol A diglycidyl ether, about 100 parts of dicyandiamide and about 40 parts of N,Ndimethyl-N'-(2, 4-dichlorophenyl) urea, about 100 parts of bisphenol A diglycidyl ether, about 78 parts of 1, 6-hexane diol diglycidyl ether, about 100 parts of modified cashewnut shell oil, about 2 parts of mineral spirit solution of cobalt naphthenate with cobalt content of about 8%, about 3 parts of mineral spirit solution of lead naphthenate with lead content of about 15%, and about 10 parts of silicic anhydride.

8. A method as claimed in Claim 1, wherein the thermosetting adhesive has the property of forming a protective coat on its surface when exposed to radiation.

9. A method as claimed in Claim 8, wherein the thermosetting adhesive comprises 50 parts of epoxy resin paste consisting about 110 parts of bisphenole A diglycidyl ether, about 100 parts of dicyandiamide and about 40 parts of N,N-dimethyl-N'-(2, 4-dichlorophenyl) urea, about 200 parts of bisphenol F diglycidyl ether, about 100 parts of 1, 6hexane diol diacrylate, 2 parts of benzil, about 100 parts of inorganic filler, and about 10 parts of silicic anhydride.

10. A method as claimed in Claim 1, wherein the thermosetting adhesive has the property of forming a protective coat on its surface when exposed to water.

11. A method as claimed in Claim 10, wherein the thermosetting adhesive comprises about 10 parts of a solution consisting of about 5 parts of boron trifluoride ethyl amide complex salt and about 5 parts of ethylene glycol, about 100 parts of bisphenol F diglycidyl ether, about 20 parts of tetra phenyl dipropylene glycol di-phosphite, and about 5 parts of silicic anhydride.

12. A method as claimed in Claim 1 and substantially as described in any one of the specific examples hereinbefore set forth.

CLAIMS (12th Sep 1979) 4. A method as claimed in Claim 1 or Claim 2, wherein the thermosetting adhesive comprises about 1 20 parts of epoxy resin paste consisting of about 100 parts of bisphenol A diglycidyl ether and about 20 parts of modified dicyandiamide hardener, about 100 parts of 1, 6-hexane diol diglycidyl ether, about 100 parts of linseed oil modified medium oil alkyd resin, and about 2 parts of mineral spirit solution of cobalt naphthenate with cobalt content of about 8%.