JPH0245564B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention involves applying an adhesive in a dropwise manner to the front end surface of the subsequent veneer veneer while conveying the veneer veneer in the fiber direction or in the direction orthogonal to the fiber direction. This invention relates to an improvement of an end face gluing device in a veneer joining machine that collides with the rear end face of a preceding veneer veneer and joins it continuously.

[Conventional technology]

Conventional devices of this type include, for example, a gluing device in a veneer veneer horizontal stripping machine developed by the applicant in Patent No. 1046872 (Japanese Patent Publication No. 1046872 (Special Publication No. 55-40401)), which can freely appear and retract from the conveyor line of the veneer veneer. There is an end face gluing device that applies adhesive in a dropwise manner to the front end face by controlling the vertical movement of a gluing block installed in the front end face, and is also disclosed in a method for depositing bonded veneer veneers in Japanese Patent Application Laid-Open No. 53-24007. One of the conventional devices is an end face gluing device that sprays pressurized adhesive directly from a nozzle onto the rear end face of a veneer veneer.

[Problem to be solved by the invention]

In the former case, the end face gluing device of the prior art requires a distance between the preceding veneer veneer and the following veneer veneer by an amount commensurate with the process time for moving the gluing block onto the conveyor line. Therefore, when the required plate spacing is not sufficiently formed, such as when trying to increase productivity by high-speed conveyance, it not only becomes impossible to perform end face gluing by controlling the vertical movement of the gluing block. In the latter case, there was a serious problem in that the veneer veneer was damaged during the conveyance process due to the protruding action of the gluing block onto the conveyance line. This method uses an extremely common primary spray method that sprays the rear end of the plywood veneer from a nozzle for a short period of time, making it impossible to perform drip application in small amounts and instead applying adhesive in large quantities. This has the serious disadvantage of contaminating areas that should not be used, causing blocking, and wasting adhesive.The present invention aims to eliminate these disadvantages by providing an end face gluing device of this type. Gluing blocks and other utensils used for
In addition, without directly injecting the pressurized adhesive from the nozzle, an appropriate amount of adhesive is injected into the injection nozzle in the form of a droplet by instantaneous injection of pressurized air toward the front end surface of the veneer veneer. Edge gluing configured as a secondary type spray means that overlaps the injection operation of drip-shaped adhesive and the injection operation of drip-shaped adhesive to fly the adhesive to the front end surface of the veneer veneer and apply it again in a drip-like manner. The purpose is to provide equipment.

[Means to solve the problem]

In order to achieve the above object, the present invention fulfills the following (a) to (c):
This is an end face gluing device for a veneer bonding machine configured as a means.

(a) Injection nozzles equipped with on-off valves that inject adhesive in a drip-like manner are installed in a line below or above the conveyance line of the veneer veneer.

(b) A pressurized air injection nozzle equipped with an opening/closing valve for spraying adhesive is attached to the adhesive injection part of the injection nozzle toward the front end surface of the veneer veneer on the conveyance line.

(c) A veneer detector for detecting the front end surface of the veneer veneer on the conveyance line is associated with each opening/closing valve of the injection nozzle and the injection nozzle.

[Effect]

The end face gluing device of the present invention uses a pump to force-feed an adhesive such as a molten hot melt resin heated and melted by a heater or the like in a melting tank to an injection nozzle equipped with an on-off valve. The injection nozzle injects an appropriate amount of adhesive into the adhesive injection part in the form of a drop, for example, 5 or 6 drops, by momentarily opening the opening/closing valve.
In the case of molten hot melt resin, etc., which is injected in the form of droplets, the molten state is maintained. Next, by momentarily opening a pressurized air injection nozzle equipped with an on-off valve attached perpendicularly to the injection nozzle, the adhesive being injected into the adhesive injection part in a droplet is instantaneously released. The adhesive then flies to the side and is once again applied in a drip-like manner to the front end surface of the veneer veneer that is being transported, completing one end face gluing operation.

As explained above, the end face gluing device of the present invention injects an appropriate amount of adhesive such as molten hot melt resin onto an injection nozzle in a dropwise manner, and then injects pressurized air into the adhesive to form a front end face of a veneer veneer. End face gluing in a veneer bonding machine configured as a secondary type spray means, which overlaps the injection operation of drip-shaped adhesive and the injection operation of drip-shaped adhesive, in which the adhesive is sprayed up to the top and then applied again in the form of a drip. It is a device.

〔Example〕

An example of the implementation of the present invention will be explained by illustrating a case where a molten hot melt resin is used as an adhesive. FIGS. Improved end face gluing of a veneer joining machine that applies adhesive 2 in a dropwise manner to the front end face of the succeeding veneer veneer 4a and collides with the rear end face of the preceding veneer veneer 4b to continuously join the adhesive 2. In this example, an adhesive made of hot melt resin is first melted by a heater 9 in a melting tank 8, and a pump 11 is driven by an air cylinder 10 etc. installed at the bottom of the melting tank 8. The molten hot melt resin is fed under pressure to the injection nozzle 3 through the heat tube 12 which is heated and kept warm. The injection nozzle 3 is equipped with a heating heater 13, which maintains the molten state of the molten hot melt resin that is pressure-fed and injects it in an appropriate amount into the adhesive injection part 3a in a dropwise manner through the opening/closing valve 1. The opening/closing valve 1 is equipped with an operating mechanism 14 such as an air cylinder or a solenoid, and is operated by a veneer detector 7a at the front stage of a veneer detector 7 consisting of a photoelectric switch or the like placed on the conveyance line of the veneer veneer 4. A suitable amount of molten hot melt resin is injected in a drip form onto the adhesive injection part 3a according to a control signal detected each time the front end surface of the veneer veneer 4 is placed on standby for the next application of the adhesive 2. . Further, on the side of the adhesive injection part 3a of the injection nozzle 3, a pressurized air injection nozzle 6, which is equipped with an opening/closing valve 5 equipped with an operating mechanism such as a solenoid or a diaphragm in its path, is connected to the plywood veneer 4 on the conveyor line. It is attached toward the front end surface of the injection nozzle 3, that is, perpendicular to the adhesive injection direction of the injection nozzle 3, and receives pressurized air supplied from a pressurized air source such as the air compressor 15 as is or as needed. Accordingly, pressurized air preheated by the heating heater 16 is injected from the side toward the molten hot melt resin that has been injected into the adhesive injection part 3a of the injection nozzle 3 in the form of a droplet, and this injection causes the resin to fly away. The adhesive 2 such as molten hot melt resin is captured on the front end face of the veneer veneer 4, and one end face gluing operation is completed. In this case, the opening/closing valve 5 for the injection nozzle 6 is connected to the veneer detector 7 located downstream of the veneer detector 7 facing on the conveyance line of the veneer veneer 4.
An appropriate amount of pressurized air is injected momentarily according to a control signal detected each time the front end surface of the veneer veneer 4 arrives at the appropriate location by b, and in some cases, the veneer detector at the latter stage 7b, the control signal from the preceding stage veneer detector 7a is appropriately delayed by a timer, shift register, magnetic memory, etc., and the opening/closing valve is activated by waiting for the front end surface of the veneer veneer 4 to arrive at an appropriate location. 5 can also be controlled.

The device of the present invention is not limited to the adhesive 2 such as the molten hot melt resin of the above embodiment, and can be used with various types of adhesives such as room-temperature type adhesives as they are. By arranging them in multiple stages in the conveyance direction of 4, it is possible to apply two-component adhesives or different types of adhesives overlappingly, and furthermore, the pressurized air jetted from the jet nozzle 6 can coat the veneer in a single layer. Adhesive 2 flown toward the front end surface of plate 4
by suitable focusing means, e.g. injection nozzle 3.
Fine particles of the adhesive 2 flying from the adhesive injection part 3a of the veneer veneer 4 are ionized by high-voltage electricity.
It is also possible to prevent the particles from scattering by electrostatically focusing them on the front end surface of the substrate.

〔Effect of the invention〕

The present invention uses the jet of pressurized air configured as described above to fly the adhesive that has been injected onto the injection nozzle in a drip shape, and then spray it again onto the front end surface of the veneer veneer in a drip shape. Since this is an end face gluing device that applies adhesive to the end face, there is no need for objects such as gluing blocks to protrude onto the conveying line of the veneer veneer and obstruct the conveying operation, unlike in conventional devices, and the nozzle directly applies the adhesive to the rear end of the veneer veneer. It does not make it impossible to perform drip application in small amounts at a time, as is the case when spraying pressurized adhesive for a short period of time. This is the first time that it has been possible to spray an appropriate amount of adhesive in a drip-like manner onto the front end of the veneer veneer and apply it in minute amounts, so the gap between the preceding and succeeding veneer veneers can be adjusted. The jet speed of pressurized air can be reduced to the limit, and therefore, stable end gluing work can be performed even when trying to increase productivity by high-speed conveyance that narrows the gap between plates. Not only that, but the amount of adhesive drip applied can also be adjusted by injecting the appropriate amount of adhesive onto the injection nozzle in advance in the form of a drip, so there is no excess or deficiency in the amount of drip applied, and the veneer can be The overall process efficiency of the bonding machine has been dramatically improved, the product strength has become extremely stable, and the consumption of adhesive has been significantly reduced. The implementation effect is extremely remarkable as there was no damage at all.

[Brief explanation of drawings]

The figure shows an example of implementation of the present invention,
FIG. 1 is a side view, and FIG. 2 is a front view of the main parts. 1, 5... Opening/closing valve, 3... Injection nozzle, 3
a...Adhesive injection part, 4...Plywood veneer, 6...
Injection nozzle, 7...Single plate detector.

Claims (1)

[Claims] 1 While conveying the veneer veneer in the fiber direction or in the direction perpendicular to the fiber direction, adhesive is applied in drops to the front end surface of the succeeding veneer veneer, and this is caused to collide with the rear end surface of the preceding veneer veneer. In the veneer welding machine for joining veneer sheets in a shape, injection nozzles 3 equipped with opening/closing valves 1 for injecting adhesive in a dropwise manner are installed in a row below or above the conveyance line of the veneer veneers 4, and A pressurized air injection nozzle 6 equipped with an on-off valve 5 for spraying adhesive is attached to the adhesive injection part 3a of the nozzle 3 toward the front end surface of the veneer veneer 4 on the conveyance line, and the injection nozzle 3 An end face gluing device for a veneer joining machine, characterized in that a veneer detector 7 for detecting the front end face of the veneer veneer 4 on the conveyance line is associated with each of the on-off valves 1 and 5 of the injection nozzle 6.