JPS6347601B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Industrial Application Field The present invention is used in the field of plywood manufacturing, and is particularly applicable to veneer lace, veneer lace, veneer slicer, etc. Using a board as a target, apply molten hot melt resin to the top and end surfaces of the joints of small width veneers cut to a certain width in a T-shaped cross section and anchor them to form a series of joined veneers in a sash shape. The present invention relates to a method for joining veneers in which the pressing strength of the joint can be adjusted according to the thickness and strength of the veneers.

(b) Prior Art Conventionally, in this type of method for joining narrow width veneers, for example, as disclosed in Japanese Unexamined Patent Publication No. 51-26204, hot melt is applied to the tip surface of the narrow width veneer while the narrow width veneer is being transferred in a direction perpendicular to the fiber direction. Adhesive is applied, and it is brought into contact with the rear end of the preceding veneer that is waiting at the joint in the latter stage, and in this state, it is held between the top and bottom by low-temperature pressurizers and moved a predetermined distance in the direction of transport of the veneer. A method in which the hot melt adhesive is moved and the veneers are joined together by solidifying the hot melt adhesive, or a preceding method in which the trailing edge is cut by a cutting blade on an anvil roll, as in Japanese Patent Application Laid-Open No. 51-57805. Hot melt is dropped into the gap between the edges of the succeeding veneer whose front edge has been cut in the same way as the veneer, and the leading edge of the succeeding veneer is pressed against the trailing edge of the preceding veneer, and the hot melt is removed by a cooling roll. A method is known in which the veneer is joined by cooling the veneer while spreading it over the surface of the veneer joining end.

(C) Problems to be Solved by the Invention However, in all of the above conventional veneer joining methods, the end face of the veneer to be joined after the application of adhesive is brought into contact with the joined end face of the front veneer. In addition, since the pressing force is always constant, if the thickness of the veneer becomes thin or the material is weak, the joint end surface of the veneer may buckle or break during pressing. There was a problem that it could not be joined accurately due to bending.

The present invention solves the above-mentioned problems, allows adjusting the pressing strength of the joint end surfaces according to the thickness, material, etc. of the veneers to be joined, and always accurately joins the joint end surfaces with an appropriate pressing force. The purpose of this invention is to provide a veneer joining method that allows for the following.

(d) Means for solving the problem In order to solve the above-mentioned problem, the present invention cuts the trailing edge of the preceding veneer and cuts the trailing veneer at the veneer joint set at a predetermined position on the veneer transfer path. In a veneer joining method in which the veneers are joined by cutting the leading edge, applying molten hot melt resin to the joint portion of both veneers, and cooling the veneers by pressing, the following veneer is joined after the leading edge cutting is completed. The leading edge is moved to a required distance backward position from the trailing edge of the preceding veneer in the standby position, and a required gap is created between the leading edge of the trailing veneer and the trailing edge of the leading veneer. After forming, and then extruding and injecting molten hot melt resin into the gap in the form of a spot,
The succeeding veneer is moved forward by the required amount again, and the leading edge of the trailing veneer is brought into contact with the trailing edge of the preceding veneer, crushing the molten hot melt resin injected into the gap, and part of it is removed from the veneer. The amount of retraction of the reciprocating mechanism that causes the succeeding veneer to move backward and forward when the veneers are joined together by protruding from the upper surface and then pressing and cooling the molten hot melt resin from above to form an anchored state with a T-shaped cross section. The amount of advance relative to the bonded veneer is set to a required amount according to the thickness and strength of the bonded veneers, and the bonding pressing force can be adjusted by adjusting the mutual head difference.

(E) Embodiment The operation and embodiment of the present invention will be explained in detail with reference to the attached drawings. First, as shown in FIG.
b is the cutting blade 1b for the rear cutting operation of the preceding veneer 6.
is fed out downward and intersects with the receiving blade surface 2b located above the double-sided receiving blade 2 to close the conveyance path as it is. A gap is formed between the receiving blade 2 and the receiving blade surface 2a located below, allowing the subsequent veneer 3 to pass freely. In addition, since the carry-in conveyor 4 is also designed to move up and down together with the cutting blades 1a and 1b, the defective part near the front edge of the succeeding veneer 3 that is newly carried in by the carry-in conveyor 4 is removed by the two-sided receiving blade. 2 is protruded into the gap between the receiving blade surface 2a and the cutting blade 1a for front cutting. Next, as shown in Fig. 2, the defective part near the front edge protruding into the gap between the receiving blade surface 2a located below the double-sided receiving blade 2 and the cutting blade 1a for front cutting is Synchronizing with the timing when the cutting blade 1a arrives directly above the cutting blade 1a, the cutting blade 1a for the front cutting, the cutting blade 1b for the rear cutting, and the carry-in conveyor 4 simultaneously pay out upward, and perform a leading edge cutting operation in which the cutting blade 1a is fed in and raised. Therefore, the defective part is the cutting blade 1 for front cutting.
It is automatically cut by a and becomes chips 5a, which fall directly below and are separated. Therefore, during the cutting operation of the cutting blades 1a and 1b, the cutting blade 1a for front cutting is extended upward and intersects with the receiving blade surface 2a located below the double-sided receiving blade 2, thereby closing its delivery path. At the same time, a gap is formed between the cutting blade 1b for post-cutting that is fed upward and the receiving blade surface 2b located above the double-sided receiving blade 2, which allows the following veneer 3 to pass freely. become. At this time, the carry-in conveyor 4 also has a delivery member 4 attached to the tip of the carry-in conveyor 4.
a also rises together with the cutting blades 1a and 1b to cut the front edge of the subsequent veneer 3 that has finished cutting the leading edge, using the double-sided receiving blade 2 that is already in the standby position after the previous joining operation. It is stopped on the contour line of the trailing edge of the preceding veneer 6 on the receiving blade surface 2b located above. Next, as shown in FIG. 3, the following veneer 3 on the carry-in conveyor 4 is moved to a slightly rearward position by a reciprocating mechanism 11 such as an air cylinder mounted on the carry-in conveyor 4, or a cam mechanism in place of this. Then, the veneer 6 is normally moved back by about 0.5 to 1 mm, and a gap C is formed between the rear edge of the preceding veneer 6 and the front edge of the following veneer 3 in the standby position. Next, as shown in FIG. 4, a movable resin extrusion block 8 installed above the unloading conveyor 7 so as to be freely movable and retractable, and a movable resin cooling block 9 installed in parallel with the movable resin extrusion block 8 are integrally moved to the carry-in side. That is, it starts moving forward toward the gap between the cutting blade 1b for rear cutting and the upper surface of the front edge of the following veneer 3, and the adhesive discharge hole 8a of the movable resin extrusion block 8 reaches the front of the following veneer 3. It is stopped at a position directly above the gap C formed between the edge and the rear edge of the preceding veneer 6, and only the moving resin extrusion block 8 is lowered to near the end face of the front edge of the following veneer 3. let Then, the valve 8b of the movable resin extrusion block 8 is opened, and the molten hot melt resin supplied from the resin supply port 8c is extruded in a spot from the resin discharge hole 8a and injected into the gap C. Next, as shown in FIG. 5, at the same time as the moving resin extrusion block 8 finishes injecting the molten hot melt resin 10a, the moving resin extrusion block 8 and the moving resin cooling block 9 both retreat to the discharge side and return to the moving resin cooling block. The retracting operation is temporarily stopped at a point where 9 is located directly above the injected molten hot melt resin 10a. At this time, the carry-in conveyor 4 is also moved to a slightly forward position, that is, 0.5 to 1 mm.
The reciprocating mechanism 11 etc. is operated so that the reciprocating mechanism 11 moves forward by about 1 to 1.5 mm, and the trailing veneer 3 is placed on the trailing edge of the leading veneer 6 in the standby position due to the mutual drop. Press the end face of the front edge slightly forcefully to bring them into close contact. Therefore, the molten hot melt resin 10a injected into the gap C
With the abutting action, a part of the molten hot melt resin 10a comes to protrude somewhat from the upper surface of both veneers 3 and 6, and as a result, the molten hot melt resin 10a injected into the gap C in the form of a spot forms a slightly raised coating with a T-shaped cross section. Get dressed. Next, as shown in FIG. 6, the molten hot melt resin 10a is
When the coating with a slightly raised T-shaped cross section is completed, the movable resin cooling block 9 immediately descends and thinly presses the molten hot melt resin 10a applied to the veneer joint for the required time, e.g. The resin is pressed and cooled for about 0.3 to 1 second to solidify into a hot melt resin 10b having a T-shaped cross section. Next, the movable resin cooling block 9 which has finished cooling and solidifying the hot melt resin 10b and the movable resin extrusion block 8 installed in parallel thereto immediately rise as shown in FIG. 7 and retreat to the initial standby position. to wait for the next joining operation, and also to carry in conveyor 4 and carry out conveyor 7.
The conveyance operation of both the veneers 3 and 6 joined in a cross-shaped manner is resumed, and the following veneer 3 now becomes the leading veneer 6 and is connected to the receiving blade surface 2b located above the double-sided receiving blade 2. The leading veneer 6 is carried out onto the carry-out conveyor 7 through the gap with the cutting blade 4b for trailing cutting, as shown in Fig. 8.
The defective part near the rear edge is the cutting blade 1b for rear cutting.
The cutting blade 1a for front cutting, the cutting blade 1b for trailing cutting, and the carry-in conveyor 4 are simultaneously delivered downward, fed in, and lowered in synchronization with the time when the cutting blade 1a for front cutting arrives just below the cutting edge, and performs a trailing edge cutting operation. , the defective part is automatically cut by the cutting blade 1b for post-cutting to form chips 5b.
The veneer 4 temporarily remains on the transfer member 4a at the tip of the carrying-in conveyor 4, but is pushed out by the carrying-in of a new succeeding veneer 3 and falls directly below and is separated.

(F) Effects of the Invention Since the present invention is constructed as described above, the molten hot melt resin extruded into spots forms the leading edge of the succeeding veneer and the trailing edge of the preceding veneer. After being injected into the gap, the amount of movement of the reciprocating mechanism is adjusted by the required amount by setting the reciprocating mechanism's advance amount in excess of the predetermined amount of retraction according to the thickness of the plate and the type of material, and the amount of movement is adjusted based on the mutual head difference. The front edge of the board was crushed with an appropriate pressing force commensurate with the thickness of the board and the strength of the material, and the top surface of each board was painted to bridge the gap while correcting any bending during cutting. Since the hot melt resin with a T-shaped cross section is cooled and solidified, it is possible to always perform accurate joining regardless of the thickness or thinness of the plate or the strength or weakness of the material. The anchoring effect greatly increases the bonding strength, making it difficult for even relatively thick veneers to bend easily on either side.
In other words, not only was it possible to efficiently produce a strong bonded veneer product that would not easily break during handling in subsequent processes, but also the bonded end surfaces were extremely tightly abutted, thereby making it possible to It has various effects, such as significantly improving the quality of plywood products and gluing work in subsequent steps.

[Brief explanation of the drawing]

The figure shows an example of implementation of the present invention,
1 to 8 are operation diagrams according to the veneer cutting and joining order. 3... Following veneer, 6... Leading veneer, 8... Moving resin extrusion block, 9... Moving resin cooling block, 10a, 10b... Molten hot melt resin,
C...Gap.

Claims (1)

[Claims] 1 At the veneer joint set at a predetermined position on the veneer transfer path, cut the trailing edge of the preceding veneer, cut the leading edge of the following veneer, and apply and press molten hot melt resin to the joint of both veneers. In a veneer joining method in which the veneers are joined by cooling, the leading edge of the succeeding veneer after the leading edge cutting is finished is cut by a required amount from the trailing edge of the leading veneer in the standby position. The veneer was moved to the rear position, a required gap was formed between the front edge of the succeeding veneer and the rear edge of the preceding veneer, and then molten hot melt resin was extruded and injected into the gap in the form of a spot. After that, the succeeding veneer is moved forward by the required amount again, and the leading edge of the trailing veneer is brought into contact with the trailing edge of the preceding veneer, crushing the molten hot melt resin injected into the gap and partially crushing it. A reciprocating mechanism for causing the succeeding veneer to move backward and forward when the veneers are joined together by protruding onto the upper surface of the veneer, and then cooling the molten hot melt resin by pressing it from above to form an anchored state with a T-shaped cross section. A veneer joining method characterized in that the amount of advancement relative to the amount of retreat is set to a required amount extra depending on the thickness and strength of the veneers to be joined, so that the joining pressing force can be freely adjusted by the mutual head difference.