JPH0251722B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for inserting thread into a veneer veneer or a log being cut.

Conventionally, for example, "veneer joining method"
6498) or "A device for embedding thread in the end edge of raw wood in rotary lace" (Special Publication No. 6498)
49-6642) or ``Method for processing veneer veneer'' (Japanese Patent Publication No. 49-32052), on the surface of veneer veneer (hereinafter simply referred to as veneer) or the raw wood being cut. Attempts have been made to strengthen or join the veneer by applying a scoring knife to form kerfs in the direction substantially perpendicular to the fibers on the surface, and by embedding threads in the kerfs. Although various efforts have been made, sufficient effectiveness has not yet been achieved.

That is, in all of the conventional methods described above, a perpendicular V-shaped (wedge-shaped) cut groove is formed on the surface of the veneer, and threads are laid in the cut groove, and the relationship between the cut groove and the thread is as follows. The state is as illustrated in FIGS. 1 to 3. As is clear from the figure, the wood fibers on the side walls of the kerf, which had been deformed for a while as the kerf 2 was formed, recover due to their elasticity and hold the thread 3.
In this case, since the kerf 2 is V-shaped, the yarn 3 tends to be pushed out in the direction in which the kerf 2 opens as it is restored. Moreover, as is clear from FIG. 3, even after restoration, the kerf 2 remains V-shaped, so the thread buried within the kerf easily moves toward the opening of the kerf.
For example, even with a slight external force such as the weight of the veneer 1, the threads are easily pulled out of the cut groove, and the effect is extremely insufficient and unstable, which hinders the actual handling of the veneer. However, it was not suitable for practical use.

In addition, as mentioned above, since the thread is located near the opening in the kerf, the depth of the kerf must be deep, and thin veneer (used for the front and back surfaces of plywood) (usually 0.6 to 1.5 mm) cannot be applied at all. Therefore, such thin veneers are currently reinforced or bonded by applying bonding tape or the like to the surface.
Extra auxiliary materials, labor, etc. are wasted.

Furthermore, even when trying to supplement the effect by using an adhesive in combination, for example by impregnating the thread with an adhesive, the initial effect until the adhesive hardens is reliably guaranteed by the thread alone. As a result, the adhesive may harden after the thread moves in the cut groove due to external forces such as the weight of the veneer, resulting in problems such as steps and gaps on the joint surface of the veneer. occurs, and the effect of the combined use of adhesives has not yet been fully demonstrated.

In addition, as methods similar to the conventional methods mentioned above, for example, "Improvement of method for preventing veneer damage during plywood production process" (Japanese Patent Publication No. 35-4246) or "Method of joining green veneers with thread" (Japanese Patent Publication No. 54-3926)
As disclosed in et.
A method of embedding a thread in the cut groove has also been attempted, but when forming the cut groove diagonally on the surface in this way, due to the nature and direction of the wood fibers, it is inevitable that the cutter will be cut as it is formed. A tip crack will occur at the tip of the veneer, and there is a risk that the veneer will be separated from the kerf portion and become completely unusable. In other words, not only is the thickness of the applicable veneer thicker than the former (kerfs perpendicular to the surface), but the force that holds the threads in the grooves becomes even weaker due to the occurrence of tip cracks. Even if a slight external force such as the weight of the veneer acts on the thread, the kerf opens and the thread is pulled out, making the effect even more unstable. After all, it is difficult to put it into practical use.

The present invention was developed to eliminate the drawbacks of the conventional methods described above, and by thoroughly analyzing the physical properties of wood fibers based on various experiments, This product has succeeded in achieving excellent reinforcing or bonding effects using the cut grooves and threads, and can be applied not only to high-speed processing, but also to the front and back surfaces of plywood, from thick veneers such as core veneers. This invention can be applied to a wide range of applications, including thin veneers, and completely breaks away from conventional methods, making it an extremely effective invention.

The present invention will be described below based on an example of implementation illustrated in the drawings.

Therefore, the first aspect of the present invention is that, as is clear from FIG. Apply a scoring knife to the surface,
When forming a kerf in a direction substantially perpendicular to the fibers, the deepest part of the kerf cut by the cutting edge of the knife is expanded in the width direction by the knife fillet, and the kerf 4 in the expanded state is For example, as illustrated in FIGS. 7 to 9, the blade of a scoring knife 5 having a cutting edge line 5a of an appropriate length is inserted into the cutting edge line. 5a facing upward in the running direction of the raw wood or veneer, and so that the cutting edge line 5a is approximately perpendicular to the fiber direction on the surface of the raw wood or veneer, that is, to the left and right with respect to the running direction. Cut grooves 4 are formed by biting to a predetermined depth so as not to tilt. At this time, the blade of the scoring knife 5 is caused to follow the cutting edge at the deepest part of the kerf, and the blade of the knife pushes the deepest part of the kerf wider in the width direction, Furthermore, for example, a thread outlet hole 6 is drilled at an appropriate position on the blade of the scoring knife 5 located within the kerf, and the thread 3 is led out and buried in the kerf in the expanded state. It is something.

As described above, the present invention expands the deepest part of the kerf in the width direction when forming the kerf.
As is clear from FIG. 5, even the wood fibers on the innermost side wall of the kerf are compressed and deformed.
However, since the bonding relationship with the wood fibers directly below the kerf has been reduced or severed, the wood fibers on the side walls of the kerf, which had been deformed for a while as the kerf was formed, are restored by elasticity and are able to form yarns. When clamping, the kerf side wall restores substantially uniformly over the entire depth, and as a result, the thread is not pushed out from the position where it was led out as it restores, and this is also clear from Figure 6. After restoration, the shape of the kerf is approximately the same width throughout the entire depth, so the thread buried within the kerf can be moved in any direction by a small amount of external force. It does not move and exhibits extremely excellent reinforcing or joining effects.

In addition, since the thread is guided out by pushing the kerf wide in the width direction to the deepest part, it is easy to guide the thread to the deepest part of the kerf. Since there is less tendency for the material to be extruded, it becomes possible to make the depth of the kerf shallower than in the past, and it also becomes possible to apply it to thin veneers, which was not possible in the past.

Furthermore, it is also possible to use an adhesive in combination, for example by impregnating the thread with an adhesive, and in this case as well, the initial effect until the adhesive hardens is ensured by the thread. , there is no problem such as the formation of steps or gaps on the joint surfaces of the veneers or in the cracked parts, and the effect of the combined use of the adhesive can be fully demonstrated.

In addition, as for the shape of the above-mentioned scoring knife, it is preferable that the cutting edge is formed by providing a cutting surface on both sides in order to prevent the swivel caused by cutting. However, if the blade is thin, for example, A cutting edge formed by providing a cutting surface may also be used. In addition, it is preferable that the cutting edge line is inclined in the direction of pushing the fibers, since the formation of the cutting groove is smooth. This is where the restoring force of the side wall of the kerf is not fully utilized, so the blade of the scoring knife is thin and uniform over the entire depth of the kerf in order to avoid tip cracking. is preferred. As long as the amount is small, there is no problem even if the deepest part of the kerf is thicker, or vice versa, if the deepest part of the kerf is thinner.

For example, even if the blade has a substantially triangular cross section as shown in FIG. 10, or as shown in FIG. There is no problem even if the kerf is installed on the side), but the key point is that it is possible to form a kerf of the desired depth, and that it can be pushed out in the width direction even to the deepest part of the kerf, and that it is possible to spread the kerf in the expanded state. In addition, there is no problem as long as the thread can be drawn out smoothly or while applying tension arbitrarily as necessary.

In addition, the angle at which the scoring knife cuts into the veneer or raw wood is determined from the viewpoint of avoiding the occurrence of tip cracks.
It is preferable to operate the blade so that it is perpendicular to the surface of the veneer or raw wood, but it may be slightly slanted, and according to experiments, it is 0.6 to 1 mm.
When cutting grooves with a depth of approximately 1 mm were formed using a thick scoring knife, almost no tip cracking was observed up to approximately 75 degrees from the surface for veneer and approximately 70 degrees from the surface for logs. . In addition, the depth of the kerf is usually about 3/10 to 7/10 of the thickness of the veneer, but if the kerf is shallow, tip cracking is likely to occur; There was a tendency for tip cracking to occur less easily if the depth was deeper.

In addition, the yarn is preferably a yarn that entangles well with the veneer fibers, or a yarn that has a large frictional force with the veneer fibers. Threads or the like coated on the surface are even more effective. Also, the thickness of the thread is usually
The diameter is approximately 0.2 to 1 mm, but it is preferable to select it appropriately considering various conditions such as the thickness of the veneer or the depth of the kerf. Furthermore, the number of strands buried in the kerf is not limited to one. , there may be more than one if necessary.

Further, the kerf illustrated in FIG. 4 is a kerf that extends orthogonally in a direction substantially orthogonal to the fibers, so to speak, but it may be a kerf that extends in a somewhat meandering manner in a direction substantially orthogonal to the fibers. Alternatively, the depth of the kerf may be uniform over the entire length or may vary slightly.

Next, the second invention will be explained. In addition to the first invention described above, this second invention includes a method of embedding the thread while pressing it against the bottom of the kerf in order to reliably bury the thread at a suitable position within the kerf. The purpose of this invention is to further improve the above-mentioned effects.

That is, as illustrated in FIGS. 12 to 14,
Hold the blade of a scoring knife 5 having a cutting edge line 5a of an appropriate length with the cutting edge line 5a facing upward in the running direction of the raw wood or veneer, and make sure that the cutting edge line 5a is Alternatively, the cut grooves 4 are formed by cutting in to a predetermined depth so as to be substantially perpendicular to the fiber direction on the surface of the veneer, that is, so as not to be inclined to the left or right with respect to the running direction. At this time, the blade of the scoring knife 5 is caused to follow the cutting edge at the deepest part of the kerf, and the blade of the knife pushes the deepest part of the kerf wider in the width direction, Furthermore, for example, a thread outlet hole 6 is bored at an appropriate position on the blade of the scoring knife 5 located within the cut groove, and the thread 3 is guided into the cut groove in the expanded state.
Further, for example, the blade 5b of the scoring knife 5, which is located at a lower position in the running direction than the outlet hole for the thread 3, is shaped to protrude toward the bottom of the kerf, so that the thread 3 can be guided into the kerf in the expanded state. The thread is buried while being pressed against the bottom of the cut groove.

As described above, the present invention buries the thread guided into the cut groove while pressing it against the bottom of the cut groove, so that the thread is reliably paid out at the start of burying, which is also clear from Fig. 16. Since the side wall of the kerf is restored while the thread is pressed against the bottom of the kerf, the thread can be buried in the deepest part of the kerf extremely reliably. However, the innermost side wall of the kerf is prevented from restoring due to the presence of the thread.
As illustrated in FIG. 15, after restoration, the shape of the kerf will press and enclose the yarn, and the yarn will be very reliably retained within the kerf, resulting in even better reinforcing or joining effects.

In addition, since the thread can be buried extremely reliably in the deepest part of the cut groove, the depth of the cut groove can be made shallower, and it can be applied to thin veneers, which was previously impossible to do. Can be done. This method significantly simplifies the process compared to the method of attaching bonding tape or the like to the surface, and since there is no reinforcing or bonding material left on the surface, it is possible to produce a low-cost yet high-quality single piece. This allows for reinforcement or bonding of plates. Incidentally, experiments have confirmed that thread used for sewing can be used to reinforce thin 0.6mm veneers used on the front and back sides of plywood.

Note that the shape of the scoring knife is not limited to the shapes illustrated in FIGS. 12 to 14; for example, as illustrated in FIG. For example, as illustrated in FIG.
The key point is that it is possible to form a kerf of a desired depth, and it is also possible to spread the kerf in the width direction to the deepest part of the kerf. Any structure may be used as long as the thread can be buried smoothly while being pressed against the bottom of the cut groove, or while applying tension as needed.

FIGS. 21 and 22 illustrate the case where the above-mentioned scoring knife is attached to a peripheral drive type veneer race, where 16 is a veneer cutting blade, and 17 is a veneer cutting blade facing the veneer cutting blade 16. The pressure member 24 provided at the position has a large number of piercing bodies 18 around it.
This figure shows a rotating roll including a large number of drive members 19 arranged at appropriate intervals in the axial direction. In this veneer lace, the scoring knife 5 is held by a knife holder 13, and the threads 3 are embedded in the veneer 1 cut from the raw wood 20. Since the running direction of the plate is non-linear and the bottom of the kerf is also non-linear, as is clear from FIG. 21, the bottom surface of the scoring knife 5 is formed to follow the running direction of the bottom of the kerf. Must-have. However, the outer circumferential drive type veneer lace is suitable for embedding threads because it causes fewer troubles near the cutting edge than the conventional spindle drive type veneer lace. In the figure, 14 is a base metal, 15 is a cutting edge stand, 21 and 22 are veneer guides, 23 is a thread guide roller, and 25 is a holder.

Furthermore, the scoring knife 5 illustrated in FIG. 19 has a cutting depth regulating member 10 provided on the side surface of the blade, but when such a cutting depth regulating member is provided,
Experiments have confirmed that the occurrence of tip cracking can be prevented by regulating the depth. Moreover, this effect is exhibited not only when the cutting depth regulating member is provided integrally with the blade of the scoring knife as illustrated in the drawing, but also when it is provided separately adjacent to the scoring knife. Therefore, the cutting depth may be regulated, for example, by bringing the tip of a knife holder that holds the scoring knife into contact with the surface of the log or veneer.

Furthermore, the scoring knife 5 illustrated in FIG. 20 has adhesive outlet holes 11 bored at appropriate positions on the blade located within the kerf. The adhesive 12 can be embedded in the kerf and used in combination. Various types of adhesives, such as wet-curing adhesives and thermosetting adhesives, are readily available, and from among these adhesives, one suitable for the properties of the veneer or the conditions of the processing process is selected as appropriate. There is no problem if it is used as an adhesive, and if necessary, there is no problem even if multiple types of adhesives with different curing conditions are used together.

As is clear from the above, the present invention has been made by accumulating various experiments and observations in order to fundamentally improve the conventional method of reinforcing or joining veneers using grooves and threads.
By creating a completely new kerf that breaks away from existing concepts, or by embedding the thread at a suitable position within the kerf, we have created a new kerf, which has hitherto been beyond the realm of theoretical speculation. This method has made it possible to strengthen or join veneers with thread, and it can be applied not only to thick veneers, which were the target of conventional methods, but also to the surface of plywood, which was impossible to implement with conventional methods. The present invention can be applied to thin veneers used for the back surface, and the effects of implementing the present invention in plywood factories are extremely large.

[Brief explanation of the drawing]

The drawings are for explaining the present invention, and
Fig. 1 is a perspective view illustrating the relationship between the kerf and the thread in the conventional method, Fig. 2 is a partial sectional view taken along A-A in Fig. 1, and Fig. 3 is a partial sectional view taken along BB in Fig. 1. 4 is a perspective view illustrating the relationship between the cut groove and the thread in the present invention, and FIG. 5 is a line C-C in FIG. 4.
FIG. 6 is a partial sectional view taken along line DD in FIG.
The figure is a side view of FIG. 7, FIG. 9 is a bottom perspective view of FIG. 8, FIGS. 10 and 11 are top perspective views illustrating other embodiments of the scoring knife, and FIG. 12 is a cut groove. Fig. 13 is a side view of Fig. 12, Fig. 14 is a top perspective view of Fig. 13, and Fig. 15 shows the kerf sides restored. FIG. 16 is a partial cross-sectional view illustrating the state in which the thread is pressed against the bottom of the groove, and FIGS. 17 to 20 are bottom views illustrating other embodiments of the scoring knife. A perspective view, FIG. 21 is a side view illustrating a state in which threads are embedded in the veneer lace, and FIG. 22 is a front view of FIG. 21. 1...Single plate, 2...Cutting groove by conventional method, 3...
...Thread, 4... Cut groove according to the present invention, 5... Creasing knife, 6... Thread outlet hole, 7... Thread outlet tube, 8...
...Thread guide groove, 9...Thread lead-out guide tube, 10...
Cutting depth regulating member, 11...adhesive outlet hole, 1
2...Adhesive, 13...Knife holder, 15...
...Cutter stand, 16... Blade for cutting veneer, 17... Pressure member, 20... Raw wood.

Claims (1)

[Claims] 1. A scoring knife is applied to the surface of the veneer veneer or the raw wood being cut, to form a kerf in a direction substantially perpendicular to the fibers on the surface, and to insert thread into the kerf. In the embedding method, the scoring knife is cut so that the cutting edge line of the knife is substantially perpendicular to the fiber direction on the surface, and at least a part of the knife blade is cut by the cutting edge of the knife. The blade of the knife is applied so as to follow the cutting blade at the deepest part of the cut groove, and the blade of the knife is used to spread the deepest part of the cut groove in the width direction, and the thread is inserted into the spread cut groove. A thread insertion method characterized by extracting and burying the thread. 2. A thread insertion method in which a scoring knife is applied to the surface of a veneer veneer or a log being cut, a cut groove is formed on the surface in a direction substantially perpendicular to the fibers, and the thread is buried in the cut groove. , the scoring knife is cut so that the cutting edge line of the knife is approximately perpendicular to the fiber direction of the surface, and at least a part of the knife blade is cut by the cutting edge of the knife at the deepest part of the kerf. The blade of the knife is used to spread the deepest part of the kerf in the width direction, and the thread is guided into the kerf in the expanded state. A thread insertion method characterized by pressing the thread into the deepest part of the cut groove and embedding the thread.