JPH0367001B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a veneer veneer tenderizing device.

Traditionally, many small cracks have been formed in veneer veneers (hereinafter simply referred to as veneers) for the purpose of eliminating cracks, homogenizing them, and improving yield.
So-called tenderizing devices have been developed, but all of them have been proposed in a form that does not balance the reliability and stability of small crack formation with the simplicity of the mechanism (device), and their practicality in plywood factories is limited. There was a problem.

For example, the present applicant previously published ``Method and Apparatus for Forming Small Cracks in Veneer Plywood'' (Japanese Unexamined Patent Application Publication No. 51-197).
110007), a conveyance means in which a plurality of narrow rollers are intersected in an alternating manner, and the axis of the carry-in roller group and the axis of the carry-out roller group are brought very close to each other. By using
In this system, tensile force is applied to the veneer due to the difference in conveyance speed, and a large number of small cracks are formed in sequence. Since the magnitude of the force is almost constant, it is possible to form small cracks more stably than other conventional devices. By changing the spacing between the cores, it was also possible to change the pitch of small cracks, which greatly improved practicality in plywood factories. I was dissatisfied with this point.

In other words, it is well known that veneers have many back cracks that occur during grinding, but the device applies tensile force from one side of the veneer due to the speed difference between the roller groups. Therefore, as is clear from FIGS. 1 and 2, the sides of the carry-in roller group 1 and the carry-out roller group 2 are separated by
b passes in the opposite direction, the presence of the back crack 3c causes a difference in the progress of the veneer 3, and if a tensile force is applied to the back surface 3b as shown in FIG.
Since the veneer 3 is curved so that the back crack 3c opens, the formation of the small crack 3d is delayed, and the surface 3 as shown in FIG.
Compared to when a is subjected to a tensile force, the pitch and spread (gap) of the small cracks 3d tend to become wider, and as a result, a problem occurs in which the formation state of the small cracks is different. On the other hand, in order to avoid such problems, it is a work at a plywood factory to pass the veneer carefully so that either the front or back side of the veneer is always positioned on the side of each roller group. This will make the process extremely complicated and will cause problems that will hinder the rationalization of the processing process. However, as disclosed in one of the embodiments of the above-mentioned publication, the support roller groups 1a and 2a that support the veneer 3 facing the roller groups 1 and 2, respectively, are Although the above-mentioned problems can be avoided by configuring the drive to be driven in the direction of the dotted arrow at the same speed as the speed, when changing the thickness of the treated veneer or changing the distance between the axes of each roller group, The structure including the corresponding adjustment mechanism etc. becomes extremely complicated, and the adjustment work becomes extremely complicated, resulting in an inconvenience that reduces the practical value in a plywood factory.

The present invention was developed in order to eliminate the drawbacks of the conventional device, and has a front roller that is driven at an appropriate speed and a rear roller that is driven at a slightly higher speed than the front roller. A plurality of veneer support members are arranged facing each other with a somewhat wide interval between them, and are shaped appropriately to support the veneers, so that the veneer supporting members are very close to each other. The front roller and the rear roller are respectively provided oppositely through the passages, and a tensile force is applied to the veneer by the difference in conveyance speed on both the front and back sides of the veneer, and a large number of small cracks are sequentially formed. By making this possible, it is possible to achieve both stability in the formation of small cracks and simplicity of the mechanism, thereby improving practicality in plywood factories.

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

In FIGS. 3 and 4, reference numeral 4 denotes a front roller consisting of a plurality of narrow rollers 4a arranged in parallel at appropriate intervals, and is connected to a drive source such as a motor (not shown) via a main shaft 4b. ), it is driven at an appropriate speed in the direction of the arrow in the figure. Reference numeral 5 denotes a rear roller made up of a plurality of narrow rollers 5a arranged side by side at appropriate intervals, and opposed to the front roller 4 at a distance somewhat wider than the path of the veneer 3. The front roller 4 is driven by a drive source such as a motor (not shown) via the main shaft 5b in the direction of the arrow shown in the figure at a slightly higher speed than the front roller 4. 6 is the shaft 6b due to the action of the spring 6d.
a plurality of arms 6c swinging around the arm 6;
A veneer support member consisting of support rollers 6a etc. which are freely rotatable at the tips of the veneers 3 and 6a, respectively, is moved forward through the path of the veneer 3 so that the positions supporting each veneer 3 are extremely close to each other. The rollers 4 and rear rollers 5 are provided opposite to each other.

The apparatus according to the present invention is configured as described above, for example, and if the veneer 3 is inserted from the front roller 4 side in a direction perpendicular to the fibers, the front roller 4 and the rear roller 5
Due to the speed difference between Of course, it is possible to reliably form small cracks without being significantly affected by changes in the material of the veneer, but if necessary, the speed difference between each roller or the position where the veneer is clamped can be adjusted. By changing the spacing (the spacing between the positions where tensile force is applied), it is possible to change the pitch and spread of small cracks, and it is also possible to apply tensile force by changing the speed difference between the front and back sides of the veneer. Therefore, no matter which roller side the inner cracks inherent in the veneer pass, it is possible to always apply the same tensile force and form small cracks stably. Since only one pair of rollers is driven, the basic structure is significantly simpler than before, and the speed difference between each roller or the single plate can be changed to change the pitch and spread of small cracks as necessary. When changing the spacing between the clamping positions, the configuration of the adjustment mechanism and the adjustment work can be simplified, making it possible to simplify the device including operability. The practical effects of this are extremely large.

As mentioned above, changing the speed difference between the rollers will change the pitch and spread of small cracks, but the larger the speed difference, the narrower the pitch and the wider the spread. In order to actively prevent a decrease in the strength of the veneer in the thickness direction, it is preferable to keep the speed difference to about 20% or less. Furthermore, even if you change the spacing between the positions where each roller and the veneer support member clamp the veneer, the pitch of small cracks will change, and with the same speed difference, the pitch tends to widen as the spacing increases. Considering the elongation rate of the board or the correlation with back cracking, etc., the above-mentioned interval may be approximately equal to or less than 6 times the thickness of the veneer.

Furthermore, the form of each roller is not limited to the form illustrated in FIGS. 3 and 4, and as is clear from FIGS. 5 and 6, for example, the rear roller 7
may be a wide roller that is not symmetrical to the front roller 4, or, for example, as illustrated in FIG. The front roller 9 may be driven through at least one of the support shafts 9b having a flange 9c.
Of course, regardless of the width, if necessary, the outer periphery may be subjected to friction increasing treatment such as rubber coating, and in short, there is no problem as long as the veneer can be transported.

Further, the form of the veneer support member is not limited to the form as illustrated in FIGS. 3 and 4, for example, as illustrated in FIGS. A split sliding type in which a plurality of plate spring-like support bars 8b having a single-plate support surface 8c that engage in a smoother engagement relationship than the engagement relationship with the plate 3 are arranged on the support rod 8a at appropriate intervals. There is no problem even if it is the veneer support member 8 of
As illustrated in the figure, a single-plate support member 6' may be formed by protruding a plurality of protrusions 6e that induce the formation of small cracks on the outer periphery of a support roller 6a. The veneer support member 10 may be made by arranging a plurality of narrow rollers 10a at appropriate intervals on an idling shaft 10b that is pressed in the direction of the rear roller 5. There is no problem as long as it can be supported without blocking the transportation of the material.

As is clear from the above embodiments, the rollers and veneer support members of the apparatus according to the present invention can take various forms, and various modifications other than those shown in the drawings are possible. In order to form small cracks intermittently and uniformly, at least one (preferably three or more) of each roller and veneer support member should have a surface that contacts the veneer parallel to the conveying direction. It is preferable that it is discontinuous in the orthogonal direction, and it is effective if the length is less than 10 times the thickness of the veneer, and if it is discontinuous and the length is less than 6 times the thickness of the veneer, it is effective. more effective. Further, as exemplified in each embodiment, it is effective if the veneer support member is configured to be elastically displaceable, since errors in the thickness direction of the veneer can be absorbed.

[Brief explanation of drawings]

The drawings are for explaining the present invention, and FIGS. 1 and 2 are action explanatory views for explaining the action of the conventional device, FIG. 3 is a plan view of the device according to the present invention, and FIG. 4 is a side view of FIG. 3, FIG. 5 is a plan view of another embodiment of the device according to the present invention, FIG. 6 is a side sectional view of FIG. 5, and FIG. 7 is a side view of the device according to the present invention. It is a side cross-sectional explanatory view of other Examples. 3...Single board, 3c...Back crack, 3d...Small crack, 4, 9...Front roller, 5,7...Rear roller,
6, 6', 8, 10...Single plate support member.

Claims (1)

[Claims] 1. A front roller driven at an appropriate speed and a rear roller driven at a speed slightly faster than the front roller are arranged opposite to each other at a distance slightly wider than the path of the veneer veneer. , a plurality of suitably shaped veneer support members supporting the veneer veneers are connected to the front roller and the rear roller through the path of the veneer veneer in such a state that the positions supporting each veneer veneer are extremely close to each other. The veneer veneer is conveyed in a direction perpendicular to the fibers, and a tensile force is applied to the veneer veneer by the difference in the conveying speed on both the front and back sides of the veneer, and a large number of A veneer veneer tenderizing device characterized by forming small cracks.