JPH0367002B2 - - 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 with this.

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 is designed to apply tensile force from one side of the veneer due to the speed difference between the roller groups. Therefore, as is clear from FIG. 1 and FIG.
If a and the back surface 3b pass in the opposite direction, there will be a difference in the progress of the veneer 3 due to the existence of the back crack 3c, 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 veneer 3c is open, the formation of the small cracks 3d is delayed, and the small cracks 3d are inevitably narrower and wider ( There is a tendency for the gap (gap) to become wider, resulting in a problem in which the state of formation of small cracks differs.

On the other hand, in order to avoid the above-mentioned problems, it is a common practice in plywood factories 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 makes the work extremely complicated and causes inconveniences that impede rationalization of the processing process. However, as disclosed in one of the embodiments of the above publication, each of the roller groups 1 and 2
If the supporting roller groups 1a and 2a, which support the veneer 3 in opposition to each other, are configured to be driven in the direction of the dotted line arrow at the same speed as the respective roller groups 1 and 2, the above-mentioned problems can be avoided. However, on the other hand, when changing the thickness of the treated veneer or changing the distance between the axes of each roller group, the configuration including the adjustment mechanism etc. becomes extremely complicated, and the adjustment is difficult. The drawback is that the work becomes extremely complicated, and the practical value of the plywood factory is reduced.

The present invention was developed to eliminate the drawbacks of the conventional device, and has a support roller that is driven at an appropriate speed and an outer periphery that engages the veneer more firmly than the support roller. A pressure roller which is driven at a somewhat faster speed or a somewhat slower speed is provided oppositely through a single plate passage, and
A veneer pressing member of an appropriately shaped shape that presses the veneer against the support roller is placed on the upper side of the pressing roller in the conveying direction when the speed of the pressing roller is fast, and on the other hand, when the speed of the pressing roller is slow, the veneer pressing member is placed on the upper side of the pressing roller in the conveying direction. In preparation for a situation in which the position of the veneer pressing member that presses the veneer is extremely close to the position of each roller that clamps the veneer, the conveyance speed on both the front and back sides of the veneer should be adjusted. Applying tensile force to the veneer by the difference,
By making it possible to form a large number of small cracks in sequence, it is possible to achieve both stability in small crack formation and simplicity of the mechanism, thereby improving practicality in plywood factories. be.

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 wide support roller, which is driven at an appropriate speed in the direction of the arrow shown in the figures by a drive source (not shown) such as a motor. Reference numeral 5 denotes a pressure roller consisting of a plurality of narrow rollers 5b whose outer peripheries are coated with rubber 5c so as to engage the veneer 3 more firmly than the support rollers 4, and arranged in parallel at appropriate intervals. It is disposed opposite to the support roller 4 through a passage in the plate 3, and is driven by a drive source such as a motor (not shown) via a main shaft 5a in the direction of the arrow shown in the figure at a somewhat faster speed than the support roller 4. Reference numeral 6 denotes a veneer pressing member consisting of a plurality of arms 6c that slide around a shaft 6b by the action of a spring 6d, and pressing rollers 6a provided freely rotatably at the tips of the arms 6c. The pressing roller 5 is provided on the downstream side in the conveyance direction so that the position where the rollers 4 and 5 press the veneer 3 is very close to the position where the veneer 3 is held between the rollers 4 and 5.

The device according to the present invention is configured as described above, for example, and when the veneer 3 is inserted from the side of the veneer pressing member 6 in a direction perpendicular to the fibers, the support roller 4 is placed at the position where it is pressed by the pressing roller 6a. Since the pressure roller 5 engages the veneer 3 more firmly than the support roller 4 at the position where it is clamped by the pressure roller 5, the veneer 3 is conveyed at the speed of the pressure roller 5. As a result, a tensile force is applied to the veneer 3 due to the speed difference, and a large number of small cracks 3d are sequentially formed.

Furthermore, since the magnitude and application position of the tensile force due to the speed difference are almost constant, it goes without saying that small cracks can be reliably formed without being significantly affected by changes in the material of the veneer. If necessary, the speed difference between each roller or the distance between the position where the veneer pressing member presses the veneer and the position where each roller clamps the veneer (the distance between the positions where tensile force is applied) )
It is also possible to change the pitch and spread of small cracks by changing the No matter which roller the underlying crack passes through, the same tensile force can always be applied to form small cracks stably, and since only one pair of rollers is driven, The basic configuration is significantly simpler than the conventional one, and it is possible to change the speed difference between each roller or the interval between the positions where tensile force is applied in order to change the pitch and spread of small cracks as necessary. The configuration of the adjustment mechanism and the adjustment work can be based on the support roller, which is a single member on one side of the veneer, making the operation much simpler than before. This makes it possible to simplify the equipment, including the functionality, and the practical effects of the present invention in plywood factories are extremely large.

In the embodiment illustrated in FIGS. 5 and 6, a narrow roller 7b has a large number of small protrusions 7c protruding from the outer periphery so as to engage the veneer 3 more firmly than the support roller 4.
are arranged in parallel at appropriate intervals, and the main shaft 7
This device uses a pressure roller 7 that is driven in the direction of the arrow shown in the figure at a speed slightly slower than that of the support roller 4 by a drive source such as a motor (not shown) via a, and the speed of the pressure roller 7 is lower than that of the support roller 4 Since the speed is slower than the speed of the veneer pressing member 6, the pressing roller 7
It is provided on the downstream side in the conveyance direction.

Even in the device configured as described above, at the position where the pressure roller 7 is clamped, the pressure roller 7 engages with the veneer 3 more firmly than the support roller 4.
The veneer 3 is transported at the speed of the pressure roller 7 and at the speed of the support roller 4 at the position where it is pressed by the pressure roller 6a, and the tension force is applied to the veneer 3 due to the speed difference. As a result, a large number of small cracks 3d are sequentially formed.

As is clear from the above embodiments, the device according to the present invention sequentially applies tensile force to the veneer using the speed difference between the support roller and the pressure roller on both the front and back surfaces of the veneer. No matter which roller side the inner cracks in the veneer pass, the same tensile force is always applied to form small cracks in a stable manner. So,
There is no need to be careful to ensure that either the front or back side of the veneer is always on the same side, and there is no need to worry about hindering the rationalization of the processing process.

As mentioned above, changing the speed difference between each roller will change the pitch and spread of small cracks, but generally speaking, 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. Also, even if you change the spacing between the positions where tensile force is applied, the pitch of small cracks will change, and with the same speed difference, the pitch tends to widen as the spacing becomes wider. Considering the correlation, etc., the distance may be approximately equal to or less than six times the thickness of the veneer.

Further, the form of the support roller is not limited to the forms exemplified in the above-mentioned embodiments, and although not shown in the drawings, for example, it may have a form in which a large number of grooves are formed on the outer periphery, or as necessary. Depending on the situation, the outer periphery may be subjected to a friction resistance treatment such as plating or synthetic resin coating.

Further, the shape of the pressing roller is not limited to the shapes illustrated in the above embodiments, but for example, as illustrated in FIG.
Even if the pressure roller 9 is entirely covered with rubber 9a on the outer periphery, or, although not shown, a plurality of narrow rollers arranged in parallel at appropriate intervals may be brought into contact with the outer periphery. There is no problem even if it is driven through an appropriate number of support shafts.
In short, any form may be used as long as it has an outer periphery that engages with the veneer more firmly than the support roller.

Furthermore, the form of the veneer pressing member is not limited to the forms exemplified in the above two embodiments.
As illustrated in the figure, even if it is a veneer pressing member 6' having a large number of small protrusions 6e protruding from the outer periphery of a pressing roller 6a to induce the formation of small cracks 3d, or as illustrated in FIG. This is a split sliding type veneer press in which a plurality of plate spring-like press bars 8b having a veneer press surface 8c that is smoother than the outer periphery of the support roller 4 are arranged on the support rod 8a at appropriate intervals. In the case of member 8, although not shown, a plurality of narrow rollers arranged in parallel at appropriate intervals can be freely rotated by an appropriate number of support shafts arranged around the outer periphery of the rollers. There is no problem even if it is in a form in which it is supported, and in short, it can be in any form as long as it can be pressed so that the veneer at the pressing position is conveyed at the speed of the support roller.

As is clear from the above, each roller and the veneer pressing member of the device according to the present invention can be implemented in various forms, but in any case, the pressing roller and the veneer pressing member can be elastically displaced. This is convenient because it can absorb errors in the thickness direction of the veneer, and it also prevents the veneer from tearing by forming small cracks intermittently and uniformly in the fiber direction of the veneer. It is desirable that the surface of at least one of the pressing roller or the veneer pressing member that contacts the veneer is discontinuous in the direction orthogonal to the conveyance direction, and in the embodiments illustrated in FIGS. 3 to 7. In both cases, it is effective if the surfaces that come into contact with the veneer are discontinuous and alternately shifted in the direction orthogonal to the conveying direction. In addition, the small projections provided on the pressure roller or the veneer pressing member have the property of inducing the formation of small cracks, so they are effective in discontinuing, uniformizing, and standardizing small cracks. The shape of the body is preferably a shape that does not easily damage the veneer, and the pitch at which the body is arranged is desirably selected as appropriate depending on the purpose of the treatment.

[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 explanatory diagram of another embodiment of the device according to the present invention, FIG. 6 is a side view of FIG. 5, and FIGS. 7 and 8 are views of the present invention. It is a side explanatory view of another Example of the apparatus based on FIG. 3...Single plate, 3c...Back crack, 3d...Small crack, 4...Support roller, 5, 7, 9...Press roller, 6, 8...Single plate pressing member.

Claims (1)

[Claims] 1 a support roller driven at an appropriate speed;
A pressure roller, which has an outer periphery that engages the veneer veneer more firmly than the support roller, and is driven at a speed somewhat faster or slower than the support roller, is inserted through the path of the veneer veneer. At the same time, a veneer pressing member of an appropriate shape for pressing the veneer veneer against the support roller is placed on the upper side of the pressing roller in the conveyance direction when the speed of the pressing roller is fast, or on the upper side in the conveying direction of the pressing roller when the speed of the pressing roller is slow. In this case, the pressure roller is provided on the lower side in the conveyance direction so that the position where the veneer veneer is pressed is extremely close to the position where the veneer veneer is clamped by each of the rollers, and the veneer veneer is moved in the direction orthogonal to the fibers. Tenderizing of a veneer veneer characterized by applying tensile force to the veneer veneer by applying a tensile force to the veneer veneer by varying the conveyance speed between the front and back sides while conveying the veneer, thereby sequentially forming a large number of small cracks. Device.