JPS595522Y2 - Veneer transfer roller in veneer drying equipment - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a veneer drying device that dries a wide thin veneer by circulating hot air while transporting the veneer using rollers.

Conventionally, veneers obtained by cutting raw wood using veneer lace, etc., always suffer from the so-called curling phenomenon in which the upper surface curves due to stress during cutting, and veneers with partially different moisture content tend to dry out. In the process, cracks in the veneer due to uneven drying shrinkage are inevitable.

Therefore, it is possible to remove these types of molds to make the veneer easier to handle, increase the veneer area by stretching the veneer in a direction perpendicular to the veneer's fibers, and improve the yield. In order to save time, a so-called tenderizing process was used to soften the surface of the veneer by forming fine cracks in the direction parallel to the wood fibers.

These methods include sequentially forming cracks by bending or stretching the veneer with a small radius of curvature using a rotating pressure body such as a roll, or by using a roll with appropriately shaped blades or protrusions formed on the outer circumferential surface. Methods have been adopted to create minute cracks on the entire surface of the veneer while it is being transported, but this method has not yet been perfected.

Regarding publicly known examples of these tenderizing devices, the first one is Japanese Patent Application Laid-open No. 120102/1983, which describes the technology in which a veneer is passed through a roll equipped with a large number of blades on the entire outer periphery, and then tenderized in advance. In the next stage drying equipment, the veneer is held between the top and bottom by a wire mesh with a large number of needles on the surface and transported, while preventing the single plate shrinkage caused by the tendering process. It dries with good yield.

Naturally, therefore, two types of equipment, a tendering device and a drying device, are required, and furthermore, running costs increase due to wear of the needle-like portions provided in the wire mesh, which is extremely uneconomical.

Furthermore, if it is assumed that the tender roll to be pre-processed is installed in the drying device, the device will be compact, but since a piercing member such as a knife is planted all over the outer circumference of the roll, the veneer The pressure required for the piercing member to bite into the roller is enormous, and the roll has to have a larger diameter, so it has little practical value.

Next, considering JP-A No. 49-6107, the present technology has a veneer pressurizing surface coated with an elastic material on the outer peripheral surface of the roll, and sharp blades arranged alternately with the veneer pressurizing surface at appropriate intervals. Tenderizing is performed by feeding the veneer into the roll in a direction perpendicular to the fibers using a tender roll, and the veneer pressure surface of the elastic body prevents the cracking of the veneer caused by the blade. This is to prevent the cracks from propagating, and to limit the cracks in the veneer to a certain size before applying the tendering process. It should be said that this is a unique technique that is based on the condition that the fibers of the veneer are transferred in a direction that is easy to process, that is, in a direction perpendicular to the fibers of the veneer, and it cannot be said to be a universal technique for tender treatment.

Furthermore, if the veneer is dried after the above-mentioned tenderizing treatment, the elongation of the veneer will not be expected to be that great due to drying shrinkage.
In addition, cracks in the veneer occurred one after another, making it difficult to accomplish the purposes of tenderizing described above.

On the other hand, in the drying equipment using the roll conveyance method, which accounts for half of the veneer drying equipment, as a result of seeking economic effects, the frontage is wide, and the structure is configured with multiple stages above and below, and the rollers for transporting the veneer are structurally required. A roller with a relatively small diameter of around 80 mm and a length of around 5 m is used.

With the above configuration, when the veneer is transferred while being sandwiched between the upper and lower rollers, the flexure of the elongated roller has a large effect, making the veneer transfer unsmooth, and the vicinity of the left and right ends of the roller Since the veneer hits the veneer more strongly than the central part of the veneer, problems have been raised, such as depending on the material, the veneer passing through this area may be partially thinned by about 10%.

This invention solves the problem of thinning of the veneer as described above in a roll conveyance type drying device, and focuses on applying tenderizing in a layered manner during the drying process of the veneer. In a plurality of continuously arranged rollers, needle-shaped, blade-shaped, or pointed protrusions are intermittently provided on the outer peripheral surface of one or both of the upper and lower rollers with an appropriate width in the longitudinal direction of the rollers. It is characterized in that the arrangement of one protrusion of each roller is changed and arranged intermittently before and after the plurality of arranged rollers in the veneer transport direction.

An embodiment will be described below with reference to the drawings.

FIG. 1 is a side view of the arrangement of transfer rollers in the veneer drying device, and FIG. 2 is a front view.

P, P', and P'' are veneers that are held between upper and lower transfer rollers and transferred in the direction of the arrow, and are usually in the longitudinal direction of the rollers (the width direction of the drying device).

), the wood fibers are brought into the veneer several times at a time, as shown in FIG. 2, with the direction of the wood fibers aligned with the direction of transport of the veneers.

That is, when the veneer transport means for transporting the veneer within the drying device relies only on rollers arranged at appropriate intervals.

(1) Although the veneer has rigidity in the direction of the fibers, it has physical properties in the direction perpendicular to the fibers, such as brittleness and sagging.

(2) In plywood factories, the length of veneer is gradually reduced with the aim of improving yield, and the length of veneer is gradually reduced, resulting in considerably short veneers (length 200
mm) should also be subjected to drying.

For these reasons, a drying device specified as a roller conveyance type has no choice but to convey the veneer in the direction of the fibers.

In FIGS. 1 and 2, reference numerals 1 and 2 denote pairs of transfer rollers arranged one above the other in the veneer transfer direction (in the longitudinal direction of the drying device).

) are arranged in tandem at appropriate intervals in the required number.

The upper roller 1 is not shown, but depending on the thickness of the veneer veneers p, P', and P'' to be transferred, its bearing part can be moved up and down freely, or the shaft end support part of the bearing can be extended up and down. By forming the roller shaft into a hole, the end portion of the roller shaft is configured to be able to move up and down.

A needle-shaped, blade-shaped, or point-shaped protrusion 4 is arranged on the outer peripheral surface of the roller, and the tip of the protrusion 4 pierces the surface of the veneer to be transferred by an appropriate amount to form a crack.

The protrusion 4 is shaped so that it can be subjected to so-called tenderizing treatment.

The protrusions 4 are disposed intermittently at a plurality of locations with appropriate widths in the longitudinal direction of the roller 1.

The above-mentioned intermittent arrangement of the protrusions has the effect of averaging out the tendering effect caused by the protrusions, as shown in Figures 2 a, l) and 3 a, l); When the rollers 1 are disposed in an intermittent arrangement as shown in FIG. It is constructed in an intermittent manner by interchanging them.

In other words, it is preferable to alternately arrange the interrupted portions of the protrusions 4 of the rollers in accordance with the direction in which the veneer is transported.

Therefore, the veneer portion that did not receive the tendering effect after passing through the upper roller 1 in FIG. become.

Upper rolls 1 and 2 are made of veneer veneer P, P' due to their own weight.
, P" is transferred while being appropriately pressurized, and subjected to drying and tendering. For example, it is more effective to apply a pressing force to the shaft end of the upper roller using another pressing member such as a spring. It is also possible to perform tender processing.

Reference numeral 3 in each figure indicates a lower roller disposed opposite to the upper roller, and although not shown, the bearing portion thereof is usually fixed so as not to be raised or lowered in the vertical direction.

The next most preferred embodiment is shown in FIG.

As shown in Figures 3a and l), the upper roller 1 is provided with a protrusion 4 at approximately 1/3 of the center in the longitudinal direction of the roller, and the next upper roller 2 is provided with a protrusion 4 on each of the left and right axial ends of the roller. This is a configuration in which approximately 1/3 of the projections 4 are provided.

In short, if you try to retender a wide area of a veneer transported by one roller, the deflection of the roller will result in an uneven tenderizing effect', and the retendering will occur over the entire outer circumferential surface of the roller. In the case where the protrusion is provided, not only will the uneven tendering effect due to the above-mentioned deflection due to its own weight occur, but in order to obtain a tendering effect over the entire area, it is necessary to effectively use the veneer with a strong pressing force. As the deflection increases dramatically, it is inevitable that the work becomes extremely large-scale, and good results can be obtained if each successive roller takes over a portion of the tendering process.

In this sense, the tender roller shown in FIG. 3 is preferred.

Next, regarding the arrangement of the rollers, the upper rollers 1 and 2 and the lower roller 3 in FIG. 1 may be arranged upside down, and further, the lower roller 3 in FIG. It is also possible to arrange the upper roller 2 shown in the figure as a lower roller.

As shown in FIGS. 2 and 3, when rollers 3 in which one side of the upper and lower rollers has a flat outer peripheral surface are used, the veneer is ironed by the roller heated by the hot air circulating inside the machine. effect is brought about.

In addition, when the protrusion 4 is sharp and has a shape that makes it easy to penetrate the veneer, and the protrusion is relatively low, the outer peripheral surface of the roller directly heats the veneer and slightly heats the veneer surface when the veneer is actually used. By applying pressure, the above-mentioned ironing effect can also be expected.

The shapes of the projections 4 of the upper and lower rollers may be the same or different, as long as they have the same degree of tendering effect.

In addition, rollers with protrusions may be arranged on all of the transfer rollers of the drying device, or evenly thinned out over the entire area of the drying device, or concentrated in the front or rear half of the drying device. They should be placed appropriately, taking into consideration the characteristics, scale, etc.

As described in detail above, the present invention is a roller conveyance type veneer drying apparatus, by intermittently forming protrusions that can be effectively tenderized on the outer peripheral surface of either the upper or lower conveyor roller, or both. Since the veneer was dry-transported and tenderized at the same time, the veneer was subjected to continuous tenderizing treatment during the transport process from loading to unloading the veneer drying equipment. As mentioned above, the protrusions formed on each roller with an appropriate width (length in the longitudinal direction of the roller) are arranged by alternating the positions of the protrusions in the veneer transport direction. Even if each of the rollers is bent, the veneer is uniformly and continuously repeatedly subjected to an average tender treatment over the entire area, so drying time is shortened and drying shrinkage is alleviated.
Furthermore, various effects such as correcting the veneer type and the reduction in the thickness of the veneer are synergistically produced.

[Brief explanation of the drawing]

Fig. 1 is a side view of the arrangement of the upper and lower transfer rollers in the present invention-embodiment, Fig. 2 a, l) is a front view showing the arrangement of the roller protrusions, and Fig. 3 a, l) is the transfer in another embodiment. FIG. 3 is a front view showing an arrangement of roller protrusions. 1.2...Upper roller, 3...Lower roller, 4...Protrusion, P, P', P''...Single plate.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. In a veneer drying device in which veneers are held and transferred by rollers from above and below, either the upper or lower of the veneer transfer rollers, which are paired up and down and are connected at appropriate intervals. Alternatively, needle-like, blade-like, or point-like protrusions are intermittently arranged on the outer circumferential surfaces of both rollers with appropriate widths, and each of the rollers is A loaf for transferring veneers in a veneer drying device, characterized in that the projections are alternately arranged and disposed intermittently. 2. A veneer transfer roller in a veneer drying apparatus according to claim 1, wherein the upper roller of the upper and lower pair of transfer rollers presses the veneer using a pressure member. 3. The veneer transporting roller in a veneer drying apparatus according to claim 2, wherein the pressure member of the upper roller is constituted by a spring.