JP2013220624A - Dehydration method for veneer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress degradation in dehydration effects due to the occurrence of crack in a veneer caused by extension of a veneer front end part in a width direction (direction orthogonal to a fiber direction) when the veneer is dehydrated using a pair of rolls.SOLUTION: A veneer 5 is passed between a pair of a lower roll 1 and an upper roll 3 in a length direction (the same direction with a fiber direction) and then compressed in the thickness direction to be dehydrated. In this case, even if the upper roll 3 arranged in an ascendable and descendible manner is lowered to an operation position which is shown by a solid line and away from the lower roll 1 by a prescribe interval G1 much narrower than the thickness T of the veneer, the upper roll 3 is kept to be elevated to a stand-by position which is shown by a dotted line and away from the lower roll 1 by an arbitrary interval G equal to or larger than the thickness T of the veneer until a region of the veneer 5 at a suitable distance L from the front end is not compressed any more, so that compression is temporarily stopped. After the veneer 5 is passed up to a position where the region is not compressed, an operation member 8 is placed in operation to lower the upper roll 3 to the operation position shown by the solid line, and suitable compression is started.

Description

  The present invention relates to an improvement in a method for dewatering a veneer veneer.

  Conventionally, when drying veneer veneers (hereinafter simply referred to as veneers) used to manufacture plywood and veneer laminates, various heating means are used for relatively thick veneers from the beginning. If the main point is to heat-dry the veneer, enormous heating energy is required and the cost increases. For example, as disclosed in Patent Document 1, Patent Document 2, etc., the thickness of the veneer Contain a veneer by compressing in the thickness direction through a veneer between a pair of rolls, which are provided so as to be spaced apart at a significantly narrower distance than each other and at least one of the pair is rotatably driven. Many techniques for mechanically dehydrating moisture have been proposed.

  Thus, to describe the outline of a specific form of the pair of rolls, first, as an aspect related to the material of the roll, both aspects are made of total metal, or one is made of total metal, The other is a composite in which the outer periphery of the metal shaft portion is coated with a rubber having an appropriate thickness in a cylindrical shape, or both have a cylindrical shape with an appropriate thickness of rubber on the outer periphery of the metal shaft portion. As a typical example, the aspect of the composite formed by coating on the surface of the roll, and the aspect related to the shape of the peripheral surface of the roll has no irregularities on the peripheral surface of at least one of the rolls. A smooth surface shape, or at least one of the peripheral surfaces of one of the rolls, metal protrusions having a suitable shape (wedge shape, pyramid shape, ring shape with a triangular cross section, etc.), dispersed or axial Multiple rows or discontinuities in the circumferential direction at appropriate intervals in the core direction An aspect in which it is arranged in the form of a screw thread or the like, or a narrow groove that allows local deformation of rubber accompanying pressure contact with a single plate on the peripheral surface of at least one of the composite rolls in the axial direction A typical example is an aspect formed by drilling in a plurality of rows that are continuous in the circumferential direction at appropriate intervals. Further, as an aspect relating to the support method of the roll, at least one of the rolls is provided. A mode in which it is rotatably supported only at both ends, or at least one of the rolls is provided with a groove for a support member continuous in the circumferential direction in the middle of the roll, and an intermediate in the groove for the support member An embodiment in which a support member is interposed and supported at both ends and an intermediate portion, or as in the latest technology according to the most recent application (Japanese Patent Application No. 2012-85531) of the present applicant, , And divided into multiple narrow rolls The narrow rolls can be individually rotated via a support mechanism including a bearing, a support pin, a support member, a holding member, etc., and can be separated and accessed with respect to the drive roll on the other side of the pair. A typical example is a mode in which each narrow roll is pressed toward the drive roll with an appropriate pressing force by using an operating mechanism including a fluid cylinder or the like. As is well known, the veneer is a unique material having a remarkable anisotropy of the tissue structure. Therefore, as an aspect when the veneer is passed between a pair of rolls, the width direction (the direction perpendicular to the fiber direction) ) In the length direction (the same direction as the fiber direction) is more suitable for dehydration because of the arrangement of the cell tissue.

Japanese Patent No. 3790311 Japanese Patent No. 4859307

  However, according to the mode in which the single plate is passed in the length direction between a pair of rolls that are arranged to be separated by a significantly narrower distance than the thickness of the single plate, the front end of the single plate is sandwiched between the pair of rolls. As the sheet is compressed in the thickness direction, a phenomenon occurs in which the vicinity of the front end of the single plate extends in the width direction according to anisotropy. That is, the anisotropy peculiar to the veneer whose bonding strength in the width direction is extremely soft is the cause of the elongation. More specifically, the front end of the veneer is substantially parallel to the axial direction of the roll. In the case of being sandwiched between, the vicinity of the left and right sides mainly on the front end side of the single plate tends to be extended in the width direction, and the amount of extension tends to be relatively small. When sandwiched somewhat obliquely with respect to the direction, since the extension is forwarded from the side sandwiched first, toward the side sandwiched from the rear, the front end side of the single plate is entirely Although it tends to be stretched in the width direction and the amount of elongation tends to be relatively large, in any case, when the phenomenon of stretching in the width direction occurs from the beginning on the front end side of the veneer, for example, the elongation The resulting fine cracks are near the left and right sides of the front end of the veneer or the entire width of the front end of the veneer. For example, or the compressibility in the thickness direction of the single plate is reduced in the vicinity of the left and right side portions on the front end side of the single plate or the entire width on the front end side of the single plate. Will be. And once the elongation in the width direction occurs at the front end of the veneer, the generated elongation itself is added as a secondary incentive, so that the same applies to the part following the front end. Therefore, problems such as the occurrence of fine cracks and a decrease in the compressibility in the thickness direction are also spillovered over the entire length of the veneer.

  Thus, when fine cracks occur over the entire length of the veneer, the water to be dehydrated by compressing the veneer is easy to flow into the fine cracked part, so the dehydration effect is not reduced significantly. In addition to the inconvenience that occurs, fine cracks are enlarged due to drying shrinkage and the like in the subsequent heating and drying process, and the quality and yield of the veneer are likely to deteriorate. Even if no cracks occur, if the compressibility in the thickness direction of the veneer decreases due to at least a part of the veneer extending in the width direction, there is a disadvantage that the dewatering effect of the corresponding portion is reduced.

  The present invention has been developed to eliminate or greatly reduce the problems of the prior art. Specifically, the present invention is provided so as to be opposed to each other at a desired interval that is significantly narrower than the thickness of a single plate. And a single plate is passed between the pair of rolls in the length direction and compressed in the thickness direction so that at least one of the pair can be driven to rotate. A dehydrating method for performing dehydration in an automatic manner, wherein at least one of a pair of rolls is provided so as to be able to be separated and approached with respect to the other roll, and the roll provided with this operation is provided with respect to the other roll. An operating mechanism for alternately separating and approaching a standby position at an interval equal to or greater than the thickness of the plate and an operating position at the desired interval, wherein at least the front end side of the single plate is the pair of rolls When passing between the pair of rods, Even if it is assumed that the belt is close to the desired interval, the operable roll is separated from the standby position until the portion separated by an appropriate distance from the front end of the veneer is not compressed. The compression is paused for a while, and after passing the single plate to a position where the part is not compressed, the operable roll is brought close to the operating position via the operating member, and the desired compression is started. In the same manner as the single plate dewatering method (Claim 1), the single plate is passed in the length direction between a pair of rolls facing each other at a desired interval significantly narrower than the thickness of the single plate. A dehydration method in which the moisture contained in a veneer is mechanically dehydrated by compressing in a direction, and at least one of a pair of rolls is provided so as to be able to be separated and approached with respect to the other roll. The other roll An operation for alternately separating and approaching the roll to a separation limit position having a predetermined interval wider than the desired interval and slightly narrower than the thickness of the single plate and to an operation position having the desired interval. When a mechanism is provided and at least the front end side of a single plate is passed between the pair of rolls, even if it is assumed that the pair of rolls are close to the desired distance, an appropriate distance from the front end of the single plate Until the part that is far away is not compressed excessively, the operable roll is separated to the separation limit position to reduce the compression for a while, and the veneer is moved to a position where the part is not excessively compressed. If it passes, the dewatering method (Claim 2) of the board | plate characterized by approaching the actuable roll to the said operation position via an operation member, and starting compression as desired is carried out. As invention To propose.

  Further, in addition to the basic invention, also in the case where the rear end side of the single plate passes between the pair of rolls, the portion that is appropriately separated from the last end of the single plate is larger than the thickness of the single plate. When it reaches the position where it is pressed against each roll in the operation position with a significantly narrow desired interval, the operable roll is made at least equal to or more than the thickness of the single plate with respect to the other roll through the operation mechanism. At a predetermined interval, or at a predetermined separation interval that is wider than the desired interval and slightly smaller than the thickness of the veneer, and stops the desired compression, or The method of claim 1 or claim 2, wherein only one of the pair of rolls is provided so that it can be separated and approached with respect to the other roll. Claim 1 or Claim 2 or Claim 3 The single-plate dewatering method (Claim 4) and the pair of rolls are both provided so as to be capable of separating and approaching the other roll. A plate dewatering method (Claim 5) is proposed as an accompanying invention.

  According to the dehydration method of the first aspect, in the range from the foremost end of the veneer to a portion that is appropriately spaced apart, the compression by the pair of rolls is temporarily suspended, so that the phenomenon of extending in the width direction In any part of the front end portion of the single plate, the occurrence of defects such as fine cracks due to elongation and a decrease in the compressibility in the thickness direction is eliminated. In addition, if the occurrence of elongation to the part separated from the foremost end of the veneer by an appropriate distance is suppressed, immediately after that, even if the compression by the pair of rolls to the part following the part is started, the compression is started. In addition to the occurrence of new elongation due to the occurrence of, the occurrence of new elongation, which is the secondary cause of the generated elongation itself, is suppressed or greatly suppressed, so the occurrence of fine cracks and thickness Induction of problems such as a decrease in the compression rate in the direction will be eliminated or greatly reduced over almost the entire length of the veneer. Inconveniences such as the quality of the single plate and the deterioration of the yield due to the expansion of the size are eliminated or greatly reduced.

  By the way, according to the dehydration method as described above, the water content of the front end of the veneer is higher than the water content of other parts because the desired dehydration process is not performed on the front end of the veneer. However, as is well known, the end of the veneer (particularly the end in the length direction) corresponds to the outlet of the main passage of steam generated by heating, regardless of the heating method, or hot air heating. In the case of the formula, because it is the part that is dried the earliest due to the large heat receiving area, etc., even if the moisture content before drying is higher than the moisture content of other parts, other parts Compared to the above, there is no risk that the drying will be significantly delayed. By delaying, the rest of the whole except for the rear end of the veneer is finally almost uniform. In some cases, the moisture content of the front end of the veneer is intentionally left more than the moisture content of other parts. In the process of finishing to the final product, the area around the four circumferences of the board is the part that will be cut off entirely or in large part, so any difference in the dry state will not be an obstacle. There is no possibility that a difference in the dry state will cause a practical problem later.

  In addition, in order to stably prevent the occurrence of elongation in the width direction at the front end portion of the single plate due to compression by the pair of rolls, from the front end of the single plate, as in the dewatering method according to claim 1. Although it is effective to completely stop the compression in the range up to a site separated by an appropriate distance, as is well known, a veneer is a material that is slightly elastic in the thickness direction, However, since the elastic range tends to increase in proportion to the thickness, when a relatively thick veneer is dewatered, compression at the front end of the veneer is performed as in the dewatering method according to claim 2. Even if the compression is not temporarily stopped and the compression is reduced for a while, it is correspondingly effective in suppressing the occurrence of the front end of the veneer in the width direction, and naturally, compression by a pair of rolls is started. After that, it is also effective for suppressing the elongation of the part following the front end of the veneer. Over substantially the entire length of the plate, occurrence prevention and fine cracks, to reduction prevention or the like of the dewatering effect, is a correspondingly effective.

  Further, in order to prevent the occurrence of fine cracks over almost the entire length of the veneer and to prevent the reduction of the dehydration effect, as in the dehydration method according to claim 1 or claim 2 described above, on the front end side of the veneer, It is sufficient to temporarily stop or reduce the compression for a while. However, as in the dewatering method according to claim 3, the compression is temporarily stopped or reduced even at the rear end side of the veneer. If this is done, the occurrence of cracks on the rear end side, which tends to be longer in length and spread than the cracks on the front end side, can also be suppressed, which is more effective. That is, even in the conventional method, on the front end side, when the expansion in the width direction occurs due to the compression by the pair of rolls, the portion of the subsequent single plate that has not yet been compressed is stretched. Since it acts to suppress the occurrence, it is fine even if cracking occurs, but in the vicinity of the rear end, there is no subsequent part that suppresses the occurrence of elongation, so the elongation further increases. Due to the tendency, the length and spread of the generated cracks are likely to increase, and the probability of the cracks expanding in the subsequent heating and drying process and the probability of the cracks expanding due to manual handling increase. However, according to the dewatering method according to claim 3, such a fear is eliminated, and in addition to the front end of the single plate, the rear end of the single plate can be dehydrated. , Pause, or if greatly reduced, veneer front edge and veneer Initial drying of the end, by the more delayed than the initial drying of the remaining part, finally, etc. sometimes dry state of the entire veneer is generally equalized, it is more effective.

  Thus, in order to temporarily stop or reduce compression locally at least on the front end side of the veneer, as in the dehydration method according to claim 4, one of the pair of rolls is used. However, if necessary, both the pair of rolls can be connected to the other roll as in the dehydration method according to claim 5. There is no problem even if it adopts a configuration that can be separated and approached, in the case of adopting this configuration, in addition to the operation mode in which both rolls are operated together, for example, the operation distance is set to be different for each roll, On the front end side, only the other roll with a smaller working distance is operated to reduce the compression for a while, and on the rear end side, only one roll with a larger working distance is set. By activating, the compression is completely paused Operating mode that causes also a simple feasible.

  In addition, when adopting a configuration in which a pair of rolls are positioned at a position spaced apart from the thickness of the single plate by a desired distance from the beginning, as in the conventional method, for example, a single plate having a node at the tip is used. When passing through, the nodes cannot be easily compressed to the same thickness as the desired interval, so the tip of the single plate cannot be smoothly fed (engaged). However, it is easy to cause a problem that the node rotates around the node or the processing of the veneer is delayed. However, according to the dehydration method of the present invention, the veneer is a veneer having a node at the tip. However, since reliable feeding can always be performed, there is another effect that the possibility of occurrence of such a problem is eliminated.

It is a schematic side explanatory drawing of the dehydration apparatus used for implementation of the present invention. It is side surface explanatory drawing of the Example of the dehydration method which concerns on this invention. It is side surface explanatory drawing of the Example of the dehydration method which concerns on this invention. It is a schematic side explanatory drawing of the example of a change of the dehydrating apparatus used for implementation of this invention. It is a schematic side surface explanatory drawing of another modified example of the dehydrating apparatus used for carrying out the present invention. It is side surface process explanatory drawing of the Example from which the dehydration method which concerns on this invention differs. It is side surface process explanatory drawing of the Example from which the dehydration method which concerns on this invention differs. It is side surface process explanatory drawing of the Example from which the dehydration method which concerns on this invention differs. It is side surface process explanatory drawing of another Example of the spin-drying | dehydration method which concerns on this invention. It is side surface process explanatory drawing of another Example of the spin-drying | dehydration method which concerns on this invention.

  Hereinafter, the present invention will be described in further detail together with an example illustrated in the drawings, but an operation member for operating each device constituting a dehydrating apparatus used for implementing the present invention, and a control mechanism for controlling the operation of the operation member. Therefore, it is possible to set a device that can perform a desired function without any difficulty without any difficulty without using a specially-special embodiment. Therefore, the illustration including the control system (control circuit) is omitted for the sake of simplifying the drawing and making it easy to see. Moreover, although all the illustrated embodiments are examples in which the front end of the single plate is sandwiched in a state substantially parallel to the axial direction of the roll, it is assumed that the front end of the single plate is in the axial direction of the roll. However, even if it is sandwiched in a somewhat oblique state, there is no great difference as a side process explanatory diagram, and there is no possibility that a difference that impedes practically will occur in terms of functions and effects to be achieved.

FIG. 1 is a schematic side view of a dehydrating apparatus used for carrying out the present invention, and FIGS. 2 and 3 are side process explanatory views of an embodiment of a dehydrating method according to the present invention. In the figure, reference numeral 1 denotes a lower roll formed by fixing a rubber 1b having an appropriate thickness on the outer periphery of a metal shaft portion 1a in a cylindrical shape. It is fixed to a stand or the like, and is always (or at any time) driven to rotate in the direction of the arrow through a drive source (not shown) such as a motor with a speed reducer, in cooperation with the upper roll 3 described later, In the process of feeding the veneer 5 in the length direction (the same direction as the fiber direction), the veneer 5 is compressed in the thickness direction, and moisture contained in the veneer 5 is removed from the front and back surfaces of the veneer 5. And squeezed out to the rear end face through the gap inside the veneer.
Although not shown in the drawings as necessary, an annular narrow groove having an appropriate depth and an appropriate width is provided at appropriate intervals in the axial direction in the rubber portion. A function of easily allowing local deformation of the rubber accompanying the press contact with the single plate may be added by the plurality of rows of narrow grooves.

Reference numeral 3 denotes an all-metal upper roll, which is fitted in the frame 6 so as to be moved up and down through a bearing box 4 incorporating a bearing such as a bearing and provided with a guide portion 4a. Through a working mechanism 8 to be described later, the stand-by position indicated by the solid line and the actuating position indicated by the dotted line can be raised and lowered alternately at appropriate times, and the single plate 5 is completely compressed at the stand-by position. In the process of feeding the veneer 5 in the length direction in cooperation with the lower roll 1 when the veneer 5 is allowed to pass through and is lowered to the operating position. The plate 5 is compressed in the thickness direction, and the moisture contained in the single plate 5 is squeezed out to the rear end surface through the front and back surfaces of the single plate 5 and the gap inside the single plate.
Although not shown in the drawings, if necessary, metal protrusions having a suitable shape (wedge shape, pyramid shape, ring shape with a triangular cross section, etc.) are dispersed or axially arranged on the peripheral surface of the upper roll. It is arranged in a plurality of rows or discontinuous thread shapes that are continuous in the circumferential direction at appropriate intervals in the direction, and the protrusion of the protrusion accompanying the pressure contact with the single plate causes the single plate to move in the width direction. There is no problem even if the compression function (local compression function) is also used to promote dehydration.

8 is an operating mechanism consisting of a fluid cylinder or the like indirectly connected to the upper roll 3 via the bearing box 4, which is fixed to the frame 6, and when desired, via the bearing box 4, The upper roll 3 is alternately raised and lowered in the direction of the arrow in the figure. When the upper roll 3 is lowered from the standby position to the operating position, the distance between the upper roll 3 and the lower roll 1 is the thickness T of the single plate. When the frame 6 is provided with a stopper 7 so that the desired gap G1 is significantly narrower than that, and the upper roll 3 is raised from the operating position to the standby position, the upper roll 3 and the lower roll 1 The process length of the actuating mechanism 8 is adjusted so that the distance between the two is equal to or larger than the thickness T of the single plate.
The desired interval G1 is an interval directly related to the dehydration function, and it is important to make it significantly narrower than the thickness T of the single plate in order to achieve the required dehydration action. If it is not 70% or less of the thickness T, the dehydration action is insufficient, and it is practical to set it to 60% or less of the thickness T of the veneer. The fact that the action is further promoted has been reconfirmed in experiments in the development process of the present invention, and is consistent with the known results. Therefore, in the present invention, numerical values in such a range can be applied. Although it is adopted as a guideline of the numerical value, excessive compression is not allowed because it may significantly damage the plasticity of the veneer structure and cause excessive thickness reduction of the veneer, and the maximum compression limit value is In order to correspond to the properties of the single plate to be processed, the form of a pair of rolls, etc., based on experiments only Stipulated is desirable.
On the other hand, the arbitrary gap G is not limited as long as it is equal to or greater than the thickness T of the single plate. However, if it is excessively wide, there is a possibility that the quick response of the upper roll 3 is lowered. Equivalent to T or slightly less than the thickness T of the single plate (for example, about 2 mm or less, or, for example, when a protrusion is disposed on the peripheral surface of the upper roll, the protrusion is inserted into the single plate shallowly. It is practical that the upper row is widened only to the extent that the upper row is driven to rotate.

  9 and 9a are single plate guides arranged on the inlet side and the outlet side of the pair of lower roll 1 and upper roll 3, respectively. Guide the vehicle so that it can pass through the facing space.

  The dehydrating method according to the present invention can be carried out using a dehydrating apparatus configured as described above, for example. Before passing the veneer 5, the upper roll 3 Is made to wait at a standby position indicated by a solid line in FIG. Even if it is assumed that the upper roll 3 has been lowered to the operating position, a portion separated from the foremost end of the single plate 5 by an appropriate distance (a distance indicated by a symbol L in FIG. 3) is not compressed. As illustrated in FIG. 2, when the upper roll 3 is kept in the standby position and the single plate 5 is passed to a position where the portion is not compressed, the operating mechanism 8 is illustrated in FIG. Then, the upper roll 3 is lowered to the operating position, and thereafter the upper roll 3 is kept lowered to the operating position until the rear end of the single plate 5 passes, and the single plate 5 is moved as desired. When the final end of the veneer 5 passes, the upper roll 3 is again raised to the standby position indicated by the solid line in FIG.

  Hereinafter, by repeating the same operation, dehydration treatment can be performed one after another through the veneer 5. However, according to the dehydration method as described above, the process from the front end of the veneer 5 to an appropriate distance is achieved. In the range, the compression by the lower roll 1 and the upper roll 3 is temporarily stopped, so that the phenomenon that the veneer 5 extends in the width direction does not occur, and any portion of the front end portion of the veneer does not occur. Induction of defects such as fine cracks due to elongation and a decrease in the compressibility in the thickness direction is eliminated. And if the generation | occurrence | production of the extension to the site | part which left | separated the appropriate distance from the foremost end of the veneer 5 is suppressed immediately after that, the compression by the lower roll 1 and the upper roll 3 to the part following the said site | part will be carried out. Even if it is started, the generation of new elongation caused by the generated elongation itself as well as the generation of new elongation due to compression is suppressed or greatly suppressed, so fine cracks are generated. And the induction of defects such as a decrease in the compressibility in the thickness direction can be eliminated or greatly reduced over the entire length of the veneer 5, and the dehydration effect is naturally reduced. Inconveniences such as deterioration of the quality and yield of the veneer 5 due to enlargement of cracks and the like are also eliminated or greatly reduced.

  Incidentally, the recommended value of the distance for temporarily stopping the compression to the front end of the veneer indicated by the symbol L in FIG. 3 is an experiment in order to correspond to the properties of the veneer, the form of a pair of rolls, etc. However, it is preferable to set the value based on the above, but as a guideline, about 1 mm to 15 mm is appropriate, and about 3 mm to 10 mm is more preferable. Temporarily, the front end of the single plate is in the axial direction of the pair of rolls. When there is a possibility of being sandwiched in a somewhat slanted state, it is preferable to adjust the distance from the front end on the side where the passage is delayed to the recommended value.

  Thus, as described above, after passing through a portion separated from the foremost end of the single plate 5 to the required position, the upper roll 3 is lowered to the operating position, and the single roll 5 is moved to the single plate 5 by the rolls 1 and 3. Although an illustration is omitted as an example of a more specific means for appropriately performing a series of operations of starting the compression of the single plate 5, the single plate 5 is provided on the upper surface of the single plate guide 9 on the inlet side, for example. A mark indicating the position of the rear end of the veneer 5 (for example, a straight line extending in the width direction of the veneer) is drawn, and the mark and the rear end of the veneer 5 are A means for manually moving the single plate 5 through the dehydrating device to the matching position and then pressing a start switch such as a foot switch to operate the operating mechanism 8 and lower the upper roll 3 to the operating position. If necessary, pass the front edge of the veneer through the dehydrator. For a limited period of time, the driving of the lower roll 1 may be stopped for a while and restarted in conjunction with the lowering of the upper roll 3, and if necessary, a series of operations may be performed as described later. It is also possible to adopt a configuration that automatically performs the above.

  That is, for example, as illustrated in FIG. 4, a pair of auxiliary feed rolls in which at least one of the rolls 1 and 3 can be driven to rotate at the same speed as the lower roll 1 at the front of the rolls 1 and 3. 10.10a and 1 to 2 single plate detectors 11 are arranged respectively (in the case of one, the central portion in the width direction of the single plate, in the case of two, in the width direction of the single plate) It is suitable to be arranged in the vicinity of both ends), and the front end of the single plate 5 by the single plate detector 11 (when two single plate detectors are provided, the side of the passage delayed) The operation is performed after the passage of the front end of the veneer 5 is delayed by a delay time sufficient for the front end of the single plate 5 to reach the required position in accordance with the driving speed of the auxiliary feed rolls 10 and 10a. If the mechanism 8 is operated and a means for lowering the upper roll 3 to the operating position is adopted, a series of movements are performed. It can be carried out automatically.

  Further, in order to stably prevent the occurrence of elongation in the width direction at the front end of the single plate due to the compression by the pair of rolls, as in the embodiment illustrated in FIGS. Although it is effective to completely stop the compression in the range from the front end to an appropriate distance, as will be described later, the compression at the front end of the single plate is not completely stopped and the compression is not performed. Even if it is reduced for a while, it is effective accordingly.

That is, for example, as illustrated in FIG. 5, instead of the standby position indicated by the solid line in the dehydrating apparatus illustrated in FIG. 4, the interval between the lower roll 1 and the upper roll 3 is wider than the desired interval G1. In addition, another stopper 13 is attached to the operating member 8 so that the upper limit position of the upper roll 3 is determined at a position where the predetermined interval G2 is slightly narrower than the thickness T of the single plate, thereby constituting a dehydrating apparatus. .
Note that the predetermined gap G2 is an interval directly related to the suppression of the occurrence of elongation in the width direction of the front end portion of the single plate, and therefore it is important to set it carefully, and it is acceptable if it is slightly smaller than the thickness T of the single plate. However, according to the experiment, if the thickness is 85% or less of the thickness T of the single plate, the front end portion of the single plate tends to easily extend in the width direction. There is practically 90% or more of the thickness T of the single plate.

  Thus, when the single plate 5 is passed through the dehydrating apparatus illustrated in FIG. 5, the upper roll 3 is preliminarily held at the ascending limit position indicated by the solid line in FIG. In addition, as illustrated in FIG. 6, mild compression is started when the foremost end of the single plate 5 is sandwiched between the lower roll 1 and the upper roll 3. As illustrated in FIG. 7, even if it is assumed that the upper roll 3 is lowered to the operating position, the upper roll 3 is appropriately separated from the foremost end of the single plate 5 (a distance indicated by a symbol L <b> 1 in FIG. 8). FIG. 8 shows an example in which the upper roll 3 is kept waiting at the ascending limit position until the part is not excessively compressed, and the veneer 5 is passed to a position where the part is not excessively compressed. Thus, the upper roll 3 is lowered to the operating position via the operating mechanism 8 to strengthen the compression, and thereafter, the lower roll 3 is lowered to the operating position until the last end of the single plate 5 passes. Maintaining and compressing the veneer 5 as desired, the dehydration process is performed, and when the rear end of the veneer 5 has passed, the upper roll 3 is again shown in FIG. Raise to the ascent limit position indicated by the solid line. Thereafter, the dehydration process can be performed through the single plate 5 one after another by repeating the same operation.

  According to such a dehydration method, in the range from the foremost end of the veneer 5 to a site that is appropriately spaced apart, mild compression by the lower roll 1 and the upper roll 3 will be performed. As is well known, a veneer is a material that is slightly elastic in the thickness direction, and since there is a tendency that the elastic range increases in proportion to the thickness, a relatively thick veneer is dehydrated. In the case of processing, even if light compression is applied to the front end portion of the veneer in this way, it is difficult for the front end portion of the veneer to extend in the width direction, and naturally compression by a pair of rolls is started. After that, the portion following the front end of the veneer is also less likely to stretch, so it is suitable for preventing the occurrence of fine cracks over the entire length of the veneer and for reducing the dehydration effect. It is effective.

  In addition, according to the dehydration method as described above, since the desired dehydration process is not performed on the front end of the veneer, the moisture content of the front end of the veneer is higher than the moisture content of other parts. However, as described above, there is no possibility of causing a difference in dry state that would impede practical use after drying due to various factors. In addition, with respect to the recommended value for reducing the compression to the front end of the single plate, which is indicated by the symbol L1 in FIG. 8, the properties of the single plate, the form of the pair of rolls, or the predetermined gap G2 In order to correspond to the adopted value, etc., it is desirable to determine it based on experiments, but as a guideline, about 3 mm to 15 mm is appropriate, and the front end of the single plate is assumed to be in the axial direction of the pair of rolls. If there is a possibility of being sandwiched in a somewhat slanted state, the distance from the front end on the side where the passage is delayed may be 3 mm or more.

  In addition, according to the dehydrating method of the present invention, even if a single plate whose tip is difficult to feed to a pair of rolls, such as a single plate having a node at the tip, reliable feeding can always be performed. As mentioned above, there is another effect that the problem that the veneer turns around the node or the processing (carrying in) of the veneer is delayed is also eliminated. It is.

  When any one of the dehydration methods is performed, a pair of auxiliary feed rolls (10, 10a) and one or two single plate detectors (11) are provided as shown in the figure. The front end of the single plate 5 is detected by the single plate detector (11) using the dewatering device, and detecting the passage of the front end of the single plate 5 and corresponding to the driving speed of the auxiliary feed roll (10, 10a). After a delay time sufficient to reach the required position, the operation mechanism 8 is operated and a means for lowering the upper roll 3 to the operation position is taken, so that a series of operations can be automatically performed. However, the dehydrating apparatus that can be used is not necessarily limited to the dehydrating apparatus having such a configuration and is not illustrated.For example, pressure contact with a pair of upper and lower rolls to a portion that is appropriately spaced from the front end is provided, Started or enhanced Instead of the single plate detector (11), the single plate detector for detecting the position of the rear end of the single plate at the time when the power should have been reached, above the single plate guide (9) on the first entry port side, etc. Even if the single plate detector detects the passage of the rear end of the single plate, operates the operating mechanism, and lowers the upper roll to the operating position, the dehydration method as described above is extremely difficult. It can be easily implemented.

  On the other hand, similarly to the dehydrating apparatus illustrated in FIG. 4 and FIG. 5, if a dehydrating apparatus comprising a pair of auxiliary feed rolls and one or two single plate detectors is used, As will be described later, it is convenient because a dehydration method that suppresses the occurrence of elongation in the width direction on the rear end side of the single plate and prevents the occurrence of cracks due to elongation can be carried out very easily. .

  That is, as illustrated in FIG. 9, for example, a pair of auxiliary feed rolls 10 and 10a and one or two single-plate detectors 11 are respectively disposed in the same manner as the dehydrating apparatus illustrated in FIG. In addition, a pair of auxiliary feed rolls 12 and 12a, in which at least one of them can be driven and rotated at the same speed as the driving speed of the lower roll 1, are additionally provided as necessary, and the dehydrator is provided. Configure.

Thus, by performing any one of the above-described dehydration methods through the single plate 5 in the dehydrating apparatus configured as illustrated in FIG. 9, the single plate detector is in the process of performing the dehydration process on the single plate 5. 11, the passage of the rear end of the single plate 5 is detected, and when the portion separated by the distance L2 from the rear end is appropriately pressed by the pair of upper and lower lower rolls 1 and 3, FIG. As illustrated, by raising the upper roll 3 to the standby position (or ascending limit position) via the operating mechanism 8, after the single plate from the part separated by the distance L2 from the rear end to the rear end. With respect to the end portion, a dehydration method that pauses or reduces compression by the pair of upper and lower lower rolls 1 and 3 can be performed very easily.
In addition, in the case of adopting a configuration in which the compression by the pair of upper and lower lower rolls 1 and upper roll 3 is stopped, if the auxiliary feed rolls 12 and 12a are not additionally provided, the lower roll 1 It is sufficient to pull out the veneer 5 manually after stopping the compression with the upper roll 3.

  As described above, in the conventional method, on the front end side of the single plate, when the expansion in the width direction occurs due to the compression by the pair of rolls, the subsequent single plate that has not yet been compressed. Since this part acts to suppress the occurrence of elongation, it is fine even if cracking occurs, but on the rear end side, there is no subsequent part that suppresses the occurrence of elongation. There is a tendency for the length and spread of cracks to increase, and in the subsequent heating and drying process, the probability that cracks will expand, and the probability of cracks expanding due to manual handling increases, and the quality of the veneer Although there is a high possibility of adversely affecting the yield, according to the dehydration method as described above, compression is paused at the rear end of the veneer from the portion that is appropriately spaced from the rear end to the rear end, or Reduces the occurrence of stretch in the width direction or significantly reduces Is braking, the generation of cracks is also suppressed due to the elongation in the width direction, it is more effective.

  By the way, according to the dehydration method as described above, since the desired dehydration treatment is not performed on the rear end of the veneer, the moisture content of the rear end of the veneer is different from that of the front end of the veneer. Although it is higher than the moisture content of the part, as described above, there is no possibility of causing a difference in the dry state so as to be practically hindered after drying due to various factors. Street.

  In addition, the light compression on the rear end side can be achieved by compressing the water squeezed into the front and back surfaces of the veneer and the voids (temporary pipes, etc.) inside the veneer by compression as desired. Since it works to keep pushing out to the end, the draining effect of the water squeezed out before that can be greatly expected, which is preferable compared to the case where the compression is paused. However, if the above-mentioned arbitrary interval (G) is set to be equal to the thickness (T) of the veneer, the water squeezed on the front and back surfaces of the veneer can be expected to have a water draining effect. It is.

  In addition, about the recommended value of the distance which pauses or reduces the compression to the rear end portion of the single plate, which is indicated by the symbol L2 in FIG. 9, the properties of the single plate, the form of the pair of rolls, the predetermined amount In order to correspond to the specific value of the gap (G2), etc., it is desirable to determine it based on experiments. However, as a guideline, the above-mentioned distance of the distance for stopping or reducing the compression to the front end of the veneer It is appropriate that the distance is equal to or more than the recommended value, and it is also possible to make the distance slightly longer than the recommended value at the front end of the veneer.

  Of course, the dehydrating apparatus that can be used for carrying out the dehydrating method as described above is not limited to the dehydrating apparatus having the configuration illustrated in FIG. 9, and is omitted from illustration. A single plate detector that detects the position of the foremost end of a single plate when it is time to stop or reduce the pressure contact with a pair of upper and lower rolls on the rear end of the single plate Separately provided above the single plate guide (9a), and the single plate detector detects the arrival of the foremost end of the single plate, operates the operating mechanism, and moves the upper roll to the standby position (or ascending limit position). ), The dehydration method as described above can be carried out very easily.

  Thus, regardless of which dehydration method is used, as for the separation / access mode of the pair of rolls constituting the dehydration apparatus, only one of the rolls is used with respect to the other roll as shown in the illustrated embodiment. Although it is sufficient to adopt a configuration that can be separated and approached, although illustration is omitted as necessary, it is possible to adopt a configuration that allows both rolls to be separated and approached with respect to the other roll. In addition to the operation mode in which both rolls are operated together, for example, the operation distance is set to be different for each roll, and on the front end side, one of the operation distances is set to be large. An operation mode in which the compression is completely stopped by operating only the roll, and the compression is temporarily reduced by operating only the other roll having a smaller working distance on the rear end side. , It is convenient to be carried out.

  In addition, the form of the pair of rolls constituting the dehydrating device is not particularly limited, and includes conventionally known aspects including the aspect relating to the material, the aspect relating to the shape of the peripheral surface, the aspect relating to the support system, and the like. Various forms can be adopted, and as one of the latest technologies according to the above-mentioned applicant's application (Japanese Patent Application No. 2012-85531), one of the pair of rolls is divided into a plurality of narrow rolls, Each divided narrow roll can be rotated separately via a support mechanism including a bearing, a support pin, a support member, a holding member, etc., and can be separated and accessed with respect to the drive roll on the other side of the pair. Furthermore, it is naturally possible to employ a support mode in which each narrow roll is pressed toward the drive roll separately with an appropriate pressing force using an operating mechanism including a fluid cylinder or the like.

  In the illustrated embodiment, a fluid cylinder is used to form an operating mechanism, and the fluid cylinder is convenient because it has a relatively simple structure and relatively good operability. The device constituting the operating mechanism is not limited to a fluid cylinder and is not shown. However, for example, various operating mechanisms (devices) known in the art such as various cam mechanisms, link mechanisms, etc. Can be configured.

  Next, if necessary, the configuration of the configuration that can be additionally arranged in the dehydrating apparatus that can be used for carrying out the dehydrating method according to the present invention will be briefly described. A nozzle-shaped injection member is disposed on the unloading side of the veneer to blow off the water squeezed on the front and back surfaces of the veneer corresponding to Or a suction mechanism formed by arranging a square funnel-shaped suction member on the carry-in side of the single plate, for example, for sucking the water squeezed on the front and back surfaces of the single plate As a typical example, the form of arranging the injection mechanism and the suction mechanism, etc. are mentioned as a representative example, but the point is that if it is a configuration that does not hinder the implementation of the dehydration method according to the present invention, Various configurations may be additionally provided.

  As is clear from the above, the present invention suppresses the occurrence of elongation in the width direction of the single plate, which is a problem of the conventional dehydration method, and prevents the occurrence of cracks due to the occurrence of elongation and the effect of dehydration. This is a technology that contributes to reduction and prevention, and is extremely effective in promoting the practical application of a dehydration method that mechanically dehydrates the moisture contained in a veneer. The implementation effect is remarkable.

1: Lower roll 2, 4: Bearing box 3: Upper roll 5: Single plate 6: Frame 7 and 13: Stopper 8: Actuating mechanism 9 and 9a: Single plate guide 10, 10a, 12, and 12a: Auxiliary feed roll 11: Single plate detector G: Arbitrary interval G1 equal to or greater than the thickness of the single plate: Desired interval G2 that is significantly narrower than the thickness of the single plate: Predetermined interval L slightly narrower than the thickness of the single plate L: Compression to the front end of the single plate Paused distance L1: Distance L2 that reduces compression to the front end of a single plate L2: Distance T that stops or reduces compression to the rear end of a single plate T: Thickness of the single plate

Claims (5)

  A veneer veneer between a pair of rolls, which are arranged so as to be opposed to each other with a desired interval significantly narrower than the thickness of the veneer veneer, and at least one of the pair is rotatably driven Is a dehydration method that mechanically dehydrates the moisture contained in the veneer veneer by compressing in the length direction and compressing in the thickness direction, wherein at least one of the pair of rolls is made to the other roll In addition to being capable of separating / approaching operation, the operation of separating the desired roll from the standby position separated from the other roll by an arbitrary interval equal to or greater than the thickness of the veneer veneer. It is assumed that the pair of rolls are brought close to the desired distance in the case of having an operation mechanism for alternately separating and approaching to the position and passing at least the front end side of the veneer veneer between the pair of rolls. do it , Until the part separated from the front end of the veneer veneer by an appropriate distance is not compressed, the compression is temporarily stopped by separating the operable roll from the standby position, and the part is not compressed. A veneer veneer dewatering method characterized in that, after passing a veneer veneer to a position, an actuable roll is brought close to the operation position via an actuating member and compression is started as desired.   A veneer veneer between a pair of rolls, which are arranged so as to be opposed to each other with a desired interval significantly narrower than the thickness of the veneer veneer, and at least one of the pair is rotatably driven Is a dehydration method that mechanically dehydrates the moisture contained in the veneer veneer by compressing in the length direction and compressing in the thickness direction, wherein at least one of the pair of rolls is made to the other roll The separation limit is provided so as to be capable of separation / approaching operation, and the separation-provided roll is separated from the other roll by a predetermined interval that is wider than the desired interval and slightly narrower than the thickness of the veneer veneer. A pair of rolls provided with an actuation mechanism for alternately separating and approaching a position and an actuation position spaced apart from each other at a desired interval, wherein at least the front end side of a veneer veneer is passed between the pair of rolls. The Even if it is assumed that the distance is close to the desired distance, the operable roll should be separated to the separation limit position until the portion separated by an appropriate distance from the front end of the veneer veneer is not excessively compressed. To reduce the compression for a while, and after passing the veneer veneer to a position where the part is not excessively compressed, the operable roll is brought close to the operating position via the operating member, and the desired compression is started. A method for dewatering a veneer veneer characterized by:   Even in the case where the rear end side of the veneer veneer passes between the pair of rolls, the operation at an appropriate distance from the rear end of the veneer veneer is separated by a desired interval that is significantly narrower than the thickness of the veneer veneer. When reaching the position where it is in pressure contact with each roll in the position, a standby position in which the operable roll is separated from the other roll by an arbitrary distance equal to or greater than the thickness of the veneer veneer via the operating mechanism. Alternatively, the compression may be stopped or reduced as desired by separating it to a separation limit position that is wider than the desired interval and slightly narrower than the thickness of the veneer veneer. A method for dewatering a veneer veneer according to claim 1 or 2.   The veneer veneer dewatering method according to claim 1, 2 or 3, wherein only one of the pair of rolls is provided so as to be capable of separating and approaching the other roll.   4. The veneer veneer dewatering method according to claim 1, wherein both of the pair of rolls are provided so as to be able to be separated and approached with respect to the other roll.

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