JPH04223101A - Discriminating method of veneer - Google Patents

Abstract

PURPOSE:To discriminate the presence and absence of unstraight grain existing in veneer by a method wherein the distance between the edges on the end grain sides of the veneer is measured. CONSTITUTION:Veneer, which is cut with a veneer lathe 5 in standard width before drying, is dried in a drying device 6 so as to measure the distance between the edges on the end grain side of the veneer after drying with an edge detector 11 provided at the position, at which the passing of the edge on the end grain side of the veneer having said standard width is foreseen. The veneer, which passes through a passing detector 12 and does not pass through the edge detector 11, is discriminated by a controlling circuit 13 as the veneer having unstraight grain. As a result, a discriminating device 8 is put into actuation so as to change the conveying and processing device of the veneer having no unstraight grain.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for determining the presence or absence of non-through grain in a veneer veneer by measuring the distance between the end edges of the veneer.

0002

[Prior Art] Conventionally, plywood is made of multiple sheets of the same thickness or different thicknesses, which are cut from logs selected as suitable materials for plywood among logs mainly made of South Sea lumber, and cut to the required dimensions. Manufactured by layering veneers. The veneer obtained from the raw wood (hereinafter referred to as effective veneer) is produced by the drying process because the fiber direction of the veneer is almost parallel to a line perpendicular to the butt end edge (hereinafter referred to as imaginary line). In anticipation of shrinkage in the same direction perpendicular to the imaginary line and the fibers of the wood, plywood is produced by stacking the veneers in a perpendicular state,
This prevents distortion. The selection of materials suitable for plywood and materials unsuitable for plywood is carried out in accordance with empirical rules, for example, at each time of felling, shipping, unloading, etc.
The reality is that logs that are excluded as unsuitable for plywood are either left uncut or unshipped, or are redirected to other uses such as lumber. However, with the depletion of wood resources in recent years, it has become impossible to ignore logs in which at least some of the fibers have significantly non-straight grains, and in order to effectively utilize them, this application In addition to developing an innovative peripheral drive type veneer lace disclosed in ``Veneer Lace'' (Japanese Patent Publication No. 56-16729), he also developed ``Plywood with Less Distortion and Method of Manufacturing the Plywood'' (Japanese Patent Application Laid-Open No. -185402 Publication), at least a pair of veneers at symmetrical positions in the thickness direction of the plywood are cut from the raw wood having non-straight grains and have intersecting grains. A method for manufacturing plywood in which the cross grains are arranged symmetrically in almost the same area has been disclosed.

0003

[Problems to be Solved by the Invention] However, in the above-mentioned plywood manufacturing method, it is difficult to form plywood with almost uniform grains, and the number of work steps increases. Conventional manufacturing methods may be used. In that case, even among the raw wood from which effective veneers can be obtained, veneers with partially non-straight grains (hereinafter referred to as unused veneers) may be produced, especially in the knots and around the joints. As is well known, if the effective veneer and unused veneer are made into plywood on a conventional manufacturing line, the product will warp significantly. If the discrimination is performed manually, the processing speed will be slow. Therefore, there was a need for a method to automatically distinguish between valid veneers and unused veneers on the same production line. A method of directly determining the inclination state of the fibers has been considered, but this method has the disadvantage that the inclination state of the fibers and the reflectance are not necessarily in a proportional relationship, and the determination device is also complicated.

0004

[Means for Solving the Problems] The present invention measures the distance between the end edges of the veneer before and after drying the veneer, and separates the veneers with different distances from each other. This is a method for distinguishing plywood with distortion from veneer with inherent straight wood grain.The first step is to specify the distance between the end edges of the veneer, and the veneer whose distance between the end edges of the veneer has been specified. a third step of measuring an arbitrary distance including at least the shrinkage distance of the end edge of the veneer after drying; and a third step of measuring the specified distance before drying and the end edge of the veneer after drying. This veneer identification method includes a fourth step of comparing the distance between the side edges, and a fifth step of identifying the veneer based on the comparison results. Here, the end of the wood refers to the cross section in the direction of the fibers of the wood, and dry veneer does not include undried wood, but it also includes minute drying that causes shrinkage that exceeds the error in measurement ability. The time and place required for drying are not limited, such as natural drying or forced drying, and the drying may be performed at a location away from the measurement location. 1st
In order to "specify the distance between the end edges of the veneer" in the process, the veneer before drying may be cut so that the end edges of the veneer are a certain distance apart by marking with a known veneer lace, or This is done by cutting a veneer cut with veneer lace so that the end edges on the buttside are a certain distance apart, or by measuring the distance between the edges on the buttside. In addition, as a method for measuring the distance before and after the drying process, the veneer is transported in the direction of the fibers to a fixed point, and the distance of the end edge of the veneer is measured from the speed and time at which the end edge of the veneer passes. The veneer is conveyed in the fiber direction or in a direction perpendicular to the fiber direction, one end of the end edge of the veneer is aligned with the reference line, and a phototube or the like is installed at a predetermined distance from the reference line to detect the veneer. There is a method of determining whether the veneer is a veneer having the predetermined distance or not.

[0005]

[Function] In the first step, the distance between the end edges of the veneer is determined by cutting the veneer to a constant width or measuring the distance between the end edges of the veneer before drying, and in the second step, the drying shrinks in the direction perpendicular to the fibers, so an effective veneer whose fiber direction is almost parallel to the imaginary line will shrink in the direction perpendicular to the imaginary line, and the distance between the edges on the butt side will not change in the imaginary line direction. On the other hand, if an unused veneer that has a part in which the fiber direction is not parallel to the imaginary line shrinks in the direction perpendicular to the fibers in that part, the veneer as a whole will shrink in the direction parallel to the imaginary line or in a direction parallel to the imaginary line. As the shrinkage occurs in the approximated direction, the distance between the buttside edges changes, so in the third step, the distance between the buttside edges of the veneer after drying is measured, and in the fourth step, the distance is measured before and after drying. In comparison, a veneer with no change in distance in the fifth step is a veneer with no internal non-through grain,
This is to distinguish veneers with different distances from each other as unused veneers with inherent non-through grain.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a discriminating device according to the discriminating method of the present invention will be described below with reference to the drawings. In the veneer discrimination device according to the present invention, for example, as illustrated in FIG. A known drying device 6 is provided between them, and a sorting device 8 is provided at the end of the carry-out conveyor 7b opposite to the drying device 6. (Example 1) In this example, a constant width veneer or a constant width veneer having a thickness twice as thick as a constant width veneer, which is supplied by cutting the edge of the end side at a certain distance by marking in a known veneer lace 5, is used. This is a case where a constant width veneer (hereinafter referred to as veneer A) is dried using a known drying device 6 and is transported with the imaginary line a of the veneer perpendicular to the transport direction. Here, claim 2
The ``process of cutting the veneer to a constant width before drying'' in the first step of It is necessary to know the distance, and instead of measuring the distance as in the second embodiment described later, the distance is arbitrarily set at the beginning. It should be noted that instead of identifying only veneers where the distance difference between the veneers before and after the drying process is zero as valid veneers, the allowable range can be set arbitrarily based on factors such as the yield of veneers, and it is also possible to determine the effective veneer. The ratio of the allowable distance difference for determining a board to the entire detection side edge can be set arbitrarily, and hereinafter, the veneer T1 that has shrunk within the allowable distance difference as shown in Fig. 2 (A) will be referred to as an effective veneer. ,
A case will be described in which a veneer T2 having even a part of it that has shrunk beyond the allowable distance difference as shown in FIG. 2(B) is determined to be an unused veneer. A rotary belt 10 that is synchronized with the conveying speed of the conveying device 7 is rotatably supported at one end of the unloading conveyor 7b, which is conveyed with the virtual line a of the veneer perpendicular to the conveying direction, so that it can be driven parallel to the conveying direction. At the same time, the rotating belt 1
The rotating belt 1 is attached to the other end of the conveyor 7b provided with a
A veneer edge detector 11 made of a reflective phototube or the like having a distance of the constant width from A passage detector 12 such as a type phototube is provided, and a control circuit 13 is provided which outputs a signal for controlling the operation of the sorting device 8 based on signals inputted from the edge detector 11 and the passage detector 12. Note that the distance between the edge detector 11 and the passage detector 12 and a slightly lower part of the sorting device 8 is set so that it is at least as long as the constant width of the veneer before drying. The sorting device 8 has a rotating shaft on the upper side in the veneer conveyance direction, and has its tip on the conveyor 9a side that conveys veneers judged to be of good quality and on the conveyor 9b side that conveys veneers judged to be of low quality. The conveyor 9a, 9b is configured to be rotatable by a cylinder (not shown) at one end of the conveyor 9a, 9b so as to face the conveyor 9a. I'll let it happen. The control circuit 13 includes, for example, an edge detector 11 connected to a normally closed contact and a passage detector 12 connected to a normally open contact, AND circuits 40, 43, 46, and delay circuits 42, 4.
7. The memory devices 41, 45 and the NOT circuit 44 are connected and configured as shown in FIG. In addition, the wiring X is the sorting device 8
The wiring Y is for resetting the signal stored in the memory device 41 in response to the descending operation end signal of the sorting device 8, and the wiring Y is for resetting the signal stored in the memory device 45 in response to the ascending operation end signal of the sorting device 8. The delay circuit 42 starts counting when the signal from the passage detector 12 becomes closed when the lower edge of the veneer passes, and the delay circuit 42 starts counting when the lower edge of the veneer passes and the signal from the passage detector 12 becomes closed. A delay time S1 is set to count up and issue a signal when the
The delay circuit 47 starts counting when the upper edge of the veneer passes and the signal from the passage detector 12 changes from the closed state to the open state. A delay time S2 is set in such a state that it can count up and output a signal when it reaches the lower side. Embodiment 1 is provided as described above, and its operation will be explained below. When the veneer is not on the conveyor 7b, the edge detector 11 outputs a signal of 1, and the passage detector 12 outputs a signal of 0. In this state, if the veneer T1 transported by the conveyor 7a and dried by the drying device 6 is the veneer T1 that has not contracted in the direction of the virtual line a, the veneer T1 is When the lower end of the detector reaches the positions of the edge detector 11 and the passage detector 12, the edge detector 11 outputs a 0 signal and the passage detector 12 outputs a 1 signal. Therefore, the signal 1 of the passage detector 12 is
The signals are input to an AND circuit 40, a delay circuit 42, a NOT circuit 44, and a storage device 45, respectively. Among these, AND circuit 40
Since the input signal from the edge detector 11 is 0, the AND condition is not satisfied and the output of the AND circuit 40 is 0, and the signal input to the AND circuit 43 via the storage device 41 is also 0 . On the other hand, the output signal of the NOT circuit 44 becomes 0, and the storage device 45 stores that the input signal becomes 1, and continues to output a 1 signal to the AND circuit 46. The third input signal connected to the lowering operation end signal is 0 because the sorting device 8 is in the raised position. As a result, the AND condition of the AND circuit 46 is not satisfied, and an activation signal for raising the sorting device 8 is not generated. Next, after the delay time S1, the delay circuit 42 issues a signal to the AND circuit 43, but as described above, since the signal input from the storage device 41 to the AND circuit 43 is 0, the AND circuit 43 outputs a signal. Since the conditions are not satisfied, the AND circuit 43 does not issue an activation signal for the sorting device 8. As a result, the veneer T1 passes over the sorting device 8 and is guided onto the conveyor 9a. The states of these signals do not change until the upper end of the veneer T1 passes the positions of the edge detector 11 and the passage detector 12. When the upper end of the veneer T1 passes, the output signal of the edge detector 11 is 1, and the passage is detected. Although the output signal of the device 12 becomes 0, none of the AND conditions of the AND circuits 40, 43, and 46 are satisfied, and the sorting device 8 does not operate. As described above, the veneer T1 is determined as a veneer that does not include a portion that has shrunk in the direction of the virtual line a, and the sorting device 8
It passes over the conveyor 9a and is guided onto the conveyor 9a. Next, when the veneer dried in the drying device 6 is a veneer T2 having a contracted portion in the direction of the virtual line a at the lower end, the veneer T2 is as shown in FIG. 2(B). The lower end of
When the position of the passage detector 12 is reached, the output signal of the edge detector 11 remains at 1, but the output signal of the passage detector 12 becomes 1. Therefore, AND circuit 40, delay circuit 42
, the NOT circuit 44, and the storage device 45 each receive the signal 1. Among these, the AND circuit 40 connects the edge detector 11
Since a signal of 1 is input from each of the pass detector 12 and the AND condition is satisfied, the output signal becomes 1 and is stored in the storage device 41, and the signal 1 continues to be input to the AND circuit 43. The delay circuit 42 starts counting the set delay time S1. On the other hand, at this time, the output signal of the NOT circuit 44 becomes 0, and the storage device 45 stores the input signal 1, and continues to output the signal 1 to the AND circuit 46. When the veneer T2 is further conveyed from this state and the contracted portion of the veneer T2 in the direction of the virtual line a passes the edge detector 11, the output signal from the edge detector 11 is 0, but as mentioned above, the signal 1 continues to be output from the storage device 41, so AND
The state in which signal 1 continues to be input to the circuit 43 remains unchanged. Then, after counting the set time S1, that is, when the veneer T2 is conveyed by the conveyor 7b and the lower end reaches the slightly upper side of the sorting device 8, the delay circuit 42
A signal 1 is issued to the AND circuit 43. As a result, the AND condition is satisfied by the AND circuit 43 and the output signal 1 from the storage device 41, the output signal 1 is issued as an activation signal for the sorting device 8, the sorting device 8 is operated downward, and the veneer T2 is removed. It guides it onto the conveyor 9b. When the descending operation of the sorting device 8 is completed, a descending operation completion signal is issued, the memory device 41 is reset, the signal that has continued to be output from the memory device 41 is set to 0, and a signal 1 is input to the AND circuit 48. On the other hand, when the upper end of the veneer T2 passes through the positions of the edge detector 11 and the passage detector 12, the signal from the edge detector 11 becomes 1, and the output signal from the passage detector 12 becomes 0. . As a result, since the signal from the passage detector 12 is 0, the AND circuit 40 outputs a 0 signal and does not take any part in the operation of the sorting device 8. On the other hand, the NOT circuit 44 outputs a signal 1. , AND circuit 46
The AND condition is satisfied by the input of the operation end signal of the aforementioned sorting device 8 and the input of the signal 1 from the storage device 45, and the signal 1 is output. This signal 1 is input to the delay circuit 47, and the delay circuit 47 starts counting after the set time S2, that is, when the upper edge of the veneer T2 is on the conveyor 9b on the slightly lower side of the sorting device 8. When reaching , output signal 1 is input to the AND circuit 48, and since it has already been input to the other, signal 1 is output from the AND circuit 48 as the raising operation signal for the sorting device 8, and the sorting device 8 is raised. Operate. When this rising operation is completed, a rising operation end signal is issued, and the memory device 45 is reset.
The signal that continues to be output from is set to 0. As described above, the veneer T2 is determined as a veneer including a portion that has shrunk in the direction of the imaginary line a, and is guided onto the conveyor 9b, and the sorting device 8 returns the original veneer for subsequent veneers. It waits in a state. In addition, the veneer T2 had a portion at the lower end that contracted in the direction of the imaginary line a, but where on the veneer did the portion that became shorter in the direction of the imaginary line a due to shrinkage occur? Even if the passage detector 12 detects the passage of the veneer, the edge detector 1 detects the passage.
When the output signal from 1 becomes 1, it is determined that the veneer has a contracted portion in the direction of the virtual line a. (Example 2) One of the veneer identification methods according to the present invention is to partially change the above-described identification method, in which the width of the veneer in the direction of the virtual line a is unknown during drying work In particular, a veneer of any length where the width is not a constant width obtained using a known veneer lace and cutting device, a thick veneer having twice the thickness of the veneer, or a veneer of constant width cut When drying the constant width veneer or the constant thickness veneer that has naturally dried over time, a veneer that does not have a predetermined distance (hereinafter referred to as veneer B) is determined. This is a method suitable for For example, as illustrated in FIG. 5, the veneer B is rotated in synchronization with the conveyance speed of the conveyance device 7 at one end of the carry-in conveyor 7a and the carry-out conveyor 7b on which the veneer B is conveyed with the virtual line b perpendicular to the conveyance direction. The belts 20a and 20b are rotatably supported in a drivable manner parallel to the conveyance direction, and the other end of the conveyor 7a provided with the rotating belt 20a is provided with a distance at which the edge of the veneer B is expected to pass. A plurality of first edge detectors 21a, .
At the other end of the unloading conveyor 7b provided with the rotary belt 20b sequentially from the rotary belt 20b, the constant width is provided from the rotary belt 20b at a position facing the first edge detectors 21a...21e on the veneer conveyance path. A plurality of second edge detectors 22a...22e made of transmission type phototubes having a distance of
Further, a passage detector 23 such as a reflection type phototube is provided on the virtual line b in the direction orthogonal to the conveying direction of the veneer at the location of the second edge detector, and the first and second edge detectors and A control circuit 24 is provided which outputs a signal for controlling the operation of the sorting device 8 based on the signal output from the passage detector 23. In addition, the second edge detectors 22a...22e, the passage detector 23, and the sorting device 8
The distance to the slightly lower part of the veneer should be set so that it is at least as long as the longest width of the veneer before drying. A part of the control circuit 24 is configured as shown in FIG. That is,
Each first edge detector 21a, 21b, 21c, 21d
.
1a and 21b directly, the others are connected via a negative circuit 52, and the AND circuit 51c is connected to the first edge detector 2.
1a, 21b, and 21c directly, the others are connected via the negative circuit 52, and the AND circuit 51d is connected directly from the first edge detectors 21a, 21b, 21c, and 21d.
The first edge detector 21e is connected via a negative circuit 52,
The AND circuit 51e includes first edge detectors 21a and 21b.
, 21c, 21d, and 21e are all directly connected. Delay memory devices 53a...53e using magnetic drums are connected to the output sides of these AND circuits 51a...51e, respectively. However, the first edge detector 21a...2
It is set to output the signal that has passed through the point 1e in accordance with the timing when the lower side edge reaches the passage detector 23, and although it is not shown in the figure, When the edge portion passes the passage detector 23, it is configured to be reset by the signal. Further, on the output side of each delay storage device 53, a normally open contact of the second edge detector 22a is connected to the one corresponding to the AND circuit 51a;
A second edge detector 22 corresponds to the ND circuit 51b.
The normally open contacts of b are connected to the second edge detector 22e, respectively. Furthermore, the output sides of the normally open contacts of the second edge detectors 22 a . . . 22 e are connected to the OR circuit 54 . The output side of the OR circuit 54 of the circuit provided in this way is connected to the input side of the AND circuit 40 instead of the edge detector 11 of FIG. It is sufficient if the side is connected instead of the passage detector 12. sorting device 8,
Conveyors 9a, 9b, etc. are provided in the same manner as in the first embodiment. The second embodiment is provided as described above, and the veneer is discriminated as follows. As shown in FIG. 4, when the lower end of the veneer B conveyed by the conveyor 7a reaches the first edge detector 21, 21a, 21 of the first edge detectors 21a...21e
The signal 1 is outputted from the terminals b and 21c, and the signal 1 is not outputted from the terminals 21d and 21e. Therefore, the AND condition of only the AND circuit 51c is satisfied, and the signal 1 is stored in the corresponding delay recording device 53c. Next, after the veneer B is dried, it is conveyed by a conveyor 7b, and the lower end of the veneer B is transferred to the second edge detector 2.
The signal 1 is outputted from the delay storage device 53c in accordance with the timing of reaching the locations 2a, . . . 22e. As mentioned above, this signal 1 continues to be output until the upper edge of the veneer B passes the passage detector 23, and
If the veneer B is not contracted in the direction of the virtual line, the edge detector 22c made of a transmission type phototube will not be in the closed state while the passage detector 23 is detecting the veneer B, and the OR The inputs of the circuit 54 are all 0, and the AND circuit 40 is A
The ND condition is not satisfied and it is determined that the veneer has not contracted in the direction of the virtual line, and the sorting device 8 does not operate downward.
Waiting in the elevated position. Further, if the veneer B is a veneer that has shrunk in the direction of the virtual line, the passage detector 2
3 detects the veneer B, if it detects that even a part of the veneer is chipped and shrunk, the edge detector 22c becomes closed, and the signal 1 is input to the OR circuit 54. Signal 1 is output from circuit 54. As a result, the AND condition of the AND circuit 40 is satisfied, and it is determined that the veneer has shrunk in the direction of the imaginary line, and the sorting device 8 is operated downward in the same way as in the first embodiment, and the veneer is guided onto the conveyor 9b. It is. In addition to the above-mentioned Example 2, as a method for measuring the width of the veneer in the direction parallel to the virtual line a after drying,
Instead of the edge detectors 22a, . . . 22e, one second edge detector 22a is provided so as to be movable in the direction of the imaginary line b by an electrical or physical method, and the first edge detector 21c that has passed through the second edge detector 22a After moving to the corresponding position, it is also possible to determine whether the dried veneer B passes by using the second edge detector 22a and the passage detector 23, as in the first embodiment. Furthermore, in the first and second embodiments, when the edge detector 11 detects a veneer, the rotating belt 10
It is necessary to bring one end of the veneer into contact with the veneer, but since the speed of the conveying device 7 that carries out the veneer from the drying device 6 is slow,
A worker can push each veneer toward the rotating belt 10 so that the edges come into contact with each other, but if the conveyance speed becomes faster or the working time becomes longer, it is necessary to use a known width. It is desirable to install the shifting mechanism in front of the rotating belt 10. In addition, the unused veneer signal outputted from the control circuit 13 is outputted to an output device that can be detected by humans using a siren, light emitting light, vibration, etc. in addition to the sorting device, and is sorted by a worker and transferred to another production line. It is also possible to replace it with a. (Embodiment 3) Next, one of the plywood discrimination methods according to the present invention is a discrimination device in which the virtual line of the veneer is conveyed at right angles to the conveyance direction in Examples 1 and 2. On the other hand, this is an example of a discriminating device that is transported in a parallel state. For example, as illustrated in FIG. 7, the distance that the end of the veneer is expected to pass is set at one end of the unloading conveyor 7b of the conveying device 7, where the virtual line c of the veneer is conveyed parallel to the conveying direction. A plurality of edge detectors 31a, 31b, . . . 31e such as reflective phototubes are sequentially provided on a straight line in a direction perpendicular to the conveying direction of the veneer, and the veneer is sorted based on the signals output from the edge detectors. A control circuit 33 is provided which provides signals for controlling the operation of the device 8. Note that the distance between the edge detectors 31a, . . . 31e and a slightly lower part of the sorting device 8 is set so that it is at least as long as the standard length of the veneer before drying. The control circuit 33 is configured as shown in FIG. That is, each edge detector 31a, 31b,
Normally closed contacts 31c, 31d, and 31e are connected in parallel to an OR circuit 60 and an AND circuit 61. An EOR circuit 62 (exclusive OR operation) is connected to the output sides of the OR circuit 60 and the AND circuit 61. EOR circuit 62
The output side is connected to an AND circuit 64 through a delay storage device 63 using a magnetic drum and directly. This delay recording device 63 includes an OR circuit 60 and an AN
Counting starts when the output signal of the D circuit 61 is different,
The output is set to match the timing when the upper and lower edges of the veneer with the allowable distance between the butt ends pass the edge detector.For example, if the allowable distance is set to 0, the delay time is set. becomes 0. The delay device 68 outputs the input signal 1 after being delayed by the time required for it to be conveyed from the edge detectors 31a...31e to a point slightly above the sorting device 8 due to the conveyance speed of the conveyor 7b. Also, the delay device 72 is configured such that the input signal 1 is detected by the edge detector 31a depending on the conveyance speed of the conveyor 7b.
. . The output is set to be delayed by the time required to be transported from the location 31e to a location slightly lower in the sorting device 8. The sorting device 8, conveyors 9a, 9b, etc. are provided in the same manner as in the first embodiment. The third embodiment is provided as described above, and the veneer is discriminated as follows. As shown in FIG. 2(C), when the lower end T3 of the veneer being conveyed by the conveyor 7b reaches the edge detectors 31a...31e, the edge detectors 31a, 31b, 31c signal 1. is output, and 31d and 31e through which the contracted edge passes are not output. Therefore, the OR condition of the OR circuit 60 is satisfied, the EOR circuit 62 outputs the signal 1, and the signal 1 is output to the delay recording device 63.
is memorized. Then, the remaining edge detectors 31d, 31
When the edge passes through e, the AND condition of the AND circuit 61 is satisfied, the output signal becomes 1, and the EOR circuit 62 does not output a signal. Similarly, as shown in FIG. 2(D), when the upper end T4 of the veneer transported by the conveyor 7b reaches the edge detector 31, the edge detectors 31a...31e
31a, 31b, of which the contracted edge passes first;
No signal is output from 31e, and 31c and 31d still output signal 1. Therefore, the AND circuit 61's AN
Since the D condition is not satisfied, the EOR circuit 62 outputs the signal 1, and the signal 1 is stored in the delay recording device 63. Then,
When the edge passes through the remaining edge detectors 31c and 31d, the OR circuit 60 no longer outputs, and the EOR circuit 62 also does not output. If the veneer T1 is not contracted in the direction of the virtual line, the signal from the EOR circuit 62 is 0 when the delay recording device 63 outputs the signal 1.
The AND circuit 64 determines that the AND condition is not satisfied and that the veneer has not shrunk in the direction of the imaginary line, and the sorting device 8 does not move downward and waits at the raised position, so the veneer T1 is It is guided onto the conveyor 9a. When one of the edge detectors 31a to 31e detects the lower edge of the veneer, the OR circuit 60 outputs a signal 1, which is input to the delay circuit 68. If the veneer T2 has shrunk in the direction of the virtual line beyond the allowable range, the delay recording device 6
When signal 1 is output from 3, the signal from EOR circuit 62 is also 1, so signal 1 is output from AND circuit 64 to storage device 66. Signal 1 is output from the storage device 66.
The signal continues to be input to the AND circuit 65, and when the set time elapses, the signal 1 is output from the delay circuit 68.
The signal is input to the D circuit 65. As a result, AND circuit 65
When the AND condition is satisfied, the signal 1 is output, the sorting device 8 is moved downward, and the veneer T2 is guided onto the conveyor 9b. On the other hand, the AND circuit 71 stores the signal 1 from the OR circuit 60 in the storage device 70 and continues to output the signal 1 to the AND circuit 71. Next, when the upper edge of the veneer T2 passes through the edge detectors 31a...31e, the output from the OR circuit 60 becomes 0, and the output from the NOT circuit 69 becomes 1, resulting in an AND circuit. When the AND condition 71 is satisfied, the signal 1 is input to the delay circuit 72, and when the set time has elapsed, the signal 1 is input from the delay circuit 72 and is input to the AND circuit 73. At this time AND
Since the operation end signal of the sorting device 8 has already been input to the circuit 73, the AND condition of the AND circuit 73 is satisfied, the signal 1 is outputted, and the sorting device 8 is operated upward. Note that the memory device 66 is reset by the descending operation end signal, and the memory device 70 is reset by the end of the ascending operation. Note that it is desirable that a guide member be provided in the conveying device 7 so that the veneer is conveyed while maintaining the virtual line of the veneer parallel to the conveyance direction. In addition, when using a veneer of variable width, a plurality of edge detectors 31 are arranged throughout the width direction of the conveying device 7, and a passage whose number and mounting position correspond to the edge detectors 31 on the carry-in conveyor 7a is provided. A plurality of detectors are provided, and the veneer is discriminated after drying using only the edge detector 31 corresponding to the passing detector through which the veneer has passed.

[0007]

[Effects of the Invention] According to the determination method configured as described above, the quality of veneers can be automatically determined on a production line where effective veneers and unused veneers with non-through grains coexist. Since we can select the manufacturing method suitable for each type of veneer, we can always supply high-quality plywood. In addition, in conventional veneer lace, the worker visually determines the condition of the raw wood and changes the cutting width direction of the veneer, but with the present invention, the cutting width direction is determined after determining the valid veneer and unused veneer. It becomes possible to cut in the same direction, increasing the yield and making efficient use of wood resources.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a discriminating device using a veneer discriminating method according to the present invention.

FIG. 2 is an explanatory diagram of effective veneers and unused veneers in the veneer discrimination method.

FIG. 3 is a side view of the sorting device.

FIG. 4 is a circuit diagram of a control circuit of the discrimination device.

FIG. 5 is a plan view of a discrimination device according to a second embodiment.

FIG. 6 is a control circuit diagram of a part of the control circuit of the discrimination device.

FIG. 7 is a plan view of a discrimination device according to a third embodiment.

FIG. 8 is a circuit diagram of a control circuit of the discrimination device.

[Explanation of symbols]

T1, T2, A, B...Single plate, 5...Cutting device, 6...
Drying device, 7... Conveying device, 8... Sorting device, 9a...
Effective veneer transport conveyor, 9b... Unused veneer transport conveyor, 10, 20... Rotating belt, 11, 21, 22, 3
1... Edge detector, 12, 23... Passage detector, 13,
24, 33...control circuit, 40, 43, 46, 48, 5
1, 61, 64, 65, 71, 73...AND circuit,
42, 47, 63, 68, 72...Delay circuit, 41, 4
5, 53, 66, 70...Storage device, 44, 69...NOT circuit, 54, 60...OR circuit, 62...EOR circuit, arrow...Single board conveyance direction

Claims (4)

[Claims] 1. A first step of specifying the distance between the end edges of the veneer, a second step of drying the veneer for which the distance between the end edges of the veneer has been specified, and the step of drying the end of the veneer after drying. a third step of measuring an arbitrary distance including at least the shrinkage distance of the side edge; a fourth step of comparing the specific distance before drying with the distance between the end edges of the veneer after drying; A method for identifying veneers, comprising a fifth step of identifying veneers based on the comparison results. 2. A first step of cutting the veneer to a constant width before drying, a second step of drying the veneer, and a third step of detecting the passing position between the end edges of the veneer after drying. a fourth step of comparing the constant width with the distance between the end edges of the veneer after drying; and a fifth step of identifying the veneer based on the comparison results. . 3. A first step of measuring the distance between the end edges of the veneer before drying, a second step of drying the veneer, and measuring the distance between the end edges of the veneer after drying. A third step of
A veneer identification method comprising a fourth step of comparing the distance between the end edges of the veneer before and after drying, and a fifth step of determining the veneer based on the comparison results. 4. A first step of cutting the veneer to a constant width before drying, a second step of drying the veneer, and a third step of measuring the shrinkage distance of the end edge of the veneer after drying. and a fourth step of comparing the shrinkage distance of the end edge of the veneer before and after drying.
and a fifth step of determining the veneer based on the comparison results.