JPS595499B2 - Automatic stacking device for narrow veneer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention provides that among the narrow veneers that are cut to a certain width by a veneer cutting machine and transported, the narrow veneers longer than a predetermined width are placed in the first half of the pile where the pile place is divided into two. The small width veneer, which is deposited at the front or rear end of each of the front and rear parts, and whose width is shorter than the specified width, is placed at the center of each of the front and rear parts of the pile, which bisects the deposition area. By controlling the deposition, the front and rear ends of the subdivided piles are aligned with each other, and the entire subdivided pile is formed into a nearly horizontal pile, which improves the work efficiency of the subsequent process. This relates to an automatic stacking device for narrow veneer plates that is configured to be able to do so.

In conventional equipment, small-width veneers that have been cut to a certain width by a veneer cutting machine and transported are assembled horizontally into a group of small-width veneers by a predetermined cumulative width, and the upper surface is The upper surface conveyor continues transporting the group of narrow veneers by adhesion or suction, and the upper surface is held by detecting the front end or rear end of the small width veneer group. Since it was based on the automatic cumulative laminated deposition method in which the sheets are unraveled all at once and deposited directly below, in the case of this kind of conventional cumulative laminated pile construction method for groups of narrow veneers, there is a layer at the front and rear ends of the pile in the later process. Since the extremely small width of the veneer, which cannot be used as a product, will be cut cumulatively, the product yield will be reduced.
In addition, if such extremely small width veneers are assembled at the front and rear ends of the stack, during the stacking operation to release the top surface retention, they may fall or hang diagonally, resulting in a messy stacked state. This made continuous and stable deposition work impossible. This invention is designed to eliminate the drawbacks of the conventional apparatus described above, such as lower yield and disordered deposition.First, an embodiment of the invention will be explained. The narrow width veneer 2 is cut to a certain width by a veneer cutting machine in the process and is conveyed by a conveyor 1. The upper surface of the veneer 2 is held by a pruning conveyor using a needle belt or the like or a suction conveyor using a perforated belt or the like. Conveyance is continued by the upper surface conveyor 3 that applies conveyance force.

The veneer veneer 2, which is being continuously conveyed by the upper surface conveyor 3, is in the first half of the deposition area, and consists of photoelectric switches, limit switches, etc. installed before and after the latter half of the deposition area, which determines the position of the front end of the first half of the deposition area. A front end detector 4A for the first half, a rear end detector 5 for the first half that determines the rear end position of the first half, a front end detector 4A for the second half that determines the front end position of the second half of the stack, and a rear end detector 4A for the second half that determines the rear end position of the second half. For the rear end detector 5A for the rear half to be determined, the rear end detector for the rear half first passes through the rear end detector 5A for the rear half, the front end detector 4A for the rear half, and the rear end detector 5 for the front half. When the edge detector 5 detects the arrival of the narrow veneer 2, the detection signal is sent to the front half consisting of a timer, a shift register, a preset counter, etc., which determines whether the width is longer or shorter than a predetermined width based on its passing time. The signal is input to a stacking switching circuit 7 for the first half, which includes a length discrimination circuit 6 and a ratchet relay for switching the detection operations of the front end detector 4 for the first half and the rear end detector 5 for the first half.

For example, when using a timer, the temporal length discrimination means by the length discrimination circuit 6 for the first half part can be used to divide a predetermined width into 1001
1KI, and the conveyance speed of the top conveyor 3 is 60m/
If Min, the time required for the upper surface conveyor 13 to convey the narrow veneer 2 by 100 m1 is 100 msec.
The delay time of the timer is set at the position where the timer is set up, and the timer setting time is 100 minutes.
If the input of the detection signal from the rear end detector 5 for the front half is cut off within msec, for example 80 msec, the timer is not set up, so this is a predetermined width.
If it is determined that it is a short narrow veneer 2a with a width of 00U1 or less, and the input of the detection signal from the rear end detector 5 for the front half is cut off after 120 msec, the timer has already been set up. This is the specified width 1001
It is discriminated that it is a long narrow width veneer 2b having a width of one width or more.

Further, the discrimination signal of the short narrow width veneer 2a discriminated by the length discrimination circuit 6 for the front half section is applied to the short narrow width veneer plate 2a at the approximately central position between the front end position and the rear end position of the front half part of the deposition location. 2a is transmitted to a deposition position changing circuit 8 for the first half consisting of a timer, a shift register, a preset counter, etc. so as to drop and deposit the first half. The transmitted discrimination signal for the short width veneer 2a is stored and delayed once, and the discriminated short width veneer 2a arrives at approximately the center position between the front end position and the rear end position of the front half of the deposition place. The discrimination signal of the short narrow veneer 2a, which has been stored and delayed, is regenerated and transmitted to the output circuit 9 for the front half, and the output circuit 9 for the front half is thereby activated by an electromagnetic clutch brake, an air cylinder, etc. The first half release device 10', consisting of an intermittent drive device 10a and a knock-down bar 10b, is activated to release the upper surface holding, and a short narrow veneer 2a is placed in the center of the front half of the deposition area directly below. Falling and depositing.

Furthermore, the discrimination signal for the long narrow veneer 2b discriminated by the length discrimination circuit 6 for the first half is sent to the stacking switching circuit 7 for the first half.
When the first half stacking switching circuit 7 is switched to the detection operation side of the first half front end detector 4, the first half front end detector 4 detects the arrival of the long narrow veneer 2b. At the same time, the detection signal is transmitted to the output circuit 9 for the front half, and the output circuit 9 for the front half activates the release device L for the front half consisting of the intermittent drive device 10a and the knock-down bar 10b to hold the top surface. Then, the long narrow veneer 2b is dropped and deposited at the front end position of the first half of the depositing place directly below.

In this case, a large number of long narrow veneers 2b continue to be transported.
In this case, the deposition switching circuit 7 for the first half is connected to the front end detector 4 for the first half.
While the detection operation side is on the front end position of the front half of the lifting table 11, the operation of dropping and depositing the long narrow veneer 2b is repeated by aligning it with the front end position of the front half of the deposition place. A light emitter 12a detects the overall accumulation level of the thin veneer veneer 2b that has been dropped and deposited to a predetermined height and emits light from the rear end position of the second half to the front end position of the first half. Overall level detector consisting of a device 12b etc.
2, the light receiver 12b of the overall detector 2 inputs a detection signal to be lowered to the 5 drive circuit 13 of the lift table 11, and the drive circuit 13 lowers the lift table 11 and detects the A switching signal is transmitted to the stacking switching circuit 7 to switch the circuit from the detection operation side of the front end detector 4 for the first half to the detection operation side of the rear end detector 5 for the first half. Then, the long narrow veneer 2 was transported to the rear end detector 5 for the front half.
In b, since the deposition switching circuit 7 for the first half has already switched to the detection operation side of the rear end detector 5 for the first half, when the rear end detector 5 for the first half detects the passage of the long narrow veneer 2b. At the same time, the detection signal is transmitted to the output circuit 9 for the first half, and the output circuit 9 for the first half is connected to the intermittent drive device 10a and the striking bar 10.
The upper surface holding is released by activating the first half release device 1 consisting of the first half section release device 1, and the long narrow veneer 2b is dropped and deposited at the rear end position of the first half section at the depositing place directly below.

In this case, the deposition movement with respect to the rear end position of the front half of the deposition place is repeated in the same way as the detection operation of the front end detector 4 for the front half described above, and the long narrow veneer 2b that has been dropped and deposited is at a predetermined height. When the overall level detector 12 is blocked from light by being piled up, the light receiver 12b of the overall level detector 12 inputs a detection signal to be lowered to the drive circuit 13 of the lifting table 11, and the drive circuit 13 As the lifting table 11 is lowered, a switching signal is sent to the first half deposition switching circuit 7 to switch the circuit again from the detection operation side of the rear end detector 5 for the first half to the detection operation side of the front end detector 4 for the first half. Communicate. Then, the deposition switching circuit 7 for the first half switches from the detection operation side of the rear end detector 5 for the first half to the detection operation side of the front end detector 4 for the first half, but with this switching operation, the first drive circuit 13 A prohibition circuit 14 consisting of a ratchet relay, a memory element, etc., whose output signal switches every time the detection signal to be lowered is input twice, prohibits the operation of the output circuit 9 for the first half. At the same time, a release signal for canceling the inhibition of the operation of the output circuit 9A for the second half is transmitted.

Therefore, since the operation of the output circuit 9A for the second half has been canceled, the veneer veneer 2, which is being conveyed by the top conveyor 13, is now installed before and after the first half and the second half of the stacking place. For the front end detector 4A for the second half, which determines the position of the front end of the second half of the deposition, and the rear end detector 5A for the second half, which determines the position of the rear end of the second half of the deposition, the second half consists of a photoelectric switch, a limit switch, etc. First, it passes through the rear end detector 5A for the second half, and when the rear end detector 5A detects the arrival of the narrow veneer 2, the detection signal detects whether the width is longer or shorter than a predetermined width. A length discrimination circuit 6A for the second half consisting of a timer, a shift register, a preset counter, etc. that discriminates based on time, and a ratchet relay that switches the detection operations of the front end detector 4 for the second half and the rear end detector 5 for the second half. The signal is input to the second half deposition switching circuit 7A consisting of the following.

The temporal length discrimination means by the length discrimination circuit 6A for the second half section uses a timer, for example, like the length discrimination circuit 6 for the first half section, and if the predetermined width is 100 m1 and the conveyance speed of the upper surface conveyor 3 is 60 m/min. The delay time of the timer is set at a position where the upper surface conveyor 13 sets up the narrow veneer 2 by 100 msec, which is the time required to transport the narrow veneer 2 by 100 mm. 80
If the input of the detection signal from the rear end detector 5A for the rear half is cut off in msec, the timer will not be set up, so this is a short narrow single plate 2a with a predetermined width of 100 m or less. If the input of the detection signal from the rear end detector 5A for the rear half is cut off after 120 msec, the timer has already been set up. It is determined that it is the veneer 2b. Further, the discrimination signal of the short narrow width veneer 2a discriminated by the length discrimination circuit 6A for the latter half section is applied to the short narrow width veneer 2a at approximately the center position between the front end position and the rear end position of the rear half part of the deposition place. is transmitted to the second half deposition position changing circuit 8A, which is composed of a timer, shift register, preset counter, etc., so as to fall and deposit, and the second half deposition position changing circuit 8A is connected to the second half length discrimination circuit 6.
The short width veneer 2a discriminated by temporarily storing and delaying the discrimination signal of the short width veneer 2a transmitted from A is located approximately in the center between the front end position and the rear end position in the latter half of the deposition area. The discrimination signal of the short narrow veneer 2a, which has been memorized and delayed at the time when it arrives at the position, is reproduced and transmitted to the output circuit 9A for the rear half, and the output circuit 9A for the rear half thereby operates an electromagnetic clutch brake, The release device 10A for the rear half consisting of an intermittent drive device 10Aa consisting of an air cylinder, etc. and a knock-down bar 10Ab is activated to release the upper surface holding, and a short swath is placed in the central position of the rear half of the deposition area directly below. The veneer 2a is dropped and deposited.

Furthermore, the discrimination signal for the long narrow veneer 2b discriminated by the length discrimination circuit 6A for the second half is transmitted to the stacking switching circuit 7A for the second half, and the stacking switching circuit 7A for the second half selects the stacking for the first half. Since the switching circuit 7 is switched to the detection movement side of the rear end detector 5A for the rear half, the rear end detector 5A for the rear half detects the passage of the long narrow veneer 2b at the same time. The signal is transmitted to the output circuit 9A for the second half, and the output circuit 9A is connected to the intermittent drive device 10Aa and the striking bar 10.
The release device 10A for the rear half made of Ab is activated to release the upper surface holding, and the long narrow veneer 2b is dropped and deposited at the rear end position of the rear half of the deposition place immediately below.

In this case, a large number of long narrow veneers 2b continue to be transported.
While the deposition switching circuit 7A for the second half is on the detection operation side of the rear end detector 5A for the second half, the long narrow veneer 2b is placed at the rear end position of the second half of the deposition place and the material is deposited by falling. As the operation is repeated, the width veneer 2b that has been dropped and deposited on the rear end position side of the rear half on the lifting table 11 is piled up to a predetermined height, and is moved from the rear end position of the rear half to the front end of the front half. When the overall level detector 12 consisting of a light emitter 12a, a light receiver 12b, etc., which detects the overall accumulation level emitted towards the position, is blocked, the light receiver 1 of the overall level detector 12 is blocked.
2b inputs a detection signal to be lowered to the 1 drive circuit 13 of the lift table 11;
At the same time, a switching signal is transmitted to the second half deposition switching circuit 7A to switch the circuit from the detection operation side of the rear end detector 5A for the second half to the detection operation side of the front end detector 4A for the second half. Then, the long narrow veneer 2b that has been conveyed to the front end detector 4A for the rear half is connected to the stacking switching circuit 7A for the rear half.
has already switched to the detection operation side of the front end detector 4A for the rear half, so the rear end detector 5A for the rear half is switched to the long narrow veneer 2.
b passes and the front end detector 4A for the rear half detects its arrival, and at the same time transmits the detection signal to the output circuit 9A for the rear half, and the output circuit 9A for the rear half outputs the intermittent drive device 1.
Release device 1 for the rear half consisting of 0Aa and knock-down bar 10Ab
0A is activated to release the upper surface holding, and the long narrow veneer 2b is dropped and deposited at the front end position of the rear half of the depositing place directly below.

In this case, the deposition operation for the front end position of the rear half of the deposition location is repeated in the same manner as the detection operation of the rear end detector 5A for the rear half described above, and the long narrow veneer 2b that has been dropped and deposited is at a predetermined height. When the overall level detector L2 is shielded from light by being deposited on the surface, the light receiver 12b of the overall level detector 1λ
inputs a detection signal to be lowered to the driving circuit 13 of the lifting table 11, and the driving circuit 13 lowers the lifting table 11 and sends the detection signal to the latter half stacking switching circuit 7A to the detection operation side of the front end detector 4A for the latter half. Rear end detector 4A for the rear half
A switching signal to switch the circuit again is transmitted to the sensing operation side.

However, the stacking switching circuit 7A for the second half is switched from the detection operation side of the front end detector 4A for the second half to the rear end detector 5A for the second half.
The circuit switches to the detection operation side, and along with this switching operation, the output signal is switched from the inhibition circuit 14 to the output circuit 9A for the second half, every time the detection signal to be lowered from the drive circuit 13 is input twice. A prohibition signal for prohibiting the operation of the output circuit 9A0 for the second half is transmitted, and conversely, the output circuit 9 for the first half
transmits a release signal to release the prohibition of its operation. At the same time as this switching operation, the stacking switching circuit 7 for the first half section is also switched to the detection operation side of the front end detector 4 for the first half section, so that the narrow veneer 2 conveyed by the upper surface conveyor 3 is placed again at the front end position of the first half section. After that, each time the drive circuit 13 lowers the lifting table after the pile is deposited to a predetermined height, the position of the rear end of the first half, the rear end position of the second half, and the front end position of the second half are changed. The deposition position is repeatedly moved in this order, and the falling deposition operation is repeated.

It should be noted that the order of movement of the stacking and stacking positions may be other than the order listed above, but it is preferable to set the movement distance to the minimum as in the above embodiment.

Further, the short width veneer 2a is discriminated by the length discrimination circuit 6 for the first half and the length discrimination circuit 6A for the second half, and the stacking position changing circuit 8 for the first half and the stacking position changing circuit 8A for the second half 5 At the sides of the central position where the deposition location has been changed to the central position of the first half and the second half due to the delay operation, there is a position corresponding to the total deposition level detected by the overall level detector 12. A level detector 1 for the first half consists of a light emitter 15a and a light receiver 15b, etc., which detect the accumulation level of the short narrow single plate 2a0), and a level detector for the second half consists of a light emitter 15Aa, a light receiver 15Ab, etc. A detector LiΔ is installed, and when a large number of short narrow veneers 2a are conveyed and dropped and piled up, the level detector 15 for the first half and the level detector 15A for the second half are shielded from light. Detector 15 and level detector 15 for the rear half
The light receivers 15b and 15Ab of A transmit a discrimination body stop signal to the length discrimination circuit 6 for the front half and the length discrimination circuit 6A for the rear half, so that the subsequent short narrow veneer 2a is connected to the long narrow veneer 2a. As in the case of the plate 2b, in addition to temporarily dropping and depositing on the side of the deposition switching circuit 7 for the first half and the deposition switching circuit 7A for the second half that are operating at that time, the length discriminating circuit 6 for the first half and the second half are deposited temporarily. The discriminator stop signal from the length/shortness discrimination circuit 6A is transmitted from the light emitters 15a, 15Aa of the first half level detector 15 and the second half level detector 15A to the light receivers 15b, 1.
It is controlled so that it returns to normal when the 5Ab is irradiated with the light beam again. Furthermore, a forced release detector 16 for the first half and a forced release detector 16 for the second half, which are comprised of a photoelectric switch, a limit switch, etc., are located at a position slightly away from the rear end detector 5 for the first half and the rear end detector 5A for the second half on the carry-in side. Release detector 16
A is installed to prevent problems such as material damage due to the close spacing of the plates.

That is, the narrow veneer 2 transported by the transport conveyor 1
Since there is a required time limit for the dropping operation of the first half release device 10 and the second half release device 10A that release the top surface holding, for example, when the falling pile is deposited at the front end position of the first half and the second half of the pile, The interval between the preceding short width veneer 2a or long width veneer 2b and the following short width veneer 2a or long width veneer 2b is determined by the position of the rear end of the first half and the second half of the pile. There must be at least a predetermined distance l from the center to the central position where the short width veneer 2a falls and accumulates, or a predetermined distance L from the rear end position to the front end position of the first half and the second half of the stack. The reason is the short veneer veneer 2a that precedes it.
Or, if the interval between the long narrow veneer 2b and the next short narrow veneer 2a or the long narrow veneer 2b is less than the predetermined distance l or L, the preceding short narrow veneer 2a is the front half. When the deposition position is changed to the center position by the delay operation of the deposition position change circuit 8 for the first half and the second half deposition position change circuit 8A,
Or, when the long width veneer 2b is detected by the front edge detector 4 for the front half and the front edge detector 4A for the rear half, the next short width veneer 2a or long width veneer 2b has already been detected after the front edge detector 4 for the front half and the front edge detector 4A for the rear half. It is now passing through the end detector 5 and the rear end detector 5A for the rear half.

Therefore, at this time, when the above-mentioned release device 1 for the first half and the release device 10A for the rear half are knocked down, the upper surface holding of the preceding short width veneer 2a and long width veneer 2b is released. At the same time, the upper surface of the next short narrow veneer 2a or long narrow veneer 2b passing through the rear end detector 5 for the front half and the rear end detector 5A for the rear half is held by the release device 10 for the front half and the rear end detector 5A for the rear half. It gets caught in the knock-down bars 10b and 10Ab of the release device 10A for the rear half and is released all at once, so it may fall to an unspecified place, or it may be held on the upper surface with a part of the tip hanging down. There was a problem in that the overall appearance of the pile was extremely disordered due to transportation. Therefore, in order to eliminate this problem, the preceding short narrow veneer 2a and long narrow veneer 2b pass through the forcible release detector 16 for the front half and the forcible release detector 16A for the rear half, and then When detected by the rear end detector 5 for the rear end and the rear end detector 5A for the rear end, the detection signals are transmitted to the storage circuit 17 for the front half and the storage circuit 17A for the rear half, which are composed of a memory element, a ratchet relay, etc. It is temporarily stored that the preceding short width veneer 2a and long width veneer 2b are being transported.

Next, the next short width veneer 2a or long width veneer 2b is conveyed within a predetermined interval l or L, and the forcible release detector 16 for the front half and the forced release detector 16A for the rear half are transported.
When detected by the inhibition circuit 14, the detection signal is immediately transmitted to the first half output circuit 9 and the second half output circuit 9A via the first half memory circuit 17 and the second half memory circuit 17A. The first half output circuit 9 and the second half output circuit 9A on the side where the prohibition signal has been released activate the intermittent drive devices 10a and 10Aa of the first half release device 10 and the second half release device 10A to take the lead. The short narrow width veneer 2a and the long narrow width veneer 2b are forcibly dropped and deposited directly below even during their conveyance. Further, the storage in the first half memory circuit 17 and the second half memory circuit 17A is cleared by the output signals of the first half output circuit 9 and the second half output circuit 9A.

Therefore, each time the narrow veneer 2 is detected by the rear edge detector 5 for the front half and the rear edge detector 5A for the rear half, the memory circuit 17 for the front half and the memory circuit 17A for the rear half usually start storing. However, the interval between the narrow width veneers 2 is equal to or larger than the predetermined interval 2 or L, and the normal short width veneer 2a is deposited at the central position of the first half and the second half of the pile, or at the long narrow width. Veneer 2
As long as the drop is deposited at the front end position or the rear end position of the first half and the second half, which is the deposition location of b, the first half output circuit 9 and the second half output circuit 9A output the first half memory. A memory release signal is transmitted to the circuit 17 and the second half memory circuit 17A, so that the memory in the first half memory circuit 17 and the second half memory circuit 17A is always cleared. As mentioned above, according to the present invention, since the construction method does not involve cumulatively stacking small width veneers 2 cut to a specified width, very small width veneers 2, which cannot be used in the subsequent process, are placed at the front and rear ends of the stack. There is no reduction in yield due to cumulative cutting of the board, and there is no possibility that such extremely small width veneers will fall or hang diagonally and become messy and piled up, and moreover, it can be cut to a specified width. Among the cut narrow width veneers 2, the narrow width veneers 2b having a longer width than a predetermined width are deposited at the front end position or the rear end position of each of the first half and the second half of the stack that divides the stacking area into two, and The small width veneer 2a, which is shorter than the width, is controlled so that it is deposited at the central position of the first half and the second half of the pile, which divides the deposition place into two, so that the front and rear ends of the subdivided pile are We started with an automatic deposition device for narrow veneer plates, which was constructed to improve the work efficiency of subsequent processes by forming the entire subdivided pile into a nearly horizontal pile shape. This is what we could have provided.

[Brief explanation of drawings]

The drawings show an example of the implementation of the present invention, in which FIG. 1 is a side view and FIG. 2 is a sectional view taken along the line AA in FIG. 1. 2, 2a, 2b...Small width veneer, 3...
Top conveyor, 4,4A...Front end detector, 5,5A...Rear end detector, 6,6A...
...Length/shortness discrimination circuit, 7,7A...Deposition switching circuit, 8,8A...Deposition position change circuit, 10,10
A...Release device, 11...Elevating table, 12...General level detector, 15...
...Level detector for the first half, 15A... Level detector for the second half.

Claims (1)

[Claims] 1. A top conveyor that sticks or suction-holds the narrow veneer that is cut to a specified width and is transported from the top and continues the conveyance, and the sticking of the narrow veneer that is conveyed by the top conveyor. Or, by releasing the suction and holding and dividing the stack into the first half and the second half, and dropping and depositing the stack, a first half release device and a second half release device are installed in series before and after the first half and the second half are released, and the first half of the stack is removed by the first half release device. A front end detector for the first half and a rear end detector for the first half, which separately detect the front end position and the rear end position of the narrow veneer plate that is dropped and deposited and control the stacking operation; A front end detector for the second half and a rear end detector for the second half that separately detect the front end position and rear end position of the narrow veneer that is dropped and deposited in the latter half of the pile by the release device and control the stacking operation. and a narrow veneer conveyed by the upper surface conveyor, which discriminates whether the narrow width veneer is longer or shorter than a predetermined width by the passage time of the rear end detector for the first half and the rear end detector for the rear half. A short width veneer shorter than a predetermined width discriminated by the length discrimination circuit for the first half and the length discrimination circuit for the second half, and the length discrimination circuit for the first half and the length discrimination circuit for the second half are used as the front ends of the first half and the second half of the pile. The detection signal of the narrow veneer detected by the rear end detector for the front half and the rear end detector for the rear half is appropriately delayed so as to fall and accumulate at approximately the center position between the rear end position and the rear end position. A stacking position change circuit for the front half and a stacking position changing circuit for the rear half that respectively transmit information to the release device for the front half and the release device for the rear half, and the release device for the front half and the release device for the rear half control the lifting table directly below. an overall level detector for controlling the lowering of the lifting table by detecting the overall accumulation level of the narrow veneer plate that is dropped and deposited in two halves into a front half and a rear half; and a deposition position changing circuit for the first half. And when the accumulation level at the center position of the narrow veneer plate deposited is detected by the accumulation position changing circuit for the latter half, and exceeds the overall accumulation level detected by the overall level detector, Lowering operation of the lifting table controlled by the level detector for the first half and the level detector for the second half, which temporarily suspends activation of the length discrimination circuit for the first half and the length discrimination circuit for the second half, and the level detector for the whole. a stacking switching circuit for the first half which alternately switches detection operations by the front end detector for the first half and the rear end detector for the first half each time, and each time the lowering operation of the lifting table is controlled by the overall level detector; A stacking switching circuit for the second half that alternately switches detection operations by the front end detector for the second half and the rear end detector for the second half, and a lowering operation of the lifting table controlled by the overall level detector enters twice. From a prohibition circuit that alternately switches the stacking operation of the first half and the second half by prohibiting the output from the output circuit for the first half to the release device for the first half and the output from the output circuit for the second half to the release device for the second half. An automatic deposition device for narrow veneer.