JPS5842816B2 - It's hard to tell what's going on. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses a veneer cutting machine to cut joints, which are defective parts of veneer,
Mark cracks, etc. with chalk of a color different from the color of the veneer fabric, project diffused light onto the surface of the veneer, and measure the reflectance based on the color difference between the areas marked with chalk etc. and the areas not marked. The present invention relates to a method for removing a defective portion of a veneer, which extracts the difference between the two as an electric signal, and uses this electric signal to cut a portion marked with chalk or the like.

Conventional veneer clippers cut and remove defective parts such as knots, cracks, and rough edges by detecting these defective parts using multiple detection terminals arranged in a row parallel to the cutting edge line of the cutter. This is done using an automatic method of cutting.

As a detection terminal, a roller is brought into contact with the surface of the veneer to detect defective parts based on the thickness of the veneer, or photoelectric detectors are placed above and below the conveying surface of the veneer to block light. A means of detecting a defective part by opening is employed.

However, the detection method using these detection terminals has the drawback that there is no difference in thickness, such as a raw part or a comb, and defective parts that do not transmit light cannot be detected.

In addition, it is impossible and uneconomical to arrange the detection terminals across the gold plate of the veneer without any gaps, so three to five detection terminals are usually used for the entire white of the veneer. ,
In this case, there is a drawback that the portion where the detection terminal does not exist cannot be detected.

The method of the present invention was developed in order to eliminate these drawbacks of the conventional methods, and involves marking defective areas such as raw parts or combs with chalk etc. that cannot be detected by the conventional method. The attached part is automatically cut and removed, and if used in conjunction with the automatic cutting by the detection terminal, any defective part of the veneer can be removed, improving product quality. This has brought great benefits to the plywood industry by improving the gable end (previously, veneers with undetectable defective parts were discarded) and improving clipper efficiency (eliminating loss in veneer sorting, etc.). It makes a contribution.

The method of the invention will be explained below by means of an example shown in the drawings.

The conveyor 1 conveys the veneer A in a direction perpendicular to its fibers, and following the conveyor 1, a feed conveyor 2, a cutting device 3, a feed conveyor 4, and a discharge conveyor 5 are arranged in this order.

The cutting device 3 is composed of a blade 6, a receiving blade 7, and an actuator 8 for the blade 6. The actuating device 8 is actuated by an electric signal, which will be described later, and the cutting blade 6 and the receiving blade 7 cut the veneer A into its fibers. It cuts in the direction.

9 is a sensor, and the sensor 9 is disposed at an appropriate position on the conveyor 1, but as shown in FIG. 2, the optimum position is above the end edge of the veneer A conveyed by the conveyor 1.

The sensor 9 is composed of a light emitter 11 and a light receiver 12 housed in a box 10. The light emitter 11 is located on the loading side of the conveyor 1, and the light emitter 11 and the light receiver 12 are separated by a partition plate 13 that does not allow light to pass through. The light emitting chamber 14 and the light receiving chamber 15 are respectively housed in a light emitting chamber 14 and a light receiving chamber 15 which are partitioned by.

The light projector 11 is a light source that emits stable diffused light, and projects the diffused light onto the surface of the veneer A passing below through a glass window 16 attached to the lower surface of the light projection chamber 14.

The light receiver 12 is assumed to generate an electromotive force by irradiation with light such as a phototransistor, and the direction of its light receiving axis B is generally directed onto the surface of the single plate running on the conveyor 1 directly under the projector 11, and It is arranged so that it has an inclination angle θ (20° to 45°) with respect to the conveying surface of 1, and the reflected light projected from the projector 11 onto the veneer surface and diffusely reflected from the veneer surface is passed through the lower surface of the open light receiving chamber. It is configured to receive light.

Worker C stands in front of the sensor 9 on the side of the conveyor 1 and monitors the defective part of the veneer A. For example, if he finds an upper joint on the veneer A and wants to cut and remove it, he Sensor 9 at the end of the veneer so that the part is cut and removed exactly.
Two marks L1 and L2 are made with chalk or the like in a color different from the color of the veneer fabric at the portion passing under the veneer.

To explain the principle of how the sensor 9 detects a region marked with chalk or the like of a color different from the color of the veneer fabric, the diffused light projected onto the veneer surface by the projector 11 is diffusely reflected on the veneer surface. However, the reflectance of this light differs depending on the color of the veneer surface, and the reflectance reflected to the light receiver 12 differs between the part marked with chalk or the like and the part of the veneer fabric. There is also a difference in the electromotive force generated in the device 12, and this difference in electromotive force is extracted as an electrical signal.

Now, to explain detection based on this principle using white chalk, for example, as shown in Fig. 2, marks L1 and L2 on veneer A are marked with white chalk,
Light receiver 1 when this single plate A passes through the sensor 9
Figure 3 shows the strength of the electromotive force generated in Figure 2. In Figure 3, the complicated polygonal line P indicates the electromotive force, and the two-dot chain line indicated by Q indicates the average color of the fabric of veneer A. Indicates the reference value of electromotive force.

Point PL1 showing an electromotive force much stronger than the reference value Q of electromotive force
and PL2 are those that occurred at the marks L1 and L2 made with white chalk, respectively,
The differences in electromotive force between points PL1 and PL2 and the reference value Q were 50 mv and 45 mv, respectively.

In this way, the electromotive force generated by the reflected light from the area marked with white chalk is much stronger than the electromotive force generated by the reflected light from the fabric part of the veneer. The difference in electromotive force with the fabric part is extracted as an electrical signal.

This difference in electromotive force is determined under the worst condition of the veneer, for example, when using white chalk, the difference from the standard value of electromotive force shown as Q, considering the part of the fabric of the veneer whose tone is closest to white If the setting is made so that a signal is output when an electromotive force of 30 mv or more is generated, the signal can be extracted only from the part marked with white chalk.

This extracted electrical signal is transmitted to the actuating device 8 via a timer.
The electric signal is transmitted to the electric signal, and the veneer part where the electric signal is emitted is cut by the knife 6.

Since the electromotive force generated in a light receiver such as a phototransistor is weak, it is amplified several hundred times and extracted as an electrical signal.

This marking on the surface of the veneer with chalk may be done with chalk or other suitable material such as magic ink, and the color may be red or other appropriate color.If it is not the same color as the material of the veneer, the reflection Since the rates are different, they can be used similarly.

The detector 17 is used to detect defective parts, cracks, and knots on the edges of veneers, which have been commonly used in the past, and cut and remove those parts. It is arranged in a direction perpendicular to the direction, that is, parallel to the cutting edge line of the cutter 6, and a light emitter/receiver is arranged between the conveying surface of the veneer, and a signal is emitted when the detector 17 is shielded by the veneer and released. The signal is transmitted to the actuating device 8 of the cutter 6 via a timer, and when the detected part reaches the lower part of the cutter, that part is cut. If used in combination with this detection device, all defective parts of the veneer can be removed.

As described above, the present invention provides a veneer cutting machine that cuts and removes defective parts while conveying the veneer in a direction perpendicular to the fibers of the veneer. A mark is made with chalk, etc., and diffused light is projected onto the surface of this veneer, and the difference in reflectance due to the difference in color between the part marked with chalk etc. and the part not marked is used to extract it as an electrical signal. Because of this, it is possible to reliably detect defective parts such as upper knots and combs that could not be detected using conventional methods, and automatically cut and remove them, which can contribute to improving product quality and end closure. This makes a great contribution to the plywood industry.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, the first being a side view and the second being a side view.
The figure is a partial plan view of FIG. 1, and FIG. 3 is a graph showing changes in electromotive force generated in the light receiver. 1...conhairer, 2...feeding conveyor, 3
... Cutting device, 4... Delivery conveyor, 5...
・Unloading conveyor, 6... cutlery, 7... receiving blade, 8.
... Actuation device, 9... Sensor, 10... Box body, 1
DESCRIPTION OF SYMBOLS 1... Emitter, 12... Light receiver, 13... Partition plate, 14... Light emitting chamber, 15... Light receiving chamber, 16... Glass window, 17... Detector, A ...Single board.

Claims (1)

[Claims] 1. A conveyor that conveys the veneer in a direction perpendicular to its fibers.In a veneer cutting machine that is equipped with a cutting device behind the conveyor that cuts the veneer in the direction of its fibers, the conveyor conveys the veneer in a direction perpendicular to its fibers. A sensor consisting of a light projector that projects diffused light onto the veneer surface and a light receiver such as a phototransistor that catches the reflected light from the veneer surface is installed. Mark with chalk, etc. of a color different from the color of the fabric,
The electromotive force of the light receiver is caused by the difference in reflectance between the diffused light projected onto the surface of the veneer by the light emitter of the sensor and reflected between the colored part marked with the chalk or the like and the colored part of the veneer fabric. A method for removing a defective portion of a veneer, in which the difference between the two is extracted as an electric signal, the electric signal is transmitted to the cutting device via a timer, and the portion marked with chalk or the like is cut.