JPH0112641B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Objective of the Invention) The present invention aims to improve the cutting speed and discharge speed caused when a veneer veneer cut and discharged by a veneer race equipped with a knife and a nose bar is directly conveyed to a subsequent process. The purpose of this is to automatically correct the speed difference and eliminate the decrease in veneer yield and process efficiency caused by breakage or bending of the cut veneer due to the speed difference.

(Structure of the Invention) As illustrated in an example of its implementation, the present invention forms an appropriate space on the slope 7a of the planer stand 7 that supports the knife 6 of the veneer lace 1 and on the carry-out conveyor 8 that is connected to the slope 7a. However, the device is arranged so that the cut veneer 4 is placed in a tensile state or a slack state in the space. In addition, the veneer race 1 has a speedometer generator 11 that can measure the rotation speed of the spindle 10 that rotates the log 9, a variable resistor that can measure the position of the planer stands 7 and 3, a variable transformer, etc., and position indexes. A uniform speed controller 14 is provided which transmits a speed command signal to a variable speed motor 13 that drives the delivery conveyor 8 by calculating the cutting speed of the veneer lace 1 in combination with the veneer lace 1. The cut veneer 4 is conveyed to the subsequent process at a cutting speed substantially equal to the cutting speed of the veneer lace 1 (meaning that the conveying speed of the conveyor 8 is synchronized with the cutting speed of the veneer lace 1). However, there is actually a difference between the cutting speed of the veneer race 1 and the unloading speed of the unloading conveyor 8 due to the calculation error of the uniform speed controller 14 and the difference in elongation rate of the material of the veneer veneer immediately after cutting. occurs and the slope 7a of the planer stand 7 on the knife 6 side
In addition, since the cut veneer 4 is in a tensile state (see Fig. 2) or in an excessively slack state (see Fig. 4) in the space above the unloading conveyor 8, the slight It is rare that the loose state remains stable for long periods of time. Therefore, it is necessary to correct the unloading speed of the unloading conveyor 8, but the excessive slack state is an abnormal situation in uniform speed control.
Since this can be easily eliminated by manually readjusting the speed controller 14, it is possible to eliminate this and automatically detect and correct the range from the slight slack state to the tensile state. A slack detector 15 consisting of a reflective limited-distance photoelectric switch or the like is placed facing the space so that a signal can be transmitted, and when the tensile state of the cut veneer 4 reaches its limit, slack is detected by ON/OFF output. The device is configured to transmit a signal or to transmit an analog output slack detection signal steplessly between a slight slack state and a maximum tension state. Further, the slack detection signal detected by the slack detector 15 is superimposed on the speed command signal sent from the speed controller 14 to the variable speed motor 13, and is sent to an appropriate amount, for example, at a conveyance speed of about 50 to 100 meters per minute. In this case, a correction controller 16 is installed so as to be able to correct the deceleration by an appropriate amount of about 5 to 10 meters per minute, and is inserted between the speed equalization controller 14 and the variable speed motor 13 to control the speed of the unloading process. While automatically detecting the slack in the cut veneer 4, the deviation in the constant speed control is automatically corrected so that a slight slack state as illustrated in FIG. 1 is always maintained. There are various methods for detecting the loosening of the cut veneer 4 during the unloading process using the above-mentioned slack detector 15, such as a photoelectric method, a mechanical method, an ultrasonic method, and a stray capacitance detection method. More specifically, the reflective limited distance type photoelectric switch 15a illustrated in FIG. A device that is capable of detecting slack in the cut veneer 4 in a non-contact state by transmitting an ON/OFF output when the veneer 4 is reached, or by transmitting an analog output steplessly within the detection area. It is.

Next, the present invention also provides an erroneous tension detection signal when the slack detector 15 detects an excessive slack state of the cut veneer 4 caused by an abnormal situation in the uniform speed control as illustrated in FIG. In response to an unexpected situation in which the signal output is transmitted, a signal output that lasts for a limited time between the slack detector 15 and the correction controller 16 is distinguished from a signal output that does not last for a limited time, and the latter does not persist for a limited time. A time controller 19 consisting of a timer or the like is inserted into the control circuit so that the signal output, that is, if the signal output is intermittent due to excessive slack as illustrated in FIG. 4, the signal output can be cut off and eliminated. This makes it possible to prevent the generation of erroneous signals.

(Effects of the Invention) As described above, the present invention provides a space in which the tensile state and slack state caused by the discrepancy in uniform speed control between the cutting speed and the unloading speed of the cut veneer discharged from the veneer lace can be safely stored and released. is formed on the slope of the plane stand on the knife side and on the carry-out conveyor, and the tensile state and slack state of the cut veneer in the space,
For the most frequently occurring tensile state, the lowest position of the slack state, that is, the maximum value of slack, is automatically detected by the slack detector, and the control is always controlled only in the deceleration direction, and the control area is controlled by the conventional photoelectric method, Since it can be used to a greater extent than control methods such as mechanical methods, ultrasonic methods, and stray capacitance detection methods, control can be extremely simplified, there is no hunting phenomenon, and the response of the variable speed motor can be improved. This has the effect of completely eliminating breakage and bending of the cut veneer due to the speed difference between the cutting speed and the unloading speed.

[Brief explanation of drawings]

The figure shows an example of implementation of the present invention,
Fig. 1 is a side view, Fig. 2 is an explanatory diagram of the cut veneer in a tensile state, Fig. 3 is an explanatory diagram of the operation of the slack detector, and Fig. 4 is an explanatory diagram of the cut veneer in an excessively slack state. . 2... Nose bar, 3, 7... Planer stand, 4... Cutting veneer, 6... Knife, 8... Carrying out conveyor, 10... Spindle, 13... Variable speed motor, 14... Uniform speed controller,
15... Slack detector, 15a... Reflective limited distance type photoelectric switch, 16... Correction controller, 19... Time controller.

Claims (1)

[Scope of Claims] 1. An appropriate space is provided between the slope of the knife-side planer stand and the carry-out conveyor connected thereto, and the speed of the variable speed motor that drives the carry-out conveyor is determined based on the rotational speed of the spindle and the position of the plane stand. In a veneer race that equalizes the cutting speed of the veneer and the speed of unloading the veneer, the control circuit is provided with an equalizing speed controller that sends a command signal, and the veneer race is provided at a position near the veneer discharge end of the knife-side planer stand. The control circuit includes a correction controller that is provided with a slack detector that detects a slack state of the veneer, and that corrects the speed command signal of the speed equalization controller to the speed reduction side by an appropriate amount based on the slack detection signal from the slack detector. A uniform speed correction device for a veneer race characterized by being provided inside. 2. A patent in which a time controller is provided in the control circuit of the slack detector and correction controller to discriminate and eliminate an erroneous signal from the slack detector transmitted from the excessive slack of the cut veneer formed in the space. A uniform speed correction device for a veneer race according to claim 1.