JP3169697B2 - Pressing method of backup roll in veneer lace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for pressing a backup roll in veneer lace.

[0002]

2. Description of the Related Art Conventionally, when turning a log using a veneer lace, even if the log is bent in either direction, there is a problem that the thickness of the veneer to be cut is not uniform, or the log is vibrated. However, since uneven thickness and rough skin may occur, the veneer lace is equipped with an appropriate number of backup rolls to back up the logs, preventing bending and vibration of the logs. Attempts have been made for a long time.

As a typical specific example of the conventional method of pressing a backup roll, as disclosed in, for example, "Equilibrium type round stripping machine" (Japanese Utility Model Publication No. 30-13599), a stepping of a plane table is performed. And a so-called interlocking follow-up system in which the backup roll moves forward in the centering direction of the raw wood, and disclosed in, for example, "Veneer veneer veneer veneer" (JP-B-46-42518). As described above, regardless of the stepping movement of the plane table, always with a predetermined urging force, a method of forcibly urging the backup roll in the direction of centering the log, a so-called forced pressurization method, may be mentioned.
Each of these known systems has advantages and disadvantages.

[0004]

More specifically, it is well known that the rigidity increases and decreases in proportion to the thickness of the log, but in the former interlocking follow-up system, the backup roll has a stepped surface of a plane table. Since most of the cross section of the log is turned according to the spiral curve (so-called Archimedes spiral curve) because it moves forward following the feed, it is stable without excess or shortage regardless of the change in the thickness of the log. It has the advantage of functioning effectively. However, before most of the cross section of the log is turned in accordance with the spiral curve, the backup roll does not abut on the concave portion on the outer periphery of the log, so that the function is extremely uncertain.

[0005] On the other hand, in the latter forced pressurizing method, the backup roll is forcibly urged in the centering direction of the raw wood always with a predetermined urging force regardless of the feed of the plane table. Theoretically, even before most sections are turned to follow a spiral curve, the backup roll will advance and retreat along the irregularities on the outer perimeter of the log, and will function adequately if not necessarily enough However, in reality, as described later, there is a defect that it is extremely difficult to properly set the urging force, so that the function is extremely unstable.

That is, if the above-mentioned biasing force is set to a relatively small force, for example, a small force that is adapted to the rigidity when the log is turned to near the minimum diameter (peeling diameter), macroscopically,
The backup roll is easy to smoothly advance and retreat along the irregularities on the outer circumference of the raw wood, and when the backup roll advances from the convex part on the outer circumference of the raw wood to the concave part, there is no particular problem microscopically, Microscopically, only when the backup roll retreats from the concave part on the outer periphery of the log to the convex part, due to the effect of inertia force, the backup roll floats in the air for a moment away from the convex part on the outer periphery of the log, and immediately near The phenomenon of re-contacting with impact is likely to occur, and consequently, the adverse effect of promoting vibration is caused.

On the contrary, if the biasing force is set relatively strong, the phenomenon that the backup roll floats in the air for a moment can be suppressed, but the backup roll retreats from the concave part on the outer periphery of the log to the convex part. At the time of cutting, the log tends to be excessively backed up by the influence of the inertia force and the biasing force, and the phenomenon that the log is intermittently excessively pressed toward the veneer for single veneer occurs, which also promotes vibration. In addition, if the setting of such a strong biasing force is continued as it is, when the log is turned to near the minimum diameter, a phenomenon occurs in which the bending occurs toward the single-plate cutting blade side. In addition, a disadvantage that the thickness of the veneer to be cut becomes uneven is also caused.

Therefore, the latter method has the disadvantage that the function becomes extremely unstable before most of the cross section of the log is turned according to the spiral curve. Since there is no need for a mechanism for synchronizing with the step-by-step movement, it has the advantage of a relatively simple and simple structure compared to the former interlocking follow-up method, but its practicality and usefulness is the former interlocking follow-up method. As unsatisfactory as the method.

[0009]

SUMMARY OF THE INVENTION The present invention, as a means for solving the disadvantages of the above-mentioned known system, is specifically designed to move forward in the centering direction of a log following a stepping movement of a plane table when required. Using a pneumatic cylinder, the backup roll is held so as to be able to move forward and backward, and when the backup roll comes into contact with the outer peripheral surface of the raw wood turned by the veneer, the stroke limit of the pneumatic cylinder is reached. Set the relative position between the pneumatic cylinder and the plane table to retreat, and the backup roll smoothly moves along the irregularities on the outer circumference of the log, at least until most of the cross section of the log is turned following the spiral curve. We propose a pressing method that introduces compressed air of an appropriate pressure to the pneumatic cylinder to the extent that it can advance and retreat.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to an embodiment illustrated in the drawings. For convenience, a spiral curve around a log in the course of turning is approximately shown.

FIG. 1 is an explanatory side view of a veneer lace used in the embodiment of the present invention, and FIGS. 2 to 4 are explanatory views of the operation of a backup roll.

In FIG. 1, reference numeral 1 denotes a cutting blade 1a for cutting a single plate, and a plurality of divided pressure bars 2a whose cutting edge can freely move forward and backward.
Is a pressure bar base 2 provided at appropriate intervals in a direction parallel to the cutting edge of the single-plate cutting blade 1a, a plane table including an outer peripheral driving mechanism 3 described later, and a stepping mechanism 4 described later.
With the operation of (1), it is advanced and retracted in the direction of the arrow shown.

Reference numeral 3 denotes an outer peripheral drive roll 3b provided with a plurality of needle-shaped disk-shaped drive members 3a at appropriate intervals in the axial direction.
An outer peripheral drive mechanism configured using a constant-speed drive source 3c or the like composed of a three-phase induction motor or the like.
2 supplies most of the power required for cutting.

Reference numeral 4 denotes a feed screw 4 composed of a ball screw or the like.
a, a stepless variable speed type feed mechanism constituted by a variable speed drive source 4b composed of a servo motor and the like, a position detector 4c composed of a rotary encoder and the like, and is controlled by a control device 13 which will be described later. Then, the plane table 1 is moved forward and backward in the direction indicated by the arrow.

Numeral 5 is a hollow cylindrical backup roll. Both ends provided with bearings 5a are respectively held by a pair of left and right pneumatic cylinders 6 described later. After the operation is performed, at least until the cross section of most of the log 11 is turned along the spiral curve, it is urged in the direction indicated by the arrow.

Reference numeral 6 denotes a pair of left and right pneumatic cylinders integrally attached to the movable support frame 7, which is integrally operated with the support frame 7 in the direction of the arrow shown in FIG. And the appropriate pressure (the backup roll 5 can smoothly advance and retreat along irregularities on the outer periphery of the raw wood 11), which is introduced via a pressure-reducing valve 14 with relief and / or an electromagnetic on-off valve (not shown) or the like. Of compressed air (in other words, a pressure at which a relatively small urging force can be applied to the backup roll 5) until at least the cross section of most of the log 11 is turned according to a spiral curve. Urges the backup roll 5 in the direction indicated by the arrow.

Reference numeral 8 denotes a moving screw 8 composed of a ball screw or the like.
a, a stepless variable-speed moving mechanism configured by using a variable-speed drive source 8b composed of a servomotor and the like, a position detector 8c composed of a rotary encoder and the like, and obtained under the control of a control device 13 described later. The pneumatic cylinder 6 and the support frame 7 are reciprocated in the direction of the arrow shown in the figure.

Reference numeral 9 denotes a rotation speed detector 9a comprising a rotary encoder or the like, and a variable speed drive source 9b comprising a DC motor or the like.
A raw wood rotating mechanism configured by using the above-described method, and under the control of the control device 13 described later, at least before the outer circumference driving mechanism 3 starts driving the outer circumference of the raw wood 11, a certain outer circumference by the outer circumference driving mechanism 3 The spindle 10 has a rotation speed that increases or decreases according to the diameter of the log to match the driving speed.
The raw wood 11 is rotated (idle) through.

Reference numeral 13 denotes a control device, which is the outer peripheral drive mechanism 3, the step feed mechanism 4, the moving mechanism 8, and the log rotation mechanism 9.
The rotation of the outer peripheral drive mechanism 3 and the log rotation mechanism 9 are controlled so that the rotation of the outer peripheral drive roll 3b and the rotation of the spindle 10 do not conflict even if the thickness of the log 11 changes. At the same time, it is important to control the synchronous operation of the stepping mechanism 4 and the moving mechanism 8 in association with each other as described later.

That is, the control device 13 causes the pneumatic cylinder 6 and the support frame 7 to follow the feed of the plane table 1 by the feed mechanism 4 from the start of turning in principle (exceptions will be separately described later). The moving mechanism 8 is operated synchronously so as to move forward in the center direction.
When the backup roll 5 comes into contact with the outer peripheral surface of the raw wood 11 turned by the veneer cutting blade 1a, a specific relative position such as retreating to the stroke limit of the pneumatic cylinder 6 is set. It controls to operate synchronously so as to be maintained.

The present invention is carried out using, for example, a veneer race configured as described above. Initially, as shown in FIG. 1, the backup roll 5 is at a position advanced to the stroke limit of the pneumatic cylinder 6. However, based on the control of the control device 13, the pneumatic cylinder 6 and the support frame 7 move forward in the centering direction of the log following the step feed of the plane table 1, and eventually come into contact with the outer periphery of the log 11. That is, since the compressed air introduced into the pneumatic cylinder 6 is set to an appropriate pressure, even if most of the cross section of the log 11 is not turned according to the spiral curve, the backup is performed. The roll 5 smoothly advances and retreats along the irregularities on the outer periphery of the log 11.

As shown in FIG. 2, for example, when the backup roll 5 comes into contact with the outer peripheral surface of the log 11 turned by the veneer 1a, the pneumatic cylinder 6
, The back-up function is fully performed even though the biasing force of the pneumatic cylinder 6 is relatively weak, and for example, as shown in FIG. When it is located in a concave portion on the outer periphery of the log 11 that has not been turned by the cutting tool 1a, it is biased by the pneumatic cylinder 6 to advance ahead of the stepping of the plane table 1 and contact the concave portion. Therefore, the backup function is exhibited, though not always enough.

In addition, the pneumatic cylinder 6
Is relatively weak, and when the backup roll 5 retreats from the concave portion on the outer periphery of the log 11 to the convex portion, the log 11 is excessively backed up, and the log 11 is intermittently veneered. Since the phenomenon of excessive pressing toward the cutting blade 1a hardly occurs, and the backup roll 5 can only retreat to the stroke limit of the pneumatic cylinder 6,
Although the biasing force of the pneumatic cylinder 6 is relatively weak, the probability that the phenomenon of floating in the air for a moment immediately after the backup roll 5 retreats from the concave portion on the outer periphery of the log 11 to the convex portion becomes extremely small. As a result, there is almost no possibility that the adverse effect of promoting vibration is caused.

Of course, as shown in FIG. 4, after all cross sections of the log 11 have been turned following the spiral curve, the backup roll 5 always retreats to the stroke limit of the pneumatic cylinder 6, and the plane table 1 is moved forward. Therefore, it is natural that the backup function is exhibited stably without excess or deficiency regardless of the change in the thickness of the log 11, and in general, compared with any known method. Also, the log 11 can be more reliably and stably backed up.

It should be noted that the number of backup rolls is not limited to one as in the above-described embodiment, and two or more backup rolls may be provided as necessary, and the present invention may be implemented with a minimum of one roll. It is effective accordingly, and its length is at least in the central part 1 in the axial direction of the log.
Although it is preferable to set the length to be in contact with / 3, it is not necessarily limited. If necessary, the length may be divided into a plurality in the axial direction, and the present invention may be implemented separately. However, in any case, in order to reduce the influence of the inertial force as much as possible, it is desirable to use a light and strong structure such as the hollow cylindrical shape in the above embodiment.

It is sufficient that the pressure of the compressed air introduced into the pneumatic cylinder is set so as to conform to the rigidity when the log is turned to a diameter close to the minimum diameter. Even if it is continuously introduced, there is no danger that the log will be bent toward the veneer for single veneer cutting, and there is an advantage that the structure of the introduction path can be simplified, but if necessary, a higher pressure can be used. When the setting is set to, when the cross section of most of the log is turned according to the spiral curve, the introduction is stopped every time by operating the solenoid on-off valve, etc. If, for example, a change in the required power of the outer peripheral drive mechanism (change from a state where the required power increases / decreases to a state where the required power is constant) at the time point is used as a signal source, the time point can be accurately determined. Can be determined, It is also extremely easy to perform decompression automatically.

The compressed air is introduced into the pneumatic cylinder through a pressure-reducing valve with relief, as shown in the above-mentioned embodiment, or is omitted from the drawing. It is desirable that the pressure (biasing force) be made as small as possible when the backup roll advances and retreats by taking measures such as introduction through the air cylinder. In order to cushion the collision, it is preferable to provide a suitable cushioning mechanism in the pneumatic cylinder, but at least on the side where the backup roll retreats, for example, a synthetic resin, hard rubber, etc. It is desirable to use a precise buffering mechanism with as small a buffering area as possible, such as a mechanism in which a very thin buffering member is interposed.

The stroke (movable length) of the pneumatic cylinder is, as a rough guide, a length adapted to the irregularities on the outer periphery of a generally used log, but is always adjusted to all irregularities of various logs. It is not necessary, and even if the backup roll does not come into contact with some of the recesses, there is no danger that it will cause any particular problem in practical use. There is no problem with narrowing the selection, but in any case, if a configuration is adopted in which compressed air is continuously introduced until the end of turning, even if the core is damaged, the backup roll is In order not to collide with the cutting blade, it is necessary to restrict the stroke to a length less than the core diameter of the raw wood.

It is sufficient that the pneumatic cylinder follows the stepping movement of the plane table only in the forward movement, and in the backward movement, the plane table returns in the direction of the center of the log (usually returns earlier than the stepping movement).
Irrespective of this, you can move it back in the direction of the core of the log at any speed, and you can safely return, at the same time as the return of the plane table,
There is no particular problem whether it is before or after the return of the plane table.However, in the case of adopting a configuration in which the compressed air is continuously introduced until the end of the turning, the spindle is not used because of the dropping property of the core. Before releasing the gripping of the core, it is preferable that the backup roll is moved back to a position away from the core, and if a stepless variable speed type moving mechanism as exemplified in the above-described embodiment is provided, these It is convenient because the timing and speed can be set arbitrarily.

For example, when turning a log having an abnormally protruding convex portion such as a nodule or a branch, or when gripping and turning the log in an eccentric manner in consideration of the internal cavity, etc. Since the backup function in the initial stage of turning is almost useless, it is not always necessary to actuate the backup roll from the start of turning according to the principle described above, but it is sufficient if the backup roll is actuated at an appropriate time during turning. For exceptional usage, it is convenient to have a continuously variable speed type moving mechanism that can move the pneumatic cylinder forward faster than the plane table's stepping feed only when necessary. In any case, the type of the veneer race itself is not limited to the outer peripheral drive type as exemplified in the above-described embodiment. For example, instead of the above outer peripheral drive roll, a disk-shaped rotating member may be appropriately arranged in the axial direction. Rotary rotor attached at every interval A spindle drive type with a rotating roll that supplies power required for veneer cutting mainly from the spindle, or the power required for veneer cutting is supplied exclusively from the spindle without any rolls. It can be applied to other types of veneer races, such as a conventional spindle drive type.

[0031]

As is clear from the above, according to the pressing method according to the present invention, the log can be more reliably and stably backed up as compared with any of the known methods. The effect of the present invention on the optimization and rationalization of the plate cutting process is extremely large.

[Brief description of the drawings]

FIG. 1 is an explanatory side view of a veneer race used for carrying out the present invention.

FIG. 2 is an explanatory diagram of an operation of a backup roll.

FIG. 3 is a diagram illustrating the operation of a backup roll.

FIG. 4 is a diagram illustrating the operation of a backup roll.

[Explanation of symbols]

 1: Plane table 1a: Single-plate cutting blade 2: Pressure bar table 3: Peripheral drive mechanism 4: Step feed mechanism 5: Backup roll 6: Pneumatic cylinder 8: Moving mechanism 9: Log rotation mechanism 10: Spindle 11: Log 12 ： Single plate 13 ： Control device

Claims (1)

(57) [Claims] 1. A pneumatic cylinder provided so as to move forward in the centering direction of a log following a step feed of a plane table when required.
While holding the backup roll so that it can move forward and backward, when the backup roll comes into contact with the outer peripheral surface of the raw wood turned by the veneer, the pneumatic cylinder and the pneumatic cylinder to retract to the stroke limit of the pneumatic cylinder Set the relative position to the plane table, and until the cross section of at least most of the log is turned according to the spiral curve, the backup roll can smoothly advance and retreat along the irregularities on the outer circumference of the log. A method for pressing a backup roll in a veneer race, wherein compressed air of a pressure is introduced into a pneumatic cylinder.