JPH043284B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a log support shaft for veneer lace that is press-fitted into a central hole drilled in the core of a log to support the log.

Conventionally, regarding this type of support shaft, there have been published articles such as "Method for stripping off veneer or similar materials and tools for carrying out the method" (Japanese Patent Publication No. 10960/1973) or "Rotary wood cutting device" (Utility Model Publication No. 1983). −21506
There is already a technology disclosed in Japanese Patent Publication No. 2003-121013, etc., and the former is characterized by having a plurality of plate-shaped flanges whose leading ends in the press-fitting direction are chamfered diagonally as entrainment equipment on the outer circumferential surface of the shaft body. The log is supported by uniformly press-fitting each flange around a center hole previously drilled in the log by obtaining a centripetal action of the leading end of each flange in the press-fitting direction. ,
The latter is characterized by having a large number of claws that can move in and out of the outer peripheral surface of the shaft body, and after inserting into a center hole previously drilled in the log, the large number of claws are made to protrude outward. It supports the
By supplying driving force from inside the log via these support shafts, it is possible to eliminate the disadvantages caused by the conventional supply of driving force from the end face of the log, and to turn the log to a smaller diameter.

However, in the former case, due to the press-fitting action of each flange, and in the latter case, due to the protruding action of each claw, compressive stress directed from the inside to the outside always remains in the log, so as it turns, When the diameter of the log is reduced below a certain limit, the log tends to be destroyed due to the compressive stress, especially when various cracks due to growth stress etc. already exist in a part of the log. Since the cracks are enlarged by the compressive stress and the raw wood is destroyed, there is a problem in that the purpose of turning the raw wood to a smaller diameter cannot be achieved as desired.

The present invention was developed in order to eliminate the drawbacks of the known log support shafts, and it supports the log more stably by press-fitting it into a central hole drilled in the core of the log. The aim is to improve the turning yield of logs by turning the shaft to a smaller diameter, and specifically, by forming protrusions at appropriate positions on the outer circumferential surface of the shaft body, , a characteristic configuration is adopted in which a cutting blade for cutting and forming at least a part of the press-fitting path of the protruding body is provided at the leading end of the protruding body in the press-fitting direction.

According to the above configuration, at least a part of the press-fitting path of the protruding body is cut into the raw wood in advance by the cutting action of the cutting blade provided at the leading end in the press-fitting direction of the protruding body, prior to press-fitting the protruding body main body. The remaining compressive stress from the inside to the outside of the log due to the press-fitting of the support shaft is greatly reduced, so the breakage of the log due to the compressive stress is also prevented. This is extremely effective because it is possible to turn the log to a smaller diameter than with the known log support shaft, and improve the yield of log turning.

Hereinafter, the present invention will be described in more detail with reference to an example of implementation illustrated in the drawings.

First, the center hole into which the log support shaft according to the present invention is press-fitted is bored in the core of the log 1, as is clear from FIG. 1, for example, but the form of the center hole 2 will be detailed later. As described above, as is clear from FIG. 2, the log support shaft 3 according to the present invention is
It is press-fitted into the central hole 2 drilled in the log 1 as shown in the figure, and used to turn the log 1 with a veneer lace cutter 5.

3 to 10 illustrate typical examples showing the engagement relationship between the log support shaft and the center hole, but as is clear from the drawings, the center hole drilled in the log 1 2, as illustrated in FIGS. 3 to 6,
In addition to the form in which the hole is drilled through the core of the log 1, there is also the form in which the hole is not penetrated, in which the hole is drilled to an appropriate depth from both or one end of the log 1, as illustrated in FIGS. 7 to 10. There is no problem with either form as long as it is selected according to various conditions.

The form of the log support shaft to be press-fitted into the center hole is, for example, as shown in FIG. Later, the form of the log support shaft 3a that is held and used by a chuck 6 of an appropriate mechanism provided on the veneer lace, and the form of the log support shaft 3a used, for example, as illustrated in FIGS. , which is integrated with a veneer lace and can be moved in and out by pressing means such as hydraulic pressure, from the end of one side of the log 1, as illustrated in FIGS. 4 and 10, or from the end of one side of the log 1, or
As illustrated in the figure, from both ends of the log 1 to the center hole 2
For example, the log support shaft 3b may be used by being press-fitted into the log support shaft 3b, but any format may be used.

Of course, if necessary, a structure in which the log support shafts on both sides are engaged with each other in the center hole as in the example shown in FIG. 6, or a conventionally known structure as in the examples in FIGS. Similar to the spindle in veneer lace,
A configuration in which a claw for supplying driving force is attached to the tip part, or as in the example shown in FIG. 9, a large spindle 7 that can supply driving force until an appropriate time is fitted to the outer side, similar to the known double spindle mechanism. configuration, and even the first
As in the example shown in Figure 0, there is no problem in adopting a configuration in which either side is equipped with a conventionally known spindle 8 and used in conjunction with it, and a general effect based on each configuration can be expected, and other than the example shown in the figure. In addition, it is also possible to adopt a configuration in which the configurations of the illustrated examples are mutually replaced or combined, and furthermore, although not shown, all conventionally known types of peripheral drive systems, center drive systems, and combination systems of these systems are possible. However, in any case, the details of the characteristic aspects of the log support shaft according to the present invention are as described below.

The log support shaft according to the present invention is made of stainless steel, general steel plated if necessary, or other materials with high rigidity, as shown in FIGS. 11 and 12, for example. The first
As shown in Fig. 3, it is used by press-fitting into the center hole 2 drilled in the shaft core of the log 1 as shown in Fig. 14, and as is clear from the figure, the outer peripheral surface of the log support shaft 3 is placed at an appropriate position. By forming the protruding body 4 on the top, the engagement between the raw wood support shaft 3 and the raw wood 1 is made extremely accurate. The greatest feature is that a cutting blade is provided to cut and form at least a part of the press-fitting path of the projecting body 4. Based on this configuration, the press-fitting of the log support shaft 3 into the center hole 2 is facilitated, and Log 1
This makes it possible to significantly reduce the stress that induces fracture.

That is, as in the support shaft disclosed in the above-mentioned Japanese Patent Publication No. 41-10960, a cutting edge is not provided at the leading end in the press-fitting direction of the plurality of plate-shaped flanges provided on the outer circumferential surface of the shaft body, but only at an angle. When chamfering, a centripetal action can be expected with respect to the center hole of the chamfered part, but on the other hand, a strong pressing force is required for press-fitting, which not only makes press-fitting difficult, but also requires forcible intervention of the flange. , the compressive stress from the inside to the outside increases, inevitably causing tip cracking, at least a portion of which ultimately remains in the log, resulting in the disadvantage that the breaking strength of the log is significantly reduced, At the same time, since the press-fitting direction of the log support shaft and the fiber direction of the log do not necessarily match, with the forcible intervention of the flange, some of the wood fibers are ripped out and intervened between the log support shaft and the log. There is also the disadvantage of promoting splitting of the log, so that overall the engagement between the log support shaft and the log is extremely inaccurate, resulting in a tendency for the log to break before being turned to a small diameter. On the other hand, as a similar technology to the present invention, there is a "log support shaft for veneer lace" (Japanese Patent Publication No. 2-54201) filed by the present applicant, but the log support shaft of the similar technology has a protruding shape. Since a cutting blade is provided at the tip of the body in the insertion direction to cut and form at least a part of the insertion path of the protruding body, if chips are not removed smoothly, splitting of the log will be facilitated. It has a structural defect, and if the raw wood has hard knots, it also has a structural defect that makes it extremely difficult to form an insertion path at the knot.

However, since the log support shaft according to the present invention adopts the above-mentioned configuration, when the log support shaft is press-fitted, the cutting blade cuts the wood fibers along the press-fitting direction.
Since it forms at least a part of the press-fitting path of the protruding body, the subsequent press-fitting of the protruding body is significantly facilitated, and tip cracking is less likely to occur, and even if it occurs, it tends to be guided in the press-fitting direction. In the end, very little remains on the raw wood, eliminating the risk of a decrease in the breaking strength of the raw wood due to tip splitting.Furthermore, there is almost no plucking of wood fibers, and no chips are generated, so the raw wood is free from residual wood fibers and chips. Furthermore, even if there are hard knots in the raw wood, it is sufficient to simply cut them, so it is easier to form the insertion path than when cutting as in the similar technology described above. In general, the engagement of the log support shaft with the log becomes extremely accurate and stable.

In addition, such accurate and stable engagement between the log support shaft and the log simply imparts rigidity to the log, significantly reducing the bending of the log due to the reduction in diameter, making turning easier and more stable. Not only does it have the effect of
It is also effective because it facilitates the supply of driving force from the log support shaft, thereby enabling the turning of logs to a smaller diameter than in the past, and greatly improves the yield of turning logs. You can expect it.

Incidentally, according to experiments, a center hole with a diameter of 40 mm was drilled through a radiata pine with an outer diameter of about 250 mm, and in the same way as in the examples shown in FIGS. 11 and 12,
A raw wood support shaft having an outer diameter of 42 mm and having a substantially isosceles triangular cross section and 20 protrusions extending continuously in the same direction as the axis formed on the outer peripheral surface is press-fitted into the center hole,
All of the driving force required for turning was supplied from the log support shaft, and turning could be performed until the outer diameter of the stripped core reached 47 mm.

Of course, the raw wood support shaft according to the present invention has an extremely simple shape with only a protrusion formed on the outer circumferential surface as described above, and if necessary, the thickness of the shaft body can be adjusted to be equal to the thickness of the center hole. In addition to being able to provide rigidity and adaptability to abnormal situations and abnormal loads such as log destruction, it has excellent practicality and can be used repeatedly.

Next, to describe the more detailed aspect of the log support shaft, first, the form of the protrusion will be explained in the first section.
In addition to the form that extends continuously in the same direction as the axial direction of the log support shaft as shown in FIGS. 1 and 12, the axial center of the log support shaft as shown in FIGS. A form in which it extends continuously with an inclination to the direction, or a form in which it extends intermittently in the same direction as the axial direction of the log support shaft, as shown in the examples of FIGS. 27 and 28, or Although not shown in the drawings, the main purpose is to have a shape that extends intermittently with an inclination to the axial direction of the log support shaft, and to suppress damage to the end of the log as much as possible during the turning process. In addition, there are forms in which the formation of the part corresponding to the end of the log is omitted, etc.
Various shapes are listed, and in addition to the approximately isosceles triangular cross-sectional shape as shown in FIGS. 11 and 12, the most typical examples are shown in FIGS. 15 to 19. As described above, various shapes may be used, but in any case, from the viewpoint of ease of press-fitting and stability of power transmission, the shape should protrude from the shaft body (base) as much as possible without impairing rigidity and be cut. It is preferable to arrange them in rows, especially in an even radial pattern as shown in each example, as the shape has a small area, and the appropriate number of rows is 3 or more and 30 or less. Experimentally, it was effective to set the thickness to 1 mm or more and 2.5 times or less the thickness of the veneer veneer to be cut.

On the other hand, from the viewpoint of preventing tip cracking and uniformity of wood fiber division during press-fitting, the shape of the cutting edge provided on the protruding body should be such that the cutting edge is oriented toward the press-fitting direction, as shown in the example shown in Fig. 20. It is preferable to have a double-edged shape with a right angle or an inclination close to a right angle, and have a hook surface on both sides. Even if it is a single-edged form with a cutting surface provided only on one side, as in the example shown in Fig. 22, it is practical as long as at least a part of the press-fitting path of the protruding body can be cut and formed. There is no particular problem.

In addition, from the viewpoint of rigidity, it is preferable for the shape of the shaft body (base) that forms the protrusion to have as large a diameter as possible within a range that is compatible with the center hole; Although it is effective to make the diameter small, it is desirable to drill the center hole straight during press-fitting.

In addition, in the examples shown in FIGS. 23 and 24, the starting end portion of the shaft body in the press-fitting direction is formed into a tapered shape, and the protruding body 4 is formed in a portion other than the tapered starting end portion 9. If configured as shown in FIG. Similarly, the same effect can be expected even if the protrusion 4 is formed in a tapered shape at the tapered starting end portion 9.

In addition, the examples shown in FIGS. 25 and 26 have a cutting edge also formed at the starting end of the shaft body in the press-fitting direction, and a chip pocket 10 for storing chips is provided in the center. This makes it practical to press fit the center hole drilled into the raw wood while slightly correcting the distortion or deviation.

In addition, regardless of which of the above configurations is adopted, the leading end of the log support shaft in the press-fitting direction (especially the cutting edge portion of the projecting body)
Since this part is subject to more wear and damage than other parts, the part from the appropriate position of the log support shaft to the leading end in the press-fitting direction, such as the position 11 in Fig. 27, should be separated and removed. It would be convenient if it could be freely provided and replaced at any time, and of course, as in the example shown in Fig. 18, the protruding body should be constructed separately from the shaft body so that only the protruding body could be replaced at any time. It is also practical.

In addition to the above-mentioned known mechanisms, the log support shaft according to the present invention can be used in combination with various mechanisms and devices for conventionally known veneer laces, such as a back-up roll for preventing log warping. However, in any case, if necessary, a known mechanical/electrical tuning mechanism may be interposed between the drive mechanism of the log support shaft and the drive mechanism of other members, and the It is possible to selectively determine the proportion of driving force to be supplied from the log support shaft as desired, and it is possible to set a fixed or The driving force may be supplied variably from the log support shaft, but considering the stability and accuracy of the driving force supply based on each mechanism, in the early stage of cutting when the log diameter is relatively large, other drives may be used. It is effective to switch stepwise or sequentially mainly to the power supply from the log support shaft, and mainly to the power supply from the log support shaft at the final stage of cutting when the diameter of the log becomes small.

In addition, when all the driving force required for turning is supplied from the log support shaft, it is recommended to press fit the log support shaft into the center hole of the log with a length equivalent to 1/3 or more of the total length of the log. In this case, the depth of the center hole of the log and the length of the log support shaft (if two, the total length) should be adjusted so that the protruding body can engage with the log over a length that reaches at least 1/3 of the total length of the log. It was effective to set the

As is clear from the above, the support shaft according to the present invention is extremely effective because it is possible to turn logs to a smaller diameter compared to known log support shafts, and it is possible to improve the log turning yield. Therefore, the effect of implementing the present invention on resource utilization is significant.

[Brief explanation of drawings]

The drawings are for explaining the present invention, and Fig. 1 is a cross-sectional view of a log with a center hole drilled, and Fig. 2 is a perspective view for explaining the state of turning the log into which the log support shaft has been press-fitted. Explanatory drawings, FIGS. 3 to 10 are schematic cross-sectional explanatory views for explaining the engagement state between the log support shaft and the center hole of the log according to the present invention, and FIGS. 11 and 2
3, FIG. 25, and FIG. 27 are partial front views of the log support shaft according to the present invention, FIG. 12 is a side view of FIG. 11, and FIG. 13 is a side view of the log with a center hole drilled.
Fig. 14 is a side explanatory view for explaining the state of turning a log into which a log support shaft is press-fitted, and Figures 15 to 19 are portions of the log support shaft for explaining other embodiments of the protrusion. 20 to 22 are partially enlarged perspective views of the log support shaft for explaining the form of the cutting blade, FIG. 24 is a side view of FIG. 23, and FIG. 26 is a side view of FIG. 25. , FIG. 28 is a side view of FIG. 27. 1... Log, 2... Center hole, 3, 3a, 3b...
...Log support shaft, 4...Protrusion, 6...Chick,
7...Large spindle.

Claims (1)

[Claims] 1. A raw wood support shaft for veneer lace that is press-fitted into a central hole drilled in the shaft core of a raw log to support the raw wood, which has a protruding body formed on its outer circumferential surface and a leading direction in the press-fitting direction of the protruded body. A raw wood support shaft for a veneer lace, characterized in that a cutting blade is provided at an end portion to cut and form at least a part of the press-fitting path of the projecting body.