JPS6345281B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION When rotary cutting raw wood with a veneer lace, the present invention provides the shape of a chuck that acts as a pressing grip against the end surfaces of both ends of the raw wood, the pressing force applied to this chuck, and the rotational force applied to the chuck. This is related to the fluid pressure control of the spindle that applies the force, and its purpose is to maintain a stable grip on the log depending on the type of log to be rotary cut, i.e., the hardness or softness of the log. The objective is to reliably transmit the rotational force of the spindle to the

In general, when chucking logs in veneer lace, the ends of both ends of the log have traditionally been pressed and gripped by chucks. It is also provided with a plurality of wedge-shaped claws 3 arranged at appropriate intervals in a radial manner centered on the central protrusion 2, and the central protrusion of chuck 1 2 was used as a reference for the log core, and the log was clamped and held from both ends of the wood by the forward movement of a spindle operated by fluid pressure.

Normally, the logs supplied to veneer lace have a weight of around 2 tons, although this varies depending on the diameter and length of the logs. A gripping force is required to support the blade and resist the cutting resistance generated by the blade during rotational cutting.

For this reason, a huge clamping force is required to press and grip the wood at both ends of the wood.However, as a conventional method, a fluid of approximately 70 to 80 kg/cm ² is applied to the spindle. Apply pressure and
Place the chuck 1 shown in the figure facing the end surface of the log at both ends, tighten it with high pressure, then reduce the fluid pressure applied to the spindle to a low pressure of around 50 kg/ ^cm2 , and rotate the spindle while constantly applying this low pressure tightening. It was rotary cutting logs.

However, according to this conventional method, despite the differences in the species of logs to be rotary cut,
Since the fluid pressure in the stages is used to switch and tighten the end faces of the raw wood, due to the difference in hardness and softness of the materials,
Accurate gripping by chuck 1 cannot be expected.

In other words, when dealing with hard logs, the chuck 1 only presses and grips the log with the tips of its wedge-shaped claws 3 slightly biting into the end faces of both ends of the log, and the log is not fully supported. As a result, cutting may become impossible, and even if rotary cutting is attempted, it will result in so-called "idling", and the spindle rotation will not be accurately transmitted to the log, resulting in damage to the cutter.

In addition, for soft logs, the above-mentioned constant fluid pressure becomes an excessive load that cannot be absorbed by the ends of the fragile logs, and not only the 3 claws of chuck 1 but also the chuck 1 itself is completely buried. Therefore, the log is merely supported and rotary cutting is not possible.

In recent years, with the deterioration of the raw wood situation, such bipolar phenomenon of hardness and softness of materials has increased, and the above-mentioned tendency is further exacerbated.

Furthermore, when it comes to stably gripping raw wood whose diameter becomes smaller as it is rotary cut, there remains a problem that cannot be fundamentally solved by the conventional method. This is basically in the shape of a chuck 1, and the end surfaces of both ends of the raw wood are received at an arbitrary position 4 on the wedge surface of the claw 3, as shown in FIG.
Once the grip is completed, the rotation of the spindle is transmitted to the log.

That is, in order to grip the end faces of both ends of the raw wood and transmit the spindle rotation, the claws 3 of the chuck 1 are wedge-shaped, and the chuck 1, which is constantly applied with low pressure clamping force during rotary cutting, is designed to hold the small diameter of the raw wood. With this process, the wedge surfaces of the claws 3 have the opposite effect and gradually dig into the log, causing tip cracks 5, making it impossible to obtain the desired veneer veneer, and resulting in the log breaking.

In view of the above description, the present invention completely eliminates the idea fundamentally inherent in the conventional method, that is, the gripping at any position 4 on the wedge surface of the claw 3 when pressing and gripping the end surfaces of both ends of the raw wood. This system provides a chuck that has been wiped cleanly and stably presses and grips the log, while accurately controlling the fluid pressure applied to this chuck via the spindle to reliably transmit spindle rotation to the log. An embodiment of the invention will be described based on the accompanying drawings.

The chucks that press and hold the end faces 11 of the raw wood 10 usually consist of a small chuck 12 on the inside and a large chuck 13 for storing the small chuck 12 on the outside. is attached to the tip of a small spindle 14 which is movable forward and backward by fluid pressure control, and the large chuck 13 is similarly attached to the tip of a large tubular spindle 15 which is movable forward and backward by fluid pressure control. , the small spindle 14 is slidably fitted into the large spindle 15.

Central part 1 located on the front side of the small chuck 12
6 is usually made hollow over a certain depth, and is a part on which a central protrusion 17 serving as a reference for the core displayed on the end faces 11 of both ends of the raw wood 10 is removably attached.

A plurality of pawls 20 are protrudingly arranged at arbitrary intervals on the annular portion 18 located on the front side of the small chuck 12 excluding the central portion 16, and on the front annular portion 19 of the large chuck 13. The space 21 between the bases 20 is formed flat so that they are on the same plane.

This claw 20, as shown in FIGS. 3 and 4,
They are wedge-shaped and are arranged approximately radially from the center of the front surface of the small chuck 12 at equal intervals, and the tip of each claw 20 is parallel to the flat surface or slightly inclined inward. It is formed as follows.

A contact type detector 22 such as a limit switch is mounted on one side wall of the hollow central portion 16, with its tip portion being flush with the flat surface of the annular portions 18 and 19.
Or, it is installed so that it extends slightly inward from the flat surface. This detector 22 is for controlling the fluid pressure applied to the large and small spindles 14 and 15, which will be described later, and issues a detection command when its tip portion 22a comes into close contact with the end faces 11 of both ends of the log 10. It is.

However, the raw wood 10 to be supplied to the veneer lace has both end surfaces 11 connected to the small spindle 1.
In some cases, the cut is not perpendicular to the axis connecting the centers of
is tilted in either direction with respect to the axis, and the annular portions 1 of the large and small chucks 12 and 13
8, 19 flat surfaces and both end surfaces 11 of log 10
It becomes impossible to accurately detect close contact with the object. Therefore, a plurality of detectors 22 similar to those described above may be implanted at arbitrary positions within the interval 21 between the annular portions 18 and 19.

Next, assuming that the fluid pressure applied to the large and small spindles 14 and 15 is hydraulic pressure, this hydraulic control will be explained based on the hydraulic circuit shown in FIG.

The rear end of the small spindle 14 is a small piston portion 23
The small piston part 23 is slidably inserted into the small cylinder chamber 24, and the inner peripheral part of the large spindle 15 is tightly fitted with the small spindle 14, and the rear end is connected to the large piston part 25. The large piston portion 25 is slidably fitted into the large cylinder chamber 26. These large and small cylinder chambers 2
Ports 27, 28, 29, 30 for supplying and discharging pressure oil are bored in the front and rear ends of the pipes 4, 26, respectively, and piping 31, 32, 33 is connected to each port 27, 28, 29, 30, respectively. , 34 are connected.

Each piping 31, 32 of the small cylinder chamber 24 and each piping 33, 34 of the large cylinder chamber 26 are connected to a switching valve 3 of the same structure that regulates the flow rate of pressure oil in three ways.
5 and 35', respectively. The first of these
The embodiment is a pressure oil supply mechanism 37, 37' for advancing the large and small spindles 14, 15 operated by the first switching valve 36, 36', and the second embodiment is a pressure oil supply mechanism 37, 37' for advancing the large and small spindles 14, 15 operated by the first switching valve 36, 36'. A third aspect is a fixed control mechanism 40, 40' that locks the pressure oil at a predetermined pressure.

These switching valves 35, 35' have pipes 41, 41',
42, 42' are connected, and one pipe 41,
41' communicates with the oil tank 43, and the other pipes 42, 42' once join the pipe 44 and have a check valve 45, and from the oil tank 43 via a pump 47 driven by a motor 46, It pumps oil.

A pressure gauge 49 is installed in a pipe 48 branched from and connected to this pipe 44, and when oil is pumped up from the oil tank 43 at a discharge allowable pressure set to the pressure gauge 49 or higher, the oil tank 43
A safety valve 50 is installed to drain excess oil from the navel.

Next, the basic principle of the present invention will be explained.

First, the maximum fluid pressure applied to the large and small spindles 14 and 15, that is, the maximum pressing force applied to the large and small chucks 12 and 13 that grip the ends 11 of the log 10, are as follows:
For convenience, the pressure is set at 100 kg/cm ² and this maximum pressure value is set on the pressure gauge 49.

In addition, the piston parts 23 and 25 of the large and small spindles 14 and 15 are made to stand by at the retraction limit in each cylinder chamber 24 and 26, and the raw wood 10 is supplied and placed at a predetermined position on the veneer race, and the first switching valve 36 , 36', the switching valves 35, 35' are connected to the pressure oil supply mechanism 37, 36'.
Make it 37'.

Next, pressure oil is supplied from the oil tank 43 to the rear chambers of the large and small cylinder chambers 24 and 26 through the respective rear ports 28 and 30, and oil in the front chambers of the large and small cylinder chambers 24 and 26 is supplied. , through the respective front ports 27, 29 to the oil tank 43 and advance the large and small spindles 14, 15.

When the claws 20 of the large and small chucks 12 and 13 attached to the tips of the large and small spindles 14 and 15 come into contact with the butt surface 11, the oil pressure gradually increases, allowing the large and small spindles 14 and 15 to continue moving forward. At the same time, biting is completed. At this time, large and small chucks 12, 13
When the flat space 21 of the annular portions 18 and 19 comes into close contact with the butt end surface 11, the tip portion 22a of the detector 22 detects this, and the first switching valve 3
6, 36' operate in reverse, and the switching valves 35, 35' become fixed control mechanisms 40, 40'.

Therefore, the pressure required to bring the flat surfaces of the large and small chucks 12 and 13 into close contact with the butt end surface 11 is, for example, 60
Kg/ ^cm2 , large and small spindles 14,1
This pressure of 60Kg/cm ² applied to 5 will be fixed and maintained at all times.

Thereafter, the large and small spindles 14 and 15 are rotated via a rotating member such as a chain wheel, and the log 10 that receives this rotation is cut. To the base, end side 1
1, there is no gripping deviation during rotary cutting, and furthermore, the flat space 21 of each annular portion 18, 19 and the end surface 11 have a constant area. The grip remains in close contact for a long time, and frictional resistance occurs due to the fixed control pressure load, resulting in a stable gripping state that resists cutting resistance.
The rotational force of the large and small spindles 14 and 15 can be reliably transmitted to the log 10.

During rotary cutting, when the diameter of the log 10 becomes small to a certain extent, the large chuck 13 is moved to the large spindle 15 by the operation of one of the second switching valves 38', and the switching valve 35' becomes a pressure oil discharge mechanism 39'. is moved back to the retraction limit, so the grip on the end face 11 is released, and the log 10 is then held solely by the small chuck 12 and rotary cut.

When the rotary cutting of the log 10 is completed, the second switching valve 38 is activated, and the switching valve 35 is connected to the pressure oil discharge mechanism 39.
and the pressure oil is controlled in the opposite direction to the path described above. For this reason, a small chuck 12 is formed on the butt end surface 11.
is released, the small spindle 14 reaches its retraction limit, and waits for the next operation.

As described above, according to the present invention, when chucking the raw wood to be supplied to the veneer lace, the annular portion located on the front side of the chuck is divided into a claw portion that completely bites into the end surface of the raw wood, and a mutual contact between the bases of these claws. The area within the gap is divided into flat parts that are formed on the same surface, and the fluid pressure applied to the spindle is controlled by a detector installed in the front of the chuck, so it can handle differences in each type of log. This makes it possible to accurately control the minimum fluid pressure required to grip the butt end surface, and during rotary cutting of the log, frictional resistance is generated between the flat part of the annular part and the butt end surface, which are in close contact with each other. As a result, the raw wood is held in a stable state that resists cutting resistance, and at the same time, the rotational force of the spindle can be accurately received, making it possible to obtain good veneer veneers with uniform thickness even down to small diameters.

[Brief explanation of the drawing]

Fig. 1 is a front view showing a conventional chuck, Fig. 2 is a side view of the same, Fig. 3 is a front view showing an embodiment of the chuck of the present invention, Fig. 4 is a side view of the same, and Fig. 5 is a main view of the chuck. FIG. 2 is a hydraulic circuit diagram showing an example of fluid pressure control according to the invention method. 10... Log, 11... Wood end, 12... Small chuck, 13... Large chuck, 14... Small spindle, 1
5... Large spindle, 18, 19... Annular part, 20...
Claw, 21...within interval, 22...detector, 37, 37'
...Pressure oil supply mechanism, 39, 39'...Pressure oil discharge mechanism,
40, 40'...Fixed control mechanism.

Claims (1)

[Scope of Claims] 1. A pair of spindles arranged so as to be able to move back and forth are advanced by fluid pressure against the end surfaces of both ends of raw wood supplied to the veneer lace, and a chuck attached to the tip of the spindle is pressed. , a plurality of claws protruding from the front surface of the chuck at arbitrary intervals are completely bitten into the end faces of both ends of the log, and the flat parts located within the distance between the bases of each claw are attached to the ends of both ends of the log. A method for chucking logs in veneer lace, characterized by fixing and maintaining control of the fluid pressure applied to the spindle when it comes into close contact with a surface. 2. In a chuck that presses and grips the end faces of raw wood through a spindle, a plurality of claws are protruded from an annular portion located on the front side of the chuck at arbitrary intervals, and the base of each claw is A veneer lace characterized in that the space between the chucks is flat, and a detector is installed on the front surface of the chuck so that its tip is located at the same level as the flat part or slightly inward from the flat part. A check of logs in.