JPS6263008A - Band saw machine - Google Patents

Abstract

PURPOSE:To aim at the elimination of a 'surface-slip' phenomenon in a saw blade, by feeding and discharging pressure oil to or from a hydraulic cylinder repetively at the time of its infeed motion, and giving retraction and return motions to the band saw blade, in case of a band saw machine cutting a large- sized hard cuttable work. CONSTITUTION:At the time of cutting a large-sized hard cuttable work, in that state that a band saw blade 1 is bent upward due to cutting resistance, all teeth comes uniformly into contact with a work W, a solenoid Q1 is excited and pressure oil is little fed to a hydraulic cylinder 3. Afterward, another solenoid Q2 is excited and it is discharged at a proper flow velocity whereby the band saw blade 1 is floated, cutting the central part, and the band saw blade 1 is restored, thus cutting for both ends is performed. If infeeding operation takes place while repeating this motion periodically, all teeth by no means uniformly comes into contact with the work W. With this constitution, such a 'surface-slip' phenomenon in the saw blade is prevented from occurring so that highly efficient cutting is realizable.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to a band saw for cutting steel materials and the like.

<Prior Art> In a band saw machine for cutting steel materials, such as a horizontal band saw machine, a pair of saw wheels on which band saw blades are rotated are supported on a saw frame that can be raised and lowered, and the cutting into the work material is generally controlled by This is done by adjusting the amount of oil discharged from a hydraulic cylinder that supports the saw frame using a flow control valve or the like, and the saw frame is moved apart or raised by supplying pressure oil to the hydraulic cylinder using a hydraulic pump. During cutting, only the cutting operation is performed, and the saw frame is not separated during cutting unless an abnormality occurs.

<Problems to be Solved by the Invention> When cutting, for example, a large, difficult-to-cut material using the conventional bandsaw machine as described above, all blades come into equal contact with the workpiece, as shown in Figure 2 (a). Therefore, there was a problem in that the saw blade "top-slide" phenomenon occurred, and the cutting speed was significantly reduced due to work hardening of the work material.

In addition, in large band saw machines, there are two parts that guide the saw frame.
In addition to the large frictional resistance between the book guide post and the metal, the hydraulic cylinder and piston that supports the saw frame, and the cutting edge, the cutting speed of the saw frame is very slow, resulting in the stick-slip phenomenon The process tends to be unstable, which is a negative factor in cutting efficiency and saw blade life.

<Means for solving the problems> The present invention solves the above problems all at once. The configuration will be explained with reference to FIG. 1, which is an embodiment drawing.

A saw frame 2 on which a rotating band saw blade 1 is suspended is supported by a hydraulic cylinder 3, and a hydraulic circuit Hc that regulates the supply and discharge of pressure oil is connected to the hydraulic cylinder 3. In a device that controls separation and cutting into the hydraulic cylinder 3, pressure oil is repeatedly supplied to the hydraulic cylinder 3 during the above-mentioned cutting operation.
By discharging the cutting material, the band saw blade 1 is configured to cut into the workpiece W while giving the movement of separating and returning to the workpiece W.

When cutting large, difficult-to-cut materials, the band saw blade 1, which has been given a cutting depth by the hydraulic circuit Hc, is bent upward due to the cutting resistance as shown in Fig. 2 (a), and all the blades are When the saw frame 2 is in equal contact with the workpiece W, the saw frame 2 is supplied with a small amount of pressure oil to the hydraulic cylinder 3 and then discharged at an appropriate flow rate.
When the band saw blade 1 is lifted up a little and then lowered, the band saw blade 1 is raised to cut the central part A, as shown in FIG. Become. If this operation is repeated periodically while cutting, all the blades will not come into contact with the workpiece W equally. Therefore, highly efficient cutting can be achieved without causing the "top slip" phenomenon of the saw blade.

In addition, in a large bandsaw machine, by activating the pressure oil supply/discharge means P during the cutting process and periodically raising and lowering the saw frame 2 by a small amount while cutting, the stick-slip phenomenon described above is eliminated and the stability is improved. A sharp cut can be obtained.

<Example> Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention. The band saw blade 1 is rotated by a pair of saw wheels 4.4' supported on a saw frame 2, and is driven to travel. The saw frame 2 is slidably supported by main and sub-columns 6.7 provided upright on a base 5, and is supported by a hydraulic cylinder 3. Vices 8 and 8' are arranged on the base 5, and hold the workpiece W therebetween.

The hydraulic cylinder 3 is connected to a variable displacement pump 1) through an oil passage 10 communicating with its port. Directional control valves 12 and 1
3. Resistance valve 14. A known lifting control hydraulic circuit Hc consisting of a flow rate control valve 15 is connected, and the saw frame 2 is raised by setting the direction control valve 13 to neutral and energizing the solenoid Q1 of the direction control valve 12 to activate the hydraulic cylinder 3. This is done by supplying pressure oil. With the solenoid Q1 de-energized, the solenoid Q2 of the directional control valve 13 is energized,
The saw frame 2 is lowered by discharging the pressure oil in the hydraulic cylinder 3 directly into the tank, and the solenoid Q3 is energized to drain the pressure oil in the hydraulic cylinder 3 into the resistance valve 14. The cutting feed is obtained by discharging via the flow control valve 15.

A pressure oil supply/discharge circuit P separate from the above-mentioned hydraulic circuit Hc is connected to an oil passage 10 communicating with a port of the hydraulic cylinder 3. This pressure oil supply/discharge circuit P includes a volume cylinder 20 whose interior is partitioned into two chambers by a slidable piston 21, a directional control valve 22. and two flow control valves 23 and 24. One chamber of the volume cylinder 20 communicates with the oil passage 10, and the other chamber communicates with the directional control valve 22. The directional control valve 22 leads the aforementioned other chamber of the volume cylinder 20 to the outlet of the variable displacement pump 1) via the flow control valve 23 or opens into the tank via the flow control valve 24. be able to.

In the above configuration, when the solenoid Q3 is energized to give the band saw blade a cut into the workpiece W while the solenoids Ql and Q2 are not energized, when performing the above-mentioned separation/return operation, the energization of the solenoid Q3 is When the solenoid Q4 of the directional control valve 22 is energized at the same time as the release, pressure oil from the variable displacement pump 1) flows into the volume cylinder 20, displacing the piston 21 upward in the figure. As a result, the pressure oil in the volume cylinder 20 corresponding to the stroke of the piston 21 flows into the hydraulic cylinder 3 through the oil passage 10, raising the saw frame 2 by a predetermined amount. Next, when the solenoid Q4 is deenergized from this state, the pressure oil in the hydraulic cylinder 3 flows into the volumetric cylinder 20 due to the weight of the saw frame 2, and the piston 21 is returned to its original position. Therefore, the supply amount and discharge amount of pressure oil at this time are exactly the same. The speed of this supply and discharge is regulated by flow control valves 23,24.

Furthermore, although the stroke of the piston 21 is regulated by the stopper 25, it can also be adjusted by adjusting the excitation time of the directional control valve 22. Since the solenoid Q3 is excited at the same time as the solenoid Q4 is demagnetized, the cutting speed of the band saw blade 1 at this time follows the total flow rate of the flow rate control valves 15 and 24. As a result, during the return stroke of the piston 21,
Cutting corresponding to the flow rate of the flow rate control valve 15 will be performed.

When the above is applicable to cutting large workpieces, the hydraulic circuit Hc
When the pressure oil supply/discharge circuit P is operated repeatedly by energizing the solenoid Q4 of the directional control valve 22 at a predetermined period using a timer or the like during the cutting process, the workpiece W
On the other hand, the band saw blade 1 first moves away in the separation process as shown in Fig. 2(a).
It floats up from the upwardly bent state as shown in FIG. Next, in the return stroke, it descends together with the cutting depth of the hydraulic circuit Hc, and approaches the position shown in FIG. 2 fa) while cutting both ends A and 1. By repeating this operation at a constant cycle, the cutting edge of the band saw blade 1 does not come into contact with the workpiece equally over the entire length of the blade, but cuts while partially in contact with the work material, which allows the saw blade to "up". The phenomenon is avoided. This allows for high efficiency cutting and at the same time
By repeating the above-described operations, the stick-slip phenomenon caused by the frictional resistance of the sliding guide portion of the saw frame 2 and the hydraulic cylinder 3 is eliminated, and stable cutting is maintained.

In the above example, the solenoid Q4 of the flow control valve was repeatedly excited by a timer, but instead of the timer, a change in the cutting resistance value applied to the band saw blade 1 or a change in the oil pressure in the hydraulic cylinder 3 is detected and the signal is It is also possible to perform anti-ri excitation according to the following.

Incidentally, the pressure oil supply/discharge circuit P to the hydraulic cylinder 3 is not limited to the above-mentioned embodiment, and for example, as shown in FIG. It may be configured to be displaced by 32 or the like. At this time, the direction control valve 22. Flow control valve 2
3.24 is no longer necessary. In the above embodiment, a pressure oil supply/discharge circuit P is used in addition to the conventional hydraulic circuit Hc, but without this, the two directional control valves 12 of the hydraulic circuit Hc are used.
．． The same movement can be given to the saw frame 2 by alternately operating the 13 solenoids Ql and Q3. However, the upper and lower limits of movement will be inaccurate. In addition, in the above embodiments, the case where the present invention is applied to a two-post type horizontal bandsaw machine has been explained, but it is a matter of course that a hinge type horizontal bandsaw machine has a bandsaw blade suspended vertically and horizontally. Of course, it can also be used with vertical band saws that can make cuts, and even those whose saw frames are moved by screw feed.

Effect> As explained above, according to the present invention, in a bandsaw machine that cuts a workpiece by moving the saw frame that suspends the rotating bandsaw blade, the depth of cut can be reduced. By repeatedly moving the saw frame backwards during operation, the band saw blade repeatedly moves away from and returns to the workpiece while making cuts. Instead of being in equal contact with the material over the entire length of the blade, cutting is performed while substantially shortening the cutting length, resulting in highly efficient cutting without the "top slip" of the saw blade. In addition, the above-described repeating operation maintains stable cutting without the stick-slip phenomenon caused by the frictional resistance of the sliding guide portion of the saw frame 2 and the hydraulic cylinder 3.

Note that the present invention achieves the above-mentioned effects by simply adding pressure oil supply and discharge functions to the conventional hydraulic circuit Hc, so there is no difficulty in implementing it, and a conventional band saw machine can be easily modified. It is very popular.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an embodiment of the present invention, and FIG. 2 is an explanatory diagram of its operation. FIG. 3 is a diagram showing the main part of another embodiment of the present invention. 1-- Band saw blade, 2- Saw frame 3-
...Hydraulic cylinder, 6...-Main column 7-Subcolumn, 1)--Variable discharge amount pump 12, 13
．． 22--11 one-way control valve 14--Resistance valve

Claims (3)

[Claims] (1) In a band saw machine that cuts a workpiece material by moving a saw frame that suspends a rotating band saw blade, the saw frame is repeatedly moved during the cutting operation. 1. A band saw machine characterized in that the band saw blade cuts into a workpiece by repeatedly moving away from and returning to the workpiece by moving the band saw blade in the opposite direction. (2) The saw frame is supported by a hydraulic cylinder, and a hydraulic circuit for regulating the supply and discharge of hydraulic pressure is connected to the hydraulic cylinder to control the spacing and cutting of the band saw blade into the work material. In the band saw machine, a means for supplying and discharging pressure oil to the hydraulic cylinder is provided separately from the hydraulic circuit, and by repeatedly operating the supply and discharging means during the cutting operation, the band saw blade is able to contact the workpiece material. The band saw machine according to claim 1, characterized in that the band saw machine is configured to be able to cut while performing separation and return operations. (3) the supply/discharge means are partitioned by a slidable piston, and one chamber communicates with the hydraulic cylinder;
3. The bandsaw machine according to claim 2, wherein the other chamber is constituted by a volumetric cylinder that communicates with a hydraulic pump and an oil tank via a direction control valve and a flow rate control valve.