JPH01299302A - Control valve and cut controlling device of cutter utilizing the control valve - Google Patents

Abstract

PURPOSE:To automate flow adjustment by forming, on a sleeve, an orifice which is shaped in such a way to gradually increase flow as a spool advances and to drastically increase flow when the spool advances beyond a certain point. CONSTITUTION:A sleeve 15 is fit in a spool 9, and on the sleeve 15 an orifice 13 is formed, which is shaped in such a way to gradually increase flow as the spool 9 advances and to drastically increase flow when the spool 9 advances beyond a certain point. Since the formation automatically controls the extent of opening of the orifice 13, flow adjustment can be automatically performed.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention provides a control valve suitable for use in controlling the depth of cut of a cutting tool in a cutting machine, for example, and a control valve for a cutting machine using the control valve. This invention relates to a cutting control device.

(Conventional technology) Conventionally, various types of control valves are known.

The control valve is used in a hydraulic circuit for controlling the cutting depth of a band saw blade in a cutting machine such as a horizontal band saw machine.

In order to control the cut of the band saw blade in the hydraulic circuit, a pressure reducing valve and a proportional control valve are usually used.

Moreover, in order to make the cutting depth control of the band saw blade practical, the operator must set two valves, a pressure reducing valve and a proportional control valve, according to the workpiece to be cut, and a considerable amount of experience is required to set these valves. Ru.

(Problem to be Solved by the Invention) By the way, when setting the conventional pressure reducing valve and proportional control valve as described above, if the settings are excessive, there is a risk of product failure due to early breakage of the bandsaw blade or occurrence of cut bending. As a result, workers tend to reduce the settings, and the reality is that the machine's performance is not fully utilized.

In addition, the control flow rate of the proportional control valve that controls the cutting speed is proportional to the square root of the inflowing pressure, so even if the thrust force increases, it will only be effective at the square root, resulting in excessive load on the bandsaw blade and bending. This may cause damage or prevent the product from cutting quickly.

When a band saw blade is new, the thrust force is small, so it does not change much in response to changes in cutting length, so feedback is not effective.
Where the cutting length is long, stress will be placed on the band saw blade.

As the band saw blade ages and the tooth tips wear out, the thrust force changes significantly as the cutting length changes. For this reason, when the cutting length is long, it is not possible to make an appropriate cutting depth, which causes friction and accelerates the wear of the band saw blade.

As described above, there has been a problem in that it is extremely difficult to control the pressure reducing valve and proportional control according to the situation.

An object of the present invention is to provide a control valve suitable for controlling the depth of cut of a cutting machine, for example, and to automatically control the depth of cut of a cutting tool using the control valve, in order to improve the above-mentioned problems. An object of the present invention is to provide a cutting depth control device for a cutting machine.

(Structure of the Invention) (Means for Solving the 12 Problems) In order to achieve the above object, the present invention provides a spool that is movable back and forth within the body of a control valve, and an orifice that fits into the spool. A control valve is constructed in which the orifice structure is formed in such a shape that the flow rate gradually increases as the spool moves forward at first, and when the spool advances beyond a certain position, the flow rate increases rapidly.

The present invention also provides a hydraulic cylinder for moving a cutting tool in the cutting direction in a cutting machine, and a control valve for controlling the cutting of the cutting tool in a hydraulic circuit that advances and retreats a rod of the hydraulic cylinder in the cutting direction. established,
A spool that can move back and forth is installed inside the control valve body,
A sleeve with an orifice fitted into the spool is provided, and the orifice is formed into a shape in which the flow rate gradually increases as the spool initially moves forward, and the flow rate increases rapidly when the spool advances beyond a certain position. A cutting control device for a cutting machine was constructed.

(Operation) By employing this invention, in this control valve, as the spool initially moves forward, the orifice provided in the sleeve opens and the flow rate gradually increases.

When the spool advances beyond a certain point, the orifice opens wider and the flow rate increases rapidly.

Thus, the flow rate is adjusted by automatically controlling the degree of opening of the orifice.

Further, by providing a hydraulic cylinder that moves the cutting tool in the cutting machine in the cutting direction, and providing a control valve having the above-mentioned configuration in the hydraulic circuit that moves the rod of the hydraulic cylinder forward and backward in the cutting direction, the control valve By automatically controlling the cutting tool, the cutting depth of the cutting tool can be easily and simply controlled.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

First, a control valve according to the present invention will be explained.

Referring to FIG. 1, a shaft 5 having a male thread 5A is provided in the 0 portion of the body of the control valve CV, extending in the left-right direction in the front-rear direction in FIG. The rear left side of the shaft 5 in FIG. 1 is rotatably supported by the body 1 via a bearing 7.

A spool 9 having a female thread 9A screwed into the male thread 5A is fitted onto the shaft 5, and the front side of the spool 9 on the right side in FIG.
The spool 9 is supported by the shaft 5 so that the spool 9 can move in the left-right direction in the front-back direction in FIG. 1 with respect to the shaft 5.

The spool 9 includes a sleeve 1 having an orifice 13.
A plurality of gaskets 17 are provided between the spool 9 and the sleeve 15 to maintain airtightness. Moreover, the outer peripheral surface of the sleeve 15 is fitted into the small diameter stepped hole 3A of the body 1.

A ring member 19 is attached to the left side of the spool 9 in the front and rear stepped holes 3, and a spring 21 is interposed between the ring member 19 and the side wall of the body 1 of the stepped hole 3. . The spring 21 serves to press the spool 9 to the left in FIG. 1 and eliminate play in the male thread 5A of the shaft 5.

A detent key 23 is attached to the right side of the spool 9, and the detent key 23 is configured so that the spool 9 is not connected to the shaft 5.
It also plays a role in preventing rotation.

On the front right side of the body 1 in FIG. 1, there is a cover 2.
5 is fixed with a plurality of bolts 27.

Further, an encoder 31 is attached to the right side of the shaft 5 via a coupling 29.

Said body 1. Each of the spool 9 and the sleeve 15 has sleeve holes IH+ and IH in the vertical direction in FIG.
2,9H, 15H+, and 15H2 are formed, and the armhole IH+ and 15H+ and IH2 and 15H2 are communicated with each other. An orifice 13 is provided in the inner wall of the sleeve hole 15H2, and the spool 9 is inserted into the first forward direction, for example.
The orifice 13 opens as it moves to the right in the figure, and the slowing rate between the sleeve holes 15H2 and 9H is adjusted and controlled.

The left side of the body 1 is attached to a support plate 33 with bolts, etc., and the left side of the shaft 5 is located on the rear side of the hole 33H1 formed on the lower side of the support plate 33 in FIG. A gear 35 is fixed to the left side of the shaft 5 with a set screw 37.

A gear 39 is meshed with the gear 35, and the gear 39 is fixed to an output shaft 43 of a drive motor 41 such as a stepping motor or a DC motor with a set screw 45.

The rear part of the drive motor 41 is attached to the hole 33H2 formed on the upper side of the support plate 33 in FIG.
The drive motor 41 is fixed to the support plate 33 with bolts or the like.

With the above configuration, when the drive motor 41 is driven, the gear 39 is rotated via the output shaft 43.

When the gear 39 is rotated, the shaft 5 is rotated through the gear 35.
is rotated. Since the male thread 5A of the shaft 5 and the female thread 9A of the spool 9 are screwed together, by rotating the shaft 5, the spool 9 moves to the right in FIG. 1 when moving forward, or to the left when moving backward in FIG. 1. Moving.

For example, when the spool 9 moves forward, the sleeve hole 9H formed in the spool 9 communicates with the sleeve hole 15H2 via the orifice 13. Therefore, armhole 1H2, 15H2, orifice 1
3. The armholes 9H, 15H+ and 1H+ communicate with each other, and hydraulic pressure flows from the armhole IH2 and is discharged to the armhole 1H+.

The rotation of the shaft 5 is detected by an encoder 31 attached to the front of the shaft 5. Thus, the amount of back-and-forth movement in the spool 9, that is, the flow rate of the hydraulic pressure flowing from the armhole 15H2 to the armhole 9H via the orifice 13 is detected.

Referring to FIGS. 2 and 3, the body 1 has a gear 3.
A brake device 47 is provided to apply a brake to the vehicle. The brake device 47 includes a brake piston 53 mounted in a hole 49 formed in the body 1 via a hollow bushing member 51. Further, a pressing member 55 is attached to the lower side of the hole 49, and the pressing member 5
A brake spring 57 is interposed within the brake spring 5 .

With the above configuration, the brake piston 53 is pressed by the brake spring 57, and when the power is turned off, the drive motor 4
When the holding force of 1 is lost, the gear 35 is pressed and the brake is applied to the gear 35.

Further, when the power is turned on and pressure is applied, the pressure causes the brake piston 53 to return and release the brake.

The structure of the orifice 13 is shaped to obtain a flow rate curve as shown in FIG.

That is, in FIG. 1, the amount by which the spool 9 moves forward is detected by the number of pulses of the drive motor 41, for example, a stepping motor, and as the number of pulses increases, the flow rate gradually increases along the curve X, and the pulse The orifice 13 has a shape that increases rapidly as shown by curve Y when the number exceeds, for example, 4.5×100 pulses.

Therefore, the control valve C can automatically and easily control the flow by controlling the number of pulses of the drive motor 41, for example, a stepping motor, and can control the depth of cut of the cutting tool in the cutting machine. The purpose of the present invention is to provide a control valve suitable for controlling.

FIG. 5 shows another embodiment of the control valve in place of the one shown in FIG. FIG. 5 is almost the same as FIG. 1, and the same parts are given the same reference numerals. 5 differs from FIG. 1 in that an encoder 31 is attached to the shaft 5 via a coupling 29, but the coupling 29 and encoder 31 are removed. In place of the coupling 29 and encoder 31, a prismatic stopper 59 is attached to the support plate 33 with a plurality of bolts 61, as shown in FIGS. 6 and 7. Further, a bin 63 is attached to the gear 39, and a stepping motor is used as the drive motor 41.

With the above configuration, the stepping motor is a motor that rotates according to the number of input oscillation pulses, and the step angle is 0.7
If it is 2 degrees, there will be 500 pulses in 360 degrees. Therefore, since the maximum rotation is less than one rotation, 500 pulses are output, the bottle 63 is brought into contact with the stopper 59, the stepping motor is stepped out, and the original position is confirmed. When the pin 63 hits the stopper 59 and the rotation of the gear 39 is stopped, the rise of the current when the stepping motor steps out is detected and the pulse is cut. After confirming the original position, it is moved forward and the same operation as explained in FIG. 1 is performed, and the same effect can be obtained.

Next, a cutting control device for a cutting tool as a cutting machine using the control valve CV will be explained. In this embodiment, a horizontal band saw is used as an example of a cutting machine, and a band saw blade is used as a cutting tool.

Referring to FIG. 8, a work table 61 on which a workpiece W, such as a bar material, for example, is placed is provided on a base (not shown) of the horizontal bandsaw machine 59. A fixing vise device M63 for clamping the workpiece W is attached to the work table 61.

Further, on the base, a substantially C-shaped saw blade housing (not shown) is supported via a hinge pin 65 so as to be rotatable in the vertical direction.

More specifically, the tip of the piston rod lower is connected to an appropriate position of the saw blade housing, and the work table 61 is provided with a swing cylinder 69.

Further, a gear 71 is integrally provided on the hinge bin 65, and a rotary encoder 75 having a gear 73 that meshes with the gear 71 is provided at an appropriate position.

Therefore, the number of pulses corresponding to the rotation of the saw blade housing is detected by the rotary encoder 75, and the number of pulses corresponding to the rotation of the saw blade housing is detected by the central processing unit 81 of the control device 79 via the interface 77.
(hereinafter referred to as CPU), the vertical position and rotation angle of the saw blade housing are accurately detected. Furthermore, the cutting position and cutting speed of the band saw blade T are detected based on the rotation angle.

Inside the saw blade housing, a drive wheel 83 and a driven wheel 87 are rotatably provided via a drive shaft 85 and a rotation shaft 89, respectively. In addition, the drive shaft 8
5 is operatively connected to a rotating shaft 95 of a rotating device 93 such as a motor via a connecting member 91 such as a chino or a belt.

An endless band saw blade (2) is wound around the driving wheel 83 and the driven wheel 87. The saw blade housing includes
A guide 97 is provided to guide and support the bandsaw blade T perpendicularly to the workpiece W in the cutting region.

Therefore, in the horizontal bandsaw machine 59, the rotating device 93
By appropriately rotating and driving the band saw blade T, the band saw blade T can be driven to travel via the connecting member 91, the driving wheel 83, and the driven wheel 87, thereby cutting the workpiece W.

Also, supplying pressure oil into the swing cylinder 69,
By projecting the piston rod 67, the saw blade housing can be rotated upward. Then, by switching the oil passage and discharging the pressure oil in the swing cylinder 69 using ff1ffl of the saw blade housing, the saw blade housing can be rotated downward.

By the way, when cutting the work material W, cutting resistance is generated. This cutting resistance consists of a principal force and a thrust force, and considering that it is related to the rigidity of the workpiece W, the back force and principal force of the cutting resistance are calculated under the same cutting conditions. By detecting this, the rigidity of the workpiece W can be detected.

Referring to FIG. 8, the guide 97 is provided with a load detection device 99 for detecting thrust force.

More specifically, a roller presser 101 for pressing the back of the bandsaw blade T is provided below the guide 97. This roller presser 101 is provided with a roller 103 that can be moved freely, and a lifting bar 1 that is elastically loaded with a spring 105.
07 is provided. This lifting bar 107 is provided with a load sensor 109 that can detect a signal corresponding to the thrust force of the cutting resistance.

Therefore, when the roller 103 is brought into contact with the bandsaw blade T, the spring 105 and the roller presser foot 101 are brought into contact.

Then, when the work material W is cut under cutting conditions with a small load, the roller presser 101 rises against the biasing force of the spring 105 due to the thrust force, and the load sensor 10
9 detects a signal corresponding to the thrust force, and this signal is input to c p u s , i via the interface 111, and after being subjected to appropriate arithmetic processing, the thrust force of the cutting resistance is detected and displayed.

Next, in order to detect the main component force of the cutting resistance, which is one of the component forces of the cutting resistance, a rotation sensor 113 is provided on the rotation shaft 95 of the rotating device 93, and the rotation speed is detected by the rotation sensor 113. By detecting this, the saw speed can be detected. . The rotation sensor 113 is provided because the rotation speed of the rotation device 930 changes depending on the principal component force.

Therefore, when cutting the workpiece W under cutting conditions with a small load, the band saw blade T
1. That is, the rotation speed of the rotating device 93 changes, a signal corresponding to the principal force is detected by the rotation sensor 113, this signal is input to the CPU 81 via the interface 115, and is subjected to appropriate arithmetic processing to determine the cutting resistance. The principal component of force is detected and displayed.

Alternatively, it is also possible to provide an ammeter 117 in the rotating device 93 in order to measure the principal force component of the cutting resistance. This is because the current flowing through the rotating device 93 changes due to a change in the principal component force.

Therefore, when the work material W is being cut, the current flowing through the rotating device 93 changes due to the main force of the cutting resistance, and the ammeter 117 detects a signal corresponding to the main force, and this signal is transmitted to the interface. 119 to the CPLJ 81, and after being subjected to appropriate arithmetic processing, the principal force of the cutting resistance is detected and displayed.

A clock 121 is connected to the CPU 81, and the clock 121 can measure the cutting time when cutting the workpiece W with the horizontal band saw machine 59.

A cut/bend detection device 123 such as a magnetic sensor is provided on one side of the guide 97, and the cut/bend amount of the band saw blade T is detected by the cut/bend detection device 123.

The detected amount of bending is input to the CPU 81 via the interface 125.

A piping 127 is provided in the cylinder chamber of the swing cylinder 69.
The other end of the pipe 127 is connected to the B boat of a 4-bot, 3-position electromagnetic directional switching valve 131 via a check valve 129. Solenoid directional valve 1
31 is equipped with solenoid valves SQL+ and 5OL2. The P boat of the electromagnetic directional control valve 131 is connected to a hydraulic drive source via a pipe 133.

The T-boat of the electromagnetic directional control valve 131 is connected to a tank 137 via a pipe 135. Also, one end of a pipe 139 is connected to a branch from the middle of the pipe 127, and the pipe 13
The other end of 9 is communicated with the tank 137. Piping 1
Filters 141 . A pilot check valve 143 and a control valve Cv of the present invention are provided. A drive motor 41 for controlling the control valve CV is connected thereto. One end of a pipe 145 is connected to the A boat of the electromagnetic directional control valve 131, and the other end of the pipe 145 is connected to the pilot check valve 143. The drive motor 41 of the control valve CV is connected to the CPU 81 via an interface 147.

With the above configuration, when the solenoid valve 5OL2 of the electromagnetic directional control valve 131 is operated, hydraulic pressure is applied from the hydraulic drive source to the pipe 133. It is sent to the cylinder chamber of the swing cylinder 69 via the check valve 129 and piping 127. The piston rod 67 then rises, and the band saw blade T rises via the saw blade housing.

When the solenoid valve SOL+ of the electromagnetic directional control valve 131 is switched and activated, hydraulic pressure is transmitted from the cylinder chamber of the swing cylinder 69 to the piping 127, 139° filter 141. It is returned to tank 137 via pilot check valve 143 and control valve Cv.

At this time, the amount of descent of the piston rod 67 of the swing cylinder 69 is controlled by controlling the flow rate of the control valve Cv. That is, the cutting depth of the band saw blade T is controlled via the saw blade housing.

The flow rate of the control valve C2 is already controlled by the flow rate curve as shown in FIG. 4 through the orifice 13. That is, when the spool 9 first moves forward, the flow rate increases gradually, and when it reaches a certain position, the flow rate increases rapidly. Therefore, the depth of cut can be controlled by controlling the flow rate of the control valve C2 by controlling the drive motor 41 of the control valve C2 according to the cutting speed and saw speed of the horizontal bandsaw machine 59.

For example, the CPU 81 includes a cutting speed/memory 149 and a sawing speed/memory 15 that store the optimum cutting speed and sawing speed based on information on the material, shape, and size of the workpiece W.
1 is connected. Therefore, when the workpiece material W is set,
In CPLI81, cutting speed/memory 149. The optimum cutting speed and saw speed stored in the saw speed/memory 151 and the rotary encoder 752 during the actual cutting process.
Compare the actual cutting speed and saw speed that are calculated based on the number of rotations per rotation angle detected by the rotation sensor 113,
The cutting amount of the band saw blade T is automatically controlled by sending a command signal to the drive motor 41 of the control valve C■ to control the control valve CV so that the actual cutting speed, sawing speed or the optimum cutting speed, sawing speed is achieved. It can be easily and easily controlled.

In the case of general machine tools such as lathes and milling machines, cutting is generally controlled to keep the cutting speed and depth of cut constant, but in band saws, the body of the band saw blade, which is the cutting tool, is weak. Therefore, there is a limit to the load that the torso can withstand. Furthermore, all the chips that have been cut from the start of the cut to the end of the cut must be contained in the gullet, but this naturally has its limits.

Therefore, with a band saw, it is preferable to control the product of the cut flaw and the cutting length rather than keeping it constant.

Therefore, in this embodiment, the cutting length is determined by a calculation formula, the work material W is a round material, and the swing method of the horizontal bandsaw machine 59 shown in FIG. 8 is used to control the product of the depth of cut and the cutting length. An example will be explained below.

Referring to FIG. 9, the rotation center of the bandsaw blade T is set at the origin 0 (0
, 0), the radius of the workpiece W is r, the distance between the vice surface and the origin O is a, and the distance from the reference vice surface is b.

The equation for the work material W is (X + b + r )2 + (y - a - r )2
= r2... (1) The equation for the band saw blade T is: y=-tanθ・X... (2) (where θ: rotation angle of the band saw blade T) From the above equations (1) and (2), the band saw blade T If the X coordinates of the intersection of the blade T and the workpiece W are XI and X2, then the long hair cut by the band saw blade T is expressed as A=(XI-X2)/c'osθ.

Assuming that the bandsaw blade T descends by dθ in 8 hours, the depth of cut H becomes:

Therefore, if Δ is the product of the cutting depth ff1H in time and the long hair cut (area = amount of work), then the product of the cutting depth ff1H per unit time and the long hair cutting is the product of the depth of cut IH and the long hair cutting. To control to keep it constant, d A
/dt=C (constant).

A signal is output from the CPU 81 so that the control valve C
All you have to do is control v. Note that since the cutting speed becomes infinite at the start and end of cutting when the long hair is cut, it is necessary to apply a limiter.

The angle θ is detected by the rotary encoder 75 described above.

In addition, encoder detection can be performed not only at the center of rotation of the band saw blade T, but also at the swing cylinder 69, for example, using the rack, knife, chain, and sprocket.

I won't buy it even if I detect it using a linear scale or other means.

It is a hot theory that the control valve Cv should be temperature compensated, but since it is impossible to create one that is completely unaffected by temperature, the oil temperature is kept at a constant temperature. Moreover, since the control valve Cv has manufacturing variations, it is necessary to make the machine learn the flow rate characteristics of the control valve Cv shown in FIG. 4. The means for this is to retreat to the Z-phase output (output once per rotation) of the encoder 31 explained in FIG. 1, confirm the original position, and then stop.

Note that the above-mentioned operation is not necessary if the encoder is an absolute encoder rather than an incremental encoder. However, the absolute type is expensive, so to explain it in terms of the incremental type, once the origin is confirmed, it is moved forward, and the flow rate is calculated every specified pulse, for example, every 50 pulses, and the amount of descent of the bandsaw blade T and d.
The number of pulses per unit time θ/dt is learned. The lowering of the band saw blade T between designated pulses is calculated by ignoring this interval as a straight line.

In actual operation, the CPU 81 sequentially controls the drive motor 41 from the learned content to the pulse command of the encoder 31 corresponding to the required amount of descent.

In the case of the control valve Cv shown in Fig. 5, after confirming the original position, move the model forward and learn the flow rate for each specified pulse and the lowering of the band saw blade T, that is, the pulse and pulse per unit time of dθ/dt. let The amount of fall between specified pulses is calculated by regarding this period as a straight line.

Referring again to FIG. 8, the CPU 81 has a
A target cutting time/memory 153 is connected which stores target cutting times set depending on the material, shape, and size of the machine. Therefore, the CPU 81 calculates the target cutting time and
The target cutting time stored in the memory 153 and the clock 1
21 is compared with the actual cutting time measured by 21.

Now, if the cross-sectional area of the workpiece W is A, and the average cutting length per unit time x depth of cut (average cutting rate) is C, the target cutting time tc is tc=A/C.

If the actual cutting time is tl, then in the next cutting,
Correct j+/lc and control with .

If the cutting time for the second cut is 12, the next target cutting length per unit time x depth of cut is dA/dt=C・(t
+/lC) ・(t2/lc). If the cutting time of the n-th cut is tn, then the target cutting length per unit time of the n-th cut x depth of cut is: In other words, the previous cutting time and the target cutting time tc are successively compared and feedback is applied. By adopting this method, it is possible to eliminate variations caused by the temperature of the control valve C2.

Furthermore, this allows the operator to predict the time to complete cutting by adding air cuts and the like based on the input number of pieces to be cut and the target cutting time.

The method for predicting the time to complete cutting will be explained assuming that the workpiece W is a round material.

When the diameter of the workpiece W is ``, the long hair to be cut, and the number of pieces to be cut is n, and these are input into cpuai, the cross-sectional area A is first calculated. Also, from the input material, the average cutting length per unit time x the cutting depth The amount is processed within the CPU 81.

The feed speed is t, the rising speed of the band saw blade T is ``F+, the band saw blade T
The rising side overtravel. , the sudden descent speed is Vd, the total operation timing time is tχ, and the predicted cutting completion time is T
If the end is cut, it will automatically start from the rising end.

Therefore, T= (n +1) (A+4) +. (jE−+
h) t=VcL C so v/LA becomes.

By the above calculation, the expected cutting completion time T can be displayed.

Next, the cutting speed at the time of starting cutting and just before the completion of cutting will be explained.

If the above-mentioned depth of cut and width of the cutting length are controlled to be constant, the depth of cut may exceed the strength of the band saw blade T where the cutting length becomes short, so some kind of regulation is necessary.

The saw speed is /1n, the saw blade pitch is epmm, the depth of cut is Szsm/sea, the cutting length is 12mm, the number of passing teeth is n/SeC, and the cutting rate is Rare210Iin.
, - If the depth of cut per tooth is lzw+m, then the depth of cut fM 5x=10R/6L-x.

Zunawara - The hardness of the cut per tooth is related to the ease of cutting (machinability) of the work material W, and the easier it is to cut, the more the depth of cut per tooth can be increased. On the other hand, if the cutting ease is low, it is necessary to reduce the depth of cut per tooth.

Therefore, the depth of cut per tooth is determined for each material.

When the workpiece W is a round material, as shown in FIG. 10, the cutting rail, which is the product of the depth of cut and the cutting length, is controlled to be constant so that the depth of cut does not exceed 1k.

Note that the present invention is not limited to the embodiments described above, and can be implemented in other embodiments by making appropriate changes.

〔Effect of the invention〕

As can be understood from the above description of the embodiments, in the control valve according to the present invention, as the spool initially advances, the orifice provided in the sleeve opens and the flow rate gradually increases, and when the spool advances beyond a certain position, the orifice opens. opens wider and the flow rate increases rapidly. therefore,
Unlike conventional proportional control valves, the flow rate can be adjusted by automatically, simply and easily controlling the degree of opening of the orifice. Therefore, when this control valve is applied to control the cutting depth of the cutting tool of a cutting machine,
It is effective because the depth of cut of the cutting tool can be easily and easily controlled automatically.

[Brief explanation of the drawing]

Fig. 1 is a front sectional view of a control valve that is an embodiment of the present invention, Fig. 2 is a view taken in the direction of the ■ arrow in Fig. 1, and Fig. 3 is a sectional view taken along the line m-■ in Fig. 2. be. FIG. 4 is a flow curve diagram showing the degree of opening of the orifice, which is the main part of the present invention. FIG. 5 is a front view of a control valve of another embodiment in place of FIG. It is a diagram. Figure 8 is a block diagram of a horizontal band saw using the control valve of the present invention, Figure 9 is an explanatory diagram for controlling the angular velocity of the band saw blade, and Figure 10 is for controlling the product of cutting depth and cutting length. It is an explanatory view explaining control of cutting speed at the time of starting cutting and just before completing cutting when cutting. Cv...control valve, 9...spool, 13...orifice, 15...sleeve, 31...encoder,
41... Drive motor, 59... Horizontal band saw machine, 67...
... Piston rod, 69 ... Swing cylinder, 7
5... Rotary encoder representative Yasuo Miyoshi, patent attorney Figure 3

Claims (2)

[Claims] (1) A spool movable back and forth is provided in the body of the control valve, and a sleeve with an orifice fitted to the spool is provided, and the structure of the orifice is such that as the spool initially moves forward, the flow rate gradually increases. A control valve characterized in that the flow rate increases rapidly when the spool advances beyond a certain position. (2) providing a hydraulic cylinder for moving the cutting tool in the cutting direction in the cutting machine, and providing a control valve for controlling the cutting of the cutting tool in a hydraulic circuit that moves the rod of the hydraulic cylinder forward and backward in the cutting direction; A spool movable back and forth is provided in the body of the control valve, and a sleeve is provided with an orifice fitted into the spool, and the structure of the orifice is such that as the spool initially moves forward, the flow rate gradually increases and the spool A cutting control device for a cutting machine, characterized in that the cutting machine is formed in a shape that rapidly increases a flow rate when the cutting machine advances beyond a certain position.