band saw

Abstract

To provide a bandsaw capable of efficiently and automatically adjusting, a drive speed, without experienced techniques.SOLUTION: A bandsaw 10 comprises: an endless saw blade 24; a pair of wheels 26 to which the saw blade is wound; cutting means 20 having a rotation motor 28 which is connected to one wheel and is rotated; and feeding means 30 having a feeding motor 32 which moves the cutting means in a cutting direction. The bandsaw further comprises: a vibration measurement sensor 40 for detecting vibration which is generated in the cutting; a saw blade vertical position measurement sensor 50 for detecting a height position of a saw blade; a saw blade horizontal position measurement sensor 51 for detecting a horizontal position of the saw blade; a determination part 60 for comparing a measured value with a vibration set value of the vibration measurement sensor, a measured value with a saw blade height change set value of the saw blade vertical position measurement sensor, and a measured value with a saw blade position set value of the saw blade horizontal position measurement sensor; and a control part 70 for, on the basis of determination by the determination part, controlling at least one of a rotation speed of the rotation motor and rotation speed of the feeding motor.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a band saw that cuts large structures using an endless saw blade. [Background technology]

[0002] Band saws with endless saw blades are used in the demolition of large structures such as large-diameter pipes. Since the wrong operating speed can cause problems such as chipping of the saw blade, band saws are difficult to adjust, and are therefore operated by experienced, skilled operators. Due to the aging and declining number of skilled operators, and the time it takes to learn and develop optimal operating speeds, there are currently technologies available that automatically adjust various operating speeds.

[0003] The band saw disclosed in Patent Document 1 detects the load of the band saw at the continuously changing cutting depth from the start to the end of the cutting process, and performs cutting according to a pre-set optimal cutting pattern, i.e., cutting at the highest feed rate within the range that does not cause damage such as chipping to the workpiece.

[0004] The wafer band saw disclosed in Patent Document 2 detects increases or decreases in cutting resistance during cutting from increases or decreases in the amount of power supplied to the first motor that rotates the saw blade, and controls the cutting speed of the second motor that raises and lowers the saw blade to increase or decrease depending on the increases or decreases in cutting resistance or power consumption. However, with the technology of Patent Document 1, if the shape of the workpiece to be cut is known in advance, it is possible to determine the setting value for the maximum feed rate, but it is difficult to obtain the setting value in advance for the various shapes of workpieces that are generated at demolition sites, etc. Furthermore, with the technology of Patent Document 2, if the motor output used when dismantling a large structure is excessive relative to the load, it is impossible to detect minute changes in cutting resistance, and the cutting speed cannot be controlled. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2-214608 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-28620 Summary of the Invention [Problem to be solved by the invention]

[0006] In view of the problems of the prior art described above, the problem that the present invention aims to solve is to provide a band saw that can automatically adjust the operating speed efficiently even without experienced skills, and automatically maximize the feed speed while avoiding damage or twisting of the saw blade. [Means for solving the problem]

[0007] As a first means for solving the above-mentioned problems, the present invention provides a cutting means having an endless saw blade, a pair of wheels around which the saw blade is hung, a rotation motor connected to one of the wheels for rotating the same, and a cutting apparatus for cutting the cutting means. Up and down In a band saw equipped with a feed means having a feed motor that moves in the cutting direction, A vibration measurement sensor that detects vibrations generated during cutting; a saw blade vertical position measurement sensor that detects the height position of the saw blade; a saw blade horizontal position measuring sensor for detecting the horizontal position of the saw blade; a determination unit that compares the measurement value of the vibration measurement sensor with a vibration set value, the measurement value of the saw blade vertical position measurement sensor with a saw blade height change set value, and the measurement value of the saw blade horizontal position measurement sensor with a saw blade position set value; The object of the present invention is to provide a band saw characterized by comprising a control unit that controls at least one of the rotation speed of the rotating motor and the rotation speed of the feed motor based on the determination of the determination unit. According to the first means, it is possible to perform control so that the peripheral speed or feed speed becomes optimal based on physical changes such as frame vibration and positional deviation of the saw blade.

[0008] As a second means for solving the above problem, the present invention provides a band saw characterized in that, in the first means, the saw blade vertical position measurement sensor is a laser sensor attached to the lifting frame of the cutting means to detect the height position of the saw blade. According to the second means, it is possible to determine from the detected value of the height position of the saw blade that the saw blade is slipping away in the direction opposite to the feed direction (hereinafter referred to as cutting delay).

[0009] As a third means for solving the above problem, the present invention provides a band saw 10 characterized in that, in the first means, the saw blade horizontal position measurement sensor is a laser sensor attached to the lifting frame of the cutting means to detect the horizontal position of the saw blade. According to the third means, the occurrence of twisting or bending of the saw blade can be detected from the detected value of the horizontal position of the saw blade.

[0010] As a fourth means for solving the above problem, the present invention provides a band saw characterized in that, in any one of the first to third means, the vibration measuring sensor is provided at the connection point between the pillar of the frame body to which the feed means is attached and the upper frame. According to the fourth means, when vibration of the saw blade occurs, it can be easily detected on the frame body.

[0011] As a fifth means for solving the above problem, the present invention provides a band saw characterized in that, in any one of the first to fourth means, a judgment unit judges signs of saw blade breakage from the measurement value of the vibration measurement sensor and the vibration setting value, and based on the judgment of the judgment unit, a control unit controls at least one of the rotation speed of the rotation motor and the rotation speed of the feed motor, thereby maximizing the feed speed while avoiding saw blade breakage. According to the fifth means, it is possible to determine signs of saw blade breakage based on physical changes such as frame vibration and positional deviation of the saw blade, and to perform control to maximize the peripheral speed or feed rate. [Effects of the Invention]

[0012] According to the present invention, it is possible to perform control so that the peripheral speed or feed speed is optimized based on physical changes such as frame vibration and positional deviation of the saw blade. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic diagram of the configuration of a band saw according to the present invention. [Figure 2] FIG. 10 is an explanatory diagram of a saw blade vertical position measurement sensor that detects the height position. [Figure 3] FIG. 4 is an explanatory diagram of a saw blade horizontal position measuring sensor that detects the horizontal position. [Figure 4] FIG. 1 is a process flow diagram using the band saw of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a band saw according to the present invention will be described in detail below with reference to the drawings.

[0015] [Band Saw 10] FIG. 1 is a schematic diagram showing the configuration of a band saw according to the present invention. The band saw 10 of the present invention comprises a frame body 12, an endless saw blade 24, a pair of wheels 26 around which the saw blade 24 is wound, cutting means 20 having a rotation motor 28 connected to one of the wheels 26 to rotate it, feeding means 30 having a feed motor 32 that moves the cutting means 20 in the cutting direction, a vibration measuring sensor 40 that detects vibrations acting on the saw blade 24 during cutting, a saw blade vertical position measuring sensor 50 that detects the height position of the saw blade 24, a saw blade horizontal position measuring sensor 51 that detects the horizontal position of the saw blade 24, a determination unit 60 that compares the measurement value of the vibration measuring sensor 40 with a vibration set value, the measurement value of the saw blade vertical position sensor 50 with a saw blade height change set value, and the measurement value of the saw blade horizontal position measuring sensor 51 with a saw blade position set value, and a control unit 70 that controls at least one of the rotation speed of the rotation motor 28 and the rotation speed of the feed motor 32 based on the determination of the determination unit 60.

[0016] The frame body 12 has upper and lower frames 13, 14 that are rectangular in plan view, and four pillars 15 located at the four corners between the upper and lower frames 13, 14, forming an overall rectangular parallelepiped shape. The frame body 12 is provided with a cutting means 20, a feeding means 30, etc.

[0017] The cutting means 20 has a saw blade 24, a pair of wheels 26, a rotation motor 28, and a lifting frame 29 on which these are arranged. The lifting frame 29 is a frame that moves up and down along the pillars 15 of the frame main body 12, and can lower the saw blade 24 to cut the material to be cut. A pair of lifting frames 29 are provided on both ends of the frame main body 12 in the longitudinal direction. The pair of lifting frames 29 are fitted with sliders that engage with guide rails arranged on the pillars 15.

[0018] The feed means 30 has a ball screw 33, a lifting slider, and a feed motor 32, and moves the lifting frame 29 up and down along the pillars 15. The ball screw 33 is erected along the pillars 15, outside the pillars 15 of the frame body 12. The lifting slider arranged on the lifting frame 29 engages with the ball screw 33 and moves up and down along the longitudinal direction of the ball screw 33 in accordance with the rotation of the ball screw 33. The feed motor 32 is a drive source that rotates the ball screw 33. Such a feed means 30 is arranged on each frame of the pair of lifting frames 29, and by synchronously controlling the feed motors 32, the saw blade 24 on the lifting frame 29 can be raised and lowered while rotating in a horizontal plane.

[0019] The vibration measuring sensor 40 is an acceleration sensor that is disposed on the frame main body 12 and detects vibrations that occur during cutting. More specifically, the vibration measuring sensor 40 is attached at the intersection, i.e., the connection point, between the top end of the pillar 15 of the frame main body 12 and the upper frame 13. The measurement direction of the vibration measuring sensor 40 is along the longitudinal direction of the frame main body 12. Such a vibration measuring sensor 40 can detect vibrations occurring during cutting with high sensitivity at the upper part of the frame body.

[0020] The saw blade vertical position measuring sensor 50 is a laser sensor that detects the height position of the saw blade 24, and the saw blade horizontal position measuring sensor 51 is a laser sensor that detects the horizontal position of the saw blade 24. Both are disposed on a fixture 52 attached to the lifting frame 29. The fixture 52 moves up and down together with the lifting frame 29.

[0021] Figure 2 is an explanatory diagram of a saw blade vertical position measurement sensor that detects the height position. In this figure, the saw blade 24 rotates in a direction perpendicular to the paper surface. The sensor that detects the height position of the saw blade 24 is a pair of laser sensors positioned to sandwich the upper end of the saw blade 24. When the upper end of the saw blade 24 moves upward due to the band-like laser irradiation, the laser irradiation is blocked and the irradiation amount changes, so the height position of the saw blade 24 can be detected. This makes it possible to check for cutting delays of the saw blade 24.

[0022] Figure 3 is an explanatory diagram of the saw blade horizontal position measurement sensor that detects the horizontal position. In this figure, the saw blade 24 rotates in a direction perpendicular to the paper surface. The sensor that detects the horizontal position of the saw blade 24 is a laser displacement sensor positioned opposite the side of the saw blade 24 so that it can irradiate the side with a laser. The laser irradiation detects the distance between the side of the saw blade 24 and the sensor. When this detected distance exceeds the set saw blade position value, a load is applied from the vertical position of the saw blade 24, causing a horizontal position deviation that twists the saw blade 24, and a bent cut can be detected.

[0023] The determination unit 60 compares the measurement value of the vibration measurement sensor 40 with the vibration set value, the measurement value of the saw blade vertical position measurement sensor 50 with the saw blade height change set value, and the measurement value of the saw blade horizontal position measurement sensor 51 with the saw blade position set value. The vibration setting value is set to a value several times the vibration value of the saw blade 24 in a stable state, or a value that occurs before the saw blade 24 is broken. The saw blade height change setting is the difference between the latest and previous saw blade height average values ​​calculated from measurements taken over a specified period of time. This difference changes rapidly when the feed speed is changed and gradually approaches zero over time. The saw blade height change setting is set to less than half the automatic feed acceleration rate. For example, when the automatic feed acceleration rate is 0.25 mm / min, the average change threshold is set to 0.125 mm. The saw blade position setting is also set to exceed the horizontal position fluctuation range (±0.5 mm) during normal cutting, as confirmed in tests.

[0024] Based on the determination by the determination unit 60, the control unit 70 controls at least one of the rotation speed of the rotation motor 28 and the rotation speed of the feed motor 32. Specifically, the control unit 70 sends control signals to the inverter of the rotation motor 28 and to the servo amplifier of the feed motor 32, respectively, to control the respective speeds.

[0025] [Decision flow] The determination flow using the band saw of the present invention with the above configuration will be described below. Figure 4 is a process flow diagram using the band saw of the present invention. (Step 1) During operation of the band saw 10 of the present invention, the saw blade horizontal position measuring sensor 51 collects the saw blade position for a predetermined time, which in this embodiment is one second. (Step 2) It is determined whether or not the measurement value of the saw blade horizontal position measuring sensor 51 exceeds the saw blade position setting value.

[0026] (Step 3) When the measured value is equal to or greater than the set saw blade position, the saw blade 24 is not in a stable cutting state (steady state) and is bending the saw blade 24. In this case, accelerating the feed speed and rotation speed will have a significant effect on defects in the saw blade 24, so the feed motor 32 is stopped and the rotation motor 28 is kept running. Operation is continued for a predetermined time. (Step 4) It is again determined whether or not the measurement value of the saw blade horizontal position measuring sensor 51 has exceeded the saw blade position setting value.

[0027] (Step 5) When the measured value is equal to or greater than the set saw blade position value, the machine is not in a steady state and excessive cutting bending is occurring. Therefore, if the machine continues in this state, there is a high possibility that a malfunction such as damage to the saw blade will occur eventually. Some kind of inspection and maintenance of the saw blade 24 is required, and operation is stopped. (Step 6) If the measured value has not reached the set saw blade position value, the cutting bend of the saw blade 24 tends to decrease due to continued operation for a predetermined period of time, so the feed motor 32 is set to a slower speed (for example, 0.25 mm / min).

[0028] (Step 7) The feeding of the saw blade 24 is resumed to perform cutting, and step 1 and subsequent steps are repeated. (Step 8) When the measured value does not reach the saw blade position setting, bending of the saw blade 24 is not occurring. During operation of the band saw 10 of the present invention, vibrations are collected by the vibration measuring sensor 40 and the height of the saw blade is collected by the saw blade vertical position measuring sensor 50 for a predetermined time, 30 seconds in this embodiment.

[0029] (Step 9) It is determined whether or not the measurement value of the vibration measuring sensor 40 exceeds the vibration set value. The determining unit 60 determines whether or not there is a sign of saw blade breakage from the measurement value of the vibration measuring sensor 40 and the vibration set value. (Step 10) If the measured value does not reach the vibration setpoint, the change in height of the saw blade 24 is checked. When the height exceeds the predetermined saw blade height change setting value, the steady state is not maintained and a delay in saw blade cutting occurs, and increasing the saw blade feed speed places an excessive load on the saw blade, so steps 1 and onward are repeated.

[0030] (Step 11) When the change in height of the saw blade 24 has not reached the set value for the change in height of the saw blade 24, the feed speed of the saw blade 24 can be accelerated in a steady state. It is determined whether or not the upper limit of the feed speed of the saw blade 24 has been reached. If the upper limit has already been reached, steps 1 and thereafter are repeated. (Step 12) If the upper limit of the feed speed of the saw blade 24 has not been reached, the feed speed is increased (for example, by +0.25 mm / min), and step 1 and subsequent steps are repeated.

[0031] (Step 13) When the measured value reaches the vibration setting value, the frequency of exceeding the vibration setting value is checked. The frequency is calculated by counting how many times the vibration setting value is exceeded in a predetermined time. In this embodiment, as an example, the vibration exceeding setting value is set to 30 times that the vibration setting value is exceeded in a predetermined time (e.g., 30 seconds). (Step 14) When the vibration exceeds the set value, steady vibration occurs. Therefore, the feed rate is reduced and steps 1 and after are repeated.

[0032] (Step 15) When the vibration excessive setting value is not reached, sudden vibration of the saw blade 24, which is a sign of saw blade breakage, occurs, and the feed rate is excessive. On the other hand, steady vibration is not occurring, and the saw blade 24 can be operated at the upper limit of its rotational speed. It is determined whether the rotation speed of the saw blade 24 has reached an upper limit value. (Step 16) If the upper limit has already been reached, the feed rate is reduced and steps 1 and after are repeated.

[0033] (Step 17) If the upper limit of the rotation speed has not been reached, the rotation speed is accelerated and steps 1 and after are repeated.

[0034] According to the present invention, signs of saw blade breakage are detected based on the vibration measurement sensor's measurement value and the vibration setting value, and at least one of the rotation speed of the rotation motor and the feed motor is controlled based on this detection, thereby maximizing the feed speed while avoiding saw blade breakage. Furthermore, the peripheral speed or feed speed can be controlled to be optimal based on physical changes such as frame vibration and saw blade misalignment. Furthermore, the operating speed can be automatically and efficiently adjusted, even without extensive experience. Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and various modifications can be made without departing from the spirit and scope of the present invention. Furthermore, the present invention is not limited to the combinations shown in the embodiments, but can be implemented in various combinations. [Explanation of symbols]

[0035] 10 Bandsaw 12 Frame body 13 Upper frame 14 Lower frame 15 pillars 20 Cutting means 24 saw blade 26 wheels 28 Rotation motor 29 Lifting frame 30 Feeding means 32 Feed motor 33 Ball screw 40 Vibration measurement sensor 50 Saw blade vertical position measurement sensor 51 Saw blade horizontal position measurement sensor 52 Fixtures 60 Judgment section 70 Control Unit

Claims

1. A band saw comprising: an endless saw blade; a pair of wheels around which the saw blade is wound; a cutting means having a rotation motor connected to one of the wheels for rotating it; and a feeding means having a feeding motor for moving the cutting means in an up-and-down cutting direction, A vibration measurement sensor that detects vibrations generated during cutting; a saw blade vertical position measurement sensor that detects the height position of the saw blade; a saw blade horizontal position measuring sensor for detecting the horizontal position of the saw blade; a determination unit that compares the measurement value of the vibration measurement sensor with a vibration set value, the measurement value of the saw blade vertical position measurement sensor with a saw blade height change set value, and the measurement value of the saw blade horizontal position measurement sensor with a saw blade position set value; A band saw comprising a control unit that controls at least one of the rotation speed of the rotating motor and the rotation speed of the feed motor based on the determination of the determination unit.

2. 2. The band saw according to claim 1, The band saw is characterized in that the saw blade vertical position measuring sensor is a laser sensor attached to a lifting frame of the cutting means to detect the height position of the saw blade.

3. 2. The band saw according to claim 1, The band saw is characterized in that the saw blade horizontal position measuring sensor is a laser sensor attached to a lifting frame of the cutting means to detect the horizontal position of the saw blade.

4. 2. The band saw according to claim 1, The band saw is characterized in that the vibration measuring sensor is provided at a connection point between a pillar of a frame body to which the feeding means is attached and an upper frame.

5. A band saw according to any one of claims 1 to 4, A band saw characterized in that a judgment unit judges signs of saw blade breakage from the measurement value and vibration setting value of the vibration measurement sensor, and a control unit controls at least one of the rotation speed of the rotation motor and the rotation speed of the feed motor based on the judgment of the judgment unit, thereby maximizing the feed speed while avoiding saw blade breakage.

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