Band saw machine and method for cutting workpiece using band saw blade

Abstract

To provide a band saw machine capable of shortening a cutting length, further suppressing occurrence of a cutting-bending phenomenon, and simplifying a structure that enables oscillating-cutting.SOLUTION: A band saw machine includes a work support unit (6) that supports a workpiece (W), a housing (3) that moves so as to bring a band saw blade (5) into and out of contact with the workpiece (W), and a control device (4) that controls the movement. The housing (3) includes a first guide roller (334) and a second guide roller that guide the band saw blade (5) at separated positions across a cutting position, and a first moving unit (331) and a second moving unit (341) that independently move the guide rollers into and out of contact with the workpiece (W) to change an orientation of the band saw blade (5) between a first inclined posture and a second inclined posture having an angle different from the first inclined posture. The control device (4) cuts the workpiece (W) by changing the orientation of the band saw blade (5) between the first inclined posture and the second inclined posture, and performs the orientation change by moving the housing (3) to a position at which the band saw blade (5) is separated from the workpiece (W).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a band saw and a method for cutting a workpiece with a band saw blade. [Background technology]

[0002] When cutting a workpiece using a band saw, as wear progresses at the tooth tips of the band saw blade, cutting resistance increases, increasing the likelihood of a phenomenon known as bent cutting. A known technique for preventing this bent cutting is called oscillating cutting, in which the band saw blade is oscillated like a seesaw while cutting. Oscillating cutting makes it possible to shorten the cutting length while maintaining the cutting speed. This reduces cutting resistance, slows the progression of wear at the tooth tips, suppresses bent cutting, and extends the life of the band saw blade. Patent Document 1 describes a band saw capable of oscillating cutting.

[0003] The saw blade housing of the band saw machine described in Patent Document 1 includes a pair of wheels around which the band saw blade is wound, and first and second saw blade guide devices that guide the band saw blade at positions spaced apart in the traveling direction across the position where the workpiece is cut. The band saw machine cuts the workpiece by bringing the saw blade housing close to the workpiece and causing the band saw blade to cut into it.

[0004] The first and second saw blade guide devices are provided with first and second insert holders that guide the back of the band saw blade and move in the cutting direction, respectively. With this configuration, the first and second insert holders are alternately moved in the cutting direction during cutting, allowing the band saw blade to oscillate like a seesaw. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-305613 Summary of the Invention [Problem to be solved by the invention]

[0006] The band saw machine described in Patent Document 1 has a structure in which the band saw blade is oscillated by independently moving the first and second insert holders in the cutting direction while cutting into the workpiece. While this structure allows the cutting length of the workpiece by the tilted band saw blade to be shortened to some extent, there is room for improvement in that the cutting length is increased during the band saw blade's position change because the band saw blade is oscillated while cutting, which places a heavy load on certain tooth tips and may result in tooth chipping. Furthermore, the increased cutting length during the band saw blade's position change increases cutting resistance, and the band saw machine must be designed to be sturdy enough to withstand the relatively heavy loads repeatedly applied during position changes. In other words, there is a need for a simplified band saw machine structure that maintains a short cutting length while still allowing the band saw blade to oscillate, thereby further suppressing the occurrence of the bending cut phenomenon. [Means for solving the problem]

[0007] A first aspect of one or more embodiments includes a work support portion that supports a long workpiece, a housing having a pair of wheels on which a band saw blade is hung and which causes the hung band saw blade to travel in a circular motion, and which moves the band saw blade so as to move the band saw blade away from and toward the workpiece supported by the work support portion, and a control device that controls the movement of the housing, wherein the housing includes a first guide roller and a second guide roller that guide the back of the band saw blade at positions spaced apart in the traveling direction across a position where the workpiece is cut, and a first moving unit and a second moving unit that independently move the guide rollers toward and away from the workpiece, and selectively change the position of the band saw blade between the first guide roller and the second guide roller between a first inclined position and a second inclined position that is inclined at an angle different from the first inclined position; and the control device changes the position of the band saw blade between the first inclined position and the second inclined position to cut the workpiece in each position, and changes the position of the band saw blade by moving the housing to a position where the band saw blade is away from the workpiece.

[0008] A second aspect of one or more embodiments is a method for cutting a workpiece using a band saw blade, in which, when cutting a long workpiece with the band saw blade, the band saw blade is changed between a first inclined position and a second inclined position that is inclined at an angle different from the first inclined position, and cutting is performed in each position, and the position change is performed by moving the band saw blade to a position where it is away from the workpiece. [Effects of the Invention]

[0009] According to one or more embodiments of the band saw machine and the cutting method using the band saw blade, the cutting length can be made shorter, thereby further suppressing the occurrence of the bending cut phenomenon and simplifying the structure of the band saw machine capable of oscillating cutting. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a front view showing the configuration of a band saw machine 91 according to one embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram illustrating the structure of the first guide unit 33 in the band saw 91. As shown in FIG. [Figure 3] 3A and 3B are diagrams showing the operation of the first guide unit 33, with FIG. 3A showing the raised state and FIG. 3B showing the lowered state. [Figure 4] FIG. 4 is a block diagram of the band saw 91. [Figure 5A] FIG. 5A is a diagram showing the horizontal position PSH of the band saw blade 5. [Figure 5B] FIG. 5B is a diagram showing the right-tilt position PSR of the band saw blade 5. [Figure 5C] FIG. 5C is a diagram showing the left inclined position PSL of the band saw blade 5. [Figure 6] FIG. 6 is a diagram for explaining an outline of the cutting procedure for the workpiece WA. [Figure 7A] FIG. 7A is a first diagram for explaining the cutting step PA of the workpiece WA. [Figure 7B] FIG. 7B is a second diagram for explaining the cutting step PA. [Figure 7C] FIG. 7C is a third diagram for explaining the cutting step PA. [Figure 7D] FIG. 7D is a fourth diagram for explaining the cutting step PA. [Figure 7E] FIG. 7E is a fifth diagram for explaining the cutting step PA. [Figure 7F] FIG. 7F is a sixth diagram for explaining the cutting step PA. [Figure 7G] FIG. 7G is a seventh diagram for explaining the cutting step PA. [Figure 7H] FIG. 7H is an eighth diagram for explaining the cutting step PA. [Figure 7I] FIG. 7I is a ninth diagram for explaining the cutting step PA. [Figure 8A] FIG. 8A is a first diagram for explaining the cutting step PB of the workpiece WB. [Figure 8B] FIG. 8B is a second diagram for explaining the cutting step PB. [Figure 8C] FIG. 8C is a third diagram for explaining the cutting step PB. [Figure 8D] FIG. 8D is a fourth diagram for explaining the cutting step PB. [Figure 8E] FIG. 8E is a fifth diagram for explaining the cutting step PB. [Figure 8F] FIG. 8F is a sixth diagram for illustrating the cutting step PB. [Figure 8G] FIG. 8G is a seventh diagram for explaining the cutting step PB. [Figure 8H] FIG. 8H is an eighth diagram for illustrating the cutting step PB. [Figure 8I] FIG. 8I is a ninth diagram for explaining the cutting step PB. [Figure 9A] FIG. 9A is a timing diagram excluding the final stage in the cutting step PA. [Figure 9B] FIG. 9B is a timing diagram of the final stage in the cutting step PA. [Figure 10A] FIG. 10A is a diagram showing the first stage of a flow chart illustrating the procedure of the cutting method according to the embodiment. [Figure 10B]FIG. 10B is a diagram showing the middle part of the flow of the cutting process procedure. [Figure 10C] FIG. 10C is a diagram showing the final stage in the flow of the cutting process procedure. DETAILED DESCRIPTION OF THE INVENTION

[0011] The configuration of a band saw machine 91 according to one embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG. 1 is a front view showing the configuration of a band saw machine 91 according to one embodiment of the present invention. FIG. 2 is a schematic diagram illustrating the structure of a first guide unit 33 in the band saw machine 91. FIG. 3 is an operation diagram of the first guide unit 33, with FIG. 3(a) showing it in a raised state and FIG. 3(b) showing it in a lowered state. FIG. 4 is a block diagram of the band saw machine 91. For ease of explanation, the left-right, up-down, and up-down directions are defined as the directions of the arrows in FIG. 1. The front-rear direction is perpendicular to the plane of the paper, and the front of the paper is the front.

[0012] As shown in FIG. 1, the band saw 91 includes a base 1, a housing support 2, a housing 3, and a control device 4.

[0013] The base table 1 is installed on an installation surface FL, and a housing support part 2 having an opening 2a penetrating from front to back is connected and fixed to the top. A work support part 6 is installed in the center of the left-right direction on the top surface of the base table 1. The work support part 6 has a support table 61 that supports a long workpiece W that has been passed through the opening 2a in an orientation extending in the front-to-rear direction, and clampers 62 and 63 that move left and right on the support table 61 to clamp the workpiece W from the left and right. The clamping operation of the clampers 62 and 63 is driven by a clamper drive unit KK.

[0014] The housing support 2 has a lifting drive unit KD. The housing support 2 supports the housing 3 and uses the lifting drive unit KD to lift and lower the housing 3. Figure 1 shows the housing 3 in a raised standby position.

[0015] The housing 3 includes a base 30, a driven wheel 31, a driving wheel 32, a first guide unit 33, and a second guide unit .

[0016] The base 30 is provided with a pair of wheels 31, 32 and is a base body that is elongated in the left-right and up-down directions. Specifically, a driven wheel 31 and a driving wheel 32 are rotatably supported near the left and right ends of the base 30, respectively. For convenience of illustration, the axis CL31 of the driven wheel 31 and the axis CL32 of the driving wheel 32 are drawn to extend perpendicular to the plane of the page in FIG. 1, but they may also be tilted vertically. A wheel driving motor 32M is connected to the driving wheel 32, and the driving wheel 32 rotates at least in the direction of arrow DR1 (counterclockwise in FIG. 1) due to the operation of the wheel driving motor 32M.

[0017] The band saw blade 5 is placed between the driven wheel 31 and the drive wheel 32 by the user. The placed band saw blade 5 travels counterclockwise in FIG. 1 by operation of the wheel drive motor 32M (see arrow DR2). The band saw blade 5 has a body portion 51 and a cutting edge portion 52 formed on one edge of the body portion 51. With this configuration, the housing 3 moves up and down so as to move the band saw blade 5 towards and away from the workpiece W supported by the workpiece support portion 6. Furthermore, after the traveling band saw blade 5 comes into contact with the workpiece W, the housing 3 is further lowered, whereby the band saw blade 5 cuts the workpiece W.

[0018] The first guide unit 33 and the second guide unit 34 are arranged spaced apart in the left-right direction in accordance with the travel line that moves to the right below the band saw blade 5. The first guide unit 33 twists the cutting edge 52 of the band saw blade 5 downward, and the second guide unit 34 supports the band saw blade 5 and guides its travel so that it can be twisted back onto the drive wheel 32.

[0019] The first guide unit 33 and the second guide unit 34 have the same configuration, so the first guide unit 33 will be described in detail as a representative example with reference to FIGS. 2 and 3. FIG.

[0020] 2, the first guide unit 33 includes a first moving portion 331, a connecting rod 332, and a first guide portion 333. The first guide portion 333 has a first guide roller 334 that is supported by the lower end of the connecting rod 332 and rotates around an axis CL334 that extends in the front-rear direction.

[0021] The first moving section 331 has a first guide motor 33M, a holder 331a, and a first cam 33C, which is an eccentric cam. The holder 331a supports the first guide motor 33M so that its drive axis CL33 extends in the left-right direction, and rotatably supports the first cam 33C, which is connected to the drive shaft of the first guide motor 33M. The holder 331a also supports the elevation of a connecting rod 332 extending from below. The upper end of the connecting rod 332 is urged by a biasing member (not shown) to slide against the first cam 33C, which rotates due to the operation of the first guide motor 33M.

[0022] The band saw blade 5 has a cutting edge 52 at one edge on the lower side of the body 51, and a straight back portion 51a at the other edge on the upper side. The first guide roller 334 abuts against the back portion 51a so as to urge it downward.

[0023] The first cam 33C is an eccentric disk-shaped member. Therefore, when the first cam 33C rotates, the connecting rod 332 and the first guide roller 334 connected to the lower end thereof move up and down. This up and down movement is shown in Figures 3(a) and 3(b). For ease of understanding, Figures 3(a) and 3(b) are drawn so that the drive axis CL33 and the axis CL334 are parallel to each other.

[0024] As shown in Figure 3(a), when the rotation position of the first cam 33C is such that the bottom is the minor axis, the connecting rod 332 and the first guide roller 334 are at the uppermost position (arrow DR5), and the saw blade 5 is at the uppermost position of its stroke. Then, by operation of the first guide motor 33M, the first cam 33C rotates 180 degrees (arrow DR6), and as shown in Figure 3(b), when the first cam 33C reaches a position where the bottom is the major axis, the connecting rod 332 and the first guide roller 334 descend to the lowermost position (arrow DR7), and the saw blade 5 is at the lowermost position of its stroke. In this way, the band saw blade 5 moves up and down as the first cam 33C rotates.

[0025] The configuration and operation of the first guide unit 33 described above also apply to the second guide unit 34. That is, the first moving portion 331, connecting rod 332, and first guide portion 333 of the first guide unit 33 correspond to the second moving portion 341, connecting rod 342, and second guide portion 343, respectively, in the second guide unit 34. Furthermore, the first guide motor 33M, holder 331a, and first cam 33C correspond to the second guide motor 34M, holder 341a, and second cam 34C, respectively, in the second guide unit 34. The second guide portion 343 has a second guide roller 344 that is supported by the lower end of the connecting rod 342 and rotates about an axis CL344 extending in the front-rear direction. As a result, the first guide roller 334 and the second guide roller 344 are independently raised and lowered under the control of the control device 4.

[0026] In the above configuration, the operation of the lifting drive unit KD, first guide motor 33M, second guide motor 34M, wheel drive motor 32M, and clamper drive unit KK is controlled by a control device 4 as shown in FIG. 4. The control device 4 has a central processing unit 41, a memory unit 42, and a swing control unit 43. The memory unit 42 stores workpiece information such as the shape and material of the workpiece W to be cut by the band saw machine 91, as well as processing information such as cutting processing conditions for the workpiece W. Based on the workpiece information and processing information, the central processing unit 41 controls the amount of workpiece W fed by a work feed device (not shown), the traveling speed of the band saw blade 5, and the elevation and lowering of the housing 3. In particular, the swing control unit 43 controls the operation of the first guide motor 33M and second guide motor 34M in accordance with the cross-sectional shape of the workpiece W, etc., to swing the band saw blade 5. Next, the swinging operation of the band saw blade 5 will be described in detail with reference to FIGS. 5A to 10C.

[0027] FIG. 5A is a diagram showing the horizontal position PSH of the band saw blade 5. FIG. 5B is a diagram showing the right-side tilt position PSR of the band saw blade 5. FIG. 5C is a diagram showing the left-side tilt position PSL of the band saw blade 5. FIG. 6 is a diagram for explaining an outline of the procedure for cutting the workpiece WA. FIG. 7A is a first diagram for explaining the cutting step PA of the workpiece WA. FIG. 7B is a second diagram for explaining the cutting step PA. FIG. 7C is a third diagram for explaining the cutting step PA. FIG. 7D is a fourth diagram for explaining the cutting step PA. FIG. 7E is a fifth diagram for explaining the cutting step PA. FIG. 7F is a sixth diagram for explaining the cutting step PA. FIG. 7G is a seventh diagram for explaining the cutting step PA. FIG. 7H is an eighth diagram for explaining the cutting step PA. FIG. 7I is a ninth diagram for explaining the cutting step PA. FIG. 8A is a first diagram for explaining the cutting step PB of the workpiece WB. FIG. 8B is a second diagram for explaining the cutting step PB. FIG. 8C is a third diagram for explaining the cutting step PB. FIG. 8D is a fourth diagram for explaining the cutting step PB. FIG. 8E is a fifth diagram for explaining the cutting step PB. FIG. 8F is a sixth diagram for explaining the cutting step PB. FIG. 8G is a seventh diagram for explaining the cutting step PB. FIG. 8H is an eighth diagram for explaining the cutting step PB. FIG. 8I is a ninth diagram for explaining the cutting step PB. FIG. 9A is a timing diagram excluding the final stage of the cutting step PA. FIG. 9B is a timing diagram of the final stage of the cutting step PA. FIG. 10A is a diagram of the first stage of a flow showing the procedure of the cutting method of the embodiment. FIG. 10B is a diagram of the middle stage of a flow of the cutting procedure. FIG. 10C is a diagram of the final stage of a flow of the cutting procedure.

[0028] The portion of the band saw blade 5 between the first guide unit 33 and the second guide unit 34 is referred to as the cutting region 5R (see FIG. 1) of the band saw blade 5. The band saw machine 91 controls the rotational positions of the first cam 33C and the second cam 34C to freely change the posture of the cutting region 5R of the band saw blade 5 between a horizontal posture PSH, a right-inclined posture PSR, and a left-inclined posture PSL. Here, the right-inclined posture PSR is a posture inclined so that the right side is downward, and the left-inclined posture PSL is a posture inclined so that the left side is downward.

[0029] FIG. 5A schematically illustrates the horizontal posture PSH of the band saw blade 5. The swing control unit 43 operates the first guide motor 33M and the second guide motor 34M to control the first cam 33C and the second cam 34C so that their eccentric positions are the same. Specifically, as shown in FIG. 5A, the swing control unit 43 controls the first cam 33M and the second cam 34C so that their major axis positions DL are positioned on a horizontal line perpendicular to the drive axes CL33 and CL34. More specifically, the major axis position DL of the first cam 33C is located to the left of the drive axis CL33, and the major axis position DL of the second cam 34C is located to the right of the drive axis CL34. This control causes the height positions of the connecting rods 332 and 342 to be the same at the center of the lifting stroke, and the band saw blade 5 in the cutting region 5R is in a horizontal posture. To stably maintain the horizontal posture of the band saw blade 5, the band saw blade 5 in the horizontal posture urges the first guide roller 334 and the second guide roller 344 upward. 1, the position at which the cutting region 5R of the band saw blade 5 is guided by the first guide roller 334 and the second guide roller 344 is set below a reference running line SLN that horizontally connects the unwinding position from the driven wheel 31 and the winding position by the drive wheel 32. Furthermore, a biasing roller (not shown) that biases the body 51 of the band saw blade 5 toward the first guide roller 334 and the second guide roller 344 may be arranged in each of the first guide unit 33 and the second guide unit 34.

[0030] 5B is a schematic diagram showing the state of the band saw blade 5 in the right-tilt position PSR. The swing control unit 43 operates the first guide motor 33M and the second guide motor 34M to rotate the first cam 33C and the second cam 34C clockwise by 90° from the horizontal position PSH (see arrows DR8 and DR9), so that the long axis position DL of the first cam 33C is at the top and the long axis position DL of the second cam 34C is at the bottom. As a result, the connecting rod 332 is at the top of its lifting stroke, the connecting rod 342 is at the bottom, and the band saw blade 5 in the cutting region 5R is in the right-tilt position PSR with its right side lowered.

[0031] 5C is a schematic diagram showing the state of the band saw blade 5 in the left tilt position PSL. The swing control unit 43 operates the first guide motor 33M and the second guide motor 34M to rotate the first cam 33C and the second cam 34C clockwise by 180° from the positions of the right tilt position PSR (see arrows DR10 and DR11), so that the long diameter position DL of the first cam 33C is at its lowest and the long diameter position DL of the second cam 34C is at its highest. As a result, the connecting rod 332 is at its lowest position in its lifting stroke, and the connecting rod 342 is at its highest position, so that the band saw blade 5 in the cutting region 5R is in the left tilt position PSL with the left side lowered.

[0032] The angle of the back 51a of the band saw blade 5 with respect to the horizontal in the right inclined position PSR and the left inclined position PSL is defined as the inclination angle θ. The inclination angle θ is the angle at which the inclination of the band saw blade 5 is maximum, and is the same in the right inclined position PSR and the left inclined position PSL.

[0033] An example of the procedure for cutting the workpiece W using the above-mentioned swinging motion will now be described. Fig. 6 shows a schematic outline of the cutting procedure when the workpiece W is a solid rectangular prism workpiece WA. First, a set maximum cutting length Lb is set to exceed D / 2, where D is the width in the left-right direction when the workpiece WA is placed on the support table 61. In this example, the set maximum cutting length Lb is set to Lb = (2 / 3)D.

[0034] In Figure 6, the solid lines indicate the tip position of the cutting portion 52 of the band saw blade 5 (hereinafter also referred to as the cutting line). In the parenthesized symbols attached to the right end of each solid line, the left tilt position PSL is L and the right tilt position PSR is R. The start position of cutting is s and the end position of cutting is e. The numbers indicate the number of cuts. That is, (R2e) indicates the end position of the second cut in the right tilt position.

[0035] In this example, the cutting length is conveniently defined as the horizontal distance of the cutting line, even if the cutting line is inclined. The inclination angle θ of the band saw blade 5 (see Figures 5A and 5B) is set to 1° or less. Therefore, the difference between the actual cutting line length and its horizontal distance is sufficiently small that no practical problems occur.

[0036] First, the first cut is performed by lowering the housing 3 (not shown) from a start position L1s to an end position L1e with the band saw blade 5 in a left-inclined position L. The start occurs when the cutting line reaches the upper left edge CN1 of the workpiece WA, and the end occurs when the cutting length La, which increases with the cutting depth in the inclined position, reaches the set maximum cutting length Lb. Specifically, this is the point when the tip of the cutting portion 52 reaches a position P1, a distance (2 / 3)D to the right from the left edge on the top surface WAa of the workpiece WA.

[0037] The second cut is performed from a start position R1s to an end position R1e with the band saw blade 5 in a right-inclined posture R. The start occurs when the cutting line reaches the upper right edge CN2 of the workpiece WA, and the end occurs when the tip of the cutting edge 52 reaches a position P2, a distance (2 / 3)D to the left from the right edge of the workpiece WA.

[0038] The third cut is the second cut in the left tilt posture L, and is performed from start position L2s to end position L2e. It starts when the tip of the cutting portion 52 reaches position P2 on the previous cutting surface, and ends when the tip of the cutting portion 52 reaches position P3, a distance (2 / 3)D to the right from the left edge of the workpiece WA on the previous cutting surface. The fourth and fifth cuts are performed in the same way.

[0039] The band saw 91 is controlled by the control device 4 to change its position between the left tilt position L and the right tilt position R by raising the housing 3. Hereinafter, detailed procedures for the cutting operation accompanied by swinging, including the operation of raising the housing 3, will be described with reference to FIGS. 7A to 10C.

[0040] FIG. 1 is a front view showing the configuration of a band saw machine 91 according to one embodiment of the present invention. FIG. 2 is a schematic diagram illustrating the structure of a first guide unit 33 in the band saw machine 91. FIG. 3 is a diagram illustrating the operation of the first guide unit 33, with FIG. 3(a) showing the first guide unit 33 in an elevated position and FIG. 3(b) showing the first guide unit 33 in a lowered position. FIG. 4 is a block diagram of the band saw machine 91. FIG. 5A is a diagram illustrating the horizontal position PSH of the band saw blade 5. FIG. 5B is a diagram illustrating the right-tilted position PSR of the band saw blade 5. FIG. 5C is a diagram illustrating the left-tilted position PSL of the band saw blade 5. FIG. 6 is a diagram illustrating an outline of the cutting procedure for the workpiece WA. FIG. 7A is a first diagram illustrating the cutting step PA of the workpiece WA. FIG. 7B is a second diagram illustrating the cutting step PA. FIG. 7C is a third diagram illustrating the cutting step PA. FIG. 7D is a fourth diagram illustrating the cutting step PA. FIG. 7E is a fifth diagram illustrating the cutting step PA. FIG. 7F is a sixth diagram illustrating the cutting step PA. FIG. 7G is a seventh diagram for explaining the cutting step PA. FIG. 7H is an eighth diagram for explaining the cutting step PA. FIG. 7I is a ninth diagram for explaining the cutting step PA. FIG. 8A is a first diagram for explaining the cutting step PB of the workpiece WB. FIG. 8B is a second diagram for explaining the cutting step PB. FIG. 8C is a third diagram for explaining the cutting step PB. FIG. 8D is a fourth diagram for explaining the cutting step PB. FIG. 8E is a fifth diagram for explaining the cutting step PB. FIG. 8F is a sixth diagram for explaining the cutting step PB. FIG. 8G is a seventh diagram for explaining the cutting step PB. FIG. 8H is an eighth diagram for explaining the cutting step PB. FIG. 8I is a ninth diagram for explaining the cutting step PB. FIG. 9A is a timing diagram excluding the final stage of the cutting step PA. FIG. 9B is a timing diagram of the final stage of the cutting step PA. FIG. 10A is a diagram of the first stage of a flow showing the procedure of the cutting method of the embodiment. Fig. 10B is a diagram of the middle stage in the flow of the cutting procedure. Fig. 10C is a diagram of the final stage in the flow of the cutting procedure. The lifting and lowering of the housing 3 and the change in the tilt position of the band saw blade 5, which will be described below, are controlled by the control device 4. The traveling direction of the band saw blade 5 in Figs. 7A to 10I is from left to right, as is clear from the arrow DR2 in Fig. 1.

[0041] First, the cutting process PA when the workpiece W is a solid prismatic workpiece WA will be described with reference to Figures 7A to 7I and flow charts 10A to 10C. In Figures 7A to 7I, the inclination of the band saw blade 5 is exaggerated. In addition, (S1) in the description is the code for the step in Figures 10A to 10C.

[0042] The control device 4 raises the housing 3, moves the band saw blade 5 to an initial position above the workpiece WA (S1), and drives the wheel drive motor 32M to start the band saw blade 5 traveling (S2). The control device 4 determines the shape of the workpiece W to be machined next based on the workpiece information stored in the memory unit 42 (S3). In this case, since the workpiece W is prismatic, the band saw blade 5 is set to a first tilted position. It is set in advance which side is to be down as the first tilted position. Here, the left tilted position L is set as shown in FIG. 7A (S4).

[0043] Next, the housing 3 is lowered (arrow DR12) (S6). When the cutting portion 52 reaches the upper left end CN1 of the workpiece WA, cutting begins (S7).

[0044] The swing control unit 43 constantly monitors the height position of the cutting portion 52 in the cutting region 5R of the band saw blade 5 while the housing 3 is descending. The height position of the cutting portion 52 is determined based on the cumulative ascending and descending distances of the housing 3. Furthermore, it determines whether the cutting length La has reached a preset maximum cutting length Lb (S8) based on the descending distance of the housing 3 from the start of cutting, which is the amount of cut into the workpiece WA, and the inclination angle θ of the band saw blade 5. If it is determined that the cutting length La has not reached the preset maximum cutting length Lb (No) in (S8), cutting and determination continue, and if it is determined that the cutting length La has reached the preset maximum cutting length Lb (Yes), the descent of the housing 3 is stopped (FIG. 7B) (S9).

[0045] After stopping the descent in (S9), the swing control unit 43 determines whether the width D of the remaining cutting portion of the workpiece WA has become equal to or less than a predetermined remaining width Dp (S10). The predetermined remaining width Dp is set to a value less than the set maximum cutting length Lb.

[0046] If the determination in (S10) is No, the swing control unit 43 raises the housing 3 (FIG. 7C: arrow DR13) (S11). The raised position is a position where the band saw blade 5 does not come into contact with the workpiece WA even when the band saw blade 5 is changed in position between the left tilt position PSL and the right tilt position PSR. This raised position is preferably a position where the tip of the cutting portion 52 of the band saw blade 5 is as close as possible to the upper right end CN2 of the workpiece W so that the next cutting can be started immediately after the position change.

[0047] After raising the housing 3 in (S11), the swing control unit 43 changes the inclination of the band saw blade 5 to a second inclined position (S131), which is the opposite of the first inclined position, if the inclination of the band saw blade 5 is the first inclined position. If the inclination of the band saw blade 5 is the second inclined position or the horizontal position, the swing control unit 43 changes the inclination of the band saw blade 5 to the first inclined position (S132). Since this is the first determination, the right inclined position PSR of the second inclined position is set (FIG. 7D: arrow DR15). Then, the process returns to (S6), and the housing 3 is lowered (FIG. 7D: arrow DR16). From here on, FIGS. 7E to 7G are a repetition of (S7) to (S131) ​​or (S132) in FIG. 10B.

[0048] That is, as shown in Fig. 7E, the housing 3 descends (arrow DR17), and when it is determined that the cutting length La has reached the set maximum cutting length Lb, the housing 3 changes from descending to ascending (Fig. 7F: arrow DR18) and assumes the left tilt posture PSL (DR19).Then, the housing 3 is again descended (Fig. 7G: arrow DR20), and cutting is resumed (S7).

[0049] If it is determined in (S10) during the repetition of (S7) to (S131) ​​or (S132) that the remaining width of the workpiece WA is equal to or less than the predetermined remaining width Dp (FIG. 7H), the process proceeds to (F1) in FIG. 10C.

[0050] In (F1), the swing control unit 43 raises the housing 3 (arrow DR21 in FIG. 7I) (S14) and sets the band saw blade 5 in a horizontal position (arrow DR22) (S15). Then, the housing 3 is lowered again (arrow DR23) (S16), and the remaining workpiece WA is cut by the band saw blade 5 in the horizontal position (S17) (S18).

[0051] The rectangular workpiece WA is cut using the above procedure.

[0052] Next, the cutting step PB when the workpiece W is a solid cylindrical workpiece WB will be described with reference to Figures 8A to 8I and flow charts 10A to 10C. In Figures 8A to 8I, the inclination of the band saw blade 5 is exaggerated. In addition, (S1) in the description is the code for the step in Figures 10A to 10C.

[0053] The control device 4 raises the housing 3, moves the band saw blade 5 to an initial position above the workpiece WB (FIG. 8A) (S1), and drives the wheel drive motor 32M to start the band saw blade 5 traveling (S2). The control device 4 determines the shape of the workpiece W to be machined next based on the workpiece information stored in the memory unit 42 (S3). In this case, the workpiece W is cylindrical, so the band saw blade 5 is placed in a horizontal position (S5).

[0054] The control device 4 lowers the housing 3 (S6), and cutting begins (S7). While the housing 3 is lowering, the swing control unit 43 constantly monitors the height position of the cutting edge 52 in the cutting region 5R of the horizontally positioned band saw blade 5. The cutting length La is determined from the shape of the workpiece WB and the height position of the cutting edge 52, and it is determined whether the cutting length La has reached a preset maximum cutting length Lb (FIG. 8B) (S8). For a cylindrical workpiece WB, the preset maximum cutting length Lb is set based on the outer diameter DB of the workpiece WB. For example, Lb = (2 / 3)DB.

[0055] If the swing control unit 43 determines that the housing 3 has been reached (Yes) in (S8), it stops the descent of the housing 3 (S9) and proceeds to the determination in (S10). Here, the determination in (S10) is No, and the swing control unit 43 raises the housing 3 (arrow DR32 in FIG. 8C) (S11).

[0056] The swing control unit 43 (S12) changes the band saw blade 5 from the horizontal position up to this point to the first tilted position (arrow DR33 in FIG. 8D) (S132) and lowers the housing 3 (arrow DR34) (S6). In FIG. 8D, the first tilted position is shown as the right tilted position PSR. Below, FIGS. 8E to 8G are a repetition of (S7) to (S131) ​​or (S132) in FIG. 10B.

[0057] In Fig. 8E, the housing 3 descends to perform cutting (arrow DR35), and when the cutting length La reaches the set maximum cutting length Lb (S8-Yes), the housing 3 changes from descending to ascending (arrow DR36 in Fig. 8F). Then, when the band saw blade 5 rises to a position where it does not contact the workpiece WB, the housing 3 is repositioned to the left-side tilt position of the second tilt position (DR37) (S12) (S131). The housing 3 is then lowered again (arrow DR375 in Fig. 8G) (S6), and cutting resumes (S7).

[0058] If it is determined in (S10) during the repetition of (S7) to (S131) ​​or (S132) that the remaining width of the workpiece WB is equal to or less than the predetermined remaining width Dp (FIG. 8H), the process proceeds to (F1) in FIG. 10C.

[0059] In (F1), the swing control unit 43 raises the housing 3 (arrow DR39 in FIG. 8I) (S14) and sets the band saw blade 5 in a horizontal position (arrow DR40) (S15). Then, the housing 3 is lowered again (arrow DR41) (S16), and the remaining workpiece WB is cut by the band saw blade 5 in the horizontal position (S17) (S18).

[0060] The cylindrical workpiece WB is cut using the above procedure.

[0061] 9A and 9B are timing diagrams showing the transition of the height position H of the housing 3 and the operation of the first cam 33C and the second cam 34C during the cutting process PA. The rotational positions of the first cam 33C and the second cam 34C are indicated by three symbols: 1, C, and 2. 1 is the rotational position where the major axis position DL is at the lowest, C is horizontal, and 2 is the rotational position where the major axis position DL is at the highest. Therefore, during the period from time t2 to time t3 in FIG. 9A, the first cam 33C is at rotational position 1, the second cam 34C is at rotational position 2, and the band saw blade 5 is in the left tilt position PSL shown in FIG. 5C. Similarly, during the period from time t4 to time t5, the band saw blade 5 is in the right tilt position PSR.

[0062] 9A, the height position H of the housing 3 is shown to be raised during a period in which the position of the band saw blade 5 is changed by changing the rotational positions of the first cam 33C and the second cam 34C while the height H is being lowered over time. Time t1 corresponds to (S4), and time t2 corresponds to the start of cutting. Time t3 corresponds to (S11), and time t4 corresponds to the second (S6).

[0063] Figure 9B corresponds to (S14) to (S18) in Figure 10C. Time tk1 corresponds to (S14), time tk2 corresponds to (S16), and time tk3 corresponds to (S18). The periods between times t1 and t2, between times t3 and t4, and between times t13 and t14 in Figure 9A, and the period between times tk1 and tk2 in Figure 9B are periods for changing the posture of the band saw blade 5. It is preferable to control the lifting and lowering operation of the housing 3 and the posture changing operation of the band saw blade 5 so that these posture changing periods are as short as possible, as this reduces the cutting time of the workpiece W.

[0064] As described above in detail, the band saw machine 91 according to one embodiment of the present invention can perform cutting while oscillating the band saw blade 5 that cuts the workpiece W between a left-inclined position and a right-inclined position, thereby keeping the cutting length below a preset maximum cutting length Lb. The selective position change of the band saw blade 5 between the left-inclined position and the right-inclined position is performed by raising the housing 3 to a position where the workpiece W and the band saw blade 5 are not in contact with each other. Therefore, since cutting resistance does not increase during position change, there is no need to construct the band saw machine excessively sturdy. Furthermore, the band saw blade 5 has a long life, and the occurrence of cutting bending is suppressed.

[0065] One aspect of the present invention is not limited to the above-described configuration and procedure, and modifications may be made without departing from the spirit of the present invention.

[0066] The change of the inclined posture of the band saw blade 5 is not limited to that realized by the rotation of the first cam 33C and the second cam 34C as described above, and a known structure may be applied.

[0067] Although the band saw 91 has been described as a horizontal type, it is not limited to a horizontal type and may be a vertical type. In the vertical type, the up and down direction corresponds to the direction of movement of the housing, and the downward direction corresponds to the cutting direction.

[0068] As an example in which the first and second inclined postures of the band saw blade 5 have different inclination angles θ, the inclination directions are opposite and the absolute values ​​of the inclination angles θ are the same, but as long as the inclination directions are opposite, the absolute values ​​of the inclination angles θ may be different.

[0069] As described above in detail, a first aspect of one or more embodiments of the present invention includes a work support portion 6 that supports a long workpiece W, a housing 3 having a pair of wheels 31, 32 on which a band saw blade 5 is hung and which causes the hung band saw blade 5 to travel in a circular motion, and which moves the band saw blade 5 so as to move the band saw blade 5 toward and away from the workpiece W supported by the work support portion 6, and a control device 4 that controls the movement of the housing 3, and the housing 3 includes a first guide roller 334 and a second guide roller 344 that guide the back portion 51a of the band saw blade 5 at positions spaced apart in the traveling direction across a position where the workpiece W is cut, and The band saw machine 91 has a first moving unit 331 and a second moving unit 341 that independently move the roller 334 and the second guide roller 344 toward and away from the workpiece W, and selectively change the position of the band saw blade 5 between the first guide roller 334 and the second guide roller 344 between a first inclined position and a second inclined position that is inclined at an angle different from the first inclined position, and the control device 4 changes the position of the band saw blade 5 between the first inclined position and the second inclined position to cut the workpiece W in each position, and changes the position of the band saw blade 5 by moving the housing 3 to a position where the band saw blade 5 is away from the workpiece W.

[0070] According to this first aspect, the band saw blade 5 does not come into contact with the workpiece W when changing its position, so the cutting length does not increase and there is no cutting resistance, thereby extending the life of the band saw blade 5, further suppressing the occurrence of the cutting bending phenomenon, and simplifying the structure of the band saw machine 91.

[0071] In the first aspect, the first moving portion and the second moving portion may move the first guide roller 334 and the second guide roller 344 based on the rotational movement of the eccentric cams 33C and 34C.

[0072] This allows the first moving section and the second moving section to be formed compactly.

[0073] In the first embodiment, the control device 4 may be configured to change the position when the cutting length La of the band saw blade 5 relative to the workpiece W reaches a preset maximum cutting length Lb.

[0074] As a result, the cutting length La does not become excessively long and an excessive load is not applied to the band saw blade 5, so that the life of the band saw blade 5 is not unintentionally shortened.

[0075] A second aspect of one or more embodiments of the present invention is a method for cutting a workpiece W using a band saw blade, in which, when cutting a long workpiece W with a band saw blade 5, the band saw blade 5 is changed between a first inclined position and a second inclined position that is inclined at an angle different from the first inclined position, and cutting is performed in each position, and the position change is performed by moving the band saw blade 5 to a position away from the workpiece W.

[0076] According to this second aspect, the band saw blade 5 does not come into contact with the workpiece W when changing its position, so the cutting length does not increase and there is no cutting resistance, thereby extending the life of the band saw blade 5, further suppressing the occurrence of the cutting bending phenomenon, and simplifying the structure of the band saw machine 91.

[0077] In the second embodiment, the posture change may be performed when the cutting length La of the band saw blade 5 relative to the workpiece W reaches a preset maximum cutting length Lb.

[0078] As a result, the cutting length La does not become excessively long and an excessive load is not applied to the band saw blade 5, so that the life of the band saw blade 5 is not unintentionally shortened. [Explanation of symbols]

[0079] 1 base 2 Housing support 2a opening 3. Housing 30 base 31 Driven wheel 32 drive wheel 32M Wheel Drive Motor 33 First guide unit 331 First moving part (first cam part) 331a Holder 332 Connecting rod 333 First guide section 334 First guide roller 33C First Cam 33M First guide motor 34 Second guide unit 341 Second moving part (second cam part) 341a Holder 342 Connecting rod 343 Second guide section 344 Second guide roller 34C 2nd cam 34M Second guide motor 4. Control device 41 Central Processing Unit 42 Storage section 43 Swing control section 5 Bandsaw Blades 51 Torso 51a back 52 Blade part 5R cutting area 6 Work support part 61 Support stand 62,63 Clamper 91 Band saw machine CL31,CL32,CL334,CL344 Axis CL33,CL34 drive axis CN1 Upper left corner CN2 Upper right corner D width DB outer diameter DL long axis position Dp Remaining predetermined width FL installation surface KD lifting drive unit KK clamper drive unit La cutting length Lb setting maximum cutting length P1,P2,P3 position PA,PB cutting process PSH horizontal posture PSR,R Right leaning posture PSL,L Left leaning posture SLN Reference Running Line W,WA,WB Work WAa Top θ Tilt angle

Claims

1. a work support portion that supports a long work; a housing having a pair of wheels on which a band saw blade is stretched and which circulates the stretched band saw blade, the housing moving to move the band saw blade toward and away from the work supported by the work support portion; a control device for controlling movement of the housing; Equipped with The housing includes: a first guide roller and a second guide roller that guide the back of the band saw blade at positions spaced apart in the traveling direction across a position where the workpiece is cut; a first moving unit and a second moving unit that independently move the first guide roller and the second guide roller so as to approach and move away from the workpiece, thereby selectively changing the position of the band saw blade between the first guide roller and the second guide roller between a first inclined position and a second inclined position that is inclined at an angle different from the first inclined position, The control device The band saw blade is changed in position between the first inclined position and the second inclined position to cut the workpiece at each position, and the change in position of the band saw blade is performed by moving the housing to a position where the band saw blade is separated from the workpiece. Band saw machine.

2. The band saw according to claim 1 , wherein the first moving portion and the second moving portion move the first guide roller and the second guide roller based on the rotation of an eccentric cam.

3. 3. The band saw machine according to claim 1, wherein the control device changes the position when the cutting length of the band saw blade relative to the workpiece reaches a preset maximum cutting length.

4. When cutting a long workpiece with a band saw blade, The band saw blade is switched between a first inclined position and a second inclined position inclined at an angle different from the first inclined position, and cutting is performed in each position. A method for cutting a workpiece using a band saw blade, wherein the posture change is performed by moving the band saw blade to a position away from the workpiece.

5. The posture change is 5. A method for cutting a workpiece with a band saw blade according to claim 4, wherein the method is carried out after a housing provided on a band saw machine and having a pair of wheels across which the band saw blade is stretched is moved to a position where the band saw blade is separated from the workpiece.

6. 6. The method for cutting a workpiece with a band saw blade according to claim 4, wherein the posture change is carried out when the cutting length of the band saw blade relative to the workpiece reaches a preset maximum cutting length.

Images