A band saw blade braking device and braking method

Abstract

This invention provides a band saw blade braking device and method, belonging to the technical field of metal cutting equipment, including a lifting frame, a tray, pulleys, and a clamping arm. Each pulley has a tensioning wheel assembly at both the saw blade inlet and outlet ends. Each tensioning wheel assembly includes two positioning rollers and a movable roller located between the two positioning rollers, and works in conjunction with a first cylinder, a tension sensor, and a brake block driven by an electromagnet and a spring. When the saw blade breaks, the first cylinder quickly extends, causing the saw blade to loosen and disengage from the pulley, thereby instantly cutting off the driving force of the drive wheel on the saw blade and preventing inertial drive from exacerbating the swinging motion. Simultaneously, after the electromagnet is de-energized, the spring pushes the brake block to clamp the saw blade onto the movable roller, effectively suppressing the release of elastic potential energy and swinging motion of the bent section of the saw blade.

Description

Technical Field

[0001] This invention belongs to the technical field of metal cutting equipment, specifically referring to a band saw blade braking device and braking method. Background Technology

[0002] A band saw is a high-efficiency metal processing device that uses a circular saw band as the cutting tool. It achieves precise cutting of materials such as steel and alloys through the continuous unidirectional movement of the saw band. Its core advantages lie in its narrow kerf (low material loss), high cutting accuracy (excellent straightness and parallelism), and lower energy consumption compared to traditional circular saws. Models ranging from manual control to fully automatic CNC feeding are available, and it is widely used in machinery manufacturing and mold processing.

[0003] Because the saw blade is bent at the drive and driven wheels, the saw blade stores force at these points. If the saw blade breaks, the elasticity at the bent point is released, causing the saw blade to swing. Currently, by installing protective covers on the outside of the drive and driven wheels of the band saw, the bent saw blade is enclosed inside the protective covers. When the saw blade breaks, the swing range of the saw blade is limited, preventing the saw blade from injuring the operator.

[0004] However, for the sake of convenient saw blade replacement and maintenance, a large gap is left between the protective cover plate and the drive and driven wheels. The protective cover plate alone cannot completely suppress the release of the saw blade's elasticity. When the saw blade breaks, the saw blade located outside the protective cover plate will still swing. Even if the machine is stopped in time, due to inertia, the drive wheel will still drag the saw blade to continue rotating for a certain period of time, thereby applying driving force to the saw blade and further aggravating the swinging of the saw blade, which poses a significant safety hazard. Summary of the Invention

[0005] In view of the above situation and to overcome the defects of the prior art, the purpose of the present invention is to provide a band saw blade braking device and braking method to at least partially solve the problems mentioned in the background art.

[0006] The technical solution adopted by this invention is as follows: This invention proposes a band saw blade braking device, comprising: The lifting frame has trays installed on both sides, and each tray is rotatably connected to a pulley. Two clamping arms are mounted on the lifting frame; Each of the pulleys is provided with a tensioning wheel set at both the saw blade inlet and outlet ends. Each tensioning wheel set includes two positioning rollers and a movable roller located between the two positioning rollers. The saw blade alternately passes around the positioning rollers and the movable roller. A first cylinder is fixed between the saw blade inlet and outlet of each of the pulleys. The first cylinder includes two telescopic ends, each of which is connected to a mounting bracket. The mounting bracket is connected to the movable roller on the corresponding side. The first cylinder is used to drive the movable roller to move in order to adjust the tension of the saw blade. A brake block is provided on the side of the movable roller that contacts the saw blade. A spring drive unit is installed on the mounting frame. The spring drive unit is configured to push the brake block toward the movable roller so that the saw blade is clamped and braked.

[0007] Furthermore, a tension sensor is connected between the two telescopic ends of the first cylinder and the mounting bracket to detect the tension of the saw blade in real time.

[0008] Furthermore, the elastic drive unit includes a fixed frame, springs and an electromagnet. The fixed frame is fixed on the mounting frame, and multiple springs are connected between the brake block and the fixed frame. The electromagnet is fixed on the fixed frame, and the brake block can be magnetically attracted to the electromagnet. When the electromagnet is energized, the brake block is attracted to the electromagnet, and the spring is in a compressed and stored state. When the electromagnet is de-energized, the spring is released and pushes the brake block to move toward the movable roller, so that the saw blade is clamped and braked.

[0009] Furthermore, the elastic drive unit also includes a guide rod, which is arranged parallel to the moving direction of the brake block. One end of the guide rod is fixed to the brake block, and the other end of the guide rod passes through the fixing frame and slides in cooperation with the fixing frame.

[0010] Furthermore, the brake block has a brake surface on one side facing the movable roller. The brake surface is an arc surface that matches the outer circumferential surface of the movable roller to increase the braking contact area.

[0011] Furthermore, the braking surface is provided with anti-slip grooves to increase friction.

[0012] Furthermore, two limiting rollers are rotatably connected to one side of the bottom end of the clamping arm, and the saw blade passes between the two limiting rollers.

[0013] Furthermore, the bottom end of the clamping arm is provided with two brake plates, and the two brake plates are symmetrically distributed on both sides of the saw blade movement direction. The bottom end of the clamping arm is also fixed with a second cylinder, which includes two telescopic ends and is respectively connected to the two brake plates. The second cylinder is configured to drive the two brake plates to move closer to or further away from each other.

[0014] Furthermore, the bottom ends of the brake plates, which are close to each other, are each fixed with a friction surface for increasing friction.

[0015] A method for braking a band saw blade in case of breakage, using the aforementioned band saw blade braking device, includes the following steps: S1. When the saw blade is cutting normally, the first cylinder is in the retracted state, and the movable roller pulls the saw blade in the tensioned state; the electromagnet is energized, the brake block is attracted to the electromagnet, and the spring is compressed and stored; the second cylinder is in the extended state, so that the two brake plates move away from each other. S2. The tension sensor detects the tension on the movable roller due to the tension of the saw blade in real time. If the tension value detected by the tension sensor remains above the set normal threshold, it is determined that the saw blade has not broken. If the detected tension value drops rapidly and falls below the set breakage threshold, it is determined that the saw blade has broken. S3. When the saw blade breaks, the two telescopic ends of the first cylinder extend quickly to further reduce the tension of the saw blade. Under the action of the elastic restoring force at the bending point of the saw blade, the saw blade is disengaged from the pulley, thus preventing the pulley from continuing to apply driving force to the saw blade. S4. At the same time, the electromagnet loses its magnetic attraction when it is de-energized, the spring is released, the brake block is pushed towards the movable roller, and the saw blade is clamped and braked under the elastic pressure of the spring. At this time, the saw blade at both the pulley inlet and outlet ends is clamped, and the elastic force of the bent saw blade at the pulley cannot be released further. S5. At the same time, the two telescopic ends of the second cylinder retract, causing the two brake plates to move closer to each other and clamp the saw blade for braking.

[0016] Beneficial effects: 1. By setting tensioning wheel sets consisting of two positioning rollers and one movable roller at the saw blade inlet and outlet ends of the pulley, and cooperating with a first cylinder, a tension sensor, and a brake block driven by an electromagnet and a spring, when the saw blade breaks, the first cylinder quickly extends to loosen the saw blade and disengage it from the pulley, thereby instantly cutting off the driving force of the drive wheel on the saw blade and avoiding intensified swinging due to inertial drive; at the same time, after the electromagnet is de-energized, the spring pushes the brake block to clamp the saw blade on the movable roller, effectively suppressing the release of elastic potential energy and swinging of the bent section of the saw blade.

[0017] 2. By setting two symmetrical braking clamps driven by a second cylinder at the bottom of the clamping arm, they can work together with the brake block to clamp and brake the cutting section of the saw blade when the saw blade breaks, preventing the saw blade from swinging out of a wide range due to elastic vibration. At the same time, they form a multi-point clamping with the brake at the movable roller 3, further improving braking stability. Attached Figure Description

[0018] Figure 1This is a schematic diagram of the structure of a band saw blade braking device according to an embodiment of the present invention; Figure 2 This is a top view of the tray in a band saw blade braking device according to an embodiment of the present invention; Figure 3 This is a schematic diagram showing the positional distribution of the tensioning wheel group in a band saw blade braking device according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the extension and retraction end connection of the first cylinder in a band saw blade braking device according to an embodiment of the present invention; Figure 5 This is a schematic diagram showing the connection between the elastic drive unit and the brake block in a band saw blade braking device according to an embodiment of the present invention; Figure 6 This is a schematic diagram showing the installation position of the brake clamp in a band saw blade braking device according to an embodiment of the present invention; Figure 7 This is a schematic diagram showing the disassembly of the brake clamping plate and the clamping arm in a band saw blade braking device according to an embodiment of the present invention.

[0019] Among them, 1. Lifting frame; 11. Pallet; 12. Pulley; 13. Clamping arm; 14. Limiting roller; 2. Positioning roller; 3. Movable roller; 4. First cylinder; 41. Mounting frame; 5. Tension sensor; 6. Brake block; 601. Braking surface; 61. Fixing frame; 62. Spring; 63. Electromagnet; 64. Guide rod; 7. Brake clamp; 701. Friction surface; 8. Second cylinder.

[0020] The accompanying drawings are provided to further understand the embodiments and form part of the specification. They are used together with the embodiments for explanation and do not constitute a limitation on the embodiments. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection.

[0022] In the description of the embodiments, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the embodiments and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments.

[0023] Combination Figures 1-7 As shown, an embodiment of the present invention provides a band saw blade braking device, including a lifting frame 1, a tray 11, a pulley 12, a clamping arm 13, and a tensioning wheel assembly.

[0024] A band saw typically includes a bed, a column, a lifting frame 1, two trays 11, two pulleys 12, and two clamping arms 13. The lifting frame 1 is slidably mounted on the column of the band saw and can move up and down under the drive of a drive mechanism (such as a hydraulic cylinder or lead screw mechanism, not shown in the figure) to achieve the feeding and cutting of the saw blade.

[0025] Two trays 11 are fixedly installed on the left and right sides of the lifting frame 1, respectively. Each tray 11 is rotatably connected to a pulley 12 via a bearing. Normally, one pulley 12 is the driving pulley, which is connected to the main motor of the band saw, while the other pulley 12 is the driven pulley, which rotates with the saw blade. During normal operation of the saw blade, the annular saw blade is tautly fitted onto the two pulleys 12. The main motor drives the driving pulley to rotate, thereby driving the saw blade to move at high speed and cut the workpiece.

[0026] Two clamping arms 13 are mounted on the lifting frame 1. Specifically, the upper end of the clamping arm 13 is fixedly connected to the lifting frame 1, and the lower end of the clamping arm 13 extends downward to the saw blade movement path. The lower end of the clamping arm 13 is provided with a clamping groove, and a corresponding positioning roller is installed in the clamping groove. The saw blade passes through the clamping groove and is limited by the positioning roller, which can increase the stability of the saw blade during cutting and limit the movement trajectory of the saw blade.

[0027] Combination Figure 2 and Figure 3 As shown, each pulley 12 has a tensioning wheel assembly at both the saw blade inlet and outlet ends. The "saw blade inlet end" refers to the side where the saw blade enters the pulley 12 and begins to bend, while the "saw blade outlet end" refers to the side where the saw blade leaves the pulley 12 and ends its bending. Because the saw blade needs to bend approximately 180 degrees at the pulley 12 to wrap around it, it is in a bent state near both the inlet and outlet ends, accumulating significant elastic potential energy.

[0028] Each tensioning wheel assembly includes two positioning rollers 2 and one movable roller 3, with the movable roller 3 located between the two positioning rollers 2. The positioning rollers 2 are fixedly mounted on the tray 11. The saw blade travels around the tensioning wheel assembly as follows: after coming from the upstream direction, the saw blade first passes around the outside of the first positioning roller 2, then reverses direction and passes around the inside of the movable roller 3, and finally passes around the outside of the second positioning roller 2, forming an "S" or "Z" shaped path. The advantage of this path is that when the movable roller 3 moves, a large change in saw blade length can be achieved with a small displacement, thereby efficiently adjusting the tension of the saw blade.

[0029] Combination Figure 3, Figure 4 and Figure 5 As shown, a first cylinder 4 is fixed between the saw blade inlet and outlet of each pulley 12.

[0030] Specifically, the cylinder body of the first cylinder 4 is fixedly mounted on the tray 11 by a bracket and is located next to the pulley 12. The first cylinder 4 is a double-output cylinder, that is, both ends of its piston rod extend outward to form two telescopic ends. Each telescopic end is fixedly connected to a mounting bracket 41, and the mounting bracket 41 is connected to the rotating shaft of the movable roller 3 on the corresponding side (inlet end or outlet end).

[0031] It should be noted that the stroke direction of the first cylinder 4 is consistent with the movement direction of the movable roller 3, and is usually arranged perpendicular to the saw blade movement direction or along the tension direction of the saw blade. The function of the first cylinder 4 is to drive the movable roller 3 to move, thereby adjusting the tension of the saw blade.

[0032] During normal cutting, the telescopic end of the first cylinder 4 is in the retracted state, and the movable roller 3 pushes the saw blade outward to maintain appropriate tension. When the saw blade needs to be replaced or maintained, the telescopic end of the first cylinder 4 extends, the movable roller 3 moves inward, the saw blade loosens, and it is easy to disassemble.

[0033] Furthermore, tension sensors 5 are connected between the two telescopic ends of the first cylinder 4 and the mounting bracket 41. One end of the tension sensor 5 is fixedly connected to the telescopic end of the first cylinder 4, and the other end is fixedly connected to the mounting bracket 41.

[0034] Thus, when the saw blade is tensioned, the saw blade applies a tension force to the mounting frame 41 through the movable roller 3. This tension force is transmitted to the tension sensor 5 through the mounting frame 41. The tension sensor 5 can detect the tension value in real time and convert it into an electrical signal to be sent to the controller of the band saw. Under normal cutting conditions, the tension value is maintained above a set normal threshold. Once the saw blade breaks, the tension of the saw blade on the movable roller 3 disappears instantly or decreases sharply. The tension value detected by the tension sensor 5 will drop rapidly. When the tension value is lower than the band breakage threshold set in the controller, the controller determines that the saw blade has broken and immediately issues a braking command.

[0035] Combination Figure 3 , Figure 4 and Figure 5 As shown, a brake block 6 is provided on the side of the movable roller 3 that contacts the saw blade. More precisely, the brake block 6 is located opposite the position where the movable roller 3 contacts the back of the saw blade. Since the saw blade is supported by the movable roller 3 at the movable roller 3, and the saw blade is in close contact with the outer circumferential surface of the movable roller 3, the brake block 6 is arranged opposite to the movable roller 3, and the saw blade passes between the two.

[0036] Furthermore, a spring-loaded drive unit is mounted on the mounting bracket 41, which is configured to push the brake block 6 toward the movable roller 3, thereby clamping the saw blade between the brake block 6 and the movable roller 3.

[0037] In a specific embodiment, the elastic drive unit includes a fixed frame 61, springs 62 and electromagnets 63. The fixed frame 61 is fixedly mounted on the mounting frame 41 by bolts or welding. The fixed frame 61 is located on the side of the brake block 6 away from the movable roller 3. A plurality of springs 62 are connected between the brake block 6 and the fixed frame 61. The springs 62 are preferably compression springs, with their two ends abutting against the brake block 6 and the fixed frame 61 respectively. The electromagnets 63 are fixedly mounted on the fixed frame 61, with the iron core of the electromagnets 63 facing the brake block 6. The brake block 6 is made of a magnetically conductive material that can be magnetically attracted, such as low carbon steel or pure iron.

[0038] Thus, under normal energization, electromagnet 63 generates magnetic force, attracting brake block 6 to its end face, while spring 62 is in a compressed, stored state. When electromagnet 63 is de-energized, the magnetic force disappears, and the compressive potential energy of spring 62 is released, pushing brake block 6 to move rapidly toward movable roller 3, thereby tightly clamping the saw blade located between brake block 6 and movable roller 3, achieving braking.

[0039] Furthermore, the elastic drive unit is also provided with guide rods 64. Guide rods 64 are arranged parallel to the moving direction of the brake block 6. One end of the guide rod 64 is fixedly connected to the brake block 6, and the other end passes through a guide hole opened on the fixing frame 61 and slides into the guide hole. Preferably, there are two or four guide rods 64, symmetrically distributed around the electromagnet 63, to ensure that the brake block 6 is subjected to uniform force and will not skew or jam.

[0040] Combination Figure 5 As shown, the brake block 6 has a brake surface 601 on one side facing the movable roller 3. This brake surface 601 is an arc surface that matches the outer circumferential surface of the movable roller 3. When the brake block 6 is pushed against the movable roller 3, the arc-shaped brake surface 601 can fit against the back of the saw blade to the maximum extent, pressing the saw blade evenly against the movable roller 3, increasing the contact area, and thus obtaining greater friction under the same spring force.

[0041] Furthermore, the braking surface 601 is also provided with anti-slip grooves, which can be mesh patterns, straight knurling, or wavy grooves, to increase the friction coefficient between the braking surface 601 and the saw blade and prevent the saw blade from slipping during braking.

[0042] Combination Figure 6 and Figure 7As shown, each clamping arm 13 has two rotatably connected limit rollers 14 at its bottom end, and the saw blade passes between the two limit rollers 14. The function of the limit rollers 14 is to guide the movement of the saw blade during normal cutting and prevent the saw blade from swinging left and right. The gap between the two limit rollers 14 is slightly larger than the thickness of the saw blade to ensure that the saw blade can pass freely without producing excessive wobbling.

[0043] Furthermore, the bottom end of the clamping arm 13 is also provided with two brake clamps 7, and the two brake clamps 7 are symmetrically distributed on both sides of the saw blade movement path. The bottom end of the clamping arm 13 is also fixed with a second cylinder 8. The second cylinder 8 is also a double-output cylinder, and its cylinder body is fixed on the clamping arm 13. The two telescopic ends are respectively fixedly connected to the two brake clamps 7. The second cylinder 8 is configured to drive the two brake clamps 7 to move closer or further away from each other.

[0044] Thus, under normal cutting conditions, the telescopic end of the second cylinder 8 is in the extended state, the two brake clamps 7 are far apart, and the saw blade passes freely through the gap between them; when the saw blade breaks, the controller issues a command, the two telescopic ends of the second cylinder 8 quickly retract, driving the two brake clamps 7 to move closer to each other, clamping the saw blade from both sides, and achieving auxiliary braking.

[0045] Furthermore, in order to increase the friction between the brake clamp 7 and the saw blade, friction surfaces 701 are fixed on the bottom sides of the two brake clamps 7 that are close to each other. The friction surfaces 701 can be made of wear-resistant rubber, polyurethane or metal sheets with rough surfaces, and anti-slip textures can also be provided on the friction surfaces 701.

[0046] This embodiment provides a method for braking a broken band saw blade, using the aforementioned band saw blade braking device, and includes the following steps: Step S1, Normal Cutting State During normal cutting operations, the two telescopic ends of the first cylinder 4 are in the retracted state. The movable roller 3, between the positioning rollers 2, stretches the saw blade outward, maintaining appropriate tension on the saw blade wrapped around the two pulleys 12 to ensure cutting accuracy and saw blade stability. At this time, the electromagnet 63 is energized, and the magnetic force generated by the electromagnet 63 attracts the brake block 6 to the end face of the electromagnet 63. A certain gap is maintained between the brake block 6 and the movable roller 3, allowing the saw blade to pass freely through this gap without contacting the brake block 6. Simultaneously, the spring 62 is compressed between the brake block 6 and the fixed frame 61, in a state of stored energy. The two telescopic ends of the second cylinder 8 are in the extended state, and the two brake clamps 7 are far apart, allowing the saw blade to pass through the gap between them without contact. The limiting roller 14 rotates freely, serving only as a guide and limiter.

[0047] Step S2: Band breakage detection and judgment During saw blade operation, tension sensor 5 continuously monitors the tension on movable roller 3 caused by saw blade tension and sends the detected value to the controller. The controller has pre-stored normal thresholds and belt breakage thresholds. When the detected tension value remains above the normal threshold, the controller determines that the saw blade is in good condition and continues normal operation. Once the saw blade breaks at some point, the tension around the two pulleys 12 will instantly disappear, and the tension of the saw blade on movable roller 3 will also drop sharply. When the tension value detected by tension sensor 5 rapidly decreases and falls below the belt breakage threshold, the controller immediately determines that the saw blade has broken and initiates the subsequent braking procedure.

[0048] Step S3: Disengage the drive wheel from the drive. Upon detecting a belt breakage, the controller immediately issues a command to rapidly extend the two telescopic ends of the first cylinder 4. This action serves two purposes: First, the extension of the first cylinder 4 drives the movable roller 3 inward, further relaxing the previously taut saw blade and reducing residual tension. Second, and more importantly, because the saw blade is bent at the pulley 12, when the movable roller 3 moves inward to release the saw blade length, the saw blade, under its own elastic restoring force, will naturally spring away in the tangential direction of the pulley 12, causing the saw blade to disengage from the outer circumference of the pulley 12. Once the saw blade is disengaged from the pulley 12, even if the drive wheel continues to rotate due to inertia, it can no longer drive the saw blade through friction, thus cutting off the power source for the saw blade's swing. Compared to existing technologies that rely solely on cutting off the motor power and waiting for the drive wheel to stop naturally, this solution actively disengages the saw blade from the drive wheel, achieving instantaneous cutting off of the driving force source and significantly shortening the time the saw blade continues to move.

[0049] Step S4: Emergency braking at the movable roller As the first cylinder 4 extends, the controller issues a command to de-energize the electromagnet 63. After the electromagnet 63 loses its magnetic force, the compressed spring 62 quickly releases its stored elastic potential energy, pushing the brake block 6 to move rapidly towards the movable roller 3 along the guide rod 64. Under the elastic pressure of the spring 62, the arc-shaped braking surface 601 of the brake block 6 tightly clamps the saw blade onto the outer circumference of the movable roller 3.

[0050] Because both the saw blade inlet and outlet ends of the pulley 12 are equipped with independent movable rollers 3 and brake blocks 6, when the saw blade breaks, the saw blades on both sides of the pulley 12 are independently clamped. As a result, the elastic release paths at both ends of the saw blade section that originally bent and stored energy at the pulley 12 are cut off by the brake blocks 6. The bent section of the saw blade cannot be ejected outward, and since the saw blade has disengaged from the pulley 12, the bent section of the saw blade can only bounce slightly in place and will not swing a long distance.

[0051] Step S5: Auxiliary braking at the clamping arm Synchronous with step S4, the controller issues a command to retract the two telescopic ends of the second cylinder 8, driving the two brake clamps 7 to move closer together. The friction surfaces 701 on the two brake clamps 7 clamp the saw blade from both sides, further increasing the braking force on the saw blade. Because the clamping arm 13 is close to the cutting section of the saw blade, it ensures that the saw blade in the cutting section and the surrounding area is also effectively restrained, preventing the saw blade from injuring the operator or damaging the equipment due to elastic vibration.

[0052] In summary, the above embodiments are implemented by setting tensioning roller sets at the saw blade inlet and outlet ends of the pulley 12. Each tensioning roller set includes two positioning rollers 2 and a movable roller 3 located between them. The saw blade passes around the rollers in an S-shape. The movable roller 3 is driven by a first cylinder 4. Tension sensors 5 are connected between the two telescopic ends of the first cylinder 4 and the mounting frame 41 to detect the saw blade tension in real time and determine whether the belt has broken. A spring drive unit and a brake block 6 are provided on the side of the movable roller 3. The spring drive unit includes a fixed frame 61, a spring 62, an electromagnet 63, and a guide rod 64. During normal cutting, the electromagnet 63 is energized to attract the brake block 6 and compress the spring 62. When the tension sensor 5 detects a sudden drop in tension and determines that the belt has broken, the controller commands the first cylinder 4 to extend quickly to loosen the saw blade and disengage it from the pulley 12, thereby cutting off the driving force of the drive wheel. At the same time, the electromagnet 63 is de-energized, and the spring 62 is released to push the brake block 6 to clamp the saw blade onto the movable roller 3. Through the synergy of actively disengaging from the drive wheel and instantaneously clamping and braking, the release and swinging of the elastic potential energy of the bent section of the saw blade are effectively suppressed.

[0053] Two brake plates 7 are symmetrically arranged on both sides of the saw blade's movement path at the bottom of the clamping arm 13. A second cylinder 8 is also fixed to the bottom of the clamping arm 13. The two telescopic ends of the second cylinder 8 are connected to the two brake plates 7 respectively, driving them to move closer or further apart. Friction surfaces 701 are fixed to the sides of the two brake plates 7 that are close to each other. During normal cutting, the second cylinder 8 extends, causing the two brake plates 7 to move further apart; when the saw blade snaps, the second cylinder 8 retracts, driving the two brake plates 7 to quickly close, clamping and braking the saw blade from both sides. This provides constraint on the saw blade's cutting section, preventing large-scale swinging caused by elastic vibration of the saw blade.

[0054] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0055] The embodiments have been described above, and such description is not restrictive. The figures shown are only one embodiment, and the actual structure is not limited to this. In short, if a person skilled in the art is inspired by this description and designs a similar structure and embodiment without departing from the inventive spirit, such design should fall within the scope of protection.

Claims

1. A band saw blade braking device, characterized in that, include: The lifting frame (1) has a tray (11) installed on both sides, and a pulley (12) is rotatably connected to each tray (11). Two clamping arms (13) are mounted on the lifting frame (1); Each of the pulleys (12) is provided with a tensioning wheel set at both the saw blade inlet and outlet ends. Each tensioning wheel set includes two positioning rollers (2) and a movable roller (3) located between the two positioning rollers (2). The saw blade alternately passes around the positioning rollers (2) and the movable roller (3). A first cylinder (4) is fixed between the saw blade inlet end and the saw blade outlet end of each pulley (12). The first cylinder (4) includes two telescopic ends, each telescopic end is connected to a mounting bracket (41). The mounting bracket (41) is connected to the movable roller (3) on the corresponding side. The first cylinder (4) is used to drive the movable roller (3) to move in order to adjust the tension of the saw blade. A brake block (6) is provided on the side of the movable roller (3) that contacts the saw blade. A spring drive unit is installed on the mounting frame (41). The spring drive unit is configured to push the brake block (6) toward the movable roller (3) so that the saw blade is clamped and braked.

2. The band saw blade braking device according to claim 1, characterized in that: A tension sensor (5) is connected between the two telescopic ends of the first cylinder (4) and the mounting bracket (41) to detect the tension of the saw blade in real time.

3. The band saw blade braking device according to claim 1, characterized in that: The elastic drive unit includes a fixed frame (61), springs (62) and electromagnets (63). The fixed frame (61) is fixed on the mounting frame (41). Multiple springs (62) are connected between the brake block (6) and the fixed frame (61). The electromagnets (63) are fixed on the fixed frame (61). The brake block (6) can be magnetically attracted to the electromagnets (63). When the electromagnet (63) is energized, the brake block (6) is attracted to the electromagnet (63), and the spring (62) is in a compressed and stored state. When the electromagnet (63) is de-energized, the spring (62) is released and pushes the brake block (6) to move toward the movable roller (3) so that the saw blade is clamped and braked.

4. The band saw blade braking device according to claim 3, characterized in that: The elastic drive unit also includes a guide rod (64), which is arranged parallel to the moving direction of the brake block (6). One end of the guide rod (64) is fixed to the brake block (6), and the other end of the guide rod (64) passes through the fixing frame (61) and slides with the fixing frame (61).

5. The band saw blade braking device according to claim 1, characterized in that: The brake block (6) has a brake surface (601) on one side facing the movable roller (3). The brake surface (601) is an arc surface that matches the outer circumferential surface of the movable roller (3) to increase the braking contact area.

6. The band saw blade braking device according to claim 5, characterized in that: The braking surface (601) is provided with anti-slip grooves to increase friction.

7. The band saw blade braking device according to claim 1, characterized in that: Two limiting rollers (14) are rotatably connected to one side of the bottom end of the clamping arm (13), and the saw blade passes between the two limiting rollers (14).

8. The band saw blade braking device according to claim 1, characterized in that: The bottom end of the clamping arm (13) is provided with two brake plates (7), and the two brake plates (7) are symmetrically distributed on both sides of the saw blade moving direction. The bottom end of the clamping arm (13) is also fixed with a second cylinder (8). The second cylinder (8) includes two telescopic ends and is respectively connected to the two brake plates (7). The second cylinder (8) is configured to drive the two brake plates (7) to move closer to or further away from each other.

9. The band saw blade braking device according to claim 8, characterized in that: The bottom ends of the brake plates (7) are each fixed with a friction surface (701) for increasing friction.

10. A method for braking a band saw blade in case of breakage, comprising the band saw blade braking device as described in any one of claims 1-9, characterized in that: Includes the following steps: S1. When the saw blade is cutting normally, the first cylinder (4) is in a contracted state, and the movable roller (3) pulls the saw blade in a tensioned state; the electromagnet (63) is energized, the brake block (6) is attracted to the electromagnet (63), and the spring (62) is compressed and stored; the second cylinder (8) is in an extended state, so that the two brake plates (7) are far apart from each other. S2. The tension sensor (5) detects the tension of the movable roller (3) due to the tension of the saw blade in real time. If the tension value detected by the tension sensor (5) remains above the set normal threshold, it is determined that the saw blade has not broken. If the detected tension value drops rapidly and is below the set breakage threshold, it is determined that the saw blade has broken. S3. When the saw blade breaks, the two telescopic ends of the first cylinder (4) extend quickly to further reduce the tension of the saw blade. Under the action of the elastic recovery force at the bending point of the saw blade, the saw blade is disengaged from the pulley (12), thus preventing the pulley (12) from continuing to apply driving force to the saw blade. S4. At the same time, the electromagnet (63) loses power and loses its magnetic attraction, the spring (62) is released, and the brake block (6) is pushed towards the movable roller (3). Under the elastic pressure of the spring (62), the saw blade is clamped and braked. At this time, the saw blade at the lead-in end and lead-out end of the pulley (12) is clamped, and the elastic force of the bent saw blade at the pulley (12) cannot be further released. S5. At the same time, the two telescopic ends of the second cylinder (8) retract, causing the two brake plates (7) to move closer to each other and clamp the saw blade for braking.

Images