Automatic cutting dust removal device
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-04
- Publication Date
- 2026-08-11
AI Technical Summary
这种方式吸尘效率有限,且设备庞大、能耗高、移动不便,对于PVC圆管中残留的分成颗粒无法吸收
Smart Images

Figure CN224616541U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of cutting equipment technology, and in particular to automatic cutting and dust removal equipment. Background Technology
[0002] Polyvinyl chloride (PVC) round pipes are widely used in many core infrastructure fields such as building water supply and drainage, electrical wiring, agricultural irrigation, and communication networks due to their advantages such as corrosion resistance, high compressive strength, low cost, and good insulation properties. With the acceleration of urbanization and continuous investment in infrastructure construction, the market demand for PVC pipes is huge, and higher requirements are being placed on their processing efficiency, precision, and environmental protection. Cutting PVC pipes to the specific length required by the actual project is an essential and critical process in the production and installation of PVC pipes.
[0003] Currently, the industry mainly relies on two methods for cutting PVC round pipes: First, manual cutting: operators use hand saws or handheld cutting machines. This method has low equipment investment costs and high flexibility, but it suffers from problems such as tilted cut surfaces, numerous burrs, and poor length consistency. It heavily depends on the operator's skill level, resulting in low production efficiency and difficulty in meeting the needs of mass production. Second, semi-automatic cutting equipment: using simple clamps in conjunction with electric circular saws or band saws for cutting. This type of equipment improves cutting efficiency and cut quality to some extent, but it usually still requires manual loading and unloading and start-up, resulting in limited automation.
[0004] Both of these methods generate a large amount of harmful PVC dust during the cutting process. When PVC material is cut at high temperatures and through friction, it releases irritating gases such as hydrogen chloride (HCl) and fine plastic particles, thus polluting the environment surrounding the equipment. Current technologies for handling PVC dust typically involve installing large dust collection hoods near the cut points of PVC pipes, connected to a central dust collection system via pipes. This method has limited dust collection efficiency, and the equipment is bulky, energy-intensive, and inconvenient to move. Furthermore, it cannot absorb residual particulate matter within the PVC pipes.
[0005] In summary, this solution proposes an automatic cutting and dust removal device that can automatically unload materials and clean residual particles in PVC round pipes during the unloading process. Utility Model Content
[0006] The purpose of this utility model is to address the shortcomings of existing technologies by proposing an automatic cutting and dust removal device.
[0007] To achieve the above objectives, the technical solution adopted by this utility model is as follows: an automatic cutting and dust removal device, including a cutting frame, a partitioned belt conveyor installed on the top of the cutting frame, a first cover and a second cover sequentially installed on the top of the support of the partitioned belt conveyor along the direction of belt movement, a material drop guide cover installed on the top of the first cover, the material drop guide cover communicating with the inner cavity of the first cover, openings on two symmetrical sides of the first and second covers, windbreak curtains installed at the openings, dust collection connecting covers and multiple air jets respectively installed through the other two symmetrical sides of the first and second covers, a vacuum cleaner connected to the two dust collection connecting covers via a pipe, and a cutting mechanism provided above the first cover.
[0008] Preferably, the cutting mechanism includes a drive motor, a saw blade is mounted on the movable end of the drive motor, a saw blade cover is mounted on the housing of the drive motor, and the circumferential wall of the saw blade cover surrounds the circumference of the saw blade by more than a certain degree.
[0009] Preferably, a main mounting plate is provided on one side of the drive motor, and a second electric cylinder and two second slide rails are respectively mounted on the two symmetrical sides of the main mounting plate. A second slider is slidably provided on the surface of the two second slide rails, and a motor mounting plate is provided between the two second sliders. The housing of the drive motor is mounted on the side of the motor mounting plate.
[0010] Preferably, the top and bottom of the main mounting plate are each equipped with a first slider, and the sides of the cutting frame are respectively provided with first slide rails, with the first sliders slidably mounted on the surface of the first slide rails.
[0011] Preferably, a first electric cylinder is connected to the side of the main mounting plate, and the first electric cylinder is mounted on the side of the cutting machine frame.
[0012] Preferably, a rear dust collection hood is installed through the side of the main mounting plate, the rear dust collection hood and the saw blade are positioned correspondingly, and the rear dust collection hood is connected to the vacuum cleaner through a pipe.
[0013] Preferably, an electric cylinder mounting plate is provided on one side of the main mounting plate, and mounting rods are installed between the four corners of the electric cylinder mounting plate and the side of the main mounting plate. A fourth electric cylinder and a fifth electric cylinder are respectively installed on the side of the electric cylinder mounting plate. The fourth electric cylinder and the fifth electric cylinder are located on both sides of the saw blade. Two first clamping blocks and two second clamping blocks are respectively provided on the side of the main mounting plate and the electric cylinder mounting plate. The movable ends of the fourth electric cylinder and the fifth electric cylinder are respectively connected to one of the first clamping blocks and one of the second clamping blocks. The saw blade cover and the saw blade are located between the main mounting plate and the electric cylinder mounting plate.
[0014] Preferably, the main mounting plate and the electric cylinder mounting plate are provided with glass protective covers on their outer sides, and the glass protective covers cover the mounting plates and the electric cylinder mounting plates.
[0015] Preferably, a circular tube guide is installed through the side of the glass protective cover, and an end push plate corresponding to the position of the circular tube guide is installed on the side of the main mounting plate. An elongated hole is opened on the side of the end push plate, and a push rod is provided in the elongated hole. A mounting block is provided on the side of the end push plate, and a third electric cylinder is installed on the side of the mounting block. The movable end of the third electric cylinder passes through the mounting block and is connected to the push rod.
[0016] Preferably, a photoelectric sensor switch is installed on the surface of the cutting frame, and a sensor plate is installed on the side of the main mounting plate, with the sensor plate corresponding to the position of the photoelectric sensor switch.
[0017] Compared with the prior art, the present invention has the following beneficial effects: The cutting mechanism in this solution also integrates dust removal, clamping, cutting, material pushing, safety protection, and sensor control functions. While improving production efficiency and cutting quality, it greatly improves the cleanliness of the working environment and comprehensively protects the safety of operators.
[0018] This solution involves sequentially installing a first and a second cover on a partitioned belt conveyor. During the conveying process, gas is ejected through multiple jet nozzles. As the gas flows through the inner cavity of the PVC pipe, the flowing gas lifts up the particles inside the PVC pipe, and a vacuum cleaner sucks out the gas from the first and second covers. This facilitates the transport of the lifted particles to the vacuum cleaner for collection, thus improving the cleaning effect on the particles in the PVC pipe. Attached Figure Description
[0019] Figure 1 This is the first axonometric drawing of this utility model; Figure 2 This is the second axonometric drawing of the present invention; Figure 3 This is a cross-sectional view of the present invention; Figure 4 This is a connection diagram of the main mounting plate and drive motor of this utility model; Figure 5 This is a diagram showing the connection between the main mounting plate, the first electric cylinder, and the electric cylinder mounting plate of this utility model. Figure 6 This is a connection diagram of the saw blade and drive motor of this utility model; Figure 7 This is a connection diagram of the fourth and fifth electric cylinders of this utility model; Figure 8 This is a connection diagram of the third electric cylinder and push rod of this utility model; Figure 9 This is a diagram showing the connection between the first and second covers of this utility model.
[0020] In the diagram: 1. Vacuum cleaner; 2. Controller; 3. Product collection box; 4. Glass protective cover; 5. First cover; 6. Second cover; 7. Partitioned belt conveyor; 8. First electric cylinder; 9. Cutting frame; 10. Rear dust collection cover; 11. Second electric cylinder; 12. First slide rail; 13. First slider; 14. Saw blade cover; 15. Drive motor; 16. Material drop guide cover; 17. Windproof curtain; 18. First clamping block; 19. Second clamping block; 20. End push plate; 21. Air jet head; 22. Conveying air pipe; 23. Third electric cylinder; 24. Fourth electric cylinder; 25. Fifth electric cylinder; 26. Second slide rail; 27. Push rod; 28. Mounting block; 29. Main mounting plate; 30. Electric cylinder mounting plate; 31. Mounting rod; 32. Round tube guide; 33. Saw blade; 34. Dust collection connection cover; 35. Motor mounting plate; 36. PVC round tube; 37. Photoelectric sensor switch. Detailed Implementation
[0021] The following description is intended to disclose the present invention so that those skilled in the art can implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.
[0022] like Figure 1-9 The automatic cutting and dust removal equipment shown includes a cutting frame 9, with a partitioned belt conveyor 7 installed on the top of the cutting frame 9. A first cover 5 and a second cover 6 are sequentially installed on the top of the support of the partitioned belt conveyor 7 along the direction of belt movement. When the PVC round pipe 36 is conveyed sequentially in the first cover 5 and the second cover 6, multiple air jets 21 can blow air onto the PVC round pipe 36 in the first cover 5 and the second cover 6 in sequence, thereby improving the cleaning effect on residual particles in the PVC round pipe 36.
[0023] The top of the first cover 5 is equipped with a material drop guide 16, which is connected to the inner cavity of the first cover 5. The inclined surface of the material drop guide 16 can guide the PVC round pipe 36 as it falls, thereby improving the stability of the PVC round pipe 36 during material drop.
[0024] Both sides of the first housing 5 and the second housing 6 have openings, and windbreak curtains 17 are installed at the openings. As the partition belt conveyor transports the PVC round pipe 36, the PVC round pipe 36 will be blocked when it comes into contact with the windbreak curtain 17. However, as the partition belt conveyor continues to move, the partition of the partition belt conveyor will push the PVC round pipe 36 to break through the obstruction of the windbreak curtain 17 and continue to move. The main function of the windbreak curtain 17 is to reduce the outflow of gas in the first housing 5 and the second housing 6, increase the gas pressure in the first housing 5 and the second housing 6, and thus improve the cleaning effect of the vacuum cleaner 1 in sucking up residual particles.
[0025] The other two symmetrical sides of the first cover 5 and the second cover 6 are respectively equipped with a dust collection connection cover 34 and multiple air nozzles 21. The multiple air nozzles 21 are all connected to an air compressor through air pipes. The air compressor sprays gas through the multiple air nozzles 21, causing the gas to lift up the particles remaining inside the PVC round pipe 36. Combined with the suction force generated by the vacuum cleaner 1, the lifted particles are transported by the airflow through the dust collection connection cover 34 to the vacuum cleaner 1.
[0026] A vacuum cleaner 1 is connected between the two vacuum connection hoods 34 via a pipe. The vacuum cleaner 1 is an MCJC-5500 industrial vacuum cleaner with vacuuming and dust collection functions.
[0027] A cutting mechanism is provided above the first cover 5. The cutting mechanism includes a drive motor 15. A saw blade 33 is installed on the movable end of the drive motor 15. A saw blade cover 14 is installed on the outer shell of the drive motor 15. The circumferential wall of the saw blade cover 14 surrounds the circumference of the saw blade 33 by more than 180 degrees. The saw blade cover 14 protects the saw blade 33 and can also reduce the range of particle splashing when the saw blade 33 rotates.
[0028] A main mounting plate 29 is provided on one side of the drive motor 15. A second electric cylinder 11 and two second slide rails 26 are respectively mounted on the two symmetrical sides of the main mounting plate 29. Second sliders are slidably provided on the surfaces of the two second slide rails 26. A motor mounting plate 35 is provided between the two second sliders. The housing of the drive motor 15 is mounted on the side of the motor mounting plate 35. When the motor mounting plate 35 is acted upon by the second electric cylinder 11, the motor mounting plate 35 slides on the second slide rails 26 through the second sliders, thereby improving the stability of the motor mounting plate 35 during sliding.
[0029] The top and bottom of the main mounting plate 29 are each equipped with a first slider 13, and the sides of the cutting frame 9 are respectively provided with a first slide rail 12. The first slider 13 is slidably mounted on the surface of the first slide rail 12. The arrangement of the first slider 13 and the first slide rail 12 improves the stability of the main mounting plate 29 when it moves horizontally under force.
[0030] The side of the main mounting plate 29 is connected to the first electric cylinder 8, which is installed on the side of the cutting frame 9. When the first electric cylinder 8 retracts, the PVC round tube 36 is clamped and fixed. The first electric cylinder 8 pulls the main mounting plate 29 to move horizontally, moving the section of the PVC round tube 36 that needs to be cut to the top of the material guide cover 16, which facilitates the material unloading operation of the PVC round tube 36.
[0031] A rear dust collection hood 10 is installed through the side of the main mounting plate 29. The rear dust collection hood 10 corresponds to the position of the saw blade 33. The rear dust collection hood 10 is connected to the vacuum cleaner 1 through a pipe. When the saw blade 33 is rotating to cut the PVC round pipe 36, most of the particles carried by the saw blade 33 will splash into the rear dust collection hood 10. With the operation of the vacuum cleaner 1, the gas in the rear dust collection hood 10 carries the particles to the vacuum cleaner 1, which prevents the particles from flying into the working environment and plays a protective role in the working environment.
[0032] An electric cylinder mounting plate 30 is provided on one side of the main mounting plate 29. Mounting rods 31 are installed at the four corners of the electric cylinder mounting plate 30 and between the main mounting plate 29 and its side. A fourth electric cylinder 24 and a fifth electric cylinder 25 are respectively mounted on the side of the electric cylinder mounting plate 30, located on both sides of the saw blade 33. Two first clamping blocks 18 and two second clamping blocks 19 are respectively provided on the side of the main mounting plate 29 and the electric cylinder mounting plate 30. The movable ends of the fourth electric cylinder 24 and the fifth electric cylinder 25 are respectively connected to one of the first clamping blocks 18 and one of the second clamping blocks 19. The saw blade cover 14 and the saw blade 33 are located between the main mounting plate 29 and the electric cylinder mounting plate 30, within the PVC round pipe 3. Before cutting, the movable ends of the fourth electric cylinder 24 and the fifth electric cylinder 25 need to be extended. The movable ends of the fourth electric cylinder 24 and the fifth electric cylinder 25 push the first clamping block 18 and the second clamping block 19 to press on the surface of the PVC round tube 36 respectively. After the PVC round tube 36 is subjected to force, the surface of the PVC round tube 36 is also pressed against another first clamping block 18 and the second clamping block 19 to fix the position of the PVC round tube 36. After cutting, when it is necessary to unload the material, the movable end of the fourth electric cylinder 24 needs to be retracted first, which can drive the first clamping block 18 to separate from the PVC round tube 36. After the PVC round tube 36 is not pressed by external pressure, it is convenient for the PVC round tube 36 to fall onto the partitioned belt conveyor 7 for conveying.
[0033] The main mounting plate 29 and the electric cylinder mounting plate 30 are provided with a glass protective cover 4 on their outer sides. The glass protective cover 4 covers the mounting plate 29 and the electric cylinder mounting plate 30. The glass protective cover 4 is a mechanism for providing protection for the cutting mechanism during operation. It can also prevent the PVC round pipe from being splashed into the external environment during cutting. Moreover, when the glass protective cover 4 is transparent, it can also allow the staff to observe the cutting condition of the PVC round pipe.
[0034] A circular tube guide 32 is installed through the side of the glass protective cover 4. An end push plate 20 corresponding to the position of the circular tube guide 32 is installed on the side of the main mounting plate 29. An elongated hole is opened on the side of the end push plate 20, and a push rod 27 is installed in the elongated hole. An mounting block 28 is provided on the side of the end push plate 20, and a third electric cylinder 23 is installed on the side of the mounting block 28. The movable end of the third electric cylinder 23 passes through the mounting block 28 and is connected to the push rod 27. The circular tube guide 32 is used to improve the stability of the PVC circular tube when moving and prevent the position of the PVC circular tube from shifting. The end push plate 20 plays a limiting role on one end of the PVC circular tube to prevent the position of the PVC circular tube from shifting during cutting. After the PVC circular tube is cut, the push rod 27 can be pushed by the third electric cylinder 23. After the push rod 27 is subjected to force, it pushes the PVC circular tube to move, which facilitates the falling of the cut PVC circular tube.
[0035] A photoelectric sensor switch 37 is mounted on the surface of the cutting frame 9, and a sensor plate is mounted on the side of the main mounting plate 29. The sensor plate corresponds to the position of the photoelectric sensor switch 37. The photoelectric sensor switch 37 is connected to the controller 2 via wires, and the controller 2 is connected to the vacuum cleaner 1 via wires. The partitioned belt conveyor 7, the first electric cylinder 8, the second electric cylinder 11, the drive motor 15, the third electric cylinder 23, the fourth electric cylinder 24, and the fifth electric cylinder 25 are connected; the photoelectric sensor switch 37 is set parallel to the motion path of the main mounting plate 29, so that when the main mounting plate 29 drives the sensor plate to correspond with the sensing end of the photoelectric sensor switch 37, the photoelectric sensor switch 37 feeds back the information to the controller 2, and the controller 2 can conveniently control the above equipment to automatically complete the cutting and unloading of PVC round pipes.
[0036] In this scheme, controller 2 is an industrial computer.
[0037] Working principle: When cutting the PVC round tube 36, first insert one end of the PVC round tube 36 into the round tube guide 32, and continue to push the PVC round tube 36. After the PVC round tube 36 is subjected to force, it moves and presses one end against the side of the end push plate 20. Then, control the fourth electric cylinder 24 and the fifth electric cylinder 25 to work. The fourth electric cylinder 24 and the fifth electric cylinder 25 push the first clamping block 18 and the second clamping block 19 to press on the PVC round tube 36 to fix the position of the PVC round tube 36. Then stop the fourth electric cylinder 24 and the fifth electric cylinder 25 to complete the preparation work before cutting the PVC round tube 36. Next, the movable end of the first electric cylinder 8 is controlled to retract, and the first electric cylinder 8 pulls the main mounting plate 29 to move horizontally. The main mounting plate 29 drives the sensing plate to move synchronously. After the sensing plate moves to the photoelectric sensor switch 37 and is triggered, the photoelectric sensor switch 37 controls the first electric cylinder 8 to stop working through the controller 1. At this time, the main mounting plate 29 drives the PVC round pipe 36 to move above the material guide cover 16. Then, the movable end of the second electric cylinder 11 is controlled to retract, and the second electric cylinder 11 drives the motor mounting plate 35 to move downward. The motor mounting plate 35 drives the drive motor 15 and the saw blade 33 to move downward. At the same time, the drive motor 15 is started to work. The drive motor 15 drives the saw blade 33 to rotate. During the downward movement, the saw blade 33 cuts the surface of the PVC round pipe 36, completing the cutting operation of the PVC round pipe 36. After cutting, the movable end of the fourth electric cylinder 24 needs to be controlled to retract. At this time, the cut PVC round tube 36 is in an unfixed state. Then, the third electric cylinder 23 is controlled to push the push rod 27. After the push rod 27 is subjected to force, it pushes the PVC round tube 36 to move slightly, so that the cut PVC round tube 36 can fall down and be conveyed to the partition belt conveyor 7 through the material guide cover 16, thus completing the material dropping operation of the PVC round tube 36. As the partition belt conveyor 7 operates, the partitions in the partition belt conveyor 7 push the PVC round tubes to be conveyed sequentially in the first cover 5 and the second cover 6. The air compressor sprays gas through multiple jet nozzles 21. The gas lifts up the particles remaining inside the PVC round tube 36. Combined with the suction generated by the vacuum cleaner 1, the lifted particles are conveyed by the airflow through the vacuum cleaner connection cover 34 to the vacuum cleaner 1. At this time, it is used to clean up the residual particles. After cleaning, the partition belt conveyor 7 conveys the PVC round tube 36 to the product collection box 3. While cleaning up residual particles, the manual hand fixes one end of the PVC round tube 36 being cut, and simultaneously controls the drive motor 15 to stop working and the second electric cylinder 11, the first electric cylinder 8 and the fifth electric cylinder 25 to reset. During the reset process, since the position of the PVC round tube 36 is fixed, the side of the end push plate 20 can easily press against one end of the PVC round tube 36, making it convenient to control the cutting operation of the PVC round tube 36.
[0038] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.
Claims
1. An automatic cutting and dust removal device, comprising a cutting frame (9), characterized in that, The top of the cutting frame (9) is equipped with a partitioned belt conveyor (7). The top of the support of the partitioned belt conveyor (7) is equipped with a first cover (5) and a second cover (6) in sequence along the direction of belt movement. The top of the first cover (5) is equipped with a material drop guide cover (16). The material drop guide cover (16) and the inner cavity of the first cover (5) are connected. The two symmetrical sides of the first cover (5) and the second cover (6) are provided with openings. The openings are equipped with windproof curtains (17). The other two symmetrical sides of the first cover (5) and the second cover (6) are respectively equipped with dust collection connection covers (34) and multiple air jets (21). The two dust collection connection covers (34) are connected to a vacuum cleaner (1) through a pipe. The cutting mechanism is provided above the first cover (5).
2. The automatic cutting and dust removal equipment according to claim 1, characterized in that, The cutting mechanism includes a drive motor (15), on which a saw blade (33) is mounted. A saw blade cover (14) is mounted on the outer casing of the drive motor (15), and the circumferential wall of the saw blade cover (14) surrounds the circumference of the saw blade (33) by more than 180 degrees.
3. The automatic cutting and dust removal equipment according to claim 2, characterized in that, The drive motor (15) has a main mounting plate (29) on one side. The two symmetrical sides of the main mounting plate (29) are respectively equipped with a second electric cylinder (11) and two second slide rails (26). The surfaces of the two second slide rails (26) are slidably provided with second sliders. A motor mounting plate (35) is provided between the two second sliders. The housing of the drive motor (15) is installed on the side of the motor mounting plate (35).
4. The automatic cutting and dust removal equipment according to claim 3, characterized in that, The top and bottom of the main mounting plate (29) are each equipped with a first slider (13), and the sides of the cutting frame (9) are respectively provided with a first slide rail (12). The first slider (13) is slidably mounted on the surface of the first slide rail (12).
5. The automatic cutting and dust removal equipment according to claim 3, characterized in that, The side of the main mounting plate (29) is connected to a first electric cylinder (8), which is mounted on the side of the cutting frame (9).
6. The automatic cutting and dust removal equipment according to claim 3, characterized in that, A rear dust collection hood (10) is installed through the side of the main mounting plate (29). The rear dust collection hood (10) and the saw blade (33) are positioned correspondingly. The rear dust collection hood (10) is connected to the vacuum cleaner (1) through a pipe.
7. The automatic cutting and dust removal equipment according to claim 3, characterized in that, An electric cylinder mounting plate (30) is provided on one side of the main mounting plate (29). Mounting rods (31) are installed at the four corners of the electric cylinder mounting plate (30) and between the sides of the main mounting plate (29). A fourth electric cylinder (24) and a fifth electric cylinder (25) are respectively installed on the sides of the electric cylinder mounting plate (30). The fourth electric cylinder (24) and the fifth electric cylinder (25) are located on both sides of the saw blade (33). Two first clamping blocks (18) and two second clamping blocks (19) are respectively provided on the sides of the main mounting plate (29) and the electric cylinder mounting plate (30). The movable ends of the fourth electric cylinder (24) and the fifth electric cylinder (25) are respectively connected to one of the first clamping blocks (18) and one of the second clamping blocks (19). The saw blade cover (14) and the saw blade (33) are located between the main mounting plate (29) and the electric cylinder mounting plate (30).
8. The automatic cutting and dust removal equipment according to claim 3, characterized in that, The main mounting plate (29) and the electric cylinder mounting plate (30) are provided with glass protective covers (4) on their outer sides, and the glass protective covers (4) cover the mounting plate (29) and the electric cylinder mounting plate (30).
9. The automatic cutting and dust removal equipment according to claim 8, characterized in that, A circular tube guide (32) is installed through the side of the glass protective cover (4). An end push plate (20) corresponding to the position of the circular tube guide (32) is installed on the side of the main mounting plate (29). An elongated hole is opened on the side of the end push plate (20), and a push rod (27) is provided in the elongated hole. An mounting block (28) is provided on the side of the end push plate (20). A third electric cylinder (23) is installed on the side of the mounting block (28). The movable end of the third electric cylinder (23) passes through the mounting block (28) and is connected to the push rod (27).
10. The automatic cutting and dust removal equipment according to claim 3, characterized in that, A photoelectric sensor switch (37) is installed on the surface of the cutting frame (9), and a sensor plate is installed on the side of the main mounting plate (29). The sensor plate corresponds to the position of the photoelectric sensor switch (37).