Engine shutdown structure based on detection of broken belt at tensioning wheel

Abstract

The utility model provides an engine shutdown structure based on belt breakage detection at a tensioning wheel. The engine shutdown structure comprises a tensioning wheel mechanism. The detection mechanism is used for being matched with the tensioning wheel mechanism and detecting the belt breakage condition, the detection mechanism comprises a support and a microswitch fixed to the support, and the support is fixed to the tensioning wheel mechanism through bolts; the stopping mechanism is used for controlling starting and stopping of the fuel injection pump and comprises an electromagnet fixed to the fuel injection pump, a linkage pull rod is fixedly arranged at the lower end of the electromagnet, and the free end of the linkage pull rod is connected with a fuel injection pump stopping handle; the power source, the microswitch, the electromagnet and the power source are connected in series through a conductor wire and used for controlling the electromagnet to be powered on and powered off through on-off of the microswitch and achieving linkage of the detection mechanism and the shutdown mechanism, the mechanical broken belt trigger detection and electromagnetic shutdown structure is utilized, millisecond shutdown response can be achieved, automatic shutdown is achieved, and the safety of a belt conveyor is improved. And engine damage caused by belt breakage is avoided, and the shutdown accuracy rate is high.

Description

Technical Field

[0001] This utility model belongs to the field of engine testing technology, and in particular relates to an engine shutdown structure based on belt breakage detection at the tensioner pulley. Background Technology

[0002] The tensioner pulley is a component of an automotive engine. It automatically adjusts the tension of the belt using a hydraulic unit or damping spring, based on the belt's tightness, ensuring a stable, safe, and reliable transmission system. However, traditional tensioners only maintain belt tension and cannot actively detect belt breakage. Currently, one method relies on indirect fault signals, such as rising water temperature or sudden voltage drops, to trigger a shutdown. This method carries the risk of response delay. Another method uses electronic sensors, such as the existing patent CN107806990A, which monitors the phase difference between the BSG motor and engine speeds to warn of belt breakage. However, this method has the following drawbacks: Response delay: It relies on speed signals to calculate the phase difference, requiring accumulated data to trigger a warning, making real-time shutdown impossible; High false alarm rate: Vibration or load fluctuations can cause false phase difference signals, and electronic sensors are susceptible to electromagnetic interference or sensor failure, leading to false alarms; Inability to directly shut down: It only provides a warning and still requires manual intervention, failing to avoid the risk of sudden shutdown. Summary of the Invention

[0003] The problem this invention aims to solve is to provide an engine shutdown structure based on belt breakage detection at the tensioner pulley. By utilizing a mechanical belt breakage trigger detection and an electromagnetic shutdown structure, it can achieve millisecond-level shutdown response, realize automatic shutdown, avoid engine damage caused by belt breakage, and has a high shutdown accuracy.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: an engine shutdown structure based on belt breakage detection at a tensioner pulley, comprising: a tensioner pulley mechanism; a detection mechanism for cooperating with the tensioner pulley mechanism to detect belt breakage, the detection mechanism including a bracket and a micro switch fixed on the bracket, the bracket being bolted to the tensioner pulley mechanism; a shutdown mechanism for controlling the start and stop of the fuel injection pump, the shutdown mechanism including an electromagnet fixed on the fuel injection pump, a linkage rod fixedly provided at the lower end of the electromagnet, the free end of the linkage rod being connected to the fuel injection pump shutdown handle; and a power supply, the micro switch, the electromagnet, and the power supply being connected in series via conductive wires, for using the opening and closing of the micro switch to control the gain and loss of power to the electromagnet, thereby realizing the linkage between the detection mechanism and the shutdown mechanism.

[0005] Furthermore, the tensioning wheel mechanism includes a protective shell with a through cylindrical hole along its central axis. An annular cavity is formed between the cylindrical hole and the inner wall of the protective shell. A rotating shaft is inserted through the cylindrical hole. A protective shell bushing and an oil seal are provided between the rotating shaft and the cylindrical hole. A first through hole is provided at one end of the rotating shaft located in the annular cavity. A torsion spring is fixedly installed in the annular cavity. The short end of the torsion spring is located in the annular cavity and abuts against the outer wall of the cylindrical hole. The long end of the torsion spring passes through the first through hole with clearance fit. A second through hole is provided at the other end of the rotating shaft. The rotating shaft is fixedly connected to the support trigger arm through the second through hole and an elastic cylindrical pin. The other end of the support trigger arm is rotatably connected to an idler wheel through a bearing.

[0006] Furthermore, the outer wall of the protective shell is provided with a third through hole for fixed connection with the engine and a fourth through hole for mounting bracket.

[0007] Furthermore, the bracket includes a fixing part and a micro switch mounting part. The fixing part is provided with a fifth through hole that matches the fourth through hole and a sixth through hole that matches the third through hole. The micro switch mounting part is provided with a micro switch mounting hole. A limit baffle is provided on the fixing part below the micro switch mounting hole.

[0008] Further, the micro switch includes a metal housing. Inside the metal housing, from bottom to top, are sequentially arranged a first stepped hole, a second stepped hole, and a third stepped hole, with the diameters of these holes gradually increasing. A first stepped surface is provided between the first and second stepped holes, and a second stepped surface is provided between the second and third stepped holes. A plastic top post is inserted through the first stepped hole. A boss is provided above the plastic top post, contacting the first stepped surface. A first locking post is provided above the boss. A first metal moving contact and a second metal moving contact are sleeved on the first locking post. An annular insulating gasket is provided on the second stepped surface. A plastic cylindrical plug is interference-fitted into the third stepped hole. The end of the plastic cylindrical plug that contacts the annular insulating gasket is open. A seventh through hole and an eighth through hole are provided opposite each other on the upper surface of the plastic cylindrical plug. A ninth through hole is provided between the seventh and eighth through holes. A first metal terminal is inserted and fixed in the seventh through hole, a second metal terminal is inserted and fixed in the eighth through hole, and an insulating terminal and a third metal terminal disposed on the insulating terminal are inserted and fixed in the ninth through hole. The first metal movable contact includes a first contact part and a second contact part arranged vertically opposite each other. The first contact part passes through an annular insulating gasket and contacts the first metal terminal. The second contact part passes through an annular insulating gasket and contacts the second metal terminal. The second metal movable contact includes a third contact part arranged vertically. The third contact part passes through an annular insulating gasket and contacts the insulating terminal. A second locking post is provided at the top of the inside of the plastic cylindrical plug. The second locking post is arranged opposite to the first locking post. A first compression spring is fixedly disposed between the first locking post and the second locking post. An insulating baffle is provided at the top of the inside of the plastic cylindrical plug near the second metal terminal. The height of the lower end face of the insulating baffle is the same as the height of the upper end face of the insulating terminal.

[0009] Furthermore, the lower end of the metal casing is provided with an external thread, and a limit nut is provided above the external thread. The external thread of the metal casing passes through the micro switch mounting hole and is fixed to the micro switch mounting hole by the fixing nut and the limit nut.

[0010] Furthermore, the electromagnet includes a shell with an open bottom. A yoke is fixedly connected to the bottom of the shell via an internal thread. A circular boss is coaxially arranged on one side of the yoke inside the shell. A limiting piece is provided on the circular boss. A support block is provided at the top of the shell. An annular groove is provided on the support block. The annular groove is opposite to the circular boss. A magnetic shielding ring and a guide tube are fixedly arranged sequentially from bottom to top between the circular boss and the annular groove. The magnetic shielding ring and the guide tube have the same inner diameter and the contact point is provided with an anti-misalignment bevel. A first cavity is formed inside the magnetic shielding ring and the guide tube. A space is formed between the magnetic shielding ring and the guide tube and the side wall of the shell. The second cavity contains, from top to bottom, a second compression spring, an armature, and a push rod threaded to the lower end of the armature. The lower end of the push rod passes through a limiting plate and a yoke. A sliding bearing is installed on the outer wall of the armature with an interference fit at equal intervals. The outer diameter of the sliding bearing is clearance-fitted to the inner wall of the guide tube. From bottom to top, the second cavity contains, from bottom to top, a coil support ring, a holding coil, and a pull-in coil. The holding coil and pull-in coil are provided with holding coil wires, pull-in coil wires, and a common coil wire. The top of the housing has a circular hole through which the holding coil wires, pull-in coil wires, and common coil wires pass.

[0011] Furthermore, a spring positioning post is provided on the lower end face of the support block, and a spring slot is provided on the upper end of the armature. The second compression spring is fixedly disposed between the support block and the armature through the spring positioning post and the spring slot.

[0012] Furthermore, the lower end of the yoke is snapped with a dust cover, the lower end of the push rod is located inside the dust cover, the lower end of the push rod is provided with an internal threaded connection hole, the push rod is threadedly connected to the linkage rod through the internal threaded connection hole, the linkage rod includes a ball-and-socket tie rod, the upper end of the ball-and-socket tie rod is provided with an external thread rod that matches the internal threaded connection hole, the lower end of the ball-and-socket tie rod is provided with a ball-and-socket inner hole, a ball-end screw is movably provided in the ball-and-socket inner hole through a ball-and-socket plug, the lower end of the ball-end screw is threadedly connected to the tie rod hook through an adjusting nut, and the free end of the tie rod hook is fixedly connected to the fuel injection pump stop handle.

[0013] Furthermore, the common coil wire is connected to the second metal terminal circuit, the holding coil wire is connected to the negative terminal circuit, the positive terminal circuit is connected to the first metal terminal circuit, and a time delay switch is connected between the holding coil wire and the pull-in coil wire.

[0014] Compared with the prior art, the advantages and beneficial effects of this utility model are:

[0015] This invention features a detection mechanism mounted on the tensioner pulley and a shutdown mechanism on the fuel injection pump. The two mechanisms are linked by current signal feedback between a microswitch in the detection mechanism and an electromagnet in the shutdown mechanism. When the microswitch detects a belt breakage, it sends a signal to cut off the current. Upon receiving this signal, the electromagnet performs a shutdown action, which is transmitted to the fuel injection pump shutdown handle via a linkage rod, thus cutting off the fuel supply and achieving engine shutdown due to fuel shortage. This invention utilizes a mechanical belt breakage trigger detection and electromagnetic shutdown structure, achieving millisecond-level shutdown response and automatic shutdown, preventing engine damage caused by belt breakage and ensuring high shutdown accuracy. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the assembly structure of the tensioner mechanism and the testing mechanism.

[0017] Figure 2 This is a cross-sectional schematic diagram of the tensioner mechanism.

[0018] Figure 3 This is a schematic diagram of the protective casing in the tensioner mechanism.

[0019] Figure 4 yes Figure 3 A schematic diagram of the rear view structure.

[0020] Figure 5 This is a schematic diagram of the support structure of the testing facility.

[0021] Figure 6 This is a schematic diagram of the overall structure of the microswitch in the testing agency.

[0022] Figure 7 yes Figure 6 A schematic diagram of the structure of section AA.

[0023] Figure 8 This is a cross-sectional view of the metal casing of a micro switch.

[0024] Figure 9 This is a schematic diagram of the overall structure of the plastic cylindrical plug of the micro switch.

[0025] Figure 10 yes Figure 9 A schematic diagram of the cross-sectional structure.

[0026] Figure 11 This is a structural installation diagram of the metal moving contact and metal terminal block in a micro switch.

[0027] Figure 12 This is a cross-sectional schematic diagram of the electromagnet in the stopping mechanism.

[0028] Figure 13This is a cross-sectional schematic diagram of the linkage rod in the stopping mechanism.

[0029] Figure 14 This is a circuit connection diagram between the micro switch, power supply, and electromagnet.

[0030] Figure 15 This is a diagram showing the state of the tensioner mechanism and the detection mechanism when the belt is in normal condition.

[0031] Figure 16 This is a diagram showing the status of the shutdown mechanism and the fuel injection pump shutdown handle when the belt is in normal condition.

[0032] Figure 17 This is a diagram showing the state of the tensioner mechanism and the detection mechanism when the belt breaks.

[0033] Figure 18 This is a diagram showing the status of the shutdown mechanism and the fuel injection pump shutdown handle when the belt breaks.

[0034] In the diagram: 1-Bracket; 2-Micro switch; 3-Electromagnet; 4-Linkage rod; 5-Injection pump stop handle; 6-Power supply; 7-Shell; 8-Cylindrical through hole; 9-Annular cavity; 10-Rotating shaft; 11-Shell bushing; 12-Oil seal; 13-First through hole; 14-Torsion spring; 15-Second through hole; 16-Elastic cylindrical pin; 17-Bracket trigger arm; 18-Idler wheel; 19-Third through hole; 20-Fourth through hole; 21-Fixing part; 22-Micro switch mounting part; 23-Fifth through hole; 24-Sixth through hole; 2 5-Micro switch mounting hole; 26-Limit baffle; 27-Metal housing; 28-First stepped hole; 29-Second stepped hole; 30-Third stepped hole; 31-First stepped surface; 32-Second stepped surface; 33-Plastic top post; 34-Boss; 35-First locking post; 36-First metal moving contact; 37-Second metal moving contact; 38-Annular insulating gasket; 39-Plastic cylindrical plug; 40-Seventh through hole; 41-Eighth through hole; 42-Ninth through hole; 43-First metal terminal; 44-Second metal terminal 45-Insulated terminal post; 46-Third metal terminal post; 47-First contact foot; 48-Second contact foot; 49-Third contact foot; 50-Second locking post; 51-First compression spring; 52-Insulating baffle; 53-External thread; 54-Limit nut; 55-Fixing nut; 56-Housing; 57-Yoke; 58-Circular boss; 59-Limiting piece; 60-Support block; 61-Annular groove; 62-Magnetic shielding ring; 63-Guide tube; 64-First cavity; 65-Second cavity; 66-Second compression spring; 67-Armature; 68-Push rod; 69-Sliding bearing; 70-Coil support ring block; 71-Retaining coil; 72-Attracting coil; 73-Retaining coil wire; 74-Attracting coil wire; 75-Common coil wire; 76-Round hole; 77-Spring positioning post; 78-Spring slot; 79-Dust cover; 80-Internal threaded connection hole; 81-Ball socket pull rod; 82-External threaded rod; 83-Ball socket inner hole; 84-Ball socket plug; 85-Ball head screw; 86-Adjusting nut; 87-Pull rod hook; 88-Time delay switch. Detailed Implementation

[0035] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0036] like Figures 1-14As shown, an engine shutdown structure based on belt breakage detection using a tensioner pulley includes: a tensioner mechanism; a detection mechanism for cooperating with the tensioner mechanism to detect belt breakage, the detection mechanism including a bracket 1 and a micro switch 2 fixed on the bracket 1, the bracket 1 being bolted to the tensioner mechanism; a shutdown mechanism for controlling the start and stop of the fuel injection pump, the shutdown mechanism including an electromagnet 3 fixed on the fuel injection pump, a linkage rod 4 fixedly mounted at the lower end of the electromagnet 3, the free end of the linkage rod 4 being connected to the fuel injection pump shutdown handle 5; and a power supply 6, the micro switch 2, the electromagnet 3, and the power supply 6 being connected in series via conductive wires, for controlling the gain and loss of power to the electromagnet 3 by opening and closing the micro switch 2, thereby realizing the linkage between the detection mechanism and the shutdown mechanism.

[0037] This invention features a detection mechanism mounted on the tensioner pulley and a shutdown mechanism on the fuel injection pump. The two mechanisms are linked by current signal feedback between a microswitch 2 in the detection mechanism and an electromagnet 3 in the shutdown mechanism. When the microswitch 2 detects a belt breakage, it sends a signal to cut off the current. Upon receiving this signal, the electromagnet 3 performs a shutdown action, which is transmitted to the fuel injection pump shutdown handle 5 via a linkage rod 4, thus cutting off the fuel supply and achieving engine shutdown due to fuel shortage. This invention utilizes a mechanical belt breakage trigger detection and electromagnetic shutdown structure, achieving millisecond-level shutdown response and automatic shutdown, preventing engine damage caused by belt breakage and ensuring high shutdown accuracy.

[0038] Furthermore, the tensioning wheel mechanism includes a protective shell 7, with a through cylindrical hole 8 along the central axis of the protective shell 7. An annular cavity 9 is formed between the cylindrical hole 8 and the inner wall of the protective shell 7. A rotating shaft 10 is disposed through the cylindrical hole 8. A protective shell bushing 11 and an oil seal 12 are disposed between the rotating shaft 10 and the cylindrical hole 8. A first through hole 13 is provided at one end of the rotating shaft 10 located in the annular cavity 9. A torsion spring 14 is fixedly disposed in the annular cavity 9. The short end of the torsion spring 14 is located in the annular cavity 9 and abuts against the outer wall of the cylindrical hole 8. The long end of the torsion spring 14 passes through the first through hole 13 with clearance fit. A second through hole 15 is provided at the other end of the rotating shaft 10. The rotating shaft 10 is fixedly connected to the support trigger arm 17 through the second through hole 15 and an elastic cylindrical pin 16. The other end of the support trigger arm 17 is rotatably connected to an idler wheel 18 through a bearing.

[0039] Specifically, the protective bushing 11 and oil seal 12 inside the cylindrical through hole 8 are fixed by interference fit to form a support structure for the rotating shaft 10. The oil seal 12 prevents lubricating oil leakage and blocks external contaminants. Furthermore, an oil passage is provided inside the cylindrical through hole 8, allowing lubricating oil to penetrate to the surface of the rotating shaft 10 through the oil groove of the bushing, achieving automatic lubrication and reducing wear-induced rotational jamming of the support trigger arm 17. This structure is an existing tensioner lubrication structure, which is publicly available technology and will not be described in detail here. Additionally, the torsion spring 14 provides an initial preload, ensuring that the rotating shaft 10 is always subjected to an outward force. The torque of the belt is transmitted to the support trigger arm 17. At the same time, the support trigger arm 17 is radially fixed to the rotating shaft 10 through the elastic cylindrical pin 16, so that the torque of the rotating shaft 10 is transmitted to the support trigger arm 17. When the tension of the transmission belt changes, the support trigger arm 17 drives the idler wheel 18 to move, ensuring that the idler wheel 18 keeps in contact with the belt. The idler wheel 18 is mounted on the support trigger arm 17 through the bearing and can rotate freely around the shaft. When the belt is slack, the preload of the torsion spring 14 drives the rotating shaft 10 to move outward, and the idler wheel 18 moves closer to the belt to increase the tension. Conversely, if the belt is too tight, the idler wheel 18 moves back to release the tension.

[0040] Furthermore, the outer wall of the protective shell 7 is provided with a third through hole 19 for fixed connection with the engine and a fourth through hole 20 for mounting the bracket 1.

[0041] Furthermore, the bracket 1 includes a fixing part 21 and a micro switch mounting part 22. The fixing part 21 is provided with a fifth through hole 23 that matches the fourth through hole 20 and a sixth through hole 24 that matches the third through hole 19. The micro switch mounting part 22 is provided with a micro switch mounting hole 25. A limit baffle 26 is provided on the fixing part 21 below the micro switch mounting hole 25.

[0042] Specifically, the tensioner mechanism is fixed to the engine block by bolts through the third through hole 19 on the housing 7. The bracket 1 is fixed by bolts through the alignment of the fourth through hole 20 and the fifth through hole 23. The sixth through hole 24 is fixed by bolts through the alignment of the third through hole 19. The bracket 1 is always installed at an angle above the tail end of the bracket trigger arm 17. This is mainly used so that after the belt breaks, the bracket trigger arm 17 can contact the micro switch 2 to trigger the micro switch 2. At the same time, the setting of the limit baffle 26 can limit the position of the tail end of the bracket trigger arm 17 after the belt breaks, ensuring that the tail end is always in contact with the micro switch 2 after the breakage.

[0043] Further, the micro switch 2 includes a metal housing 27. Inside the metal housing 27, from bottom to top, are arranged a first stepped hole 28, a second stepped hole 29, and a third stepped hole 30. The diameters of the first stepped hole 28, the second stepped hole 29, and the third stepped hole 30 gradually increase. A first stepped surface 31 is provided between the first stepped hole 28 and the second stepped hole 29, and a second stepped surface 32 is provided between the second stepped hole 29 and the third stepped hole 30. A plastic top post 33 is inserted through the first stepped hole 28. A boss 34 is provided above the plastic top post 33, contacting the first stepped surface 31. A first locking post 35 is provided above the boss 34, and a second locking post 35 is sleeved on the first locking post 35. A first metal movable contact 36 and a second metal movable contact 37 are arranged perpendicularly and overlappingly. An annular insulating gasket 38 is provided on the second stepped surface 32. A plastic cylindrical plug 39 is interference-fitted into the third stepped hole 30. The end of the plastic cylindrical plug 39 that contacts the annular insulating gasket 38 is open. A seventh through hole 40 and an eighth through hole 41 are provided opposite to each other on the upper end face of the plastic cylindrical plug 39. A ninth through hole 42 is provided between the seventh through hole 40 and the eighth through hole 41. A first metal terminal 43 is inserted and fixed in the seventh through hole 40. A second metal terminal 44 is inserted and fixed in the eighth through hole 41. A fixed metal terminal 43 is inserted and fixed in the ninth through hole 42. The device includes an insulated terminal 45 and a third metal terminal 46 disposed on the insulated terminal 45. The first metal movable contact 36 includes a first contact portion 47 and a second contact portion 48 arranged vertically opposite each other. The first contact portion 47 passes through an annular insulating gasket 38 and contacts the first metal terminal 43. The second contact portion 48 passes through an annular insulating gasket 38 and contacts the second metal terminal 44. The second metal movable contact 37 includes a vertically arranged third contact portion 49, which passes through an annular insulating gasket 38 and contacts the insulated terminal 45. A second locking post 50 is disposed at the top of the inner end of the plastic cylindrical plug 39. The second locking post 50 is arranged opposite to the first locking post 35. A first compression spring 51 is fixedly installed between the post 35 and the second locking post 36. When the plastic top post 33 is squeezed, the first compression spring 51 is compressed, which drives the first metal moving contact 36 and the second metal moving contact 37 to move upward. After the squeezing force is removed, the first compression spring 51 drives the plastic top post 33 and the metal moving contact to reset. An insulating baffle 52 is provided at the inner top of the plastic cylindrical plug 39 near the second metal terminal post 44. The height of the lower end face of the insulating baffle 52 is the same as the height of the upper end face of the insulating terminal post 45. The setting of the insulating baffle 52 can realize the change of the internal current path of the micro switch 2. The annular insulating gasket 38, the plastic cylindrical plug 39 and the insulating baffle 52 are used to isolate the metal parts and prevent short circuit.

[0044] Furthermore, the lower end of the metal housing 27 is provided with an external thread 53, and a limit nut 54 is provided above the external thread 53. The external thread 53 of the metal housing 27 passes through the micro switch mounting hole 25 and is fixed to the micro switch mounting hole 25 by the fixing nut 55 and the limit nut 54.

[0045] Specifically, the micro switch 2 operates as follows: In the normal initial state, the lower end of the plastic top post 33 is not affected by external force. At this time, the top post extends the longest beyond the metal casing 27, the first compression spring 51 is in a compressed state, the first contact part 47 of the first metal moving contact 36 contacts the first metal terminal 43, the second contact part 48 contacts the second metal terminal 44, and the third contact part 49 of the second metal moving contact 37 contacts the insulated terminal 45. At this time, the circuit current path is: first metal terminal 43 - first contact part 47 - second contact part 48 - second metal terminal 44; when the belt breaks, the original tension of the tension wheel disappears instantly, and the idler wheel 18 is under the elastic force of the torsion spring 14. When the switch is moved outward, it drives the bracket trigger arm 17 to rotate. The tail end of the bracket trigger arm 17 rotates to point 26 of the micro switch bracket limit baffle. At the same time, the plastic top post 33 is pressed into the micro switch 2. During the pressing process, the second contact 48 disengages from the second metal terminal 44 and moves to the insulating baffle 52, while the third contact 49 moves from the insulating terminal 45 to the third metal terminal 46 for contact. At this time, the circuit current path is: first metal terminal 43 - first contact 47 - third contact 49 - third metal terminal 46, thereby completing the circuit switching. Through the circuit switching of the micro switch 2, the electromagnet 3 in the stop mechanism is energized or de-energized, thereby controlling the start and stop of the fuel injection pump.

[0046] Furthermore, the electromagnet 3 includes a housing 56 with an open bottom. A yoke 57 is fixedly connected to the bottom of the housing 56 via an internal thread. A circular boss 58 is coaxially arranged on one side of the yoke 57 inside the housing. A limiting piece 59 is provided on the circular boss 58. A support block 60 is provided at the top inside the housing 56. An annular groove 61 is provided on the support block 60. The annular groove 61 is opposite to the circular boss 58. A magnetic shielding ring 62 and a guide tube 63 are fixedly arranged between the circular boss 58 and the annular groove 61 from bottom to top. The inner diameter of the magnetic shielding ring 62 is equal to the outer diameter of the circular boss 58. The guide tube 63 is interference-fitted with the outer diameter of the annular groove 61. The magnetic shielding ring 62 and the guide tube 63 have the same inner diameter and the contact point is provided with an anti-misalignment bevel. The magnetic shielding ring 62 and the guide tube 63 form a first cavity 64. The magnetic shielding ring 62 and the guide tube 63 form a second cavity 65 between themselves and the side wall of the housing 56. The first cavity 64 is provided with a second compression spring 66, an armature 67 and a push rod 68 threaded to the lower end of the armature 67, arranged sequentially from top to bottom. The lower end of the push rod 68 passes through the limiting plate 59 and the yoke 57. The outer wall of the armature 67 is equidistantly fitted with sliding bearings 69. The outer diameter of the sliding bearing 69 is fitted with the inner wall of the guide tube 63 with a clearance. Inside the second cavity 65, from bottom to top, are arranged a coil support ring 70, a holding coil 71, and an attracting coil 72. The holding coil 71 and the attracting coil 72 are provided with holding coil wires 73, attracting coil wires 74, and a common coil wire 75. The top of the housing 56 has a circular hole 76 through which the holding coil wires 73, attracting coil wires 74, and common coil wire 75 pass. The magnetic shielding ring 62 reduces magnetic circuit leakage and optimizes magnetic field utilization. The contact surface between the magnetic shielding ring 62 and the guide tube 63... The anti-misalignment inclined surface design ensures that the components will not be misaligned during movement. The push rod 68 passes through the yoke 57 and the limiting plate 59 and is threadedly fixed to the inner hole of the armature 67. The movement of the push rod 68 is guided by the sliding bearing 69 on the surface of the armature 67 and the guide tube 63 with clearance fit, which effectively reduces frictional resistance. At the same time, the sliding bearings 69 are equidistantly installed on the armature 67 to achieve symmetrical distribution, enhance stability, and avoid off-center loading. Meanwhile, a dual-coil coordinated control is adopted. The attracting coil 72 provides an initial strong magnetic field to quickly complete the attracting action (short-term high current), while the holding coil 71 maintains a smaller magnetic field to keep the armature 67 in position (long-term low current), which saves energy and prevents overheating.

[0047] Furthermore, a spring positioning post 77 is provided on the lower end face of the support block 60, and a spring slot 78 is provided on the upper end of the armature 67. The second compression spring 66 is fixedly disposed between the support block 60 and the armature 67 through the spring positioning post 77 and the spring slot 78. The second compression spring 66 compresses and stores energy when the armature 67 is attracted, providing power for reset after power failure.

[0048] Furthermore, the lower end of the yoke 57 is snapped with a dust cover 79, and the lower end of the push rod 68 is located inside the dust cover 79. The yoke 57 and the dust cover 79 are snapped together for easy disassembly and maintenance. The lower end of the push rod 68 is provided with an internal threaded connection hole 80. The push rod 68 is threadedly connected to the linkage rod 4 through the internal threaded connection hole 80. The linkage rod 4 includes a ball-and-socket rod 81. The upper end of the ball-and-socket rod 81 is provided with an external threaded rod 82 that matches the internal threaded connection hole 80. The lower end of the ball-and-socket rod 81 is provided with a ball-and-socket inner hole 83. A ball-and-socket screw 85 is movably provided in the ball-and-socket inner hole 83 through a ball-and-socket plug 84. The lower end of the ball-and-socket screw 85 is threadedly connected to the rod hook 87 through an adjusting nut 86. The free end of the rod hook 87 is fixedly connected to the fuel injection pump stop handle 5.

[0049] Specifically, the body of the ball head screw 85 first passes through the inner hole of the ball socket plug 84, then the ball head of the ball head screw 85 is inserted into the inner hole 83 of the ball socket pull rod 81, then the outer diameter thread of the ball socket plug 84 is tightened to the inner hole 83 of the ball socket pull rod 81, the outer diameter of the pull rod hook 87 is screwed into the adjusting nut 86, and finally tightened to the inner hole thread of the ball head screw 85. Then, the linkage pull rod 4 and the push rod 68 are fixed together through the external thread rod 82 and the internal thread connection hole 80.

[0050] The adjusting nut 86 is used to adjust the extension length of the pull rod hook 87 and control the preload.

[0051] Furthermore, the common coil wire 75 is circuitally connected to the second metal terminal 44, the holding coil wire 73 is circuitally connected to the negative terminal of the power supply 6, the positive terminal of the power supply 6 is circuitally connected to the first metal terminal 43, and a time delay switch 88 is circuitally connected between the holding coil wire 73 and the pull-in coil wire 74.

[0052] Specifically, the linkage between the micro switch 2 and the electromagnet 3 is achieved through the connection between the wire and the terminal block. When the belt is in normal condition, the power supply 6 provides power. At this time, the micro switch 2 is energized and normally open, and the pull-in coil 72 and the holding coil 71 are energized. The current passes through the coils and generates a magnetic field. The magnetic field path is: pull-in coil 72 - holding coil 71 - armature 67 - magnetic isolation ring 62 - yoke 57 - housing 56 - support block 60 - armature 67, forming a closed magnetic circuit. The magnetic field attracts the armature 67 to move upward, compressing the second compression. Spring 66, push rod 68, and linkage rod 4 move upward. At this time, linkage rod 4 drives the fuel injection pump stop handle 5 to the working position, fuel is supplied normally, and the engine continues to run. When the belt breaks, the micro switch 2 circuit switches, causing the coil to be de-energized and the magnetic field to disappear. Armature 67 returns to its original position under the elastic force of the second compression spring 66, thereby driving push rod 68 and linkage rod 4 to move downward. At this time, linkage rod 4 drives the fuel injection pump stop handle 5 to the stop position, fuel is cut off, fuel injection stops, and the engine stops due to lack of fuel.

[0053] In this invention, the power supply 6 is a DC power supply of 12 / 24V, and the delay switch 88 is designed to close when there is no current and automatically disconnect the coil wire 74 after 6 seconds of power-on to prevent the coil 72 from being overloaded by a short-term high current.

[0054] like Figures 15-18 As shown, when the belt is in normal condition, it is taut, the tensioner pulley is in a balanced state, the micro switch 2 is energized and normally open, the electromagnet 3 is energized, which keeps the linkage rod 4 in the fuel passage and the engine runs normally. At the moment the belt breaks, the belt tension disappears, the torsion spring 14 drives the bracket trigger arm 17 of the tensioner pulley to rotate to the limit baffle 26, and the tail end of the bracket trigger arm 17 pushes the plastic top post 33 of the micro switch 2, causing the circuit to switch, the micro switch 2 is de-energized and closed, the electromagnet 3 is de-energized, which causes the linkage rod 4 to close the fuel line, and the engine stops due to lack of fuel.

[0055] The above description provides a detailed account of one embodiment of the present invention. However, this description is merely a preferred embodiment and should not be construed as limiting the scope of the present invention. All equivalent variations and improvements made within the scope of the claims of the present invention should still fall within the patent coverage of the present invention.

Claims

1. An engine stop structure based on a belt break detection at a tensioner pulley, characterized by: include, Tightening mechanism; A detection mechanism is used in conjunction with a tensioner mechanism to detect belt breakage. The detection mechanism includes a bracket and a micro switch fixed on the bracket. The bracket is bolted to the tensioner mechanism. A shutdown mechanism is used to control the start and stop of the fuel injection pump. The shutdown mechanism includes an electromagnet fixed on the fuel injection pump. A linkage rod is fixedly provided at the lower end of the electromagnet. The free end of the linkage rod is connected to the fuel injection pump shutdown handle. The power supply, including the micro switch, electromagnet, and power source, is connected in series via a conductive wire. This allows the micro switch to control the gain or loss of power to the electromagnet, thereby enabling the linkage between the detection mechanism and the shutdown mechanism.

2. The engine shutdown structure based on belt breakage detection at the tensioner pulley as described in claim 1, characterized in that: The tensioning wheel mechanism includes a protective shell with a through cylindrical hole along its central axis. An annular cavity is formed between the through cylindrical hole and the inner wall of the protective shell. A rotating shaft passes through the through cylindrical hole. A protective shell bushing and an oil seal are positioned between the rotating shaft and the through cylindrical hole. A first through hole is located at one end of the rotating shaft within the annular cavity. A torsion spring is fixedly installed within the annular cavity. The short end of the torsion spring is located within the annular cavity and contacts the outer wall of the through cylindrical hole. The long end of the torsion spring passes through the first through hole with clearance fitting. A second through hole is located at the other end of the rotating shaft. The rotating shaft is fixedly connected to a support trigger arm via the second through hole and an elastic cylindrical pin. The other end of the support trigger arm is rotatably connected to an idler wheel via a bearing.

3. The engine stop structure based on the belt break detection of the tensioner wheel according to claim 2, characterized by: The outer wall of the protective shell is provided with a third through hole for fixed connection with the engine and a fourth through hole for mounting brackets.

4. The engine stop structure based on the belt break detection of the tensioner wheel according to claim 3, characterized by: The bracket includes a fixing part and a micro switch mounting part. The fixing part is provided with a fifth through hole that matches the fourth through hole and a sixth through hole that matches the third through hole. The micro switch mounting part is provided with a micro switch mounting hole. A limit baffle is provided on the fixing part below the micro switch mounting hole.

5. The engine shutdown structure based on the belt break detection of the tensioner wheel according to claim 4, characterized by: The micro switch includes a metal housing. Inside the metal housing, from bottom to top, are arranged a first stepped hole, a second stepped hole, and a third stepped hole, with the diameters of these holes gradually increasing. A first stepped surface is provided between the first and second stepped holes, and a second stepped surface is provided between the second and third stepped holes. A plastic top post is inserted through the first stepped hole. A boss is provided above the plastic top post, contacting the first stepped surface. A first locking post is provided above the boss. A first metal moving contact and a second metal moving contact are sleeved on the first locking post. An annular insulating gasket is provided on the second stepped surface. A plastic cylindrical plug is interference-fitted into the third stepped hole. The end of the plastic cylindrical plug that contacts the annular insulating gasket is open. A seventh through hole and an eighth through hole are provided opposite each other on the upper surface of the plastic cylindrical plug. A ninth through hole is provided between the seventh and eighth through holes. A first metal terminal is inserted and fixed in the through hole; a second metal terminal is inserted and fixed in the eighth through hole; an insulating terminal and a third metal terminal disposed on the insulating terminal are inserted and fixed in the ninth through hole. The first metal movable contact includes a first contact part and a second contact part arranged vertically opposite each other. The first contact part passes through an annular insulating gasket and contacts the first metal terminal. The second contact part passes through an annular insulating gasket and contacts the second metal terminal. The second metal movable contact includes a third contact part arranged vertically. The third contact part passes through an annular insulating gasket and contacts the insulating terminal. A second locking post is provided at the top of the inside of the plastic cylindrical plug. The second locking post is arranged opposite to the first locking post. A first compression spring is fixedly disposed between the first locking post and the second locking post. An insulating baffle is provided at the top of the inside of the plastic cylindrical plug near the second metal terminal. The height of the lower end face of the insulating baffle is the same as the height of the upper end face of the insulating terminal.

6. The engine shutdown structure based on the belt break detection of the tensioner wheel according to claim 5, characterized by: The lower end of the metal casing is provided with an external thread, and a limit nut is provided above the external thread. The external thread of the metal casing passes through the micro switch mounting hole and is fixed to the micro switch mounting hole by the fixing nut and the limit nut.

7. The engine shutdown structure based on the belt break detection of the tensioner wheel according to claim 5, characterized by: The electromagnet includes a shell with an open bottom. A yoke is fixedly connected to the bottom of the shell via an internal thread. A circular boss is coaxially arranged on one side of the yoke inside the shell. A limiting piece is provided on the circular boss. A support block is provided at the top inside the shell. An annular groove is provided on the support block. The annular groove is opposite to the circular boss. A magnetic shielding ring and a guide tube are fixedly arranged sequentially from bottom to top between the circular boss and the annular groove. The magnetic shielding ring and the guide tube have the same inner diameter and the contact point is provided with an anti-misalignment bevel. A first cavity is formed inside the magnetic shielding ring and the guide tube. A second cavity is formed between the magnetic shielding ring and the guide tube and the side wall of the shell. The housing comprises, from top to bottom, a second compression spring, an armature, and a push rod threaded to the lower end of the armature. The lower end of the push rod passes through a limiting plate and a yoke. A sliding bearing is installed at equal intervals on the outer wall of the armature with an interference fit. The outer diameter of the sliding bearing is clearance-fitted with the inner wall of the guide tube. From bottom to top, the second cavity comprises, from bottom to top, a coil support ring, a holding coil, and a pull-in coil. The holding coil and pull-in coil are provided with holding coil wires, pull-in coil wires, and a common coil wire. A circular hole is provided at the top of the housing, through which the holding coil wires, pull-in coil wires, and common coil wires pass.

8. The engine shutdown structure based on the belt break detection of the tensioner wheel according to claim 7, characterized by: A spring positioning post is provided on the lower end face of the support block, and a spring slot is provided on the upper end of the armature. The second compression spring is fixedly installed between the support block and the armature through the spring positioning post and the spring slot.

9. The engine shutdown structure based on the belt break detection of the tensioner wheel according to claim 7, characterized by: The lower end of the yoke is snapped with a dust cover, and the lower end of the push rod is located inside the dust cover. The lower end of the push rod is provided with an internal threaded connection hole. The push rod is threadedly connected to the linkage pull rod through the internal threaded connection hole. The linkage pull rod includes a ball-and-socket pull rod. The upper end of the ball-and-socket pull rod is provided with an external threaded rod that matches the internal threaded connection hole. The lower end of the ball-and-socket pull rod is provided with a ball-and-socket inner hole. A ball-end screw is movably installed in the ball-and-socket inner hole through a ball-and-socket plug. The lower end of the ball-end screw is threadedly connected to the pull rod hook through an adjusting nut. The free end of the pull rod hook is fixedly connected to the fuel injection pump stop handle.

10. The engine shutdown structure based on the belt break detection of the tensioner wheel according to claim 7, characterized by: The common coil wire is connected to the second metal terminal circuit, the holding coil wire is connected to the negative terminal circuit of the power supply, the positive terminal of the power supply is connected to the first metal terminal circuit, and a time delay switch is connected between the holding coil wire and the pull-in coil wire.

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