Seat belt retractor vehicle sensing device and control method

Abstract

The application provides a vehicle sensing device for a seat belt retractor and a control method, which is applied to the technical field of vehicle safety devices, wherein the actuator is a metal pin-shaped component, and the actuator can move along the axial direction from the initial position to the actuation position of the pusher executor, when the vehicle encounters an emergency situation or the acceleration of the vehicle reaches a threshold value, the vehicle sensing device is driven to move to the actuation position by the electromagnetic drive assembly in response to a trigger signal and the generation of a magnetic field after energization, the actuator pushes the pusher executor to rotate and lock the seat belt retractor to protect the passenger, the vehicle sensing device is no longer limited to the horizontal installation state, the installation angle range of the vehicle sensing device and the retractor is expanded, and the vehicle sensing device has lower running noise and vibration noise.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle safety device, in particular to a vehicle sensing device for a safety belt retractor and a control method. BACKGROUND

[0002] During the driving of the automobile, if the automobile encounters an emergency, the safety belt retractor installed on the seat of the automobile can lock the safety belt, so that the safety belt cannot be released due to external force, thereby protecting the passenger and preventing the passenger from being harmed by the emergency of the automobile.

[0003] In the related art, there is a safety belt retractor, a vehicle sensing seat is installed on the bracket of the retractor, and the locking of the retractor is realized by the collision of a vehicle sensing body in the vehicle sensing seat. However, the vehicle sensing seat always needs to be in a horizontal state to realize stable locking, which limits the installation angle of the retractor.

[0004] Therefore, there is a need for a new technical solution. SUMMARY

[0005] Therefore, the present application provides a vehicle sensing device for a safety belt retractor and a control method.

[0006] The present application provides the following technical solutions:

[0007] According to the vehicle sensing device for a safety belt retractor provided by the present application, the safety belt retractor is locked when the vehicle acceleration reaches a threshold value to prevent the safety belt from being pulled out further. The vehicle sensing device comprises a housing, an electromagnetic assembly, and an actuator. The actuator is rotatably installed on the housing through a pin shaft. The electromagnetic assembly is installed on the housing and corresponds to the actuator. The electromagnetic assembly comprises an actuator and an electromagnetic driving assembly. The actuator is a metal pin-shaped component, and the actuator can move along the axis direction from an initial position to an actuating position for pushing the actuator. The electromagnetic driving assembly is used to generate a magnetic field to drive the actuator to move to the actuating position in response to a trigger signal and power supply.

[0008] Preferably, the electromagnetic assembly further comprises a frame having a first plate portion and a second plate portion arranged at a distance from each other. The electromagnetic driving assembly comprises an electromagnetic coil, a moving iron core, and a static iron core. The electromagnetic coil is arranged between the first plate portion and the second plate portion, and the electromagnetic coil forms an axial channel. The static iron core is fixed in the axial channel. The moving iron core sequentially passes through the second plate portion, the axial channel, the static iron core, and the first plate portion. The part of the moving iron core extending to the outside of the first plate portion constitutes the actuator, and the actuator forms a first limiting portion limiting the axial movement distance of the actuator.

[0009] Preferably, the static iron core is fixed at one end of the axial channel and close to the first plate portion, a conical cavity is formed at the end of the static iron core facing the second plate portion, and the moving iron core is sequentially formed with a wide diameter section, a transition section and a narrow diameter section along its own axial direction, and the outer contour of the transition section matches the inner contour of the conical cavity; when the actuator is in the actuating position, the transition section fits into the conical cavity, and the end of the narrow diameter section pushes the actuator.

[0010] Preferably, the angle between the contour of the conical cavity and the axis of the moving iron core is 15°~25°.

[0011] Preferably, a second limiting portion is formed on the wide diameter section outside the second plate portion, and a return spring is sleeved on the wide diameter section between the second plate portion and the second limiting portion; a washer is provided between the first plate portion and the first limiting portion.

[0012] Preferably, the frame also includes two side plate portions respectively connecting the first plate portion and the second plate portion, and the two end portions of the second plate portion located on the outside of the two side plate portions respectively form sliders; the shell includes a mounting base and two mounting side portions extending along a plane perpendicular to the mounting base, and the mounting side portions are respectively provided with a slide groove and a hook portion, and when the slider is engaged in the slide groove and moved to the mounting position, the hook portion is hooked on the edge of the side plate portion.

[0013] Preferably, the mounting side portion includes an elastic rod portion, the hook portion is fixed to the mounting base via the elastic rod portion, a notch is formed at the edge of the junction of the first plate portion and the two side plate portions, and the hook portion is hooked at the notch.

[0014] Preferably, the housing includes a mounting base and the pin shaft extending perpendicular to the plane where the mounting base is located, the actuator includes an actuator rod and a locking portion and a pivot portion respectively located at both ends of the actuator rod, the pivot portion is provided with a pin hole sleeved on the pin shaft, and the mounting base is also provided with a supporting side portion that can support the end of the pivot portion, and is configured such that the supporting side portion supports the end of the pivot portion to limit the rotational stroke of the actuator rod and / or the translation in the plane where the mounting base is located.

[0015] Preferably, the end profile of the pivot portion and the relative profile of the supporting side portion are mutually matching wedge-shaped surface structures, and when the actuator rod rotates to the maximum stroke, the end profile of the pivot portion fits with the supporting side portion.

[0016] Preferably, the pin shaft is composed of a number of elastic arms arranged at intervals in the circumferential direction, and the pin hole is sleeved on the outer circumference of the elastic arms. The actuator rod can translate to overcome the biasing action of the elastic arms when the locking part is subjected to external force, so that the end of the pivot part abuts against the supporting side.

[0017] Preferably, the actuator also includes a torsion spring, which includes a torsion portion, a first leg and a second leg. A mounting base surface is formed on the actuator rod, the outer periphery of the pin hole of the pivot portion forms a ring portion higher than the mounting base surface, the locking portion forms a boss portion higher than the mounting base surface, the supporting side portion is formed with a fixing groove, the torsion portion is sleeved on the outer periphery of the ring portion, the end of the first leg abuts against the side wall of the boss portion, and the end of the second leg is placed in the fixing groove. Under the biasing action of the torsion portion, the locking portion always rotates in a direction close to the actuator.

[0018] According to a control method also provided by the present application, a vehicle sensing device for a seat belt retractor described above is used to output a control current of the electromagnetic drive component, and the control current is set to multiple sections: in the actuator start triggering stage, the control current output gradually increases and then stabilizes to a first current, so that the actuator moves from the initial position to the actuating position; in the actuator maintaining triggering stage, the actuator and the seat belt retractor are locked, and the control current output is a second current smaller than the first current; in the actuator terminating triggering stage, the control current output gradually decreases, so that the actuator slowly returns from the actuating position to the initial position.

[0019] Compared with the prior art, the at least one technical solution adopted in this application can achieve the following beneficial effects:

[0020] In this application, when the vehicle encounters an emergency or detects that the vehicle acceleration reaches a threshold, the vehicle sensing device responds to the trigger signal through the electromagnetic drive component and generates a magnetic field to drive the actuator to the actuating position after power is applied. The actuator pushes the actuator to rotate and lock the seat belt retractor to protect the occupants. The vehicle sensing device is no longer limited to the horizontal installation state, which expands the installation angle range of the vehicle sensing device and the retractor, and the vehicle sensing device has lower operating noise and vibration noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0022] Figure 1 This is a first expanded schematic diagram of the vehicle sensing device in this application;

[0023] Figure 2 is a schematic diagram of the electromagnetic assembly in this application;

[0024] Figure 3 is a front view of the electromagnetic assembly of the actuator in the present application in the initial position;

[0025] Figure 4 is a cross-sectional view of the electromagnetic assembly of the actuator of the present application in an initial position;

[0026] Figure 5 is a front view of the electromagnetic assembly of the actuator in the present application in the actuated position;

[0027] Figure 6 is a cross-sectional view of the electromagnetic assembly of the actuator in the present application in the actuated position;

[0028] Figure 7 is a schematic diagram of the housing in this application;

[0029] Figure 8 is a top view of the housing in this application;

[0030] Figure 9 is a front view of the housing in this application;

[0031] Figure 10 is a side view of the housing in this application;

[0032] Figure 11 This is a second expanded schematic diagram of the vehicle sensing device of the present application;

[0033] Figure 12 This is a diagram showing the movement process of the vehicle sensing device of the present application from the initial position to the actuated position;

[0034] Figure 13 It is a schematic diagram of the actuator and the actuator of the present application being separated;

[0035] Figure 14 is a relationship diagram between the electromagnetic force and the displacement of the moving iron core before and after optimization of the present application;

[0036] Figure 15 This is a schematic diagram of the control current of the output electromagnetic drive component of the present application.

[0037] Figure numerals: 1. electromagnetic assembly; 11. moving iron core; 12. static iron core; 13. return spring; 14. side plate; 15. transition section; 16. second plate; 17. electromagnetic coil; 18. first limiting portion; 19. washer; 101. wire; 102. slider; 103. notch; 104. actuator; 105. first plate; 106. second limiting portion; 2. torsion spring; 3. actuator; 31. pin hole; 4. housing; 41. supporting side; 42. pin shaft; 43. hook; 44. slide groove; 45. hook-shaped structure; 46. mounting base; 47. mounting side; 5. locking gear; 61. first curve; 62. second curve; 7. base. DETAILED DESCRIPTION

[0038] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0039] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the features in the following embodiments and embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of this application.

[0040] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on this application, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspect described herein can be used to implement an apparatus and / or practice a method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this apparatus and / or practice this method.

[0041] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. The illustrations only show components related to the present application and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0042] Additionally, in the following description, specific details are provided to provide a thorough understanding of the examples, however, one skilled in the art will appreciate that the examples can be practiced without these specific details.

[0043] The following describes the technical solutions provided by various embodiments of the present application in conjunction with the accompanying drawings.

[0044] The embodiment of this specification proposes a vehicle sensing device for a seat belt retractor, such as Figure 1 、 Figure 5 as well as Figure 13 As shown, the vehicle sensing device is used to lock the seatbelt retractor to prevent further belt withdrawal when detecting that the vehicle acceleration reaches a threshold. The vehicle sensing device includes a housing 4, an electromagnetic assembly 1, and an actuator 3. The actuator 3 is rotatably mounted to the housing 4 via a pin 42. The electromagnetic assembly 1 is mounted on the housing 4 and corresponds to the actuator 3. The electromagnetic assembly 1 includes an actuator 104 and an electromagnetic drive assembly. The actuator 104 is a metal pin-shaped component that can move along its axis from an initial position to an actuated position that pushes against the actuator 3. The electromagnetic drive assembly is used to generate a magnetic field to drive the actuator 104 toward the actuated position in response to a trigger signal and upon energization. The initial position can be either a position where the brake and actuator 3 are separated or in contact. The actuated position can be the position of the actuator 104 when the actuator 3 is in contact and meshing with the retractor's locking gear.

[0045] In one embodiment, if Figure 1 、 Figure 2 as well as Figure 11 As shown, the electromagnetic assembly 1 further comprises a frame having a first plate portion 105 and a second plate portion 16 spaced apart from each other. Figure 3 、 Figure 4 and Figure 6 As shown, the electromagnetic drive assembly includes an electromagnetic coil 17, a moving iron core 11, and a stationary iron core 12. The electromagnetic coil 17 is positioned between the first plate portion 105 and the second plate portion 16, and an axial channel is formed in the electromagnetic coil 17. The first plate portion 105 and the second plate portion 16 are located at either end of the axial channel. The stationary iron core 12 is fixed within the axial channel. The moving iron core 11 passes through the second plate portion 16, the axial channel, the stationary iron core 12, and the first plate portion 105 in sequence. The portion of the moving iron core 11 extending outside the first plate portion 105 constitutes the actuator 104. The actuator 104 is formed with a first limiter 18 that limits its axial movement. The first limiter 18 abuts against the first plate portion 105 to constrain the actuator 104 to its initial position. The electromagnetic assembly 1 is a structure having an electromagnet. A wire 101 is connected to the electromagnetic coil 17.

[0046] In one embodiment, if Figure 3 and Figure 4As shown, the static iron core 12 is fixed at one end of the axial channel and is close to the first plate portion 105. A conical cavity is formed at the end of the static iron core 12 facing the second plate portion 16. The moving iron core 11 is sequentially formed with a wide diameter section, a transition section 15, and a narrow diameter section along its own axis. The outer contour of the transition section 15 matches the inner contour of the conical cavity. When the actuator 104 is in the actuation position, the transition section 15 fits in the conical cavity, and the end of the narrow diameter section pushes against the actuator 3. When the actuator 104 is in the actuation position, the wide diameter end and / or the transition section 15 abuts the portion of the static iron core 12, that is, the moving iron core 11 supports the static iron core 12. The first limiting portion 18 is annular and is installed on the narrow diameter section. The transition section 15 is the inclined surface of the moving iron core 11. A first limiting ring is provided on the static iron core 12 , and the first limiting ring is inserted through the first plate portion 105 around the narrow diameter section; a second limiting ring is provided at the bottom of the electromagnetic coil 17 , and the second limiting ring is inserted through the second plate portion 16 around the wide diameter section. Figure 4 OFF means off, in the initial position, and ON means on.

[0047] In one embodiment, if Figure 4 and Figure 14 As shown, the angle between the contour of the conical cavity and the axis of the moving iron core 11 is 15°~25°. Preferably, it is 20°. The moving iron core 11 and the static iron core 12 of this electromagnetic component 1 are both conical in design. The special angle of this cone at 20°-25° can make the holding force of the electromagnetic component 1 have an ideal holding force when the moving iron core 11 contacts the locking gear 5. Through this taper design, lower power consumption and smaller volume of the electromagnetic component 1 are achieved. The second curve 62 is the relationship between the electromagnetic force and the displacement of the moving iron core 11 before optimization, and the first curve 61 is after optimization. It can be seen that under a large stroke, the electromagnetic component 1 can still have a large holding force. Figure 14 In the figure, PULL FORCE CHARACTERISTICS represents pull characteristics; STROKE represents displacement of the moving iron core 11; FOROE represents electromagnetic force.

[0048] In one embodiment, if Figure 11 、 Figure 12 as well as Figure 13 As shown, the wide diameter section outside the second plate portion 16 forms a second stopper 106, and a return spring 13 is sleeved on the wide diameter section between the second plate portion 16 and the second stopper 106. A washer 19 is provided between the first plate portion 105 and the first stopper 18. The washer 19 is made of rubber, and the first and second stopper 18 and 106 are annular. The presence of the washer 19 in this electromagnetic assembly 1 prevents the moving iron core 11 from directly contacting the first plate portion 105 of the electromagnetic assembly 1 when deactivated, further reducing noise.

[0049] In one embodiment, if Figure 2 、 Figure 7 as well as Figure 11As shown, the frame further comprises two side plate portions 14 connecting the first plate portion 105 and the second plate portion 16 respectively, and the second plate portion 16 is formed with the slider 102 at both ends outside the two side plate portions 14; the housing 4 comprises a mounting base portion 46 and two mounting side portions 47 extending along a plane perpendicular to the mounting base portion 46, and the mounting side portions 47 are respectively provided with the slide groove 44 as a tenon and the hook portion 43 as a hook, when the slider 102 is embedded into the slide groove 44 and moved to the mounting position, the hook portion 43 is hooked on the edge of the side plate portion 14. The two side plate portions 14 are located at both sides of the first plate portion 105, and the two side plate portions 14 are fixedly connected with the second plate portion 16 at the ends, and a metal frame structure is formed by riveting, the first plate portion 105 and the two side plate portions 14 form a U-shaped metal upper housing, and the second plate portion 16 serves as a metal lower housing. Among them, the electromagnetic coil 17, the moving iron core 11, the static iron core 12, the metal upper housing and the metal lower housing constitute the electromagnetic loop of the electromagnetic assembly 1. The slider 102 is a special protruding structure of the second plate portion 16.

[0050] As shown in Figure 12 and Figure 13 , when the wire 101 is powered, the electromagnetic coil 17 is conducted to generate an electromagnetic field, and the electromagnetic field is conducted along the electromagnetic loop, so that the moving iron core 11 is magnetized, and the moving iron core 11 moves towards the static iron core 12. When the wire 101 is powered off, the magnetic field of the moving iron core 11 disappears, and the moving iron core 11 moves away from the static iron core 12 under the driving of the return spring 13 until the first limiting portion 18 and the washer 19 on the first plate portion 105 are in contact, and the movement is terminated.

[0051] In an embodiment, as shown in Figure 7 , Figure 9 and Figure 11 , the mounting side portion 47 comprises an elastic rod portion, the hook portion 43 is fixed on the mounting base portion 46 through the elastic rod portion, the edge of the first plate portion 105 at the junction with the two side plate portions 14 forms a notch 103, and the hook portion 43 is hooked at the notch 103. The notch 103 is a special recessed structure of the metal upper housing.

[0052] The metal lower housing has the slider 102, so as to be coupled with the slide groove 44 on the housing 4, thereby limiting the up-down and front-back movement of the electromagnetic assembly 1. The metal upper housing has the notch 103, so as to be coupled with the hook portion 43 on the housing 4, thereby limiting the left-right movement of the electromagnetic assembly 1 in the housing 4. As shown in Figure 7 , Figure 10 and Figure 13 , the mounting base portion 46 is provided with a hook-shaped structure 45 below, so as to be fixed with the base 7 of the retractor, thereby limiting the movement of the housing 4 relative to the base 7.

[0053] In an embodiment, as shown in Figure 7 , Figure 8 and Figure 13As shown, the housing 4 includes a mounting base 46 and a pin 42 extending perpendicularly to the plane of the mounting base 46. The actuator 3 includes an actuator rod, a locking portion, and a pivot portion located at each end of the actuator rod. The pivot portion is provided with a pin hole 31 that is sleeved on the pin 42. The mounting base 46 is further provided with a supporting side portion 41 that can support the end of the pivot portion. The supporting side portion 41 is configured to support the end of the pivot portion to limit the rotational travel of the actuator rod and / or translation in the plane of the mounting base 46. For example, the pin 42 can be elastically deformable. The thrust transmitted by the seat belt to the locking portion causes the pin 42 to elastically deform, and the supporting portion supports the supporting side portion 41, thereby receiving the thrust.

[0054] When the vehicle sensing device is triggered, the electromagnetic force drives the movable iron core 11 upward, driving the actuator 3 upward with it until it contacts the locking gear 5. At this point, if the locking gear 5 rotates counterclockwise, the actuator 3 meshes with the locking gear 5. After this engagement, the pin 42 deforms slightly until the actuator 3 contacts the abutment 41, transmitting the force from the locking gear 5 to the abutment 41. Therefore, when a high-load impact from the locking gear 5 occurs, the abutment 41 acts as a support structure, bearing the majority of the load and protecting the actuator 3.

[0055] In one embodiment, if Figure 13 As shown, the end profile of the pivot portion and the relative profile of the supporting side portion 41 are wedge-shaped surface structures that match each other. When the actuator rod rotates to the maximum stroke, for example, when the seat belt retractor drives the locking portion to rotate until the actuator rod is separated from the actuator 104, the end profile of the pivot portion fits with the supporting side portion 41, limiting the rotation of the actuator rod to lock the seat belt retractor.

[0056] The movable iron core 11 and actuator 3 are designed to be separate. When the actuator 3 engages the locking gear 5, the majority of the load impact moves horizontally, with a small portion borne by the actuator 3 and the majority borne by the supporting side 41. The movable iron core 11 is unaffected by the horizontal load impact, thus protecting the movable iron core 11 of the electromagnetic assembly 1. Furthermore, even if the movable iron core 11 is reset, the locking gear 5 remains engaged with the actuator 3, ensuring fail-safe operation.

[0057] In one embodiment, if Figure 7 as well as Figure 13 As shown, the pin 42 serves as a rotational bearing and is composed of a plurality of circumferentially spaced elastic arms. The pin hole 31 is sleeved around the outer periphery of the plurality of elastic arms. When the locking portion is subjected to an external force, the actuator rod can translate, overcoming the biasing action of the elastic arms, so that the end of the pivot portion abuts the supporting side portion 41. The elastic arms are correspondingly fixed with a clamping portion, and the plurality of clamping portions extend outwardly relative to the plurality of elastic shafts to prevent the actuator rod from being dislodged.

[0058] In one embodiment, Figure 1 and Figure 13 As shown, the actuator 3 also includes a torsion spring 2, which comprises a torsion portion, a first leg, and a second leg. A thin mounting base is formed on the actuator rod. The outer periphery of the pin hole 31 of the pivoting portion is formed into a ring portion that is higher than the mounting base. The locking portion is formed into a boss portion that is higher than the mounting base. A fixing groove is formed on the supporting side portion 41. The torsion portion is sleeved around the outer periphery of the ring portion. The end of the first leg abuts the side wall of the boss portion, and the end of the second leg is positioned in the fixing groove. Under the biasing action of the torsion portion, the locking portion always rotates toward the actuator 104. A limiting block is provided on the ring portion to constrain the torsion spring 2 between the limiting block and the pivoting portion. A guide block is formed on the side of the hook portion near the fixing ring. The pin hole 31 drives the pin shaft 42 to elastically deform, overcoming the biasing action of the elastic arm, allowing the ends of the first and second legs to slide through the guide block into the corresponding boss portion and fixing groove, respectively. The ends of the first and second legs are hook-shaped.

[0059] When the vehicle sensing device stops triggering, the moving iron core 11 is driven downward by the torsion spring 2 and the return spring 13, thereby achieving reset. This dual spring structure ensures the reset and locking of all moving parts of the vehicle sensing device, thereby further reducing vibration, noise and wear.

[0060] The embodiment of this specification also provides a control method, such as Figure 1 and Figure 15 As shown, a vehicle sensing device for a seat belt retractor using any of the above-mentioned embodiments outputs a control current of the electromagnetic drive component, and the control current is set to multiple sections: during the triggering stage of the actuator 3, i.e., the initial time period T0 and the first time period T1, the control current output gradually increases and then stabilizes to a first current, so that the actuator 104 moves from the initial position to the actuating position; during the triggering stage of the actuator 3, i.e., the second time period T2, the actuator 3 is locked with the seat belt retractor, and the control current output is a second current smaller than the first current; during the triggering stage of the actuator 3, i.e., the third time period T3, the control current output gradually decreases, so that the actuator 104 slowly returns from the actuating position to the initial position. Figure 15 In the formula, Lock means lock; Unlock means unlock; PWM means pulse width modulation; t means time; Duty1 means a first duty cycle, corresponding to a first current; and Duty2 means a second duty cycle, corresponding to a second current.

[0061] The vehicle sensing device of the present application includes an electromagnetic component 1, a return spring 13, an actuator 3 and a housing 4. When the vehicle is subjected to a large acceleration or angle, the vehicle sensing device will receive a signal from the vehicle's electronic control unit to trigger the electromagnetic component 1. The moving iron core 11 of the electromagnetic component 1 moves upward, thereby driving the actuator 3 to move upward, causing the gear to lock and the seat belt to lock. Compared with traditional sensors, it has the advantages of low operating noise, low vibration noise, and no restrictions on installation angles. The control current of this electromagnetic component 1 is set in multiple stages. When the actuator 3 is triggered, the electronic control unit gradually increases the current, so that the electromagnetic component 1 flexibly contacts the locking gear 5. When the trigger is completed and the actuator 3 needs to remain triggered, the electronic control unit emits a small current, thereby reducing heat and energy consumption. When the actuator 3 stops triggering, the actuator gradually reduces the current, causing the moving iron core 11 to slowly fall back, thereby reducing collision noise and wear.

[0062] In this specification, the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the embodiments described later, the description is relatively simple, and the relevant parts can be referred to the partial description of the previous embodiments.

[0063] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A vehicle sensing device for a seatbelt retractor, configured to lock the seatbelt retractor to prevent further withdrawal of the seatbelt when detecting that the vehicle's acceleration reaches a threshold; the vehicle sensing device comprises a housing, an electromagnetic assembly, and an actuator; the actuator is rotatably mounted on the housing via a pin, and the electromagnetic assembly is mounted on the housing and corresponds to the actuator, characterized in that: The electromagnetic assembly includes an actuator and an electromagnetic drive assembly. The actuator is a metal pin-shaped component and can move along its own axis from an initial position to an actuation position where it pushes against the actuator. The electromagnetic drive assembly is used to generate a magnetic field to drive the actuator to the actuation position in response to a trigger signal and when energized; The electromagnetic assembly further includes a frame having a first plate portion and a second plate portion spaced apart from each other, the electromagnetic drive assembly including an electromagnetic coil, a moving iron core, and a stationary iron core; the electromagnetic coil is disposed between the first plate portion and the second plate portion, and an axial channel is formed in the electromagnetic coil; the stationary iron core is fixed in the axial channel, the moving iron core sequentially passes through the second plate portion, the axial channel, the stationary iron core, and the first plate portion, the portion of the moving iron core extending to the outside of the first plate portion constituting the actuator, and the actuator is formed with a first limit portion for limiting its own axial movement distance; The static iron core is fixed at one end of the axial channel and close to the first plate portion. A conical cavity is formed at the end of the static iron core facing the second plate portion. The movable iron core is sequentially formed with a wide diameter section, a transition section, and a narrow diameter section along its own axis. The outer contour of the transition section matches the inner contour of the conical cavity. When the actuator is in the actuating position, the transition section fits into the conical cavity, and the end of the narrow diameter section pushes against the actuator. The housing includes a mounting base and the pin shaft extending perpendicular to the plane where the mounting base is located. The actuator includes an actuator rod and a locking portion and a pivot portion respectively located at both ends of the actuator rod. The pivot portion is provided with a pin hole sleeved on the pin shaft. The mounting base is also provided with a supporting side portion that can support the end of the pivot portion. It is configured that the supporting side portion supports the end of the pivot portion to limit the rotational stroke of the actuator rod and / or the translation in the plane where the mounting base is located.

2. The vehicle sensing device for a seat belt retractor according to claim 1, characterized in that: The included angle between the contour of the conical cavity and the axis of the moving iron core is 15° to 25°.

3. The vehicle sensing device for a seat belt retractor according to claim 1, characterized in that: A second limiting portion is formed on the wide diameter section outside the second plate portion, and a return spring is sleeved on the wide diameter section between the second plate portion and the second limiting portion; a washer is provided between the first plate portion and the first limiting portion.

4. The vehicle sensing device for a seat belt retractor according to any one of claims 1 to 3, characterized in that: The frame also includes two side plate portions respectively connecting the first plate portion and the second plate portion, and the two ends of the second plate portion located on the outside of the two side plate portions respectively form sliders; the shell includes a mounting base and two mounting side portions extending along a plane perpendicular to the mounting base, and the mounting side portions are respectively provided with a slide groove and a hook portion, and when the slider is engaged in the slide groove and moved to the mounting position, the hook portion is hooked on the edge of the side plate portion.

5. The vehicle sensing device for a seat belt retractor according to claim 4, characterized in that: The mounting side portion includes an elastic rod portion, the hook portion is fixed to the mounting base portion through the elastic rod portion, a notch is formed at the edge of the junction of the first plate portion and the two side plate portions, and the hook portion is hooked at the notch.

6. The vehicle sensing device for a seat belt retractor according to claim 1, characterized in that: The end profile of the pivot portion and the relative profile of the supporting side portion are mutually matching wedge-shaped surface structures. When the actuator rod rotates to the maximum stroke, the end profile of the pivot portion fits the supporting side portion.

7. The vehicle sensing device for a seat belt retractor according to claim 1, characterized in that: The pin shaft is composed of a number of elastic arms arranged at intervals in the circumferential direction, and the pin hole is sleeved on the outer circumference of the elastic arms. The actuator rod can translate to overcome the biasing action of the elastic arms when the locking part is subjected to external force, so that the end of the pivot part abuts against the supporting side part.

8. The vehicle sensing device for a seat belt retractor according to claim 1, characterized in that: The actuator also includes a torsion spring, which includes a torsion portion, a first leg and a second leg. A mounting base is formed on the actuator rod, and the outer periphery of the pin hole of the pivot portion forms a ring portion higher than the mounting base, and the locking portion forms a boss portion higher than the mounting base. A fixing groove is formed on the supporting side portion, and the torsion portion is sleeved on the outer periphery of the ring portion. The end of the first leg abuts against the side wall of the boss portion, and the end of the second leg is placed in the fixing groove. Under the biasing action of the torsion portion, the locking portion always rotates in a direction close to the actuator.

9. A control method, characterized in that: The vehicle sensing device for a seat belt retractor according to any one of claims 1 to 8 is applied to output a control current of the electromagnetic drive component, and the control current is set to multiple sections: in the actuator start triggering stage, the control current output gradually increases and then stabilizes to a first current, so that the actuator moves from the initial position to the actuating position; in the actuator maintaining triggering stage, the actuator and the seat belt retractor are locked, and the control current outputs a second current that is smaller than the first current; in the actuator termination triggering stage, the control current output gradually decreases, so that the actuator slowly returns from the actuating position to the initial position.

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