Vehicle sensing device for safety belt retractor and control method

Abstract

The invention provides a vehicle sensing device for a safety belt retractor and a control method, and is applied to the technical field of vehicle safety device.An actuator is a metal pin-shaped component and can move from an initial position to an actuating position of a pushing and ejecting actuator in the axis direction of the actuator; when the vehicle encounters an emergency situation or detects that the acceleration of the vehicle reaches a threshold value, the vehicle sensing device responds to a trigger signal through the electromagnetic driving assembly and generates a magnetic field to drive the actuator to move towards the actuating position after being powered on, and the actuator pushes the actuator to rotate and lock the safety belt retractor to protect passengers. The vehicle sensing device is not limited by a horizontal installation state any more, the installation angle range of the vehicle sensing device and the retractor is enlarged, and the vehicle sensing device has low operation noise and vibration noise.

Description

Technical Field

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

[0002] During the driving process of the car, if the car encounters an emergency, the seat belt retractor installed on the vehicle seat can lock the seat belt so that the seat belt cannot be released due to external force, thereby protecting the occupants from the harm caused by the emergency situation of the car.

[0003] There is a seat belt retractor in the related art, in which a vehicle sensing seat is installed on a bracket of the retractor, and the retractor is locked by the collision of the vehicle sensing body in the vehicle sensing seat. However, the vehicle sensing seat always needs to be in a horizontal state to achieve stable locking, which results in a relatively limited installation angle of the retractor.

[0004] Based on this, a new technical solution is needed. Summary of the invention

[0005] In view of this, the present application provides a vehicle sensing device and a control method for a seat belt retractor.

[0006] This application provides the following technical solutions:

[0007] According to the present application, a vehicle sensing device for a seat belt retractor is provided, which is used to lock the seat belt retractor when detecting that the vehicle acceleration reaches a threshold value to prevent the seat belt from being further pulled out; the vehicle sensing device includes a shell, an electromagnetic component and an actuator; the actuator is rotatably mounted on the shell through a pin shaft, the electromagnetic component is mounted on the shell and corresponds to the actuator, the electromagnetic component includes an actuator and an electromagnetic drive component, the actuator is a metal pin-shaped component, and the actuator can move along its own axial direction from an initial position to an actuation position pushing the actuator, and the electromagnetic drive component is used to respond to a trigger signal and generate a magnetic field after power is supplied to drive the actuator to move to the actuation position.

[0008] Preferably, the electromagnetic component also includes a frame, the frame has a first plate portion and a second plate portion arranged at an interval from each other, and the electromagnetic drive component includes an electromagnetic coil, a moving iron core and a static iron core; the electromagnetic coil is placed between the first plate portion and the second plate portion, and the electromagnetic coil forms an axial channel; the static magnet is fixed in the axial channel, the moving magnet passes through the second plate portion, the axial channel, the static iron core and the first plate portion in sequence, and the part of the moving iron core extending to the outside of the first plate portion constitutes the actuator, and the actuator is formed with a first limit portion for limiting its own axial movement distance.

[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 the conical cavity, and the end of the narrow neck 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° to 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 gasket 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 where the first plate portion and the two side plate portions meet, 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 translational movement in the plane where the mounting base is located.

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

[0016] Preferably, the pin shaft is composed of a plurality of elastic arms arranged circumferentially at intervals, and the pin hole is sleeved on the outer circumference of the plurality of elastic arms. When the locking portion is subjected to an external force, the actuator rod can translate to overcome the biasing action of the elastic arms, so that the end of the pivot portion abuts against the supporting side portion.

[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, and 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 outputs a second current that is 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 beneficial effects that can be achieved by at least one of the above technical solutions adopted in the present application include at least:

[0020] In the present application, when the vehicle encounters an emergency or detects that the vehicle acceleration reaches a threshold, the vehicle sensing device responds to a trigger signal through an electromagnetic drive component and generates a magnetic field to drive the actuator to move to an actuating position after being energized. The actuator pushes the actuator to rotate and lock the seat belt retractor to protect the occupant. The vehicle sensing device is no longer limited to a 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 drawings required for use in the embodiments will be briefly introduced below. 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 paying creative work.

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

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

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

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

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

[0030] Fig. 9 is a front view of the housing in the present application;

[0031] Fig.10 is a side view of the housing in the present application;

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

[0033] Fig.12 is a diagram showing the movement process of the vehicle sensing device of the actuator of the present application from the initial position to the actuation position;

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

[0035] Fig.14 is a graph showing the relationship between the electromagnetic force and the displacement of the moving iron core before and after the optimization of the present application;

[0036] Fig.15 It is a control 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. stationary iron core; 13. reset 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 implementation methods 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 implementation methods, 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 following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present 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 the present 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 the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device 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 drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0042] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the examples can be practiced without these specific details.

[0043] The technical solutions provided by various embodiments of the present application are described below 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 Fig.13 As shown, it is used to lock the seat belt retractor when the vehicle acceleration reaches a threshold value to prevent the seat belt from being further pulled out; the vehicle sensing device includes a housing 4, an electromagnetic assembly 1 and an actuator 3; the actuator 3 is rotatably mounted on the housing 4 through 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, and the actuator 104 can move along its own axis from the initial position to the actuation position of the actuator 3, and the electromagnetic drive assembly is used to respond to the trigger signal and generate a magnetic field to drive the actuator 104 to move to the actuation position after power is turned on. The initial position can be the initial position where the brake is separated or in contact with the actuator 3. The actuation position can be the position of the actuator 104 when the actuator 3 is in contact and meshing with the locking gear of the retractor.

[0045] In one embodiment, if Figure 1 , Figure 2 as well as Fig.11 As shown, the electromagnetic assembly 1 also includes a frame, and the frame has a first plate portion 105 and a second plate portion 16 that are 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 static iron core 12; the electromagnetic coil 17 is placed between the first plate portion 105 and the second plate portion 16, and the electromagnetic coil 17 forms an axial channel, and the first plate portion 105 and the second plate portion 16 are located at both ends of the axial channel; the static magnet is fixed in the axial channel, the moving magnet passes through the second plate portion 16, the axial channel, the static iron core 12 and the first plate portion 105 in sequence, and the part of the moving iron core 11 extending to the outside of the first plate portion 105 constitutes the actuator 104, and the actuator 104 is formed with a first limit portion 18 that limits its own axial movement distance. The first limit portion 18 abuts against the first plate portion 105 to limit the actuator 104 to be in the initial position. The electromagnetic assembly 1 is a structure with an electromagnet. The electromagnetic coil 17 is connected to a wire 101.

[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 close to the first plate portion 105. The end of the static iron core 12 facing the second plate portion 16 forms a conical cavity. The moving iron core 11 is formed with a wide diameter section, a transition section 15 and a narrow diameter section in sequence along its own axial direction. 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 the conical cavity, and the end of the narrow neck section pushes the actuator 3. When the actuator 104 is in the actuation position, the wide diameter end and / or the transition section 15 abuts against the part 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 disposed 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 disposed 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, which is the initial position, and ON means on.

[0047] In one embodiment, if Figure 4 and Fig.14 As shown, the angle between the contour of the conical cavity and the axis of the moving iron core 11 is 15° to 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. Fig.14 In the figure, PULL FORCE CHARACTERISTICS represents the pulling force characteristics; STROKE represents the displacement of the moving iron core 11; FOROE represents the electromagnetic force.

[0048] In one embodiment, if Fig.11 , Fig.12 as well as Fig.13 As shown, the wide diameter section outside the second plate portion 16 is formed with a second limiting portion 106, and a reset spring 13 is sleeved on the wide diameter section between the second plate portion 16 and the second limiting portion 106; a washer 19 is provided between the first plate portion 105 and the first limiting portion 18. The washer 19 is made of rubber, and the first limiting portion 18 and the second limiting portion 106 are annular. This electromagnetic assembly 1 has a washer 19, so that the moving iron core 11 does not directly contact the first plate portion 105 of the electromagnetic assembly 1 when the trigger is terminated, thereby further reducing noise.

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

[0050] like Fig.12 and Fig.13 As shown, when the wire 101 is energized, the electromagnetic coil 17 is turned on to generate an electromagnetic field, and the electromagnetic field is turned on along the electromagnetic circuit, so that the moving iron core 11 is magnetized, and the moving iron core 11 moves toward the static iron core 12. When the wire 101 is de-energized, 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 drive of the return spring 13 until the first limit portion 18 contacts the washer 19 on the first plate portion 105, and the movement stops.

[0051] In one embodiment, if Figure 7 , Fig. 9 as well as Fig.11 As shown, the mounting side portion 47 includes an elastic rod portion, the hook portion 43 is fixed to the mounting base 46 through the elastic rod portion, and a notch 103 is formed at the edge of the junction between the first plate portion 105 and the two side plate portions 14, and the hook portion 43 is hooked at the notch 103. The notch 103 serves as a special indentation structure of the metal upper shell.

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

[0053] In one embodiment, if Figure 7 , Figure 8 as well as Fig.13As shown, the housing 4 includes a mounting base 46 and a pin 42 extending along a plane perpendicular to the mounting base 46, the actuator 3 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 31 sleeved on the pin 42, and the mounting base 46 is also provided with a supporting side portion 41 that can support the end of the pivot portion, and is configured such that the supporting side portion 41 supports the end of the pivot portion to limit the rotation stroke of the actuator rod and / or the translation in the plane where the mounting base 46 is located. For example, the pin 42 can be elastically deformed, and the thrust transmitted by the safety belt to the locking portion pushes the pin 42 to produce elastic deformation, and the supporting portion supports the supporting side portion 41, and the thrust is received by the supporting side portion 41.

[0054] When the vehicle sensing device is triggered, the moving iron core 11 is driven upward by the electromagnetic force, thereby driving the actuator 3 to move upward together until it contacts the locking gear 5. At this time, if the locking gear 5 rotates counterclockwise, the actuator 3 will mesh with the locking gear 5. After meshing, the pin 42 will deform slightly until the actuator 3 contacts the supporting side 41, so that the force of the locking gear 5 is transmitted to the supporting side 41. Therefore, when a high load impact from the locking gear 5 occurs, the supporting side 41, as a supporting structure, will bear most of the load and protect the actuator 3.

[0055] In one embodiment, if Fig.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, restricting the actuator rod from rotating and locking the seat belt retractor.

[0056] The moving iron core 11 and the actuator 3 are designed to be separated. When the actuator 3 is meshed with the locking gear 5, most of the load impact moves in the horizontal direction, a small part of the load is borne by the actuator 3, and most of the load is borne by the supporting side 41. The moving iron core 11 is not affected by the load impact in the horizontal direction, thereby achieving protection for the moving iron core 11 of the electromagnetic assembly 1. Moreover, even if the moving iron core 11 is reset, the locking gear 5 will still mesh with the actuator 3, thereby ensuring fault safety.

[0057] In one embodiment, if Figure 7 as well as Fig.13 As shown, the pin shaft 42 is used as a rotating bearing and is composed of a plurality of elastic arms arranged at intervals in the circumferential direction. The pin hole 31 is sleeved on the outer circumference of the plurality of elastic arms. The actuator rod can be translated when the locking portion is subjected to an external force to overcome the biasing action of the elastic arms, so that the end of the pivoting portion abuts against the supporting side portion 41. A clamping portion is correspondingly fixed on the elastic arm, and the plurality of the clamping portions extend outward relative to the plurality of the elastic shaft bodies to limit the actuator rod from coming out.

[0058] In one embodiment, if Figure 1 and Fig.13 As shown, the actuator 3 also includes a torsion spring 2, which includes a torsion portion, a first leg and a second leg. A mounting base with a relatively small thickness is formed on the actuator rod. The outer periphery of the pin hole 31 of the pivoting portion forms a ring portion higher than the mounting base surface, the locking portion forms a boss portion higher than the mounting base surface, and the supporting side portion 41 forms 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 the direction close to the actuator 104. A limiting block is provided on the ring portion to limit the torsion spring 2 between the limiting block and the pivoting portion. A guide block is formed on the side of the hook portion close to the fixing ring. The pin hole 31 drives the pin shaft 42 to produce elastic deformation to overcome the biasing action of the elastic arm, so that the end of the first leg and the end of the second leg slide into the corresponding boss portion and the fixing groove respectively through the guide block. The end of the first leg and the end of the second leg are in a hook shape.

[0059] When the vehicle sensing device is triggered, the moving iron core 11 is driven downward by the torsion spring 2 and the return spring 13 to achieve reset. This double 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 present specification also provides a control method, such as Figure 1 and Fig.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: in the triggering stage of the actuator 3, that is, the initial time period T0 and the first time period T1, the control current output gradually increases and then stabilizes to the first current, so that the actuator 104 moves from the initial position to the actuating position; in the triggering stage of the actuator 3, that is, 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; in the triggering stage of the actuator 3, that is, 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. Fig.15 Among them, 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; 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 receives 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, and 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 is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A vehicle sensing device for a seat belt retractor, used to lock the seat belt retractor to prevent the seat belt from being further pulled out when the vehicle acceleration reaches a threshold; the vehicle sensing device comprises a housing, an electromagnetic component and an actuator; the actuator is rotatably mounted on the housing through a pin, the electromagnetic component is mounted on the housing and corresponds to the actuator, and is characterized in that: The electromagnetic component includes an actuator and an electromagnetic drive component. The actuator is a metal pin-shaped component, and the actuator can move along its own axial direction from an initial position to an actuation position that pushes the actuator. The electromagnetic drive component is used to respond to a trigger signal and generate a magnetic field after power is turned on to drive the actuator to move to the actuation position.

2. The vehicle sensing device for a seat belt retractor according to claim 1, characterized in that: The electromagnetic assembly also includes a frame, which has a first plate portion and a second plate portion arranged at an interval from each other. The electromagnetic drive assembly includes an electromagnetic coil, a moving iron core and a static iron core; the electromagnetic coil is placed between the first plate portion and the second plate portion, and the electromagnetic coil forms an axial channel; the static magnet is fixed in the axial channel, and the moving magnet passes through the second plate portion, the axial channel, the static iron core and the first plate portion in sequence. The part of the moving iron core extending to the outside of the first plate portion constitutes the actuator, and the actuator is formed with a first limit portion for limiting its own axial movement distance.

3. The vehicle sensing device for a seat belt retractor according to claim 2, characterized in that: The static iron core is fixed at one end of the axial channel and close to the first plate portion, and a conical cavity is formed at the end of the static iron core facing the second plate portion. 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 the conical cavity, and the end of the narrow neck section pushes the actuator.

4. The vehicle sensing device for a seat belt retractor according to claim 3, 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°.

5. The vehicle sensing device for a seat belt retractor according to claim 3, 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.

6. The vehicle sensing device for a seat belt retractor according to any one of claims 2 to 5, 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 end portions of the second plate portion located outside 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.

7. The vehicle sensing device for a seat belt retractor according to claim 6, characterized in that: The mounting side portion comprises 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 between the first plate portion and the two side plate portions, and the hook portion is hooked at the notch.

8. The vehicle sensing device for a seat belt retractor according to any one of claims 1 to 5, characterized in that: 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. The mounting base is configured such that the supporting side portion supports the end of the pivot portion to limit the rotational travel of the actuator rod and / or the translation in the plane where the mounting base is located.

9. The vehicle sensing device for a seat belt retractor according to claim 8, characterized in that: The end profile of the pivoting portion and the relative profile of the supporting side portion are wedge-shaped surface structures that match each other. When the actuator rod rotates to the maximum stroke, the end profile of the pivoting portion fits the supporting side portion.

10. The vehicle sensing device for a seat belt retractor according to claim 8, characterized in that: The pin shaft is composed of a plurality of elastic arms arranged circumferentially at intervals, and the pin hole is sleeved on the outer circumference of the plurality of elastic arms. When the locking portion is subjected to an external force, the actuator rod can translate to overcome the biasing action of the elastic arms, so that the end of the pivot portion abuts against the supporting side portion.

11. The vehicle sensing device for a seat belt retractor according to claim 8, 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. 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. The torsion portion is sleeved on the outer periphery of the ring portion, and 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.

12. A control method, characterized in that: A vehicle sensing device for a seat belt retractor according to any one of claims 1 to 11 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 outputs a second current that is 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.

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