Belt buckle

Abstract

The present invention relates to a buckle including a buckle body having an insertion port into which a tongue plate connected to a safety belt of a vehicle is inserted, a housing accommodating the buckle body, a lever that rotates by receiving a load from the tongue plate in the insertion port, an elastic body that deforms by rotation of the lever, a sensor that outputs a signal corresponding to deformation of the elastic body, and a processing unit that processes the signal output from the sensor.

Description

Technical Field

[0001] This invention relates to a buckle. Background Technology

[0002] Traditionally, seatbelt buckles with pressure sensors are known to detect occupant breathing by detecting pressure changes caused by changes in seatbelt tension, with the emphasis on the fact that seatbelt tension changes according to the breathing of the seatbelt-wearing occupant (see, for example, Patent Document 1).

[0003] Previous technical documents

[0004] [Patent Literature]

[0005] Patent document 1: Japanese Patent Application Publication No. 2004-290324. Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] However, conventional pressure sensors are located between the buckle and the adhesive component outside the buckle. Therefore, conventional pressure sensors can measure the movement of the buckle relative to the adhesive component when the tongue is inserted into the buckle, but it is difficult to measure the movement of the tongue relative to the buckle.

[0008] This disclosure provides a buckle that can measure the movement of the tongue relative to the buckle when the tongue is inserted into the buckle.

[0009] The means used to solve technical problems

[0010] This manual provides the following technical solutions:

[0011] Buckles, including

[0012] The buckle body has an insertion port into which the tongue plate connected to the vehicle seat belt can be inserted;

[0013] The outer casing is used to house the buckle body;

[0014] The lever can rotate according to the load borne by the tongue plate inserted into the insertion port;

[0015] The elastic body deforms according to the rotational movement of the lever;

[0016] The sensor outputs a signal based on the deformation of the elastomer;

[0017] The processing unit is used to process the signals output by the sensor.

[0018] Invention Effects

[0019] According to this disclosure, when the tongue plate is inserted into the buckle, the movement of the tongue plate relative to the buckle can be measured.

[0020] Simple illustration

[0021] Figure 1 This is an external front view of the buckle according to an embodiment of the present invention.

[0022] Figure 2 This is a cross-sectional view of the buckle AA section according to an embodiment of the present invention.

[0023] Figure 3 This is an exploded view of the buckle according to an embodiment of the present invention.

[0024] Figure 4 This is an exploded view of the buckle component according to an embodiment of the present invention.

[0025] Figure 5 This is a cross-sectional view of the seatbelt tension detection device when the tongue plate is not inserted.

[0026] Figure 6 This is a cross-sectional view of the seat belt tension detection device after the tongue plate is inserted.

[0027] Figure 7 This is a cross-sectional view of a seatbelt tension detection device when a load is applied to the seatbelt.

[0028] Figure 8 This illustrates the positional relationship between a leaf spring and a lever in one embodiment of the elastomer.

[0029] Figure 9 It shows the lower surface of the lever (the surface opposite the leaf spring).

[0030] Figure 10 This is a cross-sectional view of the leaf spring when it is pushed by the first pressing part.

[0031] Figure 11 This is a cross-sectional view of the leaf spring being pushed by the first and second pressing parts.

[0032] Figure 12 This is a schematic diagram showing a leaf spring supported by multiple support members.

[0033] Figure 13 This is an example of the relationship between the load on the lever from the tongue and the length of the lever's rotational stroke. Detailed Implementation

[0034] For ease of understanding, the proportions of the parts in the diagram may differ from the actual proportions. Deviations in parallel, perpendicular, orthogonal, horizontal, vertical, up-down, left-right, and other directions are permissible without affecting the implementation effect. The X-axis, Y-axis, and Z-axis directions represent directions parallel to the X-axis, Y-axis, and Z-axis, respectively. The XY plane, YZ plane, and ZX plane represent directions parallel to the X-axis and Y-axis, respectively. The XY plane, YZ plane, and ZX plane represent virtual planes parallel to the X-axis and Y-axis, virtual planes parallel to the Y-axis and Z-axis, and virtual planes parallel to the Z-axis and X-axis, respectively.

[0035] Figure 1 The image shows an external front view of the buckle according to an embodiment of the present invention. Figure 2 The diagram shows a cross-sectional view of section AA of the buckle according to an embodiment of the present invention. The X-axis direction represents the width direction of the buckle 8; the Y-axis direction represents the height direction of the buckle 8 when it is installed on a vehicle; and the Z-axis direction represents the thickness direction of the buckle 8.

[0036] The buckle 8 is a detachably connected component to the tongue plate 7, which is attached to or near the passenger seat. The flat plate 7a of the tongue plate 7 can be inserted into and removed from the buckle 8. The tongue plate 7 is an example of a seatbelt insert through which the seatbelt 4 passes; the tongue plate 7 is a component slidably connected to the seatbelt 4. The seatbelt 4 is a webbing that secures the occupant to the car seat and is a strip of material that is retractably wound around a retractor.

[0037] The buckle 8 has a body 8a and a retainer 8b. The body 8a is the part that is detachably connected to the tongue plate 7. The retainer 8b is a support component that supports the body 8a of the buckle 8, and the retainer 8b is fixed to the passenger seat or the vehicle body near the seat.

[0038] When the tongue plate 7 is connected to the buckle 8, the portion of the seat belt 4 between the shoulder anchor (not shown) and the tongue plate 7 is the shoulder strap portion 9, used to restrain the occupant's chest and shoulders; when the tongue plate 7 is connected to the buckle 8, the portion of the seat belt 4 between the seat belt fastener (not shown) and the tongue plate 7 is the abdominal belt portion 10, used to restrain the occupant's waist.

[0039] Figure 3 An exploded view of the buckle according to an embodiment of the present invention is shown. Figure 4 An exploded view of the buckle component is shown. (Example) Figure 3 and Figure 4 As shown, the buckle 8 (body 8a) includes a buckle body 8c, a circuit board 16, an upper cover 12, a lower cover 14, a lever 40, and a leaf spring 50, which is one embodiment of an elastomer.

[0040] The buckle body 8c is a subassembly that connects to the tongue plate 7 attached to the seat belt 4. The buckle body 8c has a button 31 that accepts pressure from an occupant's finger to disconnect the buckle 8 from the tongue plate 7, and a buckle base 37 for securing the button 31 and other components of the buckle body 8c. The buckle body 8c has an insertion port 15 into which the tongue plate 7 is inserted.

[0041] The upper cover 12 is a plastic component that covers the buckle body 8c, exposing the button 31. The upper cover 12 clamps the buckle body 8c between the upper cover 12 and the lower cover 14. In this embodiment, a lever 40 is mounted on the upper cover 12. The lever 40 has a pivot 41 extending along the X-axis direction, supported on the upper cover 12, and the pivot 41 is rotatable about the upper cover 12.

[0042] The circuit board 16 is fixed to the inner surface of the lower cover 14. In this embodiment, the circuit board 16 has a sensor 20, a processing unit 60, and an output unit 80.

[0043] Sensor 20 detects the tension (hereinafter also referred to as "tension N") generated in the seat belt 4 and outputs an output signal based on the detected change in tension N. When an occupant wears the seat belt 4, the tension of the seat belt 4 changes because the occupant's body movements and chest and abdominal movements caused by breathing are transmitted to the seat belt 4. The change in tension N of the seat belt 4 is transmitted to the tongue plate 7, which in turn transmits the tension N to the buckle 8. Sensor 20 is located in the body 8a of the buckle 8.

[0044] Sensor 20 can detect deformation or displacement caused by changes in the tension N of the seat belt 4. For example, sensor 20 is a strain sensor or piezoelectric sensor used to detect changes in the tension N input from the seat belt 4 through the tongue 7 to the buckle 8. Sensor 20 can also be a capacitive sensor used to detect changes in capacitance caused by changes in the tension of the seat belt 4.

[0045] A capacitive sensor is one example of a non-contact sensor, but sensor 20 can be any other form of non-contact sensor. Sensor 20 can be an inductive sensor to detect changes in inductance caused by changes in the tension N of the seatbelt 4, or a magnetic sensor to detect changes in magnetism caused by changes in the tension N of the seatbelt 4. Sensor 20 can also be a sensor that detects deformation or displacement caused by changes in the tension N of the seatbelt 4 by reflecting transmitted light or radio waves.

[0046] The processing unit 60 processes the sensor signal output by the sensor 20, such as the process of amplifying a small sensor signal. This helps to process small analog sensor signals. The processing unit 60 can also filter the sensor signal.

[0047] For example, processing unit 60 detects vital signs, i.e., breathing or pulse, based on tension changes detected by sensor 20. For example, processing unit 60 detects vital signs, i.e., breathing or pulse, by detecting the periodicity of the signal component representing the tension N change in the output signal of sensor 20. If periodicity exists, it can be inferred that the tension change detected by sensor 20 is the periodic movement of the breathing or pulse of the occupant wearing seatbelt 4. Processing unit 60 detects vital signs by extracting the frequency component corresponding to the vital signs from the signal component representing the tension N change detected by sensor 20 using a predetermined filter. The period of the breathing signal is approximately 3 to 6 seconds, and the period of the pulse signal is approximately 0.5 to 1 second.

[0048] The processing unit 60 can detect the magnitude of the signal component representing the change in tension N from the output signal of the sensor 20. By detecting the magnitude of the signal component representing the change in tension N, the processing unit 60 can detect the magnitude of the tension, because the magnitude of the signal component corresponds to the magnitude of the tension N.

[0049] The processing unit 60 can determine whether the object on the vehicle seat is an occupant or a child seat based on the detection status of the buckle switch 13 and the vital signs detected by the processing unit 60. The detailed determination method is described below. A child seat, also known as a CRS (Child Restraint System), is an infant restraint system. Child seats are not only for infants but also for school-aged children.

[0050] Processing unit 60 is an integrated circuit that contains one or more computers (especially microcomputers). Processing unit 60 can be implemented by different integrated circuits or integrated into a single integrated circuit. A computer has a processor, such as a central processing unit (CPU), and memory. The processor runs according to the program stored in memory, implementing the various functions of processing unit 60. Each function of processing unit 60 can be implemented using an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit).

[0051] The output unit 80 outputs the processing results of the processing unit 60 (such as the amplified signal from the sensor, the result of determining whether it is an occupant or a child seat, etc.) to an external device with a buckle 8 via wired or wireless means. The external device executes predetermined control based on the determination result. For example, if the external device determines that the object on the seat is a passenger, it determines that the airbag needs to be deployed; if the object on the seat is a child seat, it determines that the airbag does not need to be deployed.

[0052] The output unit 80 outputs the decision result of the processing unit 60 to the outside of the buckle 8 through signals, light, sound, vibration or any combination thereof.

[0053] The lower cover 14 is an example of a housing, with the circuit board 16 fixed to its inner surface. The lower cover 14 is a plastic part that covers the circuit board 16.

[0054] The upper cover 12 and the lower cover 14 are the outer shells of the buckle 8, which house the buckle body 8c, the circuit board 16, the lever 40, and the leaf spring 50. In this embodiment, the outer shell of the buckle 8 consists of two parts, the upper cover 12 and the lower cover 14, for housing these components, but it can also consist of three or more parts.

[0055] When the buckle 8 is attached to the vehicle, the upper cover 12 faces away from the seatbelt wearer who is connected to the buckle 8 via the tongue plate 7, while the lower cover 14 faces the wearer.

[0056] Figure 5 , Figure 6 and Figure 7 A cross-sectional view of the seatbelt tension detection device is shown. When the tongue plate 7 is inserted into the buckle 8, the tip of the tongue plate 7 contacts the ejector 33. The ejector 33, pushed by the contact with the end of the tongue plate 7, moves in the direction of insertion of the tongue plate 7, causing the latch 34 to rotate and the slider 32 to descend. The rotating latch 34 engages with the tongue plate 7, and the slider 32 moves below the locking pin 35 (see...). Figure 6 ).

[0057] Insertion port 15 is the gap between button 31 and lever 40. The opening height e of insertion port 15 (see...) Figure 5 The height of the gap is determined by the shape of the lever 40 and the leaf spring 50, which makes the opening height e of the insertion port 15 at the initial position of the lever 40 slightly less than the thickness d of the tongue plate 7a. Therefore, in Figure 6 When the flat plate 7a of the tongue plate 7 is inserted into the port 15, the lever 40 is pushed at the point of action P2 by the flat plate 7a of the tongue plate 7, and rotates slightly clockwise around the pivot 41. The leaf spring 50 is pushed by the slightly rotated lever 40. The elastic force of the leaf spring 50 pushed by the lever 40 inhibits the wobbling of the flat plate 7a of the tongue plate 7 between the button 31 and the lever 40 (pre-tension area). Therefore, a small change in the seat belt tension N can be accurately transmitted to the sensor 20 through the flat plate 7a of the tongue plate 7, the lever 40 and the leaf spring 50, and the sensor 20 can detect the small change in tension N with high precision.

[0058] exist Figure 7In the process, the applied load (tension N) at the force point P1 of the tongue plate 7 causes the plate 7a of the tongue plate 7 to push the upper surface of the lever 40 at the point of action P2, with the upper wall 37a of the buckle base 37 as the fulcrum P3. The lever 40, which is pushed at the point of action P2, rotates clockwise around the pivot 41 and pushes the leaf spring 50. The leaf spring 50 bears the load and transmits the force to the sensor 20, while deflecting itself. The lower wall 37b of the buckle base 37 has a stop 38, which restricts the movement of the tongue plate 7 towards the lower wall 37b. The plate 7a of the tongue plate 7 contacts the stop 38, thereby preventing the tongue plate 7 from moving towards the lower wall 37b. The stop 38 limits the force applied to the sensor 20 through the lever 40 and the leaf spring 50, thereby protecting the sensor 20 from overload caused by impact.

[0059] The buckle 8 has a point of application P2 and a fulcrum P3 on its main body 8a. Point of application P2 represents the point where the rotational force (Fr) acts around the fulcrum P3 when the load F1 input to the tongue plate 7 is applied. The fulcrum P3 represents the center of rotation of the rotational force (Fr). The load F1 represents the force acting on the point of force P1 through the tension of the seat belt 4. When the flat plate 7a of the tongue plate 7 is inserted, the point of force P1 is located on the outside of the buckle 8, i.e., the base 7e in contact with the seat belt 4. A sensor 20 is also installed inside the buckle 8. In this embodiment, the sensor 20 outputs a signal based on the force acting on the point of application P2 (specifically, based on the deformation of the leaf spring 50).

[0060] As the tension of the seatbelt 4 increases, the load F1 increases in the direction shown by the arrow in the figure. Therefore, the tongue plate 7 connected to the buckle 8 is slightly pulled towards the occupant (pulled towards the lower cover 14 in the negative Z-axis direction). As the load F1 increases and the tongue plate 7 is displaced towards the occupant, the rotational force (Fr) acting on the point of action P2 also increases. Therefore, the force received by the sensor 20 from the point of action P2 through the lever 40 and the leaf spring 50 also increases.

[0061] Conversely, if the tension of the seat belt 4 decreases, the load F1 decreases, and the tongue plate 7 connected to the buckle 8 is pulled back to the side opposite to the occupant (towards the upper cover 12 in the positive Z-axis direction). When the load F1 decreases and the tongue plate 7 moves to the side opposite to the passenger, the rotational force (Fr) acting on the point of action P2 decreases, and therefore the force received by the sensor 20 from the point of action P2 through the lever 40 and the leaf spring 50 also decreases.

[0062] Therefore, based on the signal output by sensor 20 in response to the force at point P2, the displacement of the tongue plate 7 when the plate 7a is inserted into the buckle 8 can be measured by processing unit 60 or a similar device. Specifically, in this embodiment, the fulcrum P3 (i.e., the center of rotation of the rotational force Fr acting on P2) is not outside the buckle 8, but inside it. Since the fulcrum P3 is located inside the buckle 8, the magnitude of the force acting on point P2 will represent the relative displacement of the tongue plate 7 relative to the buckle 8. Therefore, when the plate 7a is inserted into the buckle 8, the relative movement of the tongue plate 7 relative to the buckle 8 can be measured by processing the signal output by sensor 20 in response to the force at point P2. The ability to measure the relative movement of the tongue plate 7 relative to the buckle 8 when the plate 7a is inserted makes it possible to measure the tension change of the seat belt 4, which is in direct contact with the tongue plate 7.

[0063] Traditional techniques for measuring the movement of the buckle relative to its external components struggle to accurately measure the movement of the latch connected to the buckle, because the buckle alters its transmission path when it contacts the seat cushion or the occupant's waist. Without accurately measuring the movement of the latch, it is difficult to accurately measure changes in seatbelt tension connected to the latch.

[0064] Conversely, in this embodiment, the fulcrum P3 is located within the buckle 8, so the force acting on the point of action P2 can be detected by the sensor 20 to measure the relative movement of the tongue plate 7 and the buckle 8. The tongue plate 7, connected to the buckle 8, is positioned less likely to disturb the occupant or seat than the buckle 8 itself. Therefore, by measuring the relative movement of the tongue plate 7 and the buckle 8, the movement of the tongue plate 7 can be stably measured regardless of whether the buckle 8 is in contact with the occupant.

[0065] By processing the signal output by sensor 20, the tension state of seat belt 4 can be measured, but other states can also be measured, such as the occupant's breathing state, the occupant's alertness state, etc.

[0066] When an occupant wearing seatbelt 4 breathes, the occupant's body surface (e.g., waist surface, abdomen surface, chest surface, etc.) will slightly displace in sync with breathing. For example, when the occupant inhales, the occupant's body surface expands in the front-to-back direction and the vehicle width direction, while when the occupant exhales, the occupant's body surface contracts in the front-to-back direction and the vehicle width direction. Since seatbelt 4 is in contact with the occupant's body surface, the tension of seatbelt 4 also changes synchronously with the occupant's breathing as the body surface moves synchronously with breathing. As the tension of seatbelt 4 changes synchronously with breathing, the load F1 input to the tongue plate 7 connected to seatbelt 4 also changes synchronously with breathing. Therefore, by processing the signal output by sensor 20 based on the force acting on the point of application P2, the occupant's breathing state can be measured.

[0067] Therefore, in this embodiment, the buckle 8 has a lever 40 that rotates due to the load borne by the plate 7a inserted into the insertion port 15; a leaf spring 50 that deforms due to the rotational movement of the lever 40; a sensor 20 that outputs a signal based on the deformation of the leaf spring 50; and a processing unit 60 that processes the signal output by the sensor 20. Thus, when the plate 7a of the tongue plate 7 is inserted into the buckle 8, the movement of the tongue plate 7 relative to the buckle 8 can be measured by the processing unit 60, etc.

[0068] The lever 40 and leaf spring 50 will be described in detail below.

[0069] Figure 8 The positional relationship between a leaf spring and a lever in one embodiment of the elastomer is shown. The point of application, P2, is located on the upper surface 42 of the lever 40. When a rotational force (Fr) is applied to the point of application, the lever 40 rotates and rotates about the pivot 41, pressing against the upper surface 51 of the leaf spring 50, with the lower surface 43 opposite to the upper surface 42.

[0070] Figure 9 The lower surface of the lever (the surface opposite the leaf spring) is shown. The pressing portion 44 is an example of a first pressing portion, in this embodiment a protrusion projecting from the center of the lower surface 43. The tip 44a of the pressing portion 44 contacts the upper surface 51 of the leaf spring 50. The pressing portion 45 is an example of a second pressing portion, in this embodiment a protrusion projecting from the edge of the lower surface 43. The pressing portion 45 has a tip 45a that contacts the upper surface 51 of the leaf spring 50. In the axial length direction of the pivot 41, the tip 45a of the pressing portion 45 is wider than the tip 44a of the pressing portion 44, and the tip 45a of the pressing portion 45 is further away from the tip 44a of the pressing portion 44.

[0071] Figure 10 This is a cross-sectional view showing the state in which the top 44a of the compressed portion 44 of the leaf spring 50 is pushed. Figure 11 This is a cross-sectional view showing the state in which the top end 44a of the compressed portion 44 and the top end 45a of the pressing portion 45 of the leaf spring 50 are pushed.

[0072] exist Figure 10 In the process, the flat plate 7a of the tongue plate 7 presses against the upper surface 42 of the lever 40 at the point of application P2. The lever 40, pressed by the flat plate 7a of the tongue plate 7 at the point of application P2, rotates clockwise around the pivot 41 and pushes the leaf spring 50 from the upper surface 51 with the end 44a of the pressing portion 44. The leaf spring 50 bears the load and transmits the force to the sensor 20, while also deflecting and deforming itself. The sensor 20 receives the force from the deformed leaf spring 50 and outputs a sensor signal corresponding to the magnitude of the force to the processing unit 60. Figure 10At the indicated time point, the tip 44a of the pressing portion 44 contacts the upper surface 51 of the leaf spring 50, but the tip 45a of the pressing portion 45 does not contact the upper surface 51 of the leaf spring 50.

[0073] exist Figure 11 In the process, as the rotational force Fr applied to the point of action P2 further increases, the lever 40 moves further clockwise around the pivot 41 and pushes the leaf spring 50 from the upper surface 51 with the top end 44a of the pressing portion 44 and the top end 45a of the pressing portion 45. As the leaf spring 50 deflects and deforms, it transmits the greater load it bears to the sensor 20.

[0074] Figure 12 A schematic diagram of a leaf spring supported by multiple support members is shown. The leaf spring 50 is a thin, plate-shaped elastomer, for example, made of stainless steel. The leaf spring 50 has a lower surface 52. The leaf spring 50 is supported from the lower surface 52 by multiple support members 53 (53a, 53b, 53c, 53d, 53e), for example, by multiple support members 53 fixed to the lower cover 14.

[0075] The leaf spring 50 in this embodiment comprises an M-shaped body 54 supported by five corners 56 (56a, 56b, 56c, 56d, 56e) and a cantilever 55 extending from the central portion 54b into the central gap 54a of the M-shaped body 54. The sensor 20 is located between the central corner 56c and the central portion 54b in the Z-axis direction of the leaf spring 50 and is in contact with the lower surface 52.

[0076] Angles 56a, 56b, 56c, 56d, and 56e are supported from the lower surface 52 by corresponding support components 53a, 53b, 53c, 53d, and 53e, respectively. Angles 56a, 56c, and 56e are angles aligned along the lower edge of the letter M, while angles 56b and 56d are angles aligned along the upper edge of the letter M.

[0077] The M-shaped body 54 has two sides 58 that clamp the cantilever 55. When the lever 40 rotates, initially only the cantilever 55 is pressed at the first contact line 57a by the top end 44a of the pressing portion 44 of the lever 40. As the lever 40 rotates further, the cantilever 55 is pressed at the first contact line 57a by the top end 44a of the pressing portion 44, and the two sides 58 are pressed at the second contact line 57b by the top end 45a of the pressing portion 45.

[0078] Therefore, the leaf spring 50 is an elastic structure comprising a cantilever 55 that deforms due to the rotational movement of the lever 40, and an M-shaped body 54 that deforms together with the cantilever 55 due to further rotational movement of the lever 40. The cantilever 55 is an example of a first elastic component, deforming due to the rotational movement of the lever 40; the M-shaped body 54 is an example of a second elastic component, deforming together with the first elastic component due to the rotational movement of the lever 40, acting as a secondary cantilever. The leaf spring 50 has this elastic structure and therefore possesses… Figure 13 The features shown.

[0079] Figure 13 An example illustrates the relationship between the load F (rotational force Fr) borne by lever 40 from the flat plate 7a of tongue plate 7 and the rotational stroke length S of lever 40 (FS characteristic). Figure 13 The FS characteristics are shown, where when the load F is in the first load region A1, the rate of change of the rotational stroke length S of the lever 40 relative to the load F is greater than the rate of change when the load F is in the second load region A2, the latter having a higher load force value than the first load region A1. In the first load region A1, the load F ranges from f0 to f1, representing the area where only the pressing portion 44 of the lever 40 presses against the leaf spring 50 (e.g., Figure 10 (As shown in the diagram). The second load area A2, with load F from f1 to f2, represents the area where the pressing portion 44 and the pressing portion 45 of the lever 40 push the leaf spring 50 (as shown in the diagram). Figure 11 (As shown). When the plate 7a contacts the stop block 38, the increase in the rotational stroke length S stops, and the rotational stroke length S remains unchanged even if the load F increases.

[0080] Figure 13 The FS characteristics shown indicate that the leaf spring 50 has elastic properties, and its elastic modulus varies with the magnitude of the load F. In this case, when the load F is located in the first load region A1, the elastic modulus of the leaf spring 50 is less than that in the second load region A2.

[0081] For example, leaf spring 50 has Figure 13 The FS characteristic shown can suppress the force applied to the sensor 20 by the leaf spring 50. Because in the pre-tightening area, the plate 7a is pre-tightened by pushing the leaf spring 50, the load F is small, and the force acting on the sensor 20 by the leaf spring 50 is also small. This can reduce the sensor characteristics of the sensor 20 from shifting due to excessive force on the sensor 20 in the pre-tightening area.

[0082] Although embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. Various changes and modifications can be made to the present invention, such as combinations or substitutions with some or all of the other embodiments.

[0083] The elastic body that deforms due to the rotational motion of the lever is not limited to leaf springs; it can also be other elastic bodies, such as pores.

[0084] This international application claims priority based on Japanese Patent Application No. 2021-109331, filed on June 30, 2021, the entire contents of which are incorporated herein by reference.

[0085] Symbol explanation:

[0086] 4. Seat belt

[0087] 7. Tongue plate

[0088] 8. Buckle

[0089] 8a main body

[0090] 8b. Cage

[0091] 8c. Buckle body

[0092] 12. Top cover

[0093] 13. Buckle switch

[0094] 14. Bottom cover

[0095] 15. Insertion port

[0096] 16. Circuit board

[0097] 20. Sensors

[0098] 38. Stop

[0099] 40. Lever

[0100] 41. Pivot

[0101] 42. Upper surface of the lever

[0102] 43. Lower surface of the lever

[0103] 50. Leaf spring

[0104] 51. Upper surface of leaf spring

[0105] 52. Lower surface of the leaf spring

[0106] 53, 53a, 53b, 53c, 53d, 53e, Support components

[0107] 54. M-shaped main body

[0108] 54a. Center gap

[0109] 54b, Central Part

[0110] 55. Cantilever; 56, 56a, 56b, 56c, 56d, 56e. Angle

[0111] 57a, First contact line

[0112] 57b, Second Contact Line

[0113] 58. Side

[0114] 60. Processing Unit

[0115] 70. Judgment Unit

[0116] 80. Output Unit

Claims

1. Buckles, including The buckle body has an insertion port into which the tongue plate connected to the vehicle seat belt can be inserted; The outer casing is used to house the buckle body; The lever can rotate according to the load borne by the tongue plate inserted into the insertion port; The elastic body deforms according to the rotational movement of the lever; The sensor outputs a signal based on the deformation of the elastic body, and the sensor receives the force generated by the deformation of the elastic body. A processing unit for processing the signal output by the sensor; The characteristic feature is that the elastic modulus of the elastomer varies with the magnitude of the load.

2. The buckle according to claim 1, characterized in that, The elastic body includes a first elastic component that deforms by the rotational movement of the lever and a second elastic component that deforms together with the first elastic component by the rotational movement of the lever.

3. The buckle according to claim 2, characterized in that, The lever includes a first pressing portion that presses the first elastic portion and a second pressing portion that presses the first elastic portion and the second elastic portion.

4. The buckle according to claim 1, characterized in that, The buckle body is provided with a stop to restrict the movement of the tongue plate inserted into the insertion port, thereby limiting the force applied to the sensor.

5. The buckle according to claim 1, characterized in that, The processing unit amplifies the signal.

6. The buckle according to claim 1, characterized in that, The processing unit detects vital signs based on the signal.

7. Buckles, including The buckle body has an insertion port into which the tongue plate connected to the vehicle seat belt can be inserted; The outer casing is used to house the buckle body; The lever can rotate according to the load borne by the tongue plate inserted into the insertion port; The elastic body deforms according to the rotational movement of the lever; The sensor outputs a signal based on the deformation of the elastic body, and the sensor receives the force generated by the deformation of the elastic body. A processing unit for processing the signal output by the sensor; The elastic body is characterized in that it includes a first elastic component that deforms by the rotational movement of the lever and a second elastic component that deforms together with the first elastic component by the rotational movement of the lever.

8. The buckle according to claim 2 or 7, characterized in that, The first elastic component is a cantilever, which deforms through the rotational movement of the lever; the second elastic component deforms together with the cantilever through the rotational movement of the lever.

9. The buckle according to claim 8, characterized in that, The second elastic component deforms together with the cantilever through the rotational movement.

10. The buckle according to claim 9, characterized in that, The second elastic component is an M-shaped body supported by five corners, and the cantilever is an arm that extends into the central gap of the M-shaped body.

11. The buckle according to claim 10, characterized in that, The M-shaped body has two sides that clamp the cantilever, and the lever includes a first pressing portion that pushes the cantilever and a second pressing portion that pushes the cantilever and the two sides.

12. The buckle according to claim 11, characterized in that, The second pressing portion is wider than the first pressing portion.

13. Buckles, including The buckle body has an insertion port into which the tongue plate connected to the vehicle seat belt can be inserted; The outer casing is used to house the buckle body; The lever can rotate according to the load borne by the tongue plate inserted into the insertion port; The elastic body deforms according to the rotational movement of the lever; The sensor outputs a signal based on the deformation of the elastomer; A processing unit for processing the signal output by the sensor; The characteristic feature is that when the load is in the first load region, the rate of change of the lever's rotational stroke length in response to the load is greater than the rate of change when the load is in the second load region, and the second load region is higher than the first load region.

14. Buckles, including The buckle body has an insertion port into which the tongue plate connected to the vehicle seat belt can be inserted; The outer casing is used to house the buckle body; The lever can rotate according to the load borne by the tongue plate inserted into the insertion port; The elastic body deforms according to the rotational movement of the lever; The sensor outputs a signal based on the deformation of the elastomer; A processing unit for processing the signal output by the sensor; The lever is characterized in that it is supported by the outer shell and is capable of rotational movement.

15. Buckles, including The buckle body has an insertion port into which the tongue plate connected to the vehicle seat belt can be inserted; The outer casing is used to house the buckle body; The lever can rotate according to the load borne by the tongue plate inserted into the insertion port; The elastic body deforms according to the rotational movement of the lever; The sensor outputs a signal based on the deformation of the elastomer; A processing unit for processing the signal output by the sensor; The characteristic feature is that the opening height of the insertion port when the lever is in its initial position is smaller than the thickness of the tongue plate.

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