Locking device for a buckle of a seat belt of a vehicle

Abstract

A locking device of a buckle of a seat belt for a vehicle includes a sector gear bracket configured to be integrally coupled to a rear tube coupled to a seat cushion frame, wherein the sector gear bracket has: an arc-shaped locking hole; and a sector gear arranged as an internal gear along the locking hole; a lever bracket located at one side of the sector gear bracket, wherein the lever bracket has a shaft portion configured to pass through the locking hole and the seat cushion frame and then integrally coupled to a lower end of the buckle; and a locking gear arranged as an external gear on the lever bracket.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a locking device for a buckle of a seat belt for a vehicle, and more particularly, to a locking device for a buckle of a seat belt for a vehicle that can couple the buckle to a seat cushion frame so as to be interlocked by adjusting a height of a seat to exhibit a supporting force against a tension force in a direction in which a load is applied to the buckle at the time of a collision and distribute the load applied to the buckle toward a vehicle body through a seat rail. BACKGROUND

[0002] Generally, a seat belt that limits an upper body of a passenger to secure the passenger in the case of an accident is installed in a vehicle, and each seat belt is configured so that the passenger wears the seat belt by coupling a tongue provided on a webbing to a buckle connected to a vehicle body.

[0003] A seat for a vehicle includes a seat frame serving as a frame, and includes a seat cushion frame and a seat back frame installed in a manner connected to a seat rail.

[0004] When the seat for a vehicle has a structure in which a height is vertically adjustable, the seat cushion frame and the seat rail are connected through a rotatable coupling, and thus, the seat cushion frame is vertically moved by rotation of the rotatable coupling so that the seat height is adjustable.

[0005] When a collision occurs in a state in which a passenger of a vehicle wears a seat belt, the upper body of the passenger is rapidly moved toward a front portion of the vehicle by an inertial force, and a lower end of the buckle is coupled to the seat rail and thus bears a load applied to the seat belt.

[0006] However, in a conventional structure in which the lower end of the buckle is coupled to the seat rail, when the seat is raised to adjust the height thereof, the buckle is hidden by the seat cushion, and thus, the passenger is inconvenient when coupling the tongue to the buckle.

[0007] The above description is provided to help understand the background of the present disclosure, and should not be construed as common technical knowledge known to those skilled in the art. SUMMARY

[0008] The present disclosure is made in view of the above-described problems, and an object of the present disclosure is to provide a locking device for a buckle of a seat belt for a vehicle that can couple the buckle to a seat cushion frame and connect the buckle to a seat rail so as to be vertically moved together with the seat when adjusting a height of the seat to exhibit a supporting force against a tension force in a direction in which a load is applied to the buckle at the time of a collision and distribute the load applied to the buckle toward a vehicle body through the seat rail, thereby being capable of improving durability of the buckle.

[0009] According to the present disclosure, the above and other objects can be achieved by providing a locking device for a buckle of a seat belt of a vehicle, the locking device including: a sector gear bracket configured to be integrally coupled to a rear tube coupled to a seat cushion frame, wherein the sector gear bracket has an arc-shaped locking hole and a sector gear arranged as an internal gear along the locking hole; a lever bracket located at one side of the sector gear bracket and configured to have a shaft portion passing through the locking hole and the seat cushion frame and then integrally coupled to a lower end of the buckle; and a locking gear arranged as an external gear on the lever bracket, located in the locking hole when the shaft portion is coupled to the buckle, and moved in a diagonal direction in the locking hole due to a load applied to the buckle, thereby engaging or disengaging with the sector gear.

[0010] The gusset bracket can be fixedly coupled to one surface of the seat cushion frame configured to face the sector gear bracket, and a guide hole configured such that the shaft portion passes therethrough can be integrally formed through the seat cushion frame and the gusset bracket.

[0011] The guide hole can be formed in a shape having a slit oriented in a diagonal direction in which the load is applied to the buckle.

[0012] The locking gear can engage with the sector gear when the shaft portion moves upward along the guide hole due to the load applied to the buckle, and the locking gear can disengage from the sector gear when the shaft portion moves downward along the guide hole.

[0013] A front end of the sector gear bracket can be rotatably coupled to a rail bracket by a hinge pin, the rail bracket can be fixedly coupled to a seat rail, and when a collision occurs, the load applied to the buckle can be transmitted to a vehicle body through the sector gear bracket, the hinge pin, the rail bracket, and the seat rail to be distributed.

[0014] The seat cushion frame and the seat rail can be connected by a plurality of rotatable links, the seat cushion frame can be vertically moved due to rotation of the rotatable links when the seat cushion frame and the rear tube are vertically moved with respect to the seat rail, thereby adjusting a height of the seat cushion frame, and the buckle connected to the seat cushion frame can be vertically moved with the seat cushion frame when the seat cushion frame is vertically moved.

[0015] A spring bracket can be integrally coupled thereto when the lower end of the buckle and the shaft portion of the lever bracket are coupled to each other, the locking device can further include a return spring installed such that one end of the return spring is supported by the spring bracket and the other end of the return spring is supported by the seat cushion frame, and the return spring can provide a spring force to the spring bracket to space the locking gear from the sector gear, thereby releasing engagement between the locking gear and the sector gear.

[0016] A bolt portion configured to protrude toward the rod support can be formed on the liner support, and a support hole through which the bolt portion passes can be formed in the rod support along the same diagonal direction as the guide hole. Since the rod nut is coupled to the bolt portion that has passed through the support hole, the rod support can be prevented from twisting when the shaft moves along the guide hole by a load applied to the buckle.

[0017] The buckle configured to form the seat belt can be connected to the seat cushion frame and seat rail via a locking device. Attached Figure Description

[0018] The above and other objects, features and advantages of this disclosure will become clearer from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0019] Figure 1 Part A and Figure 1 Part B is a view showing the state in which the seat belt buckle is coupled to the seat cushion support by a locking device in the structure of the height-adjustable seat according to the present disclosure, more specifically, Figure 1 Part A shows the seat in the lowered position, and Figure 1 Section B shows the seat in the raised position.

[0020] Figure 2 An exploded perspective view of the locking device of the buckle of a seat belt according to the present disclosure.

[0021] Figure 3 For assembly Figure 2 A perspective view of the locking device.

[0022] Figure 4 A view of the sector gear and locking gear according to this disclosure is shown.

[0023] Figure 5 This is a view showing the state in which the locking gear and the sector gear are spaced apart by the spring force of the return spring according to this disclosure.

[0024] Figure 6 A view showing the engagement of the locking gear and the sector gear by moving the lever support in the direction of applying load to the buckle in the event of a collision; and

[0025] Figure 7 and Figure 8 An exploded perspective view and a perspective view are provided to show the state in which the bolt portion formed on the liner bracket according to this disclosure is coupled to the rod nut after passing through the bracket hole formed in the rod bracket. Detailed Implementation

[0026] The specific structural or functional description in the embodiments of the disclosure set forth in the following description will be exemplarily given to describe the embodiments of the disclosure. However, the disclosure can be implemented in many alternative forms, and should not be interpreted as being limited to the embodiments set forth herein.

[0027] The embodiments of the disclosure can be variously modified and changed, and therefore, specific embodiments of the disclosure will be shown in the accompanying drawings, and described in detail in the following description of the embodiments of the disclosure. However, it should be understood that the embodiments of the disclosure are provided only to fully disclose the disclosure, and to encompass modifications, equivalents, or alternatives falling within the scope and technical spirit of the disclosure.

[0028] In the following description of the embodiments, terms such as "first" and "second" are used only to describe various elements, and the elements should not be construed as being limited by the terms. The terms are used only to distinguish one element from other elements. For example, the first element described below can be referred to as a second element without departing from the scope of the disclosure, and similarly, the second element described below can be referred to as a first element.

[0029] When an element or layer is referred to as "connected to" or "coupled to" another element or layer, it can be directly connected to or directly coupled to the other element or layer, or there can be an intermediate element or layer. In contrast, when an element or layer is referred to as "directly connected to" or "directly coupled to" another element or layer, there can be no intermediate element or layer. Other words used to describe the relationship between elements should be explained in a similar manner, for example, "between... and... " and "directly between... and... ", "adjacent" and "directly adjacent", etc.

[0030] The terms used herein are only for the purpose of describing particular embodiments and are not intended to be limiting. As used herein, the singular form can also be intended to include the plural form, unless the context clearly indicates otherwise. The terms "comprise", "contain", "include" and "have" are inclusive, thus specifying the presence of the stated features, integers, steps, operations, elements, components and / or combinations thereof, but not precluding the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0031] Unless otherwise defined, all terms used in the following description (including technical and scientific terms) have the same meaning as that which is commonly understood by one of ordinary skill in the art. Terms defined in commonly used dictionaries are to be construed as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted to have an ideal or overly formal meaning unless expressly so defined in the specification.

[0032] The controller according to one exemplary embodiment of the present disclosure can be implemented by an algorithm configured to control the operation of various components of the vehicle or a non-volatile memory (not shown) configured to store data related to software commands for reproducing the algorithm and a processor (not shown) configured to perform the operations to be described below using the data stored in the corresponding memory. Here, the memory and the processor can be implemented as separate chips. Alternatively, the memory and the processor can be implemented as a single integrated chip. Alternatively, more than one processor can be provided.

[0033] Hereinafter, a locking device of a buckle of a seat belt for a vehicle according to one exemplary embodiment of the present disclosure will be described with reference to the accompanying drawings.

[0034] As shown in parts A and B of FIG. 1, Figure 1 A seat for a vehicle includes a seat frame 10 serving as a frame, which includes a seat cushion frame 11 and a seat back frame 12, and the seat back frame 12 exhibits a reclining function in which the seat back frame 12 rotates forward and rearward with respect to the seat cushion frame 11 to adjust the angle thereof.

[0035] A front tube 13 and a rear tube 14 are coupled to the front and rear ends of the seat cushion frame 11 to restrain the portions of the front and rear ends of the seat cushion frame 11 of the vehicle, which are laterally spaced apart from each other.

[0036] A fixed rail 21 constituting a seat rail 20 is fixed to the floor of the vehicle to extend in the front-rear direction, a movable rail 22 moving forward and rearward along the fixed rail 21 is coupled to the fixed rail 21, and the movable rail 22 is rotatably connected to the seat cushion frame 11 through a plurality of rotatable couplings 30.

[0037] Accordingly, when the rotatable couplings 30 are rotated by external power, the seat cushion frame 11 moves vertically with respect to the seat rail 20, so that the height of the seat of the vehicle can be adjusted in the vertical direction.

[0038] Figure 1 Part A of FIG. 2 shows a downward state in which the seat frame 10 is lowered, and Figure 1 Part B of FIG. 2 shows an upward state in which the seat frame 10 is raised.

[0039] One embodiment of the present disclosure is configured such that a buckle 40 constituting a seat belt is located on the side surface of the seat cushion frame 11 and coupled to the seat cushion frame 11, so that the buckle 40 moves together with the seat when the height of the seat is adjusted and thus is prevented from being hidden by the seat cushion, so that the inconvenience when a passenger couples a tongue to the buckle 40 can be alleviated.

[0040] Further, when a collision occurs in a state in which a seat belt is worn by a passenger of a vehicle, the upper body of the passenger is rapidly moved toward a front portion of the vehicle by an inertial force, at this time, a great load (tension of the webbing) is applied to the buckle 40, and, in one embodiment of the disclosure, a support force against the tension applied to the buckle 40 in the direction is exhibited by the engagement structure of the gear, thus it is possible to maintain the firm coupling structure of the buckle 40 and thereby improve the durability of the buckle 40.

[0041] In addition, one embodiment of the disclosure is configured such that the buckle 40 is coupled to the seat cushion frame 11 and is also connected to the seat rail 20, thereby it is possible to distribute the load applied to the buckle 40 toward the vehicle body through the seat rail 20 when a collision occurs, and to improve the durability of the buckle 40.

[0042] To achieve the above-mentioned effects, as Figure 1 Part A and Part B, Figure 2 , Figure 3 , Figure 4 , Figures 5 to 6 indicated, the locking device according to one exemplary embodiment of the disclosure includes: a sector gear bracket 100 configured to be integrally coupled to a rear tube 14 coupled to a seat cushion frame 11, such that the rear tube 14 passes through the sector gear bracket 100 and has an arc-shaped locking hole 110 formed therein and a sector gear 120 provided in the form of an internal gear formed along the outer periphery of the locking hole 110; a lever bracket 200 located at one side of the sector gear bracket 100 and configured to have a shaft portion 210 passing through the locking hole 110 and the seat cushion frame 11 and then integrally coupled to the lower end of a buckle 40; and a locking gear 300 provided in the form of an external gear on a surface of the lever bracket 200 from which the shaft portion 210 protrudes, located in the locking hole 110 when the shaft portion 210 is coupled to the buckle 40, and moved in a diagonal direction in the locking hole 110 due to a load applied to the buckle 40, thereby engaging or disengaging with the sector gear 120.

[0043] The rear tube 14 sequentially passes through the sector gear bracket 100 and the seat cushion frame 11, and the rear tube 14 is coupled to each of the sector gear bracket 100 and the seat cushion frame 11 by welding, thereby being integrated with the sector gear bracket 100 and the seat cushion frame 11.

[0044] The gusset bracket 400 is fixedly coupled to one surface of the seat cushion frame 11 facing the sector gear bracket 100 by welding, and a guide hole 500 is integrally formed through the seat cushion frame 11 and the gusset bracket 400.

[0045] The bushing can be inserted into the guide hole 500, and the shaft portion 210 of the lever bracket 200 can pass through the guide hole 500.

[0046] The guide hole 500 can have a slit shape oriented in a diagonal direction (indicated by an arrow F1) in which a load is applied to the buckle 40. Figure 6

[0047] The front end of the sector gear bracket 100 is rotatably coupled to the rail bracket 23 through the hinge pin 600, and the rail bracket 23 is fixedly coupled to the movable rail 22 of the seat rail 20.

[0048] When the rotatable coupling 30 is rotated and the rear tube 14 is moved up and down to adjust the height of the seat, the sector gear bracket 100 rotates with respect to the rail bracket 23 about the hinge pin 600.

[0049] The buckle shaft 41 protrudes from the lower end of the buckle 40, and the buckle shaft 41 is formed in the structure of a bolt having a thread formed on the outer circumferential surface thereof.

[0050] The shaft portion 210 of the lever bracket 200 is formed in a tube structure, and threads extending in the length direction of the shaft portion 210 are formed on both the inner and outer circumferential surfaces of the shaft portion 210.

[0051] The buckle shaft 41 of the buckle 40 passes through the buckle nut 700, the shaft portion 210 of the lever bracket 200 passes through the locking hole 110 and the guide hole 500 of the sector gear bracket 100, the buckle shaft 41 is inserted into the shaft portion 210 and coupled to the shaft portion 210 by thread engagement, the shaft portion 210 is inserted into the buckle nut 700 and coupled to the buckle nut 700 by thread engagement, and thus the buckle 40, the lever bracket 200, and the locking gear 300 provided on the lever bracket 200 are coupled to each other to form one body.

[0052] In addition, in the present disclosure, when the buckle shaft 41 of the buckle 40 and the shaft portion 210 of the lever bracket 200 are coupled to each other, the spring bracket 800 is integrally coupled thereto, and the locking device according to the present disclosure further includes a return spring 900 mounted such that one end of the return spring 900 is supported by the spring bracket 800 and the other end of the return spring 900 is supported by the seat cushion frame 11.

[0053] The shaft portion 210 of the lever bracket 200 passing through the guide hole 500 passes through the spring bracket 800 and is coupled to the buckle shaft 41 and the buckle nut 700 by thread engagement, and in this case, the spring bracket 800 contacts the protrusion 42 protruding from the lower portion of the buckle shaft 41, thereby coupling the buckle 40 and the spring bracket 800 to each other to form one body.

[0054] ​Finally, the buckle 40, the return spring 900, the buckle nut 700, the spring bracket 800, the lever bracket 200, and the locking gear 300 are integrally coupled to each other to form one body, and thus, when the buckle 40 moves by a load applied to the buckle 40, the return spring 900, the buckle nut 700, the spring bracket 800, the lever bracket 200, and the locking gear 300 all move together.

[0055] As shown in FIG. 1, the locking device according to the present disclosure is configured such that the buckle 40 constituting the seat belt is positioned on the side surface of the seat cushion frame 11 and coupled to the seat cushion frame 11, and thus, when the seat cushion frame 11 is vertically moved to adjust the height of the seat, the buckle 40 is also moved, thereby being able to prevent the buckle 40 from being hidden by the seat cushion regardless of the adjusted height of the seat, and thereby allowing the passenger to easily couple the tongue to the buckle 40. Figure 5 As shown in FIG. 1, the locking device according to the present disclosure is configured such that the buckle 40 constituting the seat belt is positioned on the side surface of the seat cushion frame 11 and coupled to the seat cushion frame 11, and thus, when the seat cushion frame 11 is vertically moved to adjust the height of the seat, the buckle 40 is also moved, thereby being able to prevent the buckle 40 from being hidden by the seat cushion regardless of the adjusted height of the seat, and thereby allowing the passenger to easily couple the tongue to the buckle 40.

[0056] Figure 7 As shown in FIG. 1, the locking device according to the present disclosure is configured such that the buckle 40 constituting the seat belt is positioned on the side surface of the seat cushion frame 11 and coupled to the seat cushion frame 11, and thus, when the seat cushion frame 11 is vertically moved to adjust the height of the seat, the buckle 40 is also moved, thereby being able to prevent the buckle 40 from being hidden by the seat cushion regardless of the adjusted height of the seat, and thereby allowing the passenger to easily couple the tongue to the buckle 40. Figure 8 As shown in FIG. 1, the locking device according to the present disclosure is configured such that the buckle 40 constituting the seat belt is positioned on the side surface of the seat cushion frame 11 and coupled to the seat cushion frame 11, and thus, when the seat cushion frame 11 is vertically moved to adjust the height of the seat, the buckle 40 is also moved, thereby being able to prevent the buckle 40 from being hidden by the seat cushion regardless of the adjusted height of the seat, and thereby allowing the passenger to easily couple the tongue to the buckle 40.

[0057] As shown in FIG. 1, the locking device according to the present disclosure is configured such that the buckle 40 constituting the seat belt is positioned on the side surface of the seat cushion frame 11 and coupled to the seat cushion frame 11, and thus, when the seat cushion frame 11 is vertically moved to adjust the height of the seat, the buckle 40 is also moved, thereby being able to prevent the buckle 40 from being hidden by the seat cushion regardless of the adjusted height of the seat, and thereby allowing the passenger to easily couple the tongue to the buckle 40.

[0058] As shown in FIG. 1, the locking device according to the present disclosure is configured such that the buckle 40 constituting the seat belt is positioned on the side surface of the seat cushion frame 11 and coupled to the seat cushion frame 11, and thus, when the seat cushion frame 11 is vertically moved to adjust the height of the seat, the buckle 40 is also moved, thereby being able to prevent the buckle 40 from being hidden by the seat cushion regardless of the adjusted height of the seat, and thereby allowing the passenger to easily couple the tongue to the buckle 40.

[0059] As shown in FIG. 1, the locking device according to the present disclosure is configured such that the buckle 40 constituting the seat belt is positioned on the side surface of the seat cushion frame 11 and coupled to the seat cushion frame 11, and thus, when the seat cushion frame 11 is vertically moved to adjust the height of the seat, the buckle 40 is also moved, thereby being able to prevent the buckle 40 from being hidden by the seat cushion regardless of the adjusted height of the seat, and thereby allowing the passenger to easily couple the tongue to the buckle 40. Figure 6 As shown in FIG. 1, the locking device according to the present disclosure is configured such that the buckle 40 constituting the seat belt is positioned on the side surface of the seat cushion frame 11 and coupled to the seat cushion frame 11, and thus, when the seat cushion frame 11 is vertically moved to adjust the height of the seat, the buckle 40 is also moved, thereby being able to prevent the buckle 40 from being hidden by the seat cushion regardless of the adjusted height of the seat, and thereby allowing the passenger to easily couple the tongue to the buckle 40.

[0060] As shown in FIG. 1, the locking device according to the present disclosure is configured such that the buckle 40 constituting the seat belt is positioned on the side surface of the seat cushion frame 11 and coupled to the seat cushion frame 11, and thus, when the seat cushion frame 11 is vertically moved to adjust the height of the seat, the buckle 40 is also moved, thereby being able to prevent the buckle 40 from being hidden by the seat cushion regardless of the adjusted height of the seat, and thereby allowing the passenger to easily couple the tongue to the buckle 40. Figure 6As shown, when a load (indicated by arrow F1) is applied to the buckle 40, the shaft portion 210 of the lever bracket 200 connected to the buckle 40 is moved to the upper portion of the guide hole 500 near the sector gear 120 (i.e., moved in the direction in which the load is applied to the buckle 40), and as a result of the upward movement of the lever bracket 200, the locking gear 300 provided on the lever bracket 200 is engaged with the sector gear 120, and thus exhibits a support force, thereby enabling the secure coupling structure of the buckle 40 to be maintained and improving the durability of the buckle 40.

[0061] Thereafter, as shown in FIG. 4B, when the load applied to the buckle 40 is removed, the shaft portion 210 of the lever bracket 200 is moved downward in the guide hole 500, and thus moves away from the sector gear 120 by the elastic force of the return spring 900, and as a result of the downward movement of the lever bracket 200, the locking gear 300 is disengaged from the sector gear 120. Figure 5

[0062] In addition, according to one embodiment of the present disclosure, the buckle 40 is connected to the seat cushion frame 11, the seat cushion frame 11 is connected to the sector gear bracket 100 through the rear tube 14, the sector gear bracket 100 is connected to the seat rail 20 through the hinge pin 600 and the rail bracket 23, and thus, when a collision occurs and a large load is thus applied to the buckle 40 (in the direction of arrow F1) due to the tension of the webbing, the load applied to the buckle 40 (in the direction of arrow F1) can be ultimately distributed toward the vehicle body through the seat rail 20, thereby improving the durability of the buckle 40.

[0063] As is apparent from the above description, the locking device of the buckle of the seat belt for a vehicle according to the present disclosure is configured such that the buckle constituting the seat belt is positioned on the side surface of the seat cushion frame and coupled to the seat cushion frame, and thus, when the seat cushion frame is moved vertically to adjust the height of the seat, the buckle is also moved, thereby enabling the buckle to be prevented from being hidden by the seat cushion regardless of the adjusted height of the seat, and thus allowing the passenger to easily couple the tongue to the buckle.

[0064] In addition, when a collision occurs in a state in which the seat belt is worn by a passenger of a vehicle and a large load is thus applied to the buckle due to the tension of the webbing of the seat belt, the shaft portion of the lever bracket connected to the buckle is moved to the upper portion of the guide hole near the sector gear, and as a result of the upward movement of the lever bracket, the locking gear provided on the lever bracket is engaged with the sector gear, and thus exhibits a support force, thereby enabling the secure coupling structure of the buckle to be maintained and improving the durability of the buckle.

[0065] ​In addition, according to one embodiment of the present disclosure, the buckle is connected to a seat cushion frame, the seat cushion frame is connected to a sector gear bracket through a rear tube, the sector gear bracket is connected to a seat rail through a hinge pin and a rail bracket, and thus, when a collision occurs and a large load is thereby applied to the buckle, the load applied to the buckle can finally be distributed toward a vehicle body through the seat rail, so that durability of the buckle can be improved.

[0066] Although the exemplary embodiments of the present disclosure are disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the present disclosure disclosed in the following claims.

Claims

1. A locking device of a buckle of a seat belt for a vehicle, comprising: a sector gear bracket configured to be integrally coupled to a rear tube coupled to a seat cushion frame, wherein the sector gear bracket has: an arc-shaped locking hole; and a sector gear arranged as an internal gear along the locking hole; a lever bracket located at one side of the sector gear bracket, wherein the lever bracket has a shaft portion configured to pass through the locking hole and the seat cushion frame and then integrally coupled to a lower end of the buckle; and a locking gear arranged as an external gear on an outer surface of the lever bracket, wherein, when the shaft portion is coupled to the buckle, the locking gear is configured to be arranged in the locking hole and to move in a diagonal direction in the locking hole to engage or disengage with the sector gear due to a load applied to the buckle, wherein the locking device further comprises: a gusset bracket fixedly coupled to one surface of the seat cushion frame arranged to face the sector gear bracket; and a guide hole through which the shaft portion passes, the guide hole extending through the seat cushion frame and the gusset bracket, wherein the guide hole has a shape of a slit oriented in a diagonal direction to which the load is applied to the buckle.

2. The locking device of claim 1, wherein, when the shaft portion moves upward along the guide hole due to the load applied to the buckle, the locking gear engages with the sector gear, and wherein, when the shaft portion moves downward along the guide hole, the locking gear disengages with the sector gear. 3.The locking device of claim 1, further comprising: a rail bracket to which a front end of the sector gear bracket is rotatably coupled by a hinge pin; and a seat rail to which the rail bracket is fixedly coupled, wherein, when a collision occurs, the load applied to the buckle is transmitted to a vehicle body through the sector gear bracket, the hinge pin, the rail bracket, and the seat rail. the seat cushion frame and the seat rail are connected by a plurality of rotatable links, 4. The locking device of claim 3, wherein, wherein, when the seat cushion frame and the rear tube are moved vertically with respect to the seat rail, the seat cushion frame is moved vertically due to rotation of the rotatable links, thereby adjusting a height of the seat cushion frame, and wherein, when the seat cushion frame is moved vertically, the buckle connected to the seat cushion frame is moved vertically with the seat cushion frame. when the lower end of the buckle and the shaft portion of the lever bracket are coupled to each other, a spring bracket is integrally coupled with the buckle and the lever bracket, 5. The locking device of claim 1, wherein, wherein the locking device further comprises a return spring, one end of which is supported by the spring bracket and the other end of which is supported by the seat cushion frame, and wherein the return spring is configured to transmit a spring force to the spring bracket such that the locking gear is spaced apart from the sector gear to release engagement between the locking gear and the sector gear. ​ 6. The locking device according to claim 1, further comprising: a bolt portion configured to protrude toward the rod bracket on the back pad bracket; and a bracket hole through which the bolt portion passes, the bracket hole being defined in the rod bracket in the same diagonal direction as the guide hole, wherein a rod nut is coupled to the bolt portion that has passed through the bracket hole, such that when the shaft portion moves along the guide hole by the load applied to the buckle, twisting of the rod bracket is prevented.

7. The locking device of claim 3, wherein, The buckle of the seat belt is connected to the seat cushion frame and the seat rail by the locking device.

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