Buckle device

Abstract

To provide a buckle device capable of reliably preventing release of engagement of a tongue plate by inertial force irrespective of the direction of the inertial force.SOLUTION: A buckle device includes a buckle body, an actuation member 3, and an inertial member 9. The inertial member 9 is supported so as to rotate around a rotation center shaft 90 extending in a width direction of a tongue plate 15. The actuation member 3 can come in contact with a first lever 94 of the inertial member 9 at a first contact part 31, and come in contact with a second lever 93 of the inertial member 9 at a second contact part 32 in an engagement state of the tongue plate 25. The first lever 94 imparts first pressing force Fb in a direction B greater than first inertial force FA to the first contact part 31 when the first inertial force FA in a direction A acts on the actuation member 3. The second lever 93 imparts second pressing force Fa in the direction A smaller than second inertial force FB to the second contact part 32 when the second inertial force FB acts on the actuation member 3.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present invention relates to a buckle device which is a component of a seat belt device for a vehicle.

Background Art

[0002] Conventionally, there has been known a buckle device into which a tongue plate provided on a vehicle seat belt (also referred to as a webbing) is inserted and which is detachably engaged with the inserted tongue plate. For example, Patent Document 1 discloses a buckle device 100 that prevents the engagement of a tongue plate 110 from being released by inertial force, as shown in FIG. 15(a).

[0003] Specifically, in the buckle device 100 disclosed in Patent Document 1, a mechanical assembly 120 is disposed in a hollow buckle body (not shown). The mechanical assembly 120 includes a release button 130 that receives a release operation for releasing the engagement of the tongue plate 110 and an inertial member 140.

[0004] The inertial member 140 is rotatable about a rotation center axis 150. As shown in FIG. 15(b), a slot 131 that opens in the thickness direction of the tongue plate 110 is provided in a portion of the release button 130 that is located between the rotation center axis 150 of the inertial member 140 and the tongue plate 110. The inertial member 140 has a lever 141 that protrudes from the rotation center axis 150 toward the slot 131, and the tip of the lever 141 is inserted into the slot 131. The center of gravity of the inertial member 140 is set on the side opposite to the lever 141 with respect to the rotation center axis 150.

[0005] In the engaged state of the tongue plate 110, when an acceleration in the B direction, which is the direction opposite to the A direction (the insertion direction of the tongue plate 110) occurs in the buckle device 100, if an inertial force in the A direction acts on the release button 130, the inertial force in the A direction also acts on the inertial member 140, and a torque around the rotation center axis 150 is generated in the inertial member 140. For this reason, the release button 130 is pressed in the B direction by the lever 141 of the inertial member 140. By configuring the inertial member 140 such that the pressing force at this time is greater than the inertial force of the release button 130, the operation of the release button 130 when an inertial force in the A direction acts on the release button 130 is blocked by the inertial member 140.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in the buckle device 100 of Patent Document 1, even when an inertial force in the B direction acts on the release button 130, the lever 141 of the inertial member 140 presses the release button 130 in the A direction with a pressing force greater than the inertial force of the release button 130. Therefore, there is a possibility that the release button 130 may be actuated by the inertial member 140.

[0008] Therefore, an object of the present invention is to provide a buckle device that can surely prevent the release of the engagement of the tongue plate due to inertial force regardless of the direction of the inertial force.

Means for Solving the Problems

[0009] The present invention relates to a buckle device into which a tongue plate provided on a vehicle seat belt is inserted and which detachably engages with the inserted tongue plate, the buckle device including a hollow buckle body, an operating member slidably supported in the buckle body in the insertion direction of the tongue plate and operating in response to a release operation for releasing the engagement of the tongue plate, and an inertial member rotatably supported in the buckle body about a rotation center axis extending in the width direction of the tongue plate. The inertial member has a main body portion through which the rotation center axis passes, and a first lever and a second lever protruding from the main body portion in a direction away from the rotation center axis and arranged at a predetermined interval in the insertion direction of the tongue plate when viewed from the extending direction of the rotation center axis. The first lever is located deeper inside the buckle body in the insertion direction of the tongue plate than the second lever. The operating member can contact the first lever at a first contact portion and the second lever at a second contact portion in the engaged state of the tongue plate. The first contact portion and the second contact portion are located between the first lever and the second lever in the insertion direction of the tongue plate in the engaged state of the tongue plate, and move in a direction away from between the first lever and the second lever as the inertial member rotates when releasing the engagement of the tongue plate. The first lever applies, to the first contact portion, a first pressing force in a direction opposite to the insertion direction of the tongue plate and greater than the first inertial force when a first inertial force in the insertion direction of the tongue plate acts on the operating member in the engaged state of the tongue plate. The second lever applies, to the second contact portion, a second pressing force in the insertion direction of the tongue plate and smaller than the second inertial force when a second inertial force in a direction opposite to the insertion direction of the tongue plate acts on the operating member in the engaged state of the tongue plate. Provided is a buckle device characterized by the above.

[0010] According to the above configuration, when a first inertial force in the insertion direction of the tongue plate acts on the operating member, a first pressing force greater than the first inertial force and in the opposite direction to the first inertial force is applied from the first lever of the inertial member to the operating member, so the operation of the operating member is blocked. Conversely, when a second inertial force in the direction opposite to the insertion direction of the tongue plate acts on the operating member, a second pressing force in the direction opposite to the second inertial force is applied from the second lever of the inertial member to the operating member. However, since the second pressing force is smaller than the second inertial force, the operating member is not actuated in the insertion direction of the tongue plate by the second lever. Therefore, regardless of the direction of the inertial force, it is possible to reliably prevent the release of the engagement of the tongue plate due to the inertial force. Moreover, since the first contact portion and the first lever for the first inertial force and the second contact portion and the second lever for the second inertial force are provided separately, the degree of freedom in their design is high.

[0011] In the thickness direction of the tongue plate, the first distance from the rotation center axis of the inertial member to the contact point between the first contact portion and the first lever may be smaller than the second distance from the rotation center axis of the inertial member to the contact point between the second contact portion and the second lever. Alternatively, in the engaged state of the tongue plate, the first angle formed by the insertion direction of the tongue plate and the surface of the first contact portion side of the first lever may be larger than the second angle formed by the direction opposite to the insertion direction of the tongue plate and the surface of the second contact portion side of the second lever. According to these configurations, a difference can be provided between the first pressing force and the second pressing force with a relatively simple configuration.

[0012] The above buckle device includes a release button that receives the release operation, an engaging member that engages with the tongue plate inserted into the buckle body, and when the engaging member engages with the tongue plate, it operates in the locking direction to suppress the release of the engagement of the engaging member, and when the release button operates to the back side of the buckle body, it operates in the direction opposite to the locking direction to allow the release of the engagement of the engaging member. The operating member may be at least one of the release button or the locking member. According to this configuration, since the buckle device usually includes a release button and a locking member, the first contact portion and the second contact portion can be set without adding parts.

[0013] The operating member may be both the release button and the locking member, the first contact portion may be provided on the locking member, and the second contact portion may be provided on the release button. According to this configuration, the shapes of the release button and the locking member can be simplified, making them easy to manufacture, and the setting can be easily made in consideration of the strength and the shapes of other members.

[0014] The release button is biased in a direction opposite to the insertion direction of the tongue plate. When the tongue plate is not inserted into the buckle body, the first lever may contact the locking member, and the second lever may contact the release button. According to this configuration, in the non-engaged state of the tongue plate, the movement of the release button and the rotation of the inertial member are blocked, so that abnormal noise due to rattling of the release button and the inertial member can be prevented.

[0015] In the engaged state of the tongue plate, the first lever and the second lever the above-mentioned may be located on the side opposite to the tongue plate with respect to the rotation center axis. According to this configuration, the shapes and sizes of the first lever, the second lever, the first contact portion, and the second contact portion are less likely to be restricted by space due to the tongue plate.

Effects of the Invention

[0016] According to the present invention, regardless of the direction of the inertial force, it is possible to reliably prevent the disengagement of the tongue plate due to the inertial force.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

DETAILED DESCRIPTION OF THE INVENTION

[0018] Fig. 1(a) shows a buckle device 1 according to an embodiment of the present invention. The buckle device 1 is provided on a seat belt of a vehicle and is configured to receive a tongue plate 15 shown in Fig. 1(b) and engage with the inserted tongue plate 15 detachably.

[0019] Specifically, the buckle device 1 includes a hollow buckle body 2 and a mechanical assembly 10 shown in Fig. 2 disposed within the buckle body 2. That is, the buckle body 2 serves as a cover for housing the mechanical assembly 10.

[0020] Hereinafter, for convenience of explanation, the insertion direction of the tongue plate 15 is defined as the rear, and the direction opposite to the insertion direction of the tongue plate 15 is defined as the front. Also, one of the thickness directions of the tongue plate 15 is defined as the upper side, the other as the lower side, and the width direction of the tongue plate 15 is defined as the left - right direction.

[0021] The mechanical assembly 10 includes a frame 6 and an operating member 3. The frame 6 has a U - shaped groove - like shape that extends in the front - rear direction while opening upward. The operating member 3 is supported by the frame 6 so as to be slidable in the front - rear direction. The operating member 3 operates in response to a release operation that releases the engagement of the tongue plate 15.

[0022] In the present embodiment, the operating member 3 is both a release button 4 and a locking member 5 (see FIG. 3). FIG. 3 is a perspective view of the mechanical assembly 10 with the release button 4 removed in the engaged state of the tongue plate 15 (the tongue plate 15 is omitted). The release button 4 receives a release operation. The locking member 5 is for maintaining the engaged state of the tongue plate 15 shown in FIG. 9(c).

[0023] As shown in FIG. 1(a), the buckle body 2 has a substantially rectangular front opening that opens forward and is long in the left - right direction. The release button 4 closes the upper portion of the front opening. The portion of the buckle body 2 located below the front opening becomes a tongue plate guide portion 21 that slopes obliquely upward toward the rear and then becomes parallel to the front - rear direction. A tongue plate insertion opening 20 is formed between the tongue plate guide portion 21 and the release button 4.

[0024] As shown in FIGS. 3 and 4, the mechanical assembly 10 includes an ejector 7, an engaging member 8, and an inertial member 9 in addition to the frame 6 and the actuating member 3. The ejector 7 abuts against a tongue plate 15 inserted into the buckle body 2 through a tongue plate insertion port 20. The engaging member 8 engages with the tongue plate 15 inserted into the buckle body 2 through the tongue plate insertion port 20. The inertial member 9 is for preventing the actuating member 3 from operating due to inertial force when the tongue plate 15 is in an engaged state.

[0025] More specifically, as shown in FIG. 4, the frame 6 has a bottom wall 61 that continuously forms a tongue plate guide surface with the tongue plate guide portion 21 of the buckle body 2, and a pair of side walls 62 that rise from both left and right end portions of the bottom wall 61.

[0026] A holding hole 68 extending in the front-rear direction is formed in the bottom wall 61. The ejector 7 is inserted into the holding hole 68 so as to be slidable in the front-rear direction. The ejector 7 is biased forward by a spring 11.

[0027] The ejector 7 is provided with a pair of left and right bosses 71 that project upward. In a non-engaged state of the tongue plate 15 (for example, a state where the tongue plate 15 is not inserted into the buckle body 2), as shown in FIG. 8, the bosses 71 press a protruding portion 45 (to be described later) of the release button 4 by the biasing force of the spring 11.

[0028] A first recess 66 that opens forward is formed at the front end portion of each side wall 62, and a second recess 63 that opens upward is formed at the central portion of each side wall 62. Further, a third recess 67 that depresses downward from the center of the first recess 66 is formed in each side wall 62. Furthermore, a first slit 65 and a second slit 64 that extend in the front-rear direction are formed in each side wall 62, behind the first recess 66 and in front of the second recess 63. The second slit 64 is located below the first slit 65. When viewed from the vertical direction, the rear portion of the first slit 65 overlaps with the front portion of the second slit 64.

[0029] In this embodiment, the engaging member 8 includes a metal part 8A and a resin part 8B that fit into each other. However, the configuration of the engaging member 8 is not limited to this and can be changed as appropriate. The metal part 8A is formed by bending a metal plate of a predetermined shape. Specifically, the metal part 8A includes a base part 81 extending in the front-rear direction, a hook part 82 hanging down from the front end part of the base part 81, and a pair of left and right leg parts 84 hanging down from the rear end part of the base part 81. A through hole for fitting with the resin part 8B is provided in the base part 81. The resin part 8B includes a first restricting part 86 located on the front end part of the base part 81 and a spring receiving part 87 located on the rear end part of the base part 81.

[0030] Furthermore, the metal part 8A includes a pair of fulcrum parts 83 projecting left and right from the rear end part of the base part 81, and a pair of second restricting parts 85 projecting left and right from the front end part of the base part 81 and then projecting forward. When the fulcrum parts 83 are inserted into the second recessed parts 63 formed in the side wall 62 of the frame 6, the engaging member 8 is supported by the frame 6 so as to be swingable with the fulcrum parts 83 as fulcrums.

[0031] The lock member 5 moves between the standby position shown in FIG. 8 and the lock position shown in FIG. 9(c). When the engaging member 8 engages with the tongue plate 15, the lock member 5 operates from the standby position in the locking direction (forward in this embodiment) to suppress the release of the engagement of the engaging member 8. When the release button 4 operates backward toward the inner side of the buckle body 2, the lock member 5 operates from the lock position in the direction opposite to the locking direction (backward in this embodiment) to allow the release of the engagement of the engaging member 8.

[0032] More specifically, as shown in FIGS. 4 and 7, the lock member 5 includes a resin part having a base part 51 extending in the left-right direction, and a metal lock bar 13 inserted into a through hole 54 penetrating the base part 51 in the left-right direction. A pair of arm parts 52 extending forward from both end parts of the base part 51 are provided on the base part 51. The front parts of the arm parts 52 are connected by a bridging part 55 extending in the left-right direction. Both end parts of the lock bar 13 project from the base part 51.

[0033] In addition, a pair of bosses 53 protruding outward are respectively provided at the tips of the pair of arm portions 52. Both ends of the lock bar 13 are inserted into the first slits 65 formed in the side wall 62 of the frame 6, and the bosses 53 are inserted into the first recesses 66 formed in the side wall 62, so that the lock member 5 is supported by the frame 6 so as to be slidable in the front-rear direction.

[0034] A spring 12 is disposed between the base 51 of the lock member 5 and the spring receiving portion 87 of the engaging member 8. Note that the spring 12 is omitted in FIGS. 2 and 3 for simplicity of the drawing. The spring 12 biases the engaging member 8 to swing upward (the hook portion 82 moves upward) and biases the lock member 5 forward.

[0035] In addition, the lock member 5 is provided with a first restricting portion 56 protruding downward from the center of the base 51 and a pair of second restricting portions 57 protruding downward from both ends of the base 51. As shown in FIG. 8, in the non-engaged state of the tongue plate 15, the front end portion of the base 51 contacts the first restricting portion 86 of the engaging member 8 from the rear. Thereby, the lock member 5 is maintained at the standby position.

[0036] In the state from FIG. 9(a) to FIG. 9(b) during the engagement of the tongue plate 15, until the engaging member 8 swings downward and the first restricting portion 86 of the engaging member 8 is positioned below the first restricting portion 56 of the lock member 5, the first restricting portion 56 moves forward while contacting the first restricting portion 86 of the engaging member 8 that swings downward. Then, when the state shown in FIG. 9(b) is reached where the first restricting portion 86 of the engaging member 8 is positioned below the first restricting portion 56 of the lock member 5, the second restricting portion 57 of the lock member 5 moves forward while sliding on the second restricting portion 85 of the engaging member 8. In the engaged state of the tongue plate 15 shown in FIG. 9(c), the second restricting portion 57 contacts the second restricting portion 85 of the engaging member 8. Thereby, the state where the engaging member 8 swings downward is maintained.

[0037] As shown in FIGS. 5(a) and 5(b), the release button 4 includes a front wall 41 that is long in the left - right direction and a pair of side walls 42 that extend rearward from the front wall 41 and sandwich both side walls 62 of the frame 6. The upper ends of the rear portions of the side walls 42 are connected by a bridging portion 43 that extends in the left - right direction.

[0038] A projecting portion 44 that projects forward is provided at the central portion of the bridging portion 43. This projecting portion 44 is connected to the central portion of the upper end of the front wall 41 by a pair of left - right ribs 48. An opening 49 into which a second lever 93 of the inertia member 9 described later is inserted is formed between the ribs 48. A projecting portion 45 that projects rearward is provided at the central portion of the lower end of the front wall 41.

[0039] At the rear ends of both side walls 42, mounting portions 46 each having a claw that hangs downward and projects inward at the tip are provided. When the bridging portion 43 is placed on the upper end surfaces of both side walls 62 of the frame 6 and the claws of both mounting portions 46 are inserted into second slits 64 formed in the side walls 62, the release button 4 is supported by the frame 6 so as to be slidable in the front - rear direction.

[0040] As shown in FIG. 3, the length of the above - described lock bar 13 is set to be longer than the width of the frame 6, and both ends of the lock bar 13 project outward from the side walls 62 of the frame 6. As shown in FIGS. 5(a) and 5(b), on the inner surface of each side wall 42 of the release button 4, a groove 47 is formed in the front - rear direction into which the end of the lock bar 13 is inserted, and the width of the groove 47 in the front - rear direction is wider than the width of the lock bar 13. In the non - engaged state of the tongue plate 15, the end of the lock bar 13 is positioned with a gap near the rear - side surface of the groove 47, and in the engaged state of the tongue plate 15, the end of the lock bar 13 contacts the front - side surface of the groove 47.

[0041] As shown in FIG. 8, the inertial member 9 is supported by the frame 6 so as to be rotatable about a rotation center axis 90 extending in the left-right direction. Specifically, as shown in FIGS. 6(a) and 6(b), the inertial member 9 includes a main body portion 91 through which the rotation center axis 90 passes, and two first levers 94 and one second lever 93 that project from the main body portion 91 in a direction away from the rotation center axis 90. The first lever 94 and the second lever 93 are arranged at a predetermined interval in the front-rear direction when viewed from the left-right direction (the extending direction of the rotation center axis 90).

[0042] The main body portion 91 is for setting the center of gravity 9g of the inertial member 9 (see FIG. 8) at a position away from the rotation center axis 90. In the present embodiment, the center of gravity 9g of the inertial member 9 is located below the rotation center axis 90.

[0043] A pair of shaft portions 92 project from both side surfaces of the main body portion 91 along the rotation center axis 90. By inserting these shaft portions 92 into third recesses 67 formed in the side walls 62 of the frame 6, the inertial member 9 is supported by the frame 6 so as to be rotatable about the rotation center axis 90.

[0044] In the left-right direction, the second lever 93 is disposed at the center of the main body portion 91, and the two first levers 94 are disposed on both sides of the second lever 93. The first lever 94 projects from the main body portion 91 at a position behind the rotation center axis 90, and the second lever 93 projects from the main body portion 91 at a position in front of the rotation center axis 90. That is, the first lever 94 is located deeper inside the buckle body 2 than the second lever 93 in the insertion direction of the tongue plate 15. The projecting directions of the first lever 94 and the second lever 93 are substantially parallel to the line connecting the center of gravity 9g and the rotation center axis 90.

[0045] Stoppers 95 that are sharpened obliquely downward are provided at both ends of the main body portion 91. On the other hand, projecting portions 69 that can come into contact with the stoppers 95 are provided on the inner surfaces of the front portions of the respective side walls 62 of the frame 6.

[0046] Next, with reference to FIGS. 9(a) to 10(c), the operation of the buckle device 1 will be described. FIGS. 9(a) to (c) show the operation of the mechanical assembly 10 when the tongue plate 15 is engaged with the buckle device 1, and FIGS. 10(a) to (c) show the operation of the mechanical assembly 10 when the engagement of the tongue plate 15 is released. Also, hereinafter, the insertion direction of the tongue plate 15 is referred to as the A direction, and the direction opposite to the insertion direction of the tongue plate 15 is referred to as the B direction.

[0047] First, with reference to FIG. 8, the non-engaged state of the tongue plate 15 will be described. The engaging member 8 is maintained in a state of swinging upward by the biasing force of the spring 12. The locking member 5 is biased in the B direction by the spring 12, and the front end portion of the base portion 51 of the locking member 5 contacts the first restricting portion 86 of the engaging member 8. The release button 4 is biased in the B direction by the spring 11 via the ejector 7, and the front end portion of the protruding portion 44 of the release button 4 contacts the second lever 93 of the inertia member 9 located within the opening 49 of the release button 4.

[0048] Also, in the non-engaged state of the tongue plate 15, the inertia member 9 is biased by the spring 11 via the release button 4 to rotate in the direction from the first lever 94 to the second lever 93 (counterclockwise in FIG. 7), and the first lever 94 contacts the lower surface of the bridging portion 55 of the locking member 5. Thereby, the movement of the release button 4 and the rotation of the inertia member 9 are blocked, so that abnormal noise due to rattling of the release button 4 and the inertia member 9 can be prevented.

[0049] As shown in FIG. 9(a), when the tongue plate 15 is inserted into the buckle body 2, the ejector 7 moves in the A direction until it is pressed by the tongue plate 15 and contacts the leg portion 84 of the engaging member 8. Thereafter, the ejector 7 is pressed by the tongue plate 15 and moves in the A direction, so that as shown in FIG. 9(b), the engaging member 8 swings downward, and the hook portion 82 of the engaging member 8 is inserted into the engaging hole 15A provided in the tongue plate 15.

[0050] When the engaging member 8 swings downward until the first restricting portion 86 of the engaging member 8 is positioned below the first restricting portion 56 of the locking member 5, the locking member 5 moves in the B direction by the biasing force of the spring 12. During the movement of the locking member 5, the first restricting portion 56 of the locking member 5 slides on the first restricting portion 86 of the engaging member 8.

[0051] The locking member 5 moves alone in the B direction until both ends of the locking bar 13 come into contact with the front side surfaces of the grooves 47 of the release button 4 (the state shown in Fig. 9(b)). After that, as shown in Fig. 9(c), the locking member 5 moves in the B direction together with the release button 4.

[0052] Regarding the operation of the inertial member 9, until both ends of the locking bar 13 come into contact with the front side surfaces of the grooves 47 of the release button 4, when the locking member 5 moves in the B direction, as shown in Fig. 9(b), the bridging portion 55 of the locking member 5 enters between the first lever 94 and the second lever 93 of the inertial member 9 when viewed in the left - right direction (the extending direction of the rotation center axis 90). By the subsequent movement of the locking member 5 and the release button 4 in the B direction, the second lever 93 of the inertial member 9 is pressed by the front end portion of the protruding portion 44 of the release button 4, and the inertial member 9 rotates in the direction from the first lever 94 to the second lever 93 (counterclockwise in Fig. 9(c)). The rotation of the inertial member 9 stops when the stopper 95 of the inertial member 9 comes into contact with the protruding portion 69 of the frame 6, and thereby the movement of the locking member 5 and the release button 4 in the B direction also stops. This position is the locked position of the locking member 5. That is, in the locked position, the release button 4 is biased in the B direction by the spring 12 via the locking member 5. Further, when the locking member 5 moves to the locked position, the second restricting portion 57 of the locking member 5 comes into contact with the second restricting portion 85 of the engaging member 8.

[0053] After the pushing of the tongue plate 15 by the operator is released, the tongue plate 15 is biased by the spring 11 via the ejector 7 and pressed against the hook portion 82 of the engagement member 8. As a result, the engaged state of the tongue plate 15 shown in FIG. 9(c) is formed. In the engaged state of the tongue plate 15, the first lever 94 and the second lever 93 are located on the side opposite to the tongue plate 15 with respect to the rotation center axis 90.

[0054] When releasing the engagement of the tongue plate 15, as shown in FIG. 10(a), the release button 4 receives a release operation and moves in the A direction against the biasing force of the spring 12 together with the lock member 5, and the front end portion of the protruding portion 44 of the release button 4 separates from the second lever 93 of the inertial member 9. As shown in FIG. 10(b), as the release button 4 moves in the A direction of the lock member 5 to the back side of the buckle body 2, the bridging portion 55 of the lock member 5 presses the first lever 94 of the inertial member 9. As a result, the inertial member 9 rotates in the direction from the second lever 93 toward the first lever 94 (clockwise in FIG. 10(b)), and accordingly, the bridging portion 55 of the lock member 5 moves in the direction of separating from between the first lever 94 and the second lever 93 of the inertial member 9.

[0055] When the lock member 5 moves in the A direction until the first restricting portion 56 of the lock member 5 is located behind the first restricting portion 86 of the engagement member 8, as shown in FIG. 10(c), the engagement member 8 swings upward by the biasing force of the spring 12, and the engagement between the hook portion 82 of the engagement member 8 and the tongue plate 15 is released. As a result, the tongue plate 15 is pushed out by the biasing force of the spring 11 until the boss 71 of the ejector 7 contacts the protruding portion 45 of the release button 4. Also, in this state, the front end portion of the protruding portion 44 of the release button 4 and the bridging portion 55 of the lock member 5 separate from between the first lever 94 and the second lever 93 of the inertial member 9.

[0056] After the pushing of the release button 4 by the operator is released, the release button 4 moves to the position shown in FIG. 8 by the biasing force of the spring 11.

[0057] Next, with reference to FIGS. 11(a) and (b), the operations of the first lever 94 and the second lever 93 of the inertial member 9 will be described in detail. As shown in FIGS. 11(a) and (b), in the engaged state of the tongue plate 15, the rear end portion of the bridging portion 55 of the lock member 5 can contact the first lever 94, and the front end portion of the protruding portion 44 of the release button 4 can contact the second lever 93. That is, the rear end portion of the bridging portion 55 of the lock member 5 constitutes the first contact portion 31 of the operating member 3, and the front end portion of the protruding portion 44 of the release button 4 constitutes the second contact portion 32 of the operating member 3.

[0058] In the engaged state of the tongue plate 15, when viewed in the left-right direction (the extending direction of the rotation center axis 90), the first contact portion 31 and the second contact portion 32 are located between the first lever 94 and the second lever 93 in the front-rear direction. Also, as shown in FIGS. 10(a) to (c), when releasing the engagement of the tongue plate 15, the first contact portion 31 and the second contact portion 32 move in a direction away from between the first lever 94 and the second lever 93 as the inertial member 9 rotates, and in the state shown in FIG. 10(c), they are separated from between the first lever 94 and the second lever 93.

[0059] As shown in FIG. 11(a), when a first inertial force FA in the A direction acts on the operating member 3 in the engaged state of the tongue plate 15, an inertial force F1 in the A direction acts on the inertial member 9. Then, the first lever 94 applies a first pressing force Fb in the B direction to the first contact portion 31 by the inertial force F1 in the A direction. The first pressing force Fb is set to be larger than the first inertial force FA.

[0060] Here, regarding the inertial force F1 in the A direction acting on the inertial member 9, if the distance from the rotation center axis 90 to the center of gravity 9g of the inertial member 9 in the direction orthogonal to the direction of the inertial force F1 is defined as the distance L0, a torque T1 of F1×L0 is generated in the inertial member 9 around the rotation center axis 90 (counterclockwise in FIG. 11(a)). Also, at the contact point between the first contact portion 31 and the first lever 94, the direction of the force F1' acting from the first lever 94 to the first contact portion 31 due to the torque T1 is orthogonal to the surface of the first lever 94 on the side of the first contact portion 31. Then, if the distance from the contact point between the first contact portion 31 and the first lever 94 to the rotation center axis 90 in the direction parallel to the surface of the first lever 94 on the side of the first contact portion 31 is defined as the first distance L1, F1' = T1 / L1. Therefore, since the first pressing force Fb is the component of the force F1' in the direction of the first inertial force FA (A direction), if the angle formed between the acting direction of the first inertial force FA and the surface of the first lever 94 on the side of the first contact portion 31 is defined as the first angle θ1, Fb = F1'×sinθ1, that is, Fb = (T1 / L1)×sinθ1.

[0061] Also, as shown in FIG. 11(b), when a second inertial force FB in the B direction acts on the actuating member 3 in the engaged state of the tongue plate 15, an inertial force F2 in the B direction acts on the inertial member 9. And the 2 lever 93 applies a second pressing force Fa in the A direction to the second contact portion 32 due to the inertial force F2 in the B direction. The second pressing force Fa is set to be smaller than the second inertial force FB.

[0062] Here, regarding the inertial force F2 in the B direction acting on the inertial member 9, if the distance from the rotation center axis 90 to the center of gravity 9g of the inertial member 9 in a direction orthogonal to the direction of the inertial force F2 is defined as the distance L0, a torque T2 of F2×L0 is generated in the inertial member 9 around the rotation center axis 90 (clockwise in FIG. 11(b)). Also, at the contact point between the second contact portion 32 and the second lever 93, the direction of the force F2' acting from the second lever 93 to the second contact portion 32 due to the torque T2 is a direction orthogonal to the surface of the second lever 93 on the second contact portion 32 side. And if the distance from the contact point between the second contact portion 32 and the second lever 93 to the rotation center axis 90 in a direction parallel to the surface of the second lever 93 on the second contact portion 32 side is defined as the second distance L2, then F2' = T2 / L2. Therefore, since the second pressing force Fa is the component of the force F2' in the direction of the second inertial force FB (B direction), if the angle formed between the acting direction of the second inertial force FB and the surface of the second lever 93 on the second contact portion 32 side is defined as the second angle θ2, then Fa = F2'×sinθ2, that is, Fa = (T2 / L2)×sinθ2. In this embodiment, since the second angle θ2 is 90°, the second pressing force Fa is the same as the force F2'.

[0063] Here, assuming that the inertial forces in the A direction and the B direction are the same, the first inertial force FA and the second inertial force FB acting on the actuating member 3 are the same. Therefore, in order to make the first pressing force Fb larger than the first inertial force FA and the second pressing force Fa smaller than the second inertial force FB, in this embodiment, the first pressing force Fb is set to be larger than the second pressing force Fa, and the first inertial force FA and the second inertial force FB are set to be between the magnitudes of the first pressing force Fb and the second pressing force Fa.

[0064] Also, when the inertial forces in the A direction and the B direction are the same, the inertial forces F1 and F2 acting on the inertial member 9 are also the same, and as a result, the torques T1 and T2 of the inertial member are also the same. Therefore, from Fb = (T1 / L1)×sinθ1 and Fa = (T2 / L2)×sinθ2, for example, by at least one or both of making the first distance L1 smaller than the second distance L2 and making the first angle θ1 larger than the second angle θ2 within the range of 90° or less, the first pressing force Fb than The second pressing force Fa more thanIt can be set large. In this embodiment, although the first angle θ1 is smaller than the second angle θ2 due to the shape constraints, by making the first distance L1 appropriately smaller than the second distance L2, the first pressing force Fb is made larger than the second pressing force Fa. In this way, the first lever 94 and the second lever 93 can individually adjust the first distance L1 and the second distance L2, and the first angle θ1 and the second angle θ2 within the range where the first pressing force Fb is larger than the second pressing force Fa, so there is a degree of freedom in the design. It is easy to make settings considering the strength of the first lever 94 and the second lever 93 and the shape of other members.

[0065] As described above, in the buckle device 1 of this embodiment, when the first inertial force FA in the A direction acts on the operating member 3, a first pressing force Fb that is larger than the first inertial force FA and in the opposite direction to the first inertial force FA is applied from the first lever 94 of the inertial member 9 to the operating member 3. Therefore, the operation of the operating member 3 is blocked. Conversely, when the second inertial force FB in the B direction acts on the operating member 3, a second pressing force Fa in the opposite direction to the second inertial force FB is applied from the second lever 93 of the inertial member 9 to the operating member 3. However, since the second pressing force Fa is smaller than the second inertial force FB, the operating member 3 is not actuated in the A direction by the second lever 93. Therefore, regardless of the direction of the inertial force, it is possible to reliably prevent the release of the engagement of the tongue plate 15 due to the inertial force. Moreover, since the first contact portion 31 and the first lever 94 for the first inertial force FA are provided separately from the second contact portion 32 and the second lever 93 for the second inertial force FB, the degree of freedom in their design is high.

[0066] In this embodiment, in the engaged state of the tongue plate 15, the release button 4, which is the operating member 3, and the lock member 5 are biased forward (B direction) by the spring 12. Therefore, the biasing force of the spring 12 acts in the direction of reducing the first inertial force FA and increasing the second inertial force FB. Thereby, regardless of the direction of the inertial force, the effect of reliably preventing the release of the engagement of the tongue plate 15 due to the inertial force can be enhanced.

[0067] (Modification example) The present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the gist of the present invention.

[0068] For example, the actuating member 3 may be only the release button 4 as shown in FIGS. 12(a) and (b), or may be only the locking member 5 as shown in FIGS. 13(a) and (b). Thus, if the actuating member 3 is at least one of the release button 4 and the locking member 5, since the buckle device 1 usually includes the release button 4 and the locking member 5, the first contact portion 31 and the second contact portion 32 can be set without adding parts. However, as in the above embodiment, if the actuating member 3 is both the release button 4 and the locking member 5, the first contact portion 31 is provided on the locking member 5, and the second contact portion 32 is provided on the release button 4, the shapes of the release button 4 and the locking member 5 can be simplified and they can be easily manufactured, or the setting considering the strength and the shapes of other members can be facilitated.

[0069] Further, in the above embodiment, since the first lever 94 and the second lever 93 are separated in the direction of the rotation center axis 90 of the inertial member 9, the degree of freedom in setting the first lever 94, the second lever 93, the first contact portion 31, and the second contact portion 32 is increased, and even if the distance between the first lever 94 and the second lever 93 in the rotation direction of the inertial member 9 is small, there is an advantage that it is easy to ensure the strength of the actuating member 3.

[0070] Specifically, in the first modification example shown in FIGS. 12(a) and (b), instead of omitting the bridging portion 55 of the locking member 5, a bar portion 40 having a length straddling both the first levers 94 of the inertial member 9 is integrally provided on the lower surface of the projecting portion 44 of the release button 4. Then, by configuring the rear end portion of the bar portion 40 to form the first contact portion 31 of the actuating member 3 and the front end portion of the projecting portion 44 to form the second contact portion 32 of the actuating member 3, the actuating member 3 is constituted only by the release button 4. In this case, when a first inertial force FA in the A direction acts on the actuating member 3, the first pressing force Fb is not applied to the locking member 5 from the first lever 94 of the inertial member 9. However, for example, the biasing force in the forward (B direction) by the spring 12 may be made larger than the inertial force acting on the locking member 5.

[0071] Also, in the second modification example shown in FIGS. 13(a) and (b), by configuring the rear end portion of the bridging portion 55 of the locking member 5 to form the first contact portion 31 of the actuating member 3 and the front end portion of the bridging portion 55 to form the second contact portion 32 of the actuating member 3, the actuating member 3 is constituted only by the locking member 5.

[0072] In the above embodiment, although the first angle θ1 is smaller than the second angle θ2, the first pressing force Fb was set to be larger than the second pressing force Fa by appropriately making the first distance L1 smaller than the second distance L2. However, as in the second modification example shown in FIGS. 13(a) and (b), by making the first angle θ1 and the second angle θ2 the same angle (here 90°) and making the first distance L1 smaller than the second distance L2, the first pressing force Fb may be set to be larger than the second pressing force Fa.

[0073] Also, in the third modification example shown in FIGS. 14(a) and (b), similar to the second modification example, the actuating member 3 is constituted only by the locking member 5. However, in the third modification example, although the first distance L1 and the second distance L2 are the same, the first angle θ1 is made larger than the second angle θ2, and in this way, the first pressing force Fb may be set to be larger than the second pressing force Fa.

[0074] Furthermore, instead of providing surfaces having a first angle θ1 on the first lever 94 and a second angle θ2 on the second lever 93, a surface that faces the first lever 94 side and is inclined with respect to the acting direction (A direction) of the first inertial force FA may be provided on the first contact portion 31 of the actuating member 3, and the first lever 94 may be brought into contact therewith. Similarly, a surface that faces the second lever 93 side and is inclined with respect to the acting direction (B direction) of the second inertial force FB may be provided on the second contact portion 32 of the actuating member 3, and the second lever 93 may be brought into contact therewith. Even in this case, for example, by making the angle of the surface on the first contact portion 31 side larger than the angle of the surface on the second contact portion 32 side within a range of 90° or less, or by making the first distance L1 smaller than the second distance L2, the first pressing force Fb than the second pressing force Fa more than can be set larger.

[0075] In the above embodiment, the lock member 5 is configured to slide in the front-rear direction between the locked position and the unlocked position. However, the lock member 5 may be configured to rotate between the locked position and the unlocked position.

[0076] Also, contrary to the above embodiment, the center of gravity 9g of the inertial member 9 may be located above the rotation center axis 90. However, if the center of gravity 9g of the inertial member 9 is located below the rotation center axis 90 as in the above embodiment, in other words, if the first lever 94 and the second lever 93 are located on the side opposite to the tongue plate 15 with respect to the rotation center axis 90 in the engaged state of the tongue plate 15, the shapes and sizes of the first lever 94 and the second lever 93 and the first contact portion 31 and the second contact portion 32 are less likely to be restricted by the space due to the tongue plate 15.

Explanation of Reference Numerals

[0077] 1 Buckle device 15 Tongue plate 2 Buckle body 3 Actuating member 31 First contact portion 32 Second contact portion 4 Release button 5 Lock member 8 Engaging member 9 Inertial member 90 Rotation center axis 91 Main body part 93 Second lever 94 First lever

Claims

1. A buckle device into which a tongue plate provided on a vehicle seat belt is inserted and detachably engages with the inserted tongue plate, comprising: a hollow buckle body; an operating member slidably supported in the buckle body in the insertion direction of the tongue plate and operating in response to a release operation for releasing the engagement of the tongue plate; an inertial member rotatably supported in the buckle body about a rotation center axis extending in the width direction of the tongue plate, wherein the inertial member has a main body portion through which the rotation center axis passes, and a first lever and a second lever protruding from the main body portion in a direction away from the rotation center axis and arranged at a predetermined interval in the insertion direction of the tongue plate when viewed from the extending direction of the rotation center axis; the first lever is located deeper inside the buckle body in the insertion direction of the tongue plate than the second lever; the operating member is capable of contacting the first lever at a first contact portion and the second lever at a second contact portion in the engaged state of the tongue plate; the first contact portion and the second contact portion are located between the first lever and the second lever in the insertion direction of the tongue plate in the engaged state of the tongue plate, and move in a direction away from between the first lever and the second lever as the inertial member rotates when releasing the engagement of the tongue plate; the first lever applies a first pressing force in a direction opposite to the insertion direction of the tongue plate, which is greater than the first inertial force, to the first contact portion when a first inertial force in the insertion direction of the tongue plate acts on the operating member in the engaged state of the tongue plate; the second lever applies a second pressing force in the insertion direction of the tongue plate, which is smaller than the second inertial force, to the second contact portion when a second inertial force in a direction opposite to the insertion direction of the tongue plate acts on the operating member in the engaged state of the tongue plate. A buckle device characterized by the above.

2. The buckle device according to claim 1, wherein in the thickness direction of the tongue plate, a first distance from the rotation center axis of the inertial member to the contact point between the first contact portion and the first lever is smaller than a second distance from the rotation center axis of the inertial member to the contact point between the second contact portion and the second lever.

3. In the engaged state of the tongue plate, a first angle formed by the insertion direction of the tongue plate and the surface on the first contact portion side of the first lever is larger than a second angle formed by the direction opposite to the insertion direction of the tongue plate and the surface on the second contact portion side of the second lever. The buckle device according to claim 1 or 2, characterized in that.

4. A release button for receiving the release operation, An engaging member that engages with the tongue plate inserted into the buckle body, When the engaging member engages with the tongue plate, it operates in the locking direction to suppress the release of the engagement of the engaging member, and when the release button operates on the back side of the buckle body, it operates in the direction opposite to the locking direction to allow the release of the engagement of the engaging member. A locking member, The operating member is at least one of the release button or the locking member. The buckle device according to any one of claims 1 to 3, characterized in that.

5. The operating member is both the release button and the locking member. The first contact portion is provided on the locking member, and the second contact portion is provided on the release button. The buckle device according to claim 4, characterized in that.

6. The release button is biased in a direction opposite to the insertion direction of the tongue plate, In a state where the tongue plate is not inserted into the buckle body, the first lever contacts the locking member, and the second lever contacts the release button. The buckle device according to claim 5, characterized in that.

7. In the engaged state of the tongue plate, the first lever and the second lever are located on the side opposite to the tongue plate with respect to the rotation center axis. The buckle device according to any one of claims 1 to 6, characterized in that.

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