Comfort seat belt retractor

Abstract

The present invention provides a comfortable seat belt retractor. The shaft at one end of the belt reel extends into a spring box cover. An active plane scroll spring and a booster spring are arranged axially adjacent to each other at intervals within the spring box. During the middle and later stages of the seat belt withdrawal process, the active plane scroll spring and the booster spring provide elastic force to drive the seat belt in the opposite direction of movement. The present invention adds a booster spring, the direction of the elastic force provided by the booster spring is consistent with the direction of force applied by the user when manually withdrawing the seat belt, thus assisting in withdrawing the seat belt. This improves the feeling of effort experienced by the user when withdrawing the seat belt due to the elastic force provided by the active plane scroll spring alone, which increases the effort required as the length of the seat belt is extended. This improves the comfort of withdrawing the seat belt.

Description

Technical Field

[0001] The present invention relates to a vehicle safety accessory, in particular to a safety belt retracting device used by vehicle drivers and passengers. Background Art

[0002] As the name suggests, seat belts are belts that protect the lives of drivers and passengers, restraining them in the seats with appropriate force.

[0003] In addition to safety, seat belts also place new demands on the strength and comfort of the seat belts when passengers wear them.

[0004] A technical solution entitled "Seatbelt Retractor with Dual-Spring Comfort Function" (CN104968538A, hereinafter referred to as Document 1) aims to improve seatbelt comfort. In this seatbelt retractor, a spring cassette 3 is torsionally fixed to a housing 1. The spring cassette 3 also includes two parallel, parallel-acting coil springs 6 and 7, each with the same spiral direction, a coupling member 8 in the form of a coupling disc, and a switch device 33. In the solution provided by Document 1, retraction spring 6 continuously provides the seatbelt's retraction force. The retraction force provided by retraction spring 7 is selected and controlled by the switch device 33. During the retraction process, the retraction forces of retraction springs 6 and 7 are combined, providing the so-called comfort. However, a problem with Document 1 is that, during the process of pulling and holding the seatbelt, the occupant only feels the elastic force applied by retraction spring 6 to the belt, which drives it back. This elastic force gradually increases with the length of the belt extended. Therefore, Document 1 does not improve the comfort experienced by the occupant when pulling the seatbelt.

[0005] The title is "Mechanism for reducing the tension of the reel for automobile seat belts" (CN1233571A-hereinafter referred to as document 2), and the background technology part of the document 2 introduces Figure 1 The background technology scheme shown, wherein Figure 1 The scheme shown has a first and a second coil spring. Although the two coil springs are wound in opposite spirals, the two springs work in a time-sharing manner, that is, under the switching action of the clutch composed of the electromagnetic coil 56, the fabric is released by the first coil spring and the second coil spring is put into operation; in addition, in order to overcome the defects in the above-mentioned background technology, the main content of the improved technical solution provided by Document 2 is the clutch device 110 of the coil spring support 140, and the alternating working order of the first and second coil springs 130 and 150 has not changed. As recorded in its description, when the winding of the first coil spring 130 on the cylindrical platform 122 reaches the maximum limit, the clutch device 110 rotates, and this rotation forces the second coil spring 150 to wind, applying a winding force to the winding shaft 102. Summary of the Invention

[0006] The purpose of the present invention is to provide a comfortable seat belt retractor, which weakens the situation in which the pulling force gradually increases when the seat belt is pulled, stabilizes the pulling force of the seat belt and improves the comfort feeling.

[0007] To achieve the above-mentioned objectives, the present invention adopts the following technical solutions: a comfortable seat belt retractor, comprising a retractor housing, with a belt reel rotatably connected to the side walls at both ends of the retractor housing, and a spring box cover provided on the side wall at one end, characterized in that: the shaft at one end of the belt reel extends into the box cavity of the spring box cover, and an active plane volute spring and an assisting spring are axially arranged adjacent to each other on the shaft in the box cavity of the spring box cover. In the middle and rear stages of the seat belt pulling process, the active plane volute spring and the assisting spring provide elastic force to drive the seat belt to move in the opposite direction.

[0008] The active plane scroll spring in the above scheme is a basic functional spring that provides the retraction and winding of the seat belt. On this basis, the present invention adds an assist spring. The spring force provided by the assist spring drives the seat belt to move in a direction opposite to the elastic force direction of the active plane scroll spring for recovering the seat belt, that is, the elastic force direction provided by the assist spring is consistent with the force direction applied by a person manually pulling the seat belt, and thus plays a role in assisting in pulling the seat belt, thereby improving the elastic force for retracting and winding the seat belt simply provided by the active plane scroll spring, which makes the user feel more strenuous as the length of the seat belt is pulled out, thereby improving the comfort of pulling the seat belt. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0010] Figure 2 It is demolished Figure 1 Schematic diagram of the three-dimensional structure of the spring box cover;

[0011] Figure 3 yes Figure 2 A schematic diagram of the three-dimensional structure behind the hidden reel housing;

[0012] Figure 4 yes Figure 3 Schematic diagram of the three-dimensional structure after the active plane scroll spring is hidden;

[0013] Figure 5 yes Figure 4 Schematic diagram of the three-dimensional structure behind the hidden circular partition;

[0014] Figure 6 It is a schematic diagram of the three-dimensional structure of the inner end surface of the spring box cover;

[0015] Figure 7 yes Figure 6 A schematic diagram of the three-dimensional structure after the active planar scroll spring is arranged;

[0016] Figure 8 yes Figure 7 Schematic diagram of the three-dimensional structure after adding a circular partition;

[0017] Figure 9 yes Figure 8 Schematic diagram of the three-dimensional structure after the auxiliary flat scroll spring is added;

[0018] Figure 10 It is a three-dimensional diagram of the active and power-assisted flat scroll spring and the circular partition in the separated state. DETAILED DESCRIPTION

[0019] The axial and circumferential positions and directions involved in the following description are consistent with the axial and circumferential directions of the seat belt reel 20 .

[0020] Combine Figure 1 A comfortable seat belt retractor includes a retractor housing 10, and a belt drum 20 is rotatably connected to the side walls 11 at both ends of the retractor housing 10. A spring box cover 30 is provided on one end side wall 11, and a cylinder shaft 21 at one end of the belt drum 20 extends into the box cavity of the spring box cover 30. The axial end of the cylinder shaft 21 located in the box cavity of the spring box cover 30 is axially adjacent to and spaced apart from an active plane scroll spring 40 and an assist spring. In the middle and rear stages of the seat belt pulling process, the active plane scroll spring 40 and the assist spring provide elastic force to drive the seat belt to move in the opposite direction.

[0021] As for the active plane volute spring 40 that always provides the seat belt for winding and retraction (not shown in the figure), when the seat belt is wound to a fully retracted state, the active plane volute spring 40 is pre-tightened to a smaller torque acting on the seat belt to keep the seat belt always in a fully retracted state. As the seat belt is continuously pulled out, the winding and retraction torque of the active plane volute spring 40 acting on the seat belt gradually increases. The seat belt user also needs to gradually increase the force of pulling the seat belt before pulling the seat belt to the seat belt buckle seat next to the seat cushion. The assist spring provided by the present invention provides external assistance during the seat belt pulling process to offset the increasing trend of the active plane volute spring 40 with the increase of the length of the seat belt pulled out. The user can pull the seat belt into place by maintaining a basically stable pulling force, which improves the stability of the seat belt pulling force. The resistance spring provided by the present invention should at least start to intervene in the middle of the total length of the seat belt pulled out, because in the front pulling process, the pulling force required to overcome the active plane volute spring 40 is relatively small.

[0022] Combine Figure 2 、 3, 5, 7, 9, and 10, the booster spring is a booster plane vortex spring (50), the active plane vortex spring (40) and the booster plane vortex spring (50) have opposite winding directions, the outer winding ends (41, 51) of the active plane vortex spring (40) and the booster plane vortex spring (50) are relatively fixed to the reel housing (10), and the inner winding ends (42, 52) of the active plane vortex spring (40) and the booster plane vortex spring (50) are connected to the cylindrical shaft (21) located in the box cavity of the spring box cover (30);

[0023] At the initial position of the fully retracted state of the safety belt, the direction in which the assisting plane scroll spring (50) is pre-tightened to provide elastic force therefor is consistent with the direction of the pre-tightening force of the active plane scroll spring (40).

[0024] Since the axial space occupied by the flat scroll spring is very small, both the active flat scroll spring 40 and the assisting flat scroll spring 50 are selected as flat scroll springs. This can save axial space and can be processed using the same spring strip material. The only difference is that the number of winding turns is determined according to the specific design parameters, and the bending direction of the inner and outer turn ends is adapted to the specific structure of the spring seat. Detailed instructions are provided below.

[0025] Preferably, the outer turn ends 41 and 51 of the active planar spiral spring 40 and the assisting planar spiral spring 50 are connected to the spring box cover 30 .

[0026] More preferably, a protrusion 31 is provided in the box cavity of the spring box cover 30 , and the outer turn ends 41 , 51 of the dynamic plane spiral spring 40 and the assisting plane spiral spring 50 are connected to the protrusion 31 .

[0027] Combine Figure 6 The protrusion 31 is in the shape of an arc strip, and one side of the curved edge is connected to the circular box top 32 of the spring box cover 30. The center of curvature of the arc of the protrusion 31 is concentric with the center of curvature of the circular tubular box wall 33 of the circular tubular spring box cover 30, and the two ends of the arc length of the protrusion 31 are spaced apart from the box wall 33. In a specific implementation, the entire arc length of the protrusion 31 is spaced apart from the box wall 33. By making the protrusion 31 in the shape of an arc strip, only one fixing member, namely the protrusion 31, is required to fix the outer turn ends 41 and 51 of the active planar scroll spring 40 and the auxiliary planar scroll spring 50. Due to the arc-shaped strip shape of the protrusion 31, its two ends have sufficient span in the circumferential direction, which effectively avoids the interference between the two outer turn ends 41 and 51, and improves the stability of the position of the two outer turn ends 41 and 51. At the same time, the forces acting on the protrusion 31 by the two springs offset each other, eliminating the possibility of stress bending and cracking between the protrusion 31 and the box top 32. It should be noted here that the arc length of the protrusion 31 does not need to be too large, so as to facilitate the installation of the two outer turn ends 41 and 51 without interfering with each other.

[0028] Combine Figure 2 、 3 As shown in Figures 4, 5, 7, 8, 9, and 10, a circular partition 60 is provided in the spring box cover 30. The active planar scroll spring 40 and the assisting planar scroll spring 50 are placed on both sides of the circular partition 60. A through hole 62 in the middle of the circular partition 60 allows the axial end of the cylindrical shaft 21 to pass through. The circular partition 60 can separate the active planar scroll spring 40 and the assisting planar scroll spring 50, preventing the spring bodies of the two from interfering with each other and ensuring that the active planar scroll spring 40 and the assisting planar scroll spring 50 can be retracted freely.

[0029] The protrusion 31 passes through the through hole 61 provided on the circular partition 60 and is suspended. The edge of the circular partition 60 is clamped on the notch-shaped clamping groove 331 on the inner wall of the box wall 33 with the opening pointing to the shaft core.

[0030] When setting up a circular partition 60, it is still necessary to use an arc-shaped plate-shaped protrusion 31 to fix the outer turn ends 41 and 51 of the two springs. It is necessary to give the protrusion 31 an appropriate suspension size in the axial direction to ensure that the protrusion 31 can be placed on both sides of the circular partition 60. The above scheme is to open a through hole 61 on the circular partition 60, and a part of the protrusion 31 is located in the axial range surrounded by the circular partition 60 and the box top 32. The protrusion 31 within the range is used to fix the outer turn end 41 of the active plane spiral spring 40 within the range; the arc-shaped plate of the protrusion 31 passing through the through hole 61 protrudes to the other plate side of the circular partition 60 away from the box top 32, and the protrusion 31 on this side is used to fix the outer turn end 51 of the assist plane spiral spring 50.

[0031] like Figures 6 to 9 As shown, axially arranged ribs 332 are arranged on either side of the slot 331, and a groove 311 is provided in the middle of the curved plate surface of the protrusion 31 to constrain the edge of the through hole 61 of the circular partition 60. The slot 331 is used to constrain the edge of the circular partition 60, the groove 311 is used to constrain the opening of the through hole 61, and the area between the ribs 332 clamps the two side plates at the edge of the circular partition 60. This effectively defines the axial position of the circular partition 60, and the ribs 332 contact the outermost turns of the active planar scroll spring 40 and the assisting planar scroll spring 50, thus preventing severe friction and noise caused by direct contact between the strip spring body and the box wall 33.

[0032] Combine Figure 10The U-shaped hook-shaped outer turn end 41 of the active plane scroll spring 40 is buckled on the A end in the arc length direction of the protrusion 31, and the U-shaped hook-shaped inner turn end 42 of the active plane scroll spring 40 is buckled on the active spring fixed tooth arm 211 on the cylindrical shaft 21. The U-shaped hook-shaped outer turn end 51 of the assisting plane scroll spring 50 is buckled on the B end in the arc length direction of the protrusion 31, and the U-shaped hook-shaped inner turn end 52 of the assisting plane scroll spring 50 is buckled on the assisting spring fixed tooth arm 212 on the cylindrical shaft 21. The active spring fixed tooth arm 211 and the assisting spring fixed tooth arm 212 are in reverse ratchet tooth shapes. The active spring fixing tooth arm 211 is connected to the end of the cylindrical shaft 21, which passes through the central through hole 62 of the circular partition 60. In this way, the active spring fixing tooth arm 211 and the auxiliary spring fixing tooth arm 212, which are located on both sides of the circular partition 60, can still achieve constrained fixation with the inner turn end 42 of the active planar scroll spring 40 and the inner turn end 52 of the auxiliary planar scroll spring 50. In addition, the active spring fixing tooth arm 211 and the auxiliary spring fixing tooth arm 212 have holes in their middle portions that are sleeved onto the axial end section of the cylindrical shaft 21 and are secured and locked by axially arranged bolts 213.

[0033] In the initial position of the fully retracted state of the seat belt, the direction in which the assisting planar volute spring 50 is pre-tightened and provides elastic force thereto is consistent with the direction of the pre-tightening force of the active planar volute spring 40 .

[0034] In the initial position of the fully retracted state of the seat belt, the direction in which the assisting plane volute spring 50 is pre-tightened to provide it with elastic force is in the same direction as the pre-tightening force of the active plane volute spring 40. The superposition of the elastic forces of the two is greater than the winding and retraction force provided by the active plane volute spring 40. This ensures that the seat belt still maintains a suitable winding torque when it is in the latter part of the winding and retraction process, until the seat belt is fully recovered and stably maintained in the fully retracted state. At the beginning of the seat belt pulling, although the assisting plane volute spring 50 does not provide pulling assistance but provides some resistance, the resistance is very small and quickly disappears to zero, and then quickly changes direction to provide pulling assistance.

Claims

1. A comfort safety belt retractor, comprising a retractor housing (10), a belt reel (20) rotatably connected to the side walls (11) at both ends of the retractor housing (10), and a spring box cover (30) provided on one end of the side wall (11), characterized in that: One end of the drum shaft (21) of the belt reel (20) extends into the box cavity of the spring box cover (30), and the active plane volute spring (40) and the assist spring are arranged axially adjacent to the axial end of the drum shaft (21) in the box cavity of the spring box cover (30). In the middle and rear stages of the process of pulling the seat belt, the active plane volute spring (40) and the assist spring provide elastic force to drive the seat belt to move in the opposite direction. The booster spring is a booster plane vortex spring (50), the active plane vortex spring (40) and the booster plane vortex spring (50) have opposite winding directions, the outer turn ends (41, 51) of the active plane vortex spring (40) and the booster plane vortex spring (50) are relatively fixed to the retractor housing (10), the inner turn ends (42, 52) of the active plane vortex spring (40) and the booster plane vortex spring (50) are connected to the cylindrical shaft (21) located in the box cavity of the spring box cover (30), and in the initial position of the safety belt fully retracted, the direction of the elastic force provided by the pre-tightening of the booster plane vortex spring (50) is consistent with the pre-tightening direction of the active plane vortex spring (40); A circular partition (60) is provided in the spring box cover (30), and the active plane scroll spring (40) and the assist plane scroll spring (50) are respectively placed on both sides of the circular partition (60). A through hole (62) in the middle of the circular partition (60) is provided for the shaft end of the cylindrical shaft (21) to pass through; The protrusion (31) passes through the through hole (61) provided on the circular partition (60) and is suspended. The edge of the circular partition (60) is clamped on the notch-shaped clamping groove (331) on the inner wall of the box wall (33) with the opening pointing to the shaft core. The middle through hole (62) of the circular partition (60) is for the shaft end of the cylindrical shaft (21) to pass through. The outer turn end (41) of the active plane volute spring (40) is buckled on the A end of the protrusion (31) in the arc length direction, and the inner turn end (42) of the active plane volute spring (40) is buckled on the active spring fixed tooth arm (211) on the cylindrical shaft (21). The outer turn end (51) of the power-assisting plane volute spring (50) is buckled on the B end of the protrusion (31) in the arc length direction, and the inner turn end (52) of the power-assisting plane volute spring (50) is buckled on the power-assisting spring fixed tooth arm (212) on the cylindrical shaft (21). The active spring fixed tooth arm (211) and the power-assisting spring fixed tooth arm (212) are in the shape of reverse ratchet teeth.

2. The comfort seat belt retractor according to claim 1, characterized in that: The outer turn ends (41, 51) of the active plane volute spring (40) and the boosting plane volute spring (50) are connected to the spring box cover (30).

3. The comfort seat belt retractor according to claim 2, characterized in that: A protrusion (31) is provided in the box cavity of the spring box cover (30), and the outer winding ends (41, 51) of the active plane spiral spring (40) and the auxiliary plane spiral spring (50) are connected to the protrusion (31).

4. The comfort seat belt retractor according to claim 3, characterized in that: The protrusion (31) is in the shape of an arc strip and one side of the protrusion (31) is connected to the circular box top (32) of the spring box cover (30). The arc curvature center of the protrusion (31) is concentric with the curvature center of the circular tubular box wall (33) of the circular tubular spring box cover (30). The two ends of the protrusion (31) in the arc length direction are spaced apart from the box wall (33).

5. The comfort seat belt retractor according to claim 1, characterized in that: There are axially arranged ribs (332) on both sides of the slot (331).

6. The comfort seat belt retractor according to claim 1, characterized in that: A groove (311) is provided in the middle of the arc-shaped plate surface of the protrusion (31) for constraining the edge of the through hole (61) of the circular partition (60).

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