KR102567086B1 - Digressive load limiter - Google Patents

Abstract

In the progressive load limiter according to the present invention, when an impact is generated from the outside, the pretensioner operates to fix the pilot wheel connected to one end of the spool on which the webbing is wound. As a load limiter that controls whether the load acting on the webbing exceeds a predetermined load, it is installed in the hollow part formed in the center of the spool, and when the load acting on the webbing reaches the first load, the load acting on the webbing is twisted. and an initial load increasing unit that increases the first load by suppressing relative rotation of the spool and the pilot wheel until the load acting on the webbing becomes a second load lower than the first load.

Description

Degressive load limiter {DIGRESSIVE LOAD LIMITER}

The present invention relates to a progressive load limiter, and more particularly, to a retractor capable of preventing an overshoot phenomenon by separating a pretensioner operation and a load limiter operation, thereby increasing the initial operating load at which the load limiter operates. It relates to a progressive load limiter provided with an initial load increasing unit.

When a person rides in a vehicle or device, a seat belt, which is one of several safety devices, is used to prevent the person on board from escaping from the vehicle or device due to collision between vehicles or other objects. Thus, it is possible to stably fix the lower abdomen and chest of a person riding in a vehicle or appliance to the seat.

However, the degree of collision between vehicles or other objects increases beyond a standard, and seat belts do not function properly.

Therefore, various technologies are being developed to enable seat belts to function properly even when the degree of collision between vehicles or with other objects is high, and among them, a retractor is currently in the spotlight.

Specifically, the retractor includes a pre-tensioner that enhances the function and effect of the seat belt by retracting the webbing of the seat belt in the event of a collision between vehicles or other objects, and the webbing after the pre-tensioner operates. An ELR operation unit (Emergency Locking Retractor Operating Part) locking one side of the spool to prevent it from being drawn out may be provided.

The operation of the pretensioner and the ELR operation unit operates the piston located in the cylinder using the energy generated when the gas explodes, and as the piston operates, the structure associated with the piston operates to reverse the spool, thereby increasing the safety of the occupant. It can work in a way that limits forward movement.

However, due to the gas remaining in the cylinder after the gas explodes in the pretensioner, overshoot, a phenomenon in which the load acting on the occupant increases rapidly due to the gas remaining in the cylinder after the gas explodes in the pretensioner phenomena may occur.

For example, as shown in FIG. 1, the conventional retractor has a structure in which a rack having gear teeth among the configuration of the pretensioner is engaged with the pinion A1 by the explosive force generated in the gas generator, so the above-described overshoot phenomenon There is a problem that the initial operating load of the load limiter (hereinafter referred to as DLL) including the torsion bar A2 and the rod form A3 may be distributed from a predetermined load.

Recently, in order to separate the operation of the pretensioner and the operation of the load limiter to prevent an overshoot phenomenon, a study has been conducted in which the above-mentioned DLL is grafted onto a retractor prepared by fixing a pilot wheel connected to one end of the spool (Sealed PT System). is actively underway.

However, in order to implement the DLL described above in the retractor of the Sealed PT System method, an increase in overall size and weight is inevitable. There is a problem that a member that increases the operating load cannot be disposed.

The present invention is to solve the above problems, provided in a retractor capable of preventing the overshoot phenomenon by separating the pretensioner operation and the load limiter operation, An initial load that can increase the initial operating load at which the load limiter operates It is a challenge to provide a progressive load limiter with an increasing portion.

The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the description below.

In order to solve the above problems, the progressive load limiter according to one embodiment of the present invention is a retractor for fixing a pilot wheel connected to one end of a spool on which a webbing is wound by operating a pretensioner when an impact is generated from the outside As a progressive load limiter for controlling the load acting on the webbing to exceed a predetermined load, it is mounted in the hollow formed in the central part of the spool, and when the load acting on the webbing reaches a first load, it is twisted and a torsion bar limiting the load acting on the webbing; and an initial load increasing unit configured to increase the first load by suppressing relative rotation of the spool and the pilot wheel until the load acting on the webbing becomes a second load lower than the first load.

The initial load increasing unit may include a connection unit having one end fixed to the pilot wheel and surrounding the torsion bar in a hollow portion formed in a central portion of the spool; And one side is fixed to the spool and the other side is connected to the connection unit, and when the load acting on the webbing reaches the first load, it is deformed along with the torsion bar and when it reaches the second load, it is connected to the connection unit. It may include a wire unit that is released.

In addition, the connection unit is provided as a hollow tube having one end fixed to the pilot wheel, and the wire unit may be connected to a connection area formed on an outer circumferential surface.

In addition, the connection area may be formed long in one direction from the other end of the connection unit so that the wire unit can be drawn in or removed from the other end of the connection unit.

At this time, the connection area may be spaced apart from each other at predetermined intervals along the outer circumferential surface of the connection unit.

Specifically, the wire unit may include a fixing member fixed to the spool; and a rod form member connected to the fixing member, introduced into the connection area, and separated from the connection unit under the second load.

In addition, the rod form member may move to the other side of the connection unit along the connection area under the first load, and then depart from the connection area under the second load.

In addition, the rod form member may be formed long in the longitudinal direction of the connection area and provided in a symmetrical shape with respect to the fixing member.

In addition, the fixing member has a length in a direction perpendicular to the longitudinal direction of the rod form member and is inserted into the spool, and both ends of the rod form member may be connected.

Meanwhile, the wire unit may further include a guide member for preventing the fixing member from being separated from the spool by the rod form member being separated.

According to the progressive load limiter of the present invention, the following effects are obtained.

First, when an external shock occurs, the pretensioner operates to fix the pilot wheel connected to one end of the spool on which the webbing is wound (even in a retractor of a sealed PT system, it is possible to increase the initial operating load of the load limiter. There are advantages.

Second, there is an advantage of minimizing the effect of the gas residual pressure of the gas generator.

Third, there is an advantage in minimizing bodily injury to the driver.

Fourth, the structure is simple, the operation reliability is high, and the manufacturing is easy.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

The above summary, as well as the detailed description of the preferred embodiments of the present application set forth below, will be better understood when read in conjunction with the accompanying drawings. Preferred embodiments are shown in the drawings for the purpose of illustrating the present invention. However, it should be understood that this application is not limited to the precise arrangements and instrumentalities shown.
1 is a view showing the appearance of a progressive load limiter according to the prior art;
Figure 2 is a view showing a retractor equipped with a progressive load limiter according to an embodiment of the present invention;
3 is an exploded perspective view for explaining a progressive load limiter according to an embodiment of the present invention;
4 is a view showing a connection unit of a progressive load limiter according to an embodiment of the present invention;
5 is a view showing a wire unit of a progressive load limiter according to an embodiment of the present invention;
6 is a diagram for explaining an operating state of a progressive load limiter according to an embodiment of the present invention;
FIG. 7 is a diagram showing a load graph of a progressive load limiter for explaining the operation of FIG. 6 .

Hereinafter, a preferred embodiment of the present invention in which the object of the present invention can be realized in detail will be described with reference to the accompanying drawings. In describing the present embodiment, the same name and the same reference numeral are used for the same configuration, and additional description thereof will be omitted.

1 is a view showing the appearance of a progressive load limiter according to the prior art, Figure 2 is a view showing a retractor equipped with a progressive load limiter according to an embodiment of the present invention, Figure 3 is one of the present invention It is an exploded perspective view for explaining a progressive load limiter according to an embodiment, Figure 4 is a view showing a connection unit of a progressive load limiter according to an embodiment of the present invention, Figure 5 is a view according to an embodiment of the present invention It is a diagram showing a wire unit of a progressive load limiter, FIG. 6 is a diagram for explaining the operating state of the progressive load limiter according to an embodiment of the present invention, and FIG. 7 is a degressive load limiter for explaining the operation of FIG. This is a diagram showing the load graph of the load limiter.

As shown in FIGS. 2 and 3 , the progressive load limiter 10 according to an embodiment of the present invention may largely include a torsion bar 100 and an initial load increasing unit 200 .

First, in the progressive load limiter 10 according to an embodiment of the present invention, as shown in FIG. 2, in order to eliminate the above-mentioned overshoot phenomenon, when an external shock is generated, the pretensioner operates to the spool around which the webbing is wound. The pilot wheel (P) connected to one end of (S) is disposed in the retractor (1), that is, the retractor (1) of the Sealed PT System type, and the load acting on the webbing exceeds the preset load, so the occupant injury can be prevented.

First, the torsion bar 100 is disposed in a hollow part formed in the center of the spool (S), so that one side may be mounted on the spool (S) and the other side may be connected to the pilot wheel (P).

At this time, a spool bearing (SB) is provided between the spool (S) and the pilot wheel (P) to reduce the frictional force for relative rotation.

Specifically, the torsion bar 100 may have a rotational axis and coaxiality of the spool (S) in the hollow formed in the center of the spool (S), and when the load acting on the webbing due to external impact reaches the first load, it is twisted. By rotating the spool (S) while holding it, it is possible to limit the load acting on the webbing so that it does not exceed the first load.

For example, after the pretensioner operates due to external impact, the pilot wheel is fixed, and the spool (S) connected by the torsion bar 100 is also fixed. After that, as time elapses, the occupant's body leans forward due to inertia, and the load acting on the webbing gradually rises to reach the first load.

As described above, when the load acting on the webbing reaches the first load, the torsion bar 100 is twisted and rotates the spool (S) so that the load acting on the webbing does not exceed the first load and is maintained for a predetermined time. It is possible to prevent a situation in which an occupant is injured due to the webbing.

In other words, the first load may be an initial operating load at which the progressive load limiter 10 operates.

Here, the above-described torsion bar 100 may be twisted twice before the collision force due to external impact disappears, and may be twisted 5 to 6 times until just before being broken.

In addition, the torsion bar 100 may be provided with a steel material to increase the initial operating load in some cases, and at this time, the torsion bar 100 may be twisted up to 7 to 8 times until just before breakage.

In addition, the torsion bar 100 has a length along the rotational axis of the above-described spool (S), and annular connecting pieces protruding outward from the center may be provided on outer circumferential surfaces of one side and the other side, respectively.

In addition, grooves formed in the direction of the central axis of the connection piece are arranged at predetermined intervals along the outer circumferential surface, and may be engaged and fixed to the spool (S) and the pilot wheel (P), respectively.

At this time, in the retractor 1 of the above structure, in order to have a higher level of initial operating load than the torsion bar 100 alone, the progressive load limiter 10 of the present invention includes an initial load increasing unit 200 can do.

Specifically, the initial load increasing unit 200 suppresses the relative rotation of the spool (S) and the pilot wheel (P) until the load acting on the webbing becomes a second load lower than the above-described first load over time. By doing so, the first load can be increased.

That is, the initial load increasing unit 200 connects the spool S and the pilot wheel P together with the above-described torsion bar 100 in the retractor 1 having the above structure to suppress relative rotation of each other, It is possible to increase the initial operating load at which the progressive load limiter 10 of the present invention operates, and therefore, even when the weight of the occupant is high, it is possible to prevent injury to the occupant, particularly chest injury.

Here, when there is only the torsion bar 100, the pilot wheel P is fixed by the pretensioner and the load limiter operates at a load A lower than the first load.

However, in the progressive load limiter 10 according to an embodiment of the present invention, after the pilot wheel P is fixed by the pretensioner, the torsion bar 100 and the initial load increasing unit 200 in the first step S1 By suppressing the relative rotation of the spool (S) and the pilot wheel (P) together, the initial operation is raised to a first load higher than the above-described load A, and after a predetermined time has elapsed, the initial load increasing unit 200 The relative rotation of the gas spool (S) and the pilot wheel (P) is not suppressed.

In other words, since the combination of the torsion bar 100 and the initial load increasing unit 200 provides an additional load limiting effect in the first step, and the load limiting effect is provided only by the torsion bar 100 in the second step, the present invention The progressive load limiter 10 may perform the same gradual load limit as a progressive load limiter (PLL).

The aforementioned initial load increasing unit 200 may specifically include a connection unit 220 and a wire unit 240 .

First, one end of the connection unit 220 may be fixed to the pilot wheel P, and is disposed in a hollow portion formed in the central portion of the spool S to surround the above-described torsion bar 100 to form a wire unit 240 and It is connected so that rotation of the spool (S) relative to the pilot wheel (P) can be suppressed.

One side of the wire unit 240 is fixed to the spool (S) and the other side is connected to the connection unit 220. Specifically, torsion occurs in the first step (S1) when the load acting on the webbing reaches the first load described above. When the bar 100 is deformed and reaches the second load, the connection with the connection unit 220 is released, so that only the torsion bar 100 can be twisted in the above-described second step S1.

Here, the wire unit 240 is connected to the connection unit 220 until it reaches the second load from the first load, and is deformed by the rotation of the spool S relative to the pilot wheel P and then reaches the second load. When this happens, the connection with the connection unit 220 can be completely released.

Here, specific details regarding the deformation of the wire unit 240 will be described later.

That is, in the first step (S1), as the connection unit 220 and the wire unit 240 are connected to each other, the pilot wheel P and the spool S are suppressed together with the torsion bar 100, and thus the initial operating load By raising the threshold value, it is possible to provide a higher complex level of load limit than when the torsion bar 100 alone is used.

Also, in the second step (S1), only the torsion bar 100 is twisted to provide a lower load limit than in the first step (S1).

As shown in FIG. 4, the connection unit 220 is provided as a hollow tube having one end fixed to the pilot wheel P, and the wire unit 240 described above can be connected to the connection area 222 formed on the outer circumferential surface. there is.

For example, the connection unit 220 may be provided with a hollow tube so that a space in which the torsion bar 100 is disposed is secured, and at this time, it has the same axis as the central axis of the spool (S), and also the torsion bar ( 100) may have the same axis as the central axis.

In other words, the connection unit 220 may be disposed inside the spool S so that the torsion bar 100 may be disposed therein.

That is, the connection unit 220 may be formed of a hollow tube having a smaller size than the spool S formed of the hollow tube and placed in the spool S.

In addition, one end of the connection unit 220 has a predetermined thickness in the longitudinal direction, and is provided so as to increase in diameter from the center to the outer circumferential direction, and a step may be formed.

Due to the step as described above, the step may be in contact with one side of the spool (S) to fix the position in the spool (S).

In addition, gear teeth protruding toward the center may be formed from an inner circumferential surface of one side of the connection unit 220 .

Here, the gear teeth may protrude from the inner circumferential surface in a tapered shape that becomes narrower toward the center.

In other words, based on the virtual reference plane perpendicular to the central axis of the gear connection unit 220, the cross section may be provided in a trapezoidal shape with the upper end narrower than the lower end.

At this time, a plurality of the above-described gear teeth may be arranged at a predetermined interval along the inner circumferential surface of one side of the connection unit 220, and due to these gear teeth, the connection unit 220 may be fixed to the other side of the pilot wheel P without rotation. there will be

The connection area 222 formed on the outer circumferential surface of the connection unit 220 to which the above-described wire unit 240 is connected is where the wire unit 240 is drawn in from the other end of the connection unit 220 or where the wire unit 240 is connected. It can be formed long in one direction from the other end of the connection unit 220 so that it can be deformed from the first step (S1) and completely separated through the other end of the connection unit 220 in the second step (S1).

That is, the connection area 222 may be a groove having a length in the direction of the central axis of the connection unit 220 and a depth in the direction of the central axis from the outer circumferential surface.

In other words, the connection area 222 provided in the form of a groove formed elongated in the longitudinal direction can serve as a guide for the wire unit 240 to be separated in the longitudinal direction while the wire unit 240 contacts and slides on the inner circumferential surface. .

In summary, when the spool (S) rotates in the above-described first step (S1), the wire unit 240 is connected in the longitudinal direction of the connection area 222 by the connection area 222 formed on the fixed pilot wheel P. It starts to deform while sliding, and can be completely released to the other side of the connection unit 220 in the second step (S1).

At this time, the other end of the connection area 222 from which the wire unit 240 is detached or retracted may be provided with a wider end in order to minimize interference with the moving wire unit 240 .

In addition, at least one end of the other end and one end of the above-described connection area 222 may be provided to be rounded to minimize interference with the moving wire unit 240 .

In addition, the connection area 222 may be spaced apart from each other along the outer circumferential surface of the connection unit 220 at predetermined intervals, and the wire unit 240 may be drawn in or removed from the connection area 222 .

Next, the wire unit 240 drawn in or out of the connection area 222 as described above may include a fixing member 242 and a rod form member 244 as shown in FIG. 5 .

Specifically, the fixing member 242 fixed to the spool S may have a length in a direction perpendicular to the longitudinal direction of the rod form member 244 and may be provided in a form inserted into and fixed to the spool S. If the same function is performed, the structure, shape, and material may vary, and the scope of rights is not limited due to this, of course.

However, if the bar shown in the drawings is described as an example for more detailed description, the fixing member 242 may be provided in a semicircular shape, where the central axis of the above-described semicircular fixing member 242 is the center of the spool (S). It may be positioned and fixed at the other end of the spool (S) to contact the shaft.

Also, the fixing member 242 may be changed into a shape different from that shown in the drawing.

For example, the vicinity of the inflection point of the fixing member 242 provided in a semicircular shape is bent toward one side of the spool (S) and provided to be caught on the other side of the spool (S) to strengthen the fixing force, and on the other side of the spool (S) A fixing piece may be formed on the opposite fixing member 242 and a coupling groove into which the fixing piece is force-fitted may be formed on the other side of the spool (S) facing the fixing piece.

In addition, the vicinity of the inflection point of the fixing member 242 provided in a semicircular shape is bent toward the other side of the spool (S), and the fixing member 242 is bent on the other side of the spool (S) due to the external pressure generated by the deformation in the first step (S1). You can also prevent it from escaping.

Next, the rod form member 244 is connected to the fixing member 242 and introduced into the connection area 222, and is provided so that it can be completely separated from the connection unit 220 at the second load, so that the spool (S) and the pilot Relative rotation of the wheel P can be suppressed.

Here, when the fixing member 242 is provided in a semicircular shape as described above, the rod form member 244 may be connected to both ends thereof.

In addition, the rod form member 244 may be provided in a symmetrical shape with respect to the fixing member 242 and may be formed long along the longitudinal direction of the connection area 222 .

For example, the rod form member 244 is bent from both ends of the fixing member 242 toward the connection unit 220, that is, toward the connection area 222 formed on the outer circumferential surface of the connection unit 220, and the torsion bar 100 It may have the same longitudinal direction as

That is, as described above, the rod form member 244 may be inserted into the connection area 222 or provided in a long bar shape so that it can be separated from the connection area 222.

The road form member 244 may move to the other side of the connection unit 220 along the connection area 222 under the first load and then be separated from the connection area 222 under the second load. (244) can be deformed between the fixing members (242).

That is, interference with the torsion bar 100, the spool (S), the pilot wheel (P), etc. in the second step (S1) in which the function of suppressing the relative rotation of the pilot wheel (P) and the spool (S) is no longer required. It can be modified so that it does not.

In other words, in the second step (S1), the rod form member 244 can be deformed to minimize the space it occupies.

For example, the wire unit 240 having the configuration described above may further include a guide member 246 .

The guide member 246 not only prevents the fixing member 242 from being separated from the spool S by the detached rod form member 244, but also deforms the detached rod form member 244 as described above. The space occupied by the wire unit 240 can be minimized.

At this time, the guide member 246 is provided in a circular ring shape, and the other side is formed with a larger diameter than one side, so that a step difference can be formed between one side and the other side, and the other side of the connection unit 220 is on the stepped surface due to the step difference. The rod form member 244 coming into contact with it can be deformed.

Specifically, as shown in FIG. 6 , the rod form member 244 may be pulled to the other side of the connection area 222 of the connection unit 220 when the first step (S1) starts.

Accordingly, the detached part of the road form member 244 comes into contact with the step of the above-described guide member 246, and thus the road form member 244 is deformed and wound around the front circumference of the step face in the guide member 246 , it is possible to minimize the space occupied by the road form member 244.

Therefore, as shown in FIG. 7, when the load acting on the webbing after the pretensioner operates, that is, when the torsion bar 100 and the initial load increasing unit 200 are organically connected to become the first load, in one embodiment of the present invention Both the torsion bar 100 and the initial load increasing unit 200 of the progressive load limiter 10 operate according to the method, and the load acting on the webbing during the first step S1 can be limited so that it does not exceed the first load. there is.

In addition, in the second step (S1) in which the load acting on the webbing becomes the second load, since the rod form member 244 is separated from the connection area 222, only the torsion bar 100 operates to act on the webbing. The load is limited so that it does not exceed the second load.

Therefore, its structure is simple, operation reliability is high, and manufacturing is easy. In the progressive load limiter of the present invention, when an external impact occurs, the pretensioner operates to fix the pilot wheel connected to one end of the spool on which the webbing is wound. Since the retractor of the sealed PT system is used, it has the advantage of minimizing the effect of the residual gas pressure of the gas generator. It can be raised, and accordingly, there is an advantage of minimizing bodily injury to the driver.

As described above, the preferred embodiments according to the present invention have been reviewed, and the fact that the present invention can be embodied in other specific forms without departing from the spirit or scope in addition to the above-described embodiments is a matter of ordinary knowledge in the art. It is self-evident to them. Therefore, the embodiments described above are to be regarded as illustrative rather than restrictive, and thus the present invention is not limited to the above description, but may vary within the scope of the appended claims and their equivalents.

1: retractor
10: Degressive load limiter
S: spool
SB: spool bearing
P: pilot wheel
100: torsion bar
200: initial load increasing unit
220: connection unit
240: wire unit
242: fixing member
244: road form member
246: guide member
S1: first step
S2: Second step

Claims (10)

When an external impact occurs, the pretensioner operates to secure the pilot wheel connected to one end of the spool on which the webbing is wound. As a progressive load limiter that controls that the load acting on the webbing exceeds a predetermined load,
a torsion bar installed in the hollow part formed in the central part of the spool and twisting when the load acting on the webbing reaches a first load and limiting the load acting on the webbing; and an initial load increasing unit configured to increase the first load by suppressing relative rotation of the spool and the pilot wheel until the load acting on the webbing becomes a second load lower than the first load,
The initial load increasing unit,
A connection unit having one end fixed to the pilot wheel and one end fixed to the pilot wheel in a hollow part formed in the central part of the spool and connected to the connection unit, the load acting on the webbing is It is characterized in that it includes a wire unit that is deformed together with the torsion bar when a load is reached and disconnected from the connection unit when the second load is reached.
The connection unit is
One end is provided as a hollow tube fixed to the pilot wheel, and the wire unit is connected to a connection area formed on an outer circumferential surface, and is connected to a fixing member fixed to the spool and to the fixing member to enter the connection area. And characterized in that it comprises a rod form member that is separated from the connection unit at the second load,
Degressive load limiter. delete delete According to claim 1,
The connection area is
Characterized in that the wire unit is formed long in one direction from the other end of the connection unit so that the wire unit can be drawn in or removed from the other end of the connection unit.
Degressive load limiter. According to claim 4,
The connection area is
Characterized in that it is spaced apart from each other at predetermined intervals along the outer circumferential surface of the connection unit,
Degressive load limiter. delete According to claim 1,
The road form member,
Characterized in that, while moving to the other side of the connection unit along the connection area under the first load, it is separated from the connection area under the second load.
Degressive load limiter. According to claim 7,
The road form member,
Characterized in that it is formed long along the longitudinal direction of the connection area and provided in a symmetrical form with respect to the fixing member.
Degressive load limiter. According to claim 8,
The fixing member is
Characterized in that it has a length in a direction perpendicular to the longitudinal direction of the rod form member and is inserted into the spool, and the rod form member is connected to both ends.
Degressive load limiter. According to claim 1,
The wire unit,
Characterized in that it further comprises a guide member for preventing the fixing member from being separated from the spool by the rod form member being separated.
Degressive load limiter.

Images