JP2001001861A - Through-anchor for seat belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excellent winding state when a belt is wound up, pro vide an excellent operating feeling when the bet is extracted, and hold a suffi cient strength by using a resin with excellent slidability for a belt slot part to make it difficult for the belt slot part to be deteriorated resulting in resin cracking even if the belt is used for long time. SOLUTION: An elongated hole is provided in a metal plate 2 approximately at the center part of the lower end part thereof. The lower part below the elongated hole in the lower end part forms a lower edge 2', and the upper part above the elongated hole forms the upper edge thereof. The metal plate 2 is used as a core material, the lower end part is covered with a resin coating 8, the elongated hole covered with resin forms a belt slot, and a resin coating 6' is formed on the lower edge 2' elongated hole side using a resin with excellent slidability. Then, a resin coating 7 is formed on the resin coating 8 and other portions including the outer periphery of the lower edge 2' using a resin with high mechanical strength.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a through anchor for a vehicle seat belt, and more particularly, to a metal plate in which a lower end portion is covered with a resin. The present invention relates to a through anchor for a seat belt in which a metal plate is covered with a resin having good slidability and other portions including an outer periphery of a lower end portion of a metal plate are covered with a resin having high mechanical strength.

[0002]

2. Description of the Related Art Conventionally, a vehicle is provided with a seat belt device for holding an occupant or the like (here, a driver is described) in a collision so that the occupant does not jump out of a seat. The seat belt device usually uses a synthetic fiber thin and tough belt, and passes one end of the belt through a through anchor that is swingably fixed to the upper part of the center pillar immediately behind the seat. It is fixed to a retractor so that it can be wound up, and the other end of the belt is fixed to a bolt provided on the floor on the center pillar side of the seat via an anchor plate. Buckle that extends from the floor on the other side of the seat and secures, so that one of the folded belts passes through the flank of the body and passes over the shoulder, and the other of the folded belts passes over the knee from the flank to the knee. , So that the occupant or the like can be safely held in the seat. Therefore, when attaching or detaching the seat belt, the belt can slide freely in the belt slot in the through anchor, and the belt is damaged by the belt slot in the through anchor when an impact occurs, and furthermore, the metal plate is exposed by breaking the belt slot. It is important not to cut it off. For this reason, the lower end of the metal plate which forms the core of the through anchor is coated with a hard-to-break resin, and the coated long holes form belt slots. However, if the seat belt is used repeatedly for a long period of time, it becomes difficult for the belt to slip in the belt slot due to dirt and the like,
There arises a problem that the winding property at the time of belt winding and the operational feeling at the time of belt pulling are reduced. Also, if the lower end is insert-molded so as to wrap the metal plate only with a resin such as polyacetal,
Deterioration such as cracks is likely to occur in the outer peripheral portion of the metal plate, particularly in the edge portion, and there is a problem that the occupant cannot be reliably held in the event of a collision.

As an example of a conventional through anchor, as shown in FIG. 1, a through hole 17 through which a bolt penetrates is provided at an upper end portion, and a belt 10 through which a belt 10 is inserted at a free end side (a lower end portion). Slot 9 forming slot 5 (see FIG. 5)
The outer surface on the free end side of the metal plate 2 is integrally molded with a resin having high mechanical strength and is covered with a resin coating 8. That is, the belt slot 5 through which the belt 10 is inserted
By forming the lower edge side sliding surface with the resin coating 8, the sliding of the belt 10 can be made smooth to some extent, and the sliding resistance of the belt 10 in the through anchor at the time of pulling out the belt and winding the belt can be reduced. I have. However, since the through anchor must securely support the belt tension to the vehicle body via the metal plate 2 in the event of a vehicle emergency, a high load acts on the resin coating 8 on the lower edge side sliding surface. Become. The resin coating 8 covers the edge of the metal plate 2 facing the lower edge of the belt slot 5 so that the belt
Since it is necessary to prevent the edge of the belt 10 from coming into contact with the metal plate 2 by increasing the folding angle of 0, the synthetic resin used for the resin coating 8 does not deform when a load is applied. It is necessary to use a resin having sufficient mechanical strength. However, in general, a resin having high mechanical strength does not have good slidability, and a resin having a small friction coefficient and good slidability has low strength. Therefore, slidability has been sacrificed to obtain sufficient strength. Therefore, the slidability of the belt 10 cannot be said to be good, and there has been a problem that the winding property at the time of belt winding and the operational feeling at the time of pulling out the belt are not good.

Another example of a conventional through anchor is disclosed in Japanese Utility Model Laid-Open No. 4-130568, as shown in FIG.
, The outer surface on the free end side of the metal plate 2 is covered with a resin coating 8 integrally molded, and the resin coating 8 is a lower layer 3 made of a resin having high mechanical strength.
And an upper layer 4 made of a resin that covers the lower layer 3 and has low frictional resistance and good slidability. A polyolefin resin or a fluororesin is used as the resin having a small friction coefficient and good slidability used for the upper layer 4. However, in this method, in order to provide the lower layer 3 with sufficient strength and prevent the sliding surface from cracking, the whole becomes too thick or the polyolefin resin does not have good slidability. However, fluororesins are expensive and difficult to integrally mold. Furthermore, the combination of a polyolefin or a resin with a fluororesin has a problem that the adhesion at the interface between the lower layer 3 and the upper layer 4 cannot be improved.

[0005]

That is, an object of the present invention is to use a resin having good slidability in a belt slot,
By providing a through-belt anchor for seat belts that is less likely to deteriorate such as resin cracks even when used for a long period of time, has a good winding property when winding the belt and a good operation feeling when pulling out the belt, and maintains sufficient strength. is there.

[0006]

Means for Solving the Problems The inventors of the present invention insert a metal plate serving as a core material and a resin into a through-hole for a seat belt by insert molding to form a belt slot portion with a slidable material such as polyacetal. Using good resin,
The other parts are insert-molded using a resin having high mechanical strength, so that the belt can slide smoothly even after long-term use, and a through anchor for a seat belt with less deterioration such as cracks in the resin part can be obtained. This led to the completion of the present invention.

That is, the first aspect of the present invention is a metal plate 2
At the center of the lower end of the metal plate 2 is a metal plate 2 having a lower edge 2 'below the elongated hole 9 at the lower end and an upper edge 2 "above the elongated hole 9 as a core material. The lower end portion is covered with a resin coating 8, and the resin-coated long hole 9 forms a belt slot.
Is provided by molding using a resin (A) having good slidability, and the other portion of the resin coating 8 including the outer peripheral side of the lower edge 2 'is made of a resin (B) having a high mechanical strength. And a resin coating 6 and a resin coating 7 are connected to each other with a boundary therebetween. A second feature of the present invention is that the entire inner periphery of the long hole 9 includes the resin coating 6 including the lower edge 2 ′ and the upper edge 2 ″ of the metal plate 2. A third aspect of the present invention provides a through anchor according to the first aspect of the present invention, wherein the resin (A) is a polyacetal resin and the resin (B) is a nylon resin or a polybutylene terephthalate resin. 2 is provided.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. 3 and 5 show an example of the seat belt through anchor of the present invention. FIG. 5 is a plan view of the through anchor of the present invention. FIG. 3 is a sectional view (longitudinal sectional view) taken along a line AB in FIG. (Note that FIGS. 1 to 4 are the same vertical sectional views.) The through anchor 1 for a seat belt has a core made of a metal plate 2, and the metal plate 2 has a bolt penetrating the upper end portion. A hole 17 is provided and is swingably bolted to the upper part of the center pillar immediately after the seat. At the lower end of the metal plate 2, there is provided a slot 9 for forming a belt slot 5 through which the belt 10 is inserted.
The lower plate portion is referred to as a lower edge 2 ′, and the upper plate portion is referred to as an upper edge 2 ″ (in FIG. 5, the lower end portion of the metal plate is indicated by a broken line). It is covered with a resin coating 8, and the resin coating 8 includes a resin coating 6 that covers the inner peripheral side of the elongated hole 9 and a resin coating 7 that covers the outer peripheral side of the lower end of the metal plate. 6 is provided so as to wrap around the long hole side of the lower edge 2 ′ and the upper edge 2 ″ of the metal plate, and the belt slot 5 is formed. The resin coating 7 is provided so as to wrap the outer peripheral side of the lower edge 2 'and the upper edge 2 "of the metal plate. The resin coating 6 and the resin coating 7 are connected to each other by molding and smoothly connected, and are substantially uniform. 3 or 4 show a state near the boundary between the resin coating 6 and the resin coating 7. That is, the cross section at the boundary between the resin coating 6 and the resin coating 7 has substantially the same cross-sectional area. However, the thickness of the cross section is the same even at a portion slightly distant from the boundary surface, but at a portion far from the boundary surface, the resin coating 6 and the resin coating 7 are provided.
May have different cross-sectional shapes and thicknesses.

The resin coating 6 forms the belt slot 5,
Since the belt 10 comes into contact with the metal plate 2, the resin (A) having good slidability is provided around the long hole 9 of the metal plate 2 by primary insert molding. Using the primary insert molded product, the other portion of the lower end of the metal plate 2 is subjected to secondary insert molding with a resin (B) having high mechanical strength to provide a resin coating 7. There is no restriction on the order of the formation of the resin coating 8.
Next, after insert molding, resin coating 6 with resin (A)
May be subjected to secondary insert molding, or both may be used simultaneously for insert molding.

Examples of the resin (A) having good slidability include polyacetal and polybutylene terephthalate.
Preferably it is a polyacetal. As the resin (B) having high mechanical strength, polyamide such as various nylons,
Examples thereof include polybutylene terephthalate, polyethylene terephthalate, and polypropylene with a reinforcing material. In particular, when the polyacetal is used as the resin (A), not only the slidability is good, but also the polyacetal has sufficient strength even when a large force is applied to the resin coating 6 by the belt 10 at the time of collision or the like. Further, even if the temperature inside the vehicle is repeatedly changed for a long time from a low temperature in winter to a high temperature in summer, even if the resin coating 6 repeatedly shrinks and expands, the resin coating 6 may be elongated.
The inner periphery of the metal plate is not wrapped around the metal plate on the lower edge 2 ', so that the risk of cracks due to creep of the resin is greatly reduced. On the other hand, the resin coating 7, which is the other part of the resin coating 8 other than the resin coating 6,
Metal plate 2 including shoulder 2 '''of metal plate 2
It is not necessary to use a resin having good slidability because the outer periphery of the lower end of the resin is covered with the resin (B). Used to prevent deterioration such as generation of cracks due to creep.

FIG. 4 shows another example of the through anchor for a seat belt according to the present invention. When the seat belt is worn, only the portion where the belt 10 comes into contact with the belt slot 5 (that is, the lower edge 2 'side) is covered with the resin coating 6. This is an example in which is provided.

The thickness of the resin coating 6 on the plate surface side is 1.5 to
7 mm, preferably 2 to 5 mm;
It is 5 to 6 mm, preferably 2 to 4 mm. When the thickness is smaller than the above range, the resin is easily broken at the time of impact. The thickness of the resin coating 7 on the plate surface side is the same as the thickness of the resin coating 6 on the plate surface side,
Outer edge side thickness is 1.5 to 8 mm, preferably 3 to 5
mm. When the thickness is smaller than the above range, the resin is easily broken at the time of impact, and when too thick, it is not economical. The depth of the resin coating 6 at the lower edge 2 ′ or the upper edge 2 ″ on the plate surface side (indicating the entire thickness of the portion that covers the front and back of the metal plate) is 5 to 20 mm, preferably 7 to 15 mm.

In FIG. 3 or 4, for example, when the resin (A) is firstly insert-molded around the long hole 9 of the metal plate 2 and then the resin (B) is secondarily insert-molded, It is preferred that the interface between A) and the resin (B) is in good contact. For this reason, if the melting point of the resin (B) is higher than that of the resin (A), the interface between the resin (A) and the resin (A) will adhere to each other because the interface of the resin (A) slightly melts during the secondary insert molding. easy. A step is provided on the surface of the mold when the resin (A) is subjected to the primary insert molding, and a primary insert molded article having a step at a portion to be an interface is produced, and then a secondary insert is formed by the resin (B). When the insert molding is performed, the boundary surface is easily melted by the steps provided in the resin coatings 6 and 7 (see FIG. 3), and it is hard to be mechanically displaced.
The height of the step is 20 to 80%, preferably 50% of the coating thickness. The step length of the step is 15 to 100% of the coating thickness. In addition, a pattern for crimping was applied to the surface of the mold when the resin (A) was subjected to the primary insert molding, and a portion (see FIG. 4) to be an interface between the resin coatings 6 and 7 was provided. After the primary insert molded product is manufactured, the secondary insert molding is performed using the resin (B).
The interface is easily melted and hardly displaced mechanically. In the above example, the interface between the resin coatings 6 and 7 is perpendicular to the metal plate surface, but the resin (A) is provided on the metal plate surface so as to form an inclined surface, and the inclined surface forms the interface. As described above, the resin (B) can be provided by molding. A step or a grain may be provided on the slope to make the boundary surface easier to melt and mechanically less likely to shift. In this case, there is an effect that the boundary surface is widened. Alternatively, the resin coating 7 may be provided by molding so as to partially cover the layer of the resin coating 6 in a tapered shape. Furthermore, a socket-shaped resin coating 7 having a uniform thickness of the resin coating 6 stored therein may be provided by molding. In this case, the resin coating 7 is provided on the resin coating 6 with a step.

In order to improve the adhesion at the interface between the resin (A) and the resin (B), after the resin (A) is subjected to the primary insert molding, an adhesive layer is provided at least at a portion to be the interface, and then the resin (A) B) may be subjected to secondary insert molding. In particular, when the adhesion between the resin (A) and the resin (B) is low, it is desirable to provide an adhesive layer. The adhesive layer is a known material, apparatus, and method that is generally used, such as surface roughening treatment such as blasting and frame treatment, activation treatment with ultraviolet light or plasma, and primer treatment for applying a coupling agent or an adhesive solution. Can be provided in combination.

[0015]

EXAMPLES The present invention will now be described specifically with reference to examples, but the present invention is not limited to these examples. [Example 1] As a metal plate, a thickness of 3 mm, a maximum width of 85 mm, and a height of 10 m of a resin-coated portion at a lower end portion
m, a hole provided with a long hole (length 65 mm, width 10 mm) was used after making the outer periphery and the inner periphery of the long hole a smooth curve and chamfering the edge in the thickness direction. As the resin (A), DURACON ^™ M25-44 (manufactured by Polyplastics Co., Ltd., polyacetal resin) was used. As the resin (B), DURANEX ^™ 3306 (polybutylene terephthalate resin manufactured by Polyplastics Co., Ltd.)
It was used. A stepped mold is attached to the injection molding machine, a metal plate is set in the mold, and the resin (A) is injected at a resin temperature of 200 ° C., and an outer length of 70 mm and a thickness around the long hole of the metal plate. 3mm, 3mm covering depth from belt slot surface to metal plate, 1.5m step height
m, a primary molded product having a step height of 1.5 mm was obtained. Next, the primary molded product was set in another mold, and the resin (B) was injected at a resin temperature of 250 ° C. to cover another portion of the lower end of the metal plate. The through anchor thus obtained was used for a three-point seat belt of an automobile. Even if the through anchor is left at 100 ° C. for 2,000 hours, no abnormalities such as cracks are observed, and even through 100,000 operation tests, it is possible to obtain a through anchor with good sliding properties.

The seat belt through anchor of the present invention can be applied to various parts of the seat belt, and is not limited to the one provided on the center pillar, and is not limited to the one for guiding the belt wound up by the retractor. is there.

[0017]

According to the present invention, it is possible to obtain a through anchor for a seat belt which has a good winding property at the time of winding the belt and a good operation feeling at the time of pulling out the belt even when used for a long time, and is hardly cracked.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an example of a conventional through anchor.

FIG. 2 is a longitudinal sectional view of another example of a conventional through anchor.

FIG. 3 is a longitudinal sectional view of an example of a through anchor according to the present invention.

FIG. 4 is a longitudinal sectional view of another example of the through anchor of the present invention.

FIG. 5 is a plan view of an example of a through anchor according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 through anchor 2 metal plate 2 'lower edge 2 "upper edge 2'" shoulder 3 lower layer 4 upper layer 5 belt slot 6 resin coating 7 resin coating 8 resin coating 9 slot 10 belt

Claims (3)

[Claims] An elongated hole (9) is provided substantially at the center of the lower end of the metal plate (2), and a lower edge (2 ') is formed below the elongated hole (9) of the lower end, and the elongated hole (9) is formed. A metal plate (2) having an upper edge (2 ") at the top of the metal plate (2) is used as a core material, and the lower end is coated with a resin coating (8), and a long hole (9) coated with resin is formed. In a through anchor for a seat belt forming a belt slot, a resin coating (6) is provided on at least the long hole side of the lower edge (2 ′) by molding using a resin (A) having good slidability. The resin coating (7) is provided on the other portion of the resin coating (8) including the outer peripheral side of 2 ′) by molding using the resin (B) having high mechanical strength, and the resin coating (6) and the resin coating ( 7) A through anchor, wherein the anchors are connected at the border. 2. The entire inner periphery of the long hole (9), including the long side of the metal plate (2), including the lower edge (2 ′) and the upper edge (2 ″), forms a resin coating (6). The through anchor according to claim 1, wherein: 3. The through anchor according to claim 1, wherein the resin (A) is a polyacetal resin, and the resin (B) is a nylon resin or a polybutylene terephthalate resin.