JP2021003920A - Headrest stay - Google Patents

Abstract

To solve the problem in which all portions of a headrest stay has the same cross-sectional structure and most of the portions has excessive specifications for the required bending strength, which causes waste of materials and high cost.SOLUTION: For a pair of left and right legs for a headrest stay, an area for a predetermined length of sliding portions of support opening ends has a double pipe structure. Bent portions of a bridge have a double pipe structure. Inner pipes are inserted into these portions and secured in a crimped manner. For each leg and the bridge of the headrest stay, it is possible to select any member that suits the function and required strength so that cost and quality advantages for the headrest stay can be provided.SELECTED DRAWING: Figure 1

Description

The present invention relates to an improvement in a headrest stay, specifically a headrest headrest that is attached to the seat back of a vehicle seat.

A headrest (head backward tilt deterrent device) is provided above the seat back of an automobile (vehicle) seat to protect the head of a seated occupant. This headrest houses a bag-shaped epidermis, which is the exterior material of the pillow part where the seated occupant's head hits, a substantially inverted U-shaped headrest stay in which a bridge part is arranged in the internal space of the epidermis, and this bridge part. It is formed from urethane foam (cushion body) filled in the internal space of the epidermis in the state. A pair of left and right legs extending downward from both ends of the bridge portion of the headrest stay protrude from the lower surface of the pillow portion. Each of these legs is fitted into a pair of tubular supports that are vertically fitted to the seat back, and by adjusting the hooking position of a notch (notch groove) formed on the outer surface of one leg. , The headrest is provided so that it can move up and down.

The conventional headrest stay is made of resin, for example, as in Patent Document 1, in which one metal pipe is bent into a substantially inverted U shape and its legs (straight line portion) are opened at the upper end of the seat back. It is configured to be inserted into the support.

JP-A-2002-11524

However, the headrest stay described in Patent Document 1 is a single metal pipe having a perfect circular cross section bent into a substantially inverted U shape. That is, the maximum external force acts on the headrest stay at the portion protruding from the opening of the support during driving, especially when the brake is suddenly activated. Therefore, the material, size, etc. of the pipe were designed according to the bending strength of this part. As a result, metal pipes having excessive strength, excessive material, etc. as a whole have been used. In other words, the weight of the headrest stay as a whole was large and the cost was high.

Therefore, as a result of diligent research, the inventor found that the bending strength acting during operation differs between the bridge portion of the headrest stay embedded in the urethane foam (foam) of the pillow portion and the support opening contact portion of the leg portion. Therefore, it was found that the weight and cost can be reduced as a whole by reinforcing only the part where a large external force acts. Therefore, regarding the headrest stay, it was decided to reinforce the part where the external force acting is large, the sliding contact part at the support opening end, and the bent part have a pipe double pipe and triple pipe structure. As a result, it was found that it is possible to arbitrarily select a member suitable for the required function and strength for the leg and the bridge, which gives an advantage to the quality and cost of the headrest stay. And completed this invention.

That is, according to the present invention, in the headrest stay, a member suitable for the function and strength required in each part can be arbitrarily selected, thereby giving an advantage to the quality and cost of the headrest stay and the headrest stay thereof. It is intended to provide a manufacturing method.

The invention according to claim 1 is a pair of left and right headrest stays used for a headrest of a seat back of a vehicle, which is made of a straight metal pipe and is movably inserted into the support of the seat back. It is provided with a leg portion and a bridge portion formed in a substantially inverted U shape by bending a straight metal pipe and connected to each of the upper end portions of the pair of left and right leg portions, and the pair of leg portions. The portion of the headrest stay that is inserted into the support and is in sliding contact with the open end thereof is a headrest stay formed by inserting a metal inner tube into the support to form a double tube structure.
The portion that is in sliding contact with the open end of the support is a portion that is formed linearly in the leg portion and is at least 8 to 10 cm above the uppermost notch (this 8 to 10 cm is the uppermost notch). It means the length range of the forming portion of the lowermost notch). Of the pair of legs, the leg portion in which the notch is not formed has a range corresponding to a length of 8 to 10 cm from the uppermost notch in the notch-forming leg portion. The range of the sliding contact portion is a length range corresponding to between the uppermost and lowermost stages of the plurality of notches. This is because the height of the headrest is adjusted by the notch.
As for the part to be a double pipe, in addition to the sliding contact part to the support (grommet), the bent part of the leg and the bridge part, and the headrest stay is made of two straight pipes (leg part). ) And the inverted U-shaped bent bridge portion are joined to form a single pipe, and the butt joint portion can also be reinforced by forming a double pipe structure. The butt joint may have a triple pipe structure. This is because it is considered to be the weakest part against external force.
The inner pipe may be a metal pipe made of the same material as the outer pipe (entire headrest stay) or a different material. The former is preferable for caulking.

Vehicles are, for example, automobiles, trains, trains, airplanes, ships, and the like.
The type, shape and size of the seat are also arbitrary as long as they have a headrest on the seat back.
The structure of the headrest stay is arbitrary as long as it has a bridge portion embedded in the pillow portion and a pair of left and right legs connected to both ends of the bridge portion.
The shape of the headrest stay is, for example, a substantially inverted U-shape (when the headrest is attached to the seat back) when viewed from the front, but includes a substantially U-shape. The side view shape is arbitrary.

The material of the headrest stay that constitutes the bridge and legs is a metal pipe. The cross-sectional shape, diameter, material, and wall thickness are arbitrary. Of these, the shape of the bridge portion made of the pipe material is, for example, a substantially inverted U shape including a substantially U shape. In the case of the legs, the portion that is in sliding contact with the open end of the support (the portion extending over a predetermined length), the connecting portion with the bridge portion (continuous portion), and each bent portion (curved portion) of the bridge portion are The inner pipe of the metal pipe is inserted to reinforce the outer pipe of this insertion part. Since it is composed of a double pipe and its section modulus is large and highly rigid compared to the non-inserted part, for example, when the vehicle is suddenly stopped, the head of the seated occupant hits the pillow part and is large in the above-mentioned part of the bridge part. Even if a bending moment acts, the bridge portion is not easily deformed.

The material of the straight pipe (metal pipe) constituting the headrest stay including the bridge portion and the leg portion is arbitrary as long as the unreinforced portion is made of a metal having strength as a headrest stay. For example, various steel pipes.

The thickness (outer diameter) of this metal pipe is arbitrary. For example, it may be 10 mm to 20 mm.
A plurality of notches are formed in at least one of the two legs at a predetermined pitch in the length direction. These notches are hooked with hooking claws of an adjusting mechanism that adjusts the height of the headrest from the seat back.
The thickness of the metal pipe material is arbitrary (2 mm to 1.5 mm).

Further, the inner pipe inserted into the bent portion and the support opening sliding contact portion must be a metal pipe having a diameter that can be inserted (including press-fitting) into the metal pipe (outer pipe) constituting the stay. There is. The wall thickness and the length of the pipe are arbitrary. The material is preferably the same as the outer pipe, for example, stainless steel or steel.
Here, the support (grommet) is composed of a cylindrical member (resin) having a predetermined length, is installed in the upper part of the seat back, and the upper end opening thereof opens on the upper surface of the seat back. In the headrest stay, the pair of left and right legs are inserted into this support and the portion of the predetermined height range that slides in contact with the open end is the part where the maximum external force acts on the sliding contact of the open end. It is reinforced with heavy pipes. As for the bridge portion, the bent portion is reinforced by the inner pipe.

The bridge and each leg are manufactured by bending one pipe, but these are divided into three parts and three pipes (two straight pipes and an inverted U-shaped pipe) are connected. It can also be. In this case, the connection structure is arbitrary. For example, a fitting structure (press-fitting structure) between pipes that is performed by reducing or expanding the diameter of the corresponding end, and an inner pipe that has the same pipe diameter, that is, a sleeve that is formed by internally mounting a connecting sleeve at each connecting part. It may be a mating structure. Further, a screw structure may be used.
In order to further increase the connecting strength, caulking or spot welding can be performed on each connecting portion (in the case of a sleeve, each sleeve). The caulking process can be spot caulking in which a plurality of locations are pressed in the circumferential direction and the axial direction.

The invention according to claim 2 is the headrest stay according to claim 1, wherein the pair of legs and the bridge are connected in a butt state, and the inner tube is inserted into the connecting portion. is there.
That is, instead of manufacturing the headrest stay with one pipe, a three-divided structure consisting of two straight pipes and one inverted U-shaped pipe was formed and these were connected. No, these three pipes are made of the same material and have the same diameter. In this case, a triple pipe structure is preferably used in which the outer pipe is fitted to the butt connecting portion. This is for reinforcement.

In addition, the connecting portion between each leg and the bridge portion and the bent portion provided on the bridge portion have a cross-sectional shape that is wider in the front-rear direction (of the seat) than in the left-right direction (of the vehicle seat). (The cross section is oval) is preferable because of high rigidity. This means that the length of the connecting part in the front-rear direction should be longer than the length in the left-right direction so that the cross-sectional coefficient becomes larger than when the straight pipe is left as it is or when the left-right direction is widened. means. This is effective as a method for increasing the rigidity of the connecting portion of the thinned bridge portion, for example, without using a sleeve.
As a method of attaching the connecting portion between the leg portion and the bridge portion to such a shape, for example, caulking is adopted.
Further, among the bridge portions, the end portion on the connecting side with the leg portion must have a diameter that can be connected to the leg portion by, for example, reducing or increasing the diameter.

The caulking process can also be performed using a caulking machine or a caulking tool. An automatic caulking device that applies a caulking force to the target site by an actuator is suitable.

The invention according to claim 3 is the headrest stay according to claim 1 or 2, wherein the inner pipe is fixed to a part of the headrest stay into which the inner pipe is inserted by caulking.
Spot caulking is preferable, and for example, it is also preferable to perform spot caulking at a plurality of locations in the axial direction and at a plurality of locations in the circumferential direction at equal intervals to prevent omission.

In the invention according to claim 4, in the method for manufacturing a headrest stay including a pair of legs and a bridge, a step of preparing a metal pipe made of one straight pipe and a step of preparing the metal pipe of the metal pipe. By inserting the inner pipes of a plurality of metal pipes shorter than the metal pipes at a plurality of positions, and by caulking the portion where the inner pipes are inserted with the metal pipes, the metal is formed. The process of fixing the pipe and the inner pipe, and then by bending the metal pipe into a substantially U shape, the bent portion and / or the metal pipe extends linearly and is inserted into the support of the seat back. This is a method for manufacturing a headrest stay in which the caulked inner pipe is positioned at a portion located at the opening of the support.
The headrest stay manufactured in this manner is used for manufacturing the headrest according to the following procedure.
That is, a predetermined inverted U-shaped headrest stay is produced by subjecting a single metal straight pipe to a predetermined bending process. This headrest stay is provided with a pair of left and right legs extending in parallel in a straight line and an inverted U-shaped bridge portion connecting them.
Therefore, a cushion body is provided around the bridge portion so that the bridge portion is embedded. That is, the epidermis (bag) is covered so as to surround the bridge portion, the legs are projected from the epidermis, and the cushion body (urethane foam) is expanded in the space inside the epidermis.
At this time, an inner pipe (the same metal pipe having a small diameter and can be inserted) is inserted into a predetermined position of one pipe, for example, a bent portion or a sliding contact portion of a support opening end (a position within a predetermined length range from both ends of the pipe). Is inserted. Then, the inserted inner pipe is fixed so as to be integrated with the outer pipe by caulking.

The headrest stay according to claim 1 is made of a straight metal pipe and has an inverted U shape. That is, a bridge portion bent or curved in an inverted U shape connects a pair of left and right leg portions extending in parallel in a straight line in a bridging state. At this time, the sliding contact portion within a predetermined length range that is inserted into the support of the seat back with the pair of legs and is in sliding contact with the open end thereof is reinforced by an inner pipe so as to have a double pipe structure. As a result, the metal pipe constituting the entire headrest stay can be made thinner (compared to the conventional single pipe stay), and the weight and cost can be reduced as a whole. .. The support opening end sliding contact portion whose inner pipe is reinforced by caulking can maintain sufficient strength against an external force acting in the event of an accident or the like as in the conventional case.
In addition, it is not limited to the double pipe, and it is also possible to have a triple pipe structure for a specific part. It can also exert a reinforcing effect.

In the headrest stay according to claim 2, in addition to bending one straight pipe, the leg portion and the bridge portion can be divided and formed into a plurality of headrest stays. In that case, the connecting portion between the leg portion and the bridge portion is butt-joined, and by inserting and caulking the inner pipe at this butt portion, the strength against the connection can be increased. Higher strength can be achieved than simply expanding one of these coupling ends and inserting the other end into the expanding section. It should be noted that it is also effective from the viewpoint of reinforcement that the relevant part has a triple pipe structure.
By dividing the headrest stay into three parts, it is possible to increase the degree of freedom in designing the headrest stay, such as plating or non-plating each part and changing the material.

In the headrest stay according to claim 3, since the inner pipe is fixed to a part of the headrest stay into which the inner pipe is inserted by caulking, the position of the inner pipe does not move due to bending or the like. .. The inner tube can be held in an appropriate position (bending part, etc.) of the stay. The caulking process is preferably spot caulking, but may be another caulking process that changes the cross-sectional shape. This is because the cross-sectional coefficient of the portion is increased by inserting the inner pipe and is reinforced against bending.

In the method for manufacturing a headrest stay according to claim 4, starting from cutting one pipe to an appropriate length, a pipe having a predetermined length and a small diameter of the same quality is inserted (press-fitted) as an inner pipe. It is fixed in place on the outer pipe by caulking. Then, since the bending process is performed after this, the movement of the inner pipe during the bending process can be prevented, and the reinforcement can be performed as set. It is preferable to perform plating after inserting the inner tube and before bending.

It is a perspective view which shows the headrest stay which concerns on Example 1 of this invention. It is a top view (A) which shows the bent part which is a part of the headrest stay which concerns on Example 1 of this invention, and is the sectional view (B) by the line AA. It is a top view (A) which shows the bent part which is a part of the headrest stay which concerns on Example 2 of this invention, and is the sectional view (B) by the line BB. It is a top view (A) which shows the bent part which is a part of the headrest stay which concerns on Example 1 of this invention together with a support, and is the sectional view (B) by the line AA. It is a plan view (A) which shows the bent part which is a part of the headrest stay which concerns on Example 2 of this invention together with a support, and is the sectional view (B) by the line AA.

Hereinafter, examples of the present invention will be specifically described with reference to the drawings. Here, for convenience of explanation, the left-right direction is the width direction of the seat of the vehicle, and the front-rear direction is the front-rear direction of the seat.

In FIG. 1, 10 is a headrest stay according to the first embodiment of the present invention. The headrest stay 10 is used as a component of the headrest of the seat back of an automobile seat. The headrest stay 10 has a substantially inverted U shape by bending one metal pipe when viewed from the front. This straight metal tube (a perfect circular cylinder with a constant cross section) is cut from the raw material to provide a desired length, and then the end portion is chamfered to determine one end (straight portion). Multiple notches are applied only to the positions. After that, plating treatment such as dobu-zuke is performed, and then it is bent into an inverted U shape by bending (using a processing machine). The pair of legs 11 and 12 are extended in a straight line, and each is inserted into the pair of supports of the seat back. The legs 11 and 12 are connected or connected by a bridge portion (inverted U-shaped portion) 14.
Therefore, the headrest stay 10 has a pair of left and right legs 11 and 12 and a bridge portion 14 made of a stainless steel pipe that connects the upper ends of the legs 11 and 12 to each other. Further, a plurality of notches (notch grooves) 13, 13 ... Are formed in one leg portion 12 at equal intervals in the length direction thereof.
In the headrest stay 10, a metal pipe is used as an outer pipe, and a plurality of inner pipes 15, 15 ... Are inserted and fixed in a part of the outer pipe. There are 6 inner tubes as a whole, 2 at the upper ends of the legs 11 and 12 which are straight parts (meaning the upper part from the support opening after insertion into the support), and legs 11 and 12. Two are arranged and fixed symmetrically, two in the bent portion near the boundary with the bridge portion 14, two in the bent portion of the bridge portion 14 at 90 degrees, and six in total. All inner pipes 15 are fixed to the site by caulking.
When the headrest stay 10 which is an outer pipe is a metal pipe having a predetermined diameter and its wall thickness is constant, the inner pipe 15 is formed of a homogeneous material and the diameter is large enough to be inserted in close contact with the outer pipe 10. It is set. The inner pipe 15 fitted in the continuous portion (including the bent portion) between the leg portions 11 and 12 and the bridge portion 14 has a linear portion that is in sliding contact with the opening end of the support.

2 (A) and 2 (B) and 4 (A) and 4 (B) show a part of the headrest stay according to the first embodiment of the present invention. The latter is a diagram for explaining the positional relationship with the support 21. In these figures, it is shown that the portion having the double pipe structure is the portion that is in sliding contact with the open end of the support 21 and has a length range of 8 to 10 cm from the uppermost notch (in the leg without notch). The same length range at the same position as this is a double pipe). This is because the portion of the headrest stay 10 on which the largest load (external force) acts during a collision with a vehicle or the like, or during braking, is a portion that slides (contacts) with the open end 21A of the support 21.

FIG. 2 is a diagram for more specifically explaining the bent portion of the double pipe structure.
In the figures (A) and (B), only a part of the headrest stay 10 is shown. The inner pipe 15 extends slightly upward from the straight portion via the bent portion. The inner pipe 15 is firmly coupled to the outer pipe (stay) 10 by spot caulking at two locations sandwiching the bent portion. Spot caulking is a method of joining inner and outer pipes by applying a small machining pressure in a hole shape, and it has the characteristics that strong joining is possible, there is no anisotropy of strength, and it is not affected by the direction of force. There is. In particular, by performing spot caulking at two locations before and after the bending portion, it is possible to prevent the inner pipe from being displaced during the bending process.
Reference numerals 22 and 23 indicate a plurality of holes due to these spot caulking. As an example, these holes are arranged at two places in the circumferential direction and two places in the axial direction at equal intervals. That is, as a whole, four caulking holes are connected at two places, having a total of eight caulking holes. The number of holes, hole diameter, depth, spacing, etc. are not limited to this.
The support 21 in FIG. 4 is a resin cylinder, and is fixed to the seat back so that its upper end opens. The legs 11 and 12 of the headrest stay, which are on the headrest and project from the lower end, are inserted into the support 21 and supported so as to be vertically movable. In that case, the height of the headrest is adjusted by engaging one of the notches formed on one of the legs 11 and 12 with the claws built in the seat back.

3 (A) and 3 (B) and 5 (A) and 5 (B) show that the headrest stay 30 is not the headrest stay formed by bending one metal pipe, but the leg portion 31 and the bridge portion. This is an example of being butt-bonded with 32.
That is, the leg pipes (pipes having the same diameter and the same material) 31 and the bridge pipe 32 are abutted in front of the bent portion (the portion bent at an obtuse angle) of the bridge portion 32, and the abutted portion and the bridge portion pipe 32 are abutted with each other. The inner pipe 33 is inserted into the bent portion and is caulked. The spot holes 34 and 35 are formed at four 2 × 2 locations on the leg side and four spot holes 34 and 35 on the bridge portion side as well. As a result, the butt portion is connected and the bent portion is reinforced at the same time.
Further, in the butt joint portion, the outer pipe 40 is externally fitted to form a triple pipe structure as a whole. In this portion, the inner pipe 33, the stay 30 (31, 32) and the outer pipe 40 are integrally fixed by caulking, which contributes to further improvement in strength. The outer pipe, inner pipe, and stay are made of the same material.
It should be noted that the leg portion is separated from the bridge portion because only the leg portion is dipped and plated to suit cost reduction.

When spot caulking is not performed, various fixing methods such as spot welding, shrink fitting, and cold fitting can be carried out. It is also one of the options to use only press fitting.
Furthermore, the perfect circle can be maintained by spot-caulking the double pipe portion of the perfect circle pipe evenly from the circumferential direction, and the reinforcing effect can be achieved by increasing the cross-sectional coefficient. It is also possible to make the cross section oval by pressing the heavy pipe portion from both sides. In this case, by setting the long axis of the oval cross section in the front-rear direction of the vehicle, a further reinforcing effect is exhibited.

Each leg is slidably supported in the vertical direction via two stay holders (supports 21) on a frame built in the seat back of the seat.
Each leg is a straight pipe made of stainless steel having a diameter (outer diameter) of 12.7 mm and a thickness of 2 mm. The length of each leg is the same. Of these, a plurality of notches are formed on the inner side surface (left side surface) of one leg at a predetermined pitch in the length direction. A hook claw (not shown) included in the stay holder is hooked on these notches.
The cushion body that covers the bridge portion is a pillow-shaped cushioning block made of urethane foam.

Next, a method of manufacturing the headrest stay 10 according to the first embodiment of the present invention will be described.
First, one metal pipe (stainless steel pipe) is cut to a predetermined length. Then, a plurality of notches are processed on the part corresponding to the leg. For example, processing grooves are formed at three locations at equal intervals by a press or the like. Next, an inner pipe having a predetermined length is inserted at a predetermined position of the stainless steel pipe, which is a long pipe, for example, at a position behind the notch forming portion. Next, spot caulking is performed at this inner pipe insertion position to fix the inner pipe to the outer pipe. Further, a predetermined bending process is performed. As a result, a headrest stay having a substantially inverted U shape is obtained. The edges are chamfered and plated.
In the headrest stay 10 manufactured in this way, the bridge portion is inserted into the skin (plastic bag), urethane resin is foamed and integrated with the cushion body to complete the headrest.
In the completed headrest, a pair of legs protrude in parallel from the pillow part, and this will be inserted into the support of the seat back. Height adjustment is by engaging and disengaging the notch and the hooking claw.
When the butt portion is a double pipe, a triple pipe structure in which an outer pipe is externally fitted to this portion can also be used. It is also possible to produce a stay with three levels of strength, and it is possible to obtain a headrest stay with a structure corresponding to the required strength, such as making a specific part high strength and other parts relatively low strength. ..
This can be met by using a thin-walled pipe for the outer pipe, a double pipe at the position where reinforcement is required, and a triple pipe structure for the support opening.

That is, the headrest stay is formed into a substantially inverted U shape by shaping a metal straight pipe by bending it. That is, it has a pair of legs to be inserted into the support and a bridge portion connecting them.
Then, a part of this headrest stay has a double pipe configuration. A double pipe structure is adopted for the bent part (curved part) and the sliding contact part at the support opening end (the length range corresponds to the notch installation range). In addition, in the split stay where the legs are separate from the bridge, the joint is a double pipe configuration.
The bending strength of the metal pipe as a whole is divided into large, medium, and small, and appropriate reinforcement is performed. The purpose of this is to eliminate unnecessary high-strength parts and maintain appropriate strength.

The present invention is useful as a technique for a headrest stay attached to the seat back of a vehicle seat.

10 Headrest stay,
11, 12 legs,
14 Bridge part,
15 inner tube,
21 support.

Claims (4)

In the headrest stay used for the headrest of the seat back of the vehicle seat,
A pair of left and right legs that are made of a straight metal tube and are movably inserted into the support of the seat back, and a straight metal tube that is bent to form a substantially inverted U shape. It is provided with a bridge portion connected to each of the upper ends of the pair of legs, and also has a bridge portion.
The part of the pair of legs that is inserted into the support and slides into the open end is a headrest stay that has a double-tube structure with a metal inner tube inserted inside. The headrest stay according to claim 1, wherein the pair of legs and the bridge are connected in a butted state, and the inner tube is inserted into the connecting portion. The headrest stay according to claim 1 or 2, wherein the inner pipe is fixed to a part of the headrest stay into which the inner pipe is inserted by caulking. In the method of manufacturing a headrest stay consisting of a pair of legs and a bridge,
The process of preparing a metal pipe consisting of one straight pipe and
The process of inserting the inner pipes of a plurality of metal pipes shorter than this metal pipe into the plurality of positions of the metal pipe, respectively.
The process of fixing the metal pipe and the inner pipe by caulking the part where the inner pipe is inserted with this metal pipe,
After that, by bending the metal pipe into a substantially U shape, the bent portion and / or the metal pipe extends linearly and is inserted into the support of the seat bag and is located at the opening of the support. A method of manufacturing a headrest stay in which a crimped fixed inner pipe is positioned.

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