Seat frame for vehicle

Abstract

A seat frame for a vehicle is provided with: a pair of side arms (2) of a bottom frame (1) for supporting the buttocks and thighs of an occupant from below; and a pair of cross beams (3, 4) that connect the front and rear portions of the side arms (2), respectively. At least two S-springs (7) are stretched between the two cross beams (3, 4) [or the two side arms (2)], and a retaining member (8) is mounted between the S-springs (7). A pull wire (10) is mounted between one of the two cross beams (3, 4) to which the S-spring (7) is mounted, or one of the two side arms (2), and the holding member (8).

Description

Technical Field

[0001] The present invention relates to a seat frame for a vehicle. Background Art

[0002] Generally speaking, a vehicle seat is formed by covering a foam resin cushioning material on a metal seat frame. A seat cover is further covered on the cushioning material. The seat frame mainly includes a bottom frame that supports the buttocks and thighs of a passenger from below and a back frame that supports the upper body of the passenger from behind. The present invention particularly relates to the structure of the bottom frame.

[0003] The following Patent Document 1 discloses a typical structure of a bottom frame. The bottom frame disclosed in Patent Document 1 includes a pair of side arms constituting the two side portions, a front beam connecting the front portions of the pair of side arms, and a rear beam connecting the rear portions of the pair of side arms. A plurality of S springs (snaking springs) are stretched between the pair of side arms (see FIG. 1 ). Figure 2 ). There are also cases where a front pad is provided above the front beam (FIG. 11A of Patent Document 1). There are also cases where a plurality of S-springs are provided between the front beam and the rear beam (FIG. 11A of Patent Document 1). The bottom frame is often slidably mounted on a pair of seat rails (FIG. 11A of Patent Document 1).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-172237 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] The buttocks and thighs of the passenger are supported from below by the S springs and the cushioning material. Generally speaking, if the hardness of the S springs and the cushioning material is reduced, the riding comfort is improved. The bottom unit of the seat supports the buttocks and thighs of the passenger in a seated state from below in a wide range. However, there are times when the passenger kneels on one knee on the bottom unit to pick up luggage on the opposite seat. In this case, the passenger's weight acts in a narrow range, and the downward displacement of the seat surface is larger than the downward displacement when the passenger is sitting. That is, the downward displacement of the S spring becomes excessively large, making it difficult to pick up luggage.

[0009] An object of the present invention is to provide a vehicle seat frame capable of preventing excessive downward displacement of an S-spring and improving riding comfort.

[0010] Solutions for solving problems

[0011] The vehicle seat frame of the present invention has a pair of side arms of a bottom frame and a pair of cross beams connecting the front and rear portions of the side arms. At least two S springs are stretched between the two cross beams (or the two side arms), and a retaining member is installed between the S springs. A traction wire is suspended between the retaining member and one of the two cross beams (or one of the two side arms) to which the S springs are installed.

[0012] Effects of the Invention

[0013] According to the above-mentioned features, the riding comfort can be improved and the excessive downward displacement of the S-spring can be restricted by the pull wire. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a perspective view of a vehicle seat frame according to the embodiment.

[0015] Figure 2 It is an exploded perspective view of the excessive downward displacement limiting mechanism of the S-spring of the bottom frame in the above-mentioned frame structure.

[0016] Figure 3 It is a side view (partial cross-section) of the above-mentioned excessive downward displacement limiting mechanism. DETAILED DESCRIPTION

[0017] Hereinafter, a vehicle seat frame according to an embodiment will be described with reference to the accompanying drawings. The seat frame according to the present embodiment is a seat frame for a front seat of an electric vehicle such as a battery electric vehicle (BEV) or a hybrid electric vehicle (HEV). The seat frame has a seat frame for supporting the buttocks and thighs of a passenger from below. Figure 1 The bottom frame 1 shown in the figure and the back frame supporting the upper body of the passenger from the rear. The present embodiment is characterized in that the bottom frame 1 Figure 1 The back frame is not shown in the figure. The bottom frame 1 is covered with a foam resin cushioning material, and the cushioning material is also covered with a seat fabric. Figure 1 Cushioning materials and seat coverings are not shown.

[0018] like Figure 1 As shown in FIG. 1 , the bottom frame 1 has a pair of steel side arms 2. The side arms 2 extend forward from the inclined support point between the bottom frame 1 and the back frame. A rear beam 3 is provided at the position of the inclined support point to connect the rear portions of the side arms 2. In addition, a front beam 4 is also provided to connect the front portions of the side arms 2 (see FIG. 1 ). Figure 3 ). Although not shown in the figure, it is also Figure 3 In front of the front beam 4 shown, a front beam similar to the front beam 4 is also provided. The rear beam 3 and the front beam 4 of the present embodiment are round pipes made of steel.

[0019] The front beam 4 and the rear beam 3 are cross beams that connect the front and rear portions of the two side arms 2, respectively. A front pad 5 that supports the thighs of the passenger from below is provided above the two front beams 4. The front pad 5 is mounted on the bottom frame 1 in such a manner that the front portions of the side arms 2 are connected, and the front pad 5 is also a kind of "cross beam that connects the front portions of the side arms 2". A motor (not shown) for adjusting the sliding position of the seat, the angle of the bottom frame 1, and the tilt angle of the seat back is provided below the front pad 5.

[0020] Four S springs (serpentine springs) 7 are stretched between the rear beam 3 and the front pad 5 (i.e., between the two cross beams). In the present embodiment, the S springs 7 are made of spring steel and are stretched in the longitudinal direction of the vehicle. The S springs 7 support the buttocks of the seated passenger from below. The S springs 7 are made to convex downwardly according to the mass of the passenger, thereby improving the riding comfort. In addition, the S springs 7 reduce the vibration transmitted from the vehicle to the passenger via the seat.

[0021] The S spring 7 has a T-shaped hook 7a at its rear end and a J-shaped hook 7b at its front end. The T-shaped hook 7a is formed at the top end formed by bending spring steel in accordance with the circular cross-sectional shape of the rear beam 3. The T-shaped hook 7a is hooked on the rear beam 3 from above, so that the rear end of the S spring 7 is installed in a manner that can swing vertically relative to the rear beam 3. The J-shaped hook 7b is loosely hooked on the hole formed at the rear edge of the front pad 5. Therefore, the front end of the S spring 7 can also be installed in a manner that can swing vertically relative to the front pad 5 (a kind of cross beam). If a load acts on the S spring 7 from above, the central part of the S spring 7 bends downward, but the two ends of the S spring 7 can swing, so the flexure of the S spring 7 is not hindered, and unnecessary stress does not act on the ends of the S spring 7.

[0022] A retention member 8 is installed between two adjacent S springs 7. A cylinder is formed at both ends of each retention member 8, and both ends are respectively installed on the S spring 7 in a manner that the S spring 7 passes through the cylinder. The retention member 8 suppresses deformation of the adjacent S springs 7 in the lateral direction of the vehicle when a load is applied from above. If such separation occurs, the S spring 7 cannot properly bear the load, so such separation is suppressed by the retention member 8. The retention member 8 of this embodiment is made of resin and can be properly bent. As a result, the riding comfort is improved. In this embodiment, the two rear retention members 8 are also connected to each other (integrally formed). In addition, the retention member 8 is sometimes formed of metal such as spring steel, which is the same as the S spring 7. In this case, the metal retention member 8 is installed on the S spring 7 using a metal clip or the like.

[0023] As described above, if the hardness of the S spring 7 is too low, the passenger cannot be properly supported. If the hardness of the S spring 7 is reduced, the riding comfort can be improved. However, it is desirable to limit the excessive downward displacement of the S spring 7 in the case of the load concentration when kneeling on one knee. Therefore, in this embodiment, an excessive downward displacement limiting mechanism is provided. The excessive downward displacement limiting mechanism is implemented by tensile wires 10 suspended between the retaining member 8 and the rear beam 3 or the front pad 5 (cross beam).

[0024] The traction wires 10 can also be called tensible strings. In the present embodiment, four traction wires 10 are provided. The first one is installed between the first retaining member 8 installed between the rear portions of the two adjacent S springs 7 on the right side and the rear beam 3. The second one is installed between the second retaining member 8 installed between the rear portions of the two adjacent S springs 7 on the left side and the rear beam 3. The third one is installed between the third retaining member 8 installed between the central portions of the two adjacent S springs 7 on the right side and the front pad 5. The fourth one is installed between the fourth retaining member 8 installed between the central portions of the two adjacent S springs 7 on the left side and the front pad 5.

[0025] Each holding member 8 has a metal holding piece 9 to which the end of the pulling wire 10 is mounted in a swingable manner. Both ends of the holding piece 9 are curled into two strands. The holding piece 9 is embedded in the holding member 8 when the resin holding member 8 is formed. In addition, it is also possible not to provide a member such as a holding piece 9, but to directly mount the end of the pulling wire 10 on the holding member 8.

[0026] like Figure 2As shown, the traction line 10 of this embodiment is constructed by fixing the mounting hooks 10b to the two ends of the middle line 10a by caulking. The mounting hook 10b is a T-shaped hook. The head of the T-shaped hook is formed in a cylindrical shape. One end of the traction line 10 (one mounting hook 10b) is loosely attached to a circular mounting hole formed in the rear beam 3 or the front pad 5. The mounting hook 10b is prevented from falling off from the mounting hole by the head of the T-shaped hook. The mounting hook 10b is loosely attached to the mounting position (mounting hole) of the cross beam such as the rear beam 3 or the front pad 5, so that one end of the traction line 10 can swing vertically relative to the cross beam.

[0027] The other end of the pulling wire 10 (the other mounting hook 10b) is mounted on the end portion curled into two strands of the retaining member 9. The cylindrical head of the T-shaped hook can rotate within the curled end portion of the retaining member 9. Therefore, at the mounting position (retaining member 9) where the other end of the pulling wire 10 (the other mounting hook 10b) is mounted on the retaining member 8, the other end of the pulling wire 10 (the other mounting hook 10b) can also swing vertically relative to the retaining member 8 (retaining member 9).

[0028] The traction wire 10 is tightened when the above-mentioned excessive vertical load acts on the S spring 7, and tension acts on the traction wire 10. Tension does not act on the traction wire 10 until the traction wire 10 is tightened. That is, the traction wire 10 is a surplus length wire having a length longer than the distance between the mounting position (retainer 9) where one end thereof is mounted on the retaining member 8 and the mounting position (mounting hole) where the other end thereof is mounted on one of the cross beams (rear beam 3 or front pad 5).

[0029] The traction wire 10 (excess length wire) of the present embodiment is a flexible wire that is easily bent due to its own weight, etc., more specifically, a metal strand. That is, the middle wire 10a is formed by a metal strand. In addition, as the excess length wire, the middle wire 10a may also use a solid wire such as a piano wire. In this case, when the lower load does not act on the S spring 7, the solid wire is not made straight but made flexural. In this way, the solid wire that is not a flexible wire can function as an excess length wire. In addition, a wire formed by connecting many elements such as a chain can also function as a flexible wire. That is, the chain is not a metal strand, but can function as a flexible wire.

[0030] The vehicle of this embodiment is an electric vehicle as described above. Figure 3As shown, a battery pack 12 is mounted below the bottom frame 1. A plurality of battery modules, a battery control device, etc. are stored inside the battery pack 12, and the plurality of battery modules store battery cells. The battery pack 12 is heavy, and therefore, it is mostly arranged near the floor of the vehicle compartment in order to lower the center of gravity of the vehicle. In addition, if the amount of the battery pack is increased in order to obtain a sufficient cruising range, the height of the battery pack 12 reaches a position higher than the height of the floor of the passenger's foot space.

[0031] In this case, when the above-mentioned excessive vertical load acts on the S spring 7, there is a concern about contact between the S spring 7 and the battery pack 12. If such contact is repeated, there is a concern about damage to the battery pack 12. There may also be a case where other types of device units other than the battery pack 12 are mounted below the bottom frame 1 at a position higher than the floor of the footwell. The amplifier of the car audio and the air conditioning blow-out duct can also become such a device unit. In the case where the space under the seat is effectively utilized and the fuel tank is arranged below the floor under the seat, the fuel tank can become such a device unit. However, since the fuel tank is mounted below the floor, a bulge is formed on the floor due to the fuel tank, which protrudes upward relative to the floor of the footwell.

[0032] If a device unit such as the battery pack 12 is mounted below the bottom frame 1, the gap between the bottom frame 1 and the device unit becomes smaller. Therefore, if the vertical load is too large, the S spring 7 may contact the device unit even if the above-mentioned excessive downward displacement limiting mechanism is provided. Therefore, in this embodiment, in order to prevent the S spring 7 from contacting the device unit, Figure 3 As shown in FIG. 1 , a rubber buffer 11A is attached to the lower surface of the holding member 8 .

[0033] The cushion rubber 11A is installed at a position where the retaining member 9 is insert-molded into the retaining member 8. Figure 2 As shown, the buffer rubber 11A is also attached to the holder 9. In this embodiment, the buffer rubber 11A is attached to the holding member 8 and the holder 9 by an adhesive. The buffer rubber 11A has a semi-cylindrical shape, and its curved surface faces the device unit. By setting it in this way, even if the buffer rubber 11A contacts the device unit, the impact at that time can be mitigated.

[0034] The base frame 1 can slide on the seat rail 6 fixed to the floor as described above. Therefore, depending on the sliding position of the base frame 1, there may be a situation where the buffer rubber 11A is located at a position that is not in contact with the device unit. Therefore, in the present embodiment, a buffer rubber 11B is also installed on the upper surface of the battery pack 12 as the device unit. The buffer rubber 11B has a semi-cylindrical shape (or a hemispherical shape) similar to the above-mentioned buffer rubber 11A, and is installed on the upper surface of the battery pack 12 using an adhesive. Contact between the battery pack 12 and the S spring 7 is prevented by the buffer rubber 11B on the upper surface of the battery pack 12.

[0035] According to the vehicle seat frame of the above embodiment, the excessive downward displacement of the S spring 7 can be suppressed by the traction wire 10 suspended between the holding member 8 and the cross beam (the rear beam 3 or the front pad 5). Therefore, the hardness of the S spring 7 can be reduced to improve the riding comfort when the passenger is seated, and the excessive downward displacement of the S spring 7 caused by the excessive vertical load can be suppressed. Therefore, when the passenger kneels on one knee on the bottom unit to take the luggage on the opposite side seat as described above, the downward displacement of the seat surface does not become too large, and it is not difficult to take the luggage.

[0036] In addition, even if the above-mentioned device unit is not mounted below the bottom frame 1, there is a case where the gap below the bottom frame 1 is very small in a sedan or sports car. In such a case, there is also a concern about contact between the S spring 7 and the floor. If such contact is repeated, there is a concern about damage to the floor and damage to the S spring 7. According to the vehicle seat frame of the above-mentioned embodiment, when a device unit such as the battery pack 12 is not mounted and the gap is small, the contact between the floor and the S spring 7 can be limited.

[0037] According to the seat frame of the above embodiment, the traction wire 10 is an excess length wire having a length longer than the distance between the mounting position where one end thereof is mounted on the retaining member 8 and the mounting position where the other end thereof is mounted on one of the cross beams (the rear beam 3 or the front pad 5). That is, when the vertical load is not applied to the bottom frame 1, the excess length wire is bent or drooped, and tension is substantially not applied to the excess length wire. Tension is applied to the excess length wire only when the downward displacement of the S spring 7 becomes excessive. Therefore, it is possible to properly balance the improvement of riding comfort and the limitation of excessive downward displacement.

[0038] In the above embodiment, specifically, the excess length wire (pulling wire 10) is a soft wire. As long as the soft wire is easily bent due to its own weight, etc., it hangs down when tension is not applied, and stress is not applied to the mounting parts at both ends of the soft wire. In addition, when assembling the bottom frame 1, it is easy to install the soft wire as the pulling wire 10.

[0039] In the above embodiment, more specifically, the flexible wire (pulling wire 10, excess length wire) is a metal strand. The metal strand as a flexible wire does not lose its function even if one of the many wires constituting the strand breaks. In addition, the metal strand is formed by twisting many wires, so even if tension acts on the metal strand in an impact manner, the metal strand can use its own slight elongation to ease the impact tension and bear the impact tension.

[0040] According to the seat frame of the above embodiment, the device unit (battery pack 12, etc.) having a height higher than the floor height of the passenger's footwell is mounted below the bottom frame, and the buffer rubber 11A is attached to the lower surface of the retaining member 8. Therefore, even if the above-mentioned excessive downward displacement is restricted by the pulling wire 10, there is a possibility that the S spring 7 and the device unit will come into contact. However, even if the S spring 7 comes into contact with the device unit, the buffer rubber 11A can prevent damage to the device unit.

[0041] According to the seat frame of the above embodiment, the traction wire 10 is mounted in a swingable manner at the mounting position (retainer 9) where one end of the traction wire 10 is mounted on the retaining member 8. Similarly, the traction wire 10 is also mounted in a swingable manner at the mounting position (mounting hole) where the other end of the traction wire 10 is mounted on one of the cross beams (rear beam 3 or front pad 5). Therefore, even if tension acts on the flexed or drooping traction wire 10 and the traction wire 10 is tightened, the end of the traction wire 10 swings, and therefore, stress concentration is not generated at the mounting position of the traction wire 10. Therefore, the breakage of the traction wire 10 (intermediate wire 10a) can be prevented.

[0042] The seat frame of the present invention is not limited to the seat frame of the above-mentioned embodiment. As described above, the traction wire (excess length wire) 10 may also be a non-flexible solid wire (piano wire) or a non-flexible metal strand installed between the holding member and the cross beam in a bent state. As described above, the end of the traction wire (excess length wire, flexible wire, metal strand) 10 may also be directly installed on the holding member 8 without the aid of the holding member 9.

[0043] In the above embodiment, the metal holder 9 is insert-molded into the resin holding member 8, but the metal holder 9 may be attached to the metal holding member by rivets. In addition, as described above, the holder 9 may not be provided.

[0044] In the above embodiment, a pulling wire (excess length wire, soft wire, metal strand) 10 is respectively arranged between the two S springs 7 on the right and left sides. However, a pulling wire (excess length wire, soft wire, metal strand) 10 may also be arranged between the holding member 8 connecting the two adjacent S springs 7 in the center and the cross beam (rear beam 3 or front pad 5).

[0045] A resin coating may be formed on the surface of the above-mentioned pulling wire (excess length wire, flexible wire, metal strand) 10. The resin coating prevents the generation of noise caused by contact with peripheral parts and the inner peripheral edge of the mounting hole.

[0046] In addition, in the above-mentioned embodiment, a pulling wire (excess length wire, flexible wire, metal strand) 10 is arranged between the two holding members 8 (holding parts 9) on the right side (or left side). Alternatively, a pulling wire (excess length wire, flexible wire, metal strand) 10 may also be arranged between the two holding members 8 (holding parts 9).

[0047] In addition, in the present embodiment, the S spring 7 is stretched between the rear beam 3 and the front beam 4 (i.e., between the two cross beams) along the front-rear direction, but it may also be stretched between a pair of side arms 2, i.e., in the left-right direction. In this case, one end of the pulling wire (excess length wire, soft wire, metal strand) 10 is attached to the retaining member 8, and the other end thereof is attached to one of the two side arms 2.

[0048] In addition, the seat frame of the above embodiment is a seat frame of a slidable seat for one person. However, the seat frame of the present invention can also be applied to a seat frame of a seat for multiple people such as a rear seat that cannot slide.

[0049] Description of Reference Numerals

[0050] 1. Bottom frame; 2. Side arms; 3. Rear beam (cross beam); 4. Front beam (cross beam); 5. Front pad (cross beam); 7. S spring (snaking spring); 8. Retaining member; 10. Traction wire (excess length wire, soft wire, metal strand); 11A, buffer rubber; 12. Battery pack (device unit).

Claims

1. A vehicle seat frame, comprising: A pair of side arms of the bottom frame supporting the buttocks and thighs of the passenger from below; a pair of cross beams connecting the front and rear portions of the side arms, respectively; at least two S-springs, which are stretched between the cross beams or between the side arms; a retaining member installed between the S springs; and A traction line is suspended between the holding member and one of the cross beams, or between the holding member and one of the side arms.

2. The vehicle seat frame according to claim 1, wherein: The pulling wire is an excess length wire having a length longer than a distance between a mounting position where one end of the pulling wire is mounted on the holding member and a mounting position where the other end of the pulling wire is mounted on the one of the beams or the one of the side arms.

3. The vehicle seat frame according to claim 2, wherein: The excess length line is a soft line.

4. The vehicle seat frame according to claim 3, wherein: The flexible wire is a metal strand.

5. The vehicle seat frame according to any one of claims 1 to 4, wherein: The vehicle seat frame further comprises: a device unit mounted below the bottom frame and having a height higher than that of a floor of the passenger's footwell; and A cushioning rubber is mounted to a lower surface of the holding member.

6. The vehicle seat frame according to any one of claims 1 to 5, wherein: One end of the pulling wire is mounted on the mounting position of the holding member, and the pulling wire is mounted in a swingable manner. The other end of the pulling wire is mounted on a mounting position of the one of the cross beams or the one of the side arms, and the pulling wire is mounted in a swingable manner.

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