Seat

Abstract

The present disclosure provides a seat capable of lifting and displacing one end side of a seat cushion in the front-rear direction. A seat according to the present disclosure is provided with a side frame, and a posture conversion mechanism having a first link and a second link. The lower end side of the first link is rotatably connected to the base member, the lower end side of the second link is rotatably connected to the upper end side of the first link, and the upper end side of the second link is rotatably connected to the side frame. The connection center (movement center) connecting the first link and the second link is located rearward of the connection center (second center) of the second link and the side frame. Further, when in the normal posture, the center of movement is located at the same height as or at a position higher than a center line, which is a virtual line extending in the front-rear direction through a first center, which is the center of connection between the base member and the side frame, and a second center, which is the center of connection between the base member and the side frame.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a seat capable of causing one end side of a seat cushion in a front-rear direction to be displaced upward and downward. BACKGROUND

[0002] For example, a seat for a vehicle described in Chinese Patent No. 114889503A (Patent Document 1) is provided with a posture conversion mechanism capable of causing a front end side of a seat cushion to be displaced upward and downward. SUMMARY

[0003] A side frame (also referred to as a lower arm) that is part of a seat cushion frame is a strength member that extends along a seat front-rear direction. For example, when a large external force that stretches the entire side frame in the rearward direction is applied to the side frame, in the invention described in Patent Document 1, an unintended upward displacement of the front end side of the seat cushion can occur. In view of this problem point, the present disclosure discloses one example of a seat.

[0004] A seat capable of causing one end side of a seat cushion in a front-rear direction to be displaced upward and downward preferably has at least one of, for example, the following configuration requirements.

[0005] The configuration requirement includes a side frame that extends along a seat front-rear direction and is part of a seat cushion frame, and the side frame has a joint portion that directly or indirectly joins one end side of the side frame in the extending direction to a base member in a rotatable manner, and a posture conversion mechanism that has a first link and a second link for joining the other end side of the side frame in the extending direction to the base member, and the posture conversion mechanism causes one end side of the seat cushion in the front-rear direction to be displaced upward and downward by changing an angle formed between the first link and the second link.

[0006] Further, it is preferable that when a joint center that joins the first link and the second link is taken as a movement center, the movement center is located at a position that is rearward of the second center, and further, it is preferable that at least when a normal posture in which one end side of the seat cushion in the front-rear direction has been lowered is taken, the movement center is located at the same height as the center line, or at a position that is higher than the center line.

[0007] A lower end side of the first link is joined to the base member in a rotatable manner, a lower end side of the second link is joined to an upper end side of the first link in a rotatable manner, and an upper end side of the second link is joined to the side frame in a rotatable manner.

[0008] The first center is a joint center of the base member and the side frame in the joint portion, the second center is a joint center of the second link and the side frame, and the center line is an imaginary line that passes through the first center and the second center and extends along the front-rear direction.

[0009] Thus, when the external force acts on the side frame, a force that reduces the angle formed between the first link and the second link acts on the second center.

[0010] That is, in the seat, when the external force acts on the side frame, a force that lowers one end side of the seat cushion is generated on the seat cushion. Thus, it is possible to suppress the occurrence of unintended upward displacement of one end side of the seat cushion.

[0011] The seat can have, for example, the following configuration.

[0012] Preferably, the connecting portion is connected to the base member via a lifting link, a lower end side of the lifting link is rotatably connected to the base member, and an upper end side of the lifting link is rotatably connected to the side frame at the first center. Further, preferably, the seat cushion as a whole is displaced upward and downward by swinging the lifting link with respect to the base member while the angle formed between the first link and the second link is constant.

[0013] Preferably, the first center is located on a rear end side of the side frame, and the second center is located on a front end side of the side frame. Further, preferably, the link length of the first link is longer than the link length of the second link. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a view showing a seat cushion frame of the first embodiment.

[0015] Figure 2 is a view showing a seat cushion frame of the first embodiment.

[0016] Figure 3 is a view showing a seat cushion frame of the first embodiment.

[0017] Figure 4 is a view showing a driving side conversion mechanism of the first embodiment.

[0018] Figure 5 is a view showing a driving side conversion mechanism of the first embodiment.

[0019] Figure 6 is a view showing a driving side conversion mechanism of the first embodiment.

[0020] Figure 7 is a view showing a driving side conversion mechanism of the first embodiment.

[0021] Figure 8 is a view showing a driven side conversion mechanism of the first embodiment.

[0022] Figure 9is a view showing a drive side conversion mechanism of the first embodiment.

[0023] Figure 10 is a view showing a positional relationship of a cushion and a joint site. DETAILED DESCRIPTION

[0024] An exemplary embodiment of the present disclosure will be described below with reference to the accompanying drawings.

[0025] The following embodiment of the invention shows one example of an embodiment within the technical scope of the present disclosure. That is, the technical solutions recited in the claims and the like are not limited to the specific structures or configurations and the like shown in the following embodiment.

[0026] The present embodiment is an example of a seat for a vehicle or the like (hereinafter referred to as a vehicle seat) installed in a vehicle or the like. The arrows and the like shown in each drawing indicate directions, and the hatching and the like are symbols that are labeled for the purpose of facilitating understanding of the mutual relationships of the drawings and the shapes of the components or sites and the like.

[0027] The vehicle seat is not limited to the directions shown in the drawings. The directions shown in the drawings are in a state in which the vehicle seat of the present embodiment is assembled in a vehicle. The drawings in which hatching is labeled do not necessarily represent cross-sectional views.

[0028] For the components or sites labeled with at least a symbol, at least one is provided, except in the case of a prior declaration of "only one" or the like. The seat shown in the present disclosure includes at least one of the constituent elements, such as the components or sites labeled with a symbol, and the structural sites illustrated.

[0029] (First Embodiment)

[0030] <1. Overview of Vehicle Seat>

[0031] As shown in Figure 1 , the vehicle seat 1 is provided with a seat cushion 3, a seat backrest (not shown), a lifting mechanism 5, and a posture conversion mechanism 7. The seat cushion 3 is a site for supporting the buttocks of a seated person.

[0032] The seat backrest is a site for supporting the back of a seated person. The seat backrest is connected to the rear end side of the seat cushion 3. The seat backrest is connected to the seat cushion 3 in a manner that allows swinging in the front-rear direction of the seat.

[0033] The lifting mechanism 5 is a mechanism that causes the seat cushion 3 to displace in a lifting manner, in a manner that causes the seat cushion 3 as a whole to move in parallel. The posture conversion mechanism 7 is a mechanism for converting the posture of the seat cushion 3 between a comfortable posture and a regular posture.

[0034] As shown in Figure 2As shown, a comfortable posture refers to a posture in which the front end of the seat cushion 3 is higher than the rear end of the seat cushion 3. For example... Figure 1 As shown, the conventional posture refers to a posture in which the height difference between the front end and the rear end of the seat cushion 3 is smaller compared to the comfortable posture.

[0035] In other words, the conventional posture is mainly the posture used by the driver of the vehicle when driving it. The lifting mechanism 5 in this embodiment causes the seat cushion 3, which is in the conventional posture, to move up and down.

[0036] The seat cushion 3 is connected to the sliding device 9 via the lifting mechanism 5 and the posture changing mechanism 7. When the lifting mechanism 5 is activated, the posture changing mechanism 7 functions as the lifting link of the lifting mechanism 5.

[0037] The lifting mechanism 5 has lifting linkages 5A and 5B (see reference). Figure 3 The lifting links 5A and 5B are used to lift and lower the rear end of the seat cushion 3. Furthermore, when the lifting mechanism 5 is activated, the posture changing mechanism 7 functions as a lifting link to lift and lower the front end of the seat cushion 3.

[0038] The sliding device 9 supports the seat cushion 3 so that it can move in the fore-and-aft direction. In this embodiment, the seat cushion 3 is supported by two sliding devices 9. Each sliding device 9 has a movable guide rail 9A and a fixed guide rail 9B.

[0039] Each fixed guide rail 9B is a guide rail component fixed to the vehicle. The movable guide rail 9A is an example of a base component, which is slidably connected to the fixed guide rail 9B. Therefore, the seat cushion 3 can slide relative to the vehicle.

[0040] <2. Composition of the seat frame and posture transformation mechanism, etc.>

[0041] <2.1 Composition of the Seat Cushion Frame>

[0042] The seat cushion frame 10 is a structural component that forms the skeleton of the seat cushion 3. For example... Figure 1 As shown, the seat frame 10 has a first side frame 11, a second side frame 12, a front rod 13, and a rear rod 14.

[0043] The first side frame 11 is a lower arm disposed on one end in the width direction of the seat and extending along the fore-and-aft direction of the seat. The second side frame 12 is a lower arm disposed on the other end in the width direction of the seat and extending along the fore-and-aft direction of the seat.

[0044] The front side bar 13 extends in the seat width direction and links the front end sides of the first side frame 11 and the second side frame 12 to each other, and the front side bar 13 is rotatably linked to each side frame 11, 12.

[0045] The rear side bar 14 extends in the seat width direction and links the rear end sides of the first side frame 11 and the second side frame 12 to each other, and the rear side bar 14 is rotatably linked to each side frame 11, 12. The upper end sides of the lift links 5A, 5B are integrated with the rear side bar 14 by a joining method such as welding.

[0046] As shown in Figure 3 , the lower end sides of the lift links 5A, 5B are rotatably linked to the corresponding movable rails 9A via the brackets 5C, 5D, respectively. In other words, the rear end side of the cushion frame 10 is indirectly rotatably linked to the movable rails 9A via the lift links 5A, 5B.

[0047] The lift link 5A and the bracket 5C function as a linking portion that indirectly rotatably links the rear end side of the first side frame 11 to the movable rails 9A. The lift link 5B and the bracket 5D function as a linking portion that indirectly rotatably links the rear end side of the second side frame 12 to the movable rails 9A.

[0048] An actuator 5E (refer to Figure 3 ) is provided on the first side frame 11 or the second side frame 12 (the first side frame 11 in the present embodiment). The actuator 5E generates a driving force that rotates the rear side bar 14.

[0049] Thus, when the actuator 5E operates to rotate the rear side bar 14, the lift links 5A, 5B are displaced in rotation relative to the cushion frame 10, and the cushion frame 10 is displaced in elevation in conjunction with this displacement in rotation.

[0050] <2.2 Configuration of the posture conversion mechanism>

[0051] As shown in Figure 3 , the posture conversion mechanism 7 has a driving side conversion mechanism 71 and a driven side conversion mechanism 72. The driving side conversion mechanism 71 generates a driving force that changes the posture of the seat cushion 3. The driven side conversion mechanism 72 receives the driving force from the driving side conversion mechanism 71 and cooperates with the driving side conversion mechanism 71 to change the posture of the seat cushion 3.

[0052] <2.3 Configuration of the driving side conversion mechanism>

[0053] As shown in Figure 4As shown, the drive-side conversion mechanism 71 includes a first drive-side connecting rod 71A, a second drive-side connecting rod 71B, a sector gear 71C, and an actuator 71D. Figure 5 As shown, the lower end of the first drive-side connecting rod 71A is rotatably connected to the movable guide rail 9A via the bracket 71E.

[0054] The lower end of the second drive-side link 71B is rotatably connected to the upper end of the first drive-side link 71A. The upper end of the second drive-side link 71B is rotatably connected to the first side frame 11.

[0055] Specifically, the upper end of the second drive-side link 71B is integrally fixed to the front rod 13 by welding or other means, and the front rod 13 is rotatably connected to the first side frame 11. Therefore, the upper end of the second drive-side link 71B is configured to be rotatably connected to the first side frame 11.

[0056] like Figure 6 As shown, the connection portion J1 between the first drive-side link 71A and the second drive-side link 71B is located between the sector gear 71C and the first side frame 11. In this embodiment, the connection portion J1 is located at a position spaced apart from the sector gear 71C toward the first side frame 11.

[0057] Furthermore, the second drive-side link 71B is located between the first drive-side link 71A and the first side frame 11. The second drive-side link 71B is located on the side closer to the first side frame 11 relative to the first drive-side link 71A.

[0058] In this embodiment, such as Figure 5 As shown, the link length Lk1 of the first drive-side link 71A is longer than the link length Lk2 of the second drive-side link 71B. Furthermore, the connection center between the first drive-side link 71A and the movable guide rail 9A is located further forward than the center O2 of the front rod 13.

[0059] like Figure 6 As shown, the sector gear 71C is integrally fixed to the front rod 13 by welding or other means. Therefore, when the sector gear 71C rotates, the front rod 13 rotates accordingly, thereby causing the second drive-side connecting rod 71B to rotate around the axis L1.

[0060] Axis L1 is the central axis of the front rod 13. The rotation center of the sector gear 71C is located on axis L1. The rotation center of the sector gear 71C and the rotation center of the connection between the second drive-side connecting rod 71B and the first side frame 11 are both located on axis L1.

[0061] In the present embodiment, the rotation center of the sector gear 71C and the link rotation center of the 2nd drive-side link 71B and the 1st side frame 11 are separated from each other in the direction of the axis L1 by a distance. Therefore, the front-side link material 13 functions as a transmission portion that transmits the rotation of the sector gear 71C to the 2nd drive-side link 71B.

[0062] The actuator 71D generates a drive force that rotationally drives the sector gear 71C. This actuator 71D has an electric motor (not shown) and a speed reducer (not shown).

[0063] The electric motor outputs a rotational force. The speed reducer is a gear device that has at least a worm and a worm wheel, and outputs after reducing the output of the electric motor. The actuator 71D is fixed to the 1st drive-side link 71A.

[0064] The actuator 71D, since it has the electric motor and the speed reducer, is virtually unable to rotate the electric motor by applying a rotational force to the output shaft of the speed reducer from the outside. This phenomenon will be referred to as "self-locking function" hereinafter.

[0065] Furthermore, as shown in Figure 7 , the link center (hereinafter referred to as the movement center Om) that links the 1st drive-side link 71A and the 2nd drive-side link 71B is located at a position that is further back than the 2nd center O2. In addition, in the normal posture, the movement center Om is located at a position that is higher than the center line Lc.

[0066] The center line Lc refers to a virtual line that passes through the 1st center O1 and the 2nd center O2 and extends in the seat front-rear direction. The 1st center O1 refers to the link center of the lift link 5A and the 1st side frame 11.

[0067] The 2nd center O2 refers to the link center of the 2nd drive-side link 71B and the 1st side frame 11. The 1st center O1 of the present embodiment is located on the center axis of the rear-side link material 14. The 2nd center O2 of the present embodiment is located on the center axis of the front-side link material 13.

[0068] <2.4 Configuration of the driven-side conversion mechanism>

[0069] As shown in Figure 8 , the driven-side conversion mechanism 72 has a 1st driven-side link 72A and a 2nd driven-side link 72B. The 1st driven-side link 72A is a link that corresponds to the 1st drive-side link 71A. The 2nd driven-side link 72B is a link that corresponds to the 2nd drive-side link 71B.

[0070] The lower end side of the 1st driven side link 72A is rotatably connected to the movable rail 9A. The lower end side of the 2nd driven side link 72B is rotatably connected to the upper end side of the 1st driven side link 72A. The upper end side of the 2nd driven side link 72B is rotatably connected to the 2nd side frame 12 via the front side link member 13.

[0071] No driving mechanism such as a sector gear and an actuator is provided on the driven side conversion mechanism 72. The driving force of the actuator 71D is transmitted to the driven side conversion mechanism 72, i.e., to the 2nd driven side link 72B and the 1st driven side link 72A, via the front side link member 13.

[0072] <3. Action of the posture conversion mechanism and features of the vehicle seat of the present embodiment>

[0073] <3.1 Action of the posture conversion mechanism>

[0074] In a state where the actuator 71D is stopped, the angle θ1 (refer to Figure 5 ) formed between the 1st driving side link 71A and the 2nd driving side link 71B, and the angle θ2 (refer to Figure 8 ) formed between the 1st driven side link 72A and the 2nd driven side link 72B, are maintained in the current state by the self-locking function.

[0075] Therefore, in a state where the actuator 71D is stopped, when the actuator 5E of the lifting mechanism 5 is actuated, the lifting links 5A, 5B are swing-displaced with respect to the movable rail 9A in a state where the angles θ1, θ2 are maintained, so that the seat cushion 3 is lifted and lowered as a whole in a parallel movement.

[0076] Further, in a state where the actuator 5E of the lifting mechanism 5 is stopped, when the actuator 71D of the posture conversion mechanism 7 is actuated, the angles θ1, θ2 are changed in increase and decrease, so that the front end side of the seat cushion 3 is lifted and lowered with respect to the rear end side of the seat cushion 3.

[0077] <3.2 Features of the vehicle seat>

[0078] As shown in Figure 9 , when a large external force Fo that stretches the 1st side frame as a whole rearward is applied to the 1st side frame 11, a force F1 that decreases the angle θ1 formed between the 1st driving side link 71A and the 2nd driving side link 71B is applied to the 2nd center O2, i.e., to the front side link member 13.

[0079] When the external force Fo acts on the second side frame 12, the same as the first side frame 11 side, a force F1 that decreases the angle θ2 formed between the first driven side link 72A and the second driven side link 72B acts on the front side link member 13.

[0080] Therefore, in the vehicle seat 1 of the present embodiment, when the above-described external force Fo acts on the first side frame 11 and the second side frame 12, a force that lowers the front end side of the seat cushion 3 is generated on the seat cushion 3. Thus, it is possible to suppress the case where the front end side of the seat cushion 3 is undesirably displaced upward.

[0081] As shown in Figure 6 , the joint portion J1 of the first driven side link 71A and the second driven side link 71B is located between the sector gear 71C and the first side frame 11. Thus, in the vehicle seat 1, as shown in Figure 10 , the joint portion J1 is offset outward in the seat width direction with respect to the cushion 3A of the seat cushion 3.

[0082] Therefore, it is possible to suppress the case where the posture conversion mechanism 7 interferes with the lower surface of the cushion 3A (see A of Figure 10 ). Further, since it is not necessary to provide a cover or the like that covers the upper side of the posture conversion mechanism 7, it is possible to suppress an increase in the manufacturing cost of the vehicle seat 1.

[0083] In the present embodiment, since the outer diameter dimension of the sector gear 71C is large, if the sector gear 71C is located at a position offset outward in the seat width direction from the position shown in Figure 6 , the sector gear 71C interferes with the slide device 9.

[0084] (Other Embodiments)

[0085] In the above-described embodiment, the movement center Om is located at a position higher than the center line Lc when in the normal posture. However, the present disclosure is not limited thereto. For example, the movement center Om can be at the same height as the center line Lc when in the normal posture.

[0086] In the above-described embodiment, the posture conversion mechanism 7 is configured to be disposed at the front end side of the seat cushion 3. However, the present disclosure is not limited thereto. For example, the posture conversion mechanism 7 can be configured to be disposed at the rear end side of the seat cushion 3, or the posture conversion mechanism 7 can be disposed at the front end side and the rear end side of the seat cushion 3.

[0087] In the above-described embodiment, the link length Lk1 of the first drive-side link 71A is longer than the link length Lk2 of the second drive-side link 71B. However, the present disclosure is not limited to this. For example, the link length Lk1 can be shorter than the link length Lk2, or the link length Lk1 can be the same as the link length Lk2.

[0088] In the above-described embodiment, the configuration is such that the lifting mechanism 5 is provided. However, the present disclosure is not limited to this. For example, a configuration in which the lifting mechanism 5 is omitted can be adopted. In this configuration, the first side frame 11 and the second side frame 12 are directly connected to the movable rail 9A in a rotatable manner without passing through the lifting links 5A and 5B.

[0089] In the above-described embodiment, the vehicle seat 1 is fixed to the floor of the vehicle via the slide device 9. However, the present disclosure is not limited to this. For example, the vehicle seat 1 can be directly fixed to the floor of the vehicle without passing through the slide device 9.

[0090] In the above-described embodiment, the vehicle seat of the present disclosure is applied to a vehicle. However, the application of the invention disclosed in the present specification is not limited to this. That is, the present disclosure can also be applied to a seat used in a vehicle such as a railway vehicle, a ship, and an aircraft, and a fixed-type seat used in a theater or a home, and the like.

[0091] Further, the present disclosure is not limited to the above-described embodiments as long as the gist of the invention described in the above-described embodiments is satisfied. Therefore, it can be a structure in which at least two of the above-described embodiments are combined, or a structure in which any one of the configuration elements illustrated in the above-described embodiments is omitted, or a structure in which any one of the configuration elements described using reference numerals in the above-described embodiments is omitted.

Claims

1. A seat capable of lifting displacement of one end side of a seat cushion in a front-rear direction, characterized by comprising: a side frame extending in a seat front-rear direction and constituting a part of a cushion frame, and having a linking portion linking one end side of the side frame in an extending direction directly or indirectly to a base member in a rotatable manner; and a posture conversion mechanism having a first link and a second link for linking the other end side of the side frame in the extending direction to the base member, and lifting displacing the one end side of the seat cushion in the front-rear direction by changing an angle formed between the first link and the second link, and wherein a lower end side of the first link is linked to the base member in a rotatable manner, a lower end side of the second link is linked to an upper end side of the first link in a rotatable manner, an upper end side of the second link is linked to the side frame in a rotatable manner, when a linking center of the base member and the side frame in the linking portion is a first center, a linking center of the second link and the side frame is a second center, and a virtual line extending in the front-rear direction through the first center and the second center is a center line, a linking center linking the first link and the second link is a moving center, the moving center is located at a position more rearward than the second center, and at least when in a normal posture in which the one end side of the seat cushion in the front-rear direction has been lowered, the moving center is located at the same height as the center line or at a position higher than the center line.

2. The seat according to claim 1, wherein the linking portion is linked to the base member via a lifting link, a lower end side of the lifting link is linked to the base member in a rotatable manner, and an upper end side of the lifting link is linked to the side frame in a rotatable manner at the first center, and in a state in which an angle formed between the first link and the second link is constant, the seat cushion is lifted displaced as a whole by swing displacement of the lifting link with respect to the base member.

3. The seat according to claim 2, wherein the first center is located at a rear end side of the side frame, and the second center is located at a front end side of the side frame.

4. The seat according to any one of claims 1 to 3, wherein a link length of the first link is longer than a link length of the second link. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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