Vehicle seats

Abstract

To suppress operability from deteriorating accompanying displacement of a lock mechanism to a lock position, when a seat belt is detached.SOLUTION: A suspension 14 is configured to enable a height of a vehicular seat 10 to change by supplying and exhausting air to and from an air chamber of an air spring arranged at a lower side of a vehicle of a vehicular seat 10, in accordance with operation of a height switch for instructing change of a height of the vehicular seat 10. A lock mechanism can be displaced to a lock position where change of the height of the vehicular seat 10 is locked or to a lock-releasing position where the lock is released. A control part makes a memory memorize a position of the lock mechanism, when a determining part determines that an occupant is seated on the vehicular seat 10; makes a suspension lock ACT displace the lock mechanism to the lock position when a seat belt 130 is detached; and makes the suspension lock ACT displace the lock mechanism to the lock-releasing position, if the position of the lock mechanism memorized in the memory is the lock-releasing position, when the seat belt 130 is attached thereto.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to vehicle seats. [Background technology]

[0002] Patent document 1 describes a vehicle seat that includes an air suspension mechanism that can change the height of the seat by supplying or exhausting air to an air chamber located below the seat in response to the operation of a specified switch, and a locking mechanism that can be displaced to a locked position that locks the seat against changes in height or an unlocked position that releases the lock. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-046172 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology of Patent Document 1 displaces the locking mechanism to a locked position by an actuator when the seat belt is unfastened, preventing the seat from rising when the seated occupant stands up to exit the vehicle, thereby improving the ease of exiting and boarding the vehicle. However, with the technology of Patent Document 1, the locking mechanism is in the locked position when the occupant is seated in the seat. Therefore, if the occupant wants to change the seat height while seated, the occupant must operate the locking mechanism to displace it to the unlocked position, which poses a problem of reduced operability.

[0005] The present disclosure has been made in consideration of the above facts, and aims to provide a vehicle seat that can suppress deterioration in operability that occurs when the locking mechanism is displaced to the locking position by an actuator when the seat belt is removed. [Means for solving the problem]

[0006] The vehicle seat of the first aspect includes an air suspension mechanism capable of changing the height of the seat by supplying and exhausting air to an air chamber located below the seat; a locking mechanism that can be displaced to a locked position that locks the change in the height of the seat or to an unlocked position that releases the lock; an actuator that displaces the locking mechanism; and a control unit that stores the position of the locking mechanism in a memory unit when a determination unit determines that an occupant is seated in the seat, and displaces the locking mechanism to the locked position by the actuator when the seat belt is unfastened, and displaces the locking mechanism to the unlocked position by the actuator when the seat belt is fastened and the position stored in the memory unit is the unlocked position.

[0007] In a first aspect, when the seat belt is unfastened, the actuator displaces the locking mechanism to the locked position. This prevents the seat from rising when the seated occupant stands up. Furthermore, in a vehicle seat including a locking mechanism, the occupant can freely select either the locked position or the unlocked position as the position of the locking mechanism when the occupant is seated. In the first aspect, when it is determined that the occupant is seated in the seat, the position of the locking mechanism is stored in a memory unit. When the seat belt is fastened, if the position stored in the memory unit is the unlocked position, the actuator displaces the locking mechanism to the unlocked position. This allows the locking mechanism to be returned to the position selected by the occupant while seated in the seat. Even if the occupant wishes to change the seat height while seated, the occupant does not need to perform an operation to displace the locking mechanism to the unlocked position when seated, thereby preventing a deterioration in operability.

[0008] In the second aspect, in the first aspect, the determination unit determines that an occupant is seated in the seat when an occupant is detected to be seated in the seat by an occupancy sensor and a seat belt is detected to be fastened by a buckle sensor.

[0009] In the second aspect, it is determined whether an occupant is seated in the seat based on the detection results of the seating sensor and the buckle sensor, so that it is possible to accurately determine whether an occupant is seated in the seat.

[0010] A third aspect is the first or second aspect, further including a lock sensor incorporated in the actuator that detects the position of the output shaft of the actuator, thereby indirectly detecting whether the locking mechanism is in a locked position or an unlocked position, and the control unit recognizes the position of the locking mechanism based on a signal from the lock sensor.

[0011] In the third aspect, the lock sensor indirectly detects the position of the lock mechanism by detecting the position of the output shaft of the actuator, so that the lock sensor, and therefore the lock mechanism, can be made smaller. [Effects of the Invention]

[0012] The present disclosure has an advantage in that it is possible to suppress deterioration in operability that occurs when the locking mechanism is displaced to the locking position by the actuator when the seat belt is unfastened. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a perspective view showing the appearance of a vehicle seat; [Figure 2] FIG. [Figure 3] FIG. 10 is a perspective view showing a link mechanism equipped with a locking mechanism. [Figure 4] FIG. 2 is an exploded perspective view showing a link mechanism equipped with a locking mechanism. [Figure 5]FIG. 10 is a side view showing the link mechanism with the lock mechanism body attached thereto. [Figure 6] FIG. 2 is a perspective view showing a locking mechanism main body. [Figure 7] FIG. 2 is an exploded perspective view showing the locking mechanism body. [Figure 8] FIG. 2 is an exploded perspective view showing a cam plate and a cam. [Figure 9] FIG. 10 is a plan view showing the unlocked state of the locking mechanism. [Figure 10] FIG. 10 is a plan view showing the locking state of the locking mechanism. [Figure 11] 2 is a block diagram showing the configuration of a seat ECU and its surroundings. FIG. [Figure 12] FIG. 2 is a functional block diagram of a seat ECU. [Figure 13] FIG. 10 is an image diagram showing the operation when air is supplied to or exhausted from the air spring while the locking mechanism is in the unlocked state. [Figure 14] This is an image showing that in a truck, the distance between the feet of a seated occupant and the steering wheel is short. [Figure 15] FIG. 1 is a diagram showing an example of a work pattern of a vehicle occupant at a construction site or the like. [Figure 16] 10 is a flowchart showing a process when the lock switch is on. [Figure 17] 10 is a flowchart showing a process at the time of height manipulation. [Figure 18] 10 is a flowchart showing a process when removing a belt. [Figure 19] 10 is a flowchart showing a process when a belt is fastened. [Figure 20] 10 is a flowchart showing an occupant change monitoring process. DETAILED DESCRIPTION OF THE INVENTION

[0014] An example of an embodiment of the present disclosure will be described in detail below with reference to the drawings. Note that, although the following embodiment will be described using numerical values ​​that do not impede the present disclosure, the present disclosure is not limited to the numerical values ​​described in the following embodiment. In the following drawings, the arrow FR indicates the front side of the seat, the arrow UP indicates the upper side of the seat, and the arrow W indicates the seat width direction. The seat width direction coincides with the left and right directions of the seat. Hereinafter, when simply referring to front-rear, up-down, and left-right directions, these refer to front-rear in the front-rear direction of the seat, up-down in the up-down direction of the seat, and left-right in the left-right direction of the seat, unless otherwise specified.

[0015] A vehicle seat 10 shown in Fig. 1 is installed in a vehicle (not shown) and seats an occupant in the vehicle. A seat body 12 of the vehicle seat 10 includes a seat cushion 12A that supports the thighs and buttocks of the seated occupant, a seat back 12B that supports the back of the occupant, and a headrest 12C that supports the head of the occupant. The seat cushion 12A has a cushion pad attached to the upper side of a seat frame (not shown) serving as a framework member. The seat back 12B has a back pad attached to the front side of a back frame (not shown) serving as a framework member, and a headrest 12C attached to the upper part of the seat back 12B.

[0016] In the vehicle seat 10, the lower end of the back frame is rotatably connected to the rear end of the seat frame, and the seat back 12B is tiltable relative to the seat cushion 12A (reclining mechanism). The vehicle seat 10 is also provided with a slide mechanism that allows movement in the front-rear direction relative to the vehicle body, and an elevation mechanism (lift mechanism) that allows the seat back 12B and headrest 12C to move up and down together with the seat cushion 12A.

[0017] The vehicle seat 10 is a so-called suspension seat, and a suspension 14 is provided below a seat body 12. As shown in Fig. 2, the suspension 14 includes a lower frame 16, an upper frame 18 disposed above the lower frame 16, and a suspension link mechanism 20 that vertically connects the lower frame 16 and the upper frame 18. The suspension 14 also includes an air spring 22 (see Fig. 4) that supports the seat body 12 from below and serves as a lifting and cushioning member that, when actuated, lifts the seat body 12 upward or lowers the seat body 12 downward, thereby cushioning impacts to the seat body 12, and a damper 24. The suspension 14 including the air spring 22 is an example of a suspension mechanism in the present disclosure.

[0018] 2, the lower frame 16 has a lower portion fixed to the floor of the vehicle compartment via seat rails (both not shown). The lower frame 16 includes a pair of left and right rail members 16A extending in the front-rear direction at both left and right ends, and a pair of front and rear cross members 16B extending in the front and rear directions at the front and rear ends of the rail members 16A. Therefore, the lower frame 16 is formed in a generally frame shape in a plan view.

[0019] An upper frame 18 is disposed above the lower frame 16. The upper frame 18 includes a pair of left and right rail members 18A extending in the front-rear direction at both left and right ends, and a pair of front and rear cross members 18B extending in the front and rear directions at the front and rear ends of the rail members 18A. Therefore, the upper frame 18 is formed in a generally frame shape in a plan view. The upper frame 18 is disposed below the seat body 12 (see FIG. 1). Thus, the seat body 12 is supported from below by the suspension 14.

[0020] (Configuration of suspension link mechanism) As shown in Figures 2, 3, and 4, the suspension link mechanism 20 includes a pair of left and right X links 28 serving as links located at both left and right ends of the lower frame 16 and the upper frame 18. Each pair of left and right X links 28 includes an inner link arm 30 serving as a first link member located on the inner side in the left-right direction, and an outer link arm 32 serving as a second link member located on the outer side in the left-right direction relative to the inner link arm 30. The inner link arm 30 is inclined upward as it extends forward. The outer link arm 32 is inclined downward as it extends forward. The longitudinal center of the inner link arm 30 and the longitudinal center of the outer link arm 32 are connected via a link shaft 34 serving as a rotation axis whose rotation axis is in the left-right direction. This allows the inner link arm 30 and the outer link arm 32 to rotate relative to each other around the link shaft 34.

[0021] The suspension link mechanism 20 includes a front upper connecting shaft 36 that connects the front ends of the left and right inner link arms 30 in the left-right direction. The suspension link mechanism 20 also includes a front lower connecting shaft 38 that connects the front ends of the left and right outer link arms 32 in the left-right direction. The suspension link mechanism 20 also includes a rear lower connecting shaft 40 that connects the rear ends of the left and right inner link arms 30 in the left-right direction. The suspension link mechanism 20 also includes a plate-shaped connecting plate 41 that connects the upper edges of the rear portions of the left and right inner link arms 30 in the left-right direction. The suspension link mechanism 20 also includes a rear upper connecting shaft 42 that connects the rear ends of the left and right outer link arms 32 in the left-right direction. The front upper connecting shaft 36 and the rear upper connecting shaft 42 are supported by the rail members 18A of the upper frame 18. The front lower connecting shaft 38 and the rear lower connecting shaft 40 are supported by the rail members 16A of the lower frame 16.

[0022] The upper frame 18 moves up and down as the left and right X links 28 synchronously expand and contract. Specifically, when the upper frame 18 is displaced (raised) upward, the inclination directions of the inner link arm 30 and the outer link arm 32 are displaced (raised) so as to approach the vertical direction. As a result, the X links 28 expand upward, and the upper frame 18 is displaced (raised) upward.

[0023] When the upper frame 18 is displaced (lowered) downward, the inner link arm 30 and the outer link arm 32 are displaced (folded) so that the inclination direction approaches the front-to-rear direction. As a result, the X link 28 is contracted downward, and the upper frame 18 is displaced (lowered) downward.

[0024] (air springs, dampers) As shown in FIG. 4 , the air spring 22 is disposed between the upper frame 18 and the lower frame 16 and between the left and right X-links 28. The air spring 22 is configured so that compressed air is supplied to an internal air chamber from, for example, an air compressor (air supply source) constituting an air brake system of the vehicle. The air spring 22 biases the upper frame 18 upward and generates a reaction force against a load acting from the seat main body 12 (upper side). Vibration of the air spring 22 is absorbed by a hydraulic cylinder-type damper 24. The suspension link mechanism 20 expands and contracts in the vertical direction as the air spring 22 expands and contracts. This allows the upper frame 18 and the seat main body 12 to be displaced in the vertical direction. With this configuration, the load (body weight) of an occupant seated in the seat main body 12 mounted on the upper frame 18 is transmitted (loaded) to the air spring 22. When the X-link 28 is not restrained by the locking mechanism 50 described below, the load applied to the air spring 22 is buffered together with the vibration absorbing action of the damper 24. When air is supplied to the air chamber inside the air spring 22, the air spring 22 expands upward, causing the upper frame 18 to rise and the height position of the seat main body 12 to be adjusted upward. When air is exhausted from the air chamber of the air spring 22, the air spring 22 contracts downward, causing the upper frame 18 to descend and the height position of the seat main body 12 to be adjusted downward.

[0025] (locking mechanism) 3, 4, and 5, the vehicle seat 10 of this embodiment is equipped with a locking mechanism 50 that locks the vertical displacement of the seat body 12 caused by the suspension 14. The locking mechanism 50 is equipped with a locking mechanism main body 53 that is disposed along one of the pair of X links 28 and supported by the one X link 28, and a suspension lock ACT (actuator) 64 that serves as a motor that operates the locking mechanism main body 53. In this embodiment, the locking mechanism main body 53 is supported by the right X link 28.

[0026] As shown in Figures 5, 6, and 7, the locking mechanism body 53 is disposed forward with respect to the rotation axis of the X link 28. The locking mechanism body 53 includes a gear 65 as a first displacement member supported by the outer link arm 32. The locking mechanism body 53 also includes a pawl 67 as a second displacement member supported by the inner link arm 30, a rotor 69 as a third displacement member, a cam plate 71 as a fourth displacement member, and a cam 73 as a fifth displacement member. The locking mechanism body 53 also includes a return bracket 75 and a cover 77 that support the pawl 67, rotor 69, cam plate 71, and cam 73. The locking mechanism body 53 also includes a return spring 79 as a biasing member that rotationally biases the cam plate 71 in one direction.

[0027] As shown in FIG. 5 , the gear 65 has a generally C-shaped curved shape when viewed from the left side. The gear 65 includes a gear body 65A whose rear and front surfaces are cylindrical and centered on the rotation axis of the X link 28. A lower end of the gear body 65A is fixed to the outer link arm 32 via a fastening member 81. An upper end of the gear body 65A is fixed to the outer link arm 32 via a fastening member 81 that penetrates the inner link arm 30. The fastening member 81 penetrates the inner link arm 30 by being inserted into an elongated hole 30A formed in the inner link arm 30. The dimensions of the elongated hole 30A are set so as not to hinder the extension and retraction of the X link 28. In other words, within the extension and retraction range of the X link 28, the fastening member 81 inserted into the elongated hole 30A does not abut against the edge of the elongated hole 30A. A plurality of engagement teeth 65B protrude from the front surface of the gear body 65A. The plurality of engagement teeth 65B are arranged at equal intervals along the front surface of the gear body 65A. The rear surface of the gear body 65A is slidably supported by a guide member 91 fixed to the inner link arm 30.

[0028] As shown in FIGS. 6 and 7 , the pawl 67 is disposed forward of the gear 65 shown in FIG. 5 . The pawl 67 is formed in a rectangular plate shape with its thickness extending in the left-right direction and its longitudinal direction extending up-down when viewed from the left or right side. A collar insertion hole 67A into which a collar 83 is inserted is formed in the upper end of the pawl 67. The upper end of the pawl 67 is rotatably supported by a return bracket 75 and a cover 77 (described later) via the collar 83. A spacer 93 is interposed between the pawl 67 and the cover 77. The return bracket 75 is not shown in FIG. 6 . A cylindrical engagement protrusion 67B protrudes toward the cover 77 from the surface of the lower end of the pawl 67 facing the cover 77. Furthermore, multiple engagement teeth 67C protrude from the rear surface of the lower end of the pawl 67. The multiple engagement teeth 67C are arranged at equal intervals along the rear surface of the lower end of the pawl 67. The front surface of the lower end of the pawl 67 serves as a cam contact surface 67D with which a cam 73, which will be described later, comes into contact.

[0029] As shown in FIG. 7 , the rotor 69 has a thickness extending in the left-right direction and is formed in an elliptical plate shape when viewed from the left or right side. A shaft insertion hole with a D-shaped edge is formed at one end of the rotor 69 when viewed from the left or right side. The shaft 85 is formed in a rod shape with its axial direction extending in the left-right direction. The end of the shaft 85 facing the return bracket 75 forms a rotor engagement portion that is inserted into the shaft insertion hole of the rotor 69. The shape of this rotor engagement portion corresponds to the interior of the shaft insertion hole, thereby connecting the rotor 69 and the shaft 85 so that they cannot rotate relative to each other. The end of the shaft 85 opposite the side that engages with the rotor 69 forms an ACT engagement portion 85B that engages with the suspension lock ACT64. The shaft 85 is inserted through the return bracket 75 and the cover 77, thereby rotatably supporting the rotor 69 on the return bracket 75 and the cover 77. A push nut 87 engages with the right end of the shaft 85 to prevent the shaft 85 from slipping out of the return bracket 75.

[0030] As shown in FIGS. 7 and 8 , the cam plate 71 is disposed between the rotor 69 and the pawl 67. The cam plate 71 includes a first base plate portion 71A formed in a rectangular plate shape with a thickness extending in the left-right direction and a longitudinal direction extending in the front-to-rear direction when viewed from the left or right side, and a second base plate portion 71B protruding upward from the front end of the first base plate portion 71A. A collar insertion hole 71C into which a collar 83 is inserted is formed at the boundary between the first base plate portion 71A and the second base plate portion 71B. The cam plate 71 is rotatably supported by the return bracket 75 and the cover 77 via the collar 83 inserted in the collar insertion hole 71C. An elongated operating hole 71D with a longitudinal direction extending in the up-down direction is formed at the rear end of the first base plate portion 71A. The engaging protrusion 67B of the pawl 67 is positioned within this operating hole 71D. As a result, as the cam plate 71 rotates and displaces, the pawl 67 displaces toward the gear 65 or the opposite side to the gear 65. A cam engagement hole 71E, which engages with a cam 73 (described later), is formed in the center of the first base plate portion 71A in the front-to-rear direction. The rear surface of the second base plate portion 71B forms a rotor engagement surface 71F, which engages with the rotor 69. The cam plate 71 also has a spring locking portion 71G that protrudes from the front end side of the upper end of the second base plate portion 71B toward the cover 77.

[0031] The cam 73 is disposed on the return bracket 75 side with respect to the cam plate 71. The cam 73 is formed in a rectangular plate shape with its thickness extending in the left-right direction and its longitudinal direction extending in the front-rear direction when viewed from the left or right side. A collar insertion hole 73A into which a collar 83 is inserted is formed at the front end of the cam 73. The cam 73, together with the cam plate 71, is rotatably supported by the return bracket 75 and the cover 77 via the collar 83 inserted in the collar insertion hole 73A. A cylindrical engagement protrusion 73B protrudes toward the cam plate 71 from the surface of the rear end of the cam 73 facing the cam plate 71. The engagement protrusion 73B is disposed in the cam engagement hole 71E of the cam plate 71, thereby connecting the cam 73 and the cam plate 71 so that they cannot rotate relative to each other.

[0032] The return bracket 75 includes a return bracket main body 75A formed in the shape of a rectangular plate with the thickness direction in the left-right direction and the longitudinal direction in the up-down direction when viewed from the left or right side, and a cover engagement portion 75B that bends and extends from the upper end of the return bracket main body 75A toward the cover 77. The return bracket main body 75A is formed with two collar insertion holes 75C into which collars 83 are inserted, a shaft insertion hole 75D into which a shaft 85 is inserted, and a rivet insertion hole 75E into which a rivet 89 is inserted.

[0033] The cover 77, which serves as a cover member, is formed in the shape of a rectangular plate with its thickness extending in the left-right direction and its longitudinal direction extending up-down when viewed from the left or right side, and includes a cover main body 77A that covers most of the pawl 67, rotor 69, cam plate 71, etc. from the left side, and a spring locking portion 77B that bends and extends from the upper end of the cover main body 77A toward the side opposite the return bracket 75. The cover 77 also includes a support piece 77C that protrudes rearward from the rear end of the cover main body 77A. The cover main body 77A is formed with two collar insertion holes 77D into which collars 83 are inserted, a shaft insertion hole 77E into which a shaft 85 is inserted, and a rivet insertion hole 77F into which a rivet 89 is inserted.

[0034] The return spring 79 is a tension coil spring. One end of the return spring 79 is engaged with a spring engaging portion 71G of the cam plate 71. The other end of the return spring 79 is engaged with a spring engaging portion 77B of the cover 77. As a result, the tension coil spring is stretched between the cover 77 and the cam plate 71. The biasing force of the return spring 79 urges the cam plate 71 to rotate toward a second position, which will be described later.

[0035] The suspension lock ACT64 is configured to be activated when energized, causing an output portion (not shown) to rotate. The ACT engaging portion 85B of the shaft 85 engages with the output portion of the suspension lock ACT64. This causes the shaft 85 to function as the output shaft of the suspension lock ACT64. When the suspension lock ACT64 is activated, the shaft 85 rotates to one side or the other together with the rotor 69.

[0036] (Operation of locking mechanism 50) Next, the operation of the locking mechanism 50 will be described. Figure 9 shows a state in which the end of the rotor 69 opposite the shaft 85 abuts against the rotor engagement surface 71F of the cam plate 71. In this state, the cam plate 71 is located in the first position A1, and the pawl 67 is located in the unlocked position B1. With the pawl 67 located in the unlocked position B1, the engagement teeth 67C of the pawl 67 are separated from the engagement teeth 65B of the gear 65. Note that hereinafter, the state in which the components of the locking mechanism 50 are located at the positions shown in Figure 9 will be referred to as the unlocked state.

[0037] 9, when the suspension lock ACT64 is actuated, the rotor 69 together with the shaft 85 is rotationally displaced to one side (the direction of arrow C1), thereby changing the contact position between the rotor 69 and the rotor engagement surface 71F of the cam plate 71. Here, when the rotor 69 is rotationally displaced to one side (the direction of arrow C1) together with the shaft 85, as the rotation angle of the rotor 69 to one side increases, the distance from the center of rotation of the rotor 69 to the contact position between the rotor 69 and the rotor engagement surface 71F of the cam plate 71 gradually decreases. As a result, the cam plate 71 is rotationally displaced to one side (the direction of arrow D1) by the biasing force of the return spring 79. When the cam plate 71 is rotationally displaced to one side, the engagement protrusion 67B of the pawl 67 moves to one side along the operating hole 71D while being pressed against the edge of the operating hole 71D of the cam plate 71.

[0038] As a result, the pawl 67 is rotationally displaced toward the gear 65 (toward the arrow E1), and as shown in Fig. 10, the engagement teeth 65B of the pawl 67 engage (mesh) with the engagement teeth 65B of the gear 65. Note that the position of the pawl 67 in a state where the engagement of the engagement teeth 65B of the pawl 67 with the engagement teeth 65B of the gear 65 is complete is referred to as the locked position B2, and the position of the cam plate 71 is referred to as the second position A2. In the following, the state in which the members of the locking mechanism 50 are positioned as shown in Fig. 10 is referred to as the locked state.

[0039] Furthermore, when the cam plate 71 is rotationally displaced to one side (the direction of arrow D1) by the biasing force of the return spring 79, the cam 73 is rotationally displaced to one side together with the cam plate 71. During this process, after the cam 73 abuts against the cam abutment surface 67D of the pawl 67, the cam 73 continues to abut against the cam abutment surface 67D of the pawl 67.

[0040] In a locked state in which the pawl 67 is located at the locked position B2 and the cam plate 71 is located at the second position A2, as shown in FIG. 10 , when the suspension lock ACT64 is activated and the rotor 69 is rotationally displaced together with the shaft 85 toward the other side (the direction of arrow C2), the contact position between the rotor 69 and the rotor engagement surface 71F of the cam plate 71 changes. Here, when the rotor 69 is rotationally displaced together with the shaft 85 toward the other side (the direction of arrow C2), as the rotation angle of the rotor 69 toward the other side increases, the distance from the center of rotation of the rotor 69 to the contact position between the rotor 69 and the rotor engagement surface 71F of the cam plate 71 gradually increases. As a result, the cam plate 71 is rotationally displaced toward the other side (the direction of arrow D2) against the biasing force of the return spring 79. When the cam plate 71 is rotationally displaced toward the other side, the engagement protrusion 67B of the pawl 67 is pressed against the edge of the operating hole 71D of the cam plate 71 and moves toward the other side along the operating hole 71D. As a result, the pawl 67 is rotationally displaced in the opposite direction to the gear 65 (the direction of the arrow E2), and the engagement teeth 65B of the pawl 67 are separated from the engagement teeth 65B of the gear 65. In this way, the cam plate 71 returns to the first position A1, and the pawl 67 returns to the unlocked position B1 (see FIG. 9).

[0041] Furthermore, when the cam plate 71 is rotationally displaced toward the other side (the direction of arrow D2) against the biasing force of the return spring 79, the cam 73 is rotationally displaced toward the other side together with the cam plate 71. During this process, the cam 73 moves away from the cam abutment surface 67D of the pawl 67.

[0042] 11 shows a seat ECU (Electronic Control Unit) 100 and its peripheral configuration. The seat ECU 100 is electrically connected to a seating sensor 122, a buckle sensor 120, a lock sensor 124, a height switch 128, a lock switch 126, an air spring 22, and a suspension lock ACT64.

[0043] The seating sensor 122 is disposed inside the seat cushion 12A. The seating sensor 122 includes an electrode such as a piezoelectric element, and is disposed so that the electrode is located at a portion of the seat cushion 12A that is pressed (a load is applied) by a seated occupant. The seating sensor 122 may be configured with a strain gauge sensor, a capacitance sensor, a camera, or the like, instead of a piezoelectric element. A seat belt device including a seat belt 130 and a seat belt buckle 132 is attached to the vehicle seat 10 (see FIG. 1). The buckle sensor 120 detects whether the seat belt 130 is fastened or detached at the seat belt buckle 132.

[0044] The lock sensor 124 is a limit switch or Hall IC incorporated in the suspension lock ACT64 and indirectly detects whether the locking mechanism 50 is in a locked or unlocked state by detecting the position of the output shaft of the suspension lock ACT64. The lock switch 126 is provided, for example, in an operation unit 134 provided on the right side of the seat cushion 12A and is turned on by an occupant when switching the locking mechanism 50 from a locked state to an unlocked state or when switching the locking mechanism 50 from an unlocked state to a locked state. The lock switch 126 may be a push switch, a toggle switch, a momentary switch, or an alternate switch. The height switch 128 is provided, for example, in the operation unit 134 and is operated by an occupant when instructing a change in the height of the seat cushion of the vehicle seat 10. The height switch 128 is formed, for example, by a limit switch, a variable resistor, or the like. The height switch 128 is an example of a first switch in the present disclosure, and the lock switch 126 is an example of a second switch in the present disclosure.

[0045] The seat ECU 100 changes the height of the seat surface of the vehicle seat 10 by controlling the supply and exhaust of air to the air chamber inside the air spring 22 in response to the operation of the height switch 128. The seat ECU 100 activates the suspension lock ACT64 when switching the lock mechanism 50 from the unlocked state to the locked state, and when switching the lock mechanism 50 from the locked state to the unlocked state.

[0046] The seat ECU 100 includes a CPU (Central Processing Unit) 102, a memory 104 such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and a non-volatile storage unit 106 such as a HDD (Hard Disk Drive) or an SSD (Solid State Drive). The seat ECU 100 also includes an I / F (Interface) unit 108, to which a seating sensor 122, a buckle sensor 120, a lock sensor 124, a height switch 128, a lock switch 126, an air spring 22, and a suspension lock ACT64 are connected. The CPU 102, the memory 104, the storage unit 106, and the I / F unit 108 are each connected to an internal bus 110 and are capable of communicating with each other.

[0047] Furthermore, a seat control program 112 is stored in the storage unit 106 of the seat ECU 100. The seat control program 112 is read from the storage unit 106 and loaded into the memory 104, and the seat control program 112 loaded into the memory 104 is executed by the CPU 102, whereby the seat ECU 100 functions as a determination unit 114 and a control unit 116 shown in Fig. 12 and performs lock switch on processing (Fig. 16), height operation processing (Fig. 17), belt detachment processing (Fig. 18), belt fastening processing (Fig. 19), and occupant change monitoring processing (Fig. 20), which will be described later.

[0048] The determination unit 114 determines whether or not an occupant is seated in the vehicle seat 10. When the determination unit 114 determines that an occupant is seated in the vehicle seat 10, the control unit 116 stores the position of the locking mechanism 50 in the memory 104, and when the seat belt 120 is unfastened, causes the suspension lock ACT 64 to displace the locking mechanism 50 to the locked position, and when the seat belt 120 is fastened, causes the suspension lock ACT 64 to displace the locking mechanism 50 to the unlocked position if the position stored in the memory 104 is the unlocked position. The control unit 116 is an example of a control unit in the present disclosure.

[0049] Next, the operation of this embodiment will be described. When an occupant is seated in the vehicle seat 10 and the locking mechanism 50 is in an unlocked state, the height of the seat cushion 12A of the vehicle seat 10 is stabilized at a height where the load on the suspension 14, such as the weight of the occupant, is balanced with the internal pressure of the air chamber of the air spring 22 of the suspension 14, as shown in FIG. 13(A). When the occupant operates the height switch 128 to increase the height of the seat cushion 12A, air is supplied to the air spring 22 in response to the operation of the height switch 128, as shown in FIG. 13(B), thereby increasing the internal pressure of the air spring 22. As a result, the balance between the load on the suspension 14 and the internal pressure of the air spring 22 is disrupted, and the suspension 14 extends upward to a position where the load on the suspension 14 and the internal pressure of the air spring 22 are balanced (a position where the weight gap is eliminated), and the height of the seat cushion 12A increases as shown in FIG. 13(C).

[0050] Furthermore, when the occupant operates the height switch 128 to lower the height of the seat cushion 12A from the stable state shown in Fig. 13(D), air is released from the air spring 22 in response to the operation of the height switch 128, thereby lowering the internal pressure of the air spring 22, as shown in Fig. 13(E). As a result, the balance between the load on the suspension 14 and the internal pressure of the air spring 22 is lost, and the suspension 14 contracts downward to a position where the load on the suspension 14 and the internal pressure of the air spring 22 are balanced (a position where the weight gap is eliminated), and the height of the seat cushion 12A is lowered as shown in Fig. 13(F).

[0051] On the other hand, when the locking mechanism 50 is in the unlocked state, when an occupant seated in the vehicle seat 10 stands up to get out of the vehicle, the load on the suspension 14 decreases, causing the vehicle seat 10 to rise, making it difficult to get out of the vehicle. In particular, in a truck, which is an example of a vehicle in which the vehicle seat 10 is installed, the distance between the feet of the seated occupant and the steering wheel is short due to the vehicle layout as shown in Fig. 14, so when the vehicle seat 10 rises, the occupant's feet become pinched between the steering wheel and the vehicle seat 10, making it significantly difficult to get out of the vehicle.

[0052] Some vehicle seats are equipped with an automatic height adjustment function that automatically supplies and exhausts air to return the seat height to its original position when the balance between the load on the suspension and the internal pressure of the air spring is lost. However, the automatic height adjustment function operates after the balance is lost, and in the above example, the seat lowers to its original position after the occupant's feet are pinched between the steering wheel and the vehicle seat 10, so it does not contribute to improving ease of exiting the vehicle.

[0053] Furthermore, if the vehicle seat 10 remains raised when an occupant gets into the vehicle, the occupant's feet will interfere with at least one of the steering wheel and the vehicle seat 10, which will also deteriorate the ease of getting into the vehicle. In particular, if the vehicle on which the vehicle seat 10 is mounted is a vehicle used at a construction site, such as a truck, the occupant will often repeat the work pattern of "getting in → driving → getting out → working →" in a short period of time, as shown in Fig. 15, for example. In this case, the occupant will get in and out of the vehicle frequently, and the poor ease of getting in and out of the vehicle will have a significant impact on work efficiency.

[0054] On the other hand, the technology described in Patent Document 1 displaces the locking mechanism to a locked position by an actuator when the seatbelt is unfastened, thereby preventing the seat from rising when a seated occupant stands up to exit the vehicle, thereby improving the ease of getting in and out of the vehicle. However, with this technology, the locking mechanism is in the locked position when the occupant is seated in the seat. Therefore, if the occupant wants to change the seat height while seated, the occupant must operate the locking mechanism to displace it to the unlocked position, which poses a problem of reduced operability.

[0055] To solve the above problem, the seat ECU 100 according to this embodiment performs the following process. First, with reference to FIG. 16, the lock switch ON process executed by the seat ECU 100 when the lock switch 126 is turned ON by the occupant will be described.

[0056] In step 200 of the lock switch-on processing, the determination unit 114 acquires information indicating the on / off state of the seating sensor 122 from the seating sensor 122. Then, in step 202, the determination unit 114 determines whether the seating sensor 122 is in the on state. In this embodiment, the seating sensor 122 is in the on state when a load is applied to the seat cushion 12A, and is in the off state when no load is applied to the seat cushion 12A. If the determination in step 202 is negative, the lock switch-on processing ends.

[0057] If the determination in step 202 is affirmative, the process proceeds to step 204. In step 204, the determination unit 114 acquires information indicating the on / off state of the buckle sensor 120 from the buckle sensor 120. Then, in step 206, the determination unit 114 determines whether the buckle sensor 120 is in the off state. In this embodiment, the buckle sensor 120 is in the off state when the seat belt 130 is fastened, and is in the on state when the seat belt 130 is not fastened. If the determination in step 206 is negative, the lock switch on processing ends.

[0058] The above-described lock switch-on processing prevents the lock mechanism 50 from being displaced to the unlock position even if an occupant who has performed an operation to displace the lock mechanism 50 to the locked position while seated in the vehicle seat 10, dismounts from the vehicle, and then mistakenly performs an operation to displace the lock mechanism 50 to the unlocked position when re-entering the vehicle before being seated. Note that in the above-described lock switch-on processing, the order in which steps 200, 202 and steps 204, 206 are performed is not limited to the order shown in FIG. 16 , and steps 204, 206 may be performed before steps 200, 202.

[0059] If the determination in step 206 is affirmative, the process proceeds to step 208. In step 208, the control unit 116 acquires information indicating the state of the locking mechanism 50 from the lock sensor 124. In step 210, the control unit 116 determines whether the state of the locking mechanism 50 is locked or unlocked, and branches depending on the determination result. If the locking mechanism 50 is unlocked, the process proceeds from step 210 to step 212. In step 212, the control unit 116 controls the operation of the suspension lock ACT 64 so that the locking mechanism 50 transitions from the unlocked state to the locked state. If the locking mechanism 50 is locked, the process proceeds from step 210 to step 214, and in step 214, the control unit 116 controls the operation of the suspension lock ACT 64 so that the locking mechanism 50 transitions from the locked state to the unlocked state.

[0060] After the processing of step 212 or step 214 is completed, the process proceeds to step 216. Then, in step 216, the control unit 116 writes the current state of the lock mechanism 50 as the seated state in the memory 104, and ends the lock switch on processing. By this lock switch on processing, the position of the lock mechanism 50 (seated state) in the state in which the determination unit 114 determines that an occupant is seated in the vehicle seat 10 is stored in the memory 104.

[0061] Next, referring to FIG. 17, a description will be given of the height operation process executed by the seat ECU 100 when the height switch 128 is operated by the occupant. In step 230 of the height operation process, the control unit 116 obtains information indicating the state of the lock mechanism 50 from the lock sensor 124. In step 232, the control unit 116 determines whether the lock mechanism 50 is locked or unlocked, and branches depending on the determination result. If the lock mechanism 50 is unlocked, the control unit 116 controls the supply of air to or the exhaust of air from the air chamber of the air spring 22 in accordance with the operation of the height switch 128 by the occupant, and then ends the height operation process.

[0062] On the other hand, if the locking mechanism 50 is in the locked state, the process proceeds from step 232 to step 234. In step 234, the control unit 116 controls the operation of the suspension lock ACT64 so that the locking mechanism 50 changes from the locked state to the unlocked state. After switching the locking mechanism 50 to the unlocked state, the control unit 116 controls the supply of air to or the exhaust of air from the air chamber of the air spring 22 in response to the operation of the height switch 128 by the occupant.

[0063] With the above-described height operation processing, when the height switch 128 is operated while the locking mechanism 50 is in the locked position, the suspension lock ACT64 displaces the locking mechanism 50 to the unlocked position before air is supplied to or exhausted from the air chamber of the air spring 22, thereby preventing a weight gap from occurring and preventing a sudden change in the height of the vehicle seat 10.

[0064] In step 236, the control unit 116 determines whether the height switch 128 has been operated by the occupant. If the determination in step 236 is negative, the determination in step 236 is repeated. During this time, the control unit 116 controls the supply of air to or the exhaust of air from the air chamber of the air spring 22 in accordance with the operation of the height switch 128 by the occupant.

[0065] Furthermore, if the determination in step 236 is affirmative, the process proceeds to step 238. In step 238, the control unit 116 starts timing the time (no-operation time) since the occupant stopped operating the height switch 128. In step 240, the control unit 116 determines whether the height switch 128 is operated again before the no-operation time reaches a predetermined time. If the determination in step 240 is affirmative, the process returns to step 236. If the no-operation time reaches the predetermined time, the determination in step 240 is negative, and the process proceeds to step 242.

[0066] In step 242, the control unit 116 reads from the memory 104 the state (seated state) of the locking mechanism 50 that is written therein. In step 244, the control unit 116 determines whether the seated state read from the memory 104 is locked or unlocked, and branches depending on the determination result. If the seated state is locked, the process proceeds from step 244 to step 246. In step 246, the control unit 116 controls the operation of the suspension lock ACT64 so that the locking mechanism 50 changes from the unlocked state to the locked state, and ends the height operation process. On the other hand, if the seated state is unlocked, the control unit 116 skips step 246 and ends the height operation process.

[0067] 18, a description will be given of the belt unfastening process executed by the seat ECU 100 when the buckle sensor 120 detects that the occupant has operated the seat belt buckle 132 to unfasten the seat belt 130. In step 260 of the belt unfastening process, the determination unit 114 acquires information indicating the on / off state of the seat occupancy sensor 122 from the seat occupancy sensor 122, and in the next step 262, the determination unit 114 determines whether the seat occupancy sensor 122 is in the on state (seat occupancy detection state). If the determination in step 262 is negative, the belt unfastening process ends.

[0068] On the other hand, if the seating sensor 122 is in the ON state, the determination in step 262 is affirmative and the process proceeds to step 264. In step 264, the control unit 116 obtains information indicating the state of the locking mechanism 50 from the lock sensor 124. In step 266, the control unit 116 determines whether the locking mechanism 50 is in the locked state or the unlocked state, and branches depending on the determination result. If the locking mechanism 50 is in the unlocked state, the process branches from step 266 to step 268. Then, in step 268, the control unit 116 controls the operation of the suspension lock ACT64 so that the locking mechanism 50 changes from the unlocked state to the locked state, and the belt removal process ends. On the other hand, if the locking mechanism 50 is in the locked state, step 268 is skipped and the belt removal process ends.

[0069] By the above-described belt removal process, when the seat belt 130 is removed, the locking mechanism 50 is displaced to the locking position by the suspension lock ACT64, so that the vehicle seat 10 is prevented from rising when the seated occupant stands up.

[0070] 19, the belt fastening process executed by the seat ECU 100 when the buckle sensor 120 detects that the occupant has fastened the seat belt 130 will be described. In step 280 of the belt fastening process, the determination unit 114 acquires information indicating the on / off state of the seat occupancy sensor 122 from the seat occupancy sensor 122. In step 282, the determination unit 114 determines whether the seat occupancy sensor 122 is in the on state (seat occupancy detection state). If the determination in step 282 is negative, the belt fastening process ends.

[0071] On the other hand, if the seating sensor 122 is in the ON state, the determination in step 282 is affirmative and the process proceeds to step 284. In step 284, the control unit 116 reads from the memory 104 the state (seated state) of the locking mechanism 50 that is written in the memory 104. In step 286, the control unit 116 determines whether the seated state read from the memory 104 is the locked state or the unlocked state, and branches depending on the determination result.

[0072] If the seated state is the unlocked state, the process proceeds from step 286 to step 288. In step 288, the control unit 116 controls the operation of the suspension lock ACT64 so that the locking mechanism 50 is displaced to the unlocked state, and the belt-fastening process ends. On the other hand, if the seated state is the locked state, the process proceeds from step 286 to step 290. In step 290, the control unit 116 controls the operation of the suspension lock ACT64 so that the locking mechanism 50 is displaced to the locked state, and the belt-fastening process ends.

[0073] By the above-mentioned belt fastening process, when the occupant wishes to change the seat height while seated (when the seated state is unlocked), the occupant does not need to perform any operation to displace the locking mechanism 50 to the unlocked position while seated, thereby preventing a deterioration in operability.

[0074] Next, referring to Figure 20, an occupant change monitoring process executed by the seat ECU 100 while, for example, the vehicle ignition switch is on will be described. In step 300 of the occupant change monitoring process, the control unit 116 acquires information indicating the on / off state of the seat occupancy sensor 122 from the seat occupancy sensor 122. In step 302, the control unit 116 determines whether the state of the seat occupancy sensor 122 has changed from on to off. If the determination in step 302 is negative, the process returns to step 300, and steps 300 and 302 are repeated until the determination in step 302 is positive.

[0075] If the determination in step 302 is positive, the process proceeds to step 304. In step 304, the control unit 116 starts measuring the time during which no occupant is seated in the vehicle seat 10 (unseated time). In step 306, the control unit 116 acquires information indicating the on / off state of the seating sensor 122 from the seating sensor 122. In step 308, the control unit 116 determines whether the state of the seating sensor 122 has changed from off to on. If the determination in step 308 is negative, the process returns to step 306, and steps 306 and 308 are repeated until the determination in step 308 is positive.

[0076] If the determination in step 308 is positive, the process proceeds to step 310. In step 310, the control unit 116 determines whether the unoccupied time is equal to or longer than a first predetermined time. The first predetermined time is set to a minimum time required for an occupant seated in the vehicle seat 10 to be replaced, and is, for example, six seconds. If the determination in step 310 is negative, it is highly unlikely that the occupant seated in the vehicle seat 10 has been replaced, so the process returns to step 300 and repeats the processes from step 300 onwards.

[0077] Furthermore, if the determination in step 310 is positive, there is a possibility that the occupant seated in the vehicle seat 10 has changed. Therefore, the process proceeds to step 312, where the process waits for a second predetermined time. The second predetermined time is set to the time required for an occupant who has once sat in the vehicle seat 10 to reseat, and is, for example, one second. In step 314, the control unit 116 controls the operation of the suspension lock ACT64 so that the locking mechanism 50 is shifted from the locked state to the unlocked state.

[0078] In step 316, the control unit 116 waits for a third predetermined time. The third predetermined time is set to the time required for the weight gap to be eliminated, and is, for example, 0.2 seconds. Then, in step 318, the control unit 116 controls the operation of the suspension lock ACT64 so that the lock mechanism 50 is shifted from the unlocked state to the locked state, and the occupant monitoring process ends.

[0079] When the occupant change monitoring process described above changes the occupant seated in the vehicle seat 10, the weight gap is eliminated before the vehicle starts moving by allowing the first predetermined time or more to pass between the time the occupant leaves the vehicle seat 10 and the time the occupant re-seats the vehicle seat 10. Therefore, when the locking mechanism is displaced to the unlocked position while the vehicle is moving, it is possible to prevent the seat height from changing while the vehicle is moving.

[0080] As described above, in this embodiment, the suspension 14 is capable of changing the height of the vehicle seat 10 by supplying or discharging air to or from the air chamber of the air spring 22 disposed below the vehicle seat 10 in response to operation of the height switch 128, which instructs a change in the height of the vehicle seat 10. The locking mechanism 50 is displaceable between a locked position, which locks the vehicle seat 10 against changes in height, and an unlocked position, which unlocks the locking mechanism, and the suspension lock ACT 64 displaces the locking mechanism 50. The control unit 116 stores the position of the locking mechanism 50 in the memory 104 when the determination unit 114 determines that an occupant is seated in the vehicle seat 10, and displaces the locking mechanism 50 by the suspension lock ACT 64 to the locked position when the seat belt 130 is unfastened, and displaces the locking mechanism 50 by the suspension lock ACT 64 to the unlocked position when the seat belt 130 is fastened and the position stored in the memory 104 is the unlocked position. This eliminates the need for the occupant to perform an operation to displace the locking mechanism to the unlocked position when seated, when the occupant desires to change the height of the vehicle seat 10 while seated (when the seated state is unlocked), thereby preventing a deterioration in operability.

[0081] In this embodiment, the determination unit 114 determines that an occupant is seated in the vehicle seat 10 when the seating sensor 122 detects that an occupant is seated in the vehicle seat 10 and the buckle sensor 120 detects that the seat belt 130 is fastened. This makes it possible to accurately determine that an occupant is seated in the vehicle seat 10.

[0082] In this embodiment, the lock sensor 124 is incorporated into the suspension lock ACT 64, and detects the position of the output shaft of the suspension lock ACT 64 to indirectly detect whether the lock mechanism 50 is in the locked position or the unlocked position, and the control unit 116 recognizes the position of the lock mechanism 50 based on the signal from the lock sensor 124. This allows the lock sensor 124, and therefore the lock mechanism 50, to be made smaller.

[0083] In the above embodiment, in the lock switch on processing (FIG. 16), the determination unit 114 determines that an occupant is seated in the vehicle seat 10 when the seating sensor 122 detects that an occupant is seated in the vehicle seat 10 and the buckle sensor 120 detects that the seat belt 130 is fastened. However, the present invention is not limited to this, and the determination unit 114 may be configured to determine that an occupant is seated in the vehicle seat 10 when at least one of the following conditions is satisfied: "the seating sensor 122 detects that an occupant is seated in the vehicle seat 10" and "the buckle sensor 120 detects that the seat belt 130 is fastened." [Explanation of symbols]

[0084] 10 Vehicle seats 14 Suspension (air suspension mechanism) 22 Air spring 50 Locking mechanism 64 Suslock ACT (actuator) 100 seat ECU 104 Memory (storage unit) 114 Judgment section 116 Control Unit 120 Buckle sensor 122 Seat sensor 124 Lock Sensor 126 Lock Switch 128 Height Switch 130 Seatbelt

Claims

1. an air suspension mechanism capable of changing the height of the seat by supplying and exhausting air to an air chamber disposed below the seat; a locking mechanism that is displaceable to a locking position that locks the seat height from being changed or to an unlocking position that releases the lock; an actuator that displaces the locking mechanism; a control unit that stores the position of the locking mechanism in a memory unit when the determination unit determines that an occupant is seated in the seat, and displaces the locking mechanism by the actuator to a locked position when a seat belt is removed, and displaces the locking mechanism by the actuator to the unlocked position when the seat belt is fastened and the position stored in the memory unit is an unlocked position; 1. A vehicle seat including:

2. 2. The vehicle seat according to claim 1, wherein the determination unit determines that an occupant is seated in the seat when an occupant is detected to be seated in the seat by an occupancy sensor and when a seat belt is detected to be fastened by a buckle switch.

3. a lock sensor incorporated in the actuator that detects a position of an output shaft of the actuator to indirectly detect whether the locking mechanism is in a locked position or an unlocked position; 3. The vehicle seat according to claim 1, wherein the control unit recognizes the position of the lock mechanism based on a signal from the lock sensor.

Images