Vehicle seat

Abstract

One aspect of the present disclosure provides a vehicle seat including an electric motor, a movable portion, an operation switch, and a control portion. The movable part is configured to move in a direction corresponding to a rotation direction of the electric motor by receiving a driving force from the electric motor. The control unit rotates the electric motor in a first rotational direction in response to the operation switch outputting an ON signal. The control unit is configured to execute reverse control in response to the control unit detecting that the movable unit is in a state in which the movement thereof is blocked at a first preset time. In the reverse control, the control unit rotates the electric motor in a second rotational direction opposite to the first rotational direction.

Description

Technical Field

[0001] The present disclosure relates to a vehicle seat configured to be mounted on a vehicle. Background Art

[0002] Japanese Patent Application Laid-Open No. 2008-136325 discloses a seat device in which, when it is detected that the movement of a movable part is blocked by a foreign object, the rotation direction of the electric motor is immediately reversed, thereby reversing the movement direction of the movable part. Summary of the invention

[0003] Immediately reversing the movable part in response to detection of the above-mentioned movement obstruction may cause the movable part to move in the opposite direction to the user's intention. Therefore, the user may feel very uncomfortable with the above-mentioned movement of the movable part.

[0004] One aspect of the present disclosure is to provide a vehicle seat that can reduce discomfort felt by a user due to movement of a movable portion of the vehicle seat in response to movement obstruction detection.

[0005] One aspect of the present disclosure provides a vehicle seat configured to be mounted on a vehicle. The vehicle seat includes an electric motor, a movable part, an operation switch, and a control unit. The electric motor is configured to generate a driving force. The movable part is configured to move in a direction corresponding to the rotation direction of the electric motor by receiving the driving force from the electric motor. The operation switch is configured to be (i) manually operated by a user and (ii) output an on signal in response to the operation switch being manually operated. The control unit rotates the electric motor in a first rotation direction in response to the operation switch outputting the on signal. The control unit is configured to detect that the movable part is in a movement-blocked state based on at least (i) the operation switch outputting the on signal and (ii) the rotation of the electric motor has stopped. The control unit is configured to perform reverse control in response to the control unit detecting that the movable part is in a movement-blocked state at a first preset time. The movable part in the movement-blocked state cannot move in the direction corresponding to the first rotation direction of the electric motor. The reverse rotation control is configured such that the control unit rotates the electric motor in a second rotation direction opposite to the first rotation direction.

[0006] In the vehicle seat of the above structure, when the movable part is detected to be in a state of movement obstruction, the movable part does not immediately move in the reverse direction. Therefore, the vehicle seat can reduce the discomfort of the user caused by the movement of the movable part in response to the movement obstruction detection.

[0007] The switch-on signal may be a negative logic signal (or a low-level valid signal) or a positive logic signal (or a high-level valid signal).

[0008] The first rotation direction may correspond to a forward rotation direction of the electric motor, or may correspond to a reverse rotation direction of the electric motor.

[0009] The control unit may be configured to be capable of executing the reverse control at least when the vehicle is stopped.

[0010] The movable part may be a seat body configured to move in the front-rear direction of the vehicle seat in accordance with the rotation direction of the electric motor. The control unit may be configured to perform the reverse control at least when the seat body moves toward the rear of the vehicle seat.

[0011] The movable portion may be a seat back, the seat back being configured to (i) support the back of a seated person and (ii) tilt and move relative to the front-rear direction of the vehicle seat in accordance with the rotation direction of the electric motor. The control unit may be configured to be able to perform the reverse control at least when the seat back is tilted and moved toward the rear of the vehicle seat.

[0012] The movable part may be a seat body configured to move in the vertical direction of the vehicle seat in accordance with the rotation direction of the electric motor. The control unit may be configured to perform the reverse control at least when the seat body moves downward of the vehicle seat.

[0013] The control unit may be configured to detect that the movable part is in the movement blocked state based on the movable part maintaining the movement blocked state for a preset detection time. The vehicle seat having the control unit configured as above can suppress erroneous detection that the movable part is in the movement blocked state.

[0014] The vehicle seat may include a rotation sensor configured to output a pulse signal in association with the rotation of the electric motor. While the operation switch is outputting the on signal, the movable portion in a movement-blocked state may prevent the rotation sensor from outputting the pulse signal.

[0015] While the operation switch is outputting the on signal, the energizing current flowing to the electric motor may continue to increase through the movable portion in a state in which its movement is blocked.

[0016] The control unit may be configured to output a supply voltage having a first magnitude (or a first absolute value) to the electric motor in response to (i) the operation switch outputting the on signal and (ii) the control unit not detecting that the movable unit is in a state where movement is blocked. The control unit may be configured to execute a motor load reduction control before executing the reverse control in response to the control unit detecting that the movable unit is in a state where movement is blocked. The motor load reduction control may be configured such that the control unit outputs the supply voltage having a second magnitude (or a second absolute value) smaller than the first magnitude to the electric motor.

[0017] In the vehicle seat including the control unit having the above-described structure, when the movable unit is in a state where movement is blocked, the current flowing to the electric motor can be reduced, thereby suppressing damage to the electric motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the vehicle seat according to the first embodiment.

[0019] Figure 2 It is a schematic diagram of the control device of the electric motor according to the first embodiment.

[0020] Figure 3 This is a timing chart showing control of the electric motor in the first embodiment.

[0021] Figure 4 It is a timing chart showing control of the electric motor in the second embodiment.

[0022] Figure 5 It is a timing chart showing control of the electric motor in the third embodiment. DETAILED DESCRIPTION

[0023] Exemplary embodiments of the present disclosure are described below with reference to the accompanying drawings.

[0024] The embodiments described below are merely examples of embodiments to illustrate the technical scope of the present disclosure. That is, the technical solutions and the like described in the claims are not limited to the specific structures or configurations and the like shown in the following embodiments.

[0025] The following embodiments provide examples of a vehicle seat configured to be installed in a vehicle (not shown). At least one component or portion is provided unless it is stated in advance that "only one" is provided.

[0026] That is, unless it is stated in advance that there is only one, at least two of the components are provided. The vehicle seat device shown in the present disclosure includes at least components or parts and other constituent elements described with reference numerals, and at least one of the structural parts shown in the figure.

[0027] 1. First Implementation Method

[0028] 1-1. Overview of vehicle seats

[0029] 1-1-1. Structure of vehicle seats

[0030] like Figure 1 As shown, the vehicle seat 1 includes at least a seat body 2 and a pair of slide devices 3. The seat body 2 includes at least a seat cushion 4 and a seat back 5, and is configured for a user to sit on.

[0031] The seat cushion 4 is configured to support the buttocks of a seated person. The seat back 5 is configured to support the back of a seated person. The seat back 5 is connected to the rear end side of the seat cushion 4 in a tiltable (or rotatable) manner.

[0032] More specifically, the seat back 5 rotates at its lower end and is tiltably movable (or tiltable) relative to the seat cushion 4 in the front-rear direction of the vehicle seat 1. The pair of slide devices 3 slidably supports the seat body 2.

[0033] The pair of slide devices 3 is disposed at one end side and the other end side of the seat body 2 in the width direction to support the seat body 2. Each slide device 3 includes a fixed rail 3A and a movable rail 3B.

[0034] Each fixed rail 3A is a rail member fixed to the vehicle. Each movable rail 3B is slidably mounted on the corresponding fixed rail 3A. The seat body 2 is connected to each movable rail 3B via a plurality of lifting links 6 .

[0035] In the first embodiment, each fixed rail 3A is fixed to the vehicle in a state where the longitudinal direction of the fixed rail 3A coincides with the front-rear direction of the vehicle seat 1. Therefore, the seat body 2 of the first embodiment is slidable along the front-rear direction of the vehicle seat 1.

[0036] The upper end of each lifting link 6 is rotatably connected to the seat cushion 4, and the lower end thereof is rotatably connected to the corresponding movable rail 3B. Therefore, the seat cushion 4 moves in the vertical direction of the vehicle seat 1 by the lifting links 6 rotating in conjunction with each other.

[0037] Therefore, the seat body 2 and the seat back 5 each correspond to a movable portion of the vehicle seat 1. The seat body 2 is movable in the front-rear direction and the up-down direction of the vehicle seat 1. The seat back 5 is tiltable relative to the front-rear direction of the vehicle seat 1.

[0038] The vehicle seat 1 includes a first electric motor 7A to a third electric motor 7C. The first electric motor 7A is configured to generate a driving force for tilting the seat back 5 relative to the front-rear direction of the vehicle seat 1. The second electric motor 7B is configured to generate a driving force for moving the seat body 2 along the up-down direction of the vehicle seat 1. The third electric motor 7C is configured to generate a driving force for moving the seat body 2 along the front-rear direction of the vehicle seat 1. In other embodiments, the vehicle seat 1 may include only one or two of the first electric motor 7A to the third electric motor 7C. In another embodiment, the vehicle seat 1 may include at least one additional electric motor in addition to the first electric motor 7A to the third electric motor 7C.

[0039] The term “electric motor 7 ” refers to any one of the first to third electric motors 7A to 7C, and the term “movable portion 8 ” refers to a movable portion that receives a driving force from the “electric motor 7 ” to move, that is, the seat body 2 or the seat back 5 .

[0040] That is, when the electric motor 7 is the first electric motor 7A, the movable portion 8 is the seat back 5 . When the electric motor 7 is the second electric motor 7B or the third electric motor 7C, the movable portion 8 is the seat body 2 .

[0041] 1-1-2. Overview of Control of Moving Parts

[0042] Figure 2 A control device for an electric motor 7 according to a first embodiment is shown. The control device includes at least a control unit 10, an operation switch 11, and a rotation sensor 12. The control unit 10 is configured to control the electric motor 7.

[0043] More specifically, in the first embodiment, the control unit 10 is an electronic control unit in the form of a microcomputer including a CPU, a ROM (read only memory), and a RAM (random access memory). Software for causing the control unit 10 to execute the reverse control described later is pre-stored in a non-volatile storage unit such as the ROM. The control unit 10 receives a signal (not shown) indicating the state of the vehicle such as the moving speed and acceleration of the vehicle.

[0044] The operation switch 11 is configured to output an operation signal to the control unit 10 when manually operated by a user. The operation signal is a signal for rotating the electric motor 7 in the forward direction or the reverse direction.

[0045] When the operation signal is output, the control unit 10 supplies power to the electric motor 7 according to the operation signal to rotate the electric motor 7 forward or reversely. When the operation signal is not output, the control unit 10 stops supplying power to the electric motor 7 to stop the electric motor 7.

[0046] The rotation sensor 12 is configured to detect the rotation of the electric motor 7 and output a pulse signal to the control unit 10. More specifically, the rotation sensor 12 outputs a series of pulses. The number of pulses included in the series of pulses is proportional to the rotation speed of the electric motor 7. The control unit 10 determines whether the electric motor 7 is rotating based on the pulse signal. More specifically, the control unit 10 recognizes the rotation speed of the electric motor 7 based on the number of pulses received by the control unit 10 per unit time.

[0047] 1-2. Details of electric motor control

[0048] When the rotation direction of the electric motor 7 that is rotating in the forward direction or the reverse direction is reversed, the moving direction of the movable portion 8 is also reversed.

[0049] like Figure 3 As shown, in the first embodiment, the control unit 10 performs the reverse rotation control in response to the ON signal being continuously output from the operation switch 11 until the first predetermined time has passed since the obstruction was detected. The rotation of the electric motor 7 is reversed by the reverse rotation control.

[0050] The on signal refers to an operation signal output from the operating switch 11 for operating the electric motor 7. When receiving the on signal, the control unit 10 rotates the electric motor 7 forward or reverse. In the first embodiment, the operating switch 11 has a low-level active switch circuit, which is configured to output a negative logic signal (for example, a signal with a voltage of 0 volts) as the on signal. In other embodiments, the operating switch 11 may have a high-level active switch circuit, which is configured to output a positive logic signal (for example, a signal with a voltage of 5 volts) as the on signal.

[0051] The obstruction detection time refers to the time when the control unit 10 determines that (i) the on signal is being output and (ii) the electric motor 7 has stopped. Specifically, when the control unit 10 receives the on signal, it supplies the power supply voltage to the electric motor 7. When the movable unit 8 is not in a state where its movement is obstructed, the electric motor 7 rotates, and the control unit 10 periodically receives the pulse signal.

[0052] However, if the movable part 8 is in its movement blocked state, the rotation sensor 12 does not output a pulse signal or outputs a pulse signal irregularly. When the duration of this state from the time of occurrence exceeds a preset detection time, the control part 10 detects that the movable part 8 is in its movement blocked state.

[0053] In the first embodiment, the control unit 10 can perform the reverse control when (i) the vehicle is stopped and (ii) the movable unit 8 is moving in a direction where its movement may be blocked. That is, the control unit 10 does not perform the reverse control when the vehicle is moving.

[0054] Examples of "the movable portion 8 moving in a direction in which its movement may be obstructed" include: (i) when the seat body 2 moves toward the rear of the vehicle seat 1; (ii) when the seat body 2 moves downward of the vehicle seat 1; and (iii) when the seat back 5 tilts toward the rear of the vehicle seat 1.

[0055] 1-3. Features of the first embodiment

[0056] In the vehicle seat 1 of the first embodiment, the reverse control is performed in response to the ON signal being continuously output until the first predetermined time has passed from the detection of the obstruction. Therefore, the vehicle seat 1 can reduce the user's discomfort caused by the movement of the movable part 8 in response to the detection of the movement obstruction.

[0057] In the first embodiment, the operating switch 11 outputs a negative logic signal as an on signal. Therefore, even when a short circuit occurs between the circuit of the operating switch 11 and the reference ground (GND) of the electrical system (not shown) of the vehicle seat 1, the operating switch 11 can output an on signal. The above-mentioned on signal is not the on signal desired by the user.

[0058] In the first embodiment, even if the electric motor 7 is operated by an on signal not intended by the user, the reverse control is performed in response to the on signal being continuously output until the first predetermined time has passed from the time of the obstruction detection. As a result, the user's discomfort with the above-mentioned operation can be reduced.

[0059] 2. Second Implementation Method

[0060] like Figure 3 As shown, in the first embodiment, after detecting that the movable portion 8 is in a state where its movement is blocked, the control portion 10 does not change the power supply voltage supplied to the electric motor until the reverse rotation control is performed.

[0061] In this regard, Figure 4As shown, the control unit 10 of the second embodiment performs the motor load reduction control from the time of obstruction detection until the start of the reverse control. In the motor load reduction control, the control unit 10 makes the magnitude (absolute value) of the power supply voltage smaller than the magnitude of the power supply voltage before the obstruction detection. More specifically, if the power supply voltage before the obstruction detection is, for example, +12 volts, the power supply voltage during the motor load reduction control is changed to, for example, +3 volts, 0 volts, or -3 volts. The +3 volt power supply voltage has a polarity that causes the electric motor 7 to rotate forward. The -3 volt power supply voltage has a polarity that causes the electric motor 7 to rotate reversely. The magnitude of the power supply voltage during the reverse control is greater than the magnitude of the power supply voltage during the motor load reduction control.

[0062] In the vehicle seat 1 of the second embodiment, the load on the electric motor 7 is reduced. In the second embodiment, when (i) the vehicle is stopped and (ii) the movable part 8 is moving in a direction where its movement may be blocked, the reverse control and the motor load reduction control are executed. Software for causing the control unit 10 to execute the motor load reduction control is pre-stored in a non-volatile storage unit such as a ROM.

[0063] 3. Third Implementation Method

[0064] In the first and second embodiments described above, the rotation sensor 12 is used to detect that the movable portion 8 is in a state where its movement is blocked. Figure 5 As shown, the change in the energized current flowing through the electric motor 7 is used to detect that the movable portion 8 is in a movement-impeded state.

[0065] When the rotation of the electric motor 7 stops while the power supply voltage is supplied to the electric motor 7, the impedance of the electric motor 7 decreases, and the current flowing through the electric motor 7 increases. The control unit 10 of the third embodiment is configured to detect that the movable unit 8 is in a state where its movement is blocked in response to the current continuing to increase during a predetermined detection time.

[0066] 4. Other Implementation Methods

[0067] In the first to third embodiments, the seat body 2 and the seat back 5 are exemplified as the movable portion 8. However, the movable portion of the present disclosure is not limited to the seat body and the seat back, and may be other components of the vehicle seat such as a leg support or a headrest.

[0068] In the first to third embodiments, the control unit 10 is configured to perform the reverse control when (i) the vehicle is stopped and (ii) the movable unit 8 is moving in a direction in which its movement is likely to be blocked. However, the present disclosure is not limited thereto. The control unit 10 may be configured to perform the reverse control and / or the motor load reduction control, for example, when (i) the vehicle is moving and / or (ii) regardless of the moving direction of the movable unit 8.

[0069] The vehicle seat of the present disclosure can be applied to a vehicle seat configured to be installed in other types of vehicles such as railway vehicles, ships, and aircraft, as well as a fixed seat used in theaters or homes.

[0070] In addition, the present disclosure is not limited to the first to third embodiments as long as it complies with the disclosure of the first to third embodiments. At least two of the first to third embodiments may be combined. Any of the illustrated configurations or configurations described with reference symbols may be abolished in any one of the first to third embodiments.

Claims

1. A vehicle seat, which is configured to be installed in a vehicle, wherein the vehicle seat is characterized by comprising: an electric motor configured to generate a driving force; a movable portion configured to move in a direction corresponding to a rotation direction of the electric motor by receiving the driving force from the electric motor; an operating switch configured to (i) be manually operated by a user and (ii) output an on signal in response to the operating switch being manually operated; a control unit that rotates the electric motor in a first rotation direction in response to the operation switch outputting the on signal, The control unit is configured to detect that the movement of the movable unit is blocked based on at least (i) the operation switch is outputting the on signal and (ii) the rotation of the electric motor has stopped. and executing reverse control in response to the control unit detecting that the movable unit is in a state where movement is blocked at a first preset time, The movable portion in the movement-blocked state cannot move in the direction corresponding to the first rotation direction of the electric motor, and the reverse rotation control is configured such that the control portion rotates the electric motor in a second rotation direction opposite to the first rotation direction.

2. The vehicle seat according to claim 1, characterized in that: The control unit is configured to be capable of executing the reverse control at least when the vehicle is stopped.

3. The vehicle seat according to claim 1, characterized in that: The movable part is a seat body, and the seat body is configured to move along the front-rear direction of the vehicle seat in accordance with the rotation direction of the electric motor. The control unit is configured to be capable of executing the reverse control at least when the seat body moves rearward of the vehicle seat.

4. The vehicle seat according to claim 1, characterized in that: The movable portion is a seat back, and the seat back is configured to (i) support the back of a seated person, and (ii) tilt and move relative to the front-rear direction of the vehicle seat in accordance with the rotation direction of the electric motor. The control unit is configured to be capable of executing the reverse control at least when the seat back is tilted and moved rearward of the vehicle seat.

5. The vehicle seat according to any one of claims 1 to 4, characterized in that: The movable part is a seat body, and the seat body is configured to move in the up-down direction of the vehicle seat in accordance with the rotation direction of the electric motor. The control unit is configured to be capable of executing the reverse control at least when the seat body moves downward of the vehicle seat.

6. The vehicle seat according to any one of claims 1 to 5, characterized in that: The control unit is configured to detect that the movable unit is in the movement blocked state based on the fact that the movable unit maintains the movement blocked state for a preset detection time.

7. The vehicle seat according to any one of claims 1 to 6, characterized in that: The vehicle seat further includes a rotation sensor configured to output a pulse signal in association with the rotation of the electric motor. While the operation switch is outputting the on signal, the movable portion in a state in which its movement is blocked causes the rotation sensor to not output the pulse signal.

8. The vehicle seat according to any one of claims 1 to 7, characterized in that: While the operation switch is outputting the on signal, the energizing current flowing to the electric motor continues to increase through the movable portion in a state in which the movement thereof is blocked.

9. The vehicle seat according to any one of claims 1 to 8, characterized in that: The control unit is configured as follows: In response to (i) the operation switch outputting the on signal and (ii) the control unit not detecting that the movable unit is in a state where movement is blocked, outputting a supply voltage having a first magnitude to the electric motor, In response to the control portion detecting that the movable portion is in a state in which its movement is blocked, before executing the reverse rotation control, executing a motor load reduction control, The motor load reduction control is configured such that the control unit outputs the power supply voltage having a second magnitude smaller than the first magnitude to the electric motor.

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