JP2019202651A - Vehicle seat - Google Patents

Abstract

To provide a vehicle seat that is able to prevent erroneous operation while determining at an earlier stage that the inflation of an air bag has completed.SOLUTION: In one aspect of the present disclosure, a vehicle seat comprises: a seat body having a support surface supporting a seated person; an at least one air bag disposed in the seat body and that inflates and shrinks by supply and discharge of air; an air supply system that supplies air to at least one air bag; and a control unit that alters a shape of the support surface by controlling the air supply system. The control unit stops supply of air to at least one air bag by the air supply system when a time differential value of a surface pressure of the at least one air bag has become equal to or larger than a predetermined lower limit.SELECTED DRAWING: Figure 4

Description

  The present disclosure relates to a vehicle seat.

  A vehicle seat that can automatically adjust the shape of a support surface such as a seat back according to the body shape and posture of a seated person is known (see Patent Document 1). In this vehicle seat, the shape of the support surface is changed by the expansion of the plurality of air bags.

JP 2014-1118030 A

  When adjusting the shape of the support surface using multiple air bags, the surface pressure of the air bag is detected by a surface pressure sensor, and the air pressure to the air bag is increased when the surface pressure exceeds a predetermined lower limit. Control for stopping the supply is generally performed.

  However, in the inflating air bag, the surface pressure increases rapidly in the latter half of the expansion, so if the lower limit value of the surface pressure is set to a value included in the rapid expansion stage, this may depend on the detection timing of the surface pressure. The supply of air is stopped after greatly exceeding the lower limit. In addition, when noise is applied to the output of the surface pressure sensor, there is a possibility that the supply of air stops with insufficient surface pressure.

  One aspect of the present disclosure aims to provide a vehicle seat that can suppress malfunctions while early determining completion of inflation of an air bag.

  One aspect of the present disclosure includes a seat body (2) having a support surface (23) for supporting a seated person, and at least one that is disposed on the seat body (2) and expands and contracts by air supply and discharge. An air bag (3), an air supply system (4) that supplies air to at least one air bag (3), and a control unit that changes the shape of the support surface (23) by controlling the air supply system (4). (5) is a vehicle seat (1).

  Further, the control unit (5), when the time differential value of the surface pressure in the at least one air bag (3) becomes equal to or higher than a predetermined lower limit value, at least one air bag (4) by the air supply system (4). Stop supplying air to 3).

  According to such a configuration, by using the time differential value of the surface pressure that rises earlier than the surface pressure when the air bag (3) is inflated and linearly increases even in the latter half of the inflation, the supply of air is performed. The stop timing can be advanced (that is, the lower limit value for stopping the supply can be reduced). Further, malfunction of the control unit (5) due to noise can be suppressed.

  In one aspect of the present disclosure, the lower limit value is greater than the time differential value of the surface pressure at the point where the slope of the time differential value of the surface pressure in the at least one air bag (3) changes, and at least one air bag. It may be smaller than the time differential value at the point where the surface pressure reaches the maximum value when (3) is continuously expanded. According to such a configuration, it is possible to easily set the lower limit value of the time differential value suitable for performing the end determination of the air supply to the air bag (3).

  Note that the reference numerals in the parentheses above are examples showing the correspondence with the specific configurations described in the embodiments described later, and the present disclosure is limited to the specific configurations shown in the reference numerals in the parentheses. It is not something.

FIG. 1 is a schematic perspective view showing a vehicle seat in the embodiment. 2A is a schematic front view showing a surface pressure detection area and a support area of a plurality of blocks in the seat back of the vehicle seat of FIG. 1, and FIG. 2B is a view of the seat cushion of the vehicle seat of FIG. It is a typical top view which shows the surface pressure detection area and support area of a some block. FIG. 3 is a configuration diagram illustrating an air supply system and a control unit of the vehicle seat of FIG. 1. FIG. 4A is a graph schematically showing the temporal change of the surface pressure in the air bag, and FIG. 4B is a graph schematically showing the temporal change of the time differential value of the surface pressure in the air bag. FIG. 5 is a flowchart schematically showing processing executed by the control unit shown in FIG.

Hereinafter, embodiments to which the present disclosure is applied will be described with reference to the drawings.
[1. First Embodiment]
[1-1. Constitution]
A vehicle seat 1 shown in FIG. 1 includes a seat body 2, a plurality of air bags 3, an air supply system 4 (see FIG. 3), and a control unit 5 (see FIG. 3).

  The vehicle seat 1 of this embodiment is used as a seat for a passenger car. In addition, the direction in the following description and each figure means the direction in the state which assembled | attached the vehicle seat 1 to the vehicle (namely, passenger car). In the present embodiment, the seat width direction matches the left-right direction of the vehicle, and the front of the seat matches the front of the vehicle.

<Sheet body>
As shown in FIG. 1, the seat body 2 includes a seat cushion 21 and a seat back 22. The seat cushion 21 is a part for supporting a seated person's buttocks and the like. The seat back 22 is a part for supporting the back of the seated person, and can swing in the front-rear direction of the seat with respect to the seat cushion 21.

  The seat body 2 has a support surface 23 that supports a seated person. The support surface 23 includes an upper surface of the seat cushion 21 and a front surface of the seat back 22. That is, the support surface 23 is provided across the seat cushion 21 and the seat back 22. The support surface 23 is configured to change its shape by a plurality of air bags 3 described later.

<Air bag>
The plurality of air bags 3 are disposed inside the seat cushion 21 and the seat back 22.

  The plurality of air bags 3 are so-called air bladders that can be expanded and contracted by supplying and discharging air. The plurality of air bags 3 change the shape of the support surface 23 according to the posture of the seated person by expansion or contraction.

  The plurality of air bags 3 include a plurality of blocks 31A-31H including one or a plurality of air bags 3 (that is, a first block 31A, a second block 31B, a third block 31C, a fourth block 31D, a fifth block 31E, 6th block 31F, 7th block 31G, and 8th block 31H).

  The first block 31A includes one air bag 3 arranged on the right shoulder. The second block 31B includes one air bag 3 disposed on the left shoulder. The third block 31C includes three air bags 3 arranged vertically on the lumbar (that is, a portion where the spine hits), and two air bags 3 arranged side by side on the pelvis of the seat back 22. Including.

  The fourth block 31D includes one air bag 3 arranged on the right side of the seat back 22. The fifth block 31E includes one air bag 3 arranged on the left side of the seat back 22.

  The sixth block 31F includes two air bags 3 arranged side by side on the pelvis of the seat cushion 21. The seventh block 31G includes one air bag 3 arranged on the right side of the seat cushion 21. The eighth block 31H includes one air bag 3 arranged on the left side of the seat cushion 21.

  The plurality of air bags 3 included in the third block 31C are supplied and contracted simultaneously (that is, in synchronization). Similarly, air supply and contraction are simultaneously performed in the plurality of air bags 3 included in the sixth block 31F.

  Each block is provided with at least one surface pressure sensor for measuring the surface pressure of one or more air bags 3 included in each block. In each block, a plurality of surface pressure sensors may be attached to one air bag 3. In a block including a plurality of air bags 3, a surface pressure sensor may be attached to only one air bag 3.

  As shown in FIGS. 2A and 2B, the detection area 33 of the surface pressure sensor in each block is preferably larger than the support area 32 in each block and includes the support area 32.

  The support area 32 is an area that comes into contact with a seated person in each block (that is, a load on the seated person is applied). Some blocks (for example, the third block 31C) have a plurality of support areas 32.

<Air supply system>
The air supply system 4 supplies air to the plurality of air bags 3. As shown in FIG. 3, the air supply system 4 includes one air pump 41, an air supply line 42, a first supply valve 43A, a second supply valve 43B, a third supply valve 43C, a fourth supply valve 43D, It has the 5th supply valve 43E, the 6th supply valve 43F, the 7th supply valve 43G, and the 8th supply valve 43H.

  The air pump 41 is an electric pump that discharges air to be supplied to the plurality of air bags 3. The air pump 41 is disposed inside the seat body 2. The air discharged from the air pump 41 is also supplied to other devices (not shown) that adjust the posture of the seat body 2.

  The air supply line 42 connects the discharge port of the air pump 41 and the plurality of air bags 3. A plurality of blocks 31A-31H are connected to the air supply line 42 in parallel. In the block including the plurality of air bags 3, the plurality of air bags 3 in the block are connected in parallel or in series.

  The plurality of supply valves 43A-43H are on-off valves that are provided one for each of the blocks 31A-31H and switch the supply of air to the plurality of blocks 31A-31H. The plurality of supply valves 43A-43H are respectively provided in branch paths to the plurality of blocks 31A-31H of the air supply line 42. As the plurality of supply valves 43A-43H, for example, electromagnetic valves are used.

  For example, air can be supplied to the air bladder 3 included in the first block 31A when the first supply valve 43A is open, and no air is supplied to the first block 31A when the first supply valve 43A is closed.

<Control unit>
The control unit 5 performs a shape changing process for the support surface 23 of the seat body 2 under the control of the air supply system 4.

  Specifically, the control unit 5 expands the plurality of blocks 31A-31H one by one or a plurality at the same time by operating or stopping the air pump 41 and operating the plurality of supply valves 43A-43H, thereby supporting the support surface 23. To the desired shape.

  The control unit 5 is configured by a microcomputer including, for example, a microprocessor, a storage medium such as a RAM and a ROM, and an input / output unit. The controller 5 controls the air pump 41, the plurality of supply valves 43A-43H, and the like by executing a program stored in advance. The control unit 5 may be incorporated in a control device such as an engine control unit (ECU, not shown) mounted on the vehicle.

  In the shape change process of the support surface 23, the control unit 5 selects one or a plurality of blocks from the plurality of blocks 31A-31H, and selects them by operating the air pump 41 and switching the plurality of supply valves 43A-43H. Expansion processing is performed to supply air to the one or more blocks.

  As shown in FIG. 4B, the control unit 5 determines the surface pressure in the selected one or more blocks (that is, the representative value of the surface pressure of the one or more air bags 3 included in the selected one or more blocks). The air is supplied to each air bag 3 until the time differential value is within a predetermined range (that is, the lower limit value S11 or more).

  The control unit 5 stops the supply of air to each air bag 3 by the air supply system 4 at the time T10 when it is first detected that the time differential value of the surface pressure of each air bag 3 becomes the lower limit value S11 or more. . The time differential value is calculated, for example, from the difference in surface pressure at each time detected at 100 msec intervals.

  The time differential value of the surface pressure shown in FIG. 4B increases linearly even in the latter half of the inflation, with the rising timing when the air bladder 3 is inflated being earlier than the surface pressure shown in FIG. 4A. Therefore, by using the time differential value as a determination index, the timing of stopping the supply of air can be advanced (that is, the lower limit value for stopping the supply can be reduced). As a result, it is possible to shorten the time required to shift to the next block expansion process.

  Moreover, noise included in the output of the surface pressure sensor can be reduced by differentiating the surface pressure with time. Therefore, the malfunction of the control part 5 can be suppressed by using a time differential value for determination.

  4A and 4B, the graphs indicated by the dotted lines show the surface pressure and the time differential value when the supply of air is not stopped (that is, when the expansion is continued) even if the time differential value becomes the lower limit value S11 or more. It is time change.

  As shown in FIG. 4B, the lower limit value S11 of the time differential value in the expansion process is the surface pressure at the time T11 when the slope of the time differential value of the surface pressure changes (that is, when the expansion rate per unit time increases rapidly). Is set to a value smaller than the time differential value Q2 at time T12 when the surface pressure reaches the maximum value when the block is continuously expanded.

After finishing the expansion process of one or a plurality of blocks, the control unit 5 selects one or a plurality of different blocks and repeats the expansion process.
Note that the lower limit value S11 of the time differential value in the expansion process may be set to a different value for each block or each air bag.

[1-2. processing]
Hereinafter, the shape changing process of the support surface 23 executed by the control unit 5 will be described with reference to the flowchart of FIG.

  In this process, the control unit 5 first selects one or a plurality of blocks from the plurality of blocks 31A-31H (step S110). After selecting the block, the control unit 5 supplies air to the selected block (step S120). Subsequently, the control unit 5 determines whether or not the time differential value of the surface pressure of the air bladder 3 is equal to or greater than a predetermined lower limit value in each of the currently selected blocks (step S130).

  When the time differential value of the surface pressure of the air bladder 3 in the selected block is less than the lower limit value (S130: NO), the control unit 5 returns to step S120 and continues to supply air to the currently selected block. .

  When the time differential value of the surface pressure of the air bladder 3 in the selected block is equal to or greater than the lower limit value (S130: YES), the control unit 5 ends the inflating process in the selected block, and all the plurality of blocks In 31A-31H, it is determined whether or not the expansion process is completed (step S140).

  When the expansion process of all the blocks 31A-31H is completed (S140: YES), the control unit 5 ends this process. Thereby, the shape change of the support surface 23 by the expansion | swelling of the air bag 3 is completed.

  When the expansion process of all the blocks 31A-31H is not completed (S140: NO), the control unit 5 returns to step S110, selects one or more different blocks, and repeats the expansion process up to step S130.

[1-3. effect]
According to the embodiment detailed above, the following effects can be obtained.
(1a) By using the time differential value of the surface pressure as an index, the timing of stopping the supply of air can be advanced (that is, the lower limit value for stopping the supply can be reduced). Further, malfunction of the control unit 5 due to noise can be suppressed.

  (1b) The lower limit value of the time differential value is larger than the time differential value Q1 of the surface pressure at the time point T11 when the slope of the time differential value of the surface pressure changes, and the surface pressure is maximum when the block is continuously expanded. By making it smaller than the time differential value Q2 at the time point T12 when the value is reached, it is possible to easily set a lower limit value suitable for determining the end of the air supply to the air bag 3.

[2. Other Embodiments]
As mentioned above, although embodiment of this indication was described, it cannot be overemphasized that this indication can take various forms, without being limited to the above-mentioned embodiment.

  (2a) The number and position of the plurality of air bags 3 and the number and position of the plurality of blocks in the vehicle seat 1 of the above embodiment are examples, and can be arbitrarily changed. The plurality of air bags 3 may be disposed only on the seat cushion 21 or only on the seat back 22.

  (2b) In the vehicle seat 1 of the above-described embodiment, the control unit 5 may perform the expansion process twice or more on each of the blocks 31A-31H. For example, the control unit 5 may repeat the expansion process until the surface pressure of all the blocks 31A-31H becomes a certain value or more.

  (2c) The vehicle seat 1 of the above-described embodiment can be applied to a sheet used for a vehicle other than a passenger car, and a seat used for a vehicle other than a vehicle such as a railway vehicle, a ship, and an aircraft.

  (2d) The functions of one component in the above embodiment may be distributed as a plurality of components, or the functions of a plurality of components may be integrated into one component. Moreover, you may abbreviate | omit a part of structure of the said embodiment. In addition, at least a part of the configuration of the above embodiment may be added to or replaced with the configuration of the other embodiment. In addition, all the aspects included in the technical idea specified from the wording described in the claims are embodiments of the present disclosure.

DESCRIPTION OF SYMBOLS 1 ... Vehicle seat, 2 ... Seat main body, 3 ... Air bag, 4 ... Air supply system, 5 ... Control part,
21 ... Seat cushion, 22 ... Seat back, 23 ... Support surface,
31A-31H ... Block, 32 ... Support area, 33 ... Detection area,
41 ... Air pump, 42 ... Air supply line, 43A-43H ... Supply valve.

Claims (2)

A seat body having a support surface for supporting a seated person;
At least one air bag disposed on the seat body and inflated and deflated by air supply and discharge;
An air supply system for supplying air to the at least one air bag;
A control unit that changes the shape of the support surface by controlling the air supply system;
A vehicle seat comprising:
The control unit stops the supply of air to the at least one air bag by the air supply system when the time differential value of the surface pressure in the at least one air bag becomes equal to or higher than a predetermined lower limit value. , Vehicle seats. The vehicle seat according to claim 1,
The lower limit value is larger than the time differential value of the surface pressure at a point where the slope of the time differential value of the surface pressure in the at least one air bag changes, and the at least one air bag is kept inflated. The vehicle seat is smaller than the time differential value at the point where the surface pressure reaches the maximum value.

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