JP4129336B2 - Seat weight measuring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for measuring a seat weight including the weight of an occupant sitting on a vehicle seat. In particular, the present invention relates to a seat weight measuring device that has been improved so that the performance of the load sensor is not impaired by dimensional errors or deformation of the vehicle body or the seat.
[0002]
[Background]
Automobiles are equipped with seat belts and airbags as equipment for ensuring the safety of passengers. Recently, in order to further improve the performance of seat belts and airbags, there is a trend to control the operation of these safety equipment according to the weight (weight) of the occupant. For example, the deployment gas amount and deployment speed of the airbag are adjusted according to the weight of the occupant, and the pretension of the seat belt is adjusted. For that purpose, it is necessary to know the weight of the passenger sitting on the seat by some means. As an example of such means, load sensors (load cells) are arranged at the four front, rear, left and right corners under the seat, and the weight of the seat including the weight of the occupant is measured by summing the vertical loads applied to the load cell. (Japanese Patent Application No. 9-156666, Japanese Patent Application No. 10-121627, etc. by the same applicant).
[0003]
[Problems to be solved by the invention]
By the way, in order to perform accurate measurement with this seat weight measuring device, it is necessary to eliminate as much as possible that a load other than the weight of the seat and the occupant (or object) on the seat is applied to the sensor. As one of such loads to be excluded, there is a load (referred to as an assembly load in the present specification) that is generated when the seat weight measuring device is forcibly attached in spite of dimensional errors and deformations in the vehicle body and the seat. is there.
[0004]
The present invention has been made in view of such problems, and an object of the present invention is to provide a seat weight measuring device in which the performance of the load sensor is not impaired by the dimensional error or deformation of the vehicle body or the seat.
[0005]
Means for Solving the Problem and Embodiment of the Invention
  In order to solve the above problems, the present inventionBaseA seat weight measuring device is a device for measuring a seat weight including the weight of an occupant sitting on a vehicle seat; and at least a part of the seat weight inserted in the seat or between the seat and the vehicle body is electrically A load sensor that converts the signal into a signal; and a mechanism for absorbing displacement and / or deflection between the seat and the vehicle body.
[0006]
In order to prevent assembly load caused by component manufacturing error, dimensional deviation at the time of installation, deflection, etc. from being transmitted to the load sensor, the above-mentioned absorption mechanism is provided in the connection holding part between the load sensor and the seat or the load sensor and the body, so Absorbs dimensional errors. As a result, a purer measurement load (seat weight) is applied to the load sensor, and accurate measurement using a sufficiently wide effective range of the sensor becomes possible. Further, it is possible to prevent a load exceeding the allowable range of the load sensor from being applied to the sensor.
[0007]
The purpose of the seat weight measuring device referred to in this specification is basically to measure the weight of an occupant on the seat. Therefore, a device that cancels the weight of the seat itself and measures only the weight of the occupant is also included in the seat weight measuring device referred to in this specification.
[0008]
In the present invention, it is preferable that the absorption mechanism is movable even after the seat weight measuring device is attached to the vehicle body and the seat.
Even when an unexpected load is applied to the seat after the load sensor is assembled in the vehicle and the seat is bent or when the vehicle body is bent during travel, the deflection can be absorbed by the connecting portion so that the deflection is not transmitted to the load sensor.
[0009]
In the seat weight measuring device of the present invention, it is preferable that the absorption mechanism includes a slide mechanism and a rotation mechanism.
Absorbs misalignment in position / size and rotation direction.
[0010]
The seat weight measuring device of the present invention preferably further includes a centering mechanism that regulates the position of the absorption mechanism.
[0011]
This centering mechanism is formed of a relatively weak spring, for example, and works to position the slide mechanism and the rotation mechanism as close as possible to the center of the slidable range or rotation angle. By the action of the centering mechanism, the slidable dimensions of the slide mechanism and the rotation mechanism can be secured in both directions (left and right, up and down, front and rear) after the seat weight measuring device is attached.
[0012]
Hereinafter, it demonstrates, referring drawings. First, the structure around the seat of an automobile will be described with reference to FIG.
FIG. 6A is a front cross-sectional view schematically showing a structural example of a portion for attaching the seat to the vehicle body. FIG. 6B is a side view. In addition, the arrow in a figure shows the following directions. Upper: Gravity direction upward when the vehicle is horizontal, Lower: Same downward direction, Front: Vehicle forward direction, Rear: Vehicle backward direction, Left: Left toward vehicle forward direction, Right: Same right.
[0013]
FIG. 6 shows the sheet 3. A person 1 sits on the seat cushion 3 a of the seat 3. The lower surface of the seat cushion 3a is supported by a seat frame 5 made of steel plate. The seat frame 5 includes parts such as a bottom plate 5a, a horizontal plate 5c, a vertical plate 5e, and a slide plate 5g. The bottom plate 5a extends so as to cover the lower surface of the seat cushion 3a. The horizontal plate 5c extends along the left and right sides of the bottom surface of the bottom plate 5a. The vertical plate 5e is suspended from the center of the lower surface of the horizontal plate 5c. The slide plate 5g protrudes like a blade to the left and right of the vertical plate 5e, and the tip is bent upward.
[0014]
Two seat rails 7 are provided in parallel below the left and right sides of the seat 3 so as to extend in the front-rear direction. The cross section of the seat rail 7 is U-shaped and has a recess 7c inside. The mouth above the recess 7c is a groove 7a extending in the front-rear direction. A vertical plate 5e of the seat frame 5 is contained in the groove 7a.
A slide plate 5 g of the seat frame 7 is contained in the recess 7 c of the seat rail 7. The slide plate 5g is slidable in the front-rear direction within the seat rail 7.
[0015]
A seat weight measuring device 9 is connected to the lower surface of the seat rail 7. The seat weight measuring device 9 has an elongated box-like outer shape extending in the front-rear direction. Details of the seat weight measuring device 9 will be described later.
Seat brackets 11 are attached to the front and rear end portions of the lower surface of the seat weight measuring device 9. The seat bracket 11 is fixed to a seat mounting portion 13 of the vehicle body with bolts or the like.
[0016]
FIG. 2 is a diagram showing an overall configuration of a seat weight measuring apparatus according to one embodiment of the present invention. (A) is a plan view, (B) is a side sectional view, and (C) and (D) are front sectional views. In addition, in FIG. 2 (A) and (B), the back half part is abbreviate | omitting illustration.
FIG. 3 is a partially broken perspective view showing a detailed configuration around the sensor plate.
FIG. 4 is a plan view showing a detailed configuration of the sensor plate.
FIG. 5 is a diagram showing the relationship between the sensor plate and the half arm. (A) is a plan view, (B) is a side view in an unloaded state, and (C) is a side view schematically showing a state in which a load is applied.
[0017]
The seat weight measuring device 9 is configured with an elongated base 21 as a base. When the base 21 is attached to the vehicle body, the base 21 extends in the front-rear direction, and as shown in FIGS. 2C and 2D, the base 21 is a steel plate pressed product having a U-shaped front section. The bottom portion of the cross section of the base 21 is called a bottom plate 21c, and the portion that bends 90 ° from the left and right ends of the bottom plate 21c and rises upward is called a side plate 21a.
[0018]
The base side plate 21a has two pin holes 21e and 21g in the front and rear. The holes 21e and 21g are opened to face the left and right side plates 21a and 21a '.
The end-side hole 21e is opened from a front and rear end of the base 21 to a site that is about 1/8 of the entire length of the base 21. The hole 21e is a long hole extending vertically as shown in FIG. The end of the bracket pin 27 is inserted in the long hole 21e.
[0019]
However, there are gaps on the top, bottom, left and right of the bracket pin 27 and the long hole 21e, and the bracket pin 27 does not normally touch the inner edge of the long hole 21e. However, when an excessive load is applied to the seat weight measuring device 9 (specifically, the pin bracket 25 portion), the bracket pin 27 is lowered and hits the lower edge of the long hole 21e, and the excess load is detected by a load sensor (sensor plate). 51, detailed later). That is, the pin 27 and the long hole 21 e constitute a part of a mechanism that limits the upper limit of the load applied to the sensor plate 51. The main role of the bracket pin 27 is to transmit the seat weight applied to the pin bracket 25 to the Z arm 23.
[0020]
A pin hole 21g is formed slightly near the center of the long hole 21e (about 1/10 of the entire length of the base 21). A base pin 31 passes through the hole 21g. The base pin 31 exists so as to span between the left and right base side plates 21a and 21a '. Retainers 33 are attached to the left and right ends of the pin 31, and the base pin 31 is fixed to the base 21. The base pin 31 is a rotation center axis of the Z arm 23.
[0021]
The Z arm 23 is disposed inside the base 21. As for the planar shape of the Z arm 23, the center side is divided into left and right bifurcated (fork 23h), and the front and rear ends are rectangular. At the left and right ends of the half of the Z arm 23 near the front and rear ends, side plates 23a folded upward by 90 ° are formed. The fork 23h is simply a flat plate. The side plate 23 a extends along the inside of the side plate 21 a of the base 21. However, there is a gap between the side surfaces 23a and 21a.
[0022]
The Z arm side plate 23a is also provided with two pin holes 23c and 23e. A bracket pin 27 passes through the pin hole 23c near the front and rear ends. The pin hole 23c and the bracket pin 27 hardly slide. A base pin 31 passes through the pin hole 23e closer to the center. The base pin 31 is the center of rotation of the Z arm 23, and there is sliding between the pin hole 23 e and the base pin 31 by the amount of rotation of the Z arm 23. A perforated disc-like spacer 35 is fitted between the base side plate 21a and the Z arm side plate 23a on the outer periphery of the base pin 31.
[0023]
The fork portion 23h of the Z arm 23 is approximately half the total length of the Z arm 23. The part 23h is divided into right and left and extends toward the center in the front-rear direction, and is narrower toward the center. The action part 23j at the tip of the Z arm fork 23h is sandwiched between the blade parts 41a and 42a of the upper and lower half arms 41 and 42 as shown in FIGS.
When a load is applied to the pin bracket 25, the Z arm 23 rotates slightly (maximum of about 5 °), and the action portion 23j transmits the load to the sensor plate 51 via the half arms 41 and 42.
[0024]
As shown in FIG. 2C, the pin bracket 25 has a substantially U-shaped cross section. The length in the front-rear direction is not so long as almost 1/20 of the base 21. The upper surface 25a of the pin bracket 25 is flat, and the seat rail 7 shown in FIG. The two are firmly connected by bolt fastening or the like.
[0025]
The left and right side plates 25b of the pin bracket 25 hang down to the left and right of the bracket 25, and the lower ends thereof are bent toward the inside. The side plate 25b is arranged with play inside the Z arm side plate 23a. A pin hole 25c is opened in the side plate 25b. A bracket pin 27 passes through the hole 25c. The dimension of the pin hole 25 c is larger than the diameter of the bracket pin 27. The gap between the two absorbs dimensional errors and unexpected deformation of the seat and the vehicle body.
[0026]
A spring plate 29 is sandwiched between the left and right side plates 25b of the pin bracket 25 and the left and right Z arm side plates 23a. The spring plate 29 has a spring washer-like portion with a hole, and is fitted with a gap on the outside of the bracket pin 27. The spring plate 29 constitutes a centering mechanism that biases the pin bracket 25 in the center direction. Such a centering mechanism positions the pin bracket 25 as close to the center of the slidable range as possible. By the action of the centering mechanism, the movable range of the slide mechanism and the rotation mechanism can be secured in both directions (left and right, up and down, front and rear) after the seat weight measuring device is attached.
[0027]
Next, the configuration around the sensor plate 51 will be described.
First, the configuration of the sensor plate 51 itself will be described.
FIG. 4 is a diagram illustrating a configuration example of a sensor plate of the seat weight measuring apparatus according to one embodiment of the present invention. 4A is a plan view of the sensor plate, FIG. 4B is a side sectional view taken along line XX ′ in FIG. 4A, and FIG. 4C is a circuit diagram of the sensor.
[0028]
An insulating layer (lower insulating layer) 52 for electrical insulation is formed on a sensor plate (spring material) 51 which is a base material of the sensor 50. A wiring layer 53 is selectively formed on the insulating layer 52. Further, a resistance layer 54 is selectively formed on the wiring layer 53 to constitute a strain gauge. Then, an insulating layer (upper insulating layer) 55 is formed as a protective film thereof. As described above, since electric circuits such as resistors are directly laminated on the spring material 51, the processing cost and the assembling cost can be reduced, and the heat resistance and the corrosion resistance can be improved.
[0029]
The sensor plate 51 is a rectangular plate with two constrictions as a whole. A central shaft hole 51 a is formed at the center of the sensor plate 51. Bolt holes 51 b are formed at both ends of the sensor plate 51. A sensor 50 is formed from the periphery of the central shaft hole 51a to between the central shaft hole 51a and both bolt holes 51b. In a region 51c between the central shaft hole 51a and both bolt holes 51b in the region where the load sensor 50 is formed, constrictions are provided in a V shape on both sides. Since the portion where the sensor plate 51 is deformed is fixed by this constriction, the position change of the surface strain of the sensor 50 is also fixed, and the sensitivity becomes stable.
[0030]
The sensor 50 is disposed substantially symmetrically with respect to the center of the central shaft hole 51a. The four strain resistances constituting the sensor 50 are two strain resistances 54a and 54b on the tensile strain side closer to the bolt hole 51b (closer to the end), and closer to the central shaft hole 51a (closer to the center), Two strain resistors 54c and 54d on the compression strain side are arranged. The four strain resistors 54a, 54b, 54c, 54d are connected by wirings 53a, 53b, 53c, 53d so as to form a bridge circuit as shown in FIG. In addition, the thing in which the number of 1, 2, 3, 4 is entered in the square in a figure shows a terminal.
[0031]
A sensitivity adjustment resistor 54e is disposed between the strain resistors 54a and 54c and the strain resistors 54b and 54d.
Instead of detecting the strain of the sensor plate 51 by the strain resistors 54a, 54b, 54c, 54d, the deflection of the sensor plate 51 is detected by a capacitance sensor, a Hall element, etc., and the deflection is converted into a load. Good.
[0032]
As shown in FIGS. 3 and 5, the sensor plate 51 is firmly fixed on the column 63 by a washer 67 and a nut 68 at the center of the base bottom plate 21 c.
[0033]
As shown in FIGS. 3 and 5, the half arms 41 and 42 are parts of a front / rear / upper / lower four-piece set, and are assembled so as to sandwich the front / rear of the sensor plate 51 from above and below. Since the individual half arms 41 and 42 have the same shape, the upper half arm 41 will be described.
The half arm main body 41c is a rectangular plate, and a mounting hole 41e (FIG. 5B) is opened at the center thereof. A blade portion 41a extending in the left-right direction protrudes from the edge of the main body portion 41c near the center. A bank-shaped fulcrum 41b extending in the left-right direction is formed on the back surface of the blade portion 41a. The tip of the fulcrum 41b is a slightly sharp ridge.
[0034]
Next, an assembly structure of the upper and lower half arms 41 and 42, the sensor plate 51, and the Z arm operating portion 23j will be described.
The lower surface of the main body portion 41 c of the upper half arm 41 and the upper surface of the main body portion 42 c of the lower half arm 42 are flat surfaces and are fixed to the surface of the sensor plate 51 by being perfectly aligned. The blade portions 41a and 42a of the upper and lower half arms 41 and 42 face each other with the fulcrums 41b and 42b facing each other. An action portion 23j of the Z arm 23 is sandwiched between both fulcrums 41b and 42b. The fulcrum is positioned between the two strain gauges 54a, 54c or 54d, 54b (in the constricted portion 51c of the sensor plate 51).
[0035]
When a load is applied to the pin bracket 25 of the seat weight measuring device 9, the Z arm 23 is slightly rotated and the action portion 23j is lifted upward. FIG. 5C schematically shows the state of the sensor plate and the half arm at this time in an exaggerated manner.
When the Z arm action part 23j is lifted, the fulcrum 41b of the upper half arm 41 is lifted. For this reason, a moment M is applied to the longitudinal end of the sensor plate 51. By this moment M, the strain gauges 54a, 54b at the ends in the front-rear direction are pulled, and the strain gauges 54c, 54d at the center are compressed. The resistance change of each strain gauge is extracted as an electric signal, and the strain applied to the sensor plate and the load applied to the pin bracket 25 are measured.
[0036]
Next, all of the deviation / deflection absorbing mechanism of the seat weight measuring apparatus of the present embodiment will be described together.
FIG. 1 is a diagram illustrating a deviation / deflection absorbing mechanism of the seat weight measuring apparatus according to the present embodiment. (A) is an exploded perspective view, (B) is a front sectional view of the pin bracket portion. The pin bracket 25 is firmly fixed to the seat rail 7 with a bolt or the like. The configuration of each part of the seat weight measuring device 9 and the assembly relationship are as described above with reference to FIG.
With respect to the vertical direction of the vehicle body, the gap between the pin hole 25c of the pin bracket 25 and the bracket pin 27 is absorbed. The quantitative configuration will be described later.
In the longitudinal direction of the vehicle body, the pin hole 25c of the pin bracket 25 is used as a long hole to absorb the deviation.
In the left-right direction of the vehicle body, the gap is absorbed by the gap between the pin bracket side plate 25b and the Z arm side plate 23a. This portion is provided with a centering mechanism by a spring plate 29.
[0037]
For rotation about the vertical direction of the vehicle body, the gap is absorbed mainly by the gap between the pin bracket side plate 25b and the Z arm side plate 23a.
For rotation about the longitudinal direction of the vehicle body, the gap is absorbed by the gap between the pin bracket side plate 25b and the Z arm side plate 23a, as in the vertical direction of the vehicle body.
The rotation about the horizontal direction of the vehicle body is absorbed mainly by the rotation of the pin bracket 25 around the bracket pin 27.
[0038]
Next, a quantitative configuration of the absorption mechanism will be described.
The absorption mechanism of the seat weight measuring device of the present embodiment is described below with respect to the vertical direction of the vehicle body._UD[Mm] or more can slide.
L_UD= Β {(H₁+ H₂) / 4α + F}
β: Deflection amount per unit load in the vertical direction of the absorption mechanism [mm / kgf]
H₁: Vertical error of seat leg [mm]
H₂: Vertical dimension error [mm] of the seat fixing part on the vehicle body side
α: Deflection amount per unit load [mm / kgf] when three of the four legs on the front, rear, left and right of the seat are fixed and the remaining one is bent up and down
F: Minimum measurement range [kgf] of the weight measured at one leg of the seat.
[0039]
FIG. 7 is a view for explaining the concept when examining the slidable dimensions of the absorption mechanism in the vertical direction of the vehicle body.
FIG. 7A shows a dimensional error on the sheet side. When the seat leg is placed on the flat surface 10, the leg (bracket 11) at one of the front, rear, left and right is an error H.₁Only floated. Here, the seat means a combination of the seat frame (reference numeral 5 in FIG. 6) and the seat rail (reference numeral 7 in FIG. 6).
[0040]
FIG. 7B shows a dimensional error in the vertical direction of the seat mounting portion 13 of the vehicle body. This seat mounting portion also has an error H in the remaining one seat mounting portion, assuming that the plane 10 formed by three of the four seat mounting portions in the front, rear, left and right is the reference plane.₂Exists.
[0041]
In the state of FIG.₁H floating leg 11₂The assembly is performed by forcibly pressing the seat mounting portion 13 that has been sunk. At this time, the force F generated on the leg due to the deflection of the seat_A(Assembly load) is the following in the worst state where the other three attachment portions are considered not to be deformed.
F_A= (H₁+ H₂) / Α (1)
In addition, when there are absorption mechanisms at the four attachment portions, the force F generated at the legs is generated because the absorption of deflection is dispersed at the four locations._AIs as follows.
F_A= (H₁+ H₂) / 4α (1 ')
On the other hand, the slide dimension L in the vertical direction to be absorbed by the absorption mechanism_UDIs as follows from the center position in the vertical direction.
L_UD= Β (F_A+ F) (2)
The meaning of this formula is as follows. That is, F is the total value of loads that can be applied to the seat weight measuring device._A(Assembly load) and F_S(Sheet itself) and F_MThere is a possibility that the load sensor mechanism is deformed by a value obtained by multiplying the sum of F (the person or object on the seat) by F and β which is the amount of deflection per unit load in the vertical direction of the load sensor mechanism. The absorption mechanism may absorb this deformation allowance.
From the above equations (1 ′) and (2), the following is obtained.
L_UD= Β {(H₁+ H₂) / 4α + F} (3)
[0042]
An example of design values is shown below.
Dimensional tolerance (H₁+ H₂) = ± 5mm
4α = 0.25mm / kgf
F = 60kgf
β = 0.02mm / kgf
L_UD= 0.02 x 80kgf = 1.6mm
[0043]
Next, the absorption capability with respect to the left-right direction of the vehicle body will be described.
When a load is applied to the seat after the assembly of the seat weight measuring device into the vehicle body, a load due to the deflection of the seat or a load due to the deflection of the vehicle body during traveling occurs. The deflection is absorbed by the connecting portion so that this load is not transmitted to the load sensor. The width of the absorbed deflection is given by the following calculation formula.
[0044]
That is, the absorption mechanism of this embodiment is described below with respect to the left-right direction of the vehicle body._LRThe slide is possible.
L_LR= Ax + by + c-L_S
x: Dimensions from the center of the seat in the left-right direction to the center of the seat leg [mm]
a: Per unit load (in the load measurement range?) change rate of the above x, a = Δx / x
b: Normal value (sin θ) of the horizontal deviation angle θ of the center position of the lower surface of the seat leg relative to the center position of the seat leg per unit load (in the load measurement range?)
y: Seat leg height [mm]
c: Dimensional tolerance from the seat center to the seat leg center position [mm]
L_S: Deviation amount [mm] allowed by the load sensor.
[0045]
FIG. 8 is a view for explaining the concept of examining the slidable dimension of the absorption mechanism in the left-right direction of the vehicle body. (A) shows before the load is applied, and (B) shows after the load is applied.
FIG. 8 shows the seat 3, the seat frame 5, and the seat bracket 11. The seat frame 5 is shown as including a seat rail 7 as well.
[0046]
In FIG. 8A, the left and right seat leg center Z from the center in the left-right direction of the seat.₁The dimension up to is X.
The height of the seat bracket 11 is y.
In FIG. 8B, when a load is applied on the seat 3, x changes to x ', and the vertical center axis of the seat rail 11 is inclined by θ. For this reason, the center of the leg portion of the seat and the center of the seat bracket are x′−x = Δ^xIs shifted by the sum of ysinθ.
Here, Δx = ax and ysin θ = by can be expressed.
Furthermore, the original dimensional tolerance c must also be absorbed by the absorption mechanism. The amount of deviation L allowed by the load sensor from the sum total of No. 3_SThe left-right slide dimension L of the absorption mechanism whose dimension minus_LRIt becomes.
L_LR= Ax + by + c-L_S
[0047]
An example of design numerical values in the case of x = 250 mm and y = 20 mm is shown below.
a = 0.002 to 0.005
b = 0.01-0.07
c = 0.1-1mm
L_S= 1.3-2.5mm
L_LR= 1.3-2.0mm
[0048]
FIG. 9 is a side sectional view showing a configuration of a seat weight measuring apparatus according to another embodiment of the present invention.
The seat weight measuring device 100 of this example is attached between the seat rail 7 and the seat attachment portion 11 of the vehicle body or between the seat frame 5 and the seat rail 7. The seat weight measuring apparatus 100 includes a load cell 105, a hollow suspension 103, an XY slide 102, and the like.
[0049]
The load cell 105 incorporates a strain gauge and measures the seat weight. The load cell 105 is fixed to the seat attachment portion 11 by a fixing plate 107.
The hollow suspension 103 is a member that transmits a load to the load cell 105. The hollow suspension 103 is a hollow and relatively thin member. Therefore, the hollow suspension 103 can be elastically deformed up and down, front and rear, and right and left.
[0050]
The XY slide 102 is a disk-shaped member. The base 101 having the disc-shaped recess 101a is fitted to the recess 101a with a certain gap. Within the recess 101a, the XY slide 102 can slide back and forth and in the left-right direction (XY direction).
The hollow suspension 103 and the XY slide 102 form an absorption mechanism in the seat weight measuring apparatus 100.
[0051]
【The invention's effect】
As is apparent from the above description, according to the present invention, it is possible to provide a seat weight measuring device in which the performance of the load sensor is not impaired by the dimensional error or deformation of the vehicle body or the seat.
[Brief description of the drawings]
FIG. 1 is a view showing a deviation / deflection absorbing mechanism of a seat weight measuring apparatus according to the present embodiment. (A) is an exploded perspective view, (B) is a front sectional view of the pin bracket portion.
FIG. 2 is a diagram showing an overall configuration of a seat weight measuring apparatus according to one embodiment of the present invention. (A) is a plan view, (B) is a side sectional view, and (C) and (D) are front sectional views.
FIG. 3 is a partially broken perspective view showing a detailed configuration around a sensor plate.
FIG. 4 is a plan view showing a detailed configuration of a sensor plate.
FIG. 5 is a diagram showing a relationship between a sensor plate and a half arm. (A) is a plan view, (B) is a side view in an unloaded state, and (C) is a side view schematically showing a state in which a load is applied.
FIG. 6A is a front cross-sectional view schematically showing a structural example of a portion for attaching a seat to a vehicle body. FIG. 6B is a side view.
FIG. 7 is a view for explaining the concept when examining the slidable dimensions of the absorption mechanism in the vertical direction of the vehicle body.
FIG. 8 is a diagram for explaining a concept of examining a slidable dimension of the absorption mechanism in the left-right direction of the vehicle body. (A) shows before the load is applied, and (B) shows after the load is applied.
FIG. 9 is a side sectional view showing a configuration of a seat weight measuring apparatus according to another embodiment of the present invention.
[Explanation of symbols]
3 seats per person
3a Seat cushion 5 Seat frame
5a Bottom plate 5c Horizontal plate
5e Vertical plate 5g Slide plate
7 Seat rail 7a Groove
7c Concave part 9 Sheet weight measuring device
11 Seat bracket 13 Car body (seat mounting part)
21 Base 21a Side plate
21c Bottom plate 21e Long hole (pin hole)
21g Pin hole 23 Z-arm
23a Side plate 23c Pin hole
23e Pin hole 23f Bottom plate
23h Fork 23j Action part
25 pin bracket 25a top view
25b Side plate 25c Hole
27 Bracket pin 29 Spring plate
31 Base pin 33 Retainer
41 Upper half arm 41a Blade
41b fulcrum 41c body
42 Lower half arm 43 Screw
50 Sensor part 51 Sensor plate
54 Strain gauge 63 Column
68 Nut 69 Screw

Claims (2)

A device for measuring the weight of a seat including the weight of an occupant sitting in a vehicle seat;
A load sensor that is inserted in the seat or between the seat and the vehicle body and converts at least a part of the seat weight into an electrical signal;
A mechanism for absorbing displacement and / or deflection between the seat and the vehicle body;
Equipped with,
A seat weight measuring device , wherein the absorption mechanism is slidable by L _UD [ mm ] or more in the vertical direction of the vehicle body :
L _UD = β {(H ₁ + H ₂ ) / 4α + F}
β: Deflection amount per unit load in the vertical direction of the absorption mechanism [ mm / kgf ]
H ₁ : Vertical dimension error of the seat leg [ mm ]
H ₂ : Vertical dimension error [ mm ] of the seat fixing part on the vehicle body side
α: Deflection amount per unit load [ mm / kgf ] when three of the four legs on the front, rear, left and right of the seat are fixed and the remaining one is bent up and down
F: Minimum measurement range [ kgf ] of weight measured at one leg of the seat . A device for measuring the weight of a seat including the weight of an occupant sitting in a vehicle seat;
A load sensor that is inserted in the seat or between the seat and the vehicle body and converts at least a part of the seat weight into an electrical signal;
A mechanism for absorbing displacement and / or deflection between the seat and the vehicle body;
Comprising
A seat weight measuring device characterized in that the absorption mechanism is slidable by _LLR or more in the left-right direction of the vehicle body:
L _LR = ax + by + c−L _S
x: Dimension from the center of the left-right seat to the center of the seat leg [mm]
a: rate of change of x in the load measurement range, a = Δx / x
b: Normal value (sin θ) of the horizontal deviation angle θ of the center position of the lower surface of the seat leg relative to the center position of the seat leg in the load measurement range
y: Seat leg height [mm]
c: Dimensional tolerance from the seat center to the seat leg center position [mm]
L _S : Deviation amount allowed by the load sensor [mm].

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