JP2002310779A - Weight measuring instrument and sheet weight measuring instrument using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a weight measuring instrument that can improve the detection resolution of a load detecting sensor by reducing the load imposed upon the sensor as much as possible, and to provide a sheet weight measuring instrument using the instrument. SOLUTION: The weight measuring instrument is provided with a base 1, the load detecting sensor 2 mounted on the base 1, and a fixing pin 11 which is provided integrally with or separately from the base 1 and works as a supporting section. The instrument is also provided with a leaf spring 13 which is suspended between the recessed section 9b of the fixing pin 11 that works as a working point, and the recessed section 11b of the pin 11 that works as a supporting point and is supported from the upside and downside, so that the spring 13 may not move upward nor downward at the working point and supporting point; and an arm 15 which is connected to the central part of the spring 13 or its vicinity, receives the load of an object to be measured, and works as a mobile body which can move upward and downward.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weight measuring device for measuring the weight of an object and a seat weight measuring device using the same.

[0002]

2. Description of the Related Art Recently, a weight measuring device, for example, a seat weight measuring device using a weight measuring device has recently been developed.
In order to further improve the performance of seat belts and airbags, there is a trend to control the operation of the safety equipment according to the weight (weight) and physique of the occupant. For example, if a child rides and an adult rides,
Adjust the deployment gas amount and deployment speed of the airbag, or stop the operation of the airbag. For that purpose, it is necessary to know the weight of the occupant sitting in the seat by some means. As an example of such a means, it has been proposed to arrange load detection sensors (load cells) at four corners of a seat rail and measure the seat weight including the weight of the occupant by summing the vertical loads applied to the load cells. (Japanese Patent Application Laid-Open No. 11-1153).

As the load detecting sensor for the seat weight measuring device as described above, a small sensor having a maximum measuring load of about 50 kg is desired. Such load detection sensors include those in which a strain gauge is pasted (or formed) on a sensor plate that bends under load, a piezoelectric type, and displacement of an elastic member that bends under load is detected by a capacitance sensor. There are things to do.

[0004]

In such a weight measuring device and a seat weight measuring device using the same, the load of the object to be measured is applied as it is to a load detecting sensor constituting the device, so that the strength assurance is given priority. Then, there is a problem that the detection resolution is necessarily reduced.

[0005] The present invention is to solve this problem,
An object of the present invention is to provide a weight measuring device capable of improving the detection resolution by reducing the load applied to the load detecting sensor as much as possible and a seat weight measuring device using the same.

[0006]

According to the present invention, there is provided a weight measuring apparatus comprising: a base fixed to an object to be mounted; a load detecting sensor mounted on the base; A support portion provided separately, suspended by an application point of the load detection sensor and a support point on the support portion, and from the vertical direction so as to be substantially immovable in the vertical direction at the application point and the support point. A supported leaf spring,
A movable body is connected near the center of the leaf spring, receives a load of the object to be measured, and is movable in the vertical direction. With this configuration, it is possible to obtain a weight measuring device in which the load on the load detection sensor is reduced and the detection resolution is improved. In particular, it is possible to apply a load to the load detection sensor only to a half of the measured load. Further, since the weight measuring device is unitized, it can be easily incorporated into various devices.

Further, the seat weight measuring device of the present invention includes four weight measuring devices, and the objects to be measured are an occupant and a vehicle seat, and two seat tracks are provided on the left and right of the lower end of the vehicle seat, respectively. A movable body is attached to the front and rear of each seat track so as to correspond to four corners around the lower end of the vehicle seat, and the base is fixed to a vehicle body as an attached body. It is characterized by having. With this configuration,
A seat weight measuring device in which the load applied to the load detection sensor is reduced and the detection resolution is improved is obtained. In particular, it is possible to apply a load to the load detection sensor only to a half of the measured load. Further, since each of the weight measuring devices is unitized, it is easy to incorporate the weight measuring device between the vehicle body and the vehicle seat.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention according to claim 1 of the present invention provides a base fixed to an object to be mounted, a load detection sensor mounted on the base, and an integral or separate member provided on the base. A leaf spring suspended by a supporting portion, an application point of the load detection sensor and a support point on the support portion, and supported from above and below so as to be substantially immovable in the vertical direction between the application point and the support point. And a movable body that is connected near the center of the leaf spring and that receives the load of the object to be measured and that can move vertically.
This has the effect of reducing the load on the load detection sensor and improving the detection resolution. In particular, it is possible to apply a load to the load detection sensor only to a half of the measured load.
In addition, since the weight measuring device is unitized, it has an effect that it can be easily incorporated into various devices.

According to a second aspect of the present invention, in the first aspect of the present invention, the operating point and the supporting point for supporting the leaf spring are:
Since the leaf spring is supported so as to be displaceable by a predetermined amount in the front-rear and left-right directions, it is possible to prevent the load detection sensor from being damaged by play due to dimensional tolerances of components and abnormal front-rear and left-right forces generated during measurement. Has an action.

According to a third aspect of the present invention, in the first aspect of the invention, an elliptical hole having a cross-sectional shape is formed at two locations of the base so as to face each other, and a substantially center of the leaf spring is provided. The movable body is fixed to the leaf spring by an axis in the vicinity of the portion, and the axis is configured to be movable only substantially in the vertical direction by the hole, so that the forward and backward movement of the movable body is suppressed, and It has the effect of being able to move up and down easily.

According to a fourth aspect of the present invention, in the first aspect of the invention, an elliptical hole having a cross-sectional shape is formed at two locations of the base so as to face each other, and the center of the leaf spring is substantially at the center. The movable body and the leaf spring are pivotally supported by a shaft in the vicinity of the portion, and the shaft is configured to be movable only approximately in the vertical direction by the hole, so that the movable body can freely rotate, and the movable body Can be securely attached to the object to be measured.

According to a fifth aspect of the present invention, in the third or fourth aspect of the present invention, the shaft is brought into contact with an inner wall in a longitudinal direction of the oval hole when a predetermined maximum measured load is exceeded. Therefore, even when a load greater than the maximum measured load or an abnormal vertical force is applied to the object to be measured, the load detection sensor is not damaged.

According to a sixth aspect of the present invention, there is provided a seat weight measuring apparatus having four weight measuring apparatuses according to the first aspect, wherein the objects to be measured are an occupant and a vehicle seat, and a lower end of the vehicle seat. Seat tracks on each side
A movable body is attached to the front and rear of each seat track so as to correspond to four corners around the lower end of the vehicle seat, and the base is fixed to a vehicle body as an attached body. Therefore, the load applied to the load detection sensor is reduced and the detection resolution is improved. In particular, it is possible to apply a load to the load detection sensor only to a half of the measured load. In addition, since each weight measuring device is unitized, not only is it easy to assemble when assembling the vehicle seat, but also the man-hour for assembling can be reduced, and there is no need to adjust the sensor characteristics at the time of assembling. It also has an effect.

According to a seventh aspect of the present invention, there is provided a seat weight measuring apparatus having four weight measuring apparatuses according to the first aspect, wherein the objects to be measured are an occupant and a vehicle seat, and a lower end of the vehicle seat. The movable body is attached to each of the four corners around the vehicle, and the base is fixed to two seat tracks as attached bodies attached in the front-rear direction of the vehicle body. This has the effect of reducing the load and improving the detection resolution.
In particular, it is possible to apply a load to the load detection sensor only to a half of the measured load. In addition, since each weight measuring device is unitized, not only is it easy to assemble, but also by mounting the movable body directly on the vehicle seat, the weight of the seat truck is not superimposed on the load detection sensor, and the vehicle seat Since the calculation of the weight and the resetting performed in advance can be performed with higher accuracy, the operation of detecting the weight of the occupant can be improved.

The invention according to claim 8 is the invention in which a base fixed to an attached body, a load detection sensor attached to the base, a support unit provided integrally or separately to the base, A rotating body rotatably supported by the section, one end of which is attached to one side of the rotating body, and the other end is connected to the operating point of the load detection sensor, and at this operating point A leaf spring supported from above and below so as to be substantially immovable in the up and down direction, and a movable body capable of receiving a load of an object to be measured attached to the other side of the rotating body and being movable up and down. Therefore, there is an effect that the load applied to the load detection sensor is reduced and the detection resolution is improved. In particular, the ratio of the distance from the center of rotation of the rotating body to the point of application of the load detection sensor and the ratio of the distance from the center of rotation of the rotating body to the mounting point of the rotating body and the movable body can be freely varied. This has the effect that the load can be significantly reduced and the detection resolution can be made extremely high. Also, since the weight measurement device is unitized,
It also has the effect that it can be easily incorporated into various devices.

According to a ninth aspect of the present invention, in the invention according to the eighth aspect, when a predetermined maximum measured load is exceeded,
Because the rotating or movable part is in contact with the base, the load detection sensor will not be damaged even if a load exceeding the maximum measured load or an abnormal vertical force is applied to the workpiece. It has the action of:

According to a tenth aspect of the present invention, in the invention of the eighth aspect, at the point of action for supporting the leaf spring,
Since the leaf spring is supported so as to be displaceable by a predetermined amount in the front-rear and left-right directions, it is possible to prevent the load detection sensor from being damaged by play due to dimensional tolerances of components and abnormal front-rear and left-right forces generated during measurement. Has an action.

According to an eleventh aspect of the present invention, in the seat weight measuring device provided with four weight measuring devices according to the eighth aspect, the objects to be measured are an occupant and a vehicle seat, and a lower end of the vehicle seat. Two seat trucks are attached to the left and right sides of the vehicle, and movable bodies are attached to the front and rear of each seat truck so as to correspond to four corners around the lower end of the vehicle seat,
Since the base is fixed to the body as the body to be attached,
This has the effect of reducing the load on the load detection sensor and improving the detection resolution. In particular, the ratio of the distance from the center of rotation of the rotating body to the point of application of the load detection sensor and the ratio of the distance from the center of rotation of the rotating body to the mounting point of the rotating body and the movable body can be freely varied. This has the effect that the load can be significantly reduced and the detection resolution can be made extremely high. In addition, since each weight measurement device is unitized, not only is it easy to assemble it when assembling it to the vehicle seat, but also the assembly man-hour can be reduced,
In addition, there is an effect that it is not necessary to adjust the sensor characteristics at the time of assembly.

According to a twelfth aspect of the present invention, in the seat weight measuring device provided with four weight measuring devices according to the eighth aspect, the objects to be measured are an occupant and a vehicle seat, and a lower end of the vehicle seat. The movable body is attached to each of the four corners around the vehicle, and the base is fixed to two seat tracks as attached bodies attached in the front-rear direction of the vehicle body. This has the effect of reducing the load and improving the detection resolution. In particular, the ratio of the distance from the center of rotation of the rotating body to the point of application of the load detection sensor and the ratio of the distance from the center of rotation of the rotating body to the mounting point of the rotating body and the movable body can be freely varied. This has the effect that the load can be significantly reduced and the detection resolution can be made extremely high. In addition, since each weight measuring device is unitized, not only is it easy to assemble, but also by mounting the movable body directly on the vehicle seat, the weight of the seat truck is not superimposed on the load detection sensor, and the vehicle seat Since the calculation and reset of the weight can be performed with higher accuracy, there is an effect that the detection accuracy of the occupant's weight can be improved.

FIG. 1 shows an embodiment of the present invention.
This will be described with reference to FIGS.

(Embodiment 1) FIG. 1 is an exploded perspective view of a weight measuring device according to a first embodiment of the present invention with a cover removed, FIG. 2 is a sectional side view of the same, and FIG. It is the same top view. Hereinafter, in this specification, the terms up, down, front and rear, and left and right simply refer to the directions of the arrows shown in FIG.

Reference numeral 1 denotes a base fixed to a body to be mounted (not shown). Reference numeral 2 denotes a load detection sensor (for example, a sensor having a strain resistance formed on the surface by printing), and mounting holes 3a, 3b, 3c, 3c. Using 3d, screws 5 are attached to the mounting screw portions 4a, 4b, 4c, 4d provided on the base 1.
a, 5b, 5c, and 5d. Mounting hole 3
At a point where a straight line connecting a and 3d and a straight line connecting holes 3b and 3c intersect, a hole 6 is provided as an action point to which a load is applied. Around the hole 6, an appropriate hole 7 for generating a detectable level of strain and a resistor 8 whose resistance value changes depending on the strain are appropriately formed.

Reference numeral 9 denotes an operation pin, which is made of a material having a proof strength not less than the measured load, has a threaded portion 9a at its tip, and a recess which functions as an action point at a substantially central portion of the operation pin 9. 9b is formed. The load detection sensor 2 is fixed by a nut 10 through an operation pin 9 passing through the hole 6.

Reference numeral 11 denotes a fixing pin as a supporting portion, which is made of a material having a proof strength equal to or larger than the measured load, like the operating pin 9, and has a threaded portion 11 a at a tip end thereof, and a substantially center portion of the fixing pin 11. A concave portion 1 which further functions as a support point
1b is formed and fixed to the screwing portion 12 of the base 1. Further, in a state where the load detection sensor 2 including the operation pin 9 and the fixing pin 11 are assembled on the base 1, the recess 9 b of the operation pin 9 and the recess 11 b of the fixing pin 11 are configured to have substantially the same height. ing.

Reference numeral 13 denotes a leaf spring, and a guide hole 13a through which the shaft 14 passes is formed substantially in the center. Guide hole 13a
May be manufactured by plastic working from a leaf spring 13 as shown in FIG. 1 or may be constituted by a combination with another member (not shown). In addition, the guide hole 13a has a size that allows the guide hole 13a to be combined substantially without play in the vertical and vertical directions when the shaft 14 is passed through. Both ends of the leaf spring 13 are U
Character-shaped notches 13b and 13c are provided.

The notches 13b and 13c are engaged with the recess 9b of the operation pin 9 and the recess 11b of the fixing pin 11 so as to be substantially immovable in the vertical direction. The leaf spring 13 is designed to have a spring characteristic according to the measured load.

Reference numeral 15 denotes an arm as a movable body which receives the load of the object to be measured and can move in the vertical direction. The arm 15 is made of a plate material bent in a substantially U-shape, and the bent wing portions 15a and 15b have shafts. Holes 15c and 15d are respectively formed so that the arm 15 can be rotated through the passage 14.

Next, these assembling methods will be described.

First, the operation pin 9 is fixed to the load detection sensor 2 with the nut 10. Next, the load detection sensor 2 is fixed to the base 1 with screws 5a to 5d. Further, the U-shaped notch 13b of the leaf spring 13 is
In addition, the U-shaped notch 13 c is
The fixing pin 11 is fixed to the screwing portion 12 of the base 1 in a state where the fixing pin 11 is engaged with the fixing pin 11. Next, the wings 15a, 1
The leaf spring 13 is disposed at a position where the holes 15c and 15d formed in the 5b and the guide hole 13a of the leaf spring 13 coincide with each other, passes through the shaft 14, and passes through the elongated holes 16a and 16b formed in the side wall of the base 1. The arm 15 is assembled and fixed with the nut 17. Here, although not shown, the opening and the like are appropriately covered with a cover. Thus, the weight measuring device is completed in principle.

Next, this operation will be described.

When the weight of the object to be measured is applied via the arm 15 of the weight measuring device completed as described above, the operation pin 9 attached to the load detection sensor 2 and the fixed pin 11 attached to the base 1 are moved. The leaf spring 13 suspended between the both ends receives a load in a state where both ends are supported, and generates bending. At this time, since the load is concentrated almost at the center of the leaf spring 13,
A load that is の of the weight of the measured object is applied to the point of action of the load detection sensor 2. Distortion occurs in the load detection sensor 2 according to the applied load. Accordingly, the resistance value of the resistor 8 changes. This change in resistance is calculated by a processing circuit (not shown) and the load is measured.

When the load in the pulling direction is measured, the leaf spring 13 is bent upward by pulling the arm 15 upward, and a signal of the opposite sign is output via the load detecting sensor 2. Is done.

As is apparent from the present embodiment, only half of the measured load is applied to the load detection sensor 2, and the resolution of load detection can be improved.

Further, since the weight measuring device is unitized, even when assembling to various devices, the assembling is easy, the number of assembling steps can be reduced, and it is not necessary to adjust the sensor characteristics at the time of assembling.

With the above configuration, there is no problem in normal weight measurement, but when a load greater than the maximum measured load is applied via the arm 15, a large load is also applied to the leaf spring 13 and the load detection sensor 2. . As a result, permanent deformation or breakage of the leaf spring 13 and breakage of the load detection sensor 2 are concerned. As a countermeasure, a method of increasing the proof stress of the leaf spring 13 and the load detection sensor 2 can be considered.
When the proof stress increases, the amount of strain with respect to the load in the measurement range decreases, and the measurement resolution decreases.

In order to solve this problem, long holes 16a and 16b are provided in the side wall of the base 1. This long hole 16
a, 16b are vertically larger than the diameter of the shaft 14,
In addition, the length is set such that the shaft 14 can move in the vertical direction by the maximum deflection amount of the leaf spring 13 with the maximum measured load.

Thus, when the maximum measured load is exceeded, the shaft 14 comes into contact with the inner walls of the slots 16a and 16b and stops.
Therefore, even if a load greater than the maximum measured load or an impact load is applied, the stopper structure receives the load, so that the load detection sensor 2 and the leaf spring 13 can be prevented from being damaged.

The dimensions of the notches 13b, 13c provided at both ends of the leaf spring 13 in the width direction (left-right direction in FIG. 1) and the longitudinal direction (front-rear direction in FIG. The dimension is set to be larger than the diameter of the concave portion 11 b of the fixing pin 11. This is because when an abnormal force is applied in the front-rear direction or the left-right direction of the object to be measured, the apparatus, or the attached body during the measurement or during the measurement standby, the force is directly applied to the recess 9b of the operation pin 9. The purpose is to prevent it. For example, if an abnormal force is considered as an impact load at the time of a vehicle collision, 2000
The load becomes more than kg. At this time, the weight measurement device
Although the shaft 14 and the base 1 are designed not to be damaged by the proof stress, in the process of applying the shock, the shaft 14 and the respective structures are slightly bent to absorb the shock. Like clearance in anticipation of the deflection,
The dimensions of the notches 13b and 13c of the leaf spring 13 are determined. This can prevent the load detection sensor 2 from being damaged even if it receives a shock from the front, rear, left and right directions.

FIG. 4 is a side view for explaining a state in which four weight measuring devices shown in FIG. 1 are assembled under a vehicle seat. Reference numeral 20 denotes a vehicle seat (for example, a passenger seat), and a seat truck 18 is attached to a lower portion thereof. Reference numeral 19 denotes a weight measuring device shown in FIG. 1, and the arm 15 shown in FIG. 1 is fixed to the seat track 18 with bolts and nuts (not shown). On the other hand, a base 1 shown in FIG. 1 is a bolt and a nut (also not shown).
Is fixed to the vehicle body 50. The weight measuring devices 19 are respectively attached to the front and rear of the seat track 18 so as to correspond to four corners around the lower end of the vehicle seat 20. In this state, the occupant actually enters the vehicle seat 2
The weight at the time of sitting at 0 is measured by the four weight measuring devices 19 and subjected to arithmetic processing to determine the weight. At this time, the load of the vehicle seat 20 itself is set in advance or
Correction is possible by storing it in memory. By attaching the weight measuring device 19 to the front and rear of the seat truck 18 so as to correspond to the four corners around the lower end of the vehicle seat 20, even if the occupant's seating position on the vehicle seat 20 slightly changes, Weight discrimination is possible,
By comparing the loads, the seating position can be estimated.

Although not shown, the weight measuring device 19
The same purpose can be obtained by assembling between the vehicle seat 20 and the seat track 18. As a result, the weight of the seat track 18 is not superimposed on the load detection sensor 2 shown in FIG. 1, so that the weight to be corrected is reduced, and the accuracy of calculation and resetting performed in advance is improved, and as a result, the detection accuracy can be improved. Becomes

As described above, by arranging an appropriate number of weight measuring devices under the vehicle seat, a good seat weight measuring device can be realized.

(Embodiment 2) FIG. 5 is an exploded perspective view of a weight measuring device according to a second embodiment of the present invention with a cover removed, FIG. 6 is a side sectional view of the same, and FIG. It is the same top view.

In this embodiment, the same components as those of the first embodiment shown in FIGS. 1 to 4 are denoted by the same reference numerals, and detailed description thereof will be omitted. Only different portions will be described in detail.

Reference numeral 22 denotes a rotating body.
5 is provided, and is rotatably supported by a shaft 23 between holes 24a and 24b provided in the side wall of the base 1. Further, a wing 26 a extending from one end of the rotating body 22,
Holes 27a and 27b are provided in 26b, respectively. Reference numeral 28 denotes an arm as a movable body which can receive the load of the object to be measured and can move in the vertical direction. The arm 28 is made of a plate material bent in a substantially U-shape.
Holes 28c and 28d are formed in a and 28b, respectively, so that the shaft 28 can pass through and the arm 28 can rotate.
By penetrating the holes 27 a, 28 c, 27 b, and 28 d by the shaft 29, the arm 28 is rotatably supported together with the rotating body 22.

Numeral 30 denotes a leaf spring, one end of which is a rotating body 22.
Mounting holes 32a and 32b are provided at positions corresponding to the plate spring mounting screw holes 31a and 31b, and U
A letter-shaped notch 33 is provided. The notch 33 is engaged with the concave portion 9b of the operation pin 9 so as to be substantially immovable in the vertical direction. The leaf spring 30 is designed to have a spring characteristic according to the measured load.

Next, these assembling methods will be described.

First, the operation pin 9 is fixed to the load detection sensor 2 with the nut 10. Next, the load detection sensor 2 is fixed to the base 1 with screws 5a to 5d. Rotating body 2
2, the leaf spring 30 is fixed with screws 34a and 34b. Further, the arm 28 is attached to the rotating body 22 by the shaft 29.
In this state, the U-shaped notch 33 of the leaf spring 30 is engaged with the concave portion 9 b of the operation pin 9, and the rotating body 22 is supported on the base 1 by the shaft 23. The shaft 23 is fixed by a nut 40. Here, although not shown, the opening and the like are appropriately covered with a cover. Thus, the weight measuring device is completed in principle.

Next, this operation will be described.

When the weight of the object to be measured is added via the arm 28 of the weight measuring device completed as described above, the shaft 23
With the fulcrum as a fulcrum, a force to lower the arm 28 side acts. The force generates a force for lifting the leaf spring 30 upward via the rotating body 22. Therefore, it is a force for pulling up the operation pin 9 attached to the load detection sensor 2. Accordingly, the load detection sensor 2 is distorted. Accordingly, the resistance value of the resistor 8 changes. This change in resistance is calculated by a processing circuit (not shown) and the load is measured. At this time, since the load detection sensor 2 generates distortion but hardly displaces, the leaf spring 30 bends to absorb the displacement due to the weight of the measured object via the arm 28.

At this time, the distance from the center of rotation of the rotating body 22 to the point of application of the load detection sensor 2 and the axis 2 as a mounting point of the rotating body 22 and the arm 28 from the center of rotation of the rotating body 22
Since the ratio of the distance to the center of 9 can be freely changed, the load on the load detection sensor 2 can be significantly reduced, and the detection resolution can be increased.

In particular, by setting the distance from the center of rotation of the rotating body 22 to the point of application of the load detection sensor 2 to be at least twice the distance from the center of rotation of the rotating body 22 to the center of the shaft 29, The load applied to the detection sensor 2 can be further reduced, and the resolution of load detection can be further improved.

Further, since the weight measuring device is unitized, it is easy to assemble and reduce the number of assembling steps even when assembling to various devices, and it is not necessary to adjust the sensor characteristics at the time of assembling.

With the above configuration, there is no problem in normal weight measurement, but when a load greater than the maximum measured load is applied via the arm 28, a large load is also applied to the leaf spring 30 and the load detection sensor 2. . Thus, there is a concern that the leaf spring 30 may be permanently deformed or damaged, or the load detection sensor 2 may be damaged. As a countermeasure, a method of increasing the proof stress of the leaf spring 30 and the load detection sensor 2 can be considered.
When the proof stress increases, the amount of strain with respect to the load in the measurement range decreases, and the measurement resolution decreases.

In order to solve this problem, a part of the wings 28a and 28b of the arm 28 is provided with a projection 2 facing the base 1.
8e and 28f are provided. When the arm 28 is turned around the shaft 23 as a fulcrum and the arm 28 is lowered, the arm 28 comes into contact with the bottom surface 1b of the base 1 when a predetermined stroke is reached. In this case, the stroke is generally designed to be 2 mm from the relation of the maximum measured load. On the other hand, when measuring the load in the pulling direction, the protrusions 36a and 36b facing the base 1 are similarly provided on the tip of the rotating body 22 at the bottom 1b of the base 1.
Touch The stroke is likewise designed to be 2 mm.

Thus, when the maximum measured load is exceeded, a stopper is formed between the protrusions 28e and 28f provided on the arm 28 or the protrusions 36a and 36b provided on the rotating body 22 and the bottom surface 1b of the base 1. You. Therefore, even if a load greater than the maximum measured load or an impact load is applied, the stopper structure receives the load, so that the load detection sensor 2 and the leaf spring 30 can be prevented from being damaged.

The dimensions of the notch 33 provided at the other end of the leaf spring 30 in the width direction (horizontal direction in FIG. 5) and the longitudinal direction (front-back direction in FIG. 5) are determined by the diameter of the concave portion 9b of the operating pin 9. It is set to a larger dimension. This is because when an abnormal force is applied in the front-rear direction or the left-right direction of the object to be measured, the apparatus, or the attached body during the measurement or during the measurement standby, the force is directly applied to the recess 9b of the operation pin 9. The purpose is to prevent it.
For example, when an abnormal force is considered as an impact load at the time of a vehicle collision, the load becomes 2000 kg or more. Even at this time, the weight measuring device is designed not to be damaged by the strength of the shaft 23 and the base 1, but in the process of applying the impact, the shaft 23 and each of the structures slightly bend to generate an impact. Absorb. The size of the notch 33 of the leaf spring 30 is determined so that the clearance allows for the deflection. This can prevent the load detection sensor 2 from being damaged even if it receives an impact from the front, rear, left and right directions.

By incorporating the weight measuring device of the present embodiment below the vehicle seat as described in the first embodiment, a good seat weight measuring device can be realized.

[0058]

As described above, the present invention provides a base fixed to an object to be mounted, a load detection sensor mounted on the base, a support unit provided integrally or separately on the base, and A leaf spring suspended from the vertical direction so as to be suspended in the vertical direction at the point of application and the supporting point and suspended at the point of action of the load detection sensor and the supporting point of the supporting portion; And a movable body connected near the center and capable of receiving a load of the object to be measured and movable in a vertical direction.
With this configuration, it is possible to obtain a weight measuring device in which the load on the load detection sensor is reduced and the detection resolution is improved. In particular, it is possible to apply a load to the load detection sensor only to a half of the measured load. Further, since the weight measuring device is unitized, it can be easily incorporated into various devices.

The seat weight measuring device of the present invention includes four weight measuring devices, and the objects to be measured are an occupant and a vehicle seat, and two seat tracks are provided on the left and right of the lower end of the vehicle seat, respectively. A movable body is attached to the front and rear of each seat track so as to correspond to four corners around the lower end of the vehicle seat, and the base is fixed to a vehicle body as an attached body. It is characterized by having. With this configuration,
A seat weight measuring device in which the load applied to the load detection sensor is reduced and the detection resolution is improved is obtained. In particular, it is possible to apply a load to the load detection sensor only to a half of the measured load. Further, since each of the weight measuring devices is unitized, it is easy to incorporate the weight measuring device between the vehicle body and the vehicle seat.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of the present invention with a cover removed.

FIG. 2 is a side sectional view of the same.

FIG. 3 is a plan view of the same.

FIG. 4 is a side view for explaining a state in which the weight measuring device shown in FIG. 1 is incorporated.

FIG. 5 is an exploded perspective view with a cover removed for explaining a second embodiment of the present invention;

FIG. 6 is a side sectional view of the same.

FIG. 7 is a plan view of the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base 1b Bottom surface 2 Load detection sensor 3a, 3b, 3c, 3d Mounting hole 4a, 4b, 4c, 4d Mounting screw part 5a, 5b, 5c, 5d Screw 6, 7 hole 8 Resistor 9 Operating pin 9a, 11a Screw processing Part 9b, 11b Concave part 10, 40 Nut 11 Fixing pin 12 Screw part 13 Leaf spring 13a Guide hole 13b, 13c Notch 14 Axis 15 Arm 15a, 15b Wing part 15c, 15d Hole 16a, 16b Slot 17 Nut 18 Sheet track 19 Weight measuring device 20 Vehicle seat 22 Rotating body 23 Shaft 24a, 24b, 25 hole 26a, 26b Wing 27a, 27b hole 28 Arm 28a, 28b Wing 28c, 28d Hole 28e, 28f Projection 29 Shaft 30 Leaf spring 31a, 31b Screw holes for attaching leaf springs 32a, 32b 33 notches 34a, 34b screws 36a, 36b projections 50 body

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor ▲ Yoshi ▼ Shigehiro Uchi 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F term (reference) 3B087 DE08 3D054 EE10

Claims (12)

[Claims] 1. A base fixed to a body to be mounted, a load detection sensor mounted on the base, a support unit integrally or separately provided on the base, and a point of action of the load detection sensor. A leaf spring suspended by a support point on the support portion, and supported from above and below so as to be substantially immovable in the up and down direction at the action point and the support point, is connected near the center of the leaf spring substantially, And a movable body that receives a load of the object to be measured and that can move vertically. 2. The weight measuring device according to claim 1, wherein the leaf spring is supported so as to be displaceable by a predetermined amount in a front-rear direction and a left-right direction at an operation point and a support point supporting the leaf spring. 3. A hole having an oval cross section is formed at two locations of the base so as to face each other, and a movable body is fixed to the leaf spring by a shaft near an approximate center of the leaf spring. 2. The weight measuring device according to claim 1, wherein said shaft is configured to be movable only approximately in the vertical direction by said hole. 4. An elliptical hole having a cross-sectional shape is formed at two locations of the base so as to face each other, and a movable body and the leaf spring are supported by a shaft near an approximate center of the leaf spring.
The weight measuring device according to claim 1, wherein the shaft is configured to be movable only in a substantially vertical direction by the hole. 5. The weight measuring device according to claim 3, wherein the shaft comes into contact with an inner wall in a longitudinal direction of the oval hole when the load exceeds a predetermined maximum measurement load. 6. A seat weight measuring device comprising four weight measuring devices according to claim 1, wherein the objects to be measured are an occupant and a vehicle seat, and seat tracks are provided on the left and right of lower ends of the vehicle seat. Two movable members are attached to the front and rear of each seat track so as to correspond to four corners around the lower end of the vehicle seat, and the base is a vehicle body as an attached member. Seat weight measurement device fixed to. 7. A seat weight measuring device provided with four weight measuring devices according to claim 1, wherein the objects to be measured are an occupant and a vehicle seat, and are located at four corners around a lower end of the vehicle seat. A seat weight measuring device in which movable bodies are respectively mounted so as to correspond to each other, and a base is fixed to two seat tracks as mounted bodies mounted in the front-rear direction of the vehicle body. 8. A base fixed to an attached body, a load detection sensor attached to the base, a support unit provided integrally with or separately from the base, and a shaft rotatably mounted on the support unit. A supported rotating body, one end of which is attached to one side of the rotating body, and the other end is connected to the point of action of the load detection sensor, and is substantially immobile in the vertical direction at this point of action. A leaf spring supported from above and below,
A weight measuring device comprising: a movable body that receives a load of an object to be measured attached to the other side of the rotating body and that can move vertically. 9. The weight measuring device according to claim 8, wherein a part of the rotating body or the movable body comes into contact with the base when the load exceeds a predetermined maximum measurement load. 10. The weight measuring device according to claim 8, wherein the leaf spring is supported so as to be displaceable by a predetermined amount in the front-rear and left-right directions at an action point for supporting the leaf spring. 11. A seat weight measuring apparatus provided with four weight measuring apparatuses according to claim 8, wherein the objects to be measured are an occupant and a vehicle seat, and seat tracks are provided on left and right of lower ends of the vehicle seat. Each has two attached,
A movable body is attached to each of the four corners around the lower end of the vehicle seat before and after each seat truck, and a base is fixed to a vehicle body as an attached body, and a seat weight measuring device. . 12. A seat weight measuring device comprising four weight measuring devices according to claim 8, wherein the objects to be measured are an occupant and a vehicle seat, and are located at four corners around a lower end of the vehicle seat. A seat weight measuring device in which movable bodies are respectively mounted so as to correspond to each other, and a base is fixed to two seat tracks as mounted bodies mounted in the front-rear direction of the vehicle body.