JPH08254456A - Sensing element for load measurement and load measuring pin sensor - Google Patents

Abstract

PURPOSE: To provide a sensing element and a pin sensor for measuring the load, with which the linearity of the output relative to the car loaded weight is enhanced. CONSTITUTION: A curved notch 21a is provided at each inner corner of a plate- shaped member 21 consisting of a magnetic material, and four holes 22 are bored in the plate 21. Coils 23, 24 are installed in these holes 22 in a crossing arrangement, and the ends of the coils 23, 24 are drawn out as leads 23a, 24a. At the side walls, fit flanges 25a, 25b are formed, and protrusive shafts 26a, 26b are installed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load measuring sensing element and a load measuring pin sensor used to measure the weight of a vehicle, and more particularly to improving the linearity of the output to improve the measuring accuracy. The present invention relates to a load measuring sensing element and a load measuring pin sensor.

[0002]

2. Description of the Related Art As is well known, in large vehicles, it is obligatory to install a load measuring device (self-weight meter) for measuring the load weight of a loading platform in order to prevent a traffic accident. The accuracy is checked regularly. A load measuring sensing element and a load measuring pin sensor used in a conventional load measuring device will be described with reference to FIGS. 7 to 9.

A load measuring sensing element will be described with reference to FIG. In the figure, the sensing element 1 has four holes 2 formed in a rectangular plate-shaped member 1a made of a magnetic material such as permalloy, and a protruding shaft 1b integral with the plate-shaped member 1a is formed from the side surface of the plate-shaped member 1a. , 1c are formed. The coil 3 is used to make a hook using these holes 2.
a and 3b are assembled, and the ends of the coils 3a and 3b are drawn out as lead wires.

Next, the load measuring pin sensor will be described with reference to FIG. In the figure, 6 indicates a load measuring pin sensor, and an insertion hole 7a is formed in a cylindrical engagement shaft (hereinafter referred to as a pin) 7. In the sensing element 1, the protruding shaft 1b is fitted with the tapered holding member 4, and the protruding shaft 1c is fitted with the cylindrical holding member 5, so that the sensing element unit S is formed. The sensing element unit S has an insertion hole 7a formed in the pin 7.
And the load measuring pin sensor 6 is formed.

FIG. 8 is a view showing a main part of a vehicle in which the load measuring pin sensor 6 is mounted. In the figure, a bracket 9 is attached to a carrier frame of a vehicle 8, a front end 10a of a leaf spring 10 provided with a front wheel 12 is attached to the carrier frame via the bracket 9, and a rear end 10b thereof is attached.
Is attached to the carrier frame via the shackle 11 and the bracket 9. The bracket 9 and the shackle 11 are engaged with a pin in which a load measuring sensing element is embedded, that is, a load measuring pin sensor 6.

[0006]

The load measuring pin sensor 6 has a bracket 9 and a shackle 1 as shown in FIG.
1 is attached to the engaging portion. Therefore, FIG.
As shown in (a), shearing forces P1 and P2 are applied to the pin sensor 6 as shown by the arrows, depending on the loaded weight of the vehicle. Although FIG. 9C is an exaggerated view, when the pin sensors 6 are subjected to shearing forces P1 and P2, the pin sensors 6 are distorted. The amount of strain depends on the diameter of the pin sensor. When shearing forces P1 and P2 are applied to the pin sensor 6, shearing forces A and B are applied to the sensing element unit S, and stress is generated between A and B of the sensing element unit S. FIG. 9B
[FIG. 3] is a view showing a spring between A and B of the sensing element unit S. The spring constant b between A and B of the sensing element unit S is constant. Therefore, if a large amount of stress is repeatedly applied to the sensing element unit S, the sensing element 1 may be destroyed.

The output characteristics of the load measuring pin sensor will be described with reference to FIG. 6A. In FIG. 6A, the horizontal axis represents strain amount (ε) and the vertical axis represents output voltage (V). Shows. As is clear from the figure, the output characteristics of the load measuring sensing element show that the amount of strain (ε) in the regions R1 and R2 is large.
The rate of change of the output voltage (V) with respect to the change of is different. Therefore, if the load is measured in the range of the regions R1 and R2, the measurement accuracy will be poor. For example, a load measuring pin sensor for measuring the vehicle load will be inferior in the vehicle load measurement accuracy.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a load measuring sensing element and a load measuring pin sensor for improving the linearity of the output with respect to the vehicle load weight. To do.

[0009]

In order to achieve the above object, the present invention has four holes formed in a plate-like member made of a magnetic material, and a coil is struck in the four holes. A load-measuring sensing element that is assembled to the plate-shaped member, characterized in that curved notches are formed at the four corners of the plate-shaped member, and projecting shafts projecting in the longitudinal direction are provided on the side surfaces of the rectangular plate-shaped member. Is.

Further, the present invention is a load measuring sensing element in which four holes are bored in a plate-shaped member made of a magnetic material, and coils are attached to the four holes so as to be hung. It is characterized in that a pair of curved cutouts is provided at two positions on the side surface in the longitudinal direction of the plate-shaped member so that the plate-shaped member between the curved cutouts serves as a sensing portion.

Further, the present invention is a load measuring pin sensor for measuring a vehicle loading weight, wherein a plate-shaped member made of a magnetic material is provided with curved notches, and four holes are formed in the plate-shaped member of the curved notch. And a sensing element unit having a coil as a sensing part by mounting a coil in the hole, and a sensing element unit having a tapered holder in front of the sensing element and a cylindrical holder in the rear. A cylindrical engagement shaft having a tapered insertion hole at the tip, and the sensing element unit is inserted into the insertion hole from the tapered holder side. Is.

Further, the present invention is a load measuring pin sensor for measuring a load weight of a vehicle, wherein curved cutouts are provided at four corners of a plate member made of a magnetic material, and a coil is hung on the plate member. With four holes to be attached to the sensing element, the sensing element having first and second projecting shafts projecting from the side surface of the plate-like member in the longitudinal direction, and the first projecting shaft of the sensing element having a tapered shape. A sensing element unit, which is inserted through a through hole provided in the holder and through which the second projecting shaft is inserted through a through hole provided in the columnar holder, and an insertion hole having a tapered tip portion are provided. The sensing element unit is formed of a cylindrical engagement shaft, and the sensing element unit is inserted into the insertion hole from the tapered holder side.

[0013]

In the load-measuring sensing element of the present invention, the coil is assembled to the coil by the plate-shaped member between the curved cutouts to form the sensing unit, and the width of the plate-shaped member provided with the curved cutout is narrow. Since the spring constant a of that portion is smaller than the spring constant b of the plate-shaped portion (sensing portion) to which the coil is assembled in the crossing, stress concentrates on the portion where the width of the plate-shaped member is narrow. Therefore, since the stress generated in the sensing portion is relaxed, the linearity of the output of the load measuring sensing element is improved. Further, the load measuring pin sensor of the present invention, the load measuring sensing element is mounted in the insertion hole of the cylindrical engaging shaft, the linearity of the output is improved, when used in the load measuring device,
The accuracy of measuring the vehicle load becomes good.

[0014]

Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 is a perspective view showing an embodiment of a load measuring sensing element according to the present invention. In the figure, the load measuring sensing element 20 is made of a magnetic material such as permalloy, and 21 is a plate-shaped member having curved notches 21a at its four corners. Four holes 22 are bored in the plate-like member 21 which is a sensing portion, fitting flanges 25a and 25b are formed on the side surfaces thereof, and cylindrical projecting shafts 26a and 26b are formed in the longitudinal direction of the plate-like member 21. It is protruding. The protrusions 26a and 26b may have a rectangular column shape. In the four holes 22 formed in the plate-shaped member 21,
The coils 23 and 24 are attached to the cross, and their ends are drawn out as lead wires 23a and 24a for external connection.

FIG. 2 is a perspective view showing an embodiment of the load measuring pin sensor according to the present invention. In the figure, the load measuring pin sensor 27 includes a bracket 9 connected to the bogie frame of the vehicle shown in FIG.
0 is used in a portion that engages with a shackle 11 that is rotatably connected. Load measurement pin sensor 27
The cylindrical engaging shaft (hereinafter referred to as a pin) 28 has an insertion hole 28a, and the sensing element unit 29 is inserted into the insertion hole 28a and sealed by the blind lid 19. The tip of the insertion hole 28a is tapered.

Next, the sensing element unit 29 will be described with reference to FIG. In the figure, the sensing element unit 29 includes a load measuring sensing element 20, a tapered holder 30, and a cylindrical holder 31. The tapered holder 30 is provided with a through hole 30a,
The protruding shaft 26b of the sensing element 20 is inserted.
Further, the cylindrical holder 31 is provided with a through hole 31a,
The protruding shaft 26a of the load measuring sensing element 20 is inserted. A groove 32 is provided in the cylindrical holder 31 and is used as a groove for pulling out a lead wire of a coil assembled to the hole 22.

As shown in FIG. 2, the inner wall of the distal end portion 28b of the insertion hole 28a formed in the pin 28 is tapered, and the tapered holder 30 of the sensing element unit 29 is provided.
Fits in this tapered tip portion 28b. The protruding shaft 26b of the sensing element 20 is inserted into the through hole 30a of the tapered holding body 30, and the cylindrical holding body 31 fitted into the insertion hole 28a has the through hole 31a.
The zero protruding shaft 26a is inserted. The plate-shaped member 21 forming the sensing portion is held so as not to contact the inner wall of the insertion hole 28a.

FIG. 4 is a perspective view showing another embodiment of the load measuring sensing element according to the present invention. In the figure, the plate member 21 is made of a magnetic material such as permalloy,
The plate-like member 21 has a coil 23,
Four holes 22 in which 24 are assembled are provided, and the plate-like member 21 has a pair of U-shaped curved cutout portions 21a on the longitudinal side surfaces.
Are provided at two locations to form a sensing section. The plate-shaped portion protruding from the side wall of the sensing unit may have a narrow width. When a sensing element unit is formed using this load measuring sensing element, the plate-shaped member 2 is provided on each of the tapered holder and the cylindrical holder.
A hole through which 1 passes is provided (not shown).

The operation of the load measuring sensing element of the above embodiment will be described with reference to FIGS. 5 (a) and 5 (b). As shown in FIG. 5A, if the taper holder 30 and the columnar holder 31 of the sensing element unit 29 are subjected to shearing forces A and B, the sensing element 2
The elasticity of 0 can be illustrated as a spring as shown in Figure 5 (b). The spring constant a of the curved cutout portion 21a where the plate portion is narrowed and the spring constant b of the plate portion 21
Has a relationship of spring constant a <spring constant b. Therefore, when the shearing forces A and B are applied to the sensing element unit 29,
The curved notch 21a is formed and absorbed by the spring constant a of the narrow plate member, and the stress applied to the plate member 20 can be reduced.

Explaining with reference to FIGS. 6A to 6C, first, as shown in FIG. 6A, in a region R2 where the strain amount (ε) is large, the output voltage (V) is relative to the strain amount. Since the rate of change of the output voltage (V) becomes small, the range R of FIG.
If the vehicle load weight is measured with 1 and R2, the load weight measurement accuracy becomes poor. However, according to the load measuring sensing element of the present embodiment, the stress of the sensing portion can be reduced. Moreover, the relationship between the strain amount (ε) and the stress (Q) is in a proportional relationship as shown in FIG. 6 (b). Therefore, since the amount of strain applied to the sensing unit can be made small by the configuration of the embodiment, as shown in FIG. 6C, the load measurement pin sensor can improve the linearity of the output characteristic in the range actually used for measurement. Can be improved.

If the load measuring sensing element of the embodiment is used for the load measuring pin sensor, the weight of the vehicle can be measured in a range of good linearity, so that the accuracy of measuring the load of the vehicle can be improved. Incidentally, in the above embodiment, the load measuring sensing element, the tapered holder and the columnar holder are separate bodies, but the load measuring sensing element and the tapered holder may be formed integrally. Good. Further, it is obvious that the load measuring sensing element and the tapered holder and the cylindrical holder may be integrally formed.

[0022]

As described above, in the load measuring sensing element of the present invention, the plate-shaped member having the curved notch portion and narrowed in width is connected to the plate-shaped member to which the coil is assembled. Since the spring constant a of the plate-shaped member having a narrower width is set to be smaller than the spring constant b of the plate-shaped member (sensing part) of the sensing part, it is possible to reduce the stress applied to the sensing part. There is an advantage that the linearity of the output characteristics of the device is good.

The load measuring pin sensor of the present invention comprises:
A load measuring sensing element that has linear output characteristics is used, and by using it as a load measuring device for measuring the loaded weight of large vehicles, it is possible to provide a highly reliable load measuring device, There is an advantage that the measurement accuracy of can be improved. Further, the load measuring sensing element of the present invention has an advantage that it is not broken by the stress due to the repeated shearing force.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a load measuring sensing element according to the present invention.

FIG. 2 is a perspective view showing an embodiment of a load measuring pin sensor according to the present invention.

FIG. 3 is a perspective view of a sensing element unit.

FIG. 4 is a perspective view showing another embodiment of the load measuring sensing element according to the present invention.

5 (a) and 5 (b) are views for explaining the operation of the load measuring sensing element.

6A is a diagram showing the relationship between the strain amount and the output voltage of the load measuring sensing element, FIG. 6B is a diagram showing the relationship between the stress and the strain amount, and FIG. 6C is a diagram showing the relation between the output voltage and the stress. Is.

FIG. 7A is a front view of a conventional load measuring sensing element, and FIG. 7B is a view showing a load measuring pin sensor.

FIG. 8 is a schematic view of a large vehicle equipped with a load measuring pin sensor.

9 (a) to 9 (c) are views for explaining the operation of a conventional load measuring pin sensor.

[Explanation of reference signs] 19 Blind lid 20 Sensing element for load measurement 21 Plate member 21a Curved notch 22 Hole 23, 24 Coil 23a, 24a Lead wire 25a, 25b Fitting collar 26a, 26b Projection shaft 27 Load measuring pin sensor 28 Cylindrical locking shaft (pin) 29 Sensing element unit 30 Tapered holding part 31 Cylindrical holding part

Claims (4)

[Claims] 1. A load-measuring sensing element comprising a plate-shaped member made of a magnetic material and four holes formed in the plate-shaped member. The coil-shaped mounting unit is provided with curved notches at four corners of the plate-shaped member. A load measuring sensing element, characterized in that a protruding shaft protruding in the longitudinal direction is provided on a side surface of the plate-shaped member. 2. A load measuring sensing element in which four holes are formed in a plate member made of a magnetic material, and a coil is mounted on the plate member, wherein a pair of curved lines is provided on a side surface in the longitudinal direction of the plate member. A load-measuring sensing element, wherein a plate-shaped member between the curved notches is used as a sensing unit by providing two notches. 3. A load measuring pin sensor for measuring a load weight of a vehicle, wherein a plate-shaped member made of a magnetic material is provided with a curved notch, and four holes are bored in the plate-shaped member of the curved notch, A sensing element formed by assembling a coil in a hole, a sensing element unit having a tapered holder in front of the sensing element and a cylindrical holder in the rear, and a tapered tip end A load measuring pin sensor comprising: a cylindrical engagement shaft having a hole, wherein the sensing element unit is inserted into the insertion hole from the tapered holder side. 4. A load measuring pin sensor for measuring a vehicle loading weight, wherein curved notches are provided at four corners of a plate-shaped member made of a magnetic material,
And a sensing element comprising four holes for attaching a coil to the plate member, the first and second projecting shafts projecting in the longitudinal direction on the side surface of the plate member, A sensing element unit in which the first protruding shaft of the sensing element is inserted into a through hole provided in a tapered holding body, and the second protruding shaft is inserted into a through hole of a cylindrical holding body, and a tip portion Is a columnar engagement shaft having a tapered insertion hole, and the sensing element unit is inserted into the insertion hole from the tapered holder side, and a load measuring pin sensor is provided.