JPH0989642A - Vehicle or/and loading weight measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a weight measuring apparatus by which a shear strain (or stress) distribution is found by a finite element method analysis CAE when a shackle pin is subjected to a load and in which a sensing element used to measure a shear strain (or stress) with good efficiency on the basis of the shear distribution is arranged and installed. SOLUTION: A vehicle or/and loading weight measuring apparatus is constituted in such a way that a hole 6 is bored and formed along the axial direction inside a shackle pin 3 by which the suspension side of a vehicle is coupled to a bracket 2 attached to a vehicle body frame and that a sensing element 7 which detects a strain is fitted into, and arranged in, the hole 6. In this case, the detection center of the sensing element 7 is arranged so as to be deviated by a prescribed distance to the axial direction X-X from a belt-shaped gap position C-C between the edge of the bracket and an edge on the side of a leaf spring, and the sensing element 7 is arranged and installed in a position which corresponds nearly to the maximum stress region of shear stress lines on the axial line of the hole 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle or / and a load weight measuring device for a load mounted on a vehicle, and more particularly to a shaft within a shackle pin for connecting a suspension side of a vehicle and a bracket attached to a vehicle body frame. The present invention relates to a vehicle or / and a loaded weight measuring device in which a hole is bored along a direction and a sensing element for detecting strain is fitted and arranged in the hole.

[0002]

2. Description of the Related Art Conventionally, load measurement of a vehicle is mainly performed on a large vehicle such as a truck. Normally, the load of a vehicle is measured by a load measuring device installed on the road.The wheels are placed on a loading plate equipped with a load converter, and the wheel weight or axle weight of the wheels is measured. And the like are added to obtain the vehicle weight, and the weight of the occupant or the vehicle itself is subtracted from the measured vehicle weight to obtain the loaded load.

However, since the load measuring device described above is installed only at a specific place on the road,
In addition, since the load measuring device itself is large and the installation cost is high, there is a limit to the installation location and the number of installations, and it is not possible to place it at all the cargo loading points, so overloading often occurs without the recognition of the driver or the loader. There was a fear that it would occur.

[0004]

In order to eliminate such drawbacks, it is considered to incorporate a load measuring device into the vehicle itself. For example, Japanese Utility Model Laid-Open No. 6-16826 discloses a technique in which a strain gauge type sensing element is arranged in a slide plate or a vehicle height adjusting plate located between a leaf spring of a vehicle and an axle case.

However, in the case where the sensing element is mounted in the slide plate, the leaf spring slides on the surface of the slide plate, so that there is a possibility that the slide plate may be worn and the output characteristic of the sensing element may change due to the strength change. There are some problems.

[0006] In order to eliminate such a defect, the actual flat 6-
No. 69759, a sensing element for drilling a shaft hole along the axial direction on the center line of a shackle pin that connects a shackle supporting a vehicle suspension and a bracket attached to a vehicle body frame, and detecting a strain in the shaft hole Has proposed a vehicle load measuring device in which the two are fitted and arranged.

The structure will be described with reference to FIG. 11. The bracket 2 fixed to the bed frame 1 (not shown).
A cylindrical shackle pin 3 (spring pin) is fitted to the shackle pin 3, and the shackle 4 or the eye portion of the leaf spring 11 is rotatably coupled to the shackle pin 3. Further, a groove 3a is provided on the peripheral surface of the bracket fitting portion of the shackle pin 3, and when the bracket 2 and the shackle are coupled, a pin fixing bolt 5 is inserted into the groove 3a from a hole on the side surface of the bracket 2. By inserting and tightening the shackle pin 3, the shackle pin 3 is fixed to the bracket 2 so as not to rotate and move in the axial direction.
A hollow hole 6 is bored from the end surface of the shackle pin 3 along the central axis direction, and a strain gauge type sensing element 7 is fitted and mounted inside the hole 6. Of course, it is also stated that the sensing element 7 may be composed of a magnetostrictive sensing element 7.

Both ends of these sensing elements 7 are cylindrical and the central portion is formed in a plate shape. For example, in the case of a strain gauge type sensing element 7, the plate portions are made of a magnetic material, and A resistance wire is bonded to that portion, and the lead wire 8 is drawn from the resistance wire.
On the other hand, in the case of the magnetostrictive sensing element 7, the plate-shaped portion is formed of a magnetic material such as permalloy, four small holes are bored in the cross direction, and the coil is wound in a cross shape through the holes. The lead wire is drawn out from the coil. Then, the lead wire 8 is drawn out from the shaft hole 6 of the shackle pin 3. A hole 9 drilled on the side of the shackle pin 3 opposite to the shaft hole 6 is a grease supply hole.

According to such a conventional technique, the load of the vehicle is applied to the shackle pin 3 connecting the bracket 2 and the shackle 4 via the bracket 2. Therefore, a shearing force acts on the shackle pin 3 and the sensing element 7 disposed inside is distorted, so that the vehicle load (specifically, the spring load of the suspension on the shackle pin 3).
Etc. are detected.

In the prior art, in order to effectively detect the shear strain (stress), the detection center of the sensing element is set at a band gap position between the bracket end face and the leaf spring side end face (hereinafter, band gap). Position)
And is fixed in position by the pin fixing bolt 5 inserted into the groove 3a of the shackle pin 3.

However, in the structure in which the detecting portion of the sensing element 7 is arranged at the above-mentioned band-shaped void position, none of sensitivity, accuracy and stability is sufficient for shear strain (stress) measurement, and there are various problems in practical use. It was

In the present invention, as a result of various studies on the factors that make the sensitivity, accuracy, etc. unstable, it is found that there is a problem in the installation position, and in particular, the shackle pin 3 applies the load by the finite element method analysis CAE. Shear strain (stress) when receiving
An object of the present invention is to provide a vehicle or / and a loaded weight measuring device provided with a sensing element 7 for obtaining a distribution and efficiently measuring the shear strain (stress) based on the shear stress distribution.

[0013]

In view of the above technical problems, the present invention provides a hole 6 along an axial direction in a shackle pin 3 that connects a suspension side of a vehicle and a bracket 2 attached to a body frame 1. A vehicle or / where a sensing element 7 for detecting a strain is fitted and arranged in the hole 6
And the loaded weight measuring device, the sensing element 7
The detection center of the bracket 2 between the end face of the bracket 2 and the end face on the leaf spring side (leaf spring 11 or bush 13), and the arrangement position of the sensing element 7 on the bracket end face and the leaf spring side. Axial direction X from the band gap position C-C between the end face
It is characterized in that the sensing element 7 is arranged at a predetermined distance from -X, and the sensing element 7 is arranged at a position substantially corresponding to the maximum stress area of the shear stress diagram on the axis of the hole 6.

That is, as shown in FIG. 1 and FIG.
On the central axis of the shackle pin 3 which coincides with the axis, the maximum stress area of the shear stress diagram is at points P ₁ and P ₂ which are off the inner end surface of the bracket 2, and therefore the inner end surface of the bracket 2 of the shackle pin 3 is 15 in the axial direction with respect to the orthogonal plane
It is preferable to dispose at a point P ₁ or P ₂ with an angle change of up to 50 °, preferably 20 ° to 45 °, and more preferably 20 to 35 °.

Although the maximum stress area is at points P ₁ and P ₂ on the pin center axis, the γ-Y axis surface (the vertical direction of the shackle pin 3 passing through the pin center axis is loaded on the shackle pin 3. In the cross section), as shown in Reference Photograph 2 (color copy), there are maximum stress regions at points P ₃ and P ₄ which are displaced upward from the points P ₁ and P ₂ . (In this case, the positive main stress is the tensile stress, and the negative main stress is the compressive stress, but it is unknown in the drawing, so it is unclear in the reference picture 1 corresponding to Fig. 3 and the maximum on the Χ-Y axis surface where the trunnion shaft receives the load. Reference photograph 2 corresponding to the stress distribution diagram showing the stress region in color is attached.) Therefore, in the case of the present invention, more preferably, the arrangement position of the sensing element 7 is the maximum stress with respect to the central axis of the shackle pin 3. It is preferable to dispose them so as to be displaced in the radial direction on the generation area side. That is, the maximum stress area of the shear stress diagram on the axis of the hole 6 is the points P ₁ and P ₂ on the central axis, and when the hole 6 is formed on any axis of the Χ-Y axis. Can be said to be points P ₃ and P ₄ .

However, since it is necessary to form a hole 6 for fitting the sensing element 7 in the shackle pin 3, it cannot be disposed on the outer peripheral side of the pin far from the strength side, and specifically, the amount of positional deviation in the radial direction is not possible. However, it is preferable that the bending stress of the shackle pin 3 is low, that is, ½ or less of the axial radius.

The maximum stress area is located on both the left and right sides of the band-shaped void position C-C, and the main stresses thereof are in the opposite positive and negative directions (see tensile stress and compressive stress in FIG. 3). Therefore, there are two positions (P ₁ and P ₂ points, and P ₃ and P points) located on the left and right sides of the axial direction and substantially corresponding to the maximum stress area.
_The sensing element 7 is provided at each of _four points, and the difference (ρ ₁ −ρ ₂ or ρ ₃₎ between the output signals of the two sensing elements 7 is provided.
By taking −ρ ₄ ), it is possible to obtain a gain twice as large as that in the case of one, and it is possible to detect a signal with higher sensitivity and accuracy.

A sensor body 70 including the sensing element 7
The output sensitivity is further improved by fitting the shackle pin 3 (see FIG. 13) and the shackle pin 3 by interference fit.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the above-mentioned prior art, a load is applied from the peripheral surface of the lower side of the pin via a shackle or a leaf spring with the upper end of the inner end surface of the bracket 2 fitted and fixed to the shackle pin 3 as a supporting point. In order to receive the shackle pin 3, it was believed that a bending moment and a shearing force based on the beam theory were generated in the shackle pin 3. Therefore, in the prior art, the sensing element 7 is arranged at the support point of the bracket 2, in other words, at the intersection position P ₀ of the inner end surface of the bracket 2 and the pin center axis, and the shear strain (stress) is measured. It was

However, when the shear stress diagram when the shackle pin 3 receives the above-mentioned load is obtained by the finite element method analysis CAE using the super computer,
As shown in FIG. 2, the illustrated rising Naru abrupt on intersections P _0, when the order disposing the sensing element 7 on the intersecting position P _0, the sensitivity also in the installation position of the slight axial low It was found that the signal output (gain) also fluctuates greatly due to fluctuations and a stable gain cannot be obtained.

Therefore, in the present invention, on the central axis of the shackle pin 3, points P ₁ (shackle side) and P ₂ (bracket 2) where the maximum stress region of the shear stress diagram deviates from the inner end surface of the bracket 2. On the side), the sensing element 7 is arranged at either or both of the _two points P _{1 and} P ₂ . FIG. 12 shows the sensing element arranged at the point P ₁ and the intersection position P _0.
It is a graph showing the relationship between the load / gain output of the sensing element arranged at the point, and it can be understood that the sensitivity is more than doubled at the points P ₁ and P ₀ as understood from this figure. The reason why the maximum stress area of the shear stress diagram is present at a position axially displaced from the intersection is that the main stress is inclined in the direction of about 45 ° with respect to the horizontal axis, and therefore the shear stress is in the axial direction. It is estimated that the position will be shifted to a larger position.

In this case, when the sensing element 7 is arranged at the point P ₁ on the shackle side, the maximum stress is higher than that at the point P ₂ on the bracket 2 side, so that the sensitivity is good and the bracket 2
When the sensing element 7 is arranged at the point P ₂ on the side, the curve of the inflection point in the peak area of the maximum stress area is gentler than the point P ₁ on the shackle side, and therefore, there may be some variation in the arrangement position in the axial direction. In addition, the factor in which the gain fluctuates is further reduced, and the stability is further increased.

The stresses at the points P ₁ and P ₂ located on both the left and right sides of the band-shaped void position C-C are P as shown in FIG.
_At points ₁ and P ₂ , the tensile stress (arrow pointing outward) and the compressive stress (arrow pointing toward the center) are located in opposite positive and negative directions, respectively. That is, the directions of shear stress are located in the opposite positive and negative directions. Therefore, as shown in FIG. 1C, the sensing elements 7 are arranged at points P ₁ and P ₂ with the inner end surface of the bracket 2 sandwiched therebetween.
Difference between output signals of the two sensing elements 7 (ρ ₁ −ρ ₂ )
As a result, it is possible to obtain a gain that is about twice as high as when a gain is obtained from one element, and it is possible to detect a signal with higher sensitivity and accuracy.

The load received by the shackle pin 3 is received on the pin X-Y axis plane (a vertical cross section of the shackle pin 3 passing through the pin center axis). Therefore, as shown in the reference photograph 2, the maximum stress generation area on the pin Χ-Y axis surface is not necessarily on the center axis line, but is displaced upward from the center line (support point side of the inner end surface of the bracket 2). P ₃ , P ₄
In point.

Therefore, the sensitivity can be further improved by arranging the sensing element 7 so that the sensing element 7 is radially displaced from the central axis of the shackle pin 3 toward the maximum stress generation region. However, since it is necessary to make a hole 6 for fitting the sensing element 7 in the shackle pin 3,
The shackle pin 3 cannot be arranged on the outer peripheral side of the shackle pin 3 because of its strength. Specifically, the amount of positional deviation in the radial direction is set to ½ or less of the axial radius of the shackle pin 3.

Next, the change in the load / gain depending on the fitting state of the sensor body 70 (see FIG. 13) including the sensing element 7 and the shackle pin 3 will be examined. As shown in FIG. When the margin is +0.025 mm (tight) and when the tightening margin is -0.025 (loose), the sensitivity is more than twice as high as the former, and the output sensitivity is further improved by the interference fit. It was confirmed that it would improve.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, and are merely illustrative examples. It's just FIG. 5 shows a schematic structure of a suspension portion of a heavy-duty truck to which the present invention is applied. In this vehicle, a front wheel single shaft 10 and a rear wheel double shaft 20 are provided.
And the leaf springs 11 are used as suspensions.

The leaf spring 11 on the front shaft 10 side
In the center of the, along with a shock absorber (not shown),
An axle 12 (axle case) is attached. Further, as shown in FIG. 6, a shackle pin 3 is fitted to an eye portion 11A on one end side of the leaf spring 11 via a bush 13, and is fixed to the carrier frame 1 via the shackle pin 3. It is supported by the bracket 2. On the other hand, the other end side 11 of the leaf spring 11
B is supported by a bracket 2 fixed to the luggage carrier frame 1 via a substantially inverted Y-shaped shackle link 14. Since such a configuration is publicly known, detailed description thereof will be omitted.

Further, as shown in FIG. 6, a groove 3 is formed in the shackle pin 3 on the peripheral surface of the bracket 2 fitting portion of the shackle pin 3.
a is provided, and the pin fixing bolt 5 is inserted into the groove 3a through the hole on the side surface of the bracket 2 and tightened so that the shackle pin 3 does not rotate and move axially with respect to the bracket 2. It is fixed. Note that the sensor body 70 (see FIG. 13) including the sensing element 7 and the shackle pin 3 are both fitted with a tightening margin of +0.02.
It is performed by an interference fit of 5 mm (tight).

FIG. 13 shows the structure of the magnetostrictive sensor 80. As shown in FIG. 13 (A), the rectangular thin plate 10 made of a ferromagnetic material such as permalloy is provided at the center of the plate 4 in the cross direction.
4 small holes 79
Two imaginary lines M in a direction that is turned to the left or right by 45 ° with respect to the winding direction of the exciting coil 71 from the intersection connecting the centers in a cross shape.
And a pair of notches 75 are provided by symmetrically notching the upper edge and the lower edge of the thin plate 80 sandwiched between the two virtual lines M in a flat U-shape. When the cutout 75 is sandwiched between two imaginary lines M of 45 ° turning passing through the intersection, and the edge length of the thin plate 80 is L, the cutout 75 width L ₀ is the following formula 1). And notch 75
The tangent line and the imaginary line M parallel to the imaginary line M passing through the corners of the bottom surface
Notch 75 so that the distance m between
May be provided, and the shape thereof is not particularly limited. L ₀ ≦ L ... 1) m> 0, preferably M ≧ 1 mm ... 2) Then, coil wires are inserted in the four holes 79 in a cross shape in the vertical and horizontal directions so as to cross each other at right angles, and the exciting coil 71 is wound.
The output coil 72 is arranged to be positioned at 45 ° with respect to the force acting direction. Then, the sensing element 7 configured as described above is housed in the sensor holding space 76 in the tubular holder 77 as shown in FIG. 13B, and the tubular holder 77 and the thin plate 80 are spot-welded. Although it is fixed, the fixed position p is set at the intersection of the two virtual lines M and the edge line of the thin plate 80 or in the vicinity thereof.

A hollow hole 6 is bored from the end face of the shackle pin 3 along the central axis direction, and a magnetostrictive sensing element 7 is fitted and mounted inside the hole 6. The sensing element 7 is arranged at the fitting position shown in FIG. That is, FIG. 1 shows a bracket 2 and a leaf spring 11 via a shackle pin 3.
Fig. 1 (A) shows a schematic view of a state in which are joined together. Fig. 1 (A) shows a central side from the inner end surface of the bracket 2 corresponding to the maximum stress region of the shear stress diagram on the central axis of the shackle pin 3 shown in Fig. 2. One sensor body 70 is provided so that the detection center of the sensing element 7 is located at the shifted point P ₁ .

Further, in FIG. 1B, the detection center of the sensing element 7 is located at a point P ₂ displaced outward from the inner end surface of the bracket 2 corresponding to the maximum stress region of the shear stress diagram shown in FIG. Thus, one sensor body 70 is provided for each. Further, FIG. 1 (C) shows P shifted to both sides from the inner end surface of the bracket 2 corresponding to the maximum stress region of the shear stress diagram shown in FIG.
_One sensor body 70 is provided at each of points ₁ and P ₂ so that the detection center of the sensing element 7 is located.

Next, the arrangement position of the sensing element 7 on the vehicle rear wheel side 20 will be described. Since the rear wheel of this embodiment is a two-wheeled vehicle, as shown in FIG.
As shown in FIG. 7, the leaf spring 11 has a trunnion shaft 51 fitted and supported by a trunnion bracket 52 fixed to the carrier frame 1, as shown in FIG. 7. The leaf spring 11 is attached to the upper surface side of the end side through the spring seat 54 and the fixing jig 53. That is, the trunnion shaft 51 has a central portion curved upward in a U shape, and both sides thereof are horizontally extended so that the trunnion bracket 5 is formed.
2 and the mounting portion 51a of the leaf spring 11.

The trunnion bracket 52 is formed by expanding in an eight shape from the lower surface side of the luggage carrier frame 1. The horizontal shaft portion of the trunnion shaft 51 is fitted to the lower portion of the bracket 52 and protrudes from the bracket 52. As described above, the central portion of the leaf spring 11 is attached to the end of the trunnion shaft 51 horizontal shaft portion via the spring seat 54 and the fixing jig 53. The bracket 52
The trunnion shaft 51 is also fitted by interference fit.

In the trunnion shaft 51, a hollow hole 6 is bored from the end face of the trunnion shaft 51 along the central axis direction, and a magnetostrictive sensor body 70 is fitted and mounted in the hole 6. Has been done. The sensor body 70 including the sensing element 7 is arranged at the position shown in FIG.

That is, FIG. 8 is a schematic view showing a state in which the trunnion shaft 51 is coupled with the trunnion bracket 52 and the leaf spring 11, and FIG. 8A shows shearing on the central axis of the trunnion shaft 51 shown in FIG. The sensor bodies 70 are arranged one by one so that the detection center of the sensing element 7 is located at a point P ₁ deviated from the inner end surface of the bracket 2 toward the center corresponding to the maximum stress region of the stress diagram. I have set up. Further, FIG. 8B shows that the detection center of the sensing element 7 is located at a point P ₂ displaced outward from the inner end surface of the bracket 2 corresponding to the maximum stress region of the shear stress diagram shown in FIG. The sensor bodies 70 are arranged one by one. Further, in FIG. 8C, the detection center of the sensing element 7 is located at points P ₁ and P ₂ which are displaced to both sides from the inner end surface of the bracket 2 corresponding to the maximum stress region of the shear stress diagram shown in FIG. 9. Thus, the sensor bodies 70 are arranged one by one. The fitting margin of the sensor body 70 and the trunnion shaft 51 is +0.025 m in both cases.
It is performed by an interference fit of m (tight).

Next, the process of measuring the load using the output signal of the sensing element 7 arranged as described above will be described with reference to FIG. In this embodiment, in order to secure gain stability and accuracy, FIG.
A measuring device based on the configuration of (C) will be described. First, on the front wheel side, the shackle pin 3 having the sensing elements 7 on each of the right wheel and the left wheel is arranged on both ends of the shackle pin 3.
X {2 x (P ₁ , P ₂ )} total of 8 sensing elements 7 are measured on both left and right wheel sides, and a pair of (P ₁ , P ₂ ) output signals at each sensing position in the computing unit 41. (Ρ ₁ −
ρ ₂ ) and gain values ρ _RR , ρ _RL , ρ _LL , and ρ _LR at each sensing position are summed to obtain a gain output F ρ corresponding to the front axle load.

Next, on the rear wheel side as well, a total of four {2 × (P ₁ , P ₂ )} are provided at both ends of the trunnion shaft in which the sensing elements 7 are provided for the right wheel and the left wheel, respectively. The left and right wheels of the sensing element 7 are measured, and the calculator 43
In each sensing position, take a pair (P ₁ , P ₂ ) output signal difference (ρ ₁ −ρ ₂ ), take the sum of gain values ρ _R and ρ _L at each sensing position, and respond to the rear axle load. Gain output Bρ is obtained.

Then, after the gain outputs Fρ and Bρ are summed by the calculator 44, a value obtained by converting the (Fρ + Bρ) according to the load is obtained as the sprung load of the vehicle. The unsprung load measured in advance is added to this, and the vehicle weight is displayed on the display unit 45. When the load is measured, the display on the display unit may be set to "0" when the load is empty, and then the change in the indicator 45 after the load is loaded may be read.

[0040]

As described above, according to the present invention, the shear strain (stress) distribution when the shackle pin 3 is subjected to a load is obtained by the finite element method analysis CAE, and the shear strain is calculated based on the cut distribution. Since the sensing element 7 for efficiently measuring (stress) is arranged at the most suitable position, sensitivity,
Both accuracy and stability can obtain a sufficient gain value for shear strain (stress) measurement. Moreover, in the present invention, the sensing element 7 is disposed at a position corresponding to the maximum stress region of the shear stress diagram on the axis by shifting a predetermined distance in the axial direction from the band-shaped void position C-C. Since it is sufficient to increase the gain, it is possible to easily increase the gain without changing existing parts or the like. Furthermore, the placement position of the sensing element 7 with respect to the central axis of the shackle pin 3
The gain can be further increased by arranging the positions on the maximum stress generation region side so as to be displaced in the radial direction. The sensing elements 7 are arranged on both left and right sides of the band-shaped void position C-C,
It is possible to further increase the gain by taking the difference between the output signals of the respective sensing elements 7. Further, since all the sensing elements 7 are arranged in the maximum stress region, even if the mounting position of the element 7 is slightly deviated, the gain is not sensitively changed and is stable.

[Brief description of drawings]

1 (A), (B) and (C) are schematic views showing arrangement positions of sensing elements according to an embodiment of the present invention.

FIG. 2 shows a shear stress diagram on the central axis of the shackle pin.

FIG. 3 is a stress distribution diagram showing, by arrows, a compressive stress and a tensile stress in a Χ-Y axis surface on which the shackle pin receives a load.

FIG. 4 is a graph showing a change in load / gain depending on a fitting state of the bracket and the shackle pin, (A).
If the tightening margin is +0.025 mm (tight), (B)
Shows the case where the tightening margin is -0.025 (loose).

FIG. 5 shows a schematic configuration of a suspension portion of a large truck to which the present invention is applied.

FIG. 6 is an enlarged cross-sectional view of the front end portion of the leaf spring on the front wheel side, showing a state where the bracket and the shackle pin are fitted together.

FIG. 7 shows a fitted state of a trunnion shaft supporting a leaf spring on the rear wheel side and a trunnion shaft.

8A, 8B, and 8C are schematic diagrams showing arrangement positions of sensing elements fitted and mounted in a trunnion shaft.

FIG. 9 is a shear stress diagram on the central axis of the trunnion shaft.

FIG. 10 is a process diagram for measuring a load using output signals of the sensing elements arranged as shown in FIGS. 1C and 8C.

FIG. 11 is a schematic view showing the arrangement position of a sensing element according to the related art.

FIG. 12 is a graph showing the relationship between the load / gain output of the sensing element arranged at the point P _{1 of the} present invention and the sensing element arranged at the point P _{0 of} the prior art.

[Explanation of symbols]

1 a vehicle body (loading platform) Frame 2 bracket 3 shackle pin 6 holes 7 sensing element 11 leaf suspension C-C band gap positions _{P 1, P 2, P 3} , P 4 shear stress diagram

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[Procedure amendment]

[Submission date] February 1, 1996

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of drawings]

1 (A), (B) and (C) are schematic views showing arrangement positions of sensing elements according to an embodiment of the present invention.

FIG. 2 shows a shear stress diagram on the central axis of the shackle pin.

FIG. 3 is a stress distribution diagram showing, by arrows, a compressive stress and a tensile stress in an XY axis plane on which the shackle pin receives a load.

FIG. 4 is a graph showing a change in load / gain depending on a fitting state of the bracket and the shackle pin, (A).
If the tightening margin is +0.025 mm (tight), (B)
Shows the case where the tightening margin is -0.025 (loose).

FIG. 5 shows a schematic configuration of a suspension portion of a large truck to which the present invention is applied.

FIG. 6 is an enlarged cross-sectional view of the front end portion of the leaf spring on the front wheel side, showing a state where the bracket and the shackle pin are fitted together.

FIG. 7 is a view showing a fitted bear having a trunnion bracket that supports a leaf spring on the rear wheel side and a trunnion shaft.

8A, 8B, and 8C are schematic diagrams showing arrangement positions of sensing elements fitted and mounted in a trunnion shaft.

FIG. 9 is a shear stress diagram on the central axis of the trunnion shaft.

FIG. 10 is a process diagram for measuring a load using output signals of the sensing elements arranged as shown in FIGS. 1C and 8C.

FIG. 11 is a schematic view showing the arrangement position of a sensing element according to the related art.

FIG. 12 is a graph showing the relationship between the load / gain output of the sensing element arranged at the point P _{1 of the} present invention and the sensing element arranged at the point P _{O of} the conventional technique.

FIG. 13 shows a structure of a magnetostrictive sensor used in FIG. 6, (A) is a sensing element, and (B) is a sectional view in which the sensing element is incorporated in a holder.

[Description of Reference Numerals] 1 vehicle (loading platform) Frame 2 bracket 3 shackle pin 6 holes 7 sensing element 11 leaf suspension C-C band gap positions _{P 1, P 2, P 3} , P 4 shear stress diagram

Claims (5)

[Claims] 1. A shackle pin that connects a bracket attached to a vehicle body frame and a leaf spring side of a vehicle suspension with a hole formed in the shackle pin along an axial direction, and a sensing element for detecting strain is fitted in the hole. In a vehicle or / and a loaded weight measuring device that is arranged in a combined manner, the detection center of the sensing element is located at a predetermined distance in the axial direction from a band-shaped air gap position (hereinafter referred to as a band-shaped air gap position) between the bracket end surface and the leaf spring side end surface. Vehicles and / or loaded weight measurement characterized by arranging them in a staggered manner and arranging the sensing element at a position substantially corresponding to the maximum stress area of the shear stress diagram of the shackle pin on the axis of the hole apparatus 2. The vehicle according to claim 1, wherein the sensing element is disposed such that the position of the sensing element is displaced in the radial direction toward the maximum stress generation region with respect to the central axis of the shackle pin. And load weight measuring device 3. The vehicle or / and load weight measuring device according to claim 2, wherein the amount of positional deviation in the radial direction is 1/2 or less of an axial radius of the shackle pin. 4. The detection centers of the sensing elements are respectively positioned at two positions on the left and right sides in the axial direction of the band-shaped void position and substantially corresponding to the maximum stress region,
The vehicle or / and the loaded weight measuring apparatus according to claim 1, wherein the gain is increased by obtaining a difference between output signals of the respective sensing elements. 5. The vehicle or / and the loaded weight measuring device according to claim 1, wherein the sensor body including the sensing element and the shackle pin are fitted by an interference fit.