JP2001343277A - Load measuring apparatus for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a load measuring apparatus for a vehicle which has little display error and is excellent in precision without deteriorating comfortable ride on a vehicle. SOLUTION: This load measuring apparatus for a vehicle is equipped with a load sensor installed in a part of a member to be loaded in a vehicle. The sensor is connected with an accel, has a leaf spring 1 constituted of at least two stacked plate springs and a leaf spring retaining member for retaining the leaf spring 1 on a loading flame 21, and detects a load applied to a vehicle. The plate spring 1A, 1B which face each other and constitute the leaf spring 1 are stacked in such a manner that facing surfaces in the vicinity of at least one end portions of the respective plate springs turn to a load concentration part in the case of sliding corresponding to the load, and facing surfaces except the load concentration part turn to a state of non-contact.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load measuring device for a vehicle, and more particularly to a load measuring device for a vehicle having improved accuracy of measuring a loaded load on a vehicle having a leaf spring composed of a plurality of leaf springs stacked one on another. About.

[0002]

2. Description of the Related Art Conventionally, vehicle load measurement is mainly performed on large vehicles such as trucks. This is because overloading of trucks etc. not only impairs the driving operability of the vehicle itself and causes traffic accidents,
This is to prevent the pain of the vehicle and the road surface and to prevent them.

[0003] By the way, in a large vehicle such as the above-mentioned truck, a certain degree of strength is required as a spring member for absorbing shock from the road surface and improving ride comfort. Is connected to an axle that connects the wheels.
In addition, a load sensor for measuring a loaded load on the vehicle is provided on a part of a bracket, an axle, or the like that connects the leaf spring to the carrier frame. However, the leaf spring as described above sometimes causes an error in the indication of the load measurement due to the hysteresis difference caused by the sliding friction between the leaf springs.

[0004] A conventional example and its accompanying problems will be described below with reference to FIGS. 5 and 6. FIG. 5 (A)
1 is a schematic diagram showing the overall configuration of the present invention and a conventional vehicle load measuring device described later. FIG. 5B is a schematic perspective view showing an example in which a strain sensor is installed on a part of an axle in the present invention and a conventional vehicle load measuring device. FIG. 6 (A)
FIG. 2 is a side view showing a leaf spring and related parts of a conventional vehicle load measuring device. FIG. 6B is an explanatory diagram showing the sliding operation at the end of the leaf spring in FIG. 6A.

As shown in the schematic diagram of FIG. 5A, a pair of brackets 5A and 5B for a rear wheel are fixed to a bed frame 21 of a truck. The leaf spring 1 constituting the rear wheel suspension has a front end connected to a bracket 5A via a shackle pin 4A, a rear end connected to a shackle 8 via a shackle pin 4B, and furthermore, the shackle 8 It is connected to bracket 5B via pin 4C. An axle 26 connecting the axles of the left and right wheels 22 is fixed to the center of the leaf spring 1 by U-shaped bolts 7B and 7C.

A load sensor 6 is provided on a part of the bracket 5A. This load sensor 6 is, for example,
Bracket 5A that changes according to the loading load on the vehicle
Detects and outputs compression force or strain to A controller 24 is connected to the load sensor 6 via an amplifier 23, and a display device 25 is connected to the controller 24. The amplifier 23 amplifies the load detection output from the load sensor 6. The controller 24 includes an amplifier 23
The load value is calculated by calculating the amplified output value. In addition, the display device 25 notifies the driver and the loader of the load calculated by the controller 24 by display.

In FIG. 5A, two leaf springs are included in the leaf spring 1 for the sake of simplicity. However, actually, a larger number of leaf springs are stacked. It is configured in a hurry. Also, for the sake of simplicity, the description assumes the rear wheel as a representative.

As shown in the schematic perspective view of FIG. 5B, in this example, a pair of strain sensors 6B are provided on a part of the axle 26 instead of the load sensor 6 of FIG. 5A. . In this example, the strain sensor 6B detects the strain of the axle 26 according to the load, and outputs the detected output via the amplifier 23, the controller 24, and the display device 25 equivalent to those shown in FIG. To inform.

[0009]

However, when a load is measured in a vehicle using a leaf spring in which a plurality of leaf springs are superimposed as described above, when a load is measured, a sliding friction generated between the leaf springs according to the load is measured. Due to the hysteresis difference, there may be a case where an instruction error of the load measurement is generated. This will be described with reference to FIGS.

FIG. 6A is a side view showing a leaf spring of a conventional vehicle load measuring device and its related parts. FIG. 6B is an explanatory diagram showing the sliding operation at the end of the leaf spring in FIG. 6A. Since FIG. 6B is for describing the sliding operation, the cylindrical portion through which the shackle pin shown in FIG. 6A penetrates is omitted. Further, reference numerals and symbols given in FIG. 6B indicate portions equivalent to those shown in FIG.

As shown in the side view of FIG. 6A, two leaf springs 1A and 1E constituting a leaf spring are fixed at a substantially central portion in a longitudinal direction by a bolt 7A.
Both ends of the leaf spring 1A are machined into a cylindrical shape, and the shackle pins 4A and 4B pass through this portion. When the shackle pins 4A and 4B are pierced, the leaf spring is connected to the bracket 5A and the shackle 8 drawn by imaginary lines.

A load sensor 6 drawn by an imaginary line is provided above a portion of the bracket 5A where the shackle pin 4A penetrates. On the other hand, a shackle pin 4C passes through a connection hole near the upper end of the shackle 8, and the shackle 8 is connected to a bracket 5B drawn by imaginary lines. The brackets 5A and 5B are fixed to the carrier frame 21 of a vehicle such as a truck as described above.

The leaf spring as described above is used in FIG.
As shown in the explanatory diagram of (B), when the state of the unloaded leaf spring shown by the imaginary line changes to the load state shown by the solid line according to the loaded load, that is, when the leaf spring is bent by the distance D, The opposing surfaces of the springs 1A and 1E rub against each other in contact with each other, and slide by a distance S3.

By the way, a leaf spring formed by stacking a plurality of leaf springs usually has a hysteresis characteristic due to sliding friction between the leaf springs. Due to the hysteresis difference based on the hysteresis characteristic, for example, an error in the load amount is generated between the time of loading and the time of unloading, despite the same load amount. Such pointing errors are:
The greater the frictional force between the plurality of leaf springs, the more the hysteresis difference becomes significant, and therefore the greater the difference.

In the conventional leaf spring having the above-mentioned structure, the sliding friction force is increased since the opposing leaf springs are almost in contact with each other. For this reason, the hysteresis difference also increases, and the error in indicating the load amount increases. More specifically, as shown in FIG. 5A, the leaf spring is usually fixed at both ends, and the load W is
F1 + F2 is dispersedly applied to the both ends of the leaf spring 1. However, in the leaf spring having the above-described configuration, the ratio between F1 and F2 is likely to fluctuate irregularly, and the indication error is further increased. there were.

Further, as shown in FIG. 5 (B), a strain sensor is provided on a part of the axle, and the amount of strain by this sensor is converted into a load to be applied to a vehicle load measuring device. 5 due to the change in the F1 / F2 ratio.
There is a problem that the indication error eventually increases because the twist is irregularly applied in the direction indicated by the arrow (B) and the distortion amount also changes irregularly.

In order to solve the above-mentioned problem, there is an idea that a lubricant or the like is applied between the leaf springs to reduce the frictional force between the leaf springs and reduce the hysteresis difference. And the ride comfort of the vehicle deteriorates.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a highly accurate load measuring device for a vehicle without deteriorating the riding comfort of the vehicle and reducing the pointing error.

[0019]

According to the present invention, there is provided a load measuring apparatus for a vehicle, comprising:
As shown in (A), a load is applied to a vehicle having a leaf spring 1 connected to an axle and including at least two stacked leaf springs and a leaf spring support member for supporting the leaf spring 1 on a carrier frame 21. In a vehicular load measuring device provided with a load sensor provided on a part of a member to be loaded in the vehicle for detecting a load, opposed leaf springs 1A and 1B constituting the leaf spring 1 are respectively provided. At least one of the opposing surfaces near one end becomes a load concentrated portion when sliding in accordance with the load, and the opposing surfaces other than the load concentrated portion are stacked so as to be in a non-contact state. It is characterized by.

According to the first aspect of the present invention, the opposed leaf springs 1A and 1B constituting the leaf spring 1 have their facing surfaces near at least one end thereof slid according to the applied load. It is stacked so that it becomes a load load concentrated part at the time. Then, the opposing surfaces other than the load concentrated portion are in a non-contact state. Therefore, when the leaf spring slides due to the applied load, the sliding friction between the opposing leaf springs 1A and 1B can be greatly reduced, and the hysteresis difference is accordingly reduced. . Further, by making the opposing surfaces other than the load concentrated portion in a non-contact state, the sliding amount with respect to the bending of the leaf springs 1A and 1B is apparent as compared with FIG. 1B and FIG. 6B. Becomes larger.

In order to solve the above-mentioned problems, the vehicle load measuring device according to the second aspect is shown in FIGS.
As shown in (B) to (D), a leaf spring 1 connected to an axle and composed of at least two stacked leaf springs and a leaf spring supporting member for supporting the leaf spring 1 on a carrier frame 21 are provided. In a vehicle load measuring device provided with a load sensor provided on a part of a member to be loaded in the vehicle, which detects a load applied to the vehicle, opposed leaf springs constituting the leaf spring 1 superimposed on each other 1A, 1C, on the inner surface of one of the leaf springs 1C, the load load concentrating portion 11 (12A and 12B, which is a contact point or a contact line when the leaf springs 1A, 1C slide according to the applied load. Or 13) is provided.

According to the second aspect of the present invention, a contact point or a contact line at the time of sliding is provided on the inner surface of one of the opposed leaf springs 1A and 1C constituting the leaf spring 1. The load load concentrating portion 11 (12A and 12B or 13) is provided. Further, with this configuration, portions other than the load concentrated portion are brought into a non-contact state during sliding. Therefore, when the leaf spring slides, sliding friction occurs only between the contact point or the contact line and the facing surface. That is,
Since both leaf springs 1A and 1C are slid by point contact or line contact, sliding friction between leaf springs 1A and 1C can be greatly reduced, and the hysteresis difference is reduced accordingly. In addition, by sliding by point contact or line contact, the load point is determined, the trajectory during sliding is specified, and the hysteresis difference is further reduced. Further, by making the opposing surfaces other than the load load concentrated portion in a non-contact state, as apparent from comparison between FIG. 2 (B) and FIG. 6 (B), sliding against the bending of the leaf springs 1A and 1C is apparent. The momentum increases.

A vehicle load measuring device according to a third aspect of the present invention, which has been made to solve the above-mentioned problem, has a structure shown in FIGS.
As shown in (A) and FIG. 5 (A), in the vehicle load measuring device according to claim 1, the load sensor is provided on a part of the leaf spring support member 5 </ b> A. It is characterized by.

According to the third aspect of the present invention, the load sensor is provided on a part of the leaf spring support member 5A. By providing a load sensor on a part of the member 5A, a larger load variation can be obtained.

A vehicle load measuring device according to a fourth aspect of the present invention has been developed to solve the above problems.
As shown in (A) and FIG. 5 (B), in the vehicle load measuring device according to claim 1, the load sensor is provided on a part of the axle 26. I do.

According to the fourth aspect of the invention, the load sensor is provided on a part of the axle 26. Axle 2
By providing a load sensor in a part of 6, a larger load variation can be obtained.

A vehicle load measuring device according to a fifth aspect of the present invention has been made to solve the above problems.
As shown in (B), in the load measuring device for a vehicle according to any one of claims 1 to 4, the opposing surfaces of the opposing leaf springs of the leaf spring 1 other than the load load concentrated portion are in a non-contact state. A spacer 2 is provided between the opposed leaf springs.

According to the fifth aspect of the present invention, the spacer 2 is provided between the plate springs facing each other. Spacer 2
Are arranged so that the opposing surfaces of the opposing leaf springs constituting the leaf spring 1 other than the load load concentrated portion are in a non-contact state. By providing the spacer 2 between both leaf springs,
The non-contact portion can be more easily and reliably formed between the leaf springs.

A vehicle load measuring device according to a sixth aspect of the present invention, which has been made to solve the above-mentioned problems, has a structure shown in FIGS.
As shown in (A), in the vehicle load measuring device according to claim 1, the vicinity of an end of one of the opposed leaf springs 1A and 1C constituting the leaf spring 1 is bent. The inner surface near the bent end portion is the load concentrated portion.

According to the sixth aspect of the present invention, one of the opposed leaf springs 1A and 1C constituting the leaf spring 1 is bent near the end of one leaf spring 1C.
The inner surface near the bent end serves as a sliding surface. In this way, a bending surface is formed to form a sliding surface, and portions other than this portion are brought into a non-contact state. Therefore, when the leaf spring slides, the contact area between the leaf springs 1A and 1C is smaller than that in the related art, so that the sliding friction between the leaf springs 1A and 1C can be reduced accordingly. Further, the frictional energy is increased by the bent sliding surface, and the two leaf springs 1 are more stably formed.
A and 1C come to slide.

[0031]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a side view showing a first embodiment of a vehicle load measuring device according to the present invention. FIG.
FIG. 2B is an explanatory view showing a sliding operation at the end of the leaf spring in FIG. Note that the leaf springs constituting the leaf springs are configured by laminating more than two leaf springs, but here, two leaf springs will be described for simplicity.

As shown in the side view of FIG. 1A, two opposing leaf springs 1A and 1B constituting a leaf spring.
Are overlapped such that the inner surfaces near the respective end portions are in contact with each other and the respective central portions in the longitudinal direction are not in contact with each other. For example, a metal spacer 2 is sandwiched between the central portions of the two leaf springs 1A and 1B in order to make the central portion in a non-contact state.
A gap 3 is formed between both leaf springs 1A and 1B. Although the two leaf springs 1A and 1B and the spacer 2 are fixed by bolts 7A in this figure, in practice, the two leaf springs 1A and 1B are fixed around U-shaped bolts so as to surround the vicinity of the center thereof. Have been.

Both ends of the leaf spring 1A are machined into a shape that is wound into a cylindrical shape, and the shackle pins 4A and 4B are penetrated through these portions. When the shackle pins 4A and 4B penetrate, the leaf spring 1 is connected to the bracket 5A and the shackle 8 drawn by imaginary lines.

A part of the bracket 5A, in this embodiment, above the place where the shackle pin 4A is penetrated,
A load sensor 6 drawn by an imaginary line is provided. The load sensor 6 detects and outputs, for example, the compressive force or distortion of the bracket 5A that changes according to the load on the vehicle. And the detection output from the load sensor 6 is
For example, the amplifier 23 as shown in FIG.
The load is notified via the controller 24 and the display device 25. On the other hand, a shackle pin 4C passes through a connection hole near the upper end of the shackle 8, and the shackle 8 is connected to a bracket 5B drawn by imaginary lines. The brackets 5A and 5B are fixed to a carrier frame 21 of a vehicle such as a truck as shown in FIG.

Since the bracket 5A is directly affected by the load applied to the leaf spring 1 for supporting the leaf spring 1, a larger load variation can be obtained by providing the load sensor 6 on a part of the bracket 5A. be able to. As a result, the applied load can be measured more accurately. The bracket 5A corresponds to a leaf spring support member in claims 1 to 6.

Note that, instead of the load sensor 6 of FIG. 1B, a pair of strain sensors 6B are provided on a part of the axle 26 as shown in FIG. The distortion of the axle 26 according to the loaded load may be detected, and the detected output may be notified through the amplifier 23, the controller 24, and the display device 25 equivalent to those shown in FIG.

Since the axle 26 is normally connected to a leaf spring and is greatly affected by the load applied to the leaf spring, the strain sensors 6A and 6B are provided as load sensors on a part of the axle 26, so that
A larger load variation can be obtained. As a result,
The applied load can be measured more accurately.

In the explanatory view showing the sliding operation of FIG. 1B, the imaginary line indicates the state of the leaf spring with no load. The solid line shows the state of the leaf spring when there is a load. FIG. 1B is a diagram for explaining the sliding operation.
The cylindrical portion through which the shackle pin shown in (A) is penetrated is omitted. Reference numerals and reference numerals given in this figure indicate portions equivalent to those shown in FIG.

As shown in FIG. 1B, the leaf spring as shown in FIG. 1A changes from a state of a no-load leaf spring shown by an imaginary line to a load state shown by a solid line according to the loaded load. When it changes, that is, when the leaf spring bends by the distance D, the opposing contact portions of the leaf springs 1A and 1B rub against each other and slide by the distance S1 (> S3). Note that the distance D shown here is the same amount as that shown in FIG.

As described above, according to the first embodiment, the opposed leaf springs 1A, 1A constituting the leaf spring 1
The facing surface near the end of B is made to be a load concentrated portion, and the facing surface other than this portion is in a non-contact state. Therefore, when the leaf spring slides due to the applied load, the sliding friction between the opposed leaf springs 1A and 1B can be greatly reduced. Since the hysteresis difference is also reduced by the reduced sliding friction, it is possible to reduce, for example, an error in indicating the load amount between when loading and unloading.

Further, by making the opposing surfaces other than the load load concentrated portion in a non-contact state, the bending of the leaf springs 1A and 1B can be clearly understood by comparing FIG. 1 (B) and FIG. 6 (B). (See distance D) The sliding amount becomes large (S1> S
3). By increasing the sliding amount in this manner, a large frictional energy of the entire leaf spring can be secured. Therefore, the shock absorbing force of the leaf spring 1 can be secured, and the riding comfort of the vehicle does not deteriorate.

As a result, according to the first embodiment, a highly accurate vehicle load measuring device can be obtained without deteriorating the riding comfort of the vehicle.

Further, according to the first embodiment, the spacer 2 is provided between the plate springs facing each other. The spacer 2 is arranged so that the opposing surfaces of the opposing leaf springs of the leaf spring 1 other than the load concentrated portions are in a non-contact state. As described above, by providing the spacer 2 between the two leaf springs, a non-contact portion can be more easily and reliably formed between the leaf springs. That is, at the time of assembling the leaf springs, it is only necessary to overlap the leaf springs so as to sandwich the spacer 2 between the two springs.

Next, a second embodiment of the vehicle load measuring device according to the present invention will be described with reference to FIGS. 2 (A) and 2 (B). FIG. 2A is a side view showing a second embodiment of the vehicle load measuring device of the present invention. FIG. 2 (B) is FIG.
It is explanatory drawing which shows the sliding operation | movement in the leaf spring end part of (A).

As shown in the side view of FIG. 2A, two opposing leaf springs 1A and 1C constituting a leaf spring.
A bent portion B is formed near the end of one leaf spring 1C by bending. A sliding projection or the like may be provided on the inner surface side of the bent portion B as described later with reference to FIGS. The inner surface of the bent portion B of the leaf spring 1C is in contact with the inner surface of the opposing leaf spring 1A, and is overlapped so that the respective longitudinal central portions are not in contact with each other. When the sliding protrusion is provided, the sliding protrusion contacts the inner surface of the opposing leaf spring 1A and is overlapped so that the central portions in the longitudinal direction are not in contact with each other. In order to make the central portion in a non-contact state, as in the first embodiment, for example, the central portion of the two leaf springs 1A and 1C has, for example,
A gap 3 is formed between the two leaf springs 1A and 1C with a metal spacer 2 interposed therebetween. Both leaf springs 1A and 1
C and the spacer 2 are fixed by bolts 7A in this figure, but actually, both leaf springs 1A and 1B
Are fixed by U-shaped bolts or the like so as to surround the vicinity of the center thereof.

The processing of forming the both ends of the leaf spring 1A in the second embodiment as if it were wound into a cylindrical shape, and the connection of the leaf spring to the carrier frame using this, are described in the above-mentioned drawings. The description is omitted here because it is the same as that described in 1 (A). The reference numerals and symbols used for them are the same as those described with reference to FIG. Also, as described in the first embodiment, FIG.
As shown in FIG. 5B, a pair of strain sensors 6B are provided in a part of the axle 26 in place of the load sensor 6 of FIG. The distortion may be detected, and this detection output may be notified of the loaded load via the amplifier 23, the controller 24, and the display device 25 equivalent to those shown in FIG.

In the explanatory view showing the sliding operation of FIG. 2B, an imaginary line indicates a state of a leaf spring with no load. The solid line shows the state of the leaf spring when there is a load. Since FIG. 2B is for explaining the sliding operation, the cylindrical portions at both ends of the leaf spring through which the shackle pin passes are omitted. In addition, reference numerals and symbols given in this figure indicate parts equivalent to those shown in FIG.

As shown in FIG. 2B, the leaf spring as shown in FIG. 2A changes from the state of the unloaded leaf spring shown by the imaginary line to the load state shown by the solid line according to the loaded load. When it changes, that is, when the leaf spring bends by the distance D, the contact surfaces (or points or lines) of the leaf springs 1A and 1C facing each other rub and move in contact with each other, and slide by the distance S2 (> S3). . Note that the distance D shown here is the same amount as that shown in FIG.

As described above, according to the second embodiment, similarly to the first embodiment, the opposing surfaces near the ends of the opposing leaf springs 1A and 1C constituting the leaf spring 1 are made to be the load load concentrated portions. However, the opposing surfaces other than this portion are in a non-contact state. Therefore, when the leaf spring slides due to the applied load, the sliding friction between the opposed leaf springs 1A and 1C can be greatly reduced. Since the hysteresis difference is also reduced by the reduced sliding friction, it is possible to reduce, for example, an error in indicating the load amount between when loading and unloading. In addition, the effect peculiar to the bent portion B and the sliding protrusion becomes apparent from the following description using FIGS. 3 (A) to 3 (D).

Further, by making the opposing surfaces other than the load load concentrated portion in a non-contact state, the bending of the leaf springs 1A and 1C is apparent as compared with FIG. 2 (B) and FIG. 6 (B). (See distance D) The sliding amount increases (S2> S
3). By increasing the sliding amount in this manner, a large frictional energy of the entire leaf spring can be secured. Therefore, the shock absorbing force of the leaf spring 1 can be secured, and the riding comfort of the vehicle does not deteriorate.

As a result, according to the second embodiment, a highly accurate vehicle load measuring device can be obtained without deteriorating the riding comfort of the vehicle.

The effect of the spacer 2 in the second embodiment is the same as that of the first embodiment.

FIGS. 3A to 3D are partial perspective views showing variations of the leaf spring end portion of FIG. 2A. FIG.
As shown in (A), the bent portion B is formed at both ends (only one end is representatively drawn in this drawing) of the leaf spring 1C as described above, and the inner surface of the bent portion B is formed. That is, the surface facing the opposing leaf spring 1A is the sliding surface.

As shown in FIG. 3A, the leaf spring 1C
Is bent around to form a sliding surface, and the other part is brought into a non-contact state. Therefore, when the leaf spring slides, the contact area between the leaf springs 1A and 1C is smaller than that in the related art, so that the sliding friction between the leaf springs 1A and 1C can be reduced accordingly. Since the hysteresis difference is also reduced by the reduced sliding friction, for example, it is possible to reduce the error in indicating the loading amount between when loading and unloading,
A highly accurate vehicle load measuring device can be obtained. Further, the bent sliding surface increases the frictional energy, and the two leaf springs 1A and 1C can slide more stably, so that the spring performance is improved and the ride comfort of the vehicle is not impaired. The effect of improving the load measurement accuracy is obtained.

In the example shown in FIG. 3B, a sliding projection 11 is formed at the center of the bent portion B on the inner surface side. 2
When the leaf springs 1A and 1C slide, the sliding protrusion 11 becomes a contact point and slides while making point contact with the opposing surface of the leaf spring 1A. In the example shown in FIG. 3C, a pair of sliding protrusions 12A and 12B are formed at the center on the inner surface side of the bent portion B. When the two leaf springs 1A and 1C slide, the sliding projections 12A and 12B slide on the opposing surfaces of the leaf spring 1A while making point contact. In the example shown in FIG. 3 (D), a rib-shaped sliding protrusion 13 is formed at the center on the inner surface side of the bent portion B. When the two leaf springs 1A and 1C slide, the sliding projections 13 make line contact with the leaf springs 1A.
Slide on the opposing surface of.

The sliding projections 11 and 1 as described above are used.
2A and 12B or 13 need not necessarily be provided together with the bent portion B, and may be provided in the vicinity without the bent portion B. The point is that the sliding protrusions 11 may be formed so as to be a load concentrated portion when sliding in accordance with the loaded load.

According to the example shown in FIGS. 3B to 3D, one leaf spring 1C constituting the leaf spring 1 is used.
Sliding projections 1 which serve as contact points or contact lines during sliding
1 (12A and 12B or 13) is provided, and the other parts are in a non-contact state. Therefore, when the leaf spring slides, the sliding protrusion 11 (12A and 12B or 13)
The sliding friction occurs between the contact point or the contact line due to the above and the opposing surface. That is, since both leaf springs 1A and 1C slide by point contact or line contact, the sliding friction between leaf springs 1A and 1C is greatly reduced as compared with the related art. In particular, in the example of the line contact shown in FIG. 3D, the sliding friction force is greatly reduced and slides stably, and in the example of the point contact shown in FIGS. 3B and 3C, the sliding friction force is larger. , And the hysteresis difference is greatly reduced accordingly. In addition, by coming to slide by point contact or line contact, the load point is determined and the trajectory at the time of sliding is specified,
This further reduces the hysteresis difference. Due to such a large decrease in the hysteresis difference, for example, an error in the indication of the amount of loading between loading and unloading can be further reduced. As a result, a more accurate vehicle load measuring device can be obtained. As shown in FIG. 2 (B), the sliding amount is larger than before, so that it is needless to say that a good ride comfort can be secured.

The sliding projections 11 (12A and 12A)
B or 13) corresponds to the load concentrated portion in claim 2.

FIG. 4 shows a third embodiment of the vehicle load measuring device according to the present invention.
It is a side view showing an embodiment. In the third embodiment shown in FIG. 4, one of the opposed leaf springs constituting the leaf spring has a tapered shape in which the thickness at the center portion is large and the thickness at both end portions is small. The leaf spring 1D is
The leaf spring 1 shown in FIGS. 1A and 2A, respectively.
It is used as a substitute for B or 1C. The configuration of the other parts is the same as that shown in FIGS. 1A and 2A, and a description thereof will not be repeated.

By using the leaf spring 1D having the tapered shape as described above as the leaf spring, the sliding friction of the entire leaf spring can be further reduced. That is, the leaf spring is usually formed by laminating about four or five leaf springs. By adopting the tapered leaf spring 1D, the number of leaf springs can be increased without deteriorating the riding comfort. Can be reduced. By reducing the number of leaf springs constituting the leaf spring, the sliding friction of the leaf spring as a whole due to the leaf spring can be reduced. As a result, the hysteresis difference becomes smaller and a highly accurate vehicle load measuring device can be obtained.

It should be noted that the leaf spring described above does not have to be a type in which both ends are fixed by brackets, and may be a type in which only one end is fixed. Further, the leaf spring may be of a type in which a central portion in the longitudinal direction is connected to a bracket, and both ends of the leaf spring are connected to axles, respectively. In short,
The present measuring device can be applied to a vehicle using a leaf spring composed of superposed leaf springs.
Further, the mounting position of the load sensor is not limited to the position described in the above embodiment, and may be any position as long as it is a part of the load-receiving member in the vehicle.

[0062]

As described above, according to the first aspect of the present invention, the opposing surfaces near the ends of the opposing leaf springs 1A and 1B constituting the leaf spring 1 are formed as the load concentrated portions. And the opposing surfaces other than this portion are in a non-contact state. Therefore, when the leaf spring slides due to the applied load, the sliding friction between the opposed leaf springs 1A and 1B can be greatly reduced. Since the hysteresis difference is also reduced by the reduced sliding friction, it is possible to reduce, for example, an error in indicating the load amount between when loading and unloading. Further, by making the opposing surfaces other than the load concentrated portion in a non-contact state, the sliding amount with respect to the bending of the leaf springs 1A and 1B is apparent as compared with FIG. 1B and FIG. 6B. Becomes larger (S1> S3). By increasing the sliding amount in this manner, a large frictional energy of the entire leaf spring can be secured. Therefore, leaf spring 1
The shock absorbing power of the vehicle can be secured, and the riding comfort of the vehicle is not deteriorated. As a result, according to the present invention, a highly accurate vehicle load measuring device can be obtained without deteriorating the riding comfort of the vehicle.

According to the second aspect of the present invention, the load load concentrating portion 11 (12A) serving as a contact point or contact line at the time of sliding is provided on the inner surface of one leaf spring 1C constituting the leaf spring 1.
And 12B or 13) are provided, and the other parts are in a non-contact state. Therefore, when the leaf spring slides, sliding friction occurs between the contact point or the contact line and the facing surface. That is, since both leaf springs 1A and 1C slide by point contact or line contact, the sliding friction between leaf springs 1A and 1C can be greatly reduced, and the hysteresis difference is reduced accordingly. In addition, by sliding by point contact or line contact, the load point is determined and the trajectory at the time of sliding is specified, thereby further reducing the hysteresis difference. Due to such a large decrease in the hysteresis difference, for example, an error in the indication of the amount of loading between loading and unloading can be further reduced. Further, the load concentration section 11 (12A and 12B or 1
The leaf spring 1A,
The sliding amount with respect to the deflection of 1C increases. By increasing the sliding amount in this manner, a large frictional energy of the entire leaf spring can be secured. Therefore, the shock absorbing force of the leaf spring 1 can be secured, and the riding comfort of the vehicle does not deteriorate. As a result, according to the present invention, a highly accurate vehicle load measuring device can be obtained without deteriorating the riding comfort of the vehicle.

According to the third aspect of the present invention, the load sensor is provided on a part of the leaf spring support member 5A. The leaf spring support member 5A is directly affected by the load applied to the leaf spring 1 to support the leaf spring 1. Therefore, by providing the load sensor on a part of this member, a larger load variation can be obtained, and the applied load can be measured more accurately. Since the support member 5A supports the leaf spring 1, it is also affected by the hysteresis characteristic. However, according to the first and second aspects of the invention, the influence of the hysteresis characteristic is greatly reduced. As a result, the measurement accuracy is relatively improved.

According to the fourth aspect of the invention, the load sensor is provided on a part of the axle 26. Axle 2
6 is normally connected to the leaf spring 1 and thus is greatly affected by the load applied to the leaf spring 1.
Therefore, by providing a load sensor on a part of the axle 26, a larger load variation can be obtained, so that the applied load can be measured more accurately. Axle 2
6 is connected to the leaf spring 1 and thus is also affected by its hysteresis characteristics. However, according to the first and second aspects of the present invention, the influence of the hysteresis characteristics is greatly reduced. Thus, the measurement accuracy is relatively improved.

According to the fifth aspect of the present invention, by providing the spacer 2 between the opposing leaf springs, a non-contact portion can be more easily and reliably formed between the leaf springs. That is, at the time of assembling the leaf springs, it is only necessary to overlap them so that the spacer 2 is sandwiched between the two springs, and the effects of the above-described claims 1 to 4 can be easily obtained.

According to the sixth aspect of the present invention, one of the opposed leaf springs 1A and 1C constituting the leaf spring 1 is bent near the end.
The inner surface near the bent end serves as a sliding surface. In this way, a bending surface is formed to form a sliding surface, and portions other than this portion are brought into a non-contact state. Therefore, when the leaf spring slides, the contact area between the leaf springs 1A and 1C is smaller than that in the related art, so that the sliding friction between the leaf springs 1A and 1C can be reduced accordingly. Since the hysteresis difference is also reduced by the reduced sliding friction, for example, it is possible to reduce the error in indicating the loading amount between when loading and unloading,
A highly accurate vehicle load measuring device can be obtained. Further, the bent sliding surface increases the frictional energy, and the two leaf springs 1A and 1C can slide more stably, so that the spring performance is improved and the ride comfort of the vehicle is not impaired. The effect of improving the load measurement accuracy is obtained.

[Brief description of the drawings]

FIG. 1A is a side view showing a first embodiment of a vehicle load measuring device according to the present invention. FIG. 1 (B) is FIG.
It is explanatory drawing which shows the sliding operation | movement in the leaf spring end part of (A).

FIG. 2A is a side view showing a second embodiment of the vehicle load measuring device according to the present invention. FIG. 2 (B) is FIG.
It is explanatory drawing which shows the sliding operation | movement in the leaf spring end part of (A).

3 (A) to 3 (D) are partial perspective views showing variations of the leaf spring end portion of FIG. 2 (A).

FIG. 4 is a side view showing a third embodiment of the vehicle load measuring device of the present invention.

FIG. 5A is a schematic diagram showing the overall configuration of the present invention and a conventional vehicle load measuring device. FIG. 5B is a schematic perspective view showing an example in which a strain sensor is installed on a part of an axle in the present invention and a conventional vehicle load measuring device.

FIG. 6A is a side view showing a leaf spring of a conventional vehicle load measuring device and its related parts. FIG.
FIG. 7B is an explanatory view showing a sliding operation at the end of the leaf spring in FIG.

[Explanation of symbols]

 1A, 1B Leaf spring 2 Spacer 3 Gap 4A, 4B Shackle pin 5A, 5B Bracket (leaf spring support member) 6 Load sensor 7A Bolt

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masayuki Terada 1500 Onjuku, Susono-shi, Shizuoka Prefecture Yazaki Sogyo Co., Ltd. F-term (reference) 3D001 AA00 BA56 CA03 DA01 EA41 ED05

Claims (6)

[Claims] Detecting a load applied to a vehicle having a leaf spring connected to an axle and including at least two stacked leaf springs and a leaf spring supporting member for supporting the leaf spring on a carrier frame. In a vehicle load measuring device provided with a load sensor provided on a part of a member to be loaded in a vehicle, the leaf springs constituting the leaf springs are:
The opposing surfaces near at least one end of each become a load concentrated portion when sliding in accordance with the load, and the opposing surfaces other than the load concentrated portion are stacked so as to be in a non-contact state. A vehicle load measuring device. Detecting a load applied to a vehicle having a leaf spring connected to an axle and including at least two stacked leaf springs and a leaf spring supporting member for supporting the leaf spring on a carrier frame. In a vehicle load measuring device provided with a load sensor provided on a part of a member to be loaded in a vehicle, an inner surface of one of the opposed leaf springs which are superimposed and constitute the leaf spring is provided. A load load concentrating portion provided as a contact point or a contact line when the leaf spring slides according to a load. 3. The vehicle load measuring device according to claim 1, wherein the load sensor is provided on a part of the leaf spring support member. 4. The vehicle load measuring device according to claim 1, wherein the load sensor is provided in a part of the axle. 5. The vehicle load measuring device according to claim 1, wherein the opposing surfaces of the opposing leaf springs of the leaf spring other than the load load concentrated portion are in a non-contact state.
A load measuring device for a vehicle, wherein a spacer is provided between the opposed leaf springs. 6. The vehicle load measuring device according to claim 1, wherein an end portion of one of the opposed leaf springs constituting the leaf spring is bent near the end thereof. A load measuring device for a vehicle, wherein an inner surface near a processed end is the load load concentrating portion.