JP6657669B2 - Leaf spring suspension system - Google Patents

Description

  The present invention relates to an improvement of a leaf spring type suspension device.

  2. Description of the Related Art Various types of suspension devices for vehicles have been known. Among such suspension systems of various structures, the so-called leaf spring type vehicle suspension system has a simple and robust structure and can be manufactured at a lower cost than suspension systems of other structures. , Buses and other large transport vehicles and light commercial vehicles (light trucks, vans, etc.).

FIG. 6 shows an example of a conventional structure of the leaf spring suspension device 1 described in Patent Document 1. The leaf spring suspension device 1 includes a shackle 2, a leaf spring 3 formed by stacking a plurality of leaf springs, and an axle support 4.
The shackle 2 is formed of a pair of substantially elliptical plate members provided in a state separated from each other in the width direction (the width direction is the width direction of the vehicle). One end in the longitudinal direction is supported by a rear spring bracket 6 fixed to the vehicle body frame 5 so as to be swingable about the support pin 7. The rear spring bracket 6 is fixed to a portion of the vehicle body frame 5 on the rear side of the axle 8.
The leaf spring 3 is provided with a pair of annular support rings 9a and 9b at both ends in the front-rear direction (the left-right direction in FIG. 6 and the front-rear direction of the vehicle body). The front end portion (support ring portion 9a) of such a leaf spring 3 is supported by a front spring bracket 10 fixed to the vehicle body frame 5 so as to be able to swing around a swing pin 11. . On the other hand, a rear end portion (support ring portion 9b) of the leaf spring 3 is provided on the other end in the longitudinal direction of the shackle 2 (both plate-like members constituting the shackle 2) with a swing pin 12 as a center. It is supported so that it can move. As a result, the rear end portion (support ring portion 9b) of the leaf spring 3 is supported in a state in which the rear end portion of the leaf spring 3 is capable of swinging displacement and displacement in the front-rear direction with respect to the body frame 5.
The axle support part 4 is for supporting the axle 8, and is constituted by a U-bolt supported and fixed to the center of the leaf spring 3 in the front-rear direction. The axle 8 is inserted inside the axle support 4.

  In this manner, the rear end of the leaf spring 3 (the support ring 9b) is supported via the shackle 2 so as to be capable of swinging displacement and longitudinal displacement with respect to the vehicle body frame 5 so that the leaf spring 3 is supported. The leaf spring 3 is allowed to bend (elastically deform) when a load is applied to the spring 3 so that vibrations and impacts received from the road surface by the axle 8 during traveling are not transmitted directly to the body frame 5. ing.

  By the way, the load weight of a vehicle is specified. If the vehicle is operated in a state where the load is exceeded (overloaded state), the mobility of the vehicle may be reduced, which may cause an accident. Further, if the operation is continued in an overloaded state, the road surface may be severely damaged, and the cost of road maintenance may increase. Such an overloaded state may be caused by the driver not being able to grasp the actual load amount, and a means for notifying the driver of the overloaded state is required.

JP 2001-113926 A

  The present invention has been made in view of the above-described circumstances to achieve a structure capable of notifying a driver of an overloaded situation.

A leaf spring type suspension device of the present invention includes a shackle, a leaf spring, an axle support, and a sensor device.
Of these, the shackle is swingably supported and fixed to the vehicle body.
The leaf spring is configured by a leaf spring that can be flexibly deformed. One end of the leaf spring in the front-rear direction is supported so as to be swingable with respect to the vehicle body. On the other hand, the other end in the front-rear direction of the leaf spring is swingably supported by the shackle so as to be supported in a state capable of being displaced in the front-rear direction with respect to the vehicle body.
The axle support portion is for supporting an axle, and is provided at an intermediate portion of the leaf spring in the front-rear direction.
The sensor device is for detecting an overloaded state, and the sensor body is a detection unit fixed to the rear of a portion of the vehicle body where the shackle is swingably supported , and A non-contact type including a detected convex portion , which is a detected portion provided in a state protruding rearward on the shackle , wherein the detected convex portion faces a detection surface of the sensor main body. The surface to be magnetized or the magnet is adhered, and is caused by the longitudinal displacement of the other longitudinal end of the leaf spring caused by a change in the vertical distance between the vehicle body and the axle. An output signal is changed based on a displacement of the shackle with respect to the vehicle body during the swinging movement of the shackle. Note that a contact-type sensor device can be used as the sensor device, although it is outside the technical scope of the present invention.

According to the leaf spring type suspension device of the present invention configured as described above, it is possible to realize a structure capable of notifying a driver of an overloaded situation.
That is, the leaf spring type suspension device of the present invention includes a sensor device that changes an output signal based on a displacement at the time of the shackle swinging movement accompanying the displacement of the other end of the leaf spring in the front-rear direction with respect to the vehicle body. ing. Thus, the amount of deflection of the leaf spring (the amount of displacement of the other end of the leaf spring in the front-rear direction) according to the load of the vehicle can be obtained as an output signal of the sensor device. If the load amount is calculated based on the output signal of such a sensor device, a system for notifying the driver of the load amount of the vehicle can be easily constructed.

1A is a schematic view of a leaf spring type suspension device according to a first embodiment of the present invention, and FIG. 2A is a schematic view illustrating a state in which a vehicle has a small load, and FIG. (B). Similarly, the A section enlarged view of FIG. The figure similar to FIG. 2 which shows the 1st example of the reference example regarding this invention. The figure similar to FIG. 2 which shows the 2nd example of the reference example regarding this invention. The figure similar to FIG. 2 which shows the 3rd example of the reference example regarding this invention. The figure which shows an example of the conventional structure of a leaf spring type suspension device.

[First Example of Embodiment]
A first example of an embodiment of the present invention will be described with reference to FIGS. The leaf spring type suspension device 1a of this example is used by being incorporated in a vehicle such as a large transport vehicle such as a truck or a bus, or a light commercial vehicle (for example, a light truck or van). FIG. 1 schematically shows a state in which the leaf spring suspension device 1a of the present embodiment is incorporated in the vehicle.
Such a leaf spring suspension device 1a of this example includes a shackle 2a, a leaf spring 3a, an axle support 4a, a sensor device 13, and a calculator (not shown).

The shackle 2 a has a shackle body 14 and a detected convex portion 15.
The shackle body 14 is a pair of substantially elliptical plate-like members (see FIGS. 1 and 2, a plate-like member on the outside in the width direction) provided in a state of being separated in the width direction (the front and back directions in FIGS. 1 and 2). Only the one shackle main body 14 (both plate-like members constituting the shackle main body 14) is disposed at a portion near one end (the upper end in FIG. 1) in the longitudinal direction of the two plate-like members. A pair of circular first through holes 16 penetrating in the front-back direction are formed. The shackle body 14 (both plate-like members constituting the shackle body 14) is provided with a shackle body 14 (both plate-like members constituting the shackle body 14) near the other end (lower end in FIG. 1) in the longitudinal direction. A pair of circular second through holes 17 penetrating in the thickness direction of the member) are formed.

  The detected convex portion 15 is one side surface in the short direction of a plate-like member disposed outside (in the front side in FIGS. 1 and 2) in the width direction of both plate-like members constituting the shackle body 14. The right side｝ of a) is provided at the center in the longitudinal direction in such a manner as to project rightward from the one side toward the rear of the vehicle. Such a detected convex portion 15 is formed in a plate shape, and is provided integrally with the shackle body 14 by press molding or the like. In the case of this example, at least the upper surface of the detected convex portion 15 is magnetized, so that the portion is used as the detected surface 18. Instead of magnetizing the detected convex portion 15, a detected surface can be formed by bonding a magnet to the upper surface of the detected convex portion 15.

  The shackle 2a having the above-described configuration is supported by the rear spring bracket 6a fixed to the vehicle body frame 5 so as to be able to swing around the support pin 7. Specifically, a support pin is provided in a through hole (not shown) formed in the rear spring bracket 6a and in both first through holes 16 of the shackle 2a (both plate-like members constituting the shackle 2a). 7 is crossed (inserted). The rear spring bracket 6a is fixed to a portion of the vehicle body frame 5 that is behind the axle 8 (for example, a rear axle).

In addition, the support pin 7 has an axial middle portion fixedly fitted in a through hole of the rear spring bracket 6a by interference fitting, and both axial end portions are respectively provided in the first through holes 16. The support pin 7 is fitted inside the shackle 2a so that the support pin 7 can rotate. A not-shown retaining structure is provided between the shackle 2a and the support pin 7.
However, the intermediate portion of the support pin 7 in the axial direction is fitted into a through hole of the rear spring bracket 6a so that the support pin 7 can rotate with respect to the rear spring bracket 6a. It is also possible to adopt a configuration in which both ends in the axial direction are internally fitted and fixed to the first through holes 16 by tight fit. When this configuration is adopted, a retaining structure is provided between the support pin 7 and the rear spring bracket 6a.
Further, an axially intermediate portion of the support pin 7 is fitted in a through hole of the rear spring bracket 6a so that the support pin 7 can rotate with respect to the rear spring bracket 6a. It is also possible to adopt a configuration in which both ends in the direction are respectively fitted in the first through holes 16 to the extent that the support pin 7 is rotatable with respect to the shackle 2a. When this configuration is adopted, a retaining structure is provided between the support pin 7 and the rear spring bracket 6a and between the support pin 7 and the shackle 2a.

  The leaf spring 3a is configured by vertically overlapping a plurality of flexibly deformable leaf springs. The leaf spring 3a is provided with a pair of annular support rings 9a and 9b at both ends in the front-rear direction. In the illustrated structure of the leaf spring 3a, a plurality of leaf springs constituting the leaf spring 3a are omitted. The structure of the leaf spring 3a is substantially the same as the structure of the leaf spring 3 provided in the leaf spring type suspension device of one example of the conventional structure described above.

The leaf spring 3a having the above-described configuration includes a front spring bracket 10a in which a front end portion (a support ring portion 9a disposed on the front side of the support ring portions 9a and 9b) is fixed to the vehicle body frame 5. In addition, it is supported so as to be able to swing around the swing pin 11. The front spring bracket 10a is fixed to a portion of the vehicle body frame 5 on the front side of the axle 8.
On the other hand, a rear end portion of the leaf spring 3a (a support ring portion 9b disposed on the rear side of the support ring portions 9a and 9b) is centered on a swing pin 12a with respect to the shackle 2a. It is supported so that it can swing. Specifically, with respect to the width direction, in a state where the support ring 9b is disposed between the two plate-like members constituting the shackle 2a, the support ring 9b and the second through holes of the shackle 2a are provided. The swing pin 12a is bridged (inserted) with the hole 17. Thereby, the rear end of the leaf spring 3a is supported so as to be capable of swinging displacement and longitudinal displacement with respect to the vehicle body frame 5.

  The axle support 4a is for supporting the axle 8, and is formed of a U-shaped bolt supported at the center in the front-rear direction of the leaf spring 3a. The axle 8 is supported inside the axle support 4a. In this state, at least the uppermost leaf spring of the plurality of leaf springs constituting the leaf spring 3a and the axle 8 can be relatively displaced in the front-rear direction. Further, it is also possible to adopt a configuration in which the axle support portion 4a is provided at a position shifted in the front-rear direction from the center portion in the front-rear direction of the leaf spring 3a.

The sensor device 13 includes the detected surface 18 and a sensor body 19.
The sensor body 19 has a detection surface 20 on which a Hall element, which is a magnetic detection element, is incorporated. Such a sensor body 19 is provided on a portion of the body frame 5 slightly behind the rear spring bracket 6 in a state where the detection surface 20 and the detection surface 18 are vertically opposed. Fixed. The sensor device 13 having the above-described configuration changes the output signal based on the displacement of the detected surface 18 with respect to the detection surface 20.
The arithmetic unit calculates a displacement amount of the shackle 2 a with respect to the vehicle body frame 5 based on an output signal of the sensor device 13 (a swing angle, a distance between the detected surface 18 and the detection surface 20, the shackle 2 a And the like, and a function of calculating a load amount of a load loaded on the vehicle body based on the displacement amount.
When the present embodiment is implemented, a configuration in which the sensor device 13 is covered with a cover (not shown) may be employed. By adopting such a configuration, it is possible to prevent the detection surface 20 of the sensor body 19 and the detected surface 18 from being stained by muddy water or the like, and to reduce the measurement accuracy of the sensor device 13.

According to the leaf spring suspension device 1a of the present example having the above-described configuration, it is possible to realize a structure capable of notifying the driver of an overload situation (load amount).
Hereinafter, a method of measuring the load capacity of the vehicle using the leaf spring suspension device 1a of the present embodiment will be described.
FIG. 1A shows a state in which only the weight of the vehicle body acts on the leaf spring 3a. The leaf spring 3a in this state is curved downward at a predetermined curvature in a convex arc shape. Further, the shackle 2a is arranged in a state where the longitudinal direction is located in the vertical direction (the vertical direction of the vehicle body). The detection surface 20 of the sensor main body 19 faces the detection surface 18 of the detection projection 15.

When a person or a load (hereinafter, referred to as a "load") is loaded on the vehicle body from the state shown in FIG. 1A, the leaf spring suspension device 1a is moved to the state shown in FIG. The state shown in FIG. In the state shown in FIG. 1B, the body frame 5 is displaced downward (in a direction closer to the road surface 21) than the state shown in FIG. 1A, but is displaced from the road surface 21 of the axle 8. Position (height) does not change, so that the vertical distance between the vehicle body frame 5 and the axle 8 is reduced, and the distance of the leaf spring 3a in the front-rear direction between both ends in the front-rear direction is increased. The leaf spring 3a bends (resiliently deforms) so that the curvature of the leaf spring 3a becomes small. In this case, positions in the longitudinal direction of the front end of the leaf spring 3a does not change with respect to the front end the front spring bracket 10a, around the pivot shaft 12a, an arrow alpha ₁ in FIG. 1 (b) Swings in the direction indicated by.

On the other hand, the position of the rear end of the leaf spring 3a in the front-rear direction is displaced rearward from the state shown in FIG. Specifically, the rear end portion of the leaf spring 3a, the shackle 2a is relative to the rear spring bracket 6a, rocking in the direction indicated by the arrow alpha ₂ in Fig. 1 (b) about said support pin 7 Along with it to dynamic, while swinging in the direction indicated by the arrow alpha ₃ in FIG. 1 (b) around the pivot shaft 12a relative to the shackle 2a, displaced backward.

  Further, in the case of this example, a displacement amount of the shackle 2a with respect to the vehicle body frame 5 is calculated by the calculator based on an output signal of the sensor device 13, and further based on the displacement amount, Calculate the load capacity of the loaded load. Specifically, when the shackle 2a swings from the state shown in FIG. 1A to the state shown in FIG. 1B, the detection surface 20 of the sensor body 19 and the detected convex portion 15 The distance from the detection surface 18 is reduced. In other words, the detection surface 18 of the detection projection 15 is displaced in a direction approaching the detection surface 20 of the sensor main body 19. As a result, the magnetic flux density passing through the detection surface 20 increases, and accordingly, the output signal of the sensor body 19 increases.

  On the other hand, when the load decreases from the state shown in FIG. 1B, the shackle 2a swings from the state shown in FIG. 1B to the state shown in FIG. Then, the distance between the detection surface 20 of the sensor body 19 and the detection surface 18 of the detection protrusion 15 increases. In other words, the detection surface 18 of the detection projection 15 is displaced in a direction away from the detection surface 20 of the sensor body 19. As a result, the magnetic flux density passing through the detection surface 20 decreases, and accordingly, the output signal of the sensor body 19 decreases.

In any case, the output signal of the sensor main body 19 is transmitted to an arithmetic unit (not shown), and the distance between the detected surface 18 of the detected convex portion 15 and the detection surface 20 of the sensor main body 19, the shackle 2a The amount of displacement such as the swing angle and the amount of displacement of the shackle 2a in the front-rear direction is calculated. Further, based on the displacement amount, the computing unit calculates a load amount of the load loaded on the vehicle body, and notifies a driver of the calculation result.
The process of calculating the load amount from the output signal of the sensor main body 19 or the displacement amount is performed, for example, using a conversion map representing a relationship between the output signal or the displacement amount and the load amount. Can do things. Such a conversion map converts the output signal of the sensor main body 19 into the load amount, converts the output signal of the sensor main body 19 into the displacement amount, or converts the displacement amount into the load amount. For example, a configuration that uses various conversion maps such as a conversion map can be adopted. Also, a method of calculating using a conversion formula or the like without using a conversion map can be adopted.
Further, a sensor for detecting the attitude of the vehicle (for example, a tilt state or the like) is provided, and based on the detection result of the sensor, the calculation (the physical quantity used in the process of calculating the loading capacity, a conversion map, and the like) is corrected. An additional configuration can be adopted. In such a configuration, for example, when a load is loaded in a state where the vehicle is inclined (on a slope or the like), the ratio of the front and rear axle weights (loads acting on the front and rear axles) changes (bias). Therefore, such a change (bias) is corrected based on a detection value of a sensor that detects the attitude of the vehicle. In addition, while the vehicle is running, the leaf spring 3a is constantly deformed (bent) due to irregularities on the road surface and the like, and the detection value (the output signal) of the sensor device 13 is always fluctuated. It is preferable that the calculation of ()) is performed only when the vehicle is stopped.

In the case of this example, a structure is provided in which the sensor body 19 (detection section) is provided on the vehicle body frame 5 side and the detected convex section 15 (detected section) is provided on the shackle 2a side. Alternatively, a structure in which the detection unit is provided on the shackle side and the detected unit is provided on the vehicle body frame side may be adopted. Further, the structure of the detected part is not limited to the structure of the detected convex part 15 of this example. For example, it can be configured by embossing having a flat surface or a shape like a notch.
Further, in the above-described structure, the detected convex portion 15 is magnetized (or a magnet is adhered to the detected convex portion 15), and the magnetic flux generated from the detected convex portion 15 constitutes the sensor device 13. The detection is performed by the detection surface 20 of the sensor main body 19. However, a magnet is provided on the back surface (the surface opposite to the detection surface 20) of the sensor body 19 constituting the sensor device 13 without magnetizing the detected convex portion 15, and the detected convex portion 15 ( It is also possible to adopt a configuration in which a change in magnetic flux due to the displacement of the (steel material) is detected by the sensor body 19 constituting the sensor device 13.
Further, the structure of the sensor device is not limited to the structure of this example. For example, various structures such as a structure using an eddy current can be adopted.

[ First Example of Reference Example ]
A first example of a reference example according to the present invention will be described with reference to FIG. The leaf spring suspension device 1b of the present reference example is different from the first example of the above-described embodiment in the structure of the shackle 2b, the support pin 7a, and the sensor device 13a. Hereinafter, the structures of the shackle 2b, the support pin 7a, and the sensor device 13a will be described.

The shackle 2b constituting the leaf spring type suspension device 1b of the present reference example is a pair of substantially elliptical plate-like members provided in a state of being separated in the width direction. Only the shackle 2b (both plate-like members constituting the shackle 2b) is disposed in the thickness direction (the front and back of FIG. 3) near one end (the upper end in FIG. 3) in the longitudinal direction of these plate-like members. A pair of first through-holes 16a penetrating in the direction (direction). Both first through holes 16a are formed in a partial circular shape having a flat surface portion on the upper part. The shackle 2b (both plate members forming the shackle 2b) has a thickness near the other end (lower end in FIG. 3) in the longitudinal direction of the shackle 2b (both plate members forming the shackle 2b). A pair of circular second through holes 17 penetrating in the vertical direction are formed.

  The support pin 7a is for supporting the shackle 2b so as to be swingable with respect to the rear spring bracket 6a. The outer peripheral surface at the axially intermediate portion of the support pin 7a is formed in a cylindrical shape. On the other hand, both ends in the axial direction of the support pin 7a are formed in a partial cylindrical surface shape in which a flat surface portion is formed on the outer peripheral surface. The axially intermediate portion of the support pin 7a is fitted in a through hole (not shown) of the rear spring bracket 6a. In this state, the support pin 7a is rotatable with respect to the rear spring bracket 6a. On the other hand, one end of the support pin 7a in the axial direction (the rear end in FIG. 3) and the portion near the other end in the axial direction (the portion near the front end in FIG. 3) are respectively the shackle 2b (both sides constituting the shackle 2b). The first through holes 16a of the plate-shaped member). In this state, one end of the support pin 7a in the axial direction (the end on the rear side in FIG. 3), the portion near the other end in the axial direction (the portion near the front end in FIG. 3), and the two first through holes 16a are not connected. Circular fitting. Therefore, the support pin 7a can rotate in synchronization with the shackle 2b. The other end of the support pin 7a in the axial direction protrudes outward from the first through holes 16a in the width direction (the front side in FIG. 3), and the portion is magnetized. Then, the upper surface (flat surface portion) of the portion is the detected surface 18a. A magnet is bonded to a portion of the other half of the support pin 7a in the axial direction, which protrudes outward in the width direction (the front side in FIG. 3) from the first through hole 16a, so that the detection surface 18a is Can also be constructed.

The sensor device 13a includes the detected surface 18a and a sensor body 19a.
The sensor element 19a has a Hall element, which is a magnetic detection element, incorporated in the detection surface 20a. Such a sensor main body 19a is a portion of the vehicle body frame 5 in which the center portion in the front-rear direction of the rear spring bracket 6 is fixed in a state where the detection surface 20a and the detection surface 18a face each other in the vertical direction. Is fixed to the outer side in the width direction (the front side in FIG. 3). The detection surface 20a and the detection surface 18a are in a state shown in FIG. 3 同 様 a state similar to the state shown in FIG. 1 (a). In the operating state｝, they are parallel to each other. Also in the case of the sensor device 13a having the above-described configuration, the output signal is changed based on the displacement of the detected surface 18a with respect to the detection surface 20a. Also in the case of the present embodiment, the sensor device 13a, it may be covered by a cover (not shown).

Above present embodiment having such a structure of the case of the leaf spring type suspension device 1b, from the state shown in FIG. 3, the the body to people and luggage (cargo) are stacked, the leaf spring type suspension system 1b is in a state as shown in FIG. 1 (b). In this state, as in the case of the first example of the above-described embodiment, the leaf spring 3a bends (resiliently deforms) so that the distance between both ends in the front-rear direction increases in the front-rear direction. At this time, the position of the rear end of the leaf spring 3a in the front-rear direction is displaced rearward (to the right in FIG. 3) from the state shown in FIG. Further, the same time, the shackle 2a is relative to the rear spring bracket 6a, swings in the direction indicated by the arrow alpha ₂ in Fig. 3 about said support pin 7a. At this time, the support pin 7a also rotates in the direction of the arrow α2, and the detected surface 18a is tilted (tilted as indicated by the broken line) . Then, the positional relationship between the detection surface 18a and the detection surface 20a changes (the magnetic flux density passing through the detection surface 20a changes), and the output signal of the sensor body 19a changes. The procedure for calculating the load amount of the load loaded on the vehicle body based on this output signal is the same as in the case of the first example of the above-described embodiment.

Also in the case of the present reference example, a magnet is provided on the back surface (surface opposite to the detection surface 20a) of the sensor body 19a constituting the sensor device 13a without magnetizing the detected surface 18a. It is also possible to adopt a configuration in which a change in magnetic flux due to the displacement of the detection surface 18a is detected by the sensor body 19a constituting the sensor device 13a.
Further, in the case of the present reference example, the detected surface 18a is formed on the upper surface of the other end in the axial direction of the support pin 7a. However, the surface to be detected may be formed at an intermediate portion in the axial direction of the support pin 7a (a portion located between the two plate-like members constituting the shackle 2a). When such a configuration is adopted, the sensor main body is provided at a position in the body frame 5 that can face the detection surface.
Other structures, operations and effects are the same as those in the first example of the above-described embodiment.

[ Second example of reference example ]
A second example of a reference example according to the present invention will be described with reference to FIG. The structure of the sensor device 13b of the leaf spring suspension device 1c of the present reference example is different from that of the first example of the above-described embodiment and the first example of the reference example . Hereinafter, the structure of the sensor device 13b will be described.

The sensor device 13b constituting the leaf spring suspension device 1c of the present reference example includes an encoder 22, a transmitting member (not shown), and a sensor body (not shown).
The encoder portion 22 is provided around the first through hole 16 of the plate member provided outside in the width direction of the pair of plate members constituting the shackle 2c. The shackle 2c is formed radially about the central axis and penetrated in the thickness direction of the shackle 2c (a plate-shaped member disposed outside in the width direction of both plate-shaped members constituting the shackle 2c). It is composed of a plurality of slits 23, 23 and flat plate portions 24, 24 formed in a portion between the slits 23, 23 in the circumferential direction of the first through hole 16. The slits 23 are formed such that the intervals between the adjacent slits 23 are equal (equal pitch).

The transmitting member is, for example, a magnet or a light emitting element, and includes an outer side surface (a front side surface in FIG. 4) in a width direction (a front and back direction in FIG. 4) of the rear spring bracket 6a and both plates forming the shackle 2c. The plate-shaped member is provided at a portion between the plate-shaped member and a width-direction inner side surface of the plate-shaped member provided outside in the width direction. Specifically, the transmitting member is provided at a position on the outer side surface in the width direction of the rear side spring bracket 6a that overlaps the slits 23 in the width direction. Such a transmitting member is configured to always generate a magnetic flux (when the transmitting member is a magnet) or light (when the transmitting member is a light emitting element).
The sensor main body is disposed on the outer side in the width direction (the front side in FIG. 4) of the sensor main body with respect to the shackle 2c (the plate-shaped member provided on the outer side in the width direction of the two plate-shaped members constituting the shackle 2c). The detection surface is provided in a state facing the transmitting member in the width direction. The sensor main body is supported and fixed to the vehicle body frame 5. Such a sensor main body outputs a pulse signal based on a change in magnetic flux or light transmitted from the transmitting member and passing through the detection surface. Specifically, the output is set to High when the magnetic flux or light passes through the detection surface, and the output is set to Low when the magnetic flux or light does not pass.
Further, a configuration in which the sensor main body and the encoder unit 22 are covered with a cover (not shown) may be employed.

Above present embodiment having such a structure of the case of the leaf spring type suspension device 1b, from the state shown in FIG. 4, the the body to people and luggage (cargo) are stacked, the leaf spring type suspension system 1c is in a state as shown in FIG. In this state, as in the case of the first example of the above-described embodiment, the leaf spring 3a bends (resiliently deforms) so that the distance between both ends in the front-rear direction increases in the front-rear direction. At this time, the position of the rear end of the leaf spring 3a in the front-rear direction is displaced rearward (to the right in FIG. 4) from the state shown in FIG. Further, the same time, the shackle 2c is relative to the rear spring bracket 6a, swings in the direction indicated by the arrow alpha ₂ in Fig. 4 the support pin 7 as the center. Then, the encoder unit 22 rotates about the support pin 7, and a predetermined number of the slits 23, 23 corresponding to the amount of displacement of the swing and the flat plate portions 24, 24 alternately transmit the transmission signal. It passes between the member and the detection surface of the sensor body. Accordingly, a state where the magnetic flux (or light) passes through the detection surface and a state where the magnetic flux (or light) does not pass alternately occur. As a result, the sensor main body outputs High and Low alternately. In the case of the present reference example, for example, the number of rising edges when the output signal becomes High or the number of falling edges when the output signal becomes Low among the output signals of the sensor body is calculated by an unillustrated calculation. It is configured to count by a container. Then, based on the result of the counting, the displacement amount such as the swing angle of the shackle 2c and the longitudinal displacement amount of the shackle 2c is calculated. Further, the computing unit calculates the load amount of the load loaded on the vehicle body, and notifies the driver of the calculation result. Other structures, operations and effects are the same as those in the first example of the above-described embodiment.

[ Third example of reference example ]
A third example of a reference example according to the present invention will be described with reference to FIG. In the leaf spring suspension device 1d of the present reference example, the inner diameter of the first through hole 16a of the shackle 2d is larger than that of the first example of the above-described embodiment. A radial ball bearing 25 with a sensor device is provided between the inner peripheral surface of the first through hole 16b and the outer peripheral surface of the support pin 7b. The radial ball bearing 25 with the sensor device includes an outer ring (not shown) having an outer raceway on an inner peripheral surface, an inner ring (not shown) having an inner raceway on the outer peripheral surface, and a space between the outer raceway and the inner raceway. A plurality of balls 26, 26, a retainer (not shown) for rollingly holding each of the balls 26, 26, a sensor device (not shown), and a pair of seal rings are provided. ing.

Of these, the outer ring is internally fitted and fixed to the inner peripheral surface of the first through hole 16b by interference fit. That is, the outer ring rotates integrally with the shackle 2d with the swing of the shackle 2d.
The inner race is externally fitted and fixed to the outer peripheral surface of the support pin 7b by interference fit.
In the case of the present reference example, the support pin 7b has an axial half portion fixedly fitted in a through hole of the rear spring bracket 6a by interference fitting. Therefore, the inner ring does not rotate with respect to the vehicle body.

The sensor device includes an encoder (detected portion) (not shown) provided on the outer race, and a sensor body (detector) (not shown) provided on the inner race.
Among these encoders, for example, the encoder has a cylindrical shape, and N poles and S poles are alternately arranged at equal pitches in the circumferential direction on the inner peripheral surface which is the surface to be detected. Such an encoder is fixed to a part of the outer ring so that the central axis is coaxial with the central axis of the outer ring.
The sensor main body is of a magnetic detection type in which a magnetic detection element such as a Hall element or a magnetoresistive element is incorporated on a detection surface, and the detection surface is in close proximity to a part of a detected surface of the encoder. And is fixed to the inner ring. Such a sensor body changes an output signal (for example, outputs a pulse signal or a sine wave signal) in response to a change in the characteristic of the detected surface of the encoder in the circumferential direction.
The two seal rings are present between the inner peripheral surface of the outer race and the outer peripheral surface of the inner race, and are for closing both axial openings of the rolling element arrangement space for disposing the balls. is there.

Above present embodiment having such a structure of the case of the leaf spring type suspension system 1d of from the state shown in FIG. 5, the the body to people and luggage (cargo) are stacked, the leaf spring type suspension system 1d is in a state as shown in FIG. 1 (b). In this state, as in the case of the first example of the above-described embodiment, the leaf spring 3a bends (resiliently deforms) so that the distance between both ends in the front-rear direction increases in the front-rear direction. At this time, the position of the rear end of the leaf spring 3a in the front-rear direction is displaced rearward (to the right in FIG. 5) from the state shown in FIG. Further, the same time, the shackle. 2d, with respect to the rear spring bracket 6a, swings in the direction indicated by the arrow alpha ₂ in Fig. 5 about the support pin 7b. At this time, the encoder rotates together with the outer ring. Then, the characteristic of the portion of the detected surface of the encoder facing the detection surface of the sensor main body changes alternately, and the output signal of the sensor main body also changes in accordance with this change. Based on the output signal, an arithmetic unit calculates a swing angle of the shackle 2d or a displacement amount such as a longitudinal displacement amount of the shackle 2c, and further calculates the vehicle body based on the displacement amount. Is calculated, and the result of the calculation is notified to the driver.

In the case of the leaf spring type suspension system 1d of the present embodiment having the above-described configuration, by the sensor device with radial ball bearings 25, the inner peripheral surface of the first through-hole 16b, the outer peripheral surface of the support pins 7b A radial load acting on the portion between the bearings can be supported. As a result, the durability of the portion can be improved, and the riding comfort can be improved.

In the case of the present embodiment, the sensor device with radial ball bearings 25, and the inner peripheral surface of the first through-hole 16b of the shackle 2d, it is provided between the outer peripheral surface of the support pins 7b. However, it is also possible to adopt a configuration in which the radial ball bearing with sensor device 25 is provided between the inner peripheral surface of the second through hole 17 of the shackle 2d and the outer peripheral surface of the swing pin 12a.
Further, it is also possible to adopt a configuration in which the sensor body constituting the sensor device is fixed to the outer ring, and the encoder is fixed to the inner ring.
Other structures, operations and effects are the same as those in the first example of the above-described embodiment.

In each example of the first example and reference example of the embodiment of the above mentioned, as the sensor device, is adopted as a non-contact type. It is to be noted that a contact type may be employed, although it is outside the technical scope of the present invention. The means for informing the driver of the overload situation may notify the driver of the overload amount, or may notify the driver only when the overload state exceeds the predetermined threshold value and the vehicle is overloaded. .

1, 1a, 1b, 1c, 1d Leaf spring suspension 2, 2a, 2b, 2c, 2d Shackle 3, 3a Leaf spring 4, 4a Axle support 5 Body frame 6, 6a Rear spring bracket 7, 7a, 7b Support pin 8 Axle 9a, 9b Support ring 10, 10a Front spring bracket 11 Swing pin 12, 12a Swing pin 13, 13a, 13b Sensor device 14 Shackle body 15 Detecting convex part 16, 16a, 16b First through hole 17 Second through hole 18, 18a Detected surface 19, 19a Sensor main body 20, 20a Detecting surface 21 Road surface 22 Encoder unit 23 Slit 24 Flat plate unit 25 Radial ball bearing with sensor device 26 Ball

Claims (1)

It has a shackle, a leaf spring, an axle support, and a sensor device,
The shackle is swingably supported and fixed to the vehicle body,
The leaf spring is formed of a leaf spring that can be flexibly deformed. One end in the front-rear direction is supported so as to be swingable with respect to the vehicle body, and the other end in the front-rear direction is swung with respect to the shackle. By being supported as possible, it is supported in a state where displacement in the front-rear direction with respect to the vehicle body is possible,
The axle support portion is for supporting an axle, and is provided at an intermediate portion in the front-rear direction of the leaf spring,
The sensor device is intended for detecting a state of overload, of the vehicle body, and a sensor body the shackle is a detector which is fixed to the rear than swingably supported portion, wherein A non-contact type including a detected convex portion , which is a detected portion provided in a state protruding rearward on the shackle , wherein the detected convex portion faces a detection surface of the sensor main body. The surface to be magnetized or the magnet is adhered, and is caused by the longitudinal displacement of the other longitudinal end of the leaf spring caused by a change in the vertical distance between the vehicle body and the axle. When the shackle swings, the output signal is changed based on a displacement of the shackle with respect to the vehicle body.
Leaf spring suspension system.

Images