JP3099676B2 - Stroke detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stroke detecting device, and is particularly useful when applied to detecting the axle load of an automobile.

[0002]

2. Description of the Related Art In a lorry, for example, an axle load, which is a load applied to the axle of each wheel, is detected. Based on the axle load detection signal, an exhaust brake is inadequate when traveling on a low friction road with an empty vehicle. Exhaust brake control (Japanese Utility Model Laid-Open Publication No. 64-4644) for controlling the vehicle to be operated in no time, and the steering force of the steering that changes according to the lightness of the axle load between when the vehicle is empty and when the load is loaded is detected. Power steering control and the like for controlling to keep the voltage constant based on a signal are performed.

FIG. 7 is a block diagram showing a conventional example of an axle load detecting device used for such control. As shown in the figure, the main body side of a rotation angle sensor 5, which is a rotary potentiometer, is fixed to a frame 24, and the base end of an arm 21 is fixed to the rotation shaft 6 of the rotation angle sensor 5. . An upper end of a rod 22 is rotatably connected to a tip of the arm 21, and a lower end of the rod 22 is rotatably connected to a lower end of a suspension 25. In addition, 23 in FIG. 7 is a wheel.

Therefore, according to the axle load detecting device having the above structure,
When the suspension 25 is displaced linearly in the vertical direction as shown by the arrow C in FIG. 7, the rod 22 is also displaced in the vertical direction along with this, and the arm 21 is moved by the rod 22 as shown in the arrow D. Rotate around the end. As a result, the rotation shaft 6 rotates, and a detection signal (voltage signal) corresponding to the rotation angle at this time is output from the rotation angle sensor 5. Thus, a stroke that is the amount of linear displacement of the suspension 25 in the vertical direction is detected.

Therefore, for example, when a load is loaded on a lorry and the suspension 25 is displaced upward due to the axle load of the load, the stroke at this time is detected by the rotation angle sensor 5. By multiplying the stroke detection value by the spring constant of the suspension 25, an axle load is obtained (suspension stroke × spring constant = axle load).

[0006]

In the axle weight detecting apparatus according to the 0006] However the prior art, as shown in FIG. 8 (a), the total stroke range S ₁ is the effective rotation angle of the rotation angle sensor 5 of the suspension 25 (- θ ₂ to + θ ₂ ), the stroke range S ₂ (the range displaced by the axle load) that needs to be detected is ₂ of the entire stroke range S ₁ .
Because it is about 0%, as shown in FIG. 8 (b), the stroke detection range of S _2, the effective rotation angle (-θ ₂ ~ + θ
Only the output voltage of about several volts among the output voltages (0 to 10 V) corresponding to ₂ ) is used. Therefore the detection accuracy of the stroke (resolution) is poor in comparison with the case of detecting the stroke of the range S ₂ with the entire effective rotation angle. That is, the axle load detection accuracy (resolution) is poor.

[0008] As shown in FIG.
1 of length (from the rotation center P of the rotary shaft 5 to the point of attachment to the rod 22 length) from conventional L ₁ and short L _2, stroke range S ₂ is effective rotation angle requiring detection (- θ ₂ ~
+ Θ ₂ ), the stroke in the range of S ₂ can be detected using the entire output voltage of 0 to 10 V, and the detection accuracy (resolution) can be improved. In this case, Suspension 2 due to unevenness of road surface
When 5 is displaced beyond the range of S _2, will be rotating shaft 6 is rotated above the effective angle of rotation, as a result, the rotation angle sensor 5 is damaged.

Accordingly, in view of the above prior art, the present invention is a stroke detecting device applicable to a load detecting device and the like,
Provided is a stroke detection device capable of detecting a stroke in a desired range using the entire effective rotation angle of a rotation angle sensor and having no risk of damaging the rotation angle sensor even if a detection target is displaced beyond this range. With the goal.

[0009]

According to a first aspect of the present invention which achieves the above object, a rotation angle sensor having a rotation axis and outputting a detection signal according to the rotation angle of the rotation axis is provided. A mechanism interposed between the object to be displaced and the rotation axis, the mechanism for changing the linear movement of the object into rotation and rotating the rotation axis, and detecting a stroke as a displacement amount of the object. In the detection device, a base end portion is fixed to the rotation shaft, and a groove extending from the base end side in a radial direction about a rotation center of the rotation shaft and having a length corresponding to at least a full stroke of the object is formed. The arm provided is fixed to the main body of the rotation angle sensor so as to overlap with the arm, and is arranged along a rotation trajectory on a base end side of a groove of the arm and corresponds to an arbitrary rotation angle of the rotation shaft. Arc with length And a second groove extending radially from at least one end of the first groove around the rotation center and having a length corresponding to at least the full stroke. A rod provided with a groove, and a rod rotatably coupled to a position where a distal end moves while being guided by the groove of the arm and a guide groove of the rail, and a base end displaces with the object. And the above-mentioned mechanism is configured.

[0010] In a second configuration, in the first configuration, the arc-shaped groove provided on the rail has a length corresponding to the effective rotation angle of the rotation angle sensor and is within the stroke range of the object that needs to be detected. It has a corresponding length.

A third configuration is the same as the first configuration, except that the object is a vehicle suspension, and the base end of the rod is rotatably coupled to a position where the rod is displaced together with the suspension. Second grooves are provided at both end sides of the first groove, and the second grooves have a length corresponding to the entire stroke of the suspension, and the first groove has an effective rotation angle of a rotation angle sensor. The suspension has a length corresponding to a stroke range of the suspension that requires detection.

[0012]

According to the first aspect of the present invention, when the object is displaced, the distal end of the rod moves along the first groove of the rail, and the arm is rotated by the rod. As a result, the rotation axis of the rotation angle sensor rotates within an arbitrary rotation angle range. When the object is further displaced (eg, up to the full stroke), the tip of the rod moves radially along the second groove of the rail. Therefore, the rotation angle of the rotation shaft is maintained within an arbitrary range of the rotation angle, and there is no possibility that the rotation angle sensor is damaged at this time.

According to the second aspect of the present invention, the effective rotation angle of the rotation angle sensor corresponds to the stroke range that needs to be detected, and the stroke within this range is detected using the entire effective rotation angle.

According to the third aspect of the present invention, the effective rotation angle of the rotation angle sensor corresponds to the stroke range of the suspension that needs to be detected, and the stroke within this range is detected using the entire effective rotation angle. You.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. In this embodiment, a case is described in which the stroke detection device of the present invention is applied to an axle load detection device of an automobile.

FIG. 1 is an explanatory diagram showing the state of the axle load detecting device according to the embodiment of the present invention when it is unloaded. FIG. 2 is an explanatory diagram showing the state of the axle load detecting device shown in FIG. 1 when it is loaded. 3 is an explanatory diagram showing a state of the axle load detecting device shown in FIG. 1 when the suspension is raised, FIG. 4 is an explanatory diagram showing a state of the axle load detecting device shown in FIG. 1 when the suspension is suspended, and FIG.
6 is an enlarged view of a main part of the axle load detecting device shown in FIG.

As shown in FIGS. 1, 5 and 6, the axle load detecting device according to the present embodiment comprises a rotation angle sensor 5 and an arm 1
, A rail 3, and a rod 7, and the amount of vertical displacement (stroke) of the suspension 10 schematically illustrated.
, The axle load on the axle of the front wheel 11 is detected.

The rotation angle sensor 5 is the same as the rotation angle sensor 5 shown in FIG. 7, and its main body is fixed to the side surface of the frame 9. A base end of the arm 1 is fixed to a rotation shaft 6 of the rotation angle sensor 5.
Has a linear shape extending radially from the base end thereof around the rotation center P of the rotating shaft 6 (hereinafter referred to as point P) and having a length corresponding to the entire stroke range S ₁ of the suspension 10. A groove 2 is provided.

The rail 3 is occupied so that the distal end thereof overlaps the arm 1, and a base bent portion 3 a is fixed to the side surface of the frame 9. The rail 3 is provided with a guide groove 4 including a first groove 4a and second grooves 4b and 4c. The first groove 4a has an arm 1
Along the rotation trajectory of the base end of the groove 2 when rotating around the point, the effective rotation angle of the rotation angle sensor 5 (−θ ₂ to +
θ ₂ ), and has a length corresponding to the stroke range (range of displacement due to axle load) S ₂ of the suspension 10 that needs to be detected. Second groove 4
b, 4c extends in a radial direction around the point P from each end of the first groove 4a, yet has a length corresponding to the entire stroke range S ₁ of the suspension 10.

The rod 7 is provided at its upper end with a ball joint 7a and a sleeve 7b fixed to one end of the ball joint 7a.
b is inserted through the groove 2 of the arm 1 and the guide groove 4 of the rail 3. On the other hand, the lower end of the rod 7 is
As shown in FIG. 1, it is coupled to the lower end of the suspension 10 via a ball joint 7c so as to be displaced together with zero.

Therefore, according to the axle load detecting device having the above structure,
As shown in FIG. 1, when there is no load on the carrier, the stroke of the suspension 10 is at the lower end of the range of S ₂ , and the upper end of the rod 7 is in the first groove 4 of the rail 3.
It occupies the lower end of a. In other words, when this is empty,
The arrangement and dimensions of each member are adjusted so that the upper end of the rod 7 occupies this position. Thus, the rotation angle of the arm 1 at this time is the rotation angle also - [theta] ₂ of the rotary shaft 6 of the - [theta] _2, and the rotation angle sensor 5 accordingly. At this time, the groove 2 of the arm 1 and the second groove 4c of the rail 3 overlap.

Next, when a load is loaded on the carrier, the load exerts an axle load on the wheels 11, so that the suspension 10 is displaced upward, and the rod 7 is also displaced upward. Therefore, the upper end of the rod 7 is
The arm 7 is rotated counterclockwise by the rod 7 and guided upward by the groove 4a. As a result, the rotating shaft 6 also rotates counterclockwise.

[0023] Then, as shown in FIG. 2, when the load weight is applied the maximum axle load W _m to the wheels 11 at maximum, the upper end of the rod 7 is Uranaii the upper end of the first groove 4a . At this time the rotation angle of the arm 1 + theta _2, and becomes a rotation angle even + theta ₂ of the rotary shaft 6 accordingly. At this time, the groove 2 of the arm 1 and the second groove 4b of the rail 3 overlap.

On the other hand, as shown in FIG. 3, there is a convex portion 13 on the road surface 12, and when the front wheel 11 rides on the convex portion 13,
The suspension 10 is displaced to the large upward beyond the range of S _2. At this time, the rod 7 is also largely displaced, but the upper end of the rod 7 is guided by the second groove 4 b of the rail 3,
The second groove 4b moves toward the tip. The stroke of the suspension 10 is maximized (the upper end of the entire stroke range S _1), the distal end portion of the rod 7 is moved to the tip of the second groove 4b, as shown in FIG. While the upper end of the rod 7 moves from the base end of the second groove 4b (the upper end of the first groove 4a) toward the front end, the arm 1 is not rotated, and therefore, the rotary shaft 6 is not rotated. . Thus the rotation angle of the rotary shaft 6 is kept at the + theta _2.

Further, as shown in FIG. 4, there is the recess 14 in the road surface 12, the front wheel 11 falls into the recess 14, the suspension 10 is displaced to the large downward beyond the range of S _2. At this time, the rod 7 is also largely displaced.
Is guided by the second groove 4c of the rail 3 and moves toward the front end of the second groove 4c. The stroke of the suspension 10 is maximized (the lower end of the entire stroke range S _1), the distal end portion of the rod 7 is moved to the tip of the second groove 4c as shown in FIG. Thus, rod 7
Is the base end of the second groove 4c (the lower end of the first groove 4a)
While moving from to the tip, the arm 1 is not rotated, and thus the rotating shaft 6 is not rotated. Therefore, the rotating shaft 6
Is kept at −θ ₂ .

As described above, according to the axle load detecting device according to the present embodiment, the effective rotation angle of the rotation angle sensor 5 (−θ ₂ to + θ ₂ )
θ ₂ ) can correspond to the stroke range S ₂ of the suspension 10 that needs to be detected, and a stroke within this range can be detected using the entire effective rotation angle. For this reason, the stroke detection accuracy (resolution) is improved. That is, the detection accuracy (resolution) of the axle load (the stroke of the suspension 10 × the spring constant of the suspension 10) is improved. Therefore, a more effective axle load detection signal can be obtained when performing steering force control or the like for steering.

Moreover, when the suspension 10 is_TwoRange
If the rod 7 is displaced more than this, the upper end of the rod 7
The second grooves 4b and 4c of the tool 3 toward the respective tips.
By guiding the arm 1, the effective rotation angle (-θ_Two~
+ Θ_Two) It can be prevented from being rotated more than that.
Therefore, the rotation axis 6 of the rotation angle sensor 5 is set to the effective rotation angle (−θ _Two
~ + Θ_Two) Rotation angle sensor without rotation
5 is not likely to be damaged.

If the above-mentioned axle load detecting device is provided on the rear wheel side, the loaded weight can be detected by this axle load detecting device.

In the above embodiment, the first groove 4 of the rail 3 is used.
The second groove 4b and the second groove 4c are respectively provided on both end sides of the first groove c. For example, when the stroke range requiring detection is located at one end of the entire stroke range, the first groove 4b is formed. The second groove may be provided only on one end side of the.

In the above-described embodiment, a rotary potentiometer is used as the rotation angle sensor 5. However, the present invention is not limited to this, and the rotation angle sensor 5 has a rotation shaft and outputs a detection signal corresponding to the rotation angle of the rotation shaft. If it is a sensor that outputs,
It can be applied to the present invention.

In the above embodiment, the length of the first groove 4a provided in the rail 3 is set to a length corresponding to the effective rotation angle of the rotation angle sensor 5 and to the stroke range S ₂ of the suspension 10. The first groove 4 has a corresponding length.
By appropriately setting the length of “a”, an arbitrary rotation angle of the rotation angle sensor 5 can be set as a detection range, and the arbitrary rotation angle can be associated with an arbitrary stroke range.

[0032]

According to the present invention, as described above in detail with the embodiments, by providing a rail or the like having a guide groove comprising a first groove and a second groove, it is possible to provide an arbitrary rotation angle sensor. Can be used as a detection range, and this arbitrary rotation angle can be made to correspond to an arbitrary stroke range.

In particular, by setting the first groove of the rail to have a length corresponding to the effective rotation angle of the rotation angle sensor and a length corresponding to the stroke range of the object requiring detection, the stroke in this range can be effectively rotated. Since the detection can be performed using the entire corner, the stroke detection accuracy (separation ability) can be improved.

By setting the first groove of the rail to have a length corresponding to the effective rotation angle of the rotation angle sensor and a length corresponding to the stroke range of the suspension that needs to be detected, the stroke in this range can be effectively rotated. Since the detection can be performed using the entire corner, the stroke detection accuracy (resolution) of the suspension can be improved, and therefore, the detection accuracy (resolution) of the axle load can be improved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a state of an axle load detecting device according to an embodiment of the present invention when there is no load.

FIG. 2 is an explanatory diagram showing a state of the axle load detecting device shown in FIG. 1 at the time of loading.

FIG. 3 is an explanatory diagram showing a state of the axle load detecting device shown in FIG. 1 when the suspension is raised.

FIG. 4 is an explanatory diagram showing a state of the axle load detecting device shown in FIG. 1 when the suspension is suspended.

FIG. 5 is an enlarged view of a main part of the axle load detection device shown in FIG.

FIG. 6 is a view taken in the direction of arrow VI in FIG. 5;

FIG. 7 is a configuration diagram of an axle load detection device according to a conventional technique.

FIG. 8A is an explanatory diagram showing a relationship between a rotation angle of a rotation angle sensor shown in FIG. 7 and a stroke of a suspension;
FIG. 8B is an explanatory diagram illustrating a relationship between a rotation angle of the rotation angle sensor illustrated in FIG. 7 and an output voltage.

[Explanation of symbols]

1 arm 2 grooves 3 rail 4 guide grooves 4a first groove 4b, 4c second groove 5 rotation angle sensor 6 rotary shaft 7 rods 7a, 7c ball joint 7b sleeve 9 frame 10 suspension 11 wheel S ₁ full stroke range S ₂ Stroke range requiring detection

Claims (3)

(57) [Claims] 1. A rotation angle sensor having a rotation axis and outputting a detection signal corresponding to the rotation angle of the rotation axis, and a straight line of the object interposed between the linearly displaced object and the rotation axis. A mechanism for detecting a stroke, which is a displacement amount of the object, comprising a mechanism for rotating the rotating shaft by changing a typical movement into a rotation, wherein a base end is fixed to the rotating shaft, An arm extending from a side in a radial direction about a rotation center of the rotation shaft and having a groove having a length corresponding to at least a full stroke of the object; and the rotation angle sensor overlapping the arm. An arc-shaped first groove fixed to the main body side of the arm and having a length corresponding to an arbitrary rotation angle of the rotation shaft along a rotation trajectory on a base end side of the groove of the arm; From at least one end of A rail provided with a guide groove extending in a radial direction about the rotation center and having a length corresponding to at least the full stroke; and a groove having a tip portion formed by the arm and the rail. And a rod that is guided by the guide groove and moves, and that is rotatably coupled to a position where the base end is displaced together with the object. . 2. The stroke detecting device according to claim 1, wherein the arc-shaped groove provided on the rail has a length corresponding to an effective rotation angle of the rotation angle sensor and corresponds to a stroke range of an object requiring detection. A stroke detecting device, characterized in that the stroke detecting device has a length. 3. The stroke detecting device according to claim 1, wherein the object is a suspension of an automobile, and a base end portion of a rod is rotatably connected to a position displaced with the suspension, and a first end of the rail. Second grooves are provided at both end sides of the first groove, and these second grooves have a length corresponding to the entire stroke of the suspension,
A groove corresponding to the effective rotation angle of the rotation angle sensor and having a length corresponding to a stroke range of the suspension that needs to be detected.