JPS608104A - Floor level detector - Google Patents

Abstract

PURPOSE:To improve both applications for general purposes and applicability for a suspension system in a floor level detector equipped with a floor level adjustor by detecting the floor level of a vehicle from a displacement of a coiled spring in its stretching and contracting motion, said spring being disposed between the upper and lower parts of another spring. CONSTITUTION:When the quantity of fluid in the inner space 14 of an external sleeve 11 is reduced to maintain the floor level of a vehicle low, a coiled spring 15 is contracted with the minimum pitch between each row of the coil wire so that it is densely compacted within the section corresponding to the length L of a detecting coil 18. Since the coiled spring 15 has magnetic characteristics, the apparont magnetic permeability of the magnetic circuit including the magnetic core 19 of the detecting coil 18 and the coiled spring 15 is increased. The inductance of the detecting coil 18 is also increased, on account of which the oscillation frequency of detector 23 is reduced. Variation in floor level is computeal from the oscillation frequency. In case of a high level of the floor of a vehicle, it is similarly computed from variation in frequency. Thus, applications for general purposes and applicability for a suspension system may be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vehicle height detection device for a vehicle equipped with a vehicle height adjustable negative system W.

[Prior art]

An example of a conventional vehicle height detection device is the Japanese Patent Application Laid-Open No. 56-16
No. 2010 (title of invention: displacement measurement transducer). This vehicle height detection device k Irt is used based on the configuration of the suspension system as shown schematically in FIG.
For example, a non-magnetic cylindrical body 2 is arranged outside the magnetic body 1, which responds to the displacement of the lower part of the car body such as a shock absorber, as a magnetic core, and a detection coil 6 is wound around this with the body part as a reference. Then, the magnetic cylinder 1 for the detection coil B
The insertion length of the sensor coil 6 is measured as a change in the inductance or impedance of the detection coil 6, and the vehicle height is thereby detected.

For example, as a device for simply measuring the amount of displacement of a moving body using a coil, there is, for example, Japanese Unexamined Patent Publication No. 55-46200 (title of invention: displacement converter).

Similarly to the above, this device also winds a coil around a non-magnetic, non-conductive cylindrical bobbin, and inserts a magnetic core into this bobbin, so that the inductance of the coil changes slightly depending on the inserted can. Try to measure -C.

However, such conventional vehicle height detection devices are configured to directly measure the amount of displacement of the moving part in response to changes in vehicle height, so the length of the detection coil for detection is This is necessary based on the annual displacement of the moving part 4, and the length of this detection coil must be selected according to the amount of displacement of the moving member, resulting in poor versatility and high cost. The cylindrical body to be wound must be made of a non-magnetic material or a non-conducting material. When a vehicle height detection device is applied to a vehicle suspension system, there are problems such as requiring major structural changes.

[Purpose of the invention]

The present invention has been developed by focusing on such conventional problems, and by detecting the amount of partial expansion and contraction of the coil spring that responds to changes in vehicle height, it is possible to compare the actual amount of vehicle height displacement with the system. Enables vehicle height detection with a short detection coil length, provides versatility and reduces costs, and simplifies the overall configuration, making it easy to apply to suspension systems without major structural changes. The purpose is to solve the above problems.

[Structure of the invention]

In order to achieve the above object, the present invention disposes a coil spring that expands and contracts according to the vehicle height between the sprung portion and the unsprung portion of the vehicle, and has a 9r constant in the coil spring. Vehicle height detection characterized by detecting the vehicle height by measuring the amount of expansion/contraction displacement within a section.

[Effect]

The present invention provides a coil spring that expands and contracts according to the height of the vehicle, and measures the amount of expansion and contraction within a predetermined section of the coil spring. There is one that makes it possible to detect the vehicle height.

〔Example〕

The present invention + IJI will be explained below based on the drawings.

FIGS. 2 and 3 are diagrams showing a practical example of the present invention.

In the figure, 5 is a shock absorber 6 with variable vehicle height.
i) It is an inner cylinder having a ζ shape, and has a front guide 7 fixed to its upper end, and a mounting eye 8 fixed to its lower end to be connected to the unsprung portion of the vehicle. Here, the unsprung portion of the vehicle refers to vehicle parts (including wheels, axles, wheel drive mechanisms, etc.) below the suspension system that supports the vehicle body.

Reference numeral 9 denotes a piston rod inserted into the inner cylinder 5. A piston 10 is fixed to the end inside the inner cylinder 5, and the end outside the inner cylinder 5 is attached to the end plate 12 of the outer cylinder 11. It is fixed.

The outer cylinder 11 is airtightly engaged with the outside of the inner cylinder 5 and is arranged to be movable relative to the inner cylinder 5, and has a mounting eye 16 connected to the sprung portion of the vehicle on its end plate 12. is fixed. Here, the sprung portion of a vehicle refers to the vehicle body supported by a suspension system and its related components. In addition, the outer cylinder 11 is connected to the rod guide 7 of the inner cylinder 5.
By causing gas or liquid to flow in and out of the closed cavity 1Φ part 14 to change the volume of the space, the outer cylinder 11 and the inner cylinder 5 are
The height of the vehicle is adjusted by changing the relative position 1k with respect to the vehicle.

Reference numeral 15 denotes a support plate 16 attached to the outer ζ surface of the inner cylinder 5 and the outer periphery of the outer cylinder 11. It is inserted between the support plate 17 formed on the surface and expands and contracts according to the relative displacement between the inner cylinder 5 and the outer cylinder 11.

Reference numeral 18 denotes a detection coil, which is wound around a magnetic core 19 fixed to the outer cylinder 11. The magnetic core 19 is composed of a cylindrical portion 20 extending along the outer cylinder 11 and magnetic leg portions 21.22 extending outward from both ends of the cylindrical portion 20. The outer end surface of the magnetic leg portion 21.22 faces the coil spring 15. ing.

26 is a detector connected to the detection coil 18,
For example, the detection coil 18 is constituted by an LC oscillator built into a coil serving as an oscillation condition, and the oscillation frequency is changed by changes in inductance of the detection coil 18 as the coil spring 15 expands and contracts.

Next, the action will be explained with reference to the 31st case and (B).

FIG. 3(A) is a cross-section m1 diagram showing a state where the vehicle height is maintained low, that is, a state in which the inner cylinder 5 and the outer cylinder 11 are in the minimum contracted state.
Figure (B) is a cross-sectional view showing the maximum extension state.

Therefore, when the fluid in the space 14 in the outer cylinder 11 is reduced to reach the minimum bilateral r:t18 shown in the 31st prisoner, the coil spring 15 contracts accordingly, and the pitch between the coil wires is reduced. Therefore, the coil supers 15 are densely arranged in the section facing the length l of the detection coil 18. Since the coil spring 15 is made of a magnetic material whose main component is iron or the like, the detection coil 1
In a magnetic circuit including a magnetic core 19 and a coil spring 15 with 8 windings (-'), the apparent magnetic permeability contributed by the coil spring 15 increases. Therefore, the f inductance of the detection coil 18 becomes To increase, the detector 26
oscillation frequency becomes smaller.

From this state, when fluid is injected into the space 14 of the outer cylinder 11 and the outer cylinder 11 is displaced upward with respect to the inner cylinder 5, the coil spring 15 expands accordingly, and the cedar y exits. coil 18
The wire density of the coil spring 15 facing gradually becomes sparse and 0,
The inductance of the detection coil 18 decreases. Therefore, the oscillation frequency of the detector 23 becomes high. Therefore, by measuring the oscillation frequency of the detector 26, the pitch change of the coil spring 15 can be measured. In addition, when the coil spring 15 is a linear spring, the pitch of the coil spring 15 changes in proportion to the change in vehicle height L7, and when the coil spring 15 is a non-linear spring, it changes by a predetermined pitch. Phase β
51 relationships will change. Shidatsu C,
, the displacement of the coil spring 15 with respect to the displacement of the vehicle height is determined in advance by d1.
11, the displacement 1 of the vehicle height can be detected from the amount of displacement of the coil spring 15, that is, the oscillation frequency of the detector 26.

In this case, the maximum displacement of the vehicle height is the length Ll between the eyeballs 8 and 13 at the time of contraction and the length Ll between the eyeballs 8 and 16 at the time of extension, as shown in the 31st prisoner and (IJ). The length 4 of the detection coil 18 is determined in relation to the sensitivity, and the length 4 of the detection coil 18 is determined in relation to the sensitivity. The length of the detection coil 18 with respect to the maximum displacement of the vehicle can be made much shorter.Moreover, the suspension configuration 1
Since the detection target is a coil spring that has already been assembled as a component, there is an advantage that costs can be reduced.

In the above embodiment, the detection coil 18 is connected to the outer cylinder 1.
1 and the coil spring 15, but the present invention is not limited to this, and as shown in FIG. Even if the detection coil 18 and the magnetic core 19 are fixed to the inner surface of the outer cylinder 11 and the coil spring 1, the same effect as in the above embodiment can be obtained.
This is effective when the distance between the magnetic core and the magnetic core is narrow, and there is an advantage that the detector consisting of the detection coil and the magnetic core can be easily inspected and repaired.

Further, as shown in FIG. 5, the coil spring 15, the detection coil 18, and the magnetic core 19 can be installed in the space 14 of the outer cylinder 11. In this case, the detector itself is placed in an airtight room, so it has excellent durability, and a dedicated coil spring is used regardless of whether or not there is a coil spring built into the suspension system, so the sensitivity is improved. It has advantages such as being able to improve the performance and also performing linear detection.

Furthermore, in each of the above embodiments, the case where the present invention is applied to a shock absorber having a variable vehicle height mechanism has been described, but a shock absorber without a variable vehicle height mechanism,
Alternatively, it goes without saying that the present invention can be applied to a separately arranged coil spring that responds to changes in offshore height.

Although we have explained the case where the expansion and contraction of the coil spring 15 is detected as an interface change of the detection coil 18,
The present invention is not limited to this, but it is also possible to arrange an excitation coil and a detection coil in parallel on the magnetic core 19 and detect the vehicle height based on the magnitude of the induced electromotive force in the detection coil due to changes in mutual inductance as the coil spring 15 expands and contracts. ” It is Noh.

Further, in each of the above embodiments, the case where the expansion and contraction of the coil spring 15 is detected in a non-contact manner by electromagnetic field changes is explained, but as shown in FIG. , and the movable iron core 27 is inserted into the coil spring 150 and connected to a point LT from the upper end of the coil spring by a clamp means 26, for example.
It is also possible to detect a change in the insertion length of the movable core 27 into the detection coil 25 due to the expansion and contraction of the coil spring 15 as a change in the inductance of the detection coil 25. In this case, there is a point where the width of change (stroke) of the vehicle height is ΔL and the coil spring 15 is a linear spring. In place of the combination of movable iron core 27 and detection coil 25,
A type of potentiometer consisting of a slider and a resistor provided on a part of a coil spring may be used.

Note that the detector 26 of the detection coil is not limited to a 50 oscillator, and any other detector such as a detector that incorporates a detection coil as a part of a Wheatstone bridge and detects changes in the unbalanced voltage may be used. can.

〔Effect of the invention〕

As explained above, according to the present invention, means is provided for detecting the amount of expansion/contraction displacement within a predetermined section in a coil spring that responds to changes in vehicle height, and the vehicle height is detected based on a signal from the means. Therefore, the vehicle height can be detected with a shorter detection fill length compared to the actual vehicle height change phase, and therefore the vehicle height displacement can be detected using a detection coil of a predetermined length, regardless of the amount of human effort involved. Because it can detect, it has great versatility, it can reduce manufacturing costs, and since the length of the detection coil can be known, there is no need to make major changes to the structure, such as when changing the suspension. Don't get introductions easily :c
'l) Exercising the effect.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional example, Fig. 2 is a sectional view showing an embodiment of the present invention, and Figs.
B) i. Cross-sectional views showing the contracted state and expanded state, respectively. FIGS. 4 to 6 are cross-sectional views showing other practical examples of the present invention. 5...Inner cylinder? ...Piston rod, 11...Outer cylinder, 15...Coil bolt, 18...Detection coil, 1
9...Magnetic core, 26...Detector, 25...Detection coil, 27...Movable iron core. Return 6rXl

Claims (1)

[Claims] By disposing a coil spring that expands and contracts according to the JT height between the upper and lower parts of the vehicle, and providing means for detecting the amount of expansion and contraction within a predetermined section of the coil spring. . A vehicle height detection device, characterized in that the vehicle height is detected by a signal from the means.