JPH0777467A - Suspension load detecting device - Google Patents

Abstract

PURPOSE:To provide a strain gauge excellent in production efficiency and reliability and capable of being simply and efficiently formed with a film. CONSTITUTION:A stay 2 has a hat-shaped cross section opened upward, the center of its bottom wall 21 is fixed to the upper end of the piston 1 of a suspension cylinder, and an upper edge outer periphery section 22 is fixed to a vehicle body 7 via a vibration control rubber body 61. The stay 2 converts the axial load W1' of the piston 1 into the perpendicular load W3 proportional to it. The outer periphery section 31 of a holder plate 3 is fixed to the upper edge outer periphery section 22 of the stay 2, and a hook section 33 is formed at the opening edge of a circular opening 32 provided at its center section. The outer periphery section 42 of a diaphragm member 4 is fitted and hooked on the hook section 33, and a strain gauge is formed on the plate face of a thin inner periphery section 41.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension load detecting device for detecting an input load to a vehicle suspension.

[0002]

2. Description of the Related Art Such a suspension load detecting device is
It is used for applications such as detecting the load input to the suspension and calculating the relative speed of the unsprung side and the unsprung side, and performing damping force control of the suspension and vehicle attitude control.

As a conventional load detecting device of this type, for example, Japanese Patent Laid-Open No. 62-286816 proposes a device in which a strain gauge is directly provided on a constituent member of a suspension.

[0004]

However, in the above-described conventional structure, since the constituent members for providing the strain gauge are relatively large and have a complicated shape, vapor deposition or sputtering is performed in a vacuum furnace having a limited space. It is difficult to form a large number of films at the same time, and it is often difficult to form a strain gauge film itself, and there is a problem in reliability in the case of adhesion or the like.

The present invention solves the above problems, and enables a strain gauge to be easily and efficiently formed into a film.
It is an object of the present invention to provide a suspension load detection device having excellent production efficiency and reliability.

[0006]

The structure of the present invention will be described. A hat-shaped cross-section that opens upward is formed, and its bottom wall 21 is formed.
The center is fixed to the upper end of the piston 1 of the suspension cylinder, and the upper edge outer end portion 22 is fixed to the vehicle body 7, so that the axial load of the piston 1 is converted into a proportional axial load. An outer peripheral portion 31 is fixed to the member 2 and the upper edge outer end portion 22 of the load direction changing member 2, and a disc-shaped support member 3 having a circular opening 32 in the center portion.
Then, the outer peripheral frame portion 42 is locked to the locking portion 33 formed on the opening edge of the circular opening 32 of the support member 3, and the diaphragm member 4 in which the strain gauge is formed on the plate surface of the thin inner peripheral portion 41.
It has and.

[0007]

In the above structure, since the diaphragm member 4 is locked and fixed to the circular opening 32 provided at the center of the load direction changing member 2, it can have a small diameter and the structure is simple.
Therefore, the strain gauges can be simultaneously and easily formed on a large number of diaphragm members 4 in the vacuum furnace, which is excellent in production efficiency and reliability.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, a stay 2 as a load direction changing member is fixed to a piston 1 projecting upward from a suspension cylinder (not shown) by a nut 11 at its upper end. The stay 2 is a bottomed cylindrical body having a hat-shaped cross-section that opens upward, and is fixed to the piston 1 at the center of its bottom wall 21 and has an upper edge outer peripheral portion 22 that is horizontally bent with a constant width. A circular lower holder plate 3 serving as a support member has its outer periphery overlapped.

An upper holder plate 5 of substantially the same shape is further laid on the holder plate 3, and the vehicle body 7 is mounted on the outer peripheral surface 51 of the holder plate 5 via a thick ring-shaped anti-vibration rubber body 61. I support it. The anti-vibration rubber body 61 has L on the top and bottom
Ring-shaped mounting plates 62 and 63 having a V-shaped cross section are joined to each other. Nuts 81 are fixedly mounted on the mounting plates 62 and 63 at equal intervals in the circumferential direction (FIG. 2). I am doing it. A bolt 82 that penetrates the stay 2 and the holder plates 3 and 5 is fastened to each of these nuts 81.

A circular opening 32 having a small diameter is provided at the center of the lower holder plate 3, and the opening edge of the opening 32 is bent to have a U-shaped cross section to form a locking portion 33. An outer peripheral frame portion 42 having a rectangular cross section of the circular diaphragm member 4 is fitted and locked to the locking portion 33. The inner peripheral portion 41 of the diaphragm member 4 has a thin plate shape and faces the opening 32, and a plurality of strain gauges (not shown) are formed on the upper surface of the inner peripheral portion 41 as a film. The arrangement of the strain gauges is publicly known, and for example, one pair of point symmetric positions is made active, and the other pair is made dummy and formed at four positions on the circumference.

The central portion of the upper holder plate 5 is the holder plate 3 described above.
Corresponding to the opening 32 of the
Is bent so as to press the outer peripheral frame portion 42 of the diaphragm member 4. The holder plate 5 is provided with a cover plate 9 having a hat cross-section that covers the diaphragm member 4 and opens downward. The cover plate 9 has an O-ring 91 on the entire outer peripheral edge.
Is fixed by caulking with a caulking piece 53 on the holder plate 5. A printed circuit board 92 is disposed along the top wall of the cover plate 9, and on the circuit board 92,
A circuit is formed to connect the strain gauge to the bridge to supply power and process the output signal.

In the above structure, when the upper load W1 '(FIG. 1) acts on the piston 1, the upper edge outer peripheral portion 2 of the stay 2 is
2, a reaction force of W1 is generated, and along with this reaction force W1, a bending moment force W2 that expands the cylinder upper portion of the stay 2 around the bottom wall corner portion O of the stay 2 is generated. This moment force W2 acts on the holder plate 3 as a horizontal component force W3 that pulls it radially outward, and causes the diaphragm member 4 fixed at the center thereof to expand and deform. An output appears on the strain gauge according to the strain amount at this time, and this output is proportional to the load W1 '. When a downward load is applied to the piston 1, contrary to the above, the diaphragm member 4 is contracted and deformed, and in this case also, an output corresponding to the downward load is obtained in the strain gauge.

According to this structure, the diaphragm member 4 provided at the center of the holder plates 3 and 5 can have a small diameter, and the whole plate-like member has a simple shape. By accommodating a large number, a strain gauge can be efficiently formed into a film on the plate surface.

Further, since the diaphragm member 4 having the strain gauge is manufactured as a separate body and is held by the holder plates 3 and 5, it is easy to assemble and replace.

The stay 2 does not necessarily have to be cylindrical as long as it has a hat cross section.

[0016]

INDUSTRIAL APPLICABILITY As described above, the suspension load detecting device of the present invention has high reliability and can be manufactured inexpensively and efficiently.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an upper portion of a suspension provided with a load detection device of the present invention.

FIG. 2 is a plan view of a holder plate with a cover plate removed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 piston 2 stay (load direction conversion member) 21 bottom wall 22 upper edge outer peripheral portion (upper edge outer end portion) 3 lower holder plate (supporting member) 31 outer peripheral portion 32 circular opening 33 locking portion 4 diaphragm member 41 inner periphery Part 42 Peripheral frame part

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location G01G 19/12 A (72) Inventor Katsuhiko Ariga 1-1, Showa-cho, Kariya city, Aichi prefecture Nidec Incorporated (72) Inventor Katsuyuki Sano 1 Toyota-cho, Toyota-shi, Aichi Toyota Automobile Co., Ltd.

Claims (1)

[Claims] 1. A hat-shaped cross section that opens upward, the center of the bottom wall of which is fixed to the upper end of the piston of the suspension cylinder, and the outer end of the upper edge is fixed to the vehicle body, so that the axial load of the piston is fixed. A load direction conversion member for converting into a load in the direction perpendicular to the axis, and a disk-shaped support member having an outer peripheral portion fixed to the outer edge of the upper edge of the load direction conversion member and having a circular opening in the center. And a diaphragm member in which an outer peripheral frame portion is locked to a locking portion formed on the opening edge of the circular opening of the support member, and a strain gauge is formed on a thin inner peripheral plate surface. apparatus.