JPH087106B2 - Gasket type pressure sensor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a pressure sensor for detecting a pressure generated from a combustion chamber of an internal combustion engine, hydraulic pressure, or equipment using pneumatic pressure.

(Prior Art) Conventionally, a pressure sensor for detecting and measuring a pressure generated from an internal combustion engine or equipment using hydraulic pressure or pneumatic pressure is an annular pressure receiving portion, that is, a presser foot or an annular piezoelectric element by a plate packing. Hold and fix the electrode plate on which the
−60137).

(Problems to be Solved by the Invention) However, the above-mentioned conventional ones, in particular, Japanese Utility Model Publication No. 61-60137
In the case of No. 1, since the pressure receiving element for detecting and measuring the pressure has an annular shape, only one mold can be made from one wafer, and the yield is poor and the annular shape makes it difficult to manufacture at the time of manufacturing or mounting. However, if a partial load (uneven load) is applied, there is a drawback that it is easily damaged. Therefore, the present invention is intended to improve the drawbacks of the above-mentioned conventional ones, and has a high impact resistance, can reduce the cost, and uses a block-shaped element formed by dividing one piezoelectric element to ensure insulation. At the same time, it is intended to facilitate uniform arrangement on the electrode plate and improve accuracy.

(Means for Solving the Problem) For that purpose, a plurality of penetrating accommodation holes are provided on a concentric circle centered on the shaft center on the insulating plate formed in an annular shape, and the piezoelectric element is divided into the accommodation holes. The upper surface of the block element is fixed so as to project from the insulating plate, and the projecting surface of the block element is brought into contact with an annular plate packing, and the electrode plate is sandwiched by an insulating plate, which is placed in an annular metal case. It is enclosed in.

(Operation) Since the block-shaped element is provided, the element itself can be miniaturized by the block-shaped element, and the strength against a locally applied load can be increased during manufacturing or mounting (screwing). At the same time, a large number of elements can be produced from one wafer at the time of manufacturing the piezoelectric element, and the accommodating hole formed in the insulating plate enables accurate arrangement of the piezoelectric element.

(Example) The present invention will be further described with reference to an example shown in the drawings.
(1) is a gasket-type pressure sensor (1) according to an embodiment of the present invention. The gasket-type pressure sensor (1) includes a metal case (2) having a pressure receiving body sealed therein and a piezoelectric element (10). It is equipped with a protective tube (3) containing a lead wire (11) for transmitting a signal from, and (4) is a through hole for fixing the gasket type pressure sensor (1). First, as a pressure receiver for detecting and measuring pressure, a metal plate packing (5), a ceramic, an insulating plate (6) made of synthetic resin, an electrode plate (8), and an insulating plate (9) such as ceramic are sequentially arranged. A plurality of accommodating holes (7) that are laminated and have an axially penetrating accommodating hole (7) in which a piezoelectric element (10) is arranged along a concentric circle centered on the axis of the insulating plate (6) formed in a ring shape. A piezoelectric element (10) is provided in the housing hole (7) so that one surface of the piezoelectric element (10) projects, and the plate packing (5) is inserted from above.
Is mounted and brought into contact with the protruding surface of the piezoelectric element (10) (FIG. 3). Furthermore, after arranging these laminated ones in an annular metal case (2) having a U-shaped cross section, crimp the inner and outer tip parts (2a), (2a) of the metal case (2) so as to face each other. Since the piezoelectric element (10) is fixed and held by pressing the inner and outer peripheral edges of the plate packing (5) with the housing hole (7) formed in the insulator (6) in advance, it is positioned in the manufacturing process. Can be arranged without checking the position, the accuracy is improved, and the piezoelectric element (10) can be prevented from swinging due to vibration. The piezoelectric element (10) may be pressure-bonded to the electrode plate (8) with a bonding agent such as silicon varnish in order to prevent the piezoelectric element (10) from being rocked. It is possible to ensure sufficient electrical continuity between the electrode plate and the electrode plate.
In addition, in order to seal the inside of the metal case (2) and maintain the insulation of the electrode plate (8) and the lead wire (11), silicon is provided in the inner and outer peripheral parts of the metal case (2) and the gaps in the protection tube (3). An insulating filler (12) such as resin is enclosed. Thus, when the pressure generated in, for example, the combustion chamber of the internal combustion engine is transmitted from the direction of the arrow in FIG. 3, the pressure strain is transmitted to the pressure element (10) through the case (2), where the upper electrode plate (converted into an electric signal ( 8) The diameter of 8) is transmitted to the control device by the lead wire (11).

(Effects of the Invention) As described above, the piezoelectric element is fitted and fixed in the accommodation hole formed in the insulating plate on the electrode plate, or the pressure element is fixed by the bonding agent to obtain a pressure sensor. Accuracy and required positioning become easier, and pressure bonding together with the bonding agent prevents rocking in the case due to vibration, etc., and a double insulating plate ensures insulation from the case. As a pressure sensor,
It has an excellent effect that the workability and durability are sufficient.

[Brief description of drawings]

1 is an overall perspective view of a gasket type pressure sensor according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of a pressure receiving body, and FIG. 3 is a sectional view taken along the line I--I of FIG. 1 ... Gasket type pressure sensor, 2 ... Case, 3 ...
… Lead wire, 4… Through hole, 5… Plate packing, 6, 9…
... Insulating plate, 7 ... Housing hole, 8 ... Electrode plate, 10 ... Block-shaped piezoelectric element

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-53-16614 (JP, A) Sekikai-Sho 61-114343 (JP, U) JP-B 52-9827 (JP, B2) JP-B Sho- 60- 26239 (JP, B2) JP 58-27459 (JP, B2)

Claims (2)

[Claims] 1. An insulative plate (6) on an annular electrode plate (8) is provided with a plurality of penetrating accommodating holes (7) located on a concentric circle centered on an axis, and accommodating the accommodating holes (7). One surface of the block-shaped element (10) formed by dividing the piezoelectric element is projected and accommodated in the hole (7), and the projected surface of the block element (10) is brought into contact with the annular plate packing (5). A gasket-type pressure sensor in which the electrode plate (8) is sandwiched between insulating plates (9) and enclosed in an annular metal case (2). 2. The gasket type pressure sensor according to claim 1, wherein an insulating filler is enclosed in a gap such as in the metal case (2).