JPS61209326A - Knocking sensor - Google Patents

Abstract

PURPOSE:To attain to enhance assembling workability, by forming an output terminal into an L-shape to embed the base part thereof in a connector and providing piercing holes corresponding to the output terminal and the connector while passing a lead wire through said piercing holes to connect the output terminal and the connector. CONSTITUTION:A plate shaped output terminal 7 is formed into an L-shape and a piercing hole 71 is provided to the base part of said L-shaped terminal. The piercing hole 61 corresponding to the piercing hole 71 is provided to the connector 6 integrally molded along with the output terminal 7 and the diameter of the hole 611 outside said hole 61 is made larger than that of the piercing hole 71 and the hole part 612 inside said hole 61 is formed into a tapered form so as to easily pass a lead wire 8. The lead wire 8 is made long to be passed through the piercing hole 61 and pulled so as to be prevented from the contact with a vibration plate 5 or a housing 1 and, after the lead wire 8 is fixed to the piercing hole 71, the piercing holes 61, 71 are closed by an insulating air- tight agent. By this method, assembling workability becomes well and the shortcircuit or disconnection of the lead wire can be prevented.

Description

[Detailed Description of the Invention] [Field of Industrial Application] In order to improve fuel efficiency, the present invention detects engine block vibration, determines the presence or absence of engine knocking from the vibration waveform, and performs ignition timing control. The present invention relates to a knock sensor used as a vibration hinge up for a knock control system.

[Conventional technology]

FIG. 4 shows a conventional knocking sensor (for example, Japanese Utility Model Application No. 57-39335). In Figure 4,
Reference numeral 1 denotes a cup-shaped housing having a threaded portion 11 for attachment to the engine, and on the inner bottom surface of this housing 1,
A protrusion 2 is formed. A central portion of a disc-shaped diaphragm 5 made of metal such as Kovar is fixed to this protrusion 2 by means such as welding. An annular piezoelectric body 3 having electrodes 31 and 32 with silver paste or the like baked on both surfaces is adhered to the diaphragm 5 with a heat-resistant adhesive or the like. The piezoelectric body 3 is made of piezoelectric ceramic such as lead zirconate titanate. The electrode 32 on one side of the piezoelectric body 3 is grounded to the housing 1 via the diaphragm 5 as described above. The other electrode 31 is connected to one end of the lead wire 8 by soldering or the like. The other end of the lead 'llA3 is connected to a through hole 7 of an output terminal 7 integrally formed with a connector 6 made of resin or the like.
1, it is soldered to the output terminal 7.

The connector 6 is attached to the open end of the housing 1 by means such as tightening.

[Problem that the invention seeks to solve]

By the way, in this configuration, the lead wire 8 needs to be connected to the output terminal 7 and the electrode 31 of the piezoelectric body 3 before the connector 6 is attached to the open end of the housing 1, so the length of the lead wire 8 is A length sufficient to solder the wire 8 to the through hole 71 of the output terminal 7 outside the housing 1 is required. However, if the length of the lead wire 8 is increased, the lead wire 8 contacts or wraps around the housing 1 and the diaphragm 5, resulting in a short circuit. Therefore, the lead wire 8 must be a wire covered with an insulating material.
Even if a coated wire is used, the coating of the lead wire 8 may rub against the diaphragm 5 and the housing 1 due to vibration, causing a break and short circuit, and in some cases, the lead wire 8 may be disconnected. Also, lead′! Since lA8 is long, there is a possibility that the lead wire 8 may get caught between the connector 6 and the housing l when the connector 6 is assembled to the housing 1. If the lead wire 8 gets caught in this way, the lead wire 8 may be disconnected or shorted. There is a possibility that Furthermore, if the lead wire 8 rests on or wraps around the diaphragm 5, there is a problem in that the vibration characteristics themselves are affected.

Therefore, the present invention solves the above-mentioned conventional problems, and at the same time improves the workability of the assembly, it also provides a stable structure without lead wire shorting or disconnection, and also provides vibration detection. The purpose is to obtain stable vibration characteristics of the body itself.

[Means for solving problems]

In order to achieve the above object, the present invention makes the output terminal L-shaped, embeds its base in the connector, and inserts a hole in the connector corresponding to the through hole formed at the base of the output terminal for passing the lead wire. A connector characterized in that through-holes are provided that penetrate through the outside, and after passing lead wires through these through-holes, the connector is connected by soldering, etc., and then the through-hole of the connector is closed with an insulating airtight material such as resin. It is.

[Effect]

This makes it possible to connect the lead wire to the output terminal after attaching the connector to the open end of the housing.
Moreover, the slack in the lead wire can be taken up before this connection.

〔Example〕

The present invention will be described below with reference to embodiments shown in the drawings.

In the first embodiment shown in FIG. 1, the housing 1, protrusion 2, piezoelectric body 3, and diaphragm 5 are the same as the conventional structure shown in FIG. The plate-shaped output terminal 7 is L-shaped (
A through hole 71 is provided in the base portion 7a which does not fit into an external connector (not shown). The details of the shape of the output terminal 7 are shown in FIG. The connector 6 is integrally molded with the base portion 7a of the output terminal 7 buried therein in a parallel direction, and has a through hole 61 that penetrates the inside and outside of the housing 1, corresponding to the through hole 71 of the output terminal 7. The shape of the through-hole 61 of this connector 6 is such that the hole 611 outside the base 7a of the output terminal 7 has a sufficiently larger diameter than the through-hole 71 of the output terminal 7 to facilitate soldering work, and the inside The hole 612 has a tapered shape whose diameter decreases toward the through hole 71 of the output terminal 7 so that the lead wire 8 can be easily passed through. However, the diameters of both holes 611 and 612 are made smaller than the width of the output terminal 7 so as not to protrude beyond the output terminal 7.

One end of the lead wire 8 is fixed to the electrode 31 of the piezoelectric body 3, and the other end is fixed to the through hole 71 of the output terminal 7 by means of soldering or the like, so that they are electrically conductive. Here, to fix the lead wire 8 and the through hole 71 portion of the output terminal 7, the lead wire 8 is
Then, insert the lead vA through the through hole 71 of the connector 6.
This is done after assembling the connector 6 to the open end of the housing 1 by pulling it to the extent that the connector 8 does not touch or bite the diaphragm 5 and the housing 1. After that, the excess portion of the lead wire 8 is cut off. With the above configuration, the lead wire 8 does not come into contact with the housing 1 or the diaphragm 5, so it does not need to be a coated wire. 10 is molded by injecting and filling an insulating and airtight material such as resin so as to close the hole 611 on the outside of the connector 6.

Furthermore, a protrusion 62 that is formed integrally with the connector 6 surrounding the protrusion at the tip of the output terminal 7 and that fits into an external connector is provided eccentrically as shown in the figure, so that the protrusion 62 penetrates the connector 6. A space for providing the hole 61 can be easily obtained, and the device is compact.

To explain the operation of this embodiment, vibrations caused by engine knocking are transmitted to the housing 1 fixed to the engine block by the threaded part 11, the vibrations are transmitted to the diaphragm 5, and the piezoelectric body 3 generates an electric current corresponding to the vibrations. Convert to signal. This converted signal is taken out to the outside via the electrode 31, lead wire 8, and output terminal 7.

Next, a second embodiment shown in FIG. 4 will be described. The second embodiment has the same basic structure as the first embodiment, and the hole portion 6 inside the through hole 61 of the connector 6
The difference is that a rubber bushing 9 is press-fitted into the rubber bushing 9, and the lead wire 8 is drawn out through a through hole 9a, which has a slightly smaller diameter than the lead wire 8 provided at the center of the rubber bushing 9.

The rubber bushing 9 makes it possible to seal between the lead vA8 and the hole 612 inside the through hole 61 of the connector 6.
This creates a double seal with the insulating airtight material (botting material) lO. In addition, in the first embodiment, since there is no bushing 9 inside the terminal, an insulating airtight material 10 with low fluidity is required, whereas in the second embodiment, a rubber bushing 9 is used, so that when the insulating airtight material 10 is injected, the rubber bushing 9 is used. Since the sealability is ensured, it becomes possible to use the insulating airtight material 10 with good fluidity and high sealability.

Furthermore, in the first embodiment, in order to prevent the lead wire 8 from coming off from the through hole 71 of the output terminal 7 when the excess portion of the lead wire 8 is cut off, the tip of the lead wire 8 is bent and the output terminal is However, in the second embodiment, even when the excess portion of the lead wA8 is cut off, the hole 9a of the rubber bush 9 is connected to the hole 9a of the rubber bush 9.
Since the tip of the lead wire 8 is held in the through hole 71 of the output terminal 7 due to the frictional resistance between the lead wire 8 and the lead wire 8, soldering is possible without bending the tip of the lead wire 8. .

In each of the above-described embodiments, the lead wire 8 is connected to the output terminal 7 and the piezoelectric body 3 by soldering, but the lead wire 8 may be connected by welding, conductive adhesive, or the like.

〔Effect of the invention〕

With the above configuration, the present invention improves the workability of assembly, eliminates the possibility of short-circuiting or disconnection of the lead wires, and eliminates the negative effects of the lead wires on the vibration detector, resulting in stable and stable assembly. It has an excellent effect of providing high performance.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing a first embodiment of the sensor of the present invention, FIG. 2 is a perspective view showing the output terminal of the sensor shown in FIG. 1, and FIG. 3 is a longitudinal cross-sectional view showing a second embodiment of the sensor of the present invention. side view,
FIG. 4 is a longitudinal sectional view showing a conventional sensor. ■... Housing, 3.5... Piezoelectric body and diaphragm constituting the vibration detection body, 6... Connector, 7... Output terminal. 7a...Base, 8...Lead wire, 10...Insulating airtight material. 61.71...Through hole.

Claims (1)

[Claims] In a knocking sensor in which a vibration detector is fixed in a housing and an insulating connector is attached to an open end of the housing, an L-shaped output terminal whose base is embedded in the connector, and an L-shaped output terminal formed at the base of the output terminal are provided. a through hole formed in the connector corresponding to the through hole, and a lead wire having one end connected to the base of the output terminal and the other end connected to the vibration detector through these through holes. and an insulating airtight body that closes the through hole of the connector.