JPH0240506Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a knob sensor with a rotation stopper.
In particular, when installing the knock sensor in the engine part, it can be installed without requiring any operation to prevent the lock sensor from drifting, and it can also avoid contact of the lead wire with various parts of the engine, improving work efficiency and preventing breakage and disconnection of the lead wire. The present invention relates to a knob sensor with a rotation stopper designed to prevent rotation.

[Technical background of the invention]

The so-called knotting occurs when unburned gas is compressed and ignited and combusts rapidly, forcing the cylinder wall to vibrate.
This causes a sudden rise in pressure and temperature, which in severe cases can lead to melting and damage to valves, pistons, etc. Therefore, in order to prevent knocking, the shape of the combustion chamber and the position of the spark plug are devised to suppress the occurrence of knocking, and there are engines that are equipped with so-called knock sensors to detect knocking at an early stage and take countermeasures.

[Problems with background technology]

Conventionally, a knock sensor is formed in the shape of a washer-like ring plate with a fixing hole provided in the center. In the case of an air-cooled internal combustion engine, the knock sensor is installed by inserting the fixing hole of the knock sensor into a stud bolt of a cylinder block that passes through the cylinder head of the engine, and then tightening the nut. Alternatively, in the case of a water-cooled internal combustion engine, a head bolt that fixes the cylinder head, which is the engine part, to the cylinder block is inserted into the fixing hole of the knock sensor, and the knock sensor is attached by tightening the head bolt.

However, there was a problem in that the knob sensor also rotated when the nut or head bolt was rotated when tightening. For this reason, when installing the knock sensor in the engine part, it is necessary to tighten the sensor while holding it with tweezers, a screwdriver, etc., and this requires an operation to prevent looseness, which makes the work complicated and reduces work efficiency. There was an inconvenience. Furthermore, when the knock sensor rotates when installed, the output lead wire also rotates and comes into contact with heat dissipation fins of the cylinder head, camshaft block, etc. that constitute various parts of the engine. Therefore, there was a risk that the lead wire would be damaged or disconnected.

[Specific purpose of the idea]

Therefore, this idea solves this problem and
When the knock sensor is installed in the engine part, the locking part that comes into contact with each part of the engine prevents the knock sensor from shifting due to the tightening of fasteners, and the lead wire is located at a distance from each part of the engine. As a result, the lock sensor can be installed without having to perform an operation to prevent it from drifting. Also, by preventing the lock sensor from moving, it can be installed without paying attention to the contact of the lead wire with various parts of the engine. The object of the present invention is to realize a knob sensor with a rotation stopper that can sufficiently avoid rotation, improve work efficiency, and reliably prevent breakage and disconnection of lead wires.

[Structure of the idea]

In order to achieve this objective, this invention has been developed to connect a lead wire outlet of a piezoelectric element built into the case of the knock sensor to the case of the knock sensor in the form of an annular thick plate that is attached to the engine part using a fastener. A holder for the lead wire is provided by bending the extended tip of the outlet portion in parallel with the axial direction of the knock sensor, and the lead wire is provided in a way that it projects in the diametrical direction of the knock sensor, and is brought into contact with various parts of the engine to secure the knock sensor. The lead wire is constructed of a support member that protrudes like a flange from the outlet portion in order to prevent the lead wire from floating and to position the lead wire away from each part of the engine, and an abutment member that is installed between the support member and the case. It is characterized by having a frame-shaped locking part.

[Example of idea]

Next, an embodiment of this invention will be described in detail based on the drawings.

1 to 4 show examples of this invention. The knock sensor 2 is as shown in FIG.
A piezoelectric element 4 for electrically detecting knocking is built into the case 6, and a fixing hole 8 for mounting on the engine is provided.
It is formed in the shape of a washer-like ring plate. As shown in FIG. 1, the case 6 is provided with an outlet 10 projecting in the diametrical direction integrally with the case 6. Outlet portion 1 formed integrally with this case 6
0, the output lead wire 12 of the piezoelectric element 4 is led out to the outside. As shown in FIG.
Two holders 30 are provided. This outlet 10
The support member 32 is provided in a flange-like manner so as to intersect with the direction in which the outlet portion 10 projects, and the outlet portion 1 is provided between each protruding end of the support member 32 and the case 6.
Abutment members 34 are installed parallel to the direction in which the 0 protrudes, and a frame-shaped locking portion 36 is provided, thereby forming a rotation-preventing knob sensor.

In the knock sensor 2 of this embodiment, as shown in FIG. 3, the abutting member 34 of the locking portion 36 is aligned with the side surface 38 of the camshaft block 22, and the stud bolt 18 is fitted into the fixing hole 8. When the knob sensor 2 is installed by rotating and tightening the nut 26, the contact member 34 is attached to the camshaft block 22.
is held in that position by abutting the side surface 38 of.

As a result, the knock sensor 2 is prevented from floating, and the lead wire 12 is located apart from the heat radiation fin 20, camshaft block 22, etc. of each part of the engine. Therefore, since the rotation of the knock sensor 2 is prevented, there is no need to perform a movement prevention operation of pressing the knock sensor 2 with a screwdriver or the like to prevent rotation when the knock sensor 2 is installed. There is no need to be careful about contact with various parts of the engine, the installation work can be facilitated, work efficiency can be improved, and damage and disconnection of the lead wire 12 due to contact can be prevented. Further, according to this embodiment, since the lead wire 12 is positioned apart from the camshaft block 22 by the frame-shaped locking portion 36, contact of the lead wire 12 with various parts of the engine can be sufficiently avoided. Therefore, damage and disconnection of the lead wire 12 due to contact with various parts of the engine can be more reliably prevented.

[Effect of idea]

As described above, according to this invention, the locking portion of the lock sensor is brought into contact with and locked to each part of the engine, so that the lock sensor is prevented from moving during a fastening operation, and the lead wire is positioned at a distance from each part of the engine. Therefore, the knock sensor can be mounted without requiring an operation to prevent the knock sensor from drifting, and without being careful about the lead wire coming into contact with various parts of the engine due to the drift, so that the mounting work can be facilitated and work efficiency can be improved. Further, by locating the lead wire apart from each part of the engine, contact of the lead wire with each part of the engine can be sufficiently avoided, and breakage or disconnection of the lead wire can be reliably prevented.

[Brief explanation of the drawing]

Figures 1 to 4 show examples of this invention;
2 is a plan view and a side view of the knob sensor with a rotation stopper, FIG. 3 is a plan view showing the installed state, and FIG. 4 is an enlarged sectional view taken along the line -- in FIG. In the figure, 2 is a knock sensor, 6 is a case,
10 is an outlet, 12 is a lead wire, 16 is a cylinder head, 18 is a stud bolt, 20 is a heat radiation fin, 22 is a camshaft block, 32 is a support member, 34 is a contact member, and 36 is a locking portion. .

Claims (1)

[Scope of utility model registration request] In a knob sensor in the form of a thick circular plate that is attached to an engine part by a fastener, an outlet of a lead wire of a piezoelectric element built into a case of the knock sensor is made to protrude in the diametrical direction of the knock sensor integrally with the case. At the same time, a holder for the lead wire is provided by bending the extended tip of the outlet in parallel to the axial direction of the knock sensor, and a holder is provided for the lead wire, which comes into contact with various parts of the engine to prevent the knock sensor from moving, and also connects the lead wire to each part of the engine. A frame-shaped locking portion is provided at the outlet portion to be located apart from the case, and the frame-shaped locking portion includes a support member projecting like a flange and an abutment member installed between the support member and the case. Features a lock sensor with a rotation stopper.