JPH0334699Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a portable engine revolution meter, and in particular, the portable hanging string also functions as an antenna lead, so that there is no need to prepare a separate antenna lead. It is characterized by being able to capture electromagnetic waves generated from the engine's ignition system with high sensitivity, and being portable and inexpensive.

[Conventional technology]

A portable engine revolution meter is a device that guides electromagnetic waves generated from the engine's ignition system to an internal induction coil, and displays the engine revolution speed on a display based on the induced output, making it convenient to carry. For this purpose, a hanging string was provided for carrying. That is, a portable engine revolution meter a as shown in FIG.
was provided.

In Fig. 4, reference numerals 1 and 2 are two upper and lower outer casings that house an electric circuit section and an induction coil (not shown), and a display 4 faces into a window hole 3 provided in the upper outer casing 1. , these constitute the main body 5. The induction coil is for inducing electromagnetic waves generated from the ignition system of the engine, for example, the spark plug 6 of the engine, and is connected to the electric circuit section.

Reference numeral 7 denotes an antenna lead that can be attached to and detached from the main body 5, and is configured to be inductively coupled to the induction coil when attached to the main body 5. That is, the antenna lead 7 is made of copper wire or the like, and one end is provided with a conductive connector 8 such as an alligator clip, and the other end is provided with a plug 10 that can be inserted into and pulled out from a jack 9 provided on the main body 5. It is provided. The jack 9 is wired inside the main body 5 close to the induction coil, so that when the plug 10 is inserted into the jack 9, the antenna lead 7 and the induction coil are inductively coupled.

Furthermore, 11 is a portable hanging string, and the main body 5
It is attached to the camera for convenience when carrying.

According to the conventional portable engine tachometer configured as described above, the antenna lead 7 is attached to the main body 5, and the connector 8 of the antenna lead 7 is held between the insulating coating 12 of the conductor of the engine spark plug 6. As a result, electromagnetic waves corresponding to the engine speed emitted by the conductor are transmitted to the antenna lead 7 through the connector 8.
is further induced into the induction coil, and the induced signal is amplified in the electric circuit section.
The engine speed was calculated and displayed on the display 4.

Therefore, the detection sensitivity of electromagnetic waves by the induction coil is improved, and as a result, the engine speed can be accurately displayed.

Also, when carrying, the antenna lead 7 is connected to the main body 5.
Since the main body 5 is detached from the main body and carried separately, and the main body 5 is provided with a hanging string 11, it is convenient to carry the main body 5.

However, in the above-mentioned conventional portable engine revolution meter a, the antenna lead 7 is
Since it is carried separately from the main body 5, it is inconvenient to handle the antenna lead 7 when carrying it, and there is a risk that the antenna lead 7 may be lost. In addition, an antenna lead 7 and a portable hanging string 11 are also included.
Since these are prepared separately, the disadvantage is that the costs inevitably increase.

[Problem that the invention attempts to solve]

The present invention eliminates the drawbacks of the prior art described above, and can capture electromagnetic waves generated from the engine's ignition system with high sensitivity without the need for a separate antenna lead, and is convenient and inexpensive to carry. The purpose of this project is to provide a portable engine revolution meter that can be used.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention constructs a hanging string using a conductive material, and provides a removable engagement part on the main body at one end of the hanging string. It is characterized in that the end is engaged and fixed to the main body side and inductively coupled to an induction coil provided inside the main body.

[Effect]

According to the present invention having the above configuration, when measuring the engine rotation speed, the engaging part provided at one end of the hanging string is removed from the main body, and one end of the hanging string is connected to the ignition system of the engine. For example, it is placed in close proximity to the conductor sheathing of an engine's spark plug. The hanging string is made of a conductive material, and the other end of the hanging string is inductively coupled to the induction coil provided inside the main body by being engaged with the main body. It has exactly the same effect as the antenna lead in .

Furthermore, when carrying the device, the engaging portion of the hanging string that has been removed as described above is attached to the main body. Therefore, the hanging string can be conveniently carried when being carried like the hanging string in the above-mentioned prior art.

〔Example〕

In the drawings, reference numeral b designates a portable engine tachometer according to the present invention, which is composed of a main body 21 and a portable hanging string 22 attached to the main body 21.

In the figure, 23 and 24 are two upper and lower outer casings that house an electric circuit section and an induction coil (not shown).A display 26 faces a window hole 25 provided in the upper outer casing 23. constitutes the main body 21. The induction coil is for inducing electromagnetic waves generated from the ignition system of the engine, for example, the spark plug 6 of the engine, and is connected to the electric circuit section.

Furthermore, in the present invention, the portable hanging string 22 is made of a conductive material, such as a copper wire covered with an insulating coating. Further, the hanging string 22 is inductively coupled to the induction coil, and an engaging portion 27 is provided at one end of the hanging string 22 to be detachably attached to the main body 21.

In the case of the embodiment shown in the drawings, a notch 28 is provided inside the corner of the main body 21, and a cylindrical part 29 is provided in the notch 28.
The engaging part 27 of the hanging string 22 is detachably attached to the cylindrical part 29. In the case of the embodiment shown in the drawings, the engaging part 27 is configured by an annular part 30 and an opening part of the annular part 30 being closed by a movable piece 32 pressed by a spring 31, as shown in the third figure. , the annular portion 30 is opened by sliding the movable piece 32, and is configured to be attachable to and detachable from the cylindrical portion 29.

In addition, in the case of the embodiment shown in the drawings, an annular engagement portion 33 is provided at the other end of the hanging string 22, and the engagement portion 33
is engaged and fixed to the cylindrical portion 29 and cannot be removed. However, the engaging portion 33
As with the above-mentioned engaging portion 27, it may be configured to be detachable. The engaging portion 33 is made of a conductive material, and the main body 21
The inner surface 28a of the notch 28 is formed into an arc shape, and a suitable lead wire (not shown) is provided along the inner side of the main body 21 of the inner surface 28a, and the lead wire etc. extends to the vicinity of the induction coil. The suspension string 22 and the induction coil are inductively coupled to each other.
However, the hanging string 22 may be directly connected to the wiring inside the main body 21 and inductively coupled to the induction coil without providing the engaging portion 33.

As mentioned above, the cylindrical part 29 is formed inside the corner of the main body 21 and the hanging string 22 is attached to the main body 21, but the hanging string 22 and the induction coil are directly or indirectly induced. If it is possible to connect the hanging string 22 to the main body 21 by other means,
It can be attached to.

According to the present invention having the above configuration, when measuring the engine speed, the engaging part 27 provided at one end of the hanging string 22 is removed from the cylindrical part 29 of the main body 21, as shown in the second figure. Then, the engaging portion 27 is engaged with the insulating coating 12 of the conductor of the spark plug 6 of the engine, or the engaging portion 27 side of the hanging string 22 is tied. As mentioned above, the suspension string 22 is made of a conductive material and is inductively coupled to the induction coil, so that it corresponds to the engine rotational speed generated by the insulated conductor wire 12, just like the antenna lead 7 in the prior art described above. Electromagnetic waves hang from string 2
2 into the induction coil. Then, the electric circuit section amplifies and arithmetic processes the induced signal, and displays the engine rotation speed on the display 26.

In addition, data such as engine rotational malfunction, ignition irregularity, etc. can also be displayed on the display 25 using this guidance signal.

Therefore, the detection sensitivity of electromagnetic waves by the induction coil can be improved without providing any special antenna lead, and as a result, the engine speed can be accurately displayed.

Further, when carrying the device, the engaging portion 27 of the removed hanging string 22 is engaged with the cylindrical portion 29 of the main body 21, as shown in the first figure. Therefore, the hanging string 22 can provide convenience when being carried, similar to the hanging string 7 in the prior art described above.

[Effect of idea]

According to the present invention, the portable hanging string also acts as an antenna lead, making it possible to capture electromagnetic waves generated from the engine's ignition system with high sensitivity without the need for a separate antenna lead, making it convenient for carrying. The effect can be obtained at low cost.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a perspective view showing the state when being carried, Fig. 2 is a perspective view showing the state when measuring the engine rotation speed, and Fig. 3 is a perspective view showing the state when the engine rotation speed is being measured. FIG. 4 is a front view showing the part, and FIG. 4 is a perspective view showing a conventional example. 21...Main body, 22...Hanging string, 27...
Engagement part, b...Portable engine revolution meter.

Claims (1)

[Scope of utility model registration request] The hanging string is constructed using a conductive material, and one end of the hanging string is provided with an engaging part that can be attached to and detached from the main body, and the other end of the hanging string is engaged and fixed to the main body side, so that the hanging string can be attached to the main body. A portable engine revolution meter characterized by being inductively coupled to an internal induction coil.