JPH09113522A - Instrument structure of engine tachometer or the like - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an instrument such as an engine tachometer capable of fitting one end of an antenna lead wire to a case without any projecting part. SOLUTION: In an instrument such as a non-contact type engine tachometer, two or more through holes 6, 7 in which one end of an antenna lead wire 5 to be inductively coupled with an induction coil 2 is inserted are provided in a thin-walled part 1a so that the antenna lead wire 5 which is bent and inserted in the vicinity of an induction coil 2, within a contour of a case 1, and over the through holes 6, 7 is not projected out of the thickness of the case 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring instrument structure such as a non-contact type engine tachometer using an antenna lead wire.

[0002]

2. Description of the Related Art Conventionally, automobiles, motorcycles, etc. are provided with an engine tachometer for detecting the number of revolutions of an engine, a odometer as a guide for maintenance and inspection, and for a non-running device such as a mower or a chain saw. By detecting and displaying the total accumulated time from the beginning of use of the engine and the accumulated accumulated time from any set time, it can be used as a guideline for the maintenance and inspection time of the engine, or the lease fee calculation standard for mowers, chain saws, etc. A cumulative total time meter is provided.

A non-contact type tachometer and a usage cumulative time meter as an example of the engine tachometer or the usage cumulative time meter are provided with an induction coil for receiving an electromagnetic wave generated from an ignition system of the engine. The protruding portion is provided with a plurality of through holes for attaching one end of the antenna lead wire to the outside of the built-in case (actual fairness 7-909).
No. 7, Japanese Utility Model Publication No. 4-24110, etc.).

[0004]

SUMMARY OF THE INVENTION The conventional non-contact type engine tachometer or use-integrated time meter described above has an induction coil that receives an electromagnetic wave generated from an ignition system of an engine. The closer it is to the electromagnetic wave generation source, the more the receiving sensitivity is improved, but in that case, there was a natural limit in terms of the structure of the engine.

Therefore, it is conceivable to make the induction coil large so as to receive efficiently even at a place distant from the electromagnetic wave generation source. In that case, a case where the induction coil is built in (that is, The engine tachometer or the total operating time meter) is also large, which causes a cost increase and cannot be installed in a predetermined space of the engine.

Next, when the antenna lead wire is used, it is necessary to attach one end of the antenna lead wire to the outside of the case containing the induction coil, and the attaching portion is projected as described above. The protrusion was formed on the outer surface of the case.

[0007] Therefore, at the time of its installation, an extra space considering the protrusion formed on the outer surface of the case is required, and a packaging container considering the protrusion is required at the time of packaging or transportation. This required labor and increased costs.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a measuring instrument structure such as an engine tachometer in which one end of an antenna lead wire can be attached to a case without the protruding portion. .

[0009]

In order to solve the above-mentioned problems, the present invention guides an electromagnetic wave generated from an ignition system of an engine to an induction coil in a case, and rotates the engine based on an induction output of the induction coil. In a non-contact type engine speed measuring instrument for measuring and displaying the number and the like, two or more through holes for inserting one end of an antenna lead wire inductively coupled to the induction coil are provided near the induction coil. The antenna lead wire, which is bent and inserted in the contour line of the case and across the through hole, is provided in a thin portion configured so as not to project outside the thickness of the case.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a partially cutaway perspective view of an engine tachometer as an example of a measuring instrument structure according to the present invention, and FIG. 2 is a partially cutaway perspective view of an engine tachometer showing another embodiment.

In the non-contact type engine tachometer A for measuring the engine speed shown in the drawings, an induction coil 2 for inducing an electromagnetic wave generated from an engine ignition system is provided inside a case 1 made of synthetic resin or the like. A calculation unit (not shown) that performs waveform shaping based on the output of the induction coil 2 and counts and counts the waveform-shaped pulses, and a display segment 3 that displays the engine speed as the calculation result.
And the like, and a window hole 4 through which the display segment 3 can be seen.

The present invention relates to a structure of a measuring instrument such as the engine tachometer A having the above-mentioned construction, and one embodiment thereof is shown in FIG.

In the present invention, the vicinity of the induction coil 2 provided in the case 1, that is, the corner portion of the case 1 in FIG. 1 embodiment, the upper and lower portions of the corner portion are obliquely removed with an appropriate thickness, A thin portion 1a having a substantially triangular shape is formed. That is, the thinned portion 1a is inside the outline of the case 1 and when the antenna lead wire 5 described later is attached,
The antenna lead wire 5 has a thickness that does not project outside the thickness of the case 1.

In the present invention, the thin portion 1a has two
The through holes 6 and 7 are provided, and one end of the antenna lead wire 5 that is inductively coupled to the induction coil 2 provided in the case 1 is attached using the through holes 6 and 7.

That is, specifically, the through hole 6 is formed in the thin portion 1a at one end of the antenna lead wire 5.
Of the antenna lead wire 5 by inserting the antenna lead wire 5 from below and pulling it upward, and inserting it from above the through hole 7 and pulling it out slightly downward.
Mounted to.

The through holes 6 and 7 are formed at the same time when the case 1 is formed. In the illustrated embodiment, the number is two, but three or more. Good.

In the figure, 8 is a conductive connector such as an alligator clip provided at the other end of the antenna lead wire 5, 9 is a spark plug, and 10 is a spark plug cable.

In the engine tachometer A of the present invention constructed as described above, a conductive connector 8 provided at the other end of the antenna lead wire 5 is connected to an engine ignition system, for example, a spark plug cable 10. Inducing electromagnetic waves generated from the ignition system of the engine to the induction coil 2 in the case 1,
The engine speed and the like can be measured and displayed based on the induction output of the induction coil 2.

That is, according to the present invention, the antenna lead wire 5 is attached to the case 1 in a state where the antenna lead wire 5 is bent and inserted through the through holes 6 and 7 provided in the thin portion 1a of the case 1, specifically, Since the antenna lead wire 5 does not project inside the outline of the case 1 and outside the thickness of the case 1, as in the case of the conventional engine tachometer, the outer surface of the case 1 is No protrusions or protrusions are formed on the.

Therefore, according to the present invention, when the engine tachometer A is installed, it can be installed in a small space of the internal combustion engine, and the cost can be reduced without the need for packing or transportation. Since the thin portion 1a of the case 1 on which the antenna lead wire 5 is mounted is used as a corner, the wire routing direction allowable range of the antenna lead wire 5 can be widened and the routing can be facilitated.

FIG. 2 shows another embodiment of the engine tachometer A. The engine tachometer A described above
The same components as those are denoted by the same reference numerals.

That is, in this embodiment, unlike the above-described embodiment, when the upper and lower portions are appropriately removed in thickness from the side surface of the case 1, and the antenna lead wire 5 is attached within the contour line of the case 1. Also, a thin portion 1b having a thickness such that the antenna lead wire 5 does not project outside the thickness of the case 1 is formed.

Then, two through holes 6, 7 are formed in the thin portion 1b.
Is provided. Also in this embodiment, the attachment of the antenna lead wire 5 is the same as in the above embodiment.

Although FIGS. 1 and 2 show the embodiments relating to the engine tachometer, in the case of the engine integration meter, the display is changed to display the usage integration time from the beginning of use of the built-in engine. The display changeover switch of No. 2 and the second display changeover switch for changing over to the display of the accumulated use time from the time arbitrarily set by the user are provided on the surface portion of the case or the like (see the above-mentioned Japanese Utility Model Publication No. 4-24110).

[0025]

EFFECTS OF THE INVENTION According to the present invention, since the projecting portion is not formed on the outer side surface of the case as in the conventional case, it can be installed in a small space of the internal combustion engine, and at the same time, it does not require labor during packing or transportation and cost reduction. Can be lowered, and further, the effect that the wiring of the antenna lead wire is easy can be obtained.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view of an engine tachometer as an example of a measuring instrument structure according to the present invention.

FIG. 2 is a partially cutaway perspective view of an engine tachometer showing another embodiment.

[Explanation of symbols]

 1 Case 1a, 1b Thin part 5 Antenna lead wire 6, 7 Through hole A Engine tachometer

Claims (1)

[Claims] 1. An electromagnetic wave generated from an ignition system of an engine is guided to an induction coil (2) in a case (1), and the engine speed and the like are measured and displayed based on the induction output of the induction coil (2). In a measuring instrument such as a non-contact type engine tachometer, two or more through holes (6) (7) into which one end of an antenna lead wire (5) inductively coupled to the induction coil (2) is inserted, The antenna lead wire (5) which is bent and inserted near the induction coil (2) in the contour line of the case (1) and across the through holes (6) and (7) has a thickness of the case (1). A structure of a measuring instrument such as an engine tachometer, which is provided in a thin portion (1a) configured not to project outside.