JP3623831B2 - Measuring instrument structure such as engine tachometer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a measuring instrument structure such as a non-contact engine tachometer using an antenna lead wire.
[0002]
[Prior art]
Conventionally, automobiles and motorcycles have been provided with an engine tachometer that detects the engine speed and a odometer that serves as a guide for maintenance and inspection. Integrating usage hour meter that can be used as a guideline for engine maintenance check timing or lease fee calculation standards for mowers, chainsaws, etc. Is provided.
[0003]
The engine tachometer or the non-contact type tachometer as an example of the usage time meter and the usage time meter include a case in which the induction coil is incorporated so that the induction coil receives electromagnetic waves generated from the ignition system of the engine. A projecting portion provided with a plurality of through holes or the like for attaching one end of an antenna lead wire to the outside of the antenna is formed (refer to Japanese Utility Model Publication Nos. 7-9097 and 4-24110).
[0004]
[Problems to be solved by the invention]
The conventional non-contact type engine tachometer or usage time meter is used to cause the induction coil to receive electromagnetic waves generated from the ignition system of the engine. The reception sensitivity is improved as much as possible, but in that case, there is a limit due to the structure of the engine.
[0005]
Therefore, it is conceivable to make the induction coil large so that it can be received efficiently even at a location away from the electromagnetic wave generation source. In that case, a case (that is, an engine tachometer) incorporating the induction coil is considered. In addition, there is a problem in that the use time meter) is large, which increases the cost and cannot be installed in a predetermined space of the engine.
[0006]
Next, when using the antenna lead wire, it is necessary to attach one end of the antenna lead wire to the outside of the case containing the induction coil. Protrusions were formed on the side surfaces.
[0007]
Therefore, installation requires extra space in consideration of the protrusion formed on the outer surface of the case, and further requires a packaging container in consideration of the protrusion during packing or transportation. At the same time, the cost was increased.
[0008]
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 capable of attaching one end of an antenna lead wire to a case without the protruding portion.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the present invention according to claim 1 is configured to induce electromagnetic waves generated from an ignition system of an engine to an induction coil in a case, and to determine an engine speed and the like based on an induction output of the induction coil. In a measuring instrument such as a non-contact type engine tachometer for measuring and displaying, a thin portion having a triangular shape in plan view is provided at a corner portion in the outline of the case, and the thin portion and the original thickness portion of the case are provided. The induction coil is disposed along a linear boundary line that is a hypotenuse of the thin portion having a triangular shape in plan view, and one end of an antenna lead wire that is inductively coupled to the induction coil is disposed on the thin portion. Two or more through-holes for inserting the antenna lead wire so that the antenna lead wire does not protrude beyond the thickness of the case when the one end of the antenna lead wire is bent over the through-hole and inserted. Lee In which the line is attachable to the thin portion. Further, according to the present invention, the electromagnetic wave generated from the ignition system of the engine is guided to the induction coil in the rectangular parallelepiped case, and the engine speed and the like are measured and displayed based on the induction output of the induction coil. In a measuring instrument such as a non-contact type engine tachometer, a length that extends along a length direction of the longitudinal side surface portion and that does not reach a corner portion of the case is formed on the longitudinal side surface portion in the contour line of the case. A rectangular thin portion in plan view is provided, and along the linear boundary line between the thin portion and the original thickness portion of the case, which is the long side of the rectangular thin portion in plan view. An induction coil is provided, and the thin portion is provided with two or more through holes for inserting one end of an antenna lead wire that is inductively coupled to the induction coil, and the one end of the antenna lead wire is formed in the through hole. Bend across and insert The antenna lead is what the antenna leads so as not to protrude outside the thickness of the case is attachable to the thin portion when the.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described 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.
[0011]
The non-contact type engine tachometer A for measuring the engine speed shown in the drawing is provided with an induction coil 2 for inducing electromagnetic waves generated from an ignition system of the engine in a case 1 made of synthetic resin or the like. An operation unit (not shown) that performs waveform shaping based on the output of the induction coil 2 and counts and counts the waveform-shaped pulses, a display segment 3 that displays the engine speed that is the operation result, and the like are provided. Further, a window hole 4 through which the display segment 3 is viewed is provided.
[0012]
The present invention relates to a measuring instrument structure such as the engine tachometer A configured as described above, and one embodiment thereof is shown in FIG.
[0013]
In the present invention, the vicinity of the induction coil 2 provided in the casing 1, in the FIG. 1 embodiment the corner portions of the outline of the case 1, the top and bottom of the corner portion is removed to a suitable thickness obliquely A thin portion 1a having a triangular shape in plan view is formed. That is, the thin portion 1a is configured to have a thickness that prevents the antenna lead wire 5 from protruding outside the thickness of the case 1 when the antenna lead wire 5 described later is attached within the outline of the case 1. . Further, the induction coil 2 extends along a linear boundary line 20 between the thin portion 1a and the original thickness portion of the case, which is the hypotenuse of the thin portion 1a having a triangular shape in plan view. Further, the entire boundary line 20 is disposed in the case 1.
[0014]
In the present invention, two through holes 6 and 7 are provided in the thin portion 1a, and one end of the antenna lead wire 5 inductively coupled to the induction coil 2 provided in the case 1 is connected to the transparent portion. It is attached using the holes 6 and 7.
[0015]
Specifically, one end of the antenna lead wire 5 is inserted from below the through-hole 6 formed in the thin portion 1a and pulled upward, and further inserted from above the through-hole 7 to below. by slightly pulled out state, said antenna lead 5 is attached to the thin portion 1a.
[0016]
In addition, although the said through-holes 6 and 7 are shape | molded simultaneously at the time of shaping | molding of the said case 1, in the example of drawing, the number is made into two pieces, Three or more may be sufficient.
[0017]
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.
[0018]
The engine tachometer A of the present invention configured as described above can be connected to the engine ignition system, for example, a spark plug cable 10 by connecting the conductive connector 8 provided at the other end of the antenna lead wire 5 to the engine tachometer. Electromagnetic waves generated from the ignition system can be guided to the induction coil 2 in the case 1, and the engine speed and the like can be measured and displayed based on the induction output of the induction coil 2.
[0019]
That is, in the present invention, the attachment of the antenna lead wire 5 to the case 1 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 protrude outside the thickness of the case 1 within the outline of the case 1, a protruding portion is formed on the outer surface of the case 1 as in the case of a conventional engine tachometer. No protrusions are formed.
[0020]
Therefore, in the present invention, when installing the engine tachometer A, it can be installed in a small space of the internal combustion engine, and the cost can be reduced without requiring any trouble during packing or transportation. Since the thin portion 1a of the case 1 to which the antenna lead wire 5 is mounted is a corner, the allowable wiring direction range of the antenna lead wire 5 can be widened, and the wiring can be easily performed.
[0021]
FIG. 2 shows another embodiment of the engine tachometer A. The same components as those of the engine tachometer A described above are denoted by the same reference numerals.
[0022]
That is, in this embodiment, unlike the above-described embodiment, a thin portion 1b having a rectangular shape in plan view with an appropriate thickness removed from the upper and lower portions is formed on the longitudinal side surface portion 21 in the outline of the rectangular parallelepiped case 1. Has been. The thickness of the thin portion 1b is set such that the antenna lead wire 5 does not protrude outside the thickness of the case 1 even when the antenna lead wire 5 is attached . As shown clearly in FIG. 2, the thin portion 1 b extends along the longitudinal direction of the longitudinal side surface portion 21 and has a length that does not reach the corner portion of the case 1. Further, in this embodiment, the induction coil 2 is connected to a linear boundary line 22 between the thin portion 1b and the original thickness portion of the case 1 that is the long side of the thin portion having a rectangular shape in plan view. The boundary line 22 is disposed in the case 1 so as to extend along the entire length.
[0023]
And the two through-holes 6 and 7 are provided in this thin part 1b. Also in this embodiment, the mounting of the antenna lead wire 5 is the same as in the above embodiment.
[0024]
1 and 2 show an embodiment relating to the engine tachometer. In the case of an engine usage accumulator, the first display switching for switching to the display of the accumulated usage time from the beginning of use of the built-in engine. A switch, a second display changeover switch or the like for switching to a display of accumulated usage time from a point of time arbitrarily set by the user, and the like are provided on the surface of the case or the like (refer to the above-mentioned No. 4-24110).
[0025]
【The invention's effect】
According to the present invention, since no protruding portion is formed on the outer surface of the case as in the prior art, it can be installed in a small space of the internal combustion engine, and the cost can be reduced without requiring any trouble during packing or transportation. Furthermore, effects such as easy wiring of the antenna lead wire 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
2 Inductive coils 1a, 1b Thin portion 5 Antenna lead wires 6, 7 Through hole
20 border
21 Longitudinal side
22 Boundary line A Engine tachometer

Claims (2)

A non-contact engine that induces electromagnetic waves generated from the ignition system of the engine to the induction coil (2) in the case (1), and measures and displays the engine speed and the like based on the induction output of the induction coil (2). In a measuring instrument such as a tachometer, a thin portion (1a) having a triangular shape in plan view is provided at a corner portion in the outline of the case (1), and the original thickness of the thin portion (1a) and the case (1) is provided. The induction coil (2) is disposed along a linear boundary line (20) which is a hypotenuse of the thin-walled portion (1a) having a triangular shape in plan view, and the thin-walled portion (1a) Are provided with two or more through holes (6, 7) for inserting one end of an antenna lead (5) inductively coupled to the induction coil (2), and the one end of the antenna lead (5) is When the antenna is bent through the through holes (6, 7) Leads (5) said casing (1) of not protrude outside thickness as the antenna lead (5) is attachable to said thin portion (1a), instrumentation structure for an engine tachometer, etc. . Non-contact that induces electromagnetic waves generated from the ignition system of the engine to the induction coil (2) in the rectangular parallelepiped case (1), and measures and displays the engine speed based on the induction output of the induction coil (2). In a measuring instrument such as an engine tachometer, the case (1) extends to the longitudinal side surface (21) in the contour line of the case (1) along the longitudinal direction of the longitudinal side surface (21). A rectangular thin portion (1b) in a plan view having a length that does not reach the corner portion is provided, and the rectangular shape in a plan view between the thin portion (1b) and the original thickness portion of the case (1) is provided. The induction coil (2) is disposed along a linear boundary line (22) which is a long side of the thin thin part (1b), and the thin coil part (1b) is connected to the induction coil (2). Insert two ends of the antenna lead wire (5) to be inductively coupled Through-holes (6, 7), and when the one end of the antenna lead wire (5) is bent over the through-hole (6, 7) and inserted, the antenna lead wire (5) is inserted into the case ( A measuring instrument structure such as an engine tachometer, wherein the antenna lead wire (5) can be attached to the thin part (1b) so as not to protrude outside the thickness of 1).

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