[0001] This invention relates to a time totaling meter which can be used for maintenance
and repair of working machines driven by an internal combustion engine such as chain
saws, weed cutters and the like.
[0002] Heretofore, working machines such as chain saws and weed cutters driven by an internal
combustion engine have not been installed with a time totaling meter or equivalent
such as is being used for maintenance and repair of a four-wheeled vehicle, a motor
bicycle and the like. Therefore, for said working machines or internal combustion
engines, a cumulative operated time cannot be determined.
[0003] Maintenance and repair of said working machines and internal combustion engines are
being made at an interval and frequency decided by its user or not being made at all.
Consequently, there were several problems, due to inadequate maintenance and repair
of said working machines and internal combustion engines; they cannot be used due
to unexpected trouble, or broken parts causes accident involving human life, for example.
[0004] On the other hand, an attachable/detachable type of time totaling meter, which will
be used attached to a working machine itself, was proposed e.g. in JP-U-24110/1992
in order to avoid inadequate or incomplete maintenance and repair as mentioned above.
According to this proposal, total time from initiation of operation of working machines
and internal combustion engines can be counted and stored in a memory and further
can be displayed.
[0005] Such attachable/detachable type of time totaling meter may be intentionally or unintentionally
removed from said working machines by their users. Therefore, in case such time totaling
meter was detached and again attached to the working machine, total operation time
of the working machine without the time totaling meter is not added to the actual
cumulative operation time of the working machine, and therefore counted, stored and
displayed cumulative operation time does not reflect the actual cumulative operation
time of said working machines and internal combustion engine from their initial operation.
This is a problem for the attachable/detachable type of time totaling meter.
[0006] According to the present invention, there is provided a time totaling meter as claimed
in claim 1.
[0007] A preferred feature of the present invention is to provide a time totaling meter
for internal combustion engines capable of accurately counting, storing and displaying
only total time during which an internal combustion engine of a working machine has
been operated, allowing to do appropriately maintenance and repair of said working
machine and internal combustion engine based on data of said cumulative operation
time, and capable of being constructed simply and at low cost.
[0008] Another preferred feature of the present invention is to provide a time totaling
meter for internal combustion engines capable of counting independently total operation
time of an internal combustion engine from an arbitrarily selected time point in addition
to total operation time from the start of initial operation and displaying these by
choice.
[0009] A further preferred feature of the present invention is to provide a time totaling
meter for internal combustion engines capable of allowing to make a whole shape compactly
and to reduce manufacturing cost.
[0010] Another preferred feature of the present invention is to provide a time totaling
meter for internal combustion engines capable of implementing quickly and accurately
an electrical connection to an ignition circuit of an ignition device.
[0011] An additional preferred feature of the present invention is to provide a time totaling
meter for internal combustion engines capable of realizing the connection of cables
from a unit block to the time totaling meter in a small occupation space and also
capable of realizing to place it in a small package because it is not necessary to
form any convex region on the surface.
[0012] A further preferred feature of the present invention is to provide a time totaling
meter capable of displaying total operation time of an internal combustion engine
based on its revolution number by picking up electromagnetic wave from a high tension
cable into an induction coil via an antenna lead and also capable of realizing treatment
of said antenna lead in a small occupation space.
[0013] According to another aspect of the present invention there is provided a part of
an ignition device to lead ignition pulses toward the outside of the ignition device,
pulse induction means to have electromagnetically induced therein ignition pulses
flowing in said part of said ignition device, waveform shaping means to shape a pulse
waveform electromagnetically induced in said pulse induction means, and judging means
to distinguish output pulses of said waveform shaping means generated by the internal
combustion engine from other sources, wherein total operation time of said internal
combustion engine from its initial operation is counted and stored in count memory
means based on said output pulses distinguished by said judging means and thus counted
operation time by said count memory means is displayed on display means.
[0014] Preferably, in the time totaling meter by electrical connection of a part of the
ignition device in the working machine via a connector, the pulse induction means
can detect ignition pulses flowing in a part thereof and the judging means can select
only pulses having the same shape and the same time length from the others, the count
memory means can accurately count and store the cumulative time from the initial operation
of the internal combustion engine and this value is displayed.
[0015] Further, judging means may be provided which can distinguish only pulses derived
from the driving internal combustion engine from all wave shaped output pulses electrically
induced in the pulse induction means. Based on these output pulses, a first count
memory means can count and store total operation time of the internal combustion engine
from its initial operation, and a second count memory means, when user manipulated
re-set means is operated at an arbitrary time point, can start to count and store
total operation time of the internal combustion engine. And said first and second
count memory means display the stored operation time.
[0016] Therefore, in this time totaling meter for internal combustion engines, total operation
time from the initial operation is accurately counted, stored and displayed by the
first count memory means, and when a user manipulates the re-set means, the second
count memory means accurately count, store and display total operation time from the
time point arbitrarily set by the user.
[0017] Furthermore, a part of the ignition device is preferably mounted on the printed wiring
board where the pulse induction means and the pulse treatment circuit to treat pulses
induced in said pulse infarction means are also provided. Therefore, in this time
totaling meter for internal combustion engines, two printed wiring boards are not
always necessary so that the main body of the time totaling meter can be made compact
and at low cost.
[0018] In addition, a part of the ignition device may be connected to an intermediate point
of a circuit introducing induced voltage, obtained at an induction coil, to a charge/discharge
ignition capacitor via attachable/detachable connectors.
[0019] Therefore, in this time totaling meter for an internal combustion engine, electrical
and mechanical connection of the main body of the time totaling meter to the ignition
circuit of the working machine can be made accurately and simply by connection operation
of said connectors. Further, the time totaling meter preferably comprising pulse induction
means, waveform shaping means, judging means, count memory means and display means
may be formed in one body with the ignition device for the internal combustion engine
by injection molding or encapsulation using synthetic resin.
[0020] Therefore, in this time totaling unit for internal combustion engines, these parts
formed in one body can be handled as a unit block so that a whole ignition control
system for internal combustion engines can be made compact and reliability thereof
can be improved.
[0021] Furthermore, the time totaling meter is preferably provided with first and second
count memory means to count and store the number of output signals from the waveform
shaping means, re-setting means to re-set counts or stored memory in said second count
memory means by manipulation of the operator, and display means to display the time
corresponding to counts or stored memory counted and stored by said first and second
count memory means, wherein said time totaling meter and said ignition device of the
internal combustion engine are formed in one body by injection molding or encapsulation
with synthetic resin.
[0022] In addition, the unit may be constructed so as to connect between the ignition device
and said time totaling meter via cables, thereby being able to implement time totaling
treatment based on ignition pulses obtained via said cables.
[0023] Therefore, this time totaling unit for internal combustion engines can directly pick
up ignition pulses from the ignition device into a pulse detection part of the time
totaling meter via the cables, thereby being able to implement measurement of total
time accurately and at high sensitivity based on an adequate level of pulse data.
[0024] Preferably, the upper surface level at one corner of the time totaling meter is lowered
so as to have a pre-determined thickness and the cables are connected to a part of
the ignition device provided on this position.
[0025] Therefore, in this time totaling meter for internal combustion engines, the end of
the cables to be connected to the unit block can be housed inside the time totaling
meter having predetermined thickness. Because the connected part of the end of the
cables does not significantly protrude toward the outside, the space occupied by this
connecting part can be minimized, thereby package size for the time totaling meter
can be compacted. Preferably the unit comprises a case to house the waveform shaping
circuit, count memory means and display means together with the induction coil, wherein
one corner of the case has different surface level from the upper and lower surfaces
of other parts of the case so as to have pre-determined thickness, and several holes
are provided so as to pass through said thinner part from the upper surface to the
lower surface and an antenna lead can be inserted into the holes by bending the end
part thereof.
[0026] Therefore, in this time totaling meter for internal combustion engines, ignition
pulses supplied to an ignition plug can be electromagnetically detected by an induction
coil via the high tension cable and the antenna lead and, by counting detected output
pulses after waveform shaping, total operation time of the internal combustion engine
can be simply and accurately measured.
[0027] Further, the end of said antenna lead can be coupled to said pulse treatment circuit
containing said waveform shaping means inside of said thinner part formed on one corner
of the case, thereby the space occupied by this connection part can be minimized and
therefore the package size for the time totaling meter can be reduced.
[0028] A preferred embodiment of the invention will now be described by way of example only
and with reference to the accompanying drawings in which:
Fig. l is a block diagram showing a time totaling meter for internal combustion engines;
Fig. 2 is an outside view as well as partial inside view showing detail construction
of a time totaling meter for internal combustion engines;
Fig. 3 is a circuit diagram showing the connection relationship between a time totaling
meter and an ignition circuit for internal combustion engines;
Fig. 4 is an outside view showing a chain saw provided with a time totaling meter
for internal combustion engines;
Fig. 5 is a block diagram showing another time totaling meter for internal combustion
engines;
Fig. 6 is a diagram showing connecting structure of a time totaling meter for internal
combustion engines;
Fig. 7 is an outside view showing a time totaling unit for internal combustion engines;
Fig. 8 is an outside view showing a time totaling unit for internal combustion engines;
Fig. 9 is an outside view showing a preferred connecting example of a time totaling
meter;
Fig. 10 is an outside view showing another connecting example of a time totaling meter.
[0029] Fig. 1 is a block diagram showing a whole time totaling meter according to the present
invention. Numeral 1 is a time totaling meter and 2 is a remaining part of an ignition
device connected to this time totaling meter 1. This time totaling meter l includes
a part of the ignition device 3 connected to the remaining part of the ignition device
2.
[0030] In the time totaling meter 1, numeral 4 is pulse induction means comprising a printed
electromagnetic induction coil, for example, and located near to a part of the ignition
device 3 so as to have induced and to detect ignition pulses flowing in this part
of the ignition device 3. Numeral 5 is waveform shaping means to shape the waveform
of output pulses induced.
[0031] The waveform shaping means can be constituted, for example, so as to be able to clip
the ignition pulses obtained by the pulse induction means 4 at a pre-determined level
and then to convert this clipped pulse to a rectangular pulse having a constant time
length by a monostable multivibrator (not shown in the drawings).
[0032] Further, numeral 6 is judging means to distinguish whether said waveform shaped output
could be obtained or not; that is, whether the internal combustion engine is actually
operated (working) or not. Internal combustion engines generate the same shaped pulse
(having the same time length) at constant intervals, while all other pulses have different
peak height and time length even after waveform shaping. Therefore the judging means
can distinguish the pulses actually derived from the operating internal combustion
engine, based on continuity in a unit time of the same shaped pulse output from the
waveform shaping means. 7 is count memory means to count and store surely and accurately
total operation time from the initial operation (from the first operation) of the
internal combustion engine based on normal waveform shaped output selected by this
judging means 6.
[0033] Numeral 8 is display means such as a liquid-crystal display to display counted results
by said count memory means 7. 9 is a pulse treatment circuit comprising said waveform
shaping means 5, judging means 6 and count memory means 7.
[0034] Fig. 2 is an outside view and partial inside view showing detail construction of
said time totaling meter l. In this drawing, a diode 10 comprising a part of the ignition
device 3 is provided on the same printed wiring board 11 together with pulse induction
means 4 and said pulse treatment circuit 9. However, as part of the ignition device
3 it is not always necessary to include the diode 10.
[0035] As shown in Fig. 2, the block of the pulse treatment circuit 9 is provided with said
display means 8. 12 is a case of the time totaling meter 1 to house the part of said
ignition device 3, pulse induction means 4, pulse treatment circuit 9, printed wiring
board 11 and the like. An attachment piece 12b of this case 12 is provided with a
screw hole 14 to insert an attachment screw 13. 12a is a window for the display means
8.
[0036] Numerals 15 and 15 are cables attached to both ends of the diode 10 comprising a
part of said ignition device 3. 16 and 16 are two connectors attached to each cable
15 as connecting terminals. These connectors 16 are provided so as to be attachable
or detachable to two connectors (detailed later) provided in the remaining part 2
in the ignition device.
[0037] Fig. 3 is a circuit showing detail of an ignition device for internal combustion
engines according to the present invention. In this drawing, numeral 21 is a rotor
having a magnet or magnetic poles and rotating synchronously with rotation of the
internal combustion engine. 22 is an induction coil to induce voltage according to
the approach and departure of said magnet by rotation of the rotor 21.
[0038] Further, 23, 24 and 25 are rectifier diodes, and 26 is a resistor to set an electric
potential to trigger a gate of a thyristor (detailed later). 27 is a charge/discharge
capacitor for ignition and 28 is an ignition coil serially connected via the charge/discharge
capacitor 27 and the diode 10 which consists of said part 3 of the ignition device.
This ignition coil 28 consists of a primary coil 28a and a secondary coil 28b and
an ignition plug 29 is connected to the secondary coil 28b.
[0039] Further, 30 is the thyristor which is serially connected to the charge/discharge
capacitor 27 and then to the primary coil 28a of the ignition coil 28 via said resistor
26. The gate of the thyristor 30 is connected to the resistor 26 via the diode 24.
[0040] Numerals 31 and 31 are a pair of cables provided so as to disconnect the circuit
introducing induced voltage to the charge/discharge capacitor 27, and the end of each
cable is provided with a connector 32 as a connecting terminal. And, each of these
connectors 32 is attachable to each connector 16 in said time totaling meter 1 by
one touch.
[0041] In this case, because the diode 10 consisting of a part of the ignition device 3
is directional, each of the connectors 32 must be properly connected to each of the
connectors 16.
[0042] Therefore, it is desirable to form one connector as male and another as female, for
example.
[0043] Furthermore, the remaining part of the ignition device as mentioned above is placed
inside a chain saw 40 together with said internal combustion engine and said time
totaling meter 1 is provided on the chain saw 40 in a freely attachable and detachable
manner as shown in Fig.4, for example.
[0044] This chain saw 40 is provided with a saw chain 42 which can be rotated around a saw
chain guide plate 41 by driving force of said internal combustion engine. On the other
hand, the case 12 of said time totaling meter 1 is attached on the chain saw 40 near
to a handle 43 by attaching screws 13 through screw holes 14 in a manner so as to
be attachable and detachable. 44 is a halt switch which is provided on the chain saw
40 near to the handle 43 and used to bring to halt operation of the ignition circuit
when it is turned on.
[0045] Next, the operation of the time totaling meter and the unit of the same according
to the present invention will be explained. When the internal combustion engine is
fired and the rotor 21 starts rotating, magneto coil 22 generates induced voltage
by 13 magnetic flux of the magnet provided on the rotor 21. Then, said charge/discharge
capacitor 27 for ignition is charged by this voltage supplied via said diode 10 consisting
of a part of the ignition device.
[0046] When the terminal voltage of said resistor 26 reaches the predetermined voltage,
said thyristor 30 is turned on to supply the voltage of the charge/discharge capacitor
27 to the primary coil 28a of the ignition coil 28. Therefore, high voltage is induced
at the secondary coil, and the ignition plug generates spark to fire a mixed gas containing
fuel and air so that the internal combustion engine is continuously operated.
[0047] On the other hand, in the operation of such internal combustion engines, induced
voltage of several hundreds volts is introduced into the charge/discharge capacitor
27 as well as into the part 3 of the circuit; that is, into the time totaling meter
1 having the diode 10 as the part 3 of the ignition device.
[0048] Therefore, ignition pulses are detected by said pulse induction means 4 during their
passage through the diode 10 and then the waveform thereof is shaped by the waveform
shaping means 5. Output of this shaped waveform is input into the judging means 6.
This judging means 6 determines whether output signals from the waveform shaping means
are obtained every unit time or not; that is, whether said pulses are those generated
by operation of the internal combustion engine or not.
[0049] When said ignition pulses are determined that they were generated by operation of
the internal combustion engine, the count memory means 7 count and store total operation
time from the initial operation of the internal combustion engine (from the first
operation of a working machine) based on the result thereof. Then, the total count
obtained is displayed by the display means. Voltage induced by the magneto coil was
used in this embodiment; voltage generated by the secondary coil 28b of the ignition
coil, which has a larger electromagnetic induction effect, may be used.
[0050] On the other hand, to bring the internal combustion engine to a halt, said halt switch
44 is turned on. Thereby the magneto coil 22 is shorted, and charging of the charge/discharge
capacitor 27 as well as supply of ignition pulses to said diode 10 are brought to
a halt.
[0051] Consequently, the operation of the internal combustion engine is brought to a halt
and total operation time of the internal combustion engine from start of operation
is stored in the count memory means 7. The total operation time can be displayed always
or as necessary.
[0052] Meantime, when the total operation time displayed on the display means 8 of the time
totaling meter 1 exceeds 200 hours, the user can perform maintenance to check loosening
of bolts and nuts, decreased power due to time lag of ignition, increase of exhaust
gas and the like. Thus, safety and efficient operation of internal combustion engines
and working machines can be realized afterward.
[0053] Furthermore, said time totaling meter 1 can be removed from working machines such
as the chain saw 40 as shown in Fig. 4 to prevent theft and to avoid mischief by children.
[0054] Thus, at the same time when the time totaling meter is removed from the working machine,
the diode 10 is also removed from the remaining part 2 of the ignition device. Therefore,
charging of the charge/discharge capacitor 27 by induced voltage is inhibited so that
the internal combustion engine cannot be operated. At the same time, the time totaling
meter 1 is also brought to a halt.
[0055] That is, to operate the internal combustion engine (to use the working machine),
the time totaling meter 1 must be attached to the working machine. Specifically, to
operate the internal combustion engine, each of the connectors 16 shown in Fig. 3
is connected to corresponding connector 31 so that operation time afterward is accurately
and automatically added to the actual total operation from the initial operation and
this total value can be displayed on the display means 8.
[0056] In the embodiment described above, the time totaling meter 1 is attached onto an
appropriate position of the main body of the chain saw 40 using attaching screw 13
and the like.
[0057] Alternatively, another structure in which the time totaling meter 1 is attached or
detached by one touch or is screwed in may be used.
[0058] In the time totaling meter of the embodiment aforementioned, the diode 10 is mounted
on the same printed wiring board 11 on which the pulse induction means 4 and the pulse
treatment circuit 9 have been mounted. Thereby, the size and weight of the time totaling
meter itself can be minimized. It is needless to say that separate printed wiring
boards may be used due to reason of design.
[0059] In addition, although the ignition device having the condenser discharge type ignition
circuit was shown in Fig. 3, the same can be applied to other types of ignition device
having a circuit breaker type ignition circuit using a thyristor and power transistor
for switching.
[0060] In this circuit breaker type ignition circuit, the primary short-circuit current
induced in the ignition coil is introduced to the power transistor and then shorted
at the pre-determined timing for example. Thereby, reverse electromotive force is
generated at the primary side of the ignition coil and high voltage at the secondary
side, then it can be output to the ignition plug.
[0061] Fig. 5 shows another arrangement. Different from the time totaling meter for internal
combustion engines aforementioned, in this arrangement, the first count memory means
7A reliably and accurately count and store total operation time from the initial operation.
Further, the second count memory means 7B reliably and accurately count and store
total operation time from the arbitrary time point set by the user by manipulating
re-setting means 50. According to this method, each count and stored value can be
displayed by display means 8 by choice. Other operations and effects are the same
as those obtained by the previous embodiment.
[0062] Fig. 6 shows a connecting diagram of a time totaling meter. This time totaling meter
comprises a magneto coil 22, an ignition coil 28 and an ignition 17 device formed
as a unit block B by aforementioned one-body molding. In this arrangement, a time
totaling meter 1 is also molded in one-body. 61 is a magnet core coiled with the magneto
coil 22 in the unit block 3. 65 is a cable to be connected to a halt switch, and 66
is a high tension cable to be connected to a plug cap.
[0063] That is, the ignition device in the unit block B is connected to a part 3 of the
ignition device in the time totaling meter 1 placed outside the unit block 3 via cables
68 and 68, Further, in this time totaling meter 1, various cumulative pulse treatment
circuits shown in Fig. 1 are provided.
[0064] This arrangement is more effective in case one-body molding of the time totaling
meter 1 and the ignition device is not appropriate; in case operation and reliability
of the time totaling meter are impaired due to effects of heat or noises generated
by said ignition device or in case it is necessary to realize highly sensitive integration
of sufficient level of ignition pulses directly picked up.
[0065] It is not necessary to say that the ignition device may be constructed as a condenser
discharge type having a trigger coil to generate circuit breaker signals or may be
constructed as a circuit breaker type having a power transistor to short the primary
current of an ignition coil by switching a thyristor by output of the trigger coil
or by the primary voltage of the ignition coil.
[0066] That is, a part or whole of the circuit breaker type or condenser discharge type
ignition circuit can be formed in one-body as said unit block 3 and then attached
to said working machine in a manner freely attachable and detachable, combined with
the time totaling meter or independently.
[0067] Fig. 7 shows the structure of another time totaling unit for internal combustion
engines. In this arrangement, the magneto coil 22, the ignition coil 28 and other
parts of the ignition circuit are formed as one-body together with the time totaling
meter 1 by injection molding of thermoplastic resin or built-in molding of thermoplastic
resin so as to form one unit block B.
[0068] Therefore, this unit block 3 is assembled with the magnet core 61 having said magneto
coil 22 as shown in Fig. 7. The rotor 21 provided with multiple magnets 64 along its
peripheral surface at pre-determined intervals is provided near two magnetic poles
62 and 63 of this magnet core 61 so as to freely rotate. This rotor 21 synchronously
rotates by driving force from a driving shaft of the internal combustion engine. Thereby,
voltage of pulse form is induced at said magneto coil 22.
[0069] 65 is the halt switch cable extending from said unit block B and to be connected
to said halt switch 44. 66 is the high tension cable connected to the secondary side
of the ignition coil 28 in said unit block 3 and the plug cap 67 thereof is connected,
to the ignition plug 29 of the internal combustion engine.
[0070] In the time totaling unit constructed in this way, the time totaling meter and the
ignition device of the internal combustion engine can be formed in one-body and these
can be handled as one unit block. Further, a whole ignition control system of the
internal combustion engine can be formed in compact size and its operational reliability
can be improved.
[0071] Fig. 8 shows another time totaling unit. In this structure, the time totaling meter
1 having the first count memory means 7A and the second count memory means 7B shown
in Fig. 5 is formed in one-body as one unit block 3 together with the ignition device.
[0072] Further in Fig. 8, the re-setting means 50 as the re-set switch shown in Fig. 5 is
provided on the time totaling meter 1. This re-setting means 50 is connected to said
second count memory means 73 via the circuit molded in said unit block 3.
[0073] By manipulating this re-setting means 50, the second counter can be reset and restarted.
By manipulating a selector switch of the display means, total operation time stored
in each of the first count memory means 7A and the second count memory means 7B can
be displayed selectively on the display means 8.
[0074] Therefore, the time totaling meter and the ignition device can be molded in one-body
together with the circuit connection with the halt switch cable to bring ignition
operation by this ignition device to a halt so that the ignition system having the
function to halt the ignition control can be realized by one unit block and a whole
system of said ignition circuit can be formed in smaller size and its operational
reliability can be improved.
[0075] Fig. 9 shows a preferred embodiment of the time totaling meter. This time totaling
meter 1A comprises the induction coil 72 provided in the case 71 formed from synthetic
resin in an approximately square shape, wherein in the induction coil 72 is induced
an electromagnetic wave generated from the ignition device.
[0076] Further in this case 71, the waveform shaping circuit (not shown in the drawing)
to shape the output waveform of the induction coil 72, the count memory means to count
pulses after waveform shaping, and the display means to display the result of counting
and the cumulative operation time of the engine are provided.
[0077] Further, 73 is the display window of the display means provided on the case 71, and
74 and 75 are notched parts formed the upper and lower surfaces of the case 71 at
one corner thereof near to said induction coil 72 so as to form a notch 76 having
a predetermined thickness.
[0078] In said notch 76, multiple holes 77 (only two in Fig. 9) are formed in parallel.
An antenna lead 78 is inserted into each hole 77 so as to bend one end thereof. 79
is a splicer such as crocodile clip connected to another end of this antenna lead
78. 80 is the high tension cable (ignition cap cable) connected to the ignition plug
81 via a plug cap 82, and said splicer 79 connects to the core of the tension cable
80 through a hole in the insulation thereof.
[0079] In such time totaling meter, the antenna lead 78 attached with the splicer 79 can
be firmly connected to the notch 76 by inserting the end thereof into two holes 77
provided on the notch 76 so as to have the angle of 45a against the side face of the
case 71.
[0080] By connecting the splicer 79 to the high tension cable 80, an electromagnetic wave
can be obtained by the antenna lead 78 via the high tension cable 80 and then detected
by the induction coil 72. Therefore, after treatment of this detected output by each
circuit in the case 71, the operation time of the engine can be detected at highly
sensitive level and can be displayed on the display window 73.
[0081] Further in this time totaling meter, the end of the antenna lead 78 inserted into
said holes 77 is within the level of the notched parts 74 and 75 and housed within
the level of the total thickness of the case 71. Thus, wiring of the antenna lead
78 is easier.
[0082] Furthermore, because no convex parts are formed to attach the antenna lead 78, space
occupied by the case 71 can be minimized so that not only the size of outer and inner
package boxes can be reduced and the cost for the package can be reduced, also the
time totaling meter can be attached on a narrower space near the internal combustion
engine.
[0083] Further, even if the separately prepared time totaling meter l is connected to the
unit block 3 via the cables 68 as shown in Fig. 6, it is desirable to form the time
totaling meter l as shown in Fig. 10.
[0084] That is, the notched part 83 is formed on one corner of the time totaling meter l
to form a trapezoid notch 81 having a pre-determined thickness.
[0085] Then, said part 3 of the ignition device is provided on said notch 81 and each of
the cables 68 is connected to this part 3. Thereby, the end of each cable 68 on said
notch 81 can be housed within the level of said notched part 82 of the time totaling
meter 1 so that wiring of each cable is easier.
[0086] In addition, because there is no lump formed on the main body of the time totaling
meter 1 for attachment of each cable 68, space occupied by this time totaling meter
1 can be minimized, the size and preparation cost of the package can be reduced, and
the time totaling meter can be easily attached on a narrower space.