U.S. patent number 3,681,658 [Application Number 05/094,768] was granted by the patent office on 1972-08-01 for device for protecting a starting motor of an internal combustion engine.
This patent grant is currently assigned to Hitachi, Ltd.. Invention is credited to Keigo Naoi, Katumi Otuki.
United States Patent |
3,681,658 |
Naoi , et al. |
August 1, 1972 |
DEVICE FOR PROTECTING A STARTING MOTOR OF AN INTERNAL COMBUSTION
ENGINE
Abstract
A device for protecting a starting motor for an internal
combustion engine prevents misoperation of the starting motor. A
normally opened contact which is closed by the output voltage of a
generator is connected in an ignition circuit connected at an end
thereof with a battery, and a normally closed contact which is
opened by the output voltage of the generator is connected in a
starting motor switch circuit, so that the ignition circuit is
closed and the starting motor switch circuit is opened when the
output voltage of the generator is above a definite level.
Inventors: |
Naoi; Keigo (Katsuta,
JA), Otuki; Katumi (Katsuta, JA) |
Assignee: |
Hitachi, Ltd. (Tokyo,
JA)
|
Family
ID: |
14204159 |
Appl.
No.: |
05/094,768 |
Filed: |
December 3, 1970 |
Foreign Application Priority Data
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|
|
|
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Dec 8, 1969 [JA] |
|
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44/97884 |
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Current U.S.
Class: |
361/33; 290/37A;
307/10.6 |
Current CPC
Class: |
F02N
11/105 (20130101); F02B 1/04 (20130101) |
Current International
Class: |
F02N
11/08 (20060101); F02B 1/04 (20060101); F02B
1/00 (20060101); H02h 007/093 () |
Field of
Search: |
;307/1R ;290/37A
;317/13R,31 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Trammell; James D.
Claims
1. A device for protecting a starting means in an internal
combustion engine comprising:
a. a charging circuit including a charging generator consisting of
three dynamo coils in Y-connection and a field coil;
b. a battery being connected to the output terminal of said
charging generator through a rectifier circuit;
c. an ignition switch being connected between said battery and an
ignition load,
d. an indicator lamp being connected between said ignition switch
and a voltage regulator circuit which is connected to said field
coil;
e. a first set of normally open contacts connected in parallel with
said indicator lamp;
f. a starting switch connected between said battery and a second
set of normally closed contacts, which is connected to a voltage
coil of a starting motor circuit and to a voltage detecting coil,
and wherein
g. said voltage detecting coil is connected between said second set
of normally closed contacts and a cathode of a diode, an anode of
said diode being connected to the neutral point of said dynamo
coils of said generator, and wherein said voltage detecting coil is
coupled to said first and second sets of contacts, so as to
respectively close and open
2. A device for protecting a starting means in an internal
combustion engine as claimed in claim 1, wherein an iron core for
said voltage detecting coil, fixed contacts of said first and
second sets and a mounting means are all mounted on a common
supporting bracket, said iron core being placed between said fixed
contacts of the first and second sets and said fixed contacts of
said second set being placed between said iron core and said
mounting means;
an angular part of an L shape armature is fixed on the top of said
mounting means through an elastic plate, a first end of said
armature being extended over said iron core and a second end
thereof being extended between the iron core and the mounting
means;
a movable contact of said first set is placed on the first end of
said armature facing said fixed contact of said first set;
a movable contact of said second set is placed on the second end of
said armature facing to said fixed contact of said second set;
and
said two movable contacts of said first and second set are
insulated from each other.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a device for protecting a starting
motor of an internal combustion engine, and more particularly to a
device for preventing the pinion of the starting motor from being
brought into engagement with the ring gear of the engine when the
key switch is misoperated to drive the starting motor while the
engine is running.
In recent years, the performance of the engine has been much
improved, so that it is sometimes difficult to tell if the engine
is running due to its small mechanical sound made while running.
Accordingly, the driver or operator often drives the starting motor
by mistake without noticing the engine running while the engine is
idling. Such an operation leads the pinion gear generate a metallic
noise. Heretofore, an independent relay device has been provided to
prevent such a reengagement of the pinion. However, such a
construction has been disadvantageous and impractical in that many
parts are needed, the construction becomes complicated, the
construction becomes expensive and so forth.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a device for
preventing the misoperation of the starting motor wherein a
normally opened contact is connected in parallel with the ignition
circuit, a normally closed contact is connected in series with the
starting motor circuit, and the two contacts are made to be induced
by a voltage detecting coil for detecting the output voltage of the
generator whereby the starting motor circuit is cut when the output
voltage of the generator is above a definite level.
Another object of the present invention is to provide a device for
protecting a starting motor which is simple in construction and has
high reliability by making the protection device directly connected
with the conventional voltage regulator for the charging generator
by using the output voltage detecting coil in common.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a view of the electric circuit of an embodiment of the
device for protecting the starting motor for an internal combustion
engine in accordance with the present invention, and
FIG. 2 is an enlarged elevational view of the main portion of the
device of the invention shown in connection with the electric
circuit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Now referring to FIG. 1, the output terminals of the dynamo coils
of a charging generator 1 including three dynamo coils 2 in
Y-connection and a field coil 3 are connected with a battery 5
through a full-wave rectifier 4. An end of the field coil 3 is
grounded and the other end thereof is connected with the battery 5
through a couple of normally closed contacts 7 and 8 of a voltage
regulator 6, a diode 9, an indicator lamp 10 and an ignition switch
11. The reference numeral 12 indicates a voltage detecting coil for
opening the foregoing normally closed contacts 7 and 8 which is
operated by the output voltage of the generator 1. The reference
numeral 13 indicates a resistor connected between the normally
closed contacts 7 and 8. A starting motor 14 includes a normally
opened fixed contact 15 and a normally opened movable contact 16,
both of which are opened and closed by the operation of the voltage
coil 18 acting in response to the opening and closing of the
starting switch 17. The reference numeral 19 denotes a voltage
detecting coil connected with the neutral point of the dynamo coils
2 of the generator 1 through a diode 20, which is connected with
the battery 5 through a normally closed movable contact 21, a
normally closed fixed contact 22 and a starting switch 17. The
normally closed movable contact 21 is opened by the operation of
the voltage detecting coil 19. A normally opened movable contact 23
and a normally opened fixed contact 24 make a normally opened
contact connected in parallel with an ignition switch 11. This
contact 23, 24 is closed by the operation of the voltage detecting
coil 19. The reference numeral 25 indicates a load such as an
ignition load in case of a gasoline engine car which is operated
after the ignition switch 11 is closed.
In the circuit as described above, the voltage detecting coil 19
employed in the device for protecting the starting motor is secured
to a supporting bracket 28 together with a fixed iron piece 27 as
shown in FIG. 2. The voltage detecting coil 19 is wound around an
iron core 26. The foregoing normally opened movable contact 23
which is closed by the operation of the voltage detecting coil 19
is fixed on the end of an elastic iron plate 29 which is fixed at
the other end thereof to the top end 27a of the fixed iron piece
27. The foregoing normally opened fixed contact 24 is disposed on
the top end of a lead member 24a which is riveted on the supporting
bracket 28 at such a position that the fixed contact 24 may be
faced with the said movable contact 23. On the other hand, the
normally closed movable contact 21 riveted through an insulating
plate 31 on an L-shaped metal member 30 which is fixed to said iron
plate 29. The normally closed fixed contact 22 is fixed to an
L-shaped member riveted on the supporting bracket 28 so that the
fixed contact 22 may be faced or in contact with said movable
contact 21.
In operation, when the ignition switch 11 is closed field current
flows into the field coil 3 through the indicator lamp 10, the
diode 9 and the normally closed contacts 7 and 8 of the voltage
regulator 6 to excite the generator 1. Then, in response to the
turning on of the starting switch 17, the starting current flows
into the voltage coil 18 of the starting motor 14 through the
normally closed contacts 21 and 22. When the current flows through
the coil 18, the normally opened contacts 15 and 16 are closed by
the induction force thereof and the starting motor 14 rotates to
start the engine rotation. When the engine starts to run, the
generator is driven by the torque of the engine rotation. In
response to the operation of the generator, the voltage detecting
coil 19 operates to close the normally opened contacts 23 and 24
and open the normally closed contacts 21 and 22 whereby the field
current flows through the contacts 23 and 24 and the starting motor
switch circuit is completely cut. Therefore, even if the starting
switch 17 is turned on by mistake at the time of idling, the
starting motor 14 is not supplied with current, since the normally
closed contacts 21 and 22 are opened by the operation of the
voltage detecting coil 19. It is, accordingly, possible to prevent
the accident such as undesirable engagement of the pinion with the
ring gear.
It will be understood that the diode 20 connected between the
dynamo coil 2 of the generator 1 and the voltage detecting coil 19
is provided for exciting the voltage detecting coil 19 at the time
of starting of the starting motor 14, for preventing the release of
the normally closed contacts 21 and 22 and for exciting the voltage
detecting coil 19 only by the voltage from the neutral point of the
generator 1.
Since the normally closed contacts 21 and 22 for opening and
closing the starting motor circuit uses the voltage detecting coil
19 for the voltage regulator 6 in common, there is no need to
provide a separate protecting relay device. And further, by the
provision of the normally closed contact for controlling the
starting motor circuit on the movable elastic iron plate 29 which
holds the normally opened contact, the whole construction of the
device can be simplified and can be manufactured at low cost.
* * * * *