JPH0238045Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a fuel control device linked to an engine brake, which improves fuel efficiency and eliminates the need to operate a key switch to activate and release the engine brake.

2. Description of the Related Art Conventionally, there is an exhaust brake circuit or a one-key circuit as shown in FIG.
In other words, the exhaust brake circuit includes an exhaust brake control switch 1 that is turned on when the engine speed is above idling and the foot is taken off the accelerator pedal, a clutch switch 2 that is turned on when the foot is taken off the clutch pedal, and an exhaust brake switch. 3. The series connection of the exhaust brake magnetic valve 5 bypassed by the pilot lamp 4 is connected to the power source E.

On the other hand, the one-key circuit is a series connection between the key switch 6 and the relay X for operating the fuel cut motor, and the a contact
a and b contact X-b, which is normally kept closed and closes only when the relay -a and fuel cut motor M
The series connection with the motor contact M-b, which is turned off by the reverse rotation of
Connection point A between and B contact X-b and motor contact M-a
and a connection point B between the motor contact M-b and the motor contact M-b. . And these switches 1,
When 2 and 3 are turned on, the exhaust brake magnetic valve 5 is energized and the exhaust brake is operated.

On the other hand, when the key switch 6 is turned on, the fuel cut motor operating relay The cutting motor M rotates forward, and the fuel cutting cable 8 is pulled through the motor drive shaft 7 to supply fuel to the injection pump 9. When the fuel cut motor M rotates 180° forward, the motor contact M-a
is turned off and the motor contact M that was off
-b is turned on, the fuel cut motor M is stopped, and the fuel supply to the injection pump 9 is maintained.

When the key switch 6 is turned off, the fuel cut motor operation relay The fuel cut motor M rotates in reverse through the motor contact M-b, which pushes the fuel cut cable 8 through the motor drive shaft 7, cutting off the fuel supply to the injection pump 9. Fuel cut motor M
When the motor rotates 180 degrees in the opposite direction, the motor contact M-b turns off and the motor contact M-a, which had been off, turns on, stopping the fuel cut motor M and supplying fuel to the injection pump 9. The cut is held.

In this way, the exhaust brake circuit and the one-key circuit function separately, and since there is no relationship between them, fuel is supplied by the one-key circuit even during the operation of the exhaust brake. In addition, since there is no relationship between the engine brake operation (explained electrically using Fig. 1, the exhaust brake control switch 1 and clutch switch 2 are turned on) and the one-key circuit, the engine brake operation cannot be activated. Inside,
Fuel supply is provided by a one-key circuit.
Therefore, during engine braking including exhaust braking, fuel is wasted unless the key switch 6 of the one-key circuit is turned off. Furthermore, it is troublesome for the driver to turn off the key switch 6 to cut off the fuel supply and then turn it on when the engine brake is released.

It is also effective to cut the fuel when the exhaust brake is activated by connecting the fuel cut motor in parallel to the electromagnetic valve for controlling the exhaust brake valve, as shown in Japanese Patent Application Laid-Open No. 55-37538. It is. However, in this case, fuel is only cut when the exhaust brake is activated, and fuel is not cut under normal engine braking conditions when the exhaust brake is not activated, so fuel efficiency cannot necessarily be improved sufficiently. It was hot.

This idea was made in view of the above circumstances, and by linking the exhaust brake circuit and the one-key circuit in a simple configuration, fuel can be cut not only when the exhaust brake is activated, but also when the engine brake is activated, and the engine The aim is to improve engine fuel efficiency by providing a fuel control device with excellent operability that can automatically stop fuel cut (restart fuel supply) when the brake is released. .

In order to achieve the above objective, this invention has an exhaust brake that is manually opened and closed by a circuit that closes only when the engine speed exceeds a predetermined value, the accelerator pedal is released, and the clutch is engaged. A series circuit between a switch and an exhaust brake magnetic valve is connected in series to form an exhaust brake circuit, while a manually operated key switch and a relay for operating a fuel cut motor are connected in series to form a one-key circuit. In a part of the engine, a relay is connected in parallel to a series circuit between the exhaust brake switch and the exhaust brake magnetic valve. A normally closed b contact which opens when the relay is energized is connected in series to the series circuit of the key switch and the fuel cut motor operating relay.

Therefore, under normal conditions when the engine is operating, the key switch is closed and the fuel cut motor operating relay is energized to maintain the supply of fuel to the engine. However, in this state, when the engine is rotating at a higher speed than a predetermined number of revolutions (for example, idle revolutions), if you release the clutch pedal and then release the accelerator pedal with the clutch still connected, in other words, the engine brake is activated. When activated, the relay connected to the exhaust brake circuit is energized regardless of the state of the exhaust brake switch.
Open the contact point. Then, as the b contact is opened, the power to the fuel cut motor operating relay is cut off, so the fuel cut motor operating relay is deenergized and the supply of fuel to the engine is stopped. Ru. Note that even when the fuel supply is stopped in this manner, since the engine is driven in reverse when the engine brake is activated, stopping of the engine due to fuel cut is avoided.

Also, press the accelerator pedal or
When the clutch is disengaged by depressing the clutch pedal, that is, when the engine brake is released, the relay connected to the exhaust brake circuit is deenergized and its b contact returns to closed. Then, the fuel cut motor activation relay is energized again, so that the fuel supply is restarted.

Note that even when the accelerator pedal is released and the clutch is engaged, the relay connected to the exhaust brake circuit is not energized when the engine speed is lower than a predetermined value. Therefore, even if both the accelerator pedal and the clutch pedal are released when starting the engine, for example, fuel is supplied until the engine speed becomes higher than a predetermined value, thereby ensuring engine startability.

An embodiment of this invention will be described below in detail with reference to FIG. In the embodiment shown in FIG. 2, parts that have substantially the same functions as those in the conventional example shown in FIG. 1 are given the same reference numerals.

In FIG. 2, the exhaust brake circuit includes an exhaust brake control switch 1 that closes when the engine speed is higher than a predetermined value (for example, idling speed) and an accelerator pedal (not shown) is released; A clutch switch 2 that closes when the clutch is connected by releasing the clutch pedal, an exhaust brake switch 3 that is manually operated to open and close, and an exhaust brake magnet that controls the actuator of the exhaust brake valve (not shown). The exhaust brake magnetic valve 5 is connected in series with the exhaust brake magnetic valve 5, and only when the switches 1, 2, and 3 are closed, the exhaust brake magnetic valve 5 is energized and closes the exhaust valve (not shown). The exhaust brake is activated by moving the exhaust brake. Reference numeral 4 denotes a pilot lamp connected in parallel to the exhaust brake magnetic valve 5, which lights up to indicate when the exhaust brake magnetic valve 5 is energized (when the exhaust brake is operating). .

A relay Y is connected in parallel to the series circuit of the exhaust brake switch 3 and the exhaust brake magnetic valve 5, which constitute a part of the exhaust brake circuit thus constructed. Therefore, relay Y is activated when both exhaust brake control switch 1 and clutch switch 2 are closed (when the engine speed is higher than a predetermined value and the accelerator pedal (not shown) is released and the clutch is connected). It is energized to open the b contact x-b.

On the other hand, the one-key circuit that controls switching between fuel supply and fuel cut as the key switch opens and closes (on/off) consists of a key switch 6 and a fuel cut motor operating relay X connected in series to the key switch 6. , a normally closed a contact X-a which is closed when this relay X is energized, and a b contact X-a which is opened when the relay X is energized.
b, a fuel cut motor M, a motor contact M-a that opens when the fuel cut motor M rotates 180 degrees forward, and a motor contact that opens when the fuel cut motor M rotates 180 degrees in the reverse direction. M-b, etc., and a series circuit between the a contact Xa and the b contact X-b of the fuel cut motor operation relay X and the series circuit between the two motor contacts M-a and M-b. Connect the circuits in parallel, and connect the connection point A of both contacts X-a and X-b of relay X and both motor contacts M-
A fuel cut motor M is connected between a and M-b connection point B.

Then, by connecting the b contact Y-b of the relay Y connected to the exhaust brake circuit in series to the series circuit of the key switch 6 and the fuel cut motor operating relay X, the exhaust brake circuit and the one-key circuit are connected. It is linked.

Therefore, when the key switch 6 is turned on when starting the engine, the relay X for fuel cut motor operation is energized through the B contact Y-b, which is turned on, and the relay Since current is supplied to the fuel cut motor M through the contact M-a, the motor M rotates in the forward direction.
A fuel cut cable 8 is pulled through the motor drive shaft 7 to supply fuel to the injection pump 9, and the engine is started. When the fuel cut motor M rotates 180 degrees forward, the motor contact M-a turns off, and the motor contact M-b, which was off, turns on, and the fuel cut motor M stops.
Fuel supply to injection pump 9 is maintained.

Next, when the engine brake is activated (in the case of an exhaust brake, after turning on the exhaust brake switch 3), the exhaust brake control switch 1 and the clutch switch 2 are turned on, and the relay Y is energized. By energizing relay Y, b contact Y-b is turned off, and fuel cut motor operating relay X is deenergized. As a result, the a contact X-a turns off and the b contact X-b turns on, and the b contact X-b
Since current is supplied to the fuel cut motor M through the motor contact M-b, this motor M
rotates in the opposite direction, pushes the fuel cut cable 8 through the motor drive shaft 7, and the injection pump 9
cut off fuel supply to When the fuel cut motor M rotates 180 degrees in the reverse direction, the motor contact M-b turns off, and the motor contact M-a, which was off, turns on, and the fuel cut motor M stops.
A fuel supply cut to the injection pump 9 is retained.

In this way, the fuel supply to the injection pump 9 is automatically cut off in conjunction with the operation of the engine brake, so that fuel is not wasted. Furthermore, the driver is freed from the trouble of turning off the key switch 6 every time the engine brake is activated.

Next, when the engine brake (in the case of exhaust brake, after turning off exhaust brake switch 3) is released, at least one of exhaust brake control switch 1 or clutch switch 2 is turned off, so relay Y is deenergized. Ru. When relay Y is deenergized, b contact Y-b is turned on, and fuel cut motor operating relay X is energized. As a result, fuel is subsequently supplied to the injection pump 9 through a process similar to that at the time of starting the engine described above.

In this way, since the fuel supply to the injection pump 9 is automatically resumed in conjunction with the release of the engine brake, the driver does not have to bother turning on the key switch 6 every time the engine brake is released. be freed from it.

As is clear from the above explanation, according to this invention, when the engine brake is activated, power is cut off to the fuel cut motor activation relay that forms part of the one-key circuit, regardless of the state of the exhaust brake switch. When the engine brake is released, the fuel supply to the engine can be interrupted (cut), and the fuel supply can be automatically restarted when the engine brake is released. Therefore, the fuel efficiency of the engine can be improved without requiring special operations, and the effectiveness of engine braking can also be improved. In addition, fuel is cut only when the engine speed is above a predetermined value, and fuel is not cut when it is less than a predetermined value.
There is no fear that the startability of the engine will be impaired.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the prior art, and FIG. 2 is a diagram showing an embodiment of this invention. 1... Exhaust brake control switch, 2... Clutch switch, 3... Exhaust brake switch, 5... Exhaust brake magnetic valve, 6... Key switch, X... Fuel cut motor operation relay, M... Fuel Cutting motor, 9... Injection pump, Y... Relay.

Claims (1)

[Scope of utility model registration request] A series circuit between the exhaust brake switch and the exhaust brake magnetic valve, which is manually opened and closed, is connected to the circuit that closes when the engine speed is above a predetermined value, the accelerator pedal is released, and the clutch is engaged. While connecting in series to form an exhaust brake circuit,
In an engine in which a manually operated key switch and a fuel cut motor operating relay are connected in series to form a part of a one-key circuit, a relay is connected to the series circuit between the exhaust brake switch and the exhaust brake magnetic valve. An engine brake characterized in that a normally closed b contact which is connected in parallel and opens when the relay is energized is connected in series to the series circuit of the key switch and the fuel cut motor operating relay. Fuel control device linked to.