JPS591079Y2 - Engine speed control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine rotation speed control device for a vehicle equipped with a hydraulic system using a vehicle running engine as a drive source.

In a vehicle that uses a vehicle running engine to drive a hydraulic system, in order to operate the hydraulic system efficiently, the engine speed is increased by manual operation when the hydraulic system is in use. However, when the vehicle starts running after using the hydraulic system, the minimum engine speed must be reduced to the idle speed.

However, there was a risk that the vehicle would often forget to return the set minimum engine speed to the idle speed, resulting in driving with the engine speed set at the increased speed when using the hydraulic system.

This invention solves the above-mentioned drawbacks, and when using the hydraulic system, it is possible to set the engine's minimum rotation speed arbitrarily, and it is possible to turn off the main switch of the hydraulic system (when switching to running mode). ), an engine speed control device is provided in which the set minimum engine speed is dynamically returned to the idle speed.

An embodiment of the present invention will be described below in detail with reference to the drawings.

In the figure, reference numeral 1 denotes a main switch of the hydraulic system, which has a movable contact IC connected to a power source, and has a fixed contact 1a for driving the vehicle and a fixed contact 1b for driving the hydraulic system.

Reference numeral 2 designates an engine speed control switch, which includes a movable contact 2d that connects to the aforementioned contact 1a, a fixed contact 2a that connects to the contact 1b, and an earth contact 2b that connects to the ground.
and a neutral contact 2C, and the movable contact 2d is of a type that returns to the neutral contact 2C when not operated.

The movable contact 2d is connected to the ground via the first relay coil 3, and is connected to the transistor 5 via the resistor 10.
connected to the base of.

The emitter of the transistor 5 is connected to ground, and the collector is connected to the fixed contact 2a via the second relay coil 4.

A resistor 9 is connected between the fixed contact 2a and the movable contact 2d, and an idle switch 7 and a normally closed contact 4a driven by the second loop coil 4 are connected between the fixed contact 2a and the ground contact 2b. , a normally closed contact 3a driven by a first relay coil 3, a normally open contact 3b, and a maximum speed switch 8 are connected in series.

Further, one end of the DC motor 6 is connected to the movable contact 2d, and the other end is connected between the normally closed contact 3a and the normally open contact 3b.

The idle switch 7 becomes non-conductive when the set minimum engine speed is below the idle speed, and the maximum speed switch 8 becomes non-conductive when the engine speed reaches the maximum speed.

The capacitors 11 and 12 prevent the transistor 5 from chattering, and it is sufficient that either one of them is inserted, the resistor 13 is a protection resistor for the transistor 5, and the diode 14 is used to prevent back electromotive force of the relay coil 4. belongs to.

To explain the operation of the engine speed control device having the above configuration, when the hydraulic system is used, the movable contact 1C of the main switch 1 is connected to the fixed contact 1b.

When increasing the set minimum engine speed, the movable contact 2d of the engine speed control switch 2 is connected to the ground contact 2b as shown by the solid line.

Due to the above operation, the first relay coil 3 and the second relay coil 4 are not energized, the normally closed contacts 4a, 3a are closed as shown in the figure, and the normally open contact 3b is open. Therefore, current flows to the DC motor 6 via the contacts 4a and 3a, causing normal rotation.

The output shaft (not shown) of the DC motor 6 is connected to an engine speed change mechanism (accelerator link, carburetor throttle valve, fuel injection device control lever, etc.), and the normal rotation of the DC motor 6 changes the rotation speed. The transmission mechanism is shifted to increase the set minimum engine speed.

However, when the engine reaches its maximum speed, the maximum speed switch 8 opens and the power is cut off.

When the engine reaches the desired rotation speed, the movable contact 2
When d is connected to the neutral contact 2C, the base potential of the transistor 5 rises through the resistors 9 and 10 and conducts, the second relay coil 4 is excited and the normally closed contact 4a is opened.

Since the resistance value of the first relay coil 3 is significantly smaller than that of the resistor 9, it is not excited.

Therefore, the current to the DC motor 6 is cut off and the desired set minimum rotation speed is maintained.

In order to return the set minimum engine speed to the idle speed, by connecting the movable contact 2d to the fixed contact 2a, the relay coil 3 is energized and the transistor 5 is energized.
The base potential increases through the resistor 10 and becomes conductive, so that the relay coil 4 is also energized, the normally closed contacts 4a and 3a are opened, and the normally open contact 3b is closed.

Therefore, the circuit of the power supply, movable contacts 1c and 2d, DC motor 6, normally open contact 3b, idle switch 7, and ground is closed, the DC motor 6 is reversed, and the engine speed changing mechanism is displaced.

When the rotational speed is reduced to the idle speed, the idle switch 7 is opened and the current is cut off.

If you forget to perform this latter operation, in other words, increase the engine speed and connect the movable contact 1C of the main switch 1 to the fixed contact 1a while keeping the movable contact 2d connected to the neutral contact 2C (turn off the hydraulic system and start driving. ), the first relay coil 3 is energized, so the same circuit as described above is closed, the DC motor 7 is rotated in reverse, and the engine is automatically decelerated to the idle speed.

Although NPN type transistors are used in this embodiment, it is of course possible to use PNP type transistors.

In this case, the first relay coil 3 is connected between the movable contact 2d and the fixed contact 2a, the emitter of the transistor 5 is grounded to the contact 2a, and the collector is grounded via the second relay coil 4.

Furthermore, a normally open contact 3b is provided between the DC motor 6 and the contact 2a,
Further, normally closed contacts 3a and 4a are connected between the DC motor 6 and the ground.

As described above, the engine speed control device for a vehicle that uses the vehicle running engine of the present invention to drive a hydraulic system manually controls the engine speed when using the hydraulic system in order to use the hydraulic system efficiently. By turning off the main switch of the hydraulic system, it is possible to increase the engine speed to a desired set minimum speed, and without having to use the engine speed control switch to return the set minimum speed to the idle speed. By switching the switch to driving mode, the engine automatically returns to idle speed, which is extremely effective in improving safety.

Furthermore, in order to enable the hydraulic system to be operated at a location away from the vehicle, the control unit and operation unit (in this example, the main switch, engine speed control switch, and other hydraulic system operation switches) mounted on the vehicle are installed in the vehicle. Consisting of

) are configured to be connected by cable wires, in this embodiment, the cable wires need only be four: a power wire, a ground wire, and two control wires, which has the effect of being highly functional.

[Brief explanation of the drawing]

The figure is a circuit diagram of the engine speed control device of the present invention. 1...Main switch, 1C...Movable contact, 2...Engine speed control switch, 2d...Movable contact, 3... 1st
relay coil, 4... second relay coil,
6...DC motor.

Claims (1)

[Scope of utility model registration request] An engine rotation speed control device that is equipped with a hydraulic system driven by a vehicle running engine and that controls a set minimum rotation speed of the engine by reversibly operating a motor that displaces a rotation speed change mechanism of the engine, and is connected to a power source. A main switch 1 having a movable contact 1C and fixed contacts 1a and 1b, an engine speed control switch 2 having a movable contact 2d connected to the contact 1a, a contact 2a connected to the contact 1b, a neutral contact 2C, and a ground contact 2b. and the first relay coil 3 connected between the movable contact 2d and the ground contact 2b or between the movable contact 2d and the fixed contact 2a, the base is connected to the movable contact 2d via the resistor 10, and the collector is connected to the contact 2a or the ground contact 2b via the second relay coil 4, and the transistor 5 whose emitter is connected to the ground contact 2b or the contact 2a is connected in series between the contact 2a and the ground contact 2b. a series circuit of the normally closed contact 4a of the relay 4, the normally closed contact 3a of the relay 3, and the normally open contact 3b of the relay 3, one end of which is connected to the movable contact 2d, and the other end of the series connected relay 4. Normally closed contact 4
a and normally closed contact 3a of relay 3 and normally open contact 3 of relay 3
An engine rotation speed control device consisting of a DC motor 6 connected between the