JPS591080Y2 - 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 whose drive source is for vehicle running.

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 is a risk that the vehicle often forgets to return the set minimum engine speed to the idle speed, resulting in the vehicle driving with the engine speed set at the increased speed when the hydraulic system is used.

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 when the main switch of the hydraulic system is turned off (switched to running). provides an engine speed control device in which the set minimum engine speed automatically returns to the idle speed.

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

In the figure, the movable contact 2 of the main switch 2 of the hydraulic system
C is connected to the power source 1 and is a fixed contact 2a.

2b is each engine speed control switch 3
The fixed contact 3a and the movable contact 3d are connected to the fixed contact 3a and the movable contact 3d.

The fixed contact 3a is connected to a relay 4 and a first nomit switch 5.
The other fixed contact 3b of the engine speed control switch 3 is grounded via the motor 7, the normally closed contact 4b of the relay 4, and the second limit switch 6 in series.

Further, a normally open contact 4a of the relay 4 is inserted between the fixed contact 3a and the relay 4 and between the motor 7 and the normally closed contact 4b, and a normally open contact 4a of the relay 4 is inserted in parallel with the motor 7 and the normally closed contact 4b. Open contact 4C is inserted.

The first limit switch 5 is turned on when the engine reaches the idle speed or higher, and the second limit switch 6 is turned off when the engine reaches the maximum speed.

The motor 7 is a DC motor, and its output shaft is connected to an engine speed change mechanism (accelerator link, carburetor throttle valve, fuel injection device control lever, etc.).

The engine speed control switch 3 has a neutral contact 3C in addition to the above-mentioned fixed contacts 3a and 3b.

To explain the operation of the engine speed control device having the above configuration, when using the hydraulic system, the movable contact 2C of the main switch 2 is connected to the fixed contact 2b.

When increasing the engine speed, the movable contact 3d of the engine speed control switch 3 is connected to the fixed contact 3b.

By the above operations, the power supply 1, the movable contact 2c of the main switch 2, the fixed contact 2b, the movable contact 3d of the engine speed control switch 3, the fixed contact 3b, and the motor full-4
The circuit of the normally closed contact 4b and the second limit switch 6 is closed, and the motor 7 rotates in a predetermined direction to displace the engine speed change mechanism and increase the set minimum engine speed.

When the desired engine speed is reached, move the movable contact 3d of the engine speed control switch 3 to the neutral contact 3C.
to maintain the above rotation speed.

To return the engine to idle speed, move the movable contact 3d of the engine speed control switch 3 to the fixed contact 3.
By connecting to a, the relay 4 is energized (the first limit switch 5 is conductive when the engine is at or above the idle speed), the normally open contacts 4a and 4C are closed, and the normally closed contact is 4b is opened, the power supply 1, the movable contact 2C1 of the main switch 2, the fixed contact 2b, the movable contact 3d of the engine speed control switch 3, and the fixed contact 3a
Normally open contact 4a of relay 4, motor 7, normally open contact 4C second
The circuit of limit switch 6 is closed, motor 7 rotates in the opposite direction to that described above, and the engine speed is reduced.

When the engine reaches idle speed, the first limit switch 5 becomes non-conductive, the relay 4 is demagnetized, and the above-mentioned circuit is automatically opened.

Even if you forget to perform this latter operation, that is, increase the engine speed and connect the movable contact 2C of the main switch 2 to the fixed contact 2a while the movable contact 3d of the engine speed control switch 3 is connected to the neutral contact 3C. Since the fixed contact 2a is connected to the fixed contact 3a of the engine speed control switch 3, the same circuit as described above is obtained after the fixed contact 3a, and the engine automatically returns to the idle speed.

Furthermore, when the engine speed is increased in the second steering wheel 6 in this embodiment, current flows to the motor 7 even after the displacement of the engine speed change mechanism is forcibly stopped at the maximum speed position. This is to prevent this from happening.

As described above, the engine rotation speed control device of the present invention is designed to control the engine rotation speed by manual operation when using the hydraulic system in order to use the hydraulic system efficiently in a vehicle that uses the vehicle engine to drive the hydraulic system. The main switch of the hydraulic system can be cut off without using the engine speed control switch to return the set minimum speed to the idle speed. By switching the engine speed, the engine automatically reaches the idle speed, which is a useful idea for improving safety.

[Brief explanation of the drawing]

The figure is a circuit diagram of the engine speed control device of the present invention. 1... Power source, 2... Main switch, 2C... Movable contact, 3... Engine speed control switch, 4... Relay 5... First limit switch,
7...Motor.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. Engine rotation that is equipped with a hydraulic system driven by a vehicle running engine and that controls the set minimum rotation speed of the engine by reversibly operating a motor that displaces the rotation speed variable transmission mechanism of the engine. The main switch 2 has a movable contact 2C connected to one end of the power supply 1, a fixed contact 2a for traveling and a fixed contact 2b for the hydraulic system, a movable contact 3d, a fixed contact 3a for reducing the rotation speed, and a fixed contact 3a for increasing the rotation speed. Fixed contact 3b
The contact 3d is connected to the contact 2b, and the contact 3a is connected to the contact 2b.
an engine speed control switch 3 connected to the contact 2a, a relay 4 connected between the contact 3a and the other end of the power source 1, and a first limit that becomes non-conductive at the idle speed of the engine. A series circuit of switch 5,
a series circuit of the motor 7 and the normally closed contact 4b of the relay 4 connected between the contact 3b and the other end of the power source 1;
A connection point between the contact 3a and the relay 4 and the motor 1
and a normally open contact 4a of the relay 4 connected between the connection point of the motor 7 and the contact 4b, and a normally open contact 4C of the relay 4 connected in parallel to the series circuit of the motor 7 and the contact 4b.
An engine speed control device consisting of. 2. Utility model registration according to claim 1, in which a second limit switch 6 is connected between the normally closed contact 4b of the relay 4 and the other end of the power source 1, which becomes non-conductive at the maximum rotational speed of the engine. Engine speed control device.