JPS60206944A - Automatic decelerator - Google Patents

Abstract

PURPOSE:To save the fuel consumption and to reduce noise of construction machine by providing an automatic decelerator for dropping the engine rotation below the setting level automatically upon detection that all operating levers are in non-operating condition. CONSTITUTION:Under operation of construction machine, a controller 10 will detect the operating position of fuel control lever 1 from the output of a potentiometer 11 and to decide whether said position will correspond with higher rotation than that under automatic deceleration. Upon decision of YES, it is decided whether the series circuit of an automatic deceleration release switch 12, travel limit switches 12', 13 and a pressure switch 14 is closed or not. If it is closed, the construction machine is not operating to turn on a solenoid valve 9 upon duration of this state for predetermined time (4sec, for example). Consequently, a decelerator cylinder 7 is functioned to lower the rotation of engine 5 through a governer 6.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an auto-deceleration device for controlling the engine rotation of a construction machine. However, there are downtimes between these tasks, such as waiting for a dump.

During this downtime, it is desirable to run the engine at idle to prevent noise generation and improve fuel efficiency, but it is cumbersome for the operator to operate the fuel control lever to the idle position every time work is stopped. Therefore, even during the above-mentioned downtime, the air pump must be running at full speed.d! many.

In view of this situation, it is an object of the present invention to provide an auto-deceleration device that can automatically reduce the engine speed to a set speed when work is stopped.

Therefore, in the present invention, there is provided a means for detecting that all the work operation levers are in the non-operating state, and a means for reducing the engine speed when the above-mentioned non-operating state is detected by the means. ing.

Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 shows the system configuration of an auto-deceleration device according to the present invention, and is shown with the fuel control lever 1 in the stop position (I).

The amount of operation of the ffi charge control lever 1 is the rod i'
, 2, is transmitted to the governor 6 of the engine 5 via a rod link mechanism consisting of a cylinder 3 with a loop spring 3a and a rod 4. The rotational speed of the engine 5 is controlled in accordance with the position of the governor 6 and the amount of fuel injected.

The stop position fFffi (1) of the lever 1 is the governor 6.
corresponds to the position where no fuel is supplied. 1, lever 1 positions fit (It) and (g) indicated by broken lines correspond to the idling position and the high idling position, respectively.

A central portion of the rod 4 is continuous with a piston rod 7a of the deceleration cylinder 7 via an elongated yoke 8. This deceleration cylinder 7 is controlled by a solenoid valve 9 that is on/off controlled by a control device 0, which will be described later, and when activated, the rotational position of the governor 6 is set to the auto deceleration position (a position with a lower rotational speed than the high idle position). It works to return it. Note that details will be described later.

An I tension meter 11 is attached to the rotating portion of the fuel control lever 1, and a signal corresponding to the lever position is applied to the controller 10. The controller 10 also includes an auto deceleration release switch 1.
An electric circuit is provided in which two travel limit switches 12', 13 and a pressure switch 14 are connected in series.

The auto-deceleration release switch 12 is a switch for selecting whether or not to activate the auto-deceleration function, and is turned off when the auto-deceleration function is not activated. The travel limit switches 12' and 13 are turned on and off in conjunction with the travel operation levers 15 and 16, respectively, and are turned off when the levers are operated.

The pressure switch 14 detects the oil pressure of the pressure oil from the shuttle valve 17, and is turned off at a constant pressure of 9 when the working machine is working. That is, work equipment operating levers 18.19, 20.2 that control the packet, pump, arm, rotation, etc.
1, the PPC valves (proportional armature control valves) 22 and 23 (proportional control valves) output pressure oil to the shuttle valve 17 in accordance with the amount of operation thereof. The pressure switch 14 is activated when pressure oil is output from the shuttle valve 17, that is, when one of the operating levers is
When operated, the pressure oil turns it off.

Note that pressure oil is supplied to the electromagnetic valve 9 and the PPC valves 22, 23 from a control pump 7D24 driven by the engine 5.

Now, the engines of construction machinery are normally operated at high idle speed, which maximizes the engine's capacity. That is,
The fuel control lever 1 is installed at a high idle position (as shown in FIG. 2).

At this time, the movement of the rod 4 is not mechanically interfered with by the deceleration cylinder 7 due to the elongated hole of the elongated hole yoke 78.

Here, if the operating lever is not operated for a certain period of time, for example due to waiting for dumping, the controller 10 determines this and turns on the solenoid valve 9 to supply pressure oil to the deceleration cylinder 7 via the solenoid valve 9. do. Accordingly, the deceleration cylinder 7 extends the piston rod 7a as shown in FIG. Push back in the direction.

As a result, the governor 6 is rotated to the auto-deceleration position, and the rotation of the engine 5 is automatically reduced to a rotation lower than the high idle rotation. Further, the movement of the rod 4 at this time is absorbed by the cylinder 3 having a loose spring 3a, so that the rods I', 2 and the fuel control lever 1t do not operate.

Next, details of the processing of the controller 10 will be explained with reference to the flowchart shown in FIG.

Please change the operating position of the fuel control lever l to J? The signal from the tension meter 11 is read and it is determined whether the position corresponds to the rotation speed or higher at the time of auto-deceleration. This is because if the position of the lever 1 is below the rotational speed at the time of auto-deceleration, it is completely meaningless to operate the auto-deceleration function.

When the lever 1 is in a position where the rotation speed exceeds the number of rotations during auto-deceleration (for example, a high idle position), the above-mentioned auto-deceleration release switch 11, travel limit switches 12, 13, and pressure switch 14 are connected in series. It is determined whether the detected circuit (detection circuit) is a closed circuit or not.

If the circuit is closed, the construction machine is not working, so the controller 10 operates a built-in timer. This timer measures the time of the closed circuit state, and outputs a signal that turns on the solenoid valve 9 when the closed circuit state continues for a certain period of time (for example, 4 seconds).

As described above, when the solenoid valve 9 is turned on, the deceleration cylinder 7 is operated and the engine speed of 50 rotations is reduced to a rotation corresponding to the auto-deceleration position of the governor 6.

The timer is also reset when the detection circuit becomes open circuit. Therefore, when the auto deceleration function is working and the engine speed is decreasing, for example, if the work equipment control lever is operated, the detection circuit becomes an open circuit, and the solenoid valve 9
is turned off, the spring 7b built in the decel cylinder 7 returns the piston rod 7a, the pressure oil in the cylinder 7 flows to the drain 25, and at the same time the loose spring 3a in the cylinder 3, which had been compressed, expands. , the governor 6 (rod 4) returns to the idle position shown in FIG.

In this embodiment, the non-working state of the work equipment operating lever is detected by the pressure switch 14, but each work equipment operating lever is provided with a limit switch that detects all neutral positions of the lever, and all limit switches are activated simultaneously. The non-working state may be set when the neutral position is detected.

As explained above, according to the present invention, the rotation speed of the engine of the construction machine can be automatically lowered when the construction machine is not working, so it is possible to save fuel consumption and reduce the number of hills. Moreover, the labor of the operator can be reduced. In addition, the present invention has two systems: a fuel control lever control system and a controller automatic control system, and in particular, the fuel control lever can control the governor manually and efficiently. Since it can be controlled, even if a failure occurs in the electrical system, the engine rotation speed can be controlled, and the two systems are configured so that mutual interference does not occur.

[Brief explanation of drawings]

FIG. 1 is a system configuration diagram showing an embodiment of the auto deceleration device according to the present invention, FIGS. 2 and 3 are diagrams showing the auto deceleration device before and after operation, respectively, and FIG. 4 is the same as the one shown in FIG. 2 is a flowchart showing the processing content of the controller. 1...Fuel control lever, 3...Cylinder,
3a... Loose spring, 4... Rod, 5...
・Engine, 6... Governor, 7... Decel cylinder, 8... Long hole yoke, 9... Solenoid valve, 10... Controller, 11... Potentiometer, 12...
Auto deceleration release switch, 12', 13... Traveling limit switch, 14... Pressure switch, 15.1
6... Travel operation lever, 17... Shuttle valve, 1
8-21... Work equipment operating lever, 22.23...p
pc valve. □ Figure 1 Figure 2 CI Figure 3 Figure 4

Claims (5)

[Claims] (1) A means for mechanically transmitting the operating amount of the fuel control lever to the governor of the engine via a loose spring, and a means connected between the loose spring of the transmitting means and the governor, and when activated, the governor position is set to the auto-deceleration position. the hydraulic actuator, a means for detecting that the operating lever of the construction machine is in a non-operating state, and a controller that operates the hydraulic actuator when the non-operating state of the operating lever is continuously detected for a predetermined period or more. Auto deceleration device. (2) The auto deceleration device according to claim 1, wherein the operating lever includes a work equipment operating lever and a travel operating lever. (3) The work equipment operating lever is for driving a proportional control valve that controls the hydraulic pressure supplied to the hydraulic actuator of the work equipment, and the detection of the non-operating state of the work equipment operating lever is based on the discharge from the proportional control valve. The auto-deceleration device according to claim 1, wherein the auto-deceleration device is operated by a pressure switch that detects the pressure of the pressurized oil. (4) The hydraulic actuator is connected to the transmission means through an elongated hole yoke that absorbs the amount of movement of the connection part with the transmission means due to the operation amount of the fuel controller when the hydraulic actuator is not in operation. The auto-deceleration device according to claim 1, wherein the return force is transmitted to the transmission means through one end of the elongated hole of the elongated hole yoke during operation. (5) The hydraulic actuator comprises a deceleration cylinder whose piston rod is connected to the elongated hole yoke, and a solenoid valve that receives a signal from the controller and supplies pressure oil to the deceleration cylinder. The autodeceleration device described in section 1).