JPH0734948A - Engine speed control device for work machine - Google Patents

Abstract

PURPOSE:To provide an engine speed control device for a work machine, which is capable of obtaining a required engine speed without making fine adjustment of the target engine speed. CONSTITUTION:Storage elements, for example, EEPROM, in which rewrite is electrically possible, and the stored contents can be held even when the power is shut off, are used for the storage part 115 of an engine control unit 11. A computer 13 is connected to the storage part 115 through connectors 14A, 14B, and a target engine speed suited for work environment or the contents of a work is written in the storage part 115 using keyboards of the computer 13. When one of push button switches 101 to 104 is pressed, a control part 111 controls the engine speed of an engine 1 to a corresponding target engine speed written in the storage part 115.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine speed control device for a working machine, which controls a speed of an engine for driving a working mechanism provided in the working machine to a target speed.

[0002]

2. Description of the Related Art A working machine such as a hydraulic excavator and a crane is equipped with an engine for driving a working mechanism. For example, in the case of a hydraulic excavator, a hydraulic pump is rotated by the engine to discharge pressure oil, Oil is used to drive hydraulic actuators such as boom cylinders, arm cylinders, and swing motors to perform arbitrary work. In the work of such a work machine, the engine speed is controlled according to the work content and work environment. The control of the engine speed will be described with reference to the drawings.

FIG. 2 is a block diagram of a conventional engine speed control device for a working machine. In this figure, 1 is an engine,
Reference numeral 2 is a governor for adjusting the fuel injection amount of the engine 1 to determine the engine speed, 3 is a lever for operating the governor 2, 4 is a step motor for driving the lever 3, 5 is a link connected to the step motor 4, 6 Is a push-pull cable that connects the link 5 and the lever 3. Reference numeral 7 is an angle sensor that detects the rotation angle of the step motor 4, and reference numeral 8 is a small link that connects the angle sensor 7 and the lever 5. Reference numeral 9 is a hydraulic pump connected to the engine 1, and supplies pressure oil to a hydraulic actuator (not shown) by the rotation of the engine 1.

A switch box 10 is provided with push button switches 101 to 104. The push button switch 101 (represented by P) is for setting the target revolution speed of the engine 1 to the maximum revolution speed (P mode), and the push button switch 102 (represented by E) is the engine 1
For setting the target rotation speed of the engine 1 to a rotation speed lower than the maximum rotation speed and having a small fuel consumption (E mode), and the push button switch 103 (represented by L) is used to set the target rotation speed of the engine 1 to the low rotation speed. For setting the number (L mode), the push button switch 104 (represented by I) is the engine 1
Is for setting the idling speed (I mode).

Reference numeral 11 denotes an engine control unit constructed by using a microcomputer, and the control unit 1
11, a storage unit 112, a motor driver circuit 113, and an A / D conversion unit 114. Storage unit 112
Is a read-only memory (ROM), and the target rotation speed of the engine 1 designated by the push button switches 101 to 104 is stored in advance. These target rotation speeds are, for example, P mode; 2350 rp.
m, E mode: 1850 rpm, L mode: 1300r
pm, I mode; 850 rpm.

Reference numeral 12 denotes a switch box for finely adjusting the engine speed, which is a push button switch 1 for increasing the engine speed.
21 and push button switch 12 for reducing the number of revolutions
Have two. The switch box 10 and the engine speed fine adjustment switch box 12 are usually installed in a location convenient for the operator of the work machine to operate.

At the time of work, when the operator operates one of the push button switches 101 to 104 according to the work environment (city area, non-residential area, daytime, night, etc.) and the work content, the signal is sent to the control unit 111. Is entered. In response to this, the control unit 111 retrieves the corresponding target rotation speed from the storage unit 112, drives the step motor 4 via the motor driver circuit 113, and operates the governor 2 to reach the instructed target rotation speed. During this operation, the rotation angle of the step motor 4 is detected by the angle sensor 7 via the link 5 and the small link 8, converted into a digital value by the A / D conversion unit 114 and input to the control unit 111. The control unit 111 performs feedback control of the engine speed, and the engine 1 is controlled to the target speed.

If the operator wants to work at a rotational speed slightly higher than the current engine rotational speed, the operator operates the push button switch 121 of the engine rotational speed fine adjustment switch box 12. Since the increase in the engine speed by one pressing operation of the push button switch 121 is set to, for example, 10 rpm, the operator presses the push button switch 121 a number of times to reach a desired rotation speed, and accordingly, Work can be performed at the number of rotations. Conversely, when the operator wants to work at a rotational speed that is slightly lower than the current engine rotational speed, the operator uses the push button switch 122 of the engine rotational speed fine adjustment switch box 12.
Can be adjusted in the same manner as above to adjust the rotational speed.

[0009]

By the way, working machines do not always work on the same site, but rather the site and the working time usually change. Further, the work content is not always the same, and the magnitude of the load often changes. Therefore, the operator needs to operate the push button switch 121 or the push button switch 122 of the engine speed fine adjustment switch box 12 every time the work environment or the work content changes.

For example, when working at night or in an urban area, the E mode is used because the amount of work is large but the noise is large in the P mode. However, even in the urban area, high-rise houses are gathered. At the site, sound reverberates between the buildings, and complaints are flooded from the residents, so the work speed is lower than in E mode. In this case, the rotation speed is too low in the L mode, and the work itself becomes difficult, so that the push button switch 122 of the engine speed fine adjustment switch box 12 is eventually operated.

Further, even when the work in which the P mode is appropriate is performed, if it is considered that the P mode is unfavorable from the viewpoint of fuel consumption, it is required to reduce the engine speed to some extent. In some cases, a push button switch of the engine speed fine adjustment switch box 12 is operated in the same manner. Furthermore, when the work machine is used overseas, there may be work environments and work contents that cannot be imagined in Japan, and in this case also, the operator operates the push button switch of the engine speed fine adjustment switch box 12. Will be required.

However, such operation of the push button switch is very troublesome for the operator. For example, referring to the above example, the standard rotation speed of the E mode is 185.
If you try to reduce 0 rpm to 1700 rpm,
If the operation of the push button switch 122 is 10 rpm, the operation of the push button switch of the engine speed fine adjustment switch box 12 is difficult for the operator because it requires 15 times of operation, which increases the burden on the operator. In reality, it is rarely used, and the actual situation is that the work is performed with an inappropriate number of rotations.

An object of the present invention is to solve the above problems in the prior art and to provide an engine speed control device for a working machine which can obtain a required speed without adjusting the speed.

[0014]

In order to achieve the above object, the present invention provides an engine for driving a working mechanism, and a rotation speed indicating an arbitrary target rotation speed of a plurality of target rotation speeds of the engine. In an engine speed control device for a work machine, which includes an instruction unit and a control unit that controls the engine to a rotation speed corresponding to an instruction from the rotation speed instruction unit, is electrically rewritable and is stored even when the power is cut off. It is characterized in that a storage unit for holding the contents and a connection unit for connecting a computer for writing the target rotation speed corresponding to the instruction of the rotation speed instruction unit to the storage unit are provided.

[0015]

Before the work is started by the work machine, a computer is connected to the connecting portion, and the computer is used to store the rotation speed suitable for the work environment and the work content as the target rotation speed instructed by the rotation speed instruction unit in the storage unit. Store. When performing the work, the operator can perform the work at an appropriate rotation speed by only instructing the target rotation speed with the rotation speed instruction unit, and it is not necessary to finely adjust the rotation speed.

[0016]

The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a block diagram of an engine speed control device for a working machine according to an embodiment of the present invention. In this figure, parts that are the same as or equivalent to those shown in FIG. In this embodiment, the engine fine adjustment switch box 12 shown in FIG. 2 is omitted. 115 is shown in FIG.
Although the storage unit 112 is configured by a ROM, the storage unit 115 of the present embodiment is electrically rewritable and
It is composed of a storage element, for example, an EEPROM, which retains stored contents even when the power is cut off. Reference numeral 13 denotes a portable computer having a keyboard and a display unit, 1
4A is a connector connected to the storage unit 115, and 14B is a connector connected to the computer 13 and electrically coupled to the connector 14A.

Next, the operation of this embodiment will be described. At an appropriate time before the start of work of the work machine, the maintenance personnel of the manufacturing company of the work machine, the computer 1 to which the connector 14B is connected at the request of the owner of the work machine or at the time of maintenance patrol.
3 is carried to the working machine, and the connector 14B is connected to the connector 14A. The connector 14A is installed at an appropriate place on the work machine, for example, near a chair in the driver's cab. Next, the maintenance staff listens to the work environment, the work content, the wishes of the operator, etc. from the owner or operator and sets the target rotation speed corresponding to the push button switches 101 to 104 by operating the keyboard of the computer 13 and the connectors 14B and 14A. Write to the storage unit 115 via
As a result, the target rotation speed most suitable for the work to be performed is stored in the storage unit 115. When the operator operates one of the push button switches 101 to 104, the target rotation speed corresponding to this is retrieved from the storage unit 115 to the control unit 111, and the control unit 111 retrieves the rotation speed of the engine 1. The target rotation speed is controlled.

As described above, in the present embodiment, since the memory element which can be electrically rewritten in the memory section and retains the memory content even when the power is cut off, for example, the EEPROM is used, the memory section is used. The target rotation speed suitable for the work environment and the work content can be set, so that the operator does not need to operate the switch of the engine fine adjustment switch box as in the conventional case, but simply the switch box 1
An appropriate engine speed can be obtained simply by operating the 0 push button switch to instruct the target speed.

In addition, since the storage unit uses a storage element that retains the stored contents even when the power is turned off, no attention is required when replacing or inspecting the battery. Is effective when used for frequent hydraulic excavators.

In the above description of the embodiment, an example in which the maintenance staff of the work machine manufacturing company writes in the storage unit is taken into consideration, but this is due to the danger in case of arbitrary writing, and there is a risk of danger. If there is not, anyone who has knowledge of the writing method using the computer 13, such as the owner of the work machine, the administrator, and the operator, can write. Further, in the description of the above embodiment, an example in which a computer is carried and connected to a connector for writing is described, but the computer may be attached to a work machine.
However, in this case, it is necessary to take measures against dust and vibration. Furthermore, in the description of the above embodiments, an example in which a computer is connected by a connector has been described, but it is also possible to connect the computer to the interface of the control unit and perform writing via the control unit.

[0021]

As described above, according to the present invention, a storage element that can be electrically rewritten in the storage section and retains the stored contents even when the power is cut off is used, and As the target rotation speed to be instructed, an arbitrary rotation speed is written by the computer, so it is possible to set the target rotation speed that is suitable for the work environment and work content, eliminating the need to adjust the rotation speed, and the operator It is possible to reduce the burden of.

[Brief description of drawings]

FIG. 1 is a block diagram of an engine speed control device for a work machine according to an embodiment of the present invention.

FIG. 2 is a block diagram of a conventional engine speed control device for a work machine.

[Explanation of symbols]

 1 Engine 2 Governor 9 Hydraulic Pump 10 Switch Box 11 Engine Control Unit 13 External Computer 14A, 14B Connector 101-104 Push Button Switch 111 Control Unit 115 Storage Unit

Claims (2)

[Claims] 1. An engine for driving a work mechanism, a rotation speed instruction unit for instructing an arbitrary target rotation speed of a plurality of target rotation speeds of the engine, and an engine for responding to an instruction of the rotation speed instruction unit. In an engine rotation speed control device for a work machine, which includes a control unit for controlling the rotation speed, a storage unit that is electrically rewritable and retains stored contents even when the power is cut off, and the rotation speed is stored in the storage unit. An engine speed control device for a working machine, comprising: a connection part for connecting a computer for writing a target speed corresponding to an instruction from the instruction part. 2. The EE according to claim 1, wherein the storage unit is EE.
An engine speed control device for a working machine, which is a PROM.