JPH04231524A - Controller for inclination angle of construction machine - Google Patents

Abstract

PURPOSE:To prevent impact by dropping of construction machine by preventing jack-up of it by a method in which boom is controlled on the basis of loading pressures, detection signal of real inclination angles sensor, and set signal of target inclination angle setter. CONSTITUTION:A sensor 39 for the load pressure of an oil-pressure actuator for boom and a sensor 40 for real inclination angle of construction machine are provided for a controller for the inclination angle of construction machine. A target inclination angle setter 42 for the construction machine, a controller 46 for controlling the flow rate of an actuator 24 for oil pressure, and a controller 44 to output control command signals to the controller 46 on the basis of load pressure signals, real inclination angle signals, and target inclination angle signal are provided for the controller. On the basis of these signal values during excavating, operation, command values for the controller 46 are calculated, and when real inclination angle is great, the boom is driven to reduce jack-up thereby preventing liftup more than necessary.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inclination angle control device for a construction machine used for preventing excessive jacking up of a construction machine for excavation work.

0002

2. Description of the Related Art Construction machines such as hydraulic excavators are used for works such as excavating the ground and removing rocks. This hydraulic excavator will be explained with reference to the drawings. FIG. 5 is an external side view of the hydraulic excavator during excavation work. In general, a hydraulic excavator has an upper revolving structure 12 that has an operator's room on a lower traveling structure 10.
and a boom 1 that rotates in the vertical direction with one end as a fulcrum on the upper revolving body 12.
4, an arm 16, and a bucket 18 are sequentially connected to each other, and the working mechanism section 30 includes a boom hydraulic actuator 24, an arm hydraulic actuator 26, and a bucket hydraulic actuator 28. By appropriately driving the boom hydraulic actuator 24, the arm hydraulic actuator 26, and the bucket hydraulic actuator 28, the ground or the like is excavated with the bucket 18 as shown in the figure.

0003

[Problems to be Solved by the Invention] By the way, during excavation work using the hydraulic excavator, due to various reasons such as the presence of rocks, the entire main body structure is separated from the lower traveling body 10 as shown in FIG.
There are cases where the vehicle is lifted up and tilted (jacked up) using one end as a fulcrum. Generally, the working mechanism section 30
When carrying out excavation work, if the working mechanism section 30 is under the required pressing force against the excavated object, the excavation work can be carried out efficiently, but due to the excavation reaction force from the excavated object, the entire main structure If it is raised above a predetermined level and becomes in the jacked-up state, no further pressing force can be generated and efficiency will not improve. On the other hand, when the excavation point reaches point A shown in Fig. 5 when excavating with the jack up,
Since the excavation reaction force immediately disappears, the entire main body structure, which was in an inclined state, falls to the ground due to gravity, but the impact of this fall is greater as the main body structure rises higher. If such jacking and dropping continues, various problems will occur, such as damage to the tracks and failure of the electrical circuit system due to continuous impact on the electrical circuit system.

The present invention has been made in view of the above-mentioned problems, and aims to prevent the entire main body structure from lifting more than necessary while maintaining the pressing force of the working mechanism part necessary for obtaining high efficiency in excavation work. An object of the present invention is to provide a tilt angle control device for a construction machine that can prevent the impact caused by the entire body structure falling to the ground.

[0005]

Means for Solving the Problems In order to achieve the above object, the present invention provides an inclination angle control device for a construction machine including a working mechanism section having a boom and a boom hydraulic actuator for driving the boom. load pressure detection means for detecting the load pressure of the hydraulic actuator for use;
Actual inclination angle detection means for detecting an actual inclination angle of a main body structure in a construction machine, target inclination angle setting means for determining a target value of the inclination angle of the main body structure, and controlling an outflow flow rate of the boom hydraulic actuator. flow control means;
A control command is given to the flow rate control means based on the load pressure signal from the load pressure detection means, the actual tilt angle signal detected by the actual tilt angle detection means, and the target tilt angle signal set by the target tilt angle setting means. The present invention is characterized by comprising a control means for outputting a signal.

[0006]

[Operation] During excavation work, the load pressure signal detected by the load pressure detection means and the actual inclination angle signal detected by the actual inclination angle detection means are taken in, and these values and the target inclination angle setting means are set. A command value for the flow rate control means is calculated based on the value. As a result, when the actual inclination angle is large, that is, when the jack-up is large, the boom is driven by the pressure oil from the flow rate control means in a direction that reduces the jack-up.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below based on the illustrated embodiments. FIG. 1 is a system diagram of a tilt angle control device for construction machinery according to an embodiment of the present invention. In the figure, 24 is the same boom hydraulic actuator as shown in FIG. 5, 31A is a hydraulic pump, 31B is a pilot circuit hydraulic pump, 32 is a relief valve, 33 is a pilot circuit relief valve, and 34 is a switching valve. Reference numerals 36 and 38 indicate operating valves operated by an operator, which selectively supply pressure oil to the pilot port of the switching valve 34. 39 is a load pressure detection means, which detects the load pressure of the boom hydraulic actuator 24. Reference numeral 40 denotes an actual inclination angle detection means, which is configured using, for example, an inclination measuring device using a weight, and detects the inclination angle of the main body structure from the horizontal line. Reference numeral 42 denotes target inclination angle setting means, which is comprised of an automatic return type switch that can be operated by an operator. Reference numeral 44 denotes a control means, which is composed of a microcomputer, and which receives the load pressure signal from the load pressure detection means 39 and the actual inclination angle detection means 4.
It receives the actual tilt angle signal from 0 and the target tilt angle setting signal from the target tilt angle setting means and calculates a control signal to the pressure control valve, which will be described later. 46 is a pressure control valve;
A pilot pressure is generated according to a control signal from the control means 44. 48 is a shuttle valve, which selects the higher pressure of the outputs of the pressure control valve and the operation valve 38. FIG. 2 is a block diagram showing a schematic configuration of the control means 44 and its relationship with the entire construction machine. In the figure, the same parts as those shown in FIG. 1 are given the same reference numerals. Reference numeral 52 denotes a memory device, into which the actual tilt angle signal outputted from the actual tilt angle detection means 40 and the target tilt angle setting signal outputted from the target tilt angle setting means 42 are input. Reference numeral 54 denotes a regulator, which adjusts the gain according to the load pressure value from the load pressure detection means 39. A compensator 56 corrects the output from the regulator 54 in accordance with the load pressure value from the load pressure detection means 39, and prevents the flow rate characteristics of the flow rate control means from changing.

Next, the operation of this embodiment will be explained with reference to FIGS. 3 and 4. FIG. 3 is a flowchart showing the operation of the control means 44. When performing excavation work, the control means 44 first detects the load pressure signal from the load pressure detection means 39 and the actual inclination angle detection means 4 in step 301.
The actual tilt angle signal from 0 is read in, and the target tilt angle setting command signal from the target tilt angle setting means 42 is also read. Next, in step 302, it is determined whether the target inclination angle setting command signal is on or off. If the target inclination angle setting command signal is on, that is, if the operator closes the switch of the target inclination angle setting means 42, the actual inclination angle signal read this time is stored in the storage device 52 in step 303. Execute processing to use as the target inclination angle signal. In the next step 304, a predetermined correction signal is added to the target inclination angle signal set in step 303, and the deviation between this added value and the actual inclination angle signal read this time is determined. Here, the correction signal is a value determined for the following reason. That is, when performing excavation work with a construction machine, when the excavation force is maximized, the main body structure is tilted by a very small angle (approximately 1° to 5°) compared to a non-excavating state. Therefore, if the jack-up is held down to 0, there is a risk that excavation efficiency will be impaired. Therefore, the above-mentioned disadvantage is avoided by determining the above-mentioned angle as a correction signal and adding this to the target inclination angle signal. In the next step 305, if there is a deviation (that is, in a jack-up state), a control command signal to the pressure control valve 46 is determined in accordance with the deviation and the load pressure signal. Here, for example, if the main body structure is about to be lifted due to a sudden load change, the load pressure of the boom hydraulic actuator 24 will rise rapidly, so this pressure is detected and the control gain of the regulator 54 is increased. The control constant is changed so as to quickly increase the output command value of the control means 44 (use of Fuzzy control is also suitable). In the final step 306, the calculated control command signal is output to the pressure control valve 46. As a result, the pressure control valve 46 outputs pressure oil proportional to the control command signal to the pilot port of the switching valve 34 via the shuttle valve 48, and drives the boom hydraulic actuator to control the boom 1.
4 vertically upward to lower the main body structure and eliminate the jack-up. When the process of step 306 is completed, the process returns to the first step 301 and the above-described process is repeated. On the other hand, in step 302, if the operator turns on the target inclination angle setting means 42 and then releases it to turn it off, the already set target inclination angle is used as is, and the following steps 304, 305, 3
06 processing will be performed.

FIG. 4 is a flowchart showing the operation of another embodiment of the control means 44. In this embodiment, the target inclination angle setting means 42 is not required, and the target inclination angle is automatically set. The control means 44 first reads the load pressure signal from the load pressure detection means 39 and the actual tilt angle signal from the actual tilt angle detection means 40 in step 401 . Next, in step 402, it is determined whether the difference between the actual tilt angle signal read this time and the actual tilt angle signal read a predetermined time ago is less than or equal to a predetermined value. If it is less than the predetermined value, that is, if the hydraulic excavator is not moving, a process is executed in step 403 in which the read value of the actual inclination angle signal a predetermined time ago is used as the target inclination angle signal. Below, steps 404, 405, 406
The processing is the same as that of steps 304, 305, and 306 shown in FIG. However, although there is no addition of correction signals,
Naturally, correction signals can also be added. On the other hand, in step 402, if it is determined that the difference between the actual inclination angle signal read this time and the actual inclination angle signal read a predetermined time ago is greater than or equal to a predetermined value, that is, if it is determined that the hydraulic excavator has moved. In this case, the process of step 403 becomes unnecessary, and the processes of step 404 and subsequent steps are performed. In this case, the target inclination angle signal is the previous step 4.
The target inclination angle signal determined in step 03 is maintained as is.

As described above, in this embodiment, since the boom 14 is controlled by the processing of the control means 44 which receives the load pressure signals from the actual inclination angle detection means 40 and the load pressure detection means 39, the main body structure is This prevents the parts from being jacked up and the impact caused by their falling.

[0011]

According to the present invention, based on the load pressure signal detected by the load pressure detection means, the actual inclination angle signal detected by the actual inclination angle detection means, and the target inclination angle signal set by the target inclination angle setting means. Since the control command signal is output to the flow rate control means, it is possible to prevent the main body structure from being jacked up, and furthermore to prevent the shock caused by the sudden fall of the main body structure to the ground.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a tilt angle control device for construction machinery according to an embodiment of the present invention.

FIG. 2 is a system explanatory diagram showing a schematic configuration of a control means and its relationship with the entire construction machine.

FIG. 3 is a flowchart showing the operation of the control means.

FIG. 4 is a flowchart showing the operation of another embodiment of the control means.

FIG. 5 is an external side view of the hydraulic excavator during excavation work.

[Explanation of symbols]

24 Hydraulic actuator for boom 31A, 31B Hydraulic pump 34 Switching valve 36, 38 Operation valve 39 Load pressure detection means 40 Actual inclination angle detection means 42 Target inclination angle setting means 44 Control means 46 Pressure control valve 48 Shuttle valve 52 Memory device 54 Adjuster 56 Compensator

Claims (5)

[Claims] 1. A tilt angle control device for a construction machine comprising a working mechanism section having a boom and a boom hydraulic actuator for driving the boom, comprising: load pressure detection means for detecting load pressure of the boom hydraulic actuator; Actual inclination angle detection means for detecting an actual inclination angle of a main body structure in the machine; target inclination angle setting means for determining a target value of the inclination angle of the main body structure; and a flow rate for controlling an outflow flow rate of the boom hydraulic actuator. controlling the flow rate based on a control means, a load pressure signal from the load pressure detection means, an actual inclination angle signal detected by the actual inclination angle detection means, and a target inclination angle signal set by the target inclination angle setting means; 1. A tilt angle control device for construction machinery, comprising: control means for outputting a control command signal to the means. 2. The target tilt angle setting means comprises a target tilt angle setting command means operated by an operator, and a storage means for storing an actual tilt angle signal when the target tilt angle setting command means is operated. Claim 1 characterized by
The tilt angle control device for the construction machine described above. 3. The target inclination angle setting means sets the actual inclination angle signal when the amount of change in the actual inclination angle signal within a predetermined time is equal to or less than a predetermined value as the target inclination angle. The inclination angle control device for a construction machine according to claim 1, characterized in that the device is a means for controlling an inclination angle of a construction machine. 4. The control means calculates a control command signal to the flow rate control means so that the actual tilt angle signal matches a value obtained by adding a predetermined correction value to the target tilt angle signal. 4. The inclination angle control device for a construction machine according to claim 1, further comprising a calculation means for calculating. 5. The inclination angle control device for a construction machine according to claim 1, wherein the control means includes an adjuster for adjusting a control gain based on the load pressure signal.