JP4565709B2 - Construction machine control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for a construction machine that controls a hydraulic motor when a ground tool is improved by rotating a tool such as a stirring blade by the hydraulic motor.
[0002]
[Prior art]
Conventionally, as disclosed in Japanese Patent Application Laid-Open No. 11-311080, a construction machine that excavates a pile hole by pushing it into the ground while rotating an auger screw is known. In such a construction machine, when the ground to be excavated is soft, the rotational speed is increased to increase the excavation speed, and when the ground is hard, the hydraulic motor torque is increased so that sufficient excavation torque can be secured.
[0003]
[Problems to be solved by the invention]
The output torque T, supply pressure P, and displacement volume V of the hydraulic motor have the following relationship.
T = P × V / (2π)
When a variable displacement volume is used for the hydraulic motor, when the displacement volume V is decreased, the rotational speed of the hydraulic motor increases and the output torque T decreases. Conversely, when the displacement volume V is increased, the output torque T is increased and the rotational speed is decreased. When excavating with an auger screw, it can be handled by increasing the excavating torque during overload.
[0004]
However, when using a stirring blade instead of an auger screw, the number of blade cuttings, which is the number of rotations of the stirring blade in the unit elevation length, is an important construction condition, and the number of rotations can be managed rather than controlling the output torque of the hydraulic motor. Become important.
The subject of this invention is providing the control apparatus of the construction machine which is easy to manage rotation speed.
[0005]
[Means for Solving the Problems]
In order to achieve this problem, the present invention has taken the following measures in order to solve the problem. That is,
In a construction machine that rotates a tool by a hydraulic motor that receives supply of hydraulic oil from a hydraulic pump driven by an internal combustion engine,
The hydraulic motor has a variable displacement according to the pilot pressure introduced,
And a pilot pressure sensor for detecting a pilot pressure to the hydraulic motor;
A rotational speed sensor for detecting the rotational speed of the internal combustion engine;
An electromagnetic control valve for controlling the pilot pressure according to a command signal,
Display control means is provided for calculating and displaying the set rotational speed of the hydraulic motor based on the pilot pressure detected by the pilot pressure sensor and the rotational speed of the internal combustion engine detected by the rotational speed sensor. This is a construction machine control device characterized by the following.
[0006]
Alternatively, setting means for setting a command signal to the electromagnetic control valve may be further provided. In addition, a supply pressure sensor for detecting a supply pressure to the hydraulic motor is provided, and the supply pressure detected by the supply pressure sensor is controlled to a preset boundary pressure of the hydraulic motor by controlling the electromagnetic control valve. Rotation control means may be provided. Alternatively, a supply pressure sensor that detects a supply pressure to the hydraulic motor is provided, and a notification control that issues a warning when the supply pressure detected by the supply pressure sensor exceeds a preset boundary pressure of the hydraulic motor. Means may be provided.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, reference numeral 1 denotes a self-propelled construction machine main body, and a leader 2 is supported by a stay 4 and a catching hawk 6 so as to be tilted up and down. A pair of long guide rails 8 are laid along the longitudinal direction of the front surface of the reader 2.
[0008]
A drive mechanism 12 is slidably attached to the guide rail 8 via a plurality of guide gibs 10. An application tool 14 using a stirring blade is attached to the drive mechanism 12, and as shown in FIG. 2, the application tool 14 is rotationally driven via a speed reducer 18 by a mounted hydraulic motor 16. .
[0009]
A winch 20 is mounted on the construction machine main body 1, and a wire 22 pulled out from the winch 20 is pulled out along the leader 2, and through a sheave 24 that is rotatably supported in the middle of the leader 2. It is hung on a sheave 26 that is rotatably supported on the upper end of the reader 2.
[0010]
Further, after the wire 22 is passed over a sheave 28 provided at the upper end of the reader 2, the drive mechanism 12 is suspended from the wire 22, and one end thereof is fixed to the upper end of the reader 2. . In addition to the winch 20, the pinion engaged with the rack laid on the reader 2 along the guide rail 8 is rotated by a motor provided in the drive mechanism 12, and the drive mechanism 12 is moved up and down. But you can.
[0011]
As shown in FIG. 2, the hydraulic motor 16 is connected to a hydraulic pump 31 via a switching valve 30, and the hydraulic pump 31 pressurizes the hydraulic oil in the hydraulic tank 32, and the hydraulic motor via the switching valve 30. 16 is supplied. The main flow path 34 on the discharge side of the hydraulic pump 31 and the hydraulic tank 32 on the low pressure side are connected via a relief valve 35. The relief valve 35 opens when the supply pressure P3 in the main flow path 34 exceeds a preset set pressure P1, connects the main flow path 34 and the hydraulic tank 32, and releases hydraulic oil to the hydraulic tank 32. It is well known.
[0012]
The hydraulic motor 16 is configured to be able to vary the displacement volume V per revolution, for example, a swash plate type that varies the displacement volume V by tilting the swash plate, a vane type that varies the displacement volume V by moving the cam ring, 2. Description of the Related Art A slanted shaft type hydraulic motor that changes a displacement volume V by tilting a shaft is known.
[0013]
When the hydraulic motor 16 is of the swash plate type, the displacement V is changed by changing the inclination of a swash plate (not shown). The inclination of the swash plate is caused by the balance between the pilot pressure P2 introduced into the working chamber 16a and the spring 16b. Determined. That is, the inclination of the swash plate is proportional to the pilot pressure P2, and therefore the displacement volume V is also proportional to the pilot pressure P2. In this embodiment, the displacement volume V decreases as the pilot pressure P2 increases.
[0014]
The working chamber 16a is connected to a pilot pump 37 via a pilot flow path 36, and an electromagnetic control valve 38 is interposed in the pilot flow path 36. In this embodiment, an electromagnetic proportional pressure reducing valve is used as the electromagnetic control valve 38, and the pilot pressure from the pilot pump 37 is reduced in accordance with an input command signal and led to the working chamber 16a.
[0015]
The electromagnetic control valve 38 is a known valve whose valve opening is determined by balancing the secondary pressure and the electromagnetic force so that the secondary pressure is constant. The pilot flow path 36 on the discharge side of the pilot pump 37 and the hydraulic tank 32 are connected via a relief valve 39.
[0016]
On the other hand, a pilot pressure sensor 40 for detecting the pilot pressure P2 introduced into the working chamber 16a is provided in the pilot flow path 36 on the downstream side of the electromagnetic control valve 38. The main flow path 34 is provided with a supply pressure sensor 42 for detecting a supply pressure P 3 supplied from the hydraulic pump 31 to the main flow path 34.
[0017]
Further, the hydraulic pump 31 is driven by an internal combustion engine 44 mounted on the construction machine main body 1, and in this embodiment, an internal combustion engine rotation speed sensor 45 that detects the rotation speed of the internal combustion engine 44 is provided. A motor rotation speed detection sensor 46 that detects the rotation speed of the hydraulic motor 16 is also provided.
[0018]
The electromagnetic control valve 38, the pilot pressure sensor 40, the supply pressure sensor 42, the internal combustion engine rotational speed sensor 45, and the motor rotational speed detection sensor 46 are each connected to a control device 48. As shown in FIG. 3, the control device 48 includes an electronic control circuit 50, and the electronic control circuit 50 is configured with a well-known CPU 52, ROM 54, and RAM 56 as the center of a logical operation circuit, and inputs and outputs that perform input and output with the outside Circuits 58 are connected to each other via a common bus 60.
[0019]
The CPU 52 inputs signals from the pilot pressure sensor 40, the supply pressure sensor 42, the internal combustion engine rotational speed sensor 45, and the motor rotational speed detection sensor 46 via the input / output circuit 58. On the other hand, the CPU 52 outputs a command signal to the electromagnetic control valve 38 via the input / output circuit 58 based on these signals, data in the ROM 54 and RAM 56 and a previously stored control program, and the displacement volume V of the hydraulic motor 16. Is controlling.
[0020]
The control device 48 includes a setting knob 62 as setting means for setting a command signal to the electromagnetic control valve 38, and a changeover switch 63 for switching between “manual” and “automatic”, and operates the setting knob 62. Thus, the command signal can be varied, and manual operation and automatic operation can be switched.
[0021]
The control device 48 includes a set rotational speed display section 64 and an actual rotational speed display section 66 made of liquid crystal or the like, and a warning lamp 67. The control device 48 calculates the set rotational speed of the tool 14 based on the pilot pressure P2 detected by the pilot pressure sensor 40 and the rotational speed of the internal combustion engine 44, and displays it on the set rotational speed display section 64. Further, the control device 48 calculates the actual rotational speed of the tool 14 from the actual rotational speed of the hydraulic motor 16 detected by the motor rotational speed detection sensor 46 and displays it on the actual rotational speed display unit 66.
[0022]
Since the displacement volume V is determined by the angle of the swash plate of the hydraulic motor 16, the displacement volume V and the pilot pressure P2 are proportional and have the relationship of the following equation. Here, α is a proportionality constant determined by experiments or the like.
V = α × P2
If the amount of hydraulic oil per unit time supplied to the hydraulic motor 16 is known, the set rotational speed of the hydraulic motor 16 set by the pilot pressure P2 is obtained. Since the amount of hydraulic oil is proportional to the rotational speed of the internal combustion engine 44, the set rotational speed of the hydraulic motor 16 set by the pilot pressure P2 can be calculated based on the pilot pressure P2 and the rotational speed of the internal combustion engine 44.
[0023]
Next, the operation of the control device for the construction machine according to the present embodiment will be described together with the control process performed in the electronic control circuit 50.
The operator operates the relief valve 35 to set the maximum supply pressure P1. The maximum supply pressure P1 is a pressure that is set in order to protect these from damage or the like when a pressure higher than this is applied to the hydraulic motor 16, the switching valve 30, the main flow path 34, etc. It is not necessary to set for each construction.
[0024]
When the hydraulic pump 31 is driven, hydraulic oil is supplied from the hydraulic pump 31 to the main flow path 34, and the hydraulic oil is released to the hydraulic tank 32 via the switching valve 30. The hydraulic oil from the pilot pump 37 is supplied to the pilot flow path 36, and the electromagnetic control valve 38 is depressurized according to the command signal set by the setting knob 62 and supplies the depressurized pilot pressure P2 to the working chamber 16a. The swash plate of the hydraulic motor 16 is set at an angle corresponding to the pilot pressure P2.
[0025]
When the operation is started, the operator switches the switching valve 30 to supply high-pressure hydraulic oil discharged from the hydraulic pump 31 to the hydraulic motor 16 via the main flow path 34. Thereby, the tool 14 is rotationally driven. Further, a ground improver such as slurry is discharged from the tool 14 and stirred.
[0026]
Then, the motor control process is executed, and the set rotational speed display process and the actual rotational speed display process are interrupted at regular intervals. When the set rotational speed display process is executed, as shown in FIG. 4, first, the rotational speed of the internal combustion engine 44 is detected by the internal combustion engine rotational speed detection sensor 45 (step 100). Then, the pilot pressure sensor 40 detects the pilot pressure P2 (step 105). Next, the set rotational speed of the tool 14 is calculated from the detected pilot pressure P2, the rotational speed of the internal combustion engine 44, and the reduction ratio of the speed reducer 18 (step 110). Subsequently, the calculated set rotational speed is displayed on the set rotational speed display section 64 (step 115).
[0027]
In the present embodiment, since the rotational speed of the internal combustion engine 44 is detected by the internal combustion engine rotational speed detection sensor 45, the set rotational speed is calculated based on the detected rotational speed .
[0028]
When the actual rotation speed display process is executed, first, as shown in FIG. 6, the rotation speed of the hydraulic motor 16 is detected by the motor rotation speed detection sensor 46 (step 300). Then, the actual rotational speed of the tool 14 is calculated from the detected rotational speed and the reduction ratio of the speed reducer 18 (step 310). Subsequently, the calculated actual rotational speed is displayed on the actual rotational speed display section 66 (step 320).
[0029]
On the other hand, in order to set an efficient rotational speed, a motor control process is executed as shown in FIG. In the motor control process, first, the supply pressure P3 is detected by the supply pressure sensor 42 (step 130). Then, it is determined whether or not it is automatic depending on whether the changeover switch 63 is “automatic” or “manual” (step 140). When “automatic” is selected, it is determined whether or not the supply pressure P3 is smaller than a preset boundary pressure P4 of the hydraulic motor 16 (step 150).
[0030]
When the supply pressure P3 is smaller than the boundary pressure P4, the command signal of the electromagnetic control valve 38 is controlled to increase the pilot pressure P2 (step 160). Thereby, the displacement volume V decreases and the rotation speed of the hydraulic motor 16 increases. Since the torque decreases due to the decrease in the displacement volume V, the supply pressure P3 increases.
[0031]
When it is determined that the supply pressure P3 is equal to the boundary pressure P4 (step 170), the motor control process is repeated. If it is determined that the supply pressure P3 is greater than the boundary pressure P4, the command signal of the electromagnetic control valve 38 is controlled to decrease the pilot pressure P2 (step 180). Thereby, the displacement volume V increases and the rotation speed of the hydraulic motor 16 decreases. Since the torque increases as the displacement volume V increases, the supply pressure P3 decreases. In this way, the supply pressure P3 is controlled to become the boundary pressure P4.
[0032]
The hydraulic pump 31 is driven by the internal combustion engine 44, and the internal combustion engine 44 is controlled with constant horsepower in order to prevent an excessive load from being applied to the hydraulic pump 31. As shown in FIG. 7, the supply pressure and the discharge flow rate of the hydraulic pump 31 are the maximum discharge flow rate up to the boundary pressure P4, and the discharge flow rate decreases when the pressure exceeds the boundary pressure P4. That is, the rotational speed of the hydraulic motor 16 varies.
[0033]
Therefore, during automatic operation, the rotation speed of the hydraulic motor 16 can be adjusted to improve the construction efficiency by controlling the supply pressure P3 to be the boundary pressure P4. In addition, the raising / lowering speed of the drive mechanism 12 is controlled by the winch 20 to be constant.
[0034]
On the other hand, if it is determined by the execution of the process of step 130 that it is manual, it is determined whether or not the supply pressure P3 is smaller than the boundary pressure P4 (step 190). When the supply pressure P3 is smaller than the boundary pressure P4, the motor control process is repeatedly executed. When it is determined that the supply pressure P3 is greater than the boundary pressure P4, the warning lamp 67 is turned on (step 200). The operator watches the lighting of the warning lamp 67, and the operator operates the setting knob 62 to decrease the pilot pressure P2. Thereby, the displacement volume V increases and the rotation speed of the hydraulic motor 16 decreases. Since the torque increases as the displacement volume V increases, the supply pressure P3 decreases.
[0035]
Since the pilot pressure P2 detected by the pilot pressure sensor 40 also changes, the set rotational speed displayed on the set rotational speed display section 64 changes accordingly by operating the setting knob 62. While viewing this display, the operator operates the setting knob 62 to set the rotation speed according to the tool 14.
[0036]
In this embodiment, the execution of the processes in steps 100 to 120 and 300 to 320 serves as a display control means, the execution of the processes in steps 130 to 180 serves as a rotation control means, and the execution of the processes in steps 190 and 200 is performed. Works as a notification control means.
[0037]
The present invention is not limited to such embodiments as described above, and can be implemented in various modes without departing from the gist of the present invention.
[0038]
【The invention's effect】
As described in detail above, the construction machine control device of the present invention displays the set rotational speed of the hydraulic motor based on the pilot pressure and the rotational speed of the internal combustion engine. The number of rotations by the motor can be grasped, and the effect of easy management of the number of rotations is achieved.
[0039]
Moreover, since the set rotational speed is calculated by providing the rotational speed sensor for detecting the rotational speed of the internal combustion engine, the set rotational speed can be calculated with high accuracy. Furthermore, when the supply pressure sensor is provided and the rotation control means for controlling the supply pressure to the boundary pressure is provided, the construction efficiency can be improved. Providing notification control means for issuing a warning can quickly notify that the load on the internal combustion engine or the hydraulic motor is high.
[Brief description of the drawings]
FIG. 1 is a side view of a construction machine using a construction machine control device according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating a configuration of a hydraulic system of a control device for a construction machine according to the present embodiment.
FIG. 3 is a block diagram showing a configuration of an electric system of the present embodiment.
FIG. 4 is a flowchart illustrating an example of a set rotation speed display process performed in the electronic control circuit of the present embodiment.
FIG. 5 is a flowchart showing an example of a motor control process performed in the electronic control circuit of the present embodiment.
FIG. 6 is a flowchart showing an example of an actual rotational speed display process performed in the electronic control circuit of the present embodiment.
FIG. 7 is a graph showing the relationship between the pressure and flow rate of the hydraulic pump according to the present embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Construction machine main body 2 ... Leader 8 ... Guide rail 12 ... Drive mechanism 14 ... Application tool 16 ... Hydraulic motor 18 ... Reduction gear 20 ... Winch 31 ... Hydraulic pump 34 ... Main flow path 35 ... Relief valve 36 ... Pilot flow path 37 ... Pilot pump 38 ... Electromagnetic control valve 40 ... Pilot pressure sensor 42 ... Supply pressure sensor 44 ... Internal combustion engine 45 ... Internal combustion engine speed sensor 46 ... Motor speed detection sensor 48 ... Control device 50 ... Electronic control circuit 64 ... Set speed display Section 66 ... Actual rotation speed display section 67 ... Warning lamp

Claims (4)

In a construction machine that rotates a tool by a hydraulic motor that receives supply of hydraulic oil from a hydraulic pump driven by an internal combustion engine,
The hydraulic motor has a variable displacement according to the pilot pressure introduced,
And a pilot pressure sensor for detecting a pilot pressure to the hydraulic motor;
A rotational speed sensor for detecting the rotational speed of the internal combustion engine;
An electromagnetic control valve for controlling the pilot pressure according to a command signal,
Display control means is provided for calculating and displaying the set rotational speed of the hydraulic motor based on the pilot pressure detected by the pilot pressure sensor and the rotational speed of the internal combustion engine detected by the rotational speed sensor. A control device for construction machines. The construction machine control device according to claim 1 , further comprising setting means for setting a command signal to the electromagnetic control valve. A rotation for providing a supply pressure sensor for detecting a supply pressure to the hydraulic motor and controlling the electromagnetic control valve to control a supply pressure detected by the supply pressure sensor to a preset boundary pressure of the hydraulic motor. 3. The construction machine control apparatus according to claim 1, further comprising a control unit. Provided is a supply pressure sensor for detecting the supply pressure to the hydraulic motor, and a notification control means for issuing a warning when the supply pressure detected by the supply pressure sensor exceeds a preset boundary pressure of the hydraulic motor. The control device for a construction machine according to any one of claims 1 to 3 , further comprising:

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