JP2001214443A - Torque control device for drilling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a torque control device for drilling which is able to prevent damage or the like to drilling tools even though various kind of drilling tools are provided. SOLUTION: An output torque from an actuator which gives rotary drive to a drilling tool for drilling underground is controlled, and the output torque from the actuator is regulated according to set up torque (step 245 to 255). On that occasion, detecting a weight of the drilling tool hung down (step 205), and distinguishing the drilling tool (step 210) according to the weight, to establish the maximum torque TA of the drilling tool distinguished (step 215). And to read in set up torque TS established (step 220). When set up torque TS is bigger than the maximum torque TA, the maximum torque TA is established as set up torque TS (step 230, 235).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an excavating torque control device for controlling an output torque of a driving source that rotationally drives an excavating tool for excavating underground.

[0002]

2. Description of the Related Art Conventionally, the output torque of a driving source that rotationally drives an excavator has been controlled to prevent the excavator from being damaged. For example, as disclosed in Japanese Patent Application Laid-Open No. 10-280409, when a hydraulic motor having a variable displacement according to a pilot pressure introduced as a driving source is used, the pilot pressure is controlled by a control device to output torque. Is controlling.

Further, the control device controls the output torque so as not to exceed a set torque set by a setting switch, regulates an output torque of the hydraulic motor, and prevents breakage of a drilling tool. .

[0004]

However, in such conventional devices, there are various types of digging tools depending on the pile diameter, the construction method, and the like, and a setting switch is set by an operator every time according to the type of digging tools. Since the adjustment has been made, the setting is troublesome, and there is a problem that if the setting is forgotten or the setting is incorrect, the excavator may be damaged.

An object of the present invention is to provide a drilling torque control device capable of preventing breakage of a drilling tool even if there are various types of drilling tools.

[0006]

In order to achieve the above object, the present invention takes the following means to solve the problem. That is, excavation torque control that controls the output torque of a drive source that rotationally drives an excavator that excavates underground and regulates the output torque of the drive source according to a set torque set by a set torque setting unit. In the apparatus, weight detection means for detecting the weight of the suspended drilling tool, and the weight of the drilling tool detected by the weight detection means, the drilling tool is determined, the maximum of the determined drilling tool Maximum torque setting means for setting torque, and limiting means for setting the maximum torque to the set torque when the set torque set in the set torque setting means is larger than the determined maximum torque of the digging tool. The excavating torque setting device is characterized by that.

The weight detecting means may be configured to detect the weight of the drilling tool based on the tension of a wire for suspending the drilling tool. Alternatively, the weight detecting means may be a load cell provided between the wire for suspending the drilling tool and the drilling tool. Furthermore, a switch for instructing the start of the weight measurement of the digging tool may be provided, and the weight detecting means may detect the weight of the digging tool when the switch is operated.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. As shown in FIG. 1, reference numeral 1 denotes a self-propelled excavation machine, on which a leader 2 is provided upright, and a set of rails 4 (only one is shown) is provided along the longitudinal direction of the leader 2. Is laid).

A moving table 6 is slidably engaged with the rail 4, and a rack (not shown) is provided between the pair of rails 4 in parallel with the rail 4 in the reader 2. A pinion gear (not shown) rotated by a motor 8 provided on the moving table 6 is meshed with the rack, and the moving table 6 can be moved up and down along the rail 4 by the rotation of the motor 8. It is configured.

A rotary drive mechanism 10 is mounted on the moving table 6, and as shown in FIG. 2, the rotary drive mechanism 10 includes a hydraulic motor 12, and a small gear 14 attached to the hydraulic motor 12 has a The large gear 16 is meshed. Large gear 16
A large gear 22 that rotates integrally with a transmission shaft 20 that is rotatably supported is meshed with the small gear 18 that rotates integrally with the small gear 18.

The transmission shaft 20 has a sliding hole 24 in its axial direction.
Is formed, and a kelly bar 26 is slidably inserted into the sliding hole 24. For example, when the cross-sectional shape of the kelly bar 26 is square, the sliding hole 24 is also a square hole corresponding thereto, or when the kelly bar 26 is of a spline shape, the sliding hole 24 is corresponding thereto. Hole shape,
The rotation of the transmission shaft 20 is configured to be transmitted to the kelly bar 26.

A wire 28 is fastened to the upper end of the kelly bar 26. The wire 28 is connected to a pair of sheaves 3 provided at the upper end of the leader 2 from the main winch 34 of the excavator 1.
It has been withdrawn through 0,32. A drilling tool 36 is attached to a lower end of the kelever 26. Drilling tool 36
There are various types according to the construction method such as an excavating bucket and an expanded bottom bucket, and various sizes according to the diameter of the hole to be excavated. The excavator 1
The present invention is not limited to the above-described configuration, and can be similarly implemented by an excavating machine 41 having a boom 40 as shown in FIG. The same members as those described above are denoted by the same reference numerals, and detailed description is omitted.

As shown in FIG. 4, the hydraulic motor 12 is connected to a hydraulic pump 52 via a switching valve 50. The hydraulic pump 52 pressurizes hydraulic oil in a hydraulic tank 54, and the switching valve 50 To the hydraulic motor 12 via the
The main flow path 56 on the discharge side of the hydraulic pump 52 and the hydraulic tank 54 as the low pressure side are connected via a relief valve 58.

The relief valve 58 controls the supply pressure P in the main flow path 56.
1 is a well-known device that opens when the pressure exceeds a preset set pressure P3, communicates the main flow path 56 with the hydraulic tank 54, and releases hydraulic oil to the hydraulic tank 54. The set pressure P
3 is preset in accordance with the allowable pressure of hydraulic equipment such as the hydraulic motor 12 and the hydraulic pump 52, for example.

The hydraulic motor 12 has a configuration in which the displacement V per rotation can be varied. For example, a swash plate type in which the displacement V is varied by the inclination of a swash plate, a vane in which the displacement V is varied by moving a cam ring. Hydraulic motors of the oblique axis type and the like that vary the displacement volume V according to the inclination of the oblique axis are known.

When the hydraulic motor 12 is of a swash plate type, the displacement V is changed by changing the inclination of a swash plate (not shown), but the inclination of the swash plate depends on the pilot pressure P2 introduced into the working chamber 12a and the spring 12b. Determined by balance. That is, the inclination of the swash plate is proportional to the pilot pressure P2, and therefore, the displacement V is also proportional to the pilot pressure P2.

The working chamber 12a is connected to a pilot pump 61 via a pilot flow passage 60, and an electromagnetic control valve 62 is interposed in the pilot flow passage 60. In the present embodiment, the electromagnetic control valve 62 uses an electromagnetic proportional pressure reducing valve, and reduces the operating oil pressure from the pilot pump 61 to a pilot pressure in accordance with an input command signal and guides the operating oil pressure to the action chamber 12a. . The electromagnetic control valve 62 has a well-known valve whose opening degree is determined by a balance between the secondary pressure and the electromagnetic force so that the secondary pressure is constant irrespective of the fluctuation of the operating oil pressure discharged from the pilot pump 61. It is. The pilot flow channel 60 on the discharge side of the pilot pump 61 is connected to the hydraulic tank 54 via a relief valve 64.

On the other hand, a pilot pressure sensor 66 for detecting a pilot pressure P2 introduced into the working chamber 12a is provided in the pilot flow passage 60 downstream of the electromagnetic control valve 62. The main flow path 56 has a supply pressure sensor 6 for detecting a supply pressure P1 supplied from the hydraulic pump 52 to the main flow path 56.
8 are provided.

A weight detecting sensor 70 is provided in the middle of the wire 28 as weight detecting means. The weight detection sensor 70 detects the weight of the digging tool 36 in accordance with the tension of the wire 28, and includes three rollers 72 to 74 arranged with the wire 28 interposed therebetween. Detecting the displacement or load of the roller 73,
The weight of the excavator 36 is detected according to the displacement or the load.

The weight detection sensor 70 is not limited to this, and may use a load cell or the like. The weight detection sensor 70 may detect the weight of the excavator 36 by connecting the wire 28 and the kelly bar 26 via the load cell. Good. As shown in FIG.
In the excavating machine 41 provided with the boom 40, the tension of the boom hoisting rope 71a may be measured by the load cell 71b to detect the weight of the excavator 36.

Electromagnetic control valve 62, pilot pressure sensor 6
6. The supply pressure sensor 68 and the weight detection sensor 70 are connected to the control device 100. The control device 100 is configured as a logical operation circuit centered on a well-known CPU 102, ROM 104, RAM 106, and the like.
6. A / D conversion circuit 110 that converts an analog signal from supply pressure sensor 68, weight detection sensor 70, and torque setting device 108 into a digital signal, and D that converts a digital signal into an analog signal and outputs it to electromagnetic control valve 62. / A conversion circuit 1
12, an input circuit 116 for inputting a signal from the weight measurement switch 114, a set torque display section 118 made of a liquid crystal or the like.
And a display circuit 122 for outputting a display signal to the output torque display section 120 are connected to each other via a common bus 124.

The CPU 102 controls the pilot pressure sensor 6
6. The signal from the supply pressure sensor 68, the weight detection sensor 70, the signal from the torque setting device 108 via the A / D conversion circuit 110, and the signal from the weight measurement switch 114 to the input circuit 11
6 while these data and ROM 1
04, based on data in the RAM 106 and a control program stored in advance, the CPU 102
12 to the electromagnetic control valve 62 and the display circuit 122
, And outputs a signal to both display units 118 and 120. The torque setting unit 108 includes a setting knob 108a for setting a set torque of the hydraulic motor 12, and the set torque can be varied by operating the setting knob 108a.

The control device 100 controls the pilot pressure P2,
The output torque Tm is calculated based on the supply pressure P1 detected by the supply pressure sensor 68, and the output torque display section 120
To be displayed. Assuming that the pressure on the suction side is P and the back pressure on the discharge side is almost 0, the torque T of the hydraulic motor 12 has the following formula (1). Here, V is the displacement per one rotation of the hydraulic motor 12 described above.

T = V × P / 2π (1) Since the displacement V is determined by the angle of the swash plate of the hydraulic motor 12, the displacement V is proportional to the pilot pressure P2. There is. Here, α is a proportionality constant obtained by an experiment or the like. Therefore, the torque T of the hydraulic motor 12 and the pilot pressure P2 have a relationship represented by the following equation (3).

V = α × P2 (2) T = α × P2 × P / 2π (3) The hydraulic motor is obtained by the following equation (4) in which the supply pressure P1 is substituted for the pressure P in the above equation (3). The output torque Tm when the operating oil of the supply pressure P1 is supplied to the engine 12 can be calculated.

Tm = α × P 2 × P 1 / 2π (4) Next, the excavation torque control process performed in the control device 100 of the present embodiment will be described with reference to the flowchart of FIG. When the pile hole is constructed by the excavation tool 36, the kelly bar 26 is first suspended from the wire 28, and the excavation tool 36 suitable for the construction method and the pile diameter is attached to the tip of the kelly bar 26. Then, before starting the excavation, it is determined whether or not the weight measurement switch 114 has been operated (step 200). When the operation is being performed, the weight of the digging tool 36 is measured by the weight detection sensor 70 (Step 205). When the weight of the kelly bar 26 is also measured by the weight detection sensor 70 at the same time, the weight of the kelly bar 26 is measured in advance, and the weight of the excavator 36 can be measured by subtracting the weight.

Next, the type of the digging tool 36 is determined based on the measured weight of the digging tool 36. The determination is made in advance by associating the weight, the type, and the maximum torque for each type with the RAM 106.
Etc. are used. The type of the suspended excavator 36 is determined with reference to this map. And
The maximum torque TA is read from the determined type and temporarily stored (step 215).

Subsequently, the setting knob 108a is operated to read the set torque TS set in the torque setting unit 108 (step 220). The read set torque TS is displayed on the set torque display section 118. Next, it is determined whether or not the set torque TS exceeds the maximum torque TA (step 230). If it exceeds, the set torque TS is set to the maximum torque TA (step 235).

On the other hand, when the main winch 34 is driven and the wire 28 is fed out, and the hydraulic oil is supplied to the hydraulic motor 12 and rotated, the kelly bar 26 is rotationally driven. Therefore, excavation is performed by the excavator 36. The pilot pressure P2 detected by the pilot pressure sensor 66 and the supply pressure P detected by the supply pressure sensor 68
1 and the output torque T during excavation based on the above equation (4).
m is calculated (step 240). This output torque Tm
Is displayed on the output torque display unit 120.

Thereafter, the set torque Ts becomes equal to the output torque Tm.
Is determined (step 245). When the set torque TS is smaller than the output torque Tm, the output current to the electromagnetic control valve 62 is reduced (step 25).
0). As a result, the pilot pressure P2 decreases, and the output torque Tm of the hydraulic motor 12 decreases. On the other hand, when the set torque TS is larger than the output torque Tm, the output current to the electromagnetic control valve 62 is increased (step 25).
5). As a result, the pilot pressure P2 increases, and the output torque Tm of the hydraulic motor 12 increases. Step 25
After executing the processes of 0 and 255, the control process is repeatedly executed.

When the weight measuring switch 114 is not operated, the processing of step 220 and subsequent steps is repeatedly executed to read the set torque TS (step 2).
20). The set torque TS is set according to the geology and the like while the digging tool 36 is digging with the same digging tool 36.
08a may be changed. The changed set torque TS is read, and the set torque display section 118 is read.
To be displayed.

Subsequently, it is determined whether or not the changed set torque TS exceeds the maximum torque TA (step 2).
30) If it is exceeded, the set torque TS is set to the maximum torque TA (step 235), and the set torque TS is limited so as not to be set to exceed the maximum torque TA. For example, even if the operator operates the setting knob 108a to set a large set torque TS by mistaking the type of the digging tool 36 used by the operator, the limit is set so as not to exceed the maximum torque TA (step 235). .

On the other hand, when excavation is completed with the currently mounted excavator 36 and the excavator is replaced with another type of excavator, the weight measurement switch 114 is operated after the exchange, and the excavator is operated (step 200). 36 is newly measured (step 205). Then, the type of the digging tool 36 is determined (step 210), and the maximum torque TA corresponding to the new digging tool 36 is read (step 21).
5).

Therefore, the operator does not need to set the maximum torque TA corresponding to the excavating tool 36, and can easily work. In addition, when the setting knob 108a is operated during the operation, the setting torque T exceeds the maximum torque TA of the digging tool 36 in use due to misunderstanding or operation error.
Even if S is set, it is limited to the maximum torque TA or less, so that the excavator 36 is not accidentally damaged.

In this embodiment, steps 205 to 2 are performed.
The execution of the process 15 functions as the maximum torque setting means. Further, the execution of the process of the torque setting unit 108 and step 220 functions as a set torque setting unit. Step 23
The execution of the processing of 0, 235 functions as a limiting unit.

The present invention is not limited to such an embodiment at all, and can be implemented in various modes without departing from the gist of the present invention.

[0037]

As described in detail above, the excavating torque control device according to the present invention does not need to set the maximum torque according to various excavating tools, so that it is easy to perform the operation. Even if the set torque is set to exceed the maximum torque due to a mistake, the torque is limited to the maximum torque or less, so that the excavator is not damaged. Further, by providing the switch for instructing the start of the weight measurement, the weight of the excavator can be accurately measured when the switch is operated.

[Brief description of the drawings]

FIG. 1 is a front view of an excavating machine using an excavating torque control device as one embodiment of the present invention.

FIG. 2 is an enlarged sectional view of the rotation drive mechanism of the embodiment.

FIG. 3 is a front view of an excavating machine as another embodiment.

FIG. 4 is a circuit diagram showing a hydraulic system of the excavating torque control device according to the embodiment.

FIG. 5 is a circuit diagram showing an electric system of the excavation torque control device according to the embodiment.

FIG. 6 is a flowchart illustrating an example of an excavation torque control process performed in the control device of the present embodiment.

[Explanation of symbols]

 1, 41 ... Excavation machine 2 ... Leader 6 ... Moving table 10 ... Rotary drive mechanism 12 ... Hydraulic motor 20 ... Transmission shaft 26 ... Kelly bar 28 ... Wire 34 ... Main winch 36 ... Drilling tool 40 ... Boom 50 ... Switching valve 52 ... Hydraulic pump 60 Pilot flow channel 61 Pilot pump 62 Electromagnetic control valve 64 Relief valve 66 Pilot pressure sensor 68 Supply pressure sensor 70 Weight detection sensor 100 Control device 108 Torque setting device 114 Weight measurement switch 118 ... Set torque display section 120 ... Output torque display section

Continuation of the front page (72) Inventor Masami Kiriyama 1-1, Sanbonmatsucho, Atsuta-ku, Nagoya-shi, Aichi F-term in Japan Vehicle Manufacturing Co., Ltd. (Reference) 2D050 EE10 EE14 FF02 FF05

Claims (4)

[Claims] 1. An excavator for controlling an output torque of a drive source that rotationally drives an excavator for excavating underground, and regulating the output torque of the drive source according to a set torque set by a set torque setting means. A weight detecting means for detecting the weight of the suspended excavating tool; and determining the excavating tool based on the weight of the excavating tool detected by the weight detecting means. Maximum torque setting means for setting the maximum torque of the rig, and limiting means for setting the maximum torque to the set torque when the set torque set in the set torque setting means is greater than the determined maximum torque of the excavator. A torque setting device for excavation, comprising: 2. The excavating torque setting device according to claim 1, wherein the weight detecting means detects the weight of the excavating tool based on a tension of a wire for suspending the excavating tool. 3. The excavating torque setting device according to claim 1, wherein said weight detecting means is a load cell provided between a wire for suspending said excavating tool and said excavating tool. 4. The apparatus according to claim 1, further comprising a switch for instructing a start of measuring the weight of the digging tool, wherein the weight detecting means detects the weight of the digging tool when the switch is operated. An excavating torque setting device according to claim 1.