JPS59150838A - Control mechanism of excavator - Google Patents

Abstract

PURPOSE:To exactly synchronize the rotations of a slewing base and a working base by a method in which the rotation angles of the slewing base and the working base are detected, and on the results of calculation and processing of the detected values by a signal processor, the action of the oil-pressure motor of the slewing base is controlled. CONSTITUTION:To rotate a slewing base 14 and a working base 20, switches 62 and 63 are closed, a relay 67 is closed by a drive circuit 66, and current is supplied to a solenoid 68. A solenoid valve is actuated by the solenoid 68, oil pressure is supplied to an oil-pressure motor 41, and the working base 20 is operated in relation to the slewing base 14. On the other hand, a relay 76 is closed by a drive circuit 75, a solenoid 77 is operated, and the slewing base 14 is turned in relation to the vehicular body 10. In this case, the rotation angles of the slewing base 14 and the working base 20 are detected by magnetic pickups 53 and 54, the detected values are calculated and processed in a comparision and coincidence circuit 73, and on the basis of the processed results, the solenoid 77 and the oil-pressure motor 18 are stepwisely controlled in order to minimize the error of the synchronous rotations of the slewing base 14 and the working base 20.

Description

Detailed Description of the Invention The present invention is capable of: ``During the excavation of a road, etc., the turning range is narrowed during the work, which obstructs other work, and the progress of vehicles is obstructed by occupying the road. The present invention relates to an excavator that can prevent such problems, and particularly to a control mechanism for an excavator that can smoothly operate the excavator.

In conventional excavators, an arm protrudes from the vehicle body, and a packet for excavating dirt is attached to the tip of this arm. However, with this configuration, when transferring the excavated soil to the rear of the vehicle body, the arm and packet are attached to the side of the vehicle body. There was a risk of the device jumping out and hitting people standing nearby, and it also had the disadvantage of widening the work area. For this reason, a swivel platform and a workbench were installed on the vehicle body with their rotational axes eccentric, and the packet was configured to pass above the vehicle body so that the arm and packet would not protrude too far from the side of the vehicle body. An excavator is proposed. However, with this new excavator, both the swivel platform and the work platform must be rotated in a predetermined direction, and if these rotations are not synchronized, the packet will not pass over the vehicle body reliably, and the swivel mechanism is complicated. It had no choice but to become. For this reason, in the past, the swivel platform and the work platform were linked and synchronized by a single mechanical drive mechanism using gears, etc., but this concentrated stress on one point, which could easily cause a breakdown, and The power loss due to tongue scraping was large and the efficiency was poor.

In view of the above-mentioned drawbacks, the present invention has been developed by shaving the swivel table and the work table, rotating them with their own TP power, detecting the rotation angle of both with a detection device, and comparing and determining the detection results between the two. The present invention provides a control mechanism for an excavator that can control the driving force and link and synchronize the rotations of the rotating platform and the work platform.

An embodiment of the present invention will be described below.

FIG. 1 is a perspective view of this embodiment, FIG. 2 is a side view, FIG. 3 is a front view, and FIG. 4 is a plan view. This excavator is self-propelled, and the bottom surface of the vehicle body 10 is flat.
! A wheel 11 is pivotally supported at the I corner, and a caterpillar (endless track) 12 is wound between each pair of wheels 11 on both sides of the vehicle body 10.

An annular support plate 13 is fixed to the center of the upper surface of the vehicle body 10, and a deformed hexagonal swivel table 14 is pivotably supported on the support plate 13 so as to be horizontally rotatable. The swivel base 14 has a planar shape with each vertex of an equilateral triangle cut out, and an engine 15. fuel tank 1
62 Hydraulic oil tank 17 is mounted and fixed, swivel base 1
A hydraulic motor 18 is fixed at a position slightly closer to the fuel tank 16 than the center of the upper surface of the fuel tank 4, with its first drive shaft facing downward. The front of this swivel table 14 (Fig. 2).

A ring-shaped holding plate 19 is placed and fixed on the upper part of the support plate (right side in Fig. 4), and the central axis of the aforementioned supporting plate 13 and the central axis of this holding plate 19 are offset by one horizontal direction. and position them so that they are parallel to each other. A circular workbench 2o is rotatably supported on the holding plate 19, and a support 21 is fixed vertically to the workbench 20JcK. Connectors 22 are fixedly spaced above and below. A proximal body 2 is provided between the connectors 22.
6 are connected to each other, a dogleg-shaped boom 27 is swingably connected to the proximal body 26, and an arm 28 is swingably connected to the tip of the boom 27. A packet 29 is swingably connected to the tip of the arm 28. Hydraulic cylinders 30 and 31 are provided between the base body 26 and the center of the boom 27, between the center of the boom 27 and the end of the arm 28, and between the arm 28 and the packet 29, respectively.
．． 32 is interposed. This pool 27. Arm 28
An excavation mechanism 47 is constituted by the packet 29 and the like. Also,
A passenger platform 23 made of a steel plate bent into an L shape is fixed to one side of the base body 26, and a seat 2 is mounted on the passenger platform 23.
4 and the control box 25 are firmly attached.

Next, FIG. 5 shows the turning mechanism in this embodiment in detail, and corresponds to the sectional view taken along the line A--A in FIG. 4. On the support plate 13 mentioned above, there is a circular driving gear 3 having an outer diameter almost the same as that of the support plate 13 and having a tooth profile cut and formed on the inner circumference.
A ring-shaped slider 35 is rotatably fitted to the outer periphery of the drive gear 33 via a bearing 34, and the swivel base 14 is fixed to the upper surface of the slider 35. The swivel base 14 can rotate around this driving gear 33. A pinion 37 is rotatably attached to the output shaft 36 of the hydraulic motor 18, and the pinion 37 meshes with an internal tooth surface of the drive gear 33. Further, a shaft support 38 is fixed on the holding plate 19 and has an annular shape having approximately the same outer diameter as the holding plate 19.
A driven gear 39 is positioned on the inner periphery of the shaft support 38, which has an annular shape and whose outer diameter is approximately the inner diameter of the shaft support 38, and has a tooth profile cut on the inner periphery. A bearing 40 is interposed therebetween. Then, the aforementioned workbench 20 is placed and fixed on the upper surface of this driven gear 39, and then the workbench 20 is placed and fixed on the upper surface of this driven gear 39.
0 can rotate about the central axis of the shaft support 38 as its rotation center. A hydraulic motor 41 is fixed inside the holding plate 19 on the upper front surface of the swivel base 14, and an output shaft 42 of the hydraulic motor 41 has a pinion 4 attached thereto.
The pinion 43 is engaged with the inner tooth surface of the driven m wheel 39. Then, the motive vehicle 3 is placed on the support plate 13.
3, or a support 44 is fixed vertically, and an angle detector 45 is fixed to the bottom surface of the swivel base 14 that corresponds perpendicularly to the support 44. vessel 45
It's a matter of getting closer. A support 46 is also vertically fixed to the axis of the driven gear 39 on the swivel base 14.
An angle detector 47 is also fixed to the lower surface of the corresponding workbench 20, and the support column 46 and the angle detector 47 are placed close to each other. In addition, FIG. 6 is an exploded perspective view of the rotating member of this turning mechanism, and FIG. 7 is a plan view showing the positional relationship of the rotating member same as the above.

FIG. 8 is a block diagram of an electric circuit showing a rotation angle detection and control system in this embodiment. The aforementioned angle detector 45
．． Inside the disk-shaped magnetic disks 51, 52 and magnetic pickups 54.
The magnetic disk 51 is fixed to the top of the column 4.4, and the magnetic disk 52 is fixed to the top of the column 46.
The rotating table 141 rotates relative to the work table 20. The output of the magnetic pickup 53 is sent to a pulse generation circuit 55 which generates a number of pulses according to the input signal. The output of the magnetic pickup 54 is input to the gate circuit 58 via a frequency dividing circuit 57 that reduces the frequency of the buffer circuit 561 by half, and the output of the magnetic pickup 54 is input to the pulse generating circuit 59. The signal is input to the gate circuit 61 via the buffer circuit 6o. Next, reference numerals 62 and 63 are swing switches provided near the control box 25 to operate the hydraulic motors 18 and '41;
Both are exercised at the same time. This turning switch 6
2 is connected to a chattering prevention circuit 64, the chattering prevention circuit 64 is connected to a gate circuit 61 and a drive circuit 66 via a buffer circuit 65, and a relay 67 is connected to the drive circuit 66. be. A power supply is connected to one end of this relay 67, and a solenoid 68 is connected to the other end.
is connected. The swing switch 63 also has a chattering prevention circuit 69. A gate circuit 58 is connected via a buffer circuit 7o. The output of the gate circuit 61 is input to the count input T of the counter B71, the output of the gate circuit 58 is input to the count input T of the counter A72, and the outputs of both counters A72 and B71 are input to the comparison matching circuit. 73 is entered. The comparison and coincidence circuit 73 uses a counter A72. It discriminates the count output of B71, and there is a comparison output that is output when the surface outputs do not match, and a coincidence output J that is output when the surface outputs match.
The matching output J is input to the S end of the S flip-flop 74, and the coincidence output J is input to the R end of the RS flip-flop 74. R.S.
The Q output of the flip-flop 74 is connected to a drive circuit 75, and the drive circuit 75 is connected to a relay 76. One end of the relay 76 is connected to the Ki''i power supply, and the other end is connected to a solenoid 77. .

It is. Further, a one-shot multi-circuit 78 is connected to the 100 output of the RS flip-flop 74, and the output of the one-shot multi-circuit 78 is connected to the counter A72. It is input to each clear end CL of B71.

Next, FIG. 9 is a system diagram showing the hydraulic system of this embodiment,
The discharge path 82id of the hydraulic pump 81 is branched into two, L tear!
2. A throttle valve 83 is installed at the branch of this discharge passage 82.
．． The flow rate of the throttle valve 84 is set to twice that of the throttle valve 83 by connecting to the solenoid valves 85 and 86 through the solenoid valves 84 and 84. The solenoid valve 85 is operated by the solenoid 77, and the solenoid valve 86 is operated by the solenoid 68. The hydraulic motor 18 is connected to the solenoid valve 85, and the hydraulic motor 41 is connected to the solenoid valve 86.
A recovery path 87 is connected to the output ends of both hydraulic motors 18 and 41, and the terminal end of the recovery path 87 communicates with a pressure oil tank 88. This pressure oil tank 88 is filled with pressure oil, and the suction passage 89 of the hydraulic pump 81 is introduced into the pressure oil tank 88.

Next, the operation of this embodiment will be explained.

The operation of moving the packet 29 up and down to excavate the road and the ground is conventionally a separate operation, and the operator sitting on the seat 24 operates the control box 25 to control each hydraulic cylinder 30, 31, . 32 are made to work together and move. The excavated soil lifts the packet 29 horizontally as shown in FIG. 3, making the bottom surface of the packet 29 slightly higher than the top surface of the equipment on the swivel table 14, and in this state turns the packet 29 to the rear of the vehicle body 10. This allows it to be transferred to a truck, etc.

To rotate the swivel table 14 and workbench 20, use the swivel switch 62. By closing =-63, a turning instruction is given and chattering prevention circuits 64, 69, buffer circuits 65',
Pulses PC and Pd, which are generated only while the pivot switches 62 and 63 are closed, are transmitted to the drive circuit 66 and the gate circuits 58, 61 via the drive circuit 70, respectively. Therefore, the drive circuit 66 closes the relay 67 to supply current to the solenoid 68, operates the solenoid valve 86, and operates the hydraulic pump 81.
The hydraulic pressure is supplied to the hydraulic motor 41 through the throttle valve 84. Therefore, the output shaft 42 and the pinion 43 of the hydraulic motor 41 rotate, causing the meshed driven gear 39 to rotate along the shaft support 38. For this reason, the workbench 20 placed on the driven gear 39. The support body 21° excavation mechanism 47 is rotated relative to the swivel table 14.

Next, since the comparison-number circuit 73 outputs the comparison signal K (the condition is that it outputs the coincidence signal J before the rotation switch 62, 63 is pressed), the RS flip-flop 74 is inverted and the Q (M The signal is output and transmitted to the drive circuit 75, and the drive circuit 75 closes the relay 76 to supply power to the solenoid 77.When this solenoid 't7 is activated, the solenoid valve 77 becomes conductive, and the hydraulic motor 18 is turned on. Hydraulic pressure is supplied from the hydraulic pump 81 via the throttle valve 83 to the hydraulic motor 1.
8 works. When this hydraulic motor 18 operates, the output @
36. Since the pinion 37 rotates and turns the engaged gear of the driving gear 33, the slider 35 rotates along the driving gear 33, and the swivel base 14 turns with respect to the vehicle body 10.

Here, by setting the respective rotational directions of the hydraulic motors 18 and 41 in opposite directions, the rotational directions of the swivel table 14 and the workbench 20 are respectively reversed, and the excavation mechanism fixed on the workbench 20 is 47 often passes above the swivel base 14. In addition, the flow rate of the throttle valves 83 and 84 is
The valve 84 is set so that the rotation speed of the work platform 20 is twice the rotation speed of the swivel table 140. become.

When the above-mentioned swivel table 141 workbench 20 rotates, the angle detector 45.47 changes its angular position relative to the column 46.48, and the magnetic disk 51.52Fi column located within the angle detector 45. Since it is fixed at 46°48, it rotates within the angle detectors 45 and 47, and the magnetic pickups 53 and 54 both detect fluctuations in the magnetic poles set on the outer periphery of the magnetic disk 51 and 52 and convert it into an electrical signal. The signal is then transmitted to the pulse generation circuits 55 and 59. Pulse generation circuit 5
At 5°59, a pulse e whose waveform is shaped with a predetermined pulse width by the detection signal from the magnetic pickup 53.5.4 is generated.
'fr: Generated at every fixed rotation angle of the magnetic disk 51, 52. The pulse waves from the pulse generation circuits 55 and 59 are sent to the gate circuit 61 and the frequency dividing circuit 5 as angle signals pa and pb through the barrier circuits 56 and 60.
7 is output. In the gate circuit 61, the turning switch 62
While both the turning signal Pc and the pulse wave pb/ are being input, the pulse wave Pe, which is the same as the pulse wave Pb, is output, and the pulse wave Pe is input to the counter input T of the counter B71, and the pulse wave Pe is input by this counter B71. Count the number of pulses. The count output of counter B71 is compared -
It is transmitted to the number circuit 73. Next, the frequency of the angle signal Pa input to the frequency dividing circuit 57 is reduced to 1/2, and the frequency is reduced to 1/2.
/2 pulses are transmitted to the gate circuit 58, and in this gate circuit 58, while the turning signal Pd is input,
A pulse wave Pf having the same Hals number as a/2 is output, and the pulse wave Pf is input to the counter input T of the counter A72, and the number of pulses is counted by the counter A72. The count output of counter A72 is the comparison-number circuit 7
The comparison circuit 73 compares the count output from the counter B71 with this count output, and if the two outputs do not match, outputs a signal from the comparison output K. outputs multiple signals such as the coincidence output J.

When the comparison output K of the comparison-number circuit 73 is rlJ, the Q terminal of the RS flip-flop 7.4 continues to output rlj, and the hydraulic motor 18 continues to operate. As the hydraulic morph 18 continues to operate and rotate the swivel base 14, the rotation angle of the swivel base 14 becomes 1/1 of the rotation angle of the workbench 20.
2, the count outputs of counters A72 and B71 match, and the comparison and number circuit 73 outputs a match output J of "1".
”, the RS flip-flop 74 is reversed to set the Q terminal to “0”, the drive circuit 75 is stopped, and the relay 76 is
is opened to temporarily stop the operation of the hydraulic motor 18. As a result, the rotation of the swivel table 14 is temporarily stopped. At the same time, the terminal outputs "1", one-shot multi circuit 7
A pulse wave of a predetermined pulse width (F) is generated by the one-shot multi-circuit 78 by the counter A72.8. B7 is transmitted to each clear end CL of both counters A72. The count memory of B71 is reset to zero. Therefore, the counter A72. B71 starts counting the number of pulses of the pulse wave P6*Pf, and the comparison circuit 73 outputs the comparison output and the coincidence output J alternately, controls the solenoid 77 and the hydraulic motor 18 in a stepwise manner, and calculates the cumulative error. By making t smaller, a constant follow-up operation is always performed with respect to the operation of the hydraulic motor 14. Therefore, the magnetic disks 51, 52 always rotate at a ratio of 1:2, and therefore the swivel table 14 and the workbench 20 always rotate in a proportional relationship at a rotation angle of 1:2. Then, if the workbench 2o rotates as much as the rotation angle of the swivel table 14, then compare - number circuit 7
3 transmits the comparison output K to the RS flip-flop 74 and drives the drive circuit 75.3. Since the relay 76 and the solenoid 77 are operated to follow the hydraulic motor 18 and rotate it, the error in the rotation angle becomes extremely small.

By the rotation of these two hydraulic motors 18 and 41, the swivel base 1
4 and the workbench 2o will be explained with reference to FIG. Start ((a) in Figure 10). As mentioned above, since the rotation angles of the workbench 2° and the swivel table 14 are controlled, their rotational speeds are regulated at a ratio of 2:1. Therefore, the workbench 20 must rotate at twice the speed of the swivel table 14, and when the swivel table 14 rotates 90 degrees, the workbench 20 rotates 180 degrees, and since both rotate in the opposite direction, the workbench 20 is relatively rotatable by 90 degrees, and the excavator vi is positioned perpendicular to the vehicle body 10, as shown in FIG. 10(b). Therefore, the workbench 20 is maximally deviated to one side of the vehicle body 10, and the excavation mechanism 47 is located above the swivel base 14 and passes through the other side of the vehicle body 10 without protruding.

Furthermore, when the swivel table 14 is rotatable by 90 degrees, the work table 20 is rotated by 1
The workbench 20 is rotated 80 degrees and moved to the right side of the claw body 10, and the excavation mechanism 47 protrudes to the opposite side of the car body 10, and the 10th
Move to a position that is exactly the opposite of the state shown in the figure <<.

If the swing switch 62.63 is opened in the state shown in FIG. 10P), the hydraulic motor 18.41 stops its operation, and the swing table 141 and the work table 20 stop their rotation. In other words,
The excavation mechanism 47 receives the rotation movement of the turning metalwork 4 on the grass 10 and the rotation movement of the workbench 20 on the swivel table 14 in the opposite direction, so that the excavation mechanism 47 rotates doubly. When rotating from the front to the rear of the vehicle body 10, the vehicle body 10 always passes above the swivel base 14 and rotates, and the excavation mechanism 47 is rotated within the maximum range so as not to protrude to the side of the grass body 10. Become. To reverse the excavation mechanism 47 from the position (c) to the position (a) in FIG.
．． 63 is pressed again to rotate the swivel table 14 by 180 degrees, the same operation as described above is performed, and the swivel table 14 and the work table 20 are rotated at a constant ratio.

Since the present invention is configured as described above, it is possible to make the excavator's second kerato as eccentric as possible and turn it from the front to the rear, and since the packet does not protrude from the side of the vehicle body, it is possible to make the two kerats of the excavator as eccentric as possible and turn from the front to the rear. The road can be used efficiently without causing any hindrance, and without having the road occupied by excavation work.

Further, even if the width of the road is approximately the same as the width of the vehicle body, the packet etc. will not protrude from the vehicle body, so work can be carried out even under narrow usage conditions. The swivel table and the work table are each rotated by separate hydraulic motors, and the rotation angle position of both is detected by a rotation angle detection means, and the rotation angle of both is controlled to be a constant ratio. Moreover, the excavation mechanism is always on the swivel table; :F3 ib'4 j...
Since a complicated mechanical interlocking mechanism is often required, unnecessary stress is generated, and energy loss can be minimized.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of the present invention, Fig. 2 is a top view of the same as above, Fig. 3 is a front view of the same as above, Fig. 4 is a plan view of same as above, and Fig. 5 is a turning mechanism. FIG. 6 is an exploded perspective view showing the configuration of the turning mechanism of the same vehicle, FIG. 7 is an explanatory diagram showing the arrangement of the turning mechanism, and FIG.
9 is a block diagram showing the electrical control system, FIG. 9 is a piping diagram showing the hydraulic system, and FIG. 10 is an explanatory diagram showing the rotation order. 10...Vehicle body, 14...Swivel base, 20...
・Workbench, 18.41...Hydraulic motor, 47...
- Excavation mechanism, 45.47... Angle detector. Figure 3 12 1 Go to Figure 4 Figure 6 Figure 7 Figure 3

Claims (1)

[Claims] A swivel table that can rotate horizontally is provided above the movable power vehicle body, and a work table is installed on the top surface of the swivel table so that it can rotate freely, offset from the center of rotation of the swivel table, and an excavation mechanism is fixed to the work table. In the machine, a hydraulic motor for rotating the swivel table and a hydraulic motor for rotating the work table are provided separately, and a first rotation angle detection means for detecting the rotation angle of the swivel table and a rotation angle 'fc of the work table are provided. The two signals of the second rotation angle detection means are transmitted to the signal processing means, and the operations of the two hydraulic motors are controlled based on the results of the arithmetic processing by the processing means (a). A control mechanism for an excavator, characterized in that the excavator is operated while maintaining the rotational angular velocity of the platform and workbench at a predetermined ratio.