JPH031450B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention enables excavation of roads, etc., and narrows the turning range during the work to prevent other work from being done or from occupying the road, thereby hindering the progress of vehicles. In particular, an excavating mechanism that has a freely rotatable work platform mounted on a swivel platform, drives the swivel platform and the work platform using separate hydraulic rotation means, and is fixed on the platform. The present invention relates to a platform rotation drive device for an excavator that can greatly expand the degree of freedom.

In conventional excavators, the arm protrudes from the car body,
A bucket was attached to the tip of this arm to dig up the dirt, but with this configuration, when transporting the excavated dirt to the rear of the vehicle, the arm and bucket protrude far beyond the side of the vehicle and come into contact with people standing nearby. In addition to being dangerous, it also had the disadvantage of widening the work area. For this purpose, a swivel platform and a workbench are installed on the vehicle body with their rotational axes eccentric, and the bucket is passed above the vehicle body, and the excavation is configured so that the arm and bucket do not protrude far beyond the side of the vehicle. machine 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 bucket will not reliably pass over the vehicle body, 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 mechanical drive mechanism using gears, etc., but the stress was concentrated at one point, which could easily cause a failure. The power loss due to friction etc. was large and the efficiency was poor. For this reason, a mechanism has been proposed in which the swivel table and work table are rotated by separate motive power.With this new mechanism, the swivel table and work table rotate and stop independently, increasing the degree of freedom. . On the other hand, it is difficult to control the two driving forces (hydraulic motors) individually.

The invention has been made in view of the above-mentioned drawbacks, and its purpose is to enable the swivel platform and the work platform to operate separately, and to synchronize the swivel angles of both hydraulic rotation means when they are operated simultaneously. The object of the present invention is to provide a platform rotation drive device for an excavator that can perform the following steps.

In order to achieve the above object, the present invention places a freely rotatable workbench on a swivel table, allows the swivel table and the workbench to be driven by separate hydraulic rotation means, and rotates in response to an external command. When the platform and the workbench are operated separately or simultaneously, and both hydraulic rotation means are rotated simultaneously, the rotation angles of both are synchronized based on the position information of both.

As described above, in the present invention, the rotation of the swivel table can be set freely, and both can be rotated synchronously or independently, so that excavation work can be carried out over a wide range. .

Hereinafter, one embodiment of the present invention will be described based on the drawings.

Fig. 1 is a perspective view of an excavator to which an embodiment of the table rotation drive device according to the present invention is applied, Fig. 2 is a side view thereof, Fig. 3 is a front view thereof, and Fig. 4 is a plan view thereof. . This excavator is self-propelled, and wheels 11 are pivotally supported at the four corners of the lower surface of a flat car body 10, and track pillars (tracks) 12 are provided between each pair of wheels 11 on both sides of the car body 10. is wrapped around it. An annular support plate 13 is fixed to the center of the upper surface of the vehicle body 10, and a deformed octagonal 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 obtained by cutting each vertex of an equilateral triangle.
An engine 15, a fuel tank 16, and a hydraulic oil tank 17 are mounted and fixed along the periphery of the swivel table 14 at the rear (left side in FIGS. 2 and 4) upper part of the engine 4.
A hydraulic motor 18 serving as hydraulic rotation means is fixed at a position slightly closer to the fuel tank 16 than the center of the upper surface of the swivel base 14 with its drive shaft directed downward. A ring-shaped holding plate 19 is placed on the upper part of the front of the swivel table 14 (right side in Figs. 2 and 4).
The central axis of the supporting plate 13 and the central axis of the holding plate 19 are horizontally offset and parallel to each other. A circular workbench 20 is rotatably supported on the holding plate 19, and a support 21 is vertically fixed on the workbench 20.
Connectors 22 are fixed to the upper and lower sides at intervals. A proximal end body 26 is connected between the connectors 22, and a dogleg-shaped boom 27 is swingably connected to the proximal end body 26. An arm 28 is swingably connected to the tip of the boom 27. They are movably connected,
Furthermore, a bucket 29 is swingably connected to the tip of the arm 28. between the proximal body 26 and the center of the boom 27, between the center of the boom 27 and the arm 2.
Hydraulic cylinders 30, 31 and 32 are interposed between the arm 28 and the bucket 29, respectively. The boom 27, arm 28, bucket 29, etc. constitute an excavation mechanism 47. Further, a passenger platform 23 made of a steel plate bent into an L shape is fixed to one side of the base end body 26.
3, a seat 24 and a control box 25 are fixedly attached. Although not shown, the control box 25 is also provided with switches for giving commands to the control circuit of this embodiment.

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. A circular driving gear 33 having approximately the same outer diameter as the supporting plate 13 and having a tooth profile cut on its inner periphery is fixed on the support plate 13 described above, and a bearing 34 is mounted on the outer periphery of this driving gear 33. An annular slider 35 is rotatably fitted through the slider 35, and the swivel base 14 is mounted on the upper surface of the slider 35.
is fixed, and the swivel base 14 is connected to this driving gear 33.
It can be rotated around. A pinion 37 is rotatably attached to the output shaft 36 of the hydraulic motor 18, and the pinion 37 is meshed with an internal tooth surface of the driving gear 33. Further, a ring-shaped shaft support 38 is fixed on the holding plate 19 and has an outer diameter that is approximately the same as that of the holding plate 19. approximately the inner diameter of the shaft support 38;
A driven gear 39 having a tooth profile cut thereon is positioned on its inner periphery, and a bearing 40 is interposed between the shaft support 38 and the driven gear 39. The workbench 20 described above is mounted and fixed on the upper surface of the driven gear 39, and the workbench 20 can rotate about the central axis of the shaft support 38 as its rotation center. A hydraulic motor 4 is located inside the holding plate 19 on the front upper surface of the swivel base 14 and serves as a hydraulic rotation means.
1 is fixed, and a pinion 43 is rotatably attached to the output shaft 42 of this hydraulic motor 41, and the pinion 43 is meshed with the internal tooth surface of the driven gear 39. A column 44 is vertically fixed at the axis of the drive gear 33 on the support plate 13.
A rotary encoder 45 is fixed to the lower surface of the swivel base 14, which corresponds perpendicularly to , and the support column 44 and the rotary encoder 45 are placed close to each other. A support 46 is fixed vertically to the axis of the driven gear 39 on the swivel base 14, and a rotary encoder 47 is also fixed to the lower surface of the corresponding workbench 20, and the support 46 and the rotary encoder It is placed close to 47.

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 above.

FIG. 8 is a diagram showing a hydraulic circuit and a control circuit in this embodiment. A pump 51 driven by an engine (not shown) has its suction side connected to a hydraulic oil tank 17 that stores hydraulic oil.
A multiple valve 52 is connected to the discharge side of the oil pump 1, and a working oil tank 17 is connected to the discharge side of the multiple valve 52. The multiple valve 52 is configured such that the direction in which the working oil is delivered can be changed by operating a control lever 53. This multiple valve 52 has a flow control section 5.
The throttle valve 55 is connected to a control valve 59 in a switching section 57, and the throttle valve 56 is connected to a control valve 60 in a switching section 58. The control valves 59 and 60 are connected to each other. These control valves 59 and 60 can be switched between two systems by hydraulic pressure, one for supplying hydraulic pressure to the hydraulic motors 18 and 41, respectively, and the other for returning the hydraulic pressure and supplying it directly to the other control valves 59 and 60. It is something. This control valve 59 is connected to an automatic switching valve 63 that automatically changes the oil path direction depending on the flow direction of the pressure oil.The above-mentioned hydraulic motor 18 is connected to the automatic switching valve 63. Check valves 65 and 66 for retaining pressure oil are interposed between the and hydraulic motor 18 in opposite directions, respectively, and a pair of relief valves 69 and 70 are provided at both ends of the hydraulic motor 18 in parallel in opposite directions. It's connected. Similarly, the control valve 60 is connected to an automatic switching valve 64 that automatically changes the oil path direction according to the flow direction of the pressure oil, and the above-mentioned hydraulic motor 41 is connected to the automatic switching valve 64. , check valves 67 and 68 for holding pressure oil are interposed between the control valve 60 and the hydraulic motor 41 in opposite directions, and a pair of relief valves 71 and 72 are provided at both ends of the hydraulic motor 41 in opposite directions. They are connected in parallel in the direction. A part of the output of the above-mentioned hydraulic pump 51 is supplied to two-port relief valves 75 and 75 located in oil passage control units 73 and 74, respectively.
The two outputs of the solenoid valve 77 are connected to the control side of the control valve 59 through throttle valves 79 and 80, respectively, and the output of the solenoid valve 77 is The side is connected to the aforementioned relief valve 75 and oil tank. Similarly, the two outputs of the solenoid valve 78 are connected to the control side of the control valve 60 via throttle valves 81 and 82, respectively, and the discharge side of the solenoid valve 78 is connected to the aforementioned relief valve 76 and the oil tank. It has been done.

Further, reference numeral 83 is a control circuit, and rotational position detection signals 89 and 90 from the rotary encoders 45 and 47 are input to the control circuit 83. Inside the rotary encoders 45 and 47, a disk-shaped magnetic disk with magnetic poles arranged at equal intervals on the outer periphery and a magnetic pick-up are housed, respectively.The magnetic disk is fixed to the top of the support column 44; 46, and as a result, the magnetic disk rotates relative to the rotating table 14 and the work table 20. and,
Rotational position detection signal 89, 9 from magnetic pickup
It is now possible to obtain 0. The control circuit 83
takes in an instruction 85 given by an operation switch 84 operated by an operator from the outside, and according to the instruction 85, the oil passage switching means (57, 58, 7
Control signals 86 and 87 for switching and controlling the electromagnetic valves 77 and 78 (3, 74) can be output. When operating both hydraulic motors 18 and 41 in response to a command 85 from the operation switch 84, the control circuit 83 receives an information signal 85 indicating the operation direction of the operation lever 53, and also receives rotational position detection signals from the rotary encoders 45 and 47. 89 and 90
and the rotational position detection signals 89 and 90
is used as a position information signal for the swivel table 14 and the work table 20. Based on this, control signals 86 and 87 can be outputted to switch and control the solenoid valves 77 and 78 so that the rotation angles of the swivel table 14 and the work table 20 are synchronized. It's becoming like that.

FIG. 9 is a block diagram showing an example of the control circuit in this embodiment, and FIG. 10 is a functional block diagram of the control circuit.

In FIG. 9, the control circuit 83 includes a microprocessor unit 91 and a read-on memory 92 that stores programs for operating the microprocessor unit 91 in a predetermined order.
, a random access memory 93 for storing predetermined constants, external data, etc., and digital input ports 94 to 94 for inputting external digital signals.
97, a digital output port 98 that outputs digital signals, and a bus 99 that connects these.

This control circuit 83 is functionally configured as shown in FIG.

A rotational position detection signal 89 from the rotary encoder 45 is input to an up-down counter circuit 101 via a gate circuit 100. Similarly, a rotational position detection signal 90 from the rotary encoder 47 is input to an up-down counter circuit 103 and a counter circuit 104 via a gate circuit 102. The position of the operating lever 53 is inputted to the up/down counter circuits 101 and 103 after the operating direction information number 88 is shaped by the waveform shaping circuit 105, and the up or down count of the circuit is designated. The counter circuits 101 and 103
The count output of is supplied to the comparison circuit 106.

Further, the count output of the counter circuit 101 is input to a comparison circuit 107 and a latch memory 108. The count output of the counter circuit 103 is input to a comparison circuit 109 and a latch memory 110. The comparison circuit 107 receives an output signal from the latch memory 108 when there is an output command. Similarly, the comparator circuit 109 receives an output signal from the latch memory 110 when there is an output command.

The count output of the counter 104 is input to a comparison circuit 111. A reference angle signal set in the digit switch 112 is input to the comparison circuit 111 . When a match signal is output, the comparison circuit 111 uses it as a stop signal and also uses it as a reset signal for each of the counters 101, 103, and 104.

A match signal 114 from the comparison circuit 106 is input to a stop signal selection circuit 113. Furthermore, match signals 115 and 116 from comparison circuits 109 and 110 are input to stop signal selection circuit 113. The match signal from comparison circuit 106 is input to stop signal selection circuit 117.

Output signals 118 and 119 from stop signal selection circuits 113 and 117 are input to drive circuits 120 and 121 for driving solenoid valves 78 and 77, respectively. These drive circuits 120 and 121 are designed to turn on the solenoid valves 78 and 77 when the output signals 118 and 119 are logic "0".

The operation switch 84 has a circuit configuration as shown, for example, and can select "automatic" or "manual", and when "manual" is selected, "synchronous operation", "work platform only operation", or ``Only the processing stand is operated''
You can choose.

When the operation switch 84 is set to "auto", the signals 114, 115, etc. from the comparison circuits 106, 107, and 109 are transferred to the selection circuits 113 and 1.
17 and connected to the circuit 122 and/or the preset switch 123 and/or 1
24, the latch memory 108 and/or
Alternatively, the values of the counters 101 and 103 are stored in 110. Therefore, from now on, the value stored in the latch memory 108 and the counter 101
The comparison circuit 107 compares the count value with the count value of .
Further, the comparison circuit 10 compares the value stored in the latch memory 110 and the count value of the counter 103.
9 to be compared. As a result, the swivel base 14 and the work platform 20 automatically stop between certain positions between the stored values.

When the operation switch 84 is selected as "synchronous operation", "work platform only operation", or "swivel platform only operation", "manual" is selected from "automatic". When the operation switch 84 is selected to "operate only the rotary table", the signal is input to the drive circuit 121 via the OR circuit 126, the drive circuit 121 operates, the solenoid valve 77 is turned off, and the solenoid valve 78 is turned off. Turns on. On the other hand, when the operation switch 84 is selected to "operate only the workbench", the signal is input to the drive circuit 120 via the OR circuit 125, the drive circuit 120 is operated, and the solenoid valve 78 is turned off. is turned on. Furthermore, the operation switch 8
4 is selected as "synchronous operation", the comparison circuit 106
The output of is selected by selection circuit 113, and latch memories 108 and 110 are inactivated. In this case, the count values from counters 101 and 103 are compared in comparison circuit 106, and when they do not match, solenoid valves 77 and 78 are turned off, and when they match, solenoid valve 77 is turned on and solenoid valve 78 is turned off.

Note that limit switches 127 and 128 are configured to operate when a certain angle is reached.
This is supplied to gate circuits 100 and 102 via waveform shaping circuits 129 and 130. The circuits 100 and 102 are connected to the rotary encoder 4.
Supply/non-supply of the signals 89 and 90 from the counters 5 and 47 to the counters 101 and 103 is controlled based on the signals from the waveform shaping circuits 129 and 130. The control circuit is configured as described above.

Next, the operation of this embodiment will be explained.

The operation of moving the bucket 29 up and down to excavate the road and the ground is a conventionally known operation.
By operating the control box 25, an operator aboard the vehicle 4 causes the hydraulic cylinders 30, 31, and 32 to move in cooperation with each other. The excavated earth and sand are lifted horizontally as shown in Fig. 3, the lower surface of the bucket 29 is slightly higher than the top surface of the equipment on the swivel base 14, and in this state the bucket 29 is swiveled to the rear of the vehicle body 10. This allows it to be transferred to a truck, etc.

Next, the swivel base 1 is driven by the hydraulic motors 18 and 41.
4. The turning operation of the workbench 20 will be explained. Since there are three types of this turning operation, the setting conditions for each case will be explained separately.

(1) First, when the operation switch 84 is selected to "synchronous operation" and the swivel base 14 and work platform 20 are operated in synchronized rotation.

The selection circuits 113 and 117 select the output signals of the comparison times 106 and 107, respectively, and supply them to the drive circuits 120 and 121. In the comparisons 106 and 107, a mismatch signal is output, so the solenoid valves 78 and 77 are turned off. Since the solenoid valves 77 and 78 are turned off, the oil passages are parallel, thereby keeping the control valves 59 and 60 in the supply state.

Part of the hydraulic pressure generated by the hydraulic pump 51 is supplied to relief valves 75, 76 and electromagnetic valves 77, 7.
8 through control valves 59, 60, respectively.
is transmitted to one of the control valves 59, 6.
0 are each held at the supply position. In this state, when the multiple valve 52 is operated to the "positive" position, the oil pressure is changed to the throttle valve 55 and the control valve 59.
The hydraulic pressure is transmitted to the drive unit 61 via the automatic switching valve 63, and the automatic switching valve 63 is switched from neutral to conductive. At the same time, the hydraulic pressure is transmitted to the hydraulic motor 18 from the check valve 66, passes through the switched automatic switching valve 63, and is controlled. It flows to valve 59. The hydraulic oil that has passed through the hydraulic motor 18 enters the control valve 60 from the control valve 59, switches the automatic switching valve 64, and at the same time passes through the check valve 68 and is transferred to the hydraulic motor 41.
It passes through the automatic switching valve 64, the control valve 60, and then the throttle valve 5.
6. Recovered to oil tank 17 via multiple valve 53. From this, the multiple valve 52
By operating , a flow path is formed in one order, and the hydraulic motors 18 and 41 are connected in series and rotated. When this hydraulic motor 18 operates, the output shaft 36 and pinion 37 rotate, which rotates the gear of the driving gear 33 that meshes with the hydraulic motor 18, so that the slider 35 rotates along the driving gear 33, and the swivel base 14 rotates around the vehicle body 10. It will rotate against. When the hydraulic motor 41 operates at the same time, the output shaft 42 of the hydraulic motor 41 and the pinion 4
3 is a shaft support 3 that rotates and meshes the driven gear 39.
Rotate along 8. For this reason, driven gear 3
The workbench 20, support body 21, and excavation mechanism 47 placed on the swivel table 14 are rotated. 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 4 fixed on the workbench 20 is rotated in opposite directions.
8 will pass above the turning table 14.
In addition, the capacities of the hydraulic motors 18 and 41 and the number of teeth of the pinions 37 and 43, the driving gear 33, and the driven gear 39 are set in advance, so that the rotational speed of the workbench 20 is twice the rotational speed of the swivel table 14. It's like this.

The relative relationship between the swivel table 14 and the workbench 20 due to the operation of these two hydraulic motors 18 and 41 will be explained with reference to FIG. 11. The workbench 20 is rotated in the X direction in the figure by the hydraulic motor 41. start,
The swivel table 14 starts to rotate in the Y direction in the figure by the hydraulic motor 18 (A in FIG. 11). As mentioned above, the rotation angle of the work table 20 and the swivel table 14 is determined by the capacities of the hydraulic motors 18 and 41, respectively. pinion 3
Since the number of teeth is set to 7, 43, etc., the rotation speed is regulated at a ratio of 2:1. Therefore,
The workbench 20 will rotate at twice the speed of the swivel base 14, and when the swivel base 14 rotates 90 degrees, the workbench 20 will rotate 180 degrees, and since the two are rotating in the opposite direction, the workbench 20 will rotate at a relative speed. After being rotated 90 degrees, the excavating mechanism is positioned perpendicular to the vehicle body 10, resulting in the state shown in FIG. 11B. Therefore, the workbench 20 is maximally deviated to one side of the vehicle body 10, and the excavation mechanism 48 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 rotates 90 degrees, the work table 20
After rotating 180 degrees, the workbench 20 moves to the right side of the vehicle body 10, and the excavation mechanism 48 protrudes to the opposite side of the vehicle body 10, moving to a position exactly reversed from the state shown in FIG. 11A.

By the way, when the multiple valve 52 is operated in the "positive" direction, an information signal 88 specifying up or down is supplied to the counters 101 and 103 via the waveform shaping circuit 105, and the counters 101 and 103 are turned into an up counter or a down counter. Specify as a down counter. Next, as described above, when the hydraulic motors 18 and 41 operate, the rotary encoders 45 and 47 operate and their rotational position detection signals 89 and 90 are output to the counter 1.
01 and 103. The counter 1
The count values of 01 and 103 are calculated by the comparator circuit 10.
6 is compared. When the counter values of both counters 101 and 103 match in the comparison circuit 106,
Turn on the solenoid valve 78. At this time, solenoid valve 7
7 remains off. Further, when the comparison circuit 106 determines that the count values of both counters 101 and 103 do not match, the solenoid valves 77 and 78 are turned off. Therefore, when the multiple valve 52 is operated in the "normal" position, the swivel table 14 remains in rotational operation, and when the count values do not match, the workbench 20 turns off the solenoid valve 78 and performs rotational operation. When the count values match, the solenoid valve 78 is turned on to prevent rotation.

If the multiple valve 52 is returned to its original state in the state shown in FIG. 10C, the hydraulic motors 18 and 41 will stop operating, and the swivel table 14 and work table 20 will stop rotating. In other words, the excavation mechanism 48 receives the rotation movement of the swivel table 14 on the vehicle body 10 and the rotation movement of the work table 20 on the swivel table 14 in the opposite direction, so that the excavation mechanism 48 rotates doubly. When rotating from the front to the rear of the vehicle body 10, the excavation mechanism 48 always passes above the swivel base 14 and rotates, and rotates within the maximum range so as not to protrude the excavation mechanism 48 to the side of the vehicle body 10. It turns out. To reverse the excavation mechanism 48 from the position C to the position A in FIG. 11, a multiple valve 52 is used.
If you operate the swivel table 14 again and rotate the swivel table 14 by 180 degrees, the same operation as described above will be performed, and the control circuit 83
operates in the same manner, and the swivel table 14 and work table 20 are rotated synchronously at a constant ratio.

(2) When operating the operation switch 84 to rotate only the swivel base 14.

When the operation switch 84 is selected to "operate only the swivel base", the signal is input to the drive circuit 121 via the OR circuit 126, and the solenoid valve 77 is turned off. At this time, the solenoid valve 78 is on. Therefore, the solenoid valve 77 is turned off,
Since the solenoid valve 78 is turned on, the control valve 59 is in the supply state, and the control valve 60 is in the supply state.
becomes a turning state.

A part of the hydraulic pressure generated by the hydraulic pump 51 is transmitted to the control valves 59 and 60 via the relief valves 75 and 76, but the control valve 59 is maintained in the same state as described above, and the control valve 60 is transmitted to the solenoid valve 78. When the control valve 60 is switched by changing the port, the control valve 60 forms a turn-around oil passage inside the control valve 60 and prevents hydraulic oil from flowing to the hydraulic motor 41. In this state, when the multiple valve 53 is operated from the "neutral" to the "positive" position, the pressure oil from the hydraulic pump 51 is transferred to the multiple valve 53, throttle valve 55, control valve 59, check valve 66, hydraulic motor 18, and automatic switching. valve 63,
The flow goes through the control valve 59, the control valve 60, the throttle valve 56, and the multiple valve 53 in this order, and returns to the oil tank 52.
Only 8 works. Therefore, only the output shaft 36 and pinion 37 rotate to rotate the engaged driving gear 33, so the slider 35 rotates along the driving gear 33 and moves only the swivel base 14 to the vehicle body.
It will be rotated with respect to 0, and the rotating base 14
The rotary table 20 and excavation mechanism 48 placed on the vehicle body 10 protrude to the side of the vehicle body 10 while facing forward, resulting in the state shown in FIG. 12. For this reason, the excavation mechanism 48 is moved up and down by the car body 10, and the car body 10
Excavation work can be performed in a direction perpendicular to the direction of.

(3) When operating the operation switch 84 to rotate only the workbench 20.

When the operation switch 84 is selected to "operate only the workbench", the signal is input to the drive circuit 120 via the OR circuit 125, and the solenoid valve 78 is turned off. At this time, the solenoid valve 77 is on. Therefore, the solenoid valve 77 is turned on,
Since the solenoid valve 78 is turned off, the control valve 59 is in the folded state and the control valve 60 is in the supply state.

The hydraulic pressure generated by the hydraulic pump 51 is transmitted to the control valves 59 and 60 via some of the relief valves 75 and 76, but the control valve 59 is switched by changing the solenoid valve 78 port, and the control valve 60 is A folded oil passage is formed inside to prevent hydraulic oil from flowing to the hydraulic motor 18, and the control valve 60 is maintained in the state shown in FIG. In this state, when the multiple valve 53 is operated from the "neutral" position to the "positive" position, the pressure oil from the hydraulic pump 51 is transferred to the multiple valve 52, the throttle valve 55, the control valve 59, the control valve 60, the check valve 68, and the hydraulic motor. 4
1. The flow goes through the automatic switching valve 64, the control valve 60, the throttle valve 56, and the multiple valve 52 in this order, and returns to the oil tank 52, and the hydraulic motor 4
Only 1 works. Therefore, the output shaft 42 and pinion 43 rotate, causing the engaged driven gear 39 to rotate along the shaft support 38. For this reason, the workbench 20 and support body 2 placed on the driven gear 39
1. The excavation mechanism 47 is rotated relative to the swivel base 14, but since the hydraulic motor 18 is not activated, the swivel base 14 is not rotated, and the excavation mechanism 47 is rotated by the angle that is operated relative to the swivel base 14. I end up shaking my head. This state of shaking your head is the first
3, the rotating platform 14 is stopped facing the front of the vehicle body 10, but only the work platform 20 rotates, and the excavation mechanism 47 can be swung in a fan shape in front of the vehicle body 10. It is possible to excavate not only the front center of the vehicle body 10 but also both front sides of the vehicle body 10.

(4) When operating the operation switch 84 to perform automatic operation.

When operating switch 84 is selected to ``auto'', latch memories 108 and 110 are enabled. Also, the above selection allows the comparison circuit 101
The output of is supplied to the drive circuit 121 via the selection circuit 117. Similarly, the comparison circuit 10
The comparison outputs of 6 and 109 are the selection circuit 11
7 to the drive circuit 120. This turns off the solenoid valves 77 and 78.

Then, by operating the switches 123 and 124, the output signals of the counters 101 and 103 are stored in the latch memories 108 and 110 as initial positions. Next, the multiple valve 52 is operated to rotate the swivel table 14 and the work table 20. In this case, the count values of counters 101 and 103 are compared by comparison circuit 106, thereby controlling the synchronous operation described in item (1) above.
Further, when the swivel base 14 is at a predetermined position, the switch 123 is operated to set the counter 1 to a predetermined position.
When the count value of 01 is stored in the latch memory 108 as the position information, the swivel base 14 stops. Even if a match signal is output from the comparison circuit 106, there is no match signal from the comparison circuit 109, so the solenoid valve 78 is turned off, and the workbench 2
0 continues to rotate as is. When the workbench 20 is at a predetermined position, the switch 124 is operated and the count value of the counter 103 is stored in the latch memory 110 as position information. As a result, a matching signal is output from the comparison circuit 109, the solenoid valve 78 is turned on, and the workbench 20 is stopped. From then on, simply use multiple valve 5.
2, both machines 14 and 20 will rotate repeatedly between two predetermined points in a synchronous operation state.

According to this embodiment, accurate synchronized operation and automatic operation are achieved. Further, the functions shown in FIG. 10 according to this embodiment can be realized by the microcomputer shown in FIG. 9 above.

Although this embodiment has been constructed digitally, it goes without saying that it can be constructed analogously.

As described above, according to the present invention, since it is configured as described above, the bucket belt of the excavator can be made as eccentric as possible and can be turned from the front to the rear, and the bucket belt does not protrude from the side of the vehicle body. The road can be used efficiently without interfering with the operation of other lanes and without having the road occupied by excavation work. Further, according to the present invention, the rotation of the swivel platform and the work platform can be freely set by switching the oil passages, and both can be rotated synchronously or independently, and the synchronous rotations are reliably synchronized. This has the advantage that excavation work can be performed over a wide range and that synchronous rotation is accurate.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one embodiment of the present invention;
The figure is a side view of the same as above, Figure 3 is a front view of the same as above, and Figure 4 is a front view of the same as above.
The figure is a plan view of the same as the above, Figure 5 is a sectional view taken along arrow A-A in Figure 4 showing the turning mechanism in detail, Figure 6 is an exploded perspective view showing the configuration of the turning mechanism of the above, and Figure 7 is the turning mechanism. FIG. 8 is an explanatory diagram showing the arrangement of the mechanism; FIG. 8 is a hydraulic circuit showing piping of the hydraulic system; FIG. 9 is a block diagram of a control circuit according to an embodiment of the present invention; FIG. 10 is a functional block diagram of the control circuit; Figures 11A to 1C are explanatory diagrams showing the order of rotation in a synchronized state, Figure 12 is an explanatory diagram showing the case where the swivel platform is deviated at a predetermined angle with respect to the vehicle body, and Figure 13 is an explanatory diagram showing the case where the work platform is rotated. FIG. 3 is an explanatory diagram showing a case where the work is performed while being deviated at a predetermined angle with respect to the table. 10...Vehicle body, 14...Swivel base, 20...Work table, 18, 41...Hydraulic motor, 45, 47...
Rotary encoder, 59, 60... Control valve, 63, 64... Automatic switching valve, 77, 78...
...Solenoid valve, 83...Control circuit, 84...Operation switch, 85...Command.

Claims (1)

[Scope of Claims] 1. A swivel table that can rotate horizontally is provided above the movable vehicle body, and a work table is rotatably provided on the top surface of the swivel table, offset from the center of rotation of the swivel table.
In an excavator with the excavation mechanism fixed to the workbench,
Hydraulic rotation means for independently rotating the swivel table and work platform, and both hydraulic rotation means are connected in series, and each hydraulic rotation means is provided with an oil passage switching means for bypassing pressure oil in parallel. A hydraulic circuit that operates one or both of the hydraulic rotation means depending on the combination of the switching states of the road switching means, a position detection means that detects the positions of the swivel platform and the work platform, and The oil passage switching means controls the switching of the switching means and synchronizes the rotation angles of the swivel platform and the work platform based on the rotational position detection signal from the position detection means when operating both hydraulic circuit means. A table rotation drive device for an excavator, characterized in that it is configured to include a control circuit that performs switching control. 2. The platform rotation drive device for an excavator according to claim 1, wherein the position detection means is a rotary encoder that detects the rotational position of the swivel platform and the work platform.