JPH0324535B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is used for excavating roads, the ground, etc., and the rotating range is widened by doubly rotating a rotating platform and a work platform in opposite directions. Regarding excavators that can be narrowed,
In particular, the present invention relates to a turning control mechanism for an excavator that can prevent the excavating mechanism from turning below a predetermined height during turning and damaging other equipment on the turning table.

[Prior Art] Excavation work using a conventional excavator will be explained with reference to FIG. FIG. 1 shows the state of work in which a conventional excavator 1 is used to dig a trench in only one lane of a two-lane road.

In this case, the excavation work is carried out on only one of two lanes, and the excavator 1 is installed within the width of one lane and occupies only this lane. and,
During excavation work, arm 2 is moved up and down,
Dig the shovel 3 at the tip of the road below the road surface,
The grooves 4 can be formed sequentially. In this excavation work, the earth and sand excavated by the bucket 3 must be placed on the platform of a truck 5 waiting behind the excavator 1 by rotating the arm 2. In order to sequentially dig this groove 4 in the length direction of the lane, the excavator 1 must be moved backward (in the direction of arrow Z) to prevent the excavator 1 from falling into the groove 4.

In such excavation work, the arm 2 and bucket 3 must be rotated in order to transfer the excavated earth and sand to the truck 5, but the center of rotation is the point X, which is the center of the excavator 1. .
Therefore, the turning radius of the bucket 3 at the tip of the arm 2 is indicated by Y in FIG. 1, and the area within this Y is the dangerous range. Since the arm 2 extends in this dangerous range Y, it will invade the adjacent lane where no excavation is being performed. Therefore, when the arm 2 and the bucket 3 turn, the arm 2 or the bucket 3 will collide with a vehicle traveling in the adjacent lane, and the vehicle passing in the adjacent lane will not dig to prevent danger. Either the vehicle must be brought to a complete stop, or the vehicle must be temporarily stopped only when the arm 2 is turned.

In this way, in excavation work using conventional excavators, it is necessary to completely or temporarily stop the operation of vehicles in the adjacent lane where the excavation is not being carried out.
The normal flow of vehicles was stagnant, which was unfavorable from both the economics of transportation and road occupancy.

For this purpose, a movable vehicle body, a swivel base that is pivoted so that the center of rotation coincides with approximately the center of the upper surface of the vehicle body, and can make a full horizontal turn;
On this swivel table, there is a work table which is rotatably supported so that the center of rotation is separated from the center of rotation of the swivel table so that it can fully turn horizontally, and an excavation mechanism placed on the work table. An excavator has also been proposed in which the rotating platform and work platform are rotated in opposite directions. In this configuration, the rotation direction of the swivel table and the rotation direction of the work table are opposite, so the excavation mechanism including the bucket can be passed on the swivel table. It can be stored inside. This mechanism has the feature that the bucket does not protrude into the adjacent lane and does not stop the operation of vehicles in the adjacent lane. (For example, Showa 57
Patent Application No. 128468, etc.).

[Problem that the invention seeks to solve]

However, with this newly proposed excavator, the excavation mechanism must be passed on the swivel table and rotated, so if the excavation mechanism rotates below a predetermined height, the bucket of the excavation mechanism will be placed on the swivel table. Equipment (e.g. engine cover, oil tank, etc.)
This could lead to accidents such as damage or deformation of these devices. For this reason, the operator of this excavator has to turn while paying attention to the height position of the excavating mechanism during work, which increases the burden of attention and makes the work cumbersome.

The present invention provides a height detecting means on the swivel table, and forcibly stops the turning operation of the swivel table and the work platform if the excavation means is below a predetermined height when turning.
The present invention provides a swing control mechanism for an excavator that can prevent damage caused by contact with equipment.

[Means for solving problems]

The present invention provides a movable vehicle body, a swivel base that is pivotally supported so that the center of rotation is aligned with approximately the center of the upper surface of the vehicle body, and it can fully turn horizontally;
On this swivel table, there is a work table which is rotatably supported so that the center of rotation is separated from the center of rotation of the swivel table so that it can fully turn horizontally, and an excavation mechanism placed on the work table. An excavator comprising: a detection means for detecting the height from the vehicle body to the excavation mechanism; a drive means for rotating the swivel; and a control means for stopping the operation of the drive means in response to a signal from the detection means; The present invention is characterized by a swing control mechanism for the excavator that can stop the operation of the driving means when the excavation mechanism is below a predetermined height when the excavation mechanism is turned, and can prevent the excavation mechanism from coming into contact with the vehicle body. be.

[Effect]

In this mechanism, when rotating the excavation mechanism including the bucket and arm, it is lifted to a higher position than the rotating table and then double-swiveled in the horizontal direction. If the excavation mechanism is above the normal height position, the excavation mechanism will pass over the swivel table. if,
When the excavation mechanism is at a normal height position or lower and starts turning in that state, the height detection means detects the abnormal height and stops the turning operation of the turning table. Therefore, the excavation mechanism does not collide with the equipment provided on the swivel table, and damage to the equipment can be prevented.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a perspective view of the excavator of this embodiment, FIG. 3 is a side view, FIG. 4 is a front view, and FIG. 5 is a plan view.

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 crawlers (tracks) are installed between each pair of wheels 11 on both sides of the car body 10. 12 is wound. An annular support plate 13 is mounted and fixed at the center of the upper surface of the vehicle body 10.
A swivel table 14 having a modified octagonal shape is rotatably supported on the entire circumference in the horizontal direction.

This swivel base 14 has a planar shape obtained by cutting out each vertex of an equilateral triangle, and has a planar shape obtained by cutting each vertex of an equilateral triangle.
On the upper part of the swivel table 14 (left side in FIG. 5), equipment such as an engine 15, a fuel tank 16, a hydraulic oil tank 17, etc. are mounted and fixed in a slightly U-shape along the periphery of the swivel base 14. Further, 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 swivel base 14 with its drive shaft directed downward. An annular holding plate 19 is mounted and fixed on the upper part of the front of the swivel table 14 (right side in Figs. 3 and 5), and the central axis of the above-mentioned support plate 13 and this holding plate 19 It is horizontally offset from the central axis of , and the two are positioned parallel to each other.

On this holding plate 19 is a disk-shaped work table 20.
is rotatably supported horizontally on the holding plate 19 around the entire circumference. A support 21 is vertically fixed on the workbench 20, and a pair of connectors 22 are fixed to the side surfaces of the support 21 at intervals above and below. A proximal body 26 is provided between both connectors 22.
A slightly dogleg-shaped boom 27 is connected to the base end body 26 so as to be able to swing up and down, and an arm 28 is connected to the tip of the boom 27 so as to be able to swing up and down. Furthermore, a bucket bag 29 is swingably connected to the tip of the arm 28.
Hydraulic cylinders 30, 31, and 32 are interposed 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 bucket 29, respectively. . These boom 27, arm 28, bucket 29, etc. constitute an excavation mechanism 47.

Further, a riding body 23 made of a steel plate bent into an L shape is fixed to one side of the base end body 26, and a seat 24 and an operating lever 25 are fixed to the riding body 23. Then, on each side of the fuel tank 16 and the hydraulic oil tank 17, the swivel base 14
Detection mechanisms 48 and 49 are respectively attached to the front surface (right side in FIGS. 3 and 5) for detecting abnormal height.

Next, FIG. 6 shows in detail the structure of the turning mechanism in this embodiment, and corresponds to the cross section taken along the line A--A in FIG. 5.

On the support plate 13 mentioned above, the outer diameter is approximately the same as that of the support plate 1.
A circular driving gear 33 having the same diameter as 3 and having a tooth profile on its inner periphery is fixed, and a ring-shaped slider 35 is rotatably fitted to the outer periphery of this driving gear 33 via a bearing 34. The swivel base 14 is fixed to the upper surface of the slider 35, and the swivel base 14 can rotate around the driving gear 33. The output shaft 36 of the hydraulic motor 18 protrudes toward the lower surface of the swivel base 14, and a pinion 3 is attached to the output shaft 36.
7 is attached to the shaft, and the pinion 37 is connected to the driving gear 33.
It is meshed with the inner tooth surface of. Further, an L-shaped shaft support piece 38 is fixed to the lower surface of the swivel base 14 and located on the inner peripheral side of the driving gear 33.
Bearings 39 and 40 are installed on the and swivel base 14, respectively.
is fixed thereto, and an intermediate shaft 41 pivotally supported by both bearings 39 and 40 passes through the upper and lower surfaces of the swivel base 14. A pinion 42 is fixed to the intermediate shaft 41 between the shaft support piece 38 and the swivel base 14.
The pinion 42 is meshed with the internal tooth surface of the driving gear 33.

Further, a ring-shaped shaft support 43 having an outer diameter that is approximately the same as that of the holding board 19 is fixed on the holding plate 19, and the outer diameter is substantially supported on the inner periphery of the shaft support 43. An annular driven gear 45 having an inner diameter of the body 43 is rotatably inserted. A tooth profile is cut on the inner periphery of the driven gear 45, and a bearing 44 is interposed between the shaft support 43 and the driven gear 45 to ensure smooth rotation. The workbench 20 described above is mounted and fixed on the upper surface of the driven gear 45, and the workbench 20 rotates about the central axis of the shaft support 43 as its rotation center. Further, a pinion 46 is fixed to the upper end of the aforementioned intermediate shaft 41, and this pinion 46 meshes with the internal tooth surface of the driven gear 45. In addition, FIG. 7 is an exploded perspective view showing the rotating member of this turning mechanism, and FIG.
The figure is a plan view showing the horizontal positional relationship of the rotating members same as above.

Next, FIG. 9 shows the detection mechanism 49 (detection mechanism 4
8 also have the same structure, so only one is shown) is shown in detail.

A pair of support pieces 51 and 52 are projected from the lower side of the hydraulic oil tank 17 at intervals, and between the support pieces 51 and 52 both ends of a U-shaped actuation lever 53 are connected to pins 54 and 52, respectively. 55, they are swingably connected. The actuating lever 53 is formed by bending a round pipe into a U-shape, and is arranged so that both ends of the U-shape are located downward and the center side is horizontal at the top. This operating lever 5
The upper side of 3 is set at a slightly higher position than the upper surface of the hydraulic oil tank 17, and a round biasing pipe 56 is installed between the two sides on both sides. A spring 57 is interposed between the side wall of the hydraulic oil tank 17 and the biasing pipe 56, and the spring 57 constantly biases the operating lever 53 in a direction away from the side wall of the hydraulic oil tank 17.
The operating lever 53 is always slightly inclined toward the workbench 20. Further, a limit switch 58 is fixed to the side wall of the hydraulic oil tank 17, and the pushing part of this limit switch 58 is opposed to one side of the operating lever 53, so that the operating lever 53 is opposed to the spring 57. It is in a position where it can be turned on when it swings.

Moreover, FIG. 10 is a hydraulic control circuit diagram in this embodiment. In this circuit diagram, only the control system of the hydraulic motor 18 is shown, and connections to other hydraulic equipment such as an excavation mechanism are omitted.

The rotational output of the engine 61 is transmitted to a hydraulic pump 62, and the discharge output of the hydraulic pump 62 is transmitted to a three-way switching type control valve 63.
The suction side of is connected to a hydraulic oil tank 17. Normally open switching valves 64 and 65 are connected to the output of the control valve 63, respectively.
A balance valve 66 and a check valve 73 are connected in parallel between the switching valve 65 and one side of the hydraulic motor 18, and a balance valve 67 and a check valve 74 are connected between the switching valve 65 and the other side of the hydraulic motor 18. are connected in parallel. A counterbalance valve 68 is formed by the pair of balance valves 66 and 67. Furthermore, relief valves 69 and 70 are connected in parallel and in opposite directions between both ends of the hydraulic motor 18, and check valves 71 and 72 are connected in parallel to the switching valves 64 and 65, respectively. . The switching valves 64 and 65 are operated by electromagnetic solenoids, and have two types of operation: on and off, and are normally in communication, but are turned off when a signal is input. And the switching valve 6
4 is operated by a limit switch 58, and the switching valve 65 is operated by a limit switch 59.

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.
This is done by an operator onboard the vehicle operating the control bar 25 to cause the hydraulic cylinders 30, 31, and 32 to move in cooperation with each other. The earth and sand excavated by the bucket 29 are collected by holding the bucket 29 slightly horizontally as shown in Fig. 3, with the bottom surface of the bucket 29 slightly higher than the top surface of the equipment on the swivel base 14, and in this state, placing the bucket 29 on the vehicle body. By turning it backwards, it can be transferred to a truck or the like.

Moving the bucket 29 from the front side of the vehicle body 1 to the rear side means rotating the entire excavation mechanism 47 with respect to the vehicle body 1, and the rotation of the excavation mechanism 47 is caused by the rotation of the swivel table 14 and the work platform 20. It is acted upon.

First, the operation in the hydraulic circuit will be explained.

When the engine 61 operates, the hydraulic pump 62 is driven, and the hydraulic oil tank 1 is driven by the hydraulic pump 62.
7 and outputs it to the control valve 63. This control valve 63 has three types of blocks, and the A block can be manually switched to forward rotation, the B block to stop, and the C block to reverse rotation. The B block is normally in a stopped position, and in this state, the hydraulic pressure discharged from the hydraulic pump 62 passes through the control valve 63 and returns to the hydraulic oil tank 17, and the hydraulic motor 18 does not rotate.

Here, when the control valve 63 is switched to the A block, the hydraulic oil discharged from the hydraulic pump 62 passes through the switching valve 64 and the check valve 73 and is transmitted to the hydraulic motor 18, and the hydraulic oil that has passed through the hydraulic motor 18 is The oil passes through the balance valve 67, the switching valve 65, and the control valve 63, returns to the hydraulic oil tank 17, and the hydraulic motor 18 is driven.

Next, the mechanical operations of the turning table 14 and the work table 20 will be explained.

As mentioned above, when hydraulic oil is supplied to the hydraulic motor 18, the output shaft 36 rotates, the pinion 37 rolls on the internal tooth surface of the drive gear 33, and the slider 35
is rotated along the outer periphery of the drive gear 33. As a result, the swivel base 14 fixed to the slider 35 rotates about the central axis of the drive gear 33 as its rotation center. When the swivel base 14 rotates, the intermediate shaft 41 is pivotally supported on the swivel base 14, so the pinion 42 is caused to roll along the internal tooth surface of the drive gear 33, and the rotation of the pinion 42 causes the intermediate shaft 41 to rotate. The pinion 46 is rotated in proportion to the amount of rotation of the swivel base 14. When the pinion 46 is driven and rotated, the driven gear 45 meshed with the pinion 46 is rotated, and the driven gear 45 is rotated along the inner periphery of the shaft support 43. For this reason, the driven gear 4
The workbench 20 and excavation mechanism 47 placed on 5 are also rotated.

The rotation direction of this driven gear 45 is determined by the pinion 42,
46, it is rotated in the opposite direction to the rotation direction of the swivel table 14. At the same time, an excavation mechanism 47 such as a boom 27, an arm 28, and a bucket 29 protruding from the base body 26
Since the excavation mechanism 47 rotates in the opposite direction to the vehicle body 10, the excavation mechanism 47 rotates about two axes with respect to the vehicle body 10. Therefore, when turning, the excavating mechanism 47 is drawn to one side of the vehicle body 10 and makes a double turn, and can move from the front to the rear of the vehicle body 10 without the bucket 29 etc. protruding from the side of the vehicle body 10. In other words, the excavation mechanism 47 is
The excavating mechanism 47 rotates from the front of the vehicle body 1 toward the rear due to the rotating motion on the rotating base 14 and the rotating motion of the work platform 20 in the opposite direction on the rotating base 14. At times, the excavating mechanism 47 always passes above the swivel base 14 and rotates, so that the excavating mechanism 47 can be swiveled within a minimum range so as not to protrude to the side of the vehicle body 10.

When the excavation mechanism 47 rotates, if the lower surface of the bucket 29, etc. at the lowest position is located above the upper surface of the engine 15, fuel tank 16, and hydraulic oil tank 17, the bucket 29, etc. will not touch these devices. Turn smoothly without collisions. However, if the worker does not lift the boom 27 and arm 28 sufficiently and turns the bucket 29 etc. at a lower height position than the upper surface of the hydraulic oil tank 17, the bucket 29 etc. It comes into contact with an actuating lever 53 provided on the side of 17.
When the bucket 29 or the like comes into contact with this operating lever 53, the operating lever 53 is moved by the spring 5 due to its rotational force.
The pins 54 and 55 are made to pivot against the compressive force of 7. Therefore, the operating lever 53 approaches the hydraulic oil tank 17 and finally pushes the limit switch 58.

When the limit switch 58 is pushed, the switching valve 64 is closed, the hydraulic oil from the hydraulic pump 62 no longer flows to the hydraulic motor 18, and the operation of the hydraulic motor 18 is stopped. Therefore, the rotating table 14 and the work table 20 stop their rotation, and the excavating mechanism 47 stops just before colliding with the side surface of the hydraulic oil tank 17.

When the limit switch 58 is actuated, the hydraulic motor 18 will no longer rotate in the normal rotation direction. In order to reset this state and make it rotate again, the control valve 63 is switched to the C block and hydraulic oil is supplied to the switching valve 65. Then, the hydraulic oil flowing from the hydraulic motor 18 passes through the check valve 71 and is transmitted to the control valve 63, causing the hydraulic motor 18 to rotate in the reverse direction, and the excavating mechanism 47, which was in contact with the operating lever 53, to move away. Limit switch 58 is opened. Therefore, when the limit switch 58 is opened, the switching valve 64 is returned to its original position, and the balance valve 66 and control valve 63 are directly connected, allowing forward rotation.

Next, the worker turns the boom 27 and the arm 28 and lifts the bucket 29 to a higher position, so that the excavation mechanism 47 moves over the engine 15, fuel tank 16, and hydraulic oil tank 17 on the swivel table 14. It is possible to pass and turn to the rear of the vehicle body 10. Note that when the excavation mechanism 47 rotates in the opposite direction to that described above when the bucket 29 etc. are in a low position, the limit switch 59 of the detection mechanism 48 provided on the side of the fuel tank 16 is pushed, and the hydraulic pressure is increased in the same way. Rotation of the motor 18 in the opposite direction can be stopped.

〔Effect of the invention〕

Since the present invention is constructed as described above, the excavation mechanism can be made to be eccentric to one side of the vehicle body as much as possible and can be rotated in a double manner, thereby eliminating the need for the bucket or the like to protrude from the side surface of the vehicle body. Therefore, the operation of vehicles in the lane next to the lane in which excavation work is being performed is not hindered, and the excavation work does not occupy a road with multiple lanes. Further, even if the road is approximately the same width as the vehicle body, the bucket and the like do not protrude from the vehicle body, so excavation work can be carried out even under narrow usage conditions where the left and right sides are surrounded by walls.

Further, even if the swivel table is rotated when the height of the excavation mechanism is at a low position, the height detection means can detect the height of the excavation mechanism and automatically stop the rotation operation. Therefore, it is possible to prevent the excavation mechanism from colliding with the equipment on the swivel table, and it is possible to prevent accidents such as damage or deformation of the excavator itself.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing excavation work by a conventional excavator, Fig. 2 is a perspective view showing an embodiment of the excavator according to the present invention, Fig. 3 is a side view of the same, and Fig. 4 is a front view of the same. 5 is a plan view of the same as above, FIG. 6 is a sectional view taken along the arrow A-A in FIG. 5 showing the turning mechanism in detail, and FIG. 7 is an exploded perspective view showing the configuration of the turning mechanism of the above FIG. 8 is an explanatory diagram showing the arrangement of the turning mechanism in a horizontal position, FIG. 9 is a partial perspective view showing an enlarged detection means, and FIG. 10 is a hydraulic circuit diagram showing the connection of the hydraulic control system. DESCRIPTION OF SYMBOLS 10...Vehicle body, 14...Swivel base, 18...Hydraulic motor as driving means, 20...Working table, 4
7... Excavation mechanism, 48, 49... Detection means, 6
4, 65...Switching valve as control means.

Claims (1)

[Scope of Claims] 1. A movable vehicle body, a swivel base that is pivoted so that the center of rotation coincides with approximately the center of the top surface of the vehicle body, and the vehicle can fully turn horizontally; is an excavator consisting of a work platform that is rotatably supported so that it can rotate completely horizontally with its center of rotation separated from the center of rotation of the swivel platform, and an excavation mechanism placed on the work platform. , a detection means for detecting the height from the vehicle body to the excavation mechanism, a drive means for rotating the swivel table, and a control means for stopping the operation of the drive means in response to a signal from the detection means, when the excavation mechanism is turned. A swing control mechanism for an excavator that can stop the operation of a drive means when the excavation mechanism is below a predetermined height to prevent the excavation mechanism from coming into contact with a vehicle body.