JPH06102905B2 - Boom type work implement work implement posture detection device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work implement posture detection device for a boom type work machine.

(Prior Art) A boom type work machine that is used by being mounted on a vehicle body such as a tractor,
For example, in a front loader or the like, a pair of left and right booms pivotally supported on the vehicle body by a horizontal shaft so as to be vertically rotatable are connected by a horizontal connecting pipe, and the tip of the boom detects the inclination angle of the bucket to the ground. There is provided a sensor including a control sensor such as a single sensor and a second sensor that detects a tilt angle of the bucket with respect to the boom, and the attitude of the bucket is controlled by a signal from the control sensor during work.

In this type of working machine, each sensor is generally attached to an appropriate portion of the working machine while being exposed to the outside.

(Problems to be solved by the invention) Conventionally, since the sensor was mounted outside in an exposed state, the sensor may be hit by obstacles, earth and sand during work, and may be damaged by strength and reliability. There is. Further, according to the structure in which the sensor is protected by the protection member to ensure reliability, a separate protection member is required, which is structurally complicated and causes a cost increase.

In view of such problems of the related art, the present invention has a structure that protects a sensor by using a part of an existing working machine, while ensuring the reliability of the sensor and preventing an increase in manufacturing cost. It is intended.

(Means for Solving the Problems) As a first means therefor, the present invention provides a horizontal connecting pipe 18 that connects a pair of left and right booms 13 pivotally supported by a horizontal shaft 12 on the vehicle body 1 side. A boom-type working machine in which the working tool 16 is rotatably provided on the tip of the boom 13 by the horizontal shaft 15 and the posture of the working tool 16 is controlled by signals from the control sensors 19 and 20. In which the control sensors 19 and 20 are stored in the connecting pipe 18, and the second
As a means of this, a pair of left and right booms 13 pivotally supported by a horizontal shaft 12 on the vehicle body 1 side are connected by a horizontal connecting pipe 18, and a work tool 16 is attached to the horizontal shaft 15 at the tip of the boom 13. A first sensor 19 for detecting the inclination angle of the work implement 16 with respect to the ground, and a second sensor 20 for detecting the inclination angle of the work implement 16 with respect to the boom 13; Second
In a boom type working machine in which the posture of the work implement 16 is controlled by signals from the sensors 19 and 20, the first and second sensors 19 and 20 are stored in the connecting pipe 18, and the outside of the connecting pipe 18 is stored. Mounting plate 23 that closes the end opening from the outside
And having an actuation link 26 and said first and second sensors
A horizontal shaft 22 interlocking with 19, 20 is provided rotatably around this axis, and a rod 45 for connecting the operation link 26 and the working tool 16 is provided.

(Operation) Since the first and the sensors 19 and 20 are housed in the connecting pipe 18, they are protected by the connecting pipe 18.

When the work implement (bucket) 16 rotates about the horizontal shaft 15 during the work, the first and second sensors 19, 20 operate via the rod 45, the operation link 26, and the horizontal shaft 22. Then, the first sensor 19 detects the ground inclination angle of the work implement (bucket) 16, and the second sensor 20
Detects the relative tilt angle of the work implement (bucket) 16 with respect to the boom 13.

(Example) Hereinafter, the present invention will be described in detail with reference to the illustrated example.
In the figure, 1 is a tractor body, 2 is front wheels, 3 is rear wheels,
4 is a hood, 5 is a rear wheel fender, 6 is a driver's seat, and 7 is a steering wheel. A front loader 8 is a mast 10 which is detachably provided on both sides of the tractor vehicle body 1 via a mounting base 9 and a brace 11 which extends forward from the mast 10 and is detachably fixed to a front end portion of the tractor vehicle body 1. A boom 13 pivotally supported on the upper end of the mast 10 by a horizontal shaft 12 so as to be vertically rotatable,
Boom cylinder 14 for raising and lowering boom 13, boom
A bucket (working tool) 16 pivotally supported by a horizontal shaft 15 at the tip of 13 and a bucket cylinder 17 for rotating the bucket 16. The mast 10, the brace 11, the boom 13, the boom cylinder 14, and the bucket cylinder 17 are paired on the left and right, and the pair of left and right booms 13 are shown in FIGS.
As shown in the drawing, they are connected by a connecting pipe 18 in the lateral direction on the front side of the bonnet 4. In addition, connecting pipe
Reference numeral 18 penetrates the boom 13 in the lateral direction, and its outer end portion is slightly projected outward from the boom 13.

The connecting pipe 18 has a cylindrical shape with openings at both ends. Inside the connecting pipe 18, as shown in FIGS. 3 to 6, a first sensor 19 for detecting a ground inclination angle of the bucket 16 and a bucket.
Second sensor for detecting the relative tilt angle of the 16 to the boom 13
20 and are stored. The first sensor 19 uses a magnetic fluid, the second sensor 20 uses a potentiometer, and the first sensor 19 is attached to a U-shaped bracket 21. The bracket 21 is fixed to an inner end of a horizontal shaft 22, and the horizontal shaft 22 is rotatably supported by boss portions 24 and 25 fixed to a mounting plate 23 and has an operation link 26 at an outer end. On the side of the bracket 21 opposite to the horizontal axis 22, a horizontal axis 27 located on the same axis as the bracket is fixed. The second sensor 20 is attached to a U-shaped bracket 28, and its rotation shaft 29 is connected to the horizontal shaft 27. The horizontal shaft 27 is rotatably inserted into a boss portion 30 fixed to a U-shaped bracket 28, and the bracket 28 is fixed to a mounting plate 23. The mounting plate 23 has a substantially rectangular shape, and with the first and second sensors 19 and 20 stored in the connecting pipe 18, two bolts are attached to a pair of boss portions 31 welded to the outer surface of the boom 13. Installed by 32. The mounting plate 23 has notches 33 at four corners, and among the notches 33 at the four corners, one notch 33a is formed larger than the other notches 33. The mounting plate 23 is mounted so that the outer end opening of the connecting pipe 18 is closed from the outside so that dirt and the like do not enter, and a tube extraction space 34 is formed on the lower side. First and second
The lead wires 35, 36 of the sensors 19, 20 are connected to harnesses 39, 40 via connectors 37, 38, and the harnesses 39, 40 are covered with a corrugated tube 41 for protection. The corrugated tube 41 is provided in the connecting pipe 18 with a sufficient margin so as not to interfere with the rotation of the first sensor 19 in the connecting pipe 18 and the like. It is led out from the tube extraction space 34 to the outside of the connecting pipe 18 via the lower side. And this corrugated tube 41
Is clamped by the mounting plate 23 and the boom 13 between the connecting pipe 18 and the one boss portion 31, and is slightly fixed by pressing, and the clip 43 is attached to the hydraulic pipe 42 of the bucket cylinder 17.
It is also stopped by and is guided to the tractor body 1 side along a hydraulic pipe inside the boom 13.

The end of the operation link 26 is connected to a joint 46 at one end of a rod 45 via a pin 44, and the joint 47 at the other end of the rod 45 is connected to a bracket 49 on the back surface of the bucket 16 via a pin 48. The rod 45 is arranged substantially parallel to the upper edge side of the boom 13 in a close state, and the horizontal shafts 15, 22 and the pins 46, 48 are arranged so as to form the four links of the parallel link mechanism.
When the bucket 17 rotates around the horizontal shaft 15 due to expansion and contraction of the bucket cylinder 17, the horizontal shaft 22 rotates by the same angle.

As shown in FIG. 7, the first sensor 19 has a magnetic fluid 51 enclosed in a bottomed cylindrical container 50 made of a non-magnetic material, and cylindrical permanent magnets 52 and 2 arranged around the outer periphery of the container 50. Coils
53 and 54 are fitted in, and when they are rotated around the horizontal axis 22, the distribution of the magnetic fluid 52 changes as shown in FIG.
The output voltage of 3,54 changes in proportion to the inclination angle to ground. A lid 55 is fitted on the container 50, and the first sensor 19 is housed in a case 56a.

The second sensor 20 rotates in proportion to the inclination angle of the bucket 16 with respect to the boom 13 when the horizontal shaft 22 rotates in conjunction with the bucket 16 and the rotary shaft 29 rotates via the bracket 21 and the horizontal shaft 27. The output voltage changes accordingly.

Reference numeral 56 denotes an operating device, which is a case 57 mounted on the rear wheel fender 5 at one side of the driver's seat 6 as shown in FIGS. 9 to 12.
In addition, the operation lever 5 that can be operated back and forth, left and right, and diagonally
8. First and second potentiometers 59, 60 and the like which are interlocked with the operating lever 58 are incorporated. That is, the operating lever 5
8 is pivotally supported by a movable frame 61 via a horizontal shaft 62.
Is supported on the case 57 side via the front-rear shaft 63, and therefore the operating lever 58 can be operated in any direction as shown in FIG. 12 with the two axes of the horizontal shaft 62 and the front-rear shaft 63 orthogonal to each other as fulcrums. It is like this. The operating lever 58 is elastically held in the neutral position by a spring (not shown). The first potentiometer 59 is for instructing the raising and lowering of the boom 13, and is interlocked with the longitudinal movement of the operating lever 58 via the horizontal shaft 62,
In addition, a command signal having a voltage corresponding to the operation amount of the operation lever 58 is output. The second potentiometer 60 is for instructing the rotation of the bucket 16, and is interlocked with the left and right movements of the operation lever 58 via the front-rear shaft 63 and the movable frame 61, and has a voltage corresponding to the operation amount of the operation lever 58. Output a command signal.

Push-button type automatic changeover switch on top of operation lever 58
64 is installed. A hemispherical operating portion 65 is provided at the lower end of the operating lever 58, and a bottom portion inside the case 57 is
A raising switch 66, a lowering switch 67, a dump switch 68, and a scooping switch 69 are provided on the front, rear, left, and right around the actuating portion 65. Each of these switches 66 to 69 is operated by the operating lever 58.
Is operated by the operating part 65 when the maximum amount of is operated. Incidentally, 70 is a flexible cover.

Reference numeral 71 is a stand for supporting the front loader 8 with the bottom surface of the bucket 16 grounded after the front loader 8 is removed from the tractor body 1, and a connecting rod 72 for connecting the upper end portions of the mast 10 with each other. , Another supporting rod 73. Connecting rod 27
Is detachably attached to the bracket 49 of the bucket 16 with pins 74, and the supporting rod 73 is detachably attached to the middle of the connecting rod 72 and the boom 13 with pins 75 and 76. The notch 33a of the mounting plate 23 is notched up and down when the mounting plate 23 is mounted, and is notched larger than the others so as not to interfere with the supporting rod 73 when the stand 71 is used.

FIG. 14 shows a hydraulic circuit of the lift cylinder 14 and the bucket cylinder 17, and 77 is a first solenoid valve for controlling the lift cylinder 14, which has an ascending solenoid 78 and a descending solenoid 79. 80 is the second solenoid valve that controls the bucket cylinder 17,
It has a rake solenoid 82 and a dump solenoid 81.
The solenoid valves 77 and 80 are of the proportional type.

FIG. 15 shows a control circuit for driving and controlling the solenoid valves 77, 80.
In FIG. 15, reference numeral 83 is an ascending / descending discriminating circuit for discriminating the operation direction of the boom 13 by the positive / negative of the voltage signal from the first potentiometer 59. Discriminate the descent when the direction is negative. Reference numeral 84 is a first voltage-current conversion circuit for converting the voltage signal from the first potentiometer 59 into a current signal, so as to drive the ascending solenoid 78 or the descending solenoid 79 in the direction discriminated by the ascending / descending discrimination circuit 83. Has become. Reference numeral 85 denotes a tilt storage circuit, which reads and stores the tilt signal from the first sensor 19 when the automatic changeover switch 64 is turned on and the operating lever 58 is operated in the upward direction. ing. A first deviation / amplification circuit 86 obtains and amplifies the deviation between the tilt signal from the first sensor 19 and the tilt storage signal from the tilt storage circuit 85. Reference numeral 87 is a target value setting circuit for setting a target value at the time of horizontal grounding in which the bottom surface of the bucket 16 is ground parallel to the ground. Reference numeral 88 denotes a second deviation / amplification circuit, which obtains and amplifies the deviation between the angle signal from the second sensor 20 and the target value from the setting circuit 87. 89 is an automatic manual switching circuit, which switches from manual to automatic when the automatic changeover switch 64 of the operating lever 58 is pressed to turn it on, and selects the first deviation / amplification circuit 86 by the rising signal from the rising / falling discrimination circuit 83. Then, the posture holding control is performed, and the second deviation / amplification circuit 88 is selected by the descending signal to perform the horizontal grounding control. 90 is a scoop / dump discriminating circuit that discriminates the operating direction of the bucket 16 by the positive / negative of the voltage signal sent from the second potentiometer 60, the first deviation / amplification circuit 86 or the second deviation / amplification circuit 88 via the switching circuit 89. When the signal from the switching circuit 89 is positive, the scooping is performed, and when the signal is negative, the dump is discriminated. Reference numeral 91 is a second voltage-current conversion circuit that converts the voltage signal from the switching circuit 89 into a current signal, and drives the rake solenoid 82 or the dump solenoid 81 in the direction discriminated by the rake / dump discriminating circuit 90. There is.

In the above configuration, when the operation lever 58 is operated in the upward or downward direction during manual control, the first potentiometer 59
Positive or negative voltage signal is output from the up / down discrimination circuit
The first voltage-current conversion circuit 84 converts the voltage signal into a current signal, and the first solenoid valve 77.
The ascending solenoid 78 or the descending solenoid 79 is driven.
At this time, since the first solenoid valve 77 is of the proportional type, it is switched to ascend or descend in proportion to the absolute value of the voltage signal, and the boom 13 ascends or descends at a speed proportional to the operation amount of the operation lever 58.

When the operating lever 58 is operated in the scooping or dumping direction, the positive or negative voltage signal from the second potentiometer 60 causes the second electromagnetic wave via the scooping / dumping discrimination circuit 90 and the second voltage-current conversion circuit 91. The valve 80 switches to the scoop or dump direction and the bucket 16 scoops or dumps in the same manner as described above.

When scooping earth and sand into the bucket 16, the bucket 16 is grounded horizontally on the bottom surface, and then the operation lever 58 is slightly rotated in the scooping direction to be in the state of the phantom line in FIG. At this time, since the bucket 16 rotates about the horizontal shaft 15 in the direction indicated by the arrow a, the operating link 26 rotates about the horizontal shaft 22 via the rod 45 as indicated by b in FIG.
The first sensor 19 turns in the tilted state as shown in FIG. 8 by rotating in the direction of the arrow, and outputs a negative voltage signal according to the ground tilt angle of the bucket 16.

Therefore, when the automatic changeover switch 64 of the operation lever 58 is pushed and operated in the ascending direction, the boom 16 ascends while the bucket 16 maintains the posture of the phantom line in FIG. To do. That is, the automatic changeover switch
When 64 is pressed, the switching circuit 89 switches to the automatic side, and the tilt storage circuit 85 stores the tilt signal from the first sensor 19, that is, the tilt posture of the bucket 16 at the start of rising.
Further, since the operating lever 58 is operated in the ascending direction, the ascending / descending discriminating circuit 83 discriminates the ascending and the switching circuit 89 selects the first deviation / amplifying circuit 86 side. Then, when the boom 13 starts to rise, if the bucket 16 remains in the fixed state, the first sensor 19 further tilts, and the tilt signal becomes large on the negative side, so the first deviation / amplification circuit 86 The deviation between the tilt signal from the first sensor 19 and the tilt storage signal from the tilt storage circuit 85 is obtained and amplified. Since the deviation signal at this time is negative, the scoop / dump discriminating circuit 90 discriminates the dump, and the second voltage
The dump solenoid 81 of the second solenoid valve 80 is driven via the current conversion circuit 91, and the bucket 16 rotates in the dump direction. When the bucket 16 rotates in the dump direction, the operation link 26 rotates around the horizontal shaft 22 in the direction opposite to the arrow b direction via the rod 45, and the first sensor 19 returns to the state shown in FIG. 1 When the tilt signal from the sensor 19 matches the tilt storage signal of the tilt storage circuit 85, the dump operation of the bucket 16 is stopped. Hereafter, the boom works while correcting the attitude of the bucket 16 by the same function.
13 rises.

After dumping the bucket 16 at the raised position of the boom 13 to discharge the earth and sand, when lowering the boom 13, push the automatic changeover switch 64 and operate the operating lever 58 in the lowering direction to make the bottom surface of the bucket 16 horizontal. Ground to. That is, when the operation lever 58 is operated in the descending direction, the up / down discriminating circuit 83
Discriminates the fall, the switching circuit 89 selects the second deviation / amplification circuit 88 side. Then, if the bucket 13 is in the dumping state, the second state is passed through the rod 45, the operation link 26, the horizontal shaft 22, etc.
The sensor 20 detects the tilt angle of the bucket 16 with respect to the boom 13, and the second deviation / amplification circuit 88 determines the deviation between the tilt signal at that time and the target value of the setting circuit 87. Since the deviation signal in this case is positive, the rake / dump discrimination circuit 90 discriminates the rake, drives the rake solenoid 82 of the second solenoid valve 80 via the second voltage-current conversion circuit 91, and the bucket 16 is Rotate to the rake side. When the bucket 16 rotates in the scooping direction, the operating link 26 rotates around the horizontal shaft 22 in the direction of the arrow b via the rod 45, and the inclination signal of the second sensor 20 approaches the target value. Then, when the tilt signal from the second sensor 20 matches the target value, the tilt angle of the bucket 16 with respect to the boom 13 becomes an angle at which the bottom surface of the bucket 16 horizontally touches the ground at the lowered position of the boom 13, and the bucket 16 moves. Stop the rake action. Therefore, the bucket 16 can be grounded horizontally on the bottom surface simply by lowering the boom 13.

Since the first sensor 19 and the second sensor 20 are housed inside the connecting pipe 18, the first sensor 19 and the second sensor 20 do not come into contact with earth and sand and other obstacles, and the reliability is remarkably improved. Further, since the structure is such that the connecting pipe 18 protects the sensors 19 and 20, and the existing members are used as they are, there is no need to separately provide a protective member, and the cost increase can be prevented.

Further, the first sensor 19 for detecting the inclination angle of the bucket 16 with respect to the ground
And the second sensor 20 for detecting the inclination angle of the bucket 16 with respect to the boom 13 are arranged on the same axis of the horizontal shaft 22, and are linked to the bucket 16 via the operation link 26 and the rod 45. Is easy, especially with interlocking system such as rod 45
There is an advantage that it can be shared by individuals. Further, since the rod 45 is arranged close to the upper edge side of the boom 13 and in substantially parallel therewith, there is little contact with obstacles, and even if it comes into contact with it, it is not greatly separated from the boom 13, so the rod 45 is slightly It can be deformed to a very small extent. In this case, boom 13 and rod
The distance from 45 is such that it does not interfere with the connecting rod 72 of the stand 71 when removed. The connecting rod 72 may be arranged inside or outside the rod 45.

When mounting the mounting plate 23, the corrugated tube 41 is lightly pressed against the boom 13 side by tightening the bolt 32 to fix it. Therefore, the corrugated tube 41 can be fixed without a fixing tool. Since the mounting plate 23 closes the open end of the connecting pipe 18 leaving the tube extraction space 34, it is difficult for the mounting plate 23 to enter into the connecting pipe 18, such as earth and sand, and even if it enters, it does not stagnate inside, and the front loader 8 swings to the left and right. It can be discharged naturally during operation. Further, since the harnesses 39, 40 and the like inside the connecting pipe 18 can be confirmed from the tube extraction space 34, the disassembling work can be omitted.

Although the working link 26 and the bucket 16 are connected by the rod 45 in the embodiment, a push-pull cable or the like may be used. Further, instead of the bucket 16, a fork or the like may be attached as a work tool, and the invention can be applied not only to the front loader 8 but also to a backhoe or the like.

In Fig. 14, the boom cylinder 14 and the bucket cylinder are
Although a hydraulic circuit in which 17 and 17 are connected in parallel has been illustrated, a hydraulic circuit in which they are connected in series as shown in FIG. 16 can be similarly implemented.

(Effect of the Invention) According to the present invention, a connecting pipe that connects the left and right booms 13
Since the sensors 19 and 20 are housed inside the sensor 18, the reliability of the sensors 19 and 20 is improved, and it is not necessary to separately provide a protective member, which prevents an increase in manufacturing cost.

The first sensor for detecting the inclination angle of the work implement 16 with respect to the ground
19 and a second sensor 20 for detecting the inclination angle of the work implement 16 with respect to the boom 13 are interlocked with the horizontal shaft 22, and the horizontal shaft 22 is interlocked with the work implement 16 via an operation link 26. Therefore, the working tool 16 and the operation link 26 are also used as an interlocking system,
Different types of detection signals can be taken out from the first and second sensors 19 and 20, and the structure can be simplified and the cost can be reduced.

[Brief description of drawings]

The drawings show an embodiment of the present invention, in which FIG. 1 is a side view of the whole, and FIG. 2 is an inclined view of a front portion of a front loader.
3 is a side view of the sensor mounting portion, and FIG. 4 is A- in FIG.
A view from the arrow A, FIG. 5 is a view from the arrow BB of FIG. 3, FIG. 6 is an exploded perspective view of the sensor mounting portion, FIG. 7 is a sectional view of the first sensor, and FIG. Fig. 9 is a rear view of the operating device, Fig. 10 is a rear view of the same section, Fig. 11 is a view taken along the line CC of Fig. 10, and Fig. 12 is a view taken along the line D-D of Fig. 10. FIG. 13 is an explanatory view of an operating position, FIG. 14 is a hydraulic circuit diagram, FIG. 15 is a control circuit diagram, and FIG. 16 is a hydraulic circuit diagram. 1 ... tractor body, 8 ... front loader, 13 ... boom, 16 ... bucket, 18 ... connecting pipe, 19 ... first
Sensor, 20 …… Second sensor, 22 …… Horizontal axis, 23 …… Mounting plate, 26 …… Actuation link, 45 …… Rod.

Claims (2)

[Claims] 1. A pair of left and right booms (13) pivotally supported by a horizontal shaft (12) on a vehicle body (1) side are connected by a horizontal connecting pipe (18), and a boom (13) is also provided. Boom-type work in which the work tool (16) is rotatably provided at the tip of the robot by the horizontal axis (15) and the posture of the work tool (16) is controlled by signals from the control sensors (19) (20). In the machine, a work tool posture detection device for a boom type work machine, characterized in that control sensors (19) (20) are housed in a connecting pipe (18). 2. A pair of left and right booms (13) pivotally supported by a horizontal shaft (12) on the vehicle body (1) side are connected by a horizontal connecting pipe (18), and a boom (13) is also provided. A work tool (16) is rotatably provided on the tip end of the work piece by a horizontal axis (15), and a work is performed on a boom (13) and a first sensor (19) for detecting the inclination angle of the work tool (16) to ground. A second sensor (20) for detecting the inclination angle of the tool (16) is provided, and the posture of the work tool (16) is controlled by signals from the first and second sensors (19) (20). In the boom type working machine, a mounting plate that stores the first and second sensors (19) (20) in the connecting pipe (18) and closes the outer end opening of the connecting pipe (18) from the outside. (23) has an actuation link (26) and has the first
A horizontal shaft (22) interlocking with the second sensor (19) (20) is rotatably provided around the shaft center, and a rod (45) connecting the operation link (26) and the working tool (16). ) Is provided, a work implement posture detecting device for a boom type working machine.