JPH08166233A - Mechanism of detecting angle of work machine - Google Patents

Abstract

PURPOSE: To provide a mechanism of detecting angle of a work machine which can surely avoid a breakdown. CONSTITUTION: A bucket 2 is driven by a bucket cylinder 4 installed at an arm 1 through drive links 5 and 6. The drive link 5 rotates, with a pin 7 as a rotary shaft. The pulley of a pulley structure 10 is fixed to the drive link 5 and rotates around the pin 7. A pull cable is fixed to the pulley, and this pull cable is led to a bucket angle detector 14, being guided by an outer casing 13. By the drive of the bucket 2, the drive link 5 and the pulley rotate, and this rotation is transmitted to the bucket angle detector 14 by the pull cable, and the angle is detected. The bucket angle detector 14 can be installed separately from the bucket, so the breakdown by sand, etc., can be avoided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an angle detector mounted on a work machine, and more particularly to a work machine angle detection mechanism suitable for a work machine used in a harsh environment.

[0002]

2. Description of the Related Art In many working machines equipped with a link mechanism composed of a plurality of links, a control device is mounted and a desired work is performed under the control of the control device. An example of such a working machine is a hydraulic excavator. A hydraulic excavator usually has a link mechanism including three links of a boom, an arm, and a bucket, and excavation and various other operations are performed by individually operating the boom, the arm, and the bucket. During these operations, in the case of excavation work, it is extremely difficult to operate the link mechanism to excavate the ground along a linear trajectory or any other trajectory,
The control device appropriately controls the drive speed of the hydraulic cylinders that drive the links of the link mechanism to perform arbitrary excavation. The control device is used not only for such excavation control but also for other various controls.

In the above control device, control based on various detection values is performed according to the control purpose, but the detection value of the relative angle of each link of the link mechanism is often used as the detection value. The detection of the relative angle is essential in control. This relative angle is detected by fixing the angle detector to one link at the connecting portion (rotation axis position) of each link, connecting the rotation axis of this angle detector and the other link with a joint, and This is done by applying the same rotation as the relative rotation to the rotary shaft.

[0004]

By the way, since the link mechanism of the working machine constitutes a working part, it is common that earth and sand or rocks frequently come into contact with the working part during such work, and such contact causes an angle. The detector and the joint were often damaged and the relative angle could not be detected.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems in the prior art and to provide an angle detecting mechanism for a working machine capable of reliably avoiding damage.

[0006]

In order to achieve the above object, the present invention provides a working machine having a plurality of links constituting a working section, the pulley rotating with the rotation of the links, and the pulley. An angle detection mechanism of the working machine is composed of a displacement detector installed at an arbitrary position on the working machine apart from the above, and a cable fixed to the pulley and transmitting the rotation of the pulley to the displacement detector. Is characterized by.

[0007]

When the link rotates, the pulley rotates with it, and the rotation of the pulley linearly moves the cable. The movement of the cable is transmitted to a displacement detector installed at a position distant from the pulley to give a displacement to the displacement detector, whereby the angle is detected. Damage can be reliably avoided by selecting the installation position of the displacement detector so that it does not collide with earth and sand or rocks.

[0008]

The present invention will be described below with reference to the illustrated embodiments. 1 is a side view of an angle detection mechanism for a bucket of a hydraulic excavator according to an embodiment of the present invention. In this figure, 1 is an arm, 2 is a bucket, 3 is a pin that rotatably connects the arm 1 and the bucket 2, 4 is a bucket cylinder that drives the bucket 2, and 4r is a rod of the bucket cylinder 4. Reference numerals 5 and 6 are drive links for driving the bucket 2 by the bucket cylinder 4. The drive link 5 is connected to the arm 1 and the rod 4r by pins 7 and 8, respectively, and the drive link 6 is connected to the rod 4r and the bucket. 2 and pins 8 and 9 respectively. 10 shows a pulley structure. This pulley structure will be described later. Reference numeral 12 is a bracket fixed to the arm 1 to prevent the pulley structure 10 from rotating, and 13 is an outer casing. The outer casing 13 is for guiding the pull cable 11 described later. Reference numeral 14 denotes a bucket angle detector to which the pull cable 11 is connected. This bucket angle detector will also be described later.

FIG. 2 is a sectional view of the pulley structure 10 shown in FIG. In this figure, the same parts as those shown in FIG. 1 are designated by the same reference numerals. Reference numeral 11 denotes a pull cable connecting between the pulley structure 10 and the bucket angle detector 14.
101 is a first casing, 102 is a second casing, 103 is a pulley whose peripheral edge is covered with the first casing 101 and the second casing 102, and 104 is a pulley 1.
03 is a cable groove formed on the peripheral edge of 03. The pull cable 11 is pressed along the cable groove 104,
Moreover, one end thereof is fixed. Reference numeral 106 is a lead-out portion for leading the pull cable 11 to the outside. 107 is a bolt for fixing the first casing 101 and the second casing 102, S is a pulley 103 and the first casing 101
A seal mounted between the second casing 102 and the second casing 102, and B is a bolt connecting the drive link 5 and the pulley 103.

FIG. 3 is a sectional view taken along line III-III shown in FIG. In this figure, the same parts as those shown in FIG. 2 are designated by the same reference numerals. As is apparent from FIG. 2, the pulley 103 is fixed to the driving link 5 and the pin 7
Since it is rotatably attached to, it rotates integrally with the link 5.

FIG. 4 is a side view of the pulley structure shown in FIG. In this figure, the same parts as those shown in FIGS. 1, 2 and 3 are designated by the same reference numerals. 102a is a protrusion formed on a part of the casing 102. The bracket 12 fixed to the arm 1 has arms 12a and 12b whose ends are bifurcated as shown in the drawing, and the protrusion 102a is fitted between the arms 12a and 12b. By this fitting, the casing 102 and the casing 101 (the casing 102
And is fixed by bolts 107)
Locked against rotation. By this locking, the lead-out portion 106 of the pull cable 11 fitted by the casings 101 and 102 is prevented from rotating with respect to the arm 1, and the later-described operation of the pull cable 11 is guaranteed.

The structure of the bucket angle detector 14 will be described below. FIG. 5 is a schematic configuration diagram of a first specific example of the bucket angle detector shown in FIG. 11, 13, 14
Is a pull cable, an outer casing, and a bucket angle detector which are the same as those shown in FIG. 1, respectively. Reference numeral 140 is a detector casing, and 141 is a linear drive type displacement detector fixed to the detector casing 140. Reference numeral 141a denotes a displacement transmission means fixed to the pull cable 11, which engages with the displacement detection unit 141 and transmits the displacement amount (movement amount) of the pull cable 11 to this. 141S is a spring, one end of which is fixed to the detector casing 140 and the other end of which is fixed to the end of the pull cable 11. The spring 141S applies tension over the entire length of the pull cable 11 and eliminates the slack of the pull cable 11. For the linear drive type displacement detection unit 141, various types of known detection mechanisms, for example, potentiometers are used.

FIG. 6 is a schematic configuration diagram of a second specific example of the bucket angle detector shown in FIG. In this figure, the same or equivalent parts as those shown in FIG. 5 are designated by the same reference numerals. Reference numeral 142 denotes a detection pulley rotatably mounted on the detector casing 140, and 142S denotes its rotation center.
Reference numeral 143 denotes a spring, one end of which is fixed to the detector casing 140 and the other end of which is fixed to the detection pulley 142 at a position indicated by a point P ₁ . Reference numeral 144 denotes a rotational drive type displacement detecting section, and 145 denotes a displacement transmitting means for transmitting the rotation of the detection pulley 142 to the displacement detecting section 144. A well-known detection mechanism such as a potentiometer is used for the displacement detection unit 144, similar to the displacement detection unit 141 described above.

In the case of this example, the pull cable 11 is stretched over a groove (not shown) of the detection pulley 142 for about half a circumference, and its end portion is connected to the detection pulley 142 at a position indicated by a point P _2. It is fixed. The spring 143 applies tension over the entire length of the pull cable 11 via the detection pulley 142 and eliminates slack.

FIG. 7 is a schematic configuration diagram of a third specific example of the bucket angle detector shown in FIG. In this figure, the same parts as those shown in FIG. 5 are designated by the same reference numerals. Reference numeral 146 denotes a displacement transmitting means, one end of which is connected to the pull cable 11 by a connecting portion 147, and is rotatably mounted on the detector casing 140 at a rotation center 146S. Reference numeral 148 indicates a spring. One end of the spring 148 has a detector casing 14
It is fixed at 0 and the other end is connected to the end of the pull cable 11. The function of the spring 148 is the spring 14 of the first specific example.
It has the same function as 1S.

FIG. 8 shows the bucket angle detector 14 shown in FIG.
It is a figure which shows an example of the installation position of. In this figure, the same parts as those shown in FIG. Reference numeral 15 denotes a pin that rotatably connects the arm 1 and a boom (not shown). Reference numeral 16 is a lead wire that outputs an electric signal proportional to the angle detected by the bucket angle detector 14, and 17 is a pipe line (hose) that supplies and discharges pressure oil to and from the bucket cylinder 4. As is clear from the figure,
The bucket angle detector 14 is installed at the base of the arm 1. This portion is a position sufficiently distant from the bucket 2 and is a position considerably higher than the excavation position even when the bucket 2 is excavated, so that sediment or rock hardly collides with it.

Next, the operation of this embodiment will be described. When the bucket cylinder 4 is driven, the bucket 2 rotates with respect to the arm 1. At this time, the drive link 5 also rotates around the pin 7, and the pulley 103 fixed to the drive link 5 also rotates by the same amount. The pull cable 11 is pulled (or pushed out) by the rotation of the pulley 103.
To move. As described above, since the pull cable 11 is always given tension by the springs 141S (143, 148) and has no slack, the above-described movement of the pull cable 11 remains as it is for the displacement transmitting means 141a (or the detection pulley 142, It is given to the displacement transmitting means 146) to displace (or rotate) this by an amount equal to the amount of movement of the pull cable 11. This displacement (rotation) is detected by the displacement detector 141 (1
44), and the detected value of the displacement detector 141 (144) is output to the arithmetic unit via the lead wire 16 as an electric signal, and the angle corresponding to the electric signal is obtained.

As described above, in this embodiment, the pulley is provided at the position for detecting the angle, the bucket angle detector is installed at a position sufficiently distant from the pulley, and tension is applied to the pulley and the bucket angle detector. By connecting with a pull cable, the same amount of movement as the pull cable is transmitted to the bucket angle detector, so damage to the bucket angle detector due to collision of earth and sand or rocks does not impair detection accuracy. Can be prevented. Further, since the exposed portion of the pulley is protected by the casing, the arm and the drive link, there is no risk of damage due to collision of earth and sand or rocks.

FIG. 9 is a side view of a bucket angle detecting mechanism of a hydraulic excavator according to another embodiment of the present invention. In this figure, parts that are the same as or equivalent to the parts shown in FIG. The present embodiment differs from the previous embodiment in that the previous embodiment uses one pull cable 11, whereas in the present embodiment, two pull cables 1 are used.
1a and 11b are used, and the configuration of the bucket angle detector 14 is different, and the other configurations are the same. The pull cables 11a and 11b are protected by outer casings 13a and 13b, respectively, and guided to the bucket angle detector 14.

FIG. 10 shows the two pull cables 1 shown in FIG.
It is a schematic block diagram of the bucket angle detector 14 when using 1a, 11b. In this figure, the same parts as those shown in FIG. 6 are designated by the same reference numerals. Each pull cable 11a,
11b are fixed to appropriate positions of grooves (not shown) formed in the peripheral edge of the detection pulley 142, respectively.

The operation of this embodiment is similar to that of the previous embodiment. That is, when the drive link 5 rotates, the pulley 103
Rotates, the pull cables 11a and 11b move in opposite directions and by the same amount, and the pulley 142 of the bucket angle detector 14 is rotated to rotate the pull cables 11a and 11b.
The movement amounts of a and 11b are detected. However, in the case of this embodiment, since the two pull cables 11a and 11b are used, the springs 141S, 143, and 148 in the bucket angle detector 14 of the previous embodiment are unnecessary. The effect of this embodiment is the same as that of the previous embodiment.

In the above description of the embodiments, the pull cables 11, 11a and 11b are used, but it is obvious that a known push-pull cable can be used instead. In this case, as in the other embodiments described above, a spring for applying tension to the cable is not necessary.

Also, an example in which the pulley 103 is attached to the pin 7 has been described. The pulley 103 can be mounted on any of the pins 3, 7, 8 and 9.
It will be attached to any pin in consideration of various conditions. The attachment to each of these pins has the following characteristics or problems. That is, the attachment to the pin 3 has an advantage that the bucket angle can be directly detected, but when the pulley structure 10 is larger than the boss diameter, the contact with an attachment such as a bucket becomes a problem. The attachment to the pin 7 as in this embodiment does not require any consideration for the attachment, but the angle conversion is required to obtain the bucket angle. Attaching to pins 8 and 9 is arm 1
Since it moves with respect to the pull cable, it is difficult to route the pull cable, and it is necessary to convert the angle.

By the way, in each of the above-mentioned embodiments, the cable 6 or the pull cables 11a, 11b are protected by being covered with the outer casings 13, 13a, 13b. However, at the actual work site, since fragments of earth and sand and rocks are scattered, the cables 6, 11 are used in the outer casings 13, 13a, 13b.
The protection of a and 11b may not be sufficient. A structure for ensuring the protection of the cables 6, 11a, 11b in such a case will be described with reference to FIGS. 11 to 13 below.

FIG. 11 is a view showing the installation position of the bucket angle detector as in FIG. 8, and FIG. 12 is a line XII- shown in FIG.
It is sectional drawing which follows XII. In these figures, the same or equivalent parts as those shown in FIG. 8 are designated by the same reference numerals.
1U is the upper surface of the arm 1, 20 is a seat screw, 21
Is a protective cover, 22 is a holding plate, and 23 is a bolt, which are shown in more detail in FIG. That is, a plurality of seat screws 20 are welded to appropriate portions of the arm 1, while the protective cover 22 is arranged on the arm 1 in a state of covering the externally exposed portion of the outer casing 13. The pressing plate 22 is fixed to the seat screw 20 with bolts 23, and by pressing the upper surface of the protective cover 21 with the pressing plate 22, the protective cover 21 is moved to the arm 1.
It is fixed in contact with.

FIG. 13 shows a case where the outer casing 13 (cables 6, 11a, 11b) is arranged along the upper surface 1U of the arm 1, and the same or equivalent parts as those shown in FIG. Is attached. The fixing of the protective cover 21 in the case shown in FIG. 13 is also performed by the holding plate 22 fixed to the seat screw 20 with the bolt 23, as in the case shown in FIG.

As described above, in the embodiment shown in FIGS. 11, 12 and 13, since the outer cover 13 is covered with the protective cover 21, the cables 6, 11a and 11b can be surely protected, and the bucket angle. Guarantee the angle detection by the detector. Further, when the strength of the protective cover 21 is sufficient and the pull cable is used as the cable, only the protective cover 21 can be used and the outer casing 13 can be omitted.

Although the respective embodiments of the present invention have been described above, in the description of these embodiments, the bucket angle detecting mechanism of the hydraulic excavator has been described. However, it is obvious that the present invention is not limited to the bucket angle detection mechanism of the hydraulic excavator, but can be applied to the angle detection of other links of the hydraulic excavator or the angle detection of other various working machines.

[0029]

As described above, according to the present invention, the pulley that rotates with the rotation of the link is provided, and the displacement detector that detects the angle is installed at an arbitrary position on the working machine apart from the pulley. Since the rotation of the pulley is transmitted to the displacement detector by a cable fixed to the pulley, the displacement detector can be reliably prevented from being damaged.

[Brief description of drawings]

FIG. 1 is a side view of an angle detection mechanism for a bucket of a hydraulic excavator according to an embodiment of the present invention.

FIG. 2 is a sectional view of the pulley structure shown in FIG.

FIG. 3 is a sectional view taken along line III-III shown in FIG.

FIG. 4 is a side view of the pulley structure shown in FIG.

5 is a schematic configuration diagram of a first specific example of the bucket angle detector shown in FIG. 1. FIG.

FIG. 6 is a schematic configuration diagram of a second specific example of the bucket angle detector shown in FIG.

FIG. 7 is a schematic configuration diagram of a third specific example of the bucket angle detector shown in FIG.

FIG. 8 is a diagram illustrating the installation position of a bucket angle detector.

FIG. 9 is a side view of an angle detection mechanism for a bucket of a hydraulic excavator according to another embodiment of the present invention.

10 is a schematic configuration diagram of the bucket angle detector shown in FIG.

FIG. 11 is a diagram illustrating the arrangement of cables.

12 is a cross-sectional view taken along the line XII-XII shown in FIG.

FIG. 13 is a cross-sectional view of a protective cover for another arrangement example of cables.

[Explanation of symbols]

 1 Arm 2 Bucket 4 Bucket Cylinder 7 Pin 10 Pulley Structure 11 Pull Cable 12 Bracket 13 Outer Casing 14 Bucket Angle Detector

Claims (10)

[Claims] 1. A working machine provided with a plurality of links constituting a working unit, wherein the pulley rotates with the rotation of the link and a displacement installed at an arbitrary position on the working machine away from the pulley. An angle detection mechanism for a working machine, comprising: a detector; and a cable fixed to the pulley and transmitting a rotation of the pulley to the displacement detector. 2. The angle detection mechanism for a working machine according to claim 1, wherein the pulley is fixed to the link, and a rotary shaft of the link is a rotary shaft. 3. The angle detection of a working machine according to claim 1, wherein the pulley is fixed to a drive link for driving the link, and a rotation shaft of the drive link is used as a rotation shaft. mechanism. 4. The angle detection mechanism for a working machine according to claim 1, wherein the pulley is arranged between two links that are objects of angle detection. 5. The angle detection mechanism for a working machine according to claim 1, wherein the pulley is housed in a casing. 6. The displacement detector according to claim 1,
An angle detection mechanism for a working machine, which is composed of a displacement gauge for detecting movement of the cable. 7. The displacement detector according to claim 1,
A work characterized by comprising an angle detection unit having a rotation shaft connected to another and detecting a rotation angle of the rotation shaft, and a detection pulley transmitting the movement of the cable to the rotation shaft. Machine angle detection mechanism. 8. The displacement detector according to claim 1, wherein the displacement detector has an axis of rotation connected to another, and an angle detector for detecting a rotation angle of the axis of rotation, and the cable and the axis of rotation are connected. An angle detection mechanism for a working machine, which is configured with a lever. 9. The cable according to claim 1, wherein the cable is
An angle detection mechanism for a working machine, characterized in that a portion exposed to the outside is covered with a protective cover. 10. The angle detection mechanism for a working machine according to claim 9, wherein the protective cover is detachably attached to a structure in which the cable is arranged.