JPH08253954A - Device to detect angle of bucket of power shovel - Google Patents

Abstract

PURPOSE: To reduce size by a method wherein rotational movement of a bucket is transmitted to the first pulley of the tip of an arm and changed to linear movement of a pull cable and converted into rotational movement of a second pulley, and the angle of a bucket is determined from an electric amount. CONSTITUTION: A first pulley 5 is rotated coaxially with one end of the second part 4b of a link 4 and integrally with the link 4 and rotatably contained in a first case 15. In this case, a second case 7 comprises a body and a cover and a second pulley is rotatably in a body. Further, a spiral spring having one end fixed to the second pulley and the other end fixed to the body is disposed on the rotary shaft of the second pulley. Further, a protrusion is formed on the bottom of the bearing part of the second case 7 and a protrusion part in a partial annular shape in cross section is formed on the tip of the rotary shaft of the second pulley. Through cooperation of the protrusion and the protrusion part with each other, rotation of the second pulley is regulated and the protrusion and the protrusion part are served as the angle reference of a potentiometer 9 to detect a movement amount.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting the angle of a bucket of a power shovel having excellent vibration resistance. More specifically, the rotational movement of the bucket is transmitted to a first pulley provided at the tip of the arm via a link, and this rotation is transmitted between the first pulley and the first pulley provided at the base of the arm. After converting to the linear movement of the pull cable routed in the middle,
The present invention relates to a device for converting a rotary motion of a pulley and converting the rotary motion into an electric quantity by a potentiometer to calculate an angle of a bucket of a power shovel.

[0002]

As an apparatus for detecting the angle of a bucket of a power shovel, Japanese Utility Model Laid-Open No. 1-176164 discloses
The conduit 28a is arranged along the longitudinal direction of the arm 23, and the inner cord 28 slidably inserted into the conduit 28a.
a push-pull wire 28 having one end of the inner cable 28b fixed to the link 32, and the other end of the inner cable 28b connected to the detection end d of the push sensor 28, and a stroke sensor 29 fixed to the main body. A device constructed is disclosed (see FIG. 3 (a)). The link 32 is used for the arm 2
3 and a bucket 25 rotatably attached to the arm
Is inserted between the bucket 25 and one end.
A first portion swingably attached to the first portion, and one end of the second portion swingably connected to the first portion and the other end swingably connected to the tip of the arm 23. It is composed of parts and. A tip end of a piston 26a, which is telescopically inserted into the bucket cylinder 26 and is inserted / removed by hydraulic control, is swingably connected to a connecting portion between the first portion and the second portion.

In the case of this apparatus, the piston 26a that is telescopically inserted into and out of the bucket cylinder 26 is moved in and out by the hydraulic control, and the angle θ of the bucket 25 with respect to the arm 23 is changed. Meanwhile, inner line 28
Since b is fixed at the position a in the link 32 as described above, the change in the angle θ causes the conduit 2
The distance D from one end b of 8a to the tip of the inner cable 28b changes. When the distance D further changes, the distance S between the other end c of the conduit 28a and the position d where the detection end of the stroke sensor 29 is connected to the inner cable 28b changes. The relative angle of the bucket 25 with respect to the arm 23 is calculated by converting the displacement (FIG. 3).
(B)). Further, in another conventional device, the sensor body is directly attached to the bucket rotating shaft portion.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the case of the conventional device disclosed in Japanese Patent No. 164, since the rotary motion of the bucket is converted into the linear motion of the inner rope, an error is inevitably generated. Further, since the push-pull cable is used, there are problems that the connection portion cannot be protected, the bending durability is low, and stroke loss due to bending occurs.

In the case of another conventional apparatus, since the sensor body is attached to the arm, vibrations of the prime mover during the operation of the power shovel, shocks during excavation by the bucket, etc. are transmitted to the arm and the detection end of the sensor is transmitted. There is a problem that it is difficult to accurately measure the amount of movement of the inner cord because of the blurring of the eyelid. For this reason, it is necessary to increase the vibration resistance of the sensor itself, or to increase the vibration resistance of the sensor by interposing a shock absorber between the arm and the sensor body. Raises the problem of higher costs.

An object of the present invention is to provide a device for detecting the bucket angle of a power shovel, which has a relatively small number of parts and is highly vibration resistant.

[0007]

A device for detecting an angle of a bucket of a power shovel according to the present invention (hereinafter, referred to as a device) includes a bucket, an arm, a boom, and the like, which are swingably connected to each other. In a work arm of a power shovel, the one end of which is rotatably connected to the bucket and the other end of which can rotate integrally with a link provided on a first shaft provided at substantially the tip of the arm. 1
The pulley and the first end of the arm are fixed to the first
A first case for rotatably accommodating a pulley, a second pulley rotatably provided at the base of the arm, and means fixed to the base of the arm for restricting rotation of the second pulley are formed. A second case, one end of which is wound around the first pulley, the other end of which is wound around the second pulley, and one end of which is attached to the first case and the other end of which is the first A pull cable that is attached to two cases and that is configured to include a conduit that slidably guides the inner cord, and that is provided coaxially with the second pulley to adjust the amount of movement of the inner cord in the longitudinal direction. It is characterized by comprising means for detecting.

The means for detecting the amount of movement of the inner cable in the longitudinal direction is coaxially arranged with respect to the second pulley so that its rotation shaft can rotate integrally with the second pulley, The main body is fixed to the arm via a second case that pivotally supports the second pulley, and means for urging the second pulley so as to rotate in a direction in which the inner cable is drawn into the second case is provided. Is preferred.

The means for restricting the rotation of the second pulley is a surface contacting the tip of the rotating shaft of the second pulley in the bearing portion that supports the second pulley formed on the bottom of the second case. The protrusion formed on the second
It is preferable that the means for detecting the amount of movement, which is formed at the tip end portion of the pulley and that engages with the protrusion, is a mounting angle adjusting type.

Means for urging the second pulley so as to rotate in the direction in which the inner cable is pulled from the second case has one end fixed to the second case and the other end fixed to the second pulley. It is preferably a spiral spring.

The means for detecting the amount of movement of the inner cable in the longitudinal direction is preferably a potentiometer.

[0012]

In the device of the present invention constructed as above, the rotation of the bucket is directly transmitted to the rotation of the first pulley, and the rotation of the pull cable is wound around the rotation of the first pulley. The other end of the pull cable is transmitted to the second pulley through which the rotation is transmitted, and this rotation is transmitted to the potentiometer coaxially arranged with respect to the second pulley to detect the rotation amount. That is, since the rotation of the bucket is directly transmitted to the potentiometer, the accuracy of measurement is relatively high.

Further, in the case of the device of the present invention, since the sensor is attached to the arm via the second case in which the second pulley is rotatably accommodated, the axial vibration of the second pulley is to some extent. Can be absorbed. Furthermore, since the movement of the inner cable is wound around the pulleys at both ends and converted into the rotational movement by using the pull cable, the construction can be made compact.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 and 2, an apparatus 20 for detecting bucket angle of a power shovel according to the present invention.
(Hereafter, referred to as a device) will be described.

The device 20 of the present invention is arranged on the working arm of a power shovel which is swingably connected to each other such as the bucket 1, the arm 2 and the boom 3.

The device 20 has one end rotatably connected to the bucket 1 and the other end having a link 4 provided on a first shaft 2a provided substantially at the tip of the arm 2 and the first shaft 2a. A first pulley 5 that is rotatably attached to the first pulley 5 that can rotate integrally with the link 4, and a first case 15 that is fixed to the tip of the arm 2 and that rotatably accommodates the first pulley 5. And a second pulley 6 rotatably provided at the base of the arm 2, and a second case 7 fixed to the base of the arm 2 and having means for restricting rotation of the second pulley 6. An inner cable 8b having one end wound around the first pulley 5 and the other end wound around the second pulley 6, and one end attached to the first case 15 and the other end connected to the second The inner cable 8b attached to the case 7 slides on itself. A pull cable 8 including a conduit 8a that guides the inner cable 8a and a means 9 that is provided coaxially with the second pulley 6 and that detects the amount of movement of the inner cable 8b in the longitudinal direction. It

The link 4 is composed of a first portion 4a whose one end is rotatably connected to the bucket 1 and a second portion 4b whose one end is rotatably connected to the tip of the arm 2. The first portion 4a and the second portion 4b are connected to each other by the connecting portion 4
It is swingably connected to each other at c.

One end of a piston 10b which is telescopically inserted in the cylinder 10a is connected to the connecting portion 4c. The piston 10b is operated by a hydraulic pump (not shown) or the like.

In this embodiment, the first pulley 5 is one end of the second portion 4b of the link 4 (that is, the first shaft 2a).
It is mounted coaxially with the link 4 so as to rotate integrally therewith, and is rotatably accommodated in the first case 15.

As shown in FIG. 2, the second case 7 comprises a main body 7b and a lid 7a. The second pulley 6 has a main body 7
It is rotatably accommodated in b.

The body 9a of the means 9 for detecting the amount of movement of the inner cable 8b in the longitudinal direction is fixed to the lid 7a. The rotating shaft 9b that functions as a detecting unit is arranged so as to be coaxial with the rotating shaft 14 of the second pulley 6, and the second pulley 6
Rotates integrally with. In the case of the present embodiment, a mounting angle adjusting potentiometer is preferably used as the means 9 for detecting the amount of movement of the inner cable 8b in the longitudinal direction.

In this embodiment, the spiral spring 11 has one end fixed to the second pulley 6 and the other end fixed to the main body 7b.
Is provided on the rotating shaft of the second pulley 6. As a result, the second pulley 6 is biased so as to rotate in the direction in which the inner cable 8b is pulled into the second case 7.

Further, a protrusion 13 is formed on the bottom of the bearing 12 of the second case 7, and a protrusion 14a having a partially annular cross section is formed at the tip of the rotary shaft 14 of the second pulley 6. Has been formed. The protrusion 13 and the protrusion 14a
By co-operating with and, the rotation of the second pulley 6 is regulated and it serves as an angle reference of the means 9 for detecting the movement amount.

[0024]

In the case of the device of the present invention, the rotation of the bucket is directly transmitted to the first pulley via the link, and the first pulley is rotated.
Since it is transmitted to the second pulley and further transmitted to the second pulley via the inner cable wound around the pulley, the rotation of the second pulley is detected by the potentiometer,
The error is extremely small.

Furthermore, since the pull cable itself has a high vibration transmissibility and the sensor body is attached to the arm via the second case, the vibration of the power shovel prime mover transmitted to the arm and the shock during excavation work are absorbed to some extent. Therefore, it is not necessary to increase the vibration resistance of the sensor itself.
Furthermore, since the movement of the inner cable is wound around the pulleys at both ends and converted into the rotational movement by using the pull cable, the structure can be made compact.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a state in which a device for detecting an angle of a bucket of a power shovel of the present invention is installed.

FIG. 2 is a side view showing a configuration of a second pulley in the device of FIG.

FIG. 3 is an explanatory diagram showing a state in which a conventional device is installed in a power shovel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bucket 2 Arm 4 Link 4c Connection part 5 1st pulley 6 2nd pulley 7 2nd case 8 Pull cable 8a Conduit 8b Inner rope 9 Device for detecting the amount of movement 12 Protrusion 14a Projection 15 1st case 20 Device

Claims (5)

[Claims] 1. A work arm of a power shovel in which constituent members such as a bucket, an arm, and a boom are swingably connected to each other, one end of which is rotatably connected to the bucket and the other end of which is the arm. A first pulley capable of rotating integrally with a link provided on a first shaft provided substantially at the tip of the arm, and a first case fixed to the tip of the arm and rotatably accommodating the first pulley. , A second pulley rotatably provided at the base of the arm, a second case fixed to the base of the arm and configured to restrict rotation of the second pulley, and one end of the second case An inner cord wound around a first pulley and the other end thereof wound around the second pulley, and an inner cord having one end attached to the first case and the other end attached to the second case. Slidably Detects the angle of the bucket of the power shovel, which is provided coaxially with the second pulley and is configured to detect the amount of movement of the inner cable in the longitudinal direction, and the pull cable includes a guiding conduit. Device for doing. 2. The means for detecting the amount of movement of the inner cable in the longitudinal direction is coaxially arranged with respect to the second pulley so that its rotation axis can rotate integrally with the second pulley. The main body is fixed to the arm via a second case that pivotally supports the second pulley, and means for urging the second pulley to rotate in the direction of pulling the inner rope into the second case is provided. The apparatus of claim 1, wherein the apparatus comprises. 3. A bearing for axially supporting the second pulley formed on the bottom of the second case, wherein the means for restricting the rotation of the second pulley has a tip end portion of the rotary shaft of the second pulley. A means for detecting the amount of movement is a mounting angle adjusting type, which is composed of a protrusion formed on a surface in contact with the protrusion and a protrusion formed on the tip of the second pulley and engaging with the protrusion. An apparatus according to claim 1 or 2, characterized in that it is present. 4. A means for urging the second pulley so as to rotate in a direction in which the inner cable is drawn into the second case has one end fixed to the second case and the other end attached to the second pulley. The device of claim 2 which is a fixed spiral spring. 5. The device according to claim 1, wherein the means for detecting the amount of movement of the inner cable in the longitudinal direction is a potentiometer.