JPH1037254A - Loading weight measuring device in working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple and easy measuring device which measures accurately a loading weight without reducing the operability of the machine. SOLUTION: The stick 15 of the front working structure of a hydraulic shovel and the bucket 16 are rotatably connected to each other by a pin 19. And a strap 31 and a rod 32 of the bucket linkage member to control the bucket angle are rotatably connected through pins 34, 33, 35, between the stick 15 and the bucket 16. The first load detector 41 is installed to measure the load in only the N-N axial direction in the pin 19 connecting the stick 15 and the bucket 16 and the second load detector 44 is installed to measure the load in only the M-M axial direction in the pin 35 connecting the bucket 16 and the rod 32. The angles of the N-N axial direction and the M-M axial direction are detected by an inclination detector detecting an angle of the bucket 16 against the ground.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load weight measuring device for a working machine applicable to a hydraulic excavator, a backhoe, a loader and the like.

[0002]

2. Description of the Related Art In a conventional excavator, for example, when excavating and loading sediment and the like into a bucket on a dump truck, the weight of the sediment and the like is measured in a state where the sediment and the like have entered the bucket. There was no way to do it.

[0003] Therefore, in the conventional loading operation, the weight of earth and sand loaded on a dump truck or the like is estimated by an operator's intuition, or after loading on a dump truck or the like, a large vehicle loading capacity measuring device is used. Either the load weight of each truck is measured, or the soil and the like are temporarily transferred to a separately installed weight measuring device to measure the weight, and then the work is loaded again on the dump truck or the like.

[0004]

In the estimation of the loading weight based on the intuition of the operator, an accurate loading weight cannot be grasped. In addition, in a large vehicle loading amount measuring device or a weight measuring device, it is difficult to install the device. It takes time, place, cost, and the like, and furthermore, when earth and sand are loaded on a dump truck or the like via a weight measuring device, the work is troublesome twice and has a problem that the working efficiency is poor.

The present invention has been made in view of the above points, and has as its object to provide a simple load weight measuring device capable of accurately measuring a loaded weight without impairing workability of a work machine. It is.

[0006]

According to a first aspect of the present invention, there is provided a work machine for operating a bucket by a work mechanism, the load being configured to measure a load based on the weight of a measurement object in the bucket provided in the work mechanism. It is a load weight measuring device provided with a detector.

[0007] Then, by the load detector in the working mechanism,
The load due to the weight of the object to be measured in the bucket taken into the bucket is measured simultaneously with the loading operation.

According to a second aspect of the present invention, in a work machine for operating a bucket by a work mechanism, a load detector provided in the work mechanism for measuring a load due to the weight of an object to be measured in the bucket; The load weight measuring device includes a tilt angle detector that detects a fixed bucket posture suitable for measuring a load based on the weight of a measurement target.

Then, a fixed bucket posture suitable for measuring the load due to the weight of the object to be measured in the bucket is detected by the inclination angle detector, and in the bucket posture, the object to be measured in the bucket is detected by the load detector in the working mechanism. Measure the weight load.

According to a third aspect of the present invention, in the load weight measuring device for a working machine according to the first or second aspect, the load detector includes a load applied to a tip portion of an arm member supporting the bucket by the working mechanism. And a second load detector for measuring the load applied to the tip of the bucket linkage member for controlling the bucket angle by the working mechanism.

The load applied to the tip of the arm member supporting the bucket is measured by the first load detector, and the load applied to the tip of the bucket linkage member for controlling the bucket angle is determined by the second load detector. By measuring, the weight of the measurement object in the bucket taken into the bucket is measured from these measured values.

According to a fourth aspect of the present invention, a lower traveling structure, an upper revolving structure, and a boom, a stick, and a bucket connected to the upper revolving structure by a pin so as to be sequentially rotatable, and a space between the stick and the bucket. A work machine having a front working mechanism in which a bucket linkage member for controlling a bucket angle is rotatably connected by a pin, the work machine being mounted on a pin connecting the stick and the bucket to measure a load only in a specific direction. A load detector, a tilt angle detector that detects a specific direction for load measurement by detecting a ground angle of the bucket, and a tilt angle detector that is installed on a pin connecting the bucket and the bucket linkage member and is detected. The second to measure the load only in a specific direction
And a load detector for a work machine including the load detector.

When the object to be measured in the bucket, such as earth and sand, is taken into the bucket, the first load detector installed on the pin connecting the stick and the bucket is connected to the bucket and the bucket linkage member. The load due to the weight of the object to be measured in the bucket and the weight of the bucket acts in opposite directions to the second load detector installed on the pin. For this reason, when the state in which the first and second load detectors are located in the specific direction suitable for measurement is detected by the inclination angle detector, the second load detector detects the second load from the load detected by the first load detector. By subtracting the load detected by the detector from the weight of the bucket, the net weight of the object to be measured in the bucket can be obtained.

According to a fifth aspect of the present invention, in the load weight measuring device for a working machine according to the fourth aspect, a load detector and an inclination angle detector are provided inside the pin. Then, the load detector and the tilt angle detector are handled integrally with the pin.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 5, a hydraulic excavator as a working machine has a lower traveling body 11, an upper swing body 12, and a front working mechanism 13.

The front working mechanism 13 connects the boom 14, the stick 15, and the bucket 16 to the upper revolving unit 12 with pins 17, 18,
19, and a boom rotation cylinder 21, a stick rotation cylinder 22, and a bucket rotation cylinder 23 are rotatably connected by pins 24, 25, 26, 27, 28, respectively. Tip of piston rod 29 of cylinder 23, stick 15 and bucket
16 and a strap 31 and a rod 32 serving as bucket linkage members for controlling the bucket angle.
It is connected rotatably by 4, 35.

The boom 14, the stick 15, and the bucket 16 are rotated by extending and retracting the piston rods of the boom rotation cylinder 21, the stick rotation cylinder 22, and the bucket rotation cylinder 23.

As shown in FIGS. 2A and 2B, the pin 19 comprises a stick 15 as an arm member for supporting the bucket 16 and a bracket 16a integrally attached to the back side of the bucket 16. Is a bucket pin that connects. Since through holes 36 and 37 are formed in the bucket pin 19 and the pin fitting boss 16b formed integrally with the bracket 16a of the bucket 16, a bolt 38 is inserted into these through holes 36 and 37. Then, by screwing a nut 39 to the bolt 38, the bucket pin 19 is attached to the bracket 16 a of the bucket 16.
Fixed to

As shown in FIGS. 2A and 2B, the pin 35 is a linkage pin for connecting the bracket 16a of the bucket 16 and the rod 32 which is one of the bucket linkage members. This linkage pin 35 is, similarly to the bucket pin 19, a bolt inserted into the through holes 36 and 37.
38 and nut 39, the bracket 16a of the bucket 16
Fixed to

In short, the bucket pin 19 and the linkage pin 35 are mounted integrally with the bucket 16, and the rotation angle of the bucket 16 is the rotation angle of the bucket pin 19 and the linkage pin 35.

As shown in FIGS. 1 and 3, a load applied to the tip of the stick 15 in the NN axis direction is provided inside the bucket pin 19 connecting the stick 15 and the bracket 16a of the bucket 16. Load detector for measuring the load
Install 41.

That is, as shown in FIGS. 3A and 3B, a square section 19a having a square cross section is formed at a position slightly inside the end face of the bucket pin 19 in the axial direction.
a, mounting holes 42 are drilled from one side and the opposite side, a central wall 42a is provided between the counterbore bottoms of these mounting holes 42, and a pair of strain gauges are provided on the counterbore bottoms on both sides of the central wall 42a. A first load detector 41 configured by sticking or the like is provided.

As shown in FIG. 3A, the load detector 41 on one side is provided at an angle of 45 ° clockwise with respect to the vertical, and the load detector 41 on the other side is positioned at an angle with respect to the vertical. It is preferable to provide at an angle of 45 ° counterclockwise.

Further, as shown in FIGS. 3A and 3C, an inclination angle detector 43 for detecting the angle of the bucket 16 to the ground is provided inside the bucket pin 19. As the tilt angle detector 43, for example, a general type such as a pendulum type or a strain type is used. As shown in FIG. 3D, the tilt angle detector 43 detects the load measurement N- in a specific direction (the vertical direction, that is, the direction of gravitational acceleration g is a specific direction).
The angle θ of the N axis is detected.

As shown in FIGS. 1 and 4,
Inside the linkage pin 35 connecting the bracket 16a of the bucket 16 and the rod 32, the load applied to the distal end of the rod 32 is parallel to the NN axis direction detected by the inclination angle detector 43, that is, in the same direction. A second load detector 44 for measuring a load component in a certain MM axis direction is installed.

That is, as shown in FIG. 4, the linkage pin 35 is also provided with a square section 35a having a square cross section, a mounting hole 45 and a central wall section 45a similarly to the bucket pin 19, and both sides of the central wall section 45a. There is provided a second load detector 44 configured by attaching a pair of strain gauges to the bottom surface of the counterbore.

As described above, since the bucket pin 19 and the linkage pin 35 are integrated with the bucket 16 by bolting and do not rotate with respect to the bucket 16, as shown in FIG. The axis and the MM axis of the linkage pin 35 are fixed to the bucket 16 so that they are parallel to each other and perpendicular to the S-plane of the bucket 16.

As shown in FIG. 2B, mounting holes 42 and 45 for the bucket pin 19 and the linkage pin 35 are provided.
Is located between the stick 15 or the rod 32 and the bracket 16a of the bucket 16, so that the load detector 4 is located at the position in the pin axis direction where the load applied to the bucket 16 is most easily detected.
1,44 can be provided.

Next, the operation of the illustrated embodiment will be described.

When an object to be measured such as earth and sand is taken into the bucket 16, the load due to the weight of the object to be measured in the bucket is measured by the first load detector 41 and the second load detector 44. The most suitable bucket posture is detected by the inclination angle detector 43. That is, as shown in FIG. 1, a state in which the NN axis and the MM axis coincide with a specific direction (vertical direction, that is, the direction of gravitational acceleration) is detected.

Then, in the optimum bucket posture shown in FIG. 1, the values detected by the first load detector 41 and the second load detector 44 are calculated by the arithmetic unit of the microcomputer mounted on the hydraulic shovel. The load due to the weight of the object to be measured in the bucket is measured and calculated simultaneously with the loading operation.

That is, a stick as an arm member for supporting the bucket 16 in the bucket posture shown in FIG.
The load applied to the tip of the bucket 15 is measured by a first load detector 41 installed on a bucket pin 19 connecting the stick 15 and the bracket 16a of the bucket 16, and the tip of a bucket linkage member for controlling the bucket angle. The load on the part is controlled by the bucket linkage rod 32 and the bucket.
The measurement is performed by the second load detector 44 installed on the linkage pin 35 connecting the 16 brackets 16a. And
From the measured values of the load detectors 41 and 44, the weight of the measurement object in the bucket taken into the bucket 16 is measured.

That is, as shown in FIG. 1, the combined weight of the weight W1 of the object to be measured in the bucket and the own weight W2 of the bucket 16 is different between the first load detector 41 and the second load detector 44. , A load F2y in the MM axis direction detected by the second load detector 44 from a load F1y in the NN axis direction detected by the first load detector 41, By subtracting the weight W2 of the bucket 16, the net weight W1 of the object to be measured in the bucket can be obtained.

This weight calculation method will be specifically described with reference to FIG.

When the sediment D as a measurement object in the bucket is taken into the bucket 16, a load F1 acts on the bucket pin 19 due to the weight W1 of the sediment D and the weight W2 of the bucket 16. In addition, a reaction force load F2 acts on the linkage pin 35 by balancing the moment about the bucket pin 19 as a fulcrum. Since the first load detector 41 detects only the load in the NN axis direction only, the first load detector 41 detects the load F1y in the NN axis direction. Similarly, the second load detector 44 detects only the load in the MM axis direction. Since only the load due to the weight is detected, the load F2y in the MM axis direction is detected.

The angle detected by the inclination angle detector 43 is constantly monitored. When the bucket 16 is in a posture where the S surface of the bucket 16 is horizontal with respect to the ground plane, the NN axis and the MM axis are oriented in the vertical direction. So that the first load detector 41 and the second
The load detector 44 detects only the vertical weight load.

Therefore, the load F1y is determined by the weight W of the earth and sand D.
1, which is equal to the total of the weight W2 of the bucket 16 and the load F2y. The own weight W2 of the bucket 16 is known in advance, and the vertical reaction force load F2y is detected by the second load detector 44. Therefore, the self-weight W2 of the bucket 16 and the vertical reaction force load F2y are detected from the load F1y. Is subtracted, the weight W1 of the earth and sand D can be obtained.

Such calculations are performed by a central processing unit (hereinafter referred to as CPU) and a memory incorporated in a control device for controlling the engine and the hydraulic circuit of the hydraulic shovel.

Then, the calculated weight W1 of the earth and sand D
Is displayed on a display such as a liquid crystal display device (not shown) provided on an instrument panel or the like in the cab, as an integrated value added each time a loading operation is performed. It is possible to always know the exact weight of the earth and sand loaded on the.

The load detectors 41 and 44 and the tilt angle detector
43 is provided inside the bucket pin 19 and the linkage pin 35.
It can be easily handled as a part integral with 19 and 35, and can be effectively protected from excavated earth and sand D during work.

The load detectors 41 and 44 are provided with square portions 19a and 35a of the bucket pin 19 and the linkage pin 35 to which the load due to the weight of the earth D and the bucket 16 is concentrated.
Since it is attached to the sensor, distortion and the like can be measured with high sensitivity.

Next, another embodiment of the present invention not shown in the drawings will be described.

The present invention is not limited to a hydraulic excavator, but can be applied to other working machines such as a backhoe. In particular, the inventions described in claims 1 to 3 can be applied to a work machine that operates a bucket by another work mechanism such as a wheel loader or a crawler type loader.

According to the first to third aspects of the present invention, the installation locations of the load detectors 41 and 44 are not limited to the illustrated bucket pin 19 and the linkage pin 35.
A structure may be employed in which a strain gauge is attached to the tip of the stick 15 or the rod 32, or a piezoelectric element is sandwiched between the bucket pin 19 and the stick 15. In short, other embodiments may be used as long as the load detectors 41 and 44 are provided in the working mechanism.

The first and second aspects of the present invention do not necessarily require both the first load detector 41 and the second load detector 44. For example, the first load detector in a fixed bucket posture may be used. 41 and the second load detector 44
The relationship with the measured value is measured in advance with various loads,
If the relationship is stored as known data in a memory of a microcomputer or the like, the measured value of one of the load detectors can be used to determine the measured value of the other load detector, so that only one load detector may be used.

The invention described in claim 1 does not necessarily require the inclination angle detector 43. For example, in a working machine in which a rotation angle sensor such as a potentiometer is attached to a rotation portion of each member constituting a working mechanism. The attitude of the bucket 16 can be grasped in the same manner as the inclination angle detector 43 by the rotation angle sensors of those members. Further, a fixed bucket posture may be determined by visual observation of the operator, and the measured value by the load detector may be taken.

[0048]

According to the first aspect of the present invention, there is provided a load weight measuring apparatus having a simple structure in which a load detector for measuring a load due to the weight of an object to be measured in a bucket is provided in a work mechanism of a work machine. However, it is possible to accurately and immediately measure the weight of the object to be measured in the bucket, such as earth and sand, taken into the bucket during the loading operation, and to know the exact loading weight, thereby preventing overloading on dump trucks, etc. This makes it possible to perform management and the like, and without impairing the workability of the working machine at all, and to improve the working efficiency as compared with a case where earth and sand are loaded onto a dump truck or the like via a conventional weight measuring device.

According to the second aspect of the present invention, the weight of the object to be measured in the bucket can be accurately measured by the load detector in the working mechanism in a bucket posture suitable for measuring the load detected by the inclination angle detector. .

According to the third aspect of the present invention, the first load detector measures the load applied to the distal end of the arm member supporting the bucket, and the second load detector controls the bucket angle. By measuring the load applied to the distal end of the linkage member, the weight of the measurement object in the bucket taken into the bucket can be accurately measured from these measured values.

According to the fourth aspect of the present invention, the specific direction for measuring the load weight is detected by detecting the ground angle of the bucket by the inclination angle detector, and the pin is provided on the pin connecting the stick and the bucket. By measuring the load only in a specific direction by the first load detector and measuring the load only in the specific direction by the second load detector installed on the pin connecting the bucket and the bucket linkage member, The weight of the object to be measured in the bucket during the loading operation can be accurately measured.

According to the fifth aspect of the present invention, since the load detector and the tilt angle detector are provided inside the pin, the load detector and the tilt angle detector can be handled integrally with the pin. In addition to being easy to handle at the time of attachment and the like, the load detector and the inclination angle detector can be protected from soil or the like as a measurement object in the bucket.

[Brief description of the drawings]

FIG. 1 is a front view of an embodiment of a load weight measuring device in a work machine according to the present invention in a state where sediment is taken in;

FIG. 2A is a front view of a structural part of the measuring device in which a bucket pin and a linkage pin are integrated with a bucket side, and FIG. 2B is a side view thereof.

3A is a front view showing a bucket pin portion of the measuring device, FIG. 3B is a cross-sectional view taken along line BB of FIG. 3A, FIG. 3C is a cross-sectional view taken along line CC of FIG. (D) is a sectional view showing the angle of the NN axis with respect to the direction of gravitational acceleration.

FIG. 4A is a front view showing a linkage pin portion of the measuring device, and FIG. 4B is a sectional view taken along line BB of FIG.

FIG. 5 is a front view of the hydraulic shovel according to the present invention.

[Explanation of symbols]

D Sediment as the object to be measured in the bucket 11 Lower traveling structure 12 Upper revolving structure 13 Front working mechanism 14 Boom 15 Stick as arm member 16 Bucket 17 to 19, 24 to 28, 33 to 35 Pin 31, 32 As bucket linkage member Straps and rods 41 First load detector 43 Tilt angle detector 44 Second load detector

Claims (5)

[Claims] 1. A work machine for operating a bucket by a work mechanism, comprising: a load detector provided in the work mechanism for measuring a load due to the weight of an object to be measured in the bucket. Weight measuring device. 2. A work machine for operating a bucket by a work mechanism, comprising: a load detector provided in the work mechanism for measuring a load due to the weight of the measurement object in the bucket; A load angle measuring device for a work machine, comprising: a tilt angle detector for detecting a fixed bucket posture suitable for measurement. 3. A load detector comprising: a first load detector for measuring a load applied to a tip of an arm member supporting a bucket by a work mechanism; and a bucket linkage member for controlling a bucket angle by the work mechanism. The load weight measuring device for a working machine according to claim 1, further comprising a second load detector that measures a load applied to the distal end portion. 4. A bucket linkage for connecting a lower traveling structure, an upper revolving structure, a boom, a stick, and a bucket to the upper revolving structure so as to be sequentially rotatable by a pin, and controlling a bucket angle between the stick and the bucket. A work machine having a front working mechanism in which members are rotatably connected by pins, a first load detector installed on a pin connecting a stick and a bucket to measure a load only in a specific direction, and a ground surface of the bucket. An inclination angle detector that detects a specific direction for load measurement by detecting an angle, and a load that is installed on a pin connecting a bucket and a bucket linkage member and that detects a load only in a specific direction detected by the inclination angle detector. A load weight measuring device for a working machine, comprising: a second load detector. 5. The load weight measuring device for a working machine according to claim 4, wherein a load detector and an inclination angle detector are provided inside the pin.