JPH0486528A - Measuring method for mass by use of front loader - Google Patents

Abstract

PURPOSE:To easily measure the mass of a loaded substance by simultaneously detecting the pressures applied to a lift hydraulic cylinder and a posture controlling hydraulic cylinder by a substance at the time of the loading of the substance and measuring the mass of the loaded substance from said pressures. CONSTITUTION:A fork part 4 is loaded with load Wi at an Lx-position and a hydraulic cylinder B7 is controlled when an arm part is raised and lowered to always keep the fork part 4 horizontal. The arm part 2 is raised and lowered in this state and, at the arm angle thetai of a hydraulic cylinder A6 at the time when the arm part 2 is once stopped, a balance formula of moment is calculated with respect to the forces FA, FB applied to the cylinders A6, B7 centering around a fulcrum 3 without considering the mass of the arm part 2 and the fork part 4. Whereupon, W=alphaFA-betaFB (wherein alpha and beta are constants at the time of an angle thetai) is obtained. When the angle thetai is made constant, the constants alpha,beta are calculated by calculation. Therefore, when the forces FA, FB are calculated by measuring the oil pressures of the cylinders A6, B7 at the time of the angle thetai in such a state that the fork part 4 is loaded with a cargo, the mass of a loaded substance can be easily weighed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is capable of quickly measuring the mass of many materials involved in agricultural production, such as agricultural products such as hay and compost, and soil, during the process of transportation and loading. I made it possible.

This article relates to a mass measurement method using a front loader for a 26-type tractor.

[Conventional technology]

In general, it is extremely important for business management to accurately grasp the production amount of coarse substances such as agricultural products such as pasture or compost, and the amount of produced compost and the like input to fields.

Conventionally, in order to ascertain the production volume of coarse materials such as hay and compost, or the amount of produced compost etc. to be input into the fields, it has been necessary to weigh them using a truck scale or load meter, or to rely on experience and intuition. In most cases, there were.

[Problem to be solved by the invention]

However, in the conventional measurement methods mentioned above, there are few cases in which each farmer has installed a truck scale or a load meter, and currently it is difficult to grasp accurate production and input amounts because measurements are based on experience and intuition. This is difficult, and it is difficult to measure each time during continuous work at the site where products are handled, so we are developing technology to more scientifically and quickly measure the mass of coarse substances, etc. on site. is requested.

The present invention has been made in view of the above circumstances, and is mainly used in the agricultural field to handle the mass of agricultural products and materials such as hay and compost that are handled by tractor-mounted front loaders. An object of the present invention is to provide a mass measurement method using a tractor-mounted front loader that can easily measure the mass of coarse substances.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a front loader that is mounted on the front or rear of a tractor so that it can be raised and lowered,
In a front loader having a lifting hydraulic cylinder that controls the lifting and lowering of the front loader using a hydraulic system installed in the tractor and an attitude control hydraulic cylinder that controls the attitude of the loading part, When a substance is loaded, the pressure applied to both hydraulic cylinders is simultaneously detected based on the mass of the substance, and the mass of the loaded substance is measured from this pressure.

[For production]

According to the above measurement method, there are two sets of hydraulic cylinders: one that controls the elevation of the front loader arm, and one that controls the direction of the loading section (fork section) of the front loader tip attachment. When a substance is loaded onto the loading section of the front loader mentioned above, the pressure applied to both hydraulic cylinders and the lifting angle of the front loader arm are detected, and a weighing method that is not affected by changes in the center of gravity of the loaded object is used to easily detect the pressure applied to both hydraulic cylinders and the lifting angle of the front loader arm. It is possible to measure the mass of a substance on-site and quickly.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 is a side view of a front loader attached to the front of a tractor applied to the present invention. In the figure, reference numeral 1 indicates the tractor body, and 2 indicates one end that is rotatable via the fulcrum 3 of the tractor body 1. 4 is a fork portion attached to the tip of the arm portion 2 via a parallel link mechanism 5;
Reference numeral 6 denotes a hydraulic cylinder A for raising and lowering the arm portion 2, and 7 has one end rotatably supported at a predetermined position of the arm portion 2 via a fulcrum 8, and the other end pivotally supported at a predetermined position of the parallel link mechanism 5. Each hydraulic cylinder B is shown.

The hydraulic cylinder A6 and the hydraulic cylinder B7 are both reciprocating type, and two of each are arranged in parallel.

Further, the hydraulic circuits of the hydraulic cylinder A6 and the hydraulic cylinder B7 are each constructed as shown in FIG. cylinder chamber 6a,
7a and rod chambers 6b, 7b alternately.

Then, both the above hydraulic cylinders A6. Force F acting on B7
When A kgf and FB kgr are controlled to be in the fixed position, the following theoretical formulas (1) and (2) are established.

FA-2 (PI Sl -P2 S2 ) ・-・(1
)FB -2(P"1S'I P"28'2) ・
...(2) Here, Pl, p'1 - pressure crab acting on the piston surface from the cylinder side kgr/cd p2. p'2 - Pressure crab acting on the piston surface from the piston rod side kgr/cd sl, s'1 - Effective piston cross-sectional area on the cylinder side s2. s'2 - Piston rod side effective piston cross-sectional area:
c-.

From this, the forces FA kgr and FB kgr applied to both hydraulic cylinders A6 and B7 are the forces applied to the cylinder chambers 6a and 7a side and the rod chamber 6 in the respective hydraulic piping.
b.

By measuring the pressure on the 7b side with the transducer 15, 16 and the static strain meter 17, it can be easily determined using equations (1) and (2).

In the front loader configured as described above, a load W i kg is loaded on the Lx position of the fork part 4, and the hydraulic cylinder B7 is controlled when the arm part 2 is raised and lowered, so that the fork part 4 is always held horizontally. In this state, arm part 2
At the arm angle θl of the hydraulic cylinder A6 when the is raised and lowered and then stopped, the load Wi and the forces FA and F8 applied to both the hydraulic cylinders A6 and B7 centering on the fulcrum 3 are as follows:
If we calculate the moment balance equation without considering the masses of the arm section 2 and fork section 4, we can find that the forces FA and FB are The live load Wi can be determined extremely simply by just measuring.

W i -a F A -β F 8 ・
・Shape φ・(3) In this equation, α and β are constants when the arm angle θi. These constants indicate the distance ratio from the fulcrum to the point of action of each part when the arm angle θi is determined, and once θ1 is determined, the front loader dimension 1
It is possible to obtain it by calculation as a known thing from the specifications indicating the positional relationship. Therefore, α and β are expressed as functions of θi by the following equations (4) and (5), respectively.

α−F(θi)・・・・・・・・・(4)β−G(θi
)...(5) Here, the calculation results when the arm angle θi is 30.39.48 degrees are shown in Table 1.

In addition, although formula (3) ignores the mass of the arm portion 2, etc., in reality, even if no load is loaded on the fork portion 4, force is acting on the hydraulic cylinders A6 and B7. The load on the fork portion 4 is expressed as equation (6) obtained by subtracting this initial load Wkg.

Wi-αFA-βFB-W (6) Note that W is (
3) As is clear from the equation, as a function of θi, (7)
It is shown by the formula.

W-H(θl)・・・・・・(7) W is the arm angle θi with α and β of equations (4) and (5) obtained by calculation, and no load on the fork part 4, At this time, each hydraulic cylinder A6. FA and FB are determined by oil pressure measurement on B7.
It can be determined by substituting into equation (3) and replacing Wi with W.

As explained above, according to the front loader weighing theory formula, if the arm angle θi is constant, α and β can be calculated. In addition, when the fork portion 4 is unloaded and the arm angle is θi, W represents each hydraulic cylinder A6.
It can be determined by measuring the pressure applied to B7.

By determining each coefficient in this way, when a load is loaded on the fork portion 4 and the arm angle is θi, each hydraulic cylinder A6. By measuring the oil pressure of B7 and finding FA and FR, the mass of the loaded cargo can be easily weighed using equation (6).

However, since there are various types and sizes of front loaders, it is not practical to calculate each coefficient in equation (6) for each type and size, and it is difficult to ensure high weighing accuracy. Since it is difficult, it is preferable to use the calibration method.

That is, the equation (6) is expressed as a function of the arm angle θl, and is expressed as the equation (8).

Wi-F(θi) FA-G(θ1)F8H(θl
)・・・・・・(8) In the above equation (8), when two or more known weights with different masses are prepared, each is loaded on the fork part 4, and the arm angle θi is constant. Hydraulic cylinder A6. B7
By measuring the hydraulic pressure of
i), H(θi) can be easily obtained.

For example, for two known weights, 210 kg and 406 kg, the load center position on the fork part 4 is Ocm and 80 cm.
2 levels, and a case where the arm part 2 is raised upward and stopped with the arm angle θi constant.

The arm angle θi is 30.39 for each combination of 8 points in total of 2 levels when lowering from the top to the bottom and stopping.
Table 2 shows an example of the results obtained by the calibration method at 48 degrees. In both cases, the partial correlation coefficients are close to 1.0, which indicates that according to this method, the mass of the substance loaded on the fork portion 4 can be weighed with high accuracy. Also, 320 kg
When the weight is actually loaded on the fork part 4 and the error rate is calculated from the weight calculated by equation (8) from the oil pressure measurement of both hydraulic cylinders A6 and B7, the arm angle θi is 30°39
．． It was demonstrated that 1# can be measured with high accuracy within 1% at any angle of 48 degrees.

In addition, - step forward, both hydraulic cylinders A6. By using transducers 15 and 16 to detect the oil pressure of B7, connecting them to a one-chip microcomputer, and combining equation (8) with calibration software, the loaded weight of the fork section 4 can be displayed immediately. It can also happen. Moreover, the mass of the loaded object can be easily measured in the same manner not only when the fork part 4 of the attachment is connected but also when a packet is connected.

〔Effect of the invention〕

As explained above, according to the mass measurement method using a front loader of the present invention, the carrying load can be determined by detecting the pressure applied to the hydraulic cylinder of the fork section and the arm section of the tractor-mounted front loader and the arm angle. It can be measured and the following effects can be obtained.

■9 Since force is detected simultaneously at two locations, the fork section and the arm section, no matter where the load center of gravity of the load applied to the fork section is, the influence can be ignored, allowing special load correction. does not require.

(2) Since force is detected by measuring the pressure of the hydraulic cylinder, even if the tip attachment is changed from a fork to a packet, etc., the mass of the loaded object can be easily measured as long as calibration is performed.

■It becomes easier to manage the mass of intermediate products such as grass and compost, contributing to the soundness and rationalization of agricultural management.

Examples of theoretical values calculated in the table H(θI) is the theoretical value F(θI) obtained by calculation.

When calculated using G(θl) and substituting experimental data when the fork is not loaded.

Table 2・Example of calibration results

[Brief explanation of drawings]

FIG. 1 is a side view of a front loader applied to the present invention and mounted on the front of a tractor, and FIG. 2 is a diagram showing the hydraulic circuit configuration of a hydraulic cylinder. DESCRIPTION OF SYMBOLS 1... Tractor body, 2... Arm part, 4... Fork part, 6... Hydraulic cylinder A, 7... Hydraulic cylinder B, 9... Hydraulic pump, 10... Manual operation valve,
15.16...Transducer, 17...Static strain meter.

Claims (1)

[Scope of Claims] A front loader mounted on the front or rear of a tractor so as to be able to rise and fall, comprising: a hydraulic cylinder for lifting and lowering that controls the lifting and lowering of the front loader using a hydraulic system installed in the tractor; In a front loader that has an attitude control hydraulic cylinder that controls the attitude of the loading section, when material is loaded on the loading section, the pressure applied to both hydraulic cylinders is simultaneously detected based on the mass, and the mass of the loaded material is calculated from this pressure. A method for measuring mass using a front loader.