JPS62220620A - Automatic excavator for loading machine - Google Patents

Abstract

PURPOSE:To perform automatic excavation of a given amount of soil all the time by alternately and automatically performing the titling operation of bucket and rising operation of boom in such a way that horizontal excavation resistance is reciprocatingly moved between a set upper value and a set lower value. CONSTITUTION:As regards horizontal excavation resistance, a first set value Rhm, an upper limit set value Rhu, and a lower limit set value Rhd are set, and a loading machine is run. In this case, in a controller, the horizontal component Rh and vertical component Rv of excavation resistance to be applied to a bucket 1 are calculated. When the horizontal component Rh becomes greater than the first set value Rhm, the tilting operation of the bucket 1 and the upward turning operation of the boom 3 are alternately switched in a controlled manner so that the horizontal component Rh reciprocatingly moves between the upper limit set value Rhu and the lower limit set value Rhd.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applied to loading machines such as wheel loaders, payloaders, and tractor excavators by controlling the work 1 acticoator with a microcomputer according to the load. This invention relates to an automatic excavation device for a loading machine that enables efficient excavation work without relying on technology.

[Conventional technology]

Loading machines such as wheel loaders, payloaders, and tractor excavators, which actuate booms and buckets as ring actuators, are compact, capable of small turns, and are inexpensive to purchase, making them ideal for civil engineering work sites, livestock farming, etc.
It is used in a wide range of fields such as horticulture, landscaping, and snow removal work.

In this type of loading machine, the boom is rotated up and down by a boom cylinder, and the bucket is tilted and dumped by a bucket. Perform excavation and loading work such as

(Problem to be solved by the invention) By the way, the hydraulic circuit of such a loading machine usually has one bucket.
Since the switching valves that drive the boom cylinder and bucket cylinder are controlled on and off with a fixed flow rate, it is not possible to operate the boom and bucket at the same time. A very high level of skill is required to effectively switch the working equipment's position and position to perform efficient excavation.For this reason, an inexperienced operator may not push the bucket too far horizontally, causing excessive vertical resistance and causing damage to the vehicle. There are many cases where the rear part lifts up, the bucket lifts too quickly and the amount of excavated soil is insufficient, or the tires slip due to excessive load, and the work efficiency varies greatly depending on the driving technique of the driver.

This invention was made in view of the above-mentioned circumstances, and it is possible to operate the current mainstream loading machines, which are equipped with a hydraulic circuit with a fixed flow rate and which can only operate one actuator independently, without changing the configuration. The object of the present invention is to provide an automatic excavation device for a loading machine that can always efficiently excavate a predetermined depth regardless of the skill of the operator.

(Means for solving the problem) In order to solve the problem, in this project, we will provide a means for sequentially calculating the horizontal and vertical components of the excavation resistance applied to the bucket, and a method for calculating the horizontal excavation resistance. setting means for setting a set value of 1, an upper limit set value and a lower limit set value, and also setting a set value regarding the vertical excavation resistance; When the vertical excavation resistance that has been shut out is smaller than the vertical excavation resistance setting 11?1, the bucket is tilted so that the horizontal excavation resistance is reciprocated between the above-mentioned 1IIIX! setting value and the lower limit setting value. In addition, after the vertical excavation resistance calculated above becomes larger than the set value of the vertical excavation resistance, the bucket 1- is controlled to be tilted until the end of the specified excavation. In order to do this, a switching system 611 is provided for controlling switching of each working machine valve for manually driving the boom and bucket.

(Function) According to this configuration, according to the horizontal excavation resistance value, penetration travel → negative dog travel, bucket 1 to pull I- → negative dog travel, boom rise → negative dog travel, bucket I, tilt → filling travel・Due to the boom rising → cycle operation, the horizontal resistance reciprocates between the upper limit set value and the lower limit set value, and after that, when the vertical excavation resistance value exceeds the predetermined set value, the bucket tilt movement is performed. This will continue until the end of the excavation.

〔Example〕

Figure 2 shows the outside l1 of a wheel loader to which this invention is applied.
1i! This wheel loader includes a bucket angle sensor 2 that detects the rotation angle θ1 of the bucket 1, a boom angle sensor 4 that detects the rotation angle θ2 of the boom 3, and a pressure sensor that supplies pressure to the boom cylinder 5. A hydraulic sensor 6 (not shown in FIG. 2) detects the hydraulic pressure pa of oil, and a hydraulic sensor 8 (not shown in FIG. 2) detects the hydraulic pressure Pb of pressure oil supplied to the bucket cylinder 7. is provided.

Detection values θ1, θ2, P a and P of these bucket angle sensor 2, boom angle sensor 4, and oil pressure sensors 6 and 8
b is input to the microcombi 10 as shown in FIG. When using the micro combi coater 10,
Using these detected values, jJa! During excavation, the horizontal component Rh and the vertical component Rv of the excavation resistance applied to bucket 1 are sequentially adjusted, and when in automatic excavation mode, these needle valves 1ffi Rh
The drive control of the hydraulic circuit 20 is performed based on and Rv.

This hydraulic circuit 20 includes a boom control valve 21 that drives the boom cylinder 5, a bucket 1 control valve 22 that drives the bucket cylinder 7, and a tank 23.
, work equipment pump 24, pylon 1 to Δperetocon 1-
A normal ON valve consisting of a roll (POC> pump 25, a lift pilot valve 26 that controls the switching of the boom control l-r+-le valve 21, and a chill 1-pilot 1-valve 27 that controls the switching of the bucket control valve 22). - Switching valves 30 and 40 are added to the OFF control type tandem circuit combination, which are operated by switching signals S1 and $2 from the micro combi coater 10.The switching valve 30 is connected to the lift pilot valve 26. It is installed in the pilot line from the boom controller 1 to the upper lift l-spool 28 of the roll valve 21, and when the off f!I signal '3 S1 is not input, the pilot valve 20 and Although it connects with the side lift spool 28,
When the switching signal $1 is input, the POC pump 25 is directly connected to the upper riff l-spool 28. The switching valve/IO is arranged in the pilot pipe line from the tilt pilot valve 27 to the tilt side dump spool 29 of the bucket control 1-roll valve 22, and when the switching number 16 S2 is not input, the pilot pipe 27 and del]・Side dump spool 2
However, when the switching signal +'i S2 is input, the POC pump 25 is connected to the tilt side dump spool 2.
Directly connected to 9. These switching signals S1 and S2 are activated when the switch 11 is turned on! ++When the excavation mode is designated, it is input from the micro combi coater 10.

Before explaining the automatic excavation operation according to the configuration of this embodiment, an example of a method for deriving the horizontal resistance Rh and the vertical resistance Rv will be explained with reference to FIGS. 3 and 4.

In this method, as input information, bucket rotation angle 01,
Boom rotation angle 02, hydraulic pressure pa and J of pressure oil supplied to the boom cylinder row, and bucket 1 to cylinder 7.
The horizontal resistance Rh and the vertical resistance RV are derived using the detected pressure i11 using the hydraulic pressure pb of the pressure oil.

Now, if the cross-sectional areas of boom cylinder 5 and buckets 1 to 7 are 3a and 3b, respectively, then the cylinder forces Fa and Fb of each cylinder 5 and 7 are Fa = Pa
−3a −(1)Fb =Pb −3
b...(2).

Here, it is assumed that the resistance force PD (XD, YD) changes as shown in FIG. 4 in response to the rotation of the bucket l-1 (rotation angle 01). In the graph shown in Figure 4, the vertical axis is the tip of the bottom plate of bucket 1-!・The distance DI between the seat and the resistance fish PD, the horizontal axis is the bucket rotation angle 0
1, and θh (fixed value) is 1 noid 1 of bucket 1
The angle at which Azalea 1a becomes horizontal, lc is the angle at which Azalea 1a becomes horizontal.
is the length of the part.

Here, considering a mark η with pin Pa as the center, Pi< of pin 1) 1 when bucket i~1 is a rotating surface.
If eY4 is <X1', Y1'), boom 3
The coordinates of Pl (Xl, Yl) lj after 02 rotations, and the illustrated spacing between bucket 1 to pin P1 and the tip point of the bucket bottom plate! J1, the angle between the bucket bottom plate and the side edge 1a of the bucket is ψ, then the PD coordinates (XD, YD) after bucket 1 and boom 3 rotate θ1 and 02, respectively, are x D - x 1 - T.
”) 1 ・cos O1-DI ・COS ψ
... Ku 4) YD = Y1 + Jl 1・Sin
θ1-[)I·sin ψ-(5), and based on the graph of FIG. 4, it is possible to specify the coordinates of PD after θ1,02 rotations.

Now, let the dimensions shown in Figure 3 be Ll and L2.

L3,14. L5 and considering the balance of moments around pin Po, Rv -XD +Rh -YD -Fa -14-Fb
l-s=0... (6)
If we change the balance of moment i around pin P1, Rv ・(XD −1−Xl >−Rh ・(Yl−Y
D)-Fb'L3=O...(7). Since also holds true, Rh and Rv can be found by solving these equations (6)+7) and (8).

Next, refer to the flowchart shown in Figure 5 and check the results! The automatic drilling operation using the oil example configuration will be explained.

In this example, three settings 1 series Rhu, Rhd and Rhn+ (Rhu > Rhnl
> Rhd). Further, regarding the vertical resistance RV, a setting value Rvs as shown in FIG. 6 is set. In other words, the vertical resistance setting value RVS is
If you consider the moment around 12, a bucket will come from the front wheel! - Small center j: Since the length of the horizontal component of the distance changes as the boom 3 rotates, the moment around the front wheel due to the vertical resistance RV! In order to keep the value constant, the height y of the bucket pin P1 is changed as shown in FIG. In addition, the 6th
In the figure, ya is the setting value of the excavation end pin height.

Now, when performing automatic excavation, the operator turns on the automatic excavation mode switch 11, starts the engine,
For example, the gear is set to first speed and the vehicle is driven against the embankment (step 100). During this initial excavation stage,
Horizontal penetration excavation is performed by driving a vehicle with the boom 3 and bucket 1 stopped at their initial positions.

When the microcomputer 10 detects the turning on of the switch 11, it detects each detected value θ1.
θ2. Pa and pb are taken in, and using these detected values, the horizontal resistance Rh and vertical resistance RV are calculated according to the method explained in FIGS. 3 and 4 (step 1).
10). Then, the microphone 1]] coater 10 first sets the horizontal resistance [<11] to the set value 1 (h!'1
1 (step 120), if Rh≦llh+n, return to step 100, and step 100. The procedure of step 110 is executed 714 again. In this case, the boom 3 and the bucket 1 do not rotate from the start of excavation until Rh exceeds the set value RhIn, and the excavation is carried out horizontally. As a result, the horizontal resistance Rh applied to the buckets 1-1 gradually increases as shown in FIG. 7(i).

(1) When the microcomputer 10 detects that Rh>Rlun in the comparison in step 20, it outputs a switching signal P332 to switch the switching valve 40, thereby switching the POC pump 25 Send the song [bucket 1-21-1-n-] to the chill 1 side spool 29 of the lever valve 22, and start the tilt operation of the bucket 1 by moving the bucket 1 to the cylinder 7 to the tilt side. (step 130), As a result, the horizontal resistance Rh
Now gradually decreases as shown in FIG. 7 (TI).

Next, the microcomputer 11r (j - screen 140 for sieving out horizontal resistance Rh and vertical resistance RV)
, the calculated vertical resistance RV is shown in FIG.
If RV≦RVS, the calculated horizontal resistance Rh is further compared with the lower limit set value Rhd of the horizontal resistance (step 170).

As a result of this comparison, the horizontal resistance Rh is set to the lower limit setting value R.
If it is larger than hd (Rh>Rhd), the microcomputer 10 continues sending the switching signal MS2 and further tilts the bucket 1 (step 130).
. After this, as long as RV≦RVS and 11v>Rhd, the microcomputer 10 continues to send out the switching signal S2 and further tilts the buckets 1-1.

However, as a result of the comparison in step 170, if the horizontal resistance Rh is smaller than the lower limit set value Rhd, the microcomputer 10 makes the switch '? At the same time as stopping the sending of JS2 and stopping the tilting movement of the bucket 1, the switching valve 30 is switched to output the switching signal 81, and the oil I of the OC pump 2b is turned off to the boom. The feed is sent to the upper spool 28 of the control valve 21, and the boom cylinder b is driven to the + side (upward) to cause the boom 3 to take a bite (step 180). niJ: So, the horizontal resistance tt h is the 9th peak is the 7th
As shown in the figure (ITI), it tends to increase.

Next, the micro combi coater 10 again applies the horizontal resistance Rh.
, step 190) of launching the RV, unless the boom angle θ1 exceeds a predetermined set angle (step 200), then compare the calculated vertical resistance RV with the setting il/1Rvs (step 210), Rv> 1-(vs), the calculated horizontal resistance 41 (resistance Rh) is further compared with the lower limit set value Rh++ of the horizontal resistance (step 220).

As a result of this comparison, the horizontal resistance Rh is set to the lower limit setting value R.
If less than Rhu (Rh≦Rhu), the microcombi coater 10 first compares and overrules this horizontal resistance Rh with the horizontal resistance value Rhp used previously (step 230). If the result of this comparison is Rt+≧Rhp, the micro combi coater 101. L l'lFI F:
+: Continue sending the switching signal S1 and turn the boom 3 one more time! (step 180). From this point on, the micro combi coater 10 uses RV≦Rvs, Rh≦Rhu
.

Continue sending the switching signal S1 as long as Rh≧Rhp,
Raise and rotate boom 3.

Then, the microcomputer 10 performs step 220.
When the result of the pull comparison becomes Rh>Rhu, that is, when the horizontal resistance Rh exceeds the upper limit setting &rRhu, the transmission of the switching signal S1 is stopped and the upward movement of the boom 3 is stopped. , this time by outputting the switching signal $2, the movement of bucket 1 to chill 1 is resumed (step 130).The horizontal resistance Rh is as shown in FIG. 7 (IV) due to the tilt movement of the bucket. It goes down again.

Furthermore, in the microcomputer 10, when the horizontal resistance Rh becomes smaller than the previous horizontal resistance calculation value Rhp during the lower hair of the boom 3 described above, (Rh <'Rhp
), similarly to above, the transmission of the switching signal S1 is stopped and the upward movement of the boom 3 is immediately stopped. At the same time, it outputs the switching signal $2 and switches the bucket 1-1 to
(step 130). 1. In other words, in this case, the horizontal resistance Rh of the boom may slowly descend without reaching the upper limit set value Rhu of the horizontal resistance, and in this case, the boom J: The soil will continue to be damaged while the horizontal excavation resistance Rh is insufficient. Therefore, while the boom is on yr, in step 230, the horizontal resistance Rh is calculated by comparing the current horizontal resistance IF Rh with the horizontal resistance value Rhp calculated immediately before.
If the lowering is detected, the horizontal resistance value Rh is forcibly adjusted by stopping the upward movement of the boom and chilling the bucket as shown in Fig. 7(v). Lower the horizontal resistance value Rh to the lower limit set value Rhd, and then raise the boom again to set the horizontal resistance value Rh to the upper limit (if + R
I am trying to increase it to hu.

Therefore, the micro combi coater 10 stores and stores the horizontal resistance values Rh calculated in sequence.

In this way, the horizontal resistance Rh can be changed 11 times between the upper limit set value Rhu and the lower limit set value Rhd by alternately performing the PiA return drive to the boom single-stack drive d-3 and the bucket chill 1. become. When the vertical resistance RV becomes larger than the set value RVSJ while performing such switching drive, the microcomputer 10 detects this in step 160 or step 210, and then moves the procedure to step 2=10. Ru. In other words, step 16
If Rv>Rvs is detected at 0, the micro combi coater 10 moves the procedure to step 240 by continuing to send out the switching signal S2, and then proceeds to step 21.
When RV>RVS is detected at 0, the switching signal S
The procedure proceeds to step 240 by stopping the transmission of signal $1 and outputting switching signal $2.

Thereafter, the micro combi coater 10 continues to output the switching signal S2 until the end of the predetermined excavation (step 25O) after tilting the bucket 1 by a predetermined angle. ). The method of detecting the end of excavation is to determine the end of excavation when the sand edge 1a of bucket l-1 becomes horizontal, and to determine the end of excavation when the ground height of bucket pin P1 reaches a predetermined height. There are methods to detect the stroke end of bucket shillings, etc.

In addition, in the above control procedure, when the stroke end of the bucket shilling is detected (step 150) or when the boom angle exceeds a predetermined set value (step 2
00), the procedure moves to step 240, after which the excavation operation is terminated. This is the horizontal resistance value R
h and vertical resistance ih Rv and each setting value Rhd, Rhu
Only switching control based on comparison with OJ: and RVS
The excavation operation may not end forever, and as a countermeasure, the above step is added by 0.

Furthermore, in the above control procedure, initially, the horizontal resistance Rh
is set to a value smaller than the upper IR setting value Rhu (f+
Comparing with Rhll, when Rh>Rhn, bucket 1~dilt movement is started J: Sea urchin. In other words, at the beginning of excavation, the vehicle speed is too high, so the start of rotation of the bucket is delayed, and as a result, tire slip etc. often occur.As a countermeasure, horizontal resistance Rh is reduced at the beginning of excavation. The bucket rotation start timing is intentionally accelerated by comparing it with a set value Rton that is smaller than the upper limit set value Rhu. Of course, it is desirable to take such measures, but the set value Rh
The upper limit set value Rhu may be substituted for n+, and only the upper limit set values Rh, u and the lower limit set value Rhd may be set for the horizontal resistance.

According to this embodiment, the upper and lower limit set values Rhu and Rhd are set for the horizontal resistance, and the set value RVS as shown in FIG. 6 is set for the vertical resistance, and the horizontal resistance Rh detected sequentially and the upper limit are set. The horizontal resistance Rh is reciprocated between the upper limit setting value Rhu and the lower limit setting value Rhd by alternately tilting the bucket and rotating the boom upward according to the comparison result with the upper limit setting value Rhu and the lower limit setting value Rhd. From the time the resistance detection value RV exceeds the set value RVS until the end of the specified excavation, the bucket is tilted l+Jza1! Since the automatic excavation is carried out in such a manner that the excavation is carried out automatically, a predetermined width of earth and sand can always be automatically excavated and released without causing problems such as tie slips and failure of the excavator. In addition, according to this automatic excavation control, the actuator that is activated is always one of the baffler 1 to the cylinder or the back of the boom cylinder, so the current mainstream model, a tandem with a fixed flow rate, It is possible to perform excavation like a room by only partially changing the internal configuration of the loading machine equipped with 11 circuits of oil! ! + It is possible to realize an excavation machine.

In the above embodiment, it is also possible to adopt a configuration in which the horizontal resistance upper and lower limit setting values Rhu and Rhd and the vertical resistance setting value Rv can be arbitrarily changed each time one excavation is completed.

Furthermore, the calculation method for determining the horizontal resistance Rh and the vertical resistance RV is not limited to the method explained using Figs. 3 and 4; The load applied to the bucket 1- by the sugar can be detected, and 'a' Rh and Rv may be determined based on the force balance between the detected value and the horizontal and vertical resistances Rh and Rv.

Furthermore, the loading machine to which the present invention is applied is not limited to wheel loaders, but may also include payloaders, tractor excavators, etc.
The actuator is applicable to all machines that have a boom and a bucket as an actuator.

(Effect of the explanation) As explained above, according to this explanation, (1) the boom drive and bucket drive are switched and controlled according to the excavation resistance, so there is no possibility that the excavation resistance becomes excessive; This makes it possible to prevent tire slip and extend the life of the tires, and to greatly improve excavation efficiency. (3) Since the actuator in operation is always either the bucket or the boom, it is suitable for application to loading machines with a tandem circuit configuration, which is currently the mainstream. It has a great effect.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing an example of the overall control configuration of a device according to an embodiment of the present invention, Fig. 2 is a side view showing the external configuration of a wheel loader and an example of arrangement of each sensor, and Fig. 3 is a horizontal/vertical diagram. A diagram for explaining an example of calculation for determining the resistances Rh and Rv, FIG. 4 is a graph showing an example of a set movement locus of the resistance application point used in the example of calculation, and FIG. 5 is a specific example of the apparatus of the embodiment FIG. 6 is a flowchart showing an example of the operation, FIG. 6 is a graph showing the relationship between the vertical resistance setting value RVS and the bucket height y, and FIG. 7 is a diagram showing the change in horizontal resistance due to the device of this embodiment. 1...Bucket, 2...Bucket angle sensor, 3...
・Boom, 4...Boom angle sensor, 5...Boom cylinder, 6.8...Hydraulic pressure sensor, 7...Baffler 1~
Cylinder, 10...Micro combination coater, 20...
・Hydraulic circuit, 21...Boom control valve, 2
2... Bucket control valve, 23... Tank, 24... Work equipment pump, 25... POC pump, 26... Lift pilot valve, 27... Tilt pilot valve, 28.29 ...Spool, 30.4
0...Switching valve. Figure 2 Figure 3 θh θl Figure 4 Figure 6

Claims (5)

[Claims] (1) In an automatic excavation device for a loading machine that performs excavation by automatically driving and controlling the boom and bucket while the loading machine is running, the horizontal component of the excavation resistance applied to the bucket and means for sequentially excluding the vertical component; setting means for setting a first setting value, an upper limit setting value, and a lower limit setting value regarding the horizontal excavation resistance; and setting means for setting a setting value regarding the vertical excavation resistance; When the calculated horizontal excavation resistance is larger than the first set value and the calculated vertical excavation resistance is smaller than the set value of the vertical excavation resistance, the horizontal excavation resistance is set to the upper limit set value and the lower limit set value. The tilting movement of the bucket and the lifting rotation of the boom are controlled alternately so that the bucket is reciprocated between An automatic excavation device for a loading machine, comprising switching control means for controlling switching of each working machine valve that drives a boom and a bucket, respectively, in order to tilt the bucket. (2) The automatic excavation device for a loading machine according to claim 1, wherein the first setting value set in the setting means is a value between a lower limit setting value and an upper limit setting value. (3) The automatic excavation device for a loading machine according to claim 1, wherein the first setting value in the setting means is set to the same value as the upper limit setting value. (4) When the calculated horizontal excavation resistance is larger than the first set value and the calculated vertical excavation resistance is smaller than the set value of the vertical excavation resistance, the switching control means performs the calculated horizontal excavation. When the resistance exceeds the upper limit set value and then decreases to the lower limit set value, the bucket is tilted, and when the calculated horizontal excavation resistance becomes smaller than the lower limit set value and then rises to the upper limit set value, the boom is activated. The automatic excavation device for a loading machine according to claim 1, wherein switching control is performed on each of the working machine valves to perform upward rotation. (5) In an automatic excavation device for a loading machine that performs excavation by automatically driving and controlling the boom and bucket while the loading machine is running, the horizontal component of the excavation resistance applied to the bucket and means for sequentially calculating the vertical component; a detection means for detecting a decrease in the horizontal excavation resistance during the boom upward drive by comparing the calculated horizontal excavation resistance with the previously calculated horizontal excavation resistance during the boom upward movement; Setting means for setting a first setting value, an upper limit setting value, and a lower limit setting value regarding horizontal excavation resistance, and setting a setting value regarding the vertical excavation resistance; and when the calculated horizontal excavation resistance is smaller than the set value of the vertical excavation resistance, or when the calculated horizontal excavation resistance exceeds the upper limit set value and then decreases to the lower limit set value, or the detection means When a detection signal is output from , the bucket is tilted, and when the calculated horizontal excavation resistance becomes smaller than the lower limit set value and rises to the upper limit set value, the boom is raised and rotated. When the vertical excavation resistance exceeds the set value of the vertical excavation resistance, switching control is performed on each work equipment valve that drives the boom and bucket, respectively, in order to tilt the bucket until the specified end of excavation. An automatic excavation device for a loading machine, comprising switching control means.