JP5281461B2 - Plowing depth control structure of tillage machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tilling depth control structure of a tillage work machine, which can prevent the generation of an engine stall caused by the overload of an engine without using the revolution of the engine as an index for preventing the engine stall. <P>SOLUTION: This tilling depth control structure of the tillage work machine is characterized by having a driving means 41 for lifting or lowering a rotary tiller 3 on the basis of a travel vehicle body 1 having an engine 6 loaded thereon, a setting means 56 for setting a control target tilling depth of the rotary tiller 3, a detection means 53 for detecting the tilling depth of the rotary tiller 3, a control means 25A for controlling the operation of the driving means 41 so that the output of the detection means 53 may correspond to the output of the setting means 56, and a calculation means 62 for calculating the fuel injection quantity of the engine 6, wherein the control means 25A corrects the control target tillage depth on the shallow side on the basis of a threshold and the output of the calculation means 62 when the output of the calculation means 62 exceeds the threshold for preventing engine stall, and controls the operation of the driving means 41 so that the output of the detection means 53 may correspond to the control target tillage depth after the correction. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a driving means for connecting a rotary tiller to a rear portion of a traveling vehicle body mounted with an engine so that the rotary tiller can be raised and lowered, and a setting means for setting a control target tillage depth of the rotary tiller. Detecting means for detecting a tilling depth of the rotary tiller, and based on the output of the setting means and the output of the detecting means, the driving means so that the output of the detecting means corresponds to the output of the setting means The present invention relates to a tilling depth control structure of a tilling work machine provided with a control means for controlling the operation of the tiller.

  The tilling depth control structure of the tillage work machine as described above includes a sensor that detects engine overload by increasing or decreasing the engine speed, and the control means detects engine overload based on the output of the sensor. In this case, the operation of the driving means is controlled so that the tillage depth of the rotary tiller becomes shallower, and the engine overload is controlled in preference to the control action based on the output of the setting means and the output of the detecting means. There is one configured to prevent the occurrence of engine stall due to overload by eliminating (see, for example, Patent Document 1).

Japanese Patent Publication No. 63-52841

  By the way, in the tillage work machine, by adjusting the fuel injection amount and the like based on the engine load, the control target rotation corresponding to the operation position of the accelerator operating tool regardless of the fluctuation of the engine load. Some are configured to perform isochronous control that maintains the number. When the above-described tilling depth control structure is employed in such a tilling work machine, it becomes impossible to detect an engine overload, and as a result, it is impossible to prevent the occurrence of an engine stall due to the engine overload.

  An object of the present invention is to prevent the occurrence of engine stall due to engine overload without using the engine speed as an index for preventing engine stall.

In order to achieve the above object, in the invention according to claim 1 of the present invention,
A rotary tiller is connected to the rear part of the vehicle body with the engine so that it can be raised and lowered.
Drive means for driving the rotary tiller up and down;
Setting means for setting a control target tillage depth of the rotary tiller,
Detecting means for detecting a tilling depth of the rotary tilling device;
Based on the output of the setting means and the output of the detection means, the tilling depth of a tilling work machine provided with a control means for controlling the operation of the drive means so that the output of the detection means corresponds to the output of the setting means In the control structure,
Computation means for computing the fuel injection amount or load factor of the engine,
The control means corrects the control target working depth to a shallow side based on the output of the calculation means and the threshold when the output of the calculation means exceeds a threshold for preventing engine stall, and the control after correction Based on the target tilling depth and the output of the detecting means, the operation of the driving means is controlled so that the output of the detecting means corresponds to the corrected control target tilling depth.

  According to this characteristic configuration, the fuel injection that the calculation means outputs because the engine load suddenly increases together with the load on the rotary tiller due to entering into a deep depression or suddenly hard soil in the field. When the amount or the load factor exceeds the threshold value for preventing engine stall, the control means corrects the control target working depth to the shallow side based on the output and the threshold value of the computing means, and the corrected control target working depth and Based on the tillage depth of the rotary tiller output from the detection means, the operation of the drive means is controlled so as to raise the rotary tiller so that the tillage depth of the rotary tiller corresponds to the corrected control target tillage depth. .

  As a result, even if the engine load suddenly increases with the load on the rotary tillage device due to entering the deep depression or the soil quality of the field suddenly becoming hard, the engine stall caused by it is prevented. Can do.

  In other words, in a tillage work machine that performs isochronous control during tillage work, engine stall caused by engine overload during tillage work can be achieved by using the fuel injection amount or load factor of the engine as an index for preventing engine stall. Can be prevented.

  Also, if the load factor of the engine is, for example, the ratio of the actual intake air amount to the reference maximum intake air amount per rotation of the engine calculated based on the intake pressure and the engine speed, isochronous control is not performed during tillage work. Also in the tillage work machine, by using the engine load factor as an index for preventing engine stall, it is possible to prevent occurrence of engine stall due to engine overload during tillage work.

  Therefore, it is possible to prevent the occurrence of engine stall due to engine overload during tillage work without using the engine speed as an index for preventing engine stall.

In the invention according to claim 2 of the present invention, in the invention according to claim 1,
The traveling vehicle body is provided with isochronous control means for maintaining the output rotational speed of the engine at a control target rotational speed corresponding to the operating position of the accelerator operating tool by adjusting a fuel injection amount based on the load of the engine. It is characterized by being.

  According to this characteristic configuration, by operating the isochronous control means at the time of tillage work, regardless of the engine load fluctuation at the time of tillage work, the engine output speed corresponds to the operating position of the accelerator operating tool. The vehicle speed can be kept constant.

  Therefore, the work efficiency at the time of tillage work can be improved.

In the invention according to claim 3 of the present invention, in the invention according to claim 1 or 2,
The calculation means calculates a change amount of the fuel injection amount or the load factor with respect to the threshold value and a change amount of the fuel injection amount or the load factor at a set time,
The control means corrects the control target plowing depth based on the two variations.

  According to this feature configuration, not only the amount of change in the fuel injection amount or load factor relative to the control reference value but also the amount of change in the fuel injection amount or load factor during the set time is taken into account when correcting the control target tillage depth. Thus, the tendency of change in the fuel injection amount or the load factor can be reflected.

  Therefore, in order to prevent the occurrence of engine stall due to engine overload during tillage work, the control target tillage depth can be corrected more appropriately, and as a result, the rotary tillage device is not raised excessively. The occurrence of engine stall due to engine overload during tillage work can be prevented.

It is a whole side view of a tilling machine. It is a block diagram which shows a control structure. It is a schematic plan view which shows the transmission structure of a tractor. It is a flowchart of cover plowing depth control. It is a flowchart of engine stall prevention control. It is a figure which shows the relationship between the fuel injection amount, an engine speed, and the threshold value for engine stall prevention. It is a flowchart of load plowing depth control. It is a figure which shows the relationship between the fuel injection amount, an engine speed, and the control reference value of load plow control.

  Hereinafter, an example of the form for implementing the tilling depth control structure of the tillage working machine concerning the present invention is explained based on a drawing.

  As shown in FIG. 1, a tilling work machine connects a rotary tiller 3 to a rear part of a tractor (an example of a traveling vehicle body) 1 via a work mechanism connecting link mechanism 2 so that the rotary tiller 3 can be raised and lowered. It is comprised by.

  The tractor 1 is equipped with a pair of left and right front wheels 4L and 4R so as to be steerable and drivable, and a pair of left and right rear wheels 5L and 5R are drivably equipped so as to be configured as a four-wheel drive type. A water-cooled diesel engine (hereinafter abbreviated as “engine”) 6 is mounted on the front half of the tractor 1, and a radiator 7, a fuel tank 8, and the like are provided. The engine 6 is connected to a transmission case (hereinafter abbreviated as T / M case) 9 also serving as a vehicle body frame. In the latter half of the tractor 1, a front wheel steering wheel 10, a driver's seat 11, and the like are provided to form a boarding operation unit 12, and a cabin 13 that covers the boarding operation unit 12 is provided.

  As shown in FIG. 2, the engine 6 includes a common rail fuel injection device 14 that electronically controls the fuel injection amount and the injection timing. The fuel injection device 14 includes a supply pump 15 that pumps fuel stored in the fuel tank 8, a common rail 16 that accumulates the pumped fuel, and a plurality of electronically controlled injectors that inject the accumulated fuel into a fuel chamber (not shown). 17, a pressure sensor 18 for detecting the internal pressure of the common rail 16, an electromagnetic pickup type rotation sensor 19 for detecting the output rotation speed of the engine 6, and the supply pump 15 and each of the pumps based on outputs from the pressure sensor 18 and the rotation sensor 19. An engine electronic control unit (hereinafter abbreviated as engine ECU) 20 that controls the operation of the injector 17 and the like is provided.

  The engine ECU 20 is configured using a microcomputer provided with a CPU, an EEPROM, and the like. The engine ECU 20 includes first accelerator control means 20A for controlling the fuel injection amount and the injection timing based on the output of the accelerator pedal sensor 22 for detecting the depression operation amount of the accelerator pedal 21 provided in the boarding operation unit 12, Second accelerator control means for controlling the fuel injection amount and the injection timing based on the output of an accelerator lever sensor 24 for detecting the operation position of an accelerator lever (an example of an accelerator operating tool) 23 provided in the boarding operation unit 12 ( An example of isochronous control means: 20B, injection amount calculation means 20C for calculating the fuel injection amount per stroke (hereinafter abbreviated as fuel injection quantity), load rate calculation means 20D for calculating the load factor of the engine 6, etc. Is provided.

  The accelerator pedal 21 is configured to return and swing toward the depression release position. The accelerator lever 23 is configured to be able to hold a position at an arbitrary operation position.

  The first accelerator control means 20 </ b> A performs a droop control that reduces the output rotational speed of the engine 6 from the set rotational speed set by the accelerator pedal 21 as the load of the engine 6 increases. The second accelerator control means 20B adjusts the fuel injection amount and the injection timing according to the load of the engine 6 so that the output rotational speed of the engine 6 corresponds to the operation position of the accelerator lever 23 regardless of the load of the engine 6. Isochronous control is performed to maintain the control target rotational speed.

  The engine ECU 20 is connected to a main electronic control unit (hereinafter abbreviated as main ECU) 25 mounted on the tractor 1 so as to be able to communicate with each other by in-vehicle communication such as CAN (Controller Area Network) communication. Thereby, information such as the output of the rotation sensor 19, the output of the injection amount calculation means 20C, the output of the load factor calculation means 20D, the output of the pedal sensor 22 for the accelerator, and the output of the lever sensor 24 for the accelerator, etc. It can be output from the engine ECU 20 to the main ECU 25. The main ECU 25 is configured using a microcomputer having a CPU, an EEPROM, and the like.

  As shown in FIGS. 1 and 3, the power from the engine 6 is supplied to the inside of the T / M case 9, and is divided into traveling and working by a double shaft structure in the inside. The driving power is shifted by a main transmission 26 for driving that enables eight-speed shifting, and is switched to forward or reverse by a forward / reverse switching device 27 that also serves as a traveling clutch. After shifting by the sub-transmission 28 for traveling, the front wheel drive and the rear wheel drive are divided. The power for driving the front wheels can be taken out from the T / M case 9 via the front wheel transmission 29 that also serves as a clutch for the front wheels. The power for driving the front wheels taken out from the T / M case 9 is transmitted to the left and right front wheels 4L and 4R via the front wheel differential device 30 that allows the left and right front wheels 4L and 4R to be differential. The power for driving the rear wheels is transmitted to the left and right rear wheels 5L and 5R via the rear wheel differential device 31 and the like that allow the differential between the left and right rear wheels 5L and 5R. The working power is transmitted to the working power take-out shaft 34 through the working clutch 32 and the working transmission 33 that enables switching between three speeds and forward / reverse rotation. Thereby, working power can be taken out from the T / M case 9. The working power extracted from the T / M case 9 is transmitted to the input shaft (not shown) of the rotary tiller 3 via the transmission mechanism 35.

  The main transmission 26, the forward / reverse switching device 27, the front wheel transmission 29, the working clutch 32, and the working transmission 33 are configured in an electrohydraulic control type. The auxiliary transmission 28 is constructed in a synchromesh type. Although not shown, the transmission mechanism 35 is configured to be extendable and bendable by a fitting type transmission shaft that integrally rotates so as to be relatively slidable, a pair of front and rear universal joints, and the like.

  As shown in FIG. 1, the rotary tiller 3 includes a frame 36 that is coupled to the link mechanism 2, a tiller rotor 37 that rotates about a left-right axis, and a transmission mechanism that transmits power from the tractor 1 to the tiller rotor 37. 38, a fixed upper cover 39 covering the top of the tilling rotor 37, a vertically swinging rear cover 40 covering the rear of the tilling rotor 37, and the like. The rear cover 40 swings and displaces in the vertical direction with respect to the upper cover 39 according to the tilling depth of the rotary tiller 3.

  As shown in FIGS. 1 and 2, at the rear part of the T / M case 9, an elevating driving means (driving means described in claims) 41 for raising and lowering the rotary tiller 3 with respect to the tractor 1 is provided. Equipped. The drive means 41 for raising / lowering is a pair of left and right lift cylinders that swing and drive the pair of left and right lift arms 42L and 42R and the left and right lift arms 42L and 42R that are mounted on the T / M case 9 so as to be swingable up and down. 43L, 43R, and an electromagnetic control valve 44 for raising and lowering that changes the length of the left and right lift cylinders 43L, 43R by controlling the flow of hydraulic oil to the left and right lift cylinders 43L, 43R. It is configured. Single acting hydraulic cylinders are employed for the left and right lift cylinders 43L and 43R, respectively.

  The tilling work machine is equipped with a driving means 45 for rolling that causes the rotary tiller 3 to roll with respect to the tractor 1. The driving means 45 for rolling includes a turnbuckle-type connecting rod 46 for connecting the left lower link 2L of the link mechanism 2 to the left lift arm 42L, and the right lower link 2R of the link mechanism 2 to the right lift arm 42R. An electro-hydraulic control type is configured by a rolling cylinder 47 to be connected and a rolling electromagnetic control valve 48 for controlling the flow of hydraulic oil to the rolling cylinder 47 to change the length of the rolling cylinder 47 with respect to the linkage rod 46. It is. A double-acting hydraulic cylinder is adopted as the rolling cylinder 47.

  As shown in FIG. 2, the main ECU 25 includes a lifting control unit 25 </ b> A that performs lifting control for controlling the operation of the driving unit 41 for lifting and a rolling control that performs rolling control for controlling the operation of the driving unit 45 for rolling. Means 25B and the like are provided.

  When the elevation control means 25A detects the operation of the height setting lever 49 based on the output of the height setting lever sensor 50 that detects the operation position of the height setting lever 49 provided in the boarding operation unit 12. Perform height control. Further, when a swing operation from the neutral position of the lift command lever 51 to the lift position is detected based on the output of the lift command lever sensor 52 that detects the operation of the lift command lever 51 provided in the boarding operation unit 12 Ascending control is performed. On the contrary, when a swing operation from the neutral position to the lowered position of the elevation command lever 51 is detected, the lowering control is performed. Then, during the execution of the height control or the descent control, the grounding of the rotary tiller 3 is performed based on the output of the cover sensor (an example of a detection means) 53 that detects the vertical swing angle of the rear cover 40 of the rotary tiller 3. Is detected, the height control or the descending control is switched to the tilling depth control.

  In height control, the output of the lever sensor 50 for setting the height, the output of the arm sensor 54 for detecting the vertical swing angle of the lift arms 42L and 42R, and the correlation for height control corresponding to these outputs. Based on the relational data, the drive means for raising and lowering so that the output of the arm sensor 54 corresponds to the output of the lever sensor 50 for height setting (contains within the dead band width of the output of the lever sensor 50 for height setting). 41 is controlled. When the ground contact of the rotary tiller 3 is detected based on the output of the cover sensor 53, the height control is switched to the tilling depth control.

  The correlation data for height control corresponds to the output of the height setting lever sensor 50 as the control target height of the rotary tiller 3 and the output of the arm sensor 54 as the height of the rotary tiller 3 relative to the vehicle body. Map data or relational expressions.

  That is, by operating the height setting lever 49, the rotary tiller 3 can be positioned at any height relative to the vehicle body according to the operation position of the height setting lever 49. Then, by operating the height setting lever 49 to the operation position where the rotary tiller 3 is grounded, the tilling depth control can be performed.

  In the ascent control, regardless of the operation position of the height setting lever 49, the output of the upper limit setting dial 55 provided in the boarding operation unit 12, the output of the arm sensor 54, and the correlation for the ascending control corresponding to these outputs. Based on the relational data, the operation of the driving means 41 for raising and lowering is controlled so that the output of the arm sensor 54 corresponds to the output of the upper limit setting dial 55 (contains within the dead band width of the output of the upper limit setting dial 55).

  The correlation data for ascent control is map data in which the output of the upper limit setting dial 55 is the control target upper limit height of the rotary tiller 3 and the output of the arm sensor 54 is the height of the rotary tiller 3 relative to the vehicle body. Or a relational expression.

  That is, the rotary tiller 3 can be raised to the upper limit position set by the upper limit setting dial 55 by swinging the elevation command lever 51 to the raised position.

  In the descending control, the output of the arm means 54 corresponds to the output of the height setting lever sensor 50 (contains within the dead band width of the output of the height setting lever sensor 50). Control the operation. When the ground contact of the rotary tiller 3 is detected based on the output of the cover sensor 53, the control is switched from the descending control to the tilling depth control.

  That is, the rotary tiller 3 can be lowered to the height set by the height setting lever 49 by swinging the elevation command lever 51 to the lowered position. Further, by operating the height setting lever 49 to the operation position where the rotary tiller 3 contacts the ground, the tilling control can be performed following the descending control.

  In the plowing depth control, the plowing depth of the rotary plowing device 3 is controlled by controlling the operation of the elevating drive means 41 based on the output of the plowing depth setting dial (an example of setting means) 56 provided in the boarding operation unit 12. Is maintained at the control target plowing depth set by the plowing depth setting dial 56.

  The height setting lever 49 can be held at an arbitrary operation position. The raising / lowering command lever 51 is configured to automatically return to the neutral position. A rotary potentiometer is employed for the lever sensor 50, arm sensor 54, cover sensor 53, upper limit setting dial 55, and tilling depth setting dial 56 for height setting.

  Although not shown, the lift command lever sensor 52 includes a limit switch that detects a swing operation of the lift command lever 51 to the raised position, and a limit that detects a swing operation of the lift command lever 51 to the lowered position. It is composed of switches.

  As shown in FIG. 2, the rolling control means 25 </ b> B switches the rolling control to be executed based on the operation of the selection switch 57 for rolling control provided in the boarding operation unit 12. The rolling control includes a horizontal land control for maintaining the rotary tiller 3 at an arbitrary roll angle in a horizontal field, and an inclined land for maintaining the rotary tiller 3 at an arbitrary roll angle during work traveling along a contour line in an inclined field. There is control.

  In the horizontal land control, the ground roll angle of the rotary tiller 3 is set to the roll angle based on the output of the roll angle setting dial 58 provided in the boarding operation unit 12 and the output of the rolling sensor 59 that detects the roll angle of the tractor 1. The control target roll angle of the rotary tiller 3 with respect to the tractor 1 required for maintaining the control target roll angle set by the dial 58 is calculated, the control target roll angle of the rotary tiller 3 with respect to the tractor 1 and the rolling cylinder Based on the correlation data for rolling control in which the output of the stroke sensor 60 for detecting the length 47, the control target roll angle of the rotary tiller 3 with respect to the tractor 1 and the output of the stroke sensor 60 are associated with each other, the rolling cylinder 47 is the length of rotary tiller for tractor 1 Corresponding to the control target roll angle of the device 3 (fit to control the target roll angle within the dead zone) so to control the operation of the driving means 45 for rolling.

  As a result, the ground roll angle of the rotary tiller 3 can be maintained at the control target roll angle set by the roll angle setting dial 58 regardless of the rolling of the tractor 1 when working on a horizontal field, and the tilling depth setting can be maintained. The field can be cultivated at the plowing depth set by the dial 57.

  In the inclined land control, the tractor 1 is operated based on the correction value set in consideration of the amount of settlement of the front wheels 4L and 4R and the rear wheels 5L and 5R located on the valley side while performing the same control operation as in the horizontal land control. The control target roll angle of the rotary tiller 3 is corrected.

  This makes it possible to perform suitable rolling control in consideration of the amount of settlement of the valley-side wheels 4L, 4R, 5L, and 5R during work traveling in which the tillage working machine travels along the contour line in the inclined farm field. Even during the work traveling at, the field can be plowed at the plowing depth set by the plowing depth setting dial 57 regardless of the rolling of the tractor 1.

  Note that a momentary switch is employed as the selection switch 57 for rolling control. The roll angle setting dial 58 employs a rotary potentiometer. The stroke sensor 60 employs a sliding potentiometer.

  Although not shown in the drawings, the correction value for the control target roll angle for the vehicle body is stored in the correction value storage means provided in the main ECU 25, and is used for setting the correction value provided in the boarding operation unit 12. By operating the switch, it can be changed according to the hardness of the soil, which differs from field to field. The correction value storage means employs a nonvolatile memory such as an EEPROM.

  The rolling sensor 59 includes a capacitance type tilt sensor and a vibration type angular velocity sensor. Further, the rolling sensor 59 may be constituted only by an inclination sensor.

  As shown in FIGS. 2 and 4 to 8, the lifting control means 25 </ b> A switches the plowing depth control mode to be executed based on the operation of the plowing depth control selection switch 61 provided in the boarding operation unit 12. The working depth control mode includes cover working depth control and load working depth control.

  In the cover plowing depth control, the fuel injection amount output by the injection amount calculation means 20C of the engine ECU 20, the output of the cover sensor 53, and the output of the plowing depth setting dial 56 are read, and the fuel injection amount is a threshold value for preventing engine stall ( It is determined whether or not the value exceeds (see FIG. 6). If the threshold value is not exceeded, the output of the cover sensor 53, the output of the plowing depth setting dial 56, and the correlation data for cover plowing depth control that correlates these outputs are output from the cover sensor 53. The operation of the driving means 41 for raising and lowering is controlled so as to correspond to the output of the tilling depth setting dial 56 (contains within the dead zone width of the output of the tilling depth setting dial 56) (see FIG. 4).

  The correlation data for cover plowing depth control is a map in which the output of the plowing depth setting dial 56 corresponds to the control target plowing depth of the rotary tiller 3 and the output of the cover sensor 53 corresponds to the plowing depth of the rotary tiller 3. Data or relational expressions.

  That is, in the cover plowing depth control, the vertical swing angle of the rear cover 40 that varies with the plowing depth of the rotary tiller 3 due to the pitching of the tractor 1 or the like is used as an index for the plowing depth control. Thereby, regardless of the pitching of the tractor 1 and the like, the field can be plowed with the plowing depth set by the plowing depth setting dial 56.

  When it exceeds the threshold value, the engine stall prevention control is performed in preference to the cover plowing depth control (see FIG. 4). In the engine stall prevention control, the operation of the drive means 41 for raising and lowering is controlled based on the fuel injection amount output from the injection amount calculating means 20C and the threshold value for preventing engine stall so that the fuel injection amount falls below the threshold value. Then, the rotary tiller 3 is raised. Then, when the fuel injection amount falls below the threshold value by this engine stall prevention control, the engine stall control returns from the engine stall prevention control to the cover plowing depth control (see FIG. 5).

  That is, in the engine stall prevention control, when the load applied to the rotary tiller 3 increases, the fuel injection amount increases with the engine load, and the fuel injection amount exceeds the engine stall prevention threshold. In this case, the rotary tiller 3 is raised to reduce the engine load.

  As a result, when the load on the rotary tiller 3 suddenly increases due to entering a deep pit or the soil soil suddenly hardens, the fuel injection amount exceeds the threshold for preventing engine stall. Even if it exists, generation | occurrence | production of an engine stall can be prevented.

  In the load plowing depth control, the fuel injection amount output by the injection amount calculating means 20C, the output of the arm sensor 54, the output of the plowing depth setting dial 56, and the like are read, and the output of the arm sensor 54 and the plowing depth setting dial 56 Whether the output of the arm sensor 54 corresponds to the output of the tilling depth setting dial 56 based on the output and the correlation data for setting the control reference value corresponding to those outputs (the dead zone of the output of the tilling depth setting dial 56) Whether it is within the width) or not. When the output of the arm sensor 54 corresponds to the output of the tilling depth setting dial 56, the fuel injection amount output by the injection amount calculating means 20C at this time is the control reference value in the load tilling depth control (see FIG. 8). As a reference value storage means 25C provided in the main ECU 25. Further, based on the stored control reference value and the fuel injection amount output by the injection amount calculation means 20C, the control target plowing depth of the rotary tiller 3 that is the output of the plowing depth setting dial 56 is corrected. Then, the operation of the lifting drive means 41 is controlled so that the output of the arm sensor 54 corresponds to the output of the corrected control target tilling depth (contains within the dead zone width of the corrected control target tilling depth) (FIG. 7).

  The correlation data for setting the control reference value is a map in which the output of the tilling depth setting dial 56 is used as the control target working depth of the rotary tiller 3 and the output of the arm sensor 54 is used as the working depth of the rotary tiller 3. Data or relational expressions.

  That is, in the load plowing depth control, when the load applied to the rotary plowing device 3 fluctuates together with the plowing depth of the rotary plowing device 3 due to the pitching of the tractor 1, the fuel injection amount fluctuates along with the engine load. By utilizing this, the control target tilling depth of the rotary tiller 3 is corrected based on the variation of the fuel injection amount, and the rotary tiller 3 is raised and lowered based on the corrected control target tilling depth.

  Accordingly, the field can be plowed at the plowing depth set by the plowing depth setting dial 56 regardless of the output of the cover sensor 53. As a result, when performing paddy roughing work or internal plowing work performed with the cover sensor 53 greatly lifted, by selecting load plowing depth control, the plowing depth setting is performed regardless of the pitching of the tractor 1 or the like. The field can be cultivated at the cultivating depth set by the dial 56. In addition, when a plow or the like that is not equipped with a grounding sensor such as the cover sensor 53 is connected to the tractor 1 in place of the rotary tiller 3, the tilling set by the tilling depth setting dial 56 regardless of the pitching of the tractor 1 or the like. Farms can be cultivated at depth.

  Note that a momentary switch is employed as the selection switch 61 for plowing depth control. As the reference value storage means 25C, a nonvolatile memory such as an EEPROM or a volatile memory such as a DRAM can be employed.

  As shown in FIG. 2, the main ECU 25 is provided with a change amount calculation means 25D. The change amount calculation means 25D is based on the threshold value for preventing engine stall and the fuel injection amount output by the injection amount calculation means 20C of the engine ECU 20, and the change amount of the fuel injection amount with respect to the threshold value (hereinafter abbreviated as the first change amount). ) Is calculated. Further, based on the control reference value stored in the reference value storage means 25C and the fuel injection amount output by the injection amount calculation means 20C of the engine ECU 20, the change amount of the fuel injection amount with respect to the control reference value (hereinafter referred to as the second change amount). Abbreviated). Further, based on the fuel injection amount output by the injection amount calculation means 20C, a change amount (hereinafter, abbreviated as a third change amount) of the fuel injection amount at a set time (for example, 200 ms) is calculated.

  As shown in FIGS. 4 and 5, the lift control means 25A reads the fuel injection amount output from the injection amount calculation means 20C as an index for preventing engine stall in the cover plowing depth control. Further, in the stall prevention control, the first change amount and the third change amount output by the change amount calculation means 25D are corrected with respect to the control target plowing depth (output of the plowing depth setting dial 56) of the rotary tiller 3 in the stall prevention control. Read as an index to set the amount.

  In the stall prevention control, the first change amount and the third change amount calculated by the change amount calculating means 25D and the correction amount for the control target plowing depth of the rotary tiller 3 are associated with the engine stall prevention control. Based on the correlation data, the control target tilling depth (output of the tilling depth setting dial 56) of the rotary tiller 3 is corrected to the shallow side. Then, based on the corrected control target plowing depth and the output of the cover sensor 53, the output of the cover sensor 53 corresponds to the corrected control target plowing depth (contains within the dead zone width of the corrected control target plowing depth). Thus, the operation of the drive means 41 for raising and lowering is controlled to raise the rotary tiller 3.

  The correlation data for the engine stall prevention control includes the first change amount and the third change amount output by the change amount calculation means 25D when the fuel injection amount exceeds the threshold, these two elements, and the rotary tiller 3 A two-dimensional fuzzy map showing the relationship with the correction amount for the control target tillage depth is adopted.

  In the fuzzy map for engine stall prevention control, the correction amount for correcting the control target tilling depth of the rotary tiller 3 to the shallow side is based on the first change amount and the third change amount. If the first change amount is large, the first change amount is increased accordingly. If the first change amount is considerably large, the third change amount is increased. If the injection amount decrease side is considerably large, it is considerably reduced. If the third change amount is large on the fuel injection amount decrease side, it is reduced accordingly. If the third change amount is small on the fuel injection amount decrease side, Accordingly, if the third change amount is small on the increase side of the fuel injection amount, it is increased slightly, and if the third change amount is large on the increase side of the fuel injection amount, it is set accordingly. Meet Increase Te, is set as the third variation is quite large accordingly be quite large in the increase of the fuel injection amount.

  That is, in the engine stall prevention control, the control of the rotary tiller 3 is controlled based on the change amount of the fuel injection amount with respect to the threshold when the fuel injection amount exceeds the threshold and the tendency of the change by the fuzzy map for the engine stall prevention control. Adjusting the correction amount for correcting the target tilling side to the upside, and controlling the operation of the drive means 41 for lifting based on the control target tilling depth of the rotary tiller 3 corrected to the upside by the correction amount after this adjustment By doing so, the rotary tiller 3 is raised.

  As a result, the rear wheels 5L and 5R and the rotary tiller 3 enter into a deep dent during work running in which isochronous control is performed to maintain the engine speed at the set speed by the accelerator lever 23, and the soil quality of the field is reduced. Even when the load applied to the rotary tiller 3 suddenly increases and may cause engine stall due to sudden hardening, based on the fuel injection amount that increases as the load increases. As the rotary tiller 3 is raised, the load on the engine 6 can be reduced, and the engine stall can be prevented.

  As shown in FIG. 5, in the load plow control, the lift control means 25A reads the fuel injection amount output from the injection amount calculation means 20C as an index for load plow control, and the change amount calculation means 25D outputs The second change amount and the third change amount are read as an index for setting a correction amount for the control target plowing depth (output of the plowing depth setting dial 56) of the rotary plowing device 3 in the load plowing depth control. Moreover, based on the correlation data for load plowing depth control in which the read second change amount and the third change amount, and these change amounts and the correction amount for the control target plowing depth of the rotary tiller 3 are associated with each other. The control target tilling depth of the rotary tiller 3 is corrected. Then, based on the corrected control target plowing depth and the output of the arm sensor 54, the output of the arm sensor 54 corresponds to the corrected control target plowing depth (contains within the dead zone width of the corrected control target plowing depth). ), The operation of the drive means 41 for raising and lowering is controlled to raise and lower the rotary tiller 3.

  The correlation data for load plowing depth control includes the second change amount and the third change amount output from the change amount calculating means 25D, the two elements, and the correction amount for the control target plowing depth of the rotary tiller 3 A two-dimensional fuzzy map showing the relationship is used.

  And in this fuzzy map for load plowing depth control, the second change amount is zero based on the second change amount and the third change amount, and the correction amount for the control plowing depth of the rotary tiller 3 is If the third change amount is zero, it is zero. Further, if the second change amount is slightly larger than the control reference value, the control target plowing depth is corrected to be slightly larger and shallower accordingly. If the second change amount is larger than the control reference value, Accordingly, the control target plowing depth is corrected to a large and shallow side, and if the second change amount is considerably large on the side exceeding the control reference value, the control target plowing depth is corrected to a large and shallow side accordingly. Conversely, if the second change amount is a little larger than the control reference value, the control target plowing depth is corrected to a slightly deeper side accordingly, and the second change amount is the control reference value. If it is larger than the value, the control target tilling depth is corrected to a large deep side accordingly. If the second change amount is considerably large below the control reference value, the control target tilling depth is considerably increased accordingly. Deep side On the other hand, if the third change amount is considerably large on the decrease side of the fuel injection amount, it is considerably reduced accordingly, and if the third change amount is large on the decrease side of the fuel injection amount. If the third change amount is small on the increase side of the fuel injection amount, conversely, if the third change amount is small on the decrease side of the fuel injection amount, it is set to be a little smaller. If the third change amount is large on the increase side of the fuel injection amount, it is increased accordingly, and if the third change amount is considerably large on the increase side of the fuel injection amount, it is set to be considerably large accordingly. It is.

  That is, in this load plowing depth control, the control target plowing depth of the rotary plowing device 3 is corrected based on the change amount of the fuel injection amount with respect to the control reference value and the tendency of the change by the fuzzy map for load plowing depth control. The rotary tiller 3 is lifted and lowered by controlling the operation of the drive means 41 for lifting and lowering based on the control target tilling depth of the rotary tiller 3 corrected with the correction amount after adjusting the correction amount appropriately. I am trying to make it.

  As a result, the fuel injection amount that fluctuates with the engine load according to the tillage depth of the rotary tiller 3 even during work travel in which isochronous control is performed to maintain the engine speed at the set speed by the accelerator lever 23. Based on this, the rotary tiller 3 moves up and down, so that the field can be cultivated with the tilling depth set by the tilling depth setting dial 57.

  In addition, when the load on the rotary tiller 3 is increased due to sudden hardening of the soil quality in the field, the rotary tiller 3 is lifted based on the fuel injection amount that increases accordingly, and the load is reduced. By doing so, work loss due to slipping or the like can be avoided.

  The calculation means 62 is configured by the injection amount calculation means 20C of the engine ECU 20 and the change amount calculation means 25D of the main ECU 25. Various correlation data, engine stall prevention threshold values, and the like are stored in basic data storage means 25E provided in the main ECU 25. The basic data storage means 25E employs a nonvolatile memory such as an EEPROM.

    [Another embodiment]

[1] The traveling vehicle body 1 may be provided with a pair of left and right crawler type traveling devices instead of the left and right rear wheels 5L and 5R, and the left and right front wheels 4L and 4R and the rear wheels 5L and 5R. Instead, a pair of left and right crawler type traveling devices may be provided.

[2] The engine 6 may be an electronically controlled distribution type diesel engine or an electronically controlled gasoline engine. Further, an apparatus that performs isochronous control by an electronically controlled or mechanically controlled governor, or that that does not perform isochronous control may be used. Further, based on the output of the accelerator pedal sensor 22 that detects the amount of depression of the accelerator pedal (an example of an accelerator operating tool) 21, the output rotation speed of the engine 6 corresponds to the operation position of the accelerator pedal 21. It may be configured to perform isochronous control that maintains the number.

[3] The setting means 56 may be a lever type or a switch type.

[4] The detecting means 53 includes a dedicated grounding body mounted on the rotary tiller 3 so as to be displaced according to the tillage depth of the rotary tiller 3, and a potentiometer for detecting the displacement of the grounding body. It may be a thing. Further, it may be configured to be non-grounded by an ultrasonic sensor or the like.

[5] The calculating means 62 is composed of an injection amount calculating means 20C of the engine ECU 20 and a change amount calculating means 25D of the main ECU 25, and the change amount calculating means 25D outputs the threshold value for preventing engine stall and the injection amount calculating means 20C. Based on the fuel injection amount to be calculated, only the change amount (first change amount) of the fuel injection amount with respect to the threshold value is calculated, and the control means (elevation control means) 25A calculates the first change amount calculated by the change amount calculation means 25D. Based on the correlation data for the engine stall prevention control in which the first change amount and the correction amount for the control target plowing depth of the rotary tiller 3 are associated, the control target plowing depth of the rotary tiller 3 is corrected to the shallow side. Based on the corrected control target tilling depth and the output of the detecting means (cover sensor) 53, the output of the detecting means 53 corresponds to the corrected control target tilling depth (the corrected control target). By moving the rotary tiller 3 by controlling the operation of the drive means 41 for raising and lowering so that it falls within the deep dead zone width, the soil quality of the field becomes stiff and hard. You may comprise so that generation | occurrence | production of the engine stall resulting from may be prevented.

[6] The calculating means 62 is constituted by the load factor calculating means 20D of the engine ECU 20 and the change amount calculating means 25D of the main ECU 25, and the change amount calculating means 25D outputs the threshold value for preventing engine stall and the load factor calculating means 20D. Based on the load factor to be calculated, a change amount of the load factor with respect to the threshold value (hereinafter referred to as a fourth change amount) is calculated, and the control means (elevation control means) 25A calculates the fourth change calculated by the change amount calculation means 25D. The control target plowing depth of the rotary tiller 3 is corrected based on the correlation data for the engine stall prevention control in which the amount, the fourth change amount and the correction amount for the control target plowing depth of the rotary tiller 3 are associated with each other. Based on the corrected control target plowing depth and the output of the detection means (cover sensor) 53, the output of the detection means 53 corresponds to the corrected control target plowing depth (the corrected control target plowing depth). Due to the fact that the rotary tiller 3 is lifted by controlling the operation of the drive means 41 for raising and lowering so that it falls within the dead zone width, the deep soil is suddenly hardened by entering into a deep depression You may comprise so that generation | occurrence | production of an engine stall may be prevented.

  For the load factor, a ratio of the actual intake amount to the reference maximum intake amount per rotation of the engine 6 calculated based on the intake pressure and the engine speed can be adopted.

[7] The calculating means 62 is constituted by the load factor calculating means 20D of the engine ECU 20 and the change amount calculating means 25D of the main ECU 25, and the change amount calculating means 25D outputs the threshold value for preventing engine stall and the load factor calculating means 20D. Based on the load factor to be calculated, the amount of change in the load factor with respect to the threshold value (hereinafter abbreviated as the fourth change amount) is calculated, and the set time (for example, 200 ms) based on the load factor output by the load factor calculating means 20D The amount of change in the load factor (hereinafter abbreviated as the fifth change amount) is calculated, and the control means (elevation control means) 25A calculates the fourth change amount and the fifth change amount calculated by the change amount calculation means 25D, And based on the correlation data for the engine stall prevention control in which the amount of change and the correction amount for the control target plowing depth of the rotary plowing device 3 correspond, the control target plowing of the rotary plowing device 3 , And the output of the detecting means 53 corresponds to the corrected control target tilling depth based on the corrected control target tilling depth and the output of the detecting means (cover sensor) 53 (the corrected control target tilling depth). Due to the fact that the rotary tiller 3 is lifted by controlling the operation of the drive means 41 for raising and lowering so that it falls within the dead zone width, the deep soil is suddenly hardened by entering into a deep depression You may comprise so that generation | occurrence | production of an engine stall may be prevented.

  For the load factor, a ratio of the actual intake amount to the reference maximum intake amount per rotation of the engine 6 calculated based on the intake pressure and the engine speed can be adopted.

[8] The calculating means 62 may be configured to be provided in either the engine ECU 20 or the main ECU 25.

  INDUSTRIAL APPLICABILITY The present invention can be applied to a tilling work machine configured by connecting a rotary tiller device to a rear portion of a traveling vehicle body so as to be movable up and down.

DESCRIPTION OF SYMBOLS 1 Traveling vehicle body 3 Rotary tillage device 6 Engine 20B Isochronous control means 21 Accelerator operating tool (accelerator pedal)
23 Accelerator (Accelerator lever)
25A Control means 41 Drive means 53 Detection means 56 Setting means 62 Calculation means

Claims (3)

A rotary tiller is connected to the rear part of the vehicle body with the engine so that it can be raised and lowered.
Drive means for driving the rotary tiller up and down;
Setting means for setting a control target tillage depth of the rotary tiller,
Detecting means for detecting a tilling depth of the rotary tilling device;
Based on the output of the setting means and the output of the detection means, the tilling depth of a tilling work machine provided with a control means for controlling the operation of the drive means so that the output of the detection means corresponds to the output of the setting means A control structure,
Computation means for computing the fuel injection amount or load factor of the engine,
The control means corrects the control target working depth to a shallow side based on the output of the calculation means and the threshold when the output of the calculation means exceeds a threshold for preventing engine stall, and the control after correction Based on the target tilling depth and the output of the detecting means, the operation of the driving means is controlled so that the output of the detecting means corresponds to the corrected control target tilling depth. Control structure.   The traveling vehicle body is provided with isochronous control means for maintaining the output rotational speed of the engine at a control target rotational speed corresponding to the operating position of the accelerator operating tool by adjusting a fuel injection amount based on the load of the engine. The tilling depth control structure for a tilling work machine according to claim 1, wherein the tilling depth controlling structure is provided. The calculation means calculates a change amount of the fuel injection amount or the load factor with respect to the threshold value and a change amount of the fuel injection amount or the load factor at a set time,
The tilling depth control structure for a tilling work machine according to claim 1 or 2, wherein the control means corrects the control target tilling depth based on two variations.

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