JPS63119616A - Car speed controller of harvester - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vehicle speed control device for a harvester that increases or decreases the traveling speed in accordance with an increase or decrease in load on working sections such as a threshing section or a reaping section.

[Prior art]

The harvesting machine transports the culm harvested in the reaping section to the threshing section, and the threshing section performs threshing and sorting to take out fine grains. The load on each section increases or decreases depending on the amount of shell culms to be processed, while the amount of shell culms to be processed increases or decreases depending on the traveling speed of the harvester, field conditions, etc. Therefore, conventional harvesters are equipped with a vehicle speed control device that changes the running speed of the harvester according to increases and decreases in the load on the working section so that the working section is always operated under an appropriate load condition. There is something.

For example, this vehicle speed control device detects the load on the working section based on the rotation speed of the handling drum of the threshing section, and if this detected value exceeds a preset appropriate range, the amount of husks to be processed in the working section is In order to reduce the load on the working part, the traveling speed is reduced by a predetermined amount, and if the detected value is below the appropriate range and there is enough room for the engine that drives the working part, the work Increasing the amount of shell culm to be processed in the
In order to increase the load on the working part, the traveling speed is increased by a predetermined amount, and the increase or decrease in the traveling speed is done by changing the traveling speed adjustment position of the transmission (Japanese Patent Application No. 60-16
No. 8707).

[Problem that the invention seeks to solve]

In this way, conventional vehicle speed control devices reduce the traveling speed until the rotation speed of the handling cylinder increases or decreases depending on the load on the working part and falls outside the appropriate range. Since the rotation speed is changed in stages, if the detected value of the rotation speed deviates significantly from the appropriate range and multiple gear changes are required to return it to the appropriate range, the specified amount of the -degree running speed may be changed. After making the change, the load on the working part increases or decreases according to this speed, waits until it stabilizes, and then changes the next traveling speed according to the detected value of the rotation speed of the handling cylinder after stabilizing. Therefore, it takes a considerable amount of time to change the traveling speed, and during this time the work section performs various processes under overload or underload conditions, and the engine driving the work section is overloaded. The problem was that they were forced to drive at the same time or their work efficiency was reduced.

In order to solve this problem, if the amount of change in the running speed is increased - times, for example, if the detected value of the rotation speed of the handling cylinder exceeds the appropriate range and the running speed is decelerated, the speed after deceleration will be There is a risk that the load on the working section in response to this may fall below the appropriate range, causing the traveling speed to increase and then repeating the increase and deceleration, resulting in so-called hunting.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a vehicle speed control device for a WI machine that can immediately increase or decrease the traveling speed to an appropriate speed in accordance with the detected value of the load on the working section. purpose.

[Means for solving problems]

The vehicle speed control device for a harvester according to the present invention includes an engine rotation speed control section that operates to maintain the engine rotation speed at a set rotation speed regardless of the magnitude of the load, and the engine speed control section operates to maintain the engine rotation speed at a set rotation speed regardless of the magnitude of the load. A vehicle speed control device for a harvesting machine, which is provided in a harvester configured to drive and controls the running speed by changing the running speed adjustment position of a transmission according to the load on the working unit. A load detection means for detecting the load of the engine related to the load, a position detection means for detecting the travel speed adjustment position, and a relationship between the engine load and the travel speed at each of the travel speed adjustment positions are determined by the operation. a characteristic storage means for storing a plurality of load characteristics in the form of a plurality of load characteristics corresponding to the load state in the section; and a characteristic storage means for storing one of the plurality of load characteristics from the detection results of the load detection means and the position detection means; The vehicle is characterized by comprising means for calculating an expected engine load at each of the travel speed adjustment positions according to the calculation result, and changing the travel speed adjustment position based on the calculation result.

(Function) In the present invention, the load on the working section is detected as the load on the engine, and the traveling speed is detected as the traveling speed adjustment position of the transmission, so that the load characteristic corresponding to the current state of the load on the working section can be determined as described above. The engine load at each traveling speed adjustment position is selected from the contents stored in the characteristic storage means, and the engine load at each traveling speed adjustment position is calculated according to the characteristic, and the traveling speed adjustment position is changed so that an appropriate load state is obtained in the engine, Speed control is provided.

〔Example〕

The present invention will be explained below based on the drawings showing practical examples thereof. FIG. 1 is an external perspective view of a vehicle speed control device equipped with a vehicle speed control device according to the present invention (hereinafter referred to as the device of the present invention).
In the figure, reference numeral 1 indicates a running roller, and the driving force of the engine (not shown) is the main clutch, the gear mesh type sub-transmission device,
The information is transmitted to the main transmission using a power shift transmission and further to the running rollers 1 through a side clutch to cause the machine to run. A swing sorting device (both not shown), a cutting blade 41.degree. pulling device 42, etc. installed in the cutting section 4 at the front of the machine are also driven by the driving force of the engine.

Reference numeral 6 in the figure is an operation column provided on the side of the driver's seat DS, and this operation column 6 includes a main shift lever 51. A sub-shift lever 52 that changes the traveling speed stage of the sub-transmission device. An accelerator lever 53 for changing the rotational speed of the engine, an automatic switch 9 for instructing the device of the present invention to start its operation, and the like are provided.

Reference numeral 7 denotes a vertical conveyance chain, the terminal end of which faces the starting end of the feed chain 81 of the culm gripping conveyance device 8 provided along the handling barrel on the left side of the threshing device 3, The culm harvested in step 4 is transferred to the vertical conveyance chain 7 and the feed chain 81 and gripping rod 8 of the culm gripping and conveying device 8.
2, and is threshed inside the threshing section 3.

A shell culm sensor 71 is installed on the front surface of the threshing section 3 near the terminal end of the straw conveyor chain 7, and the shell culm sensor 71
The detection rod 72 protruding downward is brought into contact with a part of the shell culm conveyed by the vertical conveyance chain 7, and the threshing section 3
It is detected that the culm is being fed to the culm.

FIG. 2 is a block diagram showing the configuration of the apparatus of the present invention. In the figure, 10 is a vehicle speed control section, and 30 is an engine rotation speed control section. The vehicle speed control by the device of the present invention is possible only in a harvester equipped with an engine that can rotate at a constant speed regardless of the magnitude of the load, and the engine speed control unit 30
The engine speed controller 30 performs so-called isochronous control in which the engine speed is detected and the amount of fuel supplied to the engine is controlled so that the detected engine speed matches the set speed. The control details will be briefly explained.

On the input side of the engine speed control unit 30, for example, a differential transformer is installed on a fuel rack (hereinafter referred to as rack) of a fuel injection pump (not shown) attached to the engine and detects the position of the rack. A rank position sensor 31 using the engine and an engine rotation sensor 32 mounted on the engine to detect the rotation speed of the engine are connected, and the output of the engine rotation speed control section 30 is connected to the engine rotation sensor 31 using the engine.
A rack actuator 33 that uses a near solenoid, for example, and a vehicle speed control section 10 that will be described later.
The input capo) as is given respectively.

The engine rotation speed control unit 30 includes a numerical table or arithmetic formula for determining the corrected set rotation speed to be set in order to return the rotation speed to the set rotation speed when the detected rotation speed differs from the set rotation speed due to a change in load, and the engine Numerical table or calculation formula for determining the relationship between the corrected set rotation speed at no-load and the rank position where this can be obtained, that is, the no-load equivalent position, and the no-load equivalent rank position and detection A numerical table or calculation formula for determining the rank position required to obtain the set rotation speed from the rack position, that is, the target rack position, and the maximum permissible position of the rank at each rotation speed are stored.

Then, the engine speed control unit 30 calculates a corrected set speed when the detected speed input from the engine speed sensor 32 differs from the set speed (in this case, the rated speed) due to a change in the load. , reads the no-load equivalent rank position corresponding to the corrected set rotation speed, calculates the target rack position from the read no-load equivalent rack position and the actual rack position, and generates a signal for moving the rack to this target rack position. is issued to the rack actuator 33. In response to this signal, the rack actuator 33
It operates to move the rank to the target rank position and adjusts the amount of fuel supplied to the engine.

In this manner, the engine rotation speed control section 30 causes the engine to rotate at a constant speed at the rated rotation speed of the engine, regardless of the magnitude of the load.

On the other hand, input ports a1 to a4 of the vehicle speed control section 10 are given signals for causing the control section 10 to start its operation. The automatic switch 9 is installed in the input capo-1-a1.
is maintained, and when the switch 9 is turned on, the input port a1 changes to a low level. Also human capo-1”a2+
83+at includes a threshing switch 11. which is turned on when the threshing clutch is engaged. A reaping switch 12 that is turned on when the reaping latch is engaged and a culm switch 13 that is turned on when the culm comes into contact with the detection rod 72 of the culm sensor 71 are connected to each other. When the switch is turned on, the input capo) a2+ 83. a
t respectively turn to a high level. Then, the vehicle speed control unit 10 controls the speed control unit 10 when each of the switches is turned on, that is, when the input port is turned on.
)at is low level, input port a2+a3+
It operates only when both at are at high level to control the vehicle speed of the harvester.

The input capo 1''a5+ aa of the vehicle speed control unit 10 has first and second sub-shifts that are disposed at the base end of the sub-shift lever 52 and are turned on and off depending on the locking position of the acid lever 52. Switches 14 and 15 are connected, and when the first sub-shift switch 14 is turned on, the input port a5 is turned on, and when the second sub-shift switch 15 is turned on, the input port aa is turned to low level. The auxiliary transmission is "low gear", "
The first sub-shift switch 14 is connected to the sub-shift lever 5.
2 is in the locking position corresponding to the above-mentioned "low gear",
Further, the second auxiliary shift switch 15 is arranged to be turned on when the auxiliary shift lever 52 is in the locking position corresponding to the "high gear", and the vehicle speed control unit 10 is connected to the input port. When a5 is at a low level, it is determined that the traveling speed gear of the sub-transmission device is a "low gear", and when input capo aa is at a low level, it is determined that the traveling speed gear of the sub-transmission device is a "high gear". , and further input boat as + aa
Since both are at a high level, the same "middle gear"
Each of us recognizes that.

A shift sensor 16 using a potentiometer is connected to the input capacitor (at) of the vehicle speed control unit 10, which is attached to the base end pivot portion of the main shift lever 51 and outputs a potential according to the amount of rotation thereof. has been done. The main transmission has six speed stages: four forward speeds, one reverse speed, and neutral, and the vehicle speed control unit 10 adjusts the speed according to the level of the output signal of the shift sensor 16 input to the input port a7. , recognizes which state the traveling speed stage of the main transmission is in;

A signal corresponding to the target rank position, which is the output of the engine speed control section 30, is provided to the input boat a of the vehicle speed control section IO.

Human powered boat a7. The signals input to as are subjected to predetermined processing at the input interface of the vehicle speed control section 10, and are taken into the CPII 10a of the vehicle speed control section IO as digital data according to the level of each signal.

On the other hand, the output port b1 of the vehicle speed control section 10. b2 is connected to the shift motor 20 for rotating the main shift lever 51 via a drive circuit (not shown), and when the output capo) bt (or the same bz) becomes a high level, the shift motor 20 rotates normally (or (reverse rotation), and the main shift lever 51 is rotated toward the high speed (or low speed) travel side.

The output port b3 of the vehicle speed control section 10 is connected to the vehicle speed lamp 21 for notifying the operator that vehicle speed control is being performed, and the output port b+ and the same are connected to the sub-shift lever 5.
The output capo b3. b4. When b5 becomes low level, each of the lamps is turned on.

The output port b6 of the vehicle speed control unit IO is connected to a buzzer 24 for outputting various warnings, and the buzzer 24 sounds when the output port b6 becomes high level.

Further, the output port b7 of the vehicle speed control unit 1O is connected to the input side of the engine speed control unit 30, and when the output port b7 becomes high level, the input port of the engine speed control unit 30 connected thereto When reaches a high level,
The control unit 30 starts its operation,
While the output port b7 is at a high level, the engine of the harvester rotates at a constant speed at the rated speed, regardless of the magnitude of the load, due to the operation of the engine speed control section 30 as described above.

The vehicle speed control unit 10 is a CP that performs input/output instructions and control calculations.
It is composed of a ROM 10c used for control calculations of U 10a and CPLI 10a, and a ROM 10c storing various data and control programs necessary for control calculations. Figure 3 is a graph of load characteristics showing the relationship between the running speed of the harvester and the engine load when the engine rotation speed is the rated rotation speed, where the horizontal axis is the running speed and the vertical axis is the running speed. is the load factor E for the maximum engine load
It is.

Now, even if the traveling speed of the harvester is constant, the threshing section 3. The load on the working parts such as the reaping part 4 varies depending on the work conditions such as the planar density of the culm to be harvested on the field surface and the number of grains attached to the culm. ~Fn
The curve shown as is a load characteristic curve obtained by actually carrying out harvesting operations under various working conditions. Further, since the engine rotates at a constant speed, the traveling speed of the harvester is determined by the traveling speed stage of the main transmission and the auxiliary transmission. \L1 to L4 in Figure 3. Ml to M4 and old.

H2 is a code indicating the traveling speed stage, and L.

1, 2. M and H indicate that the running speed gears in the sub-transmission device are the "low gear", "middle gear", and "high gear", respectively. 3. 4, the traveling speed stages in the main transmission are "1st forward speed" and "2nd forward speed", respectively.

This indicates that the vehicle is in "3rd forward speed" or "4th forward speed."

In addition, the curve shown as ΔE in FIG. 3 is a load fluctuation curve showing the amount of load fluctuation at each speed, and also
x is the limit maximum load rate for limiting the load applied to the engine to below this value during vehicle speed control, and is 85 to 90%.
is set to .

Now, F1 to Fn and ΔE shown in FIG.
is stored in In addition to these, the ROM 10c also stores the load factor E from the rank position of the fuel injection pump.
Various data such as calculation formulas for calculating.

Numerical formulas etc. are memorized.

Now, the operation of the apparatus of the present invention constructed as described above will be explained based on a flowchart showing the control contents of the vehicle speed control section 10 shown in FIG.

The vehicle speed control unit 10 satisfies the control start conditions, which are that the threshing unit 3 and the reaping unit 4 are both operating, that the husk is being fed to the threshing unit 3, and that the automatic switch 9 is turned on. The vehicle speed control operation is performed only when it is confirmed by the levels of the input ports a+ to a4 that all the conditions are satisfied as described above.

When each of the above conditions is satisfied, the vehicle speed control section 10 first sets its output port b3 to a low level and lights up the vehicle speed lamp 21 to inform the operator that vehicle speed control is being performed, and also outputs the output port By setting b7 to a high level, the engine rotation speed control section 30 is commanded to start its operation. From then on, the engine of the harvester rotates at a constant speed at its rated rotation speed due to the operation of the engine rotation speed control unit 30.

Next, the vehicle speed control unit 10 determines the rank position R from the signal input to the input port a6, and determines the running speed gear (hereinafter referred to as the main shift position) A in the main transmission from the signal input to the input port a7. Furthermore, input boat a5. Depending on the level of a6, the traveling speed stage (
(hereinafter referred to as the sub-shift position)B. Then, using the rank position R, the input load factor ε is calculated according to the arithmetic expression stored in the ROM 10c. The input load factor C calculated in this way may be used as is for subsequent calculations, but in an engine that is isochronously controlled,
Since the rack position is frequently changed, in order to prevent vehicle speed control from being performed based on the instantaneous peak value of the rank position R, the input load factor ε calculated as described above is used in subsequent calculations. It is desirable to use a moving average value of .

Next, the vehicle speed control unit 10 stores the input load factor ε in the ROM 10.
When ε is less than or equal to E cmax, the subsequent processing shifts to the speed increase control subroutine D, which will be described later.

In addition, if ε is larger than Ecmax and deceleration is required, first check whether the main shift position A is 1, that is, whether the main shift position is the "first forward gear". If 8 is not 1 and the traveling speed can be reduced by changing the main shift position, the output boat b2 is set at a high level for a predetermined period of time, the shift motor 20 is reversed by a predetermined amount, Decrease running speed.

Further, if A is 1 and the traveling speed cannot be reduced by changing the main shift position, the vehicle speed control unit 10 next determines whether or not the sub-shift position B is set. Check whether it is in the "low gear" or not, and if B is not,
If it is possible to reduce the traveling speed by changing the sub-shift position, output capo b5 is set to low level, the deceleration instruction lamp 23 is turned on, and the operator operates the sub-shift lever 52 to the deceleration side. instruct. Thereafter, the vehicle speed control section 10 controls the input capo) a5. By monitoring changes in the level of a6, it is determined whether or not the sub-shift lever 52 has been operated, and if the operation has not been performed, the output/'J boat b6 is set to a high level and the buzzer 24 is sounded. After waiting for a predetermined time (71 seconds), the same operation is repeated. That is, if the operator misses the illumination of the deceleration instruction lamp 23 and does not operate the sub-shift lever 52, the buzzer 24 is intermittently activated at time intervals of T15ec until the sub-shift lever 52 is operated. Make the lever 52 ring and ask the operator to move it.
instruct the operation. Then, the sub-shift lever 52 is operated,
When it is confirmed that the traveling speed has been reduced by changing the sub-shift position, the vehicle speed control section 10 changes the output boat b5 to a high level and turns off the deceleration instruction lamp 23.

In this way, the reverse rotation of the shift motor 20 or the sub-shift lever 52
After decelerating the traveling speed by operating the vehicle speed control unit 10
is the time required for the load on the threshing section 3 to decrease in accordance with the changed traveling speed, in other words, the time required for the husk cut by the reaping section 4 to be transported to the threshing section 3. Waiting for a predetermined time (72 seconds) set in anticipation, and then checking whether the control start condition is satisfied.
If satisfied, return to the beginning of the flowchart and repeat the operations described above. Furthermore, if the condition is not satisfied, the vehicle speed control operation is suspended until the condition is satisfied again.

Furthermore, when it is checked whether or not the sub-shift position B is set first, if B is L and the traveling speed cannot be reduced by changing the sub-shift position, the vehicle speed control unit 10 ,
The output boat b2 was set to a high level, the shift motor 20 was continuously reversed until the main gear shift position became the neutral position, the traveling of the aircraft was stopped, and the output boat b6 was then set to a high level and the buzzer 24 sounded. rear,
Stops vehicle speed control operation. This is threshing section 3. An excessive load is being applied to any part of the working parts such as the reaping part 4. In this case, the operator should temporarily stop the engine, inspect each part, and remove the cause of the excessive load. After that, by restarting the engine, the vehicle speed control unit 10
returns to its original state.

Now, FIG. 5 is a flowchart of the speed increase control subroutine D. First limit the input load factor εmaximum load factor E cm
If the result of comparison with ax is that ε is less than Ectaax, the vehicle speed control unit 10 shifts the subsequent processing to speed increase control subroutine D. In subroutine D, first one of the plurality of load characteristic curves F1 to Fn stored in the ROM 10c is selected based on the previously calculated input load factor C and the previously recognized main shift position A and sub-shift position B. , a load characteristic curve Fi matching the current load condition is selected. For example, when the main shift position A is 3 and the sub shift position B is M, the current load condition is specified at point C on the graph showing the load characteristics in FIG. A characteristic curve designated as Fi is selected. Also, the load characteristic curve F1~
If there is no match among Fn, two load characteristic curves Fi and Fi+"l that are close to the load condition are selected, and the calculations described below performed based on these curves are based on the curves Fi and Linear interpolation is performed between the curve F1+1 and the curve F1+1.

Then, the vehicle speed control unit 10 selects a register a indicating the main shift position.
2. Set register b indicating the sub-shift position to H, then compare sub-shift position B with the contents of register b and main shift position A with the contents of register a, and find that B=b and A= If it is a, the control operation according to the speed increase control subroutine D is ended without increasing the traveling speed.

In addition, if B≠b or A#a, the load factor Ei on the load characteristic curve Fi when the main shift position is a and the auxiliary shift position is b, and the load fluctuation curve at that time. Calculate the load fluctuation amount ΔEi on ΔE,
Next, Ei +ΔEi and the limited maximum load factor E cma
Compare with x. And Ei + ΔEi is E cmax
If the above is the case, next check the contents of register a, and a
If is 1, the contents of register b are updated one step to the low speed side, and a is set to 4. If a is not 1, the contents of register a are updated one step to the low speed side, and then again. The process returns to the step of comparing the sub-shift position B with the contents of register b and the main shift position A with the contents of register a, and repeats the above-described operations. The contents of the register are updated in register a by subtracting 1 from the contents, and in register b, if the contents are H, it is changed to M, and if the contents are M, the contents are changed to M. is done by setting this to L.

On the other hand, if Ei +ΔEi is smaller than E cmax, the vehicle speed control unit 10 performs speed increase control with the main shift position set to a and the sub-shift position set to b. That is, it is first checked whether b matches the current sub-shift position B, and if they match and there is no need to change the sub-shift position,
The output port b1 is set to high level, and the main gear shift position is set to a.
The shift motor 20 is rotated in the normal direction until it is confirmed by the input signal to the input port a7 that the travel speed is increased.

If b does not match B and it is necessary to change the sub-shift position, first set the output port b4 to low level, turn on the speed increase instruction lamp 22, and ask the operator to shift the sub-shift lever. 52 to the speed increasing side. After that, by monitoring the level of input ports a5+a6,
It is confirmed whether or not the sub-shift lever 52 has been operated until the sub-shift position is set to b, and if it has not been operated, the output port b6 is set to high level as in the case of the above-mentioned deceleration instruction, and the above-mentioned The buzzer 24 is made to sound intermittently at the time interval Tl5ec until the operation is performed. When the sub-shift lever 52 is operated and it is confirmed that the sub-shift position is set to b, the vehicle speed control unit 10 changes the output port b4 to a high level and turns off the speed increase instruction lamp 22. After that, as described above, in order to set the main shift position to a, the output port b1 is set to the high level, and the shift motor 20 is rotated in the normal direction. After the speed increase control is performed so that the main shift position is set to a and the sub-shift position is set to b in this way, the vehicle speed control unit 10 waits for a predetermined period of time T 2 'sea.
The control operation according to the speed increase control subroutine D ends.

The control operation of the vehicle speed control section 10 in the speed increase control subroutine D as described above will be specifically explained using an example in which the current load state is at the 0 point shown in FIG. In this case, as described above, the main shift position A is 3, the auxiliary shift position B is M, and the load characteristic curve Fi is selected at the first stage of the speed increase control subroutine D. Then, since a=2°b=H and Bib, the load factor Ei and the load fluctuation amount ΔEi on the load characteristic curve Fi at the traveling speed adjustment position H2, that is, at the highest speed position are calculated. Since Ei +ΔEi at this time is greater than Ecmax as is clear from Fig. 3, next a=
Since B≠b, 1. Traveling speed adjustment position H1
The load factor Ei and load fluctuation amount ΔEi are calculated,
Ei +ΔEi and E cmax are compared. As is clear from Fig. 3, Ei +ΔEi at this time is,
Since E cmax or more, then b=M and a=4, and since B=b but A#a, Ei and ΔEi between the travel speed adjustment positions are calculated. As shown in Fig. 3, Ei +ΔEi at this time is E cmax
Therefore, the vehicle speed control unit 10 operates so that the main shift position becomes 4 and the auxiliary shift position becomes M by subsequent operations, that is, to realize the old traveling speed gear, thereby increasing the traveling speed. let That is, in the speed increase control subroutine D,
From the current load state, the engine load factor at each traveling speed gear higher than the current traveling speed gear is calculated, and the vehicle speed control unit 10 calculates the calculation result as the limit maximum load factor E.
Under the condition that cmax is not exceeded, it operates to realize the highest allowable travel speed stage.

In addition, in the above example, E + ΔE at the earliest traveling speed
If the value of i is greater than or equal to E cmax, then a
=3, but in this case, B=b and A-a, so the control operation according to the speed increase control subroutine D ends without increasing the traveling speed. This is because the earliest current traveling speed is the aforementioned highest traveling speed stage, and there is no need to perform speed increase control.

Now, in this embodiment, when the input load factor ε exceeds the limit maximum load factor Ecmax, that is, when deceleration is necessary, the traveling speed stage is shifted to the deceleration side in stages as in the conventional case. configuration, but this has an E cmax of 8
This is because the load factor is set high at 5 to 90%, and during deceleration, it is possible to return to a load factor smaller than the E cmax by one step of deceleration in the main transmission or auxiliary transmission. It goes without saying that a deceleration control subroutine similar to speed control subroutine D may be provided.

Furthermore, in this embodiment, the auxiliary transmission is a manually operated type, but a power shift transmission similar to the main transmission may be used for this, or a hydrostatic transmission may be used for these. good.

Furthermore, in this embodiment, the load fluctuation amount ΔEt is added to the load factor Ei obtained from the graph showing the load characteristics, and Ei
Since speed increase control is performed to achieve a traveling speed stage in which +ΔEi does not exceed the limit maximum load factor E cmax, it is possible that the input load factor ε will exceed E cmax due to a short fluctuation in the load after speed increase. If this happens, there is little risk that unnecessary deceleration control will be performed due to this.

〔effect〕

As detailed above, in the device of the present invention, the travel speed adjustment position where an appropriate load can be obtained is determined from the engine load and the travel speed adjustment position, and the travel speed adjustment position of the transmission is changed to achieve this. Therefore, even if the load significantly deviates from the appropriate range, the vehicle speed is quickly changed to the appropriate running speed, improving work efficiency and preventing the engine from being overloaded for a long time. This has excellent effects, such as not being forced to drive at high speeds.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and Fig. 1 is an external perspective view of a harvester equipped with the device of the present invention, Fig. 2 is a block diagram showing the configuration of the device of the present invention, and Fig. 3 is a harvester equipped with the device of the present invention. Graphs showing the relationship between the running speed of the machine and the load of one engine, and FIGS. 4 and 5 are flowcharts of vehicle speed control.

Claims (1)

[Claims] 1. An engine rotation speed control section that operates to maintain the engine rotation speed at a set rotation speed regardless of the magnitude of the load;
The harvester is equipped with a harvester in which the engine drives the traveling part and the working part, and the harvesting machine controls the traveling speed by changing the traveling speed adjustment position of the transmission according to the load on the working part. In the vehicle speed control device, load detection means detects the load of the engine related to the load of the working section; position detection means detects the travel speed adjustment position; and the load of the engine and each of the travel speed adjustment positions. characteristic storage means for storing the relationship between the travel speed and the traveling speed in the form of a plurality of load characteristics according to the load state in the working section; Select one of them,
A vehicle speed control device for a harvester, comprising means for calculating an expected engine load at each of the traveling speed adjustment positions according to the characteristics, and changing the traveling speed adjustment position based on the calculation result. .