JP3305497B2 - Bulldozer blade controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for controlling a blade at the start of excavation or at the time of reverse running in a dozing operation using a bulldozer.

[0002]

2. Description of the Related Art Conventionally, a dozing operation using a bulldozer of this type switches a speed stage or changes a traveling direction by operating a shift lever or a steering lever by a manual operation of an operator who operates the bulldozer, and changes a blade control lever. The operation is performed by raising or lowering the blade by operating the blade, and further tilting the blade to the left or right.

[0003]

In such a manual dosing operation, when the operator attempts to start the excavation operation by setting the shift lever to the forward traveling position, the operator lowers the blade to the ground. When the blade is tilted left and right, it is necessary to perform a so-called tilt operation to make the lower end of the blade horizontal to the vehicle body. Further, when the dosing operation is completed and the shift lever is moved to the reverse position and the vehicle is to travel backward to the excavation point, the blade is once raised to the predetermined position, and then the blade is moved to the traveling posture (minimum ground clearance). ).

[0004] However, since the operation by the operator at the time of starting excavation or traveling backward as described above is an operation that is repeated many times, even a skilled operator operates the blade to move up and down or tilt. There is a problem that it is frequent and involves a great deal of fatigue. In particular, a tilting operation for leveling the blade is a task that requires the operator to use nerves because there is no target, and often causes fatigue. In addition, when the blade is raised to a predetermined height or more due to an erroneous operation by the operator during reverse running, there is also a risk of causing an accident due to the stability of the vehicle body caused by running the vehicle body in this raised state. is there.

SUMMARY OF THE INVENTION The present invention aims at solving such problems by reducing the operator's fatigue by omitting the operation that is repeatedly performed by the operator at the time of starting excavation or traveling backward. An object of the present invention is to provide a bulldozer blade control device capable of improving safety at the time.

[0006]

In order to achieve the above-mentioned object, the blade control device for a bulldozer according to the present invention can firstly (a) set the operation mode during dosing work to an automatic operation mode. Operation mode setting means,
(B) traveling state detecting means for detecting whether the transmission is in a forward traveling state or a reverse traveling state; and (c) the traveling state detecting means detects that the transmission is in a forward traveling state, and the driving mode At the start of excavation when the operation mode is set to the automatic operation mode by the setting means, the lower end of the blade is horizontal to the vehicle body and the tilting and lowering movements of the blade are controlled so that the lower end of the blade contacts the ground. And a blade control means.

Secondly, the bulldozer blade control device according to the present invention comprises: (a) an operation mode setting means capable of setting an operation mode during dosing work to an automatic operation mode; and (b) a transmission in a forward running state. Traveling state detecting means for detecting whether the vehicle is in the reverse traveling state or not; and (c) the traveling state detecting means detects that the transmission is in the reverse traveling state, and the driving mode setting means switches the driving mode to the automatic driving mode. When the setting is made, a blade control means is provided for controlling the raising or lowering of the blade so that the lower end of the blade is at a reverse traveling position in which the lower end is located a predetermined distance above the ground.

[0008]

According to the bulldozer blade control device having the first feature, when the transmission is detected to be in the forward running state, and when the operation mode is set to the automatic operation mode by the operation mode setting means, the excavation starts. The blade is tilted by the blade control means so that the lower end of the blade is horizontal to the vehicle body, and the blade is lowered so that the lower end of the blade comes into contact with the ground. Therefore, the operator can smoothly move the blade to a predetermined reference position at the start of excavation without a great deal of fatigue,
Dosing work can be performed efficiently.

In the present invention, it is preferable to provide a blade elevating / lowering means having a pair of hydraulic cylinders disposed between the left and right ends of the blade and the vehicle body, for example. It is preferable that the apparatus further comprises a blade position detecting means for detecting a vertical movement position and a tilt movement position of the blade.
Here, as the blade position detecting means, it is preferable to detect a vertical movement position and a tilt movement position of the blade by detecting a stroke amount of a pair of hydraulic cylinders in the blade lifting / lowering means.

Further, in the present invention, it is preferable to provide a blade inclining means for inclining the blade with respect to the vehicle body by raising or lowering the left and right ends of the blade. It is preferable to have one hydraulic cylinder disposed between one end and the vehicle body, and one brace disposed between the other end of the blade and the vehicle body.

The blade control means may control the blade so that the blade is moved downward after the blade is tilted, or the blade control means controls the blade so that the blade is tilted after the blade is moved downward. You may do it.

Further, in the bulldozer blade control device having the second feature, when the transmission is detected to be in the reverse running state and the operation mode setting means sets the operation mode to the automatic operation mode, When the blade is at a position higher than the reverse running position, the blade is lowered, and when the blade is at a position lower than the reverse running position, the blade is raised, so that the lower end of the blade is located a predetermined distance above the ground. The blade is controlled to be in the reverse traveling position.

[0013] With this configuration, the operator can smoothly move the blade to the predetermined reference position during the reverse running without causing much fatigue, and the dozing operation can be performed efficiently. It is possible to prevent the occurrence of a fall accident or the like caused by running the vehicle while being raised above a predetermined height.

In the present invention, it is preferable to provide a blade elevating / lowering means having a pair of hydraulic cylinders disposed between the left and right ends of the blade and the vehicle body, for example. Further, it is preferable that a blade position detecting means for detecting a vertical movement position of the blade is provided. Here, as the blade position detecting means, it is preferable to detect the vertical movement position of the blade by detecting the stroke amount of a pair of hydraulic cylinders in the blade vertical movement means.

Further, in the present invention, there is provided an operation mode switching means for switching the operation mode from the automatic operation mode to the manual operation mode after the blade control means raises or lowers the blade to the reverse travel position. Preferably, it is provided.

The automatic operation mode may include at least an automatic excavation operation mode relating to excavation in a dozing operation and an automatic soil operation mode relating to soil transportation in a dozing operation.

Further, the operation mode setting means may be constituted by a push operation changeover button, a grip operation changeover switch, a twist operation changeover switch or a rotary changeover switch.

[0018] Other objects of the present invention will become apparent from the following detailed description. However, while the detailed description and specific examples describe the most preferred embodiments, various modifications and variations within the spirit and scope of the present invention will be apparent to those skilled in the art from the detailed description, and thus the specific examples It is described only as

[0019]

Next, a specific embodiment of a bulldozer blade control device according to the present invention will be described with reference to the drawings.

In a bulldozer 1 whose appearance is shown in FIG. 1, a hood 3 containing an engine (not shown) and an operator seat 4 for an operator who operates the bulldozer 1 are provided on a body 2 of the bulldozer 1. It is arranged. Further, on both sides of the vehicle body 2, in other words, on each of the left and right sides in the forward direction of the vehicle body 2, a crawler belt 5 for moving the vehicle body 2 forward, backward and turning (crawler belts on the right side are not shown) is provided. ing. These crawler tracks 5
Is independently driven for each crawler belt 5 by the corresponding sprocket 6 by the driving force transmitted from the engine.

On the left and right sides of the vehicle body 2, the base ends of the left and right straight frames 8, 9 for supporting the blades 7 at the distal ends are trunnions 10 (the right trunnions are not shown). ) Pivots the blade 7 so that it can be raised and lowered. Further, the blade 7 has a pair of left and right blade lift cylinders 11 for raising and lowering the blade 7 between the vehicle body 2 and a brace 12 and a blade tilt cylinder 13 for tilting the blade 7 right and left. Between the left straight frame 8 and the blade tilt cylinder 1
3 is provided between the right straight frame 9.

A steering lever 15, a shift lever 16 and a fuel control lever 17 are provided on the operator seat 4 on the left side of the vehicle body 2 in the forward direction, and the blade 7 is raised, lowered, tilted to the left and right on the right side. Blade control lever 1 for tilting right
8. First and second dial switches 19A and 19B for setting a load applied to the blade 7 and for correcting increase / decrease of the set load, a lock-up switch 2 for switching lock-on / off of a torque converter.
0 and a display device 21 are provided. At the top of the blade control lever 18, there is provided an operation mode switching button 22 for sequentially switching to a manual operation mode, an automatic excavation operation mode, and an automatic soil operation mode of the dozing operation in accordance with the number of pressing operations. Also,
Although not shown, a brake pedal and a dexel pedal are provided in front of the operator seat 4.

Next, in FIG. 2 showing the power transmission system, the rotational driving force from the engine 30 is applied to the damper 3.
The power is transmitted to a lock-up torque converter 33 having a lock-up mechanism 33a and a pump 33b via a PTO 32 that drives various hydraulic pumps including the hydraulic pump 1 and the work machine hydraulic pump. Next, from the output shaft of the torque converter with lock-up 33, the rotational driving force is transmitted to a transmission 34 that is, for example, a planetary gear wet multi-plate clutch transmission in which the input shaft is connected to the output shaft. The transmission 34 includes forward and reverse clutches 34a and 34b and first to third speed clutches 34c to 34c.
34e, the output shaft of the transmission 34 is rotated at three speeds in the forward and backward directions. Subsequently, the rotational driving force from the output shaft of the transmission 34 is applied to a steering mechanism 35 having a pinion 35a and a bevel gear 35b, and a horizontal shaft 35e on which a pair of left and right steering clutches 35c and a steering brake 35d are disposed. Each sprocket 6 that is transmitted to the pair of left and right final reduction mechanisms 36 via the crawler belt 5 and travels the crawler belt 5 is driven. Reference numeral 37 denotes an engine rotation sensor that detects the rotation speed of the engine 30, and reference numeral 38 denotes a torque converter output shaft rotation sensor that detects the rotation speed of the output shaft of the torque converter 33 with lockup.

On the other hand, FIG. 3 schematically shows the entire bulldozer blade control device according to the present invention.
The set load applied to the blade 7 from the first and second dial switches 19A and 19B, each dial value data for increase / decrease correction to the set load, the manual operation mode of the dosing operation by the operation mode switching button 22, the automatic operation mode The state of button pressing operation when switching to the excavation operation mode or the automatic soil operation mode, the rotation speed data of the engine 30 from the engine rotation sensor 37, and the rotation of the output shaft of the torque converter 33 from the torque converter output shaft rotation sensor 38. The numerical data is supplied to the microcomputer 40 via the bus 39. The microcomputer 40 further includes a blade lift cylinder stroke sensor 41 for detecting the left and right stroke amounts of the pair of left and right blade lift cylinders 11 for raising and lowering the blade 7.
Data of each stroke position, tilt angle data from a tilt angle sensor 42 for detecting the instantaneous tilt angle of the vehicle body 2 in the front-rear direction, speed gear switching state of the transmission 34 based on the speed gear switching by operating the shift lever 16 Transmission speed changeover sensor 43 for detecting
Speed change status from blade, blade control lever 1
8, a manual operation status from a blade operation sensor 44 for detecting whether or not the blade 7 is in a manual operation operation, and a torque converter based on lock-up on / off switching by switching operation of the lock-up switch 20. A torque converter L / U that detects the lockup (L / U) / torque converter (T / C) switching status of the 33
The L / U / T / C switching status from the T / C switching sensor 45 is supplied via the bus 39.

The microcomputer 40 includes a central processing unit (CPU) 40A for executing a predetermined program, a read-only memory (ROM) 40B for storing the program and various maps such as an engine characteristic curve map, a torque converter characteristic curve map, and the like. It is composed of a writable memory (RAM) 40C as a working memory required to execute this program and various registers, and a timer 40D for measuring time during the program. The set load applied to the blade 7 and the dial value data for increasing / decreasing the set load, the pressing state of the operation mode switching button 22, the rotation speed data of the engine 30, and the torque converter 33 Rotational speed data of the output shaft, left and right stroke position data of the blade lift cylinder 11, data on the inclination angle of the vehicle body 2 in the front-rear direction, speed stage switching state of the transmission 34, manual operation operation state of the blade 7, L of the torque converter 33 The lift operation amount for raising or lowering the blade 7 by executing the above-mentioned program is supplied to the blade lift cylinder controller 46 based on the / UTT / C switching status, and is supplied to the blade lift cylinder controller 46 via the lift valve actuator 47 and the lift cylinder operation valve 48. A pair of left and right blade lift Sunda 11 is raised or lowered the blade 7 by being driven and controlled based on the lift operation amount. Further, by executing the program of the microcomputer 40, a tilt operation amount for tilting the blade 7 to the left and right is supplied to the blade tilt cylinder controller 49, and the blade tilt cylinder 13 is driven and controlled via the tilt valve actuator 50 and the tilt cylinder operation valve 51. This causes the blade 7 to tilt. Note that the display device 21 displays whether the bulldozer 1 is currently in a manual operation mode, an automatic excavation operation mode, an automatic soil operation mode, or the like for dozing work.

As shown in FIG. 4, the blade lift cylinder stroke sensor 41 detects the stroke amount of the blade lift cylinder 11 based on the tilt amount of the blade lift cylinder 11 (FIG. The left side of the bulldozer 1 is shown enlarged.) That is, the left and right blade lift cylinders 1
1 is supported by a disk-shaped cylinder support 53 that is rotatably supported in a vertical plane with respect to a mounting bracket 52 fixed to the body of the bulldozer 1;
A potentiometer 54 forming a part of the blade lift cylinder stroke sensor 41 is attached to the body of the vehicle body 2 adjacent to the cylinder support 53. And
The tip of an arm 56 attached to a rotating shaft 55 of the potentiometer 54 and the rotating part of the cylinder support 53 are connected by a rod 57, and the blade lift cylinder 11
Is rotated from the one-dot chain line position to the two-dot chain line position in FIG. 4, the arm 56 is pushed by the rod 57 and the arm 56 is turned in the direction of arrow A. The turning angle is detected by the potentiometer 54. It has become. Also,
Since one blade lift cylinder stroke sensor 41 is provided for each of the left and right blade lift cylinders 11, the difference between the stroke amounts of the blade lift cylinders 11 detected by the left and right blade lift cylinder stroke sensors 41. By calculating
The tilt amount of the blade 7 is also detected by the operation of the blade tilt cylinder 13.

Next, the operation of the bulldozer blade control device configured as described above will be described in detail with reference to the flow charts of FIGS.

S1 to S3: Execution of a predetermined program is started by turning on the power and the RAM 40 in the microcomputer 40
Initialization such as clearing the contents of various registers set in C is performed. Next, in this embodiment after initialization, the inclination angle data is sequentially read from the inclination angle sensor 42 as an initial value for 5 seconds. The reason why the tilt angle data is sequentially read as an initial value is to obtain the tilt angle of the vehicle body 2 by frequency separation based on a moving average of the tilt angle data.

S4 to S6: First, the set load applied to the blade 7 from the first and second dial switches 19A and 19B and each dial value data for increasing / decreasing the set load, and the operation mode switching button 22 Button pressing operation status, engine speed sensor 37 to engine 30 speed data, torque converter output shaft speed sensor 38 to torque converter 33 output shaft speed data, blade lift cylinder stroke sensor 41
Data of each stroke position of the blade lift cylinder 11, tilt angle data of the vehicle body 2 in the front-rear direction from the tilt angle sensor 42, the transmission speed stage switching sensor 43 to the speed stage switching state of the transmission 34, the blade operation sensor 44 to the blade 7 The manual driving operation status and the L / U / T / C switching status of the torque converter 33 are read from the torque converter L / UT / C switching sensor 45.
Next, when the power supply voltage is equal to or higher than the predetermined voltage and the electronic circuit or the like is in a normal driving state, the following data processing is performed. 1. A low frequency component is extracted from the sequentially read inclination angle data by frequency separation by the moving average method to obtain an inclination angle of the vehicle body 2. 2. Next, an acceleration component is extracted by frequency separation of subtracting the low frequency component from the above-described sequentially read inclination angle data to obtain the acceleration of the vehicle body 2.

S7 to S12: When the speed stage of the transmission 34 is the first forward speed (F1) or the second forward speed (F2), the torque converter 33 locks up (L
/ U) or the torque converter (T / C), the actual tractive force F _R is calculated as follows. 1. At the time of lock-up, an engine torque Te is obtained from an engine characteristic curve map as shown in FIG. Next, the transmission 34, the steering mechanism 35 and the final reduction mechanism 36 are applied to the engine torque Te.
In other words, the traction force Fe (= Te · k _se · r) is obtained by multiplying the reduction ratio k _se from the output shaft of the torque converter 33 to the sprocket 6 by the diameter r of the sprocket 6.
Further, the traction force correction corresponding to the pump consumption of the working machine hydraulic pump or the like for the blade lift cylinder 11 in the PTO 32 obtained from the pump correction characteristic map as shown in FIG. The actual traction force F _R (=
Fe-Fc). 2. A speed ratio e (= Nt / N), which is a ratio of the rotation speed Ne of the engine 30 to the rotation speed Nt of the output shaft of the torque converter 33 at the time of the torque converter
torque coefficient from the torque converter characteristic curve map as shown in FIG. 9 by e) t _p and obtains the torque ratio t torque converter output torque Tc [= t _p · (Ne
/ 100) ² · t]. Next, the actual traction force F is obtained by multiplying the torque converter output torque Tc by the reduction ratio k _Se from the output shaft of the torque converter 33 to the sprocket 6 and the diameter r of the sprocket 6 in the same manner as in the previous section.
_R (= Tc · k _Se · r) is obtained.

Next, the actual traction force F obtained in this manner is obtained.
_{From R} , the load correction amount corresponding to the inclination angle of the vehicle body 2 obtained from the inclination angle-load correction amount characteristic map as shown in FIG. 10 is subtracted to obtain the corrected actual traction force F.

Next, the lift tilt relative angle of the blade 7 is calculated from the rotation angles of the left and right blade lift cylinders 11 measured by the potentiometer 54 of the blade lift cylinder stroke sensor 41.

S13-S14: Operation mode switching button 2
When the operation mode at the time of dosing work is in the automatic operation mode by the number of pressing operations of 2, when the number of pressing operations is in the automatic excavation operation mode of one time or when the number of pressing operations is in the automatic soil operation mode of two times The target traction force is set as follows according to. If the number of pressing operations is zero or three, the operation mode is set to the manual operation mode.

1. In the automatic digging operation mode, the actual traction force F ′ after the initial correction at the time of switching to the automatic digging operation mode is compared with the dial value of the load applied to the blade 7 set by the first dial switch 19A, and further with the lower limit value. And the target tractive force F corresponding to the dial value
Cumulative value X of unit traction force component ΔW added and accumulated each time the program is repeated so that actual traction force gradually approaches ₀
The provisional target tractive force F ₀ is calculated based on the following formula.
Are sequentially obtained. The repetition time of the program is 20 ms in this embodiment. i) When the actual traction force F 'after the initial correction exceeds the dial value: The provisional target traction force F ₀ ← the actual traction force F' after the initial correction-cumulative value X ii) The actual traction force F 'after the initial correction is the difference between the dial value and the lower limit value In the case between: provisional target traction force F ₀ ← actual traction force after initial correction F ' ₀ +
Cumulative value X iii) When actual traction force F ′ after initial correction is less than lower limit value Temporary target traction force F ₀ ← lower limit value + cumulative value X

In this manner, the process is repeated until the provisional target traction force F ₀ reaches the traction force corresponding to the dial value of the load applied to the blade 7 to be set, and when the traction force corresponding to the dial value is reached, the traction force corresponds to the dial value. to set the traction force as a target tractive force F _0. It is to be noted that the lower limit value is determined if the actual traction force is small and fluctuates when it is not clear whether the blade edge of the blade 7 hits or floats on the excavation surface, and the blade 7 stably moves up or down. Cannot be controlled.

2. In automatic soil operation mode Blade 7 set by first dial switch 19A
A predetermined value α, in this embodiment, 0.1 to 0.2 W (W: the total weight of the bulldozer 1) is subtracted from the dial value of the load applied to, and the target traction force F ₀ is set.

S15 to S16: The difference between the target tractive force and the corrected actual tractive force ΔF is obtained, and the display device 21 indicates that the dosing operation is in the manual operation mode, the automatic excavation operation mode, or the automatic soil operation mode. .

S17 to S21: Whether or not the current control area of the bulldozer is within the normal blade position control area in the automatic operation mode is detected by a sensor (not shown) or the like, and the current control area of the bulldozer is set in the automatic operation mode. When the transmission is not in the normal blade position control area, in other words, when the load applied to the blade 7 is not in the constant load control area, the transmission is in the forward traveling position and the blade is in the forward traveling position. 7 is not at the excavation start position, so that the lower end of the blade 7 is on the ground (Gr.
The following processing is performed depending on whether the position reaches the sound line and whether the lower end of the blade 7 is horizontal with respect to the vehicle body.

1. When the lower end of the blade 7 in the blade lift cylinder stroke sensor 41 detects the position of the blade 7 does not reach the ground, with the lift operation amount Q _D lowering the lower end of the blade 7 to the ground, the blade A lowering command is issued to the lift cylinder 11. 2. Left and right blade lift cylinder stroke sensors 4
When one of the lower end of the blade 7 by detecting the difference between the detected value is not in the horizontal relative to the vehicle body, with the tilt operation amount Q _T to level the bottom of the blade 7 relative to the vehicle body, A tilt command is issued to the blade tilt cylinder 13.

Thus, after the blade 7 is lowered toward the ground, the blade 7 is tilted so that the lower end of the blade 7 is horizontal to the vehicle body, and one end of the blade 7 has already reached the ground. Sometimes, only the other end is tilted, whereby the blade 7 is lowered to the ground with the lower end in a horizontal state and reaches a predetermined reference position at the start of excavation.

S22 to S24: If the current control area of the bulldozer is in the area of normal blade position control (constant load control) in the automatic operation mode, the following processing is performed.
First, based on the moving average acceleration obtained by the moving average of the acceleration of the vehicle body 2 obtained from the acceleration component extracted from the inclination angle data in the frequency separation, and further based on the corrected actual traction force F, shoe slip, in other words, Hull 2
Is detected as running slip. 1. Conditions for running slip (1 ° ≒ 0.0174G) Moving average acceleration γ <-4 ° or moving average acceleration γ <-2 ° and corrected actual tractive force F>
0.6W 2. Conditions under which running slip is eliminated after running slip Average acceleration γ> 0.1 ° or corrected actual traction force F> corrected actual traction force F-0.1 W at the start of running slip

Next, the following processing is performed when a running slip is detected based on the above-described conditions and when no running slip is detected instead of the running slip. 1. If running slip is detected, the blade 7
In order to reduce the amount of load applied to
The blade 7 is determined by a slip control characteristic map (not shown).
Obtaining a lift operation amount Q _S for increasing the. 2. If it is determined that there is no detection instead of running slip, the traction force difference ΔF between the target traction force F ₀ and the corrected traction force F is used as shown in FIG.
The corrected tractive force F from the load control characteristic map shown in 1 to obtain a lift operation amount Q _L to raise or lower the blade 7 so as to match the target pulling force F _0.

S25 to S28: When the transmission is switched to the reverse traveling position (R), the blade position at the time of this switching is not at a predetermined height position (minimum ground height) which is the position during reverse traveling. And blade 7
To give a lift operation amount Q _H to raise or lowered to a predetermined height position, issue a rise or descent command to the blade lift cylinders 11. Then, when the blade 7 is raised or lowered by such processing and reaches the reverse traveling position, the operation mode is switched from the automatic operation mode to the manual operation mode.

If the power supply voltage is not normal below the predetermined voltage and the electronic circuit or the like is not in a normal driving state, the speed stage of the transmission 34 is other than the first forward speed (F1) or the second forward speed (F2). If manually in some cases the operating mode to obtain the lift operation amount Q _N to raise or lower the blade 7 in step S29 by the manual control characteristic map (not shown) according to the operation amount of the blade control lever 18.

Each of the lift operation amounts Q described above_D, Q_S, Q_L,
Q_H, Q_NIs the blade lift cylinder controller 4
6 and each lift operation amount Q_D, Q_S, Q_L,
Q_H, Q _NLift valve actuator 47 and
Blade lift system through the lift cylinder operating valve 48
Drive the lid 11 and raise or lower the blade 7
The desired control for lowering is performed, and the tilt operation amount Q
_TSupplied to the blade tilt cylinder controller 49
And the tilt valve actuator 50 and the tilt syringe
The blade tilt cylinder 13 is driven through the
And the desired control for tilting the blade 7 is performed.
You.

In this embodiment, in steps S18 to S21 in the above-described flowchart, after the blade 7 is lowered toward the ground, the lower end of the blade 7 is tilted so as to be horizontal to the vehicle body (tilt). Although the blade 7 is tilted so that the lower end of the blade 7 is horizontal to the vehicle body, the blade 7 may be lowered toward the ground. in this case,
Steps S18 to S21 are replaced with steps S18 'to S21' as shown in FIG. Also,
An embodiment in which the tilt operation is performed while performing the lowering operation of the blade 7 is also possible.

In this embodiment, when the transmission is switched to the reverse position, the blade 7 is raised or lowered so as to approach the predetermined height position. In this manner, the transmission is switched to the reverse position. At this time, the blade 7 may be once raised to the position of the bonnet 3 and then lowered to the reverse traveling position.

In the present embodiment, whether the transmission 34 is in the forward running state or the reverse running state is determined based on the signal from the transmission speed changeover sensor 43, but the operating position of the shift lever 16 is determined. A switch can be provided to make the determination.

In the present embodiment, the actual tractive force is obtained by calculation when detecting the actual tractive force. However, a driving torque sensor for detecting the driving torque of the sprocket 6 is provided.
The actual traction force may be obtained and detected based on the driving torque amount detected by the driving torque sensor. Further, a bending stress sensor for detecting a bending stress amount by the straight frame 8 supporting the blade 7 in the trunnion 10 is provided, and an actual traction force is obtained and detected based on the bending stress amount detected by the bending stress sensor. Is also good.

In this embodiment, the case where the torque converter with lockup 33 is provided in the power transmission system has been described. However, even in the case of a torque converter having no lockup mechanism, no torque converter is provided. It goes without saying that the present invention can be applied to a direct mission. The calculation of the actual tractive force in the case of this direct mission is the same as in the case of the lock-up described above.

In the present embodiment, the running slip of the vehicle body 2 is detected by extracting the acceleration component by frequency separation from the tilt angle data output from the tilt angle sensor 42, but a separate acceleration sensor is provided. The detection may be performed from an output from the acceleration sensor indicating the acceleration state of the vehicle body 2. Further, a Doppler vehicle speedometer may be provided, and the detection may be performed by comparing the actual vehicle speed of the vehicle body 2 obtained by the Doppler vehicle speedometer with the traveling speed of the crawler belt 5 on which the vehicle body 2 travels.

In the present embodiment, the operation mode is switched by the operation mode switch button 22 of the push operation type. However, a grip operation switch, a twist operation switch, or a rotary switch may be used.

As described above, it is apparent that the present invention can be variously modified. Such modifications do not depart from the spirit and scope of the invention, and all such changes and modifications which are obvious to a person skilled in the art are intended to be covered by the appended claims.

[0054]

As described above, according to the present invention, the operation that is repeatedly performed by the operator at the start of excavation or at the time of reverse traveling can be omitted, thereby reducing the fatigue of the operator. It is possible to improve safety at the time of work.

[Brief description of the drawings]

FIG. 1 is an external view of a bulldozer according to one embodiment of the present invention.

FIG. 2 is a skeleton diagram of a power transmission system.

FIG. 3 is an overall schematic block diagram.

FIG. 4 is a detailed view of a blade lift cylinder stroke sensor.

FIG. 5 is a flowchart (the former stage) of a dosing program.

FIG. 6 is a flowchart (later stage) of a dosing program.

FIG. 7 is a graph of an engine characteristic curve map.

FIG. 8 is a graph of a pump correction characteristic map.

FIG. 9 is a graph of a torque converter characteristic curve map.

FIG. 10 is a graph of an inclination angle-load correction characteristic map;

FIG. 11 is a graph of a load control characteristic map.

FIG. 12 is a partial flowchart of a modified example of the dosing program.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 bulldozer 2 body 7 blade 11 blade lift cylinder 12 brace 13 blade tilt cylinder 16 shift lever 18 blade control lever 22 operation mode switching button 34 transmission 40 microcomputer 41 blade lift cylinder stroke sensor 42 inclination angle sensor 43 transmission speed step switching sensor 46 blade Lift cylinder controller 49 Blade tilt cylinder controller 54 Potentiometer

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Satoru Nishida 3-1-1 Ueno, Hirakata-shi, Osaka Prefecture Inside the Komatsu Manufacturing Osaka Plant (72) Inventor Kazushi Nakata 3-1-1 Ueno, Hirakata-shi, Osaka Prefecture Co., Ltd. (56) References JP-A-4-5712 (JP, A) JP-A-54-112503 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) E02F 3 / 84-3/85 E02F 3/43

Claims (17)

(57) [Claims] (A) an operation mode setting means for setting an operation mode during a dozing operation to an automatic operation mode; and (b) a traveling state detection for detecting whether the transmission is in a forward traveling state or a reverse traveling state. Means and (c) the driving state detecting means detects that the transmission is in the forward running state, and at the start of excavation when the operation mode is set to the automatic operation mode by the operation mode setting means, the lower end of the blade is moved to the vehicle body. A blade control device for a bulldozer, comprising: blade control means for controlling a tilting movement and a downward movement of the blade so as to be horizontal with respect to the blade and to make the lower end of the blade contact the ground. 2. The bulldozer blade control device according to claim 1, further comprising blade raising / lowering means for raising or lowering the blade. 3. The bulldozer blade control device according to claim 2, wherein said blade lifting / lowering means has a pair of hydraulic cylinders respectively arranged between left and right ends of said blade and a vehicle body. apparatus. 4. The bulldozer blade control device according to claim 3, further comprising a blade position detecting means for detecting a vertical movement position and a tilt movement position of the blade. 5. The blade position detecting means detects a vertical movement position and a tilt movement position of the blade by detecting a stroke amount of a pair of hydraulic cylinders in the blade vertical movement means. Item 5. A bulldozer blade control device according to item 4. 6. The bulldozer blade control device according to claim 1, further comprising blade tilting means for tilting the blade with respect to the vehicle body by raising or lowering the left and right ends of the blade. . 7. The blade tilting means includes one hydraulic cylinder disposed between one end of the blade and the vehicle body, and one hydraulic cylinder disposed between the other end of the blade and the vehicle body. The bulldozer blade control device according to claim 6, wherein the bulldozer has two braces. 8. The bulldozer blade control device according to claim 1, wherein the blade control means controls the blade so that the blade moves downward after tilting the blade. 9. The bulldozer blade control device according to claim 1, wherein the blade control means controls the blade so that the blade is tilted after the blade is moved downward. 10. An operation mode setting means for setting an operation mode during a dosing operation to an automatic operation mode, and (b) a traveling state detection for detecting whether the transmission is in a forward traveling state or a reverse traveling state. Means and (c) when the traveling state detecting means detects that the transmission is in the reverse traveling state, and when the operation mode is set to the automatic operation mode by the operation mode setting means, the lower end of the blade moves relative to the ground. A bulldozer blade control device, comprising: blade control means for controlling the raising or lowering of the blade so as to be a reverse traveling position located a predetermined distance above. 11. The bulldozer blade control device according to claim 10, further comprising blade raising / lowering means for raising or lowering the blade. 12. The blade raising / lowering means includes a pair of hydraulic cylinders disposed between left and right ends of the blade and a vehicle body, respectively.
A bulldozer blade control device according to claim 1. 13. The bulldozer blade control device according to claim 12, further comprising blade position detecting means for detecting a vertical movement position of the blade. 14. The blade position detecting means according to claim 13, wherein said blade position detecting means detects a moving position of said blade by detecting a stroke amount of a pair of hydraulic cylinders in said blade moving means. Bulldozer blade controller. 15. An operation mode switching means for switching the operation mode from the automatic operation mode to the manual operation mode after the blade control means raises or lowers the blade until the blade moves to the reverse traveling position. The blade control device for a bulldozer according to claim 10, wherein 16. The automatic operation mode according to claim 1, wherein the automatic operation mode includes at least an automatic excavation operation mode relating to excavation in the dozing operation and an automatic soil operation mode relating to soil transportation in the dozing operation. A bulldozer blade controller as described. 17. The bulldozer blade according to claim 1, wherein said operation mode setting means comprises a push operation changeover button, a grip operation changeover switch, a twist operation changeover switch or a rotary changeover switch. Control device.