JP2897069B2 - Travel control device for construction machinery - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a travel control device for construction machines such as a hydraulic shovel.

2. Description of the Related Art FIG. 5 is a perspective view showing the vicinity of a driver's seat 1 of a hydraulic shovel provided with a traveling control device of a conventional technology. In the figure, 2 is a floor plate, 3L and 3R are left and right tread members, 4L and 4R are running levers fixed to the left and right tread members 3L and 3R, respectively.
L and 5R are operation levers for work, respectively. FIG. 6 is a main part circuit diagram of a hydraulic excavator provided with a traveling control device of the prior art. In the figure, 7L and 7R denote a pair of left and right pedal devices, 8 and 9 denote pilot pressure deriving means of the pedal device 7L, respectively, forward and reverse pilot valves, and 10 and 11 denote pilot pressure deriving means of the pedal device 7R. For each forward,
Reverse pilot valve, 12L and 12R are left and right traveling motors, 13
L and 13R are cylinders for adjusting the tilt angle of the traveling motors 12L and 12R.
L and 14R are speed switching valves respectively, 15 is a 1-speed / 2-speed switching solenoid valve, 16L and 16R are pilot switching valves for controlling the traveling motors 12L and 12R, 17, 18 are main pumps, 19 is a pilot pump, 20 is an oil tank, 21 is an engine, 22 is an engine
Reference numeral 21 denotes a governor, 23 denotes a stepping motor as an actuator for the governor 22, 24 denotes an engine rotation sensor, 25 denotes a controller, and 26 denotes an engine rotation mode changeover switch. When switching the engine rotation mode, the mode changeover switch 26 is set to the H position (high-speed rotation position), the S position (medium-speed rotation position), and the FC position (low-speed rotation position) as required.
Is switched to one of. Also, the signs ii, roro,
Ha-ha and ni-ni indicate the connection of the pilot pipeline.

Next, FIGS. 5 and 6 of a conventional traveling control device will be described. By operating the pair of pedal devices 7L and 7R, the pilot pressure is derived from the respective pilot valves (any one of the pilot valves 8 to 11), and the pilot pressure is applied to the pair of pilot switching valves 16L and 16R, respectively. Acts on the pilot pressure receiving portion (any one of 27, 30, and 30) to operate pilot switching valves 16L, 16L.
R is switched and the left and right traveling motors 12L and 12R are operated. The rotation speeds of the traveling motors 12L and 12R can be set to a required traveling speed by operating the switch 31 communicating with the first-speed / second-speed switching electromagnetic valve 15 and the mode switching switch 26.

Problems to be Solved by the Invention In the tracked vehicle of the prior art, when performing straight running, the driver performs left and right operations with left and right feet, respectively. In such a case, the timings of performing the left and right operations simultaneously with both feet do not completely match, or the two feet do not perform the same movement at the same time. In particular, when the driver manually operates the work operation lever during straight running, the driver's attention to both feet is neglected, and the crawler vehicle meanders, which is extremely dangerous.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the problems described above and to provide a travel control device for a construction machine that can be operated by a driver with one foot when a crawler vehicle travels straight.

Means for Solving the Problems A pair of pedal devices, a pair of pilot pressure deriving devices for deriving a pilot pressure corresponding to a forward or backward operation of the pair of pedal devices, and a pilot pressure from the pair of pilot pressure deriving devices A traveling control device for a construction machine having a pair of pilot switching valves that are controlled to be switched by the control unit and left and right traveling motors that are operated and controlled by the switching control of the pair of pilot switching valves. A dedicated pilot pressure deriving means for deriving a pilot pressure by operating the device; and one of the pilot pressure from the pair of pilot pressure deriving means and the pilot pressure from the straight driving dedicated pilot pressure deriving means. Selectively act on the pilot pressure receiving portion of the pair of pilot switching valves. I did it.

Furthermore, detecting means for detecting the operation state of the pedal device dedicated to straight ahead, a controller to which a detection signal from the detecting means is input, and an engine rotation command signal output from the controller based on the detection signal are provided. The governor of the engine to be input is provided.

Further, detecting means for detecting an operation state of the pedal device for straight ahead, a controller to which a detection signal from the detecting means is inputted, and a traveling speed switching operation command signal outputted from the controller based on the detection signal. And a traveling speed switching means for adjusting the rotation speed of the traveling motor.

Still further, the vehicle includes a forward / reverse selection valve provided in a line communicating the straight-travel-only pilot pressure deriving means and the pilot switching valve, and a switching means for controlling the forward-reverse selection valve. A one-way operation pedal operable only in one direction, wherein the straight-movement-only pilot pressure deriving means derives pilot pressure only in a single direction by operating the one-way operation pedal; and The direction of the pilot pressure can be switched.

Effect In the travel control device for a construction machine of the present invention, the dedicated pedal device for straight traveling is provided, so that the construction machine can travel straight forward accurately by depressing the pedal device for straight travel with one foot.

Further, detecting means for detecting the operation state of the straight-ahead pedal device, a controller to which a detection signal from the detecting means is input, and an engine rotation command signal output from the controller based on the detection signal are input. If the governor of the engine is provided, it is possible to automatically obtain an engine speed suitable for the straight traveling during the operation of the construction machine in conjunction with the depression operation of the pedal device for straight traveling.

Further, a detecting means for detecting an operation state of the pedal device for straight ahead, a controller to which a detection signal from the detecting means is input, and a traveling speed switching operation command signal output from the controller based on the detection signal. If the traveling speed switching means for adjusting the rotation speed of the traveling motor is provided, the traveling speed suitable for the straight traveling at the time of the operation of the construction machine is automatically adjusted in conjunction with the depression operation of the straight traveling dedicated pedal device as described above. Can be obtained.

Furthermore, if the pedal device for straight traveling can be operated only in one direction and the switching means for switching between forward and backward is provided,
Depressing operation of the pedal device for straight ahead becomes easy.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(1) FIG. 1 is a main part circuit diagram showing a travel control device 32 of a first embodiment according to the present invention. In the figure, the same reference numerals are given to components using the same components as the conventional technology. 33 is a pedal device for straight ahead, 34 is a pedal device for straight ahead
Reference numeral 33 denotes a tread member, and reference numerals 35 and 36 denote a forward pilot valve, a reverse pilot valve,
Is a pilot pressure hydraulic pressure source, and 38, 39, 40, and 41 are pilot pressure selection shuttle valves, respectively.

Next, the configuration of the travel control device 32 of the first embodiment will be described with reference to FIG. A single straight-moving pedal device 33 is provided near the pair of pedal devices 7L and 7R.
The pilot pressures derived from the forward pilot valves 8 and 10 of the L and 7R, respectively, and the pilot pressure derived from the forward pilot valve 35 of the straight-only pedal device 33 are selectively used as the pilot pressure. The pilot pressure receiving portions 27 and 29 for forward movement of the pair of pilot switching valves 16L and 16R are acted on, and the pilot pressures derived from the backward movement pilot valves 9 and 11 of the pair of pedal devices 7L and 7R, respectively, Pilot valve for reverse travel of pedal device 33 for straight travel only
One of the pilot pressures derived from 36 is selectively used as the pair of pilot switching valves 16L, 16R.
To act on the pilot pressure receiving portions 28 and 30 for reverse. At the time of the forward operation of the straight-moving pedal device 33, the pair of pilot switching valves 16L and 16R are simultaneously set to the E position and the G position, respectively. It is configured to switch to the F position and H position, respectively.

Next, the function of the travel control device 32 will be described. First, when operating the pair of left and right pedal devices 7L and 7R, the pair of pilot switching valves 16L and 16R perform the same switching operation as in the related art. However, when trying to advance a hydraulic excavator (a crawler vehicle equipped with the travel control device 32, not shown), the tread surface member 34 of the pedal device 33 for straight ahead is stepped forward. Since the forward pilot valve 35 is switched,
The pilot pressure from the pilot pressure hydraulic pressure source 37 passes through a pilot valve 35 and a pipe 42, while one is a pipe 43, a shuttle valve 38,
Via the pipe line 44, it acts on the pilot pressure receiving portion 27 of the pilot switching valve 16L. At the same time, the pilot pressure branches in the pipe 42, and acts on the pilot pressure receiving portion 29 of the pilot switching valve 16R through the pipe 45, the shuttle valve 40, and the pipe 46. The pilot switching valves 16L and 16R are simultaneously switched to the forward e position and the forward position, respectively. When the vehicle is to be moved backward, the treading member 34 of the pedal device 33 for straight traveling is depressed rearward. Since the reverse pilot valve 36 is switched, the pilot switching valves 16L and 16R are simultaneously switched to the reverse position and the H position, respectively.

Therefore, by performing the stepping operation of one pedal device 33 dedicated to straight traveling, the hydraulic shovel can be caused to travel straight ahead or in the direction.

(2) FIG. 2 is a main part circuit diagram showing a travel control device 47 according to a second embodiment of the present invention. In the figure, the same reference numerals are given to components using the same components as the conventional technology. 33 is a pedal device for continuous running, 34 is a pedal device for straight running
33 tread members, 35 and 36 are forward pilot valves, reverse pilot valves,
38,3940,41 are shuttle valves for pilot pressure selection,
48 is a potentiometer provided on the pedal device 33, 25 'is a controller, 49 is a traveling speed selection switch, 50 is 1st speed / 2
The speed changeover switch codes "Relie", "Null", "Rul", and "Oh" indicate the connections of the pipelines.

Next, the configuration of the travel control device 47 of the second embodiment will be described with reference to FIG. For a single linear pedal device 33 provided near a pair of pedal devices 7L and 7R, a potentiometer 48 for detecting that the linear pedal device 33 is in an operating state is provided, and a detection signal from the potentiometer 48 is provided. Is input to the controller 25 ', and the controller 25' outputs an engine speed command signal to the governor 22 of the engine 21 based on the detection signal. The rotation speed of the motors 12L and 12R is set in advance by the traveling speed selection switch 49.
The speed is adjusted to the set speed.

Next, the function of the travel control device 47 will be described. When the straight pedal device 33 is operated, a detection signal from the potentiometer 48 is input to the controller 25 '. The controller 25 'outputs an engine speed command signal to the governor 22 of the engine 21 via the stepping motor 33 based on the detection signal. At the same time, an on / off switching operation command signal is output to the first speed / second speed switching switch 50. Thereby, the traveling motor 12L,
The rotation speed of the 12R can be automatically adjusted to the traveling speed (any one of a, to f) set in advance in the traveling speed selection switch 49.

(3) FIG. 3 is a main part circuit diagram showing a travel control device 51 of a third embodiment according to the present invention. In the figure, the same reference numerals are given to components using the same components as the conventional technology. 38, 39, 40, 41 are pilot pressure selection shuttle valves, 37 is a pilot pressure hydraulic pressure source, 52 is a one-way operation pedal device, 53 is a tread member of the one-way operation pedal device 52, 54
Is a pilot valve as pilot pressure deriving means, 55 is a forward / reverse selection valve, 56 and 57 are left and right solenoids of the forward / reverse selection valve 55, 58 is a changeover switch, 59 is a power supply, and F and R are each a changeover switch 58. This is the forward / reverse switching operation position.

Next, the configuration of the travel control device 51 of the third embodiment will be described with reference to FIG. A single one-way operation pedal device 52 is provided near the pair of pedal devices 7L, 7R, and the pilot switching valve 16L,
A forward / reverse selection valve 55 is provided in a pipe line communicating with each of the pilot pressure receiving sections 27, ..., 30 of the 16R, and a changeover switch 58 for controlling the front / rear selection valve 55 is provided, and the pair of pedal devices 7L, 7R each pilot valve and pilot pressure derived from 27, ..., 30 and the one-way operation pedal device 52
One of the pilot pressures derived from the pilot valve 54 is selectively applied to the pilot pressure receiving portions 27, 30 of the pair of pilot switching valves 16L, 16R. When the one-way operation pedal device 52 is operated by operating the changeover switch 58, the pair of pilot changeover valves 16L, 16R are simultaneously moved to the front position E, respectively.
Or to the reverse position.

Next, the function of the travel control device 51 will be described. First, when operating the pair of left and right pedal devices 7L and 7R, the pair of pilot switching valves 16L and 16R perform the same switching work as in the related art. However, when the hydraulic excavator (not shown, but a crawler vehicle equipped with the travel control device 51) is to be moved forward, the changeover switch 58 is operated to the F position to operate the one-way operation pedal device 52. Since the forward / reverse selection valve 55 has been switched to the forward position W, the pilot pressure hydraulic source 37
Pilot pressure from pilot valve 54, forward / backward selection valve
55 position, passing line 60, one line 43, shuttle valve
38, via a pipeline 44, acts on the pilot pressure receiving portion 27 of the pilot switching valve 16L. At the same time, the pilot pressure branches off in the line 60, and acts on the pilot pressure receiving portion 29 of the pilot switching valve 16R through the line 45, the shuttle valve 40, and the line 46. The pilot switching valves 16L and 16R are simultaneously switched to the forward e position and the forward position, respectively. To move the vehicle backward, the changeover switch 58 is operated to the R position to operate the one-way operation pedal device 52. Forward / reverse selector valve
Since 55 is switched to the reverse position, the pilot switching valves 16L and 16R are simultaneously switched to the reverse position and the H position, respectively, in a manner reverse to that of the front and rear cases.

Therefore, by operating the changeover switch 58 and the one-way operation pedal device 52, the hydraulic excavator can travel straight ahead or in the direction.

(4) FIG. 4 is a perspective view showing a travel control device 61 of a fourth embodiment according to the present invention. In the drawing, 62L and 62R are left and right tread members of the travel control device 61, and 63 is a straight traveling operation unit (FIG. 4) formed so that the driver can simultaneously step on the tread members 62L and 62R in the same direction with one foot. , 64L and 64R are running levers fixed to the tread members 62L and 62R, respectively, and 65 is a bracket rotatably supporting the tread members 62L and 62R, respectively. Next, the configuration of the travel control device 61 of the fourth embodiment will be described with reference to FIG. A straight traveling operation section 63 is formed so that the driver can simultaneously operate the pair of left and right tread members 62L and 62R in the same direction with one foot, and when the vehicle is performing straight traveling, the driver can use the one foot for the straight traveling. When the vehicle changes the traveling direction, the pair of left and right tread members 62 are used.
It is configured to perform a stepping operation of a required tread member among L and 62R.

Next, the function of the travel control device 61 will be described. When performing a stepping operation on a required tread member of the pair of left and right tread members 62L and 62R, the same operation as in the related art can be performed. When the driver steps on the straight traveling operation unit 63 with one foot, the vehicle can travel straight.

Effect of the Invention In the travel control device for a construction machine according to the present invention, since the straight-movement-only pedal device is provided, the construction machine can travel straight ahead accurately by depressing the straight-movement-only pedal device with one foot. Even if the driver manually operates the work operation lever during the straight running, there is no need to concentrate the nerves on both feet as in the prior art, so the workability and drive operability of a construction machine, for example, a hydraulic shovel. Can be improved. In addition, when the traveling direction is changed, a pedal device dedicated to straight traveling is not used, but the traveling operation can be performed in the same manner as in the related art.

Further, detecting means for detecting the operation state of the straight-ahead pedal device, a controller to which a detection signal from the detecting means is input, and an engine rotation command signal output from the controller based on the detection signal are input. If the governor of the engine is provided, it is possible to automatically obtain an engine speed suitable for the straight traveling during the operation of the construction machine in conjunction with the depression operation of the pedal device for straight traveling.

Further, a detecting means for detecting an operation state of the pedal device for straight ahead, a controller to which a detection signal from the detecting means is input, and a traveling speed switching operation command signal output from the controller based on the detection signal. If the traveling speed switching means for adjusting the rotation speed of the traveling motor is provided, the traveling speed suitable for the straight traveling at the time of the operation of the construction machine is automatically adjusted in conjunction with the depression operation of the straight traveling dedicated pedal device as described above. For example, when the excavator moves straight back and forth in a short distance while performing excavation work, the excavator is automatically adjusted to a preset traveling speed, so that trench excavation work or deep hole excavation work can be performed. Convenient and secure.

Furthermore, if the pedal device for straight traveling can be operated only in one direction and the switching means for switching between forward and backward is provided,
Depressing operation of the pedal device for straight ahead becomes easy.

As described above, according to the present invention, the straight traveling operation of the construction machine can be facilitated, and the workability can be improved.

[Brief description of the drawings]

FIG. 1 is a main part circuit diagram showing a travel control device of a first embodiment according to the present invention, FIG. 2 is a main circuit diagram showing a travel control device of a second embodiment according to the present invention, and FIG. FIG. 4 is a main part circuit diagram showing a travel control device according to a third embodiment of the present invention; FIG. 4 is a perspective view showing a travel control device according to a fourth embodiment of the present invention; FIG. 6 is a perspective view showing the vicinity of a driver's seat of a hydraulic shovel provided with a hydraulic shovel, and FIG. 6 is a main part circuit diagram of the hydraulic shovel provided with a conventional traveling control device. _{3 L, 3 R, 34,53,62 L} , 62 R ...... tread 7 _L, 7 _R ...... pedal member 8～11,35,36,54 ...... pilot valve 12 _L, 12 _R ...... running motor 16 _L , 16 _R …… Pilot changeover valve 25,25 ′ …… Controller 32,47,51,61 …… Traveling control device 33 …… Pedal device only for straight ahead 37 …… Pilot pressure hydraulic source 53 …… One-way operation Pedal unit 58… Changeover switch 63… Operation unit for straight running

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁶ , DB name) E02F 9/20 F term 3J070

Claims (4)

(57) [Claims] 1. A pair of pedal devices, a pair of pilot pressure deriving means for deriving a pilot pressure corresponding to a forward or reverse operation of the pair of pedal devices, and switching by a pilot pressure from the pair of pilot pressure deriving devices. In a travel control device for a construction machine having a pair of pilot switching valves to be controlled and left and right traveling motors operated and controlled by switching control of the pair of pilot switching valves, a straight-only pedal device; A pilot pressure deriving means for deriving a pilot pressure by operation, and selecting one of the pilot pressure from the pair of pilot pressure deriving means and the pilot pressure from the linear driving dedicated pilot pressure deriving means. To act on the pilot pressure receiving portion of the pair of pilot switching valves. And a travel control device for a construction machine. 2. A detecting means for detecting an operation state of the pedaling device, a controller to which a detection signal from the detecting means is input, and an engine rotation command signal output from the controller based on the detection signal. The travel control device for a construction machine according to claim 1, further comprising: a governor of the engine to which the input is input. 3. A detection means for detecting an operation state of the pedal device for straight ahead, a controller to which a detection signal from the detection means is inputted, and a traveling speed switching operation outputted from the controller based on the detection signal. The traveling control device for a construction machine according to claim 1 or 2, further comprising traveling speed switching means for adjusting a rotation speed of the traveling motor according to a command signal. 4. The straight-moving pedal, comprising: a forward / reverse selecting valve provided in a conduit communicating the straight-moving dedicated pilot pressure deriving means with the pilot switching valve; and switching means for controlling the forward / removing selecting valve. The device is a one-way operation pedal that can be operated only in one direction, and the straight-movement dedicated pilot pressure deriving means derives pilot pressure only in a single direction by operating the one-way operation pedal, and performs the forward / reverse switching. The travel control device for a construction machine according to claim 1, wherein the valve is capable of switching the direction of the pilot pressure.