JPH08158410A - Automatic changing structure for accelerator position of working vehicle - Google Patents

Abstract

PURPOSE: To save the fuel by furnishing hydrarulic actuator, control valve, manually operating tools, accel. operating tool, actuation sensor, and a fixing means. CONSTITUTION: When a hydraulic actuator is in operation, the accelerator 39 for an engine 8 is automatically shifted to the position corresponding to the operated position of an accel. operating tool 42, and when the actuator is stopped, the accelerator 39 is shiffted automatically to the first low-speed position on the idling side. A fixing means 46 is furnished which can manually fix and disengage manually operating tools 9, 10 in the neutral position corresponding to the stopped position of the hydraulic actuator, and if this means 46 is turned to the stationary side, the accelerator 39 is automatically shifted to the second low-speed position an normal which lies still lower than the first low-speed position. Thus the fuel can be saved by this shift of the accelerator 39 at temporary interruption of the works when the operating tools 9, 10 are fixed in the neutral position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for automatically changing the position of an accelerator of an engine in a work vehicle configured to drive and operate a working unit provided in a machine body.

[0002]

2. Description of the Related Art In a backhoe for civil engineering construction, which is an example of a work vehicle as described above, a hydraulic cylinder (corresponding to a hydraulic actuator) for driving and operating a backhoe device (corresponding to a working unit) provided in the machine body, The control valve that supplies and discharges the hydraulic oil from the pump that is driven by the engine to the hydraulic cylinder, the operation lever that switches this control valve (corresponding to an artificial operation tool), and the position of the accelerator of the engine are set. It is equipped with an accelerator lever (corresponding to an accelerator operation tool).

In the backhoe having such a structure, a position sensor (corresponding to an actuation sensor) for detecting the operation position of the operation lever is provided, and when the operation lever is operated to the neutral position (the hydraulic cylinder is in a stopped state). , If the accelerator position is automatically changed to a position slightly higher than the idling position and the operating lever is moved to the operating position (hydraulic cylinder operating state), the accelerator position is set to the accelerator lever operating position. There is one that is configured to automatically change to a position corresponding to.

As described above, when the hydraulic actuator is in a stopped state, the fuel is saved and the noise is reduced by dropping the accelerator position to near the idling position.
When the hydraulic actuator is stopped, the accelerator position can be changed to a position slightly higher than the idling position by dropping the accelerator position to the idling position, and when the hydraulic actuator starts operating next time, This is because it takes time to return the accelerator position to the position corresponding to the original operation position of the accelerator lever.

[0005]

With the above-described structure, regardless of whether the work is resumed immediately when the hydraulic actuator is stopped, or when the hydraulic actuator is left in a stopped state for a certain period of time, etc. , The engine's accelerator position is changed to a position slightly higher than the idling position. As a result, there is room for improvement in terms of fuel saving and noise reduction, especially when the hydraulic actuator is left in a stopped state for a certain period of time. As described above, the present invention provides a structure for automatically changing the position of the accelerator of the engine according to the operating state and the stop state of the hydraulic actuator. The purpose is to reduce noise.

[0006]

The feature of the present invention resides in the following structure in the structure for automatically changing the accelerator position of the work vehicle as described above. That is, [1] a hydraulic actuator for driving and operating a working unit provided in the machine body, a control valve for supplying and discharging hydraulic oil from a pump driven by an engine provided in the machine body to the hydraulic actuator, and a control valve. It is equipped with an artificial operation tool that is operated by switching and an accelerator operation tool that is operated artificially by setting the position of the accelerator of the engine, and whether or not the hydraulic actuator is operating. When the hydraulic actuator is operating, it is equipped with an actuation sensor for detecting and a fixing means for artificially fixing and releasing the fixing of the manual operation tool at the neutral position corresponding to the stopped state of the hydraulic actuator. If the hydraulic actuator is stopped by automatically changing the position to the position corresponding to the operating position of the accelerator operation tool, the engine First control means for automatically changing the position of the engine to the first low speed position on the idling position side, and when the fixing means is operated to the fixed side, the accelerator position of the engine is changed to the first position.
Second control means for automatically changing to a second low speed position which is further lower than the low speed position is provided.

[2] In the configuration of the above item [1], when the set time elapses after the hydraulic actuator is stopped in the state where the fixing means is operated to the fixing release side, the position of the accelerator of the engine is set to the first low speed. There is provided third control means for automatically changing to a third low speed position which is a speed lower than the position.

[0008]

[Action]

[I] When configured as in the above item [1], as shown in FIG. 1, for example, in a state in which the accelerator operation tool 42 (accelerator lever) is operated to a certain operation position m1, the accelerator 3 is operated.
The position 9 is changed to the first low speed position M1 on the idling position A side. In this state, when the hydraulic actuator switches from the stopped state to the activated state (time point B
1), the position of the accelerator 39 is automatically changed from the first low speed position M1 to the position M4 corresponding to the operating position m1 of the accelerator operating tool 42, and the hydraulic actuator is switched from the operating state to the stopped state. And (points B2, B
3), the position of the accelerator 39 is changed from the position M4 to the first low speed position M1. In this case, by setting the first low speed position M1 to be slightly higher than the idling position A, when the hydraulic actuator is switched from the stopped state to the activated state, the accelerator operation is performed without delaying the position of the accelerator 39. The operation is changed to the position M4 corresponding to the operation position m1 of the tool 42.

A work vehicle such as a backhoe is provided with a fixing means capable of fixing a manual operation tool for a hydraulic actuator at a neutral position, and the work is interrupted while the hydraulic actuator is stopped so that the worker exits the driving section. At this time, the manual operation tool may be fixed at the neutral position by the above-mentioned fixing means. According to the constitution as described in the above item [1], it is judged that if the manual operation tool is fixed at the neutral position by the fixing means, the work is interrupted and the hydraulic actuator is left in a stopped state for a certain time. Therefore, in such a case, for example, as shown in FIG.
The position 9 is changed from the above-described first low speed position M1 to the second low speed position M2 on the further low speed side (time point B9).

[II] When configured as in the above item [2],
As in the case of the configuration of the above [1], the "action" described in the above [I] is provided, and in addition to this, the following "action" is provided. In a work vehicle such as a backhoe, as described in the above item [I], the human-operated operation tool for the hydraulic actuator is fixed at the neutral position by the fixing means so that the operator can drive the operation unit without leaving the operation unit. There is also a case where the operator sits down and leaves the manual operation tool in the neutral position and then temporarily stops the work.

With this configuration, according to the above-mentioned [2], even if the artificial operating tool is not fixed at the neutral position by the fixing means, after the hydraulic actuator is stopped (the artificial operating tool is operated to the neutral position, When the set time elapses, it is determined that the work is paused, and the position of the accelerator 39 is changed from the first low speed position M1 described above to the third low speed position M3 on the lower speed side, as shown in FIG. 1, for example. It is operated (time points B4 and B5).

[0012]

According to the first aspect of the present invention, there is provided a structure for automatically changing the accelerator position of a work vehicle, which is configured to automatically change the position of the accelerator of the engine in accordance with the operating and stopped states of the hydraulic actuator. When the work is temporarily suspended such that the manual operation tool is fixed at the neutral position, the accelerator position is changed to the second low speed position which is lower than the normal first low speed position to further save fuel. And it was possible to reduce the noise.

According to the second aspect of the invention, as in the case of the first aspect, the above-mentioned "effect of the invention" is provided. According to the second aspect of the invention, when the work is temporarily stopped even if the manual operation tool is not fixed at the neutral position, the accelerator position is set to a speed lower than the normal first low speed position. By changing the operation to the third low speed position, it was possible to further save fuel and reduce noise.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 shows the entire side surface of a backhoe which is an example of a work vehicle. A swivel base 2 is supported by a rubber crawler type traveling device 1, and a backhoe device 3 (corresponding to a working unit) is provided in front of the swivel base 2. It is equipped. The backhoe device 3 includes a boom 4 vertically rocked by a hydraulic cylinder 11 (corresponding to a hydraulic actuator), an arm 5 rocking back and forth by a hydraulic cylinder 12 (corresponding to a hydraulic actuator), and a hydraulic cylinder 13 (hydraulic cylinder). The bucket 6 is swingably driven back and forth by an actuator (corresponding to an actuator). A swing bracket 14 that supports the entire backhoe device 3 is swingably driven by a hydraulic cylinder 7 around a vertical axis P at the front of the swivel base 2.

Next, the hydraulic circuit of the backhoe will be described. As shown in FIG. 2, with respect to the first pump 15 (corresponding to the pump of the present invention) driven by the engine 8, a control valve 2 for the hydraulic motor (not shown) of the right traveling device 1 is provided.
6, a control valve 22 for the hydraulic cylinder 12 of the arm 5 (corresponding to the control valve of the present invention), and a control valve 27 for the service port (not shown) are connected in parallel. Second pump 16
A control valve 28 for the hydraulic motor (not shown) of the traveling device 1 on the left side (corresponding to the pump of the present invention) and a control valve 21 for the hydraulic cylinder 11 of the boom 4 (corresponding to the control valve of the present invention). , A control valve 23 for the hydraulic cylinder 13 of the bucket 6
(Corresponding to the control valve of the present invention) are connected in parallel.
A control valve 24 for a hydraulic motor (not shown) of the swivel base 2 with respect to the third pump 17 (corresponding to the pump of the present invention), and a control valve 2 for a hydraulic cylinder 7 for rocking the backhoe device 3.
5. A control valve 29 for a hydraulic cylinder (not shown) for raising and lowering the dozer 19 shown in FIG. 3 is connected in parallel.

The control valves 21 to 29 are of the center bypass type, and the control valves 26 and 28 for the traveling device 1, the control valve 27 for the service port, and the control valve 29 for the dozer 19 are operating levers (not shown). It is a mechanically operated and neutral return type. The control valve 25 for swinging the backhoe device 3 is also a center bypass type, and is a mechanically operated neutral return type operated by an operation pedal (not shown). Control valve 21 for boom 4 and control valve 2 for arm 5
2, the control valve 23 for the bucket 6 and the control valve 24 for the swivel base 2 are pilot-operated type and neutral return type, and the opening degree of the control valves 21-24 is changed by changing the pilot pressure. The operating speeds of the hydraulic cylinders 11, 12, 13 and the hydraulic motor can be changed.

Next, the control valve 21 for the backhoe device 3,
The operation structure of the control valves 24 for the swivel bases 22 and 23 will be described. As shown in FIGS. 2 and 3, the swivel base 2
A right operation lever 9 (corresponding to an artificial operation tool) and a left operation lever 49 (corresponding to an artificial operation tool) that can be operated in the front, rear, left, and right directions are provided on both sides of the driver's seat 30 in the driving section 20 of FIG. A pair of pilot valves 31 that generate a pilot pressure by operating the right operation lever 9 forward and backward and a pair of pilot valves 32 that generate a pilot pressure by operating right and left are provided. A pair of pilot valves 33 that generate pilot pressure by operating the left operation lever 10 forward and backward, and a pair of pilot valves 34 that generate pilot pressure by operating left and right.
And a pilot pump 18 for supplying pilot pressure to each of the pilot valves 31 to 34.

A pair of pilot oil passages 35 from the pilot valve 31 of the right operation lever 9 are connected to the control valve 21 for the boom 4.
And a pair of pilot oil passages 36 from the pilot valve 32 are connected to the control valve 23 for the bucket 6. A pair of pilot oil passages 37 from the pilot valve 33 of the left operating lever 10 are connected to the control valve 22 for the arm 5, and a pair of pilot oil passages 3 from the pilot valve 34.
8 is connected to the control valve 24 for the swivel 2.

As a result, when the right operation lever 9 is operated back and forth, the control valve 21 is switched by the pilot pressure from the pilot valve 31, and the boom 4 is swung up and down by the hydraulic cylinder 11 so that the right operation lever 9 is moved. Is operated left and right, the control valve 23 is switched by the pilot pressure from the pilot valve 32, and the bucket 6 is rocked back and forth by the hydraulic cylinder 13. When the left operation lever 10 is operated back and forth, the control valve 22 is switched by the pilot pressure from the pilot valve 33, and the hydraulic cylinder 12
The arm 5 is driven to swing back and forth by the left operation lever 1
When 0 is operated to the left or right, the control valve 24 is switched by the pilot pressure from the pilot valve 34, and the swivel base 2 is driven to the right and left swivel sides.

In this case, by changing the operation amount of the right and left operation levers 9 and 10 from the neutral position to large or small, the pilot pressure from the pilot valves 31 to 34 is changed to large or small to control the control valves 21 to 24. Change the opening of
The operating speeds of the hydraulic cylinders 11, 12, 13 and the hydraulic motor can be arbitrarily changed to the operating speeds corresponding to the operating positions of the right and left operating levers 9, 10.

Next, the operation of the accelerator 39 of the engine 8 will be described. As shown in FIG. 2, the position of the accelerator 39 of the engine 8 is set to the idling position A and the maximum speed position M.
(See FIG. 1), a motor 40 for changing and operating the motor 40, and a control device 41 for operating and operating the motor 40 are provided, and an accelerator lever 42 (corresponding to an accelerator operating tool) that is manually operated is operated. The position is input to the control device 41.

The pilot pressures from the respective pilot oil passages 35 to 38 are collected together by the shuttle valve 43 and the pilot oil passage 44, and are sent to the pressure sensor 45 (corresponding to an operation sensor). A signal from the pressure sensor 45 is input to the control device 41. As a result, when the right and left operation levers 9 and 10 are operated to the neutral position, pilot pressure is not generated from each pilot valve 31 to 34, and therefore, if a signal is not input from the pressure sensor 45 to the control device 41, the backhoe is not operated. It can be determined that the hydraulic cylinders 11, 12, 13 of the device 3 and the hydraulic motor of the swivel base 2 are stopped. On the contrary, when the right or left operation lever 9, 10 is operated from the neutral position, pilot pressure is generated from at least one pilot valve 31 to 34, and the pressure sensor 45 detects this and generates a pilot pressure. When the signal is input to the control device 41, it can be determined that the hydraulic cylinders 11, 12, 13 of the backhoe device 3 or the hydraulic motor of the swivel base 2 is operating.

A lock mechanism 46 (corresponding to a fixing means) for fixing the right and left operation levers 9 and 10 by forcibly returning them to the neutral position (corresponding to the stopped state of the hydraulic cylinder 11).
Is provided on each of the right and left operation levers 9 and 10, and is provided with a lock lever 47 for switching both lock mechanisms 46 between a fixed state and a released state.
The operating position of is input to the control device 41.

With the above structure, as shown in FIG. 1, the lock lever 47 is operated to the unlocking side so that the accelerator lever 42 is released.
If both the right and left operation levers 9 and 10 are operated to the neutral position in the state where is operated to a certain operation position m1 (a signal from the pressure sensor 45 is not input),
The position of the accelerator 39 (rotational speed of the engine 8) is changed to a first low speed position M1 slightly higher than the idling position A.

In this state, when the right or left operating levers 9 and 10 are operated from the neutral position to start raising and lowering the boom 4 or the like (time B1), a signal from the pressure sensor 45 is input to the control device 41. Therefore, the position of the accelerator 39 is immediately changed from the first low speed position M1 to the accelerator lever 4
The engine 8 and the first, second, third pumps 15, 16, 17 are operated at the position M4 corresponding to the second operation position m1 to increase the rotational speed.

When the right and left operating levers 9 and 10 are returned to the neutral position (time B2), the pressure sensor 4
Since the signal from 5 is not input, the first set time T
After the lapse of 1, the position of the accelerator 39 is changed from the position M4 to the first low speed position M1 (time point B3), and the engine 8
Also, the rotational speeds of the first, second, third pumps 15, 16 and 17 decrease (the above corresponds to the first control means). In this case, the right and left operation levers 9 and 10 are returned to the neutral position to perform the first operation.
If the right and left operation levers 9 and 10 are operated again before the set time T1 elapses, the position of the accelerator 39 is left at the initial position M4 and is not changed to the first low speed position M1. .

In the state where the lock lever 47 is operated to the release position as described above, the right and left operation levers 9,
10 is returned to the neutral position and the position of the accelerator 39 is changed to the first low speed position M1 (at the time point B
3) If the state in which the right and left operation levers 9 and 10 are operated to the neutral position (the state in which the signal from the pressure sensor 45 is not input) is maintained for the second set time T2 (corresponding to the set time), the work is performed. It is determined to have been paused (time point B4).
As a result, the position of the accelerator 39 is linearly changed to the low speed side, and is changed to the third low speed position M3 which is lower than the first low speed position M1 (slightly higher speed side than the idling position A). (Time point B5) (corresponding to the third control means).

When the position of the accelerator 39 is thus changed to the third low speed position M3 and the right or left operating levers 9 and 10 are operated from the neutral position, the boom 4 is moved up and down. At time B6), similarly to the above, the position of the accelerator 39 is immediately changed from the third low speed position M3 to the position M4 corresponding to the operation position m1 of the accelerator lever 42, and the right and left operation levers 9 and 10 are operated. When returning to the neutral position (time point B7), the first set time T
After the lapse of 1, the position of the accelerator 39 is changed from the position M4 to the first low speed position M1 (time point B8). in this case,
While the position of the accelerator 39 is being changed from the first low speed position M1 to the third low speed position M3 (from time point B4 to time point B5), if the right or left operation lever 9, 10 is operated from the neutral position, The position of the accelerator 39 is immediately changed to the position M4 corresponding to the operation position m1 of the accelerator lever 42.

Next, the lock lever 47 shown in FIG. 2 is switched from the release position to the fixed position, and the right and left operating levers 9 and 10 are forcibly returned to the neutral position and fixed (time B9). Based on the switching operation of the lock lever 47, the position of the accelerator 39 is immediately changed to the second low speed position M2 which is lower than the first low speed position M1 (slightly higher speed side than the idling position A) (second speed). Equivalent to control means). In this case, the third low speed position M3 and the second low speed position M2 described above are set at substantially the same position, or the second low speed position M2 is set slightly lower than the third low speed position M3. Since the resonance point of the engine 8 exists at a position slightly higher than the idling position A, the first low speed position M1 is located at a higher speed side than the resonance point and the second and third low speed positions M2 and M2 are located so as to avoid this resonance point. M3 is set to a lower speed side than the resonance point.

[Other Embodiments] In the above-described embodiment, the operation and stop of the hydraulic cylinder 11 and the like are determined by the pilot pressure, but the operation and stop of the hydraulic cylinder 11 and the like are controlled by the control valves 21 to 24 in FIG. The determination may be made in the operating state, or the operation of the boom 4 or the like or the hydraulic cylinder 11 or the like may be directly detected by a potentiometer or the like to make the determination.

In the configuration of FIG. 1, the lock lever 47
When the second set time T2 elapses when the right and left operation levers 9 and 10 are returned to the neutral position while the is operated to the release position, the position of the accelerator 39 is linearly changed to the third position.
Although it is configured to change to the low speed position M3, the above-described set time (time B3 to time B5) elapses as shown by the alternate long and short dash line in FIG. 1 with a set time between time B3 and time B5. Then, the position of the accelerator 39 may be immediately changed to the third low speed position M3.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a diagram showing a temporal relationship among a pressure sensor, an accelerator lever operation position, an accelerator position, and a lock lever operation position.

FIG. 2 is a hydraulic circuit diagram showing a linked state of a hydraulic cylinder for a backhoe device, an operating lever, an accelerator of an engine, and the like.

[FIG. 3] Overall side view of the backhoe

[Explanation of Codes] 3 Working unit 8 Engine 9,10 Human operation tool 11,12,13 Hydraulic actuator 15,16,17 Pump 21,22,23 Control valve 39 Accelerator 42 Accelerator operation tool 45 Actuation sensor 46 Fixing means A Idling Position m1 Operation position of accelerator operation tool M1 First low speed position M2 Second low speed position M3 Third low speed position M4 Position corresponding to operation position of accelerator operation tool T2 Set time

Claims (2)

[Claims] 1. Hydraulic actuators (11), (12), (1) for driving and operating a working unit (3) provided in the machine body.
3) and hydraulic oil from pumps (15), (16) and (17) driven by an engine (8) provided in the machine body are supplied to the hydraulic actuators (11), (12) and (13). Control valves (21), (22), (23) for discharging operation,
An artificial operation tool (9), (1) that is operated by switching the control valves (21), (22), (23).
0) and an accelerator operation tool (42) for artificially operating the position of the accelerator (39) of the engine (8), and the hydraulic actuators (11), (12), ( 13)
Sensor (45) to detect whether or not the
And the hydraulic actuators (11), (12), (1
The hydraulic actuators (11), () are provided with a fixing means (46) capable of artificially fixing and releasing the artificial operation tools (9), (10) at a neutral position corresponding to the stopped state of (3). 12), (13)
Is operating, the accelerator (3) of the engine (8) is
9) is automatically changed to a position (M4) corresponding to the operation position (m1) of the accelerator operation tool (42), and the hydraulic actuators (11), (12), (1)
When 3) is stopped, first control means for automatically changing the position of the accelerator (39) of the engine (8) to the first low speed position (M1) on the idling position (A) side, When the fixing means (46) is operated to the fixed side, the position of the accelerator (39) of the engine (8) is set to a second low speed position (M) lower than the first low speed position (M1).
2) A structure for automatically changing the accelerator position of a work vehicle, which is provided with a second control means for automatically changing the operation. 2. When a set time (T2) elapses after the hydraulic actuators (11), (12), (13) are stopped in a state where the fixing means (46) is operated toward the fixing release side. And a third control means for automatically changing the position of the accelerator (39) of the engine (8) to a third low speed position (M3) which is lower than the first low speed position (M1). The structure for automatically changing the accelerator position of a work vehicle according to claim 1.