JPH09242568A - Motor speed control device - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] The operability is greatly improved by detecting the rotational displacement of a rotary mechanism that is displaced according to the operation amount of a direct-acting lever and a foot pedal, by a potentiometer. Therefore, the number of rotations of the prime mover can be smoothly controlled. A rotating mechanism 19 includes a lever-side rotating body 20 connected to a direct-acting lever 14, a pedal-side rotating body 26 connected to a foot pedal 15, and a lever-side rotating body 20 to a pedal-side rotating body 26. And a displacement transmission unit 36 that transmits the rotational displacement. When the direct acting lever 14 is tilted, the lever-side rotating body 20 is rotationally displaced, and this displacement is transmitted to the pedal-side rotating body 26 via the displacement transmitting portion 36. As a result, the pedal-side rotating body 26 rotates, and the detection lever 37 of the potentiometer 37 is connected via the link 38.
Rotate A. When the foot pedal 15 is depressed, only the pedal-side rotating body 26 is rotationally displaced, and the detection lever 37A is rotated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation speed control device for a prime mover which is provided in a construction machine such as a hydraulic excavator and is suitable for controlling the rotation speed of a prime mover such as a diesel engine.

[0002]

2. Description of the Related Art Generally, for construction machines such as hydraulic excavators, a diesel engine is widely used as a prime mover. By rotating a governor lever of a governor attached to the diesel engine, an injection amount of fuel supplied to the engine is increased. , And the rotational speed is variably controlled.

In this type of conventional hydraulic excavator, an upper revolving structure is rotatably mounted on a lower traveling structure traveling by a traveling motor via a revolving device such as a revolving motor. A machine room accommodating a prime mover, a hydraulic pump, and the like, a driver's room in which a driver of the hydraulic excavator boards, and the like are provided. A work device including a boom, an arm, a bucket, and the like is provided at the front of the upper swing body, and hydraulic cylinders are provided on the boom, the arm, the bucket, and the like.

Here, these hydraulic cylinders and actuators such as a traveling motor and a swing motor are respectively connected to a hydraulic system using the hydraulic pump as a hydraulic source, and the hydraulic pump is driven by a prime mover, so that the hydraulic pump is driven. Is supplied to each actuator via each hydraulic system. The driver's cab is provided with a plurality of operating levers for operating the actuators, a foot pedal (accelerator pedal), and the like, and the driver operates these to rotate the boom, arm, bucket, and the like ( It is used to excavate earth and sand by turning it up and down, turning and running.

In addition to the above-mentioned operating lever and the like, a direct-acting lever (fuel lever or the like) for setting and operating the number of revolutions of the prime mover is provided in the cab, and the direct-acting lever is provided via a control cable or the like. It is connected to the governor (governor lever) of the prime mover housed in the machine room. When the driver manually tilts the direct-acting lever, the governor lever is rotated at a rotation angle corresponding to the tilt angle, and the injection amount of fuel supplied to the prime mover is increased or decreased accordingly. As a result, the rotation speed of the prime mover changes.

Therefore, the driver can variably control the rotation speed of the prime mover by the direct-acting lever according to the working (operating) condition while the hydraulic excavator is operating, and for example, excavation work with high load is performed. At times, by holding the prime mover at a high rotation speed with a direct-acting lever, a large amount of pressure oil is supplied from the hydraulic pump to each hydraulic cylinder of the working device, and the boom,
A large driving force is applied to the arm, the bucket, etc., and these can be operated at high speed even under a high load condition. In addition, low-load work (operation), such as turning the upper revolving structure
When performing, the work (turning) speed can be reduced and fuel consumption and noise can be suppressed by keeping the prime mover at a low rotation speed.

[0007]

By the way, in the above-mentioned prior art, when excavating or the like with a hydraulic excavator, for example, the upper revolving structure is accommodated in a bucket containing earth and sand excavated in front of the vehicle body. In many cases, the work is performed by turning and stacking the earth and sand on the side or rear of the vehicle body, and the excavating operation and the turning operation are often performed continuously. In this case, the driver performs the excavation operation at high speed in order to improve work efficiency, while the turning operation tries to perform at low speed in order to avoid collision with surrounding obstacles and the like. However, in the hydraulic excavator according to the conventional technology, when the excavation work and the turning motion are continuously performed in this way, the driver releases the operating lever one by one to move the direct-acting lever between the high speed side and the low speed side. Since it has to be switched, the operability deteriorates.

On the other hand, as a method of solving such a problem, by connecting a foot-operated pedal together with a direct-acting lever to a governor lever, instead of a driver manually operating the direct-acting lever, It has been proposed that the rotational speed of the prime mover can be variably set by operating the type pedal.

In this case, the foot-operated pedal is connected with a rotating mechanism which is rotationally displaced in accordance with the amount of depression operation, and this rotating mechanism is connected to the governor lever via a control cable. The direct-acting lever is connected to the rotating mechanism so that the rotating mechanism is rotationally displaced in accordance with the operation amount of the direct-acting lever, separately from the rotational displacement by the foot pedal.
That is, when the direct acting lever and the foot pedal are operated,
The rotating mechanism is rotationally displaced according to the sum of these operation amounts, and in response to this, the governor lever is rotated via the control cable.

As a result, the driver can variably set the rotation speed of the prime mover by operating either the direct-acting type lever or the foot pedal, so that excavation work can be performed while operating each operating lever with both hands. Even during the turning operation or the like, by operating the foot pedal, the number of revolutions of the prime mover can be changed without releasing the hands from the operation levers.

However, in the case of such a structure, since the rotation mechanism is always connected to the foot pedal and the governor lever, the rotation mechanism is rotationally displaced by operating, for example, a direct-acting lever. In order to operate the rotary mechanism, it is necessary to rotate the rotation mechanism against the reaction force of the foot pedal and the reaction force of the governor lever. Therefore, it is necessary to tilt the direct drive lever with a large force. However, there is a problem that the operability of the direct acting lever is deteriorated.

Further, in the case where the excavation work and the turning motion are performed continuously, in order to change the rotation speed of the prime mover with the foot pedal, the excavation work and the turning motion are adjusted at the timing of transition. In order to smoothly change the rotation speed of the prime mover, it is necessary to delicately operate the foot pedal, but in the above-mentioned configuration, the foot pedal is mechanically attached to the governor lever via the rotation mechanism, control cable, etc. Since it is connected to the vehicle, it is necessary to step on the foot pedal with a relatively large force, and there is a problem that the rotational speed of the prime mover cannot be smoothly controlled like the accelerator pedal of an automobile, for example.

The present invention has been made in view of the above-mentioned problems of the prior art. The operability of the direct-acting lever and the foot pedal can be greatly improved, and the engine can be rotated by the direct-acting lever and the foot pedal. It is an object of the present invention to provide a rotation speed control device for a prime mover that can smoothly change the number.

[0014]

In order to solve the above-mentioned problems, the invention as set forth in claim 1 provides a prime mover, first operating means for variably setting and operating the number of revolutions of the prime mover, and the first operation. Means for connecting the second operating means, which is provided at a position different from the means for variably setting the rotational speed of the prime mover, and the first operating means and the second operating means, and is used to adjust the operation amount of the first operating means. And a rotation mechanism which is rotationally displaced according to the operation amount of the second operation means, and a rotation position of the rotation mechanism is detected as an operation amount of the first and second operation means. And a rotation speed control means for variably controlling the rotation speed of the prime mover according to the operation amount detected by the operation amount detection means.

With this structure, the rotating mechanism that is rotationally displaced according to the operation amount of one of the first and second operating means is further rotationally displaced according to the operation amount of the other. Therefore, by operating at least one of the first and second operating means, the rotating mechanism can be rotationally displaced according to the operation amount. Further, by operating the first and second operating means together, the rotating mechanism can be rotationally displaced to the rotational position according to the sum of the operation amounts of the first and second operating means. The rotation position of the rotating mechanism can be detected as the operation amount of the first and second operation devices by the operation amount detection device, and the rotation speed of the prime mover can be variably controlled by the rotation speed control device according to the operation amount. .

Further, in the invention described in claim 2, the rotating mechanism is a first rotating body which is connected to the first operating means side and is rotationally displaced according to an operation amount of the first operating means, A second rotating body which is connected to the second operating means side and is rotationally displaced according to an operation amount of the second operating means, and a rotation of the first rotating body provided between the first and second rotating bodies. The operation amount detecting means is configured to detect the rotational position of the second rotating body as the operation amount, the displacement transmitting means transmitting the displacement to the second rotating body.

Thus, the rotational displacement of the first rotating body, which is rotationally displaced according to the operation amount of the first operating means, can be transmitted from the first rotating body to the second rotating body by the displacement transmitting means. The displacement transmitting means allows the second rotating body to be rotationally displaced to the rotational position according to the operation amount of the first operating means. Then, the second rotating body can be further rotationally displaced from the rotational position according to the operation amount of the second operating means, and therefore, by operating at least one of the first and second operating means, the second rotating body is rotated. The body can be rotationally displaced to a rotational position corresponding to the sum of the operation amounts of the first and second operating means, and this rotational position can be detected by the operation amount detecting means as the operation amount of the first and second operating means. .

In the invention according to claim 3, the first operating means is a direct-acting lever that is manually tilted, and the second operating means is a foot-operated pedal that is depressed. The operation amount detecting means is composed of a potentiometer.

As a result, by manually tilting the direct-acting lever or stepping on the foot-operated pedal, the rotation mechanism is operated by the tilting operation amount of the direct-acting lever and the foot-operated pedal. It can be rotationally displaced to a rotational position that corresponds to the sum of the pedaling operation amount of, and this rotational position can be detected by a potentiometer, so it rotates according to the detected operation amount of the direct-acting lever and the foot pedal. The rotational speed of the prime mover can be variably controlled by the number control means.

Further, in the invention according to claim 4, the rotation speed control means includes a governor attached to the prime mover for changing the rotation speed of the prime mover according to a rotation angle of the governor lever, and a governor lever of the governor. It is composed of an electric motor to be rotated and a controller for driving and controlling the electric motor according to the operation amount detected by the operation amount detecting means.

As a result, the controller can drive and control the electric motor according to the operation amount of the first and second operation means detected by the operation amount detecting means, and the electric motor rotates the governor lever of the governor according to the operation amount. Since the governor can change the rotation speed of the prime mover in accordance with the rotation angle, the rotation type control means controls the rotation of the prime mover according to the operation amount of the first and second operating means. The number can be variably controlled.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings, taking as an example a case where it is applied to a small hydraulic excavator.

In the figure, 1 is an undercarriage, 2 is an upper revolving structure which is mounted on the lower traveling structure 1 via a revolving device (not shown) such as a revolving motor so as to be revolvable. Body 2
Includes a prime mover 11 and a hydraulic pump (not shown) described later.
A machine room 3 accommodating the like, a counterweight 4, a driver's cab 5 and the like are provided.

A work device 6 is provided at the front part of the upper revolving structure 2 so as to be able to move up and down, and is used for excavating earth and sand. The work device 6 includes a lower boom 7, an upper boom 8, an arm 9 and a bucket 10. , A boom cylinder 7A for driving them, an offset cylinder 8A, an arm cylinder 9A, a bucket cylinder 10A, etc., and each of the cylinders 7A to 10A is connected to a hydraulic system (not shown) using the hydraulic pump as a hydraulic source. Each is connected.

Reference numeral 11 denotes a prime mover housed in the machine room 3. The prime mover 11 is composed of a diesel engine or the like and serves as a drive source for the hydraulic pump. As shown in FIG. 4, the prime mover 11 is additionally provided with a governor 12 for controlling the rotation speed of the prime mover 11, and a governor lever 13 is rotatably attached to the governor 12. Then, by rotating the governor lever 13, the rotation speed of the prime mover 11 is increased or decreased according to the rotation angle.

Reference numeral 14 denotes a direct-acting type lever as the first operating means, and the direct-acting type lever 14 is mounted in the cab 5 in the vicinity of the driver's seat together with other operating levers (not shown). As shown in FIG. 2, the direct-acting lever 14 is integrally formed with an annular turning portion 14B on the base end side of the lever body 14A, and the turning portion 14B is attached via a turning shaft 14C. 14D is rotatably connected in a state where a predetermined rotation (sliding) resistance is given. The mounting portion 14D is fixed to the cab 5 side. And the direct-acting lever 14
Is operated by the driver manually tilting the lever body 14A, and even if the driver releases his / her hand from the lever body 14A, the rotation (sliding) resistance between the rotation portion 14B and the attachment portion 14D is increased. The tilted position is held by.

Reference numeral 15 denotes a foot-operated pedal as the second operating means, and the foot-operated pedal 15 is located at the foot of the driver's seat in the operator's cab 5 and pushed onto the floor plate 16 as shown in FIG. It is arranged so that it can be stepped on. And the foot pedal 15
Is provided with a rotary plate 15B projecting downward in the vertical direction on the base end side of the step plate 15A. The rotary plate 15B penetrates the floor plate 16 and extends from the front surface side to the rear surface side. 1
An intermediate portion of 5B is rotatably attached to the back surface side of the floor plate 16 via a rotation shaft 15C.

The spring mounting portion 1 is provided on the back side of the floor plate 16.
5D is formed to project, and the spring mounting portion 15D and the rotating plate 15 are formed.
The lower end side of B is connected via a spring 17, whereby the rotating plate 15B is urged by the spring 17 so that the lower end side approaches the spring mounting portion 15D. The foot pedal 15 is depressed by the driver against the elastic force of the spring 17 by depressing the depression plate 15A, and the maximum depression position at this time is projected on the floor plate 16. It is regulated by the stopper 18.

Reference numeral 19 is a direct-acting type lever 14 and a foot pedal 1
5 shows a rotation mechanism connected to the rotation mechanism 19. As shown in FIG. 2, the rotation mechanism 19 is a lever-side rotation body 2 as a first rotation body.
0 and a pedal-side rotating body 26 as a second rotating body described later.
And a later-described displacement transmission portion 36 provided between the lever-side rotating body 20 and the pedal-side rotating body 26.

As shown in FIG. 3, the lever-side rotating body 20 has a flange-shaped rotary displacement plate 22 projecting from the lower end of a cylindrical shaft insertion portion 21, and the rotary displacement plate 22. A part of the outer peripheral side of 22 is bent upward in the vertical direction to form a pushing plate 23,
An adjusting screw 24 is attached to the pushing plate 23. The rotary displacement plate 22 is connected to the rotary portion 14B of the direct-acting lever 14 via the control cable 25.

Reference numeral 26 denotes a pedal-side rotating body as a second rotating body. In the pedal-side rotating body 26, a flange-shaped rotary displacement plate 28 is formed on the lower end side of a cylindrical shaft insertion portion 27 so as to project therefrom. Is
A part of the outer peripheral side of the rotary displacement plate 28 is bent downward in the vertical direction to form a passive plate 29. Then, the rotational displacement plate 2
8 is connected to the lower end side of the rotating plate 15B of the foot pedal 15 via the pedal link 30, whereby the pedal-side rotating body 26 is biased in the direction of arrow A by the elastic force of the spring 17. The passive plate 29 is in contact with the pushing plate 23 of the lever-side rotating body 20.

Reference numeral 31 denotes a bracket portion that rotatably supports the lever-side rotating body 20 and the pedal-side rotating body 26. The bracket portion 31 has an L-shaped cross section and an upper bracket 32 as shown in FIG. It is composed of a U-shaped lower bracket 33 and is attached to the back surface side of the floor plate 16 via an upper bracket 32 as shown in FIG. The upper bracket 32 and the lower bracket 33 are the flat plate portion 32.
A and 33A are integrally fixed in a state of being opposed to each other, and shaft insertion holes 32B and 33B into which the rotation shaft 34 is inserted are concentric with the flat plate portions 32A and 33A with the vertical direction as an axis. Is formed in.

Here, the flat plate portion 32 of the upper bracket 32
2 is provided between A and the flat plate portion 33A of the lower bracket 33.
As shown in FIG.
6 are disposed above and below, and in this state, the support shaft 34 is
In the shaft insertion fitting portions 21 and 27 of the respective rotating bodies 20 and 26, and in the shaft insertion fitting holes 32B and 33B of the brackets 32 and 33 shown in FIG.
It is inserted in and inside. As a result, the lever-side rotating body 2
The pedal-side rotary body 26 is rotatably supported by the bracket portion 31 about the axis O in FIG. 3, and the push plate 23 of the lever-side rotary body 20 and the passive plate of the pedal-side rotary body 26 are also supported. In this state, the surfaces 29 are in contact with each other as indicated by the chain double-dashed line in FIG. Reference numeral 35 denotes a retaining member for retaining the support shaft 34 in the downward direction in FIG.

Reference numeral 36 denotes a displacement transmitting portion as a displacement transmitting means. As shown in FIG. 3, the displacement transmitting portion 36 is a pushing plate 23 of the lever side rotating body 20 and a pedal abutting the pushing plate 23. It is composed of the passive plate 29 of the side rotating body 26.
When the lever-side rotating body 20 is rotationally displaced in the arrow B direction, the pushing plate 23 pushes the passive plate 29 in the circumferential direction, so that the pedal-side rotating body 26 moves in the arrow A'direction. The rotary displacement is performed, and the rotary displacement is transmitted from the lever-side rotary body 20 to the pedal-side rotary body 26. On the other hand, when the pedal-side rotating body 26 is rotationally displaced in the direction of the arrow A ′, the passive plate 29 rotates and separates from the pushing plate 23, so that only the pedal-side rotating body 26 rotates. Therefore, the rotational displacement is not transmitted from the pedal-side rotating body 26 to the lever-side rotating body 20.

Reference numeral 37 denotes a potentiometer as a manipulated variable detecting means. As shown in FIG. 3, the potentiometer 37 is provided with a detection lever 37A rotatably, and the detection lever 37A is connected to the pedal side via a link 38. Rotating body 2
6 is connected to the rotary displacement plate 28. Further, the potentiometer 37 is fixed to the lower bracket 33 and the upper bracket 32 at both left and right ends in FIG.
Then, the potentiometer 37 detects the rotational displacement of the pedal-side rotating body 26 via the detection lever 37A, and outputs a detection signal corresponding to this rotational displacement from the output terminal 37B to the controller 41 described later.

Reference numeral 39 denotes a rotation speed control unit as rotation speed control means. As shown in FIG. 4, the rotation speed control unit 39 rotates the governor 12 attached to the prime mover 11 and the governor lever 13 of the governor 12. It is composed of an electric motor 40 that is driven, a controller 41 that drives and controls the electric motor 40, and the like.

Here, the electric motor 40 is composed of, for example, a stepping motor or the like, and a turning lever 40A is rotatably provided, and the turning lever 40A is connected to the link 4A.
It is connected to the governor lever 13 of the governor 12 via 0B or the like. Then, the electric motor 40 is connected to the controller 41.
The rotating lever 40A is rotated in response to a drive signal input from the controller 40, whereby the governor lever 13 is rotated via the link 40B to increase or decrease the rotation speed of the prime mover.

Further, the controller 41 is composed of, for example, a microcomputer, the input side is connected to the potentiometer 37, the output side is connected to the electric motor 40, and a storage section (not shown) including ROM, RAM and the like is provided. There is. Then, the controller 41 calculates the turning angle of the turning lever 40A of the electric motor 40 based on the detection signal input from the potentiometer 37, and outputs a drive signal such as a pulse signal corresponding to the turning angle to the electric motor 40. Output to.

Reference numeral 42 denotes an idle changeover switch, which is arranged in the cab 5 and is connected to the input side of the controller 41. When the driver or the like operates the idle changeover switch 42, an operation signal is input to the controller 41, which causes the controller 41 to output a drive signal according to the operating condition to the electric motor 40, for example, a swing motor, a traveling motor. When the working hydraulic cylinders 7A, 8A, 9A, 10A, etc. are not all in operation, the controller 41 performs a no-load operation (auto idle) based on detection signals from operation detectors 44 to 46 described later. Then, the rotation speed of the prime mover 11 is automatically reduced to the minimum rotation speed (so-called idle rotation speed).

Reference numeral 43 denotes a saving operation changeover switch connected to the input side of the controller 41. When the saving operation changeover switch 43 is operated, the controller 41 sets the electric motor 40 in order to provide a predetermined limiter to the rotation speed of the prime mover 11.
The drive signal to be output to is restricted so that the rotation angle of the governor lever 13 is kept below a required angle. As a result, even if the driver operates the direct drive lever 14 or the foot pedal 15 to the maximum side, the rotational speed of the prime mover 11 is limited to a rotational speed lower than the maximum rotational speed by a fixed ratio.

Reference numerals 44, 45 and 46 denote operation detectors connected to the input side of the controller 41. The operation detectors 44
Numerals 46 to 46 detect whether or not the control valves for the swing motor, the traveling motor, and the work (none of which are shown) are switched from the neutral position to the switching position, and all of these control valves are in the neutral position. When the above condition is present, the controller 41 performs the determination process as the non-load operation based on the detection signals from the operation detectors 44 to 46 and the like.

In the hydraulic excavator of this embodiment constructed as described above, the driver manually tilts the operating lever or the like in the operator's cab 5 to operate the hydraulic cylinders 7A to 10A of the working device 6 and the like. Work such as excavation is performed by operating a swing motor or the like to rotate (raise or lower) the booms 7 and 8, the arm 9, the bucket 10 or the like, or rotate the upper swing body 2.

Then, for example, when continuously performing high-load excavation work, the driver manually tilts the direct-acting lever 14 to maintain the rotational speed of the prime mover 11 at the high speed side. In this state, the operating levers for the work device 6 can be operated, and the lower boom 7, the arm 9 and the like can be driven at high speed.
In addition, for example, when performing high-load work and low-load work alternately, the driver greatly depresses the foot pedal 15 during the high-load excavation work, so that the prime mover 11
The rotational speed of the prime mover 11 can be decelerated by decreasing the operation amount of the foot pedal 15 while the load is low, and the rotational speed of the prime mover 11 can be reduced. Accordingly, the rotation speed of the prime mover 11 can be changed.

The operation of the direct-acting lever 14 will now be described.
When A is tilted in the direction of arrow C in FIG. 3, the rotating portion 14B is rotated together with the lever main body 14A, whereby the lever-side rotating body 20 of the rotating mechanism 19 is moved to the direct-acting lever 14. It is rotationally displaced via the control cable 25 in the direction of arrow B according to the tilting operation amount. As a result, the pushing plate 23 of the lever-side rotating body 20 is moved to the passive plate 2 of the pedal-side rotating body 26.
9 is pushed in the direction of the arrow A ′ against the elastic force of the spring 17, the pedal-side rotating body 26 is pushed by the pushing plate 23 and the passive plate 29.
The lever-side rotary body 20 is rotationally displaced in the direction of the arrow A'according to the rotational displacement of the lever-side rotary body 20 in a state of being in contact with the lever-side rotary body 20 via the (displacement transmitting portion 36).

As a result, the detection lever 37A of the potentiometer 37 is connected to the pedal-side rotary member 2 via the link 38.
Since it is rotated in the direction of the arrow D with a rotation angle corresponding to the rotation displacement of 6, the potentiometer 37 outputs a detection signal corresponding to this rotation angle from the output terminal 37B to the controller 41. Then, the controller 41 outputs a drive signal corresponding to the detection signal from the potentiometer 37 to the electric motor 40 to rotate the rotating lever 40A of the electric motor 40, thereby rotating the governor lever 13 according to the detection signal. Then, the rotation speed of the prime mover 11 is increased or decreased. Therefore, the governor lever 13 is rotated according to the tilting operation amount of the direct-acting lever 14, and the rotation speed of the prime mover 11 is controlled accordingly.

Next, the operation of the foot pedal 15 will be described. When the driver does not step on the step plate 15A of the foot pedal 15, the spring 17 indicates the pedal side rotary member 26 as indicated by arrow E. Since it is biased in the direction (arrow A direction), the pedal-side rotating body 26 is in a state where the passive plate 29 is in contact with the pushing plate 23 of the lever-side rotating body 20.
It is positioned at the 0 rotation position.

When the driver steps on the stepping plate 15A in the direction of the arrow F in FIG. 3, the turning plate 15B turns together with the stepping plate 15A, and the pedal-side rotating body 26 passes through the pedal link 30. Is rotated in the arrow E'direction (arrow A'direction). As a result, the passive plate 29 of the pedal-side rotating body 26
Since the push plate 23 of the lever-side rotating body 20 is separated from
Only the pedal-side rotating body 26 is rotationally displaced in the direction of the arrow A ′ according to the amount of depression of the foot pedal 15. And
As with the direct acting lever 14, the potentiometer 3
7. The controller 41 and the electric motor 40 increase / decrease the rotational speed of the prime mover 11 according to the rotational displacement of the pedal-side rotating body 26.

Therefore, the pedal-side rotating body 26, which is rotationally displaced according to the operation amount of the direct acting lever 14, is further rotationally displaced from this rotational position according to the operation amount of the foot pedal 15. Therefore, the prime mover 11 is increased or decreased according to the sum of the operation amounts of the direct drive lever 14 and the foot pedal 15 by operating at least one of the direct drive lever 14 and the foot pedal 15. .

Thus, in this embodiment, the rotating mechanism 19 is connected to the direct acting lever 14 and the foot pedal 15, and the rotating mechanism 19 moves from the lever side rotating body 20 to the pedal side rotating body 2.
Since the rotational displacement is transmitted only to 6, the rotational displacement of the pedal-side rotary body 26 is detected by the potentiometer 37 without mechanically connecting the pedal-side rotary body 26 to the governor lever 13. By operating at least one of the direct-acting lever 14 and the foot-operated pedal 15, the driver can rotationally displace the pedal-side rotating body 26 in accordance with the amount of operation, and also the direct-acting lever 14 and the foot. When operating the foot pedal 15, the governor lever 1
The pedal-side rotating body 26 can be rotationally displaced without receiving the reaction force on the 3 side.

Therefore, the driver can smoothly operate the direct-acting lever 14 and the foot-operated pedal 15 with a comparatively small force, so that the manual direct-acting lever 14 and the foot can be operated according to the driving (work) situation. By properly using the pedal type pedal 15,
The rotation speed of the prime mover 11 can be appropriately controlled, the operability of the direct drive lever 14 and the foot pedal 15 can be reliably improved, and the steering stability of a hydraulic excavator or the like can be significantly improved.

Further, since the lever-side rotary body 20 is not rotationally displaced by the pedal-side rotary body 26, the driver depresses the foot pedal 15 to rotate only the pedal-side rotary body 26. The foot-operated pedal 15 can be dynamically displaced, and the foot-operated pedal 15 can be moved to the spring 17 without any action such as rotation resistance of the direct-acting lever 14 side connected to the lever-side rotating body 20.
It is possible to smoothly operate the pedal against only the elastic force of.

As a result, the driver can appropriately step on the foot pedal 15 with a small force, and therefore the driver frequently changes the rotational speed of the prime mover 11 at short intervals while driving a hydraulic excavator or the like. Even when trying to do so, it is possible to depress the foot pedal 15 delicately to change the rotation speed in a stable manner, so that the operability of the foot pedal 15 can be greatly improved and the rotation speed of the prime mover 11 can be improved. Control can be performed smoothly and stably.

Since the driver operates the direct-acting lever 14 and the foot-operated pedal 15 by the single potentiometer 37 using the rotating mechanism 19, the potentiometer 37 is used. Since it is not necessary to provide the direct-acting lever 14 and the foot-operated pedal 15 respectively, the number of parts can be reduced, and the operation amounts of the direct-acting lever 14 and the foot-operated pedal 15 can be detected with high accuracy. can do.

Further, since the rotational displacement of the pedal-side rotating body 26 detected by the potentiometer 37 is input to the controller 41, and the controller 41 rotates the governor lever 13 via the electric motor 40, the driver The controller 41 can finely control the number of revolutions of the prime mover 11 in accordance with the operation applied to the direct-acting lever 14 and the foot-operated pedal 15, thereby ensuring the operability of the direct-acting lever 14 and the foot-operated pedal 15. In addition to being improved, the rotation speed of the prime mover 11 can be controlled with high responsiveness according to the operating (work) situation.

Further, an idle changeover switch 42 and a saving operation changeover switch 43 are provided, and the respective switches 42, 43 are provided.
Since the engine speed of the prime mover 11 can be automatically reduced to an idle engine speed or can be limited to an economical engine speed, the driver can operate the switches 42 in addition to the direct-acting lever 14 and the foot pedal 15. , 43 to operate the prime mover 1 for various driving (working) situations such as hydraulic excavators.
The number of rotations of 1 can always be appropriately set and operated, and the operability thereof can be significantly improved, and the economical efficiency and durability of the prime mover 11 can be reliably improved.

In the above embodiment, the first operating means is composed of the direct-acting lever 14 and the second operating means is composed of the foot pedal 15, but the present invention is not limited to this, and the first operating means is not limited to this. The operating means is a foot pedal 15, the second operating means is a direct-acting lever 14, and the first rotating body and the second rotating body are a pedal side rotating body 26 and a lever side rotating body 20, respectively. It may be configured. In addition, the first operating means or the second operating means is the direct-acting lever 14 or the foot pedal 15
It may be configured with dials, pedals, switches, etc. for operations other than the above.

Further, in the above-mentioned embodiment, the case where the rotation speed control device of the prime mover is used for the hydraulic excavator has been described as an example, but the present invention is not limited to this, and for example, a construction machine such as a hydraulic crane or a wheel loader. The present invention may also be applied to other industrial and agricultural machines that use a diesel engine as a drive source.

[0058]

As described above in detail, according to the first aspect of the invention, the rotating mechanism connected to the first and second operating means is rotated according to the operation amount of the first operating means. The displacement is performed and the rotational displacement is performed in accordance with the operation amount of the second operating means, and the rotational displacement of the rotational mechanism is first coupled without mechanically connecting the rotational mechanism to the governor lever or the like of the prime mover. ，
Since the operation amount detection means detects the operation amount of the second operation means, the driver operates the first and second operation means as follows.
It can be operated smoothly with a comparatively small force without receiving the reaction force on the governor lever side, and by operating at least one of the first and second operating means, the rotating mechanism can be reliably operated according to this operation amount. It can be rotationally displaced. Therefore, the first operating means and the second
By properly using the operating means, the rotational speed of the prime mover can be appropriately controlled, the operability of the first and second operating means can be reliably improved, and the maneuverability of the hydraulic excavator or the like can be significantly improved. You can

According to the second aspect of the invention, the first and second rotating bodies are provided to the first and second operating means so as to be rotationally displaced in accordance with the respective operation amounts, and the displacement is performed. Since the transmission means transmits the rotational displacement from the first rotary body to the second rotary body, and the rotational displacement of the second rotary body is detected by the operation amount detection means, the operation amount of the first operation means is determined. Can be reliably transmitted to the second rotating body via the first rotating body,
The rotational displacement of the second rotating body can be reliably detected as the operation amount of the first and second operating means. Further, when the driver operates the second operating means, only the second rotating body can be rotationally displaced without transmitting the rotational displacement to the first rotating body (first operating means) side. The second operating means can be operated with a slight force without receiving a reaction force from the body side, and the operability of the second operating means can be greatly improved.

According to the invention described in claim 3,
Since the first and second operating means are composed of the direct-acting lever and the foot-operated pedal, and the operation amount detecting means is composed of the potentiometer, the direct-acting lever is manually tilted or the foot-operated pedal. By depressing, the rotating mechanism can be smoothly rotationally displaced according to the operation amount of the direct-acting lever and the foot-operated pedal without receiving a reaction force on the governor lever side. Can be detected with high accuracy using a potentiometer.

Further, according to the fourth aspect of the present invention,
Since the rotation speed control means is composed of the governor, the electric motor and the controller, the controller can drive and control the electric motor with high precision according to the operation amount of the first and second operation means detected by the operation amount detection means. The governor lever can be smoothly turned to a turning angle corresponding to the operation amount of the first and second operating means, and the rotational speed of the prime mover can be smoothly and stably controlled.

[Brief description of drawings]

FIG. 1 is an overall view showing a small hydraulic excavator using a rotation speed control device for a prime mover according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing a foot pedal and a rotation mechanism of a rotation speed control device for a prime mover according to an embodiment of the present invention together with a direct-acting lever in a state where a foot pedal and a rotation mechanism are attached to a floor plate of a driver's seat.

FIG. 3 is an exploded perspective view showing a direct-acting lever, a foot pedal, a rotating mechanism and the like in FIG.

FIG. 4 is an overall configuration diagram showing a rotation speed control device for a prime mover according to an embodiment of the present invention.

[Explanation of symbols]

 11 Prime mover 12 Governor 13 Governor lever 14 Direct-acting type lever (first operating means) 15 Foot pedal (second operating means) 19 Rotating mechanism 20 Lever side rotating body (first rotating body) 23 Pushing plate 26 Pedal side Rotating body (second rotating body) 29 Passive plate 36 Displacement transmitting section (displacement transmitting means) 37 Potentiometer (manipulation amount detecting means) 39 Rotation speed control section (rotation speed control means) 40 Electric motor 41 Controller

Claims (4)

[Claims] 1. A prime mover, a first operating means for variably setting and operating the rotational speed of the prime mover, and a first operating means provided at a position different from the first operating means for variably setting and operating the rotational speed of the prime mover. Two operating means, the first operating means and the second operating means are connected, and rotationally displaced according to the operation amount of the first operating means, and rotationally displaced according to the operation amount of the second operating means. The rotating mechanism that is displaced and the rotating position of the rotating mechanism are set to
A prime mover comprising an operation amount detecting means for detecting the operation amount of the second operating means, and a rotation speed control means for variably controlling the rotation speed of the prime mover according to the operation amount detected by the operation amount detecting means. Speed controller. 2. The rotating mechanism is connected to the first operating means side and is connected to the second operating means side, and a first rotating body that is rotationally displaced according to an operation amount of the first operating means. A second rotating body that is rotationally displaced according to the operation amount of the second operating means, and a displacement that is provided between the first and second rotating bodies and that transmits the rotational displacement of the first rotating body to the second rotating body. The rotational speed control device for a prime mover according to claim 1, further comprising a transmission means, wherein the operation amount detection means is configured to detect a rotational position of the second rotating body as the operation amount. 3. The first operating means is a direct-acting lever that is manually tilted, the second operating means is a foot-operated pedal that is depressed, and the operation amount detecting means is a potentiometer. The rotational speed control device for a prime mover according to claim 1 or 2, which is configured. 4. The rotation speed control means includes a governor attached to the prime mover for changing the rotation speed of the prime mover according to a rotation angle of the governor lever, an electric motor for rotating the governor lever of the governor, and the operation. 4. The rotation speed control device for a prime mover according to claim 1, comprising a controller for driving and controlling the electric motor according to the operation amount detected by the amount detecting means.