JPH06117282A - Engine control device for construction machine - Google Patents

Abstract

PURPOSE:To reduce engine noise by arranging a stopper in a position where tilting and rotating movement of a link lever can be stopped in the middle when a governor lever is adjusted in a low idle position. CONSTITUTION:A stopper 24 is arranged in a position where tilting and rotating movement of a link lever 5 can be stopped in the middle when a governor lever 2 is adjusted in a low idle position B from a high speed rotation position D by operation of a control motor 7. When a hand accelerator lever 3 is operated in a high speed rotation position (H position), a switch is operated, and the control motor 7 is operated, and tilting rotation of the link lever 5 is stopped by a stopper 24, and the governor lever 2 is set in a necessary medium speed rotation position E. In this way, an engine is rotated accurately in the necessary medium speed revolution number, and engine noise is reduced considerably, and large engine horse power can be exhibited.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control device for controlling the rotation speed of an engine mounted on a construction machine such as a small excavator or a work vehicle.

[0002]

2. Description of the Related Art FIG. 5 is a diagram showing a conventional engine control device mounted on a construction machine (not shown). In the figure, 1 is an engine, 2 is a governor lever of the engine 1, 3 is a hand accelerator lever arranged near the driver's seat, 4 is a fixed bracket, 5 is a link lever, 6 is a worm gear reducer, 7 is a control motor, 8 And 9 are push-pull cables, respectively. FIG. 6 is an AA of FIG.
FIG. In the figure, 10 is a link lever 5
Is a fulcrum pin which is the center of tilt rotation, 11 is an outer cylinder stopper in the middle of the push-pull cable 8, and 12 is a terminal locking block of the push-pull cable 9. FIG. 7 shows B of FIG.
It is the top view seen from -B. FIG. 8 is a detailed view of section C of FIG. In the figure, 13 is a stroke operating portion of the worm gear reducer 6, and 14 is an electric wiring harness of the control motor 7. FIG. 9 is an electric circuit diagram for the control motor 7. In the figure, 15 is a circuit for an auto switch mechanism provided inside the control motor 7, 16 is a drive motor unit, 17 is a conductive plate, 18 is a key switch, 19 is a relay, 20 is a switch for engine control, 21 Is the power supply. In the electric circuit of FIG. 9, when the key switch 18 of the construction machine is turned on and the switch 20 is turned on while the engine 1 is rotating, the relay 19 is switched and actuated. 23 is conducted. When the control motor 7 rotates 180 ° from 0 °, the contact 22 is connected to the ground side. At this time point, the armature of the drive motor unit 16 is short-circuited, the electric brake is applied, and the control motor 7 is immediately placed in this position. Stop. When the switch 20 is turned off, the control motor 7 turns 180
Rotate 360 ° from ° to stop. By rotating the control motor 7 by 180 ° as described above, the rotational movement is converted into stroke movement (reciprocating movement) by the worm gear reducer 6. As a result, the worm gear reducer 6
The tip end portion of the push-pull cable 9 connected to the stroke operating portion 13 can be moved by the stroke S as shown in FIG.

The conventional engine control device for a small excavator is provided with a hand accelerator lever 3 capable of arbitrarily changing and maintaining the engine speed as shown in FIGS. 5 to 9, and the hand accelerator lever 3 and the governor lever 2 are provided. The outer cylinder stopper 11 in the middle of the connected push-pull cable 8 is locked to the link plate 5, and the link plate 5 is attached so as to rotate in the push-pull direction of the push-pull cable 8 and near the engine 1. Is provided with a worm gear reducer 6 for converting a rotational motion into a required stroke motion, and the worm gear reducer 6 is driven by a control motor 7 having an auto switch mechanism circuit 15. Connect the stroke operating portion 13 and one end of the link lever 5 via the push-pull cable 9. When the high-speed rotation position (H position shown in FIG. 5) of the hand accelerator lever 3 is operated, the switch (switch 20 shown in FIG. 9) is operated to operate the control motor 7, thereby moving the link lever 5 to the a position shown in FIG. The governor lever 2 is returned to the low idle position (position B shown in FIG. 5) by inclining and rotating to.

[0004]

FIG. 9 shows a small shovel equipped with a conventional engine control device, for example, when waiting for a dump while operating a hand accelerator lever to a high-speed rotation position to perform work. Switch 2
By turning on 0, the hand accelerator lever 3
Without returning to the low idle position L (shown in FIG. 5)
The engine 1 can be rotated in a deceleration manner. Then, when the work is started again, if the switch 20 is turned off, the link lever 5 returns to the C position shown in FIG.
The engine 1 rotates at high speed. Here, FIG. 10 is a rotational speed-horsepower diagram of the engine 1. N as shown in FIG.
Although 2 is the low idle speed, the maximum horsepower (rated horsepower) of the engine 1 is not obtained at the maximum speed N3 but is exerted at the medium speed N2. Therefore, when the engine 1 is rotating at a high speed, engine noise is large, but engine horsepower is not sufficiently exerted. For this reason, when the small shovel performs excavation work, the driver adjusts the hand accelerator lever to a desired middle-speed rotation position. Not only is the adjustment operation troublesome, but the operation of setting the hand accelerator lever to the required middle-speed rotation position is inaccurate. It is an object of the present invention to provide an engine control device that can solve the above problems.

[0005]

According to the engine control device of the present invention, a push-pull cable having a hand accelerator lever capable of arbitrarily changing and maintaining the engine speed and connecting the hand accelerator lever and the governor lever is provided. Worm gear reducer that locks the outer cylinder stopper of the device to the link plate and attaches the link plate so as to rotate in the push-pull cable push-pull direction, and converts the rotational motion into the required stroke motion near the engine. The worm gear reducer is driven by a control motor having an auto switch mechanism circuit, and the stroke operating part of the worm gear reducer and one end of a link lever are connected via a push-pull cable, Switch operation when operating the high-speed rotation position of the accelerator lever When the governor lever is adjusted from the high-speed rotation position to the low idle position by the operation of the control motor in an engine control device in which the governor lever is returned to the low idle position by tilting the link lever by operating the control motor. A stopper is provided at a position where the tilting movement of the link lever can be stopped midway, and the tilting movement of the link lever is performed by operating the control motor by operating the switch when operating the high-speed rotation position of the hank door axel lever. The movement is stopped by the stopper, and the governor lever is set to the required middle speed rotation position. Alternatively, instead of providing the worm gear reducer, the control motor, and the stopper, arrange a multi-position solenoid that strokes to a desired position by operating the switch, and perform the switch operation when operating the high-speed rotation position of the hand accelerator lever. Thus, the link lever is tilted and rotated to set the governor lever to the required middle speed rotation position, low idle position or high speed rotation position. Alternatively, instead of providing the stopper, another set of governor lever worm gear reducer driven by a control motor is arranged near the engine, and the governor lever worm gear reducer control motor is connected to the link lever. The worm gear reducer is designed to rotate in conjunction with the rotation of the control motor, and the stroke operating part of the worm gear reducer for governor lever and one end of the governor lever are connected via a push-pull cable to increase the speed of the hand accelerator lever. When operating the rotary position, operate the switch to rotate the control motor of the worm gear reducer connected to the link lever to tilt and rotate the link lever toward the low idle position, and at the same time control the worm gear reducer for the governor lever. Rotate the motor in conjunction with the governor lever And to set the rotational position.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing an engine control device according to claim 1 of the present invention. In the figure, the same reference numerals are given to those using the same constituent elements as those in the prior art. 24 is a stopper, 25 is a bolt for adjusting the contact position of the stopper 24, 4 '
Is a fixed bracket, reference numeral D is a high speed rotation position of the governor lever 2, reference numeral E is a middle speed rotation position of the governor lever 2, and reference numeral F is a middle speed rotation position of the link lever 5 when the governor lever 2 is set to a middle speed rotation position E. is there. Next, the configuration of the engine control apparatus according to claim 1 of the present invention will be described with reference to FIG.
When the governor lever 2 is adjusted from the high-speed rotation position D to the low idle position B by the operation of the control motor 7, the stopper 24 is provided at a position where the tilting movement of the link lever 5 can be stopped midway. Three
When the control motor 7 is operated by operating a switch (referred to as the switch 20 in FIG. 9) at the time of operating the high speed rotation position (H position) of the link lever 5, the tilt rotation of the link lever 5 is stopped by the stopper 24, and the governor lever 2 is moved. It is configured to set the required middle speed rotation position e.

Next, the operation of the engine control apparatus according to claim 1 of the present invention will be described. When working with a small excavator, the contact position adjusting bolt 25 of the stopper 24 is adjusted and set in advance so that the governor lever 2 comes to the E position when the tilting and rotating position of the link lever 5 becomes the F position. deep. Therefore, when the driver performs the work with the engine 1 rotating at the required middle speed, when the switch (switch 20 shown in FIG. 9) is operated while the hand accelerator lever 3 remains in the high speed rotation position H, the control motor 7 and Due to the operation of the worm gear reducer 6, the link plate 5 starts to tilt and rotate from the high speed rotation position C toward the low idle position B. However, since the stopper 24 is provided, the link lever 5 stops at the medium speed rotation position, and the governor lever 2 is maintained at the medium speed rotation position E. It is possible to accurately rotate the engine 1 at a required middle-speed rotation speed and to considerably reduce engine noise to exert a large engine horsepower.
Although the stopper 25 is provided, when the hand accelerator lever 3 is manually operated from the high speed rotation position H to the low idle position L, or the hand accelerator lever 3 is operated in the low idle position direction other than the high speed rotation position H. When the switch is operated with, the governor lever 2 can be returned to the low idle position (b) and the deceleration of the engine 1 can be performed.

Next, FIG. 2 is a diagram showing an engine control device according to claim 2 of the present invention. In the figure, components using the same components as those of the engine control device in FIG. 1 are designated by the same reference numerals. Reference numeral 26 is a 3-position solenoid, 27 is a slide rod of the 3-position solenoid 26, 28 is a selector switch, and 4 is a fixed bracket. Figure 3
FIG. 4 is a vertical cross-sectional view of the 3-position solenoid 26 in the front-rear direction. The 3-position solenoid 26 is moved by a stroke in the front-rear direction by operating the selector switch 28 to the N position, the L0 position, and the H0 position (the stroke is S ', S'as shown in FIG. 3), and the slide rod. The tip end portion of 27 can be selectively set to any one of the g-position, the chi-position, and the re-position.

Next, the structure of the engine control apparatus according to the second aspect of the present invention will be described with reference to FIGS. In the engine control device of claim 2, the worm gear reducer 6 and the control motor 7 used in the engine control device of claim 1 in FIG. 1 and the stopper 24 are not provided, and the stroke is moved to a desired position by the selector switch 28. It works 3
By arranging the position solenoid 26 and performing a switch operation (selection operation of the selector switch 28) at the time of operating the high speed rotation position (H) of the hand accelerator lever 3, the link lever 5 is tilted and rotated so that the governor lever 2 is required. The high-speed rotation position E, the low idle position B, or the high-speed rotation position D is set.

Next, the operation of the engine control apparatus according to the second aspect of the present invention will be described. According to another aspect of the engine controller of the present invention, the selector switch 28 is set to the N position, the L0 position, and the H position.
When the 0 position is selected and operated, the 3-position solenoid is switched to the 3-position, so that the link lever 5 tilts to the required middle speed rotation position, low idle position a, and high speed rotation position c in advance. It is adjusted and set. Therefore, by setting the accelerator lever 3 to the high speed rotation position H and selectively operating the selector switch 28 to the N position, the L0 position or the H0 position, the governor lever 2 is moved to the medium speed rotation position E, the low idle position B or the high speed rotation position. It can be set to two. That is, the required engine rotation can be obtained by the driver's switch selection operation.

Next, FIG. 4 is a diagram showing an engine control apparatus according to a third aspect of the present invention. In the figure, the same reference numerals are given to those using the same constituent elements as those in the prior art. Reference numeral 29 is a governor lever worm gear reducer, 30 is a control motor for the governor lever worm gear reducer 29, 2'is a governor lever, and 9'is a push-pull cable. next,
The structure of the engine control apparatus according to claim 3 of the present invention will be described with reference to FIG. According to another aspect of the engine control apparatus of the present invention, another set of governor lever worm gear reducer 29 driven by the control motor 30 is arranged near the engine 1, and the governor lever worm gear reducer 29 is controlled by the control motor 30.
Of the worm gear reducer 29 connected to the link lever 5 is rotated in conjunction with the rotation of the control motor 30 of the worm gear reducer 29, and the stroke operating portion of the worm gear reducer 29 for the governor lever and one end of the governor lever 2 '. Is connected via a push-pull cable 9 ', and a switch operation is performed when the high-speed rotation position (H) of the hand accelerator lever 3 is operated to rotate the control motor 7 of the worm gear reducer 6 connected to the link lever 5. At the same time, the link lever 5 is tilted and rotated toward the low idle position, and at the same time, the control motor 30 of the worm gear reducer 29 for the governor lever is interlocked and rotated so that the governor lever 2'is set to the medium speed rotation position e.

Next, the operation of the engine control apparatus according to claim 3 of the present invention will be described. When the driver operates the engine 1 at the required middle speed and operates the switch (the switch 20 shown in FIG. 9) while the hand accelerator lever 3 remains in the high speed rotation position H, the control motor 7 and the worm gear are operated. Due to the operation of the speed reducer 6, the link plate 5 is
Tilt from the high-speed rotation position c toward the low idle position a. At the same time, the control motor 30 is interlocked to operate the governor worm gear reducer 29, so that the governor lever 2'is moved via the push-pull cable 9'and maintained at the required middle-speed rotation position e. Therefore, the engine noise of the engine 1 can be suppressed to a considerably low level, and a large engine horsepower can be exerted.

[0013]

In a small shovel equipped with the engine control device of the prior art, the engine rotation can be reduced to the deceleration rotation by the switch operation, but the switch operation requires the medium speed rotation (the engine noise at this middle speed rotation is reduced). Was quite low and the engine horsepower was high). Therefore, the driver had to adjust the hand accelerator lever to the required middle speed rotation position. Not only is the adjustment operation troublesome, but the operation of setting the hand accelerator lever to the required middle-speed rotation position is inaccurate. However, in the engine control device of the present invention, when the driver wants to work with the engine rotating at the required middle speed, if the switch is operated with the hand accelerator lever kept in the high speed rotation position, the control motor and the worm gear reducer are operated. The link plate starts to tilt and rotate from the high speed rotation position toward the low idle position. However, since the stopper is provided, the link lever stops at the medium speed rotation position, and the governor lever is maintained at the medium speed rotation position. The engine can be accurately rotated at the required middle speed, and the engine noise can be considerably reduced to exert a large engine horsepower. Further, in the engine control device in which a plurality of position solenoids are arranged, the engine rotation can be selected from the required middle speed rotation, low idle rotation or high speed rotation by performing the selection operation of the selector switch, which is very convenient. Further, in the engine control device in which two sets of worm gear reducers are arranged, the governor lever is set to the medium speed rotation position by interlockingly rotating the two sets of control motors. Therefore, as in the case where the stopper is provided, The engine noise of the engine can be kept quite low and large engine horsepower can be exerted.

[Brief description of drawings]

FIG. 1 is a diagram showing an engine control device according to claim 1 of the present invention.

FIG. 2 is a diagram showing an engine control device according to claim 2 of the present invention.

FIG. 3 is a vertical sectional view of a three-position solenoid according to claim 2 of the present invention.

FIG. 4 is a diagram showing an engine control device according to claim 3 of the present invention.

FIG. 5 is a diagram showing a conventional engine control device.

6 is a view seen from AA in FIG. 5. FIG.

FIG. 7 is a plan view seen from the line BB of FIG.

FIG. 8 is a detailed view of a C portion of FIG.

FIG. 9 is a control motor electric circuit diagram.

FIG. 10 is a horsepower diagram of the engine speed.

[Explanation of symbols]

 1 Engine 2, 2'Governor Lever 3 Hand Accelerator Lever 5 Link Lever 6,29 Worm Gear Reducer 7,30 Control Motor 8,9,9 'Push Pull Cable 11 Outer Cylinder Stopper 13 Stroke Actuator 20 Switch 24 Stopper 26 Multiple Positions Solenoid 28 selector switch

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location F02D 31/00 301 A 9038-3G

Claims (3)

[Claims] Claim: What is claimed is: 1. A hand accelerator lever capable of arbitrarily changing and maintaining the engine speed is provided, and an outer cylinder stopper of a push-pull cable connecting the hand accelerator lever and the governor lever is locked to a link plate. , The link plate is attached so as to rotate in the push-pull cable push-pull direction, and a worm gear reducer that converts the rotational movement into the required stroke movement is arranged near the engine, and the worm gear reducer is automatically switched. It is driven by a control motor equipped with a mechanism circuit, and the stroke operating part of the worm gear reducer and one end of the link lever are connected via a push-pull cable to enable switch operation when operating the high-speed rotation position of the hand accelerator lever. The link lever by activating the control motor. In an engine control device in which the governor lever is tilted and returned to return the governor lever to the low idle position, when the governor lever is adjusted from the high speed rotation position to the low idle position by the operation of the control motor, the tilt lever movement of the link lever is prevented. A stopper is provided at a position where it can be stopped on the way, and when the hand accelerator lever is operated at high speed, a switch operation is performed to operate the control motor so that the tilt rotation of the link lever is stopped and the governor lever is required. An engine control device for a construction machine, which is configured to be set to a middle-speed rotation position. 2. A hand accelerator lever capable of arbitrarily changing and maintaining the engine speed is provided, and an outer cylinder stopper of a push-pull cable connecting the hand accelerator lever and the governor lever is locked to a link plate. , The link plate is mounted so as to rotate in the push-pull cable push-pull direction, and a reciprocating mechanism that performs stroke operation by switch operation is arranged near the engine. The stroke operating part of the reciprocating mechanism and the link lever An engine control device in which one end is connected via a push-pull cable and a switch operation is performed when a high-speed rotation position of a hand accelerator lever is operated to tilt and rotate a link lever to adjust a governor lever, Stroke operation to required position by switch operation A multi-position solenoid is installed, and the switch is operated when operating the high-speed rotation position of the hand accelerator lever to tilt the link lever and set the governor lever to the required middle-speed rotation position, low idle position or high-speed rotation position. An engine control device for a construction machine, which is configured to: 3. A hand accelerator lever capable of arbitrarily changing and maintaining the engine speed is provided, and an outer cylinder stopper in the middle of a push-pull cable connecting the hand accelerator lever and the governor lever is locked to a link plate. , The link plate is attached so as to rotate in the push-pull cable push-pull direction, and a worm gear reducer that converts rotational movement into the required stroke movement is arranged near the engine, and the worm gear reducer has an automatic switch mechanism. The worm gear reducer is connected to the stroke operating part and one end of the link lever via a push-pull cable, and the switch is operated when the high-speed rotation position of the hand accelerator lever is operated. The link motor by operating the control motor. In an engine control device that tilts and turns the governor to return the governor lever to the low idle position, another set of governor lever worm gear reducers driven by a control motor is placed near the engine, and the governor lever worm gear reducer The control motor is made to rotate in conjunction with the rotation of the control motor of the worm gear reducer connected to the link lever, and the stroke operating part of the worm gear reducer for governor lever and one end of the governor lever are pushed and pulled. Connect via a cable, and operate the switch when operating the high-speed rotation position of the hand accelerator lever to rotate the control motor of the worm gear reducer connected to the link lever and tilt the link lever toward the low idle position. Worm gear deceleration for governor lever at the same time Construction machine engine control device being characterized in that so as to set the medium speed rotational position governor lever and allowed interlocking rotation control motor.