DK154312B - INSTRUMENT FOR AUTOMATIC ADJUSTMENT OF THE ENGINE CIRCUIT OF A EQUIPMENT - Google Patents

Abstract

1. A device for automatically controlling the engine speed of an earthmoving machine having an internal combustion engine, more particularly a hydraulic excavator having a diesel engine, between a working speed and a second speed below said working speed, comprising a hydraulic circuit (6) fed by at least one hydraulic pump (3, 4) to actuate a working tool, a pick-up (9) which is disposed in the hydraulic circuit (6) and which is (pressure-)controlled by the pressure in the hydraulic circuit (6), and a control element (21), by means of which there is actuated, on the one hand, a control lever (26) disposed in the area of the driver's seat and adjustable manually there and, on the other hand, a speed adjusting lever (33) acting on the internal combustion engine fuel regulator, the control element (21) being adapted to be so actuated, via a control line (38), by means of a switch (17, 18) connected to the pick-up (9) via a delay means (12), the actuation being provided by controlled application of a separate energy source (19), that the connection between the energy source (19) and the control element (21) is blocked when a predetermined critical pressure is exceeded in the hydraulic circuit (6) so that the control element (21) returns the speed adjusting lever (33) to the working speed set at the control lever (26), and the connection between the energy source (19) and the control element (21) can be released with a controlled delay by the delay means (12) when the predetermined critical pressure in the hydraulic circuit (6) is not attained, so that the control element (31) adjusts the speed adjusting lever (33) without adjusting the control lever (26) to the idling position.

Description

DK 154312 B

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a device for automatically regulating the engine turnover number of an internal combustion engine tillage machine, in particular a hydraulic excavator, between a working turnover number adapted to a particular task and a second turnover number located on one side by means of a control link in connection with a manually operated control rod in the vicinity of the front seat and on the other hand is connected to a by-pass control rod acting on the fuel regulator of the engine.

10

The engine of a tillage machine, such as a hydraulic excavator, is generally a diesel engine with a fuel regulator for adjusting the amount of fuel consumed by a rotary thrust bar. a unit of time is supplied to the combustion chambers of the diesel engine 15 to operate the engine at a certain number of turns, which in turn is a measure of the power delivered by the engine.

As the operator is usually also the driver who sits in a cab at the respective tillage machine and from there controls the course as well as special working movements, a guide rod (throttle pedal) is usually arranged near the driver's seat by means of which the driver via a The connecting link acting on the control rod (if necessary via a chain) can set the bypass number and thereby effect power control from the driver's seat.

By this "link" it may be a so-called "link bar" and / or a Bowden feature or the like. Only by operating the control rod 30 located in the vicinity of the driver's seat will it be possible to act on the turnstile control rod of the fuel regulator, so that the engine's turnover number and thus power can be adjusted by means of this control rod.

At the commencement of a work task, the operator sets the engine by 35 using the control rod to the speed required by the particular work task (eg reading pipe sections from a truck) and thus the power of the motor, after which the work task is started.

DK 154312B

2

During the execution of the work, longer breaks often occur, for example, when sand is to be unloaded from a truck with a trailer, and the trailer must be unloaded after loading the truck itself. There are other uses in which certain tasks are accomplished with more or less forced breaks.

During these breaks, the operator lets the preselected and optimally set turnover rate be set, while the engine during the work breaks continues with the aforementioned turnover number, so that the operator does not have to make a new adjustment when resuming a work assignment. This leads to unacceptably high energy consumption. As is well known, the fuel consumption of an engine depends on the number of revolutions, in addition, for example, the diesel engine of a hydraulic excavator also drives the hydraulic pumps, etc., so that even in the aforementioned breaks there is a disproportionately high fuel consumption.

German Patent Specification No. 2,502,221 discloses a device in which the operator sets, by means of the control rod, a basic idle speed number to an idle speed numeral, which is referred to as the "idle speed" number. During the execution of the excavation work, the control rod is operated since, in the execution of a working movement, pressure means are fed to the supply line, the pump being connected to certain pipe sections. Thereby, a stem member of a piston 1-cylinder inner unit is displaced against a spring, and the piston 1-cylinder unit becomes longer, so that the rod acting on the injection pump is rotated and the engine speed is increased.

30 If the pressure in the pump line is lifted, a corresponding pressure drop occurs in the supply line, whereby the plunger of the plunger 1-cylinder unit returns to the rest position under the action of the aforementioned spring (and the pressure means via a line and a throttle in 1 flow back into the pressure medium. 35 holder). Consequently, the rod acting on the injection pump is brought into the "running" position very quickly by means of the cylinder of the piston cylinder unit, while it is substantially longer to return to the actuating step.

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DK 154312 B

With this known device, it is a disturbance-pressure-dependent speed control between the idle speed (respectively an idle speed) and the maximum speed, where the engine, under the influence of a constant pressure, runs at a maximum speed.

This is not entirely satisfactory since a failure of control energy necessarily causes the motor to remain at the aforementioned basic idle speed, whereby the tillage machine will no longer be able to operate.

The object of the invention is to provide a device of the kind mentioned in the beginning, where the energy consumption and the noise load in the working breaks are low. In addition, the device must be so arranged that the tillage machine, even in the event of failure of the control energy which triggers the intended automatic control, is still able to operate, with the aim of low pressure consumption of the hydraulics, so that such as there. In the working example "lowering of load" work is done with fuel saving low turnover 0 and not with forced high turnover figures, since the turnover number is forcibly set 11 in the known device and the control rod must be equipped with resumption of the work task.

In the automation according to the invention, no actual orbital control shall be made, as this is 10 to 25 precipitated by the known device. On the other hand, the workflow figure adapted to the respective task is set as before via a rope pull.

This object is achieved according to the invention in that, upon interruption of the work task over a given peak interval, a first signal is produced to a control link guiding control device which causes the control link to actuate the bypass actuator rod acting on the fuel regulator without adjustment of the control rod. a position corresponding to the idle position of the motor, and that upon resuming the task another signal is generated for the control means which causes the control link again to bring the by-pass control rod in a position corresponding to the task and at the beginning of the task at 4

DK 154312 B

by means of the control rod set setting, in which a delay device is arranged, by means of which the automatic switching of the motor from a working orbit to the idle orbit occurs after a given time interval Δ t.

5

Preferred embodiments of the invention are set forth in the dependent claims.

The invention will be explained in more detail below with reference to the drawing, in which 1 shows a device according to the invention for automatically controlling the engine turnover number of a tillage machine, in working position 11; FIG. 2. a diagram of the input and output pulses for a time relay included in the control device; FIG. 3 is a diagram of an emergency shutdown; FIG. 4 is the one shown in FIG. 1 in the pause position shown in FIG. 1; and FIG. 5 is the one shown in FIG. 1 is a perspective view of the control device shown in FIG.

FIG. 1 shows a diagram of a device for automatically adjusting the motor orbital number of a hydraulic tillage machine, such as an excavator for the respective work tasks between a orbital number and another orbital number lower than the working orbital number, if any. -idling number of revolutions.

When performing a particular task, the operator sets the machine to an appropriate orbital number by means of a control rod (gas rod) so that the excavator works with a certain power. When a predetermined pasu is occurring during a working break, the engine turnover number is automatically reset t for 1 t bypassing the rig for 1 island easily. When resumption of work task 3 5 is automatically reset to the bypass setting set by the operator.

In FIG. 1 denotes 1 a diesel engine in a hydraulic tillage machine coupled to a mechanical coupling 2

DK 154312 B

s hydraulic pumps 3 and 4. The pumps provide a wiring system 6 which leads to consumers, as indicated by arrow 7.

In the conduit system 6, there is a change valve 8 which decreases the higher pressure of the pumps 3 and 4. The change valve 8 is in contact with a pressure-sensitive contact 11 which can be adjusted to e.g. 40 bar. Upon reaching a pressure of 40 bar, the switch 11 is closed, thereby supplying current to a relay 12 with an input 13 and an output 14.

From the output 14 of the time relay 12, leads 16 are passed to a relay 17 for controlling an air valve 18, which air valve 11 is located in a dotted shown air line 19 which leads from the air valve 38 to a piston-cylinder unit 21, more specifically to the end 22 of the cylinder 23 of the piston-cylinder unit 21. At this end 22 of the piston-cylinder unit 21, a Bowden feature 24, which at its other end, is attached to a guide rod 26 which is pivotable at its foot point.

A compression spring 29 acts on the inside of the piston 28 of the 20 piston-cylinder unit 21. The compression spring 29 supports with its other end against the inside of the cylinder 23 and presses the piston 28 to the left in FIG. First

The piston rod 31 of the piston 28 is pivotally at its free end (at 32) connected to a mid-articially supported rod 33 which at its free end is actuated by a spring 34. The rod 33 acts on the fuel regulator supplied to the diesel engine. 1 and serves to set the bypass number.

A stop 36 that aligns with the piston rod 31 can be adjusted 30 by means of a screw 37 or the like.

As mentioned before, before performing a particular task, the operator adjusts it by means of the control rod 26 to the driver's seat for a suitable turnover number which is higher than the idle turnover number. The control rod 26 does not act directly on the fuel regulator, but rather via the Bowden pull 24, the piston cylinder in the lower unit 21 and the bypass number 11 in the rod 33, so that the previously generally rigid coupling between the control rod 26 and the adjustment rod 33 does not occur.

DK 154312 B

6 In the embodiment of FIG. In one embodiment, piston 28 of the piston cylinder unit 21 is positioned to the left immediately in front of the dead center position in the cylinder 23, corresponding to the operator having set the bypass number to the highest value. Alternatively, there may be set to an orbital number between the highest engine speed and idle speed, as is often the case, and for which the device according to the invention is suitable.

In this state, the engine turnover number is e.g. 2300 Ο / min, while the engine idle speed at which the fuel consumption goes back to 1/6 to 1/8 is usually between 700 and 1000 rpm.

When the pressure during a working break falls in the wiring system 6, 15 the switch 11 opens in the pressure sensor 9, whereby the input signal at the input 13 of the time relay 12 goes to "0", while the signal s, which still assumes the value "1", does not yet appear at the output 14 of the time relay 12. Only after a certain delay Δ t of e.g. 5 sec. corresponding to the working break being longer than 20 for example. to receive a new tube or the like, the output signal also goes to "0", as shown by the display of the corresponding relay S} 3 of the input 13 and sj4, respectively; 2 shows the temporal dependence and assignment of the signals sj-3 and s ^ 4 and their time dependence.

25

By exceeding the time delay interval Δ t, the time relay 12 opens, thereby creating passage through the air valve 18 to the disconnected air line 19 ·, so that compressed air flows into the cylinder 23 via the air line 38 and the plunger 28 is fed back against the action of the pressure spring 29 from FIG. 1 to the position shown in FIG. 6, which is limited by the free end (at 32} of the piston rod 31 striking the adjustable stop 36 so that the pistons 28, 31 cannot be moved further.

In this movement of the pistons 28, 31 from the one shown in FIG. 1 to the position shown in FIG. 4, the adjusting rod 33 is rotated about the joint 39 (which serves as a bearing) and the motor 35 7 ·

DK 154312 B

the number of revolutions is thereby automatically reset to the idle number of the circulation number set by means of the control rod 26, so that the energy consumption of the motor during the work breaks is reduced.

5,700 rpm. as is well known, it is considerably smaller than at an orbit number 'from 1500 or even 2300 Ο / min., and also the water loss of the pump, which operates at high or lower flow rates at full feed volume and at a reduced flow rate, is very small.

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It will be seen that in a work pause longer than Δ t, the bypass number is automatically switched back to the idle bypass number even if the operator has not changed the setting of the control rod 26. This is only in the position which is initially selected by the operator for it. respective work assignment.

If, after a (appropriately long) pause, the operator resumes work, a pressure is regenerated in the wiring system 6, which is recorded by the pressure sensor 9. When this pressure exceeds the aforementioned preset value of e.g. 40 bar, the switch 9 is closed again, whereupon the input signal s 13 and thereby also the output signal S14 of the time relay 12 assumes the value "1", so that the relay 12 closes corresponding to the magnetic switch 17 causing the compressed air line 19 through the air valve 18 to be switched off again. At the same time - which is not shown in the drawing - it is automatically ensured that the pressure between the piston 28 and the above-mentioned cylinder wall is released through the opening in the cylinder 23, so that the piston 28, as well as the piston 1 rod, is returned from the one shown in FIG. 4 to the position shown in FIG. 1 by the compression spring 29. This provides a representation of the adjustment rod 33 from the position shown in FIG. 4 to the position shown in FIG. 1, and thus an increase in the engine turnover to the value set at the beginning of the work by the operator by means of the control rod 26.

A particular advantage of the device according to the invention is that the system, for which the number of turns is reduced by the occurrence of longer working breaks, at the failure of the control energy allows

DK 154312 B

the machine continues to operate - although it is not possible to save the fuel according to the invention - which is not the case with the previous devices of a similar nature, since interrupting the supply of control energy causes it to be reset initially to the set working cycle figures, while the failure of control energy at the known device described above causes the motor to remain at idle or stall and adjust to it and consequently is no longer able to operate.

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This turnaround reduction does not occur immediately, but with a predetermined time delay to avoid a reduction in the turnaround time during short work breaks, which could otherwise give rise to uneasy operation and not least impose unreasonably high demands on the engine and steering part.

Another advantage of the device according to the invention is that in the event that the load does not require energy and is even available such as this e.g. is the case with the working game "Last Absenken", becomes low (corresponding to the idle idle number), since the working hydraulics signal low pressure consumption, while in the known devices through the necessary equipment of the control rod an acceleration of the motor occurs, so that this also f. eg. during the work game "Load absenken" or similar work tasks with a high 25 turnover figures and corresponding fuel consumption.

FIG. 3 shows another emergency disconnect circuit for the device according to the invention, where the stop 36 is located in an electrical circuit. Such a design is suitable for diesel engines whose (intentional) shutdown is not effected through a particular Bowden feature or the like, but otherwise through a relatively large idle setting, so that the device according to the invention, where applicable, is fitted to such engines. in the interrupted or intermittent state, respectively, can lead to a complete shutdown of the engine, which is not observed and especially to diesel engines, which is also known to be cumbersome - apart from the effects at start - since the start of diesel engines is only slightly more difficult. one at Otto-

Claims (7)

9 'DK 154312 B engines. In such a case, the stop 36 ensures that a reduction in breaks does not cause a shutdown of the motor, which, on the other hand, runs at idle speed. a patent claim. 5 Device for automatically controlling the engine turnover number of a tillage machine, in particular a hydraulic excavator, between a working turnover number adapted to a particular task and a second turnover number lying below this working turnover number, by means of a control link (21) which side is connected to a manually operated control rod (26) near the driver's seat and on the other side is connected to a by-pass control rod acting on the fuel regulator of the engine (1), characterized in that a interrupting the task over a given time interval, a first signal is produced to a control member (21) controlling control means (18) which, without adjusting the control rod (26>, causes the control link (21) to bring the actuating rod control rod acting on the fuel regulator (21) 33.) in a position corresponding to the idle position of the engine (1) and that a resumption of the work task produces another signal for the control organ a net (18) which causes the control link (21) again to bring the bypass control lever (33) in a position corresponding to the task 25 and set at the beginning of the task by the control rod (26), in which a delay device (12) is arranged. ), by means of which the automatic switching of the motor from a working orbit to the idle orbit occurs after a given time interval (Δ t). Device according to claim 1, characterized in that the time interval (Δ t) is adjustable. Device according to claim 1 or 2, characterized in that the delay device is a time relay (12), whose output signal follows the input signal after a certain time delay (Δ t). DK 154312 B Device according to claims 1-3, characterized in that the control means (18) for controlling the control link (21) is controlled by a pressure gauge (9) arranged in the hydraulic circuit (6), the first signal being produced by a failure, and the ® second signal is produced by exceeding a predetermined limit pressure in the hydraulic circuit. Device according to claim 4, characterized in that a piston-cylinder unit (21) is arranged as a guide link, the spring-actuated piston (28) at one end of which is connected to the control rod (26) and whose piston rod (31) stands in conjunction with the turntable control bar (33) acting on the fuel regulator. Device according to claim 4 or 5, characterized in that the piston-cylinder unit (21) is connected to the guide rod (26) over a Bowden pull. Device according to one or more of the preceding claims, characterized in that the control means (17, 18) controlled by the pressure gauge (9) in the hydraulic circuit (6) / is constituted by a magnetically controlled air valve, by means of which a The compressed air line (19) leading to the piston-cylinder unit (21) can be opened / closed depending on the pressure in the hydraulic circuit. 25 30 35