JP2006062782A - Engine control system for crane truck - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine control device capable of realizing suitable idling stop while considering characteristics of crane work by a crane truck. <P>SOLUTION: In the engine control device for the crane truck, a hydraulic pump 21 is operated making an engine 8 as a power source, a hydraulic actuator 23 is driven by a delivered oil of the hydraulic pump 21 based on operation of a crane operation means 30 and hanging up work of a hanging baggage is performed by a wire 9 hung down from a distal end 10 of a boom. The device is provided with a crane operation detection means for detecting existence of the operation of the crane operation means 30; a hanging baggage detection means for detecting existence of the hanging baggage hung down from the distal end 10 of the boom; and an engine stopping means for stopping the engine when no crane operation state and no hanging baggage state based on a signal from the detection means are simultaneously continued for a predetermined set time. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an engine control device for a crane vehicle that automatically stops an engine for fuel saving, exhaust, noise reduction, and the like.

As a conventional technique, in a construction machine that operates a hydraulic pump using an engine as a power source and drives a hydraulic actuator by discharge oil of the hydraulic pump based on an operation of the operating means, There has been proposed a construction machine in which the engine is automatically stopped by a control means when a set grace period elapses and the operator gets off (see, for example, Patent Document 1).
JP 2003-307142 A (page 5-7, FIG. 1-2)

  However, in a crane operation using a crane vehicle, the operation waiting time is long when an operator gets on the crane vehicle and the operation system lock device is released (operation selection). Since the engine continues idling during that time, it is possible to obtain effects such as fuel saving, exhaust, and noise reduction by stopping the engine during this work waiting time. Since it is a condition for stopping the engine that the vehicle gets off, an effective engine stop effect cannot be obtained.

  On the other hand, in the case of a crane vehicle, there is a case where the work is waited with a suspended load suspended from a wire suspended from the tip of the boom. In such a case, it is necessary to perform control so as not to stop the engine.

  Therefore, the present invention is intended to provide an engine control device that can realize an appropriate idling stop in consideration of the characteristics of crane work by a crane vehicle.

  An engine control device for a crane vehicle according to claim 1 of the present application operates a hydraulic pump using an engine as a power source, and drives a hydraulic actuator by discharge oil of the hydraulic pump based on an operation of a crane operating means. It is intended for an engine control device of a crane truck that lifts a suspended load with a wire suspended from the tip of a boom. And a crane operation detecting means for detecting whether or not the crane operating means is operated, a suspended load detecting means for detecting the presence or absence of a suspended load at the tip of the boom, and a crane operation based on a signal from the detecting means. Engine stop means for stopping the engine when a state where there is no load and a state where there is no suspended load continue for a preset time at the same time.

  Further, an engine control device for a crane vehicle described in claim 2 of the present application operates a hydraulic pump using an engine whose rotation is controlled by an accelerator operating means as a power source, and based on the operation of the crane operating means, An engine control device for a crane vehicle that drives a hydraulic actuator with discharged oil and lifts a suspended load with a wire suspended from the tip of a boom is an object. And an accelerator operation detecting means for detecting presence / absence of operation of the accelerator operating means, a crane operation detecting means for detecting presence / absence of operation of the crane operating means, and detecting presence / absence of a suspended load suspended at the tip of the boom. An engine stop that stops the engine when a state where there is no accelerator operation, a state where there is no crane operation, and a state where there is no suspended load continue for a preset time at the same time based on a signal from the detection means Means.

  In the crane vehicle engine control device according to claim 1 of the present application, the condition for stopping the engine is that the state in which there is no crane operation continues for a preset time based on a signal from the crane operation detection means. The engine can be stopped after confirming that there is no intention to continue the crane operation. Furthermore, since the engine stop condition is that the state in which there is no suspended load continues for a preset time based on a signal from the suspended load detecting means at the same time, there is a suspended load suspended at the tip of the boom. Therefore, it is possible to avoid stopping the engine when a crane operation for avoiding danger is required. As a result, an appropriate idling stop adapted to the characteristics of the crane work by the crane truck can be performed, and fuel saving, exhaust, noise reduction, and the like can be realized.

  In the crane vehicle engine control device according to claim 2 of the present application, in addition to the engine stop condition of the engine control device according to claim 1, a state in which no accelerator operation is performed is set in advance by a signal from the accelerator operation detection means. Therefore, the engine can be stopped after confirming more reliably that the operator does not intend to continue the crane work.

  The best mode for carrying out the invention will be described by applying the engine control device of the present invention to the rough terrain crane 1 shown in FIG. The rough terrain crane 1 has a swivel base 4 mounted on a traveling vehicle body 3 having front and rear outriggers 2 in a freely swingable manner, and a driver's seat 5 for traveling and crane operation is provided on one side of the swivel base 4. A telescopic boom 6 is pivotally attached to the rear part of the swivel 4 so that it can be raised and lowered. An engine 8 for power supply for traveling and crane work is disposed in the engine room 7 at the rear of the traveling vehicle body 3. A winch (not shown) is arranged at the rear part of the swivel base 4, and the wire 9 fed from the winch is hung around the tip sheave at the telescopic boom tip 10, and then the hanging load hook 11 is suspended. Yes. An accelerator operating means 12 for controlling the rotation of the engine 8 is installed in the cab 5. Further, in the cab 5, operating means 13 for hydraulic actuators such as an actuator for extending and retracting the telescopic boom 6, an actuator for driving the hoisting of the telescopic boom 6, an actuator for driving the winch and an actuator for driving the turning platform 4 are disposed. Has been.

  The rough terrain crane 1 operates the hydraulic pump by using the engine 8 as a power source, drives the hydraulic actuator by switching the hydraulic pump discharge oil by operating the crane operating means 13, and is suspended from the boom tip 10. The suspended load is lifted by the wire 9. The rough terrain crane 1 shown in FIG. 1 is in a crane working posture in which the outrigger 2 is grounded, the telescopic boom 6 is extended and raised. Moreover, the hanging load hook 11 suspended from the telescopic boom tip 10 has no suspended load 32 and is in a state of waiting for crane work. When such a crane work waiting state continues for a predetermined time, the engine 8 can be stopped.

  FIG. 2 shows a block diagram of an engine control apparatus according to an embodiment of the present invention. The engine 8 disposed in the engine room 7 drives a hydraulic pump 21, and the hydraulic oil discharged from the hydraulic pump 21 is operated to switch the direction and flow rate by the crane operation hydraulic valve 22 and then to the hydraulic actuator 23. Supplied. An oil path to the unload valve 24 is branched in an oil path between the hydraulic pump 21 and the crane operation hydraulic valve 22. By operating the unload valve 24, the hydraulic oil to the hydraulic actuator 23 is supplied. Supply can be stopped.

  The accelerator operating means 12 includes an accelerator pedal 26 and an accelerator signal generating unit 25, and the accelerator signal generating unit 25 sends an accelerator signal corresponding to the depression amount of the accelerator pedal 26 to the lower controller 27. The lower controller 27 has a function as an engine control unit, and outputs an accelerator signal from the accelerator operation means 12 to the governor control unit 28 of the engine 8. The governor control unit 28 controls the rotation of the engine 8 based on the received accelerator signal. The lower controller 27 may be configured as a part of MDT (which is an abbreviation of multiplex data transmitter, which is a multiplex data transfer device) provided in the rough terrain crane 1.

  Reference numeral 30 denotes crane state detection means, and the detection signal of the crane state detection means 30 is sent to the upper controller 31. The concrete contents of the crane state detection means 30 include a length detector for the telescopic boom 6, a undulation angle detector, a swivel angle detector for the swivel 4, an overhang width detector for the outrigger 2, and a load on the telescopic boom 6. It consists of a detector and the like. The upper controller 31 has the function of a crane control unit, and works as an overload prevention device for the rough terrain crane 1 in combination with the crane state detection means 30. When the load acting on the telescopic boom 6 becomes an overload state, an operation signal is output from the upper controller 31 to the unload valve 24 described above, and the operation of the hydraulic actuator 23 is stopped.

  The upper controller 31 also calculates a lifting load applied to the telescopic boom tip 10 based on a detection signal from the crane state detection means 30. Since the lifting load is a combined load of the hanging load hook 11 and the hanging load 32, the lifting hook is in a state of no lifting load where the lifting load 32 is lowered to the ground as in the rough terrain crane 1 shown in FIG. Only 11 weights are calculated. The upper controller 31 stores the weight of the lifting hook 11 in advance, and when the calculated lifting load becomes the same as the weight of the lifting hook 11, there is no hanging load suspended from the boom tip 10. And a no-load signal is output to the lower controller 27. Thus, the upper controller 31 functions as a suspended load detection means described in the claims. The upper controller 31 may be configured as a part of AML (abbreviation of automatic moment limiter, which is an overload prevention device) provided in the rough terrain crane 1.

  An operation signal from the crane operation means 13 is output to the upper controller 31, and further, the operation signal is output from the upper controller 31 to the crane operation hydraulic valve 22. That is, the hydraulic actuator 23 is operated by switching the crane operation hydraulic valve according to the operation of the crane operation means 13. On the other hand, when the operation signal is not input from the crane operation means 13, the upper controller 31 outputs a crane non-operation signal to the lower controller 27. Thus, the upper controller 31 also functions as a crane operation detection means described in the claims.

  The operation of the above-described engine control device will be described based on the flowchart shown in FIG. First, the power is turned on by an operator who has boarded the cab 5 of the rough terrain crane 1 (S1). Next, the engine 8 is started by the operator (S2). The lower controller 27 determines whether or not the above-described no-load signal is received from the upper controller 31 (S3). When the no-load signal is not received, that is, when the upper controller 31 determines that the load is suspended from the telescopic boom tip 10, the operation signal from the accelerator operating means 12 is sent to the governor control unit 28. Is continuously output, and the engine 8 continues to rotate (S4).

  On the other hand, when it is determined that the lower controller 27 has received a no-load signal from the upper controller 31, it is next determined whether or not a crane operation-free signal has been received from the upper controller 31 (S5). When no crane operation no signal is received, that is, when the upper controller 31 receives an operation signal from the crane operation means 13, the operation signal from the accelerator operation means 12 is continuously output to the governor control unit 28, The engine 8 continues to rotate (S4).

  On the other hand, when it is determined that the lower controller 27 has received the crane operation no signal from the upper controller 31, the no load signal and the crane operation no signal are continuously received from the upper controller 31 for a preset time at the same time. Is determined (S6). The continuation time for determining whether or not the engine can be stopped is set to an optimum time by analyzing the work content of the rough terrain crane 1 at the actual work site. Note that a time adjusting means may be provided in the cab 5 so that the operator can adjust the set time by the time adjusting means according to different crane work contents for each work site. When the lower controller 27 determines that the preset time has not been continued, the operation signal from the accelerator operating means 12 is continuously output to the governor control unit 28, and the engine 8 continues to rotate ( S4).

  On the other hand, when it is determined that the lower controller 27 continuously receives the no-loading signal and the crane operation-free signal from the upper controller 31 at the same time for a preset time, the lower controller 27 sends a signal to the governor control unit 28. Then, the engine stop signal is output, the fuel supply is stopped, and the engine 8 stops rotating (S7). Since the engine 8 is automatically stopped in this way, the idle idle rotation of the engine 8 for a long time during the work waiting time of the crane operation of the rough terrain crane 1 is prevented, and fuel saving, exhaust, and noise are prevented. Reduction and the like can be achieved. In addition, the operator can easily grasp that the crane work is resumed by continuously boarding the cab 5 and continuously monitoring the progress of the surrounding work. Then, when restarting the crane work, the operator may start the engine 8 again (S2).

  The engine control apparatus according to the second embodiment will be described based on the block diagram of the engine control apparatus shown in FIG. 2 and the operation flowchart of the engine control apparatus shown in FIG. When the accelerator operation signal is not output from the accelerator operation means 12, the lower controller 27 shown in FIG. 2 generates an accelerator operation no signal internally, and the accelerator operation no signal is set for a preset time. It is different from the above-described engine control apparatus according to the first embodiment in that continuing is also determined as a condition for stopping the engine. In this case, the lower controller 27 functions as the accelerator operation detecting means described in the claims.

  The flowchart shown in FIG. 4 differs from the flowchart shown in FIG. 3 (Embodiment 1) in that the lower controller 27 has a part for determining whether or not an accelerator operation absence signal is generated (S6). Further, the difference is that it is determined not only that the no-loading signal and the crane operation-free signal are received from the upper controller 31, but also whether or not the accelerator operation-free signal continues for a preset time at the same time ( S7). When the lower controller 27 determines that the no-loading signal, the crane operation-free signal, and the accelerator operation-free signal continue at the same time for a preset time, the lower controller 27 causes the governor control unit 28 to stop the engine. A signal is output, and the engine 8 stops rotating (S8). Thus, since the presence / absence of the accelerator operation is also determined, the operator's intention to continue the crane work can be more reliably reflected in the engine stop control.

  Note that the following conditions may be added to the engine control in order to perform the control to continue the idling rotation when the engine 8 is started in cold weather and the engine 8 needs to be warmed up. (1) An engine water temperature is input to the lower controller 27, and the lower controller 27 determines that the engine water temperature is lower than a specified temperature. (2) The idling rotation adjustment volume is set to a higher rotational speed than the normal idling rotational speed. (3) A request signal for warm-up operation is issued from the governor control unit 28 to the lower controller 27. (4) Although the accelerator signal for idling rotation is output to the governor control unit 28, the engine speed is higher than the idling rotation by the control of the governor control unit 28. By adding such a condition to the control condition of the engine control device, the idling rotation for warming up the engine 8 can be automatically continued when the warming-up operation is required.

A rough terrain crane to which an engine control device according to the invention of the present application is applied. It is a block diagram of the engine control device concerning the invention of this application. 3 is a flowchart of engine control according to the first embodiment. 6 is a flowchart of engine control according to a second embodiment.

Explanation of symbols

1: rough terrain crane 6: telescopic boom 8: engine 9: wire 12: accelerator operating means 13: crane operating means 21: hydraulic pump 23: hydraulic actuator 27: lower controller 30: crane state detecting means 31: upper controller 32: suspended load

Claims (2)

A crane vehicle that operates a hydraulic pump using an engine as a power source, drives a hydraulic actuator with discharge oil of the hydraulic pump based on operation of a crane operating means, and lifts a suspended load with a wire suspended from the tip of a boom. In the engine control device,
Crane operation detecting means for detecting presence / absence of operation of the crane operating means, suspended load detecting means for detecting presence / absence of a suspended load suspended from a boom tip, and no crane operation based on a signal from the detecting means An engine control device for a crane vehicle, comprising: engine stop means for stopping the engine when the state and the state of no suspended load continue simultaneously for a preset time. The hydraulic pump is operated using the engine whose rotation is controlled by the accelerator operating means as a power source, and the hydraulic actuator is driven by the oil discharged from the hydraulic pump based on the operation of the crane operating means, and is suspended by a wire suspended from the tip of the boom. In an engine control device for a crane truck that lifts a load,
Accelerator operation detecting means for detecting presence / absence of operation of the accelerator operation means, crane operation detection means for detecting presence / absence of operation of the crane operation means, and suspension for detecting presence / absence of a suspended load suspended from a boom tip. An engine stop unit that stops the engine when a state in which no accelerator operation is performed, a state in which no crane operation is performed, and a state in which there is no suspended load continue for a preset time at the same time based on a signal from the detection unit; An engine control device for a crane truck, comprising:

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