JP2012162952A - Working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a working machine which can prevent an engine stalling immediately after the start of an engine and reduce a sense of incongruity for an operator.SOLUTION: A working machine includes a hydraulic pump 20 driven by an engine 10, a hydraulic actuator 30 operated by the hydraulic pump 20, an operation means 40 for instructing the operation of the hydraulic actuator 30, and an operation speed control device for controlling the flow rate of hydraulic oil supplied to the hydraulic actuator 30 when its operation is instructed by the operation means 40 immediately after the start of the engine 10. If an operator operates a working machine immediately after the start of the engine, the engine stalling can be prevented. Since the working machine operates at low speed according to the operation of the operator, a sense of incongruity for the operator can be reduced.

Description

  The present invention relates to a work machine. More specifically, the present invention relates to a working machine that does not stall an engine even if an actuator is operated immediately after the engine is started.

  In general, work machines such as aerial work platforms and cranes are not stable immediately after the engine is started or immediately after the engine is restarted from an idling stop state. When the machine is operated, the load on the engine increases and the engine may stall.

On the other hand, Patent Document 1 describes a technique for delaying the operation signals of the operation lever and the operation switch so that the work machine does not operate until a certain time has elapsed after the engine is started.
In this way, even if the operator operates the work machine when the engine rotation is not stable immediately after starting the engine, the operation is not accepted, so the engine is not loaded and the engine stalls. Can be prevented.

However, in the above prior art, there is a problem that the worker feels a sense of incongruity because the work machine does not operate although it is operated.
For example, in the case of an aerial work vehicle, the worker starts the engine from a bucket far away from the engine and performs operations such as expansion and contraction of the boom. It may be misunderstood as not being done.

JP 2010-84475 A

  In view of the above circumstances, an object of the present invention is to provide a work machine that can prevent an engine stall immediately after the engine is started and can reduce an uncomfortable feeling of an operator.

A work machine according to a first aspect of the present invention is directed to an engine, an actuator that operates by driving the engine, an operation unit that instructs the operation of the actuator, and an operation of the actuator is instructed from the operation unit. And an operating speed control device that controls the operating speed of the actuator within a range in which the load applied to the engine is a load that does not stall the engine until the engine rotation is stabilized.
A work machine according to a second aspect of the present invention includes an engine, a hydraulic pump driven by the engine, a hydraulic actuator operated by hydraulic oil supplied by the hydraulic pump, operating means for instructing the operation of the hydraulic actuator, When the operation of the hydraulic actuator is instructed from the operation means, the hydraulic actuator is within a range in which the load applied to the engine is a load that does not stall the engine until the engine rotation is stabilized after the engine is started. And an operating speed control device for controlling the flow rate of the hydraulic oil supplied to the vehicle.
According to a third aspect of the present invention, there is provided a work machine according to the second aspect, further comprising engine rotation detecting means for detecting whether or not the engine is rotating, and the operating speed control device is instructed to operate the hydraulic actuator by the operating means. When the engine rotation detecting means detects the engine rotation until a predetermined time elapses, the operation supplied to the hydraulic actuator is within a range where the load applied to the engine does not stall the engine. It is characterized by controlling the flow rate of oil.
According to a fourth aspect of the present invention, there is provided the work machine according to the third aspect, wherein the operating speed control device includes a flow rate control valve that controls a flow rate of the hydraulic oil supplied to the hydraulic actuator, and an operation of the hydraulic actuator from the operating means. When instructed, the operating speed of the hydraulic actuator is controlled within a range in which the load applied to the engine is a load that does not cause an engine stall until a predetermined time elapses after the engine rotation detecting means detects the engine rotation. An operation speed calculating means for calculating, and a valve driving means for driving the flow control valve so that the operation speed of the hydraulic actuator becomes the operation speed calculated by the operation speed calculating means.
According to a fifth aspect of the work machine, in the fourth aspect, the operating speed control device controls the rotational speed of the engine so that the operating speed of the hydraulic actuator is equal to the operating speed calculated by the operating speed calculating means. And an engine speed control means.

According to the first aspect of the present invention, since the operating speed of the actuator is controlled within a range in which the load applied to the engine is a load that does not cause the engine stall until the engine rotation is stabilized after the engine is started. Even if the worker operates the work machine, the load on the engine is not excessive, and the engine can be prevented from stalling. Further, since the work machine operates at a low speed in accordance with the operation of the worker, it is possible to reduce the uncomfortable feeling of the worker.
According to the second aspect of the present invention, the flow rate of the hydraulic oil supplied to the hydraulic actuator is controlled within a range in which the load applied to the engine is a load that does not cause the engine stall until the engine rotation is stabilized after the engine is started. Therefore, the operating speed of the hydraulic actuator is controlled, and even if an operator operates the work machine immediately after starting the engine, the load on the engine is not excessive, and the engine can be prevented from stalling. Further, since the work machine operates at a low speed in accordance with the operation of the worker, it is possible to reduce the uncomfortable feeling of the worker.
According to the third aspect of the invention, the engine rotation is determined to be stable when a predetermined time has elapsed after the engine rotation detection means has detected the engine rotation. Easy.
According to the fourth aspect of the present invention, the flow control valve, the operating speed calculating means, and the valve driving means are within a range in which the load applied to the engine is a load that does not cause the engine to stall until the predetermined time elapses after the engine is started. Since the flow rate of hydraulic oil supplied to the hydraulic actuator is controlled, the operating speed of the hydraulic actuator is controlled, and even if an operator operates the work machine immediately after starting the engine, the load on the engine does not become excessive. , Engine stall can be prevented. Further, since the work machine operates at a low speed in accordance with the operation of the worker, it is possible to reduce the uncomfortable feeling of the worker.
According to the fifth aspect of the present invention, the engine load is not stalled until a predetermined time elapses after the engine is started by the flow rate control valve, the operation speed calculation means, the valve drive means, and the engine speed control means. Since the flow rate of hydraulic oil supplied to the hydraulic actuator is controlled within the load range, the operating speed of the hydraulic actuator is controlled, and even if an operator operates the work machine immediately after starting the engine, it is applied to the engine. The load does not become excessive, and engine stall can be prevented. Further, since the work machine operates at a low speed in accordance with the operation of the worker, it is possible to reduce the uncomfortable feeling of the worker.

1 is a block diagram of a work machine according to an embodiment of the present invention. It is a timing chart of the work machine. It is a timing chart in other conditions of the work machine. It is a timing chart in other conditions of the working machine. It is a timing chart in other conditions of the working machine. It is a timing chart of the working machine which concerns on other embodiment of this invention. It is a timing chart of the working machine which concerns on other embodiment of this invention.

Next, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a work machine according to an embodiment of the present invention includes an engine 10, a hydraulic pump 20 driven by the engine 10, and a plurality of hydraulic actuators operated by hydraulic oil supplied by the hydraulic pump 20. 30A, 30B, 30C, operating means 40A, 40B, 40C for instructing the operations of the hydraulic actuators 30A, 30B, 30C, and a controller 50 for controlling the operating speed of the hydraulic actuators 30A, 30B, 30C. I have.

Here, the work machine refers to a machine that performs a predetermined work by operating an actuator attached to a movable part by driving an engine, such as an aerial work vehicle, a crane, a bridge inspection car, an excavator, a hydraulic excavator, a wheel. A loader and the like are included. The hydraulic actuator is a hydraulic cylinder or a hydraulic motor. For example, in the case of an aerial work vehicle, the boom is extended and retracted, the swing body is swung, the outrigger is extended, retracted, and a traveling body such as a wheel or a crawler is used. It is used for traveling and the like, and in the case of a crane, it is used for boom expansion / contraction, undulation, jib tilt, winch hoisting / lowering, revolving body turning, outrigger extension, storage and the like.
Although there are three hydraulic actuators 30A, 30B, and 30C in FIG. 1, a smaller or larger number of hydraulic actuators may be provided. The engine 10 may be the same as the vehicle engine, or may be an engine different from the vehicle engine.

The hydraulic pump 20 and the hydraulic actuators 30A, 30B, and 30C are connected via electromagnetic proportional directional flow control valves 21A, 21B, and 21C, respectively. The electromagnetic proportional directional flow control valve is a control valve capable of simultaneously switching the direction of hydraulic oil and controlling the flow rate by controlling the current supplied to the solenoid.
The electromagnetic proportional directional flow control valves 21A, 21B, and 21C in this embodiment are three-position switching valves, and the pressure oil from the hydraulic pump 20 flows into the rod side of the hydraulic cylinders 30A and 30B or the forward rotation side of the hydraulic motor 30C. From the hydraulic pump 20 on the piston position of the hydraulic cylinders 30A, 30B or on the reverse side of the hydraulic motor 30C, the I position to be stopped, the II position where the inflow / outflow of pressure oil from the hydraulic cylinders 30A, 30B or the hydraulic motor 30C is stopped. There is a III position where pressure oil flows in. Therefore, by controlling the current supplied to the solenoids of the electromagnetic proportional directional flow control valves 21A, 21B, and 21C, the expansion and contraction of the hydraulic cylinders 30A and 30B can be switched, and the operation speed can be controlled. Further, the forward rotation and the reverse rotation of the hydraulic motor 30C can be switched, and the rotation speed can be controlled.
The electromagnetic proportional directional flow control valve corresponds to a “flow control valve” recited in the claims. Further, instead of the electromagnetic proportional directional flow control valve, a flow control valve and a directional control valve may be combined.

  A relief valve 22 and an unload valve 23 are connected to the hydraulic circuit that connects the hydraulic pump 20 and each of the hydraulic actuators 30A, 30B, and 30C to prevent the pressure in the hydraulic circuit from becoming high, Safety measures are taken to regulate operation in the event of a danger.

The operation means 40A, 40B, and 40C include operation levers 41A, 41B, and 41C and operation output means 42A, 42B, and 42C that output the operation amount a of the operation levers 41A, 41B, and 41C, respectively.
The operation output means 42A, 42B, and 42C in the present embodiment are sensors that detect the operation amount a of the operation levers 41A, 41B, and 41C, and can output the detected operation amount a as an electrical signal. The operation output means 42A, 42B, and 42C are connected to an operation input means 51 of the controller 50, which will be described later, so that the operation amount a of each operation lever 41A, 41B, 41C can be output to the operation input means 51. .
Instead of the operation lever, other operation means such as an operation switch may be used. Further, the operation output means 42A, 42B, 42C and the operation input means 51 may be physically connected such as a control cable instead of being electrically connected.

The controller 50 includes operation input means 51, operating speed calculation means 52, valve drive means 53, and engine speed control means 54.
The operation input means 51 receives the operation amount a of the operation levers 41A, 41B, 41C from the operation output means 42A, 42B, 42C, and outputs the operation amount a to the operation speed calculation means 52. Specifically, when the operation output means 42A, 42B, 42C and the operation input means 51 are electrically connected, an analog-digital conversion circuit is used for the operation input means 51.
In FIG. 1, the operation input means 51 and the operation speed calculation means 52 are connected by a single arrow, but the operation speed calculation means 52 includes a plurality of operation output means 42A, 42B, and 42C, respectively. The operation amount is entered.

Engine rotation detection means 61 for detecting whether or not the engine 10 is rotating is attached to the engine 10. The engine rotation detecting means 61 is connected to the operating speed calculating means 52 so that the detection result b can be output to the operating speed calculating means 52.
Specifically, the engine rotation detecting means 61 may be one that detects whether the engine 10 is rotating by detecting a voltage or current output from a generator connected to the engine 10. In addition, the engine rotation detection means 61 may detect an engine rotation pulse. Moreover, it is not limited to the one that is directly attached to the engine 10, but may be one that detects the rotation of the hydraulic pump 20, or one that detects the hydraulic pressure of the hydraulic circuit.

The operation speed calculation means 52 is constituted by a CPU, a memory, and the like, and each hydraulic pressure is calculated from the operation amount a input from the operation input means 51 and the engine rotation detection result b input from the engine rotation detection means 61. The operating speed c of the actuators 30A, 30B, 30C is calculated. More specifically, when the operation amount a is input from the operation input unit 51, the operation speed calculation unit 52 measures the time from when the engine rotation detection result b is input from the engine rotation detection unit 61. The operating speed c of each of the hydraulic actuators 30A, 30B, and 30C is calculated within a range in which the load applied to the engine 10 is a load that does not stall the engine until a predetermined time elapses. The calculation method will be described in detail later.
The term “when the operation means is instructed to operate the hydraulic actuator” in the claims refers to a period during which the operation amount a is input from the operation input means 51 in addition to the start time of the operation instruction ( period t ₃ or later in FIGS. 2-7 below) is also a concept including.

Further, the operating speed calculating means 52 outputs the calculated operating speed c to the valve driving means 53 and the engine speed control means 54.
In FIG. 1, the operation input means 51, the valve driving means 53, and the engine speed control means 54 are connected by a single arrow, but the valve driving means 53 and the engine speed control means 54 are The operating speeds of the plurality of hydraulic actuators 30A, 30B, 30C are input.

The valve driving means 53 is electrically connected to the solenoid of each electromagnetic proportional direction flow control valve 21A, 21B, 21C, and can control the current supplied to the solenoid.
The valve drive means 53 is configured to output each electromagnetic proportional direction flow rate based on the operation speed c input from the operation speed calculation means 52 so that the operation speeds of the hydraulic actuators 30A, 30B, 30C coincide with the operation speed c. Current is supplied to the solenoids of the control valves 21A, 21B, and 21C to control the flow rate. By performing flow rate control with the electromagnetic proportional direction flow rate control valves 21A, 21B, and 21C, it is possible to control the operating speed of each of the hydraulic actuators 30A, 30B, and 30C.

Based on the operating speed c input from the operating speed calculating means 52, the engine speed control means 54 is configured so that the operating speeds of the hydraulic actuators 30A, 30B, 30C can operate at the operating speed c. The number of revolutions is controlled. In other words, the engine rotational speed control means 54 controls the rotational speed of the hydraulic pump 20 to hydraulically supply hydraulic oil at a flow rate necessary for each hydraulic actuator 30A, 30B, 30C to operate at the target operating speed c. It is for supplying to a circuit.
An engine control unit 62 is connected to the engine 10, and the engine speed control means 54 is connected to the engine control unit 62. Therefore, the engine speed control means 54 outputs an accelerator signal to the engine control unit 62, so that the speed of the engine 10 can be controlled via the engine control unit 62.

An engine starter 63 is connected to the engine 10, and the engine starter 63 is connected to engine start operation means 64.
The engine start operation means 64 is, for example, a push button switch, and is used by a worker to start the engine 10 when pressed. When the engine start operation means 64 is operated, an operation signal d is input from the engine start operation means 64 to the engine start device 63.
The engine starter 63 outputs an engine start output e to the engine 10 in response to the input operation signal d, and starts the engine 10. Specifically, a cell motor is used as the engine starting device 63.
The engine start operation means 64 is not limited to a physical switch, and may be a software switch. Specifically, the condition for restarting the engine 10 from the idling stop state may be determined by software, and the operation signal d may be output to the engine starting device 63 when the restarting condition is satisfied.
Furthermore, the controller 50 may determine a condition for restarting the engine 10 and output the operation signal d from the controller 50 to the engine starting device 63 when the restarting condition is satisfied.

  The “operation speed control device” described in the claims corresponds to the controller 50 and the electromagnetic proportional directional flow control valve 21 in the present embodiment.

  Next, the operation of the work machine according to the present embodiment will be described with reference to FIG. In the following, for simplicity of explanation, only one hydraulic actuator 30 and one operation means 40 corresponding to the hydraulic actuator 30 will be described, but the operation is the same even if the number of these increases.

First, when the operator operates the engine start operation means 64 or when it is determined that the engine start operation means 64 satisfies the condition for restarting the engine 10 from the idling stop state, the operation signal d is output to the engine start device 63. (T ₁ ).
The engine starter 63 outputs the engine start output e to the engine 10 in response to the rising of the input operation signal d, and starts the engine 10 (t ₁ ).

When the engine 10 is started, the engine rotation detection unit 61 detects the engine rotation, and outputs a detection result b indicating that the engine 10 is rotating to the operating speed calculation unit 52 (t ₂ ).
Then, the operating speed calculation means 52 starts measuring the time after the engine rotation detection result b is input, and determines whether or not a predetermined time has passed. Hereinafter, this predetermined time is referred to as unstable time.
As the unstable time, a time required until the engine rotation is stabilized after the engine 10 is started is set, for example, 2 seconds. This unstable time is stored in advance in the operating speed calculation means 52.

If the operator operates the operation lever 41 before the unstable time has elapsed after the engine rotation detection means 61 detects the engine rotation, the operation amount a is output from the operation input means 51 to the operation speed calculation means 52. (T ₃ ).
Then, the operating speed calculation means 52 calculates the unstable time maximum operating speed c1 that is the maximum operating speed of the hydraulic actuator 30 within a range where the load applied to the engine 10 is a load that does not stall the engine. Then, the operating speed calculation means 52 gradually increases the operating speed c so as to approach the unstable time maximum operating speed c1 as time elapses, and the operating speed c is increased to the valve driving means 53 and the engine speed control means 54. Output to.
As a result, the hydraulic actuator 30 is slowly activated even within the unstable time.
The unstable time maximum operating speed c1 may be stored in advance in the operating speed calculation means 52 as a predetermined constant, or may be calculated from various conditions such as the rotational speed of the engine 10.

The operating speed calculation means 52 prevents the operating speed c from being increased any more when the operating speed c increases to coincide with the unstable time maximum operating speed c1 (t ₄ ). Then, the operating speed c is output within a range not exceeding the unstable time maximum operating speed c1 until the unstable time elapses.
Therefore, even if an operator operates the work machine within an unstable time immediately after the start of the engine, the load on the engine 10 does not become excessive, and the engine can be prevented from stalling. Further, since the work machine operates at a low speed in accordance with the operation of the worker, it is possible to reduce the uncomfortable feeling of the worker.

In addition, while the hydraulic actuator 30 is operating within the unstable time (t _{3 to} t ₅ ), an alarm may be issued with a lamp or sound. This is because the hydraulic actuator operates at a lower speed than usual within the unstable time, and therefore it can be recognized that the speed is lower than usual by issuing an alarm with a lamp or sound.

When the unstable time elapses (t ₅ ), the operation speed calculation unit 52 calculates a normal operation speed c2 that is a normal operation speed corresponding to the operation amount a. Then, the operating speed calculation means 52 gradually increases the operating speed c so as to approach the normal operating speed c2 as time elapses, and outputs the operating speed c to the valve driving means 53 and the engine speed control means 54. .
Therefore, the hydraulic actuator 30 is slowly activated again after an unstable time has elapsed, and then operates at an operating speed corresponding to the operation amount a.

  In the present embodiment, the hydraulic actuator 30 is slowly activated within the unstable time and after the unstable time has elapsed, but instead of this, a normal activation may be used. However, the load can be prevented from being swayed by slowly starting. Further, in the case of an aerial work vehicle, the shock of operation is reduced by the slow start, and the safety for the worker can be improved.

Next, based on FIG. 3, the operation under other conditions of the work machine according to the present embodiment will be described.
FIG. 3 shows that the operator operates the operation lever 41 between the time when the operator operates the engine start operation means 64 (t ₁ ) and the time when the engine rotation detection means 61 detects the engine rotation (t ₂ ). The operation amount a is output from the operation input means 51 to the operation speed calculation means 52 (t ₃ ).

In this case, even if the operation amount a is input, the operation speed calculation unit 52 does not output the operation speed c until the engine rotation detection unit 61 detects the engine rotation (t ₂ ). That is, the hydraulic actuator 30 is controlled not to operate until the rotation of the engine 10 is detected.

When the engine rotation detecting unit 61 detects the engine rotation (t ₂ ), the operating speed calculating unit 52 has a maximum operating speed of the hydraulic actuator 30 within a range where the load applied to the engine 10 does not stall the engine. A certain unstable time maximum operating speed c1 is calculated. Then, the operating speed calculation means 52 gradually increases the operating speed c so as to approach the unstable time maximum operating speed c1 as time elapses, and the operating speed c is increased to the valve driving means 53 and the engine speed control means 54. Output to.
As a result, the hydraulic actuator 30 is slowly activated.

After that, when the operating speed c increases and coincides with the unstable time maximum operating speed c1 (t ₄ ), the operating speed calculation means 52 prevents the operating speed c from increasing further. Then, the operating speed c is output within a range not exceeding the unstable time maximum operating speed c1 until the unstable time elapses. When the unstable time elapses (t ₅ ), the operation speed calculation unit 52 calculates a normal operation speed c2 that is a normal operation speed corresponding to the operation amount a. Then, the operating speed calculation means 52 gradually increases the operating speed c so as to approach the normal operating speed c2 as time elapses, and outputs the operating speed c to the valve driving means 53 and the engine speed control means 54. .

  Therefore, even if an operator operates the work machine within an unstable time immediately after the start of the engine, the load on the engine 10 does not become excessive, and the engine can be prevented from stalling. Further, since the work machine operates at a low speed in accordance with the operation of the worker, it is possible to reduce the uncomfortable feeling of the worker.

Next, based on FIG. 4, the operation of the working machine according to the present embodiment under still other conditions will be described.
In FIG. 4, the worker operates the engine start operation means 64 (t ₁ ), the engine rotation detection means 61 detects the engine rotation (t ₂ ), and the unstable period has elapsed (t ₅ ). A case where the operator operates the operation lever 41 and the operation amount a is output from the operation input means 51 to the operation speed calculation means 52 (t ₃ ) is shown.

  In this case, the operation speed calculation means 52 calculates a normal operation speed c2 that is a normal operation speed corresponding to the operation amount a. Then, the operating speed calculation means 52 gradually increases the operating speed c so as to approach the normal operating speed c2 as time elapses, and outputs the operating speed c to the valve driving means 53 and the engine speed control means 54. That is, the work machine only performs an operation according to the operation amount a.

Next, based on FIG. 5, the operation of the working machine according to the present embodiment under still other conditions will be described.
FIG. 5 shows a case where the operation amount a of the operation lever 41 operated by the worker is small under the conditions shown in FIG. 2 (t ₃ ).

In this case, the operating speed calculation means 52 calculates the unstable time maximum operating speed c1 that is the maximum operating speed of the hydraulic actuator 30 within a range where the load applied to the engine 10 is a load that does not stall the engine. Further, the operating speed calculation means 52 calculates a normal operating speed c2 that is a normal operating speed corresponding to the operation amount a.
When the operation amount a is small and the normal operation speed c2 is lower than the unstable time maximum operation speed c1, the operation speed calculation means 52 operates so as to approach the normal operation speed c2 over time. The operating speed c is output to the valve drive means 53 and the engine speed control means 54.
As a result, the hydraulic actuator 30 is slowly activated and can perform the same operation as usual.

  Therefore, even if an operator operates the work machine within an unstable time immediately after the start of the engine, the load on the engine 10 does not become excessive, and the engine can be prevented from stalling. Further, since the work machine operates according to the operation of the worker, the worker does not feel uncomfortable.

(Other embodiments)
In the above embodiment, the operation speed c is gradually increased after the manipulated variable a is output (t ₃ ), after the unstable period has elapsed (t ₅ ), and the like, but instead, FIG. As shown, the operating speed c may be changed stepwise. In the above embodiment, the hydraulic actuator 30 is slowly activated, but the response of the hydraulic actuator 30 can be increased by changing the speed c in a stepped manner.
The operating speed c output from the operating speed calculating means 52 to the valve driving means 53 and the engine speed control means 54 may be gradually increased, or may be gradually increased and stepped. You may combine things. For example, the operating speed c output to the valve driving means 53 may be gradually increased, and the operating speed c output to the engine speed control means 54 may be changed stepwise.

In the above embodiment, when the operation amount a is output from the operation input unit 51 (t ₃ ) after the engine rotation detection unit 61 detects the engine rotation (t ₂ ), the operating speed c is increased. Instead, as shown in FIG. 7, after the engine start output e from the engine start device 63 falls (t ₆ ), when the operation amount a is output from the operation input means 51 (t ₃ ) The operating speed c may be increased.
In this way, since the engine 10 has been reliably started, the actuator can be operated more stably.

In the above embodiment, the period from when the engine 10 is started to when the engine rotation is stabilized is determined as the time until the unstable time elapses after the engine rotation detection means 61 detects the engine rotation. Instead of this, a means for directly or indirectly detecting the state of engine rotation may be used. For example, a means for detecting the output torque of the engine 10 or a means for detecting the vibration of the engine 10 may be used.
However, the embodiment described above is preferable because it is easier to make a determination than when detecting the state of engine rotation.

  Moreover, although the working machine using a hydraulic actuator as the actuator has been described in the above embodiment, the present invention can also be applied to the case of using various actuators that can suppress the engine load by suppressing the operation speed. For example, it can be applied to a hybrid work vehicle. Here, a hybrid work vehicle is an engine-driven and motor-driven hybrid that drives a generator with an engine, stores the electric power generated by the generator in a storage battery, and moves the motor with the electric power stored in the storage battery It is a car. In this case, the generator corresponds to the actuator.

  Further, the hydraulic pump 20 may be a variable displacement pump, and the discharge amount of the variable displacement pump may be controlled to reduce the work load and the engine load.

DESCRIPTION OF SYMBOLS 10 Engine 20 Hydraulic pump 21 Electromagnetic proportional direction flow control valve 30 Hydraulic actuator 40 Operation means 50 Controller 51 Operation input means 52 Operating speed calculation means 53 Valve drive means 54 Engine rotation speed control means 61 Engine rotation detection means

Claims (5)

Engine,
An actuator that operates by driving the engine;
Operating means for instructing the operation of the actuator;
When the operation of the actuator is instructed from the operation means, the load of the engine is within a range in which the load applied to the engine does not stall until the engine rotation is stabilized after the engine is started. An operating speed control device that controls the operating speed. Engine,
A hydraulic pump driven by the engine;
A hydraulic actuator operated by hydraulic oil supplied by the hydraulic pump;
Operating means for instructing the operation of the hydraulic actuator;
When the operation of the hydraulic actuator is instructed from the operation means, the hydraulic pressure is within a range in which the load applied to the engine is a load that does not cause engine stall until the engine rotation is stabilized after the engine is started. And a working speed control device for controlling a flow rate of the working oil supplied to the actuator. Comprising engine rotation detecting means for detecting whether or not the engine is rotating;
The operating speed control device includes:
When the operation means instructs the operation of the hydraulic actuator, a range in which the load applied to the engine is a load that does not cause an engine stall until a predetermined time elapses after the engine rotation detection means detects the engine rotation. The work machine according to claim 2, wherein a flow rate of the hydraulic oil supplied to the hydraulic actuator is controlled. The operating speed control device includes:
A flow rate control valve for controlling the flow rate of the hydraulic oil supplied to the hydraulic actuator;
When the operation means instructs the operation of the hydraulic actuator, a range in which the load applied to the engine is a load that does not cause an engine stall until a predetermined time elapses after the engine rotation detection means detects the engine rotation. Operating speed calculating means for calculating the operating speed of the hydraulic actuator,
4. The work machine according to claim 3, further comprising valve drive means for driving the flow control valve so that an operating speed of the hydraulic actuator becomes an operating speed calculated by the operating speed calculating means. The operating speed control device includes:
5. The work machine according to claim 4, further comprising engine speed control means for controlling the engine speed so that an operating speed of the hydraulic actuator becomes an operating speed calculated by the operating speed calculating means. .

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