JP4398830B2 - Construction machinery - Google Patents

Description

  The present invention relates to a construction machine such as a hydraulic excavator including a flow rate restricting means for limiting a supply flow rate to a hydraulic actuator to a predetermined low flow rate by a vehicle body controller.

  2. Description of the Related Art Conventionally, an anti-theft control device that outputs a signal related to anti-theft, for example, a signal that inhibits driving of an engine, that is, an anti-theft controller, and an airframe controller that controls an engine speed and a supply flow rate to a hydraulic actuator, namely a vehicle body Patent Document 1 discloses a technique that includes a controller and connects the antitheft controller and the vehicle body controller via communication means such as a communication line.

  In this prior art, when a signal for preventing the starter from being output is output from the antitheft controller in order to prevent theft, the starter of the engine is blocked in accordance with this signal and transmitted via a communication line. In response to the above-described signal, the vehicle body controller operates to prevent the supply of pressure oil to the hydraulic actuator. As a result, even if a construction machine equipped with this anti-theft device is stolen, the work machine cannot be operated, and a large check force against the theft is ensured.

  By the way, at work sites in towns, etc., the situation where you want to move the construction machine urgently for some reason during the operation of the anti-theft system, or the situation where you want to lower the boom urgently when the construction machine is a hydraulic excavator etc. May occur. In such an emergency situation, in the above-described prior art, the operation of the anti-theft system must be canceled by inputting a personal identification number, and thereby the blocking of the supply of pressure oil to the hydraulic actuator by the vehicle body controller must be canceled. . At that time, if the operator does not know the personal identification number, there is a risk that a great deal of time will be lost.

  That is, in the above-described prior art, the password entry operation is involved for releasing the anti-theft system, which makes the release work complicated. Accordingly, the body controller prevents pressure oil from being supplied to the hydraulic actuator. It may take time to cancel the release, move the traveling body, or move the work machine such as a boom, and may not be able to realize a quick response in an emergency while the antitheft system is operating.

  Therefore, the applicant of the present invention can first secure a desired anti-theft function and realize a minimum drive of the vehicle body during the operation of the anti-theft system without interposing a password. An anti-theft device was proposed (Japanese Patent Application No. 2003-350884).

  The invention proposed by the applicant of the present application includes an anti-theft controller that outputs a signal related to anti-theft, and communication means for connecting the anti-theft controller and the vehicle body controller. And a means for outputting a system operation signal indicating that the anti-theft system is in operation when the anti-theft system is in operation. And a first determining means for determining whether or not a signal related to the anti-theft from the anti-theft controller is input, and a second for determining whether or not the system operating signal is input. When it is judged by the judging means and the first judging means that the input related to theft prevention is made Alternatively, it includes a flow rate limiting means for limiting the supply flow rate to the hydraulic actuator to a predetermined low flow rate when it is determined by the second determination means that the system operation signal is not input. .

  In the proposed invention, the predetermined low flow rate is a flow rate that can move the traveling body at a slow speed, or a flow rate that can move the work implement at a slow speed, that is, the flow rate of the traveling body in normal work. When traveling, the flow rate is set to a speed at which the vehicle body can be driven at a minimum speed, although the speed is much slower than when the work machine is activated. Thus, when a predetermined low flow rate is supplied to the hydraulic actuator, normal work cannot be performed.

  In this proposed invention, when the anti-theft controller is activated and the anti-theft system is working, the engine is kept in a state where the anti-theft controller can be driven and the vehicle body is communicated from the anti-theft controller via communication means. A signal related to theft prevention is output to the controller. The first determination means of the vehicle body controller determines that a signal related to anti-theft from the anti-theft controller is input, and the flow restriction means operates. Therefore, a predetermined low flow rate is supplied to the hydraulic actuator by driving the engine. In other words, in the state in which a signal related to theft prevention from such an antitheft controller is input, the vehicle body can be moved at a slow speed, but normal work is impossible. Even if it is stolen, normal work cannot be performed, so that the checking power against theft is secured. This greatly contributes to theft prevention. Further, even if an emergency situation occurs when the anti-theft system is operating and the vehicle body needs to be moved, the operator can perform the minimum drive of the vehicle body without intervening a password.

Similarly to the above, when the second anti-theft controller determines that the system operation signal is not input from the anti-theft controller due to a failure or theft of the anti-theft controller installed, The supply flow rate to the hydraulic actuator is limited to a predetermined low flow rate.
JP 2000-64363 A

  The anti-theft controller provided in the construction machine described above is generally an optional specification product, and can be attached to the corresponding construction machine according to the customer's selection. That is, there are construction machines to which the anti-theft controller is attached and construction machines to which the anti-theft controller is not attached even if they are the same type of construction machine.

  Here, regardless of whether or not the anti-theft controller is attached, in consideration of attaching the anti-theft controller, the signal relating to the anti-theft is input to the vehicle body controller by the first determination means as described above. A flow rate limiting means for limiting the supply flow rate of the hydraulic actuator to a predetermined low flow rate when it is determined that the system operation signal is not input by the second determination means. I want to keep it.

  However, when an attempt is made to include the above-described flow restricting means in a vehicle body controller provided in a construction machine to which no anti-theft controller is attached, there is no “output of the system operation signal from the anti-theft controller”. The second determination means determines that the system operation signal has not been input, and the flow restriction means restricts the supply flow rate to the hydraulic actuator to a predetermined low flow rate. It is inconvenient because it interferes with the machine work.

  The present invention has been made from the above-described actual situation, and its purpose is to ensure the function of the vehicle body controller that can be handled when the anti-theft controller is mounted, and good workability when the anti-theft controller is not mounted. It is to provide a construction machine that can be secured.

In order to achieve the above object, the present invention operates by a vehicle body including a traveling body and a working machine, an engine, a pump driven by the engine, and pressure oil discharged from the pump, and drives the vehicle body. A hydraulic actuator, and a vehicle body controller that controls a rotational speed of the engine and a supply flow rate to the hydraulic actuator, and the vehicle body controller restricts a supply flow rate to the hydraulic actuator to a predetermined low flow rate. look including means, in anti-theft controller mountable construction machine that outputs a signal related to the structure and anti-theft and anti-theft device with anti-theft system, to upper Symbol vehicle controller the operation of the flow limiting means effective Or a selection means capable of outputting a selection signal to be invalidated, the antitheft controller mounted, and the above Communication means for connecting to a body controller, and the anti-theft controller is configured to hold the engine in a state where a signal related to the anti-theft is output, and when the anti-theft system is operated. includes means for outputting a system actuation signal indicating that the anti-theft system is operating, the vehicle body controller, the flow restriction the flow limiting means from unrealized said selecting means means for disabling the operation of the A first determination means for determining whether or not a selection signal for enabling the operation is input and determining whether or not a signal related to the anti-theft from the anti-theft controller is input; and the system operation Second determination means for determining whether or not a signal is input, and the flow rate included in the vehicle body controller. The limiting means is when the first determining means determines that a signal related to theft prevention is being input in a state where the operation of the flow restricting means is determined to be effective by the vehicle body controller, or When the second determination means determines that the system operation signal is not inputted, the supply flow rate to the hydraulic actuator is limited to a predetermined low flow rate .

  In the present invention configured as described above, when a theft prevention controller is mounted, it is only necessary to select valid by the selection means and to output a selection signal for validating the operation of the flow restriction means to the vehicle body controller. As a result, the flow rate limiting means of the vehicle body controller operates appropriately according to the signal output from the anti-theft controller, and performs control to limit the supply flow rate to the hydraulic actuator to a predetermined low flow rate. As described above, this control makes it possible to move the vehicle body at a slow speed, but disables normal operations and secures a check force against theft. Further, even when an emergency situation occurs when the anti-theft system is operating and the vehicle body needs to be moved, the operator can perform the minimum drive of the vehicle body without interposing a password.

  If the anti-theft controller is not mounted, it is only necessary to select invalidity by the selection means and to output a selection signal for invalidating the operation of the flow restriction means to the vehicle body controller. As a result, the means for invalidating the operation of the flow rate limiting means included in the vehicle body controller is activated, and processing for invalidating the control for limiting the supply flow rate of the hydraulic actuator by the flow rate limiting means to a predetermined low flow rate is performed by this means. It is. Therefore, a situation where the flow is forcibly restricted to a predetermined low flow rate during the normal operation does not occur, and the normal operation can be performed without any trouble.

  That is, according to the present invention, the vehicle body controller includes flow restriction means for restricting the supply flow rate of the hydraulic actuator to a predetermined low flow rate, thereby ensuring the function of the vehicle body controller that can cope when the anti-theft controller is mounted. By selecting invalidity by the selection means, the operation of the flow rate restriction means becomes invalid, and good workability when the antitheft controller is not mounted can be ensured.

  Further, the present invention is characterized in that in the above invention, the flow rate limiting means includes means for limiting the engine speed to a predetermined low speed.

  Further, the present invention is characterized in that, in the above invention, the flow rate limiting means includes means for limiting the discharge flow rate of the pump to a predetermined low flow rate.

  The present invention can ensure the function of the vehicle body controller that can be accommodated when the anti-theft controller is mounted, and can also ensure good workability when the anti-theft controller is not mounted. A desired function can be ensured in any case where the anti-theft controller is not provided.

  The best mode for carrying out the construction machine according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a main part configuration diagram showing a first embodiment of the present invention, and FIG. 2 is a hydraulic circuit diagram showing a pump torque control device equipped in the first embodiment of the present invention.

  The first embodiment and the second and third embodiments described later are applied to, for example, a hydraulic excavator as a construction machine. This hydraulic excavator, that is, the first embodiment is provided with a vehicle body including a traveling machine, a working machine including a boom, an arm, and the like (not shown). As shown in FIGS. 1 and 2, the engine 1, a variable displacement hydraulic pump driven by the engine 1, that is, a main pump 2, and a travel motor (not shown) driven by pressure oil discharged from the main pump 2. And hydraulic actuators such as boom cylinders and arm cylinders, and directional control valves (not shown) for controlling these hydraulic actuators. Moreover, it has the vehicle body controller 13 which controls the rotation speed of the engine 1 and the supply flow volume to the above-mentioned hydraulic actuator.

  The pump torque control device provided in the first embodiment will be described first with reference to FIG. 2, and then the basic characteristics possessed by the first embodiment will be described with reference to FIGS. The features of the first embodiment of the invention will be described.

[Pump torque control device]
One embodiment of the present invention includes a pilot pump 3 driven by the engine 1 and a tank 4, as shown in FIG. The operation device 5 that operates the hydraulic actuator (not shown) described above, a tilt control actuator 6 that controls the tilt angle of the main pump 2, and torque adjusting means that adjusts the maximum pump torque of the main pump 2 are provided. Yes. The tilt control actuator 6 includes a pressure receiving chamber 6a to which the control pressure is guided, a pressure receiving chamber 6b to which the pilot pressure is guided, and a spool 6c that controls the tilt angle.

  The torque adjusting means described above corresponds to the torque control valve 7 that controls the tilt control actuator 6 so as to keep the maximum pump torque constant regardless of the change in the discharge pressure of the main pump 2 and the operation amount of the operating device 5. And a position control valve 8 for adjusting the maximum pump torque. The torque control valve 7 includes a spool 7a, a spring 7b for biasing the spool 7a, a pressure receiving chamber 7c to which a control pressure related to horsepower control is guided, and a pressure receiving chamber 7d to which a pump pressure is guided. The position control valve 8 includes a spool 8b and a spring 8a that biases the spool 8b. A pilot pressure accompanying the operation of the operating device 5 is applied to the control chamber of the position control valve 8 through the pipe line 32 so as to counteract the force of the spring 8a.

  In addition, a tilt sensor 9 that detects the tilt angle of the main pump 2, a discharge pressure sensor 10 that detects the discharge pressure of the main pump 2, and a pilot that detects the pilot pressure that is output as the operating device 5 is operated. A pressure sensor 11 and a rotational speed indicator 12 for instructing a target rotational speed of the engine 1 are provided.

  In addition, the above-described sensors 9 to 11 and the rotation speed indicator 12 are input, and a memory function and an arithmetic function including a logical determination are provided, and a control signal corresponding to the arithmetic result is output. A vehicle body controller 13 and an engine controller 15 that outputs a signal for operating the fuel injection pump 14 that controls the engine speed in accordance with the engine speed signal output from the vehicle body controller 13 are provided.

  In addition, an electromagnetic valve 16 is provided that operates in response to a control signal output from the vehicle body controller 13 and operates the spool 7a of the torque control valve 7 against the force of the spring 7b.

  Of the above-described components, the tilt control actuator 6, the torque control valve 7, the position valve 8, and the electromagnetic valve 16 constitute a regulator 2A that controls the tilt angle of the main pump 2. The regulator 2A, the vehicle body controller 13, the operation device 5, the sensors 9 to 11 and the like constitute a pump torque control device that controls the torque of the main pump 2.

[Basic characteristics possessed by the first embodiment]
3 to 5 are diagrams illustrating basic characteristics possessed by the first embodiment, and FIG. 3 is a diagram illustrating pump discharge pressure-push-off volume characteristics (corresponding to PQ characteristics) and pump discharge pressure-pump torque characteristics. FIG. 4 is a diagram showing PQ line movement characteristics, and FIG. 5 is a diagram showing engine target speed-torque characteristics.

  As a basic characteristic possessed by the first embodiment, the relationship between the pump discharge pressure P and the displacement volume q shown in FIG. 3A, that is, the discharge flow rate Q corresponding to the pump discharge pressure P and the displacement volume q is shown. It has the characteristic shown in the PQ diagram 20 which is the relationship. This PQ diagram 20 corresponds to the constant pump torque diagram 21. Further, as shown in FIG. 3 (b), the pump torque has a characteristic shown by a pump torque diagram 22 by PQ control which is a relationship of pump discharge pressure P-pump torque.

As described above, assuming that the discharge pressure of the main pump 2 is P, the displacement volume is q, the pump torque is Tp, and the mechanical efficiency is ηm,
Tp = (P × q) / (628 × ηm)
It is known that

  Further, as a basic characteristic of the first embodiment, as shown in FIG. 4, it has a PQ line movement characteristic. In FIG. 4, 23 is a PQ diagram corresponding to the maximum pump torque based on the target engine speed, and 24 is a PQ diagram corresponding to the pump torque by low torque control lower than the maximum pump torque described above. By performing the torque control process, it is possible to move between the PQ diagram 23 corresponding to the original maximum pump torque and the PQ diagram 24 corresponding to the low pump torque corresponding to the predetermined low rotational speed n1. Yes.

  Further, as basic characteristics of the first embodiment, the characteristics shown in the engine maximum torque diagram 25 shown by the relationship between the target rotational speed and the torque of the engine 1 shown in FIG. 5 and the engine maximum torque diagram 25 are not exceeded. The maximum pump torque curve that can be suppressed as shown in FIG. The maximum pump torque becomes a small value Tp1 on the maximum pump torque diagram 26 when the target rotational speed of the engine 1 is a predetermined low rotational speed n1, and becomes maximum when the target rotational speed of the engine 1 reaches, for example, the rated rotational speed n2. The maximum value Tp2 on the pump torque diagram 26 is obtained. The PQ diagram when the maximum value Tp2 is reached on the maximum pump torque diagram 26 shown in FIG. 5 is, for example, the PQ diagram 23 of FIG. 4, and the small value Tp1 on the maximum pump torque diagram 26 shown in FIG. The PQ diagram at this time is, for example, the PQ diagram 24 of FIG.

[Main Configuration of First Embodiment]
As shown in FIG. 1, the first embodiment having the above-described components and basic characteristics is connected to the starter 1a of the engine 1 via a signal line 41 and outputs a signal related to theft prevention. The anti-theft device includes a controller 40 and a communication line 42 that connects the anti-theft controller 40, the vehicle body controller 13, and the engine controller 15.

  The anti-theft controller 40 includes, for example, a first processing unit 40a and a second processing unit 40b. When a processing operation is performed by the first processing unit 40a, for example, a first anti-theft system which is the same anti-theft system as before is activated. That is, a signal for preventing the starter 1a from being driven is output from the antitheft controller 40 to the starter 1a of the engine 1 as a signal related to theft prevention via the signal line 41, and the antitheft controller 40 is connected to the communication line. A vehicle body operation restriction signal for restricting the driving of the vehicle body is output to the vehicle body controller 13 via 42 as a signal related to theft prevention. By canceling the above-described processing operation of the first processing unit 40a, the drive inhibition of the starter 1a is cancelled, and the restriction on driving of the vehicle body by the vehicle body controller 13 is cancelled.

  Further, when a processing operation is performed by the second processing unit 40b, a second anti-theft system different from the above-described first anti-theft system is activated. When the second antitheft system is activated, the antitheft controller 40 outputs a vehicle body operation restriction signal as a signal related to antitheft. Further, for example, a system operation signal indicating that the second antitheft system is operating is output from the antitheft controller 40. In the second anti-theft system, the anti-theft controller 40 does not output a signal for preventing the starter 1a of the engine 1 from being driven. Therefore, the drive of the engine 1 is kept possible.

  The vehicle body controller 13 receives the signal related to anti-theft from the anti-theft controller 40, that is, the first determining means for determining whether or not the above-described vehicle body operation restriction signal is input, and the above-described operation is performed when the second anti-theft system is operated. Second determination means for determining whether or not a system operation signal has been input, and when it is determined by the first determination means that a vehicle body operation restriction signal has been input, or the second determination means When it is determined that the input is not made, the flow rate limiting means for limiting the supply flow rate to a hydraulic actuator (not shown) to a predetermined low flow rate is included. The flow rate limiting means includes means for limiting the engine speed to a predetermined low speed n1, for example.

  The predetermined low flow rate limited by the flow rate limiting means included in the vehicle body controller 13 described above is a flow rate that can move the traveling body included in the vehicle body at a slow speed, or a slow speed of the work machine included in the vehicle body. It is a flow rate that can be moved by. In other words, the predetermined low flow rate is set to a flow rate at a speed that allows the minimum driving of the vehicle body, although it is a much slower speed than the time when the working machine is operated during the traveling of the traveling body in normal work. . In the first embodiment, by limiting the rotational speed of the engine 1 to the predetermined low rotational speed n1 shown in FIG. 5 described above, a flow rate corresponding to the predetermined low flow rate is discharged from the main pump 2. A predetermined low flow rate is supplied to a hydraulic actuator (not shown).

  In particular, the first embodiment includes means for invalidating the operation of the flow restriction means described above by the vehicle body controller 13 and, as shown in FIG. A selection means 50 capable of outputting a selection signal is provided. That is, the selection means 50 includes a valid switch 50a and an invalid switch 50b. When the valid switch 50a is turned on, a valid selection signal is output to the vehicle body controller 13, and when the invalid switch 50b is turned on, the invalid selection signal is sent to the vehicle body controller. 13 is output.

[Operation of First Embodiment]
Hereinafter, the operation of the first embodiment configured as described above will be described.

[At the time of processing operation of the first processing unit 40a]
For example, in the first embodiment, that is, when the hydraulic excavator is stored in a predetermined warehouse, it is not necessary to perform work using a work machine, and it is not necessary to drive the traveling body, the anti-theft Processing is performed in the first processing unit 40a of the controller 40, and the first anti-theft system is activated.

  At this time, as a signal related to theft prevention from the antitheft controller 40 via the signal line 41, a signal for preventing the starter 1a from being driven is output to the starter 1a of the engine 1 as described above, and the theft prevention is performed. A vehicle body operation restriction signal is output from the controller 40 via the communication line 42 as a signal related to theft prevention.

  This prevents the starter 1a from being driven. In addition, the vehicle body controller 13 that has received the vehicle body operation restriction signal from the antitheft controller 40 performs a process of stopping the output of the engine speed signal to the engine controller 15. Therefore, the fuel injection pump 14 shown in FIG. 2 is stopped and held. As a result, the engine 1 is kept inoperable.

  The vehicle body controller 13 that has received the above-described vehicle body operation restriction signal outputs a control signal for holding the electromagnetic valve 16 in FIG. 2 to the upper position as shown in FIG. Thereby, the pilot pressure of the pilot pump 3 is applied to the pressure receiving chamber 7c of the torque control valve 7 through the electromagnetic valve 16, and the spool 7a of the torque control valve 7 moves to the left in FIG. The pilot pressure of the pilot pump 3 is applied to both the pressure receiving chambers 6 a and 6 b of the control actuator 6. At this time, due to the pressure receiving area difference between both end surfaces of the spool 6c of the tilt control actuator 6, the spool 6c moves to the right in FIG. 2, and the tilt angle of the main pump 2 changes in the direction of the arrow 30. Minimum tilt angle. Therefore, the main pump 2 can hold a discharge at a minimum flow rate corresponding to the predetermined low flow rate described above. However, since the engine 1 is held incapable of driving as described above, the main pump 2 driven by the engine 1 is not driven and pressure oil is supplied from the main pump 2 to a hydraulic actuator (not shown). There is no.

  In this way, the traveling body included in the vehicle body of the first embodiment housed in the warehouse is kept inoperable, and the work machine included in the vehicle body is kept inoperable, and a check force against theft is secured. .

  When the first antitheft system described above is released and the first embodiment is run or the work machine is operated to perform a desired normal operation or the like, the first antitheft controller 40 is used. Processing for canceling the processing operation of the processing unit 40a is performed.

  As a result of this release processing, the output of the signal for preventing the starter 1a from being driven from the antitheft controller 40 is stopped, and the antitheft controller 40 sends the vehicle body controller 13 to the vehicle body controller 13 via the communication line 42 instead of the above-described vehicle body operation restriction signal. The vehicle body operation permission signal is output. The vehicle body controller 13 receiving this vehicle body operation permission signal outputs an engine speed signal corresponding to a predetermined low speed n1 to the engine controller 15 via the communication line 42 shown in FIG. As a result, the engine controller 15 holds the engine 1 in a state where the engine 1 can be started at a predetermined low speed n1. When the starter 1a is driven here, the fuel injection pump 14 shown in FIG. 2 is operated from the engine controller 15, and the engine 1 can be started at a predetermined low speed n1. Subsequently, the vehicle body controller 13 outputs an engine speed signal corresponding to the engine target speed indicated by the speed indicator 12 shown in FIG. 2 to the engine controller 15 via the communication line 42 shown in FIG. As a result, a control signal corresponding to the fuel injection pump 14 is output from the engine controller 15, and the engine 1 is driven at the rotational speed indicated by the rotational speed indicator 12.

  Further, the vehicle body controller 13 that has received the vehicle body operation permission signal outputs a control signal for switching the electromagnetic valve 16 in FIG. 2 to the lower position in FIG. As a result, the pressure receiving chamber 7 c of the torque control valve 7 communicates with the tank 4 via the electromagnetic valve 16. Therefore, the spool 7a of the torque control valve 7 is held at a position where the pressure of the main pump 2 applied to the pressure receiving chamber 7d, that is, the force due to the pump discharge pressure, and the force of the spring 7b are balanced. The tilt angle of 2 is controlled to be larger than the minimum tilt angle. When the operating device 5 is operated, a directional control valve (not shown) is switched according to the amount of operation, and a flow rate required for traveling of the traveling body included in the vehicle body or operation of the work machine is supplied from the main pump 2 to a hydraulic pressure (not shown). Supplied to the actuator. That is, it is possible to perform a desired normal operation or the like.

[At the time of processing operation of the second processing unit 40b]
6 and 7 are flowcharts showing processing procedures in the vehicle body controller 13. Hereinafter, processing when the second anti-theft system is operated by the processing operation in the second processing unit 40b of the anti-theft controller 40 will be described based on the flowcharts of FIGS.

  For example, when the first embodiment is stopped for several hours at a work site in a town or the like, the effective switch 50a is turned on by the selection means 50 when the antitheft of the first embodiment is performed. The second anti-theft system is activated by a processing operation in the second processing unit 40b of the anti-theft controller 40.

  When a processing operation is performed in the second processing unit 40b of the antitheft controller 40, a drive inhibition signal from the antitheft controller 40 to the starter 1a is not output. Therefore, the engine 1 is held in a drivable state. In addition, a vehicle body operation restriction signal is output from the antitheft controller 40 to the vehicle body controller 13 via the communication line 42 as a signal related to theft prevention. A system operation signal indicating that the second anti-theft system has been operated, for example, every predetermined period is output together with the vehicle body operation restriction signal. Furthermore, an effective selection signal is output to the vehicle body controller 13 by operating the effective switch 50 a of the selection means 50.

  As shown in the flowchart of FIG. 6, the vehicle body controller 13 first determines whether an effective selection signal is input from the selection means 50 (step S1 of FIG. 6). Since this valid selection signal is input now, this determination is yes. Next, the first determination means provided in the vehicle body controller 13 determines whether or not a vehicle body operation permission signal has been input (step S2 in FIG. 6). This determination is NO because the vehicle body operation restriction signal is currently input and the vehicle body operation permission signal is not input. Next, the first determination means provided in the vehicle body controller 13 determines whether or not a vehicle body operation restriction signal has been input (step S3 in FIG. 6). Now, since the vehicle body operation restriction signal is input, this determination is yes. Accordingly, at this time, a predetermined low speed n1 is set as the target speed of the engine 1 (step S4 in FIG. 6). As described above, the predetermined low rotational speed n1 is the rotational speed of the engine 1 that can supply the hydraulic actuator with a flow rate capable of performing the minimum driving of the vehicle body.

  Next, an engine speed signal corresponding to the set predetermined low speed n1 is output to the engine controller 15 via the communication line 42 (step S5 in FIG. 6). As a result, the engine 1 is held in a state where it can be driven at a predetermined low rotational speed n1.

  If the first embodiment, that is, the hydraulic excavator is stolen during the operation of the second antitheft system, the operation shown in FIG. 2 is performed with the starter 1a driven and the engine 1 activated. Even if the directional control valve (not shown) is switched by operating the device 5, the flow rate discharged from the main pump 2 becomes a predetermined low flow rate corresponding to the above-described engine speed, that is, the predetermined low speed n1. Further, the pump torque at this time becomes a small value Tp1 shown in FIG. Therefore, although the traveling body included in the vehicle body can travel at a slow speed and the working machine can operate at a slow speed, normal work such as traveling at normal speed or excavation work cannot be performed.

  During the operation of the second antitheft system as described above, a system operation signal is output from the antitheft controller 40, for example, at predetermined intervals. As shown in the flowchart of FIG. 7, the vehicle body controller 13 first determines whether or not an effective selection signal is input from the selection means 50 (step S11 of FIG. 7). Since this valid selection signal is input now, this determination is yes. Next, the second determination means provided in the vehicle body controller 13 determines whether or not this system operation signal is always input during the operation of the second antitheft system (step S12 in FIG. 7).

  Here, when a failure occurs in the anti-theft controller 40 or when the communication line 42 connecting the anti-theft controller 40 and the vehicle body controller 13 is disconnected due to theft of the anti-theft controller 40 or the like, No system activation signal is input and the above determination is no. At this time as well, a predetermined low speed n1 is set as the target speed of the engine 1 (step S13 in FIG. 7) as in step S4 in FIG. 6 described above. Next, an engine speed signal corresponding to the set predetermined low speed n1 is output to the engine controller 15 via the communication line 42 (step S14 in FIG. 7). Therefore, as described above, the engine 1 is maintained in a state where it can be driven at a predetermined low rotational speed n1.

  When the second antitheft system described above is released and desired normal work or the like is to be resumed, a process of turning off the effective switch 50a of the selection means 50 is performed.

  With this processing, the judgment in step S1 in FIG. 6 and the judgment in step S11 in FIG. 7 are no, and the vehicle body controller 15 determines the engine speed of the engine 1 by the engine speed indicator 12 shown in FIG. The engine speed is set (step S6 in FIG. 6) (step S15 in FIG. 7), and the corresponding engine speed signal is output to the engine controller 15 shown in FIG. As a result, a control signal is output from the engine controller 15 to the fuel injection pump 14, and the engine 1 is driven at the rotational speed designated by the target rotational speed indicator 12.

  Further, the vehicle body controller 13 that has received the vehicle body operation permission signal outputs a control signal for switching the electromagnetic valve 16 in FIG. 2 to the lower position in FIG. As a result, the pressure receiving chamber 7 c of the torque control valve 7 communicates with the tank 4 via the electromagnetic valve 16. Accordingly, as described above, the spool 7a of the torque control valve 7 is held at a position where the pressure of the main pump 2 applied to the pressure receiving chamber 7d, that is, the force of the pump discharge pressure and the force of the spring 7b are balanced. Accordingly, the tilt angle of the main pump 2 is controlled to increase. When the operating device 5 is operated, a directional control valve (not shown) is switched according to the amount of operation, and a flow rate required for traveling of the traveling body included in the vehicle body or operation of the work machine is supplied from the main pump 2 to a hydraulic pressure (not shown). Supplied to the actuator. That is, it is possible to perform a desired normal operation or the like.

  According to the first embodiment configured as described above, for example, in a situation where the first embodiment is left at the work site and may be stolen, the second anti-theft system may be operated. While the second antitheft system is in operation, the vehicle body can be moved at a slow speed, but normal operations are disabled. Therefore, even if it is stolen, normal work cannot be performed, so the function as a hydraulic excavator is lost, and a check force against theft is secured. This greatly contributes to theft prevention.

  Further, when the second anti-theft system is operating and an emergency situation occurs and it is necessary to move the vehicle body, the starter 1a is driven and the operation device 5 is operated to interpose the password. Instead, a predetermined low flow rate corresponding to the predetermined low rotation speed n1 can be supplied from the main pump 2 to a hydraulic actuator (not shown). As a result, the minimum drive can be realized, and an excellent function can be secured, which is practical.

  During the operation of the second anti-theft system, a system operation signal is output from the anti-theft controller 40, for example, at predetermined intervals, and the second determination means of the vehicle body controller 13 receives the system operation signal as described above. If it is determined that the target rotation speed is not input, the target rotation speed of the engine 1 is set to a predetermined low rotation speed n1, so that the anti-theft controller 40 is broken, the communication line 42 is disconnected, etc. Even when the system operation signal is not input to the vehicle body controller 13 as described above, a predetermined low flow rate corresponding to the predetermined low rotation speed n1 can be supplied to the hydraulic actuator (not shown) as described above. Therefore, even when the anti-theft controller 40 is malfunctioning during the operation of the second anti-theft system, the vehicle body can be moved at a slow speed as necessary.

[Configuration of Second Embodiment]
The second embodiment of the present invention is also equipped with an antitheft device. Particularly in the second embodiment, when it is determined by the first determination means provided in the vehicle body controller 13 that the vehicle body operation restriction signal is input, the supply flow rate to the hydraulic actuator (not shown) is limited to a predetermined low flow rate. The flow rate limiting means includes means for limiting the discharge flow rate of the main pump 2 to a predetermined low flow rate. Other configurations are the same as those of the first embodiment described above.

[Operation of Second Embodiment]
Also in the second embodiment, when a processing operation is performed in the first processing unit 40a of the anti-theft controller 40, the same processing operation as in the first embodiment is performed. The processing operation in the second processing unit 40a is different from that in the first embodiment.

  FIG. 8 is a flowchart showing a processing procedure in the vehicle body controller 13 provided in the second embodiment. Hereinafter, the processing in the case where the effective switch 50a is turned on and the second anti-theft system is activated by the second processing unit 40b of the anti-theft controller 40 and the second anti-theft system operates will be described with reference to the flowchart shown in FIG. This will be described based on the flowchart shown in FIG.

  When the second processing unit 40b of the anti-theft controller 40 is operated, the second anti-theft system is activated. As described in the first embodiment, at this time, the anti-theft controller 40 sends a drive inhibition signal to the starter 1a. Is not output, and a vehicle body operation restriction signal is output to the vehicle body controller 13 as a signal related to theft prevention. In addition, a system operation signal indicating that the second antitheft system has been operated, for example, every predetermined period is output. Is done.

  The vehicle body controller 13 first determines whether an effective selection signal is input from the selection means 50 (step S21 in FIG. 8). Since this valid selection signal is input now, this determination is yes. Next, the first determination means provided in the vehicle body controller 13 determines whether or not a vehicle body operation permission signal has been input (step S22 in FIG. 8). This determination is NO because the vehicle body operation restriction signal is currently input and the vehicle body operation permission signal is not input. Next, the first determination means provided in the vehicle body controller 13 determines whether or not a vehicle body operation restriction signal has been input (step S23 in FIG. 8). Now, since the vehicle body operation restriction signal is input, this determination is yes. Therefore, at this time, the pump torque is set to a minimum value, that is, a small value Tp1 at the predetermined low rotational speed n1 shown in FIG. 5 (step S24 in FIG. 8). This small pump torque value Tp1 is a pump torque value at which normal operation is impossible, although the minimum drive of the vehicle body can be performed.

  Next, a control signal corresponding to the set pump torque value Tp1 is output to the controller of the electromagnetic valve 16 shown in FIG. 2, and this electromagnetic valve 16 is operated to the upper position shown in FIG. Procedure S25).

  As a result, the pilot pressure of the pilot pump 3 is guided to the pressure receiving chamber 7c of the torque control valve 7 through the electromagnetic valve 16, and the spool 7a of the torque control valve 7 slides in the left direction in FIG. Accordingly, the pilot pressure of the pilot pump 3 is supplied to both the pressure receiving chambers 6 a and 6 b of the tilt control actuator 6. At this time, the spool 6c moves to the right in FIG. 2 due to the pressure receiving area difference between both end faces of the spool 6c, and the tilt angle of the main pump 2 is the minimum tilt as shown by the arrow 30 in FIG. It becomes a corner. That is, although the minimum drive of the vehicle body can be performed from the main pump 2, a predetermined low flow rate at which normal work cannot be performed can be supplied to the hydraulic actuator.

  If the hydraulic excavator is stolen during the operation of the second antitheft system, the starter 1a is driven and the engine 1 is started to operate the operating device 5 shown in FIG. Even if the directional control valve (not shown) is switched, the flow rate discharged from the main pump 2 becomes a predetermined low flow rate corresponding to the small pump torque value Tp1 shown in FIG. 5 equivalent to that in the first embodiment described above. Therefore, as in the first embodiment, the traveling body included in the main body can run at a slow speed and the working machine can operate at a slow speed, but cannot perform normal work or the like.

  Also in the second embodiment, as in the first embodiment, a system operation signal is output from the anti-theft controller 40 during operation of the second anti-theft system, as shown in the flowchart of FIG. The vehicle body controller 13 first determines whether or not an effective selection signal is input from the selection means 50 (step S11 in FIG. 7). Since this valid selection signal is input now, this determination is yes. Next, when the second determination means provided in the vehicle body controller 13 determines whether or not the system operation signal is input (step S12 in FIG. 7), and when it is determined that the system operation signal is not input, A predetermined low rotational speed n1 is set as the target rotational speed of the engine 1 (step S13 in FIG. 7), and then an engine rotational speed signal corresponding to the predetermined low rotational speed n1 is set via the communication line 42. It is output to the engine controller 15 (step S14 in FIG. 7). Therefore, at this time, the engine 1 is held in a state where it can be driven at a predetermined low rotational speed n1.

  Then, when the valid switch 50a of the selection means 50 is turned off to release the second anti-theft system, the determination in step S11 in FIG. 7 is no and the target speed of the engine 1 is instructed by the speed indicator 12. (Step S15 in FIG. 7), the determination in step S21 in FIG. 8 is no, and the pump torque is calculated according to the target rotational speed instructed by the rotational speed indicator 12. Is set (step S26 in FIG. 8), and a control signal corresponding to the calculated torque is output to the controller of the electromagnetic valve 16 shown in FIG. As a result, the electromagnetic valve 16 is switched to the lower position, the pressure receiving chamber 7c of the torque control valve 7 tends to communicate with the tank 4, and the spool 6c of the tilt control actuator 6 slides to the left in FIG. Thus, the tilt angle of the main pump 2 is controlled to be larger than the minimum tilt angle. Therefore, it becomes possible to perform a desired normal operation or the like.

  In the second embodiment configured as described above, the vehicle body can be moved at a slow speed during the operation of the second antitheft system, but normal operation is impossible, and a password is interposed when necessary. Therefore, the minimum driving of the vehicle body is possible, and the same effect as in the first embodiment described above can be obtained.

[Configuration of Third Embodiment]
The third embodiment of the present invention is also equipped with an anti-theft device. Particularly in the third embodiment, when it is determined by the first determination means provided in the vehicle body controller 13 that the vehicle body operation restriction signal is input, the supply flow rate to the hydraulic actuator (not shown) is limited to a predetermined low flow rate. Means for restricting the engine speed provided in the first embodiment to a predetermined low speed n1 and means for restricting the discharge flow rate of the main pump 2 provided in the second embodiment to a predetermined low flow rate. Including. Other configurations are the same as those of the first embodiment described above.

[Operation of Third Embodiment]
The processing operation in the third embodiment is a combination of the processing operations in the first and second embodiments described above. Therefore, also in the third embodiment, when the first processing unit 40a of the anti-theft controller 40 is operated, the same processing operation as in the first embodiment is performed.

  FIG. 9 is a flowchart showing a processing procedure in the vehicle body controller 13 provided in the third embodiment. FIG. 9 is a flowchart illustrating the process when the second antitheft system is activated by the operation of the second processing unit 40b of the antitheft controller 40 when the valid switch 50a is turned on by the selection unit 50. This will be described based on the flowchart shown in FIG.

  The second anti-theft system operates when the second processing unit 40b of the anti-theft controller 40 is operated. At this time, the drive prevention signal is not output from the anti-theft controller 40 to the starter 1a, and the anti-theft is related. A vehicle body operation restriction signal is output to the vehicle body controller 13 as a signal to be transmitted, and in addition, a system operation signal indicating that the second antitheft system has been operated, for example, every predetermined period is output.

  The vehicle body controller 13 first determines whether an effective selection signal is input from the selection means 50 (step S31 in FIG. 9). Since this valid selection signal is input now, this determination is yes. Next, the first determination means provided in the vehicle body controller 13 determines whether or not a vehicle body operation permission signal has been input (step S32 in FIG. 9). This determination is NO because the vehicle body operation restriction signal is currently input and the vehicle body operation permission signal is not input. Next, the first determination means provided in the vehicle body controller 13 determines whether or not a vehicle body operation restriction signal has been input (step S33 in FIG. 9). Now, since the vehicle body operation restriction signal is input, this determination is yes. Therefore, at this time, the target rotational speed of the engine 1 is set to a predetermined low rotational speed n1 (step S34 in FIG. 9), and the pump torque is set to a small value Tp1 (step S35 in FIG. 9). .

  Next, an engine speed signal corresponding to the set predetermined low speed n1 is output to the engine controller 15 (step S36 in FIG. 9), and a control signal corresponding to the pump torque value Tp1 is output from the solenoid valve 16. The data is output to the control unit (step S37 in FIG. 9).

  As described above by these controls, the engine 1 is held in a state capable of being driven at a predetermined low rotational speed n1, and the main pump 2 is held so as to be able to discharge at a predetermined low flow rate. That is, when a directional control valve (not shown) is switched in accordance with the operation of the operating device 5, a predetermined low flow rate can be supplied to a hydraulic actuator (not shown). In the third embodiment, according to the flowchart of FIG. 7, the determination as to whether or not the system operation signal is input and the corresponding processing are performed in the same manner as in the first and second embodiments described above. The

  Further, when the valid switch 50a of the selection means 50 is turned off to release the second anti-theft system, the judgment in step S11 in FIG. 7 and the judgment in step S31 in FIG. The engine target speed indicated by the speed indicator 12 is set (step S15 in FIG. 7) (step S38 in FIG. 9), and the pump torque is set according to the target speed indicated by the speed indicator 12. The process for obtaining the calculated torque is performed (step S39 in FIG. 9). An engine speed signal and a control signal corresponding to these target speed and calculated torque are output to the engine controller 15 and the solenoid valve 16 (steps S36 and S37 in FIG. 9).

  As a result, the engine 1 can be driven at the rotational speed designated by the rotational speed indicator 12, and the tilt angle of the main pump 2 is controlled to be large. Therefore, it becomes possible to perform a desired normal operation or the like.

  The third embodiment configured as described above cannot perform normal work during the operation of the second anti-theft system, and can perform minimum driving of the vehicle body without interposing a password when necessary. 1, the same effect as in the second embodiment can be obtained.

  The first to third embodiments described above are hydraulic excavators equipped with an antitheft device. However, in the first to third embodiments described above, the main portion of the antitheft device may be omitted. In other words, a configuration in which the anti-theft controller 40 portion surrounded by a broken line is excluded from the configuration shown in FIG.

  For example, when the anti-theft controller 40 is removed from the configuration of the first embodiment, the invalid switch 50b of the selection unit 50 is turned on when the hydraulic excavator is driven. As a result, an invalid selection signal is output from the selection means 50 to the vehicle body controller 13, and the means for invalidating the operation of the flow rate restriction means of the vehicle body controller 13 works, that is, the determination in step S1 in FIG. 6 and the step S11 in FIG. Therefore, the engine 1 can be driven at the rotational speed designated by the rotational speed indicator 12, and a desired normal operation or the like can be performed.

  When the effective switch 50a of the selection means 50 is turned on by mistake except for the anti-theft controller 40 as described above, for example, the process of steps S11 → S12 → S13 → S14 in FIG. 7 is performed. Thus, the engine 1 can be driven only at a predetermined low rotational speed n1.

  As described above, in the configuration in which the anti-theft controller 40 is removed from the configuration of the first embodiment, the vehicle body controller 13 has a flow rate limiting function that can be handled when the anti-theft controller 40 is mounted, but is invalidated by the selection means 50. By turning on the switch 50b, normal work or the like can be performed without any trouble. Similarly to the configurations of the second embodiment and the third embodiment described above excluding the anti-theft controller 40, normal operations and the like can be performed without any trouble.

  That is, in each of the above-described embodiments, the function of the vehicle body controller 13 that can be handled when the anti-theft controller 40 is mounted can be secured, and the invalidation switch 50b is turned on by the selection means 50, whereby the anti-theft controller 40 is turned on. Good workability can be secured when the is not mounted. Therefore, in the case where the anti-theft controller 40 is provided or the anti-theft controller 40 is not provided, a desired function can be ensured.

It is a principal part block diagram which shows 1st Embodiment of the construction machine which concerns on this invention. 1 is a hydraulic circuit diagram showing a pump torque control device equipped in a first embodiment of the present invention. It is a figure which shows the pump discharge pressure-push-off volume characteristic (corresponding to PQ characteristic) and the pump discharge pressure-pump torque characteristic among the basic characteristics possessed by the first embodiment of the present invention. It is a figure which shows the PQ line movement characteristic among the basic characteristics which 1st Embodiment of this invention has. It is a figure which shows the engine target rotation speed-torque characteristic among the basic characteristics which 1st Embodiment of this invention has. It is a flowchart which shows the process sequence in the vehicle body controller with which 1st Embodiment of this invention is equipped. It is a flowchart which shows the process sequence in the vehicle body controller with which 1st Embodiment of this invention is equipped. It is a flowchart which shows the process sequence in the vehicle body controller with which 2nd Embodiment of this invention is equipped. It is a flowchart which shows the process sequence in the vehicle body controller with which 3rd Embodiment of this invention is equipped.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 1a Starter 2 Main pump 2A Regulator 3 Pilot pump 4 Tank 5 Operating device 6 Tilt control actuator 6a Pressure receiving chamber 6b Pressure receiving chamber 6c Spool 7 Torque control valve 7a Spool 7b Spring 7c Pressure receiving chamber 7d Pressure receiving chamber 12 Speed indicator 13 Body controller 15 Engine controller 16 Solenoid valve 16a Spring 23 PQ diagram 24 PQ diagram 25 Engine maximum torque diagram 26 Maximum pump torque diagram 40 Anti-theft controller 40a First processing unit 40b Second processing unit 41 Signal line 42 Communication line (Communication means)
TP1 Small value TP2 Maximum value n1 Predetermined low speed n2 Rated speed 50 Selection means 50a Effective selection switch 50b Invalid selection switch

Claims (3)

A vehicle body including a traveling body and a work machine, an engine, a pump driven by the engine, a hydraulic actuator that operates by pressure oil discharged from the pump and drives the vehicle body, a rotational speed of the engine, and the above and a vehicle controller for controlling the supply flow rate to the hydraulic actuator, the vehicle body controller, see contains a flow restriction means for restricting the supply flow rate to the hydraulic actuator to a predetermined low flow rate, anti-theft with anti-theft system In construction machines that can be equipped with an anti-theft controller that configures the device and outputs signals related to anti-theft ,
Selection means capable of outputting a selection signal for enabling or disabling the operation of the flow rate restriction means to the vehicle body controller;
Communication means for connecting the mounted anti-theft controller and the vehicle body controller,
The anti-theft controller is configured to hold the engine in a state where a signal related to anti-theft is output, and that the anti-theft system is in operation when the anti-theft system is in operation. Means for outputting a system activation signal indicating:
The body controller is adapted to determine whether the selection signal for enabling operation of the flow restriction means for disabling the unrealized said selection means the operation of the flow restriction means is inputted, said anti-theft First determination means for determining whether a signal related to theft prevention from the controller is input;
Second determining means for determining whether or not the system operation signal is input,
The flow rate restricting means included in the vehicle body controller is inputted with a signal related to theft prevention by the first judging means in a state where the operation of the flow rate restricting means is judged to be effective by the vehicle body controller. When it is determined, or when it is determined by the second determination means that the system operation signal is not input, the supply flow rate to the hydraulic actuator is limited to a predetermined low flow rate. A featured construction machine. In the invention of claim 1,
The construction machine , wherein the flow rate limiting means includes means for limiting the engine speed to a predetermined low speed . In the invention according to claim 1 or 2 ,
The construction machine, wherein the flow rate limiting means includes means for limiting a discharge flow rate of the pump to a predetermined low flow rate .

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